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Faragli A, Tanacli R, Kolp C, Lapinskas T, Stehning C, Schnackenburg B, Lo Muzio FP, Perna S, Pieske B, Nagel E, Post H, Kelle S, Alogna A. Cardiovascular magnetic resonance feature tracking in pigs: a reproducibility and sample size calculation study. Int J Cardiovasc Imaging 2020; 36:703-712. [PMID: 31950298 PMCID: PMC7125242 DOI: 10.1007/s10554-020-01767-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Accepted: 01/02/2020] [Indexed: 12/18/2022]
Abstract
Cardiovascular magnetic resonance feature tracking (CMR-FT) is a novel technique for non-invasive assessment of myocardial motion and deformation. Although CMR-FT is standardized in humans, literature on comparative analysis from animal models is scarce. In this study, we measured the reproducibility of global strain under various inotropic states and the sample size needed to test its relative changes in pigs. Ten anesthetized healthy Landrace pigs were investigated. After baseline (BL), two further steps were performed: (I) dobutamine-induced hyper-contractility (Dob) and (II) verapamil-induced hypocontractility (Ver). Global longitudinal (GLS), circumferential (GCS) and radial strain (GRS) were assessed. This study shows a good to excellent inter- and intra-observer reproducibility of CMR-FT in pigs under various inotropic states. The highest inter-observer reproducibility was observed for GLS at both BL (ICC 0.88) and Ver (ICC 0.79). According to the sample size calculation for GLS, a small number of animals could be used for future trials.
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Affiliation(s)
- A Faragli
- Department of Internal Medicine and Cardiology, Charité - Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburgerplatz 1, 13353, Berlin, Germany.,Berlin Institute of Health (BIH), Berlin, Germany.,DZHK (German Centre for Cardiovascular Research), partner site, Berlin, Germany
| | - R Tanacli
- Department of Internal Medicine / Cardiology, Deutsches Herzzentrum Berlin, Augustenburger Platz 1, 13353, Berlin, Germany
| | - C Kolp
- Department of Internal Medicine and Cardiology, Charité - Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburgerplatz 1, 13353, Berlin, Germany
| | - T Lapinskas
- Department of Internal Medicine / Cardiology, Deutsches Herzzentrum Berlin, Augustenburger Platz 1, 13353, Berlin, Germany.,Department of Cardiology, Medical Academy, Lithuanian University of Health Sciences, Eiveniu Street 2, 50161, Kaunas, Lithuania
| | - C Stehning
- Clinical Science, Philips Healthcare, Röntgenstr. 24, 22335, Hamburg, Germany
| | - B Schnackenburg
- Clinical Science, Philips Healthcare, Röntgenstr. 24, 22335, Hamburg, Germany
| | - F P Lo Muzio
- Department of Surgery, Dentistry, Paedriatics and Gynaecology, University of Verona, Via S. Francesco 22, 37129, Verona, Italy.,Department of Medicine and Surgery, University of Parma, Via Gramsci 14, 43126, Parma, Italy
| | - S Perna
- Department of Biology, College of Science, University of Bahrain, Sakhir Campus, P.O. Box 32038, Zallaq, Bahrain
| | - B Pieske
- Department of Internal Medicine and Cardiology, Charité - Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburgerplatz 1, 13353, Berlin, Germany.,Berlin Institute of Health (BIH), Berlin, Germany.,DZHK (German Centre for Cardiovascular Research), partner site, Berlin, Germany.,Department of Internal Medicine / Cardiology, Deutsches Herzzentrum Berlin, Augustenburger Platz 1, 13353, Berlin, Germany
| | - E Nagel
- Institute of Experimental and Translational Cardiac Imaging, DZHK Centre for Cardiovascular Imaging, Goethe University Hospital Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany
| | - H Post
- Department of Internal Medicine and Cardiology, Charité - Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburgerplatz 1, 13353, Berlin, Germany.,Berlin Institute of Health (BIH), Berlin, Germany.,DZHK (German Centre for Cardiovascular Research), partner site, Berlin, Germany.,Department of Cardiology, Contilia Heart and Vessel Centre, St. Marien-Hospital Mülheim, Kaiserstraße 50, 45468, Mülheim, Germany
| | - S Kelle
- Department of Internal Medicine and Cardiology, Charité - Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburgerplatz 1, 13353, Berlin, Germany.,Berlin Institute of Health (BIH), Berlin, Germany.,DZHK (German Centre for Cardiovascular Research), partner site, Berlin, Germany
| | - A Alogna
- Department of Internal Medicine and Cardiology, Charité - Universitätsmedizin Berlin, Campus Virchow-Klinikum, Augustenburgerplatz 1, 13353, Berlin, Germany. .,Berlin Institute of Health (BIH), Berlin, Germany. .,DZHK (German Centre for Cardiovascular Research), partner site, Berlin, Germany.
