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Haemorrhagic Infarction and Transformation

Learning objectives

  • Learning
  • Understand
  • Integrate
  • Reflect

Haemorrhagic Infarction (HI)/Transformation
  • Following an Ischaemic stroke there can be a form of secondary haemorrhage into the infarcted tissue and this is often termed haemorrhagic infarction or transformation.
  • It is more common in embolic strokes, larger stroke and following spontaneous or therapeutically driven recanalisation with thrombolysis (especially intraarterial) and/or thrombectomy.
  • Thrombectomy seems to have an increase of asymptomatic HI but symptomatic HI is unaffected. The rate seems to be higher with delayed recanalisation e.g. Alteplase after 3 hours.
  • Poorly controlled hypertension is a risk and is one of the reasons to control blood pressure after thrombolysis. Severe hyperglycaemia may also be a risk.
  • It tends to happen early within the first few days, but it can be as late as 2 weeks. It is often clinically silent especially as at this time there is rarely any need to do brain imaging.
  • Blood is more clearly seen on MRI GRE and T2 star. Often the response is to omit antiplatelets for several days.
  • If the patient presents late it can be difficult to distinguish haemorrhagic transformation from a primary intracerebral haemorrhage.
  • HT is possibly due to the reopening of occluded blood vessels with flow into tissues with a damaged capillary bed due to local ischaemic necrosis.
  • It is always a worry in re-establishing flow that haemorrhage will occur. However, there is a distinct difference between mild to moderate haemorrhage into already damaged brain and de novo haemorrhage into undamaged brain adding to the overall stroke burden.
Haemorrhagic Infarction Type 1Small hyperdense petechiaeNo change
Haemorrhagic Infarction Type 2Confluent hyperdensity in infarct zone no mass effectNo change
Parenchymal haematoma type 1 (PH1) Confluent hyperdensity in infarct zone taking up < 30% infarct area with some mass effectNo change
Parenchymal haematoma type 2 (PH4) Confluent hyperdensity in infarct zone taking up > 30% infarct area and beyond with oedema and mass effect Increased