Is positron emission tomography useful in stroke?

Positron emission tomography (PET) has been widely used in the study of stroke and related cerebrovascular diseases. It has shown the various stages leading to cerebral infarction and defined the significance of the ischaemic penumbra. PET scan can predict the clinical outcome of patients with acute ischaemic stroke. Several types of diaschisis can also be demonstrated by PET. They reflect different pathophysiological changes in supratentorial infarcts. Post-apoplectic seizures are shown to increase the ischaemic damage in the affected cerebral hemisphere. PET has contributed also to the concept of multi-infarct dementia, although the significance of chronic ischaemia in the pathogenesis of vascular dementia has not been fully investigated.