Recurrent Malignant Gliomas (RMG) have a very short survival time, and re-operation risk is large and failed to significantly improve the prognosis of patients. At present, targeted therapy with bevacizumab is effective in prolonging the progression of patients However, a considerable proportion of recurrent malignant gliomas are insensitive to bevacizumab, and therefore, using noninvasive imaging methods to predict which RMG is sensitive to bevacizumab therapy prior to targeted therapy is very important On the other hand, the current evaluation of bevacizumab is mainly based on the degree of gadolinium enhancement and tumor volume changes, repeated gadolinium injection may increase the risk of gadolinium ion deposition of brain tissue, and because of Bevacizumab only acting as an anti-tumor angiogenesis, and a false response may occur in assessing efficacy, which is a bias in the overall assessment of bevacizumab.