磁共振弥散加权成像平均表观扩散系数和最小表观扩散系数与直肠癌临床病理特征之间的相关性

Correlation between mean apparent diffusion coefficient and minimum apparent diffusion coefficient on diffusion-weighted magnetic resonance imaging and clinicopathologic features of rectal cancer

目的本研究旨在探讨弥散加权成像平均表观扩散系数(MeanADC)和最小表观扩散系数(MinADC)与直肠癌临床病理特征之间的相关性,并评估MeanADC值和MinADC值在预测直肠癌发生的诊断潜力。方法手术前接受常规MR成像和弥散加权成像的直肠癌病例185例,根据弥散加权成像测量直肠癌癌灶的MeanADC值和MinADC值,并研究其与直肠癌T分期、N分期、肿瘤组织学分级、周围神经侵犯、壁外血管侵犯等临床病理特征的相关性。结果直肠癌扩散加权成像MeanADC值、MinADC值与T分期、N分期、肿瘤组织学分级(低分化、中分化、高分化)、周围神经侵犯、壁外血管侵犯有关;与性别、年龄、肿瘤位置无明显关系(P>0.05);与MeanADC值相比,MinADC值在鉴别高分化、低分化直肠癌的诊断效能更高(高分化以0.930×10-3 mm 2/s为截断值,敏感度80%、特异度88%,低分化以0.750×10-3 mm 2/s为截断值,敏感度94.0%、特异度74.1%)。结论MeanADC值和MinADC值均可作为评价直肠癌侵袭性的定量指标,与MeanADC值相比,MinADC值可以作为鉴别肿瘤分化程度更好地预测因子。

Objective To investigate the possible correlation between mean(MeanADC)and minimum(MinADC)apparent diffusion coefcient values with the clinicopathological features and evaluate the diagnostic potential of MinADC values and MeanADC values in predicting the behavior of rectal cancer.Methods A total of 148 pathologically veried lesions that were subjected to conventional MR imaging and diffusion weighted imaging prior to operation were included.The MeanADC values and MinADC values were calculated and their correlation with clinicopathological characteristics were investigated.Results Both MeanADC values and MinADC values correlated with T classi cation,N classication,tumor histological grade,perineural invasion,and extra-mural venous invasion in rectal cancer,but no significant correlation with gender,age,and tumor location(P>0.05).The MinADC values showed a higher diagnostic efcacy in discriminating the well or poor differentiation of rectal cancer compared to MeanADC values,with a threshold value of 0.930×10-3 mm 2/s(sensitivity:80%;specificity:88%)or 0.750×10-3 mm 2/s(sensitivity:94.0%;specicity:74.1%).Conclusion Both MeanADC values and MinADC values may be used as a quantitative parameter to evaluate the aggressiveness of rectal cancer.The MinADC values could be as the better predictor in identifying tumor differentiation compared to the MeanADC values.