1. A radiation image processing apparatus for reconstructing a CT image from a plurality of image data items of a subject to be inspected, the image data items taken from different angles, comprising: body-movement information extracting means for extracting information based on the subject from at least two image data items and calculating at least one change indicating a body movement of the subject based on the information; repeat-radiograph determination means for determining whether or not a repeat radiograph is required based on the at least one change; and CT reconstruction means for reconstructing a CT image from the plurality of image data items; wherein the CT reconstruction means starts reconstructing the CT image when a repeat radiograph is not required.