Patent ID: 7630472

Claim:
An X-ray computed tomography apparatus, comprising: an X-ray tube which generates X-rays; an X-ray detector which detects X-rays transmitted through a subject to be examined; a mechanism which continuously rotates the X-ray tube and the X-ray detector; a storage unit which stores projection data detected by the X-ray detector; a read unit configured to read out, from the projection data stored in the storage unit, a pair of partial projection data sets spaced apart from each other by 360°, each partial projection data set including a plurality of views; an index generating unit which generates a plurality of indices indicating movement of a heart on the basis of a difference between the read out partial projection data sets; a cardiac phase determination unit which determines a cardiac phase on the basis of the indices; and a reconstruction unit which reconstructs an image on the basis of a full projection data set corresponding to the determined cardiac phase.