Axon radius estimation with Oscillating Gradient Spin Echo (OGSE) diffusion MRI

The estimation of axon radius provides insights into brain function [1] and could provide progression and classification biomarkers for a number of white matter diseases [2-4]. A recent in silico study [5] has shown that optimised gradient waveforms (GEN) and oscillating gradient waveform spin echo...

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Bibliographic Details
Main Authors: Siow, Bernard, Drobnjak, Ivana, Ianus, Andrada, Christie, Isabel N., Lythgoe, Mark F., Alexander, Daniel C.
Other Authors: University College London, Centre for Medical Image Computing
Format: Article
Language:English
Published: Universitätsbibliothek Leipzig 2015
Subjects:
Online Access:http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-184163
http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-184163
http://www.qucosa.de/fileadmin/data/qucosa/documents/18416/diff_fund_18%282013%291.pdf
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Summary:The estimation of axon radius provides insights into brain function [1] and could provide progression and classification biomarkers for a number of white matter diseases [2-4]. A recent in silico study [5] has shown that optimised gradient waveforms (GEN) and oscillating gradient waveform spin echo (OGSE) have increased sensitivity to small axon radius compared to pulsed gradient spin echo (PGSE) diffusion MR sequences. In a follow-up study [6], experiments with glass capillaries show the practical feasibility of GEN sequences and verify improved pore-size estimates. Here, we compare PGSE with sine, sine with arbitrary phase, and square wave OGSE (SNOGSE, SPOGSE, SWOGSE, respectively) for axon radius mapping in the corpus callosum of a rat, ex-vivo. Our results suggest improvements in pore size estimates from OGSE over PGSE, with greatest improvement from SWOGSE, supporting theoretical results from [5] and other studies [7-9].