PROBLEM TO BE SOLVED: To provide an X-ray CT apparatus that can prevent image quality from degrading by eliminating discontinuity at a border of image regions.MEANS FOR SOLVING THE PROBLEM: The X-ray CT apparatus according to an embodiment of the present invention comprises: control means that controls top board moving means and imaging means so as to irradiate a subject with an X-ray each time when moving the top board in the body axis direction of the subject by a predetermined feed amount such that an imaging region of the subject is moved and imaged collection means that collects projection data of each imaging region reconstitution means that reconstitutes tomographic images of the subject for each size of a predetermined reconstitution region on the basis of the projection data of each of the imaging region and control means that has a scan control mode corresponding to the feed amount and a reconstitution control mode corresponding to the size of the reconstitution region, and outputs, upon receiving designation of the scan control mode, the feed amount corresponding to the designated mode to the top board moving means, and outputs, upon receiving designation of the reconstitution control mode, the size of the reconstitution region corresponding to the designated mode to the reconstitution means.SELECTED DRAWING: Figure 1
