From the Center for Chronically Sick Children (C.A.H., S.W.), Departments of Radiology (H.T., J.G., B.H., I.S.), Pathology (B.R., H.B., C.L.), Pediatric Gastroenterology (W.L.), and Gastroenterology and Hepatology (H.P.M., D.C.B.), and the Institutes for Medical Informatics (J.B.) and Biochemistry (H.G.H.), Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany.
Radiology. 2018 Jul;288(1):99-106. doi: 10.1148/radiol.2018172928. Epub 2018 May 15.
Purpose To measure in vivo liver stiffness by using US time-harmonic elastography in a cohort of pediatric patients who were overweight to extremely obese with nonalcoholic fatty liver disease (NAFLD) and to evaluate the diagnostic value of time-harmonic elastography for differentiating stages of fibrosis associated with progressive disease. Materials and Methods In this prospective study, 67 consecutive adolescents (age range, 10-17 years; mean body mass index, 34.7 kg/m; range, 21.4-50.4 kg/m) with biopsy-proven NAFLD were enrolled. Liver stiffness was measured by using time-harmonic elastography based on externally induced continuous vibrations of 30 Hz to 60 Hz frequency and real-time B-mode-guided wave profile analysis covering tissue depths of up to 14 cm. The diagnostic accuracy of time-harmonic elastography in staging liver fibrosis was assessed with area under the receiver operating characteristic curve (AUC) analysis. Liver stiffness cutoffs for the differentiation of fibrosis stages were identified based on the highest Youden index. Results Time-harmonic elastography was feasible in all patients (0% failure rate), including 70% (n = 47) of individuals with extreme obesity (body mass index above the 99.5th percentile). AUC analysis for the detection of any fibrosis (≥ stage F1), moderate fibrosis (≥ stage F2), and advanced fibrosis (≥ stage F3) was 0.88 (95% confidence interval [CI]: 0.80, 0.96), 0.99 (95% CI: 0.98, 1.00), and 0.88 (95% CI: 0.80, 0.96), respectively. The best liver stiffness cutoffs were 1.52 m/sec for at least stage F1, 1.62 m/sec for at least stage F2, and 1.64 m/sec for at least stage F3. Conclusion US time-harmonic elastography allows accurate detection of moderate fibrosis even in pediatric patients with extreme obesity. Larger clinical trials are warranted to confirm the accuracy of US time-harmonic elastography.
利用超声时间谐波弹性成像技术测量超重至极度肥胖的非酒精性脂肪性肝病（NAFLD）患儿的肝脏硬度，并评估时间谐波弹性成像技术对鉴别与疾病进展相关的纤维化分期的诊断价值。
本前瞻性研究纳入了 67 例经活检证实为 NAFLD 的青少年患者（年龄 10-17 岁；平均体重指数 34.7kg/m²；范围 21.4-50.4kg/m²）。采用基于外部 30Hz 至 60Hz 连续振动的时间谐波弹性成像技术，结合实时 B 型超声引导波谱分析，测量肝脏硬度，可探测深度达 14cm。采用受试者工作特征曲线下面积（AUC）分析评估时间谐波弹性成像技术在肝纤维化分期中的诊断准确性。根据最高 Youden 指数确定区分纤维化分期的肝硬度截断值。
所有患者（0%失败率）均可行时间谐波弹性成像，包括 70%（n=47）极度肥胖（体重指数超过第 99.5 百分位数）的个体。检测任何纤维化（≥F1 期）、中度纤维化（≥F2 期）和进展性纤维化（≥F3 期）的 AUC 分析分别为 0.88（95%置信区间：0.80，0.96）、0.99（95%置信区间：0.98，1.00）和 0.88（95%置信区间：0.80，0.96）。最佳肝硬度截断值分别为至少 F1 期 1.52m/sec、至少 F2 期 1.62m/sec 和至少 F3 期 1.64m/sec。
超声时间谐波弹性成像技术可准确检测到中度纤维化，即使在极度肥胖的儿科患者中也是如此。需要更大的临床试验来证实超声时间谐波弹性成像技术的准确性。
