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Torresan F, Rossi FB, Zanin S, Caputo I, Caroccia B, Iacobone M, Rossi GP. Water and Electrolyte Content in Salt-Dependent HYpertension in the SKIn (WHYSKI): Effect of Surgical Cure of Primary Aldosteronism. High Blood Press Cardiovasc Prev 2024; 31:15-21. [PMID: 38123759 PMCID: PMC10925570 DOI: 10.1007/s40292-023-00614-0] [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: 11/16/2023] [Accepted: 11/21/2023] [Indexed: 12/23/2023] Open
Abstract
INTRODUCTION: This study will test the hypothesis that primary aldosteronism (PA) involves alterations in Na+, K+, and water content in the skin that are corrected by adrenalectomy. AIM AND METHODS In skin biopsies, we will measure the content of Na+, K+, water, by physical-chemical methods and the osmotic-stress-responsive transcription factor Tonicity-responsive Enhancer Binding Protein (TonEBP, NFAT5) mRNA copy number by droplet digital PCR, in sex-balanced cohorts of 18 -75-year-old consecutive consenting patients with unilateral and bilateral PA, primary (essential) hypertension, and normotension. Before surgery, the patients with unilateral PA will receive the mineralocorticoid receptor antagonist (MRA) canrenone at doses that correct hypokalemia and high blood pressure values. They will be reassessed in an identical way one month after surgical cure, while off MRA. PA patients not selected for adrenalectomy will similarly be assessed at diagnosis and follow-up while on stable MRA treatment. Since a pilot study showed a direct correlation of dry weight (DW) with skin electrolytes and water content and significant differences of biopsy DW between surgery and follow-up, meaningful comparison of the skin cations and water content and TonEBP mRNA copy number, between specimen obtained at different time points, will require DW- and total mRNA-adjustment, respectively. CONCLUSION This study will provide novel information on the skin Na+, K+ and water content in PA, the paradigm of salt-dependent hypertension, and novel knowledge on the effect of surgical cure of hyperaldosteronism. The TonEBP-mediated regulation of Na+, K+ and water content in the skin will also be unveiled. TRAIL REGISTRY Trial Registration number: NCT06090617. Date of Registration: 2023-10-19.
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Affiliation(s)
- Francesca Torresan
- Endocrine Surgery Unit, Department of Surgery, Oncology, and Gastroenterology, University Hospital, University of Padua, Via Giustiniani, 2, 35128, Padua, Italy
| | - Federico Bernardo Rossi
- Internal and Emergency Unit and Specialized Hypertension Centre, Department of Medicine-DIMED, University Hospital, University of Padua, Via Giustiniani, 2, 35128, Padua, Italy
| | - Sofia Zanin
- Laboratory for Genetics of Mithocondrial Disorders, Imagine Institute, Université Paris Cité, Bd du Montparnasse, 24, 75015, Paris, France
| | - Ilaria Caputo
- Internal and Emergency Unit and Specialized Hypertension Centre, Department of Medicine-DIMED, University Hospital, University of Padua, Via Giustiniani, 2, 35128, Padua, Italy
| | - Brasilina Caroccia
- Internal and Emergency Unit and Specialized Hypertension Centre, Department of Medicine-DIMED, University Hospital, University of Padua, Via Giustiniani, 2, 35128, Padua, Italy
| | - Maurizio Iacobone
- Endocrine Surgery Unit, Department of Surgery, Oncology, and Gastroenterology, University Hospital, University of Padua, Via Giustiniani, 2, 35128, Padua, Italy
| | - Gian Paolo Rossi
- Internal and Emergency Unit and Specialized Hypertension Centre, Department of Medicine-DIMED, University Hospital, University of Padua, Via Giustiniani, 2, 35128, Padua, Italy.
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Nakagawa Y, Kaseda R, Suzuki Y, Watanabe H, Otsuka T, Yamamoto S, Kaneko Y, Goto S, Terada Y, Haishi T, Sasaki S, Narita I. Sodium Magnetic Resonance Imaging Shows Impairment of the Counter-current Multiplication System in Diabetic Mice Kidney. KIDNEY360 2023; 4:582-590. [PMID: 36963113 PMCID: PMC10278814 DOI: 10.34067/kid.0000000000000072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 01/17/2023] [Indexed: 03/26/2023]
Abstract
Key Points 23Na MRI allows us to noninvasively assess sodium distribution. We propose the utility of 23Na MRI for evaluating functional changes in diabetic kidney disease and not as a marker reflecting structural damage. 23Na MRI may be an early marker for structures beyond the glomeruli, enabling prompt intervention with novel efficacious tubule-targeting therapies. Background Sodium magnetic resonance imaging can noninvasively assess sodium distribution, specifically sodium concentration in the countercurrent multiplication system in the kidney, which forms a sodium concentration gradient from the cortex to the medulla, enabling efficient water reabsorption. This study aimed to investigate whether sodium magnetic resonance imaging can detect changes in sodium concentrations under normal conditions in mice and in disease models, such as a mouse model with diabetes mellitus. Methods We performed sodium and proton nuclear magnetic resonance imaging using a 9.4-T vertical standard-bore superconducting magnet. Results A condition of deep anesthesia, with widened breath intervals, or furosemide administration in 6-week-old C57BL/6JJcl mice showed a decrease in both tissue sodium concentrations in the medulla and sodium concentration gradients from the cortex to the medulla. Furthermore, sodium magnetic resonance imaging revealed reductions in the sodium concentration in the medulla and in the gradient from the cortex to the medulla in BKS.Cg-Leprdb+/+ Leprdb/Jcl mice at very early type 2 diabetes mellitus stages compared with corresponding control BKS.Cg-m+/m+/Jcl mice. Conclusions The kidneys of BKS.Cg-Leprdb+/+ Leprdb/Jcl mice aged 6 weeks showed impairments in the countercurrent multiplication system. We propose the utility of 23Na MRI for evaluating functional changes in diabetic kidney disease and not as a marker that reflects structural damage. Thus, 23Na MRI may be a potentially very early marker for structures beyond the glomerulus; this may prompt intervention with novel efficacious tubule-targeting therapies.
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Affiliation(s)
- Yusuke Nakagawa
- Division of Clinical Nephrology and Rheumatology, Kidney Research Center, Niigata University, Niigata, Niigata, Japan
| | - Ryohei Kaseda
- Division of Clinical Nephrology and Rheumatology, Kidney Research Center, Niigata University, Niigata, Niigata, Japan
| | - Yuya Suzuki
- Division of Clinical Nephrology and Rheumatology, Kidney Research Center, Niigata University, Niigata, Niigata, Japan
| | - Hirofumi Watanabe
- Division of Clinical Nephrology and Rheumatology, Kidney Research Center, Niigata University, Niigata, Niigata, Japan
| | - Tadashi Otsuka
- Division of Clinical Nephrology and Rheumatology, Kidney Research Center, Niigata University, Niigata, Niigata, Japan
| | - Suguru Yamamoto
- Division of Clinical Nephrology and Rheumatology, Kidney Research Center, Niigata University, Niigata, Niigata, Japan
| | - Yoshikatsu Kaneko
- Division of Clinical Nephrology and Rheumatology, Kidney Research Center, Niigata University, Niigata, Niigata, Japan
| | - Shin Goto
- Division of Clinical Nephrology and Rheumatology, Kidney Research Center, Niigata University, Niigata, Niigata, Japan
| | - Yasuhiko Terada
- Institute of Applied Physics, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Tomoyuki Haishi
- MRTechnology Inc., Tsukuba, Ibaraki, Japan
- Department of Radiological Sciences, School of Health Sciences at Narita, International University of Health and Welfare, Narita, Chiba, Japan
| | - Susumu Sasaki
- Faculty of Engineering, Niigata University, Niigata, Niigata, Japan
| | - Ichiei Narita
- Division of Clinical Nephrology and Rheumatology, Kidney Research Center, Niigata University, Niigata, Niigata, Japan
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Platt T, Ladd ME, Paech D. 7 Tesla and Beyond: Advanced Methods and Clinical Applications in Magnetic Resonance Imaging. Invest Radiol 2021; 56:705-725. [PMID: 34510098 PMCID: PMC8505159 DOI: 10.1097/rli.0000000000000820] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 08/07/2021] [Accepted: 08/07/2021] [Indexed: 12/15/2022]
Abstract
ABSTRACT Ultrahigh magnetic fields offer significantly higher signal-to-noise ratio, and several magnetic resonance applications additionally benefit from a higher contrast-to-noise ratio, with static magnetic field strengths of B0 ≥ 7 T currently being referred to as ultrahigh fields (UHFs). The advantages of UHF can be used to resolve structures more precisely or to visualize physiological/pathophysiological effects that would be difficult or even impossible to detect at lower field strengths. However, with these advantages also come challenges, such as inhomogeneities applying standard radiofrequency excitation techniques, higher energy deposition in the human body, and enhanced B0 field inhomogeneities. The advantages but also the challenges of UHF as well as promising advanced methodological developments and clinical applications that particularly benefit from UHF are discussed in this review article.
