The comparison between the cerebral blood flow directly measures and cerebral blood flow velocity in the middle and basilar cerebral arteries measured by transcranial Doppler ultrasonography

Transcranial Doppler ultrasonography (TCD) may be useful for determining al terations in cerebral blood flow (CBF) during excessive hemodynamic changes by non-invasive measurement of the CBF velocity. The purpose of this study was to measure the correlation between CBF and the middle cerebral artery (MCA) and basilar artery (BA) flow velocities, as measured by TCD during ex cessive hemodynamic changes produced by hypertension and hypotension in adu lt dogs. The peak, diastolic, and mean flow velocities were measured by TCD . Arterial hypertension was induced by administration of dopamine at 5 and 15 mu/kg/min, and hypotension was induced by hemorrhage. During the hemodyn amic changes, the BA velocity correlated more closely with the alteration i n the CBF than the MCA velocity. In terms of percentages of the values duri ng anesthesia, there was good correlation between CBF and the MCA and BA ve locities. In conclusion, our findings indicate that MCA and BA velocity mea surements, as a percentage of the values during anesthesia, both give an eq ually accurate indication of alterations in CBF during excessive hemodynami c changes.