| 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. |
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