右房密度监测触发 CT 肺动脉成像

目的：通过对右房(RA)CT 值的监测,寻找其达峰时间,优化 CT 肺动脉成像(CTPA)显像。方法采集拟行 CTPA 的患者60例,随机分成2组,肺动脉触发(PT)组(n=30)：注射70 mL 对比剂(CA)并屏气,采用肺动脉干 CT 值监测触发方式获取CTPA 图像；RA 组(n=30)：注射40 mLCA,自由呼吸,并采用 RA 监测触发方式。对图像质量、肺动脉及肺静脉 CT 值、肺动脉-肺静脉密度差值等进行对比。结果RA 组图像质量、肺动脉平均值及肺动脉-肺静脉密度差明显高于 PT 组(P <0.05),而 RA 组肺静脉 CT 值更低(P <0.05)。肺动脉6级分支显示比例2组无统计学差异(P >0.05)。结论自由呼吸状态下基于 RA 密度监测触发的 CTPA 能在肺静脉 CT 值最低时使肺动脉得到最大强化,且 CA 使用量减少。

Computed tomography pulmonary angiography with right atrium bolus triggering

Objective To optimize the CT pulmonary angiography (CTPA)using right atrium (RA)CT value monitoring to determine the accurate time to peak CT value of pulmonary artery.Methods Sixty patients were randomly divided into two groups and 30 patients for each.Group PT:CTPA acquisition was triggered by pulmonary trunk monitoring,holding breath and 70 mL contrast agent (CA).Group RA:CTPA was performed using triggering from RA with spontaneous respiration and 40 mL CA.Imaging quality, average CT values of pulmonary arteries and veins,as well as their density difference were compared.Results The imaging quality, average CT values of pulmonary arteries and artery-veins density difference were significantly higher in group RA (P <0.05),while the CT values of pulmonary veins were significantly lower in group RA (P <0.05).No significant differences were showed in the proportion of subjects where sixth grade pulmonary arteries were opacified between the two groups (P >0.05).Conclusion CTPA imaging is optimized by triggering from RA CT value monitoring.This technique provides the optimal enhancement of pulmonary artery and minimal contrast filling of pulmonary venous with reduced doses of CA.