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Fonda UDS, Leitão ALA, Paiva MMDP, Willegaignon J, Josefsson A, Buchpiguel CA, Sapienza MT. Influence on voxel-based dosimetry: noise effect on absorbed dose dosimetry at single time-point versus sequential single-photon emission computed tomography. Nucl Med Commun 2023; 44:596-603. [PMID: 37068008 DOI: 10.1097/mnm.0000000000001697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/18/2023]
Abstract
OBJECTIVE The purpose of this study was to evaluate how statistical fluctuation in single-photon emission computed tomography (SPECT) images propagate to absorbed dose maps. METHODS SPECT/computed tomography (CT) images of iodine-131 filled phantoms, using different acquisition and processing protocols, were evaluated using STRATOS software to assess the absorbed dose distribution at the voxel level. Absorbed dose values and coefficient of variation (COV) were analyzed for dosimetry based on single time-point SPECT images and time-integrated activities of SPECT sequences with low and high counts. RESULTS Considering dosimetry based on a single time-point, the mean absorbed dose was not significantly affected by total counts or reconstruction parameters, but the uniformity of the absorbed dose maps had an almost linear correlation with SPECT noise. When high- and low-count SPECT sequences were used to generate an absorbed dose map, the absorbed dose COV for each of the temporal sequences was slightly lower than the absorbed dose COV based on the single SPECT image with the highest count included in the sequence. CONCLUSION The impact of changes in SPECT counts and reconstruction parameters is almost linear when dosimetry is based on isolated SPECT images, but less pronounced when dosimetry is based on sequential SPECTs.
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Affiliation(s)
- Uysha de S Fonda
- Departmento de Radiologia e Oncologia da Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo
| | | | | | | | - Anders Josefsson
- Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Carlos A Buchpiguel
- Departmento de Radiologia e Oncologia da Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo
| | - Marcelo T Sapienza
- Departmento de Radiologia e Oncologia da Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo
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Kubik A, Budzyńska A, Kacperski K, Maciak M, Kuć M, Piasecki P, Wiliński M, Konior M, Dziuk M, Iller E. Evaluation of qualitative and quantitative data of Y-90 imaging in SPECT/CT and PET/CT phantom studies. PLoS One 2021; 16:e0246848. [PMID: 33566845 PMCID: PMC7875374 DOI: 10.1371/journal.pone.0246848] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 01/26/2021] [Indexed: 01/06/2023] Open
Abstract
Introduction We aimed to assess the feasibility of SPECT and PET Y-90 imaging, and to compare these modalities by visualizing hot and cold foci in phantoms for varying isotope concentrations. Materials and methods The data was acquired from the Jaszczak and NEMA phantoms. In the Jaszczak phantom Y-90 concentrations of 0.1 MBq/ml and 0.2 MBq/ml were used, while higher concentrations, up to 1.0 MBq/ml, were simulated by acquisition time extension with respect to the standard clinical protocol of 30 sec/projection for SPECT and 30 min/bed position for PET imaging. For NEMA phantom, the hot foci had concentrations of about 4 MB/ml and the background 0.1 or 0.0 MBq/ml. All of the acquired data was analysed both qualitatively and quantitatively. Qualitative assessment was conducted by six observers asked to identify the number of visible cold or hot foci. Inter-observer agreement was assessed. Quantitative analysis included calculations of contrast and contrast-to-noise ratio (CNR), and comparisons with the qualitative results. Results For SPECT data up to two cold foci were discernible, while for PET four foci were visible. We have shown that CNR (with Rose criterion) is a good measure of foci visibility for both modalities. We also found good concordance of qualitative results for the Jaszczak phantom studies between the observers (corresponding Krippendorf’s alpha coefficients of 0.76 to 0.84). In the NEMA phantom without background activity all foci were visible in SPECT/CT images. With isotope in the background, 5 of 6 spheres were discernible (CNR of 3.0 for the smallest foci). For PET studies all hot spheres were visible, regardless of the background activity. Conclusions PET Y-90 imaging provided better results than Bremsstrahlung based SPECT imaging. This indicates that PET/CT might become the method of choice in Y-90 post radioembolization imaging for visualisation of both necrotic and hot lesions in the liver.
