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Zannoni EM, Sankar P, Jin Y, Liu C, Sinusas AJ, Metzler SD, Meng LJ. Design and development of the DE-SPECT system: a clinical SPECT system for broadband multi-isotope imaging of peripheral vascular disease. Phys Med Biol 2024; 69:125016. [PMID: 38815617 PMCID: PMC11167601 DOI: 10.1088/1361-6560/ad5266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 05/05/2024] [Accepted: 05/30/2024] [Indexed: 06/01/2024]
Abstract
Objective. Peripheral Vascular Disease (PVD) affects more than 230 million people worldwide and is one of the leading causes of disability among people over age 60. Nowadays, PVD remains largely underdiagnosed and undertreated, and requires the development of tailored diagnostic approaches. We present the full design of the Dynamic Extremity SPECT (DE-SPECT) system, the first organ-dedicated SPECT system for lower extremity imaging, based on 1 cm thick Cadmium Zinc Telluride (CZT) spectrometers and a dynamic dual field-of-view (FOV) synthetic compound-eye (SCE) collimator.Approach. The proposed DE-SPECT detection system consists of 48 1 cm thick 3D-position-sensitive CZT spectrometers arranged in a partial ring of 59 cm in diameter in a checkerboard pattern. The detection system is coupled with a compact dynamic SCE collimator that allows the user to select between two different FOVs at any time during an imaging study: a wide-FOV (28 cm diameter) configuration for dual-leg or scout imaging or a high-resolution and high-sensitivity (HR-HS) FOV (16 cm diameter) for single-leg or focused imaging.Main results.The preliminary experimental data show that the CZT spectrometer achieves a 3D intrinsic spatial resolution of <0.75 mm FWHM and an excellent energy resolution over a broad energy range (2.6 keV FWHM at 218, 3.3 keV at 440 keV). From simulations, the wide-FOV configuration offers a 0.034% averaged sensitivity at 140 keV and <8 mm spatial resolution, whereas the HR-HS configuration presents a peak central sensitivity of 0.07% at 140 keV and a ∼5 mm spatial resolution. The dynamic SCE collimator enables the capability to perform joint reconstructions that would ensure an overall improvement in imaging performance.Significance. The DE-SPECT system is a stationary and high-performance SPECT system that offers an excellent spectroscopic performance with a unique computer-controlled dual-FOV imaging capability, and a relatively high sensitivity for multi-tracer and multi-functional SPECT imaging of the extremities.
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Affiliation(s)
- E M Zannoni
- Department of Nuclear, Plasma, and Radiological Engineering, University of Illinois at Urbana Champaign, Urbana, IL, United States of America
| | - P Sankar
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States of America
| | - Y Jin
- Department of Nuclear, Plasma, and Radiological Engineering, University of Illinois at Urbana Champaign, Urbana, IL, United States of America
| | - C Liu
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT, United States of America
| | - A J Sinusas
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT, United States of America
- Department of Medicine, Yale University School of Medicine, New Haven, CT, United States of America
| | - S D Metzler
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, United States of America
| | - L J Meng
- Department of Nuclear, Plasma, and Radiological Engineering, University of Illinois at Urbana Champaign, Urbana, IL, United States of America
- Beckman Institute for Advance Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, United States of America
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Huang W, Mok GSP. Multi-pinhole collimator design in different numbers of projections for brain SPECT. Front Med (Lausanne) 2023; 10:1211726. [PMID: 37841005 PMCID: PMC10568733 DOI: 10.3389/fmed.2023.1211726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 08/31/2023] [Indexed: 10/17/2023] Open
Abstract
Purpose High resolution and sensitivity brain SPECT is promising for the accurate diagnosis of Alzheimer's disease (AD) and Parkinson's disease (PD). Multi-pinhole (MPH) collimators with a good performance in imaging small field-of-view (FOV) could be better used for brain SPECT. In this study, we aim to evaluate the impact of varying the number of pinholes and the number of projections on the performance of MPH brain SPECT. Methods The system design was based on a commercial clinical dual-head SPECT/CT scanner, with target spatial resolutions of 12 mm and 8 mm for AD and PD SPECT, respectively. In total, 1-25 pinholes were modeled for 64, 32, 16, 8, 4, and 2 projections. The 3D NURBS-based HUman Brain (NHUB) phantom was used in the analytical simulation to model 99mTc-HMPAO and 99mTc-TRODAT distributions. The 2D Derenzo hot-rod phantom and star phantom were used in Monte Carlo simulations to evaluate the spatial resolution and angular sampling performance of MPH. The influence of different detector positions was also evaluated for 2, 4, and 6 angular views. The projections were reconstructed using the 3D MPH ML-EM method. Normalized mean square error, coefficient of variation, and image profiles were evaluated. Results Along with the decrease in the number of projections, more pinholes are required to achieve the optimum performance. For 32 projections, 9- and 7-pinhole collimators provide the best normalized mean square error (NMSE) to the coefficient of variation (COV) trade-off for 99mTc-HMPAO and 99mTc-TRODAT, respectively. Detector positions substantially affect the image quality for MPH SPECT for 2 and 4 angular views. The smallest rod size for the Derenzo hot-rod phantom, which could be resolved, is 7.9 mm for the MPH general purpose collimator (MPGP) with more than 16 projections and 6.4 mm for MPH high-resolution collimator (MPHR) with more than 8 projections. Conclusion The number of pinholes affects the performance of the MPH collimator, especially when the projection views become fewer. More pinholes are required for fewer projections to provide better angular sampling in MPH for complex activity distributions. Detector positions affect the image quality of MPH SPECT for 2 and 4 angular views, where L-mode acquisition is slightly superior to H-mode. MPH collimators exhibited improved spatial resolution and angular sampling compared with both LEHR and single pinhole collimators.
