本文關(guān)鍵詞：64排128層CT血管造影評價動脈粥樣硬化早期斑塊的實驗研究，由筆耕文化傳播整理發(fā)布。

        背景近年來，隨著人們生活水平的提高，冠心病的發(fā)病率逐年增加，已經(jīng)成為發(fā)達國家嚴重危害人們健康的主要疾病之一。美國心臟病學會(American HeartAssociation,AHA)的2002年統(tǒng)計資料顯示，心血管疾病占全美總死亡的40.1%，其中冠心病死亡占心血管疾病死亡的55%。在我國，冠心病的患病率和死亡率也有逐年增加趨勢。據(jù)流行病學資料統(tǒng)計，20世紀50年代末，冠心病在北京和上海40歲以上人群中的患病率為2.45%和3.18%；20世紀70年代全國22個省市的調(diào)查顯示，冠心病的患病率上升為6.46%；北京地區(qū)調(diào)查顯示，冠心病的病死率1976年為21.7/10萬人，1988年為88/10萬人，1992年為96/10萬人，近年來仍在不斷上升。因此，冠心病已成為嚴重威脅人類健康的疾病，在我國也迅速成為頭號殺手，其導致醫(yī)療費用的消耗也極大增加了家庭和社會的負擔。冠心病的基礎(chǔ)病變是動脈粥樣硬化（AS）。動脈粥樣硬化是累及體循環(huán)系統(tǒng)的從大型肌彈力型（如主動脈）到中型肌彈力型（如冠狀動脈）動脈內(nèi)膜的疾病。其特征的病變是從動脈內(nèi)膜開始，先后有脂質(zhì)和復合糖類積聚、出現(xiàn)和血栓形成、纖維組織增生和鈣質(zhì)沉著，并有動脈中層的逐漸退變和鈣化。2003年Naghavi建議統(tǒng)一使用易損斑塊(vulnerable plaque）來形容所有有危險的斑塊，此種斑塊常具有纖維帽較薄，脂質(zhì)核心大，炎性細胞活躍等特點，屬于早期斑塊，引起管腔狹窄僅為輕-中度，易損斑塊的破裂可導致血小板聚集和血栓形成，成為急性冠脈綜合征和冠心病猝死的主要原因�；A(chǔ)實驗和臨床研究也均得到了早期動脈粥樣硬化斑塊通過及時干預可以逆轉(zhuǎn)的證據(jù)。所以，臨床急需尋找一種快捷、簡便、無創(chuàng)的影像學方法探查早期斑塊。目前臨床用于評價粥樣硬化斑塊的主要方法有：血管內(nèi)超聲(IVUS)、DSA、光學相干斷層成像(OCT)、多層螺旋CT (MSCT)、MRI等，但前三種方法均為有創(chuàng)性檢查、且價格昂貴，不宜作為常規(guī)檢查；MRI檢查雖然軟組織分辨率高，但檢查時間長，對于運動偽影極為敏感，因此實驗結(jié)果無法取得滿意效果。多層螺旋CT血管造影屬無創(chuàng)性檢查，因其快捷、高效、價格適中、方便、可反復進行等成為目前研究動脈粥樣硬化斑塊的重要手段。它對于動脈粥樣硬化中晚期病變的診斷價值已得到公認，但是對于早期斑塊的研究目前仍不多。本研究選擇基礎(chǔ)病理學和病理生理學上與人動脈粥樣硬化斑塊具有一定相似性的兔作為實驗動物模型，對比病理檢查，以期客觀評價128層螺旋CT血管造影的特點，評估其判斷早期動脈粥樣硬化斑塊的能力及局限性。第一部分動脈粥樣硬化斑塊模型的制作目的通過高脂飲食建立兔的動脈粥樣硬化模型，探討簡便、易行、有效的動物實驗?zāi)Ｐ椭谱鞣椒�，并通過病理解剖驗證動物模型的可靠性。材料與方法54只健康新西蘭大白兔，隨機分為四組，12周后建模成功，分別為對照組20只，實驗組A（單純高脂飲食）26只，實驗組B（高脂飲食+褪黑素干預）2只，實驗組C（高脂飲食+瑞舒伐他�。�2只。所有兔在MSCTA檢查后處死,分離取出主動脈，先肉眼觀察主動脈內(nèi)壁，行數(shù)碼相機攝影后，分段制成病理切片觀察。實驗組A+實驗組B+實驗組C定為實驗組。采用x2分析及確切概率法，分別清點實驗組和對照組有斑塊段數(shù)和無斑塊段數(shù)，以及實驗組A、實驗組B及實驗組C有斑塊的血管段數(shù)和無斑塊的血管段數(shù)。所有數(shù)據(jù)采用SPSS19.0軟件進行。結(jié)果（1）全部橫斷面病理切片共150層，其中實驗組動物的90層切片中發(fā)現(xiàn)斑塊80層，對照組中均未發(fā)現(xiàn)斑塊，統(tǒng)計分析表明實驗組與對照組具有明顯差異(P<0.001)，差別有統(tǒng)計學意義；兩兩對比實驗組A、實驗組B和實驗組C的斑塊形成概率，，P<0.001，差別有統(tǒng)計學意義。