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Groschup B, Calandra GM, Raitmayr C, Shrouder J, Llovera G, Zaki AG, Burgstaller S, Bischof H, Eroglu E, Liesz A, Malli R, Filser S, Plesnila N. Probing intracellular potassium dynamics in neurons with the genetically encoded sensor lc-LysM GEPII 1.0 in vitro and in vivo. Sci Rep 2024; 14:13753. [PMID: 38877089 PMCID: PMC11178854 DOI: 10.1038/s41598-024-62993-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Accepted: 05/23/2024] [Indexed: 06/16/2024] Open
Abstract
Neuronal activity is accompanied by a net outflow of potassium ions (K+) from the intra- to the extracellular space. While extracellular [K+] changes during neuronal activity are well characterized, intracellular dynamics have been less well investigated due to lack of respective probes. In the current study we characterized the FRET-based K+ biosensor lc-LysM GEPII 1.0 for its capacity to measure intracellular [K+] changes in primary cultured neurons and in mouse cortical neurons in vivo. We found that lc-LysM GEPII 1.0 can resolve neuronal [K+] decreases in vitro during seizure-like and intense optogenetically evoked activity. [K+] changes during single action potentials could not be recorded. We confirmed these findings in vivo by expressing lc-LysM GEPII 1.0 in mouse cortical neurons and performing 2-photon fluorescence lifetime imaging. We observed an increase in the fluorescence lifetime of lc-LysM GEPII 1.0 during periinfarct depolarizations, which indicates a decrease in intracellular neuronal [K+]. Our findings suggest that lc-LysM GEPII 1.0 can be used to measure large changes in [K+] in neurons in vitro and in vivo but requires optimization to resolve smaller changes as observed during single action potentials.
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Affiliation(s)
- Bernhard Groschup
- Institute for Stroke and Dementia Research (ISD), LMU University Hospital, LMU Munich, Munich, Germany
- Graduate School of Systemic Neurosciences, LMU Munich, Planegg-Martinsried, Germany
| | - Gian Marco Calandra
- Institute for Stroke and Dementia Research (ISD), LMU University Hospital, LMU Munich, Munich, Germany
- Graduate School of Systemic Neurosciences, LMU Munich, Planegg-Martinsried, Germany
| | - Constanze Raitmayr
- Institute for Stroke and Dementia Research (ISD), LMU University Hospital, LMU Munich, Munich, Germany
| | - Joshua Shrouder
- Institute for Stroke and Dementia Research (ISD), LMU University Hospital, LMU Munich, Munich, Germany
| | - Gemma Llovera
- Institute for Stroke and Dementia Research (ISD), LMU University Hospital, LMU Munich, Munich, Germany
| | - Asal Ghaffari Zaki
- Regenerative and Restorative Medicine Research Center (REMER), Research Institute for Health Sciences and Technologies (SABITA), Istanbul Medipol University, Istanbul, Turkey
- Molecular Biology, Genetics and Bioengineering Program, Faculty of Engineering and Natural Sciences, Sabanci University, Istanbul, Turkey
| | - Sandra Burgstaller
- Institut für Klinische Anatomie und Zellanalytik (Österbergstraße 3), Eberhard Karls Universität Tübingen, Tübingen, Germany
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/4, 8010, Graz, Austria
| | - Helmut Bischof
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/4, 8010, Graz, Austria
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tübingen, Auf der Morgenstelle 8, 72076, Tübingen, Germany
| | - Emrah Eroglu
- Regenerative and Restorative Medicine Research Center (REMER), Research Institute for Health Sciences and Technologies (SABITA), Istanbul Medipol University, Istanbul, Turkey
- Molecular Biology, Genetics and Bioengineering Program, Faculty of Engineering and Natural Sciences, Sabanci University, Istanbul, Turkey
| | - Arthur Liesz
- Institute for Stroke and Dementia Research (ISD), LMU University Hospital, LMU Munich, Munich, Germany
- Graduate School of Systemic Neurosciences, LMU Munich, Planegg-Martinsried, Germany
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Roland Malli
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/4, 8010, Graz, Austria
- BioTechMed-Graz, Mozartgasse 12/II, 8010, Graz, Austria
| | - Severin Filser
- Institute for Stroke and Dementia Research (ISD), LMU University Hospital, LMU Munich, Munich, Germany
- Deutsches Zentrum Für Neurodegenerative Erkrankungen (DZNE), Light Microscope Facility (LMF), Bonn, Germany
| | - Nikolaus Plesnila
- Institute for Stroke and Dementia Research (ISD), LMU University Hospital, LMU Munich, Munich, Germany.
