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https://www.readbyqxmd.com/read/29783644/a-model-for-remote-depth-estimation-of-buried-radioactive-wastes-using-cdznte-detector
#1
Ikechukwu Kevin Ukaegbu, Kelum A A Gamage
This paper presents the results of an attenuation model for remote depth estimation of buried radioactive wastes using a Cadmium Zinc Telluride (CZT) detector. Previous research using an organic liquid scintillator detector system showed that the model is able to estimate the depth of a 329-kBq Cs-137 radioactive source buried up to 12 cm in sand with an average count rate of 100 cps. The results presented in this paper showed that the use of the CZT detector extended the maximum detectable depth of the same radioactive source to 18 cm in sand with a significantly lower average count rate of 14 cps...
May 18, 2018: Sensors
https://www.readbyqxmd.com/read/29599399/molecular-breast-imaging-administered-activity-does-not-require-adjustment-based-on-patient-size
#2
Thuy D Tran, Lacey R Ellingson, Tiffinee N Swanson, Courtney M Solberg, Michael K O'Connor, Carrie B Hruska
Objective: At our institution, MBI is performed with 300 MBq Tc-99m sstamibi for all patients. For some nuclear medicine procedures, administered activity or imaging time is increased for patients of larger size in order to obtain adequate counts. Our objective was to assess whether uptake of Tc-99m sestamibi in the breast is influenced by patient size. Methods: Records from patients who underwent a clinical MBI examination between July - November 2016 were reviewed. Those in whom our standard injection and preparation techniques were followed were included in the analysis [3,4]...
March 29, 2018: Journal of Nuclear Medicine Technology
https://www.readbyqxmd.com/read/29597105/experimental-and-simulation-research-on-the-screening-effect-of-the-pixelated-czt-imaging-detector
#3
Miao Li, Gangqiang Zha, Benjie Zhou, Yuedong Ma, Shali Xiao, Mingkun Zhao, Keyu Ding, Shousen Zhou
Massive efforts have been made to investigate the characteristics of the CdZnTe detector under different extreme conditions. In this paper, we experimented with different radiation sources to investigate the imaging screening effect of the pixelated CdZnTe detector under ultrahigh irradiance. A donut-shaped irradiation image was obtained due to the increase in the X-ray tube current or the tube voltage. Moreover, statistical data revealed that the total count of all pixels was not significantly different, while the event-count of irradiated area pixels decreased significantly...
March 21, 2018: Applied Radiation and Isotopes
https://www.readbyqxmd.com/read/29546490/real-time-gated-spect-myocardial-perfusion-imaging-with-czt-detectors-a-promising-tool-for-monitoring-left-ventricular-function
#4
EDITORIAL
Roberta Assante, Alberto Cuocolo
No abstract text is available yet for this article.
March 15, 2018: Journal of Nuclear Cardiology: Official Publication of the American Society of Nuclear Cardiology
https://www.readbyqxmd.com/read/29536291/feasibility-study-of-a-novel-general-purpose-czt-based-digital-spect-camera-initial-clinical-results
#5
Elinor Goshen, Leonid Beilin, Eli Stern, Tal Kenig, Ronen Goldkorn, Simona Ben-Haim
BACKGROUND: The performance of a prototype novel digital single-photon emission computed tomography (SPECT) camera with multiple pixelated CZT detectors and high sensitivity collimators (Digital SPECT; Valiance X12 prototype, Molecular Dynamics) was evaluated in various clinical settings. Images obtained in the prototype system were compared to images from an analog camera fitted with high-resolution collimators. Clinical feasibility, image quality, and diagnostic performance of the prototype were evaluated in 36 SPECT studies in 35 patients including bone (n = 21), brain (n = 5), lung perfusion (n = 3), and parathyroid (n = 3) and one study each of sentinel node and labeled white blood cells...
March 14, 2018: EJNMMI Physics
https://www.readbyqxmd.com/read/29520004/mechanical-dyssynchrony-and-diastolic-dysfunction-are-common-in-lvh-a-pilot-correlation-study-using-doppler-echocardiography-and-czt-gated-spect-mpi
#6
Szu-Ying Tsai, Shan-Ying Wang, Yu-Chien Shiau, Yen-Wen Wu
Hypertrophic cardiomyopathy (HCM) is an often under-diagnosed cause of left ventricular hypertrophy (LVH). It affects 1/500 of the population, is the most commonly inherited cardiovascular disorder, and can present in apical, concentric, or septal forms. Although most patients are asymptomatic, sudden cardiac death can be the initial presentation of HCM. By retrospectively enrolling patients suspected of having three different types of HCM in the absence of epicardial coronary stenosis, we aimed to examine systolic and diastolic dysfunction and perfusion abnormalities using both Doppler echocardiography and state-of-the-art gated single-photon emission computerized tomography (SPECT) myocardial perfusion imaging (MPI) with a cadmium-zinc-telluride camera and thallium-201...
