水表观扩散系数在预测和评价肝癌化疗栓塞术中的价值

目的 探讨水表观扩散系数(ADC)在肝癌化疗栓塞术前后的变化及其在预测和评价栓塞疗效中的价值.方法 对化疗栓塞术前和术后的肝癌患者进行磁共振扩散加权成像(DWI)检查(弥散系数为0和500 s/mm2)计算肝癌病灶手术前、后的ADC值,并与化疗栓塞效果比较.结果 栓塞不良组的术前ADC值(1.687×10-3 mm2/s)高于栓塞良好组(1.278×10-3 mm2/s,P<0.05).采用ROC曲线分析,以ADC值1.618×10-3 mm2/s作为预测栓塞不良阈值,其敏感度为96.0%,特异度为77.8%.栓塞良好组治疗前后的ADC变化比值(32.6%)高于栓塞不良组(5.2%,P<0.05).采用ROC曲线分析,以治疗前后的ADC变化比值16.2%作为预测栓寨效果良好阈值,其敏感度为72.0%,特异度为100%.非治疗叶段肝实质和脾脏治疗前后ADC值无变化(P>0.05).结论 ADC值能预测肝癌栓塞治疗效果,肝癌病灶ADC值高预示栓塞效果不良,而栓塞效果良好的病灶,其栓塞后的ADC值明显上升.对指导临床治疗方式的选择和个性化治疗方案的制定有一定意义.

Water mobility of diffusion MRI in prediction of response to chemoembolization in liver cancer

Objective To investigate the value of pretreatment and posttreatment changes of apparent diffusion coefficients (ADCs) in predicting response to chemoembolization in liver cancer. Methods Patients with liver cancer were examined with diffusion-weighted MRI at two b values (0 and 500 s/mm2) before and after chemoemblization. Quantitative ADC maps were calculated using images under b values of 0 and 500 s/ram2. The mean ADC values of lesions before and after chemoemblization were compared. The correlation of response to chemoembolization with ADC value was analyzed. Results The mean value of pretreatment ADC in non-responding lesions were significantly higher than that in the responding lesions (1.687×10-3 mm2/s vs. 1.278×10-3 mm2/s, P<0.05). The results of receiver operator characteristic (ROC) analysis showed that when a threshold ADC value was set on 1. 618×10-3 mm2/s, the sensitivity and specificity for identification of non-responding lesions were 96.0% and 77.8%, respectively. After transarterial chemoembolization, the responding lesions had a significant increase in ADC values than non-responding lesions (32.6% vs. 5.2%, P=0.025). The results of ROC analysis indicated that when the changes of ADC value for identification of responding lesions before and after transarterial chemoembolization was≥16.2%, the sensitivity and specificity were 72% and 100%, respectively. However, no significant change was observed in normal liver parenchyma and spleen (P>0.05). Conclusion Pretreatment mean ADC value can be used to predict the response to chemoembolization, and for selection of therapy in liver cancer. A significant increase in mean ADC can be observed if the lesions responds to chemoembolization.