Would lead shielding the eye lenses during a head CT be beneficial?

Abstract

The lens of the eye is one of the radiosensitive organs. Patients receiving computed tomography (CT) scanning of the head, as well as patients undergoing repeated CT scanning of the head, are at risk for this consequence. The goal of this study was to see if a lead equivalent might reduce radiation reaching the eye’s lens during regular cranial CT. The goal was accomplished by determining the ideal shielding thickness for patient applications by first evaluating the image quality using phantom measurements taken with and without lead shielding. LiF-thermoluminescent dosimeters were used to quantify the entrance surface doses (ESDs) to the eye lenses of the ATOM phantom without, with one, two, and three layers of lead shielding. The use of customized lead shields up to 0.1 mm thick might be used, according to ACR CT Phantom studies, without having a noticeable impact on the image quality for the central and posterior areas. In these experiments, 0.1 mm thick lead shielding reduces ESDs to the eye’s lens by 31%. Eye shields significantly reduced image quality in the anterior region, but just slightly in the centre and posterior regions. Given the foregoing, using modified lead shields could drastically lower dose to the lens without severely affecting image quality.