Current status of patient radiation doses from computed tomography examinations in Tanzania

The aim of this study was to assess the magnitude of radiation dose imparted to patients undergoing CT (computed tomography) examinations in Tanzania. The effective doses to patients undergoing five common CT examinations were obtained from eight health centres. The doses to patients were estimated using measurements of CTDI, exposure-related parameters and the CTDOSE software based on NRPB conversion factors. The mean effective doses in Tanzania for CT examinations of head, lumbar spine, chest, abdomen and pelvis were 2.2+/-0.9, 5.4+/-2.3, 12.2+/-3.4, 15.3+/-6.0 and 13.4+/-7.3 mSv, respectively. The mean effective doses and the variations in dose between hospitals in Tanzania were mostly comparable with reported values in the literature for six different countries from Europe. The observed wide variation in mean effective dose for similar CT examination among hospitals was largely influenced by different CT scanning protocols employed among hospitals. In view of the observed causes of variation in patient doses, it was concluded that further studies are needed to investigate the methods that can reduce dose to patients without affecting image quality.