• Volumetric Flow Rate Measurement

    Background Direct measurement of volumetric flow in blood vessels has always been a big challenge in the clinical practice and research although knowing the flow volume is beneficial to a range of clinical applications. Most ultrasound techniques which used a 1D array transducer must assume an analytical or symmetrical velocity profile, based on which the…

  • Vascular Flow Imaging

    Background In recent years, echo particle image velocimetry (ePIV), also known as ultrasound particle image Velocimetry (uPIV), has shown to be able to map flow velocity distribution in vivo. The technique provides valuable information about blood flow and flow induced stress on vessel wall for studying cardiovascular diseases. Using sequential ultrasound B-mode (or contrast specific)…

  • Cardiac Imaging and Image Analysis

    Ultrasound and microbubble contrast agents offer imaging and quantifying microcirculation / perfusion within the myocardium. Perfusion defects are an early indicator of coronary heart diseases as opposed to the current clinical practice which still relies on detection of cardiac wall motion abnormalities. We are interested in developing novel imaging (e.g. high frame rate imaging) and…

  • Ultrafast Contrast Image Acquisition

    The recent advancement in digital parallel processing technology has paved the path for very high frame-rate ultrasound imaging based on holographic concepts. Such methods remove the need of line by line scanning, allowing for the reconstruction of an entire ultrasound image from a single transmission. One of the major implications of such methods is the…

  • Bubble Physics

    Microbubbles have shown great promise as ultrasound contrast agents and have been used in a range of clinical applications including cardiovascular diseases and cancer. They are extremely sensitive as contrast agents – under the right ultrasound frequency a single micron-sized bubble can be detected, as they can resonant under ultrasound and oscillate in a highly…

  • Cancer and Molecular Imaging

    The development of microbubble contrast agents for ultrasound (US) imaging has made visualisation and quantification of blood flow in micro-vasculature possible. Such imaging technique can be applied to the diagnosis and treatment of a wide range of clinical conditions such as cardiovascular diseases and cancer. Recently adapting the microbubbles to target specific molecules within the…

  • Brain Imaging

    Ultrasound imaging of the brain is very challenging for traditional reconstruction algorithms. This is for two reasons. First, the strong reflected signal from the skull swamps the weak reflected signal from the brain. Second, algorithms for traditional ultrasound reconstruction cannot account for multiple-scattering in the skull. Instead full-waveform inversion (FWI) has been proposed to reconstruct…

  • Super Resolution

    The spatial resolution of any imaging modality based on waves (Electro-magnetic or mechanical) is fundamentally limited by the size of its wave length (diffraction-limited image resolution). Recently such diffraction limit has been broken in the field of optical microscopy, by the so-called “super-resolved fluorescence microscopy” which was awarded the 2014 Novel Prize in Chemistry. We…