A computerized tomography device using an X-ray reconstructs a CT image of a sample and processes the CT image. Brown adipose candidate pixels are extracted based on a CT number of each pixel reconstructing the CT image. An erroneous pixel removal process is applied to the candidate pixels. In the erroneous pixel removal process, a boundary pixel removal process, a contraction and expansion process, or the like are applied. With this process, only the brown adipose pixels are extracted. An amount of brown adipose is determined from the brown adipose pixels and an evaluation value such as a brown adipose percentage is calculated based on the amount of brown adipose and amounts of other tissues.