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Affiliation(s)
- Agata Kubik
- Department of Nuclear Medicine, Military Institute of Medicine, Warsaw, Poland
- * E-mail:
| | - Anna Budzyńska
- Department of Nuclear Medicine, Military Institute of Medicine, Warsaw, Poland
- Affidea Mazovian PET/CT Medical Centre, Warsaw, Poland
| | - Krzysztof Kacperski
- Department of Nuclear Medicine, Military Institute of Medicine, Warsaw, Poland
- Particle Acceleration Physics and Technology Division (TJ1), National Centre for Nuclear Research, Otwock—Świerk, Poland
| | - Maciej Maciak
- Radiological Metrology and Biomedical Physics Division (H2), National Centre for Nuclear Research, Otwock—Świerk, Poland
| | - Michał Kuć
- Radiological Metrology and Biomedical Physics Division (H2), National Centre for Nuclear Research, Otwock—Świerk, Poland
| | - Piotr Piasecki
- Department of Interventional Radiology, Military Institute of Medicine, Warsaw, Poland
| | - Maciej Wiliński
- Radiological Metrology and Biomedical Physics Division (H2), National Centre for Nuclear Research, Otwock—Świerk, Poland
| | - Marcin Konior
- National Centre for Nuclear Research, Radioisotope Centre POLATOM, Otwock—Świerk, Poland
| | - Mirosław Dziuk
- Department of Nuclear Medicine, Military Institute of Medicine, Warsaw, Poland
- Affidea Mazovian PET/CT Medical Centre, Warsaw, Poland
| | - Edward Iller
- National Centre for Nuclear Research, Radioisotope Centre POLATOM, Otwock—Świerk, Poland
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Tazegul TE, Polemi AM, Snyder A, Snyder C, Collins PG. Automated phantom analysis for gamma cameras and SPECT: A methodology for use in a clinical setting. J Appl Clin Med Phys 2020; 21:205-214. [PMID: 33142050 PMCID: PMC7700927 DOI: 10.1002/acm2.13057] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 09/09/2020] [Accepted: 09/22/2020] [Indexed: 01/16/2023] Open
Abstract
Purpose We introduce an automated, quantitative image analysis package for gamma camera and single photon emission computed tomography quality control. Our focus was to produce consistent methods that are feasible in clinical settings and use standard phantoms. Methods Four gamma cameras were used to acquire planar images of four‐quadrant bar phantoms and projection views of an American College of Radiology (ACR) phantom as part of a standard gamma camera quality control program. Images were sent to QC‐Track® (Atirix Medical Systems, Inc., Minneapolis, MN, USA), which automatically placed predetermined regions of interest (ROIs) and performed analysis. For the bar phantom, a standard deviation (SD)‐based modulation transfer function was calculated for a circular ROI in each quadrant. The bar widths at various MTF values were reported using linear interpolation as applicable. For the ACR phantom, the contrast‐to‐noise ratio (CNR) for each sphere, a modulation for each rods section, and a percent deviation for uniformity ROIs was calculated. Spheres corresponding to a CNR of 3, and the rod size at various modulations were also reported using linear interpolation. Visual analysis was performed by three medical physicists to evaluate interobserver variability and correlation to quantitative values. Results Analysis of the bar phantom showed predictable differences with changes in matrix size and bar width and showed consistency over similar acquisitions over the course of the study. Analysis of the ACR Phantom showed increasing CNR and modulation with increasing sphere and rod diameter, as expected. For both phantoms, quantitative values from linear interpolation correlated well with visual analysis. Conclusion Our automated method for quantitative image analysis is consistent and shows increased precision and sensitivity when compared to standard visual methods. Thresholds correspond well with visual analysis and previous guidelines for observer visibility (e.g., Rose criterion), making our framework suitable for routine use in a nuclear medicine department.
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Affiliation(s)
| | - Andrew M. Polemi
- Department of Radiology and Medical Imaging UVA Health Charlottesville VA USA
| | | | - Carl Snyder
- Atirix Medical Systems, Inc Minneapolis MN USA
| | - Patricia G. Collins
- Department of Radiology and Medical Imaging UVA Health Charlottesville VA USA
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Desmonts C, Bouthiba MA, Enilorac B, Nganoa C, Agostini D, Aide N. Evaluation of a new multipurpose whole-body CzT-based camera: comparison with a dual-head Anger camera and first clinical images. EJNMMI Phys 2020; 7:18. [PMID: 32185566 PMCID: PMC7078403 DOI: 10.1186/s40658-020-0284-5] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Accepted: 02/26/2020] [Indexed: 11/23/2022] Open
Abstract
Background Evaluate the physical performance of the VERITON CzT camera (Spectrum Dynamics, Caesarea, Israel) that benefits from new detection architecture enabling whole-body imaging compared to that of a conventional dual-head Anger camera. Methods Different line sources and phantom measurements were performed on each system to evaluate spatial resolution, sensitivity, energy resolution and image quality with acquisition and reconstruction parameters similar to those used in clinical routine. Extrinsic resolution was assessed using 99mTc capillary sources placed successively in air, in a head and in a body phantom filled with background activity. Spectral acquisitions for various radioelements used in nuclear medicine (99mTc, 123I, 201Tl, 111In) were performed to evaluate energy resolution by computing the FWHM of the measured photoelectric peak. Tomographic sensitivity was calculated by recording the total number of counts detected during tomographic acquisition for a set of source geometries representative of different clinical situations. Sensitivity was also evaluated in focus mode for the CzT camera, which consisted of forcing detectors to collect data in a reduced field-of-view. Image quality was assessed with a Jaszczak phantom filled with 350 MBq of 99mTc and scanned on each system with 30-,20-,10- and 5-min acquisition times. Results Extrinsic and tomographic resolution in the brain and body phantoms at the centre of the FOV was estimated at 3.55, 7.72 and 6.66 mm for the CzT system and 2.47, 7.75 and 7.72 mm for the conventional system, respectively. The energy resolution measured at 140 keV was 5.46% versus 9.21% for the Anger camera and was higher in a same manner for all energy peaks tested. Tomographic sensitivity for a point source in air was estimated at 236 counts·s−1·MBq−1 and increased to 1159 counts·s−1·MBq−1 using focus mode, which was 1.6 times and 8 times greater than the sensitivity measured on the scintillation camera (144 counts·s−1·MBq−1). Head and body measurements also showed higher sensitivity for the CzT camera in particular with focus mode. The Jaszczak phantom showed high image contrast uniformity and a high signal-to-noise ratio on the CzT system, even when decreasing acquisition time by 6-fold. Representative clinical cases are shown to illustrate these results. Conclusion The CzT camera has a superior sensitivity, higher energy resolution and better image contrast than the conventional SPECT camera, whereas spatial resolution remains similar. Introduction of this new technology may change current practices in nuclear medicine such as decreasing acquisition time and activity injected to patient.
