Hemorrhage and hemorrhagic infections in the brain.

: Hemorrhage in the brain can be accurately staged using a combination of T1- and T2-weighted MR images. The MR appearance depends on the form of hemoglobin present and on whether hemolysis has occurred. The stages of hemorrhage distinguishable by MR imaging are: hyperacute (less than 1 day, intracellular oxyhemoglobin), acute (1-3 day, intracellular methemoglobin), late subacute (7-14 days, extracellular methemoglobin) and chronic (14+ days, hemosiderin rim).