超声造影早期评价HIFU治疗兔移植性骨肿瘤的初步研究

目的:观察兔VX2移植性骨肿瘤经高强度聚焦超声(High Intensity Focused Ultrasound,HIFU)治疗前后超声造影的图像变化,以评价高强度聚焦超声治疗骨肿瘤的疗效。方法:将VX2瘤块植入20只兔的右侧胫骨髓腔内,三周后进行HIFU治疗。治疗前后均推注超声微泡造影剂,对肿瘤治疗前后的超声造影图像进行比较。结果:治疗前超声造影显示,右侧胫骨髓内肿瘤快速、明显强化,与周边组织分界清楚,测得病灶平均大小为,上下径(17.614±0.955)mm,前后径(10.414±1.142)mm。治疗后造影,治疗区域显示为造影剂灌注缺损区,平均范围为上下径(8.010±0.584)mm,前后径(7.540±0.499)mm,未经治疗的肿瘤组织仍有超声造影剂灌注。结论:超声造影成像清楚地显示肿瘤范围以及治疗后灌注缺损区的大小,通过反映治疗后肿瘤的血供改变来评价HIFU治疗肿瘤的疗效。     

高强度聚焦超声治疗裸鼠胰腺癌皮下移植瘤的初步研究

目的：观察高强度聚焦超声（HIFU）治疗裸鼠胰腺癌皮下移植瘤后的超声回声及病理变化。方法：36只裸鼠在皮下接种SW1990人胰腺癌细胞,随机分成三组,HIFU组18只,假照组9只,对照组9只。治疗中记录肿瘤的回声变化,治疗后每隔四天采用超声观察肿瘤的大小及回声变化,共随访4周。HIFU治疗后于靶区取样进行光镜和电镜检查。结果：HIFU治疗2周后,HIFU组肿瘤体积都有缩小,而假照组和对照组肿瘤继续生长。镜下可见HIFU组靶区内肿瘤组织完全凝固性坏死。结论：HIFU能够有效治疗裸鼠胰腺癌皮下移植瘤,可望成为治疗晚期胰腺癌的有效方法。     

HIFU治疗裸鼠皮下移植瘤超声和磁共振变化的初步观察

目的初步探讨高强度聚焦超声对裸鼠卵巢癌皮下移植瘤治疗前后的超声和磁共振变化.方法HIFU治疗裸鼠卵巢癌模型12例,高强度聚焦超声治疗肿瘤外侧1/2,治疗前后进行超声和磁共振检查.结果(1)治疗前肿瘤组织超声表现为低回声,彩色和能量多普勒检测肿瘤内部及周边均有少许血流信号;治疗后肿瘤组织回声增强,彩色和能量多普勒检测肿瘤治疗区域内部及周边均无血流信号.(2)磁共振检查治疗区域肿瘤组织增强后未见明显强化.结论HIFU能准确破坏卵巢肿瘤,治疗过程中超声定位准确、方便,治疗后磁共振有助于评价其疗效,为临床应用提供实验依据.     

高强度聚焦超声损伤兔肌肉组织的超声影像学变化的初步研究

探讨高强度聚焦超声损伤兔肌肉组织的超声图像变化。采用高强度聚焦超声经皮照射20只新西兰大白兔双侧后肢肌肉,其中18只于照射前1d、照射后10min、照射后1d,3d,7d,14d,21d,28d进行二维超声、彩色多普勒和能量多普勒超声检查,并于照射后28天处死后测量凝固灶大小。另2只分别于照射后1d及照射后50d解剖,行病理学检查。(1)HIFU照射后凝固灶外周可见强回声带至低回声带的演变过程。(2)HIFU照射后第1d,测量的凝固灶体积最大(1476.59±308.64mm3),第3d～第21d,凝固灶体积逐渐缩小(612.47±127.98mm3)。第28d凝固灶体积最小(343.29±54.79mm3)。超声检查在兔肌肉组织HIFU照射后的随访中发挥了重要的作用,为监测HIFU治疗人体软组织肿瘤超声图像的变化提供了实验依据。     

