三低技术联合生理盐水技术在头颈部CTA的应用价值

目的 为降低患者辐射剂量、减少对比剂副作用,探讨三低技术(即低管电压、低剂量、低浓度)联合生理盐水技术在256层CT头颈部血管成像(CTA)中的应用价值。方法 随机将120例头颈部血管成像(CTA)患者平均分为3组:A组采用120 kV、350 mgI/L对比剂60 ml,B组采用120 kV、320 mgI/L对比剂50 ml,C组采用100 kV、300 mgI/L对比剂40ml;流速均采用4.5 ml/s;采用对比剂跟踪技术,阈值为110 HU;3组均在注射完对比剂后以相同速率注射生理盐水40 ml。图像后处理采用VR、MPR、CPR、MIP;测量颈动脉不同水平CT值,观察锁骨下静脉、头臂静脉有无残留对比剂造成的伪影,统计每个病人接受的辐射剂量。结果 3组病例颈动脉内对比剂浓度均大于250 HU以上,无统计学意义(P < 0.05);3组图像均满足诊断要求;但在锁骨下静脉和头臂静脉残留对比剂的干扰方面存在差异,差异具有统计学意义(P < 0.05),C组图像质量明显优于A、B组;且辐射剂量减少12.83%~13.12%。结论 三低技术联合生理盐水技术在256层头颈部CTA成像中是可行的,既能保证图像质量、降低辐射剂量和对比剂用量,又能满足诊断要求。

Value of Three-Low Technique Combined Saline in CTA of the Head and Neck

Objective To investigate the value of three-low technique(low tube voltage. low-dose and low-concentration contrast) combined saline in 256-slice CTA of the head and neck,which can reduce radiation dosage and adverse effect of contrast. Methods 120 cases examined by CTA in the head and neck were divided into 3 groups:Group A scanning parameters:120 kV and amout of contrast agent:350 mgI/L,60 ml; Group B scanning parameters:120 kV and amout of contrast agent:320 mgI/L,50 ml; Group C scanning parameters:100kV and amout of contrast agent:300 mgI/L 40 ml; The rate was 4.5 ml/s,with bolus trigger technique. The threshold was 110 HU; 40 mL saline was injected in the same rate after injecting contrast. Imaging postprocessing techniques include VR, MIP, CPR, MPR; Measure CT values of the different level of Carotid arteries; observe the artifact of the remaining contrast in the subclavian vein and brachiocephalic vein,and record radiation dosage of patients. Results All CT values of the contrast in Carotid arteries were more than 240 HU. There was no statistical difference among three groups. All images could meet the diagnostic requirements. The artifact of the remaining contrast in the three groups,the image quality of group C was better than those of group A and group B. The radiation dosage reduced to 12.83~13.12%. Conclusion Application of the low tube voltage. low-dose and low-concentration contrast combined saline in 256-slice CTA of the head and neck was feasible. It is not only improve the image quality,reduce radiation dosage and amout of contrast, but also meet the diagnostic requirements.