The Comparative Analysis of Isotope Clearance Curves in Normal and Ischemic Brain

The regional cerebral blood flow has been measured by intracarotid 133Xenon in ten normal subjects, ten with miscellaneous cerebral ischemic lesions, eight with transient ischemic attacks and seven with completed strokes. The data have been examined by the stochastic and two-compartmental methods of analysis and by reference to the slope of the initial two minutes of the clearance curves. In normal unanesthetized normocapnic subjects the correlation between the results obtained by each of these methods is high. In ischemic lesions the correlation is less god. All three methods, however, are liable to miss, or to misrepresent the significance of, disturbances which can be demonstrated when the proportion and rate of perfusion of gray and white matter are separately estimated.