An imaging apparatus and method determines distribution and a type of tissue attribute in a vascular cross section based on reflected wave data of ultrasound detected by an imaging core and interference light data including a reflected wave of light detected by the imaging core. A portion of match/mismatch is determined by comparing respectively classified vascular tissue attributes. Then, the distribution of the body tissue attributes is displayed by superimposing the distribution on any one of an ultrasound cross-sectional image, an optical interference cross-sectional image, and a composite image between the ultrasound cross-sectional image and the optical interference cross-sectional image, in a display form in which the match/mismatch can be identified.