高强度聚焦超声联合全氟戊烷液滴在乳腺癌治疗增效中的实验研究

目的:探讨高强度聚焦超声(High-Intensity Focused Ultrasound,HIFU)联合全氟戊烷液滴(Perfluoropentane droplets,PFP),对小鼠乳腺癌4T1细胞治疗的增效作用。方法:制备PFP,检测其平均粒径及形态结构。试验设立三组:HIFU假照组,单纯HIFU治疗组,HIFU联合PFP治疗组。流式细胞仪检测HIFU分组治疗乳腺癌细胞后细胞存活率及死亡率;体内动物试验分组处理后,二维超声观察HIFU辐照前后肿瘤回声灰度变化情况,超声造影剂灌注缺损面积占总面积百分比评价不同治疗方式对裸鼠皮下移植瘤的消融能力。结果:所制备的PFP平均粒径为1.2μm,形态呈规则球形。细胞试验显示,HIFU联合PFP治疗组乳腺癌细胞死亡率(23.50±1.34)%显著高于单纯HIFU治疗组(14.34±0.55)%和HIFU假照组(11.76±0.62)%(P<0.05);动物试验显示HIFU联合PFP治疗组肿瘤消融面积占总面积百分比(84.03±4.47)%显著高于单纯HIFU治疗组(41.23±4.24)%(P<0.05),HIFU假照组无明显灌注缺损区域。结论:HIFU联合PFP可显著增强对乳腺癌细胞及组织的消融能力。     

双频高强度聚焦超声换能器应用研究进展

高强度聚焦超声(High Intensity Focused Ultrasound,HIFU)消融实体肿瘤已在临床治疗中展示出良好的应用前景。HIFU消融肿瘤技术由于其使靶区肿瘤组织瞬时升温至60℃以上,产生不可逆性凝固性坏死,同时不影响靶区外正常组织而被广泛应用。目前治疗用超声主要使用单频率高强度聚焦超声,但其临床应用的主要限制是靶区组织消融时间较长,靶区外正常组织损伤风险较大。缩短靶区组织消融时间,对于提高HIFU治疗效率,更好地应用于临床较为关键。在总结HIFU换能器的特性和影响HIFU治疗因素的基础上,综述了应用不同类型的双频HIFU换能器强空化和缩短靶区组织消融时间等方面的研究进展。     

高强度聚焦超声作用下体模组织温度上升研究

为研究高强度聚焦超声(HIFU)作用下组织温度上升规律,建立了高强度聚焦声场和组织温度场有限元仿真模型,并通过体外辐照实验对仿真模型进行了验证。通过仿真对水和组织域中的聚焦声场进行建模,计算吸收声能并将其用作热源以计算组织内的温升。进一步制备仿生物组织凝胶体模,利用热电偶进行HIFU作用下体模组织焦点处的测温。结果表明:该模型可有效预测HIFU治疗时的温度上升,与实验所得温度误差不超过 3℃;体模组织受到超声辐照时温度会立即升高,起初温升速率较快,随着辐照时间延长,温升速率逐渐降低,停止辐照后温度立即下降。     

超声造影在兔VX2肝肿瘤模型的早期检测中的应用价值

目的:研究兔VX2早期肝癌常规超声与低机械指数超声造影的图像特点,对比探讨两者在早期肝癌诊断方面的应用价值。方法:25只新西兰大白兔开腹种植VX2肿瘤,造模后14天分别行常规彩色多普勒超声检查及经耳缘静脉注射声诺维实时超声造影检查,观察记录图像二维特征及血供情况,进行对比研究。结果:在24例25个病灶中,常规超声检出23个病灶,病灶大小(0.92±0.15)cm,5个病灶边界显示清晰,18个病灶与周边分界不清;彩色多普勒检出17个结节有不同程度的血流信号,超声造影检出25个病灶,病灶大小(1.13±0.24)cm,25个病灶与周边分界显示清楚,10个病灶内部出现坏死。结论:超声造影较常规超声能更敏感地检出早期肝癌病灶,显示病灶内部坏死区域,病灶周边的浸润范围以及病灶内部血供情况。     

