Application Of Contrast-enhanced Ultrasonography In Evaluation Of Carotid Atherosclerotic Plaque Stability

Heart, cerebrovascular accidents are one of the highest disease of the morbidity and mortality.Atherosclerosis is the most important pathology base and risk factors of heart and cerebrovascular accidents. Research proves that acute heart and cerebrovascular accident appear by unstable atherosclerotic plaque or vulnerable plaques cracked into blood clots Undoubtedly that vulnerable plaques of carotid atherosclerosis is the most important reason leading to ischemic heart and cerebrovascular accidents and the main pathogeny of ischemic stroke. Stroke is the primary factor in old peoples'permanent loss of life independently and the main cause of death.So, it's particularly important to research the stability of carotid atherosclerotic plaques.Main features of unstable vulnerable plaques is that newborn angioge-nesis in atherosclerotic plaque.There are rich nourishing blood vessels around atherosclerotic plaque. They can make atherosclerotic plaque progressive aggravating. Even though the plaques are under the fibrous cap, lipid still accumulates in plaques. The new blood vessels in patches are the significant cause of bleeding in the patch. In addition, new blood vessels let the inflammatory cells into the patch, Cytokines produced by it can activate macrophages and smooth muscle cells to produce matrix metalloproteinases, which can degrade matrix, weaken plaques fibrous cap and also cause plaques to be unstable and fragile. New blood vessels in patches are one of the most important reasons of bleeding intraplaque.So, it is particularly important to detect the existence and grow of new capillaries inside atherosclerotic plaque The basis of contrast-enhanced ultrasonography (CEUS) technique has higher space and time resolution. Ultrasound such as SonoVue can produces tiny bubbles intravascular red blood cells, which has the characteristics of blood kinetics. So it can be used as a vascular tracer. Because the ultrasound can only arrive contrast plaques organization testing by capillary, the enhancement contrast in plaques is the formation of vascularization. It can effectively evaluate patches vessels density.Research proves that CEUS can enhance the contrast resolution between lumen and endometrial, and improve the measurement accuracy between the near wall and far wall IMT.It enhances the imaging ability of hemal walls, displaying the outer membrane nourish blood vessels and patching new blood vessels of atherosclerotic vascular, such as ulcer or plaques.One can evaluate the correlation between the enhancement degree of plaques and distribution density in new blood vessels by CEUS, and this correlation is quantification and controlled. The quantitative analysis of it is one of research topic in plaques stability. The CEUS can observe the supply of blood perfusion by organization in real time. It is a simple, non-inasie screening method that evaluates the stability of atherosclerotic plaque.So, this research of the detection of carotid atherosclerotic plaque inside vessels blood perfusion analysising patches vessels density can enhance the relationship with clinical symptoms and evaluate comprehensive plaques of stability.This study chose the outpatient and inpatient who has the carotid atherosclerotic plaque, including 32 male and 28 female, aging from 42 to 76(average 65±9), The thickness of patch>2.0cm,60 patients with 67 plaques for contrast-enhanced ultrasonography analysis. First according to the standards of Salcuni, with the thickness of inner-middle> 1.2cm. Choose them according with standard into the research object According to carotid atheromatous plaques in two-dimensional image and the classification standard patch into three groups:(1) soft spot, (2) mixed spot, (3) hard spot. There are soft spot 32, hard spot 20, calcified plaque 13 mixed spot 7 in 67 plaques.Ultrasonic imaging:real-time ultrasound imaging with startup imaging mode, contrast agent from Braacco from Italy, needs sodium chloride injection diluted 5ml·sterile. After each fully oscillation, push 2.4 ml in the former vein elbow.After the routine ultrasound examination, fix the probe position, let the patient breathe slowly, start the imaging software, and observe the whole process of ultrasonic imaging until the imaging micro bubble disappear. Use the DICOM format and save the traditional ultrasound images and imaging process of dynamic imaging material.According to in the distribution, contrast patch characteristics of the image after contrast-enhanced ultrasonography, patches vessels situation is divided into four levels:I grade,no enhancing in plaques;Ⅱgrade, star blob-shaped enhance or local small range enhance in plaques;Ⅲgrade, patch and short strip enhance in plaques;Ⅳgrade, Strip and the network-like enhancement in plaques. By the observation patches contrast enhancement, for different patches contrast-enhanced sonography of new blood vessels for classification result: I grade,3 soft spot,4 mixed grade,15 hard spot;Ⅱgrade,12 soft spot5 mixed grade,4 hard spot;Ⅲgrade,13 soft spot,5 mixed grade,1 hard spot;Ⅳgrade,4 soft spot,1 mixed grade,0 hard spot.Quantitative analysis about carotid atherosclerotic plaques after radiography with Sonoliver CAP software will analyze according to time strength curve with maximum intensity, time to peak, area under curve to infinite time under the parameters.We evaluating different plaques after complete observation and quantitative analyze about distribution density enhancement and enhance the degree in newborn angiogenesis,degree of different plaques thorough observation.Analysis Results:to the carotid within the lumen lmax is 100, soft plaques means (-85.04±7.82)%. Soft spot new blood vessels classification are higher than other types of patches The maximum peak intensity of soft spots are significantly higher than other types of patches. The 1max of soft plaques and mixed plaques(P<0.01),1max of soft plaques and hard plaques(P<0.01), there are significant differences. The time to peak, mean transit time is obviously lower than other types of patches. Soft spot and mixed spot TTP (P< 0.05) are statistically significantly different in soft spot with hard spot. TTP (P <0.01) have significant differences. Soft spot and mixed spot determined by mTT (P< 0.05) are statistically significant differences in soft spot with hard spot determined by mTT (P< 0.01) have significant differences.Research shows that soft spots contrast tiny bubbles perfusion within significantly increased, enhanced obviously, that blood flow signals of new blood vessels in soft spot is more abundant than other forms patches new blood vessels. But the signs are mixed spot blood part or moderate degree, show that the hybrid enhanced in the growth of new blood vessels spots as soft spot, but rich in new blood vessels There is t no or little blood in hard spot, is not clear signal strengthen blood vessel growth.The healing of ruptured blood vessels on the surface of plaques and the emergence of new blood vessels are the main cause of rapid progress patch. Because patchs new blood vessels are surrounded by simple endothelial cells around the pipeline, the lack of connective tissue and basement membrane support, the blood vessels of the larger, easy to burst bleeds brittle, enabling their serious clinical symptoms. New blood vessels quantity and density in plaques is correlated with clinical symptoms. There are higher the risk in the more density in vascularization. All these prove that comparing with mixed spot hard spot, the soft spot of new blood vessels that is more rich, instability, easier to burst, the highest sparked, so can cause more serious cerebrovascular accident.Research shows that the new blood essels in atherosclerotic plaque is one of most important features to identify patch stability, Using SonoVue as ultrasound, can produce tiny bubbles which have blood kinetics of intravascular red blood cells. It can be as vascular tracer. Ultrasound imaging techniques can noninvasively test the new blood vessels in carotid atheros-clerotic plaques,noninvasive evaluation of carotid atherosclerotic plaques stability have important clinical impact.Conclusion1,Contrast-enhanced ultrasonography technique has high time and space resolution. It can quantitatively analysis about atherosclerotic plaque.2,Contrast-enhanced ultrasonography can real-time track the artery and display the situation of carotid atherosclerotic plaques within new blood vessels.3,This research shows that the formation and development of atherosclerosis is strongly related with newborn angiogenesis4,Quantitative noninvasive evaluation about the stability of plaques according to the contrast enhancement situation of plaques of vulnerability assessment.