Bedside functional monitoring of the dynamic brain connectivity in human neonates.

Clinicians have long been interested in functional brain monitoring, as reversible functional losses often precedes observable irreversible structural insults. By characterizing neonatal functional cerebral networks, resting-state functional connectivity is envisioned to provide early markers of cognitive impairments. Here we present a pioneering bedside deep brain resting-state functional connectivity imaging at 250-μm resolution on human neonates using functional ultrasound.

Non-invasive recanalization of deep venous thrombosis by high frequency ultrasound in a swine model with follow-up.

Aims: Pulsed cavitational ultrasound therapy (thombotripsy) allows the accurate fractionation of a distant thrombus. We aimed to evaluate the efficacy and safety of non-invasive thrombotripsy using a robotic assisted and high frequency ultrasound approach to recanalize proximal deep venous thrombosis (DVT) in a swine model.

Methods: Occlusive thrombosis was obtained with a dual jugular and femoral endoveinous approach.

Computationally Efficient Transcranial Ultrasonic Focusing: Taking Advantage of the High Correlation Length of the Human Skull.

The phase correction necessary for transcranial ultrasound therapy requires numerical simulation to noninvasively assess the phase shift induced by the skull bone. Ideally, the numerical simulations need to be fast enough for clinical implementation in a brain therapy protocol and to provide accurate estimation of the phase shift to optimize the refocusing through the skull. In this article, we experimentally performed transcranial ultrasound focusing at 900 kHz on N = 5 human skulls.

Steering Capabilities of an Acoustic Lens for Transcranial Therapy: Numerical and Experimental Studies.

For successful brain therapy, transcranial focused ultrasound must compensate for the time shifts induced locally by the skull. The patient-specific phase profile is currently generated by multi-element arrays which, over time, have tended toward increasing element count. We recently introduced a new approach, consisting of a single-element transducer coupled to an acoustic lens of controlled thickness.

Inside/outside the brain binary cavitation localization based on the lowpass filter effect of the skull on the harmonic content: a proof of concept study.

Cavitation activity induced by ultrasound may occur during high intensity focused ultrasound (HIFU) treatment, due to bubble nucleation under high peak negative pressure, and during blood-brain-barrier (BBB) disruption, due to injected ultrasound contrast agents (UCAs). Such microbubble activity has to be monitored to assess the safety and efficiency of ultrasonic brain treatments. In this study, we aim at assessing whether cavitation occurs within cerebral tissue by binary discriminating cavitation activity originating from the inside or the outside of the skull.

3D-printed adaptive acoustic lens as a disruptive technology for transcranial ultrasound therapy using single-element transducers.

The development of multi-element arrays for better control of the shape of ultrasonic beams has opened the way for focusing through highly aberrating media, such as the human skull. As a result, the use of brain therapy with transcranial-focused ultrasound has rapidly grown. Although effective, such technology is expensive.