Table 2.

Types of Hemorrhagic Transformation

	Definition	Clinical Significance
Hemorrhagic infarction 1 (HI1)	Hemorrhagic infarction with small petechiae within the stroke	Uncertain; may be a beneficial marker of reperfusion
Hemorrhagic infarction 2 (HI2)	Hemorrhagic infarction with confluent petechiae within the stroke	Uncertain
Parenchymal hematoma 1 (PH1)	Parenchymal hematoma with an organized clot <30% of stroke and mild mass effect	Often associated with neurological deterioration
Parenchymal hematoma 2 (PH2)	Parenchymal hematoma with a large organized clot and significant mass effect	Associated with neurological deterioration from mass effect