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Affiliation(s)
- Tanja Platt
- From the Medical Physics in Radiology, German Cancer Research Center (DKFZ)
| | - Mark E. Ladd
- From the Medical Physics in Radiology, German Cancer Research Center (DKFZ)
- Faculty of Physics and Astronomy
- Faculty of Medicine, University of Heidelberg, Heidelberg
- Erwin L. Hahn Institute for MRI, University of Duisburg-Essen, Essen
| | - Daniel Paech
- Division of Radiology, German Cancer Research Center (DKFZ), Heidelberg
- Clinic for Neuroradiology, University of Bonn, Bonn, Germany
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Zaric O, Juras V, Szomolanyi P, Schreiner M, Raudner M, Giraudo C, Trattnig S. Frontiers of Sodium MRI Revisited: From Cartilage to Brain Imaging. J Magn Reson Imaging 2020; 54:58-75. [PMID: 32851736 PMCID: PMC8246730 DOI: 10.1002/jmri.27326] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 05/20/2020] [Accepted: 05/20/2020] [Indexed: 12/19/2022] Open
Abstract
Sodium magnetic resonance imaging (23 Na-MRI) is a highly promising imaging modality that offers the possibility to noninvasively quantify sodium content in the tissue, one of the most relevant parameters for biochemical investigations. Despite its great potential, due to the intrinsically low signal-to-noise ratio (SNR) of sodium imaging generated by low in vivo sodium concentrations, low gyromagnetic ratio, and substantially shorter relaxation times than for proton (1 H) imaging, 23 Na-MRI is extremely challenging. In this article, we aim to provide a comprehensive overview of the literature that has been published in the last 10-15 years and which has demonstrated different technical designs for a range of 23 Na-MRI methods applicable for disease diagnoses and treatment efficacy evaluations. Currently, a wider use of 3.0T and 7.0T systems provide imaging with the expected increase in SNR and, consequently, an increased image resolution and a reduced scanning time. A great interest in translational research has enlarged the field of sodium MRI applications to almost all parts of the body: articular cartilage tendons, spine, heart, breast, muscle, kidney, and brain, etc., and several pathological conditions, such as tumors, neurological and degenerative diseases, and others. The quantitative parameter, tissue sodium concentration, which reflects changes in intracellular sodium concentration, extracellular sodium concentration, and intra-/extracellular volume fractions is becoming acknowledged as a reliable biomarker. Although the great potential of this technique is evident, there must be steady technical development for 23 Na-MRI to become a standard imaging tool. The future role of sodium imaging is not to be considered as an alternative to 1 H MRI, but to provide early, diagnostically valuable information about altered metabolism or tissue function associated with disease genesis and progression. LEVEL OF EVIDENCE: 1 TECHNICAL EFFICACY STAGE: 1.
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Affiliation(s)
- Olgica Zaric
- Institute for Clinical Molecular MRI in the Musculoskeletal System, Karl Landsteiner Society, Vienna, Austria
| | - Vladimir Juras
- High-Field MR Center, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria.,Department of Imaging Methods, Institute of Measurement Science, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Pavol Szomolanyi
- High-Field MR Center, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria
| | - Markus Schreiner
- Deartment of Orthopaedics and Trauma Surgery, Medical University of Vienna, Vienna, Austria
| | - Marcus Raudner
- High-Field MR Center, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria
| | - Chiara Giraudo
- Radiology Institute, Department of Medicine, DIMED Padova University Via Giustiniani 2, Padova, Italy
| | - Siegfried Trattnig
- Institute for Clinical Molecular MRI in the Musculoskeletal System, Karl Landsteiner Society, Vienna, Austria.,High-Field MR Center, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria.,Christian Doppler Laboratory for Clinical Molecular MRI, Christian Doppler Forschungsgesellschaft, Vienna, Austria
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5
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Cardiorenal sodium MRI in small rodents using a quadrature birdcage volume resonator at 9.4 T. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2019; 33:121-130. [PMID: 31797228 DOI: 10.1007/s10334-019-00810-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Accepted: 11/22/2019] [Indexed: 12/30/2022]
Abstract
OBJECTIVE Design, implementation, evaluation and application of a quadrature birdcage radiofrequency (RF) resonator tailored for renal and cardiac sodium (23Na) magnetic resonance imaging (MRI) in rats at 9.4 T. MATERIALS AND METHODS A low pass birdcage resonator (16 rungs, din = 62 mm) was developed. The transmission field (B1+) was examined with EMF simulations. The scattering parameter (S-parameter) and the quality factor (Q-factor) were measured. For experimental validation B1+-field maps were acquired with the double-angle method. In vivo sodium imaging of the heart (spatial resolution: (1 × 1 × 5) mm3) and kidney (spatial resolution: (1 × 1 × 10) mm3) was performed with a FLASH technique. RESULTS The RF resonator exhibits RF characteristics, transmission field homogeneity and penetration that afford 23Na MR in vivo imaging of the kidney and heart at 9.4 T. For the renal cortex and medulla a SNRs of 8 and 13 were obtained and a SNRs of 14 and 15 were observed for the left and right ventricle. DISCUSSION These initial results obtained in vivo in rats using the quadrature birdcage volume RF resonator for 23Na MRI permit dedicated studies on experimental models of cardiac and renal diseases, which would contribute to translational research of the cardiorenal syndrome.
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Boehmert L, Kuehne A, Waiczies H, Wenz D, Eigentler TW, Funk S, Knobelsdorff‐Brenkenhoff F, Schulz‐Menger J, Nagel AM, Seeliger E, Niendorf T. Cardiorenal sodium MRI at 7.0 Tesla using a 4/4 channel
1
H/
23
Na radiofrequency antenna array. Magn Reson Med 2019; 82:2343-2356. [DOI: 10.1002/mrm.27880] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 05/31/2019] [Accepted: 06/03/2019] [Indexed: 12/16/2022]
Affiliation(s)
- Laura Boehmert
- Berlin Ultrahigh Field Facility (B.U.F.F.) Max Delbrück Center for Molecular Medicine in the Helmholtz Association Berlin Germany
| | | | | | - Daniel Wenz
- Berlin Ultrahigh Field Facility (B.U.F.F.) Max Delbrück Center for Molecular Medicine in the Helmholtz Association Berlin Germany
| | - Thomas Wilhelm Eigentler
- Berlin Ultrahigh Field Facility (B.U.F.F.) Max Delbrück Center for Molecular Medicine in the Helmholtz Association Berlin Germany
| | - Stephanie Funk
- Working Group on Cardiovascular Magnetic Resonance, Experimental and Clinical Research Center, a joint cooperation between the Charité Medical Faculty and the Max Delbrück Center for Molecular Medicine Helios Clinics Berlin‐Buch Berlin Germany
| | - Florian Knobelsdorff‐Brenkenhoff
- Working Group on Cardiovascular Magnetic Resonance, Experimental and Clinical Research Center, a joint cooperation between the Charité Medical Faculty and the Max Delbrück Center for Molecular Medicine Helios Clinics Berlin‐Buch Berlin Germany
- Clinic Agatharied, Dept. of Cardiology Academic Teaching Hospital of the Ludwig‐Maximilians‐University Munich Hausham Germany
| | - Jeanette Schulz‐Menger
- Working Group on Cardiovascular Magnetic Resonance, Experimental and Clinical Research Center, a joint cooperation between the Charité Medical Faculty and the Max Delbrück Center for Molecular Medicine Helios Clinics Berlin‐Buch Berlin Germany
- DZHK (German Centre for Cardiovascular Research) partner site Berlin 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 University of Erlangen, Friedrich‐Alexander‐Universität Erlangen‐Nürnberg (FAU) Erlangen Germany
| | - Erdmann Seeliger
- Institute of Vegetative Physiology Charité University Medicine Berlin Germany
| | - Thoralf Niendorf
- Berlin Ultrahigh Field Facility (B.U.F.F.) Max Delbrück Center for Molecular Medicine in the Helmholtz Association Berlin Germany
- MRI.TOOLS GmbH Berlin Germany
- DZHK (German Centre for Cardiovascular Research) partner site Berlin Germany
- Experimental and Clinical Research Center, a joint cooperation between the Charité Medical Faculty and the Max Delbrück Center for Molecular Medicine Berlin Germany
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Hu R, Kleimaier D, Malzacher M, Hoesl MA, Paschke NK, Schad LR. X‐nuclei imaging: Current state, technical challenges, and future directions. J Magn Reson Imaging 2019; 51:355-376. [DOI: 10.1002/jmri.26780] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2019] [Revised: 04/23/2019] [Accepted: 04/24/2019] [Indexed: 12/16/2022] Open
Affiliation(s)
- Ruomin Hu
- Computer Assisted Clinical MedicineHeidelberg University Mannheim Germany
| | - Dennis Kleimaier
- Computer Assisted Clinical MedicineHeidelberg University Mannheim Germany
| | - Matthias Malzacher
- Computer Assisted Clinical MedicineHeidelberg University Mannheim Germany
| | | | - Nadia K. Paschke
- Computer Assisted Clinical MedicineHeidelberg University Mannheim Germany
| | - Lothar R. Schad
- Computer Assisted Clinical MedicineHeidelberg University Mannheim Germany
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8
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Lott J, Platt T, Niesporek SC, Paech D, G. R. Behl N, Niendorf T, Bachert P, Ladd ME, Nagel AM. Corrections of myocardial tissue sodium concentration measurements in human cardiac
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Na MRI at 7 Tesla. Magn Reson Med 2019; 82:159-173. [DOI: 10.1002/mrm.27703] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Revised: 01/25/2019] [Accepted: 01/31/2019] [Indexed: 12/24/2022]
Affiliation(s)
- Johanna Lott
- German Cancer Research Center (DKFZ), Medical Physics in Radiology Heidelberg Germany
- University of Heidelberg, Faculty of Physics and Astronomy Heidelberg Germany
| | - Tanja Platt
- German Cancer Research Center (DKFZ), Medical Physics in Radiology Heidelberg Germany
| | | | - Daniel Paech
- German Cancer Research Center (DKFZ) Radiology, Heidelberg Germany
| | - Nicolas G. R. Behl
- German Cancer Research Center (DKFZ), Medical Physics in Radiology Heidelberg Germany
| | - Thoralf Niendorf
- Max Delbrueck Center for Molecular Medicine in the Helmholtz Association Berlin Germany
- MRI. TOOLS GmbH Berlin Germany
| | - Peter Bachert
- German Cancer Research Center (DKFZ), Medical Physics in Radiology Heidelberg Germany
- University of Heidelberg, Faculty of Physics and Astronomy Heidelberg Germany
| | - Mark E. Ladd
