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Principles and Practice of

ULTRASONOGRAPHY

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Principles and Practice of

ULTRASONOGRAPHYSECOND EDITION

Satish K Bhargava MD (Radiodiagnosis), MD (Radiotherapy)DMRD, FICRI, FIAMS, FCCP, FUSI, FIMSA, FAMS

Professor and HeadDepartment of Radiology and ImagingUniversity College of Medical Sciences(Delhi University) and GTB Hospital

Dilshad Garden, Delhi, India

JAYPEE BROTHERS MEDICAL PUBLISHERS (P) LTDNew Delhi • St Louis (USA) • Panama City (Panama) • London (UK) • Ahmedabad • Bengaluru

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Published byJitendar P VijJaypee Brothers Medical Publishers (P) Ltd

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Principles and Practice of Ultrasonography

© 2010, Jaypee Brothers Medical Publishers

All rights reserved. No part of this publication should be reproduced, stored in a retrieval system, or transmitted in any formor by any means: electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of theeditor and the publisher.

This book has been published in good faith that the material provided by contributors is original. Every effort is made toensure accuracy of material, but the publisher, printer and editor will not be held responsible for any inadvertenterror (s). In case of any dispute, all legal matters are to be settled under Delhi jurisdiction only.

First Edition: 2002

Second Edition: 2010

ISBN 978-81-8448-905-7

Typeset at JPBMP typesetting unit

Printed at

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My late parentsSh Jagannath Bhargava and Smt Brahma Devi Bhargava

My loving late wife KalpanaMy son Sumeet and his wife Shivani

My brothers and sistersSurendra, Munish, Narendra and Santosh

whose inspiration and sacrifice havemade possible to bring out this book

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Contributors

A VermaResident Medical Officer, Arpana HospitalKarnal (Haryana), India

AK Srivastava Physicist

Department of Radiology and ImagingUniversity College of Medical Sciences(Delhi University) and GTB Hospital,Dilshad Garden, Delhi, India

Atin Kumar MD (Radiodiagnosis)

Assistant Professor, Department ofRadiodiagnosisAll India Institute of Medical SciencesAnsari Nagar, New Delhi, India

Atul Luthra MBBS, MD, DNB

Diplomate, National Board of MedicineConsultant, Physician and CardiologistNew Delhi, India

Brig. Chander Mohan MD (Radiodiagnosis)

Sr. Consultant, Interventional Radiology andHOD RadiologyBL Kapoor Memorial HospitalPusa Road, New Delhi, India

Gopesh Mehrotra MD (Radiodiagnosis)

Professor, Department of Radiology andImaging, University College of Medical Sciences(Delhi University) andGTB Hospital, Dilshad Garden, Delhi, India

IK InderjitAir Force HospitalBengaluru, India

Karuna Taneja MD (Radiodiagnosis)

Ex Associate ProfessorDepartment of Cardiac RadiologyAll India Institute of Medical SciencesAnsari Nagar, New Delhi, India

M PatelINHS, Port Blair, India

Poonam Narang MD (Radiodiagnosis)

Professor, Department of RadiologyMaulana Azad Medical College and AssociatedGB Pant Hospital, New Delhi, India

Rajul Rastogi MD (Radiodiagnosis)

Head, Department of RadiologyYash Diagnostic Center, Civil LinesMoradabad, India

Rekha Jain MD (Radiodiagnosis)

St Joseph Mery HospitalPontiac, Michigan, USA

Rohini Gupta MD (Radiodiagnosis)

Assistant ProfessorDepartment of Radiology and ImagingVardhman Mahavir Medical College andAssociated Safdarjung Hospital, Delhi, India

Satish K Bhargava MD (Radiodiagnosis)MD (Radiotherapy), DMRD, FICRI, FIAMS, FCCP,FUSI, FIMSA, FAMSHead, Department of Radiology and ImagingUniversity College of Medical Sciences(Delhi University) and GTB HospitalDilshad Garden, Delhi, India

