Convex array vector velocity imaging using transverse oscillation and its optimization
Research output: Contribution to journal › Journal article › Research › peer-review
A method for obtaining vector flow images using the transverse oscillation (TO) approach on a convex array is presented. The paper presents optimization schemes for TO fields and evaluates their performance using simulations and measurements with an experimental scanner. A 3-MHz 192-element convex array probe (pitch 0.33 mm) is used in both simulations and measurements. A parabolic velocity profile is simulated at a beam-to-flow angle of 90°. The optimization routine changes the lateral oscillation period λ as a function of depth to yield the best possible estimates based on the energy ratio between positive and negative spatial frequencies in the ultrasound field. The energy ratio is reduced from -17.1 dB to -22.1 dB. Parabolic profiles are estimated on simulated data using 16 emissions. The optimization gives a reduction in standard deviation from 8.81% to 7.4% for 16 emissions, with a reduction in lateral velocity bias from -15.93% to 0.78% at 90° (transverse flow) at a depth of 40 mm. Measurements have been performed using the experimental ultrasound scanner and a convex array transducer. A bias of -0.93% was obtained at 87° for a parabolic velocity profile along with a standard deviation of 6.37%. The livers of two healthy volunteers were scanned using the experimental setup. The in vivo images demonstrate that the method yields realistic estimates with a consistent angle and mean velocity across three heart cycles.
Original language | English |
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Article number | 734897 |
Journal | IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control |
Volume | 62 |
Issue number | 12 |
Pages (from-to) | 2043-2053 |
Number of pages | 11 |
ISSN | 0885-3010 |
DOIs | |
Publication status | Published - Dec 2015 |
Bibliographical note
Publisher Copyright:
© 1986-2012 IEEE.
- Arrays, Focusing, Frequency measurement, Optimization, Oscillators, Transducers
Research areas
ID: 331500311