- German Cancer Research Center (DKFZ), Medical Physics in Radiology Heidelberg Germany
- University of Heidelberg, Faculty of Physics and Astronomy Heidelberg Germany
- University of Heidelberg Faculty of Medicine Heidelberg Germany
| | - Armin M. Nagel
- German Cancer Research Center (DKFZ), Medical Physics in Radiology Heidelberg Germany
- Friedrich‐Alexander‐Universität Erlangen‐Nürnberg (FAU), University Hospital Erlangen Institute of Radiology Erlangen Germany
- Friedrich‐Alexander‐Universität Erlangen‐Nürnberg (FAU) Institute of Medical Physics Erlangen Germany
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23-Sodium magnetic resonance imaging of the human heart revisited: new insights in patients with Conn’s syndrome. Eur Heart J Cardiovasc Imaging 2018; 20:255-256. [DOI: 10.1093/ehjci/jey151] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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10
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Lommen JM, Flassbeck S, Behl NG, Niesporek S, Bachert P, Ladd ME, Nagel AM. Probing the microscopic environment of 23
Na ions in brain tissue by MRI: On the accuracy of different sampling schemes for the determination of rapid, biexponential T2* decay at low signal-to-noise ratio. Magn Reson Med 2018; 80:571-584. [DOI: 10.1002/mrm.27059] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Revised: 11/21/2017] [Accepted: 12/05/2017] [Indexed: 01/28/2023]
Affiliation(s)
- Jonathan M. Lommen
- Medical Physics in Radiology, German Cancer Research Center (DKFZ); Heidelberg Germany
| | - Sebastian Flassbeck
- Medical Physics in Radiology, German Cancer Research Center (DKFZ); Heidelberg Germany
| | - Nicolas G.R. Behl
- Medical Physics in Radiology, German Cancer Research Center (DKFZ); Heidelberg Germany
| | - Sebastian Niesporek
- Medical Physics in Radiology, German Cancer Research Center (DKFZ); Heidelberg Germany
| | - Peter Bachert
- Medical Physics in Radiology, German Cancer Research Center (DKFZ); Heidelberg Germany
- University of Heidelberg, Faculty of Physics and Astronomy; Heidelberg Germany
| | - Mark E. Ladd
- Medical Physics in Radiology, German Cancer Research Center (DKFZ); Heidelberg Germany
- University of Heidelberg, Faculty of Physics and Astronomy; Heidelberg Germany
- University of Heidelberg, Faculty of Medicine; Heidelberg Germany
| | - Armin M. Nagel
- Medical Physics in Radiology, German Cancer Research Center (DKFZ); Heidelberg Germany
- Institute of Radiology; University Hospital Erlangen; Erlangen Germany
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van de Weijer T, Paiman EHM, Lamb HJ. Cardiac metabolic imaging: current imaging modalities and future perspectives. J Appl Physiol (1985) 2017; 124:168-181. [PMID: 28473616 DOI: 10.1152/japplphysiol.01051.2016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
In this review, current imaging techniques and their future perspectives in the field of cardiac metabolic imaging in humans are discussed. This includes a range of noninvasive imaging techniques, allowing a detailed investigation of cardiac metabolism in health and disease. The main imaging modalities discussed are magnetic resonance spectroscopy techniques for determination of metabolite content (triglycerides, glucose, ATP, phosphocreatine, and so on), MRI for myocardial perfusion, and single-photon emission computed tomography and positron emission tomography for quantitation of perfusion and substrate uptake.
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12
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Bangerter NK, Tarbox GJ, Taylor MD, Kaggie JD. Quantitative sodium magnetic resonance imaging of cartilage, muscle, and tendon. Quant Imaging Med Surg 2016; 6:699-714. [PMID: 28090447 DOI: 10.21037/qims.2016.12.10] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Sodium magnetic resonance imaging (MRI), or imaging of the 23Na nucleus, has been under exploration for several decades, and holds promise for potentially revealing additional biochemical information about the health of tissues that cannot currently be obtained from conventional hydrogen (or proton) MRI. This additional information could serve as an important complement to conventional MRI for many applications. However, despite these exciting possibilities, sodium MRI is not yet used routinely in clinical practice, and will likely remain strictly in the domain of exploratory research for the coming decade. This paper begins with a technical overview of sodium MRI, including the nuclear magnetic resonance (NMR) signal characteristics of the sodium nucleus, the challenges associated with sodium MRI, and the specialized pulse sequences, hardware, and reconstruction techniques required. Various applications of sodium MRI for quantitative analysis of the musculoskeletal system are then reviewed, including the non-invasive assessment of cartilage degeneration in vivo, imaging of tendinopathy, applications in the assessment of various muscular pathologies, and assessment of muscle response to exercise.
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Affiliation(s)
- Neal K Bangerter
- Department of Electrical & Computer Engineering, Brigham Young University, Provo, UT, USA;; Department of Radiology, University of Utah, Salt Lake City, UT, USA
| | - Grayson J Tarbox
- Department of Electrical & Computer Engineering, Brigham Young University, Provo, UT, USA
| | - Meredith D Taylor
- Department of Electrical & Computer Engineering, Brigham Young University, Provo, UT, USA
| | - Joshua D Kaggie
- Department of Radiology, University of Cambridge, Cambridge, UK
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13
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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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14
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Bangerter NK, Kaggie JD, Taylor MD, Hadley JR. Sodium MRI radiofrequency coils for body imaging. NMR IN BIOMEDICINE 2016; 29:107-118. [PMID: 26417667 DOI: 10.1002/nbm.3392] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Revised: 08/08/2015] [Accepted: 08/11/2015] [Indexed: 06/05/2023]
Abstract
The proliferation of high-field whole-body systems, advances in gradient performance and refinement of signal-to-noise ratio (SNR)-efficient short-TE sequences suitable for sodium imaging have led to a resurgence of interest in sodium imaging for body applications. With this renewed interest has come increased demand for SNR-efficient sodium coils. Efficient coils can significantly increase SNR in sodium imaging, allowing higher resolutions and/or shorter scan times. In this work, we focus on body imaging applications of sodium MRI, and review developments in MRI radiofrequency (RF) coil topologies for sodium imaging. We first provide a brief discussion of RF coil design considerations in sodium imaging. This is followed by an overview of common coil topologies, their advantages and disadvantages, and examples of each.
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Affiliation(s)
- Neal K Bangerter
- Department of Electrical and Computer Engineering, Brigham Young University, Provo, UT, USA
- Department of Radiology, University of Utah, Salt Lake City, UT, USA
| | - Joshua D Kaggie
- Department of Physics, University of Utah, Salt Lake City, UT, USA
- Department of Radiology, University of Cambridge, Cambridge, UK
| | - Meredith D Taylor
- Department of Electrical and Computer Engineering, Brigham Young University, Provo, UT, USA
| | - J Rock Hadley
- Department of Radiology, University of Utah, Salt Lake City, UT, USA
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15
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Retrospectively-gated CINE 23Na imaging of the heart at 7.0 Tesla using density-adapted 3D projection reconstruction. Magn Reson Imaging 2015; 33:1091-1097. [DOI: 10.1016/j.mri.2015.06.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Revised: 05/28/2015] [Accepted: 06/20/2015] [Indexed: 11/21/2022]
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16
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Lee KC, Yu JF, Lee YS, Huang GJ, Chan HL, Lin IT, Chen JH. In Vivo Sodium MRI for Mouse Model of Ischemic Stroke at 7 T: Preliminary Results. J Med Biol Eng 2015. [DOI: 10.1007/s40846-015-0072-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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17
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Graessl A, Ruehle A, Waiczies H, Resetar A, Hoffmann SH, Rieger J, Wetterling F, Winter L, Nagel AM, Niendorf T. Sodium MRI of the human heart at 7.0 T: preliminary results. NMR IN BIOMEDICINE 2015; 28:967-975. [PMID: 26082025 DOI: 10.1002/nbm.3338] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Revised: 05/10/2015] [Accepted: 05/12/2015] [Indexed: 06/04/2023]
Abstract
The objective of this work was to examine the feasibility of three-dimensional (3D) and whole heart coverage (23)Na cardiac MRI at 7.0 T including single-cardiac-phase and cinematic (cine) regimes. A four-channel transceiver RF coil array tailored for (23)Na MRI of the heart at 7.0 T (f = 78.5 MHz) is proposed. An integrated bow-tie antenna building block is used for (1)H MR to support shimming, localization and planning in a clinical workflow. Signal absorption rate simulations and assessment of RF power deposition were performed to meet the RF safety requirements. (23) Na cardiac MR was conducted in an in vivo feasibility study. 3D gradient echo (GRE) imaging in conjunction with Cartesian phase encoding (total acquisition time T(AQ) = 6 min 16 s) and whole heart coverage imaging employing a density-adapted 3D radial acquisition technique (T(AQ) = 18 min 20 s) were used. For 3D GRE-based (23)Na MRI, acquisition of standard views of the heart using a nominal in-plane resolution of (5.0 × 5.0) mm(2) and a slice thickness of 15 mm were feasible. For whole heart coverage 3D density-adapted radial (23)Na acquisitions a nominal isotropic spatial resolution of 6 mm was accomplished. This improvement versus 3D conventional GRE acquisitions reduced partial volume effects along the slice direction and enabled retrospective image reconstruction of standard or arbitrary views of the heart. Sodium cine imaging capabilities were achieved with the proposed RF coil configuration in conjunction with 3D radial acquisitions and cardiac gating. Cardiac-gated reconstruction provided an enhancement in blood-myocardium contrast of 20% versus the same data reconstructed without cardiac gating. The proposed transceiver array enables (23)Na MR of the human heart at 7.0 T within clinical acceptable scan times. This capability is in positive alignment with the needs of explorations that are designed to examine the potential of (23)Na MRI for the assessment of cardiovascular and metabolic diseases.
