Which fluoroscopy parameter most directly affects the cumulative patient radiation dose?

Which fluoroscopy parameter most directly affects the cumulative patient radiation dose?

• A. mA
• B. kVp
• C. Frame rate
• D. Source-to-image distance

Answer: (C)

Cumulative dose is the total energy delivered over the procedure, i.e., dose rate times exposure time. The frame rate sets how many image frames (pulses) are produced each second. If you keep exposure time the same, a higher frame rate means more x-ray pulses in that time, so more radiation is delivered and the cumulative dose increases. While tube current and voltage affect the dose per frame and distance alters dose via the inverse-square law, the frame rate directly scales how much radiation accumulates over the duration of fluoroscopy. Lowering the frame rate reduces the number of pulses per second and markedly lowers the cumulative dose with typically acceptable image quality in many settings.

Cumulative dose is the total energy delivered over the procedure, i.e., dose rate times exposure time. The frame rate sets how many image frames (pulses) are produced each second. If you keep exposure time the same, a higher frame rate means more x-ray pulses in that time, so more radiation is delivered and the cumulative dose increases. While tube current and voltage affect the dose per frame and distance alters dose via the inverse-square law, the frame rate directly scales how much radiation accumulates over the duration of fluoroscopy. Lowering the frame rate reduces the number of pulses per second and markedly lowers the cumulative dose with typically acceptable image quality in many settings.