【作者】 孙杰；

【导师】 邓又斌；

【作者基本信息】 华中科技大学 ， 影像医学与核医学， 2013， 博士

【摘要】 第一部分超声造影定量评价动脉粥样硬化斑块新生血管及其与组织病理学相关性研究目的：应用超声造影技术定量评价动脉粥样硬化斑块显像强度及其与病理染色所示的微血管密度的相关性。方法：新西兰白兔25只球囊扩张+高脂喂养至16周后行常规超声检查观察斑块类型,以右肾动脉为参考,记录每个斑块距离右肾动脉的长度,以便取病理标本时可以精确定位。经耳缘静脉团注Sovovue0.4ml行基础超声造影检查,肉眼观察斑块有无增强,将图像导入EchoPAC工作站手动勾画斑块的边缘轮廓以构建感兴趣区,同时取管腔为对比,应用仪器中所附的时间强度曲线分析软件定量分析注射超声造影剂后的回声增强强度,曲线拟和,获取斑块注射造影剂微泡后超声增强强度A值(曲线拟合后平台期强度与基础强度之差)及其与管腔内增强强度的比值,以此定量表示注射超声造影剂后斑块超声反射回声增强强度,比较软斑与硬斑增强程度的差异。所有检查结束后过量麻醉后处死,分离腹主动脉及右肾动脉,并依据斑块在二维超声上距离右肾动脉的长度定位斑块并取材固定,CD31染色观察斑块内新生血管的密度。结果：二维超声诊断为软斑的斑块其造影增强强度明显高于硬斑；病理检查发现超声判定为软斑的斑块经CD31染色后新生血管数目明显多于超声判定为硬斑的斑块,斑块内微血管的密度与斑块造影增强强度存在明显的相关性(R=0.75,P<0.001),与斑块增强强度/管腔增强强度亦存在明显相关性(R=0.68,P<0.001)。结论：超声造影可以定量评价斑块的增强情况,定量测量得到的斑块增强强度与斑块内新生血管的密度具有良好的相关性,进而为定量评价斑块内微血管的密度提供了一个可靠的方法。第二部分血管活性物质对超声造影定量评价动脉粥样硬化斑块新生血管显像强度的影响目的：应用超声造影技术定量评价动脉粥样硬化斑块显像强度其与血管活性物质的关系。方法：新西兰白兔25只采用球囊扩张+高脂喂养至16周后行常规超声检查观察斑块类型。经耳缘静脉团注Sovovue0.4ml行基础超声造影检查,肉眼观察斑块有无增强,将图像导入EchoPAC工作站手动勾画斑块的边缘轮廓以构建感兴趣区,同时取管腔为对比,应用仪器中所附的时间强度曲线分析软件定量分析注射超声造影剂后的回声增强强度,曲线拟和,获取斑块注射造影剂微泡后超声增强强度A值(曲线拟合后平台期强度与基础强度之差)及其与管腔内增强强度的比值,以此定量表示注射超声造影剂后斑块超声反射回声增强强度,比较软斑与硬斑增强程度的差异。血压及心率恢复正常且造影剂完全消退后分别滴注去甲肾上腺素、三磷酸腺苷后行超声造影检查,重复观测动脉粥样硬化(AS)斑块的增强情况。采用SPSS15.0软件,所有计量资料以均数±标准差表示,以P<0.05为差异有统计学意义。软斑与硬斑造影强度的比较采用非配对T检验。滴注去甲肾上腺素及三磷酸腺苷后斑块增强强度、增强强度与管腔比值与基础造影的比较采用配对T检验。结果：经二维超声检查共发现可用斑块63个,其中经超声检查判定为软斑50个,硬斑13个。滴注去甲肾上腺素后2个斑块显像欠佳而剔除,滴注三磷酸腺苷后1个斑块显像欠佳而剔除。二维超声诊断为硬斑的斑块其造影增强强度明显低于软斑(5.76±2.31vs7.97±2.63,P=0.008)；在滴注去甲肾上腺素后斑块造影增强强度及其与管腔增强强度比值均低于基础状态下的增强强度(6.41±2.90vs7.51±3.81,P<0.001；0.38±0.17vs0.45±0.16,P=0.002),而滴注三磷酸腺苷后斑块增强强度其与管腔增强强度比值均高于基础增强强度(9.78±3.54vs7.49±2.72,P<0.001；0.59±0.23vs0.46±0.17,P<0.001)。结论：血管活性物质可影响斑块新生血管的显像强度,超声造影可以定量评估AS斑块新生血管显像强度及血管活性物质对其影响,进而可以更为全面的评价AS斑块的稳定性。第三部分超声造影定量评价动脉粥样硬化斑块新生血管显像强度及内皮活性物质的影响目的：应用超声造影技术定量评价动脉粥样硬化斑块显像强度其与血管内皮状态的关系。方法：新西兰白兔25只采用球囊扩张+高脂喂养至16周后行常规超声检查观察斑块类型。经耳缘静脉团注Sonovue0.4ml行基础超声造影检查,肉眼观察斑块有无增强,将图像导入EchoPAC工作站手动勾画斑块的边缘轮廓以构建感兴趣区,同时取管腔为对比,应用仪器中所附的时间强度曲线分析软件定量分析注射超声造影剂后的回声增强强度,曲线拟和,获取斑块注射造影剂微泡后超声增强强度A值(曲线拟合后平台期强度与基础强度之差)及其与管腔内增强强度的比值,以此定量表示注射超声造影剂后斑块超声反射回声增强强度,比较软斑与硬斑增强程度的差异。血压及心率恢复正常且造影剂完全消退后分别滴注单甲基精氨酸(LNMMA)、内皮受体阻滞剂(PD142893)后行超声造影检查,重复观测动脉粥样硬化(AS)斑块的增强情况。采用SPSS15.0软件,所有计量资料以均数±标准差表示,以P<0.05为差异有统计学意义。软斑与硬斑造影强度的比较采用独立样本T检验。滴注LNMMA及PD142893后斑块增强强度、增强强度与管腔比值与基础造影的比较采用配对T检验。结果：经二维超声检查共发现可用斑块63个,其中经超声检查判定为软斑50个,硬斑13个。63个斑块滴注LNMMA及PD142893后由于各种显像原因导致分别有16个,9个斑块被剔除。二维超声诊断为硬斑的斑块其造影增强强度明显低于软斑(5.76±2.31dB vs7.97±2.63dB, P=0.008);在滴注LNMMA后斑块造影增强强度及其与管腔增强强度比值均低于基础状态下造影的增强强度(5.48±1.57dB vs7.04±2.26dB,P<0.001；0.40±0.13vs0.46±0.17,P=0.003),在滴注PD142893后斑块造影增强强度及其与管腔增强强度比值均高于基础状态下造影的增强强度(8.31±3.29dB vs7.41±2.85dB,P=0.018；0.51±0.22vs0.45±0.17,P=0.012)。结论：内皮活性物质的浓度影响斑块的显像强度,超声造影可以定量评估AS斑块新生血管显像强度及其受内皮收缩或舒张的影响程度,进而可以更为全面的评价AS斑块的稳定性。更多还原

