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Sinha U, Sinha S. Magnetic Resonance Imaging Biomarkers of Muscle. Tomography 2024; 10:1411-1438. [PMID: 39330752 PMCID: PMC11436019 DOI: 10.3390/tomography10090106] [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: 08/03/2024] [Revised: 08/29/2024] [Accepted: 08/30/2024] [Indexed: 09/28/2024] Open
Abstract
This review is focused on the current status of quantitative MRI (qMRI) of skeletal muscle. The first section covers the techniques of qMRI in muscle with the focus on each quantitative parameter, the corresponding imaging sequence, discussion of the relation of the measured parameter to underlying physiology/pathophysiology, the image processing and analysis approaches, and studies on normal subjects. We cover the more established parametric mapping from T1-weighted imaging for morphometrics including image segmentation, proton density fat fraction, T2 mapping, and diffusion tensor imaging to emerging qMRI features such as magnetization transfer including ultralow TE imaging for macromolecular fraction, and strain mapping. The second section is a summary of current clinical applications of qMRI of muscle; the intent is to demonstrate the utility of qMRI in different disease states of the muscle rather than a complete comprehensive survey.
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Affiliation(s)
- Usha Sinha
- Department of Physics, San Diego State University, San Diego, CA 92182, USA
| | - Shantanu Sinha
- Muscle Imaging and Modeling Lab., Department of Radiology, University of California at San Diego, San Diego, CA 92037, USA
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Aptekarev T, Furman G, Badar F, Sokolovsky V, Xia Y. Study of the collagen tissue nanostructure by analyzing the echo decay obtained using the MRI technique. SOFT MATTER 2024; 20:4282-4290. [PMID: 38757720 PMCID: PMC11211971 DOI: 10.1039/d4sm00312h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2024]
Abstract
The multicomponent relaxation observed in nuclear magnetic resonance experiments in biological tissues makes it difficult to establish a correlation between specific relaxation times and tissue structural parameters. The analysis of a nanostructure (the characteristic size of 10-1000 nm) is usually based on formulas for relaxation times which depend on structural parameters at the atomic or molecular levels in the size range of 0.1-5 nm. We have recently developed an analysis method in which relaxation times' anisotropy in a sample is explicitly related to its structure of nanocavities containing a liquid or gas. However, the method is based on the analysis of experimental data on the anisotropy of relaxation times obtained by using the standard NMR technique and rotating the sample relative to a magnetic field and requires a series of experiments. In the present study, to address this challenge, we develop a new method of analysis of a multi-exponential magnetic resonance signal that does not require determining relaxation times and eliminates the sample rotation and the necessity of a series of experiments. Using the magnetic resonance imaging (MRI) technique, the total signal from the whole sample was obtained as a sum of the signals (echo decays) from all voxels. In contrast to previous research, the volumes of nanocavities and their angular distribution can be obtained by analyzing a single total signal for the entire cartilage. In addition, within the framework of this approach, it is possible to identify the reason for the multicomponent nature of relaxation. The proposed method for analyzing a single multi-exponential signal (transverse relaxation) was implemented on cartilage. Using the signal, three anatomical zones of cartilage were studied, revealing significant structural differences between them. The proposed method not only avoids the need for sample rotation but also enables repeated application of layer-by-layer magnetic resonance imaging with micron resolution. The study results allow us to suggest that water molecules contributing to the echo decay are more likely located in nanocavities formed by the fibrillar structure rather than inside the fibrils.
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Affiliation(s)
- Theodore Aptekarev
- Physics Department, Ben Gurion University of the Negev, Beer Sheva, Israel.
| | - Gregory Furman
- Physics Department, Ben Gurion University of the Negev, Beer Sheva, Israel.
| | - Farid Badar
- Physics Department, Oakland University, Rochester, MI, USA
| | | | - Yang Xia
- Physics Department, Oakland University, Rochester, MI, USA
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Sherman SE, Zammit AS, Heo WS, Rosen MS, Cima MJ. Single-sided magnetic resonance-based sensor for point-of-care evaluation of muscle. Nat Commun 2024; 15:440. [PMID: 38199994 PMCID: PMC10782019 DOI: 10.1038/s41467-023-44561-9] [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: 09/12/2023] [Accepted: 12/19/2023] [Indexed: 01/12/2024] Open
Abstract
Magnetic resonance imaging is a widespread clinical tool for the detection of soft tissue morphology and pathology. However, the clinical deployment of magnetic resonance imaging scanners is ultimately limited by size, cost, and space constraints. Here, we discuss the design and performance of a low-field single-sided magnetic resonance sensor intended for point-of-care evaluation of skeletal muscle in vivo. The 11 kg sensor has a penetration depth of >8 mm, which allows for an accurate analysis of muscle tissue and can avoid signal from more proximal layers, including subcutaneous adipose tissue. Low operational power and shielding requirements are achieved through the design of a permanent magnet array and surface transceiver coil. The sensor can acquire high signal-to-noise measurements in minutes, making it practical as a point-of-care tool for many quantitative diagnostic measurements, including T2 relaxometry. In this work, we present the in vitro and human in vivo performance of the device for muscle tissue evaluation.
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Affiliation(s)
- Sydney E Sherman
- Harvard-MIT Program in Health Science and Technology, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Alexa S Zammit
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Won-Seok Heo
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Matthew S Rosen
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston, MA, 02129, USA
- Harvard Medical School, Boston, MA, 02115, USA
- Department of Physics, Harvard University, Cambridge, MA, 02138, USA
| | - Michael J Cima
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
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Cima M, Sherman S, Zammit A, Heo WS, Rosen M. Single-sided magnetic resonance-based sensor for point-of-care evaluation of muscle. RESEARCH SQUARE 2023:rs.3.rs-3335248. [PMID: 37790511 PMCID: PMC10543496 DOI: 10.21203/rs.3.rs-3335248/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
Magnetic resonance (MR) imaging is a powerful clinical tool for the detection of soft tissue morphology and pathology, which often provides actionable diagnostic information to clinicians. Its clinical use is largely limited due to size, cost, time, and space constraints. Here, we discuss the design and performance of a low-field single-sided MR sensor intended for point-of-care (POC) evaluation of skeletal muscle in vivo. The 11kg sensor has a penetration depth of > 8 mm, which allows for an accurate analysis of muscle tissue and can avoid signal from more proximal layers, including subcutaneous adipose tissue. Low operational power and minimal shielding requirements are achieved through the design of a permanent magnet array and surface transceiver coil. We present the in vitro and human in vivo performance of the device for muscle tissue evaluation. The sensor can acquire high signal-to-noise (SNR > 150) measurements in minutes, making it practical as a POC tool for many quantitative diagnostic measurements, including T2 relaxometry.
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Affiliation(s)
| | | | | | | | - Matthew Rosen
- Massachusetts General Hospital and Harvard Medical School
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Omer N, Galun M, Stern N, Blumenfeld-Katzir T, Ben-Eliezer N. Data-driven algorithm for myelin water imaging: Probing subvoxel compartmentation based on identification of spatially global tissue features. Magn Reson Med 2021; 87:2521-2535. [PMID: 34958690 DOI: 10.1002/mrm.29125] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 11/23/2021] [Accepted: 11/26/2021] [Indexed: 01/10/2023]
Abstract
PURPOSE Multicomponent analysis of MRI T2 relaxation time (mcT2 ) is commonly used for estimating myelin content by separating the signal at each voxel into its underlying distribution of T2 values. This voxel-based approach is challenging due to the large ambiguity in the multi-T2 space and the low SNR of MRI signals. Herein, we present a data-driven mcT2 analysis, which utilizes the statistical strength of identifying spatially global mcT2 motifs in white matter segments before deconvolving the local signal at each voxel. METHODS Deconvolution is done using a tailored optimization scheme, which incorporates the global mcT2 motifs without additional prior assumptions regarding the number of microscopic components. The end results of this process are voxel-wise myelin water fraction maps. RESULTS Validations are shown for computer-generated signals, uniquely designed subvoxel mcT2 phantoms, and in vivo human brain. Results demonstrated excellent fitting accuracy, both for the numerical and the physical mcT2 phantoms, exhibiting excellent agreement between calculated myelin water fraction and ground truth. Proof-of-concept in vivo validation is done by calculating myelin water fraction maps for white matter segments of the human brain. Interscan stability of myelin water fraction values was also estimated, showing good correlation between scans. CONCLUSION We conclude that studying global tissue motifs prior to performing voxel-wise mcT2 analysis stabilizes the optimization scheme and efficiently overcomes the ambiguity in the T2 space. This new approach can improve myelin water imaging and the investigation of microstructural compartmentation in general.
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Affiliation(s)
- Noam Omer
- The Department of Biomedical Engineering, Tel-Aviv University, Tel Aviv, Israel
| | - Meirav Galun
- Department of Computer Science and Applied Mathematics, Weitzman Institute of Science, Rehovot, Israel
| | - Neta Stern
- The Department of Biomedical Engineering, Tel-Aviv University, Tel Aviv, Israel
| | | | - Noam Ben-Eliezer
- The Department of Biomedical Engineering, Tel-Aviv University, Tel Aviv, Israel.,Sagol School of Neuroscience, Tel-Aviv University, Tel-Aviv, Israel.,Center for Advanced Imaging Innovation and Research (CAI2R), New York University Langone Medical Center, New York, New York, USA
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Nonparametric D-R 1-R 2 distribution MRI of the living human brain. Neuroimage 2021; 245:118753. [PMID: 34852278 DOI: 10.1016/j.neuroimage.2021.118753] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 11/17/2021] [Accepted: 11/22/2021] [Indexed: 11/23/2022] Open
Abstract
Diffusion-relaxation correlation NMR can simultaneously characterize both the microstructure and the local chemical composition of complex samples that contain multiple populations of water. Recent developments on tensor-valued diffusion encoding and Monte Carlo inversion algorithms have made it possible to transfer diffusion-relaxation correlation NMR from small-bore scanners to clinical MRI systems. Initial studies on clinical MRI systems employed 5D D-R1 and D-R2 correlation to characterize healthy brain in vivo. However, these methods are subject to an inherent bias that originates from not including R2 or R1 in the analysis, respectively. This drawback can be remedied by extending the concept to 6D D-R1-R2 correlation. In this work, we present a sparse acquisition protocol that records all data necessary for in vivo 6D D-R1-R2 correlation MRI across 633 individual measurements within 25 min-a time frame comparable to previous lower-dimensional acquisition protocols. The data were processed with a Monte Carlo inversion algorithm to obtain nonparametric 6D D-R1-R2 distributions. We validated the reproducibility of the method in repeated measurements of healthy volunteers. For a post-therapy glioblastoma case featuring cysts, edema, and partially necrotic remains of tumor, we present representative single-voxel 6D distributions, parameter maps, and artificial contrasts over a wide range of diffusion-, R1-, and R2-weightings based on the rich information contained in the D-R1-R2 distributions.
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Marty B, Reyngoudt H, Boisserie JM, Le Louër J, C A Araujo E, Fromes Y, Carlier PG. Water-Fat Separation in MR Fingerprinting for Quantitative Monitoring of the Skeletal Muscle in Neuromuscular Disorders. Radiology 2021; 300:652-660. [PMID: 34254855 DOI: 10.1148/radiol.2021204028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Background Quantitative MRI is increasingly proposed in clinical trials related to neuromuscular disorders (NMDs). Purpose To investigate the potential of an MR fingerprinting sequence for water and fat fraction (FF) quantification (MRF T1-FF) for providing markers of fatty replacement and disease activity in patients with NMDs and to establish the sensitivity of water T1 as a marker of disease activity compared with water T2 mapping. Materials and Methods Data acquired between March 2018 and March 2020 from the legs of patients with NMDs were retrospectively analyzed. The MRI examination comprised fat-suppressed T2-weighted imaging, mapping of the FF measured with the three-point Dixon technique (FFDixon), water T2 mapping, and MRF T1-FF, from which the FF measured with MRF T1-FF (FFMRF) and water T1 were derived. Data from the legs of healthy volunteers were prospectively acquired between January and July 2020 to derive abnormality thresholds for FF, water T2, and water T1 values. Kruskal-Wallis tests and receiver operating characteristic curve analysis were performed, and linear models were used. Results A total of 73 patients (mean age ± standard deviation, 47 years ± 12; 45 women) and 15 healthy volunteers (mean age, 33 years ± 8; three women) were evaluated. A linear correlation was observed between FFMRF and FFDixon (R2 = 0.97, P < .001). Water T1 values were higher in muscles with high signal intensity at fat-suppressed T2-weighted imaging than in muscles with low signal intensity (mean value, 1281 msec [95% CI: 1165, 1604] vs 1198 msec [95% CI: 1099, 1312], respectively; P < .001), and a correlation was found between water T1 and water T2 distribution metrics (R2 = 0.66 and 0.79 for the median and 90th percentile values, respectively; P < .001). Water T1 classified the patients' muscles as abnormal based on quantitative water T2, with high sensitivity (93%; 68 of 73 patients) and specificity (80%; 53 of 73 patients) (area under the receiver operating characteristic curve, 0.92 [95% CI: 0.83, 0.97]; P < .001). Conclusion Water-fat separation in MR fingerprinting is robust for deriving quantitative imaging markers of intramuscular fatty replacement and disease activity in patients with neuromuscular disorders. © RSNA, 2021 Online supplemental material is available for this article.
