Cancer imaging using perfusion and diffusion information
Cancer tumours steal their energy and oxygen supply from the patient, often quickly stimulating the creation of a network of blood vessels to feed their needs. MRI-based methods to measure the blood supply, or perfusion, of tumours are of great interest. We develop mathematical models that enable accurate measurements. We are also interested in techniques that can provide fast and simple assessment of variations in perfusion between tumour regions.
(Zaki Ahmed, Thomas Rosin, Ives Levesque)
The microscopic structure of cancer tumours is different from healthy tissue, and this can be detected and characterized by diffusion MRI. This family of techniques is sensitive to the random motion of water molecules in the body, which in turn can inform us about the structure of tissue at the cellular level. Our research is focused on the physical interpretation of diffusion MRI measurements. We are also interested in knowing why tumours can have different regions with different diffusion MRI properties.
(Stella Xing, Ives Levesque)
Mapping magnetic susceptibility in tissues
The phase of the MRI signal can be used to produce maps of the magnetic susceptibility in the body. The magnetic susceptibility is simply a measure of how a material responds to magnetic field. This produces images that are sensitive to the presence of iron, blood vessels, and variations in the microscopic structure of brain tissue. We use these techniques to study the brain and cancer tumours. Our main focus is on making the measurements as stable and accurate as possible, using new mathematical approaches.
(Veronique Fortier, Ives Levesque)
Myelin mapping in the brain with T2* relaxation
Myelin plays a key role in brain function by helping neurons communication more efficiently. We can use MRI-based techniques to measure myelin content in 3D, to study healthy and diseased brain.
(Eva Alonso Ortiz, Ives Levesque, Bruce Pike)
Magnetization transfer (MT) MRI of musculoskeletal tissues
We study cartilage and meniscus, important structures in the knee joint, using magnetization transfer MRI techniques. These are affected by conditions such as osteoarthritis. Our work could reveal the breakdown and changes in the composition of meniscus and cartilage in early stages of the disease, and help evaluate treatments.
(Mikaël Simard, Ives Levesque, with Emily McWalter and Garry Gold)