The density of all patient-equivalent phantom films should be within what percent of the average density?

• A. +/- 5%
• B. +/- 10%
• C. +/- 15%
• D. +/- 20%

Answer: (B)

The main idea here is quality assurance for film density in phantom imaging. When you use patient-equivalent phantom films to check consistency, the goal is stable, repeatable results from session to session. Keeping each film’s density within about 10% of the average density ensures that normal day-to-day variations in processing conditions, film speed, processing temperature, scanner calibration, and exposure setup don’t mask real changes in the imaging system. If the variation stays within roughly 10%, you can trust that the system is behaving consistently. If it wanders beyond that, it signals a potential issue in processing, exposure, or setup that needs investigation.