Quality comparison of direct digital panoramic radiography and computed radiography panoramic

Background and aim: digital panoramic x-ray images can be captured using photostimulable phosphors or solidstatedetectors (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 digitalradiography (ddr). both of these technologies have their own advantages and disadvantages. one of the mostimportant fields in comparison of these systems is their resultant image quality. the purpose of this study was tocompare the subjective image quality of ddr and cr digital panoramic system, and to assess the overall density andcontrast of their images.methods: 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 andmaxillofacial radiologists independently. in addition, observers assessed overall density and contrast of each image on a3-point scale.results: using chi-square test, no statistically significant differences were found (p > 0.05) in subjective image qualityof anatomic structures between the two radiographic systems. but ddr system outperformed cr system in overalldensity and contrast of the image. p values for both overall density and contrast of the images was less than 0.001.conclusion: the subjective image quality of cr and ddr panoramic systems in specified anatomic regions werefound statistically comparable in this study. in overall density and contrast of the radiographs, ddr system provedbetter than cr system.