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Proceedings Paper

Impact of CT detector pixel-to-pixel crosstalk on image quality
Author(s): Klaus J. Engel; Lothar Spies; Gereon Vogtmeier; Randy Luhta
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Paper Abstract

In Computed Tomography (CT), the image quality sensitively depends on the accuracy of the X-ray projection signal, which is acquired by a two-dimensional array of pixel cells in the detector. If the signal of X-ray photons is spread out to neighboring pixels (crosstalk), a decrease of spatial resolution may result. Moreover, streak and ring artifacts may emerge. Deploying system simulations for state-of-the-art CT detector configurations, we characterize origin and appearance of these artifacts in the reconstructed CT images for different scenarios. A uniform pixel-to-pixel crosstalk results in a loss of spatial resolution only. The Modulation Transfer Function (MTF) is attenuated, without affecting the limiting resolution, which is defined as the first zero of the MTF. Additional streak and ring artifacts appear, if the pixel-to-pixel crosstalk is non-uniform. Parallel to the system simulations we developed an analytical model. The model explains resolution loss and artifact level using the first and second derivative of the X-ray profile acquired by the detector. Simulations and analytical model are in agreement to each other. We discuss the perceptibility of ring and streak artifacts within noisy images if no crosstalk correction is applied.

Paper Details

Date Published: 2 March 2006
PDF: 12 pages
Proc. SPIE 6142, Medical Imaging 2006: Physics of Medical Imaging, 61422F (2 March 2006); doi: 10.1117/12.654499
Show Author Affiliations
Klaus J. Engel, Philips Research Europe (Germany)
Lothar Spies, Philips Research Europe (Germany)
Gereon Vogtmeier, Philips Research Europe (Germany)
Randy Luhta, Philips Medical Systems (United States)

Published in SPIE Proceedings Vol. 6142:
Medical Imaging 2006: Physics of Medical Imaging
Michael J. Flynn; Jiang Hsieh, Editor(s)

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