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Affiliation(s)
- Cédric Desmonts
- Department of Nuclear Medicine, Caen University Hospital, Avenue de la côte de Nacre, 14033, Caen Cedex 9, France.
| | | | - Blandine Enilorac
- Department of Nuclear Medicine, Caen University Hospital, Avenue de la côte de Nacre, 14033, Caen Cedex 9, France
| | - Catherine Nganoa
- Department of Nuclear Medicine, Caen University Hospital, Avenue de la côte de Nacre, 14033, Caen Cedex 9, France
| | - Denis Agostini
- Department of Nuclear Medicine, Caen University Hospital, Avenue de la côte de Nacre, 14033, Caen Cedex 9, France.,Normandie University, Caen, France
| | - Nicolas Aide
- Department of Nuclear Medicine, Caen University Hospital, Avenue de la côte de Nacre, 14033, Caen Cedex 9, France.,Normandie University, Caen, France.,Inserm Anticipe, Normandie University, Caen, France
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Oumar AA, Erçelebi E. Assessment of an in-house phantom for the quality control of a clinical gamma camera. JOURNAL OF X-RAY SCIENCE AND TECHNOLOGY 2020; 28:461-470. [PMID: 32145008 DOI: 10.3233/xst-190610] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
OBJECTIVE Since in-house phantoms may provide effective quality control for gamma cameras in clinical settings, this study aims to assess an in-house phantom designed to perform quality control tests of a gamma camera using locally available, affordable materials. This is of particular importance in developing countries where scientific support may not be readily available. MATERIALS AND METHODS The phantom was made from cylindrical plexiglass with a diameter of 230 mm and thickness of 60 mm. The phantom design was based on NEMA recommendations and only used materials that are locally available and generally accessible to most nuclear medicine departments and require minimal engineering instruction. RESULTS The phantom demonstrated high levels of reliability and accuracy. The integral uniformity range was between 1.93% and 2.40%. The differential uniformity ranged between 1.48% and 1.70%. CONCLUSION This work demonstrates that in-house phantoms are capable of monitoring gamma camera performance. This approach is particularly useful when scientific support is not easily accessible and when commercial phantoms are not readily available.
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Affiliation(s)
- Alio Ahmat Oumar
- Department of Electrical and Electronics Engineering, University of Gaziantep, Gaziantep, Turkey
| | - Ergun Erçelebi
- Department of Electrical and Electronics Engineering, University of Gaziantep, Gaziantep, Turkey
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Velo P, Zakaria A. Determining Spatial Resolution of Gamma Cameras Using MATLAB. J Med Imaging Radiat Sci 2017; 48:39-42. [DOI: 10.1016/j.jmir.2016.10.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Revised: 09/22/2016] [Accepted: 10/17/2016] [Indexed: 10/20/2022]
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Saxena SK, Kumar Y, Malpani B, Rakshit S, Dash A. Development of a phantom and assessment of (141)Ce as a surrogate radionuclide for flood field uniformity testing of gamma cameras. Appl Radiat Isot 2016; 112:115-21. [PMID: 27031297 DOI: 10.1016/j.apradiso.2016.03.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 03/01/2016] [Accepted: 03/08/2016] [Indexed: 11/18/2022]
Abstract
This paper describes an indigenous method for development and deployment of rechargeable liquid filled phantom with newly proposed radionuclide (141)Ce for determination of extrinsic uniformity of gamma cameras. Details about design of phantom, neutron irradiation of cerium targets, chemical processing of (141)Ce, charging of phantom with (141)Ce solution and their performance evaluation are presented. Suitability of (141)Ce in quality assurance of gamma cameras used in in-vivo diagnostic imaging procedures has been amply demonstrated.
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Affiliation(s)
- Sanjay Kumar Saxena
- Isotope Production and Applications Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India.
