多层螺旋CT及重建技术在主动脉夹层诊断中的价值研究(附23例报告)

The evaluation of MSCT and reconstruction in the diagnosis of aortic dissection

目的探讨多层螺旋CT及重建技术在主动脉夹层诊断中的价值。方法对疑有或确定有主动脉夹层的31例患者行CT血管造影（CTA）血管成像,使用美国GE lightspeed QX/I型多层螺旋CT（MSCT）行轴位容积扫描,扫描条件：120 kV、300 mA,5 mm准直器,7.5 mm/sec进床速度,HQ或HS扫描模式。重建层厚2.5 mm,重建间隔1.25 mm。用medped envision高压注射器,经静脉团注非离子型造影剂80-100 mm,注射流率为2.8~3.0 ml/s。重建后将数据传至GE advantage windows 4.0工作站进行二维和三维重建,对原始数据进行多平面重组（MPR）、最大密度投影（MIP）、表面遮盖法重建（SSD）、容积重建（VR）、CT仿真内窥镜重建（CTVE）及电影分析成像。观察主动脉夹层类型、形态、部位、真假两腔及分支血管的关系。结果发现主动脉夹层23例,其中Ⅰ型5例,Ⅱ型2例,Ⅲ型16例。23例主动脉夹层在轴位图像均可见充盈高密度的真腔和假腔,真腔小而密度略高于假腔,真、假两腔之间的低密度弧型影为撕破的内膜。在MIP、CTVE重建中发现18例主动脉夹层破口,附壁血栓9例,发现主动脉外壁溃疡破口5例,主动脉内膜钙化并内移〉5 mm11例。结论MSCT成像技术作为一种非损伤性的血管成像方法,具有安全、可靠和独特的优越性,可作为主动脉夹层治疗前最主要的影像学检查方法,价值可以肯定。

Objective To investigate the value of MSCT and reconstruction in the diagnosis of aortic dissection. Material and Methods CTA blood vessel imagery was performed on 31 patients who were doubted to have or had aortic dissection, and American GE light speed QX MSCT was used for Volume scanning, too. （Scanning condition： 120kV, 300mA, 5 mm collimator, 7.5 mm/sec table speed, HQ or HS scanning model. 2.5 mm reconstruction slice thickness, 1.25 mm reconstruction gap）. 80-100 ml non-iron contrast media was bolus-injected through vein by power inject at the speed of 2.8-3.0 ml/s. After the reconstruction, data was transferred to GE advantange the windows 4. 0 workstation to carry on 2D or 3D reconstruction. MPR, MIP, SSD, VR, CTVE and cine imaging were gained by raw data. Observe the type, shape, spot, the real and false channels and the relation of branch vessels of the aortic dissection. Results Discover the aortic dissection 23 examples. By the DeBakey, 5 cases were designated as having type Ⅰ ; 2 cases were type Ⅱ ; and the rest 16 cases were type Ⅲ. All the 23 cases of aortic dissections showed the real and false channel. The former was smaller and showed higher density than the latter. The arch-like hypodensity between the two channels were intimal flap ruptured. In MIP and CTVE there were 18 cases of dissections with rupture flap, 9 with mural plaque, 5 with rapture of aorta, and 11 with calcification and shifting inward of the aortic intimal flap. Conclusion As an imaging method of vessel, the imaging technique of MSCT is not injurious, and is secure and other unique advantages. And as the principal method in diagnosis of aortic dissection, the examination is conformed having great value.