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Affiliation(s)
- Benjamin Marty
- From the Nuclear Magnetic Resonance Laboratory, Neuromuscular Investigation Center, Institute of Myology, Bâtiment Babinski, Groupe Hospitalier Pitié-Salpêtrière, 47-83 Blvd Vincent Auriol, 75651 Paris Cedex 13, France; and Nuclear Magnetic Resonance Laboratory, CEA, DRF, IBFJ, Molecular Imaging Research Center, Paris, France
| | - Harmen Reyngoudt
- From the Nuclear Magnetic Resonance Laboratory, Neuromuscular Investigation Center, Institute of Myology, Bâtiment Babinski, Groupe Hospitalier Pitié-Salpêtrière, 47-83 Blvd Vincent Auriol, 75651 Paris Cedex 13, France; and Nuclear Magnetic Resonance Laboratory, CEA, DRF, IBFJ, Molecular Imaging Research Center, Paris, France
| | - Jean-Marc Boisserie
- From the Nuclear Magnetic Resonance Laboratory, Neuromuscular Investigation Center, Institute of Myology, Bâtiment Babinski, Groupe Hospitalier Pitié-Salpêtrière, 47-83 Blvd Vincent Auriol, 75651 Paris Cedex 13, France; and Nuclear Magnetic Resonance Laboratory, CEA, DRF, IBFJ, Molecular Imaging Research Center, Paris, France
| | - Julien Le Louër
- From the Nuclear Magnetic Resonance Laboratory, Neuromuscular Investigation Center, Institute of Myology, Bâtiment Babinski, Groupe Hospitalier Pitié-Salpêtrière, 47-83 Blvd Vincent Auriol, 75651 Paris Cedex 13, France; and Nuclear Magnetic Resonance Laboratory, CEA, DRF, IBFJ, Molecular Imaging Research Center, Paris, France
| | - Ericky C A Araujo
- From the Nuclear Magnetic Resonance Laboratory, Neuromuscular Investigation Center, Institute of Myology, Bâtiment Babinski, Groupe Hospitalier Pitié-Salpêtrière, 47-83 Blvd Vincent Auriol, 75651 Paris Cedex 13, France; and Nuclear Magnetic Resonance Laboratory, CEA, DRF, IBFJ, Molecular Imaging Research Center, Paris, France
| | - Yves Fromes
- From the Nuclear Magnetic Resonance Laboratory, Neuromuscular Investigation Center, Institute of Myology, Bâtiment Babinski, Groupe Hospitalier Pitié-Salpêtrière, 47-83 Blvd Vincent Auriol, 75651 Paris Cedex 13, France; and Nuclear Magnetic Resonance Laboratory, CEA, DRF, IBFJ, Molecular Imaging Research Center, Paris, France
| | - Pierre G Carlier
- From the Nuclear Magnetic Resonance Laboratory, Neuromuscular Investigation Center, Institute of Myology, Bâtiment Babinski, Groupe Hospitalier Pitié-Salpêtrière, 47-83 Blvd Vincent Auriol, 75651 Paris Cedex 13, France; and Nuclear Magnetic Resonance Laboratory, CEA, DRF, IBFJ, Molecular Imaging Research Center, Paris, France
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Menon RG, Raghavan P, Regatte RR. Pilot study quantifying muscle glycosaminoglycan using bi-exponential T 1ρ mapping in patients with muscle stiffness after stroke. Sci Rep 2021; 11:13951. [PMID: 34230600 PMCID: PMC8260636 DOI: 10.1038/s41598-021-93304-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 06/16/2021] [Indexed: 01/14/2023] Open
Abstract
Post stroke muscle stiffness is a common problem, which left untreated can lead to disabling muscle contractures. The purpose of this pilot study was to evaluate the feasibility of bi-exponential T1ρ mapping in patients with arm muscle stiffness after stroke and its ability to measure treatment related changes in muscle glycosaminoglycans (GAGs). Five patients with muscle stiffness after stroke and 5 healthy controls were recruited for imaging of the upper arm with 3D-T1ρ mapping. Patients were scanned before and after treatment with hyaluronidase injections, whereas the controls were scanned once. Wilcoxon Mann-Whitney tests compared patients vs. controls and patients pre-treatment vs. post-treatment. With bi-exponential modeling, the long component, T1ρl was significantly longer in the patients (biceps P = 0.01; triceps P = 0.004) compared to controls. There was also a significant difference in the signal fractions of the long and short components (biceps P = 0.03, triceps P = 0.04). The results suggest that muscle stiffness is characterized by increased muscle free water and GAG content. Post-treatment, the T1ρ parameters shifted toward control values. This pilot study demonstrates the application of bi-exponential T1ρ mapping as a marker for GAG content in muscle and as a potential treatment monitoring tool for patients with muscle stiffness after stroke.
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Affiliation(s)
- Rajiv G Menon
- Bernard and Irene Schwartz Center for Biomedical Imaging, New York University School of Medicine, 660 1st Ave, 4th Floor, New York, NY, 10016, USA.
| | - Preeti Raghavan
- Deparments of Physical Medicine and Rehabilitation and Neurology, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Ravinder R Regatte
- Bernard and Irene Schwartz Center for Biomedical Imaging, New York University School of Medicine, 660 1st Ave, 4th Floor, New York, NY, 10016, USA
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Nguyen HT, Grenier T, Leporq B, Le Goff C, Gilles B, Grange S, Grange R, Millet GP, Beuf O, Croisille P, Viallon M. Quantitative Magnetic Resonance Imaging Assessment of the Quadriceps Changes during an Extreme Mountain Ultramarathon. Med Sci Sports Exerc 2021; 53:869-881. [PMID: 33044438 DOI: 10.1249/mss.0000000000002535] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
INTRODUCTION/PURPOSE Extreme ultra-endurance races are growing in popularity, but their effects on skeletal muscles remain mostly unexplored. This longitudinal study explores physiological changes in mountain ultramarathon athletes' quadriceps using quantitative magnetic resonance imaging (MRI) coupled with serological biomarkers. The study aimed to monitor the longitudinal effect of the race and recovery and to identify local inflammatory and metabolic muscle responses by codetection of biological markers. METHODS An automatic image processing framework was designed to extract imaging-based biomarkers from quantitative MRI acquisitions of the upper legs of 20 finishers at three time points. The longitudinal effect of the race was demonstrated by analyzing the image markers with dedicated biostatistical analysis. RESULTS Our framework allows for a reliable calculation of statistical data not only inside the whole quadriceps volume but also within each individual muscle head. Local changes in MRI parameters extracted from quantitative maps were described and found to be significantly correlated with principal serological biomarkers of interest. A decrease in the PDFF after the race and a stable paramagnetic susceptibility value were found. Pairwise post hoc tests suggested that the recovery process differs among the muscle heads. CONCLUSIONS This longitudinal study conducted during a prolonged and extreme mechanical stress showed that quantitative MRI-based markers of inflammation and metabolic response can detect local changes related to the prolonged exercise, with differentiated involvement of each head of the quadriceps muscle as expected in such eccentric load. Consistent and efficient extraction of the local biomarkers enables to highlight the interplay/interactions between blood and MRI biomarkers. This work indeed proposes an automatized analytic framework to tackle the time-consuming and mentally exhausting segmentation task of muscle heads in large multi-time-point cohorts.
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Affiliation(s)
- Hoai-Thu Nguyen
- Univ-Lyon, UJM-Saint-Etienne, INSA-Lyon, Université Claude Bernard Lyon 1, CNRS, Inserm, Saint-Etienne, FRANCE
| | - Thomas Grenier
- Univ Lyon, INSA-Lyon, Université Claude Bernard Lyon 1, UJM-Saint Etienne, CNRS, Inserm, Villeurbanne, FRANCE
| | - Benjamin Leporq
- Univ Lyon, INSA-Lyon, Université Claude Bernard Lyon 1, UJM-Saint Etienne, CNRS, Inserm, Villeurbanne, FRANCE
| | - Caroline Le Goff
- Department of Clinical Chemistry, University of Liège, CHU Sart-Tilman, Liège, BELGIUM
| | | | | | | | - Grégoire P Millet
- Institute of Sport Sciences, University of Lausanne, Lausanne, SWITZERLAND
| | - Olivier Beuf
- Univ Lyon, INSA-Lyon, Université Claude Bernard Lyon 1, UJM-Saint Etienne, CNRS, Inserm, Villeurbanne, FRANCE
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Wiggermann V, Vavasour IM, Kolind SH, MacKay AL, Helms G, Rauscher A. Non-negative least squares computation for in vivo myelin mapping using simulated multi-echo spin-echo T 2 decay data. NMR IN BIOMEDICINE 2020; 33:e4277. [PMID: 32124505 DOI: 10.1002/nbm.4277] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 01/20/2020] [Accepted: 01/26/2020] [Indexed: 06/10/2023]
Abstract
Multi-compartment T2 mapping has gained particular relevance for the study of myelin water in the brain. As a facilitator of rapid saltatory axonal signal transmission, myelin is a cornerstone indicator of white matter development and function. Regularized non-negative least squares fitting of multi-echo T2 data has been widely employed for the computation of the myelin water fraction (MWF), and the obtained MWF maps have been histopathologically validated. MWF measurements depend upon the quality of the data acquisition, B1+ homogeneity and a range of fitting parameters. In this special issue article, we discuss the relevance of these factors for the accurate computation of multi-compartment T2 and MWF maps. We generated multi-echo spin-echo T2 decay curves following the Carr-Purcell-Meiboom-Gill approach for various myelin concentrations and myelin T2 scenarios by simulating the evolution of the magnetization vector between echoes based on the Bloch equations. We demonstrated that noise and imperfect refocusing flip angles yield systematic underestimations in MWF and intra-/extracellular water geometric mean T2 (gmT2 ). MWF estimates were more stable than myelin water gmT2 time across different settings of the T2 analysis. We observed that the lower limit of the T2 distribution grid should be slightly shorter than TE1 . Both TE1 and the acquisition echo spacing also have to be sufficiently short to capture the rapidly decaying myelin water T2 signal. Among all parameters of interest, the estimated MWF and intra-/extracellular water gmT2 differed by approximately 0.13-4 percentage points and 3-4 ms, respectively, from the true values, with larger deviations observed in the presence of greater B1+ inhomogeneities and at lower signal-to-noise ratio. Tailoring acquisition strategies may allow us to better characterize the T2 distribution, including the myelin water, in vivo.
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Affiliation(s)
- V Wiggermann
- Department of Physics and Astronomy, University of British Columbia, Vancouver, Canada
- Department of Pediatrics, University of British Columbia, Vancouver, Canada
- UBC MRI Research Center, University of British Columbia, Vancouver, Canada
| | - I M Vavasour
- UBC MRI Research Center, University of British Columbia, Vancouver, Canada
- Department of Radiology, University of British Columbia, Vancouver, Canada
| | - S H Kolind
- Department of Physics and Astronomy, University of British Columbia, Vancouver, Canada
- UBC MRI Research Center, University of British Columbia, Vancouver, Canada
- Department of Radiology, University of British Columbia, Vancouver, Canada
- Department of Medicine (Division Neurology), University of British Columbia, Vancouver, Canada
| | - A L MacKay
- Department of Physics and Astronomy, University of British Columbia, Vancouver, Canada
- UBC MRI Research Center, University of British Columbia, Vancouver, Canada
- Department of Radiology, University of British Columbia, Vancouver, Canada
| | - G Helms
- Department of Clinical Sciences Lund (IKVL), Medical Radiation Physics, Lund University, Lund, Sweden
| | - A Rauscher
- Department of Physics and Astronomy, University of British Columbia, Vancouver, Canada
- Department of Pediatrics, University of British Columbia, Vancouver, Canada
- UBC MRI Research Center, University of British Columbia, Vancouver, Canada
- Department of Radiology, University of British Columbia, Vancouver, Canada
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11
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Araujo ECA, Marty B, Carlier PG, Baudin P, Reyngoudt H. Multiexponential Analysis of the Water
T2
‐Relaxation in the Skeletal Muscle Provides Distinct Markers of Disease Activity Between Inflammatory and Dystrophic Myopathies. J Magn Reson Imaging 2020; 53:181-189. [DOI: 10.1002/jmri.27300] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 07/06/2020] [Accepted: 07/08/2020] [Indexed: 11/06/2022] Open
Affiliation(s)
- Ericky C. A. Araujo
- NMR laboratory, Neuromuscular Investigation Center Institute of Myology Paris France
- CEA, DRF, IBFJ, MIRCen Paris France
| | - Benjamin Marty
- NMR laboratory, Neuromuscular Investigation Center Institute of Myology Paris France
- CEA, DRF, IBFJ, MIRCen Paris France
| | - Pierre G. Carlier
- NMR laboratory, Neuromuscular Investigation Center Institute of Myology Paris France
- CEA, DRF, IBFJ, MIRCen Paris France
| | | | - Harmen Reyngoudt
- NMR laboratory, Neuromuscular Investigation Center Institute of Myology Paris France
- CEA, DRF, IBFJ, MIRCen Paris France
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Goldenberg JM, Berthusen AJ, Cárdenas-Rodríguez J, Pagel MD. Differentiation of Myositis-Induced Models of Bacterial Infection and Inflammation with T 2-Weighted, CEST, and DCE-MRI. ACTA ACUST UNITED AC 2020; 5:283-291. [PMID: 31572789 PMCID: PMC6752290 DOI: 10.18383/j.tom.2019.00009] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
We used T2 relaxation, chemical exchange saturation transfer (CEST), and dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) to assess whether bacterial infection can be differentiated from inflammation in a myositis-induced mouse model. We measured the T2 relaxation time constants, %CEST at 5 saturation frequencies, and area under the curve (AUC) from DCE-MRI after maltose injection from infected, inflamed, and normal muscle tissue models. We applied principal component analysis (PCA) to reduce dimensionality of entire CEST spectra and DCE signal evolutions, which were analyzed using standard classification methods. We extracted features from dimensional reduction as predictors for machine learning classifier algorithms. Normal, inflamed, and infected tissues were evaluated with H&E and gram-staining histological studies, and bacterial-burden studies. The T2 relaxation time constants and AUC of DCE-MRI after injection of maltose differentiated infected, inflamed, and normal tissues. %CEST amplitudes at −1.6 and −3.5 ppm differentiated infected tissues from other tissues, but these did not differentiate inflamed tissue from normal tissue. %CEST amplitudes at 3.5, 3.0, and 2.5 ppm, AUC of DCE-MRI for shorter time periods, and relative Ktrans and kep values from DCE-MRI could not differentiate tissues. PCA and machine learning of CEST-MRI and DCE-MRI did not improve tissue classifications relative to traditional analysis methods. Similarly, PCA and machine learning did not further improve tissue classifications relative to T2 MRI. Therefore, future MRI studies of infection models should focus on T2-weighted MRI and analysis of T2 relaxation times.
