Is the image quality of I-124-PET impaired by an automatic correction of prompt gammas?
OBJECTIVES: The aim of this study is to evaluate the quality of I-124 PET images with and without prompt gamma compensation (PGC) by comparing the recovery coefficients (RC), the signal to noise ratios (SNR) and the contrast to F-18 and Ga-68. Furthermore, the influence of the PGC on the quantificat...
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doaj-b33ab7199873423e9bd66f3a18d75da42020-11-25T02:22:53ZengPublic Library of Science (PLoS)PLoS ONE1932-62032013-01-0188e7172910.1371/journal.pone.0071729Is the image quality of I-124-PET impaired by an automatic correction of prompt gammas?Veronika PreylowskiSusanne SchlöglFrédéric SchoenahlGerhard JörgSamuel SamnickAndreas K BuckMichael LassmannOBJECTIVES: The aim of this study is to evaluate the quality of I-124 PET images with and without prompt gamma compensation (PGC) by comparing the recovery coefficients (RC), the signal to noise ratios (SNR) and the contrast to F-18 and Ga-68. Furthermore, the influence of the PGC on the quantification and image quality is evaluated. METHODS: For measuring the image quality the NEMA NU2-2001 PET/SPECT-Phantom was used containing 6 spheres with a diameter between 10 mm and 37 mm placed in water with different levels of background activity. Each sphere was filled with the same activity concentration measured by an independently cross-calibrated dose calibrator. The "hot" sources were acquired with a full 3D PET/CT (Biograph mCT®, Siemens Medical USA). Acquisition times were 2 min for F-18 and Ga-68, and 10 min for I-124. For reconstruction an OSEM algorithm was applied. For I-124 the images were reconstructed with and without PGC. For the calculation of the RCs the activity concentrations in each sphere were determined; in addition, the influence of the background correction was studied. RESULTS: The RCs of Ga-68 are the smallest (79%). I-124 reaches similar RCs (87% with PGC, 84% without PGC) as F-18 (84%). showing that the quantification of I-124 images is similar to F-18 and slightly better than Ga-68. With background activity the contrast of the I-124 PGC images is similar to Ga-68 and F-18 scans. There was lower background activity in the I-124 images without PGC, which probably originates from an overcorrection of the scatter contribution. Consequently, the contrast without PGC was much higher than with PGC. As a consequence PGC should be used for I-124. CONCLUSIONS: For I-124 there is only a slight influence on the quantification depending on the use of the PGC. However, there are considerable differences with respect to I-124 image quality.http://europepmc.org/articles/PMC3754939?pdf=render |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Veronika Preylowski Susanne Schlögl Frédéric Schoenahl Gerhard Jörg Samuel Samnick Andreas K Buck Michael Lassmann |
spellingShingle |
Veronika Preylowski Susanne Schlögl Frédéric Schoenahl Gerhard Jörg Samuel Samnick Andreas K Buck Michael Lassmann Is the image quality of I-124-PET impaired by an automatic correction of prompt gammas? PLoS ONE |
author_facet |
Veronika Preylowski Susanne Schlögl Frédéric Schoenahl Gerhard Jörg Samuel Samnick Andreas K Buck Michael Lassmann |
author_sort |
Veronika Preylowski |
title |
Is the image quality of I-124-PET impaired by an automatic correction of prompt gammas? |
title_short |
Is the image quality of I-124-PET impaired by an automatic correction of prompt gammas? |
title_full |
Is the image quality of I-124-PET impaired by an automatic correction of prompt gammas? |
title_fullStr |
Is the image quality of I-124-PET impaired by an automatic correction of prompt gammas? |
title_full_unstemmed |
Is the image quality of I-124-PET impaired by an automatic correction of prompt gammas? |
title_sort |
is the image quality of i-124-pet impaired by an automatic correction of prompt gammas? |
publisher |
Public Library of Science (PLoS) |
series |
PLoS ONE |
issn |
1932-6203 |
publishDate |
2013-01-01 |
description |
OBJECTIVES: The aim of this study is to evaluate the quality of I-124 PET images with and without prompt gamma compensation (PGC) by comparing the recovery coefficients (RC), the signal to noise ratios (SNR) and the contrast to F-18 and Ga-68. Furthermore, the influence of the PGC on the quantification and image quality is evaluated. METHODS: For measuring the image quality the NEMA NU2-2001 PET/SPECT-Phantom was used containing 6 spheres with a diameter between 10 mm and 37 mm placed in water with different levels of background activity. Each sphere was filled with the same activity concentration measured by an independently cross-calibrated dose calibrator. The "hot" sources were acquired with a full 3D PET/CT (Biograph mCT®, Siemens Medical USA). Acquisition times were 2 min for F-18 and Ga-68, and 10 min for I-124. For reconstruction an OSEM algorithm was applied. For I-124 the images were reconstructed with and without PGC. For the calculation of the RCs the activity concentrations in each sphere were determined; in addition, the influence of the background correction was studied. RESULTS: The RCs of Ga-68 are the smallest (79%). I-124 reaches similar RCs (87% with PGC, 84% without PGC) as F-18 (84%). showing that the quantification of I-124 images is similar to F-18 and slightly better than Ga-68. With background activity the contrast of the I-124 PGC images is similar to Ga-68 and F-18 scans. There was lower background activity in the I-124 images without PGC, which probably originates from an overcorrection of the scatter contribution. Consequently, the contrast without PGC was much higher than with PGC. As a consequence PGC should be used for I-124. CONCLUSIONS: For I-124 there is only a slight influence on the quantification depending on the use of the PGC. However, there are considerable differences with respect to I-124 image quality. |
url |
http://europepmc.org/articles/PMC3754939?pdf=render |
work_keys_str_mv |
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