ID | 117151 |
タイトル別表記 | 拡張した冪指数型ダイバージェンス測度を用いて動的に選択したスパースな投影ビューからのブロック反復再構成
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著者 |
石川, 和希
徳島大学大学院保健科学研究科(保健学専攻)
山口, 雄作
Shikoku Medical Center for Children and Adults, National Hospital Organization
アボウ アルオラ, オマル
Tanta University
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キーワード | power-divergence measure
computed tomography
iterative reconstruction
ordered-subsets algorithm
block-iterative reconstruction
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資料タイプ |
学位論文
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抄録 | Iterative reconstruction of density pixel images from measured projections in computed tomography has attracted considerable attention. The ordered-subsets algorithm is an acceleration scheme that uses subsets of projections in a previously decided order. Several methods have been proposed to improve the convergence rate by permuting the order of the projections. However, they do not incorporate object information, such as shape, into the selection process. We propose a block-iterative reconstruction from sparse projection views with the dynamic selection of subsets based on an estimating function constructed by an extended power-divergence measure for decreasing the objective function as much as possible. We give a unified proposition for the inequality related to the difference between objective functions caused by one iteration as the theoretical basis of the proposed optimization strategy. Through the theory and numerical experiments, we show that nonuniform and sparse use of projection views leads to a reconstruction of higher-quality images and that an ordered subset is not the most effective for block-iterative reconstruction. The two-parameter class of extended power-divergence measures is the key to estimating an effective decrease in the objective function and plays a significant role in constructing a robust algorithm against noise.
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掲載誌名 |
Entropy
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ISSN | 10994300
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出版者 | MDPI
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巻 | 24
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号 | 5
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開始ページ | 740
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発行日 | 2022-05-23
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備考 | 内容要旨・審査要旨・論文本文の公開
本論文は,著者Kazuki Ishikawaの学位論文として提出され,学位審査・授与の対象となっている。 |
権利情報 | 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/).
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言語 |
eng
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著者版フラグ |
博士論文全文を含む
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文科省報告番号 | 甲第3772号
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学位記番号 | 甲保第62号
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学位授与年月日 | 2024-02-21
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学位名 |
博士(保健学)
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学位授与機関 |
徳島大学
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部局 |
医学系
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