Statistical image reconstruction with beam-hardening compensation for X-ray CT by a calibration step (2DIterBH).
Med Phys
; 51(8): 5204-5213, 2024 Aug.
Article
em En
| MEDLINE
| ID: mdl-38873959
ABSTRACT
BACKGROUND:
The beam-hardening effect due to the polychromatic nature of the X-ray spectra results in two main artifacts in CT images cupping in homogeneous areas and dark bands between dense parts in heterogeneous samples. Post-processing methods have been proposed in the literature to compensate for these artifacts, but these methods may introduce additional noise in low-dose acquisitions. Iterative methods are an alternative to compensate noise and beam-hardening artifacts simultaneously. However, they usually rely on the knowledge of the spectrum or the selection of empirical parameters.PURPOSE:
We propose an iterative reconstruction method with beam hardening compensation for small animal scanners that is robust against low-dose acquisitions and that does not require knowledge of the spectrum, overcoming the limitations of current beam-hardening correction algorithms.METHODS:
The proposed method includes an empirical characterization of the beam-hardening function based on a simple phantom in a polychromatic statistical reconstruction method. Evaluation was carried out on simulated data with different noise levels and step angles and on limited-view rodent data acquired with the ARGUS/CT system.RESULTS:
Results in small animal studies showed a proper correction of the beam-hardening artifacts in the whole sample, independently of the quantity of bone present on each slice. The proposed approach also reduced noise in the low-dose acquisitions and reduced streaks in the limited-view acquisitions.CONCLUSIONS:
Using an empirical model for the beam-hardening effect, obtained through calibration, in an iterative reconstruction method enables a robust correction of beam-hardening artifacts in low-dose small animal studies independently of the bone distribution.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Processamento de Imagem Assistida por Computador
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Tomografia Computadorizada por Raios X
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Artefatos
/
Imagens de Fantasmas
Limite:
Animals
Idioma:
En
Revista:
Med Phys
/
Med. phys
/
Medical physics
Ano de publicação:
2024
Tipo de documento:
Article
País de afiliação:
Espanha
País de publicação:
Estados Unidos