小剂量测试技术在肺动脉CTA中对比剂注射优化方案的研究

摘要

Objective To compare test bolus and bolus tracking for determination of scan delay of high-pitch dual-source CT pulmonary angiography in patients with the same number of contrast material.Methods One hundred patients with suspected pulmonary embolism were randomized into 2 groups: bolus tracking technique group (group A, n=50) and test bolus technique group (group B, n=50). Image quality of the pulmonary artery was assessed by two independent readers. The enhancement value of pulmonary artery was measured, radiation dose estimates were calculated. The imaging quality of the pulmonary artery and the radiation dose were compared withMann­Whitney U andttest.Results The average image quality score [(1.35±0.63) in group A and (1.21±0.47) in group B] showed no significant difference between group A and group B (U=-3.28,P=0.001). The CT attenuation values of pulmonary artery in group A were higher than that in group B, there was statistically significant difference between two groups. The residue of contrast agent within the superior vena cava in group B was less than that of group A, with statistically significant difference between two groups.Conclusion Pulmonary angiography by using test bolus technology in dual-source CT high-pitch scan without another contrast agent can meet the requirement of the diagnosis.%目的：比较在相同对比剂用量下团注试验（test bolus）技术和团注造影剂跟踪（bolus tracking）技术在双源CT大螺距扫描肺动脉的图像质量。方法对100例临床可疑肺动脉栓塞的患者，根据随机表法将患者随机分为两组，每组50例。A组采用bolus tracking进行触发扫描，B组应用test bolus确定延迟时间扫描。由两名有经验的医师对两组图像质量进行评分，并记录测量值和辐射剂量。应用非参数检验和两独立样本的t检验比较两组患者的图像质量和辐射剂量。结果两组患者的总体图像质量评分[A组和B组总体图像质量评分分别为（1.35±0.63）和（1.21±0.47）]，差异有统计学意义（U=-3.28，P=0.001）。A组较B组肺动脉的强化CT值高，并具有统计学差异。而B组上腔静脉内残留的对比剂明显减少，其CT值较A组明显降低，并有统计学差异。结论双源CT大螺距扫描在不增加对比剂的情况下应用test bolus技术优化对比剂注射可获得好的肺动脉CT血管造影（CT Angiography，CTA）图像。