Pub Date : 2013-11-01DOI: 10.1109/NSSMIC.2013.6829266
W. H. Nam, Jihye Kim, I. Ahn, Yongjin Chang, J. Ra
Positron emission tomography (PET) image has been widely used for early detection of malignant lesion(s) and its treatment, because it can provide functional information. Since computed tomography (CT) and magnetic resonance (MR) images can provide high resolution anatomical information, their simultaneous display with PET image may improve the clinical value of PET-image-based applications. Meanwhile, temporal information regarding anatomical changes due to respiration may be important in the radiation therapy planning of a thoracic or abdominal region. To provide such important information, we propose a framework for motion compensated 4D PET-CT-MR image generation. To realize the framework, we present a MR-driven motion compensation algorithm for respiratory-gated 4D PET imaging. We then introduce a respiratory-synchronized multi-modal image generation method. We expect that the respiratory-synchronized multi-modal image display can be useful for clinicians to efficiently utilize the temporal information as well as the complementary spatial information in their applications.
{"title":"Motion compensated 4D PET-CT-MR image generation for respiratory synchronized multi-modal image display","authors":"W. H. Nam, Jihye Kim, I. Ahn, Yongjin Chang, J. Ra","doi":"10.1109/NSSMIC.2013.6829266","DOIUrl":"https://doi.org/10.1109/NSSMIC.2013.6829266","url":null,"abstract":"Positron emission tomography (PET) image has been widely used for early detection of malignant lesion(s) and its treatment, because it can provide functional information. Since computed tomography (CT) and magnetic resonance (MR) images can provide high resolution anatomical information, their simultaneous display with PET image may improve the clinical value of PET-image-based applications. Meanwhile, temporal information regarding anatomical changes due to respiration may be important in the radiation therapy planning of a thoracic or abdominal region. To provide such important information, we propose a framework for motion compensated 4D PET-CT-MR image generation. To realize the framework, we present a MR-driven motion compensation algorithm for respiratory-gated 4D PET imaging. We then introduce a respiratory-synchronized multi-modal image generation method. We expect that the respiratory-synchronized multi-modal image display can be useful for clinicians to efficiently utilize the temporal information as well as the complementary spatial information in their applications.","PeriodicalId":246351,"journal":{"name":"2013 IEEE Nuclear Science Symposium and Medical Imaging Conference (2013 NSS/MIC)","volume":"148 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131435984","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-11-01DOI: 10.1109/NSSMIC.2013.6829796
S. Lee, B. Kross, J. McKisson, J. McKisson, A. Weisenberger, W. Xi, C. Zorn, G. Bonito, C. Howell, C. Reid, A. Crowell, L. Cumberbatch, C. Topp, M. Smith
PhytoPET is a modular positron emission tomography (PET) system designed specifically for plant imaging. The PhytoPET design allows flexible arrangements of PET detectors based on individual standalone detector modules built from single Hamamatsu H8500 position sensitive photomultiplier tubes and pixelated LYSO arrays. We have used the PhytoPET system to perform preliminary corn plant imaging studies at the Duke University Biology Department Phytotron. Initial evaluation of the PhytoPET system to image the biodistribution of the positron emitting tracer 11C in corn plants is presented. 11CO2 is loaded into corn seedlings by a leaf-labeling cuvette and translocation of 11C-sugars is imaged by a flexible arrangement of PhytoPET modules on each side. The PhytoPET system successfully images 11C within corn plants and allows for the dynamic measurement of 11C-sugar translocation from the leaf to the roots.
