T2 hypointensity

Caused by T2 shortening

• High cellularity (also will have restricted diffusion)
  • High nucleus:cytoplasm ratio producing low lesional water content (eg. lymphoma and medulloblastoma)
• Acute hematoma (intracellular deoxyhemoglobin)
• Early subacute hematoma (intracellular methemoglobin)
• Chronic hematoma (extracellular ferritin, hemosiderin)
• Calcification
• Fibrous tissue
• Desiccated secretions in the paranasal sinuses