側頭骨病変に対する超高分解能CTの臨床応用

Clinical Application of High Resolution Computed Tomography of Temporal Bone Diseases

　通常行われているCTスキャンでは側頭骨の細部の所見は不明である。しかし近年，高空間分解能特性をもつCTが開発され，その側頭骨病変への応用はもはや時間の問題となった。

　現在までこの機能をもつCTに関する報告としては聴神経腫瘍を中心としたものが散見されるが^3,8），中耳，内耳病変に関する詳細な報告はみあたらない。

　Using CT/T 8800 with high spatial resolution, target imaging of the various temporal bone diseases was performed. Coronal and axial scans were made. Target imaging is an effective means of studying patients with cholesteatomas, semicircular canal fistula, diseases of the internal auditory canal (acoustic neuroma, or stenosis) and inner ear anomaly (hypoplasia, or distension of the vestibulum).

　The results of the comparison of CT and polytomography of the temporal bone were as follows: 1. In most cases, the pathological process was demonstrated with CT scans better than or same as with polytomograms. 2. The radiation dose of CT scan is low. 3. The axial images of the temporal bone were easily obtained with CT. 4. CT is more effective than polytomography in the diagnosis and evaluation of the temporal bone involved by tumor and cholesteatoma, especially attic cholesteatoma. 5. In cases with temporal bone fracture, acoustic neuroma or other intracranial diseases, contrast-enhanced CT can be done.