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Sample records for water pet high

  1. Myocardial perfusion quantitation with {sup 15}O-labelled water PET: high reproducibility of the new cardiac analysis software (Carimas trademark)

    Energy Technology Data Exchange (ETDEWEB)

    Nesterov, Sergey V. [University of Turku, Turku PET Centre, P.O. Box 52, Turku (Finland); Russian Academy of Sciences, IM Sechenov Institute of Evolutionary Physiology and Biochemistry, St. Petersburg (Russian Federation); Han, Chunlei; Kajander, Sami; Knuuti, Juhani [University of Turku, Turku PET Centre, P.O. Box 52, Turku (Finland); Maeki, Maija [University of Turku, Department of Clinical Physiology and Nuclear Medicine, Turku University Hospital, Turku (Finland); Naum, Alexandru G. [University of Turku, Turku PET Centre, P.O. Box 52, Turku (Finland); University of Bergen, Nuclear Medicine and PET Centre, Haukeland University Hospital, Bergen (Norway); Helenius, Hans [University of Turku, Department of Biostatistics, Turku (Finland); Lisinen, Irina [University of Turku, Research Centre of Applied and Preventive Cardiovascular Medicine, Turku (Finland); Ukkonen, Heikki; Pietilae, Mikko; Joutsiniemi, Esa [Turku University Hospital, Department of Internal Medicine, Turku (Finland)

    2009-10-15

    Carimas trademark (Cardiac Image Analysis System) is a new software package developed at the Turku PET Centre for the quantitation of PET studies of the heart with a broad range of tracers. The goal of this study was to assess the reproducibility of results the package provides for myocardial perfusion (MP) quantitation using {sup 15}O-labelled water. Four observers with various levels of experience in nuclear medicine independently analysed 20 MP studies (10 rest flow: ''rest'', 10 adenosine-induced hyperaemia: ''stress''). Each study was analysed twice. The linear mixed model for repeated measures was fitted to the data to calculate intraclass correlation coefficients (ICC), differences between the repeats (the intraobserver differences) and differences between the observers (the interobserver differences). Also, Pearson correlation coefficients (r) were calculated and Bland-Altman plots were drawn. The reproducibility of MP was assessed on global, regional and segmental levels. Thereafter, this analysis was applied in 48 consecutive clinical patients with suspected coronary heart disease (CHD). For the experienced observer the Pearson r for all segments was 0.974 at rest and 0.978 at stress (p < 0.0001), and the repeatability coefficients were 0.145 ml/g per min (15.5% of the average) and 0.389 ml/g per min (14.9%), correspondingly. The ICC reflected very good overall reproducibility. The intraobserver and interobserver differences were small, and the difference between the most and the least experienced observers at stress was 8.5% for the global MP. The clinical accuracy of the perfusion in the detection of CHD was excellent (positive predictive value 91% and negative predictive value 88%) against invasive angiography. The results demonstrate high reproducibility of myocardial perfusion quantitation with {sup 15}O-labelled water PET using Carimas trademark. The results support the feasibility of robust analysis and good

  2. The AX-PET project Demonstration of a high resolution axial 3D PET

    CERN Document Server

    Bolle, E; Casella, C; Chesi, E; Clinthorne, N; Cochran, E; De Leo, R; Dissertori, G; Djambazov, G; Fanti, V; Honscheid, K; Huh, S; Johnson, I; Joram, C; Kagan, H; Lustermann, W; Meddi, F; Nappi, E; Nessi-Tedaldi, F; Oliver, J F; Pauss, P; Rafecas, M; Renker, D; Rudge, A; Schinzel, D; Schneider, T; Seguinot, J; Smith, S; Solevi, P; Stapnes, S; Weilhammer, P

    2010-01-01

    The AX-PET is a new geometrical concept for a high resolution 3D PET scanner, based on matrices of axially oriented LYSO crystals interleaved by stacks of WLS, both individually read out by G-APDs. A PET demonstrator, based on two detector modules used in coincidence, is currently under construction.

  3. Assessment of endothelial function and myocardial flow reserve using {sup 15}O-water PET without attenuation correction

    Energy Technology Data Exchange (ETDEWEB)

    Tuffier, Stephane; Joubert, Michael; Bailliez, Alban [EA 4650, Normandie Universite, Caen (France); Legallois, Damien [EA 4650, Normandie Universite, Caen (France); Caen University Hospital, Department of Cardiology, Caen (France); Belin, Annette [Caen University Hospital, Department of Cardiac Surgery, Caen (France); Redonnet, Michel [Rouen University Hospital, Department of Cardiac Surgery, Rouen (France); Agostini, Denis [EA 4650, Normandie Universite, Caen (France); Caen University Hospital, Department of Nuclear Medicine, Caen (France); Manrique, Alain [EA 4650, Normandie Universite, Caen (France); Caen University Hospital, Department of Nuclear Medicine, Caen (France); Cyceron PET Centre, Caen (France)

    2016-02-15

    Myocardial blood flow (MBF) measurement using positron emission tomography (PET) from the washout rate of {sup 15}O-water is theoretically independent of tissue attenuation. The aim of this study was to evaluate the impact of not using attenuation correction in the assessment of coronary endothelial function and myocardial flow reserve (MFR) using {sup 15}O-water PET. We retrospectively processed 70 consecutive {sup 15}O-water PET examinations obtained at rest and during cold pressor testing (CPT) in patients with dilated cardiomyopathy (n = 58), or at rest and during adenosine infusion in heart transplant recipients (n = 12). Data were reconstructed with attenuation correction (AC) and without attenuation correction (NAC) using filtered backprojection, and MBF was quantified using a single compartmental model. The agreement between AC and NAC data was assessed using Lin's concordance correlation coefficient followed by Bland-Altman plot analysis. Regarding endothelial function, NAC PET showed poor reproducibility and poor agreement with AC PET data. Conversely, NAC PET demonstrated high reproducibility and a strong agreement with AC PET for the assessment of MFR. Non-attenuation-corrected {sup 15}O-water PET provided an accurate measurement of MFR compared to attenuation-corrected PET. However, non-attenuation-corrected PET data were less effective for the assessment of endothelial function using CPT in this population. (orig.)

  4. High-Resolution PET Detector. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Karp, Joel

    2014-03-26

    The objective of this project was to develop an understanding of the limits of performance for a high resolution PET detector using an approach based on continuous scintillation crystals rather than pixelated crystals. The overall goal was to design a high-resolution detector, which requires both high spatial resolution and high sensitivity for 511 keV gammas. Continuous scintillation detectors (Anger cameras) have been used extensively for both single-photon and PET scanners, however, these instruments were based on NaI(Tl) scintillators using relatively large, individual photo-multipliers. In this project we investigated the potential of this type of detector technology to achieve higher spatial resolution through the use of improved scintillator materials and photo-sensors, and modification of the detector surface to optimize the light response function.We achieved an average spatial resolution of 3-mm for a 25-mm thick, LYSO continuous detector using a maximum likelihood position algorithm and shallow slots cut into the entrance surface.

  5. Quantitative myocardial perfusion by O-15-water PET

    DEFF Research Database (Denmark)

    Thomassen, Anders; Petersen, Henrik; Johansen, Allan

    2015-01-01

    disease (CAD). METHODS AND RESULTS: Forty-four patients with suspected CAD were included prospectively and underwent coronary CT-angiography and quantitative MBF assessment with O-15-water PET followed by invasive, quantitative coronary angiography, which served as reference. MBF was calculated...

  6. Performance evaluation of a high resolution dedicated breast PET scanner

    Energy Technology Data Exchange (ETDEWEB)

    García Hernández, Trinitat, E-mail: mtrinitat@eresa.com; Vicedo González, Aurora; Brualla González, Luis; Granero Cabañero, Domingo [Department of Medical Physics, ERESA, Hospital General Universitario, Valencia 46014 (Spain); Ferrer Rebolleda, Jose; Sánchez Jurado, Raúl; Puig Cozar Santiago, Maria del [Department of Nuclear Medicine, ERESA, Hospital General Universitario, Valencia 46014 (Spain); Roselló Ferrando, Joan [Department of Medical Physics, ERESA, Hospital General Universitario, Valencia 46014 (Spain); Department of Physiology, University of Valencia, Valencia 46010 (Spain)

    2016-05-15

    Purpose: Early stage breast cancers may not be visible on a whole-body PET scan. To overcome whole-body PET limitations, several dedicated breast positron emission tomography (DbPET) systems have emerged nowadays aiming to improve spatial resolution. In this work the authors evaluate the performance of a high resolution dedicated breast PET scanner (Mammi-PET, Oncovision). Methods: Global status, uniformity, sensitivity, energy, and spatial resolution were measured. Spheres of different sizes (2.5, 4, 5, and 6 mm diameter) and various 18 fluorodeoxyglucose ({sup 18}F-FDG) activity concentrations were randomly inserted in a gelatine breast phantom developed at our institution. Several lesion-to-background ratios (LBR) were simulated, 5:1, 10:1, 20:1, 30:1, and 50:1. Images were reconstructed using different voxel sizes. The ability of experienced reporters to detect spheres was tested as a function of acquisition time, LBR, sphere size, and matrix reconstruction voxel size. For comparison, phantoms were scanned in the DbPET camera and in a whole body PET (WB-PET). Two patients who just underwent WB-PET/CT exams were imaged with the DbPET system and the images were compared. Results: The measured absolute peak sensitivity was 2.0%. The energy resolution was 24.0% ± 1%. The integral and differential uniformity were 10% and 6% in the total field of view (FOV) and 9% and 5% in the central FOV, respectively. The measured spatial resolution was 2.0, 1.9, and 1.7 mm in the radial, tangential, and axial directions. The system exhibited very good detectability for spheres ≥4 mm and LBR ≥10 with a sphere detection of 100% when acquisition time was set >3 min/bed. For LBR = 5 and acquisition time of 7 min the detectability was 100% for spheres of 6 mm and 75% for spheres of 5, 4, and 2.5 mm. Lesion WB-PET detectability was only comparable to the DbPET camera for lesion sizes ≥5 mm when acquisition time was >3 min and LBR > 10. Conclusions: The DbPET has a good

  7. Breast cancer detection using high-resolution breast PET compared to whole-body PET or PET/CT

    Energy Technology Data Exchange (ETDEWEB)

    Kalinyak, Judith E. [Naviscan Inc., San Diego, CA (United States); Berg, Wendie A. [University of Pittsburgh School of Medicine, Magee-Womens Hospital, Pittsburgh, PA (United States); Schilling, Kathy [Boca Raton Regional Hospital, Boca Raton, FL (United States); Madsen, Kathleen S. [Certus International, Inc., St. Louis, MO (United States); Narayanan, Deepa [Naviscan Inc., San Diego, CA (United States); National Cancer Institute, Bethesda, MD (United States); Tartar, Marie [Scripps Clinic, Scripps Green Hospital, La Jolla, CA (United States)

    2014-02-15

    To compare the performance characteristics of positron emission mammography (PEM) with those of whole-body PET (WBPET) and PET/CT in women with newly diagnosed breast cancer. A total of 178 women consented to PEM for presurgical planning in an IRB-approved protocol and also underwent either WBPET (n = 69) or PET/CT (n = 109) imaging, as per usual care at three centers. Tumor detection sensitivity, positive predictive values, and {sup 18}F-fluorodeoxyglucose (FDG) uptake were compared between the modalities. The effects of tumor size, type, and grade on detection were examined. The chi-squared or Fisher's exact tests were used to compare distributions between groups, and McNemar's test was used to compare distributions for paired data within subject groups, i.e. PEM versus WBPET or PEM versus PET/CT. The mean age of the women was 59 ± 12 years (median 60 years, range 26-89 years), with a mean invasive index tumor size of 1.6 ± 0.8 cm (median 1.5 cm, range 0.5-4.0 cm). PEM detected more index tumors (61/66, 92 %) than WBPET (37/66, 56 %; p < 0.001) or PET/CT (95/109, 87 % vs. 104/109, 95 % for PEM; p < 0.029). Sensitivity for the detection of additional ipsilateral malignancies was also greater with PEM (7/15, 47 %) than with WBPET (1/15, 6.7 %; p = 0.014) or PET/CT (3/23, 13 % vs. 13/23, 57 % for PEM; p = 0.003). Index tumor detection decreased with decreasing invasive tumor size for both WBPET (p = 0.002) and PET/CT (p < 0.001); PEM was not significantly affected (p = 0.20). FDG uptake, quantified in terms of maximum PEM uptake value, was lowest in ductal carcinoma in situ (median 1.5, range 0.7-3.0) and invasive lobular carcinoma (median 1.5, range 0.7-3.4), and highest in grade III invasive ductal carcinoma (median 3.1, range 1.4-12.9). PEM was more sensitive than either WBPET or PET/CT in showing index and additional ipsilateral breast tumors and remained highly sensitive for tumors smaller than 1 cm. (orig.)

  8. Antimony leaching from polyethylene terephthalate (PET) plastic used for bottled drinking water.

    Science.gov (United States)

    Westerhoff, Paul; Prapaipong, Panjai; Shock, Everett; Hillaireau, Alice

    2008-02-01

    Antimony is a regulated contaminant that poses both acute and chronic health effects in drinking water. Previous reports suggest that polyethylene terephthalate (PET) plastics used for water bottles in Europe and Canada leach antimony, but no studies on bottled water in the United States have previously been conducted. Nine commercially available bottled waters in the southwestern US (Arizona) were purchased and tested for antimony concentrations as well as for potential antimony release by the plastics that compose the bottles. The southwestern US was chosen for the study because of its high consumption of bottled water and elevated temperatures, which could increase antimony leaching from PET plastics. Antimony concentrations in the bottled waters ranged from 0.095 to 0.521 ppb, well below the US Environmental Protection Agency (USEPA) maximum contaminant level (MCL) of 6 ppb. The average concentration was 0.195+/-0.116 ppb at the beginning of the study and 0.226+/-0.160 ppb 3 months later, with no statistical differences; samples were stored at 22 degrees C. However, storage at higher temperatures had a significant effect on the time-dependent release of antimony. The rate of antimony (Sb) release could be fit by a power function model (Sb(t)=Sb 0 x[Time, h]k; k=8.7 x 10(-6)x[Temperature ( degrees C)](2.55); Sb 0 is the initial antimony concentration). For exposure temperatures of 60, 65, 70, 75, 80, and 85 degrees C, the exposure durations necessary to exceed the 6 ppb MCL are 176, 38, 12, 4.7, 2.3, and 1.3 days, respectively. Summertime temperatures inside of cars, garages, and enclosed storage areas can exceed 65 degrees C in Arizona, and thus could promote antimony leaching from PET bottled waters. Microwave digestion revealed that the PET plastic used by one brand contained 213+/-35 mgSb/kg plastic; leaching of all the antimony from this plastic into 0.5L of water in a bottle could result in an antimony concentration of 376 ppb. Clearly, only a small

  9. PET

    DEFF Research Database (Denmark)

    Mariager, Rasmus Mølgaard; Schmidt, Regin; Heiberg, Morten Rievers

    PET handler om den hemmelige tjenestes arbejde under den kolde krig 1945-1989. Her fortæller Regin Schmidt, Rasmus Mariager og Morten Heiberg om de mest dramatiske og interessante sager fra PET's arkiv. PET er på flere måder en udemokratisk institution, der er sat til at vogte over demokratiet....... Dens virksomhed er skjult for offentligheden, den overvåger borgernes aktiviteter, og den registrerer følsomme personoplysninger. Historien om PET rejser spørgsmålet om, hvad man skal gøre, når befolkningen i et demokrati er kritisk indstillet over for overvågningen af lovlige politiske aktiviteter......, mens myndighederne mener, at det er nødvendigt for at beskytte demokratiet. PET er på en gang en fortælling om konkrete aktioner og begivenheder i PET's arbejde og et stykke Danmarkshistorie. Det handler om overvågning, spioner, politisk ekstremisme og international terrorisme.  ...

  10. Simultaneous water activation and glucose metabolic rate imaging with PET.

    Science.gov (United States)

    Verhaeghe, Jeroen; Reader, Andrew J

    2013-02-07

    A novel imaging and signal separation strategy is proposed to be able to separate [(18)F]FDG and multiple [(15)O]H(2)O signals from a simultaneously acquired dynamic PET acquisition of the two tracers. The technique is based on the fact that the dynamics of the two tracers are very distinct. By adopting an appropriate bolus injection strategy and by defining tailored sets of basis functions that model either the FDG or water component, it is possible to separate the FDG and water signal. The basis functions are inspired from the spectral analysis description of dynamic PET studies and are defined as the convolution of estimated generating functions (GFs) with a set of decaying exponential functions. The GFs are estimated from the overall measured head curve, while the decaying exponential functions are pre-determined. In this work, the time activity curves (TACs) are modelled post-reconstruction but the model can be incorporated in a global 4D reconstruction strategy. Extensive PET simulation studies are performed considering single [(18)F]FDG and 6 [(15)O]H(2)O bolus injections for a total acquisition time of 75 min. The proposed method is evaluated at multiple noise levels and different parameters were estimated such as [(18)F]FDG uptake and blood flow estimated from the [(15)O]H(2)O component, requiring a full dynamic analysis of the two components, static images of [(18)F]FDG and the water components as well as [(15)O]H(2)O activation. It is shown that the resulting images and parametric values in ROIs are comparable to images obtained from separate imaging, illustrating the feasibility of simultaneous imaging of [(18)F]FDG and [(15)O]H(2)O components.

  11. Development of a high resolution module for PET scanners

    Science.gov (United States)

    Stringhini, G.; Pizzichemi, M.; Ghezzi, A.; Stojkovic, A.; Tavernier, S.; Niknejad, T.; Varela, J.; Paganoni, M.; Auffray, E.

    2017-02-01

    Positron Emission Tomography (PET) scanners require high performances in term of spatial resolution and sensitivity to allow early detection of cancer masses. In small animal and organ dedicated PET scanners the Depth of Interaction (DOI) information has to be obtained to avoid parallax errors and to reconstruct high resolution images. In the whole body PET, the DOI information can be useful to correct for the time jitter of the optical photons along the main axis of the scintillator, improving the time performances. In this work we present the development of PET module designed to reach high performance as compared to the current scanners while keeping the complexity of the system reasonably low. The module presented is based on a 64 LYSO (Lutetium-yttrium oxyorthosilicate) crystals matrix and on a 4×4 MPPC (Multi Pixels Photon Counter) array as detector in a 4 to 1 coupling between the crystals and the detector and a single side readout. The lateral surfaces of the crystals are optically treated to be unpolished. The DOI and the energy resolution of the PET module are presented and a fast method to obtain the DOI calibration is discussed.

  12. Simultaneous Multiparametric PET/MRI with Silicon Photomultiplier PET and Ultra-High-Field MRI for Small-Animal Imaging.

    Science.gov (United States)

    Ko, Guen Bae; Yoon, Hyun Suk; Kim, Kyeong Yun; Lee, Min Sun; Yang, Bo Yeun; Jeong, Jae Min; Lee, Dong Soo; Song, In Chan; Kim, Seok-Ki; Kim, Daehong; Lee, Jae Sung

    2016-08-01

    Visualization of biologic processes at molecular and cellular levels has revolutionized the understanding and treatment of human diseases. However, no single biomedical imaging modality provides complete information, resulting in the emergence of multimodal approaches. Combining state-of-the-art PET and MRI technologies without loss of system performance and overall image quality can provide opportunities for new scientific and clinical innovations. Here, we present a multiparametric PET/MR imager based on a small-animal dedicated, high-performance, silicon photomultiplier (SiPM) PET system and a 7-T MR scanner. A SiPM-based PET insert that has the peak sensitivity of 3.4% and center volumetric resolution of 1.92/0.53 mm(3) (filtered backprojection/ordered-subset expectation maximization) was developed. The SiPM PET insert was placed between the mouse body transceiver coil and gradient coil of a 7-T small-animal MRI scanner for simultaneous PET/MRI. Mutual interference between the MRI and SiPM PET systems was evaluated using various MR pulse sequences. A cylindric corn oil phantom was scanned to assess the effects of the SiPM PET on the MR image acquisition. To assess the influence of MRI on the PET imaging functions, several PET performance indicators including scintillation pulse shape, flood image quality, energy spectrum, counting rate, and phantom image quality were evaluated with and without the application of MR pulse sequences. Simultaneous mouse PET/MRI studies were also performed to demonstrate the potential and usefulness of the multiparametric PET/MRI in preclinical applications. Excellent performance and stability of the PET system were demonstrated, and the PET/MRI combination did not result in significant image quality degradation of either modality. Finally, simultaneous PET/MRI studies in mice demonstrated the feasibility of the developed system for evaluating the biochemical and cellular changes in a brain tumor model and facilitating the

  13. Calculation of left ventricular volumes and ejection fraction from dynamic cardiac-gated 15O-water PET/CT: 5D-PET

    Directory of Open Access Journals (Sweden)

    Jonny Nordström

    2017-11-01

    Full Text Available Abstract Background Quantitative measurement of myocardial blood flow (MBF is of increasing interest in the clinical assessment of patients with suspected coronary artery disease (CAD. 15O-water positron emission tomography (PET is considered the gold standard for non-invasive MBF measurements. However, calculation of left ventricular (LV volumes and ejection fraction (EF is not possible from standard 15O-water uptake images. The purpose of the present work was to investigate the possibility of calculating LV volumes and LVEF from cardiac-gated parametric blood volume (V B 15O-water images and from first pass (FP images. Sixteen patients with mitral or aortic regurgitation underwent an eight-gate dynamic cardiac-gated 15O-water PET/CT scan and cardiac MRI. V B and FP images were generated for each gate. Calculations of end-systolic volume (ESV, end-diastolic volume (EDV, stroke volume (SV and LVEF were performed with automatic segmentation of V B and FP images, using commercially available software. LV volumes and LVEF were calculated with surface-, count-, and volume-based methods, and the results were compared with gold standard MRI. Results Using V B images, high correlations between PET and MRI ESV (r = 0.89, p  0.86, p < 0.001. Conclusion Calculation of LV volumes and LVEF from dynamic 15O-water PET is feasible and shows good correlation with MRI. However, the analysis method is laborious, and future work is needed for more automation to make the method more easily applicable in a clinical setting.

  14. Highly adhesive and high fatigue-resistant copper/PET flexible electronic substrates

    Science.gov (United States)

    Park, Sang Jin; Ko, Tae-Jun; Yoon, Juil; Moon, Myoung-Woon; Oh, Kyu Hwan; Han, Jun Hyun

    2018-01-01

    A voidless Cu/PET substrate is fabricated by producing a superhydrophilic PET surface comprised of nanostructures with large width and height and then by Cu electroless plating. Effect of PET surface nanostructure size on the failure mechanism of the Cu/PET substrate is studied. The fabricated Cu/PET substrate exhibits a maximum peel strength of 1300 N m-1 without using an interlayer, and virtually no increase in electrical resistivity under the extreme cyclic bending condition of 1 mm curvature radius after 300 k cycles. The authors find that there is an optimum nanostructure size for the highest Cu/PET adhesion strength, and the failure mechanism of the Cu/PET flexible substrate depends on the PET surface nanostructure size. Thus, this work presents the possibility to produce flexible metal/polymer electronic substrates that have excellent interfacial adhesion between the metal and polymer and high fatigue resistance against repeated bending. Such metal/polymer substrates provides new design opportunities for wearable electronic devices that can withstand harsh environments and have extended lifetimes.

  15. Compact and mobile high resolution PET brain imager

    Science.gov (United States)

    Majewski, Stanislaw [Yorktown, VA; Proffitt, James [Newport News, VA

    2011-02-08

    A brain imager includes a compact ring-like static PET imager mounted in a helmet-like structure. When attached to a patient's head, the helmet-like brain imager maintains the relative head-to-imager geometry fixed through the whole imaging procedure. The brain imaging helmet contains radiation sensors and minimal front-end electronics. A flexible mechanical suspension/harness system supports the weight of the helmet thereby allowing for patient to have limited movements of the head during imaging scans. The compact ring-like PET imager enables very high resolution imaging of neurological brain functions, cancer, and effects of trauma using a rather simple mobile scanner with limited space needs for use and storage.

  16. Segmentation of Striatal Brain Structures from High Resolution PET Images

    Directory of Open Access Journals (Sweden)

    Ricardo J. P. C. Farinha

    2009-01-01

    Full Text Available We propose and evaluate an automatic segmentation method for extracting striatal brain structures (caudate, putamen, and ventral striatum from parametric C11-raclopride positron emission tomography (PET brain images. We focus on the images acquired using a novel brain dedicated high-resolution (HRRT PET scanner. The segmentation method first extracts the striatum using a deformable surface model and then divides the striatum into its substructures based on a graph partitioning algorithm. The weighted kernel k-means algorithm is used to partition the graph describing the voxel affinities within the striatum into the desired number of clusters. The method was experimentally validated with synthetic and real image data. The experiments showed that our method was able to automatically extract caudate, ventral striatum, and putamen from the images. Moreover, the putamen could be subdivided into anterior and posterior parts. An automatic method for the extraction of striatal structures from high-resolution PET images allows for inexpensive and reproducible extraction of the quantitative information from these images necessary in brain research and drug development.

  17. Dimensioning of a solar water heater made from PET bottles; Dimensionamento de um aquecedor solar de agua feito com garrafas PET

    Energy Technology Data Exchange (ETDEWEB)

    Bertoleti, Pedro Henrique Fonseca; Souza, Teofilo Miguel de [Universidade Estadual Paulista (UNESP), Guaratingueta, SP (Brazil). Centro de Energias Renovaveis

    2008-07-01

    This document show the solar water heater made of PET bottles, a simple-construction solar water heater that try to give us two important solutions, water heating using solar energy and reutilization of the PET bottles left in the nature. Also, it will be showed how to do the dimensioning of it. Based on the showed dimensioning a application / software is developed and after that simulations are made using the application to provide how is the economy if it's used this kind of solar water heater and their environmental contribution by reutilization of the PET bottles abandoned in the nature. For example, in a common home the economy is about 45% of the electricity bill considering that the warmed water is used just to take a shower. So, the conclusion is: the solar water heater made by PET bottles is a very relevant equipment to the use of the solar energy, to useful applications and environmental contribution. (author)

  18. Hybrid PET/MRI imaging in healthy unsedated newborn infants with quantitative rCBF measurements using 15O-water PET

    DEFF Research Database (Denmark)

    Andersen, Julie B; Lindberg, Ulrich; Olesen, Oline V

    2018-01-01

    .36, significantly higher than previous ASL data. The rCBF ASL measurements were all unsuccessful primarily owing to subject movement. In this study, we demonstrated for the first time, a minimally invasive PET/MRI method using low activity 15O-water PET for quantitative rCBF assessment in unsedated healthy newborn...

  19. Highly improved operation of monolithic BGO-PET blocks

    Science.gov (United States)

    Gonzalez-Montoro, A.; Sanchez, F.; Majewski, S.; Zanettini, S.; Benlloch, J. M.; Gonzalez, A. J.

    2017-11-01

    In PET scanners both scintillation crystals and photosensors are key components defining the system's performance and cost. Original PET systems used BGO or NaI(Tl) scintillators but achieved limited performance due to its slow decay and relatively low light output. Moreover, NaI(Tl) has low stopping power for 511 keV annihilation photons. In this study we report the possibility to reintroduce BGO crystals, and in particular in the form of monolithic blocks, especially suitable for low-dose large-size PET scanners, offering significantly improved sensitivity at a highly reduced cost compared to LYSO type fast scintillators. We have studied the performance of a monolithic BGO block as large as 50 × 50 × 15 mm3 with black-painted lateral walls to reduce lights spread, enabling accurate photon depth of interaction (DOI) measurements. A directional optical layer, called retro-reflector, was coupled to the entrance face bouncing back the scintillation light in the direction of the emission source and, therefore, adding to the light signal while preserving the narrow light cone distribution. Four configurations namely 12 × 12 and 16 × 16 SiPM arrays (3 mm × 3 mm each) as photosensors, with or without a nanopattern treatment at the crystal exit face, have been studied. This structure consisted of a thin layer of a specific high refractive index material shaped with a periodic nanopattern, increasing the scintillation light extraction. The readout returned information for each SiPM row and column, characterizing the X-Y light distribution projections. We have studied the detector spatial resolution using collimated 22Na sources at normal incidence. The DOI resolution was evaluated using collimated gamma beams with lateral incidence. The overall best detector performance was obtained for the 16× 16 SiPM array offering higher readout granularity. We have determined the spatial resolution for 3 separated DOI layers, obtaining the best results for the DOI region near to

  20. Fast and accurate water content and T2{sup ⁎} mapping in brain tumours localised with FET-PET

    Energy Technology Data Exchange (ETDEWEB)

    Oros-Peusquens, A.-M., E-mail: a.m.oros-peusquens@fz-juelich.de [Institute of Neuroscience and Medicine – 4, Research Centre Juelich, 52425 Juelich (Germany); Keil, F.; Langen, K.J.; Herzog, H.; Stoffels, G. [Institute of Neuroscience and Medicine – 4, Research Centre Juelich, 52425 Juelich (Germany); Weiss, C. [Department of Neurosurgery, University Hospital Cologne, 50924 Cologne (Germany); Shah, N.J. [Institute of Neuroscience and Medicine – 4, Research Centre Juelich, 52425 Juelich (Germany); Department of Neurology, Faculty of Medicine, JARA, RWTH Aachen University, 52074 Aachen (Germany)

    2014-01-11

    The availability of combined MR-PET scanners opens new opportunities for the characterisation of tumour environment. In this study, water content and relaxation properties of glioblastoma were investigated in five patients using advanced MRI. The region containing metabolically active tumour tissue was defined by simultaneously measured FET-PET uptake. The mean value of water content in tumour tissue – obtained noninvasively with high precision and accuracy for the first time – amounted to 84.5%, similar to the value for normal grey matter. Constancy of water content contrasted with a large variability of T2{sup ⁎} values in tumour tissue, qualitatively related to the magnetic inhomogeneity of tissue created by blood vessels and/or microbleeds. The quantitative MRI protocol takes 71/2 min of measurement time and is proposed for extended clinical use. -- Highlights: • Quantitative MRI and simultaneous FET-PET used for the study of brain tumours. • Quantitative water content and T2{sup ⁎} of the brain are reported in five glioblastoma patients. • The qMRI method achieves whole brain coverage in 71/2 min. • Water content in normal appearing tissue as well as tumour is constant within 1% for each class. • T2{sup ⁎} is highly variable within tumour volume and from patient to patient.

  1. BTES and aldehydes analysis in PET-bottled water in Lebanon.

    Science.gov (United States)

    Al Rayes, L; Saliba, C O; Ghanem, A; Randon, J

    2012-01-01

    The aim of this study was to determine benzene, toluene, ethylbenzene, styrene (BTES), formaldehyde, acetaldehyde and benzaldehyde in Lebanese polyethylene terephthalate (PET)-bottled water. Aldehydes were analysed by high-performance liquid chromatography with ultraviolet-visible detection (HPLC/UV-vis) after 2,4-dinitrophenylhydrazine (DNPH) derivatisation and solid phase extraction (SPE) concentration, whereas headspace trap gas chromatograph-flame ionisation detector (GC/FID) was used for BTES determination. Both methods were validated according to the NF XP 90-210 and showed good linearity ranging from 3 (limit of quantification [LOQ]) to 15 µg L⁻¹ for BTES and from 20 (LOQ) to 900 µg L⁻¹ for aldehydes. No quantified contamination with BTES, acetaldehyde and benzaldehyde was determined in all analysed fresh Lebanese PET-bottled waters. Formaldehyde was quantified in 3 of the 15 samples at concentrations lower than the maximum contaminant level set by the US Environmental Protection Agency and the World Health Organisation. The samples' exposure to sunlight during 5 months increases the migration of formaldehyde and acetaldehyde. Similar migration increase was observed when the samples were incubated at 40°C during 10 days.

  2. Respiratory motion compensation for simultaneous PET/MR based on highly undersampled MR data.

    Science.gov (United States)

    Rank, Christopher M; Heußer, Thorsten; Wetscherek, Andreas; Freitag, Martin T; Sedlaczek, Oliver; Schlemmer, Heinz-Peter; Kachelrieß, Marc

    2016-12-01

    Positron emission tomography (PET) of the thorax region is impaired by respiratory patient motion. To account for motion, the authors propose a new method for PET/magnetic resonance (MR) respiratory motion compensation (MoCo), which uses highly undersampled MR data with acquisition times as short as 1 min/bed. The proposed PET/MR MoCo method (4D jMoCo PET) uses radial MR data to estimate the respiratory patient motion employing MR joint motion estimation and image reconstruction with temporal median filtering. Resulting motion vector fields are incorporated into the system matrix of the PET reconstruction. The proposed approach is evaluated for the thorax region utilizing a PET/MR simulation with 1 min MR acquisition time and simultaneous PET/MR measurements of six patients with MR acquisition times of 1 and 5 min and radial undersampling factors of 11.2 and 2.2, respectively. Reconstruction results are compared to 3D PET, 4D gated PET and a standard MoCo method (4D sMoCo PET), which performs iterative image reconstruction and motion estimation sequentially. Quantitative analysis comprises the parameters SUVmean, SUVmax, full width at half-maximum/lesion volume, contrast and signal-to-noise ratio. For simulated PET data, our quantitative analysis shows that the proposed 4D jMoCo PET approach with temporal filtering achieves the best quantification accuracy of all tested reconstruction methods with a mean absolute deviation of 2.3% when compared to the ground truth. For measured PET patient data, the mean absolute deviation of 4D jMoCo PET using a 1 min MR acquisition for motion estimation is 2.1% relative to the 5 min MR acquisition. This demonstrates a robust behavior even in case of strong undersampling at MR acquisition times as short as 1 min. In contrast, 4D sMoCo PET shows considerable reduction of quantification accuracy for the 1 min MR acquisition time. Relative to 3D PET, the proposed 4D jMoCo PET approach with temporal filtering yields an average

  3. The influence of pet containers on antimony concentration in bottled drinking water

    Directory of Open Access Journals (Sweden)

    Perić-Grujić Aleksandra A.

    2010-01-01

    Full Text Available Antimony trioxide (Sb2O3 is the most frequently used catalyst in the polyethylene terephthalate (PET manufacture. As a result, antimony is incorporated into PET bottles at concentration level of 100-300 mg/kg. PET containers are used for drinking water and beverages, as well as food packaging and in the pharmaceutical industry. Thus, it is important to understand the factors that may influence the release of antimony from the catalysts into water and other products, since antimony is potentially toxic trace element. In this paper, the antimony content in nine brands of bottled mineral and spring water from Serbia, and seven brands of bottled mineral and spring water from EU countries was analyzed. The measurements were conducted using the inductively coupled plasma-mass spectrometry (ICP-MS technique. In the all examined samples the antimony concentration was bellow the maximum contaminant level of 5 μg/L prescribed by the Serbian and EU regulations. Comparison of the content of antimony in PET bottled waters with the content of antimony in water bottled commercially in glass and the natural content of antimony in pristine groundwaters, provides explicit evidence of antimony leaching from PET containers. Since waters bottled in PET have much greater concentration ratio of Sb to Pb than corresponding pristine groundwaters, it can be assumed that bottled waters cannot be used as the relavant source for the study of the natural antimony content in groundwaters. There is a clear relation between the quality of water in bottles (composition, ion strength and antimony leaching rate. Moreover, while the rate of antimony leaching is slow at temperatures below 60 oC, at the temperature range of 60-80 oC antimony release occurs and reaches maximum contaminant level rapidly. As antimony can cause both acute and chronic health problems, factors that promote the increase of antimony concentration should be avoided.

  4. High resolution PET breast imager with improved detection efficiency

    Science.gov (United States)

    Majewski, Stanislaw

    2010-06-08

    A highly efficient PET breast imager for detecting lesions in the entire breast including those located close to the patient's chest wall. The breast imager includes a ring of imaging modules surrounding the imaged breast. Each imaging module includes a slant imaging light guide inserted between a gamma radiation sensor and a photodetector. The slant light guide permits the gamma radiation sensors to be placed in close proximity to the skin of the chest wall thereby extending the sensitive region of the imager to the base of the breast. Several types of photodetectors are proposed for use in the detector modules, with compact silicon photomultipliers as the preferred choice, due to its high compactness. The geometry of the detector heads and the arrangement of the detector ring significantly reduce dead regions thereby improving detection efficiency for lesions located close to the chest wall.

  5. Powder Production From Waste Polyethylene Terephthalate (PET) Water Bottles

    Science.gov (United States)

    2014-06-01

    grinding jar was continually cooled with LN2. For cryogenic attrition at ARL, 100 g of shredded PET were milled in liquid nitrogen for 4 h in a...on the battlefield forward operating base (FOB) is investigated. Three different techniques have been employed to grind mm-size small scrap pieces of...schematic of cryogenic attrition, (b) a cryogenic attrition mill in action, (c) and the cryogenic attrition mill at ARL

  6. Effect of motion-induced PET-CT misalignment on cardiac function and myocardial blood flow measured using dynamic 15O-water PET

    DEFF Research Database (Denmark)

    Lubberink, Mark; Ebrahimi, M; Harms, Hans

    amplitude, and is thus not affected by attenuation correction errors. Hence, misalignment is hypothesized not to affect 15O-water-based MBF to any large extent, but it may affect cardiac function measures derived from 15O-water scans. The aim of the present work was to assess the effect of PET......-induced stress on a Discovery MI PET-CT scanner. Attenuation correction was based on a respiration- averaged CT scan. Images were reconstructed using TF-OSEM including PSF-recovery. PET-CT misalignment was induced by translation of the PET relative to the CT (1 cm caudal or cranial, 1 cm cranial + ventral, and 2.......5 cm cranial + 1 cm ventral). MBF, MBFt, PTF, CO, SV and LVEF were calculated semi-automatically using aQuant software and values with and without misalignment were compared using correlation and Bland-Altman analysis. The original data, without misalignment, was analysed twice to assess intra...

  7. Leaching of antimony from polyethylene terephthalate (PET) bottles into mineral water.

    Science.gov (United States)

    Keresztes, Szilvia; Tatár, Eniko; Mihucz, Victor G; Virág, István; Majdik, Cornelia; Záray, Gyula

    2009-08-01

    The Sb leaching from polyethylene terephthalate (PET) package material into 10 different brands of still (non-carbonated) and sparkling (carbonated) Hungarian mineral water purchased in supermarkets was investigated by inductively coupled plasma sector field mass spectrometry (ICP-SF-MS). The Sb concentration measured in PET package materials varied between 210 and 290 mg/kg. Generally, the Sb concentration of still mineral water was lower than that of sparkling in the case of identical storage time. For modelling improper storage conditions, storage time (10-950 days), temperature (22 degrees C-70 degrees C), illumination (dark vs. 23 W daylight lamp for 116 h) as well as bottle volume (0.5, 1.0 and 1.5 L) were taken into consideration. Under certain extreme light and temperature storage conditions, the Sb concentration of some samples exceeded the concentration value of 2 ng/mL. The extent of Sb leaching from the PET recipients of different brands of mineral water can differ by even one order of magnitude in experiments conducted under the same conditions. Thus, the adequate selection of the polymer used for the production of the PET bottle for the solar water disinfection (SODIS) procedure seems to ensure low Sb levels in the water samples.

  8. Leaching of antimony from polyethylene terephthalate (PET) bottles into mineral water

    Energy Technology Data Exchange (ETDEWEB)

    Keresztes, Szilvia [Department of Analytical Chemistry, Institute of Chemistry, L. Eoetvoes University, H-1117 Budapest, Pazmany Peter setany 1/A (Hungary); Tatar, Eniko; Mihucz, Victor G. [Department of Analytical Chemistry, Institute of Chemistry, L. Eoetvoes University, H-1117 Budapest, Pazmany Peter setany 1/A (Hungary); Hungarian Satellite Institute of Trace Elements for UNESCO, H-1117 Budapest, Pazmany Peter setany 1/A (Hungary); Sino-Hungarian Joint Laboratory of Environmental Sciences and Health, H-1117 Budapest, Pazmany Peter setany 1/A (Hungary); Virag, Istvan [Department of Analytical Chemistry, Institute of Chemistry, L. Eoetvoes University, H-1117 Budapest, Pazmany Peter setany 1/A (Hungary); Majdik, Cornelia [Department of Biochemistry and Biochemical Engineering, Babes-Bolyai University, R-3400 Cluj, Str. Arany Janos 11 (Romania); Zaray, Gyula, E-mail: zaray@ludens.elte.hu [Department of Analytical Chemistry, Institute of Chemistry, L. Eoetvoes University, H-1117 Budapest, Pazmany Peter setany 1/A (Hungary); Hungarian Satellite Institute of Trace Elements for UNESCO, H-1117 Budapest, Pazmany Peter setany 1/A (Hungary); Sino-Hungarian Joint Laboratory of Environmental Sciences and Health, H-1117 Budapest, Pazmany Peter setany 1/A (Hungary)

    2009-08-01

    The Sb leaching from polyethylene terephthalate (PET) package material into 10 different brands of still (non-carbonated) and sparkling (carbonated) Hungarian mineral water purchased in supermarkets was investigated by inductively coupled plasma sector field mass spectrometry (ICP-SF-MS). The Sb concentration measured in PET package materials varied between 210 and 290 mg/kg. Generally, the Sb concentration of still mineral water was lower than that of sparkling in the case of identical storage time. For modelling improper storage conditions, storage time (10-950 days), temperature (22 {sup o}C-70 {sup o}C), illumination (dark vs. 23 W daylight lamp for 116 h) as well as bottle volume (0.5, 1.0 and 1.5 L) were taken into consideration. Under certain extreme light and temperature storage conditions, the Sb concentration of some samples exceeded the concentration value of 2 ng/mL. The extent of Sb leaching from the PET recipients of different brands of mineral water can differ by even one order of magnitude in experiments conducted under the same conditions. Thus, the adequate selection of the polymer used for the production of the PET bottle for the solar water disinfection (SODIS) procedure seems to ensure low Sb levels in the water samples.

  9. Commissioning and Characterization of a Dedicated High Resolution Breast PET Camera

    Science.gov (United States)

    2013-07-01

    mammography , MRI, and ultrasound. We will test this high-resolution PET system in the following indications: (1) resolving inconclusive screening mammograms...lesion size, contrast and 8 standard uptake value (SUV). Pilot Study II will validate the utility of 1 mm3 resolution breast-dedicated PET in 10 women with

  10. Effect of hydrogel grafting, water and surfactant wetting on the adherence of PET wound dressings.

    Science.gov (United States)

    Ning, Chenxi Coco; Logsetty, Sarvesh; Ghughare, Shivkumar; Liu, Song

    2014-09-01

    Traditional wound dressings, including cotton gauze, absorbent pads and bandages, can cause trauma and pain to wounds during dressing changes, leading to a variety of physical and psychosocial sequelae. The aim of this study was to adapt an in vitro model of adherence to evaluate the effects of various methods to theoretically reduce the adherence of wound dressings. Gelatin in liquid form was cast onto poly(ethylene terephthalate) (PET) fabric and allowed to solidify and progressively dry to simulate wound desiccation in the clinical setting. A 180° peel test of PET from the gelatin slab yielded adherence data of peeling energy. The peeling energy of PET increased with the drying time. It was possible to reduce the force by drying at 75% relative humidity (RH). After drying for 24h, either 500μL of water or surfactant solution was added onto the PET surface (16×60mm(2)). The peeling energy decreased dramatically with wetting and there was no significant difference between water and surfactant. As a long-term strategy for decreasing adherence, a thin layer of polyacrylamide (PAM) hydrogel was deposited onto PET fabric via UV irradiation. This resulted in a much lower peeling energy without severely compromising fabric flexibility. This hydrogel layer could also serve as a reservoir for bioactive and antimicrobial agents which could be sustainably released to create a microbe-free microenvironment for optimized wound healing. Copyright © 2014 Elsevier Ltd and ISBI. All rights reserved.

  11. Acetaldehyde in mineral water stored in polyethylene terephthalate (PET) bottles: Odour threshold and quantification

    NARCIS (Netherlands)

    Nijssen, B.; Kamperman, T.; Jetten, J.

    1996-01-01

    The use of PET bottles for packaging soft drinks and mineral waters is still growing world wide. The production process for these bottles is improving constantly. These improvements are focussed on bottles with better barrier properties, higher inertness and higher heat stability. One of the factors

  12. PET bottle use patterns and antimony migration into bottled water and soft drinks: the case of British and Nigerian bottles.

    Science.gov (United States)

    Tukur, Aminu; Sharp, Liz; Stern, Ben; Tizaoui, Chedly; Benkreira, Hadj

    2012-04-01

    While antimony has been reported to migrate from PET bottles into contents, reports on bottled water and soft drinks usage and PET bottle reuse patterns are currently unavailable in the literature. Bottle use conditions and patterns are important determinants of antimony migration. In this work a survey assessing the pattern of bottle use and reuse in Britain and Nigeria was undertaken. The survey findings influenced the design of laboratory experiments that assessed the migration of antimony from PET bottles into water and soft drinks. Typical storage durations for bottled contents between purchase and opening for use were 7 days or less. However storage of up to one year was reported. Bottle reuse was high and similar for the two countries with reuse durations being higher in Nigeria. The antimony concentration in 32 PET bottle materials from Britain and Nigeria were similar and ranged between 177 and 310 mg kg(-1). For 47 freshly purchased British bottled contents antimony concentration ranged between 0.03 and 6.61 μg L(-1) with only one sample exceeding the EU acceptable limit. Concentrations of Cd, Ge, Zn, Al, Be, Ti, Co and Pb were also measured. At realistic temperatures of 40 and 60 °C antimony concentration in deionised water in bottles remained below the EU acceptable limit even after 48 h exposure. The limit was exceeded for most exposures at 80 °C. Concentration of antimony in some bottled contents exceeded the EU limit after 11 months of storage at room temperature. Bottle aging and increase in bottle volume were associated with decreased migration of antimony from bottles.

  13. F-18 FDG PET in the initial evaluation of high risk melanoma

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, T.; Zerdoud, S.; Faurie, C.; Chevreau, C.; Courbon, F. [Institut Claudius Regaud, 31 - Toulouse (France)

    2008-02-15

    Introduction. - Localized melanoma is a potentially aggressive tumor. Its prognosis depends mainly on pathologic factors, namely: thickness (Breslow index), presence of ulceration and microscopic nodal metastasis. FDG PET is the modality of choice for evaluation of advanced melanoma and has proven its superiority in terms of sensitivity, specificity and accuracy compared to conventional imaging. Early stages of melanoma do not seem to benefit from PET FDG. However the value of PET FDG in staging localized high risk melanoma is yet to be determined. Patients and methods. - We have evaluated 87 patients with high risk melanoma with PET FDG. 32 patients presented with a Breslow index superior or equal to 4 mm, 21 with a Breslow index inferior to 4 mm and ulceration and 34 with a positive sentinel lymphadenectomy. PET FDG was realized after at least 6 h of fasting on a hybrid PET-CT G.E. Discovery S.T. scan for 65 of them. The rest of the patients were evaluated on a Siemens Ecat H.R. + scan. Scans were interpreted by an experimented nuclear medicine physician and were classified as positive or negative. All equivocal scans or cases for which there was discordance between the scan result and follow up were reviewed by 2 experimented nuclear medicine physicians and a consensus was reached. Results. - FDG PET was positive in seven patients, four scans were true positive and identified regional metastatic disease. No distant metastatic visceral disease was found. The three false positive scans consisted of a cyst adeno-lymphoma in one case, mediastinal and axillary uptake in the other two cases and no sign of evolution more than six months after the scan. Four patients with a negative scan showed metastatic disease in the six months following the PET scan. FDG PET had an impact on therapeutic management on two patients (2%). When evaluating FDG PET for regional disease with sentinel node biopsy as a reference, we found values of sensitivity, specificity, predictive

  14. PetIGA: A framework for high-performance isogeometric analysis

    KAUST Repository

    Dalcin, L.

    2016-05-25

    We present PetIGA, a code framework to approximate the solution of partial differential equations using isogeometric analysis. PetIGA can be used to assemble matrices and vectors which come from a Galerkin weak form, discretized with Non-Uniform Rational B-spline basis functions. We base our framework on PETSc, a high-performance library for the scalable solution of partial differential equations, which simplifies the development of large-scale scientific codes, provides a rich environment for prototyping, and separates parallelism from algorithm choice. We describe the implementation of PetIGA, and exemplify its use by solving a model nonlinear problem. To illustrate the robustness and flexibility of PetIGA, we solve some challenging nonlinear partial differential equations that include problems in both solid and fluid mechanics. We show strong scaling results on up to 40964096 cores, which confirm the suitability of PetIGA for large scale simulations.

  15. The photocatalytic enhancement of acrylic and PET solar water disinfection (SODIS) bottles.

    Science.gov (United States)

    Carey, J M; Perez, T M; Arsiaga, E G; Loetscher, L H; Boyd, J E

    2011-01-01

    The solar water disinfection method (SODIS) was modified by the addition of a photocatalytic layer of titania on the interior surface of polyethylene terephthalate (PET) and acrylic bottles. Titania was solvent deposited on the interior of commercially available PET bottles, as well as bottles that were constructed from acrylic. Uncoated and titania-coated acrylic bottles removed 3,000,000-5,000,000 colony forming units per milliliter of K12 E. coli from 670 mL of contaminated water in 40 min of solar irradiance. After five hours of sunlight exposure, the concentration of 10 ppm methyl orange (a representative organic water contaminant), was reduced by 61% using the titania-coated acrylic bottles. The concentration of 87 ppb microcystin-LR (a representative algal toxin) was reduced by 70% after 7 hours of sunlight exposure in the titania-coated acrylic bottles. Acrylic is an effective alternative to PET for use in the SODIS method due to its greater UV transparency. The addition of titania to PET and acrylic bottles confers the ability to remove chemical contaminants in addition to inactivating microbiological contaminants.

  16. PET and Recycling

    OpenAIRE

    Funda Sevencan; Songul A. Vaizoglu

    2007-01-01

    This review aims to clarify the need of decreasing the environmental effects caused by human and draw attention to the increasing environmental effects of plastics wastes. Plastics consist of organic molecules with high density molecules or polymers. Main resources of plastics are the residue of oil rafineries. Several advantages of plastics, have increased the usage continuously. Polyethylene Terephthalate (PET) is the most commonly used plastics. PET is used to protect food, drinking water,...

  17. Determination of contact angle hysteresis of water microdroplets evaporating on hydrolyzed PET foils

    Directory of Open Access Journals (Sweden)

    Martin Nagy

    2013-12-01

    Full Text Available Moderately hydrophobic surfaces of PET foils were gradually hydrophilized by their immersion in NaOH solutions of increasing concentration. Then, the contact angle and geometric factors of microliter water drops, deposited on these polymer surfaces, were automatically monitored as a function of evaporation time. Three stages have been identified from the evaporation course of water droplets, allowing us to determine the advancing and receding contact angle and thus their difference (hysteresis.

  18. THE ANALYSIS OF THE THREAT OF REUSING PET BOTTLES FOR THE STORAGE OF DRINKING WATER

    Directory of Open Access Journals (Sweden)

    Manuilov A. M.

    2017-12-01

    Full Text Available Introduction. According to a sociological survey of about 86% of Kharkiv (Ukraine residents reuse PET bottles for a drinking water storing. This type of reuse of PET bottles isn't safe and the results of numerous research unequivocally confirm this assertion. The largest hazard of plastic bottles reuse for drinking water storage is biological film on the internally surface of bottle. This biofilm may contain pathogenic microorganisms which can migrate from biofilm to fresh water. Human, who drinking contaminated water, may drink microorganisms in common with this water. It's very dangerous, because the numerous strains of pathogens may migration in water and infect from gastric-bowel tract to the humans. Scientists from National technical university "Kharkiv polytechnic institute" in common with experts from Mechnikov institute of microbiology and immunology explored this problem and devised the apparatus, which can destroy a biofilm on polymer or another surface. Materials & Methods. The tested apparatus was the electrical device consisting of a block with electrodes, an electronic control, a water pump and a sprinkler for spraying the disinfectant. The electrode was made of 925˚ silver (sterling silver. Water for the preparation of a disinfectant was tap water and wasn't treated additionally. The sprinkler for spraying the disinfectant was placed in the neck of the infected bottle. Disinfectant solution was sprayed inside the bottle for 4 seconds. The water pressure was about 1.5 atmospheres. After that, the sprinkler was removed and the disinfectant was drained. A smear for microbiological composition was taken from three parts of the bottle - the neck, the middle part and the bottom. Growth of microorganisms and their detections was fixed by classic microbiological methods. Results & Discussion. In the article the scheme of the most probable and widespread way of infection of PET-bottles by pathogens and the way of minimization of this

  19. Enhancing hydrophilicity and water permeability of PET track-etched membranes by advanced oxidation process

    Science.gov (United States)

    Korolkov, Ilya V.; Mashentseva, Anastassiya A.; Güven, Olgun; Zdorovets, Maxim V.; Taltenov, Abzal A.

    2015-12-01

    In this study we present results on the application of advanced oxidation systems for effective and non-toxic oxidation of poly(ethylene terephthalate) track-etched membranes (PET TeMs) to improve their wettability and water transport properties. Two oxidizing systems: H2O2 under UV irradiation (H2O2/UV) and Fenton system under visible light (Fenton/H2O2/Vis) were compared. The surface of functionalized PET TeMs was characterized by using colorimetric assay, contact angle measurements and X-ray photoelectron spectroscopy (XPS). Results clearly showed that water permeability of PET TeMs treated with H2O2/UV was improved by 28 ± 5% compared with etched-only membrane, the same parameter was found to increase by 13 ± 4% in the case of Fenton/H2O2/Vis treatment. The proposed oxidation technique is very simple, environment friendly and not requiring special equipment or expensive chemicals. The surface hydrophilicity of the membranes stored for 360 days in air between paper sheets was analyzed by contact angle test, colorimetric assay to measure concentration of carboxylic groups on the surface with toluidine blue and XPS analysis. The hydrophilic properties of oxidized PET TeMs were found to be stable for a long period of time.

  20. A High Resolution Clinical PET with Breast and Whole Body Transfigurations

    Science.gov (United States)

    2006-08-01

    continues to be difficult, whether the density is a result of fibrocystic diseases or young age. Accurate detection of very small breast tumors (2...DAMD17-02-1-0461 TITLE: A High Resolution Clinical PET with Breast and Whole Body Transfigurations PRINCIPAL INVESTIGATOR: Wai-Hoi...SUBTITLE 5a. CONTRACT NUMBER A High Resolution Clinical PET with Breast and Whole Body Transfigurations 5b. GRANT NUMBER DAMD17-02-1-0461

  1. Improvement of algorithm for quantification of regional myocardial blood flow using 15O-water with PET.

    Science.gov (United States)

    Katoh, Chietsugu; Morita, Koichi; Shiga, Tohru; Kubo, Naoki; Nakada, Kunihiro; Tamaki, Nagara

    2004-11-01

    Va on the MBF value with the new method. We have developed a technique for an automated, simplified, and stable algorithm to quantify rMBF. This software is considered to be practical for clinical use in myocardial PET studies using (15)O-water with a high reproducibility and a short processing time.

  2. High Resolution PET Imaging Probe for the Detection, Molecular Characterization and Treatment Monitoring of Prostate Cancer

    Science.gov (United States)

    2012-07-01

    for testing predictions of high-resolution PET performance and a full 3D volume PET algorithm based on a list-mode maximum likelihood formulation . A...feature of the 2D formulation is that it can asymptotically achieve the limiting noise level at any reconstructed spatial resolution (although...four 128-channel VATA GP7 ASICs (Gamma- Medica Ideas, Northridge, CA, USA). Each channel of the ASIC has a fast (150 ns) shaper and leading-edge

  3. {sup 18}F-FDG PET of the hands with a dedicated high-resolution PEM system (arthro-PET): correlation with PET/CT, radiography and clinical parameters

    Energy Technology Data Exchange (ETDEWEB)

    Mhlanga, Joyce C.; Lodge, Martin [Johns Hopkins University School of Medicine, Division of Nuclear Medicine, The Russell H. Morgan Department of Radiology and Radiological Sciences, Baltimore, MD (United States); Carrino, John A. [Johns Hopkins University School of Medicine, Division of Musculoskeletal Radiology, The Russell H. Morgan Department of Radiology and Radiological Sciences, Baltimore, MD (United States); Wang, Hao [Johns Hopkins University School of Medicine, Department of Oncology Biostatistics Division, Baltimore, MD (United States); Wahl, Richard L. [Johns Hopkins University School of Medicine, Division of Nuclear Medicine, The Russell H. Morgan Department of Radiology and Radiological Sciences, Baltimore, MD (United States); Johns Hopkins University Hospitals, Division of Nuclear Medicine, Baltimore, MD (United States)

    2014-12-15

    The aim of this study was to prospectively determine the feasibility and compare the novel use of a positron emission mammography (PEM) scanner with standard PET/CT for evaluating hand osteoarthritis (OA) with {sup 18}F-FDG. Institutional review board approval and written informed consent were obtained for this HIPAA-compliant prospective study in which 14 adults referred for oncological {sup 18}F-FDG PET/CT underwent dedicated hand PET/CT followed by arthro-PET using the PEM device. Hand radiographs were obtained and scored for the presence and severity of OA. Summed qualitative and quantitative joint glycolytic scores for each modality were compared with the findings on plain radiography and clinical features. Eight patients with clinical and/or radiographic evidence of OA comprised the OA group (mean age 73 ± 7.7 years). Six patients served as the control group (53.7 ± 9.3 years). Arthro-PET quantitative and qualitative joint glycolytic scores were highly correlated with PET/CT findings in the OA patients (r = 0.86. p = 0.007; r = 0.94, p = 0.001). Qualitative arthro-PET and PET/CT joint scores were significantly higher in the OA patients than in controls (38.7 ± 6.6 vs. 32.2 ± 0.4, p = 0.02; 37.5 ± 5.4 vs. 32.2 ± 0.4, p = 0.03, respectively). Quantitative arthro-PET and PET/CT maximum SUV-lean joint scores were higher in the OA patients, although they did not reach statistical significance (20.8 ± 4.2 vs. 18 ± 1.8, p = 0.13; 22.8 ± 5.38 vs. 20.1 ± 1.54, p= 0.21). By definition, OA patients had higher radiographic joint scores than controls (30.9 ± 31.3 vs. 0, p = 0.03). Hand imaging using a small field of view PEM system (arthro-PET) with FDG is feasible, performing comparably to PET/CT in assessing metabolic joint activity. Arthro-PET and PET/CT showed higher joint FDG uptake in OA. Further exploration of arthro-PET in arthritis management is warranted. (orig.)

  4. Development of high shrinkage polyethylene terephthalate (PET) shape memory polymer tendons for concrete crack closure

    Science.gov (United States)

    Teall, Oliver; Pilegis, Martins; Sweeney, John; Gough, Tim; Thompson, Glen; Jefferson, Anthony; Lark, Robert; Gardner, Diane

    2017-04-01

    The shrinkage force exerted by restrained shape memory polymers (SMPs) can potentially be used to close cracks in structural concrete. This paper describes the physical processing and experimental work undertaken to develop high shrinkage die-drawn polyethylene terephthalate (PET) SMP tendons for use within a crack closure system. The extrusion and die-drawing procedure used to manufacture a series of PET tendon samples is described. The results from a set of restrained shrinkage tests, undertaken at differing activation temperatures, are also presented along with the mechanical properties of the most promising samples. The stress developed within the tendons is found to be related to the activation temperature, the cross-sectional area and to the draw rate used during manufacture. Comparisons with commercially-available PET strip samples used in previous research are made, demonstrating an increase in restrained shrinkage stress by a factor of two for manufactured PET filament samples.

  5. An evaluation of the migration of antimony from polyethylene terephthalate (PET) plastic used for bottled drinking water

    Energy Technology Data Exchange (ETDEWEB)

    Chapa-Martínez, C.A.; Hinojosa-Reyes, L.; Hernández-Ramírez, A.; Ruiz-Ruiz, E.; Maya-Treviño, L.; Guzmán-Mar, J.L., E-mail: jorge.guzmanmr@uanl.edu.mx

    2016-09-15

    The leaching of antimony (Sb) from polyethylene terephthalate (PET) bottling material was assessed in twelve brands of bottled water purchased in Mexican supermarkets by atomic fluorescence spectrometry with a hydride generation system (HG-AFS). Dowex® 1X8-100 ion-exchange resin was used to preconcentrate trace amounts of Sb in water samples. Migration experiments from the PET bottle material were performed in water according to the following storage conditions: 1) temperature (25 and 75 °C), 2) pH (3 and 7) and 3) exposure time (5 and 15 days), using ultrapure water as a simulant for liquid foods. The test conditions were studied by a 2{sup 3} factorial experimental design. The Sb concentration measured in the PET packaging materials varied between 73.0 and 111.3 mg/kg. The Sb concentration (0.28–2.30 μg/L) in all of the PET bottled drinking water samples examined at the initial stage of the study was below the maximum contaminant level of 5 μg/L prescribed by European Union (EU) regulations. The parameters studied (pH, temperature, and storage time) significantly affected the release of Sb, with temperature having the highest positive significant effect within the studied experimental domain. The highest Sb concentration leached from PET containers was in water samples at pH 7 stored at 75 °C for a period of 5 days. The extent of Sb leaching from the PET ingredients for different brands of drinking water can differ by as much as one order of magnitude in experiments conducted under the worst-case conditions. The chronic daily intake (CDI) caused by the release of Sb in one brand exceeded the Environmental Protection Agency (USEPA) regulated CDI value of 400 ng/kg/day, with values of 514.3 and 566.2 ng/kg/day for adults and children. Thus, the appropriate selection of the polymer used for the production of PET bottles seems to ensure low Sb levels in water samples. - Highlights: • The PET safety due to the release of Sb was evaluated in Mexican water PET

  6. Optimization of fixed titanium dioxide film on PET bottles and visual indicator for water disinfection

    Science.gov (United States)

    Heredia-Munoz, Manuel Antonio

    Water is perhaps the most important resource that sustains human life. According to the World Health Organization (WHO), almost two billion people do not have access to the required water that is needed to satisfy their daily needs and one billion do not have access to clean sources of water for consumption, most of them living in isolated and poor areas around the globe. Poor quality water increases the risk of cholera, typhoid fever and dysentery, and other water-borne illness making this problem a real crisis that humankind is facing. Several water disinfection technologies have been proposed as solutions for this problem. Solar water disinfection using TiO2 coated PET bottles was the alternative that is studied in this work. This technology does not only inactivate bacteria but also disintegrates organic chemicals that can be present in water. The objectives of this work address the optimization of the TiO 2 coated PET bottles technologies. The improvement on the bottle coating process, using two coats of 10% W/V of TiO2 in a solution of vinegar and sodium bicarbonate to form the TiO2 film, the use of a different indigo carmine (1.25 X 10-1mg/pill) concentration in the pill indicator of contamination, the increase of the disinfection rate through shaking the bottles, degradation under intermittent UV radiation and the effect of bottle size on photocatalytic water disinfection were among the most important findings. A new mathematical model that describes better photocatalytic water disinfection in TiO2 coated bottles and simulates water disinfection under different working conditions was another important achievement. These results can now be used to design a strategy for disseminating this technology in areas where it is required and, in that way, generate the greatest positive impact on the people needing safe drinking water.

  7. Giardia & Pets

    Science.gov (United States)

    ... and disinfect my home after my dog or cat is diagnosed with Giardia infection? Clean and disinfect potentially contaminated items (toys, water bowls and food bowls, pet bedding, floors, dog crates, linens, towels, ...

  8. High Dose MicroCT Does Not Contribute Toward Improved MicroPET/CT Image Quantitative Accuracy and Can Limit Longitudinal Scanning of Small Animals

    Directory of Open Access Journals (Sweden)

    Wendy A. McDougald

    2017-10-01

    Full Text Available Obtaining accurate quantitative measurements in preclinical Positron Emission Tomography/Computed Tomography (PET/CT imaging is of paramount importance in biomedical research and helps supporting efficient translation of preclinical results to the clinic. The purpose of this study was two-fold: (1 to investigate the effects of different CT acquisition protocols on PET/CT image quality and data quantification; and (2 to evaluate the absorbed dose associated with varying CT parameters.Methods: An air/water quality control CT phantom, tissue equivalent material phantom, an in-house 3D printed phantom and an image quality PET/CT phantom were imaged using a Mediso nanoPET/CT scanner. Collected data was analyzed using PMOD software, VivoQuant software and National Electric Manufactures Association (NEMA software implemented by Mediso. Measured Hounsfield Unit (HU in collected CT images were compared to the known HU values and image noise was quantified. PET recovery coefficients (RC, uniformity and quantitative bias were also measured.Results: Only less than 2 and 1% of CT acquisition protocols yielded water HU values < −80 and air HU values < −840, respectively. Four out of 11 CT protocols resulted in more than 100 mGy absorbed dose. Different CT protocols did not impact PET uniformity and RC, and resulted in <4% overall bias relative to expected radioactive concentration.Conclusion: Preclinical CT protocols with increased exposure times can result in high absorbed doses to the small animals. These should be avoided, as they do not contributed toward improved microPET/CT image quantitative accuracy and could limit longitudinal scanning of small animals.

  9. 82Rb Cardiac PET in patients with known ischemic heart disease – a direct comparison with 15O-water Cardiac PET

    DEFF Research Database (Denmark)

    Hoff, Camilla Molich; Tolbod, Lars Poulsen; Harms, Hans

    2017-01-01

    Objectives Due to incomplete extraction, corrections are required when using 82Rb for absolute MBF measurements. Previous studies have established these corrections based on healthy subjects, however, the performance in patients with pathologically reduced MBF has only been studied in few...... individuals. In this study, we compared 82Rb cardiac PET with the non-invasive gold standard for absolute blood flow quantification, 15O-water, in patients with known ischemic heart disease (IHD). Methods Thirty-nine patients with known IHD referred to 82Rb PET were included in the study. Each patient...... for both tracers and the extraction correction by Lortie et al for 82Rb. Comparisons included 1) correlation of absolute MBF for 82Rb versus 15O-water, 2) standard clinical practice for 82Rb using assessment of static, gated and dynamic scans by 2 experienced physicians (consensus), 3) in-house established...

  10. The motivations and methodology for high-throughput PET imaging of small animals in cancer research

    Energy Technology Data Exchange (ETDEWEB)

    Aide, Nicolas [Francois Baclesse Cancer Centre, Nuclear Medicine Department, Caen Cedex (France); Caen University, BioTICLA team, EA 4656, IFR 146, Caen (France); Visser, Eric P. [Radboud University Nijmegen Medical Center, Nuclear Medicine Department, Nijmegen (Netherlands); Lheureux, Stephanie [Caen University, BioTICLA team, EA 4656, IFR 146, Caen (France); Francois Baclesse Cancer Centre, Clinical Research Unit, Caen (France); Heutte, Natacha [Francois Baclesse Cancer Centre, Clinical Research Unit, Caen (France); Szanda, Istvan [King' s College London, Division of Imaging Sciences and Biomedical Engineering, London (United Kingdom); Hicks, Rodney J. [Peter MacCallum Cancer Centre, Centre for Molecular Imaging, East Melbourne (Australia)

    2012-09-15

    Over the last decade, small-animal PET imaging has become a vital platform technology in cancer research. With the development of molecularly targeted therapies and drug combinations requiring evaluation of different schedules, the number of animals to be imaged within a PET experiment has increased. This paper describes experimental design requirements to reach statistical significance, based on the expected change in tracer uptake in treated animals as compared to the control group, the number of groups that will be imaged, and the expected intra-animal variability for a given tracer. We also review how high-throughput studies can be performed in dedicated small-animal PET, high-resolution clinical PET systems and planar positron imaging systems by imaging more than one animal simultaneously. Customized beds designed to image more than one animal in large-bore small-animal PET scanners are described. Physics issues related to the presence of several rodents within the field of view (i.e. deterioration of spatial resolution and sensitivity as the radial and the axial offsets increase, respectively, as well as a larger effect of attenuation and the number of scatter events), which can be assessed by using the NEMA NU 4 image quality phantom, are detailed. (orig.)

  11. The motivations and methodology for high-throughput PET imaging of small animals in cancer research.

    Science.gov (United States)

    Aide, Nicolas; Visser, Eric P; Lheureux, Stéphanie; Heutte, Natacha; Szanda, Istvan; Hicks, Rodney J

    2012-09-01

    Over the last decade, small-animal PET imaging has become a vital platform technology in cancer research. With the development of molecularly targeted therapies and drug combinations requiring evaluation of different schedules, the number of animals to be imaged within a PET experiment has increased. This paper describes experimental design requirements to reach statistical significance, based on the expected change in tracer uptake in treated animals as compared to the control group, the number of groups that will be imaged, and the expected intra-animal variability for a given tracer. We also review how high-throughput studies can be performed in dedicated small-animal PET, high-resolution clinical PET systems and planar positron imaging systems by imaging more than one animal simultaneously. Customized beds designed to image more than one animal in large-bore small-animal PET scanners are described. Physics issues related to the presence of several rodents within the field of view (i.e. deterioration of spatial resolution and sensitivity as the radial and the axial offsets increase, respectively, as well as a larger effect of attenuation and the number of scatter events), which can be assessed by using the NEMA NU 4 image quality phantom, are detailed.

  12. A comparison of high dose Ga-67 SPECT and FDG PET imaging in malignant melanoma

    Energy Technology Data Exchange (ETDEWEB)

    Kaliff, V.; Hicks, R.J.; Binns, D.S.; Henderson, M.A.; Ainslie, J.; Jenner, D.A. [Peter McCallum Cancer Institute, Melbourne, VIC (Australia)

    1998-06-01

    Full text: Ga-67 imaging for tumour localisation lost favour in the 1970`s. With improvement in technology and use of higher doses, it has now found an important role in lymphoma. A similar phenomenon may be possible in the staging of melanoma. This study therefore compares high dose (370 MBq) Ga-67 imaging using a day 5 and 7 whole-body and comprehensive SPECT protocol, with (100 MBq) F-18 fluorodeoxyglucose (FDG) imaging using positron emission tomography (PET): a technique recently shown to be highly accurate in this condition. 85 patients; 46 males, mean age 52+17 yrs: range 22-83 yrs, underwent both studies within 9{+-}16 days (max-91 days). Scans were judged as positive (+ve), negative (-ve) or equivocal (EQ) for local, regional and distant disease. Clinical follow-up resolved discordant scan findings. PET and Ga-67 results were concordant in 61 (70%) patients (19 with +ve, 37 -ve and 5 EQ scans). None of the 9 ps with one EQ and one eye scan had disease on follow-up. Follow-up was available in 4/5 patients with discordantly +ve (3 patients) or more extensive Ga-67 abnormality: 3 patients had disease confirmed, 1 patient false +ve (asymmetric lung hilum). Follow-up was available in 9/10 patients with discordantly +ve (3 patients) or more extensive PET abnormality: 4 patients had confirmed disease, l pt false +ve (bladder diverticulum). A further 4 patients had second primaries (2 rectal carcinomas, 1 plasmacytoma, 1 basal cell carcinoma). High dose Ga-67 scanning incorporating SPECT appears to be a reasonable alternative to FDG PET for screening patients with melanoma. In this series PET`s main advantages were in the detection of other occult tumours, greater patient convenience and lower radiation dosimetry.

  13. Novel Geometrical Concept of a High Performance Brain PET Scanner Principle, Design and Performance Estimates

    CERN Document Server

    Séguinot, Jacques; Chesi, Enrico Guido; Joram, C; Mathot, S; Weilhammer, P; Chamizo-Llatas, M; Correia, J G; Ribeiro da Silva, M; Garibaldi, F; De Leo, R; Nappi, E; Corsi, F; Dragone, A; Schoenahl, F; Zaidi, H

    2006-01-01

    We present the principle, a possible implementation and performance estimates of a novel geometrical concept for a high resolution positron emission tomograph. The concept, which can for example be implemented in a brain PET device, promisses to lead to an essentially parallax free 3D image reconstruction with excellent spatial resolution and constrast, uniform over the complete field of view. The key components are matrices of long axially oriented scintillator crystals which are read out at both extremities by segmented Hybrid Photon Detectors. We discuss the relevant design considerations for a 3D axial PET camera module, motivate parameter and material choices, and estimate its performance in terms of spatial and energy resolution. We support these estimates by Monte Carlo simulations and in some cases by first experimental results. From the performance of a camera module, we extrapolate to the reconstruction resolution of a 3D axial PET scanner in a semi-analytical way and compare it to an existing state...

  14. Markerless 3D Head Tracking for Motion Correction in High Resolution PET Brain Imaging

    DEFF Research Database (Denmark)

    Olesen, Oline Vinter

    relying on markers. Data-driven motion correction is problematic due to the physiological dynamics. Marker-based tracking is potentially unreliable, and it is extremely hard to validate when the tracking information is correct. The motion estimation is essential for proper motion correction of the PET...... images. Incorrect motion correction can in the worst cases result in wrong diagnosis or treatment. The evolution of a markerless custom-made structured light 3D surface tracking system is presented. The system is targeted at state-of-the-art high resolution dedicated brain PET scanners with a resolution...

  15. High-resolution PET [Positron Emission Tomography] for Medical Science Studies

    Science.gov (United States)

    Budinger, T. F.; Derenzo, S. E.; Huesman, R. H.; Jagust, W. J.; Valk, P. E.

    1989-09-01

    One of the unexpected fruits of basic physics research and the computer revolution is the noninvasive imaging power available to today's physician. Technologies that were strictly the province of research scientists only a decade or two ago now serve as the foundations for such standard diagnostic tools as x-ray computer tomography (CT), magnetic resonance imaging (MRI), magnetic resonance spectroscopy (MRS), ultrasound, single photon emission computed tomography (SPECT), and positron emission tomography (PET). Furthermore, prompted by the needs of both the practicing physician and the clinical researcher, efforts to improve these technologies continue. This booklet endeavors to describe the advantages of achieving high resolution in PET imaging.

  16. Development of dose delivery verification by PET imaging of photonuclear reactions following high energy photon therapy

    Science.gov (United States)

    Janek, S.; Svensson, R.; Jonsson, C.; Brahme, A.

    2006-11-01

    A method for dose delivery monitoring after high energy photon therapy has been investigated based on positron emission tomography (PET). The technique is based on the activation of body tissues by high energy bremsstrahlung beams, preferably with energies well above 20 MeV, resulting primarily in 11C and 15O but also 13N, all positron-emitting radionuclides produced by photoneutron reactions in the nuclei of 12C, 16O and 14N. A PMMA phantom and animal tissue, a frozen hind leg of a pig, were irradiated to 10 Gy and the induced positron activity distributions were measured off-line in a PET camera a couple of minutes after irradiation. The accelerator used was a Racetrack Microtron at the Karolinska University Hospital using 50 MV scanned photon beams. From photonuclear cross-section data integrated over the 50 MV photon fluence spectrum the predicted PET signal was calculated and compared with experimental measurements. Since measured PET images change with time post irradiation, as a result of the different decay times of the radionuclides, the signals from activated 12C, 16O and 14N within the irradiated volume could be separated from each other. Most information is obtained from the carbon and oxygen radionuclides which are the most abundant elements in soft tissue. The predicted and measured overall positron activities are almost equal (-3%) while the predicted activity originating from nitrogen is overestimated by almost a factor of two, possibly due to experimental noise. Based on the results obtained in this first feasibility study the great value of a combined radiotherapy-PET-CT unit is indicated in order to fully exploit the high activity signal from oxygen immediately after treatment and to avoid patient repositioning. With an RT-PET-CT unit a high signal could be collected even at a dose level of 2 Gy and the acquisition time for the PET could be reduced considerably. Real patient dose delivery verification by means of PET imaging seems to be

  17. Image derived input functions for dynamic High Resolution Research Tomograph PET brain studies

    NARCIS (Netherlands)

    Mourik, J.E.M.; van Velden, F.H.P.; Lubberink, J.M.; Kloet, R.W.; van Berckel, B.N.M.; Lammertsma, A.A.; Boellaard, R.

