Hands on guide to imaging 1 ed 2004

DAVID HOWLETT & BRIAN AYERS

The hands-on guideto imaging

The hands-on guide to imaging

Dedications

To my parents, Kenneth and Margaret and also my children, Thomas and Ella.David Howlett

To Janet and Jenny.Brian Ayers

The hands-on guide to imaging

DAVID C. HOWLETTMRCP, FRCR

BRIAN AYERSMD, FRCR

© 2004 D.C. Howlett and A.B. AyersPublished by Blackwell Publishing LtdBlackwell Publishing, Inc, 350 Main Street, Malden, Massachusetts 02148-5020,USABlackwell Publishing Ltd, 9600 Garsington Road, Oxford OX4 2DQ , UKBlackwell Publishing Asia Pty Ltd, 550 Swanston Street, Carlton, Victoria 3053, Australia

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First published 2004

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The hands-on guide to imaging / David C. Howlett, Brian Ayers.p. ; cm.

Includes bibliographical references and index.ISBN 1-4051-1551-3

1. Diagnostic imaging — Handbooks, manuals, etc.[DNLM: 1. Diagnostic Imaging — methods — Handbooks. WN 39 H864h

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List of contributors, viForeword, viiPreface, ixAcknowledgements, xAbbreviations, xi

1 Making the best use of the radiology department, 1

2 Imaging techniques, 9

3 Respiratory system, 16

4 Cardiovascular system, 40

5 The upper gastrointestinal tract, 57

6 The lower gastrointestinal tract,81

7 Hepatobiliary and pancreaticimaging, 104

8 The breast, 129

9 Musculoskeletal system, 137

10 The neck, 163

11 The urogenital tract, 175

12 Central nervous system, 195

Index, 214

Contents

v

A.T. Ahuja MBBS(Bom) MD(Bom)FRCR FHKCR FHKAM(Radiology),Professor, Department of DiagnosticRadiology, Prince of Wales Hospital,Hong Kong

F. Alyas MRCP, Specialist Registrar, Radiology, Guy’s & St Thomas’ NHSTrust

A.B. Ayers MD FRCR, Consultant Radiologist, Guy’s & St Thomas’ NHSTrust

D.C. Howlett MRCP FRCR, ConsultantRadiologist, East Sussex Hospitals NHSTrust, Eastbourne

D.V. Hughes MRCP FRCR, ConsultantRadiologist, East Sussex Hospitals NHSTrust, Eastbourne

E. Ruffell FRCP FRCR, Consultant Radiologist, East Sussex Hospitals NHSTrust, Eastbourne

D.F. Sallomi DMRD FRCR, ConsultantRadiologist, East Sussex Hospitals NHSTrust, Eastbourne

G.M.T. Watson MRCP FRCR, Consul-tant Radiologist, East Sussex HospitalsNHS Trust, Eastbourne

E.H.Y. Yuen MBChB(CUHK) FRCRFHKCR FHKAM(Radiology), SeniorMedical Officer, Department of Radiol-ogy, Prince of Wales Hospital, HongKong

List of contributors

vi

I am very pleased indeed to write thisforeword and to welcome the Hands onGuide to Imaging. The authors in theirpreface have correctly diagnosed twoproblems for preregistration house offi-cers (PRHO’s) and other junior doctorsworking at the boundary of direct clini-cal care for patients and radiological investigation. The first problem is therelative lack of exposure in the under-graduate curriculum to radiologicalpractice — there may be plenty of gazingat X-rays, CT scans, ultrasounds etc, but not enough attention paid to how toget to this end result. The secondproblem is the paradox in the PRHO’srole between still being in effect astudent or trainee at a very early stage ona very new and steep learning curve yetstill needing to make important and executive decisions. This paradox is

ideally resolved by junior colleagueshaving guidance, advice, support fromsenior colleagues and access to very prac-tical guidebooks written by experiencedpractitioners. This is just such a bookwhich will guide junior doctors clearlythrough the practicalities of how to startand then continue the radiological inves-tigation of a patient and what to look forwhen interpreting the image. Not onlywill it serve the trainee well, but also pa-tients, and if medical students pick it upand are stimulated to delve deeper intoradiology then that will be a well de-served bonus for the authors and editors.

D. Gwyn WilliamsDean,Guy’s, King’s and St. Thomas’ Schoolof Medicine

Foreword

vii

The authors, as busy practicing radiolo-gists, have had long experience of seeingjunior doctors juggle the tasks of theday-to-day management of patients inhospital. As the most junior members of the medical team, they are often ex-pected to have the capability of managingeveryday arrangements for investiga-tions, referrals and treatment. It can be challenging when seniors expectnewly qualified doctors to have adequateexperience.

Clinical radiology is not seen as amainstream subject in the undergradu-ate curriculum, and medical schools varyin the amount of training that theyprovide for their students in the subject.The knowledge that medical studentsgain is often obtained through clinicians,not through radiologists. This book hasbeen written to fill that gap. It is not designed to be a textbook of radiology,but has been laid out to provide prag-matic advice regarding imaging servicesspecifically for senior medical studentsand house officers. Rapid advances inimaging have added to the complexities.

The contents of the book have beenchosen following a survey identifying the

preferences of a group of senior medicalstudents and junior house officers.

Quite understandably, the text of a‘hands-on guide’ gives only a limitedamount of specialized knowledge and referral to the larger textbooks of radiol-ogy is necessary in many circumstanceswhen an in-depth knowledge is required.What we hope the reader will gain ispractical knowledge of how to obtain the best service from the imaging de-partments, how to interpret some of thebasic findings and how to avoid fallinginto the many pitfalls that are waiting forthem.

This book will not receive any awardsfor literary style. We do not apologize,for we recognize that time is short in thebusy day of a house officer and that messages have to be conveyed quickly.We have specified what is covered at thebeginning of each chapter to assist witheasy access, and used bullet pointswidely to get over the essential featuresat a glance.

We have tried to make it fun, so pleaseenjoy and learn at the same time.

Brian Ayers & David Howlett

Preface

ix

Acknowledgements

and also their radiological colleagues,Nigel Marchbank and Hugh Andersonfor access to their film collections.

The editors would like to thank LouisePellett for typing of the manuscript, NickTaylor for preparation of the illustrations

x

Abbreviations

IUCD intrauterine contraceptivedevice

IV intravenousIVU intravenous urogramMDP methylene diphosphonateMEN multiple endocrine neoplasiaMR magnetic resonanceMRA magnetic resonance

angiographyMRCP magnetic resonance

cholangiopancreatographyMRI magnetic resonance imagingMRSA methicillin resistant

Staphylococcus aureusMS multiple sclerosisNBM nil by mouthNICE National Institute for

Clinical ExcellenceNM nuclear medicinePA posteroanteriorPACS picture archiving and

communication systemPE pulmonary

embolus/embolismPET positron emission

tomographyPSA prostate-specific antigenPTC percutaneous transhepatic

cholangiographyPUJ pelviureteric junctionrtPA recombinant tissue

plasminogen activatorSAH subarachnoid haemorrhageSDH subdural haematomaSTIR short term inversion recoverySVC superior vena cava

A&E accident and emergencydepartment

AP anterior posteriorAV arteriovenousAXR abdominal X-rayBIF bifurcationCOPD chronic obstructive

pulmonary diseaseCRP C-reactive proteinCSF cerebrospinal fluidCT computed tomographyCTAP CT angiography and

portographyCTR cardiothoracic ratioCVA cerebrovascular accidentCXR chest X-rayDCIS ductal carcinoma in situDEXA dual X-ray absorptiometryDVT deep venous thrombosisECA external carotid arteryEDH extradural haematomaERCP endoscopic retrograde

cholangiopancreatographyESR erythrocyte sedimentation

rateFDG flurodeoxyglucoseFLAIR fluid attenuated inversion

recovery sequenceFNAC fine needle aspiration

cytologyGCS Glasgow coma scoreGI gastrointestinalHRCT high-resolution CTICA internal carotid arteryIRMER ionizing radiation (medical

exposure) regulations

xi

xii ABBREVIATIONS

TIA transient ischaemic attackTSH thyroid-stimulating

hormoneUS ultrasoundV/Q ventilation–perfusion

SVCO superior vena cavaobstruction

TB tuberculosis99mTc technetium-99mTCC transitional cell carcinoma

This chapter covers:• Historical perspective• Guidelines and protocols• Radiation doses• Patient safety• Informed consent• Using the imaging department

Historical perspective

On 8 November 1895 Roentgen discov-ered the new phenomenon of X-rays. On3 February 1896 the first of many lecturedemonstrations, which were popular atthe time, took place at St Thomas’ Hos-pital, London. A student’s hand was ex-amined using a 6-inch coil and 24-voltaccumulators. By October of the sameyear, the hospital had introduced a clini-cal service. This was repeated concur-rently across the UK. The take up wasrapid and exponential.

Exposure times for radiographs werein the range of 15–30 minutes. Therewas frantic activity and new designs for tubes and tables abounded. At thesame time, Edison discovered the calciumtungstate screen for recording the image,allowing shorter exposure times.

Unfortunately, the harmful adverseeffects of irradiation were not recog-nized immediately and many pioneersreceived large doses in the first fewmonths until radiation dermatitis andconjunctivitis were recognized and described. Over the next few months andyears, more serious conditions came to

light that were related to prolonged ex-posure (e.g. aplastic anaemia). By 1905,X-ray workers had begun to take mea-sures to protect themselves, but for manyit was too late and some died.

Rules and legislation were introducedto control the use of ionizing radiation in medical diagnosis and treatment butthe first real code of practice, which in-cluded protective lead aprons and screens,was not accepted until 1915. It wasclaimed that commercial interests weredelaying the development of proper pro-tection measures.

The most recent set of such regula-tions are the ionizing radiation (medicalexposure) regulations (IRMER) 2000,which are legally binding. These place aburden of responsibility on all those in-volved in the use of ionizing radiation inpatient management. Until a few yearsago, the regulations were mainly directedat those individuals providing the service,but the most recent regulations also em-phasize the need for those referring pa-tients for examinations to understand thebasis of the adverse effects of ionizing ra-diation and to ensure that on balance thepatient benefits outweigh the risks.

First of all do no harm is still a veryimportant principle.

Although more recent scientific developments have introduced imagingmodalities that do not involve ionizingradiation and are less harmful, there is aneed to continue such vigilance so thatno harm comes to patients. All imagingtechniques use some form of energy and

Chapter 1: Making the best use of the radiology department

1

2 CHAPTER 1

have the potential to cause harm if thingsgo wrong. This is the main justificationfor having centralized departments of imaging rather than allowing instruments and machines to be dis-bursed widely across hospitals or in thecommunity.

The second important reason is one ofefficiency. Modern imaging equipmentis very expensive and the highly skilledstaff who use it have to be well trained.This is a limited resource and carefulmanagement is important.

The third reason is that, over the lastdecade or so, imaging has changed dra-matically and it is only the specialists inthe field who can manage to keep up todate and to be fully informed of the newdevelopments from which patients canbenefit. At the same time, there havebeen considerable developments withinthe clinical fields so that treatmentoptions are considerably more extensiveand it is difficult for the radiologist tokeep up too.

In practice, the patient benefits mostwhen the skills and knowledge of boththe clinician and radiologist work inharmony. As you read this book you willrecognize this is a constant theme. Com-munication between the clinical teamand the imaging/radiology departmentsis absolutely essential to avoid harm topatients and to get the very best resultsfor them.

Guidelines and protocols

As medicine has become more and morecomplex it has been deemed fit todevelop guidelines and protocols to helpguide decision making as to which inves-tigation is the correct one to be under-

taken within any clinical situation. TheRoyal College of Radiologists has devel-oped guidelines and protocols for a widerange of common clinical situations, andhas published these in booklet form(Making the Best Use of a Department ofClinical Radiology).

The guidelines emphasize that everyinvestigation should be considered care-fully to ensure that it is useful — that itwill change management or, at the veryleast, lead to significant improvement inthe confidence of the clinician in thepatient’s diagnosis.

In many circumstances this does notseem to be fulfilled. To junior doctorsthis can be a confusing and stressful areaof practice. To help you there are somebasic questions that you can ask yourselfwhenever you believe that you shouldrefer a patient for imaging.• Has it been done already? The evidenceis that too many tests are repeated un-necessarily when a little effort to find theprevious results will suffice.• Does the patient need it? Will thepatient benefit from the result and if sohow?• When is the best time to perform the investigation? There is considerablepressure and indeed an expectation forimmediacy, but this is not always best forthe patient. In many circumstancesbetter results are obtained after the acuteevent has subsided, when investigationparameters can be optimized. A goodopinion cannot be obtained from poorimages! So-called ‘routine’ supine chestX-ray (CXR) on admission through theaccident and emergency department(A&E) is an example.• Is this test the best one? The range ofpossibilities is often wide. As a youngdoctor, you cannot be expected to know

MAKING THE BEST USE OF THE RADIOLOGY DEPARTMENT 3

about or understand them all. Theguidelines will help in common situations but otherwise you will needadvice — ask the radiologist.• Is the problem and the question to be an-swered clear? The radiologist needs tounderstand these so that the right exam-ination can be undertaken. The wrongtest will give the wrong result and notbenefit the patient. If you are not sure,discuss it with the radiologist.

Radiation doses

To give you some idea of the range of ra-diation doses that radiological investiga-tions entail, Table 1.1 lists a few.

Background irradiation varies, butanother way of looking at this is to re-member that the dose received from amodern CXR is equivalent to the extraradiation received during a couple offlights to Majorca!

Patient safety

Radiation is not the only risk to patientsafety in an imaging department. Othersthat you should be aware of include thefollowing.

Identification

Unfortunately, identification errorsabound in practice. Fortunately, few leadto actual harm but some do. Identifica-tion errors occur at any point in theprocess from request to report transmis-sion to the patient. The responsibilitystarts with the referring clinician toensure that the patient’s personal infor-mation provided is accurate. Further

responsibility lies with the radiology department and its staff — the radiogra-phers, radiologists, clerks, typists andadministrators — to ensure that the filmsor images and the report are allocatedcorrectly to a single patient.

Misidentification is the most commoncause for failure to find previous ex-aminations, and this leads to delay and tounnecessary repeats. One hopes thatcomputerization of patient records willhelp to overcome this problem in thefuture.

Iodine hypersensitivity

Many X-ray contrast agents containiodine and there is a known incidence of hypersensitivity that can lead todeath.

The first thing is to be sure in yourmind that this risk is worthwhile. Applythe questions set out previously.

The second is if it is worth the riskthen let’s do all we can to minimize thatrisk. Patients should be told if a cliniciansuspects iodine hypersensitivity. The ra-diologist and radiographer should alsobe informed of the detailed events thathave led to this conclusion. In many cir-cumstances, alternative investigationscan be suggested. If an iodine-basedcontrast examination is essential, thereare steps that can be taken to reduce thelikelihood of a ‘serious untoward event’occurring.

The range of investigations at the ra-diologist’s disposal mean that it is now arare event to expose a patient with aknown hypersensitivity to iodine to anexamination requiring an iodine-basedcontrast medium.

This topic is referred to again inChapter 2.

4 CHAPTER 1

Nephrotoxicity (see also Chapter 2)

Contrast media offer a challenge to the kidneys, particularly when injectedintra-arterially, and this is dose depen-dent. The usual half-life of injected con-

trast is 2 hours. Particular problems arise in the elderly and in dehydrated patients, where the level of renal failure and dehydration are often under-estimated. Diabetic patients with mild renal failure are susceptible. These

Table 1.1 Typical doses from diagnostic medical exposure. (Modified from Royal College ofRadiologists handbook, Making the Best Use of the Radiology Department, 4th edn.)

Diagnostic procedure Typical effective Equivalent no. Approx. equivalentdose (mSv) of chest X-rays period of natural

background radiation

Radiographical examinations

Limbs and joints (except hip) <0.01 <0.5 < 1.5 days

Chest (single PA film) 0.02 1 3 days

Skull 0.06 3 9 days

Thoracic spine 0.7 35 4 months

Lumbar spine 1 50 5 months

Hip 0.4 20 2 months

Pelvis 0.7 35 4 months

Abdomen 0.7 35 4 months

IVU 2.4 120 14 months

Barium swallow 1.5 75 8 months

Barium meal 2.6 130 15 months

Barium follow-through 3 150 16 months

Barium enema 7.2 360 3.2 years

CT head 2 100 10 months

CT chest 8 400 3.6 years

CT abdomen or pelvis 10 500 4.5 years

Radionuclide studies

Lung ventilation (133Xe) 0.3 15 7 weeks

Lung perfusion (99mTc) 1 50 6 months

Bone (99mTc) 4 200 1.8 years

Abbreviations: CT, computed tomography; IVU, intravenous urogram; PA, posteroanterior.UK average background radiation = 2.2 mSv/year; regional averages range from 1.5 to 7.5 mSv/year.


factors mean that patients over 70 yearsare likely to be at increased risk. Dehy-dration is also a problem in patients withmyeloma.

A number of measures can be taken toprevent contrast media nephrotoxicity ifwe know about it in advance (e.g. extra-cellular volume expansion and use of lowosmolar contrast media).

It is not uncommon for examinationrequests to be made when patients areunwell. These are circumstances whenthe timing of the investigation should begiven serious consideration. Of course,on some occasions it is essential to per-form an examination immediately, butthe additional risk must be recognizedand managed.

Alternatively, the reduced benefit ofperforming an examination quickly witha poor result must be weighed against thebenefits of waiting and performing theexamination with the patient’s conditionimproved and the imaging circum-stances maximized, giving better results.(This applies equally to non-contrast examinations.)

Drug interactions

There are some drugs that interact in anadverse way with contrast media andtheir excretion. This risk needs to be assessed before booking, not when thepatient arrives for an examination. Youshould at least remember to tell the department before booking if your pa-tient is taking metformin or interferonbecause of their potential nephrotoxicity(see Chapter 2).

Concurrent administration of nephro-toxic drugs, such as gentamicin, andnon-steroidal anti-inflammatory drugsshould be avoided.

Asthma

It can be very difficult for the radiologistto tease out whether it is true that apatient has asthma or some other chronicrespiratory complaint when he or shearrives at the department for an exam-ination. If the patient is suffering fromtrue asthma and is taking steroids it mustbe questioned whether a contrast ex-amination is appropriate, as this mayprovoke an acute exacerbation. If it is, it may be necessary to give furthersteroid prophylaxis. However, alterna-tive methods of investigation should beconsidered first.

It is much better for the patient if thisissue has been addressed before an ap-pointment is made.

Infection

Sadly, infection is a major cause ofconcern in modern hospitals, and de-partments of clinical radiology are noexception.

Patients attending imaging depart-ments expect to be protected from pos-sible cross-infection. In order to do this,those patients with infections, who are arisk to other patients and staff, need to beidentified before coming for an appoint-ment or examination (e.g. tuberculosis,hepatitis, methicillin resistant Staphylo-coccus aureus [MRSA]). It beggars beliefthat wards can nurse MRSA patients inside rooms to protect the rest of the wardpatients, but without notification sendpatients for X-rays that entails themsitting in open waiting areas with otherpatients — sometimes those from thesame ward!

The other side of the coin is that pa-tients who are particularly susceptible to

6 CHAPTER 1

contracting infections (e.g. those withsevere lack of immunity) require extraprotective measures when particularprocedures are carried out.

Staff in the department are also entitled to know when extra risks arise so that additional protective measurescan be taken (e.g. HIV infection).

At present, we rely very heavily on thedoctors and nurses looking after such pa-tients to inform us, but this does notalways happen. It is to be hoped that, intime, such conditions will be highlightedautomatically through the electronicrecord system when a referral is made sothe appropriate action can be taken.

Informed consent

Attitudes to informed consent havechanged dramatically in the last fewyears. It is clearly a clinical decision as tohow much information is given to apatient but, in general, informed consentmeans that the patient is in possession ofthe full facts and that they understandthe implications of what is planned forthem. When it is necessary to obtainconsent in writing is a matter of localpolicy but it is advisable, when consenthas been obtained verbally, that a recordof the conversation is made in thepatient’s notes.

In general, written consent is not required for most radiological ex-aminations but it is required for many interventional procedures. Verbalconsent should be obtained for any invasive procedure, which includes intravenous injection.

For interventional procedures such asangioplasty or biopsy, written consentshould be obtained by a professional who

understands the procedure and its complications fully. Ideally, that personshould be capable of performing theprocedure. Written information materialis very helpful and is widely available.

Do not mislead your patients if youare not sure what a particular procedureentails. You will not be criticized for notknowing, but you will be deemed to be inthe wrong if the patient is not fully in-formed before any act that potentiallyposes a risk to him or her is undertaken atyour behest. Most departments will havewell-developed procedures — you justneed to learn about them and use them.If in doubt, consult a senior colleague orradiologist.

Pregnancy and the fetus

This issue is covered in Chapter 2.

Confidentiality

You will have received some instructionduring your undergraduate years re-garding confidentiality and your own be-haviour. There is often an expectationthat anyone can ring up the radiology de-partment and find out the result of apatient’s examination without any safe-guards and without any consideration ofwho else may be within earshot of thephone. Compare this with getting infor-mation about your own account at thebank!

Confidentiality applies to all areas.

Using the department

Making referrals

If you regard every request for imaging


as a clinical referral for an expert special-ist opinion, you will be taking a largestride towards ensuring that you get thebest service from the imaging depart-ment for your patients.

Good communication of your pati-ent’s details and your expectations is essential. Throughout this book you willbe given tips as to where and when this isparticularly important. As with manyclinical situations, direct conversationscan create miracles!

Delegation of responsibility

Radiologists carry the ultimate responsi-bility for patient care, both legally andclinically, when imaging takes place. Inmany circumstances this is delegatedwithin protocols to radiographers andtechnicians. House officers need to un-derstand and recognize these limita-tions. Do not be surprised if theradiographer wishes to refer to a moresenior source. They are not being ob-structive but simply keeping to theguidelines that they have to work within.Some referrals have to be made on a con-sultant to consultant basis in many hos-pitals. There are good reasons for this.

Guidelines and protocols are devel-oped to provide a framework for all to work within, but they can be variedwhenever the individual patient needdemands it. Many of these variations can be discussed and agreed at regularclinicoradiological or multidisciplinarymeetings and your attendance at these isstrongly recommended.

If any situation is proving difficult, re-ferral directly to the radiologist is recom-mended. A joint discussion between theclinician and radiologist provides thebest solution.

Interpretation of the image

Interpretation of the image is usuallyconducted by a specialist radiologist anda formal report is provided. There willbe many circumstances in which a radi-ologist is not available and you have torely on your own efforts. When this is thecase, remember that it is a requirementunder the IRMER legislation to make arecord of your interpretation in thenotes. Be very careful about the way thatyou record verbal discussions. If youquote a colleague’s opinion in the notes,be sure to check that you have under-stood them properly. (Note: although ra-diographers may be very experiencedthey are not medically qualified — thefinal responsibility is yours unless yourefer to a senior colleague or radiologist.)

Formal interpretation sometimestakes time because of the need tocompare with previous examinations, to consult a colleague or to refer to textbooks.

In many cases away from A&E, dis-cussions about patients can take place atregular meetings between clinicians andradiologists. These are highly re-commended, both from a patient man-agement point of view but also for everyone’s education. The radiologistwill learn from the feedback you givethem of the final clinical outcome. Donot spare their blushes!

Priorities

It is sometimes difficult for clinicians tounderstand why their most urgent andimportant referral is not seen in the samelight by the radiology department. It is aconstant challenge for staff in imagingdepartments to arrange lists of patients

8 CHAPTER 1

referred by a number of different clini-cians whose sole interest is in their ownpatients.

If your patient is particularly sick letthe radiographer know, so that delaysand time spent in the department can beminimized.

The key to success is clear communi-cation of the real need without exag-geration. This applies to out-of-hoursrequests particularly, when the need for urgent or emergency examinationshould be clearly understood and agreedby all concerned.

From time to time we all get it wrong.

Audit

Many clinical audit projects requireinput from imaging departments andvice versa. The data to be used and themechanisms for collection should beagreed in advance by all parties.

Research

Most hospitals have governance arrange-ments that need to be followed in

order to conduct a piece of research.They should tell you how to arrange forany additional imaging and whetherethical permission is necessary. Man-agers will need to be involved to sort out any additional funding requirement.

One of the best ways to understand theworkings of a radiology department andto see what has to be done to patients toobtain an image (e.g. barium enemas inthe elderly and infirm) is to come, visitand see for yourselves. Too many stu-dents fail to take up this offer beforegraduation. If you are one of them, do not hesitate in coming forward now. You will benefit and so will your patients.

Further reading

Burrows EH. Pioneers and Early Years:A History of British Radiology.Channel Islands: Colophon, 1986.

Making the Best Use of a Department of Clinical Radiology: Guidelines forDoctors, 5th edn. London: RoyalCollege of Radiologists, 2003.

This chapter covers:• Conventional X-ray (plain film)• Contrast studies (barium andwater-soluble)• Ultrasound• Computed tomography• Magnetic resonance imaging• Nuclear medicine• Positron emission tomography• Picture archiving and communi-cation system

Introduction

There are a number of different imagingmodalities that you will become familiarwith during medical school and housejobs. Awareness of the relative strengthsand weaknesses of these techniques willhelp you to decide when each should beused. It is important to be aware thatsome procedures involve ionizing radia-tion (e.g. conventional X-rays, CT, con-trast studies). Always consider beforerequesting a procedure that involves ionizing radiation:• Will it effect management?• Is there an appropriate alternative thatdoes not involve ionizing radiation (e.g.magnetic resonance imaging [MRI] orultrasound [US])?

These alternatives should particularlybe considered in the young, fertile orpregnant. These issues are important inlight of the IRMER, which try to limitthe utilization of medical radiation. Ifyou are unsure about which examination

is appropriate, liaise with the radiologydepartment for advice.

Conventional X-ray (plain film)

This uses a tungsten source to generateX-rays. The X-rays are radiated throughthe body part of interest and on to a filmcassette or digital X-ray camera posi-tioned behind the body part. A specialphosphor coating inside the cassetteglows and exposes the film. The result-ing film is then developed like a photo-graph. Many departments have a digitalX-ray camera rather than film cassette,which contains a similar phosphor andconverts the X-rays to an electron beamthat drives a TV monitor from which adigital picture can be viewed. Thisdigital image is printed on to film orarchived into computer memory.

The resulting image is a two-dimensional representation of a three-dimensional object. It depends on how attenuating to X-rays the tissue of interestis, which is related to the thickness,density and atomic number. It alsodepends on which tissues are superim-posed on each other. The varying attenua-tions are represented by shades of grey onthe film or monitor; white being the mostattenuating and black the least. Essential-ly, there are six different attenuations thatyou can see on plain films, in order of in-creasing greyness: air (black); fat and softtissue; bone; contrast; and metal (white).

Chapter 2: Imaging techniques

9

10 CHAPTER 2

You will find that you request certaintypes of X-ray commonly (e.g. CXR, ab-dominal X-ray [AXR]), and these will bedealt with later in the book. Some mayhave a high dose (see Chapter 1 for arange of doses for common proceduresinvolving ionizing radiation). Note theparticularly high doses associated withlumbar spine X-ray, CT and bariumenema.

Pregnancy and ionizing radiation

Radiation is teratogenic to the fetus soavoid if at all possible in those who are, ormay be pregnant (particularly in the firsttrimester).• Check with women of reproductiveage if they are pregnant or have a delayedperiod prior to exposure to ionizing radi-ation. You can use a pregnancy test if youare unsure.• Delay investigations if possible andlet the department know if there is a pos-sibility of pregnancy.• Use a non-ionizing alternative (MRI,US).• In emergencies, CT head or CXRgives a relatively low dose to the fetus.Ask for radiological advice if you areunsure.• Record all decisions in the notes.

Contrast studies

Any two organs of a similar density andaverage atomic number are indistin-guishable on an X-ray. Contrast mediaare therefore necessary to create an artifi-cial contrast between the organ to be diagnosed and the surrounding tissue. Italso opacifies normal tubular structures

such as bowel, blood vessels and urinarytract. Contrast is commonly used withfluoroscopic procedures (screening),plain films (intravenous urogram [IVU])and CT.

All contrast media are based on theprinciple of a non-toxic suspension orsolution that contains a significant pro-portion of elements with a high atomicnumber. Barium and water-soluble con-trast are the two main agents.

Barium

Barium sulphate is an inert contrastagent used to opacify the gastrointestinaltract. It comes in a variety of suspensionsdesigned for specific purposes. Try to bespecific as to which region of the bowelyou would like evaluated, as this willdictate the type of barium preparationused. Discuss with the radiologist if youare not sure.

Barium examinations

• Barium swallow.• Barium meal: rarely performed withthe advent of endoscopy (see later inbook).• Small bowel follow-through/enema:used for evaluating small bowel.• Barium enema.

Some examinations require a lot of movement (barium meals andenemas) and may not be appropriate in the frail or elderly. Consider alterna-tive investigations such as colonoscopyor CT.

Important points

• Barium is contraindicated in sus-pected perforation (causes a high-

IMAGING TECHNIQUES 11

mortality peritonitis or mediastinitis).Suspected perforation is an indicationfor a water-soluble agent.• Aspiration may occur during bariumswallow and requires urgent physio-therapy. Arrange the same day.• Barium enema is contraindicated if adeep rectal biopsy has been performedvia rigid scope within the previous 5 days.• Large bowel barium studies requirepreparation. Laxatives used for bariumenemas can cause dehydration. Consideradmission for preparation in the elderlyand infirm.• Barium causes artefact on CT, makingit difficult to interpret. This will delayuse of CT by up to 2 weeks.

Water-soluble contrast agents

These are iodine-based clear viscousliquids. They can be classified into theolder ionic and newer non-ionic agents.Ionic agents, although cheap, have a farhigher incidence of side-effects and areno longer used intravenously.

Uses of ionic contrast agents (e.g. Gastrografin, Urografin)

• For large bowel evaluation rectally inpatients with suspected perforation or atrisk of perforation (e.g. colitis).• Can be injected into T-tube, into afistula (fistulogram) or sinus (sinogram).• To check for leaks from an ileal pouchor bowel anastomosis.• Only used orally as a dilute bowelpreparation in CT. They cause a chemi-cal pneumonitis if aspirated.

Uses of non-ionic contrast agents

• Can be injected intravenously (e.g.

IVU, CT) or intra-arterially (e.g. angiogram).• Contrast swallows in suspected per-foration or in children.

Side-effects of water-solublecontrast agents

• Nephrotoxicity following intravenousinjection (avoid these studies in renal impairment):

– Increased risk in renal impairment,diabetes mellitus, dehydration, in theelderly and myeloma.– Where appropriate include detailsof the patient’s renal function on therequest form if requesting a pro-cedure that may need intravenous contrast.

• Metformin and intravenous contrast:– These patients are at risk of lacticacidosis after intravenous contrast administration.– Check renal function before procedure. If it is abnormal patientsshould not be on metformin anyway(remember it is renally excreted).– Metformin should be stoppedbefore and for a period after intravenous contrast (check in-dividual department for protocol). Donot restart unless renal function isnormal.

• Anaphylactic reactions:– Let the department know if there isa history of iodine allergy.– Reactions include rash and wheeze.Severe reactions are rare (1 in 1000),as is death (1 in 12 000–40 000).– Premedication with steroids issometimes used in those with pre-vious reactions or at high risk, butliaise with the department.

• Extravasation/phlebitis at injection site.

12 CHAPTER 2

Ultrasound

This uses ultra-high-frequency soundwaves generated from a transducer in theUS probe, which penetrates tissues andis reflected back. An image is created, de-pending on the reflecting and absorbingproperties of tissue. The image is dis-played as a grey scale on a monitor.Objects appear as bright (hyperechoic,e.g. gallstones) if highly reflective or asdark (hypoechoic, e.g. water) if soundpasses freely through. Isoechoic struc-tures are similar in appearance to sur-rounding tissue. Doppler US is a usefuladjunct, which estimates velocity ofmoving structures and has vascular applications. Patient preparation is often required, especially in the upperabdomen — liaise with the department.

Advantages of US

• No ionizing radiation.• Portable and can image in any plane.• Real time: good for mobile structures(e.g. heart valves) and guiding drainageor biopsy procedures.• US has a wide range of applicationsbut is particularly useful in obstetrics,children and vascular evaluation.

Disadvantages of US

• Operator dependent.• Limited by body habitus, poor visualization of deep structures in theobese.• US cannot scan through gas. This is aparticular problem in the abdomen withexcess bowel gas. The pancreas andretroperitoneum in particular are oftenobscured.• US cannot penetrate through bone.

Computed tomography

Modern scanners consists of a rotatingbeam of high-energy X-rays and a 360°array of detectors. The patient slidesthrough this rotating array and the re-sulting image is a series of vertical slices,representing the varying densities oftissue across the slice in the patient. Adetailed knowledge of cross-sectionalanatomy is required for interpretation ofthese images.

The density of an object on a CT scan is measured relative to water inHounsfield units ranging from approxi-mately –1000 (air: low density) to +1000(bone: high density). As there are about2000 different Hounsfield numbers andthe human eye can only appreciate about10–15 different grey scales, scans arewindowed according to the particulartype of tissue that needs to be examined.This improves the contrast betweentissues and this is the advantage of CTover other imaging modalities. Thecommon windows most used are lung,soft tissue, brain and bone.

The image is displayed on a grey scalewith more dense matter appearing aswhite (bone, blood), less dense matter asblack (air, fat), and soft tissue appearingas shades of grey. Most CT images inthis book are on soft-tissue windows butexamples of lung window (Chapter 3,Fig. 3.4a) and bone window (Chapter 12Fig. 12.2) images are included.

Images can be obtained rapidly (e.g. asingle breath hold for the whole chest).

Modern scanners have a high enoughresolution to perform angiography afteran intravenous injection of contrast.They can also scan an entire volume ofa patient (e.g. knee) and this can beviewed in any plane, which is useful in


orthopaedics, as a three-dimensionalimage.

Patient preparation

Different departments have varying pro-tocols. Abdominal and pelvic examina-tions usually need oral contrast (diluteionic) for bowel opacification and intra-venous non-ionic contrast for opaci-fication of vasculature and viscera. Remember previous comments aboutiodine allergy and renal impairment.The patient may need to tolerate oralcontrast. Lack of oral contrast may limitthe accuracy of the examination. Con-sider this if your patient is vomiting or nilby mouth (NBM) (for example suspect-ed perforation, or for an acute abdominalproblem that may need surgery).

Advantages of CT

• Good contrast between tissues anduseful in assessment of abdomen, retro-peritoneum, pelvis and mediastinum.• Not degraded by bowel gas.• Highly sensitive in detecting intra-cranial blood.

