NeuroradiologySubependymal nodule
Subependymal nodules are defined as small
nodular masses which originate in the subependymal region of the lateral ventricles and protrude into the ventricular cavity.
They may represent subependymal hamartomas of tuberous sclerosis or nodular heterotopia of grey matter.
The two entities can be differentiated based on CT appearance since in tuberous sclerosis the nodules are more irregular and frequently calcified.
On MR studies subependymal hamartomas of tuberous sclerosis exhibit signal intensity slightly different from the cortical grey matter and show variable enhancement after contrast administration. On the contrary heterotopias are isointense to the cortex in all MR imaging sequences and do not enhance.
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