Title
Benefits of Using a Spatially-variant Penalty Strength with Anatomical Priors in PET Reconstruction.
Abstract
In this study, we explore the use of a spatially-variant penalty strength in penalized image reconstruction using anatomical priors to reduce the dependence of lesion contrast on surrounding activity and lesion location. This work builds on a previous method to make the local perturbation response (LPR) approximately spatially invariant. While the dependence of lesion contrast on the local properties introduced by the anatomical penalty is intentional, the method aims to reduce the influence from surroundings lying along the lines of response (LORs) but not in the penalty neighborhood structure. The method is evaluated using simulated data, assuming that the anatomical information is absent or well-aligned with the corresponding activity images. Since the parallel level sets (PLS) penalty is convex and has shown promising results in the literature, it is chosen as the representative anatomical penalty and incorporated into the previously proposed preconditioned algorithm (L-BFGS-B-PC) for achieving good image quality and fast convergence rate. A 2D disc phantom with a feature at the center and a 3D XCAT thorax phantom with lesions inserted in different slices are used to study how surrounding activity and lesion location affect the visual appearance and quantitative consistency. A bias and noise analysis is also performed with the 2D disc phantom. The consistency of the algorithm convergence rate with respect to different data noise and background levels is also investigated using the XCAT phantom. Finally, an example of reconstruction for a patient dataset with inserted pseudo lesions is used as a demonstration in a clinical context. We show that applying the spatially-variant penalization with PLS can reduce the dependence of the lesion contrast on the surrounding activity and lesion location. It does not affect the bias and noise trade-off curves for matched local resolution. Moreover, when using the proposed penalization, significant improvement in algorithm convergence rate and convergence consistency is observed.
Year
DOI
Venue
2020
10.1109/TMI.2019.2913889
IEEE transactions on medical imaging
Keywords
Field
DocType
Image reconstruction,Lesions,Perturbation methods,Convergence,Phantoms,Two dimensional displays,Three-dimensional displays
Iterative reconstruction,Convergence (routing),Computer vision,Pattern recognition,Imaging phantom,Level set,Image quality,Invariant (mathematics),Artificial intelligence,Rate of convergence,Prior probability,Mathematics
Journal
Volume
Issue
ISSN
39
1
0278-0062
Citations 
PageRank 
References 
0
0.34
0
Authors
9
Name
Order
Citations
PageRank
Yu-Jung Tsai100.68
Schramm, G.211.76
Sangtae Ahn3639.69
Alexandre Bousse482.96
Simon R Arridge553274.17
J Nuyts625130.82
Brian F. Hutton79814.33
Charles W. Stearns820.70
Kris Thielemans933.43