1. A computer implemented method for generating a diagnostic comparison image, based on multiple baseline diagnostic images, the method comprising: receiving a first baseline diagnostic image into a computer readable medium; performing, with a processor, an edge detection process on the first baseline diagnostic image to create a first edge detection result; receiving a second baseline diagnostic image into the computer readable medium; performing, with a processor, an edge detection process on the second baseline diagnostic image to create a second edge detection result; determining, with a processor, an amount to shift the first edge detection result relative to the second edge detection result in order to achieve an overlay of detected edges; creating, with a processor, a comparison image from the first baseline diagnostic image and the second baseline diagnostic image using the determined relative shift amount, wherein the first baseline diagnostic image provides a first color information for the comparison image and the second baseline diagnostic image provides a second color information for the comparison image, such that pixels in the comparison image that correspond to pixels in the first baseline diagnostic image exceeding an intensity of corresponding pixels in the second baseline diagnostic image have a hue of a first color, and pixels in the comparison image that correspond to pixels in the second baseline diagnostic image exceeding an intensity of corresponding pixels in the first baseline diagnostic image have a hue of a second color, and wherein the first color and the second color are different.