Disadvantages of CT

• CT is a relatively high-dose procedure(see Chapter 1).• Recent barium studies obscure imagesof the abdomen and pelvis. There mayhave to be a 2-week delay betweenstudies. Bear this in mind if CT may berequired for your patient.• Artefact is caused by high-densitymetal in teeth and joint replacements.This may limit the diagnostic accuracyof neck and pelvic examinations.• It may be difficult to scan dense bonyareas for the same reason (e.g. posteriorfossa).

• The accuracy of CT is limited if thepatient cannot hold his or her breath orlie still.• Most CT scanners have size andweight limits.

Magnetic resonance imaging

All hydrogen nuclei have a physicalproperty called a magnetic moment orspin if they are put in a strong magneticfield. When combined with an electro-magnetic pulse this produces a signal,which can be measured, and an imagegenerated. Each slice of the MR image isessentially a map of the distribution ofthis property of hydrogen nuclei in thevarious tissues of the body.

The main sequences are T1 and T2.T1-weighted sequences show fluid aslow signal (dark) and fat as high signal(white). On T2 weighting, fat is highsignal and fluid is very high signal. ASTIR sequence can be used to suppressfat and highlight oedema changes intissues.

Gadolinium-based contrast is a non-iodine-based paramagnetic compound,sometimes used to alter the T1 signal oftissues to aid diagnosis. Although appar-ently not nephrotoxic, it should be usedwith caution in renal impairment.

Advantages of MRI

• No ionizing radiation.• Multiplanar capabilities.• High-resolution high-contrast imagesof the internal organs.• Widely used in brain, spine and jointimaging.• Useful in bony areas such as the spineand posterior fossa and pelvis, where CTis often limited.

14 CHAPTER 2

• Magnetic resonance angiography(MRA) or venography can be performedwithout contrast injection (useful inthose who have an iodine allergy or renalimpairment).

Disadvantages of MRI

• Systems are expensive and not widelyavailable.• Scanners are noisy and the patientmay have to stay still for a long period oftime. If they move, part of the scan mayhave to be repeated.• High incidence (up to 10%) of scanfailure resulting from claustrophobia.The incidence of this is decreasing innewer, more open machines.• Orthopaedic hardware (screws, plates,artificial joints) in the area of a scan cancause severe artefact.• Not as sensitive in detecting blood inacute cerebral trauma.

Contraindications

These are related to the strong centralmagnetic field and the ability to moveferromagnetic objects at considerablespeed. Patients with the followingshould not enter the scanning room:• Pacemaker• Aneurysm clip• Metallic heart valve• Cochlear, otological or ear implant• In those who work with metal or whohave had a shrapnel injury.

Some surgical prostheses (e.g. screws,rods and plates) need a waiting period ofat least 6 weeks after surgery to allow forpostoperative fibrosis before scanning.

Always consult with the MR depart-ment about device safety. Newer pros-theses may not be ferromagnetic andhence safe in the scanner.

Nuclear medicine

Nuclear medicine (NM) provides func-tional information but relatively pooranatomical detail. It uses physiologicallyactive molecules, which are labelled withradionuclide (a molecule that emits radioactivity). For example methylenediphosphonate (MDP) labelled withtechnetium (99mTc). The labelled mol-ecule is called a radiopharmaceutical.Technetium is the most commonly usedradionuclide and emits gamma rays.

The radiopharmaceuticals are in-jected (e.g. bone scan) or inhaled (ven-tilation/perfusion scan) and allowed to distribute where these molecules arenormally utilized (e.g. the osteoblasts in bone in the case of 99mTc MDP inbone scans). The distribution and con-centration of these molecules in thebody can be detected by the radiationemitted by the radionuclide, which is de-tected by a device called the gammacamera. A grey scale image is generated,showing the concentration and distribu-tion of the radiopharmaceutical in thebody.

Advantages of NM

• Provides functional information.• Can be used safely in renal impair-ment.

Disadvantages of NM

• Poor anatomical resolution.• High dose (see Table 1.1).• Some examinations may be limited byavailability of radionuclides.• Patients may need to lie relatively stillfor long periods.


Positron emissiontomography

There are only a handful of institutionsthat can perform positron emission tomography (PET). It uses positron (a positive electron) emitting radionu-clides, labelled on to metabolically activemolecules; 18 fluorine-fluorodeoxyglucosebeing most commonly used. This is injected and is taken up in proportion tothe metabolic activity of the tissue. Verymetabolically active tissues, such ascancers, take it up avidly. The positronsgenerate two high-energy gamma rays at180° to each other. This allows accuratelocalization by detectors on a dual-headed PET scanner to visualize the distribution of this metabolically ac-tive tissue. It is used commonly instaging of lung cancer, melanoma and lymphoma.

Picture archiving andcommunication system

These are computer-based systems,which eliminate film. If your hospitalhas a picture archiving and communica-tion system (PACS), all of the imagingmodalities mentioned may be stored oncomputer memory, which can be viewedas and when required on a computermonitor rather than printed on to conventional plain film. These systemsconsist of:• Computer memory: storage device (alarge amount of long- and short-termmemory).

• Computerized radiography: takingimages in a digital format so that theycan be stored on a computer memory.This is relatively easy for CT, MR andUS, where the images are generated bycomputers. Many institutions are nowalso taking plain films with digital X-raycameras.• Monitors and viewing software: forviewing and manipulating image con-trast, size and serial comparison.• Network: to send the images to whereyou want to see them in the hospital.

Advantages of PACS

• Easier access.• Cost saving.• No more lost films.

Disadvantages of PACS

• Initial cost.• System failure visible and cata-strophic.• Reduced discussion between radiolo-gists and clinicians.

Further reading

Making the Best Use of a Department of Clinical Radiology: Guidelines forDoctors, 5th edn. London: RoyalCollege of Radiologists, 2003.

Thomsen HS, Morcos SK. Contrastmedia and the kidney: EuropeanSociety of Urogenital Radiology[ESUR] guidelines. British Journal ofRadiology 2003; 76: 513–18.

This chapter covers:Common conditions• Lung cancer, lung metastases,lymphangitis carcinomatosa• Chronic obstructive pulmonarydisease, sarcoidosis, tuberculosis,bronchiectasis• Common clinical findings:pleural effusion, pneumothorax,pneumonia• Asbestos-related lung disease, interstitial fibrosisCommon presentations in whichimaging can helpSymptoms of lung disease are notoften disease-specific and include:• Shortness of breath• Chest pain, either pleuritic ornon-pleuritic• Haemoptysis is a symptom thatrequires investigation: commoncauses include lung cancer and tuberculosis• Productive cough is common withacute infection and chronically is a characteristic feature ofbronchiectasis• Dry cough is present in many conditions, including interstitial fibrosis• Wheeze is a non-specificsymptom characteristic of asthmabut also seen in other conditionssuch as heart failure, inhaledforeign bodies and some centrallung cancers

Imaging strategy

CXR

Indications

One of the most common requests youwill make will be for a CXR. A list of in-dications would be very long and notvery useful, so the best approach to de-termining whether to request a CXR isto ask yourself how it will change yourmanagement of the patient. If it willalter management, then it is justified.

Standard views

PA

A standard CXR is performed with the patient standing facing the X-raycassette, which contains film or com-puterized radiography plate. The X-raysource is behind the patient at a fixed dis-tance. The X-ray beam passes from pos-terior to anterior (PA). This techniqueminimizes magnification of anteriorstructures. The size of the heart and mediastinal structures can be assessed on a PA image and compared to similarprevious examinations.

AP

If the patient is too ill or immobile toobtain an erect PA view, an AP film canbe obtained. The X-ray cassette is placedbehind the patient. The X-ray beampasses from anterior to posterior (AP).

Chapter 3: Respiratory system

16

RESPIRATORY SYSTEM 17

The patient will often be lying on atrolley or a bed and this causes magnifi-cation of anterior structures by a variabledegree so an accurate assessment of thesize of the heart and aorta cannot bemade, although if they look normal insize, they are!

Lateral

Lateral chest films are of limited value,and tend to be over-requested. They areuseful for the assessment of areas hiddenon a PA film by the diaphragm, heart orbone. Ask a radiologist for advice.

US

This is a valuable technique in the as-sessment of the size and position ofpleural effusions, and can be used toguide aspiration of pleural fluid. It canbe particularly useful if loculation of thefluid has occurred because of previousdisease or intervention.

CT

Two types of scan of the chest are performed for assessment of lungdisease: standard and high-resolutionCT (HRCT) scans.

Standard scans with intravenous (IV)contrast are used to stage lung tumours,investigate lung masses and to assess themediastinum and pleura. They are alsoperformed in the staging of other malig-nancies to detect metastases or assesssites of involvement in lymphomas.

High-resolution scans demonstratefine detail of the lung structure and areused in the assessment of interstitiallung disease and air-space disease. Air-space disease involves the lumen of the

bronchial tree and is usually in thealveoli, as is seen, for example, in pneu-monia and pulmonary oedema. Intersti-tial diseases involve the lung structure(e.g. sarcoidosis, some pneumonias andinterstitial fibrosis). Characteristic pat-terns of involvement are often seen onHRCT and a firm diagnosis can often bemade.

The radiologist/radiographer willneed to decide which technique to use inadvance and therefore needs to be fullyinformed of the clinical problem to beaddressed.

PET

This is a highly specialized investigationperformed in a few centres only. Thetechnique identifies areas of increasedglucose metabolism and, as malignantlung tumours have high levels of glucosemetabolism, PET scanning is used forstaging prior to surgery and for follow-up when available.

MRI

This has only a limited role at the presenttime. It is sometimes useful in assessingbrachial plexus and chest wall involve-ment by tumours, although the patient’ssymptoms are often the most reliable evidence of chest wall involvement.

Carcinoma of the lung

Clinical presentation

Common clinical presentations ofprimary tumour are:• A coincidental finding of a mass onCXR

18 CHAPTER 3

• Cough, haemoptysis, wheeze, pneu-monia: often indicative of a centraltumour• Pleuritic chest pain, brachial plexuspain and/or Horner’s syndrome (Pancoast’s tumour) that may suggest aperipheral tumour• More general symptoms (e.g. short-ness of breath, cough)• Paraneoplastic syndromes (e.g. inap-propriate antidiuretic hormone secre-tion), non-metastatic neuromyopathicpain, clubbing and hypertrophic osteoarthropathy, thrombophlebitismigrans and cachexia• Metastatic disease, depending on thesite (e.g. brain or bone).

If you suspect that your patient mayhave carcinoma of the lung, initial inves-tigations will be determined by the ap-pearances of the CXR.

Appearance on CXR

Common appearances seen on CXR are:• Lung mass: varying in size and shape,with or without cavitation. Peripheralconsolidation or collapse may occurdistal to a central stenosing tumour. Aslowly enlarging cavitating mass is aclassic presentation of a squamous cellcarcinoma of the lung (Fig. 3.1).• Non-surgical lobar collapse in adults:look for localized central bulging of the

Fig. 3.1 Large left-sided cavitating squamous cell carcinoma is present, which contains an air–fluid level (white arrow).


collapsed lobe, as this may be a tumour(S-sign of Golden; see Fig. 3.2).• Pleural effusion: a large unilateralpleural effusion may mask an underlyingtumour.

Fig. 3.2 Right upper lobe collapse secondary to a central occluding carcinoma.Note the trachea is deviated to the right with the right hilum elevated and not visualized, consistent with right upper lobe volume loss. There is characteristicconvex bulging of the border of the collapsed right upper lobe due to an obstruct-ing tumour (white arrows), the so-called S-sign of Golden.

Tips

• Always look for any associated fea-tures that will confirm the diagnosis ofmalignancy, such as evidence of local

20 CHAPTER 3

Further investigations

• Bronchoscopy: useful to obtain a tissuediagnosis, particularly for centrallesions.• CT scan for preoperative staging (Fig.3.4a,b): staging will assess the size of theprimary tumour, hilar and mediastinalnode involvement and the presence ofdistant metastases in the liver or adrena-ls. Assessment of involvement of centralstructures (important if surgery is contemplated) such as the pulmonaryarteries, main bronchi and heart will alsobe made.• CT and CT-guided biopsy: for caseswhere knowing the tissue type will affectmanagement. This usually arises when

Fig. 3.3 Magnified view of a right upper zone carcinoma demonstrates erosion ofthe inferior cortical margin of the posterior third rib (arrows).

chest wall or bone invasion (Fig. 3.3),metastases in the lungs or bones, enlarged hilar and/or mediastinalnodes.• Always suspect a central bron-chogenic tumour if a patient presentswith lobar collapse, if pneumoniadoes not clear or if pneumonia arisesin the upper lobes.• Always check the apical regions ofthe lungs carefully.• An unusual presentation is that ofpatchy or confluent nodules and/orconsolidation unilaterally or bilat-erally seen in broncho-alveolar cell carcinoma (< 6% of lung carcinomasbut may be increasing in incidence).


Fig. 3.4 (a) An axial CT section on lung window settings demonstrates a periph-eral carcinoma in the left upper lobe (white arrow). (b) In the same patient as (a),post-contrast CT on mediastinal windows demonstrates enlarged nodes at theaorto-pulmonary window (white arrow) and the left hilum (black arrows).

a

b

22 CHAPTER 3

Fig. 3.5 Widespread soft-tissue metastases (cannon ball) of varying size aredemonstrated throughout both lungs in a patient with metastatic carcinoma ofthe colon.


the primary tumour has been shown tobe inoperable on CT scanning (Table3.1).• PET: to aid diagnosis and to stagedistant nodes prior to surgery.

Lung metastases

The lungs are a common site ofhaematogenous metastatic disease.Common primary sites include:• Breast• Kidney• Head and neck• Colorectal.

CXR

Several patterns are seen:• Nodules: one or more of varying sizes(Fig. 3.5)• Poorly defined soft-tissue masses• Miliary metastases: tiny widespreadsoft-tissue metastatic nodules, all ofsimilar size.

Comparison with previous films orreference to previous reports is often rewarding.

CT

CT may be useful if there is doubt on theCXR. It is a very sensitive technique and often demonstrates more metastasesthan are visible on the CXR, even in retrospect!

Table 3.1 Useful information regardingpatients referred for lung or pleural biopsy.

Can be used for:Focal lung lesions > 8 mm diameter, depending

on site of lesionFocal pleural lesions or diffuse pleural

thickening

ContraindicationsPatient unable to give informed consent or

unable to cooperateBleeding diathesisSevere COPD/emphysema unable to withstand

pneumothorax — ask the chest physician!

Patient preparationNil by mouth (4 hr)Intravenous accessConsentCoagulation screen

ComplicationsHaemoptysis as a result of intrapulmonary

haemorrhagePneumothorax. Small pneumothoraces are

common.Aspiration and/or chest drain arerarely needed

24 CHAPTER 3

Lymphangitis carcinomatosa

Involvement of the central lymphaticchannels of the chest by metastaticdisease results in lymphangitis carcino-matosa, whether the primary tumour isin the chest or remote. Common primarysites producing lymphangitis carcino-matosa are breast, cervix, lung, pancreas,prostate, stomach and thyroid.

Changes become apparent in ad-vanced cases on CXR and on CT scanning.

CXR

CXR may show (Figs 3.6 & 3.7):• Reticulation and irregular septal lines• Soft-tissue nodular densities• Enlarged hilar nodes (< 50%)• Enlarged mediastinal nodes• Unilateral or bilateral distribution• Pleural effusions.

CT

HRCT is valuable in establishing the diagnosis of lymphangitis carcinomatosa

Fig. 3.6 A normal chest radiograph in a patient with known renal cell carcinoma.


if there is uncertainty over the CXR appearances.

Chronic obstructivepulmonary disease

The term chronic obstructive pulmonary disease (COPD) is used todescribe what is often a combination of chronic bronchitis and emphysema.

These clinical syndromes lead tochronic, mostly irreversible, airways ob-struction. Symptoms include chroniccough, sputum production and short-ness of breath.

Emphysema

Emphysema is a condition in whichthere are permanently enlarged airspaces distal to the terminal bron-

Fig. 3.7 Two months later, the same patient as in Fig. 3.6 developed symptoms ofshortness of breath with evidence of lymphangitis carcinomatosa on CXR. Thereare diffuse infiltrates within the lungs.

26 CHAPTER 3

Pitfall

It may be difficult to distinguish apicalbullae and pneumothorax. Look at theshape of the superior border of thelung. If it is convex superiorly andremains convex at the lateral margin,this is characteristic of a pneumothorax.An apical bulla, where the superior wallof the bulla may be difficult to see, willcharacteristically result in a concaveshape of the superior margin of the lung.

If in doubt seek advice.

chioles, with destruction of the alveolarwalls, often as a result of smoking butalso seen as a result of a1-antitrypsin deficiency. This leads to inefficient gasexchange.

Imaging is indicated at first presenta-tion. It is only indicated for follow-up ifthere is a significant change in symptomsor signs.

CXR

Moderate to severe emphysema can bediagnosed but mild emphysema is oftenoverlooked, even by radiologists.• Large volume lungs (Fig. 3.8):

– Low flat diaphragm– Visibility of the anterior end of theseventh rib above the diaphragm– If a lateral CXR has been performedfor another reason, widening of thespace (>2.5cm) between the ascendingaorta and the sternum may be seen– Barrel-shaped chest.

• Bullae: thin-walled (<1mm) air spacesas a result of destruction of alveolar walls(not always associated with significantemphysema elsewhere in the lungs).• Reduced vascularity: found in areasmost severely affected and may only berecognized by a radiologist.

CT

Only indicated if reduction surgery ofbullae is being considered.

Chronic bronchitis

This is a clinical diagnosis based on thesymptoms of chronic cough withsputum production, dyspnoea andtypical lung function tests. There are no reliable radiographical features ofthis condition but it is associated with large volume lungs, scarring and intermittent consolidation in acute exacerbations.

Asthma

CXR is not indicated routinely forasthma. However, it is of value ifyou suspect that there may be a pneu-mothorax present. Asthma is one of themost common causes of spontaneouspneumothorax as a result of lungdisease.

Bronchiectasis

This is defined as localized irreversibledilatation of the bronchial tree. Thereare many causes of bronchiectasis, themore common ones are:• Infection (e.g. Staphylococcus, tuber-culosis, Klebsiella, fungal infections)• Congenital causes (e.g. a1-antitrypsindeficiency, cystic fibrosis, Kartagener’ssyndrome, Marfan’s syndrome)• Allergic bronchopulmonary asper-gillosis• Immunodeficiency states.However, in 40% of cases a cause is notidentified.

Symptoms include:


• Chronic, productive cough• Recurrent infection• Dyspnoea• Haemoptysis.

CXR

The changes may be subtle.• May appear normal.

Fig. 3.8 A patient with chronic obstructive airways disease and hyperinflatedlungs. The lungs appear hyperlucent, with the diaphragm flattened and eight ribscan be visualized anteriorly in the lung fields.

28 CHAPTER 3

• Bronchial dilatation may be seen aslarge rings or cyst-like spaces, whichmay or may not contain fluid levels.• Bronchial wall thickening may be seenas rings (wall thickness of a few millimetres) or tramlines (parallel wallsof bronchi with no tapering). Note thegroup of rings seen in the right mid zoneon the CXR in Fig. 3.9.

CT

CT is indicated in cases with a good clinical history of bronchiectasis with anapparently normal CXR. In cases with

abnormal CXR, CT is used if surgery isbeing contemplated, to demonstrate theextent of involvement.

Sarcoidosis

This is a common disease of unknownorigin but immunologically mediated,typified by non-caseating granuloma-tous lesions affecting many organs. Thoracic disease is present in 90% ofcases. The most common involvement islymph node involvement (43%). Lymphnode involvement and lung parenchy-

Fig. 3.9 A magnification view of the right mid zone demonstrates thick-walledring shadows typical of bronchiectasis. These ring densities are caused by thick-ened bronchi seen end on.


mal is seen in approximately 41%.Parenchymal disease alone occurs in approximately 16% of cases.

Presenting clinical features are:• Asymptomatic• Erythema nodosum, fever, malaise,joint pains• Unproductive cough and dyspnoeatend to occur with the more chronic

phase of lung involvement. Wheeze mayoccur in acute cases.

CXR

The most common finding in the acutephase is the presence of bilateral hilarlymph node enlargement (Fig. 3.10).Check the hilar regions carefully, as

Fig. 3.10 Mediastinal nodal (white arrow) and bilateral hilar nodal enlargement ina patient with sarcoidosis.

30 CHAPTER 3

small changes can easily be missed. Rightparatracheal nodal enlargement is notuncommon. Also:• Parenchymal disease may occur(43%), characteristically producingreticulonodular changes in the mid and lower zones, which may progress tofibrosis in the mid to upper zones.• Confluent changes similar to consoli-dation in the lungs.• Complete resolution of the earlyparenchymal changes occurs in one-third of cases; improvement occurs inanother 30%.• Fibrosis is irreversible.

Note:Miliary TB does not calcify

Note:Pleural effusions are rare (2%)Cavitation is rare (0.6%)

Common symptoms include:• Cough, haemoptysis• Shortness of breath• Weight loss• Night sweats.

CXR

Reactivated TB (post-primary TB) is themost common form. Features include:• Consolidation (80%), usually upperlobe or apical segment of lower lobe• Cavity formation (Fig. 3.11)• Soft-tissue stranding towards thehilum• Nodular pattern (20%)• May see pre-existing calcification incases of reactivation• Pleural effusion.

Primary TB is uncommon, but occursin patients from abroad and those withreduced immunity. CXR featuresinclude:• Consolidation (may be multiple sites)• Nodules of soft-tissue density• Hilar and/or mediastinal node enlargement• Pleural effusion.

Miliary TB may be primary or post-primary, and is characterized by finesoft-tissue nodules throughout lungs ofuniform size (2–3 mm) on the CXR.

CT

This may be useful in confirming paren-chymal changes and mediastinal lymphnode involvement. The parenchymalchanges on HRCT are reasonably specific.

Tuberculosis

Active infection with Mycobacterium tuberculosis is not common in fit peoplefrom countries with an immunizationprogramme, but do be aware of this pos-sibility in patients from abroad or thosewith reduced immunity. Atypical infec-tion is increasing in incidence.

If a patient has a productive coughand there is a high clinical suspicion oftuberculosis (TB), this informationshould be conveyed to the radiologicalstaff to allow appropriate managementin the department. This applies also topatients referred for follow-up filmswhile in the active stage.

Pleural effusions

Effusions may be:• Transudates, the most commoncauses are:

– Congestive cardiac failure– Hypoalbuminaemic states (e.g.nephrotic syndrome, cirrhosis).


Fig. 3.11 There is a thick-walled cavity (white arrow) seen within an area of tuber-culous consolidation in the right lower zone.

• Exudates, the most common causesare:

– Malignancy– Infection– Pulmonary emboli (often bloody)– Trauma (often bloody, may bechylous).

CXR

PA erect film changes are:• Blunting of the costophrenic angle• Meniscus effect in the pleural space• With large unilateral effusions, shift

of the mediastinum to the opposite sideof the chest• Collapse of the underlying lobe orlung• If loculation occurs as a result ofpleural tethering and thickening, lobular‘masses’ may be seen, which can be diffi-cult to differentiate from pleural de-posits or intrapulmonary masses. Alateral image may be helpful in differen-tiating the two conditions.Fluid may track into fissures where locu-lation may occur, giving rise to apparentintrapulmonary masses (Fig. 3.12).

32 CHAPTER 3

Subpulmonary effusion is a collectionof pleural fluid appearing to be trappedbetween the lung and the diaphragm.The result is that on a PA film the diaphragm appears flattened and elevatedbut the apparent dome of the diaphragmlies more laterally than normal. If the ef-

fusion is on the left, there will be widen-ing of the space between the ‘diaphragm’(top of the effusion) and the stomachbubble.

Always check the costophrenic angleson CXR as this is an area where pathol-ogy is easily overlooked.

Fig. 3.12 On a frontal chest radiograph, in a patient with cardiac failure, there isevidence of cardiomegaly with small bilateral basal pleural effusions and a largeapparent mass identified in the right lower zone. The upper margin of this is notwell defined. This represents encysted pleural fluid in the oblique fissure and thiscan be confirmed on a lateral view.


US

US is useful for confirming the presenceof an effusion, assessing its size andmarking the site of the effusion prior to aspiration. It is particularly usefulwhere the CXR fails in the recumbentpatient.

CT

CT is usually only performed as part oftrauma work-up or in cases of empyemato assess how thick the pleura hasbecome prior to possible surgical inter-vention. It is valuable in looking at theunderlying lung and mediastinum incases of suspected malignancy.

Both CT and US are used to direct theinsertion of needles and catheters intoloculated effusions.

Pneumothorax

Patients with a pneumothorax com-monly present with pleuritic chest pain,with or without shortness of breath.

Common causes

• Spontaneous:– Idiopathic (80%): caused by therupture of subpleural blebs in theapices, typically in tall thin young men– Secondary to underlying lung disease

(20%): the most common underlyinglung condition is COPD.

• Traumatic:– This may occur as a result of bluntor penetrating trauma– Iatrogenic causes include positivepressure ventilation, insertion of acentral venous line or pacemaker.

CXR

Standard inspiratory PA image

Look for a peripheral area where no lungmarkings are visible and try to identifythe lung border to assess the size of thepneumothorax.

In addition to the air in the pleuralspace, you may see varying degrees ofcollapse of the underlying lung, fromsmall subsegmental areas (often linear ortriangular) to collapse of the whole ofone or more lobes.

Expiratory image

If you have a high clinical suspicion of apneumothorax and cannot see one on thestandard inspiratory film, then an expi-ratory film may be helpful as the pneu-mothorax will be larger and the lung willappear more opaque than on the inspira-tory film, thus accentuating the differ-ence in density between the lung and thepneumothorax.

Pitfalls

• Differentiation from emphysema-tous bullae.• Skin folds may mimic the edge of alung but you will still be able to seelung markings peripheral to the fold.

Note:If the CXR is an AP film the patientmay have been supine, and fluid in thepleural space will gravitate to the pos-terior sulcus and be very difficult toidentify until large

34 CHAPTER 3

Tension pneumothorax

This is a medical emergency requiringrapid intervention, usually dramaticallyimproved by the insertion of a chest

Fig. 3.13 There is a large right-sided pneumothorax, which is under tension withmediastinal shift to the left. This occurred spontaneously.

drain. If there is no clinical doubt aboutthe diagnosis and the patient is criticallyill, it may be necessary to insert a chestdrain or needle prior to any imaging.

In cases of tension pneumothorax, air


passes into the pleural space on inspira-tion, but on expiration air is trapped inthe pleural space, usually as a result of aball valve effect. The result is the steadyincrease in the size of the pneumotho-rax. With each breath the diaphragm onthe affected side is flattened and the lungon the affected side collapses. Risingpressure causes shift of the mediastinumto the opposite side (Fig. 3.13). Thiseventually leads to ‘kinking’ of thetrachea and sudden obstruction that maybe fatal. Urgent action is required.

Acute pneumonia

Acute infection of the lung, as opposedto the bronchi, produces pneumonia inwhich exudate replaces air in the alveolileading to radiological sign of consolida-tion. However, most mild cases of pneu-monia are acquired in the communityand treated successfully by general prac-titioners without resorting to chest radi-ography. A CXR taken acutely in A&Ewhen the diagnosis is obvious is unnec-essary and may be misleading if per-formed before the exudate has formed. ACXR is very valuable in cases wherethere is clinical doubt or failure torecover satisfactorily.

The changes of pneumonia on CXRare:• Peripheral soft-tissue density shad-owing: consolidation (Fig. 3.14)• Air in branching bronchi and bronchioles within this shadowing: theair bronchogram (Fig. 3.14)• Pleural effusion.

Patterns of involvement may help topoint to certain organisms as the cause:• Lobar pneumonia involves the wholeor major part of a lobe:

– The lobe involved can usually be determined on a PA chest film aloneusing the silhouette sign– Typical organisms are Strepto-coccus pneumoniae, Klebsiella and Mycoplasma.

• Bronchopneumonia involves the largeairways as well as parts of the lung:

– Consolidation is patchy and an airbronchogram may not be present– There is also an interstitial elementto the changes that may be evident on a CXR. This pattern may shownodularity or ring shadows– Typical organisms are Staphylococcus,Streptococcus, Gram-negative infections– In immunocompromised patients,consider also fungi, Legionella and Aspergillus.

• Extensive bilateral pneumonia isunusual and should alert you to:

– Viral infections or Legionella– In immunocompromised patients,consider pneumocystis, fungi and tuberculosis.

Lung abscess

This is one of the possible complicationsof infection and may arise de novo or as a

Note:Pneumonia may be the result of a

lesion causing narrowing of a proxi-mal bronchus. Depending on age andcircumstances, the most commoncauses are carcinoma and foreign body.

Any transudate or exudate (e.g.blood, pulmonary oedema) in thealveoli will have exactly the same ap-pearance on CXR (consolidation).

36 CHAPTER 3

complication of pneumonic consolida-tions. If arising from an area of pneu-monia, look for an air-filled cavity orfluid level in the area of consolidation. Ifarising de novo, it may appear as a ‘masslesion’. Again, look carefully for air orfluid level within the mass.

These changes may represent a gas-

forming organism or suggest a bronchialconnection. A direct specimen for mi-crobiology (under CT guidance) is oftenhelpful if blood cultures are negative.

Remember that cavitation is also seenin other conditions (e.g. malignancy,both primary and secondary, pulmonaryemboli and rheumatoid nodules).

Fig. 3.14 In this case of Streptococcus pneumoniae infection there is extensive leftupper lobe consolidation with some patchy consolidation also in the right midzone. Note the prominent air bronchogram seen in the consolidated left upperlobe (black arrows), which is a result of normal bronchus being outlined by con-solidated lung.


Asbestos-related lung disease

Inhalation of asbestos fibres, particularlyamosite (brown asbestos) and crocidolite(blue–black asbestos) is an industrialhazard that can lead to chest disease. Patients may be entitled to compensation.

Disease categories

Benign pleural disease

Pleural effusions may develop after a

latent period averaging 10 years after exposure. Pleural plaques and pleuralcalcification occur typically on the diaphragm or posterolaterally on the PA films. They are often asymptomatic(Fig. 3.15).

Malignant mesothelioma

This can develop in the pleura, usuallyunilaterally. Five to 10% of asbestosworkers develop malignant mesothe-lioma. It has a latent period of 20–45years. The most common presenting

Fig. 3.15 This patient has widespread pleural calcifications secondary to previousasbestos exposure.

38 CHAPTER 3

symptom is chest pain, which is usuallynon-pleuritic. Diffuse progressive thick-ening of the pleura on one side is shownon CXR or CT. Evidence of chest wallinvasion (rib destruction or soft-tissuemass in chest wall) may be the onlyfeature differentiating mesotheliomafrom benign disease on CXR or CT.

Asbestosis

This is the term for the interstitial fibro-

sis that develops in approximately 50%of patients with industrial asbestos exposure.

Interstitial change is best shown byHRCT and is an important factor incompensation assessment.

Interstitial fibrosis

Patients with interstitial fibrosis com-monly present with dyspnoea, a dry

Fig. 3.16 This patient has interstitial lung fibrosis. There is diffuse reticular densityin both lower zones with associated volume loss. The left heart border is ill-definedwith a ‘shaggy’ appearance.


cough and restrictive pulmonary func-tion tests. Causes include the following:• Idiopathic• It may be associated with other systemic conditions such as collagen vascular diseases, especially sclerodermaand rheumatoid arthritis• Asbestosis• Sarcoidosis: fibrosis tends to occur inupper zones• Chronic hypersensitivity pneumoni-tis: fibrosis tends to occur in upper zones• Drug-induced fibrosis.

CXR (Fig. 3.16)

CXR may be normal in early disease(2–8%). Characteristic features includeirregular lines giving a reticular pattern,progressing to characteristic basal peripheral ring shadowing (honeycomblung). Septal lines and decreased lungvolume may occur. A ‘shaggy’ heartborder as a result of reticulation or ring

shadows in the adjacent lung may beseen.

CT

HRCT is far more sensitive than theCXR for demonstrating interstitial fibrosis. The characteristic features onHRCT are peripheral ring shadows, sub-pleural lines, traction bronchiectasis anda ‘ground glass’ appearance. If there is‘ground glass’ density that does notcontain areas of bronchiectasis, then thechanges may be reversed by steroidtherapy. Linear changes suggest irre-versible fibrosis.

Further reading

Armstong P, Wilson A, Dee P, HansellDM, eds. Imaging of Diseases of theChest. London: Harcourt, 2000.

This chapter covers:Common conditions• Cardiac failure• Pulmonary embolism• Deep venous thrombosis• Aortic disease (including thoracicdissection, aneurysm rupture)• Peripheral vascular disease• Pericardial effusion, superior venacava obstructionCommon presentations in whichimaging can help• Acute chest pain: cardiac is-chaemia, pulmonary embolism,aortic dissection• Acute shortness of breath: cardiacfailure, pulmonary oedema• Chronic chest pain: cardiac is-chaemia, pericardial effusion

Imaging strategy

The CXR remains the mainstay of initialimaging assessment of these acute symptoms and can provide important diagnostic information:• Cardiac silhouette and size• Mediastinal/hilar contour• Lungs for evidence of interstitial orair-space oedema in particular• Pleural spaces: are pleural effusionspresent?

However, the amount of informationthat can be gleaned from a CXR in theacute situation may be limited. Elderlyor confused patients may not be able tocooperate, resulting in rotated or poorly

exposed radiographs. In acutely ill pa-tients, radiographs need to be taken APrather than PA. In AP films, the cassetteis often wedged behind the patient, whois propped up in bed, and this means thatthe heart is some distance from the film,causing relative enlargement of the car-diac silhouette because of magnification.Therefore heart size cannot be reliablyassessed on an AP film.

An estimate of heart size can be madeon PA films — the cardiothoracic ratio(CTR). This represents transverse mea-surement of the heart at its widest pointdivided by the thoracic width at itswidest point (measured from the innerrib margin, and should be < 50% inadults).

Once a patient has been assessed andan initial working diagnosis formulated,further imaging is often required:• US: arterial or venous colour Dopplerultrasound• CT/CT angiography• MR/MRA• Conventional peripheral angiography• NM.These modalities are available in mostradiology departments and can be accessed following discussion with a radiologist.

Most radiology departments will haveprotocols for investigation of certainconditions (e.g. pulmonary embolism)and it is useful to be aware of these. Askfor advice if you are not sure.

Certain cardiac investigations (e.g.echocardiography and cardiac angiogra-

Chapter 4: Cardiovascular system

40

CARDIOVASCULAR SYSTEM 41

phy) are now routinely performed bycardiologists and are not covered in thischapter.

