Noninvasive ultrafast imaging of intrinsic waves such as electromechanical or remotely induced shear in elastography techniques for human cardiac applications remains challenging. In this paper, we propose the heart with adapted sector size by coherently compounding diverging emitted from a standard transthoracic phased-array probe. As plane wave coherent compounding, can be summed to obtain high-quality images entire at high frame rate full field view. To image propagation large SNR, view...

Very high frame rate ultrasound imaging has recently allowed for the extension of applications echography to new fields study such as functional brain, cardiac electrophysiology, and quantitative intrinsic mechanical properties tumors, name a few, non-invasively in real time. In this study, we present first implementation Ultrafast Ultrasound Imaging 3D based on use either diverging or plane waves emanating from sparse virtual array located behind probe. It achieves contrast resolution while...

Non-invasive high-resolution imaging of the cerebral vascular anatomy and function is key for study intracranial aneurysms, stenosis, arteriovenous malformations, stroke, but also neurological pathologies, such as degenerative diseases. Direct visualization microvascular networks in whole brain remains however challenging vivo.In this work, we performed 3D ultrafast ultrasound localization microscopy (ULM) using a 2D matrix array mapped whole-brain microvasculature flow at microscopic...

Ultrafast Doppler imaging was introduced as a technique to quantify blood flow in an entire 2-D field of view, expanding the application ultrasound highly sensitive anatomical and functional mapping vessels. We have recently developed 3-D ultrafast imaging, that can produce thousands volumes per second, based on plane diverging wave emissions, demonstrated its clinical feasibility human subjects vivo. In this study, we show noninvasive power Doppler, pulsed color be used perform vessels...

Over the last ten years, shear wave elastography (SWE) has seen considerable development and is now routinely used in clinics to provide mechanical characterization of tissues improve diagnosis. The most advanced technique relies on use an ultrafast scanner generate image waves real time a 2-D plane at several thousands frames per second. We have recently introduced 3-D ultrasound imaging acquire with matrix probes propagation generated by dedicated radiation pressure transducer single...

Shear wave elastography imaging techniques provide quantitative measurement of soft tissues elastic properties. Tendons, muscles and cerebral are composed fibers, which induce a strong anisotropic effect on the mechanical behavior. Currently, these cannot be accurately represented by existing phantoms. Recently, novel approach for orthotropic hydrogel mimicking has been developed (Millon et al 2006 J. Biomed. Mater. Res. B 305-11). The anisotropy is induced in polyvinyl alcohol (PVA) cryogel...

The assessment of myocardial fiber disarray is major interest for the study progression disease. However, time-resolved imaging structure remains unavailable in clinical practice. In this study, we introduce 3D Backscatter Tensor Imaging (3D-BTI), an entirely novel ultrasound-based technique that can map fibers orientation and its dynamics with a temporal resolution 10 ms during single cardiac cycle, non-invasively vivo entire volumes. 3D-BTI based on ultrafast volumetric ultrasound...

Ultrasound localization microscopy (ULM) based on ultrafast ultrasound imaging of circulating microbubbles (MB) can image microvascular blood flows in vivo up to the micron scale. Takayasu arteritis (TA) has an increased vascularisation thickened arterial wall when active. We aimed perform vasa vasorum ULM carotid and demonstrate that provide markers assess TA activity.Patients with were consecutively included assessment activity by National Institute Health criteria: 5 had active (median...

The assessment of fiber architecture is major interest in the progression myocardial disease. Recent techniques such as magnetic resonance diffusion tensor imaging (MR-DTI) or ultrasound elastic (ETI) can derive directions by measuring anisotropy water tissue elasticity, but these present severe limitations a clinical setting. In this study, we propose new technique, backscatter (BTI), which enables determination skeletal muscles and tissues, spatial coherence ultrasonic speckle. We compare...

In biological tissue, an increase in elasticity is often a marker of abnormalities. Techniques such as quasi-static ultrasound elastography have been developed to assess the strain distribution soft tissues two dimensions using compression. However, abnormalities can exhibit very heterogeneous shapes, three dimensional approach would be necessary accurately measure their volume and remove operator dependency. Acquisition volumes at high rates also critical performing real-time imaging with...

The objectives were to develop a novel three-dimensional technology for imaging naturally occurring shear wave (SW) propagation, demonstrate feasibility on human volunteers and quantify SW velocity in different propagation directions. Imaging of natural SWs generated by valve closures has emerged obtain direct measurement cardiac stiffness. Recently, was assessed two dimensions parasternal long axis view under the assumption direction along septum. However, this approach source localization...