| | - Yogendra Kumar
- Isotope Production and Applications Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India
| | - Basant Malpani
- Radiation Medicine Centre, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India
| | - Sutapa Rakshit
- Radiation Medicine Centre, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India
| | - Ashutosh Dash
- Isotope Production and Applications Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India
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Rana N, Rawat D, Parmar M, Dhawan DK, Bhati AK, Mittal BR. Evaluation of external beam hardening filters on image quality of computed tomography and single photon emission computed tomography/computed tomography. J Med Phys 2016; 40:198-206. [PMID: 26865755 PMCID: PMC4728890 DOI: 10.4103/0971-6203.170790] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
This study was undertaken to evaluate the effect of external metal filters on the image quality of computed tomography (CT) and single photon emission computed tomography (SPECT)/CT images. Images of Jaszack phantom filled with water and containing iodine contrast filled syringes were acquired using CT (120 kV, 2.5 mA) component of SPECT/CT system, ensuring fixation of filter on X-ray collimator. Different thickness of filters of Al and Cu (1 mm, 2 mm, 3 mm, and 4 mm) and filter combinations Cu 1 mm, Cu 2 mm, Cu 3 mm each in combination with Al (1 mm, 2 mm, 3 mm, and 4 mm), respectively, were used. All image sets were visually analyzed for streak artifacts and contrast to noise ratio (CNR) was derived. Similar acquisition was done using Philips CT quality control (QC) phantom and CNR were calculated for its lexan, perspex, and teflon inserts. Attenuation corrected SPECT/CT images of Jaszack phantom filled with 444-555 MBq (12-15 mCi) of (99m)Tc were obtained by applying attenuation correction map generated by hardened X-ray beam for different filter combination, on SPECT data. Uniformity, root mean square (rms) and contrast were calculated in all image sets. Less streak artifacts at iodine water interface were observed in images acquired using external filters as compared to those without a filter. CNR for syringes, spheres, and inserts of Philips CT QC phantom was almost similar to Al 2 mm, Al 3 mm, and without the use of filters. CNR decreased with increasing copper thickness and other filter combinations. Uniformity and rms were lower, and value of contrast was higher for SPECT/CT images when CT was acquired with Al 2 mm and 3 mm filter than for images acquired without a filter. The study suggests that for Infinia Hawkeye 4, SPECT/CT system, Al 2 mm, and 3 mm are the optimum filters for improving image quality of SPECT/CT images of Jaszack or Philips CT QC phantom keeping other parameters of CT constant.
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Affiliation(s)
- Nivedita Rana
- Department of Nuclear Medicine and PET, PGIMER, Chandigarh, India
| | - Dinesh Rawat
- Department of Nuclear Medicine and PET, PGIMER, Chandigarh, India
| | - Madan Parmar
- Department of Nuclear Medicine and PET, PGIMER, Chandigarh, India
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Buchert R, Kluge A, Tossici-Bolt L, Dickson J, Bronzel M, Lange C, Asenbaum S, Booij J, Atay Kapucu LÖ, Svarer C, Koulibaly PM, Nobili F, Pagani M, Sabri O, Sera T, Tatsch K, Vander Borght T, Van Laere K, Varrone A, Iida H. Reduction in camera-specific variability in [123I]FP-CIT SPECT outcome measures by image reconstruction optimized for multisite settings: impact on age-dependence of the specific binding ratio in the ENC-DAT database of healthy controls. Eur J Nucl Med Mol Imaging 2016; 43:1323-36. [DOI: 10.1007/s00259-016-3309-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 01/05/2016] [Indexed: 10/22/2022]
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Yamauchi M, Imabayashi E, Matsuda H, Nakagawara J, Takahashi M, Shimosegawa E, Hatazawa J, Suzuki M, Iwanaga H, Fukuda K, Iihara K, Iida H. Quantitative assessment of rest and acetazolamide CBF using quantitative SPECT reconstruction and sequential administration of (123)I-iodoamphetamine: comparison among data acquired at three institutions. Ann Nucl Med 2014; 28:836-50. [PMID: 25001261 PMCID: PMC4244544 DOI: 10.1007/s12149-014-0879-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Accepted: 06/29/2014] [Indexed: 10/27/2022]
Abstract
PURPOSE A recently developed technique which reconstructs quantitative images from original projection data acquired using existing single-photon emission computed tomography (SPECT) devices enabled quantitative assessment of cerebral blood flow (CBF) at rest and after acetazolamide challenge. This study was intended to generate a normal database and to investigate its inter-institutional consistency. METHODS The three institutions carried out a series of SPECT scanning on 32 healthy volunteers, following a recently proposed method that involved dual administration of (123)I-iodoamphetamine during a single SPECT scan. Intra-institute and inter-institutional variations of regional CBF values were evaluated both at rest and after acetazolamide challenge. Functional images were pooled for both rest and acetazolamide CBF, and inter-institutional difference was evaluated among these images using two independent software programs. RESULTS Quantitative assessment of CBF images at rest and after acetazolamide was successfully achieved with the given protocol in all institutions. Intra-institutional variation of CBF values at rest and after acetazolamide was consistent with previously reported values. Quantitative CBF values showed no significant difference among institutions in all regions, except for a posterior cerebral artery region after acetazolamide challenge in one institution which employed SPECT device with lowest spatial resolution. Pooled CBF images at rest and after acetazolamide generated using two software programs showed no institutional differences after equalization of the spatial resolution. CONCLUSIONS SPECT can provide reproducible images from projection data acquired using different SPECT devices. A common database acquired at different institutions may be shared among institutions, if images are reconstructed using a quantitative reconstruction program, and acquired by following a standardized protocol.
