Imaging stages of intracranial hemorrhage

Hyperacute: <24 hours

Intracellular oxyhemoglobin is the main blood product

• CT: Hyperdense
• T1: Isointense
• T2: Hyperintense or isointense
• T2*: Peripheral blooming
• DWI: Bright
• ADC: Dark

Acute: 1-3 days

Intracellular deoxyhemoglobin is the main blood product

• CT: Hyperdense
• T1: Isointense
• T2: Hypointense
• T2*: Increased blooming
• DWI: Dark
• ADC: Dark

Early subacute: >3 days to 1 week

Intracellular methemoglobin is the main blood product

• CT: Isodense
• T1: Hyperintense
• T2: Hypointense
• T2*: Increased blooming
• DWI: Dark
• ADC: Dark

Late subacute: 1 week to 14-28 days

Extracellular methemoglobin is the main blood product

• CT: Hypodense
• T1: Hyperintense
• T2: Hyperintense
• T2*: Low signal rim, variable center
• DWI: Bright
• ADC: Dark

Chronic: >14-28 days

Intracellular hemosiderin is the main blood product

• CT: Hypodense
• T1: Hypointense
• T2: Hypointense
• T2*: Low signal
• DWI: Dark
• ADC: Dark