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Villarreal CX, Shen X, Alhulail AA, Buffo NM, Zhou X, Ozen AC, Chiew M, Sawiak S, Emir U, Chan DD. An Accelerated PETALUTE MRI Sequence for In Vivo Quantification of Sodium Content in Human Articular Cartilage at 3T. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2024:2024.05.02.24305807. [PMID: 38746343 PMCID: PMC11092686 DOI: 10.1101/2024.05.02.24305807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
In this work, we demonstrate the sodium magnetic resonance imaging (MRI) capabilities of a three-dimensional (3D) dual-echo ultrashort echo time (UTE) sequence with a novel rosette petal trajectory (PETALUTE), in comparison to the 3D density-adapted (DA) radial spokes UTE sequence. We scanned five healthy subjects using a 3D dual-echo PETALUTE acquisition and two comparable implementations of 3D DA-radial spokes acquisitions, one matching the number of k-space projections (Radial-Matched Trajectories) and the other matching the total number of samples (Radial-Matched Samples) acquired in k-space. The PETALUTE acquisition enabled equivalent sodium quantification in articular cartilage volumes of interest (168.8 ± 29.9 mM) to those derived from the 3D radial acquisitions (171.62 ± 28.7 mM and 149.8 ± 22.2 mM, respectively). We achieved a shorter scan time of 2:06 for 3D PETALUTE, compared to 3:36 for 3D radial acquisitions. We also evaluated the feasibility of further acceleration of the PETALUTE sequence through retrospective compressed sensing with 2× and 4× acceleration of the first echo and showed structural similarity of 0.89 ± 0.03 and 0.87 ± 0.03 when compared to non-retrospectively accelerated reconstruction. Together, these results demonstrate improved scan time with equivalent performance of the PETALUTE sequence compared to the 3D DA-radial sequence for sodium MRI of articular cartilage.
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Dergachyova O, Yu Z, Hodono S, Cloos M, Madelin G. Analysis of blurring due to short T 2 decay at different resolutions in 23Na MRI. ARXIV 2024:arXiv:2404.11774v1. [PMID: 38699168 PMCID: PMC11065050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 05/05/2024]
Abstract
The nuclear magnetic resonance signal from sodium (23Na) nuclei demonstrates a fast bi-exponential T2 decay in biological tissues (T2,short = 0.5-5 ms and T2,long = 10-30 ms). Hence, blurring observed in sodium images acquired with center-out sequences is generally assumed to be dominated by signal attenuation at higher k-space frequencies. Most of the studies in the field primarily focus on the impact of readout duration on blurring but neglect the impact of resolution. In this paper, we examine the blurring effect of short T2 on images at different resolutions. A series of simulations, as well as phantom and in vivo scans were performed at varying resolutions and readout durations in order to evaluate progressive changes in image quality. We demonstrate that, given a fixed readout duration, T2 decay produces distinct blurring effects at different resolutions. Therefore, in addition to voxel size-dependent partial volume effects, the choice of resolution adds additional T2-dependent blurring.
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Affiliation(s)
- Olga Dergachyova
- Center for Biomedical Imaging, Department of Radiology, New York University Grossman School of Medicine, New York, NY, USA
| | - Zidan Yu
- Center for Biomedical Imaging, Department of Radiology, New York University Grossman School of Medicine, New York, NY, USA
- Department of Medicine, John A. Burns School of Medicine, University of Hawaii, Honolulu, HI, USA
| | - Shota Hodono
- Center for Biomedical Imaging, Department of Radiology, New York University Grossman School of Medicine, New York, NY, USA
- Centre for Advanced Imaging, The University of Queensland, Brisbane, QLD, Australia
- Donders Centre for Cognitive Neuroimaging, Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, The Netherlands
| | - Martijn Cloos
- Center for Biomedical Imaging, Department of Radiology, New York University Grossman School of Medicine, New York, NY, USA
- Centre for Advanced Imaging, The University of Queensland, Brisbane, QLD, Australia
| | - Guillaume Madelin
- Center for Biomedical Imaging, Department of Radiology, New York University Grossman School of Medicine, New York, NY, USA
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Christa M, Dithmar F, Weinaus T, Kohlhaas M, Arias-Loza AP, Hofmann M, Elabyad IA, Gutjahr FT, Maack C, Bauer WR. A new approach to characterize cardiac sodium storage by combining fluorescence photometry and magnetic resonance imaging in small animal research. Sci Rep 2024; 14:2426. [PMID: 38287086 PMCID: PMC10825176 DOI: 10.1038/s41598-024-52377-w] [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: 07/17/2023] [Accepted: 01/18/2024] [Indexed: 01/31/2024] Open
Abstract
Cardiac myocyte sodium (Na+) homoeostasis is pivotal in cardiac diseases and heart failure. Intracellular Na+ ([Na+]i) is an important regulator of excitation-contraction coupling and mitochondrial energetics. In addition, extracellular Na+ ([Na+]e) and its water-free storage trigger collagen cross-linking, myocardial stiffening and impaired cardiac function. Therefore, understanding the allocation of tissue Na+ to intra- and extracellular compartments is crucial in comprehending the pathophysiological processes in cardiac diseases. We extrapolated [Na+]e using a three-compartment model, with tissue Na+ concentration (TSC) measured by in vivo 23Na-MRI, extracellular volume (ECV) data calculated from T1 maps, and [Na+]i measured by in vitro fluorescence microscopy using Na+ binding benzofuran isophthalate (SBFI). To investigate dynamic changes in Na+ compartments, we induced pressure overload (TAC) or myocardial infarction (MI) via LAD ligation in mice. Compared to SHAM mice, TSC was similar after TAC but increased after MI. Both TAC and MI showed significantly higher [Na+]i compared to SHAM (around 130% compared to SHAM). Calculated [Na+]e increased after MI, but not after TAC. Increased TSC after TAC was primarily driven by increased [Na+]i, but the increase after MI by elevations in both [Na+]i and [Na+]e.
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Affiliation(s)
- Martin Christa
- Comprehensive Heart Failure Center, University and University Hospital Würzburg, Würzburg, Germany.
- Department of Internal Medicine I, University Hospital Würzburg, Oberdürrbacher Straße 6, Haus A3, 97080, Würzburg, Germany.
| | - Franziska Dithmar
- Comprehensive Heart Failure Center, University and University Hospital Würzburg, Würzburg, Germany
- Department of Internal Medicine I, University Hospital Würzburg, Oberdürrbacher Straße 6, Haus A3, 97080, Würzburg, Germany
| | - Tobias Weinaus
- Comprehensive Heart Failure Center, University and University Hospital Würzburg, Würzburg, Germany
- Department of Internal Medicine I, University Hospital Würzburg, Oberdürrbacher Straße 6, Haus A3, 97080, Würzburg, Germany
| | - Michael Kohlhaas
- Comprehensive Heart Failure Center, University and University Hospital Würzburg, Würzburg, Germany
| | - Anahi-Paula Arias-Loza
- Comprehensive Heart Failure Center, University and University Hospital Würzburg, Würzburg, Germany
| | - Michelle Hofmann
- Comprehensive Heart Failure Center, University and University Hospital Würzburg, Würzburg, Germany
| | - Ibrahim A Elabyad
- Comprehensive Heart Failure Center, University and University Hospital Würzburg, Würzburg, Germany
| | | | - Christoph Maack
- Comprehensive Heart Failure Center, University and University Hospital Würzburg, Würzburg, Germany
| | - Wolfgang R Bauer
- Comprehensive Heart Failure Center, University and University Hospital Würzburg, Würzburg, Germany
- Department of Internal Medicine I, University Hospital Würzburg, Oberdürrbacher Straße 6, Haus A3, 97080, Würzburg, Germany
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Polak P, Schulte RF, Noseworthy MD. An approach to evaluation of the point-spread function for 23 Na magnetic resonance imaging. NMR IN BIOMEDICINE 2022; 35:e4627. [PMID: 34652040 DOI: 10.1002/nbm.4627] [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: 07/27/2021] [Revised: 08/28/2021] [Accepted: 09/11/2021] [Indexed: 06/13/2023]
Abstract
Despite the technical challenges that require lengthy acquisitions to overcome poor signal-to-noise ratio (SNR), sodium (23 Na) magnetic resonance imaging (MRI) is an intriguing area of research due to its essential role in human metabolism. Low SNR images can impact the measurement of the point-spread function (PSF) by adding uncertainty into the resulting quantities. Here, we present methods to calculate the PSF by using the modulation transfer function (MTF), and a 3D-printed line-pair phantom in the context of 23 Na MRI. A simulation study investigated the effect of noise on the resulting MTF curves, which were derived by direct modulation (DM) and a method utilizing Fourier harmonics (FHs). Experimental data utilized a line-pair phantom with nine spatial frequencies, filled with different concentrations (15, 30, and 60 mM) of sodium in 3% agar. MTF curves were calculated using both methods from data acquired from density-adapted 3D radial projections (DA-3DRP) and Fermat looped orthogonally encoded trajectories (FLORET). Simulations indicated that the DM method increased variability in the MTF curves at all tested noise levels over the FH method. For the experimental data, the FH method resulted in PSFs with a narrower full width half maximum with reduced variability, although the improvement in variability was not as pronounced as predicted by simulations. The DA-3DRP data indicated an improvement in the PSF over FLORET. It was concluded that a 3D-printed line-pair phantom represents a convenient method to measure the PSF experimentally. The MTFs from the noisy images in 23 Na MRI have reduced variability from a FH method over DM.
