Grayscale contrast enhancement based on greyscale-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 greyscale images by the display window settings. Therefore, settings of display window width and window level significantly influence the image visibility, 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 greyscale-based contrast-to-noise ratio, which takes into account the effect of the window settings on image quality. With optimized window settings, the greyscale-based image contrast is enhanced and reading performance is improved.