Doses and image quality for chest radiographs in three Nigerian hospitals

To encourage local participation in patient dose data acquisition, a mathematical method of entrance skin doses determination, developed by Harpen, has been used to determine patient doses and radiographic/technical image quality for 169 adult patients undergoing non-grid chest radiography in three Nigerian hospitals. Calculated doses were found to be about 12.5% (range 8.9-13.3%) higher than doses obtained with thermoluminescence dosemeters (TLD). This level of discrepancy was about 4% higher than the value reported in the literature. Radiographic/technical quality was rated at 53.7% while image quality obtained against a standard image according to the European guidelines was rated with an above average score (58%). Notable variation between the hospitals was observed and the need for optimization highlighted in technical areas like collimation, film processing and in patient dose reduction using better exposure techniques. This study presents patient entrance doses and image quality in hospitals where such data was not existing and could therefore be used as a basis for future studies in dose and image quality, towards the development of local and national reference parameters. The mathematical method, though highly susceptible to errors, can be employed until dose monitoring equipment become more accessible.