1
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Wang VY, Tartibi M, Zhang Y, Selvaganesan K, Haraldsson H, Auger DA, Faraji F, Spaulding K, Takaba K, Collins A, Aguayo E, Saloner D, Wallace AW, Weinsaft JW, Epstein FH, Guccione J, Ge L, Ratcliffe MB. A kinematic model-based analysis framework for 3D Cine-DENSE-validation with an axially compressed gel phantom and application in sheep before and after antero-apical myocardial infarction. Magn Reson Med 2021; 86:2105-2121. [PMID: 34096083 DOI: 10.1002/mrm.28775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 02/24/2021] [Accepted: 02/25/2021] [Indexed: 11/06/2022]
Abstract
PURPOSE Myocardial strain is increasingly used to assess left ventricular (LV) function. Incorporation of LV deformation into finite element (FE) modeling environment with subsequent strain calculation will allow analysis to reach its full potential. We describe a new kinematic model-based analysis framework (KMAF) to calculate strain from 3D cine-DENSE (displacement encoding with stimulated echoes) MRI. METHODS Cine-DENSE allows measurement of 3D myocardial displacement with high spatial accuracy. The KMAF framework uses cine cardiovascular magnetic resonance (CMR) to facilitate cine-DENSE segmentation, interpolates cine-DENSE displacement, and kinematically deforms an FE model to calculate strain. This framework was validated in an axially compressed gel phantom and applied in 10 healthy sheep and 5 sheep after myocardial infarction (MI). RESULTS Excellent Bland-Altman agreement of peak circumferential (Ecc ) and longitudinal (Ell ) strain (mean difference = 0.021 ± 0.04 and -0.006 ± 0.03, respectively), was found between KMAF estimates and idealized FE simulation. Err had a mean difference of -0.014 but larger variation (±0.12). Cine-DENSE estimated end-systolic (ES) Ecc , Ell and Err exhibited significant spatial variation for healthy sheep. Displacement magnitude was reduced on average by 27%, 42%, and 56% after MI in the remote, adjacent and MI regions, respectively. CONCLUSIONS The KMAF framework allows accurate calculation of 3D LV Ecc and Ell from cine-DENSE.
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Affiliation(s)
- Vicky Y Wang
- Veterans Affairs Medical Center, San Francisco, California, USA
| | - Mehrzad Tartibi
- Veterans Affairs Medical Center, San Francisco, California, USA
| | - Yue Zhang
- Veterans Affairs Medical Center, San Francisco, California, USA
| | - Kartiga Selvaganesan
- Department of Biomedical Engineering, University of Berkeley, Berkeley, California, USA
| | - Henrik Haraldsson
- Veterans Affairs Medical Center, San Francisco, California, USA.,Department of Radiology, University of California, San Francisco, California, USA
| | - Daniel A Auger
- Department of Radiology and Biomedical Engineering, University of Virginia, Charlottesville, Virginia, USA.,Medical Metrics, Inc., Houston, Texas, USA
| | - Farshid Faraji
- Veterans Affairs Medical Center, San Francisco, California, USA.,Department of Radiology, University of California, San Francisco, California, USA
| | | | - Kiyoaki Takaba
- Veterans Affairs Medical Center, San Francisco, California, USA
| | | | - Esteban Aguayo
- Veterans Affairs Medical Center, San Francisco, California, USA
| | - David Saloner
- Veterans Affairs Medical Center, San Francisco, California, USA.,Department of Radiology, University of California, San Francisco, California, USA
| | - Arthur W Wallace
- Veterans Affairs Medical Center, San Francisco, California, USA.,Department of Bioengineering, University of California, San Francisco, California, USA.,Department of Anesthesia, University of California, San Francisco, California, USA
| | | | - Frederick H Epstein
- Department of Radiology and Biomedical Engineering, University of Virginia, Charlottesville, Virginia, USA
| | - Julius Guccione
- Veterans Affairs Medical Center, San Francisco, California, USA.,Department of Bioengineering, University of California, San Francisco, California, USA.,Department of Surgery, University of California, San Francisco, California, USA
| | - Liang Ge
- Veterans Affairs Medical Center, San Francisco, California, USA.,Department of Bioengineering, University of California, San Francisco, California, USA.,Department of Surgery, University of California, San Francisco, California, USA
| | - Mark B Ratcliffe
- Veterans Affairs Medical Center, San Francisco, California, USA.,Department of Bioengineering, University of California, San Francisco, California, USA.,Department of Surgery, University of California, San Francisco, California, USA.,Department of Medicine, University of California, San Francisco, California, USA
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2
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Zhao L, Zhang C, Tian J, DeLano M, Ma X. Myocardial Deformation Assessed by MR Feature Tracking in Groups of Patients With Ischemic Heart Disease. J Magn Reson Imaging 2021; 54:808-815. [PMID: 33665932 DOI: 10.1002/jmri.27588] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 02/16/2021] [Accepted: 02/17/2021] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Global myocardial strain assessments have been shown to provide useful measures of contractility in many diseases, but whether feature tracking (FT)-derived strain at rest can differentiate ischemic myocardium from infarcted and remote myocardium in patients with coronary artery disease (CAD) remains unclear. PURPOSE To evaluate the performance of magnetic resonance imaging FT-derived strain in the detection of regional myocardial deformation in ischemic, infarcted, and apparent normal myocardium in CAD. STUDY TYPE Retrospective POPULATION: A total of 109 patients with CAD. FIELD STRENGTH/SEQUENCES Steady-state free-precession rest cine, T1-weighted saturation-recovery fast gradient echo stress/rest perfusion, and two-dimensional phase-sensitive inversion recovery breath-hold late gadolinium enhancement (LGE) tests were performed at 3.0 T. ASSESSMENT Based on perfusion and LGE images, left ventricular (LV) myocardial segments of CAD patients were categorized into ischemic, infarcted, and negative groups. The FT longitudinal (LS) and circumferential strain (CS) of normal subjects and the three CAD groups were calculated. Z-scores of each segment of CAD patients were calculated. STATISTIC TESTS χ2 testing, analysis of variance (ANOVA), and Kruskal-Wallis tests. Z-scores were used to compare the strain between CAD groups. RESULTS There were significant differences in global LS (GLS) and CS (GCS) between healthy controls (GLS: -19.0% ± 1.4%, GCS, -20.9% ± 1.8%), ischemia (GLS: -17.4% ± 2.1%, GCS, -19.6% ± 1.9%), infarction (GLS: -16.4% ± 1.9%, GCS, -17.8% ± 1.9%), and negative patients (GLS: -17.7% ± 1.4%, GCS, -20.9% ± 2.4%) (all P < 0.05). There were significant differences in regional LS and CS between ischemic (LS, -16.1% ± 5.0%, CS, -18.7% ± 5.0%), infarcted (LS, -14.8% ± 5.2%, CS, -15.3% ± 4.8%), and negative segments (LS, -17.6% ± 5.2%, CS, -19.8% ± 4.8%) (all P < 0.05). The differences in the z-scores of regional LS and CS between the ischemic, infarcted, and negative segments were also significant (all P < 0.05). DATA CONCLUSION FT-derived rest strain indices of the LV myocardium of CAD patients were higher compared to healthy controls and varied between ischemic, infarcted, and negative segments. LEVEL OF EVIDENCE 4 TECHNICAL EFFICACY: Stage 5.