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Affiliation(s)
- Joshua M Goldenberg
- Department of Pharmaceutical Sciences, University of Arizona, Tucson, AZ.,Department of Genitourinary Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX
| | | | | | - Mark D Pagel
- Department of Cancer Systems Imaging, The University of Texas MD Anderson Cancer Center, Houston, TX
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13
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Keene KR, Beenakker JWM, Hooijmans MT, Naarding KJ, Niks EH, Otto LAM, van der Pol WL, Tannemaat MR, Kan HE, Froeling M. T 2 relaxation-time mapping in healthy and diseased skeletal muscle using extended phase graph algorithms. Magn Reson Med 2020; 84:2656-2670. [PMID: 32306450 PMCID: PMC7496817 DOI: 10.1002/mrm.28290] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 03/06/2020] [Accepted: 03/31/2020] [Indexed: 02/06/2023]
Abstract
PURPOSE Multi-echo spin-echo (MSE) transverse relaxometry mapping using multi-component models is used to study disease activity in neuromuscular disease by assessing the T2 of the myocytic component (T2water ). Current extended phase graph algorithms are not optimized for fat fractions above 50% and the effects of inaccuracies in the T2fat calibration remain unexplored. Hence, we aimed to improve the performance of extended phase graph fitting methods over a large range of fat fractions, by including the slice-selection flip angle profile, a through-plane chemical-shift displacement correction, and optimized calibration of T2fat . METHODS Simulation experiments were used to study the influence of the slice flip-angle profile with chemical-shift and T2fat estimations. Next, in vivo data from four neuromuscular disease cohorts were studied for different T2fat calibration methods and T2water estimations. RESULTS Excluding slice flip-angle profiles or chemical-shift displacement resulted in a bias in T2water up to 10 ms. Furthermore, a wrongly calibrated T2fat caused a bias of up to 4 ms in T2water . For the in vivo data, one-component calibration led to a lower T2fat compared with a two-component method, and T2water decreased with increasing fat fractions. CONCLUSION In vivo data showed a decline in T2water for increasing fat fractions, which has important implications for clinical studies, especially in multicenter settings. We recommend using an extended phase graph-based model for fitting T2water from MSE sequences with two-component T2fat calibration. Moreover, we recommend including the slice flip-angle profile in the model with correction for through-plane chemical-shift displacements.
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Affiliation(s)
- Kevin R Keene
- C.J. Gorter center for high field MRI, Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands.,Department of Neurology, Leiden University Medical Center, Leiden, the Netherlands
| | - Jan-Willem M Beenakker
- C.J. Gorter center for high field MRI, Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands.,Department of Ophthalmology, Leiden University Medical Center, Leiden, the Netherlands
| | | | - Karin J Naarding
- Department of Neurology, Leiden University Medical Center, Leiden, the Netherlands.,Duchenne Center Netherlands, the Netherlands
| | - Erik H Niks
- Department of Neurology, Leiden University Medical Center, Leiden, the Netherlands.,Duchenne Center Netherlands, the Netherlands
| | - Louise A M Otto
- Department of Neurology, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht University, the Netherlands
| | - W Ludo van der Pol
- Department of Neurology, UMC Utrecht Brain Center, University Medical Center Utrecht, Utrecht University, the Netherlands
| | - Martijn R Tannemaat
- Department of Neurology, Leiden University Medical Center, Leiden, the Netherlands
| | - Hermien E Kan
- C.J. Gorter center for high field MRI, Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands.,Duchenne Center Netherlands, the Netherlands
| | - Martijn Froeling
- Department of Radiology, University Medical Center Utrecht, Utrecht, the Netherlands
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14
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Dvorak AV, Wiggermann V, Gilbert G, Vavasour IM, MacMillan EL, Barlow L, Wiley N, Kozlowski P, MacKay AL, Rauscher A, Kolind SH. Multi-spin echo T 2 relaxation imaging with compressed sensing (METRICS) for rapid myelin water imaging. Magn Reson Med 2020; 84:1264-1279. [PMID: 32065474 DOI: 10.1002/mrm.28199] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 12/20/2019] [Accepted: 01/13/2020] [Indexed: 12/11/2022]
Abstract
PURPOSE Myelin water imaging (MWI) provides a valuable biomarker for myelin, but clinical application has been restricted by long acquisition times. Accelerating the standard multi-echo T2 acquisition with gradient echoes (GRASE) or by 2D multi-slice data collection results in image blurring, contrast changes, and other issues. Compressed sensing (CS) can vastly accelerate conventional MRI. In this work, we assessed the use of CS for in vivo human MWI, using a 3D multi spin-echo sequence. METHODS We implemented multi-echo T2 relaxation imaging with compressed sensing (METRICS) and METRICS with partial Fourier acceleration (METRICS-PF). Scan-rescan data were acquired from 12 healthy controls for assessment of repeatability. MWI data were acquired for METRICS in 9 m:58 s and for METRICS-PF in 7 m:25 s, both with 1.5 × 2 × 3 mm3 voxels, 56 echoes, 7 ms ΔTE, and 240 × 240 × 170 mm3 FOV. METRICS was compared with a novel multi-echo spin-echo gold-standard (MSE-GS) MWI acquisition, acquired for a single additional subject in 2 h:2 m:40 s. RESULTS METRICS/METRICS-PF myelin water fraction had mean: repeatability coefficient 1.5/1.1, coefficient of variation 6.2/4.5%, and intra-class correlation coefficient 0.79/0.84. Repeatability metrics comparing METRICS with METRICS-PF were similar, and both sequences agreed with reference values from literature. METRICS images and quantitative maps showed excellent qualitative agreement with those of MSE-GS. CONCLUSION METRICS and METRICS-PF provided highly repeatable MWI data without the inherent disadvantages of GRASE or 2D multi-slice acquisition. CS acceleration allows MWI data to be acquired rapidly with larger FOV, higher estimated SNR, more isotropic voxels and more echoes than with previous techniques. The approach introduced here generalizes to any multi-component T2 mapping application.
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Affiliation(s)
- Adam V Dvorak
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada.,International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, British Columbia, Canada
| | - Vanessa Wiggermann
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada.,Department of Pediatrics, University of British Columbia, Vancouver, British Columbia, Canada.,UBC MRI Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
| | | | - Irene M Vavasour
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada.,Department of Radiology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Erin L MacMillan
- UBC MRI Research Centre, University of British Columbia, Vancouver, British Columbia, Canada.,MR Clinical Science, Philips Canada, Markham, Ontario, Canada.,Department of Radiology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Laura Barlow
- UBC MRI Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
| | - Neale Wiley
- UBC MRI Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
| | - Piotr Kozlowski
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, British Columbia, Canada.,UBC MRI Research Centre, University of British Columbia, Vancouver, British Columbia, Canada.,Department of Radiology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Alex L MacKay
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada.,UBC MRI Research Centre, University of British Columbia, Vancouver, British Columbia, Canada.,Department of Radiology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Alexander Rauscher
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada.,Department of Pediatrics, University of British Columbia, Vancouver, British Columbia, Canada.,UBC MRI Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
| | - Shannon H Kolind
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada.,International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, British Columbia, Canada.,UBC MRI Research Centre, University of British Columbia, Vancouver, British Columbia, Canada.,Department of Radiology, University of British Columbia, Vancouver, British Columbia, Canada.,Division of Neurology, Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
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15
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Bashyam A, Frangieh CJ, Li M, Cima MJ. Dehydration assessment via a portable, single sided magnetic resonance sensor. Magn Reson Med 2019; 83:1390-1404. [PMID: 31631380 DOI: 10.1002/mrm.28004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 08/21/2019] [Accepted: 08/28/2019] [Indexed: 12/20/2022]
Abstract
PURPOSE Undiagnosed dehydration compromises health outcomes across many populations. Existing dehydration diagnostics require invasive bodily fluid sampling or are easily confounded by fluid and electrolyte intake, environment, and physical activity limiting widespread adoption. We present a portable MR sensor designed to measure intramuscular fluid shifts to identify volume depletion. METHODS Fluid loss is induced via a mouse model of thermal dehydration (37°C; 15-20% relative humidity). We demonstrate quantification of fluid loss induced by hyperosmotic dehydration with multicomponent T2 relaxometry using both a benchtop NMR system and MRI localized to skeletal muscle tissue. We then describe a miniaturized (~1000 cm3 ) portable (~4 kg) MR sensor (0.28 T) designed to identify dehydration-induced fluid loss. T2 relaxometry measurements were performed using a Carr-Purcell-Meiboom-Gill pulse sequence in ~4 min. RESULTS T2 values from the portable MR sensor exhibited strong (R2 = 0.996) agreement with benchtop NMR spectrometer. Thermal dehydration induced weight loss of 4 to 11% over 5 to 10 h. Fluid loss induced by thermal dehydration was accurately identified via whole-animal NMR and skeletal muscle. The portable MR sensor accurately identified dehydration via multicomponent T2 relaxometry. CONCLUSION Performing multicomponent T2 relaxometry localized to the skeletal muscle with a miniaturized MR sensor provides a noninvasive, physiologically relevant measure of dehydration induced fluid loss in a mouse model. This approach offers sensor portability, reduced system complexity, fully automated operation, and low cost compared with MRI. This approach may serve as a versatile and portable point of care technique for dehydration monitoring.
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Affiliation(s)
- Ashvin Bashyam
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts.,Department of Electrical Engineering & Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Chris J Frangieh
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts.,Department of Electrical Engineering & Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Matthew Li
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts.,Harvard-MIT Program in Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Michael J Cima
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts.,Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts
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16
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Naughton NM, Georgiadis JG. Global sensitivity analysis of skeletal muscle dMRI metrics: Effects of microstructural and pulse parameters. Magn Reson Med 2019; 83:1458-1470. [DOI: 10.1002/mrm.28014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Revised: 08/26/2019] [Accepted: 09/05/2019] [Indexed: 12/13/2022]
Affiliation(s)
- Noel M. Naughton
- Department of Mechanical Science and Engineering University of Illinois at Urbana‐Champaign Urbana Illinois
| | - John G. Georgiadis
- Department of Mechanical Science and Engineering University of Illinois at Urbana‐Champaign Urbana Illinois
- Department of Biomedical Engineering Illinois Institute of Technology Chicago Illinois
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17
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Schlaeger S, Weidlich D, Klupp E, Montagnese F, Deschauer M, Schoser B, Bublitz S, Ruschke S, Zimmer C, Rummeny EJ, Kirschke JS, Karampinos DC. Decreased water T 2 in fatty infiltrated skeletal muscles of patients with neuromuscular diseases. NMR IN BIOMEDICINE 2019; 32:e4111. [PMID: 31180167 DOI: 10.1002/nbm.4111] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2018] [Revised: 03/07/2019] [Accepted: 03/17/2019] [Indexed: 05/22/2023]
Abstract
Quantitative imaging techniques are emerging in the field of magnetic resonance imaging of neuromuscular diseases (NMD). T2 of water (T2w ) is considered an important imaging marker to assess acute and chronic alterations of the muscle fibers, being generally interpreted as an indicator for "disease activity" in the muscle tissue. To validate the accuracy and robustness of quantitative imaging methods, 1 H magnetic resonance spectroscopy (MRS) can be used as a gold standard. The purpose of the present work was to investigate T2w of remaining muscle tissue in regions of higher proton density fat fraction (PDFF) in 40 patients with defined NMD using multi-TE single-voxel 1 H MRS. Patients underwent MR measurements on a 3 T system to perform a multi-TE single-voxel stimulated echo acquisition method (STEAM) MRS (TE = 11/15/20/25(/35) ms) in regions of healthy, edematous and fatty thigh muscle tissue. Muscle regions for MRS were selected based on T2 -weighted water and fat images of a two-echo 2D Dixon TSE. MRS results were confined to regions with qualitatively defined remaining muscle tissue without edema and high fat content, based on visual grading of the imaging data. The results showed decreased T2w values with increasing PDFF with R2 = 0.45 (p < 10-3 ) (linear fit) and with R2 = 0.51 (exponential fit). The observed dependence of T2w on PDFF should be considered when using T2w as a marker in NMD imaging and when performing single-voxel MRS for T2w in regions enclosing edematous, nonedematous and fatty infiltrated muscle tissue.
