兔VX2软组织肿瘤TAE治疗前后MSCT灌注成像研究

目的:探讨MSCT灌注成像在兔VX2软组织肿瘤TAE治疗前后疗效监测中的应用价值。方法:12只单侧 大腿近段种有VX2肿瘤的新西兰大白兔,分别于TAE前、后行CT平扫和灌注扫描,计算并分析肿瘤组织的血流量(BF) 和表面通透性(PS),观察TAE治疗前后其血流灌注变化,并与病理结果对照。结果:所有兔大腿VX2肿瘤组织的BF、PS 值明显高于正常肌肉组织和TAE治疗后。结论:MSCT灌注成像是一种准确、方便且相对安全的定量评估软组织肿瘤血 流灌注状态和监测TAE治疗疗效的功能成像方法。     

兔VX2软组织肿瘤MSCT灌注成像与病理对照研究

目的对兔VX2软组织肿瘤进行MSCT灌注成像与病理对照研究,探讨MSCT灌注成像在软组织肿瘤中的应用价值。材料与方法8只新西兰大白兔,双侧大腿近段注射VX2肿瘤组织悬液0．1ml,分别于肿瘤组织接种后第14、21d行CT平扫和灌注扫描,扫描图像经AW4．0工作站处理,计算并分析灌注图像和灌注参数,包括血流量(BF)、血容量(BV)、平均通过时间(MTT)和表面通透性(PS)。随后处死荷瘤兔,取出肿瘤行病理组织学检查,对其微血管密度(micro vascular density,MVD)进行测定,分析MSCT。功能参数图像与肿瘤MVD之间的关系。结果所有兔大腿VX2肿瘤组织BF、BV、PS值明显高于正常肌肉组织,且与肿瘤MVD呈正相关;而MTT值则明显低于正常肌肉组织,与肿瘤MVD无明显相关性。结论MSCT灌注成像是一种准确且相对简单、便捷的定量评估软组织肿瘤性病变血流灌注状态的功能成像方法。     

CT灌注成像监测兔肝VX2肿瘤生长

目的:研究使用CT灌注成像(CTPI)参数监测兔肝VX2肿瘤生长的价值。方法:10只新西兰大白兔,开腹手术于肝右叶内注射VX2肿瘤细胞悬液0.1ml。分别在种瘤前、种瘤后第1周、第3周行CT灌注扫描。应用反卷积算法计算肝脏的灌注参数:血流速(BF)、平均通过时间(MTT)、血容量(BV)、表面通透性(PS)、肝动脉分数(HAF)和到达时间(IRFT0)等。比较在肿瘤生长过程中灌注参数的变化。使用单因素方差分析进行统计学处理。结果:10只兔中共9只成功建立VX2种植模型。9只种植成功的兔肝中CT发现病灶9个,种植后第1周时扫描9只兔均可见肿瘤,直径约为(0.5±0.1)cm,第三周时肿瘤直径(2.6±0.6)cm。种瘤前肝实质、种瘤后第1周和第3周时肿瘤区域CTPI灌注参数BF、BV、PS、HAF、MTT、T0分别为(172.11±10.87)ml/(100g·min)、(31.02±3.02)ml/100g、(16.82±4.34)ml/100g·min、0.1224±0.0068、(11.24±1.20)s、(5.15±0.26)s;(128±5.04)ml/(100g·min)、(25.15±0.86)ml/100g、(14.79±5.18)ml/100g·min、0.7780±0.0514、(9.82±0.47)s、(3.43±0.12)s与(237.00±8.83)ml/(100g·min)、(33.11±1.89)ml/100g、(18.78±6.25)ml/100g·min、0.9440±0.0124、(10.12±0.21)s、(1.86±0.05)s。HAF、T0、BF值比较差异有显著性意义(P<0.05),BV、MTT、PS值差异无显著性意义。结论:CTPI参数HAF、T0、BF值可监测肝脏VX2肿瘤生长过程,较好反映了VX2肿瘤的动脉供血为主的本质,有希望在肝癌的检出及监测中发挥作用。     

