Conventions and nomenclature for double diffusion encoding NMR and MRI |
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| Authors: | Noam Shemesh Sune N. Jespersen Daniel C. Alexander Yoram Cohen Ivana Drobnjak Tim B. Dyrby Jurgen Finsterbusch Martin A. Koch Tristan Kuder Fredrik Laun Marco Lawrenz Henrik Lundell Partha P. Mitra Markus Nilsson Evren Özarslan Daniel Topgaard Carl‐Fredrik Westin |
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| Affiliation: | 1. Champalimaud Neuroscience Programme, Champalimaud Centre for the Unknown, Lisbon, Portugal;2. CFIN/MindLab, Aarhus University, Aarhus, Denmark;3. Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark;4. Centre for Medical Image Computing, Department of Computer Science, University College London, London, United Kingdom;5. School of Chemistry, the Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv, Israel;6. Sagol School of Neurosciences, Tel Aviv University, Tel Aviv, Israel;7. Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark;8. Department of Systems Neuroscience, University Medical Center Hamburg‐Eppendorf, Hamburg, Germany;9. Neuroimage Nord, University Medical Centers Hamburg–Kiel–Lübeck, Germany;10. Institute of Medical Engineering, University of Lübeck, Lübeck, Germany;11. Medical Physics in Radiology, German Cancer Research Center, Heidelberg, Germany;12. Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, USA;13. Lund University Bioimaging Center, Lund University, Lund, Sweden;14. Department of Physics, Bo?azi?i University, Bebek, Istanbul, Turkey;15. Division of Physical Chemistry, Department of Chemistry, Lund University, Lund, Sweden;16. Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA |
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| Abstract: | Stejskal and Tanner's ingenious pulsed field gradient design from 1965 has made diffusion NMR and MRI the mainstay of most studies seeking to resolve microstructural information in porous systems in general and biological systems in particular. Methods extending beyond Stejskal and Tanner's design, such as double diffusion encoding (DDE) NMR and MRI, may provide novel quantifiable metrics that are less easily inferred from conventional diffusion acquisitions. Despite the growing interest on the topic, the terminology for the pulse sequences, their parameters, and the metrics that can be derived from them remains inconsistent and disparate among groups active in DDE. Here, we present a consensus of those groups on terminology for DDE sequences and associated concepts. Furthermore, the regimes in which DDE metrics appear to provide microstructural information that cannot be achieved using more conventional counterparts (in a model‐free fashion) are elucidated. We highlight in particular DDE's potential for determining microscopic diffusion anisotropy and microscopic fractional anisotropy, which offer metrics of microscopic features independent of orientation dispersion and thus provide information complementary to the standard, macroscopic, fractional anisotropy conventionally obtained by diffusion MR. Finally, we discuss future vistas and perspectives for DDE. Magn Reson Med 75:82–87, 2016. © 2015 Wiley Periodicals, Inc. |
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| Keywords: | double diffusion encoding double wave vector double pfg microstructure diffusion diffusion mri |
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