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Sample records for animal pet scanner

  1. Performance evaluation of the Philips MOSAIC small animal PET scanner

    International Nuclear Information System (INIS)

    Huisman, Marc C.; Reder, Sybille; Ziegler, Sibylle I.; Schwaiger, Markus; Weber, Axel W.

    2007-01-01

    In this study an evaluation of the performance of the Philips MOSAIC small animal PET scanner is presented, with special emphasis on the ability of the system to provide quantitatively accurate PET images. The performance evaluation was structured according to NEMA-like procedures. The transaxial spatial resolution of the system (radial component) ranged between 2.7 mm FWHM at the centre and 3.2 mm FWHM at a radial offset of 45 mm from the centre. The axial spatial resolution of the system ranged between 3.4 mm FWHM at the centre and 5.8 mm FWHM at a radial offset of 45 mm from the centre. The scatter fraction was determined for a mouse- as well as for a rat-sized phantom, and the values obtained were 9.6% and 16.8%, respectively. For the mouse phantom, the maximum count rate measured was 560 kcps at 93 MBq; the maximum NEC rate equalled 308 kcps at 1.7 MBq/ml. For the rat phantom, these values were 400 kcps at 100 MBq and 129 kcps at 0.24 MBq/ml, respectively. The sensitivity of the system was derived to be 0.65%. An energy window between 410 and 665 keV was used in all experiments. The MOSAIC system exhibits moderate spatial resolution and sensitivity values, but good NEC performance. In combination with its relatively large field of view, the system allows for high-throughput whole-body imaging of mice and rats. The accurate measurement of relative changes in radiotracer distributions is feasible. (orig.)

  2. Impacts of Intelligent Automated Quality Control on a Small Animal APD-Based Digital PET Scanner

    Science.gov (United States)

    Charest, Jonathan; Beaudoin, Jean-François; Bergeron, Mélanie; Cadorette, Jules; Arpin, Louis; Lecomte, Roger; Brunet, Charles-Antoine; Fontaine, Réjean

    2016-10-01

    Stable system performance is mandatory to warrant the accuracy and reliability of biological results relying on small animal positron emission tomography (PET) imaging studies. This simple requirement sets the ground for imposing routine quality control (QC) procedures to keep PET scanners at a reliable optimal performance level. However, such procedures can become burdensome to implement for scanner operators, especially taking into account the increasing number of data acquisition channels in newer generation PET scanners. In systems using pixel detectors to achieve enhanced spatial resolution and contrast-to-noise ratio (CNR), the QC workload rapidly increases to unmanageable levels due to the number of independent channels involved. An artificial intelligence based QC system, referred to as Scanner Intelligent Diagnosis for Optimal Performance (SIDOP), was proposed to help reducing the QC workload by performing automatic channel fault detection and diagnosis. SIDOP consists of four high-level modules that employ machine learning methods to perform their tasks: Parameter Extraction, Channel Fault Detection, Fault Prioritization, and Fault Diagnosis. Ultimately, SIDOP submits a prioritized faulty channel list to the operator and proposes actions to correct them. To validate that SIDOP can perform QC procedures adequately, it was deployed on a LabPET™ scanner and multiple performance metrics were extracted. After multiple corrections on sub-optimal scanner settings, a 8.5% (with a 95% confidence interval (CI) of [7.6, 9.3]) improvement in the CNR, a 17.0% (CI: [15.3, 18.7]) decrease of the uniformity percentage standard deviation, and a 6.8% gain in global sensitivity were observed. These results confirm that SIDOP can indeed be of assistance in performing QC procedures and restore performance to optimal figures.

  3. PET performance evaluation of MADPET4: a small animal PET insert for a 7 T MRI scanner

    Science.gov (United States)

    Omidvari, Negar; Cabello, Jorge; Topping, Geoffrey; Schneider, Florian R.; Paul, Stephan; Schwaiger, Markus; Ziegler, Sibylle I.

    2017-11-01

    MADPET4 is the first small animal PET insert with two layers of individually read out crystals in combination with silicon photomultiplier technology. It has a novel detector arrangement, in which all crystals face the center of field of view transaxially. In this work, the PET performance of MADPET4 was evaluated and compared to other preclinical PET scanners using the NEMA NU 4 measurements, followed by imaging a mouse-size hot-rod resolution phantom and two in vivo simultaneous PET/MRI scans in a 7 T MRI scanner. The insert had a peak sensitivity of 0.49%, using an energy threshold of 350 keV. A uniform transaxial resolution was obtained up to 15 mm radial offset from the axial center, using filtered back-projection with single-slice rebinning. The measured average radial and tangential resolutions (FWHM) were 1.38 mm and 1.39 mm, respectively. The 1.2 mm rods were separable in the hot-rod phantom using an iterative image reconstruction algorithm. The scatter fraction was 7.3% and peak noise equivalent count rate was 15.5 kcps at 65.1 MBq of activity. The FDG uptake in a mouse heart and brain were visible in the two in vivo simultaneous PET/MRI scans without applying image corrections. In conclusion, the insert demonstrated a good overall performance and can be used for small animal multi-modal research applications.

  4. 137Cs transmission imaging and segmented attenuation corrections in a small animal PET scanner.

    Science.gov (United States)

    Nai, Ying-Hwey; Ose, Takayuki; Shidahara, Miho; Watabe, Hiroshi

    2017-09-01

    Attenuation correction (AC) is required for accurate quantitative evaluation of small animal PET data. Our objective was to compare three AC methods in the small animal Clairvivo-PET scanner. The three AC methods involve applying attenuation coefficient maps generated by simulating a cylindrical map (SAC), segmenting the emission data (ESAC), and segmenting the transmission data (TSAC), imaged using a 137 Cs single-photon source. Investigation was carried out using a 65 mm uniform cylinder and an NEMA NU4 2008 mouse phantom, filled with water or tungsten liquid, to mimic bone. Evaluation was carried out using the difference of the segmented map volume from the known cylindrical phantom volume, the recovery of the radioactivity concentration, and the line profiles. The optimal transmission scan time for achieving accurate AC using TSAC was determined using 5, 10, 15, 20, and 25 min transmission scan time. The effects of scatter correction and reconstruction algorithms on ESAC were investigated. SAC showed the best performance but was unable to correct for different tissues and the scanner bed, and faced difficulty with correct positioning of the attenuation coefficient map. ESAC was affected by scatter correction and reconstruction algorithm, and may result in poor boundary delineation, and hence was unreliable. TSAC showed reasonable performance but required further optimization of the default segmentation setting. A minimum transmission scan time of 20 min is recommended for Clairvivo-PET using 137 Cs source to ensure that sufficient transmission counts are obtained to generate accurate attenuation coefficient map.

  5. Simulated performance of a small-animal PET scanner based on monolithic scintillation detectors

    International Nuclear Information System (INIS)

    Laan, D.J. van der; Maas, M.C.; Jong, H.W.A.M. de; Schaart, D.R.; Bruyndonckx, P.; Lemaitre, C.; Eijk, C.W.E. van

    2007-01-01

    The performance of a small-animal positron emission tomography (PET) scanner based on monolithic scintillation detectors read-out by avalanche photo-diode arrays has been investigated by simulation. By minimizing dead space, both within and between the modules, these detectors offer increased detection efficiency compared to pixellated detectors. The spatial resolution of the scanner was investigated in 2-D by simulating a point source at various radial distances from the center. To model the detector response, measured detector line-spread functions were used. An optimum value of approximately 1 mm FWHM was found at 10 mm radial distance from the scanner central axis. Point-source sensitivity profiles in the radial and axial directions were simulated at 1 MBq activity using the Monte-Carlo code GATE. They indicated that monolithic designs increase the sensitivity roughly by a factor of two compared to pixellated designs. NECR curves simulated for these scanner designs show no significant degradation of the performance for activities up to 40 MBq

  6. An investigation of a coincidence detection system for an all-digital small animal PET scanner

    International Nuclear Information System (INIS)

    Liu Wei; Chen Yuanbao; Long Anwen; Chen Xin; Wu Zhongyi; Zhang Yongxue; Xie Qingguo

    2013-01-01

    Objective: To investigate and design a coincidence detection system for an all-digital small animal PET scanner and evaluate its preliminary performance properties. Methods: This coincidence module adopted a coincidence identification mode based on singles data in list-mode.Using digital signal processing technology, energy calibration, crystal identification, timing alignment and coincidence events extraction were performed on singles data in list-mode. The obtained data could be used for image reconstruction. Results: The 13 × 13 crystal array was well recognized by the position histogram of one lutetium yttrium orthosilicate (LYSO) crystal block. In the coincidence timing histogram of the micro-Derenzo phantom, 1.36 ns full width at half maximum was obtained. The rods with a diameter of 1.2 mm were clearly displayed in the reconstructed image of the micro-Derenzo phantom. Conclusion: The coincidence module can provide satisfactory performance to meet the design needs of an all-digital small animal PET scanner. (authors)

  7. Attenuation correction for freely moving small animal brain PET studies based on a virtual scanner geometry

    International Nuclear Information System (INIS)

    Angelis, G I; Kyme, A Z; Ryder, W J; Fulton, R R; Meikle, S R

    2014-01-01

    Attenuation correction in positron emission tomography brain imaging of freely moving animals is a very challenging problem since the torso of the animal is often within the field of view and introduces a non negligible attenuating factor that can degrade the quantitative accuracy of the reconstructed images. In the context of unrestrained small animal imaging, estimation of the attenuation correction factors without the need for a transmission scan is highly desirable. An attractive approach that avoids the need for a transmission scan involves the generation of the hull of the animal’s head based on the reconstructed motion corrected emission images. However, this approach ignores the attenuation introduced by the animal’s torso. In this work, we propose a virtual scanner geometry which moves in synchrony with the animal’s head and discriminates between those events that traversed only the animal’s head (and therefore can be accurately compensated for attenuation) and those that might have also traversed the animal’s torso. For each recorded pose of the animal’s head a new virtual scanner geometry is defined and therefore a new system matrix must be calculated leading to a time-varying system matrix. This new approach was evaluated on phantom data acquired on the microPET Focus 220 scanner using a custom-made phantom and step-wise motion. Results showed that when the animal’s torso is within the FOV and not appropriately accounted for during attenuation correction it can lead to bias of up to 10% . Attenuation correction was more accurate when the virtual scanner was employed leading to improved quantitative estimates (bias < 2%), without the need to account for the attenuation introduced by the extraneous compartment. Although the proposed method requires increased computational resources, it can provide a reliable approach towards quantitatively accurate attenuation correction for freely moving animal studies. (paper)

  8. Evaluation of New Inorganic Scintillators for Application in a Prototype Small Animal PET Scanner

    CERN Document Server

    Kuntner, C

    2003-01-01

    In the study of new pharmaceuticals as well as brain and genetic research, Positron Emission Tomography (PET) is a useful method. It has also recently entered the clinical domain in cardiology and particularly in oncology. Small animals such as mice, are often used to validate sophisticated models of human disease. High spatial resolution PET instrumentation is therefore necessary due to the reduced dimensions of the organs. Inorganic scintillators are employed in most of the diagnostic imaging devices. The ultimate performance of the PET scanner is tightly bound to the scintillation properties of the crystals. In the last years there has been an effort to develop new scintillating materials characterized by high light output, high detection efficiency and fast decay time. The most studied systems are mainly Ce3+-doped crystals such as LSO:Ce, YAP:Ce, LuAP:Ce, and recently also mixed Lux(RE3+)1-xAlO3:Ce crystals. These crystals are very attractive for medical application because of their high density (with th...

  9. Accurate modeling of a DOI capable small animal PET scanner using GATE

    International Nuclear Information System (INIS)

    Zagni, F.; D'Ambrosio, D.; Spinelli, AE.; Cicoria, G.; Fanti, S.; Marengo, M.

    2013-01-01

    data confirms that the developed simulation setup is a useful tool for a wide range of research applications. - Highlights: ► We developed an MC model of the Argus (Sedecal) small-animal PET scanner using GATE. ► Validation was performed through comparison between simulated and experimental data. ► Spatial resolution, sensitivity and scatter fraction showed agreement within 7%. ► NEC was in excellent agreement at activities up to 50 MBq in the field of view. ► Image quality was also compared through the NEMA NU-4 phantom

  10. Performance Evaluation of a PEM Scanner Using the NEMA NU 4—2008 Small Animal PET Standards

    Science.gov (United States)

    Luo, Weidong; Anashkin, Edward; Matthews, Christopher G.

    2010-02-01

    The recently published NEMA NU 4-2008 Standards has been specially designed for evaluating the performance of small animal PET scanners used in preclinical applications. In this paper, we report on the NU 4 performance of a clinical positron emission mammography (PEM) system. Since there are no PEM specific performance test protocols available, and the NU 2 protocol (intended for whole-body PET scanners) cannot be applied without modification due to the compact design of the PEM scanner, we decided to evaluate the NU 4 Standards as an alternative. We obtained the following results: Trans-axial spatial resolution 1.8 mm FWHM for high resolution reconstruction mode and 2.4 mm FWHM for standard resolution reconstruction mode with no significant variation within the field of view. The total system sensitivity was 0.16 cps/Bq. In image quality testing, the uniformity was found to be 3.9% STD at the standard resolution mode and 5.6% at the high resolution mode when measured with a 34 mm paddle separation. The NEMA NU 4-2008 Standards were found to be a practicable tool to evaluate the performance of the PEM scanner after some modifications to address the specifics of its detector configuration. Furthermore, the PEM scanner's in-plane spatial resolution was comparable to other small animal PET scanners with good image quality.

