Share Email Print
cover

Proceedings Paper

An optimized acquisition approach exploiting geometrical calibration in x-ray cone-beam computed tomography
Author(s): Kai Xiao; Yu Han; Xiaoqi Xi; Haibing Bu; Lei Li; Bin Yan; Yanmin Sun; Jingyu Wang; Jianbang Liu
Format Member Price Non-Member Price
PDF $14.40 $18.00
cover GOOD NEWS! Your organization subscribes to the SPIE Digital Library. You may be able to download this paper for free. Check Access

Paper Abstract

X-ray cone-beam computed tomography, featuring high precision and fast-imaging speed, has been widely used in industrial non-destructive testing applications for the three dimensional visualization of internal structures. Due to mechanical imperfections, geometric calibrations are imperative to high quality image reconstruction. Currently, the twoball phantom-based calibration procedures exploiting the projection trajectories of the phantoms are the most commonly used approach for the estimation of the geometrical parameters and the calibration of CT system. However, an additional scan needs to be performed, even after each object acquisition when lack of system reproducibility, leading to multiplied calibration times. The emphasis of this paper is to optimize the process of acquisition in cone-beam CT imaging with minimal time, based on the understanding of the determination of the ball position in typical phantom-based geometric calibration algorithms. An applicable condition of the calibration algorithm for simultaneously scanning objects and calibration phantoms is proposed and demonstrated, which is that the minimum projection value of the scanned object needs to be at least 100 counts higher than those of the calibration phantom, with consideration of the system noise. The CT experiments are based on a laboratory industrial cone-beam CT system with a micro-focus x-ray tube (Thales Hawkeye 130) and a flat panel detector (Thales Pixium RF4343). Objects imaged are chosen with a wide projection value range, from low-Z watermelon seeds and high-Z materials, including a standard Micro CT Bar Pattern Phantom (QRM) for image quality assessment. In these experiments, objects, as well as two-ball phantoms, both placed in the field of view without overlapping in the vertical direction, are projected over 360 degrees, instead of scanning the calibration phantoms separately. Hence, the true geometrical relationship is resolved utilizing the two-ball algorithm. Both simulation and experimental results confirm that the calculated geometrical parameters will not be affected by the objects as long as their projection value difference meeting the requirements above. And the reconstruction image quality is almost the same with those by an independent calibration. Compared to the traditional application of the phantombased geometrical calibration method, the novel approach presented in this paper has obvious advantages from an imaging perspective, saving acquisition time and eliminating the undesired influence from the operation staff for the same cost.

Paper Details

Date Published: 24 October 2017
PDF: 5 pages
Proc. SPIE 10462, AOPC 2017: Optical Sensing and Imaging Technology and Applications, 104624Q (24 October 2017); doi: 10.1117/12.2285578
Show Author Affiliations
Kai Xiao, National Digital Switching System Engineering and Technological Research Ctr. (China)
Yu Han, National Digital Switching System Engineering and Technological Research Ctr. (China)
Xiaoqi Xi, National Digital Switching System Engineering and Technological Research Ctr. (China)
Haibing Bu, National Digital Switching System Engineering and Technological Research Ctr. (China)
Lei Li, National Digital Switching System Engineering and Technological Research Ctr. (China)
Bin Yan, National Digital Switching System Engineering and Technological Research Ctr. (China)
Yanmin Sun, National Digital Switching System Engineering and Technological Research Ctr. (China)
Jingyu Wang, National Digital Switching System Engineering and Technological Research Ctr. (China)
Jianbang Liu, National Digital Switching System Engineering and Technological Research Ctr. (China)


Published in SPIE Proceedings Vol. 10462:
AOPC 2017: Optical Sensing and Imaging Technology and Applications
Yadong Jiang; Haimei Gong; Weibiao Chen; Jin Li, Editor(s)

© SPIE. Terms of Use
Back to Top