Entrance surface air kerma to patients during digital radiographic examinations in Tanzania.

The aim of this study was to determine the entrance surface air kerma (ESAK) in adult patients during digital radiography and to evaluate the optimisation potential in five common X-ray examinations in Tanzania. Based on a sample of 240-610 patients, ESAK was estimated using X-ray tube output measurements, patient information and backscatter factors. The results show that the mean ESAK values were higher or comparable to data from the literature. The diagnostic reference values of ESAK for digital radiography were 0.31 mGy (chest PA), 4 mGy (lumbar spine AP), 5.4 mGy (lumbar spine LAT), 3.8 mGy (abdomen AP) and 2.4 mGy (pelvis AP). For computed radiography, the mean ESAK ranges were 0.44-0.57 mGy (thoracic AP), 3.59-3.72 mGy (lumbar spine AP), 6.16-6.35 mGy (lumbar spine LAT), 3.89-3.44 mGy (abdominal AP) and 2.92-3.47 mGy (pelvic AP). In conclusion, high ESAK variations show the potential for optimising protection in digital radiology.

Radiation exposure during CT procedures in Tanzania.

The aim of this study was to evaluate optimisation status during common computed tomography (CT) procedures by determining values of volume computed tomography dose index (CTDIvol) and dose-length product (DLP) per examination. Patient and exposure data were collected from the CT console during various CT procedures. The results show that variations in CTDIvol and DLP values were mainly because of differences in the techniques used. The 75th percentile values were set as the third quartile of the median CTDIvol or DLP values for all hospitals. These values of 40.9, 9.0, 9.4 and 16.2 mGy for CTDIvol were determined for head, high-resolution chest, abdomen-pelvis and lumbar spine, respectively. The corresponding DLP values for the same sequence of CT procedures were 900, 360, 487 and 721 mGy.cm, respectively. The updated results provide a basis for optimising the procedures of CT in this country.