PROBLEM TO BE SOLVED: To reduce the influence of scattered radiation originating in the X-ray of the other party in a multi-tube type X-ray CT apparatus equipped with a plurality of pairs of an X-ray tube and detector.SOLUTION: The X-ray CT apparatus is equipped with a plurality of X-ray tubes 121, 122, a plurality of X-ray detectors 131, 132 corresponding to the plurality of X-ray tubes, respectively, a support mechanism 11 for supporting the X-ray tubes and the X-ray detectors rotatably around a single rotation shaft, a reconstruction part 23 for reconstructing image data on the basis of outputs from the X-ray detectors, and a plurality of filters 171, 172 which are respectively provided in the plurality of X-ray tubes and have characteristics in which an X-ray path length changes along a curve approximate to an inverted Gaussian curve from the rotation center to both ends of an X-ray beam.COPYRIGHT: (C)2007,JPO&INPIT【課題】X線管と検出器との複数のペアを装備するマルチチューブタイプX線CT装置において、相手方のX線に由来する散乱線の影響を低減すること。【解決手段】X線CT装置は、複数のX線管121、122と、複数のX線管にそれぞれ対応する複数のX線検出器131、132と、X線管とX線検出器とを単一の回転軸周りを回転自在に支持する支持機構11と、X線検出器の出力に基づいて画像データを再構成する再構成部23と、複数のX線管にそれぞれ設けられ、X線パス長が回転中心からX線の両端に向かって反転ガウス曲線に近似して曲線的に変化する特性を有する複数のフィルタ171、172とを具備する。【選択図】図1