Counter examples for unmatched projector/backprojector in an iterative algorithm.

Chinese Journal of Academic Radiology
Gengsheng L Zeng

Abstract

It is rather controversial whether it is justified to use an unmatched projector/backprojector pair in an iterative image reconstruction algorithm. One common concern of using an unmatched projector/backprojector pair is that the optimal solution cannot be reached. This concern is misleading and must be clarified. We define a figure-of-merit in the image domain as the distance between the reconstructed image and the true image, as the normalized mean-squared-error (NMSE). The NMSE is used to determine whether an unmatched matched projector/backprojector pair can provide a better image than a matched projector/backprojector pair. Hot and cold lesion's contrast-to-noise ratio is also used as an alternative secondary figure-of-merit for algorithm comparison. Computer-generated counterexamples are used to test the performance for matched and unmatched projection/backprojection pairs for different reconstruction algorithms. The projectors are ray-driven, and the backprojectors are ray-driven and pixel-driven. For the attenuation-free data examples, the unmatched pixel-driven backprojector outperforms the matched ray-driven backprojector. For the attenuated data example, the matched ray-driven backprojector performs better. The ray-d...Continue Reading

References

Oct 6, 2000·IEEE Transactions on Medical Imaging·G L Zeng, G T Gullberg
Jul 14, 2004·Physics in Medicine and Biology·Bruno De Man, Samit Basu
Jan 1, 1990·IEEE Transactions on Medical Imaging·P J Green
Jan 1, 1982·IEEE Transactions on Medical Imaging·L A Shepp, Y Vardi
May 7, 2008·Nuclear Medicine Communications·Arman RahmimVesna Sossi
Sep 22, 2011·Optics Express·Sébastien HarasseAtsushi Momose
Jun 6, 2015·Microscopy and Microanalysis : the Official Journal of Microscopy Society of America, Microbeam Analysis Society, Microscopical Society of Canada·Tim DahmenPhilipp Slusallek
Jun 1, 2015·IEEE Transactions on Nuclear Science·Gengsheng L Zeng

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Citations

Aug 24, 2021·Medical Physics·Marion SavanierJean-Christophe Pesquet

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