1. Contrast Media
in Radiology
what is used and
why
Introduced by
Abdulrahman Alquait
Medical imaging MSc student

2. -What is a contrast medium or
contrast agent?
It is a substance used to
enhance the contrast of
structures or fluids within the
body in medical imaging¹.
¹ contrast agent at Dorland's Medical Dictionary

3. How can we achieve this?
 What type of imaging modality being
used?
 What part of the body being investigated?

4. X-Ray (Plain Films,
Fluoroscopy and CT)
 Beam attenuation.

5. MRI
 T1 & T2 Relaxation times.

6. Ultrasound
 Decreasing reflection or increasing
backscatter of echoes.

7. Types of contrast media in
Radiography.
 Positive Contrast Agents.
 High atomic number.
 (e.g. iodine(53) and Barium(56))
 Negative Contrast Agents.
 Low atomic number.
 (e.g. carbon dioxide (CO2) and air )

8. Positive contrast medium
1. Water insoluble.
 Barium sulphate.
 Barium meals and barium enemas to study
the GI tract.

9. Positive contrast medium

10. Positive contrast medium
2. Water soluble.
 Iodine compounds.
 Intravascular injections.

11. Positive contrast medium

12. Safety
 Barium contrast media are generally safe if no GI
perforation is present.
 Iodinated contrast media are relatively safe.
 Reactions probability²:
o Minor reactions: 12.66% ICM, 3.13% NICM
o Major reactions: 0.2% ICM, 0.04% NICM
²Katayama H, et al. Adverse reactions to ionic and nonionic contrast media. A report from the Japanese
Committee on the Safety of Contrast Media. Radiology. Jun 1990;175(3):621-8