超声造影剂对高强度聚集超声治疗兔肝VX2肿瘤的影响

目的探讨高强度聚焦超声（HIFU）联合超声造影剂治疗兔肝VX2肿瘤时，不同剂量的超声造影剂对治疗效应的影响。方法45只荷瘤兔随机分为三组：A组，单纯HIFU辐照组；B组和C组，均为联合辐照组，超声造影剂剂量分别为0．03ml／kg和0．05ml／kg。结果超声造影剂能够增强HIFU治疗效率，且超声造影剂的剂量越高，HIFU治疗效率提高越明显（P〈0．05）。结论超声造影剂可以提高HIFU治疗效率，而且超声造影剂剂量越高则HIFU的治疗效率越高。     

微泡造影剂联合高强度聚焦超声治疗兔肝VX-2肿瘤的声像图监测

目的 探讨微泡造影剂联合高强度聚焦超声治疗兔肝VX-2肿瘤时声像图的变化特征及超声监控能力。 方法 45只荷瘤兔随机分为3组，一组接受单纯高强度聚焦超声治疗，另两组为高强度聚焦超声联合微泡造影剂治疗。 结果 高强度聚焦超声联合微泡造影剂治疗肝肿瘤可以大大缩短治疗时间。各治疗组声像图变化的病理学基础各不相同。联合治疗后10min靶区高回声面积与凝固性坏死面积相关性良好（r=0．986，P〈0．05）。 结论 微泡造影剂增强高强度聚焦超声疗效切实可行，联合治疗的声像图特征性变化能够有效判断治疗效果。     

不同剂量微泡造影剂在高强度聚焦超声消融活体羊肝组织中的增效效应

目的 探讨不同剂量超声造影剂对高强度聚焦超声(HIFU)消融活体羊肝组织的增效效应.方法 南疆黄羊20只,随机分为4组.第1组为HIFU联合0.01 ml/kg SonoVue.第2组为HIFU联合0.03 ml/kg SonoVue,第3组为HIFU联合0.05 ml/kg SonoVue,第4组为单纯HIFU组.麻醉状态下,微泡造影剂于HIFU辐照前静脉团注,20 s后开始HIFU辐照.每组采用定点辐照,所用辐照参数为频率0.8 MHz、声强19 100 W/cm2、辐照深度30 mm、辐照时间15 s.HIFU辐照结束后1周处死动物.观察并测量凝同性坏死大小,对凝固性坏死作组织病理分析.结果 在相同声辐照参数下,1、2、3组凝同性坏死区域均大于第4组,差异有统计学意义(P<0.05),且凝固性坏死体积随SonoVue剂量的增加而逐渐增大,差异有统计学意义(P<0.05).组织病理学检查发现凝同性坏死区内无正常组织残留.除实验3组出现消融灶邻近组织和皮肤损伤外,其余各组均未出现明显并发症.结论 微泡造影剂在HIFU消融过程中的增效效应与微泡造影剂的剂量有关,微泡造影剂的剂量越大,所形成的凝固性坏死的体积越大,增效越明显.     

连续和脉冲高强度聚焦超声辐照兔肝VX2移植瘤的比较

目的 比较连续和脉冲高强度聚焦超声辐照兔肝VX2移植瘤时的治疗效果.方法 将48只荷瘤兔随机分为A、B、C3组,每组各16只.A组(连续波组)用连续高强度聚焦超声辐照,B、C组(脉冲波组)分别用占空比为75％和50％的脉冲高强度聚焦超声(pulsed high intensity focused ultrasound,PHIFU)辐照.结果 3组消融后的肿瘤组织均发生确切的凝固性坏死,且有效地控制肿瘤复发与转移;与连续波组相比,脉冲波组能效因子(energy efficiency factor,EEF)减小,皮肤红斑发生减少(P＜0.05).结论 PHIFU辐照能达到与连续波辐照相同的治疗效果,实际辐照剂量相当,但损伤效率提高,并发症减少.PHIFU有望成为一种安全、有效的肿瘤治疗方式.     

超声造影剂增强HIFU消融作用的病理学研究

目的探讨超声造影剂增强高强度聚焦超声（HIFU）消融生物组织作用的病理学改变。 方法24只新西兰大白兔按体质量配对分为两组，A组肝脏接受单纯HIFU辐照，B组动物接受辐照前经静脉注射超声造影剂SonoVue。辐照后测量组织凝固体积并观察光电镜下组织学及细胞超微结构改变。 结果A组与B组组织凝固体积分别为（0．07±0．02）cm^3和（0．21±0．06）cm^3（P＜0．05）。光镜下两组辐照区肝组织未见凝固性坏死，B组可见部分细胞膜及胞核破坏。电镜下两组辐照区细胞内均未见完整细胞器，均呈现不可逆凝固性坏死，A组辐照区细胞结构较B组清楚。 结论超声造影剂增加HIFU焦域体积并进一步破坏细胞结构，从而增强HIFU消融作用。     

