From the Department of Clinical-Surgical, Diagnostic, and Pediatric Sciences, University of Pavia, Pavia, Italy (G.F.); Division of Internal Medicine and Hepatology, Azienda Ospedaliero Universitaria Careggi, Firenze, Italy (D.R.); Sherlock Liver Unit and UCL Institute for Liver and Digestive Health, Royal Free Hospital, London, England (D.R.); Department of Radiology, Northeast Ohio Medical University, Rootstown, Ohio (R.G.B.); and Southwoods Imaging, 7623 Market St, Youngstown, OH 44512 (R.G.B.).
Radiology. 2024 Oct;313(1):e240162. doi: 10.1148/radiol.240162.
Background The extent of liver steatosis can be assessed using US attenuation coefficient (AC) algorithms currently implemented in several US systems. However, little is known about intersystem and interoperator variability in measurements. Purpose To assess intersystem and interoperator agreement in US AC measurements for fat quantification in individuals with varying degrees of liver steatosis and to assess the correlation of each manufacturer's AC algorithm results with MRI proton density fat fraction (PDFF). Materials and Methods This prospective study was conducted at Southwoods Imaging, Youngstown, Ohio, September 30-October 1, 2023. Two operators independently obtained AC measurements using eight US systems equipped with an AC algorithm from different manufacturers. On the same day, MRI PDFF measurement was performed by a different operator. Correlation between US AC and MRI PDFF was assessed using a mixed-effects model. Agreement between systems and operators was evaluated using the intraclass correlation coefficient (ICC). Results Twenty-six individuals (mean age, 55.4 years ± 10.7 [SD]; 16 female participants) were evaluated. The correlation of US AC with MRI PDFF was high for five AC algorithms ( range, 0.70-0.86), moderate for two ( = 0.62 for both), and poor for one ( = 0.47). In pairwise comparisons, none of the pairs of systems achieved excellent agreement (overall ICC = 0.33 [95% CI: 0.15, 0.52]). One pair showed good agreement (ICC = 0.79 [95% CI: 0.66, 0.87]), eight pairs showed moderate agreement (ICC range, 0.50 [95% CI: 0.22, 0.69] to 0.73 [95% CI: 0.49, 0.85]), and 19 pairs showed poor agreement (ICC range, 0.11 [95% CI: -0.06, 0.37] to 0.48 [95% CI: 0.20, 0.67]). Interoperator agreement on AC value was excellent for the Samsung Medison algorithm (ICC = 0.90 [95% CI: 0.80, 0.96]), good for the Siemens Healthineers (ICC = 0.76 [95% CI: 0.54, 0.89]) and Canon Medical Systems (ICC = 0.76 [95% CI: 0.16, 0.92]) algorithms, and moderate for the remaining algorithms (ICC range, 0.50 [95% CI: 0.16, 0.73] to 0.74 [95% CI: 0.51, 0.88]). The mean AC value obtained by the two operators did not differ for any system except the system from Canon Medical Systems. Conclusion There was substantial variability in AC values obtained with different US systems, precluding interchangeability between systems for liver steatosis diagnosis and follow-up imaging. Interoperator agreement ranged from moderate to excellent. © RSNA, 2024 See also the editorial by Han in this issue.
背景 目前，几种超声系统中都实施了基于 US 衰减系数 (AC) 算法的肝脂肪变性程度评估。然而，对于不同系统和操作人员之间的测量值变异性，人们知之甚少。 目的 评估不同系统和操作人员在具有不同程度肝脂肪变性的个体中使用 US AC 测量值进行脂肪定量的一致性，并评估每个制造商的 AC 算法结果与 MRI 质子密度脂肪分数 (PDFF) 的相关性。 材料与方法 本前瞻性研究于 2023 年 9 月 30 日至 10 月 1 日在俄亥俄州扬斯敦的 Southwoods Imaging 进行。两名操作人员分别使用来自不同制造商的 8 种配备 AC 算法的 US 系统独立获得 AC 测量值。同日，由另一名操作人员进行 MRI PDFF 测量。使用混合效应模型评估 US AC 与 MRI PDFF 之间的相关性。使用组内相关系数 (ICC) 评估系统和操作人员之间的一致性。 结果 共评估了 26 名个体（平均年龄，55.4 岁±10.7[标准差]；16 名女性参与者）。五种 AC 算法的 US AC 与 MRI PDFF 相关性较高（范围，0.70-0.86），两种算法的相关性中等（均为 = 0.62），一种算法的相关性较差（ = 0.47）。在两两比较中，没有一对系统达到了极好的一致性（总体 ICC = 0.33[95%CI：0.15，0.52]）。一对系统显示出很好的一致性（ICC = 0.79[95%CI：0.66，0.87]），八对系统显示出中等程度的一致性（ICC 范围，0.50[95%CI：0.22，0.69]至 0.73[95%CI：0.49，0.85]），19 对系统显示出较差的一致性（ICC 范围，0.11[95%CI：-0.06，0.37]至 0.48[95%CI：0.20，0.67]）。三星麦迪逊算法的 AC 值的操作人员间一致性极好（ICC = 0.90[95%CI：0.80，0.96]），西门子健康解决方案公司（ICC = 0.76[95%CI：0.54，0.89]）和佳能医疗系统（ICC = 0.76[95%CI：0.16，0.92]）算法的操作人员间一致性良好，其余算法的操作人员间一致性中等（ICC 范围，0.50[95%CI：0.16，0.73]至 0.74[95%CI：0.51，0.88]）。除了佳能医疗系统的系统外，两名操作人员使用任何系统获得的 AC 值平均值均无差异。 结论 不同 US 系统获得的 AC 值存在很大差异，不允许系统之间用于肝脂肪变性的诊断和随访成像的互换性。操作人员间的一致性范围为中等至极好。 ©2024 RSNA，见本期 Han 社论。
