A program for determining an indicator relating to bone metastasis on the basis of a SPECT image or other three-dimensional nuclear medicine image. An image processing device realized by executing the program is provided with an image data acquiring unit (10) to which data of a CT image and a SPECT image of a subject are inputted, a bone region extraction unit (20) for extracting a bone region in the CT image, a bone region specifying unit (21) for specifying a bone region of the SPECT image that corresponds to the bone region in the CT image, a normalization unit (22) for normalizing pixel values of the bone region in the SPECT image, a bone metastasis region extraction unit (23) for determining a bone metastasis region having pixel values equal to or greater than a predetermined threshold value in the bone region in the normalized SPECT image, and an indicator calculation unit (24) for determining an indicator relating to bone metastasis on the basis of the volume of the bone region and the volume of the bone metastasis region.本發明係用以基於SPECT影像等之三維核醫學影像而求出關於骨轉移的指標之程式。藉由執行程式而實現之影像處理裝置係具備有：影像資料獲取部(10)，其輸入受驗者之SPECT影像及CT影像之資料；骨區域抽出部(20)，其抽出在CT影像中之骨區域；骨區域特定部(21)，其特定與CT影像中之骨區域對應的SPECT影像之骨區域；正規化部(22)，其針對SPECT影像中之骨區域之像素值進行正規化；骨轉移區域抽出部(23)，其求出於正規化後之SPECT影像中之骨區域，具有既定之臨限值以上之像素值的骨轉移區域；及指標計算部(24)，其基於骨區域之體積及骨轉移區域之體積，求出關於骨轉移的指標。
