@article{TaegerMuellerGraffLukasetal.2021,
  author    = {Taeger, Johannes and M{\"u}ller-Graff, Franz-Tassilo and Lukas, Ilgen and Schendzielorz, Philipp and Hagen, Rudolf and Neun, Tilman and Rak, Kristen},
  title     = {Cochlear duct length measurements in computed tomography and magnetic resonance imaging using newly developed techniques},
  series = {OTO Open},
  volume    = {5},
  journal   = {OTO Open},
  number    = {3},
  doi       = {10.1177/2473974X211045312},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-263922},
  pages     = {1-8},
  year      = {2021},
  abstract  = {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.},
  language  = {en}
}
@article{TaegerMuellerGraffNeunetal.2021,
  author    = {Taeger, Johannes and M{\"u}ller-Graff, Franz-Tassilo and Neun, Tilmann and K{\"o}ping, Maria and Schendzielorz, Philipp and Hagen, Rudolf and Rak, Kristen},
  title     = {Highly precise navigation at the lateral skull base by the combination of flat-panel volume CT and electromagnetic navigation},
  series = {Science Progress},
  volume    = {104},
  journal   = {Science Progress},
  number    = {3},
  issn      = {2047-7163},
  doi       = {10.1177/00368504211032090},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-250268},
  year      = {2021},
  abstract  = {This study aimed to evaluate the feasibility and accuracy of electromagnetic navigation at the lateral skull base in combination with flat panel volume computed tomography (fpVCT) datasets. A mastoidectomy and a posterior tympanotomy were performed on 10 samples of fresh frozen temporal bones. For registration, four self-drilling titanium screws were applied as fiducial markers. Multi-slice computed tomography (MSCT; 600 µm), conventional flat panel volume computed tomography (fpVCT; 466 µm), micro-fpVCT (197 µm) and secondary reconstructed fpVCT (100 µM) scans were performed and data were loaded into the navigation system. The resulting fiducial registration error (FRE) was analysed, and control of the navigation accuracy was performed. The registration process was very quick and reliable with the screws as fiducials. Compared to using the MSCT data, the micro-fpVCT data led to significantly lower FRE values, whereas conventional fpVCT and secondary reconstructed fpVCT data had no advantage in terms of accuracy. For all imaging modalities, there was no relevant visual deviation when targeting defined anatomical points with a navigation probe. fpVCT data are very well suited for electromagnetic navigation at the lateral skull base. The use of titanium screws as fiducial markers turned out to be ideal for comparing different imaging methods. A further evaluation of this approach by a clinical trial is required.},
  language  = {en}
}