Nathan S. White1, Trygve B. Leergaard2, Alex de Crespigny3,4, Anders M. Dale5
1Cognitive Science, University of California, San Diego, La Jolla, CA, USA; 2Centre for Molecular Biology and Neuroscience, University of Oslo, Norway; 3Radiology and Neurosciences, Massachusetts General Hospital, Harvard University; 4Department of Clinical Neurology, Oxford University, UK; 5Neurosciences and Radiology, University of California, San Diego, La Jolla, CA, USA
We present a new model-based analysis method for diffusion MRI called Restriction Spectrum Imaging (RSI). Traditional model-based deconvolution methods assume all fibers in a given voxel are composed of the same biological components and thus have identical water restriction properties. In RSI, the tissue is modeled using a spectrum of both oriented and non-oriented diffusion components with different water restriction scales. Both the volume fraction and 3D orientation of each individual component can be derived in each voxel using linear estimation methods. RSI may provide a more complete characterization of tissue with complex neuromorphologies.