Application Of High Resolution-vessel Wall Imaging In Perforating Artery Infarct With Nonstenotic MCA

Background and objectivePerforating artery infarction is mostly associated with the atherosclerosis of origin or/and proximal segment and fibrous vitreous degeneration of distal segment of perforating artery.The corresponding pathological types are branch atherosclerosis(BAD)and lacunar infarction(LI)respectively.Because BAD is prone to clinical progress and different from LI about treatment principles and prognosis.,it is very important to effectively distinguish BAD from LI.High resolution-vessel imaging(HR-VWI)can provide not only the plaque load of parent artery,but also the information of the perforating artery,so it is an ideal tool to distinguish the pathological classification of perforating artery infarction effectively.The purpose of our study is to compare the imaging information provided by conventional MRI and HR-VWI,to find some possible biological indicators that may distinguish the two pathological types,and to explore the pathophysiological mechanism of imaging differences.Materials and methodsA total of 53 patients with acute lenticulostriate artery infarction without middle cerebral artery(MCA)stenosis on magnetic resonance angiography(MRA)in Tianjin Huanhu Hospital from January 2017 to December 2019 were enrolled.All patients completed routine head magnetic resonance imaging(MRI),MRA and HR-VWI examination.Based on CISS,all patients were divided into plaque group(large artery atherosclerosis,LAA group)and non-plaque group(penetrating artery disease,PAD group)according to the presence or absence of plaque in the MCA-M1 segment of the affected hemisphere.In the PAD group,according to the length and diameter of the infarct on DWI,the patients were subdivided into two subgroups: PAD-BAD and PAD-LI(PAD-BAD group was defined as infarct length ≥ 15 mm on axial DWI and involved ≥ 3 layers;PAD-LI group was defined as infarct length < 15 mm on axial DWI).Demographic data(gender,age),stroke risk factors(hypertension,diabetes,hyperlipidemia,smoking)and laboratory tests(triglyceride,total cholesterol,highdensity lipoprotein,low density lipoprotein,fasting blood glucose)were collected.The characteristics of the lesions were recorded on conventional MRI,including length and location of infarct area and total cerebral small vessel disease(CSVD)score.The location of plaque was recorded on HR-VWI.The numbers of LSA stem and branch and the total length of LSA of bilateral hemispheres were recorded respectively.Then calculated the laterality index of LSA stem’s number,branch’s number and the total length.SPSS19.0 statistical software was used to analyze the data,and the differences between LAA group and PAD group,LAA group,PAD-BAD group and PAD-LI group were compared.Results53 subjects were included,including 37 males and 16 females.28(52.8%)cases had plaques in the MCA-M1 segment of the affected side,that is,LAA group,and 25cases(47.2%)in non-plaque group,namely,PAD group.In PAD group,there were 9patients in PAD-BAD group and 16 patients in PAD-LI group.1.In LAA group and PAD group,length of infarct in LAA group was larger than that in PAD group(1.70±0.79 cm vs 1.36±0.74cm),but there was no significant difference(P>0.05).The incidence of proximal lesion in LAA group was significantly higher than that in PAD group(P=0.007).About the total CSVD score,there was no significant difference between LAA group and PAD group(P>0.05).The laterality index of branch’s number and total length in LAA group were higher than those in PAD group,and the difference was statistically significant(P=0.005;P=0.002).There was no significant difference in demographic data,stroke risk factors and related clinical indexes between the two groups.2.In the LAA group,14 cases(50%)had plaques involving superior or/and dorsal walls.According to the location of the plaque,it was divided into superior dorsal wall and non-superior dorsal wall,and there was no significant difference in demographic data,stroke risk factors clinical indexes and imaging features between them(P>0.05).3.There was no significant difference in stroke risk factors and related clinical indexes among LAA group,PAD-BAD group and PAD-LI group(P>0.05).The incidence of proximal lesions in LAA group and PAD-BAD group was higher than that in PAD-LI group(P=0.000;P=0.018,FDR corrected),but there was nodifference between LAA group and PAD-BAD group(P>0.05).The total CSVD score in LAA group and PAD-BAD group was lower than that in PAD-LI group(P=0.001;P=0.000,FDR corrected),but there was no difference between LAA group and PAD-BAD group(P>0.05).The laterality index of branch’s number and total length of LSA in LAA group and PAD-BAD group were higher than those in PAD-LI group(P=0.003 and P=0.003,FDR corrected;P=0.041 and P=0.017,FDR corrected),but there was no difference between LAA and PAD-BAD groups(P>0.05).ConclusionsHR-VWI enabled comprehensive and quantitative evaluation of intracranial atherosclerotic plaques and perforating arteries,and provide a basis for the diagnosis of BAD.Compared with LI,the number and total length of LSA decreased more significantly in BAD,and the state of perforating arteries may become an important imaging index to evaluate BAD.