IDH1 and oligodendroglial tumor: In addition to differentiating glioma with respect to the WHO grading, studies have investigated the ability to discriminate between tumors according to IDH mutation status, and maximal FA and the ratio of maximal FA (maximal FA divided by the contralateral normal FA) were significantly different between oligodendroglial tumors with IDH mutations and those without mutations, yielding areas under the curve (AUCs) of 0.79 and 0.82, respectively.80