PROBLEM TO BE SOLVED: To produce an image that a display form of an area of non-deteriorated image quality, where projection data are relatively sufficient, is appropriately modified, and to provide the image which facilitates test and interpretation of radiogram, in an X-ray CT scanner having multiseriate X-ray detectors in a direction of body axis.SOLUTION: In the X-ray CT scanner 10, the projection data are collected while an X-ray source emitting an X-ray beam and the X-ray detectors having multiseriate detecting elements along the slicing direction are rotated around a rotational axis, and the CT image is reconstructed by back projection for cone angle of the X-ray beam. The X-ray CT scanner 10 has: an area-calculating part 55 which calculates information related to a position of an area of deteriorated image quality generated near the end of a collection range of the projection data by effects of cone angle, on the basis of a slicing position an image processor 67 which processes the CT image so as to differentiate the area of deteriorated image quality from the area of non-deteriorated image quality.COPYRIGHT: (C)2008,JPO&INPIT【課題】体軸方向に多列のX線検出器を有するX線CT装置において、投影データが相対的に十分である画質非劣化領域の表示形式を適切に変更処理した画像を生成し、検査及び読影を良好に行なうことができる画像を提供すること。【解決手段】X線ビームを照射するX線源とスライス方向に沿って多列の検出素子を具備するX線検出器とを回転軸を中心に回転させながら投影データを収集し、前記X線ビームのコーン角を考慮した逆投影処理を行なってCT画像を画像再構成するX線CT装置10は、コーン角の影響により投影データの収集範囲の端付近に生じる画質劣化領域の位置に関する情報を、スライス位置に基づいて演算する領域演算部55と、画質劣化領域と画質非劣化領域とを識別できるように、CT画像に対して画像処理を行なう画像処理部67とを有する。【選択図】 図2
