Typical Radiation Doses to Patients from Some Common X Ray Examinations in Tanzania

The results of entrance surface dose measurements on adult patients in diagnostic radiology are presented. The measurements were carried out using calibrated LiF thermoluminescence dosemeters for five simple projections of X ray examinations in major Tanzanian hospitals. The mean entrance dose per X ray examination at each hospital ranged from 0.1 to 0.9 mGy for chest AP, 3.5-13.9 mGy for abdomen AP, 1.6-13.1 mGy for pelvis AP, 3.6-12.7 mGy for lumbar spine AP and 10.0-29.6 mGy for lumbar spine LAT. Inter-hospital and intra-hospital dose variations up to a factor of 5 were observed for the same type of X ray examination, which suggests that operational conditions are not fully optimised. Under the limitations of the available resources, the techniques and skills employed are found to be the first possible sources of unoptimised doses to patients.