What is the difference between window level and window width?
Window level is the gray scale value that is selected to be displayed as the midlevel intensity on an image and determines the displayed image brightness. Window width is the range of gray scale values that is selected to be displayed in image voxels as shades of gray around the selected window level and determines the displayed image contrast. For gray scale values above or below this selected range, image voxels are displayed white and black, respectively. A narrow window width provides high contrast. Preset window level and width combinations are commonly used to optimally display certain tissue types on digital images.