Abstract: This study evaluated whether or not a superabsorbent polymer（SAP） combined with ultrasound contrast agent （UCA） could enhance damage efficacy of high intensity focused ultrasound（HIFU） on Echinococcus granulosus protoscoleces in vitro. Thirty test tubes each with 6 000-7 500 protoscolices were divided into 5 groups： group A （blank control） without HIFU treatment, group B treated with HIFU（50 W）only, group C treated with 10 μl UCA and HIFU, group D treated with 0.01 g SAP and HIFU, group E treated with 10 μl UCA, 0.01g SAP, and HIFU. In group B, echo enhancement of ultrasound image, suspension temperature（26.0 ℃±0.2 ℃） and protoscoleces mortality（30.4%） were higher than that of group A（18.0 ℃±0.1℃, 1.9%）（P<0.01）. Compared with group B, the echo enhancement of ultrasound image, suspension temperature（27.0 ℃±0.2 ℃, 28.2 ℃±0.2 ℃） and protoscoleces mortality（50.0%, 53.7%） of groups C and D increased significantly（P<0.01）. In group E, more protoscoleces were stained in red and their internal structures were indistinct. By chi-square test, the protoscoleces mortality of group E（69.7%） was higher than that of groups C and D （P<0.01）. There was no sinificant difference in suspension temperature among the 3 groups.    

Key words: Superabsorbent polymer, Ultrasound contrast agent, High intensity focused ultrasound （HIFU）, Hydatid, Protoscolex