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Affiliation(s)
- Sarah Schlaeger
- Department of Diagnostic and Interventional Radiology, Technical University of Munich, Munich, Germany
- Department of Diagnostic and Interventional of Neuroradiology, Technical University of Munich, Munich, Germany
| | - Dominik Weidlich
- Department of Diagnostic and Interventional Radiology, Technical University of Munich, Munich, Germany
| | - Elisabeth Klupp
- Department of Diagnostic and Interventional of Neuroradiology, Technical University of Munich, Munich, Germany
| | - Federica Montagnese
- Friedrich-Baur-Institut, Department of Neurology, Ludwig-Maximilians-University, Munich, Germany
| | - Marcus Deschauer
- Department of Neurology, Technical University of Munich, Munich, Germany
| | - Benedikt Schoser
- Friedrich-Baur-Institut, Department of Neurology, Ludwig-Maximilians-University, Munich, Germany
| | - Sarah Bublitz
- Department of Neurology, Technical University of Munich, Munich, Germany
| | - Stefan Ruschke
- Department of Diagnostic and Interventional Radiology, Technical University of Munich, Munich, Germany
| | - Claus Zimmer
- Department of Diagnostic and Interventional of Neuroradiology, Technical University of Munich, Munich, Germany
| | - Ernst J Rummeny
- Department of Diagnostic and Interventional Radiology, Technical University of Munich, Munich, Germany
| | - Jan S Kirschke
- Department of Diagnostic and Interventional of Neuroradiology, Technical University of Munich, Munich, Germany
| | - Dimitrios C Karampinos
- Department of Diagnostic and Interventional Radiology, Technical University of Munich, Munich, Germany
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18
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Terenzi C, Sederman AJ, Mantle MD, Gladden LF. Spatially-resolved 1H NMR relaxation-exchange measurements in heterogeneous media. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2019; 299:101-108. [PMID: 30593999 DOI: 10.1016/j.jmr.2018.12.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 12/07/2018] [Accepted: 12/13/2018] [Indexed: 06/09/2023]
Abstract
In the last decades, the 1H NMR T2-T2 relaxation-exchange (REXSY) technique has become an essential tool for the molecular investigation of simple and complex fluids in heterogeneous porous solids and soft matter, where the mixing-time-evolution of cross-correlated T2-T2 peaks enables a quantitative study of diffusive exchange kinetics in multi-component systems. Here, we present a spatially-resolved implementation of the T2-T2 correlation technique, named z-T2-T2, based on one-dimensional spatial mapping along z using a rapid frequency-encode imaging scheme. Compared to other phase-encoding methods, the adopted MRI technique has two distinct advantages: (i) is has the same experimental duration of a standard (bulk) T2-T2 measurement, and (ii) it provides a high spatial resolution. The proposed z-T2-T2 method is first validated against bulk T2-T2 measurements on homogeneous phantom consisting of cyclohexane uniformly imbibed in finely-sized α-Al2O3 particles at a spatial resolution of 0.47 mm; thereafter, its performance is demonstrated, on a layered bed of multi-sized α-Al2O3 particles, for revealing spatially-dependent molecular exchange kinetics properties of intra- and inter-particle cyclohexane as a function of particle size. It is found that localised z-T2-T2 spectra provide well resolved cross peaks whilst such resolution is lost in standard bulk T2-T2 data. Future prospective applications of the method lie, in particular, in the local characterisation of mass transport phenomena in multi-component porous media, such as rock cores and heterogeneous catalysts.
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Affiliation(s)
- Camilla Terenzi
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge CB3 0AS, UK
| | - Andrew J Sederman
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge CB3 0AS, UK
| | - Michael D Mantle
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge CB3 0AS, UK.
| | - Lynn F Gladden
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge CB3 0AS, UK
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19
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Malis V, Sinha U, Csapo R, Narici M, Smitaman E, Sinha S. Diffusion tensor imaging and diffusion modeling: Application to monitoring changes in the medial gastrocnemius in disuse atrophy induced by unilateral limb suspension. J Magn Reson Imaging 2018; 49:1655-1664. [PMID: 30569482 DOI: 10.1002/jmri.26295] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Revised: 07/24/2018] [Accepted: 07/26/2018] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Diffusion tensor imaging (DTI) assesses underlying tissue microstructure, and has been applied to studying skeletal muscle. Unloading of the lower leg causes decreases in muscle force, mass, and muscle protein synthesis as well as changes in muscle architecture. PURPOSE To monitor the change in DTI indices in the medial gastrocnemius (MG) after 4-week unilateral limb suspension (ULLS) and to explore the feasibility of extracting tissue microstructural parameters based on a two-compartment diffusion model. STUDY TYPE Prospective cohort study. SUBJECTS Seven moderately active subjects (29.1 ± 5.7 years). FIELD STRENGTH/SEQUENCE 3T, single-shot fat-suppressed echo planar spin echo sequence. ASSESSMENT Suspension-related changes in the DTI indices (eigenvalues: λ1 , λ2 , λ3 , fractional anisotropy; coefficient of planarity) were statistically analyzed. Changes in model-derived tissue parameters (muscle fiber circularity and diameter, intracellular volume fraction, and residence time) after suspension are qualitatively discussed. STATISTICAL TESTS Changes in the DTI indices of the MG between pre- and postsuspension were assessed using repeated-measures two-way analysis of variance (ANOVA). RESULTS All the eigenvalues (λ1 : P = 0.025, λ2 : P = 0.035, λ3 : P = 0.049) as well as anisotropic diffusion coefficient (P = 0.029) were significantly smaller post-ULLS. Diffusion modeling revealed that fibers were more circular (circularity index increased from 0.55 to 0.95) with a smaller diameter (diameter decreased from 82-60 μm) postsuspension. DATA CONCLUSION We have shown that DTI indices change with disuse and modeling can relate these voxel level changes to changes in the tissue microarchitecture. LEVEL OF EVIDENCE 2 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2018.
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Affiliation(s)
- Vadim Malis
- Muscle Imaging and Modeling Lab, Department of Radiology, UC San Diego, San Diego, California, USA.,Physics, UC San Diego, San Diego, California, USA
| | - Usha Sinha
- Physics, San Diego State University, California, USA
| | - Robert Csapo
- Muscle Imaging and Modeling Lab, Department of Radiology, UC San Diego, San Diego, California, USA.,Institute for Sports Medicine, Alpine Medicine and Health Tourism, University for Health Sciences, Medical Informatics and Technology, Hall, Austria
| | - Marco Narici
- School of Graduate Entry Medicine and Health University of Nottingham, Derby, UK
| | - Edward Smitaman
- Department of Radiology, UC San Diego, San Diego, California, USA
| | - Shantanu Sinha
- Muscle Imaging and Modeling Lab, Department of Radiology, UC San Diego, San Diego, California, USA
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20
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Xing S, Freeman CR, Jung S, Turcotte R, Levesque IR. Probabilistic classification of tumour habitats in soft tissue sarcoma. NMR IN BIOMEDICINE 2018; 31:e4000. [PMID: 30113738 DOI: 10.1002/nbm.4000] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 06/27/2018] [Accepted: 07/02/2018] [Indexed: 06/08/2023]
Abstract
The purpose of this work is to propose a method to characterize tumour heterogeneity on MRI, using probabilistic classification based on a reference tissue. The method uses maps of the apparent diffusion coefficient (ADC), T2 relaxation, and a calculated map representing high-b-value diffusion-weighted MRI (denoted simDWI) to identify up to five habitats (i.e. sub-regions) of tumours. In this classification method, the parameter values (ADC, T2 , and simDWI) from each tumour voxel are compared against the corresponding parameter probability distributions in a reference tissue. The probability that a tumour voxel belongs to a specific habitat is the joint probability for all parameters. The classification can be visualized using a custom colour scheme. The proposed method was applied to data from seven patients with biopsy-confirmed soft tissue sarcoma, at three time-points over the course of pre-operative radiotherapy. Fast-spin-echo images with two different echo times and diffusion MRI with three b-values were obtained and used as inputs to the method. Imaging findings were compared with pathology reports from pre-radiotherapy biopsy and post-surgical resection. Regions of hypercellularity, high-T2 proteinaceous fluid, necrosis, collagenous stroma, and fibrosis were identified within soft tissue sarcoma. The classifications were qualitatively consistent with pathological observations. The percentage of necrosis on imaging correlated strongly with necrosis estimated from FDG-PET before radiotherapy (R2 = 0.97) and after radiotherapy (R2 = 0.96). The probabilistic classification method identifies realistic habitats and reflects the complex microenvironment of tumours, as demonstrated in soft tissue sarcoma.
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Affiliation(s)
- Shu Xing
- Medical Physics Unit, McGill University, Montreal, Canada
- Department of Physics, McGill University, Montreal, Canada
| | - Carolyn R Freeman
- Radiation Oncology, McGill University Health Centre, Montreal, Canada
| | - Sungmi Jung
- Department of Pathology, McGill University Health Centre, Montreal, Canada
| | - Robert Turcotte
- Department of Surgery, McGill University Health Centre, Montreal, Canada
| | - Ives R Levesque
- Medical Physics Unit, McGill University, Montreal, Canada
- Department of Physics, McGill University, Montreal, Canada
- Research Institute of the McGill University Health Centre, Montreal, Canada
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21
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Zibetti MVW, Baboli R, Chang G, Otazo R, Regatte RR. Rapid compositional mapping of knee cartilage with compressed sensing MRI. J Magn Reson Imaging 2018; 48:1185-1198. [PMID: 30295344 PMCID: PMC6231228 DOI: 10.1002/jmri.26274] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 07/12/2018] [Indexed: 12/15/2022] Open
Abstract
More than a decade after the introduction of compressed sensing (CS) in MRI, researchers are still working on ways to translate it into different research and clinical applications. The greatest advantage of CS in MRI is the reduced amount of k-space data needed to reconstruct images, which can be exploited to reduce scan time or to improve spatial resolution and volumetric coverage. Efficient data acquisition using CS is extremely important for compositional mapping of the musculoskeletal system in general and knee cartilage mapping techniques in particular. High-resolution quantitative information about tissue biochemical composition could be obtained in just a few minutes using CS MRI. However, in order to make this goal a reality, some issues still need to be addressed. In this article we review the current state of the art of CS methods for rapid compositional mapping of knee cartilage. Specifically, data acquisition strategies, image reconstruction algorithms, and data fitting models are discussed. Different CS studies for T2 and T1ρ mapping of knee cartilage are reviewed, with illustrative results. Future directions, opportunities, and challenges of rapid compositional mapping techniques are also discussed. Level of Evidence: 4 Technical Efficacy: Stage 6 J. Magn. Reson. Imaging 2018;47:1185-1198.
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Affiliation(s)
- Marcelo V W Zibetti
- Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, USA
| | - Rahman Baboli
- Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, USA
| | - Gregory Chang
- Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, USA
| | - Ricardo Otazo
- Memorial Sloan-Kettering Cancer Center, New York, NY, USA
| | - Ravinder R Regatte
- Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, USA
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22
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Park JS, Vohra R, Klussmann T, Bengtsson NE, Chamberlain JS, Lee D. Non-invasive tracking of disease progression in young dystrophic muscles using multi-parametric MRI at 14T. PLoS One 2018; 13:e0206323. [PMID: 30365532 PMCID: PMC6203357 DOI: 10.1371/journal.pone.0206323] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 10/10/2018] [Indexed: 12/02/2022] Open
Abstract
In this study, multi-parametric magnetic resonance imaging (MRI) was conducted to monitor skeletal muscle changes in dystrophic (mdx4cv) and age-matched control (C57BL/6J) mice starting at 3 weeks of age. The objective of this study was to evaluate and characterize changes in muscle tissue characteristics of hind limbs in young, dystrophic mice using MRI. Mdx4cv (n = 25) and age-matched C57BL/6J (n = 5) were imaged at 3, 5, 7, 9, and 11 weeks of age. Multiple MR measurements were taken from the tibialis anterior, gastrocnemius, and soleus muscles. There were significant differences between dystrophic and control groups for all three muscle types when comparing transverse relaxation times (T2) in lower hind limb muscles. Additionally, fractional anisotropy, radial diffusivity, and eigenvalue analysis of diffusion tensor imaging also demonstrated significant differences between groups. Longitudinal relaxation times (T1) displayed no significant differences between groups. The earliest time points in the magnetization transfer ratio measurements displayed a significant difference. Histological analysis revealed significant differences in the tibialis anterior and gastrocnemius muscles between groups with the mdx mice displaying greater variability in muscle fiber size in later time points. The multi-parametric MRI approach offers a promising alternative for future development of a noninvasive avenue for tracking both disease progression and treatment response.
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Affiliation(s)
- Joshua S. Park
- Department of Radiology, University of Washington, Seattle, WA, United States of America
| | - Ravneet Vohra
- Department of Radiology, University of Washington, Seattle, WA, United States of America
| | - Thomas Klussmann
- Department of Radiology, University of Washington, Seattle, WA, United States of America
| | - Niclas E. Bengtsson
- Department of Neurology, University of Washington, Seattle, WA, United States of America
- Senator Paul D. Wellstone Muscular Dystrophy Cooperative Research Center, University of Washington, Seattle, WA, United States of America
| | - Jeffrey S. Chamberlain
- Department of Neurology, University of Washington, Seattle, WA, United States of America
- Senator Paul D. Wellstone Muscular Dystrophy Cooperative Research Center, University of Washington, Seattle, WA, United States of America
- Department of Biochemistry, University of Washington, Seattle, WA, United States of America
- Department of Medicine, University of Washington, Seattle, WA, United States of America
| | - Donghoon Lee
- Department of Radiology, University of Washington, Seattle, WA, United States of America
- * E-mail:
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23
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Zhang Y, Wells SA, Hernando D. Stimulated echo based mapping (STEM) of T 1 , T 2 , and apparent diffusion coefficient: validation and protocol optimization. Magn Reson Med 2018; 81:167-181. [PMID: 30024051 DOI: 10.1002/mrm.27358] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Revised: 04/18/2018] [Accepted: 04/23/2018] [Indexed: 01/06/2023]
Abstract
PURPOSE To present a stimulated-echo based mapping (STEM) approach for simultaneous T1 , T2 , and ADC mapping. METHODS Diffusion-weighted stimulated-echo images with various combinations of mixing time (TM), TE, and b-value were acquired to enable simultaneous mapping of T1 , T2 , and ADC. The proposed STEM method was performed by densely sampling the TM-TE-b space in a phantom and in brain and prostate of healthy volunteers. T1 , T2 , and ADC from STEM were compared to reference mapping methods. Additionally, protocol optimization was performed to enable rapid STEM acquisition within 2 min by sparsely sampling the TM-TE-b space. The T1 , T2 , and ADC measurements from rapid acquisitions were compared to the densely sampled STEM for evaluation. Finally, a patient with biopsy-proven high-risk prostate cancer was imaged to demonstrate the ability of STEM to differentiate cancer and healthy tissues. RESULTS Relative to the reference measurements, densely sampled STEM provided accurate quantitative T1 , T2 , and ADC mapping in phantoms (R2 = 0.999, slope between 0.97-1.03), as well as in brain and prostate. Further, the T1 , T2 , and ADC measurements from the optimized rapid STEM acquisitions agreed closely with densely sampled STEM. Finally, STEM showed decreased T2 and ADC in prostate cancer compared to healthy prostate tissue. CONCLUSION STEM provides accurate simultaneous mapping of T1 , T2 , and ADC. This method may enable rapid and accurate multi-parametric tissue characterization for clinical and research applications.