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Affiliation(s)
- Lei Zhao
- Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China
| | - Chen Zhang
- Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China
| | - Jie Tian
- Department of Radiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China
| | - Mark DeLano
- Spectrum Health System, Advanced Radiology Services PC, Division of Radiology and Biomedical Imaging, College of Human Medicine, Michigan State University, Michigan, USA
| | - Xiaohai Ma
- Department of Interventional Diagnosis and Therapy, Beijing Anzhen Hospital, Capital Medical University, Beijing, China
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3
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Kawel-Boehm N, Hetzel SJ, Ambale-Venkatesh B, Captur G, Francois CJ, Jerosch-Herold M, Salerno M, Teague SD, Valsangiacomo-Buechel E, van der Geest RJ, Bluemke DA. Reference ranges ("normal values") for cardiovascular magnetic resonance (CMR) in adults and children: 2020 update. J Cardiovasc Magn Reson 2020; 22:87. [PMID: 33308262 PMCID: PMC7734766 DOI: 10.1186/s12968-020-00683-3] [Citation(s) in RCA: 262] [Impact Index Per Article: 65.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Accepted: 10/26/2020] [Indexed: 01/06/2023] Open
Abstract
Cardiovascular magnetic resonance (CMR) enables assessment and quantification of morphological and functional parameters of the heart, including chamber size and function, diameters of the aorta and pulmonary arteries, flow and myocardial relaxation times. Knowledge of reference ranges ("normal values") for quantitative CMR is crucial to interpretation of results and to distinguish normal from disease. Compared to the previous version of this review published in 2015, we present updated and expanded reference values for morphological and functional CMR parameters of the cardiovascular system based on the peer-reviewed literature and current CMR techniques. Further, databases and references for deep learning methods are included.
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Affiliation(s)
- Nadine Kawel-Boehm
- Department of Radiology, Kantonsspital Graubuenden, Loestrasse 170, 7000, Chur, Switzerland
- Institute for Diagnostic, Interventional and Pediatric Radiology (DIPR), Bern University Hospital, University of Bern, Freiburgstrasse 10, 3010, InselspitalBern, Switzerland
| | - Scott J Hetzel
- Department of Biostatistics and Medical Informatics, University of Wisconsin, 610 Walnut St, Madison, WI, 53726, USA
| | - Bharath Ambale-Venkatesh
- Department of Radiology, Johns Hopkins University, 600 N Wolfe Street, Baltimore, MD, 21287, USA
| | - Gabriella Captur
- MRC Unit of Lifelong Health and Ageing At UCL, 5-19 Torrington Place, Fitzrovia, London, WC1E 7HB, UK
- Inherited Heart Muscle Conditions Clinic, Royal Free Hospital NHS Foundation Trust, Hampstead, London, NW3 2QG, UK
| | - Christopher J Francois
- Department of Radiology, University of Wisconsin School of Medicine and Public Health, 600 Highland Avenue, Madison, WI, 53792, USA
| | - Michael Jerosch-Herold
- Department of Radiology, Brigham and Women's Hospital, 75 Francis Street, Boston, MA, 02115, USA
| | - Michael Salerno
- Cardiovascular Division, University of Virginia Health System, 1215 Lee Street, Charlottesville, VA, 22908, USA
| | - Shawn D Teague
- Department of Radiology, National Jewish Health, 1400 Jackson St, Denver, CO, 80206, USA
| | - Emanuela Valsangiacomo-Buechel
- Division of Paediatric Cardiology, University Children's Hospital Zurich, Steinwiesstrasse 75, 8032, Zurich, Switzerland
| | - Rob J van der Geest
- Department of Radiology, Leiden University Medical Center, Albinusdreef 2, 2333ZA, Leiden, The Netherlands
| | - David A Bluemke
- Department of Radiology, University of Wisconsin School of Medicine and Public Health, 600 Highland Avenue, Madison, WI, 53792, USA.
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4
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MacGregor RM, Guo A, Masood MF, Cupps BP, Ewald GA, Pasque MK, Foraker R. Machine Learning Outcome Prediction in Dilated Cardiomyopathy Using Regional Left Ventricular Multiparametric Strain. Ann Biomed Eng 2020; 49:922-932. [PMID: 33006006 DOI: 10.1007/s10439-020-02639-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 09/24/2020] [Indexed: 01/17/2023]
Abstract
The clinical presentation of idiopathic dilated cardiomyopathy (IDCM) heart failure (HF) patients who will respond to medical therapy (responders) and those who will not (non-responders) is often similar. A machine learning (ML)-based clinical tool to identify responders would prevent unnecessary surgery, while targeting non-responders for early intervention. We used regional left ventricular (LV) contractile injury patterns in ML models to identify IDCM HF non-responders. MRI-based multiparametric strain analysis was performed in 178 test subjects (140 normal subjects and 38 IDCM patients), calculating longitudinal, circumferential, and radial strain over 18 LV sub-regions for inclusion in ML analyses. Patients were identified as responders based upon symptomatic and contractile improvement on medical therapy. We tested the predictive accuracy of support vector machines (SVM), logistic regression (LR), random forest (RF), and deep neural networks (DNN). The DNN model outperformed other models, predicting response to medical therapy with an area under the receiver operating characteristic curve (AUC) of 0.94. The top features were longitudinal strain in (1) basal: anterior, posterolateral and (2) mid: posterior, anterolateral, and anteroseptal sub-regions. Regional contractile injury patterns predict response to medical therapy in IDCM HF patients, and have potential application in ML-based HF patient care.