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Affiliation(s)
- Paul Polak
- School of Biomedical Engineering, McMaster University, Hamilton, Ontario, Canada
- Imaging Research Centre, St. Joseph's Healthcare, Hamilton, Ontario, Canada
| | | | - Michael D Noseworthy
- School of Biomedical Engineering, McMaster University, Hamilton, Ontario, Canada
- Imaging Research Centre, St. Joseph's Healthcare, Hamilton, Ontario, Canada
- Electrical and Computer Engineering, McMaster University, Hamilton, Ontario, Canada
- Department of Radiology, McMaster University, Hamilton, Ontario, Canada
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5
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Kamp B, Frenken M, Henke JM, Abrar DB, Nagel AM, Gast LV, Oeltzschner G, Wilms LM, Nebelung S, Antoch G, Wittsack HJ, Müller-Lutz A. Quantification of Sodium Relaxation Times and Concentrations as Surrogates of Proteoglycan Content of Patellar CARTILAGE at 3T MRI. Diagnostics (Basel) 2021; 11:diagnostics11122301. [PMID: 34943538 PMCID: PMC8700247 DOI: 10.3390/diagnostics11122301] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 12/03/2021] [Accepted: 12/06/2021] [Indexed: 11/25/2022] Open
Abstract
Sodium MRI has the potential to depict cartilage health accurately, but synovial fluid can influence the estimation of sodium parameters of cartilage. Therefore, this study aimed to reduce the impact of synovial fluid to render the quantitative compositional analyses of cartilage tissue technically more robust. Two dedicated protocols were applied for determining sodium T1 and T2* relaxation times. For each protocol, data were acquired from 10 healthy volunteers and one patient with patellar cartilage damage. Data recorded with multiple repetition times for T1 measurement and multi-echo data acquired with an additional inversion recovery pulse for T2* measurement were analysed using biexponential models to differentiate longitudinal relaxation components of cartilage (T1,car) and synovial fluid (T1,syn), and short (T2s*) from long (T2l*) transversal relaxation components. Sodium relaxation times and concentration estimates in patellar cartilage were successfully determined: T1,car = 14.5 ± 0.7 ms; T1,syn = 37.9 ± 2.9 ms; c(T1-protocol) = 200 ± 48 mmol/L; T2s* = 0.4 ± 0.1 ms; T2l* = 12.6 ± 0.7 ms; c(T2*-protocol) = 215 ± 44 mmol/L for healthy volunteers. In conclusion, a robust determination of sodium relaxation times is possible at a clinical field strength of 3T to quantify sodium concentrations, which might be a valuable tool to determine cartilage health.
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Affiliation(s)
- Benedikt Kamp
- Department of Diagnostic and Interventional Radiology, Medical Faculty, University Dusseldorf, D-40225 Dusseldorf, Germany; (B.K.); (J.M.H.); (D.B.A.); (L.M.W.); (S.N.); (G.A.); (H.-J.W.); (A.M.-L.)
| | - Miriam Frenken
- Department of Diagnostic and Interventional Radiology, Medical Faculty, University Dusseldorf, D-40225 Dusseldorf, Germany; (B.K.); (J.M.H.); (D.B.A.); (L.M.W.); (S.N.); (G.A.); (H.-J.W.); (A.M.-L.)
- Correspondence:
| | - Jan M. Henke
- Department of Diagnostic and Interventional Radiology, Medical Faculty, University Dusseldorf, D-40225 Dusseldorf, Germany; (B.K.); (J.M.H.); (D.B.A.); (L.M.W.); (S.N.); (G.A.); (H.-J.W.); (A.M.-L.)
- Clinic of Nuclear Medicine, Medical Faculty, University Dusseldorf, D-40225 Dusseldorf, Germany
| | - Daniel B. Abrar
- Department of Diagnostic and Interventional Radiology, Medical Faculty, University Dusseldorf, D-40225 Dusseldorf, Germany; (B.K.); (J.M.H.); (D.B.A.); (L.M.W.); (S.N.); (G.A.); (H.-J.W.); (A.M.-L.)
| | - Armin M. Nagel
- Institute of Radiology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), D-91054 Erlangen, Germany; (A.M.N.); (L.V.G.)
- German Cancer Research Center (DKFZ), Division of Medical Physics in Radiology, D-69120 Heidelberg, Germany
| | - Lena V. Gast
- Institute of Radiology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), D-91054 Erlangen, Germany; (A.M.N.); (L.V.G.)
| | - Georg Oeltzschner
- Russell H. Morgan Department for Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD 21205-2196, USA;
- F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD 21205-2196, USA
| | - Lena M. Wilms
- Department of Diagnostic and Interventional Radiology, Medical Faculty, University Dusseldorf, D-40225 Dusseldorf, Germany; (B.K.); (J.M.H.); (D.B.A.); (L.M.W.); (S.N.); (G.A.); (H.-J.W.); (A.M.-L.)
| | - Sven Nebelung
- Department of Diagnostic and Interventional Radiology, Medical Faculty, University Dusseldorf, D-40225 Dusseldorf, Germany; (B.K.); (J.M.H.); (D.B.A.); (L.M.W.); (S.N.); (G.A.); (H.-J.W.); (A.M.-L.)
| | - Gerald Antoch
- Department of Diagnostic and Interventional Radiology, Medical Faculty, University Dusseldorf, D-40225 Dusseldorf, Germany; (B.K.); (J.M.H.); (D.B.A.); (L.M.W.); (S.N.); (G.A.); (H.-J.W.); (A.M.-L.)
| | - Hans-Jörg Wittsack
- Department of Diagnostic and Interventional Radiology, Medical Faculty, University Dusseldorf, D-40225 Dusseldorf, Germany; (B.K.); (J.M.H.); (D.B.A.); (L.M.W.); (S.N.); (G.A.); (H.-J.W.); (A.M.-L.)
| | - Anja Müller-Lutz
- Department of Diagnostic and Interventional Radiology, Medical Faculty, University Dusseldorf, D-40225 Dusseldorf, Germany; (B.K.); (J.M.H.); (D.B.A.); (L.M.W.); (S.N.); (G.A.); (H.-J.W.); (A.M.-L.)
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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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7
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Can sodium MRI be used as a method for mapping of cartilage stiffness? MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2020; 34:327-336. [PMID: 33180225 PMCID: PMC8154796 DOI: 10.1007/s10334-020-00893-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 09/19/2020] [Accepted: 10/23/2020] [Indexed: 11/10/2022]
Abstract
Objective Sodium concentration is responsible for (at least part of) the stiffness of articular cartilage due to the osmotic pressure it generates. Therefore, we hypothesized that we could use sodium MRI to approximate the stiffness of cartilage to assess early cartilage degeneration. Methods Four human tibial plateaus were retrieved from patients undergoing total knee replacement (TKR), and their cartilage stiffness mapped with indentation testing, after which samples were scanned in a 7 T MRI to determine sodium concentration. The relation of biomechanical parameters to MRI sodium and glycosaminoglycan (GAG) concentration was explored by a linear mixed model. Results Weak correlations of GAG concentration with apparent peak modulus (p = 0.0057) and apparent equilibrium modulus (p = 0.0181) were observed and lack of correlation of GAG concentration versus MRI sodium concentration was observed. MRI sodium concentration was not correlated with apparent peak modulus, though a moderate correlation of MRI sodium concentration with permeability was shown (p = 0.0014). Discussion and conclusion Although there was correlation between GAG concentration and cartilage stiffness, this was not similar with sodium concentration as measured by MRI. Thus, if the correlation between MRI sodium imaging and GAG concentration could be resolved, this strategy for assessing cartilage functional quality still holds promise. Electronic supplementary material The online version of this article (10.1007/s10334-020-00893-x) contains supplementary material, which is available to authorized users.
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Papp D, Breda S, Oei E, Poot D, Kotek G, Hernandez-Tamames J. Fractional order vs. exponential fitting in UTE MR imaging of the patellar tendon. Magn Reson Imaging 2020; 70:91-97. [DOI: 10.1016/j.mri.2020.04.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 03/09/2020] [Accepted: 04/11/2020] [Indexed: 01/18/2023]
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9
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de Graaf RA, Hendriks AD, Klomp DWJ, Kumaragamage C, Welting D, de Castro CSA, Brown PB, McIntyre S, Nixon TW, Prompers JJ, De Feyter HM. On the magnetic field dependence of deuterium metabolic imaging. NMR IN BIOMEDICINE 2020; 33:e4235. [PMID: 31879985 PMCID: PMC7141779 DOI: 10.1002/nbm.4235] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 10/15/2019] [Accepted: 11/10/2019] [Indexed: 05/23/2023]
Abstract
Deuterium metabolic imaging (DMI) is a novel MR-based method to spatially map metabolism of deuterated substrates such as [6,6'-2 H2 ]-glucose in vivo. Compared with traditional 13 C-MR-based metabolic studies, the MR sensitivity of DMI is high due to the larger 2 H magnetic moment and favorable T1 and T2 relaxation times. Here, the magnetic field dependence of DMI sensitivity and transmit efficiency is studied on phantoms and rat brain postmortem at 4, 9.4 and 11.7 T. The sensitivity and spectral resolution on human brain in vivo are investigated at 4 and 7 T before and after an oral dose of [6,6'-2 H2 ]-glucose. For small animal surface coils (Ø 30 mm), the experimentally measured sensitivity and transmit efficiency scale with the magnetic field to a power of +1.75 and -0.30, respectively. These are in excellent agreement with theoretical predictions made from the principle of reciprocity for a coil noise-dominant regime. For larger human surface coils (Ø 80 mm), the sensitivity scales as a +1.65 power. The spectral resolution increases linearly due to near-constant linewidths. With optimal multireceiver arrays the acquisition of DMI at a nominal 1 mL spatial resolution is feasible at 7 T.
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Affiliation(s)
- Robin A. de Graaf
- Department of Radiology and Biomedical Imaging, Magnetic Resonance Research Center, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Arjan D. Hendriks
- Department of Radiology, Imaging Division, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Dennis W. J. Klomp
- Department of Radiology, Imaging Division, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Chathura Kumaragamage
- Department of Radiology and Biomedical Imaging, Magnetic Resonance Research Center, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Dimitri Welting
- Department of Radiology, Imaging Division, University Medical Center Utrecht, Utrecht, The Netherlands
| | | | - Peter B. Brown
- Department of Radiology and Biomedical Imaging, Magnetic Resonance Research Center, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Scott McIntyre
- Department of Radiology and Biomedical Imaging, Magnetic Resonance Research Center, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Terence W. Nixon
- Department of Radiology and Biomedical Imaging, Magnetic Resonance Research Center, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Jeanine J. Prompers
- Department of Radiology, Imaging Division, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Henk M. De Feyter
- Department of Radiology and Biomedical Imaging, Magnetic Resonance Research Center, Yale University School of Medicine, New Haven, Connecticut, USA
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Juras V, Mlynarik V, Szomolanyi P, Valkovič L, Trattnig S. Magnetic Resonance Imaging of the Musculoskeletal System at 7T: Morphological Imaging and Beyond. Top Magn Reson Imaging 2019; 28:125-135. [PMID: 30951006 PMCID: PMC6565434 DOI: 10.1097/rmr.0000000000000205] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In 2017, a whole-body 7T magnetic resonance imaging (MRI) device was given regulatory approval for clinical use in both the EU and United States for neuro and musculoskeletal applications. As 7 Tesla allows for higher signal-to-noise , which results in higher resolution images than those obtained on lower-field-strength scanners, it has attracted considerable attention from the musculoskeletal field, as evidenced by the increasing number of publications in the last decade. Besides morphological imaging, the quantitative MR methods, such as T2, T2∗, T1ρ mapping, sodium imaging, chemical-exchange saturation transfer, and spectroscopy, substantially benefit from ultrahigh field scanning. In this review, we provide technical considerations for the individual techniques and an overview of (mostly) clinical applications for the assessment of cartilage, tendon, meniscus, and muscle. The first part of the review is dedicated to morphological applications at 7T, and the second part describes the most recent developments in quantitative MRI at 7T.
