Cargando…

Metal Artifact Reduction in Dental CBCT Images Using Direct Sinogram Correction Combined with Metal Path-Length Weighting

Metal artifacts in dental computed tomography (CT) images, caused by highly X-ray absorbing objects, such as dental implants or crowns, often more severely compromise image readability than in medical CT images. Since lower tube voltages are used for dental CTs in spite of the more frequent presence...

Descripción completa

Detalles Bibliográficos
Autores principales: Hegazy, Mohamed A. A., Cho, Myung Hye, Cho, Min Hyoung, Lee, Soo Yeol
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2023
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9919069/
https://www.ncbi.nlm.nih.gov/pubmed/36772330
http://dx.doi.org/10.3390/s23031288
_version_ 1784886732785713152
author Hegazy, Mohamed A. A.
Cho, Myung Hye
Cho, Min Hyoung
Lee, Soo Yeol
author_facet Hegazy, Mohamed A. A.
Cho, Myung Hye
Cho, Min Hyoung
Lee, Soo Yeol
author_sort Hegazy, Mohamed A. A.
collection PubMed
description Metal artifacts in dental computed tomography (CT) images, caused by highly X-ray absorbing objects, such as dental implants or crowns, often more severely compromise image readability than in medical CT images. Since lower tube voltages are used for dental CTs in spite of the more frequent presence of metallic objects in the patient, metal artifacts appear more severely in dental CT images, and the artifacts often persist even after metal artifact correction. The direct sinogram correction (DSC) method, which directly corrects the sinogram using the mapping function derived by minimizing the sinogram inconsistency, works well in the case of mild metal artifacts, but it often fails to correct severe metal artifacts. We propose a modified DSC method to reduce severe metal artifacts, and we have tested it on human dental images. We first segment the metallic objects in the CT image, and then we forward-project the segmented metal mask to identify the metal traces in the projection data with computing the metal path length for the rays penetrating the metal mask. In the sinogram correction with the DSC mapping function, we apply the weighting proportional to the metal path length. We have applied the proposed method to the phantom and patient images taken at the X-ray tube voltage of 90 kVp. We observed that the proposed method outperforms the original DSC method when metal artifacts were severe. However, we need further extensive studies to verify the proposed method for various CT scan conditions with many more patient images.
format Online
Article
Text
id pubmed-9919069
institution National Center for Biotechnology Information
language English
publishDate 2023
publisher MDPI
record_format MEDLINE/PubMed
spelling pubmed-99190692023-02-12 Metal Artifact Reduction in Dental CBCT Images Using Direct Sinogram Correction Combined with Metal Path-Length Weighting Hegazy, Mohamed A. A. Cho, Myung Hye Cho, Min Hyoung Lee, Soo Yeol Sensors (Basel) Article Metal artifacts in dental computed tomography (CT) images, caused by highly X-ray absorbing objects, such as dental implants or crowns, often more severely compromise image readability than in medical CT images. Since lower tube voltages are used for dental CTs in spite of the more frequent presence of metallic objects in the patient, metal artifacts appear more severely in dental CT images, and the artifacts often persist even after metal artifact correction. The direct sinogram correction (DSC) method, which directly corrects the sinogram using the mapping function derived by minimizing the sinogram inconsistency, works well in the case of mild metal artifacts, but it often fails to correct severe metal artifacts. We propose a modified DSC method to reduce severe metal artifacts, and we have tested it on human dental images. We first segment the metallic objects in the CT image, and then we forward-project the segmented metal mask to identify the metal traces in the projection data with computing the metal path length for the rays penetrating the metal mask. In the sinogram correction with the DSC mapping function, we apply the weighting proportional to the metal path length. We have applied the proposed method to the phantom and patient images taken at the X-ray tube voltage of 90 kVp. We observed that the proposed method outperforms the original DSC method when metal artifacts were severe. However, we need further extensive studies to verify the proposed method for various CT scan conditions with many more patient images. MDPI 2023-01-23 /pmc/articles/PMC9919069/ /pubmed/36772330 http://dx.doi.org/10.3390/s23031288 Text en © 2023 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Hegazy, Mohamed A. A.
Cho, Myung Hye
Cho, Min Hyoung
Lee, Soo Yeol
Metal Artifact Reduction in Dental CBCT Images Using Direct Sinogram Correction Combined with Metal Path-Length Weighting
title Metal Artifact Reduction in Dental CBCT Images Using Direct Sinogram Correction Combined with Metal Path-Length Weighting
title_full Metal Artifact Reduction in Dental CBCT Images Using Direct Sinogram Correction Combined with Metal Path-Length Weighting
title_fullStr Metal Artifact Reduction in Dental CBCT Images Using Direct Sinogram Correction Combined with Metal Path-Length Weighting
title_full_unstemmed Metal Artifact Reduction in Dental CBCT Images Using Direct Sinogram Correction Combined with Metal Path-Length Weighting
title_short Metal Artifact Reduction in Dental CBCT Images Using Direct Sinogram Correction Combined with Metal Path-Length Weighting
title_sort metal artifact reduction in dental cbct images using direct sinogram correction combined with metal path-length weighting
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9919069/
https://www.ncbi.nlm.nih.gov/pubmed/36772330
http://dx.doi.org/10.3390/s23031288
work_keys_str_mv AT hegazymohamedaa metalartifactreductionindentalcbctimagesusingdirectsinogramcorrectioncombinedwithmetalpathlengthweighting
AT chomyunghye metalartifactreductionindentalcbctimagesusingdirectsinogramcorrectioncombinedwithmetalpathlengthweighting
AT chominhyoung metalartifactreductionindentalcbctimagesusingdirectsinogramcorrectioncombinedwithmetalpathlengthweighting
AT leesooyeol metalartifactreductionindentalcbctimagesusingdirectsinogramcorrectioncombinedwithmetalpathlengthweighting