IDH1 and central nervous system cancer: However, the IDH-mutant_1p/19qret without AB/FS mismatch could not be differentiated from the IDH-mutant_1p/19qcodel, suggesting that the presence of T2/FLAIR mismatch, usually not assessed in the literature, is an important parameter to consider when assessing the efficiency of the CEST metrics to stratify gliomas.