Determination of radiosensitive organs in head CT for the head area

Abstract

Computed Tomographyrepresents about 10% of all diagnostic radiology procedures, but it isresponsible for almost 50% - 60% of exposure from diagnostic procedures. Inhead CT, other critical organs such as eye lenses and thyroids are in theradiation field. Therefore, dose assessment in these organs is very important.The aim of this study is to estimate the absorbed dose in critical organs ofpatients undergoing common head CT scans. In this study, the Radiosensitiveorgans in CT were determined in Razi hospital in Rasht, the capital of Gilanprovince in Iran. The standard head phantom that was built from ertalon and cheaptermolominecene dosimeter LiF; Mg: Cu; P was used for dosimetry in organs.Height and diameter of the phantom which contained holes for placing the TLDwere 32 cm and 16 cm, respectively. Readouts were obtained on a Harshaw reader.The results show that during head CT scan, the maximum absorbed dose belongs tooccipital bone skin, that is 15.2mGy, and the minimum absorbed dose belongs tothe neck, which is 0.13 mGy. For reduction of damage due to exposure in CT, itis necessary that the absorbed dose of organs be decreased.