VX2肿瘤MSCT灌注与缺氧状态关系的研究

目的 研究VX2肿瘤MSCT血流灌注与缺氧状态之间的关系.材料与方法8只腿部肌肉种植VX2肿瘤的新西兰大白兔,分别于肿瘤生长第7、14、21、28天行MSCT灌注扫描,分别测量肿瘤及正常肌肉组织内血流量(BF)、最大强化指数(PEI)、峰值到达时间(TTP)及血容量(BV)作为灌注指标.肿瘤组织行HIF-1α免疫组织化学染色,根据肿瘤细胞着色深度和阳性细胞百分比统计HIF-1α表达等级.不同时间段HIF-1α等级分布分别进行X2检验,HIF-1α表达等级之间行X2检验,HIF-1α与cT灌注值行Spearman等级相关分析.结果 肿瘤第7、14、21、28天HIF-1α等级由低到高再降低,但其变化差异无统计学意义(X2=1.49,P=0.22),不同时间段CT灌注BF值与HIF-1α表达存在相关性(r=0.87,P<0.05),其他CT灌注值与HIF-1α表达无明显相关性.结论 VX2肿瘤生长过程中均存在缺氧,缺氧状态与CT灌注BF值相关,表明VX2肿瘤血流灌注与肿瘤缺氧状态之间存在依存关系.     

兔VX2脑瘤血管生成的灌注CT研究

目的观察实验性兔VX2脑瘤的灌注CT改变,并与病理及免疫组织化学(简称免疫组化)结果对照,检验灌注CT反映脑瘤血管生成的效能.方法20只VX2脑瘤荷瘤兔按随机数字表分成3周以下组和3周以上组行灌注CT检查,测量肿瘤、瘤周及对侧正常脑组织的血容量(bloodvolume,BV),血流量(bloodflow,BF)和表面通透性(permeability surface,PS).大体标本观察肿瘤伊文思蓝染色级别.免疫组化观察血管内皮生长因子(vascular endothelial growth factor,VEGF)表达率和微血管密度(microvessel density,MVD).结果肿瘤区BV、BF和PS值[分别为(13.25±4.58)ml·100 g-1、(166.14±69.62)ml·100 g-1·min-1、8.01 ml·min-1·100 g-1]均明显高于瘤周[分别为(2.38±0.80)ml·100 g-1、(62.49±25.83)ml·100 g-1·min-1、0.03ml·min-1·100 g-1]及对侧正常脑组织[分别为(2.24±0.75)ml·100 g-1、(55.72±21.24)ml·100 g-1·min-1、0.04ml·min-1·100 g-1]差异有统计学意义(P值均=0.000).3周以上组肿瘤区BV、BF和MVD[分别为(16.41±4.12)ml·100 g-1、(208.77±63.00)ml·100 g-1·min-1、(61.20±12.93)个/高倍视野]均明显高于3周以下组[(10.09±2.27)ml·100 g-1、(123.51±47.18)ml·100 g-1·min-1、(41.40±7.34)个/高倍视野],差异有统计学意义(P值均＜0.01).肿瘤区MVD与BV(r=0.915,P=0.000)和BF(r=0.901,P=0.000)呈显著正相关,与PS(r=0.459,P=0.042)呈正相关;肿瘤蓝染级别与PS(rs=0.861,P=0.000)呈显著正相关.结论灌注CT可明确区分肿瘤与瘤周和正常组织,准确反映肿瘤的血管生成情况,为脑瘤评价提供重要资料.     

