leptomeningeal enhancement
Pronunciation: lep-to-men-in-JEE-al
Abnormal contrast uptake in the pia mater and arachnoid layers covering the brain surface.
Full Definition
Leptomeningeal enhancement refers to abnormal contrast enhancement of the leptomeninges, which consist of the pia mater and arachnoid membrane that directly cover the brain and spinal cord surface. This enhancement pattern indicates inflammation, infection, or neoplastic infiltration of these delicate membranes. Common causes include bacterial or viral meningitis, carcinomatous meningitis, sarcoidosis, or inflammatory conditions. On post-contrast MRI, leptomeningeal enhancement appears as curvilinear enhancement following the brain surface and extending into the sulci, distinct from the thicker, more nodular enhancement typically seen with dural-based processes.
Usage
Usage note: Distinguish from pachymeningeal (dural) enhancement in radiological descriptions.
In Context
- "Diffuse leptomeningeal enhancement is seen throughout the cerebral sulci, raising concern for meningitis." — Emergency MRI report
- "The pattern of leptomeningeal enhancement suggests carcinomatous meningitis rather than infectious etiology." — Oncology imaging assessment