急性缺血性脑卒中磁敏感加权成像中低信号血管影的临床应用初探

目的 探讨磁敏感加权成像(SWI)中的低信号血管影在急性缺血性脑卒中(acute ischemic stroke,AIS)诊断中的临床应用价值.资料与方法 选择符合纳入标准的AIS患者11例,发病时间3～48 h,其中男性8例,女性3例,年龄28～85岁,行MRI.序列:T_1WI,T_2WI,T_2液体衰减反转恢复序列(T_2FLAIR),扩散加权成像(DWI),三维时间飞跃法磁共振血管成像(3D TOF MRA),SWI,灌注加权成像(PWI)及T_1WQI增强扫描.由3名有经验的神经放射学医师采用盲法分析MRI结果.结果 11例患者均可见大脑中动脉(MCA)供血区缺血病灶.SWI显示MCA内低信号与MRA显示的颈内动脉(ICA)、MCA血管阻塞有较好的相关性(Spearman等级相关系数ps=0.7698,P=0.0056),其预测ICA、MCA血管阻塞的灵敏性为100%,特异性为66.7%.SWI示11例中4例缺血区内可见异常的静脉血管影,PWI显示病灶体积与缺血区内出现走行僵直的静脉血管影这一征象有较好的相关性(Spearman等级相关系数ps=0.8367,P=0.0013);相对平均通过时间(rMIT)与缺血区内出现走行僵直的静脉血管影这一征象也有较好的相关性(Spearman等级相关系数ps=0.7188,P=0.0127).T_1WI增强扫描示1例可见MCA管壁强化.结论 AIS患者SWI中的低信号血管影与血栓形成及血流速度减慢有关,即其病理机制与去氧血红蛋白浓度增加有关.

Detection of Hypointense Blood Vessel in Acute Ischemic Stroke Patients by Susceptility-weighted Imaging

Objective To evaluate the clinical application value of hypointense blood vessel in acute ischemic stroke patients by susceptility-weighted imaging(SWI). Materials and Methods 11 cases of the acute ischemic stroke patients (eight men and three women;age range,28-85 years; onset of symptoms,3-48 hours)were collected in the study according to the inclusion criteria. All patients underwent MR. The MRI protocol included T_1 WI, T_2 WI, T_2 FLAIR, DWI,3D TOF MRA,SWI,PWI and T, contrast. The MRI data was blindly analyzed by three experienced neuroradiologists. Results A territorial MCA infarct was found on imaging studies in all 11 patients. There was good correlation between the hypointense MCA by SWI and the ICA or MCA occlusion by 3D TOF MRA (ps =0.7698,P =0.0056). Sensitivity was 100% and specificity was 66.7%. Abnormal hypointense veins in the territorial MCA infarct were obvious at SWI in 4 of 11 patients. There was good correlation between the hypointense veins and PWI lesion volume (ps =0.8367 ,P = 0.0013)and relative mean transmit time (rMTT) (ps =0.7188,P = 0.0127). MCA wall enhanced at T1 enhancement imaging in 1 of 11 patients. Conclusion Hypointense blood vessel in acute ischemic stroke patients by susceptility-weighted imaging may be correlated with deoxyhemoglnhin concentration.