視神經管位於頭顱內的蝶骨小翼上，為眼球視神經通往顱腔的通道，也是眼動脈進入眼眶的必經位 置。視神經管的正常與否，關係到的不僅是頭顱骨本身，也牽動著相關神經與血管的問題。對於這個重要 結構，臨床上有不同的檢查選項，其中最為簡便，也可提供初步診治資料的，是採用X-光進行「頂骨-眼眶 斜位投射之視神經管成像」，此種放射攝影檢查亦稱為「Rhese Method」。經由此檢查技術，將視神經管清 楚且無失真的呈現於影像當中。本文以說明這些重要構造的基本解剖位置，並說明X-光投射通過結構路徑 投影的結果，最後分析不理想的影像結構呈現上的可能原因，讓醫事放射師在技術操作以及影像呈現上， 有更為專業判斷依據。

The optic canal is a hole in the lesser wing of the sphenoid bone that is located posteriorly at the apex of the cone-shaped orbit. This small hole allows for passage of the optic nerve and ophthalmic artery. The parietal-orbital oblique projection (Rhese Method) is one of the ways to demonstrate the optic canal clinically. It is very important that medical students and radiological technicians grasp the Rhese method and medical images about optic canal. First of all this article illustrates the basic dissection trend of the orbit and optic canal, then it explains the relationship between radiographic technique and anatomic structures. Finally we analyze the evaluation criteria of radiograph of the optic canal. According to these conceptions, we can improve the quality of the image of the optic canal.