  11. Evaluation of transmission methodology and attenuation correction for the microPET Focus 220 animal scanner

    International Nuclear Information System (INIS)

    Lehnert, Wencke; Meikle, Steven R; Siegel, Stefan; Newport, Danny; Banati, Richard B; Rosenfeld, Anatoly B

    2006-01-01

    An accurate, low noise estimate of photon attenuation in the subject is required for quantitative microPET studies of molecular tracer distributions in vivo. In this work, several transmission-based measurement techniques were compared, including coincidence mode with and without rod windowing, singles mode with two different energy sources ( 68 Ge and 57 Co), and postinjection transmission scanning. In addition, the effectiveness of transmission segmentation and the propagation of transmission bias and noise into the emission images were examined. The 57 Co singles measurements provided the most accurate attenuation coefficients and superior signal-to-noise ratio, while 68 Ge singles measurements were degraded due to scattering from the object. Scatter correction of 68 Ge transmission data improved the accuracy for a 10 cm phantom but over-corrected for a mouse phantom. 57 Co scanning also resulted in low bias and noise in postinjection transmission scans for emission activities up to 20 MBq. Segmentation worked most reliably for transmission data acquired with 57 Co but the minor improvement in accuracy of attenuation coefficients and signal-to-noise may not justify its use, particularly for small subjects. We conclude that 57 Co singles transmission scanning is the most suitable method for measured attenuation correction on the microPET Focus 220 animal scanner

  12. Automatic Channel Fault Detection on a Small Animal APD-Based Digital PET Scanner

    Science.gov (United States)

    Charest, Jonathan; Beaudoin, Jean-François; Cadorette, Jules; Lecomte, Roger; Brunet, Charles-Antoine; Fontaine, Réjean

    2014-10-01

    Avalanche photodiode (APD) based positron emission tomography (PET) scanners show enhanced imaging capabilities in terms of spatial resolution and contrast due to the one to one coupling and size of individual crystal-APD detectors. However, to ensure the maximal performance, these PET scanners require proper calibration by qualified scanner operators, which can become a cumbersome task because of the huge number of channels they are made of. An intelligent system (IS) intends to alleviate this workload by enabling a diagnosis of the observational errors of the scanner. The IS can be broken down into four hierarchical blocks: parameter extraction, channel fault detection, prioritization and diagnosis. One of the main activities of the IS consists in analyzing available channel data such as: normalization coincidence counts and single count rates, crystal identification classification data, energy histograms, APD bias and noise thresholds to establish the channel health status that will be used to detect channel faults. This paper focuses on the first two blocks of the IS: parameter extraction and channel fault detection. The purpose of the parameter extraction block is to process available data on individual channels into parameters that are subsequently used by the fault detection block to generate the channel health status. To ensure extensibility, the channel fault detection block is divided into indicators representing different aspects of PET scanner performance: sensitivity, timing, crystal identification and energy. Some experiments on a 8 cm axial length LabPET scanner located at the Sherbrooke Molecular Imaging Center demonstrated an erroneous channel fault detection rate of 10% (with a 95% confidence interval (CI) of [9, 11]) which is considered tolerable. Globally, the IS achieves a channel fault detection efficiency of 96% (CI: [95, 97]), which proves that many faults can be detected automatically. Increased fault detection efficiency would be

  13. Coincidence measurements on detectors for microPET II: A 1 mm3 resolution PET scanner for small animal imaging

    CERN Document Server

    Chatziioannou, A; Shao, Y; Doshi, N K; Silverman, B; Meadors, K; Cherry, SR

    2000-01-01

    We are currently developing a small animal PET scanner with a design goal of 1 mm3 image resolution. We have built three pairs of detectors and tested performance in terms of crystal identification, spatial, energy and timing resolution. The detectors consisted of 12 multiplied by 12 arrays of 1 multiplied by 1 multiplied by 10mm LSO crystals (1.15 mm pitch) coupled to Hamamatsu H7546 64 channel PMTs via 5cm long coherent glass fiber bundles. Optical fiber connection is necessary to allow high packing fraction in a ring geometry scanner. Fiber bundles with and without extramural absorber (EMA) were tested. The results demonstrated an intrinsic spatial resolution of 1.12 mm (direct coupled LSO array), 1.23 mm (bundle without EMA) and 1.27 mm (bundle with EMA) using a similar to 500 micron diameter Na-22 source. Using a 330 micron line source filled with F-18, intrinsic resolution for the EMA bundle improved to 1.05 mm. The respective timing and energy resolution values were 1.96 ns, 21% (direct coupled), 2.20 ...

  14. Performance evaluation of the small-animal PET scanner ClairvivoPET using NEMA NU 4-2008 Standards

    Science.gov (United States)

    Sato, K.; Shidahara, M.; Watabe, H.; Watanuki, S.; Ishikawa, Y.; Arakawa, Y.; Nai, YH; Furumoto, S.; Tashiro, M.; Shoji, T.; Yanai, K.; Gonda, K.

    2016-01-01

    The aim of this study was to evaluate the performance of ClairvivoPET using NEMA NU4 standards. The ClairvivoPET incorporates a LYSO dual depth-of-interaction detector system with 151 mm axial field of view (FOV). Spatial resolution, sensitivity, counting rate capabilities, and image quality were evaluated using NEMA NU4-2008 standards. Normal mouse imaging was also performed for 10min after intravenous injection of 18F(-)-NaF. Data were compared with 19 other preclinical PET scanners. Spatial resolution measured using full width at half maximum on FBP-ramp reconstructed images was 2.16 mm at radial offset 5 mm of the axial centre FOV. The maximum absolute sensitivity for a point source at the FOV centre was 8.72%. Peak noise equivalent counting rate (NECR) was 415kcps at 14.6MBq ml-1. The uniformity with the image-quality phantom was 4.62%. Spillover ratios in the images of air and water filled chambers were 0.19 and 0.06, respectively. Our results were comparable with the 19 other preclinical PET scanners based on NEMA NU4 standards, with excellent sensitivity because of the large FOV. The ClairvivoPET with iterative reconstruction algorithm also provided sufficient visualization of the mouse spine. The high sensitivity and resolution of the ClairvivoPET scanner provided high quality images for preclinical studies.

  15. 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)

  16. Image quality assesment using NEMA NU 4/2008 standards in small animal PET scanner

    International Nuclear Information System (INIS)

    Gontijo, Rodrigo M.G.; Ferreira, Andréa V.; Silva, Juliana B.; Mamede, Marcelo

    2017-01-01

    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 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)

  17. Design and construction of a small animal PET/CT scanner combining scintillation Phoswich modules and hybrid pixels detectors

    International Nuclear Information System (INIS)

    Nicol, St.

    2010-07-01

    The pathway that has been followed by the imXgam team at CPPM was to combine on a single rotating device the detector modules of the small animal PET scanner ClearPET with a photon counting X-ray detector in order to perform simultaneous acquisition of images from the anatomy (X-ray CT) and from the metabolic function (PET) of the common field-of-view. A preliminary study of the hybrid imaging system ClearPET/XPAD3 carried out using Gate led us to form a new PET detection assembly based on 21 Phoswich modules, to fix the design of the PET/CT device, as well as to study and solve the difficulties arising from simultaneous hybrid imaging. Last but not least, the simulation tool also allowed us for thinking how well such a system could judiciously use the spatial and temporal correlations between anatomic and functional information. From an instrumentation point of view, we succeeded to set up the ClearPET/XPAD3 prototype. Once both imaging systems were operational individually, we demonstrated on one side that the ClearPET prototype was perfectly capable of performing correctly in simultaneous acquisition conditions, providing that the detector modules were appropriately shielded. On the other side, the new generation of the hybrid pixel camera using the XPAD3-S chip proved to be quite promising given the good quality of the first reconstructed images. Finally, the proof of concept of simultaneous PET/CT data acquisition was made using a sealed positron source and an X-ray tube. (author)

  18. Scanner calibration of a small animal PET camera based on continuous LSO crystals and flat panel PSPMTs

    International Nuclear Information System (INIS)

    Benlloch, J.M.; Carrilero, V.; Gonzalez, A.J.; Catret, J.; Lerche, Ch.W.; Abellan, D.; Garcia de Quiros, F.; Gimenez, M.; Modia, J.; Sanchez, F.; Pavon, N.; Ros, A.; Martinez, J.; Sebastia, A.

    2007-01-01

    We have constructed a small animal PET with four identical detector modules, each consisting of a continuous LYSO crystal attached to a Position Sensitive Photomultiplier Tube (PSPMT). The dimensions of the continuous crystal are 50x50 mm 2 and 10 mm thickness. The modules are separated 11 cm between each other in the scanner. In this paper we discuss the method used for the calibration of the camera for this special system with continuous detectors. We also present the preliminary values for the main performance parameters such as spatial and energy resolution, and sensitivity of the system

  19. Compensation strategies for PET scanners with unconventional scanner geometry

    CERN Document Server

    Gundlich, B; Oehler, M

    2006-01-01

    The small animal PET scanner ClearPET®Neuro, developed at the Forschungszentrum Julich GmbH in cooperation with the Crystal Clear Collaboration (CERN), represents scanners with an unconventional geometry: due to axial and transaxial detector gaps ClearPet®Neuro delivers inhomogeneous sinograms with missing data. When filtered backprojection (FBP) or Fourier rebinning (FORE) are applied, strong geometrical artifacts appear in the images. In this contribution we present a method that takes the geometrical sensitivity into account and converts the measured sinograms into homogeneous and complete data. By this means artifactfree images are achieved using FBP or FORE. Besides an advantageous measurement setup that reduces inhomogeneities and data gaps in the sinograms, a modification of the measured sinograms is necessary. This modification includes two steps: a geometrical normalization and corrections for missing data. To normalize the measured sinograms, computed sinograms are used that describe the geometric...

  20. Synthesis and quality control of fluorodeoxyglucose and performance assessment of Siemens MicroFocus 220 small animal PET scanner

    Science.gov (United States)

    Phaterpekar, Siddhesh Nitin

    The scope of this article is to cover the synthesis and quality control procedures involved in production of Fludeoxyglucose (18F--FDG). The article also describes the cyclotron production of 18F radioisotope and gives a brief overview on operations and working of a fixed energy medical cyclotron. The quality control procedures for FDG involve radiochemical and radionuclidic purity tests, pH tests, chemical purity tests, sterility tests, endotoxin tests. Each of these procedures were carried out for multiple batches of FDG with a passing rate of 95% among 20 batches. The article also covers the quality assurance steps for the Siemens MicroPET Focus 220 Scanner using a Jaszczak phantom. We have carried out spatial resolution tests on the scanner, with an average transaxial resolution of 1.775mm with 2-3mm offset. Tests involved detector efficiency, blank scan sinograms and transmission sinograms. A series of radioactivity distribution tests are also carried out on a uniform phantom, denoting the variations in radioactivity and uniformity by using cylindrical ROIs in the transverse region of the final image. The purpose of these quality control tests is to make sure the manufactured FDG is biocompatible with the human body. Quality assurance tests are carried on PET scanners for efficient performance, and to make sure the quality of images acquired is according to the radioactivity distribution in the subject of interest.

  1. Development of a clear sub-millimeter small animal PET scanner by reducing the influence of the non-collinearity effect

    Science.gov (United States)

    Bolwin, K.; Vernekohl, D.; Lühder, J.; Czekalla, B.; Wessels, J. P.; Schäfers, K. P.

    2017-03-01

    Small animal PET plays a major role in studying molecular processes in vivo. However, the spatial resolution of small animal PET is limited by physical effects like positron range, photon non-collinearity, and object scattering. The aim of this project was to minimize the influence of the non-collinearity effect by reducing the distance between the coincidence detectors leading to an improved spatial resolution. A multi-wire proportional chamber-based high-resolution PET scanner (quadHIDAC) was used, offering a spatial resolution of nearly 1 mm FWHM. By removing two opposite detector banks of the 4-detector-setup, the inner distance between the two remaining detector plates could be reduced from 180 mm to 40 mm. List mode acquisitions of a small point source (22Na) experiment were performed, images were reconstructed (0.25 mm voxel size) using a one-pass list-mode EM algorithm and the FWHM in the radial, tangential, and axial directions was calculated. In addition, a Jaszczak phantom (hole sizes of 0.7 up to 1.2 mm) was acquired with both scanners. The prototype high-resolution PET scanner showed improved spatial resolution in radial (0.9 mm FWHM), tangential (0.9 mm FWHM), and axial (0.8 mm FWHM) direction compared to the quadHIDAC scanner (1.x mm, 1.x mm, 1.x mm), respectively offering clear sub-millimeter imaging. Blurring effects due to photon non-collinearity could be reduced by minimizing the detector distance.

