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Licht C, Reichert S, Bydder M, Zapp J, Corella S, Guye M, Zöllner FG, Schad LR, Rapacchi S. Low-rank reconstruction for simultaneous double half-echo 23Na and undersampled 23Na multi-quantum coherences MRI. Magn Reson Med 2024; 92:1440-1455. [PMID: 38725430 DOI: 10.1002/mrm.30132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Revised: 03/05/2024] [Accepted: 04/08/2024] [Indexed: 07/23/2024]
Abstract
PURPOSE To develop a new sequence to simultaneously acquire Cartesian sodium (23Na) MRI and accelerated Cartesian single (SQ) and triple quantum (TQ) sodium MRI of in vivo human brain at 7 T by leveraging two dedicated low-rank reconstruction frameworks. THEORY AND METHODS The Double Half-Echo technique enables short echo time Cartesian 23Na MRI and acquires two k-space halves, reconstructed by a low-rank coupling constraint. Additionally, three-dimensional (3D) 23Na Multi-Quantum Coherences (MQC) MRI requires multi-echo sampling paired with phase-cycling, exhibiting a redundant multidimensional space. Simultaneous Autocalibrating and k-Space Estimation (SAKE) were used to reconstruct highly undersampled 23Na MQC MRI. Reconstruction performance was assessed against five-dimensional (5D) CS, evaluating structural similarity index (SSIM), root mean squared error (RMSE), signal-to-noise ratio (SNR), and quantification of tissue sodium concentration and TQ/SQ ratio in silico, in vitro, and in vivo. RESULTS The proposed sequence enabled the simultaneous acquisition of fully sampled 23Na MRI while leveraging prospective undersampling for 23Na MQC MRI. SAKE improved TQ image reconstruction regarding SSIM by 6% and reduced RMSE by 35% compared to 5D CS in vivo. Thanks to prospective undersampling, the spatial resolution of 23Na MQC MRI was enhanced from8 × 8 × 15 $$ 8\times 8\times 15 $$ mm3 to8 × 8 × 8 $$ 8\times 8\times 8 $$ mm3 while reducing acquisition time from2 × 31 $$ 2\times 31 $$ min to2 × 23 $$ 2\times 23 $$ min. CONCLUSION The proposed sequence, coupled with low-rank reconstructions, provides an efficient framework for comprehensive whole-brain sodium MRI, combining TSC, T2*, and TQ/SQ ratio estimations. Additionally, low-rank matrix completion enables the reconstruction of highly undersampled 23Na MQC MRI, allowing for accelerated acquisition or enhanced spatial resolution.
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Affiliation(s)
- Christian Licht
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
- Mannheim Institute for Intelligent Systems in Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Simon Reichert
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
- Mannheim Institute for Intelligent Systems in Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Mark Bydder
- Aix-Marseille Univ, CNRS, CRMBM, Marseille, France
| | - Jascha Zapp
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
- Mannheim Institute for Intelligent Systems in Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Shirley Corella
- Aix-Marseille Univ, CNRS, CRMBM, Marseille, France
- APHM, CEMEREM, Hôpital Universitaire Timone, Marseille, France
| | - Maxime Guye
- Aix-Marseille Univ, CNRS, CRMBM, Marseille, France
- APHM, CEMEREM, Hôpital Universitaire Timone, Marseille, France
| | - Frank G Zöllner
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
- Mannheim Institute for Intelligent Systems in Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Lothar R Schad
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
- Mannheim Institute for Intelligent Systems in Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Stanislas Rapacchi
- Aix-Marseille Univ, CNRS, CRMBM, Marseille, France
- APHM, CEMEREM, Hôpital Universitaire Timone, Marseille, France
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Reichert S, Schepkin V, Kleimaier D, Zöllner FG, Schad LR. Sodium triple quantum MR signal extraction using a single-pulse sequence with single quantum time efficiency. Magn Reson Med 2024; 92:900-915. [PMID: 38650306 DOI: 10.1002/mrm.30107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 02/25/2024] [Accepted: 03/20/2024] [Indexed: 04/25/2024]
Abstract
PURPOSE Sodium triple quantum (TQ) signal has been shown to be a valuable biomarker for cell viability. Despite its clinical potential, application of Sodium TQ signal is hindered by complex pulse sequences with long scan times. This study proposes a method to approximate the TQ signal using a single excitation pulse without phase cycling. METHODS The proposed method is based on a single excitation pulse and a comparison of the free induction decay (FID) with the integral of the FID combined with a shifting reconstruction window. The TQ signal is calculated from this FID only. As a proof of concept, the method was also combined with a multi-echo UTE imaging sequence on a 9.4 T preclinical MRI scanner for the possibility of fast TQ MRI. RESULTS The extracted Sodium TQ signals of single-pulse and spin echo FIDs were in close agreement with theory and TQ measurement by traditional three-pulse sequence (TQ time proportional phase increment [TQTPPI)]. For 2%, 4%, and 6% agar samples, the absolute deviations of the maximum TQ signals between SE and theoretical (time proportional phase increment TQTPPI) TQ signals were less than 1.2% (2.4%), and relative deviations were less than 4.6% (6.8%). The impact of multi-compartment systems and noise on the accuracy of the TQ signal was small for simulated data. The systematic error was <3.4% for a single quantum (SQ) SNR of 5 and at maximum <2.5% for a multi-compartment system. The method also showed the potential of fast in vivo SQ and TQ imaging. CONCLUSION Simultaneous SQ and TQ MRI using only a single-pulse sequence and SQ time efficiency has been demonstrated. This may leverage the full potential of the Sodium TQ signal in clinical applications.
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Affiliation(s)
- Simon Reichert
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
- Mannheim Institute for Intelligent Systems in Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
- Cooperative Core Facility Animal Scanner ZI, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Victor Schepkin
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida, USA
| | - Dennis Kleimaier
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Frank G Zöllner
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
- Mannheim Institute for Intelligent Systems in Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
- Cooperative Core Facility Animal Scanner ZI, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Lothar R Schad
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
- Mannheim Institute for Intelligent Systems in Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
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Reichert S, Schepkin V, Kleimaier D, Zöllner FG, Schad LR. Comparison of triple quantum (TQ) TPPI and inversion recovery TQ TPPI pulse sequences at 9.4 and 21.1 T. NMR IN BIOMEDICINE 2024; 37:e5106. [PMID: 38263738 DOI: 10.1002/nbm.5106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 12/04/2023] [Accepted: 12/27/2023] [Indexed: 01/25/2024]
Abstract
PURPOSE Both sodium T1 triple quantum (TQ) signal and T1 relaxation pathways have a unique sensitivity to the sodium molecular environment. In this study an inversion recovery time proportional phase increment (IRTQTPPI) pulse sequence was investigated for simultaneous and reliable quantification of sodium TQ signal and bi-exponential T1 relaxation times. METHODS The IRTQTPPI sequence combines inversion recovery TQ filtering and time proportional phase increment. The reliable and reproducible results were achieved by the pulse sequence optimized in three ways: (1) optimization of the nonlinear fit for the determination of both T1-TQ signal and T1 relaxation times; (2) suppression of unwanted signals by assessment of four different phase cycles; (3) nonlinear sampling during evolution time for optimal scan time without any compromises in fit accuracy. The relaxation times T1 and T2 and the TQ signals from IRTQTPPI and TQTPPI were compared between 9.4 and 21.1 T. The motional environment of the sodium nuclei was evaluated by calculation of correlation times and nuclear quadrupole interaction strengths. RESULTS Reliable measurements of the T1-TQ signals and T1 bi-exponential relaxation times were demonstrated. The fit parameters for all four phase cycles were in good agreement with one another, with a negligible influence of unwanted signals. The agar samples yielded normalized T1-TQ signals from 3% to 16% relative to single quantum (SQ) signals at magnetic fields of both 9.4 and 21.1 T. In comparison, the normalized T2-TQ signal was in the range 15%-35%. The TQ/SQ signal ratio was decreased at 21.1 T as compared with 9.4 T for both T1 and T2 relaxation pathways. The bi-exponential T1 relaxation time separation ranged from 15 to 18 ms at 9.4 T and 15 to 21 ms at 21.1 T. The T2 relaxation time separation was larger, ranging from 28 to 35 ms at 9.4 T and 37 to 40 ms at 21.1 T. CONCLUSION The IRTQTPPI sequence, while providing a less intensive TQ signal than TQTPPI, allows a simultaneous and reliable quantification of both the T1-TQ signal and T1 relaxation times. The unique sensitivities of the T1 and T2 relaxation pathways to different types of molecular motion provide a deeper understanding of the sodium MR environment.
