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.