Gyral enhancement

Gyral enhancement, also known as gyriform, cortical, or grey matter enhancement, is a pattern of contrast enhancement in the superficial brain parenchyma that conforms to the serpentine morphology of the cerebral gyri. It should be distinguished from leptomeningeal enhancement, which is also serpentine but occurs on the brain surface and rather than within the parenchyma.

The causes are most commonly vascular or inflammatory, with subacute infarction being the most well described :

• vascular
  • recent cerebral (cortical) infarction 
    • subacute infarct with luxury perfusion and/or cortical laminar necrosis (after 6 days until up to 4 months following stroke )
    • acute ischemic stroke after thrombolysis/thrombectomy
    • venous infarct 
  • epileptic seizures (vasodilatory postictal state) 
  • migraine 
    • migrainous infarction
    • hemiplegic migraine  
    • stroke-like migraine attacks after radiation therapy (SMART) syndrome 
  • posterior reversible encephalopathy syndrome 
• inflammatory/infectious
  • viral encephalitis
    • herpes
  • cerebritis
    • tuberculosis 
• neoplastic
  • glioblastoma 
  • metastases 
• ​toxic
  • cortical laminar necrosis related to drug toxicity (immunosuppressants and chemotherapy)

These causes may be distinguished by clinical history and brain location.