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Ultrasound low-velocity flow estimations using cross-correlation and decorrelation: a thread phantom study.

Pan TT, Chiang HK

Institute of Biomedical Engineering, National Yang Ming University, 155, 2nd Sec., Li-Nung St., Taipei 112, Taiwan.

In this paper, two time-domain flow velocity measurement methods, cross-correlation and decorrelation, were implemented and compared in measuring low blood-flow velocities, ranging from 0.05 to 5 cm/s, at known beam-vessel angles of 50-90 degrees in a thread phantom. Both methods achieved a significant correlation between the measured and the known velocities (r=0.99; P<0.001) in the thread phantom measurements, at 50-70 degrees beam-vessel angles. Although the cross-correlation method showed a significant correlation (r>0.99; P<0.001), this method caused large errors (>45%) at 80 degrees and 90 degrees , whereas the decorrelation method not only achieved a significant correlation (r>0.99; P<0.001) but also resulted in smaller errors (<19%) at 80 degrees and 90 degrees . This study demonstrates the potential of time-domain decorrelation method for measuring low flow velocity at large beam-vessel angles near perpendicular conditions.

Published 6 March 2007 in Med Eng Phys, 29(5): 602-14.
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