  2. Instruments for radiation measurement in life sciences (5), ''Development of imaging technology in life sciences'' III. Development of small animal PET scanners

    International Nuclear Information System (INIS)

    Yamaya, Taiga; Murayama, Hideo

    2006-01-01

    This paper summarizes the requisites for small animal PET scanners, present state of their market and of their development in National Institute of Radiological Sciences (NIRS). Relative to the apparatus clinically used, the requisites involve the high spatial resolution of 0.8-1.5 mm and high sensitivity of the equipment itself due to low dose of the tracer to be given to animals. At present, more than 20 institutions like universities, research facilities and companies are developing the PET equipment for small animals and about 10 machines are in the market. However, their resolution and sensitivity are not fully satisfactory and for their improvement, investigators are paying attention to the gamma ray measurement by depth-of-interaction (DOI) method. NIRS has been also developing the machine jPET-D4 and has proposed to manufacture jPET-RD having 4-layer DOI detectors with the absolute central sensitivity as high as 14.7%. jPET-RD is to have the spatial resolution as high as <1mm (central view) and -1.4 mm (periphery). (T.I.)

  3. Simultaneous scanning of two mice in a small-animal PET scanner: a simulation-based assessment of the signal degradation.

    Science.gov (United States)

    Reilhac, Anthonin; Boisson, Frédéric; Wimberley, Catriona; Parmar, Arvind; Zahra, David; Hamze, Hasar; Davis, Emma; Arthur, Andrew; Bouillot, Caroline; Charil, Arnaud; Grégoire, Marie-Claude

    2016-02-07

    In PET imaging, research groups have recently proposed different experimental set ups allowing multiple animals to be simultaneously imaged in a scanner in order to reduce the costs and increase the throughput. In those studies, the technical feasibility was demonstrated and the signal degradation caused by additional mice in the FOV characterized, however, the impact of the signal degradation on the outcome of a PET study has not yet been studied. Here we thoroughly investigated, using Monte Carlo simulated [18F]FDG and [11C]Raclopride PET studies, different experimental designs for whole-body and brain acquisitions of two mice and assessed the actual impact on the detection of biological variations as compared to a single-mouse setting. First, we extended the validation of the PET-SORTEO Monte Carlo simulation platform for the simultaneous simulation of two animals. Then, we designed [18F]FDG and [11C]Raclopride input mouse models for the simulation of realistic whole-body and brain PET studies. Simulated studies allowed us to accurately estimate the differences in detection between single- and dual-mode acquisition settings that are purely the result of having two animals in the FOV. Validation results showed that PET-SORTEO accurately reproduced the spatial resolution and noise degradations that were observed with actual dual phantom experiments. The simulated [18F]FDG whole-body study showed that the resolution loss due to the off-center positioning of the mice was the biggest contributing factor in signal degradation at the pixel level and a minimal inter-animal distance as well as the use of reconstruction methods with resolution modeling should be preferred. Dual mode acquisition did not have a major impact on ROI-based analysis except in situations where uptake values in organs from the same subject were compared. The simulated [11C]Raclopride study however showed that dual-mice imaging strongly reduced the sensitivity to variations when mice were

  4. Geometric calibration between PET scanner and structured light scanner

    DEFF Research Database (Denmark)

    Kjer, Hans Martin; Olesen, Oline Vinter; Paulsen, Rasmus Reinhold

    2011-01-01

    Head movements degrade the image quality of high resolution Positron Emission Tomography (PET) brain studies through blurring and artifacts. Manny image reconstruction methods allows for motion correction if the head position is tracked continuously during the study. Our method for motion tracking...... is a structured light scanner placed just above the patient tunnel on the High Resolution Research Tomograph (HRRT, Siemens). It continuously registers point clouds of a part of the patient's face. The relative motion is estimated as the rigid transformation between frames. A geometric calibration between...... the HRRT scanner and the tracking system is needed in order to reposition the PET listmode data or image frames in the HRRT scanner coordinate system. This paper presents a method where obtained transmission scan data is segmented in order to create a point cloud of the patient's head. The point clouds...

  5. A PET scanner developed by CERN

    CERN Multimedia

    Laurent Guiraud

    1998-01-01

    This image shows a Position Emission Tomography (PET) scanner at the Hopital Cantonal Universitaire de Genève. Development of the multiwire proportional chamber at CERN in the mid-1970s was soon seen as a potential device for medical imaging. It is much more sensitive than previous devices and greatly reduced the dose of radiation received by the patient.

  6. Development of scintillation materials for PET scanners

    CERN Document Server

    Korzhik, Mikhail; Annenkov, Alexander N; Borissevitch, Andrei; Dossovitski, Alexei; Missevitch, Oleg; Lecoq, Paul

    2007-01-01

    The growing demand on PET methodology for a variety of applications ranging from clinical use to fundamental studies triggers research and development of PET scanners providing better spatial resolution and sensitivity. These efforts are primarily focused on the development of advanced PET detector solutions and on the developments of new scintillation materials as well. However Lu containing scintillation materials introduced in the last century such as LSO, LYSO, LuAP, LuYAP crystals still remain the best PET species in spite of the recent developments of bright, fast but relatively low density lanthanum bromide scintillators. At the same time Lu based materials have several drawbacks which are high temperature of crystallization and relatively high cost compared to alkali-halide scintillation materials. Here we describe recent results in the development of new scintillation materials for PET application.

  7. Influence of Co-57 and CT Transmission Measurements on the Quantification Accuracy and Partial Volume Effect of a Small Animal PET Scanner.

    Science.gov (United States)

    Mannheim, Julia G; Schmid, Andreas M; Pichler, Bernd J

    2017-12-01

    Non-invasive in vivo positron emission tomography (PET) provides high detection sensitivity in the nano- to picomolar range and in addition to other advantages, the possibility to absolutely quantify the acquired data. The present study focuses on the comparison of transmission data acquired with an X-ray computed tomography (CT) scanner or a Co-57 source for the Inveon small animal PET scanner (Siemens Healthcare, Knoxville, TN, USA), as well as determines their influences on the quantification accuracy and partial volume effect (PVE). A special focus included the impact of the performed calibration on the quantification accuracy. Phantom measurements were carried out to determine the quantification accuracy, the influence of the object size on the quantification, and the PVE for different sphere sizes, along the field of view and for different contrast ratios. An influence of the emission activity on the Co-57 transmission measurements was discovered (deviations up to 24.06 % measured to true activity), whereas no influence of the emission activity on the CT attenuation correction was identified (deviations influenced by the applied calibration factor and by the object size. The PVE demonstrated a dependency on the sphere size, the position within the field of view, the reconstruction and correction algorithms and the count statistics. Depending on the reconstruction algorithm, only ∼30-40 % of the true activity within a small sphere could be resolved. The iterative 3D reconstruction algorithms uncovered substantially increased recovery values compared to the analytical and 2D iterative reconstruction algorithms (up to 70.46 % and 80.82 % recovery for the smallest and largest sphere using iterative 3D reconstruction algorithms). The transmission measurement (CT or Co-57 source) to correct for attenuation did not severely influence the PVE. The analysis of the quantification accuracy and the PVE revealed an influence of the object size, the reconstruction

  8. 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.

  9. Temperature dependence of APD-based PET scanners

    International Nuclear Information System (INIS)

    Keereman, Vincent; Van Holen, Roel; Vandenberghe, Stefaan; Vanhove, Christian

    2013-01-01

    Purpose: Solid state detectors such as avalanche photodiodes (APDs) are increasingly being used in PET detectors. One of the disadvantages of APDs is the strong decrease of their gain factor with increasing ambient temperature. The light yield of most scintillation crystals also decreases when ambient temperature is increased. Both effects lead to considerable temperature dependence of the performance of APD-based PET scanners. In this paper, the authors propose a model for this dependence and the performance of the LabPET8 APD-based small animal PET scanner is evaluated at different temperatures.Methods: The model proposes that the effect of increasing temperature on the energy histogram of an APD-based PET scanner is a compression of the histogram along the energy axis. The energy histogram of the LabPET system was acquired at 21 °C and 25 °C to verify the validity of this model. Using the proposed model, the effect of temperature on system sensitivity was simulated for different detector temperature coefficients and temperatures. Subsequently, the effect of short term and long term temperature changes on the peak sensitivity of the LabPET system was measured. The axial sensitivity profile was measured at 21 °C and 24 °C following the NEMA NU 4-2008 standard. System spatial resolution was also evaluated. Furthermore, scatter fraction, count losses and random coincidences were evaluated at different temperatures. Image quality was also investigated.Results: As predicted by the model, the photopeak energy at 25 °C is lower than at 21 °C with a shift of approximately 6% per °C. Simulations showed that this results in an approximately linear decrease of sensitivity when temperature is increased from 21 °C to 24 °C and energy thresholds are constant. Experimental evaluation of the peak sensitivity at different temperatures showed a strong linear correlation for short term (2.32 kcps/MBq/°C = 12%/°C, R = −0.95) and long term (1.92 kcps/MBq/°C = 10%/

  10. Evaluation of PET Scanner Performance in PET/MR and PET/CT Systems: NEMA Tests

    Directory of Open Access Journals (Sweden)

    Mustafa Demir

    2018-02-01

    Full Text Available Objective: 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. Methods: 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. Results: 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. Conclusion: 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.

  11. Control of pet animals.

    Science.gov (United States)

    Collins, T F

    1976-06-26

    Pet animals play an important and valuable role in human society, but irresponsible ownership has created problems of surplus animals, threats to health, pollution, nuisance, cruelty and neglect. Urgent and drastic action is required to deal with the situation, and the measures proposed include the appointment of dog wardens, limitation of numbers, enclosure and leash laws, and subsidised spay clinics.

  12. Evaluation of the performance of the YAP-(S)PET scanner and its application in neuroscience

    International Nuclear Information System (INIS)

    Belcari, Nicola; Guerra, Alberto Del; Bartoli, Antonietta; Bianchi, Daniele; Lazzarotti, Marco; Sensi, Luca; Menichetti, Luca; Lecchi, Michela; Erba, Paola A.; Mariani, Giuliano; Corsini, Giovanni U.; Sgado, Paola

    2007-01-01

    This paper presents the performance evaluation of the small animal scanner YAP-(S)PET, both in PET and SPECT modalities following preliminary NEMA standards for small animal PET. Data are taken with a new version of the scanner that is installed at the IFC-CNR in Pisa (Italy) within the framework of the Center of Excellence AmbiSEN of the University of Pisa. This paper also reports some preliminary SPECT applications in neuroscience using 123 I-FP-CIT (DaTSCAN)

  13. Quantification accuracy and partial volume effect in dependence of the attenuation correction of a state-of-the-art small animal PET scanner

    International Nuclear Information System (INIS)

    Mannheim, Julia G; Judenhofer, Martin S; Schmid, Andreas; Pichler, Bernd J; Tillmanns, Julia; Stiller, Detlef; Sossi, Vesna

    2012-01-01

    Quantification accuracy and partial volume effect (PVE) of the Siemens Inveon PET scanner were evaluated. The influence of transmission source activities (40 and 160 MBq) on the quantification accuracy and the PVE were determined. Dynamic range, object size and PVE for different sphere sizes, contrast ratios and positions in the field of view (FOV) were evaluated. The acquired data were reconstructed using different algorithms and correction methods. The activity level of the transmission source and the total emission activity in the FOV strongly influenced the attenuation maps. Reconstruction algorithms, correction methods, object size and location within the FOV had a strong influence on the PVE in all configurations. All evaluated parameters potentially influence the quantification accuracy. Hence, all protocols should be kept constant during a study to allow a comparison between different scans. (paper)

  14. The TT-PET project: a thin TOF-PET scanner based on fast novel silicon pixel detectors

    Science.gov (United States)

    Bandi, Y.; Benoit, M.; Cadoux, F. R.; Forshaw, D. C.; Hänni, R.; Hayakawa, D.; Iacobucci, G.; Michal, S.; Miucci, A.; Paolozzi, L.; Ratib, O.; Ripiccini, E.; Tognina, C.; Valerio, P.; Weber, M.

    2018-01-01

    The TT-PET project aims at developing a compact Time-of-flight PET scanner with 30ps time resolution, capable of withstanding high magnetic fields and allowing for integration in a traditional MRI scanner, providing complimentary real-time PET images. The very high timing resolution of the TT-PET scanner is achieved thanks to a new generation of Silicon-Germanium (Si-Ge) amplifiers, which are embedded in monolithic pixel sensors. The scanner is composed of 16 detection towers as well as cooling blocks, arranged in a ring structure. The towers are composed of multiple ultra-thin pixel modules stacked on top of each other. Making it possible to perform depth of interaction measurements and maximize the spatial resolution along the line of flight of the two photons emitted within a patient. This will result in improved image quality, contrast, and uniformity while drastically reducing backgrounds within the scanner. Allowing for a reduction in the amount of radioactivity delivered to the patient. Due to an expected data rate of about 250 MB/s a custom readout system for high data throughput has been developed, which includes noise filtering and reduced data pressure. The realisation of a first scanner prototype for small animals is foreseen by 2019. A general overview of the scanner will be given including, technical details concerning the detection elements, mechanics, DAQ readout, simulation and results.

