MRI demonstrating hyperintensity in T2 and FLAIR sequences is the gold standard for making the diagnosis. It may not be visible on CT. [5]
Neither the pattern nor severity of vasogenic oedema are related to the severity of clinical symptoms.
Oedema tends to occur in a bilateral pattern within the posterior white matter, at the watershed areas [3, 5]. The oedema can be described in the following distributions:
Parieto-occipital (~50%)
Superior frontal sulcus pattern (~25%)
Holohemispheric watershed pattern (~25%)
Central pattern (~10%)
Additional common findings: infarct, parenchymal microhaemorrhages, sub-arachnoid haemorrhages. [1]