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Affiliation(s)
- Andreas Graessl
- Berlin Ultrahigh Field Facility (BUFF), Max-Delbrueck-Center for Molecular Medicine, Berlin, Germany
| | - Anjuli Ruehle
- Berlin Ultrahigh Field Facility (BUFF), Max-Delbrueck-Center for Molecular Medicine, Berlin, Germany
| | | | - Ana Resetar
- Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Stefan H Hoffmann
- Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | | | | | - Lukas Winter
- Berlin Ultrahigh Field Facility (BUFF), Max-Delbrueck-Center for Molecular Medicine, Berlin, Germany
| | - Armin M Nagel
- Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Thoralf Niendorf
- Berlin Ultrahigh Field Facility (BUFF), Max-Delbrueck-Center for Molecular Medicine, Berlin, Germany
- Experimental and Clinical Research Center, a joint cooperation between the Charité Medical Faculty and the Max-Delbrück Center for Molecular Medicine, Berlin, Germany
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18
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Stanely Mainzen Prince P, Dhanasekar K, Rajakumar S. Vanillic acid prevents altered ion pumps, ions, inhibits Fas-receptor and caspase mediated apoptosis-signaling pathway and cardiomyocyte death in myocardial infarcted rats. Chem Biol Interact 2015; 232:68-76. [DOI: 10.1016/j.cbi.2015.03.009] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2014] [Revised: 02/25/2015] [Accepted: 03/09/2015] [Indexed: 11/16/2022]
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19
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A biochemical and 2, 3, 5-triphenyl tetrazolium chloride staining study on the preventive effects of zingerone (vanillyl acetone) in experimentally induced myocardial infarcted rats. Eur J Pharmacol 2014; 746:198-205. [PMID: 25445034 DOI: 10.1016/j.ejphar.2014.10.057] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2014] [Revised: 10/22/2014] [Accepted: 10/28/2014] [Indexed: 11/23/2022]
Abstract
Myocardial infarction continues to be a major public health problem, not only in western countries but also increasingly in developing countries and makes significant contribution to the mortality statistics. Reduction in mortality rate and prevention of myocardial infarction are of utmost importance. Tachycardia, left ventricular hypertrophy (LVH), altered adenosine triphosphatases (ATPases), and shifts in electrolyte balance play a vital role in the pathogenesis of myocardial infarction. This study was designed to evaluate the preventive effects of zingerone (vanillyl acetone) on tachycardia, LVH, altered electrocardiogram (ECG), altered activities of membrane bound ATPases, electrolyte imbalance and myocardial infarct size in isoproterenol induced myocardial infarcted rats. Rats were pretreated with zingerone (vanillyl acetone) 6 mg/kg body weight daily for a period of 14 days and were then induced myocardial infarction with isoproterenol (100 mg/kg body weight) on 15th and 16th day. Isoproterenol induced myocardial infarcted rats showed tachycardia, LVH, altered ECG, serum cardiac troponin-T, plasma myoglobin, heart ATPases, heart sodium ion, calcium ion, potassium ion, and increased myocardial infarct size. Pretreatment with zingerone (vanillyl acetone) revealed preventive effects on tachycardia, LVH, ECG, and all the above mentioned biochemical parameters evaluated in isoproterenol induced myocardial infarcted rats. The 2, 3, 5-triphenyl tetrazolium chloride staining on myocardial infarct size confirmed the prevention of myocardial infarction. Further, the in vitro study revealed a very convincing free radical scavenging of zingerone (vanillyl acetone). Thus, the observed effects of zingerone (vanillyl acetone) are due to its antioxidant and free radical scavenging activities in isoproterenol induced myocardial infarcted rats.
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20
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Liu H, Zhou D, Garcia ML, Kohler MG, Shen X, Williams DS, Klimas MT, Hargreaves RJ, Kaczorowski GJ. Characteristic time courses of cortical and medullary sodium signals measured by noninvasive23Na-MRI in rat kidney induced by furosemide. J Magn Reson Imaging 2014; 41:1622-8. [PMID: 25168165 DOI: 10.1002/jmri.24732] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2014] [Accepted: 08/04/2014] [Indexed: 11/05/2022] Open
Affiliation(s)
- Haiying Liu
- Imaging; Merck Research Labs; Kenilworth New Jersey USA
| | - Dan Zhou
- In vivo Pharmacology; Merck Research Labs; Kenilworth New Jersey USA
| | - Maria L. Garcia
- Ion Channel Department; Merck Research Labs; Kenilworth New Jersey USA
| | - Martin G. Kohler
- Ion Channel Department; Merck Research Labs; Kenilworth New Jersey USA
| | - Xiaolan Shen
- Lab Animal Resources; Merck Research Labs; Kenilworth New Jersey USA
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21
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Fernández-Jiménez R, Fernández-Friera L, Sánchez-González J, Ibáñez B. Animal Models of Tissue Characterization of Area at Risk, Edema and Fibrosis. CURRENT CARDIOVASCULAR IMAGING REPORTS 2014. [DOI: 10.1007/s12410-014-9259-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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22
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Gnahm C, Bock M, Bachert P, Semmler W, Behl NGR, Nagel AM. Iterative 3D projection reconstruction of 23
Na data with an 1
H MRI constraint. Magn Reson Med 2013; 71:1720-32. [DOI: 10.1002/mrm.24827] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2012] [Revised: 05/07/2013] [Accepted: 05/07/2013] [Indexed: 01/27/2023]
Affiliation(s)
- Christine Gnahm
- Department of Medical Physics in Radiology; German Cancer Research Center (DKFZ); Heidelberg Germany
| | - Michael Bock
- Department of Medical Physics in Radiology; German Cancer Research Center (DKFZ); Heidelberg Germany
- Radiology-Medical Physics; University Hospital Freiburg; Freiburg Germany
| | - Peter Bachert
- Department of Medical Physics in Radiology; German Cancer Research Center (DKFZ); Heidelberg Germany
| | - Wolfhard Semmler
- Department of Medical Physics in Radiology; German Cancer Research Center (DKFZ); Heidelberg Germany
| | - Nicolas G. R. Behl
- Department of Medical Physics in Radiology; German Cancer Research Center (DKFZ); Heidelberg Germany
| | - Armin M. Nagel
- Department of Medical Physics in Radiology; German Cancer Research Center (DKFZ); Heidelberg Germany
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23
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Aguor ENE, van de Kolk CWA, Arslan F, Nederhoff MGJ, Doevendans PAFM, Pasterkamp G, Strijkers GJ, van Echteld CJA. 23Na chemical shift imaging and Gd enhancement of myocardial edema. Int J Cardiovasc Imaging 2012; 29:343-54. [PMID: 22790331 PMCID: PMC3560947 DOI: 10.1007/s10554-012-0093-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Accepted: 06/27/2012] [Indexed: 12/24/2022]
Abstract
Myocardial edema can arise in several disease states. MRI contrast agent can accumulate in edematous tissue, which complicates differential diagnosis with contrast-enhanced (CE)-MRI and might lead to overestimation of infarct size. Sodium Chemical Shift Imaging ((23)Na-CSI) may provide an alternative for edema imaging. We have developed a non-infarct, isolated rat heart model with two levels of edema, which was studied with (23)Na-CSI and CE-MRI. In edematous, but viable tissue the extracellular sodium (Na (e) (+)) signal is hypothesized to increase, but not the intracellular sodium (Na (i) (+)) signal. Isolated hearts were perfused at 60 (n = 6) and 140 mmHg (n = 5). Dimethyl methylphosphonate (DMMP) and phenylphosphonate (PPA) were used to follow edema formation by (31)P-MR Spectroscopy. In separate groups, Thulium(III)1,4,7,10 tetraazacyclododecane-N,N',N″,N'''-tetra(methylenephosphonate) (TmDOTP(5-)) and Gadovist were used for (23)Na-CSI (n = 8) and CE-MRI (n = 6), respectively. PPA normalized signal intensity (SI) was higher at 140 versus 60 mmHg, with a ratio of 1.27 ± 0.12 (p < 0.05). The (DMMP-PPA)/dry weight ratio, as a marker of intracellular volume, remained unchanged. The mid-heart cross sectional area (CSA) of the left ventricle (LV) was significantly increased at 140 mmHg. In addition, at 140 mmHg, the LV Na (e) (+) SI increased with a 140 mmHg/60 mmHg ratio of 1.24 ± 0.18 (p < 0.05). Na (i) (+) SI remained essentially unchanged. With CE-MRI, a subendocardially enhanced CSA was identified, increasing from 0.20 ± 0.02 cm(2) at 60 mmHg to 0.31 ± 0.02 cm(2) at 140 mmHg (p < 0.05). Edema shows up in both CE-MRI and Na (e) (+) . High perfusion pressure causes more edema subendocardially than subepicardially. (23)Na-CSI is an attractive alternative for imaging of edema and is a promising tool to discriminate between edema, acute and chronic MI.
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Affiliation(s)
- Eissa N E Aguor
- Laboratory of Experimental Cardiology, University Medical Center Utrecht (UMCU), Utrecht, The Netherlands.
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24
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Kannan MM, Quine SD, Sangeetha T. Protective efficacy of ellagic acid on glycoproteins, hematological parameters, biochemical changes, and electrolytes in myocardial infarcted rats. J Biochem Mol Toxicol 2012; 26:270-5. [DOI: 10.1002/jbt.21418] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2011] [Revised: 03/22/2012] [Accepted: 04/25/2012] [Indexed: 11/06/2022]
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25
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Quantitative analysis in magnetic resonance spectroscopy: from metabolic profiling to in vivo biomarkers. Bioanalysis 2012; 4:321-41. [PMID: 22303835 DOI: 10.4155/bio.11.320] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Nuclear magnetic resonance spectroscopy (called NMR for ex vivo techniques and MRS for in vivo techniques) has become a useful analytical and diagnostic tool in biomedicine. In the past two decades, an MR-based spectroscopic approach for translational and clinical research has emerged that allows for biochemical characterization of the tissue of interest either ex vivo (NMR-based metabolomics) or in vivo (localized MRS-single voxel or multivoxel-spectroscopic imaging). The greatest advantages of MRS techniques are their ability to detect multiple tissue-specific metabolites in a single experiment, their quantitative nature and translational component (in vitro/ex vivo-discovered metabolic biomarkers can be translated into noninvasive spectroscopic imaging protocols). Disadvantages of MRS include low sensitivity and spectral resolution and, in case of NMR-metabolomics, metabolite degradation and incomplete recovery in processed samples. In vivo MRS has worse spectral resolution than ex vivo high-resolution NMR due to the inherently wider lines of metabolites in vivo and the difficulty of using traditional line-narrowing methods (e.g., sample spinning). It also suffers from poor time-resolution, therefore offering fewer metabolic biomarkers to be followed in vivo. In the present review article, we provide considerations for establishing reliable protocols (both in vivo and ex vivo) for metabolite detection, recovery and quantification from in vivo and ex vivo MR spectra.
