Radiology Flashcards
LAT
Lateral (regular XR image)
Role of diagnostic imaging in medicine
Diagnostic imaging is used to diagnose a wide variety of conditions (orthopedic, vascular, pulmonary, GI, obstetric, urological…)
Ionizing radiology (examples)
Shoots ionizing radiation through the patient and onto photosensitive surface to create an image
X-ray, flouroscopy, computed tomography (CT scan)
Magnetic Resonance Imaging
Uses very strong magnetic fields and radio-frequency to produce energy in the body’s stored HYDROGEN ATOMS
This info is detected to generate 2D and 3D images
Best for diagnosis of nerve compromise, ligament outs injury, vascular insult, and operative planning
Nuclear medicine
Radioactive isotope in unstable form is put into patient
Isotopes are attracted to specific structures/tissues where the rate of decay is detected by isotope decay detectors
SPECT- single photon emission computed tomography
PET- positron emission tomography
Nuclear stress tests, thyroid scans..
Ultrasonography
Ultrasound probes use acoustic energy and measure the time it takes for ultrasound waves to leave and return to ultrasound strobe.
Faster/higher quality waves= brighter image
5 basic densities
Air- blackest on XR/CT/US
Fat- lighter shade of gray (CT best)
Soft tissue or fluid- dense=grayer, less dense= blacker (CT best)
Calcium- mostly in bones (XR shows inside better/ CT shoes outline better)
Metal- whitest/foreign (XR best)
PA v AP
PA from behind
AP front
CT with vs CT without vs CTA
CT without- no contrast-bones/ FOs
CT with- with IV contrast- organs
CTA- with IV contrast timed for arterial phase
MRI without
MRA
MRV
MRI without- no contrast- soft tissue,ligaments, bones
MRA- arterial phase contrast
MRV venous phase contrast
What density is brighter white
Increased density
Flow void
Absence of contrast or fluid which is normally there
What would you use for bone/calcium and foreign bodies
Usually Xray- or CT without contrast
What does IV contrast help identify
Organs/tumors/masses/ bleeding
Arteries and veins with special timing (CTA)
It enhances the appearance of organs and will highlight areas of inflamed or infracted tissue
Stop and look at common clinical use chart/ safety limitations on ppt
Did you look
CT without
no contrast - shows bones and foreign objects
CT with
with IV contrast - highlights organs
CTA
with IV contrast, timed for arterial
MRI without
no contrast, soft tissue, ligament and bone
MRA
arterial phase contrast - arteries
MRV
venous phase contrast - veins
increased density
brighter white
decreased density
grayer
mixed density
areas of high and low densitty
attentuation
increased or decreased - same as density
flow void
absence of contrast or fluid that is normally in a structure
Detect bone, calcium, foreign bodies
xray or CT without contrast
detect organs, tumors, masses, bleeding
US or CT IV contrast to enhance organs and inflamed tissue
detect arteries and veins
IV contrast with special timing in CT
Why use Xray?
fractures, dislocations, pneumonia, intestinal obstruction
Disadvantage xray
radiation, poor internal organ issue
Why use CT?
fractures, dislocation, organ function, infection, inflammation, bleeding, vascular tumors
gold standard for diagnoses
Disadvantage CT
radiation exposure, contrast allergy
Why use MRI
nervous, vascular, oncologic, ligamentous, bony inection and kids. Greatest accuracy most dx
Disadvantage MRI
high cost, long duration, decrease comfort
Why use US?
superficial structures, gallbladder, fetal, vascular, superficial infection, abdominal organ, trauma, heart
Good if experienced user
Why use nuclear medicine
function of organs, metabolic activity structures, perfusion organs. Good for certain diagnoses
Disadvantage of NM
radiation exposure, expensive, special equipment, slow
