How often should QA and calibration occur for a radiographic unit?

• A. Annual calibration
• B. Weekly checks
• C. As needed after service
• D. According to manufacturer guidelines and regulatory requirements; typically daily constancy checks with periodic full QA and calibration.

Answer: (D)

The key idea is that a radiographic unit should be kept within specification through a QA program that follows manufacturer guidelines and regulatory requirements, with both daily checks and periodic comprehensive testing. Daily constancy checks ensure the machine’s output and performance are stable from one day to the next, catching drift in factors like output, timer accuracy, kV accuracy, and beam alignment before clinical use. Periodic full QA and calibration verify the system’s overall performance across all parameters and update the baseline as needed, according to the schedules set by the device maker and applicable regulations. After service, quick checks are done to confirm the unit returns to spec, but ongoing daily checks plus periodic full QA/calibration remain essential. This combined approach—daily constancy plus periodic full QA and calibration—best aligns with manufacturer guidance and regulatory requirements.