Diffusion imaging is an MRI method for tracking the physical connections in the brain and investigating the microscopic properties of tissue. Brain tissue alters the natural chaotic movement (diffusion) of water molecules. This process can be detected with MRI to trace information pathways and characterize water trapped in cellular structures.
Current methods have limited spatial resolution, making it difficult to distinguish crossing white matter tracts, intricate fibre patterns and to track fibres through “bottlenecks”. We are developing methods that increase the spatial resolution, with particular focus on FMRIB’s 7T scanner. Other techniques under development reduce image distortion using “navigator” measurements, along with sophisticated image reconstruction techniques.
We are also actively working on diffusion-weighted steady-state free precession (DW-SSFP), which may be able to achieve high spatial and angular resolution diffusion imaging. This method has been particularly successful for imaging post-mortem brains, which have great potential to provide crucial validation of in-vivo measurements, as well as provide unprecedented spatial detail.
This research is conducted as part of the Physics Group at the Wellcome Centre for Integrative Neuroimaging.