高强度聚焦超声联合超声造影剂消融兔肝后细胞凋亡和增殖细胞核抗原表达的研究

目的：探讨高强度聚焦超声（HIFU）联合超声造影剂消融技术对兔肝组织细胞凋亡和增殖细胞核抗原（PCNA）表达的影响。方法：40只新西兰纯种大白兔分为A、B组，A组兔肝接受HIFU辐照前，经耳缘静脉注射生理盐水；B组接受辐照前注射超声造影剂SonoVue。A、B组均在辐照后5min、1d、3d、7d、14d分别处死4只动物，将肝取出体外观察，取靶区及周围组织（距靶区边缘5mm以内），HE染色观察组织病理学改变，原位末端标记法（TUNEL）检测细胞凋亡，免疫组织化学方法检测细胞PCNA表达。结果：HIFU辐照后3d、7d、14dB组辐照区域边缘纤维包裹带宽度大于A组（P〈0．05）。HIFU辐照后1d、3d、7d、14dB组靶区周围组织（距靶区边缘5mm以内）凋亡细胞数和PCNA阳性细胞指数较A组增高（P〈0．05）。结论：与单纯HIFU相比，HIFU联合超声造影剂促进了消融后坏死区域机化包裹，增加了HIFU靶区周围细胞凋亡，提高了细胞增殖能力，为进一步增强HIFU消融作用提供了实验数据。     

超声造影剂增强HIFU消融兔肝组织的电镜观察

目的探讨高强度聚焦超声(HIFU)联合超声造影剂消融后兔肝细胞超微结构变化。方法30只动物分为两组,A组单纯HIFU辐照,B组辐照前注射超声造影剂。辐照后1h、6d、14d电镜观察。结果辐照后两组靶区细胞坏死,辐照后早期A组靶区可见细胞轮廓。辐照后6d两组靶区细胞崩解,边缘见纤维包裹带,靶区周围细胞浊肿,B组较A组严重,B组靶区周围凋亡小体多于A组。结论超声造影剂增强HIFU消融作用,进一步破坏组织超微结构。     

亚微米造影剂在高强度聚焦超声消融兔VX2乳腺肿瘤中的应用研究

目的 在高强度聚焦超声(HIFU)消融兔VX2乳腺肿瘤的过程中加入亚微米造影剂,探讨其对辐照效果的影响.方法 制备亚微米造影剂,检测微泡性质.VX2乳腺肿瘤兔随机分组,在不同辐照剂量(150W、120W)和不同辐照时间(5s、3 s)条件下,记录HIFU辐照前后灰阶变化,辐照后行病理检查.结果 成功制备亚微米造影剂.HIFU+亚微米造影剂组较HIFU+ PBS组能够有效提高HIFU的损伤面积,减少辐照强度,缩短辐照时间.结论 亚微米造影剂不仅在诊断方面有特殊的应用价值,在超声治疗领域也有很好的应用前景.     

低强度聚焦超声联合载药微泡靶向治疗兔VX2肿瘤的实验研究

目的 探讨自制低强度聚焦超声(low intensity focused ultrasound,LIFU)定位辐照载紫杉醇脂质微泡(pclitaxel-carryingliposome microbubble,PLM)靶向治疗兔VX2肿瘤的治疗效果.方法 建立兔VX2肿瘤模型,20只荷瘤兔随机分为生理盐水对照组、单纯PLM组、非聚焦超声+PLM组、聚焦超声+PLM组.各组治疗前后均行超声检查观察肿瘤生长变化情况,比较各组肿瘤的抑瘤率.末次治疗结束后剥取肿瘤组织,TUNEL法检测细胞凋亡并进行半定量分析.结果 聚焦超声+PLM组肿瘤体积增长最慢(P＜0.05),抑瘤率、细胞凋亡指数明显高于其他各组(P＜0.05),VX2肿瘤的抑制作用最显著.结论 低强度聚焦超声联合PLM能有效介导药物定位释放,进一步提高药物靶向性,有望成为专门化的用于药物体内定位控释的超声辐照系统.     