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26
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Wu G, Zhu J. NMR studies of alkali metal ions in organic and biological solids. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2012; 61:1-70. [PMID: 22340207 DOI: 10.1016/j.pnmrs.2011.06.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2010] [Accepted: 05/31/2011] [Indexed: 05/31/2023]
Affiliation(s)
- Gang Wu
- Department of Chemistry, Queen's University, 90 Bader Lane, Kingston, Ontario, Canada.
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27
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Juras V, Zbýň Š, Pressl C, Domayer SER, Hofstaetter JG, Mayerhoefer ME, Windhager R, Trattnig S. Sodium MR Imaging of Achilles Tendinopathy at 7 T: Preliminary Results. Radiology 2012; 262:199-205. [DOI: 10.1148/radiol.11110897] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023]
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28
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Qian Y, Zhao T, Zheng H, Weimer J, Boada FE. High-resolution sodium imaging of human brain at 7 T. Magn Reson Med 2011; 68:227-33. [PMID: 22144258 DOI: 10.1002/mrm.23225] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2011] [Revised: 08/29/2011] [Accepted: 08/30/2011] [Indexed: 01/17/2023]
Abstract
The feasibility of high-resolution sodium magnetic resonance imaging on human brain at 7 T was demonstrated in this study. A three-dimensional anisotropic resolution data acquisition was used to address the challenge of low signal-to-noise ratio associated with high resolution. Ultrashort echo-time sequence was used for the anisotropic data acquisition. Phantoms and healthy human brains were studied on a whole-body 7-T magnetic resonance imaging scanner. Sodium images were obtained at two high nominal in-plane resolutions (1.72 and 0.86 mm) at a slice thickness of 4 mm. Signal-to-noise ratio in the brain image (cerebrospinal fluid) was measured as 14.4 and 6.8 at the two high resolutions, respectively. The actual in-plane resolution was measured as 2.9 and 1.6 mm, 69-86% larger than their nominal values. The quantification of sodium concentration on the phantom and brain images enabled better accuracy at the high nominal resolutions than at the low nominal resolution of 3.44 mm (measured resolution 5.5 mm) due to the improvement of in-plane resolution.
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Affiliation(s)
- Yongxian Qian
- MR Research Center, Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
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29
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Kopp C, Linz P, Wachsmuth L, Dahlmann A, Horbach T, Schöfl C, Renz W, Santoro D, Niendorf T, Müller DN, Neininger M, Cavallaro A, Eckardt KU, Schmieder RE, Luft FC, Uder M, Titze J. (23)Na magnetic resonance imaging of tissue sodium. Hypertension 2011; 59:167-72. [PMID: 22146510 DOI: 10.1161/hypertensionaha.111.183517] [Citation(s) in RCA: 195] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Hypertension is linked to disturbed total-body sodium (Na(+)) regulation; however, measuring Na(+) disposition in the body is difficult. We implemented (23)Na magnetic resonance spectroscopy ((23)Na-MR) and imaging technique ((23)Na-MRI) at 9.4T for animals and 3T for humans to quantify Na(+) content in skeletal muscle and skin. We compared (23)Na-MRI data with actual tissue Na(+) content measured by chemical analysis in animal and human tissue. We then quantified tissue Na(+) content in normal humans and in patients with primary aldosteronism. We found a 29% increase in muscle Na(+) content in patients with aldosteronism compared with normal women and men. This tissue Na(+) was mobilized after successful treatment without accompanying weight loss. We suggest that, after further refinements, this tool could facilitate understanding the relationships between Na(+) accumulation and hypertension. Furthermore, with additional technical advances, a future clinical use may be possible.
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Affiliation(s)
- Christoph Kopp
- Department of Nephrology and Hypertension, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
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30
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Lu A, Atkinson IC, Vaughn JT, Thulborn KR. Impact of gradient timing error on the tissue sodium concentration bioscale measured using flexible twisted projection imaging. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2011; 213:176-181. [PMID: 21944734 PMCID: PMC3217314 DOI: 10.1016/j.jmr.2011.08.036] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2011] [Revised: 08/12/2011] [Accepted: 08/29/2011] [Indexed: 05/31/2023]
Abstract
The rapid biexponential transverse relaxation of the sodium MR signal from brain tissue requires efficient k-space sampling for quantitative imaging in a time that is acceptable for human subjects. The flexible twisted projection imaging (flexTPI) sequence has been shown to be suitable for quantitative sodium imaging with an ultra-short echo time to minimize signal loss. The fidelity of the k-space center location is affected by the readout gradient timing errors on the three physical axes, which is known to cause image distortion for projection-based acquisitions. This study investigated the impact of these timing errors on the voxel-wise accuracy of the tissue sodium concentration (TSC) bioscale measured with the flexTPI sequence. Our simulations show greater than 20% spatially varying quantification errors when the gradient timing errors are larger than 10 μs on all three axes. The quantification is more tolerant of gradient timing errors on the Z-axis. An existing method was used to measure the gradient timing errors with <1 μs error. The gradient timing error measurement is shown to be RF coil dependent, and timing error differences of up to ∼16 μs have been observed between different RF coils used on the same scanner. The measured timing errors can be corrected prospectively or retrospectively to obtain accurate TSC values.
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Affiliation(s)
- Aiming Lu
- Center for Magnetic Resonance Research, University of Illinois at Chicago, Chicago, IL 60612, United States.
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31
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Pang Y, Xie Z, Xu D, Kelley DA, Nelson SJ, Vigneron DB, Zhang X. A dual-tuned quadrature volume coil with mixed λ/2 and λ/4 microstrip resonators for multinuclear MRSI at 7 T. Magn Reson Imaging 2011; 30:290-8. [PMID: 22055851 DOI: 10.1016/j.mri.2011.09.022] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2010] [Revised: 08/29/2011] [Accepted: 09/18/2011] [Indexed: 11/24/2022]
Abstract
In this work, an eight-element by eight-element dual-tuned quadrature volume coil with a mix of capacitor terminated half-wavelength (λ/2) and quarter-wavelength (λ/4) microstrip resonators is proposed for multinuclear magnetic resonance imaging/spectroscopy studies at 7 T. In the proton channel, λ/2 microstrip resonators with capacitive terminations on both ends are employed for operation at higher frequency of 298.1 MHz; in the heteronucleus channel, capacitor-terminated λ/4 resonators, suitable for low frequency operations, are used to meet the low frequency requirement. This mixed structure design is particularly advantageous for high field heteronuclei magnetic resonance applications with large difference in Larmor frequency of the nuclei in question. The proposed design method makes it much easier to perform frequency tuning for heteronucleus channel using a variable capacitor with a practical capacitance range. As an example, a dual-tuned volume coil for (1)H/(13)C mouse spectroscopic imaging was proposed to demonstrate the feasibility of this method. The finite-difference time-domain method is first used to model this dual-tuned volume coil and calculate the B(1) field distributions at two frequencies. Transmission parameters (S(21)) measured between the proton channel and the carbon channel are -50 dB at 75 MHz and -35 dB at 298 MHz, showing the excellent isolation between the two channels at 7 T. The proton image and (13)C FIDCSI image of a corn oil phantom on the axial plane at 7 T demonstrate the feasibility of the proposed method. A preliminary proton image of a mouse on the sagittal plane is also acquired using the proposed dual-tuned volume coil at 7 T, illustrating a fairly uniform B(1) field and sufficient image coverage for imaging in mice.
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Affiliation(s)
- Yong Pang
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA 94158-2330, USA
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32
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Abstract
Sodium ((23)Na) imaging has a place somewhere between (1)H-MRI and MR spectroscopy (MRS). Like MRS it potentially provides information on metabolic processes, but only one single resonance of ionic (23)Na is observed. Therefore pulse sequences do not need to code for a chemical shift dimension, allowing (23)Na images to be obtained at high resolutions as compared to MRS. In this chapter the biological significance of sodium in the brain will be discussed, as well as methods for observing it with (23)Na-MRI. Many vital cellular processes and interactions in excitable tissues depend on the maintenance of a low intracellular and high extracellular sodium concentration. Healthy cells maintain this concentration gradient at the cost of energy. Leaky cell membranes or an impaired energy metabolism immediately leads to an increase in cytosolic total tissue sodium. This makes sodium a biomarker for ischemia, cancer, excessive tissue activation, or tissue damage as might be caused by ablation therapy. Special techniques allow quantification of tissue sodium for the monitoring of disease or therapy in longitudinal studies or preferential observation of the intracellular component of the tissue sodium. New methods and high-field magnet technology provide new opportunities for (23)Na-MRI in clinical and biomedical research.
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Affiliation(s)
- Ronald Ouwerkerk
- Cardiovascular Imaging, National Institute of Diabetes and Digestive and Kidney Disease, National Institute of Health, Bethesda, MD, USA.