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Affiliation(s)
- Simon Reichert
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany
- Mannheim Institute for Intelligent Systems in Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
- Cooperative Core Facility Animal Scanner ZI, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Victor Schepkin
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida, USA
| | - Dennis Kleimaier
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany
| | - Frank G Zöllner
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany
- Mannheim Institute for Intelligent Systems in Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
- Cooperative Core Facility Animal Scanner ZI, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Lothar R Schad
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Heidelberg, Germany
- Mannheim Institute for Intelligent Systems in Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
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Licht C, Reichert S, Guye M, Schad LR, Rapacchi S. Multidimensional compressed sensing to advance 23 Na multi-quantum coherences MRI. Magn Reson Med 2024; 91:926-941. [PMID: 37881829 DOI: 10.1002/mrm.29902] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2023] [Revised: 09/13/2023] [Accepted: 10/09/2023] [Indexed: 10/27/2023]
Abstract
PURPOSE Sodium (23 Na) multi-quantum coherences (MQC) MRI was accelerated using three-dimensional (3D) and a dedicated five-dimensional (5D) compressed sensing (CS) framework for simultaneous Cartesian single (SQ) and triple quantum (TQ) sodium imaging of in vivo human brain at 3.0 and 7.0 T. THEORY AND METHODS 3D 23 Na MQC MRI requires multi-echo paired with phase-cycling and exhibits thus a multidimensional space. A joint reconstruction framework to exploit the sparsity in all imaging dimensions by extending the conventional 3D CS framework to 5D was developed. 3D MQC images of simulated brain, phantom and healthy brain volunteers obtained from 3.0 T and 7.0 T were retrospectively and prospectively undersampled. Performance of the CS models were analyzed by means of structural similarity index (SSIM), root mean squared error (RMSE), signal-to-noise ratio (SNR) and signal quantification of tissue sodium concentration and TQ/SQ ratio. RESULTS It was shown that an acceleration of three-fold, leading to less than2 × 10 $$ 2\times 10 $$ min of scan time with a resolution of8 × 8 × 20 mm 3 $$ 8\times 8\times 20\;{\mathrm{mm}}^3 $$ at 3.0 T, are possible. 5D CS improved SSIM by 3%, 5%, 1% and reduced RMSE by 50%, 30%, 8% for in vivo SQ, TQ, and TQ/SQ ratio maps, respectively. Furthermore, for the first time prospective undersampling enabled unprecedented high resolution from8 × 8 × 20 mm 3 $$ 8\times 8\times 20\;{\mathrm{mm}}^3 $$ to6 × 6 × 10 mm 3 $$ 6\times 6\times 10\;{\mathrm{mm}}^3 $$ MQC images of in vivo human brain at 7.0 T without extending acquisition time. CONCLUSION 5D CS proved to allow up to three-fold acceleration retrospectively on 3.0 T data. 2-fold acceleration was demonstrated prospectively at 7.0 T to reach higher spatial resolution of 23 Na MQC MRI.
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Affiliation(s)
- Christian Licht
- Computer Assisted Clinical Medicine, Medical Faculty Mannhein, Heidelberg University, Mannheim, Germany
- Mannheim Institute for Intelligent System in Medicine, Medical Faculty Mannheim, Mannheim, Germany
| | - Simon Reichert
- Computer Assisted Clinical Medicine, Medical Faculty Mannhein, Heidelberg University, Mannheim, Germany
- Mannheim Institute for Intelligent System in Medicine, Medical Faculty Mannheim, Mannheim, Germany
| | - Maxime Guye
- Aix-Marseille Univ, CNRS, CRMBM, Marseille, France
- APHM, Hôpital Universitaire Timone, CEMEREM, Marseille, France
| | - Lothar R Schad
- Computer Assisted Clinical Medicine, Medical Faculty Mannhein, Heidelberg University, Mannheim, Germany
- Mannheim Institute for Intelligent System in Medicine, Medical Faculty Mannheim, Mannheim, Germany
| | - Stanislas Rapacchi
- Aix-Marseille Univ, CNRS, CRMBM, Marseille, France
- APHM, Hôpital Universitaire Timone, CEMEREM, Marseille, France
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With a grain of salt: Sodium elevation and metabolic remodelling in heart failure. J Mol Cell Cardiol 2021; 161:106-115. [PMID: 34371034 PMCID: PMC7611640 DOI: 10.1016/j.yjmcc.2021.08.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 07/09/2021] [Accepted: 08/03/2021] [Indexed: 12/14/2022]
Abstract
Elevated intracellular Na (Nai) and metabolic impairment are interrelated pathophysiological features of the failing heart (HF). There have been a number of studies showing that myocardial sodium elevation subtly affects mitochondrial function. During contraction, mitochondrial calcium (Camito) stimulates a variety of TCA cycle enzymes, thereby providing reducing equivalents to maintain ATP supply. Nai elevation has been shown to impact Camito; however, whether metabolic remodelling in HF is caused by increased Nai has only been recently demonstrated. This novel insight may help to elucidate the contribution of metabolic remodelling in the pathophysiology of HF, the lack of efficacy of current HF therapies and a rationale for the development of future metabolism-targeting treatments. Here we review the relationship between Na pump inhibition, elevated Nai, and altered metabolic profile in the context of HF and their link to metabolic (in)flexibility and mitochondrial reprogramming.
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Gerhalter T, Chen AM, Dehkharghani S, Peralta R, Adlparvar F, Babb JS, Bushnik T, Silver JM, Im BS, Wall SP, Brown R, Baete SH, Kirov II, Madelin G. Global decrease in brain sodium concentration after mild traumatic brain injury. Brain Commun 2021; 3:fcab051. [PMID: 33928248 PMCID: PMC8066885 DOI: 10.1093/braincomms/fcab051] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 01/27/2021] [Accepted: 02/22/2021] [Indexed: 11/28/2022] Open
Abstract
The pathological cascade of tissue damage in mild traumatic brain injury is set forth by a perturbation in ionic homeostasis. However, whether this class of injury can be detected in vivo and serve as a surrogate marker of clinical outcome is unknown. We employ sodium MRI to test the hypotheses that regional and global total sodium concentrations: (i) are higher in patients than in controls and (ii) correlate with clinical presentation and neuropsychological function. Given the novelty of sodium imaging in traumatic brain injury, effect sizes from (i), and correlation types and strength from (ii), were compared to those obtained using standard diffusion imaging metrics. Twenty-seven patients (20 female, age 35.9 ± 12.2 years) within 2 months after injury and 19 controls were scanned with proton and sodium MRI at 3 Tesla. Total sodium concentration, fractional anisotropy and apparent diffusion coefficient were obtained with voxel averaging across 12 grey and white matter regions. Linear regression was used to obtain global grey and white matter total sodium concentrations. Patient outcome was assessed with global functioning, symptom profiles and neuropsychological function assessments. In the regional analysis, there were no statistically significant differences between patients and controls in apparent diffusion coefficient, while differences in sodium concentration and fractional anisotropy were found only in single regions. However, for each of the 12 regions, sodium concentration effect sizes were uni-directional, due to lower mean sodium concentration in patients compared to controls. Consequently, linear regression analysis found statistically significant lower global grey and white matter sodium concentrations in patients compared to controls. The strongest correlation with outcome was between global grey matter sodium concentration and the composite z-score from the neuropsychological testing. In conclusion, both sodium concentration and diffusion showed poor utility in differentiating patients from controls, and weak correlations with clinical presentation, when using a region-based approach. In contrast, sodium linear regression, capitalizing on partial volume correction and high sensitivity to global changes, revealed high effect sizes and associations with patient outcome. This suggests that well-recognized sodium imbalances in traumatic brain injury are (i) detectable non-invasively; (ii) non-focal; (iii) occur even when the antecedent injury is clinically mild. Finally, in contrast to our principle hypothesis, patients' sodium concentrations were lower than controls, indicating that the biological effect of traumatic brain injury on the sodium homeostasis may differ from that in other neurological disorders. Note: This figure has been annotated.
