The difference in FA decreases in peritumoral normal-appearing WM between gliomas and meningiomas was significant, and the difference in FA decreases in peritumoral hyperintense regions between these tumors approached but did not reach significance. These findings may indicate a role for diffusion MR imaging in the detection of tumoral infiltration that is not visible on conventional MR images.

Although anisotropy measurements were higher in compact than non-compact white matter in all three age groups, the increase in anisotropy was greater in non-compact white matter across each of the three groups. These data suggest that although myelination is initially greater in compact white matter, the change in myelination may be greater in noncompact white matter during the first few years after infancy.

All patients had decreases in FA ratios over time. The early group had higher initial FA ratios and lower subsequent decreases, which may indicate amelioration of the dysmyelinating process.

No abstract