Document Detail


A simple low-SAR technique for chemical-shift selection with high-field spin-echo imaging.
MedLine Citation:
PMID:  20574987     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
We have discovered a simple and highly robust method for removal of chemical shift artifact in spin-echo MR images, which simultaneously decreases the radiofrequency power deposition (specific absorption rate). The method is demonstrated in spin-echo echo-planar imaging brain images acquired at 7 T, with complete suppression of scalp fat signal. When excitation and refocusing pulses are sufficiently different in duration, and thus also different in the amplitude of their slice-select gradients, a spatial mismatch is produced between the fat slices excited and refocused, with no overlap. Because no additional radiofrequency pulse is used to suppress fat, the specific absorption rate is significantly reduced compared with conventional approaches. This enables greater volume coverage per unit time, well suited for functional and diffusion studies using spin-echo echo-planar imaging. Moreover, the method can be generally applied to any sequence involving slice-selective excitation and at least one slice-selective refocusing pulse at high magnetic field strengths. The method is more efficient than gradient reversal methods and more robust against inhomogeneities of the static (polarizing) field (B(0)).
Authors:
Dimo Ivanov; Andreas Schäfer; Markus N Streicher; Robin M Heidemann; Robert Trampel; Robert Turner
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Magnetic resonance in medicine : official journal of the Society of Magnetic Resonance in Medicine / Society of Magnetic Resonance in Medicine     Volume:  64     ISSN:  1522-2594     ISO Abbreviation:  Magn Reson Med     Publication Date:  2010 Aug 
Date Detail:
Created Date:  2010-07-28     Completed Date:  2011-01-04     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  8505245     Medline TA:  Magn Reson Med     Country:  United States    
Other Details:
Languages:  eng     Pagination:  319-26     Citation Subset:  IM    
Affiliation:
Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany. divanov@cbs.mpg.de
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MeSH Terms
Descriptor/Qualifier:
Algorithms*
Brain / anatomy & histology*
Brain Chemistry*
Echo-Planar Imaging / methods*
Humans
Image Enhancement / methods*
Image Interpretation, Computer-Assisted / methods*
Reproducibility of Results
Sensitivity and Specificity
Spin Labels
Chemical
Reg. No./Substance:
0/Spin Labels

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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