磁共振扩散加权成像在肝癌介入治疗前后应用的初步研究

目的探讨肝癌经导管动脉化疗栓塞术(TACE)前后不同b值下瘤区组织的平均表观扩散系数(ADC)的变化及其意义。方法对17例临床及影像学诊断为肝癌并行介入治疗的患者,术前及术后7天行常规平扫和磁共振扩散加权成像,比较不同b值下瘤区组织的平均ADC值的变化。结果在b值为50和100s/mm2时术前术后比较无统计学意义。在b值为300、500和700s/mm2时,术前术后的平均ADC值变化有显著性差异。当b值大于300s/mm2时,随着b值的升高平均ADC值逐渐升高,术后瘤区组织的平均ADC值较术前升高,在b值为1000和1300s/mm2时图像质量太差无法测量。结论对肝癌TACE术后疗效进行评价时,b值最好选择300～700s/mm2之间。DWI通过瘤区DWI图像、eADC图像、ADC图像信号的变化和平均ADC值可以反映TACE术后瘤组织内的微观及超微结构的变化,平均ADC值可以为其早期疗效的判断提供量化标准。

MR diffusion-weighted imaging before and after TACE in liver cancer: a primary study

Objective To discuss the change and significance of mean apparent diffusion coefficient (ADC) value in different b value in tumor tissue before and after transcatheter arterial chemoembolization (TACE). Methods Preoperative and postoperative 7 days, conventional MRI and DWI were performed in 17 patients who were diagnosed hepatocellular carcinoma (HCC) and accepted TACE treatment. Results When b value was 50, 100 s/mm2, the change of mean ADC value is not statistically significant (P>0.05). When b value was 300, 500, 700 s/mm2, the change of mean ADC value has statistically significant (P<0.05). When b value was above 300 s/mm2, the mean ADC value step up gradually and postoperative tumor tissue mean ADC value was higher than preoperation. When b value was 1000, 1300 s/mm2, it was impossible to detect data because of poor picture quality. Conclusion To appreciate therapeutic effect of TACE for liver cancer, the b value range from 300 to 700 s/mm2 might be a better choice. DWI image, eADC image, ADC image and mean ADC value can reflect micro and ultrastructural change in tumor tissue after TACE. The mean ADC value is quantitative standardization of early-stage treatment in liver cancer.