Shuchi Bhatt MD (Radiodiagnosis), MNAMS, FICR

Reader, Department of Radiology and ImagingUniversity College of Medical Sciences(Delhi University) and GTB HospitalDilshad Garden, Delhi, India

Sudhanshu Bankata MD (Radiodiagnosis)

Dy. General Manager (Medical)Fortis Health Care, Escort Heart Institute andResearch CentreOkhla Road, New Delhi, India

Sumeet Bhargava MBBS, DNB (Radiodiagnosis)

Sr. Resident, Department of RadiodiagnosisAll India Institute of Medical SciencesAnsari Nagar,New Delhi, India

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Preface to the Second Edition

Ultrasound being non-ionizing, non-invasive, and relatively cheap modality is widely acceptable indeveloping countries as a first line of investigation in diagnostic armentarium. Due to recentadvancement in transducer technology, availability of high frequency transducers and betterresolution, its application has extended in almost every system of the human body. Due to wideapplication and the demand of this book from the readers not from this country but also from abroad,it was decided to come out with the latest Edition with more number of illustrations. Addition of newchapters on Color Doppler, Echo-cardiography and Intravascular Ultrasound–Current Concept willdefinitely be beneficial to postgraduates and practitioners.

Satish K Bhargava

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Preface to the First Edition

Introduction of ultrasound was a boon to the medical field, due to its noninvasive and non-ionizingnature leading to constantly growing interest in the application of ultrasound as a diagnostic modality.Its easy acceptability in the developing countries is also because of its wide availability and low cost.

Ultrasound is a stethoscope of a radiologist to look into the intriguing pathological conditionsand provide useful information to the clinician for better patient care. However, this technology isvery much operator-dependent and thus a thorough understanding of standard scanning techniqueand knowledge of the sonographic anatomy is essential for optimum results. Thus we embarked onthe monumental task of providing a basic book on clinical diagnostic ultrasound. The main featureof this book is extensive coverage and easy comprehension. The book has gone deeply into normalsonographic anatomy and the basic technique of performing ultrasound. The book beautifully coverssonography of the abdomen and superficial parts. A special effort has been made to include a largenumber of illustrations and scans to provide a clear impression of the sonographic appearance ofnormal and pathologic lesions. Obstetric ultrasound has also been covered in the text. A chapter onDoppler has been included in order to provide the basic knowledge of the subject. Introduction tointerventions and latest advancement in ultrasound emphasises its importance in therapeutics.

I am sure that this book will be of great help to the budding radiologists and the technologists andhelp them in optimum utilization of this extremely useful modality and this in turn will bring laurelsto the professions.

Satish K Bhargava

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Acknowledgments

I am grateful to my colleagues and friends who gave timely support and stood solidly behind me inour joint endeavor of bringing out this Second Edition of book which was required keeping in viewof wide acceptability of ultrasound in developing countries like ours. I would also like to thankShri Jitendar P Vij, Chairman and Managing Director, Mr Tarun Duneja, Director-Publishing,Ms Samina Khan of M/s Jaypee Brothers Medical Publishers (P) Ltd. It is indeed the result of thehardwork of the staff of M/s Jaypee Brothers and the contributors who have always keen desire towork with a smiling faces and with polite voices as a result of which this book has seen the light ofthe day.

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Contents

1. Historical Perspective of Ultrasound 1Satish K Bhargava, AK Srivastava

2. Nature of Ultrasound 5AK Srivastava, Satish K Bhargava

3. Interaction of Ultrasound with Matter 10Satish K Bhargava, AK Srivastava, Sumeet Bhargava

4. Transducer 16Satish K Bhargava, Sumeet Bhargava

5. Basic Ultrasound Instrumentation 27Satish K Bhargava, AK Srivastava

6. Real-time Ultrasound 41AK Srivastava, Satish K Bhargava, Sumeet Bhargava

7. Ultrasound Artifacts, Biological Effects of Ultrasound Image Qualityand Instrumentation 51Gopesh Mehrotra, Satish K Bhargava

