TY  - JOUR
A1  - Taeger, Johannes
A1  - Müller-Graff, Franz-Tassilo
A1  - Lukas, Ilgen
A1  - Schendzielorz, Philipp
A1  - Hagen, Rudolf
A1  - Neun, Tilman
A1  - Rak, Kristen
T1  - Cochlear duct length measurements in computed tomography and magnetic resonance imaging using newly developed techniques
JF  - OTO Open
N2  - Objective
Growing interest in measuring the cochlear duct length (CDL) has emerged, since it can influence the selection of cochlear implant electrodes. Currently the measurements are performed with ionized radiation imaging. Only a few studies have explored CDL measurements in magnetic resonance imaging (MRI). Therefore, the presented study aims to fill this gap by estimating CDL in MRI and comparing it with multislice computed tomography (CT).

Study Design
Retrospective data analyses of 42 cochleae.

Setting
Tertiary care medical center.

Methods
Diameter (A value) and width (B value) of the cochlea were measured in HOROS software. The CDL and the 2-turn length were determined by the elliptic circular approximation (ECA). In addition, the CDL, the 2-turn length, and the angular length were determined via HOROS software by the multiplanar reconstruction (MPR) method.

Results
CDL values were significantly shorter in MRI by MPR (d = 1.38 mm, P < .001) but not by ECA. Similar 2-turn length measurements were significantly lower in MRI by MPR (d = 1.67 mm) and ECA (d = 1.19 mm, both P < .001). In contrast, angular length was significantly higher in MRI (d = 26.79°, P < .001). When the values were set in relation to the frequencies of the cochlea, no clinically relevant differences were estimated (58 Hz at 28-mm CDL).

Conclusion
In the presented study, CDL was investigated in CT and MRI by using different approaches. Since no clinically relevant differences were found, diagnostics with radiation may be omitted prior to cochlear implantation; thus, a concept of radiation-free cochlear implantation could be established.
KW  - CDL
KW  - cochlear implantation
KW  - temporal bone
KW  - CT
KW  - MRI
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-263922
VL  - 5
IS  - 3
ER  -