【摘要】 目的 探讨扩散加权成像（DWI）及表观扩散系数（ADC）与直肠癌分化程度的相关性,以及在评估环周切缘（CRM）浸润中的价值。方法 选择经手术病理证实的直肠肿瘤患者共27例,行MRI常规序列及DWI序列检查,测量肿瘤的ADC值及肿瘤与CRM的距离。结果 直肠恶性肿瘤的平均ADC值为（0.938±0.151）×10^-3mm²/s,直肠腺癌高、中、低分化组平均ADC值分别为（1.153±0.077）×10^-3mm²/s、（0.966±0.09）×10^-3mm²/s、（0.774±0.038）×10^-3mm²/s,差异有统计学意义（P<0.01）。DWI判断CRM侵犯的敏感性、特异性、准确性、阳性预测值和阴性预测值分别为76.9%、80%、78.5%、76.9%和80%。CRM阳性患者平均ADC值为（0.876±0.11）×10^-3mm²/s,CRM阴性患者平均ADC值为（0.992±0.163）×10^-3m²/s,两者比较差异有统计学意义（P=0.042）。结论 DWI能够对直肠癌CRM浸润情况进行准确预测。ADC值与直肠癌分化程度有相关性,肿瘤的ADC值随着肿瘤的分化程度下降而减低。更多还原

【Abstract】 Objective To explore the value of the apparent diffusion coefficient（ADC） value of diffusion weighted imaging（DWI）in assessment of differentiation degree and circumferential resection margin（CRM）infiltration in rectal cancer.Methods 27 patients with pathologically proved rectal tumor were selected.All of them were underwent the routine MRI and DWI sequences.The ADC value of the tumor and the distance between the tumor and the CRM were calculated.Results The mean ADC value of the malignant tumors was（0.938±0.151）×10^-3 mm²/s.The mean ADC values of the well,moderately and poorly differentiated rectal tumors were（1.153±0.077）×10^-3 mm²/s,（0.96 6±0.09）×10^-3 mm²/s and（0.774±0.038）×10^-3 mm²/s,respectively.There was significant dif ference（P<0.01）.The sensitivity,specificity,accuracy,positive predictive value and negative predictive value of DWI in evaluating the invasion of CRM were 76.9 %,80%,78.5%,76.9% and 80%,respectively.The mean ADC values of CRM positive and CRM negative patients were（0.876±0.112）×10^-3 mm²/s and（0.992±0.163）×10^-3 mm²/s,respectively.There was significant difference（P=0.042）.Conclusion DWI can accurately predict the marginal margin infiltration of rectal cancer.There is correlation between the ADC value and the degree of differentiation of rectal cancer.The ADC value decreases with the reducing of the differentiation degree of tumor.更多还原