gms | German Medical Science

Background: Digital Volume Tomography (DVT) is an advancement of panoramic tomography used in dentistry. It is based on the principles of rotational tomography and enables high resolution of osseus structures. It was the aim of the study to evaluate the position of the electrode array after cochlea implantation.

Patients and methods: Postoperative control was performed in 31 patients using DVT (F17, Morita, Kyoto, Japan). By the use of special algorhythms for reconstruction and processing it was possible to evaluate the electrode arrays concerning to their position either in the scala tympani or in the scala vestibuli. Other options were switches from one scala to the other. For this purpose the cochlea was uncurled using a panoramic tool. Additionally orthogonal cross sections to the longitudinal axis of the cochlea were performed.

Results: Via these applications it was possible to localise the intracochlear position of the electrode arrays in 25 patients precisely. In 13 patients the electrode could be detected in the scala tympani, in 7 patients in the scala vestibuli. In 5 patients a switch from scala tympani to scala vestibuli occurred. In another 6 patients an exact intracochleäre localisation was impossible because of motion artefacts.

Summary: Digital Volume Tomography is a suitable diagnostic modality for the evaluation of the cochlear without artefacts caused by foreign bodies after implantation of an electrode array. By the use of special reconstruction algorhythms it is possible to analyse the intracochlear position of these electrodes. These additional investigations do not lead to additive radiation exposure, but serve as a valuable tool to advance surgical approaches to the cochlea.