8. Scanning Techniques in Sonography 71Satish K Bhargava, Rajul Rastogi, Sumeet Bhargava

9. Basic Sonographic Anatomy 88Sumeet Bhargava, Satish K Bhargava, Atin Kumar, Rajul Rastogi

10. Abdomen: Hepatobiliary System and Spleen 175Shuchi Bhatt, Sumeet Bhargava, Atin Kumar

11. Abdomen: Pancreas 207Shuchi Bhatt, Rajul Rastogi, Sumeet Bhargava

12. Abdomen: Gastrointestinal Tract 214Shuchi Bhatt, Atin Kumar

13. Abdomen: The Urinary Tract 224Shuchi Bhatt, Sumeet Bhargava, Atin Kumar

14. Abdomen: Adrenal Glands 250Shuchi Bhatt, Satish K Bhargava, Rajul Rastogi

15. Abdomen: The Retroperitoneum 253Shuchi Bhatt, Rajul Rastogi, Sumeet Bhargava

16. Abdomen: The Peritoneum 259Shuchi Bhatt, Atin Kumar, Rajul Rastogi

17. Abdomen: The Uterus and Adnexa 266Rajul Rastogi, Shuchi Bhatt, Sumeet Bhargava

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xvi Principles and Practice of Ultrasonography

18. Pediatric Abdomen 283Satish K Bhargava, Shuchi Bhatt, Rohini Gupta, Sumeet Bhargava

19. Intracranial Sonography 299Sudhanshu Bankata, Sumeet Bhargava, Satish K Bhargava

20. Eye and Orbit 308Satish Bhargava, Rajul Rastogi, Sumeet Bhargava

21. Thyroid 317Sumeet Bhargava, Satish K Bhargava, Rajul Rastogi, Rekha Jain

22. Small Part Ultrasound 321Satish K Bhargava, Sudhanshu Bankata, Rajul Rastogi, Shuchi Bhatt

23. Ultrasound Examination of the Peripheral Arteries 345Satish K Bhargava, Rajul Rastogi, Sumeet Bhargava, Karuna Taneja

24. Intraoperative and Laparoscopic Sonography 365Satish K Bhargava, Sumeet Bhargava, Rajul Rastogi

25. Intravascular Ultrasound—Current Concepts 376Chander Mohan, M Patel, Rajul Rastogi, IK Indrajit, A Verma

26. Perendoscopic Ultrasound 389Sumeet Bhargava, Satish K Bhargava, Rajul Rastogi

27. Contrast Agents for Ultrasound 395Sumeet Bhargava, Satish K Bhargava

28. Normal Ultrasound Measurements 400Satish K Bhargava, Atin Kumar

29. Obstetric Ultrasound 413 Satish K Bhargava, Rajul Rastogi, Sumeet Bhargava

30. Interventional Radiology 473Poonam Narang

31. Color Doppler 480Shuchi Bhatt, Rajul Rastogi, Sumeet Bhargava, Satish K Bhargava

32. Basics of Echo 510Atul Luthra

Index 531

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30 Interventional Radiology

Interventional radiology deals with diagnosticand therapeutic management of pathologiclesions by the radiologist. This management maybe palliative, supplementary to other therapy ordefinitive.

Improvement in imaging technology, espe-cially the 3-dimensional imaging techniques hasopened new possibilities of approaching a lesion.Availability of better catheters, guide wires,biopsy sampling instruments and needles, havealso contributed to make these techniques simpler,and hence, the radiologists are venturing intonewer areas, making interventional radiology aseparate, new and adventurous branch ofradiology, with a lot of clinical overlap.

Vascular interventional techniques have alonger history than the nonvascular ones. Thischapter only intends to provide an introductoryoverview of these procedures.

Prerequisites of interventional procedures:1. Informed consent: Most of the interventional

procedures are alternatives to other methodsused previously, before interventions becamepossible. Therefore, consent of the patient aswell as that of the referring clinician is notonly desirable but mandatory before anyintervention is undertaken.

2. Assurance and adequate sedation.3. Local anesthesia as required.4. Complete asepsis: Complete asepsis of stan-

dards equipment, premises and personnel is

a must. A separate ultrasound machine/probeor fluoroscopic unit could be reserved forinterventional procedures wherever possible.Suitable sterile covers for ultrasound probesand CT table or fluorotables could bealternatively used.

