Clinical Study On Quantitative Evaluation Of Carotid Plaque Vulnerability By Three Dimensional Ultrasound

Objective To quantitatively evaluate the vulnerability of carotid plaques of acute ischemic cerebral infarction patients,the study applied gray-scale median(GSM)and standard wall index(NWI)based on three-dimensional ultrasound(3D-US).GSM and NWI were used to quantitatively analyze different composition of plaque and different plaque load and to reflect the histological and hemodynamic characteristics of plaque.Methods Patients were examined with carotid plaques in the PLA Army General Hospital from December 2015 to August 2016.According to diagnostic criteria for acute ischemic cerebral infarction in Chinese acute ischemic stroke diagnosis and treatment guideline 2014,102 patients were the first onset of acute cerebral ischemic stroke(cerebral infarction group),whose head CT or MRI confirmed that the responsibility of infarction was in the distribution of the internal carotid artery system.105 patients without cerebral vascular disease confirmed by CT or MRI were regarded as control group.The clinical data of two groups were collected,including age,gender,height,weight,body mass index(BMI),smoking,drinking,family history,history of diabetes,history of hypertension,systolic blood pressure,diastolic blood pressure,blood lipid and so on.Vascular plaque quantification(VPQ)software was used to acquire carotid plaque parameters automatically such as GSM,plaque thickness(PT),percentage of lumen area stenosis,plaque volume(PV),lumen area(LA),wall area(WA),NWI,and so on.Applied SPSS18.0 software to compared and analyze the difference between two groups and perform a repeatability test for 3D-US quantitative analysis.Results 1.Comparison of general clinical data: A total of 180 plaques in the cerebral infarction group were analyzed,and 179 plaques in the control group were included in the analysis.There was no significant difference between the two groups in age,gender,body mass index,smoking,drinking,family history,history of diabetes,history of hypertension,systolic blood pressure,diastolic blood pressure,triglyceride,total cholesterol,high density lipoprotein(all P>0.05).The low density lipoprotein in the cerebral infarction group was significantly higher than that in the control group [(3.51±1.20)mmol/L vs(3.10±1.07)mmol/L,t=1.58,P<0.05].2.Comparison of ultrasonic parameters: The GSM value of carotid plaques in cerebral infarction group was significantly lower than that in control group(44.78±11.58 vs 54.36±11.99,t=7.70,P <0.01).The WA in cerebral infarction group was significantly higher than that in control group(53.73±7.82 vs 47.86±11.26,t=3.18,P<0.01).The NWI in cerebral infarction group was significantly higher than that in control group(0.52±0.12 vs 0.46±0.09,t=5.27,P<0.01).There was no significant difference between the two groups in PT,percentage of lumen area stenosis,PV and LA(all P>0.05).Comparison of the degree of stenosis between two groups showed that cerebral infarction group and control group were mainly mild to moderate stenosis,and the proportion of severe stenosis in cerebral infarction group were larger than those in control group(P<0.05).In the degree of mild to moderate area stenosis,the GSM value of plaque in cerebral infarction group was significantly lower than that of control group(42.57±7.07 vs 52.86±6.09,t=6.89,P<0.01).While in the degree of severe area stenosis,there was no significant difference between them(49.33±8.67 vs 50.41±7.34,t=0.59,P>0.05).Different plaque burden divided by mean of NWI resulted in different degree of area stenosis,and the plaque load of NWI more than 0.52 was more likely to result in significant area stenosis.3.The parameters of carotid plaques measured by 3D-US have low variability and high consistency between intra and inter observers.Conclusion The GSM and NWI obtained by 3D-US can quantitatively evaluate the vulnerability of carotid plaques.The lower the GSM value,the higher the risk of vascular thrombosis caused by plaque rupture,while NWI reflects the different degree of stenosis caused by different plaque load.Therefore,the use of 3D-US technology to obtain GSM and NWI parameters in the evaluation of carotid plaque vulnerability and ischemic stroke risk prediction has a certain clinical value.