When photographing is started, pulsation of a subject is detected and a pulsation period T is measured. A standstill period is determined and the rotation time S of a rotation table is calculated according to the equation S=nT (where n denotes an odd number). When rotation is started and a predetermined speed and a predetermined angle are attained, X-ray exposure is started, and the exposure is stopped when a predetermined number of views are obtained. After scan data is collected, a motion area is detected and data-rearrangement is performed, and a half-scan reconstructed image is created by using the rearranged scan data. When an artifact is identified by reconstructed-image evaluation, a retry is made. Subsequently, a standstill period is changed, the data rearrangement is performed again, and half-scan reconstruction and image evaluation are performed again. When the image evaluation is successful, three-dimension-voxel coupling is performed.