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Affiliation(s)
- Robert M MacGregor
- Department of Surgery, Division of Cardiothoracic Surgery, Barnes-Jewish Hospital, Washington University School of Medicine, Campus Box 8234, 660 S. Euclid Ave., St. Louis, MO, 63110, USA
| | - Aixia Guo
- Institute for Informatics, Division of General Medical Sciences, Washington University School of Medicine, St. Louis, MO, USA
| | - Muhammad F Masood
- Department of Surgery, Division of Cardiothoracic Surgery, Barnes-Jewish Hospital, Washington University School of Medicine, Campus Box 8234, 660 S. Euclid Ave., St. Louis, MO, 63110, USA
| | - Brian P Cupps
- Department of Surgery, Division of Cardiothoracic Surgery, Barnes-Jewish Hospital, Washington University School of Medicine, Campus Box 8234, 660 S. Euclid Ave., St. Louis, MO, 63110, USA
| | - Gregory A Ewald
- John T. Milliken Department of Internal Medicine, Cardiovascular Division, Washington University School of Medicine, St. Louis, MO, USA
| | - Michael K Pasque
- Department of Surgery, Division of Cardiothoracic Surgery, Barnes-Jewish Hospital, Washington University School of Medicine, Campus Box 8234, 660 S. Euclid Ave., St. Louis, MO, 63110, USA.
| | - Randi Foraker
- Institute for Informatics, Division of General Medical Sciences, Washington University School of Medicine, St. Louis, MO, USA
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5
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Andrews C, Cupps BP, Pasque MK, Rudy Y. Electromechanics of the Normal Human Heart In Situ. Circ Arrhythm Electrophysiol 2019; 12:e007484. [PMID: 31698936 DOI: 10.1161/circep.119.007484] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Christopher Andrews
- Department of Biomedical Engineering, Cardiac Bioelectricity and Arrhythmia Center, Washington University, St. Louis, MO (C.A., Y.R.)
| | - Brian P Cupps
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, St. Louis, MO (B.P.C., M.K.P.)
| | - Michael K Pasque
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, St. Louis, MO (B.P.C., M.K.P.)
| | - Yoram Rudy
- Department of Biomedical Engineering, Cardiac Bioelectricity and Arrhythmia Center, Washington University, St. Louis, MO (C.A., Y.R.)
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6
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Lehmonen L, Vuorinen AM, Koivuniemi R, Leirisalo-Repo M, Holmström M, Kivistö S, Kaasalainen T. One-Year Follow-up Study Detects Myocardial Changes with Cardiovascular Magnetic Resonance Tagging in Active Rheumatoid Arthritis. Acad Radiol 2018; 25:476-485. [PMID: 29199058 DOI: 10.1016/j.acra.2017.10.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Revised: 10/23/2017] [Accepted: 10/24/2017] [Indexed: 02/02/2023]
Abstract
RATIONALE AND OBJECTIVES To evaluate the effects of 1 year of medical treatment on myocardial function in active rheumatoid arthritis (RA). MATERIALS AND METHODS Thirty-nine female patients with RA without any known cardiovascular disease underwent a cardiovascular magnetic resonance (CMR) examination before and after 1 year of antirheumatic treatment. The population comprised untreated active early RA (ERA) and chronic RA patients, who were grouped accordingly. The CMR protocol included volumetric determinations, late gadolinium enhancement imaging, myocardial tagging, and native T1 mapping. DAS28-CRP disease activity scores were calculated before and after the treatment. RESULTS Results are reported as median (quartile 1-quartile 3). Time to peak diastolic filling rate improved in ERA (495 [443-561] ms vs 441 [340-518] ms, P = .018). Peak diastolic mean mid short-axis circumferential strain rate of all six segments was improved (82 [74-91] %/s vs 91 [77-100] %/s, P = .05), particularly in the anterior segment (82 [63-98] %/s vs 86 [77-109] %/s, P = .013). DAS28-CRP decreased in ERA (3.8 [3.2-4.1] vs 1.6 [1.4-2.2], P < .001). In chronic RA, no statistically significant improvement was detected. CONCLUSIONS Early treatment of active RA is important, as myocardial function detected with CMR tagging improved in ERA in parallel with decreasing inflammatory activity.
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7
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Lindman BR, Liu Q, Cupps BP, Woodard PK, Novak E, Vatterott AM, Koerner DJ, Kulshrestha K, Pasque MK. Heterogeneity of systolic dysfunction in patients with severe aortic stenosis and preserved ejection fraction. J Card Surg 2018; 32:454-461. [PMID: 28833636 DOI: 10.1111/jocs.13183] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
BACKGROUND AND AIM Left ventricular (LV) systolic strain has been shown to be an early marker of LV dysfunction in patients with severe aortic stenosis (AS) despite preserved ejection fraction (EF). Echocardiography has provided useful data on regional LV strain patterns, but is not as sensitive as magnetic resonance imaging (MRI). No prior studies have used MRI-based strain analysis to characterize regional three-dimensional strain in patients with severe AS. METHODS Twelve patients with severe AS and preserved EF underwent MRI-based multiparametric strain analysis. Circumferential and longitudinal strain values were calculated at individual points throughout the LV and analyzed in 12 discrete regions. Strain values were compared to a database of normal controls. RESULTS Compared to control patients, circumferential strain in AS patients was significantly reduced at the base (P = 0.002), mid (P = 0.042), and inferior walls (P < 0.001). Longitudinal strain was significantly reduced at the base (P < 0.001), mid (P < 0.001), anterior (P < 0.001), and septal (P < 0.001) walls. Among patients with AS, there was heterogeneity in the location and severity of abnormalities in circumferential and longitudinal strains despite the presence of a preserved EF and lack of prior myocardial infarction. CONCLUSIONS LV systolic strain is significantly impaired in patients with AS and preserved EF compared to healthy volunteers. Abnormalities in circumferential and longitudinal strains were heterogeneously distributed across the LV of patients with AS, allowing us to identify sentinel regions that may reflect the earliest signs of developing LV dysfunction.
