Grayscale contrast enhancement based on grayscale-based contrast-to-noise ratio

Subjective reading is still the majority way in current medical image diagnostics, and the visualization effect of images is one important factor which may affect the reading performance or diagnostic quality. In computed tomography (CT), CT numbers are converted into grayscale images by the display window settings. Therefore, settings of display window width and window level significantly influence the grayscale image impression, and the object detectability could be enhanced with appropriate display window settings. In this study, we propose a new idea that the window settings can be automatically adjusted based on grayscale-based contrast-to-noise ratio, which takes into account the effect of the window settings on image quality. With optimized window settings, the grayscale-based contrast is enhanced, image impression is maintained as some level of consistency, and reading performance is improved.