三维高分辨率磁共振血管壁成像用于研究颅内动脉粥样硬化斑块强化与缺血性卒中的关系

 目的   分析三维高分辨率磁共振(high-resolution magnetic resonance imaging,HR-MRI)血管壁成像技术用于评价颅内动脉粥样硬化斑块强化的可重复性,并探讨斑块强化特点与缺血性卒中的关系。方法   收集52例因颅内动脉粥样硬化导致的缺血性卒中患者,行3.0 T常规头颅MRI、三维时间飞跃法磁共振血管造影及HR-MRI扫描,将每例患者的斑块分为责任斑块与非责任斑块。责任斑块为梗死灶供血动脉上唯一的斑块或最狭窄处的斑块,非责任斑块为非供血动脉上的斑块及梗死灶供血动脉上非最狭窄处的斑块。由两名观察者独立判断斑块的强化等级,应用Mann-Whitney U检验统计分析两组斑块强化等级和斑块处血管狭窄率的差异,应用二分类Logistic回归分析法研究斑块强化等级与责任斑块的关系。结果   52例缺血性卒中患者中颅内动脉粥样硬化斑块共118个,其中责任斑块52个,非责任斑块66个。责任斑块组中,40个斑块明显强化,9个轻度强化,3个无强化;非责任斑块组中,4个斑块明显强化,24个轻度强化,38个无强化。观察者内与观察者间对斑块强化等级评价一致性高(Kappa＞0.75)。责任斑块组斑块强化等级(Z=-7.787,P<0.01)和斑块处血管狭窄率(Z=-5.327,P<0.01)均大于非责任斑块组,二分类Logistic回归结果显示斑块明显强化为责任斑块的独立影响因素(OR:74.3,95%CI:15.0～367.1,P<0.01)。结论   三维HR-MRI评价颅内动脉粥样硬化斑块强化的可重复性好;斑块强化多见于责任斑块,可能是发生缺血性卒中的重要危险因素。

Intracranial atherosclerotic plaque enhancement associated withischemic stroke:a study with three-dimensional high-resolutionmagnetic resonance vessel wall imaging

Objective    To evaluate the reproducibility of three-dimensional high-resolution magnetic resonance imaging (HR-MRI) for vessel wall in demonstration of intracranial atherosclerotic plaque enhancement and to explore the relationship between plaque enhancement and ischemic stroke.Methods    Fifty-two patients with ischemic stroke underwent traditional head MRI,three-dimensionaltime of flight magnetic resonance angiography and HR-MRI on a 3.0T MRI scanner.Each identified intracranial plaque was classified as either culprit (the only or most stenotic lesion upstream from a stroke) or non-culprit (not the most stenotic lesion upstream from a stroke or not within the vascular territory of a stroke).The degree of plaque enhancement was graded by two independent radiologists.The degree of plaque enhancement and luminal stenosis were compared between the culprit group and the non-culprit group by using Mann-Whitney U test.Binary logistic regression analysis was performed to assess the relation between the degree of plaque enhancement and culprit plaques.Results    Total 118 plaques were identified in 52 patients with ischemic stroke (52 culprit plaques and 66 non-culprit plaques).The degree of enhancement was rated as strong,moderate and none in 40,9 and 3 culprit plaques,and in 4,24 and 38 non-culprit plaques.Both intra-observer and inter-observer agreement were high for identification of plaque enhancement (kappa＞0.75).For culprit plaques group,the degree of plaque enhancement(Z=-7.787,P<0.01) and luminal stenosis (Z=-5.327,P<0.01) were significantly higher than those in the non-culprit group.Binary logistic regression analysis revealed that strong enhancement of plaques was independently associated with culprit plaques (OR:74.3,95%CI:15.0-367.1,P<0.01).Conclusions    Three-dimensional HR-MRI detects enhancement of intracranial plaques with high reproducibility.Enhancement is more common in culprit plaques and is associated with the likelihood of ischemic stroke.