心肌炎患儿心脏磁共振成像检测的临床意义

摘要

目的 评价心脏磁共振成像(CMR)检测对心肌炎患儿的意义.方法 选取2011年4月至2015年5月在首都医科大学附属北京安贞医院就诊的有心肌损害症状的患儿50例,均行CMR检查,根据心肌炎临床诊断标准分为临床诊断心肌炎组(29例)及心肌损害组(21例),分别对2组心肌成像特点及心肌肌钙蛋白(cTnI)、肌酸激酶同工酶(CK-MB)指标变化进行统计分析.结果 29例心肌炎组患儿CMR均可见阳性表现,13例符合CMR诊断心肌炎标准;16例不符合CMR诊断心肌炎标准,其中13例患儿(病程均＜1个月)CMR可见T2增强信号,1例(病程＞1个月)早期对比增强,2例(1例病程＜1个月)延迟对比增强.21例心肌损害组患儿中17例CMR可见阳性表现,4例符合CMR诊断心肌炎标准;17例不符合CMR诊断心肌炎标准,其中9例患儿(7例病程＜1个月)CMR可见T2信号增强,4例(2例病程＜1个月)延迟对比增强,4例CMR无异常改变.T2信号增强提示心肌存在水肿,符合心肌炎早期改变;早期对比增强提示心肌组织出现毛细血管渗漏或纤维化;延迟对比增强提示心肌坏死或纤维化.心肌炎组CMR阳性率高于心肌损害组[100.0％(29/29)比81.0％(17/21)],差异有统计学意义(P＜0.05),2组符合CMR诊断心肌炎标准的阳性率比较[44.8％ (13/29)比19.0％ (4/21)],差异无统计学意义(P＞0.05).心肌炎组cTnI阳性率明显高于心肌损害组[69.0％(20/29)比28.6％ (6/21)],差异有统计学意义(P＜0.05),CK-MB阳性率比较[41.4％ (12/29)比19.0％ (4/21)],差异无统计学意义(P＞0.05).心肌炎组符合CMR诊断心肌炎标准的阳性率与cTnI阳性率和CK-MB阳性率比较,差异均无统计学意义(均P＞0.05),cTnI阳性率与CK-MB阳性率比较,差异有统计学意义(P＜0.01).结论 CMR可动态、直观地呈现心肌组织的病理改变,判断心肌炎的严重程度更为准确,更利于指导治疗、判断预后.%Objective To evaluate the signification of cardiac magnetic resonance (CMR) imaging in diagnosing myocarditis in children.Methods Totally 50 patients with myocardial damage symptoms who underwent CMR from April 2011 to May 2015 were retrospectively analyzed.According to the clinical diagnosis criteria of myocarditis, the children were divided into myocarditis group (29 cases) and myocardial damage group (21 cases).The imaging features and biochemical data, including cardiac troponin Ⅰ (cTNI) and creatine kinase MB (CK-MB), were compared between groups.Results CMR of myocarditis group showed positive performance, 13 cases accorded with CMR diagnosis criterion of myocarditis and the other 16 cases did not [hyperintense on T2 image was observed in 13 cases (course ＜ 1 month), early phase contrast enhancement signal was observed in 1 case (course ＞ 1 month), delayed contrast enhancement signal was oberved in 2 cases (course ＜ 1 month)].In myocardial damage group, 17 cases showed positive CMR performance, among them 4 cases accorded with CMR diagnosis criterion of myocarditis and the other 17 cases did not [hyperintense on T2 image was observed in 9 cases (course ＜ 1 month 7 cases) , delayed contrast enhancement signal was observed in 2 cases (course ＜ 1 month in 2 cases), no abnormity was found in 4 cases].The hyperintense on T2 image suggested myocardial edema, according with early changes of myocarditis, early phase contrast enhancement suggested capillary leakage or fibrosis of myocardial;delayed contrast enhancement suggested necrosis or fibrosis of myocardial.The rate of positive performance was significantly different between myocarditis group and myocardial damage group [100.0％ (29/29) vs 81.0％ (17/21)] (P ＜ 0.05);the CMR diagnosis rate showed no significant difference between groups [44.8％ (13/29) vs 19.0％ (4/21)] (P ＞ 0.05).In myocarditis group, the CMR diagnosis rate was not significantly different with the positive rate of cTnI and CK-MB (P ＞ 0.05);the positive rate of cTnI was significantly higher than that of CK-MB (P ＜ 0.01).Conclusion CMR can dynamically and visually detect the pathological changes of myocardial tissue, thus is beneficial to assessment of the severity of myocarditis.