Subependymal gray matter heterotopia | Figure 1
Subependymal gray matter heterotopia
Axial T1 FLAIR MRI shows subependymal gray matter heterotopia (arrowhead), the most commonly observed form of gray matter heterotopia. The differential diagnosis for this finding includes subependymal nodules that occur in tuberous sclerosis complex. Gray matter heterotopia is distinguished from subependymal nodules of tuberous sclerosis by the signal intensity of the nodule; in tuberous sclerosis, the T2 signal of subependymal nodules is higher than that of normal gray matter while nodules in gray matter heterotopia are isointense to gray matter. Patients with tuberous sclerosis may also have additional stigmata such as subcortical tubers and subependymal giant cell astrocytomas.