2020 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC)最新文献

{"title":"Digital Read-Out Modules of CRYO System-an-Chip ASIC for Cryogenic TPC Detectors","authors":"Aseem Gupta, A. Pena-Perez, B. Markovic, C. Tamma, D. Doering, Hussein Ali, Umanath Kamath, P. Caragiulo, L. Rota, S. Petrignani, Xiaobin Xu, F. Abu-Nimeh, B. Reese, A. Dragone","doi":"10.1109/NSS/MIC42677.2020.9508032","DOIUrl":"https://doi.org/10.1109/NSS/MIC42677.2020.9508032","url":null,"abstract":"This work describes the primary modules of the digital read-out system implemented in a System-On-Chip (SoC) ASIC optimized for noble liquid Time Projection Chambers (TPCs). The ASIC, referred here as CRYO, performs digital and analog functions and has been designed as the charge read-out system for neutrino science experiments. The digital back-end of the chip provides data throughput up to 1 Gbps and operates with cryogenic liquids (Liquid Xenon, 160 K and Liquid Argon, 87 K). The ASIC is fabricated with 130 nm CMOS technology and the read-out process implements a sequential digital multiplexer, a custom encoder, a high-speed serializer, and LVDS (Low-Voltage Differential Signaling) drivers assisted with pre-emphasis techniques to preserve signal integrity up to 25 m cable length. The back-end system is fully programmable through a dedicated slow control unit interface to operate across temperatures and different cable lengths. A subset of simulation results of the readout of CRYO at target temperatures are validated using a custom verification flow.","PeriodicalId":6760,"journal":{"name":"2020 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC)","volume":"88 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2020-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81437048","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}

{"title":"Multigrid Reconstruction Technique for X-ray Fluorescence Computed Tomography","authors":"Bo Gao, L. Van Hoorebeke, L. Vincze, M. Boone","doi":"10.1109/NSS/MIC42677.2020.9507913","DOIUrl":"https://doi.org/10.1109/NSS/MIC42677.2020.9507913","url":null,"abstract":"X-ray Fluorescence Computed Tomography (XFCT) is an imaging modality aiming at mapping the elemental distribution inside the sample non-invasively. However, the self-absorption effect associated with XFCT makes the accurate reconstruction challenging. To solve this issue, reconstruction algorithms that compensates this effect have been proposed. Due to the computational complexity, almost all algorithms proposed for XFCT reconstruction have modelled XFCT in a 2D plane, which is an approximation only accurate in limited cases. In this manuscript, the limitation of modelling XFCT in a 2D plane is demonstrated. Then, an effective method for the acceleration of XFCT reconstruction in the 3D space, namely multigrid XFCT reconstruction, is proposed. Specifically, multigrid refers to the different discretization grids, on which the elemental distributions and the attenuation coefficients at the energies of fluorescence X-rays are reconstructed. Through test, it can be shown that an accurate density distribution could be obtained even if the attenuation coefficients have been reconstructed on a coarser grid. As the multigrid reconstruction strategy is independent of the methodology behind the reconstruction algorithms, it could be used to accelerate all XFCT reconstruction algorithms that simultaneously reconstruct the elemental density and the attenuation coefficients at the energies of fluorescence X-rays.","PeriodicalId":6760,"journal":{"name":"2020 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC)","volume":"1 1","pages":"1-8"},"PeriodicalIF":0.0,"publicationDate":"2020-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82249038","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}

{"title":"Compton Camera Imaging Sensitivity with Improved Event Selection","authors":"M. Mikeli, Mina-Ermioni Tomazinaki, E. Stiliaris","doi":"10.1109/NSS/MIC42677.2020.9507802","DOIUrl":"https://doi.org/10.1109/NSS/MIC42677.2020.9507802","url":null,"abstract":"Besides the noiseless extraction of the energy deposited in the absorber, an ideal event reconstruction in a Compton-Camera system requires the accurate determination of both interaction points in the scatterer and absorber. Limited energy and spatial resolution of the system combined with other misidentification effects leads frequently to the acceptance of faulty events, which affect the quality of the reconstructed image. Based on GEANT4/GATE simulation studies, a filtering procedure to eliminate energy and spatially unbalanced events is proposed in the current work. Attention has been paid to exclude from the coincidence selection procedure events that alternate the normal interaction sequence in the scatterer-absorber subsystems or violate total energy sum rules. Following the proposed filtering approach, volume effects traced back to the angular acceptance of a two-stage Compton-Camera system are systematically investigated and a normalization-correction technique to improve the performance of the system for phantoms with out-of-plane sources is presented.","PeriodicalId":6760,"journal":{"name":"2020 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC)","volume":"9 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2020-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76299467","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}

