INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of...
-
Upload
bertina-summers -
Category
Documents
-
view
255 -
download
10
Transcript of INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of...
![Page 1: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/1.jpg)
INTRODUCTION to MEDICAL IMAGINGOksana H. Baltarowich, MD
Professor Radiology
Department of Radiology
Jefferson Medical College
![Page 2: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/2.jpg)
NO DISCLOSURES
![Page 3: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/3.jpg)
Objectives
• List the main diagnostic imaging modalities used in medical practice
• Explain the basic principles of the main types of imaging modalities
• Describe advantages of the different imaging techniques
• List disadvantages of the different imaging techniques
![Page 4: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/4.jpg)
Medical Imaging
X-Rays: ionizing radiationRadiographyCT scan (Computed Tomography)
Gamma raysNuclear Medicine
Sound wavesUltrasound
Magnetic fields/radiofrequency wavesMRI (Magnetic Resonance Imaging)
![Page 5: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/5.jpg)
Who Does Imaging?
• Radiologist– Consultant: Diagnostic, Subspecialties– Interventionalist
• Radiation Oncologist: Treatment planning• Cardiologist: Invasive, Non-Invasive• Vascular Surgeon: Endovascular procedures• Other specialists
– Usually for procedure guidance (Ob-Gyn, Internal medicine, Orthopedics, etc.)
![Page 6: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/6.jpg)
Training
• Radiologist– Mandatory clinical internship– 4 years general radiology residency– Physics, radiation protection, radiobiology,
technology, diagnosis, anatomy, pathology, physiology, etc.
– 1 year fellowship in subspecialty
• Cardiologist, vascular surgeon, others– intergrated into training program
![Page 7: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/7.jpg)
Radiography
X-rays
![Page 8: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/8.jpg)
X-rays
• Dr. Wilhelm C. Roentgen at University of Wurzburg, 1895– Discovered and
named X-rays• Awarded first Nobel
Prize for Physics in 1901
![Page 9: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/9.jpg)
X-Rays• Radiography
– Plain film radiography - without added contrast material
– Contrast radiography – with contrast material
– Computed Radiography (CR)– Fluoroscopy: done in real time
• Barium studies: Upper GI, BE• Angiography
• CT (Computed Tomography), aka CAT scans (Computer Assisted Tomography)
![Page 10: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/10.jpg)
Radiographs• Electromagnetic waves (X-rays) are produced in an
X-ray tube by converting electrical energy into an electromagnetic wave• Electrons are accelerated from an electrically
negative cathode to a positive target anode• Energy is released and converted into heat and
X-rays
![Page 11: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/11.jpg)
Radiographs• Images produced by electromagnetic waves
(X-rays)• produced by an X-ray tube• pass thru the body• are absorbed by the different tissues• reach the film and • expose the film
Radiographic cassette
![Page 12: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/12.jpg)
Computed Radiography (CR)
• Produces digital radiographic images• Instead of film, a phosphor plate is exposed
to X-rays• Laser beam scans the plate• Light is released, intensified and converted to
electron stream• Converted by computer into digital image• Viewed on a monitor• Transferred over networks
![Page 13: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/13.jpg)
Radiographic Densities
• Air Black• Fat Dark
gray• Water* Light
gray• Bone White
• Calcium White• Metal Very white*Water=soft tissue: organs, muscles, blood vessels, masses
![Page 14: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/14.jpg)
Radiodensity
Radiodensity is a function of:
1. Composition (atomic number)
2. Thickness of object
3. Strength of X-ray
Radiodensity as function of thickness of object
Radiolucencyis the opposite
![Page 15: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/15.jpg)
Radiodensity• If an object is thick and dense, less radiation
passes thru to reach the film– Radiodense– Film is underexposed and stays light
• Air gives no obstruction to X-rays – Radiolucent– Film gets overexposed and turns black
