The invention relates to a two-dimensional and three-dimensional medical
image registration method and a
system, wherein the method comprises the steps of: generating a three-dimensional image of a three-dimensional imaged body, and generating a DRR (data receiving register) image
library in an offline manner along the direction of a rotating angle outside the plane; acquiring an X-
ray image of the three-dimensional imaged body; taking the X-
ray image as a registered image, taking the DRR image in the DRR image
library generated in an offline manner as a
reference image, and respectively carrying out
estimation on values such as a transition parameter in the plane, and / or a rotating angle parameter in the plane, and / or a rotating angle parameter outside the plane; taking a newest parameter
estimation result as a reference position to carry out adjustment on a three-dimensional image, and generating the DRR image
library along the rotating angle directions outside the two planes; taking the X-
ray image as the registered image, taking the DRR image in the newest DRR image library generated in an online manner along the rotating angle directions outside the two planes as the
reference image, and respectively carrying out
estimation on values such as the transition parameter in the plane, and / or the rotating angle parameter in the plane, and / or the rotating angle parameter outsidethe plane.