Cardiac failure

Cardiac failure commonly presents

acutely, often in association with myo-cardial infarction, or as acute decompensation of chronic cardiac impairment, perhaps precipitated bysepsis (e.g. chest infection), particularlyin the elderly.

Fig. 4.1 CXR in a patient with cardiac failure. The heart is enlarged and there is evidence of widespread interstitial oedma with septal lines present. Septal linesare caused by interstitial oedema in interlobular lymphatics and are best seen ashorizontal subpleural lines at the lung bases.

42 CHAPTER 4

CXR

The CXR is the mainstay of initial as-sessment. Look for:• Cardiac enlargement (however, manyfilms AP)• Pleural effusion• Pulmonary oedema. This may be interstitial (Fig. 4.1 — look for septallines, these are caused by interstitialoedema in the interlobular lymphatics)and fluid may spill over into the alveolar

air spaces to cause more confluent opaci-fication (Fig. 4.2).

In pulmonary oedema, changes maybe apparent on the CXR before thepatient has symptoms, and converselyCXR abnormalities may persist when thepatient is clinically well. Pulmonaryoedema may be cardiogenic or non-cardiogenic (e.g. fluid overload, neardrowning, smoke inhalation, fat em-bolism). In non-cardiogenic causes, theheart size may be normal (Fig. 4.2). Re-

Fig. 4.2 CXR demonstrating diffuse alveolar (air-space) oedema in a young patientfollowing intravenous fluid overload. The patient is intubated with a Swan–Ganzcatheter and monitor leads are present.


member also that pulmonary oedema canappear unilateral on CXR if the patienthas been lying on one side for some timeprior to the radiograph being taken.

Pulmonary embolism

Pulmonary embolism (PE) represents a significant cause of mortality, particu-larly in the postoperative period (7–10days post-procedure is the time ofhighest risk).

Patients present with shortness ofbreath, pleuritic chest pain and haemo-ptysis. Thrombus tends to originatewithin the deep veins of the lower limb,breaks off and embolizes to the lung.Pelvic veins are another common sourceof thrombus.

There is a wide spectrum of disease,ranging from recurrent small emboliover a prolonged period, which mayresult in pulmonary hypertension, tosudden death from massive embolism.

Most departments will have a protocolfor imaging in acute PE.

CXR

• Frequently normal• Atelectasis and/or consolidation mayoccur• Arterial widening at the hilum result-ing from embolus may be visible.

Lung scintigraphy (V/Q scan)

Involves performance of a ventilationand then a perfusion study with adminis-tration of inhaled and intravenously in-jected isotope (often 99mTc-based).

Examinations are reported as low,medium or high probability of PE, ac-

cording to set criteria including CXRfindings (Fig. 4.3a,b).

However, V/Q accuracy is reduced inseveral conditions (e.g. acute asthma,chronic obstructive airways disease orlung fibrosis) or where there is signifi-cant abnormality on the CXR with vas-cular redistribution.

Remember also that in many depart-ments there is no routine NM service outof hours and also that isotope may needto be ordered from an off-site source.

CT

CT pulmonary angiography is a highlyaccurate technique that is being increas-ingly used to investigate suspected PE(Fig. 4.4). It can supplement intermedi-ate probability V/Q scans if there is clinical concern and is helpful in thosepatients with abnormal CXRs whereV/Q accuracy will be reduced.

Pulmonary angiography

With the advent of CT pulmonary an-giography this technique is now usedmuch less. It may still be helpful in diffi-cult cases and also can be used to deliverthrombolysis directly into clot in pa-tients with acute massive PE.

Colour Doppler US

This may be used to assess the lowerlimb leg veins in patients with suspectedPE occult to imaging. Pelvic vein throm-bus is often difficult to identify.

Lower limb deep venous thrombosis

Patients present with:

Fig. 4.3 (a) Normal ventilation study of the lungs in a patient with suspected pul-monary embolism. (b) Perfusion study in the same patient demonstrates multipledefects (areas of mismatch) consistent with emboli (arrows).

a

b


• Pain• Swelling• Positive Homan’s sign (calf pain withfoot dorsiflexion).However, clinical examination is notori-ously unreliable.

Risk factors for deep venous thrombo-sis (DVT) include:• Surgery, especially on legs or pelvis• Prolonged immobilization• Malignancy• Obesity• Pregnancy or oral contraceptive pill.

Calf vein thrombus may propagate toinvolve the popliteal and/or femoral

veins and it is at this stage that there is increased risk of PE.

Radiology departments will havemanagement algorithms for the inves-tigation of suspected lower limb DVT,following clinical DVT risk assessment.

US

US represents the initial imaging modal-ity of choice.

Venous US is combined with D-dimerestimation in some centres. D-dimer isproduced by the action of plasma oncross-linked fibrin and raised levels

Fig. 4.4 Axial post-contrast CT demonstrates thrombus as low attenuation fillingdefect within enhancing right (black arrow) and left (white arrow) pulmonary arteries.

46 CHAPTER 4

may be found in venous thrombo-embolic disorders. D-dimer can be used in combination with clinical assessment to establish which patientsneed imaging. Check protocols whereyou work.

The main sonographic features ofvenous thrombosis include identifica-tion of luminal thrombus, inability tocompress the vein because of presence ofthrombus, and absent or altered colourflow within the veins (Figs 4.5 & 4.6).

Fig. 4.5 Colour Doppler US of normal popliteal vein (V) and artery (A) behind theknee. Note normal flow in both vessels.


US is accurate at demonstrating thedeep veins in most patients but does haveareas of weakness:• Patients with fat or oedematous legs,or with extensive bandaging

• The vein can be difficult to visualize atthe level of the adductor canal• In patients who have had pre-vious DVT, with subsequent venous deformity or scarring.

Fig. 4.6 Colour Doppler US in the same patient as Fig. 4.5 demonstrating poplitealthrombus (large white arrows) in the popliteal vein, with some colour flow seen inthe vein above this (small white arrows).

48 CHAPTER 4

Usually, deep veins can be visualizeddown to the knee and one option that canbe used if calf veins are initially poorlyseen is to repeat the US at 7–10 days, ifthere is persisting clinical concern, tolook for propagating thrombus.

Contrast X-ray venography

This is now little used because of the following:• Invasive (needle in foot vein)• Injection of iodinated contrast• Use of ionizing radiation.

It has been largely replaced by US, butdoes have a role in technically difficultcases and post-phlebitic limbs.

Thoracic aortic dissection

Aortic dissection is caused by spontan-eous separation of the aortic intima andadventitia by circulating blood havinggained access to the media of the aorticwall, usually secondary to an intimal tear.Patients present with a sharp, tearingchest pain, often radiating to betweenthe scapulae, and a heart murmur (fromaortic regurgitation), asymmetric orabsent peripheral pulses; shock orpleural effusion may also be present.

Hypertension is the most commoncause, with Marfan’s syndrome the othermain aetiology.

CXR

CXR is usually performed initially andcan be helpful. Mediastinal wideningand cardiac enlargement (haemoperi-cardium) may be present, but these areasare often difficult to assess on AP films.Further imaging should be arranged

following discussion with radiologistsand cardiologists. A combination of CTand echocardiography is often used initially.

CT

CT is accurate, as long as patients arestable and able to cooperate with breath-holding, in the identification of anintimal flap (Fig. 4.7) separating the twoaortic channels (the true and falselumens) and also dissection extent.

The Stanford classification is easiestto remember:• Type A: dissection involves ascendingaorta with or without arch and needs sur-gical repair.• Type B: dissection involves descend-ing aorta distal to the left subclavianartery and may respond to medical treat-ment only.

CT may be degraded by streak arte-facts from cardiac motion.

Transoesophagealechocardiography

This is a highly accurate adjunct for assessment of the ascending aorta.

MRI

This is used in some centres but is notwidely available and problems can arisewith patient monitoring during the procedure.

Aortography

This is accurate but invasive and may beperformed following referral to a cardio-thoracic centre. In medically unfit pa-tients, some centres use covered stents


deployed within the thoracic aortic truelumen to occlude the intimal tear andfalse lumen.

Abdominal aortic aneurysm

These are most commonly atheroscle-rotic in origin and are usually infrarenal,with iliac artery extension common.

Aneurysms may be asymptomatic anddetected during routine clinical exam-ination or during ultrasound exam-ination of the abdomen. Patients with

aneurysms may present with an ab-dominal mass or with pain. Patients with aneurysm leak or rupture present with pain, often radiating to the back with hypotension and an often palpable and tender mass.

The risk of aneurysm leak or ruptureincreases with increasing aneurysm size.Ruptured aortic aneurysm has a highmortality. Aortic size > 3 cm on ultra-sound represents aneurysmal dilatation.Aneurysms > 5 cm in diameter should beconsidered for surgical repair, althoughin some centres aneurysms may be con-

Fig. 4.7 Axial post-contrast CT in a patient with a type A thoracic aortic dissection.Intimal flaps are seen within the ascending (single small black arrow) and de-scending (paired small black arrows) thoracic aorta. Note normal pulmonary arterytrunk (large black arrow) and a pleural effusion is present on the left (small whitearrow).

50 CHAPTER 4

sidered for stent grafting, especially inmedically unfit patients.

If you have any suspicion that you aredealing with a leaking aneurysm, contactsenior surgical and anaesthetic col-leagues urgently.

Haemodynamically unstable patientsneed to be transferred to theatre. If pa-tients are stable, or if the diagnosis is indoubt, imaging may be indicated.

AXR

This is often performed as part of ab-dominal pain assessment. Calcificationin an aneurysmal aorta may be apparent.If there has been retroperitoneal haem-orrhage, a mass may be present with en-largement or loss of psoas outline.

US

US can be useful for identification of ananeurysm, but access to the retroperi-toneum is often limited.

CT

CT is the modality of choice for the diag-nosis of suspected aneurysm leak in stablepatients (Fig. 4.8) and also for aneurysmassessment prior to surgery in electiveaneurysm repairs. CT will demonstrateaneurysm extent and its relation to therenal and common iliac arteries.

Peripheral vascular disease

There are a number of modalities nowavailable for evaluation of the lower limbarterial supply in patients presentingwith symptoms of claudication, rest painor acute ischaemia.

Colour Doppler US and MRA repre-sent non-invasive and accurate means ofmapping out the arterial supply of thelower limbs in patients with chronicsymptoms.

Conventional X-ray angiography maybe performed in patients with suspectedstenoses identified with US or MRAprior to therapeutic intervention or inpatients with acute ischaemia, perhapssecondary to an embolus.

Angiography is usually performed via a femoral artery puncture, with acatheter introduced into the lower ab-dominal aorta and contrast injected. Ifa stenosis or occlusion is identified, thismay be treated via angioplasty (balloondilatation) or insertion of a metallic stent(Figs 4.9 & 4.10).

Patient preparation for angiography

• Consent: this may be obtained by asenior surgical colleague or radiologist.Check the protocol.• IV cannula insertion.• Check full blood count and clottingprofile.• Bleeding diathesis is a contraindica-tion and you always need to inform theradiologist if the patient is taking warfarin.• If the patient is on metformin, thisshould be stopped the day before theprocedure.• The patient should be fasted for 4 hrbefore the procedure.

Complications of angiography

At puncture site:• Thrombosis or occlusion• Haematoma


• Pseudoaneurysm• Infection• Nerve damage• Arteriovenous fistula.

Patients with acute limb ischaemiawith occluding thrombus demonstratedangiographically may be suitable forthrombolysis. Using this technique, acatheter is manipulated near to thethrombus and a thrombolytic agentinfused directly (e.g. recombinant tissueplasminogen activator; rtPA).

There are several contraindications tothe use of thrombolysis:• Active internal bleeding• Recent cerebrovascular accident(within 6 months) including transient ischaemic attack (TIA) (within 2months)• Intracranial tumour• Recent major surgery, organ biopsy ortrauma• Uncontrolled hypertension• Known active peptic ulceration

Fig. 4.8 Axial post-contrast CT in a patient with a leaking aortic aneurysm. Theaorta is aneurysmal (large white arrow) and there is extensive retroperitonealhaemorrhage on the left (black arrow). Note normal right psoas muscle (smallwhite arrow).

52 CHAPTER 4

Fig. 4.9 Image from a femoral angiogram in a patient with an absent left femoralpulse and left leg pain. The catheter has been passed up the right femoral arteryand over the aortic bifurcation (large white arrow) and contrast injected. Thisdemonstrates occlusion of the left external iliac artery (black arrow) with somecontrast in the left internal iliac artery, which also appears occluded soon after itsorigin (small white arrow).


Fig. 4.10 Image from the same patient as Fig. 4.9, demonstrating a metallic stentdeployed over a catheter traversing the external iliac occlusion (white arrows) withcontrast passing distally (black arrow), confirming vessel patency.

54 CHAPTER 4

• Proliferative diabetic retinopathy orhistory of vitreous haemorrhage.

Patients must be carefully monitoredduring thrombolytic administration for evidence of haemorrhage and repeat angiography will be required to demonstrate vessel patency. Keep in close contact with the radiologist involved.

Pericardial effusion

Pericardial effusion may occur in:• Cardiac or renal failure• Post-trauma• Post-myocardial infarction or aorticdissection• Post-infective (e.g. viral, TB).

Fig. 4.11 CXR in a patient with tuberculous pericardial effusion. The heart is en-larged and lucency is well demonstrated (between arrows) at the left heart border,resulting from pericardial fluid.


CXR

This represents the usual initial imagingmodality. Look for:• Globally enlarged cardiac silhouette• Rapidly appearing cardiomegaly onserial CXRs, with normal pulmonaryvascularity• An increase in lucency at the heartmargin, brought about by difference indensity of the heart muscle and adjacentpericardial fluid (Fig. 4.11).

Echocardiography

This will confirm the presence of effu-

sion and can be used to guide therapeuticor diagnostic aspiration.

Superior vena cavasyndrome

This is caused by superior vena cava obstruction (SVCO) with develop-ment of collateral pathways and isusually secondary to compression viamediastinal bronchial carcinoma or lymphoma.

Patients present with head or neckoedema, headaches and cutaneousvenous collateral channels.

Fig. 4.12 Post-contrast CT in a patient with superior vena cava (SVC) obstructioncaused by squamous cell lung carcinoma. A large mass is present (white arrow)markedly compressing the SVC (black arrow).

56 CHAPTER 4

CXR

This may demonstrate a mediastinalmass. Look for evidence of mediastinaladenopathy, bony and lung metastases.

CT

CT is the next investigation of choice. Itwill delineate the superior vena cava(SVC) with the level of compression anddemonstrate a mediastinal mass (Fig.4.12). Metastases to bone, lungs and livercan also be demonstrated, together withSVC thrombus.

SVC venography

This may be useful in some cases. It is

performed following injection of con-trast into an arm vein and delineates thelevel and extent of compression and the presence of associated or causativethrombus. Some patients may be suit-able for insertion of an SVC stent acrossa stricture for palliative purposes torelieve obstruction.

Further reading

Hagspiel KD, Matsumoto AH, eds. Radiologic Clinics of North America:Vascular Imaging; 2002; Volume 40(4).

This chapter covers:Common conditions• Oesophagus: carcinoma, oe-sophagitis and peptic stricture,achalasia• Stomach: carcinoma• Small bowel: obstruction, pneu-moperitoneum, Crohn’s disease,malabsorption• Also, leiomyoma, gastric volvu-lus, gastric dilatationCommon presentations in whichimaging can help• Dysphagia: peptic stricture, car-cinoma of oesophagus or stomach,oesophagitis• Haematemesis: ulceration, car-cinoma, varices• Dyspepsia: ulceration, gastritis• Acute abdominal pain: obstruc-tion, pancreatitis, perforation• Weight loss or anaemia with anyof the above: particularly carcin-oma, ulceration• Many symptoms relating to theupper gastrointestinal tract are now investigated primarily with en-doscopy, with barium studies re-served for patients who are unfit orwho decline endoscopy

Imaging strategy

Endoscopy

Endoscopy is the main investigation forabnormalities of the upper gastrointesti-

nal (GI) tract, although barium studiesare useful in those patients who are unfitor decline endoscopy. Endoscopy has thebenefit of easy biopsy of any lesionsseen.

Barium examination

This remains the initial modality ofchoice for dysphagia in many centres andis also the primary investigation for sus-pected small bowel pathology.

Identifying the most likely site ofpathology in the request is important(e.g. oesophagus, stomach or smallbowel), so that the patient can be pre-pared for a barium swallow, meal or smallbowel follow-through. In addition, itguides the radiologist to select the bestbarium preparation. Different bariumsuspensions are used for each area tomaximize coating and diagnostic accuracy.

If a small bowel enema is required it is often helpful to discuss this with a radiologist as there are different ways ofconducting the examination that requireparticular preparation of the patient.

For patients with suspected acute per-foration or bowel obstruction, a supineAXR and erect CXR should be re-quested. Other things to look for on theCXR are metastases in oesophageal orgastric carcinoma, or aspiration pneu-monia and oesophageal dilatation inachalasia and carcinoma.

Chapter 5: The upper gastrointestinal tract

57

58 CHAPTER 5

CT

CT is the technique of choice for stagingupper gastrointestinal tract malignancyand is being increasingly used.

MR, US and NM

These do not have prominent roles inprimary investigation of upper gastroin-testinal tract disease. Interventional ra-diology does have techniques to offer in palliative treatment of mechanical obstruction.

Oesophageal carcinoma

The majority of oesophageal carcin-omas are squamous cell in origin, al-though adenocarcinoma arising withincolumnar-lined epithelium (Barrett’soesophagus) is an increasingly re-cognized subgroup.

Most patients with oesophageal car-cinoma present with dysphagia, andbarium swallow is frequently performedas the initial imaging investigation.

Barium swallow

Early carcinomas appear as small sessilepolyps or plaques. Some lesions appearas superficial spreading lesions, givingirregularity and nodularity of themucosa (Fig. 5.1).

Advanced carcinomas appear as large,polypoidal, often ulcerating lesions andhave features of luminal stricturing withshouldering and an ‘apple core’ appear-ance (Fig. 5.2).

Patients with suspected oesophagealcarcinoma on barium examination willproceed to endoscopy for histological

confirmation and will undergo furtherimaging if they are considered suitablefor further treatment.

CXR

Many patients have a CXR at the time ofinitial barium examination and a dilatedoesophagus may be apparent occasion-ally. Also look for evidence of aspiration,pneumonia and lung and rib metastases.

CT

This is currently the best, relatively non-invasive test for staging oesophagealcarcinoma and identifying features ofinoperability which include:• Invasion of local structures (e.g. aorta,pericardium, diaphragm)• Associated adenopathy• Metastases to lung or liver.

MR

This is currently less accurate than CT.

Endoscopic US

This is accurate and complementary toCT in assessing local extent of tumourand local nodal status.

PET

A major problem for CT is detectingtumour in normal-sized nodes (nodalenlargement is the main CT criterion formalignancy). PET has been shown to beeffective at detecting nodal metastasesoccult on CT.

UPPER GASTROINTESTINAL TRACT 59

Fig. 5.1 Film from barium swallowdemonstrates a superficial spreadingoesophageal carcinoma (arrows). Notenodularity and irregularity of mucosa.

Fig. 5.2 Advanced oesophageal car-cinoma on barium swallow. There is alarge polypoidal mass with stricturing,mucosal irregularity and ulceration.

60 CHAPTER 5

Palliative treatment

Many patients turn out to be inoperableor unfit for radical surgery. Dysphagia isfrequently a problem and can be pal-liated with radiological insertion of ametallic stent over a guidewire to crossand then dilate the tumour.

Oesophagitis

Reflux oesophagitis and peptic stricture

Most patients who present with symp-toms of gastro-oesophageal reflux andreflux oesophagitis will undergo endo-scopic assessment if conventional drugtreatments fail.

Persistent reflux oesophagitis may initiate the development of a pepticstricture, usually manifested by slowlyprogressive dysphagia. Barium studiesare useful for initial assessment in suchpatients.

Most peptic strictures are in the distaloesophagus and they appear smooth andtapered on barium examination (Fig.5.3). These lesions should always be as-sessed endoscopically to exclude malig-nancy and can be considered for balloondilatation.

Infective oesophagitis

Candidiasis is the most common cause ofinfective oesophagitis, although herpessimplex and cytomegalovirus may alsobe responsible. Candida infection usuallyoccurs in the immunocompromised

patient and spreads down from themouth.

Patients often present with severe andpainful dysphagia, and barium swallowis used to confirm the diagnosis.

Candida oesophagitis appears as dis-crete plaque-like lesions that are mucosaland occur in the upper and mid-oesophagus (Fig. 5.4). Plaques may coalesce to give a ‘shaggy’ appearance.

Achalasia of the oesophagus

Achalasia is caused by a failure of normalperistalsis and relaxation at the level ofthe lower oesophageal sphincter. Thecause is unknown but it may be neuro-genic in origin. Patients tend to bemiddle-aged and present with slowlyprogressive dysphagia. Regurgitation of food contents and aspiration mayoccur.

There is an increased risk of oeso-phageal carcinoma in achalasia.

Request barium swallow and CXRinitially. Barium swallow demonstratesoesophageal dilatation, which may bemassive and contain significant foodresidue. Normal peristalsis is absent and typically the lower oesophagus has a narrowed ‘beak-like’ appearance (Fig. 5.5).

The dilated oesophagus may be visibleon CXR, often in the right paratrachealregion and the normal stomach bubble isabsent. An air–fluid level may be seen ashigh as the manubrium.

Endoscopy should also be performedto exclude malignancy (food residue canmake this difficult).


Fig. 5.3 Peptic-type stricture in the upper thoracic oesophagus demonstrated on barium swallow. Note tapered appearance and smooth margins. The upper oesophagus is dilated (arrow).

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Fig. 5.4 Barium swallow demonstration of candidiasis in the oesophagus. Multiplemucosal plaques are present. Oral Candida is usually present, allowing correct diagnosis, and the disease responds promptly to antifungal treatment.


Fig. 5.5 (a,b) Two films from a barium swallow series in a patient with achalasia.There is gross dilatation of the oesophagus, which contains food residue andsmooth narrowing of the lumen is seen in the distal oesophagus (arrows in b).

a b

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Gastric carcinoma

Patients present with vague symptoms,including epigastric discomfort, anorex-ia and weight loss. Most gastric carcino-mas are adenocarcinomas and tend to beadvanced at the time of diagnosis. Prog-nosis is poor.

AXR

AXR may show gastric mass or cal-cification in tumour or metastases. Cal-cification is rare, but may occur inmucin-producing scirrhous carcinomas.

Gastric outflow obstruction may beevident with antral tumours.

CXR

Look for lung metastases and pleural effusion.

Barium meal

This used to be the mainstay ofdiagnosis of gastric carcinoma but hasbeen largely replaced by endoscopy.Barium meal may still be useful in somecircumstances:• Scirrhous carcinoma may extend

Fig. 5.6 Film from barium meal examination in a patient with gastric carcinomaand ‘leather-bottle’ gastric configuration. Note diffuse narrowing of stomachbody (arrows).


extensively and submucosally in thestomach giving a ‘leather-bottle’ ap-pearance (Fig. 5.6). Occasionally, thestomach mucosa may look normal endoscopically and deeper biopsies arerequired.• Barium can be used to assess theextent of a gastric carcinoma if palliativeinsertion of expanding metallic stents isbeing considered.

CT

CT is the imaging modality of choice forstaging gastric carcinoma (Fig. 5.7). CTwill:

• Demonstrate a gastric mass or wallthickening• Confirm stage of tumour and oper-ability by demonstrating:

– Invasion of local structures– Metastases along peritoneal liga-ments with mesenteric nodal involve-ment and ascites– Involvement of regional lymphnodes– Liver, lung and ovarian metastases.

Endoscopic US

This can be used as a complementarymodality to CT for assessing tumour ex-

Fig. 5.7 Post-contrast CT in a patient with locally advanced gastric carcinoma.There is diffuse thickening of the stomach wall (long arrows) and bulky left gastricand coeliac adenopathy is present (short arrow).

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tension into the gastric wall and involve-ment of local lymph nodes.

Leiomyoma

More than 50% of all benign oeso-phageal tumours are leiomyomas, whichcomprise encapsulated bands of smoothmuscle and fibrous tissue.

Gastric leiomyoma is the second mostcommon benign stomach tumour andleiomyomas also are common in the

small bowel. Gastric leiomyoma appearsas a submucosal mass on barium exam-ination and CT and may ulcerate.

Oesophageal leiomyoma is oftenasymptomatic, although patients maypresent with dysphagia or haemateme-sis. Masses can be seen on CXR when large calcification is a feature.These tumours appear as smooth sub-mucosal lesions on barium swallow (Fig. 5.8).

Leiomyomas are at risk of malignantsarcomatous degeneration.


Fig. 5.8 Barium swallow examination demonstrates a large leiomyoma in thelower oesophagus (arrow).

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Gastric volvulus

This is an uncommon acquired twist of the stomach that may cause outflowobstruction. It is caused by abnormalstomach suspensory ligaments and oftenelongated gastrocolic and gastrohepaticmesenteries allowing stomach rotation.

A diaphragmatic defect (e.g. hernia oreventration) is often also present.

In organo-axial volvulus, the stomachrotates upward around a line extendingfrom cardia to pylorus (long axis) (Fig.5.9). In mesentero-axial volvulus, thestomach rotates around a line from lesserto greater curvature.

Patients present with pain, inability to

Fig. 5.9 Barium meal examination demonstrates organo-axial volvulus of thestomach with the stomach intrathoracic and greater curve (long arrows) above thelesser curve. Note tip of nasogastric tube (short arrow).


vomit and there is also difficulty passinga nasogastric tube or barium into thestomach.

An erect CXR may demonstrate anair–fluid level in the chest. Bariumstudies may show stomach inversionwith greater curve above the lesser curve (Fig. 5.9).

Complications include gastric outflowobstruction, with dilatation and perforation.

Gastric dilatation

Gastric dilatation with outflow obstruction

Peptic ulcer disease is the most commoncause. Other important causes includecarcinoma of the stomach or duodenalinvasion by pancreatic carcinoma.

AXR

AXR demonstrates the outline of adilated gas-filled stomach that maycontain food residue. Look for air in thestomach wall secondary to ischaemia.

Patients often proceed to a bariumstudy in the first instance, where a causemay be identified (Fig. 5.10). Alterna-tively, a nasogastric tube can be passedand the stomach emptied and then endoscopy attempted.

Gastric dilatation withoutoutflow obstruction

Acute gastric retention can occurwithout mechanical obstruction, but thisneeds to be excluded.

Acute gastric dilatation can occurpostoperatively and in other medical

conditions (e.g. diabetes) and is charac-terized by acute severe distension of thestomach with gas and fluid. Vomitingand circulatory collapse may follow if di-agnosis and treatment (nasogastric tube,correct electrolytes, rehydrate) is notprompt.

Small bowel obstruction

Adhesions following previous surgeryare the most common cause of smallbowel obstruction. Obstructed hernia,gallstone ileus, small bowel volvulus,tumour and stricture (e.g. Crohn’sdisease) should also be considered. Thediagnosis of small bowel obstruction canusually be made following clinical exam-ination and AXR. Patients present withpain, vomiting and constipation. On ex-amination, high-pitched tinkling soundsare typical of a mechanical obstruction.Although the AXR findings in obstruc-tion and ileus are similar, bowel soundstend to be diminished in ileus.

AXR

Generally, AXR is performed supine andin small bowel obstruction will demon-strate multiple dilated loops of gas-filledsmall bowel. Small bowel tends to be cen-trally located in the abdomen. Valvulaeconniventes are thin mucosal lines thattraverse the whole bowel lumen, seenbest in the proximal small bowel.

Sometimes, when dilated, small bowelloops are fluid-filled and it may be hardto identify these. Here an erect AXR maybe helpful by demonstrating air–fluidlevels in small bowel. Dilated smallbowel loops may have a ‘stepladder’ ap-pearance (Fig. 5.11) in low obstruction

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Fig. 5.10 Film from a barium meal examination at a delay with small bowel opaci-fication also. There is stomach distension, with food residue seen in the stomach.Luminal narrowing and mucosal irregularity in the second part of the duodenumsecondary to pancreatic malignancy (arrow) is responsible. Obstruction is not com-plete. Note barium reflux into biliary tree secondary to previous sphincterotomy.


(the greater the number of loops thelower the obstruction). Look for:• Air in biliary tree and impacted gall-stone in the distal ileum in gallstone ileus

• Air in obstructed femoral or inguinalhernia sac• Evidence of perforation• Sacroiliitis (Crohn’s disease).

Fig. 5.11 Supine AXR in a patient with small bowel obstruction secondary to adhe-sions. The dilated small bowel loops are arranged in a ‘stepladder’ configuration.Note valvulae conniventes traversing bowel lumen.

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If there is no history of previoussurgery and patients do not settle withconservative treatment, further imagingcan be considered prior to laparotomy.

Barium follow-through or smallbowel enema

Technically, results are often poor withdilution of barium and flocculation in obstructed bowel. If obstruction re-solves, barium studies can then be per-formed electively and are often helpful.

US

This can differentiate small from largebowel but is rarely diagnostic of thecause of obstruction.

CT

This is often very useful in diagnosingthe cause of small bowel obstruction andalso in assessing small bowel ischaemia.No oral contrast is needed and extra-mural information is also acquired.

Pneumoperitoneum

There are a large number of causes offree air within the peritoneal cavity, butthe cause most commonly seen as anemergency is that from a perforatedviscus (e.g. gastric or duodenal ulcer, appendix, diverticulum, caecal volvulusor toxic megacolon). Iatrogenic causesshould also be recognized (e.g. leakingsurgical anastomosis, post-laparoscopy[air not normally seen after 3 days], en-doscopic perforation). Post-laparotomyair can persist ‘normally’ for up to 10days.

Suspected perforation of a viscus isusually imaged initially with a supineAXR and an erect CXR (allowing freeintraperitoneal air to rise under the dia-phragm). If there is persisting clinicalconcern and initial films are unhelpful, aleft lateral decubitus radiograph may bediagnostic. The patient lies on the leftside for 10–15 minutes and a horizontalbeam radiograph is taken. As little as 1 ml of free air can be detected beneaththe lateral liver and the abdominal wall.

Patterns of pneumoperitoneumon supine AXR

• Rigler’s sign: free intraperitoneal airoutlines the outside of the bowel wallwith luminal gas outlining the inneraspect (Fig. 5.12).• Gas may accumulate between the anterior aspect of the liver and the abdominal wall causing increasedlucency in the right upper quadrant (Fig. 5.12).• Air may track into Morison’s pouch(an intraperitoneal recess between liverand right kidney).• Air may outline peritoneal ligaments(e.g. falciform and ligamentum teres).

Pneumoperitoneum on erect CXR

An erect CXR is extremely sensitive indetecting small amounts of free in-traperitoneal air (Figs 5.13 & 5.14). Butdo not be caught out — air within thegastric fundus can simulate air beneaththe left hemidiaphragm, as can fat.Bowel can also intersperse between liverand right hemidiaphragm, mimickingfree air (Chilaiditi’s syndrome) (Fig.5.15).


Other imaging

CT is extremely sensitive at detectingsmall amounts of free intraperitoneal air(Fig. 5.16).

Occasionally, water-soluble contraststudies are used to identify sites of bowelperforation (remember barium is con-traindicated in suspected perforation —it causes peritonitis).

Pneumoretroperitoneum

Retroperitoneal portions of the bowel(duodenum, ascending or descending

colon, rectum) can also perforate. Airmay be seen in relation to the psoasmuscles or within the pararenal regions.

Crohn’s disease

Crohn’s disease is a chronic relapsingdisease that can affect any part of thegastrointestinal tract from the mouth to the anus. Patients with the small bowel involved present with pain, diarrhoea and weight loss and often aright iliac fossa mass. The small bowel is involved in 80% of patients, with

Fig. 5.12 Supine AXR in a patient with pneumoperitoneum secondary to appendixperforation. Rigler’s sign is well demonstrated, with small bowel wall clearly out-lined by luminal air within (paired small arrows) and free intraperitoneal airoutside (single short arrow). Note also increased lucency in right upper quadrant(long arrow) resulting from free air between liver and abdominal wall.

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the terminal ileum the most common location.

Small bowel barium follow-throughor small bowel barium enema (entero-clysis) are the investigations of choicefor suspected small bowel Crohn’sdisease, or for evaluation of diseaseextent or disease in relapse. Small bowelenema involves the passage of a feedingtube into the jejunum and then injection

of diluted barium to opacify the smallbowel. It is more accurate than smallbowel follow-through, which involvesdrinking a barium solution, but hasdrawbacks. Patients often do not toleratenasojejunal intubation and the proce-dure may be time-consuming with a highradiation dose. Many centres use smallbowel follow-through initially.

Fig. 5.13 Erect CXR demonstrating a small amount of subdiaphragmatic free in-traperitoneal air (black arrow). Note pericardial calcification secondary to previoustuberculous pericarditis (short arrows).


Barium features of small bowelCrohn’s disease (Fig. 5.17)

Fig. 5.14 Erect CXR with extensive subdiaphragmatic free air.

EarlySmall bowel fold thickeningHyperplasia of lymphoid follicles

with or without mucosal erosions(aphthous ulcer)

Aphthous ulcers enlarge and

deepen transmurally — ‘rose-thorn’ulcers

LateDeep ulcers or fissuresPseudopolypsTransverse and longitudinal fissures

may surround pseudopolyps —‘cobblestone’ pattern

Separation of oedematous bowel loops

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Fig. 5.15 Erect CXR in a patient with large bowel interposed between liver andright hemidiaphragm (arrow; Chilaiditi’s syndrome). This can be confused withpneumoperitoneum.

Lesions often occur in multiple sitesalong the bowel, giving rise to the de-scription of ‘skip’ lesions. Strictures arecommon, especially in the terminalileum and these may cause obstruction,requiring surgical intervention.

Complications of small bowelCrohn’s disease

• Fistula formation: in up to one-thirdof patients, with ileocaecal and entero-

enteric most common. These are usuallywell demonstrated on barium examina-tion. Contrast can be inserted via acatheter placed into the fistula to demon-strate deep connections (fistulogram).• Abscess: caused by local perforationand best demonstrated with CT (whichcan also be used to guide percutaneousdrainage).• Adenocarcinoma: increased inci-dence, especially at the site of chronicfistulation.


Malabsorption

Malabsorption can be caused by:• Digestive enzyme deficiency (e.g.chronic pancreatitis, Crohn’s terminalileitis)• Mucosal abnormality (e.g. coeliacdisease, widespread Crohn’s disease,Whipple’s disease, short bowel syndrome)• Secondary to bacterial overgrowth(e.g. diverticulosis, blind-loop syn-drome).

