Assessment of Image Quality and Radiation Dose to Adult Patients undergoing Computed Radiography Examinations

Image quality and its related entrance surface dose to adult patients undergoing computed radiography (CR) examinations have been assessed using ImageJ software version 1.48 in two hospitals H-1 and H-2. In all 70 radiographs of adult patients were examined in the study consisting of 10 each for chest PA, cervical spine AP and LAT, lumbar spine AP and LAT and skull AP and LAT. Image quality of the radiographic images was assessed in terms of contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR). The CNR for all examinations were between 3.54 3.27 and 20.63 8.65 for the two hospitals involved in this study. A maximum difference 17.09 in CNR was found between hospital 1 (H-1) and 2 (H-2). The results obtained for SNR for both hospitals showed that 92.86% of all the images assessed were at least 1.22 higher than the Rose Model of the threshold value of 5. The images were of good quality and hence, they provided useful clinical information. The relationship between CNR and the entrance surface dose (ESD) to patients for all the examinations showed that there is a potential to reduce doses to patients while keeping images of diagnostic quality.