METHOD FOR RECONSTRUCTING A LOCAL HIGH RESOLUTION X-RAY CT IMAGE AND APPARATUS FOR RECONSTRUCTING A LOCAL HIGH RESOLUTION X-RAY CT IMAGE

摘要

The present invention relates to a method and apparatus for reconstructing an X- ray CT (computerized tomography) image, and more particularly, to a method and apparatus for reconstructing a local high resolution X-ray CT image. Further, the apparatus of the present invention can control the resolution of an X-ray CT image to be reconstructed by changing the distance between a target object and an X-ray generator. A method for reconstructing a CT image including a high resolution X-ray CT image for a local region of interest according to an aspect of the present invention comprises the steps of acquiring projection data by means of irradiation of X-rays on a target object at a position close to an X-ray generator such that a portion of the target object including a local region of interest exists within a range of irradiation angles of X-rays; calculating virtual projection data on the assumption that the X-rays are irradiated on the entire target object at the close position, based on projection data acquired through irradiation of the X- rays on the entire target object at a position where the entire target object exists within the range of irradiation angles of X-rays; combining the virtual projection data on the entire target object except data on the local region of interest with the projection data acquired at the position close to the X-ray generator; and reconstructing the combined projection data.