用4.7特斯拉磁共振成像活体内观测豚鼠实验性内淋巴积水

目的探讨用4.7特斯拉试验用磁共振成像系统能否在豚鼠中检测内淋巴积水.方法20只白色或者杂色豚鼠用于该研究.5只正常豚鼠作为对照组,15只豚鼠用于制作内淋巴积水模型.9只内淋巴囊破坏组中的5只和6只内淋巴囊完整组(与乙状窦游离)动物采用gadolinium(Gd)-DTPA-BMA增强MRI检测内淋巴积水.结果由于Gd-DTPA-BMA主要进入鼓阶和前庭阶,耳蜗的三个阶可在所有动物中由MRI清晰显示.在内淋巴囊完整组,内淋巴囊手术后6天MRI即可检测到内淋巴积水,并且由组织学证实.在内淋巴囊破坏组中的1只动物,因内耳屏障的严重破坏而使Gd-DTPA-BMA快速漏入中阶,MRI可检测到该变化,其听力损失为60dB.结论用Gd-DTPA-BMA增强的高分辨MRI可检测出内淋巴积水,有可能对积水程度进行定量测试.在Gd-DTPA-BMA的帮助下,内耳屏障损伤或可能的膜破裂可以被检出.

In vivo visualization of experimental endolymphatic hydrops in guinea pigs with 4.7 Tesla MRI

Objective To find out whether it is possible to visualize experimental endolymphatichydrops in the cochlea using magnetic resonance imaging (MRI) at 4.7 T. Methods Twenty albino orpigmented guinea pigs were used. Five normal guinea pigs were used as controls. Fifteen guinea pigswere subjected to procedures promoting endolymphatic hydrops. Five of 9 animals in the endolymphaticsac damaged group and 6 animals in the endolymphatic sac intact group (dissection from sigmoid sinus)were evaluated for endolymphatic hydrops using MRI with gadolinium (Gd)- DTPA- BMA contrast agent.Hearing was tested with electrocochleography. The surface area of three partitions of the cochlea wasused to quantify endolymphatic hydrops. Results The fine structure of the three partitions of the cochleawas visualized with MRI in all animals as Gd- DTPA- BMA appeared mainly in scala tympani andvestibuli. As early as 6 days after endolymphatic sac surgery, endolymphatic hydrops started to appear asvisualized by MRI and also verified with histology. Severe damage to the inner ear barrier with Gd-DTPA- BMA leakage into scala media was detected with MRI in one endolymphatic sac- damaged animalwhich had a 60 dB hearing loss. Conclusions Endolymphatic hydrops can be visualized with highresolution MRI by using Gd- DTPA- BMA and it is possible to quantify the extent of endolymphatichydrops. Damage to the inner ear barrier or possible rupture of membranes can be shown with theassistance of Gd- DTPA- BMA.