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Alachkar MN, Mischke T, Mahnkopf C. [Cardiac magnetic resonance imaging and the myocardium : Differentiation between vital and nonvital tissue]. Herzschrittmacherther Elektrophysiol 2022; 33:272-277. [PMID: 35781833 DOI: 10.1007/s00399-022-00874-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 06/13/2022] [Indexed: 06/15/2023]
Abstract
Cardiac magnetic resonance (cMR), a well-established imaging tool, is indispensable in the diagnosis and management of cardiovascular disease. Given its high spatial resolution and ability to characterize tissue, cMR represents the gold standard in determining myocardial viability. Gadolinium-based contrast-enhanced cMR can accurately identify myocardial scars and fibrosis in the ventricle and the atria, and differentiate it from normal myocardium. Gadolinium is an extracellular molecule which has been shown to be safe and beneficial in magnetic resonance imaging (MRI). Due to the larger extracellular space in myocardial scars, there is more uptake (wash-in) and slower elimination (wash-out) of gadolinium in those areas as opposed to normal myocardium. When imaged several minutes after intravenous administration of gadolinium, nonviable myocardial areas appear brighter than viable myocardium. The use of late-gadolinium enhancement (LGE) technique in assessing myocardial viability has been shown to highly correlate with histological examinations. Furthermore, this technique is highly reproducible and has very high intra- and interobserver agreement. Extent of LGE after myocardial infarction predicts the occurrence of adverse cardiovascular events. Moreover, LGE is highly accurate in predicting functional recovery of dysfunctional myocardial segments in patients undergoing revascularization and consequently has a key role in guiding revascularization procedures. In addition, use of LGE in the identification of myocardial fibrosis or myocardial damage in inflammatory myocardial disease helps to differentiate the type of cardiomyopathy and to predict sudden cardiac death among patients with heart failure. The role of LGE-MRI in the field of electrophysiology through recognition of different substrate for arrythmias and guiding the ablation therapy is steadily increasing and has fundamentally changed our understanding of atrial myopathy.
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Affiliation(s)
- Mhd Nawar Alachkar
- Klinik für Kardiologie und Angiologie, REGIOMED Klinikum Coburg, Ketschendorfer Str. 33, 96450, Coburg, Deutschland.
| | - Thomas Mischke
- Klinik für Kardiologie und Angiologie, REGIOMED Klinikum Coburg, Ketschendorfer Str. 33, 96450, Coburg, Deutschland
| | - Christian Mahnkopf
- Klinik für Kardiologie und Angiologie, REGIOMED Klinikum Coburg, Ketschendorfer Str. 33, 96450, Coburg, Deutschland
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2
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Ciaccio EJ, Anter E, Coromilas J, Wan EY, Yarmohammadi H, Wit AL, Peters NS, Garan H. Structure and function of the ventricular tachycardia isthmus. Heart Rhythm 2022; 19:137-153. [PMID: 34371192 DOI: 10.1016/j.hrthm.2021.08.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 07/22/2021] [Accepted: 08/01/2021] [Indexed: 12/24/2022]
Abstract
Catheter ablation of postinfarction reentrant ventricular tachycardia (VT) has received renewed interest owing to the increased availability of high-resolution electroanatomic mapping systems that can describe the VT circuits in greater detail, and the emergence and need to target noninvasive external beam radioablation. These recent advancements provide optimism for improving the clinical outcome of VT ablation in patients with postinfarction and potentially other scar-related VTs. The combination of analyses gleaned from studies in swine and canine models of postinfarction reentrant VT, and in human studies, suggests the existence of common electroanatomic properties for reentrant VT circuits. Characterizing these properties may be useful for increasing the specificity of substrate mapping techniques and for noninvasive identification to guide ablation. Herein, we describe properties of reentrant VT circuits that may assist in elucidating the mechanisms of onset and maintenance, as well as a means to localize and delineate optimal catheter ablation targets.
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Affiliation(s)
- Edward J Ciaccio
- Department of Medicine, Division of Cardiology, Columbia University College of Physicians and Surgeons, New York, New York; ElectroCardioMaths Programme, Imperial Centre for Cardiac Engineering, Imperial College London, London, United Kingdom.
| | - Elad Anter
- Department of Cardiovascular Medicine, Cardiac Electrophysiology, Cleveland Clinic, Cleveland, Ohio
| | - James Coromilas
- Department of Medicine, Division of Cardiovascular Disease and Hypertension, Rutgers University, New Brunswick, New Jersey
| | - Elaine Y Wan
- Department of Medicine, Division of Cardiology, Columbia University College of Physicians and Surgeons, New York, New York
| | - Hirad Yarmohammadi
- Department of Medicine, Division of Cardiology, Columbia University College of Physicians and Surgeons, New York, New York
| | - Andrew L Wit
- Department of Pharmacology, Columbia University College of Physicians and Surgeons, New York, New York
| | - Nicholas S Peters
- ElectroCardioMaths Programme, Imperial Centre for Cardiac Engineering, Imperial College London, London, United Kingdom
| | - Hasan Garan
- Department of Medicine, Division of Cardiology, Columbia University College of Physicians and Surgeons, New York, New York
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3
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Kim C, Park CH, Kim DY, Cha J, Lee BY, Park CH, Kang EJ, Koo HJ, Kitagawa K, Cha MJ, Krittayaphong R, Choi SI, Viswamitra S, Ko SM, Kim SM, Hwang SH, Trang NN, Lee W, Kim YJ, Lee J, Yang DH. Semi-Quantitative Scoring of Late Gadolinium Enhancement of the Left Ventricle in Patients with Ischemic Cardiomyopathy: Improving Interobserver Reliability and Agreement Using Consensus Guidance from the Asian Society of Cardiovascular Imaging-Practical Tutorial (ASCI-PT) 2020. Korean J Radiol 2022; 23:298-307. [PMID: 35213094 PMCID: PMC8876655 DOI: 10.3348/kjr.2021.0387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 10/13/2021] [Accepted: 10/18/2021] [Indexed: 11/27/2022] Open
Abstract
Objective This study aimed to evaluate the effect of implementing the consensus statement from the Asian Society of Cardiovascular Imaging-Practical Tutorial 2020 (ASCI-PT 2020) on the reliability of cardiac MR with late gadolinium enhancement (CMR-LGE) myocardial viability scoring between observers in the context of ischemic cardiomyopathy. Materials and Methods A total of 17 cardiovascular imaging experts from five different countries evaluated CMR obtained in 26 patients (male:female, 23:3; median age [interquartile range], 55.5 years [50–61.8]) with ischemic cardiomyopathy. For LGE scoring, based on the 17 segments, the extent of LGE in each segment was graded using a five-point scoring system ranging from 0 to 4 before and after exposure according to the consensus statement. All scoring was performed via web-based review. Scores for slices, vascular territories, and total scores were obtained as the sum of the relevant segmental scores. Interobserver reliability for segment scores was assessed using Fleiss’ kappa, while the intraclass correlation coefficient (ICC) was used for slice score, vascular territory score, and total score. Inter-observer agreement was assessed using the limits of agreement from the mean (LoA). Results Interobserver reliability (Fleiss’ kappa) in each segment ranged 0.242–0.662 before the consensus and increased to 0.301–0.774 after the consensus. The interobserver reliability (ICC) for each slice, each vascular territory, and total score increased after the consensus (slice, 0.728–0.805 and 0.849–0.884; vascular territory, 0.756–0.902 and 0.852–0.941; total score, 0.847 and 0.913, before and after implementing the consensus statement, respectively. Interobserver agreement in scoring also improved with the implementation of the consensus for all slices, vascular territories, and total score. The LoA for the total score narrowed from ± 10.36 points to ± 7.12 points. Conclusion The interobserver reliability and agreement for CMR-LGE scoring for ischemic cardiomyopathy improved when following guidance from the ASCI-PT 2020 consensus statement.
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Affiliation(s)
- Cherry Kim
- Department of Radiology, Korea University Ansan Hospital, Ansan, Korea
| | - Chul Hwan Park
- Department of Radiology and Research Institute of Radiological Science, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Do Yeon Kim
- Biomedical Research Center, Korea University Ansan Hospital, Ansan, Korea
| | - Jaehyung Cha
- Biomedical Research Center, Korea University Ansan Hospital, Ansan, Korea
| | - Bae Young Lee
- Department of Radiology, Eunpyeong St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
| | - Chan Ho Park
- Department of Radiology, Soonchunhyang University Cheonan Hospital, Cheonan, Korea
| | - Eun-Ju Kang
- Department of Radiology, College of Medicine, Dong-A University, Busan, Korea
| | - Hyun Jung Koo
- Department of Radiology and Research Institute of Radiology, Cardiac Imaging Center, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
| | - Kakuya Kitagawa
- Department of Radiology, Mie University Graduate School of Medicine, Tsu, Japan
| | - Min Jae Cha
- Department of Radiology, Chung-Ang University Hospital, Seoul, Korea
| | - Rungroj Krittayaphong
- Division of Cardiology, Department of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Sang Il Choi
- Department of Radiology, Seoul University Bundang Hospital, Seongnam, Korea
| | - Sanjaya Viswamitra
- Department of Radiology, Sri Sathya Sai Institute of Higher Medical Sciences, Karnataka, India
| | - Sung Min Ko
- Department of Radiology, Yonsei University Wonju College of Medicine, Wonju Severance Christian Hospital, Wonju, Korea
| | - Sung Mok Kim
- Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Sung Ho Hwang
- Department of Radiology, Korea University Anam Hospital, Seoul, Korea
| | - Nguyen Ngoc Trang
- Radiology Center, Bach Mai University Hospital, Hanoi, Vietnam , Korea
| | - Whal Lee
- Department of Radiology, Seoul University Hospital, Seoul, Korea
| | - Young Jin Kim
- Department of Radiology and Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Jongmin Lee
- Department of Radiology, Kyungpook National University Hospital, Daegu, Korea
| | - Dong Hyun Yang
- Department of Radiology and Research Institute of Radiology, Cardiac Imaging Center, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
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Zhu E, Zhang C, Wang S, Ma X, Lai Y. The association between myocardial scar and the response of moderate ischemic mitral regurgitation to isolated coronary artery bypass grafting. ANNALS OF TRANSLATIONAL MEDICINE 2021; 9:1328. [PMID: 34532465 PMCID: PMC8422129 DOI: 10.21037/atm-21-3622] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Accepted: 08/20/2021] [Indexed: 11/06/2022]
Abstract
Background The factors that associated with the response of moderate ischemic mitral regurgitation (IMR) to isolated coronary artery bypass grafting (CABG) remain unclear. This study aims to evaluate whether left ventricular (LV) myocardial scar assessed by cardiovascular magnetic resonance (CMR) is associated with the outcome of moderate IMR after isolated CABG. Methods Forty-six patients with coronary artery disease (CAD) and moderate IMR who underwent isolated CABG between January 2014 and February 2019 in Anzhen Hospital Affiliated to Capital Medical University were enrolled in this case-control study. All patients underwent CMR and echocardiography before surgery. Patients were classified into two groups according to the severity of IMR 1 year after CABG: an improved group (no or mild IMR) and an unimproved group (moderate or severe IMR). Univariate and multivariate logistic regression analyses were used to assess the association between individual variables and unimproved IMR at 1-year post-CABG. Results Compared to patients in the improved group, the patients in the unimproved group had a significantly greater amount of LV myocardial scar (18.0%±9.5% vs. 30.8%±11.2%, P<0.001). In the multiple logistic regression model, after adjustment for age, sex, and body mass index, only LV myocardial scar (OR: 0.89, 95% CI: 0.83–0.96, P=0.001) was independently associated with unimproved IMR after isolated CABG. Furthermore, there was no difference in the 3-year overall survival rates between the two groups (92.3% vs. 90.3%, P=0.46). In addition, patients in the unimproved group had a higher New York Heart Association (NYHA) classification (P=0.01) and more major adverse cardiac events such as MI, angina pectoris, and readmission for heart failure (P=0.03). Conclusions A greater amount of preoperative LV myocardial scar was associated with unimproved moderate IMR after isolated CABG. Measuring preoperative LV myocardial scar is helpful to predict post-operative outcome and determine optimal surgery in patients with moderate IMR.
