Introduction

Question 1

Imaging Techniques

Answer 1

o	Utilize Ionizing Radiation
	Plain films 
•	Chest x-ray, abdominal film, extremity
	Fluoroscopy
•	Upper GI series or barium enema
	CT
•	Cat scanning
•	Looking at multiplanar images
	Nuclear Medicine
•	Given patient radionucleotide in order to better observe a particular area and its function
	Mammography
o	Don’t Utilize Ionizing Radiation (good thing)
	MR
	US

Question 2

Xrays

Answer 2

o X-rays are basically high energy photons that are similar to visible light EXCEPT:
 Higher energy and shorter wavelength than visible light
o X-rays collected on:
 Photosensitive film – permanent
 Digital imaging plate – permanent
 Fluoroscope - temporary
o Can’t actually see the x-rays themselves just the images they form
o Image seen is part of the patient that blocks the x-ray beam
o Denser the material, more difficult it is for beam to penetrate
 Air < fat < soft tissue < bone < metal
o X-rays don’t always leave the body
 X-rays can cause damage to DNA, affecting future cells, causing mutations, or cell death
 Exposure is cumulative – must assess risk/benefit
o X-rays can be diagnostic or therapeutic
 Muscle, solid organs (thorax/heart/liver/spleen ect.)

Question 3

Chest x-ray Views

Answer 3

o The chest x-ray is the still the most common study done – patient should take deep breath in and hold it
 X-ray always named for direction of the beam
 Left - Patient positioned for posterior-anterior (PA) view of chest
 Right – patient positioned for anterior-posterior (AP) view – often done at bedside

Question 4

Chest xray features to consider

Answer 4

o	Symmetry – compare left and right
	Important 
	Bilateral markers – ribs, lung
	Unilateral/midline – trachea, heart
o	Location
	Upper, middle, lower lobes 
	Anterior/posterior
	Something in the middle
o	Size – too small or too large
o	Numbers  - Single or multiple
o	Borders - Smooth or irregular
o	Density - Solid, cystic, fluid filled, air filled

Question 5

Fluoroscopy

Answer 5

o Live images obtained while a procedure/maneuver is being performed
 x-ray beam hits patient and goes to fluorescent plate
• The image is intensified
 Upper GI series w/ barium

Question 6

Ultrasound

Answer 6

o High frequency sound wave sent into tissue and reflected echoes create an image
o An ultrasoundographer will use transducer over interest area
o Two types of images
 Real time images - Show active motion
• Check for cardiac activity
 Doppler images - checking for speed and flow in vessels
o Densities
 Black = anechoic (no echoes), low density, fluid
 Grey = hypoechogenic, medium density, soft tissue
 White – hyperechoic, high density, calcium

Question 7

Features to look for with Ultrasound

Answer 7

o Thorax – heart-wall thickness, motion, valves
o Abdomen – liver, spleen, pancreas, kidneys, masses, solid, cystic, stones
o Pelvis – ovaries, uterus, fetus, prostate, masses
o Vasculature – aneurysms, peripheral vessels (deep vein thrombosis)

Question 8

CT

Answer 8

o Gantry – donut portion of machine
 Series of small x- ray sensors which rotate as the study is taking place
 Can get coronal, sagittal and axial images - 3D reconstructions are made
o Densities - Determined by Hounsfield Units
 Can put numbers in machine that will help us determine density at specific location
• Can help with determining cyst from tumor
 Low Attenuation – black (air)
 High Attenuation – white (bone)
 CT vs. Plain Film have similar densities

Question 9

CT advantages and disadvantages

Answer 9

o	Advantages
	Almost all anatomical areas visible
	Use with or without oral/IV contrast
	Quick
	Can differentiate different densities
o	Disadvantages
	ionizing radiation
	cost
	not available at all institution 
	may be hampered by metal/star artifact

Question 10

CT/MR features to look for

Answer 10

o Asymmetry
o Mass effect or masses
o Midline shift
o Fluid collections

Question 11

CT vs. MR

Answer 11

• CT advantages – availability, speed, cost, can detect calcium and acute bleeds easily, accommodates patient monitoring equipment
• MR advantages – multiplanar images, greater gray/white differentiation, more detailed anatomy, better visualization of subacute and chronic bleeds and spinal compression

Question 12

MR

Answer 12

o Uses magnetic field and radiofrequency to obtain an image
o Magnetic field causes protons to line up in a certain configuration
o A high frequency magnetic pulse is shot through body and this normal configuration is shifted
o Precautions – strong magnetic field
 Make sure patient doesn’t have
• Aneurysm clips
• Pacemaker
• Artificial valves
• Metal shards in eyes or anywhere else

Question 13

MR Techniques

Answer 13

 T1 and T2 can be easily differentiated by looking for something of water density
 Fluid will be dark on T1 and bright on T2

Question 14

Interventional Radiology

Answer 14

o diagnostic or therapeutic
o Procedures – angiography (vessel visualization), tube, line, stent, device placement, biopsy
o Complications - hemorrhage, clot and infection
o Will often place dye to better visualize area
o Previously obtained x-rays can help reveal abnormalities in anatomy
o Patients may complain of metallic taste or warm-flush feeling
 May also complain of nausea
 Ask about prior administration, allergies, and renal function

Question 15

Nuclear Medicine

Answer 15

o Small amount of radioactive isotope is administered to patient - intravenously, inhaled or swallowed
 Same amount of radiation as chest x-ray
 Isotope is excreted in urine
 Images taken initially and then several hours later when radioactive isotope is absorbed

Question 16

Types of Nuclear Scans

Answer 16

Bone scan – will have increased uptake in:
 Metastatic disease
 Acute fractures
 In growth plates - children are not great candidates for bone scans because of this

Gallium – if concerned for infection
 Hepatobiliary – looking for liver or gallbladder disease
 Liver/spleen scans – shape, size, position of organs
 Thyroid scans – special instructions – discontinue thyroid medication, no IV contrast, no seafood, no iodine containing products
 V/Q – ventilation perfusion scan
• If concern of pulmonary embolus
• Will give patient Xenon gas to breath in to see if their lungs are totally functional at alveoli
• TC99m is injected intravenously so we can see vascular supply of lungs too

Question 17

Mammography

Answer 17

o Film/screen technique – lower radiation dose
o 2 views – craniocaudal, cephalad
o Initial screening at age 40 unless high risk or symptomatic
o Follow up with ultrasound, MR