Long-term Doppler ultrasound measurement through the anterior fontanel in neonates: choice of parameter for computer...

There is no easy comparison of the Doppler spectra. Therefore, determining parameters is necessary for long-term measurements. A manual analysis is laborious, limits the number of possible examinations, and considerations are restricted to the envelope curve (maximal cerebral blood flow velocity). The applied ultrasonic apparatus (a modified HP 77020AC) determines three waveforms besides the Doppler spectrum: V max as maximal, V means as average, and V mode as the most frequently measured velocity. These data are directly transferred to a PC. Using low Doppler intensity V max resulted in values up to 39% lower than determined by manual analysis because of the apparatus' algorithm. By use of higher Doppler intensity this difference was reduced to 19%. Regarding clinical validity, the V s mean seemed to be the best parameter for further processing. Determining peak systolic velocity (V mean), end-diastolic velocity (V d mean), and mean velocity over time (V mean) were selected for standard analysis. The Pourcelot index was not taken into account, first for lack of definition for V mean and secondly for not missing simultaneous changes of the peak systolic and the end-diastolic velocity.