    2008-01-01

    The High Resolution Research Tomograph (HRRT) is a dedicated human brain positron emission tomography (PET) scanner. The aim of the present study was to validate the use of image derived input functions (IDIF) as an alternative for arterial sampling for HRRT human brain studies. To this end, IDIFs

  18. {sup 90}Y -PET imaging: Exploring limitations and accuracy under conditions of low counts and high random fraction

    Energy Technology Data Exchange (ETDEWEB)

    Carlier, Thomas, E-mail: thomas.carlier@chu-nantes.fr [Department of Nuclear Medicine, University Hospital of Nantes, Place Alexis Ricordeau, Nantes 44093, France and CRCNA–UMR 892 INSERM 6299 CNRS, 8 quai Moncousu BP 70721, Nantes 44007 (France); Willowson, Kathy P. [Institute of Medical Physics, University of Sydney, Camperdown, New South Wales 2006 (Australia); Fourkal, Eugene [Department of Radiation Oncology, Allegheny General Hospital, Pittsburgh, Pennsylvania 15212 (United States); Bailey, Dale L. [Faculty of Health Sciences, University of Sydney, Lidcombe 2141, Australia and Department of Nuclear Medicine, Royal North Shore Hospital, St Leonards, New South Wales 2065 (Australia); Doss, Mohan [Department of Diagnostic Imaging, Fox Chase Cancer Center, Philadelphia, Pennsylvania 19111 (United States); Conti, Maurizio [Siemens Healthcare Molecular Imaging, 810 Innovation Drive, Knoxville, Tennessee 37932 (United States)

    2015-07-15

    Purpose: {sup 90}Y -positron emission tomography (PET) imaging is becoming a recognized modality for postinfusion quantitative assessment following radioembolization therapy. However, the extremely low counts and high random fraction associated with {sup 90}Y -PET may significantly impair both qualitative and quantitative results. The aim of this work was to study image quality and noise level in relation to the quantification and bias performance of two types of Siemens PET scanners when imaging {sup 90}Y and to compare experimental results with clinical data from two types of commercially available {sup 90}Y microspheres. Methods: Data were acquired on both Siemens Biograph TruePoint [non-time-of-flight (TOF)] and Biograph microcomputed tomography (mCT) (TOF) PET/CT scanners. The study was conducted in three phases. The first aimed to assess quantification and bias for different reconstruction methods according to random fraction and number of true counts in the scan. The NEMA 1994 PET phantom was filled with water with one cylindrical insert left empty (air) and the other filled with a solution of {sup 90}Y . The phantom was scanned for 60 min in the PET/CT scanner every one or two days. The second phase used the NEMA 2001 PET phantom to derive noise and image quality metrics. The spheres and the background were filled with a {sup 90}Y solution in an 8:1 contrast ratio and four 30 min acquisitions were performed over a one week period. Finally, 32 patient data (8 treated with Therasphere{sup ®} and 24 with SIR-Spheres{sup ®}) were retrospectively reconstructed and activity in the whole field of view and the liver was compared to theoretical injected activity. Results: The contribution of both bremsstrahlung and LSO trues was found to be negligible, allowing data to be decay corrected to obtain correct quantification. In general, the recovered activity for all reconstruction methods was stable over the range studied, with a small bias appearing at extremely

  19. Water Quality Evaluation of PET Bottled Water by Mineral Balance in the Northeast Asian Region: A Case Study of South Korea.

    Science.gov (United States)

    Houri, Daisuke; Koo, Chung Mo

    2015-09-01

    The past few years have seen a demand for drinking water in contemporary society with a focus on safety and taste. Mineral water is now marketed as a popular commercial product and, partly due to health concerns, the production. For the study, a comparison was carried out of water samples from 9 types of polyethylene terephthalate (PET) bottled water sold in South Korea as well as from tap water in the cities of Seoul and Chuncheon. These were compared with samples of Japanese PET bottled water in order to determine shared commonalities and identify individual characteristics. To evaluate water quality objectively, we quantified the elements contained in the water samples. Samples were assessed not with the usual sensory evaluation but with the evaluation approach advocated by Hashimoto et al. which employs the Water Index of Taste and the Water Index of Health. The levels of water quality obtained were compared with the "Prerequisites for Tasty Water" and the "Standards for Tasty Water" devised for city water. The PET Bottled water varieties analyzed in this study-Seoksu, Icis, Bong Pyong, Soon Soo 100, Dong Won Saem Mul, GI JANG SOO and DIAMOND-showed the Water Index of Taste ≥ 2.0 and the Water Index of Health ≥ 5.2, which we classified as tasty/healthy water. SamDaSoo and NamiNeral can be classified as tasty water due to their values of the Water Index of Taste ≥ 2.0 and the Water Index of Health water studied here fulfills the "Water Index of Taste," "Water Index of Health," "Standard for Tasty Water" and "Prerequisites for Tasty Water" that Japanese people value for city water. We can conclude that bottled water which meets water quality requirements will be considered good-tasting by a majority of people.

  20. MR-compatibility of a high-resolution small animal PET insert operating inside a 7 T MRI

    Science.gov (United States)

    Thiessen, J. D.; Shams, E.; Stortz, G.; Schellenberg, G.; Bishop, D.; Khan, M. S.; Kozlowski, P.; Retière, F.; Sossi, V.; Thompson, C. J.; Goertzen, A. L.

    2016-11-01

    A full-ring PET insert consisting of 16 PET detector modules was designed and constructed to fit within the 114 mm diameter gradient bore of a Bruker 7 T MRI. The individual detector modules contain two silicon photomultiplier (SiPM) arrays, dual-layer offset LYSO crystal arrays, and high-definition multimedia interface (HDMI) cables for both signal and power transmission. Several different RF shielding configurations were assessed prior to construction of a fully assembled PET insert using a combination of carbon fibre and copper foil for RF shielding. MR-compatibility measurements included field mapping of the static magnetic field (B 0) and the time-varying excitation field (B 1) as well as acquisitions with multiple pulse sequences: spin echo (SE), rapid imaging with refocused echoes (RARE), fast low angle shot (FLASH) gradient echo, and echo planar imaging (EPI). B 0 field maps revealed a small degradation in the mean homogeneity (+0.1 ppm) when the PET insert was installed and operating. No significant change was observed in the B 1 field maps or the image homogeneity of various MR images, with a 9% decrease in the signal-to-noise ratio (SNR) observed only in EPI images acquired with the PET insert installed and operating. PET detector flood histograms, photopeak amplitudes, and energy resolutions were unchanged in individual PET detector modules when acquired during MRI operation. There was a small baseline shift on the PET detector signals due to the switching amplifiers used to power MRI gradient pulses. This baseline shift was observable when measured with an oscilloscope and varied as a function of the gradient duty cycle, but had no noticeable effect on the performance of the PET detector modules. Compact front-end electronics and effective RF shielding led to minimal cross-interference between the PET and MRI systems. Both PET detector and MRI performance was excellent, whether operating as a standalone system or a hybrid PET/MRI.

  1. High contrast pet imaging of GRPR expression in prostate cancer using cobalt-labeled bombesin antagonist RM26

    DEFF Research Database (Denmark)

    Mitran, Bogdan; Thisgaard, Helge; Rosenström, Ulrika

    2017-01-01

    ) and 1000 (24 h pi).The favorable biodistribution of cobalt-labeled NOTA-PEG2-RM26 translated into high contrast preclinical PET/CT (using55Co) and SPECT/CT (using57Co) images of PC-3 xenografts.The initial biological results suggest that55Co-NOTA-PEG2-RM26 is a promising tracer for PET visualization...

  2. {sup 18}F-FDG PET/CT-Negative Recurrent High-Grade Anaplastic Astrocytoma Detected by {sup 18}F-FDOPA PET-CT

    Energy Technology Data Exchange (ETDEWEB)

    Karunanithi, Sellam; Singh, Harmandeep; Sharma, Punit; Gupta, Deepak Kumar; Bal, Chandrasekhar [All India Institute of Medical Sciences, New Delhi (India)

    2013-12-15

    A 37-year-old woman with grade 3 anaplastic astrocytoma (AA) of the left frontal lobe, underwent surgical excision, chemotherapy and external beam radiation therapy in 2004. After being in remission for 5 years, recurrence was suspected clinically when she presented with seizures. The result of contrast-enhanced magnetic resonance imaging (MRI) was equivocal for recurrence and radiation necrosis (not available ). The patient was then referred for {sup 18}F-fluorodeoxyglucose ({sup 18}F-FDG) positron emission tomography-computed tomography (PET-CT), as the initial primary tumour was high grade in nature. {sup 18}F-FDG PET-CT was negative for recurrence and demonstrated only post-operative changes in the left frontal region (Fig. 1a, b, arrow). Due to strong clinical suspicion, 3,4-dihydroxy-6-{sup 18}F-fluoro-L-phenylalanine ({sup 18}F-FDOPA) PET-CT was done, 5 days after {sup 18}F-FDG PET-CT. The study revealed an {sup 18}F-FDOPA-avid mass lesion in the left frontal region (Fig. 1c, d, arrow), thereby confirming the presence of recurrent disease. The patient underwent surgical resection of the mass, and it was confirmed by histopathology as grade 3 AA. However, after a short asymptomatic period of 4 months the patient became symptomatic again. Follow-up MRI after 6 months of surgery revealed presence of ipsilateral and contralateral multifocal contrast enhancing recurrent mass lesions (Fig. 1e, f, arrow), suggesting the progression of disease. The patient was started on temozolamide but she died after 8 months' follow-up. Though MRI is routinely used in assessment of brain tumours, its ability to differentiate between treatment-induced changes and residual or recurrent tumour is limited. {sup 18}F-FDG PET was the first tracer used for assessment of brain tumours; however, it has a low tumour-to-background ratio in brain, limiting its utility. {sup 18}F-FDG uptake correlates with tumour grade, with high-grade gliomas (grades III and IV) showing higher uptake

  3. Treatment of PET nonwoven with a water vapor or carbon dioxide plasma

    NARCIS (Netherlands)

    Klomp, A.J.A.; Klomp, A.J.A.; Terlingen, J.G.A.; Terlingen, J.G.A.; Takens, G.A.J.; Takens, G.A.J.; Strikker, A.; Engbers, G.H.M.; Feijen, Jan

    2000-01-01

    Gas plasma treatment of poly(ethylene terephthalate) nonwoven (NW-PET) was used to increase the hydrophilicity of single- and multilayer NW-PET. NW-PET was treated with a pulsatile CO2 or with a pulsatile H2O glow discharge. X-ray photoelectron spectroscopy (XPS) showed significantly more oxygen

  4. Dedicated mobile high resolution prostate PET imager with an insertable transrectal probe

    Science.gov (United States)

    Majewski, Stanislaw; Proffitt, James

    2010-12-28

    A dedicated mobile PET imaging system to image the prostate and surrounding organs. The imaging system includes an outside high resolution PET imager placed close to the patient's torso and an insertable and compact transrectal probe that is placed in close proximity to the prostate and operates in conjunction with the outside imager. The two detector systems are spatially co-registered to each other. The outside imager is mounted on an open rotating gantry to provide torso-wide 3D images of the prostate and surrounding tissue and organs. The insertable probe provides closer imaging, high sensitivity, and very high resolution predominately 2D view of the prostate and immediate surroundings. The probe is operated in conjunction with the outside imager and a fast data acquisition system to provide very high resolution reconstruction of the prostate and surrounding tissue and organs.

  5. Disparity of perfusion and glucose metabolism of epileptogenic zones in temporal lobe epilepsy demonstrated by SPM/SPAM analysis on 15O water PET, [18F]FDG-PET, and [99mTc]-HMPAO SPECT.

    Science.gov (United States)

    Lee, D S; Lee, J S; Kang, K W; Jang, M J; Lee, S K; Chung, J K; Lee, M C

    2001-12-01

    To elucidate uncoupling of perfusion and metabolism and its significance in epilepsy, 15O water and 18F fluorodeoxyglucose (FDG) positron emission tomography (PET) and Tc-99m hexamethyl-propyleneamine-oxime (HMPAO) single-photon emission computed tomography (SPECT) were examined by SPM (statistical parametric mapping) and quantitation by using SPAM (statistical probabilistic anatomic map). [15O]water and [18F]FDG-PET, and [99mTc]-HMPAO SPECT were performed in 25 patients (SPECT in 17 of 25) with medial temporal lobe epilepsy. For volume of interest (VOI) count analysis, the normalized counts using VOI based on SPAM templates of PET and SPECT were compared with those of the normal controls. Perfusion or metabolism was found abnormal if the Z score was >2 for each VOI. For SPM analysis, the differences between each patient's image and a group of normal control images (t statistic for p SPAM VOI count analysis, areas of hypoperfusion were found in 13 patients in the epileptogenic temporal lobes by [15O]water PET and areas of hypometabolism in 21 patients by [18F]FDG-PET. With voxel-based SPM analysis, the epileptogenic zones were localized in 15 by [15O]water PET and in 23 patients by [18F]FDG-PET. The localization by [15O]water PET was concordant with that of [18F]FDG-PET. The areas of hypoperfusion on [15O]water PET were absent or smaller than the areas of hypometabolism on [18F]FDG-PET. Interictal [99mTc]-HMPAO SPECT revealed the hypoperfused zones in seven of 17 patients on visual assessment. SPAM VOI count and SPM analysis of [15O]water and [18F]FDG-PET and [99mTc]-HMPAO SPECT revealed that in the same patients, the areas of hypoperfusion were concordant with but smaller than the areas of hypometabolism. Discordance of perfusion and metabolic abnormalities represents an uncoupling of perfusion and metabolism in the epileptogenic zones, and this might explain the lower diagnostic accuracy of perfusion imaging in temporal lobe epilepsy.

  6. Towards a high sensitivity small animal PET system based on CZT detectors (Conference Presentation)

    Science.gov (United States)

    Abbaszadeh, Shiva; Levin, Craig

    2017-03-01

    Small animal positron emission tomography (PET) is a biological imaging technology that allows non-invasive interrogation of internal molecular and cellular processes and mechanisms of disease. New PET molecular probes with high specificity are under development to target, detect, visualize, and quantify subtle molecular and cellular processes associated with cancer, heart disease, and neurological disorders. However, the limited uptake of these targeted probes leads to significant reduction in signal. There is a need to advance the performance of small animal PET system technology to reach its full potential for molecular imaging. Our goal is to assemble a small animal PET system based on CZT detectors and to explore methods to enhance its photon sensitivity. In this work, we reconstruct an image from a phantom using a two-panel subsystem consisting of six CZT crystals in each panel. For image reconstruction, coincidence events with energy between 450 and 570 keV were included. We are developing an algorithm to improve sensitivity of the system by including multiple interaction events.

  7. A high resolution TOF-PET concept with axial geometry and digital SiPM readout

    CERN Document Server

    Casella, C; Joram, C; Schneider, T

    2014-01-01

    The axial arrangement of long scintillation crystals is a promising concept in PET instrumentation to address the need for optimized resolution and sensitivity. Individual crystal readout and arrays of wavelength shifter strips placed orthogonally to the crystals lead to a 3D-detection of the annihilations photons. A fully operational demonstrator scanner, developed by the AX-PET collaboration, proved the potential of this concept in terms of energy and spatial resolution as well as sensitivity. This paper describes a feasibility study, performed on axial prototype detector modules with 100 mm long LYSO crystals, read out by the novel digital Silicon Photomultipliers (dSiPM) from Philips. With their highly integrated readout electronics and excellent intrinsic time resolution, dSiPMs allow for compact, axial detector modules which may extend the potential of the axial PET concept by time of fl ight capabilities (TOF-PET). A coincidence time resolution of 211 ps (FWHM) was achieved in the coincidence of two ax...

  8. Improvement in clinical evaluation of PET/CT images with high resolution algorithms.

    Science.gov (United States)

    Orlandini, L C; Betti, M; Fulcheri, C; Dona, M; Fisicaro, D; Castagnoli, A

    2013-06-01

    Positron emission tomography/computed tomography (PET/CT) diagnosis relies on quality of the reconstructed images which strongly depends on the algorithms used. The aim of this work was to assess if the introduction of high resolution algorithms allows a better identification of reduced diameter lesions, leading to improved diagnosis in clinical setting. The performances of a Siemens Biograph6 True Point PET/CT used for this work were checked for both standard and high resolution algorithms. Clinical studies of thirteen patients referred for PET/CT were selected and grouped according to the metabolic tumor volume and their position in the FOV and then reconstructed with both algorithms; clinical studies were estimated in terms of geometric characteristics and uptake values (SUVmax, SUVmean) of the lesions. FWHM, spatial resolution, contrast ratio and image quality of the PET/CT scanner used for this work are in agreement with the performances declared by the manufacturers. For the clinical studies, the results obtained using TrueX algorithm showed an increase in SUVmax and SUVmean of 20% and 10% respectively for lesions with volume higher than 2 cm3 and of about 26% and 15% for smaller lesions. The enhancement of SUVmean was around 10% for in axis lesions and of about 12% for off axis lesions. For SUVmax the increase was 23% for both the positions. For small lesions TrueX algorithm led to a metabolic volume higher than with the iterative one while no significant differences were found for big lesions. The advances in 3D PET reconstruction algorithms lead to images with improved quantitative accuracy and image quality performance.

  9. An evaluation of the migration of antimony from polyethylene terephthalate (PET) plastic used for bottled drinking water.

    Science.gov (United States)

    Chapa-Martínez, C A; Hinojosa-Reyes, L; Hernández-Ramírez, A; Ruiz-Ruiz, E; Maya-Treviño, L; Guzmán-Mar, J L

    2016-09-15

    The leaching of antimony (Sb) from polyethylene terephthalate (PET) bottling material was assessed in twelve brands of bottled water purchased in Mexican supermarkets by atomic fluorescence spectrometry with a hydride generation system (HG-AFS). Dowex® 1X8-100 ion-exchange resin was used to preconcentrate trace amounts of Sb in water samples. Migration experiments from the PET bottle material were performed in water according to the following storage conditions: 1) temperature (25 and 75°C), 2) pH (3 and 7) and 3) exposure time (5 and 15days), using ultrapure water as a simulant for liquid foods. The test conditions were studied by a 2(3) factorial experimental design. The Sb concentration measured in the PET packaging materials varied between 73.0 and 111.3mg/kg. The Sb concentration (0.28-2.30μg/L) in all of the PET bottled drinking water samples examined at the initial stage of the study was below the maximum contaminant level of 5μg/L prescribed by European Union (EU) regulations. The parameters studied (pH, temperature, and storage time) significantly affected the release of Sb, with temperature having the highest positive significant effect within the studied experimental domain. The highest Sb concentration leached from PET containers was in water samples at pH7 stored at 75°C for a period of 5days. The extent of Sb leaching from the PET ingredients for different brands of drinking water can differ by as much as one order of magnitude in experiments conducted under the worst-case conditions. The chronic daily intake (CDI) caused by the release of Sb in one brand exceeded the Environmental Protection Agency (USEPA) regulated CDI value of 400ng/kg/day, with values of 514.3 and 566.2ng/kg/day for adults and children. Thus, the appropriate selection of the polymer used for the production of PET bottles seems to ensure low Sb levels in water samples. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Pet Bonding and Pet Bereavement among Adolescents.

    Science.gov (United States)

    Brown, Brenda H.; And Others

    1996-01-01

    Studied adolescent-pet bonding and bereavement following pet loss (n=55). Hypothesized that highly-bonded adolescents experience more intense grief when a pet dies than do those less bonded; degree of bonding is greater for girls than for boys; and intensity of bereavement is greater for girls than for boys. Results supported the hypotheses. (RB)

  11. High performance ZnO:Al films deposited on PET substrates using facing target sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Tingting [Solar Film Laboratory, School of Physics and Nuclear Energy Engineering, Beihang University, Beijing 100191 (China); Dong, Guobo, E-mail: wavedong@buaa.edu.cn [Solar Film Laboratory, School of Physics and Nuclear Energy Engineering, Beihang University, Beijing 100191 (China); Gao, Fangyuan; Xiao, Yu [Solar Film Laboratory, School of Physics and Nuclear Energy Engineering, Beihang University, Beijing 100191 (China); Chen, Qiang [Key Laboratory of Micro-nano Measurement-Manipulation and Physics (Ministry of Education), School of Physics and Nuclear Energy Engineering, Beihang University, Beijing 100191 (China); Diao, Xungang [Solar Film Laboratory, School of Physics and Nuclear Energy Engineering, Beihang University, Beijing 100191 (China)

    2013-10-01

    ZnO:Al (ZAO) thin films have been deposited on flexible PET substrates using a plasma damage-free facing target sputtering system at room temperature. The structure, surface morphology, electrical and optical properties were investigated as a function of working power. All the samples have a highly preferred orientation of the c-axis perpendicular to the PET substrate and have a high quality surface. With increased working power, the carrier concentration changes slightly, the mobility increases at the beginning and decreases after it reaches a maximum value, in line with electrical conductivity. The figure of merit has been significantly improved with increasing of the working power. Under the optimized condition, the lowest resistivity of 1.3 × 10{sup −3} Ω cm with a sheet resistance of 29 Ω/□ and the relative visible transmittance above 93% in the visible region were obtained.

  12. MRPC-PET: A new technique for high precision time and position measurements

    Energy Technology Data Exchange (ETDEWEB)

    Doroud, K., E-mail: kdoroud@cern.ch [World Laboratory, Geneva (Switzerland); Hatzifotiadou, D. [Sezione INFN, Bologna (Italy); Li, S. [World Laboratory, Geneva (Switzerland); Williams, M.C.S. [Sezione INFN, Bologna (Italy); Zichichi, A. [Dipartimento di Fisica dell' Universita, Bologna (Italy); PH Dept, CERN, Geneva (Switzerland); Zuyeuski, R. [World Laboratory, Geneva (Switzerland)

    2011-12-21

    The purpose of this paper is to consider a new technology for medical diagnosis: the MRPC-PET. This technology allows excellent time resolution together with 2-D position information thus providing a fundamental step in this field. The principle of this method is based on the Multigap Resistive Plate Chamber (MRPC) capable of high precision time measurements. We have previously found that the route to precise timing is differential readout (this requires matching anode and cathode strips); thus crossed strip readout schemes traditionally used for 2-D readout cannot be exploited. In this paper we consider the time difference from the two ends of the strip to provide a high precision measurement along the strip; the average time gives precise timing. The MRPC-PET thus provides a basic step in the field of medical technology: excellent time resolution together with 2-D position measurement.

  13. Use of FDG PET/CT for investigation of febrile neutropenia: evaluation in high-risk cancer patients

    Energy Technology Data Exchange (ETDEWEB)

    Guy, Stephen D.; Tramontana, Adrian R. [Western Health, Department of Infectious Diseases, Private Bag, Footscray, Victoria (Australia); University of Melbourne, Parkville, Victoria (Australia); Worth, Leon J.; Thursky, Karin A.; Slavin, Monica A. [University of Melbourne, Parkville, Victoria (Australia); Peter MacCallum Cancer Centre, Department of Infectious Diseases, Melbourne, Victoria (Australia); Lau, Eddie; Hicks, Rodney J. [University of Melbourne, Parkville, Victoria (Australia); Peter MacCallum Cancer Centre, Centre for Cancer Imaging, Melbourne, Victoria (Australia); Seymour, John F. [University of Melbourne, Parkville, Victoria (Australia); Peter MacCallum Cancer Centre, Department of Haematology, Melbourne, Victoria (Australia)

    2012-08-15

    Febrile neutropenia (FNP) is a frequent complication of cancer care and evaluation often fails to identify a cause. [{sup 18} F]FDG PET/CT has the potential to identify inflammatory and infectious foci, but its potential role as an investigation for persistent FNP has not previously been explored. The aim of this study was to prospectively evaluate the clinical utility of FDG PET/CT in patients with cancer and severe neutropenia and five or more days of persistent fever despite antibiotic therapy. Adult patients with a diagnosis of an underlying malignancy and persistent FNP (temperature {>=}38 C and neutrophil count <500 cells/{mu}l for 5 days) underwent FDG PET/CT as an adjunct to conventional evaluation and management. The study group comprised 20 patients with FNP who fulfilled the eligibility criteria and underwent FDG PET/CT in addition to conventional evaluation. The median neutrophil count on the day of the FDG PET/CT scan was 30 cells/{mu}l (range 0-730 cells/{mu}l). Conventional evaluation identified 14 distinct sites of infection, 13 (93 %) of which were also identified by FDG PET/CT, including all deep tissue infections. FDG PET/CT identified 9 additional likely infection sites, 8 of which were subsequently confirmed as ''true positives'' by further investigations. FDG PET/CT was deemed to be of 'high' clinical impact in 15 of the 20 patients (75 %). This study supports the utility of FDG PET/CT scanning in severely neutropenic patients with five or more days of fever. Further evaluation of the contribution of FDG PET/CT in the management of FNP across a range of underlying malignancies is required. (orig.)

  14. High-performance electronics for time-of-flight PET systems.

    Science.gov (United States)

    Choong, W-S; Peng, Q; Vu, C Q; Turko, B T; Moses, W W

    2013-01-01

    We have designed and built a high-performance readout electronics system for time-of-flight positron emission tomography (TOF PET) cameras. The electronics architecture is based on the electronics for a commercial whole-body PET camera (Siemens/CPS Cardinal electronics), modified to improve the timing performance. The fundamental contributions in the electronics that can limit the timing resolution include the constant fraction discriminator (CFD), which converts the analog electrical signal from the photo-detector to a digital signal whose leading edge is time-correlated with the input signal, and the time-to-digital converter (TDC), which provides a time stamp for the CFD output. Coincident events are identified by digitally comparing the values of the time stamps. In the Cardinal electronics, the front-end processing electronics are performed by an Analog subsection board, which has two application-specific integrated circuits (ASICs), each servicing a PET block detector module. The ASIC has a built-in CFD and TDC. We found that a significant degradation in the timing resolution comes from the ASIC's CFD and TDC. Therefore, we have designed and built an improved Analog subsection board that replaces the ASIC's CFD and TDC with a high-performance CFD (made with discrete components) and TDC (using the CERN high-performance TDC ASIC). The improved Analog subsection board is used in a custom single-ring LSO-based TOF PET camera. The electronics system achieves a timing resolution of 60 ps FWHM. Prototype TOF detector modules are read out with the electronics system and give coincidence timing resolutions of 259 ps FWHM and 156 ps FWHM for detector modules coupled to LSO and LaBr3 crystals respectively.

  15. Development of a novel depth of interaction PET detector using highly multiplexed G-APD cross-strip encoding

    Energy Technology Data Exchange (ETDEWEB)

    Kolb, A., E-mail: armin.kolb@med.uni-tuebingen.de; Parl, C.; Liu, C. C.; Pichler, B. J. [Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University, 72076 Tübingen (Germany); Mantlik, F. [Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University, 72076 Tübingen, Germany and Department of Empirical Inference, Max Planck Institute for Intelligent Systems, 72076 Tübingen (Germany); Lorenz, E. [Max Planck Institute for Physics, Föhringer Ring 6, 80805 München (Germany); Renker, D. [Department of Physics, Technische Universität München, 85748 Garching (Germany)

    2014-08-15

    Purpose: The aim of this study was to develop a prototype PET detector module for a combined small animal positron emission tomography and magnetic resonance imaging (PET/MRI) system. The most important factor for small animal imaging applications is the detection sensitivity of the PET camera, which can be optimized by utilizing longer scintillation crystals. At the same time, small animal PET systems must yield a high spatial resolution. The measured object is very close to the PET detector because the bore diameter of a high field animal MR scanner is limited. When used in combination with long scintillation crystals, these small-bore PET systems generate parallax errors that ultimately lead to a decreased spatial resolution. Thus, we developed a depth of interaction (DoI) encoding PET detector module that has a uniform spatial resolution across the whole field of view (FOV), high detection sensitivity, compactness, and insensitivity to magnetic fields. Methods: The approach was based on Geiger mode avalanche photodiode (G-APD) detectors with cross-strip encoding. The number of readout channels was reduced by a factor of 36 for the chosen block elements. Two 12 × 2 G-APD strip arrays (25μm cells) were placed perpendicular on each face of a 12 × 12 lutetium oxyorthosilicate crystal block with a crystal size of 1.55 × 1.55 × 20 mm. The strip arrays were multiplexed into two channels and used to calculate the x, y coordinates for each array and the deposited energy. The DoI was measured in step sizes of 1.8 mm by a collimated {sup 18}F source. The coincident resolved time (CRT) was analyzed at all DoI positions by acquiring the waveform for each event and applying a digital leading edge discriminator. Results: All 144 crystals were well resolved in the crystal flood map. The average full width half maximum (FWHM) energy resolution of the detector was 12.8% ± 1.5% with a FWHM CRT of 1.14 ± 0.02 ns. The average FWHM DoI resolution over 12 crystals was 2.90

  16. Impact of high (131)I-activities on quantitative (124)I-PET

    DEFF Research Database (Denmark)

    Braad, P E N; Hansen, Søren B.; Høilund-Carlsen, P F

    2015-01-01

    relevant [Formula: see text]I/[Formula: see text]I-activities were performed on a clinical PET/CT-system. Noise equivalent count rate (NECR) curves and quantitation accuracy were determined from repeated scans performed over several weeks on a decaying NEMA NU-2 1994 cylinder phantom initially filled...... [Formula: see text]I-activities was good and image quantification unaffected except at very high count rates. Quantitation accuracy and contrast recovery were uninfluenced at [Formula: see text]I-activities below 1000 MBq, whereas image noise was slightly increased. The NECR peaked at 550 MBq of [Formula......: see text]I, where it was 2.8 times lower than without [Formula: see text]I in the phantom. Quantitative peri-therapeutic [Formula: see text]I-PET is feasible....

  17. High-resolution PET (positron emission tomography) for medical science studies

    Energy Technology Data Exchange (ETDEWEB)

    Budinger, T.F.; Derenzo, S.E.; Huesman, R.H.; Jagust, W.J.; Valk, P.E. (Lawrence Berkeley Lab., CA (USA))

    1989-09-01

    One of the unexpected fruits of basic physics research and the computer revolution is the noninvasive imaging power available to today's physician. Technologies that were strictly the province of research scientists only a decade or two ago now serve as the foundations for such standard diagnostic tools as x-ray computer tomography (CT), magnetic resonance imaging (MRI), magnetic resonance spectroscopy (MRS), ultrasound, single photon emission computed tomography (SPECT), and positron emission tomography (PET). Furthermore, prompted by the needs of both the practicing physician and the clinical researcher, efforts to improve these technologies continue. This booklet endeavors to describe the advantages of achieving high resolution in PET imaging. 6 refs., 21 figs.

  18. PetIGA-MF: a multi-field high-performance toolbox for structure-preserving B-splines spaces

    KAUST Repository

    Sarmiento, Adel

    2016-10-01

    We describe a high-performance solution framework for isogeometric discrete differential forms based on B-splines: PetIGA-MF. Built on top of PetIGA, an open-source library we have built and developed over the last decade, PetIGA-MF is a general multi-field discretization tool. To test the capabilities of our implementation, we solve different viscous flow problems such as Darcy, Stokes, Brinkman, and Navier-Stokes equations. Several convergence benchmarks based on manufactured solutions are presented assuring optimal convergence rates of the approximations, showing the accuracy and robustness of our solver.

  19. Does the reuse of PET bottles during solar water disinfection pose a health risk due to the migration of plasticisers and other chemicals into the water?

    Science.gov (United States)

    Schmid, Peter; Kohler, Martin; Meierhofer, Regula; Luzi, Samuel; Wegelin, Martin

    2008-12-01

    Solar water disinfection (SODIS) is a simple, effective and inexpensive water treatment procedure suitable for application in developing countries. Microbially contaminated water is filled into transparent polyethylene terephthalate (PET) plastic bottles and exposed to full sunlight for at least 6h. Solar radiation and elevated temperature destroy pathogenic germs efficiently. Recently, concerns have been raised insinuating a health risk by chemicals released from the bottle material polyethylene terephthalate (PET). Whereas the safety of PET for food packaging has been assessed in detail, similar investigations for PET bottles used under conditions of the SODIS treatment were lacking until now. In the present study, the transfer of organic substances from PET to water was investigated under SODIS conditions using used colourless transparent beverage bottles of different origin. The bottles were exposed to sunlight for 17h at a geographical latitude of 47 degrees N. In a general screening of SODIS treated water, only food flavour constituents of previous bottle contents could be identified above a detection limit of 1 microg/L. Quantitative determination of plasticisers di(2-ethylhexyl)adipate (DEHA) and di(2-ethylhexyl)phthalate (DEHP) revealed maximum concentrations of 0.046 and 0.71 microg/L, respectively, being in the same range as levels of these plasticisers reported in studies on commercial bottled water. Generally, only minor differences in plasticiser concentrations could be observed in different experimental setups. The most decisive factor was the country of origin of bottles, while the impact of storage conditions (sunlight exposure and temperature) was less distinct. Toxicological risk assessment of maximum concentrations revealed a minimum safety factor of 8.5 and a negligible carcinogenic risk of 2.8 x 10(-7) for the more critical DEHP. This data demonstrate that the SODIS procedure is safe with respect to human exposure to DEHA and DEHP.

  20. {sup 18}F-FDG PET/contrast enhanced CT in the standard surveillance of high risk colorectal cancer patients

    Energy Technology Data Exchange (ETDEWEB)

    Jiménez Londoño, Germán Andrés, E-mail: gjimenez91@yahoo.com [Department of Nuclear Medicine, Hospital General Universitario de Ciudad Real, Ciudad Real (Spain); García Vicente, Ana María [Department of Nuclear Medicine, Hospital General Universitario de Ciudad Real, Ciudad Real (Spain); Sánchez Pérez, Victoria [Department of Oncology, Hospital General Universitario de Ciudad Real, Ciudad Real (Spain); Jiménez Aragón, Fátima [Department of Radiology, Hospital General Universitario de Ciudad Real, Ciudad Real (Spain); León Martin, Alberto [Investigation Unit, Hospital General Universitario de Ciudad Real, Ciudad Real (Spain); Cano Cano, Juana María [Department of Oncology, Hospital General Universitario de Ciudad Real, Ciudad Real (Spain); Domínguez Ferreras, Esther [Department of Radiology, Hospital General Universitario de Ciudad Real, Ciudad Real (Spain); Gómez López, Ober Van [Department of Nuclear Medicine, Hospital General Universitario de Ciudad Real, Ciudad Real (Spain); Espinosa Arranz, Javier [Department of Oncology, Hospital General Universitario de Ciudad Real, Ciudad Real (Spain); Soriano Castrejón, Ángel María [Department of Nuclear Medicine, Hospital General Universitario de Ciudad Real, Ciudad Real (Spain)

    2014-12-15

    Highlights: • We assessed the accuracy of FDG-PET/contrast enhanced CT (FDG-PET/ceCT) in the detection of unsuspected recurrence of colorectal cancer. In regard to our knowledge, no previous experience has been reported about the combined acquisition and interpretation of a FDG-PET/ceCT in the surveillance of colorectal cancer. • We designed a prospective study and performed an individual and combined assessment of both techniques (PET and ceCT), in a patient-based analysis and a lesion-based analysis. • The value of PET and ceCT was found to be similar in the detection of unsuspected recurrence of CRC in a patient-based analysis. The most interesting of our result, is that the combined assessment of PET/ceCT improves the accuracy in the lesion-based analysis. - Abstract: Objective: To assess the accuracy of FDG-PET/contrast enhanced CT (FDG-PET/ceCT) in the detection of unsuspected recurrence of colorectal cancer (CRC) in patients with high risk of relapse. Methods: Thirty-three patients (14 females and 19 males, mean age: 62, range: 41–78), with CRC in complete remission, were prospectively included. All patients underwent FDG-PET/ceCT (58 studies). FDG-PET/ceCT was requested in the surveillance setting, and performed following a standardized protocol. A portal venous phase CT scan was performed after the injection of iodinated contrast agent. An individual and combined assessment of both techniques (PET and ceCT) was performed. Concordant and discordant findings of PET, ceCT and FDG-PET/ceCT were compared in a patient-based and a lesion-based analysis. The final diagnosis, recurrence or disease free status (DFS), were established by histopathology or clinical/radiological follow-up of at least 6 months. Results: Seven out of 33 patients had a confirmed recurrence and the rest of patients had a DFS. In a patient-based analysis the sensitivity and specificity of PET, ceCT and PET/ceCT was of 86% and 88%, 86% and 92%, 86% and 85%, respectively. Attending to

  1. Performance of a PET Insert for High Resolution Small Animal PET/MR Imaging at 7T.

    Science.gov (United States)

    Stortz, Greg; Thiessen, Jonathan D; Bishop, Daryl; Khan, Muhammad S; Kozlowski, Piotr; Retière, Fabrice; Schellenberg, Graham; Shams, Ehsan; Zhang, Xuezhu; Thompson, Christopher J; Goertzen, Andrew; Sossi, Vesna

    2017-09-14

    We present the characterization of a compact magnetic resonance (MR) compatible positron emission tomography (PET) insert for simultaneous pre-clinical PET/MR imaging. While specifically designed with the strict size constraint to fit inside the 114 mm inner diameter of the BGA-12S gradient coil used in the Bruker 70/20 and 94/20 series of small animal MR imaging (MRI) systems, the insert can be easily installed in any appropriate MRI scanner or used as a stand-alone PET system. Methods: The insert is made from a ring of 16 detector-blocks each made from depth-of-interaction capable dual-layer-offset arrays of cerium-doped lutetium-yttrium oxyorthosilicate crystals read out by silicon photomultiplier (SiPM) arrays. Scintillator crystal arrays are made from 22×10 / 21×9 crystals in the bottom/top layers with 6/4 mm layer thicknesses, arranged with a 1.27 mm pitch, resulting in a useable field of view (FOV) 28 mm long and ~55 mm wide. Results: Spatial resolution ranges from 1.17 to 1.86 mm full-width-at-half-maximum (FWHM) in the radial direction from a radial offset of 0 to 15 mm. With a 300-800 keV energy window, peak sensitivity is 2.2% and noise-equivalent count rate (NECR) from a mouse-sized phantom at 3.7 MBq is 11.1 kcps and peaks at 20.8 kcps at 14.5 MBq. Phantom imaging shows that feature sizes as low as 0.7 mm can be resolved. 18F-fluorodeoxyglucose (18F-FDG) PET/MR images of mouse and rat brains show no signs of inter-modality interference, and can excellently resolve substructures within the brains. Conclusion: Due to excellent spatial resolvability and lack of intermodality interference, this PET insert will serve as a useful tool for pre-clinical PET/MR. Copyright © 2017 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

  2. Study of CT-based positron range correction in high resolution 3D PET imaging

    Energy Technology Data Exchange (ETDEWEB)

    Cal-Gonzalez, J., E-mail: jacobo@nuclear.fis.ucm.es [Grupo de Fisica Nuclear, Dpto. Fisica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid (Spain); Herraiz, J.L. [Grupo de Fisica Nuclear, Dpto. Fisica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid (Spain); Espana, S. [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States); Vicente, E. [Grupo de Fisica Nuclear, Dpto. Fisica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid (Spain); Instituto de Estructura de la Materia, Consejo Superior de Investigaciones Cientificas (CSIC), Madrid (Spain); Herranz, E. [Grupo de Fisica Nuclear, Dpto. Fisica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid (Spain); Desco, M. [Unidad de Medicina y Cirugia Experimental, Hospital General Universitario Gregorio Maranon, Madrid (Spain); Vaquero, J.J. [Dpto. de Bioingenieria e Ingenieria Espacial, Universidad Carlos III, Madrid (Spain); Udias, J.M. [Grupo de Fisica Nuclear, Dpto. Fisica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid (Spain)

    2011-08-21

    Positron range limits the spatial resolution of PET images and has a different effect for different isotopes and positron propagation materials. Therefore it is important to consider it during image reconstruction, in order to obtain optimal image quality. Positron range distributions for most common isotopes used in PET in different materials were computed using the Monte Carlo simulations with PeneloPET. The range profiles were introduced into the 3D OSEM image reconstruction software FIRST and employed to blur the image either in the forward projection or in the forward and backward projection. The blurring introduced takes into account the different materials in which the positron propagates. Information on these materials may be obtained, for instance, from a segmentation of a CT image. The results of introducing positron blurring in both forward and backward projection operations was compared to using it only during forward projection. Further, the effect of different shapes of positron range profile in the quality of the reconstructed images with positron range correction was studied. For high positron energy isotopes, the reconstructed images show significant improvement in spatial resolution when positron range is taken into account during reconstruction, compared to reconstructions without positron range modeling.

  3. Use of FDG PET/CT for investigation of febrile neutropenia: evaluation in high-risk cancer patients.

    Science.gov (United States)

    Guy, Stephen D; Tramontana, Adrian R; Worth, Leon J; Lau, Eddie; Hicks, Rodney J; Seymour, John F; Thursky, Karin A; Slavin, Monica A

    2012-08-01

    Febrile neutropenia (FNP) is a frequent complication of cancer care and evaluation often fails to identify a cause. [(18) F]FDG PET/CT has the potential to identify inflammatory and infectious foci, but its potential role as an investigation for persistent FNP has not previously been explored. The aim of this study was to prospectively evaluate the clinical utility of FDG PET/CT in patients with cancer and severe neutropenia and five or more days of persistent fever despite antibiotic therapy. Adult patients with a diagnosis of an underlying malignancy and persistent FNP (temperature ≥38°C and neutrophil count FNP who fulfilled the eligibility criteria and underwent FDG PET/CT in addition to conventional evaluation. The median neutrophil count on the day of the FDG PET/CT scan was 30 cells/μl (range 0-730 cells/μl). Conventional evaluation identified 14 distinct sites of infection, 13 (93 %) of which were also identified by FDG PET/CT, including all deep tissue infections. FDG PET/CT identified 9 additional likely infection sites, 8 of which were subsequently confirmed as "true positives" by further investigations. FDG PET/CT was deemed to be of 'high' clinical impact in 15 of the 20 patients (75 %). This study supports the utility of FDG PET/CT scanning in severely neutropenic patients with five or more days of fever. Further evaluation of the contribution of FDG PET/CT in the management of FNP across a range of underlying malignancies is required.

  4. Fat-constrained 18F-FDG PET reconstruction in hybrid PET/MR imaging.

    Science.gov (United States)

    Prevrhal, Sven; Heinzer, Susanne; Wülker, Christian; Renisch, Steffen; Ratib, Osman; Börnert, Peter

    2014-10-01

    Fusion of information from PET and MR imaging can increase the diagnostic value of both modalities. This work sought to improve (18)F FDG PET image quality by using MR Dixon fat-constrained images to constrain PET image reconstruction to low-fat regions, with the working hypothesis that fatty tissue metabolism is low in glucose consumption. A novel constrained PET reconstruction algorithm was implemented via a modification of the system matrix in list-mode time-of-flight ordered-subsets expectation maximization reconstruction, similar to the way time-of-flight weighting is incorporated. To demonstrate its use in PET/MR imaging, we modeled a constraint based on fat/water-separating Dixon MR images that shift activity away from regions of fat tissue during PET image reconstruction. PET and MR imaging scans of a modified National Electrical Manufacturers Association/International Electrotechnical Commission body phantom simulating body fat/water composition and in vivo experiments on 2 oncology patients were performed on a commercial time-of-flight PET/MR imaging system. Fat-constrained PET reconstruction visibly and quantitatively increased resolution and contrast between high-uptake and fatty-tissue regions without significantly affecting the images in nonfat regions. The incorporation of MR tissue information, such as fat, in image reconstruction can improve the quality of PET images. The combination of a variety of potential other MR tissue characteristics with PET represents a further justification for merging MR data with PET data in hybrid systems. © 2014 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

  5. Facile method to prepare a transparent superhydrophobic PET film

    Science.gov (United States)

    Wang, Jian; Chen, Hong; Wang, Xian; Yuan, Zhiqing

    2016-11-01

    A simple method to fabricate a transparent superhydrophobic coating was developed by spraying PDMS/SiO2 nanoparticles suspension on a hydrophilic PET film. This PDMS/SiO2 nanoparticles suspension was prepared by fully diluting and properly stirring. When this suspension was sprayed on the surface of PET film at a distance of about 30 cm for 2 s, a porous micro-nano-binary structure was formed, which endowed the hydrophilic PET film superhydrophobicity, while the PET film maintained transparent after spraying with a SiO2 nanoparticle layer. The as-prepared superhydrophobic PET film exhibited a high water contact angle of about 155° ± 1.9° and a low water sliding angle of about 7°. The formation mechanism of this transparent superhydrophobic coating on PET film was also discussed in detail in this paper.

  6. Concurrent low brain and high liver uptake on FDG PET are associated with cardiovascular risk factors

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Hyun Yeol [Dept. of Nuclear Medicine, Samsung Changwon Hospital, Sungkyunkwan University School of Medicine, Changwon (Korea, Republic of); Jun, Sung Min [Dept. of Nuclear Medicine, Kosin University Gospel Hospital, Kosin University College of Medicine, Busan (Korea, Republic of); Pak, Kyoung June; Kim, In Joo [Dept. of Nuclear Medicine and Biomedical Research Institute, Pusan National University Hospital, Busan (Korea, Republic of)

    2017-04-15

    Concurrent low brain and high liver uptake are sometimes observed on fluorine-18-labeled fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET). We investigated the potential clinical significance of this uptake pattern related to metabolic syndrome (MS). We retrospectively reviewed data from 264 consecutive males who had undergone general health check-ups, including FDG PET/CT scans. After an overnight fast, the men had their peripheral blood drawn and the levels of various laboratory parameters measured; an FDG PET/CT scan was performed on the same day. We measured the maximum standardized uptake values of the brain and liver from regions of interest manually placed over the frontal cortex at the level of the centrum semiovale and the right lobe of the liver parenchyma, respectively. Fasting blood glucose (FBG; odds ratio [OR] = 1.063, p < 0.001) and glycated hemoglobin (HbA1c; OR = 3.634, p = 0.010) were the strongest predictive factors for low brain FDG uptake, whereas waist circumference (OR = 1.200, p < 0.001) and γ-glutamyl transpeptidase (OR = 1.012, p = 0.001) were the strongest predictive factors for high liver uptake. Eleven subjects (4.2%) showed concurrent low brain and high liver FDG uptake, and all but one of these subjects (90.9%) had MS. Systolic blood pressure, waist circumference, FBG, triglyceride, alanine aminotransferase, insulin resistance (measured by homeostasis model assessment), insulin, HbA1c, and body mass index were higher in subjects with this FDG uptake pattern than in those without (all, p < 0.001). Concurrent low brain and high liver FDG uptake were closely associated with MS. Moreover, subjects with this pattern had higher values for various cardiovascular risk factors than did those without.

  7. Continuous MR bone density measurement using water- and fat-suppressed projection imaging (WASPI) for PET attenuation correction in PET-MR

    Science.gov (United States)

    Huang, C.; Ouyang, J.; Reese, T. G.; Wu, Y.; El Fakhri, G.; Ackerman, J. L.

    2015-10-01

    Due to the lack of signal from solid bone in normal MR sequences for the purpose of MR-based attenuation correction, investigators have proposed using the ultrashort echo time (UTE) pulse sequence, which yields signal from bone. However, the UTE-based segmentation approach might not fully capture the intra- and inter-subject bone density variation, which will inevitably lead to bias in reconstructed PET images. In this work, we investigated using the water- and fat-suppressed proton projection imaging (WASPI) sequence to obtain accurate and continuous attenuation for bones. This approach is capable of accounting for intra- and inter-subject bone attenuation variations. Using data acquired from a phantom, we have found that that attenuation correction based on the WASPI sequence is more accurate and precise when compared to either conventional MR attenuation correction or UTE-based segmentation approaches.

  8. Performance of a high-resolution depth encoding PET detector using barium sulfate reflector

    Science.gov (United States)

    Kuang, Zhonghua; Wang, Xiaohui; Li, Cheng; Deng, Xinhan; Feng, Kai; Hu, Zhanli; Fu, Xin; Ren, Ning; Zhang, Xianming; Zheng, Yunfei; Liang, Dong; Liu, Xin; Zheng, Hairong; Yang, Yongfeng

    2017-08-01

    Small animal positron emission tomography (PET) is a well-established imaging modality in preclinical biomedical research. The performance of current small animal PET scanners is mainly limited by the detector performance and depth-encoding detectors are required to simultaneously achieve high spatial resolution and high sensitivity. In this work, the performance of a high-resolution dual-ended readout lutetium-yttrium oxyorthosilicate (LYSO) array using barium sulfate powder (BaSO4) as the inter-crystal reflector was measured for the first time and compared to that of a LYSO array using the most commonly used enhanced specular reflector (ESR). Both LYSO arrays have 18  ×  18 crystals and the crystal size is about 0.62  ×  0.62  ×  20 mm3. The LYSO arrays are readout by two position-sensitive photomultiplier tubes (PSPMTs) from both ends. The flood histograms, energy resolution, depth of interaction (DOI) resolution and timing resolution were measured. The flood histograms of the LYSO array with BaSO4 reflector is much better than that of the LYSO array with ESR reflector. For the BaSO4 array, all crystals can be clearly resolved. For the ESR array, all crystals in one direction can be clearly resolved, but the edge 2-3 columns of the crystals in the other direction cannot be resolved. The average energy resolution of the BaSO4 and ESR arrays are 15.2% and 15.3%, respectively. The average DOI resolution of the BaSO4 array is 2.19 mm, which is 24% worse than the 1.76 mm DOI resolution of the ESR array. The timing resolution of both arrays is ~1.6 ns. The LYSO array with the new BaSO4 reflector provided an much better flood histogram in a high resolution dual-ended readout PET detectors as compared to the ESR array, and will be used to develop a small animal PET scanner that can simultaneously achieve uniform high spatial resolution, high sensitivity and low cost.

  9. Performance of a high-resolution depth encoding PET detector using barium sulfate reflector.

    Science.gov (United States)

    Kuang, Zhonghua; Wang, Xiaohui; Li, Cheng; Deng, Xinhan; Feng, Kai; Hu, Zhanli; Fu, Xin; Ren, Ning; Zhang, Xianming; Zheng, Yunfei; Liang, Dong; Liu, Xin; Zheng, Hairong; Yang, Yongfeng

    2017-07-06

    Small animal positron emission tomography (PET) is a well-established imaging modality in preclinical biomedical research. The performance of current small animal PET scanners is mainly limited by the detector performance and depth-encoding detectors are required to simultaneously achieve high spatial resolution and high sensitivity. In this work, the performance of a high-resolution dual-ended readout lutetium-yttrium oxyorthosilicate (LYSO) array using barium sulfate powder (BaSO4) as the inter-crystal reflector was measured for the first time and compared to that of a LYSO array using the most commonly used enhanced specular reflector (ESR). Both LYSO arrays have 18  ×  18 crystals and the crystal size is about 0.62  ×  0.62  ×  20 mm3. The LYSO arrays are readout by two position-sensitive photomultiplier tubes (PSPMTs) from both ends. The flood histograms, energy resolution, depth of interaction (DOI) resolution and timing resolution were measured. The flood histograms of the LYSO array with BaSO4 reflector is much better than that of the LYSO array with ESR reflector. For the BaSO4 array, all crystals can be clearly resolved. For the ESR array, all crystals in one direction can be clearly resolved, but the edge 2-3 columns of the crystals in the other direction cannot be resolved. The average energy resolution of the BaSO4 and ESR arrays are 15.2% and 15.3%, respectively. The average DOI resolution of the BaSO4 array is 2.19 mm, which is 24% worse than the 1.76 mm DOI resolution of the ESR array. The timing resolution of both arrays is ~1.6 ns. The LYSO array with the new BaSO4 reflector provided an much better flood histogram in a high resolution dual-ended readout PET detectors as compared to the ESR array, and will be used to develop a small animal PET scanner that can simultaneously achieve uniform high spatial resolution, high sensitivity and low cost.

  10. Treatment response evaluation with 18F-FDG PET/CT and 18F-NaF PET/CT in multiple myeloma patients undergoing high-dose chemotherapy and autologous stem cell transplantation.

    Science.gov (United States)

    Sachpekidis, Christos; Hillengass, J; Goldschmidt, H; Wagner, B; Haberkorn, U; Kopka, K; Dimitrakopoulou-Strauss, A

    2017-01-01

    The aim of this study was to assess the combined use of the radiotracers 18F-FDG and 18F-NaF in treatment response evaluation of a group of multiple myeloma (MM) patients undergoing high-dose chemotherapy (HDT) followed by autologous stem cell transplantation (ASCT) by means of static (whole-body) and dynamic PET/CT (dPET/CT). Thirty-four patients with primary, previously untreated MM scheduled for treatment with HDT followed by ASCT were enrolled in the study. All patients underwent PET/CT scanning with 18F-FDG and 18F-NaF before and after therapy. Treatment response by means of PET/CT was assessed according to the European Organization for Research and Treatment of Cancer (EORTC) 1999 criteria. The evaluation of dPET/CT studies was based on qualitative evaluation, semi-quantitative (SUV) calculation, and quantitative analysis based on two-tissue compartment modelling and a non-compartmental approach leading to the extraction of fractal dimension (FD). An analysis was possible in 29 patients: three with clinical complete response (CR) and 26 with non-CR (13 patients near complete response-nCR, four patients very good partial response-VGPR, nine patients partial response-PR). After treatment, 18F-FDG PET/CT was negative in 14/29 patients and positive in 15/29 patients, showing a sensitivity of 57.5 % and a specificity of 100 %. According to the EORTC 1999 criteria, 18F-FDG PET/CT-based treatment response revealed CR in 14 patients (18F-FDG PET/CT CR), PR in 11 patients (18F-FDG PET/CT PR) and progressive disease in four patients (18F-FDG PET/CT PD). In terms of 18F-NaF PET/CT, 4/29 patients (13.8 %) had a negative baseline scan, thus failed to depict MM. Regarding the patients for which a direct lesion-to-lesion comparison was feasible, 18F-NaF PET/CT depicted 56 of the 129 18F-FDG positive lesions (43 %). Follow-up 18F-NaF PET/CT showed persistence of 81.5 % of the baseline 18F-NaF positive MM lesions after treatment, despite the fact that 64.7 % of them had

  11. PET-Probe: Evaluation of Technical Performance and Clinical Utility of a Handheld High-Energy Gamma Probe in Oncologic Surgery.

    Science.gov (United States)

    Gulec, Seza A; Daghighian, Farhad; Essner, Richard

    2016-12-01

    Positron emission tomography (PET) has become an invaluable part of patient evaluation in surgical oncology. PET is less than optimal for detecting lesions PET-positive lesions can be challenging as a result of difficulties in surgical exposure. We undertook this investigation to assess the utility of a handheld high-energy gamma probe (PET-Probe) for intraoperative identification of 18F-deoxyglucose (FDG)-avid tumors. Forty patients underwent a diagnostic whole-body FDG-PET scan for consideration for surgical exploration and resection. Before surgery, all patients received an intravenous injection of 7 to 10 mCi of FDG. At surgery, the PET-Probe was used to determine absolute counts per second at the known tumor site(s) demonstrated by whole-body PET and at adjacent normal tissue (at least 4 cm away from tumor-bearing sites). Tumor-to-background ratios were calculated. Thirty-two patients (80%) underwent PET-Probe-guided surgery with therapeutic intent in a recurrent or metastatic disease setting. Eight patients underwent surgery for diagnostic exploration. Anatomical locations of the PET-identified lesions were neck and supraclavicular (n = 8), axilla (n = 5), groin and deep iliac (n = 4), trunk and extremity soft tissue (n = 3), abdominal and retroperitoneal (n = 19), and lung (n = 2). PET-Probe detected all PET-positive lesions. The PET-Probe was instrumental in localization of lesions in 15 patients that were not immediately apparent by surgical exploration. The PET-Probe identified all lesions demonstrated by PET scanning and, in selected cases, was useful in localizing FDG-avid disease not seen with conventional PET scanning.

  12. High Throughput Plasma Water Treatment

    Science.gov (United States)

    Mujovic, Selman; Foster, John

    2016-10-01

    The troublesome emergence of new classes of micro-pollutants, such as pharmaceuticals and endocrine disruptors, poses challenges for conventional water treatment systems. In an effort to address these contaminants and to support water reuse in drought stricken regions, new technologies must be introduced. The interaction of water with plasma rapidly mineralizes organics by inducing advanced oxidation in addition to other chemical, physical and radiative processes. The primary barrier to the implementation of plasma-based water treatment is process volume scale up. In this work, we investigate a potentially scalable, high throughput plasma water reactor that utilizes a packed bed dielectric barrier-like geometry to maximize the plasma-water interface. Here, the water serves as the dielectric medium. High-speed imaging and emission spectroscopy are used to characterize the reactor discharges. Changes in methylene blue concentration and basic water parameters are mapped as a function of plasma treatment time. Experimental results are compared to electrostatic and plasma chemistry computations, which will provide insight into the reactor's operation so that efficiency can be assessed. Supported by NSF (CBET 1336375).

  13. Evaluation of compressive strength and water absorption of soil-cement bricks manufactured with addition of pet (polyethylene terephthalate wastes

    Directory of Open Access Journals (Sweden)

    João Alexandre Paschoalin Filho

    2016-04-01

    Full Text Available This paper presents the evaluation of compressive strength of soil-cement bricks obtained by the inclusion in their mixture of PET flakes through mineral water bottles grinding. The Polyethylene Terephthalate (PET has been characterized by its difficulty of disaggregation in nature, requiring a long period for this. On the other hand, with the increase in civil construction activities the demand for raw material also increases, causing considerable environmental impacts. In this context, the objective of this research is to propose a simple methodology, preventing its dumping and accumulation in irregular areas, and reducing the demand of raw materials by the civil construction industry. The results showed that compressive strengths obtained were lower than recommended by NBR 8491 (Associação Brasileira de Normas Técnicas [ABNT], 2012b at seven days of curing time. However, they may be used as an alternative solution in masonry works in order to not submit themselves to great loads or structural functions. The studied bricks also presented water absorption near to recommended values by NBR 8491 (ABNT, 2012b. Manufacturing costs were also determined for this brick, comparing it with the costs of other brick types. Each brick withdrew from circulation approximately 300 g of PET waste. Thus, for an area of 1 m2 the studied bricks can promote the withdrawal of approximately 180 beverage bottles of 2 L capacity.

  14. High uptake of (68)Ga-DOTATOC in spleen as compared to splenosis: measurement by PET/CT.

    Science.gov (United States)

    Kulkarni, Harshad R; Prasad, Vikas; Kaemmerer, Daniel; Hommann, Merten; Baum, Richard P

    2013-01-01

    The aim of this study is to ascertain the high somatostatin receptor (SSTR) uptake in spleen and to compare the uptake in spleen and splenosis using SSTR PET/CT using( 68)Ga-DOTATOC. SUV(max) of spleen on (68)Ga-DOTATOC SSTR PET/CT (acquired for initial staging) in 10 patients with known neuroendocrine neoplasm of pancreatic tail was analyzed. All patients underwent left pancreatectomy and splenectomy. Diagnosis of splenosis was confirmed on CT, and SUV(max) was noted on follow-up SSTR PET/CT. SUV(max)was 28.8 ± 12.5 in normal spleen and 10.5 ± 4.3 in splenosis. The high uptake of( 68)Ga-DOTATOC (which has a high affinity to SSTR 2) in the spleen as compared to splenosis, which has a different histology, suggests white pulp as the probable site of high SSTR 2 expression.

  15. Enhancing the Multivariate Signal of 15O water PET Studies With a New Non-Linear Neuroanatomical Registration Algorithm

    DEFF Research Database (Denmark)

    Kjems, Ulrik; Storther, Stephen C.; Anderson, Jon

    1999-01-01

    that improved structural registration may result in an improved multivariate functional signal-tonoise ratio. Furthermore registration of PET scans using the 12-parameter affine transformations that align the co-registered MR images does not improve registration compared to 12-parameter affine alignment......This paper addresses the problem of neuro-anatomical registration across individuals for functional [15O]water PET activation studies. A new algorithm for 3D non-linear structural registration (warping) of MR scans is presented. The method performs a hierarchically scaled search for a displacement...... field maximizing one of several voxel similarity measures derived from the two dimensional histogram of matched image intensities, subject to a regularizer that ensures smoothness of the displacement field. The effect of the non-line ar structural registration is studied when it is computed...

  16. Observing the high resolution capabilities of a silicon PET insert probe

    Science.gov (United States)

    Brzezinski, K.; Oliver, J. F.; Gillam, J.; Lacasta, C.; Rafecas, M.

    2011-03-01

    A high resolution silicon detector probe in coincidence with a conventional PET scanner should be able to increase the scanner's spatial resolution. The MADEIRA PET probe is such a device and was simulated in coincidence with a clinical scanner was simulated using the Monte Carlo package GATE. The device consists of ten layers of silicon of 1x1x1 mm3 pixels in a 80x52 array. Simulations were run with various activity distributions. No attenuation was included to reduce the amount of scatter in the simulated data. The simulations were conducted in air. Coincidence sorting was performed on the singles list mode data. Random coincidences were rejected and no time or energy blurring was used in order to isolate the events which determine the highest achievable spatial resolution. Sinograms where calculated from the sorted data with one sinogram containing events where both annihilation photons were detected in the PET ring and another for probe-ring events. The probe-ring sinograms identified the limited FOV of the probe. The point-spread function was calculated from the sinograms. The full-width half-maximum decreased from 5.5 mm in the ring-ring sinogram to 2.7 mm in the ring-probe sinogram. The full-width third-maximum decreased from 7 mm to 3 mm. Images were reconstructed using the Maximum Likelihood-Expectation Maximization (ML-EM) algorithm using the list-mode coincidence data. The improvement in spatial resolution seen in the sinograms is reflected in the images.

  17. Design and performance evaluation of a high resolution IRI-microPET preclinical scanner

    Energy Technology Data Exchange (ETDEWEB)

    Islami rad, S.Z., E-mail: szislami@yahoo.com [Department of Physic, Faculty of Science, University of Qom, Qom (Iran, Islamic Republic of); Peyvandi, R. Gholipour; Lehdarboni, M. Askari; Ghafari, A.A. [Instrumentation Research Group, Nuclear Science and Technology Research Institute, Tehran (Iran, Islamic Republic of)

    2015-05-01

    PET for small animal, IRI-microPET, was designed and built at the NSTRI. The scanner is made of four detectors positioned on a rotating gantry at a distance 50 mm from the center. Each detector consists of a 10×10 crystal matrix of 2×2×10 mm{sup 3} directly coupled to a PS-PMT. A position encoding circuit for specific PS-PMT has been designed, built and tested with a PD-MFS-2MS/s-8/14 data acquisition board. After implementing reconstruction algorithms (FBP, MLEM and SART) on sinograms, images quality and system performance were evaluated by energy resolution, timing resolution, spatial resolution, scatter fraction, sensitivity, RMS contrast and SNR parameters. The energy spectra were obtained for the crystals with an energy window of 300–700 keV. The energy resolution in 511 keV averaged over all modules, detectors, and crystals, was 23.5%. A timing resolution of 2.4 ns FWHM obtained by coincidence timing spectrum was measured with crystal LYSO. The radial and tangential resolutions for {sup 18}F (1.15-mm inner diameter) at the center of the field of view were 1.81 mm and 1.90 mm, respectively. At a radial offset of 5 mm, the FWHM values were 1.96 and 2.06 mm. The system scatter fraction was 7.1% for the mouse phantom. The sensitivity was measured for different energy windows, leading to a sensitivity of 1.74% at the center of FOV. Also, images quality was evaluated by RMS contrast and SNR factors, and the results show that the reconstructed images by MLEM algorithm have the best RMS contrast, and SNR. The IRI-microPET presents high image resolution, low scatter fraction values and improved SNR for animal studies.

  18. Improved clinical workflow for simultaneous whole-body PET/MRI using high-resolution CAIPIRINHA-accelerated MR-based attenuation correction.

    Science.gov (United States)

    Freitag, Martin T; Fenchel, Matthias; Bäumer, Philipp; Heußer, Thorsten; Rank, Christopher M; Kachelrieß, Marc; Paech, Daniel; Kopka, Klaus; Bickelhaupt, Sebastian; Dimitrakopoulou-Strauss, Antonia; Maier-Hein, Klaus; Floca, Ralf; Ladd, Mark E; Schlemmer, Heinz-Peter; Maier, Florian

    2017-11-01

    To explore the value and reproducibility of a novel magnetic resonance based attenuation correction (MRAC) using a CAIPIRINHA-accelerated T1-weighted Dixon 3D-VIBE sequence for whole-body PET/MRI compared to the clinical standard. The PET raw data of 19 patients from clinical routine were reconstructed with standard MRAC (MRACstd) and the novel MRAC (MRACcaipi), a prototype CAIPIRINHA accelerated Dixon 3D-VIBE sequence, both acquired in 19 s/bed position. Volume of interests (VOIs) for liver, lung and all voxels of the total image stack were created to calculate standardized uptake values (SUVmean) followed by inter-method agreement (Passing-Bablok regression, Bland-Altman analysis). A voxel-wise SUV comparison per patient was performed for intra-individual correlation between MRACstd and MRACcaipi. Difference images (MRACstd-MRACcaipi) of attenuation maps and SUV images were calculated. The image quality of in/opposed-phase water and fat images obtained from MRACcaipi was assessed by two readers on a 5-point Likert-scale including intra-class coefficients for inter-reader agreement. SUVmean correlations of VOIs demonstrated high linearity (0.95attenuation correction by providing a high spatial resolution DIXON-based dataset suited for diagnostic assessment towards time-efficient whole-body PET/MRI. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Investigation of a Dedicated, High Resolution PET/CT Scanner for Staging and Treatment Planning of Head and Neck Cancer

    Science.gov (United States)

    Raylman, Raymond R.; Stolin, Alexander V.; Sompalli, Prashanth; Randall, Nicole Bunda; Martone, Peter F.; Clinthorne, Neal H.

    2015-10-01

    Staging of head and neck cancer (HNC) is often hindered by the limited resolution of standard whole body PET scanners, which can make it challenging to detect small areas of metastatic disease in regional lymph nodes and accurately delineate tumor boundaries. In this investigation, the performance of a proposed high resolution PET/CT scanner designed specifically for imaging of the head and neck region was explored. The goal is to create a dedicated PET/CT system that will enhance the staging and treatment of HNCs. Its performance was assessed by simulating the scanning of a three-dimensional Rose-Burger contrast phantom. To extend the results from the simulation studies, an existing scanner with a similar geometry to the dedicated system and a whole body, clinical PET/CT scanner were used to image a Rose-Burger contrast phantom and a phantom simulating the neck of an HNC patient (out-of-field-of-view sources of activity were not included). Images of the contrast detail phantom acquired with Breast-PET/CT and simulated head and neck scanner both produced object contrasts larger than the images created by the clinical scanner. Images of a neck phantom acquired with the Breast-PET/CT scanner permitted the identification of all of the simulated metastases, while it was not possible to identify any of the simulated metastasis with the clinical scanner. The initial results from this study demonstrate the potential benefits of high-resolution PET systems for improving the diagnosis and treatment of HNC.

  20. A prototype of very high-resolution small animal PET scanner using silicon pad detectors

    CERN Document Server

    Park, S J; Huh, S; Kagan, H; Honscheid, K; Burdette, D; Chesi, Enrico Guido; Lacasta, C; Llosa, G; Mikuz, M; Studen, A; Weilhammer, P; Clinthorne, N H

    2007-01-01

    Abstract A very high-resolution small animal positron emission tomograph (PET), which can achieve sub-millimeter spatial resolution, is being developed using silicon pad detectors. The prototype PET for a single slice instrument consists of two 1 mm thick silicon pad detectors, each containing a 32×16 array of 1.4×1.4 mm pads readout with four VATAGP3 chips which have 128 channels low-noise self-triggering ASIC in each chip, coincidence units, a source turntable and tungsten slice collimator. The silicon detectors were located edgewise on opposite sides of a 4 cm field-of-view to maximize efficiency. Energy resolution is dominated by electronic noise, which is 0.98% (1.38 keV) FWHM at 140.5 keV. Coincidence timing resolution is 82.1 ns FWHM and coincidence efficiency was measured to be 1.04×10−3% from two silicon detectors with annihilation photons of 18F source. Image data were acquired and reconstructed using conventional 2-D filtered-back projection (FBP) and a maximum likelihood expectation maximizat...

  1. The use of 18F-FDG PET to differentiate progressive disease from treatment induced necrosis in high grade glioma

    NARCIS (Netherlands)

    Dankbaar, J. W.; Snijders, T. J.; Robe, P. A.; Seute, T.; Eppinga, W.; Hendrikse, J.; De Keizer, B.

    2015-01-01

    In the follow-up of patients treated for high grade glioma, differentiation between progressive disease (PD) and treatment-induced necrosis (TIN) is challenging. The purpose of this study is to evaluate the diagnostic accuracy of FDG PET for the differentiation between TIN and PD after high grade

  2. Field comparison of solar water disinfection (SODIS) efficacy between glass and polyethylene terephalate (PET) plastic bottles under sub-Saharan weather conditions.

    Science.gov (United States)

    Asiimwe, J K; Quilty, B; Muyanja, C K; McGuigan, K G

    2013-12-01

    Concerns about photodegradation products leaching from plastic bottle material into water during solar water disinfection (SODIS) are a major psychological barrier to increased uptake of SODIS. In this study, a comparison of SODIS efficacy using glass and plastic polyethylene terephalate (PET) bottles was carried out under strong real sunlight and overcast weather conditions at Makerere University in central Uganda. Both clear and turbid natural water samples from shallow wells and open dug wells, respectively, were used. Efficacy was determined from the inactivation of a wild strain of Escherichia coli in solar-exposed contaminated water in both glass and PET bottles. The studies reveal no significant difference in SODIS inactivation between glass and PET bottles (95% CI, p > 0.05), for all water samples under the different weather conditions except for clear water under overcast conditions where there was a small but significant difference (95% CI, p = 0.047) with less viable bacterial counts in PET bottles at two intermediate time points but not at the end of the exposure. The results demonstrate that SODIS efficacy in glass under tropical field conditions is comparable to PET plastic. SODIS users in these regions can choose either of reactors depending on availability and preference of the user.

  3. COMPET: High resolution high sensitivity MRI compatible pre-clinical PET scanner

    CERN Document Server

    Hines, Kim-Eigard; Skretting, Arne; Rohne, Ole; Bjaalie, Jan G; Volgyes, David; Rissi, Michael; Dorholt, Ole; Stapnes, Steinar

    2013-01-01

    COMPET is a pre-clinical MRI compatible PET scanner which decouples sensitivity and resolution by the use of a novel detector design. The detector has been built using 8 x 8 cm(2) square layers consisting of 30 LYSO crystals (2 x 3 x 80 mm(2)) interleaved with 24 Wavelength Shifting Fibers (WLS) (3 x 1 x 80 mm(3)). By stacking several layers into a module, the point-of-interaction (POI) can be measured in 3D. Four layers form a PET ring where the sensitivity can be increased by stacking several layers. The layers can be stacked so that no inter-crystal or inter-module gap is formed. COMPET has used four assembled layers for module and scanner characterization. The modules are connected to the COMPET data-acquisition chain and the reconstructed images are produced with the novel geometry-independent COMPET image reconstruction algorithm. Time and energy resolution have been resolved and found to be around 4 as and 14% respectively. Tests for MRI interference and count rate performance have been carried out The...

  4. Atomically Monodisperse Nickel Nanoclusters as Highly Active Electrocatalysts for Water Oxidation

    KAUST Repository

    Joya, Khurram

    2016-04-08

    Achieving water splitting at low overpotential with high oxygen evolution efficiency and stability is important for realizing solar to chemical energy conversion devices. Herein we report the synthesis, characterization and electrochemical evaluation of highly active nickel nanoclusters (Ni NCs) for water oxidation at low overpotential. These atomically precise and monodisperse Ni NCs are characterized by using UV-visible absorption spectroscopy, single crystal X-ray diffraction and mass spectrometry. The molecular formulae of these Ni NCs are found to be Ni4(PET)8 and Ni6(PET)12 and are highly active electrocatalysts for oxygen evolution without any pre-conditioning. Ni4(PET)8 are slightly better catalysts than Ni6(PET)12 and initiate the oxygen evolution at an amazingly low overpotential of ~1.51 V (vs RHE; η ≈ 280 mV). The peak oxygen evolution current density (J) of ~150 mA cm–2 at 2.0 V (vs. RHE) with a Tafel slope of 38 mV dec–1 is observed using Ni4(PET)8. These results are comparable to the state-of-the art RuO2 electrocatalyst, which is highly expensive and rare compared to Ni-based materials. Sustained oxygen generation for several hours with an applied current density of 20 mA cm–2 demonstrates the long-term stability and activity of these Ni NCs towards electrocatalytic water oxidation. This unique approach provides a facile method to prepare cost-effective, nanoscale and highly efficient electrocatalysts for water oxidation.

  5. High-resolution dynamic imaging and quantitative analysis of lung cancer xenografts in nude mice using clinical PET/CT

    Science.gov (United States)

    Wang, Ying Yi; Wang, Kai; Xu, Zuo Yu; Song, Yan; Wang, Chu Nan; Zhang, Chong Qing; Sun, Xi Lin; Shen, Bao Zhong

    2017-01-01

    Considering the general application of dedicated small-animal positron emission tomography/computed tomography is limited, an acceptable alternative in many situations might be clinical PET/CT. To estimate the feasibility of using clinical PET/CT with [F-18]-fluoro-2-deoxy-D-glucose for high-resolution dynamic imaging and quantitative analysis of cancer xenografts in nude mice. Dynamic clinical PET/CT scans were performed on xenografts for 60 min after injection with [F-18]-fluoro-2-deoxy-D-glucose. Scans were reconstructed with or without SharpIR method in two phases. And mice were sacrificed to extracting major organs and tumors, using ex vivo γ-counting as a reference. Strikingly, we observed that the image quality and the correlation between the all quantitive data from clinical PET/CT and the ex vivo counting was better with the SharpIR reconstructions than without. Our data demonstrate that clinical PET/CT scanner with SharpIR reconstruction is a valuable tool for imaging small animals in preclinical cancer research, offering dynamic imaging parameters, good image quality and accurate data quatification. PMID:28881772

  6. Denoising of high resolution small animal 3D PET data using the non-subsampled Haar wavelet transform

    Energy Technology Data Exchange (ETDEWEB)

    Ochoa Domínguez, Humberto de Jesús, E-mail: hochoa@uacj.mx [Departamento de Ingeniería Eléctrica y computación, Universidad Autónoma de Ciudad Juárez, Ciudad Juárez, Chih. (Mexico); Máynez, Leticia O. [Departamento de Ingeniería Eléctrica y computación, Universidad Autónoma de Ciudad Juárez, Ciudad Juárez, Chih. (Mexico); Vergara Villegas, Osslan O. [Departamento de Ingeniería Industrial, Universidad Autónoma de Ciudad Juárez, Ciudad Juárez, Chih. (Mexico); Mederos, Boris; Mejía, José M.; Cruz Sánchez, Vianey G. [Departamento de Ingeniería Eléctrica y computación, Universidad Autónoma de Ciudad Juárez, Ciudad Juárez, Chih. (Mexico)

    2015-06-01

    PET allows functional imaging of the living tissue. However, one of the most serious technical problems affecting the reconstructed data is the noise, particularly in images of small animals. In this paper, a method for high-resolution small animal 3D PET data is proposed with the aim to reduce the noise and preserve details. The method is based on the estimation of the non-subsampled Haar wavelet coefficients by using a linear estimator. The procedure is applied to the volumetric images, reconstructed without correction factors (plane reconstruction). Results show that the method preserves the structures and drastically reduces the noise that contaminates the image.

  7. High Resolution Image Reconstruction Method for a Double-plane PET System with Changeable Spacing

    CERN Document Server

    Gu, Xiao-Yue; Li, Lin; Yin, Peng-Fei; Shang, Lei-Min; Yun, Ming-Kai; Lu, Zhen-Rui; Huang, Xian-Chao; Wei, Long

    2015-01-01

    Positron Emission Mammography (PEM) imaging systems with the ability in detection of millimeter-sized tumors were developed in recent years. And some of them have been well used in clinical applications. In consideration of biopsy application, a double-plane detector configuration is practical for the convenience of breast immobilization. However, the serious blurring effect in the double-plane system with changeable spacing for different breast size should be studied. Methods: We study a high resolution reconstruction method applicable for a double-plane PET system with a changeable detector spacing. Geometric and blurring components should be calculated at real time for different detector distance. Accurate geometric sensitivity is obtained with a tube area model. Resolution recovery is achieved by estimating blurring effects derived from simulated single gamma response information. Results: The results show that the new geometric modeling gives a more finite and smooth sensitivity weight in double-plane sy...

  8. Blood perfusion in osteomyelitis studied with [O-15] water PET in a juvenile porcine model

    DEFF Research Database (Denmark)

    Jodal, Lars; Nielsen, Ole L.; Afzelius, Pia

    2017-01-01

    that perfusion will be less elevated in OM lesions than in soft tissue (ST) infection. The study comprised 11 juvenile pigs with haematogenous osteomyelitis induced by injection of Staphylococcus aureus into the right femoral artery 1 week before scanning (in one pig, 2 weeks). The pigs were dynamically PET...

  9. Efficient methodologies for system matrix modelling in iterative image reconstruction for rotating high-resolution PET

    Energy Technology Data Exchange (ETDEWEB)

    Ortuno, J E; Kontaxakis, G; Rubio, J L; Santos, A [Departamento de Ingenieria Electronica (DIE), Universidad Politecnica de Madrid, Ciudad Universitaria s/n, 28040 Madrid (Spain); Guerra, P [Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Madrid (Spain)], E-mail: juanen@die.upm.es

    2010-04-07

    A fully 3D iterative image reconstruction algorithm has been developed for high-resolution PET cameras composed of pixelated scintillator crystal arrays and rotating planar detectors, based on the ordered subsets approach. The associated system matrix is precalculated with Monte Carlo methods that incorporate physical effects not included in analytical models, such as positron range effects and interaction of the incident gammas with the scintillator material. Custom Monte Carlo methodologies have been developed and optimized for modelling of system matrices for fast iterative image reconstruction adapted to specific scanner geometries, without redundant calculations. According to the methodology proposed here, only one-eighth of the voxels within two central transaxial slices need to be modelled in detail. The rest of the system matrix elements can be obtained with the aid of axial symmetries and redundancies, as well as in-plane symmetries within transaxial slices. Sparse matrix techniques for the non-zero system matrix elements are employed, allowing for fast execution of the image reconstruction process. This 3D image reconstruction scheme has been compared in terms of image quality to a 2D fast implementation of the OSEM algorithm combined with Fourier rebinning approaches. This work confirms the superiority of fully 3D OSEM in terms of spatial resolution, contrast recovery and noise reduction as compared to conventional 2D approaches based on rebinning schemes. At the same time it demonstrates that fully 3D methodologies can be efficiently applied to the image reconstruction problem for high-resolution rotational PET cameras by applying accurate pre-calculated system models and taking advantage of the system's symmetries.