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Affiliation(s)
- 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 Measurements Science, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Vladimir Mlynarik
- High-field MR Center, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria.,Karl Landsteiner Society, St. Pölten, Austria
| | - Pavol Szomolanyi
- High-field MR Center, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria.,Department of Imaging Methods, Institute of Measurements Science, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Ladislav Valkovič
- High-field MR Center, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria.,Oxford Centre for Clinical Magnetic Resonance Research, BHF Centre of Research Excellence, University of Oxford, Oxford, UK.,Department of Imaging Methods, Institute of Measurements Science, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Siegfried Trattnig
- High-field MR Center, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria.,Austrian Cluster for Tissue Regeneration, Vienna, Austria.,Christian Doppler Laboratory for Clinical Molecular MR Imaging, Vienna, Austria
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11
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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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Abstract
In this article, an overview of the current developments and research applications for non-proton magnetic resonance imaging (MRI) at ultrahigh magnetic fields (UHFs) is given. Due to technical and methodical advances, efficient MRI of physiologically relevant nuclei, such as Na, Cl, Cl, K, O, or P has become feasible and is of interest to obtain spatially and temporally resolved information that can be used for biomedical and diagnostic applications. Sodium (Na) MRI is the most widespread multinuclear imaging method with applications ranging over all regions of the human body. Na MRI yields the second largest in vivo NMR signal after the clinically used proton signal (H). However, other nuclei such as O and P (energy metabolism) or Cl and K (cell viability) are used in an increasing number of MRI studies at UHF. One major advancement has been the increased availability of whole-body MR scanners with UHFs (B0 ≥7T) expanding the range of detectable nuclei. Nevertheless, efforts in terms of pulse sequence and post-processing developments as well as hardware designs must be made to obtain valuable information in clinically feasible measurement times. This review summarizes the available methods in the field of non-proton UHF MRI, especially for Na MRI, as well as introduces potential applications in clinical research.
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Affiliation(s)
- Sebastian C Niesporek
- Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Armin M Nagel
- Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Institute of Radiology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
- Institute of Medical Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Tanja Platt
- Division of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
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13
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Alizai H, Chang G, Regatte RR. MR Imaging of the Musculoskeletal System Using Ultrahigh Field (7T) MR Imaging. PET Clin 2019; 13:551-565. [PMID: 30219187 DOI: 10.1016/j.cpet.2018.05.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
MR imaging is an indispensable instrument for the diagnosis of musculoskeletal diseases. In vivo MR imaging at 7T offers many advantages, including increased signal-to-noise ratio, higher spatial resolution, improved spectral resolution for spectroscopy, improved sensitivity for X-nucleus imaging, and decreased image acquisition times. There are also however technical challenges of imaging at a higher field strength compared with 1.5 and 3T MR imaging systems. We discuss the many potential opportunities as well as the challenges presented by 7T MR imaging systems and highlight recent developments in in vivo research imaging of musculoskeletal applications in general and cartilage, skeletal muscle, and bone in particular.
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Affiliation(s)
- Hamza Alizai
- Department of Radiology, New York University Langone Medical Center, 660 First Avenue, New York, NY 10016, USA.
| | - Gregory Chang
- Department of Radiology, New York University Langone Medical Center, 660 First Avenue, New York, NY 10016, USA
| | - Ravinder R Regatte
- Department of Radiology, New York University Langone Medical Center, 660 First Avenue, New York, NY 10016, USA
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14
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Menon RG, Chang G, Regatte RR. The Emerging Role of 7 Tesla MRI in Musculoskeletal Imaging. CURRENT RADIOLOGY REPORTS 2018. [DOI: 10.1007/s40134-018-0286-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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15
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Peterson P, Tiderius CJ, Olsson E, Lundin B, Olsson LE, Svensson J. Knee dGEMRIC at 7 T: comparison against 1.5 T and evaluation of T 1-mapping methods. BMC Musculoskelet Disord 2018; 19:149. [PMID: 29769051 PMCID: PMC5956845 DOI: 10.1186/s12891-018-2071-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Accepted: 04/30/2018] [Indexed: 12/28/2022] Open
Abstract
Background dGEMRIC (delayed Gadolinium Enhanced Magnetic Resonance Image of Cartilage) is a well-established technique for cartilage quality assessment in osteoarthritis at clinical field strengths. The method is robust, but requires injection of contrast agent and a cumbersome examination procedure. New non-contrast-agent-based techniques for cartilage quality assessment are currently being developed at 7 T. However, dGEMRIC remains an important reference technique during this development. The aim of this work was to compare T1 mapping for dGEMRIC at 7 T and 1.5 T, and to evaluate three T1-mapping methods at 7 T. Methods The knee of 10 healthy volunteers and 9 patients with early signs of cartilage degradation were examined at 1.5 T and 7 T after a single (one) contrast agent injection (Gd-(DTPA)2−). Inversion recovery (IR) sequences were acquired at both field strengths, and at 7 T variable flip angle (VFA) and Look-Locker (LL) sequences were additionally acquired. T1 maps were calculated and average T1 values were estimated within superficial and deep regions-of-interest (ROIs) in the lateral and medial condyles, respectively. Results T1 values were 1.8 (1.4–2.3) times longer at 7 T. A strong correlation was detected between 1.5 T and 7 T T1 values (r = 0.80). For IR, an additional inversion time was required to avoid underestimation (bias±limits of agreement − 127 ± 234 ms) due to the longer T1 values at 7 T. Out of the two 3D sequences tested, LL resulted in more accurate and precise T1 estimation compared to VFA (average bias±limits of agreement LL: 12 ± 202 ms compared to VFA: 25 ± 622 ms). For both, B1 correction improved agreement to IR. Conclusion With an adapted sampling scheme, dGEMRIC T1 mapping is feasible at 7 T and correlates well to 1.5 T. If 3D is to be used for T1 mapping of the knee at 7 T, LL is preferred and VFA is not recommended. For VFA and LL, B1 correction is necessary for accurate T1 estimation.
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Affiliation(s)
- Pernilla Peterson
- Medical Radiation Physics, Department of Translational Medicine, Lund University, Inga Marie Nilssons gata 49, SE-205 02, Malmö, Sweden. .,Department of Oncology and Radiation Physics, Skåne University Hospital, Inga Marie Nilssons gata 49, SE-205 02, Malmö, Sweden.
| | - Carl Johan Tiderius
- Orthopedics, Department of Clinical Sciences, Lund University, Skåne University Hospital, SE-221 85, Lund, Sweden
| | - Emma Olsson
- Medical Radiation Physics, Department of Translational Medicine, Lund University, Inga Marie Nilssons gata 49, SE-205 02, Malmö, Sweden
| | - Björn Lundin
- Department of Medical Imaging and Physiology, Skåne University Hospital, SE-221 85, Lund, Sweden
| | - Lars E Olsson
- Medical Radiation Physics, Department of Translational Medicine, Lund University, Inga Marie Nilssons gata 49, SE-205 02, Malmö, Sweden.,Department of Oncology and Radiation Physics, Skåne University Hospital, Inga Marie Nilssons gata 49, SE-205 02, Malmö, Sweden
| | - Jonas Svensson
- Medical Radiation Physics, Department of Translational Medicine, Lund University, Inga Marie Nilssons gata 49, SE-205 02, Malmö, Sweden.,Department of Medical Imaging and Physiology, Skåne University Hospital, SE-221 85, Lund, Sweden
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16
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Hesper T, Schleich C, Buchwald A, Hosalkar HS, Antoch G, Krauspe R, Zilkens C, Bittersohl B. T2* Mapping of the Hip in Asymptomatic Volunteers with Normal Cartilage Morphology: An Analysis of Regional and Age-Dependent Distribution. Cartilage 2018; 9:30-37. [PMID: 28466651 PMCID: PMC5724674 DOI: 10.1177/1947603516684591] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Objective To assess age-dependent and regional differences in T2* relaxation measurements in hip joint cartilage of asymptomatic volunteers at 3 T. Design Three age cohorts (cohort 1: age 20-30 years, 15 individuals; cohort 2: age 30-40 years, 17 individuals; cohort 3: age 40-50 years, 15 individuals) were enrolled. T2* values were obtained in the central and peripheral cartilage of the acetabulum and the femoral head in 7 regions (anterior to superior and posterior). Results T2* did not differ among age cohorts in acetabular cartilage (cohort 1: 24.65 ± 6.56 ms, cohort 2: 24.70 ± 4.83 ms, cohort 3: 25.81 ± 5.10 ms, P = 0.10) and femoral head cartilage (cohort 1: 27.08 ± 8.24 ms, cohort 2: 25.90 ± 7.82 ms, cohort 3: 26.50 ± 5.61 ms, P = 0.34). Analysis of the regional T2* distribution pattern indicates increased T2* values in the anterior, anterior-superior, superior-anterior, and the posterior-superior aspects of acetabular and femoral head cartilage. For acetabular cartilage, higher values were observed in the central region (25.90 ± 4.80 ms vs. 24.21 ± 4.05 ms, P < 0.0001) whereas femoral head cartilage did not reveal such differences (26.62 ± 5.74 ms vs. 26.37 ± 5.89 ms, P = 0.44). Conclusions The T2* analysis of presumably healthy hip joint cartilage does not seem to be stratified according to age in this population. Regional T2* variation throughout hip joint cartilage is apparent in this modality.