5. Check on and correction if required ofbleeding disorders, e.g. prothrombin time.

6. Antibiotic/steroid cover wherever required.Imaging modalities used for guidance in

interventional procedures must provide threedimensional information. Fluoroscopic guidanceespecially with plain fluoroscopy or C-arm;ultrasound guidance or CT scanning are themodalities used for this purpose. MR has rarelybeen used although its role is being explored atpresent as a guiding tool for interventionalprocedures. Ultrasound provides dynamicinformation and can visualize the lesion as wellas the needle in real-time. It is, perhaps, the mostversatile guiding modalities used in hepatobiliaryand other abdominal and pelvic interventions. Itis also used in thorax, cranium and skeletallesions wherever an acoustic window is avai-lable.

Fluoroscopy is mostly used for vascularinterventions, although it can be successfullyused for thoracic and bony lesions as well.Although time consuming, CT is ideal modalityfor management of deep seated and small lesionsin abdominal, intrathoracic lesions and forskeletal lesions.

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474 Principles and Practice of Ultrasonography

Interventional techniques are broadly classi-fied into nonvascular and vascular procedures.

Nonvascular Procedures

1. Biopsy techniques2. Drainage techniques for various collections3. Percutaneous or endoscopic stent placement4. Lesion ablation.

Vascular Procedures

1. Embolization techniques2. Vascular dilatation with or without stenting3. Vascular therapy

– Chemotherapeutic agents– Dilators/constrictors– Intravascular thrombolysis– Intravascular extractions– IVC filters

Biopsy Techniques

Various equipments like biopsy track guides usedwith ultrasound equipment, surface grids tailor-made for CT or mammographic guidance andhead frames used for stereotactic guidance underCT/MRI imaging are available to facilitate needleplacement in the lesion for obtaining tissuesamples for histologic evaluations. However,most experienced radiologists prefer a free handtechnique under dynamic imaging control ofsonography. Fine needle aspiration (FNA) yieldssmaller cellular sample and may give false-negative results while core biopsy needlesalthough more risky are more efficient in provi-ding the requisite tissue samples. Whenever thereis presence of coagulopathies like prolongedprothrombin time and fear of traversing vesselsor important organs, FNA is preferred over cuttingor boring needles.

At times, the biopsy needle track needs to beembolized after obtaining the tissue sample, e.g.in presence of bleeding tendency or biopsyleakage. In such cases, a coaxial needle is used inwhich the inner needle obtains the sample while

the outer sheath is used to embolize the leak withmaterial like gel foam. Needle placement underCT guidance is more time consuming as repeatedscans are required to check the position of theneedle tip. However, it is indispensable fortransthoracic or of intrapulmonary /mediastinallesions, small deep-seated abdominal pelviclesions and even some spinal/skeletal lesions.For fluoroscopic guidance, at times the lesionneeds to be rendered radio-opaque by contrast,e.g. by IVU in renal biopsies, ERCP, angiography/renography.

At times, transjugular approach can also betried in cases with severely deranged coagulationand gross ascites with small lines wherepercutaneous biopsy is difficult and hazardous.

DRAINAGE TECHNIQUES

Drainage procedures are now accepted andwidely used not only as palliative procedures oradjuncts to surgery but as the treatment of choicein various situations.

They are suitable for large collections notresponding to medical treatment or where thereis fear of impending complications, e.g. large liverabscesses with or without biliary pseudocystsand pancreatic abscesses, large splenic ab-scesses/perisplenic collections, subphreniccollections, encysted pleural collections, post-operative intra-abdominal collections, bilomas,urinoma, hematometra, pelvic abscesses, psoasabscesses, etc.

The draining catheter needs to be self reta-ining, i.e. Foley’s, Malecot’s or pigtail catheter ofappropriate caliber having adequate number orsize of draining holes (in case of pigtail catheterswhich are most frequently used). At times, largerholes are punched on the catheter which isre-sterilized before insertion.

