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Lachner S, Utzschneider M, Zaric O, Minarikova L, Ruck L, Zbýň Š, Hensel B, Trattnig S, Uder M, Nagel AM. Compressed sensing and the use of phased array coils in 23Na MRI: a comparison of a SENSE-based and an individually combined multi-channel reconstruction. Z Med Phys 2020; 31:48-57. [PMID: 33183893 DOI: 10.1016/j.zemedi.2020.10.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 09/23/2020] [Accepted: 10/02/2020] [Indexed: 11/30/2022]
Abstract
PURPOSE To implement and to evaluate a compressed sensing (CS) reconstruction algorithm based on the sensitivity encoding (SENSE) combination scheme (CS-SENSE), used to reconstruct sodium magnetic resonance imaging (23Na MRI) multi-channel breast data sets. METHODS In a simulation study, the CS-SENSE algorithm was tested and optimized by evaluating the structural similarity (SSIM) and the normalized root-mean-square error (NRMSE) for different regularizations and different undersampling factors (USF=1.8/3.6/7.2/14.4). Subsequently, the algorithm was applied to data from in vivo measurements of the healthy female breast (n=3) acquired at 7T. Moreover, the proposed CS-SENSE algorithm was compared to a previously published CS algorithm (CS-IND). RESULTS The CS-SENSE reconstruction leads to an increased image quality for all undersampling factors and employed regularizations. Especially if a simple 2nd order total variation is chosen as sparsity transformation, the CS-SENSE reconstruction increases the image quality of highly undersampled data sets (CS-SENSE: SSIMUSF=7.2=0.234, NRMSEUSF=7.2=0.491 vs. CS-IND: SSIMUSF=7.2=0.201, NRMSEUSF=7.2=0.506). CONCLUSION The CS-SENSE reconstruction supersedes the need of CS weighting factors for each channel as well as a method to combine single channel data. The CS-SENSE algorithm can be used to reconstruct undersampled data sets with increased image quality. This can be exploited to reduce total acquisition times in 23Na MRI.
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Affiliation(s)
- Sebastian Lachner
- Institute of Radiology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany.
| | - Matthias Utzschneider
- Institute of Radiology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Olgica Zaric
- High Field MR Center, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria
| | - Lenka Minarikova
- High Field MR Center, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria
| | - Laurent Ruck
- Institute of Radiology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Štefan Zbýň
- High Field MR Center, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria; Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, MN, USA
| | - Bernhard Hensel
- Center for Medical Physics and Engineering, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Siegfried Trattnig
- High Field MR Center, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria
| | - 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 Centre (DKFZ), Heidelberg, Germany; Institute of Medical Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
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Meyer MM, Haneder S, Konstandin S, Budjan J, Morelli JN, Schad LR, Kerl HU, Schoenberg SO, Kabbasch C. Repeatability and reproducibility of cerebral 23Na imaging in healthy subjects. BMC Med Imaging 2019; 19:26. [PMID: 30943911 PMCID: PMC6446283 DOI: 10.1186/s12880-019-0324-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Accepted: 03/11/2019] [Indexed: 02/04/2023] Open
Abstract
Background Initial reports of 23Na magnetic resonance imaging (MRI) date back to the 1970s. However, methodological challenges of the technique hampered its widespread adoption for many years. Recent technical developments have overcome some of these limitations and have led to more optimal conditions for 23Na-MR imaging. In order to serve as a reliable tool for the assessment of clinical stroke or brain tumor patients, we investigated the repeatability and reproducibility of cerebral sodium (23Na) imaging in healthy subjects. Methods In this prospective, IRB approved study 12 consecutive healthy volunteers (8 female, age 31 ± 8.3) underwent three cerebral 23Na-MRI examinations at 3.0 T (TimTrio, Siemens Healthineers) distributed between two separate visits with an 8 day interval. For each scan a T1w MP-RAGE sequence for anatomical referencing and a 3D-density-adapted, radial GRE-sequence for 23Na-imaging were acquired using a dual-tuned (23Na/1H) head-coil. On 1 day, these scans were repeated consecutively; on the other day, the scans were performed once. 23Na-sequences were reconstructed according to the MP-RAGE sequence, allowing direct cross-referencing of ROIs. Circular ROIs were placed in predetermined anatomic regions: gray and white matter (GM, WM), head of the caudate nucleus (HCN), pons, and cerebellum. External 23Na-reference phantoms were used to calculate the tissue sodium content. Results Excellent correlation was found between repeated measurements on the same day (r2 = 0.94), as well as on a different day (r2 = 0.86). No significant differences were found based on laterality other than in the HCN (63.1 vs. 58.7 mmol/kg WW on the right (p = 0.01)). Pronounced inter-individual differences were identified in all anatomic regions. Moderate to good correlation (0.310 to 0.701) was found between the readers. Conclusion Our study has shown that intra-individual 23Na-concentrations in healthy subjects do not significantly differ after repeated scans on the same day and a pre-set time interval. This confirms the repeatability and reproducibility of cerebral 23Na-imaging. However, with manual ROI placement in predetermined anatomic landmarks, fluctuations in 23Na-concentrations can be observed.
