Quantitative Ultrasonic Integrated Backscatter On Carotid Atherosclerosis Of Middle-aged And Youth With Hyperlipemia

Atherosclerosis (AS) is a generalized arterial disease that can implicateall the organic artery blood vessels of the whole body, make the change ofheart and brain important organ's construct and function, lead to all kindsserious consequences(myocardial infarction, cerebral apoplexy et al). In ourcountury, the morbidity and mortality rate of cardiovascular andcerebrovascular diseases induced by AS is increasing, and had becomed themain reason of causing disability and lethal. With the raising of people's livingstandard and the change of the live style and the dietary structure,hyperlipemia is increasing gradually, the morbidity age of cardiovascular andcerbrovascular disease is tend to juvenility, as a result, to early finding, preventand control the generation and progress of AS is one of the clinical significanttask presently. In our study, we used the Integrate Backscatter (IBS) techniqueto systemic detection the carotid artery in the middle-age and youthhyperlipemia patients in multiregion and multipoint, aimed to provide areliable and objective basis for quantitiving the early AS, which can detect theearly AS with new ,noninvasive and convenient merits.High-frequency ultrasound can clear display the surface large artery,especially to carotid artery wall, many studies have proved the increase ofcarotid intima-media thickness (IMT) is a sensitivity index to reflection theearly AS , previously. Which have intimate correlation to coronary heartdisease (CHD) and cerebral apoplexy risk factors. But because the IMTmeasurement methods have not standardized and the numerical value of IMTare not identity in all kinds document reports. When the compensation vesselreconstruction, the change of IMT is not easy to distinction, and the IMT cannot reflect the change of the pathological property in early AS period, so thedetection of IMT restrict the clinical diagnosis on cardiovascular andcerebrovascular disease. Thus need us to find a new method, which candescribe the pathological histologic changes on the vessel wall accurately.Another name of IBS technology is ultrasonic tissue characterization.This has developing in recent years can detect the radio frequency signal,which emits by the minim particle whose diameter is less than the wavelength.Using this technique can reality reflect the tissue's structural information andthe acoustical characterize. Many scholar both here and abroad have repartedmuch of articles which evaluated myocardial ischemia and myocardialinfarction aspects using this technology, in the aspect of evaluating thepathology tissue property of the plaque have a little reports in recent years.Whereas using IBS technology to evaluate the change of the structure andfunction in the artery vessel is extremely little outside, not yet inside.Especially the study on the change of early AS in carotid wall of middle-ageand youth hyperlipemia patient has not yet reported both here and abroad.Our study applied with the SONOS HP5500 color ultrasonic diagnosismachine; thirty-one normal controls were compared to fifty-eight middle-ageand youth hyperlipemias, using calibrated IBS (C-IBS, C-IBS=intima-mediaIBS-adventitia IBS) to detect the carotid intima-media. Associating with thetwo-dimension ultrasound to detect the IMT, artery physicalparameter(stiffness β,carotid distensibility, carotid conformability) andbrachial artery endothelium-dependent dilation(EDD).The findings showed that the C-IBS in hyperlipemia group were lowerthan that of normal control, there was no significant difference between bothgroups, but significance different between both groups at bifurcate and internalcarotid artery (ICA)(P<0.05), although the C-IBS of common carotidartery(CCA) in hyperlipemia group was lower than that of normal control, butno significance different(P>0.05). Due to the lower shear stress and the longerlipid resistance time in hemodynamics and pathology aspect's reason,AS hasbeen befallen at carotid bifurcate and enlargement part. In our study, we findin the different section of carotid, from CCA, bifurcate to ICA, C-IBSdecreased gradually; Between CCA and ICA there is significance differentinside each group(P<0.05); But in hyperlipemia group between ICA andbifurcate, bifurcate and CCA have distinct different and significance(P<0.05),reversing in normal controls(P>0.05). Using C-IBS<-18.3dB as a cutoff value,the diagnostic sensitivity,specificity,accuracy of hyperlipemia were 77%,60% and 66% respectively. IBS technology can evaluate the AS degreeaccuracy and can true judge the change of vessel wall which aroused by lipiddeposition. Using this can provide a early AS index for clinic. The state of artery endothelium funtion is one of the cardiovascular andcerebrovascular disease's important markers. Our study finds that inhyperlipemia group the endothelium-dependent dilation (EDD) was lowerobviously than that of normal control (P<0.05), and correlated positive withC-IBS value, but the IMT value has no evidence change between the twogroups. AS is a disease that the artery function lesion and artery wallpathology transform concurrent, and at early AS period, the pathologytransform and function lesion have happened and before the texture abnormity. Stiffnessβ,carotid conformability(CC) and carotid distensibility(CD) arethe carotid physical state index, and have osculating correlation. EDD lesion is...