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Improving grazing-incidence small-angle X-ray scattering–computed tomography images by total variation minimization

Grazing-incidence small-angle X-ray scattering (GISAXS) coupled with computed tomography (CT) has enabled the visualization of the spatial distribution of nanostructures in thin films. 2D GISAXS images are obtained by scanning along the direction perpendicular to the X-ray beam at each rotation angl...

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Autores principales: Ogawa, Hiroki, Ono, Shunsuke, Nishikawa, Yukihiro, Fujiwara, Akihiko, Kabe, Taizo, Takenaka, Mikihito
Formato: Online Artículo Texto
Lenguaje:English
Publicado: International Union of Crystallography 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6998772/
https://www.ncbi.nlm.nih.gov/pubmed/32047408
http://dx.doi.org/10.1107/S1600576719016558
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author Ogawa, Hiroki
Ono, Shunsuke
Nishikawa, Yukihiro
Fujiwara, Akihiko
Kabe, Taizo
Takenaka, Mikihito
author_facet Ogawa, Hiroki
Ono, Shunsuke
Nishikawa, Yukihiro
Fujiwara, Akihiko
Kabe, Taizo
Takenaka, Mikihito
author_sort Ogawa, Hiroki
collection PubMed
description Grazing-incidence small-angle X-ray scattering (GISAXS) coupled with computed tomography (CT) has enabled the visualization of the spatial distribution of nanostructures in thin films. 2D GISAXS images are obtained by scanning along the direction perpendicular to the X-ray beam at each rotation angle. Because the intensities at the q positions contain nanostructural information, the reconstructed CT images individually represent the spatial distributions of this information (e.g. size, shape, surface, characteristic length). These images are reconstructed from the intensities acquired at angular intervals over 180°, but the total measurement time is prolonged. This increase in the radiation dosage can cause damage to the sample. One way to reduce the overall measurement time is to perform a scanning GISAXS measurement along the direction perpendicular to the X-ray beam with a limited interval angle. Using filtered back-projection (FBP), CT images are reconstructed from sinograms with limited interval angles from 3 to 48° (FBP-CT images). However, these images are blurred and have a low image quality. In this study, to optimize the CT image quality, total variation (TV) regularization is introduced to minimize sinogram image noise and artifacts. It is proposed that the TV method can be applied to downsampling of sinograms in order to improve the CT images in comparison with the FBP-CT images.
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spelling pubmed-69987722020-02-11 Improving grazing-incidence small-angle X-ray scattering–computed tomography images by total variation minimization Ogawa, Hiroki Ono, Shunsuke Nishikawa, Yukihiro Fujiwara, Akihiko Kabe, Taizo Takenaka, Mikihito J Appl Crystallogr Research Papers Grazing-incidence small-angle X-ray scattering (GISAXS) coupled with computed tomography (CT) has enabled the visualization of the spatial distribution of nanostructures in thin films. 2D GISAXS images are obtained by scanning along the direction perpendicular to the X-ray beam at each rotation angle. Because the intensities at the q positions contain nanostructural information, the reconstructed CT images individually represent the spatial distributions of this information (e.g. size, shape, surface, characteristic length). These images are reconstructed from the intensities acquired at angular intervals over 180°, but the total measurement time is prolonged. This increase in the radiation dosage can cause damage to the sample. One way to reduce the overall measurement time is to perform a scanning GISAXS measurement along the direction perpendicular to the X-ray beam with a limited interval angle. Using filtered back-projection (FBP), CT images are reconstructed from sinograms with limited interval angles from 3 to 48° (FBP-CT images). However, these images are blurred and have a low image quality. In this study, to optimize the CT image quality, total variation (TV) regularization is introduced to minimize sinogram image noise and artifacts. It is proposed that the TV method can be applied to downsampling of sinograms in order to improve the CT images in comparison with the FBP-CT images. International Union of Crystallography 2020-02-01 /pmc/articles/PMC6998772/ /pubmed/32047408 http://dx.doi.org/10.1107/S1600576719016558 Text en © Hiroki Ogawa et al. 2020 http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.http://creativecommons.org/licenses/by/4.0/
spellingShingle Research Papers
Ogawa, Hiroki
Ono, Shunsuke
Nishikawa, Yukihiro
Fujiwara, Akihiko
Kabe, Taizo
Takenaka, Mikihito
Improving grazing-incidence small-angle X-ray scattering–computed tomography images by total variation minimization
title Improving grazing-incidence small-angle X-ray scattering–computed tomography images by total variation minimization
title_full Improving grazing-incidence small-angle X-ray scattering–computed tomography images by total variation minimization
title_fullStr Improving grazing-incidence small-angle X-ray scattering–computed tomography images by total variation minimization
title_full_unstemmed Improving grazing-incidence small-angle X-ray scattering–computed tomography images by total variation minimization
title_short Improving grazing-incidence small-angle X-ray scattering–computed tomography images by total variation minimization
title_sort improving grazing-incidence small-angle x-ray scattering–computed tomography images by total variation minimization
topic Research Papers
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6998772/
https://www.ncbi.nlm.nih.gov/pubmed/32047408
http://dx.doi.org/10.1107/S1600576719016558
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