March 8, 2018: Scientific Reports
https://www.readbyqxmd.com/read/29511930/dual-isotope-stress-tl-201-and-rest-tc-99m-czt-spect-are-we-truly-leveraging-czt-technology
#7
EDITORIAL
Saurabh Malhotra, Rami Doukky
No abstract text is available yet for this article.
March 6, 2018: Journal of Nuclear Cardiology: Official Publication of the American Society of Nuclear Cardiology
https://www.readbyqxmd.com/read/29497801/first-validation-of-myocardial-flow-reserve-assessed-by-dynamic-99m-tc-sestamibi-czt-spect-camera-head-to-head-comparison-with-15-o-water-pet-and-fractional-flow-reserve-in-patients-with-suspected-coronary-artery-disease-the-waterday-study
#8
Denis Agostini, Vincent Roule, Catherine Nganoa, Nathaniel Roth, Raphael Baavour, Jean-Jacques Parienti, Farzin Beygui, Alain Manrique
PURPOSE: We assessed the feasibility of myocardial blood flow (MBF) and flow reserve (MFR) estimation using dynamic SPECT with a novel CZT camera in patients with stable CAD, in comparison with 15 O-water PET and fractional flow reserve (FFR). METHODS: Thirty patients were prospectively included and underwent FFR measurements in the main coronary arteries (LAD, LCx, RCA). A stenosis ≥50% was considered obstructive and a FFR abnormal if ≤0.8. All patients underwent a dynamic rest/stress 99m Tc-sestamibi CZT-SPECT and 15 O-water PET for MBF and MFR calculation...
March 1, 2018: European Journal of Nuclear Medicine and Molecular Imaging
https://www.readbyqxmd.com/read/29418004/spectral-resolution-and-high-flux-capability-tradeoffs-in-cdte-detectors-for-clinical-ct
#9
Scott S Hsieh, Paurakh L Rajbhandary, Norbert J Pelc
PURPOSE: Photon-counting detectors using CdTe or CZT substrates are promising candidates for future CT systems but suffer from a number of nonidealities, including charge sharing and pulse pileup. By increasing the pixel size of the detector, the system can improve charge sharing characteristics at the expense of increasing pileup. The purpose of this work is to describe these considerations in the optimization of the detector pixel pitch. METHODS: The transport of x rays through the CdTe substrate was simulated in a Monte Carlo fashion using GEANT4...
April 2018: Medical Physics
https://www.readbyqxmd.com/read/29340989/gated-spect-myocardial-perfusion-imaging-with-cadmium-zinc-telluride-detectors-allows-real-time-assessment-of-dobutamine-stress-induced-wall-motion-abnormalities
#10
Rene Nkoulou, Mathias Wolfrum, Aju P Pazhenkottil, Michael Fiechter, Ronny R Buechel, Oliver Gaemperli, Philipp A Kaufmann
BACKGROUND: Left ventricular (LV) ejection fraction (EF) during high dobutamine stress (HD) by real-time gated-SPECT myocardial perfusion imaging (MPI) on a cadmium-zinc-telluride (CZT) gamma camera was validated versus cardiac magnetic resonance imaging (CMR). METHODS AND RESULTS: After injecting 99mTc-tetrofosmin (320 MBq) in 50 patients (mean age 64 +/- 11 years), EF at rest and post-stress as well as relevant changes in EF at HD (ΔEF ≥ 5%) were assessed. CZT and CMR rest EF values yielded an excellent correlation and agreement (r = 0...
January 16, 2018: Journal of Nuclear Cardiology: Official Publication of the American Society of Nuclear Cardiology
https://www.readbyqxmd.com/read/29327252/compared-vulnerabilities-to-small-cardiac-motions-between-different-cameras-used-for-myocardial-perfusion-imaging
#11
Julien Salvadori, Yolande Petegnief, Remi Sabbah, Olivier Morel, Hatem Boulahdour, Gilles Karcher, Pierre-Yves Marie, Laetitia Imbert
This phantom-based study was aimed to determine whether cardiac CZT-cameras, which provide an enhanced spatial resolution and image contrast compared to Anger cameras, are similarly affected by small cardiac motions. Translations of a left ventricular (LV) insert at half-SPECT acquisitions through six possible orthogonal directions and with 5- or 10-mm amplitude were simulated on the Discovery NM-530c and DSPECT CZT-cameras and on an Anger Symbia T2 camera equipped with an astigmatic (IQ.SPECT) or conventional parallel-hole collimator (Conv...