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Affiliation(s)
- Teresa Gerhalter
- Department of Radiology, Center for Biomedical Imaging, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Anna M Chen
- Department of Radiology, Center for Biomedical Imaging, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Seena Dehkharghani
- Department of Radiology, Center for Biomedical Imaging, New York University Grossman School of Medicine, New York, NY 10016, USA
- Department of Neurology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Rosemary Peralta
- Department of Radiology, Center for Biomedical Imaging, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Fatemeh Adlparvar
- Department of Radiology, Center for Biomedical Imaging, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - James S Babb
- Department of Radiology, Center for Biomedical Imaging, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Tamara Bushnik
- Department of Rehabilitation Medicine, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Jonathan M Silver
- Department of Psychiatry, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Brian S Im
- Department of Rehabilitation Medicine, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Stephen P Wall
- Ronald O. Perelman Department of Emergency Medicine, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Ryan Brown
- Department of Radiology, Center for Biomedical Imaging, New York University Grossman School of Medicine, New York, NY 10016, USA
- Department of Radiology, Center for Advanced Imaging Innovation and Research, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Steven H Baete
- Department of Radiology, Center for Biomedical Imaging, New York University Grossman School of Medicine, New York, NY 10016, USA
- Department of Radiology, Center for Advanced Imaging Innovation and Research, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Ivan I Kirov
- Department of Radiology, Center for Biomedical Imaging, New York University Grossman School of Medicine, New York, NY 10016, USA
- Department of Neurology, New York University Grossman School of Medicine, New York, NY 10016, USA
- Department of Radiology, Center for Advanced Imaging Innovation and Research, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Guillaume Madelin
- Department of Radiology, Center for Biomedical Imaging, New York University Grossman School of Medicine, New York, NY 10016, USA
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Gerhalter T, Marty B, Gast LV, Porzelt K, Heiss R, Uder M, Schwab S, Carlier PG, Nagel AM, Türk M. Quantitative 1H and 23Na muscle MRI in Facioscapulohumeral muscular dystrophy patients. J Neurol 2020; 268:1076-1087. [PMID: 33047224 PMCID: PMC7914168 DOI: 10.1007/s00415-020-10254-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 09/29/2020] [Accepted: 10/01/2020] [Indexed: 12/11/2022]
Abstract
Objective Our aim was to assess the role of quantitative 1H and 23Na MRI methods in providing imaging biomarkers of disease activity and severity in patients with Facioscapulohumeral muscular dystrophy (FSHD). Methods We imaged the lower leg muscles of 19 FSHD patients and 12 controls with a multimodal MRI protocol to obtain STIR-T2w images, fat fraction (FF), water T2 (wT2), water T1 (wT1), tissue sodium concentration (TSC), and intracellular-weighted sodium signal (inversion recovery (IR) and triple quantum filter (TQF) sequence). In addition, the FSHD patients underwent muscle strength testing. Results Imaging biomarkers related with water mobility (wT1 and wT2) and ion homeostasis (TSC, IR, TQF) were increased in muscles of FSHD patients. Muscle groups with FF > 10% had higher wT2, wT1, TSC, IR, and TQF values than muscles with FF < 10%. Muscles with FF < 10% resembled muscles of healthy controls for these MRI disease activity measures. However, wT1 was increased in few muscles without fat replacement. Furthermore, few STIR-negative muscles (n = 11/76) exhibited increased wT1, TSC, IR or TQF. Increased wT1 as well as 23Na signals were also present in muscles with normal wT2. Muscle strength was related to the mean FF and all imaging biomarkers of tibialis anterior except wT2 were correlated with dorsal flexion. Conclusion The newly evaluated imaging biomarkers related with water mobility (wT1) and ion homeostasis (TSC, IR, TQF) showed different patterns compared to the established markers like FF in muscles of FSHD patients. These quantitative biomarkers could thus contain valuable complementary information for the early characterization of disease progression. Electronic supplementary material The online version of this article (10.1007/s00415-020-10254-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Teresa Gerhalter
- Institute of Radiology, University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nuremberg (FAU), Maximiliansplatz 3, 91054, Erlangen, Germany.
| | - Benjamin Marty
- NMR Laboratory, Institute of Myology, Paris, France
- NMR Laboratory, CEA/DRF, IBFJ/MIRCen, Paris, France
| | - Lena V Gast
- Institute of Radiology, University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nuremberg (FAU), Maximiliansplatz 3, 91054, Erlangen, Germany
- Institute of Medical Physics, Friedrich-Alexander University Erlangen-Nuremberg (FAU), Erlangen, Germany
| | - Katharina Porzelt
- Department of Neurology, Friedrich-Alexander University Erlangen-Nuremberg (FAU), Erlangen, Germany
| | - Rafael Heiss
- Institute of Radiology, University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nuremberg (FAU), Maximiliansplatz 3, 91054, Erlangen, Germany
| | - Michael Uder
- Institute of Radiology, University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nuremberg (FAU), Maximiliansplatz 3, 91054, Erlangen, Germany
| | - Stefan Schwab
- Department of Neurology, Friedrich-Alexander University Erlangen-Nuremberg (FAU), Erlangen, Germany
| | - Pierre G Carlier
- NMR Laboratory, Institute of Myology, Paris, France
- NMR Laboratory, CEA/DRF, IBFJ/MIRCen, Paris, France
| | - Armin M Nagel
- Institute of Radiology, University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nuremberg (FAU), Maximiliansplatz 3, 91054, Erlangen, Germany
- Division of Medical Physics in Radiology, German Cancer Research Centre, Heidelberg, Germany
- Institute of Medical Physics, Friedrich-Alexander University Erlangen-Nuremberg (FAU), Erlangen, Germany
| | - Matthias Türk
- Department of Neurology, Friedrich-Alexander University Erlangen-Nuremberg (FAU), Erlangen, Germany
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Intracellular Sodium Changes in Cancer Cells Using a Microcavity Array-Based Bioreactor System and Sodium Triple-Quantum MR Signal. Processes (Basel) 2020. [DOI: 10.3390/pr8101267] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The sodium triple-quantum (TQ) magnetic resonance (MR) signal created by interactions of sodium ions with macromolecules has been demonstrated to be a valuable biomarker for cell viability. The aim of this study was to monitor a cellular response using the sodium TQ signal during inhibition of Na/K-ATPase in living cancer cells (HepG2). The cells were dynamically investigated after exposure to 1 mM ouabain or K+-free medium for 60 min using an MR-compatible bioreactor system. An improved TQ time proportional phase incrementation (TQTPPI) pulse sequence with almost four times TQ signal-to-noise ratio (SNR) gain allowed for conducting experiments with 12–14 × 106 cells using a 9.4 T MR scanner. During cell intervention experiments, the sodium TQ signal increased to 138.9 ± 4.1% and 183.4 ± 8.9% for 1 mM ouabain (n = 3) and K+-free medium (n = 3), respectively. During reperfusion with normal medium, the sodium TQ signal further increased to 169.2 ± 5.3% for the ouabain experiment, while it recovered to 128.5 ± 6.8% for the K+-free experiment. These sodium TQ signal increases agree with an influx of sodium ions during Na/K-ATPase inhibition and hence a reduced cell viability. The improved TQ signal detection combined with this MR-compatible bioreactor system provides a capability to investigate the cellular response of a variety of cells using the sodium TQ MR signal.
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Kleimaier D, Schepkin V, Hu R, Schad LR. Protein conformational changes affect the sodium triple-quantum MR signal. NMR IN BIOMEDICINE 2020; 33:e4367. [PMID: 32656956 DOI: 10.1002/nbm.4367] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 06/10/2020] [Accepted: 06/15/2020] [Indexed: 06/11/2023]
Abstract
The aim of this study was to investigate possible sodium triple-quantum (TQ) signal dependence on pH variation and protein unfolding which may happen in vivo. The model system, composed of bovine serum albumin (BSA), was investigated over a wide pH range of 0.70 to 13.05 and during urea-induced unfolding. In both experimental series, the sodium and BSA concentration were kept constant so that TQ signal changes solely arose from an environmental change. The experiments were performed using unique potential to detect weak TQ signals by implementing a TQ time proportional phase increment pulse sequence. At a pH of 0.70, in which case the effect of the negatively charged groups was minimized, the minimum TQ percentage relative to single-quantum of 1.34% ± 0.05% was found. An increase of the pH up to 13.05 resulted in an increase of the sodium TQ signal by 225%. Urea-induced unfolding of BSA, without changes in pH, led to a smaller increase in the sodium TQ signal of up to 40%. The state of BSA unfolding was verified by fluorescence microscopy. Results of both experiments were well fitted by sigmoid functions. Both TQ signal increases were in agreement with an increase of the availability of negatively charged groups. The results point to vital contributions of the biochemical environment to the TQ MR signals. The sodium TQ signal in vivo could be a valuable biomarker of cell viability, and therefore possible effects of pH and protein unfolding need to be considered for a proper interpretation of changes in sodium TQ signals.
