Intracranial Hemorrhage Stages on MRI
| Stage | Timeline | T1 | T2 | Type of hemoglobin |
| Hyperacute | < 1 day | Iso to hypointense | Iso to hyperintense | Intracellular oxyhemoglobin |
| Acute | 1-3 days | Iso to hypointense | Hypointense | Intracellular deoxyhemoglobin |
| Early subacute | 3-7 days | Hyperintense | Hypointense | Intracellular methemoglobin |
| Late subacute | 7-28 days | Hyperintense | Hyperintense | Extracellular methemoglobin |
|
Chronic |
>28 days |
Hypointense |
Hypointense |
Hemosiderin |
Mnemonic: I Be, IdDy, BiDy, BaBy, DaDdy (I=Iso, B=Bright, D=Dark)
The above stages do not apply to intraspinal hemorrhage. Intraspinal hemorrhage is similar to hemorrhage in the rest of the body which has much more heterogeneous and unpredictable stages. Sometimes but not always intraspinal hemorrhage roughly follows the stages below:
Early (< 10 days) T1-ISO, T2-Hyper
Late (10-28 days) T1-Hyper, T2-Hyper
Chronic (>28 days) T1-Hypo, T2-Hypo