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  - 
TY  - JOUR
A1  - Radeloff, Katrin
A1  - Ramos Tirado, Mario
A1  - Haddad, Daniel
A1  - Breuer, Kathrin
A1  - Müller, Jana
A1  - Hochmuth, Sabine
A1  - Hackenberg, Stephan
A1  - Scherzad, Agmal
A1  - Kleinsasser, Norbert
A1  - Radeloff, Andreas
T1  - Superparamagnetic iron oxide particles (VSOPs) show genotoxic effects but no functional impact on human adipose tissue-derived stromal cells (ASCs)
JF  - Materials
N2  - Adipose tissue-derived stromal cells (ASCs) represent a capable source for cell-based therapeutic approaches. For monitoring a cell-based application in vivo, magnetic resonance imaging (MRI) of cells labeled with iron oxide particles is a common method. It is the aim of the present study to analyze potential DNA damage, cytotoxicity and impairment of functional properties of human (h)ASCs after labeling with citrate-coated very small superparamagnetic iron oxide particles (VSOPs). Cytotoxic as well as genotoxic effects of the labeling procedure were measured in labeled and unlabeled hASCs using the MTT assay, comet assay and chromosomal aberration test. Trilineage differentiation was performed to evaluate an impairment of the differentiation potential due to the particles. Proliferation as well as migration capability were analyzed after the labeling procedure. Furthermore, the labeling of the hASCs was confirmed by Prussian blue staining, transmission electron microscopy (TEM) and high-resolution MRI. Below the concentration of 0.6 mM, which was used for the procedure, no evidence of genotoxic effects was found. At 0.6 mM, 1 mM as well as 1.5 mM, an increase in the number of chromosomal aberrations was determined. Cytotoxic effects were not observed at any concentration. Proliferation, migration capability and differentiation potential were also not affected by the procedure. Labeling with VSOPs is a useful labeling method for hASCs that does not affect their proliferation, migration and differentiation potential. Despite the absence of cytotoxicity, however, indications of genotoxic effects have been demonstrated.
KW  - ASCs
KW  - adipose tissue-derived stromal cells
KW  - VSOP
KW  - iron oxide nanoparticles
KW  - toxicity
KW  - MRI
KW  - cell labeling
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-222970
SN  - 1996-1944
VL  - 14
IS  - 2
ER  -