In vivo measures of cochlear length and insertion depth of nucleus cochlear implant electrode arrays

Three-dimensional cochlear canal lengths, electrode array intracochlear insertion depths, and characteristic frequency ranges were estimated for 20 Nucleus implant recipients on the basis of in vivo computed tomography (CT) scans. Ultra-high resolution images were reconstructed from spiral CT data w...

Full description

Saved in:
Bibliographic Details
Published inAnnals of otology, rhinology & laryngology. Supplement Vol. 175; p. 1
Main Authors Ketten, D R, Skinner, M W, Wang, G, Vannier, M W, Gates, G A, Neely, J G
Format Journal Article
LanguageEnglish
Published United States 01.11.1998
Subjects
Adult
Aged
Aged, 80 and over
Cochlea - anatomy & histology
Cochlear Implantation - methods
Cochlear Nucleus - physiology
Deafness - rehabilitation
Electrodes, Implanted
Female
Humans
Male
Middle Aged
Online AccessGet more information

Cover

More Information
Summary:Three-dimensional cochlear canal lengths, electrode array intracochlear insertion depths, and characteristic frequency ranges were estimated for 20 Nucleus implant recipients on the basis of in vivo computed tomography (CT) scans. Ultra-high resolution images were reconstructed from spiral CT data with 0.1-mm slicing and expanded attenuation scales. Canal length estimates (mean 33.01 mm; SD 2.31) were consistent with previous findings for normal human temporal bones. Intracochlear array insertion depths estimated by 3-dimensional (3-D) spiral calculations (mean 20.19 mm; SD 2.86) and by a computerized array tracking algorithm (mean 20.36 mm; SD 2.66) were not significantly different. Estimates from surgical observations were significantly longer (mean 21.03 mm; SD 2.31) because array compressions were not detectable. Characteristic frequencies at apical electrodes estimated from Greenwood's equations ranged from 387 Hz to 2,596 Hz. The results show that significant variations in cochlear anatomy and array distribution among implant patients that may impact implant performance can be reliably detected and quantified by using in vivo high-resolution CT and 3-D reconstructions.
ISSN:0096-8056