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Affiliation(s)
- Enjun Zhu
- Department of Cardiovascular Surgery, Anzhen Hospital Affiliated to Capital Medical University, Beijing, China
| | - Chen Zhang
- Department of Radiology, Anzhen Hospital Affiliated to Capital Medical University, Beijing, China
| | - Shengwei Wang
- Department of Cardiovascular Surgery, Anzhen Hospital Affiliated to Capital Medical University, Beijing, China
| | - Xiaohai Ma
- Department of Interventional Diagnosis and Treatment, Anzhen Hospital Affiliated to Capital Medical University, Beijing, China
| | - Yongqiang Lai
- Department of Cardiovascular Surgery, Anzhen Hospital Affiliated to Capital Medical University, Beijing, China
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5
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Development and testing of a deep learning-based strategy for scar segmentation on CMR-LGE images. MAGNETIC RESONANCE MATERIALS IN PHYSICS BIOLOGY AND MEDICINE 2018; 32:187-195. [PMID: 30460430 DOI: 10.1007/s10334-018-0718-4] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 11/01/2018] [Accepted: 11/08/2018] [Indexed: 02/03/2023]
Abstract
OBJECTIVE The aim of this paper is to investigate the use of fully convolutional neural networks (FCNNs) to segment scar tissue in the left ventricle from cardiac magnetic resonance with late gadolinium enhancement (CMR-LGE) images. METHODS A successful FCNN in the literature (the ENet) was modified and trained to provide scar-tissue segmentation. Two segmentation protocols (Protocol 1 and Protocol 2) were investigated, the latter limiting the scar-segmentation search area to the left ventricular myocardial tissue region. CMR-LGE from 30 patients with ischemic-heart disease were retrospectively analyzed, for a total of 250 images, presenting high variability in terms of scar dimension and location. Segmentation results were assessed against manual scar-tissue tracing using one-patient-out cross validation. RESULTS Protocol 2 outperformed Protocol 1 significantly (p value < 0.05), with median sensitivity and Dice similarity coefficient equal to 88.07% [inter-quartile range (IQR) 18.84%] and 71.25% (IQR 31.82%), respectively. DISCUSSION Both segmentation protocols were able to detect scar tissues in the CMR-LGE images but higher performance was achieved when limiting the search area to the myocardial region. The findings of this paper represent an encouraging starting point for the use of FCNNs for the segmentation of nonviable scar tissue from CMR-LGE images.
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6
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Prospective evaluation of left atrial function and late gadolinium enhancement with 3 T MRI in patients with atrial fibrillation before and after catheter ablation. Int J Cardiovasc Imaging 2018; 35:499-504. [PMID: 30264364 DOI: 10.1007/s10554-018-1455-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Accepted: 09/17/2018] [Indexed: 10/28/2022]
Abstract
In a prospective, randomized study we performed left atrial (LA) functional imaging and late gadolinium enhancement (LGE) in patients undergoing pulmonary vein isolation with ablation of the anterior mitral line to evaluate LA function and visibility of the anterior mitral line and to explore the relationship of these factors to short- and long-term procedural success. Functional imaging of the LA and LGE-visualization 15 min post i.v. administration of gadobutrol was performed on a 3 T MRI system before and after ablation. Patients were grouped in (a) subjects with sinus rhythm, and (b) subjects without sinus rhythm at the follow-up-MRI. Eight patients were excluded due to poor image quality. 37 patients were allotted to group a, 4 patients to group b. Group a showed a significant improvement in ejection fraction (22.3 ± 7.1% vs. 27.2 ± 5.5%; p < 0.001), end-systolic volume (111.6 ± 48.3 ml vs. 96.9 ± 37.2 ml; p = 0.002), stroke volume (30.2 ± 12.6 ml vs. 35.6 ± 12.6 ml; p = 0.003) and LGE (12.5% vs. 83.7%; p < 0.001). Group b showed no significant changes in functional parameters or LGE. Patients with successful therapy at 12 months showed significantly lower volumes in the baseline MRI. Scarring along the ablation pathways could be visualized with LGE. Patients with successful CA showed a significant improvement in LA cardiac parameters. Pre-ablation atrial volume seems to be a predictor for long-term success.
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7
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Pontecorboli G, Figueras I Ventura RM, Carlosena A, Benito E, Prat-Gonzales S, Padeletti L, Mont L. Use of delayed-enhancement magnetic resonance imaging for fibrosis detection in the atria: a review. Europace 2018; 19:180-189. [PMID: 28172967 DOI: 10.1093/europace/euw053] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Accepted: 02/02/2016] [Indexed: 11/13/2022] Open
Abstract
This paper presents a review of the different approaches existing in the literature to detect and quantify fibrosis in contrast-enhanced magnetic resonance images of the left atrial wall. The paper provides a critical analysis of the different methods, stating their advantages and limitations, and providing detailed analysis on the possible sources of variability in the final amount of detected fibrosis coming from the use of different techniques.
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Affiliation(s)
| | | | | | - Eva Benito
- Hospital Clinic, Universitat de Barcelona, Catalonia, Spain
| | | | - Luigi Padeletti
- Department of Heart and Vessels, University of Florence, Florence, Italy.,IRCCS Multimedica, Milan, Italy
| | - Lluís Mont
- Hospital Clinic, Universitat de Barcelona, Catalonia, Spain
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8
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Berg J, Kottwitz J, Baltensperger N, Kissel CK, Lovrinovic M, Mehra T, Scherff F, Schmied C, Templin C, Lüscher TF, Heidecker B, Manka R. Cardiac Magnetic Resonance Imaging in Myocarditis Reveals Persistent Disease Activity Despite Normalization of Cardiac Enzymes and Inflammatory Parameters at 3-Month Follow-Up. Circ Heart Fail 2017; 10:CIRCHEARTFAILURE.117.004262. [PMID: 29158437 DOI: 10.1161/circheartfailure.117.004262] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 10/13/2017] [Indexed: 02/06/2023]
Abstract
BACKGROUND There is a major unmet need to identify high-risk patients in myocarditis. Although decreasing cardiac and inflammatory markers are commonly interpreted as resolving myocarditis, this assumption has not been confirmed as of today. We sought to evaluate whether routine laboratory parameters at diagnosis predict dynamic of late gadolinium enhancement (LGE) as persistent LGE has been shown to be a risk marker in myocarditis. METHODS AND RESULTS Myocarditis was diagnosed based on clinical presentation, high-sensitivity troponin T, and cardiac magnetic resonance imaging, after exclusion of obstructive coronary artery disease by angiography. Cardiac magnetic resonance imaging was repeated at 3 months. LGE extent was analyzed with the software GT Volume. Change in LGE >20% was considered significant. Investigated cardiac and inflammatory markers included high-sensitivity troponin T, creatine kinase, myoglobin, N-terminal B-type natriuretic peptide, C-reactive protein, and leukocyte count. Twenty-four patients were enrolled. Absolute levels of cardiac enzymes and inflammatory markers at baseline did not predict change in LGE at 3 months. Cardiac and inflammatory markers had normalized in 21 patients (88%). LGE significantly improved in 16 patients (67%); however, it persisted to a lesser degree in 17 of them (71%) and increased in a small percentage (21%) despite normalization of cardiac enzymes. CONCLUSIONS This is the first study reporting that cardiac enzymes and inflammatory parameters do not sufficiently reflect LGE in myocarditis. Although a majority of patients with normalizing laboratory markers experienced improved LGE, in a small percentage LGE worsened. These data suggest that cardiac magnetic resonance imaging might add value to currently existing diagnostic tools for risk assessment in myocarditis.
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Affiliation(s)
- Jan Berg
- From the Division of Cardiology, University Hospital of Zurich, Switzerland
| | - Jan Kottwitz
- From the Division of Cardiology, University Hospital of Zurich, Switzerland
| | - Nora Baltensperger
- From the Division of Cardiology, University Hospital of Zurich, Switzerland
| | - Christine K Kissel
- From the Division of Cardiology, University Hospital of Zurich, Switzerland
| | - Marina Lovrinovic
- From the Division of Cardiology, University Hospital of Zurich, Switzerland
| | - Tarun Mehra
- From the Division of Cardiology, University Hospital of Zurich, Switzerland
| | - Frank Scherff
- From the Division of Cardiology, University Hospital of Zurich, Switzerland
| | - Christian Schmied
- From the Division of Cardiology, University Hospital of Zurich, Switzerland
| | - Christian Templin
- From the Division of Cardiology, University Hospital of Zurich, Switzerland
| | - Thomas F Lüscher
- From the Division of Cardiology, University Hospital of Zurich, Switzerland
| | - Bettina Heidecker
- From the Division of Cardiology, University Hospital of Zurich, Switzerland.
| | - Robert Manka
- From the Division of Cardiology, University Hospital of Zurich, Switzerland
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9
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Kusunose K, Obuchowski NA, Gillinov M, Popovic ZB, Flamm SD, Griffin BP, Kwon DH. Predictors of Mortality in Patients With Severe Ischemic Cardiomyopathy Undergoing Surgical Mitral Valve Intervention. J Am Heart Assoc 2017; 6:JAHA.117.007163. [PMID: 29150492 PMCID: PMC5721789 DOI: 10.1161/jaha.117.007163] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Background Ischemic mitral regurgitation is associated with substantial risk of death. Although surgical mitral valve intervention (MVi) may improve symptoms, it has not been shown to improve survival. The aim of this study was to identify predictors of mortality in patients with ischemic mitral regurgitation and MVi. Methods and Results We evaluated 117 consecutive patients (age, 65±10 years) with advanced ischemic cardiomyopathy who underwent cardiac magnetic resonance and subsequent MVi between January 1, 2002 and January 1, 2012. Cardiac magnetic resonance was used to assess left ventricular remodeling and myocardial scarring. The effective regurgitant orifice area was calculated from the proximal isovelocity surface area by echocardiography. There were 43 deaths (37%) during follow‐up (median, 62 months). On multivariable analysis, age ≥70 years (P=0.013), diabetes mellitus (P=0.001), dyslipidemia (P=0.012), papillary muscle scar (P=0.010), incomplete revascularization (P=0.001), and total scar %×effective regurgitant orifice area ≥0.20 cm2 (P=0.005) were each independently associated with all‐cause mortality. Although patients with effective regurgitant orifice area <0.2 cm2 at baseline demonstrated an increased hazard ratio of 3.3 for every 10% increase in scar, the hazard ratio increased to 9 for every 10% increase in scar in those with baseline effective regurgitant orifice area ≥0.20 cm2. Mortality also was significantly higher in patients with incomplete revascularization compared with those with vascularized viable myocardium (61% versus 28%; P<0.001). Conclusions Increased total scar burden and the presence of incomplete revascularization are powerful predictors of mortality in patients with advanced ischemic cardiomyopathy undergoing MVi. Viability assessment with cardiac magnetic resonance imaging can identify which patients with ischemic mitral regurgitation are at highest risk for mortality after surgical MVi.
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Affiliation(s)
- Kenya Kusunose
- Heart and Vascular Institute, Cleveland Clinic, Cleveland, OH.,Cardiovascular Medicine, Tokushima University Hospital, Tokushima, Japan
| | - Nancy A Obuchowski
- Imaging Institute, Cleveland Clinic, Cleveland, OH.,Quantitative Health Sciences, Cleveland Clinic, Cleveland, OH
| | - Marc Gillinov
- Heart and Vascular Institute, Cleveland Clinic, Cleveland, OH
| | - Zoran B Popovic
- Heart and Vascular Institute, Cleveland Clinic, Cleveland, OH.,Imaging Institute, Cleveland Clinic, Cleveland, OH
| | - Scott D Flamm
- Heart and Vascular Institute, Cleveland Clinic, Cleveland, OH.,Imaging Institute, Cleveland Clinic, Cleveland, OH
| | - Brian P Griffin
- Heart and Vascular Institute, Cleveland Clinic, Cleveland, OH
| | - Deborah H Kwon
- Heart and Vascular Institute, Cleveland Clinic, Cleveland, OH .,Imaging Institute, Cleveland Clinic, Cleveland, OH
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10
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Abstract
In the last twenty years, new imaging techniques to assess atrial function and to predict the risk of recurrence of atrial fibrillation after treatment have been developed. The present review deals with the role of these techniques in the detection of structural and functional changes of the atrium and diagnosis of atrial remodeling, particularly atrial fibrosis. Echocardiography allows the detection of anatomical, functional changes and deformation of the atrial wall during the phases of the cardiac cycle. For this, adequate acquisition of atrial images is necessary using speckle tracking imaging and interpretation of the resulting strain and strain rate curves. This allows to predict new-onset atrial fibrillation and recurrences. Its main limitations are inter-observer variability, the existence of different software manufacturers, and the fact that the software used were originally developed for the evaluation of the ventricular function and are now applied to the atria. Cardiac magnetic resonance, using contrast enhancement with gadolinium, plays a key role in the visualization and quantification of atrial fibrosis. This is the established method for in vivo visualization of myocardial fibrotic tissue. The non-invasive evaluation of atrial fibrosis is associated with the risk of recurrence of atrial fibrillation and with electro-anatomical endocardial mapping. We discuss the limitations of these techniques, derived from the difficulty of demonstrating the correlation between fibrosis imaging and histology, and poor intra- and inter-observer reproducibility. The sources of discordance are described, mainly due to image acquisition and processing, and the challenges ahead in an attempt to eliminate differences between operators.