Malabsorption can be difficult to di-

agnose. Clinical features include steator-rhoea, diarrhoea, weight loss and fea-tures of anaemia or vitamin deficiency. Arange of haematological and biochemicaltests are available but intestinal muco-sal biopsy is frequently the diagnostic investigation.

Barium studies

Small bowel follow-through or smallbowel enema (see above) are the imaginginvestigations commonly requested ini-tially. A range of abnormalities may bedemonstrated on barium studies, but

Fig. 5.16 Post-contrast CT in a patient with pneumoperitoneum following per-foration of sigmoid diverticular disease. Free air is identified anterior to the liver(long arrows) and as small pockets within the upper abdomen (small arrows).

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Fig. 5.17 Spot views of the terminal ileum in a patient with Crohn’s disease. Thereis diffuse abnormality of the distal small bowel, which is narrowed, with irregularmucosa (arrows). Ulceration is present. Note separation of oedematous smallbowel loops.


Fig. 5.18 Film from a small bowel follow-through in a patient with jejunal diver-ticulosis. Multiple diverticula are present in the jejunum (arrows); these cause mal-absorption secondary to bacterial overgrowth in diverticula and may requiresurgery if medical management fails.

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these are frequently non-specific. Lookfor regular or irregular mucosal foldthickening and small bowel dilatation.

Barium examination may reveal morespecific causes (e.g. jejunal diverticulosis[Fig. 5.18], Crohn’s disease).

CT and MR

CT and MR may be useful for further assessment of the small bowel wall andalso of adjacent mesentery, lymph nodes,liver and spleen if systemic disorder (e.g.lymphoma) is suspected (Fig. 5.19).

Further reading

Gore RM, Levine MS, eds. Textbook ofGastrointestinal Radiology, 2nd edn.Philadelphia: Saunders, 2000.

Levine MS, Rubesin SE, Laufer I, eds.Double Contrast Gastrointestinal Radiology, 3rd edn. Philadelphia:Saunders, 2000.

Miller FH, ed. The Radiological Clinics ofNorth America: Radiology of the Pan-creas, Gall bladder and Biliary Tract,Vol. 40. 2002.

Fig. 5.19 Post-contrast CT in a patient with biopsy-proven lymphomatous infiltra-tion of the small bowel. There is extensive mesenteric and para-aortic adenopathyin association (long arrows) and a lymphoma deposit is also seen in the spleen(short white arrow). The normal enhancing aorta is indicated (black arrow).

This chapter covers:Common conditions• Appendicitis• Colonic obstruction• Diverticular disease• Neoplasia: polyp, carcinoma• Sepsis• Colitis• VolvulusCommon presentations in whichimaging can help• Altered bowel habit: obstruction,carcinoma, diverticular disease• Acute abdominal distension: obstruction• Acute abdominal pain: obstruc-tion, colitis, diverticulitis• Rectal bleeding: carcinoma, di-verticular disease, colitisLook for hepatomegaly or an abdominal mass on clinical examination.

Patients should undergo perianaland rectal examination at presenta-tion. This task is often delegated tothe house officer. If you are unsure,ask for help from a senior colleague.

Imaging strategy

Initial imaging in acute presentationsusually involves a supine AXR and anerect CXR. CXR may demonstrate free intraperitoneal air beneath the diaphragm (see Chapter 5), and manypatients who are acutely ill may have evi-dence of chest sepsis or cardiac failure

also. Supine AXR will give informationconcerning small and large bowel gaspattern, free intraperitoneal air, softtissues and bony structures.

Once initial clinical assessment hasbeen made and a working diagnosis formulated, many patients will requirefurther imaging. Discuss the case withthe radiologist to identify the best way (including endoscopy) to reach a diagnosis.

US

US in colorectal disease can be helpfulfor initial assessment of:• Possible bowel-related mass• Free fluid or abscess formation• Solid organs.

By their nature, many pathologies ofthe colon are associated with significantbowel gas and when combined with anelderly, immobile or obese patient theuse of US may be limited.

CT

CT can provide significant additional diagnostic information in patients withbowel-related masses and suspected in-flammatory disease or malignancy. CT isincreasingly being used as an early inves-tigation in the elderly and frail to avoidrectal contrast studies.

Contrast enema

This is an essential tool for evaluation of

Chapter 6: The lower gastrointestinal tract

81

82 CHAPTER 6

the rectum and colon (combined withendoscopy).

Unprepared contrast enema, usuallyusing water-soluble iodinated contrast,may be used to exclude an obstructinglesion in patients with large bowel ob-struction. Mucosal detail is poor and, ifthe study is negative, follow-up bariumenema or colonoscopy is often needed.

Contrast enema should not be per-formed in patients at risk of perforation(e.g. toxic megacolon). Barium causesperitonitis if it extravasates outside thebowel and should not be used in patientswho may have perforation or where recentdeep biopsies have been performed.Water-soluble contrast should be used.

Maximum diagnostic information isobtained using the double-contrast technique (air and barium) with goodbowel preparation. However, a significantnumber of elderly patients cannot retainair and/or barium and may be immobile.In some of these patients, CT may beused to exclude a gross mass lesion.

MR

MR has a role in staging colorectal car-cinoma, but its use is currently limitedotherwise.

NM

This has a limited role, but it can be usedto assess the extent of inflammatorycolitis.

Appendicitis

This is the most common surgical emergency, with a peak incidence in thesecond and third decades.

The classic signs of appendicitis areabsent in up to one-third of patients and there is a significant rate of clinicalmisdiagnosis.

Imaging may be particularly helpfulin:• The elderly, where symptoms andsigns may be minimal• Children, where history and examina-tion are often difficult• Young women who may have a gynae-cological cause for pain.

Accurate and appropriate imagingreduces the number of normal laparo-tomies and will help to exclude othercauses of appendix-type pain. However,imaging is often not needed followingclinical assessment.

AXR

Look for:• Laminated calcified appendicolith(10–15% of patients)• Evidence of ileus, often localized tothe right iliac fossa• Distortion of psoas margin• Bubbles of air in associated appendixabscess.

US

This represents a non-invasive modalityfor assessment of atypical patients. US is most accurate in children and youngand/or pregnant women, where the appendix is not obscured by gas. US fea-tures of appendicitis include identifica-tion of the appendix as an abnormal,thick-walled and non-compressiblestructure with a distended lumen (Fig.6.1). An appendicolith or associatedabscess formation may also be seen.

LOWER GASTROINTESTINAL TRACT 83

CT

CT is highly accurate in the evaluation ofappendix inflammation and local extent.It is the technique of choice in theelderly, obese or very tender patients orwhere US has been unhelpful and clini-cal concern persists.

Barium studies

Barium studies of small or large bowelmay be helpful in some patients whereinitial US or CT have indicated bowelpathology not clearly related to the appendix.

Colonic obstruction

The major causes of large bowel ob-struction are carcinoma, diverticulardisease and volvulus. Carcinoma, mostcommonly within the sigmoid, accountsfor > 50% of cases. Symptoms are of ab-dominal distension and pain with associ-ated vomiting. A mass may be palpable.

The integrity of the ileocaecal valve isimportant. If it is competent, this pre-vents passage of air into the small bowelif the large bowel is obstructed, leadingto rapid and pronounced colonic andcaecal dilatation, with the risk of is-chaemia and perforation. An incompe-tent ileocaecal valve allows colonicdecompression, with passage of air into

Fig. 6.1 Transverse ultrasound section of the appendix in a patient with appendici-tis. The appendix has a thickened wall (callipers) with a dilated lumen (arrow) anda target appearance.

84 CHAPTER 6

the small bowel. Onset of symptoms maythen be more gradual.

AXR

On supine AXR, look for:

• Dilated gas-filled colon proximal tothe site of obstruction (Fig. 6.2)• Paucity of gas in collapsed colon distalto the obstruction• Haustral pattern to differentiate fromsmall bowel

Fig. 6.2 Supine AXR in a patient with large bowel obstruction secondary tosigmoid carcinoma. There is gaseous distension of the large bowel down to the leftpelvis at level of obstruction (arrow).


• Small bowel dilatation also if ileocae-cal valve incompetent• Evidence of perforation.

If large bowel obstruction is diag-nosed, rectal and sigmoidoscopic exami-nation should be performed to exclude alow obstructing lesion. If negative, thepatient should be considered for contrastenema examination of the large bowel.

CXR

On erect CXR, look for evidence of freeintraperitoneal air, lung metastases andother pathology.

Contrast enema

Although barium is the ideal agent, it cancause problems. It is contraindicated inpatients at risk of perforation and cancause impaction if no obstruction ispresent, as well as interfering with futurecolonoscopy and CT (see Chapter 2). Io-dinated contrast (water-soluble) is oftenused and will exclude gross obstruction(Fig. 6.3).

CT

This can be useful in assessing bowel and adjacent structures, particularly ifpatients are elderly or frail and cannot tolerate a contrast enema.

Pseudo-obstruction

Marked dilatation of the large bowelmay occur in elderly, bedridden patientsor those with neurological or psychiatricdisorders. Gaseous distension often in-volves the rectum also, and faecal loadingmay be present. Sigmoidoscopy andcontrast enema are often needed to

exclude a mechanical obstruction in pa-tients who do not settle with conserva-tive treatment.

Diverticular disease of the colon

This is the most common colonic diseasein the West, with diverticula present inup to 50% of people of 50 years of age,with the sigmoid colon most frequentlyinvolved. Diverticula are out-pouchingsof colonic mucosa and submucosa thatpenetrate between circular muscle fibres.Circular muscle hypertrophy and mus-cular spasm are common. Diverticulardisease is generally diagnosed duringbarium enema examination, often as anincidental finding (Fig. 6.4). Complica-tions of diverticular disease include diverticulitis, fistula formation andhaemorrhage.

Diverticulitis

Diverticulitis is the most common com-plication of diverticular disease, occur-ring in up to 25% of patients. It occurssecondary to mucosal abrasion by faecalmatter within a diverticulum, causinglocal perforation, inflammation andabscess formation. Patients present withleft iliac fossa pain, fever and often an inflammatory mass.

AXR

AXR may demonstrate air within anabscess or secondary ileus. Chronic in-flammation and stricturing with largebowel obstruction is unusual.

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Fig. 6.3 Water-soluble contrast enema film from splenic flexure region shows anobstructing carcinoma. Note ‘apple core’ appearance of stricture with shouldering.


Barium enema

This is excellent at demonstrating diver-ticular colonic muscular hypertrophyand spasm, and local contrast extravasa-tion into walled-off pericolic abscess. Pa-tients often do not tolerate barium enemaduring an acute episode, and enema doesnot delineate pericolic inflammation.

US

US is often requested as a first-line

investigation for patients with left iliacfossa pain and may demonstrate bowel-wall thickening, a mass or fluid collectionin diverticulitis. However, US is oftennon-diagnostic.

CT

Patients often proceed to CT, which accu-rately delineates diverticula, bowel-wallthickening, pericolic inflammatory changeand abscess formation (Fig. 6.5), and willguide aspiration or drainage of abscess.

Fig. 6.4 Film from double-contrast barium enema series showing florid sigmoid di-verticular disease. Note diverticula and circular muscle hypertrophy. The sigmoidcolon is tortuous and is an area of weakness for barium enema —mucosal lesionscan easily be overlooked. Another problem here is the presence of significant smallbowel reflux of barium, which partially obscures the sigmoid region.

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Fistula formation

A fistula is a communication betweentwo surfaces lined by epithelium. Acolovesical fistula is the commonest type of indiverticular disease and is secondary to recurrent inflammation —these patients present with pneuma-turia. Air in the bladder may be apparenton AXR. The fistula can be demarcatedduring barium enema. CT is very sensi-tive at detecting air in the bladder, with

associated changes in the sigmoid colon. Coloenteric (Fig. 6.6), colovaginaland colocutaneous fistulae may alsooccur.

Remember that fistula formation alsooccurs with malignancy and this shouldbe excluded.

Haemorrhage

This is not related to diverticulitis. It occurs in 30–50% of patients with diverticular disease and may be life-threatening. Haemorrhage is usuallyself-limiting, but re-bleeding is common.

Barium enema or colonoscopy is indi-cated if bleeding is to be investigated as an outpatient. Catastrophic haemor-rhage may require angiography to iden-

Fig. 6.5 Post-contrast CT demonstrates a sigmoid colon diverticular abscess. Thereis an irregular mass containing fluid and air (long arrow). Thick-walled sigmoidcolon abuts the abscess (short arrow).

Note:It is important to remember that perforated carcinoma can mimic diver-ticulitis, and once the acute episodehas settled, patients should undergoendoscopic examination.


tify the site and to allow potential em-bolization of the bleeding vessel.

Colorectal carcinoma

Colorectal carcinoma is the second mostcommon cause of cancer death. Riskfactors include family history, adenoma-tous polyposis syndromes, chronic ul-cerative colitis and Crohn’s disease. Thevast majority of colorectal carcinomasbegin as benign adenomas, which growover time and undergo malignant trans-formation. Adenomas of > 1 cm are atrisk and > 2 cm malignancy is likely

(50%). Fifty per cent of carcinomas arein the rectum or sigmoid and in range ofthe flexible sigmoidoscope.

Patients with a colorectal carcinomaare at risk of synchronous (carcinomaelsewhere in large bowel) and metachro-nous (colonic carcinoma at a later date)lesions and it is important to evaluate theentire colon at the time of diagnosis.

Polyp detection

Clearly, polyp detection and removalprior to malignant change is essential forprevention of colorectal carcinoma, al-though large-scale population screening

Fig. 6.6 Film from a single-contrast barium enema in the sigmoid region. There isirregular narrowing in the mid-sigmoid region (long arrow) with adjacent divertic-ular disease. Contrast passes via a fistula (short arrow) to communicate with smallbowel. This was secondary to diverticular disease, but exclusion of malignancy is essential.

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is still under investigation. Severalimaging modalities are available; all havestrengths and weaknesses. Colonoscopyis often preferred.

Barium enema

Double-contrast barium enema is highlyaccurate and comparable to colonoscopyin the identification of polyps > 1 cm.This accuracy falls off < 1 cm in size.Completion rate to the caecum is betterwith barium enema. Diagnostic accuracyis impaired:• With poor bowel preparation• If patients cannot retain air or barium• With tortuosity of the bowel, espe-cially in the sigmoid• With extensive associated diverticulardisease• The lower rectum is often not wellseen, particularly if a balloon catheter isused.

Adenomatous polyps may be:• Pedunculated (on a stalk): where risk ofmalignancy is low (Fig. 6.7)• Sessile (flat): villous change and malig-nancy is more likely (Fig. 6.8).

Colonoscopy

Endoscopic assessment of the colonallows identification and also removal ofpolyps. This modality is theoretically theideal, but does have the complications ofsedation and perforation, and technicalfailure is common, for similar reasons, tobarium enema.

CT colonography

This three-dimensional virtual-realityCT technique, following air insufflationof the colon, has shown initial promisingresults.

Fig. 6.7 Decubitus spot film of the hepatic flexure from a double-contrast bariumenema series demonstrates a pedunculated polyp on a stalk (arrows). Note gravi-tational pooling of barium.


Adenocarcinoma

This may be diagnosed by the threemodalities outlined above — again, colo-noscopy offers the opportunity for histological examination.

Barium enema

Look for:• Fungating, polypoidal lesion• Annular, ulcerating — ‘apple core’with shouldering (Fig. 6.9)• Scirrhous lesion (uncommon).

CT

CT is useful for identifying primarytumour and is the most reliable methodfor staging:• Luminal mass and bowel wall thicken-ing (Fig. 6.10)• Stranding and nodularity of adjacentfat — may indicate local invasion• Invasion of local structures• Presence of mesenteric disease, as-cites, significant adenopathy• Liver and lung metastases.

Fig. 6.8 Film from double-contrast barium enema demonstrates a large sessilepolyp in the upper rectum (arrow). The surface of the polyp is irregular and, whencombined with the size, malignancy is likely.

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US

Transabdominal US can identify bowel-related masses and will assess the liverparenchyma for metastases.

Transrectal US and MRI accuratelydelineate the layers of the rectal wall andare useful for local staging of disease.Bulky and locally invasive rectal car-cinomas will receive local radiotherapyprior to surgery.

Local complications ofcolorectal carcinoma

• Obstruction: this is common (seeearlier). In patients unfit for immediate

surgery, radiological insertion of an ex-panding metallic stent over a guidewirecan relieve obstruction, giving palliation.Surgery can be considered when thepatient’s condition has improved.• Fistula formation (see earlier)• Perforation: patients may go straightto theatre for surgery.

Follow-up of treated colorectal cancer

Residual large bowel post-resection isfollowed-up regularly, either endoscopi-cally or by barium enema.

CT is the modality currently of choicefor identifying extraluminal local recur-

Fig. 6.9 Film from double-contrast barium enema in a patient with a large trans-verse colon carcinoma (large arrow). There is irregular stricturing of the bowelwith shouldering apparent. Note lung metastases at lung bases (small arrows).


rence or metastatic disease and is also used to monitor patients withknown metastatic disease undergoingtreatment.

Hepatic metastases may be consideredfor ablation or resection (see Chapter 7).

Abdominal sepsis

Sepsis in the abdomen is a very impor-tant cause of patient mortality, mor-bidity and increased length of hospitalstay. Cases are often complex and greatbenefit may be obtained through directdiscussion with a radiologist.

This section concentrates on in-traperitoneal, subphrenic, psoas andpelvic abscess formation. Diverticular,

pancreatic and hepatic abscesses arecovered elsewhere.

Intraperitoneal abscess

Usually results from secondary infectionof collections of blood, bile or ascites andmay arise in patients who have under-gone bowel or hepatobiliary surgery. Ifpatients have pyrexia or a raised whitecell count only, with no significant ab-dominal symptoms, make sure there isno evidence of chest, urinary or skinsepsis (e.g. infected cannula) prior tofurther investigations.

AXR

AXR may show an ileus or mottled

Fig. 6.10 Post-contrast CT in a patient with caecal carcinoma. There is markedthickening of the caecal wall (arrows).

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gas densities within an intraperitonealabscess and is worth arranging if thereare abdominal symptoms.

US

US is the next investigation of choice for the identification of abdominal andpelvic fluid collections. Bandaging, suturing, pain, obesity and gas oftendegrade US; CT would then be recommended.

Percutaneous drainage under US orCT guidance can be performed in post-operative abscess formation.

Subphrenic abscess

This usually follows bowel surgery orappendicectomy.

AXR

AXR may show mottled gas densities inabscess but air–fluid level and sympa-thetic pleural effusion is best appreci-ated on erect CXR (Fig. 6.11).

US and CT

US or CT will confirm diagnosis ifnecessary.

Fig. 6.11 Erect CXR demonstrates a large right subphrenic abscess post-cholecystectomy. Note air–fluid level (arrows) and right basal pleural effusion.


Psoas abscess

Psoas abscess often relates to adjacentvertebral, bowel or renal sepsis. Look forevidence clinically of psoas irritationand painful hip flexion.

AXR

AXR may show psoas enlargement andabnormal gas densities. Look carefullyfor renal tract calcification and vertebralbody abnormality (tuberculous ormetastatic bony involvement).

US and CT

US is often limited in evaluation of theretroperitoneum and CT is the idealmodality for psoas assessment andabscess drainage (Fig. 6.12).

Colitis

The three most common forms of colitisare dealt with here: ulcerative, Crohn’sand ischaemic.

Ulcerative colitis

This is a common inflammatory diseaseof the colon and rectum of uncertain aetiology, which initially involves thebowel mucosa but extends to involvedeeper layers. The disease usually commences in the rectum and extendsproximally, with the diagnosis made on sigmoidoscopic biopsy. The terminalileum may be involved (‘backwashileitis’).

Ulcerative colitis runs a variable clinical course — usually with periods of

Fig. 6.12 CT of left psoas abscess secondary to renal calculus disease. A large sep-tated fluid collection involves the left psoas and iliacus muscles (long arrow). Notenormal right psoas muscle (short arrow).

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relapse and remission, although an acuteand fulminant illness may occur. Extra-colonic manifestations are recognised(e.g. arthritis, iritis, rash) in 10%.

AXR

Look for:• Extent of faecal residue — where it is absent this is suggestive of colitic involvement• Bowel wall thickening• Colon diameter (> 6 cm in traversecolon suspicious of toxic megacolon).Colon narrows in chronic disease• Loss of haustration or mural thickening• Evidence of perforation.

Barium enema

This is a useful investigation in ulcera-tive colitis. It is used to assess dis-ease extent, to differentiate ulcerative colitis from other forms of colitis and to detect disease complications (e.g. malignancy).

Barium enema features of ulcerative colitis

Complications of ulcerative colitis

• Toxic megacolon: an acute fulminantillness with colonic dilatation (> 6 cm)and high risk of perforation. It carries ahigh mortality. Toxic megacolon can bediagnosed on AXR (Fig. 6.14). Contrastenema should not be performed becauseof the risk of perforation.• Colonic adenocarcinoma: annual inci-dence of 10% after first decade of thedisease. Carcinomas are often multipleand flat, and scirrhous in nature (Fig.6.13). Patients with ulcerative colitisshould undergo regular colonoscopicscreening with random biopsies to detectdysplasia.

Crohn’s colitis (see Chapter 5)

This is a granulomatous colitis particu-larly involving the right colon, withsparing of rectum and sigmoid colon.However, perianal disease (abscess,fistula, ulceration) is strongly suggestiveof Crohn’s.

AXR

Look for:• Extent of faecal residue, bowel-wallthickening, haustral loss or thickening(Fig. 6.15)• Also look for gallstones, sacroiliitisand avascular necrosis (femoral heads),which are associated with Crohn’s (andulcerative colitis).

Acute changesGranular mucosa pattern‘Collar-stud’ ulcers (shallow ulcera-

tion underlying mucosa)Haustral thickening (‘thumb-printing’)Inflammatory polyps

Chronic changes (Fig. 6.13)Haustral lossColon shorteningLuminal narrowing (‘lead-pipe’ colon)

Postinflammatory polypsTerminal ileitis


Fig. 6.13 Films from double-contrast barium enema in a patient with long-standing ulcerative colitis involving the colon around to the hepatic flexure. Notegranular mucosa with colon lumen narrowed and haustral pattern absent. A complicating carcinoma is seen at the splenic flexure (arrow). Note normal haustral pattern in the right colon.

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Fig. 6.14 AXR in a patient with ulcerative pancolitis and toxic dilatation of thetransverse colon. Note absence of faecal residue and thickening of haustra(arrows). There is a pelvic intrauterine contraceptive device (IUCD).


Barium enema features of Crohn’s colitis Complications of Crohn’s colitis

• Fistula: enterocolic, enterocutaneous,perianal• Toxic megacolon: less common thanulcerative colitis• Adenocarcinoma: ileum and colon• Abscess formation.

Ischaemic colitis

Patients present with acute abdominalpain and rectal bleeding, and ischaemiccolitis tends to involve the splenic flexureand descending colon at the ‘watershed’area of blood supply between superiorand inferior mesenteric arteries. It ismore common in the elderly with ahistory of cardiovascular disease.

Fig. 6.15 AXR in a patient with Crohn’s colitis. The transverse colon is narrowedand thumb-printing (mucosal oedema) is present (arrows).

EarlyNodular lymphoid hyperplasiaAphthous ulcers‘Cobblestoning’ resulting from longi-

tudinal and transverse ulcers sepa-rated by oedema — ulcers are deep

Thickened haustraInflammatory pseudopolypsDiscontinuous involvement (‘skip

lesions’)

LateLoss of haustrationStrictures (‘string’ sign)FistulaePseudodiverticula

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AXR

AXR may show segmental muco-sal oedema with thumb-printing. Diag-nosis can be confirmed with bariumenema.

CT

CT demonstrates segmental muralthickening, and also intramural andportal venous gas in severely ill patients(Fig. 6.16).

Caecal volvulus

Caecal volvulus accounts for 3% ofcolonic obstructions and is associatedwith malrotation of the right colon and a

long mesentery allowing the caecum torotate so it lies in the mid-abdomen or,more commonly, the left upper quadrant.

AXR

AXR reveals a dilated gas-filled caecumin the left upper quadrant (Fig. 6.17).The medially placed ileocaecal valve maycause an indentation, giving a kidney or‘coffee-bean’ appearance.

If the ileocaecal valve is incompetent,there will be coexisting small bowel di-latation. The normal caecal gas patternis absent in the right iliac fossa.

A contrast enema is helpful if AXR isatypical, with the tapered end of the obstructed contrast column pointingtoward the torsion.

Fig. 6.16 Post-contrast CT in a severely ill patient with ischaemic colitis. Air is iden-tified peripherally distributed within portal veins in the liver (small arrows). Ascitesis present (large arrows).


Sigmoid volvulus

This accounts for 1–2% of colonic ob-structions and tends to occur in elderlyor psychiatric patients with large redun-dant sigmoid colons.

Patients present with abdominal painand distension.

AXR

On supine AXR, look for:• Markedly dilated loop of sigmoid

colon extending into the upper abdo-men, converging to the left iliac fossa(Fig. 6.18)• Often dilated large bowel proximally• Absence of gas in the rectum.

A contrast enema may be required insome patients where radiographicalfindings are equivocal. This demon-strates a tapered narrowing of the con-trast column at level of volvulus.

Once the diagnosis has been made, aflatus tube can be passed to decompressthe sigmoid colon to allow patient stabi-lization prior to sigmoid colectomy.

Fig. 6.17 Supine AXR in a patient with caecal volvulus and an incompetent ileo-caecal valve. Note distended air-filled caecum in left upper quadrant (large arrow)and dilated small bowel loops (small arrows).

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Fig. 6.18 Supine AXR in a patient with sigmoid volvulus. Note markedly dilatedsigmoid colon (arrows) with ‘inverted-U’ configuration, converging to the left iliacfossa. Calcified gallstones are seen in the right upper quadrant.


Further reading


Levine MS, Rubesin SE, Laufer I, eds.

Double Contrast Gastrointestinal Radiology, 3rd edn. Philadelphia:Saunders, 2000.


This chapter covers:Common conditions• Gallstones and their complications• Hepatic metastases• Hepatic abscess• Cirrhosis• Acute and chronic pancreatitis• Carcinoma of the pancreas• Bile duct stricture• Abdominal traumaCommon presentations in whichimaging can help• Acute abdominal pain: gall-stones, cholecystitis, pancreatitis• Chronic abdominal pain: gall-stones, hepatomegaly (cirrhosis,metastases, hepatitis)• Jaundice: obstructive or hepatic• Non-specific symptoms alsooccur in many conditions (e.g.nausea, vomiting, weight loss,malaise)

Imaging strategy

Imaging will depend on the initialworking differential diagnosis, takinginto account results of blood tests,patient age and previous medical history.

The general principles of imagingapply. Investigations should be tailoredto each patient and the use of ionizingradiation kept to a minimum. The use ofrelatively non-invasive investigations,US and MRI, should be encouraged.

Discussion of individual cases with aradiologist is often extremely helpful inthis area and will allow prioritization andease of access.

When admitted acutely with upperabdominal pain and vomiting, most pa-tients will have a supine AXR and erectCXR performed, as perforated viscus is often important in the differential diagnosis.

AXR

AXR gives often limited diagnostic in-formation relating to the liver, biliarytree and pancreas. Look for hepato-megaly, abnormal patterns of calci-fication, bowel gas pattern, abnormaldistribution of air (e.g. in gall bladderwall or biliary tree). If you are unsure,ask a senior colleague.

US

Following initial clinical assessment andplain radiography, US is frequently requested.

US as a modality has significant advantages:• It is readily available• It is safe, with no ionizing radiation• It is accurate in assessing the biliarytree, the gall bladder for mass or stonesand the hepatic parenchyma.

However, US does have some drawbacks:• It is operator dependent.• It is patient dependent. Patient

Chapter 7: Hepatobiliary andpancreatic imaging

104

HEPATOBILIARY AND PANCREATIC IMAGING 105

obesity or large amounts of bowel gasoften significantly degrade the image.The pancreas in particular is oftenpoorly seen, unless an endoscopic tech-nique is used.

US is a good screening tool, however,and a normal, good quality examinationmay obviate the need for further imaging.

CT

CT is the investigation of choice forseveral conditions, particularly if initialUS is equivocal. Focal liver lesions and the pancreas are well-demonstratedwith CT, as is the retroperitoneum and mesentery.

CT involves significant amounts of ion-izing radiation and usually also requiresadministration of oral and intravenous iodinated contrast. Patient cooperationwith breath-holding is important.

CT and US can be used to guidebiopsy and drainage procedures (seeTable 7).

MR

The advent of high-quality MR unitsand magnetic resonance cholangiopan-creatography (MRCP) has had a signifi-cant impact on hepatobiliary imaging.MRCP has largely replaced diagnosticendoscopic retrograde cholangiopancre-atography (ERCP) in many centres. MRis used often as problem-solving tool fol-lowing initial US and CT.

MR does not involve ionizing radia-tion or iodinated contrast and can beused instead of CT in certain patients(e.g. young, iodine allergy). MR doeshave some contraindications (seeChapter 2), and claustrophobia may be aproblem.

NM

NM is not generally used as a first-lineinvestigation for the liver, biliary tree orpancreas, and will not be covered indetail in this chapter.

Diseases of the gall bladder

Gallstones are common and most frequently occur in overweight middle-aged females. Stones are usually choles-terol-based, although pigment stones dooccur. This section concentrates on thecomplications of gallstone disease andhow imaging may assist in diagnosis andmanagement.

Acute cholecystitis

Patients most commonly present withacute right upper quadrant pain on abackground of more chronic biliarysymptoms. The vast majority of casesare secondary to calculus impaction inthe cystic duct, with gall bladder outflowobstruction and secondary bacterial infection (10% of cases are acalculous).

Imaging is important to:• Confirm the diagnosis and excludeother causes of right upper quadrantpain• Evaluate potential complications (seebelow).

AXR

AXR can provide useful diagnostic in-formation and is generally performed(supine) on admission. About 10% ofcalculi are radio-opaque on radiographsbecause of calcium content, and somecomplications of cholecystitis (e.g.

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air–calcium in gall bladder wall or ileus)may be apparent.

US

This represents the imaging modality ofchoice for the evaluation of suspectedgallstones and cholecystitis, with re-ported accuracies of > 95%. Gallstonesare seen as hyperechoic foci with dis-tal acoustic shadowing. Sonographicchanges of acute cholecystitis include(Fig. 7.1):• Positive Murphy’s sign during scanning• Gallstones in the gall bladder• Gall bladder wall thickening, with orwithout free fluid.

The accuracy of US is reduced in theobese, in patients with extreme tender-ness preventing examination and in thepresence of large amounts of bowel gas.

CT

CT is not generally used in the initial as-sessment of acute cholecystitis but maybe useful if complications (e.g. gallbladder perforation with or withoutabscess) are suspected. CT is less accu-rate than US in the detection of calculi.

NM

Cholescintigraphy is accurate in the as-sessment of acute cholecystitis, but its

Fig. 7.1 US of acute cholecystitis. There is thickening of the gall bladder wall (longblack arrow) and stones are seen in the gall bladder (short white arrow) withacoustic shadowing in association.


use is generally limited to cases with negative sonography.

Complications ofacute cholecystitis

Gall bladder empyema and perforation

Cystic duct obstruction secondary tocalculus or oedema may cause gallbladder distension (mucocele) and infection may supervene to produce an empyema.

Ultrasound features of empyemainclude gall bladder calculi or sludge,and pronounced mural thickening.These patients are at high risk ofperforation.

Ultrasound- or CT-guided drainageof gall bladder empyema should be con-sidered in patients unfit for immediatesurgery.

Emphysematous cholecystitis (rare)

This is caused by calculus or oedematousobstruction of the cystic duct with sec-ondary ischaemia of the gall bladder walland infection with gas-forming organ-isms (e.g. Clostridium perfringens). Dia-betics are predisposed and mortality ishigh.

On AXR, look for air in the gallbladder wall and air–fluid level in the gallbladder. With US, look for calculi and airin the gall bladder wall.

Chronic cholecystitis

This is caused by recurrent episodes ofacute inflammation secondary to calculiand intermittent cystic duct obstruction.It may be difficult to differentiate clini-cally the contraction of a chronically

inflamed gall bladder from acute inflammation.

AXR

Look for calcified gallstones, calcifiedgall bladder wall (Fig. 7.2) and radio-opaque bile resulting from calcium car-bonate (‘limy bile’).

US

Look for calculi and contracted thick-walled gall bladder.

Complications of chroniccholelithiasis

Porcelain gall bladder

This is rare, resulting from chronic in-flammation of the gall bladder wall withcalcification. It is associated with gall-stones and malignancy.• AXR: calcification in gall bladder wall(Fig. 7.2)• US/CT: calcification and carcinomaas luminal mass.

Gallstone ileus

This occurs in chronic cholecystitis with erosion of calculus into the gastrointestinal tract. Stone impactionmay occur, with obstruction at areas ofluminal narrowing (e.g. ileocaecal valve).• AXR: look for triad of air in biliary tree, dilated small bowel loopsand gallstone within bowel loop (Fig.7.3). The calculus is often not seen ifradiolucent and surrounded by fluid.Biliary tree air does not extend to theliver edge and tends to have acentral/portal distribution.

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Gall bladder carcinoma

This has strong association with gall-stones and patients present with symp-toms of right upper quadrant pain,weight loss and jaundice.

• US: useful initially and may show agall bladder mass, bile duct dilatationand liver metastases. However, accessmay be limited (see above).• CT/MR: used for further assessmentand accurate in the detection of local

Fig. 7.2 AXR demonstrating curvilinear calcification of the gall bladder wall inporcelain gall bladder (arrow).


Fig. 7.3 AXR of gallstone ileus. There are dilated loops of small bowel with air inthe biliary tree (arrows). A calcified gallstone is not identified but a stone wasfound impacted at the ileocaecal valve at laparotomy.

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liver invasion and extrahepatic nodaldisease in addition, rendering lesions inoperable.

Choledocholithiasis

Ninety-five per cent of patients withcommon duct calculi have gallstones inthe gall bladder and 15% of patientswith gallstones also have stones in thecommon duct.

Presenting features of choledo-cholithiasis include pain, sepsis, pancreatitis or jaundice.

AXR

AXR may visualize stones (10% areradio-opaque).

US

This is the most useful initial imagingmodality, but degradation due to bowelgas is important and up to one-third ofdistal duct stones are missed. US is accu-rate in the assessment of intrahepaticand common duct dilatation and guidesthe need for further imaging.

MRCP

This uses a fast T2-weighted sequence,where bile is high signal and stones areseen as filling defects (Fig. 7.4). It ishighly accurate for the demonstration ofduct stones and has replaced diagnosticERCP in many centres.

ERCP

Is accurate in the detection of commonduct stones and allows therapeutic inter-

vention (e.g. stent placement, sphinc-terotomy) but is invasive. Complicationsinclude pancreatitis, cholangitis or perforation and haemorrhage post-sphincterotomy.