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Affiliation(s)
- Yuxin Zhang
- Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin.,Department of Radiology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin
| | - Shane A Wells
- Department of Radiology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin
| | - Diego Hernando
- Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin.,Department of Radiology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin
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24
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Kerch G. Distribution of tightly and loosely bound water in biological macromolecules and age-related diseases. Int J Biol Macromol 2018; 118:1310-1318. [PMID: 29981332 DOI: 10.1016/j.ijbiomac.2018.06.187] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 05/21/2018] [Accepted: 06/29/2018] [Indexed: 02/06/2023]
Abstract
This mini-review article is focused on publications devoted to the changes in water binding energy and content of bound water in biological tissues during aging processes, when bound water lost from the hydration layer becomes free water. Bound water is released during cataractogenesis. In skin, water bound to proteins and other biomacromolecules becomes more mobile with increasing skin age. Extracellular to intracellular water ratio increases with age and was associated with muscle cell atrophy. Bound water concentration decreases with age in hydrated human bone and can be correlated with the strength and toughness of the bone. Higher fraction of free water in malignant tissues compared to normal tissues was observed. Hydration water mobility is enhanced around tau amyloid fibers. Water plays a decisive role in amyloid formation as entropic driving force. In the natural aging processes dehydration and glycation may be considered as subsequent steps.
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Affiliation(s)
- G Kerch
- Institute of Polymer Materials, Department of Materials Science and Applied Chemistry, Riga Technical University, Azenes 14/24, Riga, Latvia.
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25
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Sigmund EE, Baete SH, Patel K, Wang D, Stoffel D, Otazo R, Parasoglou P, Bencardino J. Spatially resolved kinetics of skeletal muscle exercise response and recovery with multiple echo diffusion tensor imaging (MEDITI): a feasibility study. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2018; 31:599-608. [PMID: 29761414 DOI: 10.1007/s10334-018-0686-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 03/26/2018] [Accepted: 04/23/2018] [Indexed: 12/20/2022]
Abstract
OBJECTIVES We describe measurement of skeletal muscle kinetics with multiple echo diffusion tensor imaging (MEDITI). This approach allows characterization of the microstructural dynamics in healthy and pathologic muscle. MATERIALS AND METHODS In a Siemens 3-T Skyra scanner, MEDITI was used to collect dynamic DTI with a combination of rapid diffusion encoding, radial imaging, and compressed sensing reconstruction in a multi-compartment agarose gel rotation phantom and within in vivo calf muscle. An MR-compatible ergometer (Ergospect Trispect) was employed to enable in-scanner plantar flexion exercise. In a HIPAA-compliant study with written informed consent, post-exercise recovery of DTI metrics was quantified in eight volunteers. Exercise response of DTI metrics was compared with that of T2-weighted imaging and characterized by a gamma variate model. RESULTS Phantom results show quantification of diffusivities in each compartment over its full dynamic rotation. In vivo calf imaging results indicate larger radial than axial exercise response and recovery in the plantar flexion-challenged gastrocnemius medialis (fractional response: nT2w = 0.385 ± 0.244, nMD = 0.163 ± 0.130, nλ1 = 0.110 ± 0.093, nλrad = 0.303 ± 0.185). Diffusion and T2-weighted response magnitudes were correlated (e.g., r = 0.792, p = 0.019 for nMD vs. nT2w). CONCLUSION We have demonstrated the feasibility of MEDITI for capturing spatially resolved diffusion tensor data in dynamic systems including post-exercise skeletal muscle recovery following in-scanner plantar flexion.
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Affiliation(s)
- E E Sigmund
- Department of Radiology, New York University Langone Health, New York, NY, USA. .,Center for Advanced Imaging and Innovation (CAI2R), New York University Langone Health, New York, NY, USA.
| | - S H Baete
- Department of Radiology, New York University Langone Health, New York, NY, USA.,Center for Advanced Imaging and Innovation (CAI2R), New York University Langone Health, New York, NY, USA
| | - K Patel
- Department of Radiology, New York University Langone Health, New York, NY, USA.,NYU Tandon School of Engineering, Brooklyn, NY, USA
| | - D Wang
- Department of Radiology, New York University Langone Health, New York, NY, USA.,NYU Tandon School of Engineering, Brooklyn, NY, USA
| | - D Stoffel
- Department of Radiology, New York University Langone Health, New York, NY, USA.,Center for Advanced Imaging and Innovation (CAI2R), New York University Langone Health, New York, NY, USA
| | - R Otazo
- Department of Radiology, New York University Langone Health, New York, NY, USA.,Center for Advanced Imaging and Innovation (CAI2R), New York University Langone Health, New York, NY, USA.,Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - P Parasoglou
- Department of Radiology, New York University Langone Health, New York, NY, USA.,Center for Advanced Imaging and Innovation (CAI2R), New York University Langone Health, New York, NY, USA
| | - J Bencardino
- Department of Radiology, New York University Langone Health, New York, NY, USA
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26
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Carlier PG, Marty B, Scheidegger O, Loureiro de Sousa P, Baudin PY, Snezhko E, Vlodavets D. Skeletal Muscle Quantitative Nuclear Magnetic Resonance Imaging and Spectroscopy as an Outcome Measure for Clinical Trials. J Neuromuscul Dis 2018; 3:1-28. [PMID: 27854210 PMCID: PMC5271435 DOI: 10.3233/jnd-160145] [Citation(s) in RCA: 127] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Recent years have seen tremendous progress towards therapy of many previously incurable neuromuscular diseases. This new context has acted as a driving force for the development of novel non-invasive outcome measures. These can be organized in three main categories: functional tools, fluid biomarkers and imagery. In the latest category, nuclear magnetic resonance imaging (NMRI) offers a considerable range of possibilities for the characterization of skeletal muscle composition, function and metabolism. Nowadays, three NMR outcome measures are frequently integrated in clinical research protocols. They are: 1/ the muscle cross sectional area or volume, 2/ the percentage of intramuscular fat and 3/ the muscle water T2, which quantity muscle trophicity, chronic fatty degenerative changes and oedema (or more broadly, “disease activity”), respectively. A fourth biomarker, the contractile tissue volume is easily derived from the first two ones. The fat fraction maps most often acquired with Dixon sequences have proven their capability to detect small changes in muscle composition and have repeatedly shown superior sensitivity over standard functional evaluation. This outcome measure will more than likely be the first of the series to be validated as an endpoint by regulatory agencies. The versatility of contrast generated by NMR has opened many additional possibilities for characterization of the skeletal muscle and will result in the proposal of more NMR biomarkers. Ultra-short TE (UTE) sequences, late gadolinium enhancement and NMR elastography are being investigated as candidates to evaluate skeletal muscle interstitial fibrosis. Many options exist to measure muscle perfusion and oxygenation by NMR. Diffusion NMR as well as texture analysis algorithms could generate complementary information on muscle organization at microscopic and mesoscopic scales, respectively. 31P NMR spectroscopy is the reference technique to assess muscle energetics non-invasively during and after exercise. In dystrophic muscle, 31P NMR spectrum at rest is profoundly perturbed, and several resonances inform on cell membrane integrity. Considerable efforts are being directed towards acceleration of image acquisitions using a variety of approaches, from the extraction of fat content and water T2 maps from one single acquisition to partial matrices acquisition schemes. Spectacular decreases in examination time are expected in the near future. They will reinforce the attractiveness of NMR outcome measures and will further facilitate their integration in clinical research trials.
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Affiliation(s)
- Pierre G Carlier
- Institute of Myology, Pitie-Salpetriere University Hospital, Paris, France.,CEA, DSV, I2BM, MIRCen, NMR Laboratory, Paris, France.,National Academy of Sciences, United Institute for Informatics Problems, Minsk, Belarus
| | - Benjamin Marty
- Institute of Myology, Pitie-Salpetriere University Hospital, Paris, France.,CEA, DSV, I2BM, MIRCen, NMR Laboratory, Paris, France
| | - Olivier Scheidegger
- Institute of Myology, Pitie-Salpetriere University Hospital, Paris, France.,Support Center for Advanced Neuroimaging (SCAN), Institute of Diagnostic and Interventional Neuroradiology, Inselspital, Bern University Hospital, and University of Bern, Switzerland
| | | | | | - Eduard Snezhko
- National Academy of Sciences, United Institute for Informatics Problems, Minsk, Belarus
| | - Dmitry Vlodavets
- N.I. Prirogov Russian National Medical Research University, Clinical Research Institute of Pediatrics, Moscow, Russian Federation
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27
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Sharafi A, Chang G, Regatte RR. Bi-component T1ρ and T2 Relaxation Mapping of Skeletal Muscle In-Vivo. Sci Rep 2017; 7:14115. [PMID: 29074883 PMCID: PMC5658335 DOI: 10.1038/s41598-017-14581-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Accepted: 10/12/2017] [Indexed: 12/26/2022] Open
Abstract
The goal of this paper was to evaluate the possibility of bi-component T1ρ and T2 relaxation mapping of human skeletal muscle at 3 T in clinically feasible scan times. T1ρ- and T2-weighted images of calf muscle were acquired using a modified 3D-SPGR sequence on a standard 3 T clinical MRI scanner. The mono- and biexponential models were fitted pixel-wise to the series of T1ρ and T2 weighted images. The biexponential decay of T1ρ and T2 relaxations was detected in ~30% and ~40% of the pixels across all volunteers, respectively. Monoexponential and bi-exponential short and long T1ρ relaxation times were estimated to be 26.9 ms, 4.6 ms (fraction 22%) and 33.2 ms (fraction: 78%), respectively. Similarly, the mono- and bi-exponential short and long T2 relaxation times were 24.7 ms, 4.2 ms (fraction 15%) and 30.4 ms (fraction 85%) respectively. The experiments had good repeatability with RMSCV < 15% and ICC > 60%. This approach could potentially be used in exercise intervention studies or in studies of inflammatory myopathies or muscle fibrosis, permitting greater sensitivity and specificity via measurement of different water compartments and their fractions.
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Affiliation(s)
- Azadeh Sharafi
- Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, USA.
| | - Gregory Chang
- Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, USA
| | - Ravinder R Regatte
- Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, USA
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28
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Alghamdi S, Sinclair B, Cowin G, Brereton I, Tesiram YA. Magnetic resonance spin-spin relaxation time estimation in a rat model of fatty liver disease. J Magn Reson Imaging 2017. [PMID: 28639264 DOI: 10.1002/jmri.25786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE To compare mono- and bi-exponential relaxation model equations to discriminate between normal and fatty liver disease. MATERIALS AND METHODS Six rats on a choline deficient amino acid modified (CDAA) diet and six on normal chow were studied. Multiple spin echo images with increasing echo times (TEs) were collected at 9.4T. Pixel-wise T2 maps were generated using mono-exponential decay function to calculate T2M , and a bi-exponential to calculate, short T2 component (T2S ), long T2 component (T2L ), and fractions of these components (ρS , ρL ), respectively. Statistical F-tests and Akaike's information criterion (AIC) were used to assess the relative performance of the two models. RESULTS F-test and AIC showed that in the CDAA group, T2 bi-exponential model described the signal of T2 weighted imaging of the liver better than the mono-exponential model. Controls were best described by the mono-exponential model. Mean values for T2M , T2L , T2S , ρS , ρL were 31.2 ± 0.7 ms, 72.8 ± 3.3 ms, 8.2 ± 0.6 ms,71.2 ± 2.1%, 30.4 ± 1.3%, respectively, in CDAA rats, compared with 18.8 ± 0.5 ms, 32.3 ± 0.7 ms, 9.2 ± 1.8 ms, 79 ± 2%, 21.0 ± 1.1% in controls. CONCLUSION In the fatty liver of CDAA rats we have shown that T2 weighted images fit the bi-exponential model better than mono-exponential decays thus providing a better description of the data. LEVEL OF EVIDENCE 1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;47:468-476.