脉冲高强度聚焦超声联合微泡非热损伤兔肝VX2移植瘤的病理观察

目的探讨脉冲高强度聚焦超声(HIFU)联合微泡非热损伤兔肝VX2移植瘤的病理变化。方法将36只荷瘤兔随机分为假照组、P-HIFU组和P-HIFU UCA组进行HIFU辐照,观察辐照后组织的病理学变化。结果假照组、P-HIFU组和P-HIFU UCA组TTC染色后,肉眼下各组肿瘤组织被均匀红染,而组织学检查显示P-HIFU组和P-HIFU UCA组肿瘤细胞有损伤征象,胞浆内有大小不等空泡。结论脉冲高强度聚焦超声(HIFU)以及联合微泡均可对兔肝VX2移植瘤通过非热损伤达到治疗目的。     

高强度聚焦超声治疗恶性骨肿瘤的实验研究

目的 探讨高强度聚焦超声（HIFU）治疗恶性骨肿瘤的可行性。方法 12只VX2移植性骨肿瘤兔接受HIFU治疗,采用超声检查、组织病理学方法观察HIFU治疗后移植性骨肿瘤的变化。结果 HIFU治疗后骨内、外肿瘤组织的回声增强,肿瘤组织凝固性坏死。结论 HIFU治疗兔移植性VX2骨肿瘤是可行的。     

高强度聚焦超声联合微泡损伤山羊肝的增效性研究

目的 探讨超声造影剂SonoVue用于增强高强度聚焦超声(HIFU)损伤山羊肝组织的可行性.方法 南江黄羊15只,采用自身对照,分为HIFU治疗组(对照组)和HIFU联合造影剂治疗组(实验组).治疗深度30 mm,分别在声功率为150 W、250 W、350 W条件下对肝定点辐照15 S.辐照后24 h处死动物,解剖观察凝固性坏死情况,并作病理切片分析.结果 在相同声辐照参数下,实验组凝固性坏死发生率及凝固性坏死区域长、宽、厚、体积均明显大于对照组(P＜0.05),随功率增加实验组凝固性坏死体积增加幅度较对照组更明显,实验组能效因子(EEF)明显小于对照组.凝固性坏死区与正常肝组织分界清楚,且病理切片显示损伤为不可逆性,分界处可见大量空泡.结论 HIFU联合微泡造影剂能在山羊肝中形成完全的凝固性坏死,同时提高凝固性坏死的损伤率,增大凝固性坏死体积,提高HIFU治疗效率.     

高能聚焦超声治疗兔VX2肝癌后磁共振灌注加权成像特征初探

目的：探讨兔VX2肝癌经高能聚焦超声（HIFU）治疗后的磁共振灌注加权成像（PWI）的基本成像特点。方法：新西兰大白兔20只,采用组织块种植的方法制成20只兔VX2肝癌模型,使用1.5T MR扫描仪行常规扫描后,采用EPI-SE序列、SENSE技术,于治疗前、后14d对肿瘤行PWI,选取病灶与周围正常肝组织的感兴趣区（ROI）,分别测量血流灌注值,进行统计学分析。PWI采用信号强度-时间曲线的最大信号下降斜率（SRSmax）作为定量指标,分析不同ROI的SRSmax变化规律。结果：治疗前、后兔肝VX2瘤中央区及周边区之间的SRSmax的差异有统计学意义（P＜0.05）;瘤旁肝实质之间的SRSmax的差异无统计学意义（P＞0.05）。结论：利用1.5T MR扫描仪进行兔肝VX2瘤灌注成像研究是可行的,PWI可用于评价HIFU治疗后肝脏肿瘤的血管生成、破坏状况;不同ROI的SRSmax变化程度及规律也不同,其PWI表现与肿瘤的坏死程度、范围基本相符。     

Characterization of extracorporeal ablation of normal and tumor-bearing liver tissue by high intensity focused ultrasound

Treatment parameters of extracorporeal high intensity focused ultrasound (HIFU) were analysed in normal and tumor-bearing rabbit liver. HIFU was generated with a 1 MHz transducer and energy was provided by a 7.5 kW power amplifier. In vivo experiments were conducted on 74 New Zealand rabbits. Normal rabbits and rabbits bearing an intrahepatic VX2 tumor were used. In group 1, spatial peak temporal peak (SPTP) intensities ranging from 1470 to 5500 W cm⁻² and exposure times from 0.5 to 5 s were tested at a constant depth in the liver; in group 2, the output power was adjusted as a function of the target depth in order to keep constant the focal in situ intensity in the liver; in group 3 (liver tumors), the focal in situ intensity was 1365 W cm⁻² in eight rabbits and 500 W cm⁻² in nine. In groups 1, 2 and 3, rabbits were sacrificed 48 h after the treatment. Groups 4 and 5 were designated for analysis of the lesion in the normal liver 4 weeks after treatment at 1000 W cm⁻² and 3000 W cm⁻² SPTP intensities, respectively. In normal rabbits, the lesion volume increased with exposure time at constant intensity; there was a negative correlation between intensity and exposure time (group 1). When the output power was adjusted as a function of the path length, the lesion size was nearly constant (group 2). In VX2 rabbits, tumor destruction rates were significantly higher in rabbits treated at 500 W cm⁻² than in rabbits treated at 1365 W cm⁻² (p < 0.05; group 3). As in the normal liver, the lesion volume increased with the exposure time at constant intensity. HIFU lesions treated at 1000 W cm⁻² (SPTP) healed as thin fibrous scars, and no severe complication occurred (group 4); at 3000 W cm⁻² (SPTP), scars were larger and perforation of a neighboring organ was seen in 7 of 11 rabbits (group 5).     

