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Despite the progress of focused ultrasound (FUS)-mediated blood-brain barrier (BBB) disruption, neuro-inflammatory responses and the high variability of the FUS transmission through the human skull make the control of the acoustic parameters challenging. In this study, we developed a high-field (7-T) magnetic resonance (MR)-guided FUS system with a feedback control based on passive cavitation detection...
The ability to generate changes in the interstitial components of various tissues has a host of potential clinical applications. These include enhancing the delivery of drugs and genes, increasing oxygenation and blood flow for radiosensitization, altering fluid and pressure dynamics in the setting of inflammation, and increasing the clearance of detrimental factors such as amyloid plaques in the...
Biomedical focused ultrasound (US) could represent a new modality of neurostimulation overcoming the limitations of current techniques in terms of invasiveness and spatial resolution. While it has already been proven that low energy US can stimulate nervous activity at the systemic level, little is known regarding the biophysical mechanisms underlying this phenomenon. In this in vivo study, we intended...
The last 20 years have seen the development of fetal surgery, particularly for the treatment of twin-to-twin transfusion syndrome (TTTS). Although fetoscopy increases survival rate, it is also invasive and responsible for fetal and maternal complications affecting the neonatal outcome. A completely non-invasive treatment that could occlude deep anastomoses would prevent the risks of invasive fetoscopy...
Volumetric dynamic contrast-enhanced ultrasound (DCE-US) can be used to yield 3D parametric maps to assess spatial changes in tumor perfusion heterogeneity during cancer treatment. Here, quantitative image features (texture and histogram-based features) extracted from 3D parametric maps were evaluated as surrogates of treatment response, and compared to conventional perfusion parameters.
Tumor hypoxia has been shown to decrease the sensitivity of solid tumors to radiation. Systemic efforts to increase tumor oxygenation levels immediately prior to therapy, however, have largely proven unsuccessful. The objective of this work was to determine the utility of oxygen-filled, ultrasound sensitive microbubbles for locally delivering oxygen and sensitizing tissue to radiation in a breast...
Recent studies have proven that ultrasound as a non-invasive method enable to delivery energy to deep brain for both excitation and reversible suppression of neuronal activity in cell, animal, human experiments (Scientific Reports 6:24170, 2016; Neuron 66(5):681-694; Nature Neuroscience 17(2):322-9, 2014). Due to bulk ultrasound transducer, it is difficult to compatible the ultrasound stimulation...
Magnetomotive ultrasound (MM US) imaging is a method whereby superparamagnetic iron oxide nanoparticles (SPIO NP) are used as a contrast agent. By applying an external magnetic field the particles are set in motion together with their surroundings. The induced movement is detected with ultrasound, and for the case of harmonic excitation of the magnetic source, quadrature detection (lock-in plus phase...
Attenuation in the skeletal muscle microvascular response to insulin plays a critical role in type 2 diabetes and obesity-induced insulin resistance. The goal of the project detailed in this paper was to evaluate the use of super-resolution ultrasound (SR-US) imaging for performing a quantitative analysis of insulin-mediated microvascular changes in skeletal muscle. An Acuson Sequoia 512 ultrasound...
The oscillation of microbubbles has long been hypothesized to provide the opportunity to enhance gene delivery as a result of changes in membrane permeability; however, translationally-relevant therapeutic protocols have not yet been realized. We sought to develop and validate a protocol to transfect endogenous mesenchymal stem cells (MSCs) via the local injection of plasmids and microbubbles and...
The last 20 years have seen the development of fetal surgery, particularly for the treatment of twin-to-twin transfusion syndrome (TTTS). Although fetoscopy increases survival rate, it is also invasive and responsible for fetal and maternal complications affecting the neonatal outcome. A completely non-invasive treatment that could occlude deep anastomoses would prevent the risks of invasive fetoscopy...
Several works carried out these last years have demonstrated the ability of ultrasound (US) to activate neurons at a systemic level. However, no complete description of the biophysical mechanisms involved in this phenomenon has been validated so far. In order to identify experimentally these mechanisms, we here present an in vivo study of the stimulating effects of US exposures on the ventral nerve...
Noninvasive focused ultrasound (FUS) combined with microbubbles has been proven capable of locally and reversibly increasing the blood-brain barrier (BBB) permeability allowing the extravasation of several clinical relevant substances (Hynynen et al. 2001). Despite its progress, neuro-inflammatory responses (Kovacs et al. 2016) and the high variability of the FUS transmission in the brain due to skull...
The current standard for evaluating breast tumor response to neoadjuvant treatment remains the assessment of a tumor size change several weeks after therapy begins. However, the tumor microenvironment (including microvasculature) is known to change drastically before any detectable change in physical size manifests. To that end, we have developed a new high-resolution ultrasound (US) imaging modality...
In cancer treatment, there is a need to improve chemotherapeutic drug uptake at the local tumor site to both enhance dose efficacy and minimize any toxic side effects. It is well known now that stably cavitating microbubbles (MBs) in an ultrasound (US) field can increase the permeability of tumor blood vessel walls. This consequently can enhance the extravasation and accumulation of a circulating...
Epilepsy is the third most commonly diagnosed neurological disorder. For drug-resistant patients, epilepsy surgery is the only option. The outcome of epilepsy surgery largely depends on an accurate mapping of epileptogenic zone. In clinic, this is done with subdural electrode array to monitor the Electrocorticography (ECoG) with a disappointing low spatial resolution of ∼ 1cm. As a result, the cure...
Current clinical standards in the endoscopic diagnosis of gastrointestinal diseases are primarily based on the use of optical systems. Ultrasound has established diagnostic credibility in the form of endoscopic ultrasound (EUS), however it is limited to examination of the upper gastrointestinal tract (oesophagus, stomach and upper (proximal) small bowel). Access to the remainder of the small bowel...
H-scan is a new ultrasound (US) technique that images the relative size of acoustic scatterers. This modality relies on matching a model of pulse-echo formation to the mathematics of a class of Gaussian-weighted Hermite polynomials (GH). Parallel convolution filters using the second (GH2) and eighth (GH8) components are applied to the radio frequency (RF) US data to capture the low and high frequency...
Drug delivery to subcortical regions is susceptible to the blood–brain barrier (BBB) impeding the molecular exchange between the blood stream and the brain parenchyma. Focused ultrasound (FUS) coupled with the administration of microbubbles has been proved to open the BBB locally, transiently, and noninvasively both in rodents and in nonhuman-primates (NHPs). The development of this disruption technique...
This paper describes an in-vivo pilot study in which the systolic myocardial stiffness of four pigs was measured with various acoustic techniques. We compare the propagation velocity of shear waves in open chest and closed chest experiments, in which the open-chest shear wave was either physiologically induced by aortic valve closure (N=3), or externally induced by acoustic-radiation force (N=1)....
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