VX2肿瘤MSCT灌注与血管生成的关系

目的：研究VX2肿瘤生长过程中微血管生成情况,以及肿瘤微血管密度与MSCT灌注值之间的变化关系。方法：8只荷瘤大白兔分别于肿瘤生长第7、14、21、28天行MSCT灌注扫描,分别测量肿瘤血流量（BF）、最大强化指数（PEI）、峰值到达时间（TTP）及血容量（BV）作为灌注指标。于第7、14、21、28天肿瘤组织行免疫组化CD34染色,进行微血管密度（MVD）计数。不同时间段灌注值比较行方差分析SNK均数比较,各项MSCT各灌注指标与MVD计数之间行Pearson相关分析。结果：肿瘤生长大小分别为（14.1±2.9）mm、（27.7±4.5）mm、（39.5±8.3）mm和（52.5±7.8）mm,第7天MSCT灌注值BF为（135.10±13.08）ml/100g/min,其余灌注参数分别为PEI（73.11±5.25）HU,TTP 18.57±1.38,BV（45.0±2.53）ml/100g,至第28天,相应灌注值为BF（46.05±7.55）ml/100g/min、PEI（70.25±6.25）HU、TTP（35.90±1.90）s、BV（51.63±4.77）ml/100g,第7、14天的CT灌注值与第21、28天灌注值中的BF和TTP差异存在显著性意义,4次灌注中的BV和PEI差异无显著性意义。CT灌注值中的BV与MVD存在相关性,PEI与MVD存在弱相关,BF、TTP与MVD之间没有明显相关性。结论：兔VX2肿瘤灌注值BF在生长早期较高,随肿瘤生长灌注值BF下降。肿瘤BV值和PEI值与VX2肿瘤血管生成存在相关关系,MSCT灌注成像可以反映VX2肿瘤微血管生成特征以及肿瘤在不同生长时期的微血管变化情况。     

兔VX2肿瘤介入治疗前后肿瘤血管生成的多层螺旋CT灌注成像研究

目的 探讨多层螺旋CT（ISCT）灌注成像在定量评价软组织恶性肿瘤介入治疗前后肿瘤血管生成和介入治疗后早期疗效监测中的应用价值。方法 24只成功种植VX2肿瘤的新西兰大白兔，数字表法随机分为介入组和对照组，每组12只，分别于肿瘤种植后第14天、介入治疗后第3天行常规CT平扫和灌注扫描，计算肿瘤组织和正常肌肉组织的血流量（BF）、血容量（BV）、平均通过时间（MTT）和表面通透性（PS）值，分析各参数之间的差异性；并将各灌注参数分别与肿瘤微血管密度（IVD）值和血管内皮生长因子（VEGF）平均吸光度（A）值进行相关性分析。结果 肿瘤种植后第14天，介入组肿瘤BF、BV、MTT、PS值分别为（303．3±69．9）ml·100g^-1·min^-1、（7．02±3．10）ml／100g、（1．99±0．28）s、（65．9±9．4）ml·100g^-1·min^-1，与正常肌肉组织相比[分别为（11．8±5．0）ml·100g^-1·min^-1、（1．04±0．47）ml／100g、（17．92±7．19）s、（13．1±6．4）ml·100g^-1·min^-1]差异有统计学意义（F值分别为4285．82、1867．46、413．04、698．42，P〈0．01）；与对照组肿瘤的各参数值差异无统计学意义（F值分别为2．47、2．03、0．02、0．53，P〉0．05）。介入组肿瘤IVD值和VEGF平均A值分别为（50．1±4．1）个／高倍视野、0．352±0．011，与对照组肿瘤[分别为（50．2±3．7）个／高倍视野、0．352±0．009]差异无统计学意义（F值分别为0．02、0．19，P〉0．05）。介入治疗后第3天（即种植后第18天），介入组肿瘤BF、BY、MTT、PS、MYD值和YEGF平均A值分别为（7．5±24）ml·100g^-1·min^-1、（1．20±0.23）ml／100g、（3．29±0.57）s,（40±1．5）ml·100g^-1·min^-1、（16．0±2．4）个／高倍视野、0．215±0．008，与对照组相比[分别为（390．2±116．3）ml·100g^-1·min^-1、（8．47±2．53）ml／100g、（1．88±0．34）s、（76．9±11．3）ml·100g^-1·min^-1、（84．8±5．6）个／高倍视野、0．366±0．013]差异有统计学意义（F值分别为10166．91、1310．19、272．84、1649．80、1239．72、4168．91，P〈0．01）；与介入治疗前相比，差异也有统计学意义（t值分别为74．53．49．62、-16．82、35．36、50．41、65．64，P〈0．01）。、肿瘤BF、BV、PS值与IVD值和VEGF平均A值呈正相关（r值均〉0．7，P〈0．05）；MTT值与VEGF平均A值呈负相关（r=-0．78，P〈0．05），而与肿瘤IVD值无明显相关性（r=-0．315，P〉0．05）。结论 NSCT灌注成像是一种定量评价肿瘤血管生成、血流灌注及血管通透性改变的功能成像方法，可以无创、准确地对肿瘤介入治疗早期疗效进行定量评价和动态监测。     