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Affiliation(s)
- Melissa M Meyer
- Institute of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany.
| | - Stefan Haneder
- Institute of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany.,Institute of Diagnostic and Interventional Radiology, University Hospital Cologne, University of Cologne, Cologne, Germany
| | | | - Johannes Budjan
- Institute of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany
| | - John N Morelli
- St. John's Medical Center, 1923 South Utica Ave, Tulsa, OK, 74104, USA
| | - Lothar R Schad
- Department of Computer Assisted Clinical Medicine, Heidelberg University, Mannheim, Germany
| | - Hans U Kerl
- Department of Neuroradiology, University Medical Center Mannheim, Heidelberg University, Mannheim, Germany
| | - Stefan O Schoenberg
- Institute of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany
| | - Christoph Kabbasch
- Institute of Diagnostic and Interventional Radiology, University Hospital Cologne, University of Cologne, Cologne, Germany
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Zöllner FG, Konstandin S, Lommen J, Budjan J, Schoenberg SO, Schad LR, Haneder S. Quantitative sodium MRI of kidney. NMR IN BIOMEDICINE 2016; 29:197-205. [PMID: 25728879 DOI: 10.1002/nbm.3274] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Revised: 01/13/2015] [Accepted: 01/25/2015] [Indexed: 05/25/2023]
Abstract
One of the main tasks of the human kidneys is to maintain the homeostasis of the body's fluid and electrolyte balance by filtration of the plasma and excretion of the end products. Herein, the regulation of extracellular sodium in the kidney is of particular importance. Sodium MRI ((23)Na MRI) allows for the absolute quantification of the tissue sodium concentration (TSC) and thereby provides a direct link between TSC and tissue viability. Renal (23)Na MRI can provide new insights into physiological tissue function and viability thought to differ from the information obtained by standard (1)H MRI. Sodium imaging has the potential to become an independent surrogate biomarker not only for renal imaging, but also for oncology indications. However, this technique is now on the threshold of clinical implementation. Numerous, initial pre-clinical and clinical studies have already outlined the potential of this technique; however, future studies need to be extended to larger patient groups to show the diagnostic outcome. In conclusion, (23)Na MRI is seen as a powerful technique with the option to establish a non-invasive renal biomarker for tissue viability, but is still a long way from real clinical implementation.
