Normative Measurements of the Inner Ear Structures on Temporal Bone CT Images Using PACS

Goh, Eui Kyung; Park, Sung Hwan; Yoon, Bit Na; Lee, Il Woo; Roh, Hwan Jung; Chon, Kyong Myong; Kim, Hak Jin

Abstract

BACKGROUND AND OBJECTIVES
The reports of normative measurements for inner ear structure using computer-based programs are rare. The purpose of this study was to measure the normative data of the Korean inner ear structures and establish the basic data for diagnosis of congenital inner ear anomaly. SUBJECTS AND METHOD: Temporal bone CT of 38 patients (16 men and 22 women) without apparent disease of middle and inner ear, fractures or major disorder such as seizure or tumor were retrospectively reviewed. Fifteen dimensions on axial views and 9 dimensions on coronal views were measured in PACS using pi-view program. The slice thickness of CT was 0.6 mm. RESULTS: From the axial view, the canal diameter of SSCC was 1.09+/-0.15 mm, the bony island width was 5.70+/-0.50 mm, the bony island width of LSCC was 3.99+/-0.58 mm, the cochlear upper turn width & height were each 5.63+/-1.07 and 3.03+/-0.65 mm. The vestibular aqueduct were observed 95.3%. From the coronal view, the cochlear height was 5.14+/-0.36 mm. The length of IAC was significantly longer in male than female (p<0.05) and the opening site of IAC was significantly wider in the left than the right (p<0.05). The upper turn of cochlea in good bone conduction (< or =10 B) had larger width and smaller height than those in poor bone conduction (>10 dB). CONCLUSION: We established the Korean normative measurements of the inner ear structures, which can be used for further diagnosis of the inner ear anomaly.