3.0TMRI扩散加权成像及动态增强对直肠癌T2及T3分期的诊断价值

Diagnostic value of the diffusion weighted imaging and dynamic contrast enhanced in T2 and T3 stage for rectal cancer with 3.0T MRI

目的:探讨3.0T磁共振扩散加权成像(DWI)及动态增强(DCE)对直肠癌T2期及T3期的诊断价值。方法28例经术后病理证实的直肠癌患者(T2期7例、T3期21例)术前均行3.0T MR DWI及DCE检查,比较两组间瘤体表观扩散系数(ADC)值、指数化表观扩散系数(eADC)值及DCE-MRI半定量参数(TTP、SER、MTE、PEI、MSI)的差异,对差异有统计学意义的参数值行受试者工作曲线(ROC)以确定其对T2及T3分期的诊断效能及鉴别的最佳临界值。结果直肠癌T2分期与T3分期平均ADC值、eADC值之间差异有统计学意义(P<0.01);动态增强半定量参数(TTP、SER、MTE、PEI、MSI)在T2分期与T3分期间差异无统计学意义(P>0.05);ROC曲线确定ADC值和eADC值诊断直肠癌T2期及T3期的临界值分别为1.024×10-3mm2/s和0.366 mm2/s,敏感性和特异性分别为85.7%和81.0%、81.0%和85.7%,曲线下面积分别为0.830和0.837。结论:DWI对直肠癌T2期和T3期的鉴别诊断具有较高的临床价值,而DCE-MRI对二者的鉴别诊断无明显价值。

Purpose:To investigate the diagnostic value of the diffusion weighted imaging(DWI)and dynamic contrast enhanced(DCE)in T2 stage and T3 stage of rectal cancer with 3.0T MRI.Methods:28 patients with rectal cancer[T2 stage(n=7)and T3 stage(n=21)]confirmed by postoperative pathology underwent preoperatiove DWI and DCE at 3.0T MRI.The differences in apparent diffusion coefficient(ADC)value,exponential apparent diffusion coefficient(eADC)value and semi-quantitative parameters of DCE(TTP、SER、MTE、PEI、MSI)were compared between two groups.Receiver operating characteristic(ROC)curves were used to determine the ability and threshold of the parameter value with statistical significance to the difference in differentiating two groups.Results:There were statistically significant differences with ADC value and eADC value between two groups(P<0.05),but no statistically significant differences in semi-quantitative parameters of DCE(TTP、SER、MTE、PEI、MSI)(P>0.05).The areas under the ROC of the ADC value and eADC value were 0.830、0.837,respectively.The threshold of ADC value was 1.024×10-3mm2/s,sensitivity and specificity were 85.7%and 81.0%in differentiating two groups.The threshold of eADC value 0.366mm2/s,sensitivity and specificity were 81.0%and 85.7%in differentiating two groups.Conclusion:DWI has high clinical value in the differential diagnosis of T2 stage and T3 stage of rectal cancer,while DCE-MRI has no obvious value.