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33
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Lu A, Atkinson IC, Claiborne TC, Damen FC, Thulborn KR. Quantitative sodium imaging with a flexible twisted projection pulse sequence. Magn Reson Med 2010; 63:1583-93. [PMID: 20512862 DOI: 10.1002/mrm.22381] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The quantification of sodium MR images from an arbitrary intensity scale into a bioscale fosters image interpretation in terms of the spatially resolved biochemical process of sodium ion homeostasis. A methodology for quantifying tissue sodium concentration using a flexible twisted projection imaging sequence is proposed that allows for optimization of tradeoffs between readout time, signal-to-noise ratio efficiency, and sensitivity to static field susceptibility artifacts. The gradient amplitude supported by the slew rate at each k-space radius regularizes the readout gradient waveform design to avoid slew rate violation. Static field inhomogeneity artifacts are corrected using a frequency-segmented conjugate phase reconstruction approach, with field maps obtained quickly from coregistered proton imaging. High-quality quantitative sodium images have been achieved in phantom and volunteer studies with real isotropic spatial resolution of 7.5 x 7.5 x 7.5 mm(3) for the slow T(2) component in approximately 8 min on a clinical 3-T scanner. After correcting for coil sensitivity inhomogeneity and water fraction, the tissue sodium concentration in gray matter and white matter was measured to be 36.6 +/- 0.6 micromol/g wet weight and 27.6 +/- 1.2 micromol/g wet weight, respectively.
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Affiliation(s)
- Aiming Lu
- Center for Magnetic Resonance Research, University of Illinois at Chicago, Chicago, Illinois 60612, USA.
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34
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Kirsch S, Augath M, Seiffge D, Schilling L, Schad LR. In vivo chlorine-35, sodium-23 and proton magnetic resonance imaging of the rat brain. NMR IN BIOMEDICINE 2010; 23:592-600. [PMID: 20232452 DOI: 10.1002/nbm.1500] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
In this study we demonstrate the feasibility of combined chlorine-35, sodium-23 and proton magnetic resonance imaging (MRI) at 9.4 Tesla, and present the first in vivo chlorine-35 images obtained by means of MRI. With the experimental setup used in this study all measurements could be done in one session without changing the setup or moving the subject. The multinuclear measurement requires a total measurement time of 2 h and provides morphological (protons) and physiological (sodium-23, chlorine-35) information in one scanning session. Chlorine-35, sodium-23 and high resolution proton images were acquired from a phantom, a healthy rat and from a rat displaying a focal cerebral infarction. Compared to the healthy tissue a signal enhancement of a factor of 2.2 +/- 0.2 in the chlorine-35 and a factor of 2.9 +/- 0.6 in the sodium-23 images is observed in the areas of infarction. Exemplary unlocalized measurement of the in vivo longitudinal and transversal relaxation time of chlorine-35 in a healthy rat showed multi-exponential behaviour. A biexponential fit revealed a fast and a slow relaxing component with T(1,a) = (1.7 +/- 0.4) ms, T(1,b) = (25.1 +/- 1.4) ms, amplitudes of A = 0.26 +/- 0.02, (1-A) = 0.74 +/- 0.02 and T(2,a) = (1.3 +/- 0.1) ms, T(2,b) = (11.8 +/- 1.1) ms, A = 0.64 +/- 0.02, (1-A) = 0.36 +/- 0.02. Combined proton, sodium-23 and chlorine-35 MRI may provide a new approach for non-invasive studies of ionic regulatory processes under physiological and pathological conditions in vivo.
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Affiliation(s)
- Stefan Kirsch
- Department of Computer Assisted Clinical Medicine, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany.
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Atthe BK, Babsky AM, Hopewell PN, Phillips CL, Molitoris BA, Bansal N. Early monitoring of acute tubular necrosis in the rat kidney by 23Na-MRI. Am J Physiol Renal Physiol 2009; 297:F1288-98. [PMID: 19726545 DOI: 10.1152/ajprenal.00388.2009] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Reabsorption of water and other molecules is dependent on the corticomedullary sodium concentration gradient in the kidney. During the early course of acute tubular necrosis (ATN), this gradient is altered. Therefore, 23Na magnetic resonance imaging (MRI) was used to study the alterations in renal sodium distribution in the rat kidney during ischemia and reperfusion (IR) injury, which induces ATN. In-magnet ischemia was induced for 0 (control), 10, 20, 30 or 50 min in Wistar rats. 23Na images were collected every 10 min during baseline, ischemia, and 60-min reperfusion periods. T1 and T2 relaxation times were measured by both 23Na-MRI and -MRS on a separate cohort of animals during ischemia and reperfusion for correction of relaxation-related tissue sodium concentration (TSC). A marked decrease was observed in the medulla and cortex 23Na-MRI signal intensity (SI) during the early evolution of ATN caused by IR injury, with the sodium reabsorption function of the kidney being irreversibly damaged after 50 min of ischemia. Sodium relaxation time characteristics were similar in the medulla and cortex of normal kidney, but significantly decreased with IR. The changes in relaxation times in both compartments were identical; thus the medulla-to-cortex sodium SI ratio represents the TSC ratio of both compartments. The extent of IR damage observed with histological examination correlated with the 23Na-MRI data. 23Na-MRI has great potential for noninvasive, clinical diagnosis of evolving ATN in the setup of acute renal failure and in differentiating ATN from other causes of renal failure where tubular function is maintained.
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Affiliation(s)
- Bharath K Atthe
- Department of Radiology, Indiana University-Purdue University at Indianapolis, Indianapolis, Indiana 46202-5181, USA
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Augath M, Heiler P, Kirsch S, Schad LR. In vivo(39)K, (23)Na and (1)H MR imaging using a triple resonant RF coil setup. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2009; 200:134-6. [PMID: 19501530 DOI: 10.1016/j.jmr.2009.05.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2009] [Revised: 05/04/2009] [Accepted: 05/15/2009] [Indexed: 05/09/2023]
Abstract
The maintenance of a gradient of potassium and sodium ions across the cell membranes is essential for the physiological function of the mammal organism. The measurement of the spatial distribution of pathologically changing ion concentrations of (23)Na and (39)K with magnetic resonance imaging offers a promising approach in clinical diagnostics to measure tissue viability. Existing studies were focused mainly on (23)Na imaging as well as spectroscopy with only one post-mortem study for (39)K imaging. In this paper a triple resonant RF coil setup for the rat head at 9.4T is presented for imaging of both nuclei ((23)Na and (39)K) and the acquisition of anatomical proton images in the same experiment without moving the subject or the RF coil. In vivo MR images of (39)K and (23)Na in the rat brain were acquired as well as anatomical proton images in the same scanning session.
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Affiliation(s)
- Mark Augath
- Computer Assisted Clinical Medicine, Faculty of Medicine Mannheim, University of Heidelberg, Mannheim, Germany.
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Ouwerkerk R, Bottomley PA, Solaiyappan M, Spooner AE, Tomaselli GF, Wu KC, Weiss RG. Tissue sodium concentration in myocardial infarction in humans: a quantitative 23Na MR imaging study. Radiology 2008; 248:88-96. [PMID: 18566171 DOI: 10.1148/radiol.2481071027] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To prospectively determine whether the absolute tissue sodium concentration (TSC) increases in myocardial infarctions (MIs) in humans and whether TSC is related to infarct size, infarct age, ventricular dysfunction, and/or electrophysiologic inducibility of ventricular arrhythmias. MATERIALS AND METHODS Delayed contrast material-enhanced 1.5-T hydrogen 1 ((1)H) magnetic resonance (MR) imaging was used to measure the size and location of nonacute MIs in 20 patients (18 men, two women; mean age, 63 years +/- 9 [standard deviation]; age range, 48-82 years) examined at least 90 days after MI. End-systolic and end-diastolic volumes, ejection fraction, and left ventricle (LV) mass were measured with cine MR imaging. The TSC in normal, infarcted, and adjacent myocardial tissue was measured on sodium 23 ((23)Na) MR images coregistered with delayed contrast-enhanced (1)H MR images. Programmed electric stimulation to induce monomorphic ventricular tachycardia (MVT) was used to assess arrhythmic potential, and myocardial TSC was compared between the inducible MVT and noninducible MVT patient groups. RESULTS The mean TSC for MIs (59 micromol/g wet weight +/- 10) was 30% higher than that for noninfarcted (remote) LV regions (45 micromol/g wet weight +/- 5, P < .001) and that for healthy control subjects, and TSC did not correlate with infarct age or functional and morphologic indices. The mean TSC for tissue adjacent to the MI (50 micromol/g wet weight +/- 6) was intermediate between that for the MI and that for remote regions. The elevated TSC measured in the MI at (23)Na MR imaging lacked sufficient contrast and spatial resolution for routine visualization of MI. Cardiac TSC did not enable differentiation between patients in whom MVT was inducible and those in whom it was not. CONCLUSION Absolute TSC is measurable with (23)Na MR imaging and is significantly elevated in human MI; however, TSC increase is not related to infarct age, infarct size, or global ventricular function. In regions adjacent to the MI, TSC is slightly increased but not to levels in the MI.
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Affiliation(s)
- Ronald Ouwerkerk
- Division of Magnetic Resonance Research, Department of Radiology, Johns Hopkins University, School of Medicine, 601 N Caroline St, JHOC 4241, Baltimore, MD 21287-0845, USA.
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Ouwerkerk R. Sodium magnetic resonance imaging: from research to clinical use. J Am Coll Radiol 2007; 4:739-41. [PMID: 17903762 PMCID: PMC2084082 DOI: 10.1016/j.jacr.2007.07.001] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2007] [Indexed: 11/26/2022]
Affiliation(s)
- Ronald Ouwerkerk
- Johns Hopkins University, School of Medicine, Division of MR Research, Russell H. Morgan Department of Radiology and Radiological Science, 601 N Caroline Street, JHOC 4241, Baltimore, MD 21287-0845, USA
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Milbrandt EB, Angus DC. Bench-to-bedside review: critical illness-associated cognitive dysfunction--mechanisms, markers, and emerging therapeutics. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2007; 10:238. [PMID: 17118217 PMCID: PMC1794449 DOI: 10.1186/cc5078] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Cognitive dysfunction is common in critically ill patients, not only during the acute illness but also long after its resolution. A large number of pathophysiologic mechanisms are thought to underlie critical illness-associated cognitive dysfunction, including neuro-transmitter abnormalities and occult diffuse brain injury. Markers that could be used to evaluate the influence of specific mechanisms in individual patients include serum anticholinergic activity, certain brain proteins, and tissue sodium concentration determination via high-resolution three-dimensional magnetic resonance imaging. Although recent therapeutic advances in this area are exciting, they are still too immature to influence patient care. Additional research is needed if we are to understand better the relative contributions of specific mechanisms to the development of critical illness-associated cognitive dysfunction and to determine whether these mechanisms might be amenable to treatment or prevention.
