心脏磁共振在肥厚型心肌病预后评估及危险分层中的应用进展

肥厚型心肌病(hypertrophic cardiomyopathy,HCM)是最常见的遗传性原发型心肌病,也是青年人猝死的最常见原因.心脏磁共振(cardiovascular magnetic resonance,CMR)多参数、多模态成像,能从多个方面综合评估患者心脏受累程度,从而为HCM患者危险分层及预后评估提供...     

T1 mapping技术用于心脏疾病危险分层及预后评估研究进展

近年心脏MR(CMR)技术快速发展,在心脏疾病中的应用越来越受到重视。T1 mapping成像技术可量化评价心肌组织T1弛豫时间,在评价心肌组织学特征和定量分析方面具有较大潜力,可为判断多种心脏疾病的预后提供有价值的信息。本文就T1 mapping技术在心脏疾病危险分层及预后评估中的研究进展进行综述。     

心脏磁共振技术在扩张型心肌病中的研究进展

扩张型心肌病(dilated cardiomyopathy,DCM)是一种心室腔扩大并收缩功能障碍、不可逆性的心肌疾病,常合并心律失常、猝死等并发症,预后不良。随着心脏磁共振(cardiac magnetic resonance,CMR)技术的应用,不仅可用于观察DCM患者的心脏功能及心肌细微结构的改变,而且还能评价心肌活性及心肌纤维化,对DCM的诊断及预后评价具有极其重要的作用。本文就CMR技术在DCM中的应用及研究进展予以综述。     

心肌纤维化心脏磁共振及在糖尿病心肌病的应用进展

糖尿病心肌病(diabetic cardiomyopathy, DbCM)早期采取干预措施,能够阻止甚至逆转DbCM改变,预防心脏结构的重塑并改善心脏舒张功能,因此,通过对心脏功能、心肌微循环灌注状态和心肌纤维化的检测评估,实现对DbCM精确诊断、危险分级及预后评估具有重要的临床意义。心脏磁共振(cardiac magnetic resonance, CMR)具有良好的软组织分辨率和多序列、多参数成像的优势,不仅可以准确评估心脏解剖结构和功能改变,还能够无创性观察心肌的组织学特征,对心肌纤维化的精确诊断及危险分级具有重要临床价值。本文就MR心肌延迟强化、T1 mapping、T2 mapping、扩散张量成像及T1ρ mapping技术在心肌纤维化临床应用的前沿进展予以综述,并展望未来该技术的发展应用。     

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。     

心脏磁共振成像在妊娠合并心脏疾病中的应用研究进展

心脏疾病导致怀孕的风险升高。女性妊娠期的特征是多器官、多系统的变化,诊断过程中要考虑胎儿的安全。心脏磁共振(CMR)成像具有无辐射、无创伤等优势,不仅能够很好地显示心脏结构、功能、心肌组织特征、血流、心肌瘢痕及纤维化灶,而且可以对疾病的危险分层、预后等提供依据。目前,CMR在先天性心脏病、心脏瓣膜病、冠状动脉疾病、心肌病等心血管疾病中发挥着越来越重要的作用。本研究对CMR在妊娠合并心脏疾病女性中的应用进展进行综述。     

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MRI评估心肌梗死病理变化的研究进展

心肌梗死是缺血性心脏病的重要临床特征,且其各阶段病理组织学改变均与患者预后密切相关。近年来,随着MRI软硬件技术的不断发展和完善,心脏MR （CMR）凭借多参数、多序列的成像技术特点,可定性、定量评估心肌梗死的相关病理变化,并可为患者的近期诊断及远期预后风险评估提供准确、全面的临床参考信息。本文就CMR在评估心肌梗死病理中的应用及研究进展进行综述。     

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。     

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。     

心脏磁共振成像在高血压性心脏病左心室评价中的研究进展

高血压性心脏病是全球范围最常见的慢性疾病之一,以左心室结构及功能变化为特征性表现,主要包括心脏舒张功能障碍,左心室肥厚及弥漫性心肌纤维化。心脏磁共振成像作为一种无创性影像学检查方法,在心血管疾病诊疗中发挥着重要作用。作者就心脏磁共振成像在评价高血压性心脏病的左心室心功能、心脏重塑、心肌纤维化、心外膜脂肪组织及预后评估的研究进展进行综述。     

