When sukiyanoguramu it photographs the suffering inspection body, the water and the equivalence which closely resemble to the fault plane of the photographing region of the feature quantitative karaso of projection value profile of the photographing region which is obtained it draws up the human body approximate elliptic model which possesses x-ray attenuation factor, whether or not this the human body approximate elliptic model which was drawn up as the model of that photographing region the appropriateness it judges from another feature quantity of projection value profile of the aforementioned photographing region, as inadequacy it is judged when draws up the correction human body approximate elliptic model on the basis of furthermore another feature quantity of projection value profile of the aforementioned photographing region, as the appropriateness is judged the aforementioned water and equivalenceUsing the human body approximate elliptic model which possesses x-ray attenuation factor, when it is judged as inadequacy, using the aforementioned correction human body approximate elliptic model, in order for specified target picture SD value to be maintained in each circumference position in the photographing region in regard to the coaxial tomography which is reconstructed on the basis of the x-ray which transmitted the suffering inspection body, the x-ray CT device where tube electric current of x-ray source is modulated is controlled.被検体をスキャノグラム撮影し、得られた撮影部位の投影値プロファイルの特徴量からその撮影部位の断層面に近似する水と等価なX線減弱係数を有する人体近似楕円モデルを作成し、この作成した人体近似楕円モデルがその撮影部位のモデルとして適切か否かを前記撮影部位の投影値プロファイルの別の特徴量から判断し、不適切と判断された場合は前記撮影部位の投影値プロファイルの更に別の特徴量に基づいて修正人体近似楕円モデルを作成し、適切と判断された場合は前記水と等価なX線減弱係数を有する人体近似楕円モデルを使って、不適切と判断された場合は前記修正人体近似楕円モデルを使って、被検体を透過したX線に基づいて再構成される断層像に関してその撮影部位にいづれの周回位置においても所定の目標画像SD値が維持されるようにX線源の管電流が変調制御されるX線CT装置。
