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Education

  • BSc Hons, Physics, York University (Canada) 1989
  • MSc, Physics, York University (Canada) 1991
  • PhD, Medical Physics, McMaster University (Canada) 1996

Research Interests

Optics in medicine, biomedical imaging to guide cancer therapy; molecular guided surgery; dose imaging in radiation therapy; Cherenkov light imaging; image guided spectroscopy of cancer; photodynamic therapy; modeling of tumor pathophysiology and contrast

Selected Publications

Professional Activities

  • Dean of Graduate Studies, Dartmouth College 2008-2012
  • Chair, Biomedical Imaging Technology Study Section, National Institutes of Health, 2012-2014
  • Conference Chair, Gordon Research Conference: Lasers in Medicine and Biology, July 2012
  • Conference Chair: Molecular Guided Surgery: Molecules Devices and Applications, SPIE BiOS, San Francisco CA
  • Editorial Boards: Medical Physics; Journal of Biomedical Optics; Journal of Photochemistry and Photobiology B: Biology; Photonics and Lasers in Medicine; Physics in Medicine and Biology

Courses

Patents

  • Apparatus and methods for structured light scatteroscopy | 10,485,425
  • Structured-light imaging systems and methods for determining sub-diffuse scattering parameters | 10,463,256
  • Operative Microscope having diffuse optical imaging system with tomographic image reconstruction and superposition in field of view | 9,254,103

Startups

DoseOptics
President and Co-Founder
QUEL Imaging
President and Co-Founder

Research Projects

  • Near-infrared imaging

    Near-infrared imaging

    Near-infrared imaging (NIR) provides a way to quantify blood and water concentrations in tissue, as well as structural and functional parameters. Since normal tissue, benign tumors, and malignant tumors each carry different concentrations of both hemoglobin and water, and have different levels of oxygen demand and ultrastructural scattering, NIR spectroscopy can be combined into standard imaging systems as an effective method of to provide additional information for breast cancer detection and diagnosis. Work is ongoing to improve techniques for better image reconstruction, display and integration with magnetic resonance imaging (MRI) and computed tomography (CT) imaging.

    See also Near Infrared Optical Imaging Group

  • Optical molecular imaging

    Optical molecular imaging

    Optical molecular imaging is being used to provide molecular guidance in cancer surgery. Fluorescent contrast agents are in pre-clinical and clinical studies to image cancer tumors in vivo, with a dual focus, first on getting more accurate information out of the tissue, and secondly to provide better information about the specificity of the molecules as markers. Systems and algorithms for diffuse fluorescence imaging of tissue are studied, both as a stand-alone system, and as coupled to magnetic resonance imaging and computed tomography imaging. Tracer kinetic modeling is also being developed to allow quantitative imaging of molecular binding in vivo.

  • Fluorescence-guided surgery

    Fluorescence-guided surgery

    Fluorescence-guided surgery is important for the resection of some types of cancerous tumors where the tumor and normal tissue are similar in appearance and texture, and patient prognosis depends heavily on the completeness of resection. By selectively tagging tumor tissue with fluorescent dyes, it becomes possible to visually discriminate between normal and tumor tissues and improve significantly the completeness of tumor resection.

  • Photodynamic therapy

    Photodynamic therapy

    Photodynamic therapy (PDT) is a newly emerging therapy for displastic tissues, such as cancer, age-related blindness, pre-malignant transformation or psoriasis. The therapy involves the administration of a photosensitizing agent, together with the application of moderate intensity light to active the molecules to produce local doses of singlet oxygen. Ongoing research topics include, developing improved dosimetry instrumentation and software, fluorescence tomography imaging to sense drug localization, and assaying unique tumor biology and treatment effects in experimental cancers.

  • Quantitative scatter imaging

    Quantitative scatter imaging

    Quantitative scatter imaging makes use of the fact that normal functioning cells and cancerous cells show differences both in the components within the cells and in the structural organization of the cells within the tissue. These physical distinctions in biological structure have been shown to scatter light differently. This study develops a new approach to imaging scatter-based contrast over a wide field of view in tissue using high frequency structured light. These scattering features may provide a method to diagnostically identify abnormal tissue without the need to administer targeted compounds. This approach has the potential to generate new diagnostic screenings and new approaches for surgical guidance.

  • Cerenkov imaging in radiation therapy

    Cerenkov imaging in radiation therapy

    Radiation therapy is used to treat cancer tumors by killing the tissue with high ionizing radiation doses. Until recently it has not been possible to image the radiation dose delivered to tissue, but through Cherenkov light imaging, this delivered dose can be mapped with high resolution cameras. The research group focuses on quantification of the imaging, and developing tools which allow radiation therapy to be delivered in a safer and more validated manner.

  • Scintillation dosimetry for quality assurance in radiotherapy

    Scintillation dosimetry for quality assurance in radiotherapy

    Radiation therapy is used to treat cancer tumors by killing the tissue with high ionizing radiation doses. Modern external beam radiotherapy systems deliver high dose levels to precisely marked tumor volume in less time. As a mis-administration can have potentially severe impact to the surrounding healthy tissue, more stringent and complex quality assurance measurements are required in clinics. By developing a comprehensive optical dose imaging camera system, we aim to fundamentally simplify the quality assurance process and, in turn, to further promote the culture of safety in radiotherapy. By converting the dose to visible light using scintillation phantom, we can image and reconstruct 3D dose maps in real time, enabling complete and accurate verification in a fast enough timeframe for it to be useful in every procedure.

Videos

Imaging Medicine at Dartmouth

Graduate Student Engineering Research: Čerenkov Fluorescence Imaging

Graduate Student Engineering Research: Optics and Radiation Therapy

Medical lasers: diagnosing disease, treating disease, curing disease

Books

News

All Together Now
Apr 07, 2011
Deep vision
Mar 07, 2011