Nontransmural Scar Detected by Magnetic Resonance Imaging and Origin of Ventricular Tachycardia in Structural Heart Disease

Background: Contrast-enhanced magnetic resonance imaging (CMR) identifies scar tissue as an area of delayed enhancement (DE). The scar region might be the substrate for ventricular tachycardia (VT). However, the relationship between the occurrence of VT and the characteristics of scar tissue has not been fully studied.
Methods: CMR was performed in 34 patients with monomorphic, sustained VT and dilated cardiomyopathy (DCM, n = 18), ischemic cardiomyopathy (ICM, n = 10), or idiopathic VT (IVT, n = 6). The VT exit site was assessed by a detailed analysis of the QRS morphology, including bundle branch block type, limb lead polarity, and precordial R-wave transition. On CMR imaging, the transmural score of each of the 17 segments was assigned, using a computer-assisted, semiautomatic technique, to measure the DE areas. Segmental scars were classified as nontransmural when DE was 1–75% and transmural when DE was 76–100% of the left ventricular mass in each segment.
Results: A scar was detected in all patients with DCM or ICM. Nontransmural scar tissue was often found at the VT exit site, in patients with DCM or ICM. In contrast, no scar was found in patients with IVT.
Conclusions: CMR clarified the characteristics and distribution of scar tissue in patients with structural heart disease, and the presence and location of scar tissue might predict the VT exit site in these patients.     

Frontiers of COVID-19-related myocarditis as assessed by cardiovascular magnetic resonance

Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. In some patients, COVID-19 is complicated with myocarditis. Early detection of myocardial injury and timely intervention can significantly improve the clinical outcomes of COVID-19 patients. Although endomyocardial biopsy (EMB) is currently recognized as the ‘gold standard’ for the diagnosis of myocarditis, there are large sampling errors, many complications and a lack of unified diagnostic criteria. In addition, the clinical methods of treating acute and chronic COVID-19-related myocarditis are different. Cardiac magnetic resonance (CMR) can evaluate the morphology of the heart, left and right ventricular functions, myocardial perfusion, capillary leakage and myocardial interstitial fibrosis to provide a noninvasive and radiation-free diagnostic basis for the clinical detection, efficacy and risk assessment, and follow-up observation of COVID-19-related myocarditis. However, for the diagnosis of COVID-19-related myocarditis, the Lake Louise Consensus Criteria may not be fully applicable. COVID-19-related myocarditis is different from myocarditis related to other viral infections in terms of signal intensity and lesion location as assessed by CMR, which is used to visualize myocardial damage, locate lesions and quantify pathological changes based on various sequences. Therefore, the standardized application of CMR to timely and accurately evaluate heart injury in COVID-19-related myocarditis and develop rational treatment strategies could be quite effective in improving the prognosis of patients and preventing potential late-onset effects in convalescent patients with COVID-19.     

Brain and heart magnetic resonance imaging/spectroscopy in duchenne muscular dystrophy

Duchenne muscular dystrophy (DMD) is an X‐linked muscle disorder characterized by progressive and irreversible loss of muscular function. As muscular disease progresses, the repair mechanisms cannot compensate for cellular damage, leading inevitably to necrosis and progressive replacement by fibrous and fatty tissue. Cardiomyopathy and respiratory failure are the main causes of death in DMD. In addition to the well‐described muscle and heart disease, cognitive dysfunction affects around 30% of DMD boys. Myocardial fibrosis, assessed by late gadolinium enhancement (LGE), using cardiovascular magnetic resonance imaging (CMR), is an early marker of heart involvement in both DMD patients and female carriers. In parallel, brain MRI identifies smaller total brain volume, smaller grey matter volume, lower white matter fractional anisotropy and higher white matter radial diffusivity in DMD patients. The in vivo brain evaluation of mdx mice, a surrogate animal model of DMD, showed an increased inorganic phosphate (P(i))/phosphocreatine (PCr) and pH. In this paper, we propose a holistic approach using techniques of magnetic resonance imaging, spectroscopy and diffusion tensor imaging as a tool to create a “heart and brain imaging map” in DMD patients that could potentially facilitate the patients’ risk stratification and also future research studies in the field.     

