A novel micro computed tomography (μCT) image processing method was implemented to measure
anatomical features of the gerbil and chinchilla cochleas, taking into account the bent modailosis axis.
Measurements were made of the scala vestibule (SV) area, the scala tympani (SV) area, and the basilar
membrane (BM) width using prepared cadaveric temporal bones. 3-D cochlear structures were obtained
from the scanned images using a process described in this study. It was necessary to consider the sharp
curvature of mododailosis axis near the basal region. The SV and ST areas were calculated from the μCT
reconstructions and compared with existing data obtained by Magnetic Resonance Microscopy (MRM),
showing both qualitative and quantitative agreement. In addition to this, the width of the BM, which is the
distance between the primary and secondary osseous spiral laminae, is calculated for the two animals and
compared with previous data from the MRM method. For the gerbil cochlea, which does not have much
cartilage in the osseous spiral lamina, the μCT-based BM width measurements show good agreement with
previous data. The chinchilla BM, which contains more cartilage in the osseous spiral lamina than the
gerbil, shows a large difference in the BM widths between the μCT and MRM methods. The SV area, ST
area, and BM width measurements from this study can be used in building an anatomically based
mathematical cochlear model.