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Karthikeyan B, Sonkawade SD, Pokharel S, Preda M, Schweser F, Zivadinov R, Kim M, Sharma UC. Tagged cine magnetic resonance imaging to quantify regional mechanical changes after acute myocardial infarction. Magn Reson Imaging 2019; 66:208-218. [PMID: 31668928 DOI: 10.1016/j.mri.2019.09.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 08/16/2019] [Accepted: 09/15/2019] [Indexed: 12/29/2022]
Abstract
PURPOSE The conventional volumetric approaches of measuring cardiac function are load-dependent, and are not able to discriminate functional changes in the infarct, transition and remote myocardium. We examined phase-dependent regional mechanical changes in the infarct, transition and remote regions after acute myocardial infarction (MI) in a preclinical mouse model using cardiovascular magnetic resonance imaging (CMR). METHODS We induced acute MI in six mice with left anterior descending coronary artery ligation. We then examined cardiac (infarct, transition and remote-zone) morphology and function utilizing 9.4 T high field CMR before and 2 weeks after the induction of acute MI. Myocardial scar tissue was evaluated by using CMR with late gadolinium enhancement (LGE). After determining global function through volumetric analysis, regional wall motion was evaluated by measuring wall thickening and radial velocities. Strain rate imaging was performed to assess circumferential contraction and relaxation at the myocardium, endocardium, and epicardium. RESULTS There was abnormal LGE in the anterior walls after acute MI suggesting a successful MI procedure. The transition zone consisted of a mixed signal intensity, while the remote zone contained viable myocardium. As expected, the infarct zone had demonstrated severely decreased myocardial velocities and strain rates, suggesting reduced contraction and relaxation function. Compared to pre-infarct baseline, systolic and diastolic velocities (vS and vD) were significantly reduced at the transition zone (vS: -1.86 ± 0.16 cm/s vs -0.68 ± 0.13 cm/s, P < 0.001; vD: 1.86 ± 0.17 cm/s vs 0.53 ± 0.06 cm/s, P < 0.001) and remote zone (vS: -1.86 ± 0.16 cm/s vs -0.65 ± 0.12 cm/s, P < 0.001; vD: 1.86 ± 0.16 cm/s vs 0.51 ± 0.04 cm/s, P < 0.001). Myocardial peak systolic and diastolic strain rates (SRS and SRD) were significantly lower in the transition zone (SRS: -4.2 ± 0.3 s-1 vs -1.3 ± 0.2 s-1, P < 0.001; SRD: 3.9 ± 0.3 s-1 vs 1.3 ± 0.2 s-1, P < 0.001) and remote zone (SRS: -3.8 ± 0.3 s-1 vs -1.4 ± 0.3 s-1, P < 0.001; SRD: 3.5 ± 0.2 s-1 vs 1.5 ± 0.4 s-1, P = 0.006). Endocardial and epicardial SRS and SRD were similarly reduced in the transition and remote zones compared to baseline. CONCLUSIONS This study, for the first time, utilized state-of-the art high-field CMR algorithms in a preclinical mouse model for a comprehensive and controlled evaluation of the regional mechanical changes in the transition and remote zones, after acute MI. Our data demonstrate that CMR can quantitatively monitor dynamic post-MI remodeling in the transition and remote zones, thereby serving as a gold standard tool for therapeutic surveillance.
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Affiliation(s)
- Badri Karthikeyan
- Department of Medicine, Division of Cardiology, Jacob's School of Medicine and Biomedical Sciences, Buffalo, NY, United States of America
| | - Swati D Sonkawade
- Department of Medicine, Division of Cardiology, Jacob's School of Medicine and Biomedical Sciences, Buffalo, NY, United States of America
| | - Saraswati Pokharel
- Department of Pathology and Laboratory Medicine, Roswell Park Comprehensive Cancer Center, Buffalo, NY, United States of America
| | - Marilena Preda
- Center for Biomedical Imaging at the Clinical and Translational Science Institute, University at Buffalo, Buffalo, NY, United States of America
| | - Ferdinand Schweser
- Center for Biomedical Imaging at the Clinical and Translational Science Institute, University at Buffalo, Buffalo, NY, United States of America
| | - Robert Zivadinov
- Center for Biomedical Imaging at the Clinical and Translational Science Institute, University at Buffalo, Buffalo, NY, United States of America
| | - Minhyung Kim
- Department of Surgical Oncology, Roswell Park Comprehensive Cancer Center, Buffalo, NY, United States of America
| | - Umesh C Sharma
- Department of Medicine, Division of Cardiology, Jacob's School of Medicine and Biomedical Sciences, Buffalo, NY, United States of America.
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Lindsey ML, Kassiri Z, Virag JAI, de Castro Brás LE, Scherrer-Crosbie M. Guidelines for measuring cardiac physiology in mice. Am J Physiol Heart Circ Physiol 2018; 314:H733-H752. [PMID: 29351456 PMCID: PMC5966769 DOI: 10.1152/ajpheart.00339.2017] [Citation(s) in RCA: 226] [Impact Index Per Article: 37.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Cardiovascular disease is a leading cause of death, and translational research is needed to understand better mechanisms whereby the left ventricle responds to injury. Mouse models of heart disease have provided valuable insights into mechanisms that occur during cardiac aging and in response to a variety of pathologies. The assessment of cardiovascular physiological responses to injury or insult is an important and necessary component of this research. With increasing consideration for rigor and reproducibility, the goal of this guidelines review is to provide best-practice information regarding how to measure accurately cardiac physiology in animal models. In this article, we define guidelines for the measurement of cardiac physiology in mice, as the most commonly used animal model in cardiovascular research. Listen to this article’s corresponding podcast at http://ajpheart.podbean.com/e/guidelines-for-measuring-cardiac-physiology-in-mice/.
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Affiliation(s)
- Merry L Lindsey
- Department of Physiology and Biophysics, Mississippi Center for Heart Research, University of Mississippi Medical Center , Jackson, Mississippi.,Research Service, G.V. (Sonny) Montgomery Veterans Affairs Medical Center , Jackson, Mississippi
| | - Zamaneh Kassiri
- Department of Physiology, Cardiovascular Research Centre, Mazankowski Alberta Heart Institute, University of Alberta , Edmonton, Alberta , Canada
| | - Jitka A I Virag
- Department of Physiology, Brody School of Medicine, East Carolina University , Greenville, North Carolina
| | - Lisandra E de Castro Brás
- Department of Physiology, Brody School of Medicine, East Carolina University , Greenville, North Carolina
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Cardiovascular magnetic resonance feature tracking in small animals - a preliminary study on reproducibility and sample size calculation. BMC Med Imaging 2017; 17:51. [PMID: 28835220 PMCID: PMC5569535 DOI: 10.1186/s12880-017-0223-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2017] [Accepted: 08/17/2017] [Indexed: 11/10/2022] Open
Abstract
Background Cardiovascular magnetic resonance feature tracking (CMR-FT) is a novel tissue tracking technique developed for noninvasive assessment of myocardial motion and deformation. This preliminary study aimed to evaluate the observer’s reproducibility of CMR-FT in a small animal (mouse) model and define sample size calculation for future trials. Methods Six C57BL/6 J mice were selected from the ongoing experimental mouse model onsite and underwent CMR with a 3 Tesla small animal MRI scanner. Myocardial deformation was analyzed using dedicated software (TomTec, Germany) by two observers. Left ventricular (LV) longitudinal, circumferential and radial strain (EllLAX, EccSAX and ErrSAX) were calculated. To assess intra-observer agreement data analysis was repeated after 4 weeks. The sample size required to detect a relative change in strain was calculated. Results In general, EccSAX and EllLAX demonstrated highest inter-observer reproducibility (ICC 0.79 (0.46–0.91) and 0.73 (0.56–0.83) EccSAX and EllLAX respectively). In contrast, at the intra-observer level EllLAX was more reproducible than EccSAX (ICC 0.83 (0.73–0.90) and 0.74 (0.49–0.87) EllLAX and EccSAX respectively). The reproducibility of ErrSAX was weak at both observer levels. Preliminary sample size calculation showed that a small study sample (e.g. ten animals to detect a relative 10% change in EccSAX) could be sufficient to detect changes if parameter variability is low. Conclusions This pilot study demonstrates good to excellent inter- and intra-observer reproducibility of CMR-FT technique in small animal model. The most reproducible measures are global circumferential and global longitudinal strain, whereas reproducibility of radial strain is weak. Furthermore, sample size calculation demonstrates that a small number of animals could be sufficient for future trials.