CT

CT is less accurate in the detection ofcommon duct stones, and a combination ofUS and MRCP is more frequently used.

Cholangiography

The ducts can be visualized and stonesdetected intra-operatively by direct iodi-nated contrast injection into the duct(on-table cholangiogram), or postopera-tively if a T-tube is in place (T-tubecholangiogram; Fig. 7.5).

Hepatic metastases

The liver is the most common metastaticsite after regional lymph nodes. Colon,stomach, pancreas, breast and lung arethe leading primary sites. The mostcommon clinical presentations are hep-atomegaly, jaundice and ascites. Liverfunction tests are often normal and accu-rate imaging is essential in diagnosis,treatment and follow-up.

The characteristics of metastases mayneed to be differentiated from other diseases of the liver and a carefulimaging strategy is needed, usually formulated following discussion with aradiologist.

AXR

Look for hepatomegaly, ascites andpunctate amorphous calcifications,


which may occur in colloid carcinomametastases (stomach, colon). Do remem-ber to request a CXR also in suspectedmetastatic disease.

US

This is the initial investigation of choiceand is accurate in identifying focal liverlesions. Metastases have varying sono-graphical appearances (Fig. 7.6).

CT

CT is frequently used for further evalua-

tion of focal lesions and if US is non-diagnostic (Fig. 7.7). US and CT can bothbe used to guide percutaneous biopsy ofa lesion to obtain histological confirma-tion of the diagnosis (Table 7.1). Hepa-tocellular carcinoma and lymphoma mayboth appear similar to metastasis andtreatment options differ — if clinicallyappropriate, histological examinationshould always be performed.

Certain liver metastases may betreated with image-guided ablation tech-niques or surgical resection. If these arecontemplated then further imaging —either CT angiography and portography

Fig. 7.4 T2-weighted MRCP image demonstrating a gallstone in the distal commonbile duct, seen as a low signal filling defect (long arrow). Note normal gall bladder(arrowhead) and duodenal loop (small arrows).

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Fig. 7.5 Normal T-tube cholangiogram study. Iodinated contrast is injected downthe T-tube (short white arrows) and opacifies the duct system and ampulla passinginto the duodenum (black arrow). The common bile duct is indicated by a longwhite arrow.


Fig. 7.6 US of the liver in a patient with known breast cancer. A focal hypoechoiclesion (callipers) is present in the right lobe of the liver, consistent with metastasis.

Table 7.1 Liver biopsy: CT- or US-guided.

Can be used to biopsyFocal lesionsDiffusely abnormal liver, but no focal lesionMacroscopically normal liver, but biochemical abnormality

ContraindicationsPatient unable to give informed consent or unable to cooperatePresence of ascites (can drain prior to procedure)Bleeding diathesis (prolonged prothrombin or activated partial thromboplastin time, platelet count

< 100 000/mL). Discuss with haematology and radiology departments. It may still be possible tobiopsy with covering transfusion with fresh frozen plasma or platelets. Blind biopsy can beperformed via transjugular route if severe clotting derangement

Patient preparationNil by mouthIntravenous accessConsentCheck full blood count, coagulation profile, group and save

ComplicationsMinor ache or shoulder discomfort is common post-procedureHaemorrhage (rarely significant), or bile leak (rare)Pneumothorax

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(CTAP), or MR would be performed toexclude other lesions. CTAP involvesdirect iodinated contrast injection via acatheter placed into the hepatic, splenicor superior mesenteric artery and thenimaging the liver.

Hepatic abscess

Pyogenic liver abscess can arise from fivemain routes:

1 Biliary (obstructed duct system,stones) — the most common cause2 Portal venous (bowel inflammation)3 Hepatic arterial (septicaemia)4 Direct extension from adjacent organ5 Traumatic penetrating injury.

Escherichia coli and streptococci arethe main causative organisms in adults.Abscesses are usually multiple and pre-senting features may be vague. Tenderhepatomegaly and deranged liver func-tion tests are common.

Fig. 7.7 Post-contrast CT of the liver in a patient with colonic carcinoma. The livercontains multiple hypodense metastases.


CXR

This is often abnormal. Look for eleva-tion of right hemidiaphragm, right basalatelectasis or pleural effusion.

AXR

Look for gas or air–fluid level overlyingthe liver.

US

US is highly sensitive and demonstrateshypoechoic lesions down to 1–1.5cm andmay identify foci of air within abscesses.However, US is not specific, and differen-tial diagnosis includes necrotic tumours,haematoma, complex cyst or biloma.

CT

This is the most accurate modality. Ab-scesses appear rounded and hypodense,often with an enhancing rim. Air withinabscesses may be seen and multiple smallabscesses may cluster into a larger lesion(Fig. 7.8).

Interventional treatment

For small unilocular suspected ab-scesses, aspiration under CT or USguidance may suffice together with antibiotic therapy. Discuss with the radi-ologist. For larger or complex lesions,formal guided drainage is required (Fig.7.9), and large drains (up to 16 French)may be needed if pus is thick. Surgerymay be needed if catheter drainage failsor if there is associated fistula formation(biliary or colonic).

It is important to investigate for anunderlying cause of the abscess. Do not

forget to send samples to microbiology.It is often helpful to discuss the case witha microbiologist. Patient preparationand complications for abscess drainageare similar to those for liver biopsy inTable 7.1.

Cirrhosis

Alcohol is the most common cause ofliver cirrhosis, with viral hepatitis andbiliary cirrhosis the other more com-mon causes. Patients may present withvague upper abdominal symptoms, hepatomegaly or abnormal liver func-tion tests, or with complications ofthe disease (e.g. liver failure, portal hypertension, ascites, hepatocellularcarcinoma).

US

This is most commonly used for initialassessment. Many sonographical find-ings are non-specific but certain featuresare suggestive:• Small liver with nodular surface• Coarse texture• Evidence of portal hypertension(ascites, splenomegaly, varices)• Can guide ascitic tap or drainage.

CT

CT is useful for further evaluation (Fig. 7.10) and particularly for:• Poorly visualized liver or very coarseliver texture on US• Focal lesion(s) on US• Clinical or biochemical suspicion ofhepatocellular carcinoma.

Fig. 7.9 CT image of the abscess in the same patient as Fig. 7.8, following percuta-neous insertion of a pigtail drainage catheter (arrow).

Fig. 7.8 CT image through the liver in a patient with a pyogenic liver abscess. Thereis a large hypodense lesion (arrow) comprising multiple small abscesses clusteredtogether.


Pancreatitis

Acute pancreatitis

Alcohol and gallstone disease are the mostcommon aetiologies. Clinical findings areoften non-specific, but include varyingdegrees of abdominal pain, nausea andvomiting. Serum amylase measurementmay be helpful — although amylase can beelevated in other conditions includingperforated duodenal ulcer and may benormal in severe necrotizing pancreatitis.

What is the role of imaging?• To exclude other pathologies as causeof symptoms• To confirm diagnosis of acute pancreatitis• To evaluate the degree of pancreaticinjury and presence of complications(e.g. abscess).

AXR

Look for duodenal ileus (sentinel loop isan overlying dilated gas-filled small

Fig. 7.10 Axial post-contrast CT of the liver in a patient with cirrhosis. The caudatelobe is enlarged (large white arrow). The liver surface is irregular, the spleen is en-larged (black arrow) and varices are present (small white arrows).

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bowel loop) or, rarely, gas bubbles in apancreatic abscess.

CXR

Look for elevated hemidiaphragm, atelectasis or pleural effusion.

US

US is useful in patients with mild diseaseand those with a suspected gallstone aetiology.

US may demonstrate hypoechoicswelling of the gland and associated fluid

collections. However, US is limited,often by bowel gas, and CT is requiredfor more severe disease.

CT

This is the most useful test in clinicallysevere acute pancreatitis. It:• Assesses the gland (Fig. 7.11) and, bylack of contrast enhancement, can iden-tify areas of necrosis• Visualizes the retroperitoneum,mesentery and omentum• Accurately delineates associated fluidcollections, pseudocyst and abscess for-

Fig. 7.11 Post-contrast CT through the pancreatic body and tail in a patient withacute pancreatitis. The pancreas is enlarged and poorly defined (large white arrow),but enhances homogeneously. Note associated inflammatory changes in the adja-cent mesenteric fat (small white arrows) and normal gall bladder (black arrow).


mation (Fig. 7.12) and can be used toguide therapeutic aspiration or drainage.

Chronic pancreatitis

Alcohol is the major risk factor, and painradiating to the back with weight loss arethe most common symptoms. Diabetesand malabsorption develop in some patients.

AXR

Small irregular pancreatic calcificationsoccur in up to 50% of patients and arepathognomic (Fig. 7.13).

US

US can provide useful information con-cerning gland morphology, calcificationand duct dilatation but is often limitedbecause of technical factors. It maydemonstrate a pseudocyst.

CT

CT accurately delineates the gland andareas of atrophy, or focal enlargement.Focal enlargement can be difficult to dif-ferentiate from complicating carcinoma(2–3% of patients).

Glandular calcifications and pan-

Fig. 7.12 Post-contrast CT in a patient with a pancreatic abscess following acutepancreatitis. There is a fluid collection in relation to the pancreatic body and thiscontains bubbles of air (small arrows) suggestive of abscess formation. No normalpancreas is seen in this section.

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creatic duct dilatation are well demon-strated. Other complications of chronicpancreatitis are visualized (e.g. pseudo-aneurysm and splenic vein thrombosis).

ERCP and MRCP

ERCP and, more recently, MRCP arealso useful in the diagnosis of chronicpancreatitis. They demonstrate well thechanges of dilatation and stricturing thatinitially involve the side branches andlater the main pancreatic duct itself(Fig. 7.14).

Pancreatic carcinoma

Ductal adenocarcinoma is the mostcommon form and occurs usually in the pancreatic head. Presenting symp-toms of pancreatic carcinoma are often

non-specific but include pain radiat-ing to the back and weight loss. Patientswith tumours in the head may presentwith painless obstructive jaundice. Accurate imaging is required to deter-mine the presence and operability of atumour.

US

US is usually requested for initial assessment of epigastric pain or jaun-dice. It is accurate in evaluation of thebiliary tree, hepatic parenchyma andascites, and will often demonstrate apancreatic mass.

CT

CT, however, is the modality of choicefor suspected pancreatic malignancy. CTwill usually demonstrate the pancreatic

Fig. 7.13 AXR demonstrating pancreatic calcifications in a patient with chronicpancreatitis.


mass (Fig. 7.15) and features that make itunresectable:• Venous or arterial encasement bytumour• Invasion of local structures• Nodal or mesenteric involvement bytumour• Hepatic or lung metastases.

MR

MR has also proved useful in tumour de-tection and staging. Its use is generallyreserved for cases equivocal at CT.

ERCP

This is particularly useful when otherimaging modalities have demonstratedduct dilatation, but no definite cause(Fig. 7.16).

Histological confirmation of malig-nancy can be obtained by US- or CT-guided aspiration or biopsy of thepancreatic lesion if accessible, or atERCP.

Fig. 7.14 Image from a T2-weighted MRCP sequence. There is dilatation of thepancreatic duct (arrowhead), with clubbed dilated side-branches. A low signal cal-culus is seen in the pancreatic duct (large white arrow). Note normal common bileduct (small white arrows) and gall bladder (black arrow).

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Bile duct stricture

Patients may present with right upperquadrant pain, jaundice and symptomsof malignancy if a malignant aetiology.

Strictures may be:• Benign: iatrogenic is the mostcommon (e.g. post-laparoscopic cholecystectomy)• Malignant: cholangiocarcinoma, car-cinoma of gall bladder or pancreas, com-pression by adjacent nodes.

US

US is accurate in the evaluation of intra-hepatic and common bile duct dilata-

tion. It may also demonstrate focallesions relating to gall bladder, portahepatis or pancreas.

CT

CT is used for further assessment if USconfirms duct dilatation and/or sus-pected malignancy. As CT is not affectedby patient size or bowel gas, it often pro-vides additional information concerninglevel and cause of duct obstruction andnodal status.

ERCP and PTC

ERCP or percutaneous transhepaticcholangiography (PTC) often represent

Fig. 7.15 Post-contrast CT in a patient with pancreatic carcinoma. There is a largehypodense mass in the pancreatic tail (large black arrow). The splenic vein has beeninvaded and is not seen. Normal pancreatic head and body are indicated by smallblack arrows. Ascites is present (white arrow).


the next diagnostic and therapeutic step.PTC is useful if ERCP fails or whenpathology may be better treated percuta-neously (e.g. mass at hilum of liver). AtPTC the liver is punctured and a dilated

duct entered, often using US guidance.A drain can be passed via this route todecompress the biliary tree and throughit strictures can be traversed usingguidewires, dilated by balloon catheter,

Fig. 7.16 Image from an ERCP in a patient with ampullary carcinoma. CT confirmeddilated ducts, but no obvious cause. ERCP demonstrates a dilated common bileduct (small arrow) and a shouldered stricture at the ampulla (large arrow). Biopsyat ERCP confirmed carcinoma.

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or a stent deployed (Figs 7.17 & 7.18).Adequate patient preparation is essential(Table 7.1). Biliary leaks and sepsis are additional complications of PTC and antibiotic prophylaxis is usually indicated.

Abdominal trauma

Trauma is the most common cause ofdeath in young adults. Car accidents,falls and assault are the most frequent

Fig. 7.17 Image from a PTC in a patient with cholangiocarcinoma of the commonhepatic duct. Puncture needle is demonstrated (small arrow). There is dilatation ofthe intrahepatic ducts down to the confluence with a stricture seen involving theupper common bile duct (large arrow).


Fig. 7.18 A guidewire has been manipulated across the stricture and a catheter in-troduced with its tip in the duodenum (small arrow). A self-expanding metallicstent has been introduced to lie across the stricture —note stent ‘waisting’ (largearrow).

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causes of major blunt abdominal trauma.Clinical assessment of abdominaltrauma is often unreliable. Resuscitationand stabilization should be undertakenprior to imaging.

Radiography

The basic initial major trauma series ofradiographs includes films of chest, cer-vical spine, abdomen and pelvis. AXR isinsensitive in detecting free intra-abdominal fluid, but may demonstrateassociated fractures in pelvis, spine or ribs.

US

US has limitations in evaluation ofmajor abdominal trauma. Because of as-sociated wounds and fractures, bandag-ing, patient discomfort and often largeamounts of bowel gas, accurate visual-ization of intra-abdominal organs is fre-quently impossible. US will miss manyliver, splenic and renal injuries and mostpancreatic and bowel injuries.

US does detect free peritoneal fluidand can assess the presence of haemo-peritoneum in unstable patients,

Fig. 7.19 Post-contrast CT through the abdomen in a patient with traumaticsplenic rupture with only fragments of enhancing spleen identified (large arrows).Haemoperitoneum is present (small arrows). Streak image artefacts are secondaryto monitor leads.


reducing the need for diagnostic peri-toneal lavage.

In many cases, if the patient is unsta-ble with evidence of abdominal injury,peritoneal lavage will confirm haemo-peritoneum and the patient will transferto theatre.

CT

If patients can be haemodynamically sta-bilized, CT is the imaging modality ofchoice for assessment of the abdomenand pelvis. If patients are to be trans-ferred to CT then it is essential they arestable, with established venous accessand medical accompaniment.

Effective CT significantly reduces theincidence of negative laparotomy. It canalso provide reassurance where physicalexamination is difficult (e.g. coexistinghead trauma, intoxication).

CT accurately demonstrates haemo-peritoneum. CT also has a high degree of accuracy in visualizing hepatic,splenic and renal injuries. The extent of laceration and associated splenichaematoma can be graded (Fig. 7.19) and up to 50% of adults with splenicinjury avoid surgery. The majority of hepatic and renal injuries in haemo-dynamically stable patients are alsomanaged conservatively (Fig. 7.20). Inpatients treated non-operatively, CT is

Fig. 7.20 Post-contrast CT demonstrates a fractured right kidney post-trauma. Thekidney is fragmented (large arrows) but is perfused, suggesting the vascularpedicle is not damaged. Note extensive perirenal haematoma (small arrow).

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used for follow-up to confirm resolutionof haemoperitoneum and healing oflacerations.

CT can also diagnose injuries tomesentery and bowel. Free intraperi-toneal air, bowel wall thickening andfluid between bowel loops are signs ofbowel injury.

Other modalities

IVU and other contrast studies are rarelyindicated. Stable patients with micro-scopic haematuria only do not usuallyneed further investigation.

Angiography is rarely used but may beindicated in some cases of vascularinjury and coil embolization can be used

to treat active extravasation from adamaged vessel.

Further reading


Levine MS, Rubesin SE, Laufer I, eds.Double Contrast Gastrointestinal Radi-ology, 3rd edn. Philadelphia: Saun-ders, 2000.


This chapter covers:Common conditions• Benign disease: cysts, fibroaden-oma, inflammatory disease• Malignant diseaseCommon presentations in whichimaging can help• Patients with symptomatic breastdisease are those who present withabnormalities they have detectedthemselves. The NHS, as in manycountries, runs a breast screeningprogramme for women who areasymptomatic and the imagingtechniques are common to bothgroups• This section will relate to thesymptomatic breast• Most patients will present with alump or area of nodularity. Othersymptoms include breast pain(mastalgia) or nipple discharge• If clinical examination reveals anarea of concern, eg. lump, bloody (ie non-physiological) nipple dis-charge, asymmetric pain of recentonset, axillary adenopathy then thepatient should be referred forimaging• Preferably, patients will attend ajoint or multidisciplinary clinicwhere the surgeon, radiologist andpathologist work together to gain adiagnosis as quickly as possible

Imaging strategy

The two principal imaging modalitiesused in initial symptomatic breast as-sessment are mammography and US.Which modality is used depends on thepatient’s age and the problem to be in-vestigated. The two techniques are com-plementary and are often used together.

Patients often need to undergo fineneedle aspiration for cytology. It shouldbe recognized that this will interferewith the image appearances of a masslesion and make interpretation difficultif not impossible. However, delays in diagnosis should be avoided.

Mammography

This involves the use of ionizing radia-tion with radiographs of each breast per-formed in two planes: lateral oblique andcraniocaudal (obl or CC labels on thefilm). The equipment and film used arespecific to mammography and there is a small radiation dose. High-qualityimaging is essential to make reliable diagnoses. Do not rely on poor-qualityimages.

Because of the radiation dose, mam-mography is not used routinely in youngor pregnant patients and it may not betechnically feasible in the elderly, infirmor those with extreme breast tenderness(e.g. breast abscess).

Mammography is accurate at demon-strating mass lesions in the breast, can

Chapter 8: The breast

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130 CHAPTER 8

characterize them to some extent and isthe technique of choice for detection ofmalignant microcalcifications. The sen-sitivity of mammography is significantlyreduced in young women with denseglandular breasts.

US

US is non-invasive and does not involvethe use of ionizing radiation. It is notused as a screening tool but is used in areas of palpable abnormality, oftencomplementing mammography. It isuseful in further characterization ofopacities seen mammographically (cystor solid) and also a useful adjunct in themammographically dense breast wherefocal lesions may be obscured.

US is often the only imaging modalityutilized in young and pregnant patients.It is used to guide fine needle aspirationor core biopsy of breast lesions and toexamine the liver for metastatic spread.

Other modalities

NM

Scintigraphy is used as a second-line in-vestigation in some high-risk patients fordetection of additional malignant lesionsand for regional nodal assessment. Bonescintigraphy is valuable for patients withsuspected bony metastatic disease.

MR

MR is useful for implant assessment and assessment of possible tumour recurrence.

CT

CT is not used for primary diagnosis butis used widely for staging of malignantdisease and monitoring its progress.

Benign breast disease

Cysts

Cysts are a common cause of a palpablebreast lump. In young women, clinicalcysts may be aspirated in clinic and noimaging is required. Many patientsundergo mammography and US forfurther assessment.

Mammography may demonstrate acircumscribed opacity (Fig. 8.1). US isalmost 100% accurate in simple cystcharacterization (Fig. 8.2). Many cystsare complex, however, following instru-mentation or haemorrhage and requirefurther investigation (either by follow-up US or aspiration).

Fibroadenoma

Fibroadenoma is the most commonbenign breast tumour, usually occurringin young women.

US may be the only modality utilizedin patients < 30 years and will demon-strate a circumscribed solid nodule (Fig.8.3). US can guide aspiration or biopsyfor confirmation.

Mammography may demonstrate awell-circumscribed opacity and US isused for further characterization.

Breast inflammatory disease

Breast inflammatory disease usuallyoccurs postpartum, during lactation. US is useful if abscess formation is

THE BREAST 131

Fig. 8.1 Craniocaudal mammogram of the right breast in a patient with multiplecircumscribed breast opacities. These are consistent with cysts and US wouldconfirm this. For orientation of a craniocaudal mammogram, imagine you arelooking down at the breast towards the patient’s feet and radiographical markersare placed in the axilla (laterally).

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suspected clinically. Mammography isnot usually performed in acute inflamma-tion because of pain from compression.

Breast carcinoma

Ductal carcinoma is the most commonhistological subtype and may be pre-ceded by ductal carcinoma in situ(DCIS). DCIS may manifest itselfmammographically as ductal microcalci-fication (Fig. 8.4).

Carcinoma usually presents as a pal-pable lump in the symptomatic breast,although pain, bloody nipple discharge

or nipple rash (Paget’s disease) may alsooccur. Further evaluation includesmammography, usually US, and also fineneedle aspiration or biopsy.

Mammography

Mammographical features to look for are(Fig. 8.5):• Ill-defined or spiculated mass• Parenchymal distortion• Overlying skin thickening• Malignant microcalcifications• Enlarged axillary lymph nodes.

Fig. 8.2 US features of a simple breast cyst: a thin-walled anechoic structure withassociated distal acoustic enhancement (arrows) caused by through-transmissionof sound through fluid.

THE BREAST 133

US

US features to look for are (Fig. 8.6):• Ill-defined, usually hypoechoic mass• Distal acoustic shadowing (caused bysound distortion and diffraction bytumour)• Surrounding halo — caused by oe-dema or tumour infiltration• Abnormal axillary nodes.

Metastases

CXR is used in initial staging for lung orrib metastases. In patients with aggres-sive tumours at risk of metastases orthose with clinical evidence of meta-static disease, further investigation is indicated. This will concentrate on theliver (US or CT) and bones (X-ray of af-fected area and bone scintigraphy). MRcan be useful in patients with equivocalbone scintigraphy.

Fig. 8.3 US of a fibroadenoma: an elliptical circumscribed solid nodule (blackarrow). Note distal acoustic enhancement and underlying pectoral muscle (whitearrow).

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Fig. 8.4 Left craniocaudal mammogram of DCIS: extensive malignant-type calcifi-cations are seen within the outer breast. They are branching (following ducts) anddiffer in size, shape and density. This patient is young; note how dense the breastparenchyma is.

THE BREAST 135

Fig. 8.5 Right lateral oblique mammogram in an elderly patient with a large ductalcarcinoma. This mass is ill-defined and spicules extend widely into the surroundingbreast. The spicules can relate to tumour infiltration or inflammation. The breastgenerally is far more lucent than the patient in Fig. 8.4; fatty replacement of denseglandular tissue is occurring. Some benign calcifications are also present in thebreast.

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Further reading

Feig SA, ed. Radiological Clinics of NorthAmerica: Breast Imaging 2000; Vol. 38(4).

Howlett DC, Marchbank NDP, AllanSM. Sonographic assessment of thesymptomatic breast. Journal of Diag-nostic Radiography and Imaging 2003;5: 1–10.

Fig. 8.6 US of breast carcinoma. There is an ill-defined hypoechoic solid mass (cal-lipers). Note hyperechoic halo surrounding (small white arrows). There is somedistal acoustic shadowing (large white arrow).

This chapter covers:Common conditions• Osteoarthritis, rheumatoid ar-thritis, gout• Metastases, myeloma• The cervical spine: trauma andrheumatoid arthritis• Osteoporosis• Colles’ fracture, femoral neckfractures• Infection: osteomyelitis, septicarthritis• Other conditions: diabetic foot,Paget’s diseaseCommon presentations in whichimaging can help• Pain: most musculoskeletal conditions• Swelling: often in joints• Sepsis: septic arthritis, osteomyelitis• Systemic illness (e.g. weight loss,malaise): metastatic disease, mye-loma, rheumatoid arthritis

Imaging strategy

With the wide range of imaging mo-dalities available, all of which can givevaluable information, a rational evidence-based approach to imaging iscrucial.

Radiography

The plain radiograph should be the firstinvestigation in most circumstances.

Correctly positioned radiographs in twoorthogonal planes are desirable, particu-larly in trauma: these are usually an APview and a lateral projection. Inclusionof the entire anatomical part and the relevant joints will help to avoid misseddiagnoses. Do not forget referred painand paraesthesiae! Comparison withprevious radiographs is often extremelyhelpful in evaluating the significance ofthe imaging findings. Plain film findings in musculoskeletal disorders are oftensubtle, and liaison with a radiologist willhelp to focus the imaging pathway foreach individual patient.

NM

NM is often utilized early in the investi-gation of musculoskeletal conditions,with a particular role in the evaluation ofsuspected metastatic disease, infectionand occult fractures.

CT

CT is used for further assessment ofsome fractures, particularly in the cervi-cal region, and can also be used to guidebone biopsy procedures.

MR

MR is an excellent modality for non-invasive imaging of bones, joints and softtissues generally. It is extremely useful ina problem-solving role. In general, CT isgood for looking at bone changes,

Chapter 9: Musculoskeletal system

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whereas MR is more sensitive in demon-strating soft-tissue changes and excessfluid (e.g. in joints).

US

US is useful at evaluating superficial softtissues and tendons, and also for demon-strating and aspirating joint effusions.

Osteoarthritis

This is the most common disorder of thejoints in the adult. It is more common inweight-bearing joints, but all the jointsmay be affected. Cartilage breakdown isthe underlying pathological process.

The general radiological appearancesinclude (Fig. 9.1):• Loss of joint space as a result of break-down in the joint cartilage. This tends to be greatest in the areas exposed to the greatest load and therefore may beasymmetrical. • Subchondral bony sclerosis occurs asnew bone formation develops.• Osteophyte formation at the marginsof the joint is seen.• Subchondral cysts or geodes form atareas of stress on articular cartilage andsubchondral bone.

The radiological features at specificjoints are as follow:• The hands and feet:

– More frequent in older patients andmuch more common in women– Metacarpophalangeal and car-pometacarpal joint of the thumb and the carpal joints of the radial side of the carpus are very commonlyaffected– Distal interphalangeal joint osteo-phytosis in the hands is clinically de-

scribed as Heberden’s nodes andwithin the proximal interphalangealjoints is called Bouchard’s nodes– Metatarsophalangeal joint of thegreat toe is commonly involved.

• The knee:– The most commonly involved joint– Medial tibiofemoral and patel-lofemoral compartments are mostcommonly involved, which can lead to varus deformity– Osteophyte formation leads topeaking of the tibial spines– Bony fragments may be present asloose bodies.

• The hip (Fig. 9.1):– Joint space narrowing is most oftenseen superiorly within the joint, withsuperior and lateral displacement ofthe femoral head– Cortical thickening or buttressingof the femoral neck may be seen.

• The spine:– Degenerative change at the inser-tion of the annulus fibrosus leads to osteophyte formation along themargins of the vertebral end plates,which may extend to the adjacent endplate — bridging osteophytosis– Loss of disc hydration within thenucleus pulposus leads to loss of discheight– Degenerative change can be seenwithin the apophyseal joints and thecostovertebral joints with hyper-trophic osteophyte formation.

Rheumatoid arthritis

Rheumatoid arthritis is the mostcommon adult connective tissue disor-der. It is a symmetrical inflammatorypolyarthropathy with a predilection for

MUSCULOSKELETAL SYSTEM 139

the small joints of the hands and feet.Larger joints such as the shoulder, elbow,hip, knee and ankle can be affected.

Diagnostic criteria require at leastfour of the following to be present:

• Morning stiffness• Swelling of three or more joints, espe-cially the wrist, metatarsophalangeal orproximal interphalangeal joints, formore than 6 weeks

Fig. 9.1 This AP radiograph demonstrates degenerative change within the righthip joint. Osteophytosis (white arrow) with geode formation (black arrow) is notedwithin the right hip joint with loss of joint space medially.

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• Symmetrical swelling• Typical radiographical changes• Rheumatoid nodules• Positive rheumatoid factor.

Radiographs of the hands and feetshould be obtained in the first instance.In the hands and wrists, the changes arecommonly seen within metacarpopha-langeal joints, proximal interphalangealjoints, intercarpal joints, ulnar styloidand distal radio-ulnar joint. Themetatarsophalangeal joints and inter-

phalangeal joints of the feet are com-monly affected early in the disease.

The early plain film appearancesinclude (Fig. 9.2):• Fusiform periarticular soft-tissueswelling (joint effusion)• Periarticular, then diffuse osteopenia• Widened joint space• Marginal bone erosions• Erosion of ulnar styloid.

The later plain film appearancesinclude:

Fig. 9.2 This AP radiograph of the left hand demonstrates periarticular osteopeniaat the metacarpophalangeal joints with periarticular erosive changes in associa-tion (white arrows). Note erosive and secondary degenerative changes alsopresent in the corpus with erosion of the ulnar styloid process.


• Diffuse loss of joint space from carti-lage loss• Flexion and extension contractionswith ulnar subluxation and dislocation• Marked destruction of the articularsurface of joints• Destruction of bone ends.

CXR may demonstrate resorption ofdistal ends of clavicles with upward dis-placement of humeral heads resultingfrom tear or atrophy of the supraspina-tous muscle and tendon. Pulmonarysoft-tissue masses (rheumatoid nodules)may be seen on the plain film. The pelvicradiograph may demonstrate protusioacetabuli with migration of the femoralhead into the acetabulum and ileum.Atlanto-axial subluxation within the cervical spine is important to recognize(see later in this chapter).

Useful differentiating features ofrheumatoid arthritis from otherarthropathies are:• The erosive changes in rheumatoidarthritis are rarely associated with hy-pertrophic bone changes such as sclero-sis, spurs or periosteal reaction• The distribution is symmetrical withdiffuse uniform cartilage loss• Erosive changes are most severewithin the hands and feet• Involvement of larger joints is late inthe disease process• The thoracic and lumbar spine areusually spared• Sclerosis of the sacroiliac joints witherosions is rarely found.

Gout

Primary gout is an inborn error ofpurine metabolism associated with hy-peruricaemia and recurrent episodes of acute arthritis. Men are much more

commonly affected than women. Sec-ondary gout is associated with myelopro-liferative disorders and their treatment,blood dyscrasias and chronic renalfailure.

The affected joint is acutely painful,hot and swollen. This is classicallywithin the metatarsophalangeal joint ofthe great toe. The plain film demon-strates soft-tissue swelling and joint ef-fusion. The main differential diagnosisis acute septic arthritis.

Chronic tophaceous gout occurs 5–10 years after the first initial attack.This develops in half of the patientswith recurrent acute gout. Early treatment may delay the development ofbony lesions.

The plain film appearances of chronictophaceous gout include (Fig. 9.3):• Nodular deposition of calcium mono-sodium urate crystals (tophi) may bewithin the synovium, subchondral bone(Fig. 9.3), helix of the ear and soft tissuesof the hand, elbow, foot, knee andforearm. These may calcify.• Chondrocalcinosis, especially withinthe soft tissues of the knee.• Bony erosions (Fig. 9.3) may be intra-articular, periarticular or distant fromthe joint.• The classic X-ray appearance is of around or oval erosion with scleroticmargins and an overhanging margin ofbone (Fig. 9.3).

Important differentiating featuresfrom other arthropathies:• Gout is asymmetrical• There is little or no osteopenia untillate in the disease• The joint space is preserved until late.

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Fig. 9.3 This radiograph demonstrates a rounded soft-tissue mass overlying themetatarsophalangeal joint of the great toe (white arrow). There is a well-definederosion of the head of the metatarsal of the great toe, with sclerotic overhangingmargins characteristic of gouty arthropathy (black arrow).


Skeletal metastases

Carcinomatous metastases are by far themost common malignancy of the skele-ton. The clinical presentation is of bonypain or pathological fracture. Metastasisshould always be considered in sympto-matic patients with a known history ofprimary tumour. Fracture secondary tominimal trauma should also raise thesuspicion of pathological fracture. Mostmetastases to bone are osteolytic. Sclerotic or mixed appearances do occurbut less commonly. Sclerosis afterchemotherapy is recognized.

Lytic metastases

These most commonly arise from car-cinoma of the breast, bronchus, kidney,uterus and gastrointestinal tract, but donot forget lymphoma. The site of in-volvement may vary but the axial skele-ton, the spine, skull, pelvis and proximallong bones are most commonly affected.If you encounter metastasis in thesmaller bones, then think of carcinomaof the bronchus, breast and kidney first.

The radiological features of lyticmetastases are:• They are often multiple.• They have poorly defined marginswithin the medulla of bone. (Evaluationof the margin of a lytic lesion on theplain radiograph is extremely useful in deciding whether it is a benign or malignant lesion — if in doubt, ask a radiologist).• Lytic lesions after chemotherapy orradiotherapy may become sclerotic. Acareful history is therefore important.• Ill-defined cortical destruction withextension into the soft tissues.

• Bony expansion is unusual but may beseen in carcinoma of the kidney andthyroid (Fig. 9.4).

Pathological fracture should always beconsidered when:• There is a history of a known carcinoma• The fracture margins are ill definedand irregular• The underlying medullary and corti-cal bone demonstrates ill-defined lyticlesions or destructive changes• The trauma was minimal.

Sclerotic metastases

Prostatic carcinoma is the most commoncause (see Chapter 11, Fig. 11.13), butcarcinoma of the breast, gastrointestinaltract, bladder and cervix may producesclerotic metastasis.

Radiological appearances on the plainfilm include:• Patchy sclerosis with loss of thenormal corticomedullary appearances• Extension through the cortex with ill-defined periosteal reaction• Some lytic destructive elements• Comparison with previous films andcareful history may help in differentiatingPaget’s disease from sclerotic metastasis.

Some important things toremember in the radiologicalassessment of metastases

• The initial plain X-ray obtainedmay be normal.• In cases of strong clinical concern,especially in patients with knownprimary tumour, further evaluationwith isotope bone scanning should beundertaken (Fig. 9.5). This has a sig-nificantly higher sensitivity than plainradiography.

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Myeloma

Myeloma is the most common primarymalignant bone neoplasm in adults andrepresents a malignant proliferation ofplasma cells.

