【作者】 周鹏；

【导师】 周平；

【作者基本信息】 中南大学 ， 影像医学与核医学， 2009， 硕士

【摘要】 第一章超声造影评估实质期兔肝VX2瘤血供程度的研究目的:探讨超声造影（CEUS）及其时间强度曲线（TIC）在实质期兔肝VX2瘤血供及血供演变过程评估中的价值,以及实质期兔肝VX2瘤血供变化的病理基础。方法:选用新西兰大白兔20只,直接法植入VX2瘤块于兔左肝。将荷瘤兔随机分为3组,分别于术后10天、15天、20天分别行CEUS,用造影定量分析软件绘制TIC,计算出10d组、15d组、20d组肿瘤及周边正常肝组织的TIC参数—达峰时间（PIT）和绝对峰值强度（AEI）;CEUS后立即处死实验兔,取兔肝肿瘤及周边正常肝组织行病理免疫组化染色,进行微血管密度（MVD）计数和血管内皮生长因子（VEGF）测定。结果:本研究共有18只实验兔建模成功,建模成功率90%。CEUS显示实质期兔肝VX2瘤为富血供,呈典型“快进快出”恶性肿瘤造影声像表现。TIC显示三组肿瘤PIT均短于其正常组织（P＜0.01）,三组肿瘤之间PIT组间比较则无统计学意义（P＞0.05）。肿瘤AEI术后10d组高于15d组,15d组高于20d组,随种植时间的不同,肿瘤的AEI呈逐渐递减趋势（P＜0.01）。肿瘤MVD术后10d组高于15d组,15d组高于20d组,随种植时间的不同,肿瘤的MVD呈逐渐递减趋势（P＜0.05）。10d组、20d组肿瘤的MVD与正常肝组织MVD比较有统计学意义（P＜0.01）,而15d组肿瘤的MVD与正常肝组织MVD无统计学意义（P＞0.05）。三组肿瘤VEGF值两两比较,术后10d组高于术后15d组（P＜0.05）,但15d组与20d组无统计学意义（P＞0.05）,随种植时间的不同,肿瘤的VEGF表达有一定的逐渐递减趋势。肿瘤VEGF表达均明显高于周边正常肝组织（P＜0.01）。肿瘤AEI与MVD呈正相关（r=0.87,P＜0.05）,与VEGF无显著相关性（r=0.45,P=0.06）;肿瘤PIT与MVD及VEGF间无相关性（r=-0.318,P=0.18;r=-0.10,P=0.70）。结论:CEUS及TIC指标AEI能准确定量评估实质期兔肝VX2肿瘤血供状况。实质期兔肝VX2肿瘤血供呈一个“富血供—等血供—乏血供”逐渐递减的演变过程。第二章兔肝VX2瘤血供程度与高强度聚焦超声量效关系的初步研究目的:运用相同高强度聚焦超声（HIFU）辐照参数照射不同血供程度的实质期兔肝VX2肿瘤,术中对肿瘤靶点处温度进行实时测温、术后对凝固性坏死体积大小进行测量,对残留肿瘤组织微血管密度（MVD）进行测定,分析时间温度曲线（TTC）参数及凝固性坏死体积（V）大小与血供程度（MVD）的关系,以探讨血供程度对肿瘤靶点处温度及HIFU后凝固性坏死体积（V）大小的影响,为进一步精确控制HIFU剂量、提高HIFU的治疗效率提供实验依据。方法:制作瘤兔24只并分成4组:富血供组（10d组）、等血供组（15d组）、乏血供组（20d组）、无血供组（10d成模后处死组）。超声引导下将热电偶探针经皮肝穿刺到VX2肿瘤靶点处,测得起始温度（T₀）,用相同HIFU辐照参数照射各组肝肿瘤组织,实时测量中央温度,运用温控仪自带软件做出TTC,获得峰值温度（Tmax）、峰值时间（T₁）、温降时间（T₂）,计算出温升斜率（k₁）,k₁=（Tmax-T₀）/T₁,温降斜率（k₂）,k₂=（Tmax-T₀）/（T₂-T₁）。取出肝脏,观察并测算出凝固性坏死体积（V）。取周边残留肿瘤组织进行病理观察及MVD测定。结果:①HIFU辐照过程肿瘤靶点处TTC表现为“快速达峰,缓慢消退”;②Tmax、T₁、k₁乏血供组、等血供组、富血供组各组间两两比较不具有统计学意义（P＞0.05）,此三组与无血供组组间两两比较具有统计学意义（P＜0.05）;T₂、k₂、V各组间两两比较具有统计学意义（P＜0.05）;③k₂:富血供组＞等血供组＞乏血供组＞无血供组;T₂及V:富血供组＜等血供组＜乏血供组＜无血供组;④Tmax、T₁、k₁与MVD不具有相关性（r=-0.43,0.15,-0.31;P＞0.05）;k₂与MVD呈正相关（r=0.84;P＜0.01）;T₂及V与MVD呈负相关（r=-0.88,-0.92;P＜0.01）。结论:肿瘤血供程度对HIFU“温升”过程无显著影响,而对“冷却”过程及HIFU后凝固性坏死体积大小有显著的影响。肿瘤血供越丰富,HIFU辐照后散热越快,温降时间越短,温降斜率越大,组织越易恢复到正常温度,形成凝固性坏死体积越小。超声造影术前准确评估肿瘤血供程度,可为精确控制HIFU剂量、提高HIFU的治疗效率提供帮助,具有重要的临床价值。更多还原

【Abstract】 Objectives:To study the value of the application of contrastenhanced ultrasonography（CEUS） and time intensity curve（TIC） in evaluating the evolution of the blood supply of rabbit liver VX2 tumor models in its early stage,as well as the pathological basis of rabbit liver VX2 tumor models in its early stage.Methods:Twenty New Zealand white rabbits were selected,VX2 hepatocellular carcinoma cells were implanted directly in the left hepatic lobe of rabbits.The rabbits were divided into 3 groups randomly,CEUS were performed on the 10d,15d,20d after the operation separately, CEUS quantitative analysis software was used to plot TIC,calculate time to peak（PIT） and absolute enhanced intensity（AEI） of hepatic tumor and surrounding normal liver tissue in the 10d group,15d group,20d group. The rabbits were put to death immediately after CEUS,the rabbits’ hepatic tumor