液态氟碳纳米脂质微球超声对比剂用于增强正常大鼠CT显像实验研究

Experimental study of lipid perfluorooctylbromide nanoparticles ultrasound contrast agent in enhanced computed tomography of rats

目的探讨液态氟碳(perfluorooctylbromide,PFOB)纳米脂质微球超声对比剂作为CT对比剂对正常大鼠各脏器的增强显像效果。方法采用高压均质技术制备PFOB微球,用光镜观察微球形态、分布,用激光粒度和电位分析仪测定微球大小。分别于注入对比剂前后不同时间点对大鼠进行胸腹部CT扫描,同时监测大鼠生命体征变化。肝脾实质为感兴趣区,测量感兴趣区造影前后CT值,绘制时间-密度曲线(time-density curve,TDC)。结果PFOB微球粒径极小,分布均匀。体内造影表明,作为超声对比剂的PFOB微球也能有效增强大鼠肝、脾及脉管系统的影像密度,造影前后感兴趣区CT值差异有统计学意义(P<0.05)。脾实质较肝实质强化效果更显著,持续显影时间长达8d。实验过程中大鼠生命体征未见明显变化。结论PFOB微球超声对比剂可同时用于CT显像,这一多功能的对比剂将具备良好的应用前景。

Objective To evaluate the enhancement effect of computed tomography （CT） in rats with a lipid perfluorooctylbromide （PFOB） nanoparticles ultrasound contrast agent. Methods Lipid PFOB nanoparticles were prepared by microfluidization technique. The morpholog and distribution were observed with optical microscope. Particle size and electric potential were determined with laser light scattering analyzer. Twelve normal wistar rats were performed directly contrast imaging after injection of PFOB nanoparticles via caudal vein. Vital signs of rats were monitored during the whole study. CT values in region of interest （ROI） were measured and the time-density curve （TDC） was drawn. Results The nanoparticle size and distribution were highly uniformed. PFOB nanoparticles could produce density enhancement of liver, spleen and great vessels after immediate injection. Significant differences of CT values in ROI between pre-contrast and post-contrast were observed （P〈0.05）. Splenic enhancement was more significant and the duration was more than 8 d. No death or abnormal behaviors of rats were observed more than 4 weeks. Conclusion PFOB nanoparticles produce effectively prolonged enhancemend of liver, spleen and great vessels in rats, and can be regarded as a potential multimodality （ultrasound/CT） contrast agent.