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Affiliation(s)
- Wenbo Huang
- Biomedical Imaging Laboratory (BIG), Department of Electrical and Computer Engineering, Faculty of Science and Technology, University of Macau, Taipa, Macau SAR, China
| | - Greta S. P. Mok
- Biomedical Imaging Laboratory (BIG), Department of Electrical and Computer Engineering, Faculty of Science and Technology, University of Macau, Taipa, Macau SAR, China
- Center for Cognitive and Brain Sciences, Institute of Collaborative Innovation, University of Macau, Taipa, Macau SAR, China
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Zannoni EM, Yang C, Meng LJ. Design Study of an Ultrahigh Resolution Brain SPECT System Using a Synthetic Compound-Eye Camera Design With Micro-Slit and Micro-Ring Apertures. IEEE TRANSACTIONS ON MEDICAL IMAGING 2021; 40:3711-3727. [PMID: 34255626 PMCID: PMC8711775 DOI: 10.1109/tmi.2021.3096920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
In this paper, we discuss the design study for a brain SPECT imaging system, referred to as the HelmetSPECT system, based on a spherical synthetic compound-eye (SCE) gamma camera design. The design utilizes a large number ( ∼ 500 ) of semiconductor detector modules, each coupled to an aperture with a very narrow opening for high-resolution SPECT imaging applications. In this study, we demonstrate that this novel system design could provide an excellent spatial resolution, a very high sensitivity, and a rich angular sampling without scanning motion over a clinically relevant field-of-view (FOV). These properties make the proposed HelmetSPECT system attractive for dynamic imaging of epileptic patients during seizures. In ictal SPECT, there is typically no prior information on where the seizures would happen, and both the imaging resolution and quantitative accuracy of the dynamic SPECT images would provide critical information for staging the seizures outbreak and refining the plans for subsequent surgical intervention.We report the performance evaluation and comparison among similar system geometries using non-conventional apertures, such as micro-ring and micro-slit, and traditional lofthole apertures. We demonstrate that the combination of ultrahigh-resolution imaging detectors, the SCE gamma camera design, and the micro-ring and micro-slit apertures would offer an interesting approach for the future ultrahigh-resolution clinical SPECT imaging systems without sacrificing system sensitivity and FOV.
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Könik A, Zeraatkar N, Kalluri KS, Auer B, Fromme TJ, He Y, May M, Furenlid LR, Kuo PH, King MA. Improved Performance of a Multipinhole SPECT for DAT Imaging by Increasing Number of Pinholes at the Expense of Increased Multiplexing. IEEE TRANSACTIONS ON RADIATION AND PLASMA MEDICAL SCIENCES 2021; 5:817-825. [PMID: 34746540 DOI: 10.1109/trpms.2020.3035626] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
SPECT imaging of dopamine transporters (DAT) in the brain is a widely utilized study to improve the diagnosis of Parkinsonian syndromes, where conventional (parallel-hole and fan-beam) collimators on dual-head scanners are commonly employed. We have designed a multi-pinhole (MPH) collimator to improve the performance of DAT imaging. The MPH collimator focuses on the striatum and hence offers a better trade-off for sensitivity and spatial resolution than the conventional collimators within this clinically most relevant region for DAT imaging. Our original MPH design consisted of 9 pinholes with a background-to-striatal (Bkg/Str) projection multiplexing of 1% only. In this simulation study, we investigated whether further improvements in the performance of MPH imaging could be obtained by increasing the number of pinholes, hence by enhancing the sensitivity and sampling, despite the ambiguity in reconstructing images due to increased multiplexing. We performed analytic simulations of the MPH configurations with 9, 13, and 16 pinholes (aperture diameters: 4-6mm) using a digital phantom modeling DAT imaging. Our quantitative analyses indicated that using 13 (Bkg/Str: 12%) and 16 (Bkg/Str: 22%) pinholes provided better performance than the original 9-pinhole configuration for the acquisition with 2 or 4 angular views, but a similar performance with 8 and 16 views.
