1. A medical image processing apparatus comprising: an imaging unit configured to image an affected area in two directions using X-rays; a fluoroscopic image generating unit configured to generate two X-ray fluoroscopic images corresponding to the two directions, on a basis of imaging signals outputted from the imaging unit; a rendering image generating unit configured to project the affected area contained in three-dimensional image data acquired in advance, in two directions according to a same X-ray geometry as that used for imaging the X-ray fluoroscopic images, to thereby generate two affected area rendering images; and an image combining unit configured to combine the X-ray fluoroscopic images with the affected area rendering images for each corresponding direction, to thereby generate combined parallax images in two parallax directions corresponding to the two directions, and to output the two generated combined parallax images to a 3D display apparatus.