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Michael Ljungberg, P Hendrik Pretorius
Functional nuclear medicine imaging with Single-Photon Emission Computed Tomography (SPECT) in combination with anatomical Computed Tomography (CT) has been commercially available since the beginning of this century. The combination of the two modalities has improved both sensitivity and specificity of many clinical applications and CT in conjunction with SPECT allows for spatial overlay of the SPECT data on good anatomy images. Introduction of diagnostic CT units as part of the SPECT/CT system has also potentially allowed for a more cost-efficient use of the equipment...
November 15, 2016: British Journal of Radiology
Tanguy Blaire, Alban Bailliez, Fayçal Ben Bouallegue, Dimitri Bellevre, Denis Agostini, Alain Manrique
BACKGROUND: The impact of increased energy resolution of cadmium-zinc-telluride (CZT) cameras on the assessment of left ventricular function under dual-isotope conditions ((99m)Tc and (123)I) remains unknown. The Amsterdam-gated dynamic cardiac phantom (AGATE, Vanderwilt techniques, Boxtel, The Netherlands) was successively filled with a solution of (123)I alone, (99m)Tc alone, and a mixture of (123)I and (99m)Tc. A total of 12 datasets was acquired with each commercially available CZT camera (DNM 530c, GE Healthcare and DSPECT, Biosensors International) using both energy windows ((99m)Tc or (123)I) with ejection fraction set to 33, 45, and 60 %...
December 2016: EJNMMI Physics
Steven M Jorgensen, Andrew J Vercnocke, David S Rundle, Philip H Butler, Cynthia H McCollough, Erik L Ritman
We assessed the performance of a cadmium zinc telluride (CZT)-based Medipix3RX x-ray detector as a candidate for micro-computed tomography (micro-CT) imaging. This technology was developed at CERN for the Large Hadron Collider. It features an array of 128 by 128, 110 micrometer square pixels, each with eight simultaneous threshold counters, five of which utilize real-time charge summing, significantly reducing the charge sharing between contiguous pixels. Pixel response curves were created by imaging a range of x-ray intensities by varying x-ray tube current and by varying the exposure time with fixed x-ray current...
August 28, 2016: Proceedings of SPIE
Marine Claudin, Laetitia Imbert, Wassila Djaballah, Nicolas Veran, Sylvain Poussier, Véronique Roch, Mathieu Perrin, Antoine Verger, Henri Boutley, Gilles Karcher, Pierre-Yves Marie
PURPOSE: Gamma-cameras, with Cadmium-Zinc-Telluride (CZT) detectors, allow to perform myocardial perfusion imaging (MPI) with limited injected activities and recorded times. This study aimed at determining whether the routine assessment of left ventricular (LV) function with such limited counts protocols compares well with reference values from cardiac MRI. METHODS: The study included patients who have undergone cardiac MRI and an MPI routinely planned on a CZT camera with a low-dose protocol (120 MBq of Sestamibi for stress and 360 MBq at rest for 75 kg body weight), while targeting the recording of only 500 myocardial kcounts in order to limit the recording times (<10 minutes for stress, <4 minutes for rest)...
September 27, 2016: Journal of Nuclear Cardiology: Official Publication of the American Society of Nuclear Cardiology
A M Ferrari-Lima, A C Ueda, E A Bergamo, R G Marques, E A V Ferri, C S Pinto, C A A Pereira, P H Yassue-Cordeiro, R P Souza
Calcium titanate zirconate, Ca(Ti(1-x)Zrx)O3 (CZT), powders have been synthesised by the polymeric precursor method. The structural analysis of the CZT powders was monitored by X-ray diffraction (XRD), photoacoustic spectroscopy (PAS) and textural analysis. The photocatalytic properties were evaluated by methylene blue (MB) decomposition and real textile wastewater (RTW) combined treatment (coagulation/flocculation/photocatalysis). Chemical oxygen demand (COD) of RTW was successfully reduced from 6195 mg L(-1) (untreated) to 662 mg L(-1) after coagulation/flocculation with a tannin-based coagulant (Tanfloc®) and finally to 471 mg L(-1) after combined treatment (coagulation/flocculation/photocatalysis) applying ultraviolet radiation and CaTiO3 as photocatalyst...
September 10, 2016: Environmental Science and Pollution Research International
Shiva Abbaszadeh, Yi Gu, Paul D Reynolds, Craig S Levin
Cadmium zinc telluride (CZT) offers key advantages for small animal positron emission tomography (PET), including high spatial and energy resolution and simple metal deposition for fabrication of very small pixel arrays. Previous studies have investigated the intrinsic spatial, energy, and timing resolution of an individual sub-millimeter resolution CZT detector. In this work we present the first characterization results of a system of these detectors. The 3D position sensitive dual-CZT detector module and readout electronics developed in our lab was scaled up to complete a significant portion of the final PET system...
