ARRT - American Registry of Radiologic Technologists Equipment Operation and QA Questions and Answers

Question 1

A radiograph of the pelvis exhibits a uniform loss of density across the entire image.
The technologist used a focused grid and suspects grid cutoff.
Which of the following errors is the MOST likely cause?

Accepted Answer

Off-level grid error

Answer

Upside-down focused grid

Answer

Off-center grid error

Answer

Off-focus grid error

Question 2

A quality control test is performed on a single-phase, full-wave rectified x-ray unit. A spinning top test is used to evaluate timer accuracy with an exposure time of 0.1 seconds. How many dots should appear on the finished radiograph?

Accepted Answer

12

Answer

6

Answer

2

Answer

24

Question 3

Which of the following describes the primary function of a falling load generator?

Accepted Answer

To use the maximum heat capacity of the tube to achieve the shortest possible exposure time.

Answer

To maintain a constant voltage throughout the exposure.

Answer

To allow for longer exposure times with very low mA settings.

Answer

To automatically select the optimal kVp based on part thickness.

Question 4

A digital radiograph of a knee appears grainy and mottled. The technologist confirms that positioning and collimation were accurate. Which of the following is the MOST likely cause of this appearance and how should it be corrected?

Accepted Answer

Quantum mottle; increase the mAs.

Answer

Grid cutoff; ensure proper beam-grid alignment.

Answer

Saturation; decrease the kVp.

Answer

Processor artifact; clean the processor rollers.

Question 5

Which of the following is a key component of the NEMA XR-29 (MITA Smart Dose) standard for CT scanners?

Accepted Answer

Automatic Exposure Control (AEC).

Answer

Iterative reconstruction algorithms.

Answer

A minimum of a 128-slice detector.

Answer

Integrated Picture Archiving and Communication System (PACS).

Question 6

During routine quality control for an Automatic Exposure Control (AEC) system, the technologist makes several exposures of a phantom at different mA stations while keeping all other factors constant. The goal of this test is to evaluate the AEC's:

Accepted Answer

Exposure reproducibility.

Answer

Kilovoltage response.

Answer

Backup timer function.

Answer

Density control accuracy.