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Li Z, Li Y, Zhang L, Zhang X, Sullivan R, Ai X, Szeto C, Cai A, Liu L, Xiao W, Li Q, Ge S, Chen X. Reduced Myocardial Reserve in Young X-Linked Muscular Dystrophy Mice Diagnosed by Two-Dimensional Strain Analysis Combined with Stress Echocardiography. J Am Soc Echocardiogr 2017; 30:815-827.e9. [PMID: 28511858 DOI: 10.1016/j.echo.2017.03.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Indexed: 01/16/2023]
Abstract
BACKGROUND Early, sensitive, and reproducible evaluation of left ventricular function is imperative for the diagnosis of cardiac dysfunction in patients with Duchene muscular dystrophy. The aim of this study was to test the hypothesis that combining two-dimensional strain analysis with catecholamine stress could be a sensitive method for detecting early cardiac dysfunction. METHODS Mdx (C57BL/10ScSn-Dmdmdx/J, a mouse model of DMD) and control (C57BL/10ScSn) mice were studied with conventional M-mode and high-frequency ultrasound-based two-dimensional speckle-tracking echocardiography using long- and short-axis images of the left ventricle at baseline and after intraperitoneal isoprenaline (ISO) administration (2 μg/g body weight). RESULTS Conventional M-mode analysis showed no differences in left ventricular fractional shortening, wall thickness, or internal diameter at diastole between mdx and control mice before the age of 6 months. ISO increased left ventricular ejection fraction and fractional shortening to the same extent in mdx and control mice at young ages (3, 4, and 5 months). No differences in basal peak systolic strain (PSS) but increased SDs of times to PSS between young mdx and control mice were found. After ISO, PSS and percentile changes of PSS were significantly diminished in mdx mice compared with control mice at young ages. ISO increased the normalized maximum difference of times to PSS in young mdx mice but not in young control mice, suggesting that ISO reduces cardiac contractile synchrony in young mdx mice. CONCLUSIONS This study suggests that catecholamine stress coupled with two-dimensional strain analysis is a feasible and sensitive approach for detecting early onset of cardiac dysfunction, which is instrumental for early diagnosis of cardiac dysfunction and early treatment.
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Affiliation(s)
- Zhenzhou Li
- Department of Ultrasound, The Second People's Hospital of Shenzhen, Shenzhen, China; Drexel University College of Medicine, Philadelphia, Pennsylvania; Department of Physiology and Cardiovascular Research Center, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania
| | - Ying Li
- Department of Physiology and Cardiovascular Research Center, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania; The General Hospital of The PLA Rocket Force, Beijing, China
| | - Li Zhang
- Drexel University College of Medicine, Philadelphia, Pennsylvania; Department of Physiology and Cardiovascular Research Center, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania; Department of Ultrasound, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xiaoying Zhang
- Department of Physiology and Cardiovascular Research Center, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania
| | - Rebecca Sullivan
- Department of Physiology and Cardiovascular Research Center, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania
| | - Xiaojie Ai
- Department of Physiology and Cardiovascular Research Center, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania; College of Biological Sciences, Shanghai Jiaotong University, Shanghai, China
| | - Christopher Szeto
- Department of Physiology and Cardiovascular Research Center, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania
| | - Angela Cai
- Department of Physiology and Cardiovascular Research Center, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania
| | - Longjian Liu
- Drexel University College of Medicine, Philadelphia, Pennsylvania
| | - Weidong Xiao
- Department of Microbiology and Immunology and Sol Sherry Thrombosis Center, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania
| | - Quanshui Li
- Department of Ultrasound, The Second People's Hospital of Shenzhen, Shenzhen, China
| | - Shuping Ge
- Drexel University College of Medicine, Philadelphia, Pennsylvania
| | - Xiongwen Chen
- Department of Physiology and Cardiovascular Research Center, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania.
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Carruth ED, McCulloch AD, Omens JH. Transmural gradients of myocardial structure and mechanics: Implications for fiber stress and strain in pressure overload. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2016; 122:215-226. [PMID: 27845176 DOI: 10.1016/j.pbiomolbio.2016.11.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Although a truly complete understanding of whole heart activation, contraction, and deformation is well beyond our current reach, a significant amount of effort has been devoted to discovering and understanding the mechanisms by which myocardial structure determines cardiac function to better treat patients with cardiac disease. Several experimental studies have shown that transmural fiber strain is relatively uniform in both diastole and systole, in contrast to predictions from traditional mechanical theory. Similarly, mathematical models have largely predicted uniform fiber stress across the wall. The development of this uniform pattern of fiber stress and strain during filling and ejection is due to heterogeneous transmural distributions of several myocardial structures. This review summarizes these transmural gradients, their contributions to fiber mechanics, and the potential functional effects of their remodeling during pressure overload hypertrophy.
