An image processing apparatus and a medical image diagnosis apparatus comprise a creation unit, a designation unit, a measurement unit, and a display control unit. The creation unit is configured to create a virtual endoscopic image observed using a preset viewpoint position and a preset line-of-sight direction based on 3-dimensional image data. The designation unit is configured to analyze the 3-dimensional image data to designate a plaque portion and/or a calcification portion. The measurement unit is configured to measure information on spatial distribution of the plaque portion and/or the calcification portion designated by the designation unit. The display control unit is configured to perform control to display the virtual endoscopic image created by the creation unit and the information on spatial distribution measured by the measurement unit.