- Graduate School of Systemic Neurosciences, LMU Munich, Planegg-Martinsried, Germany.
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tübingen, Auf der Morgenstelle 8, 72076, Tübingen, Germany.
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Theillet FX, Luchinat E. In-cell NMR: Why and how? PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2022; 132-133:1-112. [PMID: 36496255 DOI: 10.1016/j.pnmrs.2022.04.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 04/19/2022] [Accepted: 04/27/2022] [Indexed: 06/17/2023]
Abstract
NMR spectroscopy has been applied to cells and tissues analysis since its beginnings, as early as 1950. We have attempted to gather here in a didactic fashion the broad diversity of data and ideas that emerged from NMR investigations on living cells. Covering a large proportion of the periodic table, NMR spectroscopy permits scrutiny of a great variety of atomic nuclei in all living organisms non-invasively. It has thus provided quantitative information on cellular atoms and their chemical environment, dynamics, or interactions. We will show that NMR studies have generated valuable knowledge on a vast array of cellular molecules and events, from water, salts, metabolites, cell walls, proteins, nucleic acids, drugs and drug targets, to pH, redox equilibria and chemical reactions. The characterization of such a multitude of objects at the atomic scale has thus shaped our mental representation of cellular life at multiple levels, together with major techniques like mass-spectrometry or microscopies. NMR studies on cells has accompanied the developments of MRI and metabolomics, and various subfields have flourished, coined with appealing names: fluxomics, foodomics, MRI and MRS (i.e. imaging and localized spectroscopy of living tissues, respectively), whole-cell NMR, on-cell ligand-based NMR, systems NMR, cellular structural biology, in-cell NMR… All these have not grown separately, but rather by reinforcing each other like a braided trunk. Hence, we try here to provide an analytical account of a large ensemble of intricately linked approaches, whose integration has been and will be key to their success. We present extensive overviews, firstly on the various types of information provided by NMR in a cellular environment (the "why", oriented towards a broad readership), and secondly on the employed NMR techniques and setups (the "how", where we discuss the past, current and future methods). Each subsection is constructed as a historical anthology, showing how the intrinsic properties of NMR spectroscopy and its developments structured the accessible knowledge on cellular phenomena. Using this systematic approach, we sought i) to make this review accessible to the broadest audience and ii) to highlight some early techniques that may find renewed interest. Finally, we present a brief discussion on what may be potential and desirable developments in the context of integrative studies in biology.
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Affiliation(s)
- Francois-Xavier Theillet
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198 Gif-sur-Yvette, France.
