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Title: Beam Hardening Corrections in Quantitative Computed Tomography

Abstract

Volumetric computed tomography (VCT) is the emerging 3D NDE inspection technique that gives highest throughput and better image quality. Industrial components in general demands higher x-ray energy for inspection for which polychromatic x-ray sources are used in common. Polychromatic nature of the x-rays gives rise to non-linear effects in the VCT projection data measurements called to be the beam hardening (BH) effects. BH produces prominent artifacts in the reconstructed images thereby deteriorating the image quality. Quantitative analysis such as density quantification, dimensional analysis etc., becomes difficult with the presence of these artifacts. This paper describes the BH correction using preprocessing technique for the homogeneous materials. Selection of effective energy at which the monoenergetic linear attenuation coefficient of a particular material equals to that of the polyenergetic beam is critical for BH correction. Various methods to determine the effective energy and their consequence in the quantitative measurements have been investigated in the present study. In this paper, BH corrections for heterogeneous materials have also been explored.

Authors:
; ; ;  [1]
  1. John F. Welch Technology Centre, GE Global Research Centre, Bangalore, (India)
Publication Date:
OSTI Identifier:
21054974
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 894; Journal Issue: 1; Conference: Conference on review of progress in quantitative nondestructive evaluation, Portland, OR (United States), 30 Jul - 4 Aug 2006; Other Information: DOI: 10.1063/1.2718019; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ATTENUATION; COMPUTERIZED TOMOGRAPHY; CORRECTIONS; DENSITY; HARDENING; IMAGES; NONDESTRUCTIVE TESTING; NONLINEAR PROBLEMS; X RADIATION; X-RAY SOURCES

Citation Formats

Vedula, Venumadhav, Venugopal, Manoharan, Raghu, C., and Pandey, Pramod. Beam Hardening Corrections in Quantitative Computed Tomography. United States: N. p., 2007. Web. doi:10.1063/1.2718019.
Vedula, Venumadhav, Venugopal, Manoharan, Raghu, C., & Pandey, Pramod. Beam Hardening Corrections in Quantitative Computed Tomography. United States. doi:10.1063/1.2718019.
Vedula, Venumadhav, Venugopal, Manoharan, Raghu, C., and Pandey, Pramod. Wed . "Beam Hardening Corrections in Quantitative Computed Tomography". United States. doi:10.1063/1.2718019.
@article{osti_21054974,
title = {Beam Hardening Corrections in Quantitative Computed Tomography},
author = {Vedula, Venumadhav and Venugopal, Manoharan and Raghu, C. and Pandey, Pramod},
abstractNote = {Volumetric computed tomography (VCT) is the emerging 3D NDE inspection technique that gives highest throughput and better image quality. Industrial components in general demands higher x-ray energy for inspection for which polychromatic x-ray sources are used in common. Polychromatic nature of the x-rays gives rise to non-linear effects in the VCT projection data measurements called to be the beam hardening (BH) effects. BH produces prominent artifacts in the reconstructed images thereby deteriorating the image quality. Quantitative analysis such as density quantification, dimensional analysis etc., becomes difficult with the presence of these artifacts. This paper describes the BH correction using preprocessing technique for the homogeneous materials. Selection of effective energy at which the monoenergetic linear attenuation coefficient of a particular material equals to that of the polyenergetic beam is critical for BH correction. Various methods to determine the effective energy and their consequence in the quantitative measurements have been investigated in the present study. In this paper, BH corrections for heterogeneous materials have also been explored.},
doi = {10.1063/1.2718019},
journal = {AIP Conference Proceedings},
number = 1,
volume = 894,
place = {United States},
year = {Wed Mar 21 00:00:00 EDT 2007},
month = {Wed Mar 21 00:00:00 EDT 2007}
}
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  • Beam hardening (BH), caused by the energy dependence of x-ray attenuation in materials, reduces the reliability of images generated by computed tomographic (CT) when polychromatic x-ray sources are used. The magnitude of the BH effect was calculated, and four different approaches to BH correction for CT imaging of ceramics were investigated: the ''water bag'' approach, prehardening of the beam by use of a filter, linearization correction, and dual-energy methods. The dual-energy approach appears to be a promising means of BH correction for CT imaging of ceramics. 23 refs., 22 figs.
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