64排128层CT血管造影评价动脉粥样硬化早期斑块的实验研究

  本文关键词：64排128层CT血管造影评价动脉粥样硬化早期斑块的实验研究，由笔耕文化传播整理发布。

        背景近年来，随着人们生活水平的提高，冠心病的发病率逐年增加，已经成为发达国家严重危害人们健康的主要疾病之一。美国心脏病学会(American HeartAssociation,AHA)的2002年统计资料显示，心血管疾病占全美总死亡的40.1%，其中冠心病死亡占心血管疾病死亡的55%。在我国，冠心病的患病率和死亡率也有逐年增加趋势。据流行病学资料统计，20世纪50年代末，冠心病在北京和上海40岁以上人群中的患病率为2.45%和3.18%；20世纪70年代全国22个省市的调查显示，冠心病的患病率上升为6.46%；北京地区调查显示，冠心病的病死率1976年为21.7/10万人，1988年为88/10万人，1992年为96/10万人，近年来仍在不断上升。因此，冠心病已成为严重威胁人类健康的疾病，在我国也迅速成为头号杀手，其导致医疗费用的消耗也极大增加了家庭和社会的负担。冠心病的基础病变是动脉粥样硬化（AS）。动脉粥样硬化是累及体循环系统的从大型肌弹力型（如主动脉）到中型肌弹力型（如冠状动脉）动脉内膜的疾病。其特征的病变是从动脉内膜开始，先后有脂质和复合糖类积聚、出现和血栓形成、纤维组织增生和钙质沉着，并有动脉中层的逐渐退变和钙化。2003年Naghavi建议统一使用易损斑块(vulnerable plaque）来形容所有有危险的斑块，此种斑块常具有纤维帽较薄，脂质核心大，炎性细胞活跃等特点，属于早期斑块，引起管腔狭窄仅为轻-中度，易损斑块的破裂可导致血小板聚集和血栓形成，成为急性冠脉综合征和冠心病猝死的主要原因。基础实验和临床研究也均得到了早期动脉粥样硬化斑块通过及时干预可以逆转的证据。所以，临床急需寻找一种快捷、简便、无创的影像学方法探查早期斑块。目前临床用于评价粥样硬化斑块的主要方法有：血管内超声(IVUS)、DSA、光学相干断层成像(OCT)、多层螺旋CT (MSCT)、MRI等，但前三种方法均为有创性检查、且价格昂贵，不宜作为常规检查；MRI检查虽然软组织分辨率高，但检查时间长，对于运动伪影极为敏感，因此实验结果无法取得满意效果。多层螺旋CT血管造影属无创性检查，因其快捷、高效、价格适中、方便、可反复进行等成为目前研究动脉粥样硬化斑块的重要手段。它对于动脉粥样硬化中晚期病变的诊断价值已得到公认，但是对于早期斑块的研究目前仍不多。本研究选择基础病理学和病理生理学上与人动脉粥样硬化斑块具有一定相似性的兔作为实验动物模型，对比病理检查，以期客观评价128层螺旋CT血管造影的特点，评估其判断早期动脉粥样硬化斑块的能力及局限性。第一部分动脉粥样硬化斑块模型的制作目的通过高脂饮食建立兔的动脉粥样硬化模型，探讨简便、易行、有效的动物实验模型制作方法，并通过病理解剖验证动物模型的可靠性。材料与方法54只健康新西兰大白兔，随机分为四组，12周后建模成功，分别为对照组20只，实验组A（单纯高脂饮食）26只，实验组B（高脂饮食+褪黑素干预）2只，实验组C（高脂饮食+瑞舒伐他汀）2只。所有兔在MSCTA检查后处死,分离取出主动脉，先肉眼观察主动脉内壁，行数码相机摄影后，分段制成病理切片观察。实验组A+实验组B+实验组C定为实验组。采用x2分析及确切概率法，分别清点实验组和对照组有斑块段数和无斑块段数，以及实验组A、实验组B及实验组C有斑块的血管段数和无斑块的血管段数。所有数据采用SPSS19.0软件进行。结果（1）全部横断面病理切片共150层，其中实验组动物的90层切片中发现斑块80层，对照组中均未发现斑块，统计分析表明实验组与对照组具有明显差异(P<0.001)，差别有统计学意义；两两对比实验组A、实验组B和实验组C的斑块形成概率，，P<0.001，差别有统计学意义。（2）对照组主动脉柔软有弹性，管腔内膜光滑；实验组主动脉管壁明显增厚、僵硬，可见白色条纹状隆起（实验组B及C的斑块数量和管壁厚度均不如实验组A明显）。结论（1）通过高脂饮食法喂养新西兰大白兔建立动脉粥样硬化模型是可行的，为后续进一步研究早期斑块的影像学表现提高可靠的平台。（2）褪黑素和瑞舒伐他汀具有抗动脉粥样硬化斑块的作用。第二部分动脉粥样硬化早期斑块在MSCT血管造影的表现目的探讨128层螺旋CT血管造影对于兔动脉粥样硬化早期斑块的诊断价值及其局限性。方法沿用实验第一部分制作完成的2组（46只）兔动脉粥样硬化模型（对照组20只，高脂饮食组26只），分别行64排128层螺旋CT血管造影检查，对比病理解剖，总结动脉粥样硬化早期斑块的表现；同时随机选取2只高脂组兔的所有血管横断面图像进行窗宽、窗位的调节，分别记录观察到斑块的层面数，并对比大体解剖，所有数据采用SPSS19.0软件包处理，利用x2检验及确切概率法,分析不同窗宽、窗位观察下早期斑块的显示概率，规定p<0.05有统计学意义。结果（1）20只正常饲养兔血管正常，CTA未见明显异常。（2）26只高脂饮食兔的血管大体观内膜表面均布满脂纹及脂斑，分析对应于78张病理切片的血管横断面图像，有75层（96.2%）血管断面显示主动脉失去正常的圆滑形态，甚至呈多边形，中间明亮的对比剂充盈的管腔被周围模糊样不规则“光晕”即主动脉壁环绕，且其中36层（46.2%）在管腔不规则的同时尚可见管壁偏心性增厚及小充盈缺损凸向管腔内。所有兔血管腔均未见明显狭窄。（3）窗宽、窗位为（200HU,200HU）、（250HU,200HU）、（300HU,200HU）、（350HU,200HU）、（400HU,200HU）、（450HU,200HU）、（500HU,200HU）、（550HU,200HU），（600HU,200HU）时对早期斑块的显示概率的差别有统计学意义；而组间观察窗宽、窗位分别为（200HU,200HU）、（250HU,200HU）时对早期斑块的显示概率的差别不大，差别没有统计学意义，随着窗宽的增加，其对于斑块的显示率逐渐下降。结论64排128层螺旋CT血管造影是研究动脉粥样硬化斑块的一种重要手段，它可以早期发现动脉粥样硬化，对于早期进行药物干预，逆转斑块的病理进程有着重要意义。它对动脉粥样硬化早期血管的改变以横断面图像显示率最高，主要表现为动脉管腔形态的改变，管腔失去圆滑形态，部分表现为小充盈缺损；正确的窗宽、窗位对于显示率很重要，窄窗更有利于早期斑块的显示及观察血管改变；但是它也具有一定局限性。

