title: Differentiation between meningeal fibrosis and chronic subdural hematoma after ventricular shunting: value of enhanced CT and MR scans.
abstract: Unenhanced CT in four patients with long-standing ventricular shunts demonstrated bilateral low-density extraaxial collections that were indistinguishable from chronic subdural hematomas. After administration of contrast material, however, there was marked enhancement of the collections as well as prominent paratentorial and parafalcial enhancement. MR imaging, performed in three patients, demonstrated the extent and paradural location of the collections better than CT did, but, as with unenhanced CT, the collections could not be distinguished from chronic subdural hematomas. On follow-up CT and MR, there was no change in the size, enhancement, or intensity of the collections. Histologic examination of biopsies from two patients demonstrated fibrosis of the meninges characterized by granulation tissue and collagen deposition. Meningeal fibrosis is a rare postshunt phenomenon that may mimic chronic subdural hematoma on unenhanced CT and MR. Recognition of this entity is important, particularly if therapeutic intervention is being considered. Therefore, an enhanced CT or enhanced MR scan should be obtained in chronically shunted patients to differentiate between a drainable chronic subdural hematoma and meningeal fibrosis.
authors.affiliation: Department of Radiology, New York Hospital-Cornell Medical Center, NY 10021.
authors.forename: S
authors.initials: S
authors.lastname: Destian
authors.forename: L A
authors.initials: LA
authors.lastname: Heier
authors.forename: R D
authors.initials: RD
authors.lastname: Zimmerman
authors.forename: S
authors.initials: S
authors.lastname: Morgello
authors.forename: M D
authors.initials: MD
authors.lastname: Deck
mesh_terms: D000328:Adult; D000368:Aged; D001706:Biopsy; D002552:Cerebral Ventricles / Q000473:pathology; D002557:Cerebrospinal Fluid Shunts / Q000009:adverse effects*; D002908:Chronic Disease; D003937:Diagnosis, Differential; D005260:Female; D005355:Fibrosis; D006408:Hematoma, Subdural / Q000000981:diagnostic imaging / Q000209:etiology / Q000473:pathology*; D006801:Humans; D007089:Image Enhancement; D008279:Magnetic Resonance Imaging; D008297:Male; D008578:Meninges / Q000000981:diagnostic imaging / Q000473:pathology*; D008875:Middle Aged; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed