肝硬化的磁共振扩散加权成像研究

Study on Diffusion Weighted Imaging in Cirrhotic Liver

目的 探讨肝硬化水分子扩散的变化及其机制。方法 对 5 9例志愿者及 47例肝硬化病人进行扩散加权成像并测量肝脏ADC值。DWI序列A的b值分别为 3 0、3 0 0、110 0s/mm2 ;序列B分别为 1.6和 5 5s/mm2 。序列A分别用b1和b3 (ADC1)及b2 和b3 (ADC2 )计算ADC值 ,序列B用b1和b2 (ADC3 )计算。结果 ChildB、C级肝硬化平均ADC3 明显低于正常肝脏 ,平均ADC1低于正常肝脏 ,平均ADC2 与正常肝脏无差别。结论 肝硬化ADC值降低的主要原因可能为肝实质内血流灌注的减少而非纤维化限制了水分子的热运动。

Objective To investigate the change of ADC value in cirrhotic liver and its mechanism. Methods Diffusion weighted imaging (DWI) was performed in 59 volunteers and 47 patients with liver cirrhosis, and the ADC values of the liver were measured. Two sequences were used in this study. The b values were 30, 300 and 1100s/mm 2 in sequence A, while 1.6s/mm 2 and 55s/mm 2 in sequence B respectively. Results The mean ADC 3 in Child B and C cirrhosis was significantly lower than that in normal liver, the mean ADC 1 was lower than that in normal liver, however, the mean ADC 2 was approximate between the two groups. Conclusion The main cause of ADC value reduction in the cirrhotic liver may not be limitation of motion of water molecules by fibrosis, but decreased blood perfusion in the liver.