目的建立一种用于高强度聚焦超声(HIFU)聚焦性能评价的仿组织透明体模。方法仿组织透明体模主要由聚丙烯酰胺和作为温度敏感指示剂的蛋清混合而成。在B超的监控下使用声功率160W的HIFU在不同的辐照时间下定点辐照体模和新鲜离体牛肝脏,肉眼观察HIFU在体模和新鲜离体牛肝脏中形成的生物学焦域(BFR)形态并测量BFR的长短轴。结果可用肉眼观察HIFU在仿组织透明体模中产生的BFR,其形态呈椭球体,实时超声监控为强回声,BFR的长、短轴随辐照时间的增加而增大。但在相同的辐照参数下,HIFU在仿组织透明体模中产生的BFR的长、短轴小于HIFU在新鲜离体牛肝脏中形成的BFR的长、短轴。结论该仿组织透明体模在用于HIFU聚焦性能的评价方面展示出良好的前景。
Objective To develop an optically transparent tissue-mimicking phantom for the use of evaluating the focusing performance of high intensity focused ultrasound (HIFU). Methods The tissue-mimicking phantom was composed mainly of polyaerylamide gel and egg white as a temperature-sensitive indicator. BFR were produced in the phantom arid degassed in vitro ox liver by real time ultrasound (US) imaging guided HIFU exposure. Acoustic power used was 160 W and HIFU exposure duration was 5, 7, 10 and 20 s in this experiment. The configuration of BFR induced in the phantom and degassed in vitro ox liver was observed, and the length and width of the BFR were measured. Results The formation of BFR induced in the phantom during and after HIFU could be seen by naked eye. The configuration of the BFR was ellipsoid and the eorre sponding US imaging was hypereehoie. The length and width of the BFR increased with the increase of the HIFU exposure duration. But at same exposure parameters, the length and width of BFR induced in the phantom was less than that in degassed ox liver. Conclusion This optically transparent tissue-mimicking phantom can be used for the evaluating HIFU focusing performance.