Share Email Print

Proceedings Paper

Improved scatter correction for x-ray conebeam CT using primary modulation
Author(s): Lei Zhu; Josh StarLack; N. Robert Bennett; Tianfang Li; Lei Xing; Rebecca Fahrig
Format Member Price Non-Member Price
PDF $17.00 $21.00

Paper Abstract

Recently, we proposed a scatter correction method for x-ray imaging using primary modulation. A primary modulator with spatially variant attenuating materials is inserted between the x-ray source and the object to make the scatter and part of the primary distributions strongly separate in the Fourier domain. Linear filtering and demodulation techniques suffice to extract and correct the scatter for this modified system. The method has been verified by computer simulations and preliminary experimental results on a simple object. In this work, we improve performance by using a new primary modulator with a higher modulation frequency and by refining the algorithm. The improved method is evaluated experimentally using a pelvis phantom. The imaging parameters are chosen to match the Varian Acuity CT simulator, where scatter correction has been shown to be challenging due to complicated artifact patterns. The results using our approach are compared with those without scatter correction, and with scatter estimated and corrected using a slit measurement as a pre-scan. The comparison shows that the primary modulation method greatly reduces the scatter artifacts and improves image contrast. Using only one single scan, this method achieves CT HU accuracy comparable to that obtained using a slit measurement as a pre-scan.

Paper Details

Date Published: 21 March 2007
PDF: 8 pages
Proc. SPIE 6510, Medical Imaging 2007: Physics of Medical Imaging, 65101U (21 March 2007); doi: 10.1117/12.713678
Show Author Affiliations
Lei Zhu, Stanford Univ. (United States)
Josh StarLack, Varian Medical Systems (United States)
N. Robert Bennett, Stanford Univ. (United States)
Tianfang Li, Stanford Univ. (United States)
Lei Xing, Stanford Univ. (United States)
Rebecca Fahrig, Stanford Univ. (United States)

Published in SPIE Proceedings Vol. 6510:
Medical Imaging 2007: Physics of Medical Imaging
Jiang Hsieh; Michael J. Flynn, Editor(s)

© SPIE. Terms of Use
Back to Top
Sign in to read the full article
Create a free SPIE account to get access to
premium articles and original research
Forgot your username?