  15. Technology challenges in small animal PET imaging

    International Nuclear Information System (INIS)

    Lecomte, Roger

    2004-01-01

    Positron Emission Tomography (PET) is a non-invasive nuclear imaging modality allowing biochemical processes to be investigated in vivo with sensitivity in the picomolar range. For this reason, PET has the potential to play a major role in the emerging field of molecular imaging by enabling the study of molecular pathways and genetic processes in living animals non-invasively. The challenge is to obtain a spatial resolution that is appropriate for rat and mouse imaging, the preferred animal models for research in biology, while achieving a sensitivity adequate for real-time measurement of rapid dynamic processes in vivo without violating tracer kinetic principles. An overview of the current state of development of dedicated small animal PET scanners is given, and selected applications are reported and discussed with respect to performance and significance to research in biology

  16. Attenuation correction for small animal PET tomographs

    Energy Technology Data Exchange (ETDEWEB)

    Chow, Patrick L [David Geffen School of Medicine at UCLA, Crump Institute for Molecular Imaging, University of California, 700 Westwood Plaza, Los Angeles, CA 90095 (United States); Rannou, Fernando R [Departamento de Ingenieria Informatica, Universidad de Santiago de Chile (USACH), Av. Ecuador 3659, Santiago (Chile); Chatziioannou, Arion F [David Geffen School of Medicine at UCLA, Crump Institute for Molecular Imaging, University of California, 700 Westwood Plaza, Los Angeles, CA 90095 (United States)

    2005-04-21

    Attenuation correction is one of the important corrections required for quantitative positron emission tomography (PET). This work will compare the quantitative accuracy of attenuation correction using a simple global scale factor with traditional transmission-based methods acquired either with a small animal PET or a small animal x-ray computed tomography (CT) scanner. Two phantoms (one mouse-sized and one rat-sized) and two animal subjects (one mouse and one rat) were scanned in CTI Concorde Microsystem's microPET (registered) Focus{sup TM} for emission and transmission data and in ImTek's MicroCAT{sup TM} II for transmission data. PET emission image values were calibrated against a scintillation well counter. Results indicate that the scale factor method of attenuation correction places the average measured activity concentration about the expected value, without correcting for the cupping artefact from attenuation. Noise analysis in the phantom studies with the PET-based method shows that noise in the transmission data increases the noise in the corrected emission data. The CT-based method was accurate and delivered low-noise images suitable for both PET data correction and PET tracer localization.

  17. Importance of Attenuation Correction (AC) for Small Animal PET Imaging

    DEFF Research Database (Denmark)

    El Ali, Henrik H.; Bodholdt, Rasmus Poul; Jørgensen, Jesper Tranekjær

    2012-01-01

    was performed. Methods: Ten NMRI nude mice with subcutaneous implantation of human breast cancer cells (MCF-7) were scanned consecutively in small animal PET and CT scanners (MicroPETTM Focus 120 and ImTek’s MicroCATTM II). CT-based AC, PET-based AC and uniform AC methods were compared. Results: The activity...

  18. Performance evaluation of a LYSO-based PET scanner for monitoring of dose delivery in hadrontherapy

    Science.gov (United States)

    Fabbiani, E.; Belcari, N.; Camarlinghi, N.; Del Guerra, A.; Ferretti, S.; Kraan, A.; Panetta, D.; Sportelli, G.; Rosso, V.

    2015-12-01

    The DoPET scanner is a compact positron emission tomography (PET) device. It has been developed for monitoring the range of charged particles during therapy with hadron beams. Previous works have focused on the development and upgrade of the device and on data analysis. In this paper, a full performance characterization of the DoPET system in terms of the energy resolution, spatial resolution, sensitivity, uniformity, and noise equivalent count rate is reported. All measurements refer to an adapted version of the National Electrical Manufacturers Association (NEMA) NU 4 - 2008 protocol, which was written originally for small animal PET systems. Since DoPET is a dual head planar system, it requires a modified characterisation procedure with respect to those described for ring geometries as in the NEMA NU 4 - 2008 protocol. The presented procedure may be of interest for any other PET system with a similar geometry as DoPET.

  19. Imaging system models for small-bore DOI-PET scanners

    International Nuclear Information System (INIS)

    Takahashi, Hisashi; Kobayashi, Tetsuya; Yamaya, Taiga; Murayama, Hideo; Kitamura, Keishi; Hasegawa, Tomoyuki; Suga, Mikio

    2006-01-01

    Depth-of-interaction (DOI) information, which improves resolution uniformity in the field of view (FOV), is expected to lead to high-sensitivity PET scanners with small-bore detector rings. We are developing small-bore PET scanners with DOI detectors arranged in hexagonal or overlapped tetragonal patterns for small animal imaging or mammography. It is necessary to optimize the imaging system model because these scanners exhibit irregular detector sampling. In this work, we compared two imaging system models: (a) a parallel sub-LOR model in which the detector response functions (DRFs) are assumed to be uniform along the line of responses (LORs) and (b) a sub-crystal model in which each crystal is divided into a set of smaller volumes. These two models were applied to the overlapped tetragonal scanner (FOV 38.1 mm in diameter) and the hexagonal scanner (FOV 85.2 mm in diameter) simulated by GATE. We showed that the resolution non-uniformity of system model (b) was improved by 40% compared with that of system model (a) in the overlapped tetragonal scanner and that the resolution non-uniformity of system model (a) was improved by 18% compared with that of system model (b) in the hexagonal scanner. These results indicate that system model (b) should be applied to the overlapped tetragonal scanner and system model (a) should be applied to the hexagonal scanner. (author)

  20. Development of an inexpensive, low attenuation styrofoam primate chair for use in a PET scanner.

    Science.gov (United States)

    Kortekaas, R; van Waarde, A; Maguire, R P; Leenders, K L; Elsinga, P H

    2004-04-01

    Pharmacokinetic modelling of radiotracers for positron emission tomography (PET) imaging of neuroreceptors can be performed with time-activity data for brain and blood. We aimed to develop an alternative to withdrawal of arterial blood samples for acquisition of a blood curve. A supportive primate chair was constructed out of styrofoam and fixed to the head portion of the bed of a PET scanner. A lightly anaesthetised rhesus monkey was positioned in the chair in a sitting position and injected with the radiotracer. The styrofoam chair provided sufficient support for the monkey. The presence of the chair in the PET scanner caused negligible attenuation of radiation, allowing simultaneous acquisition of dynamic data from the subject's brain and heart. We conclude that a styrofoam primate chair is an ideal tool to measure blood and brain data from a rhesus monkey with PET. Invasiveness to the animal is reduced, as well as experimenter time.

  1. A dedicated tool for PET scanner simulations using FLUKA

    International Nuclear Information System (INIS)

    Ortega, P.G.; Boehlen, T.T.; Cerutti, F.; Chin, M.P.W.; Ferrari, A.; Mancini, C.; Vlachoudis, V.; Mairani, A.; Sala, Paola R.

    2013-06-01

    Positron emission tomography (PET) is a well-established medical imaging technique. It is based on the detection of pairs of annihilation gamma rays from a beta+-emitting radionuclide, usually inoculated in the body via a biologically active molecule. Apart from its wide-spread use for clinical diagnosis, new applications are proposed. This includes notably the usage of PET for treatment monitoring of radiation therapy with protons and ions. PET is currently the only available technique for non-invasive monitoring of ion beam dose delivery, which was tested in several clinical pilot studies. For hadrontherapy, the distribution of positron emitters, produced by the ion beam, can be analyzed to verify the correct treatment delivery. The adaptation of previous PET scanners to new environments and the necessity of more precise diagnostics by better image quality triggered the development of new PET scanner designs. The use of Monte Carlo (MC) codes is essential in the early stages of the scanner design to simulate the transport of particles and nuclear interactions from therapeutic ion beams or radioisotopes and to predict radiation fields in tissues and radiation emerging from the patient. In particular, range verification using PET is based on the comparison of detected and simulated activity distributions. The accuracy of the MC code for the relevant physics processes is obviously essential for such applications. In this work we present new developments of the physics models with importance for PET monitoring and integrated tools for PET scanner simulations for FLUKA, a fully-integrated MC particle-transport code, which is widely used for an extended range of applications (accelerator shielding, detector and target design, calorimetry, activation, dosimetry, medical physics, radiobiology, ...). The developed tools include a PET scanner geometry builder and a dedicated scoring routine for coincident event determination. The geometry builder allows the efficient

  2. A combined positron emission tomography (PET)- electron paramagnetic resonance imaging (EPRI) system: initial evaluation of a prototype scanner.

    Science.gov (United States)

    Tseytlin, Mark; Stolin, Alexander V; Guggilapu, Priyaankadevi; Bobko, Andrey A; Khramtsov, Valery V; Tseytlin, Oxana; Raylman, Raymond R

    2018-04-20

    The advent of hybrid scanners, combining complementary modalities, has revolutionized imaging; enhancing clinical practice and biomedical research. In this project, we investigated the melding of two complementary, functional imaging methods: positron emission tomography (PET) and electron paramagnetic resonance imaging (EPRI). The PET radiotracers can provide important information about cellular parameters, such as glucose metabolism. While EPR probes can provide assessment of tissue microenvironment, measuring parameters such as oxygenation and pH, for example. A combined PET/EPRI scanner has the promise to provide new insights not attainable with current imagers by simultaneous acquisition of multiple components of tissue microenvironments. In this investigation, a prototype system was created by combing two existing scanners, modified for simultaneous imaging. Specifically, a silicon photomultiplier (SiPM) based PET scanner ring designed as a portable scanner was combined with an EPRI scanner designed for the imaging of small animals. The ability of the system to obtain simultaneous images was assessed with a small phantom consisting of four cylinders containing both PET and EPR tracers. The resulting images demonstrated the ability to obtain contemporaneous PET and ERP images without cross-modality interference. The next step in this project is the construction of pre-clinical PET/EPRI scanner for multi-parametric assessment of physiologically important parameters of tissue microenvironments. . © 2018 Institute of Physics and Engineering in Medicine.

  3. Use of an in-field-of-view shield to improve count rate performance of the single crystal layer high-resolution research tomograph PET scanner for small animal brain scans

    International Nuclear Information System (INIS)

    Boellaard, R; Jong, H W A M de; Molthoff, C F M; Buijs, F; Lenox, M; Nutt, R; Lammertsma, A A

    2003-01-01

    The count rate performance of the single LSO crystal layer high-resolution research tomograph (HRRT-S) PET scanner is limited by the processing speed of its electronics. Therefore, the feasibility of using an in-field-of-view (in-FOV) shield to improve the noise equivalent count rates (NECR) for small animal brain studies was investigated. The in-FOV shield consists of a lead tube of 12 cm length, 6 cm inner diameter and 9 mm wall thickness. It is large enough to shield the activity in the body of a rat or mouse. First, the effect of this shield on NECR was studied. Secondly, a number of experiments were performed to assess the effects of the shield on the accuracy of transmission scan data and, next, on reconstructed activity distribution in the brain. For activities below 150 MBq NECR improved only by 5-10%. For higher activities NECR maxima of 1.2E4 cps at 200 MBq and 2.2E4 cps at 370 MBq were found without and with shield, respectively. Listmode data taken without shield, however, were corrupted for activities above 75 MBq due to data overrun problems (time tag losses) of the electronics. When the shield was used data overrun was avoided up to activities of 150 MBq. For the unshielded part of the phantom, transmission scan data were the same with and without shield. The estimated scatter contribution was approximately 8.5% without and 5.5% with shield. Reconstructed emission data showed a difference up to 5% in the unshielded part of the phantom at 5 mm or more from the edge of the shielding. Of this 5% about 3% results from the difference in the uncorrected scatter contribution. In conclusion, an in-FOV shield can be used successfully in an HRRT PET scanner to improve NECR and accuracy of small animal brain studies. The latter is especially important when high activities are required for tracers with low brain uptake or when multiple animals are scanned simultaneously. (note)

  4. A Very High Spatial Resolution Detector for Small Animal PET

    International Nuclear Information System (INIS)

    Kanai Shah, M.S.

    2007-01-01

    Positron Emission Tomography (PET) is an in vivo analog of autoradiography and has the potential to become a powerful new tool in imaging biological processes in small laboratory animals. PET imaging of small animals can provide unique information that can help in advancement of human disease models as well as drug development. Clinical PET scanners used for human imaging are bulky, expensive and do not have adequate spatial resolution for small animal studies. Hence, dedicated, low cost instruments are required for conducting small animal studies with higher spatial resolution than what is currently achieved with clinical as well as dedicated small animal PET scanners. The goal of the proposed project is to investigate a new all solid-state detector design for small animal PET imaging. Exceptionally high spatial resolution, good timing resolution, and excellent energy resolution are expected from the proposed detector design. The Phase I project was aimed at demonstrating the feasibility of producing high performance solid-state detectors that provide high sensitivity, spatial resolution, and timing characteristics. Energy resolution characteristics of the new detector were also investigated. The goal of the Phase II project is to advance the promising solid-state detector technology for small animal PET and determine its full potential. Detectors modules will be built and characterized and finally, a bench-top small animal PET system will be assembled and evaluated

  5. Initial clinical test of a breast-PET scanner.

    Science.gov (United States)

    Raylman, Raymond R; Abraham, Jame; Hazard, Hannah; Koren, Courtney; Filburn, Shannon; Schreiman, Judith S; Kurian, Sobha; Majewski, Stan; Marano, Gary D

    2011-02-01

    The goal of this initial clinical study was to test a new positron emission/tomography imager and biopsy system (PEM/PET) in a small group of selected subjects to assess its clinical imaging capabilities. Specifically, the main task of this study is to determine whether the new system can successfully be used to produce images of known breast cancer and compare them to those acquired by standard techniques. The PEM/PET system consists of two pairs of rotating radiation detectors located beneath a patient table. The scanner has a spatial resolution of ∼2 mm in all three dimensions. The subjects consisted of five patients diagnosed with locally advanced breast cancer ranging in age from 40 to 55 years old scheduled for pre-treatment, conventional whole body PET imaging with F-18 Fluorodeoxyglucose (FDG). The primary lesions were at least 2 cm in diameter. The images from the PEM/PET system demonstrated that this system is capable of identifying some lesions not visible in standard mammograms. Furthermore, while the relatively large lesions imaged in this study where all visualised by a standard whole body PET/CT scanner, some of the morphology of the tumours (ductal infiltration, for example) was better defined with the PEM/PET system. Significantly, these images were obtained immediately following a standard whole body PET scan. The initial testing of the new PEM/PET system demonstrated that the new system is capable of producing good quality breast-PET images compared standard methods. © 2011 The Authors. Journal of Medical Imaging and Radiation Oncology © 2011 The Royal Australian and New Zealand College of Radiologists.

