Volume flow measurements with a novel semi-automated 4D Doppler ultrasound scanner [blood flow measurement]

The Encore PV is a novel, real time 3D (i.e., 4D) ultrasound scanner capable of measuring blood flow. In vitro and in vivo volume flow measurements obtained from the Encore were compared to those from an invasive transit time flowmeter. A flow pump was used to simulate carotid type waveforms with pulsatile flow rates from 60 to 600 ml/min. Encore volume flows were compared to an invasive technique for volumetric blood flow measurement utilizing a transit time flowmeter. In vivo 10 s data sets of the volume flow in the distal aorta of 6 rabbits were obtained simultaneously with the Encore PV and the flowmeter. Mean and maximum volume flows were recorded with both units. Data was compared using linear regression and Bland-Altman analysis. It was found that volume flow measurements with this unit are comparable to those of an invasive flowmeter.