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Affiliation(s)
- Tobias Hesper
- Department of Orthopedics, Medical Faculty, University of Düsseldorf, Düsseldorf, Germany
| | - Christoph Schleich
- Department of Diagnostic and Interventional Radiology, Medical Faculty, University of Düsseldorf, Düsseldorf, Germany
| | - Alexander Buchwald
- Department of Orthopedics, Medical Faculty, University of Düsseldorf, Düsseldorf, Germany
| | - Harish S. Hosalkar
- Paradise Valley Hospital, National City, CA, USA,Tri-city Medical Center, San Diego, CA, USA
| | - Gerald Antoch
- Department of Diagnostic and Interventional Radiology, Medical Faculty, University of Düsseldorf, Düsseldorf, Germany
| | - Rüdiger Krauspe
- Department of Orthopedics, Medical Faculty, University of Düsseldorf, Düsseldorf, Germany
| | - Christoph Zilkens
- Department of Orthopedics, Medical Faculty, University of Düsseldorf, Düsseldorf, Germany
| | - Bernd Bittersohl
- Department of Orthopedics, Medical Faculty, University of Düsseldorf, Düsseldorf, Germany,Bernd Bittersohl, Department of Orthopedics, Heinrich-Heine University Düsseldorf, Moorenstr. 5, 40225 Düsseldorf, Germany.
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17
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Wang P, Deger MS, Kang H, Ikizler TA, Titze J, Gore JC. Sex differences in sodium deposition in human muscle and skin. Magn Reson Imaging 2017; 36:93-97. [PMID: 27989912 PMCID: PMC5222810 DOI: 10.1016/j.mri.2016.10.023] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Revised: 10/08/2016] [Accepted: 10/26/2016] [Indexed: 12/14/2022]
Abstract
The aim of this work was to investigate possible sex differences in the patterns of sodium deposition between muscle and skin using sodium MRI. A total of 38 subjects were examined for comparisons: 20 males, aged 25-79years with a median age of 51; 18 females, aged 38-66years, median age 53. All subjects underwent sodium MRI scans of the calf muscles together with cross sections through four calibration standards containing known sodium contents (10mM, 20mM, 30mM, and 40mM). Tissue sodium concentrations (TSC) in muscle and skin were then calculated by comparing signal intensities between tissues and reference standards using a linear analysis. A Wilcoxon rank sum test was applied to the ΔTSC (=TSCmuscle-TSCskin) series of males and females to examine if they were significantly different. Finally, a multiple linear regression was utilized to account for the effects from two potential confounders, age and body mass index (BMI). We found that sodium content appears to be higher in skin than in muscle for men, however women tend to have higher muscle sodium than skin sodium. This sex-relevant sodium deposition is statistically significant (P=3.10×10-5) by the Wilcoxon rank sum test, and this difference in distribution seems to be more reliable with increasing age. In the multiple linear regression, gender still has a statistically significant effect (P<1.0×10-4) on the difference between sodium deposition in muscle and skin, while taking the effects of age and BMI into account.
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Affiliation(s)
- Ping Wang
- Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA.
| | - Muge Serpil Deger
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Hakmook Kang
- Department of Biostatistics, Vanderbilt University Medical Center, Nashville, TN, USA
| | - T Alp Ikizler
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Jens Titze
- Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - John C Gore
- Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, USA; Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
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18
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Liu F, Kijowski R. Assessment of different fitting methods for in-vivo bi-component T2 * analysis of human patellar tendon in magnetic resonance imaging. Muscles Ligaments Tendons J 2017; 7:163-172. [PMID: 28717625 PMCID: PMC5505585 DOI: 10.11138/mltj/2017.7.1.163] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
PURPOSE To investigate the robustness of four fitting methods for bi-component effective spin-spin T2 (T2*) relaxation time analysis of human patellar tendon. METHODS A three-dimensional (3D) cone ultra-short echo-time (UTE) sequence was performed on the knees of ten healthy volunteers at 3.0T. Four fitting methods incorporating either Gaussian or Rician noise distribution were used for voxel-by-voxel bi-component T2* analysis of the patellar tendon. The T2* for the short relaxing (T**,s ) and long relaxing (T*2,l ) water components and the fraction of the short relaxing water component (fs ) were measured, and different fitting methods were compared using Friedman's and Wilcoxon signed rank tests. A numerical simulation study was also performed to predict the accuracy and precision of bi-component T2* parameter estimation in tendon at different signal-to-noise ratios (SNR) levels. RESULTS The average T*2,s , T*2,l , fs of human patellar tendon were 1.5ms, 30ms, and 80% respectively. Incorporating different noise models and fitting methods influenced the measured bi-component T2* parameters. Fitting methods incorporating Rician noise were superior to traditional fitting methods for bi-component T2* analysis especially at lower SNR. fs and T*2,s were less sensitive than T*2,1 to noise at even moderate and low SNR. The result of the in-vivo bi-component T2* analysis of tendon agreed well with numerical simulations. CONCLUSION Our study demonstrated the use of a 3D cone UTE sequence to perform in vivo voxel-by-voxel bi-component T2* analysis of human patellar tendon. Incorporating Rician noise was useful for improving bi-component T2* analysis especially at lower SNR. LEVEL OF EVIDENCE IV.
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Affiliation(s)
- Fang Liu
- University of Wisconsin-Madison, USA
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19
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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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20
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Castets CR, Lefrançois W, Wecker D, Ribot EJ, Trotier AJ, Thiaudière E, Franconi JM, Miraux S. Fast 3D ultrashort echo-time spiral projection imaging using golden-angle: A flexible protocol for in vivo mouse imaging at high magnetic field. Magn Reson Med 2016; 77:1831-1840. [PMID: 27170060 DOI: 10.1002/mrm.26263] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Revised: 04/11/2016] [Accepted: 04/13/2016] [Indexed: 12/21/2022]
Abstract
PURPOSE To develop a fast three-dimensional (3D) k-space encoding method based on spiral projection imaging (SPI) with an interleaved golden-angle approach and to validate this novel sequence on small animal models. METHODS A disk-like trajectory, in which each disk contained spirals, was developed. The 3D encoding was performed by tilting the disks with a golden angle. The sharpness was first calculated at different T2* values. Then, the sharpness was measured on phantom using variable undersampling ratios. Finally, the sampling method was validated by whole brain time-of-flight angiography and ultrasmall superparamagnetic iron oxide (USPIO) enhanced free-breathing liver angiography on mouse. RESULTS The in vitro results demonstrated the robustness of the method for short T2* and high undersampling ratios. In vivo experiments showed the ability to properly detect small vessels in the brain with an acquisition time shorter than 1 min. Free-breathing mice liver angiography showed the insensitivity of this protocol toward motions and flow artifacts, and enabled the visualization of liver motion during breathing. CONCLUSIONS The method implemented here allowed fast 3D k-space sampling with a high undersampling ratio. Combining the advantages of center-out spirals with the flexibility of the golden angle approach could have major implications for real-time imaging. Magn Reson Med 77:1831-1840, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Charles R Castets
- Centre de Résonance Magnétique des Systèmes Biologiques, UMR5536 CNRS, Bordeaux, France.,Centre de Résonance Magnétique des Systèmes Biologiques, UMR5536 Université de Bordeaux, Bordeaux, France
| | - William Lefrançois
- Centre de Résonance Magnétique des Systèmes Biologiques, UMR5536 CNRS, Bordeaux, France.,Centre de Résonance Magnétique des Systèmes Biologiques, UMR5536 Université de Bordeaux, Bordeaux, France
| | | | - Emeline J Ribot
- Centre de Résonance Magnétique des Systèmes Biologiques, UMR5536 CNRS, Bordeaux, France.,Centre de Résonance Magnétique des Systèmes Biologiques, UMR5536 Université de Bordeaux, Bordeaux, France
| | - Aurélien J Trotier
- Centre de Résonance Magnétique des Systèmes Biologiques, UMR5536 CNRS, Bordeaux, France.,Centre de Résonance Magnétique des Systèmes Biologiques, UMR5536 Université de Bordeaux, Bordeaux, France
| | - Eric Thiaudière
- Centre de Résonance Magnétique des Systèmes Biologiques, UMR5536 CNRS, Bordeaux, France.,Centre de Résonance Magnétique des Systèmes Biologiques, UMR5536 Université de Bordeaux, Bordeaux, France
| | - Jean-Michel Franconi
- Centre de Résonance Magnétique des Systèmes Biologiques, UMR5536 CNRS, Bordeaux, France.,Centre de Résonance Magnétique des Systèmes Biologiques, UMR5536 Université de Bordeaux, Bordeaux, France
| | - Sylvain Miraux
- Centre de Résonance Magnétique des Systèmes Biologiques, UMR5536 CNRS, Bordeaux, France.,Centre de Résonance Magnétique des Systèmes Biologiques, UMR5536 Université de Bordeaux, Bordeaux, France
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Optimized cartilage visualization using 7-T sodium ((23)Na) imaging after patella dislocation. Knee Surg Sports Traumatol Arthrosc 2016; 24:1601-9. [PMID: 25429766 DOI: 10.1007/s00167-014-3455-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Accepted: 11/18/2014] [Indexed: 10/24/2022]
Abstract
PURPOSE Retropatellar cartilage lesions often occur in the course of recurrent patella dislocation. Aim of this study was to develop a more detailed method for examining cartilage tissue, in order to reduce patient discomfort and time of care. METHODS For detailed diagnosing, a 7-T MRI of the knee joint and patella was performed in nine patients, with mean age of 26.4 years, after patella dislocation to measure the cartilage content in three different regions of interest of the patella. Axial sodium ((23)Na) images were derived from an optimized 3D GRE sequence on a 7-T MR scanner. Morphological cartilage grading was performed, and sodium signal-to-noise ratio (SNR) values were calculated. Mean global sodium values and SNR were compared between patients and volunteers. RESULTS Two out of nine patients showed a maximum cartilage defect of International Cartilage Repair Society (ICRS) grade 3, three of grade 2, three of grade 1, and one patient showed no cartilage defect. The mean SNR in sodium images for cartilage was 13.4 ± 2.5 in patients and 14.6 ± 3.7 in volunteers (n.s.). A significant negative correlation between age and global sodium SNR for cartilage was found in the medial facet (R = -0.512; R (2) = 0.26; p = 0.030). Mixed-model ANOVA yielded a marked decrease of the sodium SNR, with increasing grade of cartilage lesions (p < 0.001). CONCLUSIONS Utilization of the (23)Na MR imaging will make earlier detection of alterations to the patella cartilage after dislocation possible and will help prevent subsequent disease due to start adequate therapy earlier in the rehabilitation process. LEVEL OF EVIDENCE II.
