Generalized inhomogeneity‐resilient relaxation along a fictitious field (girRAFF) for improved robustness in rotating frame relaxometry at 3T.
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| Title: | Generalized inhomogeneity‐resilient relaxation along a fictitious field (girRAFF) for improved robustness in rotating frame relaxometry at 3T. |
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| Authors: | Coletti, Chiara1 (AUTHOR), Naaktgeboren, Roeland1 (AUTHOR), Tourais, Joao1 (AUTHOR), Van De Steeg‐Henzen, Christal2 (AUTHOR), Weingärtner, Sebastian1,2 (AUTHOR) S.Weingartner@tudelft.nl |
| Source: | Magnetic Resonance in Medicine. Dec2024, Vol. 92 Issue 6, p2373-2391. 19p. |
| Subjects: | Calf muscles, Map design, Cartilage, Calves, Knee |
| Abstract: | Purpose: To optimize Relaxation along a Fictitious Field (RAFF) pulses for rotating frame relaxometry with improved robustness in the presence of B0$$ {\mathrm{B}}_0 $$ and B1+$$ {\mathrm{B}}_1^{+} $$ field inhomogeneities. Methods: The resilience of RAFF pulses against B0$$ {\mathrm{B}}_0 $$ and B1+$$ {\mathrm{B}}_1^{+} $$ inhomogeneities was studied using Bloch simulations. A parameterized extension of the RAFF formulation was introduced and used to derive a generalized inhomogeneity‐resilient RAFF (girRAFF) pulse. RAFF and girRAFF preparation efficiency, defined as the ratio of the longitudinal magnetization before and after the preparation (Mz(Tp)/M0$$ {M}_z\left({T}_p\right)/{M}_0 $$), were simulated and validated in phantom experiments. TRAFF$$ {T}_{\mathrm{RAFF}} $$ and TgirRAFF$$ {T}_{\mathrm{girRAFF}} $$ parametric maps were acquired at 3T in phantom, the calf muscle, and the knee cartilage of healthy subjects. The relaxation time maps were analyzed for resilience against artificially induced field inhomogeneities and assessed in terms of in vivo reproducibility. Results: Optimized girRAFF preparations yielded improved preparation efficiency (0.95/0.91 simulations/phantom) with respect to RAFF (0.36/0.67 simulations/phantom). TgirRAFF$$ {T}_{\mathrm{girRAFF}} $$ preparations showed in phantom/calf 6.0/4.8 times higher resilience to B0$$ {\mathrm{B}}_0 $$ inhomogeneities than RAFF, and a 4.7/5.3 improved resilience to B1+$$ {\mathrm{B}}_1^{+} $$ inhomogeneities. In the knee cartilage, TgirRAFF$$ {T}_{\mathrm{girRAFF}} $$ (53 ±$$ \pm $$ 14 ms) was higher than TRAFF$$ {T}_{\mathrm{RAFF}} $$ (42 ±$$ \pm $$ 11 ms). Moreover, girRAFF preparations yielded 7.6/4.9 times improved reproducibility across B0$$ {\mathrm{B}}_0 $$/B1+$$ {\mathrm{B}}_1^{+} $$ inhomogeneity conditions, 1.9 times better reproducibility across subjects and 1.2 times across slices compared with RAFF. Dixon‐based fat suppression led to a further 15‐fold improvement in the robustness of girRAFF to inhomogeneities. Conclusions: RAFF pulses display residual sensitivity to off‐resonance and pronounced sensitivity to B1+$$ {\mathrm{B}}_1^{+} $$ inhomogeneities. Optimized girRAFF pulses provide increased robustness and may be an appealing alternative for applications where resilience against field inhomogeneities is required. [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: 179962626 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
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| Items | – Name: Title Label: Title Group: Ti Data: Generalized inhomogeneity‐resilient relaxation along a fictitious field (girRAFF) for improved robustness in rotating frame relaxometry at 3T. – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Coletti%2C+Chiara%22">Coletti, Chiara</searchLink><relatesTo>1</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Naaktgeboren%2C+Roeland%22">Naaktgeboren, Roeland</searchLink><relatesTo>1</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Tourais%2C+Joao%22">Tourais, Joao</searchLink><relatesTo>1</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Van+De+Steeg‐Henzen%2C+Christal%22">Van De Steeg‐Henzen, Christal</searchLink><relatesTo>2</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Weingärtner%2C+Sebastian%22">Weingärtner, Sebastian</searchLink><relatesTo>1,2</relatesTo> (AUTHOR)<i> S.Weingartner@tudelft.nl</i> – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22Magnetic+Resonance+in+Medicine%22">Magnetic Resonance in Medicine</searchLink>. Dec2024, Vol. 92 Issue 6, p2373-2391. 