Department of Radiology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea.
Division of Biomedical Engineering, Hankuk University of Foreign Studies, Yongin, Korea.
Korean J Radiol. 2020 Apr;21(4):431-441. doi: 10.3348/kjr.2019.0479.
To compare the diagnostic performance and interobserver variability of strain ratio obtained from one or two regions of interest (ROI) on breast elastography.
From April to May 2016, 140 breast masses in 140 patients who underwent conventional ultrasonography (US) with strain elastography followed by US-guided biopsy were evaluated. Three experienced breast radiologists reviewed recorded US and elastography images, measured strain ratios, and categorized them according to the American College of Radiology breast imaging reporting and data system lexicon. Strain ratio was obtained using the 1-ROI method (one ROI drawn on the target mass), and the 2-ROI method (one ROI in the target mass and another in reference fat tissue). The diagnostic performance of the three radiologists among datasets and optimal cut-off values for strain ratios were evaluated. Interobserver variability of strain ratio for each ROI method was assessed using intraclass correlation coefficient values, Bland-Altman plots, and coefficients of variation.
Compared to US alone, US combined with the strain ratio measured using either ROI method significantly improved specificity, positive predictive value, accuracy, and area under the receiver operating characteristic curve (AUC) (all values < 0.05). Strain ratio obtained using the 1-ROI method showed higher interobserver agreement between the three radiologists without a significant difference in AUC for differentiating breast cancer when the optimal strain ratio cut-off value was used, compared with the 2-ROI method (AUC: 0.788 vs. 0.783, 0.693 vs. 0.715, and 0.691 vs. 0.686, respectively, all values > 0.05).
Strain ratios obtained using the 1-ROI method showed higher interobserver agreement without a significant difference in AUC, compared to those obtained using the 2-ROI method. Considering that the 1-ROI method can reduce performers' efforts, it could have an important role in improving the diagnostic performance of breast US by enabling consistent management of breast lesions.
比较在超声弹性成像中，从一个或两个感兴趣区（ROI）获得的应变比的诊断性能和观察者间变异性。
2016 年 4 月至 5 月，对 140 例经常规超声（US）检查伴应变弹性成像并随后行 US 引导下活检的乳腺肿块患者进行了评估。三位经验丰富的乳腺放射科医师对记录的 US 和弹性成像图像进行了回顾，测量了应变比，并根据美国放射学院乳腺影像学报告和数据系统词汇进行了分类。应变比采用 1-ROI 方法（在目标肿块上画一个 ROI）和 2-ROI 方法（在目标肿块和参考脂肪组织上各画一个 ROI）进行测量。评估了三位放射科医师在数据集之间的诊断性能和应变比的最佳临界值。使用组内相关系数值、Bland-Altman 图和变异系数评估了每种 ROI 方法的观察者间应变比变异性。
与单独使用 US 相比，US 联合使用任一 ROI 方法测量的应变比均显著提高了特异性、阳性预测值、准确性和受试者工作特征曲线（ROC）下面积（所有 P 值均<0.05）。与 2-ROI 方法相比，使用 1-ROI 方法测量的应变比在使用最佳应变比临界值时，三位放射科医师之间的观察者间一致性更高，而在区分乳腺癌时 AUC 无显著差异（AUC：0.788 比 0.783、0.693 比 0.715、0.691 比 0.686，均 P 值>0.05）。
与使用 2-ROI 方法相比，使用 1-ROI 方法测量的应变比具有更高的观察者间一致性，而 AUC 无显著差异。考虑到 1-ROI 方法可以减少操作者的工作量，它在提高乳腺 US 的诊断性能方面可能具有重要作用，因为它可以使乳腺病变的管理更加一致。
