多排螺旋CT肠系膜血管造影诊断急性肠缺血

CT angiography of mesenteric vessels in acute mesenteric ischemia

目的探讨多排螺旋CT肠系膜血管造影（MDCTA）在急性肠缺血（AMI）中的应用价值。方法对43例经临床或手术、病理证实的AMI患者行全腹MDCT平扫、动脉期和门脉期扫描，准直为0．6mm，采用容积重建（VR）、最大密度投影（MIP）及薄层最大密度投影（TSMIP）技术进行肠系膜动脉和静脉成像，重点观察肠系膜血管的异常表现、肠道和肠系膜异常征象。结果导致AMI的原因为：肠系膜上动脉（SMA）栓塞4例，SMA血栓形成6例，肠系膜上静脉（SMV）血栓形成13例，SMA夹层5例，绞窄性肠梗阻10例，血管炎5例。MDCTA可清晰地显示AMI的血管异常，如血管堵塞、狭窄或夹层的部位、形态、程度和范围；显示血管走向的异常，如聚拢、推移、扭曲或扭转等；并显示侧支血管。MDCTA可明确AMI的原因，如粥样硬化斑块、栓子、血栓形成、夹层、肿瘤血管侵犯、绞窄性肠梗阻和血管炎等。结论MDCTA能很好地显示AMI的直接征象，结合间接征象可在病变早期诊断AMI并明确病因。

Objective To evaluate mesenteric multidetector row CT angiography （MDCTA） in the diagnosis of acute mesenterie isehemia （ AMI ）. Methods In this study, 43 cases of AMI proven by clinical criteria, or operation and pathology underwent whole abdomen MDCT precontrast, arterial phase and venous phase scan with 0. 6 mm collimation. The mesenteric arteries and veins were reconstructed by using volume rendering （VR）, maximum intensity projection （MIP）, thin slab maximum intensity projection （TSMIP） techniques, and abnormal CT angiography findings as well as abnormal bowel and mesentery were analyzed. Results It was found that AMI was caused by superior mesenterie artery （SMA） embolism （ n = 4） , SMA thrombosis （ n = 6 ） , mesenteric and portal venous thrombosis （ n = 13 ） , SMA dissection （ n = 5 ）, strangulated bowel obstruction （ n = 10 ） and vasculitis （ n = 5 ）. MDCTA showed clearly the position, shape, severity and extent of the vascular occlusion, narrow and dissection. It could also demonstrate the abnormal course and direction of the vessels including vascular gathering, shift, tortuosity, retortion, and twist. Furthermore, the pathogenesis of various conditions including atheroselerotic plaque, emboli, thrombosis, dissection, tumorous invasion, strangulated bowel obstruction and vaseulitis could be identified by MDCTA. Conclusion MDCTA can clearly demonstrate direct signs leading to AMI, and identify AMI and its etiology at early stage, with the combination with its indirect findings.