心脏MRI在射血分数保留型心力衰竭中的应用进展

近年来，以舒张功能障碍（DD）为主要特征的射血分数保留型心力衰竭（HFpEF）逐渐引起临床重视，作为高空间分辨率、高信噪比的非侵入性"一站式"检查方式，心脏MRI（CMR）对评估左心室舒张功能具有重要价值。本文就CMR及其早期识别和评估HFpEF患者DD的应用进展进行综述。     

The role of cardiovascular magnetic resonance in the evaluation of patients with heart failure

Chronic heart failure is a common disorder placing significant burdens on patients and health-care services. Noninvasive imaging plays a central role in accurate diagnosis, determination of etiology and prognosis, and in monitoring therapy. Advances in technology mean cardiovascular magnetic resonance (CMR) imaging has established itself as both a valuable clinical and research tool in this arena. Not only is CMR the new gold standard for accurate and reproducible assessment of ventricular volumes and mass, but by using gadolinium contrast, underlying pathology can often be determined. In ischemic cardiomyopathy a 'one stop' assessment can be made of function, perfusion and mass. Continuing advances such as myocardial tagging and the increasing availability of CMR mean that it will become an increasingly important and useful tool for clinicians looking after patients with cardiomyopathy and heart failure.     

The Characteristics and Distribution of the Scar Tissue Predict Ventricular Tachycardia in Patients with Advanced Heart Failure

Background: Contrast‐enhanced magnetic resonance imaging (CMR) identifies scar tissue as hyperenhanced areas. We sought to clarify the relationship between the scar characteristics and occurrence of sustained ventricular tachycardia (VT) in patients with advanced heart failure. Methods: CMR was performed in 29 patients with dilated cardiomyopathy (DCM group) and 18 patients with ischemic cardiomyopathy (ICM group). The characteristics, volume, and distribution of the hyperenhanced areas were analyzed by CMR. The CMR parameters and clinical arrhythmic events were compared between the two groups. Results: In the DCM group, almost all hyperenhanced areas were nontransmural, and presented frequently in the midwall layer. The volume of the hyperenhanced areas and total number of hyperenhanced segments were greater in patients with sustained VT than in those without. On the other hand, in the ICM group, transmural or subendocardial hyperenhanced areas were detected in the territory of the coronary arteries. The volume of the hyperenhanced areas and total number of transmural hyperenhanced segments in patients with sustained VT were unexpectedly smaller than in those without. However, the percentage of nontransmural hyperenhanced segments was greater in patients with sustained VT than in those without. Conclusions: The presence and magnitude of the nontransmural scar tissue may predict sustained VT in patients with advanced heart failure. There was the possibility that a recruitment bias was responsible for the finding of the smaller scars in the ICM patients with sustained VT.     

Prevalence of scarred and dysfunctional myocardium in patients with heart failure of ischaemic origin: A cardiovascular magnetic resonance study

Background

Cardiovascular magnetic resonance (CMR) with late gadolinium enhancement (LGE) can provide unique data on the transmural extent of scar/viability. We assessed the prevalence of dysfunctional myocardium, including partial thickness scar, which could contribute to left ventricular contractile dysfunction in patients with heart failure and ischaemic heart disease who denied angina symptoms.

Methods

We invited patients with ischaemic heart disease and a left ventricular ejection fraction < 50% by echocardiography to have LGE CMR. Myocardial contractility and transmural extent of scar were assessed using a 17-segment model.

Results

The median age of the 193 patients enrolled was 70 (interquartile range: 63-76) years and 167 (87%) were men. Of 3281 myocardial segments assessed, 1759 (54%) were dysfunctional, of which 581 (33%) showed no scar, 623 (35%) had scar affecting ≤50% of wall thickness and 555 (32%) had scar affecting > 50% of wall thickness. Of 1522 segments with normal contractile function, only 98 (6%) had evidence of scar on CMR. Overall, 182 (94%) patients had ≥1 and 107 (55%) patients had ≥5 segments with contractile dysfunction that had no scar or ≤50% transmural scar suggesting viability.

Conclusions

In this cohort of patients with left ventricular systolic dysfunction and ischaemic heart disease, about half of all segments had contractile dysfunction but only one third of these had > 50% of the wall thickness affected by scar, suggesting that most dysfunctional segments could improve in response to an appropriate intervention.