Paediatric pelvic imaging: optimisation of dose and technique using digital grid-controlled pulsed fluoroscopy

An audit of paediatric pelvic radiographs identified deficiencies in gonad shield placement and radiographic technique.

A technique using grid-controlled fluoroscopy (GCF), with hard copy images in frame grab and digital spot image (DSI) format was evaluated to optimise gonad shield placement and reduce the dose given to children with Perthes disease and Developmental Hip Dysplasia (DDH) attending for pelvic radiography.

Phantom and patient dose surveys of conventional and fluoroscopic techniques were carried out. Image quality and radiation dose were compared for the frame grab and DSI techniques. Retrospective evaluation was undertaken to compare their clinical acceptability.

Both fluoroscopic techniques gave considerably less radiation than conventional non-grid radiography (67-83%, P < 0.05). The frame grab technique gave less radiation than DSI (P < 0.05). There was no significant difference in the clinical acceptability scores of the DSI and frame grab images.

Fluoroscopy acquired images are now used since the fluoroscopic techniques give much less dose than conventional radiography and provide images of sufficient quality for clinical assessment. Indeed, as there was no significant difference in clinical usefulness between the frame grab and DSI techniques, it is planned to use frame grab alone, thus gaining additional dose saving.