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Affiliation(s)
- Miho Yamauchi
- Department of Investigative Radiology, National Cerebral and Cardiovascular Center Research Institute, 5-7-1 Fujishiro-dai, Suita, Osaka 565-8565 Japan
| | - Etsuko Imabayashi
- Department of Nuclear Medicine, Saitama Medical University, 1397-1 Yamane, Hidaka, Saitama 350-1298 Japan
- Present Address: Integrative Brain Imaging Center, National Center of Neurology and Psychiatry, 4-1-1 Ogawa-Higashi, Kodaira, Tokyo 187-8551 Japan
| | - Hiroshi Matsuda
- Department of Nuclear Medicine, Saitama Medical University, 1397-1 Yamane, Hidaka, Saitama 350-1298 Japan
- Present Address: Integrative Brain Imaging Center, National Center of Neurology and Psychiatry, 4-1-1 Ogawa-Higashi, Kodaira, Tokyo 187-8551 Japan
| | - Jyoji Nakagawara
- Nakamura Memorial Hospital, 2 Kawazoe, Minami, Sapporo, Hokkaido 005-0802 Japan
- Present Address: Department of Neurosurgery, Integrative Stroke Imaging Center, National Cerebral and Cardiovascular Center Hospital, 5-7-1 Fujishiro-dai, Suita, Osaka 565-8565 Japan
| | - Masaaki Takahashi
- Nakamura Memorial Hospital, 2 Kawazoe, Minami, Sapporo, Hokkaido 005-0802 Japan
| | - Eku Shimosegawa
- Department of Nuclear Medicine, Osaka University School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871 Japan
| | - Jun Hatazawa
- Department of Nuclear Medicine, Osaka University School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871 Japan
| | - Michiyasu Suzuki
- Department of Neurosurgery, Yamaguchi University School of Medicine, 1-1-1 Minami-Kogushi, Ube, Yamaguchi 755-8505 Japan
| | - Hideyuki Iwanaga
- Department of Radiological Technology, Yamaguchi University Hospital, 1-1-1 Minami-Kogushi, Ube, Yamaguchi 755-8505 Japan
| | - Kenji Fukuda
- Department of Neurosurgery, National Cerebral and Cardiovascular Center Hospital, 5-7-1 Fujishiro-dai, Suita, Osaka 565-8565 Japan
- Present Address: Department of Neurosurgery, Fukuoka University School of Medicine, Fukuoka, Kyushu 814-0180 Japan
| | - Koji Iihara
- Department of Neurosurgery, National Cerebral and Cardiovascular Center Hospital, 5-7-1 Fujishiro-dai, Suita, Osaka 565-8565 Japan
- Present Address: Department of Neurosurgery, Kyushu University School of Medicine, Fukuoka, Kyushu 812-8582 Japan
| | - Hidehiro Iida
- Department of Investigative Radiology, National Cerebral and Cardiovascular Center Research Institute, 5-7-1 Fujishiro-dai, Suita, Osaka 565-8565 Japan
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Sensakovic WF, Hough MC, Kimbley EA. ACR testing of a dedicated head SPECT unit. J Appl Clin Med Phys 2014; 15:4632. [PMID: 25207395 PMCID: PMC5875529 DOI: 10.1120/jacmp.v15i4.4632] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Revised: 03/11/2014] [Accepted: 03/04/2014] [Indexed: 11/23/2022] Open
Abstract
Physics testing necessary for program accreditation is rigorously defined by the ACR. This testing is easily applied to most conventional SPECT systems based on gamma camera technology. The inSPira HD is a dedicated head SPECT system based on a rotating dual clamshell design that acquires data in a dual-spiral geometry. The unique geometry and configuration force alterations of the standard ACR physics testing protocol. Various tests, such as intrinsic planar uniformity and/or resolution, do not apply. The Data Spectrum Deluxe Phantom used for conventional SPECT testing cannot fit in the inSPira HD scanner bore, making (currently) unapproved use of the Small Deluxe SPECT Phantom necessary. Matrix size, collimator type, scanning time, reconstruction method, and attenuation correction were all varied from the typically prescribed ACR instructions. Visible spheres, sphere contrast, visible rod groups, uniformity, and root mean square (RMS) noise were measured. The acquired SPECT images surpassed the minimum ACR requirements for both spatial resolution (9.5 mm spheres resolved) and contrast (6.4 mm rod groups resolved). Sphere contrast was generally high. Integral uniformity was 4% and RMS noise was 1.7%. Noise appeared more correlated than in images from a conventional SPECT scanner. Attenuation-corrected images produced from direct CT scanning of the phantom and a manufacturer supplied model of the phantom demonstrated negligible differences.
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Iida H, Hori Y, Ishida K, Imabayashi E, Matsuda H, Takahashi M, Maruno H, Yamamoto A, Koshino K, Enmi J, Iguchi S, Moriguchi T, Kawashima H, Zeniya T. Three-dimensional brain phantom containing bone and grey matter structures with a realistic head contour. Ann Nucl Med 2012; 27:25-36. [PMID: 23011903 PMCID: PMC3549246 DOI: 10.1007/s12149-012-0655-7] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Accepted: 09/09/2012] [Indexed: 11/18/2022]
Abstract
Introduction A physical 3-dimensional phantom that simulates PET/SPECT images of static regional cerebral blood flow in grey matter with a realistic head contour has been developed. This study examined the feasibility of using this phantom for evaluating PET/SPECT images. Methods The phantom was constructed using a transparent, hydrophobic photo-curable polymer with a laser-modelling technique. The phantom was designed to contain the grey matter, the skull, and the trachea spaces filled with a radioactive solution, a bone-equivalent solution of K2HPO4, and air, respectively. The grey matter and bone compartments were designed to establish the connectivity. A series of experiments was performed to confirm the accuracy and reproducibility of the phantom using X-ray CT, SPECT, and PET. Results The total weight was 1997 ± 2 g excluding the inner liquid, and volumes were 563 ± 1 and 306 ± 2 mL, corresponding to the grey matter and bone compartments, respectively. The apparent attenuation coefficient averaged over the whole brain was 0.168 ± 0.006 cm−1 for Tc-99 m, which was consistent with the previously reported value for humans (0.168 ± 0.010 cm−1). Air bubbles were well removed from both grey-matter and bone compartments, as confirmed by X-ray CT. The phantom was well adapted to experiments using PET and SPECT devices. Conclusion The 3-dimensional brain phantom constructed in this study may be of use for evaluating the adequacy of SPECT/PET reconstruction software programs.