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Affiliation(s)
- Eric D Carruth
- Department of Bioengineering, University of California San Diego, La Jolla, CA, USA.
| | - Andrew D McCulloch
- Department of Bioengineering, University of California San Diego, La Jolla, CA, USA.
| | - Jeffrey H Omens
- Department of Bioengineering, University of California San Diego, La Jolla, CA, USA; Department of Medicine, University of California San Diego, La Jolla, CA, USA.
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Abstract
The heart pumps blood to maintain circulation and ensure the delivery of oxygenated blood to all the organs of the body. Mechanics play a critical role in governing and regulating heart function under both normal and pathological conditions. Biological processes and mechanical stress are coupled together in regulating myocyte function and extracellular matrix structure thus controlling heart function. Here, we offer a brief introduction to the biomechanics of left ventricular function and then summarize recent progress in the study of the effects of mechanical stress on ventricular wall remodeling and cardiac function as well as the effects of wall mechanical properties on cardiac function in normal and dysfunctional hearts. Various mechanical models to determine wall stress and cardiac function in normal and diseased hearts with both systolic and diastolic dysfunction are discussed. The results of these studies have enhanced our understanding of the biomechanical mechanism in the development and remodeling of normal and dysfunctional hearts. Biomechanics provide a tool to understand the mechanism of left ventricular remodeling in diastolic and systolic dysfunction and guidance in designing and developing new treatments.
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Affiliation(s)
- Andrew P. Voorhees
- Department of Mechanical Engineering, The University of Texas at San Antonio, Biomedical Engineering Program, UTSA-UTHSCSA
| | - Hai-Chao Han
- Department of Mechanical Engineering, The University of Texas at San Antonio, Biomedical Engineering Program, UTSA-UTHSCSA
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Wang X, Chen T, Zhang S, Schaerer J, Qian Z, Huh S, Metaxas D, Axel L. Meshless deformable models for 3D cardiac motion and strain analysis from tagged MRI. Magn Reson Imaging 2015; 33:146-60. [PMID: 25157446 PMCID: PMC4876045 DOI: 10.1016/j.mri.2014.08.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Revised: 05/28/2014] [Accepted: 08/08/2014] [Indexed: 12/12/2022]
Abstract
Tagged magnetic resonance imaging (TMRI) provides a direct and noninvasive way to visualize the in-wall deformation of the myocardium. Due to the through-plane motion, the tracking of 3D trajectories of the material points and the computation of 3D strain field call for the necessity of building 3D cardiac deformable models. The intersections of three stacks of orthogonal tagging planes are material points in the myocardium. With these intersections as control points, 3D motion can be reconstructed with a novel meshless deformable model (MDM). Volumetric MDMs describe an object as point cloud inside the object boundary and the coordinate of each point can be written in parametric functions. A generic heart mesh is registered on the TMRI with polar decomposition. A 3D MDM is generated and deformed with MR image tagging lines. Volumetric MDMs are deformed by calculating the dynamics function and minimizing the local Laplacian coordinates. The similarity transformation of each point is computed by assuming its neighboring points are making the same transformation. The deformation is computed iteratively until the control points match the target positions in the consecutive image frame. The 3D strain field is computed from the 3D displacement field with moving least squares. We demonstrate that MDMs outperformed the finite element method and the spline method with a numerical phantom. Meshless deformable models can track the trajectory of any material point in the myocardium and compute the 3D strain field of any particular area. The experimental results on in vivo healthy and patient heart MRI show that the MDM can fully recover the myocardium motion in three dimensions.
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Affiliation(s)
- Xiaoxu Wang
- Shenzhen Institute of Advance Technology, CAS, Xueyuan Ave. 1068, Xili, Nanshan, Shenzhen, Guangdong, China, 518055.
| | - Ting Chen
- Radiology Department, New York University, 660 first Avenue, New York, NY, 10016, USA
| | - Shaoting Zhang
- Department of Computer Science, Rutgers University, 110 Frelinghuysen Rd, Piscataway, NJ, 08854, USA
| | - Joël Schaerer
- CREATIS, INSA LYON, Bâtiment Blaise Pascal, 7 Avenue Jean Capelle, 69621, Villeurbanne Cedex, France
| | - Zhen Qian
- Department of Computer Science, Rutgers University, 110 Frelinghuysen Rd, Piscataway, NJ, 08854, USA
| | - Suejung Huh
- Department of Computer Science, Rutgers University, 110 Frelinghuysen Rd, Piscataway, NJ, 08854, USA
| | - Dimitris Metaxas
- Department of Computer Science, Rutgers University, 110 Frelinghuysen Rd, Piscataway, NJ, 08854, USA
| | - Leon Axel
- Radiology Department, New York University, 660 first Avenue, New York, NY, 10016, USA
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Jiang K, Yu X. Quantification of regional myocardial wall motion by cardiovascular magnetic resonance. Quant Imaging Med Surg 2014; 4:345-57. [PMID: 25392821 DOI: 10.3978/j.issn.2223-4292.2014.09.01] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2014] [Accepted: 09/12/2014] [Indexed: 12/12/2022]
Abstract
Cardiovascular magnetic resonance (CMR) is a versatile tool that also allows comprehensive and accurate measurement of both global and regional myocardial contraction. Quantification of regional wall motion parameters, such as strain, strain rate, twist and torsion, has been shown to be more sensitive to early-stage functional alterations. Since the invention of CMR tagging by magnetization saturation in 1988, several CMR techniques have been developed to enable the measurement of regional myocardial wall motion, including myocardial tissue tagging, phase contrast mapping, displacement encoding with stimulated echoes (DENSE), and strain encoded (SENC) imaging. These techniques have been developed with their own advantages and limitations. In this review, two widely used and closely related CMR techniques, i.e., tissue tagging and DENSE, will be discussed from the perspective of pulse sequence development and image-processing techniques. The clinical and preclinical applications of tissue tagging and DENSE in assessing wall motion mechanics in both normal and diseased hearts, including coronary artery diseases, hypertrophic cardiomyopathy, aortic stenosis, and Duchenne muscular dystrophies, will be discussed.
