PROBLEM TO BE SOLVED: To realize an X-ray CT system for discribing a contrast agent in an easily discriminable manner even under a condition difficult to grasp the state of the contrast agent in a usual tomographic image.SOLUTION: The X-ray CT system has a photographing part for performing the reconstitution of an image on the basis of the projection data acquired by scanning a specimen, in which the contrast agent is injected, by X rays and a control part for controlling the same. In the control part, X-ray energy is alternately changed over two stages in a view unit during the scanning, two kinds of tomographic images different in X-ray energy are reconstituted on the basis of the projection data acquired by the scanning and the concentration distribution image of the contrast agent is formed on the basis of two kinds of two tomographic images and the energy characteristics of the contrast agent.COPYRIGHT: (C)2008,JPO&INPIT【課題】通常の断層像では造影剤の状態の把握が困難な条件においても、造影剤を容易に識別可能に描出するX線CT装置を実現する。【解決手段】X線CT装置は、造影剤が注入された被検体をX線でスキャンして得られる投影データに基づいて画像再構成を行う撮影部とそれを制御する制御部を有し、前記制御部は、前記スキャンの遂行中にX線エネルギーをビュー単位で交互に2段階に切換えさせ、前記スキャンによって得られた投影データに基づいてX線エネルギーが異なる2種類の断層像を再構成させ、前記2種類の断層像と造影剤のエネルギー特性に基づいて造影剤の濃度分布像を作成させる。【選択図】図9
