DEXA Quality Assurance & Equipment Calibration Flashcards
6 cards from real DEXA practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 DEXA Quality Assurance & Equipment Calibration flashcards as text
How often should daily phantom QA scans be performed on a DEXA system?
Answer: Every day before patient scanning
Daily phantom scans must be performed every day prior to patient scanning to verify system accuracy and detect drift.
What is the primary purpose of a spine phantom (e.g., Hologic or GE Lunar phantom) in DEXA QA?
Answer: To calibrate the system and detect BMD measurement drift
Spine phantoms are used to calibrate the DEXA system and monitor for measurement drift over time.
A DEXA system's daily QC phantom result falls outside ±1.5% of the long-term average. What is the correct action?
Answer: Do not scan patients; investigate and contact the manufacturer
A phantom result outside the ±1.5% control limit requires halting patient scans and investigating the cause before proceeding.
Which statistical tool is typically used to track DEXA daily phantom data over time and identify trends?
Answer: Shewhart control chart (QC chart)
Shewhart control charts plot daily phantom BMD values and visually flag drift or sudden shifts in machine performance.
When should a DEXA system's cross-calibration be performed?
Answer: After major repairs, software upgrades, or detector replacement
Cross-calibration is required after any significant hardware or software change to ensure continuity of serial patient measurements.
What does a sudden step-change (shift) in the daily QC control chart most likely indicate?
Answer: A hardware or software change affecting system performance
A step-change in QC data typically signals a discrete system event such as a detector swap, software update, or phantom replacement.
How this page was made: written with AI tools and published by Nathan Beja, founder of Practice Test Geeks, who is responsible for its content. Exam facts are checked against the official sources listed below. Not reviewed by a subject-matter expert. Editorial policy
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