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In imaging the neonatal brain, overcoming the diffraction limit of conventional ultrasound is required to achieve images of sufficient spatial resolution. Super-resolution imaging uses ultrasound localization microscopy to image inert microbubble contrast at high frame rates, allowing exquisite detail and flow information on intracranial vessels. While currently more common in research settings, […]

Large field-of-view (FOV) brain imaging with ultrasound has become increasingly achievable with the application of 2-D probes capable of volumetric imaging. However, even in small animals the skull presents a significant barrier and conventional plane-wave transcranial imaging lacks the capability to image in some regions, resulting in incomplete super-resolved vascular reconstructions. Here a […]

In microbubble (MB) cavitation-mediated blood-brain barrier (BBB) opening, prior knowledge of the skull’s sound speed properties is required to correct phase aberration and achieve accurate localization of the cavitation source using transcranial passive acoustic mapping (TPAM). Current approaches predominantly rely on CT scans to generate an empirically sound speed map (SSM) for correction […]

Despite their excellent piezoelectric properties, relaxor-based ferroelectric crystals have not been widely used in medium- to low-frequency ultrasound transducers because of the low sensitivity arising from a low capacitance and the low signal intensity due to a weak coercive field of the piezoelectric materials. In this study, a new type of transducer has been designed and fabricated by […]

Large-aperture 2-D arrays benefit from improved lateral resolution at depth, due to the dependence of beamwidth on the inverse of the aperture width, and improved contrast resolution due to electronic focusing. We have been developing modular large-aperture multirow 1024 (64 azimuth $\times 16$ elevation) element, 2-D arrays based on custom-designed and locally integrated application-specific […]

Diagnostic ultrasound safety indices, such as the mechanical index (MI) and the thermal index (TI), serve as approved risk estimators of bioeffects that can result from an ultrasound stimulus. However, especially in ultrasound-based indirect therapeutic applications, only the MI is reported while the TI is overlooked, possibly due to its complex calculation. To simplify the calculation, we […]

Acoustic lenses have been introduced recently to compensate for the phase distortions induced by the propagation across a human skull for ultrasonic deep-brain stimulation in humans. In this study, we present bifocal lenses that compensate for human skull aberrations and allow simultaneous targeting of multiple structures deep in the brain. We investigated the impact of phase unwrapping in the […]

The development of new imaging paradigms in the field of contrast-enhanced ultrasound (CEUS) is hindered by the difficulty to control complex experimental variables in a laboratory setting, such as vascular geometries, nonlinear ultrasound wave propagation in tissue, or microbubble positions within vessels as a function of time. This development would greatly benefit from the ability to control […]

High-end 4-D ultrasound (US) imaging systems typically use probes based on 2-D arrays containing thousands of transducers. Application specific integrated circuits (ASICs), embedded in the probe, manage the numerous transducers, significantly reducing the number of channels needed for the associated scanner. Unfortunately, the closed architecture of these high-end systems prevents research […]