Quiz 3 Flashcards
Contrast reactions generally occur within the first ____ minutes of injection.
5-20
What are a few mild reaction signs and symptoms?
nausea, vomiting, cough, warm feeling, headache, dizziness, shaking, itching…
What are a few moderate reaction signs and symptoms?
tachycardia, bradycardia, hypotension, hypertension…
What are a few severe reaction signs and symptoms?
convulsions, profound hypotension, cardiac arrest
What are the 4 methods of introducing contrast media?
1) ingestion- Oral barium
2) retrograde- retrograde urography
3) intrathecal- myelogram, cystography
4) parenteral- intravenous
What are the five radiographic densities?
air(gas), fat, water, mineral, & metal
What is the purpose of contrast study?
to visualize anatomic structures that are not normally seen on a diagnostic medical image
What is the atomic number of barium?
56
What is the atomic number of Iodine?
53
What is the atomic number of air & gas?
8
What are contrast media used for?
to increase the atomic number of tissues in order to visualize them through increased subject contrast
What does photoelectric interaction result in?
the x-ray photon being totally absorbed and not striking the image receptor
What are the types of contrast media?
negative, positive & specialty
What is an example of a negative contrast media?
air/gas; composed of low-atomic number elements (appears radiolucent on image)
What is an example of a positive contrast media?
barium; composed of higher-atomic number elements (appears radiopaque on image)
Is gadolinium contrast?
no
What color will a negative contrast appear on an image?
black
What color will a positive contrast appear on an image?
white
Why is air not used more often as a contrast media?
low persistence (no control over air
What are some characteristics of a perfect contrast media?
-very-high contrast visualization
-extremely low toxicity to patient
-persistence in patient anatomy until imaging is completed
-low cost
-minimal or no side effects
What are some key contrast characteristics?
-Ability of agents to mix with body fluids
-viscosity
-ionic strength
-persistence in the body
-iodine content
-osmolality
-potential for toxicity
What are some popular contrast choices?
barium sulfate, air/gas, oil-based iodine contrast agents, water-soluble iodine contrast agents
For barium studies of the GI tract, you would use what kind of contrast for suspected perforations?
water-soluble
What are the two ions on Ionic contrast agents?
Anion and Cation