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11
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Connolly AJ, Bishop MJ. Computational Representations of Myocardial Infarct Scars and Implications for Arrhythmogenesis. CLINICAL MEDICINE INSIGHTS-CARDIOLOGY 2016; 10:27-40. [PMID: 27486348 PMCID: PMC4962962 DOI: 10.4137/cmc.s39708] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Revised: 05/17/2016] [Accepted: 05/27/2016] [Indexed: 11/30/2022]
Abstract
Image-based computational modeling is becoming an increasingly used clinical tool to provide insight into the mechanisms of reentrant arrhythmias. In the context of ischemic heart disease, faithful representation of the electrophysiological properties of the infarct region within models is essential, due to the scars known for arrhythmic properties. Here, we review the different computational representations of the infarcted region, summarizing the experimental measurements upon which they are based. We then focus on the two most common representations of the scar core (complete insulator or electrically passive tissue) and perform simulations of electrical propagation around idealized infarct geometries. Our simulations highlight significant differences in action potential duration and focal effective refractory period (ERP) around the scar, driven by differences in electrotonic loading, depending on the choice of scar representation. Finally, a novel mechanism for arrhythmia induction, following a focal ectopic beat, is demonstrated, which relies on localized gradients in ERP directly caused by the electrotonic sink effects of the neighboring passive scar.
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Affiliation(s)
- Adam J Connolly
- Department of Imaging Sciences and Bioengineering, King's College London, St Thomas' Hospital, London, UK
| | - Martin J Bishop
- Department of Imaging Sciences and Bioengineering, King's College London, St Thomas' Hospital, London, UK
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12
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Kwon DH, Kusunose K, Obuchowski NA, Cavalcante JL, Popovic ZB, Thomas JD, Desai MY, Flamm SD, Griffin BP. Predictors and Prognostic Impact of Progressive Ischemic Mitral Regurgitation in Patients With Advanced Ischemic Cardiomyopathy. Circ Cardiovasc Imaging 2016; 9:CIRCIMAGING.115.004577. [DOI: 10.1161/circimaging.115.004577] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Accepted: 05/04/2016] [Indexed: 02/04/2023]
Abstract
Background—
Ischemic mitral regurgitation (IMR) is associated with poor outcomes. It is unknown what factors contribute to progression of IMR and how progressive IMR affects outcomes. We sought to determine imaging predictors of IMR progression and to determine if progressive IMR is an independent predictor of survival in patients with advanced ischemic cardiomyopathy.
Methods and Results—
Consecutive advanced ischemic cardiomyopathy patients who underwent cardiac magnetic resonance and echocardiograms at baseline with echocardiographic follow-up were studied. Cardiac magnetic resonance was used to assess left ventricular volumes, infarct size, and mitral valve geometry. The effective regurgitant orifice area (EROA) was calculated from the proximal isovelocity surface area by echocardiography. Repeated measures mixed effects and Cox proportional hazards regression models were built to identify predictors of IMR progression and survival. We evaluated 336 patients (age, 62±11 years) over a median follow-up time of 54 months: 154 patients were subsequently revascularized, and 182 patients were medically treated. Ninety-eight patients (29%) demonstrated an increase in EROA values of ≥0.1 cm
2
. There were 87 adverse events (death or transplant). On multivariable analysis, infarct size (
P
<0.001), progression in IMR (
P
=0.008), age (
P
=0.003), and baseline EROA (
P
=0.010) were independently associated with adverse events. Independent predictors of IMR progression were as follows: baseline EROA (
P
<0.001), left ventricular end–systolic volume index (
P
=0.014), and total scar (
P
=0.036).
Conclusions—
IMR frequently increases in severity, and progression is independently associated with adverse left ventricular remodeling and infarct size, as assessed by cardiac magnetic resonance. Furthermore, IMR progression is a powerful independent predictor of adverse events, even after controlling for the severity of IMR at baseline.
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Affiliation(s)
- Deborah H. Kwon
- From the Department of Cardiology, Heart and Vascular Institute (D.H.K., K.K., Z.B.P., M.Y.D., S.D.F., B.P.G.), Imaging Institute (D.H.K., M.Y.D., S.D.F.), and Quantitative Health Sciences (N.A.O.), Cleveland Clinic, OH; Cardiovascular Medicine, Tokushima University Hospital, Japan (K.K.); Division of Cardiology, Department of Medicine, Heart and Vascular Institute, University of Pittsburgh/University of Pittsburgh Medical Center, PA (J.L.C.); Heart and Vascular Institute, Northwestern University
| | - Kenya Kusunose
- From the Department of Cardiology, Heart and Vascular Institute (D.H.K., K.K., Z.B.P., M.Y.D., S.D.F., B.P.G.), Imaging Institute (D.H.K., M.Y.D., S.D.F.), and Quantitative Health Sciences (N.A.O.), Cleveland Clinic, OH; Cardiovascular Medicine, Tokushima University Hospital, Japan (K.K.); Division of Cardiology, Department of Medicine, Heart and Vascular Institute, University of Pittsburgh/University of Pittsburgh Medical Center, PA (J.L.C.); Heart and Vascular Institute, Northwestern University
| | - Nancy A. Obuchowski
- From the Department of Cardiology, Heart and Vascular Institute (D.H.K., K.K., Z.B.P., M.Y.D., S.D.F., B.P.G.), Imaging Institute (D.H.K., M.Y.D., S.D.F.), and Quantitative Health Sciences (N.A.O.), Cleveland Clinic, OH; Cardiovascular Medicine, Tokushima University Hospital, Japan (K.K.); Division of Cardiology, Department of Medicine, Heart and Vascular Institute, University of Pittsburgh/University of Pittsburgh Medical Center, PA (J.L.C.); Heart and Vascular Institute, Northwestern University
| | - João L. Cavalcante
- From the Department of Cardiology, Heart and Vascular Institute (D.H.K., K.K., Z.B.P., M.Y.D., S.D.F., B.P.G.), Imaging Institute (D.H.K., M.Y.D., S.D.F.), and Quantitative Health Sciences (N.A.O.), Cleveland Clinic, OH; Cardiovascular Medicine, Tokushima University Hospital, Japan (K.K.); Division of Cardiology, Department of Medicine, Heart and Vascular Institute, University of Pittsburgh/University of Pittsburgh Medical Center, PA (J.L.C.); Heart and Vascular Institute, Northwestern University
| | - Zoran B. Popovic
- From the Department of Cardiology, Heart and Vascular Institute (D.H.K., K.K., Z.B.P., M.Y.D., S.D.F., B.P.G.), Imaging Institute (D.H.K., M.Y.D., S.D.F.), and Quantitative Health Sciences (N.A.O.), Cleveland Clinic, OH; Cardiovascular Medicine, Tokushima University Hospital, Japan (K.K.); Division of Cardiology, Department of Medicine, Heart and Vascular Institute, University of Pittsburgh/University of Pittsburgh Medical Center, PA (J.L.C.); Heart and Vascular Institute, Northwestern University
| | - James D. Thomas
- From the Department of Cardiology, Heart and Vascular Institute (D.H.K., K.K., Z.B.P., M.Y.D., S.D.F., B.P.G.), Imaging Institute (D.H.K., M.Y.D., S.D.F.), and Quantitative Health Sciences (N.A.O.), Cleveland Clinic, OH; Cardiovascular Medicine, Tokushima University Hospital, Japan (K.K.); Division of Cardiology, Department of Medicine, Heart and Vascular Institute, University of Pittsburgh/University of Pittsburgh Medical Center, PA (J.L.C.); Heart and Vascular Institute, Northwestern University
| | - Milind Y. Desai
- From the Department of Cardiology, Heart and Vascular Institute (D.H.K., K.K., Z.B.P., M.Y.D., S.D.F., B.P.G.), Imaging Institute (D.H.K., M.Y.D., S.D.F.), and Quantitative Health Sciences (N.A.O.), Cleveland Clinic, OH; Cardiovascular Medicine, Tokushima University Hospital, Japan (K.K.); Division of Cardiology, Department of Medicine, Heart and Vascular Institute, University of Pittsburgh/University of Pittsburgh Medical Center, PA (J.L.C.); Heart and Vascular Institute, Northwestern University
| | - Scott D. Flamm
- From the Department of Cardiology, Heart and Vascular Institute (D.H.K., K.K., Z.B.P., M.Y.D., S.D.F., B.P.G.), Imaging Institute (D.H.K., M.Y.D., S.D.F.), and Quantitative Health Sciences (N.A.O.), Cleveland Clinic, OH; Cardiovascular Medicine, Tokushima University Hospital, Japan (K.K.); Division of Cardiology, Department of Medicine, Heart and Vascular Institute, University of Pittsburgh/University of Pittsburgh Medical Center, PA (J.L.C.); Heart and Vascular Institute, Northwestern University
| | - Brian P. Griffin
- From the Department of Cardiology, Heart and Vascular Institute (D.H.K., K.K., Z.B.P., M.Y.D., S.D.F., B.P.G.), Imaging Institute (D.H.K., M.Y.D., S.D.F.), and Quantitative Health Sciences (N.A.O.), Cleveland Clinic, OH; Cardiovascular Medicine, Tokushima University Hospital, Japan (K.K.); Division of Cardiology, Department of Medicine, Heart and Vascular Institute, University of Pittsburgh/University of Pittsburgh Medical Center, PA (J.L.C.); Heart and Vascular Institute, Northwestern University
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13
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Comparison of Image Processing Techniques for Nonviable Tissue Quantification in Late Gadolinium Enhancement Cardiac Magnetic Resonance Images. J Thorac Imaging 2016; 31:168-76. [DOI: 10.1097/rti.0000000000000206] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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14
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Beliveau P, Cheriet F, Anderson SA, Taylor JL, Arai AE, Hsu LY. Quantitative assessment of myocardial fibrosis in an age-related rat model by ex vivo late gadolinium enhancement magnetic resonance imaging with histopathological correlation. Comput Biol Med 2015; 65:103-13. [PMID: 26313531 DOI: 10.1016/j.compbiomed.2015.07.027] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Revised: 07/28/2015] [Accepted: 07/29/2015] [Indexed: 10/23/2022]
Abstract
Late gadolinium enhanced (LGE) cardiac magnetic resonance (CMR) imaging can detect the presence of myocardial infarction from ischemic cardiomyopathies (ICM). However, it is more challenging to detect diffuse myocardial fibrosis from non-ischemic cardiomyopathy (NICM) with this technique due to more subtle and heterogeneous enhancement of the myocardium. This study investigates whether high-resolution LGE CMR can detect age-related myocardial fibrosis using quantitative texture analysis with histological validation. LGE CMR of twenty-four rat hearts (twelve 6-week-old and twelve 2-year-old) was performed using a 7T MRI scanner. Picrosirius red was used as the histopathology reference for collagen staining. Fibrosis in the myocardium was quantified with standard deviation (SD) threshold methods from the LGE CMR images and 3D contrast texture maps that were computed from gray level co-occurrence matrix of the CMR images. There was a significant increase of collagen fibers in the aged compared to the young rat histology slices (2.60±0.27 %LV vs. 1.24±0.29 %LV, p<0.01). Both LGE CMR and texture images showed a significant increase of myocardial fibrosis in the elderly compared to the young rats. Fibrosis in the LGE CMR images correlated strongly with histology with the 3 SD threshold (r=0.84, y=0.99x+0.00). Similarly, fibrosis in the contrast texture maps correlated with the histology using the 4 SD threshold (r=0.89, y=1.01x+0.00). High resolution ex-vivo LGE CMR can detect the presence of diffuse fibrosis that naturally developed in elderly rat hearts. Our results suggest that texture analysis may improve the assessment of myocardial fibrosis in LGE CMR images.