    Background and purpose：In recent years, with the improvement of people’s livingstandards, the incidence of the coronary heart disease is increase, has become one of theserious threats to people’s health and major diseases in developed countries.In the AHA2002statistics show that cardiovascular disease accounted for40.1%of the total deathsacross the United States, died of coronary heart disease accounted for55%ofcardiovascular disease mortality.In our country, there is an increasing trend on themorbidity and mortality of coronary heart disease.According to the epidemiologicaldata and statistics in the late1950of the20th century, of coronary heart disease inBeijing and Shanghai, the prevalence in the population over the age of40is2.45%and3.18%;In the1970of the20th century survey of22provinces and municipalitiesthroughout the country, the prevalence of coronary heart disease increased to6.46%;Survey in Beijing area, coronary heart disease mortality in1976to21.7/100,000persons, and in1988increased to88/100,000persons, and for1992, rose to92/100,000persons,there is still on the rise in recent years.Therefore, diseases of the coronary heartdisease has become a serious threat to human health, it is fast becoming the number onekiller in China, the medical cost of consumption is also significantly increased theburden on the family and society.The underlying disease of coronary heart disease is atherosclerosis(AS).Atherosclerosis is involved in the circulatory system of large-muscle stretch (asaorta) to midsize muscle stretch (as coronary) disease of the artery intima.Itscharacteristic lesions are starting from the inner lining of an artery, he and a fat mass and accumulation of complex carbohydrates, and thrombosis, fibrous tissue hyperplasiaand Calcinosis occurs, with middle-level progressive degeneration and calcification ofarteries.2003Naghavi recommendations unified using vulnerable plaque to described allthe plaques which has dangerous, this species plaque often has thin fiber cap, large fatmass core, inflammatory cell active, etc. Belong to early plaque, caused cavity narrowonly low to moderate, vulnerable plaque’s rupture can led to platelet gathered andthrombosis formed, became the main causes of acute crown pulse integrated syndromeand coronary heart disease sudden death. Experimental and clinical studies are the basisbe early evidence of atherosclerotic plaques by timely intervention can bereversed.Therefore, clinical need to look for a quick, simple and non-invasive imagingmethod to detecting early plaque.Current clinical atherosclerotic plaques in the main method for evaluation:intravascular Ultrasound (IVUS), DSA, optical coherence tomography (OCT),multislice CT (MSCT), MRI, etc, but the frontal three methods are invasive inspection,and expensive, not as a regular checks;MRI examination resolution of soft tissue, butcheck for a long time, for very sensitive motion artifacts, experimental results can notobtain satisfactory results.MSCT angiography is a noninvasive examination, because ofits fast, efficient, affordable, convenient and can be repeated etc. so become importantways of atherosclerotic plaque in current research.Diagnosis of atherosclerosis