Transmission electron microscopy of rabbit liver after high-intensity focused ultrasound ablation combined with ultrasound contrast agents

The purpose of this study was to observe sequential changes in rabbit liver under transmission electron microscopy after high-intensity focused ultrasound (HIFU) ablation. Thirty rabbits were randomly divided into 2 groups. The livers of rabbits in group A underwent single HIFU ablation; those in group B were given the ultrasound contrast agent Sonovue 0.2 mL/kg before HIFU exposure. Five rabbits from each of the 2 groups were killed at 0 h, 6 d, and 14 d after HIFU ablation. Tissue samples that included targeted and untargeted tissues were observed under transmission electron microscopy. Electron microscopy showed that most of the cell organs in targeted areas of groups A and B disappeared early after HIFU, but the basic cell structure was seen in group A. On the sixth day after HIFU ablation in the 2 groups, all cells in the targeted areas were disrupted and fibrous bands were detected in the rims of targeted areas. In surrounding areas, cell swelling in group B was more severe than in group A, and a greater number of apoptotic bodies were found in group B. The use of an ultrasound contrast agent can enhance the effects of HIFU ablation on the destruction of cell ultrastructure and can enlarge the region of HIFU ablation; this provides experimental evidence for control of HIFU effects.     

低能量脉冲式超声联合微泡对兔VX2肿瘤微循环的阻断作用

目的探讨低能量脉冲式超声联合微泡对兔VX2肿瘤微循环的阻断作用及其病理机制。方法将36只皮下VX2荷瘤兔随机平均分成3组:超声微泡组注入0.2ml/kg体质量微泡5ml,并辅以超声辐照10min;单纯超声组注入生理盐水5ml,辐照10min;单纯微泡组仅注入0.2ml/kg体质量微泡5ml,不进行超声辐照。CEUS观察各组治疗前、治疗后0、30min、60min时血流灌注情况,比较各时间点的灌注面积。治疗后即刻随机选取各组6只荷瘤兔处死,完整切取肿瘤,行病理学检查。结果超声微泡组治疗后即刻肿瘤血流灌注完全消失,灌注面积为0,但30min及60min后灌注有所恢复,各时间点治疗后灌注面积显著大于治疗前(均P<0.05);大体病理检查见肿瘤微血管扩张、管壁结构崩解,弥漫性充血、出血和肿瘤组织水肿,局部血肿,形成血栓等。单纯超声组及单纯微泡组治疗前、后造影剂灌注面积无差异,肿瘤内部未见出血、水肿等。结论低能量超声联合微泡能够阻断肿瘤微循环,可能是由于空化效应导致血管壁损伤,组织水肿对局部肿瘤血液循环产生阻力,从而阻断肿瘤血液循环。     

Transmission electron microscopy of VX2 liver tumors after high-intensity focused ultrasound ablation enhanced with SonoVue®

Introduction

The purpose of this study was to observe sequential changes in rabbit VX2 liver tumors using transmission electron microscopy after high-intensity focused ultrasound (HIFU) ablation enhanced with the contrast agent SonoVuer® (Bracco, Milan, Italy).

Methods

Thirty New Zealand rabbits with VX2 liver tumors were randomly divided into two groups. The liver tumors of rabbits in Group A underwent single HIFU ablation; those in Group B were given the ultrasound contrast agent SonoVue 0.2 mL/kg before HIFU exposure. Five rabbits from each of the two groups were killed at 0 hours, 6 days, and 14 days after HIFU ablation. Tissue samples that included targeted and untargeted tissue were observed using transmission electron microscopy.

Results

Using transmission electron microscopy, it was evident that most of the cellular organs in the targeted areas of tumors in Groups A and B had disappeared early after HIFU, but the basic cell structure was seen in Group A. On the sixth day after HIFU ablation, all cells in the targeted areas were disrupted, and fibrous bands were detected in the rims of targeted areas in both groups. In the surrounding areas, cell swelling in Group B was more severe than in Group A, and a greater number of apoptotic bodies were found in Group B.

Conclusion

The use of an ultrasound contrast agent can enhance the effects of HIFU ablation on the destruction of cell ultrastructure and can enlarge the region of HIFU ablation; this provides experimental evidence for the use of contrast agents in controlling the effects of HIFU.