颈段脊髓前动脉64层CT血管成像

Application of 64-slice CT angiography of cervical anterior spinal artery

目的探寻64层CTA行颈段脊髓前动脉（ASA）成像的可靠检查方案。方法回顾性分析接受常规头颈部CTA检查（小剂量峰值测量确定扫描时间,对比剂剂量1.5 ml/kg体质量,注射速率5 ml/s）的45例患者的ASA显影情况,将其分为两组：A1组：ASA显影良好;A2组：ASA显影较差或未见显影。测量小剂量对比剂预试验中C6椎体平面椎动脉的CT值峰值,并进行比较。对20例临床要求了解ASA情况的患者行颈段ASA CTA,对比剂剂量2.0 ml/kg体质量,注射速率5 ml/s,根据基底动脉水平小剂量对比剂预试验到峰值后加4~6 s延迟扫描,分析ASA的显影情况。对ASA及前根动脉的显示情况进行目测评分。结果 45例常规头颈部CTA中,26例ASA显影良好（A1组）,19例显影较差（A2组）,ASA显示率为57.78%（26/45）。A1、A2两组椎动脉的CT值峰值分别为（234.52±10.16）HU和（212.65±12.38）HU（P〈0.05）。20例ASA CTA中,17例（17/20,85.00%）ASA显示满意;ASA CTA能清楚显示ASA及前根动脉的受压及损伤情况,对ASA及前根动脉的显示明显优于常规CTA检查（P〈0.05）。结论椎动脉血流动力学对颈段ASA的显示影响显著;颈段ASA CTA应适当增大对比剂剂量并延迟扫描。

Objective To explore the reliable protocol of 64-slice CTA of cervical anterior spinal artery（ASA）.Methods ASA of 45 patients underwent routine head and neck CTA（1.5 ml/kg,5 ml/s） were retrospectively analyzed.All the patients were divided into two groups： ASA was well risualized in A1 group and not well in A2 group.CT peak values of vertebral artery at C6 were measured and compared.CTA of ASA（1.5 ml/kg,5 ml/s,4—6 s delayed） were performed in other 20 patients,and the imaging qualities of ASA were analyzed and double-blind visual scored.Results Among 45 patients underwent routine head and neck CTA,ASA was well visualized in 26（A1 group）,while was not well visualized in 19 patients（A2 group）.The display rate of ASA was 57.78%（26/45） in routine head and neck CTA.CT peak values in A1 group and A2 group was（234.52±10.16）HU and（212.65±12.38）HU,respectively（P0.05）.Among 20 patients underwent ASA CTA,ASA was well visualized in 17 patients.The display rate of ASA was 85.00%（17/20）,better than that of routine CTA（P0.05）,while the injuries of ASA and anterior radicular artery were showed clearly with ASA CTA.Conclusion The hemodynamics of vertebral artery could obviously impact the display of cervical ASA during CTA.The dose of contrast agent should be increased to visualize ASA,and the start time of scanning should be appropriately delayed.