目的 分析讨论直肠癌术前 应用螺旋CT(SCT, spiral computed tomography)进行肿瘤(T)与淋巴结(N)分 期的临床效果，同时评估SCT三维成像技 术(MRP, multiplannar reconstruction) 在测量中、低位直肠癌距肛门缘距离中的 应用价值。方法 对46例经电子结肠镜与 活检证实为直肠癌患者术前行SCT检查， 其中33例为中、低位直肠癌，将其结果与 术后病理结果进行对照，评析SCT用于术 前分期的准确性；同时利于SCT三维成像 技术、直肠指诊、结肠镜等三种方法对 肿瘤下缘到肛门缘的距离进行测定，并 与术后测量的实际距离进行对比，分析 SCT的测量准确度；再对15例距离≤6cm 的患者进行测定，比较SCT与直肠指诊的 准确性。结果 SCT诊断T分期的准确度为 73.9%，其中对进展期直肠癌的T分期准确 率高达92.8%；对N分期的诊断准确度为 67.4%，对淋巴转移的敏感度为91.3%，特 异度为69.6%。经Kappa检验分别为0.479 和0.569。另SCT、直肠指诊与肠镜检查准 确度分别为84.8%、48.5%和36.4%，差异 有显著意义(P<0.005)。而对15 例低位直 肠癌(实际距离≤6cm)，SCT 和肛门指诊 准确度无显著差异(P=0.245)。结论 SCT 对进展期直肠癌术前分期可靠性较高，但 对T1、T2期的诊断准确性并不高，而在中 低位直肠癌患者中，三维成像技术在测定 肿瘤下缘到肛门缘距离十分准确，可推广 应用。

Objective To analyze the clinical effect of CT (spiral, computed tomography) in the preoperative application and N staging in rectal cancer, and to evaluate the application value of SCT MRP (Multiplannar, reconstruction) in the measurement of the distance from the anus. Methods By colonoscopy and biopsy in 46 cases confirmed patients with rectal cancer underwent SCT examination, including 33 cases of rectal cancer, the status, the results were compared with the postoperative pathological findings, analysis of SCT for preoperative staging accuracy; and is beneficial to the SCT 3D imaging technology, digital rectal examination, colonoscopy and distance three methods of patients with lower margin to the anal margin were measured and compared with the actual distance is measured after operation, analysis of SCT measurement accuracy; and in 15 cases of patients with distance less than or equal to 6cm were determined to compare SCT with rectal examination accuracy. Results The accuracy of SCT T staging was 73.9%, and the accuracy rate of T staging of rectal cancer was 92.8%, the accuracy of N staging was 67.4%, the sensitivity was 91.3% and specificity was 69.6%. The results of Kappa test showed that the consistency of the medium was 0.479 and 0.569 respectively. The other SCT, digital rectal examination and colonoscopy methods of inspection accuracy was 84.8%, 48.5% and 36.4% respectively,and the difference was significant (P<0.005). In the 15 patients with low rectal cancer (the actual distance is less than or equal to 6cm),the accuracy of SCT and dre had no significant difference (P=0.245). Conclusion SCT has a high reliability of preoperative staging of rectal cancer, but the diagnosis accuracy of T2 and T1 is not high. In the middle and low rectal cancer patients, the three-dimensional imaging technology is very accurate,which can be promoted and applicated.