title: Optimized Bayes variational regularization prior for 3D PET images.
abstract: A new prior for variational Maximum a Posteriori regularization is proposed to be used in a 3D One-Step-Late (OSL) reconstruction algorithm accounting also for the Point Spread Function (PSF) of the PET system. The new regularization prior strongly smoothes background regions, while preserving transitions. A detectability index is proposed to optimize the prior. The new algorithm has been compared with different reconstruction algorithms such as 3D-OSEM+PSF, 3D-OSEM+PSF+post-filtering and 3D-OSL with a Gauss-Total Variation (GTV) prior. The proposed regularization allows controlling noise, while maintaining good signal recovery; compared to the other algorithms it demonstrates a very good compromise between an improved quantitation and good image quality.
authors: IBFM-CNR, Institute for Molecular Bioimaging and Physiology, 20090 Segrate, Italy; Unit of Nuclear Medicine, IRCCS San Raffaele Scientific Institute, 20132 Milano, Italy; Department of Physics, University of Milano-Bicocca, 20126 Milano, Italy. Electronic address: rapisarda.eugenio@hsr.it.
authors: Eugenio
authors: E
authors: Rapisarda
authors: Unit of Nuclear Medicine, IRCCS San Raffaele Scientific Institute, 20132 Milano, Italy; Department of Physics, University of Milano-Bicocca, 20126 Milano, Italy. Electronic address: presotto.luca@hsr.it.
authors: Luca
authors: L
authors: Presotto
authors: Unit of Nuclear Medicine, IRCCS San Raffaele Scientific Institute, 20132 Milano, Italy; Department of Health Sciences - Tecnomed Foundation, University of Milano-Bicocca, 20900 Monza, Italy. Electronic address: elisabetta.debernardi@unimib.it.
authors: Elisabetta
authors: E
authors: De Bernardi
authors: IBFM-CNR, Institute for Molecular Bioimaging and Physiology, 20090 Segrate, Italy; Unit of Nuclear Medicine, IRCCS San Raffaele Scientific Institute, 20132 Milano, Italy; Department of Health Sciences - Tecnomed Foundation, University of Milano-Bicocca, 20900 Monza, Italy. Electronic address: gilardi.mariacarla@hsr.it.
authors: Maria Carla
authors: MC
authors: Gilardi
authors: Unit of Nuclear Medicine, IRCCS San Raffaele Scientific Institute, 20132 Milano, Italy. Electronic address: bettinardi.valentino@hsr.it.
authors: Valentino
authors: V
authors: Bettinardi
mesh_terms: D000465:Algorithms; D001499:Bayes Theorem; D021621:Imaging, Three-Dimensional; D049268:Positron-Emission Tomography / Q000379:methods*
keywords: 3-D image reconstruction; Image regularization; Point spread function; Positron emission tomography (PET)