兔VX2移植性肝癌模型的制作及影像学评价

目的:探讨开腹注射法制作兔VX2移植性肝癌模型的特点及超声、CT在监测VX2肝癌中的价值。方法:将兔VX2瘤组织块加细胞悬液经开腹注入45只新西兰大白兔的肝左、肝右或肝中叶内,接种后的不同时期行彩超、CT平扫和双期增强扫描。结果:45只兔中40只接种成功,原位成瘤率为88.8%,其中肝脏单发结节者25只(62.5%),多发结节者15只(37.5%),原位成瘤伴异位种植者9只。CT平扫示病灶为低或等密度。增强扫描动脉期有明显强化高密度,门脉期为低密度,肿瘤边缘强化;第2周CT检查阳性率为46.7%,第3周为90.0%,不同时期检出率差异有统计学意义(x~2=4.26,P<0.05)。超声上肿瘤表现为低回声伴声晕,彩色多谱勒可见肿块周边血供丰富;超声检查第2周阳性率为40.0%,第3周为80.0%,不同时期检出率差异有统计学意义(x~2=4.33,P<0.05)。结论:经开腹注射法制作兔肝癌模型是一种简单、易行的方法,但易发生异位种植和多发结节。彩超和CT平扫及增强扫描均是准确、可靠的监测方法。     

肺癌介入治疗前后MSCT灌注成像参数变化的临床意义

目的:探讨中晚期肺癌介入治疗前后MSCT灌注成像灌注参数变化的临床意义。方法:选择29例中晚期肺癌患者,介入治疗前及治疗后4周行MSCT灌注成像,采用电影技术对瘤体中心层面进行动态灌注扫描,计算瘤体的血流量(BF)、血容量(BV)、平均通过时间(MTT)、毛细血管表面通透性(PS),测量并比较介入治疗前后各项灌注参数的变化,并在介入治疗3个月后行常规CT检查观察肿瘤形态变化。结果:24例肺癌介入治疗后,肿瘤BF、BV降低,MTT显著升高,PS变化不明显(差异有统计学意义,P0.05),3个月后随访观察瘤体组织出现不同程度缩小;5例肺癌BF、BV、MTT、PS均无明显变化(P0.05),3个月后随访观察瘤体显示不同程度增大或无明显变化。结论:肺癌介入治疗前后MSCT灌注成像灌注参数变化在肿瘤疗效预测方面有很大的临床意义。     

乳腺肿瘤CT灌注成像价值

目的 探讨乳腺肿瘤CT灌注的诊断价值.方法 对17例钼靶X线检查发现乳腺肿块性病变(21个病灶)行CT灌注扫描,使用电影模式,0.5 s/圈 ,5 mm层厚×4,120 kV,60 mA,延迟时间10 s,总扫描时间50 s,使用GE AW4.2工作站和Perfusion 3软件包,对生成的动态图像数据和图像强度随时间变化的相关信息进行分析,考察各种与灌注相关的参数情况,并进行统计学分析.结果 乳腺癌组:血流量(BF)(36.46±17.62)ml·min-1· 100 g-1,血容量(BV)(13.76±8.59)ml/100 g,平均通过时间(MTT)(28.23±15.75)s,血管表面通透性(PS)(16.45±12.36)ml·min-1 ·100 g-1,良性肿块组血流量(BF)(17.35±10.67)ml·min-1· 100 g-1.良性肿块组:血容量(BV)(4.63±3.47)ml/100 g,平均通过时间(MTT)(25.52±12.91)s,血管表面通透性(PS)(3.57±3.36)ml·min-1 ·100 g-1.2组BF、BV、PS之间的差异有统计学意义(P＜0.05).结论 CT灌注成像提供了乳腺肿块的血流动力学信息,在乳腺肿块性病变的良恶性鉴别诊断中有较高的参考价值.     

Effect of microbubble contrast agent during high intensity focused ultrasound ablation on rabbit liver in vivo

Objective

To evaluate the effect of a microbubble contrast agent (SonoVue) during HIFU ablation of a rabbit liver.

