Background US shear-wave elastography (SWE) and vibration-controlled transient elastography (VCTE) enable assessment of liver stiffness, an indicator of fibrosis severity. However, limited reproducibility data restrict their use in clinical trials. Purpose To estimate SWE and VCTE measurement variability in nonalcoholic fatty liver disease (NAFLD) within and across systems to support clinical trial diagnostic enrichment and clinical interpretation of longitudinal liver stiffness. Materials and Methods This prospective, observational, cross-sectional study (March 2021 to November 2021) enrolled adults with NAFLD, stratified according to the Fibrosis-4 (FIB-4) index (≤1.3, >1.3 and <2.67, ≥2.67), at two sites to assess SWE with five US systems and VCTE with one system. Each participant underwent 12 elastography examinations over two separate days within 1 week, with each day's examinations conducted by a different operator. VCTE and SWE measurements were reported in units of meters per second. The primary end point was the different-day, different-operator reproducibility coefficient (RDCDDDO) pooled across systems for SWE and individually for VCTE. Secondary end points included system-specific RDCDDDO, same-day, same-operator repeatability coefficient (RCSDSO), and between-system same-day, same-operator reproducibility coefficient. The planned sample provided 80% power to detect a pooled RDCDDDO of less than 35%, the prespecified performance threshold. Results A total of 40 participants (mean age, 60 years ± 10 [SD]; 24 women) with low (n = 17), intermediate (n = 15), and high (n = 8) FIB-4 scores were enrolled. RDCDDDO was 30.7% (95% upper bound, 34.4%) for SWE and 35.6% (95% upper bound, 43.9%) for VCTE. SWE system-specific RDCDDDO varied from 24.2% to 34.3%. The RCSDSO was 21.0% for SWE (range, 13.9%-35.0%) and 19.6% for VCTE. The SWE between-system same-day, same-operator reproducibility coefficient was 52.7%. Conclusion SWE met the prespecified threshold, RDCDDDO less than 35%, with VCTE having a higher RDCDDDO. SWE variability was higher between different systems. These estimates advance liver US-based noninvasive test qualification by (a) defining expected variability, (b) establishing that serial examination variability is lower when performed with the same system, and (c) informing clinical trial design. ClinicalTrials.gov Identifier NCT04828551 © RSNA, 2024 Supplemental material is available for this article.

中文翻译：

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美国剪切波和瞬时弹性成像在非酒精性脂肪性肝病中的再现性和可重复性。


背景 美国剪切波弹性成像 (SWE) 和振动控制瞬时弹性成像 (VCTE) 能够评估肝脏硬度，这是纤维化严重程度的指标。然而，有限的再现性数据限制了它们在临床试验中的使用。目的 评估系统内和系统间非酒精性脂肪性肝病 (NAFLD) 的 SWE 和 VCTE 测量变异性，以支持临床试验诊断丰富和纵向肝脏硬度的临床解释。材料和方法 这项前瞻性、观察性、横断面研究（2021 年 3 月至 2021 年 11 月）纳入了 NAFLD 成人，根据纤维化 4 (FIB-4) 指数（≤1.3、>1.3 和 <2.67）进行分层，≥2.67），在两个地点评估具有五个美国系统的 SWE 和具有一个系统的 VCTE。每个参与者在 1 周内的两天内接受 12 次弹性成像检查，每天的检查由不同的操作员进行。 VCTE 和 SWE 测量值以米每秒为单位报告。主要终点是 SWE 跨系统汇总的不同日期、不同操作员的再现性系数 (RDCDDDO) 和 VCTE 单独的再现性系数 (RCDDDDO)。次要终点包括系统特定的 RDCDDDO、同一天、同一操作员的重复性系数 (RCSDSO) 以及系统间同一天、同一操作员的再现性系数。计划的样本提供了 80% 的功效来检测低于 35%（预先指定的性能阈值）的汇总 RDCDDDO。结果 共有 40 名 FIB-4 分数低（n = 17）、中（n = 15）和高（n = 8）的参与者（平均年龄，60 岁±10 [SD]；24 名女性）入组。 SWE 的 RDCDDDO 为 30.7%（95% 上限，34.4%），VCTE 的 RDCDDDO 为 35.6%（95% 上限，43.9%）。 SWE 系统特定的 RDCDDDO 从 24.2% 到 34.3% 不等。 SWE 的 RCSDSO 为 21.0%（范围为 13.9%-35.0%），VCTE 的 RCSDSO 为 19.6%。 SWE 系统间同一天、同一操作员的重现性系数为 52.7%。结论 SWE 满足预先设定的阈值，RDCDDDO 小于 35%，VCTE 的 RDCDDDO 更高。不同系统之间的 SWE 变异性较高。这些估计通过（a）定义预期变异性，（b）确定使用相同系统进行时连续检查变异性较低，以及（c）为临床试验设计提供信息，从而推进基于美国肝脏的无创测试资格。 ClinicalTrials.gov 标识符 NCT04828551 © RSNA, 2024 本文提供补充材料。