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Affiliation(s)
- Pascale Beliveau
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA; Institute of Biomedical Engineering, Ecole Polytechnique of Montreal, Montreal, Canada
| | - Farida Cheriet
- Institute of Biomedical Engineering, Ecole Polytechnique of Montreal, Montreal, Canada
| | - Stasia A Anderson
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Joni L Taylor
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Andrew E Arai
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Li-Yueh Hsu
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA.
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15
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Is there a role for diastolic function assessment in era of delayed enhancement cardiac magnetic resonance imaging?: a multimodality imaging study in patients with advanced ischemic cardiomyopathy. Am Heart J 2014; 168:220-8.e1. [PMID: 25066562 DOI: 10.1016/j.ahj.2014.04.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Accepted: 04/05/2014] [Indexed: 11/22/2022]
Abstract
UNLABELLED Cardiac magnetic resonance (CMR) identifies important prognostic variables in ischemic cardiomyopathy (ICM) patients such as left ventricular (LV) volumes, LV ejection fraction (LVEF), peri-infarct zone, and myocardial scar burden (MSB). It is unknown whether Doppler-based diastolic dysfunction (DDF) retains its prognostic value in ICM patients, in the context of current imaging, medical, and device therapies. METHODS Diastolic function was evaluated in ICM patients (LVEF ≤ 40% and ≥ 70% stenosis in ≥ 1 coronary artery) who underwent transthoracic echocardiogram and delayed hyperenhancement CMR studies within 7 days. The association of DDF with the combined end point was assessed after risk-adjustment using Cox proportional hazards models. RESULTS A total of 360 patients with severe LV dysfunction (LVEF = 24 ± 9%) and extensive MSB (31 ± 17%) were evaluated; DDF was present in all patients (stage 1%-44%, stage 2%-25%, stage 3%-31%). There were 130 events (124 deaths and 6 heart transplants) over a median follow-up of 5.8 years (IQR, 3.7-7.4 years). On multivariable analysis, DDF > stage 1 (HR, 1.37; P = .007) was associated with the combined end-point, independent of clinical risk score (HR, 2.40; P < .0001), implantable cardioverter defibrillator implantation (HR, 0.60; P = .009), incomplete revascularization (HR, 1.32; P = .003), mitral regurgitation (HR, 3.37; P = .01), peri-infarct zone area (HR, 1.04; P = 0.02), and MSB (HR, 1.02; P = .01). DDF had incremental prognostic value for the combined end-point (model χ(2) increased from 89 to 95, P = .02). CONCLUSION DDF is a powerful predictor of mortality in ICM patients with significant LV dysfunction, independent of clinical and CMR data. DDF assessment provides incremental value, improving risk stratification.
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16
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Novel MRI and CT Approaches for the Characterization of Myocardial Infarct. CURRENT RADIOLOGY REPORTS 2013. [DOI: 10.1007/s40134-013-0027-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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17
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Gao H, Kadir K, Payne AR, Soraghan J, Berry C. Highly automatic quantification of myocardial oedema in patients with acute myocardial infarction using bright blood T2-weighted CMR. J Cardiovasc Magn Reson 2013; 15:28. [PMID: 23548176 PMCID: PMC3621376 DOI: 10.1186/1532-429x-15-28] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Accepted: 03/18/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND T2-weighted cardiovascular magnetic resonance (CMR) is clinically-useful for imaging the ischemic area-at-risk and amount of salvageable myocardium in patients with acute myocardial infarction (MI). However, to date, quantification of oedema is user-defined and potentially subjective. METHODS We describe a highly automatic framework for quantifying myocardial oedema from bright blood T2-weighted CMR in patients with acute MI. Our approach retains user input (i.e. clinical judgment) to confirm the presence of oedema on an image which is then subjected to an automatic analysis. The new method was tested on 25 consecutive acute MI patients who had a CMR within 48 hours of hospital admission. Left ventricular wall boundaries were delineated automatically by variational level set methods followed by automatic detection of myocardial oedema by fitting a Rayleigh-Gaussian mixture statistical model. These data were compared with results from manual segmentation of the left ventricular wall and oedema, the current standard approach. RESULTS The mean perpendicular distances between automatically detected left ventricular boundaries and corresponding manual delineated boundaries were in the range of 1-2 mm. Dice similarity coefficients for agreement (0=no agreement, 1=perfect agreement) between manual delineation and automatic segmentation of the left ventricular wall boundaries and oedema regions were 0.86 and 0.74, respectively. CONCLUSION Compared to standard manual approaches, the new highly automatic method for estimating myocardial oedema is accurate and straightforward. It has potential as a generic software tool for physicians to use in clinical practice.
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Affiliation(s)
- Hao Gao
- School of Mathematics and Statistics, University of Glasgow, Glasgow, G12 8QW, UK
| | - Kushsairy Kadir
- Centre for Excellence in Signal and Image Processing, Department of Electrical Engineering, University of Strathclyde, Glasgow, G1 1XW, UK
| | - Alexander R Payne
- BHF Glasgow Cardiovascular Research Centre, University of Glasgow, Glasgow, G12 8TA, UK
| | - John Soraghan
- Centre for Excellence in Signal and Image Processing, Department of Electrical Engineering, University of Strathclyde, Glasgow, G1 1XW, UK
| | - Colin Berry
- BHF Glasgow Cardiovascular Research Centre, University of Glasgow, Glasgow, G12 8TA, UK
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18
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Sasaki T, Miller CF, Hansford R, Yang J, Caffo BS, Zviman MM, Henrikson CA, Marine JE, Spragg D, Cheng A, Tandri H, Sinha S, Kolandaivelu A, Zimmerman SL, Bluemke DA, Tomaselli GF, Berger RD, Calkins H, Halperin HR, Nazarian S. Myocardial structural associations with local electrograms: a study of postinfarct ventricular tachycardia pathophysiology and magnetic resonance-based noninvasive mapping. Circ Arrhythm Electrophysiol 2012; 5:1081-90. [PMID: 23149263 DOI: 10.1161/circep.112.970699] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND The association of scar on late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) with local electrograms on electroanatomic mapping has been investigated. We aimed to quantify these associations to gain insights regarding LGE-CMR image characteristics of tissues and critical sites that support postinfarct ventricular tachycardia (VT). METHODS AND RESULTS LGE-CMR was performed in 23 patients with ischemic cardiomyopathy before VT ablation. Left ventricular wall thickness and postinfarct scar thickness were measured in each of 20 sectors per LGE-CMR short-axis plane. Electroanatomic mapping points were retrospectively registered to the corresponding LGE-CMR images. Multivariable regression analysis, clustered by patient, revealed significant associations among left ventricular wall thickness, postinfarct scar thickness, and intramural scar location on LGE-CMR, and local endocardial electrogram bipolar/unipolar voltage, duration, and deflections on electroanatomic mapping. Anteroposterior and septal/lateral scar localization was also associated with bipolar and unipolar voltage. Antiarrhythmic drug use was associated with electrogram duration. Critical sites of postinfarct VT were associated with >25% scar transmurality, and slow conduction sites with >40 ms stimulus-QRS time were associated with >75% scar transmurality. CONCLUSIONS Critical sites for maintenance of postinfarct VT are confined to areas with >25% scar transmurality. Our data provide insights into the structural substrates for delayed conduction and VT and may reduce procedural time devoted to substrate mapping, overcome limitations of invasive mapping because of sampling density, and enhance magnetic resonance-based ablation by feature extraction from complex images.
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Affiliation(s)
- Takeshi Sasaki
- Department of Medicine/Cardiology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA.
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19
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Kwon DH, Hachamovitch R, Popovic ZB, Starling RC, Desai MY, Flamm SD, Lytle BW, Marwick TH. Survival in Patients With Severe Ischemic Cardiomyopathy Undergoing Revascularization Versus Medical Therapy: Association With End-Systolic Volume and Viability. Circulation 2012; 126:S3-8. [DOI: 10.1161/circulationaha.111.084434] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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20
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New automated Markov-Gibbs random field based framework for myocardial wall viability quantification on agent enhanced cardiac magnetic resonance images. Int J Cardiovasc Imaging 2011; 28:1683-98. [PMID: 22160668 DOI: 10.1007/s10554-011-9991-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2011] [Accepted: 11/29/2011] [Indexed: 10/14/2022]
Abstract
A novel automated framework for detecting and quantifying viability from agent enhanced cardiac magnetic resonance images is proposed. The framework identifies the pathological tissues based on a joint Markov-Gibbs random field (MGRF) model that accounts for the 1st-order visual appearance of the myocardial wall (in terms of the pixel-wise intensities) and the 2nd-order spatial interactions between pixels. The pathological tissue is quantified based on two metrics: the percentage area in each segment with respect to the total area of the segment, and the trans-wall extent of the pathological tissue. This transmural extent is estimated using point-to-point correspondences based on a Laplace partial differential equation. Transmural extent was validated using a simulated phantom. We tested the proposed framework on 14 datasets (168 images) and validated against manual expert delineation of the pathological tissue by two observers. Mean Dice similarity coefficients (DSC) of 0.90 and 0.88 were obtained for the observers, approaching the ideal value, 1. The Bland-Altman statistic of infarct volumes estimated by manual versus the MGRF estimation revealed little bias difference, and most values fell within the 95% confidence interval, suggesting very good agreement. Using the DSC measure we documented statistically significant superior segmentation performance for our MGRF method versus established intensity-based methods (greater DSC, and smaller standard deviation). Our Laplace method showed good operating characteristics across the full range of extent of transmural infarct, outperforming conventional methods. Phantom validation and experiments on patient data confirmed the robustness and accuracy of the proposed framework.
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21
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Gruszczynska K, Kirschbaum S, Baks T, Moelker A, Duncker DJ, Rossi A, Baron J, de Feyter PJ, Krestin GP, van Geuns RJM. Different algorithms for quantitative analysis of myocardial infarction with DE MRI: comparison with autopsy specimen measurements. Acad Radiol 2011; 18:1529-36. [PMID: 22055796 DOI: 10.1016/j.acra.2011.08.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2010] [Revised: 08/08/2011] [Accepted: 08/09/2011] [Indexed: 11/15/2022]
Abstract
RATIONALE AND OBJECTIVES To compare two semiautomated methods for measurement of infarcted myocardium area on delayed contrast enhanced magnetic resonance imaging, with histopathology findings as standard of reference. MATERIALS AND METHODS Percentage area of myocardial infarction was measured in 10 Yorkshire landrace pigs manually and using two semiautomated methods. The first (standard deviation method) used two operator-selected regions of interest (ROIs) and nine different cutoff values (one to nine times the standard deviation of signal intensity in normal myocardium) to identify infarction. The second (threshold method) used threshold values based on percentages of maximum signal intensity to identify infarction. Results were compared with histopathology findings. RESULTS Difference between percentage area of infarction obtained with standard deviation method and autopsy specimens was in the range: -13.5% to +13.2%. With threshold method (thresholds from 30% to 90% of signal intensity), difference was -15% to +23%. Manual contouring underestimated infarcted area by 2% comparing to autopsy results. The best agreement between histopathology and semi-automated software was achieved for 4 standard deviations with standard deviation method: difference -0.45%, and for a percentage threshold of 70% (difference +0.67%) with threshold method. However, with standard deviation method, there was statistically significant difference between ROIs based on their location in viable myocardium: mean difference 1.7 ± 4%, P < .0001. CONCLUSION Semiautomated measurement of myocardial infarcted area on delayed enhanced magnetic resonance images performs well compared to autopsy. The threshold method, based on percentages of maximum signal intensity is preferable over standard deviation method, which is more susceptible to variability from location of ROIs within viable myocardium.
