目的 探讨实时剪切波弹性成像(SWE)在定量评价肥胖儿童脂肪肝中的价值,为肥胖儿童脂肪肝的早期诊断、干预和治疗提供更多依据。方法 选取2018年4月-2020年4月西安交通大学第二附属医院儿童青少年肥胖门诊就诊的331例肥胖脂肪肝儿童(脂肪肝组)及100例正常儿童(对照组),以临床诊断为参考标准,分别对两组儿童应用实时剪切波弹性成像测量其肝脏的剪切波速度(SWV)及杨氏模量值(EI),比较两组间的差异,绘制ROC曲线,确定肥胖儿童脂肪肝的最佳诊断界点值。并记录受检儿童一般资料,收集相关血液生化检测结果,比较肥胖脂肪肝儿童SWV值和EI值与临床指标的相关性。结果 肥胖脂肪肝儿童组与正常儿童组在年龄、身高以及丙氨酸转氨酶方面的差异无统计学意义(P>0.05);而在体重、体重指数、腰臀比、血清总胆固醇、甘油三酯方面的差异有统计学意义(t＝3.681、4.010、4.587、3.562、7.015,P<0.05)。脂肪肝组SWV测值为(1.83±0.24)m/s,显著高于对照组(1.01±0.19)m/s,通过绘制ROC曲线确定肥胖儿童脂肪肝SWV的最佳诊断界点值为1.35m/s,灵敏度0.94,特异度0.81,ROC 曲线下面积0.932;脂肪肝组EI测值为(7.11±0.39) kPa,显著高于对照组(5.94±0.26) kPa,通过绘制ROC曲线确定肥胖儿童脂肪肝EI的最佳诊断界点值为6.32 kPa,灵敏度0.96,特异度0.72,ROC曲线下面积0.879。肥胖脂肪肝儿童SWV值和EI值均与体重、体重指数、腰臀比、总胆固醇、血清甘油三酯呈正相关(r_SWV=0.401、0.450、0.488、0.352、0.697, r_EI=0.377、0.463、0.501、0.331、0.611,P<0.05)。结论 实时剪切波弹性成像能够准确无创的定量评价肥胖儿童的脂肪肝情况,对肥胖儿童脂肪肝的早期诊断、干预和治疗具有重要的意义。

Objective To analyze the value of real-time shear wave elastography (SWE) in the quantitative evaluation of fatty liver in obese children, so as to provide more evidence for early diagnosis, intervention and treatment of obese children with fatty liver. Methods From April 2018 to April 2020, a total of 331 obese children who visited the Children and Adolescents Obesity Clinic in the Second Affiliated Hospital of Xi′an Jiaotong University were selected as fatty liver group.Meanwhile, 100 healthy children were selected as control group.Using clinical diagnosis as the reference standard, the shear wave velocity (SWV) and young′s modulus value (EI) of the liver in two groups of children were measured using real-time shear wave elastography, and the difference was compared.ROC curve was then drew to determine the optimal cut-off value for fatty liver in obese children.Additionally, the general data of children were recorded, and the relevant blood biochemical test results were collected to compare the correlation between SWV value, EI value and clinical indicators in children with fatty liver disease. Results There were no statistically significant differences in age, height and alanine amino transferase between obese children and normal children (P>0.05).But the differences in body weight, body mass index(BMI), waist-hip ratio, total cholesterol and serum triglycerides between the two groups were statistically significant (t=3.681, 4.010, 4.587, 3.562, 7.015, P<0.05).The SWV value of the fatty liver group was (1.83±0.24)m/s, significantly higher than that of the control group [(1.01±0.19)m/s].ROC curve indicated that the best diagnostic cut-off point for SWV in obese children with fatty liver was 1.35m/s, the sensitivity and specificity was 0.94 and 0.81, respectively, and the area under the ROC curve was 0.932.The EI value of the fatty liver group was (7.11±0.39)kPa, significantly higher than that in the control group [(5.94±0.26)kPa].ROC curve indicated that the optimal diagnostic cut-off value of EI in obese children with fatty liver was 6.32 kPa, the sensitivity and specificity was 0.96 and 0.72, respectively, and the area under the ROC curve was 0.879.Both SWV and EI values were positively correlated with body weight, and BMI, waist-hip ratio, total cholesterol and serum triglyceride (r_SWV=0.401,0.450,0.488,0.352,0.697; r_EI=0.377,0.463,0.501,0.331,0.611,P<0.05). Conclusion Real-time shear wave elastography can accurately and noninvasively identify the degree of fatty liver in obese children, which is of great significance for the early diagnosis, intervention and treatment of fatty liver in obese children.