Materials and methods

HIFU ablations (intensity of 400 W/cm² for 4 s, six times, with a 5 s interval between exposures) were performed upon 16 in vivo rabbit livers before and after intravenous injection of a microbubble contrast agent (0.8 ml). A Wilcoxon signed rank test was used to compare mean ablation volume and time required to tissue ablation on real-time US. Shape of ablation and pattern of coagulative necrosis were analyzed by Fisher's exact test.

Results

The volume of coagulative necrosis was significantly larger in the combination microbubble and HIFU group than in the HIFU alone group (P < 0.05). Also, time to reach ablation was shorter in the combination microbubble and HIFU group than in the HIFU alone group (P < 0.05). When analyzing the shape of tissue ablation, a pyramidal shape was more prevalently in the HIFU alone group compared to the combination microbubble and HIFU group (P < 0.05). Following an analysis of the pattern of coagulative necrosis, non-cavitary necrosis was found in ten and cavitary necrosis in six of the samples in the combination microbubble and HIFU group. Conversely, non-cavitary necrosis occurred in all 16 samples in the HIFU alone group (P < 0.05).

Conclusion

HIFU of in vivo rabbit livers with a microbubble contrast agent produced larger zones of ablation and more cavitary tissue necrosis than without the use of a microbubble contrast agent. Microbubble contrast agents may be useful in tissue ablation by enhancing the treatment effect of HIFU.     

Microbubbles assist goat liver ablation by high intensity focused ultrasound

High intensity focused ultrasound (HIFU) has been introduced to treat cancers. However, this therapy is a time-consuming procedure; destructing a deeper volume is also difficult as ultrasonic energy attenuates exponentially with increasing depth in tissues. The aim of the present study was to investigate the effects of introducing microbubbles on liver HIFU ablation. Seventeen goats were divided into groups A (n=8) and B (n=9). The livers in both groups were ablated using HIFU (1.0 MHz, 22,593 W/cm²) performed in the manner of a clinical regime using a clinical device. A microbubble agent was bolus-injected intravenously before HIFU exposure in group B. All animals in group A and seven goats in group B were euthanased to evaluate the ablation efficiency 24 h after HIFU. The necrosis rate (mm³/s), which was the volume of necrosis tissue per second of HIFU exposure, was used to judge the ablation efficiency. Pathological examinations were performed to determine whether there were residual intact tissues within the exposed volume. The other two goats in group B were used to determine the delayed pathological changes 7 days after ultrasonic ablation. The necrosis rate (mm³/s) was increased in group B (14.4647±4.1960 versus 33.5302±12.4484, P=0.0059). Pathological examinations confirmed that there were no residual unaffected tissue focuses within the exposed volume. Two remarkable changes occurred in the other two goats in group B 7 days after HIFU: there were ghost-cell islands at the periphery of the ablated tissues, and surrounding adjacent tissues outside the reactive zone necrotized. These findings showed that microbubbles could be used to assist liver HIFU ablation. T. Yu and X. Fan contributed equally to this paper.     

Renal ablation using magnetic resonance-guided high intensity focused ultrasound: Magnetic resonance imaging and histopathology assessment

AIM: To use magnetic resonance-guided high intensity focused ultrasound (MRg-HIFU), magnetic resonance imaging (MRI) and histopathology for noninvasively ablating, quantifying and characterizing ablated renal tissue.METHODS: Six anesthetized/mechanically-ventilated pigs underwent single/double renal sonication (n = 24) using a 3T-MRg-HIFU (1.1 MHz frequency and 3000J-4400J energies). T2-weighted fast spin echo (T2-W), perfusion saturation recovery gradient echo and contrast enhanced (CE) T1-weighted (T1-W) sequences were used for treatment planning, temperature monitoring, lesion visualization, characterization and quantification, respectively. Histopathology was conducted in excised kidneys to quantify and characterize cellular and vascular changes. Paired Student’s t-test was used and a P-value < 0.05 was considered statistically significant.RESULTS: Ablated renal parenchyma could not be differentiated from normal parenchyma on T2-W or non-CE T1-W sequences. Ablated renal lesions were visible as hypoenhanced regions on perfusion and CE T1-W MRI sequences, suggesting perfusion deficits and necrosis. Volumes of ablated parenchyma on CE T1-W images in vivo (0.12-0.36 cm³ for single sonication 3000J, 0.50-0.84 cm³, for double 3000J, 0.75-0.78 cm³ for single 4400J and 0.12-2.65 cm³ for double 4400J) and at postmortem (0.23-0.52 cm³, 0.25-0.82 cm³, 0.45-0.68 cm³ and 0.29-1.80 cm³, respectively) were comparable. The ablated volumes on 3000J and 4400J double sonication were significantly larger than single (P < 0.01), thus, the volume and depth of ablated tissue depends on the applied energy and number of sonication. Macroscopic and microscopic examinations confirmed the locations and presence of coagulation necrosis, vascular damage and interstitial hemorrhage, respectively.CONCLUSION: Contrast enhanced MRI provides assessment of MRg-HIFU renal ablation. Histopathology demonstrated coagulation necrosis, vascular damage and confirmed the volume of damage seen on MRI.     

