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Fast frequency-sweep spectroscopic imaging with an ultra-low flip angle

Magnetic resonance (MR) spectroscopic imaging has become an important tool in clinical settings for noninvasively obtaining spatial and metabolic information on a molecular scale. Conventional spectroscopic imaging is acquired in the time domain, and its clinical application is limited by the long a...

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Autores principales: Guo, Junyu, Patay, Zoltan, Reddick, Wilburn E.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group 2016
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4954958/
https://www.ncbi.nlm.nih.gov/pubmed/27440077
http://dx.doi.org/10.1038/srep30066
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author Guo, Junyu
Patay, Zoltan
Reddick, Wilburn E.
author_facet Guo, Junyu
Patay, Zoltan
Reddick, Wilburn E.
author_sort Guo, Junyu
collection PubMed
description Magnetic resonance (MR) spectroscopic imaging has become an important tool in clinical settings for noninvasively obtaining spatial and metabolic information on a molecular scale. Conventional spectroscopic imaging is acquired in the time domain, and its clinical application is limited by the long acquisition time, restricted spatial coverage, and complex suppression and reconstruction procedures. We introduce a fast MR spectroscopic imaging technique in the frequency domain, termed phase-cycled spectroscopic imaging (PCSI). PCSI uses a balanced steady-state free precession (bSSFP) sequence with an ultra-low flip angle to achieve very high acquisition efficiency with a short repetition time. This approach enables faster frequency sweeping by changing the cycled RF phase and using flexible non-uniform sampling, and it greatly reduces the RF energy deposition in tissue. With its intrinsic water and fat suppression, PCSI more closely resembles routine clinical scans because it eliminates the suppression steps. We demonstrate that it is feasible to acquire PCSI spectra in a phantom and in humans and that PCSI provides an efficient spectroscopic imaging method, even for J-coupled metabolites. PCSI may enable spectroscopic imaging to play a larger role in the clinical assessment of the spatial tissue distribution of metabolites.
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spelling pubmed-49549582016-07-26 Fast frequency-sweep spectroscopic imaging with an ultra-low flip angle Guo, Junyu Patay, Zoltan Reddick, Wilburn E. Sci Rep Article Magnetic resonance (MR) spectroscopic imaging has become an important tool in clinical settings for noninvasively obtaining spatial and metabolic information on a molecular scale. Conventional spectroscopic imaging is acquired in the time domain, and its clinical application is limited by the long acquisition time, restricted spatial coverage, and complex suppression and reconstruction procedures. We introduce a fast MR spectroscopic imaging technique in the frequency domain, termed phase-cycled spectroscopic imaging (PCSI). PCSI uses a balanced steady-state free precession (bSSFP) sequence with an ultra-low flip angle to achieve very high acquisition efficiency with a short repetition time. This approach enables faster frequency sweeping by changing the cycled RF phase and using flexible non-uniform sampling, and it greatly reduces the RF energy deposition in tissue. With its intrinsic water and fat suppression, PCSI more closely resembles routine clinical scans because it eliminates the suppression steps. We demonstrate that it is feasible to acquire PCSI spectra in a phantom and in humans and that PCSI provides an efficient spectroscopic imaging method, even for J-coupled metabolites. PCSI may enable spectroscopic imaging to play a larger role in the clinical assessment of the spatial tissue distribution of metabolites. Nature Publishing Group 2016-07-21 /pmc/articles/PMC4954958/ /pubmed/27440077 http://dx.doi.org/10.1038/srep30066 Text en Copyright © 2016, Macmillan Publishers Limited http://creativecommons.org/licenses/by/4.0/ This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/
spellingShingle Article
Guo, Junyu
Patay, Zoltan
Reddick, Wilburn E.
Fast frequency-sweep spectroscopic imaging with an ultra-low flip angle
title Fast frequency-sweep spectroscopic imaging with an ultra-low flip angle
title_full Fast frequency-sweep spectroscopic imaging with an ultra-low flip angle
title_fullStr Fast frequency-sweep spectroscopic imaging with an ultra-low flip angle
title_full_unstemmed Fast frequency-sweep spectroscopic imaging with an ultra-low flip angle
title_short Fast frequency-sweep spectroscopic imaging with an ultra-low flip angle
title_sort fast frequency-sweep spectroscopic imaging with an ultra-low flip angle
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4954958/
https://www.ncbi.nlm.nih.gov/pubmed/27440077
http://dx.doi.org/10.1038/srep30066
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