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- Publications
- Influence
A fundamental limit on delay estimation using partially correlated speckle signals
Delay estimation is used in ultrasonic imaging to estimate blood or soft tissue motion, to measure echo arrival time differences for phase aberration correction, and to estimate displacement for… Expand
A spline-based algorithm for continuous time-delay estimation using sampled data
- F. Viola, W. Walker
- Computer Science, Medicine
- IEEE Transactions on Ultrasonics, Ferroelectrics…
- 28 February 2005
TLDR
A constrained adaptive beamformer for medical ultrasound: initial results
TLDR
A comparison of the performance of time-delay estimators in medical ultrasound
Time-delay estimation (TDE) is a common operation in ultrasound signal processing. In applications such as blood flow estimation, elastography, phase aberration correction, and many more, the quality… Expand
The application of k-space in pulse echo ultrasound
TLDR
A fundamental limit on the performance of correlation based phase correction and flow estimation techniques
Cross correlation and similar operations are used in ultrasonic imaging to estimate blood or soft tissue motion in one or more dimensions and to measure echo arrival time differences for phase… Expand
Radiation force imaging of viscoelastic properties with reduced artifacts
- F. Viola, W. Walker
- Materials Science, Medicine
- IEEE Transactions on Ultrasonics, Ferroelectrics…
- 9 July 2003
It is well-known that changes in the mechanical properties of tissues are correlated with the presence of disease. In the eye, for example, the vitreous body undergoes dramatic changes in mechanical… Expand
Adaptive signal processing in medical ultrasound beamforming
For over thirty years adaptive beamforming (AB) algorithms have been applied in RADAR and SONAR signal processing. Higher resolution and contrast is attainable using those algorithms at the price of… Expand
A speckle target adaptive imaging technique in the presence of distributed aberrations
- G.C. Ng, P. Freiburger, W. Walker, G. Trahey
- Physics, Medicine
- IEEE Transactions on Ultrasonics, Ferroelectrics…
- 1997
Acoustic velocity inhomogeneities in tissue result in aberration of ultrasound images. These aberrations can be modeled as a near field thin phase screen or as a distributed aberrator. The effect of… Expand
Cystic resolution: A performance metric for ultrasound imaging systems
- K. Ranganathan, W. Walker
- Engineering, Medicine
- IEEE Transactions on Ultrasonics, Ferroelectrics…
- 16 April 2007
This paper describes a metric that can be used to characterize the resolution of arbitrary broadband coherent imaging systems. The metric is particularly suited to medical ultrasound because it… Expand