正常肠系膜上动脉的MSCTA表现

The evaluation of MSCTA performance of superior mesenteric artery in normal adults

目的:探讨正常成人肠系膜上动脉(SMA)的MSCTA表现。方法:搜集2008年1月-2010年12月行全腹MSCT双期增强扫描、且SMA及其分布区域未见明显异常者266例。在动脉期图像上进行最大密度投影(MIP)、容积再现(VR)、多平面重组(MPR)等后处理重组出SMA的二维、三维图象,观察其起源位置及其分支分布走行,并测量统计以下数据:SMA起始位置;SMA与腹主动脉夹角;右结肠动脉、中结肠动脉及胰十二指肠下动脉显示率;回结肠动脉分支夹角;空、回肠动脉显示数目;左肾静脉层面及十二指肠水平部层面SMA后缘与腹主动脉前缘间的距离。结果:SMA走行及分布正常者259例,正常变异7例。241例(241/259,93.1%)SMA起源于L1椎体水平;SMA与腹主动脉夹角的平均值为57.1°±14.0°;中结肠动脉显示率31.7%(82/259),右结肠动脉显示率52.5%(136/259),胰十二指肠下动脉直接起自SMA主干68.4%(177/259);回结肠动脉分支夹角平均值为77.7°±28.7°;空肠动脉显示3～8支、回肠动脉1～6支;左肾静脉层面及十二指肠水平部层面SMA与腹主动脉间距的平均值分别为(16.2±7.2)和(17.5±7.4)mm。结论:MSCTA可直观显示SMA走行、分布及其与腹主动脉间夹角。

Objective：To investigate the MSCTA mal adults. Methods： 266 cases,in whom no lesions were imaging performance of superior mesenteric artery （SMA） in nor found in the SMA and its distribution area,were collected from Jan uary 2008 to December 2010 with dual-phase enhanced scan of whole abdomen. The reconstruction techniques including MPR （muhiplanar reconstruction）,MIP （maximal intensity projection） and VR （volume rendering） were used. Data were collected：Superior mesenteric artery origin, the angle between SMA and abdominal aorta （AA）, the frequency of appearance of right colic artery,transverse artery and inferior pancreaticoduodenal artery, the angle between ileocolic artery branches, the number of jejunal and ileal artery,the distance between SMA and AA on the left renal vein plane and the third part of duodenum plane. Results： Among the 266 cases,259 cases had normal shape and distribution of SMA and 7 cases had normal variation. 93.1 %of the superior mesenteric artery originated at the L1 vertebral level. The angle between SMA and AA was 57.1 % ± 14. 0 %. The frequencies of middle colic artery, right colic artery and inferior panereaticoduodenal artery were 31.7% ,52.5% and 68.4%, respectively. The angle between the two branches of ileocolic artery was 77.7 ± 28.7 . There were 3-8 jejunal arteries and 1-6 ileal arteries. The distance between SMA and AA was （16.2 ±7.2）mm on left renal vein plane and （17.5± 7.4）mm on the third part of duodenum plane. Conclusion： MSCTA can visualize SMA course, distribution and the angle between SMA and AA.