Department of Radiology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou 510120, Guangdong Province, China.
MR Scientific Marketing, Siemens Healthineers, Guangzhou 510120, Guangdong Province, China.
World J Gastroenterol. 2021 Mar 28;27(12):1182-1193. doi: 10.3748/wjg.v27.i12.1182.
R2* estimation reflects the paramagnetism of the tumor tissue, which may be used to differentiate between benign and malignant liver lesions when contrast agents are contraindicated.
To investigate whether R2* derived from multi-echo Dixon imaging can aid differentiating benign from malignant focal liver lesions (FLLs) and the impact of 2D region of interest (2D-ROI) and volume of interest (VOI) on the outcomes.
We retrospectively enrolled 73 patients with 108 benign or malignant FLLs. All patients underwent conventional abdominal magnetic resonance imaging and multi-echo Dixon imaging. Two radiologists independently measured the mean R2* values of lesions using 2D-ROI and VOI approaches. The Bland-Altman plot was used to determine the interobserver agreement between R2* measurements. Intraclass correlation coefficient (ICC) was used to determine the reliability between the two readers. Mean R2* values were compared between benign and malignant FFLs using the nonparametric Mann-Whitney test. Receiver operating characteristic curve analysis was used to determine the diagnostic performance of R2* in differentiation between benign and malignant FFLs. We compared the diagnostic performance of R2* measured by 2D-ROI and VOI approaches.
This study included 30 benign and 78 malignant FLLs. The interobserver reproducibility of R2* measurements was excellent for the 2D-ROI (ICC = 0.994) and VOI (ICC = 0.998) methods. Bland-Altman analysis also demonstrated excellent agreement. Mean R2* was significantly higher for malignant than benign FFLs as measured by 2D-ROI ( < 0.001) and VOI ( < 0.001). The area under the curve (AUC) of R2* measured by 2D-ROI was 0.884 at a cut-off of 25.2/s, with a sensitivity of 84.6% and specificity of 80.0% for differentiating benign from malignant FFLs. R2* measured by VOI yielded an AUC of 0.875 at a cut-off of 26.7/s in distinguishing benign from malignant FFLs, with a sensitivity of 85.9% and specificity of 76.7%. The AUCs of R2* were not significantly different between the 2D-ROI and VOI methods.
R2* derived from multi-echo Dixon imaging whether by 2D-ROI or VOI can aid in differentiation between benign and malignant FLLs.
R2* 估测反映了肿瘤组织的顺磁性，当对比剂被禁用时，它可能用于区分良性和恶性肝病变。
研究多回波 Dixon 成像得出的 R2* 是否可辅助区分良性和恶性局灶性肝病变（FLL），以及 2D 感兴趣区（2D-ROI）和体积感兴趣区（VOI）对结果的影响。
我们回顾性纳入了 73 例 108 个良性或恶性 FLL 患者。所有患者均接受了常规腹部磁共振成像和多回波 Dixon 成像检查。两位放射科医生分别使用 2D-ROI 和 VOI 方法测量病变的平均 R2* 值。采用 Bland-Altman 图确定 R2* 测量的观察者间一致性。采用组内相关系数（ICC）评估两位观察者之间的可靠性。采用非参数 Mann-Whitney 检验比较良性和恶性 FFL 之间的平均 R2* 值。采用受试者工作特征曲线分析评估 R2* 在良性和恶性 FFL 之间的鉴别诊断性能。我们比较了 2D-ROI 和 VOI 方法测量的 R2* 的诊断性能。
本研究纳入了 30 个良性和 78 个恶性 FLL。2D-ROI（ICC=0.994）和 VOI（ICC=0.998）方法的 R2* 测量具有极好的观察者间可重复性。Bland-Altman 分析也显示出极好的一致性。与良性 FFL 相比，恶性 FFL 的 R2* 平均值通过 2D-ROI（<0.001）和 VOI（<0.001）测量均显著更高。2D-ROI 测量的 R2* 截断值为 25.2/s 时，曲线下面积（AUC）为 0.884，其用于区分良性和恶性 FFL 的灵敏度为 84.6%，特异性为 80.0%。VOI 测量的 R2* 截断值为 26.7/s 时，AUC 为 0.875，用于区分良性和恶性 FFL 的灵敏度为 85.9%，特异性为 76.7%。2D-ROI 和 VOI 方法测量的 R2* 的 AUC 无显著差异。
多回波 Dixon 成像得出的 R2*（无论是通过 2D-ROI 还是 VOI 测量）都有助于区分良性和恶性 FLL。
