多层螺旋CTA:不同重建方法在主动脉瘤腔内隔绝术后的应用评价

目的：探讨多层螺旋CT血管造影不同重建方法在主动脉瘤腔内隔绝术后的临床应用价值。材料与方法：46例主动脉瘤腔内隔绝术后行多层螺旋CT血管造影，采用准直2.5mm，层厚3.0mm，螺距为6，重建方法为容积显示技术（volume rendering，VR）、表面阴影遮盖显示(shade surface display，SSD)及最大密度投影法（maximum intensity projection，MIP），并对三种方法进行比较。结果：46例中有1例术后内支架出现局限性断裂，VR及MIP均清晰显示了内支架的变化，SSD未能显示。1例内支架展开不良，三种重建方法均明确显示；6例术后出现渗漏，VR清晰显示渗漏的部位、形态及内漏量，MIP、SSD仅显示其中的5例，三者中以VR显示最佳。在显示支架内血流情况及瘤周血栓方面，VR能明确支架内有无血栓形成及腔内隔绝术后的转归变化，VR显示1例术后支架内血栓形成SSD及MIP未能显示。结论：多层螺旋CT能在较短时间内进行大范围的扫描，有利于主动脉病变的检查；VR图像优于SSD及MIP，能为术后内支架情况提供更多更准确的信息，VR技术应作为主动脉瘤内支架术后的首选三维重建方法。

Multi - slice CT Angiography of Aortic Aneurysms after Endoluminal Stent Grafts Theraphy:Comparison Study of Three Dimensional Reconstruction Techniques

Purpose: To evaluation the value of three dimensional reconstruction techniques of multi - slice CT an-giography of aortic aneurysms after endoluminal stent grafts theraphy.Materials and Methods: Multi -slice CT angiography was performed in 46 cases aortic aneurysms after endoluminal repair, 3D reconstruction techniques, including volume rendering technique(VR), SSD and MIP, was adopted, and the images thus obtained were compared with each other. Results:Of 46 cases in this study,partial graft split as occurred in one case and displayed on VR and MIP images; stent graft un - expandness was occurred in one cases and displayed on all images, perigraft leakage was occurred in 6 cases and all displayed on VR images,only 5 cases displayed on SSD or MIP images. Thrombosis within graft was occurred in one cases and only VR images demonstrated.Conclusion: Multi - slice CT can repidly scan large scale in short time, which is favourable for examining aortic disease. VR technique is superior to SSD or MIP in revealing the location and shape of the stent graft or the volume of perigraft leakage, and affording more-information for aortic aneurysms after endoluminal repair,which may be the preferred method.