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Speed-of-sound (SoS) is a fundamental acoustic property of tissues that is essential for ultrasound image beamforming. The SoS can also act as a quantitative biomarker for pathology in tissue. Typically, the beamforming SoS is assumed to be 1540 m/s for human imaging, but it may be imprecise for imaging scenarios with inhomogeneous tissue. In this work, we present a novel framework for multilayer […]

Ultrasound localization microscopy (ULM) enables imaging of cerebral vasculature at a microscopic scale with deep penetration. However, conventional 2-D ULM suffers from elevation projection and cannot capture the out-of-plane vessels. Recently developed volumetric ULM overcomes the limitations by providing isotropic resolution and enabling comprehensive visualization of the microvascular […]

Surgical tool tip localization and tracking are essential components of surgical and interventional procedures. The cross sections of tool tips can be considered as acoustic point sources to achieve these tasks with deep learning applied to photoacoustic channel data. However, source localization was previously limited to the lateral and axial dimensions of an ultrasound transducer. In this […]

Speckle statistics estimation is a useful quantitative ultrasound tool for characterizing tissue microstructure. However, because of their elongated geometry, fibrillar tissue components like collagen may not be described well by speckle statistics models. The purpose of this study is to perform a systematic analysis of the effects of microstructural anisotropy on speckle statistics estimation. […]

The shear wave elastography (SWE) provides quantitative markers for tissue characterization by measuring the shear wave speed (SWS), which reflects tissue stiffness. SWE uses an acoustic radiation force pulse sequence to generate shear waves that propagate laterally through tissue with transient displacements. These waves travel perpendicular to the applied force, and their displacements are […]

Sparse arrays offer several advantages over other element reduction techniques for 3-D ultrasound imaging. However, the large interelement spacing in these arrays results in high sidelobe-related artifacts, which significantly degrade image quality and limit their application in 3-D ultrasound imaging. Adaptive beamformers have been proposed to mitigate sidelobe-related artifacts, but they often […]

The transition to minimally invasive spinal surgery over traditional open procedures requires the development of imaging techniques that meet the size constraints. Due to size restrictions associated with minimally invasive spine surgery (MISS), current imaging techniques are largely limited to microscopy, which is only capable of line-of-sight imaging of the tissue surface. A miniature, […]

Boiling histotripsy (BH) is a pulsed high-intensity focused ultrasound (HIFU)-based method of extracorporeal nonthermal tissue disintegration under real-time ultrasound (US) guidance. Respiratory motion in abdominal targets can affect BH precision and completeness. This study compares two motion mitigation strategies based on pulse/echo US motion tracking: robotic arm-based unidirectional motion […]

Directional filtering has been applied to distinguish between the ascending and descending flows in functional ultrasound imaging; however, it can lead to incorrect measurement of the flow speed and direction when using the directional filtering-based improved directional color Doppler ultrasound (iCD_US) velocimetry. Specifically, in cases where the frequency spectrum bandwidth of a […]