| | - Enrico Luchinat
- Dipartimento di Scienze e Tecnologie Agro-Alimentari, Alma Mater Studiorum - Università di Bologna, Piazza Goidanich 60, 47521 Cesena, Italy; CERM - Magnetic Resonance Center, and Neurofarba Department, Università degli Studi di Firenze, 50019 Sesto Fiorentino, Italy
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3
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James AD, Leslie TK, Kaggie JD, Wiggins L, Patten L, Murphy O'Duinn J, Langer S, Labarthe MC, Riemer F, Baxter G, McLean MA, Gilbert FJ, Kennerley AJ, Brackenbury WJ. Sodium accumulation in breast cancer predicts malignancy and treatment response. Br J Cancer 2022; 127:337-349. [PMID: 35462561 PMCID: PMC9296657 DOI: 10.1038/s41416-022-01802-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2021] [Revised: 03/10/2022] [Accepted: 03/22/2022] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Breast cancer remains a leading cause of death in women and novel imaging biomarkers are urgently required. Here, we demonstrate the diagnostic and treatment-monitoring potential of non-invasive sodium (23Na) MRI in preclinical models of breast cancer. METHODS Female Rag2-/- Il2rg-/- and Balb/c mice bearing orthotopic breast tumours (MDA-MB-231, EMT6 and 4T1) underwent MRI as part of a randomised, controlled, interventional study. Tumour biology was probed using ex vivo fluorescence microscopy and electrophysiology. RESULTS 23Na MRI revealed elevated sodium concentration ([Na+]) in tumours vs non-tumour regions. Complementary proton-based diffusion-weighted imaging (DWI) linked elevated tumour [Na+] to increased cellularity. Combining 23Na MRI and DWI measurements enabled superior classification accuracy of tumour vs non-tumour regions compared with either parameter alone. Ex vivo assessment of isolated tumour slices confirmed elevated intracellular [Na+] ([Na+]i); extracellular [Na+] ([Na+]e) remained unchanged. Treatment with specific inward Na+ conductance inhibitors (cariporide, eslicarbazepine acetate) did not affect tumour [Na+]. Nonetheless, effective treatment with docetaxel reduced tumour [Na+], whereas DWI measures were unchanged. CONCLUSIONS Orthotopic breast cancer models exhibit elevated tumour [Na+] that is driven by aberrantly elevated [Na+]i. Moreover, 23Na MRI enhances the diagnostic capability of DWI and represents a novel, non-invasive biomarker of treatment response with superior sensitivity compared to DWI alone.
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Affiliation(s)
- Andrew D James
- Department of Biology, University of York, York, UK
- York Biomedical Research Institute, University of York, York, UK
| | | | - Joshua D Kaggie
- Department of Radiology & NIHR Cambridge Biomedical Research Centre, University of Cambridge, Cambridge, UK
| | | | - Lewis Patten
- Department of Mathematics, University of York, York, UK
| | | | - Swen Langer
- Bioscience Technology Facility, Department of Biology, University of York, York, UK
| | | | - Frank Riemer
- Mohn Medical Imaging and Visualization Centre, Haukeland University Hospital Bergen, Bergen, Norway
| | - Gabrielle Baxter
- Department of Radiology & NIHR Cambridge Biomedical Research Centre, University of Cambridge, Cambridge, UK
| | - Mary A McLean
- Department of Radiology & NIHR Cambridge Biomedical Research Centre, University of Cambridge, Cambridge, UK
| | - Fiona J Gilbert
- Department of Radiology & NIHR Cambridge Biomedical Research Centre, University of Cambridge, Cambridge, UK
| | - Aneurin J Kennerley
- York Biomedical Research Institute, University of York, York, UK
- Department of Chemistry, University of York, York, UK
| | - William J Brackenbury
- Department of Biology, University of York, York, UK.
- York Biomedical Research Institute, University of York, York, UK.
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Zeng C, Chen Z, Yang H, Fan Y, Fei L, Chen X, Zhang M. Advanced high resolution three-dimensional imaging to visualize the cerebral neurovascular network in stroke. Int J Biol Sci 2022; 18:552-571. [PMID: 35002509 PMCID: PMC8741851 DOI: 10.7150/ijbs.64373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 10/28/2021] [Indexed: 11/05/2022] Open
Abstract
As an important method to accurately and timely diagnose stroke and study physiological characteristics and pathological mechanism in it, imaging technology has gone through more than a century of iteration. The interaction of cells densely packed in the brain is three-dimensional (3D), but the flat images brought by traditional visualization methods show only a few cells and ignore connections outside the slices. The increased resolution allows for a more microscopic and underlying view. Today's intuitive 3D imagings of micron or even nanometer scale are showing its essentiality in stroke. In recent years, 3D imaging technology has gained rapid development. With the overhaul of imaging mediums and the innovation of imaging mode, the resolution has been significantly improved, endowing researchers with the capability of holistic observation of a large volume, real-time monitoring of tiny voxels, and quantitative measurement of spatial parameters. In this review, we will summarize the current methods of high-resolution 3D imaging applied in stroke.