• Bone absorbs radiation, less radiation reaches the film– Film is underexposed and stays white
![Page 16: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/16.jpg)
Abdominal Radiograph: KUB
• Air Black• Fat Dark
gray• Water Light
gray• Bone White
• Calcium White• Metal Very white
*Water=soft tissue: organs, muscles, blood vessels, masses
![Page 17: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/17.jpg)
Radiographs
Composed of overlapping radiodensities, overlapping shadows
Tissues stacked in front of each other
Need 90 degree projection for anatomic placement
![Page 18: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/18.jpg)
RadiographsPerpendicular projections are necessary to
localize structures in the body
![Page 19: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/19.jpg)
Roof fell on patient
![Page 20: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/20.jpg)
Patient Position for Chest X-Ray
Posteroanterior (PA) Chest: X-ray beam passes from posterior to anterior
RT LT
![Page 21: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/21.jpg)
Erect Position
Free intraabdominal air: Pneumoperitoneum
![Page 22: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/22.jpg)
Portable Films
• Patient is too ill to go to Radiology Department
• Less optimal• Portable X-ray unit • X-ray film is behind
patient • X-rays pass through
patient from anterior to posterior
![Page 23: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/23.jpg)
Abdominal Radiographs
• Erect/upright• Supine• Prone• Decubitus• Oblique/rotated
![Page 24: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/24.jpg)
Contrast Radiography• Injection, ingestion or placement of radiopaque material into the
body for contrast enhancement• Oral, rectal contrast: Barium, gastrograffin
![Page 25: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/25.jpg)
Contrast RadiographyAngiography
![Page 26: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/26.jpg)
Caution: Radiation Exposure
• Radiation workers follow safety guidelines
• Women of child-bearing age should be questioned about possibility of pregnancy before abdominal X-ray.
• Ask about LMP and check pregnancy test, if in doubt.
![Page 27: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/27.jpg)
Caution: Pregnancy
![Page 28: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/28.jpg)
Computed TomographyX-rays
![Page 29: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/29.jpg)
Computed Tomography• Ionizing radiation used to obtain cross-sectional
images of the body• Table moves through large donut-shaped scanner
– Fast moving X-ray tube (thin X-ray beam rotates)– Numerous electronic detectors
• Rapid acquisition of images• Contrast agents necessary for most scans
– Oral– Intravenous iodinated
![Page 30: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/30.jpg)
Computed Tomography• Multidetector CT scans
– Advancement from tomographic imaging (slices) to volume imaging
– Produce a volume of data that can be manipulated– Reconstruct at 1-10 mm increments– Axial, sagittal, coronal, 3D reconstructions
![Page 31: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/31.jpg)
Computed TomographyCoronal and sagittal reconstructions
![Page 32: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/32.jpg)
Computed Tomography
• Large field of view– Entire cross-section of body
• Improved differentiation of soft tissue densities• Excellent spatial resolution
– Small 3-4 mm lymph nodes, vessels• Automated scanners
– Less operator-dependent• Ultra-fast scanners
– Suspended respiration– Less bowel motion artifact– Trauma
ADVANTAGES
![Page 33: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/33.jpg)
CT Density Differentiation
![Page 34: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/34.jpg)
CT of the Female Pelvis
• Exposure to ionizing radiation• Allergic reactions to intravenous contrast
– Mild to severe (anaphylaxis) • Contrast nephropathy
– May cause renal failure– Caution in diabetics with nephropathy
• Problems of dehydration– Cautious use in multiple myeloma, sickle cell
disease • Soft tissue differentiation not as good as MRI
DISADVANTAGES
![Page 35: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/35.jpg)
CT WindowsWindowing displays the image in differing shades of grayCorrespond to brightness and contrast
Soft tissue window Lung (air) window
![Page 36: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/36.jpg)
