FIG 4. Increase in T1 relaxation rate of LE over NAWM (intensity of LE) for patients on the standard- or high-risk arm (light gray bars) and patients on the low-risk arm (black bars) of the treatment protocol. Statistical results from a nonparameteric one-sided Wilcoxon-Mann-Whitney test are shown for both within and between groups at each of the 4 time points. Quantitative MR measures were evaluated post 1, 4, and 7 courses of IV-MTX and at end of therapy (EOT).