Medical image observation assisting system 1 including CT-image-data retrieving portion 10, CT-image-data storing portion 11, information extracting portion 12, anatomical information DB13, point of view/line of view setting portion 14, luminal organ image generating portion 15, anatomical nomenclature information generating portion 16, branch specifying portion 17, image synthesizing and displaying portion 18 and user I/F control portion 19. The point of view/line of view setting portion 14 sets a point of view and line of view for observing an external profile of a luminal organ, on the basis of structure information of the luminal organ extracted by the information extracting portion 12, while a point of interest is kept substantially on a centerline of the organ.
