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

The aim was to validate intracerebral laser Doppler measurements: a technique with potential applications for studying cerebral microcirculation. A technique for measurements of blood flow from the internal carotid artery was developed 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 cerebral cortex was 0.29 (P<0.005). The correlation improved using relative changes from baseline (coefficient of correlation=0.62, P<0.0001). The highest coefficient of correlation (0.85, P<0.0001) was obtained when blood flow in the right internal carotid artery and laser Doppler flow signal from the corresponding right hemisphere were compared. Laser Doppler flowmetry from intracerebral probes correlates with the internal carotid artery blood flow. Laser Doppler flowmetry from intracerebral probes may provide a simple method for continuous local blood flow measurement in the brain. Copyright 1999 Harcourt Publishers Ltd.