Which fluoroscopy technique helps minimize patient dose by freezing the last image rather than continuous exposure?

• A. Pulsed fluoroscopy
• B. Last-image hold
• C. High frame rate
• D. Increased magnification

Answer: (A)

The important idea here is reducing radiation exposure during fluoroscopy by controlling how the X‑ray beam is used. Pulsed fluoroscopy saves patient dose by turning the beam on only in short bursts rather than continuously. By lowering the effective frame rate, the total time the patient is irradiated decreases, while still giving enough real-time images to guide the procedure.

The last-image hold, while useful for viewing the most recent frame, doesn’t reduce the actual exposure that was delivered to acquire that image, and it doesn’t prevent new exposures when fluoroscopy continues. So the technique that directly decreases patient dose is pulsed fluoroscopy. Higher frame rates increase dose, and magnification raises skin dose, whereas last-image hold is not a primary dose-saving mechanism.