心血管磁共振评估急性心肌梗死可挽救心肌的研究进展

可挽救心肌或心肌挽救指数对急性心肌梗死患者治疗策略选择、疗效评价、预后判断有重要价值。计算可挽救心肌的前提是准确评估心肌危险区和梗死核心。心血管磁共振(CMR)能较准确评估危险区及梗死核心。本文将对CMR常用的扫描技术(T2WI、灌注成像、延迟强化等)及新的扫描技术(T2mapping、T1mapping、T1ρ等)评估急性心肌梗死危险区和梗死核心的机制、优势、目前存在问题及研究趋势进行综述。     

心脏磁共振在急性心肌梗死危险区评估中的应用进展

危险区是梗死相关动脉所支配的心肌缺血区域,其最主要组织学特点表现为水肿,准确评估危险区并推算可挽救心肌指数与急性心肌梗死的预后评估密切相关。心脏磁共振具有多参数、多模态的成像技术特点,能够定性、定量地测量心肌水肿,评估危险区。本文对T2WI、T2mapping、T1 mapping及DWI等CMR技术在急性心肌梗死危险区评估中的成像机制、优势、存在问题及研究进展进行综述。     

心脏磁共振在扩张型心肌病危险分层及预后评估中的应用进展

扩张型心肌病(dilated cardiomyopathy,DCM)是一类以左心室扩张和左心室收缩功能障碍为主要特征的心脏病,可最终引起心力衰竭、心律失常和猝死,也是目前心脏移植的最主要病因。准确评估DCM患者心脏受累程度,对疾病进行危险分层,识别需密切随访及强化治疗的高危患者尤为重要。心脏磁共振(cardiovascular magnetic resonance,CMR)多模态、多参数成像,常规CMR电影序列能准确评估心脏的形态及功能异常,而基于CMR的组织学与微观结构成像还能为DCM患者的预后提供更多有价值的信息。作者对CMR在DCM的危险分层及预后评估中的应用进展予以综述。     

心脏MR研究冠状动脉微循环功能障碍进展

冠状动脉微循环功能障碍(CMD)主要累及冠状动脉循环小动脉及前小动脉,与患者生活质量和预后密切相关。心脏MR(CMR)检查具有多模态、多参数等优势。本文就CMR评估CMD进展进行综述。     

胸部肿瘤放疗致心脏损伤的磁共振成像和核医学研究进展

放射性心脏损伤(radiation induced heart disease, RIHD)是一种异质性和复杂的疾病,通常情况下临床表现隐匿,并与多种疾病重叠,缺乏特异性。准确识别亚临床心脏受累和早期干预可使胸部肿瘤患者放疗效益最大化,提高预后。心脏磁共振(cardiac magnetic resonance, CMR)和核医学在检测RIHD患者亚临床心脏受累方面具有优势,为RIHD患者的治疗和预后评估提供指导。本文就CMR和核素心肌显像在胸部肿瘤RIHD亚临床诊断及定量评估等方面的应用及研究进展进行综述。     

血清心肌酶及脑钠肽前体对急性心肌梗死的临床诊断价值分析及患者预后相关性研究

<正>急性心肌梗死是老年患者的常见病和多发病,多是由于冠状动脉急性、持续性缺血缺氧引起的心肌坏死,急性心肌梗死患者通常预后较差。因此,探索其临床诊断与预后相关的生物大分子对临床早期诊断和准确治疗具有重要的意义。心肌酶及脑钠肽前体是与心脑血管疾病发生、发展及患者预后密切相关的生物大分子,参与了多种心血管系统的病理过程[1,2]。本文对血清心肌酶及脑钠肽前体对急性心肌梗死的临床诊断价值及患者预后相关性进行研     

