The coronary tree will be divided into the following segments which correlate to conventional angiogram segments Proximal RCA, 2-mid RCA, 3-distal RCA and PL, 4-PDA, 5-LM, 6-proximal LAD, 7-mid LAD, 8-distal LAD, 9-largest diagonal, 10, proximal CX, 11-Distal CX, 12-largest marginal.