Study Characteristics Of Cerebrovascular Atherosclerosis On 3.0T High Resolution Magnetic Resonance Imaging

Part one:Study the advantage of 3.0T HR-MRI imaging on cerebrovascular atherosclerosisObjectiveUsing 3.0 Tesla High-resolution MRI to investigate the occurrence of cerebrovascular atherosclerosis with Lacunar infarctsbutnostenosis on MRA,by looking for responsible plaque and analysizingthe characteristics of its position, shape, composition.MethodBetween September 2013 to April 2014 period,47 patients in the Nanfang hospital Southern medical university were chosen,41 males and 6 females,aged 39-77 years,mean age 54.6±9.2 years old,using a dual gradient 3.0 T magnetic resonance.Routine MRI scans showed that all patients with lacunar infarcts,but three-dimensional time of flight MRA shows had no significant stenosis,and then did HRMRI.The scanning processes were all operated on 3.0T magnetic resonance scanner. On the condition of HR-MRI,inspection was conducted ertically to the basilar artery or middle cerebral artery.2 physicians with clinical experience of MR observed and complete the post-processing procedure in the MRI image processing workstation,the HR-MRI images were enlarged 2.5-3.0 times,first estimate whether the wall of the carrier artery is thickening,and then determine the narrowest level(maximal luminal narrowing, MLN) by visually,manual depict blood vessels inside and outside the boundary,the workstation software automatically calculates the vessel area(VA),lumen area(LA),if you can not determine the narrowest level visually,then you should better aquire the possible one and count it as MLN.reference level is determined by visual inspection, preference lesion proximal to normal levels as the reference lumen(RL). If no suitable proximal end founded, seleceted the distal one as the reference level, calculates the VA and LA of the reference level by workstation software.Wall area(WA)= VA-LA,the narrowest level of plaque area(PA)= WA (MLN)-WA (RL),stenosis rate= [1-LA (MLN)/LA (RL)] × 100%,remodeling index(RI)= VA (MLN)/VA (RL). the method to determine the position of plaque is to design a square along the vessel, divided into four quadrants with two diagonals,MCA is divided into anterior wall,posterior wall,superior wall,inferior wall and multiple,BA is divided into anterior,posterior,left side and right side wall, Select the quadrant which has the maximum wall thickness on the cross-sectional images as the quadrant which plaque lies.and observe the location, morphology and signal characteristics of the responsibility plaque.ResultsMCA plaques as follows: ①Distribution:anterior,posterior,superior,inferior and multiple followed by the percentage of 13.2%,18.4%,26.3%,23.7%,18.4%;eccentric plaques 31,accounting for 81.6% of all MCA plaques,20 plaques Cover the open of the lenticulostriate artery.②Ingredient:After pressure grease,2 plaques disappeared,16 plaques signal decresed partially,9 plaques with no significant change,8 plaque fibrous cap showed of higher signal of T2WI,5 plaques of hemorrhage signal.③10 plaques reduced significantly after therapy by review.BA plaques as follows:① Distribution:anterior,posterior,left side,right side and multiple followed by the percentage of 33.3%,33.3%,22.2%,11.1%,0%;eccentric plaques 8, accounting for 88.9% of all BA plaques.② Ingredient:After pressure grease,2 plaques disappeared,3 plaques signal decresed partially,3 plaques with no significant change.2 plaques fibrous cap showed of higher signal of T2WI,2 plaques of hemorrhage signal.③ 3 plaques reduced significantly after therapy by review.Compared narrowest stenosis rate with degree of stenosis by DSA, statistics showed that there was a significant correlation (p<0.001) between then; 20 cases were PR,11 cases were NR, there was a significant correlation with DSA (p=0.002, p <0.05); wethere the signal of MRA was reduced was correlated with stenosis of DSA (p=0.009, p<0.05).Conclusion3D-TOF MRA without gadolinium contrast agents,it has the advantage to show the whole cerebral vessel stenosis, but not better show the structure of the vessel wall,and understimulatation is a tendency,3.0THR-MRI analysis the vessel wall noninvasively, it can display the location and morphology and vascular remodeling of responsibility plaque,the composition of the plaques can be well-acquired,well compensate for the lack of 3D-TOF MRA.Part two:Comparative analysis of symptomatic lacunar infarction ipsilateral and contralateral MCA atherosclerotic plaqueObjectiveUsing 3.0T MR to conduct HR-MRI examination between the patient who sufferds symptomatic lacunar infarction,both of the ipsilateral and contralateral MCA was conducted, analysis the haracteristics of plaques,looking for the plaques characteristics which lead to ischemic cerebrovascular events,therefore, early targeted interventions should be processed as soon as possible.MethodsThe patient of the symptomatic lacunar infarction share the same origin,16 cases excluded from this study,including 9 cases of BA,7 cases of MCA which found contralateral old lacunar infarction,the remaining 31 cases were included in the study.38 males and 3 females,mean age 52.1±7.2 years old,using the Philips Achieva 3.0 T superconductive MRI 8-channel head coil.According to the conventional location of lacunar infarction. HR-MRI check vertical to the MCA was carried out, ipsilateral 9 layers corresponding contralateral site of 9 layers, the scan sequence and method stay the sanme with the first part.ResultsIpsilateral MCA plaque as follows:①Distribution:5 cases of anterior,6 cases of posterior,8 cases of superior,6 cases of inferior and 6 of multiple,the percentage was 16.1%,1904%,25.8%,19.4%,19.4%;② Plaque morphology:6 cases of annular plaques,24 of curved plaques,1 case of dome shaped plaques;③Relationship with branch artery:19 plaquescovered the beginning of the lenticulostriate artery.Contralateral MCA plaque as follows:① Distribution:10 cases of anterior,11 cases of posterior,3 cases of superior,6 cases of inferior and 1 of multiple,the percentage was 32.3%,35.5%,9.7%,19.4%,3.2%;②Plaque morphology:1 cases of annular plaque,12 cases of curved plaques,18 cases of dome-shaped plaques;③ Relationship with branch artery:4 plaques covered the beginning of the lenticulostriate artery.Compared ipsilateral MCA plaques and contralateral with distribution, morphology and relationship with branch, statistics showed there was difference (p <0.05) on the distribution; morphology and relationship with branch plaques were significant difference (p<0.001).ConclusionOne side of the MCA atherosclerosis,there may still exit some atherosclerosis on the opposite side to some degree,it maybe a predictor of cardiovascular events if evauate the distribution,morphology and the relationship with branch artery comprehensively.As a noninvasive means,HR-MRI can be a comprehensive evaluation of the plaque.