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Affiliation(s)
- Dennis Kleimaier
- Computer Assisted Clinical Medicine, Heidelberg University, Mannheim, Germany
| | - Victor Schepkin
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, USA
| | - Ruomin Hu
- Computer Assisted Clinical Medicine, Heidelberg University, Mannheim, Germany
| | - Lothar R Schad
- Computer Assisted Clinical Medicine, Heidelberg University, Mannheim, Germany
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Wilferth T, Gast LV, Stobbe RW, Beaulieu C, Hensel B, Uder M, Nagel AM. 23Na MRI of human skeletal muscle using long inversion recovery pulses. Magn Reson Imaging 2019; 63:280-290. [PMID: 31425815 DOI: 10.1016/j.mri.2019.08.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 07/05/2019] [Accepted: 08/15/2019] [Indexed: 12/20/2022]
Abstract
23Na inversion recovery (IR) imaging allows for a weighting toward intracellular sodium in the human calf muscle and thus enables an improved analysis of pathophysiological changes of the muscular ion homeostasis. However, sodium signal-to-noise ratio (SNR) is low, especially when using IR sequences. 23Na has a nuclear spin of 3/2 and therefore experiences a strong electrical quadrupolar interaction. This results in very short relaxation times as well as in possible residual quadrupolar splitting. Consequently, relaxation effects during a radiofrequency pulse can no longer be neglected and even allow for increasing SNR as has previously been shown for human brain and knee. The aim of this work was to increase the SNR in 23Na IR imaging of the human calf muscle by using long inversion pulses instead of the usually applied short pulses. First, the influence of the inversion pulse length (1 to 20 ms) on the SNR as well as on image contrast was simulated for different model environments and verified by phantom measurements. Depending on the model environment (agarose 4% and 8%, xanthan 2% and 3%), SNR values increased by a factor of 1.15 up to 1.35, while NaCl solution was successfully suppressed. Thus, image contrast between the non-suppressed model compartments changes with IR pulse length. Finally, in vivo measurements of the human calf muscle of ten healthy volunteers were conducted at 3 Tesla. On average, a 1.4-fold increase in SNR could be achieved by increasing the inversion pulse length from 1 ms to 20 ms, leaving all other parameters - including the scan time - constant. This enables 23Na IR MRI with improved spatial resolution or reduced acquisition time.
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Affiliation(s)
- Tobias Wilferth
- Institute of Radiology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany.
| | - Lena V Gast
- Institute of Radiology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Robert W Stobbe
- Department of Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada
| | - Christian Beaulieu
- Department of Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada
| | - Bernhard Hensel
- Center for Medical Physics and Engineering, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Michael Uder
- Institute of Radiology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Armin M Nagel
- Institute of Radiology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany; Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany; Institute of Medical Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
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11
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Schepkin VD. Statistical tensor analysis of the MQ MR signals generated by weak quadrupole interactions. Z Med Phys 2019; 29:326-336. [PMID: 31160139 DOI: 10.1016/j.zemedi.2019.03.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 02/02/2019] [Accepted: 03/27/2019] [Indexed: 11/16/2022]
Abstract
Multiple quantum NMR signals that appear in the presence of weak quadrupole interactions were formulated using statistical tensors (Fano, 1957). The approach aimed to present a concise and a computer-based tool for a detailed analysis and modification of the MQ pulse sequences. The calculation avoids a lengthy procedure of utilizing exponential operators and, moreover, the same formulae are applicable for any interval in the TQ pulse sequence, as well as any spin value. The quantum operator algebra was implemented using "Mathematica" software (Wolfram Inc.). The results of tensor's evolutions in the TQ pulse sequence were graphically illustrated using corresponding spherical harmonics. The visualization takes into consideration the parity properties of irreducible tensors and the corresponding spherical harmonics.
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Affiliation(s)
- Victor D Schepkin
- CIMAR, National High Magnetic Field Laboratory/FSU, Tallahassee, FL, USA.
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12
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Hoesl MAU, Kleimaier D, Hu R, Malzacher M, Nies C, Gottwald E, Schad LR. 23 Na Triple-quantum signal of in vitro human liver cells, liposomes, and nanoparticles: Cell viability assessment vs. separation of intra- and extracellular signal. J Magn Reson Imaging 2019; 50:435-444. [PMID: 30681221 DOI: 10.1002/jmri.26666] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 01/10/2019] [Accepted: 01/10/2019] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND Triple-quantum (TQ) filtered sequences have become more popular in sodium MR due to the increased usage of scanners with field strengths exceeding 3T. Disagreement as to whether TQ signal can provide separation of intra- and extracellular compartments persists. PURPOSE To provide insight into TQ signal behavior on a cellular level. STUDY TYPE Prospective. PHANTOM/SPECIMEN Cell-phantoms in the form of liposomes, encapsulated 0 mM, 145 mM, 154 mM Na+ in a double-lipid membrane similar to cells. Poly(lactic-co-glycolic acid) nanoparticles encapsulated 154 mM Na+ within a single-layer membrane structure. Two microcavity chips with each 6 × 106 human HEP G2 liver cells were measured in an MR-compatible bioreactor. FIELD STRENGTH/SEQUENCE Spectroscopic TQ sequence with time proportional phase-increments at 9.4T. ASSESSMENT The TQ signal of viable, dead cells, and cell-phantoms was assessed by a fit in the time domain and by the amplitude in the frequency domain. STATISTICAL TESTS The noise variance (σ) was evaluated to express the deviation of the measured TQ signal amplitude from noise. RESULTS TQ signal >20σ was found for liposomes encapsulating sodium ions. Liposomal encapsulation of 0 mM Na+ and 154 mM Na+ encapsulation in the nanoparticles resulted in <2σ TQ signal. Cells under normal perfusion resulted in >9σ TQ signal. Compared with TQ signal under normal perfusion, a 56% lower TQ signal of was observed (25σ) during perfusion stop. TQ signal returned to 92% of the initial signal after reperfusion. DATA CONCLUSION Our measurements indicate that TQ signal in liposomes was observed due to the trapping of ions within the double-lipid membrane rather than from the intraliposomal space. Transfer to the cell results suggests that TQ signal was observed from motion restriction equivalent to trapping. LEVEL OF EVIDENCE 1 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2019;50:435-444.
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Affiliation(s)
- Michaela A U Hoesl
- Computer Assisted Clinical Medicine, Heidelberg University, Mannheim, Germany
| | - Dennis Kleimaier
- Computer Assisted Clinical Medicine, Heidelberg University, Mannheim, Germany
| | - Ruomin Hu
- Computer Assisted Clinical Medicine, Heidelberg University, Mannheim, Germany
| | - Matthias Malzacher
- Computer Assisted Clinical Medicine, Heidelberg University, Mannheim, Germany
| | - Cordula Nies
- Institute of Functional Interfaces, Karlsruhe Institute of Technology, Karlsruhe, Germany
| | - Eric Gottwald
- Institute of Functional Interfaces, Karlsruhe Institute of Technology, Karlsruhe, Germany
| | - Lothar R Schad
- Computer Assisted Clinical Medicine, Heidelberg University, Mannheim, Germany
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13
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Gast LV, Gerhalter T, Hensel B, Uder M, Nagel AM. Double quantum filtered 23 Na MRI with magic angle excitation of human skeletal muscle in the presence of B 0 and B 1 inhomogeneities. NMR IN BIOMEDICINE 2018; 31:e4010. [PMID: 30290039 DOI: 10.1002/nbm.4010] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 07/19/2018] [Accepted: 07/31/2018] [Indexed: 06/08/2023]
Abstract
Double quantum filtered 23 Na MRI with magic angle excitation (DQF-MA) can be used to selectively detect sodium ions located within anisotropic structures such as muscle fibers. It might therefore be a promising tool to analyze the microscopic environment of sodium ions, for example in the context of osmotically neutral sodium retention. However, DQF-MA imaging is challenging due to various signal dependences, on both measurement parameters and external influences. The aim of this work was to examine how B0 in combination with B1 inhomogeneities alter the DQF-MA signal intensity. We showed that, in the presence of B0 inhomogeneities, flip angle schemes with only one 54.7° pulse can be favorable compared with the classical 90°-54.7°-54.7° scheme. DQF-MA images of the human lower leg were acquired at B0 = 3 T with a nominal spatial resolution of 12 × 12 × 36 mm3 within an acquisition time of TAcq < 10 min, and compared with spin density weighted (DW), as well as triple quantum filtration (TQF) 23 Na images. We found mean normalized signal-to-noise ratios of TQF/DW = 13.7 ± 2.3% (tibialis anterior), 11.9 ± 2.3% (soleus) and 11.4 ± 2.2% (gastrocnemius medialis), as well as DQF-MA/DW = 4.7 ± 1.1% (tibialis anterior), 3.3 ± 0.73% (soleus) and 3.4 ± 0.6% (gastrocnemius medialis). These ratios might serve as additional measures in future clinical studies of sodium retention within human skeletal muscle. However, the influence of B0 and B1 inhomogeneities should be considered when interpreting DQF-MA images.