{"title":"Hybrid Spectral and Image Deconvolution for High-Resolution CZT Imaging Spectrometers","authors":"C. Wahl, S. Brown, B. Kitchen, Weiyi Wang, W. Kaye","doi":"10.1109/NSS/MIC42677.2020.9508056","DOIUrl":"https://doi.org/10.1109/NSS/MIC42677.2020.9508056","url":null,"abstract":"Large-volume 3D-position-sensitive CdZnTe is used in many applications for spectroscopy and Compton imaging. Being able to determine the incident gamma-ray flux, as a function of both the energy and direction, is, of course, a useful feature to provide more information from each measurement. Deconvolution in the energy domain should be able to identify emission lines and continuous distributions over energy. Deconvolution in the direction domain should be able to identify point sources and distributed sources. In this work, a hybrid deconvolution method is introduced, which uses the image to improve the spectral deconvolution and the spectrum to improve the image deconvolution, while still being fast enough to run on practical problems. Details of the deconvolution method are presented along with representative results.","PeriodicalId":6760,"journal":{"name":"2020 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC)","volume":"28 1","pages":"1-3"},"PeriodicalIF":0.0,"publicationDate":"2020-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87980478","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}

{"title":"A Novel Concept for PET Scanners Design using Polaroid-based Detectors for Filtering Reflected Optical Photons","authors":"Amirhossein Sanaat, Aydin Ashrafi-Belgabad, H. Zaidi","doi":"10.1109/NSS/MIC42677.2020.9508069","DOIUrl":"https://doi.org/10.1109/NSS/MIC42677.2020.9508069","url":null,"abstract":"The aim of this work is to propose and assess a new detector module for an animal PET scanner, called Polaroid-PET. Polaroid-PET's detector modules consist of monolithic crystals on which a layer of Polaroid sheet is stick on one side to filter unpolarized optical photons. The polaroid sheet filter reflects optical photons and thus enhances the spatial resolution in the detector module based on monolithic scintillator crystals. In the initial step, the GEANT4 Monte Carlo toolkit is used to simulate a detector block consisting of a lutecium-based monolithic crystal (LYSO) with a crystal thickness of 10 mm and semiconductor-based Silicon Photomultipliers. A Polaroid sheet was placed between the crystal and the SiPMs to block unpolarized photons come from the crystal. In the next step, two preclinical PET scanners with and without Polaroid based on 10 detector modules were simulated. The performance of the two detector modules and preclinical PET scanners were assessed by calculating the spatial resolution, and depth of interaction (DOI). The Polaroid-equipped detector module resulted in a better spatial resolution with ~1.05 mm full-width at half maximum (FWHM) compared with the regular detector (~1.3 mm FHWM) for a point source placed in front of the center of the detector's entrance face. Our Polaroid-based PET scanner led to better axial spatial resolution in comparison with the regular small-animal PET scanner for a point source placed at the center of the field-of-view (0.83 mm vs. 1.01 mm FWHM). By filtering reflected unpolarized optical photons, Polaroid-PET was able to achieve improved spatial resolution and sensitivity compared to the original design.","PeriodicalId":6760,"journal":{"name":"2020 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC)","volume":"11 1","pages":"1-3"},"PeriodicalIF":0.0,"publicationDate":"2020-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86411885","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}

