A system and method for generating a border of a region of interest of an image, such as a medical image, are disclosed. Imaging data is acquired for generation of an image. A region of interest of the image is determined. A display value is allocated to a plurality of pixels, respectively, based on color or tissue information from the imaging data. If at least one pixel corresponds to a border of the region of interest, a border value is allocated to the at least one pixel substantially at the same time as when the display value is allocated. The image having the border of the region of interest is displayed.