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Affiliation(s)
- Kai Jiang
- 1 Departments of Biomedical Engineering, 2 Case Center for Imaging Research, 3 Radiology, and 4 Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio, USA
| | - Xin Yu
- 1 Departments of Biomedical Engineering, 2 Case Center for Imaging Research, 3 Radiology, and 4 Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio, USA
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Yu Y, Zhang S, Li K, Metaxas D, Axel L. Deformable models with sparsity constraints for cardiac motion analysis. Med Image Anal 2014; 18:927-37. [PMID: 24721617 PMCID: PMC4876050 DOI: 10.1016/j.media.2014.03.002] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Revised: 03/08/2014] [Accepted: 03/11/2014] [Indexed: 11/18/2022]
Abstract
Deformable models integrate bottom-up information derived from image appearance cues and top-down priori knowledge of the shape. They have been widely used with success in medical image analysis. One limitation of traditional deformable models is that the information extracted from the image data may contain gross errors, which adversely affect the deformation accuracy. To alleviate this issue, we introduce a new family of deformable models that are inspired from the compressed sensing, a technique for accurate signal reconstruction by harnessing some sparseness priors. In this paper, we employ sparsity constraints to handle the outliers or gross errors, and integrate them seamlessly with deformable models. The proposed new formulation is applied to the analysis of cardiac motion using tagged magnetic resonance imaging (tMRI), where the automated tagging line tracking results are very noisy due to the poor image quality. Our new deformable models track the heart motion robustly, and the resulting strains are consistent with those calculated from manual labels.
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Affiliation(s)
- Yang Yu
- Department of Computer Science, Rutgers University, Piscataway, NJ, USA
| | - Shaoting Zhang
- Department of Computer Science, University of North Carolina at Charlotte, NC, USA.
| | - Kang Li
- Department of Industrial and Systems Engineering, Rutgers University, Piscataway, NJ, USA
| | - Dimitris Metaxas
- Department of Computer Science, Rutgers University, Piscataway, NJ, USA
| | - Leon Axel
- Radiology Department, New York University, New York, NY, USA
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Meßner NM, Zöllner FG, Kalayciyan R, Schad LR. Pre-clinical functional Magnetic Resonance Imaging Part II: The heart. Z Med Phys 2014; 24:307-22. [PMID: 25023418 DOI: 10.1016/j.zemedi.2014.06.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Revised: 05/09/2014] [Accepted: 06/17/2014] [Indexed: 12/21/2022]
Abstract
One third of all deaths worldwide in 2008 were caused by cardiovascular diseases (CVD), and the incidence of CVD related deaths rises ever more. Thus, improved imaging techniques and modalities are needed for the evaluation of cardiac morphology and function. Cardiac magnetic resonance imaging (CMRI) is a minimally invasive technique that is increasingly important due to its high spatial and temporal resolution, its high soft tissue contrast and its ability of functional and quantitative imaging. It is widely accepted as the gold standard of cardiac functional analysis. In the short period of small animal MRI, remarkable progress has been achieved concerning new, fast imaging schemes as well as purpose-built equipment. Dedicated small animal scanners allow for tapping the full potential of recently developed animal models of cardiac disease. In this paper, we review state-of-the-art cardiac magnetic resonance imaging techniques and applications in small animals at ultra-high fields (UHF).
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Affiliation(s)
- Nadja M Meßner
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Frank G Zöllner
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.
| | - Raffi Kalayciyan
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Lothar R Schad
- Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
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Abstract
Deformable models have been widely used with success in medical image analysis. They combine bottom-up information derived from image appearance cues, with top-down shape-based constraints within a physics-based formulation. However, in many real world problems the observations extracted from the image data often contain gross errors, which adversely affect the deformation accuracy. To alleviate this issue, we introduce a new family of deformable models that are inspired from compressed sensing, a technique for efficiently reconstructing a signal based on its sparseness in some domain. In this problem, we employ sparsity to represent the outliers or gross errors, and combine it seamlessly with deformable models. The proposed new formulation is applied to the analysis of cardiac motion, using tagged magnetic resonance imaging (tMRI), where the automated tagging line tracking results are very noisy due to the poor image quality. Our new deformable models track the heart motion robustly, and the resulting strains are consistent with those calculated from manual labels.
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Chen Y, Ye L, Zhong J, Li X, Yan C, Chandler MP, Calvin S, Xiao F, Negia M, Low WC, Zhang J, Yu X. The Structural Basis of Functional Improvement in Response to Human Umbilical Cord Blood Stem Cell Transplantation in Hearts With Postinfarct LV Remodeling. Cell Transplant 2013; 24:971-83. [PMID: 24332083 DOI: 10.3727/096368913x675746] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Cellular therapy for myocardial repair has been one of the most intensely investigated interventional strategies for acute myocardial infarction. Although the therapeutic potential of stem cells has been demonstrated in various studies, the underlying mechanisms for such improvements are poorly understood. In the present study, we investigated the long-term effects of stem cell therapy on both myocardial fiber organization and regional contractile function using a rat model of postinfarct remodeling. Human nonhematopoietic umbilical cord blood stem cells (nh-UCBSCs) were administered via tail vein to rats 2 days after infarct surgery. Animals were maintained without immunosuppressive therapy. In vivo and ex vivo MR imaging was performed on infarct hearts 10 months after cell transplantation. Compared to the age-matched rats exposed to the identical surgery, both global and regional cardiac functions of the nh-UCBSC-treated hearts, such as ejection fraction, ventricular strain, and torsion, were significantly improved. More importantly, the treated hearts exhibited preserved fiber orientation and water diffusivities that were similar to those in sham-operated control hearts. These data provide the first evidence that nh-UCBSC treatment may prevent/delay untoward structural remodeling in postinfarct hearts, which supports the improved LV function observed in vivo in the absence of immunosuppression, suggesting a beneficial paracrine effect occurred with the cellular therapy.