蒽环类药物所致心脏毒性的磁共振研究进展

蒽环类药物(anthracycline, ATC)是常见的化疗药物,具有突出的心脏毒性。蒽环类药物所致心脏毒性(anthracycline-induced cardiotoxicity,AIC)是影响癌症患者生存质量的重要因素。准确检测及正确评估AIC能够为临床诊疗提供重要信息,降低癌症患者出现心血管并发症的风险。心脏磁共振(cardiac magnetic resonance,CMR)具有无创、可重复性好、空间分辨率高、多序列成像等优势,在AIC的基线评估及跟踪随访中起到了重要作用。近年来,包括特征追踪(feature-tracking,FT)技术及mapping技术在内的一系列CMR新技术的发展更是在AIC的早期检测方面发挥了重要的作用。本文将对CMR在检测和评估AIC中的应用及研究进展作一综述。     

2020年心脏MR研究进展

MRI因具有可多平面、多参数及多序列成像且无创、无辐射的优势而成为心血管疾病的重要影像学检查方法。近年来,随着MR硬件与软件的发展,心脏磁共振（CMR）已逐渐成为集诊断与鉴别、判断预后与危险分层等于一体的综合性评估手段,为临床决策所不可或缺。本文对2020年CMR领域的代表性成果进行综述。     

心血管磁共振成像机遇与挑战——中国十年来发展成果及展望

近十年来,心血管磁共振（cardiovascular magnetic resonance, CMR）成像技术作为一种无创性评估心脏结构与功能的“金标准”,已在国内心血管疾病临床诊疗领域发挥了重要作用。伴随着组织学特征成像、特征追踪技术、扩散加权成像、影像组学和人工智能等新技术的出现,CMR为心血管系统疾病精准诊疗提供了新的机遇。国内许多医院已经采用CMR对缺血性心脏病、非缺血性心脏病、大血管疾病等进行精准评估,取得了系列研究成果。相信未来CMR将在组织学特征成像、影像组学和人工智能、分子成像以及疾病的早期诊断、危险分层、预后评估等方面取得更大的研究成果。本文对十年来国内CMR领域临床和科研进展进行总结,并展望未来发展方向,以期为CMR技术研究与临床研究提供相关参考。     

心脏磁共振成像新技术进展与展望

心脏磁共振(cardiac magnetic resonance,CMR)已经成为评估心功能的"金标准"。常规CMR扫描技术相对成熟,在疾病诊断及预后评估中发挥了至关重要的作用。近年来定量成像技术(T1 Mapping、T2 Mapping、Feature tracking、4D Flow、DTI)及非对比剂增强(whole heart MR coronary angiography、ASL)等CMR新技术发展突飞猛进,潜能巨大,有望对心血管疾病的诊断及鉴别诊断提供重要帮助。     

T2-weighted cardiovascular magnetic resonance in acute cardiac disease

Cardiovascular magnetic resonance (CMR) using T2-weighted sequences can visualize myocardial edema. When compared to previous protocols, newer pulse sequences with substantially improved image quality have increased its clinical utility. The assessment of myocardial edema provides useful incremental diagnostic and prognostic information in a variety of clinical settings associated with acute myocardial injury. In patients with acute chest pain, T2-weighted CMR is able to identify acute or recent myocardial ischemic injury and has been employed to distinguish acute coronary syndrome (ACS) from non-ACS as well as acute from chronic myocardial infarction.T2-weighted CMR can also be used to determine the area at risk in reperfused and non-reperfused infarction. When combined with contrast-enhanced imaging, the salvaged area and thus the success of early coronary revascularization can be quantified. Strong evidence for the prognostic value of myocardial salvage has enabled its use as a primary endpoint in clinical trials. The present article reviews the current evidence and clinical applications for T2-weighted CMR in acute cardiac disease and gives an outlook on future developments."The principle of all things is water"Thales of Miletus (624 BC - 546 BC)     

Quantitative Tissue Characterization in Pediatric Cardiology

Purpose of Review

This review discusses the cardiovascular magnetic resonance (CMR) myocardial tissue characterization techniques and its applications with a focus on pediatric patients. Delayed enhancement CMR (DE-CMR) is well established to detect focal myocardial fibrosis in the clinical setting but has its limitation in detecting diffuse myocardial disease. Newer mapping techniques allow exact assessment of myocardial relaxation times and their changes in various cardiac pathologies.

