PROBLEM TO BE SOLVED: To extract a specific region (region of interest) of an object based on an MRI image in a short time with high accuracy. SOLUTION: A given target MRI image is divided into a plurality of parts using a standard image in which a plurality of parts including a specific part are clearly defined, and a specific part target image corresponding to the specific part is generated in advance. A second number of specific site label images having a high similarity to the specific site target image is selected from the prepared first number of specific site label images having different shapes, and the selected second number is specified. In the image registration between the part label image and the specific part target image, the image part that best represents the function area included in the specific part is extracted. [Selection diagram] Fig. 6【課題】ＭＲＩ画像に基づく，対象の特定部位（関心領域）の抽出を短時間でかつ高精度に行なう。【解決手段】特定部位を含む複数の部位が明示された標準的画像を用いて所与の対象ＭＲＩ画像を複数の部位に分割して上記特定部位に対応する特定部位対象画像を生成し，あらかじめ用意された形状の異なる第１の数の特定部位ラベル画像から上記特定部位対象画像と類似性の高い第２の数の特定部位ラベル画像を選択し，そして上記選択された第２の数の特定部位ラベル画像と上記特定部位対象画像との画像位置合わせにおいて，特定部位内に含まれる関数領域を最もよく表わす画像部分を抽出する。【選択図】図６
