A5077943933- Ultrasound and Hyperthermia Applications
- Photoacoustic and Ultrasonic Imaging
- Ultrasound Imaging and Elastography
- Ultrasound and Cavitation Phenomena
- Advanced MRI Techniques and Applications
- Electrical and Bioimpedance Tomography
- Cardiovascular Health and Disease Prevention
- Flow Measurement and Analysis
- Hemodynamic Monitoring and Therapy
- Optical Imaging and Spectroscopy Techniques
- Muscle activation and electromyography studies
- Cardiac Imaging and Diagnostics
- Coronary Interventions and Diagnostics
- Ultrasonics and Acoustic Wave Propagation
- Cardiovascular Function and Risk Factors
- Cardiovascular and Diving-Related Complications
- Seismic Imaging and Inversion Techniques
- Nanoplatforms for cancer theranostics
- Medical Imaging Techniques and Applications
- Non-Invasive Vital Sign Monitoring
- Microfluidic and Bio-sensing Technologies
- Fluid Dynamics and Mixing
- Cerebrovascular and Carotid Artery Diseases
- Thermography and Photoacoustic Techniques
- Breast Cancer Treatment Studies
Imperial College London
2015-2024
South China University of Technology
2024
The London College
2024
St Mark's Hospital
2024
Royal Brompton Hospital
2024
Lund University
2023
Hebei Medical University
2023
Second Hospital of Hebei Medical University
2023
King's College London
2017-2018
University of Oxford
2005-2006
The structure of microvasculature cannot be resolved using standard clinical ultrasound (US) imaging frequencies due to the fundamental diffraction limit US waves. In this work, we use a system perform in vivo sub-diffraction on CD1, female mouse aged eight weeks by localizing isolated signals from microbubbles flowing within ear microvasculature, and compare our results optical microscopy. Furthermore, develop new technique map blood velocity at super-resolution tracking individual bubbles...
Ultrasound (US) is a widely used clinical imaging modality that offers penetration depths in tissue of >10 cm. However, the spatial resolution US fundamentally limited by diffraction to approximately half wavelength sound wave employed. The optical microscopy same fundamental physics, but recent years super-resolution techniques have been developed overcome limit through localization many spatially separated photo-switchable or photo-activatable fluorophores. In this paper, we apply related...
Magnetic resonance imaging and X-ray computed tomography provide the two principal methods available for brain at high spatial resolution, but these are not easily portable cannot be applied safely to all patients. Ultrasound is universally safe, existing modalities image usefully inside adult human skull. We use in silico simulations demonstrate that full-waveform inversion, a computational technique originally developed geophysics, able generate accurate three-dimensional images of with...
Myocardial microvasculature and haemodynamics are indicative of potential microvascular diseases for patients with symptoms coronary heart disease in the absence obstructive arteries. However, imaging structure flow within myocardium is challenging owing to small size vessels constant movement patient's heart. Here we show feasibility transthoracic ultrasound localization microscopy myocardial explanted pig hearts vivo. Through a customized data-acquisition processing pipeline cardiac...
Encapsulated microbubbles are well established as highly effective contrast agents for ultrasound imaging. There remain, however, some significant challenges to fully realize the potential of in advanced applications such perfusion mapping, targeted drug delivery, and gene therapy. A key requirement is accurate characterization viscoelastic surface properties microbubbles, but methods independent, nondestructive quantification mapping these currently lacking. We present here a strategy...
The structure of microvasculature cannot be resolved using conventional ultrasound (US) imaging due to the fundamental diffraction limit at clinical US frequencies. It is possible overcome this resolution limitation by localizing individual microbubbles through multiple frames and forming a superresolved image, which usually requires seconds minutes acquisition. Over time interval, motion inevitable tissue movement typically combination large- small-scale translation deformation. Therefore,...
Ultrasound imaging is the most widely used method for visualising and quantifying blood flow in medical practice, but existing techniques have various limitations terms of sensitivity, field view, angle dependence, depth. In this study, we developed an ultrasound velocimetry approach capable dynamic flow, by combining high-frame-rate plane wave imaging, microbubble contrast agents, pulse inversion speckle image tracking algorithms. The system was initially evaluated vitro on both straight...
