颅脑CTA触发扫描技术的优化研究

Optimization of CT Angiography for the Intracranial Arteries with Triggering Scan Technique

目的探讨64层螺旋CT采用触发扫描技术对颅脑动脉造影的优化方法。资料与方法10名志愿者行主动脉弓层面的同层动态增强扫描,取得主动脉弓时间-密度曲线(TDC),得到触发扫描的理论阈值上限。将60例患者随机分为4组(触发阈值分别为90HU、120HU、150HU和180HU),行64层螺旋CT颅脑CTA检查,测量动、静脉CT差值。结果采用CT阈值120HU触发组,脑动、静脉密度差异最大,与其他组比较差异有统计学意义(P<0.05),且其后处理图像质量最佳。结论应用64层螺旋CT行颅脑CTA,在主动脉弓层面触发扫描并结合合理的扫描触发阈值,能够得到满意的颅内动脉图像。

Objective To investigate the optimization of the triggering scan technique using 64 slice spiral CT for intracranial arteries CT angiography （CTA）. Materials and Methods Dynamic CT scan was performed at the same aortic arch level in 10 volunteers for measuring the CT value and the theoretical threshold was obtained by the time density curve （TDC）. 60 patients suspected with intracranial artery dieases were divided randomly into four groups, taking triggered threshold as 90 HU, 120 HU, 150 HU and 180 HU respectively. The CT scanning protocol as that of volunteers were used for CTA of intracranial arteries. Results The group using 120 HU as the threshold for reference, remarkable density differences between artery and vein were showed, which had significant difference compared to other groups （P 〈 0.05 ）,and the quality of CTA images showed excellent. Conclusion Using 64 slice spiral CT for intracranial arteries CTA, the triggering scan technique at the aortic arch plane with appropriate triggered threshold could get excellent intracranial artery imaging.