Clinical Study Of High Resolution MRI Combined With DWI In Identifying Vulnerable Carotid Plaque

Objective: To explore the application of high resolution MRI(HR-MRI)combined with diffusion-weighted imaging(DWI)in the quantitative analysis and accurate recognition of vulnerable plaques(VP)and their characteristic components,and to study the correlation between Apparent diffusion coefficient(ADC)and serum inflammatory markers of vulnerable plaque.Materials and methods: From September 2019 to March 2020,60 outpatients and inpatients from departments of Neurology in our Hospital were selected in this study.Carotid artery plaque was confirmed by carotid artery ultrasound,which met the inclusion criteria and exclusion criteria.Carotid plaques were examined by HR-MRI and DWI sequence,and the average ADC values of plaques and regions of interest were measured by two physicians independently.At the same time,high-sensitivity C-reactive protein(hs-CRP),myeloperoxidase(MPO)and erythrocyte sedimentation rate(ESR)were measured.The average ADC obtained by the two physicians was analyzed for consistency.According to the signal performance of plaque on different HR-MRI sequences,the patients were divided into vulnerable plaque group(VP group)and non vulnerable plaque group(N Group).The ADC mean value of plaque in VP group and N group was compared,the ADC mean value of different characteristic components of plaque and vascular wall in VP group was compared,and the levels of serum inflammatory markers(hs CRP,MPO and ESR)in VP group and N group were compared to evaluate the patients’ serum inflammatory markers The correlation between the level of markers and the average ADC of plaque.All the results were analyzed by SPSS 25.0.When p < 0.05,considered to be a statistically significant difference.Result: 1.The difference between VP group and N group was not statistically significant in general baseline data(gender,age,history,smoking,drinking,blood lipid and homocysteine level)(p > 0.05).The ADC mean values of different ROI measured by the two physicians have good consistency.3.The average ADC values of different ROI(unit: X 10-3 mm2 / s)obtained in this study were: VP group(n = 26): 1.64 ± 0.21;N group(n = 34): 1.91 ± 0.28.The average ADC values of plaque in VP group were lower than those in N Group,the difference was statistically significant(p < 0.05).Lipid core(LC)(n = 34): 0.57 ± 0.16;fiber cap(n = 34): 1.67 ± 0.28;intra plaque hemorrhage(IPH)(n = 10): 1.05 ± 0.13;vascular wall(n = 78): 1.36 ± 0.21.The ADC mean values of blood vessel wall,lipid core,fibrous cap and plaque internal hemorrhage were statistically significant(p < 0.05).4.The level of hs-CRP and MPO in VP group was higher than that in N group(p < 0.05).The level of hs-CRP was correlated with the ADC value of plaque(r =-0.784,p < 0.05).The level of MPO was correlated with the ADC value of plaque(r =-0.613,p < 0.05).The difference of ESR level between the two groups was not significant.(p > 0.05).The correlation between ESR level and ADC value of plaque was not significant.Conclusion: 1.The ADC value of ROI of plaque measured by high resolution MRI and DWI has good repeatability.2.High resolution magnetic resonance imaging combined with DWI can clearly show the characteristics of blood vessel wall and plaque(such as lipid core,fibrous cap and bleeding in plaque),and it can be identified by measuring ADC value.ADC value can reflect the inflammation of plaque to a certain extent.3.Serum inflammatory markers(hs CRP and MPO)have certain diagnostic value for vulnerable plaque,and can be used as a screening method.