Magnetically-coated silica nanospheres for dual-mode imaging at low ultrasound frequency

AIM: To experimentally investigate the acoustical behavior of different dual-mode nanosized contrast agents(NPCAs) for echographic medical imaging at low ultrasound(US) frequency. METHODS: We synthesized three different nanosized structures:(1) Pure silica nanospheres(SiNSs);(2) FePt-iron oxide(FePt-IO)-coated SiNSs; and(3) IOcoated SiNSs, employing three different diameter of SiNS-core(160, 330 and 660 nm). Tissue mimicking phantoms made of agarose gel solution containing 5 mg of different NPCAs in 2 mL-Eppendorf tubes, were insonified by a commercial echographic system at three different low US pulse values(2.5, 3.5 and 4.5 MHz). The raw radiofrequency signal, backscattered from each considered NPCA containing sample, has been processed in order to calculate the US average backscatter intensity and compare the acoustic behavior of the different NPCA types. RESULTS: The highest US contrast was exhibited by pure SiNSs; FePt-IO-coated SiNSs acoustical behavior followed a similar trend of pure SiNSs with a slight difference in terms of brightness values. The acoustic response of the examined NPCAs resulted function of both SiNS diameter and US frequency. Specifically, higher US frequencies determined higher value of the backscatter for a given SiNS diameter. Frequencydependent enhancement was marked for pure SiNSs and became less remarkable for FePt-IO-coated SiNSs, whereas IO-coated SiNSs resulted almost unaffected by such frequency variations. Pure and FePt-IO-coated SiNSs evidenced an image backscatter increasing with the diameter up to 330 nm. Conversely, among the types of NPCA tested, IO-coated SiNSs showed the lowest acoustical response for each synthesized diameter and employed US frequency, although a diameter-dependent raising trend was evidenced. CONCLUSION: The US characterization of magnetically covered SiNS shows that FePt-IO, rather than IO, was the best magnetic coating for realizing NPCAs suitable for dual mode imaging of deep organs, combining US and magnetic resonance imaging.

双模态超声在评估乳腺癌新辅助化疗疗效中的应用价值

目的分析双模态超声在评估乳腺癌新辅助化疗疗效中的应用价值。方法选取2014年11月-2016年1月就诊于新疆医科大学附属肿瘤医院的单发乳腺癌女性患者42例,在新辅助化疗前、后行常规超声、常规超声联合超声造影检查(即双模态超声),全部化疗周期结束后行手术取得病理结果,采用Miller and Payne病理反应分级标准评估新辅助化疗疗效,将术后病理切片与治疗前活检病理切片相对比,癌细胞减少≤30%定义为无效,癌细胞减少>30%或者无浸润性癌成分定义为有效。结果有效组24例,无效组18例,以病理学评估结果为金标准做一致性检验,得到常规超声的Kappa值为0.507,双模态超声的Kappa值为0.667,差异有统计学意义(P<0.05);新辅助化疗前、后病灶的达峰时间(TTP)、平均增强时间(MTT)差异均无统计学意义(P>0.05),化疗后病灶的峰值强度(PI)和曲线下面积(AUC)均低于化疗前,且差异有统计学意义(P<0.05);有效组与无效组间病灶的峰值强度变化率、曲线下面积变化率差异有统计学意义(P<0.05)。构建ROC曲线,得到最佳诊断界值为0.379,可在最大程度上区分化疗的有效和无效。结论双模态超声可较准确地评估乳腺癌新辅助化疗疗效,同时超声造影参数具有一定的评估疗效的价值。

超声医学专业型硕士研究生培养的探索与实践

医学研究生教育是针对有医学基础知识的医学生的继续教育,随着我国学位制度的改革,“双规合一”新模式应运而生,虽然在新模式的探索中有一定成效,但也存在问题。以科室在读超声医学专业型研究生为研究对象,对科室日常教学及培养经验进行总结与分析,以提高医学生的专业知识、实践操作和临床思维能力为目的,注重培养科研思维,并与医德医风教育相结合,关心医学生身心健康,对全面提高超声医学专业型硕士研究生素质,保证本专业研究生的培养质量有一定的促进意义。

一种靶向蛋白质超声微泡的制备及表征

以氟碳气体为超声造影剂,通过接枝纳米磁性颗粒-RGD多肽,构建靶向蛋白质超声微泡,制备一种可同时用于超声造影和磁共振成像(MRI)的双模态造影增强剂。通过显微镜对磁性蛋白超声微泡形貌进行观察,利用红外光谱、分光光度法分析纳米磁性颗粒接枝牛血清蛋白的接枝率,并通过细胞实验评价磁性蛋白微泡的生物相容性。

Multifunctional lymph-targeted platform based Mn@mSiO2 nanocomposites： Combining PFOB dual-mode imaging and DOX for cancer diagnose treatment on for and

A universal platform with M_n doping and hyaluronic acid （HA） modification, based on mesoporous silica （mSiO2）, was designed and used as a basic multifunctional material with magnetic resonance （MR） imaging. Furthermore, we added flexible functions through the addition of functional molecules. Specially, two typical compounds, hydrophobic perfluorooctyl bromide （PFOB） and hydrophilic doxorubicin （DOX）, were loaded into the channels to obtain PFOB@Mn@mSiO2@HA （PMMH） or DOX@Mn@mSiO2@HA （DMMH） or imaging and therapy, respectively. The were highly targeted to the lymph system in nanoparticles for dual-mode imaging PMMH and DMMH nanoparticles vitro and in vivo. MR and ultrasound imaging of PMMH nanoparticles were performed in the lymph system, while MR imaging and chemotherapy of DMMH nanoparticles was used to detect cancer. These results showed that both PMMH and DMMH nanoparficles can be designed with high lymph targeting efficiency. PMMH nanoparticles are a dual-mode contrast agent for both ultrasound and MR imaging for the lymph system and DMMH nanoparticles are powerful agents for the combined diagnosis and therapy of cancer in vivo.

双模态超声在乳腺癌前哨淋巴结转移风险评估中的应用价值

目的探讨双模态超声(常规彩色多普勒超声联合经皮超声造影)在乳腺癌前哨淋巴结转移风险评估中的应用价值。方法分析62例术后病理诊断为浸润性乳腺癌患者的临床资料,评估常规彩色多普勒超声、经皮超声造影和双模态超声对乳腺癌前哨淋巴结转移风险的诊断价值。结果经皮超声造影检出前哨淋巴结(3.4±0.2)枚,多于常规彩色多普勒超声的(1.7±0.1)枚(P<0.01)。常规彩色多普勒超声诊断前哨淋巴结转移风险的灵敏度为33.33%(3/9),特异度为96.23%(51/53)。经皮超声造影诊断前哨淋巴结转移风险的灵敏度为55.56%(5/9),特异度为92.45%(49/53)。双模态超声诊断前哨淋巴结转移风险的灵敏度为77.78%(7/9),特异度为92.45%(49/53)。结论双模态超声诊断乳腺癌前哨淋巴结转移风险有较高的灵敏度,优于单独常规彩色多普勒超声或经皮超声造影,有望成为术前评估前哨淋巴结转移的有效方法。