  10. Discrimination Between Brown and White Adipose Tissue Using a 2-Point Dixon Water-Fat Separation Method in Simultaneous PET/MRI.

    Science.gov (United States)

    Franz, Daniela; Karampinos, Dimitrios C; Rummeny, Ernst J; Souvatzoglou, Michael; Beer, Ambros J; Nekolla, Stephan G; Schwaiger, Markus; Eiber, Matthias

    2015-11-01

    The purpose of the study was to evaluate signal-fat-fraction (SFF) analysis based on a 2-point-Dixon water-fat separation method in whole-body simultaneous PET/MR imaging for identifying brown adipose tissue (BAT) and discriminating it from white adipose tissue (WAT) using cross-validation via PET. This retrospective, internal review board-approved study evaluated 66 PET/MR imaging examinations of 33 pediatric patients (mean age, 14.7 y; range, 7.4-21.4 y). Eleven elderly patients were evaluated as controls (mean age, 79.9 y; range, 76.3-88.6 y). Pediatric patients were divided into 2 groups: with and without metabolically active supraclavicular BAT. The standard of reference for the presence of BAT was at least 1 PET examination showing (18)F-FDG uptake. PET/MR imaging included a 2-point Dixon water-fat separation method. Signal intensities in regions of interest on fat and water images and mean standardized uptake values (SUVmean) were determined bilaterally in supraclavicular and gluteal fat depots. SFF was calculated from the ratio of fat signal over summed water and fat signal. Statistical analysis was conducted using the Student t test and correlation analysis. SFF was significantly lower (P analysis is a reproducible imaging modality for the detection of human BAT and discrimination from WAT. SFF values of BAT are independent from its metabolic activity, making SFF a more reliable parameter for BAT than the commonly used PET signal. However, with the intent to investigate both the composition of BAT and its activation status, hybrid PET/MR imaging might provide supplemental information. © 2015 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

  11. Learning Nuclear Chemistry through Practice: A High School Student Project Using PET in a Clinical Setting

    Science.gov (United States)

    Liguori, Lucia; Adamsen, Tom Christian Holm

    2013-01-01

    Practical experience is vital for promoting interest in science. Several aspects of chemistry are rarely taught in the secondary school curriculum, especially nuclear and radiochemistry. Therefore, we introduced radiochemistry to secondary school students through positron emission tomography (PET) associated with computer tomography (CT). PET-CT…

  12. The motivations and methodology for high-throughput PET imaging of small animals in cancer research.

    NARCIS (Netherlands)

    Aide, N.; Visser, E.P.; Lheureux, S.; Heutte, N.; Szanda, I.; Hicks, R.J.

    2012-01-01

    Over the last decade, small-animal PET imaging has become a vital platform technology in cancer research. With the development of molecularly targeted therapies and drug combinations requiring evaluation of different schedules, the number of animals to be imaged within a PET experiment has

  13. PET/MRI Imaging in High-Risk Sarcoma: First Findings and Solving Clinical Problems

    Directory of Open Access Journals (Sweden)

    Markus K. Schuler

    2013-01-01

    Full Text Available Simultaneous positron emission tomography (PET and magnetic resonance imaging (MRI is a new whole-body hybrid PET/MR imaging technique that combines metabolic and cross-sectional diagnostic imaging. Since the use of MRI in imaging of soft-tissue sarcoma is extremely beneficial, investigation of the combined PET/MRI is of great interest. In this paper, we present three cases and first data. Combined PET/MRI technique can support the process of clinical decision-making and give answers to some meaningful questions when treating patients with STS. Therefore, the combined modality of simultaneous PET/MRI offers new pieces to the puzzle of sarcoma treatment.

  14. Influence of Elevated Temperatures on Pet-Concrete Properties

    Science.gov (United States)

    Albano, C.; Camacho, N.; Hernández, M.; Matheus, A.; Gutiérrez, A.

    2008-08-01

    Lightweight aggregate is an important material in reducing the unit weight of concrete complying with special concrete structures of large high-rise buildings. Besides, the use of recycled PET bottles as lightweight aggregate in concrete is an effective contribution for environment preservation. So, the objective of the present work was to study experimentally the flexural strength of the PET -concrete blends and the thermal degradation of the PET in the concrete, when the blends with 10 and 20% in volume of PET were exposed to different temperatures (200, 400, 600 °C). The flexural strength of concrete-PET exposed to a heat source is strongly dependent on the temperature, water/cement ratio, as well as the content and particle size of PET. However, the activation energy is affected by the temperature, location of the PET particles on the slabs and the water/cement ratio. Higher water content originates thermal and hydrolytic degradation on the PET, while on the concrete, a higher vapor pressure which causes an increase in crack formation. The values of the activation energy are higher on the center of the slabs than on the surface, since concrete is a poor heat conductor.

  15. Designing a compact high performance brain PET scanner—simulation study

    Science.gov (United States)

    Gong, Kuang; Majewski, Stan; Kinahan, Paul E.; Harrison, Robert L.; Elston, Brian F.; Manjeshwar, Ravindra; Dolinsky, Sergei; Stolin, Alexander V.; Brefczynski-Lewis, Julie A.; Qi, Jinyi

    2016-05-01

    The desire to understand normal and disordered human brain function of upright, moving persons in natural environments motivates the development of the ambulatory micro-dose brain PET imager (AMPET). An ideal system would be light weight but with high sensitivity and spatial resolution, although these requirements are often in conflict with each other. One potential approach to meet the design goals is a compact brain-only imaging device with a head-sized aperture. However, a compact geometry increases parallax error in peripheral lines of response, which increases bias and variance in region of interest (ROI) quantification. Therefore, we performed simulation studies to search for the optimal system configuration and to evaluate the potential improvement in quantification performance over existing scanners. We used the Cramér-Rao variance bound to compare the performance for ROI quantification using different scanner geometries. The results show that while a smaller ring diameter can increase photon detection sensitivity and hence reduce the variance at the center of the field of view, it can also result in higher variance in peripheral regions when the length of detector crystal is 15 mm or more. This variance can be substantially reduced by adding depth-of-interaction (DOI) measurement capability to the detector modules. Our simulation study also shows that the relative performance depends on the size of the ROI, and a large ROI favors a compact geometry even without DOI information. Based on these results, we propose a compact ‘helmet’ design using detectors with DOI capability. Monte Carlo simulations show the helmet design can achieve four-fold higher sensitivity and resolve smaller features than existing cylindrical brain PET scanners. The simulations also suggest that improving TOF timing resolution from 400 ps to 200 ps also results in noticeable improvement in image quality, indicating better timing resolution is desirable for brain imaging.

  16. First results of a highly granulated 3D CdTe detector module for PET

    Science.gov (United States)

    Chmeissani, Mokhtar; Kolstein, Machiel; Macias-Montero, José Gabriel; Puigdengoles, Carles; García, Jorge; Prats, Xavier; Martínez, Ricardo

    2018-01-01

    We present the performance of a highly granulated 3D detector module for PET, consisting of a stack of pixelated CdTe detectors. Each detector module has 2 cm  ×  2 cm  ×  2 cm of CdTe material, subdivided into 4000 voxels, where each voxel has size 1 mm  ×  1 mm  ×  2 mm and is connected to its own read-out electronics via a BiSn solder ball. Each read-out channel consists of a preamp, a discriminator, a shaper, a peak-and-hold circuit and a 10 bits SAR ADC. The preamp has variable gain where at the maximum gain the ADC resolution is equivalent to 0.7 keV. Each ASIC chip reads 100 CdTe pixel channels and has one TDC to measure the time stamp of the triggered events, with a time resolution of less than 1 ns. With the bias voltage set at  ‑250 V mm‑1 and for 17838 working channels out of a total of 20 000, we have obtained an average energy resolution of 2.2% FWHM for 511 keV photons. For 511 keV photons that have undergone Compton scattering, we measured an energy resolution of 3.2% FWHM. A timing resolution for PET coincidence events of 60 ns FWHM was found.

  17. Prospective evaluation of 18F-FACBC PET/CT and PET/MRI versus multiparametric MRI in intermediate- to high-risk prostate cancer patients (FLUCIPRO trial).

    Science.gov (United States)

    Jambor, Ivan; Kuisma, Anna; Kähkönen, Esa; Kemppainen, Jukka; Merisaari, Harri; Eskola, Olli; Teuho, Jarmo; Perez, Ileana Montoya; Pesola, Marko; Aronen, Hannu J; Boström, Peter J; Taimen, Pekka; Minn, Heikki

    2018-03-01

    The purpose of this study was to evaluate 18F-FACBC PET/CT, PET/MRI, and multiparametric MRI (mpMRI) in detection of primary prostate cancer (PCa). Twenty-six men with histologically confirmed PCa underwent PET/CT immediately after injection of 369 ± 10 MBq 18F-FACBC (fluciclovine) followed by PET/MRI started 55 ± 7 min from injection. Maximum standardized uptake values (SUVmax) were measured for both hybrid PET acquisitions. A separate mpMRI was acquired within a week of the PET scans. Logan plots were used to calculate volume of distribution (VT). The presence of PCa was estimated in 12 regions with radical prostatectomy findings as ground truth. For each imaging modality, area under the curve (AUC) for detection of PCa was determined to predict diagnostic performance. The clinical trial registration number is NCT02002455. In the visual analysis, 164/312 (53%) regions contained PCa, and 41 tumor foci were identified. PET/CT demonstrated the highest sensitivity at 87% while its specificity was low at 56%. The AUC of both PET/MRI and mpMRI significantly (p PET/CT while no differences were detected between PET/MRI and mpMRI. SUVmax and VT of Gleason score (GS) >3 + 4 tumors were significantly (p evaluable for staging, and PET/CT and PET/MRI demonstrated true-positive findings in only 1/7 patients with metastatic lymph nodes. Quantitative 18F-FACBC imaging significantly correlated with GS but failed to outperform MRI in lesion detection. 18F-FACBC may assist in targeted biopsies in the setting of hybrid imaging with MRI.

  18. PET and Recycling

    Directory of Open Access Journals (Sweden)

    Funda Sevencan

    2007-08-01

    Full Text Available This review aims to clarify the need of decreasing the environmental effects caused by human and draw attention to the increasing environmental effects of plastics wastes. Plastics consist of organic molecules with high density molecules or polymers. Main resources of plastics are the residue of oil rafineries. Several advantages of plastics, have increased the usage continuously. Polyethylene Terephthalate (PET is the most commonly used plastics. PET is used to protect food, drinking water, fruit juice, alcoholic beverage, and food packing films. By the increasing interest on the environmental effects of plastic wastes, concerns on the recyclable packing materials also grew up. Also the daily use of recyclable containers consisting PET have increased. There are five steps for recycling of plastics. These steps are; using large amounts of plastics, collecting them in a big center, classifying and sorting the plastics, reproducing the polymers and obtaining new products with melted plastics. Providing a healthy recycling of plastics, the consumers should have knowledge and responsibility. The consumer should know what he/she has to do before putting the plastics in the recycling containers. Recycling containers and bags should be placed near the sources of plastic wastes. Consequently, the plastic wastes and environmental problems they cause will be on the agenda in future. [TAF Prev Med Bull. 2007; 6(4: 307-312

  19. PET and Recycling

    Directory of Open Access Journals (Sweden)

    Funda Sevencan

    2007-08-01

    Full Text Available This review aims to clarify the need of decreasing the environmental effects caused by human and draw attention to the increasing environmental effects of plastics wastes. Plastics consist of organic molecules with high density molecules or polymers. Main resources of plastics are the residue of oil rafineries. Several advantages of plastics, have increased the usage continuously. Polyethylene Terephthalate (PET is the most commonly used plastics. PET is used to protect food, drinking water, fruit juice, alcoholic beverage, and food packing films. By the increasing interest on the environmental effects of plastic wastes, concerns on the recyclable packing materials also grew up. Also the daily use of recyclable containers consisting PET have increased. There are five steps for recycling of plastics. These steps are; using large amounts of plastics, collecting them in a big center, classifying and sorting the plastics, reproducing the polymers and obtaining new products with melted plastics. Providing a healthy recycling of plastics, the consumers should have knowledge and responsibility. The consumer should know what he/she has to do before putting the plastics in the recycling containers. Recycling containers and bags should be placed near the sources of plastic wastes. Consequently, the plastic wastes and environmental problems they cause will be on the agenda in future. [TAF Prev Med Bull 2007; 6(4.000: 307-312

  20. Methods for the correction of vascular artifacts in PET O-15 water brain-mapping studies

    Energy Technology Data Exchange (ETDEWEB)

    Chen, K.; Reiman, E.M. [Univ. of Arizona, Tucson, AZ (United States)]|[Good Samaritan Regional Medical Center, Phoenix, AZ (United States). PET Center; Lawson, M.; Yun, L.S.; Bandy, D. [Good Samaritan Regional Medical Center, Phoenix, AZ (United States). PET Center

    1996-12-01

    While positron emission tomographic (PET) measurements of regional cerebral blood flow (rCBF) can be used to map brain regions that are involved in normal and pathological human behaviors, measurements in the anteromedial temporal lobe can be confounded by the combined effects of radiotracer activity in neighboring arteries and partial-volume averaging. The authors now describe two simple methods to address this vascular artifact. One method utilizes the early frames of a dynamic PET study, while the other method utilizes a coregistered magnetic resonance image (MRI) to characterize the vascular region of interest (VROI). Both methods subsequently assign a common value to each pixel in the VROI for the control scan and the activation scan. To study the vascular artifact and to demonstrate the ability of the proposed methods correcting the vascular artifact, four dynamic PET scans were performed in a single subject during the same behavioral state. For each of the four scans, a vascular scan containing vascular activity was computed as the summation of the images acquired 0--60 s after radiotracer administrations, and a control scan containing minimal vascular activity was computed as the summation of the images acquired 20--80 s after radiotracer administration. t-score maps calculated from the four pairs of vascular and control scans were used to characterize regional blood flow differences related to vascular activity before and after the applications of each vascular artifact correction method. Both methods eliminated the observed differences in vascular activity, as well as the vascular artifact observed in the anteromedial temporal lobes. Using PET data from a study of normal human emotion, these methods permitted us to identify rCBF increases in the anteromedial temporal lobe free from the potentially confounding, combined effects of vascular activity and partial-volume averaging.

  1. Development of PDT/PET Theranostics: Synthesis and Biological Evaluation of an (18)F-Radiolabeled Water-Soluble Porphyrin.

    Science.gov (United States)

    Entract, Guy M; Bryden, Francesca; Domarkas, Juozas; Savoie, Huguette; Allott, Louis; Archibald, Stephen J; Cawthorne, Chris; Boyle, Ross W

    2015-12-07

    Synthesis of the first water-soluble porphyrin radiolabeled with fluorine-18 is described: a new molecular theranostic agent which integrates the therapeutic selectivity of photodynamic therapy (PDT) with the imaging efficacy of positron emission tomography (PET). Generation of the theranostic was carried out through the conjugation of a cationic water-soluble porphyrin bearing an azide functionality to a fluorine-18 radiolabeled prosthetic bearing an alkyne functionality through click conjugation, with excellent yields obtained in both cold and hot synthesis. Biological evaluation of the synthesized structures shows the first example of an (18)F-radiolabeled porphyrin retaining photocytotoxicity following radiolabeling and demonstrable conjugate uptake and potential application as a radiotracer in vivo. The promising results gained from biological evaluation demonstrate the potential of this structure as a clinically relevant theranostic agent, offering exciting possibilities for the simultaneous imaging and photodynamic treatment of tumors.

  2. Self-consolidating concretes containing waste PET bottles as sand replacement

    Science.gov (United States)

    Khalid, Faisal Sheikh; Azmi, Nurul Bazilah; Mazenan, Puteri Natasya; Shahidan, Shahiron; Othman, Nor hazurina; Guntor, Nickholas Anting Anak

    2018-02-01

    This study evaluates the effect of self-consolidating concrete (SCC) containing waste polyethylene terephthalate (PET) granules on the fresh, mechanical and water absorption properties. Fine aggregates were replaced from 0% to 8% by PET granules. The fresh properties of SCC containing PET granules were determined using slump flow and V-funnel flow time tests. The compressive and splitting tensile strength were evaluated. The results indicated that utilization of waste PET granules in production of SCC could be an effective way for recycling purpose. The maximum amount of PET replacement should be limited to 5%. Exceeding 5% of PET content may result in an increase of V-funnel flow time to overpass the limiting value, decrease in strength. The production of high performance SCC containing 5% PET granules satisfies all the requirements for SCC with satisfactory outputs.

  3. Tiny Turtles Purchased at Pet Stores are a Potential High Risk for Salmonella Human Infection in the Valencian Region, Eastern Spain.

    Science.gov (United States)

    Marin, Clara; Vega, Santiago; Marco-Jiménez, Francisco

    2016-07-01

    Turtles may be considered unsafe pets, particularly in households with children. This study aimed to assess Salmonella carriage by turtles in pet stores and in private ownership to inform the public of the potential health risk, enabling informed choices around pet selection. During the period between September and October 2013, 24 pet stores and 96 private owners were sampled in the Valencian Region (Eastern Spain). Salmonella identification procedure was based on ISO 6579: 2002 recommendations (Annex D). Salmonella strains were serotyped in accordance with Kauffman-White-Le-Minor technique. The rate of isolation of Salmonella was very high from pet store samples (75.0% ± 8.8%) and moderate for private owners (29.0% ± 4.6%). Serotyping revealed 18 different serotypes among two Salmonella enterica subspecies: S. enterica subsp. enterica and S. enterica subsp. diarizonae. Most frequently isolated serotypes were Salmonella Typhimurium (39.5%, 17/43) and Salmonella Pomona (9.3%, 4/43). Serotypes identified have previously been reported in turtles, and child Salmonella infections associate with pet turtle exposure. The present study clearly demonstrates that turtles in pet stores, as well as in private owners, could be a direct or indirect source of a high risk of human Salmonella infections. In addition, pet stores should advise their customers of the potential risks associated with reptile ownership.

  4. A High-Resolution PET Demonstrator using a Silicon “Magnifying Glass”

    OpenAIRE

    Clinthorne, Neal; Cochran, Eric; Chesi, Enrico; Grkovski, Milan; Grošičar, Borut; Honscheid, Klaus; Huh, Sam S.; Kagan, Harris; Lacasta, Carlos; Brzezinski, Karol; Linhart, Vladimir; Mikuž, Marko; Smith, D Shane; Stankova, Vera; Studen, Andrej

    2012-01-01

    To assist ongoing investigations of the limits of the tradeoff between spatial resolution and noise in PET imaging, several PET instruments based on silicon-pad detectors have been developed. The latest is a segment of a dual-ring device to demonstrate that excellent reconstructed image resolution can be achieved with a scanner that uses highresolution detectors placed close to the object of interest or surrounding a small field-of-view in combination with detectors having modest resolution a...

  5. The motivations and methodology for high-throughput PET imaging of small animals in cancer research

    OpenAIRE

    Aide, Nicolas; Visser, Eric P.; Lheureux, Stéphanie; Heutte, Natacha; Szanda, Istvan; Hicks, Rodney J.

    2012-01-01

    Over the last decade, small-animal PET imaging has become a vital platform technology in cancer research. With the development of molecularly targeted therapies and drug combinations requiring evaluation of different schedules, the number of animals to be imaged within a PET experiment has increased. This paper describes experimental design requirements to reach statistical significance, based on the expected change in tracer uptake in treated animals as compared to the control group, the num...

  6. Highly porous oil sorbent based on hollow fibers as the interceptor for oil on static and running water

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Ting [College of Textiles, Donghua University, Shanghai 201620 (China); Cao, Shengbin [College of Textiles, Donghua University, Shanghai 201620 (China); School of Mechanical Engineering, Shanghai Dianji University, Shanghai 201306 (China); Xu, Guangbiao, E-mail: guangbiao_xu@dhu.edu.cn [College of Textiles, Donghua University, Shanghai 201620 (China); Key Laboratory of Textile Science and Technology Ministry of Education, Donghua University, Shanghai 201620 (China)

    2016-03-15

    Highlights: • Highly porous sorbent was made up of kapok and PET fibers. • The sorbent was prepared by air-laying-bonding method. • The sorbent showed much higher oil sorption capacity than 100% loose kapok fibers. • The sorbent showed high intercepting efficiency to oils on water. • The runing of water significantly accelerated the oil leakage. - Abstract: Highly porous fibrous assembly made by kapok and hollow PET fibers was prepared by the air-laying-bonding method, and used as the interceptor for oils on static and running water. SEM showed that the vast majority of kapok and PET fibers in the assembly was intact and retained their hollow lumens, with the assembly's porosity high to 98.03%. Oil sorption tests exhibited that kapok/PET assembly could absorb 63.00 g/g of vegetable oil and 58.50 g/g of used motor oil, with high oil retention after 24 h dripping. In static condition of oil interception, the two oils started to leak at around 20 min for 10-mm thick kapok/PET wall. The time for that was prolonged with increasing the thickness of kapok/PET wall. After oil breakthrough, continuous oil leaking took place. The typical leakage was divided into three stages in which oils leaked separately in sharply increased rate, reduced rate and finally gently. In running condition, oils leaked in markedly quicker way than that in static condition, with initial leakage of oils shortened to less 6 min when the water ran at 60.35 ml/s. The leakage of oils was considerably accelerated with increasing running rates.

  7. The clinical impact of 18F-FDG PET/CT to detect suspicious recurred thyroid cancer with differentiated type before high dose radioactive iodine therapy

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Bom Sahn; Kang, Won Jun; Lee, Dong Soo; Chang, June Key; Lee, Myung Chul [Seoul National Univ. College of Medicine, Seoul (Korea, Republic of)

    2007-07-01

    The purpose of this study was to evaluate the usefulness of 18F-FDG PET/CT (PET/CT) in suspicious recurred thyroid cancer before high dose of radioactive iodine therapy (RAI therapy). PET/CT was performed after injecting 370-555MBq of 18F-FDG in 23 patients prior to RAI therapy. RAI therapy (212 58 mCi) was performed, and thyroglobulin (Tg) and anti-thyroglobulin antibody (anti-TG ab) during TSH stimulation was measured. The interval between PET/CT and RAI scan was 41 50 day. 15 patients were confirmed as recurred thyroid cancer (pathologic diagnosis: 10), whereas 8 patients were diagnosed as remission status (pathologic diagnosis: 3). PET/CT had 80.0% (12/15) of sensitivity and 75.0% (6/8) of specificity. TG and RAI scan had 80.0% (12/15) and 75% (6/8), 80% (12/15) and 37.5% (3/8) of sensitivity and specificity, respectively. Combination of PET/CT and TG increased the sensitivity (93.3%; 14/15) and specificity (87.5%; 7/8). There was 25 suspicious lesions (19 malignant lesion, 6 benign lesion) in lesion-based study. PET/CT had 84.5% and 83.3% of sensitivity and specificity but RAI scan had 89.5% and 16.7%, respectively. Five false positive sites of RAI scan were diagnosed as fungus ball of lung, calcified mediastinal LN, and post op induced change such as suture granuloma. PET/CT revealed 80% (3/5) of them as benign lesions. Even though PET/CT had similar sensitivity with high dose of RAI scan, it had a better discriminating nature to detect benign lesion. We could diminish the unnecessary high dose of RAI therapy using FDG PET/CT.

  8. dPeak: High Resolution Identification of Transcription Factor Binding Sites from PET and SET ChIP-Seq Data

    Science.gov (United States)

    Chung, Dongjun; Park, Dan; Myers, Kevin; Grass, Jeffrey; Kiley, Patricia; Landick, Robert; Keleş, Sündüz

    2013-01-01

    Chromatin immunoprecipitation followed by high throughput sequencing (ChIP-Seq) has been successfully used for genome-wide profiling of transcription factor binding sites, histone modifications, and nucleosome occupancy in many model organisms and humans. Because the compact genomes of prokaryotes harbor many binding sites separated by only few base pairs, applications of ChIP-Seq in this domain have not reached their full potential. Applications in prokaryotic genomes are further hampered by the fact that well studied data analysis methods for ChIP-Seq do not result in a resolution required for deciphering the locations of nearby binding events. We generated single-end tag (SET) and paired-end tag (PET) ChIP-Seq data for factor in Escherichia coli (E. coli). Direct comparison of these datasets revealed that although PET assay enables higher resolution identification of binding events, standard ChIP-Seq analysis methods are not equipped to utilize PET-specific features of the data. To address this problem, we developed dPeak as a high resolution binding site identification (deconvolution) algorithm. dPeak implements a probabilistic model that accurately describes ChIP-Seq data generation process for both the SET and PET assays. For SET data, dPeak outperforms or performs comparably to the state-of-the-art high-resolution ChIP-Seq peak deconvolution algorithms such as PICS, GPS, and GEM. When coupled with PET data, dPeak significantly outperforms SET-based analysis with any of the current state-of-the-art methods. Experimental validations of a subset of dPeak predictions from PET ChIP-Seq data indicate that dPeak can estimate locations of binding events with as high as to resolution. Applications of dPeak to ChIP-Seq data in E. coli under aerobic and anaerobic conditions reveal closely located promoters that are differentially occupied and further illustrate the importance of high resolution analysis of ChIP-Seq data. PMID:24146601

  9. Discrimination Between Brown and White Adipose Tissue Using a 2-Point Dixon Water-Fat Separation Method in Simultaneous PET/MRI

    National Research Council Canada - National Science Library

    Franz, Daniela; Karampinos, Dimitrios C; Rummeny, Ernst J; Souvatzoglou, Michael; Beer, Ambros J; Nekolla, Stephan G; Schwaiger, Markus; Eiber, Matthias

    2015-01-01

    The purpose of the study was to evaluate signal-fat-fraction (SFF) analysis based on a 2-point-Dixon water-fat separation method in whole-body simultaneous PET/MR imaging for identifying brown adipose tissue (BAT...

  10. A preliminary Ames fluctuation assay assessment of the genotoxicity of drinking water that has been solar disinfected in polyethylene terephthalate (PET) bottles.

    Science.gov (United States)

    Ubomba-Jaswa, Eunice; Fernández-Ibáñez, Pilar; McGuigan, Kevin G

    2010-12-01

    Though microbially safe, concerns have been raised about the genotoxic/mutagenic quality of solar-disinfected drinking water, which might be compromised as a result of photodegradation of polyethylene terephthalate (PET) bottles used as SODIS reactors. This study assessed genotoxic risk associated with the possible release of genotoxic compounds into water from PET bottles during SODIS, using the Ames fluctuation test. Negative genotoxicity results were obtained for water samples that had been in PET bottles and exposed to normal SODIS conditions (strong natural sunlight) over 6 months. Under SODIS conditions, bottles were exposed to 6 h of sunlight, followed by overnight room temperature storage. They were then emptied and refilled the following day and exposed to sunlight again. Genotoxicity was detected after 2 months in water stored in PET bottles and exposed continuously (without refilling) to sunlight for a period ranging from 1 to 6 months. However, similar genotoxicity results were also observed for the dark control (without refill) samples at the same time-point and in no other samples after that time; therefore it is unlikely that this genotoxicity event is related to solar exposure.

  11. Investigation of the limitations of the highly pixilated CdZnTe detector for PET applications.

    Science.gov (United States)

    Komarov, Sergey; Yin, Yongzhi; Wu, Heyu; Wen, Jie; Krawczynski, Henric; Meng, Ling-Jian; Tai, Yuan-Chuan

    2012-11-21

    We are investigating the feasibility of a high resolution positron emission tomography (PET) insert device based on the CdZnTe detector with 350 µm anode pixel pitch to be integrated into a conventional animal PET scanner to improve its image resolution. In this paper, we have used a simplified version of the multi pixel CdZnTe planar detector, 5 mm thick with 9 anode pixels only. This simplified 9 anode pixel structure makes it possible to carry out experiments without a complete application-specific integrated circuits readout system that is still under development. Special attention was paid to the double pixel (or charge sharing) detections. The following characteristics were obtained in experiment: energy resolution full-width-at-half-maximum (FWHM) is 7% for single pixel and 9% for double pixel photoelectric detections of 511 keV gammas; timing resolution (FWHM) from the anode signals is 30 ns for single pixel and 35 ns for double pixel detections (for photoelectric interactions only the corresponding values are 20 and 25 ns); position resolution is 350 µm in x,y-plane and ∼0.4 mm in depth-of-interaction. The experimental measurements were accompanied by Monte Carlo (MC) simulations to find a limitation imposed by spatial charge distribution. Results from MC simulations suggest the limitation of the intrinsic spatial resolution of the CdZnTe detector for 511 keV photoelectric interactions is 170 µm. The interpixel interpolation cannot recover the resolution beyond the limit mentioned above for photoelectric interactions. However, it is possible to achieve higher spatial resolution using interpolation for Compton scattered events. Energy and timing resolution of the proposed 350 µm anode pixel pitch detector is no better than 0.6% FWHM at 511 keV, and 2 ns FWHM, respectively. These MC results should be used as a guide to understand the performance limits of the pixelated CdZnTe detector due to the underlying detection processes, with the understanding of

  12. High Contrast PET Imaging of GRPR Expression in Prostate Cancer Using Cobalt-Labeled Bombesin Antagonist RM26

    Directory of Open Access Journals (Sweden)

    Bogdan Mitran

    2017-01-01

    Full Text Available High gastrin releasing peptide receptor (GRPR expression is associated with numerous cancers including prostate and breast cancer. The aim of the current study was to develop a 55Co-labeled PET agent based on GRPR antagonist RM26 for visualization of GRPR-expressing tumors. Labeling with 57Co and 55Co, stability, binding specificity, and in vitro and in vivo characteristics of 57Co-NOTA-PEG2-RM26 were studied. NOTA-PEG2-RM26 was successfully radiolabeled with 57Co and 55Co with high yields and demonstrated high stability. The radiopeptide showed retained binding specificity to GRPR in vitro and in vivo. 57Co-NOTA-PEG2-RM26 biodistribution in mice was characterized by rapid clearance of radioactivity from blood and normal non-GRPR-expressing organs and low hepatic uptake. The clearance was predominantly renal with a low degree of radioactivity reabsorption. Tumor-to-blood ratios were approximately 200 (3 h pi and 1000 (24 h pi. The favorable biodistribution of cobalt-labeled NOTA-PEG2-RM26 translated into high contrast preclinical PET/CT (using 55Co and SPECT/CT (using 57Co images of PC-3 xenografts. The initial biological results suggest that 55Co-NOTA-PEG2-RM26 is a promising tracer for PET visualization of GRPR-expressing tumors.

  13. Convex optimization of coincidence time resolution for a high-resolution PET system.

    Science.gov (United States)

    Reynolds, Paul D; Olcott, Peter D; Pratx, Guillem; Lau, Frances W Y; Levin, Craig S

    2011-02-01

    We are developing a dual panel breast-dedicated positron emission tomography (PET) system using LSO scintillators coupled to position sensitive avalanche photodiodes (PSAPD). The charge output is amplified and read using NOVA RENA-3 ASICs. This paper shows that the coincidence timing resolution of the RENA-3 ASIC can be improved using certain list-mode calibrations. We treat the calibration problem as a convex optimization problem and use the RENA-3's analog-based timing system to correct the measured data for time dispersion effects from correlated noise, PSAPD signal delays and varying signal amplitudes. The direct solution to the optimization problem involves a matrix inversion that grows order (n(3)) with the number of parameters. An iterative method using single-coordinate descent to approximate the inversion grows order (n). The inversion does not need to run to convergence, since any gains at high iteration number will be low compared to noise amplification. The system calibration method is demonstrated with measured pulser data as well as with two LSO-PSAPD detectors in electronic coincidence. After applying the algorithm, the 511 keV photopeak paired coincidence time resolution from the LSO-PSAPD detectors under study improved by 57%, from the raw value of 16.3 ±0.07 ns full-width at half-maximum (FWHM) to 6.92 ±0.02 ns FWHM ( 11.52 ±0.05 ns to 4.89 ±0.02 ns for unpaired photons).

  14. Optimization of high filler loading on tensile properties of recycled HDPE/PET blends filled with rice husk

    Science.gov (United States)

    Chen, Ruey Shan; Ahmad, Sahrim; Ghani, Mohd Hafizuddin Ab; Salleh, Mohd Nazry

    2014-09-01

    Biocomposites of recycled high density polyethylene / recycled polyethylene terephthalate (rHDPE/rPET) blend incorporated with rice husk flour (RHF) were prepared using a corotating twin screw extruder. Maleic anhydride polyethylene (MAPE) was added as a coupling agent to improve the fibre-matrix interface adhesion. The effect of high filler loadings (50-90 wt%) on morphology and tensile properties of compatibilized rHDPE/rPET blend was investigated. The results of our study shown that composite with 70 wt% exhibited the highest tensile strength and Young's modulus, which are 22 MPa and 1752 MPa, respectively. The elongation at break decreased with increasing percentage of RHF. SEM micrograph confirmed fillers dispersion, morphological interaction and enhanced interfacial bonding between recycled polymer blends and rice husk. It can be concluded that the optimum RHF content is 70 wt% with maximum tensile strength.

  15. Evaluation of Dixon Sequence on Hybrid PET/MR Compared with Contrast-Enhanced PET/CT for PET-Positive Lesions

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Ju Hye; Cho, Ihn Ho; Kong, Eun Jung; Chun, Kyung Ah [Yeungnam Univ. Hospital, Daegu (Korea, Republic of)

    2014-03-15

    Hybrid positron emission tomography and magnetic resonance (PET/MR) imaging performs a two-point Dixon MR sequence for attenuation correction. However, MR data in hybrid PET/MR should provide anatomic and morphologic information as well as an attenuation map. We evaluated the Dixon sequence of hybrid PET/MR for anatomic correlation of PET-positive lesions compared with contrast-enhanced PET/computed tomography (CT) in patients with oncologic diseases. Twelve patients underwent a single injection, dual imaging protocol. PET/CT was performed with an intravenous contrast agent (85±13 min after {sup 18}F-FDG injection of 403± 45 MBq) and then (125±19 min after injection) PET/MR was performed. Attenuation correction and anatomic allocation of PET were performed using contrast-enhanced CT for PET/CT and Dixon MR sequence for hybrid PET/MR. The Dixon MR sequence and contrast-enhanced CT were compared for anatomic correlation of PET-positive lesions (scoring scale ranging from 0 to 3 for visual ratings). Additionally, standardized uptake values (SUVs) for the detected lesions were assessed for quantitative comparison. Both hybrid PET/MR and contrast-enhanced PET/CT identified 55 lesions with increased FDG uptake in ten patients. In total, 28 lymph nodes, 11 bone lesions, 3 dermal nodules, 3 pleural thickening lesions, 2 thyroid nodules, 1 pancreas, 1 liver, 1 ovary, 1 uterus, 1 breast, 1 soft tissue and 2 lung lesions were present. The best performance was observed for anatomic correlation of PET findings by the contrast-enhanced CT scans (contrast-enhanced CT, 2.64± 0.70; in-phase, 1.29±1.01; opposed-phase, 1.29±1.15; water-weighted, 1.71±1.07; fat weighted, 0.56±1.03). A significant difference was observed between the scores obtained from the contrast-enhanced CT and all four coregistered Dixon MR images. Quantitative evaluation revealed a high correlation between the SUVs measured with hybrid PET/MR (SUVmean, 2.63±1.62; SUVmax, 4.30±2.88) and contrast

  16. A High-Resolution Time-of-Flight Clinical PET Detection System Using a Gapless PMT-Quadrant-Sharing Method

    Science.gov (United States)

    Wong, Wai-Hoi; Li, Hongdi; Zhang, Yuxuan; Ramirez, Rocio; An, Shaohui; Wang, Chao; Liu, Shitao; Dong, Yun; Baghaei, Hossain

    2015-10-01

    We developed a high-resolution Photomultiplier-Quadrant-Sharing (PQS) PET system for human imaging. This system is made up of 24 detector panels. Each panel (bank) consists of 3 ×7 detector blocks, and each block has 16 ×16 LYSO crystals of 2.35 ×2.35 ×15.2 mm3. We used a novel detector-grinding scheme that is compatible with the PQS detector-pixel-decoding requirements to make a gapless cylindrical detector ring for maximizing detection efficiency while delivering an ultrahigh spatial-resolution for a whole-body PET camera with a ring diameter of 87 cm and axial field of view of 27.6 cm. This grinding scheme enables two adjacent gapless panels to share one row of the PMTs to extend the PQS configuration beyond one panel and thus maximize the economic benefit (in PMT usage) of the PQS design. The entire detector ring has 129,024 crystals, all of which are clearly decoded using only 576 PMTs (38-mm diameter). Thus, each PMT on average decodes 224 crystals to achieve a high crystal-pitch resolution of 2.44 mm ×2.44 mm. The detector blocks were mass-produced with our slab-sandwich-slice technique using a set of optimized mirror-film patterns (between crystals) to maximize light output and achieve high spatial and timing resolution. This detection system with time-of-flight capability was placed in a human PET/CT gantry. The reconstructed image resolution of the system was about 2.87 mm using 2D-filtered back-projection. The time-of-flight resolution was 473 ps. The preliminary images of phantoms and clinical studies presented in this work demonstrate the capability of this new PET/CT system to produce high-quality images.

  17. SUVmax of 18FDG PET/CT as a predictor of high-risk endometrial cancer patients

    DEFF Research Database (Denmark)

    Antonsen, Sofie Leisby; Loft, Annika; Fisker, Rune Vincents

    2013-01-01

    OBJECTIVE: To evaluate SUVmax in the assessment of endometrial cancer preoperatively with particular focus on myometrial invasion (MI), cervical invasion (CI), FIGO stage, risk-stratification and lymph node metastases (LNM). METHODS: A total of 268 women with endometrial cancer or atypical...... endometrial hyperplasia underwent FDG PET/CT imaging before surgical treatment. SUVmax of the primary tumour was compared with histological prognostic factors. RESULTS: SUVmax was significantly higher in patients with high FIGO stages (p...

  18. High performance hydrophilic pervaporation composite membranes for water desalination

    KAUST Repository

    Liang, Bin

    2014-08-01

    A three-layer thin film nanofibrous pervaporation composite (TFNPVC) membrane was prepared by sequential deposition using electrospraying/electrospinning. The poly(vinyl alcohol) (PVA) top barrier layer was first electrosprayed on aluminum foil and its thickness can be easily controlled by adjusting the collecting time. Next a polyacrylonitrile (PAN) nanofibrous scaffold was deposited by electrospinning as a mid-layer support. A nonwoven PET layer is used to complete the composite membrane. The pervaporation desalination performance of TFNPVC membranes was tested using NaCl solutions at 100. Pa and at room temperature. The TFNPVC membranes show excellent desalination performance (high water flux and salt rejection >. 99.5%) for different salt concentrations with virtually no change in performance after 50. h of operation. © 2014 Elsevier B.V.

  19. Treatment response evaluation with {sup 18}F-FDG PET/CT and {sup 18}F-NaF PET/CT in multiple myeloma patients undergoing high-dose chemotherapy and autologous stem cell transplantation

    Energy Technology Data Exchange (ETDEWEB)

    Sachpekidis, Christos [German Cancer Research Center (DKFZ), Medical PET Group-Biological Imaging, Clinical Cooperation Unit Nuclear Medicine, Heidelberg (Germany); University of Bern, Department of Nuclear Medicine, Inselspital, Bern University Hospital, Bern (Switzerland); Hillengass, J.; Wagner, B. [University Hospital Heidelberg, Department of Internal Medicine V, Heidelberg (Germany); Goldschmidt, H. [University Hospital Heidelberg, Department of Internal Medicine V, Heidelberg (Germany); National Center for Tumor Diseases (NCT) Heidelberg, Heidelberg (Germany); Haberkorn, U. [German Cancer Research Center (DKFZ), Medical PET Group-Biological Imaging, Clinical Cooperation Unit Nuclear Medicine, Heidelberg (Germany); University of Heidelberg, Department of Nuclear Medicine, Heidelberg (Germany); Kopka, K. [German Cancer Research Center (DKFZ), Department of Radiopharmaceutical Chemistry, Heidelberg (Germany); Dimitrakopoulou-Strauss, A. [German Cancer Research Center (DKFZ), Medical PET Group-Biological Imaging, Clinical Cooperation Unit Nuclear Medicine, Heidelberg (Germany)

    2017-01-15

    The aim of this study was to assess the combined use of the radiotracers {sup 18}F-FDG and {sup 18}F-NaF in treatment response evaluation of a group of multiple myeloma (MM) patients undergoing high-dose chemotherapy (HDT) followed by autologous stem cell transplantation (ASCT) by means of static (whole-body) and dynamic PET/CT (dPET/CT). Thirty-four patients with primary, previously untreated MM scheduled for treatment with HDT followed by ASCT were enrolled in the study. All patients underwent PET/CT scanning with {sup 18}F-FDG and {sup 18}F-NaF before and after therapy. Treatment response by means of PET/CT was assessed according to the European Organization for Research and Treatment of Cancer (EORTC) 1999 criteria. The evaluation of dPET/CT studies was based on qualitative evaluation, semi-quantitative (SUV) calculation, and quantitative analysis based on two-tissue compartment modelling and a non-compartmental approach leading to the extraction of fractal dimension (FD). An analysis was possible in 29 patients: three with clinical complete response (CR) and 26 with non-CR (13 patients near complete response-nCR, four patients very good partial response-VGPR, nine patients partial response-PR). After treatment, {sup 18}F-FDG PET/CT was negative in 14/29 patients and positive in 15/29 patients, showing a sensitivity of 57.5 % and a specificity of 100 %. According to the EORTC 1999 criteria, {sup 18}F-FDG PET/CT-based treatment response revealed CR in 14 patients ({sup 18}F-FDG PET/CT CR), PR in 11 patients ({sup 18}F-FDG PET/CT PR) and progressive disease in four patients ({sup 18}F-FDG PET/CT PD). In terms of {sup 18}F-NaF PET/CT, 4/29 patients (13.8 %) had a negative baseline scan, thus failed to depict MM. Regarding the patients for which a direct lesion-to-lesion comparison was feasible, {sup 18}F-NaF PET/CT depicted 56 of the 129 {sup 18}F-FDG positive lesions (43 %). Follow-up {sup 18}F-NaF PET/CT showed persistence of 81.5 % of the baseline {sup 18}F

  20. Effect of PET functionalization in composites of

    Directory of Open Access Journals (Sweden)

    Cristina Cazan

    2017-03-01

    Full Text Available The functionalization of polyethylene terephthalate (PET from tire rubber–PET–high density polyethylene (HDPE composites represents a key strategy for improving the composite properties. This is a practical and effective method to improve the interface between matrix (waste tire rubber and fillers (waste PET and HDPE. By PET functionalization, adherence and surface properties of composite materials can be controlled. PET functionalization was performed with polyethylene glycol (PEG 400, 1% and sodium dodecyl sulphate (SDS 1%. The characterization of the components and composite are discussed in terms of surface energy values (evaluated from water contact angle measurements and surface morphology by using scanning electron microscopy (SEM. The structural and conformational changes were investigated by Fourier Transform Infrared (FTIR Spectroscopy while the crystalline structure was studied by X-ray diffraction (XRD. The improved interfacial adhesion, thermal stability and mechanical properties (stress–strain, compression and impact resistance of the composites are correlated with the PET functionalization, with non-ionic (PEG and an anionic surfactant (SDS. The results proved that the interface properties are improved by functionalization of PET. The best mechanical properties were recorded at 30 min moulding. The samples with 45% PET–SDS showed the best combination of mechanical properties: tensile strength (1.56 N/mm2, impact strength (43.72 kJ/m2 and compression (158.78 N/mm2.

  1. Dixon Sequence with Superimposed Model-Based Bone Compartment Provides Highly Accurate PET/MR Attenuation Correction of the Brain.

    Science.gov (United States)

    Koesters, Thomas; Friedman, Kent P; Fenchel, Matthias; Zhan, Yiqiang; Hermosillo, Gerardo; Babb, James; Jelescu, Ileana O; Faul, David; Boada, Fernando E; Shepherd, Timothy M

    2016-06-01

    Simultaneous PET/MR of the brain is a promising technology for characterizing patients with suspected cognitive impairment or epilepsy. Unlike CT, however, MR signal intensities do not correlate directly with PET photon attenuation correction (AC), and inaccurate radiotracer SUV estimation can limit future PET/MR clinical applications. We tested a novel AC method that supplements standard Dixon-based tissue segmentation with a superimposed model-based bone compartment. We directly compared SUV estimation between MR-based AC and reference CT AC in 16 patients undergoing same-day PET/CT and PET/MR with a single (18)F-FDG dose for suspected neurodegeneration. Three Dixon-based MR AC methods were compared with CT: standard Dixon 4-compartment segmentation alone, Dixon with a superimposed model-based bone compartment, and Dixon with a superimposed bone compartment and linear AC optimized specifically for brain tissue. The brain was segmented using a 3-dimensional T1-weighted volumetric MR sequence, and SUV estimations were compared with CT AC for whole-image, whole-brain, and 91 FreeSurfer-based regions of interest. Modifying the linear AC value specifically for brain and superimposing a model-based bone compartment reduced the whole-brain SUV estimation bias of Dixon-based PET/MR AC by 95% compared with reference CT AC (P < 0.05), resulting in a residual -0.3% whole-brain SUVmean bias. Further, brain regional analysis demonstrated only 3 frontal lobe regions with an SUV estimation bias of 5% or greater (P < 0.05). These biases appeared to correlate with high individual variability in frontal bone thickness and pneumatization. Bone compartment and linear AC modifications result in a highly accurate MR AC method in subjects with suspected neurodegeneration. This prototype MR AC solution appears equivalent to other recently proposed solutions and does not require additional MR sequences and scanning time. These data also suggest that exclusively model-based MR AC

  2. PET/MR in oncology

    DEFF Research Database (Denmark)

    Balyasnikova, Svetlana; Löfgren, Johan; de Nijs, Robin

    2012-01-01

    After more than 20 years of research, a fully integrated PET/MR scanner was launched in 2010 enabling simultaneous acquisition of PET and MR imaging. Currently, no clinical indication for combined PET/MR has been established, however the expectations are high. In this paper we will discuss some...... of the challenges inherent in this new technology, but focus on potential applications for simultaneous PET/MR in the field of oncology. Methods and tracers for use with the PET technology will be familiar to most readers of this journal; thus this paper aims to provide a short and basic introduction to a number...... be applied together with PET increasing the amount of information about the tissues of interest. The potential clinical benefit of applying PET/MR in staging, radiotherapy planning and treatment evaluation in oncology, as well as the research perspectives for the use of PET/MR in the development of new...

  3. PET/MR in oncology

    DEFF Research Database (Denmark)

    Balyasnikova, Svetlana; Löfgren, Johan; de Nijs, Robin

    2012-01-01

    be applied together with PET increasing the amount of information about the tissues of interest. The potential clinical benefit of applying PET/MR in staging, radiotherapy planning and treatment evaluation in oncology, as well as the research perspectives for the use of PET/MR in the development of new......After more than 20 years of research, a fully integrated PET/MR scanner was launched in 2010 enabling simultaneous acquisition of PET and MR imaging. Currently, no clinical indication for combined PET/MR has been established, however the expectations are high. In this paper we will discuss some...... of the challenges inherent in this new technology, but focus on potential applications for simultaneous PET/MR in the field of oncology. Methods and tracers for use with the PET technology will be familiar to most readers of this journal; thus this paper aims to provide a short and basic introduction to a number...

  4. Usefulness of {sup 18}F FDG PET/CT for the evaluation of bone marrow involvement in patients with high grade non Hodgkin's lymphoma

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yukyung; Hwang, Kyung Hoon; Hong, Jun Shik; Park, Jinny; Lee, Jae Hoon; Ahn, Jeong Yeal; Kim, Ji Hyun; Lee, Hae Jun; Kim, Seog Gyun; Shin, Ji Young [Gachon Univ. Gil Hospital, Incheon (Korea, Republic of)

    2012-12-15

    To assess the usefulness of {sup 18}F fluorodeoxyglucose PET/CT in the detection of bone marrow (BM) involvement of high grade non Hodgkin's lymphoma (NHL). One hundred twenty patients with newly diagnosed nosed diffuse large b cell lymphoma or peripheral t cell lymphoma between January 2007 and dune 2011, who re received bw trephine biopsy and {sup 18}F FDG PET/CT images and bone marrow biopsy (BMB) results. After reviewing the images, we reviewed the medical records and radiological findings of interesting patients. There were 23 {sup 18}F FDG PET/CT scans in which the marrow was considered to be abnormal (either positive or equivocal), and 97 {sup 18}F FDG PET/CT scans were regarded as having negative FDG uptake. Of 120 patients, 100 (83.3%) had a concordant result of BM interpretation between {sup 18}F FDG PET/CT and BMB, and the remaining 20 patients had discordant results. Among 23 patients with either positive or equivocal {sup 18}F FDG PET/CT scans, 1 of 12 patients with 'positive' {sup 18}F FDG PET/CT had a lymphomatous involvement on BMB. In contrast, 10 of 11 patients with 'equivocal' BM hypermetabolism were reported as having positive involvement on BMB. Patients with abnormal {sup 18}F FDG PET/CT had significantly higher mSUV{sup highestt}han those with normal FDG PET/CT. {sup 18}F FDG PET/CT and BMB are complementary techniques in assessing the presence of BM involvement in patients with high grade NHL. the increasing availability of {sup 18}F FDG PET/CT will raise the need for additional biopsy for FDG avid lesions, especially in patients with negative standard BMBs {sup 18}F FDG PET/CT can be useful as a decision as an initial staging procedure. a direct bone biopsy for FDG avid lesion as an initial staging procedure. a direct bone biopsy for FDG positive bone lesions should be included in staging guidelines in future. In {sup 18}F FDG PET/CT negative cases, BMB is still a powerful procedure, but BMB alone is insufficient

  5. Arterial spin labeling-based Z-maps have high specificity and positive predictive value for neurodegenerative dementia compared to FDG-PET

    Energy Technology Data Exchange (ETDEWEB)

    Faellmar, David; Larsson, Elna-Marie [Uppsala University, Department of Surgical Sciences, Radiology, Uppsala (Sweden); Haller, Sven [Uppsala University, Department of Surgical Sciences, Radiology, Uppsala (Sweden); University Medical Center Freiburg, Department of Neuroradiology, Freiburg (Germany); University of Geneva, Faculty of Medicine, Geneva (Switzerland); Affidea CDRC - Centre Diagnostique Radiologique de Carouge, Carouge (Switzerland); Lilja, Johan [Uppsala University, Department of Surgical Sciences, Nuclear Medicine and PET, Uppsala (Sweden); Hermes Medical Solutions, Stockholm (Sweden); Danfors, Torsten [Uppsala University, Department of Surgical Sciences, Nuclear Medicine and PET, Uppsala (Sweden); Kilander, Lena [Uppsala University, Department of Public Health and Caring Sciences, Geriatrics, Uppsala (Sweden); Tolboom, Nelleke; Croon, Philip M.; Berckel, Bart N.M. van [VU University Medical Center, Department of Radiology and Nuclear Medicine, Amsterdam (Netherlands); Egger, Karl [University Medical Center Freiburg, Department of Neuroradiology, Freiburg (Germany); Kellner, Elias [Medical Center University of Freiburg, Department of Radiology, Medical Physics, Faculty of Medicine, Freiburg (Germany); Verfaillie, Sander C.J.; Ossenkoppele, Rik [VU University Medical Center, Department of Neurology, Alzheimer Center Amsterdam, Amsterdam (Netherlands); Barkhof, Frederik [VU University Medical Center, Department of Radiology and Nuclear Medicine, Amsterdam (Netherlands); UCL, Institutes of Neurology and Healthcare Engineering, London (United Kingdom)

    2017-10-15

    Cerebral perfusion analysis based on arterial spin labeling (ASL) MRI has been proposed as an alternative to FDG-PET in patients with neurodegenerative disease. Z-maps show normal distribution values relating an image to a database of controls. They are routinely used for FDG-PET to demonstrate disease-specific patterns of hypometabolism at the individual level. This study aimed to compare the performance of Z-maps based on ASL to FDG-PET. Data were combined from two separate sites, each cohort consisting of patients with Alzheimer's disease (n = 18 + 7), frontotemporal dementia (n = 12 + 8) and controls (n = 9 + 29). Subjects underwent pseudocontinuous ASL and FDG-PET. Z-maps were created for each subject and modality. Four experienced physicians visually assessed the 166 Z-maps in random order, blinded to modality and diagnosis. Discrimination of patients versus controls using ASL-based Z-maps yielded high specificity (84%) and positive predictive value (80%), but significantly lower sensitivity compared to FDG-PET-based Z-maps (53% vs. 96%, p < 0.001). Among true-positive cases, correct diagnoses were made in 76% (ASL) and 84% (FDG-PET) (p = 0.168). ASL-based Z-maps can be used for visual assessment of neurodegenerative dementia with high specificity and positive predictive value, but with inferior sensitivity compared to FDG-PET. (orig.)

  6. Advanced PET and MR imaging in re-irradiation of high grade glioma

    DEFF Research Database (Denmark)

    Møller, Søren

    2014-01-01

    . The goal of this Ph.D. project was to evaluate the side-effects and efficacy of re-irradiation of highgrade glioma and to determine the value of positron emission tomography (PET) using an amino acid tracer for re-irradiation. Moreover, to identify imaging biomarkers capable of predicting the clinical....... The patients in the re-irradiation study underwent cognitive testing as a means of assessing side effects. The studies showed that the side effects of re-irradiation were acceptable but not negligible. Tumor size evaluated by PET was prognostic for survival following radiotherapy and it PET likely contributed...... inevitable and the goal of all treatment is to prolong life while maintaining quality of life. Radiotherapy is a cornerstone of treatment. In many hospitals repeated irradiation is attempted at recurrence but neither side-effects nor efficacy have been systematically evaluated using modern technology...

  7. Detection of the esp gene in high-level gentamicin resistant Enterococcus faecalis strains from pet animals in Japan.

    Science.gov (United States)

    Harada, Tetsuya; Tsuji, Noboru; Otsuki, Koichi; Murase, Toshiyuki

    2005-03-20

    We investigated the prevalence of the esp gene and the susceptibility to gentamicin in Enterococcus faecalis and E. faecium strains obtained from pet animals. Nine of 30 E. faecalis and 2 of 38 E. faecium strains from the pet animals had the esp gene. Three esp-positive E. faecalis strains, which were isolated from two dogs and a cat, showed gentamicin MICs of > or =256 microg/ml and harbored the high-level gentamicin resistance (HLGR) gene, aac(6')-Ie-aph(2'')-Ia. Of the nine esp-positive E. faecalis strains, five, including the three strains with the HLGR gene, were closely related by numerical analysis of PFGE patterns. Longitudinal investigation needs to elucidate whether the HLGR gene was incorporated into a subpopulation of the esp-positive E. faecalis.

  8. Feasibility of a novel design of high resolution parallax-free Compton enhanced PET scanner dedicated to brain research

    CERN Document Server

    Braem, André; Chesi, Enrico Guido; Correia, J G; Garibaldi, F; Joram, C; Mathot, S; Nappi, E; Ribeiro da Silva, M; Schoenahl, F; Séguinot, Jacques; Weilhammer, P; Zaidi, H

    2004-01-01

    A novel concept for a positron emission tomography (PET) camera module is proposed, which provides full 3D reconstruction with high resolution over the total detector volume, free of parallax errors. The key components are a matrix of long scintillator crystals and hybrid photon detectors (HPDs) with matched segmentation and integrated readout electronics. The HPDs read out the two ends of the scintillator package. Both excellent spatial (x, y, z) and energy resolution are obtained. The concept allows enhancing the detection efficiency by reconstructing a significant fraction of events which underwent Compton scattering in the crystals. The proof of concept will first be demonstrated with yttrium orthoaluminate perovskite (YAP):Ce crystals, but the final design will rely on other scintillators more adequate for PET applications (e.g. LSO:Ce or LaBr /sub 3/:Ce). A promising application of the proposed camera module, which is currently under development, is a high resolution 3D brain PET camera with an axial fi...

  9. Pet Health

    Science.gov (United States)

    Pets can add fun, companionship and a feeling of safety to your life. Before getting a pet, think carefully about which animal is best for ... is each family member looking for in a pet? Who will take care of it? Does anyone ...

  10. {sup 18}F-Fluoride PET/CT is highly effective for excluding bone metastases even in patients with equivocal bone scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Bortot, Daniel C.; Amorim, Barbara J.; Oki, Glaucia C.; Santos, Allan O.; Lima, Mariana C.L.; Etchebehere, Elba C.S.C.; Ramos, Celso Dario [State University of Campinas (UNICAMP), Division of Nuclear Medicine, Department of Radiology, Avenue Zeferino Vaz, S/N., PO Box 6149, Campinas (Brazil); Gapski, Sergio B. [Medicina Nuclear Diagnostico e Terapia, Nuclear Medicine Clinic, Campinas (Brazil); Barboza, Marycel F.; Mengatti, Jair [Nuclear and Energy Research Institute (IPEN)-CNEN, Radiopharmacy Directory, Sao Paulo (Brazil)

    2012-11-15

    Bone scintigraphy (BS) has been used extensively for many years for the diagnosis of bone metastases despite its low specificity and significant rate of equivocal lesions. {sup 18}F-Fluoride PET/CT has been proven to have a high sensitivity and specificity in the detection of malignant bone lesions, but its effectiveness in patients with inconclusive lesions on BS is not well documented. This study evaluated the ability of {sup 18}F-fluoride PET/CT to exclude bone metastases in patients with various malignant primary tumours and nonspecific findings on BS. We prospectively studied 42 patients (34-88 years of age, 26 women) with different types of tumour. All patients had BS performed for staging or restaging purposes but with inconclusive findings. All patients underwent {sup 18}F-fluoride PET/CT. All abnormalities identified on BS images were visually compared with their appearance on the PET/CT images. All the 96 inconclusive lesions found on BS images of the 42 patients were identified on PET/CT images. {sup 18}F-Fluoride PET/CT correctly excluded bone metastases in 23 patients (68 lesions). Of 19 patients (28 lesions) classified by PET/CT as having metastases, 3 (5 lesions) were finally classified as free of bone metastases on follow-up. The sensitivity, specificity, and positive and negative predictive values of {sup 18}F-fluoride PET/CT were, respectively, 100 %, 88 %, 84 % and 100 % for the identification of patients with metastases (patient analysis) and 100 %, 82 % and 100 % for the identification of metastatic lesions (lesion analysis). The factors that make BS inconclusive do not affect {sup 18}F-fluoride PET/CT which shows a high sensitivity and negative predictive value for excluding bone metastases even in patients with inconclusive conventional BS. (orig.)

  11. Impact of [18F]-fluoro-ethyl-tyrosine PET imaging on target definition for radiation therapy of high-grade glioma.

    Science.gov (United States)

    Munck Af Rosenschold, Per; Costa, Junia; Engelholm, Svend Aage; Lundemann, Michael J; Law, Ian; Ohlhues, Lars; Engelholm, Silke

    2015-05-01

    We sought to assess the impact of amino-acid (18)F-fluoro-ethyl-tyrosine (FET) positron emission tomography (PET) on the volumetric target definition for radiation therapy of high-grade glioma versus the current standard using MRI alone. Specifically, we investigated the influence of tumor grade, MR-defined tumor volume, and the extent of surgical resection on PET positivity. Fifty-four consecutive high-grade glioma patients (World Health Organization grades III-IV) with confirmed histology were scanned using FET-PET/CT and T1 and T2/fluid attenuated inversion recovery MRI. Gross tumor volume and clinical target volumes (CTVs) were defined in a blinded fashion based on MRI and subsequently PET, and volumetric analysis was performed. The extent of the surgical resection was reviewed using postoperative MRI. Overall, for ∼ 90% of the patients, the PET-positive volumes were encompassed by T1 MRI with contrast-defined tumor plus a 20-mm margin. The tumor volume defined by PET was larger for glioma grade IV (P PET positive volume tended to be larger for grade IV tumors (P = .018). With an unchanged CTV margin and by including FET-PET for gross tumor volume definition, the CTV will increase moderately for most patients, and quite substantially for a minority of patients. Patients with grade IV glioma were found to be the primary candidates for PET-guided radiation therapy planning. © The Author(s) 2014. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  12. Highly flexible binder-free core-shell nanofibrous electrode for lightweight electrochemical energy storage using recycled water bottles

    Science.gov (United States)

    Shi, HaoTian H.; Naguib, Hani E.

    2016-08-01

    The creation of a novel flexible nanocomposite fiber with conductive polymer polyaniline (PAni) coating on a polyethylene terephthalate (PET) substrate allowed for increased electrochemical performance while retaining ideal mechanical properties such as very high flexibility. Binder-free PAni-wrapped PET (PAni@PET) fiber with a core-shell structure was successfully fabricated through a novel technique. The PET nanofiber substrate was fabricated through an optimized electrospinning method, while the PAni shell was chemically polymerized onto the surface of the nanofibers. The PET substrate can be made directly from recycled PETE1 grade plastic water bottles. The resulting nanofiber with an average diameter of 121 nm ± 39 nm, with a specific surface area of 83.72 m2 g-1, led to better ionic interactions at the electrode/electrolyte interface. The PAni active layer coating was found to be 69 nm in average thickness. The specific capacitance was found to have increased dramatically from pure PAni with carbon binders. The specific capacitance was found to be 347 F g-1 at a relatively high scan rate of 10 mV s-1. The PAni/PET fiber also experienced very little degradation (4.4%) in capacitance after 1500 galvanostatic charge/discharge cycles at a specific current of 1.2 A g-1. The mesoporous structure of the PAni@PET fibrous mat also allowed for tunable capacitance by controlling the pore sizes. This novel fabrication method offers insights for the utilization of recycled PETE1 based bottles as a high performance, low cost, highly flexible supercapacitor device.

  13. Integrated PET/MR.

    Science.gov (United States)

    Quick, Harald H

    2014-02-01

    Integrated whole-body PET/MR hybrid imaging combines excellent soft tissue contrast and various functional imaging parameters provided by MR with high sensitivity and quantification of radiotracer metabolism provided by positron emission tomography (PET). While clinical evaluation now is under way, integrated PET/MR demands for new technologies and innovative solutions, currently subject to interdisciplinary research. Attenuation correction of human soft tissues and of hardware components has to be MR-based to maintain quantification of PET imaging because computed tomography (CT) attenuation information is missing. This brings up the question of how to provide bone information with MR imaging. The limited field-of-view in MR imaging leads to truncations in body imaging and MR-based attenuation correction. Another research field is the implementation of motion correction technologies to correct for breathing and cardiac motion in view of the relatively long PET data acquisition times. Initial clinical applications of integrated PET/MR in oncology, neurology, pediatric oncology, and cardiovascular disease are highlighted. The hybrid imaging workflow here has to be tailored to the clinical indication to maximize diagnostic information while minimizing acquisition time. PET/MR introduces new artifacts that need special observation and innovative solutions for correction. Finally, the rising need for appropriate phantoms and standardization efforts in PET/MR hybrid imaging is discussed. Copyright © 2013 Wiley Periodicals, Inc.

  14. Synthesis of carbon nanostructures from high density polyethylene (HDPE) and polyethylene terephthalate (PET) waste by chemical vapour deposition

    Science.gov (United States)

    Hatta, M. N. M.; Hashim, M. S.; Hussin, R.; Aida, S.; Kamdi, Z.; Ainuddin, AR; Yunos, MZ

    2017-10-01

    In this study, carbon nanostructures were synthesized from High Density Polyethylene (HDPE) and Polyethylene terephthalate (PET) waste by single-stage chemical vapour deposition (CVD) method. In CVD, iron was used as catalyst and pyrolitic of carbon source was conducted at temperature 700, 800 and 900°C for 30 minutes. Argon gas was used as carrier gas with flow at 90 sccm. The synthesized carbon nanostructures were characterized by FESEM, EDS and calculation of carbon yield (%). FESEM micrograph shows that the carbon nanostructures were only grown as nanofilament when synthesized from PET waste. The synthesization of carbon nanostructure at 700°C was produced smooth and the smallest diameter nanofilament compared to others. The carbon yield of synthesized carbon nanostructures from PET was lower from HDPE. Furthermore, the carbon yield is recorded to increase with increasing of reaction temperature for all samples. Elemental study by EDS analysis were carried out and the formation of carbon nanostructures was confirmed after CVD process. Utilization of polymer waste to produce carbon nanostructures is beneficial to ensure that the carbon nanotechnology will be sustained in future.

  15. {sup 18}F-choline in experimental soft tissue infection assessed with autoradiography and high-resolution PET

    Energy Technology Data Exchange (ETDEWEB)

    Wyss, Matthias T. [PET Center, Division of Nuclear Medicine, University Hospital Zurich, Raemistrasse 100, 8091, Zurich (Switzerland); Center for Radiopharmaceutical Science of ETH, PSI and USZ, Paul Scherrer Institute, Villigen (Switzerland); Weber, Bruno; Spaeth, Nicolas; Buck, Alfred [PET Center, Division of Nuclear Medicine, University Hospital Zurich, Raemistrasse 100, 8091, Zurich (Switzerland); Honer, Michael; Ametamey, Simon M.; Westera, Gerrit [Center for Radiopharmaceutical Science of ETH, PSI and USZ, Paul Scherrer Institute, Villigen (Switzerland); Bode, Beata [Institute of Pathology, University Hospital, Zurich (Switzerland); Kaim, Achim H. [Klinik Im Schachen, Schaenisweg, Aarau (Switzerland)

    2004-03-01

    For each oncological tracer it is important to know the uptake in non-tumorous lesions. The purpose of this study was to measure the accumulation of fluorine-18 choline (FCH), a promising agent for the evaluation of certain tumour types, in infectious tissue. Unilateral thigh muscle abscesses were induced in five rats by intramuscular injection of 0.1 ml of a bacterial suspension (Staphylococcus aureus, 1.2 x 10{sup 9} CFU/ml). In all animals, FCH accumulation was measured with high-resolution positron emission tomography (PET) on day 6. Autoradiography of the abscess and ipsilateral healthy muscle was performed on day 7 (three animals) and day 11 (two animals) and correlated with histology. In addition, {sup 18}F-fluorodeoxyglucose (FDG) PET was performed on day 5. Increased FCH uptake was noted in specific layers of the abscess wall which contained an infiltrate of mainly granulocytes on day 7 and mainly macrophages on day 11. The autoradiographic standardised uptake values in the most active part of the abscess wall were 2.99 on day 7 (n=3) and 4.05 on day 11 (n=2). In healthy muscle the corresponding values were 0.99 and 0.64. The abscesses were clearly visualised on the FCH and FDG PET images. In conclusion, this study demonstrated avid FCH accumulation in inflammatory tissue, which limits the specificity of FCH for tumour detection. Future studies are now needed to determine the degree of this limitation in human cancer patients. (orig.)

  16. Commissioning and Characterization of a Dedicated High-Resolution Breast PET Camera

    Science.gov (United States)

    2014-02-01

    biochemical activity, rather than lesions’ morphology, which is visualized by other imag- ing modalities such as mammography , MRI, and ultrasound. We will...evaluate and compare lesion size, contrast and standard uptake value (SUV). Pilot Study II will validate the utility of 1 mm3 resolution breast-dedicated PET

  17. Quality control of PET radiopharmaceuticals by high-performance liquid chromatography with tris(2,2'-bipyridyl)ruthenium(II) electrogenerated chemiluminescence detection.

    Science.gov (United States)

    Nakao, Ryuji; Furutsuka, Kenji; Fukumura, Toshimitsu; Yamaguchi, Masatoshi; Suzuki, Kazutoshi

    2010-02-01

    A highly sensitive reversed-phase liquid chromatographic (HPLC) method was investigated to analyze a range of positron emission tomography (PET) radiopharmaceuticals using electrogenerated chemiluminescence (ECL) detection. ECL is based on the reaction of PET molecules with tris(2,2'-bipyridyl)ruthenium(III) [Ru(bpy)(3)(3+)], which is generated through the on-line electro-oxidation of Ru(bpy)(3)(2+). In 21 different radiopharmaceuticals studied, 18 compounds could be detected with detection limits (signal-to-noise ratio = 3) of 0.12-72 ng/mL per 20 microL injection. Sufficient reproducibility and linearity were obtained for the quantitative determination of PET molecules in pharmaceutical fluid. This method could be successfully applied to quality control tests of PET radiopharmaceuticals with ultra-high specific radioactivity. (c) 2009 John Wiley & Sons, Ltd.

  18. Arterial and fat tissue inflammation are highly correlated: a prospective {sup 18}F-FDG PET/CT study

    Energy Technology Data Exchange (ETDEWEB)

    Bucerius, Jan [Mount Sinai School of Medicine, Translational and Molecular Imaging Institute, One Gustave L. Levy Place, P. O. Box 1234, New York, NY (United States); Mount Sinai School of Medicine, Department of Radiology, New York, NY (United States); Maastricht University Medical Center, Department of Nuclear Medicine, Maastricht (Netherlands); Maastricht University Medical Center, Cardiovascular Research Institute Maastricht (CARIM), Maastricht (Netherlands); University Hospital RWTH Aachen, Department of Nuclear Medicine, Aachen (Germany); Mani, Venkatesh; Fayad, Zahi A. [Mount Sinai School of Medicine, Translational and Molecular Imaging Institute, One Gustave L. Levy Place, P. O. Box 1234, New York, NY (United States); Mount Sinai School of Medicine, Department of Radiology, New York, NY (United States); Mount Sinai School of Medicine, Department of Cardiology, Zena and Michael A. Weiner Cardiovascular Institute and Marie-Josee and Henry R. Kravis Cardiovascular Health Center, New York, NY (United States); Wong, Stephanie; Moncrieff, Colin; Izquierdo-Garcia, David [Mount Sinai School of Medicine, Translational and Molecular Imaging Institute, One Gustave L. Levy Place, P. O. Box 1234, New York, NY (United States); Mount Sinai School of Medicine, Department of Radiology, New York, NY (United States); Machac, Josef [Mount Sinai School of Medicine, Division of Nuclear Medicine, Department of Radiology, New York, NY (United States); Fuster, Valentin [Mount Sinai School of Medicine, Department of Cardiology, Zena and Michael A. Weiner Cardiovascular Institute and Marie-Josee and Henry R. Kravis Cardiovascular Health Center, New York, NY (United States); The Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid (Spain); Farkouh, Michael E. [Mount Sinai School of Medicine, Department of Cardiology, Zena and Michael A. Weiner Cardiovascular Institute and Marie-Josee and Henry R. Kravis Cardiovascular Health Center, New York, NY (United States); Mount Sinai School of Medicine, Cardiovascular Imaging Clinical Trials Unit, New York, NY (United States); Rudd, James H.F. [University of Cambridge, Division of Cardiovascular Medicine, Cambridge (United Kingdom)

    2014-05-15

    There is evidence that the link between obesity and cardiovascular disease might relate to inflammation in both fat tissue and the arterial wall. {sup 18}F-FDG uptake on PET is a surrogate marker of vessel wall inflammation. The aim of the study was to measure FDG uptake in both regions using PET and identify links between adipose and arterial inflammation. Included in the study were 173 cardiovascular patients who were prospectively imaged with FDG PET/CT. Arterial FDG uptake was measured in the carotid arteries and ascending aorta. The same was done in fat tissue in the neck, the presternal region (both subcutaneous) and the pericardium. FDG uptake was quantified as average maximal target-to-background ratio ({sub mean}TBR{sub max}). Multivariate regression analyses were performed to identify significant associations between arterial and adipose tissue FDG uptake and clinical variables as given by the standardized correlation coefficient (β). FDG uptake values in all fat tissue regions were highly predictive of vascular FDG uptake in both the carotids (β 0.262, p < 0.0001, in the neck subcutaneous region) and aorta (β 0.22, p = 0.008, in the chest pericardial region; β 0.193, p = 0.019, in the chest subcutaneous region). Obesity was significantly associated with elevated FDG uptake in adipose tissue (β 0.470, p < 0.0001, in the neck subcutaneous region; β 0.619, p = 0.028, in the chest subcutaneous region; β 0.978, p = 0.035, in the chest pericardial region). FDG uptake in diverse fat tissue regions was significantly associated with arterial FDG uptake, a reasonable surrogate of inflammation. Increasing body weight significantly predicted the level of fatty inflammation. FDG PET therefore provides imaging evidence of an inflammatory link between fat tissue and the vasculature in patients with cardiovascular disease. (orig.)

  19. Do carotid MR surface coils affect PET quantification in PET/MR imaging?

    Energy Technology Data Exchange (ETDEWEB)

    Willemink, Martin J; Eldib, Mootaz [Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, NY (United States); Leiner, Tim [Department of Radiology, University Medical Center Utrecht, Utrecht (Netherlands); Fayad, Zahi A; Mani, Venkatesh [Translational and Molecular Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, NY (United States)

    2015-05-18

    To evaluate the effect of surface coils for carotid MR imaging on PET quantification in a clinical simultaneous whole-body PET/MR scanner. A cylindrical phantom was filled with a homogeneous 2L water-FDG mixture at a starting dose of 301.2MBq. Clinical PET/MR and PET/CT systems were used to acquire PET-data without a coil (reference standard) and with two carotid MRI coils (Siemens Special Purpose 8-Channel and Machnet 4-Channel Phased Array). PET-signal attenuation was evaluated with Osirix using 51 (PET/MR) and 37 (PET/CT) circular ROIs. Mean and maximum standardized uptake values (SUVs) were quantified for each ROI. Furthermore, SUVs of PET/MR and PET/CT were compared. For validation, a patient was scanned with an injected dose of 407.7MBq on both a PET/CT and a PET/MR system without a coil and with both coils. PET/MR underestimations were -2.2% (Siemens) and -7.8% (Machnet) for SUVmean, and -1.2% (Siemens) and -3.3% (Machnet) for SUVmax, respectively. For PET/CT, underestimations were -1.3% (Siemens) and -1.4% (Machnet) for SUVmean and -0.5% (both Siemens and Machnet) for SUVmax, respectively using no coil data as reference. Except for PET/CT SUVmax values all differences were significant. SUVs differed significantly between PET/MR and PET/CT with SUVmean values of 0.51-0.55 for PET/MR and 0.68-0.69 for PET/CT, respectively. The patient examination showed that median SUVmean values measured in the carotid arteries decreased from 0.97 without a coil to 0.96 (Siemens) and 0.88 (Machnet). Carotid surface coils do affect attenuation correction in both PET/MR and PET/CT imaging. Furthermore, SUVs differed significantly between PET/MR and PET/CT.

  20. Impact of [F-18]-fluoro-ethyl-tyrosine PET imaging on target definition for radiation therapy of high-grade glioma

    DEFF Research Database (Denmark)

    af Rosenschold, Per Munck; Costa, Junia; Engelholm, Svend Aage

    2015-01-01

    BACKGROUND: We sought to assess the impact of amino-acid (18)F-fluoro-ethyl-tyrosine (FET) positron emission tomography (PET) on the volumetric target definition for radiation therapy of high-grade glioma versus the current standard using MRI alone. Specifically, we investigated the influence....... Patients with grade IV glioma were found to be the primary candidates for PET-guided radiation therapy planning....

  1. Zoonotic disease risks for immunocompromised and other high-risk clients and staff: promoting safe pet ownership and contact.

    Science.gov (United States)

    Stull, Jason W; Stevenson, Kurt B

    2015-03-01

    Pets can be a source of disease (zoonoses) for humans. The disease risks associated with pet contact are highest among young children, the elderly, pregnant women, and immunocompromised hosts. These individuals and household members display limited knowledge of pet-associated disease, rarely recall receipt of pet-associated disease information, and report pet ownership practices that are often at odds with established disease prevention recommendations. Veterinary staff are in a key position to promote safe pet ownership and contact practices. Encouraging and safeguarding client disclosure of immunocompromising health conditions and promoting veterinarian-physician communications are critical for effectively providing this service. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. First Results From a High-Resolution Small Animal SiPM PET Insert for PET/MR Imaging at 7T

    Science.gov (United States)

    Goertzen, Andrew L.; Stortz, Greg; Thiessen, Jonathan D.; Bishop, Daryl; Khan, Muhammad Salman; Kozlowski, Piotr; Retière, Fabrice; Schellenberg, Graham; Shams, Ehsan; Sossi, Vesna; Thompson, Christopher J.

    2016-10-01

    We present the initial results from a small animal PET insert designed to be operated inside a 7T MRI. The insert fits within the 114 mm inner diameter of the Bruker BGA-12S gradient coil while accommodating the Bruker 35 mm volume RF coil (outer diameter 60 mm), both used in the Bruker 70/20 MRI systems. The PET insert is a ring comprising 16 detectors. Each detector has a dual-layer offset (DLO) lutetium-yttrium oxyorthsilicate (LYSO) scintillator array read out by two SensL SPMArray4B SiPM arrays. The DLO scintillator has bottom (top) layers of: 22 × 10 (21 × 9) crystals of size 1.2 × 1.2 × 6 (4) mm3 for a total of 409 crystals per block, providing an axial extent of 28.17 mm. The detector outputs are multiplexed to four signals using a custom readout board and digitized using the OpenPET data acquisition platform. The detector flood images successfully resolve over 99% of the crystals, with average energy resolution of 12.5 ± 2.0% at 511 keV. Testing of the PET system inside the MRI showed that the PET insert had no effect on MRI image homogeneity and only a small effect on echo planar images (EPI) signal to noise ratio (SNR) (-9%), with neither PET nor MRI images showing obvious artefacts. These acquisitions used the OpenPET operating in “oscilloscope mode” with USB2.0 interface, allowing a maximum total singles event rate of 280 kcps, strongly limiting the count rate capabilities of the system. The PET radial spatial resolution (as measured with a 22Na point source and FBP-3DRP reconstruction) is 1.17 mm at the centre, degrading to 1.86 mm at a 15 mm radial offset. Simultaneous phantom and mouse PET/MR imaging produced good quality images that were free of any obvious artefacts.