September 21, 2016: Physics in Medicine and Biology
Denis Agostini, Pierre-Yves Marie, Simona Ben-Haim, François Rouzet, Bernard Songy, Alessandro Giordano, Alessia Gimelli, Fabien Hyafil, Roberto Sciagrà, Jan Bucerius, Hein J Verberne, Riemer H J A Slart, Oliver Lindner
The trade-off between resolution and count sensitivity dominates the performance of standard gamma cameras and dictates the need for relatively high doses of radioactivity of the used radiopharmaceuticals in order to limit image acquisition duration. The introduction of cadmium-zinc-telluride (CZT)-based cameras may overcome some of the limitations against conventional gamma cameras. CZT cameras used for the evaluation of myocardial perfusion have been shown to have a higher count sensitivity compared to conventional single photon emission computed tomography (SPECT) techniques...
December 2016: European Journal of Nuclear Medicine and Molecular Imaging
Doumit Daou, Remy Sabbah, Carlos Coaguila, Hatem Boulahdour
No abstract text is available yet for this article.
August 18, 2016: Journal of Nuclear Cardiology: Official Publication of the American Society of Nuclear Cardiology
Ronaldo Lima, Thais Peclat, Thalita Soares, Caio Ferreira, Ana Carolina Souza, Gabriel Camargo
BACKGROUND: Recent studies have shown that myocardial perfusion imaging (MPI) in cadmium-zinc-telluride (CZT) cameras allow faster exams with less radiation dose but there are little data comparing its prognosis information with that of dedicated cardiac Na-I SPECT cameras OBJECTIVE: The objective of this study is to compare the prognostic value of MPI using an ultrafast protocol with low radiation dose in a CZT-SPECT and a traditional one. METHODS: Group 1 was submitted to a two-day MIBI protocol in a conventional camera, and group 2 was submitted to a 1-day MIBI protocol in CZT camera...
August 10, 2016: Journal of Nuclear Cardiology: Official Publication of the American Society of Nuclear Cardiology
Bernard Songy, Mohamed Guernou, Daniel Hivoux, David Attias, David Lussato, Mathieu Queneau, Gerald Bonardel, Marc Bertaux
: The aim of this study was to assess the prognostic value of normal ultra-low-dose exercise MPI with a CZT camera. METHODS: 1901 consecutive patients without known CAD referred for exercise MPI with 1.8 MBq/kg (0.05 mCi) of Tc99m sestamibi or tetrofosmin and a CZT camera were included prospectively. Patients with an abnormal scan requiring an additional resting image (230) or a submaximal exercise test (271) were excluded. The 1400 remaining patients were followed for 39 months...
August 9, 2016: Journal of Nuclear Cardiology: Official Publication of the American Society of Nuclear Cardiology
A Andreyev, A Celler, I Ozsahin, A Sitek
PURPOSE: Compton cameras (CCs) use electronic collimation to reconstruct the images of activity distribution. Although this approach can greatly improve imaging efficiency, due to complex geometry of the CC principle, image reconstruction with the standard iterative algorithms, such as ordered subset expectation maximization (OSEM), can be very time-consuming, even more so if resolution recovery (RR) is implemented. We have previously shown that the origin ensemble (OE) algorithm can be used for the reconstruction of the CC data...
August 2016: Medical Physics
Federico Caobelli, Tim Wollenweber, Udo Bavendiek, Christian Kühn, Christian Schütze, Lilli Geworski, James T Thackeray, Johann Bauersachs, Axel Haverich, Frank M Bengel
AIMS: High-energy resolution and sensitivity of novel cadmium-zinc-telluride (CZT) detector equipped SPECT systems facilitate simultaneous imaging of multiple isotopes and may enhance the detection of molecular/cellular signals. This may refine the detection of endocarditis. This study was designed to determine the feasibility and diagnostic accuracy of simultaneous imaging of inflammation with (111)In-labeled white blood cells (WBCs) and myocardial perfusion with (99m)Tc-sestamibi, for localization of WBCs relative to the valve plane in suspected endocarditis...
July 28, 2016: European Heart Journal
Alessia Gimelli, Francesca Menichetti, Ezio Soldati, Riccardo Liga, Andrea Vannozzi, Paolo Marzullo, Maria Grazia Bongiorni
PURPOSE: To assess the relationship between regional myocardial perfusion and sympathetic innervation parameters at myocardial scintigraphy and intra-cavitary electrophysiological data in patients with ventricular arrhythmias (VA) submitted to invasive electrophysiological study and ablation procedure. METHODS: Sixteen subjects underwent invasive electrophysiological study with electroanatomical mapping (EAM) followed by trans-catheter ablations of VA. Before ablation all patients were studied with a combined evaluation of regional myocardial perfusion and sympathetic innervation by means of tomographic (99m)Tc-tetrofosmin and (123)I- metaiodobenzylguanidine cadmium-zinc-telluride (CZT) scintigraphies, respectively...
July 19, 2016: European Journal of Nuclear Medicine and Molecular Imaging
John A Kennedy, H William Strauss
A solid-state cadmium zinc tellurium (CZT) dedicated multipinhole cardiac camera which acquires all views simultaneously has been introduced for myocardial SPECT acquisition. We report a method to detect and ameliorate patient motion artifacts in myocardial perfusion imaging (MPI) studies recorded with this device. To detect motion, a myocardial phantom study was recorded, and at mid-scan, the phantom was moved stepwise along each of 6 orthogonal directions, causing MPI artifacts. Using QPS software (Cedars-Sinai) and an in-house normal database, displacements giving artifactual perfusion defects (total perfusion deficit score, TPD, >5 %) were all 1...
