Defining digital radiography in terms of patient comfort and ease of operation

Abstract

possible in a dental school setting. Being a new system, it is important to know how the image quality is affected by delayed scanning of these plates. Objectives. The objective of this study was to determine the effect of delayed scanning of OpTime plates exposed at different exposure times. Methods and Materials. A 20 step aluminum stepwedge was imaged with eighteen OpTime plates exposed using exposure settings corresponding to anterior (0.10sec), bitewing (0.16sec) and molar (0.20sec) areas (Table I). Plates were scanned immediately, 1 hour, 4 hours, 8 hours, 16 hours and 24 hours after being exposed. A Gendex 770 x-ray unit operating at 65 kVp, 7 mA and a source to receptor distance of 15 inches was used. The MiPACS (Medicor Imaging) imaging software was used to acquire and evaluate the images. The most clearly detectable number of steps were counted by two board certified oral and maxillofacial radiologists. Mean gray values (MGV) were obtained using Adobe Photoshop 7.0. Results. MGVs of the immediately scanned plates provided the gold standard values. In general, MGVs increased with the scanning delay. Discussion. We believe that scanning delay contributed to the fading of the latent image due to loss of signal. These results are in agreement with the previous studies. The number of steps discerned decreased with increasing delay at the lighter end of the stepwedge. It would be worthwhile to understand how these factors affect clinically relevant diagnostic tasks.