MSCTA扫描触发方式对肺动脉图像质量的影响

摘要

目的 观察Test-Bolus法和Bolus-Tracking法两种扫描触发方式对MSCTPA图像质量的影响.方法 对568例疑诊肺动脉栓塞患者行CTPA检查,根据扫描前预注射实验时的肺动脉监测峰值分为A组(≥150 HU)和B组(＜150 HU),随机以Test-Bolus和Bolus-Tracking两种触发方法完成扫描;分析评估A、B两组中不同触发方式获得的CTPA图像质量,测量并计算右肺下叶基底动脉及同一层面伴行肺静脉密度的差值.结果 A组采用Test-Bolus法获得的图像质量优于Bolus-Tracking法(F=40.05,P＜0.01),B组采用Bolus-Tracking法获得的图像质量优于Test-Bolus法(F=67.84,P＜0.01).A组中采用Test-Bolus法获得的图像的成像密度差值高于Bolus-Tracking法(t=10.59,P＜0.01),B组中采用Bolus-Tracking法获得的图像的成像密度差值高于Test-Bolus法(t=3.41,P＜0.01).结论 对于小剂量预注射肺动脉监测峰值＜150 HU的患者,采用Bolus-Tracking法触发扫描能增加成像成功率和提高图像质量;而对于监测峰值＞150 HU者,采用Test-Bolus法则能更为合理.%Objective To assess image quality of MSCT pulmonary angiography with Test-Bolus and Bolus-Tracking technique. Methods Totally 568 patients with clinically suspected pulmonary embolism (PE) underwent 64-slice spiral CT angiography. According to the peak enhancement of pulmonary artery, patients were divided into group A (≥150 HU) and group B (<150 HU) after low dose experimental injection test. The image quality of group A and group B were evaluated. The density difference between right inferior pulmonary artery and the same level pulmonary vein was measured and calculated. Results In group A, Test-Bolus was superior to Bolus-Tracking technique (F=40. 05, P<0. 01). In group B, Bolus-Tracking technique was better (F=67. 84, P<0. 01). In group A, the density difference of monitoring imaging with Test-Bolus was higher than that with Bolus-Tracking (t= 10. 59, P<0. 01) , while in group B, the density difference of Bolus-Tracking was higher than that with Test-Bolus (t = 3. 41, P<0. 01). Conclusion After low dose experimental injection test, if the peak enhancement the pulmonary artery was less than 150 HU, using Bolus-Tracking technique may increase success rate of scanning and improve image quality; whereas if the peak enhancement of pulmonary artery was higher than 150 HU, Test-Bolus is a better choice than Bolus-Tracking.