IDH1 and astrocytoma (excluding glioblastoma): When original MRI data (n = 57) were used in discriminating IDH-mutant grade 4 astrocytomas from IDH-wild-type GBMs, the best discriminatory performance (AUC = 0.93, ACC = 0.92, sensitivity = 1, specificity = 0.86, PR_AUC = 0.92) was obtained from solid/contrast enhancing, and core tumor (solid + necrotic region) overlaid on post-contrast T1-weighted images using various combinations of feature selection algorithms and machine learning classifiers.