MRI常规序列结合DWI对盆腔内结直肠癌术前临床分期的价值

Study of DWI combined with conventional MRI sequence in pre-surgical staging of colorectal cancer

目的 ：探讨MRI常规序列结合DWI对盆腔内结直肠癌术前T-N分期的价值。方法 ：53例经病理证实结直肠癌患者,术前对其行MRI常规序列及DWI检查。并根据AJCC 2010版癌症分期手册制订影像学分期标准,进行术前T分期和局部N分期,与术后病理T分期（pathological T stages,p T）和局部的N分期（pathological N stages,p N）比较。结果：MRI对p T1~2期的诊断准确率88.7%,p T3期83.0%,p T4期94.3%,对T分期总诊断准确率83.0%,与病理分期一致性好（K=0.582,P〈0.01）。MRI对N分期诊断准确率81.1%,特异性89.2%,敏感性62.5%,阳性预测值71.4%,阴性预测值84.6%,与病理分期一致性好（K=0.536,P〈0.001）。结论：MRI常规序列结合DWI对盆腔内结直肠癌术前T-N分期具有重要价值。

Objective：To investigate the value of diffusion weighted imaging （DWI） combined with conventional MRI sequence in pre-surgical staging of colorectal cancer. Methods：53 patients confirmed colorectal cancer received MR examination before surgery. Tumor staging were performed according to the imaging standard of Cancer Staging Manual of AJCC （edition 2010）. Pathological T stages （pT） and pathological N stages （pN） were evaluated based on MRI results before surgery and compared with post-surgical pathology. Results：The accuracy of MRI diagnosis was 88.7% in p T1-2,83.0% in pT3 and 94.3% in pT4. The total accuracy of T staging was 83.0% and had good accordance with pathology （P〈0.01 ,kappa=0.582）. For N staging,the total accuracy was 81.1%,the specificity was 89.2%,the sensitivity was 62.5%,the positive predictive value was 71.4%,and the negative predictive value was 84.6%,N staging by MRI had good accordance with pathology. Conclusions：DWI combined with con- ventional MRI sequence has great value in pre-surgical T and N staging of colorectal cancer.