|Budget Amount *help
¥1,000,000 (Direct Cost : ¥1,000,000)
Fiscal Year 1996 : ¥200,000 (Direct Cost : ¥200,000)
Fiscal Year 1995 : ¥800,000 (Direct Cost : ¥800,000)
Qualitative studies on computed tomography (CT) of the temporal bones in various ear diseases have been enormously carried out, however, quantitative CT studies such as distance and area of the temporal bones were scarce. Thus, we attempted to study degree of temporal bone development in various ear diseases such as bilateral Meniere's disease (n=13), unilateral Meniere's disease (n=41), otosclerosis (n=12) and unilateral chronic otitis media (n=25). For this study, we selected only one axial CT slice encompassing the lateral semicircular canal (LSC) from each side of each patient. Picture slides (35mm) of them were taken and collected. Digital images of them were obtained through a slide scanner, and the following various measurements were carried out using NIH image software ; (1) a distance between the posterior semicircular canal (PSC) and the posterior petrous surface (P-P distance), (2) a distance between the PSC and the LSC (P-L distance), (3) a distance between the vestibule and the posterior petrous surface (V-P distance), (4) a distance between the PSC and the anterior margin of the sigmoid sinus (P-S distance), (5) the area of the mastoid air cell system. The width of the posterior petrous bone (P-P and V-P distance) was shortest in bilateral Meniere's disease, followed by unilateral Meniere's disease, chronic otitis media and otosclerosis in that order. The area of the mastoid air cells were profoundly reduced in chronic otitis media, moderately in Meniere's disease of both bilateral and unilateral type. Otosclerosis showed the largest air cell development. Various degrees of temporal bone development in ear diseases such as Meniere's diasease and otosclerosis are inferred to result from virus infection to the temporal bone during infancy. It is necessary to detect virus gene in the ear, especially in the endolymphatic sac of Meniere's disease.