Contrast Studies

Question 1

Indications for contrast studies (4)

Answer 1

1. Used to supplement or confirm information garnered from routine survey radiographs.
2. Lack of contrast in soft tissue makes some diagnosis hard.
3. Contrast medium-substance that is either radiolucent or radiopaque and can be administered to an animal to increase radiographic contrast within an organ or system.
4. Should not be used to replace survey radiography.

Question 2

What are the two general categories of contrast media?

Answer 2

1. Positive contrast agents
2. Negative contrast agents

Question 3

Positive vs Negative contrast agents

Answer 3

Positive
- Iodinated preparations
- Barium sulfate preparations
Negative
- Gases (air)

Question 4

Positive contrast agent’s substances containing what?

Answer 4

Elements of high atomic number that are more radiopaque to x-rays then tissue & bone and have white appearance on a radiograph.

Question 5

Negative contrast agents are…

Answer 5

Gases that are more radiolucent to x-rays than soft tissues and have a black appearance on a radiograph.
- Oxygen, CO2, room air

Question 6

Iodine preparations (3)

Answer 6

1. Most are opaque to x-rays, pharmacologically inert, low in viscosity for rapid intravenous injection, low in toxicity, rapidly excreted by the kidneys, and chemically stable so that no iodine is released in the body.
2. Tri-iodinated compounds- a common component of iodinated positive-contrast media that contains three atoms of iodine per molecule.
   - Well tolerated by body and provide
   excellent contrast.
3. Can be injected into a vascular system for immediate visualization or infused into the bladder.

Question 7

Water soluble contrast media
1. IV injection (3)
2. Oral use (1)
3. CM for intra thecal injection (1)

Answer 7

1. IV
   - Urographin (most popular)
   - Isovist
   - Telebrex
2. PO
   - Gastrographin
3. CM
   - Iohexol (omnipaque)

Question 8

Barium sulfate is completely ____, not diluted or ___ through the intestines. Available in liquid, ___, & ___ that can be reconstituted with water.
If a perforation is present, barium may ___ and be in the body ___.

Answer 8

1. Insoluble
2. Absorbed
3. Paste, & Powder
4. Pass
5. Indefinitely; forever

Question 9

Carbon dioxide has an advantage over room air because is it better ___ into the body when administered into a hollow organ. Room air can cause air ___.
These are ___, relatively ___, and ___ to administer.

Answer 9

1. Absorbed
2. Emboli
3. Inexpensive
4. Safe
5. Easy

Question 10

Double contrast, what is it?

Answer 10

A radiographic contrast technique that uses a combination of both positive & negative-contrast media simultaneously.

Question 11

Three routes GI contrast study substance can be administered

Answer 11

1. PO
2. NG tube
3. Enema

Question 12

Patient prep (6)

Answer 12

1. Food withheld for 12-24hrs
   - If necessary, enema
2. Sedation
   - Avoid drugs with anticholinergic effects (ex: atropine)
3. Scout image to start!!
4. Give the proper amount of contrast agent!
   - Underdosing causes artifact filling defects
5. Avoid getting contrast on fur
6. Rads are carefully timed & labelled to show time from start of study.

Question 13

Esophagram
1. Indications (4)
2. Forms it comes in (3)
3. Image timing

Answer 13

1. Indications
   - Eval esophageal function & morphology
   - Hx of regurg undigested food
   - Acute gagging
   - Dysphagia
2. Forms
   - Barium
   - Barium paste
   - Barium meal (w/food)
3. Immediately after barium is given

Question 14

Esophagram precautions (2)

Answer 14

1. Make sure pt is not able to aspirate barium.
2. If concern about perforation or rupture, iodinated agent should be used instead.

Question 15

Upper GI Study
1. Evaluating what
2. Indications (5)
3. Image timing

Answer 15

1. Evaluating the stomach & small intestines
2. Indications
   - Recurrent & unresponsive vomiting
   - Abnormal bowel movements
   - Suspected foreign body or obstruction
   - Chronic weight loss
   - Persistent abdominal pain
3. Rads taken during passage of agent

Question 16

Upper GI (UGI) study precautions (1)

Answer 16

If perforation or rupture is suspected, barium should not be used, but water soluble-iodine agent.

Question 17

Volume of barium to be administered should be: __mL/kg
High dose is recommended for ___ & small ___ while low dose is recommended for large ___.

Answer 17

a. 6-12mL/kg
b. Cats & small dogs
c. Large dogs

Question 18

Frequency of images needed for GI contrast study (7)

Answer 18

Question 19

What are barium impregnated poly spheres (BIPS)? (4)

Answer 19

1. Created to study gastrointestinal motility.
2. Used to identify areas of intestinal stricture of obstruction.
3. The impregnated spheres are packaged in gelatin capsules, each capsule containing a number of spheres.
4. Usually there will be a mixture of small and large spheres.
   - Helpful when determining whether there is a partial or complete intestinal obstruction.

Question 20

Lower GI (LGI) study
1. Evaluates what? (3)
2. Indications (6)
3. Administration method/route

Answer 20

1. Evaluates the rectum, colon, & cecum
2. Indications
   - Full distension of the large intestine is necessary.
   - Intussusception
   - Rectal mass
   - Abdominal mass
   - Stricture
   - Colonic obstruction
3. Via enema with any three types of contrast mediums

Question 21

Lower GI (LGI) study precautions (2)

Answer 21

1. If perforation or rupture is suspected, barium should not be used, but water soluble-iodine agent.
2. Patient should have all feces and colonic contents removed prior to administration.

Question 22

Urinary contrast study
1. Evaluates what? (4)
2. Indications (7)

Answer 22

1. Evaluates kidneys, ureters, bladder, & urethra.
2. Indications
   - Hematuria
   - Proteinuria
   - Crystalluria
   - Polyuria
   - Isothenuria
   - Dysuria
   - Urinary incontinence

Question 23

T/F: Urinary contrast studies are fairly expensive and have a low diagnostic rate

Answer 23

False! These are relatively inexpensive and have high diagnostic rates