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Affiliation(s)
- Lena V Gast
- Institute of Radiology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Teresa Gerhalter
- Institute of Radiology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
- NMR laboratory, Neuromuscular Investigation Center, Institute of Myology, Paris, France
- NMR laboratory, CEA/IBFJ/MIRCen, Paris, France
| | - Bernhard Hensel
- Center for Medical Physics and Engineering, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Michael Uder
- Institute of Radiology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Armin M Nagel
- Institute of Radiology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
- Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Institute of Medical Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
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14
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Is there a causal link between intracellular Na elevation and metabolic remodelling in cardiac hypertrophy? Biochem Soc Trans 2018; 46:817-827. [PMID: 29970448 PMCID: PMC6103460 DOI: 10.1042/bst20170508] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Revised: 05/23/2018] [Accepted: 05/24/2018] [Indexed: 01/23/2023]
Abstract
Alterations in excitation–contraction coupling and elevated intracellular sodium (Nai) are hallmarks of pathological cardiac remodelling that underline contractile dysfunction. In addition, changes in cardiac metabolism are observed in cardiac hypertrophy and heart failure (HF) that lead to a mismatch in ATP supply and demand, contributing to poor prognosis. A link between Nai and altered metabolism has been proposed but is not well understood. Many mitochondrial enzymes are stimulated by mitochondrial calcium (Camito) during contraction, thereby sustaining production of reducing equivalents to maintain ATP supply. This stimulation is thought to be perturbed when cytosolic Nai is high due to increased Camito efflux, potentially compromising ATPmito production and leading to metabolic dysregulation. Increased Nai has been previously shown to affect Camito; however, whether Nai elevation plays a causative role in energetic mismatching in the hypertrophied and failing heart remains unknown. In this review, we discuss the relationship between elevated Nai, NaK ATPase dysregulation and the metabolic phenotype in the contexts of pathological hypertrophy and HF and their link to metabolic flexibility, capacity (reserve) and efficiency that are governed by intracellular ion homeostasis. The development of non-invasive analytical techniques using nuclear magnetic resonance able to probe metabolism in situ in the functioning heart will enable a better understanding of the underlying mechanisms of Nai overload in cardiac pathophysiology. They will lead to novel insights that help to explain the metabolic contribution towards these diseases, the incomplete rescue observed with current therapies and a rationale for future energy-targeted therapies.
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15
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Gerhalter T, Carlier PG, Marty B. Acute changes in extracellular volume fraction in skeletal muscle monitored by 23Na NMR spectroscopy. Physiol Rep 2018; 5:5/16/e13380. [PMID: 28867674 PMCID: PMC5582265 DOI: 10.14814/phy2.13380] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Revised: 06/20/2017] [Accepted: 07/14/2017] [Indexed: 11/24/2022] Open
Abstract
In this article, we induced acute changes in extracellular volume fraction in skeletal muscle tissue and compared the sensitivity of a standard 1H T2 imaging method with different 23Na‐NMR spectroscopy parameters within acquisition times compatible with clinical investigations. First, we analyzed the effect of a short ischemia on the sodium distribution in the skeletal muscle. Then, the lower leg of 21 healthy volunteers was scanned under different vascular filling conditions (vascular draining, filling, and normal condition) expected to modify exclusively the extracellular volume. The first experiment showed no change in the total sodium content during a 15 min ischemia, but the intracellular weighted 23Na signal slowly decreased. For the second part, significant variations of total sodium content, sodium distribution, and T1 and T2∗ of 23Na signal were observed between different vascular filling conditions. The measured sodium distribution correlates significantly with sodium T1 and with the short and long T2∗ fractions. In contrast, significant changes in the proton T2w signal were observed only in three muscles. Altogether, the mean T2w signal intensity of all muscles as well as their mean T2 did not vary significantly with the extracellular volume changes. In conclusion, at the expense of giving up spatial resolution, the proposed 23Na spectroscopic method proved to be more sensitive than standard 1H T2 approach to monitor acute extracellular compartment changes within muscle tissue.
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Affiliation(s)
- Teresa Gerhalter
- Institute of Myology, NMR Laboratory, Paris, France .,CEA, DRF, IBFJ, MIRCen, NMR Laboratory, Paris, France
| | - Pierre G Carlier
- Institute of Myology, NMR Laboratory, Paris, France.,CEA, DRF, IBFJ, MIRCen, NMR Laboratory, Paris, France
| | - Benjamin Marty
- Institute of Myology, NMR Laboratory, Paris, France.,CEA, DRF, IBFJ, MIRCen, NMR Laboratory, Paris, France
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16
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Budinger TF, Bird MD. MRI and MRS of the human brain at magnetic fields of 14 T to 20 T: Technical feasibility, safety, and neuroscience horizons. Neuroimage 2018; 168:509-531. [DOI: 10.1016/j.neuroimage.2017.01.067] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Revised: 01/23/2017] [Accepted: 01/27/2017] [Indexed: 11/16/2022] Open
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17
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Neubauer A, Nies C, Schepkin VD, Hu R, Malzacher M, Chacón-Caldera J, Thiele D, Gottwald E, Schad LR. Tracking protein function with sodium multi quantum spectroscopy in a 3D-tissue culture based on microcavity arrays. Sci Rep 2017. [PMID: 28638107 PMCID: PMC5479864 DOI: 10.1038/s41598-017-04226-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The aim of this study was to observe the effects of strophanthin induced inhibition of the Na-/K-ATPase in liver cells using a magnetic resonance (MR) compatible bioreactor. A microcavity array with a high density three-dimensional cell culture served as a functional magnetic resonance imaging (MRI) phantom for sodium multi quantum (MQ) spectroscopy. Direct contrast enhanced (DCE) MRI revealed the homogenous distribution of biochemical substances inside the bioreactor. NMR experiments using advanced bioreactors have advantages with respect to having full control over a variety of physiological parameters such as temperature, gas composition and fluid flow. Simultaneous detection of single quantum (SQ) and triple quantum (TQ) MR signals improves accuracy and was achieved by application of a pulse sequence with a time proportional phase increment (TQTPPI). The time course of the Na-/K-ATPase inhibition in the cell culture was demonstrated by the corresponding alterations of sodium TQ/SQ MR signals.
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Affiliation(s)
- Andreas Neubauer
- Computer Assisted Clinical Medicine, Centre for Biomedicine and Medical Technology Mannheim, Heidelberg University, Mannheim, Germany.
| | - Cordula Nies
- Institute of Functional Interfaces, Karlsruhe Institute of Technology, Karlsruhe, Germany
| | - Victor D Schepkin
- CIMAR, National High Magnetic Field Laboratory/FSU, Tallahassee, FL, USA
| | - Ruomin Hu
- Computer Assisted Clinical Medicine, Centre for Biomedicine and Medical Technology Mannheim, Heidelberg University, Mannheim, Germany
| | - Matthias Malzacher
- Computer Assisted Clinical Medicine, Centre for Biomedicine and Medical Technology Mannheim, Heidelberg University, Mannheim, Germany
| | - Jorge Chacón-Caldera
- Computer Assisted Clinical Medicine, Centre for Biomedicine and Medical Technology Mannheim, Heidelberg University, Mannheim, Germany
| | - David Thiele
- Institute for Biological Interfaces-5, Karlsruhe Institute of Technology, Karlsruhe, Germany
| | - Eric Gottwald
- Institute of Functional Interfaces, Karlsruhe Institute of Technology, Karlsruhe, Germany
| | - Lothar R Schad
- Computer Assisted Clinical Medicine, Centre for Biomedicine and Medical Technology Mannheim, Heidelberg University, Mannheim, Germany
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18
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Schepkin VD, Neubauer A, Nagel AM, Budinger TF. Comparison of potassium and sodium binding in vivo and in agarose samples using TQTPPI pulse sequence. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2017; 277:162-168. [PMID: 28314206 DOI: 10.1016/j.jmr.2017.03.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 02/27/2017] [Accepted: 03/03/2017] [Indexed: 06/06/2023]
Abstract
Potassium and sodium specific binding in vivo were explored at 21.1T by triple quantum (TQ) magnetic resonance (MR) signals without filtration to achieve high sensitivities and precise quantifications. The pulse sequence used time proportional phase increments (TPPI). During simultaneous phase-time increments, it provided total single quantum (SQ) and TQ MR signals in the second dimension at single and triple quantum frequencies, respectively. The detection of both TQ and SQ signals was performed at identical experimental conditions and the resulting TQ signal equals 60±3% of the SQ signal when all ions experience sufficient time for binding. In a rat head in vivo the TQ percentage relative to SQ for potassium is 41.5±3% and for sodium is 16.1±1%. These percentages were compared to the matching values in an agarose tissue model with MR relaxation times similar to those of mammalian brain tissue. The sodium TQ signal in agarose samples decreased in the presence of potassium, suggesting a competitive binding of potassium relative to sodium ions for the same binding sites. The TQTPPI signals correspond to almost two times more effective binding of potassium than sodium. In vivo, up to ∼69% of total potassium and ∼27% of total sodium can be regarded as bound or experiencing an association time in the range of several milliseconds. Experimental data analyses show that more than half of the in vivo total sodium TQ signal could be from extracellular space, which is an important factor for quantification of intracellular MR signals.
