Transverse Oscillation Approach for Estimation of Three-Dimensional Velocity Tensors
Part I: Concept and Simulation Study Michael Johannes Pihl, Member, IEEE, and Jørgen Arendt Jensen, Fellow, IEEE
The presented method decouples the velocity estimation into three orthogonal velocity components using a 2-D transducer.
Field II is used to investigate the method. Several metrics are employed to estimate its performance demonstrating the importance of optimizing the beamforming to reduce bias and standard deviation of the velocity estimates.
This study demonstrates that the velocity estimation can be decoupled and performed simultaneously.
A simulation study using a 32x32 transducer shows an average velocity at the center of a blood vessel of (vx; vy; vz) = (1.00, 0.0091, 0.00058) (0.059, 0.083, 0.0053) m/s compared to the expected velocity of (1, 0, 0) m/s.
Simulating flow in seven directions in the XY-plane spanning from 0 to 90 yields estimated flow angles with a mean bias of -0.14, and with 95% of the estimates within 8.4 of their correct direction. The relative standard deviations increase to 12-14% when adding noise corresponding to a signal-to-noise ratio of 0 dB. Using a heterodyning demodulation approach instead of the TO approach, the relative standard deviations range from 31% to 34% demonstrating that the TO method is less susceptible to noise.
Besides requiring a 2-D transducer, the complexity and the number of calculations of the 3-D Transverse Oscillation method is within the capabilities of modern scanners.
CFU papers presented at SPIE, 2013 in Florida
Preliminary study of synthetic aperture tissue harmonic imaging on in-vivo data
In this paper, a method for synthetic aperture tissue harmonic imaging is investigated. It combines synthetic aperture sequential beamforming (SASB) with tissue harmonic imaging (THI) to produce an increased and more uniform spatial resolution and improved side lobe reduction compared to conventional B-mode imaging.
CFU papers presented at IEEE, 2012 Dresden and
Measuring 3D Velocity Vectors using the Transverse Oscillation Method
The paper presents experimentally obtained estimates of threedimensional (3D) velocity vectors using the 3D Transverse Oscillation (TO) method.
Comparison of 3D Synthetic Aperture Imaging and Explososcan using Phantom Measurements
In this paper, initial 3D ultrasound measurements from a 1024 channel system are presented. Measurements of 3D Synthetic aperture imaging (SAI) and Explososcan are presented and compared.
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