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Affiliation(s)
- Chudai Zeng
- Department of Neurology, Xiangya Hospital of Central South University, Changsha, Hunan, China, 410008.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China, 410008
| | - Zhuohui Chen
- Department of Neurology, Xiangya Hospital of Central South University, Changsha, Hunan, China, 410008.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China, 410008
| | - Haojun Yang
- Department of Neurology, Xiangya Hospital of Central South University, Changsha, Hunan, China, 410008.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China, 410008
| | - Yishu Fan
- Department of Neurology, Xiangya Hospital of Central South University, Changsha, Hunan, China, 410008.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China, 410008
| | - Lujing Fei
- Department of Neurology, Xiangya Hospital of Central South University, Changsha, Hunan, China, 410008.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China, 410008
| | - Xinghang Chen
- Department of Neurology, Xiangya Hospital of Central South University, Changsha, Hunan, China, 410008.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China, 410008
| | - Mengqi Zhang
- Department of Neurology, Xiangya Hospital of Central South University, Changsha, Hunan, China, 410008.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China, 410008
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5
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Zhao AJ, Liu BC, Gao CY, Quan DZ, Xia EL, Zhang FX. Evaluation of high-dielectric pads for macaque brain imaging at 7 T. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2021; 92:104101. [PMID: 34717383 DOI: 10.1063/5.0057847] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 09/08/2021] [Indexed: 06/13/2023]
Abstract
A non-human primate is a valuable model for investigating the structure and function of the brain. Different from the human brain imaging using radio frequency (RF) head coils, in the present study, on a human whole-body 7 T magnetic resonance imaging system, we used an RF knee coil for monkey brain imaging in vivo due to the smaller size of the macaque's brain compared to that of a human, and particularly, high-dielectric pads were also utilized in order to improve brain imaging performance. Our experimental results suggest that high-dielectric pads can effectively enhance the B1 field strength and receive sensitivity, leading to a higher flip-angle magnitude, an image signal-to-noise ratio, and tissue contrast, and in the meantime, we did not observe elevated receive array element coupling and receive noise amplification nor apparent magnetic susceptibility-induced artifact or distortion, showing that the pads do not introduce adverse RF interferences in macaque brain imaging at 7 T.
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Affiliation(s)
- A Jie Zhao
- Key Laboratory for Biomedical Engineering of Ministry of Education, Zhejiang University, Hangzhou 310027, China
| | - B Chunyi Liu
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection & School for Radiological and Interdisciplinary Sciences (RAD-X), Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Soochow University, Suzhou 215123, China
| | - C Yang Gao
- Interdisciplinary Institute of Neuroscience and Technology, School of Medicine, Zhejiang University, Hangzhou 310029, China
| | - D Zhiyan Quan
- Interdisciplinary Institute of Neuroscience and Technology, School of Medicine, Zhejiang University, Hangzhou 310029, China
| | - E Ling Xia
- Key Laboratory for Biomedical Engineering of Ministry of Education, Zhejiang University, Hangzhou 310027, China
| | - F Xiaotong Zhang
- Key Laboratory for Biomedical Engineering of Ministry of Education, Zhejiang University, Hangzhou 310027, China
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Tan JWY, Folz J, Kopelman R, Wang X. In vivo photoacoustic potassium imaging of the tumor microenvironment. BIOMEDICAL OPTICS EXPRESS 2020; 11:3507-3522. [PMID: 33014547 PMCID: PMC7510904 DOI: 10.1364/boe.393370] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 05/08/2020] [Accepted: 05/11/2020] [Indexed: 05/19/2023]
Abstract
The accumulation of potassium (K+) in the tumor microenvironment (TME) has been recently shown to inhibit immune cell efficacy, and thus immunotherapy. Despite the abundance of K+ in the body, few ways exist to measure it in vivo. To address this technology gap, we combine an optical K+ nanosensor with photoacoustic (PA) imaging. Using multi-wavelength deconvolution, we are able to quantitatively evaluate the TME K+ concentration in vivo, and its distribution. Significantly elevated K+ levels were found in the TME, with an average concentration of approximately 29 mM, compared to 19 mM found in muscle. These PA measurements were confirmed by extraction of the tumor interstitial fluid and subsequent measurement via inductively coupled plasma mass spectrometry.
