Abstract
Sophisticated devices designed for CRT diagnosis are expensive and many use personal computers for experiments and small-scale clinical applications. However, reports of their physical performance, capabilities and limits are lacking. To evaluate the physical properties of CRT for personal computers, phantom chest radiographs, MTF chart, alminium step, gradiation pattern for laser imagers, SMPTE chart and abdominal CT images were digitized through a film scanner. The digitized and the original images were compared by two radiologists and a computer programmer. The digitized images consistently showed more noise and were always degraded. Various scanning resolutions resulted in different image quality, data size and display speed and therefore, was critical to determining the operability of the system. From the results, images with high contrast and sharp margins were thought to be suitable for CRT diagnosis. ROC analysis of pulmonary nodule detection on the CRT monitor was carried out since it is important clinically, and also it seemed to fulfil the image quality requirements derived from the above experiments. A total of 420 digitized and original chest X-ray images were compared by 6 board-certified radiologists. ROC analysis revealed that there were no differences between the detection rate of pulmonary nodules among the original films and the digitized images (p<0.05), although there were tendencies to miss the smaller lesions. Our studies show that CRT monitors for personal computers could be used for image diagnosis in limited purposes such as pulmonary nodule detection. With magnification, image postprocessing, developments in hardware and software, diagnosis of lesions that require precise image quality may become possible on less costly personal computer systems in the near future.