January 11, 2018: Journal of Nuclear Cardiology: Official Publication of the American Society of Nuclear Cardiology
https://www.readbyqxmd.com/read/29242727/evaluation-of-cadmium-zinc-telluride-detector-based-single-photon-emission-computed-tomography-for-nuclear-cardiology-a-comparison-with-conventional-anger-single-photon-emission-computed-tomography
#12
Takanaga Niimi, Mamoru Nanasato, Mitsuo Sugimoto, Hisatoshi Maeda
Purpose: The differences in performance between the cadmium-zinc-telluride (CZT) camera or collimation systems and conventional Anger single-photon emission computed tomography (A-SPECT) remain insufficient from the viewpoint of the user. We evaluated the performance of the D-SPECT (Spectrum Dynamics, Israel) system to provide more information to the cardiologist or radiological technologist about its use in the clinical field. Materials and Methods: This study evaluated the performance of the D-SPECT system in terms of energy resolution, detector sensitivity, spatial resolution, modulation transfer function (MTF), and collimator resolution in comparison with that of A-SPECT (Bright-View, Philips, Japan)...
December 2017: Nuclear Medicine and Molecular Imaging
https://www.readbyqxmd.com/read/29237072/appropriate-choice-of-stress-modality-in-patients-undergoing-myocardial-perfusion-scintigraphy-with-a-cardiac-camera-equipped-with-solid-state-detectors-the-role-of-diabetes-mellitus
#13
Alessia Gimelli, Riccardo Liga, Alberto Clemente, Emilio Maria Pasanisi, Brunella Favilli, Paolo Marzullo
Aims: To evaluate the impact of diabetes mellitus (DM) on the accuracy of myocardial perfusion scintigraphy (MPS) in detecting coronary artery disease (CAD). Methods and results: Two hundred and sixteen patients with DM and 432 matched controls were submitted to MPS on a dedicated cardiac camera equipped with cadmium-zinc-telluride (CZT) detectors and coronary angiography. Exercise stress was performed in 442 (68%) patients, while the remainders underwent vasodilator stress...
December 11, 2017: European Heart Journal Cardiovascular Imaging
https://www.readbyqxmd.com/read/29131809/positioning-true-coincidences-that-undergo-inter-and-intra-crystal-scatter-for-a-sub-mm-resolution-cadmium-zinc-telluride-based-pet-system
#14
Shiva Abbaszadeh, Garry Chinn, Craig S Levin
The kinematics of Compton scatter can be used to estimate the interaction sequence of inter-crystal scatter interactions in 3D position-sensitive cadmium zinc telluride (CZT) detectors. However, in the case of intra-crystal scatter in a 'cross-strip' CZT detector slab, multiple anode and cathode strips may be triggered, creating position ambiguity due to uncertainty in possible combinations of anode-cathode pairings. As a consequence, methods such as energy-weighted centroid are not applicable to position the interactions...
January 9, 2018: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/29127244/imaging-of-the-thyroid-and-parathyroid-using-a-cardiac-cadmium-zinc-telluride-camera-phantom-studies
#15
Yosuke Miyazaki, Yasuhiro Kato, Akira Imoto, Kazuki Fukuchi
Purpose: Cadmium zinc telluride (CZT) detectors have recently been introduced to the field of clinical nuclear cardiology. However, the feasibility of using them for organs other than the heart remains unclear. The aim of this study was to evaluate the potential of a cardiac CZT camera to acquire thyroid and parathyroid images. We used custom-made phantoms and the currently available standard protocols for CZT, instead of a sodium-iodine scintillation (NaI) camera. Materials and Methods: Thyroid phantoms with or without parathyroid adenomas were made from agar using radiopharmaceuticals ((99m)Tc or (123)I) and imaged using CZT and NaI cameras...
