摘要
【摘要】目的制备一种新型的多功能超声造影剂，体外观察其超声、磁共振（MR）成像效果及增强高强度聚焦超声（high—intensity focused ultrasound，HIFU）消融效果。方法采用双乳化法合成载超顺磁性氧化铁（superparamagnetic iron oxide，SPIO）纳米颗粒的高分子微球（s—PLGA），检测其一般性质。制备体外成像模型，应用超声诊断仪及磁共振扫描仪对不同浓度s—PLGA分别行超声及MR成像。另取新鲜离体牛肝，局部注射s—PLGA后，给予不同HIFU辐照参数，通过计算辐照区凝固性坏死体积评价s—PLGA增强HIFU消融效果。结果制备的s—PLGA呈球形，平均直径为（885．6±133．2）nm。体外超声显像，s—PLGA呈高回声，回声强度随浓度及机械指数减小而降低；磁共振T2WI呈负增强显像。注射s—PLGA后行HIFU辐照，辐照区凝固性坏死体积明显增大（P〈O．05）。结论自制的多功能超声造影剂一载超顺磁性氧化铁高分子微球具备超声、MR双模态复合成像与增效HIFU的功能。
Objective To prepare the multi-functional ultrasound contrast agents, which were investigated for ultrasound （US）/MR dual-mode imaging and high-intensity focused ultrasound（HIFU） synergism in vitro. Methods Double emulsion method was used to prepare the superparamagnetic iron oxide （SPIO）-loaded PLGA microcapsules （s-PLGA）, and its morphology, size, Fe3 04 loading capacity were assessed. Then,the prepared s-PLGA microcapsules with different concentrations were applied to perform ultrasound and MR imaging in vitro. In addition,the degassed bovine liver in vitro was directly injected into 200 t^l s-PLGA in saline （0.5 mg Fe/ml） just before HIFU ablation,the saline （200 μl） and pure PLGA （200μl） were employed for control. After HIFU ablation, the volume of coagulated tissue irradiated by HIFU was calculated. Results The s-PLGA microcapsules were observed with regular spherical morphology and its average size was （885.6 ± 133.2）nm. In vitro, the s-PLGA showed hyperechogenicity in US imaging and MR negatively enhanced effect in T2WI, the volume of coagulated tissue irradiated by HIFU after local injection of s-PLGA was larger than that of saline and pure PLGA （P 〈 0.05）. Conclusions The prepared s-PLGA microcapsules are successfully acted as dual-mode biological imaging contrast agents for ultrasound and MR imaging and HIFU synergism in vitro.
出处
《中华超声影像学杂志》
CSCD
北大核心
2012年第7期625-628,共4页
Chinese Journal of Ultrasonography
基金
基金项目：国家自然科学基金重点项目（81130025）
国家自然科学基金国际（中加）合作与交流项目（81161120548）
973计划（2011CB707905）
关键词
超声检查
微气泡
纳米技术
磁共振成像
超声
高强聚焦
Ultrasonography
Microbubbles
Nanotechnology
Magnetic resonance imaging
Ultrasound, high-intensity focused