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Affiliation(s)
- Eric B Milbrandt
- CRISMA Laboratory, Department of Critical Care Medicine, University of Pittsburgh School of Medicine, 641 Scaife Hall, 3550 Terrace St, Pittsburgh, PA 15261, USA.
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Nielles-Vallespin S, Weber MA, Bock M, Bongers A, Speier P, Combs SE, Wöhrle J, Lehmann-Horn F, Essig M, Schad LR. 3D radial projection technique with ultrashort echo times for sodium MRI: clinical applications in human brain and skeletal muscle. Magn Reson Med 2007; 57:74-81. [PMID: 17191248 DOI: 10.1002/mrm.21104] [Citation(s) in RCA: 140] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
(23)Na MRI has the potential to noninvasively detect sodium (Na) content changes in vivo. The goal of this study was to implement (23)Na MRI in a clinical setting for neurooncological and muscular imaging. Due to the biexponential T(2) decay of the tissue Na signal with a short component, which ranges between 0.5-8 ms, the measurement of total Na content requires imaging techniques with echo times (TEs) below 0.5 ms. A 3D radial pulse sequence with a TE of 0.2 ms at a spatial resolution of 4 x 4 x 4 mm(3) was developed that allows the acquisition and presentation of Na images on the scanner. This sequence was evaluated in patients with low- and high-grade gliomas, and higher (23)Na MR signals corresponding to an increased Na content were found in the tumor regions. The contrast-to-noise ratio (CNR) between tumor and white matter increased from 0.8 +/- 0.2 to 1.3 +/- 0.3 with tumor grade. In patients with an identified muscular (23)Na channelopathy (Paramyotonia congenita (PC)), induced muscle weakness led to a signal increase of approximately 18% in the (23)Na MR images, which was attributed to intracellular Na(+) accumulation in this region.
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Maril N, Rosen Y, Reynolds GH, Ivanishev A, Ngo L, Lenkinski RE. Sodium MRI of the human kidney at 3 Tesla. Magn Reson Med 2007; 56:1229-34. [PMID: 17089361 DOI: 10.1002/mrm.21031] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The sodium concentration gradient in the kidney (from the cortex to the medulla) serves to regulate fluid homeostasis and is tightly coupled to renal function. It was previously shown that renal function and pathophysiology can be characterized in rat kidneys by measuring the sodium gradient with (23)Na MRI. This study demonstrates for the first time the ability of (23)Na MRI to map the distribution of sodium in the human kidney and to quantify the corticomedullary sodium gradient. The study was performed on a 3T Signa LX scanner (GE) using an in-house-built quadrature surface coil. (23)Na images of volunteers were acquired using a 3D coronal gradient-echo sequence at a spatial resolution of 0.3 x 0.3 x 1.5 cm(3) in a 25-min scan time. The signal intensity (relative to the noise) increased linearly from the cortex to each of the medullae with a mean slope of 1.6 +/- 0.2 in relative arbitrary units per mm (Rel.u./mm, N = 6) and then decreased, as expected, toward the renal pelvis. Water deprivation (12 hr) induced a significant increase of 25% (P < 0.05) in this gradient. Based on these results, we suggest that sodium MRI can serve as a valuable noninvasive method for functional imaging of the human kidney.
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Affiliation(s)
- Nimrod Maril
- Department of Radiology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts 02215, USA
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Borthakur A, Mellon E, Niyogi S, Witschey W, Kneeland JB, Reddy R. Sodium and T1rho MRI for molecular and diagnostic imaging of articular cartilage. NMR IN BIOMEDICINE 2006; 19:781-821. [PMID: 17075961 PMCID: PMC2896046 DOI: 10.1002/nbm.1102] [Citation(s) in RCA: 180] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
In this article, both sodium magnetic resonance (MR) and T1rho relaxation mapping aimed at measuring molecular changes in cartilage for the diagnostic imaging of osteoarthritis are reviewed. First, an introduction to structure of cartilage, its degeneration in osteoarthritis (OA) and an outline of diagnostic imaging methods in quantifying molecular changes and early diagnostic aspects of cartilage degeneration are described. The sodium MRI section begins with a brief overview of the theory of sodium NMR of biological tissues and is followed by a section on multiple quantum filters that can be used to quantify both bi-exponential relaxation and residual quadrupolar interaction. Specifically, (i) the rationale behind the use of sodium MRI in quantifying proteoglycan (PG) changes, (ii) validation studies using biochemical assays, (iii) studies on human OA specimens, (iv) results on animal models and (v) clinical imaging protocols are reviewed. Results demonstrating the feasibility of quantifying PG in OA patients and comparison with that in healthy subjects are also presented. The section concludes with the discussion of advantages and potential issues with sodium MRI and the impact of new technological advancements (e.g. ultra-high field scanners and parallel imaging methods). In the theory section on T1rho, a brief description of (i) principles of measuring T1rho relaxation, (ii) pulse sequences for computing T1rho relaxation maps, (iii) issues regarding radio frequency power deposition, (iv) mechanisms that contribute to T1rho in biological tissues and (v) effects of exchange and dipolar interaction on T1rho dispersion are discussed. Correlation of T1rho relaxation rate with macromolecular content and biomechanical properties in cartilage specimens subjected to trypsin and cytokine-induced glycosaminoglycan depletion and validation against biochemical assay and histopathology are presented. Experimental T1rho data from osteoarthritic specimens, animal models, healthy human subjects and as well from osteoarthritic patients are provided. The current status of T1rho relaxation mapping of cartilage and future directions is also discussed.
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Affiliation(s)
- Arijitt Borthakur
- MMRRCC, Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104-6100, USA
| | - Eric Mellon
- MMRRCC, Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104-6100, USA
| | - Sampreet Niyogi
- MMRRCC, Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104-6100, USA
| | - Walter Witschey
- MMRRCC, Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104-6100, USA
| | - J. Bruce Kneeland
- MMRRCC, Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104-6100, USA
| | - Ravinder Reddy
- MMRRCC, Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104-6100, USA
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Maril N, Margalit R, Rosen S, Heyman SN, Degani H. Detection of evolving acute tubular necrosis with renal 23Na MRI: studies in rats. Kidney Int 2006; 69:765-8. [PMID: 16518333 DOI: 10.1038/sj.ki.5000152] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The clinical detection of evolving acute tubular necrosis (ATN) and differentiating it from other causes of renal failure are currently limited. The maintenance of the corticomedullary sodium gradient, an indicator of normal kidney function, is presumably lost early in the course of ATN. Herein, sodium magnetic resonance imaging (23Na MRI) was applied to study the early alteration in renal sodium distribution in rat kidneys 6 h after the induction of ATN. Three-dimensional gradient echo sodium images were recorded at 4.7 T with high spatial resolution. ATN was produced by the administration of radiologic contrast medium, combined with inhibition of nitric oxide and prostaglandin synthesis. The sodium images revealed that the sham-controlled kidney exhibited a linear increase in sodium concentration along the corticomedullary axis of 30+/-2 mmol/l/mm, resulting in an inner medulla to cortex sodium ratio of 4.3+/-0.3 (n=5). In the ATN kidney, however, the cortico-outer medullary sodium gradient was reduced by 21% (P<0.01, n=7) and the inner medulla to cortex sodium ratio was decreased by 40% (P<0.001, n=7). Small, though significant, increments in plasma creatinine at this time inversely correlated with the decline in the corticomedullary sodium gradient. Histological findings demonstrated outer medullary ATN involving 4% of medullary thick ascending limbs. Hence, 23Na MRI non-invasively quantified changes in the corticomedullary sodium gradient in the ATN kidney when morphologic tubular injury was still focal and very limited. MRI detection of corticomedullary sodium gradient abnormalities may serve to identify evolving ATN at its early phases.
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Affiliation(s)
- N Maril
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
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44
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Milbrandt EB, Angus DC. Potential mechanisms and markers of critical illness-associated cognitive dysfunction. Curr Opin Crit Care 2006; 11:355-9. [PMID: 16015116 DOI: 10.1097/01.ccx.0000170508.63067.04] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
PURPOSE OF REVIEW To review the current understanding of the potential mechanisms of critical illness-associated cognitive dysfunction and to provide insight into markers that could be used to evaluate the influence of specific mechanisms in individual patients. RECENT FINDINGS Cognitive dysfunction is common in critically ill patients, not only during the acute illness but also long after its resolution. Several pathophysiologic mechanisms are thought to underlie critical illness-associated cognitive dysfunction, including neurotransmitter abnormalities and occult diffuse brain injury. Markers that could be used to evaluate the influence of specific mechanisms in individual patients include serum anticholinergic activity, certain brain proteins, and tissue sodium concentration determination by way of high-resolution three-dimensional magnetic resonance imaging. SUMMARY Although recent advances in this area are exciting, they are still too immature to influence patient care. Additional research is needed to provide a better understanding of the relative contribution of specific mechanisms to the development of critical illness-associated cognitive dysfunction and to determine whether these mechanisms might be amenable to treatment or prevention.
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Affiliation(s)
- Eric B Milbrandt
- The CRISMA Laboratory (Clinical Research, Investigation, and Systems Modeling of Acute Illness), Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA.
