TY  - JOUR
A1  - Dittmann, Jonas
A1  - Balles, Andreas
A1  - Zabler, Simon
T1  - Optimization based evaluation of grating interferometric phase stepping series and analysis of mechanical setup instabilities
JF  - Journal of Imaging
N2  - The diffraction contrast modalities accessible by X-ray grating interferometers are not imaged directly but have to be inferred from sine-like signal variations occurring in a series of images acquired at varying relative positions of the interferometer’s gratings. The absolute spatial translations involved in the acquisition of these phase stepping series usually lie in the range of only a few hundred nanometers, wherefore positioning errors as small as 10 nm will already translate into signal uncertainties of 1–10% in the final images if not accounted for. Classically, the relative grating positions in the phase stepping series are considered input parameters to the analysis and are, for the Fast Fourier Transform that is typically employed, required to be equidistantly distributed over multiples of the gratings’ period. In the following, a fast converging optimization scheme is presented simultaneously determining the phase stepping curves’ parameters as well as the actually performed motions of the stepped grating, including also erroneous rotational motions which are commonly neglected. While the correction of solely the translational errors along the stepping direction is found to be sufficient with regard to the reduction of image artifacts, the possibility to also detect minute rotations about all axes proves to be a valuable tool for system calibration and monitoring. The simplicity of the provided algorithm, in particular when only considering translational errors, makes it well suitable as a standard evaluation procedure also for large image series.
KW  - X-ray imaging
KW  - Talbot–Lau interferometer
KW  - grating interferometer
KW  - phase contrast imaging
KW  - darkfield imaging
KW  - phase stepping
KW  - optimization
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-197723
SN  - 2313-433X
VL  - 4
IS  - 6
ER  - 
TY  - JOUR
A1  - Vogel, Patrick
A1  - Markert, Jonathan
A1  - Rückert, Martin A.
A1  - Herz, Stefan
A1  - Keßler, Benedikt
A1  - Dremel, Kilian
A1  - Althoff, Daniel
A1  - Weber, Matthias
A1  - Buzug, Thorsten M.
A1  - Bley, Thorsten A.
A1  - Kullmann, Walter H.
A1  - Hanke, Randolf
A1  - Zabler, Simon
A1  - Behr, Volker C.
T1  - Magnetic Particle Imaging meets computed tomography: first simultaneous imaging
JF  - Scientific Reports
N2  - Magnetic Particle Imaging (MPI) is a promising new tomographic modality for fast as well as three-dimensional visualization of magnetic material. For anatomical or structural information an additional imaging modality such as computed tomography (CT) is required. In this paper, the first hybrid MPI-CT scanner for multimodal imaging providing simultaneous data acquisition is presented.
KW  - Applied physics
KW  - Biomedical engineering
KW  - Imaging techniques
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-202501
VL  - 9
ER  - 
TY  - JOUR
A1  - Noyalet, Laurent
A1  - Ilgen, Lukas
A1  - Bürklein, Miriam
A1  - Shehata-Dieler, Wafaa
A1  - Taeger, Johannes
A1  - Hagen, Rudolf
A1  - Neun, Tilmann
A1  - Zabler, Simon
A1  - Althoff, Daniel
A1  - Rak, Kristen
T1  - Vestibular aqueduct morphology and Meniere’s disease - development of the vestibular aqueduct score by 3D analysis
JF  - Frontiers in Surgery
N2  - Improved radiological examinations with newly developed 3D models may increase understanding of Meniere's disease (MD). The morphology and course of the vestibular aqueduct (VA) in the temporal bone might be related to the severity of MD. The presented study explored, if the VA of MD and non-MD patients can be grouped relative to its angle to the semicircular canals (SCC) and length using a 3D model. Scans of temporal bone specimens (TBS) were performed using micro-CT and micro flat panel volume computed tomography (mfpVCT). Furthermore, scans were carried out in patients and TBS by computed tomography (CT). The angle between the VA and the three SCC, as well as the length of the VA were measured. From these data, a 3D model was constructed to develop the vestibular aqueduct score (VAS). Using different imaging modalities it was demonstrated that angle measurements of the VA are reliable and can be effectively used for detailed diagnostic investigation. To test the clinical relevance, the VAS was applied on MD and on non-MD patients. Length and angle values from MD patients differed from non-MD patients. In MD patients, significantly higher numbers of VAs could be assigned to a distinct group of the VAS. In addition, it was tested, whether the outcome of a treatment option for MD can be correlated to the VAS.
KW  - vestibular aqueduct (VA)
KW  - 3D analysis
KW  - temporal bone
KW  - saccotomy
KW  - computed tomography
KW  - Meniere’s disease
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-312893
SN  - 2296-875X
VL  - 9
ER  -