Medical imaging

Medical imaging exploits the interaction of energy (x-ray, radio-frequency, and acoustic) with the human body to generate images (maps) of internal structures and functions of the human body for clinical purposes such as medical diagnosis and treatments. Solid understanding of the physics behind these interactions is crucial for improving the established imaging modalities.

Image processing is used to enhance certain features of medical images so that medical diagnosis can be improved and enhanced. Furthermore, quantitative analysis of medical images allows one to determine the progression of disease and evaluate effectiveness of treatments.

Optimization of digital mammography

Mammography is the gold standard for detecting breast cancer. X-ray film used to be the choice for mammography until recently. Now that digital imaging detector technology has evolved so that these detectors can handle the extremely high spatial and contrast resolution demands of mammography, digital mammography is becoming a reality. Due to the restrictions of operating optical densities, it was not possible to optimize film mammography based on breast size. However with digital mammography it is possible to optimize image quality for any breast size at the expense of radiation dose. We are working on identifying the optimal technique factors (x-ray spectra, kVp and exposure) for a given breast size to detect a given size of a tumor, with the radiation dose as a constraint.

Breast density analysis

Breast density as determined from mammograms is well known to be associated with high risk of developing breast cancer. We have developed methods to automatically estimate the breast density from digital mammograms. Currently we are working on correlating the mammographic breast density with that obtained from Computed Tomography (CT), Magnetic Resonance Imaging (MRI), and Digital Breast Tomosysnthesis. Furthermore, the various density patterns seen in breast tissue may indicate further information about the risks of developing breast cancer. We are also working on characterization of breast density patterns for the purpose of breast cancer detection and prevention.

This work is carried out in conjunction with the Cancer Centre for the Southern Interior (CSI), based in Kelowna.