Computed Tomography Test CT Contrast Media and Patient Preparation

Question 1

What is the most common type of iodinated contrast media used for CT examinations?

Accepted Answer

Non-ionic, water-soluble iodinated contrast

Answer

Barium sulfate suspension

Answer

Ionic high-osmolar contrast

Answer

Gadolinium-based contrast

Question 2

Which serum creatinine-based calculation is most commonly used to screen for contrast-induced nephropathy risk before CT?

Accepted Answer

eGFR (estimated Glomerular Filtration Rate)

Answer

BUN/creatinine ratio

Answer

Urine specific gravity

Answer

Creatinine clearance via timed urine collection

Question 3

At what injection rate (mL/sec) is intravenous contrast typically administered for a CT pulmonary angiography (CTPA)?

Accepted Answer

3–5 mL/sec

Answer

0.5–1 mL/sec

Answer

10–15 mL/sec

Answer

Less than 0.5 mL/sec

Question 4

Which medication must be withheld 48 hours before and after iodinated contrast administration in patients with renal impairment?

Accepted Answer

Metformin

Answer

Aspirin

Answer

Lisinopril

Answer

Atorvastatin

Question 5

What is the typical oral contrast agent used to opacify the GI tract during abdominal CT?

Accepted Answer

Dilute barium or water-soluble iodinated contrast

Answer

Gadolinium

Answer

Iohexol injection

Answer

Normal saline

Question 6

Which phase of contrast enhancement is best for evaluating hypervascular liver tumors such as hepatocellular carcinoma (HCC)?

Accepted Answer

Arterial phase (25–35 seconds post-injection)

Answer

Portal venous phase (60–70 seconds)

Answer

Delayed phase (3–5 minutes)

Answer

Non-contrast phase