The invention provides a two-dimensional and three-dimensional medical
image registration method, which can quickly carry out registration on an intra-operative two-dimensional X-
ray image and a preoperative three-dimensional CT (
Computed Tomography) image. The two-dimensional and three-dimensional medical
image registration method comprises the following steps: carrying out filtering preprocessing on the three-dimensional CT image, projecting the three-dimensional CT image in two mutually-
orthogonal plane systems to obtain two corresponding digitally reconstructed radiograph (DRR) sets according to a
maximum intensity projection (MIP)
algorithm; obtaining two two-dimensional X-
ray images on another two orthogonal planes, and carrying out the filtering preprocessing on the two-dimensional X-
ray image; carrying out traversal on the two DRR sets, and carrying out registration on the two DRR sets and another two orthogonal two-dimensional X-ray images so as to determine a corresponding most similar DRR as well as the in-plane position coordinate, the in-plane rotation angle and an out-of-plane rotation angle of the DRR; converting the coordinate and the angles to be under a three-dimensional CT image coordinate
system to obtain six registration parameters. According to the method, the X-ray image and the CT image which is generated in advance can be subjected to accurate and quick real-time registration.