Three-dimensional High-resolution Vessel Wall Imaging To Investigate The Etiology Of Ischemic Stroke

Objective:Stroke is the leading cause of mortality in China,which characterizes high prevalence,high morbidity and high rate of recurrence.It is critical to effectively prevent the occurrence of stroke and improve the outcome of stroke patients.Stroke etiology,which markedly impacts the response of patients’treatment,is the fundamental issue of stroke and is difficult to determine in clinic.Investigation of stroke etiology is of critical to improve the management of stroke patients.In the present study,we applied high-resolution vessel wall imaging as the key approach to investigate the visualization of vessel wall from intracranial and carotid large arteries to intracranial small penetrating arteries,and its clinical usefulness.We aimed to identify promising imaging markers closely associated with etiology of ischemic stroke,thus to provide new method for clinical diagnosis of stroke etiology.Methods:The present study prospectively recruited 55 patients with ischemic stroke.All patients had performed the newly developed three dimensional cervical and intracranial arterial vessel wall joint imaging sequence.Imaging quality of carotid artery and intracranial artery was semi-quantitatively assessed according to the clarity of vessel wall structure appearance.All images were reviewed by two experienced radiologists to diagnose the etiology of ischemic stroke including large artery atherosclerosis,arterial dissection,vasculitis and Moyamoya disease.In large atherosclerosis,plaque number and proportion of intracranial and cervical arterial coexisting lesion was recorded.Plaque vulnerability was evaluated.Based on the investigation of large vessel etiology of ischemic stroke and usefulness of three dimensional vessel wall imaging,we further analyzed the abnormalities of small lenticulostriate artery in penetrating artery supply territory infarction located in basal ganglia.We retrospectively recruited 35 patients with unilateral large striatocapsular infarct(>1.5cm)and single penetrating artery infarct(≤1.5cm)confirmed by diffusion weighted imaging in two imaging center.All patients had performed whole brain three dimensional vessel wall imaging.We visualized the lenticulostriate artery by maximal intensity projection and multiple planner reconstruction.By referring the appearance of lenticulostriate artery at normal side,we compared the pattern of changes of vessel numbers and penetrating depth between patients with different infarct pattern as well as with different groups of lenticulostriate artery involvement.Results:Three dimensional cervical and intracranial arterial vessel wall joint imaging could be acquired in about 8 min,and covered the arterial segments of carotid artery and intracranial artery with a spatial resolution of 0.55mm~3.All segments from intracranial artery,extracranial artery,anterior circulation and posterior circulation were clearly visualized.Imaging quality assessment grade showed no significantly different between precontrast and postcontrast images,which indicated the satisfactory of imaging quality without the administration of contrast agency.Within the 55 patients,43 had confirmed to be large artery atherosclerosis,3 were arterial dissection,2 were Moyamoya disease,2were vasculitis and the left 5 were other etiology.In the 43 patients with large artery atherosclerosis,36 patients had multiple plaques and a total 150 plaques were recorded,within which,there were 122 intracranial arterial plaques and 28 extracranial arterial plaques.Culprit lesions were all diagnosed in these 43 patients including 63 intracranial plaques and 22 extracranial plaques.In the 63 lesions,100%showed enhancement after contrast administration while in the 22 lesions,79%showed enhancement.The changes of vessel numbers and penetrating depth of lenticulostriate artery in large striatocapsular infarct were significantly different from single penetrating artery infarct.Cases with striatocapcular infarct could present the increase of vessel numbers,whereas no vessel number increasement was revealed in cases with single penetrating artery infarct.The changes of vessel numbers and penetrating depth of lenticulostriate artery showed no significant difference between patients with different groups of lenticulostriate artery involvement.Conclusions:The present study stretches the application of the new technique of three dimensional vessel wall imaging.Targeting the etiology of ischemic stroke,the study is innovatively conducted covering from large vessels to small intracranial vessels from several aspects as follows:1)The study primarily investigated the etiology of ischemic stroke by using three dimensional intra-and extra-cranial arterial vessel wall joint imaging;2)The study visualized lenticulostriate artery directly in striatocapsular infarct and single penetrating artery infarct;3)The study found the pattern of changes of lenticulostriate artery’s vessel numbers and penetrating depth which was different between striatocapsular infarct and single penetrating artery infarct.