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Affiliation(s)
- Arda Könik
- Department of Imaging, Dana Farber Cancer Institute, Boston, MA, 02215, USA
| | - Navid Zeraatkar
- Department of Radiology, Univ. of Mass. Medical School, Worcester, MA, 01605, USA
| | - Kesava S Kalluri
- Department of Radiology, Univ. of Mass. Medical School, Worcester, MA, 01605, USA
| | - Benjamin Auer
- Department of Radiology, Univ. of Mass. Medical School, Worcester, MA, 01605, USA
| | | | - Yulun He
- MD Anderson Cancer Center, Houston, TX
| | - Micaehla May
- Department of Radiology, University of Arizona, Tucson, AZ, 85724 USA
| | - Lars R Furenlid
- Department of Radiology, University of Arizona, Tucson, AZ, 85724 USA
| | - Phillip H Kuo
- Department of Radiology, University of Arizona, Tucson, AZ, 85724 USA
| | - Michael A King
- Department of Radiology, Univ. of Mass. Medical School, Worcester, MA, 01605, USA
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Zeraatkar N, Kalluri KS, Auer B, May M, Richards RG, Furenlid LR, Kuo PH, King MA. Cerebral SPECT imaging with different acquisition schemes using varying levels of multiplexing versus sensitivity in an adaptive multi-pinhole brain-dedicated scanner. Biomed Phys Eng Express 2021; 7. [PMID: 34507309 DOI: 10.1088/2057-1976/ac25c3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 09/10/2021] [Indexed: 11/12/2022]
Abstract
Application of multi-pinhole collimator in pinhole-based SPECT increases detection sensitivity. The presence of multiplexing in projection images due to the usage of multiple pinholes can further improve the sensitivity at the cost of adding data ambiguity. We are developing a next-generation adaptive brain-dedicated SPECT system -AdaptiSPECT-C. The AdaptiSPECT-C can adapt the multiplexing level and system sensitivity using adaptable pinhole modules. In this study, we investigated the performance of 4 data acquisition schemes with different multiplexing levels and sensitivities on cerebral SPECT imaging. Schemes #1, #2, and #3 have <1%, 67%, and 31% overall multiplexing, respectively, while the 4th scheme without multiplexing is considered as ground truth. The ground-truth and schemes #1-3 have 1.0, 1.7, 5.1, and 4.0 times higher sensitivity, respectively, compared to a dual-headed parallel-hole SPECT system at matched spatial resolution. A customized XCAT brain perfusion digital phantom emulating the distribution of I-123 N-isopropyl iodoamphetamine (IMP) in a 99th percentile size male was used for simulations. Data acquisition for each scheme was performed at two count levels (low-count and high-count relative to the recommended clinical count level). The normalized root-mean-square error (NRMSE) for schemes #1, #2, and #3 with the low-count (high-count) scenario showed 11%, 4%, and 5% (10%, 5%, and 6%) deviation, respectively, from that of the multiplex-free ground truth. For both the low-count and high-count scenarios, scheme #1 resulted in the least accurate activity ratio (AR) for almost all the analyzed gray-matter brain regions. Further schemes #2 or #3 led to the most accurate AR values with both low-count and high-count scenarios for all the analyzed gray-matter regions. It was thus observed that even with this large head size which leads to significant multiplexing levels, the higher sensitivity from multiplexing could to some extent mitigate the data ambiguity and be translated into reconstructed images of higher quality.
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Affiliation(s)
- Navid Zeraatkar
- Department of Radiology, University of Massachusetts Medical School, Worcester, MA, United States of America.,Siemens Medical Solutions USA, Inc., Knoxville, TN, United States of America
| | - Kesava S Kalluri
- Department of Radiology, University of Massachusetts Medical School, Worcester, MA, United States of America
| | - Benjamin Auer
- Department of Radiology, University of Massachusetts Medical School, Worcester, MA, United States of America
| | - Micaehla May
- James C. Wyant College of Optical Sciences, University of Arizona, Tucson, AZ, United States of America
| | - R Garrett Richards
- James C. Wyant College of Optical Sciences, University of Arizona, Tucson, AZ, United States of America
| | - Lars R Furenlid
- James C. Wyant College of Optical Sciences, University of Arizona, Tucson, AZ, United States of America.,Department of Medical Imaging, University of Arizona, Tucson, AZ, United States of America
| | - Phillip H Kuo
- Department of Medical Imaging, University of Arizona, Tucson, AZ, United States of America
| | - Michael A King
- Department of Radiology, University of Massachusetts Medical School, Worcester, MA, United States of America
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Zeraatkar N, Auer B, Kalluri KS, May M, Momsen NC, Richards RG, Furenlid LR, Kuo PH, King MA. Improvement in sampling and modulation of multiplexing with temporal shuttering of adaptable apertures in a brain-dedicated multi-pinhole SPECT system. Phys Med Biol 2021; 66:065004. [PMID: 33352545 PMCID: PMC9893699 DOI: 10.1088/1361-6560/abd5cd] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
We are developing a multi-detector pinhole-based stationary brain-dedicated SPECT system: AdaptiSPECT-C. In this work, we introduced a new design prototype with multiple adaptable pinhole apertures for each detector to modulate the multiplexing by employing temporal shuttering of apertures. Temporal shuttering of apertures over the scan time provides the AdaptiSPECT-C with the capability of multiple-frame acquisition. We investigated, through analytic simulation, the impact of projection multiplexing on image quality using several digital phantoms and a customized anthropomorphic phantom emulating brain perfusion clinical distribution. The 105 pinholes in the collimator of the system were categorized into central, axial, and lateral apertures. We generated, through simulation, collimators of different multiplexing levels. Several data acquisition schemes were also created by changing the imaging time share of the acquisition frames. Sensitivity increased by 35% compared to the single-pinhole-per-detector base configuration of the AdaptiSPECT-C when using the central, axial, and lateral apertures with equal acquisition time shares within a triple-frame scheme with a high multiplexing scenario. Axial and angular sampling of the base configuration was enhanced by adding the axial and lateral apertures. We showed that the temporal shuttering of apertures can be exploited, trading the sensitivity, to modulate the multiplexing and to acquire a set of non-multiplexed non-truncated projections. Our results suggested that reconstruction benefited from utilizing both non-multiplexed projections and projections with modulated multiplexing resulting in a noticeably reduction in the multiplexing-induced image artefacts. Contrast recovery factor improved by 20% (9%) compared to the base configuration for a Defrise (hot-rod) phantom study when the central and axial (lateral) apertures with equal time shares were combined. The results revealed that, as an overall trend at each simulated multiplexing level, lowest normalized root-mean-square errors for the brain gray-matter regions were achieved with the combined usage of the central apertures and axial/lateral apertures.
