The Cardio Z App calculates z-scores for the coronary arteries at most useful positions. These include measurements of the Left Main Coronary artery, the Proximal Circumflex, Proximal Left Anterior Descending and the Right Coronary Artery at multiple positions. The range of reference points available depends upon the reference data selected, and one offers the facility to use Aortic Valve size, rather than BSA, as the body size parameter.