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Affiliation(s)
- Joel W Y Tan
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA
- These authors contributed equally to this work
| | - Jeff Folz
- Biophysics Program, University of Michigan, Ann Arbor, Michigan 48109, USA
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA
- These authors contributed equally to this work
| | - Raoul Kopelman
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA
- Biophysics Program, University of Michigan, Ann Arbor, Michigan 48109, USA
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Xueding Wang
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA
- Department of Radiology, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA
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Sánchez-Heredia JD, Baron R, Hansen ESS, Laustsen C, Zhurbenko V, Ardenkjaer-Larsen JH. Autonomous cryogenic RF receive coil for 13 C imaging of rodents at 3 T. Magn Reson Med 2019; 84:497-508. [PMID: 31782552 DOI: 10.1002/mrm.28113] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Revised: 10/15/2019] [Accepted: 11/14/2019] [Indexed: 12/26/2022]
Abstract
PURPOSE To develop an autonomous, in-bore, MR-compatible cryostat cooled with liquid nitrogen that provides full-day operation, and to demonstrate that the theoretical signal-to-noise benefit can be achieved for 13 C imaging at 3 T (32.13 MHz). METHODS The cryogenic setup uses a vacuum-insulated fiberglass cryostat, which indirectly cools a cold finger where the RF coil is attached. The cryostat was evacuated before use and had a reservoir of liquid nitrogen for full-day operation. A 30 × 40 mm2 copper coil was mounted inside the cryostat with a 3-mm distance to the sample. Two examples of in vivo experiments of rat brain metabolism after a hyperpolarized [1-13 C]pyruvate injection are reported. RESULTS A coil Q-factor ratio of Q88K /Q290K = 550/280 was obtained, and the theoretical SNR enhancement was verified with MR measurements. We achieved a coil temperature of 88 K and a preamplifier temperature of 77 K. A 2-fold overall SNR enhancement was achieved, compared with the best case at room temperature. The thermal performance of the coil was adequate for in vivo experiments, with an autonomy of 5 hours consuming 6 L of LN2 , extendable to over 12 hours by LN2 refilling. CONCLUSION Cryogenic surface coils can be highly beneficial for 13 C imaging, provided that the coil-to-sample distance remains short. An autonomous, in-bore cryostat was developed that achieved the theoretical improvement in SNR.
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Affiliation(s)
| | - Rafael Baron
- Department of Health Technology, Technical University of Denmark, Kongens Lyngby, Denmark
| | | | - Christoffer Laustsen
- MR Research Center, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Vitaliy Zhurbenko
- Department of Electrical Engineering, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Jan Henrik Ardenkjaer-Larsen
- Department of Health Technology, Technical University of Denmark, Kongens Lyngby, Denmark.,GE Healthcare, Brøndbyvester, Denmark
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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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9
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Lee CH, Folz J, Tan JWY, Jo J, Wang X, Kopelman R. Chemical Imaging in Vivo: Photoacoustic-Based 4-Dimensional Chemical Analysis. Anal Chem 2019; 91:2561-2569. [DOI: 10.1021/acs.analchem.8b04797] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Chang H. Lee
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Jeff Folz
- Biophysics Program, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Joel W. Y. Tan
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Janggun Jo
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Xueding Wang
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Raoul Kopelman
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
- Biophysics Program, University of Michigan, Ann Arbor, Michigan 48109, United States
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States
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10
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Budinger TF, Bird MD. MRI and MRS of the human brain at magnetic fields of 14 T to 20 T: Technical feasibility, safety, and neuroscience horizons. Neuroimage 2018; 168:509-531. [DOI: 10.1016/j.neuroimage.2017.01.067] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Revised: 01/23/2017] [Accepted: 01/27/2017] [Indexed: 11/16/2022] Open
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11
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Sanchez-Heredia JD, Szocska Hansen ES, Laustsen C, Zhurbenko V, Ardenkjær-Larsen JH. Low-Noise Active Decoupling Circuit and its Application to 13C Cryogenic RF Coils at 3 T. ACTA ACUST UNITED AC 2017; 3:60-66. [PMID: 30042972 PMCID: PMC6024423 DOI: 10.18383/j.tom.2016.00280] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
We analyze the loss contributions in a small, 50-mm-diameter receive-only coil for carbon-13 (13C) magnetic resonance imaging at 3 T for 3 different circuits, which, including active decoupling, are compared in terms of their Q-factors and signal-to-noise ratio (SNR). The results show that a circuit using unsegmented tuning and split matching capacitors can provide >20% SNR enhancement at room temperature compared with that using more traditional designs. The performance of the proposed circuit was also measured when cryogenically cooled to 105 K, and an additional 1.6-fold SNR enhancement was achieved on a phantom. The enhanced circuit performance is based on the low capacitance needed to match to 50 Ω when coil losses are low, which significantly reduces the proportion of the current flowing through the matching network and therefore minimizes this loss contribution. This effect makes this circuit particularly suitable for receive-only cryogenic coils and/or small coils for low-gamma nuclei.
