• Ultrasound-guided photoacoustics: from basic science tool to clinically-viable functional and molecular imaging

    Ultrasound-guided photoacoustics (USPA) is a high-resolution, high-sensitivity, depth-resolved, multi-scale imaging technique based on a synergistic combination of what seems to be drastically different energy sources: light and sound. Augmented with targeted imaging contrast nanoagents, this technique is capable of simultaneous visualization of structural, functional, and molecular/cellular properties of tissue. This presentation, via examples, will offer a few insights into how the USPA imaging can change both fundamental medical science and the clinical management of diseases. Several biomedical and clinical applications including microscopic and macroscopic imaging of pathology, cell and particle tracking, cancer detection and diagnosis, and molecular therapy will be presented. The desired characteristics of the devices and design of nanoconstructs with specific physicochemical properties will be discussed. Finally, current challenges and concerns associated with clinical translation of USPA imaging will be presented, and possible solutions will be discussed.

  • Stanislav Emelianov is a Joseph M. Pettit Endowed Chair, Georgia Research Alliance Eminent Scholar, and Professor of Electrical & Computer Engineering and Biomedical Engineering at the Georgia Institute of Technology. He is also appointed at the Emory University School of Medicine, where he is affiliated with Winship Cancer Institute, Department of Radiology, and other clinical units. Furthermore, Dr. Emelianov is Director of the Ultrasound Imaging and Therapeutics Research Laboratory at the Georgia Institute of Technology focused on the translation of diagnostic imaging & therapeutic instrumentation, and nanobiotechnology for clinical applications.

    Throughout his career, Dr. Emelianov has been devoted to the development of advanced imaging methods capable of detecting and diagnosing cancer and other pathologies, assisting treatment planning, and enhancing image-guided therapy and monitoring of the treatment outcome. He is specifically interested in intelligent biomedical imaging and sensing ranging from molecular imaging to small animal imaging to clinical applications. Furthermore, Dr. Emelianov develops approaches for image-guided molecular therapy and therapeutic applications of ultrasound and electromagnetic energy. Finally, nanobiotechnology plays a critical role in his research. In the course of his work, Dr. Emelianov has pioneered several ultrasound-based imaging techniques, including shear wave elasticity imaging and molecular photoacoustic imaging. Overall, projects in Dr. Emelianov’s laboratory, which focuses on cancer and other diseases, range from molecular imaging to functional imaging and tissue differentiation, from drug delivery and release to image-guided surgery and intervention.

  • Stanislav Emelianov is a Joseph M. Pettit Endowed Chair, Georgia Research Alliance Eminent Scholar, and Professor of Electrical & Computer Engineering and Biomedical Engineering at the Georgia Institute of Technology. He is also appointed at the Emory University School of Medicine, where he is affiliated with Winship Cancer Institute, Department of Radiology, and other clinical units. Furthermore, Dr. Emelianov is Director of the Ultrasound Imaging and Therapeutics Research Laboratory at the Georgia Institute of Technology focused on the translation of diagnostic imaging & therapeutic instrumentation, and nanobiotechnology for clinical applications.

    Throughout his career, Dr. Emelianov has been devoted to the development of advanced imaging methods capable of detecting and diagnosing cancer and other pathologies, assisting treatment planning, and enhancing image-guided therapy and monitoring of the treatment outcome. He is specifically interested in intelligent biomedical imaging and sensing ranging from molecular imaging to small animal imaging to clinical applications. Furthermore, Dr. Emelianov develops approaches for image-guided molecular therapy and therapeutic applications of ultrasound and electromagnetic energy. Finally, nanobiotechnology plays a critical role in his research. In the course of his work, Dr. Emelianov has pioneered several ultrasound-based imaging techniques, including shear wave elasticity imaging and molecular photoacoustic imaging. Overall, projects in Dr. Emelianov’s laboratory, which focuses on cancer and other diseases, range from molecular imaging to functional imaging and tissue differentiation, from drug delivery and release to image-guided surgery and intervention.

  • Compressed Sensing in Photoacoustic Tomography

    Increasing the imaging speed is a central aim in photoacoustic (PA) tomography. This issue is especially important in the case of sequential scanning approaches as applied for most existing optical detection schemes. In this talk we address this issue using techniques of compressed sensing. We demonstrate, that the number of measurements can significantly be reduced by allowing general linear measurements instead of point-wise pressure values. A main requirement in compressed sensing is the sparsity of the unknowns to be recovered. For that purpose, we develop the concept of sparsifying temporal transforms for PA tomography.  To efficiently exploit the induced sparsity, we develop a two-stage reconstruction framework as well as a direct algorithm that jointly recovers the initial and the modified sparse source. Reconstruction results with simulated as well as experimental data are given.

