Evaluation Of BFI Technique In The Diagnosis Of Atherosclerosis

Background and Objective:Atherosclerotic cardio-cerebral vascular diseases were the most severe hazards to people's health and life. These diseases usually result in many other diseases. Atherosclerotic plaque may make artery stenosis, and the instability of which was the most important factor to induce many clinic conditions. In the past years, it was thought atherosclerosis was a kind of vascular diseases resulting predominantly from the unbalance of lipid metabolizes and aggradations of lipid on the wall of blood vessel, however, in recent years more and more evidences indicate that atherosclerosis is also one kind of chronic inflammatory disease, and many inflammatory factors take part in the whole process of atherogenesis.The stability of atherosclerotic plaque is related closely to that whether a plaque ruptures or not, mainly depends on its composition, Therefore, it is very important and necessary to improve its stability. However, up to now, there is no effective drug for that. Panax notoginseng saponins (PNS) are the principal ingredients extracted from the traditional Chinese medicinal herb Panax notoginseng. It has been demonstrated that PNS have extensive effects on the cardiovascular system, such as modulation lipid metabolism, inhibition of platelet aggregation, increasing blood flow through the coronary arteries, improving left ventricular diastolic function in hypertensive patients, and an anti-inflammatory effect due to a reduction of intracellular free calcium levels in neutrophils, etc. And previous experiments in our laboratory have indicated that the inflammation induced formation of foam cells is inhibited following the administration of PNS.In recent years, vessel angiography was considered as the golden standard for AS diagnoses. However, the contrast agents only flow in blood vessel, and AS plaques and pathological changes of vessel are only showed as filling defect. Therefore, vessel angiography can not evaluate exact pathological changes of vessel. In addition, as a kind of invasive examination, angiography is quite complex and has various complications, which limit its application at a great extent. Although ultrasound technique is a simple and reliable method to evaluate the status of AS plaque, it has various disadvantages, such as the low resolution and sensitivity, high false positive rate, etc. Blood flow image (BFI) is a novel ultrasound technique. It can reserve the detail of the reflection of erythrocytes and get more homogeneous information to distinguish the ture blood flow and the motion artifact of vessel wall. Therefore, this study was designed to evaluate the effects of PNS on the stability of atherosclerotic plaque in rabbits with BFI technique by comparsion of traditional pathological and ultrasound methods.Methods:Rabbits were divided randomly into four groups: group A (contral group, n=24), group B (AS group, fed with hypercholestermia diet only, n=24), group C( inflammation group, fed with hypercholestermia diet and administrated ip with zymosan A10mg/kg, Om.bid, n=24); group D(PNS groups, fed with hypercholestermia diet, administrated ip with zymosan A10mg/kg, Om.bid and PNS 45mg/kg, ig, once daily, n=12). The initial-medial thickness (IMT) of abdominal aortic posterior wall and plaque in group A,B and C were measured with ultrasound technique after 0, 4, 8, 12 weeks'feeding. The sensitivity of diagnosing AS was observed though BFI technique in group D. The IMT,RI and the formulation of plaques were observed before and 12 weeks after treatment. The level of blood lipid was detected with enzymic methods. The expression of PCNA in plaque, CRP mRNA and MMP-2 mRNA in the artery wall were determined with immunohistochemistry and RT-PCR technique, respectively. The evaluation efficiency of BFI technique is assessed by comparing with ordinary US and pathological examination.Results1. Zymosan A (10mg/kg, Om.bid) increased the expression of CRP-mRNA and MMP-2 mRNA in the wall of artery in rabbits during atherogenesis significantly.2. Ultrasound results show that the thickness of initial-medial in inflammation group was thicker than that in AS group. The number of plaque in inflammation group was more than that in AS group, and the stability of plaque in inflammation group was thinner compared with AS group.3. Ultrasound results show that PNS could decrease the thickness of initial-medial and the number of plaque mardedly compared with inflammation group.4. BFI technique was superior to the ordinary ultrasound in evaluating the pathological changes of AS, which was highly consistent with digital subtraction angiography.Conclusions:1. BFI technique is superior to the ordinary B ultrasound and color doppler flow imaging in the diagnosis of AS with higher sensitivity and accuracy, which is sutible for the continuous and dynamic observation of AS.2. BFI technique can be used to observe the process and therapeutic effects of AS in animal experiments contiluously and noninvasively.3. BFI technique provide a more economical, sensitivity, convenient and noninvasive method for the early diagnosis of AS for clinical patients...