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Free‐breathing fat and R(2)* quantification in the liver using a stack‐of‐stars multi‐echo acquisition with respiratory‐resolved model‐based reconstruction

PURPOSE: To develop a free‐breathing hepatic fat and [Formula: see text] quantification method by extending a previously described stack‐of‐stars model‐based fat‐water separation technique with additional modeling of the transverse relaxation rate [Formula: see text]. METHODS: The proposed technique...

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Autores principales: Schneider, Manuel, Benkert, Thomas, Solomon, Eddy, Nickel, Dominik, Fenchel, Matthias, Kiefer, Berthold, Maier, Andreas, Chandarana, Hersh, Block, Kai Tobias
Formato: Online Artículo Texto
Lenguaje:English
Publicado: John Wiley and Sons Inc. 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7396291/
https://www.ncbi.nlm.nih.gov/pubmed/32301168
http://dx.doi.org/10.1002/mrm.28280
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author Schneider, Manuel
Benkert, Thomas
Solomon, Eddy
Nickel, Dominik
Fenchel, Matthias
Kiefer, Berthold
Maier, Andreas
Chandarana, Hersh
Block, Kai Tobias
author_facet Schneider, Manuel
Benkert, Thomas
Solomon, Eddy
Nickel, Dominik
Fenchel, Matthias
Kiefer, Berthold
Maier, Andreas
Chandarana, Hersh
Block, Kai Tobias
author_sort Schneider, Manuel
collection PubMed
description PURPOSE: To develop a free‐breathing hepatic fat and [Formula: see text] quantification method by extending a previously described stack‐of‐stars model‐based fat‐water separation technique with additional modeling of the transverse relaxation rate [Formula: see text]. METHODS: The proposed technique combines motion‐robust radial sampling using a stack‐of‐stars bipolar multi‐echo 3D GRE acquisition with iterative model‐based fat‐water separation. Parallel‐Imaging and Compressed‐Sensing principles are incorporated through modeling of the coil‐sensitivity profiles and enforcement of total‐variation (TV) sparsity on estimated water, fat, and [Formula: see text] parameter maps. Water and fat signals are used to estimate the confounder‐corrected proton‐density fat fraction (PDFF). Two strategies for handling respiratory motion are described: motion‐averaged and motion‐resolved reconstruction. Both techniques were evaluated in patients (n = 14) undergoing a hepatobiliary research protocol at 3T. PDFF and [Formula: see text] parameter maps were compared to a breath‐holding Cartesian reference approach. RESULTS: Linear regression analyses demonstrated strong (r > 0.96) and significant (P ≪ .01) correlations between radial and Cartesian PDFF measurements for both the motion‐averaged reconstruction (slope: 0.90; intercept: 0.07%) and the motion‐resolved reconstruction (slope: 0.90; intercept: 0.11%). The motion‐averaged technique overestimated hepatic [Formula: see text] values (slope: 0.35; intercept: 30.2 1/s) compared to the Cartesian reference. However, performing a respiratory‐resolved reconstruction led to better [Formula: see text] value consistency (slope: 0.77; intercept: 7.5 1/s). CONCLUSIONS: The proposed techniques are promising alternatives to conventional Cartesian imaging for fat and [Formula: see text] quantification in patients with limited breath‐holding capabilities. For accurate [Formula: see text] estimation, respiratory‐resolved reconstruction should be used.
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spelling pubmed-73962912020-08-06 Free‐breathing fat and R(2)* quantification in the liver using a stack‐of‐stars multi‐echo acquisition with respiratory‐resolved model‐based reconstruction Schneider, Manuel Benkert, Thomas Solomon, Eddy Nickel, Dominik Fenchel, Matthias Kiefer, Berthold Maier, Andreas Chandarana, Hersh Block, Kai Tobias Magn Reson Med Notes—Imaging Methodology PURPOSE: To develop a free‐breathing hepatic fat and [Formula: see text] quantification method by extending a previously described stack‐of‐stars model‐based fat‐water separation technique with additional modeling of the transverse relaxation rate [Formula: see text]. METHODS: The proposed technique combines motion‐robust radial sampling using a stack‐of‐stars bipolar multi‐echo 3D GRE acquisition with iterative model‐based fat‐water separation. Parallel‐Imaging and Compressed‐Sensing principles are incorporated through modeling of the coil‐sensitivity profiles and enforcement of total‐variation (TV) sparsity on estimated water, fat, and [Formula: see text] parameter maps. Water and fat signals are used to estimate the confounder‐corrected proton‐density fat fraction (PDFF). Two strategies for handling respiratory motion are described: motion‐averaged and motion‐resolved reconstruction. Both techniques were evaluated in patients (n = 14) undergoing a hepatobiliary research protocol at 3T. PDFF and [Formula: see text] parameter maps were compared to a breath‐holding Cartesian reference approach. RESULTS: Linear regression analyses demonstrated strong (r > 0.96) and significant (P ≪ .01) correlations between radial and Cartesian PDFF measurements for both the motion‐averaged reconstruction (slope: 0.90; intercept: 0.07%) and the motion‐resolved reconstruction (slope: 0.90; intercept: 0.11%). The motion‐averaged technique overestimated hepatic [Formula: see text] values (slope: 0.35; intercept: 30.2 1/s) compared to the Cartesian reference. However, performing a respiratory‐resolved reconstruction led to better [Formula: see text] value consistency (slope: 0.77; intercept: 7.5 1/s). CONCLUSIONS: The proposed techniques are promising alternatives to conventional Cartesian imaging for fat and [Formula: see text] quantification in patients with limited breath‐holding capabilities. For accurate [Formula: see text] estimation, respiratory‐resolved reconstruction should be used. John Wiley and Sons Inc. 2020-04-17 2020-11 /pmc/articles/PMC7396291/ /pubmed/32301168 http://dx.doi.org/10.1002/mrm.28280 Text en © 2020 The Authors. Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine This is an open access article under the terms of the http://creativecommons.org/licenses/by/4.0/ License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
spellingShingle Notes—Imaging Methodology
Schneider, Manuel
Benkert, Thomas
Solomon, Eddy
Nickel, Dominik
Fenchel, Matthias
Kiefer, Berthold
Maier, Andreas
Chandarana, Hersh
Block, Kai Tobias
Free‐breathing fat and R(2)* quantification in the liver using a stack‐of‐stars multi‐echo acquisition with respiratory‐resolved model‐based reconstruction
title Free‐breathing fat and R(2)* quantification in the liver using a stack‐of‐stars multi‐echo acquisition with respiratory‐resolved model‐based reconstruction
title_full Free‐breathing fat and R(2)* quantification in the liver using a stack‐of‐stars multi‐echo acquisition with respiratory‐resolved model‐based reconstruction
title_fullStr Free‐breathing fat and R(2)* quantification in the liver using a stack‐of‐stars multi‐echo acquisition with respiratory‐resolved model‐based reconstruction
title_full_unstemmed Free‐breathing fat and R(2)* quantification in the liver using a stack‐of‐stars multi‐echo acquisition with respiratory‐resolved model‐based reconstruction
title_short Free‐breathing fat and R(2)* quantification in the liver using a stack‐of‐stars multi‐echo acquisition with respiratory‐resolved model‐based reconstruction
title_sort free‐breathing fat and r(2)* quantification in the liver using a stack‐of‐stars multi‐echo acquisition with respiratory‐resolved model‐based reconstruction
topic Notes—Imaging Methodology
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7396291/
https://www.ncbi.nlm.nih.gov/pubmed/32301168
http://dx.doi.org/10.1002/mrm.28280
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