FIG 1. Axial MR images of a 4-year-old patient (case 1) obtained on day 30 after bone marrow transplantation. The patient presented with lethargy and focal seizures secondary to CSA therapy. The T2 signal abnormalities corresponded to areas of increased diffusion, suggesting that these areas of cerebral edema were caused by extravasation of fluid and not cerebral ischemia.

A, A fluid-attenuated inversion-recovery image shows confluent cortical and juxtacortical signal alteration in both occipital lobes (arrows).

B, The ADC map at the same level reveals increased diffusion in the regions of prolonged T2 signal (arrows). (Normal brain = 1.00 x 10^-3 mm²/second, abnormal areas = 1.42.)