  6. Simulation of time curves in small animal PET using GATE

    International Nuclear Information System (INIS)

    Simon, Luc; Strul, Daniel; Santin, Giovanni; Krieguer, Magalie; Morel, Christian

    2004-01-01

    The ClearPET project of the Crystal Clear Collaboration (CCC) is building spin-off technology for high resolution small animal Positron Emission Tomography (PET). Monte Carlo simulation is essential for optimizing the specifications of these systems with regards to their most important characteristics, such as spatial resolution, sensitivity, or count rate performance. GATE, the Geant4 Application for Tomographic Emission simulates the passing of time during real acquisitions, allowing to handle dynamic systems such as decaying source distributions or moving detectors. GATE output is analyzed on an event-by-event basis. The time associated with each single event allows to sort coincidences and to model dead-time. This leads to the study of time curves for a prospective small animal PET scanner design. The count rates of true, and random coincidences are discussed together with the corresponding Noise Equivalent Count (NEC) rates as a function of some PET scanner specifications such as detector dead time, or coincidence time window

  7. 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

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

    International Nuclear Information System (INIS)

    García Hernández, Trinitat; Vicedo González, Aurora; Brualla González, Luis; Granero Cabañero, Domingo; Ferrer Rebolleda, Jose; Sánchez Jurado, Raúl; Puig Cozar Santiago, Maria del; Roselló Ferrando, Joan

    2016-01-01

    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 ( 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 performance

  9. Looking forward to a PET scanner designed for non-human primates

    International Nuclear Information System (INIS)

    Tanaka, Keiji

    1992-01-01

    The cerebral cortex of non-human primates has been divided, mainly by anatomical techniques, into an enormous number of areas. We are looking forward to a PET scanner designed for non-human primates, with a hope to determine active brain regions when the animal does various cognitive tasks. This measurement with PET can be combined with single cell recordings and anatomical tracer studies in non-human primates. Another big hope is to detect a change of active regions as the learning advances. (author)

  10. Small animal PET and its applications in biomedical research

    International Nuclear Information System (INIS)

    Qiu Feichan

    2004-01-01

    Positron emission tomography (PET) is a nuclear medical imaging technique that permits the use of positron-labeled molecular imaging probes for non-invasive assays of biochemical processes. As the leading technology in nuclear medicine, PET has extended its applications from the clinical field to the study of small laboratory animals. In recent years, the development of new detector technology has dramatically improved the spatial resolution and image quality of small animal PET scanner, which is being used increasingly as a basic tool in modern biomedical research. In particular, small animal PET will play an important role in drug discovery and development, in the study of small animal models of human diseases, in characterizing gene expression and in many other ways. (authors)

  11. Experimental Evaluation of Depth-of-Interaction Correction in a Small-Animal Positron Emission Tomography Scanner

    OpenAIRE

    Green, Michael V.; Ostrow, Harold G.; Seidel, Jurgen; Pomper, Martin G.

    2010-01-01

    Human and small-animal positron emission tomography (PET) scanners with cylindrical geometry and conventional detectors exhibit a progressive reduction in radial spatial resolution with increasing radial distance from the geometric axis of the scanner. This “depth-of-interaction” (DOI) effect is sufficiently deleterious that many laboratories have devised novel schemes to reduce the magnitude of this effect and thereby yield PET images of greater quantitative accuracy. Here we examine experim...

  12. Trends in PET scanner ownership and leasing by nonradiologist physicians.

    Science.gov (United States)

    Agarwal, Rajan; Levin, David C; Parker, Laurence; Rao, Vijay M

    2010-03-01

    The aim of this study was to examine growth trends in ownership or leasing of private-office PET scanners by nonradiologist physicians. The Medicare Part B Physician/Supplier Procedure Summary Master Files for 2002 through 2007 were used to collect the following data for each PET-related Current Procedural Terminology((R)) code: 1) annual procedure volume, 2) places of service for the procedures, and 3) specialties of the physicians filing the claims. To determine ownership or leasing, only technical and global claims that occurred in the nonhospital, private-office setting were included in the study. Professional component-only claims were not included. Procedure volume and growth trends were compared between radiologists and other specialties. Between 2002 and 2007, radiologist-owned Medicare PET scans increased by 259%, whereas nonradiologist-owned or nonradiologist-leased scans grew by 737%. Five specialty groups accounted for 95% of all nonradiologist PET volume in 2007: internal medicine subspecialties (28,324 studies in 2007), medical oncology (14,320 studies), cardiology (13,724 studies), radiation oncology (9,563 studies), and primary care (2,398 studies). In 2002, of all Medicare PET examinations performed on units owned or leased by physicians, the share for nonradiologists was 13%; their share rose to 24% in 2007. Although a large percentage of PET scans in private offices are done by radiologists, the growth rate among nonradiologists was far higher between 2002 and 2007 (259% for the former, 737% for the latter). The disproportionately rapid growth of PET scans performed on units owned by nonradiologists raises concern about self-referral at a time when policymakers are struggling to contain costs and reduce radiation exposure.

  13. Oxygen-15 labeled CO2, O2, and CO PET in small animals: evaluation using a 3D-mode microPET scanner and impact of reconstruction algorithms.

    Science.gov (United States)

    Horitsugi, Genki; Watabe, Tadashi; Kanai, Yasukazu; Ikeda, Hayato; Kato, Hiroki; Naka, Sadahiro; Ishibashi, Mana; Matsunaga, Keiko; Isohashi, Kayako; Shimosegawa, Eku; Hatazawa, Jun

    2017-10-27

    Positron emission tomography (PET) studies using 15 O-labeled CO 2 , O 2 , and CO have been used in humans to evaluate cerebral blood flow (CBF), the cerebral oxygen extraction fraction (OEF), and the cerebral metabolic rate of oxygen (CMRO 2 ) and cerebral blood volume (CBV), respectively. In preclinical studies, however, PET studies using 15 O-labeled gases are not widely performed because of the technical difficulties associated with handling labeled gases with a short half-life. The aims of the present study were to evaluate the scatter fraction using 3D-mode micro-PET for 15 O-labeled gas studies and the influence of reconstruction algorithms on quantitative values. Nine male SD rats were studied using the steady state inhalation method for 15 O-labeled gases with arterial blood sampling. The resulting PET images were reconstructed using filtered back projection (FBP), ordered-subset expectation maximization (OSEM) 2D, or OSEM 3D followed by maximum a posteriori (OSEM3D-MAP). The quantitative values for each brain region and each reconstruction method were calculated by applying different reconstruction methods. The quantitative values for the whole brain as calculated using FBP were 46.6 ± 12.5 mL/100 mL/min (CBF), 63.7 ± 7.2% (OEF), 5.72 ± 0.34 mL/100 mL/min (CMRO 2 ), and 5.66 ± 0.34 mL/100 mL (CBV), respectively. The CBF and CMRO 2 values were significantly higher when the OSEM2D and OSEM3D-MAP reconstruction methods were used, compared with FBP, whereas the OEF values were significantly lower when reconstructed using OSEM3D-MAP. We evaluated the difference in quantitative values among the reconstruction algorithms using 3D-mode micro-PET. The iterative reconstruction method resulted in significantly higher quantitative values for CBF and CMRO 2 , compared with the values calculated using the FBP reconstruction method.

  14. Monte Carlo modeling of a clinical PET scanner by using the GATE dedicated computer code; Modelagem Monte Carlo de um PET Scanner clinico utilizando o codigo dedicado GATE

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, Igor Fagner; Lima, Fernando Roberto de Andrade, E-mail: falima@cnen.gov.b [Universidade Federal de Pernambuco (DEN/UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear; Universidade de Pernambuco (UPE), Recife, PE (Brazil). Escola Politecnica; Vieira, Jose Wilson [Universidade Federal de Pernambuco (DEN/UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear; Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil)

    2011-10-26

    This paper demonstrates more possible detailed the GATE simulated architecture involved in the 4D modeling of a General Electric PET scanner, the Advance. So, it were used data present in the literature on the configuration of GE modelled PET. The obtained results which were the 3D components of PET creation, and the simulation of 4D phenomena as the source decay and the gantry whirl, exhibit the potential of tool in emission tomograph modelling

  15. The performance characteristics of the Philips Gemini PET/CT scanner

    International Nuclear Information System (INIS)

    O'Keefe, G.J.; Papenfuss, A.T.; Scott, A.M.; Rowe, C.C.

    2002-01-01

    Full text: The Department of Nuclear Medicine, Centre for PET at the ARMC is commissioning a next generation PET/CT scanner based on gadolinium silicic dioxide (GSO) crystal technology to replace the BGO crystal PET scanner that has been in operation since 1992. The Gemini PET/CT scanner is a fully 3D PET system which offers significantly increased resolution and sensitivity allowing wholebody scans in under 30 minutes. Until the late 90's, PET scanners were largely used with septa for neurological imaging and the performance characteristics of PET scanners were presented according to the NEMA-NU2-94 standard which specifically addresses the performance of PET scanners for neurological applications. PET is now largely used without septa for oncological imaging and as such, the NEMA-NU2-94 standard does not adequately reflect performance. The NEMA-NU2-2001 standard was designed to incorporate the effects of out-of-FOV activity and its contribution to performance by virtue of the increased scatter and randoms that result when performing wholebody scans without the use of septa. As part of the acceptance program of the Allegro/Gemini systems, the NEMA-NU2-2001 standard will be used to characterise the spatial resolution, sensitivity, randoms and scatter contributions and the Noise Equivalent Count rate (NECr). These results will be presented and compared with the ECAT 951/31R performance characteristics. Copyright (2002) The Australian and New Zealand Society of Nuclear Medicine Inc

  16. Scatter Characterization and Correction for Simultaneous Multiple Small-Animal PET Imaging

    NARCIS (Netherlands)

    Prasad, Rameshwar; Zaidi, Habib

    The rapid growth and usage of small-animal positron emission tomography (PET) in molecular imaging research has led to increased demand on PET scanner's time. One potential solution to increase throughput is to scan multiple rodents simultaneously. However, this is achieved at the expense of

  17. TraPET: High performance small animal PET with trapezoidal phoswich detector

    International Nuclear Information System (INIS)

    Chung, Yong Hyun; Hwang, Ji Yeon; Baek, Cheol-Ha; An, Su Jung; Kim, Hyun-Il; Kim, Kwang Hyun

    2011-01-01

    In recent years, small-animal PET scanners with depth of interaction (DOI) capability have been developed for molecular imaging research. The aim of this study is to perform simulations to design a high performance small-animal PET, called TraPET. TraPET has an inner diameter of 76.21 mm with 6 dual-layer phoswich detector modules. Each module is composed of a 5.0-mm-thick trapezoidal-monolithic-LSO crystal with a front face (surface facing toward the inside of the scanner) of 44.0x44.0 mm 2 and a back face of 50.0x50.0 mm 2 and a 25x25 array of LuYAP crystals with a 2.0x2.0 mm 2 sensitive area with a 15.0 mm thickness. DOI information is extracted by a pulse shape discrimination method. The ability of event positioning in the trapezoidal-monolithic-LSO was evaluated by modeling the light distribution in the crystal using DETECT2000 and a 16x16 array of silicon photo-multipliers (SiPMs), with a 3.0 mm pixel size, selected as the photo-sensor. Also, the sensitivity and gap filling effect between modules were simulated using the Monte Carlo code, GATE. The new detector showed higher and more uniform sensitivity, as compared to scanners with rectangular-shaped detectors, because the trapezoidal-monolithic-LSO minimizes the dead space within the detector ring. In conclusion, our new detector proved to be a reliable design for small-animal PET with high spatial resolution by DOI information, and high sensitivity by high filling fraction.

