摘要
顳骨骨折經常造成聽力及顏面神經的受損，因此，對於顳骨內的結構正確的評估是非重要的。普通頭骨X光攝影對於顳骨骨折的敏感度僅在17％到30％之間，而方向斷層攝影檢查法（Pluridirectional Tomography）又需要較高七幅射劑量。至於磁振造影方面，因在顳骨裡的硬骨及氣室皆無訊號產生，故易造成假的聽小骨脫位並常掩蓋了真正體折的地方。目前高解析電腦斷層（High Resolution Computed Tomography, HRCT）在診斷顳骨骨折，聽小骨移位及軟組織受傷的情形，仍是最佳的利器。本文章的目的在於比較軸狀及冠狀兩個不同切面對於使用HRCT檢查顳骨結構的優缺點。自87年7月到88年3月共有九位自願受試者，接受高解析度電腦斷層查，其中包括六位男性，三位女性，平均年齡為35歲。所使用的切面角度（以硬顎為基準）包括23度（軸為切面）及105度（完狀切面）。我們針對兩不同切面角度評估顳骨內部結構的清晰與否加以分析。整體而言，軸位及完狀切面並沒有太大差異，不過在聽小骨鏈的部分如砧骨的豆狀突（incus lenticular process）及短突（incus short process）及鎚骨砧骨關節（malleoincular articulation）在軸切面優於冠狀切面，反之，冠狀切面對於砧骨的長突（incus long process）、鐙骨（stapes）及享骨鐙骨關節（incudostapedial articulation）較為清晰。利宆高解析電腦斷層在評估不同型式的顳骨骨折及相關的合併症非常有效，它亦可提供手術矯正所需的重要資料。我們的結論是針對準確度而言，軸位與冠狀切面並沒有很大差別，然而就判讀醫師對影像解剖的熟悉度、病人舒適度、影像品質而論，軸位切面優於冠狀切面。因此目前三總對於使用高解析電腦斷層來評估顳骨內部時乃軸狀切面（23度）為主，如不足時再加做冠狀切面（105度）。
並列摘要
Temporal bone fractures usually cause impairment of the 7^th and 8^th cranial nerves with resultant hearing loss and facial palsy. Therefore, knowledge of the anatomic structures within the temporal bone in detail becomes more and more important. High resolution computed tomography(HRCT) has been reported to be excellent in evaluating the bony and soft tissue of the temporal bone. The aim of this study is to compare the usefulness of HRCT in two different scanning planes in evaluation of the temporal bone structures. During a 9-month period, we examined nine volunteers (axial in 23 degrees and coronal in 105 degrees) were performed during each HRCT study of the temporal bone. Overall speaking, we found that there is no obvious difference of two examining planes with respect to the visualization of the anatomic structures of the temporal bone. However, structures like the lenticular process and short process of the incus and the malleoincular articulaiton are clearer indetified in the axial plane, while coronal plane is superior in demonstrating strctures like the long process of the incus, stapes, and the incudostapedial articulation. Axial plane is routine used in our hospital because of the familiarity of clinicians to the axial images, comfortablility of patients and better imaging quality. Conoral images are still important in giving supplemental information that is inadequate in axial images.