Percutaneous Insertion Techniques

The draining bag used can be an ordinary passivecollection bag or bag employing active suction,

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475Interventional Radiology

e.g. concertina suction bag or aseptic syringe.These suction bags providing active drainage aremore effective in keeping the cavities collapsedwhile enhancing healing.

The drainage time may vary from 5 days toeven 5 months or even longer in cases where thecavity refills due to a communication. Main-tenance of asepsis is of paramount importanceduring that period. Percutaneous feeding gastro-stomy /enterostomy employs the same techniqueused to place a self retaining catheter in distendedstomach under local anesthesia and anchoring itto the skin. It also provides a very useful portalfor feeding neurologically ill or debilitatedpatients.

Similarly percutaneous nephrostomy is auseful technique for decompression of hydro-nephrotic kidney due to supravesical obstruc-tion. Nephrostomy may further be followed bystricture dilatation, stenting, biopsy and stoneremoval, etc. as required in a particular case.

PERCUTANEOUS/ENDOSCOPIC STENTPLACEMENT

Technically, percutaneous stenting is an exten-sion of the percutaneous drainage techniquewhere instead of a draining catheter, a stent isthreaded over the guidewire through the dilatedtract.

Percutaneous stenting is used extensively inhepatobiliary obstruction as well as in uretericobstructions.

Endoscopic stent placement is used in lowerCBD obstruction and in esophageal and recto-sigmoid strictures. The technique is useful forboth benign and malignant strictures.

Hepatobiliary drainage techniques (with orwithout stenting) are as follows:• External drainage• Internal drainage• Internal-external drainage.

Chief indications for biliary drainage in spaceoccupying lesion (SOL) are:

• Palliation in cases of unresectable growth

• Therapeutic in benign strictures• Infective obstructive jaundice.

In the percutaneous technique, a guidewire isadvanced into the biliary system through thepercutaneous transhepatic cholangiographic(PTC) needle and manipulated into the commonbile duct with the help of high-torque catheters.The external drainage catheters are mainly forshort-term; used whenever the obstruction cannotbe passed with the guidewire. Internal drainagecatheters are usually self retaining and designedfor long-term drainage. Internal drainage isperformed by placing stents either percutane-ously or endoscopically. Multiple stents may attimes be required for multiple levels of obstruction.Usually obstruction at or above porta hepatis ismanaged percutaneously while below portaendoscopy is preferred. Cholangitis, sepsis, lossof bile salts and electrolytes, biliary peritonitis,pancreatitis, pneumothorax, bilothorax, hemo-rrhage and hemobilia are the common compli-cations of biliary intervention procedures.

LESION ABLATION

Technique of lesion ablation involves placing asuitable needle at the center of the lesion andcausing local tissue death by instilling fluids likealcohol, hypertonic saline or hot contrast materialor by coagulating the lesion by heat or laserdiathermy.

Unilocular hydatid cysts are effectively treatedby alcohol/saline injection. Similarly sympto-matic simple cysts of liver and kidney can beablated by this technique.

Hepatic malignancies like hepatocellularcarcinoma shows progressive size reduction onserial intralesional alcohol injections. Similarly,hepatic metastases especially those from colo-rectal malignancies when less than 4 in numbercan be effectively treated by laser ablation whenthe primary is completely resectable.

In cases of induced pregnancies wheremultiple gestation sacs are common, selectiveablation of sacs is accomplished by intrasac or

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even intracardiac instillation of potassiumchloride (KCl) solution.

VASCULAR INTERVENTIONS

Embolization

A vascular interventionist must be an expert inangiographic technique as these proceduresrequire great skill and experiences. The processof emboliation attempts to cut of completely orpartially, the blood supply to a specific region ororgan in the body.

The effects of emboliation depend on the endorgan and the type of embolizing material used.For example, organs like liver with dual bloodsupply can sustain embolization of hepatic arterywhile embolization of a renal artery resultsin definite ablation of the part or whole of thekidney supplied as it has no alternative bloodsupply.