July 14, 2016: Medical & Biological Engineering & Computing
H Chung, C Zhou, X T Tee, K-Y Jung, P Bermel
Tandem solar cells consisting of high bandgap cadmium telluride alloys atop crystalline silicon have potential for high efficiencies exceeding the Shockley-Queisser limit. However, experimental results have fallen well below this goal significantly because of non-ideal current matching and light trapping. In this work, we simulate cadmium zinc telluride (CZT) and crystalline silicon (c-Si) tandems as an exemplary system to show the role that a hybrid light trapping and bandgap engineering approach can play in improving performance and lowering materials costs for tandem solar cells incorporating crystalline silicon...
July 11, 2016: Optics Express
Joris D van Dijk, Jorn A van Dalen, Mohamed Mouden, Jan Paul Ottervanger, Siert Knollema, Cornelis H Slump, Pieter L Jager
BACKGROUND: Correction of motion has become feasible on cadmium-zinc-telluride (CZT)-based SPECT cameras during myocardial perfusion imaging (MPI). Our aim was to quantify the motion and to determine the value of automatic correction using commercially available software. METHODS AND RESULTS: We retrospectively included 83 consecutive patients who underwent stress-rest MPI CZT-SPECT and invasive fractional flow reserve (FFR) measurement. Eight-minute stress acquisitions were reformatted into 1...
July 12, 2016: Journal of Nuclear Cardiology: Official Publication of the American Society of Nuclear Cardiology
Rene Nkoulou, Tobias A Fuchs, Aju P Pazhenkottil, Silke M Kuest, Jelena R Ghadri, Julia Stehli, Michael Fiechter, Bernhard A Herzog, Oliver Gaemperli, Ronny R Buechel, Philipp A Kaufmann
: Recent advances in SPECT technology including cadmium-zinc-telluride (CZT) semiconductor detector material may pave the way for absolute myocardial blood flow (MBF) measurements by SPECT. The aim of the present study was to compare K1 uptake rate constants as surrogates of absolute MBF and myocardial flow reserve index (MFRi) in humans as assessed with a CZT SPECT camera versus PET. METHODS: Absolute MBF was assessed in 28 consecutive patients undergoing adenosine stress-rest myocardial perfusion imaging (MPI) by (99m)Tc-tetrofosmin CZT SPECT and (13)N-ammonia PET, and MFR was calculated as a ratio of hyperemic over resting MBF...
December 2016: Journal of Nuclear Medicine: Official Publication, Society of Nuclear Medicine
Jianyu Shang, Zhihong Deng, Mengyin Fu, Shunting Wang
Traditional artillery guidance can significantly improve the attack accuracy and overall combat efficiency of projectiles, which makes it more adaptable to the information warfare of the future. Obviously, the accurate measurement of artillery spin rate, which has long been regarded as a daunting task, is the basis of precise guidance and control. Magnetoresistive (MR) sensors can be applied to spin rate measurement, especially in the high-spin and high-g projectile launch environment. In this paper, based on the theory of a MR sensor measuring spin rate, the mathematical relationship model between the frequency of MR sensor output and projectile spin rate was established through a fundamental derivation...
2016: Sensors
Yasmine A Mota, Caroline Cotes, Rodrigo F Carvalho, João P B Machado, Fabíola P P Leite, Rodrigo O A Souza, Mutlu Özcan
OBJECTIVES: This study evaluated the influence of two aging procedures on the biaxial flexural strength of yttria-stabilized tetragonal zirconia ceramics. MATERIAL AND METHODS: Disc-shaped zirconia specimens and (ZE: E.max ZirCAD, Ivoclar; ZT: Zirkon Translucent, Zirkonzahn) (N = 80) (∅:12 mm; thickness:1.2 mm, ISO 6872) were prepared and randomly divided into four groups (n = 10 per group) according to the aging procedures: C: Control, no aging; M: mechanical cycling (2 × 10(6) cycles/3...
June 17, 2016: Journal of Biomedical Materials Research. Part B, Applied Biomaterials
Zenith A Jameria, Mouhamad Abdallah, Alok Dwivedi, Erica Washburn, Naseer Khan, Mahyar Khaleghi, Nischelle Kalakota, Myron C Gerson
BACKGROUND: Transient ischemic dilation (TID) of the left ventricle (LV) has not been validated as a marker of extensive coronary artery disease (CAD) for studies using a cadmium-zinc-telluride (CZT) camera with upright imaging. METHODS: TID ratios were obtained from upright stress and rest images on a CZT camera. Separate cut-off values were determined for exercise and for regadenoson stress. The cutoffs were then applied to 28 patients with extensive CAD and 101 patients without extensive CAD...
June 16, 2016: Journal of Nuclear Cardiology: Official Publication of the American Society of Nuclear Cardiology
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