Computed Tomography Test CT Anatomy and Clinical Applications 2

Question 1

Which CT finding is characteristic of renal cell carcinoma (RCC)?

Accepted Answer

Hypervascular solid renal mass with arterial phase enhancement ≥20 HU above baseline

Answer

RCC is highly vascular and shows significant enhancement (typically >20 HU increase) on arterial phase CT, distinguishing it from cysts and benign lesions.

Question 2

What is the CT appearance of a renal angiomyolipoma (AML)?

Accepted Answer

Intralesional fat with HU values below −10 (macroscopic fat)

Answer

Classic AMLs contain macroscopic fat (HU < −10), which is pathognomonic and allows diagnosis without biopsy in the appropriate clinical context.

Question 3

On a CT urogram, which phase of imaging is used to evaluate the collecting system, ureters, and bladder?

Accepted Answer

Excretory (delayed) phase at 5–10 minutes

Answer

The excretory phase captures opacified urine within the renal collecting system, ureters, and bladder after contrast is filtered and excreted by the kidneys.

Question 4

Which structure separates the right and left lobes of the liver and is identified by an imaginary line on CT?

Accepted Answer

Main lobar fissure (Cantlie's line) from the gallbladder fossa to the middle hepatic vein

Answer

Cantlie's line is an imaginary line connecting the gallbladder fossa anteriorly to the middle hepatic vein posteriorly, dividing the liver into right and left functional lobes.

Question 5

A 'free air' (pneumoperitoneum) sign on CT of the abdomen following bowel perforation is best identified on which type of CT window?

Accepted Answer

Lung window settings applied to abdominal images

Answer

Free intraperitoneal air has the same HU as intraluminal air (−1000 HU) and is most conspicuous on lung window settings (wide width, low level) that make small gas pockets visible.

Computed Tomography Test Practice Test

Computed Tomography Test Practice Test

Computed Tomography Test CT Anatomy and Clinical Applications 2