（2）對照組主動脈柔軟有彈性，管腔內(nèi)膜光滑；實驗組主動脈管壁明顯增厚、僵硬，可見白色條紋狀隆起（實驗組B及C的斑塊數(shù)量和管壁厚度均不如實驗組A明顯）。結(jié)論（1）通過高脂飲食法喂養(yǎng)新西蘭大白兔建立動脈粥樣硬化模型是可行的，為后續(xù)進一步研究早期斑塊的影像學表現(xiàn)提高可靠的平臺。（2）褪黑素和瑞舒伐他汀具有抗動脈粥樣硬化斑塊的作用。第二部分動脈粥樣硬化早期斑塊在MSCT血管造影的表現(xiàn)目的探討128層螺旋CT血管造影對于兔動脈粥樣硬化早期斑塊的診斷價值及其局限性。方法沿用實驗第一部分制作完成的2組（46只）兔動脈粥樣硬化模型（對照組20只，高脂飲食組26只），分別行64排128層螺旋CT血管造影檢查，對比病理解剖，總結(jié)動脈粥樣硬化早期斑塊的表現(xiàn)；同時隨機選取2只高脂組兔的所有血管橫斷面圖像進行窗寬、窗位的調(diào)節(jié)，分別記錄觀察到斑塊的層面數(shù)，并對比大體解剖，所有數(shù)據(jù)采用SPSS19.0軟件包處理，利用x2檢驗及確切概率法,分析不同窗寬、窗位觀察下早期斑塊的顯示概率，規(guī)定p<0.05有統(tǒng)計學意義。結(jié)果（1）20只正常飼養(yǎng)兔血管正常，CTA未見明顯異常。（2）26只高脂飲食兔的血管大體觀內(nèi)膜表面均布滿脂紋及脂斑，分析對應(yīng)于78張病理切片的血管橫斷面圖像，有75層（96.2%）血管斷面顯示主動脈失去正常的圓滑形態(tài)，甚至呈多邊形，中間明亮的對比劑充盈的管腔被周圍模糊樣不規(guī)則“光暈”即主動脈壁環(huán)繞，且其中36層（46.2%）在管腔不規(guī)則的同時尚可見管壁偏心性增厚及小充盈缺損凸向管腔內(nèi)。所有兔血管腔均未見明顯狹窄。（3）窗寬、窗位為（200HU,200HU）、（250HU,200HU）、（300HU,200HU）、（350HU,200HU）、（400HU,200HU）、（450HU,200HU）、（500HU,200HU）、（550HU,200HU），（600HU,200HU）時對早期斑塊的顯示概率的差別有統(tǒng)計學意義；而組間觀察窗寬、窗位分別為（200HU,200HU）、（250HU,200HU）時對早期斑塊的顯示概率的差別不大，差別沒有統(tǒng)計學意義，隨著窗寬的增加，其對于斑塊的顯示率逐漸下降。結(jié)論64排128層螺旋CT血管造影是研究動脈粥樣硬化斑塊的一種重要手段，它可以早期發(fā)現(xiàn)動脈粥樣硬化，對于早期進行藥物干預，逆轉(zhuǎn)斑塊的病理進程有著重要意義。它對動脈粥樣硬化早期血管的改變以橫斷面圖像顯示率最高，主要表現(xiàn)為動脈管腔形態(tài)的改變，管腔失去圓滑形態(tài)，部分表現(xiàn)為小充盈缺損；正確的窗寬、窗位對于顯示率很重要，窄窗更有利于早期斑塊的顯示及觀察血管改變；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層CT血管造影評價動脈粥樣硬化早期斑塊的實驗研究

英文縮略詞表5-6中文摘要6-10Abstract10-14第一部分 動脈粥樣硬化斑塊模型的制作15-29    1 前言15    2 材料與方法15-16    3 結(jié)果16-23    4 討論23-27    5 結(jié)論27    6 參考文獻27-29第二部分 動脈粥樣硬化早期斑塊在MSCT血管造影的表現(xiàn)29-50    1 前言29-30    2 材料與方法30-32    3 結(jié)果32-42    4 討論42-48    5 結(jié)論48    6 參考文獻48-50附錄50-51致謝51-52綜述 MSCT血管造影評估冠狀動脈易損斑塊的特征52-62    參考文獻59-62

  本文關(guān)鍵詞：64排128層CT血管造影評價動脈粥樣硬化早期斑塊的實驗研究，由筆耕文化傳播整理發(fā)布。