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Affiliation(s)
- Yong Chen
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA
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14
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Tangney J, Chuang J, Janssen M, Krishnamurthy A, Liao P, Hoshijima M, Wu X, Meininger G, Muthuchamy M, Zemljic-Harpf A, Ross R, Frank L, McCulloch A, Omens J. Novel role for vinculin in ventricular myocyte mechanics and dysfunction. Biophys J 2013; 104:1623-33. [PMID: 23561539 PMCID: PMC3617425 DOI: 10.1016/j.bpj.2013.02.021] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2012] [Revised: 01/07/2013] [Accepted: 02/07/2013] [Indexed: 01/23/2023] Open
Abstract
Vinculin (Vcl) plays a key structural role in ventricular myocytes that, when disrupted, can lead to contractile dysfunction and dilated cardiomyopathy. To investigate the role of Vcl in myocyte and myocardial function, cardiomyocyte-specific Vcl knockout mice (cVclKO) and littermate control wild-type mice were studied with transmission electron microscopy (TEM) and in vivo magnetic resonance imaging (MRI) tagging before the onset of global ventricular dysfunction. MRI revealed significantly decreased systolic strains transverse to the myofiber axis in vivo, but no changes along the muscle fibers or in fiber tension in papillary muscles from heterozygous global Vcl null mice. Myofilament lattice spacing from TEM was significantly greater in cVclKO versus wild-type hearts fixed in the unloaded state. AFM in Vcl heterozygous null mouse myocytes showed a significant decrease in membrane cortical stiffness. A multiscale computational model of ventricular mechanics incorporating cross-bridge geometry and lattice mechanics showed that increased transverse systolic stiffness due to increased lattice spacing may explain the systolic wall strains associated with Vcl deficiency, before the onset of ventricular dysfunction. Loss of cardiac myocyte Vcl may decrease systolic transverse strains in vivo by decreasing membrane cortical tension, which decreases transverse compression of the lattice thereby increasing interfilament spacing and stress transverse to the myofibers.
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Affiliation(s)
- Jared R. Tangney
- Department of Bioengineering, University of California-San Diego, La Jolla, California
| | - Joyce S. Chuang
- Department of Bioengineering, University of California-San Diego, La Jolla, California
| | - Matthew S. Janssen
- Department of Bioengineering, University of California-San Diego, La Jolla, California
| | - Adarsh Krishnamurthy
- Department of Bioengineering, University of California-San Diego, La Jolla, California
| | - Peter Liao
- Department of Medicine, University of California-San Diego, La Jolla, California
- Veterans Administration Healthcare San Diego, San Diego, California
| | - Masahiko Hoshijima
- Department of Medicine, University of California-San Diego, La Jolla, California
- Cardiac Biomedical Science and Engineering Center, University of California-San Diego, La Jolla, California
| | - Xin Wu
- Department of Systems Biology and Translational Medicine, Texas A&M Health Science Center, College of Medicine, College Station, Texas
| | - Gerald A. Meininger
- Dalton Cardiovascular Research Center and Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri
| | - Mariappan Muthuchamy
- Department of Systems Biology and Translational Medicine, Texas A&M Health Science Center, College of Medicine, College Station, Texas
| | - Alice Zemljic-Harpf
- Department of Medicine, University of California-San Diego, La Jolla, California
- Veterans Administration Healthcare San Diego, San Diego, California
| | - Robert S. Ross
- Department of Medicine, University of California-San Diego, La Jolla, California
- Veterans Administration Healthcare San Diego, San Diego, California
- Cardiac Biomedical Science and Engineering Center, University of California-San Diego, La Jolla, California
| | - Lawrence R. Frank
- Department of Radiology, University of California-San Diego, La Jolla, California
| | - Andrew D. McCulloch
- Department of Bioengineering, University of California-San Diego, La Jolla, California
- Department of Medicine, University of California-San Diego, La Jolla, California
- Cardiac Biomedical Science and Engineering Center, University of California-San Diego, La Jolla, California
| | - Jeffrey H. Omens
- Department of Bioengineering, University of California-San Diego, La Jolla, California
- Department of Medicine, University of California-San Diego, La Jolla, California
- Cardiac Biomedical Science and Engineering Center, University of California-San Diego, La Jolla, California
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15
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Velocity Vector Imaging Fails to Quantify Regional Myocardial Dysfunction in a Mouse Model of Isoprenaline-Induced Cardiotoxicity. Echocardiography 2012; 29:818-26. [DOI: 10.1111/j.1540-8175.2012.01705.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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16
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Zhong X, Gibberman LB, Spottiswoode BS, Gilliam AD, Meyer CH, French BA, Epstein FH. Comprehensive cardiovascular magnetic resonance of myocardial mechanics in mice using three-dimensional cine DENSE. J Cardiovasc Magn Reson 2011; 13:83. [PMID: 22208954 PMCID: PMC3278394 DOI: 10.1186/1532-429x-13-83] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2011] [Accepted: 12/30/2011] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Quantitative noninvasive imaging of myocardial mechanics in mice enables studies of the roles of individual genes in cardiac function. We sought to develop comprehensive three-dimensional methods for imaging myocardial mechanics in mice. METHODS A 3D cine DENSE pulse sequence was implemented on a 7T small-bore scanner. The sequence used three-point phase cycling for artifact suppression and a stack-of-spirals k-space trajectory for efficient data acquisition. A semi-automatic 2D method was adapted for 3D image segmentation, and automated 3D methods to calculate strain, twist, and torsion were employed. A scan protocol that covered the majority of the left ventricle in a scan time of less than 25 minutes was developed, and seven healthy C57Bl/6 mice were studied. RESULTS Using these methods, multiphase normal and shear strains were measured, as were myocardial twist and torsion. Peak end-systolic values for the normal strains at the mid-ventricular level were 0.29 ± 0.17, -0.13 ± 0.03, and -0.18 ± 0.14 for E(rr), E(cc), and E(ll), respectively. Peak end-systolic values for the shear strains were 0.00 ± 0.08, 0.04 ± 0.12, and 0.03 ± 0.07 for E(rc), E(rl), and E(cl), respectively. The peak end-systolic normalized torsion was 5.6 ± 0.9°. CONCLUSIONS Using a 3D cine DENSE sequence tailored for cardiac imaging in mice at 7 T, a comprehensive assessment of 3D myocardial mechanics can be achieved with a scan time of less than 25 minutes and an image analysis time of approximately 1 hour.
