A method includes determining at least one characteristic about a stenosis in a vessel of a patient from image data of the stenosis, mapping the characteristic to a predefined stenosis characteristic to fractional flow reserve value look up table, identifying the fractional flow reserve value in the look up table corresponding to the characteristic, and visually presenting the image data and the identified fractional flow reserve value. A system includes memory storing a pre-defined stenosis characteristic to fractional flow reserve value look up table, a metric determiner (118) that maps at least one characteristic about a stenosis in a vessel of a patient, which is determined from image data of the stenosis, to a characteristic in the look up table and identifies a fractional flow reserve value corresponding to the characteristic, and a display (116) that visually presents the image data and the identified fractional flow reserve value.