超声照射对声振微泡稳定性的影响

目的与方法造影剂微泡浓度、大小是影响心肌声学显影最重要因素。本研究采用２×２×４析因分析法分析不同超声照射条件对造影剂微泡浓度及直径的影响,即声波频率、能量以及照射时间对微泡浓度、大小的单独及交互作用。为临床行静脉心肌声学造影检查时选择适宜的超声照射条件提供参考。结果能量越大、照射时间越长,微泡破坏越多,平均直径越小：照射频率对微泡浓度影响不大,但影响微泡大小,频率越高,微泡越小。结论为减少超声照射对微泡的破坏,提高心肌声学造影效果,应尽可能选用低能量、低频率超声波,并减少不必要的照射时间。

Effect of ultrasound exposure on stability of sonicated microbubbles

Objectiveand methods The concentration and the size of contrast microbubbles are both the importantfactors that affect the quality of intravenous myocardial contrast echocardiography(IMCE), but the interactions between microbubbles and ultrasound are poorly understood. Inorder to select optimal ultrasound exposure condition for IMCE, the influences ofultrasound energy, frequency and exposure time on stability of sonicated microbubbles wereevaluated by a 2´ 2´ 4 factorial analysis. Results The concentration ofmicrobubbles was decreased when the ultrasound energy was increased or the duration ofexposure to ultrasound was prolonged (P<0.001). The frequency of ultrasound did notsignificantly influence the concentration of the microbubbles (P=0.061), but influencedthe size of the bubbles. The higher the energy and the frequency or the longer theexposure time, the more the bubbles were destroyed and the smaller the mean size ofcontrast bubbles was (energy, P=0.004; frequency, P<0.001; duration of exposure,P<0.001). Conclusions These findings could lead us to select ultrasound at lowerfrequency, lower ultrasound power and to reduce duration of exposure microbubbles toultrasound for improving effect of contrast in IMCE.