Phantom-Based Evaluation of Scatter Radiation at Clinically Relevant Positions in Fluoroscopy-Guided Cardiac...

Scatter radiation (SR) exposure to personnel performing fluoroscopy-guided procedures is significant and complex. With the development of next-generation shielding systems, it is essential to establish a standardized method of measuring SR for clinically relevant scenarios.

A fixed C-arm x-ray unit was used to image the chest of an anthropomorphic phantom. SR was assessed using solid-state survey meters positioned at 6 positions where personnel typically stand during procedures. SR was measured from 20 to 200 cm from the floor at each position, in 5 commonly used radiographic projections. The radiation dose from the primary beam was measured below the table and at the image detector.

Of the primary x-ray beam, 96% was absorbed or scattered by the phantom. SR dose rates were markedly higher in positions around the head of the x-ray table (average x-ray dose rate at the 3 positions near the head 4.1 ± 0.6 fold the 3 positions away from the head, P < .01). X-ray angulation markedly increased SR dose compared to the anterior-posterior projection. The right anterior oblique and caudal views generated more SR than the left anterior oblique and cranial angulations (P < .01). SR intensity to the head, body, and leg regions varied significantly between positions around the table.

Scatter radiation distribution around the x-ray table is highly dependent on the radiographic projection, with disproportionately high radiation dose levels around the head of the x-ray table and below it. This standardized method for measuring SR systematically may facilitate the assessment of enhanced radiation protection systems.