PROBLEM TO BE SOLVED: To provide an X-ray CT apparatus capable of obtaining tomographic images of uniform image quality among a plurality of tomographic images within a tomographic region even if there are areas with inefficiency in the degree of hardening of radiation quality or the dose of X-rays within the tomographic region of a subject.SOLUTION: The X-ray CT apparatus 100 reconstructs an image based on X-ray projection data obtained by scanning the tomographic region of the subject HB with X-rays from an X-ray generating part 21. The X-ray CT apparatus comprises: an X-ray control part 22 for changing the radiation quality of the X-ray beams emitted from the X-ray generating part during the scan according to the position of the subject in the direction of the body axis within the tomographic region of the subject and an image reconstruction part 34 for reconstructing a plurality of tomographic images of the uniform X-ray beam radiation quality within the tomographic region based on the X-ray projection data with the changed X-ray beam radiation quality.COPYRIGHT: (C)2010,JPO&INPIT【課題】被検体の撮影領域内に、線質硬化の程度やX線線量が不足する部分がある場合においても、当該撮影領域内の複数の断層像間において、均一な画質の断層像を得ることが可能なX線CT装置を提供する。【解決手段】X線CT装置(100)は、被検体(HB)の撮影領域を、X線発生部(21)からのX線でスキャンして得られるX線投影データに基づいて画像再構成を行うX線CT装置である。そして、X線CT装置は、被検体の撮影領域内の被検体の体軸方向の位置に応じてスキャン遂行中にX線発生部から照射されるX線ビーム線質を変化させるX線制御部(22)と、変化したX線ビーム線質によるX線投影データに基づいて、撮影領域内において均一なX線ビーム線質相当の複数の断層像を画層再構成する画像再構成部(34)と、を備える。【選択図】図1