and surrounding normal liver tissue were resected for pathology and immuno-histochemistry,microvessel density（MVD） count and vascular endothelial growth factor（VEGF） determination.Results:Eighteen animal models were established successfully,the success rate were 90%.CEUS showed that the rabbit liver VX2 tumor had abundant blood supply in its early stage,presenting a typical malignant tumor imaging "quickly in and quickly out".TIC showed that the PIT of hepatic tumor were shorter than that of surrounding normal liver tissue in three groups（P＜0.01）,PTI of hepatic tumor showed no statistically significant difference among three groups（P＞0.05）.With the prolonging of implant time,AEI of hepatic tumor had a descending trend（P＜0.05）:AEI was higher in 10d group than 15d group,AEI is higher in 15d group than 20d group.With the prolonging of implant time, MVD of hepatic tumor had a descending trend（P＜0.05）:MVD was higher in 10d group than 15d group,MVD was higher in 15d group than 20d group.MVD of hepatic tumor in 10d group and 20d group showed statistically significant difference compared with MVD of surrounding normal liver tissue（P＜0.01）,but MVD of hepatic tumor in 15d group showed no statistically significant difference compared with MVD of surrounding normal liver tissue（P＞0.05）.VEGF of hepatic tumor was higher in 10d group than 15d group（P＜0.05）,but there were no statistically significant difference between 15d group and 20d group （P＞0.05）,With the prolonging of implant time,VEGF of hepatic tumor had a descending trend to a certain extent.VEGF of hepatic tumor were significant higher than surrounding normal liver tissue（P＜0.01）.AEI of hepatic tumor had a positive correlation with MVD of hepatic tumor （r=0.87,P＜0.05）,had no obvious correlation with VEGF of hepatic tumor （r=0.45,P=0.06）;PIT of hepatic tumor had no obvious correlation with MVD and VEGF of hepatic tumor（r=-0.318,P=0.18;r=-0.10,P=0.70）.Conclusions:CEUS and AEI of TIC can give a quantitative assessment for the evolution of the blood supply in rabbit liver VX2 tumor models.The blood supply in its early stage in rabbit liver VX2 tumor models show a gradual descent process from abundant blood supply to medium blood supply to low blood supply. Objectives:The same irradiation parameters of high intensity focused ultrasound（HIFU） were used to irradiate varying degrees of the blood supply of rabbit liver VX2 tumor models in its early stage,and the real-time temperature of target site of tumorwere measured during HIFU, the volume of coagulation necrosis tissue（V） were measured,microvessel density（MVD） of residual tumor tissue were determinated after HIFU.The parameters of time temperature curve（TTC） and the volume of coagulation necrosis tissue correlated with the blood supply extent and MVD were analyzed,in order to explore the effects of the blood supply extent on the