Parallel transmit pulse design for patients with deep brain stimulation implants
Purpose Specific absorption rate (SAR) amplification around active implantable medical devices during diagnostic MRI procedures poses a potential risk for patient safety. In this study, we present a parallel transmit (pTx) strategy that can be used to safely scan patients with deep brain stimulat...
| Main Authors: | , , , , , , , , , , |
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| Other Authors: | |
| Format: | Article |
| Language: | en_US |
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Wiley Blackwell
2017
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| Online Access: | http://hdl.handle.net/1721.1/110737 https://orcid.org/0000-0001-7208-8863 https://orcid.org/0000-0002-7637-2914 |
| _version_ | 1826202725329666048 |
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| author | Guerin, Bastien Akgun, Can Martin, Adrian Torrado-Carvajal, Angel Malpica, Norberto Hernandez-Tamames, Juan A. Schiavi, Emanuele Eryaman, Yigitcan Lopez Herraiz, Joaquin Adalsteinsson, Elfar Wald, Lawrence |
| author2 | Institute for Medical Engineering and Science |
| author_facet | Institute for Medical Engineering and Science Guerin, Bastien Akgun, Can Martin, Adrian Torrado-Carvajal, Angel Malpica, Norberto Hernandez-Tamames, Juan A. Schiavi, Emanuele Eryaman, Yigitcan Lopez Herraiz, Joaquin Adalsteinsson, Elfar Wald, Lawrence |
| author_sort | Guerin, Bastien |
| collection | MIT |
| description | Purpose
Specific absorption rate (SAR) amplification around active implantable medical devices during diagnostic MRI procedures poses a potential risk for patient safety. In this study, we present a parallel transmit (pTx) strategy that can be used to safely scan patients with deep brain stimulation (DBS) implants.
Methods
We performed electromagnetic simulations at 3T using a uniform phantom and a multitissue realistic head model with a generic DBS implant. Our strategy is based on using implant-friendly modes, which are defined as the modes of an array that reduce the local SAR around the DBS lead tip. These modes are used in a spokes pulse design algorithm in order to produce highly uniform magnitude least-squares flip angle excitations.
Results
Local SAR (1 g) at the lead tip is reduced below 0.1 W/kg compared with 31.2 W/kg, which is obtained by a simple quadrature birdcage excitation without any sort of SAR mitigation. For the multitissue realistic head model, peak 10 g local SAR and global SAR are obtained as 4.52 W/kg and 0.48 W/kg, respectively. A uniform axial flip angle is also obtained (NRMSE <3%).
Conclusion
Parallel transmit arrays can be used to generate implant-friendly modes and to reduce SAR around DBS implants while constraining peak local SAR and global SAR and maximizing flip angle homogeneity. Magn Reson Med 73:1896–1903, 2015. |
| first_indexed | 2024-09-23T12:16:14Z |
| format | Article |
| id | mit-1721.1/110737 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T12:16:14Z |
| publishDate | 2017 |
| publisher | Wiley Blackwell |
| record_format | dspace |
| spelling | mit-1721.1/1107372022-09-28T00:52:50Z Parallel transmit pulse design for patients with deep brain stimulation implants Guerin, Bastien Akgun, Can Martin, Adrian Torrado-Carvajal, Angel Malpica, Norberto Hernandez-Tamames, Juan A. Schiavi, Emanuele Eryaman, Yigitcan Lopez Herraiz, Joaquin Adalsteinsson, Elfar Wald, Lawrence Institute for Medical Engineering and Science Harvard University--MIT Division of Health Sciences and Technology Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science Massachusetts Institute of Technology. Research Laboratory of Electronics Eryaman, Yigitcan Lopez Herraiz, Joaquin Adalsteinsson, Elfar Wald, Lawrence Purpose Specific absorption rate (SAR) amplification around active implantable medical devices during diagnostic MRI procedures poses a potential risk for patient safety. In this study, we present a parallel transmit (pTx) strategy that can be used to safely scan patients with deep brain stimulation (DBS) implants. Methods We performed electromagnetic simulations at 3T using a uniform phantom and a multitissue realistic head model with a generic DBS implant. Our strategy is based on using implant-friendly modes, which are defined as the modes of an array that reduce the local SAR around the DBS lead tip. These modes are used in a spokes pulse design algorithm in order to produce highly uniform magnitude least-squares flip angle excitations. Results Local SAR (1 g) at the lead tip is reduced below 0.1 W/kg compared with 31.2 W/kg, which is obtained by a simple quadrature birdcage excitation without any sort of SAR mitigation. For the multitissue realistic head model, peak 10 g local SAR and global SAR are obtained as 4.52 W/kg and 0.48 W/kg, respectively. A uniform axial flip angle is also obtained (NRMSE <3%). Conclusion Parallel transmit arrays can be used to generate implant-friendly modes and to reduce SAR around DBS implants while constraining peak local SAR and global SAR and maximizing flip angle homogeneity. Magn Reson Med 73:1896–1903, 2015. National Institute of Biomedical Imaging and Bioengineering (U.S.) (R01EB006847) National Institute of Biomedical Imaging and Bioengineering (U.S.) (R01EB007942) 2017-07-17T18:01:20Z 2017-07-17T18:01:20Z 2015-04 2014-05 Article http://purl.org/eprint/type/JournalArticle 0740-3194 1522-2594 http://hdl.handle.net/1721.1/110737 Eryaman, Yigitcan; Guerin, Bastien; Akgun, Can et al. “Parallel Transmit Pulse Design for Patients with Deep Brain Stimulation Implants.” Magnetic Resonance in Medicine 73, 5 (June 2014): 1896–1903 © 2014 Wiley Periodicals, Inc https://orcid.org/0000-0001-7208-8863 https://orcid.org/0000-0002-7637-2914 en_US http://dx.doi.org/10.1002/mrm.25324 Magnetic Resonance in Medicine Creative Commons Attribution-Noncommercial-Share Alike http://creativecommons.org/licenses/by-nc-sa/4.0/ application/pdf Wiley Blackwell PMC |
| spellingShingle | Guerin, Bastien Akgun, Can Martin, Adrian Torrado-Carvajal, Angel Malpica, Norberto Hernandez-Tamames, Juan A. Schiavi, Emanuele Eryaman, Yigitcan Lopez Herraiz, Joaquin Adalsteinsson, Elfar Wald, Lawrence Parallel transmit pulse design for patients with deep brain stimulation implants |
| title | Parallel transmit pulse design for patients with deep brain stimulation implants |
| title_full | Parallel transmit pulse design for patients with deep brain stimulation implants |
| title_fullStr | Parallel transmit pulse design for patients with deep brain stimulation implants |
| title_full_unstemmed | Parallel transmit pulse design for patients with deep brain stimulation implants |
| title_short | Parallel transmit pulse design for patients with deep brain stimulation implants |
| title_sort | parallel transmit pulse design for patients with deep brain stimulation implants |
| url | http://hdl.handle.net/1721.1/110737 https://orcid.org/0000-0001-7208-8863 https://orcid.org/0000-0002-7637-2914 |
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