We develop quantitative imaging methods to characterize the tumor microenvironment, and to subsequently relate these imaging parameters to biomarkers that can be used for cancer surveillance, diagnosis and treatment monitoring/characterization. The focus is on 1) developing new acquisition methods and protocols to enhance quantification, 2) designing new image processing algorithms, analysis parameters and statistical models to quantitatively characterize imaging data, and 3) using advanced AI methods to further refine quantification or classification. While our methods can be used for other imaging modalities, we primarily focus on Ultrasound imaging modes such as contrast, molecular, elastography and spectroscopic ultrasound. Disease focus include liver cancer and liver metastasis, liver fibrosis/cirrhosis, and tumor blood flow characterization.

Academic Appointments

  • Instructor, Radiology

Professional Education

  • PhD, University of Toronto/Sunnybrook Research Institute, Medical Biophysics - Imaging Physics and Radiation Oncology (2014)
  • MSc, Ryerson University, Physics (2008)
  • BEng, Ryerson University, Electrical and Computer Engineering (2005)


All Publications

  • Ultrasound Elastography: Review of Techniques and Clinical Applications THERANOSTICS Sigrist, R. M., Liau, J., El Kaffas, A., Chammas, M. C., Willmann, J. K. 2017; 7 (5): 1303-1329


    Elastography-based imaging techniques have received substantial attention in recent years for non-invasive assessment of tissue mechanical properties. These techniques take advantage of changed soft tissue elasticity in various pathologies to yield qualitative and quantitative information that can be used for diagnostic purposes. Measurements are acquired in specialized imaging modes that can detect tissue stiffness in response to an applied mechanical force (compression or shear wave). Ultrasound-based methods are of particular interest due to its many inherent advantages, such as wide availability including at the bedside and relatively low cost. Several ultrasound elastography techniques using different excitation methods have been developed. In general, these can be classified into strain imaging methods that use internal or external compression stimuli, and shear wave imaging that use ultrasound-generated traveling shear wave stimuli. While ultrasound elastography has shown promising results for non-invasive assessment of liver fibrosis, new applications in breast, thyroid, prostate, kidney and lymph node imaging are emerging. Here, we review the basic principles, foundation physics, and limitations of ultrasound elastography and summarize its current clinical use and ongoing developments in various clinical applications.

    View details for DOI 10.7150/thno.18650

    View details for Web of Science ID 000396574200021

    View details for PubMedID 28435467