中文摘要：

目的评价扩散加权成像（DWI）和常规序列结合与常规序列对比，用于直肠癌诊断和分期方面的能力及优势。方法共46例经病理证实直肠癌患者，实验组：23例行DWI和常规序列结合扫描；对照组：23例行常规序列扫描。术前分别进行诊断与分期，与术后病理学结果进行统计学分析。实验组选取扩散b值800。对病灶信号强度观察及ADC值测量统计分析。结果实验组对直肠癌诊断和分期准确率为91％，对照组为61％，两组差别有统计学意义。实验组直肠癌病灶DWI图像的信号强度明显增高，ADC值减低，均值为（1．38±0．12）×10^-3mm^2／s。结论与常规序列相比，DWI和常规序列结合在直肠癌诊断和分期方面具有明显优势。

英文摘要：

Objective To evalute the capabilities and advantages of diffusion- with conventional sequence in the diagnosis and staging of rectal cancer. Methods weighted Imaging （DWI） in combination 46 patients with rectae cancer confirmed through pathology were divided into experimental group and control group with 23 dubjeets in each group. The patients in experimental group were subjected to DWI combined with conventional sequence scan. While, patients in control group un- derwent general conventional sequence scan. Preoperative diagnosis and N-staging were performed separately and compared with postoperative pathological results. In experimental group, the proliferation of h value 800 was selected to obseve the signal intensity in lesions and the ADC value was measured for statistic analysis. Results Accurate rate of diagnosis and staging of rectal cancor in experimental group was 91~, but, 61% in control group. There was a statistically significant difference between the two groups. The signal strength of DWI in the experimental group was significantly increased. Whereas, the ADC value （1.38±0.12）×10^-3mm^2/s was significantly reduced. Conclusion Compared with the conventional sequence, the combination of DW1 with conventional sequence had obvious advantages in the diagnosis and staging of rectal cancor.