目的 研究腔内剪切波弹性成像（shear wave elastrography,SWE）所得杨氏模量值与直肠癌淋巴结是否转移的相关性；探讨SWE对直肠癌T分期的诊断价值。方法 回顾分析53例直肠癌患者的临床资料，所有患者术前均接受经直肠腔内超声(endorectal ultrasonography，ERUS)及SWE检查并测量病灶平均杨氏模量（Emean）值，以术后病理为金标准，根据盆腹腔是否发生淋巴结转移，分为淋巴结转移组(lymph node metastasis,LNM)和非淋巴结转移组(non-lymph node metastasis,NLNM)，评估SWE与直肠癌LNM的相关性及诊断T分期的准确性。结果 直肠癌LNM与病灶的Emean值具有中度正相关关系（r =0.533，P ＜0.001），LNM与NLNM之间的Emean值差异具有统计学意义（P ＜0.001）；ERUS联合SWE对直肠癌T分期的诊断准确率为86.8%，直肠癌不同T分期的Emean值差异具有统计学意义（P ＜0.001）。受试者工作特征（ROC）曲线显示 T1/T2、T2/T3、T3/T4 最佳分期截断值分别为19.8、47.1、141.6kPa，其曲线下面积为 0.718～1.000。结论ERUS联合SWE技术可以做为辅助诊断直肠癌T分期的有效方法，直肠癌Emean值与LNM的密切相关也证明了其在预测直肠癌预后方面的优异性能。
Objective To investigate the correlation between Young's modulus obtained by shear wave elastrography (SWE) and lymph node metastasis in rectal cancer. To explore the diagnostic value of SWE in T stage of rectal cancer. Methods The clinical data of 53 rectal cancer patients were retrospectively analyzed. All patients were examined with the endorectal ultrasonography (ERUS) and SWE before operation, and the average lesion Emean value was measured with the postoperative pathology as the gold standard. According to whether lymph node metastasis occurred in pelvis and peritoneal cavity, there were two groups: lymph node metastasis group (LNM) and non-lymph node metastasis group (NLNM). The correlation between SWE and LNM of rectal cancer and the accuracy of T staging were evaluated. Results There was a moderate positive correlation between LNM and Emean values (r =0.533, P < 0.001), and the difference of Emean values between LNM and NLNM was statistically significant (P < 0.001). The diagnostic accuracy of ERUS combined with SWE for T stage of rectal cancer was 86.8%, and the difference of Emean values for different T stages of rectal cancer was statistically significant (P < 0.001). Receiver operating characteristic (ROC) curve showed that the optimal staging cutoff values of T1/T2, T2/T3 and T3/T4 were 19.8, 47.1 and 141.6kPa, respectively, and the area under the curve was 0.718 ~ 1.000. Conclusion ERUS combined with SWE technique can be used as an effective method to assist the diagnosis of T stage of rectal cancer. The close correlation between Emean value and LNM of rectal cancer also proves its excellent performance in predicting the prognosis of rectal cancer.