Clinical features include:• Peak incidence range is 50–80 years ofage

• Twice as common in males• Presentation with bone pain in60–70% of cases• Anaemia, which is normochromic andnormocytic• Bence Jones proteinaemia with mono-clonal gammopathy• Hypercalcaemia• Renal insufficiency.

Radiological features on the plain filmare:• Small well-defined ‘punched-out’ lyticlesions: throughout the skeleton, ofteninvolving the skull (Fig. 9.6)• Generalized osteopenia: this maymimic osteoporosis, but generalized osteopenia in men in their fifties andsixties should raise suspicion of myelomaas osteoporosis in this group is rare• Pathological fracture: this affects halfof these patients and is most commonly avertebral compression fracture.

Fig. 9.4 This is a lateral radiograph of the right foot in a patient with metastaticrenal cell carcinoma. There is a large and ill-defined lytic lesion in the calcaneumalso involving adjacent talus and cuboid. Complete destruction of the inferior cal-caneal cortex can be seen. There is a pathological fracture of the neck of the taluswith ill-defined margins in keeping with pathological fracture (arrow).

• An MR examination may be a betteralternative in patients with suspectedspinal metastasis, especially if there iscoexistent degenerative change withinthe spine, and should be considered incases with neurological manifestationscombined with spinal pain.• MRI is helpful in patients with os-teoporosis and vertebral crush frac-tures with suspected spinal metastasis.• A radiologist’s opinion is valuable.


Fig. 9.5 Whole body isotope bone scan demonstrating multiple pathological areasof isotope uptake throughout the skeleton in keeping with disseminated skeletalmetastases.

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Sclerosis may be seen within lesionsafter radiotherapy. Isotope bone scanmay be negative in 25–50% of lesions asthese do not demonstrate increasedisotope uptake.

The cervical spine

Cervical spine radiographs are routinelyperformed as part of a trauma series andinitial immobilization of the cervicalspine is essential. The cervical spineshould not be mobilized until radiologi-cal and clinical evaluation has excluded afracture. Cervical spine films are also re-quested for the investigation of neck

pain and for symptoms referred to thearms and legs.

The number of radiographical viewsobtained in trauma depends on thepatient’s condition. The single most im-portant projection is the lateral view.Ensure all seven cervical bodies are visu-alized and the C7/T1 junction is seen(fracture dislocation may occur at thislevel). If the patient’s condition permits,an AP view and an open mouth odontoidview should be obtained. If the entirecervical spine with C7/T1 junction isnot visualized then ask the radiographerwhether a ‘swimmer’s view’ is possible,considering the patient’s condition. Thealternative is a CT scan of the non-

Fig. 9.6 Multiple ‘punched out’ lytic lesions can be seen throughout the calvarium,which are typical of myelomatous bony involvement.


visualized cervical spine. If a fracture isdemonstrated on plain radiographs thenCT may be indicated for further evalua-tion. Patients with associated neurologi-cal abnormalities may need to beevaluated with MR. Ask a radiologist.

In viewing the lateral radiograph ofthe cervical spine, it is important toassess the bony structures and to assessthe alignment of the vertebral bodies.Each vertebral body together with itsposterior elements should be evaluatedcarefully. Loss of vertebral body height,depression of the vertebral end plates ordiscontinuity in the cortical outline ofthe vertebral bodies and the posterior el-ements may indicate fracture. Normally,the intervertebral discs are symmetricalin appearance, without loss of height orlocalized asymmetrical widening or nar-rowing. Following trauma, assessment ofalignment and articulation is critical.The relationship of the various struc-tures can be assessed using anatomicallandmarks and imaginary ‘lines’ super-imposed on the lateral radiograph.These are demonstrated in Fig. 9.7. If indoubt, seek the view of a radiologist.

Acute cervical spine trauma

A full and complete description of allpossible cervical fractures and trauma isbeyond the scope of this chapter. A briefreview of the main types of fracture thatmay be encountered is presented. Thecrucial thing is to decide whether a fracture is stable or unstable. Unstablefractures may require urgent surgical intervention and specialist referral is essential. If there is any clinical doubt, then it is always wise to seek anexperienced specialist opinion as soon aspossible.

The classification of cervical fracturesis related to the mechanism of injury.The patterns of injury include hyper-flexion, hyperextension, vertical com-pression, flexion–rotation and lateralflexion (shearing) injuries.

Hyperflexion injury

These are the most common injuries of the cervical spine, including the‘whiplash injury’. These are usually associated with ligamentous disruptionof the posterior ligaments.• Flexion ‘teardrop’ fracture:

– Unstable.– There is often severe neurologicaldeficit below the level of fracture asso-ciated with quadriplegia.– Lateral view demonstrates local-ized flexion of the cervical spine witha bony fragment (‘teardrop’) repre-senting a fracture of the antero-inferior part of the vertebral body.Vertebral body subluxation andwidening of the facet joints is associated.

• Simple wedge fracture and clay shov-eller’s fracture (Fig. 9.8): fractures of thespinous process, most commonly C6/7or T1 are stable.• Anterior subluxation: may be stableinitially but can become unstable as a result of incomplete ligamentoushealing. Look for forward vertebral bodysubluxation associated with localizedforward flexion.• Bilateral facetal dislocation: an unsta-ble injury associated with forward verte-bral body subluxation and dislocation ofboth facet joints of the affected vertebralbody.

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Fig. 9.7 Normal lateral cervical spine radiograph. The ‘imaginary’ lines are demonstrated.1 The anterior longitudinal line joins the anterior margins of the junction of thespinous process and lamina.2 The posterior longitudinal line runs along the posterior vertebral bodies.3 The spinous line connects the tips of the spinous processes.4 The spinolaminar line joins the anterior margins of the junction of the spinousprocess and lamina.5 The posterior pillar line connects the posterior surface of the articular pillars.The laminar space lies between the spinolaminar line (4) and the posterior pillarline (5).


Fig. 9.8 Lateral view of the cervical spine with visualization of the cervical spinedown to C7/T1. There is a fracture of the spinous process of C7 (arrow). This is calleda clay shoveller’s fracture.

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Hyperextension injury

• The ‘hangman’s fracture’: an unstablefracture of both neural arches of C2 associated with prevertebral soft-tissueswelling, forward slip of C2 on C3 and fracture of the antero-inferior tip ofC2.• ‘Teardrop’ fracture associated with ex-tension: an unstable injury involving a fracture of the antero-inferior tip of the effected vertebral body, usuallyC2.

Vertical compression injury

• Jefferson fracture (Fig. 9.9a,b): an un-stable injury with fractures of the anteri-or and posterior arches of C1. This iscaused by axial force applied to the skullwith impaction of the occipital condylesonto the lateral masses of C1. An AP oropen mouth view may demonstratelateral displacement of the lateral massesof C1.• Burst fracture: caused by an axial forcecausing impaction of the intervertebraldisc into the vertebral end plate belowwith a comminuted fracture of the verte-bral body below. Fracture fragments maydisplace into the spinal canal. CT ishelpful in demonstrating these.

The cervical spine inrheumatoid arthritis

The atlanto-axial joint is the mostcommon site of rheumatoid involvementwithin the spine. Atlanto-axial subluxa-tion occurs in up to 6% of patients withrheumatoid arthritis and is demonstrat-ed as an increase in distance between theposterior surface of the anterior arch ofC1 and the anterior surface of the dens of> 2.5 mm (Fig. 9.10).

This is important in the preoperativeassessment of the rheumatoid patient as cervical spine extension associatedwith intubation may lead to cord compression.

Passive flexion and extension viewsmay be helpful as increasing atlanto-axial space on flexion may indicateatlanto-axial instability.

On the radiographs:• Look for subluxation of the odontoidon the flexion view• Look for erosions of the odontoid pegresulting from synovitis of adjacentbursae• Remember that the combination oferosion and osteopenia predisposes tofracture of the odontoid peg• Involvement of the apophyseal jointsand disc spaces may occur leading to ver-tebral body subluxations and bone destruction• Involvement of the cervical inteverte-bral discs may lead to disc narrowing andeventual fusion.

Osteoporosis

Osteoporosis is defined as the reductionof overall bone mass. This is a commonmetabolic disorder in postmenopausalwomen and the elderly. Other rarercauses of osteoporosis include:• Drugs: steroids and heparin• Metabolic conditions: Cushing’sdisease, hyperthyroidism, hyper-parathyroidism, hypogonadism,acromegaly, diabetes mellitus and pregnancy• Alcoholism• Chronic liver disease• Anaemia.

Fig. 9.9 (a) Lateral cervical spine radiograph of a patient involved in a road trafficaccident demonstrates fracture of the base of the dens with forward subluxationof C2 in relation to C1 (black arrow). In addition, there is a fracture of the lamina ofC1 (white arrow). (b) Axial CT image of C1 demonstrating fractures of the anterior(short white arrow) and posterior arch of C1 (long white arrows).

a

b

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Confirmation of the diagnosis of os-teoporosis and follow-up after treatmentis most commonly undertaken with dualX-ray absorptiometry (DEXA scanning).

Postmenopausal osteoporosis

Women in the range 50–65 years ofage are affected. Excessive loss oftrabecular bone occurs, giving rise to

rapid bone loss after the menopause.There is an increased incidence of frac-tures especially the vertebra and distalradius.

Plain film appearances in the spine(Fig. 9.11):• Radiographs negative until bone lossof 30%• Decreased overall bone density (osteopenia)

Fig. 9.10 Lateral cervical spine radiograph of a patient with rheumatoid arthritisdemonstrates widening of the atlanto-axial space (arrows). Note significant osteo-penia within the cervical spine with degenerative changes at multiple levels.


Fig. 9.11 This lateral radiograph of the thoracic spine demonstrates loss of verte-bral body height and anterior wedging of several of the thoracic vertebral bodies.This is typical of osteoporotic vertebral body collapse and crush fracture. The bonesare generally osteopenic. Note the dense cortical outline of the vertebral bodiesdemonstrating the typical ‘pencilling in’ appearance (white arrows).

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• Thinning and loss of the secondaryhorizontal trabecula, with an apparentincrease in the primary vertical trabecu-lae, with subsequent vertical striationappearance to the vertebral body• The cortices appear thin but dense inrelation to the trabecular changes, givinga ‘pencilling in’ appearance• Leads to loss of vertebral body height.

Senile osteoporosis

This affects elderly males and females ina ratio of 1 : 2, without having associatedaccelerated postmenopausal bone loss.There is an increased risk of fractures,most commonly in the femoral neck,proximal humerus, tibia and pelvis. Theweakened bones may fracture after onlyminor trauma.

Insufficiency fractures occur fromnormal stress on the abnormally weakbones and most commonly affect thesacrum, iliac bones and os pubis. Thesemay not be seen on X-ray. Insufficiencyfractures should be suspected in patientswith osteoporosis who develop sacral orposterior pelvic pain without a history oftrauma. Sacral insufficiency fractureshave a characteristic H-shaped patternof increased isotope uptake on bonescanning. This may help to exclude bonymetastasis as the cause.

Other common fractures

Colles’ fracture

Colles’ fracture is the most commonfracture of the forearm and is commonin the elderly. It is caused by a fall ontothe outstretched hand. Inadequate re-duction can lead to post-traumatic

arthritis and decreased function. Thereis distal radial fracture, often with a frac-ture of the ulnar styloid. Dorsal dis-placement of the distal fragment givesrise to the ‘dinner-fork’ deformity.

Plain film appearances are demon-strated in Fig. 9.12.

Fractures of the femoral neck

These are very common and sometimesundiagnosed fractures that occur inelderly patients, particularly womenwith osteopenia. Any fracture of thefemoral neck may lead to disruption ofblood supply and to subsequent avascu-lar necrosis of the femoral head.

The following types occur:• Subcapital fracture: at the base of thefemoral head. This has a significant inci-dence of subsequent avascular necrosisof the femoral head.• Transcervical fracture: occurs half waybetween the femoral head and the in-tertrochanteric line (Fig. 9.13).• Supratrochanteric fracture: occurs justabove the intertrochanteric line.• Intertrochanteric fracture: occursbetween the greater and lessertrochanter of the femur.

Osteomyelitis

Osteomyelitis commonly presents withpain, soft-tissue swelling and erythema,inability to weight bear and elevatedhaematological markers of infectionsuch as a raised white cell count, ery-throcyte sedimentation rate (ESR) andC-reactive protein (CRP). Osteomyelitisusually arises from haematogenousspread or from direct contamination inpenetrating injuries. The metaphysis of


Fig. 9.12 AP and lateral view of the right wrist demonstrates Colles’ fracture of thedistal radius with angulation.

Fig. 9.13 This AP radiograph of both hip joints demonstrates a transcervical frac-ture of the left neck of femur.

long bones of the lower limbs, vertebrae(lumbar spine is most common) andsacroiliac joints are the most frequentsites of involvement, although small tubular bones in the hands and

feet may be affected in diabetes. Diabetes is a significant predisposingcondition.

Radiological appearances on plainfilm:

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Fig. 9.14 This AP radiograph of the left tibia and fibula demonstrates increaseddensity of the upper tibia with associated periosteal reaction (white arrows) in apatient with osteomyelitis.


Fig. 9.15 This is a coronal STIR image of the same patient as in Fig. 9.14 (seeChapter 2), which demonstrates extensive marrow high signal (marrow oedemachange) within the proximal shaft of the tibia, extending to involve the proximaltibial metaphysis and the lateral aspect of the tibial epiphysis. This MRI examina-tion demonstrates the full extent of involvement.

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• Initial radiographs are often normal.• Early radiological signs are those ofsoft-tissue swelling and loss of fat planesat 7–10 days.• Periosteal reaction is usually seen after2 weeks (Fig. 9.14).• Ill-defined lytic lesions extend fromthe metaphysis as infection tracks intothe marrow cavity.• Late signs are areas of detachednecrotic cortical bone forming sequestra.These appear as sclerotic areas of bone.• Pus may extend into the soft tissues.• Joint involvement is more common inadults than children.• Left untreated, chronic osteomyelitis,which is characterized by areas of densesclerotic bone with thickening associatedwith lucent areas and periosteal reaction,may develop.

Isotope bone scanning and white celllabelled scanning may be used to detectearly osteomyelitis, with a sensitivity of80–90%.

MRI is very sensitive in the early detection of acute osteomyelitis and,unlike NM, does not involve a radiationdose to the patient. The typical featuresof osteomyelitis on MRI include (Fig.9.15):• Low signal intensity within themarrow on T1-weighted images withhigh signal intensity on T2-weightedand STIR images (see Chapter 2).• High signal halo surrounding thecortex on T2-weighted images• Demonstration of bony and soft-tissue abscesses and tracts.

Septic arthritis

Patients with septic arthritis presentwith a painful, swollen and hot joint with

a septic clinical and haematologicalpicture. The hip and knee joints are mostcommonly involved in children, with theshoulder, sternoclavicular joint, spine,sacroiliac joint and symphysis pubismost common in adults.

Modes of infection:• Haematogenous spread — particularlyin intravenous drug abusers and im-munocompromised patients• As a complication of internal fixationor joint prosthesis• As a result of direct penetrating injury• Spread from adjacent osteomyelitis

Staphylococcus aureus (includingMRSA) is the most common organismisolated.

Plain film appearances (Fig. 9.16):• Early signs:

– Radiographs are initially normal inmany cases– Soft-tissue swelling with joint effusion.

• Later signs: after 1–2 weeks– Small ill-defined bony erosionswith loss of cortical outline– Subchondral bony destruction– Areas of reactive sclerosis withinthe underlying bone.Early diagnosis and treatment is im-

perative to avoid permanent joint de-struction and ankylosis. US of the hip ishelpful in confirming a joint effusionand for guiding aspiration.

The diagnosis is made by obtainingblood cultures and prompt joint aspiratefor Gram staining and culture. Radiolog-ical guidance is helpful in aspiration ofthe hip joint, sacroiliac joint and withinthe spine.

Depending on availability, an isotopebone scan or MR is helpful in cases ofclinical doubt.


Diabetic foot

The diabetic foot is caused by a combina-tion of loss of sensation and propriocep-tion of the affected limb, combined withrepetitive trauma. The most commonsites affected are the ankle, foot andhand. The clinical presentation is that ofa swollen joint, often with deformity,without history of significant trauma, incombination with peripheral neuropa-thy and loss of proprioception.

The radiological features include(Fig. 9.17):• Joint effusions in association withsoft-tissue swelling.• Hypertrophic sclerosis of the joints.This affects the subchondral bone andmay be rather patchy.• Atrophic changes with areas of

bone resorption, leading to areas oflucency.• Advanced degenerative changes withbony fragmentation. Subluxation ofjoints commonly within the mid foot(Charcot’s joint).• Vascular calcification is commonlyseen.• There may be evidence of previousamputation, especially in the feet.

Diagnostic difficulty occurs as many of the above signs also occur with infection. Infection in the feet is a common complication of diabetesand may coexist with the changes basedon the peripheral neuropathy describedabove.

It is important to look for:• Soft-tissue swelling, with obliterationof the normal fat planes.• Soft-tissue emphysema seen as small

Fig. 9.16 AP radiograph of both hip joints. This patient was involved in a roadtraffic accident. The patient developed fever with right hip pain. This radiographdemonstrates bilateral internal femoral fixation. There is, in addition, loss of jointspace within the right hip joint in comparison with the left, with ill-defined lytic de-struction of the acetabular cortex (arrow). The appearances are suspicious forseptic arthritis. Aspiration and culture was positive.

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Fig. 9.17 This AP radiograph of the foot demonstrates subluxation of the tar-sometatarsal joints of the second, third, fourth and fifth toes (black arrows), withfractures of the bases of the second and third metatarsals, with ill-defined lucencycombined with callus formation. Sclerotic change is noted within the middle andlateral cuneiforms (small white arrows) with vascular calcification (large whitearrow) present. The appearances are in keeping with diabetes and Charcot’s joint.


focal lucencies within the soft tissues.These may be associated with an ulcer,but if the tissue planes distant to an ulcerare affected you must think about anaer-obic infection and whether urgent actionis required.• Ill-defined lytic cortical destruction,as this is suggestive of osteomyelitis.• Periosteal reaction in the absence offracture.

Comparison with any previous radio-graphs allows assessment of disease progression and is useful for the subtlechanges of early osteomyelitis. A follow-up radiograph after a short interval, with comparison to the initial radio-graph, will help in the detection of earlyinfection.

Isotope scanning and MR are ex-tremely useful in the detection of earlyosteomyelitis and in the evaluation of theextent of involvement.

Paget’s disease

British radiologists love Paget’s diseaseas it is uncommon outside WesternEurope and has easily recognized radio-logical features. It is characterized by disordered and exaggerated bone remodelling. It affects the middle-agedand elderly, with increased incidence inmen. Geographically common withinthe UK, it also occurs in Australia, NewZealand and the USA. The axial skele-

Fig. 9.18 AP radiograph of the pelvis demonstrates cortical thickening (blackarrow) within the left hemipelvis, with coarsening of the trabeculae and patchysclerosis (white arrow) typical for Paget’s disease.

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ton is the most common site of involve-ment, affecting the spine (75%), skull(65%), pelvis (40%; Fig. 9.18) and prox-imal femur (75%).

Ask a radiologist to show you his orher collection! The main point here isthat it should not be mistaken for sclero-tic metastases, particularly in the pelvisfrom the prostate, or vice versa. Ingeneral, it runs a benign course.

Isotope bone scans are useful in assessing the areas of involvementwithin the skeleton and this distributionhelps to differentiate metastases and can be used in the assessment of diseaseactivity.

Complications of Paget’s disease

• Sarcomatous change and fractures: if

pain occurs in a patient with Paget’sdisease, think of sarcomatous change —rare, up to 1% of patients overall — andinsufficiency fractures of long bones andvertebral compression fractures.• Premature osteoarthritis and deformity:from bowing of long bones and protrusioacetabuli.• Neurological complications: occur inadvanced cases due to bone softeningand remodelling causing nerve entrap-ment and cord compression. This maylead to basilar impression and obstruc-tive hydrocephalus.

Further reading

Sutton D, ed. A Textbook of Radiologyand Imaging, 7th edn. Wangstone,UK: Churchill, 2002.

This chapter covers:Common conditions• Thyroid: benign nodule, goitre,malignancy, thyroiditis• Salivary gland: sialolithiasis,sialadenitis, tumour• Cervical adenopathyCommon presentations in whichimaging can help• Palpable mass: thyroid or salivarygland neoplasm, cervical node• Pain with or without swelling: thy-roid or salivary gland malignancy,thyroiditis, sialadenitis• Systemic illness: metastatic thy-roid or salivary gland malignancy,thyroid dysfunction, malignantadenopathy

Imaging strategy

US

US is the initial imaging technique for the investigation of neck diseases. It is readily available, inexpensive, non-invasive and does not involve ionizing radiation. It quickly and accurately distinguishes solid from cystic lesions,can identify additional non-palpablenodules and can be used to guide fineneedle aspiration cytology (FNAC). The thyroid, parotid and submandibularglands, and cervical lymph nodes are superficial in location and are readily accessible to high-resolution US exam-ination. US has high accuracy in the

detection of salivary gland calculi, associ-ated ductal dilatation and complicationssuch as abscess or sialocele formation. Itis effective in salivary gland tumour lo-calization, although it may not be able todelineate the entire extent of very largeor deep tumours. US is the first-line investigation of choice in the evaluationof cervical lymphadenopathy, with highsensitivity and specificity, especiallywhen combined with FNAC.

Conventional sialography

Conventional sialography is an invasiveprocedure that involves duct cannulation,contrast injection and irradiation. It maybe required to demonstrate very smallcalculi, ductal strictures and sialectasis.

It is increasingly being replaced by USand MR sialography, which providenon-invasive assessment of ductal obstruction.

NM

NM provides functional imaging thatcomplements morphological imaging. Itis useful:• To determine whether a focal thyroidnodule or mass is a ‘hot nodule’ (low in-cidence of malignancy) or a ‘cold nodule’(high incidence of malignancy)• In hyperthyroidism to distinguishGraves’ disease (uniformly increased ra-dionuclide uptake) from toxic adenomaor toxic multinodular goitre (Plummer’sdisease)

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• Postoperatively in patients withthyroid cancer to search for residual localdisease and distant metastases• To identify ectopic thyroid tissue.

Medications such as propylthi-ouracil and iodine-containing contrastagents may temporarily interfere with the organification of iodine andshould be stopped for adequate periods of time before thyroid nuclearscintigraphy.

PET (see Chapter 2)

Lymphoma, primary malignant epithe-lial tumours and metastatic lym-phadenopathy show increased FDGuptake. PET is useful in whole bodystaging to determine locoregional extentof disease as well as the presence ofdistant metastasis. FDG-PET is not indicated in the primary diagnosis ofthyroid carcinomas but is useful indemonstrating recurrent or metastaticthyroid carcinoma in patients with increasing thyroglobulin levels but negative radio-iodine scans.

CT and MRI

CT and/or MRI is indicated in:• Thyroid malignancies:

– When the tumour is suspected tohave infiltrated into the surroundingstructures– To demonstrate cervical nodalmetastases and pulmonary metastases(CT)– For delineating the extent ofintrathoracic extension.

• Salivary glands:– In sialoadenitis to demonstratepresence and extent of complicationssuch as abscess formation (CT)

– Indicated for imaging very large or parotid deep lobe tumours (MRI)– Tumours arising from the deepspaces such as the parapharyngealspace that displace and/or invade thesalivary glands are also better demon-strated on CT and/or MRI– MRI is unsurpassed in its ability to demonstrate perineural tumourspread, classically by malignantparotid tumour retrogradely along thefacial nerve into the otomastoid cavity.

Thyroid

The thyroid is an endocrine organ. Diseases of the thyroid may present asfunctional disturbance in the form ofendocrinopathy (hyperthyroidism or hypothyroidism) or as morphologicalanomaly in the form of focal (thyroidnodule) or generalized (goitre) glandularenlargement. While the hormonal dis-turbance can be assessed by biochemi-cal assays, the evaluation of the struc-tural abnormality requires modernimaging techniques that provide high-resolution images of the anatomi-cal alterations.

The term ‘goitre’ simply means enlargement of the thyroid gland. It maybe caused by simple goitre (the mostcommon cause of which is Graves’disease) or the presence of multiplethyroid nodules (multinodular goitre). Itshould be remembered that the thyroidmay contain multiple nodules withoutbeing enlarged, in which case the moreappropriate term ‘multinodular thyroid’should be used.

The aims of imaging of the thyroidgland include:

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• To confirm the clinical suspicion of athyroid lesion and to determine thenature of the lesion if possible• When goitre is present to see ifthere is retrosternal or retroclavicularextension and to assess the mass effect onadjacent structures• To provide precise real-time guidancefor FNAC and biopsy• To follow-up patients after treatmentto exclude locoregional recurrence• To screen patients with increased riskof developing thyroid malignancies (e.g.patients with Hashimoto’s thyroiditis).

Imaging is not very accurate in differ-entiating benign from malignant thyroidnodules and in this respect FNAC is ofutmost importance in establishing thediagnosis.

Commonly encounteredthyroid pathologies

Multinodular thyroid

This is the most commonly encounteredcondition of the thyroid (80%), with apredilection for females. Most patientsare asymptomatic, but occasionally maypresent with pressure symptoms from arapidly enlarging thyroid mass, usuallythe result of acute haemorrhage withinthe nodule.• US: hyperplastic nodules are mostcommonly isoechoic with well-definedmargins; cystic components are presentin 60% and may be caused by colloid orhaemorrhage (Fig. 10.1)• NM: demonstrates multiple hot andcold nodules; toxic nodules will show in-creased uptake while suppressing therest of the gland.

Graves’ disease (diffuse toxic goitre)

This is the most common cause ofhyperthyroidism, with a femalepredilection. Patients may have associated thyroid ophthalmopathy, andbiochemistry demonstrates elevated T3and T4, suppressed thyroid-stimulatinghormone (TSH) and positive anti-TSHreceptor antibody.• US: diffusely enlarged gland withheterogeneously hypoechoic, markedlyvascular parenchyma• NM: uniformly markedly increaseduptake relative to background.

Thyroid malignancy

Papillary carcinoma

This is the most common thyroid malig-nancy (60–90%), with a female predilec-tion. Risk factors include exposure to external radiation (especially in childhood), excessive iodine intake, autoimmune thyroid disease, geneticsyndromes such as Gardner’s andCowden’s syndromes.

Lymph node metastases occur in > 50% of patients at the time of diagno-sis. Distant metastases to lung and boneoccur in 5–7% of cases. Prognosis is ex-cellent despite the high incidence of in-traglandular and lymph node metastases.• US: papillary carcinomas are usuallyhypoechoic and ill-defined with irregu-lar margins. Punctate microcalcificationis highly specific for papillary tumours(Fig. 10.2). US is valuable in the follow-up of patients who had undergone thy-roidectomy for papillary carcinoma.

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Follicular lesion

A follicular carcinoma can only be dis-tinguished from a follicular adenoma bythe demonstration of capsular and vas-cular invasion on histological examina-tion of the entire specimen and the term

‘follicular lesion’ is thus adopted, whichusually implies the need for surgical excision.

Follicular carcinoma accounts for2–5% of all thyroid malignancies andmostly develops from a pre-existingadenoma. It tends to develop distant

Fig. 10.1 US image of a large complex hyperplastic nodule replacing much of thethyroid right lobe. This lesion contains cystic and solid components. Some normalthyroid tissue is seen posteriorly (black arrows).

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haematogenous metastases to the lung,liver, bone and brain, with nodal meta-stases relatively uncommon.• US: follicular carcinomas are largelysolid, usually homogeneously hyper-echoic lesions and calcification is rare.

Anaplastic carcinoma

This represents 15–20% of all thyroidmalignancies with a very aggressive clin-ical course. There is a predilection forelderly females. It usually presents as arapidly enlarging thyroid mass causingpressure symptoms. Eighty per centhave a long pre-existing history of goitre.• US: large ill-defined hypoechoicmasses replacing the entire lobe are seen.

Adjacent vascular invasion, extracapsularspread and nodal or distant metastasesare often present.

Medullary carcinoma

This is uncommon (5% of all thyroidcancers). Medullary carcinoma originates from the calcitonin-producingparafollicular C cells and is associatedwith multiple endocrine neoplasia(MEN) types 2A and 2B, and C-cell hyperplasia. Nodal metastases arepresent in 50% at initial presentation,and distant metastases to lung, liver andbone in 15–25%. There is a high recur-rence rate, which may be detected by arising serum calcitonin level.

Fig. 10.2 Longitudinal US image of the left lobe of the thyroid in a patient withpapillary carcinoma. There is a hypoechoic mass that has poorly defined marginsidentified and this contains internal fine punctate microcalcifications (whitearrows), which represent calcified psammoma bodies.

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• US: solid hypoechoic nodules, withechogenic foci representing denseamyloid deposits and associated focalcalcifications in 80–90%. Multiple ordiffuse involvement of both thyroidlobes is almost always seen in the familialform, which has a poor prognosis.

Thyroid lymphoma

Uncommon (1–3% of all thyroid malig-nancies). Non-Hodgkin’s lymphoma ismore common in the thyroid and isalmost invariably preceded by a historyof Hashimoto’s thyroiditis. There is apredilection for elderly females. Thyroidlymphoma commonly presents as arapidly enlarging neck mass.• US: focal lymphomatous nodules andadjacent cervical nodes may show a‘pseudocystic’ appearance with pos-terior acoustic enhancement. Rememberthyroid lymphoma does not take uppertechnetate or iodine but is FDG avid.

Thyroiditis

Hashimoto’s thyroiditis (autoimmunechronic lymphocytic thyroiditis) is themost common chronic thyroiditis andusually affects middle aged females whopresent with an often tender goitre andhypothyroidism. Patients are at risk oflymphoma development in particular.

Antibodies against thyroid- and non-thyroid-related proteins serve asthe basis of serological diagnosis.• US: may be helpful in gland assess-ment. An atrophic shrunken thyroidmay result.

Salivary glands

Salivary gland diseases usually presentclinically as palpable focal or diffuse enlargement. Physical examination oftencannot be certain of the exact origin andnature of the palpated lesion andimaging is required to aid in the diagnosis and treatment planning.

Inflammation and neoplasm are thetwo most common aetiologies of salivarygland diseases. The aim of imaging inthe former group is to identify the cause(e.g. ductal obstruction resulting fromsialolithiasis) and complications (e.g.abscess formation), while in the lattergroup imaging is for tumour localizationand full extent delineation.

Sialolithiasis

Submandibular stones (80%) are morecommon than parotid stones because ofthe higher mucus content of the salivaproduced by the submandibular gland.Ninety per cent of submandibularstones are radio-opaque but only 10% ofparotid ductal stones are radio-opaque.

Ultrasound is the first-line investiga-tion of choice for the detection of sali-vary gland stones with high sensitivity,specificity and accuracy (Fig. 10.3).Plain X-rays can be helpful, especiallyfor calculi near the salivary duct meati.

Inflammatory disease

Acute infection

Viral infection (mumps) is a commoncause of parotid swelling — imaging israrely needed. The parotid gland is also most commonly affected by acute

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suppurative sialadenitis, usually sec-ondary to ductal obstruction fromsialolithiasis or retrograde entry oforal cavity bacteria. Painful regionaladenopathy is often present.• US: the acutely inflamed gland is enlarged with decreased echogenicity.Abscess appears as an ill-defined hypo-echoic lesion, sometimes with frank liquefied pus content. Ultrasound-guided aspiration yields specimens forlaboratory identification of the culpritorganisms and helps in guiding the appropriate antibiotic therapy.

Chronic inflammatory conditions

These are caused by chronic sialolithia-sis or other pathology such as Sjögren’ssyndrome. US is used to confirm orexclude salivary gland involvement in

Sjögren’s syndrome and to screen forlymphomatous change in the cervicalnodes because patients with Sjögren’ssyndrome are at increased risk oflymphoma.

Salivary gland neoplasms

US is the initial imaging modality ofchoice, although US alone is not very ac-curate in differentiating benign frommalignant tumours. Diagnostic accuracycan be further improved by FNACunder US guidance.

Benign neoplasms

Pleomorphic adenoma

Pleomorphic adenoma is the mostcommon salivary gland neoplasm

Fig. 10.3 Sonographical features of submandibular sialolithiasis. There is intra-glandular ductal dilatation (small white arrows) and intraductal hyperechoic fociare present, consistent with calculi (large white arrow) with associated distalacoustic shadowing.

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(60–80%) and 90% arise from the super-ficial lobe.• US: homogeneous hypoechoic solidmasses, rounded or ovoid in shape withwell-defined lobulated margins and posterior acoustic enhancement (Fig.10.4)• CT/MR: can be helpful in delineat-ing large and/or deep lobe lesions orthose with atypical US features.

Warthin’s tumour

Warthin’s tumour (papillary cystaden-oma, cystadenolymphoma) accounts for6–10% of all salivary gland neoplasmsand occurs virtually exclusively in theparotid glands. It more commonlyaffects elderly men; 15–30% of cases arebilateral.• US: typically well-defined hypo-echoic lesions with complex internal

heterogeneity comprising of both solidand cystic components.

Malignant neoplasms

Tumours in the sublingual or sub-mandibular glands are more likely to be malignant than tumours in theparotid glands. Imaging features for all malignant tumours are similar and it is not possible to distinguishbetween the various histopathologicalsubtypes.

Low-grade malignant tumours mayappear as well-defined homogeneouslesions mimicking benign tumours;high-grade malignant tumours are morelikely to show ill-defined infiltrativemargins and heterogeneous internal architecture on all modalities (Fig. 10.5).Cervical and lung metastases may bepresent.

Fig. 10.4 US appearances of a parotid pleomorphic adenoma. There is a rounded,hypoechoic and homogeneous solid mass identified (white arrow) with distalacoustic enhancement.

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Fig. 10.5 Post-contrast axial T1-weighted MR image that demonstrates an ill-defined enhancing mass replacing the superficial and deep lobes of the leftparotid gland (white arrow). Biopsy confirmed this to represent a mucoepidermoidcarcinoma.

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Mucoepidermoid carcinoma, adenoidcystic carcinoma and acinic cell carcin-oma are the main subtypes, with meta-stases and non-Hodgkin’s lymphomaalso occasionally identified within thesalivary glands.

Cervical lymph nodes

Evaluation of the neck nodal status con-stitutes an important and integral part

of a complete examination for manyhead and neck diseases. The neck nodalstatus carries prognostic informationand guides the selection of therapy in patients suffering from head and neckcancers. Imaging contributes most sig-nificantly to identifying cervical nodalmetastatic disease in those patients withno clinically palpable disease (N0). Cervical lymph nodes are also commonsites of involvement by lymphoma andtuberculous infection.

Fig. 10.6 Doppler ultrasound of a normal lymph node. This has an elliptical shape with a central hyperechoic hilum (white arrow) and there is central hilar vascularity.