  18. NEMA and clinical evaluation of a novel brain PET-CT scanner

    Science.gov (United States)

    Grogg, Kira S.; Toole, Terrence; Ouyang, Jinsong; Zhu, Xuping; Normandin, Marc; Johnson, Keith; Alpert, Nathaniel M.; Fakhri, Georges El

    2016-01-01

    The aim of this study was to determine the performance of a novel mobile human brain/small animal PET-CT system, developed by Photo Diagnostic Systems Inc. The scanner has a 35.7-cm diameter bore and a 22-cm axial extent. The detector ring has 7 modules each with 3×4 cerium-doped lutetium yttrium orthosilicate crystal blocks, each consisting of 22×22 outer layer and 21×21 inner layer crystals, each layer 1 cm thick. Light is collected by 12×12 SiPMs. The integrated CT can be used for attenuation correction and anatomical localization. The scanner was designed as a low-cost device that nevertheless produces high-quality PET images with the unique capability of battery-powered propulsion, enabling use in many settings. Methods Spatial resolution, sensitivity and noise-equivalent count rate (NECR) were measured based on the National Electrical Manufacturers Association NU2-2012 procedures. Reconstruction was done with tight energy and timing cuts: 400-650 keV and 7ns, and loose cuts: 350-700 keV and 10ns. Additional image quality measurements were made from phantoms, human, and animal studies. Performance was compared to a reference scanner (ECAT Exact HR+) with comparable imaging properties. Results The full-width half-max transverse resolution at 1 cm (10 cm) radius is 3.2 mm (5.2 mm radial, 3.1 mm tangential) and the axial resolution is 3.5 mm (4.0 mm). For tight (loose) cuts, a sensitivity of 7.5 (11.7) kcps/MBq at the center increases to 8.8 (13.9) kcps/MBq at a 10 cm radial offset. The maximum NECR of 19.5 (22.7) kcps was achieved for an activity concentration of 2.9 kBq/ml. Contrast recovery for 4:1 hot cylinder to warm background was 76% for the 25 mm diameter cylinder, but decreased with decreasing cylinder size. The quantitation agrees within 2% of the known activity distribution and concentration. Brain phantom and human scans have shown agreement in SUV values and image quality with the HR+. Conclusion We have characterized the performance of the NeuroPET

  19. TOF-PET scanner configurations for quality assurance in proton therapy: a patient case study

    NARCIS (Netherlands)

    Dendooven, Peter; Diblen, Faruk; Buitenhuis, H.J.T.; Oxley, D.C.; Biegun, A.K.; van der Borden, A.J.; Brandenburg, Sijtze; Cambraia Lopes, P.; van der Schaaf, A.; Schaart, D.R.; Vandenberghe, S.; van 't Veld, A.A.

    2014-01-01

    In order to determine the clinical benefit of positron emission tomography (PET) for dose delivery verification in proton therapy, we performed a patient case study comparing in-situ with in-room time-of-flight (TOF) PET. For the in-situ option, we consider both a (limited-angle) clinical scanner

  20. Monte Carlo modeling of a clinical PET scanner by using the GATE dedicated computer code

    International Nuclear Information System (INIS)

    Vieira, Igor Fagner; Lima, Fernando Roberto de Andrade

    2011-01-01

    This paper demonstrates more possible detailed the GATE simulated architecture involved in the 4D modeling of a General Electric PET scanner, the Advance. So, it were used data present in the literature on the configuration of GE modelled PET. The obtained results which were the 3D components of PET creation, and the simulation of 4D phenomena as the source decay and the gantry whirl, exhibit the potential of tool in emission tomograph modelling

  1. Pet food recalls and pet food contaminants in small animals.

    Science.gov (United States)

    Bischoff, Karyn; Rumbeiha, Wilson K

    2012-03-01

    Most pet foods are safe, but incidents of chemical contamination occur and lead to illness and recalls. There were 11 major pet food recalls in the United States between 1996 and 2010 that were due to chemical contaminants or misformulations: 3 aflatoxin, 3 excess vitamin D3, 1 excess methionine, 3 inadequate thiamine, and 1 adulteration with melamine and related compounds and an additional 2 warnings concerning a Fanconilike renal syndrome in dogs after ingesting large amounts of chicken jerky treat products. This article describes clinical findings and treatment of animals exposed to the most common pet food contaminants.

  2. Use of a clinical PET/MR scanner for preclinical research with first results

    International Nuclear Information System (INIS)

    Chary, Karthik; Teuho, Jarmo; Virta, Jenni; Sipilä, Hannu; Saunavaara, Virva; Roivainen, Anne; Teräs, Mika

    2014-01-01

    This study was performed to evaluate the feasibility of preclinical imaging in a clinical PET/MR system. Preliminary sequences were evaluated for establishing preclinical protocols for rat brain and rabbit knee. Rats were placed in a stereotactic holder, allowing a 30 minute scan time before re-administration of anesthesia. In-house developed warm-water heating system was used to maintain the body temperature at 37.5°C, monitored using an MR-compatible rectal probe. Brain imaging was performed with a dedicated 4 channel phased array receive coil (RAPID Biomedical GmbH, Germany). High resolution coronal images were acquired using conventional T1-SE (0.30x0.30x1.2mm) and T2-TSE (0.23x0.23x0.7mm) with a total scan time of 30 min. PET/MR imaging was performed on two white rabbits. The rabbits were imaged in a custom wooden holder. PET/MR protocol had a total duration of 45 minutes. No external heating was used. MR protocol consisted of anatomical T1, T2 and PDW of the knees, using a SENSE Flex-S coil. MR attenuation correction (MRAC) was acquired with 3D T1-FFE using three-class segmentation. A dynamic 30 minute PET acquisition was started on injection of 33.8MBq of Ga-68. Animal coils enabled high resolution images to be acquired in reasonable acquisition time with regards to animal handling and anesthesia. T1 and T2 images provided good differentiation of anatomy in the rat brain with high contrast. T1, T2 and PDW images of the rabbit knee had high resolution and differentiation of anatomical structures. MRAC was able to distinguish the knees and the body contour. Image fusion of PET and MR was able to localize the infection, which was confirmed by a physician. Pre-clinical imaging with the Ingenuity TF was deemed feasible, although PET imaging is limited by the resolution of the scanner. The preliminary sequences were successfully implemented for future studies on the Ingenuity TF.

  3. Use of a clinical PET/MR scanner for preclinical research with first results

    Energy Technology Data Exchange (ETDEWEB)

    Chary, Karthik; Teuho, Jarmo; Virta, Jenni; Sipilä, Hannu; Saunavaara, Virva; Roivainen, Anne; Teräs, Mika [Turku PET Centre, Turku University Hospital, Turku (Finland)

    2014-07-29

    This study was performed to evaluate the feasibility of preclinical imaging in a clinical PET/MR system. Preliminary sequences were evaluated for establishing preclinical protocols for rat brain and rabbit knee. Rats were placed in a stereotactic holder, allowing a 30 minute scan time before re-administration of anesthesia. In-house developed warm-water heating system was used to maintain the body temperature at 37.5°C, monitored using an MR-compatible rectal probe. Brain imaging was performed with a dedicated 4 channel phased array receive coil (RAPID Biomedical GmbH, Germany). High resolution coronal images were acquired using conventional T1-SE (0.30x0.30x1.2mm) and T2-TSE (0.23x0.23x0.7mm) with a total scan time of 30 min. PET/MR imaging was performed on two white rabbits. The rabbits were imaged in a custom wooden holder. PET/MR protocol had a total duration of 45 minutes. No external heating was used. MR protocol consisted of anatomical T1, T2 and PDW of the knees, using a SENSE Flex-S coil. MR attenuation correction (MRAC) was acquired with 3D T1-FFE using three-class segmentation. A dynamic 30 minute PET acquisition was started on injection of 33.8MBq of Ga-68. Animal coils enabled high resolution images to be acquired in reasonable acquisition time with regards to animal handling and anesthesia. T1 and T2 images provided good differentiation of anatomy in the rat brain with high contrast. T1, T2 and PDW images of the rabbit knee had high resolution and differentiation of anatomical structures. MRAC was able to distinguish the knees and the body contour. Image fusion of PET and MR was able to localize the infection, which was confirmed by a physician. Pre-clinical imaging with the Ingenuity TF was deemed feasible, although PET imaging is limited by the resolution of the scanner. The preliminary sequences were successfully implemented for future studies on the Ingenuity TF.

  4. 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.

  5. Geo-PET: A novel generic organ-pet for small animal organs and tissues

    Science.gov (United States)

    Sensoy, Levent

    Reconstructed tomographic image resolution of small animal PET imaging systems is improving with advances in radiation detector development. However the trend towards higher resolution systems has come with an increase in price and system complexity. Recent developments in the area of solid-state photomultiplication devices like silicon photomultiplier arrays (SPMA) are creating opportunities for new high performance tools for PET scanner design. Imaging of excised small animal organs and tissues has been used as part of post-mortem studies in order to gain detailed, high-resolution anatomical information on sacrificed animals. However, this kind of ex-vivo specimen imaging has largely been limited to ultra-high resolution muCT. The inherent limitations to PET resolution have, to date, excluded PET imaging from these ex-vivo imaging studies. In this work, we leverage the diminishing physical size of current generation SPMA designs to create a very small, simple, and high-resolution prototype detector system targeting ex-vivo tomographic imaging of small animal organs and tissues. We investigate sensitivity, spatial resolution, and the reconstructed image quality of a prototype small animal PET scanner designed specifically for imaging of excised murine tissue and organs. We aim to demonstrate that a cost-effective silicon photomultiplier (SiPM) array based design with thin crystals (2 mm) to minimize depth of interaction errors might be able to achieve sub-millimeter resolution. We hypothesize that the substantial decrease in sensitivity associated with the thin crystals can be compensated for with increased solid angle detection, longer acquisitions, higher activity and wider acceptance energy windows (due to minimal scatter from excised organs). The constructed system has a functional field of view (FoV) of 40 mm diameter, which is adequate for most small animal specimen studies. We perform both analytical (3D-FBP) and iterative (ML-EM) methods in order to

  6. Scatter characterization and correction for simultaneous multiple small-animal PET imaging

    OpenAIRE

    Prasad Rameshwar; Zaidi Habib; Zaidi Habib; Zaidi Habib

    2013-01-01

    Purpose: The rapid growth and usage of small animal positron emission tomography (PET) in molecular imaging research has led to increased demand on PET scanner's time. One potential solution to increase throughput is to scan multiple rodents simultaneously. However this is achieved at the expense of deterioration of image quality and loss of quantitative accuracy owing to enhanced effects of photon attenuation and Compton scattering. The purpose of this work is first to characterize the magni...

  7. The simulation of a data acquisition system for a proposed high resolution PET scanner

    International Nuclear Information System (INIS)

    Rotolo, C.; Larwill, M.; Chappa, S.; Ordonez, C.

    1993-10-01

    The simulation of a specific data acquisition (DAQ) system architecture for a proposed high resolution Positron Emission Tomography (PET) scanner is discussed. Stochastic processes are used extensively to model PET scanner signal timing and probable DAQ circuit limitations. Certain architectural parameters, along with stochastic parameters, are varied to quantatively study the resulting output under various conditions. The inclusion of the DAQ in the model represents a novel method of more complete simulations of tomograph designs, and could prove to be of pivotal importance in the optimization of such designs

  8. The simulation of a data acquisition system for a proposed high resolution PET scanner

    Energy Technology Data Exchange (ETDEWEB)

    Rotolo, C.; Larwill, M.; Chappa, S. [Fermi National Accelerator Lab., Batavia, IL (United States); Ordonez, C. [Chicago Univ., IL (United States)

    1993-10-01

    The simulation of a specific data acquisition (DAQ) system architecture for a proposed high resolution Positron Emission Tomography (PET) scanner is discussed. Stochastic processes are used extensively to model PET scanner signal timing and probable DAQ circuit limitations. Certain architectural parameters, along with stochastic parameters, are varied to quantatively study the resulting output under various conditions. The inclusion of the DAQ in the model represents a novel method of more complete simulations of tomograph designs, and could prove to be of pivotal importance in the optimization of such designs.

  9. Effects of injected dose, BMI and scanner type on NECR and image noise in PET imaging

    International Nuclear Information System (INIS)

    Chang Tingting; Chang Guoping; Clark, John W Jr; Kohlmyer, Steve; Rohren, Eric; Mawlawi, Osama R

    2011-01-01

    Noise equivalent count rate (NECR) and image noise are two different but related metrics that have been used to predict and assess image quality, respectively. The aim of this study is to investigate, using patient studies, the relationships between injected dose (ID), body mass index (BMI) and scanner type on NECR and image noise measurements in PET imaging. Two groups of 90 patients each were imaged on a GE DSTE and a DRX PET/CT scanner, respectively. The patients in each group were divided into nine subgroups according to three BMI (20-24.9, 25-29.9, 30-45 kg m -2 ) and three ID (296-444, 444-555, 555-740 MBq) ranges, resulting in ten patients/subgroup. All PET data were acquired in 3D mode and reconstructed using the VuePoint HD (registered) fully 3D OSEM algorithm (2 iterations, 21(DRX) or 20 (DSTE) subsets). NECR and image noise measurements for bed positions covering the liver were calculated for each patient. NECR was calculated from the trues, randoms and scatter events recorded in the DICOM header of each patient study, while image noise was determined as the standard deviation of 50 non-neighboring voxels in the liver of each patient. A t-test compared the NECR and image noise for different scanners but with the same BMI and ID. An ANOVA test on the other hand was used to compare the results of patients with different BMI but the same ID and scanner type as well as different ID but the same BMI and scanner type. As expected the t-test showed a significant difference in NECR between the two scanners for all BMI and ID subgroups. However, contrary to what is expected no such findings were observed for image noise measurement. The ANOVA results showed a statistically significant difference in both NECR and image noise among the different BMI for each ID and scanner subgroup. However, there was no statistically significant difference in NECR and image noise across different ID for each BMI and scanner subgroup. Although the GE DRX PET/CT scanner has better

  10. Emotional Support Animals, Service Animals, and Pets on Campus

    Science.gov (United States)

    Von Bergen, C. W.

