Middle Cerebral Artery Blood Velocity and Cerebral Blood Flow in Sickle Cell Disease

To understand better the relationship between blood velocity measured by transcranial Doppler and cerebral blood flow measured by the luXe inhalation method, we examined 23 patients undergoing evaluation in the Comprehensive Sickle Cell Center at Columbia University. Blood velocity in the middle cerebral artery was directly related to cerebral flow (r=0.77; p< 0.05). A multivariate analysis in this sample made it possible to improve this correlation to account for more than 90 % of the variability in cerebral blood flow by the use of transcranial Doppler measures of velocity and pulsatility along with the patient's age and hematocrit (r=0.95; p<0.001). It is likely that the combination of Doppler and clinical or demographic variables in other diseases will similarly improve the quantitative estimation of cerebral blood flow. (Stroke 1991^2:27-30) In 1982, the transcranial Doppler (TCD) ultra-sound device was introduced which, by using alower frequency probe, was able to record blood velocity from the basal cerebral arteries through an intact cranium.1 The TCD device is becoming accepted as a useful tool for the evaluation of intracranial stenosis, vasospasm, and the intracra