In an embodiment, cross sectional image storage stores a cross sectional image group including multiple cross sectional images each of which is associated with time. Phase image storage stores a phase image group including multiple phase images each of which is associated with time. Blood flow information storage stores a blood flow information group including multiple blood flow information each of which is related to blood flow in a blood vessel of the living body and is associated with time. Display synchronously displays a cross sectional image included in the cross sectional image group and a phase image included in the phase image group using time associated with the cross sectional image and the phase image, and displays a blood flow image that expresses multiple blood flow information. The display performs the same change as the change to the cross sectional image, the phase image and the blood flow image.
