Mashima Y, Oshitari K, Imamura Y, Momoshima S, Shiga H, Oguchi Y
Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan.
Arch Ophthalmol. 1996 Oct;114(10):1197-203. doi: 10.1001/archopht.1996.01100140397006.
To evaluate the orbital portion of the optic nerve and the subarachnoid space using fast spin-echo magnetic resonance imaging in normal subjects and in patients with papilledema or optic atrophy.
Measurements of the optic nerve complex on coronal images were made using high-resolution magnetic resonance imaging with fast spin-echo sequences.
Twenty-one patients, including 5 patients with papilledema due to congenital hydrocephalus, intracranial tumors, or meningitis, as well as 16 patients with optic atrophy, were studied. Sixteen healthy volunteers served as controls.
The longitudinal diameter of the optic nerve, the longitudinal outer diameter of the subarachnoid space, the diameter ratio, and the area of the subarachnoid space were determined.
In normal subjects, the ring-shaped area of high signal intensity that represented the subarachnoid space was widest behind the globe, then narrowed toward the orbital apex. In patients with papilledema, the area of the subarachnoid space was markedly dilated, the optic nerve was compressed, and the nerve sheath was widened, resulting in a small diameter ratio compared with that of controls. Patients with pallor of the temporal aspect of the optic disc appeared to exhibit dilation of the subarachnoid space; the size of the optic nerve was decreased more than that of the nerve sheath, resulting in a small diameter ratio compared with controls. Patients with complete pallor of the disc, however, exhibited hyperintense optic nerve complexes without a ring-shaped appearance toward the orbital apex.
Fast spin-echo magnetic resonance imaging appears useful for objectively evaluating the optic nerve and surrounding subarachnoid space in patients with papilledema and optic atrophy.
利用快速自旋回波磁共振成像评估正常受试者、视乳头水肿患者或视神经萎缩患者的视神经眶内段及蛛网膜下腔。
使用带有快速自旋回波序列的高分辨率磁共振成像对冠状位图像上的视神经复合体进行测量。
研究了21例患者，包括5例因先天性脑积水、颅内肿瘤或脑膜炎导致视乳头水肿的患者以及16例视神经萎缩患者。16名健康志愿者作为对照。
测定视神经的纵向直径、蛛网膜下腔的纵向外径、直径比以及蛛网膜下腔的面积。
在正常受试者中，代表蛛网膜下腔的高信号强度环形区域在眼球后方最宽，然后向眶尖变窄。在视乳头水肿患者中，蛛网膜下腔面积明显扩张，视神经受压，神经鞘增宽，与对照组相比直径比变小。视盘颞侧苍白的患者似乎表现出蛛网膜下腔扩张；视神经的大小比神经鞘减小得更多，与对照组相比直径比变小。然而，视盘完全苍白的患者表现为视神经复合体呈高强度信号，向眶尖无环形外观。
快速自旋回波磁共振成像似乎有助于客观评估视乳头水肿和视神经萎缩患者的视神经及周围蛛网膜下腔。
