A data management system automatically manages image buffers to produce images for angiography using a first memory portion, a second memory portion and an image data processor. The first memory portion stores first image frame data representing minimum luminance values of individual pixels of a sequence of medical images. The second memory portion stores second image frame data comprising a difference between the minimum luminance values and corresponding maximum luminance values. The image data processor processes data representing an acquired X-ray image frame of a catheterized vessel using a stored frame of maximum or minimum pixel luminance values and the second image frame data to provide an image with enhanced visualization of a catheter in a vessel.