直肠癌表观扩散系数与MR动态增强定量参数的临床价值

目的：探讨直肠癌扩散加权成(DWI)表观扩散系数(ADC)值和MR动态增强定量参数的临床价值。材料与方法47例直肠癌患者和16名健康志愿者行DWI(b值分别为0 s/mm2、800 s/mm2)和MR动态增强扫描。(1)ADC值测量：在b值800 s/mm2上获ADC图，对病灶低信号区进行三个点位测量，取三个感兴趣区点位ADC值平均值，即ADCmean。(2)采集动态增强数据输入工作站，通过血液双室模型(Tofts模型)软件，得出血流动力学参数：Ktrans、Kep和Ve。独立样本比较t检验，相关性Pearson分析。P<0.05为差异有统计学意义。结果直肠癌组ADCmean、Ktrans、Kep均值分别为：0.8835×10－3 mm2/s、2.6680 min-1、4.7089 min-1；健康组ADCmean、Ktrans、Kep均值分别为：1.34×10－3 mm2/s、1.548 min-1、2.39 min-1。直肠癌组与健康组间ADCmean、Ktrans、Kep的差异有统计学意义(P值均<0.01)。直肠癌组ADCmean与Ktrans、Kep的Pearson相关性P值>0.05，无统计学意义。结论 DWI的ADCmean和动态增强定量参数Ktrans、Kep能有效、定量区分直肠正常组织与癌肿组织，可作为直肠癌影像学生物标记物。

Clinical value of apparent diffusion coefifcient and quantitative parameters of MR dynamic enhancement of rectal cancer

Objective: To study the clinical value of diffusion weighted imaging (ADC) and MR dynamic enhanced quantitative parameters of rectal cancer. Materials and Methods:Forty-seven patients of rectal cancer and 16 healthy volunteers underwent multiple b value diffusion weighted imaging (b values respectively 0, 800 s/mm2) and MR dynamic enhanced scanning (adopting the technology of LAVA ISO). (1) ADC values were measured, ADC map was obtained at b 800 s/mm2, three points of interest were measured on the lesions, and ADCmean was the average value. (2) Dynamic enhanced datas were inputted to workstation, and the homodynamic parameters, such as Ktrans, Ve and Kep, were obtained by the dynamic model software. The comparison of the two sample by t test. The Pearson analysis of correlation. The significant threshold was set as P<0. 05. Results:ADCmean, Ktrans and Kep mean of the tumor group were respectively 0.8835×10-3 mm2/s and 2.6680 min-1, 4.7089 min-1, the healthy group respectively 1.34×10-3 mm2/s, 1.548 min-1, and 2.39/min. It was respectively statistically signiifcant in rectal cancer group and healthy group (P values<0.01). And Pearson correlation was not statistically significant (P values>0.05). Conclusions:DWI ADCmean and dynamic enhanced quantitative parameters Ktrans and Kep can effectively distinguish tumor or normal rectal tissue quantitatively, and can be the biomarkers of the rectal cancer in the imaging.