Quantitative coronary angiography has become an invaluable tool for the interventional cardiologist, providing objective and reproducible measurements of coronary artery dimensions, which can be used to study progression or regression of coronary atherosclerosis, as well as the immediate and long term effects of percutaneous interventions. Until recently, this powerful imaging technology was confined to a small number of so-called high level institutions. Fortunately, with the development of digital cardiac imaging equipment and adaptation of cine-angiographically based computer software for...