    2015-01-01

    For decades, universities have been accommodating physically disabled students who require guide dogs and other types of service animals. Within the past several years, however, mentally disabled students have increasingly petitioned colleges with no-pet policies to permit them to bring their animals on campus because they need a companion or…

  11. Quantitative image reconstruction for total-body PET imaging using the 2-meter long EXPLORER scanner.

    Science.gov (United States)

    Zhang, Xuezhu; Zhou, Jian; Cherry, Simon R; Badawi, Ramsey D; Qi, Jinyi

    2017-03-21

    The EXPLORER project aims to build a 2 meter long total-body PET scanner, which will provide extremely high sensitivity for imaging the entire human body. It will possess a range of capabilities currently unavailable to state-of-the-art clinical PET scanners with a limited axial field-of-view. The huge number of lines-of-response (LORs) of the EXPLORER poses a challenge to the data handling and image reconstruction. The objective of this study is to develop a quantitative image reconstruction method for the EXPLORER and compare its performance with current whole-body scanners. Fully 3D image reconstruction was performed using time-of-flight list-mode data with parallel computation. To recover the resolution loss caused by the parallax error between crystal pairs at a large axial ring difference or transaxial radial offset, we applied an image domain resolution model estimated from point source data. To evaluate the image quality, we conducted computer simulations using the SimSET Monte-Carlo toolkit and XCAT 2.0 anthropomorphic phantom to mimic a 20 min whole-body PET scan with an injection of 25 MBq 18 F-FDG. We compare the performance of the EXPLORER with a current clinical scanner that has an axial FOV of 22 cm. The comparison results demonstrated superior image quality from the EXPLORER with a 6.9-fold reduction in noise standard deviation comparing with multi-bed imaging using the clinical scanner.

  12. Quantitative image reconstruction for total-body PET imaging using the 2-meter long EXPLORER scanner

    Science.gov (United States)

    Zhang, Xuezhu; Zhou, Jian; Cherry, Simon R.; Badawi, Ramsey D.; Qi, Jinyi

    2017-03-01

    The EXPLORER project aims to build a 2 meter long total-body PET scanner, which will provide extremely high sensitivity for imaging the entire human body. It will possess a range of capabilities currently unavailable to state-of-the-art clinical PET scanners with a limited axial field-of-view. The huge number of lines-of-response (LORs) of the EXPLORER poses a challenge to the data handling and image reconstruction. The objective of this study is to develop a quantitative image reconstruction method for the EXPLORER and compare its performance with current whole-body scanners. Fully 3D image reconstruction was performed using time-of-flight list-mode data with parallel computation. To recover the resolution loss caused by the parallax error between crystal pairs at a large axial ring difference or transaxial radial offset, we applied an image domain resolution model estimated from point source data. To evaluate the image quality, we conducted computer simulations using the SimSET Monte-Carlo toolkit and XCAT 2.0 anthropomorphic phantom to mimic a 20 min whole-body PET scan with an injection of 25 MBq 18F-FDG. We compare the performance of the EXPLORER with a current clinical scanner that has an axial FOV of 22 cm. The comparison results demonstrated superior image quality from the EXPLORER with a 6.9-fold reduction in noise standard deviation comparing with multi-bed imaging using the clinical scanner.

  13. Image quality of Zr-89 PET imaging in the Siemens microPET Focus 220 preclinical scanner.

    Science.gov (United States)

    Bradshaw, Tyler J; Voorbach, Martin J; Reuter, David R; Giamis, Anthony M; Mudd, Sarah R; Beaver, John D

    2016-06-01

    Zr-89 positron emission tomography (PET) is a valuable tool for understanding the biodistribution and pharmacokinetics of antibody-based therapeutics. We compared the image quality of Zr-89 PET and F-18 PET in the Siemens microPET Focus 220 preclinical scanner using different reconstruction methods. Image quality metrics were measured in various Zr-89 and F-18 PET phantoms, including the NEMA NU 4-2008 image quality phantom. Images were reconstructed using various algorithms. Zr-89 PET had greater image noise, inferior spatial resolution, and greater spillover than F-18 PET, but comparable recovery coefficients for cylinders of various diameters. Of the reconstruction methods, OSEM3D resulted in the lowest noise, highest recovery coefficients, best spatial resolution, but also the greatest spillover. Scatter correction results were found to be sensitive to varying object sizes. Zr-89 PET image quality was inferior to that of F-18, and no single reconstruction method was superior in all aspects of image quality.

  14. Spatial resolution of the HRRT PET scanner using 3D-OSEM PSF reconstruction

    DEFF Research Database (Denmark)

    Olesen, Oline Vinter; Sibomana, Merence; Keller, Sune Høgild

    2009-01-01

    The spatial resolution of the Siemens High Resolution Research Tomograph (HRRT) dedicated brain PET scanner installed at Copenhagen University Hospital (Rigshospitalet) was measured using a point-source phantom with high statistics. Further, it was demonstrated how the newly developed 3D-OSEM PSF...

  15. Image reconstruction using TV algorithm for a C-shaped breast PET scanner

    International Nuclear Information System (INIS)

    Akazawa, Ayako; Kitamura, Keishi; Yamada, Yosihiro; Yamakawa, Yoshiyuki; Hashizume, Nobuya; Kumazawa, Yoshihiko

    2010-01-01

    Our group is now developing a C-shaped breast positron emission tomography (PET) scanner. The 'C' shape allows it to be positioned closely around the breast, effectively increasing both resolution and sensitivity. Although the open end of the detector unit allows the arm to be placed there and the C-shaped design of the scanner accommodates a variety of patient physiques, there are some artifacts on the reconstructed image. In this work, we investigated the algorithm using TV (Total Variation) minimization method with iterative image reconstruction. Image reconstruction using TV algorithm performs the optimization program that leads to the minimum of the gradient image TV. The proposed method is able to reduce artifacts in reconstructed image even with projection data from few views or limited angle. We evaluated image quality using phantom data with the C-shaped breast PET scanner and achieved to control the artifacts. (author)

  16. A dedicated breast-PET/CT scanner: Evaluation of basic performance characteristics.

    Science.gov (United States)

    Raylman, Raymond R; Van Kampen, Will; Stolin, Alexander V; Gong, Wenbo; Jaliparthi, Gangadhar; Martone, Peter F; Smith, Mark F; Sarment, David; Clinthorne, Neal H; Perna, Mark

    2018-04-01

    Application of advanced imaging techniques, such as PET and x ray CT, can potentially improve detection of breast cancer. Unfortunately, both modalities have challenges in the detection of some lesions. The combination of the two techniques, however, could potentially lead to an overall improvement in diagnostic breast imaging. The purpose of this investigation is to test the basic performance of a new dedicated breast-PET/CT. The PET component consists of a rotating pair of detectors. Its performance was evaluated using the NEMA NU4-2008 protocols. The CT component utilizes a pulsed x ray source and flat panel detector mounted on the same gantry as the PET scanner. Its performance was assessed using specialized phantoms. The radiation dose to a breast during CT imaging was explored by the measurement of free-in-air kerma and air kerma measured at the center of a 16 cm-diameter PMMA cylinder. Finally, the combined capabilities of the system were demonstrated by imaging of a micro-hot-rod phantom. Overall, performance of the PET component is comparable to many pre-clinical and other dedicated breast-PET scanners. Its spatial resolution is 2.2 mm, 5 mm from the center of the scanner using images created with the single-sliced-filtered-backprojection algorithm. Peak NECR is 24.6 kcps; peak sensitivity is 1.36%; the scatter fraction is 27%. Spatial resolution of the CT scanner is 1.1 lp/mm at 10% MTF. The free-in-air kerma is 2.33 mGy, while the PMMA-air kerma is 1.24 mGy. Finally, combined imaging of a micro-hot-rod phantom illustrated the potential utility of the dual-modality images produced by the system. The basic performance characteristics of a new dedicated breast-PET/CT scanner are good, demonstrating that its performance is similar to current dedicated PET and CT scanners. The potential value of this system is the capability to produce combined duality-modality images that could improve detection of breast disease. The next stage in development of this system

  17. Design considerations and construction of a small animal PET prototype

    International Nuclear Information System (INIS)

    Tzanakos, G.; Nikolaou, M.; Drakoulakos, D.; Karamitros, D.; Kontaxakis, G.; Logaras, E.; Panayiotakis, G.; Pavlopoulos, S.; Skiadas, M.; Spyrou, G.; Thireou, T.; Vamvakas, D.

    2006-01-01

    We are developing a small animal PET scanner consisting of two block detectors, each made of 216 BGO crystals of dimensions 3.75 mmx3.75 mmx20 mm, cylindrically arranged and coupled to a position-sensitive photomultiplier tube (R2486 PSPMT). Our design was based on a very detailed Monte Carlo, that simulates the function of a PET scanner from the system level down to the individual γ-ray detectors. We have made laboratory measurements of the individual detector performance as well as measurements of characteristics of the PSPMTs. The two detector blocks which will form the basic tomographic unit have been assembled. We are developing electronics to individually process (amplify and digitize) anode signals, and use field programmable gate arrays (FPGAs) in the position determination and energy measurement of the γ-rays. At present, as an intermediate step, we are using the electronics supplied from Hamamatsu to study various aspects of the system and produce initial images

  18. A device to measure the effects of strong magnetic fields on the image resolution of PET scanners

    CERN Document Server

    Burdette, D; Chesi, E; Clinthorne, N H; Cochran, E; Honscheid, K; Huh, S S; Kagan, H; Knopp, M; Lacasta, C; Mikuz, M; Schmalbrock, P; Studen, A; Weilhammer, P

    2009-01-01

    Very high resolution images can be achieved in small animal PET systems utilizing solid state silicon pad detectors. As these systems approach sub-millimeter resolutions, the range of the positron is becoming the dominant contribution to image blur. The size of the positron range effect depends on the initial positron energy and hence the radioactive tracer used. For higher energy positron emitters, such as and , which are gaining importance in small animal studies, the width of the annihilation point distribution dominates the spatial resolution. This positron range effect can be reduced by embedding the field of view of the PET scanner in a strong magnetic field. In order to confirm this effect experimentally, we developed a high resolution PET instrument based on silicon pad detectors that can operate in a 7 T magnetic field. In this paper, we describe the instrument and present initial results of a study of the effects of magnetic fields up to 7 T on PET image resolution for and point sources.

  19. Experimental Evaluation of Depth-of-Interaction Correction in a Small-Animal Positron Emission Tomography Scanner

    Directory of Open Access Journals (Sweden)

    Michael V. Green

    2010-11-01

    Full Text Available Human and small-animal positron emission tomography (PET scanners with cylindrical geometry and conventional detectors exhibit a progressive reduction in radial spatial resolution with increasing radial distance from the geometric axis of the scanner. This “depth-of-interaction” (DOI effect is sufficiently deleterious that many laboratories have devised novel schemes to reduce the magnitude of this effect and thereby yield PET images of greater quantitative accuracy. Here we examine experimentally the effects of a particular DOI correction method (dual-scintillator phoswich detectors with pulse shape discrimination implemented in a small-animal PET scanner by comparing the same phantom and same mouse images with and without DOI correction. The results suggest that even this relatively coarse, two-level estimate of radial gamma ray interaction position significantly reduces the DOI parallax error. This study also confirms two less appreciated advantages of DOI correction: a reduction in radial distortion and radial source displacement as a source is moved toward the edge of the field of view and a resolution improvement detectable in the central field of view likely owing to improved spatial sampling.

  20. Experimental evaluation of depth-of-interaction correction in a small-animal positron emission tomography scanner.

    Science.gov (United States)

    Green, Michael V; Ostrow, Harold G; Seidel, Jurgen; Pomper, Martin G

    2010-12-01

    Human and small-animal positron emission tomography (PET) scanners with cylindrical geometry and conventional detectors exhibit a progressive reduction in radial spatial resolution with increasing radial distance from the geometric axis of the scanner. This "depth-of-interaction" (DOI) effect is sufficiently deleterious that many laboratories have devised novel schemes to reduce the magnitude of this effect and thereby yield PET images of greater quantitative accuracy. Here we examine experimentally the effects of a particular DOI correction method (dual-scintillator phoswich detectors with pulse shape discrimination) implemented in a small-animal PET scanner by comparing the same phantom and same mouse images with and without DOI correction. The results suggest that even this relatively coarse, two-level estimate of radial gamma ray interaction position significantly reduces the DOI parallax error. This study also confirms two less appreciated advantages of DOI correction: a reduction in radial distortion and radial source displacement as a source is moved toward the edge of the field of view and a resolution improvement detectable in the central field of view likely owing to improved spatial sampling.