Recent Findings

T1 mapping gives new insights in diffuse myocardial disease in pediatric patients with tetralogy of Fallot. T2 mapping seems to be superior to other CMR parameters for identifying myocarditis. Changes in myocardial T2* in thalassemia major can be detected in childhood suggesting that myocardial damage occurs early in life.

Summary

Advanced CMR mapping techniques underlie a rapid development and enable a noninvasive characterization of the myocardium. Although data for young patients are limited, mapping techniques have the potential to become key imaging tools in pediatric patients.

     

Cardiovascular magnetic resonance imaging to assess myocardial fibrosis in valvular heart disease

The left ventricular (LV) remodeling process associated with significant valvular heart disease (VHD) is characterized by an increase of myocardial interstitial space with deposition of collagen and loss of myofibers. These changes occur before LV systolic function deteriorates or the patient develops symptoms. Cardiovascular magnetic resonance (CMR) permits assessment of reactive fibrosis, with the use of T1 mapping techniques, and replacement fibrosis, with the use of late gadolinium contrast enhancement. In addition, functional consequences of these structural changes can be evaluated with myocardial tagging and feature tracking CMR, which assess the active deformation (strain) of the LV myocardium. Several studies have demonstrated that CMR techniques may be more sensitive than the conventional measures (LV ejection fraction or LV dimensions) to detect these structural and functional changes in patients with severe left-sided VHD and have shown that myocardial fibrosis may not be reversible after valve surgery. More important, the presence of myocardial fibrosis has been associated with lesser improvement in clinical symptoms and recovery of LV systolic function. Whether assessment of myocardial fibrosis may better select the patients with severe left-sided VHD who may benefit from surgery in terms of LV function and clinical symptoms improvement needs to be demonstrated in prospective studies. The present review article summarizes the current status of CMR techniques to assess myocardial fibrosis and appraises the current evidence on the use of these techniques for risk stratification of patients with severe aortic stenosis or regurgitation and mitral regurgitation.     

Cardiovascular magnetic resonance imaging of myocardial inflammation

Cardiovascular magnetic resonance (CMR) imaging can precisely quantify cardiac size and function, but moreover depict tissue changes that are associated with various forms of myocardial inflammation. Thereby, CMR can often detect myocardial inflammation before contractility is obviously impaired. Various CMR techniques to assess aspects of inflammation including T2-weighted imaging, and early- and late-contrast enhanced T1-weighted imaging, are reviewed regarding technical challenges and clinical usefulness. In this article we discuss the available evidence regarding clinical application of CMR in different forms of myocardial inflammation.     

CMR of microvascular obstruction and hemorrhage in myocardial infarction

Microvascular obstruction (MO) or no-reflow phenomenon is an established complication of coronary reperfusion therapy for acute myocardial infarction. It is increasingly recognized as a poor prognostic indicator and marker of subsequent adverse LV remodeling. Although MO can be assessed using various imaging modalities including electrocardiography, myocardial contrast echocardiography, nuclear scintigraphy, and coronary angiography, evaluation by cardiovascular magnetic resonance (CMR) is particularly useful in enhancing its detection, diagnosis, and quantification, as well as following its subsequent effects on infarct evolution and healing. MO assessment has become a routine component of the CMR evaluation of acute myocardial infarction and will increasingly play a role in clinical trials of adjunctive reperfusion agents and strategies. This review will summarize the pathophysiology of MO, current CMR approaches to diagnosis, clinical implications, and future directions needed for improving our understanding of this common clinical problem.     

Cardiovascular magnetic resonance imaging of myocardial inflammation

Cardiovascular magnetic resonance (CMR) imaging can precisely quantify cardiac size and function, but moreover depict tissue changes that are associated with various forms of myocardial inflammation. Thereby, CMR can often detect myocardial inflammation before contractility is obviously impaired. Various CMR techniques to assess aspects of inflammation including T2-weighted imaging, and early- and late-contrast enhanced T1-weighted imaging, are reviewed regarding technical challenges and clinical usefulness. In this article we discuss the available evidence regarding clinical application of CMR in different forms of myocardial inflammation.     

