We present a method for obtaining a complete geometry model of the fluid chambers of cochlea (scalae) from tomography images. An accurate segmentation of cochlea is problematic due to the low contrast of the inner membranes of scalae. Our method of 3D segmentation is based on dynamic resampling of an original image stack to achieve a perpendicular cross-section of the scalae on all sections. Subsequently, perpendicular cross-section is being segmented using 2D active contours. The center of mass of the contour is extracted and used to predict further course of scalae centerline by Kalman filter. Cross-section contours are subsequently assembled to the total geometry model. This method has been applied to CT images, but we expect that it could be used for segmentation of strongly curved low-contrast tubular objects recorded with other tomography techniques.