Meer, Franziska van der

[["dc.bibliographiccitation.artnumber","013501"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Journal of Medical Imaging"],["dc.bibliographiccitation.volume","7"],["dc.contributor.author","Robisch, Anna Lena"],["dc.contributor.author","Eckermann, Marina"],["dc.contributor.author","Töpperwien, Mareike"],["dc.contributor.author","Meer, Franziska van der"],["dc.contributor.author","Stadelmann-Nessler, Christine"],["dc.contributor.author","Salditt, Tim"],["dc.date.accessioned","2020-03-04T13:21:36Z"],["dc.date.available","2020-03-04T13:21:36Z"],["dc.date.issued","2020"],["dc.description.abstract","X-ray cone-beam holotomography of unstained tissue from the human central nervous system reveals details down to subcellular length scales. This visualization of variations in the electron density of the sample is based on phase-contrast techniques using intensities formed by self-interference of the beam between object and detector. Phase retrieval inverts diffraction and overcomes the phase problem by constraints such as several measurements at different Fresnel numbers for a single projection. Therefore, the object-to-detector distance (defocus) can be varied. However, for cone-beam geometry, changing defocus changes magnification, which can be problematic in view of image processing and resolution. Alternatively, the photon energy can be altered (multi-E). Far from absorption edges, multi-E data yield the wavelength-independent electron density. We present the multi-E holotomography at the Göttingen Instrument for Nano-Imaging with X-Rays (GINIX) setup of the P10 beamline at Deutsches Elektronen-Synchrotron. The instrument is based on a combined optics of elliptical mirrors and an x-ray waveguide positioned in the focal plane for further coherence, spatial filtering, and high numerical aperture. Previous results showed the suitability of this instrument for nanoscale tomography of unstained brain tissue. We demonstrate that upon energy variation, the focal spot is stable enough for imaging. To this end, a double-crystal monochromator and automated alignment routines are required. Three tomograms of human brain tissue were recorded and jointly analyzed using phase retrieval based on the contrast transfer function formalism generalized to multiple photon energies. Variations of the electron density of the sample are successfully reconstructed."],["dc.identifier.doi","10.1117/1.JMI.7.1.013501"],["dc.identifier.pmid","32016134"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/63102"],["dc.identifier.url","https://mbexc.uni-goettingen.de/literature/publications/20"],["dc.language.iso","en"],["dc.relation","EXC 2067: Multiscale Bioimaging"],["dc.relation.issn","2329-4302"],["dc.relation.orgunit","Institut für Röntgenphysik"],["dc.relation.workinggroup","RG Salditt (Structure of Biomolecular Assemblies and X-Ray Physics)"],["dc.relation.workinggroup","RG Stadelmann-Nessler"],["dc.subject.gro","x-ray imaging"],["dc.subject.gro","biomedical tomography"],["dc.title","Nanoscale x-ray holotomography of human brain tissue with phase retrieval based on multienergy recordings"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.subtype","original_ja"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1"],["dc.bibliographiccitation.issue","01"],["dc.bibliographiccitation.journal","Journal of Medical Imaging"],["dc.bibliographiccitation.volume","7"],["dc.contributor.author","Eckermann, Marina"],["dc.contributor.author","Töpperwien, Mareike"],["dc.contributor.author","Robisch, Anna Lena"],["dc.contributor.author","Meer, Franziska van der"],["dc.contributor.author","Stadelmann-Nessler, Christine"],["dc.contributor.author","Salditt, Tim"],["dc.date.accessioned","2020-03-03T08:42:36Z"],["dc.date.available","2020-03-03T08:42:36Z"],["dc.date.issued","2020"],["dc.description.abstract","Purpose: Recently, progress has been achieved in implementing phase-contrast tomography of soft biological tissues at laboratory sources. This opens up opportunities for three-dimensional (3-D) histology based on x-ray computed tomography (μ- and nanoCT) in the direct vicinity of hospitals and biomedical research institutions. Combining advanced x-ray generation and detection techniques with phase reconstruction algorithms, 3-D histology can be obtained even of unstained tissue of the central nervous system, as shown, for example, for biopsies and autopsies of human cerebellum. Depending on the setup, i.e., source, detector, and geometric parameters, laboratory-based tomography can be implemented at very different sizes and length scales. We investigate the extent to which 3-D histology of neuronal tissue can exploit the cone-beam geometry at high magnification M using a nanofocus transmission x-ray tube (nanotube) with a 300 nm minimal spot size (Excillum), combined with a single-photon counting camera. Tightly approaching the source spot with the biopsy punch, we achieve high M  ≈  101  −  102, high flux density, and exploit the superior efficiency of this detector technology. Approach: Different nanotube configurations such as spot size and flux, M, as well as exposure time, Fresnel number, and coherence are varied and selected in view of resolution, field of view, and/or phase-contrast requirements. Results: The data show that the information content for the cytoarchitecture is enhanced by the phase effect. Comparison of results to those obtained at a microfocus rotating-anode x-ray tomography setup with a high-resolution detector, i.e., in low-M geometry, reveals similar to slightly superior data quality for the nanotube setup. In addition to its compactness, reduced power consumption by a factor of 103, and shorter scan duration, the particular advantage of the nanotube setup also lies in its suitability for pixel detector technology, enabling an increased range of opportunities for applications in laboratory phase-contrast x-ray tomography. Conclusions: The phase retrieval scheme utilized mixes amplitude and phase contrast, with results being robust with respect to reconstruction parameters. Structural information content is comparable to slightly superior to previous results achieved with a microfocus rotating-anode setup but can be obtained in shorter scan time. Beyond advantages as compactness, lowered power consumption, and flexibility, the nanotube setup’s scalability in view of the progress in pixel detector technology is particularly beneficial. Further progress is thus likely to bring 3-D virtual histology to the performance in scan time and throughput required for clinical practice in neuropathology."],["dc.identifier.doi","10.1117/1.JMI.7.1.013502"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/63074"],["dc.identifier.url","https://mbexc.uni-goettingen.de/literature/publications/23"],["dc.language.iso","en"],["dc.relation","EXC 2067: Multiscale Bioimaging"],["dc.relation.issn","2329-4302"],["dc.relation.orgunit","Institut für Röntgenphysik"],["dc.relation.workinggroup","RG Salditt (Structure of Biomolecular Assemblies and X-Ray Physics)"],["dc.relation.workinggroup","RG Stadelmann-Nessler"],["dc.subject.gro","x-ray imaging"],["dc.subject.gro","biomedical tomography"],["dc.title","Phase-contrast x-ray tomography of neuronal tissue at laboratory sources with submicron resolution"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.subtype","original_ja"],["dspace.entity.type","Publication"]]