ARRT Scan Protocols 2

Question 1

When performing a CT pulmonary angiography (CTPA), which scan direction is preferred?

Accepted Answer

Caudal to cranial

Answer

Caudal-to-cranial scanning in CTPA ensures the densest contrast bolus reaches the pulmonary arteries during image acquisition.

Question 2

A CT enterography protocol differs from a standard abdominal CT primarily in which way?

Accepted Answer

Use of oral contrast to distend the small bowel

Answer

CT enterography uses large volumes of neutral oral contrast (e.g., VoLumen) to distend and visualize the small bowel mucosa.

Question 3

Which scan phase best demonstrates hepatic metastases that are hypervascular?

Accepted Answer

Hepatic arterial phase

Answer

Hypervascular metastases enhance avidly during the hepatic arterial phase when liver parenchyma enhancement is low, maximizing lesion-to-liver contrast.

Question 4

For a CT-guided biopsy protocol, which parameter is typically reduced to minimize patient dose during the procedure?

Accepted Answer

Tube current (mA)

Answer

Fluoroscopic CT guidance uses low-mA (fluoroCT) settings to reduce cumulative dose while maintaining adequate image quality for needle visualization.

Question 5

A standard high-resolution CT (HRCT) chest protocol uses which reconstruction approach to evaluate interstitial lung disease?

Accepted Answer

Thin slices with high-frequency (sharp) kernel

Answer

HRCT uses thin slices (≤1.5 mm) with a high-spatial-frequency kernel to maximize edge detail of lung parenchyma and airways.

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

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

ARRT Scan Protocols 2