Thick Dura/Arachnoid, Generalized
Yoshimi Anzai, MD, MPH
Judy Tan, MD
DIFFERENTIAL DIAGNOSIS
Common
Dural Thickening, Post-Operative
Metastases, Meningeal
Subdural Hematoma, Chronic
Meningitis
Intracranial Hypotension
Less Common
Neurosarcoid
Lymphoma, Metastatic, Intracranial
Hypertrophic Pachymeningitis
Meningioma
Rare but Important
Pseudotumor, Intracranial
Extramedullary Hematopoiesis
ESSENTIAL INFORMATION
Key Differential Diagnosis Issues
Dura is a thick dense fibrocollagenous sheet that is attached to skull at sutures
Arachnoid is a thin layer, loosely attached to the dura & contains arachnoid villi
Helpful Clues for Common Diagnoses
Dural Thickening, Post-Operative
Post-operative dural enhancement may appear within hours, last months/years
Metastases, Meningeal
Smooth or nodular enhancement; usually accompanied by adjacent skull lesions
Subdural Hematoma, Chronic
Smooth dural enhancement
MR sequences reveal blood products (GRE)
Meningitis
Dura/arachnoid pattern in meningitis less common than pia/subarachnoid
Intracranial Hypotension
Diffuse dural enhancement typical
“Slumping midbrain”, low tonsils & subdural effusions/hematomas
Helpful Clues for Less Common Diagnoses
Neurosarcoid
Dural thickening & enhancement
Predilection for basal cisterns
Lymphoma, Metastatic, Intracranial
Usually diffuse, multifocal with underlying bone involvement
May selectively affect meninges
Hypertrophic Pachymeningitis
Diffuse dural thickening & enhancement
Idiopathic; etiology often undetermined even with biopsy
Meningioma
Focal or diffuse dural enhancement
May see adjacent bone changes
Multiple associated with NF2
Helpful Clues for Rare Diagnoses
Pseudotumor, Intracranial
Enhancing, infiltrative meningeal mass
Predilection for cavernous sinus region & basal meningesRelated posts:
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