双源CT双能量肺血管成像中小剂量团注试验法与自动跟踪触发技术的比较

Differences between test bolus(TB) and bolus tracking(BT) techniques for the determination of enhanced quality in pneumoangiogram imaging with dual-source dual-energy computer tomography

目的探讨小剂量团注试验法(test bolus,TB)和自动跟踪触发(bolus tracking,BT)技术在双源CT双能量肺血管成像中成像质量有无区别。方法选取我院疑诊肺动脉栓塞患者50例,按扫描延迟时间随机分为TB组和BT组,每组25例。TB组预先以5ml/s的速率静脉团注20ml碘普罗胺(370mgI/ml),紧跟着以相同速率团注20ml生理盐水,用Dynamic软件测试造影剂达到峰值的时间,然后按测试值进行延迟。BT组动态监测肺动脉干,触发阈值设为100Hu。所有患者均以5ml/s的速率静脉团注70ml碘普罗胺(370mgI/ml),跟以相同速率团注20ml生理盐水。将采集数据传至工作站,由两名影像副主任医师对肺循环不同部位(肺动脉干、左肺动脉主干、右肺动脉主干、肺实质)的增强CT图像质量进行评价。结果两种方法肺循环不同部位的影像质量差异均无统计学意义(P>0.05)。TB法和BT法在扫描延迟时间上差异无统计学意义(P>0.05)。结论双源CT双能量肺血管成像采用TB法和BT法均能取得满意的CT图像。

Objective To discuss the differences between test bolus（TB） and bolus tracking（BT） techniques for the determination of enhanced quality in pneumoangiogram imaging with dual-source dual-energy computer tomography.Methods 50 consecutive patients referred for CTA for exclusion of pulmonary embolism were randomized either into a TB group or into a BT group,and 25 cases in each group.During the pneumoangiogram imaging with dual-source dual-energy computer tomography,different scan delay were applied in each group： Group of TB： 20 ml iopromide（370mgI/ml）with a rate of 5 ml/s were intravenous injected with a rate of 4 ml/s,followed by injection of a saline bolus of 20 ml using the same flow rate.Dynamic software was applied to test the time to peak of contrast media and the scan delay was determined accordingly.Group of BT： The dynamic changes of CT values of pulmonary trunk were observed,and the triggering threshold was preset at 100Hu.70 ml iopromide（370mgI/ml）with a rate of 5 ml/s were intravenous injected with a rate of 4 ml/s,followed by injection of a saline bolus of 20 ml using the same flow rate.The score of all reconstructed CT images of（different vascular segments（pulmonary arteries,pulmonary parenchyma,aorta,all 4 heart chambers） were given by two double blind associate chief physicians of the imaging department.Results There were no difference in the images quality and the vascular strengthening（P0.05）.And there were not difference in the scan delay（P0.05）.Conclusion No significant differences between TB and BT techniques for the determination of enhanced quality in pneumoangiogram imaging with dual-source dual-energy computer tomography.