Ultrasonic methods for assessment of tissue motion in elastography
Department of Biomedical Engineering
This chapter provides an overview of the methods that are used for ultrasound elastography, which utilizes tissue displacements as fundamental information to infer mechanical properties of biological soft tissues. In signal processing, cross‐correlation is a basic concept and has been commonly used for pattern recognition in various applications, including time‐delay estimation in elastography. Constitutive equations of materials based on continuum mechanics describe the macroscopic stress response to external mechanical stimuli. Most contemporary motion‐tracking techniques are based on two important ingredients, a coarse‐to‐fine search scheme and injection of biases, to overcome large tracking errors. To use the motion regularization, speckle tracking can be modeled as an optimization problem using an energy function combining the correlation coefficient with speckle motion continuity. While region‐based methods are commonly used, optical flow estimation can also be done by assuming certain forms of motion smoothness through nonparametric motion models.
Ultrasound Elastography for Biomedical Applications and Medicine
Ultrasonic methods for assessment of tissue motion in elastography.
Ultrasound Elastography for Biomedical Applications and Medicine, 35-70.
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