My area of research is medical imaging physics and its applications. During my Ph.D. at Sunnybrook Health Sciences Centre, I studied the fractal properties of vascular structures and models of organ blood flow using computed tomography. In that time, I became more and more interested in human cognition and the brain. Consequently, after completing my Ph.D. research, I joined the Rotman Research Institute as a postdoctoral fellow in December 2006 to work on the advancement of brain imaging techniques.

Two research projects are currently in progress:

1. Functional Magnetic Resonance Imaging (fMRI) and Magnetoencephalography (MEG) of Brain Activity

Both fMRI and MEG provide measures of brain activity. However, fMRI signals are related to changes in local blood flow while MEG records changes in the magnetic field around the head related to changes in neuronal currents in the brain. In addition, a feature of fMRI is high spatial resolution with poor time resolution while MEG, in comparison, has lower spatial resolution and higher temporal resolution. Combining these two techniques offers therefore a more complete picture of brain activity than either technique by itself.

In the current project, we are using both of these techniques to measure the response of the brain to vibrational stimuli on a finger. The stimuli cause a neuronal response in the brain, associated with changes in the MEG signal, which then causes an increase in blood flow and a subsequent change in the fMRI signal. Based on our knowledge of both fMRI and MEG signals we are trying to improve our current understanding of this chain of events. This will improve our ability to detect changes in normal brain function, for example due to stroke. In stroke patients, the sense of touch is often impaired. Such patients will therefore be part of this study to investigate how the response of the brain to a vibrational stimulus has changed. This, in turn, may provide clues for future therapies.

2. Evaluation of Parallel Magnetic Resonance (MR) Imaging based on Quantitative Brain Morphometry

In recent years, a new technique in MR imaging called Parallel Imaging has created the potential to acquire images much faster than previously possible. However, this is also associated with a loss of image quality. In this study, we are comparing different levels of acceleration based on commonly performed measures of brain morphology, for example measures of local brain volume. If the change in these measures is minor, then acceleration is recommended. However, major changes would discourage acceleration.

Acceleration is possible for a number of sequences that are commonly employed clinically. The reduction in scan time benefits the comfort of patients and reduces the cost for their examination.