inpatients with advanced disease had been recognized, but there is not much research onearly plaque.In the study selection based on pathology and pathological physiology andhuman atherosclerotic plaques as an experimental animal model in rabbits with certainsimilarities, comparative the pathology, objective evaluation of128-slice spiral CTangiography characteristics, assess their ability to determine early atherosclerotic plaqueand limitations. The first partMaking the model of atherosclerotic plaquePurpose The rabbit atherosclerosis model is established by the high fat diet,discussion on simple, easy, and effective methods of animal experimental modelmaking,and by the pathological anatomy of animal models to validation and reliability.Materials and methods54healthy New Zealand White rabbits,randomly into fourgroups,after12-weeks the model success,respectively20rabbits in control group,26rabbits in the experimental group A (simple high-fat diets),2rabbits in theexperimental group B (high fat diet+melatonin intervention),2rabbits in theexperimental group C（high fat diet+rosuvastatin）.All the rabbits has been executedafter checking the MSCTA, isolation and remove the aorta, first observation of aorticwall with eyes, after the digital camera photography, segmented into pathologicalobservation.Experimental group A+B+C as experimental group。 use X2toanalysis,inventory experimental group and control group with plaques andplaque-free,then inventory experimental group A、 B and C with plaques andplaque-free,work with SPSS19.0software.Result (1)There are total150cross section of all pathological,in group A there are80/90layer slice of animal found in plaque,control groups have been unable to findplaques.Statistical analysis showed that the experimental group and the control grouphad significant differences (P<0.05).(2)The aortic of control group are soft andflexible,the intima of the lumen is smooth.Aortic wall significantly increased clearlythickness, stiffness, visible white stripe-shaped uplift in group A(Experimental groupB and C number of plaque and tube wall thickness is not as clear as group A).Conclusion (1)Fed New Zealand White rabbits by high-fat diet to establishmentatherosclerotic model is viable,supply a reliable platform for the follow-up research of earlier plaque imaging performance; Pairwise comparison the experimental group A, group B,and the group C, plaque formation probability, P <0.001, statistically significantdifference.(2)melatonin and Rosuvastatin has the function to anti-atherosclerosis plaqueThe second partAtherosclerosis early plaques in the performance of MSCTangiographyPurpose Investigate the diagnostic value and limitations of the128-slice spiral CTangiography for the early atherosclerotic rabbit arterial plaque.Method Follow the first part of the production of the experimental group2(46)rabbit atherosclerotic model (control group20, high-fat diet group26),separately take64-row128-slice spiral