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Lohezic M, Teh I, Bollensdorff C, Peyronnet R, Hales PW, Grau V, Kohl P, Schneider JE. Interrogation of living myocardium in multiple static deformation states with diffusion tensor and diffusion spectrum imaging. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2014; 115:213-25. [PMID: 25117498 PMCID: PMC4210665 DOI: 10.1016/j.pbiomolbio.2014.08.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Accepted: 08/02/2014] [Indexed: 11/27/2022]
Abstract
Diffusion tensor magnetic resonance imaging (MRI) reveals valuable insights into tissue histo-anatomy and microstructure, and has steadily gained traction in the cardiac community. Its wider use in small animal cardiac imaging in vivo has been constrained by its extreme sensitivity to motion, exaggerated by the high heart rates usually seen in rodents. Imaging of the isolated heart eliminates respiratory motion and, if conducted on arrested hearts, cardiac pulsation. This serves as an important intermediate step for basic and translational studies. However, investigating the micro-structural basis of cardiac deformation in the same heart requires observations in different deformation states. Here, we illustrate the imaging of isolated rat hearts in three mechanical states mimicking diastole (cardioplegic arrest), left-ventricular (LV) volume overload (cardioplegic arrest plus LV balloon inflation), and peak systole (lithium-induced contracture). An optimised MRI-compatible Langendorff perfusion setup with the radio-frequency (RF) coil integrated into the wet chamber was developed for use in a 9.4T horizontal bore scanner. Signal-to-noise ratio improved significantly, by 75% compared to a previous design with external RF coil, and stability tests showed no significant changes in mean T1, T2 or LV wall thickness over a 170 min period. In contracture, we observed a significant reduction in mean fractional anisotropy from 0.32 ± 0.02 to 0.28 ± 0.02, as well as a significant rightward shift in helix angles with a decrease in the proportion of left-handed fibres, as referring to the locally prevailing cell orientation in the heart, from 24.9% to 23.3%, and an increase in the proportion of right-handed fibres from 25.5% to 28.4%. LV overload, in contrast, gave rise to a decrease in the proportion of left-handed fibres from 24.9% to 21.4% and an increase in the proportion of right-handed fibres from 25.5% to 26.0%. The modified perfusion and coil setup offers better performance and control over cardiac contraction states. We subsequently performed high-resolution diffusion spectrum imaging (DSI) and 3D whole heart fibre tracking in fixed ex vivo rat hearts in slack state and contracture. As a model-free method, DSI augmented the measurements of water diffusion by also informing on multiple intra-voxel diffusion orientations and non-Gaussian diffusion. This enabled us to identify the transition from right- to left-handed fibres from the subendocardium to the subepicardium, as well as voxels in apical regions that were traversed by multiple fibres. We observed that both the mean generalised fractional anisotropy and mean kurtosis were lower in hearts in contracture compared to the slack state, by 23% and 9.3%, respectively. While its heavy acquisition burden currently limits the application of DSI in vivo, ongoing work in acceleration techniques may enable its use in live animals and patients. This would provide access to the as yet unexplored dimension of non-Gaussian diffusion that could serve as a highly sensitive marker of cardiac micro-structural integrity.
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Affiliation(s)
- Maelene Lohezic
- British Heart Foundation Experimental Magnetic Resonance Unit, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Irvin Teh
- British Heart Foundation Experimental Magnetic Resonance Unit, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Christian Bollensdorff
- National Heart and Lung Institute, Imperial College London, London, UK; Qatar Cardiovascular Research Center, Qatar Foundation, Doha, Qatar
| | - Rémi Peyronnet
- National Heart and Lung Institute, Imperial College London, London, UK
| | - Patrick W Hales
- Imaging and Biophysics Unit, Institute of Child Health, University College London, London, UK
| | - Vicente Grau
- Department of Engineering Science, University of Oxford, Oxford, UK
| | - Peter Kohl
- National Heart and Lung Institute, Imperial College London, London, UK; Department of Computer Science, University of Oxford, Oxford, UK
| | - Jürgen E Schneider
- British Heart Foundation Experimental Magnetic Resonance Unit, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK.