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Affiliation(s)
- Frank G Zöllner
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Simon Konstandin
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
- MR-Imaging and Spectroscopy, Faculty 01 (Physics/Electrical Engineering), University of Bremen, Bremen, Germany
| | - Jonathan Lommen
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Johannes Budjan
- Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Stefan O Schoenberg
- Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Lothar R Schad
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Stefan Haneder
- Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
- Department of Radiology, University Hospital of Cologne, Cologne, Germany
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Bottomley PA. Sodium MRI in human heart: a review. NMR IN BIOMEDICINE 2016; 29:187-96. [PMID: 25683054 PMCID: PMC4868405 DOI: 10.1002/nbm.3265] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Revised: 12/30/2014] [Accepted: 01/05/2015] [Indexed: 05/13/2023]
Abstract
This paper offers a critical review of the properties, methods and potential clinical application of sodium ((23)Na) MRI in human heart. Because the tissue sodium concentration (TSC) in heart is about ~40 µmol/g wet weight, and the (23)Na gyromagnetic ratio and sensitivity are respectively about one-quarter and one-11th of that of hydrogen ((1)H), the signal-to-noise ratio of (23)Na MRI in the heart is about one-6000th of that of conventional cardiac (1)H MRI. In addition, as a quadrupolar nucleus, (23)Na exhibits ultra-short and multi-component relaxation behavior (T1 ~ 30 ms; T2 ~ 0.5-4 ms and 12-20 ms), which requires fast, specialized, ultra-short echo-time MRI sequences, especially for quantifying TSC. Cardiac (23)Na MRI studies from 1.5 to 7 T measure a volume-weighted sum of intra- and extra-cellular components present at cytosolic concentrations of 10-15 mM and 135-150 mM in healthy tissue, respectively, at a spatial resolution of about 0.1-1 ml in 10 min or so. Currently, intra- and extra-cellular sodium cannot be unambiguously resolved without the use of potentially toxic shift reagents. Nevertheless, increases in TSC attributable to an influx of intra-cellular sodium and/or increased extra-cellular volume have been demonstrated in human myocardial infarction consistent with prior animal studies, and arguably might also be seen in future studies of ischemia and cardiomyopathies--especially those involving defects in sodium transport. While technical implementation remains a hurdle, a central question for clinical use is whether cardiac (23)Na MRI can deliver useful information unobtainable by other more convenient methods, including (1)H MRI.
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Affiliation(s)
- Paul A Bottomley
- Division of MR Research, Department of Radiology, Park Bldg 310, Johns Hopkins University, 601 600 N, Caroline Wolfe Street, Baltimore MD, USA 21287-0843, PH: (USA) 410 955 0366, FAX: (USA) 410 614 1977,
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Lommen J, Konstandin S, Krämer P, Schad LR. Enhancing the quantification of tissue sodium content by MRI: time-efficient sodium B1 mapping at clinical field strengths. NMR IN BIOMEDICINE 2016; 29:129-136. [PMID: 25904161 DOI: 10.1002/nbm.3292] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Revised: 02/19/2015] [Accepted: 03/03/2015] [Indexed: 06/04/2023]
Abstract
Tissue sodium content (TSC) is a sensitive measure of pathological changes and can be detected non-invasively by MRI. For the absolute quantification of TSC, B1 inhomogeneities must be corrected, which is not well established beyond research applications. An in-depth analysis of B1 mapping methods which are suitable for application in TSC quantification is presented. On the basis of these results, a method for simultaneous B1 mapping and imaging is proposed in order to enhance accuracy and to reduce measurement time at clinical field strengths. The B1 mapping techniques used were phase-sensitive (PS), Bloch-Siegert shift (BSS), double-angle (DAM) and actual flip-angle imaging (AFI) methods. Experimental and theoretical comparisons demonstrated that the PS technique yields the most accurate field profiles and exhibits the highest signal-to-noise ratio (SNR). Simultaneous B1 mapping and imaging was performed for the PS method, employing both degrees of freedom of the MR signal: the B1 field is encoded into signal phase and the amplitude provides the concentration information. In comparison with the more established DAM, a 13% higher SNR was obtained and field effects could be corrected more accurately without the need for additional measurement time. The protocol developed was applied to measure TSC in the healthy human head at an isotropic resolution of 4 mm. TSC was determined to be 35 ± 1 mM in white matter and 134 ± 3 mM in vitreous humor. By employing the proposed simultaneous characterization of the B1 field and acquisition of the spin density-weighted sodium signal, the accuracy of the non-invasive measurement of TSC is enhanced and the measurement time is reduced. This should allow (23)Na MRI to be better incorporated into clinical studies and routine.
