Schneider M, Arditi M, Barrau M B, Brochot J, Broillet A, Ventrone R, Yan F
Bracco Research SA, Carouge-Geneva, Switzerland.
Invest Radiol. 1995 Aug;30(8):451-7. doi: 10.1097/00004424-199508000-00001.
The basic characteristics of BR1, a novel echo contrast agent based on stabilized sulfur hexafluoride (SF6) microbubbles have been evaluated.
The authors determined the physicochemical properties (bubble concentration, bubble size distribution, resistance to pressure, and stability) and the acoustic properties (backscatter and attenuation coefficients) of BR1. The diagnostic value of BR1 was evaluated further in minipigs. Left heart images were recorded before and after injection of different doses of BR1.
BR1 is formulated as a lyophilized product, which after addition of saline, provides a suspension containing 2 x 10(8) SF6 microbubbles/mL with a number mean diameter of 2.5 microns. More than 90% of the bubbles are below 8 microns. The use of SF6 rather than air provides an improved resistance to pressure increases such as the ones occuring in the left heart during systole. After reconstitution, the echogenicity and the bubble characteristics are unchanged for more than 8 hours. The high echogenicity remains almost constant over the entire medical frequency range (1-10 MHz). BR1 injections in animals resulted in a homogenous, dose-dependent opacification of the left heart.
Considering its high echogenicity, outstanding stability, and resistance to pressure changes, BR1 is a very promising ultrasound contrast agent.
已对一种基于稳定六氟化硫（SF6）微泡的新型超声造影剂BR1的基本特性进行了评估。
作者测定了BR1的物理化学性质（气泡浓度、气泡大小分布、耐压性和稳定性）以及声学性质（背向散射和衰减系数）。在小型猪中进一步评估了BR1的诊断价值。在注射不同剂量的BR1之前和之后记录左心图像。
BR1制成冻干产品，加入生理盐水后，得到一种悬浮液，其中含有2×10⁸个SF6微泡/毫升，数均直径为2.5微米。超过90%的气泡直径小于8微米。使用SF6而非空气可提高对压力增加的耐受性，比如在收缩期左心出现的压力增加。复溶后，回声性和气泡特性在8小时以上保持不变。在整个医用频率范围（1 - 10兆赫）内，高回声性几乎保持恒定。给动物注射BR1导致左心均匀的、剂量依赖性的显影。
鉴于其高回声性、出色的稳定性和对压力变化的耐受性，BR1是一种非常有前景的超声造影剂。
