Key Concepts Of Contrast Agents

Question 1

2. Contrast agents fill a structure with material that has a different density than that of the structure. When the agent is a lower density then the structure it is referred to as a?

Answer 1

Negative agent

Question 2

3. Two tissues must differ by at least _____ hounsfield units to be visibly different on a CT scan.

Answer 2

20

Question 3

4. _____________ is a property of intravascular contrast media that refers to the number of particles in solution, per unit liquid, as compared with blood.

Answer 3

Osmolality

Question 4

5. HOCM will have ________times the osmolality off blood

Answer 4

7

Question 5

6. LOCM has ________ the osmolality of blood

Answer 5

Twice

Question 6

7. Contrast media that is ____________ has the same osmolality as blood

Answer 6

Isomolar

Question 7

8. ___________ is a physical property of intravascular contrast media. Thickness or friction of fluid as it flows .

Answer 7

Viscosity

Question 8

9. The most common formula for calculating the dose of intravascular contrast for pediatric CT studies is:

Answer 8

2m/kg

Question 9

10. Contrast media reactions can be broadly categorized as either _________ or _______________

Answer 9

Chemotoxic or idiosyncratic

Question 10

11. To reduce the risk of CIN( contrast induced nephrotoxcity) what 4 things should you do

Answer 10

1- Use LOCM or IOCM
2- hydrate the patient
3- Use the smallest dose available
4- Allow 48 hours to elapse between contrast procedures

Question 11

12. For barium sulfate exams: for most examinations a minimum of ______ml of barium given ____ mins to _____ hours before scanning.

Answer 11

500

45 mins

2 hours

Question 12

13. TRUE OR FALSE: you should always give 200ml right before scanning to fill the stomach and proximal small bowel

Answer 12

True

Question 13

14.barium sulfate should not be given if ____________ of the gastrointestinal tract is suspected

Answer 13

perforation

Question 14

15. Barium leaking into the peritoneal cavity is referred to ________. Which can cause a serious mortality rate

Answer 14

Barium peritonitis

Question 15

1. Contrast agents fill a structure with material that has a different density than that of the structure. When the agent is a higher density then the structure it is referred to as a?

Answer 15

Positive agent