Diffusion MRI at ultra-high fields
Diffusion MRI (DWI or DTI) enables to assess diffusion properties of tissue, and is particularly interesting to infer properties of white matter fibre structure of the human brain. It is an important marker for tissue viability and enables the tracking of white matter fibres in vivo. At field strengths of 1.5T and 3T the spatial resolution is limited due to the available signal per voxel. At 7T the higher available signal will help to improve the spatial resolution, and that the stronger gradient set enables a higher sensitivity for diffusion properties.
The aims of this study are to develop a method that enables high spatial resolution in a reasonable scan time. This is achieved by combining readout-segmented acquisition (RESOLVE) and simultaneous multi-slice excitation using PINS pulses to reduce RF power. We also investigate optimum parameters for the number of diffusion direction gradients and number of b-values to achieve a good estimation of microstructure parameters using tissue models.
This project is in collaboration with Profs Karla Miller and Peter Koopmans (Oxford University, UK)