Table 2.
Aging of Blood Products on MR Imaging
| Stage | Time | Hemoglobin State | T1 Signal Intensity | T2 Signal Intensity |
|---|---|---|---|---|
| Hyperacute | Less than 24 hours | Intracellular Oxyhemoglobin | Isointense | Hyperintense |
| Acute | Less than 48 hours | Intracellular Deoxyhemoglobin | Isointense | Hypointense |
| Early Subactue | 2–14 days | Intracellular Methemoglobin | Hyperintense | Hypointense |
| Late Subacute | 10–21 days | Extracellular Methaemoglobin | Hyperintense | Hyperintense |
| Chronic | Greater than 21 days | Hemosiderin | Hypointense | Hypointense |
Note: Complied from data presented by Chalela, Aygun, and Bradley.