Edamatsu H, Yamashita K
Department of Otorhinolaryngology, Kanazawa Medical University, Ishikawa.
Nihon Jibiinkoka Gakkai Kaiho. 1995 Feb;98(2):245-53. doi: 10.3950/jibiinkoka.98.245.
This study was performed to evaluate the usefulness and limitations of three-dimensional (3-D) imaging of the ossicular chain in the middle ear by high speed helical CT. One dissected human temporal bone, five normal ears, and twelve diseased ears (trauma, ossicular anomaly, cholesteatoma, chronic otitis media) were scanned in 1.0mm slices and reconstructed at a thickness of 0.2-0.5mm. All 3-D CT specimens can be observed in any plane and from any direction. Ossicular 3-D CT temporal bone images were reconstructed as if the malleus, incus and stapes were being observed under a microscope. No defect in the ossicles or their joints was seen in the images. The entire structure of the stapes could not be represented by conventional two-dimensional CT, but the 3-D CT in our study showed the head, crus and foot plate of the stapes in detail. Ossicular 3-D CT images of normal ears yielded the same findings as those recorded in the temporal bone. Preoperative diagnostic findings of ossicles in diseased ears were very useful. 3-D CT was diagnostic and its accuracy was confirmed by surgical observations, especially in ossicular anomalies. 3-D CT was also an important method of postoperative evaluation of ossicular reconstruction, i.e. TORP and PORP. It could represent the anatomical relation between prosthesis and the oval window. Postoperative hearing improvement can be compared with 3-D CT findings. High-speed helical CT can scan an object more quickly and clearly than conventional CT, and its biological damage in humans is less than that of other methods.
本研究旨在评估通过高速螺旋CT对中耳听骨链进行三维（3-D）成像的实用性和局限性。对1例解剖后的人颞骨、5只正常耳和12只患病耳（外伤、听骨异常、胆脂瘤、慢性中耳炎）进行扫描，层厚1.0mm，并以0.2 - 0.5mm的厚度进行重建。所有3-D CT标本均可在任何平面和任何方向进行观察。听骨链的3-D CT颞骨图像重建后就如同在显微镜下观察锤骨、砧骨和镫骨一样。图像中未见听骨及其关节有缺损。传统二维CT无法完整显示镫骨的结构，但本研究中的3-D CT详细显示了镫骨的头部、脚和底板。正常耳的听骨链3-D CT图像与颞骨记录的结果一致。患病耳听骨的术前诊断结果非常有用。3-D CT具有诊断价值，其准确性经手术观察得以证实，尤其是在听骨异常方面。3-D CT也是听骨重建术后评估的重要方法，即全听骨赝复物（TORP）和部分听骨赝复物（PORP）。它可以显示假体与卵圆窗之间的解剖关系。术后听力改善情况可与3-D CT结果进行比较。高速螺旋CT比传统CT能更快、更清晰地扫描物体，并且其对人体的生物损伤比其他方法更小。
