Lara Bartels1,2, Jonathan Doucette1,2, Christoph Birkl2,3,4, Yuting Zhang5,6,7,8, Alexander Mark Weber2,9, and Alexander Rauscher1,2,9,10
1Department of Physics & Astronomy, University of British Columbia, Vancouver, BC, Canada, 2UBC MRI Research Centre, University of British Columbia, Vancouver, BC, Canada, 3Department of Neuroradiology, Medical University of Innsbruck, Innsbruck, Austria, 4Department of Neurology, Medical University of Graz, Graz, Austria, 5Department of Radiology, Children's Hospital of Chongqing Medical University, Chongqing, China, 6Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Medical University, Chongqing, China, 7Key Laboratory of Pediatrics in Chongqing, Chongqing Medical University, Chongqing, China, 8Chongqing International Science and Technology Cooperation Center for Child Development and Disorders, Chongqing, China, 9Division of Neurology, Department of Pediatrics, University of British Columbia, Vancouver, BC, Canada, 10Department of Radiology, University of British Columbia, Vancouver, BC, Canada
1Department of Physics & Astronomy, University of British Columbia, Vancouver, BC, Canada, 2UBC MRI Research Centre, University of British Columbia, Vancouver, BC, Canada, 3Department of Neuroradiology, Medical University of Innsbruck, Innsbruck, Austria, 4Department of Neurology, Medical University of Graz, Graz, Austria, 5Department of Radiology, Children's Hospital of Chongqing Medical University, Chongqing, China, 6Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing Medical University, Chongqing, China, 7Key Laboratory of Pediatrics in Chongqing, Chongqing Medical University, Chongqing, China, 8Chongqing International Science and Technology Cooperation Center for Child Development and Disorders, Chongqing, China, 9Division of Neurology, Department of Pediatrics, University of British Columbia, Vancouver, BC, Canada, 10Department of Radiology, University of British Columbia, Vancouver, BC, Canada
We show that the tissue orientation dependency of $$$R_2$$$ relaxation in the unmyelinated newborn brain is best described by dipole-dipole interactions. In the absence of myelin, this finding suggests the alignment of water with neurofilaments or microtubuli.
Geometric mean $$$R_2$$$ as a function of fiber angle in newborns and best fits for the dipole-dipole model, the Knight model and the diffusion model.
Predictions for the $$$R_2$$$ orientation dependence for the dipole-dipole model, the Knight model and the diffusion model.