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US

US represents the initial imaging modality of choice for a suspected enlarged cervical node.

Normal cervical nodes appear flat orelliptical, with an echogenic fatty hilumand a hypoechoic cortex (Fig. 10.6). Malignant nodes tend to be more ovoid,

hypoechoic and hypervascular, with lossor displacement of the normal fattyhilum (Fig. 10.7). Metastatic cervicallymphadenopathy follows the pattern of lymphatic drainage and tends to be site-specific, which may serve as thehint in localizing unknown primarytumours.

Fig. 10.7 Colour Doppler US of a node involved by metastatic carcinoma. Thislesion is rounded and of heterogeneous internal architecture with prominent internal necrosis (white arrow). There is predominantly peripheral and chaotic vascularity consistent with metastatic infiltration.

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CT and MR

These are used for formal nodal stagingin carcinoma and lymphoma (Fig. 10.8).They will not detect metastasis innormal-sized nodes and not all enlargednodes are malignant. PET may behelpful in some cases.

Further reading

Ahuja AT, Evans R, eds. Practical Head and Neck Ultrasound. London:Greenwich Medical Media, 2000.

Fig. 10.8 Post-contrast coronal T1-weighted MR image through the posterior neckdemonstrating metastatic right-sided cervical adenopathy (white arrows), follow-ing the lymphatic drainage from a primary nasopharyngeal carcinoma.

This chapter covers:Common conditions• Kidney: renal failure, obstruc-tion, calculus disease, cyst disease,infection, renal cell carcinoma andinfection• Ureter and bladder: calculus, obstruction, tumour• Prostate: carcinoma• Testis: tumour, acute scrotumCommon presentations in whichimaging can help• Haematuria: calculus disease,urogenital tract tumour• Urinary tract infection: calculusdisease, obstruction• Loin pain: tumour, infection,colic from calculus or clot• Abdominal mass: renal orbladder tumour, renal cyst• Renal failure: imaging is particu-larly useful in demonstrating ob-struction as a cause, and delineatinglevel and aetiology• Testicular mass: tumour• Testicular pain: torsion, tumour,varicocoele, epididymo-orchitis, referred from kidney

Imaging strategy

US

US is the workhorse of uroradiologicalinvestigation. It is the primary tool in assessment of renal masses, tumours orcysts and for the symptomatic scrotum.In the assessment of renal failure, USshould be performed to exclude a post-renal (obstructive) cause for thispresentation. US is often combined withAXR as the initial investigation ofhaematuria.

AXR

AXR is particularly useful in demon-strating renal tract calcification, whetheras calculi or in association with cysts andtumours.

IVU

IVU includes administration of intra-venous iodinated contrast (non-ionic)and hence is contraindicated in the pres-ence of renal impairment and iodineallergy. It is still an extremely useful investigation in suspected renal colic,and may be invaluable in the demonstra-tion of urothelial abnormality. IVU maybe performed as a second-line investiga-tion of haematuria if US or cystoscopy are unhelpful. Other contrast studies(e.g. cystogram, micturating cystogram,retrograde ureterogram) are usually performed as second-line investigations.

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175

Note:That cystoscopy is the primary modal-ity for investigation of the bladder

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CT

The primary urological function of CTis in the staging and follow-up ofprimary urogenital tract tumours. CThas a role in further evaluation of renalinfection and abscess, and also in theevaluation of complex renal cysts. Insome departments, unenhanced CT isused to investigate renal colic, allowinggood visualization of ureteric calculiwhile avoiding iodinated contrastmedium.

MRI

This may be helpful in local assessmentof bladder or prostatic carcinoma.

NM

NM is not used as a primary imagingmodality in renal tract disease.

Renal failure

US is the single most useful investiga-tion for assessment of patients with renalimpairment. It can demonstrate:• Normal kidneys (Fig. 11.1)• The presence of two kidneys• Hydronephrosis secondary to me-chanical obstruction• Small shrunken kidneys in chronicrenal failure• Renal or bladder calculi

Fig. 11.1 US of a normal right kidney (callipers) adjacent to right lobe of liver. Note normal renal cortex (small white arrow), which appears hypoechoic in rela-tion to hyperechoic renal sinus fat (large white arrow).

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• Bladder distension in bladder outflowobstruction.

Further imaging is usually reservedfor patients with suspected obstruction.

Urinary tract obstruction

Urinary tract obstruction may be unilat-eral or bilateral, and can occur at anylevel from the kidney to the urethra.

Causes include:• Kidney: stone, tumour, blood clot,pelviureteric junction (PUJ) obstruction• Ureter: stone, tumour, stricture, extrinsic compression or invasion (e.g.retroperitoneal fibrosis or tumour)• Bladder: tumour, stone, prostatic hy-pertrophy

• Urethra: stricture, congenital valves.

Acute presentation is often unilateral,with renal colic and pain from the affect-ed flank to the inguinal region. The mostcommon cause is an impacted renal cal-culus, but impaction of clot or a sloughedpapilla can give a similar presentation.

AXR

AXR is used to demonstrate radio-opaque calculi (90% are opaque).

US

US is used to demonstrate hydroneph-rosis (Fig. 11.2) and calculi. US is

Fig. 11.2 US image of a hydronephrotic kidney. Note the dilatation of the pelvi-calyceal system (large white arrow) and thinning of the renal cortex (small whitearrows). Cortical thinning suggests chronicity, secondary to prostatic hypertrophyin this case.

178 CHAPTER 11

accurate in detecting renal or bladdercalculi, but ureteric visualization in theretroperitoneum is usually limited.

IVU

IVU will give functional as well asanatomical information. It is frequentlythe only investigation performed in patients with suspected calculus colic(Fig. 11.3). Classically, the findings onIVU are:• Increasingly dense nephrogram• Delayed excretion of contrast topelvicalyceal system• Mild to moderate dilatation ofcollecting system and ureter to the levelof obstruction.

US and IVU will both demonstratedilated collecting systems and will alsodemonstrate the degree to which renalparenchyma has atrophied (Fig. 11.2).Remember, IVU is contraindicated withrenal impairment.

CT

CT is used in some departments in preference to IVU as it allows a quick location of calculus without the need for iodinated contrast. CT is of value inevaluating both the level and often thenature of the obstruction.

Chronic obstruction may be virtuallyasymptomatic. It may present during in-vestigation for other entities or as a resultof a complication such as infection of theobstructed system or deterioration inrenal function.

Urinary tract calcification

Urinary calculus

Most commonly formed of oxalate,calcium oxalate or phosphate, uric acidor cystine. A number of conditions predispose:• Urinary stasis (secondary to obstruction)• Urinary sepsis• Metabolic causes (e.g. hyperparathy-roidism, hypercalcaemia with hypercal-ciuria, gout).

Calculi are frequently discovered as an incidental finding. Presenting features include pain, haematuria or evidence of infection.

AXR

Plain film will show many calculi. Thereis a range of visibility extending from themost obvious staghorn calculus (Fig.11.4) to radiolucent uric acid calculus.Paradoxically, the latter may often havethe more dramatic presentation bycausing acute obstruction. FAXR shouldalways be performed prior to a contraststudy as valuable information aboutcalculi may be masked by the contrast(Fig. 11.5a,b).

US

US can show calculi within the kidney oroccasionally at the vesico-ureteric junc-tion. Demonstration of pelvicalyceal dilatation can be helpful in showing thatthere is obstruction.


IVU

IVU allows delineation of renal tractanatomy and its relationship to calculi

seen on plain film. Delayed excretioninto a dilated pelvicalyceal system orureter indicates the presence of obstruc-tion, and with time its level.

Fig. 11.3 A post-micturition film performed in an IVU series in a patient with rightrenal colic. This demonstrates mild right-sided pelvicalyceal dilatation with calyceal clubbing (large white arrows) and dilatation of the right ureter also downto the level of the vesico-ureteric junction (small white arrow). This was secondaryto a radiolucent calculus.

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CT

CT may be offered in some departmentsin place of IVU as it allows demonstra-tion of calculus without the need forcontrast agents.

CT will show high density of calculus,thus allowing distinction from urothelialtumour (where confusion could occurwith radiolucent calculus on IVU).

Fig. 11.4 AXR demonstrates bilateral renal calculi. The left-sided staghorn calculushas a configuration similar to the pelvicalyceal system that it fills. On the right sidethere is a large calculus lying in the renal pelvis and upper right ureter, with smallercalculi seen in the lower pole of the right kidney (arrows).


Fig. 11.5 (a) An image from IVU series post-contrast administration. This demon-strates right-sided pelvicalyceal dilatation although no definite cause is seen. (b) A control pre-injection radiograph in the same patient as (a) confirms the presenceof a large calculus at the pelviureteric junction that is causing obstruction (arrow).This was obscured on post-contrast images.

a

b

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Nephrocalcinosis

Cortical nephrocalcinosis

This is visible on AXR as calcificationpredominantly in the renal cortex.Causes are acute cortical necrosis,chronic glomerulonephritis and oxalosis.

Medullary nephrocalcinosis

This appears as grouped medullaryrounded and linear calcifications onAXR (Fig. 11.6). Causes are hyper-parathyroidism, renal tubular acidosis,medullary sponge kidney (Fig. 11.6) andhyperoxaluria.

Focal calcification

Calcification may occur in a renal massand may be malignant in 75% of cases.Causes include:

• Tumour• Infection: commonly tuberculous orxanthogranulomatous pyelonephritis• Cysts: secondary to haemorrhage orprevious infection.• Vascular.

Renal cyst disease

Simple cyst

This represents the most common renalmass lesion representing approximately60% of the total. The incidence of suchcysts increases with increasing age.These lesions are, by definition, simplewith a thin wall and containing onlyserous fluid. Simple cysts are most com-monly found incidentally while investi-gating other conditions. Occasionally,the cyst may become so large as to causeabdominal discomfort and a palpable

Fig. 11.6 AXR demonstrates clustered calcifications distributed within themedullary regions of the kidneys bilaterally (arrows) in a patient with medullarysponge kidney. In this condition there is cystic dilatation of the papillary andmedullary portions of the collecting ducts and calcifications may form within them.


mass. These cysts may also presentthrough complicating episodes of haem-orrhage or infection and, occasionally, alarge cyst may cause obstruction if it liesadjacent to the upper ureter and renalpelvis.

US

Simple cysts are frequently detected incidentally using US. US is also themodality of choice for cyst characteriza-tion (Fig. 11.7). Haemorrhage and/or

infection may cause debris in cysts,which can mimic tumour and follow-up is needed. If the cyst is demon-strated on US to be simple (thin-walled)with homogeneous fluid content andwell demarcated from the rest of thekidney then no further investigation isrequired.

IVU

A simple cyst, if large enough, may be demonstrated as a mass lesion. Its

Fig. 11.7 US of a simple renal cyst. This is thin-walled and anechoic and there isdistal acoustic enhancement.

184 CHAPTER 11

low density may give a clue as to itsnature.

CT and MR

CT and/or MR will clearly demonstratesimple cysts, which are often an inciden-tal finding on abdominal examinations,and may be used to further evaluate orfollow-up complex cysts.

Adult polycystic disease

There is autosomal dominant inheri-tance and therefore there is likely to be astrong family history. Cysts of varyingsizes are first present in early adulthoodand progress in those severely affected togive two large kidneys (which are often

palpable) that are largely cystic, eventu-ally leading to renal failure.

US is the best tool for initial as-sessment (Fig. 11.8) and monitoringprogress, but CT and MRI may beuseful in distinguishing haemorrhagic orinfected cysts from malignancy.

Urinary tract infection

Pyelonephritis

Acute pyelonephritis refers to acuteupper urinary tract infection, most oftenby pathogenic coliform bacteria thathave entered the lower urinary tract viathe urethra. As a result of longer urethraand antibacterial properties of prostatic

Fig. 11.8 US of a polycystic kidney. The renal substance is largely replaced by multiple cysts of varying sizes and the kidney is grossly enlarged.


secretions, males are far less frequentlyaffected than females.

Presentation is with:• Fever• Frequency• Flank pain• Dysuria• Bacteria and pus cells in urine.

Imaging

Imaging is not required for uncompli-cated cases. US and AXR may providefurther information when patient has:• Diabetes• Previous urinary calculi• Atypical organism• Poor response to treatment• Frequent recurrences.

Renal abscess

Diabetics are predisposed. Sepsis arisesfrom ascending, usually Gram negative,organisms in 80% of cases, withhaematogenous spread in 20%.

US

US will show a hypoechoic mass pro-gressing to an anechoic mass in laterstages, as a result of liquefaction, with anirregular margin to the lesion.

CT

CT shows focal necrotic mass with enhancement of thickened margins. Itmay be hard to differentiate fromtumour.

Emphysematous pyelonephritis

Emphysematous pyelonephritis is a

renal infection with gas-forming organisms, with a 40–50% mortality. Itoccurs in predisposed patients:• Immunocompromised, particularlydiabetics.• Those with obstructed kidney. Gas in the renal interstitial and perirenaltissues may be seen on AXR (Fig. 11.9)and CT.

Renal cell carcinoma

This tumour represents 80–90% of allrenal malignancy, with peak prevalenceseen in the sixth decade. Renal cell carcinoma is bilateral in 2% of patients.Bilateral and multicentric tumours arecommon in patients with von Hippel–Lindau syndrome.

Presentation is with:• Often an incidental CT or US findingduring the investigation of other symptoms• Local symptoms: haematuria, pain,mass• General: weight loss, fever, varico-coele (sudden appearance on left becauseof compression of left gonadal vein),anaemia, hypercalcaemia• Metastases (25% at presentation):bone pain, cough, haemoptysis.

AXR

AXR may show:• Calcification of renal mass• Bulge in renal contour• Pulmonary metastases• Bony metastases (may be expansile).

US

US of renal cell carcinoma can have

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Fig. 11.9 AXR in an elderly patient with emphysematous pyelonephritis. Note thepresence of air within the right renal substance (arrow).

variable appearances. Necrosis will giveareas of low echogenicity in the centre ofmany tumours, particularly the largerones. US is particularly helpful in

demonstrating extension of tumour tothe inferior vena cava (Fig. 11.10),which, if extensive, will significantlyaffect treatment planning.


CT

This is the most sensitive technique forfurther characterization of renal masses(Fig. 11.11) but also an essential tool inlocal staging and demonstration oflymph node spread. Evidence of renalvein extension may also be shown.

MRI

MRI has no definite role at present butmay be helpful in imaging patients withallergy to iodinated contrast.

IVU

IVU is of limited use as it demonstratesfeatures of mass lesion but does not distinguish it from renal cyst.

Angiography

Angiography is no longer part ofdiagnostic imaging strategy but may beused as part of tumour embolization forpalliation in those unsuitable for curativesurgery.

Fig. 11.10 Sagittal US of the inferior vena cava in a patient with renal cell car-cinoma, demonstrating hypoechoic tumour thrombus (white arrows) within theinferior vena cava. Note normal liver (white arrow head).

188 CHAPTER 11

Urothelial tumours

These tumours arise from the lining epithelium anywhere in the renal tract.Eighty per cent are transitional cell carcinomas (TCCs) and 15% are squa-mous cell carcinomas. They arise mostcommonly in the bladder and least fre-quently in the ureter.

TCC is associated with:• Exposure to aniline dyes• Tobacco• Cyclophosphamide therapy• Pelvic radiation.

Males are more commonly affected thanfemales in a ratio of 3 : 1.

Painless haematuria is the mostcommon presenting feature (in up to90% of cases). This finding may be associated with irritative symptoms of dysuria, urgency and frequency. Patients may also present with ob-struction and frequency without haematuria.

Most of these tumours arise in thebladder and so investigation and diagno-sis is largely the preserve of the cysto-scopist. Investigation is designed aroundthe causes of haematuria.

Fig. 11.11 Post-contrast CT of the kidneys demonstrates a left-sided renal cell car-cinoma. There is a mixed attenuation mass arising medially from the left kidney(arrow). Note central low attenuation consistent with necrosis.


AXR

Calcification may occasionally bedemonstrable encrusted onto the surfaceof the tumour or punctate within thelesion. Radio-opaque calculi will also bedemonstrated by this examination.

US

US is of value in detecting soft-tissuetumours of the upper urinary tract andwill also demonstrate evidence of ob-struction by tumour in the lower urinarytract. Bladder tumour may also bedemonstrated by US.

IVU

If the cause for haematuria remainselusive, IVU will allow visualization ofthe pelvicalyceal systems and ureters inthe search for filling defects suggestive ofTCC. Blood clots, however, can givesimilar appearances.

Retrograde pyelogram

This allows visualization of the pelvi-calyceal systems and ureters, as with theIVU, but is performed by instilling iod-inated contrast via ureteric cathetersplaced cystoscopically (Fig. 11.12).During fluoroscopy there is greatercontrol, allowing for more detailed examination which may be targeted atareas of uncertainty on the IVU. Brushbiopsy of suspicious filling defectsshould be possible if the uretericcatheter is left in place.

CT

CT is invaluable as a tool for the staging

of urothelial tumours, allowing assess-ment of local and distant metastaticspread. CT can be used to guide biopsyof enlarged lymph nodes in order toconfirm tumour involvement.

MRI

MRI can provide improved detail oflocal invasion, particularly in respect ofthe depth of muscle invasion by bladdertumour. Often, local staging will bebased on clinical or pathological groundsalone.

Squamous cell carcinoma

Squamous cell carcinoma is rare butoften found in association with chronicirritation of the epithelium, particularlyfrom calculi but also from schistosomia-sis. It has a poor prognosis as a result ofearly metastases.

Other causes

Other causes of a mass in the pelvi-calyceal system are as follows:• Uric acid calculi (radiolucent)• Vascular impressions• Tuberculosis• Pyeloureteritis cystica• Papillary necrosis (sloughed papilla)• Renal cell carcinoma extending intopelvicalyceal system• Metastases (e.g. melanoma).

Prostatic carcinoma

This is the most common of all urinarytract cancers, but frequently remainslatent and undiscovered. The tumourarises in the peripheral zone (70%)

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Fig. 11.12 Films from a right retrograde pyelogram study. Contrast has been in-jected into a catheter lying in the right ureter (large white arrow) introduced cys-toscopically. Note extensive irregular filling defects (small white arrows) within thepelvicalyceal system and ureter consistent with diffuse transitional cell carcinoma.


and almost all are adenocarcinoma (> 95%).

Presentation is with:• Prostatism• Haematuria• Bone pain from metastasis or patho-logical fracture• Renal failure secondary to obstructionby local infiltration of distal ureters.

The crucial issue is in determiningsuitability for radical treatment. Atpresent, this is done mainly on clinical,biochemical and histological grounds.

Radiography

X-rays demonstrate the sclerotic lesionsthat are characteristic of prostate secon-

daries in bone (Fig. 11.13) and alsopathological fractures.

US

Transabdominal and transrectal US canshow prostate carcinoma as a hypoechoiclesion, although a variety of appearancesare described. A significant number ofcancers cannot be demonstrated by US.US is a good tool for directing transrec-tal biopsy and will demonstrate uppertract obstruction.

CT

CT demonstrates gross local invasion ofadjacent structures and also evidence of

Fig. 11.13 Pelvic radiograph in a patient with metastatic prostate carcinoma. Thereare multiple sclerotic metastases present.

192 CHAPTER 11

distant spread such as lymph node enlargement. However, it cannot allowaccurate enough local staging to deter-mine suitability for radical treatment.

MRI

MRI gives better detail of local anatomyand therefore better local staging. Thereis controversy at present whether localstaging is accurate enough to allow deci-sions to be made for or against radicaltreatment.

NM

If prostate-specific antigen (PSA) issignificantly raised then isotope bone

scan allows a sensitive one-stop survey ofthe entire skeleton for bony deposits. Ifclinical suspicion for a targeted arearemains high in the face of negative bonescan, then MR is of value.

The testis

Testicular tumour

This is the most common tumour inmales between 25 and 35 years of age.Seminoma and teratoma are the mostcommon subtypes. Patients tend topresent with painless enlargement of atestis. Pain and/or hydrocoele may occurand occasionally patients present withsymptoms of metastatic disease.

Fig. 11.14 US of the testis in a patient with seminoma. There is a circumscribed hypoechoic mass in the lower pole of the testicle that was confirmed as a seminoma.


US

US is the required initial investigation.It is extremely sensitive in the detectionand characterization of testicular massesand also for differentiating intra- and ex-tratesticular lesions. The US features oftesticular tumours vary: seminoma fre-quently appears hypoechoic and solid(Fig. 11.14), with teratoma containingsolid, cystic and calcific components.

Recently, the phenomenon of testicu-lar microlithiasis has been revealed withhigh-resolution US equipment. This

represents tiny foci of microcalcificationin testicular tubules (Fig. 11.15) and isthought to be associated with the devel-opment of malignant tumour, especiallyseminoma.

CT

CT is used to stage malignant testiculartumours, demonstrating para-aorticlymphadenopathy and hepatic or pul-monary lesions. CT is used in combina-tion with tumour markers to monitorresponse to treatment.

Fig. 11.15 Testicular US in a patient with testicular microlithiasis. The testis is at-rophic, which may be related to previous inflammation, and in addition there aremultiple hyperechoic flecks seen throughout the testicular parenchyma. Such pa-tients need clinical and sonographic follow-up to exclude tumour development.

194 CHAPTER 11

The acute scrotum

Epididymo-orchitis

US is accurate in diagnosing acutescrotal inflammation and is helpful ifabscess formation is suspected.

Torsion

Torsion may have complex and confus-

ing appearances on US so if there is clinical concern about possible torsion,the scrotum should always be surgicallyexplored.

Further reading

Dahnert W, ed. Radiology ReviewManual, 5th edn. Philadelphia: Lippincott Williams & Wilkins, 2003.

This chapter covers:Common conditions involving thebrain and spine• Trauma• Cerebrovascular disease• Subarachnoid haemorrhage• Infection• Tumours• Multiple sclerosis• Cord compressionCommon presentations in whichimaging can help• Collapse: stroke, haemorrhage,trauma• Headache: haemorrhage, tumour,infection• Fit: tumour, infection, stroke,haemorrhage• Funny turn: transient ischaemicattack, tumour• Altered conscious level: trauma,infection, stroke, haemorrhage

Imaging strategy

Most patients with neurological symptoms and signs require cerebralimaging as part of their management,usually CT or MRI, or both. Plain X-rays rarely supply any additional information.

In the acute setting, usually followingtrauma or collapse, the patient must beresuscitated and stabilized first, beforeany imaging is considered. If the patientis agitated or confused, the anaesthetistmust be contacted early to intubate or

sedate the patient and communicationwith the radiologist is advised.

The decision as to which modality touse is dependent on a number of factors.Some of the advantages and disadvan-tages of CT and MRI are as follow.

Advantages of CT

• Fast• Usually available out of normalworking hours• Sensitive for detection of intracranialblood, and excellent bone detail.

Disadvantages of CT

• Involves ionizing radiation• Views of the posterior fossa are de-graded by artefact from skull base.

Advantages of MRI

• Multiplanar imaging ideal for accu-rate localization of a lesion• Wide coverage (e.g. whole spine can be imaged to identify level of cord compression)• No ionizing radiation• Very sensitive in detection of smalllesions and involvement of themeninges, cranial nerves and posteriorfossa.

Disadvantages of MRI

• Slow (relatively)• Images degraded by slight movement

Chapter 12: Central nervous system

195

196 CHAPTER 12

• Unsuitable for patients with pacemak-ers, recent surgery or claustrophobia (seeChapter 2)• Usually not available out of normalworking hours• Poor bony detail• Special equipment necessary forpatient ventilation and monitoring.

Good communication is essential. An ac-curate neurological assessment can assistgreatly in the selection of the most appropriate imaging modality to make a diagnosis. Similarly, the results mayrequire urgent action and the requestingclinician must be readily available toreceive and act on the imaging findings.

Trauma

Patients with major trauma often needresuscitation and stabilization beforeimaging. If there are multiple sites ofinjury, the full extent of imaging re-quired should be agreed before com-mencement. About one-third of patientswith significant brain injury do not havea skull fracture, and the presence of afracture does not necessarily indicate anassociated brain injury. Traditionally,UK practice has relied heavily on skullradiography, but this should now largelybe reserved for when CT is not availableor for suspected non-accidental injury.CT is advised in those patients wherebrain injury is suspected clinically.

CT

When intracranial haematoma or braininjury is suspected, CT is the best initialimaging modality. MRI may be appro-priate if the patient’s clinical and CT

appearances do not correlate and also toidentify small contusions and subtle abnormalities in the brainstem or poster-ior fossa. Patients who are fully orientatedand have no history of loss of conscious-ness do not require brain imaging.

National Institute for Clinical Excel-lence (NICE) guidelines for imagingadults with serious head injury are asfollow:• Glasgow coma score (GCS) < 13• Suspected open or depressed skullfracture• Any sign of basal skull fracture (e.g.cerebrospinal fluid [CSF] otorrhoea,racoon eyes, Battle’s sign)• Repeated vomiting• Post-traumatic seizure• Focal neurological deficit• Coagulopathy.Even if CT is normal, these patientsusually require admission and observation.

Extradural haematoma

Extradural haematomas (EDHs) aremost common in the fronto-parietalregion resulting from direct injury to themiddle meningeal artery, but can occurin the posterior fossa when the accumu-lation of blood occurs between the skulland the dura.

On CT, an EDH typically appears as abiconvex high-density lesion deep to theskull vault that is often fractured. Thereis usually considerable cerebral masseffect (Figs 12.1 & 12.2).

Patients with EDHs are often lucid forseveral hours after the trauma, but mayshow a rapid decline in their level of con-sciousness as the haematoma continuesto enlarge, causing mass effect and cerebral herniation.

CENTRAL NERVOUS SYSTEM 197

Fig. 12.1 CT shows a left-sided extradural haematoma. Note the biconvex shape,mass effect and effacement of the temporal and anterior horns of the left lateralventricle.

198 CHAPTER 12

Fig. 12.2 CT using a bone window setting in the same patient as Fig. 12.1 demon-strates the left temporal bone fracture (arrow).


Subdural haematoma

There is usually a history of head traumabut this may be relatively minor, espe-cially in elderly or alcoholic patients.Most patients with a subduralhaematoma (SDH) have a neurologicaldeficit, personality change or alteredconsciousness level. The accumulationof blood in SDH occurs between thedura and arachnoid mater and is causedby the tearing of bridging veins.

An acute SDH is shown as a crescenticrather than biconcave area of increaseddensity on CT, most commonly in theparietal region. The density of thehaematoma on CT imaging decreaseswith time. After the initial bleed, bloodappears hyperdense, becoming the samedensity (isodense) as adjacent brain after2 weeks, and after 3 weeks it is of lowerdensity than brain. A chronic SDH isoften the same density as CSF (Fig. 12.3).

Acute-on-chronic SDHs are not uncommon in alcoholics and show bloodof different densities according to age(Fig. 12.3).

Cerebrovascular disease

Cerebral infarction

Cerebrovascular accident (CVA) orstroke are terms given to an underlyingcerebrovascular disorder usually causedby atherosclerosis, thrombosis, em-bolism, hypoperfusion, vasculitis orvenous stasis. CT is usually used in theinitial assessment to identify cerebralhaemorrhage or underlying vascularmalformations and tumours that maymimic stroke symptoms. If an infarct(and no bleed) is present, the patient

is usually commenced on aspirin oranother form of anticoagulation.

An abnormality is usually seen on CTafter 24 hours following onset of symp-toms in patients with cerebral infarcts.These are usually areas of low density affecting both white and grey matter in a vascular distribution (Fig. 12.4). CT scans performed earlier are oftennormal. MRI is more sensitive than CTat early infarct detection, but these patients are usually agitated and areunable to lie still enough in the acutesetting. MRI is useful for identifyingbrainstem and posterior fossa infarcts thatmay not be well demonstrated on CT.

Twenty to 25% of large infarctsbecome haemorrhagic infarcts, usuallybetween 24–48 hours after the ischaemicevent and these show areas of increaseddensity within the area of infarction.

Transient ischaemic attack

Patients with transient ischaemic attacks(TIAs; neurological symptoms or signsresolved in < 24 hours), or those whohave made good neurological improve-ment following a cerebral infarction,should also undergo a carotid duplex ultrasound scan if they are consideredsuitable candidates for surgical treat-ment of their arteries (e.g. carotid endarterectomy). Although there is noage limit, the risks of surgery in patientsolder than 85 years often exceed benefit.The duplex scan identifies plaqueswithin the internal and common carotidarteries causing areas of stenosis or narrowing. At the site of stenosis, the velocity of the blood flow in the vessel increases in proportion to the degree ofnarrowing and the amount of stenosiscan be calculated (Figs 12.5 & 12.6).

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Fig. 12.3 CT of a patient with a right-sided intraventricular shunt (white arrow).Note the low-density right-sided chronic SDH (long black arrow) and the acute onchronic left-sided SDH. This is shown as a mixed increased and low-density areasuggesting an acute bleed into an existing chronic SDH. A focus of acute haemor-rhage is present (small black arrow).


Fig. 12.4 CT scan shows a large infarct in the right middle cerebral artery territory.This is a low-density defect involving both white and grey matter. There is associated mass effect with the right lateral ventricle partially effaced (arrow) and there is minor mid line shift to the left.

Fig. 12.5 Left carotid artery US scan showing large atherosclerotic plaques (arrows)at the origin of the internal carotid artery (ICA). The external carotid artery (ECA)and bifurcation (BIF) are also annotated.

Fig. 12.6 Colour duplex carotid US in the same patient as Fig. 12.5 confirms significant ICA narrowing secondary to the plaque with flow turbulence (arrows).


Intracerebral haematoma

Hypertensive haemorrhage is the mostcommon cause of spontaneous intra-cerebral haematoma. Patients com-monly present with similar symptomsand signs to a cerebral infarct, withsudden-onset neurological deficit, possi-bly with altered conscious level, depend-

ing upon the size and amount of masseffect of the bleed. Patients are frequent-ly agitated or confused and may requiresedation or intubation prior to imaging.

Most intracerebral haemorrhagesoccur within the cerebral hemispheres,especially within the basal ganglia, but20% occur in the brainstem or cerebel-lum. CT demonstrates a well-definedarea of high density (Fig. 12.7).

Fig. 12.7 Unenhanced CT scan demonstrates an acute left temporal lobe haematoma.

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Cerebellar haematomas can be amenableto neurosurgical evacuation so urgentconsultation with a neurosurgeon maybe appropriate.

Subarachnoid haemorrhage

Patients with subarachnoid haemor-rhage (SAH) typically present withsevere sudden-onset headache, fre-quently occipital. Ninety per cent ofnon-traumatic SAHs are caused by rup-tured berry aneurysms. In order of fre-quency, these arise from the:• Posterior communicating artery• Anterior communicating artery• Middle cerebral artery• Internal carotid artery• Tip of the basilar artery.Other causes include arteriovenous (AV)malformations, hypertensive haemor-rhage, anticoagulation therapy and trauma.

CT

CT is indicated, particularly if thepatient has a deteriorating or fluctuatingconsciousness level or a neurologicaldeficit. Patients may require sedation or intubation if they are confused or agitated prior to imaging.

CT will demonstrate a SAH in ap-proximately 80% of cases. The normallow-density CSF is replaced by high-density blood in the basal cisternsand/or sulci (Fig. 12.8).

Patients with normal CT scans and noclinical signs of raised intracranial pres-sure should undergo lumbar puncture todemonstrate xanthochromia and makethe diagnosis of SAH.

Hydrocephalus that is acute obstruc-tive (occurring within 1 week) or delayedcommunicating (occurring after 1 week),cerebral vasospasm and infarction, and

transtentorial herniation are recognizedcomplications.

Urgent contact with a neurosurgicalcentre is advised once the diagnosis ismade. The patient may undergo cerebralangiography to identify the cause, embolization or surgical clipping ofthe aneurysm and intraventricular shuntinsertion if there is hydrocephalus.

MRA

MRA may sometimes be useful indemonstrating the aneurysm (Fig. 12.9);however, small aneurysms are not alwaysdetected.

Cerebral infection

Meningitis

Patients with suspected meningitispresent acutely, are usually unwell,febrile and have signs of meningism suchas neck stiffness and photophobia. If apatient has the following clinical signs,CT is indicated to exclude the presenceof a cerebral abscess:• Altered or fluctuating consciousnesslevel or mental state• Seizures• Papilloedema • Focal neurological deficit.

These patients are usually extremelyunwell and may be agitated, often requiring sedation or intubation prior tothe CT scan. Early communication witha senior colleague and anaesthetist isadvised.

A normal CT scan does not excludethe presence of raised intracranial pressure as this can be present in patientswho have a normal CT.

Patients with acute onset of symp-


toms and signs of raised intracranialpressure should not undergo lumbarpuncture, even in the event of having anormal CT scan.

A CT scan is not indicated for patientswith suspected meningitis with no

clinical signs of raised intracranial pressure, prior to lumbar puncture.

Cerebral abscess

These are usually caused by pyogenic

Fig. 12.8 Unenhanced CT scan shows extensive subarachnoid blood in basal cisterns (long arrows), the sylvian fissures (short arrows) and within sulci.

206 CHAPTER 12

bacteria that reach the brain by directspread from an open skull fracture orsurgery; from localized infection such asmeningitis, mastoiditis or sinusitis; orfrom a distant focus such as bacterial endocarditis or sepsis.

In the emergency setting, CT isusually the investigation of choice.These patients are usually extremelyunwell and may be agitated, requiringsedation or intubation prior to the CTscan. Early communication with a senior colleague, an anaesthetist and a radiologist is advised.

CT

On CT, a cerebral abscess is usually anarea of low density in the affected white

matter, with surrounding low-densityoedema and mass effect. When intra-venous contrast is administered, there isusually peripheral or ring enhancement(Fig. 12.10). There may be fluid andbone destruction in adjacent sinuses ormastoid air cells. The main radiologicaldifferential diagnosis includes primaryor secondary cerebral tumour.

MRI

MRI with gadolinium enhancement is more sensitive for early detection ofcerebral infection and meningeal in-volvement; however, the patient needs to be able to lie completely still in order to obtain images of diagnosticquality.

Fig. 12.9 MRA shows a posterior view of the circle of Willis with an aneurysmarising from the right posterior communicating artery (long white arrow). Notenormal left posterior communicating artery (short white arrow).


Cerebral tumours

Cerebral tumours are more common inadults, with a peak incidence at 55–65

years. Patients usually present with focalneurological deficit, personality changeor seizures. They may be agitated or confused at presentation.

Fig. 12.10 Post-contrast CT scan showing a ring-enhancing abscess within the left fronto-parietal region (long white arrow). Note the large amount of surrounding low-density oedema (small white arrows). The differential diagnosisincludes a primary tumour or metastasis.

