磁共振与腔内超声对直肠癌术前TN分期准确性的比较

Comparison of magnetic resonance imaging and endorectal ultrasound for preoperative TN staging of rectal cancer

目的 比较磁共振成像（MRI）和直肠腔内超声（ERUS）对直肠癌术前分期的诊断价值.方法 前瞻性分析2012年7月至2013年2月于北京协和医院诊治并于术前均行MRI和ERUS术前分期检查的29例直肠癌患者,男性13例,女性16例,平均年龄（64.0±11.7）岁,与术后病理结果对比,比较MRI和ERUS对直肠肿瘤浸润深度（T分期）、区域淋巴结转移（N分期）判断的准确性.结果 MRI对29例直肠癌T分期和N分期与病理比较分析.ERUS因3例肠腔狭窄或探头无法探测而最终对26例行T分期与病理比较;判断淋巴结转移中4例ERUS无法确定分期而最终对25例N分期与病理比较分析.MRI判断T分期总的准确度为75.9%（22/29）,ERUS判断T分期总的准确度为65.4%（17/26）.MRI分别对T1、T2、T4期病变诊断的准确度较ERUS高（93%与88.5%,75.9%与69.2%,100%与96.2%）,而T3期病变ERUS较MRI准确度高（88.5%与82.8%）.MRI评价直肠癌术前N分期的准确度、灵敏度、特异度分别是72.4%（21/29）、50%（5/10）、84.2%（16/19）;ERUS评价直肠癌术前N分期的准确度、灵敏度、特异度分别是64%（16/25）、50%（3/6）、68.4%（13/19）.结论 MRI与ERUS判断T分期的准确性差异无统计学意义,但MRI对早期病变（T1、T2期）的准确度较高,而ERUS判断T3期病变的准确率高于MRI.二者判断N分期的准确度呈中等水平,但MRI判断N分期的准确度及特异度较ERUS高.

Objective To compare the clinical values of magnetic resonance imaging （MRI） and endorectal ultrasound （ERUS） in preoperative TN staging of rectal cancer. Methods From July 1, 2012 to Feb. 28, 21）13, totally 29 rectal cancer patients （13 men and 16 women with a mean age of 64. 0 ± 11.7 years, range 37-86 years） were examined using both MRI and ERUS before the operation With pathological results, the diagnostic accuracy of MRI and ERUS for rectal tumor invasion depth （T staging） and regional lymph node metastasis （N staging） was compared. Results Since ERUS was failed in 3 cases due to the narrowed enteric cavity, this study finally compared 26 cases for T staging analysis. Also, since it was not able to determine the staging for 4 cases when evaluating lymph node metastasis using ERUS, 25 cases were finally enrolled for N staging analysis. Overall accuracy of MRI for the evaluation of T staging was 75.9% （22/29）, and that of ERUS was 65.4% （17/26）. The diagnostic accuracy of MRI for stage T1, T2 and T4 was higher than ERUS （93% vs. 88. 5%, 75.9% vs. 69. 2%, 100% vs. 96. 2%）, but ERUS was more accurate than MRI in T3 lesions （88. 5% vs. 82. 8%）. Accuracy, sensitivity and specificity of MRI in N staging was 72. 4% （21/29）, 50% （5/10） and 84. 2% （16/19）, respectively, and those of ERUS in N staging was 64% （16/25）, 50%（3/6） and 68. 4% （13/19）, respectively. Conclusion There was no statistically significant difference in accuracy of MRI and ERUS for the evaluation of T staging in rectal cancer, but MRI had better diagnostic accuracy in early lesions （T1 and T2 stage）, while ERUS showed better accuracy in advanced lesions （T3 stage）. Both had moderate accuracy for the evaluation of N staging, but the accuracy and specificity of MRI for N staging were higher than ERUS.