Assessment of coronary artery disease with a combined magnetic resonance examination

Cardiovascular magnetic resonance (CMR) imaging provides morphological and functional data relevant to the assessment of coronary artery disease (CAD). A wide range of such data can be acquired in a single multiparametric imaging session. In stable CAD, a combined CMR examination comprising assessment of cardiac function, perfusion, and myocardial viability can be used to detect the presence of CAD and to determine the appropriateness of coronary revascularization. In acute coronary syndromes, a combined CMR examination can be used for the differential diagnosis of myocarditis and other acute cardiac disease, for risk-stratification of patients after myocardial infarction and for the targeted assessment of complications of myocardial infarction. This article overviews the CMR methods that are available for assessment of CAD and describes situations when combined CMR examinations can play a role in its diagnosis and differential diagnosis.     

The emerging role of cardiovascular magnetic resonance in the evaluation of Kawasaki disease

Kawasaki disease (KD) is a vasculitis affecting the coronary and systemic arteries. Myocardial inflammation is also a common finding in KD post-mortem evaluation during the acute phase of the disease. Coronary artery aneurysms (CAAs) develop in 15–25 % of untreated children. Although 50–70 % of CAAs resolve spontaneously 1–2 years after the onset of KD, the remaining unresolved CAAs can develop stenotic lesions at either their proximal or distal end and can develop thrombus formation leading to ischemia and/or infarction. Cardiovascular magnetic resonance (CMR) has the ability to perform non-invasive and radiation-free evaluation of the coronary artery lumen. Recently tissue characterization of the coronary vessel wall was provided by CMR. It can also image myocardial inflammation, ischemia and fibrosis. Therefore CMR offers important clinical information during the acute and chronic phase of KD. In the acute phase, it can identify myocardial inflammation, microvascular disease, myocardial infarction, deterioration of left ventricular function, changes of the coronary artery lumen and changes of the coronary artery vessel wall. During the chronic phase, CMR imaging might be of value for risk stratification and to guide treatment.     

Adjunctive role of cardiovascular magnetic resonance in the assessment of patients with inferior attenuation on myocardial perfusion SPECT.

PURPOSE: Inferior attenuation is a common problem in the interpretation of myocardial perfusion SPECT. We explored whether cardiovascular magnetic resonance (CMR) was a useful adjunct in differentiating between artifactual attenuation of the inferior wall and the presence of myocardial infarction and/or ischemia. METHODS: We used CMR to assess resting wall motion, myocardial perfusion, and the presence of infarction with late gadolinium enhancement in 30 patients with presumed inferior attenuation on ungated myocardial perfusion SPECT, but where uncertainty was present over interpretation of the inferior wall. Perfusion CMR was analyzed visually and quantitatively. RESULTS: In 23 patients (77%), CMR excluded infarction or ischemia in the inferior wall. The myocardial perfusion reserve index (MPR1) was the same in the inferior and remote myocardium (1.74 +/- 0.43 vs. 1.77 +/- 0.50, p = 0.61). Coronary angiography was performed in 11 of these patients, and was normal in all cases. In the remaining seven subjects (23%), significant abnormality was detected by CMR (infarction, 5; wall motion abnormality, 3; perfusion defect, 5). In these patients, the MPR1 was reduced in the inferior myocardium compared with remote (1.07 +/- 0.19 vs. 1.74 +/- 0.49, p = 0.04). Coronary angiography was performed in three of these patients, revealing significant coronary disease in the artery supplying the inferior territory in all patients. CONCLUSION: Approximately one-quarter of patients with inferior attenuation on ungated, nonattenuation corrected myocardial perfusion SPECT have abnormalities on CMR. CMR can readily distinguish between artifact, ischemia, and infarction in these cases and in some cases might obviate the need for diagnostic coronary angiography.