Document Detail


From single-pulsed field gradient to double-pulsed field gradient MR: gleaning new microstructural information and developing new forms of contrast in MRI.
MedLine Citation:
PMID:  20690130     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
One of the hallmarks of diffusion NMR and MRI is its ability to utilize restricted diffusion to probe compartments much smaller than the excited volume or the MRI voxel, respectively, and to extract microstructural information from them. Single-pulsed field gradient (s-PFG) MR methodologies have been employed with great success to probe microstructures in various disciplines, ranging from chemistry to neuroscience. However, s-PFG MR also suffers from inherent shortcomings, especially when specimens are characterized by orientation or size distributions: in such cases, the microstructural information available from s-PFG experiments is limited or lost. Double-pulsed field gradient (d-PFG) MR methodology, an extension of s-PFG MR, has attracted attention owing to recent theoretical studies predicting that it can overcome certain inherent limitations of s-PFG MR. In this review, we survey the microstructural features that can be obtained from conventional s-PFG methods in the different q regimes, and highlight its limitations. The experimental aspects of d-PFG methodology are then presented, together with an overview of its theoretical underpinnings and a general framework for relating the MR signal decay and material microstructure, affording new microstructural parameters. We then discuss recent studies that have validated the theory using phantoms in which the ground truth is well known a priori, a crucial step prior to the application of d-PFG methodology in neuronal tissue. The experimental findings are in excellent agreement with the theoretical predictions and reveal, inter alia, zero-crossings of the signal decay, robustness towards size distributions and angular dependences of the signal decay from which accurate microstructural parameters, such as compartment size and even shape, can be extracted. Finally, we show some initial findings in d-PFG MR imaging. This review lays the foundation for future studies, in which accurate and novel microstructural information could be extracted from complex biological specimens, eventually leading to new forms of contrast in MRI.
Authors:
Noam Shemesh; Evren Ozarslan; Michal E Komlosh; Peter J Basser; Yoram Cohen
Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Intramural; Review    
Journal Detail:
Title:  NMR in biomedicine     Volume:  23     ISSN:  1099-1492     ISO Abbreviation:  NMR Biomed     Publication Date:  2010 Aug 
Date Detail:
Created Date:  2010-10-04     Completed Date:  2011-01-25     Revised Date:  2011-08-01    
Medline Journal Info:
Nlm Unique ID:  8915233     Medline TA:  NMR Biomed     Country:  England    
Other Details:
Languages:  eng     Pagination:  757-80     Citation Subset:  IM    
Copyright Information:
Copyright © 2010 John Wiley & Sons, Ltd.
Affiliation:
School of Chemistry, The Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv, Israel.
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MeSH Terms
Descriptor/Qualifier:
Animals
Diffusion
Humans
Image Processing, Computer-Assisted / methods*
Magnetic Resonance Imaging / instrumentation,  methods*
Models, Theoretical
Grant Support
ID/Acronym/Agency:
Z01 HD000266-10/HD/NICHD NIH HHS
Comments/Corrections

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