Background Variations in lymph node (LN) microcirculation can be indicative of metastasis. The identification and quantification metastatic LNs remains essential for prognosis treatment planning, but a reliable noninvasive imaging technique is lacking. Three-dimensional super-resolution (SR) US has shown potential to noninvasively visualize microvascular networks vivo. Purpose To study the feasibility three-dimensional SR rabbit LN structure blood flow by using microbubbles. Materials...
High-frame-rate 3-D ultrasound imaging technology combined with super-resolution processing method can visualize microvascular structures by overcoming the diffraction-limited resolution in every spatial direction. However, using a full 2-D array requires system large number of independent channels, design which might be impractical due to high cost, complexity, and volume data produced. In this study, sparse was designed fabricated 512 elements chosen from density-tapered spiral layout....
Ultrasound super-resolution imaging through localisation and tracking of microbubbles can achieve sub-wave-diffraction resolution in mapping both micro-vascular structure flow dynamics deep tissue <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">in vivo</i> . Currently, it is still challenging to high accuracy particularly with limited frame rates the presence bubble concentrations. This study introduces microbubble image features into a...
With the widespread interest and uptake of super-resolution ultrasound (SRUS) through localization tracking microbubbles, also known as microscopy (ULM), many algorithms have been developed. ULM can image centimeters into tissue in-vivo track microvascular flow non-invasively with sub-diffraction resolution. In a significant community effort, we organized challenge, Ultrasound Localization TRacking Algorithms for Super-Resolution (ULTRA-SR). The aims this paper are threefold: to describe...
Acoustic super-resolution imaging has allowed the visualization of microvascular structure and flow beyond diffraction limit using standard clinical ultrasound systems through localization many spatially isolated microbubble signals. The determination each position is typically performed by calculating centroid, finding a local maximum, or peak 2-D Gaussian function fit to signal. However, backscattered signal from depends not only on characteristics waveform, but also behavior in acoustic...
Localization-based ultrasound super-resolution imaging using microbubble contrast agents and phase-change nano-droplets has been developed to visualize microvascular structures beyond the diffraction limit. However, long data acquisition time makes clinical translation more challenging. In this study, fast acoustic wave sparsely activated localization microscopy (fast-AWSALM) was achieve super-resolved frames with sub-second temporal resolution, by low-boiling-point octafluoropropane...
Microbubble contrast agents produce nonlinear echoes under ultrasound insonation, and current imaging techniques detect these to generate agent images accordingly. For techniques, there is a potential problem in that bubbles along the transmission path between transducer target can alter nonlinearly contribute echoes. This lead artefacts, especially regions at depth. In this paper we provide insight, through both simulation experimental measurement, into propagation caused by microbubbles...
The high efficiency with which gas microbubbles can scatter ultrasound compared the surrounding blood pool or tissues has led to their widespread employment as contrast agents in imaging. In recent years, applications have been extended include super-resolution imaging and stimulation of localized bio-effects for therapy. growing exploitation particular these developments amplified need characterize fully understand microbubble behavior. aim doing so is more exploit utility both diagnostic...
Objective Variations of conductive fluid content in brain tissue (e.g. cerebral edema) change impedance and can potentially be measured by Electrical Impedance Tomography (EIT), an emerging medical imaging technique. The objective this work is to establish the feasibility using EIT as tool for monitoring content. Design a prospective study. Setting In study was used, first time, monitor variations clinical model with patients undergoing dehydration treatment. system developed house its...
Standard clinical ultrasound (US) imaging frequencies are unable to resolve microvascular structures due the fundamental diffraction limit of US waves. Recent demonstrations 2-D super-resolution both in vitro and vivo have demonstrated that fine vascular can be visualized using acoustic single bubble localization. Visualization more complex disordered 3-D vasculature, such as a tumor, requires an acquisition strategy which additionally localize bubbles elevational plane with high precision...
We demonstrate a versatile phase-change sub-micron contrast agent providing three modes of enhancement: 1) photoacoustic imaging contrast, 2) ultrasound with optical activation, and 3) acoustic activation. This agent, which we name 'Cy-droplet', has the following novel features. It comprises highly volatile perfluorocarbon for easy near-infrared optically absorbing dye chosen to absorb light at wavelength good tissue penetration. is manufactured via 'microbubble condensation' method. The...