Publication
Title
Iterative correction of beam hardening artifacts in CT
Author
Abstract
Purpose: To reduce beam hardening artifacts in CT in case of an unknown x-ray spectrum and unknown material properties. Methods: The authors assume that the object can be segmented into a few materials with different attenuation coefficients, and parameterize the spectrum using a small number of energy bins. The corresponding unknown spectrum parameters and material attenuation values are estimated by minimizing the difference between the measured sinogram data and a simulated polychromatic sinogram. Three iterative algorithms are derived from this approach: two reconstruction algorithms IGR and IFR, and one sinogram precorrection method ISP. Results: The methods are applied on real x-ray data of a high and a low-contrast phantom. All three methods successfully reduce the cupping artifacts caused by the beam polychromaticity in such a way that the reconstruction of each homogeneous region is to good accuracy homogeneous, even in case the segmentation of the preliminary reconstruction image is poor. In addition, the results show that the three methods tolerate relatively large variations in uniformity within the segments. Conclusions: We show that even without prior knowledge about materials or spectrum, effective beam hardening correction can be obtained.
Language
English
Source (journal)
Medical physics. - New York, N.Y.
Publication
New York, N.Y. : 2011
ISSN
0094-2405 [print]
2473-4209 [online]
Volume/pages
38:S:1(2011), p. S36,1-S36,14
Article Reference
S36
ISI
000293177300005
Medium
E-only publicatie
Full text (Publisher's DOI)
UAntwerpen
Faculty/Department
Research group
Publication type
Subject
Affiliation
Publications with a UAntwerp address
External links
Web of Science
Record
Identification
Creation 02.08.2011
Last edited 05.11.2017
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