目的:用声学定量方法探讨正常肝脏高机械指数造影成像时触发间隔与增强效果间关系。方法:10例正常人接受肝脏谐波声学造影,造影剂经前臂浅静脉注射,剂量为0.3ml,触发间隔设1.0s、2.0s、3.0s、4.0s 4个档次。选择经腹主动脉长轴的肝左叶纵切面作为观察切面。造影增强后图像灰阶变化用时间-强度曲线法进行定量分析,测量指标有峰值强度(PI)、曲线下面积(AUC)、峰值强度降半时间(HT)、平均渡换时间(MTT)。结果:各触发间隔肝实质时间-强度曲线形态基本相似,呈单峰形态,近似三角形,可分为上升段、高峰段和下降段。触发间隔从1.0~3.0s时,PI、AUC、HT、MTT测值均逐渐增大,肝实质显影效果逐渐增强;当触发间隔为4.0s时,肝实质显影效果不再更强,PI、AUC、HT、MTT测值与3s时相近,无显著性差异。结论:触发间隔对增强效果有直接影响,在一定范围内可随触发间隔延长而增强,超过此范围,造影效果不会更强。
Abstract
Objective: To have a acoustic densitometry(AD) analysis about the relationship between trigger intervals and effects in experimenting normal liver with high mechanical index(HMI) contrast imaging. Methods?押 Ten cases of normal liver were examined with HMI contrast imaging and the contrast agents were administrated through forearm veins at 0.3ml, trigger intervals being set at 1.0s, 2.0s, 3.0s, 4.0s respectively. The grey scale changes of imaging enhanced by contrast agents were analyzed with time-intensity cure method. The values of peak intensity(PI), area under curve(AUC), half time of descending(HT), mean transit time(MTT) were measured. Results: The time-intensity curves were almost similar at every trigger intervals, with a single-peak-shaped, looking like “a triangle”, which could be divided ascending, peak and descendent periods. but its amplitudes were different. The values of PI, AUC, HT, MTT and the effects of enhancement were gradually increased following trigger intervals increase from 1.0s to 3.0s. The values of PI, AUC, HT, MTT and the effects of enhancement were not increased any more at intervals of 4.0s and the values of PI, AUC, HT, MTT were almost similar with that measured at an interval of 3.0s, with no significant difference. Conclusion: The effects of enhancement in HMI contrast imaging can be directly influenced by trigger intervals. Following the trigger intervals increase, the effects can become stronger. But if the trigger intervals were too long, the effects increased no more.
关键词
肝 /
超声检查 /
多普勒 /
彩色
Key words
liver /
ultrasonography /
Doppler /
color