【Abstract】 PartⅠCorrelation of enhanced intensity of atherosclerotic plaque at contrast-enhanced ultrasonography with histological findingsObjectives:To evaluate the relationship between plaque neovascularization and plaque enhanced intensity by contrast-enhanced ultrasonography.Methods:25New Zealand white rabbits were fed with high fat diet to16weeks. CEU was performed to observe plaque echogenicity. Time-intensity curve was used to quantify the El of plaques. After harvesting the aorta, CD31stain was performed for calculating the density of neovascularization.Results:The echolucent plaques had higher E during CEU and higher neovascularization density at pathological stain than the echogenic plaques.The atherosclerotic plaque El and its ratio to luminal El were well related with neovascularization density (R=0.75, P<0.001; R=0.68, P<0.001) respectively.Conclusions:The atherosclerotic plaque enhanced intensity during CEU was well correlated to neovascularization density.CEU can assess the enhanced intensity of atherosclerotic plaque quantitatively, thus providing us a reliable way for evaluating the neovascularization of atherosclerotic plaque. Part ⅡThe Evaluation of Effects of Vasoactive Substances on Plaque Enhanced Intensity during Contrast-Enhanced UltrasonographyObjects:To evaluate the effects of vasoactive substances on plaque enhanced intensity during contrast-enhanced ultrasonography.Method:25New Zealand white rabbits were fed with a high fat and cholesterol diet for16weeks following balloon injury. Routine ultrasonic examinations were performed to classify the plaques into echolucent or echogenic according to their echogenicities. Rabbits were intravenously administered a0.4mL Sonovue bolus to perform the contrast examination. The images were stored in EchoPAC work station. Enhanced intensity in each frame was measured in the plaque drawn as a region of interest. Curve fitting was done with the formula Y(t)=A(1-e-kt)+B to get the enhanced intensity of the plaques and the lumen by computing the variation of plateau intensity and initial intensity. The enhanced intensity was then compared between the echolucent and the echogenic plaques. The rabbits were later injected with noradrenalin (NA), triphosadenine(ATP) respectively after the heart rate and blood pressure recovered, and repeat examination was done with contrast agent and enhanced intensity of the plaque was quantified again. SPSS15.0software was used to calculate the statistical characteristics of the data. All the measured data were displayed as mean±standard deviation. P<0.05was defined as having statistical significant difference. Independent sample T test was applied to analyze the variation between echolucent and echogenic plaques. The variation of enhanced intensity at baseline and after injecting NA or ATP was analyzed by paired T test.Results:The echolucent plaques expressed higher enhanced intensity than echogenic plaques (7.97±2.63dB vs.5.76±2.31dB, P=0.008). After administration of NA, plaque enhanced intensity and its ratio to lumen were lower than the base values (6.41±2.90vs7.51±3.81, P<0.001;0.38±0.17vs0.45±0.16,P=0.002) whereas the intensity and its ration to lumen