内耳的解剖及MR表现ppt课件.pptVIP

内耳的解剖及MR表现;一、解剖;;骨迷路;; 前庭（vestibule)：位于骨迷路中部的 空腔，内藏膜迷路的椭圆囊和球囊； 上壁：面神经迷路段跨越； 下壁：骨壁； 内壁：内耳道底的一部分； 外壁：鼓室的内壁。 ;骨半规管（bony semicircular canals) : 为三个C形的互成直角排列的小管外骨半规管（水平）；上骨半规管（上垂直）；后骨半规管（后垂直）；;;耳蜗;;膜迷路;1、椭圆囊和球囊;;;2、膜半规管(membranous semicircular canal);;3、蜗管(cochlear duct);;;二、MRI 表现;人工电子耳蜗植入术前MRI检查;MRI的T2WI对脑脊液和神经纤维有良好的对比性，可以清晰的显示这些神经结构，是术前人工耳蜗植入的重要参考指标。此外，MRI可以显示内耳膜迷路，对排除耳蜗骨化以及迷路炎有重要意义，是保证人工电子耳蜗顺利植入的必备条件之一。;;3D FSE T2WI内耳道脑脊液为高信号，脑脊液中间可见神经呈线状低信号。;;;;内淋巴囊扩大 ;Figure A : The anatomy of the normal right inner ear, viewed from above and behind the temporal bone. The endolymphatic duct (arrow) courses through the proximal bony vestibula aqueduct from its internal aperture in the anteromedial wall of the vestibule to the endolymphatic sac (S) found in the bony aqueduct and within a shallow impression on the posterior face of the petrous temporal bone.;Figure B : Drawing from the same vantage point as in A depicts an enlarged right endolymphatic duct and sac. The endolymphatic duct (arrow) and the bony channel through which it courses (vestibular aqueduct) are enlarged. The endolymphatic sac (S), which lies within the distal aqueduct and between the leaves of the dura along the posterior aspect of the petrous pyramid, is also enlarged.;;谢 谢！