Teaching File - Cerebellar Haematoma Evolution 7 days

These two T2-weighted MR images show a cerebellar haematoma at 7 days (top) and 21 days (bottom).
Cerebral haemorrhage may be divided into hyperacute (<24h), acute (1-3 days), subacute (3-14 days), chronic (>2 weeks) and ancient (years). T1 and T2 signal changes occur over this time as haemoglobin becomes deoxyhaemoglobin, intracellular methaemoglobin, extracellular methaemoglobin, and finally iron-containing breakdown products such as haemosiderin.
The first image is essentially T2 isointense to brain and corresponds to the mid subacute stage. The high signal rim is due to oedema. The haematoma is probably isointense because it contains a mixture of intracellular methaemoglobin (hypointense) and extracellular methaemoglobin (hyperintense). The second image corresponds to the chronic stage, with central hyperintensity and a rim of hypointensity. These correspond to extracellular methaemoglobin (hyperintense) and haemosiderin (hypointense).
Reference: ACR Learning File: Neuroradiology
Credit: Dr Laughlin Dawes
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