目的　根据肝内肝门静脉的走形分布，提出肝脏分段的新概念，为影像学和肝脏外科提供资料。　方法　采用60例正常的活体肝移植供肝影像资料，研究右前叶肝内肝门静脉的走形和分布以及肝静脉及其属支的回流范围，10例Mevis三维软件重建图像，探讨两者之间的关系。　结果　Couinaud分段中的VIII段门脉支可大致分为腹侧支和背侧支，最多可达4支；约90%的背侧支越过肝右静脉分布到Couinaud分段中的VII段。V段的门脉分支大多来自右前叶或VIII段门脉的腹侧支。因此，可将右前叶分为腹侧段：Couinaud分段中的VIII段的腹侧段（S8v）和V段（S5） 背侧段：Couinaud分段中的VIII段的背侧段（S8d）两个部分。　结论　新的划分方法不仅有利于肝内病变的精确定位，而且便于肝脏外科实施新的、更安全的术式。

Objective　To evaluate anatomic features of intrahepatic portal and hepatic veins of right anterior lobe of liver, and provide a new concept of the classification of hepatic segment for imaging diagnosis and liver surgery.　Methods　The data from successive section MRI of the upper abdomen from 60 living donors for liver transplantation and three-dimensional images of 10 patients were used in this study. The course and division pattern of the intrahepatic portal and hepatic veins, and their relationships were investigated. Results　The intrahepatic portal veins of eight hepatic segments can be mainly divided into ventral and dorsal branches, despite four branches could be found in some cases. About 90% dorsal branches supplied the dorsocranial area of the right lobe posterior to the right hepatic vein. Most branches of P5 gave off the right anterior trunk of P8v, and most drainage veins of S5 joined MHV. Therefore, the right anterior lobe could be divided into S8v+S5 (ventral segment) and S8d (dorsal segment). 　Conclusions　 This new concept of hepatic segment division will be helpful for the accurate allocation of lesion in the liver, as well for the development of the new and safe surgical procedures.