Fig 3. Three VASO indices, that is, VASOTumor, VASOContra, and VASORatio, in grade II (n = 9), III (n = 20), and IV (n = 10) gliomas. Error bars indicate SDs. The units for VASOTumor and VASOContra are percentages. The index VASORatio is dimensionless. Significant differences (P < .05) for each pair are indicated by asterisks.