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Affiliation(s)
| | | | - Bruce S Spottiswoode
- MRC/UCT Medical Imaging Research Unit, University of Cape Town, Cape Town, South Africa
| | | | - Craig H Meyer
- Radiology Department, University of Virginia, Charlottesville, USA
- Biomedical Engineering Department, University of Virginia, Charlottesville, USA
| | - Brent A French
- Biomedical Engineering Department, University of Virginia, Charlottesville, USA
| | - Frederick H Epstein
- Radiology Department, University of Virginia, Charlottesville, USA
- Biomedical Engineering Department, University of Virginia, Charlottesville, USA
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17
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Desjardins CL, Chen Y, Coulton AT, Hoit BD, Yu X, Stelzer JE. Cardiac myosin binding protein C insufficiency leads to early onset of mechanical dysfunction. Circ Cardiovasc Imaging 2011; 5:127-36. [PMID: 22157650 DOI: 10.1161/circimaging.111.965772] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
BACKGROUND Decreased expression of cardiac myosin binding protein C (cMyBPC) as a result of genetic mutations may contribute to the development of hypertrophic cardiomyopathy (HCM); however, the mechanisms that link cMyBPC expression and HCM development, especially contractile dysfunction, remain unclear. METHODS AND RESULTS We evaluated cardiac mechanical function in vitro and in vivo in young mice (8-10 weeks of age) carrying no functional cMyBPC alleles (cMyBPC(-/-)) or 1 functional cMyBPC allele (cMyBPC(±)). Skinned myocardium isolated from cMyBPC(-/-) hearts displayed significant accelerations in stretch activation cross-bridge kinetics. Cardiac MRI studies revealed severely depressed in vivo left ventricular (LV) magnitude and rates of LV wall strain and torsion compared with wild-type (WT) mice. Heterozygous cMyBPC(±) hearts expressed 23±5% less cMyBPC than WT hearts but did not display overt hypertrophy. Skinned myocardium isolated from cMyBPC(±) hearts displayed small accelerations in the rate of stretch induced cross-bridge recruitment. MRI measurements revealed reductions in LV torsion and circumferential strain, as well reduced circumferential strain rates in early systole and diastole. CONCLUSIONS Modest decreases in cMyBPC expression in the mouse heart result in early-onset subtle changes in cross-bridge kinetics and in vivo LV mechanical function, which could contribute to the development of HCM later in life.
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Affiliation(s)
- Candida L Desjardins
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, OH 44106, USA
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18
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Chuang JS, Zemljic-Harpf A, Ross RS, Frank LR, McCulloch AD, Omens JH. Determination of three-dimensional ventricular strain distributions in gene-targeted mice using tagged MRI. Magn Reson Med 2011; 64:1281-8. [PMID: 20981782 DOI: 10.1002/mrm.22547] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
A model-based method for calculating three-dimensional (3D) cardiac wall strain distributions in the mouse has been developed and tested in a genetically engineered mouse model of dilated cardiomyopathy. Data from MR tagging and harmonic phase (HARP) tracking were used to measure material point displacements, and 3D Lagrangian strains were calculated throughout the entire left ventricle (LV) with a deformable parametric model. A mouse model where cardiomyocytes are specifically made deficient in vinculin (VclKO) were compared to wild-type (WT) littermates. 3D strain analysis revealed differences in LV wall mechanics between WT and VclKO mice at 8 weeks of age when systolic function had just begun to decline. Most notably, end-systolic radial strain and torsional shear were reduced in VclKO hearts which contributed to regional mechanical dysfunction. This study demonstrates the feasibility of using MRI tagging methods to detect alterations in 3D myocardial strain distributions in genetically engineered mouse models of cardiovascular disease.
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Affiliation(s)
- Joyce S Chuang
- Department of Bioengineering, University of California-San Diego, La Jolla, California, USA
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19
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Li W, Yu X. Quantification of myocardial strain at early systole in mouse heart: restoration of undeformed tagging grid with single-point HARP. J Magn Reson Imaging 2011; 32:608-14. [PMID: 20815058 DOI: 10.1002/jmri.22256] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
PURPOSE To develop accurate strain and torsion quantification method for the assessment of myocardial contraction in mice by MRI tagging. MATERIALS AND METHODS Ventricular wall motion at baseline and during beta-adrenergic stimulation was assessed in mice using MRI tagging. Myocardial strain and torsion were quantified using finite element analysis method. A harmonic phase (HARP) based method was developed for the restoration of undeformed taglines for more accurate calculation of myocardial wall strain and torsion. RESULTS Myocardial deformation was observed at early systole (<20 msec after QRS) both at baseline and during beta-adrenergic stimulation. The HARP-based method allowed robust restoration of undeformed taglines that can be used as the reference in finite element analysis of the tagged images. Without such correction for myocardial deformation in the reference image, inaccuracy in strain quantification underestimated significant strain development at early systole in dobutamine-stimulated hearts. CONCLUSION The HARP-based method developed in the current study enabled automated restoration of undeformed taglines in mouse hearts, leading to more accurate calculation of myocardial wall strain and torsion during dobutamine stimulation.
