动脉粥样硬化性大脑中动脉区域TIA功能磁共振成像分析

目的利用弥散加权成像(DWI)、磁共振血管成像(MRA)对大脑中动脉(MCA)区域TIA进行解剖性定位,评价磁共振对临床实践的指导意义。方法对32例TIA患者,在发作1.5h~7d内行头部MRI、DWI、MRA检查,对DWI图像上的高信号与T2WI像、MRA、临床症状、体征进行对照研究。结果2例DWI正常,但MRA颅内大脑中动脉闭塞,病变血管与临床症状相一致。12例DWI正常,MRA仅轻度狭窄或正常。3例DWI有高信号,T2WI无相应病灶为超早期脑梗死,其中MRA1例动脉硬化样改变,2例大脑中动脉闭塞,病灶与体征相符。15例DWI有高信号、T2WI有相应病灶,2例为早期脑梗死、13例为腔隙性脑梗死,其中MRA8例颅内大血管轻到中度狭窄,2例严重狭窄。MRI显示20例(62.5%)存在多发陈旧腔隙性梗死灶。对于TIA患者发作时MRA相应病变进行χ2四格表精确检验,DWI异常组与正常组比较P<0.05,MRA大血管病变是TIA预后形成梗死的独立危险因素。结论对TIA患者行MRI、DWI、MRA检查,能及时发现超早期脑梗死,还能对新发腔隙性脑梗死准确定位,科学指导临床早期干预治疗。MRA可提供1.2级大血管的供血状态,指导后续的2级预防。

The analysis of TIA atherosclerosis in MCA territory with MRI

Objective To locate transient cerebral ischemic attack (TIA) within MCA territory with MR diffusion-weighted imaging(DWI)and MR angiography(MRA),and to evaluate the role of fMRI in clinic practising.Method MRI,DWI,MRA were performed on 32 patients with TIA in 1.5h~7d after onset of the disease.The abnormal high signal seen on DWI was contrasted and observed.Results 2 patients' DWI were normal but MRA showed middle cerebral artery occlusive,and pathological vessels agreed with clinical symptoms.12 patients' DWI were normal and MRA showed normal or mild stenosis.3 patients'DWI were found focuses but T_2WI showed no corresponding focus,these focal lesions were regarded as ultra-acute cerebral infarction.Among them,1 patients'MRA showed arteriosclerosis,the other 2 patients'MRA showed middle cerebral arteries occlusive,and focuses agreed with clinical symptoms.15 patients'DWI were abnormal and T_2WI showed corresponding focuses,these lesions were distinguished as 2 acute cerebral infarctions and 13 acute lacunar infarctions.of them,8 patients had relevant cerebral arteries stenosis from mild to moderate,2 patients had severe stenosis. 20(62.5%) patients showed chronic multiple lacunar infarction on MRI.A statistically significant difference in pathological changes on MRA were found between the normal and abnormal DWI,P<0.05.Conclusions It is helpful to finding super-acute stroke and acute lacunar infarction guiding treatment for patients with TIA to perform functional MRI.MRA can depict the state of large vessel about blood supplying,which will guide subsequent preventing.