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Affiliation(s)
- Hidehiro Iida
- Department of Investigative Radiology, National Cerebral and Cardiovascular Center Research Institute, Suita City, Osaka, Japan.
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Kappadath SC. Effects of voxel size and iterative reconstruction parameters on the spatial resolution of 99mTc SPECT/CT. J Appl Clin Med Phys 2011; 12:3459. [PMID: 22089002 PMCID: PMC3978183 DOI: 10.1120/jacmp.v12i4.3459] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2010] [Revised: 05/09/2011] [Accepted: 05/23/2011] [Indexed: 12/03/2022] Open
Abstract
The purpose of this study was to evaluate the effects of voxel size and iterative reconstruction parameters on the radial and tangential resolution for 99mTc SPECT as a function of radial distance from isocenter. SPECT/CT scans of eight coplanar point sources of size smaller than 1 mm3 containing high concentration 99mTc solution were acquired on a SPECT/CT system with 5/8 inch NaI(Tl) detector and low‐energy, high‐resolution collimator. The tomographic projection images were acquired in step‐and‐shoot mode for 360 views over 360° with 250,000 counts per view, a zoom of 2.67, and an image matrix of 256×256 pixels that resulted in a 0.9×0.9×0.9 mm3 SPECT voxel size over 230 mm field‐of‐view. The projection images were also rebinned to image matrices of 128 × 128 and 64 × 64 to yield SPECT voxel sizes of 1.8×1.8×1.8 and 3.6×3.6×3.6 mm3, respectively. The SPECT/CT datasets were reconstructed using the vendor‐supplied iterative reconstruction software that incorporated collimator‐specific resolution recovery, CT‐based attenuation correction, and dual‐energy window‐based scatter correction using different combinations of iterations and subsets. SPECT spatial resolution was estimated as the full width at half maximum of the radial and tangential profiles through the center of each point source in reconstructed SPECT images. Both radial and tangential resolution improved with higher iterations and subsets, and with smaller voxel sizes. Both radial and tangential resolution also improved with radial distance further away from isocenter. The magnitude of variation decreased for smaller voxel sizes and for higher number of iterations and subsets. Tangential resolution was found not to be equal to the radial resolution, and the nature of the anisotropy depended on the distribution of the radionuclide and on the reconstruction parameters used. The tangential resolution converged faster than the radial resolution, with higher iterations and subsets. SPECT resolution was isotropic and independent of radial distance when reconstructed using filtered back‐projection. SPECT spatial resolution and therefore quantification of SPECT uptake via partial‐volume correction in clinical images were found to depend on the nature of activity distribution within the SPECT field‐of‐view and on the specific choice of iterative reconstruction parameters. PACS number: 87.57.uh, 87.57.cf, 87.87.nf
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Affiliation(s)
- S Cheenu Kappadath
- Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.
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14
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Design and use of mini-phantoms for high resolution planar gamma cameras. Appl Radiat Isot 2010; 68:2448-51. [DOI: 10.1016/j.apradiso.2010.06.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2009] [Revised: 06/02/2010] [Accepted: 06/03/2010] [Indexed: 11/21/2022]
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15
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Iida H, Nakagawara J, Hayashida K, Fukushima K, Watabe H, Koshino K, Zeniya T, Eberl S. Multicenter evaluation of a standardized protocol for rest and acetazolamide cerebral blood flow assessment using a quantitative SPECT reconstruction program and split-dose 123I-iodoamphetamine. J Nucl Med 2010; 51:1624-31. [PMID: 20847163 DOI: 10.2967/jnumed.110.078352] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
UNLABELLED SPECT can provide valuable diagnostic and treatment response information in large-scale multicenter clinical trials. However, SPECT has been limited in providing consistent quantitative functional parametric values across the centers, largely because of a lack of standardized procedures to correct for attenuation and scatter. Recently, a novel software package has been developed to reconstruct quantitative SPECT images and assess cerebral blood flow (CBF) at rest and after acetazolamide challenge from a single SPECT session. This study was aimed at validating this technique at different institutions with a variety of SPECT devices and imaging protocols. METHODS Twelve participating institutions obtained a series of SPECT scans on physical phantoms and clinical patients. The phantom experiments included the assessment of septal penetration for each collimator used and of the accuracy of the reconstructed images. Clinical studies were divided into 3 protocols, including intrainstitutional reproducibility, a comparison with PET, and rest-rest study consistency. The results from 46 successful studies were analyzed. RESULTS Activity concentration estimation (Bq/mL) in the reconstructed SPECT images of a uniform cylindric phantom showed an interinstitution variation of ±5.1%, with a systematic underestimation of concentration by 12.5%. CBF values were reproducible both at rest and after acetazolamide on the basis of repeated studies in the same patient (mean ± SD difference, -0.4 ± 5.2 mL/min/100 g, n = 44). CBF values were also consistent with those determined using PET (-6.1 ± 5.1 mL/min/100 g, n = 6). CONCLUSION This study demonstrates that SPECT can quantitatively provide physiologic functional images of rest and acetazolamide challenge CBF, using a quantitative reconstruction software package.