temperature of target site of tumorand V,and to provide experimental evidence for further precise control of dosage of HIFU and improve the efficiency of HIFU in the treatment.Methods:Twenty-four rabbit liver VX2 tumor models were established and were divided into 4 groups:abundant blood supply group （10d group）,medium blood supply group（15d group）,low blood supply group（20d group）,non blood supply group（rabbits were put to death in the 10d after the models were established）.Thermocouple probe were used to percutaneous transhepatic puncture to the target site of tumor under ultrasound guidance,onset temperature（T_o） were measured,the same irradiation parameters of HIFU were used to irradiate the hepatic tumor tissue of every group,the real-time temperature of target site of tumorwere measured,The software from temperature controller was used to plot the TTC,the peak temperature(T_max),peak time（T₁）,temperature drop time（T₂） were measured,the temperature rise slope（K₁） and the temperature drop slope（K₂） were calculated,K₁=(T_max-T₀)/T₁, K₂=(T_max-T₀)/（T₂-T₁）.The liver were resected for TTC stained specimens, V were observed and measured.Residual tumor tissue were resected for pathological observation and MVD determination.Results:①During HIFU irradiation,the TTC in the target site of tumor showed a representation of "quickly reach the peak,slowly go down";②T_max,T₁ and K₁ between the groups had no statistical difference among low blood supply group,medium blood supply group,abundant blood supply group（P＞0.05）,K₁ between these three groups with non blood supply group had statistical difference（P＜0.05）;T₂,K₂ and V between the groups had statistical difference（P＜0.05）;③K₂:abundant blood supply group＞medium blood supply group＞low blood supply group＞non blood supply group;T₂ and V:abundant blood supply group＜medium blood supply group＜low blood supply group＜non blood supply group;④T_max,T₁,K₁ had no obvious correlation with MVD （r=-0.43,0.15,-0.31;P＞0.05）;K₂ had a positive correlation with MVD （r=0.84;P＜0.01）;T₂ and V had a negative correlation with MVD（r=-0.88, -0.92;P＜0.01）.Conclusions:The extent of the tumor blood supply had no siginificant effect on HIFU "temperature rise" process,but it had siginificant effect on "temperature drop" process and the volume of coagulation necrosis tissue after HIFU.The more abundant blood supply of the tumor were,the faster heat abstraction after HIFU were,the shorter temperature drop time were,the larger temperature drop slope were,the easier the tissue return to normal temperature,the smaller the volume of coagulation necrosis tissue were.Accurate assessment of the extent of the tumor blood supply with contrast-enhanced ultrasonography before HIFU had important clinical value,it can offer assistance to accurate control of HIFU radiation dose and raise the efficiency of HIFU treatment.更多还原