  • Markus Haltmeier received his Ph.D. degree in mathematics from the University of Innsbruck, Tyrol, Austria, in 2007, for research on computed tomography. He was then involved in various aspects of inverse problems as a research scientist with the University of Innsbruck, the University of Vienna, Austria, and the Max Planck Institute for Biophysical Chemistry, Göttingen, Germany. Since 2012, he is full professor with the Department of Mathematics, University of Innsbruck. His current research interests include inverse problems, signal and image processing, computerized tomography, and machine learning.

  • Markus Haltmeier received his Ph.D. degree in mathematics from the University of Innsbruck, Tyrol, Austria, in 2007, for research on computed tomography. He was then involved in various aspects of inverse problems as a research scientist with the University of Innsbruck, the University of Vienna, Austria, and the Max Planck Institute for Biophysical Chemistry, Göttingen, Germany. Since 2012, he is full professor with the Department of Mathematics, University of Innsbruck. His current research interests include inverse problems, signal and image processing, computerized tomography, and machine learning.

  • Quantitative GHz ultrasonic imaging of biological cells and transparent structures

    Picosecond ultrasonics has been recently applied to characterize single cells after decades of being used to investigate the mechanical properties of metals and semiconductors on sub-micron scales. This technique monitors GHz Brillouin oscillations in the time domain, allowing acoustic properties—sound velocity and ultrasonic attenuation—for the nucleus and vacuole of animal or vegetal cells to be measured. In addition, cell density, compressibility and adhesion, as well as mechanical properties of cell walls have been studied.

    In the talk we present the experiments on the 3D imaging of mammalian cell properties using picosecond ultrasonics with sub-micron spatial resolution.[1] A 830-nm pump beam consisting of a train of ultrashort optical pulses is focused at normal incidence to a ~1 micron spot on the film from the substrate side, heating the Ti film from underneath. A picosecond ultrasonic pulse then traverses the cells. These ultrasonic pulses are monitored by a 415-nm probe beam, focused to a ~0.5 micron spot size to the same point and controlled by a delay line that provides temporal scanning. By this method we obtain three-dimensional images with ~0.5 micron lateral resolution.

    We also introduce a new technique that can provide quantitative imaging of both the sound velocity and refractive index independently. This work should lead to a new means for non-invasive investigations of internal cellular structure as well as being applicable to the evaluation of inorganic transparent structures.

    [1] S. Danworaphong, et al., Appl. Phys. Lett. 106, 163701-1-4 (2015)

  • Oliver B. Wright

    Education

    • B. A. Physics, University College, Oxford
    • Ph. D. Physics, Cavendish Laboratory, Cambridge

    Professional Experience

    • Laboratory for Very Low Temperature Physics, CNRS, Grenoble, France
      Royal Society Fellowship
    • Schlumberger Montrouge Research, France
      Researcher (Ingénieur) in Optical Sensors Group
    • Nippon Steel Corp., Electronics Research Laboratories, Sagamihara, Japan
      Senior Researcher
    • CNR, Istituto di Acustica “O. M. Corbino”, Rome, Italy
      EU Human Capital and Mobility Senior Fellowship
    •  Laboratory of the Physics and Metrology of Oscillators, CNRS, Besancon, France
      Researcher (Ingénieur de recherche)
    • Dept. of Applied Physics, Faculty of Engineering, Hokkaido University, Japan
      Professor (tenured post)

    General Research Interests

    Picosecond ultrasonics and plasmonics in nanostructures, acoustic metamaterials, surface acoustic wave visualization with ultrashort optical pulses, ultrafast electronic and thermal diffusion, nanoscale phonon detection using atomic force microscopy

    Society Membership

    • Institute of Physics, U.K., Fellow
    • Optical Society of America
    • American Institute of Physics
    • Physical Society of Japan
  • Oliver B. Wright initially specialized in low temperature solid state physics. After obtaining an industrial post he concentrated on optical sensors, specializing in the use of ultrashort optical pulses for generating and detecting picosecond acoustic phonon pulses in solids, developing a detection technique based on the measurement of picosecond surface motion. He thereby demonstrated how ultrafast electron diffusion could be probed in metals. He has also worked on the development of ultrasonic force microscopy and local-probe thermal imaging techniques.

    Focusing also on semiconductors, he measured the shape of picosecond acoustic phonon pulses generated in gallium arsenide, and was involved in similar experiments on semiconductor quantum wells. In parallel, he helped establish a method for watching ripples on crystals as well as making contributions to the theory of the detection of phonon pulses in multilayers.

    He was also involved in extending picosecond ultrasonics to shear waves, to liquids, and to contact mechanics, as well as spending time watching ripples travelling on phononic crystals, resonators, and on electromagnetic and acoustic metamaterials. More recently he has worked on gigahertz vibrations of nanostructures and metamaterials, including plasmonic crystals, and is currently also active in the field of acoustic metamaterials from audio to GHz frequencies.