In order to improve the tiling workability in manufacturing an X-ray detector and provide a technology for acquiring high-quality reconstruction images, when aligning a plurality of detector blocks (or detector modules) in a slice direction, a distance between adjacent X-ray detection elements between detector blocks (inter-block distance) is not matched with a distance between adjacent detector elements within a detector block (intra-block distance). Instead, between reference positions when manufacturing each detector block, output values at the positions, the number of which is the same as the number of X-ray detection elements between the reference positions and which are spaced at equal intervals, are estimated from the acquired raw data. Projection data is generated from the position and the raw data.
