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Scanner and kVp dependence of measured CT numbers in the ACR CT phantom

Quality control testing of CT scanners in our region includes a measurement of CT numbers in the American College of Radiology (ACR) CT phantom using a standardized protocol. CT number values are clinically relevant in determining the composition of various tissues in the body. Accuracy is important...

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Autores principales: Cropp, Robert J., Seslija, Petar, Tso, David, Thakur, Yogesh
Formato: Online Artículo Texto
Lenguaje:English
Publicado: John Wiley and Sons Inc. 2013
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5714621/
https://www.ncbi.nlm.nih.gov/pubmed/24257284
http://dx.doi.org/10.1120/jacmp.v14i6.4417
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author Cropp, Robert J.
Seslija, Petar
Tso, David
Thakur, Yogesh
author_facet Cropp, Robert J.
Seslija, Petar
Tso, David
Thakur, Yogesh
author_sort Cropp, Robert J.
collection PubMed
description Quality control testing of CT scanners in our region includes a measurement of CT numbers in the American College of Radiology (ACR) CT phantom using a standardized protocol. CT number values are clinically relevant in determining the composition of various tissues in the body. Accuracy is important in the characterization of tumors, assessment of coronary calcium, and identification of urinary stone composition. Effective quality control requires that tolerance ranges of CT number values be defined: a measured value outside the range indicates the need for further investigation and possible recalibration of the scanner. This paper presents the results of CT number measurements on 36 scanners (25 GE, 10 Siemens and 1 Toshiba) at each available kVp. Among the five materials (solid water, air, polyethylene, acrylic, bone‐equivalent) the measured CT numbers exhibit manufacturer and kVp dependence, which should be taken into account when defining tolerances. With this scan protocol, air and solid water values are significantly higher on GE scanners than on Siemens scanners ([Formula: see text] at each kVp). The CT numbers of polyethylene and acrylic increase with kVp, while the bone‐equivalent CT number decreases. These results are used to define manufacturer‐ and kVp‐specific tolerance ranges for the CT numbers of each material in this phantom, which will be used in our quality control program. PACS numbers: 87.57.qp, 87.57.C‐
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spelling pubmed-57146212018-04-02 Scanner and kVp dependence of measured CT numbers in the ACR CT phantom Cropp, Robert J. Seslija, Petar Tso, David Thakur, Yogesh J Appl Clin Med Phys Medical Imaging Quality control testing of CT scanners in our region includes a measurement of CT numbers in the American College of Radiology (ACR) CT phantom using a standardized protocol. CT number values are clinically relevant in determining the composition of various tissues in the body. Accuracy is important in the characterization of tumors, assessment of coronary calcium, and identification of urinary stone composition. Effective quality control requires that tolerance ranges of CT number values be defined: a measured value outside the range indicates the need for further investigation and possible recalibration of the scanner. This paper presents the results of CT number measurements on 36 scanners (25 GE, 10 Siemens and 1 Toshiba) at each available kVp. Among the five materials (solid water, air, polyethylene, acrylic, bone‐equivalent) the measured CT numbers exhibit manufacturer and kVp dependence, which should be taken into account when defining tolerances. With this scan protocol, air and solid water values are significantly higher on GE scanners than on Siemens scanners ([Formula: see text] at each kVp). The CT numbers of polyethylene and acrylic increase with kVp, while the bone‐equivalent CT number decreases. These results are used to define manufacturer‐ and kVp‐specific tolerance ranges for the CT numbers of each material in this phantom, which will be used in our quality control program. PACS numbers: 87.57.qp, 87.57.C‐ John Wiley and Sons Inc. 2013-11-04 /pmc/articles/PMC5714621/ /pubmed/24257284 http://dx.doi.org/10.1120/jacmp.v14i6.4417 Text en © 2013 The Authors. This is an open access article under the terms of the Creative Commons Attribution (http://creativecommons.org/licenses/by/3.0/) License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
spellingShingle Medical Imaging
Cropp, Robert J.
Seslija, Petar
Tso, David
Thakur, Yogesh
Scanner and kVp dependence of measured CT numbers in the ACR CT phantom
title Scanner and kVp dependence of measured CT numbers in the ACR CT phantom
title_full Scanner and kVp dependence of measured CT numbers in the ACR CT phantom
title_fullStr Scanner and kVp dependence of measured CT numbers in the ACR CT phantom
title_full_unstemmed Scanner and kVp dependence of measured CT numbers in the ACR CT phantom
title_short Scanner and kVp dependence of measured CT numbers in the ACR CT phantom
title_sort scanner and kvp dependence of measured ct numbers in the acr ct phantom
topic Medical Imaging
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5714621/
https://www.ncbi.nlm.nih.gov/pubmed/24257284
http://dx.doi.org/10.1120/jacmp.v14i6.4417
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