CT angiography,Comparison of pathological anatomy, summedup the performance of early plaque of atherosclerosis;at the same time select thevascular cross-sectional images of the two high-fat group rabbits to adjust the windowwidth and window level,record the number of the level which observed in plaque,all thedata treat with the SPSS19.0package,test with x2Respectively to different windowwidth, window level observations of early plaque analyzed the provisions of p <0.05statistically significant.Result （1）The20normal feeding rabbit blood vessels is regularly, CTA showed noabnormal。（2）rabbit blood vessels of six high-fat diet in the general concept of intimalsurface covered with fatty streaks and plaque,analysis corresponds to the vascularcross-sectional images of the78biopsy,there are75layer (96.2%), vascularcross-section of aorta loss of normal smooth form,even polygonal,the brightcontrastively in the middle is filling of the lumen around the fuzzy irregular "halation"of the aortic wall around,within the lumen, and wherein the eccentric thickening36 layer (46.2%) in the lumen with irregular fashion visible wall and a small filling defectconvex,All rabbit lumen were no significant stenosis（.3）Respectively the WW and WLis （200HU,200HU）、（250HU,200HU）、（300HU，200HU）、（350HU,200HU）、（400HU,200HU）、（450HU,200HU）、（500HU,200HU）、（550HU，200HU），（600HU,650HU）,there are differences in the rate of early plaque，but respectively Groupsobservation w w and wl respectively (200HU,200HU),(250HU,200HU) display the probability ofearly plaque little difference,there was no statistically significant.Groups observation w w and wlrespectively (200HU,200HU),(250HU,200HU) display the probability of early plaque littledifference,there was no statistically significant.As the WW increases,gradual decline in its rate ofplaqueConclusion64rows of128-slice spiral CT angiography is an important means tostudy the atherosclerotic plaque,it can be early detection of atherosclerosis, for earlypharmacological intervention,has an important significance in the pathological processof the reversal of plaque.Its atherosclerosis early vascular changes in the cross-sectionalimage shows best, The main performance is the morphological changes of thearteries,lumen lose the smooth shape,part of the performance is a small filling defect;thecorrect window width, window level is very important for display rate,As the WWincreases,gradual decline in its rate of plaque.narrow window is more conducive to early plaque todisplay and observe the vascular changes.; but it also has certain limitations.

        64排128层CT血管造影评价动脉粥样硬化早期斑块的实验研究

英文缩略词表5-6中文摘要6-10Abstract10-14第一部分 动脉粥样硬化斑块模型的制作15-29    1 前言15    2 材料与方法15-16    3 结果16-23    4 讨论23-27    5 结论27    6 参考文献27-29第二部分 动脉粥样硬化早期斑块在MSCT血管造影的表现29-50    1 前言29-30    2 材料与方法30-32    3 结果32-42    4 讨论42-48    5 结论48    6 参考文献48-50附录50-51致谢51-52综述 MSCT血管造影评估冠状动脉易损斑块的特征52-62    参考文献59-62

  本文关键词：64排128层CT血管造影评价动脉粥样硬化早期斑块的实验研究，由笔耕文化传播整理发布。