Amide mapping in the human brain using downfield MRSI at 3 T and 7 T.
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| Title: | Amide mapping in the human brain using downfield MRSI at 3 T and 7 T. |
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| Authors: | Özdemir, İpek1,2 (AUTHOR) iozdemi1@jhmi.edu, Etyemez, Semra3,4 (AUTHOR), Barker, Peter B.1,5 (AUTHOR) |
| Source: | Magnetic Resonance in Medicine. Jun2025, Vol. 93 Issue 6, p2254-2262. 9p. |
| Subjects: | Magnetic resonance imaging, Spectroscopic imaging, Magnetic fields, Brain mapping, Integrated software |
| Abstract: | Purpose: To quantitatively compare signal‐to‐noise ratios (SNRs), linewidth values, and Cramér‐Rao lower bounds (CRLBs) for amide resonances in the human brain measured at 3T and 7T using downfield MR spectroscopic imaging (DF‐MRSI). Methods: Seven normal volunteers (25–52 years, 5 female) were imaged using Philips 3T Elition and 7T Achieva scanners. Both systems have 32‐channel receive head coils and 16‐channel local shim arrays (MRShim GmbH) in addition to high‐order spherical harmonic shims. Three‐dimensional DF‐MRSI data were collected using a previously developed pulse sequence with spectral‐spatial excitation and frequency‐selective refocusing pulses. Matched imaging protocols on both field strengths were applied to achieve a nominal voxel size of 7 × 7 × 15 mm in a scan time of 10.6 min. Spectral analysis was performed using the "LCModel" software package. SNR and CRLB values (%) were compared between 3T and 7T data using univariate general linear models. Results: Significantly increased amide SNR and decreased CRLB values (p < 0.05) were found at 7T. Averaged over all brain regions, SNR was 2.9 ± 1.1 at 3T and 5.4 ± 1.5 at 7T, and CRLBs were 11.4 ± 3.9 and 4.9 ± 1.5 respectively. 7T MRI and amide images did show some regional signal dropoff due to transmit B1 inhomogeneity, however. Conclusion: Three‐dimensional DF‐MRSI at 7T showed 86% increased SNR and 57% decreased CRLB values compared with 3T, confirming the expected improvements at higher field. Improvements are probably due to multiple factors, including higher magnetization at 7T, the shorter minimum echo time available, among others. [ABSTRACT FROM AUTHOR] |
| Copyright of Magnetic Resonance in Medicine is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
| Database: | Engineering Source |
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| Header | DbId: egs DbLabel: Engineering Source An: 184274809 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
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| Items | – Name: Title Label: Title Group: Ti Data: Amide mapping in the human brain using downfield MRSI at 3 T and 7 T. – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Özdemir%2C+İpek%22">Özdemir, İpek</searchLink><relatesTo>1,2</relatesTo> (AUTHOR)<i> iozdemi1@jhmi.edu</i><br /><searchLink fieldCode="AR" term="%22Etyemez%2C+Semra%22">Etyemez, Semra</searchLink><relatesTo>3,4</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Barker%2C+Peter+B%2E%22">Barker, Peter B.</searchLink><relatesTo>1,5</relatesTo> (AUTHOR) – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22Magnetic+Resonance+in+Medicine%22">Magnetic Resonance in Medicine</searchLink>. Jun2025, Vol. 93 Issue 6, p2254-2262. 9p. – Name: Subject Label: Subjects Group: Su Data: <searchLink fieldCode="DE" term="%22Magnetic+resonance+imaging%22">Magnetic resonance imaging</searchLink><br /><searchLink fieldCode="DE" term="%22Spectroscopic+imaging%22">Spectroscopic imaging</searchLink><br /><searchLink fieldCode="DE" term="%22Magnetic+fields%22">Magnetic fields</searchLink><br /><searchLink fieldCode="DE" term="%22Brain+mapping%22">Brain mapping</searchLink><br /><searchLink fieldCode="DE" term="%22Integrated+software%22">Integrated software</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: Purpose: To quantitatively compare signal‐to‐noise ratios (SNRs), linewidth values, and Cramér‐Rao lower bounds (CRLBs) for amide resonances in the human brain measured at 3T and 7T using downfield MR spectroscopic imaging (DF‐MRSI). Methods: Seven normal volunteers (25–52 years, 5 female) were imaged using Philips 3T Elition and 7T Achieva scanners. Both systems have 32‐channel receive head coils and 16‐channel local shim arrays (MRShim GmbH) in addition to high‐order spherical harmonic shims. Three‐dimensional DF‐MRSI data were collected using a previously developed pulse sequence with spectral‐spatial excitation and frequency‐selective refocusing pulses. Matched imaging protocols on both field strengths were applied to achieve a nominal voxel size of 7 × 7 × 15 mm in a scan time of 10.6 min. Spectral analysis was performed using the "LCModel" software package. SNR and CRLB values (%) were compared between 3T and 7T data using univariate general linear models. Results: Significantly increased amide SNR and decreased CRLB values (p < 0.05) were found at 7T. Averaged over all brain regions, SNR was 2.9 ± 1.1 at 3T and 5.4 ± 1.5 at 7T, and CRLBs were 11.4 ± 3.9 and 4.9 ± 1.5 respectively. 7T MRI and amide images did show some regional signal dropoff due to transmit B1 inhomogeneity, however. Conclusion: Three‐dimensional DF‐MRSI at 7T showed 86% increased SNR and 57% decreased CRLB values compared with 3T, confirming the expected improvements at higher field. Improvements are probably due to multiple factors, including higher magnetization at 7T, the shorter minimum echo time available, among others. [ABSTRACT FROM AUTHOR] – Name: AbstractSuppliedCopyright Label: Group: Ab Data: <i>Copyright of Magnetic Resonance in Medicine is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.) |
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| RecordInfo | BibRecord: BibEntity: Identifiers: – Type: doi Value: 10.1002/mrm.30458 Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 9 StartPage: 2254 Subjects: – SubjectFull: Magnetic resonance imaging Type: general – SubjectFull: Spectroscopic imaging Type: general – SubjectFull: Magnetic fields Type: general – SubjectFull: Brain mapping Type: general – SubjectFull: Integrated software Type: general Titles: – TitleFull: Amide mapping in the human brain using downfield MRSI at 3 T and 7 T. Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Özdemir, İpek – PersonEntity: Name: NameFull: Etyemez, Semra – PersonEntity: Name: NameFull: Barker, Peter B. IsPartOfRelationships: – BibEntity: Dates: – D: 01 M: 06 Text: Jun2025 Type: published Y: 2025 Identifiers: – Type: issn-print Value: 07403194 Numbering: – Type: volume Value: 93 – Type: issue Value: 6 Titles: – TitleFull: Magnetic Resonance in Medicine Type: main |
| ResultId | 1 |