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The most common tumours, in orderof their incidence, are:• Gliomas• Metastases• Meningiomas.Posterior fossa tumours are morecommon in children than adults.Gliomas may have similar imaging char-

acteristics to cerebral abscesses and the diagnosis is often dependent on theclinical findings. The level of contrastenhancement on CT and MRI correlateswith the grade of tumour (Fig. 12.11).

Metastases represent approximately20% of all intracranial tumours, and upto 85% of cases demonstrate more than

Fig. 12.11 Coronal post-contrast T1-weighted image through the bodies of thelateral ventricles in a patient with a glioma. There is an ill-defined mass crossing themid line (long arrows), which has some patchy internal enhancement. The maindifferential diagnosis for lesions that involve the corpus callosum and cross the midline is glioma or lymphoma.


one lesion. The primary site is mostcommonly lung, and patients with suspected metastatic disease should have a CXR. Other primary sites includebreast, genitourinary and gastroin-testinal tracts, thyroid and melanoma.Metastases usually demonstrate contrastenhancement on CT (Fig. 12.12) andMRI. MRI is more sensitive for lesiondetection than CT and its multiplanarcapability is useful for localizing lesionsfor biopsy.

Multiple sclerosis

Multiple sclerosis (MS) is a relapsing/remitting demyelinating disorder. Pa-tients present with a spectrum of symp-toms, which can be mild such asnumbness in hands or feet, or reducedvision, or severe such as hemiplegia orparaplegia. It is more common inwomen, with 95% of cases occurringbetween 18 and 50 years.

MRI is the most accurate imagingmodality for patients with suspectedMS, with a sensitivity of 85%.

MS plaques typically have an ovalshape and are bright or high signal onT2-weighted images (Fig. 12.13). Theymost characteristically occur in thewhite matter around the ventricles but can also occur in the brainstem, posterior fossa and spinal cord.

The MRI findings are suggestive of MS when three or more lesions > 5 mm are present in a periventricular location.

As MS is a clinical diagnosis, the appearances are suggestive but not diagnostic of the disease. There areseveral other causes of white matterdisease, such as ischaemia, infection and

vasculitic disorders, and so the clinicalhistory is extremely important.

Cord compression

Metastatic disease involving the spinecauses neurological deficit in up to 10%of cancer patients. If this results in cord compression, there is a dramatic reduction in the patient’s quality oflife and life expectancy.

Most spinal metastases occur byhaematogenous spread from carcinomaof the: • Breast• Lung• Prostate• Kidney• Thyroid.Spine involvement also occurs withmyeloma, lymphoma and leukaemia.Cord compression can also occur withdisc prolapse and infection. An urgentMRI scan is indicated if a patient hassigns and symptoms of cord compres-sion:• Reduction or loss of motor function(often lower limb — cauda equina syndrome)• Reduction or loss of sensation (asensory level may be demonstrated)• Bladder dysfunction• Loss of anal tone.

Discussion with senior colleagues isadvised to obtain an urgent MRI scan.This may not be available out of normalworking hours and arrangements may beneeded to transfer the patient forimaging and treatment. Urgent treatment usually involves radiotherapyor decompressive surgery and this hasbeen shown to significantly reduce mor-bidity. Be available for imaging results.

210 CHAPTER 12

Fig. 12.12 Post-contrast CT scan of a patient with metastatic melanoma. Note the enhancing lesions within the left frontal lobe and the left middle cerebellar peduncle (arrows) and associated low attenuation oedema.


Fig. 12.13 Axial FLAIR (a T2-weighted, CSF subtracted) MR image demonstrates multiple high-signal periventricular lesions (arrows) suggestive of demyelination.FLAIR is a MR sequence sensitive in the detection of MS plaques.

212 CHAPTER 12

Fig. 12.14 Sagittal T1-weighted post-contrast MR image of the cervical and upperthoracic spine in a patient with known metastatic breast cancer. There is a largeplaque of extradural metastatic tumour at the T1/T2 level (large white arrow),which significantly reduces the calibre of the spinal canal and compresses the cord.Note normal cord above and below the level of compression (small white arrows).


MRI

MRI clearly defines the level of abnor-mality (there may be several) necessaryfor treatment and is able to demonstratewhether the cord or exiting nerve rootsare involved (Fig. 12.14).

Other forms of imaging such as plain

radiographs, CT or radioisotope bonescans are far less sensitive and specific.

Further reading

Orrison WW, ed. Neuroimaging.Philadelphia: Saunders, 2000.

abdomensepsis 93–5trauma 124, 126–8

abdominal X-ray 10abdominal trauma 126aortic aneurysm 50appendicitis 82bowel perforation/obstruction 57caecal volvulus 100, 101cholecystitis

acute 105–6chronic 107, 108

choledocholithiasis 110colitis 100colonic obstruction 84–5Crohn’s disease 96, 99diverticulitis 85emphysematous pyelonephritis 185,

186gastric carcinoma 64gastric dilatation 69, 70hepatic abscess 115hepatic metastases 110hepatobiliary imaging 104intraperitoneal abscess 93–4lower gastrointestinal tract 81pancreatitis 117–18, 119, 120pneumoperitoneum 72, 73psoas abscess 95pyelonephritis 185renal cell carcinoma 185sigmoid volvulus 101, 102small bowel obstruction 69, 71–2subphrenic abscess 94ulcerative colitis 96, 98urinary calculi 178, 180, 181urinary tract obstruction 177urogenital tract imaging 175urothelial tumours 189

abscessappendix 82cerebral 204, 205–6, 207Crohn’s disease 99intraperitoneal 93–4liver 114–15, 116lung 35–6pancreas 118–19pericolic 87psoas 95renal 185small bowel 76

achalasia 60, 63oesophageal dilatation 57

adenomatous polyposis syndrome 89adult polycystic disease 184air bronchogram 35, 36air-space disease 17alcohol consumption

cirrhosis 115pancreatitis 117, 119

anaemiaaplastic 1myeloma 144

anaphylaxis 11aneurysms

aortic abdominal 49–50subarachnoid haemorrhage 204,

206angiography

abdominal trauma 128cerebral 204peripheral 40peripheral vascular disease 50–1,

52–3, 54renal cell carcinoma 187see also magnetic resonance

angiography (MRA)anticoagulation 204

Index

Note: page numbers in italics refer to figures and boxes, those in bold refer to tables.

214

INDEX 215

a1-antitrypsin deficiency 26aortic aneurysm, abdominal 49–50aortic dissection, thoracic 48–9aortography 48–9appendicitis 82–3appendicolith 82appendix, abscess 82arteriovenous malformations 204arthritis

gout 141septic 158, 159

asbestos-related lung disease 37–8asbestosis 38

interstitial fibrosis 39Aspergillus (aspergillosis)

allergic bronchopulmonary 26pneumonia 35

asthma 5pneumothorax 26

atelectasis 118atlanto–axial joint 150attenuations, X-ray 9audit 8

bacterial overgrowth, diverticular 79balloon dilatation 60barium

aspiration 11peritonitis 10–11, 82

barium enema 10colon adenocarcinoma 91, 92contraindication 11, 82Crohn’s disease 74, 99diverticular disease 85, 87, 88double-contrast 90, 91ionizing radiation dose 10polyp detection 90, 91small bowel 57

obstruction 72ulcerative colitis 96

barium examinations 10–11appendicitis 83contraindications 10–11, 82, 85gastric volvulus 69large bowel 11malabsorption 77, 80

oseophagitis 60, 61upper gastrointestinal tract 57

barium meal 10gastric carcinoma 64–5

barium sulphate 10barium swallow 10

achalasia 60oesophageal carcinoma 58, 59oesophagitis 61, 62

Barrett’s oesophagus 58basilar impression 162Bence Jones proteinaemia 144berry aneurysm rupture 204bile, limey 107bile duct stricture 122–4, 125biliary cirrhosis 115biliary tree

air 71barium reflux 70

bladder see gall bladder; urinary bladderblind-loop syndrome 77blood dyscrasias 141bone

metastases 191remodelling 162

bone scan 14diabetic foot 161Paget’s disease 162septic arthritis 158

Bouchard’s nodes 138bowel obstruction 57bowel perforation 10–11, 57, 82, 85breast 129–36

cysts 130, 131, 132fibroadenoma 130, 133imaging strategy 129–30

breast carcinoma 132–3, 134–6ductal carcinoma in situ 132, 134liver metastases 113metastases 133, 143, 212

breast diseasebenign 130, 131, 132, 133inflammatory 130, 132

bronchial carcinomamediastinal 55metastases 143

216 INDEX

bronchiectasis 26–8traction 39

bronchitis, chronic 25, 26broncho-alveolar cell carcinoma 20bronchogenic tumour 20bronchopneumonia 35bronchoscopy 20

caecal carcinoma 93caecal volvulus 100, 101calcification

aortic aneurysm 50gall bladder wall 107, 108gallstones 101, 107gastric carcinoma 64pancreas 119, 120renal tract 175testicular microlithiasis 193urinary tract 178–80, 181, 182urothelial tumours 189vascular in diabetic foot 159, 160

calcitonin serum level 167calcium monosodium urate crystals 141candidiasis, oesophagitis 60, 62cardiac failure 41–3, 81

congestive 30, 31, 32cardiothoracic ratio 40cardiovascular system 40–56

imaging strategy 40–1carotid artery, common 199carotid artery, internal

atherosclerotic plaque 202stenosis 199, 202

cauda equina syndrome 209central nervous system 195–213

imaging strategy 195–6trauma 196

central venous line placement 33cerebellar haematoma 203, 204cerebral abscess 205–6, 207

differential diagnosis 204cerebral angiography 204cerebral artery, middle 201cerebral hemispheres

haematoma 203metastases 208–9, 210

cerebral herniation 196cerebral infarction 199, 201, 203cerebral infection 204–6, 207cerebral mass effect 196, 197–8cerebral tumours 207–9, 210cerebrovascular disease 199, 201–2cervical adenopathy, metastatic 174cervical (uterine) carcinoma, metastases

143cervical lymph nodes 172–4

carcinoma 173metastases 164, 170, 172ultrasonography 163

cervical lymphadenopathy 163, 173cervical spine 146–7, 148–9, 150, 151

fracture 147, 149, 150, 151hyperextension injury 150hyperflexion injury 147, 149metastases 212rheumatoid arthritis 150, 152trauma 147, 149, 150

Charcot’s joints 159, 160chest X-ray 10

achalasia 60aortic dissection 48asthma 26bowel perforation/obstruction 57bronchiectasis 27–8cardiac failure 42–3cardiovascular system 40cerebral metastases 209chronic obstructive airways disease

26, 27colonic obstruction 85costophrenic angle 31, 32emphysema 26gastric carcinoma 64gastric volvulus 69hepatic abscess 115indications 16interstitial fibrosis 39lower gastrointestinal tract 81lung carcinoma 17, 18–19lung metastases 22, 23, 133lymphangitis carcinomatosa 24, 25mesothelioma 38

INDEX 217

oesophageal carcinoma 58pancreatitis 118pericardial effusion 55pleural effusions 31–2, 33pneumonia 35pneumothorax 33, 34pulmonary embolism 43radiation dose 3respiratory system imaging

16–17rheumatoid arthritis 141rib metastases 133sarcoidosis 29–30standard views 16–17superior vena cava syndrome 56tuberculosis 30

Chilaiditi’s syndrome 72, 76cholangiocarcinoma 122cholangiography 110, 112cholecystectomy 122cholecystitis

acute 105–7chronic 107–8, 109, 110complications 107emphysematous 107

choledocholithiasis 110, 111, 112cholescintigraphy 106–7chondrocalcinosis 141chronic obstructive airways disease

25–6CXR 26, 27pneumothorax 33

circle of Willis aneurysm 206cirrhosis 115, 117code of practice 1coeliac disease 77colitis 95–6, 97–8, 99–100

inflammatory 82ischaemic 99–100

Colles’ fracture 154, 155colon

diverticular disease 85, 87–9fistula formation 92obstruction 83–5

colorectal carcinoma 92perforation 92

colon carcinoma 83, 84adenocarcinoma 90–2, 93

Crohn’s disease 99ulcerative colitis 96

contrast enema 86diverticulitis differential diagnosis

88hepatic metastases 114metastases 85ulcerative colitis 97

colonoscopycolon adenocarcinoma 91colorectal polyps 90diverticular disease 88–9

colorectal carcinoma 89–93follow-up 92–3local complications 92metastases 93MRI 82recurrence 92–3

colorectal diseasecontrast enema 81–2CT 81ultrasonography 81

colorectal polyps 89–90, 91colour Doppler ultrasonography

deep vein thrombosis 46, 47peripheral vascular disease 50popliteal vessels 46, 47pulmonary embolism 43

communication 7computed tomography (CT) 12–13,

114abdominal trauma 127–8adult polycystic disease 184aortic aneurysm 50aortic dissection 48, 49aorto-pulmonary window 21appendicitis 83artefacts 13barium artefacts 11bile duct stricture 122bone window 12breast imaging 130bronchiectasis 28cardiovascular system 40

218 INDEX

computed tomography (cont’d)central nervous system 195cerebral abscess 206, 207cerebral infarction 199, 201cerebral metastases 209, 210cerebral tumours 208cervical lymph nodes 174cholecystitis 106choledocholithiasis 110CNS trauma 196colitis 100colon adenocarcinoma 91, 93colonic obstruction 85colonography 90colorectal carcinoma follow-up 92–3colorectal disease 81diverticulitis 87emphysema 26emphysematous pyelonephritis 185gall bladder carcinoma 108, 110gastric carcinoma 65hepatic abscess 115, 116hepatic metastases 111, 113, 114hepatobiliary imaging 105high-resolution 17

asbestosis 38interstitial fibrosis 39lymphangitis carcinomatosa 24–5sarcoidosis 30

intracerebral haematoma 203–4ionizing radiation dose 10liver cirrhosis 115, 117lung carcinoma 20, 21, 23lung metastases 23lung window 12, 21lymphangitis carcinomatosa 24–5malabsorption 80mediastinal window 21meningitis 204–5mesothelioma 38musculoskeletal system 137neck 164oesophageal carcinoma 58pancreatic carcinoma 120–1, 122pancreatitis 118–20patient preparation 13percutaneous abscess drainage 94

pleural effusion 33pneumoperitoneum 73, 77prostatic carcinoma 191–2psoas abscess 95pulmonary angiography 43pulmonary embolism 43, 45renal abscess 185renal cell carcinoma 187, 188renal cyst 184respiratory system imaging 17salivary gland pleomorphic adenoma

170sarcoidosis 30small bowel obstruction 72soft-tissue window 12standard 17subarachnoid haemorrhage 204, 205subdural haematoma 199, 200subphrenic abscess 94superior vena cava syndrome 56testicular tumour 193upper gastrointestinal tract 58urinary calculi 180urinary tract obstruction 178urogenital tract 176urothelial tumours 189

computed tomography (CT)angiography

cardiovascular system 40and portography 111, 114

computed tomography-guided biopsy20, 23

computerized radiography 15confidentiality 6conjunctivitis, radiation 1contrast enema 81–2

colonic obstruction 85, 86sigmoid volvulus 101

contrast media 10–11iodine-containing 3, 164ionic 11nephrotoxicity 4–5water-soluble 11

bowel perforation 73colonic obstruction 85, 86colorectal disease 82

contrast studies 10–11

INDEX 219

contrast X-ray venography 48cord compression 162, 209, 212, 213

metastases 209, 212costophrenic angle 31, 32Cowden’s syndrome 165Crohn’s disease 71, 73–6, 78, 96, 99

barium examination 80barium features 75colorectal carcinoma risk 89complications 76malabsorption 77

cystadenolymphoma 170cysteine calculi 178cystic fibrosis 26

deep vein thrombosislower limb 43, 45–8risk factors 45

dehydration, nephrotoxicity 4, 5dermatitis, radiation 1diabetes mellitus

emphysematous cholecystitis 107emphysematous pyelonephritis 185nephrotoxicity 4–5osteomyelitis 155pancreatitis 119renal abscess 185

diabetic foot 159, 160, 161diaphragmatic defect in gastric volvulus

68digestive enzyme deficiency 77D-dimer estimation 45, 46diverticular disease 85, 87–9

bacterial overgrowth 79colonic obstruction 83fistula formation 88haemorrhage 88–9sigmoid 77

diverticulitis 85, 87–8diverticulosis 77

jejunal 79, 80Doppler ultrasound 12drugs

interactions 5interstitial fibrosis 39

dual energy X-ray absorptiometry(DEXA) 152

duodenum, ileus 117–18dysphagia 60

echocardiography, pericardial effusion55

elderly patientsbarium examination 11nephrotoxicity 4, 5

emphysema 25–6emphysematous bullae 33empyema 33endoscopic retrograde

cholangiopancreatography(ERCP)

bile duct stricture 122–4, 125choledocholithiasis 110pancreatic carcinoma 121, 123pancreatitis 120

endoscopyachalasia of oesophagus 60upper gastrointestinal tract 57

epididymo-orchitis 194epithelial tumours, primary malignant

164Escherichia coli, hepatic abscess 114 -

index under ‘hepatic or liverabscess’

extradural haematoma 196, 197–8

facet joint dislocation 147feet

osteoarthritis 138osteomyelitis 155rheumatoid arthritis 140

femoral artery, peripheral vasculardisease 52–3

femoral hernia 71femoral neck fractures 154, 155fine-needle aspiration cytology (FNAC)

thyroid 165ultrasound-guided 163, 169

fistulacolon 92Crohn’s disease 99diverticular disease 88small bowel 76

fistulogram 76

220 INDEX

18 fluorine-fluorodeoxyglucose 15PET 164thyroid uptake 168

footdiabetic 159, 160, 161renal cell carcinoma metastases 144

forearm, Colles’ fracture 154, 155fracture

burst 150cervical spine 147, 149, 150, 151clay shoveller’s 147, 149Colles’ 154, 155femoral neck 154, 155insufficiency 154Jefferson 150, 151odontoid peg 150Paget’s disease 162pathological 143, 144sacral insufficiency 154spinous process 149teardrop of spine 147, 150wedge 147

fungal infectionsbronchiectasis 26pneumonia 35

gadolinium-based contrast 13gall bladder

calcified wall 107, 108carcinoma 107, 108, 110

bile duct stricture 122disease 105–8, 109, 110empyema 107perforation 107porcelain 107, 108wall thickening 106

gallstone ileus 71, 107, 109gallstones 105–8, 109, 110

calcified 101, 107pancreatitis 117

gamma camera 14gamma rays, high-energy 15Gardner’s syndrome 165gastric carcinoma 64–6, 69

metastases 57, 64, 65gastric dilatation 69

gastric leiomyoma 66gastric outflow obstruction 64, 69, 70gastric volvulus 68–9gastro-oesophageal reflux 60Gastrografin 11gastrointestinal tract, lower 80–102

imaging strategy 81–2gastrointestinal tract, upper 57–80

imaging strategy 57–8gastrointestinal tract carcinoma 143geodes 138, 139Glasgow Coma Score 196glioma 208glomerulonephritis, chronic 182glucose metabolism, PET 17goitre 164

anaplastic thyroid carcinoma 167extensions 165multinodular 164toxic multinodular 163

gout 141, 142, 178Graves’ disease 163, 164, 165guidelines 2–3

haematuria 175, 178prostatic carcinoma 191urothelial tumours 188

haemoperitoneum 127haemorrhage in diverticular disease

88–9hands

osteoarthritis 138osteomyelitis 155rheumatoid arthritis 140

harm 1–2Hashimoto’s thyroiditis 165, 168head injury 196heart

enlargement 42see also cardiac failure

Heberden’s nodes 138hemidiaphragm, elevated 118hepatic duct cholangiocarcinoma

124–5hepatitis 5

viral 115

INDEX 221

hepatobiliary imaging 104–16, 117strategy 104–5see also liver

hepatocellular carcinoma 111hip

osteoarthritis 138, 139septic arthritis 159

HIV infection, protective measures 6Homan’s sign 45hydrocephalus 204

obstructive 162hydrocoele 192hydronephrosis 176, 177–8hypercalcaemia 144

with hypercalciuria 178hyperflexion injury of spine 147, 149hyperoxaluria 182hyperparathyroidism 178, 182hypertension, aortic dissection 48hypertensive haemorrhage 204hyperthyroidism 163, 164hyperuricaemia 141hypoalbuminaemia, pleural effusions

30hypothyroidism 164

ileitisbackwash 95terminal 77

ileocaecal valve 83–4incompetence 100, 101obstruction 107, 109

ileumCrohn’s disease 74, 76, 78terminal 95

image interpretation 7imaging

equipment 2priorities 7–8staff 2techniques 9–15

immunocompromise 6bronchiectasis 26emphysematous pyelonephritis 185infective oesophagitis 60pneumonia 35

infections 5–6bronchiectasis 26cerebral 204–6, 207cord compression 209diabetic foot 159Gram-negative 35pleural effusions 31salivary gland 169staff protective measures 6

inferior vena cava 187inflammatory disease, salivary glands

168–9informed consent 6inguinal hernia 71interferon 5interstitial fibrosis 17, 38–9intervertebral discs 147

prolapse 209intimal flaps 48, 49intracerebral haematoma 203–4intraperitoneal abscess 93–4intravenous contrast agents 11intravenous urography 175, 178, 179

renal cell carcinoma 187renal cyst 183–4urinary calculi 179urothelial tumours 189

intraventricular shunt 200, 204iodine

allergy 11CT 13

excess intake 165hypersensitivity 3

ionic contrast agents 11ionizing radiation see radiationIonizing Radiation (Medical Exposure)

Regulations (IRMER, 2000) 1, 7

Kartagener’s syndrome 26kidney

carcinoma 143, 144focal calcification 182fracture 127medullary sponge 182ultrasonography 176see also nephrotoxicity; renal entries

222 INDEX

Klebsiellabronchiectasis 26pneumonia 35

knee osteoarthritis 138

large bowelbarium examinations 11pseudo-obstruction 85

Legionella pneumonia 35legislation for ionizing radiation use 1leiomyoma 66, 67liver

abscess 114–15, 116interventional treatment 115, 116

cirrhosis 115, 117colorectal carcinoma metastases 93guided biopsy 111, 113metastases 110–11, 113, 114see also hepatobiliary imaging

lumbar spine, osteomyelitis 155lung

abscess 35–6apical bullae 26asbestos-related disease 37–8cavitation 36consolidation 35, 36ground glass appearance 39hyperlucent 27interstitial disease 17interstitial fibrosis 38–9loculation 32metastases 22, 23, 133, 164, 170non-surgical lobar collapse 18–19parenchymal disease 29, 30rheumatoid nodules 141scintigraphy in pulmonary embolism

43, 44see also pulmonary entries

lung carcinoma 17–20, 21–2, 23clinical presentation 17–18CT 20, 21, 23CXR 17, 18–19metastases 20PET 23squamous cell 18staging 15

lymph nodesmetastases 165sarcoidosis 28–9

lymphadenopathy, metastatic 164lymphangitis carcinomatosa 24–5lymphoma

cervical lymph nodes 172hepatic metastasis differential

diagnosis 111malabsorption 80metastases 143PET 164Sjögren’s syndrome 169staging 15superior vena cava syndrome 55thyroid 168

magnetic resonance angiography(MRA) 14

cardiovascular system 40circle of Willis aneurysm 206peripheral vascular disease 50subarachnoid haemorrhage 204, 206

magnetic resonancecholangiopancreatography(MRCP) 105

choledocholithiasis 110, 111pancreatitis 120, 121

magnetic resonance imaging (MRI)13–14, 17

adult polycystic disease 184aortic dissection 48breast imaging 130cardiovascular system 40central nervous system 195–6cerebral abscess 206cerebral infarction 199cerebral metastases 209cerebral tumours 208cervical lymph nodes 174CNS trauma 196colorectal carcinoma 82contraindications 14cord compression 209, 212, 213diabetic foot 161gadolinium enhancement 206

224 INDEX

Mycobacterium tuberculosis 30Mycoplasma pneumonia 35myeloma 144, 146myeloproliferative disorders 141

nasopharyngeal carcinoma 174neck 163–74

imaging strategy 163–4nephrocalcinosis 182nephrotoxicity 4–5

CT 13water-soluble contrast agents 11

nerve entrapment 162non-Hodgkin’s lymphoma 168, 172non-ionic contrast agents 11nuclear medicine 14

breast imaging 130cardiovascular system 40cholecystitis 106–7Graves’ disease 165hepatobiliary imaging 105inflammatory colitis 82multinodular thyroid 165musculoskeletal system 137neck 163–4prostatic carcinoma 192thyroid 164upper gastrointestinal tract 58

odontoid peg fracture 150oesophageal carcinoma 58, 59, 60

achalasia 60metastases 57, 58oesophageal dilatation 57palliative treatment 60

oesophageal dilatation 57oesophageal leiomyoma 66, 67oesophagitis 60, 61–2

infective 60, 62reflux 60, 61

oesophagus, dilated 60osteoarthritis 138, 139

Paget’s disease 162osteomyelitis 154–5, 156–7, 158

diabetic foot 161osteopenia 140, 144, 150, 152

osteophytosis 138, 139osteoporosis 150, 152, 153, 154

postmenopausal 152, 153, 154senile 154

oxalate calculi 178oxalosis 182

pacemaker placement 33Paget’s disease 161–2pancreas

abscess 118–19calcifications 119, 120pseudocyst 118, 119

pancreatic carcinoma 69, 70, 119,120–1, 122, 123

bile duct stricture 122metastases 121

pancreatic duct dilatation 119–20pancreatitis

acute 117–19chronic 77, 119–20, 121

papillary cystadenoma 170parapharyngeal space tumours 164parotid glands

mumps 168–9ultrasonography 163

parotid tumoursMRI 164mucoepidermoid carcinoma 171,

172patients

identification errors 3records computerization 3safety 3–6

pelvicalyceal dilatation 178peptic strictures 60peptic ulcer disease 69percutaneous transhepatic

cholangiography (PTC) 122–4,125

perianal disease, Crohn’s disease 96pericardial effusion 54–5pericolic abscess 87perineural tumours, MRI 164periosteal reaction 156, 158

diabetic foot 161

INDEX 225

peripheral angiography 40peripheral vascular disease 50–1, 52–3,

54peristalsis, absence 60peritoneal ligaments,

pneumoperitoneum 72picture archiving and communication

system (PACS) 15pleural calcification 37pleural effusion 19, 30–3

cardiac failure 42gastric carcinoma 64loculated 31, 32, 33malignancy 31pancreatitis 118pneumonia 35subpulmonary 32thoracic aortic dissection 49

pleural plaques 37Plummer’s disease 163pneumocystis pneumonia 35pneumonia 20

acute 35–6aspiration 57chronic hypersensitivity 39CT 17

pneumoperitoneum 72–3, 74, 75, 76,77

pneumoretroperitoneum 73pneumothorax 26, 33, 34

asthma 26tension 34–5

popliteal vessels, colour Doppler 46positive pressure ventilation,

pneumothorax 33positron emission tomography (PET)

15lung carcinoma 23neck 164oesophageal carcinoma 58respiratory system imaging 17

pregnancy, ionizing radiation 10propylthiouracil 164prostate-specific antigen (PSA) 192prostatic carcinoma 143, 189, 191–2

metastases 191

protocols 2–3psoas abscess 95pulmonary angiography 43pulmonary embolism 43, 44, 45

pleural effusions 31pulmonary oedema

cardiac failure 42–3CT 17

pyelonephritis 184–5emphysematous 185, 186

radiationdoses 3, 4exposure to external 165ionizing 10

radiographyabdominal trauma 126computerized 15exposure times 1history 1musculoskeletal system 137osteoporosis 152, 153prostatic carcinoma 191

radiopharmaceuticals 14referrals, making 6–7regulations for ionizing radiation use 1renal abscess 185renal calculi 176, 178–80, 181

impacted 177renal cell carcinoma 185–7, 188

metastases 144, 185renal colic 177, 178, 179renal cortical necrosis 182renal cyst disease 182–4renal failure 175, 176–8, 179

chronic 141renal insufficiency 144renal obstruction, emphysematous

pyelonephritis 185renal tract calcification 175renal tubular acidosis 182research 8respiratory system 16–39

imaging strategy 16–17responsibility delegation 7retrograde pyelogram, 190 189

226 INDEX

rheumatoid arthritis 138–41cervical spine 150, 152interstitial fibrosis 39

rheumatoid factor 140rheumatoid nodules 140, 141rib metastases 133Rigler’s sign 72, 73

S-sign of Golden 19sacral insufficiency fractures 154sacroiliitis 71salivary glands 168–70, 171, 172

acinic cell carcinoma 172adenoid cystic carcinoma 172calculi 163CT 164inflammatory disease 168–9malignancies 170, 171, 172metastases 172mucoepidermoid carcinoma 171,

172neoplasms 169–70, 171, 172pleomorphic adenoma 169–70

sarcoidosis 17, 28–30interstitial fibrosis 39

sarcomatous change 162scleroderma, interstitial fibrosis 39scrotum, acute 194seminoma 192, 193sepsis, chest 81short bowel syndrome 77sialadenitis 164sialectasis 163sialocele 163sialography, conventional 163sialolithiasis 168, 169

chronic 169sigmoid volvulus 101, 102sigmoidoscopy, large bowel pseudo-

obstruction 85Sjögren’s syndrome 169skeletal metastases 143–4, 145skip lesions 76skull fracture 196, 198small bowel

abscess 76

adenocarcinoma 76adhesions 69, 71barium enema 57barium follow-through 10, 57, 72

Crohn’s disease 74dilated loops 69, 71fistula 76ischaemia 72obstruction 69, 71–2perforation 71, 73strictures 76see also Crohn’s disease

spinehyperflexion injury 147, 149metastases 209, 212osteoarthritis 138osteomyelitis 155vertebral compression injury 150see also cervical spine; thoracic spine

spinous process fracture 149spleen rupture 126, 127Staphylococcus

bronchiectasis 26pneumonia 35

Staphylococcus aureusseptic arthritis 158see also methicillin-resistant

Staphylococcus aureus (MRSA)stents

bile duct stricture 124, 125gastric carcinoma 65oesophageal 60superior vena cava 56

steroidsasthma 5premedication 11

STIR image, osteomyelitis 13, 157, 158stomach rotation 68streptococci, hepatic abscess 114Streptococcus pneumoniae 35, 36subarachnoid haemorrhage 204, 205,

206subdural haematoma 199, 200sublingual gland tumours 170submandibular glands

malignancy 170

INDEX 227

ultrasonography 163subphrenic abscess 94subpleural bleb rupture 33superior vena cava syndrome 55–6superior vena cava venography 56

99mTc methylene diphosphonate 14technetium 14temporal bone fracture 198teratoma 192, 193testes 192–4testicular microlithiasis 193testicular torsion 194testicular tumour 192–3thoracic spine 153

metastases 212thrombolysis, peripheral vascular

disease 51, 54thyroid 164–8

autoimmune disease 165lymphoma 168multinodular 165, 166ultrasonography 163

thyroid carcinomaanaplastic 167CT 164FDG-PET 164follicular 166–7medullary 167–8metastases 143, 164, 167papillary 165, 167residual disease 164screening 165

thyroid nodules 163, 164, 165thyroiditis 168tibia, osteomyelitis 156–7tissue plasminogen activator (t-PA),

recombinant 51tophi 141toxic adenoma 163, 165toxic megacolon 82, 96, 98

Crohn’s disease 99transient ischaemic attacks (TIAs) 199,

202transoesophageal echocardiography 48trauma

abdominal 124, 126–8cervical spine 147, 149, 150CNS 196, 204pleural effusions 31pneumothorax 33

tuberculosis 5, 30bronchiectasis 26cervical lymph nodes 172miliary 30pneumonia 35primary 30reactivated 30

ulcerative colitis 89, 95–6, 97–8colon carcinoma 96, 97complications 96, 98, 99

ulcerative pancolitis 98ultrasonography 12

abdominal trauma 126–7adult polycystic disease 184aortic aneurysm 50appendicitis 82, 83bile duct stricture 122breast carcinoma 133, 136breast fibroadenoma 130, 133breast imaging 130cardiovascular system 40cervical lymph nodes 173cholecystitis

acute 106chronic 107

choledocholithiasis 110colon adenocarcinoma 92colorectal disease 81deep vein thrombosis 45–8diverticulitis 87Doppler 12duplex scan in TIAs 199, 202endoscopic

gastric carcinoma 65–6oesophageal carcinoma 58

epididymo-orchitis 194gall bladder carcinoma 108Graves’ disease 165Hashimoto’s thyroiditis 168hepatic abscess 115

228 INDEX

ultrasonography (cont’d)hepatic metastases 111, 113hepatobiliary imaging 104–5imaging strategy 163intraperitoneal abscess 94kidney 176liver cirrhosis 115multinodular thyroid 165, 166musculoskeletal system 137neck 163pancreatic carcinoma 120pancreatitis 118, 119percutaneous abscess drainage 94pleural effusion 33prostatic carcinoma 191psoas abscess 95pyelonephritis 185renal abscess 185renal cell carcinoma 185–6, 187renal cyst 183respiratory system imaging 17salivary gland

infection 169neoplasms 169, 170

sialolithiasis 168, 169small bowel obstruction 72subphrenic abscess 94testicular tumour 192, 193thyroid carcinoma 165, 167, 167,

168thyroid lymphoma 168upper gastrointestinal tract 58urinary tract obstruction 177–8urogenital tract 175urothelial tumours 189Warthin’s tumour 170see also colour Doppler

ultrasonographyuric acid calculi 178urinary bladder

air in 88calculi 176carcinoma metastases 143

dysfunction 209outflow obstruction 177tumours 189

urinary calculi 178–80, 181urinary sepsis 178urinary stasis 178urinary tract

calcification 178–80, 181, 182infection 184–5obstruction 177–8

urogenital tract 175–94imaging strategy 175–6

Urografin 11urothelial tumours 188–9, 190

squamous cell carcinoma 188, 189transitional cell carcinoma 188

uterine carcinoma metastases 143

valvulae conniventes 69, 71venography, superior vena cava 56ventilation/perfusion (V/Q) scan 14

pulmonary embolism 43, 44vertebrae

compression injury 150osteomyelitis 155

vertebral bodies 147osteoporosis 153subluxation 147wedging 153

vesico-ureteric junction calculi 178viral infections, pneumonia 35volvulus, colonic obstruction 83von Hippel–Lindau syndrome 185

Warthin’s tumour 170Whipple’s disease 77wrist, rheumatoid arthritis 139

X-ray cameras, digital 15X-rays, conventional 9–10

dosage 10sialolithiasis 168

xanthochromia 204

Hands on guide to imaging 1 ed 2004

Health & Medicine

Transcript of Hands on guide to imaging 1 ed 2004