Department of Radiological Sciences, Oncology and Pathology, Sapienza University of Rome, Rome, Italy.
Department of Experimental Medicine, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185, Rome, Italy.
Pediatr Radiol. 2023 Nov;53(12):2458-2465. doi: 10.1007/s00247-023-05749-9. Epub 2023 Sep 12.
Biopsy remains the gold standard for the diagnosis of hepatic steatosis, the leading cause of pediatric chronic liver disease; however, its costs call for less invasive methods.
This study examined the diagnostic accuracy and reliability of quantitative ultrasound (QUS) for the assessment of liver fat content in a pediatric population, using magnetic resonance imaging proton density fat fraction (MRI-PDFF) as the reference standard.
We enrolled 36 patients. MRI-PDFF involved a 3-dimensional T2*-weighted with Dixon pulse multiple-echo sequence using iterative decomposition of water and fat with echo asymmetry and least squares estimation (IDEAL IQ). QUS imaging relied on the ultrasound system "RS85 A" (Samsung Medison, Seoul, South Korea) and the following software: Hepato-Renal Index with automated region of interest recommendation (EzHRI), Tissue Attenuation Imaging (TAI), and Tissue Scatter Distribution Imaging (TSI). For each QUS index, receiver operating characteristic (ROC) curve analysis against MRI-PDFF was used to identify the associated cut-off value and the area under the ROC curve (AUROC). Concordance between two radiologists was assessed by intraclass correlation coefficients (ICCs) and Bland-Altman analysis.
A total of 61.1% of the sample (n=22) displayed a MRI-PDFF ≥ 5.6%; QUS cut-off values were TAI=0.625 (AUROC 0.90, confidence interval [CI] 0.77-1.00), TSI=91.95 (AUROC 0.99, CI 0.98-1.00) and EzHRI=1.215 (AUROC 0.98, CI 0.94-1.00). Inter-rater reliability was good-to-excellent for EzHRI (ICC 0.91, 95% C.I. 0.82-0.95) and TAI (ICC 0.94, 95% C.I. 0.88-0.97) and moderate to good for TSI (ICC 0.73; 95% C.I. 0.53-0.85).
Our results suggest that QUS can be used to reliably assess the presence and degree of pediatric hepatic steatosis.
肝活检仍是诊断小儿慢性肝病主要原因——肝脂肪变性的金标准；然而，其成本需要更具侵入性的方法。
本研究使用磁共振成像质子密度脂肪分数（MRI-PDFF）作为参考标准，检查定量超声（QUS）在小儿人群中评估肝脂肪含量的诊断准确性和可靠性。
我们纳入了 36 名患者。MRI-PDFF 涉及 3 维 T2*-加权带有 Dixon 脉冲多回波序列，使用水和脂肪的迭代分解与回声不对称和最小二乘法估计（IDEAL IQ）。QUS 成像依赖于超声系统“RS85A”（三星麦迪逊，首尔，韩国）和以下软件：自动推荐感兴趣区的肝肾功能指数（EzHRI）、组织衰减成像（TAI）和组织散射分布成像（TSI）。对于每个 QUS 指数，使用接收者操作特征（ROC）曲线分析与 MRI-PDFF 相对比，以确定相关的截断值和 ROC 曲线下面积（AUROC）。两名放射科医生的一致性通过组内相关系数（ICC）和 Bland-Altman 分析进行评估。
共有 61.1%（n=22）的样本的 MRI-PDFF≥5.6%；QUS 的截断值为 TAI=0.625（AUROC 0.90，置信区间 [CI] 0.77-1.00），TSI=91.95（AUROC 0.99，CI 0.98-1.00）和 EzHRI=1.215（AUROC 0.98，CI 0.94-1.00）。EzHRI（ICC 0.91，95%CI 0.82-0.95）和 TAI（ICC 0.94，95%CI 0.88-0.97）的观察者间可信度良好至极好，而 TSI（ICC 0.73；95%CI 0.53-0.85）的可信度为中度至良好。
我们的结果表明，QUS 可用于可靠地评估小儿肝脂肪变性的存在和程度。
