There is provided an imaging apparatus for diagnosis in which a simpler configuration enables an anatomical technique and a physiological technique to be combinedly used. The imaging apparatus for diagnosis disclosed herein includes first calculation means for calculating a parameter indicating each deformation degree of measurement slit portions 311 to 314 and 321 to 324, by using a tomographic image including the measurement slit portions 311 to 314 and 321 to 324 which are disposed at different positions in an axial direction of a probe unit and whose cross-sectional shape is deformed in response to a pressure applied to the probe unit, and second calculation means for calculating a value corresponding to a myocardial fractional flow reserve, based on the calculated parameter.