{"title":"Imaging corn plants with PhytoPET, a modular PET system for plant biology","authors":"S. Lee, B. Kross, J. McKisson, J. McKisson, A. Weisenberger, W. Xi, C. Zorn, G. Bonito, C. Howell, C. Reid, A. Crowell, L. Cumberbatch, C. Topp, M. Smith","doi":"10.1109/NSSMIC.2013.6829796","DOIUrl":"https://doi.org/10.1109/NSSMIC.2013.6829796","url":null,"abstract":"PhytoPET is a modular positron emission tomography (PET) system designed specifically for plant imaging. The PhytoPET design allows flexible arrangements of PET detectors based on individual standalone detector modules built from single Hamamatsu H8500 position sensitive photomultiplier tubes and pixelated LYSO arrays. We have used the PhytoPET system to perform preliminary corn plant imaging studies at the Duke University Biology Department Phytotron. Initial evaluation of the PhytoPET system to image the biodistribution of the positron emitting tracer 11C in corn plants is presented. 11CO2 is loaded into corn seedlings by a leaf-labeling cuvette and translocation of 11C-sugars is imaged by a flexible arrangement of PhytoPET modules on each side. The PhytoPET system successfully images 11C within corn plants and allows for the dynamic measurement of 11C-sugar translocation from the leaf to the roots.","PeriodicalId":246351,"journal":{"name":"2013 IEEE Nuclear Science Symposium and Medical Imaging Conference (2013 NSS/MIC)","volume":"87 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133925537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-11-01DOI: 10.1109/NSSMIC.2013.6829239
I. Ahn, Jihye Kim, W. H. Nam, Yongjin Chang, J. Ra
PET images usually suffer from low spatial resolution due to positron range, photon non-collinearity, scatters inside scintillating crystals, finite dimension of crystals, and so on. To improve the spatial resolution based on wobble scanning, we previously proposed a sinogram-based super-resolution (SR) algorithm based on a space-variant blur matrix. However, the algorithm may cause unwanted resolution loss due to an inevitable interpolation process for preparing even-spaced sinograms. In this paper, we propose a novel and efficient one-step line of response (LOR) based SR framework for 3D PET images. In the framework, we efficiently determine a large number of space-variant PSFs in an image space by using the scanner symmetries and the proposed PSF interpolation scheme based on non-rigid registration. We then obtain a HR image via one-step super-resolved 3D PET image reconstruction with the determined PSFs. Furthermore, we reduce the computational time of GPU-based reconstruction by introducing a parallel-friendly cone-beam based LOR system matrix. The proposed framework provides noticeable improvement on the spatial resolution of PET images with a considerable reduction of computational time.
{"title":"LOR-based reconstruction for super-resolved 3D PET image","authors":"I. Ahn, Jihye Kim, W. H. Nam, Yongjin Chang, J. Ra","doi":"10.1109/NSSMIC.2013.6829239","DOIUrl":"https://doi.org/10.1109/NSSMIC.2013.6829239","url":null,"abstract":"PET images usually suffer from low spatial resolution due to positron range, photon non-collinearity, scatters inside scintillating crystals, finite dimension of crystals, and so on. To improve the spatial resolution based on wobble scanning, we previously proposed a sinogram-based super-resolution (SR) algorithm based on a space-variant blur matrix. However, the algorithm may cause unwanted resolution loss due to an inevitable interpolation process for preparing even-spaced sinograms. In this paper, we propose a novel and efficient one-step line of response (LOR) based SR framework for 3D PET images. In the framework, we efficiently determine a large number of space-variant PSFs in an image space by using the scanner symmetries and the proposed PSF interpolation scheme based on non-rigid registration. We then obtain a HR image via one-step super-resolved 3D PET image reconstruction with the determined PSFs. Furthermore, we reduce the computational time of GPU-based reconstruction by introducing a parallel-friendly cone-beam based LOR system matrix. The proposed framework provides noticeable improvement on the spatial resolution of PET images with a considerable reduction of computational time.","PeriodicalId":246351,"journal":{"name":"2013 IEEE Nuclear Science Symposium and Medical Imaging Conference (2013 NSS/MIC)","volume":"292 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115753212","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-10-31DOI: 10.1109/NSSMIC.2013.6829778
K. Briggl, W. Shen, T. Harion, R. Hagdorn, P. Eckert, T. Klapdor-Kleingrothaus, M. Dorn, H. Schultz-Coulon
KLauS is an ASIC produced in the AMS 0.35μm SiGe technology to read out the charge signals from silicon photomultipliers. Developed as an analog front end for future calorimeters with high granularity as pursued by the AHCAL concept in the CALICE collaboration, the ASIC is supposed to measure the charge signal of the sensors in a large dynamic range and with a high precision. In order to compensate bias and temperature fluctuations of each sensor individually, an 8-bit DAC to tune the voltage at the input terminal is implemented. Using an integrated fast comparator with low jitter, the time information can be measured with sub-nanosecond resolution. The low power consumption of the ASIC can be further decreased using power gating techniques. Future versions of KLauS are under development and will incorporate an ADC with a resolution of up to 12 bit together with blocks for digital data transmission. Most recent characterization results for the KLauS chip are presented as well as results from a KLauS-based test setup developed for mass characterization of scintillator tiles used in the AHCAL test beam program.
