Figure 4a: High mean ADC in 70-year-old man with partially resected glioblastoma multiforme. (a) Transverse contrast-enhanced T1-weighted MR image shows rim-enhancing mass in left temporal lobe. (b) Transverse T2-weighted MR image shows hyperintense resection cavity in central portion of mass, which is surrounded by hyperintense abnormality consistent with vasogenic edema or unenhancing tumor. Regions of interest in solid portion of mass (1) and contralateral normal white matter (2) indicate sites of ADC measurement for (c) transverse ADC map, which shows ADC in tumor is 183% of that in normal brain, corresponding to low cell density and nuclear-to-cytoplasmic ratio and abundant extracellular matrix seen at histologic analysis. (Reprinted, with permission, from reference 79.)