Eye Lens Dose Reduction in Head CT Using Bismuth Shielding : Application in CT Facility in Cameroon

The purpose of this study is to compare the radiation dose received by the patients during head Computed tomography (CT) scan examination in a developing country like Cameroon (General Hospital of Yaounde (GHY)) with a developed country like Belgium (UZ Ghent). We also evaluate the ability of thin overlying bismuth shielding to reduce the x-ray dose to the eye lens during CT. With in-plane shielding, the x-ray beam is partially blocked to reduce the dose to the underlying tissue while allowing a sufficient amount of x-rays to pass in order to generate a diagnostic quality CT image. Bismuth garments are mainly used for breast, thyroid and eye-lens shielding in CT to protect the organs at risk from direct exposure. This work has shown that patients in Yaounde receive a higher lens dose than those of Ghent, related to the use of CT equipped with innovation dose reduction techniques. With the bismuth shielding we obtained a dose reduction of about 38% at the General Hospital of Yaounde.