7.0T磁共振成像观察耳后给药促进药物进入内耳的可行性

Feasibility study of inner ear drug delivery via post-auricular injection using 7.0 Tesla MRI

目的借助磁共振成像系统,观察新给药方式耳后给药,药物在内耳的吸收过程,探讨耳后给药治疗内耳疾病的可行性。方法 12只白色红目豚鼠随机分为2组,一组耳后注射造影剂,一组静脉注射造影剂。7.0T小动物专用磁共振成像系统,在给药前、给药后0.5h、1h、2h、3h、4h、6h、8h、12h、24h、48h,分别进行磁共振T1加权像成像。测量右侧耳蜗底转鼓阶的信号强度,描绘信号-时间曲线,计算曲线下面积,对比耳后组与静脉组之间的差异。结果耳后组与静脉组信号-时间曲线下面积分别为68.14×105及36.17×105,耳后组面积更大,差异有统计学意义(P<0.05)。结论耳后给药治疗内耳疾病是可行的,局部疗效好,全身并发症少,便于在临床推广应用。

Objective To investigate the feasibility of postauricular injection as a drug administration route in treating inner ear disorders. Methods Twelve albino guinea pigs were divided randomly into two groups to receive either a post-auricular or intravenous bolus of gadopentetate dimeglumine （Gd-DTPA）. A 7.0 Tesla MRI system, specially designed for small an- imals, was used to observe the signal changes of gadolinium enhanced images of the right cochlea for forty-eight hours. The observation time points included pre-administration, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 24 and 48 h post-administration. The rela- tive signal intensity in the right scala tympani of the basal turn was measured to evaluate indirectly the dynamic Gd uptake in the perilymph. The area under the signal-time curve was calculated and compared between the two administration routes. Results Post-auricularly treated guinea pigs revealed a higher area under the signal - time curve from pre-injection to the last time point （P 〈 0.05）. Conclusions Post-auricular injection may be a potential and efficient route for inner ear drug delivery.