PROBLEM TO BE SOLVED: To provide an X-ray CT apparatus which can scan a subject in a supine position, a standing position or a sitting position with X-rays while downsizing the apparatus.SOLUTION: An X-ray CT apparatus includes a supporting part, a rotational part, a tilt mechanism and a tilt driving part. The tilt mechanism part includes a first gear, and a first pinion. The rotational part is provided with an opening part, and is turnably supported around the supporting axis pivotally supported by the supporting part. The tilt mechanism part tilts the rotational part. The tilt driving part drives the tilt mechanism part. The first gear is turnably fixed to the rotational part around the supporting axis pivotally supported by the supporting part, and is provided with a plurality of teeth parts on an outer peripheral surface in an angle range of at least 90 degrees on the circumference centering around the supporting axis. The first pinion is turnably structured around a turning axis in a direction the same as the turning axis of the first gear, engages with the first gear and is driven by the tilt driving part.COPYRIGHT: (C)2016,JPO&INPIT【課題】装置の小型化を図りつつ、臥位や立位や座位の被検体に対しX線のスキャンが可能なX線CT装置を提供する。【解決手段】実施形態のX線CT装置は、支持部と、回転部と、チルト機構部、チルト駆動部とを含む。チルト機構部は、第1ギアと、第1ピニオンとを含む。回転部は、開口部が形成され、支持部に軸支された支軸回りに回動可能に支持される。チルト機構部は、回転部をチルトさせる。チルト駆動部は、チルト機構部を駆動させる。第1ギアは、支持部により軸支された支軸回りに回動可能に回転部に固定され、支軸を中心とする円周の少なくとも90度の角度範囲の外周面に複数の歯部が形成される。第1ピニオンは、第1ギアの回動軸と同一方向の回動軸回りに回動可能に構成され、第1ギアに噛合し、チルト駆動部により駆動される。【選択図】図1
