16层螺旋CT颈脑动脉联合成像的技术评价

Technological assessment of combined CT angiography of carotid and cerebral arteries using 16-slice helical CT

目的:探讨16层螺旋CT颈脑动脉联合成像技术的可行性,评价其图像质量。方法:134例缺血性脑血管病患者应用SiemensSensation16层螺旋CT行颈脑动脉联合CTA检查。扫描准直16×0.75mm,Pitch值0.8～1.0,球管旋转时间0.5s/r。采用对比剂自动跟踪技术,对比剂使用Ultravist(370mgI/ml)100ml和30～40ml无菌生理盐水,注射流率3.5ml/s。于Wizard工作站参考DSA造影的操作顺序和投照角度,行颈脑动脉多平面重组、最大密度投影、曲面图像重建及容积再现CTA图像。技术分析包括扫描延迟时间及数据采集时间,分析图像质量。结果:134例CTA扫描延迟时间最快17.1s,最迟37.2s,平均21.5s,<20s者26例,20-30s者87例,>30s者21例;数据采集时间最少者13.1s,最多者为17.5s,平均15.6s,<15s者30例,>15s者104例。134例脑动脉CTA图像质量优者113例,质量好者16例,质量中等者5例,质量差者0例,无局部伪影病例,所有病例图像均满足诊断需要;颈动脉CTA图像,除11例患者存在局部伪影外,余123例图像质量均满足诊断需要。结论:应用16层螺旋CT可以在20s内完成颈部与脑动脉的一次性扫描,此技术是可行的;其CTA图像质量能够满足诊断需要。

Objective：To investigate the feasibility of combined CT angiography （CTA） of carotid and cerebral arteries using 16-slices helical CT, and assess its image quality. Methods： Combined CTA of carotid and cerebral arteries using 16-slices helical CT was performed in 134 patients with ischemie cerebrovaseular disease （ICD） with a collimation of 16×0.75 mm, pitch of 0.8 ×1.0, rotation time of 0.5 s/r. Contrast material of 100 ml Ukravist （370 mgI/ml） followed by 30-40 ml flush of sterile saline was administered at a rate of 3.5 ml/s using bolus tracking technology. CTA images of multiplanar reformation （MPR）, maximum intensity projection （MIP）, curved planar reformation （CPR） and volume rendering （VIi） were obtained on a Wizard workstation in a reference to operational sequence of DSA. Image analysis included time of scanning delay and time of data acquisition, and assessment of image quality. Results： The mean time of scanning delay was 21.5s （17.1-37.2 s）, with less than 20s in 26 eases, 20 -30 s in 87, more than 30s in 21. The acquisition time was 15.6 s （13.1-17.5 s）, with less and more than 15s in 30 and 104 eases, respectively. Of 134 eases, image quality of CTA of cerebral arteries was diagnostic without regional artifacts, and was excellent in 113, good in 16, fair in 5, and poor in 0. Image quality of CTA of carotid arteries was diagnostic in 123 eases except 11 cases with various regional artifacts. Conclusion： Combined CTA of carotid and cerebral arteries using 16-slices helical CT was feasible with an acquisition time of less than 20s, and its image quality was satisfactory and diagnostic.