{"title":"Characterization results and first applications of KLauS - an ASIC for SiPM charge and fast discrimination readout","authors":"K. Briggl, W. Shen, T. Harion, R. Hagdorn, P. Eckert, T. Klapdor-Kleingrothaus, M. Dorn, H. Schultz-Coulon","doi":"10.1109/NSSMIC.2013.6829778","DOIUrl":"https://doi.org/10.1109/NSSMIC.2013.6829778","url":null,"abstract":"KLauS is an ASIC produced in the AMS 0.35μm SiGe technology to read out the charge signals from silicon photomultipliers. Developed as an analog front end for future calorimeters with high granularity as pursued by the AHCAL concept in the CALICE collaboration, the ASIC is supposed to measure the charge signal of the sensors in a large dynamic range and with a high precision. In order to compensate bias and temperature fluctuations of each sensor individually, an 8-bit DAC to tune the voltage at the input terminal is implemented. Using an integrated fast comparator with low jitter, the time information can be measured with sub-nanosecond resolution. The low power consumption of the ASIC can be further decreased using power gating techniques. Future versions of KLauS are under development and will incorporate an ADC with a resolution of up to 12 bit together with blocks for digital data transmission. Most recent characterization results for the KLauS chip are presented as well as results from a KLauS-based test setup developed for mass characterization of scintillator tiles used in the AHCAL test beam program.","PeriodicalId":246351,"journal":{"name":"2013 IEEE Nuclear Science Symposium and Medical Imaging Conference (2013 NSS/MIC)","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128500603","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-10-31DOI: 10.1109/NSSMIC.2013.6829553
A. Navarro
The trigger of the LHCb experiment consists of two stages: an initial hardware trigger, and a high-level trigger implemented in a farm of CPUs. It reduces the event rate from an input of 15 MHz to around 5 kHz. To maximize efficiencies and minimize biases, the trigger is designed around inclusive selection algorithms, culminating in a novel boosted decision tree which enables the efficient selection of beauty hadron decays based on a robust partial reconstruction of their decay products. The design and performance of these selection algorithms will be discussed in the context of the 2012 data taking. In order to improve performance, the LHCb upgrade aims to significantly increase the rate at which the detector will be read out, and hence shift more of the workload onto the high-level trigger. It is demonstrated that the current high-level trigger architecture will be able to meet this challenge, and the expected efficiencies in several key channels are discussed in context of the LHCb upgrade.
{"title":"The LHCb trigger system: Performance and outlook","authors":"A. Navarro","doi":"10.1109/NSSMIC.2013.6829553","DOIUrl":"https://doi.org/10.1109/NSSMIC.2013.6829553","url":null,"abstract":"The trigger of the LHCb experiment consists of two stages: an initial hardware trigger, and a high-level trigger implemented in a farm of CPUs. It reduces the event rate from an input of 15 MHz to around 5 kHz. To maximize efficiencies and minimize biases, the trigger is designed around inclusive selection algorithms, culminating in a novel boosted decision tree which enables the efficient selection of beauty hadron decays based on a robust partial reconstruction of their decay products. The design and performance of these selection algorithms will be discussed in the context of the 2012 data taking. In order to improve performance, the LHCb upgrade aims to significantly increase the rate at which the detector will be read out, and hence shift more of the workload onto the high-level trigger. It is demonstrated that the current high-level trigger architecture will be able to meet this challenge, and the expected efficiencies in several key channels are discussed in context of the LHCb upgrade.","PeriodicalId":246351,"journal":{"name":"2013 IEEE Nuclear Science Symposium and Medical Imaging Conference (2013 NSS/MIC)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121934724","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-10-29DOI: 10.1109/NSSMIC.2013.6829554
O. Igonkina
The ATLAS trigger system plays a key role in the collection of data for a wide range of physics analyses. The 2012 proton run had significantly larger luminosities and pile-up than the 2011 run. To address these challenges while maintaining or even improving performance, new algorithms have been commissioned. The trigger strategy and the main algorithms and their performance are described. For the 2015 run, the combination of a luminosity increase and an energy increase will put even larger demands on the trigger system. We describe here modifications to the trigger system to address these demands both at the hardware and software levels.
