【摘要】 目的　研究含氟碳气体表面活性造影剂低温保存基本特性变化 ,观察其直径大小 /浓度及二维超声回声强度。方法　将造影剂分别在室温、5℃、-5℃及 -2 0℃的条件下保存 ,保存期为 10d ,用CoulterⅡ型颗粒计数仪测定平均直径和浓度。用GELOGIQ 9超声仪二维超声观察其血管内回声强度。结果　在室温条件下造影剂可保存 2 4h ,5℃冷藏条件下能稳定 1～ 2d ,在 -5℃和 -2 0℃的条件下可保存一个月。在 -5℃和 -2 0℃条件下保存 ,第一天造影剂的浓度和二维超声血管内回声强度就开始下降 ,然而在第四天 ,造影剂的浓度及二维血管内回声强度几乎达到冷冻前的水平。结论　造影剂须在低于 -5℃的条件下保存。在融化过程中微气泡的热膨胀足以使微气泡破裂。造影剂在低温条件下保存稳定性仍不理想 ,需进一步研究提高造影剂在融化过程中保持稳定的技术 ,寻找更理想的保存方法更多还原

【Abstract】 Objective The acoustic and physical properties of a perfluorocarbon-filled surfactant ultrasound contrast agent under low temperature storage were studied. This included mean bubble size, concentration and acoustic scatter intensity in two-dimensional imaging.Methods The surfactant contrast agent was stored at 5℃, -5℃ and -20℃, respectively for 10 days. Physical properties including mean bubble size and bubble concentration were analyzed by a Coulter MultisizerⅡ. Acoustic scatter intensity was measured in two-dimensional imaging by a LOGIQ 9 ultrasound system.Results The microbubbles could stay stable for 24 hours at 5℃, 1 to 2 days at -5℃ and nearly one month under -20℃. The concentration and acoustic imaging intensity began to drop from 24 hours. But on the 4th day, the two parameters almost turned up back to the original level before frozen.Conclusion The agent must be kept under -5℃.The thermal expansion of microbubbles during the thawing process seems to disrupt the bubble integrity. The results suggest that the microbubbles is still unstable in freezer storage and the thawing process, the storage technique needs further improvement.更多还原