1. A method of image analysis to produce a cardiovascular index, the method comprising: receiving vascular image data including: relative positions in one or more two-dimensional angiographic images of a plurality of vascular segments linked by branch points, and at least one lesion for which a respective lesion metric includes one or more of a cross-sectional area of a stenotic segment, a plaque strength, a plaque stress, and a size and/or position relative to the vascular segments; determining automatically a plurality of lesion-related vascular metrics for each of a plurality of said vascular segments, based on at least one angiographic image of said received image data; determining at least one subscore based on a function of said plurality of lesion-related vascular metrics, and on said position of the lesion within the vascular segments and relative to the branch points; determining a myocardial perfusion risk index based on said at least one subscore; and outputting said myocardial perfusion risk index to an electronic storage medium or display.