Total asepsis, adequate sedation and post-procedure analgesia are necessary parts of theprocedure.

The catheter tip is placed as selectively aspossible to avoid ischemia to adjacent tissues.

Reflux of emboli from catheterized artery mustbe avoided at all costs as it can result inconsiderable morbidity and even mortality.Delivery of particulate material must be stoppedonce the flow is severely reduced.

Ideal embolizing material should be non-toxic, thrombogenic, easy to inject, radio-opaque,rapid and permanent in effect, sterile and readilyavailable.

Materials for Embolization

a. Absorbable materials– Analogous blood clot– Oxidized cellulose (Oxycel)– Gel foam.

b. Nonabsorbable materials– Particulate analogous fat/muscle

Ivalon (Polyvinyl alcohol sponge)Silastic spherules

Silastic and steel spheresAcrylic spheres

– Injectible fluid embolic agentsIBCA (isobutyl 2-cyano acrylate)Modified IBCATissue glueSilicon rubber

– SclerosantsEthanolHypertonic salineBoiling contrast medium

– Nonparticulate agentsSteel coilsModified coilsDetachable balloons

c. Endovascular electrocoagulation diathermyCommon applications of embolization proce-

dures are as follows:1. Arteriovenous malformations: The aim is to use

permanent embolic material as distally withinthe nidus by super selective catheterizationof all feeding vessels one by one. Towards theend of the procedure when the blood flowdecreases, there is risk of reflux of particulateembolic material into adjacent circulation.This should at all costs be avoided.

2. Arteriovenous fistula: For example carotico-cavernous fistula. Usually a balloon ofappropriate size is placed at the fistulouscommunication. The procedure has minimalrisk and shows excellent therapeutic results.

3. Pulmonary AV fistula: are closed by using coilsor balloons; particulate embolic material ifused can cross and go into coronary or cerebralcirculation with disastrous results.

4. Splenic artery embolization: Proximal splenicembolization is performed to decrease vascu-larity or to occlude a splenic artery aneurysmor an acutely bleeding vessel. Distal splenicartery embolization is performed as analternative to splenectomy. This procedurehas many complications like splenic abscessformation, rupture, necrosis of gastric wall,pancreatitis, etc.

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5. Management of acute gastrointestinal bleeding:Embolization is helpful in upper GIhemorrhage as lots of collaterals exist. In lowerGI bleeding, the complications outweigh theuses of embolization and collateral circulationis very poor. Microcatheters are used for superselective arterial canalization and emboli-zation.

6. Management of hemoptysis: Massive lifethreatening hemoptysis due to tuberculosis,bronchiectasis or malignant disease can beeffectively managed only by embolization ofthe responsible bronchial artery.

7. Preoperative embolization to decrease tumorvascularity is required in highly vasculartumors like nasopharyngeal angio-fibroma,glomus jugulare, renal cell carcinoma, hepatictumors etc.

8. Internal pudendal artery embolization in casesof priapism is preferred over medical manage-ment which is ineffective and over surgicalmanagement which is more often detrimentalto future physiological functioning.

9. Venous embolization: Embolization of testicularveins by balloons or coils is a standardtreatment for varicoceles. Obliteration ofadrenal veins is also at times performed incases of Cushing syndrome secondary toadrenal tumors.

Complications of Embolization

General

General complications of embolization proce-dures are same as those due to the angiographicprocedures or due to contrast reaction.

Specific

Immediate postembolization complications mayvary from mild to severe in clinical importance;pain, and nausea are relatively common whileembolization of adjacent normal structures,adherence of catheter tip to vessel wall by liquid

adhesives and reaction to embolic agents areuncommon but severe reactions.

Delayed reactions include pain, fever, infec-tion, septicemia, tissue infarction and necrosis,extension of the thrombus beyond intended areaand acute renal failure secondary to tissuenecrosis and dehydration.

Any of the above severe reactions maypotentially result in iatrogenic mortality.