  3. Arterial spin labeling-based Z-maps have high specificity and positive predictive value for neurodegenerative dementia compared to FDG-PET.

    Science.gov (United States)

    Fällmar, David; Haller, Sven; Lilja, Johan; Danfors, Torsten; Kilander, Lena; Tolboom, Nelleke; Egger, Karl; Kellner, Elias; Croon, Philip M; Verfaillie, Sander C J; van Berckel, Bart N M; Ossenkoppele, Rik; Barkhof, Frederik; Larsson, Elna-Marie

    2017-10-01

    Cerebral perfusion analysis based on arterial spin labeling (ASL) MRI has been proposed as an alternative to FDG-PET in patients with neurodegenerative disease. Z-maps show normal distribution values relating an image to a database of controls. They are routinely used for FDG-PET to demonstrate disease-specific patterns of hypometabolism at the individual level. This study aimed to compare the performance of Z-maps based on ASL to FDG-PET. Data were combined from two separate sites, each cohort consisting of patients with Alzheimer's disease (n = 18 + 7), frontotemporal dementia (n = 12 + 8) and controls (n = 9 + 29). Subjects underwent pseudocontinuous ASL and FDG-PET. Z-maps were created for each subject and modality. Four experienced physicians visually assessed the 166 Z-maps in random order, blinded to modality and diagnosis. Discrimination of patients versus controls using ASL-based Z-maps yielded high specificity (84%) and positive predictive value (80%), but significantly lower sensitivity compared to FDG-PET-based Z-maps (53% vs. 96%, p maps can be used for visual assessment of neurodegenerative dementia with high specificity and positive predictive value, but with inferior sensitivity compared to FDG-PET. • ASL-based Z-maps yielded high specificity and positive predictive value in neurodegenerative dementia. • ASL-based Z-maps had significantly lower sensitivity compared to FDG-PET-based Z-maps. • FDG-PET might be reserved for ASL-negative cases where clinical suspicion persists. • Findings were similar at two study sites.

  4. Integrated PET/MR

    National Research Council Canada - National Science Library

    Quick, Harald H

    2014-01-01

    Integrated whole‐body PET/MR hybrid imaging combines excellent soft tissue contrast and various functional imaging parameters provided by MR with high sensitivity and quantification of radiotracer metabolism provided...

  5. PET/CT surveillance in patients with Hodgkin lymphoma in first remission is associated with low positive predictive value and high costs

    DEFF Research Database (Denmark)

    El-Galaly, Tarec; Mylam, Karen Juul; Brown, Peter De Nully

    2012-01-01

    positive rate, however, is an important limitation and a confirmatory biopsy is mandatory for the diagnosis of a relapse. With no proven survival benefit for patients with a pre-clinically diagnosed relapse, the high costs and low positive predictive value make PET/CT unfit for routine surveillance......Background. The value of performing post-therapy routine surveillance imaging in patients with Hodgkin lymphoma is controversial. This study evaluates the utility of positron emission tomography / computed tomography using 2-[18F]fluoro-2-deoxyglucose (PET/CT) for this purpose and in situations...... with suspected lymphoma relapse. Design and Methods. We conducted a multicenter retrospective study. Patients with newly diagnosed Hodgkin lymphoma achieving at least a partial remission on first-line therapy were eligible if they received PET/CT surveillance during follow-up. Two types of surveillance PET...

  6. Evaluation of sub-critical water as an extraction fluid for model contaminants from recycled PET for reuse as food packaging material.

    Science.gov (United States)

    Santos, Amélia S F; Agnelli, José A M; Manrich, Sati

    2010-04-01

    Recycling of plastics for food-contact packaging is an important issue and research into meaningful and cost-effective solutions is in progress. In this paper, the use of sub-critical water was evaluated as an alternative way of purifying poly(ethylene terephthalate) (PET) flakes for direct food contact applications. The effects of temperature, pressure and flow rate were assessed on the extraction efficiency of two of the most challenging classes of contaminants (toluene and benzophenone) from PET by sub-critical water using a first-order fractional experimental design. Extraction yield was quantified using GC/FID. The most important parameter was flow rate, indicating that the decrease in sub-critical water polarity with temperature was insufficient to eliminate partition effects. Temperature was also important, but only for the optimization of toluene extraction. These results may be explained by the poor solubility of higher molar mass compounds in sub-critical water compared to lower molar mass compounds under the same conditions, and the small decrease in dielectric constant with temperature under the experimental conditions evaluated. As cleaning efficiency is low and PET is very susceptible to hydrolysis, which limits the use of higher temperatures vis-à-vis physical recycling, the proposed extraction is unsuitable for a standalone super-clean process but may be a step in the process.

  7. Feasibility study of a highly sensitive LaBr{sub 3} PET scanner based on the DOI-dependent extended-energy window

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Eiji [Naitonal Institute of Radiological Sciences, Chiba (Japan)], E-mail: rush@nirs.go.jp; Kitamura, Keishi [Shimadzu Corporation, Kyoto (Japan); Nishikido, Fumihiko; Shibuya, Kengo [Naitonal Institute of Radiological Sciences, Chiba (Japan); Hasegawa, Tomoyuki [Kitasato University, Kanagawa (Japan); Yamaya, Taiga; Inadama, Naoko; Murayama, Hideo [Naitonal Institute of Radiological Sciences, Chiba (Japan)

    2009-06-01

    Conventionally, positron emission tomograph (PET) scanners use scintillators which have a high effective atomic number. Recently, novel scintillators like LaBr{sub 3} have been developed which have excellent timing and energy resolutions. LaBr{sub 3} has a high performance for PET scanner use, but its effective atomic number is lower than that of lutetium oxyorthosilicate (LSO). As an alternative, we have developed a scatter reduction method using depth-of-interaction (DOI) information and energy information to increase the sensitivity. The sensitivity of the PET scanner with LaBr{sub 3} can be improved using the DOI-dependent extended-energy window (DEEW) method. In this work, our method is applied to the whole-body LSO/LaBr{sub 3} PET scanner using the GATE simulation toolkit. Simulation results show the number of true coincidences can be increased while minimizing the scatter and random coincidences by using the DEEW method. Noise equivalent count rate (NECR) can be improved by 20-70% for the whole-body DOI-PET scanner. Sensitivity of the PET scanner with a scintillator of low-effective atomic number can be improved by the DEEW method.

  8. High-precision position estimation in PET using artificial neural networks

    Energy Technology Data Exchange (ETDEWEB)

    Mateo, F. [Digital Systems Design Group (DSD), Instituto de las Tecnologias de la Informacion y de las Comunicaciones Avanzadas (ITACA), Universidad Politecnica de Valencia, Camino de Vera s/n, 46022 Valencia (Spain)], E-mail: fermaji@upvnet.upv.es; Aliaga, R.J.; Ferrando, N.; Martinez, J.D.; Herrero, V.; Lerche, Ch.W.; Colom, R.J.; Monzo, J.M.; Sebastia, A.; Gadea, R. [Digital Systems Design Group (DSD), Instituto de las Tecnologias de la Informacion y de las Comunicaciones Avanzadas (ITACA), Universidad Politecnica de Valencia, Camino de Vera s/n, 46022 Valencia (Spain)

    2009-06-01

    Traditionally, the most popular technique to predict the impact position of gamma photons on a PET detector has been Anger's logic. However, it introduces nonlinearities that compress the light distribution, reducing the useful field of view and the spatial resolution, especially at the edges of the scintillator crystal. In this work, we make use of neural networks to address a bias-corrected position estimation from real stimulus obtained from a 2D PET system setup. The preprocessing and data acquisition were performed by separate custom boards, especially designed for this application. The results show that neural networks yield a more uniform field of view while improving the systematic error and the spatial resolution. Therefore, they stand as a better performing and readily available alternative to classic positioning methods.

  9. High-resolution imaging of the large non-human primate brain using microPET: a feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Naidoo-Variawa, S [Discipline of Medical Radiation Sciences, Faculty of Health Sciences, University of Sydney, PO Box 170, Lidcombe, NSW 1825, Sydney (Australia); Hey-Cunningham, A J [Discipline of Medical Radiation Sciences, Faculty of Health Sciences, University of Sydney, PO Box 170, Lidcombe, NSW 1825, Sydney (Australia); Lehnert, W [Discipline of Medical Radiation Sciences, Faculty of Health Sciences, University of Sydney, PO Box 170, Lidcombe, NSW 1825, Sydney (Australia); Kench, P L [Discipline of Medical Radiation Sciences, Faculty of Health Sciences, University of Sydney, PO Box 170, Lidcombe, NSW 1825, Sydney (Australia); Kassiou, M [Discipline of Medical Radiation Sciences, Faculty of Health Sciences, University of Sydney, PO Box 170, Lidcombe, NSW 1825, Sydney (Australia); Banati, R [Discipline of Medical Radiation Sciences, Faculty of Health Sciences, University of Sydney, PO Box 170, Lidcombe, NSW 1825, Sydney (Australia); Meikle, S R [Discipline of Medical Radiation Sciences, Faculty of Health Sciences, University of Sydney, PO Box 170, Lidcombe, NSW 1825, Sydney (Australia)

    2007-11-21

    The neuroanatomy and physiology of the baboon brain closely resembles that of the human brain and is well suited for evaluating promising new radioligands in non-human primates by PET and SPECT prior to their use in humans. These studies are commonly performed on clinical scanners with 5 mm spatial resolution at best, resulting in sub-optimal images for quantitative analysis. This study assessed the feasibility of using a microPET animal scanner to image the brains of large non-human primates, i.e. papio hamadryas (baboon) at high resolution. Factors affecting image accuracy, including scatter, attenuation and spatial resolution, were measured under conditions approximating a baboon brain and using different reconstruction strategies. Scatter fraction measured 32% at the centre of a 10 cm diameter phantom. Scatter correction increased image contrast by up to 21% but reduced the signal-to-noise ratio. Volume resolution was superior and more uniform using maximum a posteriori (MAP) reconstructed images (3.2-3.6 mm{sup 3} FWHM from centre to 4 cm offset) compared to both 3D ordered subsets expectation maximization (OSEM) (5.6-8.3 mm{sup 3}) and 3D reprojection (3DRP) (5.9-9.1 mm{sup 3}). A pilot {sup 18}F-2-fluoro-2-deoxy-d-glucose ([{sup 18}F]FDG) scan was performed on a healthy female adult baboon. The pilot study demonstrated the ability to adequately resolve cortical and sub-cortical grey matter structures in the baboon brain and improved contrast when images were corrected for attenuation and scatter and reconstructed by MAP. We conclude that high resolution imaging of the baboon brain with microPET is feasible with appropriate choices of reconstruction strategy and corrections for degrading physical effects. Further work to develop suitable correction algorithms for high-resolution large primate imaging is warranted.

  10. Differentiation of molecular chain entanglement structure through laser Raman spectrum measurement of High strength PET fibers under stress

    Science.gov (United States)

    Go, D.; Takarada, W.; Kikutani, T.

    2017-10-01

    The aim of this study was to investigate the mechanism for the improvement of mechanical properties of poly(ethylene terephthalate) (PET) fibers based on the concept of controlling the state of molecular entanglement. For this purpose, five different PET fibers were prepared through either the conventional melt spinning and drawing/annealing process or the high-speed melt spinning process. In both cases, the melt spinning process was designed so as to realize different Deborah number conditions. The prepared fibers were subjected to the laser Raman spectroscopy measurement and the characteristics of the scattering peak at around 1616 cm‑1, which corresponds to the C-C/C=C stretching mode of the aromatic ring in the main chain, were investigated in detail. It was revealed that the fibers drawn and annealed after the melt spinning process of lower Deborah number showed higher tensile strength as well as lower value of full width at half maximum (FWHM) in the laser Raman spectrum. Narrow FWHM was considered to represent the homogeneous state of entanglement structure, which may lead to the higher strength and toughness of fibers because individual molecular chains tend to bare similar level of tensile stress when the fiber is stretched. In case of high-speed spun fibers prepared with a high Deborah number condition, the FWHM was narrow presumably because much lower tensile stress in comparison with the drawing/annealing process was applied when the fiber structure was developed, however the value increased significantly upon applying tensile load to the fibers during the laser Raman spectrum measurement. From these results, it was concluded that the Laser Raman spectroscopy could differentiate molecular chain entanglement structure of various fiber samples, in that low FWHM, which corresponds to either homogeneous state of molecular entanglement or lower level of mean residual stress, and small increase of FWTH upon applying tensile stress are considered to be the

  11. Canine distemper outbreak in pet store puppies linked to a high-volume dog breeder.

    Science.gov (United States)

    Schumaker, Brant A; Miller, Myrna M; Grosdidier, Paul; Cavender, Jacqueline L; Montgomery, Donald L; Cornish, Todd E; Farr, Robert M; Driscoll, Michael; Maness, Lori J; Gray, Tangney; Petersen, Dana; Brown, William L; Logan, Jim; O'Toole, Donal

    2012-11-01

    Canine distemper is uncommon in the pet trade in the United States, in large part due to effective vaccines against Canine distemper virus (CDV). This is a report of CDV affecting 24 young dogs of multiple breeds shortly after sale by 2 pet stores in Wyoming during August-October 2010. Cases were diagnosed over 37 days. Diagnosis was established by a combination of fluorescent antibody staining, reverse transcription polymerase chain reaction, negative stain electron microscopy, and necropsy with histopathology. Viral hemagglutinin gene sequences were analyzed from 2 affected dogs and were identical (GenBank accession no. JF283477). Sequences were distinct from those in a contemporaneous unrelated case of CDV in a Wyoming dog (JF283476) that had no contact with the pet store dogs. The breeding property from which the puppies originated was quarantined by the Kansas Animal Health Department. Puppies intended for sale were tested for CDV. Canine distemper was diagnosed on site in November 2010. At that point 1,466 dogs were euthanized to eliminate dispersal of the disease through commercial channels. The investigation underscores the risks inherent in large-scale dog breeding when vaccination and biosecurity practices are suboptimal.

  12. Effects of multiple-interaction photon events in a high-resolution PET system that uses 3-D positioning detectors

    Science.gov (United States)

    Gu, Yi; Pratx, Guillem; Lau, Frances W. Y.; Levin, Craig S.

    2010-01-01

    .7% for coincidence) was noted for a uniform phantom when MIPEs with summed-energy falling within a ±12% window around the photopeak were also included. Both experimental and simulation data demonstrate that deposition falling within that energy window interacted with both crystal arrays within the same dual-LSO-PSAPD module. This result establishes the feasibility of a proposed multiplexed readout of analog output signals of the two PSAPDs within each module. Using MIPEs with summed-energy deposition within the 511 keV±12% photopeak window and a new method for estimating the location of the first photon interaction in MIPEs, the corresponding reconstructed image exhibited a peak CNR of 7.23 for the 8 mm diameter phantom spheres versus a CNR of 6.69 from images based solely on single LSO array interaction events. The improved system photon sensitivity could be exploited to reduce the scan time by up to approximately 10%, while still maintaining image quality comparable to that achieved if MIPEs were excluded. Conclusions: MIPE distribution in the detectors allows the proposed photodetector multiplexing arrangement without significant information loss. Furthermore, acquiring MIPEs can enhance system photon sensitivity and improve PET image CNR and CRC. The system under development can therefore competently acquire and analyze MIPEs and produce high-resolution PET images. PMID:21089785

  13. Effects of multiple-interaction photon events in a high-resolution PET system that uses 3-D positioning detectors.

    Science.gov (United States)

    Gu, Yi; Pratx, Guillem; Lau, Frances W Y; Levin, Craig S

    2010-10-01

    for a uniform phantom when MIPEs with summed-energy falling within a +/- 12% window around the photopeak were also included. Both experimental and simulation data demonstrate that image exhibited a peak CNR of 7.23 for the 8 mm diameter phantom spheres versus a CNR of 6.69 from images based solely on single LSO array interaction events. The improved system photon sensitivity could be exploited to reduce the scan time by up to approximately 10%, while still maintaining image quality comparable to that achieved if MIPEs were excluded. MIPE distribution in the detectors allows the proposed photodetector multiplexing arrangement without significant information loss. Furthermore, acquiring MIPEs can enhance system photon sensitivity and improve PET image CNR and CRC. The system under development can therefore competently acquire and analyze MIPEs and produce high-resolution PET images.

  14. Comparison of clinical non-commercial tools for automated quantification of myocardial blood flow using oxygen-15-labelled water PET/CT.

    Science.gov (United States)

    Harms, Hendrik J; Nesterov, Sergey V; Han, Chunlei; Danad, Ibrahim; Leonora, Remigio; Raijmakers, Pieter G; Lammertsma, Adriaan A; Knuuti, Juhani; Knaapen, Paul

    2014-04-01

    Absolute quantification of myocardial blood flow (MBF) with (15)O-water cardiac positron emission tomography (PET)/CT has recently demonstrated to hold promising diagnostic value for the detection of coronary artery disease (CAD). However, methodological differences in utilized analysis software packages (SP) could affect generated MBF values, potentially prohibiting widespread clinical applicability of obtained normal thresholds. The aim of this study was to compare two validated non-commercial SP, Carimas and Cardiac VUer, for the quantification of MBF using (15)O-water PET. One hundred patients with intermediate likelihood of CAD and scanned in academic centres in Amsterdam (n = 50) and Turku (n = 50) were included in the study. Patients underwent a (15)O-water PET/CT scan during rest and vasodilator stress based on clinical indications. A single observer, blinded from clinical results and with no prior experience in either SP, analysed all patients twice with both SP. Reproducibility of each SP was assessed using intraclass correlation coefficients (ICC). Intersoftware agreement was assessed using paired t-tests and linear regression. ICC was excellent for each SP for both global and regional MBF (ICC >0.90). Global MBF was comparable between Carimas and Cardiac VUer during rest (1.02 ± 0.28 vs. 0.99 ± 0.23 mL min(-1)g(-1), respectively, P = 0.07), and slightly higher for Carimas during stress (2.73 ± 0.82 vs. 2.63 ± 0.84 mL min(-1)g(-1), respectively, P = 0.01). At a regional level, for resting conditions small ( 0.94 for all). For global and regional MBF, Carimas and Cardiac VUer showed excellent agreement and intra-observer reproducibility. These results confirm that, for patients with intermediate likelihood of CAD, these validated SP are interchangeable and can be utilized for routine clinical practice of (15)O-water cardiac PET.

  15. 18F-GP1, a Novel PET Tracer Designed for High-Sensitivity, Low-Background Detection of Thrombi.

    Science.gov (United States)

    Lohrke, Jessica; Siebeneicher, Holger; Berger, Markus; Reinhardt, Michael; Berndt, Mathias; Mueller, Andre; Zerna, Marion; Koglin, Norman; Oden, Felix; Bauser, Marcus; Friebe, Matthias; Dinkelborg, Ludger M; Huetter, Joachim; Stephens, Andrew W

    2017-07-01

    Thromboembolic diseases such as myocardial infarction, stroke, transient ischemic attacks, and pulmonary embolism are major causes of morbidity and mortality worldwide. Glycoprotein IIb/IIIa (GPIIb/IIIa) is the key receptor involved in platelet aggregation and is a validated target for therapeutic approaches and diagnostic imaging. The aim of this study was to develop and characterize a specific small-molecule tracer for PET imaging that binds with high affinity to GPIIb/IIIa receptors and has suitable pharmacokinetic properties to overcome limitations of previous approaches. Methods: Binding of 18F-GP1 to GPIIb/IIIa receptors was investigated in competition binding assays and autoradiography using a fresh cardiac thrombus from an explanted human heart. The clot-to-blood ratio for 18F-GP1 was investigated by an in vitro blood flow model. Biodistribution and thrombus detection was investigated in cynomolgus monkeys after insertion of a roughened catheter into either the vena cava or the aorta. Results:18F-GP1 is an 18F-labeled small molecule for PET imaging of thrombi. The half maximal inhibitory concentration of 18F-GP1 to GPIIb/IIIa was 20 nM. 18F-GP1 bound to thrombi with a mean clot-to-blood ratio of 95. Binding was specific and can be displaced by excess nonradioactive derivative. Binding was not affected by anticoagulants such as aspirin or heparin. 18F-GP1 showed rapid blood clearance and a low background after intravenous injection in cynomolgus monkeys. Small arterial, venous thrombi, thrombotic depositions on damaged endothelial surface, and small cerebral emboli were detected in vivo by PET imaging. Conclusions:18F-GP1 binds specifically with high affinity to the GPIIb/IIIa receptor involved in platelet aggregation. Because of its favorable preclinical characteristics, 18F-GP1 is currently being investigated in a human clinical study. © 2017 by the Society of Nuclear Medicine and Molecular Imaging.

  16. Four-layer depth-of-interaction PET detector for high resolution PET using a multi-pixel S8550 avalanche photodiode

    Energy Technology Data Exchange (ETDEWEB)

    Nishikido, Fumihiko, E-mail: funis@nirs.go.j [Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Inadama, Naoko [Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Oda, Ichiro [Shimadzu Corporation, Nishinokyo Kuwabaracho 1 Nakagyo-ku, Kyoto-shi, Kyoto 604-8511 (Japan); Shibuya, Kengo; Yoshida, Eiji; Yamaya, Taiga [Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Kitamura, Keishi [Shimadzu Corporation, Nishinokyo Kuwabaracho 1 Nakagyo-ku, Kyoto-shi, Kyoto 604-8511 (Japan); Murayama, Hideo [Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan)

    2010-09-21

    Avalanche photodiodes (APDs) are being used as photodetectors in positron emission tomography (PET) because they have many advantages over photomultipliers (PMTs) typically used in PET detectors. We have developed a PET detector that consists of a multi-pixel APD and a 6x6x4 array of 1.46x1.46 mm{sup 2}x4.5 m LYSO crystals for a small animal PET scanner. The detector can identify four-layer depth of interaction (DOI) with a position-sensitive APD coupled to the backside of a crystal array by just an optimized reflector arrangement. Since scintillation lights are shared among many pixels by the method, weaker signals in APD pixels far from the interacting crystals are affected by noise. To evaluate the performance of the four-layer DOI detector with the APD and the influence of electrical noise on our method, we constructed a prototype DOI detector and tested its performance. We found, except for crystal elements on the edge of the crystal array, all crystal elements could be identified from the 2D position histogram. An energy resolution of 16.9% was obtained for the whole crystal array of the APD detector. The results of noise dependence of detector performances indicated that the DOI detector using the APD could achieve sufficient performance even when using application-specific integrated circuits.

  17. The accuracy of {sup 68}Ga-PSMA PET/CT in primary lymph node staging in high-risk prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Oebek, Can; Doganca, Tuenkut [Acibadem Taksim Hospital, Department of Urology, Istanbul (Turkey); Demirci, Emre [Sisli Etfal Training and Research Hospital, Department of Nuclear Medicine, Istanbul (Turkey); Ocak, Meltem [Istanbul University, Faculty of Pharmacy, Department of Pharmaceutical Technology, Istanbul (Turkey); Kural, Ali Riza [Acibadem University, Department of Urology, Istanbul (Turkey); Yildirim, Asif [Istanbul Medeniyet University, Department of Urology, Istanbul (Turkey); Yuecetas, Ugur [Istanbul Training and Research Hospital, Department of Urology, Istanbul (Turkey); Demirdag, Cetin [Istanbul University, Cerrahpasa School of Medicine, Department of Urology, Istanbul (Turkey); Erdogan, Sarper M. [Istanbul University, Cerrahpasa School of Medicine, Department of Public Health, Istanbul (Turkey); Kabasakal, Levent [Istanbul University, Cerrahpasa School of Medicine, Department of Nuclear Medicine, Istanbul (Turkey); Collaboration: Members of Urooncology Association, Turkey

    2017-10-15

    To assess the diagnostic accuracy of {sup 68}Ga-PSMA PET in predicting lymph node (LN) metastases in primary N staging in high-risk and very high-risk nonmetastatic prostate cancer in comparison with morphological imaging. This was a multicentre trial of the Society of Urologic Oncology in Turkey in conjunction with the Nuclear Medicine Department of Cerrahpasa School of Medicine, Istanbul University. Patients were accrued from eight centres. Patients with high-risk and very high-risk disease scheduled to undergo surgical treatment with extended LN dissection between July 2014 and October 2015 were included. Either MRI or CT was used for morphological imaging. PSMA PET/CT was performed and evaluated at a single centre. Sensitivity, specificity and accuracy were calculated for the detection of lymphatic metastases by PSMA PET/CT and morphological imaging. Kappa values were calculated to evaluate the correlation between the numbers of LN metastases detected by PSMA PET/CT and by histopathology. Data on 51 eligible patients are presented. The sensitivity, specificity and accuracy of PSMA PET in detecting LN metastases in the primary setting were 53%, 86% and 76%, and increased to 67%, 88% and 81% in the subgroup with of patients with ≥15 LN removed. Kappa values for the correlation between imaging and pathology were 0.41 for PSMA PET and 0.18 for morphological imaging. PSMA PET/CT is superior to morphological imaging for the detection of metastatic LNs in patients with primary prostate cancer. Surgical dissection remains the gold standard for precise lymphatic staging. (orig.)

  18. Performance of a high-resolution depth-encoding PET detector module using linearly-graded SiPM arrays.

    Science.gov (United States)

    Du, Junwei; Bai, Xiaowei; Gola, Alberto; Acerbi, Fabio; Ferri, Alessandro; Piemonte, Claudio; Yang, Yongfeng; Cherry, Simon R

    2018-01-11

    The goal of this study was to exploit the excellent spatial resolution characteristics of a position-sensitive silicon photomultiplier (SiPM) and develop a high-resolution depth-of-interaction (DOI) encoding positron emission tomography (PET) detector module. The detector consists of a 30 x 30 array of 0.445 mm x 0.445 mm x 20 mm polished LYSO crystals coupled to two 15.5 mm x 15.5 mm linearly-graded SiPM (LG-SiPM) arrays at both ends. The flood histograms show that all the crystals in the LYSO array can be resolved. The energy resolution, the coincidence timing resolution and the DOI resolution were 21.8 ± 5.8 %, 1.23 ± 0.10 ns and 3.8 ± 1.2 mm, respectively, at a temperature of - 10 °C and a bias voltage of 35.0 V. The performance did not degrade significantly for event rates of up to 130,000 counts per second. This detector represents an attractive option for small-bore PET scanner designs that simultaneously emphasize high spatial resolution and high detection efficiency, important, for example, in preclinical imaging of the rodent brain with neuroreceptor ligands. © 2018 Institute of Physics and Engineering in Medicine.

  19. Development of an LC-MS/MS method for studying migration characteristics of acetaldehyde in polyethylene terephthalate (PET)-packed mineral water.

    Science.gov (United States)

    Baumjohann, Nina; Harms, Diedrich

    2015-01-01

    During storage, acetaldehyde migration from polyethylene terephthalate (PET) bottles can affect the quality of mineral water even in the low µg l(-1) range negatively, as it features a fruity or plastic-like off-flavour. For a sensitive and fast analysis of acetaldehyde in mineral water, a new analysis method of 2,4-dinitrophenylhydrazine (DNPH) derivatisation followed by HPLC-electrospray tandem mass spectrometry (ESI-MS/MS) was developed. Acetaldehyde was directly derivatised in the mineral water sample avoiding extraction and/or pre-concentration steps and then analysed by reversed-phase HPLC-ESI-MS/MS using multiple reaction monitoring mode (MRM). Along with method development, the optimum molar excess of DNPH in contrast to acetaldehyde was studied for the mineral water matrix, because no specific and robust data were yet available for this critical parameter. Best results were obtained by using a calibration via the derivatisation reaction. Without any analyte enrichment or extraction, an LOD of 0.5 µg l(-1) and an LOQ of 1.9 µg l(-1) were achieved. Using the developed method, mineral water samples packed in PET bottles from Germany were analysed and the correlation between the acetaldehyde concentration and other characteristics of the samples was evaluated illustrating the applicability of the method. Besides a relationship between bottle size and CO2 content of the mineral water and acetaldehyde migration, a correlation with acetaldehyde migration and the material composition of the bottle, e.g. recycled PET, was noted. Investigating the light influence on the acetaldehyde migration with a newly developed, reproducible light exposure setup, a significant increase of the acetaldehyde concentration in carbonated mineral water samples was observed.

  20. Observation of practices at petting zoos and the potential impact on zoonotic disease transmission.

    Science.gov (United States)

    Weese, J Scott; McCarthy, Lisa; Mossop, Michael; Martin, Hayley; Lefebvre, Sandi

    2007-07-01

    Although petting zoos are common at public events and allow the public to interact with animals, there has been minimal evaluation of practices at petting zoos. Unannounced observation was performed at 36 petting zoos in Ontario, Canada. Observers recorded information, including physical layout, animal species, animal health, types of animal contact permitted, animal sources, hand hygiene facilities, signage, sale of food for human consumption, and hand hygiene compliance. The majority of petting zoos (24 [67%] of 36 petting zoos) were part of temporary events, particularly agricultural fairs (21 [58%] of 36 petting zoos). A variety of animal species were present, including some animals that are considered to be at particularly high risk for disease transmission (neonatal calves and baby chicks). The following items that would come into contact with the mouths of infants and children were carried into the petting zoos: baby bottles (at 17 petting zoos; 50%), pacifiers (at 24 petting zoos; 71%), spill-proofs cups (at 19 petting zoos; 56%), and infant toys (at 22 petting zoos; 65%). Hand hygiene facilities were provided at 34 (94%) of 36 events, and hand hygiene compliance ranged from 0% through 77% (mean compliance [+/-SD], 30.9%+/-22.1%; median compliance, 26.5%). Predictors for increased hand hygiene compliance included the location of a hand hygiene station on an exit route, the presence of hand hygiene reminder signs, and the availability of running water. Numerous deficiencies were encountered. Better education of petting zoo operators and the general public is needed. Provision of hand hygiene stations with running water that are placed near exits is one effective way to encourage compliance.

  1. Pets and Parasites.

    Science.gov (United States)

    Juckett, G

    1997-11-01

    Which parasites can be transmitted by household cats and dogs? Certainly a variety of potentially dangerous helminths and protozoa can be transmitted to humans from pets but, for the most part, very special conditions must be present before this occurs. Small children, pregnant women and immunocompromised persons are three groups at greater potential risk than the general population. Infants and toddlers may contract visceral or cutaneous larva migrans, tapeworm infections and, rarely, other helminths or protozoa. Pregnant women and their offspring are at special risk for toxoplasmosis. Immunocompromised persons (including those with acquired immunodeficiency syndrome) are susceptible to multiple infections but especially to cryptosporidiosis, an underdiagnosed zoonosis present in contaminated water supplies. Other zoonotic infections (Echinococcosis, Dirofilariasis) rarely appear in the general population but, when they do occur, pose very real diagnostic challenges. The risk of disease transmission from pets can be minimized by taking a few simple precautions such as avoiding fecal-oral contact, not emptying the cat's litterbox if pregnant, washing hands carefully after handling pets, worming pets regularly and supervising toddler-pet interactions. In most cases, the psychologic benefits of pet ownership appear to outweigh the reducible risks of disease transmission.

  2. FDG PET/CT evaluation of pathologically proven pulmonary lesions in an area of high endemic granulomatous disease.

    Science.gov (United States)

    Sebro, Ronnie; Aparici, Carina Mari; Hernandez-Pampaloni, Miguel

    2013-05-01

    The goal of this study is to assess how reliable the threshold maximum standardized uptake value (maxSUV) of 2.5 on positron emission tomography-computed tomography (PET/CT) is for evaluation of solitary pulmonary lesions in an area of endemic granulomatous disease and to consider other imaging findings that may increase the accuracy of PET/CT. The staging PET/CT of 72 subjects with solitary pulmonary lesions (nodules (less than 3 cm) or masses (greater than 3 cm)) were retrospectively reviewed. Pathology proven diagnosis from tissue samples was used as the gold standard. Logistic regression was used to assess whether the subject's age, maxSUV, size of lesion, presence of emphysema, or evidence of granulomatous disease was predictive of malignancy. Malignant lesions were identified in 84.7 % (61/72) of the 72 subjects. A threshold maxSUV of 2.5 had a sensitivity of 95.1 % (58/61), specificity of 45.5 % (5/11), positive predictive value of 90.6 % (58/64), negative predictive value of 62.5 % (5/8) and an accuracy of 87.5 % (63/72). The false negative rate was 4.9 %, and the false positive rate was 54.5 %. All 3 false negatives were less than or equal to 1.0 cm; however, false positives ranged from 1.1 to 5.6 cm. The false negatives had a mean (SD) maxSUV of 2.0 (0.4), whereas the false positives had a mean (SD) maxSUV of 5.6 (3.0). Emphysema was associated with 1.1 higher odds of malignancy, and evidence of granulomatous disease was associated with 0.34 lower odds of benign disease, however, neither was statistically significant (p = 0.92 and p = 0.31, respectively). Higher maxSUV was significantly associated with increased risk of malignancy (p = 8.3 × 10(-3)). Older age and larger size of lesion were borderline associated with increased risk of malignancy (p = 0.05 and p = 0.07, respectively). In an area of high endemic granulomatous disease, the PET/CT threshold maxSUV of 2.5 retains a high sensitivity (95.1 %) and positive predictive value (90.6 %) for

  3. Analytical calculation of the lower bound on timing resolution for PET scintillation detectors comprising high-aspect-ratio crystal elements

    Science.gov (United States)

    Cates, Joshua W.; Vinke, Ruud; Levin, Craig S.

    2015-07-01

    Excellent timing resolution is required to enhance the signal-to-noise ratio (SNR) gain available from the incorporation of time-of-flight (ToF) information in image reconstruction for positron emission tomography (PET). As the detector’s timing resolution improves, so does SNR, reconstructed image quality, and accuracy. This directly impacts the challenging detection and quantification tasks in the clinic. The recognition of these benefits has spurred efforts within the molecular imaging community to determine to what extent the timing resolution of scintillation detectors can be improved and develop near-term solutions for advancing ToF-PET. Presented in this work, is a method for calculating the Cramér-Rao lower bound (CRLB) on timing resolution for scintillation detectors with long crystal elements, where the influence of the variation in optical path length of scintillation light on achievable timing resolution is non-negligible. The presented formalism incorporates an accurate, analytical probability density function (PDF) of optical transit time within the crystal to obtain a purely mathematical expression of the CRLB with high-aspect-ratio (HAR) scintillation detectors. This approach enables the statistical limit on timing resolution performance to be analytically expressed for clinically-relevant PET scintillation detectors without requiring Monte Carlo simulation-generated photon transport time distributions. The analytically calculated optical transport PDF was compared with detailed light transport simulations, and excellent agreement was found between the two. The coincidence timing resolution (CTR) between two 3× 3× 20 mm3 LYSO:Ce crystals coupled to analogue SiPMs was experimentally measured to be 162+/- 1 ps FWHM, approaching the analytically calculated lower bound within 6.5%.

  4. Textural analysis of pre-therapeutic [18F]-FET-PET and its correlation with tumor grade and patient survival in high-grade gliomas

    Energy Technology Data Exchange (ETDEWEB)

    Pyka, Thomas; Hiob, Daniela; Wester, Hans-Juergen [Klinikum Rechts der Isar der TU Muenchen, Department of Nuclear Medicine, Munich (Germany); Gempt, Jens; Ringel, Florian; Meyer, Bernhard [Klinikum Rechts der Isar der TU Muenchen, Neurosurgic Department, Munich (Germany); Schlegel, Juergen [Klinikum Rechts der Isar der TU Muenchen, Institute of Pathology and Neuropathology, Munich (Germany); Bette, Stefanie [Klinikum Rechts der Isar der TU Muenchen, Neuroradiologic department, Munich (Germany); Foerster, Stefan [Klinikum Rechts der Isar der TU Muenchen, Department of Nuclear Medicine, Munich (Germany); Klinikum Rechts der Isar der TU Muenchen, TUM Neuroimaging Center (TUM-NIC), Munich (Germany)

    2016-01-15

    Amino acid positron emission tomography (PET) with [18F]-fluoroethyl-L-tyrosine (FET) is well established in the diagnostic work-up of malignant brain tumors. Analysis of FET-PET data using tumor-to-background ratios (TBR) has been shown to be highly valuable for the detection of viable hypermetabolic brain tumor tissue; however, it has not proven equally useful for tumor grading. Recently, textural features in 18-fluorodeoxyglucose-PET have been proposed as a method to quantify the heterogeneity of glucose metabolism in a variety of tumor entities. Herein we evaluate whether textural FET-PET features are of utility for grading and prognostication in patients with high-grade gliomas. One hundred thirteen patients (70 men, 43 women) with histologically proven high-grade gliomas were included in this retrospective study. All patients received static FET-PET scans prior to first-line therapy. TBR (max and mean), volumetric parameters and textural parameters based on gray-level neighborhood difference matrices were derived from static FET-PET images. Receiver operating characteristic (ROC) and discriminant function analyses were used to assess the value for tumor grading. Kaplan-Meier curves and univariate and multivariate Cox regression were employed for analysis of progression-free and overall survival. All FET-PET textural parameters showed the ability to differentiate between World Health Organization (WHO) grade III and IV tumors (p < 0.001; AUC 0.775). Further improvement in discriminatory power was possible through a combination of texture and metabolic tumor volume, classifying 85 % of tumors correctly (AUC 0.830). TBR and volumetric parameters alone were correlated with tumor grade, but showed lower AUC values (0.644 and 0.710, respectively). Furthermore, a correlation of FET-PET texture but not TBR was shown with patient PFS and OS, proving significant in multivariate analysis as well. Volumetric parameters were predictive for OS, but this correlation did not

  5. Hard Water or High Ages?

    DEFF Research Database (Denmark)

    Philippsen, Bente

    2008-01-01

    The aim of this thesis is the investigation of the hardwater effect and its implications for the dating of the first occurrence of pottery in Northern Germany. The hardwater effect denotes the effect of a high carbonate content of freshwater on radiocarbon dating: the dissolved minerals can lead ...

  6. Senior Pets

    Science.gov (United States)

    ... of 7 human years for each year in dog years. Age is not a disease. Although senior pets may develop age-related problems, ... develop diseases such as heart, kidney and liver disease, cancer or ... of pets over 10 years of age. Dogs get cancer at roughly the same rate as ...

  7. A high-resolution and one-cycle conversion time-to-digital converter architecture for PET image applications.

    Science.gov (United States)

    Sheng, Duo; Chung, Ching-Che; Huang, Chih-Chung; Jian, Jia-Wei

    2013-01-01

    In this paper, a high-resolution and one-cycle conversion time-to-digital converter (TDC) architecture with cell-based design for positron emission tomography (PET) applications is presented. The proposed TDC employs a cascade-stage structure to achieve high timing resolution and wide sampling range at the same time. Besides, based on the proposed two-level conversion structure, the proposed TDC not only can achieve single cycle latency and high speed of operation, but also have low circuit complexity as compared with conventional approaches. Simulation results show that operation frequency of the proposed TDC can be improved to 200 MHz with 50 ps resolution. In addition, the proposed TDC can be implemented with standard cells, making it easily portable to different processes and very suitable for biomedical chip applications.

  8. Parasites of importance for human health in Nigerian dogs: high prevalence and limited knowledge of pet owners.

    Science.gov (United States)

    Ugbomoiko, Uade Samuel; Ariza, Liana; Heukelbach, Jorg

    2008-12-09

    Dogs are the most common pet animals worldwide. They may harbour a wide range of parasites with zoonotic potential, thus causing a health risk to humans. In Nigeria, epidemiological knowledge on these parasites is limited. In a community-based study, we examined 396 dogs in urban and rural areas of Ilorin (Kwara State, Central Nigeria) for ectoparasites and intestinal helminths. In addition, a questionnaire regarding knowledge and practices was applied to pet owners. Nine ectoparasite species belonging to four taxa and six intestinal helminth species were identified: fleas (Ctenocephalides canis, Pulex irritans, Tunga penetrans), mites (Demodex canis, Otodectes sp., Sarcoptes scabiei var. canis), ticks (Rhipicephalus sanguineus, Ixodes sp.), and lice (Trichodectes canis); and Toxocara canis, Ancylostoma sp., Trichuris vulpis, Dipylidium caninum, Taenidae and Strongyloides sp. Overall prevalence of ectoparasites was 60.4% and of intestinal helminths 68.4%. The occurrence of C. canis, R. sanguineus, T. canis, Ancylostoma sp. and T. vulpis was most common (prevalence 14.4% to 41.7%). Prevalence patterns in helminths were age-dependent, with T. canis showing a decreasing prevalence with age of host, and a reverse trend in other parasite species. Knowledge regarding zoonoses was very limited and the diseases not considered a major health problem. Treatment with antiparasitic drugs was more frequent in urban areas. Parasites of importance for human health were highly prevalent in Nigerian dogs. Interventions should include health education provided to dog owners and the establishment of a program focusing on zoonotic diseases.

  9. Prognostic value of metabolic tumor volume on {sup 11}C-methionine PET in predicting progression-free survival in high-grade glioma

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Min Young; Paeng, Jin Chul; Cheon, Gi Jeong; Lee, Dong Soo; Chung, June Key; Kang, Keon Wook [Dept. of Nuclear Medicine, Seoul National University Hospital, Seoul (Korea, Republic of); Kim, E. Edmund [Dept. of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Science and Technology, Seoul National University, Seoul (Korea, Republic of)

    2015-12-15

    C-11 methionine (MET) PET is commonly used for diagnosing high-grade glioma (HGG). Recently, volumetric analysis has been widely applied to oncologic PET imaging. In this study, we investigated the prognostic value of metabolic tumor volume (MTV) on MET PET in HGG. A total of 30 patients with anaplastic astrocytoma (n = 12) and glioblastoma multiforme (n = 18) who underwent MET PET before treatment (surgery followed by chemo-radiotherapy) were retrospectively enrolled. Maximal tumor-to-normal brain ratio (TNR{sub max}, maximum tumor activity divided by mean of normal tissue) and MTV (volume of tumor tissue that shows uptake >1.3-fold of mean uptake in normal tissue) were measured on MET PET. Adult patients were classified into two subgroups according to Radiation Therapy Oncology Group Recursive Partitioning Analysis (RTOG RPA) classification. Prognostic values of TNR{sub max}, MTV and clinicopathologic factors were evaluated with regard to progression-free survival (PFS). Median PFS of all patients was 7.9 months (range 1.0–53.8 months). In univariate analysis, MTV (cutoff 35 cm{sup 3}) was a significant prognostic factor for PFS (P = 0.01), whereas TNR{sub max} (cutoff 3.3) and RTOG RPA class were not (P = 0.80 and 0.61, respectively). Treatment of surgical resection exhibited a borderline significance (P = 0.06). In multivariate analysis, MTV was the only independent prognostic factor for PFS (P = 0.03). MTV on MET PET is a significant and independent prognostic factor for PFS in HGG patients, whereas TNR{sub max} is not. Thus, performing volumetric analysis of MET PET is recommended in HGG for better prognostication.

  10. {sup 18}F-DOPA PET/CT for assessment of response to induction chemotherapy in a child with high-risk neuroblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Piccardo, Arnoldo [Galliera Hospital, Nuclear Medicine Unit, Genoa (Italy); E.O. Ospedali Galliera, Department of Nuclear Medicine, Genoa (Italy); Lopci, Egesta [Humanitas Clinical and Research Center, Nuclear Medicine Department, Rozzano, MI (Italy); Foppiani, Luca [Galliera Hospital, Internal Medicine and Endocrinology, Genoa (Italy); Morana, Giovanni [G. Gaslini Children' s Hospital, Department of Pathology and Radiology, Genoa (Italy); Conte, Massimo [G. Gaslini Children' s Hospital, Department of Hematology-Oncology, Genoa (Italy)

    2014-03-15

    Functional imaging plays a crucial role in the assessment of neuroblastoma. The evaluation of response to induction chemotherapy is a cornerstone in scheduling proper treatment management in patients affected by high-risk neuroblastoma. {sup 123}I-metaiodobenzylguanidine has been recognized as the radiopharmaceutical of choice in neuroblastoma assessment. To date, the clinical role of PET/CT in pediatric malignancy is not well established.{sup 18}F-DOPA-PET/CT has been recently used in neuroblastoma, and compared with {sup 123}I-MIBG-scan. Scant new data are available about the role of this tool in the evaluation of treatment response after induction chemotherapy. We investigate the role of {sup 18}F-DOPA-PET/CT in characterizing the response to induction chemotherapy in a child affected by high-risk-neuroblastoma, in whom the rare association of {sup 123}I-MIBG-negative primary tumor and MIBG-positive bone marrow metastases was observed. (orig.)

  11. High-resolution imaging of pulmonary ventilation and perfusion with {sup 68}Ga-VQ respiratory gated (4-D) PET/CT

    Energy Technology Data Exchange (ETDEWEB)

    Callahan, Jason [Centre for Molecular Imaging, Peter MacCallum Cancer Centre, East Melbourne, VIC (Australia); Hofman, Michael S. [The University of Melbourne, Department of Medicine, Peter MacCallum Cancer Centre, Centre for Molecular Imaging, East Melbourne, VIC (Australia); Siva, Shankar [The University of Melbourne, Peter MacCallum Cancer Centre, Department of Radiation Oncology, East Melbourne, VIC (Australia); The University of Melbourne, Sir Peter MacCallum Department of Oncology, East Melbourne, VIC (Australia); Kron, Tomas [The University of Melbourne, Sir Peter MacCallum Department of Oncology, East Melbourne, VIC (Australia); The University of Melbourne, Peter MacCallum Cancer Centre, Department of Physical Sciences, East Melbourne, VIC (Australia); Schneider, Michal E. [Monash University, Department of Medical Imaging and Radiation Science, Clayton, VIC (Australia); Binns, David; Eu, Peter [Peter MacCallum Cancer Centre, Centre for Cancer Imaging, East Melbourne, VIC (Australia); Hicks, Rodney J. [The University of Melbourne, Sir Peter MacCallum Department of Oncology, Peter MacCallum Cancer Centre, Centre for Molecular Imaging, East Melbourne, VIC (Australia)

    2014-02-15

    Our group has previously reported on the use of {sup 68}Ga-ventilation/perfusion (VQ) PET/CT scanning for the diagnosis of pulmonary embolism. We describe here the acquisition methodology for {sup 68}Ga-VQ respiratory gated (4-D) PET/CT and the effects of respiratory motion on image coregistration in VQ scanning. A prospective study was performed in 15 patients with non-small-cell lung cancer. 4-D PET and 4-D CT images were acquired using an infrared marker on the patient's abdomen as a surrogate for breathing motion following inhalation of Galligas and intravenous administration of {sup 68}Ga-macroaggregated albumin. Images were reconstructed with phase-matched attenuation correction. The lungs were contoured on CT and PET VQ images during free-breathing (FB) and at maximum inspiration (Insp) and expiration (Exp). The similarity between PET and CT volumes was measured using the Dice coefficient (DC) comparing the following groups; (1) FB-PET/CT, (2) InspPET/InspCT, (3) ExpPET/Exp CT, and (4) FB-PET/AveCT. A repeated measures one-way ANOVA with multiple comparison Tukey tests were performed to evaluate any difference between the groups. Diaphragmatic motion in the superior-inferior direction on the 4-D CT scan was also measured. 4-D VQ scanning was successful in all patients without additional acquisition time compared to the nongated technique. The highest volume overlap was between ExpPET and ExpCT and between FB-PET and AveCT with a DC of 0.82 and 0.80 for ventilation and perfusion, respectively. This was significantly better than the DC comparing the other groups (0.78-0.79, p < 0.05). These values agreed with a visual inspection of the images with improved image coregistration around the lung bases. The diaphragmatic motion during the 4-D CT scan was highly variable with a range of 0.4-3.4 cm (SD 0.81 cm) in the right lung and 0-2.8 cm (SD 0.83 cm) in the left lung. Right-sided diaphragmatic nerve palsy was observed in 3 of 15 patients. {sup 68}Ga-VQ 4-D

  12. Alignment of 3-dimensional cardiac structures in O-15-labeled water PET emission images with mutual information.

    Science.gov (United States)

    Juslin, Anu; Lötjönen, Jyrki; Nesterov, Sergey V; Kalliokoski, Kari; Knuuti, Juhani; Ruotsalainen, Ulla

    2007-01-01

    The aim of this study was to develop a method to correct the heart position between two oxygen 15-labeled water cardiac positron emission tomography (PET) image sets to be able to use the equivalent regions of interest for the quantification of the perfusion values in the same myocardial segments. Independent component analysis was applied to the dynamic image sets (simulated phantom and 6 rest-pharmacologic stress and 10 rest-rest image sets of healthy female volunteers) acquired at different time points to separate the cardiac structures (ventricles and myocardium). The separated component images from independent component analysis from the 2 studies of the same individual were aligned with a normalized mutual information-based registration method. The alignment parameters were applied to position the regions of interest in the floating image sets for calculation of the myocardial blood flow values. In the rest case the mean myocardial blood flow value was 0.76 +/- 0.12 mL x g(-1) x min(-1) for the manual method and 0.79 +/- 0.10 mL x g(-1) x min(-1) for the proposed method (by use of the right ventricle component in the alignment), and in the stress case these values were 3.39 +/- 0.70 mL x g(-1) x min(-1) and 4.01 +/- 0.71 mL x g(-1) x min(-1), respectively. No statistically significant difference was found between the methods. In the tests with the phantom and patient images the alignment of cardiac structures was shown to be successful. The alignment could be done without the use of information from the myocardial compartment.

  13. Semi-Quantitative Calculations of Primary Tumor Metabolic Activity Using F-18 FDG PET/CT as a Predictor of Survival in 92 Patients With High-Grade Bone or Soft Tissue Sarcoma

    DEFF Research Database (Denmark)

    Andersen, Kim Francis; Fuglo, Hanna Maria; Rasmussen, Sine Hvid

    2015-01-01

    To assess the prognostic value of primary tumor metabolic activity in patients with high-grade bone sarcomas (BS) or soft tissue sarcomas (STS) using F-18 FDG PET/CT. A single-site, retrospective study including 92 patients with high-grade BS or STS. Pretreatment F-18 FDG PET/CT scan was performe...... metabolic activity with pretherapeutic SUVmax using F-18 FDG PET/CT demonstrates independent properties beyond histologic grading for prediction of survival in patients with high-grade STS, but not with high-grade BS.......To assess the prognostic value of primary tumor metabolic activity in patients with high-grade bone sarcomas (BS) or soft tissue sarcomas (STS) using F-18 FDG PET/CT. A single-site, retrospective study including 92 patients with high-grade BS or STS. Pretreatment F-18 FDG PET/CT scan was performed...

  14. Hybrid CT angiography and quantitative (15)O-water PET for assessment of coronary artery disease

    DEFF Research Database (Denmark)

    Thomassen, Anders; Petersen, Henrik; Diederichsen, Axel C P

    2013-01-01

    CT angiography (CTA) can rule out significant stenoses with a very high reliability, whereas its ability to confirm significant stenoses is suboptimal. In contrast, measurements of myocardial blood flow (MBF) provide information on the haemodynamic consequences of stenoses. Therefore, a combinati...

  15. Diabetic Pets

    Science.gov (United States)

    ... health or management, contact your veterinarian. In addition, diabetic pets should be monitored for long-term complications such as cataracts, which commonly develop in diabetic dogs and cats. Other problems that can occur ...

  16. Plasmid-mediated high-level gentamicin resistance among enteric bacteria isolated from pet turtles in Louisiana.

    Science.gov (United States)

    Díaz, María Alejandra; Cooper, Richard Kent; Cloeckaert, Axel; Siebeling, Ronald John

    2006-01-01

    The sale of small turtles is banned by the Food and Drug Administration from the U.S. market due to concerns about their excretion of Salmonella spp. To produce a safe pet for the export market, the Louisiana pet turtle industry uses gentamicin sulfate baths (1,000 microg/ml) to eradicate Salmonella spp. from turtle eggs. In 1999, we analyzed bacterial samples recovered from turtle farms and found that strains of Salmonella enterica subsp. arizonae and other bacteria, such as Enterobacter cloacae, Citrobacter freundii, Pseudomonas aeruginosa, and Stenotrophomonas maltophilia, were resistant to high concentrations of gentamicin (>2,000 microg/ml) and to other aminoglycosides. The goal of this study was to identify the gene(s) which contributes to the high-level gentamicin resistance phenotype observed in bacteria from environmental samples with turtle farming activity, particularly the salmonellae, and to estimate the incidence of such genes in these bacteria. R plasmids from gentamicin-resistant strains were transferred by conjugation and transformation to naive Escherichia coli cells. Cloning and sequencing of the gentamicin resistance determinants on these plasmids revealed the presence of the aminoglycoside acetyltransferase genes aac(3)-IIa and aac(3)-VIa; the latter was present as a gene cassette of a class 1 integron. Multiplex PCR assays showed that every gentamicin-resistant isolate carried one of these acetyltransferase genes. Pulsed-field gel electrophoresis and restriction enzyme digestion analysis of R plasmids carrying these genes revealed different restriction profiles and sizes, indicating a dissemination of the gentamicin resistance genes through mobile molecular elements. The data presented highlight the need to develop an alternate method for the eradication of Salmonella spp. from turtle eggs.

  17. The role of 18F-FDG-PET/CT in the management of patients with high-risk breast cancer: case series and guideline comparison

    NARCIS (Netherlands)

    Bulten, Ben; de Haas, M.J.; Bloemendal, H.J.; van Overbeeke, A.J.; Esser, J.P.; Baarslag, H.J.; de Geus-Oei, Lioe-Fee; de Klerk, J.M.H.

    2014-01-01

    Objectives: In grade III-IV breast cancer, dissemination of disease needs to be assessed. Until now this was done by conventional imaging (liver ultrasonography, chest X-ray and bone scintigraphy), but evidence favoring the use of FDG-PET/CT is accumulating. Methods: Patients with high-risk breast

  18. Prospects for Recycling of Waste PET Bottles in Mauritius

    African Journals Online (AJOL)

    Nafiisah

    ... oils, vinegar, juice and other food stuffs. PET is a linear thermoplastic produced from purified ethylene glycol and mono- terephthalic acid by the polycondensation process. It was first used to make fibres due to its high strength, low water absorption and crease resistance. Today, it is a globally treated commodity polymer.

  19. Clinical application of in vivo treatment delivery verification based on PET/CT imaging of positron activity induced at high energy photon therapy

    Science.gov (United States)

    Janek Strååt, Sara; Andreassen, Björn; Jonsson, Cathrine; Noz, Marilyn E.; Maguire, Gerald Q., Jr.; Näfstadius, Peder; Näslund, Ingemar; Schoenahl, Frederic; Brahme, Anders

    2013-08-01

    The purpose of this study was to investigate in vivo verification of radiation treatment with high energy photon beams using PET/CT to image the induced positron activity. The measurements of the positron activation induced in a preoperative rectal cancer patient and a prostate cancer patient following 50 MV photon treatments are presented. A total dose of 5 and 8 Gy, respectively, were delivered to the tumors. Imaging was performed with a 64-slice PET/CT scanner for 30 min, starting 7 min after the end of the treatment. The CT volume from the PET/CT and the treatment planning CT were coregistered by matching anatomical reference points in the patient. The treatment delivery was imaged in vivo based on the distribution of the induced positron emitters produced by photonuclear reactions in tissue mapped on to the associated dose distribution of the treatment plan. The results showed that spatial distribution of induced activity in both patients agreed well with the delivered beam portals of the treatment plans in the entrance subcutaneous fat regions but less so in blood and oxygen rich soft tissues. For the preoperative rectal cancer patient however, a 2 ± (0.5) cm misalignment was observed in the cranial-caudal direction of the patient between the induced activity distribution and treatment plan, indicating a beam patient setup error. No misalignment of this kind was seen in the prostate cancer patient. However, due to a fast patient setup error in the PET/CT scanner a slight mis-position of the patient in the PET/CT was observed in all three planes, resulting in a deformed activity distribution compared to the treatment plan. The present study indicates that the induced positron emitters by high energy photon beams can be measured quite accurately using PET imaging of subcutaneous fat to allow portal verification of the delivered treatment beams. Measurement of the induced activity in the patient 7 min after receiving 5 Gy involved count rates which were about

  20. Positron Emission Tomography (PET)

    Energy Technology Data Exchange (ETDEWEB)

    Welch, M.J.

    1990-01-01

    Positron emission tomography (PET) assesses biochemical processes in the living subject, producing images of function rather than form. Using PET, physicians are able to obtain not the anatomical information provided by other medical imaging techniques, but pictures of physiological activity. In metaphoric terms, traditional imaging methods supply a map of the body's roadways, its, anatomy; PET shows the traffic along those paths, its biochemistry. This document discusses the principles of PET, the radiopharmaceuticals in PET, PET research, clinical applications of PET, the cost of PET, training of individuals for PET, the role of the United States Department of Energy in PET, and the futures of PET. 22 figs.

  1. Evaluation of the cases of benign disease with high accumulation on the examination of [sup 18]F-fluorodeoxyglucose PET

    Energy Technology Data Exchange (ETDEWEB)

    Okazumi, Shinichi; Enomoto, Kazuo; Fukunaga, Toru (Chiba Univ. (Japan). School of Medicine) (and others)

    1993-12-01

    In this study 39 cases of abdominal benign disease were examined by PET using [sup 18]F-fluorodeoxyglucose (FDG), and 11 cases of them (i.e. 4 cases of liver abscess, 1 of pelvic abscess, 1 of omental abscess, 2 of chronic pancreatitis, 1 of inflammatory pseudotumor of liver, 1 of retroperitoneal leiomyoma and 1 of solid and cystic tumor of pancreas) which showed as high accumulation of FDG as malignant lesion were investigated of their clinical and pathological feature. We used Ci/Cp ratio as index to express the accumulation of FDG in the lesion, which was calculated from radioactivities of the lesion (Ci) and the plasma (Cp) at 60 mins after injection of FDG. The Ci/Cp ratio of the 11 cases was 3.64[+-]0.77. The pathological feature of the 9 inflammatory cases was high accumulation of inflammatory cells and that of the 2 benign tumor cases was solid proliferation of tumor cells. The serum of the 9 inflammatory cases showed high CRP value. It was considered that the high accumulation of FDG in inflammatory lesions was due to piles of FDG uptake of the many inflammatory cells, while the 2 benign tumors of high accumulation were considered that the tumor cell had as high glucose metabolism as malignancies. (author).

  2. Development of a High Precision Axial 3-D PET for Brain Imaging

    CERN Document Server

    Bolle, E; Casella, C; Chesi, E; Clinthorne, N; Cochran, E; De Leo, R; Dissertori, G; Djambazov, L; Honscheid, K; Huh, S; Johnson, I; Joram, C; Kagan, H; Lacasta, C; Lustermann, W; Meddi, F; Nappi, E; Nessi-Tedaldi, F; Oliver, J F; Pauss, F; Rafecas, M; Renker, D; Rudge, A; Schinzel, D; Schneider, T; Séguinot, J; Smith, S; Solevi, P; Stapnes, S; Vilardi, I; Weilhammer, P

    2009-01-01

    We describe a PET device based on a novel method to extract the coordinates of the interaction point of the 511 keV γ rays from 100 mm long and thin LYSO (Lutetium Yttrium OxyorthoSilicate) scintillator bars, positioned axially in the tomograph. The coordinate along the hit crystal is measured by using a hodoscope of Wave Length Shifting (WLS) plastic strips mounted perpendicularly to each plane of scintillators. As photodetectors, new Geiger mode Avalanche PhotoDetectors (G-APDs) with integrated electronics are being used to detect both the hit crystal in a block (x and y coordinates) and the interaction point in the crystal (z coordinate) through the light escaping from the crystal and transmitted to the WLS strips. In this way, the γ interaction point can be determined with a spatial resolution of few cubic millimeters down to a minimum deposited energy of about 50 keV, resulting in a volumetric precision very close to the limits imposed by the physics of the positron annihilation. The method allows to i...

  3. TOFPET 2: A high-performance circuit for PET time-of-flight

    Energy Technology Data Exchange (ETDEWEB)

    Di Francesco, Agostino, E-mail: agodifra@lip.pt [LIP, Lisbon (Portugal); Bugalho, Ricardo [LIP, Lisbon (Portugal); PETsys Electronics, Oeiras (Portugal); Oliveira, Luis [CTS-UNINOVA, DEE FCT-UNL, Caparica (Portugal); Rivetti, Angelo [INFN - sez. Torino (Italy); Rolo, Manuel [LIP, Lisbon (Portugal); INFN - sez. Torino (Italy); Silva, Jose C.; Varela, Joao [LIP, Lisbon (Portugal); PETsys Electronics, Oeiras (Portugal)

    2016-07-11

    We present a readout and digitization ASIC featuring low-noise and low-power for time-of flight (TOF) applications using SiPMs. The circuit is designed in standard CMOS 110 nm technology, has 64 independent channels and is optimized for time-of-flight measurement in Positron Emission Tomography (TOF-PET). The input amplifier is a low impedance current conveyor based on a regulated common-gate topology. Each channel has quad-buffered analogue interpolation TDCs (time binning 20 ps) and charge integration ADCs with linear response at full scale (1500 pC). The signal amplitude can also be derived from the measurement of time-over-threshold (ToT). Simulation results show that for a single photo-electron signal with charge 200 (550) fC generated by a SiPM with (320 pF) capacitance the circuit has 24 (30) dB SNR, 75 (39) ps r.m.s. resolution, and 4 (8) mW power consumption. The event rate is 600 kHz per channel, with up to 2 MHz dark counts rejection.

  4. Target volume definition in high-risk prostate cancer patients using sentinel node SPECT/CT and 18 F-choline PET/CT

    Directory of Open Access Journals (Sweden)

    Vees Hansjörg

    2012-08-01

    Full Text Available Abstract Background To assess the influence of sentinel lymph nodes (SNs SPECT/CT and 18 F-choline (18 F-FCH PET/CT in radiotherapy (RT treatment planning for prostate cancer patients with a high-risk for lymph node (LN involvement. Methods Twenty high-risk prostate cancer patients underwent a pelvic SPECT acquisition following a transrectal ultrasound guided injection of 99mTc-Nanocoll into the prostate. In all patients but one an 18 F-FCH PET/CT for RT treatment planning was performed. SPECT studies were coregistered with the respective abdominal CTs. Pelvic SNs localized on SPECT/CT and LN metastases detected by 18 F-FCH PET/CT were compared to standard pelvic clinical target volumes (CTV. Results A total of 104 pelvic SNs were identified on SPECT/CT (mean 5.2 SNs/patient; range 1–10. Twenty-seven SNs were located outside the standard pelvic CTV, 17 in the proximal common iliac and retroperitoneal regions above S1, 9 in the pararectal fat and 1 in the inguinal region. SPECT/CT succeeded to optimize the definition of the CTV and treatment plans in 6/20 patients due to the presence of pararectal SNs located outside the standard treatment volume. 18 F-FCH PET/CT identified abnormal tracer uptake in the iliac LN region in 2/19 patients. These abnormal LNs were negative on SPECT/CT suggesting a potential blockade of lymphatic drainage by metastatic LNs with a high tumour burden. Conclusions Multimodality imaging which combines SPECT/CT prostate lymphoscintigraphy and 18 F-FCH PET/CT identified SNs outside standard pelvic CTVs or highly suspicious pelvic LNs in 40% of high-risk prostate cancer patients, highlighting the potential impact of this approach in RT treatment planning.

  5. Parasites of importance for human health in Nigerian dogs: high prevalence and limited knowledge of pet owners

    Directory of Open Access Journals (Sweden)

    Heukelbach Jorg

    2008-12-01

    Full Text Available Abstract Background Dogs are the most common pet animals worldwide. They may harbour a wide range of parasites with zoonotic potential, thus causing a health risk to humans. In Nigeria, epidemiological knowledge on these parasites is limited. Methods In a community-based study, we examined 396 dogs in urban and rural areas of Ilorin (Kwara State, Central Nigeria for ectoparasites and intestinal helminths. In addition, a questionnaire regarding knowledge and practices was applied to pet owners. Results Nine ectoparasite species belonging to four taxa and six intestinal helminth species were identified: fleas (Ctenocephalides canis, Pulex irritans, Tunga penetrans, mites (Demodex canis, Otodectes sp., Sarcoptes scabiei var. canis, ticks (Rhipicephalus sanguineus, Ixodes sp., and lice (Trichodectes canis; and Toxocara canis, Ancylostoma sp., Trichuris vulpis, Dipylidium caninum, Taenidae and Strongyloides sp. Overall prevalence of ectoparasites was 60.4% and of intestinal helminths 68.4%. The occurrence of C. canis, R. sanguineus, T. canis, Ancylostoma sp. and T. vulpis was most common (prevalence 14.4% to 41.7%. Prevalence patterns in helminths were age-dependent, with T. canis showing a decreasing prevalence with age of host, and a reverse trend in other parasite species. Knowledge regarding zoonoses was very limited and the diseases not considered a major health problem. Treatment with antiparasitic drugs was more frequent in urban areas. Conclusion Parasites of importance for human health were highly prevalent in Nigerian dogs. Interventions should include health education provided to dog owners and the establishment of a program focusing on zoonotic diseases.

  6. High pressure water jet mining machine

    Science.gov (United States)

    Barker, Clark R.

    1981-05-05

    A high pressure water jet mining machine for the longwall mining of coal is described. The machine is generally in the shape of a plowshare and is advanced in the direction in which the coal is cut. The machine has mounted thereon a plurality of nozzle modules each containing a high pressure water jet nozzle disposed to oscillate in a particular plane. The nozzle modules are oriented to cut in vertical and horizontal planes on the leading edge of the machine and the coal so cut is cleaved off by the wedge-shaped body.

  7. Impact of a second FDG PET scan before adjuvant therapy for the early detection of residual/relapsing tumours in high-risk patients with oral cavity cancer and pathological extracapsular spread

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Chun-Ta; Huang, Shiang-Fu; Chen, I-How; Kang, Chung-Jan [Chang Gung Memorial Hospital and Chang Gung University, Department of Otorhinolaryngology, Head and Neck Surgery, Taoyuan (China); Chang Gung Memorial Hospital and Chang Gung University, Head and Neck Oncology Group, Taoyuan (China); Fan, Kang-Hsing; Lin, Chien-Yu [Chang Gung Memorial Hospital and Chang Gung University, Head and Neck Oncology Group, Taoyuan (China); Chang Gung Memorial Hospital and Chang Gung University, Department of Radiation Oncology, Taoyuan (China); Wang, Hung-Ming [Chang Gung Memorial Hospital and Chang Gung University, Head and Neck Oncology Group, Taoyuan (China); Chang Gung Memorial Hospital and Chang Gung University, Department of Medical Oncology, Taoyuan (China); Ng, Shu-Hang [Chang Gung Memorial Hospital and Chang Gung University, Head and Neck Oncology Group, Taoyuan (China); Chang Gung Memorial Hospital and Chang Gung University, Department of Diagnostic Radiology, Taoyuan (China); Hsueh, Chuen; Lee, Li-Yu [Chang Gung Memorial Hospital and Chang Gung University, Head and Neck Oncology Group, Taoyuan (China); Chang Gung Memorial Hospital and Chang Gung University, Department of Pathology, Taoyuan (China); Lin, Chih-Hung [Chang Gung Memorial Hospital and Chang Gung University, Head and Neck Oncology Group, Taoyuan (China); Chang Gung Memorial Hospital and Chang Gung University, Department of Plastic and Reconstructive Surgery, Taoyuan (China); Yen, Tzu-Chen [Chang Gung Memorial Hospital and Chang Gung University, Head and Neck Oncology Group, Taoyuan (China); Chang Gung Memorial Hospital and Chang Gung University, Department of Nuclear Medicine and Molecular Imaging Center, Taoyuan (China)

    2012-06-15

    Extracapsular spread (ECS) to the cervical lymph nodes is a major adverse prognostic factor in oral cavity squamous cell carcinoma (OSCC). We prospectively examined the value of FDG PET immediately before postoperative radiotherapy/concurrent chemoradiotherapy (pre-RT/CCRT PET) to detect residual/relapsing disease in the early postsurgical follow-up period in high-risk OSCC patients with ECS. We examined 183 high-risk OSCC patients with ECS who underwent preoperative FDG PET/CT for staging purposes. Of these patients, 29 underwent a second pre-RT/CCRT FDG PET/CT scan. The clinical utility of the second FDG PET/CT was examined using Kaplan-Meier curve analysis. Patients who underwent the second FDG PET/CT scan had baseline clinicopathological characteristics similar to those who did not undergo a second scan. Of the patients who underwent the second scan, seven (24 %) had unexpected, newly discovered lesions. Five eventually died of the disease, and two had no evidence of recurrence after a change in RT field and dose. In an event-based analysis at 2 months, rates of neck control (6/29 vs. 6/154, p = 0.001), distant metastases (3/29 vs. 4/154, p = 0.046), and disease-free survival (7/29 vs. 10/154, p = 0.003) were significantly higher in patients who received a second PET scan than in those who did not. The second pre-RT/CCRT PET scan was of particular benefit for detecting new lesions in OSCC patients with both ECS and lymph node standardized uptake value (SUV) of {>=}5.2 in the first PET scan. The present findings support the clinical value of pre-RT/CCRT FDG PET for defining treatment strategy in OSCC patients with both ECS and high nodal SUV, even when FDG PET had already been performed during the initial staging work-up. (orig.)

  8. High FDG uptake areas on pre-radiotherapy PET/CT identify preferential sites of local relapse after chemoradiotherapy for locally advanced oesophageal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Calais, Jeremie; Lemarignier, Charles; Vera, Pierre [Henri Becquerel Cancer Center and Rouen University Hospital, Nuclear Medicine Department, Rouen (France); University of Rouen, QuantIF-LITIS (Equipe d' Accueil 4108-FR CNRS 3638), Faculty of Medicine, Rouen (France); Dubray, Bernard [University of Rouen, QuantIF-LITIS (Equipe d' Accueil 4108-FR CNRS 3638), Faculty of Medicine, Rouen (France); Centre Henri Becquerel and Rouen University Hospital, Department of Radiotherapy and Medical Physics, Rouen (France); Nkhali, Lamyaa; Thureau, Sebastien; Modzelewski, Romain; Gardin, Isabelle [Henri Becquerel Cancer Center and Rouen University Hospital, Nuclear Medicine Department, Rouen (France); University of Rouen, QuantIF-LITIS (Equipe d' Accueil 4108-FR CNRS 3638), Faculty of Medicine, Rouen (France); Centre Henri Becquerel and Rouen University Hospital, Department of Radiotherapy and Medical Physics, Rouen (France); Di Fiore, Frederic [Rouen University Hospital, Department of Gastroenterology, Rouen (France); Rouen University Hospital, Department of Oncology, Henri Becquerel Cancer Center, IRON, Rouen (France); Michel, Pierre [Rouen University Hospital, Department of Gastroenterology, Rouen (France)

    2015-05-01

    The high failure rates in the radiotherapy (RT) target volume suggest that patients with locally advanced oesophageal cancer (LAOC) would benefit from increased total RT doses. High 2-deoxy-2-[{sup 18}F]fluoro-D-glucose (FDG) uptake (hotspot) on pre-RT FDG positron emission tomography (PET)/CT has been reported to identify intra-tumour sites at increased risk of relapse after RT in non-small cell lung cancer and in rectal cancer. Our aim was to confirm these observations in patients with LAOC and to determine the optimal maximum standardized uptake value (SUV{sub max}) threshold to delineate smaller RT target volumes that would facilitate RT dose escalation without impaired tolerance. The study included 98 consecutive patients with LAOC treated by chemoradiotherapy (CRT). All patients underwent FDG PET/CT at initial staging and during systematic follow-up in a single institution. FDG PET/CT acquisitions were coregistered on the initial CT scan. Various subvolumes within the initial tumour (30, 40, 50, 60, 70, 80 and 90 % SUV{sub max} thresholds) and in the subsequent local recurrence (LR, 40 and 90 % SUV{sub max} thresholds) were pasted on the initial CT scan and compared[Dice, Jaccard, overlap fraction (OF), common volume/baseline volume, common volume/recurrent volume]. Thirty-five patients had LR. The initial metabolic tumour volume was significantly higher in LR tumours than in the locally controlled tumours (mean 25.4 vs 14.2 cc; p = 0.002). The subvolumes delineated on initial PET/CT with a 30-60 % SUV{sub max} threshold were in good agreement with the recurrent volume at 40 % SUV{sub max} (OF = 0.60-0.80). The subvolumes delineated on initial PET/CT with a 30-60 % SUV{sub max} threshold were in good to excellent agreement with the core volume (90 % SUV{sub max}) of the relapse (common volume/recurrent volume and OF indices 0.61-0.89). High FDG uptake on pretreatment PET/CT identifies tumour subvolumes that are at greater risk of recurrence after CRT in

  9. Performance evaluation of the Ingenuity TF PET/CT scanner with a focus on high count-rate conditions

    Science.gov (United States)

    Kolthammer, Jeffrey A.; Su, Kuan-Hao; Grover, Anu; Narayanan, Manoj; Jordan, David W.; Muzic, Raymond F.

    2014-07-01

    This study evaluated the positron emission tomography (PET) imaging performance of the Ingenuity TF 128 PET/computed tomography (CT) scanner which has a PET component that was designed to support a wider radioactivity range than is possible with those of Gemini TF PET/CT and Ingenuity TF PET/MR. Spatial resolution, sensitivity, count rate characteristics and image quality were evaluated according to the NEMA NU 2-2007 standard and ACR phantom accreditation procedures; these were supplemented by additional measurements intended to characterize the system under conditions that would be encountered during quantitative cardiac imaging with 82Rb. Image quality was evaluated using a hot spheres phantom, and various contrast recovery and noise measurements were made from replicated images. Timing and energy resolution, dead time, and the linearity of the image activity concentration, were all measured over a wide range of count rates. Spatial resolution (4.8-5.1 mm FWHM), sensitivity (7.3 cps kBq-1), peak noise-equivalent count rate (124 kcps), and peak trues rate (365 kcps) were similar to those of the Gemini TF PET/CT. Contrast recovery was higher with a 2 mm, body-detail reconstruction than with a 4 mm, body reconstruction, although the precision was reduced. The noise equivalent count rate peak was broad (within 10% of peak from 241-609 MBq). The activity measured in phantom images was within 10% of the true activity for count rates up to those observed in 82Rb cardiac PET studies.

  10. Photophysical and photochemical effects of UV and VUV photo-oxidation and photolysis on PET and PEN

    Science.gov (United States)

    Morgan, Andrew

    Polyethylene Terephthalate (PET) is a widely used polymer in the bottling, packaging, and clothing industry. In recent years an increasing global demand for PET has taken place due to the Solar Disinfection (SODIS) process. SODIS is a method of sterilizing fresh water into drinkable water. The PET bottles are used in the process to contain the water during solar irradiation due to its highly transparent optical property. Alongside PET, polyethylene 2,6-napthalate (PEN) is used in bottling and flexible electronic applications. The surface of PEN would need to be modified to control the hydrophilicity and the interaction it exudes as a substrate. The UV light absorption properties of PET and PEN are of great importance for many applications, and thus needs to be studied along with its photochemical resistance. The optical and chemical nature of PET was studied as it was treated by UV photo-oxidation, photo-ozonation, and photolysis under atmospheric pressure. Another investigation was also used to study PEN and PET as they are treated by vacuum UV (VUV) photo-oxidation, VUV photolysis, and remote oxygen reactions. The extent of the photoreactions' effect into the depth of the polymers is examined as treatment conditions are changed. The different experimental methods established the rate of several competing photoreactions on PET and PEN during irradiance, and their effect on the optical quality of the polymers.

