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Multiclass Dictionary-Based Statistical Iterative Reconstruction for Low-Dose CT

Hiryu KAMOSHITA, Daichi KITAHARA, Ken'ichi FUJIMOTO, Laurent CONDAT, Akira HIRABAYASHI

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Summary :

This paper proposes a high-quality computed tomography (CT) image reconstruction method from low-dose X-ray projection data. A state-of-the-art method, proposed by Xu et al., exploits dictionary learning for image patches. This method generates an overcomplete dictionary from patches of standard-dose CT images and reconstructs low-dose CT images by minimizing the sum of a data fidelity and a regularization term based on sparse representations with the dictionary. However, this method does not take characteristics of each patch, such as textures or edges, into account. In this paper, we propose to classify all patches into several classes and utilize an individual dictionary with an individual regularization parameter for each class. Furthermore, for fast computation, we introduce the orthogonality to column vectors of each dictionary. Since similar patches are collected in the same cluster, accuracy degradation by the orthogonality hardly occurs. Our simulations show that the proposed method outperforms the state-of-the-art in terms of both accuracy and speed.

Publication
IEICE TRANSACTIONS on Fundamentals Vol.E104-A No.4 pp.702-713
Publication Date
2021/04/01
Publicized
2020/10/06
Online ISSN
1745-1337
DOI
10.1587/transfun.2020EAP1020
Type of Manuscript
PAPER
Category
Numerical Analysis and Optimization

Authors

Hiryu KAMOSHITA
  Ritsumeikan University
Daichi KITAHARA
  Ritsumeikan University
Ken'ichi FUJIMOTO
  Kagawa University
Laurent CONDAT
  King Abdullah University of Science and Technology
Akira HIRABAYASHI
  Ritsumeikan University

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