This invention is to provide a method of obtaining fat mass by using dual-energy X-ray absorptiometry, which uses a dual-energy X-ray absorptiometry to irradiate a tissue part to generate tow digital images shot with X-rays of different energies. The calculation method at least comprises: a. dividing the tissue part into three or more sub-regions including fat tissue and non-fat tissue and b. utilizing alternating minimization method to calculate the mass component of each sub-region, so as to obtain the fat mass, wherein the tissue part includes internal organs. With the method of this invention, the fat mass of the tissue part can be directly and accurately obtained, and liver fat mass, intraperitoneal fat mass, and non-internal organ fat mass can be distinguished.本發明係提供一種利用雙能量X光吸收計量儀獲取脂肪質量的方法,係由雙能量X光吸收計量儀照射一組織部位,產生二張以不同能量X光拍攝之數位影像,其計算方法至少包括a.將該組織部位分為三個以上之分域,該些分域包含脂肪組織及無脂肪組織;以及b.利用交替最小化法計算各分域之質量分量,即可獲得脂肪質量;其中,該組織部位包含內臟。由本發明方法可直接且準確得到該組織部位之脂肪質量,並可區分肝臟脂肪質量、臟腔脂肪質量及非內臟脂肪質量。
