FLAIR序列在脑部疾病中的应用研究

目的　对比脑梗塞、脑出血、脑炎患者颅脑MR平扫时FLAIR序列与SE序列T2 WI的差异。方法　采用液体衰减翻转恢复序列 (FLAIR)和SE序列T1 WI、T2 WI序列MR技术 ,对 36例脑梗塞、1 8例脑出血、1 0例脑炎患者行颅脑MR平扫。观察、统计、测量这三类疾病FLAIR序列与常规T2 WI序列的MR信号强度、病灶面积、数目、分布。结果　早期脑梗塞患者FLAIR序列与常规T2 WI信号强度相同 ,病灶面积显示FLAIR序列小于T2 WI序列。晚期脑梗塞患者尤其在脑软化灶形成后FLAIR序列呈现明显低信号 ,而T2 WI为明显高信号。中期和晚期FLAIR序列发现脑梗塞病灶优于T2 WI序列 ,在近脑表面部FLAIR序列有其明显的优势。各期脑出血患者FLAIR序列的信号强度与T2 WI序列相似。FLAIR序列在脑炎患者的病灶面积显示上要小于T2 WI,显示的病灶边界比T2 WI序列清晰。结论　FLAIR序列在显示脑梗塞尤其是靠近脑表面的梗塞灶、鉴别脑软化灶和脱髓鞘改变以及脑炎病灶面积的显示上优于T2 WI。

Study of FLAIR Pulse Sequence in Cerebral Lesions

Objective To compare the findings between fluid-attenuated inversion recovery(FLAIR)pulse sequence and routine MRI in the cerebral infarction,intracerebral hemorrhage and encephalitis.Methods The images of 36 cases of cerebral infarction,18 cases of intracerebral hemorrhage and 10 cases of encephalitis were performed by FLAIR pulse sequence and routine MRI.MRI signal intensity,lesion area,number and distribution were measured and compared.Results The signal intensity was same on FLAIR pulse and routine T 2WI in early cerebral infarction,but the lesion area on FLAIR pulse was smaller than that of routine T 2WI.An obvious low signal intensity was found on FLAIR pulse in advanced cerebral infarction,especially in encephalomalacia focus,which was obvious high signal intensity on routine T 2WI.More lesions were demonstrated on FLAIR pulse than that on routine T 2WI as for the media and advanced cerebral infarction,especially in brain surface.The signal intensity on FLAIR pulse was similar to that on routine T 2WI in every stages of intracerebral hemorrhage.The lesion area on FLAIR was smaller than that on routine T 2WI as for the encephalitis,but the lesion edge was superior to routine T 2WI.Conclusion The FLAIR pulse sequence is superior to routine T 2WI in demonstrating cerebral infarction in brain surface,differentiating the encephalomalacia and demyelination,and showing the encephalitis edge.