Falx Lesions

Falx Lesions

Miral D. Jhaveri, MD



  • Physiologic Calcification, Dura

  • Osseous Metaplasia

  • Subdural Hematoma, Acute

  • Meningioma

  • Metastases, Meningeal

Less Common

  • Neurosarcoid

  • Extra-Axial Empyema

Rare but Important

  • Intracranial Hypotension

  • Hypertrophic Pachymeningitis

  • Erdheim-Chester Disease

  • Rosai-Dorfman Disease

  • Extramedullary Hematopoiesis

  • Chondrosarcoma

  • Solitary Fibrous Tumor

  • Hemangiopericytoma

  • Dural A-V Fistula


Key Differential Diagnosis Issues

  • Smooth dural thickening, enhancement usually benign

  • “Lumpy-bumpy” not always malignant!

Helpful Clues for Common Diagnoses

  • Physiologic Calcification, Dura

    • Common in the middle-aged/elderly, falx or tentorium

    • Dense amorphous Ca++ plaques

  • Osseous Metaplasia

    • Different from simple “dense dural calcification” on NECT

    • Look for cortex and medullary space (bone CT)

    • Most common in anterior/mid-falx

    • Mottled hyperintensity (T1WI) surrounded by hypointense dense cortex (T2WI)

    • “Blooms” on GRE

    • True falx lipoma rare (look for chemical shift artifact)

  • Subdural Hematoma, Acute

    • Can be isolated; may extend along convexities, tentorium

    • Look for signs of nonaccidental trauma (shaking) in children with interhemispheric SDH

  • Meningioma

    • Common location for meningiomas

    • Most arise along middle 1/3rd of the superior sagittal sinus (SSS)

    • May grow into, occlude SSS

    • Look for “dural tail” sign

  • Metastases, Meningeal

    • Can mimic meningiomas

Helpful Clues for Less Common Diagnoses

  • Neurosarcoid

    • Nodular, “lumpy-bumpy” falx

  • Extra-Axial Empyema

    • Frontal sinusitis → empyema ± posterior extension along falx

    • Rim-enhancement, restricts on DWI

Aug 7, 2016 | Posted by in NEUROLOGY | Comments Off on Falx Lesions

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