Under what condition should the repeat rate be analyzed?

• A. If rate changes by more than 2%
• B. If rate changes by more than 10%
• C. Only during QC events
• D. If rate changes by more than 0.5%

Answer: (A)

Monitoring repeat rate is about catching small shifts in imaging performance before they become bigger problems. When the repeat rate changes by more than a modest amount, like 2%, it signals a possible drift in technique, exposure, positioning, compression, or equipment quality that deserves investigation. A threshold of 2% is a practical balance: it’s sensitive enough to catch meaningful trends without flagging normal random variation, and it prompts review of workflow and setup to maintain consistent image quality. Larger thresholds (such as 10%) could let issues go unnoticed, and relying only on QC events would miss ongoing changes between checks. A threshold as small as 0.5% would create too many alarms with little actionable value. If a change is detected, investigate the imaging process and equipment, review techniques and patient factors, and verify calibration and maintenance to restore stable performance.