Intracerebral laser Doppler blood flow measurements compared to blood flowin porcine internal carotid artery

The aim was to validate intracerebral laser Doppler measurement a technique with potential applications for studying cerebral microcirculation. A tech nique for measurements of blood flow from the internal carotid artery was d eveloped and compared to the laser Doppler method in a pig model. Cerebral blood flow was varied using haemorrhage, high cerebrospinal fluid pressure and blood volume expansion. The coefficient of correlation between flow in the carotid artery and laser Doppler flow signals from probes in the cerebr al cortex was 0.29 (P < 0.005). The correlation improved using relative cha nges from baseline (coefficient of correlation=0.62, P < 0.0001). The highe st coefficient of correlation (0.85, P < 0.0001) was obtained when blood fl ow in the right internal carotid artery and laser Doppler flow signal from the corresponding right hemisphere were compared. Laser Doppler flowmetry f rom intracerebral probes correlates with the internal carotid artery blood flow. Laser Doppler flowmetry from intracerebral probes may provide a simpl e method for continuous local blood flow measurement in the brain. (C) 1999 Harcourt Publishers Ltd.