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22
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Zbýň Š, Mlynárik V, Juras V, Szomolanyi P, Trattnig S. Evaluation of cartilage repair and osteoarthritis with sodium MRI. NMR IN BIOMEDICINE 2016; 29:206-15. [PMID: 25810325 DOI: 10.1002/nbm.3280] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Revised: 01/20/2015] [Accepted: 01/29/2015] [Indexed: 06/04/2023]
Abstract
The growing need for early diagnosis and higher specificity than that which can be achieved with morphological MRI is a driving force in the application of methods capable of probing the biochemical composition of cartilage tissue, such as sodium imaging. Unlike morphological imaging, sodium MRI is sensitive to even small changes in cartilage glycosaminoglycan content, which plays a key role in cartilage homeostasis. Recent advances in high- and ultrahigh-field MR systems, gradient technology, phase-array radiofrequency coils, parallel imaging approaches, MRI acquisition strategies and post-processing developments have resulted in many clinical in vivo sodium MRI studies of cartilage, even at 3 T. Sodium MRI has great promise as a non-invasive tool for cartilage evaluation. However, further hardware and software improvements are necessary to complete the translation of sodium MRI into a clinically feasible method for 3-T systems. This review is divided into three parts: (i) cartilage composition, pathology and treatment; (ii) sodium MRI; and (iii) clinical sodium MRI studies of cartilage with a focus on the evaluation of cartilage repair tissue and osteoarthritis.
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Affiliation(s)
- Štefan Zbýň
- High-Field MR Center, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna/Vienna General Hospital, Vienna, Austria
- CD Laboratory for Clinical Molecular MR Imaging, Vienna, Austria
| | - Vladimír Mlynárik
- High-Field MR Center, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna/Vienna General Hospital, Vienna, Austria
- CD Laboratory for Clinical Molecular MR Imaging, Vienna, Austria
| | - Vladimir Juras
- High-Field MR Center, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna/Vienna General Hospital, 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 General Hospital, Vienna, Austria
- Department of Imaging Methods, Institute of Measurement Science, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Siegfried Trattnig
- High-Field MR Center, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna/Vienna General Hospital, Vienna, Austria
- CD Laboratory for Clinical Molecular MR Imaging, Vienna, Austria
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23
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Improved differentiation between knees with cartilage lesions and controls using 7T relaxation time mapping. J Orthop Translat 2015; 3:197-204. [PMID: 30035058 PMCID: PMC5986989 DOI: 10.1016/j.jot.2015.05.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Revised: 05/14/2015] [Accepted: 05/28/2015] [Indexed: 11/25/2022] Open
Abstract
Background/Objective T1ρ and T2 relaxation mapping in knee cartilage have been used extensively at 3 Tesla (T) as markers for proteoglycan and collagen, respectively. The objective of this study was to evaluate the feasibility of T1ρ and T2 imaging of knee cartilage at 7T in comparison to 3T and to evaluate the ability of T1ρ and T2 to determine differences between normal and osteoarthritis (OA) patients. Materials and methods Twenty patients, seven healthy patients (Kellgren–Lawrence = 0), and 13 patients with signs of radiographic OA (Kellgren–Lawrence > 0) were scanned at 3T and 7T. The knee cartilage was segmented into six compartments and the T1ρ and T2 values were fit using a two-parameter model. Additionally, patients were stratified by the presence of cartilage lesions using the modified Whole Organ Magnetic Resonance Imaging Score classification of the knee. One-way analysis of variance was used to compare the healthy and OA groups at 3T and 7T. The specific absorption ratio was kept under Food and Drug Administration limits during all scans. Results T1ρ and T2 values at 3T and 7T were significantly higher in the lateral femoral condyle and patella in patients with OA. However, more regions were significant or approached significance at 7T compared with 3T, with the differences between healthy and OA patients also larger at 7T. The signal to noise ratio across all cartilage and meniscus compartments was 60% higher on average at 7T compared to 3T. Conclusion T1ρ imaging at 7T has been established as a viable imaging method for the differentiation of degenerated cartilage despite previous concerns over specific absorption rate and imaging time. The potential increased sensitivity of T1ρ and T2 imaging at 7T may be useful for future studies in the development of OA.
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Abstract
At ultra-high magnetic fields, such as 7T, MR imaging can noninvasively visualize the brain in unprecedented detail and through enhanced contrast mechanisms. The increased SNR and enhanced contrast available at 7T enable higher resolution anatomic and vascular imaging. Greater spectral separation improves detection and characterization of metabolites in spectroscopic imaging. Enhanced blood oxygen level-dependent contrast affords higher resolution functional MR imaging. Ultra-high-field MR imaging also facilitates imaging of nonproton nuclei such as sodium and phosphorus. These improved imaging methods may be applied to detect subtle anatomic, functional, and metabolic abnormalities associated with a wide range of neurologic disorders, including epilepsy, brain tumors, multiple sclerosis, Alzheimer disease, and psychiatric conditions. At 7T, however, physical and hardware limitations cause conventional MR imaging pulse sequences to generate artifacts, requiring specialized pulse sequences and new hardware solutions to maximize the high-field gain in signal and contrast. Practical considerations for ultra-high-field MR imaging include cost, siting, and patient experience.
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Affiliation(s)
- P Balchandani
- From the Translational and Molecular Imaging Institute (P.B.) Department of Radiology (P.B., T.P.N.), Icahn School of Medicine at Mount Sinai, New York, New York.
| | - T P Naidich
- Department of Radiology (P.B., T.P.N.), Icahn School of Medicine at Mount Sinai, New York, New York
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Konstandin S, Krämer P, Günther M, Schad LR. Sodium magnetic resonance imaging using ultra-short echo time sequences with anisotropic resolution and uniform k-space sampling. Magn Reson Imaging 2014; 33:319-27. [PMID: 25527394 DOI: 10.1016/j.mri.2014.12.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Revised: 12/01/2014] [Accepted: 12/01/2014] [Indexed: 01/12/2023]
Abstract
A method for uniform k-space sampling of 3D ultra-short echo time (UTE) techniques with anisotropic resolution in one direction is introduced to increase signal-to-noise ratio (SNR). State-of-the-art acquisition schemes for sodium MRI with radial (projection reconstruction) and twisting (twisted projection imaging (TPI)) trajectories are investigated regarding SNR efficiency, blurring behavior under T2(⁎) decay, and measurement time in case of anisotropic field-of-view and resolution. 3D radial and twisting trajectories are redistributed in k-space for UTE sodium MRI with homogeneous noise distribution and optimal SNR efficiency, if T2(⁎) decay can be neglected. Simulations based on Voronoi tessellations and phantom simulations/measurements were performed to calculate SNR efficiency. Point-spread functions were simulated to demonstrate the influence of T2(⁎) decay on SNR and resolution. Phantom simulations/measurements and in vivo measurements confirm the SNR gain obtained by simulations based on Voronoi cells. An increase in SNR of up to 21% at an anisotropy factor of 10 could be theoretically achieved by TPI with projection adaption compared to the same sequence but without redistribution of projections in k-space. Sodium MRI with anisotropic resolution and uniform k-space sampling is demonstrated by in vivo measurements of human intervertebral disks and heart at 3 T. The SNR gain can be invested in a measurement time reduction of up to 32%, which is important especially for sodium MRI.
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Affiliation(s)
- Simon Konstandin
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany; MR-Imaging and Spectroscopy, Faculty 01 (Physics/Electrical Engineering), University of Bremen, NW 1 Otto-Hahn-Allee 1, 28359 Bremen, Germany.
| | - Philipp Krämer
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany
| | - Matthias Günther
- MR-Imaging and Spectroscopy, Faculty 01 (Physics/Electrical Engineering), University of Bremen, NW 1 Otto-Hahn-Allee 1, 28359 Bremen, Germany; Fraunhofer MEVIS, Universitätsallee 29, 28359 Bremen, Germany
| | - Lothar R Schad
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer-Ufer 1-3, 68167 Mannheim, Germany
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Zöllner FG, Kalayciyan R, Chacón-Caldera J, Zimmer F, Schad LR. Pre-clinical functional Magnetic Resonance Imaging part I: The kidney. Z Med Phys 2014; 24:286-306. [DOI: 10.1016/j.zemedi.2014.05.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Revised: 05/19/2014] [Accepted: 05/19/2014] [Indexed: 01/10/2023]
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Kijowski R, Chaudhary R. Quantitative magnetic resonance imaging of the articular cartilage of the knee joint. Magn Reson Imaging Clin N Am 2014; 22:649-69. [PMID: 25442027 DOI: 10.1016/j.mric.2014.07.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Osteoarthritis is characterized by a decrease in the proteoglycan content and disruption of the highly organized collagen fiber network of articular cartilage. Various quantitative magnetic resonance imaging techniques have been developed for noninvasive assessment of the proteoglycan and collagen components of cartilage. These techniques have been extensively used in clinical practice to detect early cartilage degeneration and in osteoarthritis research studies to monitor disease-related and treatment-related changes in cartilage over time. This article reviews the role of quantitative magnetic resonance imaging in evaluating the composition and ultrastructure of the articular cartilage of the knee joint.
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Affiliation(s)
- Richard Kijowski
- Department of Radiology, University of Wisconsin School of Medicine and Public Health, 600 Highland Avenue, Madison, WI 53792-3252, USA.
| | - Rajeev Chaudhary
- Department of Radiology, University of Wisconsin School of Medicine and Public Health, 600 Highland Avenue, Madison, WI 53792-3252, USA
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Jordan CD, Monu UD, McWalter EJ, Watkins RD, Chen W, Bangerter NK, Hargreaves BA, Gold GE. Variability of CubeQuant T1ρ, quantitative DESS T2, and cones sodium MRI in knee cartilage. Osteoarthritis Cartilage 2014; 22:1559-67. [PMID: 25278065 PMCID: PMC4185151 DOI: 10.1016/j.joca.2014.06.001] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Revised: 05/20/2014] [Accepted: 06/03/2014] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To measure the variability of T1ρ relaxation times using CubeQuant, T2 relaxation times using quantitative double echo in steady state (DESS), and normalized sodium signals using 3D cones sodium magnetic resonance imaging (MRI) of knee cartilage in vivo at 3 T. DESIGN Eight healthy subjects were scanned at 3 T at baseline, 1 day, 5 months, and 1 year. Ten regions of interest (ROIs) of knee cartilage were segmented in the medial and lateral compartments of each subject's knee. T1ρ and T2 relaxation times and normalized sodium signals were measured and the root-mean-square coefficient of variation (CVRMS) was calculated. Intra-subject variability was measured over short, moderate and long-term, as well as intra-observer and inter-observer variability. RESULTS The average intra-subject CVRMS measurements over short, moderate, and long-term time periods were 4.6%, 6.1%, and 6.0% for the T1ρ measurements, 6.4%, 9.3%, and 10.7% for the T2 measurements and 11.3%, 11.6%, and 12.9% for the sodium measurements, respectively. The average CVRMS measurements for intra-observer and inter-observer segmentation were 3.8% and 5.7% for the T1ρ measurements, 4.7% and 6.7% for the T2 measurements, and 8.1% and 11.4% for the sodium measurements, respectively. CONCLUSIONS These CVRMS measurements are substantially lower than previously measured changes expected in patients with advanced osteoarthritis compared to healthy volunteers, suggesting that CubeQuant T1ρ, quantitative DESS T2 and 3D cones sodium measurements are sufficiently sensitive for in vivo cartilage studies.
