ARRT Contrast Media 3

Question 1

What physiologic mechanism underlies contrast-induced nephropathy (CIN)?

Accepted Answer

Renal medullary ischemia and direct tubular cell toxicity from contrast

Answer

CIN results from renal medullary vasoconstriction causing ischemia combined with direct cytotoxic effects of contrast on tubular epithelial cells.

Question 2

A 55-year-old patient develops generalized urticaria approximately 5 minutes after IV contrast injection. This reaction is best classified as:

Accepted Answer

A mild acute allergic-like (anaphylactoid) reaction

Answer

Generalized urticaria without systemic involvement (no bronchospasm or hypotension) represents a mild acute allergic-like reaction, typically treated with antihistamines.

Question 3

For a CT abdomen/pelvis with IV contrast, what is the typical scan delay after contrast injection to capture the nephrographic phase of the kidneys?

Accepted Answer

80–120 seconds

Answer

The nephrographic phase occurs approximately 80–120 seconds post-injection, when the renal cortex and medulla enhance uniformly, optimizing detection of renal masses.

Question 4

Which patient condition is an absolute contraindication to intravascular iodinated contrast media administration?

Accepted Answer

Previous severe anaphylactic reaction to iodinated contrast without premedication

Answer

A prior severe anaphylactic contrast reaction is a contraindication unless the patient is premedicated and the benefit outweighs the risk; the radiologist must be involved.

Question 5

What is the recommended IV injection rate range for a CT angiography of the aorta using a power injector?

Accepted Answer

3.0–6.0 mL/sec

Answer

CTA of the aorta typically requires injection rates of 3–6 mL/sec to achieve sufficient intravascular iodine concentration for diagnostic arterial enhancement.

(ARRT) American Registry of Radiologic Technologists Computed Tomography Certification Practice Test

(ARRT) American Registry of Radiologic Technologists Computed Tomography Certification Practice Test

ARRT Contrast Media 3