目的 探讨应用直肠腔内置入水 囊后MRI检查在直肠癌术前分期的诊断价 值。方法 80例经病理证实的直肠癌患者 均行术前MRI检查, 经随机分配其中40例 经直肠腔内置入水囊后MRI检查，40例行 常规直肠MRI检查，分别对80例患者的检 查结果进行肿瘤(T)分期及淋巴结转移(N) 分期的术前诊断评估，将术前MRI检查结 果与术后病理结果进行对照比较，并将行 水囊置入后MRI检查与常规MRI检查的准确 率进行对比。结果 直肠腔内置入水囊后 MRI检查对直肠癌T分期与病理学分期诊断 具有较好的一致性(P<0.01)，对直肠周 围淋巴结转移N分期与病理学分期诊断一 致性一般(P<0.01)，该检查方法对肿瘤T 分期的总准确率为90%，N分期总准确率为 77.5%；常规直肠MRI检查对直肠癌临床T 分期及淋巴结转移N分期与病理学分期一 致性具有一般统计学意义(P<0.01)，对肿 瘤T分期的总准确率为72.5%，对淋巴结转 移N分期总准确率为80%。直肠内置入水囊 后MRI检查与常规直肠MRI检查对肿瘤T分 期诊断的准确性具有显著差异(P<0.05), 对淋巴结转移的N分期诊断无明显差异(P ＞0.05)。结论 直肠腔内置入水囊后MRI 检查对肿瘤术前T分期的诊断具有较大价 值，对淋巴结转移的分期诊断与常规MRI 检查大致相符。

Objective To evaluate the diagnostic value of MRI with water-bag in rectum for the preoperative staging of rectal cancer. Methods Preoperative MRI was performed in 80 patients with pathology confirmed rectal cancer. 40 of them were randomly assigned for MRI with water-bag in rectum, and the last 40 was assigned for conventional MRI. The diagnostic value of tumor (T) and lymph node (N) staging were analyzed, and the results were compared with postoperative pathology results. The diagnostic accuracy of these two methods was also compared. Results The results of T staging of MRI with water-bag in rectum were in good agreement with the histopathology results (P<0.01), and the results of N staging were in common agreement (P<0.01), total T and N staging accuracy were 90% and 77.5%, the results of T and N staging of conventional MRI were in common agreement with the histopathology results (P<0.01), total T and N staging accuracy were 72.5% and 80%. There was statistically significant difference (P<0.05) between T-staging results of MRI with water-bag in rectum and conventional MRI, and no significant difference (P＞0.05) between N-staging results. Conclusion Preoperative MRI with water-bag in rectum have certain value for T-staging of rectal cancer, and shows no significant difference in N-staging with conventional MRI.