What is the recommended frequency for testing HVL (filtration)?

• A. Monthly
• B. Annually
• C. Quarterly
• D. Biannually

Answer: (B)

HVL testing is done to verify beam quality and the effectiveness of filtration in shaping the X-ray spectrum. Filtration (inherent plus added filtration) helps remove low-energy photons, which protects patients and improves image quality. Because these components don’t usually change quickly during normal operation, HVL is typically checked once a year as part of the annual QA program. This annual timing aligns with regulatory guidelines and provides a baseline to detect gradual changes due to tube aging or filtration wear.

If HVL measurements drift outside tolerance, it signals that something in the filtration path or tube output has changed, prompting investigation of the filters, housing, or calibration, followed by re-testing to confirm the issue is resolved. Monthly or quarterly checks aren’t normally required for HVL under standard practice, though additional testing may occur after maintenance or repair.