宫颈癌扩散加权成像表观扩散系数与磁共振动态增强定量参数的临床价值

目的探讨磁共振扩散加权成像表观扩散系数(apparent diffusion coefficient,ADC)值和MR动态增强定量参数联合应用在宫颈癌诊断中的临床价值。材料与方法对100例宫颈癌患者和20例健康志愿者行常规MRI、扩散加权成像(diffusion weighted imaging,DWI)和MR动态增强扫描。(1)测量ADC值:在DWI b=800 s/mm~2上获取ADC图,对病灶低信号内取3个感兴趣区点位ADC值平均值,即ADC_(mean)。(2)将采集到的动态增强图像输入后处理工作站,通过血液双室模型(Tofts模型)软件,得出血流动力学参数:K~(trans)、K_(ep)和V_e。独立样本比较t检验,比较采用直线回归分析,绘制ROC曲线分析K~(trans)、K_(ep)和ADC_(mean)联合应用对宫颈癌的诊断效能。P0.05为差异有统计学意义。结果宫颈癌组ADC_(mean)、K~(trans)、K_(ep)、Ve均值分别为:(0.8600±0.1608)×10-3 mm2/s、(2.6650±1.4750)/min、(4.0369±2.1073)/min、0.4875±0.2336;健康组ADC_(mean)、K~(trans)、K_(ep)、V_e均值分别为:(1.3495±0.1543)×10-3 m m2/s、(0.9086±0.4922)/min、(1.3689±0.5214)/min、0.4204±0.2771。直线回归分析:ADC_(mean)与K~(trans)、ADC_(mean)与Kep、K~(trans)与Kep间的P值均0.05,有统计学意义;V_e各P值0.05,无统计学意义。ROC曲线进一步分析ADC_(mean)和K~(trans)、Kep联合应用诊断宫颈癌效能,当阈值为-0.6时,ADC_(mean)、K~(trans)和Kep敏感度和特异度分别为:98%和100%,98%和75%,100%和90%。结论宫颈癌的ADC_(mean)和动态增强定量参数K~(trans)、K_(ep)能作为癌肿影像学诊断可靠标记物,联合应用可以提高正确诊断率。

Clinical value of diffusion weighted imaging apparent diffusion coefficient and quantitative parameters of MR dynamic enhancement of cervical cancer

Objective:To investigate the clinical significance of diffusion-weighted imaging apparent diffusion coefficient (ADC) values and MR dynamic contrast-enhanced quantitative parameters in cervical cancer.Materials and Methods:One hundred patients with cervical cancer and 20 healthy volunteers were performed by diffusion-weighted (with b-value of 0 s/mm2 and 800 s/mm2) and dynamic contrast-enhanced MRI scanning. (1) Measuring the ADC values: ADC map was obtained when b-value was 800 s/mm2. When three interesting points were measured in the lesions, ADCmean was served as the average value. (2) Inputting the dynamic enhanced data to the workstation: Homodynamic parameters, such as Ktrans, Kep and Ve, were obtained by the dynamic model (Tofts model) software. The comparison of the independent samples was accomplished by thet-test. Using linear regression analysis and drawing ROC curve, the effectiveness which commixed by Ktrans, Kep and ADCmean to the diagnosis of cervical cancer can be analyzed. The signiifcant threshold was set asP<0.05.Results:The ADCmean and mean values of cervical cancer group Ktrans, Kep and Ve were respec tively(0.8600±0.1608)×10-3 mm2 /s, (2.6650±1.4750)/min, (4.0369±2.1073)/min and 0.4875±0.2336; But those in healthy group were (1.3495±0.1543)×10-3 mm2/s, (0.9086±0.4922)/min, (1.3689±0.5214)/min and 0.4204±0.2771. The linear regression analysis showed thatPvalue between ADCmean and Ktrans (or ADCmean and Kep or Ktrans and Kep) was less than 0.05, which was signiifcant statistically; That VeP value is greater than 0.05, which was no signiifcant statistically. Furthermore the ROC curve was utilized to analyze the effectiveness of cervical cancer which commixed by Ktrans, Kep and ADCmean. When the threshold value was 0.6, the sensitivity and speciifc degrees of ADCmean, Ktrans and Kep were 98% and 100%, 98% and 75%, 100% and 90%, respectively. Conclusion:ADCmean and dynamic enhanced quantitative parameters (Ktrans and Kep) could be treated as the reliable markers for diagnosis of cervical cancer in the MR imaging. The combinational applications could improve the diagnostic rate.