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Affiliation(s)
- Navid Zeraatkar
- Department of Biomedical Engineering, University of California Davis, Davis, CA, USA, 95616.,Department of Radiology, University of Massachusetts Medical School, Worcester, MA, USA, 01655
| | - Benjamin Auer
- Department of Radiology, University of Massachusetts Medical School, Worcester, MA, USA, 01655
| | - Kesava S. Kalluri
- Department of Radiology, University of Massachusetts Medical School, Worcester, MA, USA, 01655
| | - Micaehla May
- James C. Wyant College of Optical Sciences, University of Arizona, Tucson, AZ, USA, 85721
| | - Neil C. Momsen
- James C. Wyant College of Optical Sciences, University of Arizona, Tucson, AZ, USA, 85721
| | - R. Garrett Richards
- James C. Wyant College of Optical Sciences, University of Arizona, Tucson, AZ, USA, 85721
| | - Lars R. Furenlid
- James C. Wyant College of Optical Sciences, University of Arizona, Tucson, AZ, USA, 85721.,Department of Medical Imaging, University of Arizona, Tucson, AZ, USA, 85724
| | - Phillip H. Kuo
- Department of Medical Imaging, University of Arizona, Tucson, AZ, USA, 85724
| | - Michael A. King
- Department of Radiology, University of Massachusetts Medical School, Worcester, MA, USA, 01655
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Auer B, Zeraatkar N, Goding JC, Könik A, Fromme TJ, Kalluri KS, Furenlid LR, Kuo PH, King MA. Inclusion of quasi-vertex views in a brain-dedicated multi-pinhole SPECT system for improved imaging performance. Phys Med Biol 2021; 66:035007. [PMID: 33065564 PMCID: PMC9899040 DOI: 10.1088/1361-6560/abc22e] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
With brain-dedicated multi-detector systems employing pinhole apertures the usage of detectors facing the top of the patient's head (i.e. quasi-vertex (QV) views) can provide the advantage of additional viewing from close to the brain for improved detector coverage. In this paper, we report the results of simulation and reconstruction studies to investigate the impact of the QV views on the imaging performance of AdaptiSPECT-C, a brain-dedicated stationary SPECT system under development. In this design, both primary and scatter photons from regions located inferior to the brain can contribute to SPECT projections acquired by the QV views, and thus degrade AdaptiSPECT-C imaging performance. In this work, we determined the proportion, origin, and nature (i.e. primary, scatter, and multiple-scatter) of counts emitted from structures within the head and throughout the body contributing to projections from the different AdaptiSPECT-C detector rings, as well as from a true vertex view detector. We simulated phantoms used to assess different aspects of image quality (i.e. uniform activity concentration sphere, and Derenzo), as well as anthropomorphic phantoms with different count levels emulating clinical 123I activity distributions (i.e. DaTscan and perfusion). We determined that attenuation and scatter in the patient's body greatly diminish the probability of the photons emitted outside the volume of interest reaching to detectors and being recorded within the 15% photopeak energy window. In addition, we demonstrated that the inclusion of the residual of such counts in the system acquisition does not degrade visual interpretation or quantitative analysis. The addition of the QV detectors improves volumetric sensitivity, angular sampling, and spatial resolution leading to significant enhancement in image quality, especially in the striato-thalamic and superior regions of the brain. Besides, the use of QV detectors improves the recovery of clinically relevant metrics such as the striatal binding ratio and mean activity in selected cerebral structures. Our findings proving the usefulness of the QV ring for brain imaging with 123I agents can be generalized to other commonly used SPECT imaging agents labelled with isotopes, such as 99mTc and likely 111In.
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Affiliation(s)
- Benjamin Auer
- Department of Radiology, University of Massachusetts Medical School, Worcester, MA, USA, 01655
| | - Navid Zeraatkar
- Department of Radiology, University of Massachusetts Medical School, Worcester, MA, USA, 01655
| | - Justin C. Goding
- Department of Radiology, University of Massachusetts Medical School, Worcester, MA, USA, 01655
| | - Arda Könik
- Department of Imaging, Dana Farber Cancer Institute, Boston, MA, USA, 02215
| | | | - Kesava S. Kalluri
- Department of Radiology, University of Massachusetts Medical School, Worcester, MA, USA, 01655
| | - Lars R. Furenlid
- Wyant College of Optical Sciences, University of Arizona, Tucson, AZ, USA, 85721.,Department of Medical Imaging, University of Arizona, Tucson, AZ, USA, 85724
| | - Phillip H. Kuo
- Department of Medical Imaging, University of Arizona, Tucson, AZ, USA, 85724
| | - Michael A. King
- Department of Radiology, University of Massachusetts Medical School, Worcester, MA, USA, 01655
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Ozsahin I, Chen L, Könik A, King MA, Beekman FJ, Mok GSP. The clinical utilities of multi-pinhole single photon emission computed tomography. Quant Imaging Med Surg 2020; 10:2006-2029. [PMID: 33014732 PMCID: PMC7495312 DOI: 10.21037/qims-19-1036] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 07/30/2020] [Indexed: 11/06/2022]
Abstract
Single photon emission computed tomography (SPECT) is an important imaging modality for various applications in nuclear medicine. The use of multi-pinhole (MPH) collimators can provide superior resolution-sensitivity trade-off when imaging small field-of-view compared to conventional parallel-hole and fan-beam collimators. Besides the very successful application in small animal imaging, there has been a resurgence of the use of MPH collimators for clinical cardiac and brain studies, as well as other small field-of-view applications. This article reviews the basic principles of MPH collimators and introduces currently available and proposed clinical MPH SPECT systems.
