Reproducibility of intracranial Doppler flow velocimetry.

Doppler velocimetry for assessment of flow in deep cerebral arteries was investigated in 9 term and 11 preterm healthy infants. A combined range gated and continuous wave Doppler instrument was used. A satisfactory reproducibility was found with a variation coefficient of 8-10% between repeated measurements. No systematic difference between examiners or head positions was recorded. The term infants had significantly higher mean flow velocities, 21.1 (3.1) cm/s (mean and 1 SD), compared to the preterm infants', 15.1 (3.6) cm/s (p less than 0.01). Both systolic and diastolic flow velocities were higher in the term infants, whereas the pulsatility index was higher in the preterm infants. Recordings from the intracranial part of the internal carotid arteries were found to be easy to obtain with a satisfactory reproducibility.