Abstract: An image processing element 9 of the present invention includes a weighting factor setting element 9a that sets up a weighting factors wnn, wbi of the weight addition combing a nearest neighbor interpolation and a bilinear interpolation based on an absolute value |Ibi?Inn| of the difference between the pixel value acquired by the nearest neighbor interpolation and the pixel value Inn acquired by the bilinear interpolation; and a weight addition element 9b that implement a weighting addition based on the set-up weighting factors wnn, wbi. A reconstructed image can be acquired by arranging the backprojection pixel value Inew every pixel following the weighting.