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Silicon photon-counting detector for full-field CT using an ASIC with adjustable shaping time

Purpose: Photon-counting silicon strip detectors are attracting interest for use in next-generation CT scanners. For CT detectors in a clinical environment, it is desirable to have a low power consumption. However, decreasing the power consumption leads to higher noise. This is particularly detrimen...

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Autores principales: Sundberg, Christel, Persson, Mats, Sjölin, Martin, Wikner, J. Jacob, Danielsson, Mats
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Society of Photo-Optical Instrumentation Engineers 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7536358/
https://www.ncbi.nlm.nih.gov/pubmed/33033734
http://dx.doi.org/10.1117/1.JMI.7.5.053503
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author Sundberg, Christel
Persson, Mats
Sjölin, Martin
Wikner, J. Jacob
Danielsson, Mats
author_facet Sundberg, Christel
Persson, Mats
Sjölin, Martin
Wikner, J. Jacob
Danielsson, Mats
author_sort Sundberg, Christel
collection PubMed
description Purpose: Photon-counting silicon strip detectors are attracting interest for use in next-generation CT scanners. For CT detectors in a clinical environment, it is desirable to have a low power consumption. However, decreasing the power consumption leads to higher noise. This is particularly detrimental for silicon detectors, which require a low noise floor to obtain a good dose efficiency. The increase in noise can be mitigated using a longer shaping time in the readout electronics. This also results in longer pulses, which requires an increased deadtime, thereby degrading the count-rate performance. However, as the photon flux varies greatly during a typical CT scan, not all projection lines require a high count-rate capability. We propose adjusting the shaping time to counteract the increased noise that results from decreasing the power consumption. Approach: To show the potential of increasing the shaping time to decrease the noise level, synchrotron measurements were performed using a detector prototype with two shaping time settings. From the measurements, a simulation model was developed and used to predict the performance of a future channel design. Results: Based on the synchrotron measurements, we show that increasing the shaping time from 28.1 to 39.4 ns decreases the noise and increases the signal-to-noise ratio with 6.5% at low count rates. With the developed simulation model, we predict that a 50% decrease in power can be attained in a proposed future detector design by increasing the shaping time with a factor of 1.875. Conclusion: Our results show that the shaping time can be an important tool to adapt the pulse length and noise level to the photon flux and thereby optimize the dose efficiency of photon-counting silicon detectors.
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spelling pubmed-75363582021-10-06 Silicon photon-counting detector for full-field CT using an ASIC with adjustable shaping time Sundberg, Christel Persson, Mats Sjölin, Martin Wikner, J. Jacob Danielsson, Mats J Med Imaging (Bellingham) Physics of Medical Imaging Purpose: Photon-counting silicon strip detectors are attracting interest for use in next-generation CT scanners. For CT detectors in a clinical environment, it is desirable to have a low power consumption. However, decreasing the power consumption leads to higher noise. This is particularly detrimental for silicon detectors, which require a low noise floor to obtain a good dose efficiency. The increase in noise can be mitigated using a longer shaping time in the readout electronics. This also results in longer pulses, which requires an increased deadtime, thereby degrading the count-rate performance. However, as the photon flux varies greatly during a typical CT scan, not all projection lines require a high count-rate capability. We propose adjusting the shaping time to counteract the increased noise that results from decreasing the power consumption. Approach: To show the potential of increasing the shaping time to decrease the noise level, synchrotron measurements were performed using a detector prototype with two shaping time settings. From the measurements, a simulation model was developed and used to predict the performance of a future channel design. Results: Based on the synchrotron measurements, we show that increasing the shaping time from 28.1 to 39.4 ns decreases the noise and increases the signal-to-noise ratio with 6.5% at low count rates. With the developed simulation model, we predict that a 50% decrease in power can be attained in a proposed future detector design by increasing the shaping time with a factor of 1.875. Conclusion: Our results show that the shaping time can be an important tool to adapt the pulse length and noise level to the photon flux and thereby optimize the dose efficiency of photon-counting silicon detectors. Society of Photo-Optical Instrumentation Engineers 2020-10-06 2020-09 /pmc/articles/PMC7536358/ /pubmed/33033734 http://dx.doi.org/10.1117/1.JMI.7.5.053503 Text en © 2020 The Authors https://creativecommons.org/licenses/by/4.0/ Published by SPIE under a Creative Commons Attribution 4.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.
spellingShingle Physics of Medical Imaging
Sundberg, Christel
Persson, Mats
Sjölin, Martin
Wikner, J. Jacob
Danielsson, Mats
Silicon photon-counting detector for full-field CT using an ASIC with adjustable shaping time
title Silicon photon-counting detector for full-field CT using an ASIC with adjustable shaping time
title_full Silicon photon-counting detector for full-field CT using an ASIC with adjustable shaping time
title_fullStr Silicon photon-counting detector for full-field CT using an ASIC with adjustable shaping time
title_full_unstemmed Silicon photon-counting detector for full-field CT using an ASIC with adjustable shaping time
title_short Silicon photon-counting detector for full-field CT using an ASIC with adjustable shaping time
title_sort silicon photon-counting detector for full-field ct using an asic with adjustable shaping time
topic Physics of Medical Imaging
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7536358/
https://www.ncbi.nlm.nih.gov/pubmed/33033734
http://dx.doi.org/10.1117/1.JMI.7.5.053503
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