MRI常规扫描序列与EPI序列对弥漫性轴索损伤诊断的对比研究

Echo planar imaging in patients with diffuse axonal injury:comparative studies with fast spin echo and spin echo imaging

目的 评价MRI常规FSET2 WI、SET1WI序列与EPI序列对弥漫性轴索损伤的诊断价值。材料与方法 42例弥漫性轴索损伤患者均进行MRI常规FSET2 WI、SET1WI和EPI扫描。 2 9例检查前静脉注射 5～ 10毫克安定。结果FSET2 WI、SET1WI序列运动伪影的发生率分别为 83 .3 %、71.4% ;EPI序列无一例出现运动伪影。EPI病灶与正常脑白质的对比度显著低于FSET2 WI序列 (p <0 .0 0 1) ,空间分辨率较FSET2 WI、SET1WI序列差 ,信噪比最高。EPI共显示 143个病灶 ,为FSET2 WI显示病灶 (174个 )的 82 .2 % ,SET1WI序列显示 133个病灶。对于直径大于 1cm的病灶 ,EPI病灶显示数为FSET2 WI序列的 91.7%。FSET2 WI、SET1WI序列所见的DAI主要并发症 ,EPI序列大都能显示。结论 EPI的对比度与分辨率不如FSET2 WI ,对脑内小病灶、出血灶及脑底部病灶的显示还存在一定的限度 ,但EPI扫描时间极短 ,图像信噪比高、无运动伪影 ,能保证对脑内大多数病灶的显示 ,对弥漫性轴索损伤的诊断有重要的诊断价值 ,尤其对伴有烦噪的急性脑外伤患者或病情不允许进行长时间检查的患者 ,EPI可代替FSET2 WI进行检查。

Purpose [WT5”BZ]To evaluate the value of FSE T 2WI,SE T 1WI and EPI in the diagnosis of diffuse axonal injury(DAI).[WT5”HZ]Materials and methods[WT5”BZ] 42 cases of diffusion axonal injury underwent FSE,SE and EPI scan.5～10mg diazepam was injected intra venous for 29 patients before examination.[WT5”HZ]Results[WT5”BZ] Motion artifacts were seen in 71.4%,83.3% of all patients for FSE images and SE images respectively,no motion artifacts for EPI,the lesion-to-white matter contrast and spatial resolution of EPI were found to be significantly inferior to FSE T 2WI(p<0.001),signal-to-noise ratio of EPI were found to be significantly superior to FSE imaging(p<0.001).174 lesions were found in FSE images,while 143 lesions were found in EPI and 133 lesions were found in SE images.In FSE images,66 lesions were found larger than 1cm in diameter,EPI detected 91.7% of all these lesions.[WT5”HZ]Conclusion [WT5”BZ]The lesion-to-white matter contrast,spatial resolution of EPI was inferior to FSE images.The lesion detection for smaller lesions,lesions in cerebellum or brainstem,and hemorrhagic lesions was also inferior to FSE images of SE images.But EPI had the fastest scan time,best signal-to-noise ratio,and no motion artifacts,could detect most of lesions.EPI play an importnant role in the diagnosis of DAI,especially for acute injury patients which associated with dysphoria,or severe injuries which could not suffer from a long time scan,in this situation,EPI should replace FSE T 2WI. [WT5”HZ]