contrast Flashcards
(26 cards)
what is contrast?
substance used that can be instilled or injected into the body
why is contrast used?
when imaging anatomic tissues that have low subject contrast
how does contrast type change absorption characteristics?
by either increasing or decreasing the attenuation of the X-ray beam
is barium contrast positive or negative?
positive contrast
radiolucent appears what on film?
dark
what is the most common radiolucent contrast?
air and carbon dioxide
how does radiopaque contrast appear on film?
white
what is the most common contrast for GI ?
barium sulfate
what are cons of using barium?
difficult to swallow, irritate the colon, cause cramps, edema, peritonitis, constipation, difficult to eliminate
what is a con of using iodides?
highly toxic, fluid balance of the body may be severely affected
where is ionic contrast used?
IVP- kidneys, ureters, and bladder
what is beneficial about high osmolality?
provides greater contrast but more increases toxicity and viscosity
what is beneficial about non ionic contrast?
low osmolality
how long do gallbladder tablets take to absorb?
12-24 hours
what is urography?
timed sequence of radiographs taken as the contrast moves through the urinary system, post void
what is myleography?
water soluble material requires images immediately after injection; lumbar puncture; L4
less serious reactions to contrast?
nausea, diarrhea, dry mouth, headache, anxiety chills,
serious reactions?
anaphylactic shock, pulmonary edema, asthma attack, cardiac arrest
how are aqueous solutions absorbed?
in the bloodstream, excreted through the kidneys
what is aqueous based iodine?
iopamidol, iohexol
what are cons to iodinated contrast?
can cause discomfort to patient; allergies
what is a power injector?
a medical device to deliver specific amounts of contrast agent at specific flow rates
what is DCBE?
double contrast barium enema
what is an air arthrogram?
injection of air into a joint cavity allows the cartilage covering the ends of the bones of visualised
