Establishment Of Normative Cochlea Measurements On HRCT Imagings To Aid In The Dignosis Of Cochlea Hypoplasia

Objective:To reconstruct the standard position images of cochlea using multi-planar reformation (MPR) of high resolution computed tomography (HRCT) and establish normative measurements of cochlea on standard position images to aid in the diagnosis of cochlea hypolasia. Methods:HRCT scanning of temporal bone was undergone in 50 volunteers (100 ears) with normal hearing and without any disease in the middle and inner ear. The images of all cases were postprocessed using MPR . Two standard position images (positionI and II) were renconstructed and the rate of the images showing were calculated. 9 structures of cochlea (named A-I) were measured on the images of position I andII ,including upper hemicycile width of Basal turn, lower hemicycle width of Middle turn, Middle turn height, Cochlea height, Modiolus area, length and width of Cochlea Nerve Canal on image I and Basal turn diameter, Basal turn lumen on image II. Statistical analysis was done on different age groups, male and female groups, left and right groups with SPSS program. Normative data of 9 measurements were established. 9 measurements of cochlea were also done in 42 cases (78 ears) which were diagnosed as "normal" on initial visual inspection. The data were compared with normal group. All cases of abnormal cochlear measurements were reviewed and analysed their characteristics.