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Affiliation(s)
- Ilker Ozsahin
- Biomedical Imaging Laboratory, Department of Electrical and Computer Engineering, Faculty of Science and Technology, University of Macau, Macau, China
- Department of Biomedical Engineering, Faculty of Engineering, Near East University, Nicosia/TRNC, Mersin-10, Turkey
- DESAM Institute, Near East University, Nicosia/TRNC, Mersin-10, Turkey
| | - Ling Chen
- Biomedical Imaging Laboratory, Department of Electrical and Computer Engineering, Faculty of Science and Technology, University of Macau, Macau, China
| | - Arda Könik
- Department of Imaging, Dana Farber Cancer Institute, Boston, MA, USA
| | - Michael A. King
- Department of Radiology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Freek J. Beekman
- Section of Biomedical Imaging, Department of Radiation Science and Technology, Delft University of Technology, Mekelweg 15, 2629 JB Delft, The Netherlands
- MILabs B.V, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, The Netherlands
| | - Greta S. P. Mok
- Biomedical Imaging Laboratory, Department of Electrical and Computer Engineering, Faculty of Science and Technology, University of Macau, Macau, China
- Center for Cognitive and Brain Sciences, Institute of Collaborative Innovation, University of Macau, Macau, China
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Chen Y, Goorden MC, Vastenhouw B, Beekman FJ. Optimized sampling for high resolution multi-pinhole brain SPECT with stationary detectors. ACTA ACUST UNITED AC 2020; 65:015002. [DOI: 10.1088/1361-6560/ab5bc6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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10
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Chen Y, Vastenhouw B, Wu C, Goorden MC, Beekman FJ. Optimized image acquisition for dopamine transporter imaging with ultra-high resolution clinical pinhole SPECT. ACTA ACUST UNITED AC 2018; 63:225002. [DOI: 10.1088/1361-6560/aae76c] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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Könik A, De Beenhouwer J, Mukherjee JM, Kalluri K, Banerjee S, Zeraatkar N, Fromme T, King MA. Simulations of a Multi-Pinhole SPECT Collimator for Clinical Dopamine Transporter (DAT) Imaging. IEEE TRANSACTIONS ON RADIATION AND PLASMA MEDICAL SCIENCES 2018; 2:444-451. [PMID: 31011693 PMCID: PMC6474676 DOI: 10.1109/trpms.2018.2831208] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
SPECT imaging of the dopamine transporter (DAT) is used for diagnosis and monitoring progression of Parkinson's Disease (PD), and differentiation of PD from other neurological disorders. The diagnosis is based on the DAT binding in the caudate and putamen structures in the striatum. We previously proposed a relatively inexpensive method to improve the detection and quantification of these structures for dual-head SPECT by replacing one of the fan-beam collimators with a specially designed multi-pinhole (MPH) collimator. In this work, we developed a realistic model of the proposed MPH system using the GATE simulation package and verified the geometry with an analytic simulator. Point source projections from these simulations closely matched confirming the accuracy of the pinhole geometries. The reconstruction of a hot-rod phantom showed that 4.8 mm resolution is achievable. The reconstructions of the XCAT brain phantom showed clear separation of the putamen and caudate, which is expected to improve the quantification of DAT imaging and PD diagnosis. Using this GATE model, point spread functions modeling physical factors will be generated for use in reconstruction. Also, further improvements in geometry are being investigated to increase the sensitivity of this base system while maintaining a target spatial resolution of 4.5-5 mm.
