[Research of cochlear coiling pattern and orientation in general population by CT 3D reconstruction]

To perform morphometric analysis of bilateral cochleae in all subjects based on computed 3-dimensional reconstruction tomographic data and assist the surgeon in diagnosing the inner ear abnormality or surgical strategies.

Two hundred normal developed cochleae from 100 patients were divided into 5 groups according to age. Morphometric analysis of bilateral cochleae was performed in all subjects by 3D reconstructions and 2D multiplanar reformation. The length and width of the cochlear base, the length within the cochlear base, the height of the cochlea, the angle between the first and second turn of the cochlea, and the cochlear orientation within the cranial base were measured and compared in different age, sex and bilateral groups.

The length of the cochlear base was (8.56 +/- 0.52)mm, the width was (6.63 +/- 0.56)mm, the length within the cochlear base was (7.33 +/- 10.56)mm, the height of the cochlea was (3.76 +/- 0.28)mm, and the angle between the first and second turn of the cochlea was (15.82 +/- 2.78)degrees. All index above did not change significantly in different aging, sex or side (P > 0. 05). Variability in the angle between the first and second turn of the cochlea was considerable, and a smaller angle (from the midsagittal line) was showed in the older age groups than the younger groups (P < 0.05).

3D and 2D volume rendering enables us to evaluate the features of cochlear morphology and orientation that may assist the surgeon in diagnosing the inner ear abnormality or surgical strategies.