CT Windows
Soft tissue window Bone window
Windowing displays the image in differing shades of grayCorrespond to brightness and contrast
![Page 37: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/37.jpg)
CT Diagnosis• Trauma
Shattered spleen Fractured sacrum
![Page 38: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/38.jpg)
CT Diagnosis• Pulmonary embolism• Intravenous contrast material is necessary
![Page 39: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/39.jpg)
CT Diagnosis• Angiography• Bowel disorders
Aortic aneurysm Perforated sigmoid diverticulitis
![Page 40: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/40.jpg)
CT 3D Volume Rendering
Aorta, plaque Aortic arch
CT Angiogram
![Page 41: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/41.jpg)
Diagnostic Ultrasound
Sound Waves
![Page 42: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/42.jpg)
Diagnostic Ultrasound• Audible sound 20Hz-20KHz• Ultrasound >20Hz• Medical ultrasound 1-20
MHz• Transducer sends high
frequency sound waves into the body and gathers their reflections (echoes)
• Converts echoes into electronic signals
• Displays images on a monitor
![Page 43: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/43.jpg)
Diagnostic Ultrasound• Sound travels very well through fluid• Ultrasound is good for anything containing
fluid, as long as there is no interference for the sound beam to reach the fluid
![Page 44: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/44.jpg)
Diagnostic Ultrasound• Interferences to sound waves: air, bone,
metal, thick tissues, deep structures
![Page 45: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/45.jpg)
Diagnostic Ultrasound
• Multiplanar imaging in real-time• Non-invasive, safe, no radiation
– Pregnancy, Pediatrics• Relatively inexpensive• Widely available• Portable, bedside• Good contrast of tissue
layers in many organs
ADVANTAGES
![Page 46: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/46.jpg)
Diagnostic Ultrasound
• Good contrast of tissues layers
ADVANTAGES
![Page 47: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/47.jpg)
Pelvic Ultrasound versus CT
Ultrasound
CT
Ovarian Neoplasm
![Page 48: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/48.jpg)
Diagnostic Ultrasound
• Relatively small field of view• Operator dependent: inconsistent reproducibility • Depends on sound penetration
– Air, bone, obesity
DISADVANTAGES
![Page 49: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/49.jpg)
Diagnostic Ultrasound
• Trade-off between depth (beam penetration) and resolution– For deeper penetration need lower frequency
transducers, resulting in lower resolution
DISADVANTAGES
3.5 MHz 12 MHz
![Page 50: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/50.jpg)
Doppler Ultrasound• Evaluation of blood flow
– Patency, direction, character of flow in vessels– Vascularity in a mass
Carotid artery Testicular flow
![Page 51: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/51.jpg)
FD = (FR - FT ) = 2 • FT • v • cos
c
v
FT
FR
The Doppler EquationThe relationship of Doppler frequency shift
to velocity of a moving object
C =1540m/sec speed of sound in tissues
![Page 52: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/52.jpg)
3D Ultrasound
1st Trimester fetus 3rd Trimester fetus
![Page 53: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/53.jpg)
Magnetic Resonance ImagingMagnetic fields
Radiofrequency waves
![Page 54: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/54.jpg)
Magnetic Resonance Imaging
• Patient placed inside a large cylinder-shaped magnet
• Radio waves 10,000 - 30,000 stronger the earth’s magnetic field are sent thru body
• Nuclei of body’s (hydrogen) atoms shift position
• As they move back they send out radio waves
• Scanner detects the signals• Creates image based on
location & strength of signals
![Page 55: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/55.jpg)
Magnetic Resonance Imaging
• Large field of view– Cross-section of entire body– Volume imaging (from tomographic imaging,
slices)• No ionizing radiation as with CT • Not as operator dependent as ultrasound• Much fewer contrast allergies and less risk of
contrast nephropathy than with iodinated agent used in CT
• Excellent contrast resolution among tissue layers, esp. fat, hemorrhage
ADVANTAGES
![Page 56: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/56.jpg)
