摘要目的 探讨膈下段腔静脉旁局限性脂肪积聚的多层螺旋CT多平面重组表现.方法 回顾性分析8246例胸腹部MSCT图像,45例横断面影像初步诊断有IVCfat者进一步行MPR证实,观察其好发部位及与下腔静脉(IVC)的关系；冠状重组像上IVC与IVCfat边缘成锐角者为腔内型,成钝角者为腔外型.随机选取同时期MSCT检查图像上膈下段腔静脉旁无类似于腔内肿块样脂肪密度影者50例作为对照组.IVCfat组和对照组间下腔静脉矢状倾角(SIA)、膈上、下段下腔静脉直径比值(DR)差异采用t检验比较.结果IVCfat的检出率为0.55％ (45/8246).肝静脉陷窝8例、IVC内侧膈下间隙28例,IVC沟9例.IVCfat形态横断面上主要呈类圆形、椭圆形及半月形,15例腔内型中4例呈“靶征”；MPR上以半月形为主.IVCfat组的SIA和DR分别为21.62.±8.42.和2.01 ±0.84,对照组分别为16.75.±7.82.和1.31 ±0.28,DR的差异有统计学意义(t=2.341,P＜0.05),SIA的差异无统计学意义(t=1.594,P＞0.05).结论 膈下段腔静脉旁类似于腔内的类圆、椭圆或半月形局限性脂肪密度影是IVCfat的特征性表现.

abstractsObjective To discusses the MSCT multiplanar reconstruction manifestation (MPR) of localized fat collection adjaction to subdiaphragmatic inferior vena cava (IVCfat).Methods The thoracic and abdominal MSCT scan data of 8246 patients were browsed,45 patients with presumed IVCfat on axial CT scans were further studied prospectively with MSCT MPR.The predisposing position of IVCfat and its relationship with IVC were observed.It was divided into two kinds of intraluminal type and extraluminal type according to the angle of IVCfat with respect of the wall of IVC.The other 50 patients without IVCfat were randomly selected as the control group.The sagittal inclination angle (SIA) and diameter ratio (DR) between supra- and sub-diaphragmatic IVC between the two groups were compared by using t test.Results The detection rate was 0.55％ (45/8246).Of which hepatic vein lacuna 8 patients,subdiaphragmatic gap medial to IVC 28 patients and IVC groove 9 patients.The shape of IVCfat showed mainly for the round,oval and crescents on axial CT scans,of 15 patients intraluminal type,4 showed "target signs ".The shape of IVCfat showed mainly for "half-moon" at MPR.The SIA and DR at IVCfat group were 21.62° ± 8.42°and 2.01 ±0.84 respectively,at control group were 16.75° ±7.82°(t =1.594,P ＞0.05) and 1.31 ±0.28(t =2.341,P ＜ 0.05 ) respectively.Conclusion The round,oval or half of limited fat density shadow adjaction to subdiaphragmatic inferior vena cava which similar to in the lumen is the characteristic performance of IVCfat,it may be an anatomical variation.