Grant: CIHR New Investigator

Multiple sclerosis (MS) affects more than 60,000 Canadians and more than 1000 Canadians are diagnosed with MS every year. MS is the most important cause of neurologic disability in young adults and can have a significant negative impact for the health of individuals and for society. Every patient with MS undergoes a magnetic resonance imaging (MRI) scan of the brain. Most of the information gathered with MRI is due to subtle variations in signal magnitude which can be translated into images with meaningful information. These images are currently used in MRI of people with MS. The MRI signal, however, has another, promising, yet underexploited property: phase. The phase is best explained by using the analogy of a lighthouse: The MRI signal's magnitude corresponds to the brightness of the lighthouse beam and the MRI signal's phase corresponds to the beam's direction. Just as the lighthouse beam always has a certain direction, the MR signal always has a certain phase. This means that phase information comes for free with almost every MR scan and can be used in addition to the magnitude. Moreover, phase is exquisitely sensitive to changes in tissue occurring due to MS. However, many aspects of MR phase are poorly understood and before we can delve into more sophisticated applications of MR phase imaging, we first need to investigate the sources of phase contrast. Therefore, we propose to investigate the sources of phase contrast in healthy tissue and in brain tissue of people with MS. In MS, phase information could allow us to investigate the brains of patients in high spatial detail and high sensitivity to tissue changes. Our research will improve the early diagnosis of MS and the monitoring of disease progression and treatment and it will help doctors to make the right intervention at the right time.