Regional cerebral blood flow velocity patterns in newborn infants

Using range-gated pulsed Doppler sonography, cerebral blood flow velocity (CBFV) waveforms from the anterior cerebral artery (ACA), middle cerebral artery (MCA) and circle of Willis artery (CW) were examined in a total of 34 newborn infants. We compared the pulsatility index (PI) from the three cerebral arteries sampled in 10 term and 10 preterm (29 +/- 2 weeks) newborn infants without a history of perinatal asphyxia or intracranial pathology. The Pl in the ACA ranged from 0.60 to 1.03. There were no significant differences in Pl between the three vessels by paired comparisons. The Pl of the MCA differed from that of the ACA by 0.00 +/- 0.05. The variation coefficient (CV) was 7%. For CW with ACA, the difference was 0.00 +/- 0.04 and CV was 6%. Both intra- and interexaminer variation in Pl measurements were studied in another 14 infants. The variation coefficients were 5-8% for all three cerebral arteries. We showed that CBFV waveform patterns were similar in regional cerebral arteries, with Pl being a consistent CBFV index. In normal cerebral circulation, the intervessel Pl differences were within observer variations. Deviation from this may suggest abnormal regional cerebral haemodynamics.