自发性肠系膜上动脉夹层MSCTA诊断

目的通过分析自发性肠系膜上动脉夹层病例资料,提高对该疾病的认识。方法应用MSCT对5例急症患者进行平扫描和增强扫描,结束后将图像传输至工作站后处理,应用容积再现(VR)、曲面重建(CPR)、最大密度投影(MIP)等方法观察血管情况。结果 5例患者在重建图像上均清晰显示出肠系膜上动脉及其分支。轴位示肠系膜上动脉内真假腔影,并能清晰显示低密度的内膜瓣,与主动脉夹层的真假腔相类似。CPR及MPR上可显示条形低密度充盈缺损影,亦可清楚显示内膜瓣。VR图像可以显示双腔改变。MIP图像与VR图像相似。5例均仅显示1处破裂口,而非像主动脉夹层显示两处或多处破裂口。其中1例病例远端肠系膜上动脉栓塞,并合并肝总动脉动脉瘤,1例病例近端、远端肠系膜上动脉栓塞,1例合并右肾动脉分支夹层。结论 MSCTA可早期诊断自发性肠系膜上动脉夹层。

MSCTA diagnosis of spontaneous dissection of the superior mesenteric artery

Objective To analyse cases of spontaneous dissection of the superior mesenteric artery for better understanding of this disease.Methods Five emergency cases(4 males and 1 female,aged 46~78,with an average age of 56.4) were chosen from the time from Oct.2008 to Aug.2010.TOSHIBA AQUILION 16-Slice Spiral CT or GE Lightspeed 64-Slice VCT was applyed for scanning,ranging from aortic arch to pubic symphysis.Scanning conditions were as follows 120 kV,300 mA,1 mm slice thickness or 120 kV,500 mA,0.625 mm slice thickness.100 ml iohexol(350 mgI/ml) was injected from the elbow vein at 3.5 ml/s.Tracking injection of 40 ml normal saline was made at the same rate.23 s was delayed before scanning.After scanning,image was reconstructed with 1 or 0.625 mm slice thickness and transmited it to workstation.The artery was observed by VR,CPR and MIP etc.Results The reconstructed images of all the five cases clearly showed the superior mesenteric artery and its branches.The axial scan showed the true and false lumen in the superior mesenteric artery,similar to that in the aortic dissection,and clearly showed the intimal flap of low density.CPR and MPR can also show strip filling defect of low density and clearly show the intimal flap.VR image can show double lumen change.MIP image was similar to VR image.Every case of the five only showed one cleft,different from aortic dissection which showed two or more clefts.One case had distal superior mesenteric artery embolism,complicated with common hepatic artery aneurysm.One case had subterminal and distal superior mesenteric artery embolism.One case was complicated with right renal artery branch dissection.Conclusion MSCTA can early and accurately diagnose superior dissection of the mesenteric artery.