健康成人下腔静脉CT测量及其对肝肾间隙巨大肿块的定位诊断价值初探

CT measurement of inferior vena cava in normal adults and its value in determining the origin of large mass located in hepatorenal recess

目的:测量健康成人下腔静脉位置,并探讨下腔静脉推移征及其角度变化在肝肾间巨大肿块CT定位诊断中的价值。方法:在第一肝门水平CT图像上,沿椎体前缘作一水平线作为X轴,并紧贴此椎体右缘作与X轴垂直的Y轴,分别测量下腔静脉中心距离X、Y轴的长度及下腔静脉长轴与X轴的角度。所有径线均由2位主治医师独立测量,取其平均值进行统计学处理。回顾性分析经手术病理证实的68例位于肝肾间隙、直径大于4 cm肿块患者的影像学资料。对照正常标准探讨不同来源肝肾隐窝巨大占位性病变对下腔静脉推移的规律。结果:下腔静脉至X、Y轴距离无显著的年龄和性别差异(P>0.05),是一个较恒定的值,各性别、年龄组95%上限均分别小于<2.5 cm1.0 cm。下腔静脉长轴与X轴的夹角为(31±5)°,无显著的年龄差异(P>0.05),但存在性别差异(P<0.05),但两者95%上限均<60°。肝右叶肿瘤易使下腔静脉夹角增大(68%)并向左移位(52%)。下腔静脉前移可见于任何肝肾间隙来源的肿瘤,但以右肾上腺占位多见(50%)。结论:第一肝门水平下腔静脉的位置及其与X轴的夹角相对固定,下腔静脉移位及其角度变化是判断肝肾间隙巨大占位性病变来源的有价值的CT征象。

Objective.. Measurement of the position of inferior vena cava （IVC） of normal adults was performed on CT,and to study the significance of 1VC displacement and change of its angle in the localization of large mass within the hepatorenal recess. Methods： Abdominal CT was performed in 100 healthy human volunteers. At the level of the first liver hilus,a horizontal line along the anterior margin of vertebrae was drawn as X-axis, a line closely along the right side of ver tebral body and perpendicular to the X-axis was drawn as Y-axis. The distance between the center of IVC to the X axis and Y-axis as well as the angle between the long axis of IVC and X axis were measured. All of the dimensions were measured in dependently by 2 senior radiologists. The mean values were statistically analyzed. 68 patients had tumor mass within hepatorenal recess with the diameter 〉4cm and proven by surgery/pathology. Displacement of IVC in these patients were measured,and correlated with the normal data. The pattern of IVC displacement by these huge mass within hepato renal recess were retrospectively analyzed. Results： Of the distance between IVC and X axis/Y-axis,no significant statistical difference in various ages or gender groups were existed （P〉0.05）,which were rather stable 95% of the upper limits of various age group and gender were 〈2.5cm and 〈1.0cm respectively. The angle between the long axis of IVC and X axis was 31±5°, no significant difference was existed in different age groups （P〉0.05） but significant difference was existed in different genders （P〈0.05）. Yet 95% of the upper limits were 〈60°no matter in female or male. The angle of IVC could be enlarged （68%） and IVC could be displaced to the left （52%） in tumors of the right hepatic lobe. Anterior displacement of IVC could be seen in any mass within the hepato-renal recess,but most of them were right adrenal mass （50%）. Conclusion： The location of normal IVC and the angle between IVC and X-axis were relatively stable on CT images. Displacement of IVC and changing of the angle are valuable CT features in evaluating the origin of huge mass within hepaorenal recess.