Densitometric analysis of Radiation Absorbed Dose to Patients Undergoing Chest X-ray Examination in a Government Owned Hospital, Kano-Nigeria

Chest X-ray is one the most frequently required diagnostic procedures used in clinical practice to produce an image of organs, tissues and bones of the body with a significant impact on collective dose. However, the radiation dose received by patients from this procedure is likely to show large variations within and among radiodiagnostic centres. This could be traced to be lack of imaging protocols and a lack of local or national diagnostic reference levels. Although the radiation doses resulting from the X-ray procedures are usually measured in terms of effective dose entrance surface dose using electronic personal dosimeter (EPD), pocket dosimeter, thermoluminescent dosimeter (TLD), film badges, and optically stimulated luminescent dosimeter (OSLD). For the sake of radiation protection, densitometric analysis was used to evaluate medical exposure for chest radiographs to determine the radiation doses using a point optical densitometer; PTW-DensiX with a range of 0 to 4.0 optical density. The hospital where this study was carried out is in Kano State. A total of sixty (60) chest radiographic films were collected from the hospital and the optical density of each radiographic film was measured five times at different spots. The mean optical density was obtained and converted by a mathematical relation to absorbed radiation dose in cGy. The results obtained in this study show that the mean absorbed X-ray dose was 0.78 ± 0.13 cGy and is low compared to the previous study held for hospitals in Osun State. Also, when compared with the excess dose of 0.10 Gy recommended by the International Commission on Radiological Protection, it was evident that radiological practice especially as it relates to chest radiographs at the hospital in Kano is within the recommended practice. Keywords: Absorbed dose, Densitometer, Optical Density, Radiation, X-ray