Contrast Media

Question 1

Reason for use

Answer 1

Visualisation of soft tissues

Question 2

Define positive cm (2)

Examples (2)

Answer 2

Contain elements of high atomic number
Radio-opaque (white)

Barium
Water soluble iodine compounds

Question 3

Define negative cm (2)

Examples (4)

Answer 3

Gases are radiolucent due to low density
Appear black

Room air
O2
CO2
N2O

Question 4

Indications for barium use (3)

Contraindication of use (1)

Answer 4

Gastrointestinal studies
Megaoesophagus
FBs

Suspected perforation

Question 5

Advantages of barium (3)

Answer 5

Non-toxic
Well-tolerated
Insoluble

Question 6

Disadvantages of barium (2)

Answer 6

Foreign body reaction if leaks

Pneumonia if aspirated

Question 7

Properties (2). and indications (2) of hypertonic water-soluble iodine

Answer 7

Hypertonic
High osmolarity/OP
- increased pressure through fluid drawing

Lower urinary tract
GIT

Question 8

Side effects of hypertonic iodine (4)

Answer 8

If given IV

• hypotension
• anaphylaxis

If given conscious

• whining
• retching

Question 9

Properties e of lower osmolar ionic water soluble iodine (2)

Answer 9

Fewer side effects and better GIT contrast than hypertonic

Question 10

What can lower osmolar non-ionic soluble iodine be used for and why

Answer 10

Myelography

- will not cause increase in pressure through fluid drawing