Image Quality and Dose Dependence on X-ray Exposure Factors

Abstract

In this study, the investigation of image quality and dose dependence on diagnostic X-ray exposure factors was conducted using kVp multi-meter, Edmond’s formula and densitometer. A total of 100 patients were exposed to diagnostic X-ray during their routine chest X-ray examinations. The exposure factors of kilovolt (kVp) and tube current time (mAs) that produced optimal doses and optical density associated with X-ray films obtained from three Hospitals labelled HSP1, HSP2 and HSP3 showed the mean exposure factors of 55 kVp and 5.4 mAs with 0.72 optical density; 67 kVp and 34 mAs with 0.94 optical density; 62 kVp and 16 mAs with 0.75 optical density respectively. The fourth hospital labelled HSP4 showed the mean exposure factors of 73 kVp and 3.5 mAs with 0.88 optical density.The kVp and mAs investigated show optical density in the range of 0.72 to 0.94 OD that produced good image quality. The measured and calculated patients dose in the Hospitals was compared with reference dose levels. This study provides guidance on where efforts on dose reduction will need to be directed to fulfil
the requirements of optimization process