Fatty falx cerebri
A fatty falx cerebri is a common finding, seen (according to one study) 7.3% of patients, and is explained by fat being a normal feature of the extradural neural axis compartment located between the two visceral layers of the falx.
A fatty falx is an incidental finding and should not be mistaken for:
- ruptured intracranial dermoid: multiple droplets of fat in the subarachnoid space
- intracranial lipoma: frequently inter-hemispheric and associated agenesis of the corpus callosum
- osseous metaplasia of the falx cerebri: fat within the medullary space of an ossified falx (also common)
- pneumocephalus: ROI should be no lower than -120HU (beware volume averaging)
- 1. SS Chen et al "Fat in the cerebral falx" Zhonghua Yi Xue Za Zhi (Taipei). 2000 Nov ;63 (11):804-8