Ordering diffusion-weighted MRI measurements improves results from partially completed scans
Cook P, Alexander D, Boulby P, Symms M
University College London
Diffusion-MRI often uses a spherical sampling scheme, which acquires images sequentially with diffusion weighting gradients in unique directions distributed isotropically on the hemisphere. If not all of the measurements can be completed, the quality of results from the partial scan is sensitive to the order of the gradient directions in the scanner protocol. A partial scan may cover parts of the hemisphere densely but other parts sparsely and thus provide poor spherical coverage. We present a method to optimise maximise the spherical coverage of partial scans without affecting the spherical sampling of the complete acquisition.