程美清?吴少虹?潘嘉敏?全显跃?陈立达?梁文

【摘要】目的 探討实时二维剪切波弹性成像（SWE）联合直肠腔内超声（ERUS）在直肠癌术前浸润深度（T分期）诊断的准确性，并与ERUS和增强磁共振成像（MRI）进行比较。方法 收集85例经病理确诊为直肠癌患者的临床资料，患者均于术前进行ERUS、SWE和增强MRI检查，以术后病理T分期为金标准，分析ERUS、SWE联合ERUS和MRI这3种检查方法对直肠癌术前T分期诊断的准确性。结果 采用SWE获得的杨氏模量平均值在直肠癌各T分期中差异有统计学意义（P < 0.05）。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63.5、114.9和190.7 kPa，其曲线下面积为0.864～0.994。SWE联合ERUS对直肠癌患者术前T分期的诊断与病理的符合率高于ERUS（P < 0.05），稍高于MRI检查，但比较差异无统计学意义（P > 0.05）。在亚组分析中，对于T1～T2期直肠癌，SWE联合ERUS与病理分期的符合率高于ERUS和MRI（P均 < 0.05），对于T3～T4期直肠癌，MRI与病理的符合率高于ERUS（P < 0.05），稍高于SWE联合ERUS，但比较差异无统计学意义（P > 0.05）。结论SWE能够直观反映肿瘤硬度， SWE联合ERUS在直肠癌术前T分期诊断准确率高于ERUS，且稍高于增强MRI检查，尤其在T1～T2期直肠癌分期中优于MRI和ERUS。

【关键词】直肠癌;直肠腔内超声;剪切波弹性成像;核磁共振

Application of shear wave elastography in T staging of rectal cancer Cheng Meiqing， Wu Shaohong， Pan Jiamin， Quan Xianyue， Chen Lida， Liang Wen. Department of Radiology， Zhujiang Hospital， Southern Medical University， Guangzhou 510280， China

Correspongding author， Chen Lida， E-mail： chenlda@mail.sysu.edu.cn; Liang Wen， E-mail： liangwendoc@163.com

【Abstract】Objective To evaluate the diagnostic accuracy of two-dimensional shear wave elastography （SWE） combined with endorectal ultrasonography （ERUS） for preoperative invasion depth of rectal cancer （T staging）， and compare it with those of ERUS and enhanced magnetic resonance imaging （MRI）. Methods Clinical data of 85 patients pathologically diagnosed with rectal cancer were collected. All patients received ERUS， SWE and MRI before surgery. Postoperative pathological T staging was regarded as the gold standard. The diagnostic accuracy of ERUS， SWE combined with ERUS and MRI in preoperative T staging was statistically compared. Results The average of Youngs modulus measured by SWE in rectal cancer at different T stages had statistical significance （all P < 0.05）. Receiver operating characteristic curve （ROC） revealed that the optimal cut-off values for T1/T2， T2/T3， and T3/T4 were 63.5 kPa， 114.9 kPa and 190.7 kPa， respectively. The area under the curve （AUC） was 0.864-0.994. The concordance rate of T staging for SWE combined with ERUS was significantly higher than that of ERUS （P < 0.05） and slightly higher than that of enhanced MRI （P > 0.05）. In the subgroup analysis of T1 and T2 stages， the concordance rate of T staging for SWE combined with ERUS was significantly higher than those of ERUS and enhanced MRI （both P < 0.05）. However， in the subgroup analysis of T3 and T4 stages， the concordance rate of T staging for enhanced MRI was significantly higher than ERUS （P < 0.05）， and slightly higher than that of SWE （P > 0.05）. Conclusions SWE can directly detect the tumor stiffness. SWE combined with ERUS yields high accuracy in the diagnosis of preoperative T staging of rectal cancer compared with ERUS and enhanced MRI， especially in the diagnosis of preoperative T1 and T2 staging of rectal cancer.

【Key words】Rectal cancer; Endorectal ultrasonography; Shear wave elastography; Magnetic resonance imaging

结直肠癌是全球第3常见的恶性肿瘤，在恶性肿瘤病死率中亦高居第3位[1]。在结直肠癌中，直肠癌约占1/3[2]。近年来，直肠癌发病率逐年上升，发病年龄呈年轻化趋势，且其出现典型症状时常为中晚期，预后较差，严重威胁人类健康[3]。直肠癌的准确分期对临床治疗方案、手术方式的选择以及预后评估尤为重要。目前临床上使用TNM 分期指导直肠癌患者的治疗方式与预后评估[4]。其中，评估肿瘤浸润肠壁的深度（T分期）对于直肠癌患者治疗方式的选择最为重要。对于直肠癌T分期，MRI和直肠腔内超声（ERUS）是目前公认准确率较高的影像学方法[5-6]。但MRI会受肠道蠕动、肿瘤周边炎性改变及纤维增生影响[7]。……