3.0T HRMRI头颈联合技术对症状性MCA狭窄患者颅内外动脉管壁病变的诊断价值

The value of 3.0T High-resolution magnetic resonance imaging of simultaneous carotid and intracranial vessel wall in diagnosing intra-and extracranial arterial wall abnormality in patients with symptomatic middle cerebral arterial stenosis

目的探讨症状性大脑中动脉(MCA)狭窄患者颅内外动脉管壁病变特点和3.0T高分辨磁共振成像(High-resolution magnetic resonance imaging,HRMRI)头颈联合技术的临床应用价值。方法 11例症状性MCA狭窄患者接受三维增强磁共振血管成像(3D ce-MRA)与3.0T HRMRI的T_1w-db SPACE平扫和T_1w-db SPACE增强扫描,并结合头颈部颅内外动脉管壁不间断联合扫描新技术。结果共扫描11例患者的88处颅内外动脉管壁,其结果发现:1例中枢神经系统血管炎,其左侧MCA及左侧颈内动脉(ICA)颅内段在T_1w-db SPACE像上表现为管壁环形增厚及环形强化;1例颅内动脉夹层,其左侧MCA在T_1w-db SPACE像呈长条状高信号,相应高信号在T_2wdb SPACE像上为等低信号;9例动脉粥样硬化患者均合并双侧MCA粥样硬化斑块,表现为管壁偏心性增厚,其中8例(88.9%)合并颅内外动脉粥样硬化,增强扫描见6例(67%)颅内外动脉粥样硬化斑块均有强化。比较3D ceMRA与HRMRI结果发现,88处血管中,23处血管的3D ce-MRA与HRMRI均未见明显异常;31处血管的3D ceMRA与HRMRI显示相对一致,即3D ce-MRA显示狭窄或者扩张、HRMRI显示管壁呈不同程度的增厚或附壁斑块;34处血管的3D ce-MRA与HRMRI显示欠一致,其中,26处血管的3D ce-MRA大致正常而HRMRI显示管壁增厚(5处)或斑块(21处),8处血管的3D ce-MRA显示轻度狭窄(6处)或扩张(2处)而HRMRI显示管腔外径及管壁均大致正常。判断颅内外动脉异常的组间一致性可(3D ce-MRA、HRMRI的Kappa值分别为0.67、0.69,P<0.001)。结论 3.0T HRMRI头颈联合技术可清晰地显示颅内外动脉的管壁结构和病变特点,识别3D ce-MRA未能发现的狭窄,甄别动脉狭窄的病因,对颅内外动脉管壁病变的诊断具有较高的临床应用价值。

Objective To investigate the intra-and extracranial arterial wall abnormality in patients with symptomatic middle cerebral arterial（MCA） stenosis and clinical value of 3.0T High-resolution magnetic resonance imaging（HRMRI） of simultaneous carotid and intracranial vessel wall. Method Eleven patients with symptomatic MCA stenosis underwent three dimensional contrast-enhanced MRA（3D ce-MRA）and 3.0T HRMRI. 3.0T HRMRI included preeontrast and post- contrast T1 -db SPACE, and was combined with simultaneous carotid and intracranial vessel wall imaging. Result Eighty- eight vessel walls of 11 patients indicated：one patient had central nervous system vasculitis with concentric thickening and enhancement of left MCA and internal carotid artery （ ICA ） on T1 -db SPACE ; one had intracranial arterial dissection with long-striped hyper-intensity of left MCA on T1 -db SPACE and iso-intensity and hypo-intensity of left MCA on T2-db SPACE;nine had atherosclerosis with bilateral MCA atherosclerotic plaques manifested as eccentric thickened wall, eight out of 9 patients had both intra-and extracranial atherosclerotic plaques, and 6 （67%）patients＇ intra-and extracranial athero- sclerotic plaques were enhanced simultaneously. Comparison of 3D ee-MRA and HRMRI showed 23 vessel walls were nor- real on both series;Thirl vessel walls were abnormal on both series,in which 3D ce-MRA showed stenosis or dilation while HRMRI showed the arterial wall thickened or loaded with plaques. In other 34 vessel walls, different findings between 3D ce-MRA and HRMRI were detected：26 abnormal vessel walls （5 with thickened wall and 21 with plaques） shown on HRMRI were normal on 3 D ce-MRA, while 6 stenotic and 2 dilated vessel walls on 3 D ce-MRA were relatively normal on HRMRI. Inter-observer reproducibility was good for identifying intra-and extracranial arterial wall abnormality on 3D ce-MRA and HRMRI（ Kappa was 0.67,0.69, both P 〈 0. 001 ）. Conclusion 3.0T HRMRI of simultaneous carotid and intracranial vessel wall can help to clearly visualize the anatomy and pathological changes of intra-and extracranial arterial wall, identify the stenosis missed on 3D ce-MRA, distinguish causes of arterial stenosis, and is valuable to diagnose intra-and extracranial arterial wall abnormality.