  11. PET/CT imaging of the diapeutic alkylphosphocholine analog 124I-CLR1404 in high and low-grade brain tumors.

    Science.gov (United States)

    Hall, Lance T; Titz, Benjamin; Robins, H Ian; Bednarz, Bryan P; Perlman, Scott B; Weichert, Jamey P; Kuo, John S

    2017-01-01

    CLR1404 is a cancer-selective alkyl phosphocholine (APC) analog that can be radiolabeled with 124I for PET imaging, 131I for targeted radiotherapy and/or SPECT imaging, or 125I for targeted radiotherapy. Studies have demonstrated avid CLR1404 uptake and prolonged retention in a broad spectrum of preclinical tumor models. The purpose of this pilot trial was to demonstrate avidity of 124I-CLR1404 in human brain tumors and develop a framework to evaluate this uptake for use in larger studies. 12 patients (8 men and 4 women; mean age of 43.9 ± 15.1 y; range 23-66 y) with 13 tumors were enrolled. Eleven patients had suspected tumor recurrence and 1 patient had a new diagnosis of high grade tumor. Patients were injected with 185 MBq ± 10% of 124I-CLR1404 followed by PET/CT imaging at 6-, 24-, and 48-hour. 124I-CLR1404 PET uptake was assessed qualitatively and compared with MRI. After PET image segmentation SUV values and tumor to background ratios were calculated. There was no significant uptake of 124I-CLR1404 in normal brain. In tumors, uptake tended to increase to 48 hours. Positive uptake was detected in 9 of 13 lesions: 5/5 high grade tumors, 1/2 low grade tumors, 1/1 meningioma, and 2/4 patients with treatment related changes. 124I-CLR1404 uptake was not detected in 1/2 low grade tumors, 2/4 lesions from treatment related changes, and 1/1 indeterminate lesion. For 6 malignant tumors, the average tumor to background ratios (TBR) were 9.32 ± 4.33 (range 3.46 to 15.42) at 24 hours and 10.04 ± 3.15 (range 5.17 to 13.17) at 48 hours. For 2 lesions from treatment related change, the average TBR were 5.05 ± 0.4 (range 4.76 to 5.33) at 24 hours and 4.88 ± 1.19 (range 4.04 to 5.72) at 48 hours. PET uptake had areas of both concordance and discordance compared with MRI. 124I-CLR1404 PET demonstrated avid tumor uptake in a variety of brain tumors with high tumor-to-background ratios. There were regions of concordance and discordance compared with MRI, which has

  12. Breeding for high water-use efficiency.

    Science.gov (United States)

    Condon, A G; Richards, R A; Rebetzke, G J; Farquhar, G D

    2004-11-01

    There is a pressing need to improve the water-use efficiency of rain-fed and irrigated crop production. Breeding crop varieties with higher water-use efficiency is seen as providing part of the solution. Three key processes can be exploited in breeding for high water-use efficiency: (i) moving more of the available water through the crop rather than it being wasted as evaporation from the soil surface or drainage beyond the root zone or being left behind in the root zone at harvest; (ii) acquiring more carbon (biomass) in exchange for the water transpired by the crop, i.e. improving crop transpiration efficiency; (iii) partitioning more of the achieved biomass into the harvested product. The relative importance of any one of these processes will vary depending on how water availability varies during the crop cycle. However, these three processes are not independent. Targeting specific traits to improve one process may have detrimental effects on the other two, but there may also be positive interactions. Progress in breeding for improved water-use efficiency of rain-fed wheat is reviewed to illustrate the nature of some of these interactions and to highlight opportunities that may be exploited in other crops as well as potential pitfalls. For C3 species, measuring carbon isotope discrimination provides a powerful means of improving water-use efficiency of leaf gas exchange, but experience has shown that improvements in leaf-level water-use efficiency may not always translate into higher crop water-use efficiency or yield. In fact, the reverse has frequently been observed. Reasons for this are explored in some detail. Crop simulation modelling can be used to assess the likely impact on water-use efficiency and yield of changing the expression of traits of interest. Results of such simulations indicate that greater progress may be achieved by pyramiding traits so that potential negative effects of individual traits are neutralized. DNA-based selection techniques may

  13. Expression of 58-kD Microspherule Protein (MSP58 is Highly Correlated with PET Imaging of Tumor Malignancy and Cell Proliferation in Glioma Patients

    Directory of Open Access Journals (Sweden)

    Wei Lin

    2016-02-01

    Full Text Available Background/Aims: The nucleolar 58-kDa microspherule protein (MSP58 has important transcriptional regulation functions and plays a crucial role in the tumorigenesis and progression of cancers. 3'-deoxy-3'-[18F]fluorothymidine (FLT has emerged as a promising positron emission tomography (PET tracer for evaluating tumor malignancy and cell proliferation. Methods: In the present study, the expression of MSP58 was evaluated by immunohistochemistry and the corresponding PET image was examined using FLT-PET in 55 patients with various grades of gliomas. Results: The immunoreactivity score (IRS of MSP58 increased with tumor grade with grade IV gliomas exhibiting the highest expression and showed a highly significant positive correlation with the Ki-67 index (r = 0.65, P r = 0.61, P r = 0.59, P Conclusion: These results indicate that MSP58 plays an important role in cell proliferation and will be one of the potential candidates of molecular therapy targeting proliferation. FLT-PET might be used as an early measure of treatment response in the proliferation-targeted therapy.

  14. Architecture of a Dual-Modality, High-Resolution, Fully Digital Positron Emission Tomography/Computed Tomography (PET/CT) Scanner for Small Animal Imaging

    Science.gov (United States)

    Fontaine, R.; Belanger, F.; Cadorette, J.; Leroux, J.-D.; Martin, J.-P.; Michaud, J.-B.; Pratte, J.-F.; Robert, S.; Lecomte, R.

    2005-06-01

    Contemporary positron emission tomography (PET) scanners are commonly implemented with very large scale integration analog front-end electronics to reduce power consumption, space, noise, and cost. Analog processing yields excellent results in dedicated applications, but offers little flexibility for sophisticated signal processing or for more accurate measurements with newer, fast scintillation crystals. Design goals of the new Sherbrooke PET/computed tomography (CT) scanner are: 1) to achieve 1 mm resolution in both emission (PET) and transmission (CT) imaging using the same detector channels; 2) to be able to count and discriminate individual X-ray photons in CT mode. These requirements can be better met by sampling the analog signal from each individual detector channel as early as possible, using off-the-shelf, 8-b, 100-MHz, high-speed analog-to-digital converters (ADC) and digital processing in field programmable gate arrays (FPGAs). The core of the processing units consists of Xilinx SpartanIIe that can hold up to 16 individual channels. The initial architecture is designed for 1024 channels, but modularity allows extending the system up to 10 K channels or more. This parallel architecture supports count rates in excess of a million hits/s/scintillator in CT mode and up to 100 K events/s/scintillator in PET mode, with a coincidence time window of less than 10 ns full-width at half-maximum.

  15. Gallium-68 Dotatate PET/CT is superior to other imaging modalities in the detection of medullary carcinoma of the thyroid in the presence of high serum calcitonin.

    Science.gov (United States)

    Tran, Kathryn; Khan, Sairah; Taghizadehasl, Mina; Palazzo, Fausto; Frilling, Andrea; Todd, Jeannie F; Al-Nahhas, Adil

    2015-01-01

    Medullary carcinoma of the thyroid (MTC) is a rare neuroendocrine tumour (NET) that expresses somatostatin receptors on the cell membrane and secretes calcitonin. Surgery is the primary curative modality but is achieved only when the diagnosis is timely so there is a high rate of persistent and recurrent disease indicated by a rise in the serum calcitonin levels. Successful management of recurrent disease requires accurate localisation with cross sectional and functional imaging. The introduction of gallium-68-Dotatate ((68)Ga-Dotatate) peptides positron emission tomography/computerized tomography (PET/CT) has significantly improved the detection of NET and has been reported as a valuable adjunct in MTC localisation. We retrospectively reviewed our cases of MTC to correlate the detectability of (68)Ga-Dotatate in relation to calcitonin levels and assess suitability of inoperable patients for peptide receptor radionuclide therapy (PRRT). Seven patients (age range 31-66 years, M:F 3:4) with raised calcitonin (mean=7,143pg/mL) were referred for (68)Ga-Dotatate PET/CT scan for localisation of persisting recurrent MTC. Six patients were known to have MTC treated with thyroidectomy and one patient was presenting for the first time. All patients had multiple imaging including ultrasound (US), CT, magnetic resonance imaging (MRI), fluorine-18-fluorodeoxyglucose ((18)F-FDG) PET/CT and iodine-123-metaiodobenzylguanidine ((123)I-MIBG). Positive findings were defined as areas of increased uptake other than the organs of normal distribution and were correlated with results of biopsies, other imaging, long term monitoring of calcitonin and clinical follow up. In 6/7 patients with very high serum calcitonin (range= 672-37,180, mean=8,320pg/mL) (68)Ga-Dotatate PET/CT confirmed the presence of active disease seen on other modalities or detected hitherto unsuspected lesions. In at least 3 cases, (68)Ga-Dotatate PET/CT showed many more lesions compared to other imaging combined. In 1

  16. Impact of attenuation correction strategies on the quantification of High Resolution Research Tomograph PET studies

    Energy Technology Data Exchange (ETDEWEB)

    Velden, Floris H P van [Department of Nuclear Medicine and PET Research, VU University Medical Centre, Amsterdam (Netherlands); Kloet, Reina W [Department of Nuclear Medicine and PET Research, VU University Medical Centre, Amsterdam (Netherlands); Berckel, Bart N M van [Department of Nuclear Medicine and PET Research, VU University Medical Centre, Amsterdam (Netherlands); Molthoff, Carla F M [Department of Nuclear Medicine and PET Research, VU University Medical Centre, Amsterdam (Netherlands); Jong, Hugo W A M de [Department of Nuclear Medicine, University Medical Centre Utrecht, Utrecht (Netherlands); Lammertsma, Adriaan A [Department of Nuclear Medicine and PET Research, VU University Medical Centre, Amsterdam (Netherlands); Boellaard, Ronald [Department of Nuclear Medicine and PET Research, VU University Medical Centre, Amsterdam (Netherlands)

    2008-01-07

    In this study, the quantitative accuracy of different attenuation correction strategies presently available for the High Resolution Research Tomograph (HRRT) was investigated. These attenuation correction methods differ in reconstruction and processing (segmentation) algorithms used for generating a {mu}-image from measured 2D transmission scans, an intermediate step in the generation of 3D attenuation correction factors. Available methods are maximum-a-posteriori reconstruction (MAP-TR), unweighted OSEM (UW-OSEM) and NEC-TR, which transforms sinogram values back to their noise equivalent counts (NEC) to restore Poisson distribution. All methods can be applied with or without {mu}-image segmentation. However, for MAP-TR a {mu}-histogram is a prior during reconstruction. All possible strategies were evaluated using phantoms of various sizes, simulating preclinical and clinical situations. Furthermore, effects of emission contamination of the transmission scan on the accuracy of various attenuation correction strategies were studied. Finally, the accuracy of various attenuation corrections strategies and its relative impact on the reconstructed activity concentration (AC) were evaluated using small animal and human brain studies. For small structures, MAP-TR with human brain priors showed smaller differences in {mu}-values for transmission scans with and without emission contamination (<8%) than the other methods (<26%). In addition, it showed best agreement with true AC (deviation <4.5%). A specific prior designed to take into account the presence of small animal fixation devices only very slightly improved AC precision to 4.3%. All methods scaled {mu}-values of a large homogeneous phantom to within 4% of the water peak, but MAP-TR provided most accurate AC after reconstruction. However, for clinical data MAP-TR using the default prior settings overestimated the thickness of the skull, resulting in overestimations of {mu}-values in regions near the skull and thus in

  17. PET/MRI. Challenges, solutions and perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Herzog, Hans [Forschungszentrum Juelich (Germany). Inst. of Neuroscience and Medicine - 4

    2012-07-01

    Already from the start of PET/CT integrating positron emission tomography (PET) and computed tomography (CT) in one instrument, there have been considerations how to combine PET and magnetic resonance imaging (MRI) so that their complementary abilities can be utilized in a single investigation. Since classical PET electronics fail in an even weak magnetic field and PET signal processing might disturb high-frequency signals of MRI, it soon became clear that new solutions had to be found to avoid mutual interferences. During the last fifteen years a number of different approaches towards PET/MRI for small animal imaging have been developed by research groups which together with their specific features are summarized in this review. Recently, PET/MRI for human imaging became available as well - this time by industrial initiatives. First some prototypes of BrainPET/MRI were developed followed by commercial products for simultaneous and non-simultaneous whole-body PET/MRI. Although only PET/MRI integrated in one scanner offers the full diversity of complementary multiparametric imaging, there are also promising applications of non-simultaneous sequential PET/MRI. While describing the present instrumentation for human PET/MRI, this review discusses the challenges and promises related to this new imaging technology. (orig.)

  18. Polyesteramides based on PET

    NARCIS (Netherlands)

    Bouma, K.

    1999-01-01

    Engineering plastics have good mechanical, thermal and electrical properties, and can be easily processed. Typical engineering plastics include polyamides (PA6,6, PA6, PA4,6) and polyesters (PBT, PET). Compared to polyesters of a similar structure, polyamides have a high glass transition (Tg) and

  19. Highly conductive and anticorrosion Ag/CNTs/NDs hybrid films on molecular-grafted PET substrate for flexible electrodes

    Science.gov (United States)

    Zhang, Yang; Kang, Zhixin

    2018-01-01

    We reported an approach of preparing highly conductive, anticorrosion, flexible Ag hybrid films enhanced by multi-walled carbon nanotubes (CNTs) and nanodaimonds (NDs) on molecular-grafted PET substrate by spin-spray for flexible electronics. we studied in this paper and found that even an outstanding enhancement on conductivity of Ag films, CNTs have a negative effect on anticorrosion property. Meanwhile, NDs decreased the conductivity of Ag/CNTs hybrids, but it remained a relatively high conductivity property and even was affirmed a distinctly boost improvement on anticorrosion, microhardness and tensile strength, which meant a better mechanical chemical stabilization and practicability in real flexible electronics. To obtain the strong adhesive strength of films/substrate, molecular-grafting technology was applied, which was affirmed by XPS and cross-cut test. What's more, we evaluated anticorrosion property by electrochemistry test, including Tafel measurements and electrochemical impedance spectroscopy measurements, proving the positive effect of NDs on Ag/CNTs hybrid films. For practical application, a flexible light-emitting diode (LED) circuit was successfully structured and remained steady under bending, folding and twisting. Besides, after 1000000 cycles inner/outer bending deformation, the hybrid films showed a mechanical compliance, fatigue stability and practicability in real flexible electronics.

  20. cMiCE a high resolution animal PET using continuous LSO with a statistics based positioning scheme

    CERN Document Server

    Joung Jin Hun; Lewellen, T K

    2002-01-01

    Objective: Detector designs for small animal scanners are currently dominated by discrete crystal implementations. However, given the small crystal cross-sections required to obtain very high resolution, discrete designs are typically expensive, have low packing fraction, reduced light collection, and are labor intensive to build. To overcome these limitations we have investigated the feasibility of using a continuous miniature crystal element (cMiCE) detector module for high resolution small animal PET applications. Methods: The detector module consists of a single continuous slab of LSO, 25x25 mm sup 2 in exposed cross-section and 4 mm thick, coupled directly to a PS-PMT (Hamamatsu R5900-00-C12). The large area surfaces of the crystal were polished and painted with TiO sub 2 and the short surfaces were left unpolished and painted black. Further, a new statistics based positioning (SBP) algorithm has been implemented to address linearity and edge effect artifacts that are inherent with conventional Anger sty...

  1. An experimental phantom study of the effect of gadolinium-based MR contrast agents on PET attenuation coefficients and PET quantification in PET-MR imaging: application to cardiac studies.

    Science.gov (United States)

    O' Doherty, Jim; Schleyer, Paul

    2017-12-01

    Simultaneous cardiac perfusion studies are an increasing trend in PET-MR imaging. During dynamic PET imaging, the introduction of gadolinium-based MR contrast agents (GBCA) at high concentrations during a dual injection of GBCA and PET radiotracer may cause increased attenuation effects of the PET signal, and thus errors in quantification of PET images. We thus aimed to calculate the change in linear attenuation coefficient (LAC) of a mixture of PET radiotracer and increasing concentrations of GBCA in solution and furthermore, to investigate if this change in LAC produced a measurable effect on the image-based PET activity concentration when attenuation corrected by three different AC strategies. We performed simultaneous PET-MR imaging of a phantom in a static scenario using a fixed activity of 40 MBq [18 F]-NaF, water, and an increasing GBCA concentration from 0 to 66 mM (based on an assumed maximum possible concentration of GBCA in the left ventricle in a clinical study). This simulated a range of clinical concentrations of GBCA. We investigated two methods to calculate the LAC of the solution mixture at 511 keV: (1) a mathematical mixture rule and (2) CT imaging of each concentration step and subsequent conversion to LAC at 511 keV. This comparison showed that the ranges of LAC produced by both methods are equivalent with an increase in LAC of the mixed solution of approximately 2% over the range of 0-66 mM. We then employed three different attenuation correction methods to the PET data: (1) each PET scan at a specific millimolar concentration of GBCA corrected by its corresponding CT scan, (2) each PET scan corrected by a CT scan with no GBCA present (i.e., at 0 mM GBCA), and (3) a manually generated attenuation map, whereby all CT voxels in the phantom at 0 mM were replaced by LAC = 0.1 cm-1. All attenuation correction methods (1-3) were accurate to the true measured activity concentration within 5%, and there were no trends in image

  2. Performance of highly sensitive cardiac troponin T assay to detect ischaemia at PET-CT in low-risk patients with acute coronary syndrome: a prospective observational study.

    Science.gov (United States)

    Morawiec, Beata; Fournier, Stephane; Tapponnier, Maxime; Prior, John O; Monney, Pierre; Dunet, Vincent; Lauriers, Nathalie; Recordon, Frederique; Trana, Catalina; Iglesias, Juan-Fernando; Kawecki, Damian; Boulat, Olivier; Bardy, Daniel; Lamsidri, Sabine; Eeckhout, Eric; Hugli, Olivier; Muller, Olivier

    2017-07-10

    Highly sensitive troponin T (hs-TnT) assay has improved clinical decision-making for patients admitted with chest pain. However, this assay's performance in detecting myocardial ischaemia in a lowrisk population has been poorly documented. To assess hs-TnT assay's performance to detect myocardial ischaemia at positron emission tomography/CT (PET-CT) in low-risk patients admitted with chest pain. Patients admitted for chest pain with a nonconclusive ECG and negative standard cardiac troponin T results at admission and after 6 hours were prospectively enrolled. Their hs-TnT samples were at T0, T2 and T6. Physicians were blinded to hs-TnT results. All patients underwent a PET-CT at rest and during adenosine-induced stress. All patients with a positive PET-CT result underwent a coronary angiography. Forty-eight patients were included. Six had ischaemia at PET-CT. All of them had ≥1 significant stenosis at coronary angiography. Areas under the curve (95% CI) for predicting significant ischaemia at PET-CT using hs-TnT were 0.764 (0.515 to 1.000) at T0, 0.812(0.616 to 1.000) at T2 and 0.813(0.638 to 0.989) at T6. The receiver operating characteristicbased optimal cut-off value for hs-TnT at T0, T2 and T6 needed to exclude significant ischaemia at PET-CT was <4 ng/L. Using this value, sensitivity, specificity, positive and negative predictive values of hs-TnT to predict significant ischaemia were 83%/38%/16%/94% at T0, 100%/40%/19%/100% at T2 and 100%/43%/20%/100% at T6, respectively. Our findings suggest that in low-risk patients, using the hs-TnT assay with a cut-off value of 4 ng/L demonstrates excellent negative predictive value to exclude myocardial ischaemia detection at PET-CT, at the expense of weak specificity and positive predictive value. ClinicalTrials.gov Identifier: NCT01374607. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly

  3. Role of pharmacokinetic parameters derived with high temporal resolution DCE MRI using simultaneous PET/MRI system in breast cancer: A feasibility study.

    Science.gov (United States)

    Jena, Amarnath; Taneja, Sangeeta; Singh, Aru; Negi, Pradeep; Mehta, Shashi Bhushan; Sarin, Ramesh

    2017-01-01

    To evaluate the reliability of pharmacokinetic parameters like K(trans), Kep and ve derived through DCE MRI breast protocol using 3T Simultaneous PET/MRI (3Tesla Positron Emission Tomography/Magnetic Resonance Imaging) system in distinguishing benign and malignant lesions. High temporal resolution DCE (Dynamic Contrast Enhancement) MRI performed as routine breast MRI for diagnosis or as a part of PET/MRI for cancer staging using a 3T simultaneous PET/MRI system in 98 women having 109 breast lesions were analyzed for calculation of pharmacokinetic parameters (K(trans), ve, and Kep) at 60s time point using an in-house developed computation scheme. Receiver operating characteristic (ROC) curve analysis revealed a cut off value for K(trans), Kep, ve as 0.50, 2.59, 0.15 respectively which reliably distinguished benign and malignant breast lesions. Data analysis revealed an overall accuracy of 94.50%, 79.82% and 87.16% for K(trans), Kep, ve respectively. Introduction of native T1 normalization with an externally placed phantom showed a higher accuracy (94.50%) than without native T1 normalization (93.50%) with an increase in specificity of 87% vs 84%. Overall the results indicate that reliable measurement of pharmacokinetic parameters with reduced acquisition time is feasible in a 3TMRI embedded PET/MRI system with reasonable accuracy and application may be extended to exploit the potential of simultaneous PET/MRI in further work on breast cancer. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  4. Pet Allergy

    Science.gov (United States)

    ... develop bacterial infections of the sinuses, such as sinusitis. Asthma People with asthma and pet allergy often have difficulty managing asthma symptoms. They may be at risk of asthma attacks that require immediate medical treatment or emergency care. Prevention If you don't ...

  5. Comparison of 3D Maximum A Posteriori and Filtered Backprojection algorithms for high resolution animal imaging in microPET

    Energy Technology Data Exchange (ETDEWEB)

    Chatziioannou, A.; Qi, J.; Moore, A.; Annala, A.; Nguyen, K.; Leahy, R.M.; Cherry, S.R.

    2000-01-01

    We have evaluated the performance of two three dimensional reconstruction algorithms with data acquired from microPET, a high resolution tomograph dedicated to small animal imaging. The first was a linear filtered-backprojection algorithm (FBP) with reprojection of the missing data and the second was a statistical maximum-aposteriori probability algorithm (MAP). The two algorithms were evaluated in terms of their resolution performance, both in phantoms and in vivo. Sixty independent realizations of a phantom simulating the brain of a baby monkey were acquired, each containing 3 million counts. Each of these realizations was reconstructed independently with both algorithms. The ensemble of the sixty reconstructed realizations was used to estimate the standard deviation as a measure of the noise for each reconstruction algorithm. More detail was recovered in the MAP reconstruction without an increase in noise relative to FBP. Studies in a simple cylindrical compartment phantom demonstrated improved recovery of known activity ratios with MAP. Finally in vivo studies also demonstrated a clear improvement in spatial resolution using the MAP algorithm. The quantitative accuracy of the MAP reconstruction was also evaluated by comparison with autoradiography and direct well counting of tissue samples and was shown to be superior.

  6. Comparison of manual and automatic techniques for substriatal segmentation in 11C-raclopride high-resolution PET studies.

    Science.gov (United States)

    Johansson, Jarkko; Alakurtti, Kati; Joutsa, Juho; Tohka, Jussi; Ruotsalainen, Ulla; Rinne, Juha O

    2016-10-01

    The striatum is the primary target in regional C-raclopride-PET studies, and despite its small volume, it contains several functional and anatomical subregions. The outcome of the quantitative dopamine receptor study using C-raclopride-PET depends heavily on the quality of the region-of-interest (ROI) definition of these subregions. The aim of this study was to evaluate subregional analysis techniques because new approaches have emerged, but have not yet been compared directly. In this paper, we compared manual ROI delineation with several automatic methods. The automatic methods used either direct clustering of the PET image or individualization of chosen brain atlases on the basis of MRI or PET image normalization. State-of-the-art normalization methods and atlases were applied, including those provided in the FreeSurfer, Statistical Parametric Mapping8, and FSL software packages. Evaluation of the automatic methods was based on voxel-wise congruity with the manual delineations and the test-retest variability and reliability of the outcome measures using data from seven healthy male participants who were scanned twice with C-raclopride-PET on the same day. The results show that both manual and automatic methods can be used to define striatal subregions. Although most of the methods performed well with respect to the test-retest variability and reliability of binding potential, the smallest average test-retest variability and SEM were obtained using a connectivity-based atlas and PET normalization (test-retest variability=4.5%, SEM=0.17). The current state-of-the-art automatic ROI methods can be considered good alternatives for subjective and laborious manual segmentation in C-raclopride-PET studies.

  7. Microfluidics without channels: highly-flexible synthesis on a digital-microfluidic chip for production of diverse PET tracers

    Energy Technology Data Exchange (ETDEWEB)

    Van Dam, Robert Michael [Univ. of California, Los Angeles, CA (United States)

    2010-09-01

    Positron emission tomography (PET) imaging is used for fundamental studies of living biological organisms and microbial ecosystems in applications ranging from biofuel production to environmental remediation to the study, diagnosis, and treatment monitoring of human disease. Routine access to PET imaging, to monitor biochemical reactions in living organisms in real time, could accelerate a broad range of research programs of interest to DOE. Using PET requires access to short-lived radioactive-labeled compounds that specifically probe the desired living processes. The overall aims of this project were to develop a miniature liquid-handling technology platform (called “microfluidics”) that increases the availability of diverse PET probes by reducing the cost and complexity of their production. Based on preliminary experiments showing that microfluidic chips can synthesis such compounds, we aimed to advance this technology to improve its robustness, increase its flexibility for a broad range of probes, and increase its user-friendliness. Through the research activities of this project, numerous advances were made; Tools were developed to enable the visualization of radioactive materials within microfluidic chips; Fundamental advances were made in the microfluidic chip architecture and fabrication process to increase its robustness and reliability; The microfluidic chip technology was shown to produce useful quantities of an example PET probes, and methods to further increase the output were successfully pursued; A “universal” chip was developed that could produce multiple types of PET probes, enabling the possibility of “on demand” synthesis of different probes; and Operation of the chip was automated to ensure minimal radiation exposure to the operator Based on the demonstrations of promising technical feasibility and performance, the microfluidic chip technology is currently being commercialized. It is anticipated that costs of microfluidic chips can be

  8. Performance evaluation of a high-resolution brain PET scanner using four-layer MPPC DOI detectors

    Science.gov (United States)

    Watanabe, Mitsuo; Saito, Akinori; Isobe, Takashi; Ote, Kibo; Yamada, Ryoko; Moriya, Takahiro; Omura, Tomohide

    2017-09-01

    A high-resolution positron emission tomography (PET) scanner, dedicated to brain studies, was developed and its performance was evaluated. A four-layer depth of interaction detector was designed containing five detector units axially lined up per layer board. Each of the detector units consists of a finely segmented (1.2 mm) LYSO scintillator array and an 8  ×  8 array of multi-pixel photon counters. Each detector layer has independent front-end and signal processing circuits, and the four detector layers are assembled as a detector module. The new scanner was designed to form a detector ring of 430 mm diameter with 32 detector modules and 168 detector rings with a 1.2 mm pitch. The total crystal number is 655 360. The transaxial and axial field of views (FOVs) are 330 mm in diameter and 201.6 mm, respectively, which are sufficient to measure a whole human brain. The single-event data generated at each detector module were transferred to the data acquisition servers through optical fiber cables. The single-event data from all detector modules were merged and processed to create coincidence event data in on-the-fly software in the data acquisition servers. For image reconstruction, the high-resolution mode (HR-mode) used a 1.2 mm2 crystal segment size and the high-speed mode (HS-mode) used a 4.8 mm2 size by collecting 16 crystal segments of 1.2 mm each to reduce the computational cost. The performance of the brain PET scanner was evaluated. For the intrinsic spatial resolution of the detector module, coincidence response functions of the detector module pair, which faced each other at various angles, were measured by scanning a 0.25 mm diameter 22Na point source. The intrinsic resolutions were obtained with 1.08 mm full width at half-maximum (FWHM) and 1.25 mm FWHM on average at 0 and 22.5 degrees in the first layer pair, respectively. The system spatial resolutions were less than 1.0 mm FWHM throughout the whole FOV, using a

  9. HIGH RESOLUTION AIRBORNE SHALLOW WATER MAPPING

    Directory of Open Access Journals (Sweden)

    F. Steinbacher

    2012-07-01

    Full Text Available In order to meet the requirements of the European Water Framework Directive (EU-WFD, authorities face the problem of repeatedly performing area-wide surveying of all kinds of inland waters. Especially for mid-sized or small rivers this is a considerable challenge imposing insurmountable logistical efforts and costs. It is therefore investigated if large-scale surveying of a river system on an operational basis is feasible by employing airborne hydrographic laser scanning. In cooperation with the Bavarian Water Authority (WWA Weilheim a pilot project was initiated by the Unit of Hydraulic Engineering at the University of Innsbruck and RIEGL Laser Measurement Systems exploiting the possibilities of a new LIDAR measurement system with high spatial resolution and high measurement rate to capture about 70 km of riverbed and foreland for the river Loisach in Bavaria/Germany and the estuary and parts of the shoreline (about 40km in length of lake Ammersee. The entire area surveyed was referenced to classic terrestrial cross-section surveys with the aim to derive products for the monitoring and managing needs of the inland water bodies forced by the EU-WFD. The survey was performed in July 2011 by helicopter and airplane and took 3 days in total. In addition, high resolution areal images were taken to provide an optical reference, offering a wide range of possibilities on further research, monitoring, and managing responsibilities. The operating altitude was about 500 m to maintain eye-safety, even for the aided eye, the airspeed was about 55 kts for the helicopter and 75 kts for the aircraft. The helicopter was used in the alpine regions while the fixed wing aircraft was used in the plains and the urban area, using appropriate scan rates to receive evenly distributed point clouds. The resulting point density ranged from 10 to 25 points per square meter. By carefully selecting days with optimum water quality, satisfactory penetration down to the river

  10. High Resolution Airborne Shallow Water Mapping

    Science.gov (United States)

    Steinbacher, F.; Pfennigbauer, M.; Aufleger, M.; Ullrich, A.

    2012-07-01

    In order to meet the requirements of the European Water Framework Directive (EU-WFD), authorities face the problem of repeatedly performing area-wide surveying of all kinds of inland waters. Especially for mid-sized or small rivers this is a considerable challenge imposing insurmountable logistical efforts and costs. It is therefore investigated if large-scale surveying of a river system on an operational basis is feasible by employing airborne hydrographic laser scanning. In cooperation with the Bavarian Water Authority (WWA Weilheim) a pilot project was initiated by the Unit of Hydraulic Engineering at the University of Innsbruck and RIEGL Laser Measurement Systems exploiting the possibilities of a new LIDAR measurement system with high spatial resolution and high measurement rate to capture about 70 km of riverbed and foreland for the river Loisach in Bavaria/Germany and the estuary and parts of the shoreline (about 40km in length) of lake Ammersee. The entire area surveyed was referenced to classic terrestrial cross-section surveys with the aim to derive products for the monitoring and managing needs of the inland water bodies forced by the EU-WFD. The survey was performed in July 2011 by helicopter and airplane and took 3 days in total. In addition, high resolution areal images were taken to provide an optical reference, offering a wide range of possibilities on further research, monitoring, and managing responsibilities. The operating altitude was about 500 m to maintain eye-safety, even for the aided eye, the airspeed was about 55 kts for the helicopter and 75 kts for the aircraft. The helicopter was used in the alpine regions while the fixed wing aircraft was used in the plains and the urban area, using appropriate scan rates to receive evenly distributed point clouds. The resulting point density ranged from 10 to 25 points per square meter. By carefully selecting days with optimum water quality, satisfactory penetration down to the river bed was achieved

  11. The pre therapeutic PET-F.D.G. predicts the survival in the high grade gliomas independently of consensual prognosis factors; La TEP-FDG pretherapeutique predit la survie dans les gliomes de haut grade independamment des facteurs pronostiques consensuels

    Energy Technology Data Exchange (ETDEWEB)

    Colavolpe, C.; Guedj, E.; Mancini, J.; Bequet-Boucard, C.; Metellus, P.; Barrie, M.; Figarella-Branger, D.; Chinot, O.; Mundler, O. [CHU La Timone, Marseille, (France)

    2009-05-15

    The objective of this study is to evaluate the prognosis value independent of the pre-therapy PET-F.D.G. on the global survival and without progression of high grade gliomas, in comparison with the consensual prognosis factors. In conclusion, the comparison between the tumor and contralateral maximal fixation on the preoperative PET-F.D.G. brings a supplementary prognosis information for the management of high grade gliomas, independently of the consensual prognosis factors. (N.C.)

  12. Tsunamis: Water Quality

    Science.gov (United States)

    ... Transmission in Pet Shelters Protect Your Pets Tsunamis: Water Quality Language: English Español (Spanish) Recommend on Facebook ... about testing should be directed to local authorities. Water for Drinking, Cooking, and Personal Hygiene Safe water ...

  13. High prevalence of extended-spectrum β-lactamase, plasmid-mediated AmpC, and carbapenemase genes in pet food.

    Science.gov (United States)

    Seiffert, Salome N; Carattoli, Alessandra; Tinguely, Regula; Lupo, Agnese; Perreten, Vincent; Endimiani, Andrea

    2014-10-01

    We evaluated the pet food contained in 30 packages as a potential origin of extended-spectrum cephalosporin-resistant Gram-negative organisms and β-lactamase genes (bla). Live bacteria were not detected by selective culture. However, PCR investigations on food DNA extracts indicated that samples harbored the blaCTX-M-15 (53.3%), blaCMY-4 (20%), and blaVEB-4-like (6.7%) genes. Particularly worrisome was the presence of blaOXA-48-like carbapenemases (13.3%). The original pet food ingredients and/or the production processes were highly contaminated with bacteria carrying clinically relevant acquired bla genes. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  14. Multimodality Image Fusion with PSMA PET/CT and High-Intensity Focused Ultrasound Focal Therapy for Primary Diagnosis and Management of Prostate Cancer: A Planned Research Initiative

    Directory of Open Access Journals (Sweden)

    Marcia C. Javitt

    2017-10-01

    Full Text Available Recent developments in diagnostic imaging herald a new approach to diagnosis and management of prostate cancer. Multimodality fusion that combines anatomic with functional imaging data has surpassed either of the two alone. This opens up the possibility to “find and fix” malignancy with greater accuracy than ever before. This is particularly important for prostate cancer because it is the most common male cancer in most developed countries. This article describes technical advances under investigation at our institution and others using multimodality image fusion of magnetic resonance imaging (MRI, transrectal ultrasound (TRUS, and PSMA PET/CT (defined as the combination of prostate-specific membrane antigen [PSMA], positron emission tomography [PET], and computed tomography [CT] for personalized medicine in the diagnosis and focal therapy of prostate cancer with high-intensity focused ultrasound (HiFUS.

  15. An intra-individual comparison of MRI, [18F]-FET and [18F]-FLT PET in patients with high-grade gliomas.

    Directory of Open Access Journals (Sweden)

    Martha Nowosielski

    Full Text Available OBJECTIVES: Intra-individual spatial overlap analysis of tumor volumes assessed by MRI, the amino acid PET tracer [18F]-FET and the nucleoside PET tracer [18F]-FLT in high-grade gliomas (HGG. METHODS: MRI, [18F]-FET and [18F]-FLT PET data sets were retrospectively analyzed in 23 HGG patients. Morphologic tumor volumes on MRI (post-contrast T1 (cT1 and T2 images were calculated using a semi-automatic image segmentation method. Metabolic tumor volumes for [18F]-FET and [18F]-FLT PETs were determined by image segmentation using a threshold-based volume of interest analysis. After co-registration with MRI the morphologic and metabolic tumor volumes were compared on an intra-individual basis in order to estimate spatial overlaps using the Spearman's rank correlation coefficient and the Mann-Whitney U test. RESULTS: [18F]-FLT uptake was negative in tumors with no or only moderate contrast enhancement on MRI, detecting only 21 of 23 (91% HGG. In addition, [18F]-FLT uptake was mainly restricted to cT1 tumor areas on MRI and [18F]-FLT volumes strongly correlated with cT1 volumes (r = 0.841, p<0.001. In contrast, [18F]-FET PET detected 22 of 23 (96% HGG. [18F]-FET uptake beyond areas of cT1 was found in 61% of cases and [18F]-FET volumes showed only a moderate correlation with cT1 volumes (r = 0.573, p<0.001. Metabolic tumor volumes beyond cT1 tumor areas were significantly larger for [18F]-FET compared to [18F]-FLT tracer uptake (8.3 vs. 2.7 cm3, p<0.001. CONCLUSION: In HGG [18F]-FET but not [18F]-FLT PET was able to detect metabolic active tumor tissue beyond contrast enhancing tumor on MRI. In contrast to [18F]-FET, blood-brain barrier breakdown seems to be a prerequisite for [18F]-FLT tracer uptake.

  16. Biphasic {sup 68}Ga-PSMA-HBED-CC-PET/CT in patients with recurrent and high-risk prostate carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Sahlmann, Carsten-Oliver; Meller, Birgit; Bouter, Caroline; Meller, Johannes [University Medical Center Goettingen, Department of Nuclear Medicine, Goettingen (Germany); Ritter, Christian Oliver; Lotz, Joachim [University Medical Center Goettingen, Department of Diagnostic and Interventional Radiology, Goettingen (Germany); Stroebel, Philipp [University Medical Center Goettingen, Department of Pathology, Goettingen (Germany); Trojan, Lutz; Hijazi, Sameh [University Medical Center Goettingen, Department of Urology, Goettingen (Germany)

    2016-05-15

    Binding of {sup 68}Ga-PSMA-HBED-CC ({sup 68}Ga-PSMA) at prostate cancer (PC) cells increases over time. A biphasic protocol may help separating benign from tumor lesions. The aim of this study was the retrospective evaluation of a diagnostic incremental value of a dual-time point (biphasic) {sup 68}Ga-PSMA-PET/CT in patients with prostate cancer. Retrospective analysis of 35 consecutive patients (49-78 years, median 71) with newly diagnosed PC (12/35) or recurrence of PC (23/35). PET/CT (Gemini TF16, Philips) was acquired 1 h and 3 h p. i. of 140-392 MBq (300 MBq median) {sup 68}Ga-PSMA, followed by a diagnostic contrast CT. PET findings were correlated with histology or unequivocal CT findings. Semiquantitative PET data (SUVmax, SUV mean) were acquired and target-to-background-ratios (T/B-ratio) were calculated for benign and malign lesions for both time points. Size of lymph nodes (LN) on diagnostic CT was recorded. Statistical analysis was performed for assessment of significant changes of semiquantitative PET-parameters over time and for correlation of size and uptake of lymph nodes. One hundred and four lesions were evaluated. Sixty lesions were referenced by histology or unequivocal CT findings, including eight (13.3 %) histopathologically benign lymph nodes, 12 (20 %) histopathologically lymph node metastases, 12 (20 %) primary tumors, three (5 %) local recurrences, and 25 (41.7 %) bone metastases. Forty-four lesions were axillary LN with normal CT-appearance. Benign lesions had significantly lower SUVmax and T/B-ratios compared with malignant findings. Malign lesions showed a significant increase of both parameters over time compared to benign findings. There was no correlation between LN size and SUVmax. The sensitivity, specificity, the positive predictive value and negative predictive value of PET/CT regarding pelvic LN was 94 %, 99 %, 89 %, and 99.5 %, respectively. In contrast to benign tissues, the uptake of proven tumor lesions increases on {sup 68

  17. Nutritional sustainability of pet foods.

    Science.gov (United States)

    Swanson, Kelly S; Carter, Rebecca A; Yount, Tracy P; Aretz, Jan; Buff, Preston R

    2013-03-01

    Sustainable practices meet the needs of the present without compromising the ability of future generations to meet their needs. Applying these concepts to food and feed production, nutritional sustainability is the ability of a food system to provide sufficient energy and essential nutrients required to maintain good health in a population without compromising the ability of future generations to meet their nutritional needs. Ecological, social, and economic aspects must be balanced to support the sustainability of the overall food system. The nutritional sustainability of a food system can be influenced by several factors, including the ingredient selection, nutrient composition, digestibility, and consumption rates of a diet. Carbon and water footprints vary greatly among plant- and animal-based ingredients, production strategy, and geographical location. Because the pet food industry is based largely on by-products and is tightly interlinked with livestock production and the human food system, however, it is quite unique with regard to sustainability. Often based on consumer demand rather than nutritional requirements, many commercial pet foods are formulated to provide nutrients in excess of current minimum recommendations, use ingredients that compete directly with the human food system, or are overconsumed by pets, resulting in food wastage and obesity. Pet food professionals have the opportunity to address these challenges and influence the sustainability of pet ownership through product design, manufacturing processes, public education, and policy change. A coordinated effort across the industry that includes ingredient buyers, formulators, and nutritionists may result in a more sustainable pet food system.

  18. Water Wisdom: 23 Stand-Alone Activities on Water Supply and Water Conservation for High School Students. 2nd Edition.

    Science.gov (United States)

    Massachusetts State Water Resources Authority, Boston.

    This water conservation education program for high schools consists of both stand-alone activities and teacher support materials. Lessons are divided into six broad categories: (1) The Water Cycle; (2) Water and Society; (3) Keeping Water Pure; (4) Visualizing Volumes; (5) The Economics of Water Use; and (6) Domestic Water Conservation. The…

  19. Evacuating People and Their Pets: Older Floridians' Need for and Proximity to Pet-Friendly Shelters.

    Science.gov (United States)

    Douglas, Rachel; Kocatepe, Ayberk; Barrett, Anne E; Ozguven, Eren Erman; Gumber, Clayton

    2017-10-04

    Pets influence evacuation decisions, but little is known about pet-friendly emergency shelters' availability or older adults' need for them. Our study addresses this issue, focusing on the most densely populated area of Florida (Miami-Dade)-the state with the oldest population and greatest hurricane susceptibility. We use Geographic Information Systems (GIS)-based methodology to identify the shortest paths to pet-friendly shelters, based on distance and congested and uncongested travel times-taking into account the older population's spatial distribution. Logistic regression models using the 2013 American Housing Survey's Disaster Planning Module examine anticipated shelter use as a function of pet ownership and requiring pet evacuation assistance. Thirty-four percent of older adults in the Miami-Dade area have pets-35% of whom report needing pet evacuation assistance. However, GIS accessibility measures show that travel time factors are likely to impede older adults' use of the area's few pet-friendly shelters. Logistic regression results reveal that pet owners are less likely to report anticipating shelter use; however, the opposite holds for pet owners reporting they would need help evacuating their pets-they anticipate using shelters. High pet shelter need coupled with low availability exacerbates older adults' heightened vulnerability during Florida's hurricane season.

  20. Role of Cardiac PET in Clinical Practice.

    Science.gov (United States)

    Salata, Brian M; Singh, Parmanand

    2017-11-09

    Early identification of atherosclerosis and at-risk lesions plays a critical role in reducing the burden of cardiovascular disease. While invasive coronary angiography serves as the gold standard for diagnosing coronary artery disease, non-invasive imaging techniques provide visualization of both anatomical and functional atherosclerotic processes prior to clinical presentation. The development of cardiac positron emission tomography (PET) has greatly enhanced our capability to diagnose and treat patients with early stages of atherosclerosis. Cardiac PET is a powerful, versatile non-invasive diagnostic tool with utility in the identification of high-risk plaques, myocardial perfusion defects, and viable myocardial tissue. Cardiac PET allows for comparisons of myocardial function both at time of rest and stress, providing accurate assessments of both myocardial perfusion and viability. Furthermore, novel PET techniques with unique radiotracers yield clinically relevant data on high-risk plaques in active progressive atherosclerosis. While PET exercise stress tests were previously difficult to perform given short radiotracer half-life, the development of the novel radiotracer Flurpiridaz F-18 provides a promising future for PET exercise stress imaging. In addition, hybrid imaging with computed tomography angiography (CTA) and cardiac magnetic resonance (CMR) provides integration of cardiac function and structure. In this review article, we discuss the principles of cardiac PET, the clinical applications of PET in diagnosing and prognosticating patients at risk for future cardiovascular events, compare PET with other non-invasive cardiac imaging modalities, and discuss future applications of PET in CVD evaluation and management.

  1. Quantitation of regional cerebral blood flow corrected for partial volume effect using O-15 water and PET

    DEFF Research Database (Denmark)

    Iida, H; Law, I; Pakkenberg, B

    2000-01-01

    Limited spatial resolution of positron emission tomography (PET) can cause significant underestimation in the observed regional radioactivity concentration (so-called partial volume effect or PVE) resulting in systematic errors in estimating quantitative physiologic parameters. The authors have...... in the corresponding ROIs. Reproducibility of the estimated parameters and sensitivity to various error sources were also evaluated. All models tested in the current study yielded PVE-corrected regional CBF values (approximately 0.8 mL x min(-1) x g(-1) for models with a term for gray matter tissue and 0.5 mL x min(-1...... that included two parallel tissue compartments demonstrated better results with regards to the agreement of tissue time-activity curve and the Akaike's Information Criteria. Error sensitivity analysis suggested the model that fits three parameters of the gray matter CBF, the gray matter fraction, and the white...

  2. Analytical Method for Sugar Profile in Pet Food and Animal Feeds by High-Performance Anion-Exchange Chromatography with Pulsed Amperometric Detection.

    Science.gov (United States)

    Ellingson, David J; Anderson, Phillip; Berg, Daniel P

    2016-01-01

    There is a need for a standardized, accurate, rugged, and consistent method to measure for sugars in pet foods and animal feeds. Many traditional standard sugar methods exist for other matrixes, but when applied in collaborative studies there was poor agreement and sources of error identified with those standard methods. The advancement in technology over the years has given us the ability to improve on these standard methods of analysis. A method is described here that addresses these common issues and was subjected to a single-laboratory validation to assess performance on a wide variety of pet foods and animal feeds. Of key importance to the method performance is the sample preparation before extraction, type of extraction solvent, postextraction cleanup, and, finally, optimized chromatography using high-performance anion exchange chromatography with pulsed amperometric detection. The results obtained from the validation demonstrate how typical issues seen with these matrixes can influence performance of sugar analysis. The results also demonstrate that this method is fit-for-purpose and can meet the challenges of sugar analysis in pet food and animal feeds to lay the foundation for a standardized method of analysis.

  3. An Accurate Timing Alignment Method with Time-to-Digital Converter Linearity Calibration for High-Resolution TOF PET.

    Science.gov (United States)

    Li, Hongdi; Wang, Chao; An, Shaohui; Lu, Xingyu; Dong, Yun; Liu, Shitao; Baghaei, Hossain; Zhang, Yuxuan; Ramirez, Rocio; Wong, Wai-Hoi

    2015-06-01

    Accurate PET system timing alignment minimizes the coincidence time window and therefore reduces random events and improves image quality. It is also critical for time-of-flight (TOF) image reconstruction. Here, we use a thin annular cylinder (shell) phantom filled with a radioactive source and located axially and centrally in a PET camera for the timing alignment of a TOF PET system. This timing alignment method involves measuring the time differences between the selected coincidence detector pairs, calibrating the differential and integral nonlinearity of the time-to-digital converter (TDC) with the same raw data and deriving the intrinsic time biases for each detector using an iterative algorithm. The raw time bias for each detector is downloaded to the front-end electronics and the residual fine time bias can be applied during the TOF list-mode reconstruction. Our results showed that a timing alignment accuracy of better than ±25 ps can be achieved, and a preliminary timing resolution of 473 ps (full width at half maximum) was measured in our prototype TOF PET/CT system.

  4. Project Water Science. General Science High School Level.

    Science.gov (United States)

    Water Education Foundation, Sacramento, CA.

    This teacher's guide presents 12 hands-on laboratory activities for high school science classes that cover the environmental issue of water resources in California. The activities are separated into three sections. Five activities in the section on water quality address the topics of groundwater, water hardness, bottled water, water purity, and…

  5. Materials for high performance light water reactors

    Science.gov (United States)

    Ehrlich, K.; Konys, J.; Heikinheimo, L.

    2004-05-01

    A state-of-the-art study was performed to investigate the operational conditions for in-core and out-of-core materials in a high performance light water reactor (HPLWR) and to evaluate the potential of existing structural materials for application in fuel elements, core structures and out-of-core components. In the conventional parts of a HPLWR-plant the approved materials of supercritical fossil power plants (SCFPP) can be used for given temperatures (⩽600 °C) and pressures (≈250 bar). These are either commercial ferritic/martensitic or austenitic stainless steels. Taking the conditions of existing light water reactors (LWR) into account an assessment of potential cladding materials was made, based on existing creep-rupture data, an extensive analysis of the corrosion in conventional steam power plants and available information on material behaviour under irradiation. As a major result it is shown that for an assumed maximum temperature of 650 °C not only Ni-alloys, but also austenitic stainless steels can be used as cladding materials.

  6. Pet Problems at Home: Pet Problems in the Community.

    Science.gov (United States)

    Soltow, Willow

    1984-01-01

    Discusses problems of pets in the community, examining the community's role related to disruptive pets and pet overpopulation. Also discusses pet problems at home, offering advice on selecting a pet, meeting a pet's needs, and disciplining pets. Includes a list of books, films/filmstrips, teaching materials, and various instructional strategies.…

  7. Systematic evaluation of phantom fluids for simultaneous PET/MR hybrid imaging.

    Science.gov (United States)

    Ziegler, Susanne; Braun, Harald; Ritt, Philipp; Hocke, Carsten; Kuwert, Torsten; Quick, Harald H

    2013-08-01

    With the recent advent of integrated PET/MR hybrid systems, the need for simultaneous PET and MR phantom measurements arises. Phantom fluids that are used in stand-alone MR systems, especially in larger phantoms and at a high magnetic field strength, are not necessarily applicable in PET imaging and vice versa. In this study, different approaches to fluid selection were considered and systematically evaluated with respect to their usability for simultaneous PET/MR phantom imaging. Demineralized water, water with increased electrical conductivity, a water-oil emulsion, and monoethylene and triethylene glycol were investigated in MR and PET measurements using the most common PET tracer (18)F-FDG. As an alternative to (18)F-FDG, a modified PET tracer ((18)F-fluoride Kryptofix 222 complex) was investigated toward its ability to dissolve in pure oil, which provides good signal homogeneity in MR imaging. Measurements were performed on a 3.0 T integrated PET/MR whole-body system using a National Electrical Manufacturers Association quality-standard phantom. All tested fluids dissolved the radiotracer (18)F-FDG homogeneously. Regarding their suitability for MR at 3.0 T, all fluids significantly improved the homogeneity compared to pure water (increase of excitation flip angle within the tested phantom by a factor of 2.0). When the use of (18)F-FDG was preferred, triethylene glycol provided the best compromise (flip angle increase by a factor of 1.13). The potential alternative tracer, (18)F-fluoride Kryptofix 222 complex, dissolved in pure oil; however, it is not optimal in its tested composition because it accumulates at the bottom of the phantom during the time of measurement. This study provides a systematic approach toward phantom fluid selection for imaging a given quality-standard body phantom--and phantoms of comparable size--at 3.0 T. For simultaneous PET/MR scans using the standard tracer (18)F-FDG, an alternative fluid to water and oil is proposed that serves as

  8. A water-soluble and highly phosphorescent cyclometallated iridium complex with versatile sensing capability.

    Science.gov (United States)

    Yang, Zhen; Zhao, Yuan; Wang, Chan; Song, Qijun; Pang, Qingfeng

    2017-05-01

    A water-soluble and highly phosphorescent cyclometallated iridium complex [(pq)2Ir(bpy-COOK)](+)Cl(-) (where pq=2-phenylquinoline, bpy-COOK= potassium 2,2'-bipyridine-4,4'-dicarboxylate) (Ir) has been synthesized and characterized. Its phosphorescence can be sensitively and selectively quenched by tryptophan through a photoinduced electron-transfer (PET) process. Furthermore, the phosphorescence of Ir is drastically increased upon binding with bovine serum albumin (BSA), and the enhanced signal is effectively quenched in the presence of Cu(2+). Thus, Ir can be used as a multifunctional chemosensor for tryptophan, BSA, and Cu(2+) determination as well as for cell imaging. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. PET/MR: a paradigm shift

    Science.gov (United States)

    Fürst, Sebastian; Schwaiger, Markus

    2013-01-01

    Abstract More than a decade ago, multimodality imaging was introduced into clinical routine with the development of the positron emission tomography (PET)/computed tomography (CT) technique. Since then, PET/CT has been widely accepted in clinical imaging and has emerged as one of the main cancer imaging modalities. With the recent development of combined PET/magnetic resonance (MR) systems for clinical use, a promising new hybrid imaging modality is now becoming increasingly available. The combination of functional information delivered by PET with the morphologic and functional imaging of MR imaging (e.g., diffusion-weighted imaging, dynamic contrast-enhanced MR imaging and MR spectroscopy) offers exciting possibilities for clinical applications as well as basic research. However, the differences between CT and MR imaging are fundamental. This also leads to distinct differences between PET/CT and PET/MR not only regarding image interpretation but also concerning data acquisition, data processing and image reconstruction. This article provides an overview of the principal differences between PET/CT and PET/MR in terms of scanner design and technology, attenuation correction, speed, acquisition protocols, radiation exposure and safety aspects. PET/MR is expected to show advantages over PET/CT in clinical applications in which MR is known to be superior to CT due to its high intrinsic soft tissue contrast. However, as of now, only assumptions can be made about the future clinical role of PET/MR, as data about the performance of PET/MR in the clinical setting are still limited. The possible future clinical use of PET/MR in oncology, neurology and neurooncology, cardiology and imaging of inflammation is discussed. PMID:23446110

  10. 46 CFR 28.250 - High water alarms.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false High water alarms. 28.250 Section 28.250 Shipping COAST... Individuals On Board, or for Fish Tender Vessels Engaged in the Aleutian Trade § 28.250 High water alarms. On... operating station to indicate high water level in each of the following normally unmanned spaces: (a) A...

  11. Brain PET scan

    Science.gov (United States)

    ... have false results on a PET scan. Blood sugar or insulin levels may affect the test results in people with diabetes . PET scans may be done along with a CT scan. This combination scan is called a PET/CT. Alternative Names Brain positron emission tomography; PET scan - brain References Chernecky ...

  12. High specific radioactivity (1R,2S)-4-[{sup 18}F]fluorometaraminol: a PET radiotracer for mapping sympathetic nerves of the heart

    Energy Technology Data Exchange (ETDEWEB)

    Langer, Oliver; Valette, Heric; Dolle, Frederic E-mail: dolle@dsvidf.cea.fr; Halldin, Christer; Loc' h, Christian; Fuseau, Chantal; Coulon, Christine; Ottaviani, Michele; Bottlaender, Michel; Maziere, Bernard; Crouzel, Christian

    2000-04-01

    The radiolabeled catecholamine analogue (1R,2S)-6-[{sup 18}F]fluorometaraminol (6-[{sup 18}F]FMR) is a substrate for the neuronal norepinephrine transporter. It has been used as a positron emission tomography (PET) ligand to map sympathetic nerves in dog heart. 6-[{sup 18}F]FMR could be only synthesized with low specific radioactivity, which precluded its use in human subjects. We have recently prepared (1R,2S)-4-[{sup 18}F]fluorometaraminol (4-[{sup 18}F]FMR), a new fluoro-analogue of metaraminol, with high specific radioactivity (56-106 GBq/{mu}mol). In the present study, we demonstrate in rats that 4-[{sup 18}F]FMR possesses similar affinity toward myocardial norepinephrine transport mechanisms as 6-[{sup 18}F]FMR. When compared with control animals, an 80% and 76% reduction in myocardial uptake was observed in animals pretreated with desipramine (an inhibitor of the neuronal norepinephrine transporter) and with reserpine (a blocker of the vesicular storage of monoamines), respectively. The entire radioactivity in rat myocardium represented unmetabolized parent tracer as determined by high performance liquid chromatography analysis of tissue extracts. In dogs, myocardial kinetics of 4-[{sup 18}F]FMR were assessed using PET. A rapid and high uptake was observed, followed by prolonged cardiac retention. A heart-to-lung ratio of 15 was reached 10 min after injection of the radiotracer. Pretreatment with desipramine reduced the heart half-life of 4-[{sup 18}F]FMR by 90% compared with control. Moreover, an infusion of tyramine caused a rapid decline of radioactivity in the heart. This demonstrates that 4-[{sup 18}F]FMR specifically visualizes sympathetic neurons in dog heart. High specific radioactivity 4-[{sup 18}F]FMR is a promising alternative to 6-[{sup 18}F]FMR for myocardial neuronal mapping with PET in humans.

  13. Estudo do efeito do envelhecimento sob radiação UV no transporte de água em filmes de PET reciclados de bebidas carbonatadas Study of the UV ageing effect on water transport through PET films recycled from beverage bottles

    Directory of Open Access Journals (Sweden)

    Raquel B. Vichessi

    2008-01-01

    Full Text Available Este trabalho descreve um estudo sobre o efeito do envelhecimento sob radiação UV no transporte de água em filmes planos de PET reciclados de garrafas de bebidas carbonatadas. A partir do formalismo termodinâmico utilizando a relação de Eyring e os resultados de coeficientes de permeabilidade, foram determinadas a entropia e a entalpia de ativação para o transporte da água. Estas funções representadas num gráfico de efeito de compensação termodinâmica permitiram correlacionar a degradação do material, avaliada via espectroscopia na região do infravermelho com transformada de Fourier, com o transporte de água. Foram analisados os possíveis efeitos da presença de estabilizantes, pigmentos e história de processamento.This work describes a study about the UV ageing effect on water transport through PET film sheets recycled from beverage bottles. Using a thermodynamic formalism based on the Eyring relationship and results of water permeability coefficient, it is possible to determine the entropy and enthalpy of activation for the water transport process. These functions were correlated using the compensation thermodynamic plot and correlations were made between the degradation of the PET samples, measured by FTIR, and transport properties. Also, possible effects from the presence of stabilizers, pigments and processing history were analyzed.

  14. PET motion correction using PRESTO with ITK motion estimation

    Energy Technology Data Exchange (ETDEWEB)

    Botelho, Melissa [Institute of Biophysics and Biomedical Engineering, Science Faculty of University of Lisbon (Portugal); Caldeira, Liliana; Scheins, Juergen [Institute of Neuroscience and Medicine (INM-4), Forschungszentrum Jülich (Germany); Matela, Nuno [Institute of Biophysics and Biomedical Engineering, Science Faculty of University of Lisbon (Portugal); Kops, Elena Rota; Shah, N Jon [Institute of Neuroscience and Medicine (INM-4), Forschungszentrum Jülich (Germany)

    2014-07-29

    The Siemens BrainPET scanner is a hybrid MRI/PET system. PET images are prone to motion artefacts which degrade the image quality. Therefore, motion correction is essential. The library PRESTO converts motion-corrected LORs into highly accurate generic projection data [1], providing high-resolution PET images. ITK is an open-source software used for registering multidimensional data []. ITK provides motion estimation necessary to PRESTO.

  15. Development of PET insert for simultaneous PET/MR imaging of human brain

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Jiwoong; Choi, Yong; Jung, Jin Ho; Kim, Sangsu; Im, Ki Chun; Lim, Hyun Keong [Molecular Imaging Research & Education (MiRe) Laboratory, Department of Electronic Engineering, Sogang University, Seoul (Korea, Republic of); Oh, Changheun; Park, HyunWook; Cho, Gyuseong [Departments of Electrical Engineering and Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon (Korea, Republic of)

    2014-07-29

    Recently, there has been great interest on the development of combined PET/MR, which is a useful tool for both functional and anatomic imaging. The purpose of this study was to develop a MR compatible PET insert for simultaneous PET and MR imaging of human brain and to evaluate the performance of the hybrid PET-MRI. The PET insert consisted of 18 detector blocks arranged in a ring of 390 mm diameter with 60 mm axial FOV. Each detector block was composed of 4 × 4 matrix of detector modules, each of which consisted of a 4 × 4 array LYSO coupled to a 4 × 4 GAPD array. The PET gantry was shielded with gold-plated conductive fabric tapes. The charge signals of PET detector transferred via 4 m long flat cables were fed into the position decoder circuits (PDCs) and then transferred to FPGA-embedded DAQ modules. The PDCs and DAQ modules were enclosed in an aluminum box and located at the rear of the MR bore inside MRI room. 3-T human MRIs of two different vendors were used to evaluate the MR compatibility of developed PET insert. No significant changes of the PET performance and the homogeneity of MR images caused by the non-compatibility of PET-MRI were observed with the 2 different MRIs. The signal intensities of MR images were slightly degraded (<3.6%) with the both MRI systems. The difference between independently and simultaneously acquired PET images of brain phantom was negligibly small (<4.3%). High quality simultaneous brain PET and MRI of 3 normal volunteers were successfully acquired. Experimental results indicate that the high performance compact and lightweight PET insert for hybrid PET/MRI, which could be utilized with the MRI from various manufactures, can be developed using GAPD arrays and charge signal transmission method proposed in this study.

  16. Imaging Microglial Activation in Individuals at Clinical High Risk for Psychosis: an In Vivo PET Study with [18F]FEPPA.

    Science.gov (United States)

    Hafizi, Sina; Da Silva, Tania; Gerritsen, Cory; Kiang, Michael; Bagby, R Michael; Prce, Ivana; Wilson, Alan A; Houle, Sylvain; Rusjan, Pablo M; Mizrahi, Romina

    2017-12-01

    Several lines of evidence implicate microglial activation and abnormal immune response in the etiology of psychosis. Previous positron emission tomography (PET) neuroimaging studies of the translocator protein 18 kDa, TSPO, were limited by low affinity of the first-generation radioligand, low-resolution scanners, and small sample sizes. Moreover, there is a dearth of literature on microglial activation in individuals at clinical high risk (CHR) for psychosis. We used a novel second-generation TSPO radioligand, [ 18 F]FEPPA, to examine whether microglial activation is elevated in the dorsolateral prefrontal cortex (DLPFC) and hippocampus of antipsychotic-naive CHR. Twenty-four CHR (antipsychotic-naive n=22) and 23 healthy volunteers (HV) completed a high resolution [ 18 F]FEPPA PET scan and MRI. The PET data were analyzed using the validated two-tissue compartment model with arterial plasma input function with total volume of distribution (V T ) as outcome measure. All analyses were controlled for the TSPO rs6971 polymorphism. We did not observe any significant differences in microglial activation, as indexed by [ 18 F]FEPPA V T , between CHR and HV in either the DLPFC (F (1, 44) =0.41, p=0.52) or the hippocampus (F (1, 44) =2.78, p=0.10). Exploratory associations show that in CHR, [ 18 F]FEPPA V T was positively correlated with apathy (DLPFC: r=0.55, p=0.008; hippocampus: r=0.52, p=0.013) and state anxiety (DLPFC: r=0.60, p=0.003; hippocampus: r=0.48, p=0.024). The lack of significant group differences in [ 18 F]FEPPA V T suggests that microglial activation is not significantly elevated in the clinical high risk state that precedes psychosis.

  17. A novel adaptive discrete cosine transform-domain filter for gap-inpainting of high resolution PET scanners

    Energy Technology Data Exchange (ETDEWEB)

    Shih, Cheng-Ting; Lin, Hsin-Hon; Chuang, Keh-Shih [Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Wu, Jay, E-mail: jwu@mail.cmu.edu.tw [Department of Biomedical Imaging and Radiological Science, China Medical University, Taichung 40402, Taiwan (China); Chang, Shu-Jun [Health Physics Division, Institute of Nuclear Energy Research, Atomic Energy Council, Taoyuan 32546, Taiwan (China)

    2014-08-15

    Purpose: Several positron emission tomography (PET) scanners with special detector block arrangements have been developed in recent years to improve the resolution of PET images. However, the discontinuous detector blocks cause gaps in the sinogram. This study proposes an adaptive discrete cosine transform-based (aDCT) filter for gap-inpainting. Methods: The gap-corrupted sinogram was morphologically closed and subsequently converted to the DCT domain. A certain number of the largest coefficients in the DCT spectrum were identified to determine the low-frequency preservation region. The weighting factors for the remaining coefficients were determined by an exponential weighting function. The aDCT filter was constructed and applied to two digital phantoms and a simulated phantom introduced with various levels of noise. Results: For the Shepp-Logan head phantom, the aDCT filter filled the gaps effectively. For the Jaszczak phantom, no secondary artifacts were induced after aDCT filtering. The percent mean square error and mean structure similarity of the aDCT filter were superior to those of the DCT2 filter at all noise levels. For the simulated striatal dopamine innervation study, the aDCT filter recovered the shape of the striatum and restored the striatum to reference activity ratios to the ideal value. Conclusions: The proposed aDCT filter can recover the missing gap data in the sinogram and improve the image quality and quantitative accuracy of PET images.

  18. A novel adaptive discrete cosine transform-domain filter for gap-inpainting of high resolution PET scanners.

    Science.gov (United States)

    Shih, Cheng-Ting; Wu, Jay; Lin, Hsin-Hon; Chang, Shu-Jun; Chuang, Keh-Shih

    2014-08-01

    Several positron emission tomography (PET) scanners with special detector block arrangements have been developed in recent years to improve the resolution of PET images. However, the discontinuous detector blocks cause gaps in the sinogram. This study proposes an adaptive discrete cosine transform-based (aDCT) filter for gap-inpainting. The gap-corrupted sinogram was morphologically closed and subsequently converted to the DCT domain. A certain number of the largest coefficients in the DCT spectrum were identified to determine the low-frequency preservation region. The weighting factors for the remaining coefficients were determined by an exponential weighting function. The aDCT filter was constructed and applied to two digital phantoms and a simulated phantom introduced with various levels of noise. For the Shepp-Logan head phantom, the aDCT filter filled the gaps effectively. For the Jaszczak phantom, no secondary artifacts were induced after aDCT filtering. The percent mean square error and mean structure similarity of the aDCT filter were superior to those of the DCT2 filter at all noise levels. For the simulated striatal dopamine innervation study, the aDCT filter recovered the shape of the striatum and restored the striatum to reference activity ratios to the ideal value. The proposed aDCT filter can recover the missing gap data in the sinogram and improve the image quality and quantitative accuracy of PET images.

  19. Interfacial behaviour between oil/water systems using ionic surfactants from regional vegetable industry and animal pet

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Francisco Klebson G.; Alves, Juan V.A.; Dantas, Tereza N. Castro; Dutra Junior, Tarcilio V.; Barros Neto, Eduardo L. [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

    2008-07-01

    Interfacial tension (IFT) is one of the most important physical properties in the study of fluid-fluid interfaces. In this research the surfactants - saponified coconut oil, saponified castor oil, saponified soybean oil, saponified sunflower oil and basis soap - were synthesized in laboratory, using carboxylic acids from regional industry and animal fat (bovine fat). This study focuses on the search of a high-efficient, low-cost, and safe for the environment flooding system to be applied in enhanced oil recovery. The principal aim of this work is the obtaining of interfacial tensions between oil/water systems, using the developed ionic surfactants. Results showed that the studied surfactants are able to reduce the IFT between oil and brine. The surfactant that was more effective in reducing the IFT value was the one from animal fat. The composition, as well as the kind of the bond, as saturated or unsaturated, of the surfactants has influence in the IFT value. The ionic surfactants from regional industry and animal fat besides presenting low cost propitiate very low interfacial tensions between oil and brine, favoring the interactions with residual oil and thus increasing oil recovery. (author)

  20. PET studies in dementia

    Energy Technology Data Exchange (ETDEWEB)

    Herholz, K. [Neurologische Universitaetsklinik and Max-Planck-Inst. fuer neurologische Forschung, Koeln (Germany)

    2003-04-01

    Measurement of local cerebral glucose metabolism (lCMRGlc) by positron emission tomography (PET) and {sup 18}F-2-fluoro-2-deoxy-D-glucose (FDG) has become a standard technique during the past 20 years and is now available at many university hospitals in all highly developed countries. Many studies have documented a close relation between lCMRGlc and localized cognitive functions, such as language and visuoconstructive abilities. Alzheimer's disease (AD) is characterized by regional impairment of cerebral glucose metabolism in neocortical association areas (posterior cingulate, temporoparietal and frontal multimodal association cortex), whereas primary visual and sensorimotor cortex, basal ganglia, and cerebellum are relatively well preserved. In a multicenter study comprising 10 PET centers (Network for Efficiency and Standardization of Dementia Diagnosis, NEST-DD) that employed an automated voxel-based analysis of FDG PET images, the distinction between controls and AD patients was 93% sensitive and 93% specific, and even in very mild dementia (at Mini Mental Status Examination (MMSE) 24 or higher) sensitivity was still 84% at 93% specificity. Significantly abnormal metabolism in mild cognitive deficit (MCI) indicates a high risk to develop dementia within the next two years. Reduced neocortical glucose metabolism can probably be detected with FDG PET in AD on average one year before onset of subjective cognitive impairment. In addition to glucose metabolism, specific tracers for dopamine synthesis ({sup 18}F-F-DOPA) and for ({sup 11}C-MP4A) are of interest for differentiation among dementia subtypes. Cortical acetylcholine esterase activity (AChE) activity is significantly lower in patients with AD or with dementia with Lewy bodies (DLB) than in age-matched normal controls. In LBD there is also impairment of dopamine synthesis, similar to Parkinson disease. (author) 115 refs.

  1. Indeterminate findings on oncologic PET/CT: What difference dose PET/MRI make?

    Energy Technology Data Exchange (ETDEWEB)

    Fraum, Tyler J.; Fowler, Kathryn J.; McConathy, Jonathan; Dehdashti, Farokh [Mallinckrodt Institute of Radiology, Washington University School of Medicine, Saint Louis (United States)

    2016-12-15

    Positron emission tomography/computed tomography (PET/CT) with 2-deoxy-2-[{sup 18}F]fluoro-D-glucose (FDG) has become the standard of care for the initial staging and subsequent treatment response assessment of many different malignancies. Despite this success, PET/CT is often supplemented by MRI to improve assessment of local tumor invasion and to facilitate detection of lesions in organs with high background FDG uptake. Consequently, PET/MRI has the potential to expand the clinical value of PET examinations by increasing reader certainty and reducing the need for subsequent imaging. This study evaluates the ability of FDG-PET/MRI to clarify findings initially deemed indeterminate on clinical FDG-PET/CT studies. A total of 190 oncology patients underwent whole-body PET/CT, immediately followed by PET/MRI utilizing the same FDG administration. Each PET/CT was interpreted by our institution's nuclear medicine service as a standard-of-care clinical examination. Review of these PET/CT reports identified 31 patients (16 %) with indeterminate findings. Two readers evaluated all 31 PET/CT studies, followed by the corresponding PET/MRI studies. A consensus was reached for each case, and changes in interpretation directly resulting from PET/MRI review were recorded. Interpretations were then correlated with follow-up imaging, pathology results, and other diagnostic studies. In 18 of 31 cases with indeterminate findings on PET/CT, PET/MRI resulted in a more definitive interpretation by facilitating the differentiation of infection/inflammation from malignancy (15/18), the accurate localization of FDG-avid lesions (2/18), and the characterization of incidental non-FDG-avid solid organ lesions (1/18). Explanations for improved reader certainty with PET/MRI included the superior soft tissue contrast of MRI and the ability to assess cellular density with diffusion-weighted imaging. The majority (12/18) of such cases had an appropriate standard of reference; in all 12 cases

  2. Evaluation of the PET component of simultaneous [{sup 18}F]choline PET/MRI in prostate cancer: comparison with [{sup 18}F]choline PET/CT

    Energy Technology Data Exchange (ETDEWEB)

    Wetter, Axel; Lipponer, Christine; Nensa, Felix; Altenbernd, Jens-Christian; Schlosser, Thomas; Lauenstein, Thomas [University Hospital Essen, Department of diagnostic and interventional Radiology and Neuroradiology, Essen (Germany); Heusch, Philipp [University Dusseldorf, Medical Faculty, Department of diagnostic and interventional Radiology, Dusseldorf (Germany); Ruebben, Herbert [University Hospital Essen, Department of Urology and pediatric Urology, Essen (Germany); Bockisch, Andreas; Poeppel, Thorsten; Nagarajah, James [University Hospital Essen, Department of Nuclear Medicine, Essen (Germany)

    2014-01-15

    The aim of this study was to evaluate the positron emission tomography (PET) component of [{sup 18}F]choline PET/MRI and compare it with the PET component of [{sup 18}F]choline PET/CT in patients with histologically proven prostate cancer and suspected recurrent prostate cancer. Thirty-six patients were examined with simultaneous [{sup 18}F]choline PET/MRI following combined [{sup 18}F]choline PET/CT. Fifty-eight PET-positive lesions in PET/CT and PET/MRI were evaluated by measuring the maximum and mean standardized uptake values (SUV{sub max} and SUV{sub mean}) using volume of interest (VOI) analysis. A scoring system was applied to determine the quality of the PET images of both PET/CT and PET/MRI. Agreement between PET/CT and PET/MRI regarding SUV{sub max} and SUV{sub mean} was tested using Pearson's product-moment correlation and Bland-Altman analysis. All PET-positive lesions that were visible on PET/CT were also detectable on PET/MRI. The quality of the PET images was comparable in both groups. Median SUV{sub max} and SUV{sub mean} of all lesions were significantly lower in PET/MRI than in PET/CT (5.2 vs 6.1, p < 0.05 and 2.0 vs 2.6, p < 0.001, respectively). Pearson's product-moment correlation indicated highly significant correlations between SUV{sub max} of PET/CT and PET/MRI (R = 0.86, p < 0.001) as well as between SUV{sub mean} of PET/CT and PET/MRI (R = 0.81, p < 0.001). Bland-Altman analysis revealed lower and upper limits of agreement of -2.77 to 3.64 between SUV{sub max} of PET/CT vs PET/MRI and -1.12 to +2.23 between SUV{sub mean} of PET/CT vs PET/MRI. PET image quality of PET/MRI was comparable to that of PET/CT. A highly significant correlation between SUV{sub max} and SUV{sub mean} was found. Both SUV{sub max} and SUV{sub mean} were significantly lower in [{sup 18}F]choline PET/MRI than in [{sup 18}F]choline PET/CT. Differences of SUV{sub max} and SUV{sub mean} might be caused by different techniques of attenuation correction

  3. Semiquantitative Assessment of (18)F-FDG Uptake in the Normal Skeleton: Comparison Between PET/CT and Time-of-Flight Simultaneous PET/MRI.

    Science.gov (United States)

    Minamimoto, Ryogo; Xu, Guofan; Jamali, Mehran; Holley, Dawn; Barkhodari, Amir; Zaharchuk, Greg; Iagaru, Andrei

    2017-11-01

    Differences in the attenuation correction methods used in PET/CT scanners versus the newly introduced whole-body simultaneous PET/MRI reportedly result in differences in standardized uptake values (SUVs) in the normal skeleton. The aim of the study was to compare the semiquantitative FDG uptake in the normal skeleton using time-of-flight (TOF) PET/MRI versus PET/CT with and without TOF. Participants received a single FDG injection and underwent non-TOF and TOF PET/CT (n = 23) or non-TOF PET/CT and TOF PET/MRI (n = 50). Mean SUV (SUVmean) and maximum SUV (SUVmax) were measured from all PET scans for nine normal regions of the skeleton. Pearson correlation coefficients (r) were used to evaluate the SUVmax and SUVmean of normal skeleton between non-TOF and TOF PET/CT, as well as between non-TOF PET/CT and TOF PET/MRI. In addition, percentage differences in SUVmax and SUVmean of the normal skeleton between non-TOF and TOF PET/CT and between non-TOF PET/CT and TOF PET/MRI were evaluated. The SUVmax and SUVmean in the normal skeleton significantly increased between non-TOF and TOF PET/CT, but they significantly decreased between non-TOF PET/CT and TOF PET/MRI. The SUVmax and SUVmean in normal skeleton showed good correlation between non-TOF PET/CT and TOF PET/MRI (SUVmax, r = 0.88; SUVmean, r = 0.91) and showed a similar trend between non-TOF and TOF PET/CT (SUVmax, r = 0.88; SUVmean, r = 0.94). In the normal skeleton, SUVmax and SUVmean showed high correlations between PET/MRI and PET/CT. The MRI attenuation correction used in TOF PET/MRI provides reliable semiquantitative measurements in the normal skeleton.

  4. Imaging with {sup 124}I in differentiated thyroid carcinoma: is PET/MRI superior to PET/CT?

    Energy Technology Data Exchange (ETDEWEB)

    Binse, I.; Poeppel, T.D.; Ruhlmann, M.; Gomez, B.; Bockisch, A.; Rosenbaum-Krumme, S.J. [University of Duisburg-Essen, Medical Faculty, Department of Nuclear Medicine, Essen (Germany); Umutlu, L. [University of Duisburg-Essen, Medical Faculty, Department of Radiology, Essen (Germany)

    2016-06-15

    The aim of this study was to compare integrated PET/CT and PET/MRI for their usefulness in detecting and categorizing cervical iodine-positive lesions in patients with differentiated thyroid cancer using {sup 124}I as tracer. The study group comprised 65 patients at high risk of iodine-positive metastasis who underwent PET/CT (low-dose CT scan, PET acquisition time 2 min; PET/CT{sub 2}) followed by PET/MRI of the neck 24 h after {sup 124}I administration. PET images from both modalities were analysed for the numbers of tracer-positive lesions. Two different acquisition times were used for the comparisons, one matching the PET/CT{sub 2} acquisition time (2 min, PET/MRI{sub 2}) and the other covering the whole MRI scan time (30 min, PET/MRI{sub 30}). Iodine-positive lesions were categorized as metastasis, thyroid remnant or inconclusive according to their location on the PET/CT images. Morphological information provided by MRI was considered for evaluation of lesions on PET/MRI and for volume information. PET/MRI{sub 2} detected significantly more iodine-positive metastases and thyroid remnants than PET/CT{sub 2} (72 vs. 60, p = 0.002, and 100 vs. 80, p = 0.001, respectively), but the numbers of patients with at least one tumour lesion identified were not significantly different (21/65 vs. 17/65 patients). PET/MRI{sub 30} tended to detect more PET-positive metastases than PET/MRI{sub 2} (88 vs. 72), but the difference was not significant (p = 0.07). Of 21 lesions classified as inconclusive on PET/CT, 5 were assigned to metastasis or thyroid remnant when evaluated by PET/MRI. Volume information was available in 34 % of iodine-positive metastases and 2 % of thyroid remnants on PET/MRI. PET/MRI of the neck was found to be superior to PET/CT in detecting iodine-positive lesions. This was attributed to the higher sensitivity of the PET component, Although helpful in some cases, we found no substantial advantage of PET/MRI over PET/CT in categorizing iodine

  5. Gamma-camera 18F-FDG PET in diagnosis and staging of patients presenting with suspected lung cancer and comparison with dedicated PET

    DEFF Research Database (Denmark)

    Oturai, Peter S; Mortensen, Jann; Enevoldsen, Henriette

    2004-01-01

    It is not clear whether high-quality coincidence gamma-PET (gPET) cameras can provide clinical data comparable with data obtained with dedicated PET (dPET) cameras in the primary diagnostic work-up of patients with suspected lung cancer. This study focuses on 2 main issues: direct comparison betw...