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Affiliation(s)
- Sami Alghamdi
- The University of Queensland, Centre for Advanced Imaging, Brisbane, Queensland, Australia.,College of Applied Medical Science, King Saud University, Riyadh, Saudi Arabia
| | - Benjamin Sinclair
- The University of Queensland, Centre for Advanced Imaging, Brisbane, Queensland, Australia
| | - Gary Cowin
- The University of Queensland, Centre for Advanced Imaging, Brisbane, Queensland, Australia
| | - Ian Brereton
- The University of Queensland, Centre for Advanced Imaging, Brisbane, Queensland, Australia
| | - Yasvir A Tesiram
- The University of Queensland, Centre for Advanced Imaging, Brisbane, Queensland, Australia
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29
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Siracusano G, La Corte A, Milazzo C, Anastasi GP, Finocchio G, Gaeta M. On the R 2⁎ relaxometry in complex multi-peak multi-Echo chemical shift-based water-fat quantification: Applications to the neuromuscular diseases. Magn Reson Imaging 2016; 35:4-14. [PMID: 27569370 DOI: 10.1016/j.mri.2016.08.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2016] [Revised: 08/03/2016] [Accepted: 08/20/2016] [Indexed: 12/31/2022]
Abstract
PURPOSE Investigation of the feasibility of the R2⁎ mapping techniques by using latest theoretical models corrected for confounding factors and optimized for signal to noise ratio. THEORY AND METHODS The improvement of the performance of state of the art magnetic resonance imaging (MRI) relaxometry algorithms is challenging because of a non-negligible bias and still unresolved numerical instabilities. Here, R2⁎ mapping reconstructions, including complex fitting with multi-spectral fat-correction by using single-decay and double-decay formulation, are deeply studied in order to investigate and identify optimal configuration parameters and minimize the occurrence of numerical artifacts. The effects of echo number, echo spacing, and fat/water relaxation model type are evaluated through both simulated and in-vivo data. We also explore the stability and feasibility of the fat/water relaxation model by analyzing the impact of high percentage of fat infiltrations and local transverse relaxation differences among biological species. RESULTS The main limits of the MRI relaxometry are the presence of bias and the occurrence of artifacts, which significantly affect its accuracy. Chemical-shift complex R2⁎-correct single-decay reconstructions exhibit a large bias in presence of a significant difference in the relaxation rates of fat and water and with fat concentration larger than 30%. We find that for fat-dominated tissues or in patients affected by extensive iron deposition, MRI reconstructions accounting for multi-exponential relaxation time provide accurate R2⁎ measurements and are less prone to numerical artifacts. CONCLUSIONS Complex fitting and fat-correction with multi-exponential decay formulation outperforms the conventional single-decay approximation in various diagnostic scenarios. Although it still lacks of numerical stability, which requires model enhancement and support from spectroscopy, it offers promising perspectives for the development of relaxometry as a reliable tool to improve tissue characterization and monitoring of neuromuscular disorders.
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Affiliation(s)
- Giulio Siracusano
- Department of Mathematical and Computer Sciences, Physical Sciences and Earth Sciences, University of Messina, V.le F. D'alcontres, 31, 98166, Messina, Italy; Department of Computer Engineering and Telecommunications, University of Catania, Viale Andrea Doria 6, 95125, Catania, Italy.
| | - Aurelio La Corte
- Department of Computer Engineering and Telecommunications, University of Catania, Viale Andrea Doria 6, 95125, Catania, Italy
| | - Carmelo Milazzo
- Department of Biomedical sciences, Dental and of Morphological and Functional images, University of Messina, Via Consolare Valeria 1, 98125, Messina, Italy
| | - Giuseppe Pio Anastasi
- Department of Biomedical sciences, Dental and of Morphological and Functional images, University of Messina, Via Consolare Valeria 1, 98125, Messina, Italy
| | - Giovanni Finocchio
- Department of Mathematical and Computer Sciences, Physical Sciences and Earth Sciences, University of Messina, V.le F. D'alcontres, 31, 98166, Messina, Italy; Istituto Nazionale di Geofisica e Vulcanologia (INGV), Via Vigna Murata 605, 00143, Roma, Italy
| | - Michele Gaeta
- Department of Biomedical sciences, Dental and of Morphological and Functional images, University of Messina, Via Consolare Valeria 1, 98125, Messina, Italy
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30
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Damon BM, Li K, Bryant ND. Magnetic resonance imaging of skeletal muscle disease. HANDBOOK OF CLINICAL NEUROLOGY 2016; 136:827-42. [PMID: 27430444 DOI: 10.1016/b978-0-444-53486-6.00041-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Neuromuscular diseases often exhibit a temporally varying, spatially heterogeneous, and multifaceted pathology. The goals of this chapter are to describe and evaluate the use of quantitative magnetic resonance imaging (MRI) methods to characterize muscle pathology. The following criteria are used for this evaluation: objective measurement of continuously distributed variables; clear and well-understood relationship to the pathology of interest; sensitivity to improvement or worsening of clinical status; and the measurement properties of accuracy and precision. Two major classes of MRI methods meet all of these criteria: (1) MRI methods for measuring muscle contractile volume or cross-sectional area by combining structural MRI and quantitative fat-water MRI; and (2) an MRI method for characterizing the edema caused by inflammation, the measurement of the transverse relaxation time constant (T2). These methods are evaluated with respect to the four criteria listed above and examples from neuromuscular disorders are provided. Finally, these methods are summarized and synthesized and recommendations for additional quantitative MRI developments are made.
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Affiliation(s)
- Bruce M Damon
- Vanderbilt University Institute of Imaging Science and the Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, USA; Departments of Biomedical Engineering and Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA.
| | - Ke Li
- Vanderbilt University Institute of Imaging Science and the Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, USA
| | - Nathan D Bryant
- Vanderbilt University Institute of Imaging Science and the Department of Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, USA
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31
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Zaccagnini G, Palmisano A, Canu T, Maimone B, Lo Russo FM, Ambrogi F, Gaetano C, De Cobelli F, Del Maschio A, Esposito A, Martelli F. Magnetic Resonance Imaging Allows the Evaluation of Tissue Damage and Regeneration in a Mouse Model of Critical Limb Ischemia. PLoS One 2015; 10:e0142111. [PMID: 26554362 PMCID: PMC4640853 DOI: 10.1371/journal.pone.0142111] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Accepted: 10/16/2015] [Indexed: 12/18/2022] Open
Abstract
Magnetic resonance imaging (MRI) provides non-invasive, repetitive measures in the same individual, allowing the study of a physio-pathological event over time. In this study, we tested the performance of 7 Tesla multi-parametric MRI to monitor the dynamic changes of mouse skeletal muscle injury and regeneration upon acute ischemia induced by femoral artery dissection. T2-mapping (T2 relaxation time), diffusion-tensor imaging (Fractional Anisotropy) and perfusion by Dynamic Contrast-Enhanced MRI (K-trans) were measured and imaging results were correlated with histological morphometric analysis in both Gastrocnemius and Tibialis anterior muscles. We found that tissue damage positively correlated with T2-relaxation time, while myofiber regeneration and capillary density positively correlated with Fractional Anisotropy. Interestingly, K-trans positively correlated with capillary density. Accordingly, repeated MRI measurements between day 1 and day 28 after surgery in ischemic muscles showed that: 1) T2-relaxation time rapidly increased upon ischemia and then gradually declined, returning almost to basal level in the last phases of the regeneration process; 2) Fractional Anisotropy dropped upon ischemic damage induction and then recovered along with muscle regeneration and neoangiogenesis; 3) K-trans reached a minimum upon ischemia, then progressively recovered. Overall, Gastrocnemius and Tibialis anterior muscles displayed similar patterns of MRI parameters dynamic, with more marked responses and less variability in Tibialis anterior. We conclude that MRI provides quantitative information about both tissue damage after ischemia and the subsequent vascular and muscle regeneration, accounting for the differences between subjects and, within the same individual, between different muscles.
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Affiliation(s)
- Germana Zaccagnini
- Molecular Cardiology Laboratory, IRCCS-Policlinico San Donato, San Donato Milanese, Milan, Italy
| | - Anna Palmisano
- Preclinical Imaging Facility, Experimental Imaging Center, San Raffaele Scientific Institute, Milan, Italy
- Vita-Salute San Raffaele University, Milan, Italy
| | - Tamara Canu
- Preclinical Imaging Facility, Experimental Imaging Center, San Raffaele Scientific Institute, Milan, Italy
| | - Biagina Maimone
- Molecular Cardiology Laboratory, IRCCS-Policlinico San Donato, San Donato Milanese, Milan, Italy
| | - Francesco M. Lo Russo
- Preclinical Imaging Facility, Experimental Imaging Center, San Raffaele Scientific Institute, Milan, Italy
- Vita-Salute San Raffaele University, Milan, Italy
| | - Federico Ambrogi
- Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - Carlo Gaetano
- Division of Cardiovascular Epigenetics, Department of Cardiology, Internal Medicine Clinic III, Goethe University, Frankfurt am Main, Germany
| | - Francesco De Cobelli
- Preclinical Imaging Facility, Experimental Imaging Center, San Raffaele Scientific Institute, Milan, Italy
- Vita-Salute San Raffaele University, Milan, Italy
| | - Alessandro Del Maschio
- Preclinical Imaging Facility, Experimental Imaging Center, San Raffaele Scientific Institute, Milan, Italy
- Vita-Salute San Raffaele University, Milan, Italy
| | - Antonio Esposito
- Preclinical Imaging Facility, Experimental Imaging Center, San Raffaele Scientific Institute, Milan, Italy
- Vita-Salute San Raffaele University, Milan, Italy
- * E-mail: (AE); (FM)
| | - Fabio Martelli
- Molecular Cardiology Laboratory, IRCCS-Policlinico San Donato, San Donato Milanese, Milan, Italy
- * E-mail: (AE); (FM)
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32
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Vohra R, Accorsi A, Kumar A, Walter G, Girgenrath M. Magnetic Resonance Imaging Is Sensitive to Pathological Amelioration in a Model for Laminin-Deficient Congenital Muscular Dystrophy (MDC1A). PLoS One 2015; 10:e0138254. [PMID: 26379183 PMCID: PMC4575026 DOI: 10.1371/journal.pone.0138254] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Accepted: 08/27/2015] [Indexed: 11/27/2022] Open
Abstract
Purpose To elucidate the reliability of MRI as a non-invasive tool for assessing in vivo muscle health and pathological amelioration in response to Losartan (Angiotensin II Type 1 receptor blocker) in DyW mice (mouse model for Laminin-deficient Congenital Muscular Dystrophy Type 1A). Methods Multiparametric MR quantifications along with histological/biochemical analyses were utilized to measure muscle volume and composition in untreated and Losartan-treated 7-week old DyW mice. Results MRI shows that DyW mice have significantly less hind limb muscle volume and areas of hyperintensity that are absent in WT muscle. DyW mice also have significantly elevated muscle levels (suggestive of inflammation and edema). Muscle T2 returned to WT levels in response to Losartan treatment. When considering only muscle pixels without T2 elevation, DyW T2 levels are significantly lower than WT (suggestive of fibrosis) whereas Losartan-treated animals do not demonstrate this decrease in muscle T2. MRI measurements suggestive of elevated inflammation and fibrosis corroborate with increased Mac-1 positive cells as well as increased Picrosirius red staining/COL1a gene expression that is returned to WT levels in response to Losartan. Conclusions MRI is sensitive to and tightly corresponds with pathological changes in DyW mice and thus is a viable and effective non-invasive tool for assessing pathological changes.
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MESH Headings
- Angiotensin II Type 1 Receptor Blockers/pharmacology
- Animals
- Disease Models, Animal
- Fibrosis/drug therapy
- Fibrosis/metabolism
- Fibrosis/pathology
- Laminin/metabolism
- Losartan/pharmacology
- Magnetic Resonance Imaging/methods
- Mice
- Muscle, Skeletal/drug effects
- Muscle, Skeletal/metabolism
- Muscle, Skeletal/pathology
- Muscular Dystrophies/drug therapy
- Muscular Dystrophies/metabolism
- Muscular Dystrophies/pathology
- Muscular Dystrophies, Limb-Girdle/diet therapy
- Muscular Dystrophies, Limb-Girdle/metabolism
- Muscular Dystrophies, Limb-Girdle/pathology
- Muscular Dystrophy, Animal/drug therapy
- Muscular Dystrophy, Animal/metabolism
- Muscular Dystrophy, Animal/pathology
- Reproducibility of Results
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Affiliation(s)
- Ravneet Vohra
- Department of Physiology and Functional Genomics, College of Medicine, University of Florida, Gainesville, FL, United States of America
| | - Anthony Accorsi
- Department of Health Sciences, Sargent College, Boston University, Boston, MA, United States of America
| | - Ajay Kumar
- Department of Health Sciences, Sargent College, Boston University, Boston, MA, United States of America
| | - Glenn Walter
- Department of Physiology and Functional Genomics, College of Medicine, University of Florida, Gainesville, FL, United States of America
| | - Mahasweta Girgenrath
- Department of Health Sciences, Sargent College, Boston University, Boston, MA, United States of America
- * E-mail:
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33
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Baete SH, Cho GY, Sigmund EE. Dynamic diffusion-tensor measurements in muscle tissue using the single-line multiple-echo diffusion-tensor acquisition technique at 3T. NMR IN BIOMEDICINE 2015; 28:667-78. [PMID: 25900166 PMCID: PMC4433040 DOI: 10.1002/nbm.3296] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Revised: 02/10/2015] [Accepted: 03/09/2015] [Indexed: 05/05/2023]
Abstract
When diffusion biomarkers display transient changes, i.e. in muscle following exercise, traditional diffusion-tensor imaging (DTI) methods lack the temporal resolution to resolve the dynamics. This article presents an MRI method for dynamic diffusion-tensor acquisitions on a clinical 3T scanner. This method, the Single-Line Multiple-Echo Diffusion-Tensor Acquisition Technique (SL-MEDITATE), achieves a high temporal resolution (4 s) by rapid diffusion encoding through the acquisition of multiple echoes with unique diffusion sensitization and limiting the readout to a single line volume. The method is demonstrated in a rotating anisotropic phantom, a flow phantom with adjustable flow speed and in vivo skeletal calf muscle of healthy volunteers following a plantar flexion exercise. The rotating and flow-varying phantom experiments show that SL-MEDITATE correctly identifies the rotation of the first diffusion eigenvector and the changes in diffusion-tensor parameter magnitudes, respectively. Immediately following exercise, the in vivo mean diffusivity (MD) time courses show, before the well-known increase, an initial decrease that is not typically observed in traditional DTI. In conclusion, SL-MEDITATE can be used to capture transient changes in tissue anisotropy in a single line. Future progress might allow for dynamic DTI when combined with appropriate k-space trajectories and compressed sensing reconstruction.
