Meeting Banner
Abstract #1893

Optimising Time-Varying Gradient Orientation for Microstructure Sensitivity in Diffusion-Weighted MR

Ivana Drobnjak1, Daniel C. Alexander1

1Center for Medical Image Computing, Department of Computer Science, University College London, London, United Kingdom

We explore whether variable, rather than fixed, orientation of diffusion-gradients improves sensitivity to coherently oriented pore size. We optimise the shape and orientation of the gradient waveform to minimise the expected variance of parameter estimates of a simple white-matter model. Results suggest that: varying orientation in a plane perpendicular to the cylinders does not increase sensitivity to model parameters; variation in a parallel plane increases sensitivity significantly because it improves the diffusion constant estimates; similar improvement in estimates can be achieved without optimising orientation, but by having one measurement in the parallel and the others in the perpendicular direction.