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Affiliation(s)
- Victor D Schepkin
- CIMAR, National High Magnetic Field Laboratory/FSU, Tallahassee, FL, USA.
| | - Andreas Neubauer
- Computer Assisted Clinical Medicine/CBTM, Heidelberg University, Mannheim, Germany
| | - Armin M Nagel
- German Cancer Research Center (DKFZ), Division of Medical Physics in Radiology, Heidelberg, Germany; Institute of Radiology, University Hospital Erlangen, Erlangen, Germany
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19
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Budinger TF, Bird MD, Frydman L, Long JR, Mareci TH, Rooney WD, Rosen B, Schenck JF, Schepkin VD, Sherry AD, Sodickson DK, Springer CS, Thulborn KR, Uğurbil K, Wald LL. Toward 20 T magnetic resonance for human brain studies: opportunities for discovery and neuroscience rationale. MAGMA (NEW YORK, N.Y.) 2016; 29:617-39. [PMID: 27194154 PMCID: PMC5538368 DOI: 10.1007/s10334-016-0561-4] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Revised: 04/06/2016] [Accepted: 04/11/2016] [Indexed: 12/16/2022]
Abstract
An initiative to design and build magnetic resonance imaging (MRI) and spectroscopy (MRS) instruments at 14 T and beyond to 20 T has been underway since 2012. This initiative has been supported by 22 interested participants from the USA and Europe, of which 15 are authors of this review. Advances in high temperature superconductor materials, advances in cryocooling engineering, prospects for non-persistent mode stable magnets, and experiences gained from large-bore, high-field magnet engineering for the nuclear fusion endeavors support the feasibility of a human brain MRI and MRS system with 1 ppm homogeneity over at least a 16-cm diameter volume and a bore size of 68 cm. Twelve neuroscience opportunities are presented as well as an analysis of the biophysical and physiological effects to be investigated before exposing human subjects to the high fields of 14 T and beyond.
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Affiliation(s)
- Thomas F Budinger
- Lawrence Berkeley National Laboratory, University of California, Berkeley, CA, USA.
| | - Mark D Bird
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, USA
| | - Lucio Frydman
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, USA
- Weizmann Institute, Rehovot, Israel
| | - Joanna R Long
- McKnight Brain Institute, University of Florida, Gainesville, FL, USA
| | - Thomas H Mareci
- McKnight Brain Institute, University of Florida, Gainesville, FL, USA
| | | | - Bruce Rosen
- Massachusetts General Hospital, Harvard Medical School, Harvard, MA, USA
| | - John F Schenck
- General Electric Corporate Research, Schenectady, NY, USA
| | - Victor D Schepkin
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, USA
| | - A Dean Sherry
- University of Texas Southwestern Medical Center, Dallas, TX, USA
| | | | | | | | | | - Lawrence L Wald
- Massachusetts General Hospital, Harvard Medical School, Harvard, MA, USA
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20
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Eykyn TR, Aksentijević D, Aughton KL, Southworth R, Fuller W, Shattock MJ. Multiple quantum filtered (23)Na NMR in the Langendorff perfused mouse heart: Ratio of triple/double quantum filtered signals correlates with [Na]i. J Mol Cell Cardiol 2015. [PMID: 26196304 PMCID: PMC4564289 DOI: 10.1016/j.yjmcc.2015.07.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
We investigate the potential of multiple quantum filtered (MQF) 23Na NMR to probe intracellular [Na]i in the Langendorff perfused mouse heart. In the presence of Tm(DOTP) shift reagent the triple quantum filtered (TQF) signal originated largely from the intracellular sodium pool with a 32 ± 6% contribution of the total TQF signal arising from extracellular sodium, whilst the rank 2 double-quantum filtered signal (DQF), acquired with a 54.7° flip-angle pulse, originated exclusively from the extracellular sodium pool. Given the different cellular origins of the 23Na MQF signals we propose that the TQF/DQF ratio can be used as a semi-quantitative measure of [Na]i in the mouse heart. We demonstrate a good correlation of this ratio with [Na]i measured with shift reagent at baseline and under conditions of elevated [Na]i. We compare the measurements of [Na]i using both shift reagent and TQF/DQF ratio in a cohort of wild type mouse hearts and in a transgenic PLM3SA mouse expressing a non-phosphorylatable form of phospholemman, showing a modest but measurable elevation of baseline [Na]i. MQF filtered 23Na NMR is a potentially useful tool for studying normal and pathophysiological changes in [Na]i, particularly in transgenic mouse models with altered Na regulation. Intracellular Na concentration [Na]i is a key modulator of cardiac cell function. We developed an NMR-compatible Langendorff mouse heart perfusion system. The ratio of triple/double quantum filtered 23Na NMR signals correlates with [Na]i. Intracellular [Na]i can be quantified under physiological perfusion conditions. The PLM3SA transgenic mouse model has a measurable elevation of [Na]i at baseline.
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Affiliation(s)
- Thomas R Eykyn
- Department of Imaging Chemistry and Biology, Division of Imaging Sciences and Biomedical Engineering, King's College London, King's Health Partners, St. Thomas' Hospital, London SE1 7EH, United Kingdom; The British Heart Foundation Centre of Research Excellence, The Rayne Institute, King's College London, St. Thomas' Hospital, London SE1 7EH, United Kingdom.
| | - Dunja Aksentijević
- The British Heart Foundation Centre of Research Excellence, The Rayne Institute, King's College London, St. Thomas' Hospital, London SE1 7EH, United Kingdom
| | - Karen L Aughton
- The British Heart Foundation Centre of Research Excellence, The Rayne Institute, King's College London, St. Thomas' Hospital, London SE1 7EH, United Kingdom
| | - Richard Southworth
- Department of Imaging Chemistry and Biology, Division of Imaging Sciences and Biomedical Engineering, King's College London, King's Health Partners, St. Thomas' Hospital, London SE1 7EH, United Kingdom; The British Heart Foundation Centre of Research Excellence, The Rayne Institute, King's College London, St. Thomas' Hospital, London SE1 7EH, United Kingdom
| | - William Fuller
- Division of Cardiovascular and Diabetes Medicine, University of Dundee, Dundee, United Kingdom
| | - Michael J Shattock
- The British Heart Foundation Centre of Research Excellence, The Rayne Institute, King's College London, St. Thomas' Hospital, London SE1 7EH, United Kingdom
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21
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Madelin G, Lee JS, Regatte RR, Jerschow A. Sodium MRI: methods and applications. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2014; 79:14-47. [PMID: 24815363 PMCID: PMC4126172 DOI: 10.1016/j.pnmrs.2014.02.001] [Citation(s) in RCA: 148] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2014] [Accepted: 02/12/2014] [Indexed: 05/11/2023]
Abstract
Sodium NMR spectroscopy and MRI have become popular in recent years through the increased availability of high-field MRI scanners, advanced scanner hardware and improved methodology. Sodium MRI is being evaluated for stroke and tumor detection, for breast cancer studies, and for the assessment of osteoarthritis and muscle and kidney functions, to name just a few. In this article, we aim to present an up-to-date review of the theoretical background, the methodology, the challenges, limitations, and current and potential new applications of sodium MRI.
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Affiliation(s)
- Guillaume Madelin
- New York University Langone Medical Center, Department of Radiology, Center for Biomedical Imaging, New York, NY 10016, USA
| | - Jae-Seung Lee
- New York University Langone Medical Center, Department of Radiology, Center for Biomedical Imaging, New York, NY 10016, USA; Chemistry Department, New York University, 100 Washington Square East, New York, NY 10003, USA
| | - Ravinder R Regatte
- New York University Langone Medical Center, Department of Radiology, Center for Biomedical Imaging, New York, NY 10016, USA
| | - Alexej Jerschow
- Chemistry Department, New York University, 100 Washington Square East, New York, NY 10003, USA.
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22
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Konstandin S, Schad LR. 30 Years of sodium/X-nuclei magnetic resonance imaging. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2014; 27:1-4. [PMID: 24449020 DOI: 10.1007/s10334-013-0426-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Revised: 11/08/2013] [Accepted: 11/22/2013] [Indexed: 12/24/2022]
Abstract
In principle, all nuclei with nonzero spin can be employed for magnetic resonance imaging (MRI). Special scanner hardware and MR sequences are required to select the nucleus-specific frequency and to enable imaging with "sufficient" signal-to-noise ratio. This Special Issue starts with an overview of different nuclei that can be used for MRI today, followed by a review article about techniques required for imaging of quadrupolar nuclei with short relaxation times. Sequence developments to improve image quality and applications on different organs and diseases are presented for different nuclei ((23)Na, (35)Cl, (17)O, and (19)F), with a focus on imaging at natural abundance.