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Naumova AV, Modo M, Moore A, Murry CE, Frank JA. Clinical imaging in regenerative medicine. Nat Biotechnol 2014; 32:804-18. [PMID: 25093889 PMCID: PMC4164232 DOI: 10.1038/nbt.2993] [Citation(s) in RCA: 170] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Accepted: 07/15/2014] [Indexed: 01/09/2023]
Abstract
In regenerative medicine, clinical imaging is indispensable for characterizing damaged tissue and for measuring the safety and efficacy of therapy. However, the ability to track the fate and function of transplanted cells with current technologies is limited. Exogenous contrast labels such as nanoparticles give a strong signal in the short term but are unreliable long term. Genetically encoded labels are good both short- and long-term in animals, but in the human setting they raise regulatory issues related to the safety of genomic integration and potential immunogenicity of reporter proteins. Imaging studies in brain, heart and islets share a common set of challenges, including developing novel labeling approaches to improve detection thresholds and early delineation of toxicity and function. Key areas for future research include addressing safety concerns associated with genetic labels and developing methods to follow cell survival, differentiation and integration with host tissue. Imaging may bridge the gap between cell therapies and health outcomes by elucidating mechanisms of action through longitudinal monitoring.
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Affiliation(s)
- Anna V Naumova
- 1] Department of Radiology, University of Washington, Seattle, Washington, USA. [2] Center for Cardiovascular Biology, University of Washington, Seattle, Washington, USA. [3] Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, Washington, USA
| | - Michel Modo
- 1] McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA. [2] Centre for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, Pennsylvania, USA. [3] Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA. [4] Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Anna Moore
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, Massachusetts, USA
| | - Charles E Murry
- 1] Center for Cardiovascular Biology, University of Washington, Seattle, Washington, USA. [2] Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, Washington, USA. [3] Department of Pathology, University of Washington, Seattle, Washington, USA. [4] Department of Bioengineering, University of Washington, Seattle, Washington, USA. [5] Department of Medicine/Cardiology, University of Washington, Seattle, Washington, USA
| | - Joseph A Frank
- 1] Radiology and Imaging Sciences, Clinical, National Institutes of Health, Bethesda, Maryland, USA. [2] National Institutes of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, Maryland, USA
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Froeling M, Strijkers GJ, Nederveen AJ, Chamuleau SA, Luijten PR. Diffusion Tensor MRI of the Heart – In Vivo Imaging of Myocardial Fiber Architecture. CURRENT CARDIOVASCULAR IMAGING REPORTS 2014. [DOI: 10.1007/s12410-014-9276-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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Sosnovik DE, Mekkaoui C, Huang S, Chen HH, Dai G, Stoeck CT, Ngoy S, Guan J, Wang R, Kostis WJ, Jackowski MP, Wedeen VJ, Kozerke S, Liao R. Microstructural impact of ischemia and bone marrow-derived cell therapy revealed with diffusion tensor magnetic resonance imaging tractography of the heart in vivo. Circulation 2014; 129:1731-41. [PMID: 24619466 PMCID: PMC4034455 DOI: 10.1161/circulationaha.113.005841] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Accepted: 01/31/2014] [Indexed: 12/11/2022]
Abstract
BACKGROUND The arrangement of myofibers in the heart is highly complex and must be replicated by injected cells to produce functional myocardium. A novel approach to characterize the microstructural response of the myocardium to ischemia and cell therapy, with the use of serial diffusion tensor magnetic resonance imaging tractography of the heart in vivo, is presented. METHODS AND RESULTS Validation of the approach was performed in normal (n=6) and infarcted mice (n=6) as well as healthy human volunteers. Mice (n=12) were then injected with bone marrow mononuclear cells 3 weeks after coronary ligation. In half of the mice the donor and recipient strains were identical, and in half the strains were different. A positive response to cell injection was defined by a decrease in mean diffusivity, an increase in fractional anisotropy, and the appearance of new myofiber tracts with the correct orientation. A positive response to bone marrow mononuclear cell injection was seen in 1 mouse. The response of the majority of mice to bone marrow mononuclear cell injection was neutral (9/12) or negative (2/12). The in vivo tractography findings were confirmed with histology. CONCLUSIONS Diffusion tensor magnetic resonance imaging tractography was able to directly resolve the ability of injected cells to generate new myofiber tracts and provided a fundamental readout of their regenerative capacity. A highly novel and translatable approach to assess the efficacy of cell therapy in the heart is thus presented.