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Affiliation(s)
| | - Qi Liu
- Leon H. Charney Division of Cardiology, New York University School of Medicine, New York, New York
| | - Brian P Cupps
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, St. Louis, Missouri
| | - Pamela K Woodard
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri
| | - Eric Novak
- Division of Cardiovascular, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri
| | - Anna M Vatterott
- Division of Cardiovascular, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri
| | - Danielle J Koerner
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, St. Louis, Missouri
| | - Kevin Kulshrestha
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, St. Louis, Missouri
| | - Michael K Pasque
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, St. Louis, Missouri
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8
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Topographic mapping of left ventricular regional contractile injury in ischemic mitral regurgitation. J Thorac Cardiovasc Surg 2016; 154:149-158.e1. [PMID: 28109612 DOI: 10.1016/j.jtcvs.2016.11.055] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 10/28/2016] [Accepted: 11/01/2016] [Indexed: 12/19/2022]
Abstract
OBJECTIVE Restrictive leaflet tethering resulting from regional left ventricular (LV) contractile injury causes ischemic mitral regurgitation (MR). We hypothesized that 3-dimensional LV topographic mapping by MRI-based multiparametric strain analysis could characterize the regional contractile injury patterns that differentiate ischemic coronary artery disease patients who have ischemic MR from those who do not. METHODS Magnetic resonance imaging-based multiparametric strain data were calculated for 15,300 LV grid points in 100 normal volunteers. Strain parameters from ischemic MR (n = 10) and ischemic no-MR (n = 36) patients were then normalized to this normal human strain database with z score quantification of standard deviation from the normal mean. Mean multiparametric strain z scores were calculated for 18 LV subregions (basilar/mid/apical levels; 6 LV regions). Mean strain z scores for papillary muscle-related (basilar/mid levels of anterolateral, posterolateral, and posterior) and nonpapillary muscle-related (all other) subregions were compared between ischemic MR and ischemic no-MR groups. RESULTS Across all patients, contractile injury was greater in the papillary muscle-related regions compared with the nonpapillary regions (P = .007). In the papillary regions, contractile injury was greater in the ischemic MR group compared with the no-MR group (z scores, 1.91 ± 1.13 vs 1.20 ± 1.01, respectively; P < .001). Strain values in the nonpapillary muscle-related subregions were not different between the 2 groups (1.31 ± 1.04 vs 1.20 ± 1.03; P = .301). CONCLUSIONS Multiparametric strain analysis demonstrated severe normalized contractile injury in the papillary muscle-related LV subregions in patients with ischemic MR. The mean degree of normalized injury approached 2 standard deviations and was significantly worse than the levels seen in ischemic no-MR patients.
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9
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Kar J, Cupps B, Zhong X, Koerner D, Kulshrestha K, Neudecker S, Bell J, Craddock H, Pasque M. Preliminary investigation of multiparametric strain Z-score (MPZS) computation using displacement encoding with simulated echoes (DENSE) and radial point interpretation method (RPIM). J Magn Reson Imaging 2016; 44:993-1002. [PMID: 27038246 PMCID: PMC5028227 DOI: 10.1002/jmri.25239] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Revised: 02/28/2016] [Accepted: 02/29/2016] [Indexed: 01/19/2023] Open
Abstract
PURPOSE To describe and assess an automated normalization method for identifying sentinel (septal) regions of myocardial dysfunction in nonischemic, nonvalvular dilated cardiomyopathy (DCM), using an unprecedented combination of the navigator-gated 3D spiral displacement encoding with stimulated echoes (DENSE) magnetic resonance imaging (MRI), radial point interpolation (RPIM) and multiparametric strain z-score (MPZS). MATERIALS AND METHODS Navigator-gated 3D spiral DENSE, in a 1.5T MRI machine, was used for acquiring the displacement encoded complex images, MR Analytical Software System (MASS) for automated boundary detection and automated meshfree RPIM for left-ventricular (LV) myocardial strain computation to analyze MPZS in 36 subjects (with n = 17 DCM patients). Pearson's r correlation established relations between global/sentinel MPZS and ejection fraction (EF). The time taken for combined RPIM-MPZS computations was recorded. RESULTS Maximum MPZS differences were seen between anteroseptal and posterolateral regions in the base (2.0 ± 0.3 vs. 0.9 ± 0.5) and the mid-wall (2.1 ± 0.4 vs. 1.0 ± 0.4). These regional differences were found to be consistent with historically documented septal injury in nonischemic DCM. Correlations were 0.6 between global MPZS and EF, and 0.7 between sentinel MPZS and EF. The time taken for combined RPIM-MPZS computations per subject was 18.9 ± 5.9 seconds. CONCLUSION Heterogeneous contractility found in the sentinel regions with the current automated MPZS computation scheme and the correlation found between MPZS and EF may lead to the creation of a new clinical metric in LV DCM surveillance. J. MAGN. RESON. IMAGING 2016;44:993-1002.
