Fig. 2.

Histograms of dMRI parameters. Panel A shows distributions of parameter-values within the ROIs. Part 1 shows MD, MK and MK_A distributions in the whole-tumor ROI among soft, variable, and firm consistency (distribution differences indicated by yellow arrows). Part 2 shows distributions of MK_A, MK_I and MK in psammomatous and other meningioma types in the whole-tumor ROI. Part 3 shows the MK_I distribution in grade I and II meningiomas within the rim ROI. The histograms suggest that it may be valuable to consider different distribution characteristics—their percentiles or standard deviation—shown by yellow arrows. Panel B shows effect sizes for different distribution characteristics (10th, 25th, 50th, 75th, 90th and standard deviation) as measured by Cohen’s d (defined according to Eq. (2)) averaged across all dMRI parameters (MD, FA, MK, MK_A and MK_I and S₀). For consistency, grade and type the highest effect size is found for the 10th, 10th, and 50th percentile, respectively. For the case of grade, however, only standard deviation within MK_I was significantly different between the grades. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)