How often should image quality be checked using a phantom?

• A. Annually and for acquisition device
• B. Monthly
• C. Weekly
• D. Daily

Answer: (A)

Testing image quality with a phantom is a comprehensive QA measure of the imaging chain, checking resolution, contrast, noise, and artifacts in a controlled way. It is typically performed on an annual basis to establish a baseline and detect gradual drift over time. It should also be repeated whenever the acquisition device is serviced or changed, to confirm that performance remains within specification after modifications. Daily, weekly, or monthly checks serve different QA tasks—quick constancy checks or device readiness—while a full phantom IQ test is too time-consuming for frequent use, so the annual schedule coupled with re-testing after changes is the standard approach.