Hemispheric mean transit time of a non-diffusible radioactive tracer in acute stroke

The cerebral mode transit time of hippuran 131I was measured in 30 patients suffering from hemispheric ischemic stroke. The average mode transit time of each hemisphere was calculated from the curve obtained by an arbitrary and by an averaging statistical smoothing. The statistical analysis of the results was based on the comparison of the right-left hemisphere difference of mode transit time between the control and stroke patients. The average mode transit time in patients and controls obtained by statistical averaging showed slightly different values in the stroke patients as compared to those obtained by the arbitrary visual smoothing of the curve. However, the right-left hemisphere differences were the same whether arbitrary smoothing or statistical averaging were used. This study confirms previous observations that the circulation time is significantly prolonged in the involved hemisphere in patients with acute ischemic stroke.