Paper
5 June 2003 Local convolution-deconvolution for resolution restoration and recovery in PET: a feasibility study
Sharok Kimiaei, Refaat Al-Mazrou, Omer Demirkaya
Author Affiliations +
Abstract
Positron Emission Tomography (PET) is one of the most popular methods for accurate localization and quantification of in vivo concentration of radioactivity. However, in most circular PET scanners, the inherent detector geometry results in a distance dependent and variant point spread function (PSF) in the image plane. Off-centered point sources are imaged with impaired spatial resolution in the radial direction resultng in elliptically shaped points. While some attempts have been made to correct for this unwanted image deterioration through incorporation of the variant detector blurring in the iterative reconstruction procedures, in most cases this effect has been disregarded and the images are uncorrected. In this paper we present and evaluate, by means of computer simulation, a novel approach for correction of the distance dependent and spatially variant point spread function in a two-step procedure. The projections are first homogenized through a non-linear convolution schema prior to reconstruction. In the second step, in order to compensate for the convolution performed in the first step, the spatially shift invariant images thus obtained are deconvolved using a conventional deconvolution method. The preliminary results show that the homogenization can completely remove the shift variant non-isotropic blurring in the image plane. Resolution of the images deconvolved with Lucy-Richardson deconvolution method was improved from 9 mm to 3 mm with maintained shift-invariance.
© (2003) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Sharok Kimiaei, Refaat Al-Mazrou, and Omer Demirkaya "Local convolution-deconvolution for resolution restoration and recovery in PET: a feasibility study", Proc. SPIE 5030, Medical Imaging 2003: Physics of Medical Imaging, (5 June 2003); https://doi.org/10.1117/12.480152
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KEYWORDS
Sensors

Positron emission tomography

Homogenization

Convolution

Point spread functions

Deconvolution

Image resolution

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