Methods, apparatuses, media and signals for evaluating a vessel. One method includes receiving at least one measurement of a physical dimension of the vessel, and producing an indication of abnormality in the vessel, in response to the at least one received measurement and at least one population-based parameter for the vessel. Producing may include producing an indication of stenosis of the vessel, in response to the physical dimension measurement and a population-based reference dimension for the vessel. This may include producing a population-based percent stenosis value in response to a ratio of the physical dimension measurement to the population-based reference dimension. Producing may further include identifying a shape characteristic of the vessel, which may include producing a tapering comparison value in response to the tapering of the vessel and a population-based average tapering value. The vessel may include a coronary artery segment, for example.