after injecting ATP were higher than baseline(9.78±3.54vs7.49±2.72, P<0.001;0.59±0.23vs0.46±0.17, P<0.001).Conclusion:The enhanced intensity of the plaque can be affected by vasoactive substances. CEU may be useful to quantify the enhanced intensity of the plaque and the degree by which it is affected by vasoactive substances. It would then play an important role in evaluating the stability of atherosclerotic plaque. Part IIIThe Evaluation of effects of Endothelial Active Substances on Plaque Enhanced Intensity during Contrast-Enhanced UltrasonographyObjects:To evaluate the effects of endothelial active substances on plaque enhanced intensity during contrast-enhanced ultrasonography.Method:25New Zealand white rabbits were fed with a high fat and cholesterol diet for16weeks following balloon injury. Routine ultrasonic examination was performed to classify the plaques into echolucent or echogenic according to their echogenicities. Rabbits were intravenously administered a0.4mL Sonovue bolus to perform the contrast examination. The images were stored in EchoPAC work station. Enhanced intensity in each frame was measured in the plaque drawn as a region of interest. Curve fitting was done with the formula Y(t)=A(1-e-kt)+B to get the enhanced intensity of the plaques and the lumen by computing the variation of plateau intensity and initial intensity. The enhanced intensity was then compared between the echolucent and the echogenic plaques. The rabbits were later injected with Methyl Arginine (LNMMA) and endothelial blockers (PD142893) respectively when the heart rate and blood pressure recovered, and repeat examination was done with contrast agent and enhanced intensity of the plaque was quantified again. SPSS15.0software was used to calculate the statistical characteristics of the data. All the measured data were displayed as mean±standard deviation. P<0.05was defined as having statistical significant difference. Independent sample T test was applied to analyze the variation between echolucent and echogenic plaques. The variation of enhanced intensity at baseline and after injecting LNMMA or PD142893was analyzed by paired T test.Results:The echolucent plaques expressed higher enhanced intensity than echogenic plaques (7.97±2.63dB vs.5.76±2.31dB,P=0.008). After administration of LNMMA, plaque enhanced intensity and its ratio to lumen were lower than the base values (5.48±1.57dB vs7.04±2.26dB,P<0.001;0.40±0.13vs0.46±0.17, P=0.003) whereas the intensity and its ratio to lumen was higher after injecting PD142893(8.31±3.29dB vs7.41±2.85dB, P=0.018;0.51±0.22vs0.45±0.17, P=0.012).Conclusion:The enhanced intensity of the plaque can be affected by endothelial active substances. CEU may be useful to quantify the enhanced intensity of the plaque and the degree by which it is affected by endothelial active substances. It would then play an important role in evaluating the stability of atherosclerotic plaque.更多还原