FIG 2. A 37-year-old man with PCNSL (patient 5 in Table 1). Change of zone II abnormality with partial resolution. Baseline Z score –3.00; end of treatment Z score –.44. (This patient had multiple enhancing tumor foci, consequently with multiple zone II abnormalities, some of them partially, some of them completely resolved. See also Figure 3.)

A, Baseline axial T2-weighted image demonstrates large zone II areas in the bilateral parietal periventricular white matter (arrows). The heterogeneous low signal intensity areas directly adjacent to the posterior aspect of the ventricles represent the solid tumor mass (arrowheads).

B, End-of-treatment axial T2-weighted image shows only small, residual zone II in the bilateral parietal periventricular white matter (arrows).