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Affiliation(s)
- Arda Könik
- Department of Radiology, UMass Medical School, Worcester, MA, USA
| | | | | | - Kesava Kalluri
- Department of Radiology, UMass Medical School, Worcester, MA, USA
| | | | - Navid Zeraatkar
- Department of Radiology, UMass Medical School, Worcester, MA, USA
| | | | - Michael A King
- Department of Radiology, UMass Medical School, Worcester, MA, USA
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Gonzalez AJ, Sanchez F, Benlloch JM. Organ-Dedicated Molecular Imaging Systems. IEEE TRANSACTIONS ON RADIATION AND PLASMA MEDICAL SCIENCES 2018. [DOI: 10.1109/trpms.2018.2846745] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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13
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Chen L, Tsui BMW, Mok GSP. Design and evaluation of two multi-pinhole collimators for brain SPECT. Ann Nucl Med 2017; 31:636-648. [DOI: 10.1007/s12149-017-1195-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 07/07/2017] [Indexed: 11/29/2022]
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Hutton BF, Occhipinti M, Kuehne A, Máthé D, Kovács N, Waiczies H, Erlandsson K, Salvado D, Carminati M, Montagnani GL, Short SC, Ottobrini L, van Mullekom P, Piemonte C, Bukki T, Nyitrai Z, Papp Z, Nagy K, Niendorf T, de Francesco I, Fiorini C. Development of clinical simultaneous SPECT/MRI. Br J Radiol 2017; 91:20160690. [PMID: 28008775 PMCID: PMC5966197 DOI: 10.1259/bjr.20160690] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
There is increasing clinical use of combined positron emission tomography and MRI, but to date there has been no clinical system developed capable of simultaneous single-photon emission computed tomography (SPECT) and MRI. There has been development of preclinical systems, but there are several challenges faced by researchers who are developing a clinical prototype including the need for the system to be compact and stationary with MRI-compatible components. The limited work in this area is described with specific reference to the Integrated SPECT/MRI for Enhanced stratification in Radio-chemo Therapy (INSERT) project, which is at an advanced stage of developing a clinical prototype. Issues of SPECT/MRI compatibility are outlined and the clinical appeal of such a system is discussed, especially in the management of brain tumour treatment.
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Affiliation(s)
- Brian F Hutton
- 1 Institute of Nuclear Medicine, University College London (UCL), London, UK
| | - Michele Occhipinti
- 2 Dipartimento di Elettronica Informazione e Bioingegneria, Politecnico di Milano and Instituto Nacionale di Fisica Nucleare (INFN), Milan, Italy
| | | | - Domokos Máthé
- 4 CROmed Ltd, Budapest, Hungary.,5 Department of Biophysics and Radiation Biology, Semmelweis University, Budapest, Hungary
| | | | | | - Kjell Erlandsson
- 1 Institute of Nuclear Medicine, University College London (UCL), London, UK
| | - Debora Salvado
- 1 Institute of Nuclear Medicine, University College London (UCL), London, UK
| | - Marco Carminati
- 2 Dipartimento di Elettronica Informazione e Bioingegneria, Politecnico di Milano and Instituto Nacionale di Fisica Nucleare (INFN), Milan, Italy
| | - Giovanni L Montagnani
- 2 Dipartimento di Elettronica Informazione e Bioingegneria, Politecnico di Milano and Instituto Nacionale di Fisica Nucleare (INFN), Milan, Italy
| | - Susan C Short
- 6 Faculty of Medicine and Health, University of Leeds, Leeds, UK
| | - Luisa Ottobrini
- 7 Department of Medical-Surgical Pathophysiology and Transplants, University of Milan, Italy.,8 Institute for Molecular Bioimaging and Physiology (IBFM), National Council of Research (CNR), Milan, Italy
| | | | | | | | | | | | | | | | - Irene de Francesco
- 12 Department of Oncology, University College London Hospitals NHS Foundation Trust, London
| | - Carlo Fiorini
- 2 Dipartimento di Elettronica Informazione e Bioingegneria, Politecnico di Milano and Instituto Nacionale di Fisica Nucleare (INFN), Milan, Italy
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15
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Bae S, Chun J, Cha H, Yeom JY, Lee K, Lee H. Simulation study of a novel target oriented SPECT design using a variable pinhole collimator. Med Phys 2016; 44:470-478. [PMID: 28032904 DOI: 10.1002/mp.12075] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Revised: 10/08/2016] [Accepted: 12/19/2016] [Indexed: 11/05/2022] Open
Abstract
PURPOSE In the past decade, demands for organ specific (target oriented) single-photon emission computed tomography (SPECT) is increasing, and several groups have conducted studies on developing clinical dedicated SPECT with pinhole collimator to improve the spatial resolution. However, acceptance angle of the collimator cannot be adjusted to fit the different ROIs of target objects because the shape of pinhole could not be changed, and the magnifying factor cannot be maximized as the collimator-to-detector distance is fixed. Furthermore, those dedicated pinhole SPECTs are typically made for a single purpose and therefore possess a drawback in that it cannot be utilized for any other purpose. In this study, we propose a novel SPECT system using variable pinhole collimator (VP SPECT) whose parameters are flexible. METHODS The proposed variable pinhole collimator is modeled on conventional pinhole by piling several tungsten layers of different apertures. Depending on the combination of the holes in each layer, a variety of hole diameters and acceptance angles of the pinhole can be made. In addition, VP SPECT system allows attaching the collimator to the object as close as possible to maximize the sensitivity and adjust the distance of the pinhole from the scintillation detector to optimize the system resolution for each rotation angle, automatically. For quantitative measurement, we compared the sensitivity and spatial resolution of VP SPECT with those of conventional pinhole SPECT. To determine the possibility of the clinical and preclinical use of proposed system, a digital mouse whole-body (MOBY) phantom is used for simulating the live mouse model. RESULTS The result of simulation using ultra-micro hot spot phantom shows that the sensitivity of the proposed VP SPECT system is about 297% of that of the conventional system. While hot rods of diameter 0.6 mm can be distinguished in the image with the proposed VP SPECT system, 1.2-mm hot rods are barely discernible in the conventional pinhole SPECT image. According to the result of MOBY phantom simulation, heart walls separated by 3 mm were not distinguished in conventional pinhole SPECT images, but were clearly discerned in VP SPECT images. CONCLUSIONS In this study, we designed a novel pinhole collimator for SPECT and presented preliminary results of target oriented imaging with a simulation study. Currently, we are pursuing strategies to realize the proposed system, with the goal to apply the technology into a high-sensitivity and high-resolution preclinical SPECT. Should VP SPECT be applied to the clinical setting, we anticipate a high-sensitivity, high-resolution system for applications such as heart dedicated SPECT or related fields.