{"title":"ATLAS trigger menu and performance in Run 1 and prospects for Run 2","authors":"O. Igonkina","doi":"10.1109/NSSMIC.2013.6829554","DOIUrl":"https://doi.org/10.1109/NSSMIC.2013.6829554","url":null,"abstract":"The ATLAS trigger system plays a key role in the collection of data for a wide range of physics analyses. The 2012 proton run had significantly larger luminosities and pile-up than the 2011 run. To address these challenges while maintaining or even improving performance, new algorithms have been commissioned. The trigger strategy and the main algorithms and their performance are described. For the 2015 run, the combination of a luminosity increase and an energy increase will put even larger demands on the trigger system. We describe here modifications to the trigger system to address these demands both at the hardware and software levels.","PeriodicalId":246351,"journal":{"name":"2013 IEEE Nuclear Science Symposium and Medical Imaging Conference (2013 NSS/MIC)","volume":"134 5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131035035","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-10-29DOI: 10.1109/NSSMIC.2013.6829593
A. Gostojić, V. Tatischeff, J. Kiener, C. Hamadache, N. Karkour, D. Linget, G. Sedes, S. Blin, P. Barrillon
The new generation of high light-output inorganic scintillators i.e. cerium-doped lanthanum(III) bromide (LaBr3:Ce) show a promising future in application as a space-based γ-ray calorimeter. Its internal qualities such as good energy resolution or radiation tolerance are well suited for detection of γ-rays in the MeV range, thus providing access to, so far, understudied questions in physics of nucleosynthesis, the active Sun or astrophysical compact objects. For this purpose, under the project of creating a new Compton telescope prototype, we have studied the response of a detection module comprising a 5×5 cm2 area and 1 cm thick LaBr3:Ce crystal scintillator coupled to a 64 channel multi-anode photomultiplier read out by the ASIC MAROC. Measurements with various radioactive sources have been compared with detailed GEANT4 simulations that include the tracking of the near-UV photons produced in the scintillation crystal. The localization of the first interaction point of incident γ-rays have been studied from the measured charge distributions using an artificial neural network. Together with the other measured properties, the position resolution that we obtain makes this detector module very interesting for the next generation of space telescopes operating in the medium-energy γ-ray domain.
