Cargando…
Short echo time dual-frequency MR Elastography with Optimal Control RF pulses
Magnetic Resonance Elastography (MRE) quantifies the mechanical properties of tissues, typically applying motion encoding gradients (MEG). Multifrequency results allow better characterizations of tissues using data usually acquired through sequential monofrequency experiments. High frequencies are d...
Autores principales: | , , , , , , |
---|---|
Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Nature Publishing Group UK
2022
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8791955/ https://www.ncbi.nlm.nih.gov/pubmed/35082303 http://dx.doi.org/10.1038/s41598-022-05262-3 |
_version_ | 1784640300666322944 |
---|---|
author | Sango-Solanas, Pilar Tse Ve Koon, Kevin Van Reeth, Eric Ratiney, Helene Millioz, Fabien Caussy, Cyrielle Beuf, Olivier |
author_facet | Sango-Solanas, Pilar Tse Ve Koon, Kevin Van Reeth, Eric Ratiney, Helene Millioz, Fabien Caussy, Cyrielle Beuf, Olivier |
author_sort | Sango-Solanas, Pilar |
collection | PubMed |
description | Magnetic Resonance Elastography (MRE) quantifies the mechanical properties of tissues, typically applying motion encoding gradients (MEG). Multifrequency results allow better characterizations of tissues using data usually acquired through sequential monofrequency experiments. High frequencies are difficult to reach due to slew rate limitations and low frequencies induce long TEs, yielding magnitude images with low SNR. We propose a novel strategy to perform simultaneous multifrequency MRE in the absence of MEGs: using RF pulses designed via the Optimal Control (OC) theory. Such pulses control the spatial distribution of the MRI magnetization phase so that the resulting transverse magnetization reproduces the phase pattern of an MRE acquisition. The pulse is applied with a constant gradient during the multifrequency mechanical excitation to simultaneously achieve slice selection and motion encoding. The phase offset sampling strategy can be adapted according to the excitation frequencies to reduce the acquisition time. Phantom experiments were run to compare the classical monofrequency MRE to the OC based dual-frequency MRE method and showed excellent agreement between the reconstructed shear storage modulus G′. Our method could be applied to simultaneously acquire low and high frequency components, which are difficult to encode with the classical MEG MRE strategy. |
format | Online Article Text |
id | pubmed-8791955 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2022 |
publisher | Nature Publishing Group UK |
record_format | MEDLINE/PubMed |
spelling | pubmed-87919552022-01-27 Short echo time dual-frequency MR Elastography with Optimal Control RF pulses Sango-Solanas, Pilar Tse Ve Koon, Kevin Van Reeth, Eric Ratiney, Helene Millioz, Fabien Caussy, Cyrielle Beuf, Olivier Sci Rep Article Magnetic Resonance Elastography (MRE) quantifies the mechanical properties of tissues, typically applying motion encoding gradients (MEG). Multifrequency results allow better characterizations of tissues using data usually acquired through sequential monofrequency experiments. High frequencies are difficult to reach due to slew rate limitations and low frequencies induce long TEs, yielding magnitude images with low SNR. We propose a novel strategy to perform simultaneous multifrequency MRE in the absence of MEGs: using RF pulses designed via the Optimal Control (OC) theory. Such pulses control the spatial distribution of the MRI magnetization phase so that the resulting transverse magnetization reproduces the phase pattern of an MRE acquisition. The pulse is applied with a constant gradient during the multifrequency mechanical excitation to simultaneously achieve slice selection and motion encoding. The phase offset sampling strategy can be adapted according to the excitation frequencies to reduce the acquisition time. Phantom experiments were run to compare the classical monofrequency MRE to the OC based dual-frequency MRE method and showed excellent agreement between the reconstructed shear storage modulus G′. Our method could be applied to simultaneously acquire low and high frequency components, which are difficult to encode with the classical MEG MRE strategy. Nature Publishing Group UK 2022-01-26 /pmc/articles/PMC8791955/ /pubmed/35082303 http://dx.doi.org/10.1038/s41598-022-05262-3 Text en © The Author(s) 2022 https://creativecommons.org/licenses/by/4.0/Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/ (https://creativecommons.org/licenses/by/4.0/) . |
spellingShingle | Article Sango-Solanas, Pilar Tse Ve Koon, Kevin Van Reeth, Eric Ratiney, Helene Millioz, Fabien Caussy, Cyrielle Beuf, Olivier Short echo time dual-frequency MR Elastography with Optimal Control RF pulses |
title | Short echo time dual-frequency MR Elastography with Optimal Control RF pulses |
title_full | Short echo time dual-frequency MR Elastography with Optimal Control RF pulses |
title_fullStr | Short echo time dual-frequency MR Elastography with Optimal Control RF pulses |
title_full_unstemmed | Short echo time dual-frequency MR Elastography with Optimal Control RF pulses |
title_short | Short echo time dual-frequency MR Elastography with Optimal Control RF pulses |
title_sort | short echo time dual-frequency mr elastography with optimal control rf pulses |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8791955/ https://www.ncbi.nlm.nih.gov/pubmed/35082303 http://dx.doi.org/10.1038/s41598-022-05262-3 |
work_keys_str_mv | AT sangosolanaspilar shortechotimedualfrequencymrelastographywithoptimalcontrolrfpulses AT tsevekoonkevin shortechotimedualfrequencymrelastographywithoptimalcontrolrfpulses AT vanreetheric shortechotimedualfrequencymrelastographywithoptimalcontrolrfpulses AT ratineyhelene shortechotimedualfrequencymrelastographywithoptimalcontrolrfpulses AT milliozfabien shortechotimedualfrequencymrelastographywithoptimalcontrolrfpulses AT caussycyrielle shortechotimedualfrequencymrelastographywithoptimalcontrolrfpulses AT beufolivier shortechotimedualfrequencymrelastographywithoptimalcontrolrfpulses |