IVIM参数与ADC值评估直肠腺癌分化程度的比较

Comparison between IVIM parameters and ADC value in rectal cancer for estimate histological grade

目的评估体素内不相干运动(intravoxel incoherent motion,IVIM)扩散加权成像参数与ADC值在直肠腺癌分化程度中的诊断价值比较。材料与方法回顾性分析93例直肠腺癌患者的影像和病理资料。测量肿瘤的IVIM参数(D、D*、f)和表观扩散系数(apparent diffusion coefficient,ADC)值。采用单因素方差分析比较不同分化程度直肠癌各参数的差异,并用受试者工作特征(receiver operating characteristic,ROC)曲线评价各参数的诊断效能。采用Spearman相关分析比较各参数与直肠癌分化程度间的相关性。结果随着直肠腺癌分化程度的降低,ADC值和D值显著性降低(P值分别为0.032和0.000),f值显著性增高(P=0.025)。D值鉴别高/中分化与低分化直肠癌的AUC最高,以2.465×10^-3 mm^2/s为阈值鉴别低分化直肠癌的敏感性和特异性分别为66.7%和79.6%。D值与直肠癌分化程度呈中度相关,ADC值、f值与直肠癌分化程度呈弱相关,相关系数|r|分别为0.441、0.249和0.246(P均<0.05)。结论IVIM参数与ADC值对鉴别不同分化程度的直肠腺癌均有较大的价值,D值的诊断效能更高。

Objective:To compare the value between intravoxel incoherent motion(IVIM)parameters and ADC value in assessing the histological differentiation grade of rectal adenocarcinoma.Materials and Methods:Ninety-three patients of rectal adenocarcinoma were enrolled and were analyzed MR images retrospectively.The parameters from IVIM(D,D*,f)and ADC value were measured.All parameters between different differentiation grade of rectal adenocarcinoma were compared.ROC analysis was used to assess the diagnostic performance in distinguishing well/moderately and poorly differentiated.Spearman correlation analyses were used among the IVIM parameters and histological differentiation grade.Results:There were significant differences in terms of ADC,D and f value between different differentiation grade of rectal adenocarcinoma(P=0.032,0.000,0.025 respectively).D value achieved the highest AUC in distinguishing well/moderately and poorly differentiated,when a cutoff value was 2.465×10^-3 mm^2/s,the sensitivity and specificity were 66.7%and 79.6%.The D value exhibited a moderate relationship with differentiation grade of rectal adenocarcinoma with|r|value of 0.441.The ADC and f value exhibited a poor relationship with differentiation grade,which|r|value were 0.249 and 0.246 respectively(all P<0.05).Conclusions:Both parameters from IVIM and ADC value could be helpful in differentiating histological differentiation grade of rectal adenocarcinoma.D value achieved the better diagnostic performance.