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Affiliation(s)
- David E. Sosnovik
- Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston MA
- Cardiovascular Research Center, Cardiology Division, Massachusetts General Hospital, Harvard Medical School, Boston MA
| | - Choukri Mekkaoui
- Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston MA
| | - Shuning Huang
- Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston MA
| | - Howard H. Chen
- Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston MA
- Cardiovascular Research Center, Cardiology Division, Massachusetts General Hospital, Harvard Medical School, Boston MA
| | - Guangping Dai
- Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston MA
| | - Christian T. Stoeck
- Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland
| | - Soeun Ngoy
- Cardiac Muscle Research Laboratory, Divisions of Cardiology and Genetics, Brigham and Woman’s Hospital, Harvard Medical School, Boston MA
| | - Jian Guan
- Cardiac Muscle Research Laboratory, Divisions of Cardiology and Genetics, Brigham and Woman’s Hospital, Harvard Medical School, Boston MA
| | - Ruopeng Wang
- Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston MA
| | - William J. Kostis
- Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston MA
- Cardiovascular Research Center, Cardiology Division, Massachusetts General Hospital, Harvard Medical School, Boston MA
| | - Marcel P. Jackowski
- Department of Computer Science, Institute of Mathematics and Statistics, University of São Paulo, São Paulo, Brazil
| | - Van J. Wedeen
- Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston MA
| | - Sebastian Kozerke
- Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland
| | - Ronglih Liao
- Cardiac Muscle Research Laboratory, Divisions of Cardiology and Genetics, Brigham and Woman’s Hospital, Harvard Medical School, Boston MA
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Jasaityte R, D'hooge J, Herbots L, Daraban AM, Rademakers F, Claus P. Consistent regional heterogeneity of passive diastolic stretch and systolic deformation in the healthy heart: age-related changes in left ventricle contractility. ULTRASOUND IN MEDICINE & BIOLOGY 2014; 40:37-44. [PMID: 24239364 DOI: 10.1016/j.ultrasmedbio.2013.09.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Revised: 08/29/2013] [Accepted: 09/01/2013] [Indexed: 06/02/2023]
Abstract
The consistency of the normal spatial distribution of segmental passive stretch (PreS) and systolic strain (SS) within the left ventricle was investigated and a recently proposed echocardiographic estimate of left ventricular (LV) contractility was used to detect contractility changes with age. Hereto, in 54 healthy subjects, segmental PreS and SS were measured on tissue Doppler images of six left ventricle walls. For each subject, a linear regression line was estimated through the segmental PreS and SS values. The slopes and intercepts of this PreS-SS relationship did not differ between age groups, suggesting no changes in LV contractility with age. Moreover, a consistent regional distribution of PreS was observed, with the highest values measured in the septum, resulting in a similar distribution of SS as a direct consequence of the Frank-Starling mechanism.
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Affiliation(s)
- Ruta Jasaityte
- Division of Cardiovascular Imaging and Dynamics, Department of Cardiovascular Sciences, Catholic University of Leuven, Leuven, Belgium.
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Pennell DJ, Baksi AJ, Carpenter JP, Firmin DN, Kilner PJ, Mohiaddin RH, Prasad SK. Review of Journal of Cardiovascular Magnetic Resonance 2012. J Cardiovasc Magn Reson 2013; 15:76. [PMID: 24006874 PMCID: PMC3847143 DOI: 10.1186/1532-429x-15-76] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Accepted: 08/22/2013] [Indexed: 02/07/2023] Open
Abstract
There were 90 articles published in the Journal of Cardiovascular Magnetic Resonance (JCMR) in 2012, which is an 8% increase in the number of articles since 2011. The quality of the submissions continues to increase. The editors are delighted to report that the 2011 JCMR Impact Factor (which is published in June 2012) has risen to 4.44, up from 3.72 for 2010 (as published in June 2011), a 20% increase. The 2011 impact factor means that the JCMR papers that were published in 2009 and 2010 were cited on average 4.44 times in 2011. The impact factor undergoes natural variation according to citation rates of papers in the 2 years following publication, and is significantly influenced by highly cited papers such as official reports. However, the progress of the journal's impact over the last 5 years has been impressive. Our acceptance rate is approximately 25%, and has been falling as the number of articles being submitted has been increasing. In accordance with Open-Access publishing, the JCMR articles go on-line as they are accepted with no collating of the articles into sections or special thematic issues. For this reason, the Editors have felt that it is useful once per calendar year to summarize the papers for the readership into broad areas of interest or theme, so that areas of interest can be reviewed in a single article in relation to each other and other recent JCMR articles. The papers are presented in broad themes and set in context with related literature and previously published JCMR papers to guide continuity of thought in the journal. We hope that you find the open-access system increases wider reading and citation of your papers, and that you will continue to send your quality manuscripts to JCMR for publication.
