Volumetric blood flow estimation using dynamic three-dimensional ultrasound color flow imaging

Quantitative Color Flow Imaging (CFI) was applied to cardiac blood volume flow estimation using three-dimensional (3D) ultrasound imaging. The probe, with a 2.5 MHz phased array transducer, was tilted while continuously registering its spatial position. The 2D scanplanes were reorganized according to its position in the cardiac cycle producing the dynamic 3D volume data. The data was acquired with high framerate (50-100 frames/sec). This temporal resolution was maintained for the 3D volumetric data. The data scan conversion, interpolation and spatial averaging operations were performed separately on the raw digital 3D tissue and Doppler data. By selecting a plane perpendicular to the ultrasonic beams, the velocity vector components normal to the plane were used to compute the blood volume flow throughout the cardiac cycle. The results show blood flow estimates calculated both from the left ventricle outflow and inflow. Care has been taken to correctly interpolate aliased velocity vectors with low velocity moving tissue. The authors conclude that by using raw digital 3D ultrasound tissue and color flow data with high framerate, it was possible to produce detailed cardiac blood volume flow curves