19p. – Name: Subject Label: Subjects Group: Su Data: <searchLink fieldCode="DE" term="%22Calf+muscles%22">Calf muscles</searchLink><br /><searchLink fieldCode="DE" term="%22Map+design%22">Map design</searchLink><br /><searchLink fieldCode="DE" term="%22Cartilage%22">Cartilage</searchLink><br /><searchLink fieldCode="DE" term="%22Calves%22">Calves</searchLink><br /><searchLink fieldCode="DE" term="%22Knee%22">Knee</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: Purpose: To optimize Relaxation along a Fictitious Field (RAFF) pulses for rotating frame relaxometry with improved robustness in the presence of B0$$ {\mathrm{B}}_0 $$ and B1+$$ {\mathrm{B}}_1^{+} $$ field inhomogeneities. Methods: The resilience of RAFF pulses against B0$$ {\mathrm{B}}_0 $$ and B1+$$ {\mathrm{B}}_1^{+} $$ inhomogeneities was studied using Bloch simulations. A parameterized extension of the RAFF formulation was introduced and used to derive a generalized inhomogeneity‐resilient RAFF (girRAFF) pulse. RAFF and girRAFF preparation efficiency, defined as the ratio of the longitudinal magnetization before and after the preparation (Mz(Tp)/M0$$ {M}_z\left({T}_p\right)/{M}_0 $$), were simulated and validated in phantom experiments. TRAFF$$ {T}_{\mathrm{RAFF}} $$ and TgirRAFF$$ {T}_{\mathrm{girRAFF}} $$ parametric maps were acquired at 3T in phantom, the calf muscle, and the knee cartilage of healthy subjects. The relaxation time maps were analyzed for resilience against artificially induced field inhomogeneities and assessed in terms of in vivo reproducibility. Results: Optimized girRAFF preparations yielded improved preparation efficiency (0.95/0.91 simulations/phantom) with respect to RAFF (0.36/0.67 simulations/phantom). TgirRAFF$$ {T}_{\mathrm{girRAFF}} $$ preparations showed in phantom/calf 6.0/4.8 times higher resilience to B0$$ {\mathrm{B}}_0 $$ inhomogeneities than RAFF, and a 4.7/5.3 improved resilience to B1+$$ {\mathrm{B}}_1^{+} $$ inhomogeneities. In the knee cartilage, TgirRAFF$$ {T}_{\mathrm{girRAFF}} $$ (53 ±$$ \pm $$ 14 ms) was higher than TRAFF$$ {T}_{\mathrm{RAFF}} $$ (42 ±$$ \pm $$ 11 ms). Moreover, girRAFF preparations yielded 7.6/4.9 times improved reproducibility across B0$$ {\mathrm{B}}_0 $$/B1+$$ {\mathrm{B}}_1^{+} $$ inhomogeneity conditions, 1.9 times better reproducibility across subjects and 1.2 times across slices compared with RAFF. Dixon‐based fat suppression led to a further 15‐fold improvement in the robustness of girRAFF to inhomogeneities. Conclusions: RAFF pulses display residual sensitivity to off‐resonance and pronounced sensitivity to B1+$$ {\mathrm{B}}_1^{+} $$ inhomogeneities. Optimized girRAFF pulses provide increased robustness and may be an appealing alternative for applications where resilience against field inhomogeneities is required. [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.30219 Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 19 StartPage: 2373 Subjects: – SubjectFull: Calf muscles Type: general – SubjectFull: Map design Type: general – SubjectFull: Cartilage Type: general – SubjectFull: Calves Type: general – SubjectFull: Knee Type: general Titles: – TitleFull: Generalized inhomogeneity‐resilient relaxation along a fictitious field (girRAFF) for improved robustness in rotating frame relaxometry at 3T. Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Coletti, Chiara – PersonEntity: Name: NameFull: Naaktgeboren, Roeland – PersonEntity: Name: NameFull: Tourais, Joao – PersonEntity: Name: NameFull: Van De Steeg‐Henzen, Christal – PersonEntity: Name: NameFull: Weingärtner, Sebastian IsPartOfRelationships: – BibEntity: Dates: – D: 01 M: 12 Text: Dec2024 Type: published Y: 2024 Identifiers: – Type: issn-print Value: 07403194 Numbering: – Type: volume Value: 92 – Type: issue Value: 6 Titles: – TitleFull: Magnetic Resonance in Medicine Type: main |
| ResultId | 1 |
