目的 探讨新路易斯湖标准（LLC）在儿童心肌炎诊断中的应用价值。方法 回顾性分析2019年5月至2020年12月在浙江大学医学院附属儿童医院确诊为心肌炎患儿（心肌炎组）的临床资料，另纳入同期临床排除心肌炎的患儿为非心肌炎组。通过受试者工作特征曲线（ROC）分析，计算Kappa值等比较LLC与新LLC对儿童心肌炎的诊断效能。结果 心肌炎组29例，男16例、女13例，中位年龄8.8（4.2~13.4）岁。非心肌炎组50例，男27例、女23例，中位年龄9.7（6.2~13.2）岁。心肌炎组T2 mapping值、T1 native值、细胞外间质容积（ECV）均大于非心肌炎组，T1 enhanced值小于非心肌炎组，差异有统计学意义（P<0.05）。LLC、T2 mapping、T1 native、T1 enhanced、ECV值诊断心肌炎的ROC曲线下面积（AUC）分别为0.75、0.86、0.92、0.70、0.93。LLC诊断心肌炎的准确度为81.0%，灵敏度51.7%，特异度98.0%，阳性预测值93.8%，阴性预测值77.8%，阳性似然比25.85，阴性似然比0.49，LLC与临床诊断结果比较，一致性中等（Kappa=0.55，P<0.001）；新LLC诊断心肌炎的准确度92.4%，灵敏度89.7%，特异度94.0%，阳性预测值89.7%，阴性预测值94.0%，阳性似然比14.95，阴性似然比0.11，新LLC与临床诊断结果比较，一致性较好（Kappa=0.84，P<0.001）。结论 新LLC在儿童心肌炎的诊断中有较好的应用价值，可有效提高诊断效能。

Objective To explore the application value of new Lake Louise criteria (LLC) in the diagnosis of myocarditis in children. Methods The clinical data of children diagnosed with myocarditis (myocarditis group) in Children's Hospital Affiliated to Zhejiang University School of Medicine from May 2019 to December 2020 were retrospectively analyzed. In addition, children who were clinically excluded from myocarditis during the same period were included as non-myocarditis group. Receiver operating characteristic (ROC) curve analysis and calculation of Kappa value were used to compare the diagnostic efficacy of LLC and new LLC in children with myocarditis. Results In the myocarditis group, there were 29 children (16 boys and 13 girls) with a median age of 8.8 (4.2-13.4) years. There were 50 patients (27 boys and 23 girls) in the non-myocarditis group, and the median age was 9.7 (6.2-13.2) years. The T2 mapping value, T1 native value and ECV value of myocarditis group were higher than those of non-myocarditis group, the T1 enhanced value was lower than that of non-myocarditis group, and the difference was statistically significant (P<0.05). The area under ROC curves (AUCs) of LLC, T2 mapping, T1 native, T1 enhanced and ECV for diagnosing myocarditis were 0.75, 0.86, 0.92, 0.70 and 0.93, respectively. The accuracy, sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio and negative likelihood ratio of LLC in diagnosing myocarditis were 81.0%, 51.7%, 98.0%, 93.8%, 77.8%, 25.85 and 0.49 respectively. The consistency between LLC and the clinical diagnosis of myocarditis was moderate (Kappa=0.55, P<0.001). The accuracy, sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio and negative likelihood ratio of new LLC in diagnosing myocarditis were 92.4%, 89.7%, 94.0%, 89.7%, 94.0%, 14.95 and 0.11 respectively. The consistency between new LLC and the clinical diagnosis of myocarditis was good (Kappa=0.84, P<0.001). Conclusions The new LLC has good application value in the diagnosis of myocarditis in children and can effectively improve the diagnostic efficiency.