Counter S Allen, Nikkhou Sahar, Brené Stefan, Damberg Peter, Sierakowiak Adam, Klason Tomas, Berglin Cecilia Engmér, Laurell Göran
Neurology Department, Harvard University Biological Laboratories, Cambridge, MA 02138,USA.
Open Neuroimag J. 2013 Jun 28;7:27-31. doi: 10.2174/1874440001307010027. Print 2013.
Previous in vivo experimental magnetic resonance imaging (MRI) investigations of the mammalian inner ear at 4.7 Tesla have indicated that intravenously injected gadolinium (Gd) penetrates the perilymphatic labyrinth, but not the endolymphatic membranous labyrinth. In the present study, high field MRI at 9.4T was used to visualize the in vivo mouse vestibulo-cochlea system, and to determine whether the endolymphatic system is permeable to a Gd complex.
A 9.4 T Varian magnet equipped with a 12 cm inner diameter gradient system with maximum gradient strength of 600 mT/m, a millipede coil (Varian design) and a Gd contrast agent were used for image acquisition in the normal C57 BL-6 mouse.
High-resolution 2D and 3D images of the mouse cochlea were acquired within 80 minutes following intravenous injection of Gd. Gd initially permeated the perilymphatic scala tympani and scala vestibuli, and permitted visualization of both cochlear turns from base to apex. The superior, inferior and lateral semicircular canals were subsequently visualized in 3 planes. The membranous endolymphatic labyrinth was impermeable to intravenously injected Gd, and thus showed no apparent uptake of Gd at 9.4T.
The 9.4T field strength MRI permitted acquisition of high resolution images of anatomical and physiological features of the normal, wild type mouse perilymphatic inner ear in vivo, and provided further evidence that the endolymphatic system is impermeable to intravenously injected Gd.
先前在4.7特斯拉场强下对哺乳动物内耳进行的体内实验性磁共振成像（MRI）研究表明，静脉注射钆（Gd）可穿透外淋巴迷路，但不能穿透内淋巴膜迷路。在本研究中，使用9.4T的高场MRI来观察活体小鼠的前庭 - 耳蜗系统，并确定内淋巴系统是否可渗透钆复合物。
使用配备内径为12 cm、最大梯度强度为600 mT/m的梯度系统、千足线圈（Varian设计）和钆造影剂的9.4T Varian磁体，对正常C57 BL - 6小鼠进行图像采集。
静脉注射钆后80分钟内获得了小鼠耳蜗的高分辨率二维和三维图像。钆最初渗透到外淋巴鼓阶和前庭阶，并能从基部到顶部观察到两个耳蜗螺旋。随后在三个平面上观察到上、下和外侧半规管。静脉注射的钆不能穿透膜性内淋巴迷路，因此在9.4T时未显示出明显的钆摄取。
9.4T场强的MRI能够在体内获取正常野生型小鼠外淋巴内耳解剖和生理特征的高分辨率图像，并进一步证明内淋巴系统对静脉注射的钆是不可渗透的。
