基于CMR mapping及ECV技术对心肌炎心肌活性机制及病理演变的研究

It is very important of myocardial viability assessment for the diagnosis and clinical phase definition of myocarditis, which direct clinical management and prognosis. New CMR mapping and ECV techniques become promising tool for quantitive and qualitative myocardial injury, especially for whole heart tissue evaluation. However, the mechanism of CMR mapping and ECV evaluation of myocardial viability in myocarditis is still not clear. The aim of the present study was to explore the relationship between quantitive T1 mapping/ECV and myocardial viability, to elucidate the change pattern of T1 mapping and ECV with time window, and to discover the the physiopathologic changes during progression of myocarditis in experimental autoimmune myocarditis (EAM) in rat model. At the same time, we wanted to reveal the physiopathologic changes during progression of acute myocarditis and the relationship between CMR index and biochemical indicator.. The study will provide a theoretical basis to comprehensive CMR evaluation of CMR mapping and ECV acquisition time window for clinical myocarditis and criteria of myocardial activity judgemet. Further, It will provide a noninvasive robust tool for myocardial diagnosis and follow-up with high accuracy and promote the utility of CMR protocol for myocarditis..

心肌活性的评价对心肌炎的诊断和临床分期至关重要,对治疗方案的选择和预后有重要意义。CMR mapping及ECV技术，可定性、定量检测心肌组织学改变，观察全心肌病理改变,但是其反映心肌炎心肌活性的机制仍不明确。本研究拟通过建立大鼠心肌炎模型，探讨大鼠心肌定量T1 mapping及ECV与心肌活性的相关性；阐明心肌活性程度与T1 mapping及ECV采集时间窗变化规律，揭示急、慢性心肌炎病理演变过程。在动物实验研究的基础上，应用3.0T CMR mapping及ECV技术对急性心肌炎动态观察，结合临床生化指标，揭示心肌炎病理演变过程及与临床生化指标的相关性。从而为CMR综合评估临床心肌炎心肌活性判定标准提供理论依据。本研究将提供一种高效、无创性心肌炎和病程分期的方法，提高CMR对心肌炎诊断和随访的能力。

背景：心肌炎可导致心肌细胞坏死，炎症细胞浸润及随后发生的心肌纤维化，其临床表现为短暂的疲劳、急性胸痛，严重时可引起心脏衰竭或心源性猝死。本研究以T1mapping、T2mapping作为组织特征成像工具，采用多参数心脏磁共振成像方法，评价心脏磁共振成像在疑似急性心肌炎患者中的诊断价值。方法：本研究纳入两个中心共计50例急性心肌炎患者，100例对照受试者。心脏磁共振成像方法包括三反转黑血T2、钆早期增强、钆延迟强化、初始T1弛豫时间、初始T2弛豫时间和细胞外容积分数。通过受试者工作特征曲线对诊断性能进行了比较，以急性心肌炎的临床证据作为参考标准。结果：路易斯湖标准、T1值、T2值、ECV值的诊断准确性分别为85%, 86%, 69%和78%。路易斯湖标准诊断的曲线下面积为0.87，敏感性为92%，特异性为81%；初始T1诊断的曲线下面积为0.909，敏感性为88%，特异性为85%（截断值为1256ms）；初始T2诊断的曲线下面积为0.679，敏感性为78%，特异性为65%（截断值为44.2ms）；ECV诊断的曲线下面积为0.817，敏感性为72%，特异性为81%（截断值为28.1%）。 结论：初始T1的诊断性能优于初始T2和ECV，该技术的特异性也高于路易斯湖标准。初始T1弛豫时间作为对现有心脏磁共振技术的补充，其在疑似急性心肌炎患者的诊断中具有很高的价值。