Magnetic Resonance ImagingLarge field of view
Excellent Contrast Resolution
![Page 57: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/57.jpg)
Ultrasound vs CT vs MRIField of View, Excellent Contrast Resolution
Ultrasound
MRI CT
![Page 58: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/58.jpg)
Magnetic Resonance Imaging• Exquisite neuroanatomical detail• Musculoskeletal disorders• Cardiovascular
![Page 59: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/59.jpg)
Magnetic Resonance Imaging
• Motion related artifacts– Bowel peristalsis– Respiratory motion
• Cost $$$• Image production is time-consuming with
complicated protocols & scan time• Intravenous contrast is often required to
improve tissue differentiation• Claustrophobia• Obesity
DISADVANTAGES
![Page 60: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/60.jpg)
Magnetic Resonance Imaging
• Contraindication in patients with ferromagnetic metallic objects, implants, foreign bodies:– Metallic fragments in eye– Cochlear implants– Cardiac pacemakers– Brain aneurysm clips– Certain heart valves– Neurological stimulators
• Orthopedic devices are not harmful to patient, but create artifacts
• Intrauterine devices are safe
METALLIC OBJECTS
![Page 61: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/61.jpg)
Nuclear ImagingGamma waves
![Page 62: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/62.jpg)
Nuclear Medicine• Uses small amounts of radioactive material
for diagnosis and treatment • Molecular Imaging: images reflect biological
processes that take place at the cellular and subcellular levels
• Evaluates physiological function rather than anatomic structure
• Uses radiopharmaceuticals: agents that have trace amounts of radioactive atoms attached
• Radiation emitted from the patient is imaged by a gamma camera, SPECT or PET scanner
![Page 63: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/63.jpg)
Nuclear Medicine Applications
• Oncology: tumor localization, staging, metastases
• Cardiology: myocardial perfusion scans• Gastrointestinal: acute cholecystitis, biliary
tract, GI bleeding• Pulmonary: ventilation, perfusion• Infectious disease: localize infections (subtle)• Therapy, e.g. I-131 for thyrotoxicosis, thyroid
cancer
![Page 64: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/64.jpg)
Common Radionuclides
• Intravenous administration– Technetium-99m– Iodine-123 and 131– Thallium-210– Gallium-67– Fluorine-18 Fluorodeoxyglucose– Indium-111 labeled leukocytes
• Inhaled gaseous/aerosol radionuclides– Xenon-133– Krypton-81m– Technicium-99m gas
![Page 65: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/65.jpg)
Gamma Camera
![Page 66: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/66.jpg)
Bone Scan: Metastases
![Page 67: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/67.jpg)
PET Scan: Cancer Detection
• Positron Emission Tomography
• 18F-fluorodeoxyglucose (FDG)
• Primarily used for diagnosis, staging & monitoring of cancers: lung, breast, cervical, colorectal, esophagus, head & neck, lymphoma, melanoma
Lymphoma pre and post chemotherapy
![Page 68: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/68.jpg)
PET-CT ScannerCombined PET scanner and CT scanner
![Page 69: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/69.jpg)
PET-CT• Imaging by “fusion” of anatomy and physiology• Superimposition of the anatomic images of a CT scan
and the co-registration of physiologic uptake of a radionuclide agent (molecular imaging)
![Page 70: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/70.jpg)
PET-CT ScansFusion imaging: Lingular mass
CT PET PET-CT
![Page 71: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/71.jpg)
Summary
• Medical imaging is essential for medical practice
• Interpretation of various imaging modalities requires training and experience
• Radiologist specializes in various imaging modalities– Consultant– Interventionalist
![Page 72: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/72.jpg)
Sample Question
Of the following imaging modalities, which test has the least harmful effects for a fetus?
a. CT
b. Ultrasound
c. MRI
d. Nuclear medicine
![Page 73: INTRODUCTION to MEDICAL IMAGING Oksana H. Baltarowich, MD Professor Radiology Department of Radiology Jefferson Medical College.](https://reader033.fdocuments.net/reader033/viewer/2022061612/5697bff11a28abf838cbb042/html5/thumbnails/73.jpg)
Thank you for your attention!