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Affiliation(s)
- Caroline D. Jordan
- Radiology, Stanford University, Stanford, CA, United States,Bioengineering, Stanford University, Stanford CA, United States
| | - Uchechukwuka D. Monu
- Radiology, Stanford University, Stanford, CA, United States,Electrical Engineering, Stanford University, Stanford CA, United States
| | | | | | - Weitian Chen
- GE Applied Science Laboratory, Menlo Park, CA, United States
| | - Neal K. Bangerter
- Electrical & Computer Engineering, Brigham Young University, Provo, UT, United States
| | - Brian A. Hargreaves
- Radiology, Stanford University, Stanford, CA, United States,Bioengineering, Stanford University, Stanford CA, United States,Electrical Engineering, Stanford University, Stanford CA, United States
| | - Garry E. Gold
- Radiology, Stanford University, Stanford, CA, United States,Bioengineering, Stanford University, Stanford CA, United States,Orthopaedic Surgery, Stanford University, Stanford, CA, United States
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Oei EHG, van Tiel J, Robinson WH, Gold GE. Quantitative radiologic imaging techniques for articular cartilage composition: toward early diagnosis and development of disease-modifying therapeutics for osteoarthritis. Arthritis Care Res (Hoboken) 2014; 66:1129-41. [PMID: 24578345 DOI: 10.1002/acr.22316] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2013] [Accepted: 02/18/2014] [Indexed: 12/19/2022]
Affiliation(s)
- Edwin H G Oei
- Stanford University, Stanford, California; Erasmus MC, University Medical Center, Rotterdam, The Netherlands
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Riley GM, McWalter EJ, Stevens KJ, Safran MR, Lattanzi R, Gold GE. MRI of the hip for the evaluation of femoroacetabular impingement; past, present, and future. J Magn Reson Imaging 2014; 41:558-72. [PMID: 25155435 DOI: 10.1002/jmri.24725] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Accepted: 07/21/2014] [Indexed: 11/07/2022] Open
Abstract
The concept of femoroacetabular impingement (FAI) has, in a relatively short time, come to the forefront of orthopedic imaging. In just a few short years MRI findings that were in the past ascribed to degenerative change, normal variation, or other pathologies must now be described and included in radiology reports, as they have been shown, or are suspected to be related to, FAI. Crucial questions have come up in this time, including: what is the relationship of bony morphology to subsequent cartilage and labral damage, and most importantly, how is this morphology related to the development of osteoarthritis? In this review, we attempt to place a historical perspective on the controversy, provide guidelines for interpretation of MRI examinations of patients with suspected FAI, and offer a glimpse into the future of MRI of this complex condition.
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Affiliation(s)
- Geoffrey M Riley
- Department of Radiology, Stanford University, Stanford, California, USA
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31
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Zuo H, Yao W, Qu N, Yang S, Wang J, Cui X. Quantitative evaluation in combination with nonquantitative evaluation in early patellar cartilage osteoarthritis at 3.0 T. Clin Interv Aging 2014; 9:1133-43. [PMID: 25075182 PMCID: PMC4106963 DOI: 10.2147/cia.s65871] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Purpose To evaluate quantitative T1 and T2 relaxation times and magnetization transfer ratios (MTRs) in the early diagnosis of patellar cartilage osteoarthritis (OA) and to quantify and possibly refine the current Kellgren-Lawrence score criteria. Materials and methods A total of 92 cases of knee joints with 40 normal volunteers and 30 patients with OA were prospectively evaluated. The knee joints with OA were divided into mild and moderate groups according to the Kellgren-Lawrence score criteria. The discriminative analysis method was used to analyze the accuracy of the original grouped cases correctly classified by age, sex, T1 relaxation times, T2 relaxation times, and MTR values. Linear regression analysis was used between T1 relaxation time, T2 relaxation time, and MTR values. Results The mean T1 relaxation times decreased with the severity of OA, and a significant difference was only found between the normal and moderate OA groups (P<0.05). The mean T2 relaxation times increased, and significant differences were found between the normal and mild OA groups and the normal and moderate OA groups (P<0.001). The MTR values were 35.8%±4.2%, 36.1%±3.2%, and 35.4%±3.8%, respectively. There were no significant differences between the normal and OA groups. In addition, T1 relaxation times were positively correlated with MTR values (P<0.01). A discriminative analysis using a synthesis of all the influential factors indicated a high accuracy rate (93.9%) for the correct classification of the original grouped cases. Conclusion Quantitative T1 and T2 relaxation times were useful in the diagnosis of early OA; T2 relaxation times were more relatively sensitive. The functional usefulness of MTR values may be limited. T1 relaxation times positively correlated with MTR values. Multiple quantitative parameters, combined with some relative nonquantitative clinical parameters and Kellgren-Lawrence scores, may be useful in the early stage of OA and provide better information for clinical treatment and follow-up.
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Affiliation(s)
- Houdong Zuo
- Department of Radiology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, People's Republic of China
| | - Weiwu Yao
- Department of Radiology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, People's Republic of China
| | - Nan Qu
- Department of Radiology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, People's Republic of China
| | - Shixun Yang
- Department of Radiology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, People's Republic of China
| | - Jianhua Wang
- Department of Orthopedics, Xin Hua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China
| | - Xiaojiang Cui
- Department of Surgery, Department of Obstetrics and Gynecology, Samuel Oschin Comprehensive Cancer Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
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Romanzetti S, Mirkes CC, Fiege DP, Celik A, Felder J, Shah NJ. Mapping tissue sodium concentration in the human brain: a comparison of MR sequences at 9.4Tesla. Neuroimage 2014; 96:44-53. [PMID: 24721332 DOI: 10.1016/j.neuroimage.2014.03.079] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Revised: 03/26/2014] [Accepted: 03/30/2014] [Indexed: 01/28/2023] Open
Abstract
Sodium is the second most abundant MR-active nucleus in the human body and is of fundamental importance for the function of cells. Previous studies have shown that many pathophysiological conditions induce an increase of the average tissue sodium concentration. To date, several MR sequences have been used to measure sodium. The aim of this study was to evaluate the performance and suitability of five different MR sequences for quantitative sodium imaging on a whole-body 9.4Tesla MR scanner. Numerical simulations, phantom experiments and in vivo imaging on healthy subjects were carried out. The results demonstrate that, of these five sequences, the Twisted Projection Imaging sequence is optimal for quantitative sodium imaging, as it combines a number of features which are particularly relevant in order to obtain high quality quantitative images of sodium. These include: ultra-short echo times, efficient k-space sampling, and robustness against off-resonance effects. Mapping of sodium in the human brain is a technique not yet fully explored in neuroscience. Ultra-high field sodium MRI may provide new insights into the pathogenesis of neurological disorders, and may help to develop new and disease-specific biomarkers for the early diagnosis and therapeutic intervention before irreversible brain damage has taken place.
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Affiliation(s)
- Sandro Romanzetti
- Institute of Neuroscience and Medicine (INM-4), Forschungszentrum Jülich, Jülich, Germany.
| | - Christian C Mirkes
- Institute of Neuroscience and Medicine (INM-4), Forschungszentrum Jülich, Jülich, Germany; Department for Biomedical Magnetic Resonance, University of Tübingen, Tuebingen, Germany; High-Field MR Center, Max Planck Institute for Biological Cybernetics, Tübingen, Germany
| | - Daniel P Fiege
- Institute of Neuroscience and Medicine (INM-4), Forschungszentrum Jülich, Jülich, Germany
| | - Avdo Celik
- Institute of Neuroscience and Medicine (INM-4), Forschungszentrum Jülich, Jülich, Germany
| | - Jörg Felder
- Institute of Neuroscience and Medicine (INM-4), Forschungszentrum Jülich, Jülich, Germany
| | - N Jon Shah
- Institute of Neuroscience and Medicine (INM-4), Forschungszentrum Jülich, Jülich, Germany; Institute of Neurology, RWTH Aachen University, Aachen, Germany; JARA-BRAIN Translational Medicine, Germany
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Moon CH, Furlan A, Kim JH, Zhao T, Shapiro R, Bae KT. Quantitative sodium MR imaging of native versus transplanted kidneys using a dual-tuned proton/sodium (1H/ 23Na) coil: initial experience. Eur Radiol 2014; 24:1320-6. [PMID: 24668008 DOI: 10.1007/s00330-014-3138-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Revised: 01/26/2014] [Accepted: 02/18/2014] [Indexed: 11/30/2022]
Abstract
OBJECTIVES To compare sodium ((23)Na) characteristics between native and transplanted kidneys using dual-tuned proton ((1)H)/sodium MRI. METHODS Six healthy volunteers and six renal transplant patients (3 normal function, 3 acute allograft rejection) were included. Proton/sodium MRI was obtained at 3 T using a dual-tuned coil. Signal to noise ratio (SNR), sodium concentration ([(23)Na]) and cortico-medullary sodium gradient (CMSG) were measured. Reproducibility of [(23)Na] measurement was also tested. SNR, [(23)Na] and CMSG of the native and transplanted kidneys were compared. RESULTS Proton and sodium images of kidneys were successfully acquired. SNR and [(23)Na] measurements of the native kidneys were reproducible at two different sessions. [(23)Na] and CMSG of the transplanted kidneys was significantly lower than those of the native kidneys: 153.5 ± 11.9 vs. 192.9 ± 9.6 mM (P = 0.002) and 8.9 ± 1.5 vs. 10.5 ± 0.9 mM/mm (P = 0.041), respectively. [(23)Na] and CMSG of the transplanted kidneys with normal function vs. acute rejection were not statistically different. CONCLUSIONS Sodium quantification of kidneys was reliably performed using proton/sodium MRI. [(23)Na] and CMSG of the transplanted kidneys were lower than those of the native kidneys, but without a statistically significant difference between patients with or without renal allograft rejection. KEY POINTS Dual-tuned proton/sodium RF coil enables co-registered proton and sodium MRI. Structural and sodium biochemical property can be acquired by dual-tuned proton/sodium MRI. Sodium and sodium gradient of kidneys can be measured by dual-tuned MRI. Sodium concentration was lower in transplanted kidneys than in native kidneys. Sodium gradient of transplanted kidneys was lower than for native kidneys.