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Affiliation(s)
- Katarzyna Gruszczynska
- Department of Radiology, Erasmus MC, Universitair Medisch Centrum, Thoraxcenter, Ba 585, 's-Gravendijkwal 230, 3015 CE Rotterdam, the Netherlands
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22
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Viallon M, Jacquier A, Rotaru C, Delattre BMA, Mewton N, Vincent F, Croisille P. Head-to-head comparison of eight late gadolinium-enhanced cardiac MR (LGE CMR) sequences at 1.5 tesla: from bench to bedside. J Magn Reson Imaging 2011; 34:1374-87. [PMID: 21972032 DOI: 10.1002/jmri.22783] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2011] [Accepted: 07/28/2011] [Indexed: 11/10/2022] Open
Abstract
PURPOSE To compare-theoretically and experimentally-clinically available two-dimensional/three-dimensional (2D/3D), breathhold and non-breathhold, inversion-recovery (IR) gradient-echo (GRE) sequences used to differentiate between nonviable injured and normal myocardium with late gadolinium-enhanced techniques (IR-GRE2D sequence is used as a reference), and to evaluate their respective clinical benefit. MATERIALS AND METHODS Six breathhold (2D-IR-GRE, 3D-IR-GRE, balanced steady-state free precession 2D-IR-bSSFP and 3D-IR-bSSFP, phase-sensitive 2D-PSIR-GRE, and 2D-PSIR-bSSFP) and two non-breathhold late gadolinium-enhanced techniques (single-shot 2D-ssbSSFP and 2D-PSIR-ssbSSFP) were consecutively performed in 32 coronary artery disease patients with chronic myocardial infarction. Qualitative assessment and manual planimetry were performed by two independent observers. Quantitative assessment was based on percentage signal intensity elevation between injured and normal myocardium and contrast-to-noise ratio. Theoretical simulations were compared with experimental measurements performed on phantoms with various concentrations of gadolinium. RESULTS The 3D-IR-GRE image quality appeared better than the other 2D and 3D sequences, showing better delineation of complex nontransmural lesions, with significantly higher percentage signal intensity and contrast-to-noise ratio. PSIR techniques appeared more limited in differentiating sub-endocardial lesions and intracavity blood pool, but in all other cases were comparable to the other techniques. Single-shot PSIR-ssbSSFP appeared to be a valuable alternative technique when breathhold cannot be achieved. CONCLUSION We recommend 3D-IR-GRE as the method of choice for late gadolinium-enhanced cardiac magnetic resonance imaging in clinical practice.
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23
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Kirschner R, Varga-Szemes A, Brott BC, Litovsky S, Elgavish A, Elgavish GA, Simor T. Quantification of myocardial viability distribution with Gd(DTPA) bolus-enhanced, signal intensity-based percent infarct mapping. Magn Reson Imaging 2011; 29:650-8. [PMID: 21546192 DOI: 10.1016/j.mri.2011.02.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2010] [Accepted: 02/21/2011] [Indexed: 11/17/2022]
Abstract
INTRODUCTION A substantial, common shortcoming of the currently used semiautomated techniques for the quantification of myocardial infarct with delayed enhancement magnetic resonance imaging is the assumption that the whole myocardial slab that corresponds to the hyperenhanced tomographic area is 100% nonviable. This assumption is, however, incorrect. To resolve this conflict, we have recently proposed the signal intensity percent-infarct mapping method and validated it in an ex vivo, canine experiment. The purpose of the current study has been the validation of the signal intensity percent-infarct mapping method in vivo, using a porcine model of reperfused myocardial infarct. METHODS In swines (n=6), reperfused myocardial infarct was generated occluding for 90 min by an angioplasty balloon either the left anterior descending or the left circumflex coronary artery. To obtain DE images, Gd(DTPA) enhanced inversion-recovery fast gradient-echo acquisitions were carried out on day 28 after myocardial infarction. Scanning started 15 min after intravenous injection of 0.2 mmol/kg Gd(DTPA). At the end of the MRI session, the animal was sacrificed and 2,3,5-triphenyltetrazolium chloride staining was used to validate the existence and to determine the accurate size of the myocardial infarct. Tissue samples were taken and stained with hematoxylin-eosin and Masson's trichrome for histological assessment of the infarct and the periinfarct zone. The signal intensity percent-infarct mapping data were compared with corresponding data from the delayed enhancement images analyzed with SI(remote+2S.D.) thresholding, and with corresponding triphenyltetrazolium-chloride staining data using Friedman's repeated measure analysis of variance on ranks. RESULTS The infarct volume determined by the triphenyltetrazolium chloride, SI(remote+2S.D.) and signal intensity percent-infarct mapping methods was 3.04 ml [2.74, 3.45], 13.62 ml [9.06, 18.45] and 4.27 ml [3.45, 6.33], respectively. Median infarct volume determined by SI(remote+2S.D.) significantly differed from that determined by triphenyltetrazolium chloride (P<.05). The Bland-Altman overall bias was 12.49% of the volume of the left ventricle. Median infarct volume determined by signal intensity percent-infarct mapping, however, did not differ significantly (NS) from that obtained by triphenyltetrazolium chloride. Signal intensity percent-infarct mapping yielded only a 1.99% Bland-Altman overall bias of the left ventricular volume. CONCLUSIONS This in vivo study in the porcine reperfused myocardial infarct model demonstrates that signal intensity percent-infarct mapping is a highly accurate method for the determination of the extent of myocardial infarct. MRI images for signal intensity percent-infarct mapping are obtained with the pulse sequence of conventional delayed enhancement imaging and are acquired within clinically acceptable scanning time. This makes signal intensity percent-infarct mapping a practical method for clinical implementation.
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Affiliation(s)
- Robert Kirschner
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL 35294-0005, USA
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24
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Johnstone RI, Greenwood JP, Biglands JD, Plein S, Ridgway JP, Radjenovic A. Assessment of tissue edema in patients with acute myocardial infarction by computer-assisted quantification of triple inversion recovery prepared MRI of the myocardium. Magn Reson Med 2011; 66:564-73. [PMID: 21394767 DOI: 10.1002/mrm.22812] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2010] [Revised: 12/07/2010] [Accepted: 12/12/2010] [Indexed: 01/26/2023]
Abstract
The aim of this study was to design a computer algorithm to assess the extent of cardiac edema from triple inversion recovery MR images of the human left ventricular myocardium. Twenty-one patients presenting with acute myocardial infarction were scanned within 48 h of the onset of symptoms. Eight patients were scanned a second time, 4 weeks after the initial event. Myocardial edema was detected in 27 of 29 studies using visual contour-based manual segmentation. A reference standard, created from the segmentations of three raters by voxel-wise majority voting, was compared to the edema mass estimates obtained using a newly developed computer algorithm. At baseline (n=20), the reference standard yielded an edema mass of 16.4±15.0 g (mean±SD) and the computer algorithm edema mass was 16.4±12.6 g. At follow-up (n=7), the reference standard edema mass was 7.1±4.4 g compared to 16.3±7.7 g at baseline. Computer algorithm estimates showed the same pattern of change with 5.7±5.7 g at follow-up compared to 20.8±13.8 g at baseline. Although there was a significant degree of discrepancy between reference standard and computer algorithm estimates of edema mass in individual patients, their overall agreement was good, with intraclass correlation coefficient ICC(3, 1)=0.753.
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Affiliation(s)
- R I Johnstone
- Department of Medical Physics and Engineering, Leeds Teaching Hospitals Trust, and School of Medicine, University of Leeds, Leeds, United Kingdom
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25
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Kirschner R, Varga-Szemes A, Simor T, Suranyi P, Kiss P, Ruzsics B, Brott BC, Elgavish A, Elgavish GA. Acute infarct selective MRI contrast agent. Int J Cardiovasc Imaging 2011; 28:285-93. [PMID: 21336553 DOI: 10.1007/s10554-011-9811-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2010] [Accepted: 01/17/2011] [Indexed: 11/24/2022]
Abstract
To determine the infarct affinity of a low molecular weight contrast agent, Gd(ABE-DTTA), during the subacute phase of myocardial infarct (MI). Dogs (n = 7) were examined, using a closed-chest, reperfused MI model. MI was generated by occluding for 180 min the left anterior descending (LAD) coronary artery with an angioplasty balloon. DE-MRI images with Gd(ABE-DTTA) were obtained on days 4, 14, and 28 after MI. Control DE-MRI by Gd(DTPA) was carried out on day 27. T2-TSE images were acquired on day 3, 13 and 27. Triphenyltetrazolium chloride (TTC) histomorphometry validated postmortem the existence of infarct. Gd(ABE-DTTA) highlighted the infarct on day 4, but not at all on day 14 or on day 28, following MI. On day 4, the mean ± SD signal intensity (SI) of infarcted myocardium in the presence of Gd(ABE-DTTA) significantly differed from that of healthy myocardium (45 ± 6.0 vs. 10 ± 5.0, P < 0.05), but it did not on day 14 (11 ± 9.4 vs. 10 ± 5.7, P = NS), nor on day 28 (7 ± 1.5 vs. 7 ± 2.4, P = NS). The mean ± SD signal intensity enhancement (SIE) induced by Gd(ABE-DTTA) was 386 ± 165% on day 4, significantly different from mean SIE on day 14 (9 ± 20%), and from mean SIE on day 28 (12 ± 18%), following MI (P < 0.05). The last two mean values did not differ significantly (P = NS) from each other. As control, Gd(DTPA) was used and it did highlight the infarct on day 27, inducing a mean SIE value of 312 ± 40%. The mean SIE on day 3, 13, or 27 did not vary significantly (P = NS) on the T2-TSE images (114 ± 41%, 123 ± 41%, and 150 ± 79%, respectively). Post mortem, the existence of infarcts was confirmed by TTC staining. The infarct affinity of Gd(ABE-DTTA) vanishes in the subacute phase of scar healing, allowing its use for infarct age differentiation early on, immediately following the acute phase.
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Affiliation(s)
- Robert Kirschner
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, MCLM 556, Birmingham, AL 35294-0005, USA
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Simor T, Surányi P, Ruzsics B, Tóth A, Tóth L, Kiss P, Brott BC, Varga-Szemes A, Elgavish A, Elgavish GA. Percent infarct mapping for delayed contrast enhancement magnetic resonance imaging to quantify myocardial viability by Gd(DTPA). J Magn Reson Imaging 2011; 32:859-68. [PMID: 20882616 DOI: 10.1002/jmri.22296] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
PURPOSE To demonstrate the advantages of signal intensity percent-infarct-mapping (SI-PIM) using the standard delayed enhancement (DE) acquisition in assessing viability following myocardial infarction (MI). SI-PIM quantifies MI density with a voxel-by-voxel resolution in clinically used DE images. MATERIALS AND METHODS In canines (n= 6), 96 hours after reperfused MI and administration of 0.2 mmol/kg Gd(DTPA), ex vivo DE images were acquired and SI-PIMs calculated. SI-PIM data were compared with data from DE images analyzed with several thresholding levels using SI(remote+2SD), SI(remote+6SD), SI full width half maximum (SI(FWHM)), and with triphenyl-tetrazolium-chloride (TTC) staining. SI-PIM was also compared to R1 percent infarct mapping (R1-PIM). RESULTS Left ventricular infarct volumes (IV) in DE images, IV(SIremote+2SD) and IV(SIremote+6SD), overestimated (P < 0.05) TTC by medians of 13.21 mL [10.2; 15.2] and 6.2 mL [3.79; 8.23], respectively. SI(FWHM), SI-PIM, and R1-PIM, however, only nonsignificantly underestimated TTC, by medians of -0.10 mL [-0.12, -0.06], -0.86 mL [-1.04; 1.54], and -1.30 mL [-4.99; -0.29], respectively. The infarct-involved voxel volume (IIVV) of SI-PIM, 32.4 mL [21.2, 46.3] is higher (P < 0.01) than IIVVs of SI(FWHM) 8.3 mL [3.79, 19.0]. SI-PIM(FWHM), however, underestimates TTC (-5.74 mL [-11.89; -2.52] (P < 0.01)). Thus, SI-PIM outperforms SI(FWHM) because larger IIVVs are obtained, and thus PIs both in the rim and the core of the infarcted tissue are characterized, in contradistinction from DE-SI(FWHM), which shows mainly the infarct core. CONCLUSION We have shown here, ex vivo, that SI-PIM has the same advantages as R1-PIM, but it is based on the scanning sequences of DE imaging, and thus it is obtainable within the same short scanning time as DE. This makes it a practical method for clinical studies.