高强度聚焦超声消融治疗子宫肌瘤疗效观察

 目的 观察高强度聚焦超声(high intensity focused ultrasound, HIFU)消融治疗子宫肌瘤的疗效。方法 应用HIFU消融技术治疗74例子宫肌瘤患者,术中应用造影剂显影随时观察治疗效果,治疗后连续1周电话询问患者有无不适反应,随访治疗后1、3、6、12个月临床症状的改善情况,以及3、6、12个月复查B超,与治疗前对比评价治疗效果。结果 临床表现为月经过多、尿频、便秘、贫血的患者治疗后症状明显好转,治疗前共76例次,治疗后1、3、6、12个月分别好转51、63、72、75例次,好转率依次为67.1%、82.9%、94.7%、98.7%;治疗后3、6、12个月子宫肌瘤体积逐渐缩小,中位数(四分位数间距)分别为38.43(49.64)cm³、23.07(35.70)cm³、11.67(12.63)cm³,与治疗前比较,差异均有统计学意义(Z值分别为7.391、7.424、7.424,P＜0.01),治疗后6个月、12个月与治疗后3个月比较,差异均有统计学意义(P＜0.01);而治疗后6个月与12个月比较,变化不明显,差异无统计学意义。结论 HIFU消融技术可使肿瘤体积明显缩小,临床症状得到显著改善,是一种可保留子宫且安全、有效治疗子宫肌瘤的理想方法。     

Toward MR-guided high intensity focused ultrasound for presurgical localization: focused ultrasound lesions in cadaveric breast tissue

Purpose:

To investigate magnetic resonance image‐guided high intensity focused ultrasound (MR‐HIFU) as a surgical guide for nonpalpable breast tumors by assessing the palpability of MR‐HIFU‐created lesions in ex vivo cadaveric breast tissue.

Materials and Methods:

MR‐HIFU ablations spaced 5 mm apart were made in 18 locations using the ExAblate2000 system. Ablations formed a square perimeter in mixed adipose and fibroglandular tissue. Ablation was monitored using T1‐weighted fast spin echo images. MR‐acoustic radiation force impulse (MR‐ARFI) was used to remotely palpate each ablation location, measuring tissue displacement before and after thermal sonications. Displacement profiles centered at each ablation spot were plotted for comparison. The cadaveric breast was manually palpated to assess stiffness of ablated lesions and dissected for gross examination. This study was repeated on three cadaveric breasts.

Results:

MR‐ARFI showed a collective postablation reduction in peak displacement of 54.8% ([4.41 ± 1.48] μm pre, [1.99 ± 0.82] μm post), and shear wave velocity increase of 65.5% ([10.69 ± 1.60] mm pre, [16.33 ± 3.10] mm post), suggesting tissue became stiffer after the ablation. Manual palpation and dissection of the breast showed increased palpability, a darkening of ablation perimeter, and individual ablations were visible in mixed adipose/fibroglandular tissue.

Conclusion:

The results of this preliminary study show MR‐HIFU has the ability to create palpable lesions in ex vivo cadaveric breast tissue, and may potentially be used to preoperatively localize nonpalpable breast tumors. J. Magn. Reson. Imaging 2012;35:1089‐1097. © 2011 Wiley Periodicals, Inc.     