  6. Disaster Preparedness for Your Pet

    Science.gov (United States)

    ... for pets Louisiana State University College of Veterinary Medicine: Manual for Animal Shelters during a Disaster Ready Wrigley Pet Stories After the Storm: Pets and Preparedness Pet Preparedness Features Media Sign up for Features ...

  7. Imaging-based biomarkers of cognitive performance in older adults constructed via high-dimensional pattern regression applied to MRI and PET.

    Directory of Open Access Journals (Sweden)

    Ying Wang

    Full Text Available In this study, we used high-dimensional pattern regression methods based on structural (gray and white matter; GM and WM and functional (positron emission tomography of regional cerebral blood flow; PET brain data to identify cross-sectional imaging biomarkers of cognitive performance in cognitively normal older adults from the Baltimore Longitudinal Study of Aging (BLSA. We focused on specific components of executive and memory domains known to decline with aging, including manipulation, semantic retrieval, long-term memory (LTM, and short-term memory (STM. For each imaging modality, brain regions associated with each cognitive domain were generated by adaptive regional clustering. A relevance vector machine was adopted to model the nonlinear continuous relationship between brain regions and cognitive performance, with cross-validation to select the most informative brain regions (using recursive feature elimination as imaging biomarkers and optimize model parameters. Predicted cognitive scores using our regression algorithm based on the resulting brain regions correlated well with actual performance. Also, regression models obtained using combined GM, WM, and PET imaging modalities outperformed models based on single modalities. Imaging biomarkers related to memory performance included the orbito-frontal and medial temporal cortical regions with LTM showing stronger correlation with the temporal lobe than STM. Brain regions predicting executive performance included orbito-frontal, and occipito-temporal areas. The PET modality had higher contribution to most cognitive domains except manipulation, which had higher WM contribution from the superior longitudinal fasciculus and the genu of the corpus callosum. These findings based on machine-learning methods demonstrate the importance of combining structural and functional imaging data in understanding complex cognitive mechanisms and also their potential usage as biomarkers that predict cognitive

  8. Evaluation of diagnostic performance of whole-body simultaneous PET/MRI in pediatric lymphoma.

    Science.gov (United States)

    Ponisio, Maria Rosana; McConathy, Jonathan; Laforest, Richard; Khanna, Geetika

    2016-08-01

    Whole-body (18)F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) is the standard of care for lymphoma. Simultaneous PET/MRI (magnetic resonance imaging) is a promising new modality that combines the metabolic information of PET with superior soft-tissue resolution and functional imaging capabilities of MRI while decreasing radiation dose. There is limited information on the clinical performance of PET/MRI in the pediatric setting. This study evaluated the feasibility, dosimetry, and qualitative and quantitative diagnostic performance of simultaneous whole-body FDG-PET/MRI in children with lymphoma compared to PET/CT. Children with lymphoma undergoing standard of care FDG-PET/CT were prospectively recruited for PET/MRI performed immediately after the PET/CT. Images were evaluated for quality, lesion detection and anatomical localization of FDG uptake. Maximum and mean standardized uptake values (SUVmax/mean) of normal organs and SUVmax of the most FDG-avid lesions were measured for PET/MRI and PET/CT. Estimation of radiation exposure was calculated using specific age-related factors. Nine PET/MRI scans were performed in eight patients (mean age: 15.3 years). The mean time interval between PET/CT and PET/MRI was 51 ± 10 min. Both the PET/CT and PET/MRI exams had good image quality and alignment with complete (9/9) concordance in response assessment. The SUVs from PET/MRI and PET/CT were highly correlated for normal organs (SUVmean r(2): 0.88, Pcompared with PET/CT. Simultaneous whole-body PET/MRI is clinically feasible in pediatric lymphoma. PET/MRI performance is comparable to PET/CT for lesion detection and SUV measurements. Replacement of PET/CT with PET/MRI can significantly decrease radiation dose from diagnostic imaging in children.

  9. A micro-plate colorimetric assay for rapid determination of trace zinc in animal feed, pet food and drinking water by ion masking and statistical partitioning correction.

    Science.gov (United States)

    Wang, Jiayi; Niu, Yiming; Zhang, Chi; Chen, Yiqiang

    2018-04-15

    A new micro-plate colorimetric assay was developed for rapid determination of zinc in animal feed, pet food and drinking water. Zinc ion was extracted from sample by trichloroacetic acid and then reacted with 2-(5-Bromo-2-pyridylazo)-5-[N-propyl-N-(3-sulfopropyl)amino]phenol (5-Br-PAPS) to form a Zn-PAPS complex to be detected by a micro-plate reader at 552 nm. An ion masking formula including salicylaldoxime, deferoxamine and sodium citrate were screened and applied to exclude the interference from other heavy metals and a partitioning correction approach was proposed to eliminate the matrix effect derived from feed sample. The entire procedure can be completed within 40 min and the detection range was 0.038-8.0 μg mL-1 zinc in buffer solution. Moreover, the analysis in real samples revealed the consistency of results by this assay and those by atomic absorption spectrometry analysis. These features highlighted the possibility for this proposed assay to be used for rapid determination of zinc in complex samples. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Electroacupuncture Treatment Improves Learning-Memory Ability and Brain Glucose Metabolism in a Mouse Model of Alzheimer’s Disease: Using Morris Water Maze and Micro-PET

    Directory of Open Access Journals (Sweden)

    Jing Jiang

    2015-01-01

    Full Text Available Introduction. Alzheimer’s disease (AD causes progressive hippocampus dysfunctions leading to the impairment of learning and memory ability and low level of uptake rate of glucose in hippocampus. What is more, there is no effective treatment for AD. In this study, we evaluated the beneficial and protective effects of electroacupuncture in senescence-accelerated mouse prone 8 (SAMP8. Method. In the electroacupuncture paradigm, electroacupuncture treatment was performed once a day for 15 days on 7.5-month-old SAMP8 male mice. In the normal control paradigm and AD control group, 7.5-month-old SAMR1 male mice and SAMP8 male mice were grabbed and bandaged while electroacupuncture group therapy, in order to ensure the same treatment conditions, once a day, 15 days. Results. From the Morris water maze (MWM test, we found that the treatment of electroacupuncture can improve the spatial learning and memory ability of SAMP8 mouse, and from the micro-PET test, we proved that after the electroacupuncture treatment the level of uptake rate of glucose in hippocampus was higher than normal control group. Conclusion. These results suggest that the treatment of electroacupuncture may provide a viable treatment option for AD.

  11. Reproducibility of 18F-FDG PET uptake measurements in head and neck squamous cell carcinoma on both PET/CT and PET/MR

    Science.gov (United States)

    Fischer, B M; Aznar, M C; Hansen, A E; Vogelius, I R; Löfgren, J; Andersen, F L; Loft, A; Kjaer, A; Højgaard, L; Specht, L

    2015-01-01

    Objective: To investigate reproducibility of fluorine-18 fludeoxyglucose (18F-FDG) uptake on 18F-FDG positron emission tomography (PET)/CT and 18F-FDG PET/MR scans in patients with head and neck squamous cell carcinoma (HNSCC). Methods: 30 patients with HNSCC were included in this prospective study. The patients were scanned twice before radiotherapy treatment with both PET/CT and PET/MR. Patients were scanned on the same scanners, 3 days apart and according to the same protocol. Metabolic tumour activity was measured by the maximum and peak standardized uptake value (SUVmax and SUVpeak, respectively), and total lesion glycolysis from the metabolic tumour volume defined from ≥50% SUVmax. Bland–Altman analysis with limits of agreement, coefficient of variation (CV) from the two modalities were performed in order to test the reproducibility. Furthermore, CVs from SUVmax and SUVpeak were compared. The area under the curve from cumulative SUV–volume histograms were measured and tested for reproducibility of the distribution of 18F-FDG uptake. Results: 24 patients had two pre-treatment PET/CT scans and 21 patients had two pre-treatment PET/MR scans available for further analyses. Mean difference for SUVmax, peak and mean was approximately 4% for PET/CT and 3% for PET/MR, with 95% limits of agreement less than ±20%. CV was small (5–7%) for both modalities. There was no significant difference in CVs between PET/CT and PET/MR (p = 0.31). SUVmax was not more reproducible than SUVpeak (p = 0.09). Conclusion: 18F-FDG uptake in PET/CT and PET/MR is highly reproducible and we found no difference in reproducibility between PET/CT and PET/MR. Advances in knowledge: This is the first report to test reproducibility of PET/CT and PET/MR. PMID:25634069

  12. CNS metabolism in high-risk drug abuse, German version. Insights gained from {sup 1}H- and {sup 31}P MRS and PET; ZNS-Stoffwechsel bei Missbrauch von Hochrisikodrogen. Erkenntnisse durch {sup 1}H- und {sup 31}P-MRS sowie PET

    Energy Technology Data Exchange (ETDEWEB)

    Bodea, S.V. [Klinik fuer Diagnostische und Interventionelle Neuroradiologie, Universitaetsklinikum des Saarlandes, Homburg/Saar (Germany)

    2017-06-15

    High-risk drug consumption is a considerable problem for public health actors in industrialised countries. The latest trends show a market tendency towards diversification and increasing demand for high-purity synthetic drugs. Whilst most consumers seek medical help after cannabis use, it is high-risk drugs like cocaine, heroin and amphetamines that account for most of the 1000 drug-related deaths that occur in Germany every year. This article presents the most prominent in vivo cerebral metabolic information in cocaine, heroin and methamphetamine users provided by MRI spectroscopy and PET imaging. We reviewed the literature reporting neuroimaging studies of in vivo metabolic data for methamphetamine, cocaine and heroin consumption published up to March 2017. The search was conducted using PubMed with the following key words: methamphetamine, cocaine, heroin, MR spectroscopy, PET. MRI and PET are indispensable tools in gauging brain metabolic response to illegal drug abuse. Future breakthroughs in this field will most likely come from the investigation of novel neurotransmitter systems in PET and imaging phosphorus and carbon metabolites in MRI. (orig.) [German] In den Industrielaendern ist der Konsum von Hochrisikodrogen ein erhebliches Problem fuer das gesamte Gesundheitssystem. Neueste Entwicklungen zeigen eine Tendenz zu immer groesserer Diversifikation und eine erhoehte Nachfrage nach synthetischen Drogen von hohem Reinheitsgrad. Waehrend die meisten Konsumenten medizinische Hilfe nach Cannabisverbrauch suchen, sind es die Hochrisikodrogen wie Heroin, Kokain und Amphetamine, an denen die meisten der 1000 Drogentoten pro Jahr in Deutschland sterben. In diesem Artikel werden die auffaelligsten, mithilfe der Magnetresonanzspektroskopie (MRS) und Positronenemissionstomographie (PET) erfassten In-vivo-Daten zum Hirnstoffwechsel bei Konsumenten von Kokain, Heroin und Methamphetaminen vorgestellt. Die Literatur ueber den zerebralen Energiestoffwechsel bei

  13. Simultaneous trimodal PET-MR-EEG imaging: Do EEG caps generate artefacts in PET images?

    OpenAIRE

    Ravichandran Rajkumar; Elena Rota Kops; Jörg Mauler; Lutz Tellmann; Christoph Lerche; Hans Herzog; N Jon Shah; Irene Neuner

    2017-01-01

    Trimodal simultaneous acquisition of positron emission tomography (PET), magnetic resonance imaging (MRI), and electroencephalography (EEG) has become feasible due to the development of hybrid PET-MR scanners. To capture the temporal dynamics of neuronal activation on a millisecond-by-millisecond basis, an EEG system is appended to the quantitative high resolution PET-MR imaging modality already established in our institute. One of the major difficulties associated with the development of sim...

  14. Design Features and Mutual Compatibility Studies of the Time-of-Flight PET Capable GE SIGNA PET/MR System.

    Science.gov (United States)

    Levin, Craig S; Maramraju, Sri Harsha; Khalighi, Mohammad Mehdi; Deller, Timothy W; Delso, Gaspar; Jansen, Floris

    2016-08-01

    A recent entry into the rapidly evolving field of integrated PET/MR scanners is presented in this paper: a whole body hybrid PET/MR system (SIGNA PET/MR, GE Healthcare) capable of simultaneous acquisition of both time-of-flight (TOF) PET and high resolution MR data. The PET ring was integrated into an existing 3T MR system resulting in a (patient) bore opening of 60 cm diameter, with a 25 cm axial FOV. PET performance was evaluated both on the standalone PET ring and on the same detector integrated into the MR system, to assess the level of mutual interference between both subsystems. In both configurations we obtained detector performance data. PET detector performance was not significantly affected by integration into the MR system. The global energy resolution was within 2% (10.3% versus 10.5%), and the system coincidence time resolution showed a maximum change of < 3% (385 ps versus 394 ps) when measured outside MR and during simultaneous PET/MRI acquisitions, respectively. To evaluate PET image quality and resolution, the NEMA IQ phantom was acquired with MR idle and with MR active. Impact of PET on MR IQ was assessed by comparing SNR with PET acquisition on and off. B0 and B1 homogeneities were acquired before and after the integration of the PET ring inside the magnet. In vivo brain and whole body head-to-thighs data were acquired to demonstrate clinical image quality.

  15. High-resolution Time-Of-Flight PET with Depth-Of-Interaction becomes feasible: a proof of principle

    CERN Document Server

    Cosentino, Luigi; Pappalardo, Alfio; Garibaldi, Franco

    2012-01-01

    In this paper we prove that the choice of a suitable treatment of the scintillator surfaces, along with suitable photodetectors electronics and specific algorithms for raw data analysis, allow to achieve an optimal tradeoff between energy, time and DOI resolution, thus strongly supporting the feasibility of a prostate TOF- PET probe, MRI compatible, with the required features and performance. In numbers this means a detector element of 1.5mm x 1.5mm x 10mm, achieving at the same time energy resolution around 11.5%, time-of- flight resolution around 150 ps and DOI resolution even below 1 mm. We stress that such a time resolution allows to increase significantly the Noise Equivalent Counting Rate, and consequently improve the image quality and the lesion detection capability. These individual values correspond to the best obtained so far by other groups, but we got all of them simultaneously. In our opinion this proof of principle paves the way to the feasibility of a TOF-PET MRI compatible probe with unprecede...

  16. Evaluation of optimal water fluoridation on the incidence and skeletal distribution of naturally arising osteosarcoma in pet dogs.

    Science.gov (United States)

    Rebhun, R B; Kass, P H; Kent, M S; Watson, K D; Withers, S S; Culp, W T N; King, A M

    2017-06-01

    Experimental toxicological studies in laboratory animals and epidemiological human studies have reported a possible association between water fluoridation and osteosarcoma (OSA). To further explore this possibility, a case-control study of individual dogs evaluated by the UC Davis Veterinary Medical Teaching Hospital was conducted using ecologic data on water fluoridation based on the owner's residence. The case group included 161 dogs with OSA diagnosed between 2008-2012. Two cancer control groups included dogs diagnosed with lymphoma (LSA) or hemangiosarcoma (HSA) during the same period (n = 134 and n = 145, respectively). Dogs with OSA were not significantly more likely to live in an area with optimized fluoride in the water than dogs with LSA or HSA. Additional analyses within OSA patients also revealed no significant differences in age, or skeletal distribution of OSA cases relative to fluoride status. Taken together, these analyses do not support the hypothesis that optimal fluoridation of drinking water contributes to naturally occurring OSA in dogs. © 2016 John Wiley & Sons Ltd.

  17. Highly energetic phenomena in water electrolysis

    OpenAIRE

    Postnikov, A. V.; Uvarov, I. V.; Lokhanin, M. V.; V. B. Svetovoy

    2016-01-01

    Water electrolysis performed in microsystems with a fast change of voltage polarity produces optically invisible nanobubbles containing H2 and O2 gases. In this form the gases are able to the reverse reaction of water formation. Here we report extreme phenomena observed in a millimeter-sized open system. Under a frequency of driving pulses above 100 kHz the process is accompanied by clicking sounds repeated every 50 ms or so. Fast video reveals that synchronously with the click a bubble is gr...

  18. Highly efficient one-pot labeling of new phosphonium cations with fluorine-18 as potential PET agents for myocardial perfusion imaging.

    Science.gov (United States)

    Zhao, Zuoquan; Yu, Qian; Mou, Tiantian; Liu, Chang; Yang, Wenjiang; Fang, Wei; Peng, Cheng; Lu, Jie; Liu, Yu; Zhang, Xianzhong

    2014-11-03

    Lipophilic cations such as phosphonium salts can accumulate in mitochondria of heart in response to the negative inner-transmembrane potentials. Two phosphonium salts [(18)F]FMBTP and [(18)F]mFMBTP were prepared and evaluated as potential myocardial perfusion imaging (MPI) agents in this study. The cations were radiolabeled via a simplified one-pot method starting from [(18)F]fluoride and followed by physicochemical property tests, in vitro cellular uptake assay, ex vivo mouse biodistribution, and in vivo rat microPET imaging. The total radiosynthesis time was less than 60 min including HPLC purification. The [(18)F] labeled compounds were obtained in high radiolabeling yield (∼50%) and good radiochemical purity (>99%). Both compounds were electropositive, and their log P values at pH 7.4 were 1.16 ± 0.003 (n = 3) and 1.05 ± 0.01 (n = 3), respectively. Both [(18)F]FMBTP and [(18)F]mFMBTP had high heart uptake (25.24 ± 2.97% ID/g and 31.02 ± 0.33% ID/g at 5 min postinjection (p.i.)) in mice with good retention (28.99 ± 3.54% ID/g and 26.82 ± 3.46% ID/g at 120 min p.i.). From the PET images in rats, the cations exhibited high myocardium uptake and fast clearance from liver and small intestine to give high-contrast images across all time points. These phosphonium cations were radiosynthesized via a highly efficient one-pot procedure for potential MPI offering high heart accumulation and rapid nontarget clearance.

  19. Heart PET scan

    Science.gov (United States)

    ... nuclear medicine scan; Heart positron emission tomography; Myocardial PET scan ... A PET scan requires a small amount of radioactive material (tracer). This tracer is given through a vein (IV), ...

  20. Pets and Parasites

    Science.gov (United States)

    ... oral contact with your pet. Don’t share food or kiss your pet on the mouth. Pregnant women and people who have weakened immune systems should never clean out cat litter boxes or handle cat feces. They can ...

  1. Are high-water-content contact lenses safe?

    Science.gov (United States)

    Bhatia, R P; Panday, Kshama; Srivastava, Rashmi; Indolia, Hitendra Singh

    2006-01-01

    We examined the role of tear secretion on contact lens water content during selection. Tear secretion was estimated using Schirmer's tests. High-water-content contact lenses compromised the tear film more than low-water-content contact lenses, hence they should not be advised in low or marginal Schirmer's test cases.

  2. A tyrosine kinase inhibitor-based high-affinity PET radiopharmaceutical targets vascular endothelial growth factor receptor.

    Science.gov (United States)

    Li, Feng; Jiang, Sheng; Zu, Youli; Lee, Daniel Y; Li, Zheng

    2014-09-01

    Tyrosine kinase receptors including vascular endothelial growth factor receptor (VEGFR) have gained significant attention as pharmacologic targets. However, clinical evaluation of small-molecule drugs or biologics that target these pathways has so far yielded mixed results in a variety of solid tumors. The reasons for response variability remain unknown, including the temporal and spatial patterns of receptor tyrosine kinase expression. Methods to detect and quantify the presence of such cellular receptors would greatly facilitate drug development and therapy response assessment. We aimed to generate specific imaging agents as potential companion diagnostics that could also be used for targeted radionuclide therapy. Here, we report on the synthesis and initial preclinical performance of (64)Cu-labeled probes that were based on the kinase inhibitor already in clinical use, vandetanib (ZD6474), as a VEGFR-selective theranostic radiopharmaceutical. A monomeric (ZD-G1) and a dimeric (ZD-G2) derivative of ZD6474 were synthesized and conjugated with DOTA for chelation with (64)Cu to produce the probes (64)Cu-DOTA-ZD-G1 and (64)Cu-DOTA-ZD-G2. The binding affinity and specificity to VEGFR were measured using U-87 MG cells known to overexpress VEGFR. Small-animal PET and biodistribution studies were performed with (64)Cu-labeled probes (3-4 MBq) intravenously administered in U-87 MG tumor-bearing mice with or without coinjection of unlabeled ZD-G2 for up to 24 h after injection. Receptor-binding assays yielded a mean equilibrium dissociation constant of 44.7 and 0.45 nM for monomeric and dimeric forms, respectively, indicating a synergistic effect in VEGFR affinity by multivalency. Small-animal PET/CT imaging showed rapid tumor accumulation of (64)Cu-DOTA-ZD-G2, with excellent tumor-to-normal tissue contrast by 24 h. Coinjection of the (64)Cu-DOTA-ZD-G2 with 50 nmol (60 μg) of nonradioactive ZD-G2 effectively blocked tumor uptake. A (64)Cu-labeled probe derived from an

  3. WE-EF-303-01: FEATURED PRESENTATION: Hydrogel Fiducial Markers for In-Vivo Proton Therapy and Range Verifications Using PET

    Energy Technology Data Exchange (ETDEWEB)

    Cho, J; Cho, S [UT MD Anderson Cancer Center, Houston, TX (United States); Campbell, P [Augmenix, Inc., Waltham, MA (United States); Wang, M; Zubarev, E [Rice University, Houston, TX - Texas (United States); Alqathami, M; Mawlawi, O [MD Anderson Cancer Ctr., Houston, TX (United States); Li, H [M.D. Anderson Cancer Center, Houston, TX (United States); Sahoo, N [MD Anderson Cancer Center, Houston, TX (United States); Kerr, M [UT MD Anderson Cancer Center, Houston, TX (TX) (United States)

    2015-06-15

    Purpose: Currently there are no clinically used techniques for in-vivo proton treatment/range verification. Our aim was to develop patient implantable markers that can be visualized in CT/x-ray for treatment-planning/beam-positioning, and also in PET for proton treatment/range verification. Methods: Biocompatible/biodegradable hydrogel polymers were immersed in O18-enriched water and O16 water, respectively to create O18-water hydrogels (0.5 cm3) and O16-water hydrogels (1 cm3) (both >99% water and <1% polymer). Also, 5–8 µm Zn powder was suspended in O16 water and O18-enriched water and cross-linked with hydrogel polymers to create Zn/16O-water hydrogels (30%/70% mass ratio, <1% polymer) and Zn/18O-water hydrogels (10%/90%). A block of extra-firm “wet” tofu (12.3×8.8×4.9 cm, ρ{sup =}1) immersed in water was injected with Zn/O16-water hydrogels (0.9 cm3 each) at four different depths using an 18 gauge needle. Similarly, Zn/18O-water hydrogels (0.9 cm3) were injected in a different tofu phantom. As a reference, both 16O-water and O18-water hydrogels in petri-dishes were irradiated in a “dry” environment. The hydrogels in the “wet” tofu phantoms and “dry” petri-dishes were CT-scanned and treatment-planned. Then, they were positioned at the proton distal dose fall-off region and irradiated (2 Gy) followed by PET/CT imaging. Results: Significantly high PET signals were observed only at O18-water hydrogels in the “dry” environment. Zn/O16-water hydrogels injected in the tofu phantom showed outstanding CT visibility but provided no noticeable PET signals. Zn/O18-water hydrogels in the “wet” tofu showed excellent CT visibility and moderate PET visibility, however, weaker PET signals than the “dry” environment possibly due to O18-water leaching out. Conclusion: The developed hydrogel markers can be used as universal fiducial markers due to their CT/PET/MRI/US visibility. Their PET visibility (possibly contributed more by activated O18

  4. Limitations of FDG-PET and FDG-PET with computed tomography for detecting synchronous cancer in pharyngeal cancer.

    Science.gov (United States)

    Suzuki, Hidenori; Hasegawa, Yasuhisa; Terada, Akihiro; Ogawa, Tetsuya; Hyodo, Ikuo; Suzuki, Masahiro; Nakashima, Tsutomu; Tamaki, Tsuneo; Nishio, Masami

    2008-11-01

    To analyze the ability of fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) and the fusion of FDG-PET with computed tomography (FDG-PET/CT) to detect synchronous upper gastrointestinal tract (UGI) cancer in newly diagnosed pharyngeal squamous cell carcinoma (SCC). Synchronous UGI cancer is a significant problem in treating pharyngeal SCC, particularly for Japanese populations reported to be at high risk. Good results have been reported from the use of FDG-PET and FDG-PET/CT in staging head and neck SCC (HNSCC). An additional advantage is that both techniques are expected to prove useful in detecting synchronous cancer. Retrospective analysis of medical records. Aichi Cancer Center, Nagoya, Japan. Forty-three Japanese patients with pharyngeal SCC were assessed for the ability of FDG-PET and FDG-PET/CT to detect synchronous UGI cancer via a comparison with UGI Lugol chromoendoscopy. The patients had undergone 17 FDG-PET and 26 FDG-PET/CT scans before treatment. Sensitivity of FDG-PET and FDG-PET/CT to detect synchronous UGI cancer. Pathologically, 6 patients with esophageal SCC (14%) and 4 with stomach adenocarcinoma (9%) were diagnosed on the basis of suspect lesions detected by UGI Lugol chromoendoscopy. One patient was found to have stage T2 esophageal cancer by FDG-PET/CT, but no patients had UGI cancer. The sensitivity of detecting T1 UGI cancer by FDG-PET and FDG-PET/CT was 0%. The choice of diagnostic technique must be based on the site and histologic characteristics of the synchronous tumor. Although FDG-PET and FDG-PET/CT are still the preferred techniques for staging HNSCC, neither replaces Lugol chromoendoscopy for detecting synchronous UGI cancer in high-risk populations.

  5. Healthy Pets and People

    Science.gov (United States)

    ... Your Pet Healthy Whether you have a dog, cat, horse, parakeet, gerbil, or bearded dragon, providing regular, life-long veterinary care is important to having a healthy pet and a healthy family. Regular veterinary visits are essential to good pet health. Talk to your pet’s veterinarian about ...

  6. Identifying and preserving high-water mark data

    Science.gov (United States)

    Koenig, Todd A.; Bruce, Jennifer L.; O'Connor, Jim; McGee, Benton D.; Holmes, Robert R.; Hollins, Ryan; Forbes, Brandon T.; Kohn, Michael S.; Schellekens, Mathew; Martin, Zachary W.; Peppler, Marie C.

    2016-03-08

    High-water marks provide valuable data for understanding recent and historical flood events. The proper collection and recording of high-water mark data from perishable and preserved evidence informs flood assessments, research, and water resource management. Given the high cost of flooding in developed areas, experienced hydrographers, using the best available techniques, can contribute high-quality data toward efforts such as public education of flood risk, flood inundation mapping, flood frequency computations, indirect streamflow measurement, and hazard assessments.This manual presents guidance for skilled high-water mark identification, including marks left behind in natural and man-made environments by tranquil and rapid flowing water. This manual also presents pitfalls and challenges associated with various types of flood evidence that help hydrographers identify the best high-water marks and assess the uncertainty associated with a given mark. Proficient high-water mark data collection contributes to better understanding of the flooding process and reduces risk through greater ability to estimate flood probability.The U.S. Geological Survey, operating the Nation’s premier water data collection network, encourages readers of this manual to familiarize themselves with the art and science of high-water mark collection. The U.S. Geological survey maintains a national database at http://water.usgs.gov/floods/FEV/ that includes high-water mark information for many flood events, and local U.S. Geological Survey Water Science Centers can provide information to interested readers about participation in data collection and flood documentation efforts as volunteers or observers.

  7. 33 CFR 2.34 - Waters subject to tidal influence; waters subject to the ebb and flow of the tide; mean high water.

    Science.gov (United States)

    2010-07-01

    ...; waters subject to the ebb and flow of the tide; mean high water. 2.34 Section 2.34 Navigation and....34 Waters subject to tidal influence; waters subject to the ebb and flow of the tide; mean high water. (a) Waters subject to tidal influence and waters subject to the ebb and flow of the tide are waters...

  8. Development of a PET Scanner for Simultaneously Imaging Small Animals with MRI and PET

    Directory of Open Access Journals (Sweden)

    Christopher J Thompson

    2014-08-01

    Full Text Available Recently, positron emission tomography (PET is playing an increasingly important role in the diagnosis and staging of cancer. Combined PET and X-ray computed tomography (PET-CT scanners are now the modality of choice in cancer treatment planning. More recently, the combination of PET and magnetic resonance imaging (MRI is being explored in many sites. Combining PET and MRI has presented many challenges since the photo-multiplier tubes (PMT in PET do not function in high magnetic fields, and conventional PET detectors distort MRI images. Solid state light sensors like avalanche photo-diodes (APDs and more recently silicon photo-multipliers (SiPMs are much less sensitive to magnetic fields thus easing the compatibility issues. This paper presents the results of a group of Canadian scientists who are developing a PET detector ring which fits inside a high field small animal MRI scanner with the goal of providing simultaneous PET and MRI images of small rodents used in pre-clinical medical research. We discuss the evolution of both the crystal blocks (which detect annihilation photons from positron decay and the SiPM array performance in the last four years which together combine to deliver significant system performance in terms of speed, energy and timing resolution.

  9. APD-based PET detector for simultaneous PET/MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Grazioso, Ronald [Siemens Molecular Imaging, Knoxville, TN (United States)]. E-mail: ron.grazioso@siemens.com; Zhang, Nan [Siemens Molecular Imaging, Knoxville, TN (United States); Corbeil, James [Siemens Molecular Imaging, Knoxville, TN (United States); Schmand, Matthias [Siemens Molecular Imaging, Knoxville, TN (United States); Ladebeck, Ralf [Siemens AG Medical Solutions MR, Erlangen (Germany); Vester, Markus [Siemens AG Medical Solutions MR, Erlangen (Germany); Schnur, Guenter [Siemens AG Medical Solutions MR, Erlangen (Germany); Renz, Wolfgang [Siemens AG Medical Solutions MR, Erlangen (Germany); Fischer, Hubertus [Siemens AG Medical Solutions MR, Erlangen (Germany)

    2006-12-20

    Two, APD-based, PET modules have been evaluated for use in combined PET/MR imaging. Each module consists of 4 independent, optically isolated detectors. Each detector consists of an 8x8 array of 2x2x20 mm LSO crystals read out by a 2x2 array of 5x5 mm Hamamatsu S8664-55 APDs. The average crystal energy resolution and time resolution (against a plastic scintillator on a PMT) of the detectors was 17% and 1.8 ns, respectively. The modules were positioned in the tunnel of a 1.5 T Siemens Symphony MR scanner. The presence of the PET modules decreased the MR signal-to-noise ratio by about 15% but no image interference was observed. The gradient and RF pulse sequences of the MR produced adverse effects on the PET event signals. These high-frequency pulses did not affect the true PET events but did increase the dead time of the PET system. Simultaneous, artifact-free, images were acquired with the PET and MR system using a small Derenzo phantom. These results show that APD-based PET detectors can be used for a high-resolution and cost-effective integrated PET/MR system.

  10. APD-based PET detector for simultaneous PET/MR imaging

    Science.gov (United States)

    Grazioso, Ronald; Zhang, Nan; Corbeil, James; Schmand, Matthias; Ladebeck, Ralf; Vester, Markus; Schnur, Günter; Renz, Wolfgang; Fischer, Hubertus

    2006-12-01

    Two, APD-based, PET modules have been evaluated for use in combined PET/MR imaging. Each module consists of 4 independent, optically isolated detectors. Each detector consists of an 8×8 array of 2×2×20 mm LSO crystals read out by a 2×2 array of 5×5 mm Hamamatsu S8664-55 APDs. The average crystal energy resolution and time resolution (against a plastic scintillator on a PMT) of the detectors was 17% and 1.8 ns, respectively. The modules were positioned in the tunnel of a 1.5 T Siemens Symphony MR scanner. The presence of the PET modules decreased the MR signal-to-noise ratio by about 15% but no image interference was observed. The gradient and RF pulse sequences of the MR produced adverse effects on the PET event signals. These high-frequency pulses did not affect the true PET events but did increase the dead time of the PET system. Simultaneous, artifact-free, images were acquired with the PET and MR system using a small Derenzo phantom. These results show that APD-based PET detectors can be used for a high-resolution and cost-effective integrated PET/MR system.

  11. Methods for Motion Correction Evaluation Using 18F-FDG Human Brain Scans on a High-Resolution PET Scanner

    DEFF Research Database (Denmark)

    Keller, Sune H.; Sibomana, Merence; Olesen, Oline Vinter

    2012-01-01

    Many authors have reported the importance of motion correction (MC) for PET. Patient motion during scanning disturbs kinetic analysis and degrades resolution. In addition, using misaligned transmission for attenuation and scatter correction may produce regional quantification bias in the reconstr...... and measures improved after MC with AIR, whereas EMT MC performed less well. Conclusion: The 3 presented QC methods produced similar results and are useful for evaluating tracer-independent external-tracking motion-correction methods for human brain scans....... in the reconstructed emission images. The purpose of this work was the development of quality control (QC) methods for MC procedures based on external motion tracking (EMT) for human scanning using an optical motion tracking system. Methods: Two scans with minor motion and 5 with major motion (as reported...

  12. Water-level change, High Plains aquifer, 2005 to 2009

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This raster data set represents water-level change in the High Plains aquifer of the United States from 2005 to 2009, in feet. The High Plains aquifer underlies...

  13. Water-level change, High Plains aquifer, 1980 to 1995

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This raster data set represents water-level change in the High Plains aquifer of the United States from 1980 to 1995, in feet. The High Plains aquifer underlies...

  14. Water-level change, High Plains aquifer, 1995 to 2000

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This raster data set represents water-level change in the High Plains aquifer of the United States from 1995 to 2000, in feet. The High Plains aquifer underlies...

  15. Water-level change, High Plains aquifer, 2000 to 2005

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This raster data set represents water-level change in the High Plains aquifer of the United States from 2000 to 2005, in feet. The High Plains aquifer underlies...

  16. Pet ownership and adolescent health: cross-sectional population study.

    Science.gov (United States)

    Mathers, Megan; Canterford, Louise; Olds, Tim; Waters, Elizabeth; Wake, Melissa

    2010-12-01

    To determine whether adolescent health and well-being are associated with having a pet in the household (any pet, or specifically dogs, cats or horses/ponies) or average daily time spent caring for/playing with pet(s). Design, setting and participants--Cross-sectional data from the third wave of the Health of Young Victorians Study (HOYVS), a school-based population study in Victoria, Australia. Predictors--Adolescent-reported pet ownership and average daily time spent caring for/playing with pet(s). Outcomes--Self-reported quality of life (KIDSCREEN); average 4-day daily physical activity level from a computerised diary; parent-proxy and self-reported physical and psychosocial health status (PedsQL); measured BMI status (not overweight, overweight, obese) and blood pressure. Statistical Analysis--Regression methods, adjusted for socio-demographic factors, and non-parametric methods. Household pet data were available for 928 adolescents (466 boys; mean age of 15.9 (SD 1.2) years). Most adolescents (88.7%) reported having a pet in their household. Of these, 75.1% reported no activity involving pets over the surveyed days. It appeared that neither owning a pet nor time spent caring for/playing with a pet was related, positively or negatively, to adolescent health or well-being. Despite high rates of pet ownership, adolescents had little interaction with pets. It appears that owning a pet and time spent caring for/playing with a pet was not clearly associated with adolescents' health or well-being. © 2010 The Authors. Journal of Paediatrics and Child Health © 2010 Paediatrics and Child Health Division (Royal Australasian College of Physicians).

  17. The performance of monotonic and new non-monotonic gradient ascent reconstruction algorithms for high-resolution neuroreceptor PET imaging

    Energy Technology Data Exchange (ETDEWEB)

    Angelis, G I; Kotasidis, F A; Matthews, J C [Imaging, Proteomics and Genomics, MAHSC, University of Manchester, Wolfson Molecular Imaging Centre, Manchester (United Kingdom); Reader, A J [Montreal Neurological Institute, McGill University, Montreal (Canada); Lionheart, W R, E-mail: georgios.angelis@mmic.man.ac.uk [School of Mathematics, University of Manchester, Alan Turing Building, Manchester (United Kingdom)

    2011-07-07

    Iterative expectation maximization (EM) techniques have been extensively used to solve maximum likelihood (ML) problems in positron emission tomography (PET) image reconstruction. Although EM methods offer a robust approach to solving ML problems, they usually suffer from slow convergence rates. The ordered subsets EM (OSEM) algorithm provides significant improvements in the convergence rate, but it can cycle between estimates converging towards the ML solution of each subset. In contrast, gradient-based methods, such as the recently proposed non-monotonic maximum likelihood (NMML) and the more established preconditioned conjugate gradient (PCG), offer a globally convergent, yet equally fast, alternative to OSEM. Reported results showed that NMML provides faster convergence compared to OSEM; however, it has never been compared to other fast gradient-based methods, like PCG. Therefore, in this work we evaluate the performance of two gradient-based methods (NMML and PCG) and investigate their potential as an alternative to the fast and widely used OSEM. All algorithms were evaluated using 2D simulations, as well as a single [{sup 11}C]DASB clinical brain dataset. Results on simulated 2D data show that both PCG and NMML achieve orders of magnitude faster convergence to the ML solution compared to MLEM and exhibit comparable performance to OSEM. Equally fast performance is observed between OSEM and PCG for clinical 3D data, but NMML seems to perform poorly. However, with the addition of a preconditioner term to the gradient direction, the convergence behaviour of NMML can be substantially improved. Although PCG is a fast convergent algorithm, the use of a (bent) line search increases the complexity of the implementation, as well as the computational time involved per iteration. Contrary to previous reports, NMML offers no clear advantage over OSEM or PCG, for noisy PET data. Therefore, we conclude that there is little evidence to replace OSEM as the algorithm of choice

  18. In vitro and in vivo evaluation of a (18F-labeled high affinity NOTA conjugated bombesin antagonist as a PET ligand for GRPR-targeted tumor imaging.

    Directory of Open Access Journals (Sweden)

    Zohreh Varasteh

    Full Text Available Expression of the gastrin-releasing peptide receptor (GRPR in prostate cancer suggests that this receptor can be used as a potential molecular target to visualize and treat these tumors. We have previously investigated an antagonist analog of bombesin (D-Phe-Gln-Trp-Ala-Val-Gly-His-Sta-Leu-NH2, RM26 conjugated to 1,4,7-triazacyclononane-N,N',N''-triacetic acid (NOTA via a diethylene glycol (PEG2 spacer (NOTA-P2-RM26 labeled with (68Ga and (111In. We found that this conjugate has favorable properties for in vivo imaging of GRPR-expression. The focus of this study was to develop a (18F-labelled PET agent to visualize GRPR. NOTA-P2-RM26 was labeled with (18F using aluminum-fluoride chelation. Stability, in vitro binding specificity and cellular processing tests were performed. The inhibition efficiency (IC50 of the [(natF]AlF-NOTA-P2-RM26 was compared to that of the (natGa-loaded peptide using (125I-Tyr(4-BBN as the displacement radioligand. The pharmacokinetics and in vivo binding specificity of the compound were studied. NOTA-P2-RM26 was labeled with (18F within 1 h (60-65% decay corrected radiochemical yield, 55 GBq/µmol. The radiopeptide was stable in murine serum and showed high specific binding to PC-3 cells. [(natF]AlF-NOTA-P2-RM26 showed a low nanomolar inhibition efficiency (IC50=4.4±0.8 nM. The internalization rate of the tracer was low. Less than 14% of the cell-bound radioactivity was internalized after 4 h. The biodistribution of [(18F]AlF-NOTA-P2-RM26 demonstrated rapid blood clearance, low liver uptake and low kidney retention. The tumor uptake at 3 h p.i. was 5.5±0.7 %ID/g, and the tumor-to-blood, -muscle and -bone ratios were 87±42, 159±47, 38±16, respectively. The uptake in tumors, pancreas and other GRPR-expressing organs was significantly reduced when excess amount of non-labeled peptide was co-injected. The low uptake in bone suggests a high in vivo stability of the Al-F bond. High contrast PET image was obtained 3 h p

  19. Quantitative, Simultaneous PET/MRI for Intratumoral Imaging with an MRI-Compatible PET Scanner

    Science.gov (United States)

    Ng, Thomas S.C.; Bading, James R.; Park, Ryan; Sohi, Hargun; Procissi, Daniel; Colcher, David; Conti, Peter S.; Cherry, Simon R.; Raubitschek, Andrew A.; Jacobs, Russell E.

    2012-01-01

    Noninvasive methods are needed to explore the heterogeneous tumor microenvironment and its modulation by therapy. Hybrid PET/MRI systems are being developed for small-animal and clinical use. The advantage of these integrated systems depends on their ability to provide MR images that are spatially coincident with simultaneously acquired PET images, allowing combined functional MRI and PET studies of intratissue heterogeneity. Although much effort has been devoted to developing this new technology, the issue of quantitative and spatial fidelity of PET images from hybrid PET/MRI systems to the tissues imaged has received little attention. Here, we evaluated the ability of a first-generation, small-animal MRI-compatible PET scanner to accurately depict heterogeneous patterns of radiotracer uptake in tumors. Methods Quantitative imaging characteristics of the MRI-compatible PET (PET/MRI) scanner were evaluated with phantoms using calibration coefficients derived from a mouse-sized linearity phantom. PET performance was compared with a commercial small-animal PET system and autoradiography in tumor-bearing mice. Pixel and structure-based similarity metrics were used to evaluate image concordance among modalities. Feasibility of simultaneous PET/MRI functional imaging of tumors was explored by following 64Cu-labeled antibody uptake in relation to diffusion MRI using cooccurrence matrix analysis. Results The PET/MRI scanner showed stable and linear response. Activity concentration recovery values (measured and true activity concentration) calculated for 4-mm-diameter rods within linearity and uniform activity rod phantoms were near unity (0.97 ± 0.06 and 1.03 ± 0.03, respectively). Intratumoral uptake patterns for both 18F-FDG and a 64Cu-antibody acquired using the PET/MRI scanner and small-animal PET were highly correlated with autoradiography (r > 0.99) and with each other (r = 0.97 ± 0.01). On the basis of these data, we performed a preliminary study comparing

  20. Quantitative carotid PET/MR imaging: clinical evaluation of MR-Attenuation correction versus CT-Attenuation correction in (18)F-FDG PET/MR emission data and comparison to PET/CT.

    Science.gov (United States)

    Bini, Jason; Robson, Philip M; Calcagno, Claudia; Eldib, Mootaz; Fayad, Zahi A

    2015-01-01

    Current PET/MR systems employ segmentation of MR images and subsequent assignment of empirical attenuation coefficients for quantitative PET reconstruction. In this study we examine the differences in the quantification of (18)F-FDG uptake in the carotid arteries between PET/MR and PET/CT scanners. Five comparisons were performed to asses differences in PET quantification: i) PET/MR MR-based AC (MRAC) versus PET/MR CTAC, ii) PET/MR MRAC versus PET/CT, iii) PET/MR MRAC with carotid coil versus PET/MR MRAC without coil, iv) PET/MR MRAC scan 2 versus PET/MR MRAC scan 1, and v) PET/MR CTAC versus PET/CT. Standardized uptakes values (SUV) mean and SUV maximum were calculated for six regions-of-interests: left and right carotid arteries, left and right lungs, spine and muscle. Pearson's Correlation and Bland-Altman plots were used to compare SUV mean and maximum within each ROI of each patient. PET/MR emission data reconstructed with MRAC versus PET/MR emission data reconstructed with CTAC had percent differences of SUV mean ranging from -2.0% (Absolute Difference, -0.02) to 7.4% (absolute difference, 0.06). Percent differences within the carotid arteries proved to correlate well with differences of SUV mean of 5.4% (Absolute Difference, 0.07) in the left carotid and 2.7% (Absolute Difference, 0.03) in the right carotid. Pearson's correlation and Bland-Altman of PET/MR with MRAC versus PET/MR with CTAC showed high correlation between SUV mean (R(2)=0.80, mean difference 0.03 ± 0.18 SUV, p=0.3382), demonstrating excellent correlation within ROIs analyzed. The results of this study support the use of (18)F-FDG PET/MR for quantitative measure of inflammation in the carotid arteries.

  1. Quantitative carotid PET/MR imaging: clinical evaluation of MR-Attenuation correction versus CT-Attenuation correction in 18F-FDG PET/MR emission data and comparison to PET/CT

    Science.gov (United States)

    Bini, Jason; Robson, Philip M; Calcagno, Claudia; Eldib, Mootaz; Fayad, Zahi A

    2015-01-01

    Current PET/MR systems employ segmentation of MR images and subsequent assignment of empirical attenuation coefficients for quantitative PET reconstruction. In this study we examine the differences in the quantification of 18F-FDG uptake in the carotid arteries between PET/MR and PET/CT scanners. Five comparisons were performed to asses differences in PET quantification: i) PET/MR MR-based AC (MRAC) versus PET/MR CTAC, ii) PET/MR MRAC versus PET/CT, iii) PET/MR MRAC with carotid coil versus PET/MR MRAC without coil, iv) PET/MR MRAC scan 2 versus PET/MR MRAC scan 1, and v) PET/MR CTAC versus PET/CT. Standardized uptakes values (SUV) mean and SUV maximum were calculated for six regions-of-interests: left and right carotid arteries, left and right lungs, spine and muscle. Pearson’s Correlation and Bland-Altman plots were used to compare SUV mean and maximum within each ROI of each patient. PET/MR emission data reconstructed with MRAC versus PET/MR emission data reconstructed with CTAC had percent differences of SUV mean ranging from -2.0% (Absolute Difference, -0.02) to 7.4% (absolute difference, 0.06). Percent differences within the carotid arteries proved to correlate well with differences of SUV mean of 5.4% (Absolute Difference, 0.07) in the left carotid and 2.7% (Absolute Difference, 0.03) in the right carotid. Pearson’s correlation and Bland-Altman of PET/MR with MRAC versus PET/MR with CTAC showed high correlation between SUV mean (R2=0.80, mean difference 0.03 ± 0.18 SUV, p=0.3382), demonstrating excellent correlation within ROIs analyzed. The results of this study support the use of 18F-FDG PET/MR for quantitative measure of inflammation in the carotid arteries. PMID:26069863

  2. Spectral characteristics of high shallow water waves

    Digital Repository Service at National Institute of Oceanography (India)

    SanilKumar, V.; AshokKumar, K.

    –Moskowitz and Kitaigordskii et al. (1975) for the south-west coast of India. Ochi and Hubble (1976) found that JONSWAP spectrum provided good approx- imation to the data for the uni-model spectra with mean JONSWAP parameters of g (peak enhancement para- meter) ¼ 2.2 and a.... 4.1–4.55. Young, I.R., 1992. The determination of spectral parameters from significant wave height and peak period. Ocean Engineering 19 (5), 497–508. Young, I.R., Verhagen, L.A., 1996. The growth of fetch limited waves in water of finite depth: Part...

  3. Highly energetic phenomena in water electrolysis.

    Science.gov (United States)

    Postnikov, A V; Uvarov, I V; Lokhanin, M V; Svetovoy, V B

    2016-12-16

    Water electrolysis performed in microsystems with a fast change of voltage polarity produces optically invisible nanobubbles containing H2 and O2 gases. In this form the gases are able to the reverse reaction of water formation. Here we report extreme phenomena observed in a millimeter-sized open system. Under a frequency of driving pulses above 100 kHz the process is accompanied by clicking sounds repeated every 50 ms or so. Fast video reveals that synchronously with the click a bubble is growing between the electrodes which reaches a size of 300 μm in 50 μs. Detailed dynamics of the system is monitored by means of a vibrometer by observing a piece of silicon floating above the electrodes. The energy of a single event is estimated as 0.3 μJ and a significant part of this energy is transformed into mechanical work moving the piece. The observations are explained by the combustion of hydrogen and oxygen mixture in the initial bubble with a diameter of about 40 μm. Unusual combustion mechanism supporting spontaneous ignition at room temperature is responsible for the process. The observed effect demonstrates a principal possibility to build a microscopic internal combustion engine.

  4. Highly energetic phenomena in water electrolysis

    Science.gov (United States)

    Postnikov, A. V.; Uvarov, I. V.; Lokhanin, M. V.; Svetovoy, V. B.

    2016-12-01

    Water electrolysis performed in microsystems with a fast change of voltage polarity produces optically invisible nanobubbles containing H2 and O2 gases. In this form the gases are able to the reverse reaction of water formation. Here we report extreme phenomena observed in a millimeter-sized open system. Under a frequency of driving pulses above 100 kHz the process is accompanied by clicking sounds repeated every 50 ms or so. Fast video reveals that synchronously with the click a bubble is growing between the electrodes which reaches a size of 300 μm in 50 μs. Detailed dynamics of the system is monitored by means of a vibrometer by observing a piece of silicon floating above the electrodes. The energy of a single event is estimated as 0.3 μJ and a significant part of this energy is transformed into mechanical work moving the piece. The observations are explained by the combustion of hydrogen and oxygen mixture in the initial bubble with a diameter of about 40 μm. Unusual combustion mechanism supporting spontaneous ignition at room temperature is responsible for the process. The observed effect demonstrates a principal possibility to build a microscopic internal combustion engine.

  5. Water quality monitoring for high-priority water bodies in the Sonoran Desert network

    Science.gov (United States)

    Terry W. Sprouse; Robert M. Emanuel; Sara A. Strorrer

    2005-01-01

    This paper describes a network monitoring program for “high priority” water bodies in the Sonoran Desert Network of the National Park Service. Protocols were developed for monitoring selected waters for ten of the eleven parks in the Network. Park and network staff assisted in identifying potential locations of testing sites, local priorities, and how water quality...

  6. High performance volume-of-intersection projectors for 3D-PET image reconstruction based on polar symmetries and SIMD vectorisation

    Science.gov (United States)

    Scheins, J. J.; Vahedipour, K.; Pietrzyk, U.; Shah, N. J.

    2015-12-01

    For high-resolution, iterative 3D PET image reconstruction the efficient implementation of forward-backward projectors is essential to minimise the calculation time. Mathematically, the projectors are summarised as a system response matrix (SRM) whose elements define the contribution of image voxels to lines-of-response (LORs). In fact, the SRM easily comprises billions of non-zero matrix elements to evaluate the tremendous number of LORs as provided by state-of-the-art PET scanners. Hence, the performance of iterative algorithms, e.g. maximum-likelihood-expectation-maximisation (MLEM), suffers from severe computational problems due to the intensive memory access and huge number of floating point operations. Here, symmetries occupy a key role in terms of efficient implementation. They reduce the amount of independent SRM elements, thus allowing for a significant matrix compression according to the number of exploitable symmetries. With our previous work, the PET REconstruction Software TOolkit (PRESTO), very high compression factors (>300) are demonstrated by using specific non-Cartesian voxel patterns involving discrete polar symmetries. In this way, a pre-calculated memory-resident SRM using complex volume-of-intersection calculations can be achieved. However, our original ray-driven implementation suffers from addressing voxels, projection data and SRM elements in disfavoured memory access patterns. As a consequence, a rather limited numerical throughput is observed due to the massive waste of memory bandwidth and inefficient usage of cache respectively. In this work, an advantageous symmetry-driven evaluation of the forward-backward projectors is proposed to overcome these inefficiencies. The polar symmetries applied in PRESTO suggest a novel organisation of image data and LOR projection data in memory to enable an efficient single instruction multiple data vectorisation, i.e. simultaneous use of any SRM element for symmetric LORs. In addition, the calculation

  7. Oral cancer diagnosed using PET/CT: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Hee; Yang, Byoung Eun; Cho, Young Min [Hallym Univ. College of Medicine, Anyang (Korea, Republic of); Kim, Seong Gon [Sam Anyang General Hospital, Anyang (Korea, Republic of)

    2006-06-15

    PET/CT is a new imaging technology that combines high-quality Position Emission Tomography (PET) and Computed Tomography (CT). This imaging provides simultaneous anatomical and metabolic information. Therefore PET/CT is useful diagnostic modality for early detection og malignant tumor, accurate at aging, decision on therapeutic plan, monitoring response to therapy and rapid detection of recurrence. We report oral and maxillofacial cancers diagnosed by using PET/CT and the usefulness of PET/CT in the evaluation of postoperative recurrence.

  8. PET/CT and PET/MRI in head and neck malignancy.

    Science.gov (United States)

    Szyszko, T A; Cook, G J R

    2018-01-01

    Combined 2-[18F]-fluoro-2-deoxy-d-glucose (FDG) positron-emission tomography (PET)/computed tomography (CT) has an established role in the staging of difficult cases of head and neck (HN) squamous cell carcinoma (SCC), looking for an unknown primary, assessing response post-chemotherapy at 3-6 months, and differentiating relapse from treatment effects in patients suspected to have tumour recurrence. The PET NECK trial, comparing PET/CT surveillance versus neck dissection in advanced head and neck cancer showed survival was similar among patients who underwent PET/CT-guided surveillance and those who underwent planned neck dissection, but surveillance was more cost-effective. There is growing interest in the use of hypoxia PET tracers, especially in targeting radiotherapy, where the radiotherapy dose can be boosted in regions of hypoxia; the use of 68Ga peptide tracers in neuroendocrine malignancy and also in the growing field of combined PET/magnetic resonance imaging (MRI). PET/MRI has the advantage of increased anatomical detail and radiation dose reduction combined with the molecular and metabolic data from PET, although PET/CT has the advantage in better sensitivity for imaging lung metastases. Thus far, there is good agreement between PET/CT and PET/MRI with high correlation between semi-quantitative measurements in primary, nodal, osseous, and soft-tissue lesions imaging. PET/MRI may indeed provide greater accuracy than the currently available imaging procedures in the staging and later treatment response evaluation in HNSCC. Copyright © 2017. Published by Elsevier Ltd.

  9. Dedicated brain PET system of PET/MR for brain research

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Li; Liu, Yaqiang; Ma, Tianyu; Wang, Shi; Wei, Qingyang; Xu, Tianpeng [Institute of Medical Physics, Department of Engineering Physics, Tsinghua University, Beijing (China)

    2015-05-18

    This work is to replace PET ring in human brain PET/MR system with a dedicated wearable PET insert, aimed at improving both patient feasibility and system performance for brain imaging. The designed PET/MR system includes two parts: the inside parts, including a radio frequency (RF) coil and PET ring, are mounted on patient’s head, and the outside part, a MR imager, is dependent of patient. The RF coil is the innermost layer, surrounded by an outer PET-ring layer. They are supported by a MRcompatible structure. And both RF coil and PET detectors are placed inside a standard clinical 3-T MR imager. From the design of the system we can infer that some advantages can be achieved. First, high sensitivity will be achieved with the same amount crystals as the PET ring is more close to region-of-interest area, at a reduced cost. Second, by using a 2-layer depth of interaction (DOI) detector, the parallax effect can be minimized. The resolution will benefit from short positron range caused by magnetic field and smaller ring diameter will also reduce the effect of non-collinearity. Thirdly, as the PET ring is mounted on head, impact of patient motion will be reduced.

  10. Indikationer for anvendelse af PET eller PET/CT hos patienter med brystkræft

    DEFF Research Database (Denmark)

    Bernsdorf, Mogens; Graff, Jesper

    2011-01-01

    PET and PET/CT, using 18F-fluoro-2-deoxy-D-glucose, are not suited for primary diagnostics of small tumours or lymph node metastases to the axilla. In return, the method has a high sensitivity and specificity regarding the detection of loco-regional recurrence and metastases to mediastinal lymph...

  11. Comparison of (68)Ga-PSMA-11 PET-CT with mpMRI for preoperative lymph node staging in patients with intermediate to high-risk prostate cancer.

    Science.gov (United States)

    Zhang, Qing; Zang, Shiming; Zhang, Chengwei; Fu, Yao; Lv, Xiaoyu; Zhang, Qinglei; Deng, Yongming; Zhang, Chuan; Luo, Rui; Zhao, Xiaozhi; Wang, Wei; Wang, Feng; Guo, Hongqian

    2017-11-07

    To evaluate the diagnostic value of (68)Ga-PSMA-11 PET-CT with multiparametric magnetic resonance imaging (mpMRI) for lymph node (LN) staging in patients with intermediate- to high-risk prostate cancer (PCa) undergoing radical prostatectomy (RP) with pelvic lymph node dissection (PLND). We retrospectively identified 42 consecutive patients with intermediate- to high-risk PCa according to D'Amico and without concomitant cancer. Preoperative (68)Ga-PSMA-11 PET-CT, pelvic mpMRI and subsequent robot assisted laparoscopic RP with PLND were performed in all patients. Among 42 patients assessed, the preoperative PSA value, Gleason score, pT stage and intraprostatic PCa volume of patients with LN metastases were all significantly higher than those without metastases (P = 0.029, 0.028, 0.004, respectively). The average maximum standardized uptake value (SUV) of (68)Ga-PSMA-11 PET-CT positive PCa of patients with or without LN metastases were 13.10 (range 6.12-51.75) and 7.22 (range 5.4-11.2), respectively (P PET-CT and pelvic mpMRI had the ability of succeed on preoperative definite accurate diagnosis and accurate localization of primary PCa in all 42 patients. Fifteen patients (35.71%) had a pN1 stage. 51 positive LN were found. Both (68)Ga-PSMA-11 PET-CT and pelvic mpMRI displayed brillient patient-based and region-based sensitivity, specificity, negative predictive value and positive predictive value. There was no statistical difference for the detection of LNMs according to the diameter of the LNMs between (68)Ga-PSMA-11 PET-CT and mpMRI in this study. Both (68)Ga-PSMA-11 PET-CT and mpMRI performed great value for LN staging in patients with intermediate- to high-risk PCa undergoing RP with PLND. However, despite excellent performance of (68)Ga-PSMA-11 PET-CT, it cannot replace mpMRI that remains excellent for lymph node staging.

  12. Treatment of Highly Turbid Water by Polyaluminum Ferric Chloride (PAFCL

    Directory of Open Access Journals (Sweden)

    Fazel Fazel Mohammadi-Moghaddam

    2015-10-01

    Full Text Available Background & Aims of the Study: In some situation like rainfall seasons raw water become very turbid so it affected the water treatment plant processes and quality of produced water. Treatment of very high turbid water has some concerns like precursors for disinfection by-products and very loading rate of particle on filter's media and consequently increases in water consumption for filter backwash. This paper investigates the performance of a composite inorganic polymer of aluminium and ferric salt, Polyaluminium ferric chloride (PAFCl, for the removal of turbidity, color and natural organic matter (NOM from high turbid water. Materials and Methods: Experiments were carried out by Jar test experiment by synthetic water samples with 250 and 500 NTU turbidity that prepared in laboratory. Results: The results of conventional jar test showed that the optimum pH for coagulation of water sample was 7.5 to 8 and optimum dosage of the coagulant was 10 mg/L. Removal efficiency of turbidity, color and UV adsorbent at 254 nm at optimum dose and pH without filtration was 99.92%, 100% and 80.6% respectively for first sample (250 NTU and 99.95%, 99.49% and 84.77 for second sample (500 NTU respectively. Conclusion: It concluded that polyaluminium ferric chloride has a very good efficiency for the removal of turbidity, color and organic matter in high turbid water. Also it can be select as a coagulant for high turbid water and some waste water from water treatment plant like filter backwash water.

  13. 4-D PET-MR with Volumetric Navigators and Compressed Sensing

    OpenAIRE

    Pedemonte, Stefano; Catana, Ciprian; Van Leemput, Koen

    2015-01-01

    Hybrid PET-MR scanners acquire multi-modal signals simultaneously, eliminating the requirement of software alignment between the MR and PET imaging data. However, the acquisition of high-resolution MR and PET images requires long scanning times, therefore movement of the subject during the acquisition deteriorates both the PET and the MR images. In this work we have developed an approach for tightly integrated PET-MR imaging, making use of volumetric MR navigators to inform, in real-time, bot...

  14. Early detection and longitudinal monitoring of experimental primary and disseminated melanoma using [{sup 18}F]ICF01006, a highly promising melanoma PET tracer

    Energy Technology Data Exchange (ETDEWEB)

    Rbah-Vidal, Latifa; Vidal, Aurelien; Besse, Sophie; Audin, Laurent; Degoul, Francoise; Miot-Noirault, Elisabeth; Moins, Nicole; Auzeloux, Philippe; Chezal, Jean-Michel [Clermont Universite, Universite d' Auvergne, Imagerie Moleculaire et Therapie Vectorisee, BP 10448, Clermont-Ferrand (France); Inserm, U 990, Clermont-Ferrand (France); Cachin, Florent [Clermont Universite, Universite d' Auvergne, Imagerie Moleculaire et Therapie Vectorisee, BP 10448, Clermont-Ferrand (France); Inserm, U 990, Clermont-Ferrand (France); Centre Jean Perrin, Clermont-Ferrand (France); Bonnet, Mathilde [U1071 INSERM-Universite d' Auvergne, M2USH, Clermont-Ferrand (France); Askienazy, Serge [CYCLOPHARMA Laboratories, Biopole Clermont-Limagne, Saint-Beauzire (France); Dolle, Frederic [CEA, I2BM, Service Hospitalier Frederic Joliot, Orsay (France)

    2012-09-15

    Here, we report a new and rapid radiosynthesis of {sup 18}F-N-[2-(diethylamino)ethyl]-6-fluoro-pyridine-3-carboxamide ([{sup 18}F]ICF01006), a molecule with a high specificity for melanotic tissue, and its evaluation in a murine model for early specific detection of pigmented primary and disseminated melanoma. [{sup 18}F]ICF01006 was synthesized using a new one-step bromine-for-fluorine nucleophilic heteroaromatic substitution. Melanoma models were induced by subcutaneous (primary tumour) or intravenous (lung colonies) injection of B16BL6 melanoma cells in C57BL/6J mice. The relevance and sensitivity of positron emission tomography (PET) imaging using [{sup 18}F]ICF01006 were evaluated at different stages of tumoural growth and compared to {sup 18}F-fluorodeoxyglucose ([{sup 18}F]FDG). The fully automated radiosynthesis of [{sup 18}F]ICF01006 led to a radiochemical yield of 61 % and a radiochemical purity >99 % (specific activity 70-80 GBq/{mu}mol; total synthesis time 42 min). Tumours were visualized before they were palpable as early as 1 h post-injection with [{sup 18}F]ICF01006 tumoural uptake of 1.64 {+-} 0.57, 3.40 {+-} 1.47 and 11.44 {+-} 2.67 percentage of injected dose per gram of tissue (%ID/g) at days 3, 5 and 14, respectively. [{sup 18}F]ICF01006 PET imaging also allowed detection of melanoma pulmonary colonies from day 9 after tumour cell inoculation, with a lung radiotracer accumulation correlated with melanoma invasion. At day 21, radioactivity uptake in lungs reached a value of 5.23 {+-} 2.08 %ID/g (versus 0.41 {+-} 0.90 %ID/g in control mice). In the two models, comparison with [{sup 18}F]FDG showed that both radiotracers were able to detect melanoma lesions, but [{sup 18}F]ICF01006 was superior in terms of contrast and specificity. Our promising results provide further preclinical data, reinforcing the excellent potential of [{sup 18}F]ICF01006 PET imaging for early specific diagnosis and follow-up of melanin-positive disseminated melanoma. (orig.)

  15. Dynamic PET denoising with HYPR processing

    National Research Council Canada - National Science Library

    Christian, Bradley T; Vandehey, Nicholas T; Floberg, John M; Mistretta, Charles A

    2010-01-01

    HighlY constrained backPRojection (HYPR) is a promising image-processing strategy with widespread application in time-resolved MRI that is also well suited for PET applications requiring time series data...

  16. The Effect of Magnetic Field on Positron Range and Spatial Resolution in an Integrated Whole-Body Time-Of-Flight PET/MRI System.

    Science.gov (United States)

    Huang, Shih-Ying; Savic, Dragana; Yang, Jaewon; Shrestha, Uttam; Seo, Youngho

    2014-11-01

    Simultaneous imaging systems combining positron emission tomography (PET) and magnetic resonance imaging (MRI) have been actively investigated. A PET/MR imaging system (GE Healthcare) comprised of a time-of-flight (TOF) PET system utilizing silicon photomultipliers (SiPMs) and 3-tesla (3T) MRI was recently installed at our institution. The small-ring (60 cm diameter) TOF PET subsystem of this PET/MRI system can generate images with higher spatial resolution compared with conventional PET systems. We have examined theoretically and experimentally the effect of uniform magnetic fields on the spatial resolution for high-energy positron emitters. Positron emitters including 18F, 124I, and 68Ga were simulated in water using the Geant4 Monte Carlo toolkit in the presence of a uniform magnetic field (0, 3, and 7 Tesla). The positron annihilation position was tracked to determine the 3D spatial distribution of the 511-keV gammy ray emission. The full-width at tenth maximum (FWTM) of the positron point spread function (PSF) was determined. Experimentally, 18F and 68Ga line source phantoms in air and water were imaged with an investigational PET/MRI system and a PET/CT system to investigate the effect of magnetic field on the spatial resolution of PET. The full-width half maximum (FWHM) of the line spread function (LSF) from the line source was determined as the system spatial resolution. Simulations and experimental results show that the in-plane spatial resolution was slightly improved at field strength as low as 3 Tesla, especially when resolving signal from high-energy positron emitters in the air-tissue boundary.

  17. PET/MRI and PET/CT in follow-up of head and neck cancer patients

    Energy Technology Data Exchange (ETDEWEB)

    Queiroz, Marcelo A. [University Hospital Zurich, Department of Medical Radiology, Nuclear Medicine, Zurich (Switzerland); University Hospital Zurich, Department of Nuclear Medicine, Zurich (Switzerland); Huellner, Martin [University Hospital Zurich, Department of Medical Radiology, Nuclear Medicine, Zurich (Switzerland); University Hospital Zurich, Department of Medical Radiology, Neuroradiology, Zurich (Switzerland); Kuhn, Felix; Veit-Haibach, Patrick [University Hospital Zurich, Department of Medical Radiology, Nuclear Medicine, Zurich (Switzerland); University Hospital Zurich, Department of Medical Radiology, Diagnostic and Interventional Radiology, Zurich (Switzerland); Huber, Gerhardt; Meerwein, Christian [University Hospital Zurich, Department of Otorhinolaryngology, Zurich (Switzerland); Kollias, Spyros [University Hospital Zurich, Department of Medical Radiology, Neuroradiology, Zurich (Switzerland); Schulthess, Gustav von [University Hospital Zurich, Department of Medical Radiology, Nuclear Medicine, Zurich (Switzerland)

    2014-06-15

    Positron emission tomography (PET)/MRI combines the functional ability of PET and the high soft tissue contrast of MRI. The aim of this study was to assess contrast-enhanced (ce)PET/MRI compared to cePET/CT in patients with suspected recurrence of head and neck cancer (HNC). Eighty-seven patients underwent sequential cePET/CT and cePET/MRI using a trimodality PET/CT-MRI set-up. Diagnostic accuracy for the detection of recurrent HNC was evaluated using cePET/CT and cePET/MRI. Furthermore, image quality, presence of unclear {sup 18}F-fluorodeoxy-D-glucose (FDG) findings of uncertain significance and the diagnostic advantages of use of gadolinium contrast enhancement were analysed. cePET/MRI showed no statistically significant difference in diagnostic accuracy compared to cePET/CT (91.5 vs 90.6 %). Artefacts' grade was similar in both methods, but their location was different. cePET/CT artefacts were primarily located in the suprahyoid area, while on cePET/MRI, artefacts were more equally distributed among the supra and infrahyoid neck regions. cePET/MRI and cePET/CT showed 34 unclear FDG findings; of those 11 could be solved by cePET/MRI and 5 by cePET/CT. The use of gadolinium in PET/MRI did not yield higher diagnostic accuracy, but helped to better define tumour margins in 6.9 % of patients. Our data suggest that cePET/MRI may be superior compared to cePET/CT to specify unclear FDG uptake related to possible tumour recurrence in follow-up of patients after HNC. It seems to be the modality of choice for the evaluation of the oropharynx and the oral cavity because of a higher incidence of artefacts in cePET/CT in this area mainly due to dental implants. However, overall there is no statistically significant difference. (orig.)

  18. Volume analysis of supercooled water under high pressure

    OpenAIRE

    Duki, Solomon F.; Tsige, Mesfin

    2016-01-01

    Motivated by recent experimental findings on the volume of supercooled water at high pressure [O. Mishima, J. Chem. Phys. 133, 144503 (2010)] we performed atomistic molecular dynamics simulations study of bulk water in the isothermal-isobaric ensemble. Cooling and heating cycles at different isobars and isothermal compression at different temperatures are performed on the water sample with pressures that range from 0 to 1.0 GPa. The cooling simulations are done at temperatures that range from...

  19. Glycerin Reformation in High Temperature and Pressure Water

    Science.gov (United States)

    2012-01-01

    hygroscopic, while ethanol is renewable and non-toxic (94). Water has a detrimental effect on the reaction because soaps can be formed, which cause...Lavric, V. (2005) Delocalized organic pollutant destruction through a self-sustaining supercritical water oxidation process, Energy Conversion and...2012 2. REPORT TYPE 3. DATES COVERED 00-00-2012 to 00-00-2012 4. TITLE AND SUBTITLE Glycerin Reformation in High Temperature and Pressure Water

  20. Non FDG PET

    Energy Technology Data Exchange (ETDEWEB)

    Nanni, C., E-mail: cristina.nanni@aosp.bo.i [Nuclear Medicine Unit, Policlinico S.Orsola, University of Bologna, Bologna (Italy); Fantini, L.; Nicolini, S.; Fanti, S. [Nuclear Medicine Unit, Policlinico S.Orsola, University of Bologna, Bologna (Italy)

    2010-07-15

    2- [{sup 18}F]-fluoro-2-deoxy-D-glucose (FDG) is the radiopharmaceutical most frequently used for clinical positron emission tomography (PET). However, FDG cannot be used for many oncological, cardiological, or neurological conditions, either because the abnormal tissue does not concentrate it, or because the tissues under investigation demonstrate high physiological glucose uptake. Consequently, alternative PET tracers have been produced and introduced into clinical practice. The most important compounds in routine practice are {sup 11}C-choline and {sup 18}F-choline, mainly for the evaluation of prostate cancer; {sup 1}C-methionine for brain tumours; {sup 118}F-DOPA ({sup 18}F- deoxiphenilalanine) for neuroendocrine tumours and movement disorders; {sup 68}Ga-DOTANOC (tetraazacyclododecanetetraacetic acid-[1-Nal3]-octreotide) and other somatostatin analogues for neuroendocrine tumours; 11C-acetate for prostate cancer and hepatic masses and 18F-FLT (3'-deoxy-3'-fluorothymidine) for a number of malignant tumours. Another impetus for the development of new tracers is to enable the investigation of biological processes in tumours other than glucose metabolism. This is especially important in the field of response assessment, where there are new agents that are targeted more specifically at angiogenesis, hypoxia, apoptosis and other processes.

  1. The distribution of FDG at PET examinations constitutes a relative mechanism: significant effects at activity quantification in patients with a high muscular uptake

    Energy Technology Data Exchange (ETDEWEB)

    Lindholm, Henry; Johansson, Ove; Jacobsson, Hans [Karolinska University Hospital Solna, Department of Radiology, Stockholm (Sweden); Jonsson, Cathrine [Karolinska University Hospital Solna, Department of Hospital Physics, Stockholm (Sweden)

    2012-11-15

    At {sup 18}F-2-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) examinations a high tracer uptake of the skeletal muscles is sometimes encountered which can lead to reduced uptake in pathological lesions. This was evaluated in retrospect in patients being recalled for a repeat examination after reducing the muscular uptake. Ten patients with increased muscular tracer uptake were examined with FDG PET/CT on two occasions with a mean of 6 days. All patients showed at least one pathological lesion with increased tracer uptake. The muscular uptake was reduced at the second examination by informing the patient to refrain from physical activity together with pretreatment with diazepam. The maximum standardized uptake value (SUV{sub max}) of the pathological lesion and SUV{sub mean} of certain skeletal muscles, liver, spleen, lungs, blood and certain bone marrow portions were calculated. In all patients, the muscular uptake was reduced to a normal level at visual evaluation as well as at comparison of SUVs with 25 consecutive clinical patients exhibiting a normal FDG distribution (p < 0.001). The mean lesion SUV{sub max} increased from 2.4 to 3.7 (54 %) between the examinations (p < 0.05). All reference tissues/organs showed a significant increase of SUV at the second examination. Relating lesion SUV{sub max} to the activity of any of the reference tissues/organs there was no significant difference between the studies. The distribution of FDG constitutes a relative mechanism. This must be especially considered at longitudinal examinations in the same patient at therapy evaluations. In examinations with a somehow distorted general distribution of the activity, it may be more relevant to relate the lesion activity to a reference tissue/organ than relying on SUV assessments. (orig.)

  2. Effects on Mechanical Properties of Recycled PET in Cement-Based Composites

    Directory of Open Access Journals (Sweden)

    Liliana Ávila Córdoba

    2013-01-01

    Full Text Available Concretes consisting of portland cement (OPC, silica sand, gravel, water, and recycled PET particles were developed. Specimens without PET particles were prepared for comparison. Curing times, PET particle sizes, and aggregate concentrations were varied. The compressive strength, compressive strain at yield point, and Young modulus were determined. Morphological and chemical compositions of recycled PET particles were seen in a scanning electron microscopy. Results show that smaller PET particle sizes in lower concentrations generate improvements on compressive strength and strain, and Young’s modulus decreases when the size of PET particles used was increased.

  3. Water Intake by Soil, Experiments for High School Students.

    Science.gov (United States)

    1969

    Presented are a variety of surface run-off experiments for high school students. The experiments are analogies to basic concepts about water intake, as related to water delivery, soil properties and management, floods, and conservation measures. The materials needed to perform the experiments are easily obtainable. The experiments are followed by…

  4. Decomposition of water into highly combustible hydroxyl gas used in ...

    African Journals Online (AJOL)

    The method proposed involves the decomposition of water into highly combustible hydroxyl gas via electrolysis, which is used in internal combustion engines of electrical generators for electricity generation. The by-product obtained from combustion of this gas is water vapour and oxygen to replenish the atmosphere.

  5. Feasibility of simultaneous PET/MR of the carotid artery: first clinical experience and comparison to PET/CT

    Science.gov (United States)

    Ripa, Rasmus S; Knudsen, Andreas; Hag, Anne Mette F; Lebech, Anne-Mette; Loft, Annika; Keller, Sune H; Hansen, Adam E; von Benzon, Eric; Højgaard, Liselotte; Kjær, Andreas

    2013-01-01

    The study aimed at comparing PET/MR to PET/CT for imaging the carotid arteries in patients with known increased risk of atherosclerosis. Six HIV-positive men underwent sequential PET/MR and PET/CT of the carotid arteries after injection of 400 MBq of 18F-FDG. PET/MR was performed a median of 131 min after injection. Subsequently,PET/CT was performed. Regions of interest (ROI) were drawn slice by slice to include the carotid arteries and standardized uptake values (SUV) were calculated from both datasets independently. Quantitative comparison of 18F-FDG uptake revealed a high congruence between PET data acquired using the PET/MR system compared to the PET/CT system. The mean difference for SUVmean was -0.18 (p PET/MR system. The 95% limits of agreement were -0.55 to 0.20 for SUVmean and -0.93 to 0.65 for SUVmax. The image quality of the PET/MR allowed for delineation of the carotid vessel wall. The correlations between 18F-FDG uptake from ROI including both vessel wall and vessel lumen to ROI including only the wall were strong (r = 0.98 for SUVmean and r = 1.00 for SUVmax) indicating that the luminal 18F-FDG content had minimal influence on the values. The study shows for the first time that simultaneous PET/MR of the carotid arteries is feasible in patients with increased risk of atherosclerosis. Quantification of 18F-FDG uptake correlated well between PET/MR and PET/CT despite difference in method of PET attenuation correction, reconstruction algorithm, and detector technology. PMID:23900769

  6. Inundation Mapping Tidal Surface - Mean Higher High Water

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data are a derived product of the NOAA VDatum tool and they extend the tool's Mean Higher High Water (MHHW) tidal datum conversion inland beyond its original...

  7. NOS CO-OPS Water Level Data, Verified, High Low

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset has verified (quality-controlled), daily, high low water level (tide) data from NOAA NOS Center for Operational Oceanographic Products and Services...

  8. PeneloPET, a Monte Carlo PET simulation tool based on PENELOPE: features and validation

    Energy Technology Data Exchange (ETDEWEB)

    Espana, S; Herraiz, J L; Vicente, E; Udias, J M [Grupo de Fisica Nuclear, Departmento de Fisica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid, Madrid (Spain); Vaquero, J J; Desco, M [Unidad de Medicina y CirugIa Experimental, Hospital General Universitario Gregorio Maranon, Madrid (Spain)], E-mail: jose@nuc2.fis.ucm.es

    2009-03-21

    Monte Carlo simulations play an important role in positron emission tomography (PET) imaging, as an essential tool for the research and development of new scanners and for advanced image reconstruction. PeneloPET, a PET-dedicated Monte Carlo tool, is presented and validated in this work. PeneloPET is based on PENELOPE, a Monte Carlo code for the simulation of the transport in matter of electrons, positrons and photons, with energies from a few hundred eV to 1 GeV. PENELOPE is robust, fast and very accurate, but it may be unfriendly to people not acquainted with the FORTRAN programming language. PeneloPET is an easy-to-use application which allows comprehensive simulations of PET systems within PENELOPE. Complex and realistic simulations can be set by modifying a few simple input text files. Different levels of output data are available for analysis, from sinogram and lines-of-response (LORs) histogramming to fully detailed list mode. These data can be further exploited with the preferred programming language, including ROOT. PeneloPET simulates PET systems based on crystal array blocks coupled to photodetectors and allows the user to define radioactive sources, detectors, shielding and other parts of the scanner. The acquisition chain is simulated in high level detail; for instance, the electronic processing can include pile-up rejection mechanisms and time stamping of events, if desired. This paper describes PeneloPET and shows the results of extensive validations and comparisons of simulations against real measurements from commercial acquisition systems. PeneloPET is being extensively employed to improve the image quality of commercial PET systems and for the development of new ones.

