PROBLEM TO BE SOLVED: To provide an image processing device capable of easily and accurately extracting a contour of a desired region from a tomographic image. An operation receptionist that accepts a specific operation for specifying a reference reference pixel among an image storage unit 101 in which a tomographic image is stored and a first pixel indicating a first tissue included in the tomographic image. A contour extraction unit that extracts a contour having a boundary between the unit 102, a first pixel continuous with a reference pixel specified by a specific operation, and a second pixel indicating a second structure different from the first structure. It is provided with 103 and an output unit 104 that outputs the contour extracted by the contour extraction unit 103. [Selection diagram] Fig. 1【課題】断層画像から容易にかつ精度よく所望の領域の輪郭を抽出できる画像処理装置を提供する。【解決手段】断層画像が格納される画像格納部１０１と、断層画像内に含まれる第一の組織を示す第一の画素のうちの、基準となる基準画素を特定する特定操作を受け付ける操作受付部１０２と、特定操作により特定される基準画素に連続する第一の画素と、第一の組織とは異なる第二の組織を示す第二の画素との境界を有する輪郭を抽出する輪郭抽出部１０３と、輪郭抽出部１０３が抽出した輪郭に関する出力を行う出力部１０４とを備えた。【選択図】図１