超声微泡对比剂增强高强度聚焦超声治疗作用研究进展

高强度聚焦超声(HIFU)是非侵袭性治疗肿瘤的一种重要手段,其安全性、有效性已得到医患的一致认可,但治疗时间长,消融效率低限制了其应用.近年来,关于HIFU增效剂的研究已有进展,超声微泡对比剂作为一种安全有效的HIFU增效剂,能有效缩短治疗时间,提高消融效率,是当前研究的热点.本文就超声对比剂增强HIFU治疗作用的现状及进展作一综述.     

Therapeutic response assessment of high intensity focused ultrasound therapy for uterine fibroid: utility of contrast-enhanced ultrasonography

PURPOSE: To assess the utility of contrast-enhanced ultrasonography (ceUS) in the assessment of the therapeutic response to high intensity focused ultrasound (HIFU) ablation in patients with uterine fibroid. MATERIALS AND METHODS: Sixty-four patients with a total of 64 uterine fibroids (mean: 5.3+/-1.2 cm; range: 3.2-8.9 cm) treated with HIFU ablation under the ultrasound guidance were evaluated with ceUS after receiving an intravenous bolus injection of a microbubble contrast agent (SonoVue) within 1 week after intervention. We obtained serial ceUS images during the time period from beginning to 5 min after the initiation of the bolus contrast injection. All of the patients underwent a contrast enhanced MRI (ceMRI) and ultrasound guided needle puncture biopsy within 1 week after HIFU ablation. And as a follow-up, all of the patients underwent US at 1, 3, 6 and 12 months after HIFU treatment. The volume change was observed and compared to pre- and post-HIFU ablation. The results of the ceUS were compared with those of the ceMRI in terms of the presence or absence of residual unablated tumor and pathologic change in the treated lesions. RESULTS: On ceUS, diagnostic accuracy was 100%, while residual unablated tumors were found in three uterine fibroids (4.7%) and failed treatment was found in eight uterine fibroids (12.5%). All the 11 fibroids were subjected to additional HIFU ablation. Of the 58 ablated fibroids without residual tumors on both the ceUS and ceMRI after the HIFU ablation, the volumes of all the fibroids decreased in different degrees during the 1 year follow-up USs. And histologic examinations confirmed findings of necrotic and viable tumor tissue, respectively. CONCLUSION: CEUS is potentially useful for evaluating the early therapeutic effect of percutaneous HIFU ablation for uterine fibroids.     

MRI评价子宫肌瘤HIFU术的价值及观察周围组织变化的研究进展

子宫肌瘤是子宫最常见的良性肿瘤,可引起月经量过多、腹痛乃至进一步影响生育功能,且有潜在的恶变倾向。诊断方法主要依靠超声及MRI,MRI空间分辨力及软组织分辨力高且受干扰因素较少,临床上常用于高强度聚焦超声消融(HIFU)术前定位及术后常规疗效评估,且在明确显示肿瘤大小、数目及邻近组织细微解剖方面明显优于超声。综述MRI观察子宫肌瘤及周围组织HIFU术前后的变化。     

Early modifications of hepatic perfusion measured by functional CT in a rat model of hepatocellular carcinoma using a blood pool contrast agent

Macromolecular contrast-enhanced functional CT was performed to characterize early perfusion changes in hepatocellular carcinoma (HCC). Fourteen rats with chemically induced primary liver tumors ranging pathologically from hyperplasia to HCC and 15 control rats were investigated. Two dynamic CT scans using an experimental macromolecular contrast agent were performed on a single slice 11 and 18 weeks after tumor induction followed by pathological examination. A deconvolution mathematical model was applied, yielding the hepatic perfusion index (HPI), mean transit time (MTT), liver distribution volume (LDV) and arterial, portal and total blood flows (FA, FP, FT). Analysis was performed on one slice per rat, containing overall two hyperplasia, six dysplasia and 15 HCC. On the first scans, HCC at an early pathological stage had a low FP (–30%, P=0.002) but a normal arterial-portal balance. On the scan contemporary to pathology, HCC perfusion parameters showed an inversion of the arterial-portal balance (HPI +212%, P<0.0001), with a high FA (+56%, P=0.002) and a low FP (–69%, P<0.0001). Sensitivity and specificity of detection of HCC by perfusion CT were high (87 and 80%) on late scans; but also on the earlier scans (86 and 65%), even though only one (7%) was visible to the eye. Perfusion-CT allowed early detection of HCC. This technique could contribute in the detection and characterization of liver lesions in clinical studies.