16层螺旋CTA成像技术在主动脉夹层动脉瘤中的应用

目的探讨16层螺旋CTA成像造影剂跟踪、造影剂测试及常规计算时间延迟技术在主动脉夹层动脉瘤中的应用价值。方法回顾性分析了88例主动脉夹层动脉瘤16层螺旋CTA血管成像,其中6例伴Stent支架治疗。造影剂量按1.5mL/kg,注射速率为3mL/s。扫描延迟时间按3种方法进行：①Bolustracking即造影剂跟踪扫描35例;②testBolus即造影剂峰值测试进行时间延迟28例;③常规计算时间组25例。3组图像分别由高年资医师阅片,比较3种方法的差异。准直器宽度1.25mm,重建层厚1.5mm,扫描范围从胸廓上缘至耻骨联合处。数据重建在3DWorkingStation用最大密度投影（MIP）及容积显示（VR）等。结果第一组35例和第二组28例经MIP及VR等成像,所有夹层动脉瘤均能清晰显示真假腔,并可见受累的血管部位及程度,并可见Stent支架的长度和所在部位;第三组25例中,6例图像模糊;第三组与第一、二组图像质量有显著差异。结论 16层螺旋CTA在主动脉夹层动脉瘤成像中扫描延迟时间应用Bolus tracking和TestBlous为佳,常规计算延迟时间质量较差。

Application Value of 16 Multi-slice Spiral CT Angiography Imaging of Aortic Dissection

Objective To evaluate the value of 16 multi-slice spiral CT angiography imaging in aortic dissection and to find the best method to show the aortic dissection. Methods 88 cases of 16 multi-slice spiral CT angiography imaging in aortic dissection were retrospectively analyzed, including 6 cases with stent therapy. All the patients were injected contrast media by 1.5mL/kg, and the rate of injection was 3mL/s. Three ways of delay time were applied： the first was bolus tracking, the second was test bolus, and the third was calculating delay time. Data reconstruction were managed by VR（Volume rendering ）, MIP（Maximum Intensity Projection）, and so on in working-station. The images of 3 groups were read by two senior radiologists. Results Real and false cave and rupture cave in dissecting aneurysm were clear ,and it could show the size and location of stent in the first group of 35 cases and the second group of 28 cases, 6 cases images of 25 cases were not clear. The image quality of the third group was not better than the first group and the second group. Conclusion Bolus tracking and test blous were good methods in 16 multi-slice spiral CT angiography imaging of aortic dissecting aneurysm,while the calculating delay time was not a good method.