Q-space trajectory imaging for multidimensional diffusion MRI of the human brain

Carl-Fredrik Westin, Hans Knutsson, Ofer Pasternak, Filip Szczepankiewicz, Evren Özarslan, Danielle van Westen, Cecilia Mattisson, Mats Bogren, Lauren J. O'Donnell, Marek Kubicki, Daniel Topgaard, Markus Nilsson

Abstract: Highlights•We have described a new diffusion MR framework for imaging of microstructure that we call q-space trajectory imaging.•Performing diffusion encoding with a wide range of q-space trajectories is feasible on a clinical system.•The cumulant expansion of the MR signal yields the mean diffusion tensor and a fourth-order covariance tensor.•QTI can disentangle variation in size from variation in shape and direction.•QTI does not require macroscopic anisotropy and could be useful not only in white matter but also in gray matter.