An X-ray CT apparatus includes a first setting device configured to set on a scout image of a subject, a reconstruction range of a tilt image based on a desired tilt angle such that the tilt image includes a region of interest of the subject, a second setting device configured to set on the scout image a range as a scan range for a non-tilt scan, the range being placed on an inner side of a scan range necessary to reconstruct the tilt image with respect to all scan spaces in the reconstruction range, wherein the range includes the region of interest, a scan execution device configured to execute the non-tilt scan on the scan range, and a reconstruction device configured to reconstruct the tilt image including at least the region of interest with respect to the reconstruction range based on projection data acquired during the non-tilt scan.