{"title":"Measurement of Discharge Events Due to Voltage Breakdown in High-Voltage Ceramic Feedthroughs","authors":"E. Yamamoto, S. Shermer, A. Hutchinson","doi":"10.1109/NSS/MIC42677.2020.9507934","DOIUrl":"https://doi.org/10.1109/NSS/MIC42677.2020.9507934","url":null,"abstract":"Ceramic insulated hermetic feedthroughs are used as signal and high-voltage conduits for sealed gamma radiation detectors with applications in oil and gas exploration. In configurations where signal and high-voltage are supplied via the same feedthrough, voltage breakdown of the gas filling the gap between the conducting wire and coaxial ceramic insulator may produce a charge pulse that is indistinguishable from a gamma detection pulse. This work describes a method to measure the discrete pulses generated by discharges across an air gap between a conducting wire and a coaxial ceramic insulator at 1600V and 150C ambient temperature. The data presented show results of measurements from discrete discharge events containing between ~0.5 pico-Coulombs and 200 pico-Coulombs of charge per event. Samples were tested that had undergone various operations including welding and soldering. Different cleaning operations were applied to some samples to determine whether discharges could be attributed to surface contamination. Measurements of samples where the ceramic insulator was manufactured using two different forming processes was also performed. This method is shown to provide a sensitive tool to screen hermetic components in radiation detectors used for oil and gas exploration.","PeriodicalId":6760,"journal":{"name":"2020 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC)","volume":"48 1","pages":"1-3"},"PeriodicalIF":0.0,"publicationDate":"2020-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86450401","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}

{"title":"A High-performance Onboard Small Animal PET for Preclinical Radiotherapy Research","authors":"Xinyi Cheng, K. Hu, Dongxu Yang, Y. Shao","doi":"10.1109/NSS/MIC42677.2020.9507964","DOIUrl":"https://doi.org/10.1109/NSS/MIC42677.2020.9507964","url":null,"abstract":"We have developed and evaluated a prototype animal PET dedicated for PET/CT/RT. It consists of 12 detectors configured in a dodecagon; each panel has a 30x30 array of 1x1x20 mm3 LYSO scintillators with each end of the scintillator array optically connected to Silicon Photomultiplier (SiPM) arrays for depth-of-interaction (DOI) measurement. The trans-axial and axial field-of-view (FOV) are ~10 cm in diameter and 3.5 cm long. PCB and FPGA based detector readout and processing electronics has been developed. Preliminary system and imaging performances were evaluated with a Na-22 point source and a F-18 ultra-micro hot-rod phantom. The energy, DOI, and coincidence timing resolutions of the system are around 23%, 3.2 mm, and 4.88 ns, respectively. The measured system sensitivity is ~2.2% at the center of FOV, and the image resolution measured from the reconstructed point source images over the FOV ranges from 0.77 to 1.03 mm (mean 0.83 mm). Hot-rods with diameters from 1.0 to 2.4 mm are well separated on the reconstructed phantom image when DOI is applied.","PeriodicalId":6760,"journal":{"name":"2020 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC)","volume":"78 1","pages":"1-3"},"PeriodicalIF":0.0,"publicationDate":"2020-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83926574","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}

{"title":"Wireless Sensor Platform for Dry Spent Fuel Cask Monitoring","authors":"D. McAdams, Erik B. Johnson, M. Squillante, Andrew Harrington, R. Blakeley, E. Weststrate, Jane He, S. Bader, J. Christian","doi":"10.1109/NSS/MIC42677.2020.9508083","DOIUrl":"https://doi.org/10.1109/NSS/MIC42677.2020.9508083","url":null,"abstract":"Nuclear power plants regularly generate spent fuel that must be stored on the decade timescale. Often this is done in dry nuclear waste storage casks. Long-term monitoring would provide data that improves the safe maintenance of stored spent fuel. This requires measuring the conditions within waste casks using a self-contained sensor system. Radiation Monitoring Devices, Inc. is developing a system that detects damaged fuel rod cladding by sensing and quantifying the amount of 85Kr present using a diamond sensor. A potential means for power and data transfer through the cask wall uses an ultrasonic transmission method. The work described here advances the prototype toward inclusion in a specific model fuel cask, the NUHOMS® 32 PTH1 manufactured by Orano (formally, Areva Transnuclear, Inc.). The results include extensive radiological modeling studies, an estimation of the leaked activity due to 85Kr after a cladding breach (~ 1013Bq) derived from a literature review, a design for a prototype, and the characterization of a diamond detector at room temperature and in the presence of 85Kr.","PeriodicalId":6760,"journal":{"name":"2020 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC)","volume":"42 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2020-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82720682","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}