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Affiliation(s)
- Hidehiro Iida
- Dual-Table Autoradiography SPECT Research Group in Japan, Osaka, Japan.
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16
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Ng AH, Ng KH, Dharmendra H, Perkins AC. A low-cost phantom for simple routine testing of single photon emission computed tomography (SPECT) cameras. Appl Radiat Isot 2009; 67:1864-8. [PMID: 19049851 DOI: 10.1016/j.apradiso.2008.10.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2008] [Revised: 09/02/2008] [Accepted: 10/21/2008] [Indexed: 11/25/2022]
Abstract
A simple sphere test phantom has been developed for routine performance testing of SPECT systems in situations where expensive commercial phantoms may not be available. The phantom was based on a design with six universal syringe hubs set in the frame to support a circular array of six glass blown spheres of different sizes. The frame was then placed into a water-filled CT abdomen phantom and scanned with a triple head camera system (Philips IRIX, USA). Comparison was made with a commercially available phantom (Deluxe Jaszczak phantom). Whereas the commercial phantom demonstrates cold spot resolution, an important advantage of the sphere test phantom was that hot spot resolution could be easily measured using almost half (370MBq) of the activity recommended for use in the commercial phantom. Results showed that the contrast increased non-linearly with sphere volume and radionuclide concentration. The phantom was found to be suitable as an inexpensive option for daily performance tests.
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Affiliation(s)
- A H Ng
- Department of Biomedical Imaging, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
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17
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Kappadath SC, Erwin WD, Wendt RE. A novel method to evaluate gamma camera rotational uniformity and sensitivity variation. Med Phys 2009; 36:1947-55. [DOI: 10.1118/1.3125642] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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18
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Zanzonico P. Routine quality control of clinical nuclear medicine instrumentation: a brief review. J Nucl Med 2008; 49:1114-31. [PMID: 18587088 DOI: 10.2967/jnumed.107.050203] [Citation(s) in RCA: 116] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
This article reviews routine quality-control (QC) procedures for current nuclear medicine instrumentation, including the survey meter, dose calibrator, well counter, intraoperative probe, organ ("thyroid") uptake probe, gamma-camera, SPECT and SPECT/CT scanner, and PET and PET/CT scanner. It should be particularly useful for residents, fellows, and other trainees in nuclear medicine, nuclear cardiology, and radiology. The procedures described and their respective frequencies are presented only as general guidelines.
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Affiliation(s)
- Pat Zanzonico
- Departments of Medical Physics and Radiology, Memorial Sloan-Kettering Cancer Center, New York, New York 10021, USA.
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Kappadath SC, Erwin WD, Wendt RE. Observed inter-camera variability of clinically relevant performance characteristics for Siemens Symbia gamma cameras. J Appl Clin Med Phys 2006; 7:74-80. [PMID: 17533358 PMCID: PMC5722386 DOI: 10.1120/jacmp.v7i4.2376] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2006] [Revised: 10/16/2006] [Accepted: 12/31/1969] [Indexed: 11/23/2022] Open
Abstract
We conducted an evaluation of the intercamera (i.e., between cameras) variability in clinically relevant performance characteristics for Symbia gamma cameras (Siemens Medical Solutions, Malvern, PA) based on measurements made using nine separate systems. The significance of the observed intercamera variability was determined by comparing it to the intracamera (i.e., within a single camera) variability. Measurements of performance characteristics were based on the standards of the National Electrical Manufacturers Association and reports 6, 9, 22, and 52 from the American Association of Physicists in Medicine. All measurements were performed using 99mTc (except 57Co used for extrinsic resolution) and low-energy, high-resolution collimation. Of the nine cameras, four have crystals 3/8 in. thick and five have crystals 5/8 in. thick. We evaluated intrinsic energy resolution, intrinsic and extrinsic spatial resolution, intrinsic integral and differential flood uniformity over the useful field-of-view, count rate at 20% count loss, planar sensitivity, single-photon emission computed tomography (SPECT) resolution, and SPECT integral uniformity. The intracamera variability was estimated by repeated measurements of the performance characteristics on a single system. The significance of the observed intercamera variability was evaluated using the two-tailed F distribution. The planar sensitivity of the gamma cameras tested was found be variable at the 99.8% confidence level for both the 3/8-in. and 5/8-in. crystal systems. The integral uniformity and energy resolution were found to be variable only for the 5/8-in. crystal systems at the 98% and 90% confidence level, respectively. All other performance characteristics tested exhibited no significant variability between camera systems. The measured variability reported here could perhaps be used to define nominal performance values of Symbia gamma cameras for planar and SPECT imaging.
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Affiliation(s)
- S Cheenu Kappadath
- The University of Texas M.D. Anderson Cancer Center, Department of Imaging Physics, Houston, Texas 77030, USA.