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Affiliation(s)
- Dudley J Pennell
- Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, Sydney Street, London, SW3 6NP, UK
- Imperial College, London, UK
| | - A John Baksi
- Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, Sydney Street, London, SW3 6NP, UK
- Imperial College, London, UK
| | - John Paul Carpenter
- Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, Sydney Street, London, SW3 6NP, UK
- Imperial College, London, UK
| | - David N Firmin
- Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, Sydney Street, London, SW3 6NP, UK
- Imperial College, London, UK
| | - Philip J Kilner
- Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, Sydney Street, London, SW3 6NP, UK
- Imperial College, London, UK
| | - Raad H Mohiaddin
- Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, Sydney Street, London, SW3 6NP, UK
- Imperial College, London, UK
| | - Sanjay K Prasad
- Cardiovascular Biomedical Research Unit, Royal Brompton Hospital, Sydney Street, London, SW3 6NP, UK
- Imperial College, London, UK
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57
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Diffusion MRI tractography of the developing human fetal heart. PLoS One 2013; 8:e72795. [PMID: 23991152 PMCID: PMC3753231 DOI: 10.1371/journal.pone.0072795] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2013] [Accepted: 07/15/2013] [Indexed: 11/19/2022] Open
Abstract
Objective Human myocardium has a complex and anisotropic 3D fiber pattern. It remains unknown, however, when in fetal life this anisotropic pattern develops and whether the human heart is structurally fully mature at birth. We aimed here to use diffusion tensor MRI (DTI) tractography to characterize the evolution of fiber architecture in the developing human fetal heart. Methods Human fetal hearts (n = 5) between 10–19 weeks of gestation were studied. The heart from a 6-day old neonate and an adult human heart served as controls. The degree of myocardial anisotropy was measured by calculating the fractional anisotropy (FA) index. In addition, fiber tracts were created by numerically integrating the primary eigenvector field in the heart into coherent streamlines. Results At 10–14 weeks the fetal hearts were highly isotropic and few tracts could be resolved. Between 14–19 weeks the anisotropy seen in the adult heart began to develop. Coherent fiber tracts were well resolved by 19 weeks. The 19-week myocardium, however, remained weakly anisotropic with a low FA and no discernable sheet structure. Conclusions The human fetal heart remains highly isotropic until 14–19 weeks, at which time cardiomyocytes self-align into coherent tracts. This process lags 2–3 months behind the onset of cardiac contraction, which may be a prerequisite for cardiomyocyte maturation and alignment. No evidence of a connective tissue scaffold guiding this process could be identified by DTI. Maturation of the heart’s sheet structure occurs late in gestation and evolves further after birth.
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Carpenter JP, Patel AR, Fernandes JL. Highlights of the 16th annual scientific sessions of the Society for Cardiovascular Magnetic Resonance. J Cardiovasc Magn Reson 2013; 15:60. [PMID: 23870663 PMCID: PMC3726510 DOI: 10.1186/1532-429x-15-60] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2013] [Accepted: 06/13/2013] [Indexed: 12/25/2022] Open
Abstract
The 16th Annual Scientific Sessions of the Society for Cardiovascular Magnetic Resonance (SCMR) took place in San Francisco, USA at the end of January 2013. With a faculty of experts from across the world, this congress provided a wealth of insight into cutting-edge research and technological development. This review article intends to provide a highlight of what represented the most significant advances in the field of cardiovascular magnetic resonance (CMR) during this year's meeting.
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Wang Y, Yao G. Optical tractography of the mouse heart using polarization-sensitive optical coherence tomography. BIOMEDICAL OPTICS EXPRESS 2013; 4:2540-5. [PMID: 24298414 PMCID: PMC3829548 DOI: 10.1364/boe.4.002540] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2013] [Revised: 10/13/2013] [Accepted: 10/15/2013] [Indexed: 05/18/2023]
Abstract
We developed a method to image myocardial fiber architecture in the mouse heart using a Jones matrix-based polarization-sensitive optical coherence tomography (PSOCT) system. The "cross-helical" laminar structure of myocardial fibers can be clearly visualized using this technology. The obtained myocardial fiber organization agrees well with existing knowledge acquired using conventional histology and diffusion tensor magnetic resonance imaging.
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