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45
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Ouwerkerk R, Weiss RG, Bottomley PA. Measuring human cardiac tissue sodium concentrations using surface coils, adiabatic excitation, and twisted projection imaging with minimal T2 losses. J Magn Reson Imaging 2005; 21:546-55. [PMID: 15834912 DOI: 10.1002/jmri.20322] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
PURPOSE To measure tissue sodium concentrations in the human heart with (23)Na MRI using a surface coil, thereby eliminating the effects of inhomogeneous excitation by surface coils and minimizing T(1) and T(2) relaxation. MATERIALS AND METHODS We combined fully relaxed, very short-echo, (23)Na twisted projection imaging (TPI) with adiabatic half passage (AHP) excitation and external referencing on subjects and comparing with a concentration reference phantom scan to quantify TSC with surface coils. (23)Na signal losses during hard (square), composite, and tanh/tan amplitude/frequency-modulated AHP excitation pulses were analyzed over a wide range of RF field strengths and T(2short) values. RESULTS AHP excitation yielded a homogeneous excitation flip angle and negligible losses compared to a 90 degrees hard pulse wherever the B1 field exceeded the adiabatic threshold, rendering this sequence suitable for applications that use surface coil excitation. An AHP (23)Na TPI sequence was used with a surface coil at 1.5 T to noninvasively quantify myocardial TSC in 10 normal volunteers. The mean TSC was 43 +/- 4, 53 +/- 12, and 17 +/- 4 micromol/g in the left ventricular (LV) free wall, septum, and adipose tissue, respectively, consistent with prior invasive measurements on biopsy and autopsy specimens. CONCLUSION It is now possible to noninvasively quantify TSC in the human heart with surface coil (23)Na MRI.
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Affiliation(s)
- Ronald Ouwerkerk
- Division of MR Research, Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287-0845, USA.
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46
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Maril N, Margalit R, Mispelter J, Degani H. Sodium magnetic resonance imaging of diuresis: spatial and kinetic response. Magn Reson Med 2005; 53:545-52. [PMID: 15723399 DOI: 10.1002/mrm.20359] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Renal function is highly correlated with the sodium concentration gradient along the corticomedullary axis. The application of 3D high-resolution sodium magnetic resonance imaging (MRI) provided a means to quantify in vivo the spatial and temporal changes in renal tissue sodium concentration under normal and diuretic conditions. A detailed, pixel-by-pixel analysis of the intact rat kidney sodium MR images yielded a quantitative measure of the corticomedullary sodium gradient before and at early and later times after the administration of two distinct diuretic agents, furosemide and mannitol. Furosemide, a loop diuretic, induced a fivefold reduction in the cortical-outer medullary sodium gradient, whereas mannitol, an osmotic diuretic, did not affect this gradient. Both diuretics induced a 50% decrease in the sodium concentration of the inner medulla; however, mannitol exerted its effect twice as fast as furosemide with a 2.5-min exponential decay constant. These specific changes were attributed to the different mechanism of action and site of activity of each diuretic agent. Thus, high-resolution (23)Na MRI offers a unique, noninvasive tool for functional imaging of the kidney physiology.
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Affiliation(s)
- Nimrod Maril
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot 76100, Israel
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Hillenbrand HB, Becker LC, Kharrazian R, Hu K, Rochitte CE, Kim RJ, Chen EL, Ertl G, Hruban RH, Lima JAC. 23Na MRI combined with contrast-enhanced1H MRI provides in vivo characterization of infarct healing. Magn Reson Med 2005; 53:843-50. [PMID: 15799052 DOI: 10.1002/mrm.20417] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Although (23)Na MRI has been shown to delineate acute myocardial infarction (MI), the time course of in vivo (23)Na MRI during infarct healing remains unknown. In this study (23)Na MRI was combined with contrast-enhanced (CE) (1)H MRI to noninvasively characterize infarct healing in vivo. Serial in vivo 3D (23)Na MRI and (1)H MRI were performed for up to 9 weeks postinfarction in 10 dogs. Radioactive microspheres were used to measure myocardial perfusion, and Hematoxylin-Eosin (H&E) and Masson's trichrome (MT) staining were used to assess interstitial cell infiltrate and collagen content. In vivo (23)Na MRI accurately delineated infarct size up to day 5 postinfarction in comparison with (1)H MRI (8.9% +/- 8.1% vs. 8.6% +/- 7.9% on day 1 postinfarction, P = NS; and 6.3% +/- 6.2% vs. 6.2% +/- 6.2% on days 4/5 postinfarction, P = NS). The in vivo (23)Na MRI signal intensity, expressed as the signal intensity ratio of infarcted tissue vs. noninfarcted tissue (MI/R) peaked on day 1 of infarction (2.04 +/- 0.23) but decreased significantly to 1.27 at 9 weeks postinfarction (P < 0.05) due to granulation tissue infiltrate and collagen deposition. To confirm the MI/R decrease during scar formation ex vivo, we performed (23)Na MRI in 12 rats on day 3 post-MI (N = 5) and after 6 weeks (N = 7). H&E and Picrosirius Red staining confirmed granulation tissue infiltrate on day 3 and scar formation after 6 weeks. MI/R decreased significantly from 1.91 +/- 0.45 on day 3 post-MI to 1.3 +/- 0.09 after 6 weeks. Thus, in vivo (23)Na MRI accurately delineates infarct size up to day 5 postinfarction. In vivo (23)Na MRI signal intensity decreases during infarct healing as a result of the underlying infarct healing process.
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Abstract
A fundamental modification to the conventional chemical shift imaging (CSI) method is described that improves the imaging of species with short T2's (i.e., less than approximately 2 ms). This approach minimizes the delay before each k-space point is collected. This results in different time delays, T(d), for different free induction decay (FID) acquisitions in k-space. On a clinical 1.5 T system this yields an effective delay due to transmit/receive switching of 70 micros and an echo time (TE) from the center of the excitation pulse to the center of k-space of 170 micros, as compared with 1-2 ms for conventional CSI techniques. Using this method, the signal decay before acquisition is greatly reduced, thus enabling imaging of species with very short T2)(e.g., 200 micros) and increasing the signal-to-noise ratio (SNR) of species with intermediate T2. Increases in the SNR of the short T2 components of 23Na in the heart, and 31P acquisitions of bone are about 27% and 400%, respectively, compared to an optimized conventional CSI approach. The imperfections of this approach are also described, and the magnitude of the resultant image artifacts is quantified for different practical imaging situations. These artifacts were not found to be significant in the described applications. This new method allows us to obtain information on short T2 components without degrading the image quality from long T2 components.
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Affiliation(s)
- Matthew D Robson
- University of Oxford Centre for Clinical Magnetic Resonance Research, MRS Unit, John Radcliffe Hospital, Oxford, UK.
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Neuberger T, Greiser A, Nahrendorf M, Jakob PM, Faber C, Webb AG. 23Na microscopy of the mouse heart in vivo using density-weighted chemical shift imaging. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2004; 17:196-200. [PMID: 15580377 DOI: 10.1007/s10334-004-0048-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2004] [Revised: 06/18/2004] [Accepted: 07/02/2004] [Indexed: 10/26/2022]
Abstract
The mouse has become an important animal model for human cardiac disease, and the development of techniques for non-invasive imaging of the mouse heart in vivo is, therefore, of great potential interest. Previous magnetic resonance imaging studies have concentrated on pathologically induced changes in cardiac structure and dynamics by acquiring proton images. Further information can be gained by studying cardiac function and physiology using other nuclei, for example, sodium. Sodium imaging of such a small structure presents considerable technical challenges. In this work we show the first sodium images of the mouse heart, with an isotropic spatial resolution of 1 x 1 x 1 mm, acquired in a time of 1.5 h. The ventricles, septum and myocardium are readily distinguishable in these images, which were acquired through the combination of 3D density-weighted chemical shift imaging, optimized instrumentation, and a high magnetic field strength (17.6 T). Measurements of the myocardial:blood sodium concentration in the left and right ventricles agree well with theoretical values.
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Affiliation(s)
- T Neuberger
- Department of Physics, EP5 (Biophysics), University of Würzburg, Am Hubland, 97074, Würzburg, Germany.
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50
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Jansen MA, Van Emous JG, Nederhoff MGJ, Van Echteld CJA. Assessment of myocardial viability by intracellular 23Na magnetic resonance imaging. Circulation 2004; 110:3457-64. [PMID: 15557379 DOI: 10.1161/01.cir.0000148132.15105.0e] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Because of rapid changes in myocardial intracellular Na+ (Na+(i)) during ischemia and reperfusion (R), 23Na magnetic resonance imaging (MRI) appears to be an ideal diagnostic modality for early detection of myocardial ischemia and viability. So far, cardiac 23Na MRI data are limited and mostly concerned with imaging of total Na+. For proper interpretation, imaging of both Na+(i) and extracellular Na+ is essential. In this study, we tested whether Na+(i) imaging can be used to assess viability after low-flow (LF) ischemia. METHODS AND RESULTS Isolated rat hearts were subjected to LF (1%, 2%, or 3% of control coronary flow) and R. A shift reagent was used to separate Na+(i) and extracellular Na+ resonances. Acquisition-weighted 23Na chemical shift imaging (CSI) was alternated with 23Na MR spectroscopy. Already during control perfusion, Na+(i) could be clearly seen on the images. Na+(i) image intensity increased with increasing severity of ischemia. During R, Na+(i) image intensity remained highest in 1% LF hearts. Not only did we find very good correlations between Na+(i) image intensity at end-R and end-diastolic pressure (R=0.85, P<0.001) and recovery of the rate-pressure product (R=-0.88, P<0.001) at end-R, but most interestingly, also Na+(i) image intensity at end-LF was well correlated with end-diastolic pressure (R=0.78, P<0.01) and with recovery of the rate-pressure product (R=-0.81, P<0.01) at end-R. Furthermore, Na+(i) image intensity at end-LF was well correlated with creatine kinase release during R (R=0.79, P<0.05) as well as with infarct size (R=0.77, P<0.05). CONCLUSIONS These data indicate that 23Na CSI is a promising tool for the assessment of myocardial viability.
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Affiliation(s)
- Maurits A Jansen
- University Medical Center, Heart Lung Center Utrecht, NMR Laboratory, Utrecht, The Netherlands
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