CAJ | 학술논문

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,sPLGA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＜0.05).结论自制的多功能超声造影剂-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.
목적 제비일충신형적다공능초성조영제,체외관찰기초성、자공진(MR)성상효과급증강고강도취초초성(high-intensity focused ultrasound,HIFU)소융효과.방법 채용쌍유화법합성재초순자성양화철(superparamagnetic iron oxide,SPIO)납미과립적고분자미구(s-PLGA),검측기일반성질.제비체외성상모형,응용초성진단의급자공진소묘의대불동농도s-PLGA분별행초성급MR성상.령취신선리체우간,국부주사s-PLGA후,급여불동HIFU복조삼수,통과계산복조구응고성배사체적평개s-PLGA증강HIFU소융효과.결과 제비적s-PLGA정구형,평균직경위(885.6±133.2)nm.체외초성현상,sPLGA정고회성,회성강도수농도급궤계지수감소이강저；자공진T2WI정부증강현상.주사s-PLGA후행HIFU복조,복조구응고성배사체적명현증대(P＜0.05).결론 자제적다공능초성조영제-재초순자성양화철고분자미구구비초성、MR쌍모태복합성상여증효HIFU적공능.
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,Fe3O4 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 μl s-PLGA in saline(0.5 mg Fe/ml)just before HIFU ablation,the saline(200 μl)and pure PLGA (200 μl)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 effeet 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.