Abnormal meningeal morphology Leptomeningeal enhancement 2018-09-30T15:02:42Z Contrast material enhancement for cross-sectional imaging in computed tomography and magnetic resonance imaging can be related to intravascular (vascular) enhancement and interstitial (extravascular) enhancement. Contrast material enhancement of the pia mater or enhancement that extends into the subarachnoid spaces of the sulci and cisterns is leptomeningeal enhancement. Leptomeningeal enhancement is usually associated with meningitis, which may be bacterial, viral, or fungal. The primary mechanism of this enhancement is breakdown of the blood-brain barrier without angiogenesis.