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Affiliation(s)
- Chan Hong Moon
- Department of Radiology, University of Pittsburgh, 200 Lothrop Street, Presby South tower Suite 3950, Pittsburgh, PA, 15213, USA
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Zbýň Š, Mlynárik V, Juras V, Szomolanyi P, Trattnig S. Sodium MR Imaging of Articular Cartilage Pathologies. CURRENT RADIOLOGY REPORTS 2014; 2:41. [PMID: 24683524 PMCID: PMC3963441 DOI: 10.1007/s40134-014-0041-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Many studies have proved that noninvasive sodium MR imaging can directly determine the cartilage GAG content, which plays a central role in cartilage homeostasis. New technical developments in the recent decade have helped to transfer this method from in vitro to pre-clinical in vivo studies. Sodium imaging has already been applied for the evaluation of cartilage and repair tissue in patients after various cartilage repair surgery techniques and in patients with osteoarthritis. These studies showed that this technique could be helpful not only for assessment of the cartilage status, but also predictive for osteoarthritis. However, due to the low detectable sodium MR signal in cartilage, sodium imaging is still challenging, and further hardware and software improvements are necessary for translating sodium MR imaging into clinical practice, preferably to 3T MR systems.
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Affiliation(s)
- Štefan Zbýň
- High Field MR Center, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria
| | - Vladimír Mlynárik
- High Field MR Center, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria
| | - Vladimir Juras
- High Field MR Center, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria
| | - Pavol Szomolanyi
- High Field MR Center, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria
| | - Siegfried Trattnig
- High Field MR Center, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria
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36
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Haneder S, Juras V, Michaely HJ, Deligianni X, Bieri O, Schoenberg SO, Trattnig S, Zbýň Š. In vivo sodium (23Na) imaging of the human kidneys at 7 T: Preliminary results. Eur Radiol 2013; 24:494-501. [DOI: 10.1007/s00330-013-3032-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Revised: 09/02/2013] [Accepted: 09/12/2013] [Indexed: 10/26/2022]
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Li X, Majumdar S. Quantitative MRI of articular cartilage and its clinical applications. J Magn Reson Imaging 2013; 38:991-1008. [PMID: 24115571 DOI: 10.1002/jmri.24313] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2012] [Accepted: 06/21/2013] [Indexed: 12/27/2022] Open
Abstract
Cartilage is one of the most essential tissues for healthy joint function and is compromised in degenerative and traumatic joint diseases. There have been tremendous advances during the past decade using quantitative MRI techniques as a noninvasive tool for evaluating cartilage, with a focus on assessing cartilage degeneration during osteoarthritis (OA). In this review, after a brief overview of cartilage composition and degeneration, we discuss techniques that grade and quantify morphologic changes as well as the techniques that quantify changes in the extracellular matrix. The basic principles, in vivo applications, advantages, and challenges for each technique are discussed. Recent studies using the OA Initiative (OAI) data are also summarized. Quantitative MRI provides noninvasive measures of cartilage degeneration at the earliest stages of joint degeneration, which is essential for efforts toward prevention and early intervention in OA.
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Affiliation(s)
- Xiaojuan Li
- Musculoskeletal Quantitative Imaging Research Group, Department of Radiology and Biomedical Imaging, University of California, San Francisco, California, USA
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Moon CH, Kim JH, Zhao T, Bae KT. Quantitative23Na MRI of human knee cartilage using dual-tuned1H/23Na transceiver array radiofrequency coil at 7 tesla. J Magn Reson Imaging 2013; 38:1063-72. [DOI: 10.1002/jmri.24030] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2012] [Accepted: 12/12/2012] [Indexed: 12/20/2022] Open
Affiliation(s)
- Chan Hong Moon
- Department of Radiology; University of Pittsburgh; Pittsburgh, Pennsylvania USA
| | - Jung-Hwan Kim
- Department of Radiology; University of Pittsburgh; Pittsburgh, Pennsylvania USA
| | - Tiejun Zhao
- MR Research Support; Siemens Healthcare; Pittsburgh, Pennsylvania USA
| | - Kyongtae Ty Bae
- Department of Radiology; University of Pittsburgh; Pittsburgh, Pennsylvania USA
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Kaggie JD, Hadley JR, Badal J, Campbell JR, Park DJ, Parker DL, Morrell G, Newbould RD, Wood AF, Bangerter NK. A 3 T sodium and proton composite array breast coil. Magn Reson Med 2013; 71:2231-42. [PMID: 24105740 DOI: 10.1002/mrm.24860] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Revised: 06/04/2013] [Accepted: 06/06/2013] [Indexed: 11/07/2022]
Abstract
PURPOSE The objective of this study was to determine whether a sodium phased array would improve sodium breast MRI at 3 T. The secondary objective was to create acceptable proton images with the sodium phased array in place. METHODS A novel composite array for combined proton/sodium 3 T breast MRI is compared with a coil with a single proton and sodium channel. The composite array consists of a 7-channel sodium receive array, a larger sodium transmit coil, and a 4-channel proton transceive array. The new composite array design utilizes smaller sodium receive loops than typically used in sodium imaging, uses novel decoupling methods between the receive loops and transmit loops, and uses a novel multichannel proton transceive coil. The proton transceive coil reduces coupling between proton and sodium elements by intersecting the constituent loops to reduce their mutual inductance. The coil used for comparison consists of a concentric sodium and proton loop with passive decoupling traps. RESULTS The composite array coil demonstrates a 2-5× improvement in signal-to-noise ratio for sodium imaging and similar signal-to-noise ratio for proton imaging when compared with a simple single-loop dual resonant design. CONCLUSION The improved signal-to-noise ratio of the composite array gives breast sodium images of unprecedented quality in reasonable scan times.
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Affiliation(s)
- Joshua D Kaggie
- Department of Radiology, Utah Center for Advanced Imaging Research, University of Utah, Salt Lake City, Utah, USA; Department of Physics, University of Utah, Salt Lake City, Utah, USA
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Physiological assessment of in vivo human knee articular cartilage using sodium MR imaging at 1.5T. Magn Reson Imaging 2013; 31:1059-67. [DOI: 10.1016/j.mri.2013.01.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2012] [Revised: 11/04/2012] [Accepted: 01/13/2013] [Indexed: 12/30/2022]
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Feldman RE, Stobbe R, Watts A, Beaulieu C. Sodium imaging of the human knee using soft inversion recovery fluid attenuation. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2013; 234:197-206. [PMID: 23896067 DOI: 10.1016/j.jmr.2013.06.021] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2013] [Revised: 06/27/2013] [Accepted: 06/30/2013] [Indexed: 06/02/2023]
Abstract
Sodium signal strength in MRI is low when compared with (1)H. Thus, image voxel volumes must be relatively large in order to produce a sufficient signal-to-noise ratio (SNR). The measurement of sodium in cartilage is hindered by conflation with signal from the adjacent fluid spaces. Inversion recovery can be used to null signal from fluid, but reduces SNR. The purpose of this work was to optimize inversion recovery sodium MRI to enhance cartilage SNR while nulling fluid. Sodium relaxation was first measured for knee cartilage (T1=21±1 ms, T(2 fast)(∗)=0.8±0.2 ms, T(2 slow)(∗)=19.7±0.5 ms) and fluid (T1=48±3 ms, T2(∗)=47±4 ms) in nine healthy subjects at 4.7 T. The rapid relaxation of cartilage in relation to fluid permits the use of a lengthened inversion pulse to preferentially invert the fluid components. Simulations of inversion pulse length were performed to yield a cartilage SNR enhancing combination of parameters that nulled fluid. The simulations were validated in a phantom and then in vivo. B0 inhomogeneity was measured and the effect of off-resonance during the soft inversion pulse was assessed with simulation. Soft inversion recovery yielded twice the SNR and much improved sodium images of cartilage in human knee with little confounding signal from fluid.
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Newbould RD, Miller SR, Upadhyay N, Rao AW, Swann P, Gold GE, Strachan RK, Matthews PM, Taylor PC, Brown AP. T1-weighted sodium MRI of the articulator cartilage in osteoarthritis: a cross sectional and longitudinal study. PLoS One 2013; 8:e73067. [PMID: 23940822 PMCID: PMC3733834 DOI: 10.1371/journal.pone.0073067] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2013] [Accepted: 07/16/2013] [Indexed: 11/23/2022] Open
Abstract
Structural magnetic resonance imaging (MRI) has shown great utility in diagnosing soft tissue burden in osteoarthritis (OA), though MRI measures of cartilage integrity have proven more elusive. Sodium MRI can reflect the proteoglycan content of cartilage; however, it requires specialized hardware, acquisition sequences, and long imaging times. This study was designed to assess the potential of a clinically feasible sodium MRI acquisition to detect differences in the knee cartilage of subjects with OA versus healthy controls (HC), and to determine whether longitudinal changes in sodium content are observed at 3 and 6 months. 28 subjects with primary knee OA and 19 HC subjects age and gender matched were enrolled in this ethically-approved study. At baseline, 3 and 6 months subjects underwent structural MRI and a 0.4ms echo time 3D T1-weighted sodium scan as well as the knee injury and osteoarthritis outcome score (KOOS) and knee pain by visual analogue score (VAS). A standing radiograph of the knee was taken for Kellgren-Lawrence (K-L) scoring. A blinded reader outlined the cartilage on the structural images which was used to determine median T1-weighted sodium concentrations in each region of interest on the co-registered sodium scans. VAS, K-L, and KOOS all significantly separated the OA and HC groups. OA subjects had higher T1-weighted sodium concentrations, most strongly observed in the lateral tibial, lateral femoral and medial patella ROIs. There were no significant changes in cartilage volume or sodium concentration over 6 months. This study has shown that a clinically-feasible sodium MRI at a moderate 3T field strength and imaging time with fluid attenuation by T1 weighting significantly separated HCs from OA subjects.
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Affiliation(s)
- Rexford D Newbould
- Imanova Centre for Imaging Sciences, Hammersmith Hospital, Imperial College London, London, United Kingdom.