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Affiliation(s)
- Tamás Simor
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, Alabama 35294-0005, USA
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Tao Q, Milles J, Zeppenfeld K, Lamb HJ, Bax JJ, Reiber JHC, van der Geest RJ. Automated segmentation of myocardial scar in late enhancement MRI using combined intensity and spatial information. Magn Reson Med 2011; 64:586-94. [PMID: 20665801 DOI: 10.1002/mrm.22422] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Accurate assessment of the size and distribution of a myocardial infarction (MI) from late gadolinium enhancement (LGE) MRI is of significant prognostic value for postinfarction patients. In this paper, an automatic MI identification method combining both intensity and spatial information is presented in a clear framework of (i) initialization, (ii) false acceptance removal, and (iii) false rejection removal. The method was validated on LGE MR images of 20 chronic postinfarction patients, using manually traced MI contours from two independent observers as reference. Good agreement was observed between automatic and manual MI identification. Validation results showed that the average Dice indices, which describe the percentage of overlap between two regions, were 0.83 +/- 0.07 and 0.79 +/- 0.08 between the automatic identification and the manual tracing from observer 1 and observer 2, and the errors in estimated infarct percentage were 0.0 +/- 1.9% and 3.8 +/- 4.7% compared with observer 1 and observer 2. The difference between the automatic method and manual tracing is in the order of interobserver variation. In conclusion, the developed automatic method is accurate and robust in MI delineation, providing an objective tool for quantitative assessment of MI in LGE MR imaging.
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Affiliation(s)
- Qian Tao
- LKEB - Division of Image Processing, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands.
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Schoenhagen P, White HD. Magnetic Resonance Imaging and Troponin Elevation Following Percutaneous Coronary Intervention. JACC Cardiovasc Interv 2010; 3:959-62. [DOI: 10.1016/j.jcin.2010.06.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2010] [Accepted: 06/09/2010] [Indexed: 11/29/2022]
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Kwon DH, Desai MY. Cardiac magnetic resonance in hypertrophic cardiomyopathy: current state of the art. Expert Rev Cardiovasc Ther 2010; 8:103-11. [PMID: 20014937 DOI: 10.1586/erc.09.108] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Hypertrophic cardiomyopathy is a complex disorder with significant heterogeneity in clinical characteristics and natural history. Traditionally, the diagnosis has been based on clinical assessment and echocardiography; however, persistent challenges in its noninvasive evaluation remain. Hence, improved diagnostic techniques could lead to better risk stratification of patients, which would potentially identify patients likely to benefit from effective therapies. Recent studies have demonstrated the increasing utility of cardiac magnetic resonance in the management of this disease. With the increasing utilization of genetics, cardiac magnetic resonance is likely to play an even more important role in discerning the subtle morphologic differences seen in such patients with similar genotypic profiles.
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Affiliation(s)
- Deborah H Kwon
- Heart and Vascular Institute, Cleveland Clinic, Cleveland, OH 44195, USA
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Kwon DH, Halley CM, Popovic ZB, Carrigan TP, Zysek V, Setser R, Schoenhagen P, Flamm SD, Starling RC, Desai MY. Gender differences in survival in patients with severe left ventricular dysfunction despite similar extent of myocardial scar measured on cardiac magnetic resonance. Eur J Heart Fail 2010; 11:937-44. [PMID: 19789396 DOI: 10.1093/eurjhf/hfp118] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
AIMS We sought to determine the association between myocardial scarring, gender, and survival in patients with significant coronary artery disease (CAD) and severe systolic left ventricular (LV) dysfunction using delayed hyper-enhancement cardiac magnetic resonance imaging (DHE-CMR). METHODS AND RESULTS We studied 339 patients (24% women, mean age 65 +/- 11 years) referred for assessment of myocardial viability by DHE-CMR. Scar was defined as myocardium with an intensity >2 SD above viable myocardium. Left ventricular scar (defined as a percentage of total LV myocardium), LV volumes, risk factors, cardiac transplantation (CTx), and all-cause mortality were recorded. There were 84 deaths and five CTx over 3.7 +/- 1.6 years (median 4 years, interquartile range 2.6-4.9 years). Left ventricular ejection fraction (LVEF) in men was only slightly different from women (23% +/- 9 vs. 25% +/- 10, P = 0.05), whereas mean scar % was similar in both groups (32 +/- 21 vs. 29 +/- 20, P = 0.3). On univariable survival analysis, age [hazard ratio, HR, 1.03 (1.01-1.05), P = 0.002], female gender [HR 2.02 (1.31-3.12), P = 0.001], and scar % [HR 1.01 (1.003-1.02), P = 0.009] predicted outcomes; and also on multivariable analysis (chi(2) 32, P < 0.0001). Women with scar % greater than the median had more events, compared with men with or without a high scar burden (log-rank P < 0.001). CONCLUSION In patients with CAD and severely reduced LVEF, women have worse outcomes than men, irrespective of myocardial scar burden.
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Affiliation(s)
- Deborah H Kwon
- Department of Cardiovascular Medicine, Heart and Vascular Institute, Cleveland Clinic, Cleveland, OH 44195, USA
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Recent advances in cardiac resynchronization therapy: echocardiographic modalities, patient selection, optimization, non-responders—all you need to know for more efficient CRT. Int J Cardiovasc Imaging 2009; 26:177-91. [DOI: 10.1007/s10554-009-9523-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2009] [Accepted: 10/16/2009] [Indexed: 12/24/2022]
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Kwon DH, Halley CM, Carrigan TP, Zysek V, Popovic ZB, Setser R, Schoenhagen P, Starling RC, Flamm SD, Desai MY. Extent of left ventricular scar predicts outcomes in ischemic cardiomyopathy patients with significantly reduced systolic function: a delayed hyperenhancement cardiac magnetic resonance study. JACC Cardiovasc Imaging 2009; 2:34-44. [PMID: 19356530 DOI: 10.1016/j.jcmg.2008.09.010] [Citation(s) in RCA: 221] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2008] [Revised: 08/29/2008] [Accepted: 09/09/2008] [Indexed: 01/03/2023]
Abstract
OBJECTIVES The objective of the study was to determine whether the extent of left ventricular scar, measured with delayed hyperenhancement cardiac magnetic resonance (DHE-CMR), predicts survival in patients with ischemic cardiomyopathy (ICM) and severely reduced left ventricular ejection fraction (LVEF). BACKGROUND Patients with ICM and reduced LVEF have poor survival. Such patients have a high myocardial scar burden. CMR is highly accurate in delineation of myocardial scar. METHODS We studied 349 patients (76% men) with severe ICM (>or=70% disease in >or=1 epicardial coronary, and mean LVEF of 24%) that underwent DHE-CMR (Siemens 1.5-T scanner, Erlangen, Germany), between 2003 and 2006. Scar (quantified as percentage of myocardium) was defined on DHE-MR images as an intensity >2 standard deviations above the viable myocardium. Transmurality score was semiquantitatively recorded in a 17-segment model as: 0 = no scar, 1 = 1% to 25% scar, 2 = 26% to 50%, 3 = 51% to 75%, and 4 = >75%. The LVEF, demographic data, risk factors, need for cardiac transplantation (CTx), and all-cause mortality were recorded. RESULTS The mean age and follow-up were 65 +/- 11 years and 2.6 +/- 1.2 years (median 2.4 years [1.1, 3.5]), respectively. There were 56 events (51 deaths and 5 CTx). Mean scar percentage and transmurality score were higher in patients with events versus those without (39 +/- 22 vs. 30 +/- 20, p = 0.003, and 9.7 +/- 5 vs. 7.8 +/- 5, p = 0.004). On Cox proportional hazard survival analysis, quantified scar was greater than the median (30% of total myocardium), and female gender predicted events (relative risk 1.75 [95% Confidence Interval: 1.02 to 3.03] and relative risk 1.83 [95% Confidence Interval: 1.06 to 3.16], respectively, both p = 0.03). CONCLUSIONS In patients with ICM and severely reduced LVEF, a greater extent of myocardial scar, delineated by DHE-CMR is associated with increased mortality or the need for cardiac transplantation, potentially aiding further risk-stratification.
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Affiliation(s)
- Deborah H Kwon
- Department of Cardiovascular Medicine, Cleveland Clinic, Cleveland, Ohio 44195, USA
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Kwon DH, Smedira NG, Rodriguez ER, Tan C, Setser R, Thamilarasan M, Lytle BW, Lever HM, Desai MY. Cardiac Magnetic Resonance Detection of Myocardial Scarring in Hypertrophic Cardiomyopathy. J Am Coll Cardiol 2009; 54:242-9. [DOI: 10.1016/j.jacc.2009.04.026] [Citation(s) in RCA: 193] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/27/2008] [Revised: 02/23/2009] [Accepted: 04/03/2009] [Indexed: 11/16/2022]
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Abstract
Integrative models of cardiac physiology are important for understanding disease and planning intervention. Multimodal cardiovascular imaging plays an important role in defining the computational domain, the boundary/initial conditions, and tissue function and properties. Computational models can then be personalized through information derived from in vivo and, when possible, non-invasive images. Efforts are now established to provide Web-accessible structural and functional atlases of the normal and pathological heart for clinical, research and educational purposes. Efficient and robust statistical representations of cardiac morphology and morphodynamics can thereby be obtained, enabling quantitative analysis of images based on such representations. Statistical models of shape and appearance can be built automatically from large populations of image datasets by minimizing manual intervention and data collection. These methods facilitate statistical analysis of regional heart shape and wall motion characteristics across population groups, via the application of parametric mathematical modelling tools. These parametric modelling tools and associated ontological schema also facilitate data fusion between different imaging protocols and modalities as well as other data sources. Statistical priors can also be used to support cardiac image analysis with applications to advanced quantification and subject-specific simulations of computational physiology.
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Affiliation(s)
- Alistair A Young
- Department of Anatomy with Radiology, University of Auckland, Auckland Mail Centre, Private Bag, Auckland, New Zealand.
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Association Between Regional Ventricular Function and Myocardial Fibrosis in Hypertrophic Cardiomyopathy Assessed by Speckle Tracking Echocardiography and Delayed Hyperenhancement Magnetic Resonance Imaging. J Am Soc Echocardiogr 2008; 21:1299-305. [DOI: 10.1016/j.echo.2008.09.011] [Citation(s) in RCA: 182] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2008] [Indexed: 02/07/2023]
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Ruzsics B, Surányi P, Kiss P, Brott BC, Elgavish A, Simor T, Elgavish GA. Head-to-head comparison between delayed enhancement and percent infarct mapping for assessment of myocardial infarct size in a canine model. J Magn Reson Imaging 2008; 28:1386-92. [DOI: 10.1002/jmri.21571] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
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Bexell D, Setser RM, Schoenhagen P, Lieber ML, Brener SJ, Ivanc TB, Balazs EM, O' Donnell TP, Stillman AE, Arheden H, Wagner GS, White RD. Influence of coronary artery stenosis severity and coronary collateralization on extent of chronic myocardial scar: insights from quantitative coronary angiography and delayed-enhancement MRI. Open Cardiovasc Med J 2008; 2:79-86. [PMID: 19337359 PMCID: PMC2627523 DOI: 10.2174/1874192400802010079] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2008] [Revised: 08/25/2008] [Accepted: 08/27/2008] [Indexed: 11/22/2022] Open
Abstract
Objectives: In patients with chronic ischemic heart disease, the relationship between coronary artery lesion severity and myocardial scarring is unknown.The purpose of this study was to examine the relationship between proximal coronary artery stenosis severity, the amount of coronary collateralization, and myocardial scar extent in the distal distribution of the affected coronary artery based on both quantitative coronary angiography (QCA) and delayed-enhancement magnetic resonance imaging (DE–MRI). Methods: Thirty-four patients (26 males, 8 females; age range: 35-86 years) with a coronary artery containing a single, proximal stenosis ≥30% by quantitative coronary angiography (QCA) underwent DE-MRI. The relationship between stenosis severity, collateralization, and myocardial scar morphology (area, transmurality and patchiness) was examined using linear mixed-model ANCOVA. Results: There was a statistically significant correlation between stenosis severity and scar extent (r=0.53, p<0.01). Patients with hemodynamically significant stenoses (≥70%) exhibited significantly greater collateralization (p<0.05) and scar extent (p<0.01) than patients with <70% stenosis. However, scarring was often found in patients with stenoses <70%. Also, greater stenosis severity (93±14%) and mean scar extent (41±35%) were found in patients with collaterals than in patients without collaterals (diameter stenosis 48±10%, p<0.01) (scar extent 19±29%, p=0.01). Conclusions: Using QCA and DE-MRI, we demonstrate a significant relationship between coronary artery stenosis severity and myocardial scar extent, in the absence of a documented history of acute infarction. The relationship likely reflects increasing ischemia leading to scar formation in the range of angiographically significant stenosis. However, in the absence of collateralization, scar was observed without significant stenosis, especially in females.