{"title":"Development of a 3D imaging calorimeter in lanthanum bromide for gamma-ray space astronomy","authors":"A. Gostojić, V. Tatischeff, J. Kiener, C. Hamadache, N. Karkour, D. Linget, G. Sedes, S. Blin, P. Barrillon","doi":"10.1109/NSSMIC.2013.6829593","DOIUrl":"https://doi.org/10.1109/NSSMIC.2013.6829593","url":null,"abstract":"The new generation of high light-output inorganic scintillators i.e. cerium-doped lanthanum(III) bromide (LaBr3:Ce) show a promising future in application as a space-based γ-ray calorimeter. Its internal qualities such as good energy resolution or radiation tolerance are well suited for detection of γ-rays in the MeV range, thus providing access to, so far, understudied questions in physics of nucleosynthesis, the active Sun or astrophysical compact objects. For this purpose, under the project of creating a new Compton telescope prototype, we have studied the response of a detection module comprising a 5×5 cm2 area and 1 cm thick LaBr3:Ce crystal scintillator coupled to a 64 channel multi-anode photomultiplier read out by the ASIC MAROC. Measurements with various radioactive sources have been compared with detailed GEANT4 simulations that include the tracking of the near-UV photons produced in the scintillation crystal. The localization of the first interaction point of incident γ-rays have been studied from the measured charge distributions using an artificial neural network. Together with the other measured properties, the position resolution that we obtain makes this detector module very interesting for the next generation of space telescopes operating in the medium-energy γ-ray domain.","PeriodicalId":246351,"journal":{"name":"2013 IEEE Nuclear Science Symposium and Medical Imaging Conference (2013 NSS/MIC)","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127764362","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-10-27DOI: 10.1109/NSSMIC.2013.6829246
Long Chen, T. Rodet, N. Gac
For metal artifact reduction (MAR) in X-ray cone-beam computed tomography (CBCT), we propose a penalized weighted least-squares (PWLS) image reconstruction method [1] based on scatter correction (SC) method. Our main contribution is to incorporate the inaccuracy of the scatter correction data in PWLS method, and to accelerate the PWLS image reconstruction with a preconditioned conjugate gradient (PCG) method [2]. The reconstruction results of both the simulation and experimental data show that our proposed method effectively reduces the metal artifacts (MA). Compared to the state of art, normalized metal artifact reduction (NMAR) method [3], our method prevents the introduction of some new artifacts due to an inappropriate interpolation possible used in NMAR.
{"title":"A penalized weighted least-squares image reconstruction based on scatter correction methods for X-ray CT","authors":"Long Chen, T. Rodet, N. Gac","doi":"10.1109/NSSMIC.2013.6829246","DOIUrl":"https://doi.org/10.1109/NSSMIC.2013.6829246","url":null,"abstract":"For metal artifact reduction (MAR) in X-ray cone-beam computed tomography (CBCT), we propose a penalized weighted least-squares (PWLS) image reconstruction method [1] based on scatter correction (SC) method. Our main contribution is to incorporate the inaccuracy of the scatter correction data in PWLS method, and to accelerate the PWLS image reconstruction with a preconditioned conjugate gradient (PCG) method [2]. The reconstruction results of both the simulation and experimental data show that our proposed method effectively reduces the metal artifacts (MA). Compared to the state of art, normalized metal artifact reduction (NMAR) method [3], our method prevents the introduction of some new artifacts due to an inappropriate interpolation possible used in NMAR.","PeriodicalId":246351,"journal":{"name":"2013 IEEE Nuclear Science Symposium and Medical Imaging Conference (2013 NSS/MIC)","volume":"62 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130740608","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-10-27DOI: 10.1109/NSSMIC.2013.6829242
A. Autret, J. Bert, O. Strauss, D. Visvikis
In list-mode PET reconstruction the projector is an operator that computes on-the-fly the spatial detector response related to a specific line-of-response (LOR). In the literature, many projectors with PSF modeling have been proposed with different levels of accuracy. A recently proposed projector based on the random sampling of the intrinsic detector response function was shown to accurately model all detector effects including geometry and crystal scatter. Recent PET scanners have the capability to measure the difference in the time arrival of the annihilation gamma photon pairs, also called time-of-flight (TOF). Many studies have shown the benefits, in terms of image quality, from the use of the TOF within the reconstruction process. In this study we evaluate the impact of including TOF information within a projector that includes a full modeling of the detector response. A comparative study with non-TOF image reconstruction using a projector with no (Siddon) and a less accurate (Gaussian) detector PSF modeling was also included in this study. All reconstruction algorithms were implemented on multi-GPUs. Results have shown that combining both TOF and PSF allows a double benefit on the reconstructed images. Contrast recovery was improved by nearly a factor of two, and overall execution times including TOF information were reduced by half compared to corresponding non-TOF reconstructions.
