What are the characteristic imaging features and common locations of intracranial lipomas, and how can they be differentiated from other fat-containing lesions like dermoids?

Intracranial lipomas are congenital lesions that can occur in all age groups. They are most commonly found in the interhemispheric fissure, often associated with agenesis of the corpus callosum, as well as the quadrigeminal plate and suprasellar regions. Key diagnostic features include high signal intensity on T1-weighted MRI due to fat content, chemical shift artifact, and fat suppression. The presence of flow voids or traversing cranial nerves within the lesion supports the diagnosis of lipoma over dermoid cysts, which may contain calcifications and do not typically have traversing structures. A common pitfall is mistaking them for dermoids or other cystic lesions, but the lack of enhancement and specific location can aid in differentiation.