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MESH Headings
- Aged
- Algorithms
- Cardiomyopathy, Dilated/complications
- Cardiomyopathy, Dilated/diagnostic imaging
- Cardiomyopathy, Dilated/physiopathology
- Computer Simulation
- Elastic Modulus
- Elasticity Imaging Techniques/methods
- Female
- Humans
- Image Enhancement/methods
- Image Interpretation, Computer-Assisted/methods
- Imaging, Three-Dimensional/methods
- Magnetic Resonance Imaging/methods
- Male
- Middle Aged
- Models, Cardiovascular
- Pattern Recognition, Automated/methods
- Pilot Projects
- Reproducibility of Results
- Sensitivity and Specificity
- Signal Processing, Computer-Assisted
- Stress, Mechanical
- Stroke Volume
- Tensile Strength
- Ventricular Dysfunction, Left/diagnostic imaging
- Ventricular Dysfunction, Left/etiology
- Ventricular Dysfunction, Left/physiopathology
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Affiliation(s)
- Julia Kar
- Department of Surgery, School of Medicine, Washington University, St. Louis, Missouri, USA.
| | - Brian Cupps
- Department of Surgery, School of Medicine, Washington University, St. Louis, Missouri, USA
| | - Xiaodong Zhong
- Department of Surgery, School of Medicine, Washington University, St. Louis, Missouri, USA
| | - Danielle Koerner
- Department of Surgery, School of Medicine, Washington University, St. Louis, Missouri, USA
| | - Kevin Kulshrestha
- Department of Surgery, School of Medicine, Washington University, St. Louis, Missouri, USA
| | - Samuel Neudecker
- Department of Surgery, School of Medicine, Washington University, St. Louis, Missouri, USA
| | - Jennifer Bell
- Department of Surgery, School of Medicine, Washington University, St. Louis, Missouri, USA
| | - Heidi Craddock
- Department of Surgery, School of Medicine, Washington University, St. Louis, Missouri, USA
| | - Michael Pasque
- Department of Surgery, School of Medicine, Washington University, St. Louis, Missouri, USA
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10
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Henn MC, Cupps BP, Kar J, Kulshrestha K, Koerner D, Braverman AC, Pasque MK. Quantifying "normalized" regional left ventricular contractile function in ischemic coronary artery disease. J Thorac Cardiovasc Surg 2015; 150:240-6. [PMID: 25940418 PMCID: PMC4490013 DOI: 10.1016/j.jtcvs.2015.03.049] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Revised: 03/18/2015] [Accepted: 03/30/2015] [Indexed: 11/21/2022]
Abstract
OBJECTIVE When significant coronary lesions are identified by angiography, regional left ventricular (LV) contractile function often plays a role in determining candidacy for revascularization. To improve on current subjective and nonquantitative metrics of regional LV function, we tested a z-score "normalization" of regional strain information quantified from clinically acquired high-resolution LV geometric datasets. METHODS Test subjects (n = 120) underwent cardiac MRI with multiple 3-dimensional strain parameters calculated from tissue tag-plane displacement data. Sixty healthy volunteers contributed strain parameter data at each of 15,300 LV grid points, to form a normal human strain database. Point-specific database comparisons were made in 60 patients who had documented coronary artery disease (CAD), by angiography. Patient-specific, color-coded 3-dimensional LV maps of z-score-normalized contractile function were generated. RESULTS Blinded clinical review indicated that 55% (33 of 60) of the patients with CAD had significant regional contractile abnormalities by 1 of 3 "gold-standard" criteria: (1) Q waves on electrocardiography (ECG); (2) infarct on radionuclide single-photon emission computed tomography (SPECT); or (3) akinesia or dyskinesia on echocardiography. Consistency among all gold-standard metrics was found for only 19% (6 of 31) of patients with CAD who had ≥2 available metrics. Blinded MRI-based, multiparametric, strain z-score localization of contractile abnormalities was accurate in 89% (ECG), 97% (SPECT), and 95% (echocardiography). CONCLUSIONS Nonsubjective normalization of regional LV contractile function by z-score calculation from a normal human strain database can localize and quantitatively display regional wall motion abnormalities in patients with CAD. This high-resolution localization of regional wall motion abnormalities may help improve the accuracy of therapeutic intervention in patients who have CAD.
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Affiliation(s)
- Matthew C Henn
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, St Louis, Mo
| | - Brian P Cupps
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, St Louis, Mo
| | - Julia Kar
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, St Louis, Mo
| | - Kevin Kulshrestha
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, St Louis, Mo
| | - Danielle Koerner
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, St Louis, Mo
| | - Alan C Braverman
- Cardiovascular Division, Department of Medicine, Washington University School of Medicine, St Louis, Mo
| | - Michael K Pasque
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, St Louis, Mo.
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Kawel-Boehm N, Maceira A, Valsangiacomo-Buechel ER, Vogel-Claussen J, Turkbey EB, Williams R, Plein S, Tee M, Eng J, Bluemke DA. Normal values for cardiovascular magnetic resonance in adults and children. J Cardiovasc Magn Reson 2015; 17:29. [PMID: 25928314 PMCID: PMC4403942 DOI: 10.1186/s12968-015-0111-7] [Citation(s) in RCA: 521] [Impact Index Per Article: 57.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Accepted: 01/06/2015] [Indexed: 01/17/2023] Open
Abstract
Morphological and functional parameters such as chamber size and function, aortic diameters and distensibility, flow and T1 and T2* relaxation time can be assessed and quantified by cardiovascular magnetic resonance (CMR). Knowledge of normal values for quantitative CMR is crucial to interpretation of results and to distinguish normal from disease. In this review, we present normal reference values for morphological and functional CMR parameters of the cardiovascular system based on the peer-reviewed literature and current CMR techniques and sequences.
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Affiliation(s)
- Nadine Kawel-Boehm
- Department of Radiology, Kantonsspital Graubuenden, Loestrasse 170, 7000, Chur, Switzerland.
| | - Alicia Maceira
- Cardiac Imaging Unit, Eresa Medical Center, C/Marqués de San Juan s/n, 46015, Valencia, Spain.
| | | | - Jens Vogel-Claussen
- Department of Diagnostic and Interventional Radiology, Hannover Medical School, OE 8220, Carl-Neuberg-Str 1, 30625, Hannover, Germany.
| | - Evrim B Turkbey
- Radiology and Imaging Sciences/ Clinical Image Processing Service, Clinical Center, NIH, 10 Center Drive, Bethesda, MD, 20892, USA.
| | - Rupert Williams
- The Rayne Institute, King's College London, St Thomas' Hospital, London, SE1 7EH, UK.
| | - Sven Plein
- Multidisciplinary Cardiovascular Research Centre & Leeds Institute for Cardiovascular and Metabolic Medicine, LIGHT Laboratories, Clarendon Way, University of Leeds, Leeds, LS2 9JT, UK.
| | - Michael Tee
- Radiology and Imaging Sciences, National Institute of Biomedical Imaging and Bioengineering, 10 Center Drive, Bethesda, MD, 20892-1074, USA.
| | - John Eng
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, 600 North Wolfe Street, Baltimore, MD, 21287, USA.
| | - David A Bluemke
- Radiology and Imaging Sciences, National Institute of Biomedical Imaging and Bioengineering, 10 Center Drive, Bethesda, MD, 20892-1074, USA.
