Clinical Value Of Carotid Artery Ultrasound Combined With Transcranial Doppler Ultrasound In Patients With Ischemic Stroke

Background:Ischemic stroke is a great threat to people’s health and life safety due to its high morbidity and mortality. The primary cause of the disease is atherosclerosis. Lesions and narrow of intracranial vascular and vulnerable plaque are the main causes of stroke. There is a strong relationship between the degree of atherosclerosis and stroke. Artery stenosis causes hypoperfusion of cerebral blood flow upper the stenosis, and the blood vessels supplying the brain corresponding parts lack of oxygen, then brain tissue necrosis occurs. The sudden breakage of vulnerable plaque follwed by stimulate platelet,generate acute thrombosis leading to brain ischemia and hypoxia,then cerebral infarction occurs. Nowadays,the key role of the sudden breakage of vulnerable plaque in the pathogenesis of stroke has been gradually recognized.Carotid ultrasound and transcranial Doppler ultrasound have become the important choice for the screening examination of cerebrovascular disease because of non-invasiveness, non-radiation, safety and inexpensiveness. Past studies suggest that carotid ultrasonography can objectively valid diagnose the extent, location, area and scope of cervical vascular disease,TCD can effectively evaluate the severity of intracranial vascular lesions and diagnose vascular stenosis, and also recognizes its value. Carotid ultrasound combined with TCD can identify the atherosclerosis and detect vulnerable plaques earlierly, which is good for effective prevention and intervention of stroke,has great clinical value. The combination of these two ultrasound technology, theoretically provides a more comprehensive reference.So we did this study.Objective:To investigate clinical features of patients with ischemic stroke using carotid artery ultrasound,evaluate the relationship between the performance of ultrasound images and plaque vulnerability and explore the relationship among carotid artery stenosis,vulnerable plaque and stroke. On this basis, combined with transcranial Doppler ultrasound findings, we evaluate the clinical value of carotid ultrasound associated with transcranial Doppler ultrasound in the diagnosis of ischemic stroke.Methods:From April 2013 to April 2014,300 patients diagnosed with ischemic stroke by CT or MRI was divided into observation group,while 280 patients with the symptom of "dizziness, headaches" exclued from ischemic stroke were divided into control group.Patients in both groups were examined by the carotid ultrasound combined with TCD.Digital subtraction angiography(DSA) was used in the observation group as a control.The incidence of carotid stenosis and plaques, ultrasonic imaging characteristics and results of TCD were analyzed between the two groups.Results:The incidence rates of the patients with hypertension, coronary heart disease, or diabetes were higher in observation group,also for smoking and alcoholism.Incidence of intima thickening of the observation group was significantly higher than control group. Among these 300 cases of observation group,plaque detection rate was 75%,while in the control group,plaque detection rate is 33%. Incidence of plaque in the case group was significantly higher.Plaques of the two group were located in the area of the internal carotid and carotid artery enlargement.Plaque of observation group was mostly with irregular morphology and hypoechoic echo and hybrid echo.Calcification incidence between the two groups had no statistical difference. Further features of the plaques in ischemic and non-ischemic side of observation group was analyzed.Plaque in cerebral ischemia side(90 cases) showed irregular shapes, formation of ulcers ulcer and homogeneous hypoechoic and hyperechoic echo which was statistically significant with non-ischemia side(P<0.001), there was no significant difference in the incidence of calcification. Plaque of non-ischemic side of brain(74 cases) showed regular shapes, less formation of plaque ulceration,hyperechoic, and other heterogeneous echo,the difference was statistically significant(P <0.001), there was no significant difference in the incidence of calcification. Patients with carotid artery stenosis( 125 cases) was significantly higher in observation group. Transcranial Doppler displayed that incidence of intracranial stenosis(164 cases) of observation group was significantly higher than the control group.The incidence of stenosis of intracranial artery was greater than carotid artery.Combined with TCD,221 cases were found with stenosis, DSA detected a total of 219 cases with stenosis, including 123 cases of carotid artery stenosis, 170 cases of intracranial arterial stenosis. Sensitivity,specificity, positive predictive value, and negative predictive values using TCD combined with carotid ultrasound, were higher than carotid ultrasound or TCD testing. Carotid ultrasound combined with TCD could systematically evaluate the vascular disease and diagnose ischemic stroke accurately.Conclusions:1.The high-frequency ultrasound can not only make early diagnosis for internal membrane thickening,but also make early assessment in vascular disease. Hypoechoic, heterogeneous echo plaque, irregular patches, plaques and plaque stability of the surface located at the bifurcation vascular ulcers difference should be highly valued.2.Carotid ultrosound can detect carotid artery stenosis and diagnose ischemic stroke accurately. There is more stenosis in intracranial vessels than extracranial vessels.Unlike sever stenosis,moderate stenosis plays a greater impact on blood and unstable plaque which cause the plaque breakage easierly, even yet becoming a severe stenosis.Plaque may have come off and cause acute stroke symptoms,which are more severe;however, in patients with severe stenosis of cerebral ischemia in chronic long-term disease, often has formed collateral circulation compensatory blood vessels.Sometimes,stroke occurs followed by occlusion of the vascular disease,due to compensatory blood supply,clinical symptoms may not be very heavy.3.Carotid ultrasound combined with TCD can not only make up the shortage of evaluation of the neck vascular by examining the intracranial vascular, but also play a comprehensive assessment of the condition of patients with ischemic stroke, and locate the lesion clearly, is much more effective in diagnosis.