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Affiliation(s)
- Daniel Bexell
- Departments of Diagnostic Radiology and Clinical Physiology, Duke University Medical Center, Durham, NC, USA
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Folkesson J, Samset E, Kwong RY, Westin CF. Unifying Statistical Classification and Geodesic Active Regions for Segmentation of Cardiac MRI. ACTA ACUST UNITED AC 2008; 12:328-34. [DOI: 10.1109/titb.2007.912179] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Rapid short-duration hypothermia with cold saline and endovascular cooling before reperfusion reduces microvascular obstruction and myocardial infarct size. BMC Cardiovasc Disord 2008; 8:7. [PMID: 18402663 PMCID: PMC2323360 DOI: 10.1186/1471-2261-8-7] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2007] [Accepted: 04/10/2008] [Indexed: 11/21/2022] Open
Abstract
Background The aim of this study was to evaluate the combination of a rapid intravenous infusion of cold saline and endovascular hypothermia in a closed chest pig infarct model. Methods Pigs were randomized to pre-reperfusion hypothermia (n = 7), post-reperfusion hypothermia (n = 7) or normothermia (n = 5). A percutaneous coronary intervention balloon was inflated in the left anterior descending artery for 40 min. Hypothermia was started after 25 min of ischemia or immediately after reperfusion by infusion of 1000 ml of 4°C saline and endovascular hypothermia. Area at risk was evaluated by in vivo SPECT. Infarct size was evaluated by ex vivo MRI. Results Pre-reperfusion hypothermia reduced infarct size/area at risk by 43% (46 ± 8%) compared to post-reperfusion hypothermia (80 ± 6%, p < 0.05) and by 39% compared to normothermia (75 ± 5%, p < 0.05). Pre-reperfusion hypothermia infarctions were patchier in appearance with scattered islands of viable myocardium. Pre-reperfusion hypothermia abolished (0%, p < 0.001), and post-reperfusion hypothermia significantly reduced microvascular obstruction (10.3 ± 5%; p < 0.05), compared to normothermia: (30.2 ± 5%). Conclusion Rapid hypothermia with cold saline and endovascular cooling before reperfusion reduces myocardial infarct size and microvascular obstruction. A novel finding is that hypothermia at the onset of reperfusion reduces microvascular obstruction without reducing myocardial infarct size. Intravenous administration of cold saline combined with endovascular hypothermia provides a method for a rapid induction of hypothermia suggesting a potential clinical application.
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Heiberg E, Ugander M, Engblom H, Götberg M, Olivecrona GK, Erlinge D, Arheden H. Automated Quantification of Myocardial Infarction from MR Images by Accounting for Partial Volume Effects: Animal, Phantom, and Human Study. Radiology 2008; 246:581-8. [DOI: 10.1148/radiol.2461062164] [Citation(s) in RCA: 163] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Kwon DH, Setser RM, Popović ZB, Thamilarasan M, Sola S, Schoenhagen P, Garcia MJ, Flamm SD, Lever HM, Desai MY. Association of myocardial fibrosis, electrocardiography and ventricular tachyarrhythmia in hypertrophic cardiomyopathy: a delayed contrast enhanced MRI study. Int J Cardiovasc Imaging 2008; 24:617-25. [PMID: 18204915 DOI: 10.1007/s10554-008-9292-6] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2007] [Accepted: 01/07/2008] [Indexed: 02/05/2023]
Abstract
BACKGROUND Patients with hypertrophic cardiomyopathy (HCM) are predisposed to ventricular tachyarrhythmia (VT); likely due to myocardial fibrosis or disarray. Delayed hyperenhancement magnetic resonance imaging (DHE-MRI) accurately detects myocardial fibrosis (scar). We sought to determine the association between septal thickness, myocardial scar and VT. METHODS Sixty-eight patients (mean age 44 years, 69% males) with documented HCM underwent cine MRI (Siemens Sonata or Avanto 1.5 T scanner, Erlangen, Germany) in short axis, 2, 3 and 4-chamber views and maximal interventricular septal thickness was recorded at end-diastole. Corresponding DHE-MR images (8-10 mm thick) were obtained, approximately 20 min after injection of 0.2 mmol/kg of Gadolinium. Scar was determined semi-automatically (as % of total myocardium) using VPT software (Siemens) and defined as intensity >2 SD above viable myocardium in a 12 segment short-axis model at apex, mid LV and base. Presence of VT (documented on ambulatory ECG monitoring) and history of sudden death were recorded. RESULTS One patient had a history of sudden death and 9 (13%) had VT on ambulatory ECG monitoring. On DHE-MRI, 39 (57%) patients had myocardial scar. Patients with VT had significantly higher scar %, compared to those without: 14% [6, 19] vs. 6% [0, 10], P = 0.01. On logistic regression, only the size of the scar was a significant predictor of VT (P = 0.03). CONCLUSIONS HCM subjects with VT have a higher % of myocardial scarring noted on DHE-MRI, independent of septal thickness or beta-blocker use.
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Affiliation(s)
- Deborah H Kwon
- Department of Cardiovascular Medicine, Cleveland Clinic, Cleveland, OH 44195, USA
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Evaluation of acute myocardial infarction with late enhancement pattern on MRI compared with 201Tl and 99mTc-hydroxymethylenediphosphonate (HMDP) dual single photon emission computed tomography (SPECT) images. Invest Radiol 2007; 42:765-70. [PMID: 18030199 DOI: 10.1097/rli.0b013e3180cc2056] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
UNLABELLED The purpose of this study is to evaluate reperfused acute myocardial infarction with late enhancement (LE) pattern on contrast-enhanced magnetic resonance imaging compared with myocardial single photon emission computed tomography (SPECT) images. MATERIALS AND METHODS Magnetic resonance and 201Tl and 99mTc-hydroxymethylenediphosphonate SPECT images were obtained from 40 patients within 6 days of reperfused myocardial infarction. We assessed the myocardial LE pattern using the true fast imaging with steady-state free precession sequence after the injection of Gd-DTPA. Patients were classified into 3 groups: group 1 included patients with localized endocardial enhancement; group 2, patients with transmural enhancement; and group 3, patients with LE and a residual defect. RESULTS There were 9 patients (23%) in group 1, 15 (38%) in group 2, and 15 (38%) in group 3. In 1 patient, LE was not detected (3%). The %201Tl uptake for the infarcted area was 60.7 +/- 7.2 (mean +/- SD) for group 1, 49.5 +/- 12.3 (P < 0.05 vs. group 1) for group 2, and 36.9 +/- 8.2 (P < 0.0001 vs. group 1, P = 0.005 vs. group 2) for group 3. An overlap pattern of 201Tl and 99mTc was observed in 9 of the group 1 patients (100%) and 9 of the group 2 patients (60%), but was not evident in group 3 (0%). CONCLUSIONS LE with residual defect is an important indicator of microvascular obstruction after reperfusion therapy.
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Ebeling Barbier C, Bjerner T, Hansen T, Andersson J, Lind L, Hulthe J, Johansson L, Ahlström H. Clinically Unrecognized Myocardial Infarction Detected at MR Imaging May Not Be Associated with Atherosclerosis. Radiology 2007; 245:103-10. [PMID: 17717330 DOI: 10.1148/radiol.2451061664] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To prospectively investigate whether there is support for the hypothesis that clinically unrecognized myocardial infarctions (UMIs) detected at magnetic resonance (MR) imaging have an atherosclerotic pathogenesis similar to that of recognized myocardial infarctions (RMIs). MATERIALS AND METHODS After ethics committee approval and informed consent were obtained, gadolinium-enhanced whole-body MR angiography and late-enhancement MR imaging were performed in 248 randomly chosen 70-year-old subjects (123 women, 125 men). Imaging included the aorta and the carotid, renal, and lower limb arteries to the ankle, but not the coronary arteries. Subjects with myocardial infarction (MI) scars at late-enhancement MR imaging were classified as having RMI (n=11) (those with a diagnosis of MI at the hospital) or UMI (n=49) (those without a diagnosis of MI at the hospital). The presence of 50% or higher luminal narrowing in any vessel at whole-body MR angiography was considered to represent significant atherosclerosis. Intima-media thickness of the common carotid artery was measured with ultrasonography. C-reactive protein level was measured, and coronary heart disease risk was estimated. Observers were blinded to any previous results. The chi2 test, analysis of variance, and Bonferroni correction were used for statistical analyses. RESULTS None of the measured parameters differed significantly between the group without MI scars and the UMI group, but parameters were significantly increased in the RMI group (P<.05) compared with those in the group without MI scars. Forty-two of 49 UMIs and nine of 11 RMIs were located within inferolateral segments of the left ventricle. CONCLUSION MR imaging-detected UMIs might have a different pathogenesis from that of RMIs or may have the same pathogenesis but may manifest at an earlier stage.
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Surányi P, Kiss P, Brott BC, Simor T, Elgavish A, Ruzsics B, Saab-Ismail NH, Elgavish GA. Percent infarct mapping: AnR1-map-based CE-MRI method for determining myocardial viability distribution. Magn Reson Med 2006; 56:535-45. [PMID: 16892184 DOI: 10.1002/mrm.20979] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Viability detection is crucial for the management of myocardial infarction (MI). Signal intensity (SI)-based MRI methods may overestimate infarct size in vivo. In contrast to SI, the longitudinal relaxation-rate enhancement (DeltaR1) is an intrinsic parameter that is linearly proportional to the concentration of contrast agent (CA). Determining DeltaR1 in the presence of an infarct-avid persistent CA (PCA) allows determination of the per-voxel percentage of infarcted tissue. Introduced here is a DeltaR1-based CE-MRI method, termed percent infarct mapping (PIM), for quantifying myocardial viability following delayed PCA accumulation. In a canine MI model (N=6), PIMs were generated using a persistent CA (PCA) and validated using triphenyltetrazolium-chloride (TTC) histochemistry. Voxel-by-voxel R1 maps of the entire left ventricle (LV) were generated 24 and 48 hr after PCA administration using inversion recovery (IR) with multiple inversion times (TIs). PI values were calculated voxel by voxel. Significant correlations (P<0.01, R=0.97) were obtained for PI per slice (PIS) determined using PIM vs. corresponding TTC-based values. Median deviations of PIS with PIM from that with TTC were only 1.01% and -0.53%, at 24 hr and 48 hr. Median deviations from the true infarction fraction (IF) were 1.23% and 0.49% of LV at 24 hr and 48 hr, respectively. No significant difference was found between PIM24 hr and PIM48 hr. DeltaR1-based PIM is an accurate and reproducible method for quantifying myocardial viability distribution, and thus enhances the clinical utility of CE-MRI.
