Equipment Operation and Quality Control Flashcards
7 cards from real ARRT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Equipment Operation and Quality Control flashcards as text
Which daily CT quality control test verifies that CT numbers (Hounsfield Units) remain accurate and consistent?
Answer: CT number accuracy/linearity test
The CT number accuracy/linearity test confirms that scanned materials produce the expected HU values, ensuring diagnostic consistency.
What is the primary purpose of performing a daily air calibration (warm-up scan) on a CT scanner?
Answer: To calibrate detector channels and normalize dark current
The daily air calibration normalizes detector channel responses and corrects for dark current drift, maintaining uniform image quality.
Which CT quality control phantom is most commonly used to evaluate CT number accuracy, noise, uniformity, and spatial resolution?
Answer: AAPM CT performance phantom
The AAPM CT performance phantom contains inserts for testing multiple image quality parameters including HU accuracy, noise, and spatial resolution.
On a CT scanner, what does image uniformity testing evaluate?
Answer: The consistency of CT numbers across the field of view in a homogeneous phantom
Image uniformity testing measures whether a homogeneous phantom (e.g., water) produces consistent HU values across the entire reconstructed image.
Which factor is evaluated by the modulation transfer function (MTF) in CT quality control?
Answer: High-contrast spatial resolution
The MTF describes how faithfully the CT system reproduces spatial detail, directly measuring high-contrast spatial resolution performance.
What is the recommended frequency for performing a full CT equipment performance evaluation by a qualified medical physicist?
Answer: Annually
ACR and AAPM guidelines recommend a comprehensive CT performance evaluation by a qualified medical physicist at least annually.
When a CT scanner undergoes a tube replacement, which quality control step is mandatory before returning the unit to clinical service?
Answer: Full calibration and acceptance testing
After a major component replacement such as an X-ray tube, full calibration and acceptance testing must be performed to ensure the scanner meets all performance specifications.