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Affiliation(s)
- Steven H Baete
- Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, NYU Langone Medical Center, New York, NY, USA
| | - Gene Y Cho
- Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, NYU Langone Medical Center, New York, NY, USA
- Sackler Institute of Graduate Biomedical Sciences, NYU School of Medicine, New York, NY, USA
| | - Eric E Sigmund
- Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, NYU Langone Medical Center, New York, NY, USA
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Park J, Wicki J, Knoblaugh SE, Chamberlain JS, Lee D. Multi-parametric MRI at 14T for muscular dystrophy mice treated with AAV vector-mediated gene therapy. PLoS One 2015; 10:e0124914. [PMID: 25856443 PMCID: PMC4391935 DOI: 10.1371/journal.pone.0124914] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Accepted: 03/11/2015] [Indexed: 01/22/2023] Open
Abstract
The objective of this study was to investigate the efficacy of using quantitative magnetic resonance imaging (MRI) as a non-invasive tool for the monitoring of gene therapy for muscular dystrophy. The clinical investigations for this family of diseases often involve surgical biopsy which limits the amount of information that can be obtained due to the invasive nature of the procedure. Thus, other non-invasive tools may provide more opportunities for disease assessment and treatment responses. In order to explore this, dystrophic mdx4cv mice were systemically treated with a recombinant adeno-associated viral (AAV) vector containing a codon-optimized micro-dystrophin gene. Multi-parametric MRI of T2, magnetization transfer, and diffusion effects alongside 3-D volume measurements were then utilized to monitor disease/treatment progression. Mice were imaged at 10 weeks of age for pre-treatment, then again post-treatment at 8, 16, and 24 week time points. The efficacy of treatment was assessed by physiological assays for improvements in function and quantification of expression. Tissues from the hindlimbs were collected for histological analysis after the final time point for comparison with MRI results. We found that introduction of the micro-dystrophin gene restored some aspects of normal muscle histology and pathology such as decreased necrosis and resistance to contraction-induced injury. T2 relaxation values showed percentage decreases across all muscle types measured (tibialis anterior, gastrocnemius, and soleus) when treated groups were compared to untreated groups. Additionally, the differences between groups were statistically significant for the tibialis anterior as well. The diffusion measurements showed a wider range of percentage changes and less statistical significance while the magnetization transfer effect measurements showed minimal change. MR images displayed hyper-intense regions of muscle that correlated with muscle pathology in histological sections. T2 relaxation, alongside diffusion and magnetization transfer effects provides useful data towards the goal of non-invasively monitoring the treatment of muscular dystrophy.
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Affiliation(s)
- Joshua Park
- Department of Radiology, University of Washington, Seattle, Washington, United States of America
| | - Jacqueline Wicki
- Department of Neurology, University of Washington, Seattle, Washington, United States of America
| | - Sue E. Knoblaugh
- Comparative Medicine Shared Resources, Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | - Jeffrey S. Chamberlain
- Department of Neurology, University of Washington, Seattle, Washington, United States of America
- Department of Biochemistry, University of Washington, Seattle, Washington, United States of America
- Department of Medicine, University of Washington, Seattle, Washington, United States of America
| | - Donghoon Lee
- Department of Radiology, University of Washington, Seattle, Washington, United States of America
- * E-mail:
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Quantitative T2 combined with texture analysis of nuclear magnetic resonance images identify different degrees of muscle involvement in three mouse models of muscle dystrophy: mdx, Largemyd and mdx/Largemyd. PLoS One 2015; 10:e0117835. [PMID: 25710816 PMCID: PMC4339395 DOI: 10.1371/journal.pone.0117835] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Accepted: 01/01/2015] [Indexed: 11/19/2022] Open
Abstract
Quantitative nuclear magnetic resonance imaging (MRI) has been considered a promising non-invasive tool for monitoring therapeutic essays in small size mouse models of muscular dystrophies. Here, we combined MRI (anatomical images and transverse relaxation time constant—T2—measurements) to texture analyses in the study of four mouse strains covering a wide range of dystrophic phenotypes. Two still unexplored mouse models of muscular dystrophies were analyzed: The severely affected Largemyd mouse and the recently generated and worst double mutant mdx/Largemyd mouse, as compared to the mildly affected mdx and normal mice. The results were compared to histopathological findings. MRI showed increased intermuscular fat and higher muscle T2 in the three dystrophic mouse models when compared to the wild-type mice (T2: mdx/Largemyd: 37.6±2.8 ms; mdx: 35.2±4.5 ms; Largemyd: 36.6±4.0 ms; wild-type: 29.1±1.8 ms, p<0.05), in addition to higher muscle T2 in the mdx/Largemyd mice when compared to mdx (p<0.05). The areas with increased muscle T2 in the MRI correlated spatially with the identified histopathological alterations such as necrosis, inflammation, degeneration and regeneration foci. Nevertheless, muscle T2 values were not correlated with the severity of the phenotype in the 3 dystrophic mouse strains, since the severely affected Largemyd showed similar values than both the mild mdx and worst mdx/Largemyd lineages. On the other hand, all studied mouse strains could be unambiguously identified with texture analysis, which reflected the observed differences in the distribution of signals in muscle MRI. Thus, combined T2 intensity maps and texture analysis is a powerful approach for the characterization and differentiation of dystrophic muscles with diverse genotypes and phenotypes. These new findings provide important noninvasive tools in the evaluation of the efficacy of new therapies, and most importantly, can be directly applied in human translational research.
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Björk M, Zachariah D, Kullberg J, Stoica P. A multicomponent T2 relaxometry algorithm for myelin water imaging of the brain. Magn Reson Med 2015; 75:390-402. [PMID: 25604436 DOI: 10.1002/mrm.25583] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Revised: 11/19/2014] [Accepted: 11/25/2014] [Indexed: 12/20/2022]
Abstract
PURPOSE Models based on a sum of damped exponentials occur in many applications, particularly in multicomponent T2 relaxometry. The problem of estimating the relaxation parameters and the corresponding amplitudes is known to be difficult, especially as the number of components increases. In this article, the commonly used non-negative least squares spectrum approach is compared to a recently published estimation algorithm abbreviated as Exponential Analysis via System Identification using Steiglitz-McBride. METHODS The two algorithms are evaluated via simulation, and their performance is compared to a statistical benchmark on precision given by the Cramér-Rao bound. By applying the algorithms to an in vivo brain multi-echo spin-echo dataset, containing 32 images, estimates of the myelin water fraction are computed. RESULTS Exponential Analysis via System Identification using Steiglitz-McBride is shown to have superior performance when applied to simulated T2 relaxation data. For the in vivo brain, Exponential Analysis via System Identification using Steiglitz-McBride gives an myelin water fraction map with a more concentrated distribution of myelin water and less noise, compared to non-negative least squares. CONCLUSION The Exponential Analysis via System Identification using Steiglitz-McBride algorithm provides an efficient and user-parameter-free alternative to non-negative least squares for estimating the parameters of multiple relaxation components and gives a new way of estimating the spatial variations of myelin in the brain.
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Affiliation(s)
- Marcus Björk
- Department of Information Technology, Uppsala University, Uppsala, Sweden
| | - Dave Zachariah
- Department of Information Technology, Uppsala University, Uppsala, Sweden
| | - Joel Kullberg
- Department of Radiology, Uppsala University, Uppsala, Sweden
| | - Petre Stoica
- Department of Information Technology, Uppsala University, Uppsala, Sweden
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Sigmund EE, Novikov DS, Sui D, Ukpebor O, Baete S, Babb JS, Liu K, Feiweier T, Kwon J, Mcgorty K, Bencardino J, Fieremans E. Time-dependent diffusion in skeletal muscle with the random permeable barrier model (RPBM): application to normal controls and chronic exertional compartment syndrome patients. NMR IN BIOMEDICINE 2014; 27:519-28. [PMID: 24610770 PMCID: PMC3980069 DOI: 10.1002/nbm.3087] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2013] [Revised: 12/13/2013] [Accepted: 01/10/2014] [Indexed: 05/11/2023]
Abstract
The purpose of this work was to carry out diffusion tensor imaging (DTI) at multiple diffusion times Td in skeletal muscle in normal subjects and chronic exertional compartment syndrome (CECS) patients and analyze the data with the random permeable barrier model (RPBM) for biophysical specificity. Using an institutional review board approved HIPAA-compliant protocol, seven patients with clinical suspicion of CECS and eight healthy volunteers underwent DTI of the calf muscle in a Siemens MAGNETOM Verio 3 T scanner at rest and after treadmill exertion at four different T(d) values. Radial diffusion values λ(rad) were computed for each of seven different muscle compartments and analyzed with RPBM to produce estimates of free diffusivity D(0), fiber diameter a, and permeability κ. Fiber diameter estimates were compared with measurements from literature autopsy reference for several compartments. Response factors (post/pre-exercise ratios) were computed and compared between normal controls and CECS patients using a mixed-model two-way analysis of variance. All subjects and muscle compartments showed nearly time-independent diffusion along and strongly time-dependent diffusion transverse to the muscle fibers. RPBM estimates of fiber diameter correlated well with corresponding autopsy reference. D(0) showed significant (p < 0.05) increases with exercise for volunteers, and a increased significantly (p < 0.05) in volunteers. At the group level, response factors of all three parameters showed trends differentiating controls from CECS patients, with patients showing smaller diameter changes (p = 0.07), and larger permeability increases (p = 0.07) than controls. Time-dependent diffusion measurements combined with appropriate tissue modeling can provide enhanced microstructural specificity for in vivo tissue characterization. In CECS patients, our results suggest that high-pressure interfiber edema elevates free diffusion and restricts exercise-induced fiber dilation. Such specificity may be useful in differentiating CECS from other disorders or in predicting its response to either physical therapy or fasciotomy.
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Affiliation(s)
- Eric E. Sigmund
- Department of Radiology, New York University Langone Medical Center, New York, NY USA
| | - Dmitry S. Novikov
- Department of Radiology, New York University Langone Medical Center, New York, NY USA
| | - Dabang Sui
- Department of Radiology, New York University Langone Medical Center, New York, NY USA
- Shanghai Tongyue Leasing Co., Ltd., Shanghai City, China
| | - Obehi Ukpebor
- Department of Radiology, New York University Langone Medical Center, New York, NY USA
- Brooklyn College of the City of New York, New York, NY USA
| | - Steven Baete
- Department of Radiology, New York University Langone Medical Center, New York, NY USA
| | - James S. Babb
- Division of Biostatistics, New York University Langone Medical Center, New York, NY USA
| | - Kecheng Liu
- Department of Neurology, Epilepsy Center, New York University Langone Medical Center, New York, NY USA
| | | | - Jane Kwon
- Department of Radiology, New York University Langone Medical Center, New York, NY USA
- Department of Neurology, Epilepsy Center, New York University Langone Medical Center, New York, NY USA
| | - KellyAnne Mcgorty
- Department of Radiology, New York University Langone Medical Center, New York, NY USA
- New York Presbyterian Hospital-Columbia University Medical Center, New York NY USA
| | - Jenny Bencardino
- Department of Radiology, New York University Langone Medical Center, New York, NY USA
| | - Els Fieremans
- Department of Radiology, New York University Langone Medical Center, New York, NY USA
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Assessment of diffusion tensor imaging indices in calf muscles following postural change from standing to supine position. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2013; 27:387-95. [DOI: 10.1007/s10334-013-0424-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2013] [Revised: 11/14/2013] [Accepted: 11/15/2013] [Indexed: 10/26/2022]
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Adriaensen H, Musse M, Quellec S, Vignaud A, Cambert M, Mariette F. MSE-MRI sequence optimisation for measurement of bi- and tri-exponential T2 relaxation in a phantom and fruit. Magn Reson Imaging 2013; 31:1677-89. [DOI: 10.1016/j.mri.2013.02.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2012] [Revised: 01/22/2013] [Accepted: 02/20/2013] [Indexed: 10/27/2022]
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Wang N, Xia Y. Experimental issues in the measurement of multi-component relaxation times in articular cartilage by microscopic MRI. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2013; 235:15-25. [PMID: 23916991 PMCID: PMC3775938 DOI: 10.1016/j.jmr.2013.07.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Revised: 07/02/2013] [Accepted: 07/03/2013] [Indexed: 05/21/2023]
Abstract
A number of experimental issues in the measurement of multi-component T2 and T1ρ relaxations in native and enzymatically digested articular cartilage were investigated by microscopic MRI (μMRI). The issues included the bath solutions (physiological saline and phosphate buffered saline (PBS)), the imaging resolution (35-140 μm), the specimen orientations (0° and 55°), and the strength of spin-lock frequencies (0.5-2 kHz) in the T1ρ experiments. In addition to cartilage, the samples of agar gel and doped water solution were also used in the investigation. Two imaging sequences were used: CPMG-SE and MSME. All raw data were analyzed by the non-negative least square (NNLS) method. The MSME sequence was shown to result in the observation of multi-component T2, even in the gel and liquid samples, demonstrating the artificial uncleanness of this sequence in the multi-component measurements. The soaking of cartilage in PBS reduced the observable T2 components to one at both 0° and 55°, suggesting the effect of phosphate ions on proton exchange between different pools of water molecules. The cartilage orientation with respect to the external magnetic field and the spin-lock strengths in the T1ρ experiment both affected the quantification of the multi-component relaxation. The transitions between a mono-component and multi-components in cartilage under various experimental conditions call for the extra caution in interpreting the relaxation results.
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Affiliation(s)
| | - Yang Xia
- Corresponding Author and Address: Yang Xia, PhD, Department of Physics, Oakland University, Rochester, Michigan 48309, USA, Phone: (248) 370-3420, Fax: (248) 370-3408,
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Kim HK, Lindquist DM, Serai SD, Mariappan YK, Wang LL, Merrow AC, McGee KP, Ehman RL, Laor T. Magnetic resonance imaging of pediatric muscular disorders: recent advances and clinical applications. Radiol Clin North Am 2013; 51:721-42. [PMID: 23830795 PMCID: PMC3950969 DOI: 10.1016/j.rcl.2013.03.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
This review describes various quantitative magnetic resonance imaging techniques that can be used to objectively analyze the composition (T2 relaxation time mapping, Dixon imaging, and diffusion-weighted imaging), architecture (diffusion tensor imaging), mechanical properties (magnetic resonance elastography), and function (magnetic resonance spectroscopy) of normal and pathologic skeletal muscle in the pediatric population.