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Konstandin S, Nagel AM. Measurement techniques for magnetic resonance imaging of fast relaxing nuclei. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2013; 27:5-19. [PMID: 23881004 DOI: 10.1007/s10334-013-0394-3] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Revised: 07/09/2013] [Accepted: 07/10/2013] [Indexed: 12/24/2022]
Abstract
In this review article, techniques for sodium ((23)Na) magnetic resonance imaging (MRI) are presented. These techniques can also be used to image other nuclei with short relaxation times (e.g., (39)K, (35)Cl, (17)O). Twisted projection imaging, density-adapted 3D projection reconstruction, and 3D cones are preferred because of uniform k-space sampling and ultra-short echo times. Sampling density weighted apodization can be applied if intrinsic filtering is desired. This approach leads to an increased signal-to-noise ratio compared to postfiltered acquisition in cases of short readout durations relative to T 2 (*) relaxation time. Different MR approaches for anisotropic resolution are presented, which are important for imaging of thin structures such as myocardium, cartilage, and skin. The third part of this review article describes different methods to put more weighting either on the intracellular or the extracellular sodium signal by means of contrast agents, relaxation-weighted imaging, or multiple-quantum filtering.
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Affiliation(s)
- Simon Konstandin
- Computer Assisted Clinical Medicine, Heidelberg University, Mannheim, Germany
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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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Konstandin S, Schad LR. Two-dimensional radial sodium heart MRI using variable-rate selective excitation and retrospective electrocardiogram gating with golden angle increments. Magn Reson Med 2012; 70:791-9. [PMID: 23081799 DOI: 10.1002/mrm.24523] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Revised: 09/04/2012] [Accepted: 09/18/2012] [Indexed: 12/31/2022]
Abstract
PURPOSE Two-dimensional projection reconstruction methods provide advantages over three-dimensional techniques because of higher flexibility regarding the resolution and shorter scan time needed. To optimize a two-dimensional radial sequence with respect to signal-to-noise ratio, variable-rate selective excitation and retrospective electrocardiogram gating is investigated. METHODS The minimal radiofrequency pulse duration is simulated in dependence of the flip angle and coil parameters using sinc waveforms with two different variable-rate selective excitation approaches and a Fermi pulse. Retrospectively electrocardiogram-gated imaging with Golden Angle incremented projections was implemented to allow for continuous data acquisition enabling the possibility of dynamic electrocardiogram-gated heart imaging. RESULTS Especially for abdominal coils with high transmitter voltages required, variable-rate selective excitation strongly reduces the radiofrequency pulse duration and echo time resulting in a signal-to-noise ratio gain up to 15.5% (if the fast relaxation component of sodium is in the order of the radiofrequency pulse duration) compared with standard sinc-shaped radiofrequency pulses. Retrospective electrocardiogram gating shows higher flexibility with regard to the trigger delay enabling the trade-off between heart motion artifacts and signal-to-noise ratio. CONCLUSION A two-dimensional radial sequence is optimized for sodium heart imaging regarding signal-to-noise ratio. Different sodium contrasts of the human heart are shown, which can give additional information on heart diseases.
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Affiliation(s)
- Simon Konstandin
- Computer Assisted Clinical Medicine, Heidelberg University, Mannheim, Germany
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Brown R, Madelin G, Lattanzi R, Chang G, Regatte RR, Sodickson DK, Wiggins GC. Design of a nested eight-channel sodium and four-channel proton coil for 7T knee imaging. Magn Reson Med 2012; 70:259-68. [PMID: 22887123 DOI: 10.1002/mrm.24432] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2011] [Revised: 03/14/2012] [Accepted: 06/30/2012] [Indexed: 12/30/2022]
Abstract
The critical design aim for a sodium/proton coil is to maximize sodium sensitivity and transmit field homogeneity while simultaneously providing adequate proton sensitivity and homogeneity. While most dual-frequency coils use lossy high-impedance trap circuits or PIN diodes to allow dual-resonance, we explored a nested-coil design for sodium/proton knee imaging at 7 T. A stand-alone eight-channel sodium receive array was implemented without standard dual-resonance circuitry to provide improved sodium signal-to-noise ratio. A detunable sodium birdcage was added for homogeneous sodium excitation and a four-channel proton transmit-receive array was added to provide anatomical reference imaging and B0 shimming capabilities. Both additional modules were implemented with minimal disturbance to the eight-channel sodium array by managing their respective resonances and geometrical arrangement. In vivo sodium signal-to-noise ratio was 1.2-1.7 times greater in the developed eight-channel array than in a mononuclear sodium birdcage coil, whereas the developed four-channel proton array provided signal-to-noise ratio similar to that of a commercial mononuclear proton birdcage coil.
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Affiliation(s)
- Ryan Brown
- Department of Radiology, New York University Langone Medical Center, New York, New York 10016, USA.
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Zbýň S, Stelzeneder D, Welsch GH, Negrin LL, Juras V, Mayerhoefer ME, Szomolanyi P, Bogner W, Domayer SE, Weber M, Trattnig S. Evaluation of native hyaline cartilage and repair tissue after two cartilage repair surgery techniques with 23Na MR imaging at 7 T: initial experience. Osteoarthritis Cartilage 2012; 20:837-45. [PMID: 22548796 DOI: 10.1016/j.joca.2012.04.020] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2011] [Revised: 04/15/2012] [Accepted: 04/24/2012] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To compare the sodium normalized mean signal intensity (NMSI) values between patients after bone marrow stimulation (BMS) and matrix-associated autologous chondrocyte transplantation (MACT) cartilage repair procedures. METHODS Nine BMS and nine MACT patients were included. Each BMS patient was matched with one MACT patient according to age [BMS 36.7 ± 10.7 (mean ± standard deviation) years; MACT 36.9 ± 10.0 years], postoperative interval (BMS 33.5 ± 25.3 months; MACT 33.2 ± 25.7 months), and defect location. All magnetic resonance imaging (MRI) measurements were performed on a 7 T system. Proton images served for morphological evaluation of repair tissue using the magnetic resonance observation of cartilage repair tissue (MOCART) scoring system. Sodium NMSI values in the repair area and morphologically normal cartilage were calculated. Clinical outcome was assessed right after MRI. Analysis of covariance, t-tests, and Pearson correlation coefficients were evaluated. RESULTS Sodium NMSI was significantly lower in BMS (P = 0.004) and MACT (P = 0.006) repair tissue, compared to reference cartilage. Sodium NMSI was not different between the reference cartilage in MACT and BMS patients (P = 0.664), however it was significantly higher in MACT than in BMS repair tissue (P = 0.028). Better clinical outcome was observed in BMS than in MACT patients. There was no difference between MOCART scores for MACT and BMS patients (P = 0.915). We did not observe any significant correlation between MOCART score and sodium repair tissue NMSI (r = -0.001; P = 0.996). CONCLUSIONS Our results suggest higher glycosaminoglycan (GAG) content, and therefore, repair tissue of better quality in MACT than in BMS patients. Sodium imaging might be beneficial in non-invasive evaluation of cartilage repair surgery efficacy.
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Affiliation(s)
- S Zbýň
- MR Centre-Highfield MR, Department of Radiology, Medical University of Vienna/Vienna General Hospital, Vienna, Austria.
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Wetterling F, Corteville DM, Kalayciyan R, Rennings A, Konstandin S, Nagel AM, Stark H, Schad LR. Whole body sodium MRI at 3T using an asymmetric birdcage resonator and short echo time sequence: first images of a male volunteer. Phys Med Biol 2012; 57:4555-67. [PMID: 22722731 DOI: 10.1088/0031-9155/57/14/4555] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Sodium magnetic resonance imaging (²³Na MRI) is a non-invasive technique which allows spatial resolution of the tissue sodium concentration (TSC) in the human body. TSC measurements could potentially serve to monitor early treatment success of chemotherapy on patients who suffer from whole body metastases. Yet, the acquisition of whole body sodium (²³Na) images has been hampered so far by the lack of large resonators and the extremely low signal-to-noise ratio (SNR) achieved with existing resonator systems. In this study, a ²³Na resonator was constructed for whole body ²³Na MRI at 3T comprising of a 16-leg, asymmetrical birdcage structure with 34 cm height, 47.5 cm width and 50 cm length. The resonator was driven in quadrature mode and could be used either as a transceiver resonator or, since active decoupling was included, as a transmit-only resonator in conjunction with a receive-only (RO) surface resonator. The relative B₁-field profile was simulated and measured on phantoms, and 3D whole body ²³Na MRI data of a healthy male volunteer were acquired in five segments with a nominal isotropic resolution of (6 × 6 × 6) mm³ and a 10 min acquisition time per scan. The measured SNR values in the ²³Na-MR images varied from 9 ± 2 in calf muscle, 15 ± 2 in brain tissue, 23 ± 2 in the prostate and up to 42 ± 5 in the vertebral discs. Arms, legs, knees and hands could also be resolved with applied resonator and short time-to-echo (TE) (0.5 ms) radial sequence. Up to fivefold SNR improvement was achieved through combining the birdcage with local RO surface coil. In conclusion, ²³Na MRI of the entire human body provides sub-cm spatial resolution, which allows resolution of all major human body parts with a scan time of less than 60 min.
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Advanced MR methods at ultra-high field (7 Tesla) for clinical musculoskeletal applications. Eur Radiol 2012; 22:2338-46. [DOI: 10.1007/s00330-012-2508-0] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Revised: 05/02/2012] [Accepted: 05/04/2012] [Indexed: 12/16/2022]
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50
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Boada FE, Qian Y, Nemoto E, Jovin T, Jungreis C, Jones SC, Weimer J, Lee V. Sodium MRI and the assessment of irreversible tissue damage during hyper-acute stroke. Transl Stroke Res 2012; 3:236-45. [PMID: 24323779 DOI: 10.1007/s12975-012-0168-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2012] [Accepted: 03/29/2012] [Indexed: 12/24/2022]
Abstract
Sodium MRI (sMRI) has undergone a tremendous amount of technical development during the last two decades that makes it a suitable tool for the study of human pathology in the acute setting within the constraints of a clinical environment. The salient role of the sodium ion during impaired ATP production during the course of brain ischemia makes sMRI an ideal tool for the study of ischemic tissue viability during stroke. In this paper, the current limitations of conventional MRI for the determination of tissue viability during evolving brain ischemia are discussed. This discussion is followed by a summary of the known findings about the dynamics of tissue sodium changes during brain ischemia. A mechanistic model for the explanation of these findings is presented together with the technical requirements for its investigation using clinical MRI scanners. An illustration of the salient features of the technique is also presented using a nonhuman primate model of reversible middle cerebral artery occlusion.
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Affiliation(s)
- Fernando E Boada
- MR Research Center, Department of Radiology, University of Pittsburgh, Pittsburgh, PA, USA,
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