Quadratic Regularization Design for 2-D CT
Shi, Hugo R.; Fessler, Jeffrey A.
2008-10-31
Citation
Shi, H.R. ; Fessler, J.A. (2009). "Quadratic Regularization Design for 2-D CT." IEEE Transactions on Medical Imaging 28(5): 645-656. <http://hdl.handle.net/2027.42/85858>
Abstract
Statistical methods for tomographic image reconstruction have improved noise and spatial resolution properties that may improve image quality in X-ray computed tomography (CT). Penalized weighted least squares (PWLS) methods using conventional quadratic regularization lead to nonuniform and anisotropic spatial resolution due to interactions between the weighting, which is necessary for good noise properties, and the regularizer. Previously, we addressed this problem for parallel-beam emission tomography using matrix algebra methods to design data-dependent, shift-variant regularizers that improve resolution uniformity. This paper develops a fast angular integral mostly analytical (AIMA) regularization design method for 2-D fan-beam X-ray CT imaging, for which parallel-beam tomography is a special case. Simulation results demonstrate that the new method for regularization design requires very modest computation and leads to nearly uniform and isotropic spatial resolution in transmission tomography when using quadratic regularization.Publisher
IEEE
ISSN
0278-0062
Other DOIs
PMID
19272993
Types
article
Metadata
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