Fig. 1

The examples of MRI images and ADC histograms from different grades of meningioma tumors in one slice of brain. A An ADC image with grade I (contoured with red line). B An ADC image with grade II (contoured with purple line). C An ADC image with grade III (contoured with blue line). D A volumetric intensity histogram of grade I. E A volumetric intensity histogram of grade II. F A volumetric intensity histogram of grade III