[The application of multi-slice CT three-dimensioned reconstruction in the cochlear implantation]

To evaluate the instructional effect of Multi-slice (MSCT) in the cochlear implantation pre- and post-operatively, and to contrast the image feature between the X-ray and the MSCT three-dimensional reconstruction of inner ear with implanted electrode.

Twenty-four cochlear implant (MEDEL Combi 40+) recipients,in No. 1 Hospital of China Medical University from January to October 2014, were involved in this study. Among them, 18 were male and 6 female,with an average age of 4 years. MSCT and three dimensional reconstruction of inner ear were performed in all of the 24 implanted inner ears pre- and post-operatively. And X-ray plain film were examined by using 60° lateral oblique position postoperatively. All data of the spiral CT scan with axial 1 mm image slices were transferred to workstation for three-dimensional reconstruction (direct volume rendering) of the inner ear.

In 1 of the 24 cases, preoperative three-dimensional reconstruction CT scan reveal that the length of the cochlear was shorter than the electrode. And this was confirmed by MSCT postoperatively that the electrode couldn't be inserted by full length. The insertion depth of the electrode can be evaluated directly by MSCT. Moreover, each of the electrode pairs can be identified clearly.

MSCT plays an indispensable role in the preoperative evaluation of cochlear implantation. Postoperative evaluation by three-dimensional reconstruction of inner ear provide more accurate image to show the electrode insertion depth in the cochlea. MSCT combined with curved planar reformation to measure cochlear length could provide guidance in choosing the more adaptive electrode. And MSCT is superior to DR in demonstration of electrode postoperatively.