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Affiliation(s)
- Hee Kyung Kim
- Department of Radiology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, MLC 5031, Cincinnati, OH 45229, USA.
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Esposito A, Campana L, Palmisano A, De Cobelli F, Canu T, Santarella F, Colantoni C, Monno A, Vezzoli M, Pezzetti G, Manfredi AA, Rovere-Querini P, Del Maschio A. Magnetic resonance imaging at 7T reveals common events in age-related sarcopenia and in the homeostatic response to muscle sterile injury. PLoS One 2013; 8:e59308. [PMID: 23555016 PMCID: PMC3595251 DOI: 10.1371/journal.pone.0059308] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2012] [Accepted: 02/15/2013] [Indexed: 01/01/2023] Open
Abstract
Skeletal muscle remodeling in response to various noxae physiologically includes structural changes and inflammatory events. The possibility to study those phenomena in-vivo has been hampered by the lack of validated imaging tools. In our study, we have relied on multiparametric magnetic resonance imaging for quantitative monitoring of muscle changes in mice experiencing age-related sarcopenia or active regeneration after sterile acute injury of tibialis anterior muscle induced by cardiotoxin (CTX) injection. The extent of myofibrils’ necrosis, leukocyte infiltration, and regeneration have been evaluated and compared with parameters from magnetic resonance imaging: T2-mapping (T2 relaxation time; T2-rt), diffusion-tensor imaging (fractional anisotropy, F.A.) and diffusion weighted imaging (apparent diffusion coefficient, ADC). Inflammatory leukocytes within the perimysium and heterogeneous size of fibers characterized aged muscles. They displayed significantly increased T2-rt (P<0.05) and F.A. (P<0.05) compared with young muscles. After acute damage T2-rt increased in otherwise healthy young muscles with a peak at day 3, followed by a progressive decrease to basal values. F.A. dropped 24 hours after injury and afterward increased above the basal level in the regenerated muscle (from day 7 to day 15) returning to the basal value at the end of the follow up period. The ADC displayed opposite kinetics. T2-rt positively correlated with the number of infiltrating leucocytes retrieved by immunomagnetic bead sorting from the tissue (r = 0.92) and with the damage/infiltration score (r = 0.88) while F.A. correlated with the extent of tissue regeneration evaluated at various time points after injury (r = 0.88). Our results indicate that multiparametric MRI is a sensitive and informative tool for monitoring inflammatory and structural muscle changes in living experimental animals; particularly, it allows identifying the increase of T2-rt and F.A. as common events reflecting inflammatory infiltration and muscle regeneration in the transient response of the tissue to acute injury and in the persistent adaptation to aging.
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Affiliation(s)
- Antonio Esposito
- Department of Radiology and Preclinical MR and US Facility of Experimental Imaging Center, San Raffaele Scientific Institute, Milano, Italy.
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Hollingsworth KG, de Sousa PL, Straub V, Carlier PG. Towards harmonization of protocols for MRI outcome measures in skeletal muscle studies: consensus recommendations from two TREAT-NMD NMR workshops, 2 May 2010, Stockholm, Sweden, 1-2 October 2009, Paris, France. Neuromuscul Disord 2013; 22 Suppl 2:S54-67. [PMID: 22980769 DOI: 10.1016/j.nmd.2012.06.005] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- Kieren G Hollingsworth
- Newcastle Magnetic Resonance Centre, Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, UK
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Sigmund EE, Sui D, Ukpebor O, Baete S, Fieremans E, Babb JS, Mechlin M, Liu K, Kwon J, McGorty K, Hodnett PA, Bencardino J. Stimulated echo diffusion tensor imaging and SPAIR T2 -weighted imaging in chronic exertional compartment syndrome of the lower leg muscles. J Magn Reson Imaging 2013; 38:1073-82. [PMID: 23440764 DOI: 10.1002/jmri.24060] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2012] [Accepted: 01/10/2013] [Indexed: 12/20/2022] Open
Abstract
PURPOSE To evaluate the performance of diffusion tensor imaging (DTI) in the evaluation of chronic exertional compartment syndrome (CECS) as compared to T2 -weighted (T2w) imaging. MATERIALS AND METHODS Using an Institutional Review Board (IRB)-approved, Health Insurance Portability and Accountability Act (HIPAA)-compliant protocol, spectral adiabatic inversion recovery (SPAIR) T2w imaging and stimulated echo DTI were applied to eight healthy volunteers and 14 suspected CECS patients before and after exertion. Longitudinal and transverse diffusion eigenvalues, mean diffusivity (MD), and fractional anisotropy (FA) were measured in seven calf muscle compartments, which in patients were classified by their response on T2w: normal (<20% change), and CECS (>20% change). Mixed model analysis of variance compared subject groups and compartments in terms of response factors (post/pre-exercise ratios) of DTI parameters. RESULTS All diffusivities significantly increased (P < 0.0001) and FA decreased (P = 0.0014) with exercise. Longitudinal diffusion responses were significantly smaller than transversal diffusion responses (P < 0.0001). Nineteen of 98 patient compartments were classified as CECS on T2w. MD increased by 3.8 ± 3.4% (volunteer), 7.4 ± 4.2% (normal), and 9.1 ± 7.0% (CECS) with exercise. CONCLUSION DTI shows promise as an ancillary imaging method in the diagnosis and understanding of the pathophysiology in CECS. Future studies may explore its utility in predicting response to treatment.
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Affiliation(s)
- Eric E Sigmund
- Department of Radiology, New York University Langone Medical Center, New York, New York, USA
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Wang N, Xia Y. Anisotropic analysis of multi-component T2 and T1ρ relaxations in achilles tendon by NMR spectroscopy and microscopic MRI. J Magn Reson Imaging 2013; 38:625-33. [PMID: 23349070 DOI: 10.1002/jmri.24012] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Accepted: 12/03/2012] [Indexed: 12/21/2022] Open
Abstract
PURPOSE To study the anisotropic characteristics of both multi-component T2 and T1ρ relaxation times in tendon. MATERIALS AND METHODS T2 and T1ρ were measured in tendon by NMR spectroscopy at different orientations and by microscopic MRI at the magic angle. Several experimental issues in the multi-component relaxation measurements were investigated, including the effects of echo spacing, the resolution of MRI experiments, the influence of the specimen orientations, and the strengths of different spin-lock frequencies in T1ρ experiments. RESULTS Both the values and fractions of T2 in tendon showed significant orientational dependence. The values and fractions of T1ρ strongly depended on both the specimen orientation and the spin-lock strength. The imaging resolution (35-280 μm) had little influence in the T2 experiments. Both the echo spacings (0.6-3.0 ms) in the T2 experiment and the spin-lock strengths (0.5-5 kHz) in the T1ρ experiment affected the quantification of the multi-component relaxation. Up to three T2 and T1ρ components were resolved in tendon. CONCLUSION Multi-component relaxations could be attributed to different populations of water in the tissue. The transitions between a mono-component and multi-component result call for the caution in interpreting the relaxation results.
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Affiliation(s)
- Nian Wang
- Department of Physics and Center for Biomedical Research, Oakland University, Rochester, Michigan 48309, USA
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Scalera JE, Soto JA, Jara H, Ozonoff A, O'Brien M, Anderson SW. Multiexponential T(2) analyses in a murine model of hepatic fibrosis at 11.7 T MRI. NMR IN BIOMEDICINE 2013; 26:83-90. [PMID: 22674663 DOI: 10.1002/nbm.2822] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2011] [Revised: 03/06/2012] [Accepted: 04/18/2012] [Indexed: 06/01/2023]
Abstract
This study evaluated the effects of hepatic fibrosis on the multiexponential T(2) (MET(2) ) relaxation of ex vivo murine liver specimens using an 11.7 T MRI. This animal study was approved by the Institutional Animal Care and Use Committee. Eighteen male C57BL/6 mice were divided into control (n = 3) and experimental (n = 15) groups; the latter group was fed a 3,5-dicarbethoxy-1,4-dihydrocollidine-supplemented diet to induce hepatic fibrosis. Ex vivo liver specimens were imaged using an 11.7 T MRI scanner. A multi-echo spin-echo sequence was utilized for subsequent MET(2) analysis. Degrees of fibrosis were determined by a pathologist, as well as by digital image analysis. Scatterplot graphs comparing various features of the MET(2) signal decay with the degrees of fibrosis were generated, and correlation coefficients were calculated. Two distinct peaks of the MET(2) signal decay were identified in all liver specimens: a short T(2) component with a geometric mean T(2) (GMT(2) ) approximating 30 ms; and a long T(2) component with GMT(2) approximating 400 ms. Strong correlation was found between the degree of hepatic fibrosis and the amplitude of the short T(2) component, with a higher degrees of fibrosis associated with a lower amplitude. Moderate correlation was also found between hepatic fibrosis and the GMT(2) values of the long T(2) component, with higher degrees of fibrosis associated with lower GMT(2) values. The study of hepatic microenvironments using MET(2) analyses offers potential utility in the ongoing development of the noninvasive assessment of hepatic fibrosis using MRI.
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Affiliation(s)
- Jonathan E Scalera
- Boston University Medical Center, Department of Radiology, Boston, MA, USA
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Solis LR, Twist E, Seres P, Thompson RB, Mushahwar VK. Prevention of deep tissue injury through muscle contractions induced by intermittent electrical stimulation after spinal cord injury in pigs. J Appl Physiol (1985) 2012; 114:286-96. [PMID: 23172030 DOI: 10.1152/japplphysiol.00257.2012] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Deep tissue injury (DTI) is a severe medical complication that commonly affects those with spinal cord injury. It is caused by prolonged external loading of the muscles, entrapping them between a bony prominence and the support surface. The entrapment causes excessive mechanical deformation and increases in interstitial pressure, leading to muscle breakdown deep around the bony prominences. We proposed the use of intermittent electrical stimulation (IES) as a novel prophylactic method for the prevention of DTI. In this study, we assessed the long-term effectiveness of this technique in pigs that had received a partial spinal cord injury that paralyzed one hindlimb. The pigs recovered for 2 wk postsurgery, and subsequently, their paralyzed limbs were loaded to 25% of their body weights 4 h/day for 4 consecutive days each week for 1 mo. One group of pigs (n = 3) received IES during the loading, whereas another group (n = 3) did not. DTI was quantified using magnetic resonance imaging (MRI) and postmortem histology. In the group that did not receive IES, MRI assessments revealed signs of tissue damage in 48% of the volume of the loaded muscle. In the group that did receive IES, only 8% of the loaded muscle volume showed signs of tissue damage. Similar findings were found through postmortem histology. This study demonstrates, for the first time, that IES may be an effective technique for preventing the formation of DTI in loaded muscles after spinal cord injury.
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Affiliation(s)
- Leandro R Solis
- Rehabilitation Science Program, Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, Alberta, Canada
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Clinical significance of T2 mapping MRI for the evaluation of masseter muscle pain in patients with temporomandibular joint disorders. Oral Radiol 2012. [DOI: 10.1007/s11282-012-0108-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Yuan J, Zhao F, Chan Q, Wang YXJ. Observation of bi-exponential T(1ρ) relaxation of in-vivo rat muscles at 3T. Acta Radiol 2012; 53:675-81. [PMID: 22761346 DOI: 10.1258/ar.2012.120108] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
BACKGROUND Spin-lattice relaxation in the rotating frame, or T(1ρ) relaxation, is normally described by a mono-exponential decay model. However, compartmentation of tissues and microscopic molecular exchange may lead to bi-exponential or multi-exponential T(1ρ) relaxation behavior in certain tissues under the application of spin lock pulse field strength. PURPOSE To investigate the presence of bi-exponential T(1ρ) relaxations in in-vivo rat head tissues of brain and muscle. MATERIAL AND METHODS Five Sprague-Dawley rats underwent T(1ρ) imaging at 3T. A B(1)-insensitive rotary echo spin lock pulse was used for T(1ρ) preparation with a spin lock frequency of 500Hz. Twenty-five T(1ρ)-weighted images with spin lock times ranging from 1 to 60 ms were acquired using a 3D spoiled gradient echo sequence. Image intensities over different spin lock times were fitted using mono-exponential as well as bi-exponential models both on region-of-interest basis and pixel-by-pixel basis. F-test with a significance level P value of 0.01 was used to evaluate whether bi-exponential model gave a better fitting than mono-exponential model. RESULTS In rat brains, only mono-exponential but no apparent bi-exponential T(1ρ) relaxation (~70-71 ms) was found. In contrast, bi-exponential T(1ρ) relaxation was observed in muscles of all five rats (P < 10(-4)). A longer and a shorter T(1ρ) relaxation component were extracted to be ~37- ~41 ms (a fraction of ~80- ~88%) and ~9- ~11 ms (~12-20%), compared to the normal single T(1ρ) relaxation of ~30- ~33 ms. CONCLUSION Bi-exponential relaxation components were detected in rat muscles. The long and the short T(1ρ) relaxation component are thought to correspond to the restricted intracellular water population and the hydrogen exchange between amine and hydroxyl groups, respectively.
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Affiliation(s)
- Jing Yuan
- Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong
| | - Feng Zhao
- Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong
| | - Queenie Chan
- Philips Healthcare, Philips Electronics Hong Kong Limited, Hong Kong, China
| | - Yi-Xiang J Wang
- Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong
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Cermak NM, Noseworthy MD, Bourgeois JM, Tarnopolsky MA, Gibala MJ. Diffusion tensor MRI to assess skeletal muscle disruption following eccentric exercise. Muscle Nerve 2012; 46:42-50. [DOI: 10.1002/mus.23276] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/06/2011] [Indexed: 12/24/2022]
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