CAMRT Imaging Equipment and QC Questions and Answers 3

Question 1

What is the primary safety concern with portable X-ray equipment on hospital wards?

Accepted Answer

Radiation exposure to nearby patients and staff

Answer

Radiation exposure to nearby persons is the primary concern, addressed by distance, shielding, and announcements.

Question 2

What does focal spot size affect, and how is it measured during QC?

Accepted Answer

Spatial resolution and sharpness; star pattern or slit camera

Answer

Focal spot size affects geometric unsharpness and resolution, measured with star patterns or slit cameras.

Question 3

Daily CT QC shows degraded low-contrast detectability. What should be investigated?

Accepted Answer

Room temperature, detector calibration, tube output, and noise levels

Answer

Degraded LCD typically indicates increased noise from calibration drift, reduced output, or environmental factors.

Question 4

What is the purpose of dose-area product (DAP) measurement?

Accepted Answer

Estimate total radiation energy delivered, accounting for dose and field size

Answer

DAP measures air kerma multiplied by irradiated area, estimating total radiation energy.

Question 5

CT images show a ring artefact. What is the most likely cause?

Accepted Answer

Miscalibrated or defective detector element

Answer

A faulty detector element gives consistently incorrect readings, tracing a ring as the gantry rotates.

CAMRT - Canadian Association of Medical Radiation Technologists Practice Test