連載　医用画像の実践的画質評価（3）―ディジタルX線画像の画質を視る―

抄録

In the environment of picture archiving and communication system (PACS), the subjective evaluation of medical image quality is performed using an image display monitor. Commonly, PACS and its image viewer can handle digital imaging and communications in medicine (DICOM) format image files that are displayed as 8-bit grayscale images in the monitor. However, the original grayscale of DICOM image is between 10-bit to 16-bit depth. Therefore, in order for DICOM images to be displayed in the monitor by PACS image viewer, they need to be converted into 8-bit depth grayscale. This conversion indicates that the original characteristics of DICOM images are altered when they are displayed in the monitor by PACS image viewer. Moreover, image data interpolation to match the image matrix for the resolution of the monitor also alters the characteristics of images. For these reasons, it is a must to recognize the influential factors of image display settings for the subjective evaluation of medical image quality.