Seidel G, Beller K D, Kaps M
Neurologische Universitätsklinik, Lübeck, Germany.
J Neuroimaging. 1998 Jul;8(3):164-8. doi: 10.1111/jon199883164.
Ultrasound contrast agents change the acoustic properties of brain tissue. This can be quantified with acoustic densitometry. In a dog model, the authors examined changes in acoustic impedance in the thalamic and parietal white-matter regions of the brain after intravenous injection of the spherosome containing an ultrasound contrast agent (BY963) filled with perfluoropentane gas. The authors examined six sedated mongrel dogs with a Hewlett-Packard Sonos 1500 device. BY963 filled with perfluoropentane (0.2 ml/kg body weight) was injected three times with a time interval between injections of 5 minutes. Time-dependent changes in mean acoustic impedance were calculated. The authors found a significant increase in peak acoustic impedance after fractional injection of 0.6 ml/kg body weight (3 x 0.2 ml/kg body weight) in the thalamus region up to 7.0 IU (p = 0.006). In the parietal white matter the increase in peak acoustic impedance was not significant (p = 0.06). Statistical comparison of the increase in peak acoustic impedance between placebo and BY963 injection in the thalamus region showed a significant difference after the first injection (p = 0.01) but showed no significance after the second and third injections. The authors concluded that thalamus and parietal white matter of the brain showed different accumulations of BY963.
超声造影剂可改变脑组织的声学特性。这可以通过声学密度测定法进行量化。在一个犬类模型中，作者们研究了静脉注射含有填充全氟戊烷气体的超声造影剂（BY963）的脂质体后，大脑丘脑和顶叶白质区域的声阻抗变化。作者们使用惠普Sonos 1500设备检查了六只镇静的杂种犬。将填充全氟戊烷的BY963（0.2毫升/千克体重）分三次注射，每次注射间隔5分钟。计算平均声阻抗随时间的变化。作者们发现，在丘脑区域注射0.6毫升/千克体重（3×0.2毫升/千克体重）后，峰值声阻抗显著增加，最高可达7.0 IU（p = 0.006）。在顶叶白质中，峰值声阻抗的增加不显著（p = 0.06）。丘脑区域安慰剂注射和BY963注射后峰值声阻抗增加的统计比较显示，第一次注射后有显著差异（p = 0.01），但第二次和第三次注射后无显著差异。作者们得出结论，大脑的丘脑和顶叶白质对BY963的蓄积情况不同。