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12
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Maniar HS, Brady BD, Lee U, Cupps BP, Kar J, Wallace KM, Pasque MK. Early left ventricular regional contractile impairment in chronic mitral regurgitation occurs in a consistent, heterogeneous pattern. J Thorac Cardiovasc Surg 2014; 148:1694-9. [PMID: 25260278 DOI: 10.1016/j.jtcvs.2014.05.088] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Revised: 05/08/2014] [Accepted: 05/23/2014] [Indexed: 10/25/2022]
Abstract
OBJECTIVES The clinical guidelines for asymptomatic patients with chronic mitral regurgitation (MR) use the ejection fraction (EF) to trigger surgical referral. We hypothesized that the EF is not sensitive enough to detect the earliest contractile injury in chronic MR and that the injury associated with chronic MR is not global but heterogeneous, occurring regionally and predictably, before the onset of global left ventricular (LV) dysfunction. METHODS Fifteen patients with chronic MR and normal LVEF by echocardiography underwent cardiac magnetic resonance imaging with tissue tagging. Point-specific comparisons (at 15,300 LV grid points) of multiple strain parameters to a normal human strain database allowed normalization of patient-specific regional contractile function. Data were mapped over patient-specific 3-dimensional geometry and averaged across 6 LV regions. RESULTS Global LV longitudinal and circumferential myocardial strains were normal for all 15 patients with MR compared with normal controls (P>.05). Despite preserved global function, the anteroseptum and posteroseptum demonstrated significantly worse contractile function compared with other LV regions (P=.003 and P=.035, respectively). Hypercontractile regions (lateral walls) appeared to compensate (P=.002) for the reduced septal contractile function, masking injury detection by global indexes. CONCLUSIONS The earliest contractile injury seen in patients with MR is heterogeneous and consistently distributed along the LV septum. Compensatory responses include hypercontractility of other regions. These data suggest that rather than relying on global LV contractile metrics, which cannot detect early injury, patients might be better served by undergoing directed surveillance of "sentinel" LV regions (LV septum) with high-resolution metrics of regional contractile function.
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Affiliation(s)
- Hersh S Maniar
- Department of Surgery, Washington University School of Medicine, St Louis, Mo.
| | - Beckah D Brady
- Department of Surgery, Washington University School of Medicine, St Louis, Mo
| | - Urvi Lee
- Department of Surgery, Washington University School of Medicine, St Louis, Mo
| | - Brian P Cupps
- Department of Surgery, Washington University School of Medicine, St Louis, Mo
| | - Julia Kar
- Department of Surgery, Washington University School of Medicine, St Louis, Mo
| | - Kathleen M Wallace
- Department of Surgery, Washington University School of Medicine, St Louis, Mo
| | - Michael K Pasque
- Department of Surgery, Washington University School of Medicine, St Louis, Mo
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Kar J, Knutsen AK, Cupps BP, Zhong X, Pasque MK. Three-dimensional regional strain computation method with displacement encoding with stimulated echoes (DENSE) in non-ischemic, non-valvular dilated cardiomyopathy patients and healthy subjects validated by tagged MRI. J Magn Reson Imaging 2014; 41:386-96. [PMID: 24753028 DOI: 10.1002/jmri.24576] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Accepted: 01/03/2014] [Indexed: 11/11/2022] Open
Abstract
PURPOSE Fast cine displacement encoding with stimulated echoes (DENSE) MR has higher spatial resolution and enables rapid postprocessing. Thus we compared the accuracy of regional strains computation by DENSE with tagged MR in healthy and non-ischemic, non-valvular dilated cardiomyopathy (DCM) subjects. MATERIALS AND METHODS Validation of three-dimensional regional strains computed with DENSE was conducted in reference to standard tagged MRI (TMRI) in healthy subjects and patients with DCM. Additional repeatability studies in healthy subjects were conducted to increase confidence in DENSE. A meshfree multiquadrics radial point interpolation method (RPIM) was used for computing Lagrange strains in sixteen left ventricular segments. Bland-Altman analysis and Student's t-tests were conducted to observe similarities in regional strains between sequences and in DENSE repeatability studies. RESULTS Regional circumferential strains ranged from -0.21 ± 0.07 (Lateral-Apex) to -0.11 ± 0.05 (Posterorseptal-Base) in healthy subjects and -0.15 ± 0.04 (Anterior-Apex) to -0.02 ± 0.08 (Posterorseptal-Base) in DCM patients. Computed mean differences in regional circumferential strain from the DENSE-TMRI comparison study was 0.01 ± 0.03 (95% limits of agreement) in normal subjects, -0.01 ± 0.06 in DCM patients and 0.0 ± 0.02 in repeatability studies, with similar agreements in longitudinal and radial strains. CONCLUSION We found agreement between DENSE and tagged MR in patients and volunteers in terms of evaluation of regional strains.