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Affiliation(s)
- Simon Konstandin
- Computer Assisted Clinical Medicine, Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany,
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Fonseca CP, Fonseca LL, Montezinho LP, Alves PM, Santos H, Castro MMCA, Geraldes CFGC. 23Na multiple quantum filtered NMR characterisation of Na+ binding and dynamics in animal cells: a comparative study and effect of Na+/Li+ competition. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2013; 42:503-19. [DOI: 10.1007/s00249-013-0899-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2013] [Revised: 03/07/2013] [Accepted: 03/21/2013] [Indexed: 10/27/2022]
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Bernsen MR, Ruggiero A, van Straten M, Kotek G, Haeck JC, Wielopolski PA, Krestin GP. Computed tomography and magnetic resonance imaging. Recent Results Cancer Res 2013. [PMID: 23179877 DOI: 10.1007/978-3-642-10853-2_1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Imaging in Oncology is rapidly moving from the detection and size measurement of a lesion to the quantitative assessment of metabolic processes and cellular and molecular interactions. Increasing insights into cancer as a complex disease with involvement of the tumor stroma in tumor pathobiological processes have made it clear that for successful control of cancer, treatment strategies should not only be directed at the tumor cells but also targeted at the tumor microenvironment. This requires understanding of the complex molecular and cellular interactions in cancer tissue. Recent developments in imaging technology have increased the possibility to image various pathobiological processes in cancer development and response to treatment. For computed tomography (CT) and magnetic resonance imaging (MRI) various improvements in hardware, software, and imaging probes have lifted these modalities from classical anatomical imaging techniques to techniques suitable to image and quantify various physiological processes and molecular and cellular interactions. Next to a more general overview of possible imaging targets in oncology this chapter provides an overview of the various developments in CT and MRI technology and some specific applications.
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Affiliation(s)
- Monique R Bernsen
- Department of Radiology, Erasmus MC-University Medical Center Rotterdam, Rotterdam, The Netherlands.
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Boada F, Laverde G, Jungreis C, Nemoto E, Tanase C. Triple/Single quantum filtered sodium MRI of acute brain ischemia. CONFERENCE PROCEEDINGS : ... ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL CONFERENCE 2012; 2006:731-4. [PMID: 17282287 DOI: 10.1109/iembs.2005.1616518] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The effectiveness of reperfusion therapies during acute brain ischemia depends on the viability of the underperfused tissue. Specifically, when the ischemic tissue is viable reperfusion leads to improved clinical outcome. However, when the ischemic tissue is non-viable, reperfusion therapy can lead to intra-cerebral hemorrhage and/or an accelerated rate of ischemia formation. Perfusion and diffusion weighted proton MRI (DW MRI) are well-established techniques for the early detection of brain ischemia but are unable to positively establish the viability of the tissue. Tissue sodium concentration (TSC) has been shown to exhibit a linear and reversible response for many hours after ischemia onset. Because sodium accumulation in tissue is closely related to its metabolic status, we believe that the rate of TSC accumulation during evolving ischemia could provide useful information about tissue viability during evolving ischemia. In this paper, we discuss the technical details leading to the application of triple quantum (TQ) sodium MRI for the monitoring of brain ischemia. The proposed methods are then demonstrated in a non-human primate model of temporary middle cerebral artery (MCA) occlusion.
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Affiliation(s)
- F Boada
- MR Research Center, Department of Radiology, University of Pittsburgh, Pittsburgh, PA, USA
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26
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Lee JS, Regatte RR, Jerschow A. Optimal control NMR differentiation between fast and slow sodium. Chem Phys Lett 2010. [DOI: 10.1016/j.cplett.2010.06.019] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Tanase C, Boada FE. Triple-quantum-filtered imaging of sodium in presence of B(0) inhomogeneities. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2005; 174:270-278. [PMID: 15862244 DOI: 10.1016/j.jmr.2005.02.012] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2004] [Revised: 02/08/2005] [Accepted: 02/09/2005] [Indexed: 05/24/2023]
Abstract
Triple quantum filtered sodium MRI techniques have been recently demonstrated in vivo. These techniques have been previously advocated as a means to separate the sodium NMR signal from different physiological compartments based on the differences between their relaxation rates. Among the different triple quantum coherence transfer filters, the three-pulse coherence transfer filter has been demonstrated to be better suited for human imaging than the traditional four-pulse implementation. While the three-pulse structure has distinct advantages in terms of RF efficiency, the lack of a refocusing pulse in the filter introduces an increased dependence on the main magnetic field inhomogeneities, which can sometimes lead to significant signal loss. In this paper, we characterize these dependencies and introduce a method for their compensation through the acquisition of a B(0) map and the use of a modified phase cycling scheme.
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Affiliation(s)
- Costin Tanase
- Department of Physics and Astronomy, University of Pittsburgh, 35905 O'Hara Street, Pittsburgh, PA 15213, USA.
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Forder JR, Pohost GM. Cardiovascular nuclear magnetic resonance: basic and clinical applications. J Clin Invest 2003. [DOI: 10.1172/jci200318868] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Forder JR, Pohost GM. Cardiovascular nuclear magnetic resonance: basic and clinical applications. J Clin Invest 2003; 111:1630-9. [PMID: 12782663 PMCID: PMC156119 DOI: 10.1172/jci18868] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Affiliation(s)
- John R Forder
- Division of Cardiovascular Medicine, Keck School of Medicine, The University of Southern California, Los Angeles, California 90033, USA
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Clayton DB, Lenkinski RE. MR imaging of sodium in the human brain with a fast three-dimensional gradient-recalled-echo sequence at 4 T. Acad Radiol 2003; 10:358-65. [PMID: 12678174 DOI: 10.1016/s1076-6332(03)80023-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
RATIONALE AND OBJECTIVES Sodium ions play a vital role in cellular homeostasis and electrochemical activity throughout the human body. However, the in vivo detection of sodium (23Na) with magnetic resonance (MR) techniques is hindered by the fast transverse relaxation, low tissue equivalent concentration, and small gyromagnetic ratio of sodium ions compared with protons (1H). The goals of this study were to acquire MR images of sodium in the whole human brain by using a fast three-dimensional gradient-recalled-echo sequence and to investigate the effect that restrictions on specific absorption ratio have on MR imaging of sodium at 4 T. MATERIALS AND METHODS A three-dimensional gradient-recalled-echo sequence with short echo time was developed for MR imaging of sodium. Slab encoding was removed and a hard excitation pulse was used. Five healthy human volunteers were examined in a whole-body MR imager with the use of a custom transmit-and-receive birdcage coil. Fields of view were selected to cover the entire brain: 38 x 38 cm in the axial plane, with 24 sections of 5.8 mm each or 12 sections of 1.1 cm each. The in-plane acquisition matrix was 64 x 128, and voxel size was 0.2 cm(3). RESULTS Sodium in white matter was depicted with an acceptable signal-to-noise ratio of 20-25. The echo time, and hence the signal-to-noise ratio, was limited by the MR imager's maximum allowable gradient strength. To keep the specific absorption ratio below 3 W/kg (the limit established by the Food and Drug Administration), it was necessary to prolong the repetition time to 30 msec. CONCLUSION The MR imaging protocol used in this study provided acceptable visualization of sodium in the whole brain in a tolerable total acquisition time of 15 minutes.
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Affiliation(s)
- David B Clayton
- Department of Radiology, University of Pennsylvania, Philadelphia, USA
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31
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Serrai H, Borthakur A, Senhadji L, Reddy R, Bansal N. Time-domain quantification of multiple-quantum-filtered (23)Na signal using continuous wavelet transform analysis. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2000; 142:341-347. [PMID: 10648152 DOI: 10.1006/jmre.1999.1947] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The application of continuous wavelet transform (CWT) analysis technique is presented to analyze multiple-quantum-filtered (MQF) (23)Na magnetic resonance spectroscopy (MRS) data. CWT acts on the free-induction-decay (FID) signal as a time-frequency variable filter. The signal-to-noise ratio (SNR) and frequency resolution of the output filter are locally increased. As a result, MQF equilibrium longitudinal magnetization and the apparent fast and slow transverse relaxation times are accurately estimated. A developed iterative algorithm based on frequency signal detection and components extraction, already proposed, was used to estimate the values of the signal parameters by analyzing simulated time-domain MQF signals and data from an agarose gel. The results obtained were compared to those obtained by measurement of signal height in frequency domain as a function of MQF preparation time and those obtained by a simple time-domain curve fitting. The comparison indicates that the CWT approach provides better results than the other tested methods that are generally used for MQF (23)Na MRS data analysis, especially when the SNR is low. The mean error on the estimated values of the amplitude signal and the apparent fast and slow transverse relaxation times for the simulated data were 2.19, 6. 63, and 16.17% for CWT, signal height in frequency domain, and time-domain curve fitting methods, respectively. Another major advantage of the proposed technique is that it allows quantification of MQF (23)Na signal from a single FID and, thus, reduces the experiment time dramatically.
