SPECT in cerebrovascular disorders

Abstract

Stroke represents a major public health problem with an incidence of 100–300 per 100000 of the population a year. In the USA there are 3 million stroke survivors and 500000 new first strokes per annum. Stroke accounts for 10% of all deaths in Western countries, age-adjusted mortality in the USA being 50–100 per 100000 of the population. Ischaemic stroke is four times more common than haemorrhagic stroke, accounting for 70–80% of all cases. Intracranial haemorrhage accounts for 20-30%, of which one-third to one-half are the consequence of subarachnoid haemorrhage. Stroke risk is determined by age, ethnic origin, genetic predisposition and modifiable risk factors such as hypertension, associated cardiac disease and cigarette smoking. Mortality varies from 8–20% in the first 30 days in ischaemic stroke, depending on specific stroke subtype. The annual recurrence rate for first ever stroke varies between 6 and 9%. Ischaemic cerebrovascular disease is therefore a common disorder, presenting not at specialist centres but to local community practitioners and district hospitals. It is important that potential investigative techniques are available to the majority of sufferers: SPECT systems capable of producing images of sufficient quality to be useful in the context of cerebrovascular disease are now available even in relatively small centres.