November 10, 2017: Journal of Nuclear Medicine Technology
https://www.readbyqxmd.com/read/29114176/detecting-triple-vessel-disease-with-cadmium-zinc-telluride-based-single-photon-emission-computed-tomography-using-the-intensity-signal-to-noise-ratio-between-rest-and-stress-studies
#16
Yu-Hua Dean Fang, Tzu-Pei Su, Chi-Jen Chang, Kung-Chu Ho, May Su, Tzu-Chen Yen
The purpose of this study was to investigate if a novel parameter, the stress-to-rest ratio of the signal-to-noise ratio (RSNR) obtained with a cadmium zinc telluride (CZT) SPECT scanner, could be used to distinguish triple-vessel disease (TVD) patients. Methods . One hundred and two patients with suspected coronary artery disease were retrospectively involved. Each subject underwent a Tl-201 SPECT scan and subsequent coronary angiography. Subjects were separated into TVD ( n = 41) and control ( n = 61) groups based on coronary angiography results using 50% as the stenosis cutoff...
2017: Contrast Media & Molecular Imaging
https://www.readbyqxmd.com/read/29074271/insical-a-tool-for-calculating-calibration-factors-and-activity-concentrations-in-in-situ-gamma-spectrometry
#17
Alexander Mauring, Tim Vidmar, Torbjörn Gäfvert, Jon Drefvelin, Aldo Fazio
In situ gamma spectrometry is a widely applied analysis technique for the determination of radioactivity levels in soil. Compared to traditional laboratory analysis of soil samples, in situ techniques offer a quick and low-cost way of obtaining accurate results from on-site measurements. However, although the technique is well-known, the dependence of in situ gamma spectrometry on complex and time-consuming calibration procedures as well as in-depth knowledge of the geometric distribution of the source in the ground deters many potential users from employing it in their routine work...
October 23, 2017: Journal of Environmental Radioactivity
https://www.readbyqxmd.com/read/29072608/precise-aperture-dependent-motion-compensation-with-frequency-domain-fast-back-projection-algorithm
#18
Man Zhang, Guanyong Wang, Lei Zhang
Precise azimuth-variant motion compensation (MOCO) is an essential and difficult task for high-resolution synthetic aperture radar (SAR) imagery. In conventional post-filtering approaches, residual azimuth-variant motion errors are generally compensated through a set of spatial post-filters, where the coarse-focused image is segmented into overlapped blocks concerning the azimuth-dependent residual errors. However, image domain post-filtering approaches, such as precise topography- and aperture-dependent motion compensation algorithm (PTA), have difficulty of robustness in declining, when strong motion errors are involved in the coarse-focused image...
October 26, 2017: Sensors
https://www.readbyqxmd.com/read/29043554/evaluation-of-left-ventricular-mass-on-cadmium-zinc-telluride-imaging-validation-against-cardiac-magnetic-resonance
#19
Alessia Gimelli, Riccardo Liga, Serena Magro, Salvatore Novo, Roberto Pedrinelli, Anna Sonia Petronio, Paolo Marzullo, Alessia Pepe
BACKGROUND: Single-photon emission computed tomography has shown relevant limitations in the quantification of left ventricular (LV) mass. We sought to compare the estimates of LV mass on Cadmium-Zinc-Telluride (CZT) myocardial perfusion imaging (MPI) as compared to cardiac magnetic resonance (CMR). METHODS AND RESULTS: Twenty-five patients underwent MPI on a CZT camera and CMR on a 1.5 T scanner within 12 ± 3 weeks. LV mass was quantified on CZT images using two softwares: 4D-MSPECT (4DM) and Emory Cardiac Toolbox (ECTb)...
October 17, 2017: Journal of Nuclear Cardiology: Official Publication of the American Society of Nuclear Cardiology
https://www.readbyqxmd.com/read/28865679/quantification-of-myocardial-perfusion-reserve-using-dynamic-spect-images-of-patients-with-chronic-kidney-disease
#20
Noriko Tsuda, Shinya Shiraishi, Fumi Sakamoto, Hideaki Yuki, Koji Ogasawara, Morikatsu Yoshida, Seiji Tomiguchi, Kenichi Tsujita, Yasuyuki Yamashita
BACKGROUND: Chronic kidney disease (CKD) is an independent risk factor for cardiovascular disorders. The aim of this study was to examine whether the quantitatively measured myocardial blood flow (MBF) or myocardial perfusion reserve (MPR), calculated by dynamic single photon emission computed tomography (SPECT) analysis using a cardiac cadmium zinc telluride (CZT) gamma camera, was related to renal dysfunction in patients with normal myocardial perfusion imaging (MPI) findings. METHODS: The study population consisted of 46 patients with CKD and 46 individuals without CKD (controls)...
February 2018: Journal of Cardiology
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