小剂量测试技术和对比剂团注跟踪自动触发技术在肺动脉CTA的对比研究

摘要

目的：对比研究小剂量测试技术和对比剂团注跟踪自动触发技术在肺动脉CTA诊断的意义。方法随机选取本院行肺动脉CTA检查的患者70例，将患者分成两组（每组35例），组1用小剂量测试技术扫描方式，组2用对比剂团注跟踪技术自动触发扫描，所有数据均在后处理工作站行多平面重组技术( multi planar reformatting, MPR)、最大密度投影(maximum intensity projection，MIP)和容积重现(volume rendering，VR)后处理，由两名高年资（主治职称以上）医生采用双盲法行主观评价，然后在工作站上测量肺动脉干、肺静脉和升主动脉CT值并应用统计学方法进行比较。结果两种扫描方式所获图像质量在主观评估方面无统计学意义（P>0.05）。两组图像的肺动脉干、肺静脉和升主动脉CT值差异有统计学意义（P<0.05），且小剂量测试扫描方法所用造影剂剂量更少。结论两种扫描方案（小剂量测试技术和对比剂团注跟踪自动触发技术）检查肺动脉所得图像中，主观影像质量评估无统计学差异，而客观影像质量评估（肺动脉干、肺静脉和升动脉CT值）有统计学意义（P<0.05），且小剂量测试扫描方式所用造影剂的剂量较少，故应用小剂量测试技术进行肺动脉CTA的检查具有重要的临床价值。%Objective To compare the value of test bolus technique and automatic bolus tracking technique in the pulmonary artery CT angiography (CTA).Method 70 cases of patients undergoing pulmonary artery CTA in our hospital were randomly selected. They were divided into two groups ( 35 cases in each group); group 1 was applied with test bolus technique, while group 2 was applied with automatic bolus tracking technique. All the data underwent MPR (multi planar reformatting), MIP (maximum intensity projection) and VR (volume rendering) in post-processing workstation and were subjectively evaluated by two high-qualified doctors holding the title of attending physician and above using double blind method. The CT value of pulmonary artery, pulmonary vein and the ascending aorta were measured and compared via statistical methods.Result Two types of scan image quality obtained in the subjective evaluation have no statistical significance (P > 0.05), while the differences between two sets of images of the pulmonary artery, pulmonary vein and artery CT value were statistically significant (P < 0.05). Moreover, the dosage of contrast agent in group 1 was lower than that in group 2.Conclusion It is of great clinical value to choose test bolus technique in the pulmonary artery CTA as the images of pulmonary arteries obtained from the two scanning methods (test bolus technique and automatic bolus tracking technique) on the basis of objective image quality evaluation (CT value of pulmonary artery, pulmonary vein and ascending artery) presented statistically significant differences (P < 0.05) though those on the basis of subjective image quality evaluation didn’t, and lower dose of contrast agent was used via test bolus technique.