强聚焦换能器冲击波数值模型

0引言高强度聚焦超声(HIFU)技术作为新兴的非侵入式治疗肿瘤方法得到人们极大的关注[1-2]。非线性声场分布是HIFU治疗中的关键物理参数之一,其对准确的预测和评价治疗效果有着重要的作用。Kamakura等人推导了球壳式大张角换能器在椭球坐标系下的非线性方程(spheroidal beam equation,SBE)[3]。通常,将时域波形进行傅里叶级数展开,然后在频域计算SBE模型,得到声场分布。当声功     

鸡贫血病毒VP3基因对荷C6胶质瘤Weister大鼠的治疗

构建荷C6胶质瘤Weister大鼠的肿瘤模型,随机分组给予不同的处理给药,观察治疗期间及治疗后的肿瘤生长情况,通过病理组织学、超微结构分析,检测鸡贫血病毒VP3基因核酸疫苗在Weister大鼠体内的抗肿瘤作用。结果表明,pVVP3治疗组肿瘤生长速度明显受到抑制,其抑瘤率达85．57％。病理组织学观察可见化疗对照组肝组织有点状坏死,而pVVP3治疗组肝组织未见明显病变。肿瘤组织超微结构观察在pVVP3治疗组可见典型的凋亡特征。说明鸡贫血病毒VP3基因核酸疫苗对Weister大鼠C6胶质瘤生长有抑制作用,可诱导肿瘤细胞凋亡,且对肝组织无明显损伤。     

The role of numerical simulation for the development of an advanced HIFU system

High-intensity focused ultrasound (HIFU) has been used clinically and is under clinical trials to treat various diseases. An advanced HIFU system employs ultrasound techniques for guidance during HIFU treatment instead of magnetic resonance imaging in current HIFU systems. A HIFU beam imaging for monitoring the HIFU beam and a localized motion imaging for treatment validation of tissue are introduced briefly as the real-time ultrasound monitoring techniques. Numerical simulations have a great impact on the development of real-time ultrasound monitoring as well as the improvement of the safety and efficacy of treatment in advanced HIFU systems. A HIFU simulator was developed to reproduce ultrasound propagation through the body in consideration of the elasticity of tissue, and was validated by comparison with in vitro experiments in which the ultrasound emitted from the phased-array transducer propagates through the acrylic plate acting as a bone phantom. As the result, the defocus and distortion of the ultrasound propagating through the acrylic plate in the simulation quantitatively agree with that in the experimental results. Therefore, the HIFU simulator accurately reproduces the ultrasound propagation through the medium whose shape and physical properties are well known. In addition, it is experimentally confirmed that simulation-assisted focus control of the phased-array transducer enables efficient assignment of the focus to the target. Simulation-assisted focus control can contribute to design of transducers and treatment planning.     

Pulsed high-intensity focused ultrasound enhances the relative permeability of the blood-tumor barrier in a glioma-bearing rat model

The use of pulsed high-intensity focused ultrasound (HIFU) with an ultrasound contrast agent (UCA) has been shown to disrupt the blood-brain barrier (BBB) noninvasively and reversibly in the targeted regions. This study evaluated the relative permeability of the blood-tumor barrier (BTB) after sonication by pulsed HIFU. Entry into the brain of chemotherapeutic agents is impeded by the BBB even though the permeability of this barrier may be partially reduced in the presence of a brain tumor. F98 glioma-bearing rats were injected intravenously with Evans blue (EB) with or without BTB disruption induced by pulsed HIFU. Sonication was applied at an ultrasound frequency of 1 MHz with a 5% duty cycle, and a repetition frequency of 1 Hz. The accumulation of EB in brain tumor and the tumor-to-contralateral brain ratio of EB were highest after pulsed HIFU exposure. Sonication followed by EB injection showed a tumor-to-contralateral brain ratio in the target tumors which was about 2 times that of the control tumors. This research demonstrates that pulsed HIFU enhances the relative permeability of the BTB in glioma- bearing rats. The results of this pilot study support the idea that further evaluation of other treatment strategies, such as HIFU exposure in addition to combined chemotherapy or repeated pulsed HIFU exposure to increase delivery of drugs into brain tumors, might be useful.     