  9. Experimental evaluation of iterative reconstruction versus filtered back projection for 3D [O-15]water PET activation studies using statistical parametric mapping analysis.

    NARCIS (Netherlands)

    Mesina, C.T.; Boellaard, R.; Jongbloed, G.; van der Vaart, A.W.; Lammertsma, A.A.

    2003-01-01

    Iterative reconstructions are increasingly used for clinical PET studies owing to the better noise properties compared with filtered backprojection (FBP). The purpose of the present study was to compare ordered subsets expectation maximization (OSEM) iterative reconstruction with FBP as input for

  10. Sensory analysis of pet foods.

    Science.gov (United States)

    Koppel, Kadri

    2014-08-01

    Pet food palatability depends first and foremost on the pet and is related to the pet food sensory properties such as aroma, texture and flavor. Sensory analysis of pet foods may be conducted by humans via descriptive or hedonic analysis, pets via acceptance or preference tests, and through a number of instrumental analysis methods. Sensory analysis of pet foods provides additional information on reasons behind palatable and unpalatable foods as pets lack linguistic capabilities. Furthermore, sensory analysis may be combined with other types of information such as personality and environment factors to increase understanding of acceptable pet foods. Most pet food flavor research is proprietary and, thus, there are a limited number of publications available. Funding opportunities for pet food studies would increase research and publications and this would help raise public awareness of pet food related issues. This mini-review addresses current pet food sensory analysis literature and discusses future challenges and possibilities. © 2014 Society of Chemical Industry.

  11. Attenuation Effects of MR Headphones During Brain PET/MR Studies.

    Science.gov (United States)

    Ferguson, Aaron; McConathy, Jonathan; Su, Yi; Hewing, Debra; Laforest, Richard

    2014-06-01

    PET/MR offers potential advantages over PET/CT that are currently under investigation. One of the challenges of PET/MR is attenuation correction, as there is no simple correlation between MR signal intensity and the attenuation of 511-keV photons detected in PET. Currently, dedicated MR sequences are used to segment voxels into categories that are then assigned a predetermined attenuation coefficient. MR hardware such as the imaging table, coils, and headphones are also sources of attenuation. The purpose of this study was to evaluate the effect of MR-compatible headphones on average activity concentration measured with PET/MR. We also present a practical approach to correct for the attenuation effect of headphones using a CT-derived attenuation map. Phantom studies were performed using a 3-L cylindric phantom containing 55 MBq of (18)F-FDG and water. Images were acquired on a PET/MR device in 2 settings-one with the PET/MR headphones on and one with the headphones off. Phantom images were analyzed to compare activity concentration with headphones on and off. A high-resolution CT and (57)Co transmission scan was obtained to construct a PET attenuation map of the headphones. The resulting attenuation map was registered to the phantom data to evaluate the ability to correct for headphone attenuation. One human subject was scanned to evaluate the clinical impact of headphone attenuation and the accuracy of the proposed correction. Activity concentrations measured in the phantom were reduced by as much as 13.2% with headphones on compared with headphones off. Using the modified attenuation maps that account for attenuation from the headphones resulted in a decrease in the headphone attenuation effect from a maximum of 13.2% to 1.9%. Comparable attenuation effects were observed in the human brain and were similarly reduced with correction using the modified attenuation maps. MR-safe headphones were a source of attenuation on our PET/MR phantom and human studies

  12. Laboratory and cyclotron requirements for PET research

    Energy Technology Data Exchange (ETDEWEB)

    Schlyer, D.J.

    1993-06-01

    This report describes four types of PET facilities: Clinical PET with no radionuclide production; clinical PET with a small accelerator; clinical PET with research support; and research PET facilities. General facility considerations are also discussed.

  13. 18F Fluorocholine Dynamic Time-of-Flight PET/MR Imaging in Patients with Newly Diagnosed Intermediate- to High-Risk Prostate Cancer: Initial Clinical-Pathologic Comparisons.

    Science.gov (United States)

    Choi, Joon Young; Yang, Jaewon; Noworolski, Susan M; Behr, Spencer; Chang, Albert J; Simko, Jeffry P; Nguyen, Hao G; Carroll, Peter R; Kurhanewicz, John; Seo, Youngho

    2017-02-01

    Purpose To investigate the initial clinical value of fluorine 18 (18F) fluorocholine (FCH) dynamic positron emission tomography (PET)/magnetic resonance (MR) imaging by comparing its parameters with clinical-pathologic findings in patients with newly diagnosed intermediate- to high-risk prostate cancer (PCa) who plan to undergo radical prostatectomy. Materials and Methods The institutional review board approved the study protocol, and informed written consent was obtained from all subjects for this HIPAA-compliant study. Twelve men (mean age ± standard deviation, 61.7 years ± 8.4; range, 46-74 years) with untreated intermediate- to high-risk PCa characterized according to Cancer of the Prostate Risk Assessment (CAPRA) underwent preoperative FCH dynamic PET/MR imaging followed by radical prostatectomy between April and November 2015. PET/MR imaging parameters including average and maximum K1 (delivery rate constant) and standardized uptake values (SUVs) and Prostate Imaging Reporting and Data System (PI-RADS) version 2 scores were measured and compared with clinical-pathologic characteristics. For statistical analysis, the Spearman rank correlation and Mann-Whitney U tests were performed. Results Of the PET parameters, maximum SUV of primary tumors showed significant correlations with several clinical-pathologic parameters including serum prostate-specific antigen level (ρ = 0.71, P = .01), pathologic stage (ρ = 0.59, P = .043), and postsurgical CAPRA score (ρ = 0.72, P = .008). The overall PI-RADS score showed significant correlations with pathologic tumor volume (ρ = 0.81, P PET/MR imaging show good correlation with clinical-pathologic characteristics, such as postsurgical CAPRA score, which are related to prognosis in patients with newly diagnosed intermediate- to high-risk PCa. © RSNA, 2016 Online supplemental material is available for this article.

  14. Fat-constrained 18F-FDG PET reconstruction using Dixon MR imaging and the origin ensemble algorithm

    Science.gov (United States)

    Wülker, Christian; Heinzer, Susanne; Börnert, Peter; Renisch, Steffen; Prevrhal, Sven

    2015-03-01

    Combined PET/MR imaging allows to incorporate the high-resolution anatomical information delivered by MRI into the PET reconstruction algorithm for improvement of PET accuracy beyond standard corrections. We used the working hypothesis that glucose uptake in adipose tissue is low. Thus, our aim was to shift 18F-FDG PET signal into image regions with a low fat content. Dixon MR imaging can be used to generate fat-only images via the water/fat chemical shift difference. On the other hand, the Origin Ensemble (OE) algorithm, a novel Markov chain Monte Carlo method, allows to reconstruct PET data without the use of forward- and back projection operations. By adequate modifications to the Markov chain transition kernel, it is possible to include anatomical a priori knowledge into the OE algorithm. In this work, we used the OE algorithm to reconstruct PET data of a modified IEC/NEMA Body Phantom simulating body water/fat composition. Reconstruction was performed 1) natively, 2) informed with the Dixon MR fat image to down-weight 18F-FDG signal in fatty tissue compartments in favor of adjacent regions, and 3) informed with the fat image to up-weight 18F-FDG signal in fatty tissue compartments, for control purposes. Image intensity profiles confirmed the visibly improved contrast and reduced partial volume effect at water/fat interfaces. We observed a 17+/-2% increased SNR of hot lesions surrounded by fat, while image quality was almost completely retained in fat-free image regions. An additional in vivo experiment proved the applicability of the presented technique in practice, and again verified the beneficial impact of fat-constrained OE reconstruction on PET image quality.

  15. High prevalence of multidrug-tolerant bacteria and associated antimicrobial resistance genes isolated from ornamental fish and their carriage water.

    Science.gov (United States)

    Verner-Jeffreys, David W; Welch, Timothy J; Schwarz, Tamar; Pond, Michelle J; Woodward, Martin J; Haig, Sarah J; Rimmer, Georgina S E; Roberts, Edward; Morrison, Victoria; Baker-Austin, Craig

    2009-12-21

    Antimicrobials are used to directly control bacterial infections in pet (ornamental) fish and are routinely added to the water these fish are shipped in to suppress the growth of potential pathogens during transport. To assess the potential effects of this sustained selection pressure, 127 Aeromonas spp. isolated from warm and cold water ornamental fish species were screened for tolerance to 34 antimicrobials. Representative isolates were also examined for the presence of 54 resistance genes by a combination of miniaturized microarray and conventional PCR. Forty-seven of 94 Aeromonas spp. isolates recovered from tropical ornamental fish and their carriage water were tolerant to > or =15 antibiotics, representing seven or more different classes of antimicrobial. The quinolone and fluoroquinolone resistance gene, qnrS2, was detected at high frequency (37% tested recent isolates were positive by PCR). Class 1 integrons, IncA/C broad host range plasmids and a range of other antibiotic resistance genes, including floR, bla(TEM-1), tet(A), tet(D), tet(E), qacE2, sul1, and a number of different dihydrofolate reductase and aminoglycoside transferase coding genes were also detected in carriage water samples and bacterial isolates. These data suggest that ornamental fish and their carriage water act as a reservoir for both multi-resistant bacteria and resistance genes.

  16. Glycoalkaloid content in pet food by UPLC-tandem mass spectrometry.

    Science.gov (United States)

    Sheridan, Robert S; Kemnah, Jennifer L

    2010-11-01

    The glycoalkaloid content of pet food containing potatoes is investigated using a liquid-liquid solvent extraction followed by analysis by ultra-high pressure liquid chromatography tandem mass spectrometry (UPLC-MS-MS). Pet food samples are homogenized and extracted with a solution of 50:50 (v/v) acetonitrile-deionized water containing 5% acetic acid. Following vortexing and centrifugation, 3 mL of the supernatant is filtered and diluted in deionized water. The extract is injected onto a reverse phase C18 UPLC column with an initial mobile phase composed of 0.15% acetic acid in water (A) and 0.15% acetic acid in methanol (B) in a ratio of 70:30, respectively. The mobile phase reaches a final concentration of 15% A and 85% B over 10 min, at which point it is returned to the initial conditions. α-Solanine is measured by monitoring transitions m/z = 868.50 → 398.40 and 868.50 → 722.50, while α-chaconine is measure by monitoring transitions m/z = 852.60 → 97.80 and 852.60 → 706.50. Each analyte is measured and combined to determine total glycoalkaloid content (TGA). The results of the analysis of 52 pet food samples indicate both glycoalkaloids are present in all samples and two pet foods were found to contain > 100 μg/g total glycoalkaloid.

  17. An iterative technique to segment PET lesions using a Monte Carlo based mathematical model.

    Science.gov (United States)

    Nehmeh, S A; El-Zeftawy, H; Greco, C; Schwartz, J; Erdi, Y E; Kirov, A; Schmidtlein, C R; Gyau, A B; Larson, S M; Humm, J L

    2009-10-01

    The need for an accurate lesion segmentation tool in 18FDG PET is a prerequisite for the estimation of lesion response to therapy, for radionuclide dosimetry, and for the application of 18FDG PET to radiotherapy planning. In this work, the authors have developed an iterative method based on a mathematical fit deduced from Monte Carlo simulations to estimate tumor segmentation thresholds. The GATE software, a GEANT4 based Monte Carlo tool, was used to model the GE Advance PET scanner geometry. Spheres ranging between 1 and 6 cm in diameters were simulated in a 10 cm high and 11 cm in diameter cylinder. The spheres were filled with water-equivalent density and simulated in both water and lung equivalent background. The simulations were performed with an infinite, 8/1, and 4/1 target-to-background ratio (T/B). A mathematical fit describing the correlation between the lesion volume and the corresponding optimum threshold value was then deduced through analysis of the reconstructed images. An iterative method, based on this mathematical fit, was developed to determine the optimum threshold value. The effects of the lesion volume and T/B on the threshold value were investigated. This method was evaluated experimentally using the NEMA NU2-2001 IEC phantom, the ACNP cardiac phantom, a randomly deformed aluminum can, and a spheroidal shape phantom implemented artificially in the lung, liver, and brain of patient PET images. Clinically, the algorithm was evaluated in six lesions from five patients. Clinical results were compared to CT volumes. This mathematical fit predicts an existing relationship between the PET lesion size and the percent of maximum activity concentration within the target volume (or threshold). It also showed a dependence of the threshold value on the T/B, which could be eliminated by background subtraction. In the phantom studies, the volumes of the segmented PET targets in the PET images were within 10% of the nominal ones. Clinically, the PET target

  18. An update on the role of PET/CT and PET/MRI in ovarian cancer

    Energy Technology Data Exchange (ETDEWEB)

    Khiewvan, Benjapa [Hospital of the University of Pennsylvania, Department of Radiology, Philadelphia, PA (United States); Mahidol University, Division of Nuclear Medicine, Department of Radiology, Faculty of Medicine Siriraj Hospital, Bangkok (Thailand); Torigian, Drew A.; Emamzadehfard, Sahra; Paydary, Koosha; Salavati, Ali; Houshmand, Sina; Werner, Thomas J.; Alavi, Abass [Hospital of the University of Pennsylvania, Department of Radiology, Philadelphia, PA (United States)

    2017-06-15

    This review article summarizes the role of PET/CT and PET/MRI in ovarian cancer. With regard to the diagnosis of ovarian cancer, the presence of FDG uptake within the ovary of a postmenopausal woman raises the concern for ovarian cancer. Multiple studies show that FDG PET/CT can detect lymph node and distant metastasis in ovarian cancer with high accuracy and may, therefore, alter the management to obtain better clinical outcomes. Although PET/CT staging is superior for N and M staging of ovarian cancer, its role is limited for T staging. Additionally, FDG PET/CT is of great benefit in evaluating treatment response and has prognostic value in patients with ovarian cancer. FDG PET/CT also has value to detect recurrent disease, particularly in patients with elevated serum CA-125 levels and negative or inconclusive conventional imaging test results. PET/MRI may beneficial for tumor staging because MRI has higher soft tissue contrast and no ionizing radiation exposure compared to CT. Some non-FDG PET radiotracers such as {sup 18}F-fluorothymidine (FLT) or {sup 11}C-methionine (MET) have been studied in preclinical and clinical studies as well and may play a role in the evaluation of patients with ovarian cancer. (orig.)

  19. Nutritional Sustainability of Pet Foods12

    Science.gov (United States)

    Swanson, Kelly S.; Carter, Rebecca A.; Yount, Tracy P.; Aretz, Jan; Buff, Preston R.

    2013-01-01

    Sustainable practices meet the needs of the present without compromising the ability of future generations to meet their needs. Applying these concepts to food and feed production, nutritional sustainability is the ability of a food system to provide sufficient energy and essential nutrients required to maintain good health in a population without compromising the ability of future generations to meet their nutritional needs. Ecological, social, and economic aspects must be balanced to support the sustainability of the overall food system. The nutritional sustainability of a food system can be influenced by several factors, including the ingredient selection, nutrient composition, digestibility, and consumption rates of a diet. Carbon and water footprints vary greatly among plant- and animal-based ingredients, production strategy, and geographical location. Because the pet food industry is based largely on by-products and is tightly interlinked with livestock production and the human food system, however, it is quite unique with regard to sustainability. Often based on consumer demand rather than nutritional requirements, many commercial pet foods are formulated to provide nutrients in excess of current minimum recommendations, use ingredients that compete directly with the human food system, or are overconsumed by pets, resulting in food wastage and obesity. Pet food professionals have the opportunity to address these challenges and influence the sustainability of pet ownership through product design, manufacturing processes, public education, and policy change. A coordinated effort across the industry that includes ingredient buyers, formulators, and nutritionists may result in a more sustainable pet food system. PMID:23493530

  20. Highly Efficient Multiple-Anchored Fluorescent Probe for the Detection of Aniline Vapor Based on Synergistic Effect: Chemical Reaction and PET.

    Science.gov (United States)

    Jiao, Zinuo; Zhang, Yu; Xu, Wei; Zhang, Xiangtao; Jiang, Haibo; Wu, Pengcheng; Fu, Yanyan; He, Qingguo; Cao, Huimin; Cheng, Jiangong

    2017-05-26

    A multiple-anchored fluorescent probe ((((hexane-1,6-diylbis(2,7-bis(4-formyl)-phenyl)-9H-fluorine-9,9-diyl))-bis(hexane-6,1-diyl))-bis(9H-carbazole-9,3,6-triyl))-tetrakis(benzene-4,1-diyl))-tetraformyl-(8FP-2F) with eight aldehyde groups was designed and synthesized. The molecule has four branches and highly twisted structure. Furthermore, it tends to self-assemble into nanospheres, which is beneficial for gaseous analyte penetration and high fluorescence quantum efficiency. Among gaseous analytes, detection of aniline vapor is extraordinarily important in the control of environmental issues and human diseases. Herein, 8FP-2F was introduced to detect aniline vapor with distinguished sensitivity and selectivity via simple Schiff base reaction at room temperature. After exposure to saturate aniline vapor, the 89% fluorescence of 8FP-2F was quenched in 50 s and the detection limit was as low as 3 ppb. Further study showed the suitable HOMO/LUMO energy levels and matched orbital symmetry between probe and aniline molecules ensured chemical reaction and PET process work together. The synergistic effect resulted in a significant sensing performance and fluorescence quenching toward aniline vapor. Moreover, the multiple active sites structure of 8FP-2F means it could be applied for constructing many interesting structures and highly efficient organic optoelectronic functional materials.

  1. Highly water-soluble multi-walled carbon nanotubes amine-functionalized by supercritical water oxidation.

    Science.gov (United States)

    Chun, Kyoung-Yong; Moon, In-Kyu; Han, Joo-Hee; Do, Seung-Hoe; Lee, Jin-Seo; Jeon, Seong-Yun

    2013-11-07

    Multi-walled carbon nanotubes (MWNTs) have been amine-functionalized by eco-friendly supercritical water oxidation. The facilely functionalized MWNTs have high solubility (~84 mg L(-1)) in water and 78% transmittance at 30-fold dilution. The Tyndall effect is also shown for several liquids.

  2. Water Stage Forecasting in Tidal streams during High Water Using EEMD

    Science.gov (United States)

    Chen, Yen-Chang; Kao, Su-Pai; Su, Pei-Yi

    2017-04-01

    There are so many factors may affect the water stages in tidal streams. Not only the ocean wave but also the stream flow affects the water stage in a tidal stream. During high water, two of the most important factors affecting water stages in tidal streams are flood and tide. However the hydrological processes in tidal streams during high water are nonlinear and nonstationary. Generally the conventional methods used for forecasting water stages in tidal streams are very complicated. It explains the accurately forecasting water stages, especially during high water, in tidal streams is always a difficult task. The study makes used of Ensemble Empirical Model Decomposition (EEMD) to analyze the water stages in tidal streams. One of the advantages of the EEMD is it can be used to analyze the nonlinear and nonstationary data. The EEMD divides the water stage into several intrinsic mode functions (IMFs) and a residual; meanwhile, the physical meaning still remains during the process. By comparing the IMF frequency with tidal frequency, it is possible to identify if the IMF is affected by tides. Then the IMFs is separated into two groups, affected by tide or not by tide. The IMFs in each group are assembled to become a factor. Therefore the water stages in tidal streams are only affected by two factors, tidal factor and flood factor. Finally the regression analysis is used to establish the relationship between the factors of the gaging stations in the tidal stream. The available data during 15 typhoon periods of the Tanshui River whose downstream reach is in estuary area is used to illustrate the accuracy and reliability of the proposed method. The results show that the simple but reliable method is capable of forecasting water stages in tidal streams.

  3. Comparison of integrated whole-body [{sup 11}C]choline PET/MR with PET/CT in patients with prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Souvatzoglou, Michael; Takei, Toshiki; Fuerst, Sebastian; Gaertner, Florian; Drzezga, Alexander; Ziegler, Sibylle; Nekolla, Stephan G.; Schwaiger, Markus; Beer, Ambros J. [Technische Universitaet Muenchen, Department of Nuclear Medicine, Munich (Germany); Eiber, Matthias; Rummeny, Ernst J. [Technische Universitaet Muenchen, Department of Radiology, Munich (Germany); Maurer, Tobias [Technische Universitaet Muenchen, Department of Urology, Munich (Germany); Geinitz, Hans [Technische Universitaet Muenchen, Department of Radiation Oncology, Munich (Germany)

    2013-10-15

    To evaluate the performance of conventional [{sup 11}C]choline PET/CT in comparison to that of simultaneous whole-body PET/MR. The study population comprised 32 patients with prostate cancer who underwent a single-injection dual-imaging protocol with PET/CT and subsequent PET/MR. PET/CT scans were performed applying standard clinical protocols (5 min after injection of 793 {+-} 69 MBq [{sup 11}C]choline, 3 min per bed position, intravenous contrast agent). Subsequently (52 {+-} 15 min after injection) PET/MR was performed (4 min per bed position). PET images were reconstructed iteratively (OSEM 3D), scatter and attenuation correction of emission data and regional allocation of [{sup 11}C]choline foci were performed using CT data for PET/CT and segmented Dixon MR, T1 and T2 sequences for PET/MR. Image quality of the respective PET scans and PET alignment with the respective morphological imaging modality were compared using a four point scale (0-3). Furthermore, number, location and conspicuity of the detected lesions were evaluated. SUVs for suspicious lesions, lung, liver, spleen, vertebral bone and muscle were compared. Overall 80 lesions were scored visually in 29 of the 32 patients. There was no significant difference between the two PET scans concerning number or conspicuity of the detected lesions (p not significant). PET/MR with T1 and T2 sequences performed better than PET/CT in anatomical allocation of lesions (2.87 {+-} 0.3 vs. 2.72 {+-} 0.5; p = 0.005). The quality of PET/CT images (2.97 {+-} 0.2) was better than that of the respective PET scan of the PET/MR (2.69 {+-} 0.5; p = 0.007). Overall the maximum and mean lesional SUVs exhibited high correlations between PET/CT and PET/MR ({rho} = 0.87 and {rho} = 0.86, respectively; both p < 0.001). Despite a substantially later imaging time-point, the performance of simultaneous PET/MR was comparable to that of PET/CT in detecting lesions with increased [{sup 11}C]choline uptake in patients with prostate

  4. High frequency, realtime measurements of stable isotopes in liquid water

    Science.gov (United States)

    Weiler, M.; Herbstritt, B.; Gralher, B.

    2012-04-01

    We developed a method to measure in-situ the isotopic composition of liquid water with minimal supervision and, most important, with a temporal resolution of less than a minute. For this purpose a off-the-shelf microporous hydrophobic membrane contactor for under 200€ was combined with an isotope laser spectrometer (Picarro). The contactor, originally designed for degassing liquids, was used with nitrogen as carrier gas in order to transform a small fraction of liquid water to water vapor. The generated water vapor was then analyzed continuously by the isotope laser spectrometer. To prove the membrane's applicability we determined the specific isotope fractionation factor for the phase change through the contactor's membrane for a common temperature range and with different waters of known isotopic compositions. This fractionation factor is then used to derive the liquid water isotope ratio from the measured water vapor isotope ratios and the measured temperature at the phase change. The system was compared for breakthrough curves of isotopically enriched water and the isotope values corresponded very well with those of liquid water samples taken simultaneously and analyzed with a conventional method (CRDS). The introduced method supersedes taking liquid samples and employs only relative cheap and readily available components. This makes it a relatively inexpensive, fast, user-friendly and easily reproducible method. It can be applied in both the field and laboratory wherever a water vapor isotope analyzer can be run and whenever real-time isotope data of liquid water are required at high temporal resolution with the same accuracy as collecting individual water samples.

  5. 18F-FDG-PET/CT in the Staging and Management of Melanoma: A Prospective Multicenter Ontario PET Registry Study.

    Science.gov (United States)

    Singnurkar, Amit; Wang, Jonathan; Joshua, Anthony M; Langer, Deanna L; Metser, Ur

    2016-03-01

    The Ontario PET Registry was established to provide evidence on the clinical impact of 18-FDG-PET/CT (PET) imaging to inform Ontario Health Insurance Plan funding decisions. The melanoma registry assessed the use of melanoma staging by PET in advanced or high-risk melanoma as a useful adjunct to clinical and standard radiologic investigation. Between January 2011 and July 2013, approximately 319 consecutive patients with potentially resectable localized high-risk melanoma or recurrent disease under consideration for metastasectomy underwent PET imaging for staging across 9 institutions in Ontario. Pre-PET stage information was provided by the referring clinician and compared with post-PET stage. The ability of PET to reclassify disease from M0 to M1 status was assessed. The registry data were then linked to provincial administrative databases using deidentified health insurance numbers to determine PET stage-based rates of systemic therapy, radiotherapy, and surgery. There was a significant increase in stage to M1 status after PET in 56 of 319 patients (17.6%) (P < 0.0001). There was no significant relationship between upstaging with PET and the proportion of patients receiving radiation therapy (P = 0.066) or systemic therapy (P = 0.072). There was a significant relationship between upstaging with PET and the proportion of patients undergoing surgical resection of metastases distant to the primary melanoma site (P = 0.034). This prospective, multicenter registry of high-risk or advanced melanoma found that PET significantly upstages patients and impacts surgical management.

  6. Diagnostic accuracy of {sup 18}F-FDG-PET and PET/CT in patients with Ewing sarcoma family tumours: a systematic review and a meta-analysis

    Energy Technology Data Exchange (ETDEWEB)

    Treglia, Giorgio [Institute of Nuclear Medicine, Catholic University of the Sacred Heart, Department of Bioimaging and Radiological Sciences, Rome (Italy); Institute of Nuclear Medicine, Positron Emission Tomography Centre, Catholic University of the Sacred Heart, Department of Bioimaging and Radiological Sciences, Rome (Italy); Salsano, Marco; Stefanelli, Antonella; Mattoli, Maria Vittoria; Giordano, Alessandro [Institute of Nuclear Medicine, Catholic University of the Sacred Heart, Department of Bioimaging and Radiological Sciences, Rome (Italy); Bonomo, Lorenzo [Institute of Radiology, Catholic University of the Sacred Heart, Department of Bioimaging and Radiological Sciences, Rome (Italy)

    2012-03-15

    To systematically review and meta-analyse literature data on the diagnostic performance of fluorine-18-fluorodeoxyglucose (FDG) positron emission tomography (PET) and positron emission tomography/computed tomography (PET/CT) in patients with Ewing sarcoma family tumours (ESFT). PubMed/MEDLINE, Embase and Scopus databases were searched for articles that evaluated FDG-PET and PET/CT in patients with ESFT from inception to 31 May 2011. Studies that fulfilled the three following criteria were included in the systematic review: FDG-PET or PET/CT performed in patients with ESFT; articles about the diagnostic accuracy of FDG-PET and PET/CT; sample size of at least 10 patients with ESFT were included. Studies in which there were sufficient data to reassess sensitivity and specificity of FDG-PET or PET/CT in ESFT were included in the meta-analysis, excluding duplicate publications. Finally, pooled sensitivity, pooled specificity and area under the receiver operating characteristic (ROC) curve of FDG-PET or PET/CT in ESFT were calculated. We found 13 studies comprising a total of 342 patients with ESFT. The main findings of the studies included are presented. The meta-analysis of five selected studies provided these results about FDG-PET and PET/CT in ESFT: pooled sensitivity: 96% (95% confidence interval [CI] 91-99%); pooled specificity: 92% (95% CI 87-96%); area under the ROC curve: 0.97. With regard to the staging and restaging of patients with ESFT, the sensitivity, specificity and accuracy of FDG-PET and PET/CT are high; the combination of FDG-PET or PET/CT with conventional imaging is a valuable tool for the staging and restaging of ESFT and has a relevant impact on the treatment strategy plan. (orig.)

  7. Separation and recycling of cotton from cotton/PET blends by depolymerization of PET catalyzed by bases and ionic liquids

    NARCIS (Netherlands)

    Bouwhuis, G.H. (Gerrit); Brinks, G.J. (Ger); Groeneveld, R.A.J. (Richard); Oelerich, J. (Jens)

    2014-01-01

    The recycling of post consumer cotton textile waste is highly requested, due to the high environmental impact of cotton production. Often cotton is mixed in blends with polyethylene terephthalate (PET). For the generation of high value products from recycled cotton, it essential that PET is

  8. My Pet Rock

    Science.gov (United States)

    Lark, Adam; Kramp, Robyne; Nurnberger-Haag, Julie

    2008-01-01

    Many teachers and students have experienced the classic pet rock experiment in conjunction with a geology unit. A teacher has students bring in a "pet" rock found outside of school, and the students run geologic tests on the rock. The tests include determining relative hardness using Mohs scale, checking for magnetization, and assessing luster.…

  9. High-resolution subsurface water-ice distributions on Mars.

    Science.gov (United States)

    Bandfield, Joshua L

    2007-05-03

    Theoretical models indicate that water ice is stable in the shallow subsurface (depths of Mars at high latitudes. These models have been mainly supported by the observed presence of large concentrations of hydrogen detected by the Gamma Ray Spectrometer suite of instruments on the Mars Odyssey spacecraft. The models and measurements are consistent with a water-ice table that steadily increases in depth with decreasing latitude. More detailed modelling has predicted that the depth at which water ice is stable can be highly variable, owing to local surface heterogeneities such as rocks and slopes, and the thermal inertia of the ground cover. Measurements have, however, been limited to the footprint (several hundred kilometres) of the Gamma Ray Spectrometer suite, preventing the observations from documenting more detailed water-ice distributions. Here I show that by observing the seasonal temperature response of the martian surface with the Thermal Emission Imaging System on the Mars Odyssey spacecraft, it is possible to observe such heterogeneities at subkilometre scale. These observations show significant regional and local water-ice depth variability, and, in some cases, support distributions in the subsurface predicted by atmospheric exchange and vapour diffusion models. The presence of water ice where it follows the depth of stability under current climatic conditions implies an active martian water cycle that responds to orbit-driven climate cycles. Several regions also have apparent deviations from the theoretical stability level, indicating that additional factors influence the ice-table depth. The high-resolution measurements show that the depth to the water-ice table is highly variable within the potential Phoenix spacecraft landing ellipses, and is likely to be variable at scales that may be sampled by the spacecraft.

  10. Autism spectrum disorder and pet therapy.

    Science.gov (United States)

    Siewertsen, Caitlin M; French, Emma D; Teramoto, Masaru

    2015-01-01

    Autism Spectrum Disorder (ASD) encompasses a wide range of social and mental afflictions that are difficult to treat. Due to a lack of established treatments for ASD, alternative therapies have been the primary form of intervention. One of these alternatives is pet therapy, a field that has experienced growing interest and has recently accumulated studies that investigate its efficacy. This article reviews and summarizes that effectiveness as well as the findings and limitations associated with pet therapy for ASD. The majority of research on ASD and pet therapy has examined children and has primarily used dogs and horses for therapy. Studies have shown positive effects for the therapy, including high satisfaction rates among the participants' families. Major limitations of studies in the current literature include the lack of control groups and small sample sizes. Future research should incorporate better study designs and large samples to validate pet therapy as an appropriate treatment for ASD.

  11. FDG PET/CT in cancer

    DEFF Research Database (Denmark)

    Petersen, Henrik; Holdgaard, Paw Christian; Madsen, Poul Henning

    2016-01-01

    use of PET/CT in the RSD with these recommendations. This article summarizes the results. METHODS: A Work Group appointed a professional Subgroup which made Clinician Groups conduct literature reviews on six selected cancers responsible for 5,768 (62.6 %) of 9,213 PET/CT scans in the RSD in 2012......-recommendable" indications, respectively. RESULTS: Of 11,729 citations, 1,729 were considered for review, and 204 were included. The evidence suggested usefulness of PET/CT in lung, lymphoma, melanoma, head and neck, and colorectal cancers, whereas evidence was sparse in gynaecological cancers. The agreement between actual...... use of PET/CT and literature-based recommendations was high in the first five mentioned cancers in that 96.2 % of scans were made for grade A or B indications versus only 22.2 % in gynaecological cancers. CONCLUSION: Evidence-based usefulness was reported in five of six selected cancers; evidence...

  12. Water Impacts of High Solar PV Electricity Penetration

    Energy Technology Data Exchange (ETDEWEB)

    Macknick, Jordan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Cohen, Stuart [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2015-09-01

    This analysis provides a detailed national and regional description of the water-related impacts and constraints of high solar electricity penetration scenarios in the U.S. in 2030 and 2050. A modified version of the Regional Energy Deployment System (ReEDS) model that incorporates water resource availability and costs as a constraint in each of its 134 Balancing Area (BA) regions was utilized to explore national and regional differences in water use impacts and solar deployment locations under different solar energy cost and water availability scenarios (Macknick et al. 2015). Water resource availability and cost data are from recently completed research at Sandia National Laboratories (Tidwell et al. 2013a). Scenarios analyzed include two business-as-usual solar energy cost cases, one with and one without considering available water resources, and four solar energy cost cases that meet the SunShot cost goals (i.e., $1/watt for utility-scale PV systems), with varying levels of water availability restrictions. This analysis provides insight into the role solar energy technologies have in the broader electricity sector under scenarios of water constraints.

  13. [F(18)]-fluoroethylcholine combined in-line PET-CT scan for detection of lymph-node metastasis in high risk prostate cancer patients prior to radical prostatectomy: Preliminary results from a prospective histology-based study.

    Science.gov (United States)

    Steuber, T; Schlomm, T; Heinzer, H; Zacharias, M; Ahyai, S; Chun, K F; Haese, A; Klutmann, S; Köllermann, J; Sauter, G; Mester, J; Mikecz, P; Fisch, M; Huland, H; Graefen, M; Salomon, G

    2010-01-01

    To evaluate the diagnostic potential of PET/CT using ([F(18)]fluorethylcholine (FEC) for lymph node (LN) staging in high risk prostate cancer (PCa) patients prior to radical prostatectomy (RP). Twenty patients with localised PCa and > or =20% LN risk according to a published nomogram were prospectively enrolled. FEC PET/CT was done minimum 14 d after prostate biopsy. Afterwards, open RP and extended pelvic LN dissection (ePLND) were performed. Clinical stage, Prostate Specific Antigen (PSA) and biopsy Gleason Grading were assessed and histopathological evaluation of the RP-specimens and dissected LN has been performed. The results from PET/CT were compared with LN metastasis according to their anatomical site. Overall, 285 LN have been removed with a mean number of 15 nodes per patient (7-26). Of the 20 patients, 9 men were LN positive (45%), which corresponds to 31 positive LN with a mean size of 7 mm (0.8-12 mm). Dissection of the obturator fossa, external iliac artery/vein and internal iliac artery/vein revealed 36%, 48% and 16% of positive LN, respectively. FEC PET/CT did not detect one single positive LN, thus was false-negative in 31 metastasis and true negative in 254 LN. Based on our results which confirmed experience from the previous studies, FEC PET/CT scan did not prove to be useful for LN staging in localised PCa prior to treatment and should thus not be applied if clinically occult metastatic disease is suspected. Copyright 2009 Elsevier Ltd. All rights reserved.

  14. Healthy pets, healthy people.

    Science.gov (United States)

    Wong, S K; Feinstein, L H; Heidmann, P

    1999-08-01

    Zoonoses, diseases that can be transmitted from animals to humans, can pose serious health risks to immunocompromised people. Although pets can carry zoonoses, owning and caring for animals can benefit human health. Information exists about preventing transmission of zoonoses, but not all physicians and veterinarians provide adequate and accurate information to immunocompromised pet owners. This disease prevention/health promotion project provides physicians and veterinarians with information, created specifically to share with patients and clients, about the health risks and benefits of pet ownership. Further, "Healthy Pets, Healthy People" encourages communication between veterinarians, physicians, clients, and patients and can serve as a model program for a nation-wide effort to aid health professionals in making recommendations about pet ownership for immunocompromised people.

  15. Usage of Recycled Pet

    Directory of Open Access Journals (Sweden)

    A. Ebru Tayyar

    2010-01-01

    Full Text Available The increasing industrialization, urbanization and the technological development have caused to increase depletion of the natural resources and environmental pollution's problem. Especially, for the countries which have not enough space recycling of the waste eliminating waste on regular basis or decreasing the amount and volume of waste have provided the important advantages. There are lots of studies and projects to develop both protect resources and prevent environmental pollution. PET bottles are commonly used in beverage industry and can be reused after physical and chemical recycling processes. Usage areas of recycled PET have been developed rapidly. Although recycled PET is used in plastic industry, composite industry also provides usage alternatives of recycled PET. Textile is a suitable sector for recycling of some plastics made of polymers too. In this study, the recycling technologies and applications of waste PET bottles have been investigated and scientific works in this area have been summarized.

  16. Water Containment Systems for Testing High-Speed Flywheels

    Science.gov (United States)

    Trase, Larry; Thompson, Dennis

    2006-01-01

    Water-filled containers are used as building blocks in a new generation of containment systems for testing high-speed flywheels. Such containment systems are needed to ensure safety by trapping high-speed debris in the event of centrifugal breakup or bearing failure. Traditional containment systems for testing flywheels consist mainly of thick steel rings. The effectiveness of this approach to shielding against high-speed debris was demonstrated in a series of tests.

  17. Tunable C2N Membrane for High Efficient Water Desalination

    Science.gov (United States)

    Yang, Yanmei; Li, Weifeng; Zhou, Hongcai; Zhang, Xiaoming; Zhao, Mingwen

    2016-01-01

    Water scarcity represents one of the most serious global problems of our time and challenges the advancements in desalination techniques. Although water-filtering architectures based on graphene have greatly advanced the approach to high performance desalination membranes, the controlled-generation of nanopores with particular diameter is tricky and has stunted its wide applications. Here, through molecular dynamic simulations and first-principles calculations, we propose that the recently reported graphene-like carbon nitride (g-C2N) monolayer can serve as high efficient filters for water desalination. Taking the advantages of the intrisic nanoporous structure and excellent mechanical properties of g-C2N, high water transparency and strong salt filtering capability have been demonstrated in our simulations. More importantly, the “open” and “closed” states of the g-C2N filter can be precisely regulated by tensile strain. It is found that the water permeability of g-C2N is significantly higher than that reported for graphene filters by almost one order of magnitude. In the light of the abundant family of graphene-like carbon nitride monolayered materials, our results thus offer a promising approach to the design of high efficient filteration architectures. PMID:27384666

  18. PET-based geometrical calibration of a pinhole SPECT add-on for an animal PET scanner.

    Science.gov (United States)

    Deng, Xiao; Beaudoin, Jean-François; Cadorette, Jules; Naaman, Charles; Lecomte, Roger; Yao, Rutao

    2013-04-07

    We developed SPECT imaging capability on an animal PET scanner to provide a cost effective option for animal SPECT imaging. The SPECT add-on sub-system was enabled by mechanically integrating a multiple-pinhole collimator in the PET detector ring. This study introduces a method to calibrate the geometrical parameters of the SPECT add-on using the PET imaging capability of the scanner. The proposed PET imaging-based calibration method consists of two steps: (1) paint the pinhole apertures of the collimator with a positron emitting radioactive solution; and (2) image the collimator inside the scanner in PET mode. The geometrical parameters of the multi-pinhole SPECT add-on can then be derived directly from a set of PET images by simple linear calculation and used in defining the SPECT system. The method was compared to our implementation of a SPECT calibration approach with model-based fitting of SPECT projection data. The procedure for carrying out the PET imaging-based calibration method is simpler and faster than that of our implementation of the SPECT model-based calibration method. Since it does not require model fitting, the uniqueness of the calibration result is warranted. Better quality SPECT images were reconstructed using the PET-derived calibration parameters rather than our implementation of the SPECT model-based calibration parameters. We conclude that the proposed PET imaging-based calibration method provides a highly effective means for enabling SPECT imaging on a PET scanner.

  19. Ehenge: marginalized soil with high water use efficiency

    Science.gov (United States)

    Prudat, Brice; Bloemertz, Lena; Kuhn, Nikolaus J.

    2015-04-01

    Ehenge is a soil that has been described by the communities of North-Central Namibia during different studies. Farmers consider this soil as nutrient-poor with a deep loose sand layer over a hardpan, called olumha. Despite its low nutrient content, this soil is usually cultivated because it holds water for a longer period than some more nutrient-rich soils. This characteristic is an advantage during growing season with scarce rains. It has been described so far as a (hypoluvic hyperalbic) Arenosol. The sequence of characteristic horizons is as follows: sandy A and E; thin accumulation horizon Bt on top of a Bg horizon. The latter is important for water storage during dry periods (as shown by water soil monitoring data). Management practices for this soil type are very different from other Arenosols, because the water dynamics are very specific, with high percolation rates combined with a high risk of waterlogging. The evolution of agriculture in North-Central Namibia will determine the future use and preservation of these soils, as the presence of hardpan is considered to be a limiting factor for agricultural development. The author demonstrates that this soil has a large potential for agricultural water use efficiency, in an area with very limited water resources and that might face longer dry period as an effect of climate change.

  20. Effect of MR contrast agents on quantitative accuracy of PET in combined whole-body PET/MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Lois, Cristina [University of Santiago de Compostela, Department of Particle Physics, Santiago de Compostela (Spain); Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela (Spain); Imaging Science Institute, Tuebingen (Germany); Bezrukov, Ilja [Eberhard Karls University, Laboratory for Preclinical Imaging and Imaging Technology of the Werner Siemens Foundation, Department of Preclinical Imaging and Radiopharmacy, Tuebingen (Germany); Max Plank Institute for Intelligent Systems, Department of Empirical Inference, Tuebingen (Germany); Schmidt, Holger [Eberhard Karls University, Laboratory for Preclinical Imaging and Imaging Technology of the Werner Siemens Foundation, Department of Preclinical Imaging and Radiopharmacy, Tuebingen (Germany); Eberhard Karls University, Diagnostic and Interventional Radiology, Department of Radiology, Tuebingen (Germany); Schwenzer, Nina; Werner, Matthias K. [Eberhard Karls University, Diagnostic and Interventional Radiology, Department of Radiology, Tuebingen (Germany); Kupferschlaeger, Juergen [Eberhard Karls University, Nuclear Medicine, Department of Radiology, Tuebingen (Germany); Beyer, Thomas [Imaging Science Institute, Tuebingen (Germany); cmi-experts GmbH, Zuerich (Switzerland)

    2012-11-15

    Clinical PET/MR acquisition protocols entail the use of MR contrast agents (MRCA) that could potentially affect PET quantification following MR-based attenuation correction (AC). We assessed the effect of oral and intravenous (IV) MRCA on PET quantification in PET/MR imaging. We employed two MRCA: Lumirem {sup registered} (oral) and Gadovist {sup registered} (IV). First, we determined their reference PET attenuation values using a PET transmission scan (ECAT-EXACT HR+, Siemens) and a CT scan (PET/CT Biograph 16 HI-REZ, Siemens). Second, we evaluated the attenuation of PET signals in the presence of MRCA. Phantoms were filled with clinically relevant concentrations of MRCA in a background of water and {sup 18}F-fluoride, and imaged using a PET/CT scanner (Biograph 16 HI-REZ, Siemens) and a PET/MR scanner (Biograph mMR, Siemens). Third, we investigated the effect of clinically relevant volumes of MRCA on MR-based AC using human pilot data: a patient study employing Gadovist {sup registered} (IV) and a volunteer study employing two different oral MRCA (Lumirem {sup registered} and pineapple juice). MR-based attenuation maps were calculated following Dixon-based fat-water segmentation and an external atlas-based and pattern recognition (AT and PR) algorithm. IV and oral MRCA in clinically relevant concentrations were found to have PET attenuation values similar to those of water. The phantom experiments showed that under clinical conditions IV and oral MRCA did not yield additional attenuation of PET emission signals. Patient scans showed that PET attenuation maps are not biased after the administration of IV MRCA but may be biased, however, after ingestion of iron oxide-based oral MRCA when segmentation-based AC algorithms are used. Alternative AC algorithms, such as AT and PR, or alternative oral contrast agents, such as pineapple juice, can yield unbiased attenuation maps. In clinical PET/MR scenarios MRCA are not expected to lead to markedly increased attenuation

  1. Effect of MR contrast agents on quantitative accuracy of PET in combined whole-body PET/MR imaging.

    Science.gov (United States)

    Lois, Cristina; Bezrukov, Ilja; Schmidt, Holger; Schwenzer, Nina; Werner, Matthias K; Kupferschläger, Jürgen; Beyer, Thomas

    2012-11-01

    Clinical PET/MR acquisition protocols entail the use of MR contrast agents (MRCA) that could potentially affect PET quantification following MR-based attenuation correction (AC). We assessed the effect of oral and intravenous (IV) MRCA on PET quantification in PET/MR imaging. We employed two MRCA: Lumirem (oral) and Gadovist (IV). First, we determined their reference PET attenuation values using a PET transmission scan (ECAT-EXACT HR+, Siemens) and a CT scan (PET/CT Biograph 16 HI-REZ, Siemens). Second, we evaluated the attenuation of PET signals in the presence of MRCA. Phantoms were filled with clinically relevant concentrations of MRCA in a background of water and (18)F-fluoride, and imaged using a PET/CT scanner (Biograph 16 HI-REZ, Siemens) and a PET/MR scanner (Biograph mMR, Siemens). Third, we investigated the effect of clinically relevant volumes of MRCA on MR-based AC using human pilot data: a patient study employing Gadovist (IV) and a volunteer study employing two different oral MRCA (Lumirem and pineapple juice). MR-based attenuation maps were calculated following Dixon-based fat-water segmentation and an external atlas-based and pattern recognition (AT&PR) algorithm. IV and oral MRCA in clinically relevant concentrations were found to have PET attenuation values similar to those of water. The phantom experiments showed that under clinical conditions IV and oral MRCA did not yield additional attenuation of PET emission signals. Patient scans showed that PET attenuation maps are not biased after the administration of IV MRCA but may be biased, however, after ingestion of iron oxide-based oral MRCA when segmentation-based AC algorithms are used. Alternative AC algorithms, such as AT&PR, or alternative oral contrast agents, such as pineapple juice, can yield unbiased attenuation maps. In clinical PET/MR scenarios MRCA are not expected to lead to markedly increased attenuation of the PET emission signals. MR-based attenuation maps may be biased by oral iron

  2. Water and polymer dynamics in highly crosslinked polyamide membranes

    Science.gov (United States)

    Frieberg, Bradley; Chan, Edwin; Tyagi, Madhu; Stafford, Christopher; Soles, Christopher

    Highly crosslinked polyamides for reverse osmosis are the state-of-the-art active material in membranes for desalination. The thin film composite membrane structure that is used commercially has been empirically designed to selectively allow the passage of water molecules and minimize the passage of solutes such as salt. However, due to the large roughness and variability of the polyamide layer, there is a limited understanding of the structure-property relationship for these materials as well as the transport mechanism. To better understand the water transport mechanism we measure the water and polymer dynamics of polyamide membranes using quasi-elastic neutron scattering (QENS). By hydrating the membrane with deuterated water, we are able to isolate the dynamics of the hydrogenated membrane on the pico- and nanosecond time scales. By subsequently hydrating the membranes with hydrogenated water, the QENS measurements on the same times scales reveal information about both the translational and rotational dynamics of water confined within the polyamide membrane. Further understanding of the water diffusion mechanism will establish design rules in which the performance of future membrane materials can be improved.

  3. Comparing mean high water and high water line shorelines: Should prosy-datum offsets be incorporated into shoreline change analysis?

    Science.gov (United States)

    Moore, L.J.; Ruggiero, P.; List, J.H.

    2006-01-01

    More than one type of shoreline indicator can be used in shoreline change analyses, and quantifying the effects of this practice on the resulting shoreline change rates is important. Comparison of three high water line (proxy-based) shorelines and a mean high water intercept (datum-based) shoreline collected from simultaneous aerial photographic and lidar surveys of a relatively steep reflective beach (tan ?? = 0.07), which experiences a moderately energetic wave climate (annual average Hs = 1.2 m), reveals an average horizontal offset of 18.8 m between the two types of shoreline indicators. Vertical offsets are also substantial and are correlated with foreshore beach slope and corresponding variations in wave runup. Incorporating the average horizontal offset into both a short-term, endpoint shoreline change analysis and a long-term, linear regression analysis causes rates to be shifted an average of -0.5 m/y and -0.1 m/y, respectively. The rate shift increases with increasing horizontal offset and decreasing measurement intervals and, depending on the rapidity of shoreline change rates, is responsible for varying degrees of analysis error. Our results demonstrate that under many circumstances, the error attributable to proxy-datum offsets is small relative to shoreline change rates and thus not important. Furthermore, we find that when the error associated with proxy-datum offsets is large enough to be important, the shoreline change rates themselves are not likely to be significant. A total water level model reveals that the high water line digitized by three independent coastal labs for this study was generated by a combination of large waves and a high tide several days before the collection of aerial photography. This illustrates the complexity of the high water line as a shoreline indicator and calls into question traditional definitions, which consider the high water line a wetted bound or "marks left by the previous high tide.".

  4. Correlation Between Apparent Diffusion Coefficients and Standardized Uptake Values in Hybrid (18)F-FDG PET/MR: Preliminary Results in Rectal Cancer.

    Science.gov (United States)

    Jeong, Ju Hye; Cho, Ihn Ho; Chun, Kyung Ah; Kong, Eun Jung; Kwon, Sang Don; Kim, Jae Hwang

    2016-06-01

    Fluorine-18-fluorodeoxyglucose ((18)F-FDG) positron emission tomography (PET) and diffusion-weighted magnetic resonance imaging (DWI) share the same role in clinical oncology and it is feasible to obtain the standardized uptake value (SUV) and apparent diffusion coefficient (ADC) simultaneously by emerging the hybrid positron emission tomography/magnetic resonance (PET/MR). This study investigated the correlation between the ADCs of rectal cancer lesions and their SUVs derived from hybrid PET/MR. Nine patients with histologically proven rectal adenocarcinoma (5 men, 4 women; mean age, 70 ± 15.91 years) underwent torso (18)F-FDG PET/CT and regional hybrid (18)F-FDG PET/MR sequentially. A fixed threshold value of 40 % of maximum uptake was used to determine tumor volume of interest (VOI) on PET image; SUVmax, SUVpeak, and SUVmean were calculated automatically. A single freehand region of interest (ROI) was drawn on high b-value (b1000) DWI image and copied to corresponding ADC map to determine the ADCmean of rectal cancer lesion. Spearman's rank correlation coefficient (ρ) was calculated to determine the correlation between SUVs and ADC values. SUVmax, SUVpeak, and SUVmean derived by hybrid PET/MR were 12.35 ± 4.66 (mean ± standard deviation), 9.66 ± 3.15 and 7.41 ± 2.54, respectively. The ADCmean value of rectal cancer lesions was 1.02 ± 0.08 × 10(-3)mm(2)/s. ADCmean was significantly and inversely correlated with SUV values (SUVmax, ρ = -0.95, p PET/MR study demonstrates a significant inverse correlation exists between metabolic activity on (18)F-FDG PET and water diffusion on DWI in rectal cancer.

  5. Quantitative myocardial blood flow imaging with integrated time-of-flight PET-MR.

    Science.gov (United States)

    Kero, Tanja; Nordström, Jonny; Harms, Hendrik J; Sörensen, Jens; Ahlström, Håkan; Lubberink, Mark

    2017-12-01

    The use of integrated PET-MR offers new opportunities for comprehensive assessment of cardiac morphology and function. However, little is known on the quantitative accuracy of cardiac PET imaging with integrated time-of-flight PET-MR. The aim of the present work was to validate the GE Signa PET-MR scanner for quantitative cardiac PET perfusion imaging. Eleven patients (nine male; mean age 59 years; range 46-74 years) with known or suspected coronary artery disease underwent 15O-water PET scans at rest and during adenosine-induced hyperaemia on a GE Discovery ST PET-CT and a GE Signa PET-MR scanner. PET-MR images were reconstructed using settings recommended by the manufacturer, including time-of-flight (TOF). Data were analysed semi-automatically using Cardiac VUer software, resulting in both parametric myocardial blood flow (MBF) images and segment-based MBF values. Correlation and agreement between PET-CT-based and PET-MR-based MBF values for all three coronary artery territories were assessed using regression analysis and intra-class correlation coefficients (ICC). In addition to the cardiac PET-MR reconstruction protocol as recommended by the manufacturer, comparisons were made using a PET-CT resolution-matched reconstruction protocol both without and with TOF to assess the effect of time-of-flight and reconstruction parameters on quantitative MBF values. Stress MBF data from one patient was excluded due to movement during the PET-CT scanning. Mean MBF values at rest and stress were (0.92 ± 0.12) and (2.74 ± 1.37) mL/g/min for PET-CT and (0.90 ± 0.23) and (2.65 ± 1.15) mL/g/min for PET-MR (p = 0.33 and p = 0.74). ICC between PET-CT-based and PET-MR-based regional MBF was 0.98. Image quality was improved with PET-MR as compared to PET-CT. ICC between PET-MR-based regional MBF with and without TOF and using different filter and reconstruction settings was 1.00. PET-MR-based MBF values correlated well with PET-CT-based MBF values and

  6. Microfluidics for Synthesis of Peptide-Based PET Tracers

    Directory of Open Access Journals (Sweden)

    Yang Liu

    2013-01-01

    Full Text Available Positron emission tomography (PET is a powerful noninvasive tool for acquisition of the physiological parameters in human and animals with the help of PET tracers. Among all the PET tracers, radiolabeled peptides have been widely explored for cancer-related receptor imaging due to their high affinity and specificity to receptors. But radiochemistry procedures for production of peptide-based PET tracers are usually complex, which makes large-scale clinical studies relatively challenging. New radiolabeling technologies which could simplify synthesis and purification procedures, are extremely needed. Over the last decade, microfluidics and lab-on-a-chip (LOC technology have boomed as powerful tools in the field of organic chemistry, which potentially provide significant help to the PET chemistry. In this minireview, microfluidic radiolabeling technology is described and its application for synthesis of peptide-based PET tracers is summarized and discussed.

  7. Comparing fludeoxyglucose F18-PET assessment of regional cerebral glucose metabolism and [11C]dihydrotetrabenazine-PET in evaluation of early dementia and mild cognitive impairment.

    Science.gov (United States)

    Albin, Roger L; Koeppe, Robert A; Burke, James F; Giordani, Bruno; Kilbourn, Michael R; Gilman, Sid; Frey, Kirk A

    2010-04-01

    To compare assessment of regional cerebral metabolic changes with [(11)C]dihydrotetrabenazine (DTBZ)-positron emission tomography (PET) measurement of regional cerebral blood flow (K(1)) and fludeoxyglucose F18 (FDG)-PET measurement of regional cerebral glucose uptake (CMR(glc)) in a clinically representative sample of subjects with mild dementia and mild cognitive impairment (MCI). [(11)C]Dihydrotetrabenazine-PET K(1) and FDG-PET CMR(glc) measurements were performed. University-based cognitive disorders clinic. Fifty subjects with either mild dementia (Mini-Mental State Examination score > or = 18) or MCI. Their results were compared with those of 80 normal control subjects. The DTBZ-PET regional K(1) and FDG-PET CMR(glc) measurements were compared with standard correlation analysis. The overall patterns of DTBZ-PET K(1) and FDG-PET CMR(glc) deficits were assessed with stereotaxic surface projections (SSPs) of parametric images. The DTBZ-PET regional K(1) and FDG-PET CMR(glc) measurements were highly correlated, both within and between subjects. The SSP maps of deficits in DTBZ-PET regional K(1) and FDG-PET CMR(glc) measurements were markedly similar. The DTBZ-PET K(1) SSP maps exhibited a mild decrease in sensitivity relative to FDG-PET CMR(glc) maps. Both DTBZ-PET K(1) and FDG-PET CMR(glc) measurements provide comparable information in assessment of regional cerebral metabolic deficits in mild dementia and MCI. Blood flow measures can assess regional cerebral metabolism deficits accurately in mild dementia and MCI. Blood flow assessments of regional cerebral metabolic deficits can be combined with tracer binding results to improve utility of PET imaging in mild dementia and MCI.

  8. Factors in children's attitudes toward pets.

    Science.gov (United States)

    Kidd, A H; Kidd, R M

    1990-06-01

    This study investigates parental attitudes, family size, and structure, and presence or absence of household pets as influences on children's attitudes toward pets. 700 parents completed a Melson Parent Questionnaire which assesses children's activities with, interest in, and responsibility for pets, and completed either the Wilson Attitude Inventory for Pet Owners or for Nonpet Owners. Results indicated: that children of strongly attached adults and in pet-owning homes scored higher on Activities and Interest than children of weakly attached adults and in nonpet-owning homes; that children of both sexes in one-parent homes scored higher on Responsibility than in two-parent homes; that boys scored higher on Interest, girls on Activities, and both sexes on Responsibility when mothers worked full time rather than part-time; that girls scored higher on Interest and, in pet-owning homes, on Responsibility than boys; that preschoolers scored lower on Activities and Interest than older children, and that grade schoolers scored higher on Responsibility than preschoolers or high schoolers.

  9. Evaluation of PET Scanner Performance in PET/MR and PET/CT Systems: NEMA Tests.

    Science.gov (United States)

    Demir, Mustafa; Toklu, Türkay; Abuqbeitah, Mohammad; Çetin, Hüseyin; Sezgin, H Sezer; Yeyin, Nami; Sönmezoğlu, Kerim

    2018-02-01

    The aim of the present study was to compare the performance of positron emission tomography (PET) component of PET/computed tomography (CT) with new emerging PET/magnetic resonance (MR) of the same vendor. According to National Electrical Manufacturers Association NU2-07, five separate experimental tests were performed to evaluate the performance of PET scanner of General Electric GE company; SIGNATM model PET/MR and GE Discovery 710 model PET/CT. The main investigated aspects were spatial resolution, sensitivity, scatter fraction, count rate performance, image quality, count loss and random events correction accuracy. The findings of this study demonstrated superior sensitivity (~ 4 folds) of PET scanner in PET/MR compared to PET/CT system. Image quality test exhibited higher contrast in PET/MR (~ 9%) compared with PET/CT. The scatter fraction of PET/MR was 43.4% at noise equivalent count rate (NECR) peak of 218 kcps and the corresponding activity concentration was 17.7 kBq/cc. Whereas the scatter fraction of PET/CT was found as 39.2% at NECR peak of 72 kcps and activity concentration of 24.3 kBq/cc. The percentage error of the random event correction accuracy was 3.4% and 3.1% in PET/MR and PET/CT, respectively. It was concluded that PET/MR system is about 4 times more sensitive than PET/CT, and the contrast of hot lesions in PET/MR was ~ 9% higher than PET/CT. These outcomes also emphasize the possibility to achieve excellent clinical PET images with low administered dose and/or a short acquisition time in PET/MR.

  10. Diagnostic performances of the S.R.S. (scintigraphy of somatostatin receptors) and of the PET-F.D.G. in the extension situation of the well differentiated endocrine carcinomas at high Ki67; Performances diagnostiques de la SRS et de la TEP-FDG dans le bilan d'extension des carcinomes endocrines bien differencies a Ki67 eleve ({>=} 10%)

    Energy Technology Data Exchange (ETDEWEB)

    Abgrala, R.; Leboulleux, S.; Deandreis, D.; Lumbroso, J.; Schlumberger, M.; Baudin, E. [Medecine nucleaire, institut Gustave-Roussy, Villejuif, (France); Auperin, A. [Biostatistiques, Institut Gustave-Roussy, Villejuif, (France); Dromain, C. [radiologie, institut Gustave-Roussy, Villejuif, (France); Guigay, J. [pneumologie, institut Gustave-Roussy, Villejuif, (France); Ducreux, M. [hepato-gastroenterologie, Institut Gustave-Roussy, Villejuif, (France)

    2009-05-15

    The results suggest that among 90% of patients with well differentiated endocrine carcinomas at high Ki, the PET-F.D.G. is more noticeable or equivalent to the scintigraphy of somatostatin receptors (S.R.S.). (N.C.)

  11. Evaluation of 18F-fluoride PET/MR and PET/CT in patients with foot pain of unclear cause.

    Science.gov (United States)

    Rauscher, Isabel; Beer, Ambros J; Schaeffeler, Christoph; Souvatzoglou, Michael; Crönlein, Moritz; Kirchhoff, Chlodwig; Sandmann, Gunther; Fürst, Sebastian; Kilger, Robert; Herz, Michael; Ziegler, Sybille; Schwaiger, Markus; Eiber, Matthias

    2015-03-01

    Our objective was to compare the quality and diagnostic performance of (18)F-fluoride PET/MR imaging with that of (18)F-fluoride PET/CT imaging in patients with foot pain of unclear cause. Twenty-two patients (9 men, 13 women; mean age, 48 ± 18 y; range, 20-78 y) were prospectively included in this study and underwent a single-injection dual-imaging protocol with (18)F-fluoride PET/CT and PET/MR. At a minimum, the PET/MR protocol included T1-weighted spin echo and proton-density fat-saturated sequences in 2 planes each with simultaneous acquisition of PET over 20 min. PET/CT included a native isotropic (0.6 mm) diagnostic CT scan (80 kV, 165 mAs) and a subsequent PET scan (2 min per bed position). By consensus, 2 masked interpreters randomly assessed both PET datasets for image quality (3-point scale) and for the presence of focal lesions with increased (18)F-fluoride uptake (maximum of 4 lesions). For each dataset (PET/CT vs. PET/MR), the diagnoses were defined using both PET and a morphologic dataset. Standardized uptake values (SUVs) from the 2 devices were compared using linear correlation and Bland-Altman plots. Moreover, we estimated the potential for dose reduction for PET/MR compared with PET/CT considering the longer acquisition time of PET/MR analyzing count rate statistics. Image quality was rated diagnostic for both PET datasets. However, with a mean rating of 3.0/3 for PET/MR and 2.3/3 for PET/CT, image quality was significantly superior for PET/MR (P PET/MR and PET/CT was equivalent, with the same 42 lesions showing focal (18)F-fluoride uptake. In PET/MR, the mean SUVmean was 10.4 (range, 2.0-67.7) and the mean SUVmax was 15.6 (range, 2.9-94.1). In PET/CT, the corresponding mean SUVmean of PET/CT was 10.2 (range, 1.8-55.6) and the mean SUVmax was 16.3 (range, 2.5-117.5), resulting in a high linear correlation coefficient (r = 0.96, P PET/MR was more specific in nondegenerative pathologies because of the higher soft-tissue and bone marrow contrast

  12. Electrochemical study of aluminum corrosion in boiling high purity water

    Science.gov (United States)

    Draley, J. E.; Legault, R. A.

    1969-01-01

    Electrochemical study of aluminum corrosion in boiling high-purity water includes an equation relating current and electrochemical potential derived on the basis of a physical model of the corrosion process. The work involved an examination of the cathodic polarization behavior of 1100 aluminum during aqueous oxidation.

  13. Beryllium-10 concentrations in water samples of high northern latitudes

    Energy Technology Data Exchange (ETDEWEB)

    Strobl, C.; Eisenhauer, A.; Schulz, V.; Baumann, S.; Mangini, A. [Heidelberger Akademie der Wissenschaften, Heildelberg (Germany); Kubik, P.W. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-09-01

    {sup 10}Be concentrations in the water column of high northern latitudes were not available so far. We present different {sup 10}Be profiles from the Norwegian-Greenland Sea, the Arctic Ocean, and the Laptev Sea. (author) 3 fig., 3 refs.

  14. Automatic extraction of forward stroke volume using dynamic PET/CT

    DEFF Research Database (Denmark)

    Harms, Hans; Tolbod, Lars Poulsen; Hansson, Nils Henrik Stubkjær

    2015-01-01

    .001 for all). FSV based on 11 C-acetate and 15 O-water correlated highly (r = 0.99, slope = 1.03) with no significant difference between FSV estimates (p = 0.14). Conclusions FSV can be obtained automatically using dynamic PET/CT and cluster analysis. Results are almost identical for 11 C-acetate and 15 O...

  15. Importance of PET/CT in lymphoma diagnostics; Stellenwert der PET/CT in der Lymphomdiagnostik

    Energy Technology Data Exchange (ETDEWEB)

    Afshar-Oromieh, A.; Kratochwil, C.; Haberkorn, U.; Giesel, F.L. [Universitaetsklinikum Heidelberg, Abteilung fuer Nuklearmedizin, Radiologische Klinik, Heidelberg (Germany)

    2012-04-15

    Staging or re-staging of lymphomas using conventional imaging modalities is based on morphological changes, usually on the diameter of lesions. However, vitality of tumors cannot be evaluated. In this context computed tomography (CT) has been used as a standard modality. Since the introduction of positron emission tomography (PET), evaluation of tumor vitality has become possible. Moreover PET/CT hybrid scanners were brought onto the market one decade ago. The fluorodeoxyglucose (FDG) PET/CT technique is now accepted as one of the most accurate modalities in the diagnosis of aggressive lymphomas due to a high FDG uptake (overall accuracy > 90%, sensitivity >90%). However, indolent lymphomas suffer from lower FDG uptake due to a moderate metabolic activity. After the introduction of PET/CT hybrid imaging the specificity of this diagnostic technique increased significantly compared to PET alone (from > 80% to > 90%). With the utilization of PET approximately 20% more lesions are detected when comparing to CT alone and in up to 15% of the patients this also results in a change of the therapeutic regime. As post-chemotherapy scar tissue usually persists for months, evaluation of vitality within residual bulks using FDG-PET can predict therapy response much earlier than CT, enabling therapy stratification. Other PET tracers apart from FDG have low impact in imaging of lymphomas and only the thymidine analogue fluorothymidine (FLT) is used in some cases for non-invasive measurement of proliferation. Despite the capability of FDG-PET/CT there is no evidence that the improvement in diagnostics is translated into a better patient outcome and therefore warrants the high costs. False positive findings in PET can result in unnecessary treatment escalation with subsequent higher therapy-associated toxicity and costs. Some pitfalls can be avoided by scheduling PET scans carefully. As treatment-induced inflammation early after therapy can be misinterpreted as vital tumor tissue

  16. Optimizing Nanopore Surface Properties for High-Efficiency Water Desalination

    Science.gov (United States)

    Cohen-Tanugi, David; Grossman, Jeffrey

    2011-03-01

    As water resources worldwide become rapidly scarcer, it is becoming increasingly important to devise new techniques to obtain clean water from seawater. At present, water purification technologies are limited by costly energy requirements relative to the theoretical thermodynamic limit and by insufficient understanding of the physical processes underlying ion filtration and fluid transport at the molecular scale. New advances in computational materials science offer a promising way to deepen our understanding of these physical phenomena. In this presentation, we describe a new approach for high-efficiency water desalination based on surface-engineered porous materials. This approach is especially relevant for promising technologies such as nanofiltration and membrane distillation, which offers promising advantages over traditional desalination technologies using mesoporous membranes that are only permeable to pure water vapor. More accurate molecular modeling of mesoporous and nanoporous materials represents a key step towards efficient large-scale treatment of seawater. Results regarding the effect of pore properties (surface texture, morphology, density, tortuosity) on desired performance characteristics such as ion selectivity, maximal water flux and energy requirements will be presented.

  17. Glycol-Substitute for High Power RF Water Loads

    CERN Document Server

    Ebert, Michael

    2005-01-01

    In water loads for high power rf applications, power is dissipated directly into the coolant. Loads for frequencies below approx. 1GHz are ordinarily using an ethylene glycol-water mixture as coolant. The rf systems at DESY utilize about 100 glycol water loads with powers ranging up to 600kW. Due to the increased ecological awareness, the use of glycol is now considered to be problematic. In EU it is forbidden to discharge glycol into the waste water system. In case of cooling system leakages one has to make sure that no glycol is lost. Since it is nearly impossible to avoid any glycol loss in large rf systems, a glycol-substitute was searched for and found. The found sodium-molybdate based substitute is actually a additive for corrosion protection in water systems. Sodium-molybdate is ecologically harmless; for instance, it is also used as fertilizer in agriculture. A homoeopathic dose of 0.4% mixed into deionised water gives better rf absorption characteristics than a 30% glycol mixture. The rf coolant feat...

  18. A High Rated Solar Water Distillation Unit for Solar Homes

    Directory of Open Access Journals (Sweden)

    Abhishek Saxena

    2016-01-01

    Full Text Available India is presently focusing on complete utilization of solar energy and saving fossil fuels, which are limited. Various solar energy systems like solar cookers, solar water heaters, solar lanterns, solar PV lights, and solar lamps are continuously availing by the people of India at a low cost and on good subsidies. Apart from this, India is a solar energy promising country with a good number of solar homes (carrying solar energy systems in its various locations. The present paper focuses on a unique combination of solar dish cooker (SDC and solar water heater (SWH to produce distilled water with a high distillate and a high daily productivity. The procedure has been discussed on the basis of experimental testing to produce distilled water by combining an evacuated type SWH and a SDC. Experimentation has been carried out in MIT, Moradabad (longitude, 28.83°N, and latitude, 78.78°E by developing the same experimental setup on behalf of solar homes. The daily productivity of distilled water was found around 3.66 litres per day in full sunshine hours for an approximated pH value of 7.7 and a ppm value of 21. The payback period (PBP has been estimated around 1.16 years of the present system.

  19. A continuous high resolution water isotope dataset to constrain Alpine water balance estimates

    Science.gov (United States)

    Michelon, Anthony; Ceperley, Natalie; Beria, Harsh; Larsen, Josh; Schaefli, Bettina

    2017-04-01

    Water delivered from Alpine environments is a crucial resource for many countries around the world. Precipitation accumulated during cold seasons as snowpack or glaciers is often an important source of water during warm (dry) season but also a dominant contributor to the annual water balance. In Switzerland, water from high Alpine, glacier-fed catchments provides a large portion of both the hydroelectric power and water supply. However, large uncertainties regarding changes in glacier volume and snow accumulation can have significant impacts on hydrologic, biologic, physical and economic understanding, modeling, and predictions. Accurately quantifying these water resources is therefore an on-going challenge. Given the well-known difficulty observing solid precipitation (snowfall), it can be assumed that most of the uncertainty in water balance estimates for snow-dominated environments is due to: 1) Poor measurement of winter precipitation and 2) A poor estimation of timing and amount of snow melt. It is noteworthy that the timing of melt plays a crucial role even for annual water balance estimates since it might significantly influence melt runoff flow paths and thereby groundwater recharge. We use continuous monitoring of water stable isotopes over the entire annual cycle in an Alpine catchment to shed light on how such observations can constrain water balance estimates. The selected catchment is the experimental Vallon de Nant catchment in the Vaud Alps of Switzerland, where detailed hydrologic observations have recently started in addition to the existing vegetation and soil investigations. The Vallon de Nant (14 km2, and an altitude ranging from 1200 to 3051 m) is a narrow valley that accumulates large amounts of snow during winter. In spring and summer, the river discharge is mainly supplied by snowmelt, with additional inputs from a small glacier and rainfall. Continuous monitoring of water stable isotopes (δO18 and δD) is combined with measurements of

  20. Usefulness of {sup 18}F-FDG PET, combined FDG-PET/CT and EUS in diagnosing primary pancreatic carcinoma: A meta-analysis

    Energy Technology Data Exchange (ETDEWEB)

    Tang Shuang [Department of Nuclear Medicine, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200127 (China); Huang Gang, E-mail: huang2802@163.com [Department of Nuclear Medicine, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200127 (China); Liu Jianjun [Department of Nuclear Medicine, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200127 (China); Liu Tao [Department of Orthopedics, Soochow University, Suzhou (China); Treven, Lyndal [Faculty of Public Health, University of Sydney, Sydney (Australia); Song Saoli; Zhang Chenpeng; Pan Lingling [Department of Nuclear Medicine, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200127 (China); Zhang Ting [Department of Anesthesiology, Renji Hospital, Shanghai (China)

    2011-04-15

    The aim was to evaluate the diagnostic value of {sup 18}F-fluorodeoxyglucose-positron emission tomography ({sup 18}F-FDG PET), combined {sup 18}F-fluorodeoxyglucose-positron emission tomography/computed tomography ({sup 18}F-FDG PET/CT) and endoscopic ultrasonography (EUS) in diagnosing patients with pancreatic carcinoma. MEDLINE, EMBASE, Cochrane library and some other databases, from January 1966 to April 2009, were searched for initial studies. All the studies published in English or Chinese relating to the diagnostic value of {sup 18}F-FDG PET, PET/CT and EUS for patients with pancreatic cancer were collected. Methodological quality was assessed. The statistic software called 'Meta-Disc 1.4' was used for data analysis. Results: 51 studies were included in this meta-analysis. The pooled sensitivity estimate for combined PET/CT (90.1%) was significantly higher than PET (88.4%) and EUS (81.2%). The pooled specificity estimate for EUS (93.2%) was significantly higher than PET (83.1%) and PET/CT (80.1%). The pooled DOR estimate for EUS (49.774) was significantly higher than PET (32.778) and PET/CT (27.105). SROC curves for PET/CT and EUS showed a little better diagnostic accuracy than PET alone. For PET alone, when interpreted the results with knowledge of other imaging tests, its sensitivity (89.4%) and specificity (80.1%) were closer to PET/CT. For EUS, its diagnostic value decreased in differentiating pancreatic cancer for patients with chronic pancreatitis. In conclusion, PET/CT was a high sensitive and EUS was a high specific modality in diagnosing patients with pancreatic cancer. PET/CT and EUS could play different roles during different conditions in diagnosing pancreatic carcinoma.

  1. Comparison of 18F-FDG PET/CT and PET/MRI in patients with multiple myeloma

    OpenAIRE

    Sachpekidis, Christos; Hillengass, Jens; Goldschmidt, Hartmut; Mosebach, Jennifer; Pan, Leyun; Schlemmer, Heinz-Peter; Haberkorn, Uwe; Dimitrakopoulou-Strauss, Antonia

    2015-01-01

    PET/MRI represents a promising hybrid imaging modality with several potential clinical applications. Although PET/MRI seems highly attractive in the diagnostic approach of multiple myeloma (MM), its role has not yet been evaluated. The aims of this prospective study are to evaluate the feasibility of 18F-FDG PET/MRI in detection of MM lesions, and to investigate the reproducibility of bone marrow lesions detection and quantitative data of 18F-FDG uptake between the functional (PET) component ...

  2. Diagnostic test accuracy study of 18F-sodium fluoride PET/CT, 99mTc-labelled diphosphonate SPECT/CT, and planar bone scintigraphy for diagnosis of bone metastases in newly diagnosed, high-risk prostate cancer

    DEFF Research Database (Denmark)

    Fonager, Randi F; Zacho, Helle D; Langkilde, Niels C

    2017-01-01

    considered eligible for androgen-deprivation therapy (ADT) were included in this study. BS, SPECT/CT, and NaF PET/CT, were performed prior to treatment and were repeated after six months of ADT. Baseline images from each index test were independently read by two experienced readers. The reference standard...... was based on a consensus decision made by a multidisciplinary team on the basis of baseline and follow-up images of the index tests, the findings of the baseline index tests by the experienced readers, and any available imaging, biochemical, and clinical data, including the response to ADT. Twenty-seven (73......%, and 96%, respectively, and the negative predictive values were 60%, 77% and 75%, respectively. No statistically significant difference among the three imaging modalities was observed. All three imaging modalities showed high sensitivity and specificity. NaF PET/CT and SPECT/CT showed numerically improved...

  3. Volume-Based F-18 FDG PET/CT Imaging Markers Provide Supplemental Prognostic Information to Histologic Grading in Patients With High-Grade Bone or Soft Tissue Sarcoma

    DEFF Research Database (Denmark)

    Andersen, Kim Francis; Fuglo, Hanna Maria; Rasmussen, Sine Hvid

    2015-01-01

    to 2012 including 92 patients with histologically verified high-grade BS (N = 37) or STS (N = 55). All patients underwent a pretreatment F-18 FDG PET/CT scan. Clinical data were registered. Measurements of the accuracy of metabolic tumor volume with a preset threshold of 40% of the maximum standardized...... analysis. Kaplan-Meier survival estimates and log-rank test were used to compare the degree of equality of survival distributions. Prognostic variables with related hazard ratios (HR) were assessed using Cox proportional hazards regression analysis.Forty-one of 92 patients died during follow-up (45%; 12 BS.......05, HR 3.37 [95% CI 1.02-11.11]). No significant results were demonstrated for MTV40%.Volume-based F-18 FDG PET/CT imaging markers in terms of pretreatment estimation of TLG provide supplemental prognostic information to histologic grading, with significant independent properties for prediction...

