Partial Volume Effect and Correction for 3D Color Flow Acquisition of Volumetric Blood Flow

• Published in: IEEE transactions on ultrasonics, ferroelectrics, and frequency control ferroelectrics, and frequency control, 2019-08, Vol.66 (11), p.1749-1759
• Main Authors: Kripfgans, Oliver D., Rubin, Jonathan M., Pinter, Stephen Z., Jago, James, Leichner, Ron, Fowlkes, J. Brian
• Format: Article
• Language: English
• ISSN: 0885-3010; 1525-8955
• DOI: 10.1109/TUFFC.2019.2934119

Blood volume flow estimation is becoming an integral part of quantitative medical imaging. Three-dimensional color flow can be used to measure volumetric flow, but partial volume correction is essential due to finite beam widths and lumen diameters. Color flow power was previously assumed to be directly proportional to the perfused fractional color flow beam area (voxel). We investigate the relationship between color flow power and fractionally-perfused voxels. We simulate three-dimensional color flow imaging using Field II based on a 3.75-MHz mechanically-swept linear array. A 16-mm diameter tube with laminar flow was embedded into soft tissue. We investigated two study scenarios: (1) where soft tissue backscatter is 40 dB higher and (2) 40 dB lower relative to blood. Velocity and power were computed from color flow packets (n=16) using autocorrelation. Study 1 employed a convolution-based wall filter. Study 2 did not employ a wall filter. Volume flow was computed from the resulting color flow data as published previously. Partial volume voxels in Study 1 show less power than those in Study 2, likely due to wall filter effects. An ‘S’-shaped relationship was found between color flow power and fractionally-perfused voxel area in Study 2, which could be due to an asymmetric lateral-elevational point spread function. Flow computation is biased low by 7.3% and 7.9% in Study 1 and Study 2, respectively. Uncorrected simulation estimates are biased high by 41.5% and 12.5% in Study 1 and Study 2, respectively. Our findings show that partial volume correction improves three-dimensional volume flow estimation and that wall filter processing alters the proportionality between color flow power and fractionally-perfused voxel area.