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Affiliation(s)
- Seungbin Bae
- Bio-convergence Engineering, College of Health Science, Korea University, Seoul, 02841, Republic of Korea
| | - Jaehee Chun
- Bio-convergence Engineering, College of Health Science, Korea University, Seoul, 02841, Republic of Korea
| | - Hyemi Cha
- Bio-convergence Engineering, College of Health Science, Korea University, Seoul, 02841, Republic of Korea
| | - Jung Yeol Yeom
- Bio-convergence Engineering, College of Health Science, Korea University, Seoul, 02841, Republic of Korea.,School of Biomedical Engineering, College of Health Science, Korea University, Seoul, 02841, Republic of Korea
| | - Kisung Lee
- Bio-convergence Engineering, College of Health Science, Korea University, Seoul, 02841, Republic of Korea.,School of Biomedical Engineering, College of Health Science, Korea University, Seoul, 02841, Republic of Korea
| | - Hakjae Lee
- Research Institute of Global Health Tech., College of Health Science, Korea University, Seoul, 02841, Republic of Korea
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16
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King MA, Mukherjee JM, Könik A, Zubal IG, Dey J, Licho R. Design of a Multi-Pinhole Collimator for I-123 DaTscan Imaging on Dual-Headed SPECT Systems in Combination with a Fan-Beam Collimator. IEEE TRANSACTIONS ON NUCLEAR SCIENCE 2016; 63:90-97. [PMID: 27182078 PMCID: PMC4864598 DOI: 10.1109/tns.2016.2515519] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
For the 2011 FDA approved Parkinson's Disease (PD) SPECT imaging agent I-123 labeled DaTscan, the volume of interest (VOI) is the interior portion of the brain. However imaging of the occipital lobe is also required with PD for calculation of the striatal binding ratio (SBR), a parameter of significance in early diagnosis, differentiation of PD from other disorders with similar clinical presentations, and monitoring progression. Thus we propose the usage of a combination of a multi-pinhole (MPH) collimator on one head of the SPECT system and a fan-beam on the other. The MPH would be designed to provide high resolution and sensitivity for imaging of the interior portion of the brain. The fan-beam collimator would provide lower resolution but complete sampling of the brain addressing data sufficiency and allowing a volume-of-interest to be defined over the occipital lobe for calculation of SBR's. Herein we focus on the design of the MPH component of the combined system. Combined reconstruction will be addressed in a subsequent publication. An analysis of 46 clinical DaTscan studies was performed to provide information to define the VOI, and design of a MPH collimator to image this VOI. The system spatial resolution for the MPH was set to 4.7 mm, which is comparable to that of clinical PET systems, and significantly smaller than that of fan-beam collimators employed in SPECT. With this set, we compared system sensitivities for three aperture array designs, and selected the 3 × 3 array due to it being the highest of the three. The combined sensitivity of the apertures for it was similar to that of an ultra-high resolution fan-beam (LEUHRF) collimator, but smaller than that of a high-resolution fan-beam collimator (LEHRF). On the basis of these results we propose the further exploration of this design through simulations, and the development of combined MPH and fan-beam reconstruction.
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Affiliation(s)
- Michael A. King
- Department of Radiology, University of Massachusetts Medical School Worcester, MA 01655 USA
| | - Joyeeta M Mukherjee
- Department of Radiology, University of Massachusetts Medical School Worcester, MA 01655 USA
| | - Arda Könik
- Department of Radiology, University of Massachusetts Medical School Worcester, MA 01655 USA
| | | | - Joyoni Dey
- Department of Physics & Astronomy, Louisiana State University, LA
| | - Robert Licho
- Department of Radiology, UMassMemorial Healthcare, Worcester, MA 01655 USA
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17
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Van Audenhaege K, Van Holen R, Vandenberghe S, Vanhove C, Metzler SD, Moore SC. Review of SPECT collimator selection, optimization, and fabrication for clinical and preclinical imaging. Med Phys 2015; 42:4796-813. [PMID: 26233207 PMCID: PMC5148182 DOI: 10.1118/1.4927061] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Revised: 07/07/2015] [Accepted: 07/08/2015] [Indexed: 01/23/2023] Open
Abstract
In single photon emission computed tomography, the choice of the collimator has a major impact on the sensitivity and resolution of the system. Traditional parallel-hole and fan-beam collimators used in clinical practice, for example, have a relatively poor sensitivity and subcentimeter spatial resolution, while in small-animal imaging, pinhole collimators are used to obtain submillimeter resolution and multiple pinholes are often combined to increase sensitivity. This paper reviews methods for production, sensitivity maximization, and task-based optimization of collimation for both clinical and preclinical imaging applications. New opportunities for improved collimation are now arising primarily because of (i) new collimator-production techniques and (ii) detectors with improved intrinsic spatial resolution that have recently become available. These new technologies are expected to impact the design of collimators in the future. The authors also discuss concepts like septal penetration, high-resolution applications, multiplexing, sampling completeness, and adaptive systems, and the authors conclude with an example of an optimization study for a parallel-hole, fan-beam, cone-beam, and multiple-pinhole collimator for different applications.