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Affiliation(s)
- Pál Surányi
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, Alabama 35294-0005, USA
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Barbier CE, Bjerner T, Johansson L, Lind L, Ahlström H. Myocardial Scars More Frequent Than Expected. J Am Coll Cardiol 2006; 48:765-71. [PMID: 16904547 DOI: 10.1016/j.jacc.2006.05.041] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2006] [Revised: 04/07/2006] [Accepted: 04/17/2006] [Indexed: 11/27/2022]
Abstract
OBJECTIVES The aim of this study was to investigate the prevalence of clinically recognized myocardial infarctions (RMIs) and unrecognized myocardial infarctions (UMIs) in 70-year-old subjects, assessed with magnetic resonance imaging (MRI), and to relate the findings to cardiac function and morbidity. BACKGROUND Late enhancement MRI identifies myocardial scars and thereby has the potential to detect UMI. METHODS Cardiac MRI was performed on 259 randomly chosen 70-year-old subjects. Late enhancement and cine sequences were acquired, and the ejection fraction and left ventricular (LV) mass were calculated. Late enhancement involving the subendocardial layer was considered to represent myocardial infarction (MI) scars, and their volumes were calculated. Information on cardiac morbidity and risk factors was collected from medical records and from a health examination. Subjects with MI scars, with or without a hospital diagnosis of MI were classified as RMI or UMI, respectively. RESULTS The images from 248 subjects (123 women, 125 men) were assessable. Myocardial infarction scars were found in 60 subjects (24.2%), in 49 of whom (19.8%) they were UMIs. The volumes of the UMIs were significantly smaller than those of the RMIs. There was an increased frequency of chest pain symptoms among the subjects with UMI or RMI compared with those without MI scars. Ejection fraction was significantly lower and LV mass significantly larger in the subjects with UMI or RMI than in those without MI scars. CONCLUSIONS Unrecognized MI detected with MRI was more frequent than expected in 70-year-old subjects. The subjects displaying these UMIs may represent a previously unknown potential risk group for future cardiovascular events.
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Kolipaka A, Chatzimavroudis GP, White RD, O'Donnell TP, Setser RM. Segmentation of non-viable myocardium in delayed enhancement magnetic resonance images. Int J Cardiovasc Imaging 2006; 21:303-11. [PMID: 16015446 DOI: 10.1007/s10554-004-5806-z] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2004] [Accepted: 10/13/2004] [Indexed: 10/25/2022]
Abstract
PURPOSE To evaluate six algorithms for segmenting non-viable left ventricular (LV) myocardium in delayed enhancement (DE) magnetic resonance imaging (MRI). METHODS Twenty-three patients with known chronic ischemic heart disease underwent DE-MRI. DE images were first manually thresholded using an interactive region-filling tool to isolate non-viable myocardium. Then, six thresholding algorithms, based on the image intensity characteristics of either LV blood pool (BP), viable LV myocardium, or both, were applied to each image. For the Mean-2SD(BP) algorithm, thresholds were equal to the mean BP intensity minus twice its standard deviation. For the Mean + 2SD(Semi), Mean + 3SD(Semi), Mean + 2SD(Auto), and Mean + 3SD(Auto) algorithms, thresholds equaled the mean intensity of viable myocardium plus twice (or thrice, as denoted by the name) the standard deviation of intensity (subscripts denote how these values were determined: automatic or semi-automatic). For the Minimum Intensity algorithm, the threshold equaled the minimum intensity between the BP and LV myocardium mean intensities. Percent Scar was defined as the ratio of non-viable to total myocardial pixels in each image. Agreement between each algorithm and manual thresholding was assessed using Bland-Altman analysis. RESULTS Mean Percent Scar was 25 +/- 16% by manual thresholding. Five of the six algorithms demonstrated mean bias within +/-3% (all except Mean+2SD(Auto)); however, limits of agreement (LoA) were large in general (range 12-36%). The best overall agreement was demonstrated by the Mean + 2SD(Semi) (bias, 0%; LoA, 12%) and Mean + 3SD(Semi)(bias, -3%; LoA, 14%) algorithms. CONCLUSION On average, five of the six algorithms proved satisfactory for clinical implementation; however, in some images, manual correction of automatic results was necessary.
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Affiliation(s)
- Arunark Kolipaka
- Section of Cardiovascular Imaging, Division of Radiology, The Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA
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Hsu LY, Ingkanisorn WP, Kellman P, Aletras AH, Arai AE. Quantitative myocardial infarction on delayed enhancement MRI. Part II: Clinical application of an automated feature analysis and combined thresholding infarct sizing algorithm. J Magn Reson Imaging 2006; 23:309-14. [PMID: 16450368 DOI: 10.1002/jmri.20495] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
PURPOSE To compare global and regional myocardial infarction (MI) measurements on clinical gadolinium-enhanced magnetic resonance (MR) images using human manual contouring and a computer algorithm previously validated by histopathology, and to study the degree to which visual assessment and human contouring of infarct extent agreed with the computer algorithm. MATERIALS AND METHODS Infarct size in 20 patients was measured by human manual contouring and with an automated feature analysis and combined thresholding (FACT) computer algorithm. Short-axis slices were divided into myocardial sectors for regional analysis. Extent of infarction was also graded visually by consensus of expert readers and compared to human and computer contouring. RESULTS Despite good correlations (R = 0.93-0.95) between human contouring and the FACT algorithm, human contouring overestimated infarct size by 3.8% of the left ventricle (23.8% of the MI) area (P < 0.001). Human contouring also overestimated the circumferential extent, transmural extent, and extent of infarction within a sector by 7.1%, 18.2%, and 27.9%, respectively (all P < 0.001). Both consensus reading and human contouring overestimated infarct grades compared with the FACT algorithm (P = 0.002 and P < 0.001). CONCLUSION Clinically relevant overestimation of MI can occur in visual interpretation and in human manual contouring, particularly with respect to extent of infarction on a regional basis.
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Affiliation(s)
- Li-Yueh Hsu
- Laboratory of Cardiac Energetics, National Heart Lung and Blood Institute, National Institutes of Health/DHHS, 10 Center Drive, Bethesda, MD 20892, USA
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Hsu LY, Natanzon A, Kellman P, Hirsch GA, Aletras AH, Arai AE. Quantitative myocardial infarction on delayed enhancement MRI. Part I: Animal validation of an automated feature analysis and combined thresholding infarct sizing algorithm. J Magn Reson Imaging 2006; 23:298-308. [PMID: 16450367 DOI: 10.1002/jmri.20496] [Citation(s) in RCA: 125] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
PURPOSE To develop a computer algorithm to measure myocardial infarct size in gadolinium-enhanced magnetic resonance (MR) imaging and to validate this method using a canine histopathological reference. MATERIALS AND METHODS Delayed enhancement MR was performed in 11 dogs with myocardial infarction (MI) determined by triphenyltetrazolium chloride (TTC). Infarct size on in vivo and ex vivo images was measured by a computer algorithm based on automated feature analysis and combined thresholding (FACT). For comparison, infarct size by human manual contouring and simple intensity thresholding (based on two standard deviation [2SD] and full width at half maximum [FWHM]) were studied. RESULTS Both in vivo and ex vivo MR infarct size measured by the FACT algorithm correlated well with TTC (R = 0.95-0.97) and showed no significant bias on Bland Altman analysis (P = not significant). Despite similar correlations (R = 0.91-0.97), human manual contouring overestimated in vivo MR infarct size by 5.4% of the left ventricular (LV) area (equivalent to 55.1% of the MI area) vs. TTC (P < 0.001). Infarct size measured by simple intensity thresholdings was less accurate than the proposed algorithm (P < 0.001 and P = 0.007). CONCLUSION The FACT algorithm accurately measured MI size on delayed enhancement MR imaging in vivo and ex vivo. The FACT algorithm was also more accurate than human manual contouring and simple intensity thresholding approaches.
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Affiliation(s)
- Li-Yueh Hsu
- Laboratory of Cardiac Energetics, National Heart Lung and Blood Institute, National Institutes of Health/DHHS, 10 Center Drive, Bethesda, MD 20892, USA
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Papadopoulos CE, Zaglavara T, Karvounis HI, Haaverstad R, Parharidis GE, Louridas GE, Kenny A. QT dispersion is determined by the relative extent of normal, hibernating, and scarred myocardium in patients with chronic ischemic cardiomyopathy. A dobutamine stress echocardiography study before and after surgical revascularization. J Electrocardiol 2005; 39:103-9. [PMID: 16387061 DOI: 10.1016/j.jelectrocard.2005.07.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2005] [Indexed: 12/14/2022]
Abstract
INTRODUCTION The aim of the present study was to evaluate a possible association between QT dispersion (QTd) and the amount of viable and scarred myocardial tissue after revascularization in patients with coronary artery disease and impaired left ventricular (LV) function. METHODS Twenty-two patients with ischemic LV dysfunction underwent dobutamine stress echocardiography (DSE) before and 6 months after surgical revascularization. Mean corrected QT-interval value and QTd were calculated at baseline and follow-up. Segments consisting of transmural scar were determined as the segments that remained akinetic in all stages of DSE despite reperfusion. Patients were divided into 2 groups according to the number of definitive segments consisting of transmural scar (minor scar group, < or =2 scarred segments; major scar group, >2 scarred segments). RESULTS QTd was significantly lower in the minor compared with the major scar group at baseline and follow-up (mean [SD], 61 [22] vs 98 [33] milliseconds, P = .008, and 45 [18] vs 68 [21] milliseconds, P = .01, respectively). Segments consisting of transmural scar positively correlated to QTd at baseline (r = 0.53, P = .01) and follow-up (r = 0.62, P = .002). CONCLUSIONS QTd is positively correlated with the extent of scarred myocardial tissue assessed by DSE. Surgical revascularization results in reduction of QTd in all patients with hibernating myocardium and LV dysfunction.
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MacDonald KA, Wisner ER, Larson RF, Klose T, Kass PH, Kittleson MD. Comparison of myocardial contrast enhancement via cardiac magnetic resonance imaging in healthy cats and cats with hypertrophic cardiomyopathy. Am J Vet Res 2005; 66:1891-4. [PMID: 16334945 DOI: 10.2460/ajvr.2005.66.1891] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To quantify myocardial contrast enhancement (MCE) of the left ventricle (LV) by use of cardiac magnetic resonance imaging (CMRI) in healthy cats and cats with hypertrophic cardiomyopathy (HCM) and to compare MCE between the 2 groups. ANIMALS 10 healthy cats and 26 Maine Coon cats with moderate to severe HCM but without clinical evidence of congestive heart failure. PROCEDURE Anesthetized cats underwent gradient echo CMRI examination. Short-axis images of the LV were acquired before and 7 minutes after IV administration of gadolinium dimeglumine. Regions of interest were manually traced in the quadrants of 5 mid-LV slices acquired at end systole, and the MCE percentage was calculated from summed weight-averaged data from all slices. Doppler tissue imaging echocardiography was performed to measure the early diastolic myocardial velocity (Em) as an index of diastolic function. Three-way repeated-measures ANOVA was used to determine differences in MCE between cats with HCM and healthy cats. Simple linear regression was used to assess whether MCE was correlated with LV mass, LV mass index (LVMI), or Em. A Student t test was used to compare the SDs of the postcontrast myocardial signal intensity between the 2 groups. RESULTS There was no difference in MCE between cats with HCM and healthy cats. There was no correlation of MCE with LV mass, LVMI, or Em. There was no difference in heterogeneity of signal intensities of LV myocardium between the 2 groups. CONCLUSIONS AND CLINICAL RELEVANCE Contrast-enhancement CMRI was not useful in detecting diffuse myocardial fibrosis in cats with HCM.
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MESH Headings
- Animals
- Cardiomyopathy, Hypertrophic, Familial/diagnosis
- Cardiomyopathy, Hypertrophic, Familial/pathology
- Cardiomyopathy, Hypertrophic, Familial/veterinary
- Cat Diseases/diagnosis
- Cats
- Contrast Media/chemistry
- Echocardiography, Doppler/veterinary
- Heterocyclic Compounds/chemistry
- Hypertrophy, Left Ventricular/diagnosis
- Hypertrophy, Left Ventricular/pathology
- Hypertrophy, Left Ventricular/veterinary
- Linear Models
- Magnetic Resonance Imaging/methods
- Magnetic Resonance Imaging/veterinary
- Meglumine/analogs & derivatives
- Meglumine/chemistry
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Affiliation(s)
- Kristin A MacDonald
- Department of Medicine and Epidemiology, University of California, Davis 95616, USA
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