PROBLEM TO BE SOLVED: To improve the detection accuracy of a characteristic point of a region desired to be photographed.SOLUTION: This image data processor sets a region ROI of interest inside a region where a liver of coronal projection data is projected, and calculates an average value m1, a standard deviation σ1, an average value mn, and a standard deviation σn. Based on a difference between a signal value of each pixel and a signal value of an adjacent pixel, the image data processor determines a candidate point representing the position of an SI direction of the lower end of the liver. After determining the candidate point, the image data processor selects the candidate point where position coordinates of the SI direction become a downmost point from the candidate points.COPYRIGHT: (C)2013,JPO&INPIT【課題】撮影したい部位の特徴点の検出精度を向上させる。【解決手段】コロナル投影データの肝臓が投影された領域の内側に関心領域ROIを設定し、平均値ml、標準偏差σl、平均値mn、および標準偏差σnを算出する。そして、各ピクセルの信号値と、隣接するピクセルの信号値の差とに基づいて、肝臓の下端のSI方向の位置を表す候補点を決定する。候補点を決定したら、候補点の中から、SI方向の位置座標が最下点となる候補点を選択する。【選択図】図4