{"title":"Radioisotope Identification with Scintillation Detector Based on Artificial Neural Networks Using Simulated Training Data","authors":"Peng Fan, Siliang Feng, Chenglin Zhu, Chunqing Zhao, Y. Ding, Zicai Shen, Yaqiang Liu, Tianyu Ma, Y. Xia","doi":"10.1109/NSS/MIC42677.2020.9507888","DOIUrl":"https://doi.org/10.1109/NSS/MIC42677.2020.9507888","url":null,"abstract":"Artificial neural networks (ANN) based on learning the features of the entire measured gamma energy spectrum has been used for radioisotope identification and proved promising especially for gamma-ray spectroscopy with low energy resolution. The implementation of ANN method, however, requires tedious experimental measurement process in generation of training data for various radioisotopes. In this work, we propose an ANN-based radioisotope identification method with simulated training data. Gamma energy spectra of 27 different radioisotopes were generated with Monte Carlo simulation. A detector energy response model was proposed to match the energy spectra generated from simulation and measured from experiment, thus “pseudo” measured energy spectra of various radioisotopes transformed from simulation can be used for ANN training, which eliminates the tedious experimental measurement process for training data generation. To reduce the complexity of the training process, the principal component analysis (PCA) method was used for dimension reduction of the input energy spectra in ANN and the channel number of the energy spectra was reduced from 2000 to 50. The trained ANN was further used to identify experimentally measured gamma energy spectra of various radioisotopes including 60Co., 137CS., 18F, 131I, 226Ra and 232Th at 103, 104 and 105 count levels. In single isotope identification test, with increased count level, higher correct identification rate is achieved and at 105 count level, all the isotopes are correctly identified for all the samples. In mixed isotope identification test, at 105 count level, all the radioisotope combinations can be identified with a correct identification rate larger than 98%, which demonstrates the feasibility and accuracy of the ANN method. To conclude, the proposed ANN method with simulated training data features good radioisotope identification capability with greatly simplified training data generation process and is feasible for gamma spectroscopy with relatively poor energy resolution.","PeriodicalId":6760,"journal":{"name":"2020 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC)","volume":"29 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2020-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89107694","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}

{"title":"Spatial Registration of Neuroimaging Data: Analysis of the Convenience of Performing Non-Affine Transformations","authors":"F. Bayo, D. Castillo-Barnes, D. Salas-González, C. Jiménez-Mesa, J. Górriz, J. Ramírez, F. Segovia","doi":"10.1109/NSS/MIC42677.2020.9507925","DOIUrl":"https://doi.org/10.1109/NSS/MIC42677.2020.9507925","url":null,"abstract":"Computer-based analysis of neuroimaging data in multisubject studies requires a previous spatial registration procedure, which ensures that the same voxel across different images refers to the same anatomical position. Several algorithms have been proposed to this end and most of them perform the spatial registration in two steps, an affine transformation followed by a non-linear registration. While the former applies only translations, rotations, zoom and shears to the neuroimages, the non-linear registration step can deform them to adjust the size and shape of individual regions. Although the scientific community generally accepts that these transformations are necessary, even though they may introduce certain distortions (noise), some recent works indicate that it is preferable to perform the spatial registration as an affine transformation only, in order to prevent the non-linear registration from removing information that could be relevant in the further analysis. In this work we evaluated the influence of applying nonlinear transformations during the special registration of molecular neuroimages that will be used in computer systems intended to assist the diagnosis of neurodegenerative disorders. Specifically, we compared the performance of a Support Vector Machine classifier that used data spatially registered using only affine transformations and other one that used data that have been registered using the classical procedure, which includes non-linear transformations. Two datasets were considered, one intended to assist the diagnosis of Alzheimer's disease and other one intended to assist the diagnosis of Parkinsonism. The results suggest that non-linear transformations facilitate the subsequent classification and provide slightly higher accuracy rates. The different is more important with data in which the intensity is concentrated in a small target region such as DatSCAN neuroimages, used to assist the diagnosis of Parkinsonism.","PeriodicalId":6760,"journal":{"name":"2020 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC)","volume":"82 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2020-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90251996","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}