Dr. Stuart Foster
Professor & Associate Chair
Department of Medical Biophysics,
University of Toronto, Sunnybrook & Women's College Health Sciences Centre

Monday, May 14, 2007, 6:00 p.m.
    6:00 p.m. Registration
    6:30 p.m. Session begins

Over the past few years biomedical applications of ultrasound have rapidly advanced. This is particularly evident in the development of high frequency micro-imaging of the mouse. The principles of this technology will be described and applications in the areas of cardiovascular and cancer research will be outlined. The development of functional imaging based on the spontaneous contrast of blood at high frequencies and on ultrahigh frame-rate retrospective imaging will be reviewed. The recent introduction of high frequency contrast agents has further expanded the potential for micro-ultrasound to perform functional and targeted imaging in disease models and interventional studies. In this presentation, the current state of the art in high frequency contrast for functional and molecular imaging of the mouse will be examined. Examples of functional imaging of inflammation, cardiovascular disease, and tumour microcirculation will be used to illustrate the potential and limitations of the current implementations. Potential for molecular imaging will be explored in a melanoma xenograft model in which the expression pattern of VEGFR-2 is studied. The current signal processing approaches for high frequency contrast imaging rely on simple linear subtraction schemes. Performance improvements will require optimization of the microbubbles themselves, a better understanding of microbubble interactions at high frequencies in both the bound and unbound state, and improved capabilities in nonlinear excitation and signal processing. These challenges will be discussed and the future of high frequency contrast imaging will be examined.

Dr. Foster is a Senior Scientist with Sunnybrook & Women's College Health Sciences Centre as well as professor and Associate Chairman of Medical Biophysics at the University of Toronto. He was the recipient of a Terry Fox Cancer Research Scientist Award from the National Cancer Institute of Canada and has twice won the Ultrasound in Medicine and Biology Prize. Dr. Foster has been a Distinguished lecturer of the IEEE Ultrasonics Ferroelectrics and Frequency Control Society (1995-6).

Dr. Foster was awarded the Eadie Medal by the Royal Society of Canada in 1977 for major contributions to applied science in Canada. He pioneered the development of the technology and clinical applications of high frequency ultrasound biomicroscopy in the eye. There are now more that 250 commercial systems based on our design around the world. More than 200,000 patients have been scanned with this instrumentation. He developed ultrasound biomicroscopy for imaging of the skin leading to a number of clinical papers on its use to visualize melanoma, basal cell carcinoma and psoriasis. He also performed the first application of high frequency ultrasound to the visualization of the mouse embryo. This work showed the ability of ultrasound biomicroscopy to non-invasively detect and image genetic mutations that affect neural and cardiac mouse development. Dr. Foster reported the first clinical use of high frequency (40 MHz) intravascular ultrasound in human coronary arteries. He was instrumental is establishing the benefits of high frequency intravascular ultrasound and in developing the high frequency transducer technology now used in commercial products. .