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Postcontrast MRI of cranial meninges: leptomeningitis versus pachymeningitis

F Kioumehr1, M R Dadsetan, N Feldman

  • 1Department of Radiological Sciences, Olive View-UCLA Medical Center, Sylmar 91342, USA.

Journal of Computer Assisted Tomography
|September 1, 1995
PubMed
Abstract

Insights

Infectious meningitis typically shows leptomeningeal enhancement on MRI, while carcinomatous meningitis often presents as pachymeningeal enhancement. Recognizing these patterns aids in differential diagnosis.

Area of Science:

  • Radiology
  • Neurology
  • Pathology

Background:

  • Meningeal enhancement on postcontrast MRI is a key indicator of various central nervous system disorders.
  • Differentiating between infectious and carcinomatous meningitis is crucial for appropriate patient management.

Purpose of the Study:

  • To characterize patterns of meningeal enhancement in postcontrast MR images.
  • To correlate these enhancement patterns with specific clinical disorders, particularly infectious versus carcinomatous meningitis.

Main Methods:

  • Retrospective review of 83 patients with meningeal enhancement on head MRI.
  • Classification of enhancement patterns into leptomeningeal (pia and arachnoid) and pachymeningeal (dura).
  • Categorization into five etiologic subgroups: carcinomatous, infectious, inflammatory, reactive, and chemical.

Main Results:

  • Infectious meningitis predominantly showed leptomeningeal enhancement (100% of cases).
  • Carcinomatous meningitis primarily exhibited pachymeningeal enhancement (83% of cases), with leptomeningeal enhancement seen in 17% often due to direct tumor spread.
  • Reactive and inflammatory meningitis predominantly showed pachymeningeal enhancement.

Conclusions:

  • Leptomeningeal enhancement is characteristic of infectious meningitis.
  • Pachymeningeal enhancement is more indicative of carcinomatous meningitis.
  • Identifying these distinct MRI patterns can assist in differentiating between infectious and carcinomatous meningitis.

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