VASCULAR THERAPY

Chemoembolization

High concentrations of a chemotherapeutic agentcan be superselectively delivered to one organ bythis technique. The agent may be mixed withiodized oils and particulate embolic material. Thetechnique is used for certain musculoskeletal,genitourinary and gastrointestinal neoplasia.

Constrictor/dilator Therapy

Constrictors like vasopressin or dilators likepapaverine, nitroglycerine, etc. are used duringangiography to improve the quality of vascularopacification. Vasopressin in the dose of 0.1 to0.4 IU/Kg body weight is used to control activeGI bleeding. Dilators may be used as adjuncts toangioplasties in management of stenotic vascularlesions.

Intra-arterial Thrombolysis

Agents like streptokinase, urokinase, pro-urokinase and plasminogen activator cause localthrombolysis when delivered selectively at thesite of thrombus by catheters. Urokinase is beingused in treatment of coronary artery thrombolysis,embolic stroke, and pulmonary embolism withencouraging results. In peripheral arteries andin cases of central venous thrombolysis, thetherapy has been recognized as standard. Certaincases of loculated pleural effusion and peritonitisinstillation of thrombolytic agents locally help indisruption of dense adhesions and septations.

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Transluminal Angioplasty

Transluminal angioplasty is widely used as analternative to surgical angioplasty in differentparts of the body. Initially PTA was used inatherosclerotic narrowing of passage but nowvariety of other lesions like congenital defectsfibromuscular dysplasia, arteritis and otherlesions causing vessel narrowing are also beingmanaged by this technique. The basic techniquein PTA is to place the balloon catheter in the regionof vascular stenosis, dilating the balloon underfluoroscopic control resulting in distention of thestenotic segment, and thereby improving bloodflow. The narrowed segment is crossed with theguidewire and contrast injected to delineate theexact length and position of the lesion which aremarked with radio-opaque markers. The exchangewire is replaced over the diagnostic catheter andballoon catheter is then introduced over it andmanipulated into the stenosis. Careful inflationto predetermine volumes of the balloon must bedone under fluoroscopic guidance.

The balloon inflation is maintained for one totwo minutes. A check angiogram is done toevaluate the effect of dilatation and to look forcomplications, if any. If required repeated balloon

dilatations are done at later dates to achieve betterresults. Main complications of PTA include groinhematomas, distal embolic complications,elevation of intimal flaps, false aneurysm, andarterial rupture. Transluminal angioplasty ofrenal arteries is a standard procedure formanagement of renovascular hypertension.Stenotic lesions resulting from various causes likeatherosclerosis, fibromuscular dysplasia andaortoarteritis are managed by PTA. In experiencedhands, the results of renal angioplasty comparefavourably with surgical results. In lowerextremities, management of arterial stenosiswhich may be isolated or multiple is successfullydone by PTA. In fact, PTA is performed in almostany vessel which if dilated will improve the endorgan perfusion.

Alternatives to PTA or adjuncts to PTA havecome to stay in interventional vascular radiologydue to various reasons.1. Arterial blockage which do not allow the

guidewire in which case a passage needs tobe created by using various newer methodslike application of heat (lasers, radiofrequencyprobes), mechanical energy (atherectomycatheters, atherolytic wires), or thrombolyticagents.

Figs 30.1A and B: Heterogeneous mass with needle tip in mass for biopsy under ultrasound guidance transverse(A) and longitudinal (B) scan of liver shows

A B

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2. Restenosis is generally managed by reducingatheromatous bulk using lasers and also byproviding supportive framework with intra-vascular stents. One or more new deve-

Fig. 30.2: The abscess drainage

lopments in the interventional vascular workis the introduction of angioscopes, which areminiaturized fliexible fiberoptic bundles thatcan be introduced percutaneously to visualizethe arterial lumen.The impact of interventional techniques has

been very profound in clinical medicine. Theintervention is practically applied to every branchof medicine. The greatest benefits of interventionalradiology include reduction of mortality, hos-pitalization costs, and in selected areas isconsidered as the primary modality of choice inthe clinical management of the patient. Thediscriminating application of interventionalradiology can bring benefits in completelyavoiding surgery or postponement of majorprocedures.

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