Ahead of Print article · Journal article
3-D Vector Flow Estimation With Row–Column-Addressed Arrays
Department of Electrical Engineering, Technical University of Denmark1
Biomedical Engineering, Department of Electrical Engineering, Technical University of Denmark2
Department of Micro- and Nanotechnology, Technical University of Denmark3
BK Medical ApS4
MEMS-AppliedSensors, Department of Micro- and Nanotechnology, Technical University of Denmark5
Simulation and experimental results from 3-D vector flow estimations for a 62 + 62 2-D row–column (RC) array with integrated apodization are presented. A method for implementing a 3-D transverse oscillation (TO) velocity estimator on a 3-MHz RC array is developed and validated. First, a parametric simulation study is conducted, where flow direction, ensemble length, number of pulse cycles, steering angles, transmit/receive apodization, and TO apodization profiles and spacing are varied, to find the optimal parameter configuration.
The performance of the estimator is evaluated with respect to relative mean bias B˜ and mean standard deviation σ˜ . Second, the optimal parameter configuration is implemented on the prototype RC probe connected to the experimental ultrasound scanner SARUS. Results from measurements conducted in a flow-rig system containing a constant laminar flow and a straight-vessel phantom with a pulsating flow are presented.
Both an M-mode and a steered transmit sequence are applied. The 3-D vector flow is estimated in the flow rig for four representative flow directions. In the setup with 90° beam-to-flow angle, the relative mean bias across the entire velocity profile is (−4.7, −0.9, 0.4)% with a relative standard deviation of (8.7, 5.1, 0.8)% for (vx , vy, vz).
The estimated peak velocity is 48.5 ± 3 cm/s giving a −3% bias. The out-of-plane velocity component perpendicular to the cross section is used to estimate volumetric flow rates in the flow rig at a 90° beam-to-flow angle. The estimated mean flow rate in this setup is 91.2 ± 3.1 L/h corresponding to a bias of −11.1%.
In a pulsating flow setup, flow rate measured during five cycles is 2.3 ± 0.1 mL/stroke giving a negative 9.7% bias. It is concluded that accurate 3-D vector flow estimation can be obtained using a 2-D RC-addressed array
Language: | English |
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Publisher: | IEEE |
Year: | 2016 |
Pages: | 1799-1814 |
ISSN: | 15258955 and 08853010 |
Types: | Ahead of Print article and Journal article |
DOI: | 10.1109/TUFFC.2016.2582536 |
ORCIDs: | Holbek, Simon , Stuart, Matthias Bo , Thomsen, Erik Vilain and Jensen, Jørgen Arendt |
3-D vector flow imaging Blood flow Medical ultrasound Row-column addressed arrays Transverse oscillation
2D RC-addressed array 3D transverse oscillation velocity estimator 3D vector flow estimation Array signal processing Arrays Blood Computer Simulation Estimation Imaging, Three-Dimensional Oscillators Phantoms, Imaging Probes RC array TO apodization profiles Transducers Ultrasonography biomedical ultrasonics blood flow constant laminar flow flow-rig system integrated apodization medical ultrasound optimal parameter configuration parametric simulation prototype RC probe pulsating flow pulse cycles receive apodization row-column addressed arrays row-column-addressed arrays standard deviation steered transmit sequence steering angles straight-vessel phantom transmit apodization transverse oscillation ultrasound scanner SARUS velocity profile volumetric flow rates