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20
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Brzymialkiewicz CN, Tornai MP, McKinley RL, Cutler SJ, Bowsher JE. Performance of dedicated emission mammotomography for various breast shapes and sizes. Phys Med Biol 2006; 51:5051-64. [PMID: 16985287 PMCID: PMC3261231 DOI: 10.1088/0031-9155/51/19/021] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We evaluate the effect of breast shape and size and lesion location on a dedicated emission mammotomography system developed in our lab. The hemispherical positioning gantry allows ample flexibility in sampling a pendant, uncompressed breast. Realistic anthropomorphic torso (which includes the upper portion of the arm) and breast phantoms draw attention to the necessity of using unique camera trajectories (orbits) rather than simple circular camera trajectories. We have implemented several novel three-dimensional (3D) orbits with fully contoured radius-of-rotation capability for compensating for the positioning demands that emerge from different breast shapes and sizes. While a general orbit design may remain the same between two different breasts, the absolute polar tilt range and radius-of-rotation range may vary. We have demonstrated that using 3D orbits with increased polar camera tilt, lesions near the chest wall can be visualized for both large and small sized breasts (325 ml to 1,060 ml), for a range of intrinsic contrasts (three to ten times higher activity concentration in the lesion than breast background). Overall, nearly complete 3D acquisition schemes yield image data with relatively high lesion SNRs and contrasts and with minimal distortion of the uncompressed breast shape.
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Affiliation(s)
- C N Brzymialkiewicz
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA
- Department of Radiology, Duke University Medical Center, Durham, NC 27710, USA
| | - M P Tornai
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA
- Department of Radiology, Duke University Medical Center, Durham, NC 27710, USA
| | - R L McKinley
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA
- Department of Radiology, Duke University Medical Center, Durham, NC 27710, USA
| | - S J Cutler
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA
- Department of Radiology, Duke University Medical Center, Durham, NC 27710, USA
| | - J E Bowsher
- Department of Radiology, Duke University Medical Center, Durham, NC 27710, USA
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21
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Jarritt PH, Whalley DR, Skrypniuk JV, Houston AS, Fleming JS, Cosgriff PS. UK audit of single photon emission computed tomography reconstruction software using software generated phantoms. Nucl Med Commun 2002; 23:483-91. [PMID: 11973490 DOI: 10.1097/00006231-200205000-00009] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The purpose of this study was to undertake an audit of the quantitative characteristics of single photon emission computed tomography software using projection data from an analytically generated software phantom and a measured line source. The phantom consisted of three structures. A uniformly filled cylinder, a series of cylindrical rods of various diameters in a background activity with a rod to background ratio of 2:1 and lastly, a set of three concentric rings of activity in the ratio 1:0:1. The phantom contained no added statistical noise. No attenuation was imposed on the data. The phantom was generated analytically and projections were distributed at six different count densities. A single set of projections from a thin line source was also distributed. These data were distributed to centres throughout the UK. Centres were asked to reconstruct the data using a 'ramp only' reconstruction with no additional smoothing function applied. Data were requested for mean and standard deviation in the uniform cylinder, the maximum counts for each cylindrical rod and the mean counts in regions placed within the concentric rings. For the measured line source, centres were asked to measure the full width at half maximum and peak pixel counts for a profile through the reconstructed line. Results from 115 systems were obtained from 100 centres throughout the UK. These provided data from 12 software providers, 11 of these being commercial companies. Data were compared with the known input values and histograms of the distribution of results obtained. Significant differences in quantitative parameters were noted for the different input count densities as well as between suppliers and revisions of software from single suppliers.
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MESH Headings
- Computer Simulation
- Data Collection
- Equipment Failure Analysis/methods
- Equipment Failure Analysis/standards
- Humans
- Image Processing, Computer-Assisted/instrumentation
- Image Processing, Computer-Assisted/methods
- Image Processing, Computer-Assisted/standards
- Phantoms, Imaging/standards
- Quality Assurance, Health Care/methods
- Quality Control
- Reproducibility of Results
- Sensitivity and Specificity
- Societies, Scientific
- Software Validation
- Tomography, Emission-Computed, Single-Photon/instrumentation
- Tomography, Emission-Computed, Single-Photon/methods
- Tomography, Emission-Computed, Single-Photon/standards
- Tomography, Emission-Computed, Single-Photon/statistics & numerical data
- United Kingdom
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Affiliation(s)
- P H Jarritt
- IPEM Nuclear Medicine Software Working Party, York, UK.
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22
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SPECT issues. Clin Nucl Med 1998. [DOI: 10.1007/978-1-4899-3356-0_53] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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23
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Abstract
Field uniformity is an important parameter for monitoring the performance of SPECT imaging systems. However, it is difficult to apply objective measures of uniformity because of the large variance associated with reconstructed images. In the proposed method, annular sampling of the SPECT uniformity image is used to reduce the noise level without decreasing the magnitude of uniformity artifacts. The reconstructed uniformity image is sectioned into annular rings centered on the center of rotation to match the expected distribution of uniformity artifacts. Statistical fluctuations are reduced by averaging the counts within the annular rings, allowing the use of objective measures of field uniformity such as integral uniformity. Application of the annular sampling technique on simulated and phantom uniformity images showed that the technique could reliably quantify SPECT uniformity artifacts at acceptable count levels. As a result this method can be used to objectively evaluate SPECT field uniformity in systems which utilize parallel collimation and circular orbits.
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Affiliation(s)
- M T Madsen
- University of Iowa, Department of Radiology, Iowa City 52242, USA.
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24
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Affiliation(s)
- I G Zubal
- Department of Diagnostic Radiology, Yale University School of Medicine, New Haven, Conn., USA.
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