Assessment of image-based registration of diffusion-weighted images acquired at high b-value
Muoz Maniega S, Bastin M, Armitage P
University of Edinburgh
One disadvantage of high b-value diffusion MRI techniques is the reduction in signal-to-noise ratio (SNR) of the diffusion-weighted (DW) images due to the large signal attenuation at high b-value. This is thought to cause problems when DW images need to be corrected for eddy-current induced distortions and bulk patient motion using image-based registration techniques. Here we demonstrate that one multimodal registration algorithm, FLIRT (www.fmrib.ox.ac.uk), can register DW images with SNR as low as 1.5 within error tolerance. The possibility of using registration techniques at such low SNR facilitates the quantitative pixel-by-pixel analysis in diffusion imaging techniques using very high b-values.