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Affiliation(s)
- Julia Kar
- Department of Surgery School of Medicine, Washington University, St Louis, Missouri, USA
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14
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Del-Canto I, López-Lereu MP, Monmeneu JV, Croisille P, Clarysse P, Chorro FJ, Bodí V, Moratal D. Characterization of normal regional myocardial function by MRI cardiac tagging. J Magn Reson Imaging 2013; 41:83-92. [PMID: 24339144 DOI: 10.1002/jmri.24539] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Accepted: 11/14/2013] [Indexed: 11/06/2022] Open
Abstract
PURPOSE The aim of this study was to establish reference values for segmental myocardial strain measured by magnetic resonance (MR) cardiac tagging in order to characterize the regional function of the heart. MATERIAL AND METHODS We characterized the left ventricular (LV) systolic deformation in 39 subjects (26 women and 13 men, age 58.8 ± 11.6 years) whose cardiological study had not revealed any significant abnormality. The deformation was measured from MR-tagged (Siemens 1.5T MR) images using an algorithm based on sine wave modeling. Circumferential and radial peak systolic strain values along with the torsion angle and circumferential-longitudinal (CL) shear were determined in 16 LV segments in order to settle the reference values for these parameters. RESULTS Circumferential strain was highest at the anterior and lateral walls (-20.2 ± 4.0% and -21.8 ± 4.3%, respectively; P < 0.05) and was lowest at the base level (-17.2 ± 3.1% vs. -20.1 ± 3.1% "mid level," P < 0.05; -17.2 ± 3.1% vs. -20.3 ± 3.0% "apical level," P < 0.05). Radial strain highest values were from inferior and lateral walls (13.7 ± 7.4% and 12.8 ± 7.8%, respectively; P < 0.05) and it was lowest medially (9.4 ± 4.1% vs. 13.1 ± 4.1% "base level," P < 0.05; 9.4 ± 4.1% vs. 12.1 ± 4.4% "apical level," P < 0.05). Torsion angle (counterclockwise when viewed from the apex) increased with the distance from the base (7.9 ± 2.4° vs. 16.8 ± 4.4°, P < 0.05), and the highest and lowest values were found at lateral (medial lateral: 12.0 ± 4.4°, apical lateral: 25.1 ± 6.4°, P < 0.05) and septal wall (medial septal: 3.6 ± 2.1°, apical septal: 8.3 ± 5.3°, P < 0.05), respectively. These differences were found again in CL shear values, around the LV circumference. However, CL shear remained constant with increasing distance from the base (9.1 ± 2.6°, medium and 9.8 ± 2.4°, apex). CONCLUSION In summary, this study provides reference values for the assessment of regional myocardial function by MR cardiac tagging. Comparison of patient deformation parameters with normal deformation patterns may permit early detection of regional systolic dysfunction.
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Affiliation(s)
- Irene Del-Canto
- Fundación de Investigación del Hospital Clínico Universitario de Valencia, INCLIVA, Valencia, Spain
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15
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Kar J, Knutsen AK, Cupps BP, Pasque MK. A validation of two-dimensional in vivo regional strain computed from displacement encoding with stimulated echoes (DENSE), in reference to tagged magnetic resonance imaging and studies in repeatability. Ann Biomed Eng 2013; 42:541-54. [PMID: 24150239 DOI: 10.1007/s10439-013-0931-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Accepted: 10/15/2013] [Indexed: 01/23/2023]
Abstract
Fast cine displacement encoding with stimulated echoes (DENSE) has comparative advantages over tagged MRI (TMRI) including higher spatial resolution and faster post-processing. This study computed regional radial and circumferential myocardial strains with DENSE displacements and validated it in reference to TMRI, according to American Heart Association (AHA) guidelines for standardized segmentation of regions in the left ventricle (LV). This study was therefore novel in examining agreement between the modalities in 16 AHA recommended LV segments. DENSE displacements were obtained with spatiotemporal phase unwrapping and TMRI displacements obtained with a conventional tag-finding algorithm. A validation study with a rotating phantom established similar shear strain between modalities prior to in vivo studies. A novel meshfree nearest node finite element method (NNFEM) was used for rapid computation of Lagrange strain in both phantom and in vivo studies in both modalities. Also novel was conducting in vivo repeatability studies for observing recurring strain patterns in DENSE and increase confidence in it. Comprehensive regional strain agreements via Bland-Altman analysis between the modalities were obtained. Results from the phantom study showed similar radial-circumferential shear strains from the two modalities. Mean differences in regional in vivo circumferential strains were -0.01 ± 0.09 (95% limits of agreement) from comparing the modalities and -0.01 ± 0.07 from repeatability studies. Differences and means from comparison and repeatability studies were uncorrelated (p > 0.05) indicating no increases in differences with increased strain magnitudes. Bland-Altman analysis and similarities in regional strain distribution within the myocardium showed good agreements between DENSE and TMRI and show their interchangeability. NNFEM was also established as a common framework for computing strain in both modalities.
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Affiliation(s)
- Julia Kar
- Department of Surgery, School of Medicine, Washington University in St. Louis, 660 S. Euclid Ave., St Louis, MO, 63110, USA,
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Jeung MY, Germain P, Croisille P, ghannudi SE, Roy C, Gangi A. Myocardial Tagging with MR Imaging: Overview of Normal and Pathologic Findings. Radiographics 2012; 32:1381-98. [DOI: 10.1148/rg.325115098] [Citation(s) in RCA: 89] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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Brady BD, Knutsen AK, Ma N, Gardner R, Taggar AK, Cupps BP, Kouchoukos NT, Pasque MK. MRI-based multiparametric strain analysis predicts contractile recovery after aortic valve replacement for aortic insufficiency. J Card Surg 2012; 27:415-22. [PMID: 22612862 DOI: 10.1111/j.1540-8191.2012.01477.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND Guidelines for referral of chronic aortic insufficiency (AI) patients for aortic valve replacement (AVR) suggest that surgery can be delayed until symptoms or reduction in left ventricular (LV) contractile function occur. The frequent occurrence of reduced LV contractile function after AVR for chronic AI suggests that new contractile metrics for surgical referral are needed. METHODS In 16 chronic AI patients, cardiac MRI tagged images were analyzed before and 21.5 ± 13.8 months after AVR to calculate LV systolic strain. Average measurements of three strain parameters were obtained for each of 72 LV regions, normalized using a normal human strain database (n = 63), and combined into a composite index (multiparametric strain z score [MSZ]) representing standard deviation from the normal regional average. RESULTS Preoperative global MSZ (72-region average) correlated with post-AVR global MSZ (R(2) = 0.825, p < 0.001). Preoperative global MSZ also predicts improvement of impaired regions (N = 271 regions from 14 AI patients, R(2) = 0.392, p < 0.001). Preoperative MRI-based LV ejection fraction (LVEF) is also predictive (r = 0.410, p < 0.001). Although global preoperative MSZ had a significantly higher correlation than preoperative LVEF with improvement of injured regions (p < 0.001), both measures convey the same phenomenon. CONCLUSIONS Global preoperative MRI-based multiparametric strain predicts global strain postoperatively, as well as improvement of regions (n = 72 per LV) with impaired contractile function. Global contractile function is an important correlate with improvement in regionally impaired contractile function, perhaps reflecting total AI volume-overload burden (severity/duration of AI).
