Fatty falx cerebri

A fatty falx cerebri is a benign entity in which there is fat within the extradural neural axis compartment located between the two visceral layers of the falx. 

According to one study, it is a common finding seen in approximately 7.3% of patients 1. This can be more common in older patients 1.

Patients are usually asymptomatic and found incidentally.

The characteristic finding on both CT and MRI is fat within the falx cerebri.

On CT, there is midline homogenous fat attenuation (hence negative CT attenuation values) in the falx cerebri

MRI with and without fat saturation are able to make the diagnosis easily.

Signal characteristics are that of fat: 

  • T1: high signal intensity
  • T2: high signal intensity 
  • T1 C+ (Gd): no enhancement
  • Fat saturated sequences: low signal 

No treatment is recommended as this is an asymptomatic and incidental finding.

A fatty falx is an incidental finding and should not be mistaken for:

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Article information

rID: 1329
Synonyms or Alternate Spellings:
  • Fatty falx

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Cases and figures

  • Case 1
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  • Fatty falx : T1
    Case 2 : T1
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  • Case 3
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