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Limits of Tumor Detectability in Nuclear Medicine and PET

Objective: Nuclear medicine is becoming increasingly important in the early detection of malignancy. The advantage of nuclear medicine over other imaging modalities is the high sensitivity of the gamma camera. Nuclear medicine counting equipment has the capability of detecting levels of radioactivit...

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Autor principal: Erdi, Yusuf Emre
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Galenos Publishing 2012
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3590963/
https://www.ncbi.nlm.nih.gov/pubmed/23486256
http://dx.doi.org/10.4274/Mirt.138
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author Erdi, Yusuf Emre
author_facet Erdi, Yusuf Emre
author_sort Erdi, Yusuf Emre
collection PubMed
description Objective: Nuclear medicine is becoming increasingly important in the early detection of malignancy. The advantage of nuclear medicine over other imaging modalities is the high sensitivity of the gamma camera. Nuclear medicine counting equipment has the capability of detecting levels of radioactivity which exceed background levels by as little as 2.4 to 1. This translates to only a few hundred counts per minute on a regular gamma camera or as few as 3 counts per minute when using coincidence detection on a positron emission tomography (PET) camera. Material and Methods: We have experimentally measured the limits of detectability using a set of hollow spheres in a Jaszczak phantom at various tumor-to-background ratios. Imaging modalities for this work were (1) planar, (2) SPECT, (3) PET, and (4) planar camera with coincidence detection capability (MCD). Results: When there is no background (infinite contrast) activity present, the detectability of tumors is similar for PET and planar imaging. With the presence of the background activity , PET can detect objects in an order of magnitude smaller in size than that can be seen by conventional planar imaging especially in the typical clinical low (3:1) T/B ratios. The detection capability of the MCD camera lies between a conventional nuclear medicine (planar / SPECT) scans and the detection capability of a dedicated PET scanner. Conclusion: Among nuclear medicine’s armamentarium, PET is the closest modality to CT or MR imaging in terms of limits of detection. Modern clinical PET scanners have a resolution limit of 4 mm, corresponding to the detection of tumors with a volume of 0.2 ml (7 mm diameter) in 5:1 T/B ratio. It is also possible to obtain better resolution limits with dedicated brain and animal scanners. The future holds promise in development of new detector materials, improved camera design, and new reconstruction algorithms which will improve sensitivity, resolution, contrast, and thereby further diminish the limits of tumor detectability. Conflict of interest:None declared.
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spelling pubmed-35909632013-03-13 Limits of Tumor Detectability in Nuclear Medicine and PET Erdi, Yusuf Emre Mol Imaging Radionucl Ther Original Article Objective: Nuclear medicine is becoming increasingly important in the early detection of malignancy. The advantage of nuclear medicine over other imaging modalities is the high sensitivity of the gamma camera. Nuclear medicine counting equipment has the capability of detecting levels of radioactivity which exceed background levels by as little as 2.4 to 1. This translates to only a few hundred counts per minute on a regular gamma camera or as few as 3 counts per minute when using coincidence detection on a positron emission tomography (PET) camera. Material and Methods: We have experimentally measured the limits of detectability using a set of hollow spheres in a Jaszczak phantom at various tumor-to-background ratios. Imaging modalities for this work were (1) planar, (2) SPECT, (3) PET, and (4) planar camera with coincidence detection capability (MCD). Results: When there is no background (infinite contrast) activity present, the detectability of tumors is similar for PET and planar imaging. With the presence of the background activity , PET can detect objects in an order of magnitude smaller in size than that can be seen by conventional planar imaging especially in the typical clinical low (3:1) T/B ratios. The detection capability of the MCD camera lies between a conventional nuclear medicine (planar / SPECT) scans and the detection capability of a dedicated PET scanner. Conclusion: Among nuclear medicine’s armamentarium, PET is the closest modality to CT or MR imaging in terms of limits of detection. Modern clinical PET scanners have a resolution limit of 4 mm, corresponding to the detection of tumors with a volume of 0.2 ml (7 mm diameter) in 5:1 T/B ratio. It is also possible to obtain better resolution limits with dedicated brain and animal scanners. The future holds promise in development of new detector materials, improved camera design, and new reconstruction algorithms which will improve sensitivity, resolution, contrast, and thereby further diminish the limits of tumor detectability. Conflict of interest:None declared. Galenos Publishing 2012-04 2012-04-01 /pmc/articles/PMC3590963/ /pubmed/23486256 http://dx.doi.org/10.4274/Mirt.138 Text en © Molecular Imaging and Radionuclide Therapy, Published by Galenos Publishing. http://creativecommons.org/licenses/by/2.5/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Original Article
Erdi, Yusuf Emre
Limits of Tumor Detectability in Nuclear Medicine and PET
title Limits of Tumor Detectability in Nuclear Medicine and PET
title_full Limits of Tumor Detectability in Nuclear Medicine and PET
title_fullStr Limits of Tumor Detectability in Nuclear Medicine and PET
title_full_unstemmed Limits of Tumor Detectability in Nuclear Medicine and PET
title_short Limits of Tumor Detectability in Nuclear Medicine and PET
title_sort limits of tumor detectability in nuclear medicine and pet
topic Original Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3590963/
https://www.ncbi.nlm.nih.gov/pubmed/23486256
http://dx.doi.org/10.4274/Mirt.138
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