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Affiliation(s)
- Jonathan Lommen
- Computer Assisted Clinical Medicine, Heidelberg University, Mannheim, Germany
- Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Simon Konstandin
- Computer Assisted Clinical Medicine, Heidelberg University, Mannheim, Germany
- MR-Imaging and Spectroscopy, Faculty 01 (Physics/Electrical Engineering), University of Bremen, Bremen, Germany
| | - Philipp Krämer
- Computer Assisted Clinical Medicine, Heidelberg University, Mannheim, Germany
| | - Lothar R Schad
- Computer Assisted Clinical Medicine, Heidelberg University, Mannheim, Germany
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Weingärtner S, Wetterling F, Konstandin S, Fatar M, Neumaier-Probst E, Schad LR. Scan time reduction in 23Na-Magnetic Resonance Imaging using the chemical shift imaging sequence: Evaluation of an iterative reconstruction method. Z Med Phys 2015; 25:275-86. [DOI: 10.1016/j.zemedi.2014.08.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Revised: 07/31/2014] [Accepted: 08/29/2014] [Indexed: 10/24/2022]
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Neumaier-Probst E, Konstandin S, Ssozi J, Groden C, Hennerici M, Schad LR, Fatar M. A double-tuned 1H/23Na resonator allows 1H-guided 23Na-MRI in ischemic stroke patients in one session. Int J Stroke 2015; 10 Suppl A100:56-61. [DOI: 10.1111/ijs.12547] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2014] [Accepted: 03/24/2015] [Indexed: 12/19/2022]
Abstract
Background Established imaging methods are still not confident in the determination of stroke onset. Sodium imaging in animal models and lately in humans implicates that the sodium signal intensity within the ischemic lesion increases in a time-dependent fashion. Sodium imaging usually requires a time-consuming change of resonators or magnetic resonance imaging systems. To avoid this, we used a double-tuned 1H/23Na birdcage head coil in combination with a protocol minimizing T1- and T2*-weighting effects for measurement of sodium intensity in acute stroke patients. Methods Multinuclear 1H/23Na data sets were obtained from 16 stroke patients [75 ± 9.9 (standard deviation) years old] 4-130 h after symptom onset. The protocol was acquired on a clinical 3T magnetic resonance imaging site using a double-tuned 1H/23Na birdcage head coil. Sodium signal intensity within the lesion and homologous contralateral side was measured and compared. Results With an acquisition time of the complete magnetic resonance imaging protocol of 22 min, a nonlinear sodium signal intensity increase within the lesion over time after stroke onset was acknowledged. Onset time within six-hours showed an increase of only 8% or less, whereas onset time beyond 8.5 h demonstrated increases of 36% or more reaching a maximum of 170% > 120 h. In addition, some patients showed a difference in sodium signal intensity compared with diffusion weighted imaging lesion. Conclusions The use of a double-tuned 1H/23Na birdcage head coil in a clinical setting ‘allowed sodium intensity measurements’ in a justifiable time also for acute stroke patients, and heterogenous sodium signal intensity in the diffusion weighted imaging lesion might represent differences in tissue damage or repair.
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Affiliation(s)
- Eva Neumaier-Probst
- Department of Neuroradiology, Universitätsmedizin Mannheim, University of Heidelberg, Mannheim, Germany
| | - Simon Konstandin
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
- MR-Imaging and Spectroscopy, Faculty 01 (Physics/Electrical Engineering), University of Bremen, Bremen, Germany
| | - Judith Ssozi
- Department of Neuroradiology, Universitätsmedizin Mannheim, University of Heidelberg, Mannheim, Germany
- Department of Diagnostic and Interventional Neuroradiology, Universitätsspital Basel, Basel, Switzerland
| | - Christoph Groden
- Department of Neuroradiology, Universitätsmedizin Mannheim, University of Heidelberg, Mannheim, Germany
| | - Michael Hennerici
- Department of Neurology, Universitätsmedizin Mannheim, University of Heidelberg, Mannheim, Germany
| | - Lothar R. Schad
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
| | - Marc Fatar
- Department of Neurology, Universitätsmedizin Mannheim, University of Heidelberg, Mannheim, Germany
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Zöllner FG, Kalayciyan R, Chacón-Caldera J, Zimmer F, Schad LR. Pre-clinical functional Magnetic Resonance Imaging part I: The kidney. Z Med Phys 2014; 24:286-306. [DOI: 10.1016/j.zemedi.2014.05.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Revised: 05/19/2014] [Accepted: 05/19/2014] [Indexed: 01/10/2023]
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23Na-MRI of recurrent glioblastoma multiforme after intraoperative radiotherapy: technical note. Neuroradiology 2014; 57:321-6. [DOI: 10.1007/s00234-014-1468-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Accepted: 11/17/2014] [Indexed: 11/25/2022]
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