The study of regional cerebral blood flow in stroke patients using technetium 99m HMPAO

Seventeen patients who had suffered a stroke in the previous 72 h have been studied using technetium 99m hexamethyl propylene amine oxime (HMPAO) to assess cerebral blood flow. Comparison of the scan appearances and clinical signs were made in all cases. Twelve of the patients had a repeat HMPAO scan 14 days later, together with further clinical assessment. Good correlation between the size and site of perfusion deficit and the clinical signs was found in 14 of the patients. When the results of the 12 patients who had repeat scans were examined at 14 days the correlation between the scan and the clinical signs was less accurate and it seems unlikely that the assessment of the size of cerebral infarction as demonstrated by an HMPAO scan will provide an accurate prognostic sign. Three of the patients, all of whom had suffered right hemiplegia and were dysphasic, had regions of increased uptake adjacent to the area of ischaemia and non deteriorated clinically; it is thought that this sign may represent hyperperfusion around infarction and indicates a fair prognosis. In patients suffering from transient neurological symptoms, the use of HMPAO may be useful by excluding the presence of other cerebral disease.