Analytical Geometric Model for Photon Coincidence Detection in 3D PET

Prieta, R. de la; Hernandez, Jessica; Schiavi, Emanuele; Malpica, Norberto

doi:10.1109/nssmic.2006.354357

Cited by 3 publications

(2 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…2D approximations have been proposed (Selivanov et al 2000, Strul et al 2003, Yamaya et al 2005. In 3D methods, the complexity of exact calculations (de la Prieta et al 2006) has suggested the use of multiple ray-tracing methods to approximate volumes of intersection and physical properties of crystals (Moehrs et al 2008, Yamaya et al 2008.…”

Section: Introductionmentioning

confidence: 99%

Efficient methodologies for system matrix modelling in iterative image reconstruction for rotating high-resolution PET

Ortuño¹,

Kontaxakis²,

Rubio³

et al. 2010

Phys. Med. Biol.

View full text Add to dashboard Cite

A fully 3D iterative image reconstruction algorithm has been developed for high-resolution PET cameras composed of pixelated scintillator crystal arrays and rotating planar detectors, based on the ordered subsets approach. The associated system matrix is precalculated with Monte Carlo methods that incorporate physical effects not included in analytical models, such as positron range effects and interaction of the incident gammas with the scintillator material. Custom Monte Carlo methodologies have been developed and optimized for modelling of system matrices for fast iterative image reconstruction adapted to specific scanner geometries, without redundant calculations. According to the methodology proposed here, only one-eighth of the voxels within two central transaxial slices need to be modelled in detail. The rest of the system matrix elements can be obtained with the aid of axial symmetries and redundancies, as well as in-plane symmetries within transaxial slices. Sparse matrix techniques for the non-zero system matrix elements are employed, allowing for fast execution of the image reconstruction process. This 3D image reconstruction scheme has been compared in terms of image quality to a 2D fast implementation of the OSEM algorithm combined with Fourier rebinning approaches. This work confirms the superiority of fully 3D OSEM in terms of spatial resolution, contrast recovery and noise reduction as compared to conventional 2D approaches based on rebinning schemes. At the same time it demonstrates that fully 3D methodologies can be efficiently applied to the image reconstruction problem for high-resolution rotational PET cameras by applying accurate pre-calculated system models and taking advantage of the system's symmetries.

show abstract

Section: Introductionmentioning

confidence: 99%

Efficient methodologies for system matrix modelling in iterative image reconstruction for rotating high-resolution PET

Ortuño¹,

Kontaxakis²,

Rubio³

et al. 2010

Phys. Med. Biol.

View full text Add to dashboard Cite

show abstract

“…This assumption, being valid for CT, is not completely realistic for PET and SPECT acquisitions [6][7][8][9]. In SPECT some efforts have been devoted to take into account this spatially variant detector response [9], but the impact of it on TDCC has not been fully addressed.…”

Section: Introductionmentioning

confidence: 99%

Revised consistency conditions for PET data

Herraiz

España

Vicente

et al. 2007

2007 IEEE Nuclear Science Symposium Conference Record

View full text Add to dashboard Cite

Tomographic Data Consistency Conditions (TDCC) are frequently employed to improve the quality of PET data. However, most of these consistency conditions were derived from X-ray computerized tomography (CT) and their validity for other imaging modalities has not been well established. For instance, it is well known from (X-ray) CT data that the sum of the projection data from one view of the parallel-beam projections is a constant independent of the view-angle. This consistency condition is based on well-known mathematical properties of the Radon transform and yields good results when employed in noise removal or sinogram restoration. But this consistency condition assumes that emission and detection of radiation occur within a thin (ideally with zero width) line-ofresponse (LOR), with a flat probability distribution of the detection (in PET) or absorption (X-ray) along such LOR. This assumption, being valid for CT, is not realistic for PET acquisitions. Thus, TDCC for PET should be revised in order to check their validity with more realistic detection models.In this work we review the main differences between PET and CT data and study whether these consistency conditions should be modified in order to take into account the dependence of the probabilities on the distance to the center of the line-of-response. Results from simulations are also presented to illustrate the importance of these effects. They indicate that some consistency conditions can be violated at the 10% level.

show abstract

Free Software for PET Imaging

Prieta¹

2012

Positron Emission Tomography - Current Clinical and Research Aspects

View full text Add to dashboard Cite

Analytical Geometric Model for Photon Coincidence Detection in 3D PET

Cited by 3 publications

References 15 publications

Efficient methodologies for system matrix modelling in iterative image reconstruction for rotating high-resolution PET

Efficient methodologies for system matrix modelling in iterative image reconstruction for rotating high-resolution PET

Revised consistency conditions for PET data

Free Software for PET Imaging

Contact Info

Product

Resources

About