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Affiliation(s)
- Beckah D Brady
- Department of Surgery, Washington University School of Medicine, St. Louis, Missouri, USA
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Knutsen AK, Ma N, Taggar AK, Brady BD, Cupps BP, Pasque MK. Heterogeneous distribution of left ventricular contractile injury in chronic aortic insufficiency. Ann Thorac Surg 2012; 93:1121-7. [PMID: 22381452 DOI: 10.1016/j.athoracsur.2011.12.067] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2011] [Revised: 12/22/2011] [Accepted: 12/28/2011] [Indexed: 11/26/2022]
Abstract
BACKGROUND Global systolic strain has been described previously in patients with chronic aortic insufficiency (AI). This study explored regional differences in contractile injury. METHODS Tagged magnetic resonance images of the left ventricle (LV) were acquired and analyzed to calculate systolic strain in 42 patients with chronic AI. Multiparametric systolic strain analysis was applied to relate cardiac function in AI patients to a normal strain database (N = 60). AI patients were classified as having normal or poor function based on their results. A two-way repeated-measures analysis of variance was applied to analyze regional differences in injury. RESULTS The mean and standard deviation of raw strain values (circumferential strain, longitudinal strain, and minimum principal strain angle) are presented over the entire LV in our normal strain database. Of the 42 patients with AI, 15 could be defined as having poor function by multiparametric systolic strain analysis. In AI patients with poor function, statistical analysis showed significant differences in injury between standard LV regions (F(3.69,44.33) = 3.47, p = 0.017) and levels (F(1.49,17.88) = 4.41, p = 0.037) of the LV, whereas no significant differences were seen in the group with normal cardiac function. CONCLUSIONS Patients with poor function, as defined by multiparametric systolic strain z scores, exhibit a consistent, heterogeneous pattern of contractile injury in which the septum and posterior regions at the base are most injured.
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Affiliation(s)
- Andrew K Knutsen
- Department of Surgery, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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Ibrahim ESH. Myocardial tagging by cardiovascular magnetic resonance: evolution of techniques--pulse sequences, analysis algorithms, and applications. J Cardiovasc Magn Reson 2011; 13:36. [PMID: 21798021 PMCID: PMC3166900 DOI: 10.1186/1532-429x-13-36] [Citation(s) in RCA: 203] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2011] [Accepted: 07/28/2011] [Indexed: 02/06/2023] Open
Abstract
Cardiovascular magnetic resonance (CMR) tagging has been established as an essential technique for measuring regional myocardial function. It allows quantification of local intramyocardial motion measures, e.g. strain and strain rate. The invention of CMR tagging came in the late eighties, where the technique allowed for the first time for visualizing transmural myocardial movement without having to implant physical markers. This new idea opened the door for a series of developments and improvements that continue up to the present time. Different tagging techniques are currently available that are more extensive, improved, and sophisticated than they were twenty years ago. Each of these techniques has different versions for improved resolution, signal-to-noise ratio (SNR), scan time, anatomical coverage, three-dimensional capability, and image quality. The tagging techniques covered in this article can be broadly divided into two main categories: 1) Basic techniques, which include magnetization saturation, spatial modulation of magnetization (SPAMM), delay alternating with nutations for tailored excitation (DANTE), and complementary SPAMM (CSPAMM); and 2) Advanced techniques, which include harmonic phase (HARP), displacement encoding with stimulated echoes (DENSE), and strain encoding (SENC). Although most of these techniques were developed by separate groups and evolved from different backgrounds, they are in fact closely related to each other, and they can be interpreted from more than one perspective. Some of these techniques even followed parallel paths of developments, as illustrated in the article. As each technique has its own advantages, some efforts have been made to combine different techniques together for improved image quality or composite information acquisition. In this review, different developments in pulse sequences and related image processing techniques are described along with the necessities that led to their invention, which makes this article easy to read and the covered techniques easy to follow. Major studies that applied CMR tagging for studying myocardial mechanics are also summarized. Finally, the current article includes a plethora of ideas and techniques with over 300 references that motivate the reader to think about the future of CMR tagging.
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Micromechanical regulation in cardiac myocytes and fibroblasts: implications for tissue remodeling. Pflugers Arch 2011; 462:105-17. [PMID: 21308471 DOI: 10.1007/s00424-011-0931-8] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2010] [Revised: 01/25/2011] [Accepted: 01/25/2011] [Indexed: 10/18/2022]
Abstract
Cells of the myocardium are at home in one of the most mechanically dynamic environments in the body. At the cellular level, pulsatile stimuli of chamber filling and emptying are experienced as cyclic strains (relative deformation) and stresses (force per unit area). The intrinsic characteristics of tension-generating myocytes and fibroblasts thus have a continuous mechanical interplay with their extrinsic surroundings. This review explores the ways that the micromechanics at the scale of single cardiac myocytes and fibroblasts have been measured, modeled, and recapitulated in vitro in the context of adaptation. Both types of cardiac cells respond to externally applied strain, and many of the intracellular mechanosensing pathways have been identified with the careful manipulation of experimental variables. In addition to strain, the extent of loading in myocytes and fibroblasts is also regulated by cues from the microenvironment such as substrate surface chemistry, stiffness, and topography. Combinations of these structural cues in three dimensions are needed to mimic the micromechanical complexity derived from the extracellular matrix of the developing, healthy, or pathophysiologic heart. An understanding of cardiac cell micromechanics can therefore inform the design and composition of tissue engineering scaffolds or stem cell niches for future applications in regenerative medicine.
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