螯合α-甲基色氨酸的超顺磁性氧化铁纳米粒子用于颞叶癫(癎)MRI的最佳扫描时间探讨

摘要

Objective To investigate the optimal scan time of MRI using the imaging probe alphamethyl-L-tryptophan(α-MTrp)-superparamagnetic iron oxide nanoparticles (SPIONs) for localizing temporal lobe epilepsy (TLE) foci.Methods α-MTrp-SPIONs were injected into rat models of TLE through the tail vein during the acute and chronic stages (72 h and 8 weeks after status epilepticus,respectively).MRI was performed before and 1,2,4,8,24 h after the injection in all animals,and the T2 values of the epileptogenic regions were measured.One-way repeated measures analysis of variance was used for data analysis.Results Compared with the T2 values before the injection of α-MTrp-SPIONs,the T2 signal of epileptogenic regions after the injection had a negative increased change.The T2 values before and 1,2,4,8,24 h after the injection in acute stage were 112.08±5.85,107.83±6.59,105.08±6.79,95.58±5.14,100.92± 5.81,105.17±6.31 respectively,and those in chronic stage were 112.08±7.53,107.75±7.10,102.75± 5.50,96.17±5.01,97.75±4.37,102.92±4.74.The T2 values after the injection were significantly different from those before the injection (both P＜0.01).The T2 value at 4 h after the injection decreased mostly.Conclusions α-MTrp-SPIONs can precisely localize epileptogenic regions of TLE on MRI.The optimal scan time is 4 h after the injection.%目的 探讨螯合α-甲基色氨酸的超顺磁性氧化铁纳米粒子探针(α-MTrp-SPIONs)MRI特异定位颞叶癫(癎)致(癎)灶的最佳扫描时间.方法 将α-MTrp-SPIONs分别于颞叶癫(癎)急性期(癫(癎)大发作后72 h)、慢性期(癫(癎)大发作后8周)经尾静脉注入模型大鼠体内,于注射前及注射后1、2、4、8、24h同步行T2序列同参数MRI,测量T2值.数据间的比较行单因素重复测量方差分析.结果 急、慢性期癫(癎)大鼠在注射α-MTrp-SPIONs后各时间点的MRI示病灶局部组织T2信号发生负增强,急性期注射前,注射后1、2、4、8、24 h T2值分别为112.08±5.85、107.83±6.59、105.08±6.79、95.58±5.14、100.92±5.81、105.17±6.31,慢性期各时间点T2值分别为112.08±7.53、107.75±7.10、102.75±5.50、96.17±5.01、97.75±4.37、102.92±4.74,给药前后差异均有统计学意义(均P＜0.01);注射后4hT2值下降最明显.结论 α-MTrp-SPIONs MRI能在分子水平上精确定位致(癎)灶,MRI最佳扫描时间是注射后4h.