1. A method of medical image registration, the method comprising: obtaining a first medical image; obtaining a second medical image generated in real time; extracting first landmark points of the first medical image and the second medical image from a first adjacent anatomical object recognizable in the second medical image among anatomical objects near an organ of interest; extracting second landmark points of the first medical image and the second medical image from a second adjacent anatomical object recognizable in the second medical image among anatomical objects near an organ of interest; and registering the first medical image and the second medical image by matching a coordinate system of the first medical image and a coordinate system of the second medical image based on a geometrical correlation among the adjacent anatomical objects indicated by the first and the second landmark points of the first medical image and a geometrical correlation among the adjacent anatomical objects indicated by the first and the second landmark points of the second medical image, wherein the matching of the coordinate system further comprises: selecting boundary regions indicating silhouettes of the adjacent anatomical objects in the first medical image and the second medical image based on a change of a brightness of voxels of the first medical image and the second medical image; and correcting a coordinate system of the first medical image or the second medical image based on a similarity between directions in which the brightness of the voxels increases and decreases in the boundary regions selected in the first medical image and the second medical image.