This image demonstrates the ability of subtracting two different energy shots, one above a K-edge, the other below a K-edge, to bring out incredible detail with dilutions of iodine unheard of in radiography. The veins in this heart phantom were filled with a 1:256 iodine:saline, and yet the veins are clearly visible in the right hand subtraction result image. The left image shows a standard absorption image showing the improvement in locating the veins by this method.