Quality comparison of direct digital panoramic radiography and computed radiography panoramic

Digital panoramic X-ray images can be captured using photostimulable phosphors or solid-state detectors (i.e. charge-coupled devices and Flat-Panels). The first category is defined as computed radiography (CR) or semi-direct radiography. The second technology that uses solid-state detectors is known as direct digital radiography (DDR). Both of these technologies have their own advantages and disadvantages. One of the most important fields in comparison of these systems is their resultant image quality. The purpose of this study was to compare the subjective image quality of DDR and CR digital panoramic system, and to assess the overall density and contrast of their images. 200 patients were randomly allocated to two digital systems: Promax [central control digital (CCD)] and XC [photostimulable phosphor plates (PSP)]. Image quality was evaluated in six regions on a 3-point scale by three oral and maxillofacial radiologists independently. In addition, observers assessed overall density and contrast of each image on a 3-point scale. Using chi-square test, no statistically significant differences were found (P >0.05) in subjective image quality of anatomic structures between the two radiographic systems. But DDR system outperformed CR system in overall density and contrast of the image. P values for both overall density and contrast of the images was less than 0.001. The subjective image quality of CR and DDR panoramic systems in specified anatomic regions were found statistically comparable in this study. In overall density and contrast of the radiographs, DDR system proved better than CR system.KEYWORDS: