PT  - JOURNAL ARTICLE
AU  - Kye Young Jeong
AU  - Woo Hyun Nam
AU  - Ji Hye Kim
AU  - Il Jun Ahn
AU  - Jong Beom Ra
TI  - Sinogram super-resolution based on system response function of PET scanner
DP  - 2011 May 01
TA  - Journal of Nuclear Medicine
PG  - 1999--1999
VI  - 52
IP  - supplement 1
4099  - http://jnm.snmjournals.org/content/52/supplement_1/1999.short
4100  - http://jnm.snmjournals.org/content/52/supplement_1/1999.full
SO  - J Nucl Med2011 May 01; 52
AB  - 1999 Objectives Positron emission tomography (PET) images suffer from low spatial resolution. A couple of decades ago, Wernick et al. attempted super-resolution (SR) for wobbled sinograms. However, this primitive work was tried only through a simple mathematical simulation without considering the practical system characteristics. In this paper, we introduce an efficient SR scheme on the basis of the estimation of a space variant blur matrix. Methods In order to obtain a high-resolution (HR) sinogram, the relationship between the HR sinogram and low-resolution (LR) sinograms should be estimated. We determine this relationship by obtaining space variant point source responses through a Monte Carlo (MC) simulation using a GATE simulation package. To examine the corresponding SR performance, we also obtain four wobbled LR sinograms through a MC simulation based on the scanner model of a microPET R4 system (Concorde Microsystems, Inc., Knoxville, Tennessee). Results We first obtain four LR sinograms of a resolution phantom. Using the four LR sinograms and the determined space variant point source responses, we then perform SR to obtain an HR sinogram. For comparison, we also obtain the sinogram by simply interpolating four LR sinograms and the sinogram by applying SR with a space invariant point source response. Using those sinograms, we reconstruct images based on an ordered-subsets expectation-maximization (OSEM) algorithm. From the sinograms and reconstructed images, it is clearly seen that the proposed SR algorithm improves the resolution of reconstructed images as well as sinogram and restores the correct position information. Conclusions We introduce an effective super-resolution scheme based on multiple LR sinograms. Through the experiments, we demonstrated that the proposed super-resolution scheme can noticeably improve the spatial image resolution and alleviate the problems of resolution degradation and position shifts in the off-center region. Research Support The research was supported by the Converging Research Center Program through the Ministry of Education, Science and Technology (2010K001093)