Contrast radiography

Question 1

What is contras radiography

Answer 1

the use of contrast medium to improve radiographic contrast between soft tissue structures

Question 2

contrast study improves the visualization of:

Answer 2

1) shape, size,location
2) mucosal skeleton
3) luminal contents
4) organ function in some cases

Question 3

What is Positive Contrast Agents and what color do they appear on radiographs

Answer 3

are used to fill or outline a hollow organ

they appear white (are radiopaque to x-rays)

Question 4

give examples of positive contrast agents and what route are they administered (4)

Answer 4

barium- po or emema
gastrografin- po or emema
oral hypaque- po or emema
renografin -IV or urinary catheter

Question 5

what is an angiography

Answer 5

contrast study of the blood vessels

Question 6

what is contrast urography

Answer 6

contrast study of the urinary system

Question 7

What is contrast medium

Answer 7

a substance that is either radiolucent or radiopaque that can be administered to an animal to increase radiographic contrast within an organ or organ system

Question 8

Water-soluble iodine preparation

Answer 8

tir-iodinated compounds supplies as sodium or meglumine salts of iothalamic or metrizoic acids, or a mixture of both

Question 9

name the 6 characteristics of water soluble iodine contrast

Answer 9

1) radiopaque
2) pharmacological inert
3) low in viscosity
4) low in toxicity
5) rapid renal excretion
6) chemically stable

Question 10

name the 3 indications for water-soluble iodine contrast

Answer 10

1) administer IV to visualize the vasculature and or the excretory system
2) administer for UGI or LGI if G.I. perforation is suspected
3) administer via urinary catheter for cystography

Question 11

name 2 contraindications for water-soluble iodine contrast

Answer 11

1) not suitable for myelography or arthrography
2) the rapid transit time through the GI tract and dilution of the agent while it is passing through the GI tract (does not produce as much contrast)

Question 12

what is the preferred contrast agent to use for GI studies

Answer 12

Barium

Question 13

when should you not use barium and why?

Answer 13

if perforation is suspected- it does not get absorbed

Question 14

what could happen if you use water-soluble iodine contrast for myelography or arthrography studies

Answer 14

causes tissue irritation and inflammation when one of these agents is injected into the subarachnoid space (may cause seizure) or into a synovial joint space (cause arthritis)

Question 15

name possible side effects of water-soluble iodine contrast agents (6)

Answer 15

Mild discomfort and nausea (MOST COMMON)
dehydration 
local tissue irritation (causing inflammation)
hypovolemia and shock (RARE)
cardiac arrest (RARE)
allergic reaction (mild-to severe)

Question 16

what is anaphylaxis

Answer 16

an acute allergic reaction to an antigen to which the body has become hypersensitive
treatment epinephrine

Question 17

name 3 Characteristics of of low osmolar contrast agents

Answer 17

nonionic (no salt compound)
fewer side effects
suitable for myelography or arthrography

Question 18

name 3 examples of low osmolar contrast agents

Answer 18

mettixamide
iopamidol
iohexol

Question 19

Name 2 characteristics of barium sulfate

Answer 19

insoluble in water

liquid, paste, or powder

Question 20

name some indications for a GI contrast using Barium

Answer 20

persistent diarrhea or vomiting, regurgitation, dysphagia, intestinal obstruction, chronic weight loss, persistent abdominal pain, abnormal bowel movements, intussusception, rectal mass, abdominal mass, and intestinal stricture

Question 21

what happens if barium leaks into the abdominal cavity, and if it does, what do you do

Answer 21

produces severe peritonitis with high mortality

surgically flushed out within 6-8 hours

Question 22

name the 5 negative agents

Answer 22

room air
CO2
nitrogen
nitrous oxide
O2

Question 23

name 3 properties/ uses of negative agents

Answer 23

used for negative contrast studies
are radiolucent
admin via stomach tube or urinary cath

Question 24

why do you need to use caution when using room air as a negative contrast agent

Answer 24

may cause air embolism in the bloodstream

Question 25

explain double contrast study

Answer 25

both a positive and negative agents are used

best for viewing mucosal detail

Question 26

how long should the patient go without food before a study

Answer 26

12-24 hr

Question 27

how far in advance do you need to perform an enema before a contrast study

Answer 27

2-4 hours

Question 28

if the patient cant be NPO before the study, what can you do to minimize the presence of food in the GI tract

Answer 28

feed low granular food (ex baby food or AD)

Question 29

what sedation is ok to use for contrast studies of the GI tract and why

Answer 29

Phenothiazine tranquilizers (Acepromazine)
-minimal effect of peristalsis

Question 30

Why is atropine contraindicated

Answer 30

slows down peristalsis

anticholinergic effect

Question 31

name 4 side effects of soluble agents administered IV

Answer 31

vomiting
hypotension
allergic reaction
dehydration