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Affiliation(s)
- H Serrai
- Department of Radiology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104-6100, USA
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Schepkin VD, Choy IO, Budinger TF, Young JN, DeCampli WM. Multi-dose crystalloid cardioplegia preserves intracellular sodium homeostasis in myocardium. J Mol Cell Cardiol 1999; 31:1643-51. [PMID: 10471348 DOI: 10.1006/jmcc.1999.1002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The goal of this study was to assess the effect of multi-dose St Thomas' cardioplegia on intracellular sodium homeostasis in a rat heart model. A new magnetic resonance method was applied which enable us to detect intracellular Na changes without chemical shift reagents. Three groups of isolated rat hearts were subjected to 51 min of ischemia and 51 min of reperfusion at 37 degrees C: Group 1-three infusions of St Thomas' cardioplegia every 17 min for 2 min (n=7); Group 2-single-dose infusion of cardioplegia at the beginning of stop-flow ischemia (n=8); and Group 3-clamp ischemia (n=3) without cardioplegia administration. Performance of the heart was assessed by rate-pressure product relative to the pre-ischemic level (RPP). An NMR method was applied which continuously detects the Na(i) concentration in the heart, using the ability of bound sodium to exhibit triple-quantum transitions and the growth of the corresponding signal when sodium ions pass from extracellular to intracellular space. Clamp ischemia without cardioplegia and 50 min of reperfusion left the heart dysfunctional, with Na(i) growth from the pre-ischemic level of 13.9+/-1.2 mM to 34.9+/-1.3 mM and 73. 9+/-1.9 mM at the end of ischemia and reperfusion, respectively. During single-dose cardioplegia the corresponding values for Na(i) were 30.2+/-1 mM and 48.5+/-1.7 mM (RPP=29%). Multiple infusions of cardioplegic solution resulted in a remarkable preservation of the heart's intracellular Na concentration with a non-significant increase in Na(i) during ischemia and only 16.7+/-1 mM, (P=0.01), after subsequent reperfusion (RPP=85%). The time course of Na(i) changes in the rat heart model demonstrates a prominent potential of multi-dose St Thomas' cardioplegia in preserving intracellular sodium homeostasis at 37 degrees C. The growth of Na(i) concentration during ischemia, as an indicator of the viability of the myocytes, can have a prognostic value for the heart's performance during reperfusion.
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Affiliation(s)
- V D Schepkin
- Center for Functional Imaging, Lawrence Berkeley National Lab, Berkeley, CA, USA
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Srinivasan C, Minadeo N, Toon J, Graham D, Mota de Freitas D, Geraldes CF. Competition between Na(+) and Li(+) for unsealed and cytoskeleton-depleted human red blood cell membrane: a (23)Na multiple quantum filtered and (7)Li NMR relaxation study. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 1999; 140:206-217. [PMID: 10479564 DOI: 10.1006/jmre.1999.1813] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Evidence for competition between Li(+) and Na(+) for binding sites of human unsealed and cytoskeleton-depleted human red blood cell (csdRBC) membranes was obtained from the effect of added Li(+) upon the (23)Na double quantum filtered (DQF) and triple quantum filtered (TQF) NMR signals of Na(+)-containing red blood cell (RBC) membrane suspensions. We found that, at low ionic strength, the observed quenching effect of Li(+) on the (23)Na TQF and DQF signal intensity probed Li(+)/Na(+) competition for isotropic binding sites only. Membrane cytoskeleton depletion significantly decreased the isotropic signal intensity, strongly affecting the binding of Na(+) to isotropic membrane sites, but had no effect on Li(+)/Na(+) competition for those sites. Through the observed (23)Na DQF NMR spectra, which allow probing of both isotropic and anisotropic Na(+) motion, we found anisotropic membrane binding sites for Na(+) when the total ionic strength was higher than 40 mM. This is a consequence of ionic strength effects on the conformation of the cytoskeleton, in particular on the dimer-tetramer equilibrium of spectrin. The determinant involvement of the cytoskeleton in the anisotropy of Na(+) motion at the membrane surface was demonstrated by the isotropy of the DQF spectra of csdRBC membranes even at high ionic strength. Li(+) addition initially quenched the isotropic signal the most, indicating preferential Li(+)/Na(+) competition for the isotropic membrane sites. High ionic strength also increased the intensity of the anisotropic signal, due to its effect on the restructuring of the membrane cytoskeleton. Further Li(+) addition competed with Na(+) for those sites, quenching the anisotropic signal. (7)Li T(1) relaxation data for Li(+)-containing suspensions of unsealed and csdRBC membranes, in the absence and presence of Na(+) at low ionic strength, showed that cytoskeleton depletion does not affect the affinity of Na(+) for the RBC membrane, but increases the affinity of Li(+) by 50%. This clearly indicates that cytoskeleton depletion favors Li(+) relative to Na(+) binding, and thus Li(+)/Na(+) competition for its isotropic sites. Thus, this relaxation technique proves to be very sensitive to alkali metal binding to the membrane, detecting a more pronounced steric hindrance effect of the cytoskeleton network to binding of the larger hydrated Li(+) ion to the membrane phosphate groups.
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Affiliation(s)
- C Srinivasan
- Department of Chemistry, Loyola University of Chicago, 6525 N. Sheridan Road, Chicago, Illinois 60626, USA
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Anderson SE, Gray SD, Atherley R, Cala PM. Na-dependent changes in intracellular Ca in spontaneously hypertensive rat hearts. Comp Biochem Physiol A Mol Integr Physiol 1999; 123:299-309. [PMID: 10501022 DOI: 10.1016/s1095-6433(99)00071-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
To determine whether Na/Ca exchange is altered in primary hypertension, Na-dependent changes in intracellular Ca, ([Ca]i), were measured in isolated perfused hearts from Wistar-Kyoto (WKY) and spontaneously hypertensive (SHR) rats. Intracellular Na, (Nai, mEq/kg dry wt), and [Ca]i were measured by NMR spectroscopy. Control [Ca]i was less in WKY than SHR (176 +/- 18 vs 253 +/- 21 nmol/l; mean +/- S.E., P < 0.05), whereas Nai was not significantly different. One explanation for this is that net Na/Ca exchange flux is decreased in SHR. If this hypothesis is correct, the rate of Ca uptake in SHR should be less than WKY when Na/Ca exchange is reversed by decreasing the transmembrane Na gradient. The Na gradient was reduced by decreasing extracellular Na, ([Na]o) and/or by increasing [Na]i. To increase [Na]i, Na uptake was stimulated by acidification while Na extrusion by Na/K ATPase was inhibited by K-free perfusion. Seventeen minutes after acidification, Nai had increased but was not significantly different in SHR and WKY (18.0 +/- 2.3 to 57.4 +/- 7.6 vs 20.3 +/- 0.6 to 66.5 +/- 4.8 mEq/kg dry wt, respectively). Yet [Ca]i was greater in WKY than SHR (1768 +/- 142 vs 1201 +/- 90 nmol/l; P < 0.05). [Ca]i was also measured after decreasing [Na]o from 141 to 30 mmol/l. Fifteen minutes after reducing [Na]o, [Ca]i was greater in WKY than SHR (833 +/- 119 vs 425 +/- 94 nmol/l; P < 0.05). Thus for both protocols, decreasing the transmembrane Na gradient led to increased [Ca]i in both SHR and WKY, but less increase in SHR. The results are consistent with the hypothesis that Na/Ca exchange activity is less in SHR than WKY myocardium.
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Affiliation(s)
- S E Anderson
- Department of Human Physiology, University of California, Davis 95616-8644, USA.
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Abstract
Isolated, perfused rat livers were examined by single-quantum (SQ) and double-quantum-filtered (DQ-filtered) 23Na spectroscopy during prolonged global ischemia and during perfusion with ouabain, low-buffer potassium, or lithium-enriched buffer. Baseline separation of the intracellular (Na(i)+) and extracellular (Na(e)+) sodium resonances using TmDOTP5- allowed a direct comparison of temporal changes in SQ versus DQ-filtered Na(i)+. The SQ Na(i)+ signal increased approximately 150% during the first 15 min of global ischemia and then remained relatively constant over the next 45 min, while the DQ-filtered signal steadily increased approximately 400% over the same 60 min period. In similar experiments in which all perfusate sodium was replaced by lithium, the DQ-filtered Na(i)+ signal increased approximately 180% over a similar period of ischemia. Exposure of livers to ouabain also resulted in larger increases in DQ-filtered versus SQ signal of Na(i)+. The approximately 290% increase in DQ-filtered sodium observed during perfusion of livers with a hypokalemic buffer (1.2 mM K+) could be completely reversed by continued perfusion with a buffer containing normal levels of K+ (4.7 mM). These data suggest that the DQ-filtered Na(i)+ signal of liver does not simply report an increase in [Na(i)+], but may be exquisitely sensitive to other intracellular events initiated by altered physiology.
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Affiliation(s)
- J M Colet
- Department of Chemistry, University of Texas at Dallas, Richardson, USA
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