{"title":"Incorporation of time-of-flight information in PET list-mode reconstruction using a projector with accurate detector PSF modeling","authors":"A. Autret, J. Bert, O. Strauss, D. Visvikis","doi":"10.1109/NSSMIC.2013.6829242","DOIUrl":"https://doi.org/10.1109/NSSMIC.2013.6829242","url":null,"abstract":"In list-mode PET reconstruction the projector is an operator that computes on-the-fly the spatial detector response related to a specific line-of-response (LOR). In the literature, many projectors with PSF modeling have been proposed with different levels of accuracy. A recently proposed projector based on the random sampling of the intrinsic detector response function was shown to accurately model all detector effects including geometry and crystal scatter. Recent PET scanners have the capability to measure the difference in the time arrival of the annihilation gamma photon pairs, also called time-of-flight (TOF). Many studies have shown the benefits, in terms of image quality, from the use of the TOF within the reconstruction process. In this study we evaluate the impact of including TOF information within a projector that includes a full modeling of the detector response. A comparative study with non-TOF image reconstruction using a projector with no (Siddon) and a less accurate (Gaussian) detector PSF modeling was also included in this study. All reconstruction algorithms were implemented on multi-GPUs. Results have shown that combining both TOF and PSF allows a double benefit on the reconstructed images. Contrast recovery was improved by nearly a factor of two, and overall execution times including TOF information were reduced by half compared to corresponding non-TOF reconstructions.","PeriodicalId":246351,"journal":{"name":"2013 IEEE Nuclear Science Symposium and Medical Imaging Conference (2013 NSS/MIC)","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130952778","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2013-10-27DOI: 10.1109/NSSMIC.2013.6829622
H. Yoo, C. Kim, Y. Kim, J. Kim, M. Kim, D. Lee, M. Cho, H. Kim, K. Park, D. Kang, S. Park, G. Cho
A Silicon Photo Multiplier (SiPM) is states of arts radiation detector, it is alternative to PM-Tube. But, availability research of SiPM is not entirely satisfactory. In this study, we suggest the radiation detector module coupled with the SiPM and the plastic scintillator, and then, evaluate the availability of detector module for Cs-137 dosimetry. To confirm the dosimetry characteristics, we experimented count difference depends on equivalent dose rate and equivalent dose comparing with MCNP calculation, and, calculating the conversion coefficient depends on count rate and total count that finding the region keeps the linearity of calculating the dose. These experiment results means the SiPM with the plastic scintillator is able to use the dosimetry application for Cs-137. New detector module has the advantages that smaller volume than GM Tube and ion chamber and the lower price than indirect detector module using inorganic scintillator as CsI(TI). So, it will helpful to relieving the public anxiety about radiation exposure by popularizing the dosimetry device.
{"title":"Evaluation of dosimetry characteristics of a Silicon Photo-Multiplier with a plastic scintillator by Cs-137","authors":"H. Yoo, C. Kim, Y. Kim, J. Kim, M. Kim, D. Lee, M. Cho, H. Kim, K. Park, D. Kang, S. Park, G. Cho","doi":"10.1109/NSSMIC.2013.6829622","DOIUrl":"https://doi.org/10.1109/NSSMIC.2013.6829622","url":null,"abstract":"A Silicon Photo Multiplier (SiPM) is states of arts radiation detector, it is alternative to PM-Tube. But, availability research of SiPM is not entirely satisfactory. In this study, we suggest the radiation detector module coupled with the SiPM and the plastic scintillator, and then, evaluate the availability of detector module for Cs-137 dosimetry. To confirm the dosimetry characteristics, we experimented count difference depends on equivalent dose rate and equivalent dose comparing with MCNP calculation, and, calculating the conversion coefficient depends on count rate and total count that finding the region keeps the linearity of calculating the dose. These experiment results means the SiPM with the plastic scintillator is able to use the dosimetry application for Cs-137. New detector module has the advantages that smaller volume than GM Tube and ion chamber and the lower price than indirect detector module using inorganic scintillator as CsI(TI). So, it will helpful to relieving the public anxiety about radiation exposure by popularizing the dosimetry device.","PeriodicalId":246351,"journal":{"name":"2013 IEEE Nuclear Science Symposium and Medical Imaging Conference (2013 NSS/MIC)","volume":"60 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134146178","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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