目的 分析经直肠常规超声 (ERUS)与实时组织弹性成像(RTE)在直肠 癌鉴别诊断及术前分期中的价值。方法 选取2015年4月至2017年3月我院诊治的疑 似直肠癌患者50例为研究对象，病理证实 直肠癌恶性30例，直肠良性肿瘤20例，另 选取30例健康志愿者为对照组。均行ERUS 检查，应用RTE技术测量病灶与周围脂肪 组织应变率(SR)比值，观察不同病变影像 特点，对比直肠癌良恶性及不同分期患者 SR比值，分析SR鉴别直肠癌最佳界值的诊 断效能及ROC曲线下面积，对比ERUS及RTE 对术前分期的准确率。结果 ERUS下直肠 癌主要表现为实性肿块或肠壁明显增厚， 内部回声减低，边界不清，形状无规则 性，RTE检查则见直肠良性肿瘤者红绿相 间或蓝绿相间，恶性肿瘤者蓝色成分增 多，对照组则为红绿相间或以绿色为主； 直肠恶性肿瘤组SR比值大于直肠良性肿 瘤组、对照组(P＜0.05)，但术前直肠癌 不同分期患者SR比值无统计学意义(P＞ 0.05)；以SR=2.34作为鉴别直肠肿瘤最 佳界值，其诊断灵敏度、特异度、准确 度分别为90.00%、80.00%、86.00%，ROC 曲线下面积0.943；ERUS联合RTE对直肠 癌术前T2、T3、T4分期的准确率90.00%、 85.71%、87.50%较单纯ERUS或RTE高(P ＜0.05)。结论 ERUS及RTE对直肠癌具有 较高鉴别诊断价值，两者联合应用可提高 术前分期准确率，尤其是T2-T4期，值得 在临床推广应用。

Objective Toanalyze the value of transrectal conventional ultrasound (ERUS) and real-time tissue elastography (RTE) in the differential diagnosis and preoperative staging of rectal cancer. Methods 50 cases of patients with suspected rectal cancer treated in our hospital from April 2015 to March 2017 were selected for this study. 30 patients withmalignant rectal cancer and 20 patients with benign rectal tumor were diagnosed by pathological examination, and 30 healthy volunteers were selected as the control group. The three groups were all examined by ERUS and the ratio of the lesion and surrounding adipose tissue strain rate were measured by RTE technique. The characteristics of different lesions images were observed and the SR ratio in benign and malignant rectal cancer or at different stages were compared. What's more the diagnostic efficiency of optimal value of rectal cancer identified by SR and areas under ROC curve were analyzed and accuracy rates of preoperative staging with ERUS and RTE were compared. Results Solid mass or thickened intestinal wall, the decreased internal echo, the unclear border and irregular shape were mainly manifested in rectal cancer in ERUS. Under the RTE examination red and green or blue and green was seen in patients with benign rectal tumors and the increased composition of blue color was shown in patients with malignant rectal tumors and red and green or green-based in the control group. The SR ratio in the rectal cancer group was higher than that in benign rectal tumor group and the control group (P < 0.05), but there was no significant difference in SR ratio between different stages of rectal cancer (P>0.05). SR=2.34 was regarded as the optimal value for the identification of rectal tumor, whose sensitivity, specificity and accuracy were 90%, 80%, 86% respectively and area under the ROC curve was 0.943. The accuracy rates on preoperative T2, T3, T4 staging in the combination of ERUS and RTE were 90%, 85.71% and 87.50% which were higher than those in ERUS or RTE (P<0.05). Conclusion ERUS and RTE have a high differential diagnosis value for rectal cancer. The combination of ERUS and RTE can improve the accuracy rates of preoperative staging, especially in T2-T4. Therefore ERUS and RTE is worthy of clinical application.