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The impact of reconstruction algorithms and time of flight information on PET/CT image quality

BACKGROUND: The aim of the study was to explore the influence of various time-of-flight (TOF) and non-TOF reconstruction algorithms on positron emission tomography/computer tomography (PET/CT) image quality. MATERIALS AND METHODS. Measurements were performed with a triple line source phantom, consis...

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Autores principales: Suljic, Alen, Tomse, Petra, Jensterle, Luka, Skrk, Damijan
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Versita, Warsaw 2015
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4577218/
https://www.ncbi.nlm.nih.gov/pubmed/26401127
http://dx.doi.org/10.1515/raon-2015-0014
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author Suljic, Alen
Tomse, Petra
Jensterle, Luka
Skrk, Damijan
author_facet Suljic, Alen
Tomse, Petra
Jensterle, Luka
Skrk, Damijan
author_sort Suljic, Alen
collection PubMed
description BACKGROUND: The aim of the study was to explore the influence of various time-of-flight (TOF) and non-TOF reconstruction algorithms on positron emission tomography/computer tomography (PET/CT) image quality. MATERIALS AND METHODS. Measurements were performed with a triple line source phantom, consisting of capillaries with internal diameter of ∼ 1 mm and standard Jaszczak phantom. Each of the data sets was reconstructed using analytical filtered back projection (FBP) algorithm, iterative ordered subsets expectation maximization (OSEM) algorithm (4 iterations, 24 subsets) and iterative True-X algorithm incorporating a specific point spread function (PSF) correction (4 iterations, 21 subsets). Baseline OSEM (2 iterations, 8 subsets) was included for comparison. Procedures were undertaken following the National Electrical Manufacturers Association (NEMA) NU-2-2001 protocol. RESULTS: Measurement of spatial resolution in full width at half maximum (FWHM) was 5.2 mm, 4.5 mm and 2.9 mm for FBP, OSEM and True-X; and 5.1 mm, 4.5 mm and 2.9 mm for FBP+TOF, OSEM+TOF and True-X+TOF respectively. Assessment of reconstructed Jaszczak images at different concentration ratios showed that incorporation of TOF information improves cold contrast, while hot contrast only slightly, however the most prominent improvement could be seen in background variability - noise reduction. CONCLUSIONS: On the basis of the results of investigation we concluded, that incorporation of TOF information in reconstruction algorithm mostly affects reduction of the background variability (levels of noise in the image), while the improvement of spatial resolution due to incorporation of TOF information is negligible. Comparison of traditional and modern reconstruction algorithms showed that analytical FBP yields comparable results in some parameter measurements, such as cold contrast and relative count error. Iterative methods show highest levels of hot contrast, when TOF and PSF corrections were applied simultaneously.
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spelling pubmed-45772182015-09-23 The impact of reconstruction algorithms and time of flight information on PET/CT image quality Suljic, Alen Tomse, Petra Jensterle, Luka Skrk, Damijan Radiol Oncol Research Article BACKGROUND: The aim of the study was to explore the influence of various time-of-flight (TOF) and non-TOF reconstruction algorithms on positron emission tomography/computer tomography (PET/CT) image quality. MATERIALS AND METHODS. Measurements were performed with a triple line source phantom, consisting of capillaries with internal diameter of ∼ 1 mm and standard Jaszczak phantom. Each of the data sets was reconstructed using analytical filtered back projection (FBP) algorithm, iterative ordered subsets expectation maximization (OSEM) algorithm (4 iterations, 24 subsets) and iterative True-X algorithm incorporating a specific point spread function (PSF) correction (4 iterations, 21 subsets). Baseline OSEM (2 iterations, 8 subsets) was included for comparison. Procedures were undertaken following the National Electrical Manufacturers Association (NEMA) NU-2-2001 protocol. RESULTS: Measurement of spatial resolution in full width at half maximum (FWHM) was 5.2 mm, 4.5 mm and 2.9 mm for FBP, OSEM and True-X; and 5.1 mm, 4.5 mm and 2.9 mm for FBP+TOF, OSEM+TOF and True-X+TOF respectively. Assessment of reconstructed Jaszczak images at different concentration ratios showed that incorporation of TOF information improves cold contrast, while hot contrast only slightly, however the most prominent improvement could be seen in background variability - noise reduction. CONCLUSIONS: On the basis of the results of investigation we concluded, that incorporation of TOF information in reconstruction algorithm mostly affects reduction of the background variability (levels of noise in the image), while the improvement of spatial resolution due to incorporation of TOF information is negligible. Comparison of traditional and modern reconstruction algorithms showed that analytical FBP yields comparable results in some parameter measurements, such as cold contrast and relative count error. Iterative methods show highest levels of hot contrast, when TOF and PSF corrections were applied simultaneously. Versita, Warsaw 2015-08-21 /pmc/articles/PMC4577218/ /pubmed/26401127 http://dx.doi.org/10.1515/raon-2015-0014 Text en Copyright © by Association of Radiology & Oncology http://creativecommons.org/licenses/by/3.0 This article is an open-access article distributed under the terms and conditions of the Creative Commons Attribution license (http://creativecommons.org/licenses/by/3.0/).
spellingShingle Research Article
Suljic, Alen
Tomse, Petra
Jensterle, Luka
Skrk, Damijan
The impact of reconstruction algorithms and time of flight information on PET/CT image quality
title The impact of reconstruction algorithms and time of flight information on PET/CT image quality
title_full The impact of reconstruction algorithms and time of flight information on PET/CT image quality
title_fullStr The impact of reconstruction algorithms and time of flight information on PET/CT image quality
title_full_unstemmed The impact of reconstruction algorithms and time of flight information on PET/CT image quality
title_short The impact of reconstruction algorithms and time of flight information on PET/CT image quality
title_sort impact of reconstruction algorithms and time of flight information on pet/ct image quality
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4577218/
https://www.ncbi.nlm.nih.gov/pubmed/26401127
http://dx.doi.org/10.1515/raon-2015-0014
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