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Affiliation(s)
- Wei Li
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio 44122, USA
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20
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Zhong J, Yu X. Strain and torsion quantification in mouse hearts under dobutamine stimulation using 2D multiphase MR DENSE. Magn Reson Med 2010; 64:1315-22. [PMID: 20740659 DOI: 10.1002/mrm.22530] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2009] [Revised: 05/13/2010] [Accepted: 05/17/2010] [Indexed: 11/08/2022]
Abstract
In this study, a 2D multiphase magnetic resonance displacement encoding with stimulated echoes (DENSE) imaging and analysis method was developed for direct quantification of Lagrangian strain in the mouse heart. Using the proposed method, <10 ms temporal resolution and 0.56 mm in-plane resolution were achieved. A validation study that compared strain calculation by displacement encoding with stimulated echoes and by magnetic resonance tagging showed high correlation between the two methods (R(2) > 0.80). Regional ventricular wall strain and twist were characterized in mouse hearts at baseline and under dobutamine stimulation. Dobutamine stimulation induced significant increase in radial and circumferential strains and torsion at peak systole. A rapid untwisting was also observed during early diastole. This work demonstrates the capability of characterizing cardiac functional response to dobutamine stimulation in the mouse heart using 2D multiphase magnetic resonance displacement encoding with stimulated echoes.
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Affiliation(s)
- Jia Zhong
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA
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21
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Chen Y, Somji A, Yu X, Stelzer JE. Altered in vivo left ventricular torsion and principal strains in hypothyroid rats. Am J Physiol Heart Circ Physiol 2010; 299:H1577-87. [PMID: 20729398 DOI: 10.1152/ajpheart.00406.2010] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The twisting and untwisting motions of the left ventricle (LV) lead to efficient ejection of blood during systole and filling of the ventricle during diastole. Global LV mechanical performance is dependent on the contractile properties of cardiac myocytes; however, it is not known how changes in contractile protein expression affect the pattern and timing of LV rotation. At the myofilament level, contractile performance is largely dependent on the isoforms of myosin heavy chain (MHC) that are expressed. Therefore, in this study, we used MRI to examine the in vivo mechanical consequences of altered MHC isoform expression by comparing the contractile properties of hypothyroid rats, which expressed only the slow β-MHC isoform, and euthyroid rats, which predominantly expressed the fast α-MHC isoform. Unloaded shortening velocity (V(o)) and apparent rate constants of force development (k(tr)) were measured in the skinned ventricular myocardium isolated from euthyroid and hypothyroid hearts. Increased expression of β-MHC reduced LV torsion and fiber strain and delayed the development of peak torsion and strain during systole. Depressed in vivo mechanical performance in hypothyroid rats was related to slowed cross-bridge performance, as indicated by significantly slower V(o) and k(tr), compared with euthyroid rats. Dobutamine infusion in hypothyroid hearts produced smaller increases in torsion and strain and aberrant transmural torsion patterns, suggesting that the myocardial response to β-adrenergic stress is compromised. Thus, increased expression of β-MHC alters the pattern and decreases the magnitude of LV rotation, contributing to reduced mechanical performance during systole, especially in conditions of increased workload.
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Affiliation(s)
- Yong Chen
- Department of Biomedical Engineering, School of Engineering, Case Western Reserve University, Cleveland, Ohio 44106, USA
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22
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Li W, Liu W, Zhong J, Yu X. Early manifestation of alteration in cardiac function in dystrophin deficient mdx mouse using 3D CMR tagging. J Cardiovasc Magn Reson 2009; 11:40. [PMID: 19849858 PMCID: PMC2774673 DOI: 10.1186/1532-429x-11-40] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2009] [Accepted: 10/22/2009] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Duchenne muscular dystrophy (DMD) is caused by the absence of the cytoskeletal protein, dystrophin. In DMD patients, dilated cardiomyopathy leading to heart failure may occur during adolescence. However, early cardiac dysfunction is frequently undetected due to physical inactivity and generalized debilitation. The objective of this study is to determine the time course of cardiac functional alterations in mdx mouse, a mouse model of DMD, by evaluating regional ventricular function with CMR tagging. METHODS In vivo myocardial function was evaluated by 3D CMR tagging in mdx mice at early (2 months), middle (7 months) and late (10 months) stages of disease development. Global cardiac function, regional myocardial wall strains, and ventricular torsion were quantified. Myocardial lesions were assessed with Masson's trichrome staining. RESULTS Global contractile indexes were similar between mdx and C57BL/6 mice in each age group. Histology analysis showed that young mdx mice were free of myocardial lesions. Interstitial fibrosis was present in 7 month mdx mice, with further development into patches or transmural lesions at 10 months of age. As a result, 10 month mdx mice showed significantly reduced regional strain and torsion. However, young mdx mice showed an unexpected increase in regional strain and torsion, while 7 month mdx mice displayed similar regional ventricular function as the controls. CONCLUSION Despite normal global ventricular function, CMR tagging detected a biphasic change in myocardial wall strain and torsion, with an initial increase at young age followed by progressive decrease at older ages. These results suggest that CMR tagging can provide more sensitive measures of functional alterations than global functional indexes in dystrophin-related cardiomyopathies.
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MESH Headings
- Age Factors
- Aging
- Animals
- Cardiac Output
- Cardiomyopathy, Dilated/etiology
- Cardiomyopathy, Dilated/pathology
- Cardiomyopathy, Dilated/physiopathology
- Disease Models, Animal
- Disease Progression
- Fibrosis
- Image Interpretation, Computer-Assisted
- Imaging, Three-Dimensional
- Magnetic Resonance Imaging, Cine
- Mice
- Mice, Inbred C57BL
- Mice, Inbred mdx
- Muscular Dystrophy, Duchenne/complications
- Muscular Dystrophy, Duchenne/pathology
- Muscular Dystrophy, Duchenne/physiopathology
- Myocardial Contraction
- Myocardium/pathology
- Stroke Volume
- Time Factors
- Torsion, Mechanical
- Ventricular Function, Left
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Affiliation(s)
- Wei Li
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA
- Case Center for Imaging Research, Case Western Reserve University, Cleveland, Ohio, USA
| | - Wei Liu
- Department of Biomedical Engineering, Washington University, St Louis, Missouri, USA
| | - Jia Zhong
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA
- Case Center for Imaging Research, Case Western Reserve University, Cleveland, Ohio, USA
| | - Xin Yu
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA
- Department of Radiology, Case Western Reserve University, Cleveland, Ohio, USA
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio, USA
- Case Center for Imaging Research, Case Western Reserve University, Cleveland, Ohio, USA
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