Fluoroscopy Dose Reduction for Patients and Staff

How much radiation in fluoroscopy: what drives dose

The dose in fluoroscopy is driven mainly by beam-on time, the dose rate in the chosen mode, the size of the irradiated field and the patient's thickness. A short examination in pulsed mode with tight collimation may deliver far less than a long examination in continuous mode with a large field, even on the same machine. Staff dose follows patient dose, because scatter comes mainly from the patient.

For that reason the discussion should be about controlling these factors rather than quoting a single number. Dose values for your own examinations should be measured and compared against local reference data.

Patient size deserves special attention. Larger patients need a higher dose rate to keep image quality, and children are more sensitive to radiation, so protocols for children should be set separately and reviewed regularly.

Pulsed fluoroscopy, frame rate and last-image hold

Pulsed fluoroscopy delivers short X-ray pulses instead of a continuous beam. Lower pulse rates reduce dose, so the operator should use the lowest frame rate that still shows the motion needed for the examination. Systems such as Villa's Apollo DRF support both continuous and pulsed fluoroscopy on a 43 x 43 cm dynamic detector.

Last-image hold keeps the final frame on the monitor after the beam is switched off, allowing the operator to review, plan and discuss without further exposure. Combined with a habit of short intermittent beam bursts, it is one of the most effective dose-saving functions. Ask whether the system also offers storage of fluoroscopic loops and image processing that allows lower dose per frame.

• Use pulsed mode and the lowest acceptable pulse rate
• Use last-image hold instead of re-exposing to review
• Keep beam time as short as possible
• Avoid magnification modes unless needed, since they usually raise dose rate

Collimation, grid and positioning aids

Collimation is the simplest dose-saving step: it reduces the irradiated volume, scatter and dose-area product, and improves contrast. The Villa Chronos offers virtual collimation, which lets the operator adjust the collimator on the last image without exposure, and a touchscreen collimator with joysticks. The Apollo DRF includes an integrated camera for patient centring without X-ray emission.

The anti-scatter grid also matters. Automatic grid selection and removal, as in Apollo DRF for paediatric examinations and in the dual automatic grid of Chronos, helps avoid the extra dose of an unnecessary grid. Read more in our explainer on anti-scatter grids and bucky devices.

Dose area product, DAP monitoring and DRLs

Dose area product (DAP) is the air kerma multiplied by the beam area. It is displayed on modern R/F systems and is the most common indicator for tracking patient exposure in fluoroscopy. The Chronos is described with real-time DAP monitoring, and dose reporting through structured reports (RDSR) allows dose data to travel with the images to PACS or a dose management tool.

Diagnostic reference levels (DRLs) are investigation levels set for typical examinations. By comparing your median dose values with national or regional DRLs, where they exist, you can see whether protocols need optimisation. Confirm current DRL and dose-reporting expectations with FANR and your health authority. Our guide on X-ray quality control tests explains calibration of DAP meters.

Staff protection and buying advice

Staff should wear lead aprons and thyroid shields, use ceiling-suspended or table-mounted shields where available and keep the maximum distance from the beam during exposure; see radiation protection in fluoroscopy. Aprons must be inspected regularly, as covered in lead apron testing and care.

When buying a system, ask about pulse-rate options, last-image hold, virtual collimation, dose display, RDSR support and automatic exposure rate control. Compare the Chronos and Apollo DRF on these points, and ask Beckfinity for a demonstration with your own protocols in mind.