用于肿瘤治疗的高强度聚焦超声换能器及其温度场测量

高强度聚焦超声（HIFU）作为一种具有巨大潜力的、无损的、有效的肿瘤治疗手段,已得到普遍认同。本文介绍了所研制的HIFU治疗系统,对其关键部分高强度聚焦超声换能器的温度场特性,从理论上和实验上进行了深入的研究,并提出了超声声场的理论算法.     

高强度聚焦超声消融滋养动脉治疗子宫肌瘤的临床价值

目的：探讨高强度聚焦超声消融滋养动脉治疗子宫肌瘤的可行性及有效性。方法：47例直径4~10cm肌壁间肌瘤,高强度聚焦超声治疗前通过彩色多普勒及超声造影确定肌瘤滋养动脉的蒂,对该区域进行消融,观察治疗前后肌瘤内部彩色多普勒及超声造影等影像学变化、随访临床症状及并发症。结果：治疗后肌瘤体积有不同程度的缩小,瘤体假包膜环状血流信号消失,肌瘤内部处于持续无灌注状态,部分患者临床症状消失或明显改善。结论：HIFU消融滋养动脉治疗子宫肌瘤能够缩短治疗时间,减少并发症,是一种微创和有效的方法。     

超声影像方法在预测HIFU治疗子宫肌瘤疗效中的应用

子宫肌瘤是育龄期女性最常见的良性肿瘤,高强度聚焦超声（High Intensity Focused Ultrasound,HIFU）作为一种微创治疗技术,已经广泛运用于子宫肌瘤的治疗,但是对于某些特殊类型的肌瘤消融效率较低,并导致很多严重的并发症。这类肌瘤在二维灰阶超声、多普勒超声、超声造影方面有特殊的表现。对上述超声影像方法在预测HIFU治疗子宫肌瘤疗效中的作用进行了综述。但各种超声影像学技术存在一定误差,提供子宫肌瘤内部微血管灌注信息仍不完全,在未来研究中可使用包括微血管成像技术（Superb Micro-vascular Imaging,SMI）、造影剂微血管灌注成像（Contrast Micro-Imaging,CMI）、磁共振成像（Magnetic Resonance Imaging,MRI）多种技术在内的多模态分析,为HIFU治疗子宫肌瘤疗效预测提供更多参考和信息。     

Annular phased-array high-intensity focused ultrasound device for image-guided therapy of uterine fibroids

An ultrasound (US), image-guided high-intensity focused ultrasound (HIFU) device was developed for noninvasive ablation of uterine fibroids. The HIFU device was an annular phased array, with a focal depth range of 30-60 mm, a natural focus of 50 mm, and a resonant frequency of 3 MHz. The in-house control software was developed to operate the HIFU electronics drive system for inducing tissue coagulation at different distances from the array. A novel imaging algorithm was developed to minimize the HIFU-induced noise in the US images. The device was able to produce lesions in bovine serum albumin-embedded polyacrylamide gels and excised pig liver. The lesions could be seen on the US images as hyperechoic regions. Depths ranging from 30 to 60 mm were sonicated at acoustic intensities of 4100 and 6100 W/cm2 for 15 s each, with the latter producing average lesion volumes at least 63% larger than the former. Tissue sonication patterns that began distal to the transducer produced longer lesions than those that began proximally. The variation in lesion dimensions indicates the possible development of HIFU protocols that increase HIFU throughput and shorten tumor treatment times.