  4. Assessment of recycled PET properties for application on oil wells as sand control agents; Avaliacao de propriedades de PET reciclado para aplicacao em pocos de petroleo como agente de contencao de areia

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Alexandre Zacarias Ignacio [PETROBRAS, Rio de Janeiro, RJ (Brazil); Delpech, Marcia Cerqueira [Universidade do Estado do Rio de Janeiro (IQ/UERJ), RJ (Brazil). Inst. de Quimica], e-mail: mcd@uerj.br

    2008-07-01

    The Sand Control is fundamental for oil production in unconsolidated sandstone formations. It consists of the installation of a filter made of stainless steel screens and grained materials (sand control agents) which are, normally, high density inorganic substances (sand, ceramic, bauxite). Shallow formations, near to the sea bed, are more sensitive and need different kinds of sand control agents with low density. The objective of this work was the evaluation of recycled poly(ethylene terephthalate), PET, as sand control agent for oil wells. Pack permeability and thermal stability tests results, after up to six months of exposure to sea water and crude oil, have indicated that the recycled PET kept the necessary characteristics for the proposed application. Also, it was observed that the PET grain pack did not presented significant property modifications in the exposure conditions, when compared to the non-exposed samples. (author)

  5. Feasibility of in situ, high-resolution correlation of tracer uptake with histopathology by quantitative autoradiography of biopsy specimens obtained under 18F-FDG PET/CT guidance.

    Science.gov (United States)

    Fanchon, Louise M; Dogan, Snjezana; Moreira, Andre L; Carlin, Sean A; Schmidtlein, C Ross; Yorke, Ellen; Apte, Aditya P; Burger, Irene A; Durack, Jeremy C; Erinjeri, Joseph P; Maybody, Majid; Schöder, Heiko; Siegelbaum, Robert H; Sofocleous, Constantinos T; Deasy, Joseph O; Solomon, Stephen B; Humm, John L; Kirov, Assen S

    2015-04-01

    correlation coefficient between the mean specimen SUVARG and SUVPET was 0.66. Performing QABS on core-biopsy specimens obtained using PET/CT guidance enables in situ correlation of (18)F-FDG tracer uptake and histopathology on a millimeter scale. QABS promises to provide useful information for guiding interventional radiology procedures and localized therapies and for in situ high-spatial-resolution validation of radiopharmaceutical uptake. © 2015 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

  6. Transport of water vapor and inert gas mixtures through highly selective and highly permeable polymer membranes

    NARCIS (Netherlands)

    Metz, S.J.; van de Ven, W.J.C.; Potreck, Jens; Mulder, M.H.V.; Wessling, Matthias

    2005-01-01

    This paper studies in detail the measurement of the permeation properties of highly permeable and highly selective polymers for water vapor/nitrogen gas mixtures. The analysis of the mass transport of a highly permeable polymer is complicated by the presence of stagnant boundary layers at feed and

  7. Ultra-high pressure water jet: Baseline report; Greenbook (chapter)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-07-31

    The ultra-high pressure waterjet technology was being evaluated at Florida International University (FIU) as a baseline technology. In conjunction with FIU`s evaluation of efficiency and cost, this report covers the evaluation conducted for safety and health issues. It is a commercially available technology and has been used for various projects at locations throughout the country. The ultra-high pressure waterjet technology acts as a cutting tool for the removal of surface substrates. The Husky{trademark} pump feeds water to a lance that directs the high pressure water at the surface to be removed. The technologies being tested for concrete decontamination are targeted for alpha contamination. The safety and health evaluation during the human factors assessment focused on two main areas: noise and dust.

  8. Combined PET/MRI

    DEFF Research Database (Denmark)

    Bailey, D. L.; Pichler, B. J.; Gückel, B.

    2015-01-01

    This paper summarises key themes and discussions from the 4th international workshop dedicated to the advancement of the technical, scientific and clinical applications of combined positron emission tomography (PET)/magnetic resonance imaging (MRI) systems that was held in Tübingen, Germany, from...... February 23 to 27, 2015. Specifically, we summarise the three days of invited presentations from active researchers in this and associated fields augmented by round table discussions and dialogue boards with specific topics. These include the use of PET/MRI in cardiovascular disease, paediatrics, oncology......, neurology and multi-parametric imaging, the latter of which was suggested as a key promoting factor for the wider adoption of integrated PET/MRI. Discussions throughout the workshop and a poll taken on the final day demonstrated that attendees felt more strongly that PET/MRI has further advanced in both...

  9. Pet Disaster Preparedness

    Science.gov (United States)

    ... a Volunteer Volunteer Opportunities Volunteer to Sound the Alarm Sign in to Volunteer Connection About Us Our ... may be more comfortable together, be prepared to house them separately. Include your pets in evacuation drills ...

  10. Pet Allergy Quiz

    Science.gov (United States)

    ... of U.S. households include a member of the dog or cat family. Yet, millions of people suffer from pet allergies. Take this quiz to test your knowledge about popular myths as well as coping strategies related to ...

  11. Cold Weather Pet Safety

    Science.gov (United States)

    ... AVMA Who We Are Governance AVMA Careers AVMF Student AVMA (SAVMA) Allied Organizations AVMA Store (Products) Policy ... Protect family: Odds are your pet will be spending more time inside during the winter, so it's ...

  12. Prenatal exposure to mite and pet allergens and total serum IgE at birth in high-risk children.

    NARCIS (Netherlands)

    Schonberger, H.J.; Dompeling, E.C.; Knottnerus, J.A.; Kuiper, S.; Weel, C. van; Schayck, C.P. van

    2005-01-01

    To examine the relationship between prenatal exposure to mite, cat and dog allergens and total serum IgE at birth in newborns at high risk of asthma. In the homes of 221 newborns with at least one first-degree relative with asthma, concentrations (ng/g dust) of allergens of house dust mite (mite),

  13. Effects of high amphetamine dose on mood and cerebral glucose metabolism in normal volunteers using positron emission tomography (PET)

    NARCIS (Netherlands)

    Vollenweider, FX; Maguire, RP; Leenders, KL; Mathys, K; Angst, J

    1998-01-01

    The effects of high euphorigenic doses of D-amphetamine (0.9-1.0 mg/kg p.o.) on regional cerebral glucose metabolism (rCMRglu) and psychological measures were investigated in 10 healthy human volunteers using a within-subject design and [F-18]-fluorodeoxygrucose positron emission tomography

  14. PET Imaging of Tumor-Associated Macrophages with 89Zr-Labeled High-Density Lipoprotein Nanoparticles

    NARCIS (Netherlands)

    Pérez-Medina, Carlos; Tang, Jun; Abdel-Atti, Dalya; Hogstad, Brandon; Merad, Miriam; Fisher, Edward A.; Fayad, Zahi A.; Lewis, Jason S.; Mulder, Willem J. M.; Reiner, Thomas

    2015-01-01

    Tumor-associated macrophages (TAMs) are increasingly investigated in cancer immunology and are considered a promising target for better and tailored treatment of malignant growth. Although TAMs also have high diagnostic and prognostic value, TAM imaging still remains largely unexplored. Here, we

  15. Reliability of semiquantitative {sup 18}F-FDG PET parameters derived from simultaneous brain PET/MRI: A feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Jena, Amarnath, E-mail: drjena2002@yahoo.com [Department of Molecular Imaging and Nuclear Medicine, Indraprastha Apollo Hospitals, Sarita Vihar, Mathura Road, New Delhi 110076, Delhi (India); Taneja, Sangeeta, E-mail: s_taneja1974@yahoo.com [Department of Molecular Imaging and Nuclear Medicine, Indraprastha Apollo Hospitals, Sarita Vihar, Mathura Road, New Delhi 110076, Delhi (India); Goel, Reema, E-mail: reemagoell@gmail.com [Department of Molecular Imaging and Nuclear Medicine, Indraprastha Apollo Hospitals, Sarita Vihar, Mathura Road, New Delhi 110076, Delhi (India); Renjen, Pushpendranath, E-mail: pnrenjen@hotmail.com [Department of Neurology, Indraprastha Apollo Hospitals, Sarita Vihar, Mathura Road, New Delhi 110076, Delhi (India); Negi, Pradeep, E-mail: pradeepmri@rediffmail.com [Department of Molecular Imaging and Nuclear Medicine, Indraprastha Apollo Hospitals, Sarita Vihar, Mathura Road, New Delhi 110076, Delhi (India)

    2014-07-15

    Purpose: Simultaneous brain PET/MRI faces an important issue of validation of accurate MRI based attenuation correction (AC) method for precise quantitation of brain PET data unlike in PET/CT systems where the use of standard, validated CT based AC is routinely available. The aim of this study was to investigate the feasibility of evaluation of semiquantitative {sup 18}F-FDG PET parameters derived from simultaneous brain PET/MRI using ultrashort echo time (UTE) sequences for AC and to assess their agreement with those obtained from PET/CT examination. Methods: Sixteen patients (age range 18–73 years; mean age 49.43 (19.3) years; 13 men 3 women) underwent simultaneous brain PET/MRI followed immediately by PET/CT. Quantitative analysis of brain PET images obtained from both studies was undertaken using Scenium v.1 brain analysis software package. Twenty ROIs for various brain regions were system generated and 6 semiquantitative parameters including maximum standardized uptake value (SUV max), SUV mean, minimum SUV (SUV min), minimum standard deviation (SD min), maximum SD (SD max) and SD from mean were calculated for both sets of PET data for each patient. Intra-class correlation coefficients (ICCs) were determined to assess agreement between the various semiquantitative parameters for the two PET data sets. Results: Intra-class co-relation between the two PET data sets for SUV max, SUV mean and SD max was highly significant (p < 0.00) for all the 20 predefined brain regions with ICC > 0.9. SD from mean was also found to be statistically significant for all the predefined brain regions with ICC > 0.8. However, SUV max and SUV mean values obtained from PET/MRI were significantly lower compared to those of PET/CT for all the predefined brain regions. Conclusion: PET quantitation accuracy using the MRI based UTE sequences for AC in simultaneous brain PET/MRI is reliable in a clinical setting, being similar to that obtained using PET/CT.

  16. PET Imaging Stability Measurements During Simultaneous Pulsing of Aggressive MR Sequences on the SIGNA PET/MR System.

    Science.gov (United States)

    Deller, Timothy W; Khalighi, Mohammad Mehdi; Jansen, Floris P; Glover, Gary H

    2018-01-01

    The recent introduction of simultaneous whole-body PET/MR scanners has enabled new research taking advantage of the complementary information obtainable with PET and MRI. One such application is kinetic modeling, which requires high levels of PET quantitative stability. To accomplish the required PET stability levels, the PET subsystem must be sufficiently isolated from the effects of MR activity. Performance measurements have previously been published, demonstrating sufficient PET stability in the presence of MR pulsing for typical clinical use; however, PET stability during radiofrequency (RF)-intensive and gradient-intensive sequences has not previously been evaluated for a clinical whole-body scanner. In this work, PET stability of the GE SIGNA PET/MR was examined during simultaneous scanning of aggressive MR pulse sequences. Methods: PET performance tests were acquired with MR idle and during simultaneous MR pulsing. Recent system improvements mitigating RF interference and gain variation were used. A fast recovery fast spin echo MR sequence was selected for high RF power, and an echo planar imaging sequence was selected for its high heat-inducing gradients. Measurements were performed to determine PET stability under varying MR conditions using the following metrics: sensitivity, scatter fraction, contrast recovery, uniformity, count rate performance, and image quantitation. A final PET quantitative stability assessment for simultaneous PET scanning during functional MRI studies was performed with a spiral in-and-out gradient echo sequence. Results: Quantitation stability of a 68Ge flood phantom was demonstrated within 0.34%. Normalized sensitivity was stable during simultaneous scanning within 0.3%. Scatter fraction measured with a 68Ge line source in the scatter phantom was stable within the range of 40.4%-40.6%. Contrast recovery and uniformity were comparable for PET images acquired simultaneously with multiple MR conditions. Peak noise equivalent count

  17. Combined PET/MRI

    DEFF Research Database (Denmark)

    Bailey, D L; Pichler, B J; Gückel, B

    2018-01-01

    The 6th annual meeting to address key issues in positron emission tomography (PET)/magnetic resonance imaging (MRI) was held again in Tübingen, Germany, from March 27 to 29, 2017. Over three days of invited plenary lectures, round table discussions and dialogue board deliberations, participants c...... of response to pharmacological interventions and therapies. As such, PET/MRI is a key to advancing medicine and patient care....

  18. Comparison of high resolution whole-body MRI using parallel imaging and PET-CT. First experiences with a 32-channel MRI system; Hochaufloesendes Ganzkoerpertumorstaging unter Verwendung paralleler Bildgebung im Vergleich zur PET-CT. Erste Erfahrungen auf einem 32-Kanal-MRT-System

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, G.P.; Baur-Melnyk, A.; Reiser, M.F.; Schoenberg, S.O. [Klinikum Grosshadern der Ludwig-Maximilians-Universitaet Muenchen, Institut fuer Klinische Radiologie (Germany); Tiling, R.; Hahn, K. [Klinikum Grosshadern der Ludwig-Maximilians-Universitaet Muenchen, Klinik und Poliklinik fuer Nuklearmedizin (Germany)

    2004-09-01

    To compare the accuracy in the detection and staging of various malignant tumors with high resolution whole-body MRI using parallel imaging with whole-body dual-modality PET-CT. Preliminary results of an interim analysis from a prospective, blinded study are presented, in which 20 patients (mean age 59 years, range 27-77 years) with different oncological diseases underwent whole-body dual modality FDG-PET-CT screening for tumor search or staging in case of confirmed or suspected metastatic disease. All patients also underwent whole-body MRI imaging with the use of parallel imaging (iPAT). High-resolution coronal T1w- and STIR-sequences of 5 body levels with 512 x 512 matrix, axial fast T2w imaging of lung and abdomen (HASTE), contrast-enhanced dynamic and static T1w-sequences of liver, brain, abdomen, and pelvis were performed. Using a 32-channel whole-body MRI scanner (Magnetom Avanto, Siemens Medical Solutions) with a total field of view of 205 cm and free table movement, all patients could be covered from head to toe within one examination. With this technique, high spatial resolution and acceptable scanning times could be obtained. Two experienced radiologists read the MRI-scans, one radiologist and one nuclear scientist read PET-CT scans, each in consensus in a clinical setting. Delineation of the primary tumor (T-stage) or recurrent tumor, pathologic lymph node involvement, as well as degree and localization of metastatic disease, was assessed using PET-CT as standard of reference. Metastases from gastrointestinal tumor (25%) and breast cancer (25%), genitourinary tumor (15%) and malignant melanoma (15%) were detected. In 4/20 patients the primary tumor was identified, 2/20 patients showed recurrent tumor. Of 140 malignant lesions detected by PET-CT, 124 lesions were detected with MRI, resulting in a sensitivity of 89% at a specificity of 86%. In malignant lymph node detection, sensitivity of MRI was 83% and specificity 85%. Whole-body MRI is a promising

  19. Ultra-high pressure water jet: Baseline report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-07-31

    The ultra-high pressure waterjet technology was being evaluated at Florida International University (FIU) as a baseline technology. In conjunction with FIU`s evaluation of efficiency and cost, this report covers the evaluation conducted for safety and health issues. It is a commercially available technology and has been used for various projects at locations throughout the country. The ultra-high pressure waterjet technology acts as a cutting tool for the removal of surface substrates. The Husky{trademark} pump feeds water to a lance that directs the high pressure water at the surface to be removed. The safety and health evaluation during the testing demonstration focused on two main areas of exposure. These were dust and noise. The dust exposure was found to be minimal, which would be expected due to the wet environment inherent in the technology, but noise exposure was at a significant level. Further testing for noise is recommended because of the outdoor environment where the testing demonstration took place. In addition, other areas of concern found were arm-hand vibration, ergonomics, heat stress, tripping hazards, electrical hazards, lockout/tagout, fall hazards, slipping hazards, hazards associated with the high pressure water, and hazards associated with air pressure systems.

  20. Record-high specific conductance and water temperature in San Francisco Bay during water year 2015

    Science.gov (United States)

    Work, Paul; Downing-Kunz, Maureen; Livsey, Daniel

    2017-02-22

    The San Francisco estuary is commonly defined to include San Francisco Bay (bay) and the adjacent Sacramento–San Joaquin River Delta (delta). The U.S. Geological Survey (USGS) has operated a high-frequency (15-minute sampling interval) water-quality monitoring network in San Francisco Bay since the late 1980s (Buchanan and others, 2014). This network includes 19 stations at which sustained measurements have been made in the bay; currently, 8 stations are in operation (fig. 1). All eight stations are equipped with specific conductance (which can be related to salinity) and water-temperature sensors. Water quality in the bay constantly changes as ocean tides force seawater in and out of the bay, and river inflows—the most significant coming from the delta—vary on time scales ranging from those associated with storms to multiyear droughts. This monitoring network was designed to observe and characterize some of these changes in the bay across space and over time. The data demonstrate a high degree of variability in both specific conductance and temperature at time scales from tidal to annual and also reveal longer-term changes that are likely to influence overall environmental health in the bay.In water year (WY) 2015 (October 1, 2014, through September 30, 2015), as in the preceding water year (Downing-Kunz and others, 2015), the high-frequency measurements revealed record-high values of specific conductance and water temperature at several stations during a period of reduced freshwater inflow from the delta and other tributaries because of persistent, severe drought conditions in California. This report briefly summarizes observations for WY 2015 and compares them to previous years that had different levels of freshwater inflow.

  1. Design concept of the high performance light water reactor

    Energy Technology Data Exchange (ETDEWEB)

    Schulenberg, Thomas; Starflinger, Joerg [Forschungszentrum Karlsruhe GmbH Technik und Umwelt (Germany). Inst. for Nuclear and Energy Technologies; Bittermann, Dietmar [AREVA NP GmbH, Erlangen (Germany). NEP-G Process

    2009-04-15

    The 'High Performance Light Water Reactor' (HPLWR) is a Light Water Reactor operating with supercritical water as coolant. At a pressure of 25 MPa in the core, water is heated up from 280 to 500 C. For these conditions, the envisaged net plant efficiency is 43.5%. The core design concept is based on a so-called '3-pass-core' in which the coolant is heated up in three subsequent steps. After each step, the coolant is mixed avoiding hot streaks possibly leading to unacceptable wall temperatures. The design of such a core comprises fuel assemblies containing 40 fuel rods and an inner and outer box for a better neutron moderation. Nine of these are assembled to a cluster with common head- and foot piece. The coolant is mixed inside an upper and inside a lower mixing chamber and leaves the reactor pressure vessel through a co-axial pipe, which protects the vessel wall against too high temperatures. (orig.)

  2. STUDY OF HIGH RATE SEDIMENTATION TANK IN WATER TREATMENT PLANTS

    Directory of Open Access Journals (Sweden)

    M.R SHA MANSOURI

    2001-06-01

    Full Text Available Introduction: Sedimentation is considered as an important process in removing turbidity produced in water and wastewater plants. Gravity sedimentation is usually the first method considered in water treatment system. However, required overflow rates (OFRs to remove turbidity in the conventional clarifiers are too low. Therefore, the shallow depth sedimentation concept was studied remove turbidity in order to increase OFRs of gravity setting equipment. Methods: Using a pilot with parallel plates with effect area 1.5 m2 and 1.5 m depth. The independent parameters such as OFRs, sludge concentration and turbidity were evaluated for turbidity removal. The pilot is located in Isfahan Water Treatment Plant. Results: The efficacy of pilot for turbidity 10-50 NTU is equal to 50 percent (P<0.01. The maximum removal efficiency at sludge concentration 270 ml/lit was obtained (P<0.01. A nonlinear relationship exists between removal efficiency (TR%, sludge concentration (Sc over flowrates (OFR and influent turbidity (Tu in pilot. Discussion: By using high rate sedimentation tank in water treatment plant, detection time reduced from 3 hours to 20-30 minute, turbidity removal increased up to 30 percent in compare with conventional sedimentation. Also, it has economic benefits and high efficiency.

  3. Psychology Educators of Tennessee (PET): A Regional Learning Community for Psychology Teachers

    Science.gov (United States)

    Kelly, Kiesa; Jones, Linda; Brinthaupt, Thomas M.; Hart, Wendy

    2016-01-01

    This paper describes the development of a regional psychology teaching organisation, Psychology Educators of Tennessee (PET). PET is designed to enhance collaboration among teachers from local colleges, universities, and high schools. We discuss the history of PET, the themes and pragmatics associated with our annual conference, plans for…

  4. Value of C-11-methionine PET in imaging brain tumours and metastases

    NARCIS (Netherlands)

    Glaudemans, Andor W J M; Enting, Roeline; Heesters, Martinus; Dierckx, Rudi A J O; van Rheenen, Ronald W J; Walenkamp, Annemiek M E; Slart, Riemer H J A

    C-11-methionine (MET) is the most popular amino acid tracer used in PET imaging of brain tumours. Because of its characteristics, MET PET provides a high detection rate of brain tumours and good lesion delineation. This review focuses on the role of MET PET in imaging cerebral gliomas. The

  5. Additive value of amyloid-PET in routine cases of clinical dementia work-up after FDG-PET.

    Science.gov (United States)

    Brendel, Matthias; Schnabel, Jonas; Schönecker, Sonja; Wagner, Leonie; Brendel, Eva; Meyer-Wilmes, Johanna; Unterrainer, Marcus; Schildan, Andreas; Patt, Marianne; Prix, Catharina; Ackl, Nibal; Catak, Cihan; Pogarell, Oliver; Levin, Johannes; Danek, Adrian; Buerger, Katharina; Bartenstein, Peter; Barthel, Henryk; Sabri, Osama; Rominger, Axel

    2017-12-01

    In recent years, several [18F]-labeled amyloid-PET tracers have been developed and have obtained clinical approval. Despite their widespread scientific use, studies in routine clinical settings are limited. We therefore investigated the impact of [18F]-florbetaben (FBB)-PET on the diagnostic management of patients with suspected dementia that was still unclarified after [18F]-fluordeoxyglucose (FDG)-PET. All subjects were referred in-house with a suspected dementia syndrome due to neurodegenerative disease. After undergoing an FDG-PET exam, the cases were discussed by the interdisciplinary dementia board, where the most likely diagnosis as well as potential differential diagnoses were documented. Because of persistent diagnostic uncertainty, the patients received an additional FBB-PET exam. Results were interpreted visually and classified as amyloid-positive or amyloid-negative, and we then compared the individual clinical diagnoses before and after additional FBB-PET. A total of 107 patients (mean age 69.4 ± 9.7y) were included in the study. The FBB-PET was rated as amyloid-positive in 65/107. In 83% of the formerly unclear cases, a final diagnosis was reached through FBB-PET, and the most likely prior diagnosis was changed in 28% of cases. The highest impact was observed for distinguishing Alzheimer's dementia (AD) from fronto-temporal dementia (FTLD), where FBB-PET altered the most likely diagnosis in 41% of cases. FBB-PET has a high additive value in establishing a final diagnosis in suspected dementia cases when prior investigations such as FDG-PET are inconclusive. The differentiation between AD and FTLD was particularly facilitated by amyloid-PET, predicting a considerable impact on patient management, especially in the light of upcoming disease-modifying therapies.

  6. Experiments on aerosol removal by high-pressure water spray

    Energy Technology Data Exchange (ETDEWEB)

    Corno, Ada del, E-mail: delcorno@rse-web.it [RSE, Power Generation Technologies and Materials Dept, via Rubattino 54, I-20134 Milano (Italy); Morandi, Sonia, E-mail: morandi@rse-web.it [RSE, Power Generation Technologies and Materials Dept, via Rubattino 54, I-20134 Milano (Italy); Parozzi, Flavio, E-mail: parozzi@rse-web.it [RSE, Power Generation Technologies and Materials Dept, via Rubattino 54, I-20134 Milano (Italy); Araneo, Lucio, E-mail: lucio.araneo@polimi.it [Politecnico di Milano, Department of Energy, via Lambruschini 4A, I-20156 Milano (Italy); CNR-IENI, via Cozzi 53, I-20125 Milano (Italy); Casella, Francesco, E-mail: francesco2.casella@mail.polimi.it [Politecnico di Milano, Department of Energy, via Lambruschini 4A, I-20156 Milano (Italy)

    2017-01-15

    Highlights: • Experimental research to measure the efficiency of high-pressure sprays in capturing aerosols if applied to a filtered containment venting system in case of severe accident. • Cloud of monodispersed SiO{sub 2} particles with sizes 0.5 or 1.0 μm and initial concentration in the range 2–90 mg/m{sup 3}. • Carried out in a chamber 0.5 × 1.0 m and 1.5 m high, with transparent walls equipped with a high pressure water spray with single nozzle. • Respect to low-pressure sprays, removal efficiency turned out significant: the half-life for 1 μm particles with a removal high-pressure spray system is orders of magnitude shorter than that with a low-pressure sprays system. - Abstract: An experimental research was managed in the framework of the PASSAM European Project to measure the efficiency of high-pressure sprays in capturing aerosols when applied to a filtered containment venting system in case of severe accident. The campaign was carried out in a purposely built facility composed by a scrubbing chamber 0.5 × 1.0 m and 1.5 m high, with transparent walls to permit the complete view of the aerosol removal process, where the aerosol was injected to form a cloud of specific particle concentration. The chamber was equipped with a high pressure water spray system with a single nozzle placed on its top. The test matrix consisted in the combination of water pressure injections, in the range 50–130 bar, on a cloud of monodispersed SiO{sub 2} particles with sizes 0.5 or 1.0 μm and initial concentration ranging between 2 and 99 mg/m{sup 3}. The spray was kept running for 2 min and the efficiency of the removal was evaluated, along the test time, using an optical particle sizer. With respect to low-pressure sprays, the removal efficiency turned out much more significant: the half-life for 1 μm particles with a removal high-pressure spray system is orders of magnitude shorter than that with a low-pressure spray system. The highest removal rate was

  7. Low background and high contrast PET imaging of amyloid-{beta} with [{sup 11}C]AZD2995 and [{sup 11}C]AZD2184 in Alzheimer's disease patients

    Energy Technology Data Exchange (ETDEWEB)

    Forsberg, Anton; Andersson, Jan; Varnaes, Katarina; Halldin, Christer [Karolinska Institutet, Centre for Psychiatry Research, Department of Clinical Neuroscience, Stockholm (Sweden); Jureus, Anders; Swahn, Britt-Marie; Sandell, Johan; Julin, Per; Svensson, Samuel [AstraZeneca Research and Development, Neuroscience Research and Therapy Area, Soedertaelje (Sweden); Cselenyi, Zsolt; Schou, Magnus; Johnstroem, Peter; Farde, Lars [Karolinska Institutet, Centre for Psychiatry Research, Department of Clinical Neuroscience, Stockholm (Sweden); Karolinska Hospital, AstraZeneca Translational Sciences Centre, PET CoE, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm (Sweden); Eriksdotter, Maria; Freund-Levi, Yvonne [Karolinska Institutet, Clinical Geriatrics, Department of Neurobiology, Care Sciences and Society, Stockholm (Sweden); Karolinska University Hospital, Department of Geriatric Medicine, Stockholm (Sweden); Jeppsson, Fredrik [AstraZeneca Research and Development, Neuroscience Research and Therapy Area, Soedertaelje (Sweden); Karolinska Institutet, Science for Life Laboratory, Division of Translational Medicine and Chemical Biology, Department of Medical Biochemistry and Biophysics, Stockholm (Sweden)

    2013-04-15

    The aim of this study was to evaluate AZD2995 side by side with AZD2184 as novel PET radioligands for imaging of amyloid-{beta} in Alzheimer's disease (AD). In vitro binding of tritium-labelled AZD2995 and AZD2184 was studied and compared with that of the established amyloid-{beta} PET radioligand PIB. Subsequently, a first-in-human in vivo PET study was performed using [{sup 11}C]AZD2995 and [{sup 11}C]AZD2184 in three healthy control subjects and seven AD patients. AZD2995, AZD2184 and PIB were found to share the same binding site to amyloid-{beta}. [{sup 3}H]AZD2995 had the highest signal-to-background ratio in brain tissue from patients with AD as well as in transgenic mice. However, [{sup 11}C]AZD2184 had superior imaging properties in PET, as shown by larger effect sizes comparing binding potential values in cortical regions of AD patients and healthy controls. Nevertheless, probably due to a lower amount of nonspecific binding, the group separation of the distribution volume ratio values of [{sup 11}C]AZD2995 was greater in areas with lower amyloid-{beta} load, e.g. the hippocampus. Both AZD2995 and AZD2184 detect amyloid-{beta} with high affinity and specificity and also display a lower degree of nonspecific binding than that reported for PIB. Overall [{sup 11}C]AZD2184 seems to be an amyloid-{beta} radioligand with higher uptake and better group separation when compared to [{sup 11}C]AZD2995. However, the very low nonspecific binding of [{sup 11}C]AZD2995 makes this radioligand potentially interesting as a tool to study minute levels of amyloid-{beta}. This sensitivity may be important in investigating, for example, early prodromal stages of AD or in the longitudinal study of a disease modifying therapy. (orig.)

  8. Unexpected response of high Alpine Lake waters to climate warming.

    Science.gov (United States)

    Thies, Hansjörg; Nickus, Ulrike; Mair, Volkmar; Tessadri, Richard; Tait, Danilo; Thaler, Bertha; Psenner, Roland

    2007-11-01

    Over the past two decades, we have observed a substantial rise in solute concentration at two remote high mountain lakes in catchments of metamorphic rocks in the European Alps. At Rasass See, the electrical conductivity increased 18-fold. Unexpectedly high nickel concentrations at Rasass See, which exceeded the limit in drinking water by more than 1 order of magnitude, cannot be related to catchment geology. We attribute these changes in lake water quality to solute release from the ice of an active rock glacier in the catchment as a response to climate warming. Similar processes occurred at the higher elevation lake Schwarzsee ob Sölden, where electrical conductivity has risen 3-fold during the past two decades.

  9. High Speed Water Sterilization Using One-Dimensional Nanostructures

    KAUST Repository

    Schoen, David T.

    2010-09-08

    The removal of bacteria and other organisms from water is an extremely important process, not only for drinking and sanitation but also industrially as biofouling is a commonplace and serious problem. We here present a textile based multiscale device for the high speed electrical sterilization of water using silver nanowires, carbon nanotubes, and cotton. This approach, which combines several materials spanning three very different length scales with simple dying based fabrication, makes a gravity fed device operating at 100000 L/(h m2) which can inactivate >98% of bacteria with only several seconds of total incubation time. This excellent performance is enabled by the use of an electrical mechanism rather than size exclusion, while the very high surface area of the device coupled with large electric field concentrations near the silver nanowire tips allows for effective bacterial inactivation. © 2010 American Chemical Society.

  10. High-risk plaque features can be detected in non-stenotic carotid plaques of patients with ischaemic stroke classified as cryptogenic using combined {sup 18}F-FDG PET/MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Hyafil, Fabien [Technische Universitaet Muenchen, Department of Nuclear Medicine, Klinikum rechts der Isar, Munich (Germany); Bichat University Hospital, Department of Nuclear Medicine, Paris (France); Schindler, Andreas; Obenhuber, Tilman; Saam, Tobias [Ludwig Maximilians University Hospital Munich, Institute for Clinical Radiology, Munich (Germany); Sepp, Dominik; Hoehn, Sabine; Poppert, Holger [Technische Universitaet Muenchen, Department of Neurology, Klinikum rechts der Isar, Munich (Germany); Bayer-Karpinska, Anna [Ludwig Maximilians University Hospital Munich, Institute for Stroke and Dementia Research, Munich (Germany); Boeckh-Behrens, Tobias [Technische Universitaet Muenchen, Department of Neuroradiology, Klinikum Rechts der Isar, Munich (Germany); Hacker, Marcus [Medical University of Vienna, Division of Nuclear Medicine, Department of Biomedical Imaging and Image-guided Therapy, Vienna (Austria); Nekolla, Stephan G. [Technische Universitaet Muenchen, Department of Nuclear Medicine, Klinikum rechts der Isar, Munich (Germany); Partner Site Munich Heart Alliance, German Centre for Cardiovascular Research (DZHK), Munich (Germany); Rominger, Axel [Ludwig Maximilians University Hospital Munich, Department of Nuclear Medicine, Munich (Germany); Dichgans, Martin [Technische Universitaet Muenchen, Department of Neurology, Klinikum rechts der Isar, Munich (Germany); Munich Cluster of Systems Neurology (SyNergy), Munich (Germany); Schwaiger, Markus [Technische Universitaet Muenchen, Department of Nuclear Medicine, Klinikum rechts der Isar, Munich (Germany)

    2016-02-15

    The aim of this study was to investigate in 18 patients with ischaemic stroke classified as cryptogenic and presenting non-stenotic carotid atherosclerotic plaques the morphological and biological aspects of these plaques with magnetic resonance imaging (MRI) and {sup 18}F-fluoro-deoxyglucose positron emission tomography ({sup 18}F-FDG PET) imaging. Carotid arteries were imaged 150 min after injection of {sup 18}F-FDG with a combined PET/MRI system. American Heart Association (AHA) lesion type and plaque composition were determined on consecutive MRI axial sections (n = 460) in both carotid arteries. {sup 18}F-FDG uptake in carotid arteries was quantified using tissue to background ratio (TBR) on corresponding PET sections. The prevalence of complicated atherosclerotic plaques (AHA lesion type VI) detected with high-resolution MRI was significantly higher in the carotid artery ipsilateral to the ischaemic stroke as compared to the contralateral side (39 vs 0 %; p = 0.001). For all other AHA lesion types, no significant differences were found between ipsilateral and contralateral sides. In addition, atherosclerotic plaques classified as high-risk lesions with MRI (AHA lesion type VI) were associated with higher {sup 18}F-FDG uptake in comparison with other AHA lesions (TBR = 3.43 ± 1.13 vs 2.41 ± 0.84, respectively; p < 0.001). Furthermore, patients presenting at least one complicated lesion (AHA lesion type VI) with MRI showed significantly higher {sup 18}F-FDG uptake in both carotid arteries (ipsilateral and contralateral to the stroke) in comparison with carotid arteries of patients showing no complicated lesion with MRI (mean TBR = 3.18 ± 1.26 and 2.80 ± 0.94 vs 2.19 ± 0.57, respectively; p < 0.05) in favour of a diffuse inflammatory process along both carotid arteries associated with complicated plaques. Morphological and biological features of high-risk plaques can be detected with {sup 18}F-FDG PET/MRI in non-stenotic atherosclerotic plaques ipsilateral

  11. High Water Marks in Hedge Fund Management Contracts

    OpenAIRE

    Sevostiyanova, Margarita

    2012-01-01

    The thesis provides a theoretical rationale for the inclusion of high water mark (HWM) provisions in hedge fund management contracts. The results show (i) fund managers with better information about future fund profitability, have more incentives to efficiently close the fund it contracts include HWMs. (ii) Contracts with HWMs cause fund managers to smooth performance. HWMs provide both the incentive to underreport returns in good times as well as to overreport returns during difficult periods.

  12. Furrow Dike Water Conservation Practices in the Texas High Plains

    OpenAIRE

    Wistrand, Glen L.

    1984-01-01

    Furrow diking can prevent irrigation and rainfall runoff, conserve energy use, prevent soil loss, amd allow producers to reclaim land otherwise unusable, depending on soil, climate, and crops grown in a given area. Initial investment to use this technique may be recovered within the first season. This study analyzes the effects of diking on water and soil conservation, crop yields, costs, and energy use in farming, using examples of farms in the Texas High Plains area.

  13. Reverse osmosis membrane of high urea rejection properties. [water purification

    Science.gov (United States)

    Johnson, C. C.; Wydeven, T. J. (Inventor)

    1980-01-01

    Polymeric membranes suitable for use in reverse osmosis water purification because of their high urea and salt rejection properties are prepared by generating a plasma of an unsaturated hydrocarbon monomer and nitrogen gas from an electrical source. A polymeric membrane is formed by depositing a polymer of the unsaturated monomer from the plasma onto a substrate, so that nitrogen from the nitrogen gas is incorporated within the polymer in a chemically combined form.

  14. Caecilians exhibit cutaneous respiration and high evaporative water ...

    African Journals Online (AJOL)

    Caecilians exhibit cutaneous respiration and high evaporative water loss. W.K. Steele, G.N. Louw. Abstract. Scolecomorphus kirki het 'n gemiddelde rustende VO2 van 0,052 ± 0,009 ml O2 g-1 h by 20% rh en 20°C. Die gemiddelde RK was 1,06 en 54,5% van die totale CO2-produksie het deur die vel verlore gegaan.

  15. Induced radioactivity of a GSO scintillator by secondary fragments in carbon ion therapy and its effects on in-beam OpenPET imaging.

    Science.gov (United States)

    Hirano, Yoshiyuki; Nitta, Munetaka; Nishikido, Fumihiko; Yoshida, Eiji; Inadama, Naoko; Yamaya, Taiga

    2016-07-07

    The accumulation of induced radioactivity within in-beam PET scanner scintillators is of concern for its long-term clinical usage in particle therapy. To estimate the effects on OpenPET which we are developing for in-beam PET based on GSOZ (Zi doped Gd2SiO5), we measured the induced radioactivity of GSO activated by secondary fragments in a water phantom irradiation by a (12)C beam with an energy of 290 MeV u(-1). Radioisotopes of Na, Ce, Eu, Gd, Nd, Pm and Tb including positron emitters were observed in the gamma ray spectra of the activated GSO with a high purity Ge detector and their absolute radioactivities were calculated. We used the Monte Carlo simulation platform, Geant4 in which the observed radioactivity was assigned to the scintillators of a precisely reproduced OpenPET and the single and coincidence rates immediately after one treatment and after one-year usage were estimated for the most severe conditions. Comparing the highest coincidence rate originating from the activated scintillators (background) and the expected coincidence rate from an imaging object (signal), we determined the expected signal-to-noise ratio to be more than 7 within 3 min and more than 10 within 1 min from the scan start time. We concluded the effects of scintillator activation and their accumulation on the OpenPET imaging were small and clinical long-term usage of the OpenPET was feasible.

  16. High prevalence of enteric viruses in untreated individual drinking water sources and surface water in Slovenia.

    Science.gov (United States)

    Steyer, Andrej; Torkar, Karmen Godič; Gutiérrez-Aguirre, Ion; Poljšak-Prijatelj, Mateja

    2011-09-01

    Waterborne infections have been shown to be important in outbreaks of gastroenteritis throughout the world. Although improved sanitary conditions are being progressively applied, fecal contaminations remain an emerging problem also in developed countries. The aim of our study was to investigate the prevalence of fecal contaminated water sources in Slovenia, including surface waters and groundwater sources throughout the country. In total, 152 water samples were investigated, of which 72 samples represents groundwater from individual wells, 17 samples from public collection supplies and 63 samples from surface stream waters. Two liters of untreated water samples were collected and concentrated by the adsorption/elution technique with positively charged filters followed by an additional ultracentrifugation step. Group A rotaviruses, noroviruses (genogroups I and II) and astroviruses were detected with real-time RT-PCR method in 69 (45.4%) out of 152 samples collected, of which 31/89 (34.8%) drinking water and 38/63 (60.3%) surface water samples were positive for at least one virus tested. In 30.3% of drinking water samples group A rotaviruses were detected (27/89), followed by noroviruses GI (2.2%; 2/89) and astroviruses (2.2%; 2/89). In drinking groundwater samples group A rotaviruses were detected in 27 out of 72 tested samples (37.5%), genogroup I noroviruses in two (2.8%), and human astroviruses in one (1.4%) samples. In surface water samples norovirus genogroup GII was the most frequently detected (41.3%; 26/63), followed by norovirus GI (33.3%; 21/63), human astrovirus (27.0%; 17/63) and group A rotavirus (17.5%; 11/63). Our study demonstrates relatively high percentage of groundwater contamination in Slovenia and, suggests that raw groundwater used as individual drinking water supply may constitute a possible source of enteric virus infections. In the future, testing for enteric viruses should be applied for drinking water sources in waterborne outbreaks

  17. The fabrication of microelectrode array biochip on PET using plate-to-plate NIL

    Science.gov (United States)

    Beh, Khi Khim; Samsuri, Fahmi; Lee, Lai Seng; Ooi, Su Guan; Ong, Wei Jie; Mohamed, Khairudin

    2017-07-01

    Polyethylene terephthalate (PET) films are useful for various applications due to the characterization of PET were flexibility, thermal resistance and chemical resistant. PET Films are widely used in both commercial and industrial today since they are highly demand in the market. In this study, microelectrode array biochip was fabricated on flexible PET film using (plate-to-plate) nanoimprint lithography (NIL). The PET films acted as substrate while PDMS as the mould. The Polydimethylsiloxane (PDMS) mould was attached on top of the PET film and additionally clamped between two pieces of glass. A mild force was applied to it for REM (replica moulding). A study was carried out upon the surface profiling of the PDMS mould and PET to monitor the possibility of deformation after applying force upon the samples. The experiment shall present the finding of required force to REM the microelectrode array biochip pattern on the PET film.

  18. High-Performance Supported Iridium Oxohydroxide Water Oxidation Electrocatalysts.

    Science.gov (United States)

    Massué, Cyriac; Pfeifer, Verena; Huang, Xing; Noack, Johannes; Tarasov, Andrey; Cap, Sébastien; Schlögl, Robert

    2017-05-09

    The synthesis of a highly active and yet stable electrocatalyst for the anodic oxygen evolution reaction (OER) remains a major challenge for acidic water splitting on an industrial scale. To address this challenge, we obtained an outstanding high-performance OER catalyst by loading Ir on conductive antimony-doped tin oxide (ATO)-nanoparticles by a microwave (MW)-assisted hydrothermal route. The obtained Ir phase was identified by using XRD as amorphous (XRD-amorphous), highly hydrated IrIII/IV oxohydroxide. To identify chemical and structural features responsible for the high activity and exceptional stability under acidic OER conditions with loadings as low as 20 μgIr  cm-2 , we used stepwise thermal treatment to gradually alter the XRD-amorphous Ir phase by dehydroxylation and crystallization of IrO2 . This resulted in dramatic depletion of OER performance, indicating that the outstanding electrocatalytic properties of the MW-produced IrIII/IV oxohydroxide are prominently linked to the nature of the produced Ir phase. This finding is in contrast with the often reported stable but poor OER performance of crystalline IrO2 -based compounds produced through more classical calcination routes. Our investigation demonstrates the immense potential of Ir oxohydroxide-based OER electrocatalysts for stable high-current water electrolysis under acidic conditions. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Quantitation of regional cerebral blood flow corrected for partial volume effect using O-15 water and PET: I. Theory, error analysis, and stereologic comparison

    DEFF Research Database (Denmark)

    Lida, H; Law, I; Pakkenberg, B

    2000-01-01

    Limited spatial resolution of positron emission tomography (PET) can cause significant underestimation in the observed regional radioactivity concentration (so-called partial volume effect or PVE) resulting in systematic errors in estimating quantitative physiologic parameters. The authors have...... in the corresponding ROIs. Reproducibility of the estimated parameters and sensitivity to various error sources were also evaluated. All models tested in the current study yielded PVE-corrected regional CBF values (approximately 0.8 mL x min(-1) x g(-1) for models with a term for gray matter tissue and 0.5 mL x min(-1...... that included two parallel tissue compartments demonstrated better results with regards to the agreement of tissue time-activity curve and the Akaike's Information Criteria. Error sensitivity analysis suggested the model that fits three parameters of the gray matter CBF, the gray matter fraction, and the white...

  20. Musculoskeletal imaging using fluoride PET.

    Science.gov (United States)

    Fischer, Dorothee Rita

    2013-11-01

    The convenience of (18)F-fluoride imaging is undeniable both because of its favorable tracer and because of its technical characteristics, including high image quality and short examination times leading to increased patient comfort. Depending on the activity administered, the radiation dose to patients is about comparable to higher using (18)F-fluoride for bone imaging compared with conventional scintigraphy using 99mTc-methylene diphosphonate. In times of molybdenum shortage, (18)F-fluoride represents a good alternative to 99mTc-based bone tracers. Besides malignant skeletal disease(18)F-fluoride PET/CT has in the last decade been investigated in a variety of non-oncologic musculoskeletal disorders of all parts of the skeleton. Studies included imaging of the skull with a special focus on bisphosphonate-induced osteonecrosis of the jaw in patients treated with bisphosphonates due to benign or malignant bone changes. Further studies evaluated the appendicular skeleton with emphasis on postsurgical changes including patients after knee and hip surgery and patients having received bone grafts of their limbs. Also, therapeutic effect of (18)F-fluoride PET/CT on patients with unclear foot pain was investigated. Finally imaging of the axial skeleton was analyzed including patients with ankylosing spondylitis and with Paget disease as well as patients after spine surgery including assessment of cage incorporation after cervical and lumbar spine fusion surgery. Furthermore, children suspected of child abuse as well as young patients with back pain were investigated by either (18)F-fluoride PET or PET/CT. Regarding its favorable technical aspects as well as study results presented, it is imaginable that (18)F-fluoride PET/(CT) will be increasingly used for non-oncologic musculoskeletal imaging in the future either as an adjunct or alternative to so far established imaging modalities and seems to be promising regarding decision making in the therapeutic management of

  1. PET application in psychiatry and psychopharmacology

    Energy Technology Data Exchange (ETDEWEB)

    Suhara, Tetsuya [National Inst. of Radiological Sciences, Chiba (Japan)

    1999-07-01

    In the last few decades diagnostic and research tools in the medical field have made great advances, yet psychiatry has lacked sufficiently sensitive tools to measure the aberration of brain functions. Recently however, the development of Positron emission tomography (PET) techniques has made it possible to measure changes in neurochemical components in mental disorders and the effect of psychoactive drugs in living human brain. Most of the advancement in the psychiatric field has came from the development psychoactive drugs. Brain research involving identification of neurotransmission is largely based on compounds developed in psychopharmacology. Some of these compounds have been radiolabelled and used as radioligands for quantitative examination of neuroreceptors and other aspects of neurotransmission. Using PET, radioligand binding can now be examined in the human brain in vivo. PET techniques also allow examination of an unlabelled drug by examination of its interaction with a radioligand. So one potential of PET in psychiatry is to investigate the mechanism of psychoactive drugs. Antidepressants modulate serotonin transmission by inhibiting serotonin reuptake from the synaptic cleft. High affinity [{sup 3}H]imipramine binding sites in mammalian brain have been labelled to investigate serotonin transporters in living human brain by PET. Cyanoimipramine which is described as a potent serotonin reuptake inhibitor, was labelled with {sup 11}C. In a PET experiment with 6 healthy human subjects, a high accumulation of [{sup 11}C]cyanoimipramine was found in the thalamus and striatum and lowest accumulation was observed in the cerebellum, a region relatively void of serotonin transporters. The thalamus to cerebellum ratio was about 2 at 90 min after the injection of the tracer. Recently, [{sup 11}C]McN5652-X has been introduced as a better tracer for serotonin transporter imaging. Employing [{sup 11}C]McN5652-X in a PET study of 7 healthy human subjects, a high

  2. Image quality assesment using NEMA NU 4/2008 standards in small animal PET scanner

    Energy Technology Data Exchange (ETDEWEB)

    Gontijo, Rodrigo M.G.; Ferreira, Andréa V.; Silva, Juliana B.; Mamede, Marcelo, E-mail: rodrigo.gontijo@cdtn.br, E-mail: rodrigogadelhagontijo1@hotmail.com [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2017-07-01

    In Brazil, there are few micro PET in use and a quality control protocols standardization are needed to harmonize their use in the research field. Thus, the purpose of this study is to characterize the image quality performance of the micro PET scanner (Lab PET 4, GE healthcare Technologies, Waukesha, WI) using the NEMA NU 4/ 2008 standards and specific phantom. The NEMA image-quality (IQ) phantom consists of 3 different regions to analyze distinct characteristics: image noise (%SD), expressed as percentage SD in a uniform region (%SD), recovery coefficient (RC) and Spill-over (SOR) in air and water. The IQ phantom was filled with {sup 18}F-FDG calibrated at the beginning of acquisition, placed in the center of the field-of-view (FOV) and measured with the typical whole body imaging protocol. The images were reconstructed with different reconstruction methods (FBP-2D; MLEM-3D and OSEM-3D); with and without high resolution (HR) when possible. The results were compared. The LabPET 4 system produces appropriate image and with performance according to the literature. The present study is an initial step to verify the NEMA NU 4/2008 use in the Brazilian scenario for further standardization. (author)

  3. COMPANION ANIMALS SYMPOSIUM: Rendered ingredients significantly influence sustainability, quality, and safety of pet food.

    Science.gov (United States)

    Meeker, D L; Meisinger, J L

    2015-03-01

    The rendering industry collects and safely processes approximately 25 million t of animal byproducts each year in the United States. Rendering plants process a variety of raw materials from food animal production, principally offal from slaughterhouses, but include whole animals that die on farms or in transit and other materials such as bone, feathers, and blood. By recycling these byproducts into various protein, fat, and mineral products, including meat and bone meal, hydrolyzed feather meal, blood meal, and various types of animal fats and greases, the sustainability of food animal production is greatly enhanced. The rendering industry is conscious of its role in the prevention of disease and microbiological control and providing safe feed ingredients for livestock, poultry, aquaculture, and pets. The processing of otherwise low-value OM from the livestock production and meat processing industries through rendering drastically reduces the amount of waste. If not rendered, biological materials would be deposited in landfills, burned, buried, or inappropriately dumped with large amounts of carbon dioxide, ammonia, and other compounds polluting air and water. The majority of rendered protein products are used as animal feed. Rendered products are especially valuable to the livestock and pet food industries because of their high protein content, digestible AA levels (especially lysine), mineral availability (especially calcium and phosphorous), and relatively low cost in relation to their nutrient value. The use of these reclaimed and recycled materials in pet food is a much more sustainable model than using human food for pets.

  4. In-beam PET measurement of $^{7}Li^{3+}$ irradiation induced $\\beta^+}$-activity

    CERN Document Server

    Priegnitz, M; Parodi, K; Sommerer, F; Fiedler, F; Enghardt, W

    2008-01-01

    At present positron emission tomography (PET) is the only feasible method of an in situ and non-invasive monitoring of patient irradiation with ions. At the experimental carbon ion treatment facility of the Gesellschaft für Schwerionenforschung (GSI) Darmstadt an in-beam PET scanner has been integrated into the treatment site and lead to a considerable quality improvement of the therapy. Since ions other than carbon are expected to come into operation in future patient treatment facilities, it is highly desirable to extend in-beam PET also to other therapeutic relevant ions, e.g. 7Li. Therefore, by means of the in-beam PET scanner at GSI the β+-activity induced by 7Li3+ ions has been investigated for the first time. Targets of PMMA, water, graphite and polyethylene were irradiated with monoenergetic, pencil-like beams of 7Li3+ with energies between 129.1 A MeV and 205.3 A MeV and intensities ranging from 3.0 × 107 to 1.9 × 108 ions s−1. This paper presents the measured β+-activity profiles as well as d...

  5. Comparison of integrated whole-body [11C]choline PET/MR with PET/CT in patients with prostate cancer.

    Science.gov (United States)

    Souvatzoglou, Michael; Eiber, Matthias; Takei, Toshiki; Fürst, Sebastian; Maurer, Tobias; Gaertner, Florian; Geinitz, Hans; Drzezga, Alexander; Ziegler, Sibylle; Nekolla, Stephan G; Rummeny, Ernst J; Schwaiger, Markus; Beer, Ambros J

    2013-10-01

    To evaluate the performance of conventional [(11)C]choline PET/CT in comparison to that of simultaneous whole-body PET/MR. The study population comprised 32 patients with prostate cancer who underwent a single-injection dual-imaging protocol with PET/CT and subsequent PET/MR. PET/CT scans were performed applying standard clinical protocols (5 min after injection of 793 ± 69 MBq [(11)C]choline, 3 min per bed position, intravenous contrast agent). Subsequently (52 ± 15 min after injection) PET/MR was performed (4 min per bed position). PET images were reconstructed iteratively (OSEM 3D), scatter and attenuation correction of emission data and regional allocation of [(11)C]choline foci were performed using CT data for PET/CT and segmented Dixon MR, T1 and T2 sequences for PET/MR. Image quality of the respective PET scans and PET alignment with the respective morphological imaging modality were compared using a four point scale (0-3). Furthermore, number, location and conspicuity of the detected lesions were evaluated. SUVs for suspicious lesions, lung, liver, spleen, vertebral bone and muscle were compared. Overall 80 lesions were scored visually in 29 of the 32 patients. There was no significant difference between the two PET scans concerning number or conspicuity of the detected lesions (p not significant). PET/MR with T1 and T2 sequences performed better than PET/CT in anatomical allocation of lesions (2.87 ± 0.3 vs. 2.72 ± 0.5; p = 0.005). The quality of PET/CT images (2.97 ± 0.2) was better than that of the respective PET scan of the PET/MR (2.69 ± 0.5; p = 0.007). Overall the maximum and mean lesional SUVs exhibited high correlations between PET/CT and PET/MR (ρ = 0.87 and ρ = 0.86, respectively; both p bone and pelvis. These promising findings suggest that [(11)C]choline PET/MR might have a diagnostic benefit compared to PET/CT in patients with prostate cancer, and now needs to be further evaluated in prospective trials.

  6. A comparison of reactive plasma pre-treatments on PET substrates by Cu and Ti pulsed-DC and HIPIMS discharges

    Energy Technology Data Exchange (ETDEWEB)

    Audronis, M., E-mail: m.audronis@yahoo.co.uk [Gencoa Ltd, Physics Road, Speke, Liverpool, L24 9HP (United Kingdom); Hinder, S.J. [The Surface Analysis Laboratory, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford, GU2 7XH (United Kingdom); Mack, P. [ThermoFisher Scientific Ltd, Imberhorne Lane, East Grinstead, Sussex, RH19 1UB (United Kingdom); Bellido-Gonzalez, V. [Gencoa Ltd, Physics Road, Speke, Liverpool, L24 9HP (United Kingdom); Bussey, D.; Matthews, A. [Department of Engineering Materials, University of Sheffield, Sheffield S1 3JD (United Kingdom); Baker, M.A. [The Surface Analysis Laboratory, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford, GU2 7XH (United Kingdom)

    2011-12-30

    PET web samples have been treated by magnetically enhanced glow discharges powered using either medium frequency pulse direct current (p-DC) or low frequency high power pulse (HIPIMS) sources. The plasma pre-treatment processes were carried out in an Ar-O{sub 2} atmosphere using either Cu or Ti sputter targets. XPS, AFM and sessile drop water contact angle measurements have been employed to examine changes in surface chemistry and morphology for different pre-treatment process parameters. Deposition of metal oxide onto the PET surface is observed as a result of the sputter magnetron-based glow discharge web treatment. Using the Cu target, both the p-DC and HIPIMS processes result in the formation of a thin CuO layer (with a thickness between 1 and 11 nm) being deposited onto the PET surface. Employing the Ti target, both p-DC and HIPIMS processes give rise to a much lower concentration of Ti (< 5 at.%), in the form of TiO{sub 2} on the PET treated surface. The TiO{sub 2} is probably distributed as an island-like distribution covering the PET surface. Presence of Cu and Ti oxide constituents on the treated PET is beneficial in aiding the adhesion but alone (i.e. without oxygen plasma activation) is not enough to provide very high levels of hydrophilicity as is clear from sessile drop water contact angle measurements on aged samples. Exposure to the plasma treatments leads to a small amount of roughening of the substrate surface, but the average surface roughness in all cases is below 2.5 nm. The PET structure at the interface with a coating is mostly or wholly preserved. The oxygen plasma treatment, metal oxide deposition and surface roughening resulting from the HIPIMS and p-DC treatments will promote adhesion to any subsequent thin film that is deposited immediately following the plasma treatment.

  7. PET/MRI: Where might it replace PET/CT?

    Science.gov (United States)

    Ehman, Eric C; Johnson, Geoffrey B; Villanueva-Meyer, Javier E; Cha, Soonmee; Leynes, Andrew Palmera; Larson, Peder Eric Zufall; Hope, Thomas A

    2017-11-01

    Simultaneous positron emission tomography and MRI (PET/MRI) is a technology that combines the anatomic and quantitative strengths of MR imaging with physiologic information obtained from PET. PET and computed tomography (PET/CT) performed in a single scanning session is an established technology already in widespread and accepted use worldwide. Given the higher cost and complexity of operating and interpreting the studies obtained on a PET/MRI system, there has been question as to which patients would benefit most from imaging with PET/MRI versus PET/CT. In this article, we compare PET/MRI with PET/CT, detail the applications for which PET/MRI has shown promise and discuss impediments to future adoption. It is our hope that future work will prove the benefit of PET/MRI to specific groups of patients, initially those in which PET/CT and MRI are already performed, leveraging simultaneity and allowing for greater degrees of multiparametric evaluation. 5 Technical Efficacy: Stage 5 J. Magn. Reson. Imaging 2017;46:1247-1262. © 2017 International Society for Magnetic Resonance in Medicine.

  8. Optimization of water distribution systems in high-rise buildings

    Energy Technology Data Exchange (ETDEWEB)

    Loh, Han Tong; Chew, T.C.

    1994-12-31

    The scarcity of land in Singapore has led to a rapid escalation of land prices in recent years. This has resulted in developers building taller and taller buildings in order to maximize their return on building projects. Due to the height involved, the water distribution system in such buildings is a multi-stage one. Hence the problem of deciding the number of stages and the location of each stage arises. In this paper, we will describe the design decisions to be taken in the preliminary design of a multi-stage water distribution system in a high-rise building and pose it as an optimization problem to minimize the overall cost of implementation. The variable costcomponents are the cost of pumps, the floor space cost and the operational cost of the water distribution system. We will describe a study on a 66-story building and highlight the major findings. Interesting results are observed when the cost components are taken one at a time. The strategy for finding the optimum or near optimum for other high-rise buildings will be discussed.

  9. Selecting Safe Pets (For Parents)

    Science.gov (United States)

    ... a dangerous situation. Before choosing any kind of animal for your family, learn as much as you can about your pet-to-be: Read pet guides explaining the various personalities, tendencies, and backgrounds of specific breeds in detail. ...

  10. Medical application of PET technology

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Sang Moo; Choi, C. W.; An, S. H.; Woo, K. S.; Chung, W. S.; Yang, S. D.; Jun, G. S. and others

    1999-04-01

    We performed following studies using PET technology: 1. Clinical usefulness of [{sup 18}F]FDG whole body PET in malignant disease 2. Clinical usefulness of quantitative evaluation of F-18-FDG 3. Pilot study of C-11 methionine PET in brain tumor 4. PET study in patients with Parkinson's disease 5. A study on the clinical myocardial PET image. PET gives various metabolic information for the living human body, and is very important, new diagnostic modality. The PET study will give us the information of cancer patients such as early detection of cancer, staging, recurrence detection and characterization of cancer. The quantitative analysis using PET could be applied to evaluate the pathophysiology of various diseases and develop new drugs and develop new radiopharmaceuticals.

  11. PET in neuro-oncology

    NARCIS (Netherlands)

    Roelcke, U; Leenders, K.L.

    This article reviews possible clinical applications of positron emission tomography (PET) in brain tumor patients. PET allows quantitative assessment of brain tumor pathophysiology and biochemistry. It therefore provides different information about tumors when compared to histological or

  12. 4-D PET-MR with Volumetric Navigators and Compressed Sensing

    DEFF Research Database (Denmark)

    Pedemonte, Stefano; Catana, Ciprian; Van Leemput, Koen

    2015-01-01

    Hybrid PET-MR scanners acquire multi-modal signals simultaneously, eliminating the requirement of software alignment between the MR and PET imaging data. However, the acquisition of high-resolution MR and PET images requires long scanning times, therefore movement of the subject during the acquis......Hybrid PET-MR scanners acquire multi-modal signals simultaneously, eliminating the requirement of software alignment between the MR and PET imaging data. However, the acquisition of high-resolution MR and PET images requires long scanning times, therefore movement of the subject during...... the acquisition deteriorates both the PET and the MR images. In this work we have developed an approach for tightly integrated PET-MR imaging, making use of volumetric MR navigators to inform, in real-time, both the MR acquisition and the PET reconstruction. The integrated imaging procedure that we describe...... exploits the simultaneity of MR and PET in hybrid PET-MR systems, producing inherently-aligned motion-free MR and PET images. We describe the system setup, the algorithm for motion-corrected reconstruction, an adaptive sinogram binning algorithm and software design decisions aimed at integrating tightly...

  13. Assessment of the high performance light water reactor concept

    Energy Technology Data Exchange (ETDEWEB)

    Starflinger, J. [Univ. of Stuttgart, IKE, (Germany); Schulenberg, T. [Karlsruhe Inst. of Tech., Karlsruhe (Germany); Bittermann, D. [AREVA NP GmbH, Erlangen (Germany); Andreani, M. [Paul Scherrer Inst., Villigen (Switzerland); Maraczy, C. [AEKI-KFKI, Budapest (Hungary)

    2011-07-01

    From 2006-2010, the High Performance Light Water Reactor (HPLWR) was investigated within a European Funded project called HPLWR Phase 2. Operated at 25MPa with a heat-up rate in the core from 280{sup o}C to 500{sup o}C, this reactor concept provides a technological challenge in the fields of design, neutronics, thermal-hydraulics and heat transfer, materials, and safety. The assessment of the concept with respect to the goals of the technology roadmap for Generation IV Nuclear Reactors of the Generation IV International Forum shows that the HPLWR has a potential to fulfil the goals of economics, safety and proliferation resistance and physical protection. In terms of sustainability, the HPLWR with a thermal neutron spectrum investigated within this project, does not differ from existing Light Water Reactors in terms of usage of fuel and waste production. (author)

  14. Polarization gating of high harmonic generation in the water window

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jie; Ren, Xiaoming; Yin, Yanchun; Cheng, Yan; Cunningham, Eric; Wu, Yi; Chang, Zenghu, E-mail: Zenghu.Chang@ucf.edu [Institute for the Frontier of Attosecond Science and Technology, CREOL and Department of Physics, University of Central Florida, Orlando, Florida 32816 (United States)

    2016-06-06

    We implement the polarization gating (PG) technique with a two-cycle, 1.7 μm driving field to generate an attosecond supercontinuum extending to the water window spectral region. The ellipticity dependence of the high harmonic yield over a photon energy range much broader than previous work is measured and compared with a semi-classical model. When PG is applied, the carrier-envelope phase (CEP) is swept to study its influence on the continuum generation. PG with one-cycle (5.7 fs) and two-cycle (11.3 fs) delay are tested, and both give continuous spectra spanning from 50 to 450 eV under certain CEP values, strongly indicating the generation of isolated attosecond pulses in the water window region.

  15. MR-based attenuation correction for cardiac FDG PET on a hybrid PET/MRI scanner: comparison with standard CT attenuation correction

    Energy Technology Data Exchange (ETDEWEB)

    Vontobel, Jan; Liga, Riccardo; Possner, Mathias; Clerc, Olivier F.; Mikulicic, Fran; Veit-Haibach, Patrick; Voert, Edwin E.G.W. ter; Fuchs, Tobias A.; Stehli, Julia; Pazhenkottil, Aju P.; Benz, Dominik C.; Graeni, Christoph; Gaemperli, Oliver; Herzog, Bernhard; Buechel, Ronny R.; Kaufmann, Philipp A. [University Hospital Zurich, Department of Nuclear Medicine, Zurich (Switzerland)

    2015-09-15

    The aim of this study was to evaluate the feasibility of attenuation correction (AC) for cardiac {sup 18}F-labelled fluorodeoxyglucose (FDG) positron emission tomography (PET) using MR-based attenuation maps. We included 23 patients with no known cardiac history undergoing whole-body FDG PET/CT imaging for oncological indications on a PET/CT scanner using time-of-flight (TOF) and subsequent whole-body PET/MR imaging on an investigational hybrid PET/MRI scanner. Data sets from PET/MRI (with and without TOF) were reconstructed using MR AC and semi-quantitative segmental (20-segment model) myocardial tracer uptake (per cent of maximum) and compared to PET/CT which was reconstructed using CT AC and served as standard of reference. Excellent correlations were found for regional uptake values between PET/CT and PET/MRI with TOF (n = 460 segments in 23 patients; r = 0.913; p < 0.0001) with narrow Bland-Altman limits of agreement (-8.5 to +12.6 %). Correlation coefficients were slightly lower between PET/CT and PET/MRI without TOF (n = 460 segments in 23 patients; r = 0.851; p < 0.0001) with broader Bland-Altman limits of agreement (-12.5 to +15.0 %). PET/MRI with and without TOF showed minimal underestimation of tracer uptake (-2.08 and -1.29 %, respectively), compared to PET/CT. Relative myocardial FDG uptake obtained from MR-based attenuation corrected FDG PET is highly comparable to standard CT-based attenuation corrected FDG PET, suggesting interchangeability of both AC techniques. (orig.)

  16. PET/MR: Yet another Tesla?

    Science.gov (United States)

    Schwaiger, Markus; Kunze, Karl; Rischpler, Christoph; Nekolla, Stephan G

    2017-06-01

    After the successful introduction of PET/CT as a multimodality imaging technique, PET/MR has subsequently emerged as an attractive instrumentation for applications in neurology, oncology, and cardiology. Simultaneous data acquisition combining structural, functional, and molecular imaging provides a unique platform to link various aspects of cardiac performance for the non-invasive characterization of cardiovascular disease phenotypes. Specifically, tissue characterization by MR techniques with and without contrast agents allows for functional parameters such as LGE, myocardial perfusion, and T1 maps as well as an estimate of extracellular volume. PET tracers excel by their high sensitivity and specificity, thus supplementing the functional tissue characterization by MRI. Although the clinical applications are yet to be validated , the first experience with PET/MR suggests future applications in the area of vascular imaging (unstable plaque) as well as in the characterization of inflammatory processes involving the heart. Ischemic heart disease can be comprehensively assessed by integrating regional function, perfusion, and viability. Future technical improvements leading to less costly PET/MR instrumentation are necessary to support routine clinical application of this promising technique in cardiology.

  17. EUV micropatterning for biocompatibility control of PET

    Science.gov (United States)

    Reisinger, B.; Fahrner, M.; Frischauf, I.; Yakunin, S.; Svorcik, V.; Fiedorowicz, H.; Bartnik, A.; Romanin, C.; Heitz, J.

    2010-08-01

    We have investigated the influence of oriented microstructures at modified polyethylene terephthalate (PET) on the adhesion and alignment of Chinese hamster ovary (CHO) cells. For surface modification, the PET foils were exposed to the radiation of a laser-plasma extreme ultraviolet (EUV) source based on a double-stream gas-puff target. The emission of the plasma was focused onto the samples by means of a gold-plated ellipsoidal collector. The spectrum of the focused radiation covered the wavelength range from 9 to 70 nm. The PET samples were irradiated with the EUV pulses at a repetition rate of 10 Hz in a high vacuum. For control experiments, PET samples were also irradiated in air with the light of a 193 nm ArF-excimer laser. Different kinds of surface microstructures were obtained depending on the EUV or laser fluence and pulse number, including oriented wall- and ripple-type structures with lateral structure periods of a few µm. The surface morphology of polymer samples after the irradiation was investigated using a scanning electron microscope (SEM). Changes in chemical surface structure of the irradiated samples were investigated using X-ray photoelectron spectroscopy (XPS). We demonstrated that the cells show good adhesion and align along oriented wall- and ripple-type microstructures on PET surfaces produced by the EUV irradiation.

  18. Evaluation of various hepatic lesions with PET

    Energy Technology Data Exchange (ETDEWEB)

    Han, Chul Ju

    2000-12-01

    When a liver lesion is found in a PET image, differential diagnosis and analysis of the lesion is very important. We tried to analyze hepatic lesions found in PET. 53 patients with focal liver lesions (13 patients with HCC, 8 patients with cholangiocarcinoma (CC), 20 patients with liver metastasis, 5 patients with hemangioma, 7 patients with liver abscess, including 1 patient with liver candidiasis) were examined. Definitely high FDG uptake pattern were observed in 54% (7/13) of HCC, 100% (8/8) of CC, 95% (19/20) of metastatic liver cancer and 100% (7/7) of liver abscess. Therefore, PET was partially useful in the diagnosis of HCC, but it was very useful in the diagnosis of CC or liver metastasis or liver abscess. The contrast between lesions and surrounding liver background was very conspicuous in PET images of CC or liver metastasis or liver abscess, which suggests that PET might be used for the follow up and assessment of treatment response of these diseases.

  19. Oxy-combustion of high water content fuels

    Science.gov (United States)

    Yi, Fei

    As the issues of global warming and the energy crisis arouse extensive concern, more and more research is focused on maximizing energy efficiency and capturing CO2 in power generation. To achieve this, in this research, we propose an unconventional concept of combustion - direct combustion of high water content fuels. Due to the high water content in the fuels, they may not burn under air-fired conditions. Therefore, oxy-combustion is applied. Three applications of this concept in power generation are proposed - direct steam generation for the turbine cycle, staged oxy-combustion with zero flue gas recycle, and oxy-combustion in a low speed diesel-type engine. The proposed processes could provide alternative approaches to directly utilize fuels which intrinsically have high water content. A large amount of energy to remove the water, when the fuels are utilized in a conventional approach, is saved. The properties and difficulty in dewatering high water content fuels (e.g. bioethanol, microalgae and fine coal) are summarized. These fuels include both renewable and fossil fuels. In addition, the technique can also allow for low-cost carbon capture due to oxy-combustion. When renewable fuel is utilized, the whole process can be carbon negative. To validate and evaluate this concept, the research focused on the investigation of the flame stability and characteristics for high water content fuels. My study has demonstrated the feasibility of burning fuels that have been heavily diluted with water in a swirl-stabilized burner. Ethanol and 1-propanol were first tested as the fuels and the flame stability maps were obtained. Flame stability, as characterized by the blow-off limit -- the lowest O2 concentration when a flame could exist under a given oxidizer flow rate, was determined as a function of total oxidizer flow rate, fuel concentration and nozzle type. Furthermore, both the gas temperature contour and the overall ethanol concentration in the droplets along the

  20. Performance of whole-body integrated 18F-FDG PET/MR in comparison to PET/CT for evaluation of malignant bone lesions.

    Science.gov (United States)

    Eiber, Matthias; Takei, Toshiki; Souvatzoglou, Michael; Mayerhoefer, Marius E; Fürst, Sebastian; Gaertner, Florian C; Loeffelbein, Denys J; Rummeny, Ernst J; Ziegler, Sibylle I; Schwaiger, Markus; Beer, Ambros J

    2014-02-01

    among sets A (85/90), B (84/90), and C (86/90). For bone lesions and regions of normal bone, a highly significant correlation existed between the mean SUVs for PET/MR and PET/CT (R = 0.950 and 0.917, respectively, each P bone lesions (12.4% ± 15.5%) and for regions of normal bone (30.1% ± 27.5%). Compared with PET/CT, fully integrated whole-body (18)F-FDG PET/MR is technically and clinically robust for evaluation of bone lesions despite differences in attenuation correction. PET/MR, including diagnostic T1-weighted TSE sequences, was superior to PET/CT for anatomic delineation and allocation of bone lesions. This finding might be of clinical relevance in selected cases--for example, primary bone tumors, early bone marrow infiltration, and tumors with low uptake on PET. Thus, a diagnostic T1-weighted TSE sequence is recommended as a routine protocol for oncologic PET/MR.

  1. A Real Time Coincidence System for High Count-Rate TOF or Non-TOF PET Cameras Using Hybrid Method Combining AND-Logic and Time-Mark Technology.

    Science.gov (United States)

    Wang, Chao; Li, Hongdi; Ramirez, Rocio A; Zhang, Yuxuan; Baghaei, Hossain; Liu, Shitao; An, Shaohui; Wong, Wai-Hoi

    2010-04-01

    A fully digital FPGA-based high count-rate coincidence system has been developed for TOF (Time of Flight) and non-TOF PET cameras. Using a hybrid of AND-logic and Time-mark technology produced both excellent timing resolution and high processing speed. In this hybrid architecture, every gamma event was synchronized by a 125 MHz system clock and generating a trigger associated with a time-mark given by an 8-bit high-resolution TDC (68.3 ps/bin). AND-logic was applied to the synchronized triggers for the real-time raw sorting of coincident events. An efficient FPGA based Time-mark fine-sort algorithm is used to select all the possible coincidence events within the preset coincidence time window. This FPGA-based coincidence system for a modular PET camera offers reprogrammable flexibility and expandability, so the coincidence system is easily employed, regardless of differences in the scale of the PET camera detector setup. A distributed processing method and pipeline technology were adopted in the design to obtain very high processing speed. In this design, both prompt and time-delayed accidental coincidences are simultaneously processed in real time. The real-time digital coincidence system supports coincidence in 2 to 12 detector module setups, capable of processing 72 million single events per second with no digital data loss and captures multiple-event coincidence for better imaging performance evaluation. The coincidence time window-size and time-offset of each coincidence event pair can be programmed independently in 68.3 ps increments (TDC LSB) during the data acquisition in different applications to optimize the signal-to-noise ratio. The complex coincidence system is integrated in one circuit board with 1.5 Gbps fiber optic interface. We demonstrated the system performance using the actual circuit and Monte Carlo simulations.

  2. Determination of carbonyl compounds (acetaldehyde and formaldehyde in polyethylene terephthalate containers designated for water conservation

    Directory of Open Access Journals (Sweden)

    Redžepović Azra S.

    2012-01-01

    Full Text Available Polyethylene terephthalate (PET has in the last several years become the main packaging material for many food products, particularly carbonated beverages and bottled water, as well as for products of chemical industry (packaging of various hygiene maintenance agents, pesticides, solvents, etc.. The strength and permeability properties of PET are very good for packaging of beverages, its resistance to chemicals is high and it has a high degree of transparency. Acetaldehyde and formaldehyde are formed during the thermoforming of PET containers. After cooling, acetaldehyde and formaldehyde remain trapped in the walls of a PET bottle and may migrate into the water after filling and storage. Since there are no migration tests in Serbia prescribed for the determination of acetaldehyde and formaldehyde, the purpose of the paper is to test the quantitative contents of carbonyl compounds (acetaldehyde and formaldehyde in PET containers of different volumes, made by various manufacturers of bottled mineral carbonated and noncarbonated water, and exposed to different temperatures. In this study, the migration of acetaldehyde and formaldehyde from PET bottles into mineral carbonated and noncarbonated water was determined by high performance liquid chromatography. Taking into consideration that formaldehyde and acetaldehyde have no UV active or fluorescent group, the chromatography shall be preceded by derivatization in a closed system (due to a low boiling point of acetaldehyde and formaldehyde, which shall transform carbonyl compounds into UV active compounds.

  3. Plant Control of the High Performance Light Water Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Schlagenhaufer, Marc; Starflinger, J.; Schulenberg, T. [Institute for Nuclear and Energy Technologies, Forschungszentrum Karlsruhe GmbH, Hermann-von-Helmholtz-Platz 1, Eggenstein-Leopoldshafen, Baden-Wuertemberg 76344 (Germany)

    2009-06-15

    The latest design concept of the High Performance Light Water Reactor (HPLWR) includes a thermal core in which supercritical water at 25 MPa inlet pressure is heated up from 280 deg. C reactor inlet temperature to 500 deg. C core exit temperature in three steps with intermediate coolant mixing to minimize peak cladding temperatures of the fuel rods. A direct supercritical steam cycle of the HPLWR has been designed with high, intermediate and low pressure turbines with a single reheat to 441 deg. C at 4.04 MPa pressure. Three low pressure pre-heaters and four high pressure pre-heaters are foreseen to achieve the envisaged reactor inlet temperature of 280 deg. C at full load. A feedwater tank of 603 m{sup 3} at 0.55 MPa pressure serves as an accumulator for normal and accidental conditions. The steam cycle has been modelled with APROS, developed by VTT Finland, to provide thermodynamic data and cycle efficiency values under full load and part load operation conditions as well as the transient response to load changes. A plant control system has been designed in which the reactor inlet pressure is controlled by the turbine valve, the reactor power is controlled by the feedwater pumps while the life steam temperature is controlled by control rods, and the reheat temperature is controlled by the reheater valve. Neglecting the reactivity control, the core power can also be treated as input parameter such that the life steam temperature is directly controlled by the feedwater mass flow. The plant control can handle all loading and de-loading cycles including complete shut down. A constant pressure at reactor inlet is foreseen for all load cases. Peak temperatures of the fuel pins are checked with a simplified core model. Two shut down procedures starting at 50% load are presented. A reactor scram with turbine states the safe shut down of the whole plant. To avoid hard material temperature changes, a controlled shut down procedure is designed. The rotational speed of the

  4. PET imaging in multiple sclerosis

    NARCIS (Netherlands)

    Faria, Daniele de Paula; Copray, Sjef; Buchpiguel, Carlos; Dierckx, Rudi; de Vries, Erik

    Positron emission tomography (PET) is a non-invasive technique for quantitative imaging of biochemical and physiological processes in animals and humans. PET uses probes labeled with a radioactive isotope, called PET tracers, which can bind to or be converted by a specific biological target and thus

  5. Metabolic imaging using PET

    Energy Technology Data Exchange (ETDEWEB)

    Kudo, Takashi [University of Fukui, Biomedical Imaging Research Center, Eiheiji-cho, Fukui (Japan)

    2007-06-15

    There is growing evidence that myocardial metabolism plays a key role not only in ischaemic heart disease but also in a variety of diseases which involve myocardium globally, such as heart failure and diabetes mellitus. Understanding myocardial metabolism in such diseases helps to elucidate the pathophysiology and assists in making therapeutic decisions. As well as providing information on regional changes, PET can deliver quantitative information about both regional and global changes in metabolism. This capability of quantitative measurement is one of the major advantages of PET along with physiological positron tracers, especially relevant in evaluating diseases which involve the whole myocardium. This review discusses major PET tracers for metabolic imaging and their clinical applications and contributions to research regarding ischaemic heart disease and other diseases such as heart failure and diabetic heart disease. Future applications of positron metabolic tracers for the detection of vulnerable plaque are also highlighted briefly. (orig.)

  6. The analysis of energy efficiency in water electrolysis under high temperature and high pressure