MRI在直肠癌术前诊断及分期中的应用

APPLICATION OF MRI IN PREOPERATIVE DIAGNOSIS AND STAGING IN RECTAL CANCER

目的评价MRI在直肠癌的术前诊断及临床分期中的应用价值。方法对48例直肠癌病人应用MRI进行TN分期,并与病理结果对照。结果 MRI对直肠癌的诊断率为100%（48/48）。MRI正确T分期39例,错误T分期9例,其中6例T1~T2期报告为T3期,3例T3期报告为T1~T2期。T分期的诊断的总准确率为81.3%（39/48）,其中T1~T2期诊断的准确率为86.3%（19/22）,T3、T4期诊断的准确率分别为66.7%（12/18）、100%（8/8）。经统计分析证实,MRI术前分期与病理分期结果的一致性较好（Kappa=0.696,P〈0.01）;MRI对直肠癌淋巴结正确分期36例,错误分期12例,其中高估6例,低估6例,准确率为75.0%（36/48）,灵敏度为68.4%（13/19）,特异度为79.3%（23/29）,MRI能对直肠癌系膜淋巴结分期做出较准确预测（Kappa=0.573,P〈0.05）。结论 MRI可较准确地评估直肠肿瘤浸润深度和淋巴结转移情况,并作出较准确的直肠癌术前TN分期。

Objective To assess the value of magnetic resonance imaging（MRI） in preoperative diagnosis and clinical staging of rectal cancer. Methods A TN staging was undertaken by MRI in 48 patients with rectal cancer,the result was compared with pathology. Results The final diagnosis for rectal cancer by MRI was 100%.For T staging,39 cases were correct,and nine were wrong： in which,six cases with T1-T2 were reported as T3;three with T3 reported as T1-T2.The totally accurate rate of T staging was 81.3%（39/48）,in which,the accuracy in T1-T2 staging was 86.3%（19/22）,in T3 was 66.7%（12/18） and T4 was 100%（8/8）.A statistic analysis indicated that preoperative MRI staging was better consistent with pathologic staging（Kappa=0.696,P0.01）.For MRI lymph node staging,the accurate was 36 cases,error in 12;in which,overstaged and understaged was six,respectively.The accuracy of node staging was 75.0%（36/48）,sensitivity was 68.4%（13/19）,and specificity was 79.3%（23/29）.MRI could make a relatively correct prediction for lymph node staging in cancer of the rectum（Kappa=0.573,P0.05）. Conclusion Preoperative MRI staging can relatively make an exact evaluation of the depth of tumor infiltration and lymph node metastasis and TN staging in rectal cancer.