3D Imaging of the human heart at high frame rate is major interest for various clinical applications. Electronic complexity and cost has prevented dissemination ultrafast imaging into clinic. Row column addressed (RCA) transducers provide volumetric by using a low electronic channel count, but current models are ill-suited transthoracic cardiac due to field-of-view limitations. In this study, we proposed mechanically curved RCA with an aperture adapted ( 24×16 mm2). The toroidal surface 96...

Strain evaluation is of major interest in clinical cardiology as it can quantify the cardiac function. Myocardial elastography, a radio-frequency (RF)-based cross-correlation method, has been developed to evaluate local strain distribution heart vivo. However, inhomogeneities such RF ablation lesions or infarction require three-dimensional approach be measured accurately. In addition, acquisitions at high volume rate are essential three dimensions. Conventional focused transmit schemes using...

Abstract Background Myocardial work assessment has emerged as a promising tool for left ventricular (LV) performance evaluation. Existing non-invasive methods assessing it rely on assumptions LV pressure and geometry. Recently, shear wave elastography allowed to quantify changes in myocardial stiffness throughout the cardiac cycle. Based Hooke’s law, becomes theoretically possible calculate stress from strain measurements. The main objective of this study is demonstrate feasibility...

The feasibility of shear wave elastography (SWE) in arteries for cardiovascular risk assessment remains to be investigated as the artery's thin wall and intricate material properties induce complex (SW) propagation phenomena. To better understand SW physics bounded media, we proposed an vitro validated finite element model capable simulating propagation, with full flexibility at level tissue's geometry, properties, acoustic radiation force. This computer was presented a relatively basic...

Supersonic shear wave imaging (SSI) is a noninvasive, ultrasound-based technique to quantify the mechanical properties of bulk tissues by measuring propagation speed waves (SW) induced in tissue with an ultrasound transducer. The has been successfully validated liver and breast (tumor) diagnostics potentially useful for assessment stiffness arteries. However, SW arteries subjected different phenomena affecting measurement accuracy. Therefore, we assessed SSI less complex ex vivo setup, that...

Coronary microvascular obstruction also known as no-reflow phenomenon is a major issue during myocardial infarction that bears important prognostic implications. Alterations of the network remains however challenging to assess there no imaging modality in clinics can image directly coronary vessels. Ultrasound Localization Microscopy (ULM) was recently introduced map flows at high spatial resolution (∼10 μm). In this study, we developed an approach alterations flow ex vivo perfused swine...

Pulse wave imaging (PWI) is a noninvasive technique for tracking the propagation of pulse along arterial wall. The 3-D ultrasound would aid in objectively estimating velocity (PWV) vector. This paper aims to introduce novel PWV estimation method direction, validate it phantoms, and test its feasibility vivo. A silicone vessel phantom consisting stiff soft segment longitudinal axis with plaque were constructed. 2-D array center frequency 2.5 MHz was used. Propagation successfully visualized...

The goal of this study was to demonstrate the feasibility semi-automatic evaluation cardiac Doppler indices in a single heartbeat human hearts by performing 4D ultrafast echocardiography with dedicated sequence simultaneous tissue and blood flow imaging.

Quantitative assessment of myocardial stiffness is crucial to understand and evaluate cardiac biomechanics function. Despite the recent progresses ultrasonic shear wave elastography, quantitative evaluation still remains a challenge because strong elastic anisotropy. In this paper we introduce smart ultrasound approach for non-invasive real-time quantification velocity (SWV) fractional anisotropy (FA) in locally transverse isotropic medium such as myocardium. The relies on simultaneous...

Objective. Early diagnosis and acute knowledge of cerebral disease require to map the microflows whole brain. Recently, ultrasound localization microscopy (ULM) was applied quantify blood in 2D brain adult patients down micron scale. Whole 3D clinical ULM remains challenging due transcranial energy loss which reduces significantly imaging sensitivity.Approach. Large aperture probes with a large surface can increase both field view sensitivity. However, active implies thousands acoustic...

Vascular Ehlers-Danlos syndrome (vEDS) is associated with arterial ruptures due to a mutant gene encoding collagen type III (Col-III). To better understand the role of Col-III, we aimed at evaluating aortic stiffness and dynamic stiffening in vEDS mouse models, either quantitative (col3KO mice) or qualitative Col-III defect (col3KI mice). Abdominal wall pulse wave velocities (PWV) col3KO col3KI mice were compared their respective wild (WT) littermates using 15 MHz ultrafast ultrasonic...

Abstract Mapping blood microflows of the whole brain is crucial for early diagnosis cerebral diseases. Ultrasound localization microscopy (ULM) was recently applied to map and quantify in 2D adult patients down micron scale. Whole 3D clinical ULM remains challenging due transcranial energy loss which significantly reduces imaging sensitivity. Large aperture probes with a large surface can increase both resolution However, active implies thousands acoustic elements, limited translation. In...