Usefulness of a lead-acrylic shield for reducing lens dose of assistant in x-ray CT examination.

In computed tomography (CT) examinations, the usefulness of protective glasses for reducing lens exposure to assistants has been reported. The present study aimed to compare the dose reduction effect for assistants with lead-acrylic shields and protective glasses (0.07 mm Pb, 0.5 mm Pb) during CT examination. The air dose distribution in a CT examination room with and without a lead-acrylic shield was compared. It was found that the amount of scattered radiation was significantly reduced by installing a lead-acrylic shield at the CT gantry aperture. Moreover, the reduction rate of air kerma at the assistant's lens was higher using the lead acrylic shield than with the protective glasses-95.7% during head holding and 76.1% during assisted ventilation.