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Affiliation(s)
- Karen Van Audenhaege
- Department of Electronics and Information Systems, MEDISIP-IBiTech, Ghent University-iMinds Medical IT, De Pintelaan 185 block B/5, Ghent B-9000, Belgium
| | - Roel Van Holen
- Department of Electronics and Information Systems, MEDISIP-IBiTech, Ghent University-iMinds Medical IT, De Pintelaan 185 block B/5, Ghent B-9000, Belgium
| | - Stefaan Vandenberghe
- Department of Electronics and Information Systems, MEDISIP-IBiTech, Ghent University-iMinds Medical IT, De Pintelaan 185 block B/5, Ghent B-9000, Belgium
| | - Christian Vanhove
- Department of Electronics and Information Systems, MEDISIP-IBiTech, Ghent University-iMinds Medical IT, De Pintelaan 185 block B/5, Ghent B-9000, Belgium
| | - Scott D Metzler
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Stephen C Moore
- Division of Nuclear Medicine, Department of Radiology, Brigham and Women's Hospital and Harvard Medical School, 75 Francis Street, Boston, Massachusetts 02115
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18
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Van Audenhaege K, Vanhove C, Vandenberghe S, Van Holen R. The evaluation of data completeness and image quality in multiplexing multi-pinhole SPECT. IEEE TRANSACTIONS ON MEDICAL IMAGING 2015; 34:474-486. [PMID: 25291791 DOI: 10.1109/tmi.2014.2361051] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Multi-pinhole collimators are often used in pre-clinical SPECT systems because they have a better resolution-sensitivity tradeoff than parallel hole collimators when imaging small objects. Most multi-pinhole collimators are designed to allow no or only a limited amount of overlap between the different pinhole projections because the ambiguity introduced by multiplexing pinholes can result in artifacts. The origin of these artifacts is still not fully understood, but previous research has already shown that data incompleteness could be part of the explanation. Therefore, we developed a method to investigate data completeness in multiplexing multi-pinhole systems and showed that a certain activity distribution can be successfully reconstructed when the nonmultiplexed data is complete or when the overlap can be sufficiently de-multiplexed. We validated this method using computer simulated phantom data of different multiplexing systems. We also studied contrast-to-noise and nonprewhitening matched filter signal-to-noise ratio (NPW-SNR) to compare the image quality in a single pinhole system with multiplexing systems. We found that our method can indeed be used to evaluate data completeness in multiplexing systems and found no artifacts in the systems that had complete data. Sensitivity increased significantly with multiplexing but we found only small, nonsignificant differences in contrast-to-noise ratio. However, the NPW-SNR did slightly improve in the multiplexing setups. We conclude that more multiplexing does not necessarily result in more artifacts and that even a high amount of multiplexing can still result in artifact-free images if the nonmultiplexed data is complete or when the overlap can be sufficiently de-multiplexed.
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19
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Islamian JP, Azazrm A, Mahmoudian B, Gharapapagh E. Advances in pinhole and multi-pinhole collimators for single photon emission computed tomography imaging. World J Nucl Med 2015; 14:3-9. [PMID: 25709537 PMCID: PMC4337004 DOI: 10.4103/1450-1147.150505] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
The collimator in single photon emission computed tomography (SPECT), is an important part of the imaging chain. One of the most important collimators that used in research, preclinical study, small animal, and organ imaging is the pinhole collimator. Pinhole collimator can improve the tradeoff between sensitivity and resolution in comparison with conventional parallel-hole collimator and facilities diagnosis. However, a major problem with pinhole collimator is a small field of view (FOV). Multi-pinhole collimator has been investigated in order to increase the sensitivity and FOV with a preserved spatial resolution. The geometry of pinhole and multi-pinhole collimators is a critical factor in the image quality and plays a key role in SPECT imaging. The issue of the material and geometry for pinhole and multi-pinhole collimators have been a controversial and much disputed subject within the field of SPECT imaging. On the other hand, recent developments in collimator optimization have heightened the need for appropriate reconstruction algorithms for pinhole SPECT imaging. Therefore, iterative reconstruction algorithms were introduced to minimize the undesirable effect on image quality. Current researches have focused on geometry and configuration of pinhole and multi-pinhole collimation rather than reconstruction algorithm. The lofthole and multi-lofthole collimator are samples of novel designs. The purpose of this paper is to provide a review on recent researches in the pinhole and multi-pinhole collimators for SPECT imaging.
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Affiliation(s)
- Jalil Pirayesh Islamian
- Department of Medical Physics, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - AhmadReza Azazrm
- Department of Medical Physics, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Babak Mahmoudian
- Department of Radiology, Faculty of Medicine, Unit of Nuclear Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Esmail Gharapapagh
- Department of Radiology, Faculty of Medicine, Unit of Nuclear Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
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20
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Simulation study on a stationary data acquisition SPECT system with multi-pinhole collimators attached to a triple-head gamma camera system. Ann Nucl Med 2014; 28:716-24. [DOI: 10.1007/s12149-014-0865-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2014] [Accepted: 05/21/2014] [Indexed: 10/25/2022]
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