16层螺旋CT触发技术在颈部动脉CTA中的临床应用

目的:探讨16层螺旋CT团注追踪触发技术在颈部动脉CT血管成像(CTA)中的应用价值。方法:9例志愿者行主动脉弓同层动态增强扫描,利用获得的主动脉弓时间-密度曲线(TDC),寻求触发技术的理论阈值。将28例患者随机分为4组(触发阈值分别为110 HU1、40 HU1、70 HU2、00 HU),采用16层螺旋CT结合触发技术行颈部动脉CTA检查,探讨CTA触发技术的最佳应用阈值。结果:阈值140 HU组(参照组),颈总动脉、颈内动脉及椎动脉全程强化明显(CT值188~262 HU),而颈内静脉强化不明显,动静脉密度差别大,3D后处理显示的动脉图像清晰。阈值110 HU组,椎动脉起始处CT值较低(106 HU);阈值170 HU及200 HU组,C1及C5椎体平面颈内静脉的密度明显升高(>150 HU),与参照组比较差异有极显著性意义(P<0.01)。结论:16层螺旋CT血管成像中触发技术结合最佳触发阈值可较好地显示颈总动脉、颈内动脉及椎动脉;对比剂注射流率4.0 ml/s,触发阈值为140 HU时的图像质量较好。

Clinical Application of the Bolus-triggered Technique with 16-slice Spiral CT in CT Angiography of Cervical Arteries

Objective:To evaluate the clinical application of the bolus triggered technique with 16-slice spiral CT in CT angiography(CTA) of cervical arteries.Methods:Dynamic CT scan was performed in 9 volunteers,measuring the CT value of the same plane of aortic arch and the theoretical threshold was obtained by the time density curve(TDC).28 patients were divided randomly into four groups,taking triggered threshold as 110HU,140HU,170HU and 200HU respectively.Using the same CT protocol as that for volunteers,CTA of cervical arteries were performed in order to study the best time-point for triggered threshold.Results:Taking the group using 140HU as the threshold for reference,the common carotid artery,internal carotid artery and vertebral artery enhanced markedly through the whole course(CT value 188~262HU),remarkable density differences between artery and vein were showed.The arteries were clearly assessed in 3D reconstruction images.Taking 110 as triggered threshold,the CT value at the origin of vertebral artery was relatively low(106HU).Taking 170HU and 200HU as the threshold,the CT attenuation of internal jugular vein at the plane of C_1 and C_5 vertebral body was much higher than that of the reference group with significant statistical difference(P<0.01).Conclusion:Using 16-slice spiral CT triggered technique for CTA of cervical vessels,the common carotid artery,internal carotid(artery) and vertebral artery can be clearly showed.The image quality of the cervical arteries acquired with 4.0ml/s as injection rate and 140HU as threshold was better than the others.