General Guidelines for Temporal Evolution of Intracranial Hematomas

General Guidelines for Temporal Evolution of Intracranial Hematomas AT 1.5 T

Clinical biochemical form Approximate stage Time of appearance Intensity on T1-weighted imagea Intensity on T2-weighted imagea Oxyhemoglobin in RBCs Hyperacute Immediately to first several hours ≈ ↑ Deoxyhemoglobin in RBCs Acute Hours to days ≈, ↓ ↓↓ Methemoglobin in RBCs Early subacute First several days ↑↑ ↓↓ Extracellular methemoglobin Subacute to chronic Days to months ↑↑ ↑↑ Ferritin and hemosiderin Remote Days to indefinitely ≈, ↓ ↓↓ RBC, red blood cell. aSignal intensity is relative to normal brain parenchyma.