Assessment Of Arterial Intima-media Characteristics In Human Carotid Arteries Using Integ Rated Backscatter Ultrasound

Atherosclerosis (AS) is a generalized arterial disease that canimplicate all the organic artery blood vessels of the whole body, makethe change of heart and brain important organ's construct and function,lead to all kinds serious consequences (myocardial infarction, cerebralapoplexy et al). In current, the morbidity and mortality rate ofcardiovascular and cerebrovascular diseases induced by AS isincreasing, and had becomed the main reason of causing disability andlethal. With the raising of people's living standard and the change ofthe live style and the dietary structure, the morbidity age ofcardiovascular and cerbrovascular disease is tend to juvenility, underthis situation, to discover, prevent and control the generation andprogress of AS in an early stage is one of the clinical significant taskpresently. Therefore, a practical and accurate method, which candiagnose AS in advance, is needed. In our study, we used the IntegrateBackscatter (IBS) technique to systemic detection the carotid arteriesin 200 normal subjects who took routine physical examination in P.E.center of our hospital. In present study, we divided these subjects intofive groups according to 10-year intervention. By multi-region andmultipoint detection of the carotid arteries, we obtained the originaldata of IBS, IMT and EDD% values. After statistical analysis to thesedata, we provide a reliable and objective quantities basis for referenceto the standard diagnosing in early AS, which detects the AS with new,noninvasive and convenient merits.Integrated Backscattered technique is a newly developedultrasonic diagnosing method, which is superior in differentiating thetissue characteristics. IBS can distinguish the normal and pathologicaltissue through detecting the sonic parameters of different tissue.Another name of IBS technology is ultrasonic tissue characterization.This has developing in recent years can detect the radio frequencysignal, which emits by the minim particle whose diameter is less thanthe wavelength. Using this technique can reality reflect the tissue'sstructural information and the acoustical characterize. Many scholarsboth here and abroad have reported much of articles which evaluatedmyocardial ischemia and myocardial infarction aspects using thistechnology, in the aspect of evaluating the pathology tissue property ofthe plaque have a little reports in recent years. Whereas using IBStechnology to evaluate the change of the structure and function in theartery vessel is extremely little outside, not yet inside;High-frequencyultrasound can clear display the surface large artery, especially tocarotid artery wall, many studies have proved the increase of carotidintima-media thickness (IMT) is a sensitivity index to reflection theearly AS, previously. Which have intimate correlation to coronaryheart disease (CHD) and cerebral apoplexy risk factors. But becausethe IMT measurement methods have not standardized and thenumerical value of IMT are not identity in all kinds document reports.When the compensation vessel reconstruction, the change of IMT isnot easy to distinction, and the IMT can not reflect the change of thepathological property in early AS period, therefore the detection ofIMT restrict the clinical diagnosis on cardiovascular andcerebrovascular disease. Thus need us to find a new method, whichcan describe the pathological histological changes on the vessel wallaccurately;the artery characteristic parameter like stiffnessβand EDDare the diligent indicator for AS. The abnormal changes in stiffnessβand EDD sometimes are presented earlier than IMT and IBS, thereforedetect these indicators can make a better diagnose for early stage AS.However, single indicator will not cover the whole aspects of as andsometimes is weak in diagnosing. When we combine these indicators,the evidence for us to make a accurate diagnose is strong, and theresults are much more convincing.Our study applied with the SONOS HP5500 color ultrasonicdiagnosis machine;200 normal controls were applied and divided intofive groups with intervention of 10 years. Using calibrated IBS(C-IBS, C-IBS=intima-media IBS-adventitia IBS) to detect the carotidintima-media. Associating with the two-dimension ultrasound todetect the IMT, artery physical parameter (stiffness β ,carotiddistensibility, carotid conformability) and brachial arteryendothelium-dependent dilation (EDD).We find out that C-IBS, IMT and stiffness β increase inaccordance with the age increasing, EDD decrease when age increase.The normal value of different groups are as following: C-IBS (dB):Gro1: -17.76±4.12, Gro 2: -17.62±4.40, Gro 3: -16.29±4.00, Gro 4:-14.96±4.47, Gro 5: -14.49±4.45. IMT: Gro 1: 0.44±0.08mm, Gro 2:0.47±0.08mm, Gro 3: 0.53±0.07mm, Gro 4: 0.59±0.07mm, Gro 5:0.66±0.09mm. EDD%: Gro 1: 15.12±3.31, Gro 2: 13.86±2.84, Gro 3:11.60±2.18, Gro 4: 10.78±2.20, Gro 5: 9.61±2.60.The C-IBS value in different groups follow the rule:inner-carotid0.05). IBS technology can evaluate the AS degree accuracy andcan 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 function is one of thecardiovascular and cerebrovascular disease's important markers. Ourstudy finds that in different groups the endothelium-dependent dilation(EDD) was decreasing obviously when the age increase (P<0.05), andcorrelated positive with C-IBS and IMT value. AS is a disease that theartery function lesion and artery wall pathology transform concurrent,and at early AS period, the pathology transform and function lesionhave happened and before the texture abnormity.Stiffnessβ,carotid conformability (CC) and carotid distensibility(CD) are the carotid physical state index, and have osculatingcorrelation. EDD lesion is one of the reasons of the depression ofcarotid conformability. Both here and abroad many studies havedisplayed that the change of artery wall structure was the main reasonof the depression of CC,CD, and was a independent risk factor andimportant pathology,physiological basis among the cardiovascularand cerebrovascular case. In our study, the CC,CD correlated positivewith C-IBS value (r=0.33, r=0.30 P<0.05);moreover, the stiffnessβdistinct increase and correlated negative. Applying with IBStechnology quantitative the transform of the pathology tissue propertyin the carotid intima-media is osculate correlation with the change ofthe artery wall physical state, reflecting the internal relation among thestiffnessβ,CC,CD and histology.Joint application IBS technology,IMT,EDD and artery physicalstate detection can accuracy and objective evaluate the risk degree ofearly AS among the middle-age and youth hyperlipemia patient. Thistechnology has noninvasive, so using it can provide an index of earlyAS, and can predict the happen of the cardiovascular andcerebrovascular case in early stages. IBS technology is provided withsafety,convenient,save the money and time et al merits, havingpracticability and worthiness in clinic.