目的探讨直肠腔内水囊在直肠 癌MRI术前分期中的应用价值。方法 36例 经肠镜病理证实直肠癌患者，术前MRI检 查前置入直肠腔内水囊，比较术前MRI临 床分期(肿瘤T分期、淋巴结转移N分期及 环周切缘受累)和术后病理结果，判断直 肠腔内水囊置入后MRI检查在直肠癌术前 分期中应用价值。结果 直肠腔内水囊置 入后MRI检查对直肠癌T分期及环周切缘受 累判断与病理学分期诊断一致性好(Kappa 值分别为0.751,0.769；P<0.01)，对肿瘤 T分期的总准确率为95%，环周切缘受累判 断准确率为91.7%，而淋巴结转移N分期与 病理学分期一致性具有一般统计学意义 (Kappa值=0.613；P<0.01)，淋巴结转移N 分期总准确率为80.6%。结论 直肠腔内水 囊置入后MRI检查对肿瘤T分期的诊断具有 较大价值，并能准确预测环周切缘受累情 况，而对淋巴结转移N分期只能作一般性 预测。

Objective To investigate the value of the magnetic resonance imaging (MRI) with intrarectal water-bag in the preoperative staging of rectal cancer. Methods 36 rectal cancer patients proven by colonoscopy and pathology were inserted intrarectal waterbags into before MRI examination, by the comparison of preoperative MRI clinical stage (tumor T staging, lymph node metastasis N stage and circumferential resection margin involvement) and postoperative pathological results, the application value of MRI examination with intrarectal water-bag in resection of rectal cancer staging can be decided. Results There was an accurate correlation between pathologic and MRI examination with intrarectal water-bag in rectal cancer T stage and circumferential resection margin involvement (kappa value was 0.751, 0.769; P<0.01). The total accuracy rate of tumor T stage was 95%, the circumferential resection margin involvement in assessing the accuracy rate was 91.7%. The correlation between pathologic and MRI in node staging was generic (kappa=0.613; P<0.01), and the lymph node metastasis N staging accuracy rate was 80.6%. Conclusion MRI examination with intrarectal water-bag in tumor T staging diagnosis had great value, and it can accurately predict the circumferential resection margin involvement, and the lymph node metastasis and N staging can only make a general prediction.