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Affiliation(s)
- Juan Diego Sanchez-Heredia
- Department of Electrical Engineering, Technical University of Denmark, Kongens Lyngby, Copenhagen, Denmark and
| | | | - Christoffer Laustsen
- MR Research Centre, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Vitaliy Zhurbenko
- Department of Electrical Engineering, Technical University of Denmark, Kongens Lyngby, Copenhagen, Denmark and
| | - Jan Henrik Ardenkjær-Larsen
- Department of Electrical Engineering, Technical University of Denmark, Kongens Lyngby, Copenhagen, Denmark and
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12
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Nagel AM, Umathum R, Rösler MB, Ladd ME, Litvak I, Gor'kov PL, Brey WW, Schepkin VD. (39) K and (23) Na relaxation times and MRI of rat head at 21.1 T. NMR IN BIOMEDICINE 2016; 29:759-766. [PMID: 27061712 DOI: 10.1002/nbm.3528] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Revised: 03/01/2016] [Accepted: 03/02/2016] [Indexed: 06/05/2023]
Abstract
At ultrahigh magnetic field strengths (B0 ≥ 7.0 T), potassium ((39) K) MRI might evolve into an interesting tool for biomedical research. However, (39) K MRI is still challenging because of the low NMR sensitivity and short relaxation times. In this work, we demonstrated the feasibility of (39) K MRI at 21.1 T, determined in vivo relaxation times of the rat head at 21.1 T, and compared (39) K and sodium ((23) Na) relaxation times of model solutions containing different agarose gel concentrations at 7.0 and 21.1 T. (39) K relaxation times were markedly shorter than those of (23) Na. Compared with the lower field strength, (39) K relaxation times were up to 1.9- (T1 ), 1.4- (T2S ) and 1.9-fold (T2L ) longer at 21.1 T. The increase in the (23) Na relaxation times was less pronounced (up to 1.2-fold). Mono-exponential fits of the (39) K longitudinal relaxation time at 21.1 T revealed T1 = 14.2 ± 0.1 ms for the healthy rat head. The (39) K transverse relaxation times were 1.8 ± 0.2 ms and 14.3 ± 0.3 ms for the short (T2S ) and long (T2L ) components, respectively. (23) Na relaxation times were markedly longer (T1 = 41.6 ± 0.4 ms; T2S = 4.9 ± 0.2 ms; T2L = 33.2 ± 0.2 ms). (39) K MRI of the healthy rat head could be performed with a nominal spatial resolution of 1 × 1 × 1 mm(3) within an acquisition time of 75 min. The increase in the relaxation times with magnetic field strength is beneficial for (23) Na and (39) K MRI at ultrahigh magnetic field strength. Our results demonstrate that (39) K MRI at 21.1 T enables acceptable image quality for preclinical research. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Armin M Nagel
- German Cancer Research Center (DKFZ), Division of Medical Physics in Radiology, Heidelberg, Germany
- University Medical Center Ulm, Department of Diagnostic and Interventional Radiology, Ulm, Germany
| | - Reiner Umathum
- German Cancer Research Center (DKFZ), Division of Medical Physics in Radiology, Heidelberg, Germany
| | - Manuela B Rösler
- German Cancer Research Center (DKFZ), Division of Medical Physics in Radiology, Heidelberg, Germany
| | - Mark E Ladd
- German Cancer Research Center (DKFZ), Division of Medical Physics in Radiology, Heidelberg, Germany
| | - Ilya Litvak
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, USA
| | - Peter L Gor'kov
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, USA
| | - William W Brey
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, USA
| | - Victor D Schepkin
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL, USA
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