Abstract: Diabetes mellitus is a common and frequently occurring disease which seriously threaten the health of human beings.Type 1 and type 2 diabetes respectively results from being destroyed and insufficient beta-cell mass.The associated symptoms appear until 50%-60%decrease of beta-cell mass.Because pancreas is deeply located in the body, with few beta-cell mass, the current methods of clinical diagnosis are invasive and late.So diagnosis of metabolism disease of beta-cell early and non-invasively becomes more and more popular, imaging diagnosis of diabetes mellitus becomes the focus of researches, but how to estimate the mass of beta-cellis still an important subject in imaging technology.