  1. Simulation study of a D-shape PET scanner for improved sensitivity and reduced cost in whole-body imaging

    Science.gov (United States)

    Ahmed, Abdella M.; Tashima, Hideaki; Yamaya, Taiga

    2017-05-01

    Much research effort is being made to increase the sensitivity and improve the imaging performance of positron emission tomography (PET) scanners. Conventionally, sensitivity can be increased by increasing the number of detector rings in the axial direction (but at high cost) or reducing the diameter of the scanner (with the disadvantages of reducing the space for patients and degrading the spatial resolution due to the parallax error). In this study, we proposed a PET scanner with a truncated ring and an array of detectors that can be arranged in a straight line below the bed. We called this system ‘D-PET’ as it resembles the letter ‘D’ when it is rotated by 90° in the counterclockwise direction. The basic design idea was to cut the unused space under the patient’s bed; this area is usually not in use in clinical diagnosis. We conducted Monte Carlo simulations of the D-PET scanner and compared its performance with a cylindrical PET scanner. The scanners were constructed from 4-layer depth-of-interaction detectors which consisted of a 16  ×  16  ×  4 LYSO crystal array with dimensions of 2.85  ×  2.85  ×  5 mm3. The results showed that the D-PET had an increase in sensitivity and peak-NECR of 30% and 18%, respectively. The D-PET had low noise in the reconstructed images throughout the field-of-view compared to the cylindrical PET. These were achieved while keeping sufficient space for the patient, and also without a severe effect on the spatial resolution. Furthermore, the number of detectors (and hence the cost) of the D-PET scanner was reduced by 12% compared to the cylindrical PET scanner.

  2. Noise equivalent count measurements in a neuro-PET scanner with retractable septa

    International Nuclear Information System (INIS)

    Bailey, D.L.; Jones, T.; Spinks, T.J.; Gilardi, M.C.; Townsend, D.W.

    1990-01-01

    This paper reports on the removal of interplane septa in a PET scanner that enables acquisition of all possible lines of response (3D mode) in an effort to maximize the available number of detected events. One problem with this method at high countrates, however, is a markedly increased deadtime and randoms rate, which has a deleterious effect on data quality. The noise-equivalent countrate (NEC) performance of a neuro-PET scanner has been determined with and without interplane septa on uniform cylindrical phantoms of differing radii and in human studies to assess the optimum countrate conditions that realize the maximum gain. In the brain, the effective gain in NEC performance for 3D ranges from >5 at low countrates to ∼3.3 at 200 kcps (equivalent to 37 kcps in 2D). The gains of the 3D method assessed by this analysis are significant, and are shown to be highly dependent on countrate and object dimensions

  3. An ASIC implementation of digital front-end electronics for a high resolution PET scanner

    International Nuclear Information System (INIS)

    Newport, D.F.; Young, J.W.

    1993-01-01

    AN Application Specific Integrated Circuit (ASIC) has been designed and fabricated which implements many of the current functions found in the digital front-end electronics for a high resolution Positron Emission Tomography (PET) scanner. The ASIC performs crystal selection, energy qualification, time correction, and event counting functions for block technology high resolution PET scanners. Digitized x and y position, event energy, and time information are used by the ASIC to determine block crystal number, qualify the event based on energy, and correct the event time. In addition, event counting and block dead time calculations are performed for system dead time corrections. A loadable sequencer for controlling the analog front-end electronics is also implemented. The ASIC is implemented in a 37,000 gate, 1.0 micron CMOS gate-array and is capable of handling 4 million events/second while reducing parts count, cost, and power consumption over current board-level designs

  4. Comparison of lesion detection and quantitation of tracer uptake between PET from a simultaneously acquiring whole-body PET/MR hybrid scanner and PET from PET/CT

    International Nuclear Information System (INIS)

    Wiesmueller, Marco; Schmidt, Daniela; Beck, Michael; Kuwert, Torsten; Gall, Carl C. von; Quick, Harald H.; Navalpakkam, Bharath; Lell, Michael M.; Uder, Michael; Ritt, Philipp

    2013-01-01

    PET/MR hybrid scanners have recently been introduced, but not yet validated. The aim of this study was to compare the PET components of a PET/CT hybrid system and of a simultaneous whole-body PET/MR hybrid system with regard to reproducibility of lesion detection and quantitation of tracer uptake. A total of 46 patients underwent a whole-body PET/CT scan 1 h after injection and an average of 88 min later a second scan using a hybrid PET/MR system. The radioactive tracers used were 18 F-deoxyglucose (FDG), 18 F-ethylcholine (FEC) and 68 Ga-DOTATATE (Ga-DOTATATE). The PET images from PET/CT (PET CT ) and from PET/MR (PET MR ) were analysed for tracer-positive lesions. Regional tracer uptake in these foci was quantified using volumes of interest, and maximal and average standardized uptake values (SUV max and SUV avg , respectively) were calculated. Of the 46 patients, 43 were eligible for comparison and statistical analysis. All lesions except one identified by PET CT were identified by PET MR (99.2 %). In 38 patients (88.4 %), the same number of foci were identified by PET CT and by PET MR . In four patients, more lesions were identified by PET MR than by PET CT , in one patient PET CT revealed an additional focus compared to PET MR . The mean SUV max and SUV avg of all lesions determined by PET MR were by 21 % and 11 % lower, respectively, than the values determined by PET CT (p CT and PET MR were minor, but statistically significant. Nevertheless, a more detailed study of the quantitative accuracy of PET MR and the factors governing it is needed to ultimately assess its accuracy in measuring tissue tracer concentrations. (orig.)

  5. Point-like radioactive source with multiple absorber capsules for evaluating PET scanners.

    Science.gov (United States)

    Hasegawa, Tomoyuki; Yoshida, Eiji; Sato, Yasushi; Oda, Keiichi; Wada, Yasuhiro; Yamada, Takahiro; Yamaya, Taiga; Murayama, Hideo; Saito, Kyoko

    2010-06-01

    Radioactive sources for evaluating sensitivity and uncertainty in the radioactivity measurements performed using PET scanners must be equipped with absorber materials that ensure the annihilation of positrons. Attenuation and scattering owing to the absorber materials produce uncertainty in the performance evaluation. The aim of this study is to propose a point-like radioactive source with multiple absorber capsules, for which evaluation can be independent of scatter and attenuation owing to the source absorbers. The point-like source consists of a small spherical radioactive part and a set of successively sized cylindrical aluminum absorber capsules. Data were collected for different total absorber thicknesses. By an extrapolation technique, the effects of the source absorbers were eliminated. Sensitivity and uncertainty in the radioactivity measurements of PET scanners were evaluated with this technique. Sensitivity and uncertainty of radioactivity measurement to the point-like radioactive source were evaluated successfully with this method. The proposed point-like radioactive source is useful for evaluating performance characteristics of PET scanners in a way that is independent of the effects of the source absorbers.

  6. Characterization of 176Lu background in LSO-based PET scanners

    Science.gov (United States)

    Conti, Maurizio; Eriksson, Lars; Rothfuss, Harold; Sjoeholm, Therese; Townsend, David; Rosenqvist, Göran; Carlier, Thomas

    2017-05-01

    LSO and LYSO are today the most common scintillators used in positron emission tomography. Lutetium contains traces of 176Lu, a radioactive isotope that decays β - with a cascade of γ photons in coincidence. Therefore, Lutetium-based scintillators are characterized by a small natural radiation background. In this paper, we investigate and characterize the 176Lu radiation background via experiments performed on LSO-based PET scanners. LSO background was measured at different energy windows and different time coincidence windows, and by using shields to alter the original spectrum. The effect of radiation background in particularly count-starved applications, such as 90Y imaging, is analysed and discussed. Depending on the size of the PET scanner, between 500 and 1000 total random counts per second and between 3 and 5 total true coincidences per second were measured in standard coincidence mode. The LSO background counts in a Siemens mCT in the standard PET energy and time windows are in general negligible in terms of trues, and are comparable to that measured in a BGO scanner of similar size.

  7. 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.)

  8. Multi-contrast attenuation map synthesis for PET/MR scanners: assessment on FDG and Florbetapir PET tracers

    Energy Technology Data Exchange (ETDEWEB)

    Burgos, Ninon [University College London, Translational Imaging Group, Centre for Medical Image Computing, London (United Kingdom); Cardoso, M.J.; Modat, Marc; Ourselin, Sebastien [University College London, Translational Imaging Group, Centre for Medical Image Computing, London (United Kingdom); University College London, Dementia Research Centre, Institute of Neurology, London (United Kingdom); Thielemans, Kris; Dickson, John [University College London, Institute of Nuclear Medicine, London (United Kingdom); Schott, Jonathan M. [University College London, Dementia Research Centre, Institute of Neurology, London (United Kingdom); Atkinson, David [University College London, Centre for Medical Imaging, London (United Kingdom); Arridge, Simon R. [University College London, Centre for Medical Image Computing, London (United Kingdom); Hutton, Brian F. [University College London, Institute of Nuclear Medicine, London (United Kingdom); University of Wollongong, Centre for Medical Radiation Physics, Wollongong, NSW (Australia)

    2015-08-15

    Positron Emission Tomography/Magnetic Resonance Imaging (PET/MR) scanners are expected to offer a new range of clinical applications. Attenuation correction is an essential requirement for quantification of PET data but MRI images do not directly provide a patient-specific attenuation map. Methods We further validate and extend a Computed Tomography (CT) and attenuation map (μ-map) synthesis method based on pre-acquired MRI-CT image pairs. The validation consists of comparing the CT images synthesised with the proposed method to the original CT images. PET images were acquired using two different tracers ({sup 18}F-FDG and {sup 18}F-florbetapir). They were then reconstructed and corrected for attenuation using the synthetic μ-maps and compared to the reference PET images corrected with the CT-based μ-maps. During the validation, we observed that the CT synthesis was inaccurate in areas such as the neck and the cerebellum, and propose a refinement to mitigate these problems, as well as an extension of the method to multi-contrast MRI data. Results With the improvements proposed, a significant enhancement in CT synthesis, which results in a reduced absolute error and a decrease in the bias when reconstructing PET images, was observed. For both tracers, on average, the absolute difference between the reference PET images and the PET images corrected with the proposed method was less than 2%, with a bias inferior to 1%. Conclusion With the proposed method, attenuation information can be accurately derived from MRI images by synthesising CT using routine anatomical sequences. MRI sequences, or combination of sequences, can be used to synthesise CT images, as long as they provide sufficient anatomical information. (orig.)

  9. Using triple gamma coincidences with a pixelated semiconductor Compton-PET scanner: a simulation study

    Science.gov (United States)

    Kolstein, M.; Chmeissani, M.

    2016-01-01

    The Voxel Imaging PET (VIP) Pathfinder project presents a novel design using pixelated semiconductor detectors for nuclear medicine applications to achieve the intrinsic image quality limits set by physics. The conceptual design can be extended to a Compton gamma camera. The use of a pixelated CdTe detector with voxel sizes of 1 × 1 × 2 mm3 guarantees optimal energy and spatial resolution. However, the limited time resolution of semiconductor detectors makes it impossible to use Time Of Flight (TOF) with VIP PET. TOF is used in order to improve the signal to noise ratio (SNR) by using only the most probable portion of the Line-Of-Response (LOR) instead of its entire length. To overcome the limitation of CdTe time resolution, we present in this article a simulation study using β+-γ emitting isotopes with a Compton-PET scanner. When the β+ annihilates with an electron it produces two gammas which produce a LOR in the PET scanner, while the additional gamma, when scattered in the scatter detector, provides a Compton cone that intersects with the aforementioned LOR. The intersection indicates, within a few mm of uncertainty along the LOR, the origin of the beta-gamma decay. Hence, one can limit the part of the LOR used by the image reconstruction algorithm.

  10. 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...

  11. Processing optimization with parallel computing for the J-PET scanner

    Directory of Open Access Journals (Sweden)

    Krzemień Wojciech

    2015-12-01

    Full Text Available The Jagiellonian Positron Emission Tomograph (J-PET collaboration is developing a prototype time of flight (TOF-positron emission tomograph (PET detector based on long polymer scintillators. This novel approach exploits the excellent time properties of the plastic scintillators, which permit very precise time measurements. The very fast field programmable gate array (FPGA-based front-end electronics and the data acquisition system, as well as low- and high-level reconstruction algorithms were specially developed to be used with the J-PET scanner. The TOF-PET data processing and reconstruction are time and resource demanding operations, especially in the case of a large acceptance detector that works in triggerless data acquisition mode. In this article, we discuss the parallel computing methods applied to optimize the data processing for the J-PET detector. We begin with general concepts of parallel computing and then we discuss several applications of those techniques in the J-PET data processing.

  12. Small animal simultaneous PET/MRI: initial experiences in a 9.4 T microMRI

    Science.gov (United States)

    Harsha Maramraju, Sri; Smith, S. David; Junnarkar, Sachin S.; Schulz, Daniela; Stoll, Sean; Ravindranath, Bosky; Purschke, Martin L.; Rescia, Sergio; Southekal, Sudeepti; Pratte, Jean-François; Vaska, Paul; Woody, Craig L.; Schlyer, David J.

    2011-04-01

    We developed a non-magnetic positron-emission tomography (PET) device based on the rat conscious animal PET that operates in a small-animal magnetic resonance imaging (MRI) scanner, thereby enabling us to carry out simultaneous PET/MRI studies. The PET detector comprises 12 detector blocks, each being a 4 × 8 array of lutetium oxyorthosilicate crystals (2.22 × 2.22 × 5 mm3) coupled to a matching non-magnetic avalanche photodiode array. The detector blocks, housed in a plastic case, form a 38 mm inner diameter ring with an 18 mm axial extent. Custom-built MRI coils fit inside the positron-emission tomography (PET) device, operating in transceiver mode. The PET insert is integrated with a Bruker 9.4 T 210 mm clear-bore diameter MRI scanner. We acquired simultaneous PET/MR images of phantoms, of in vivo rat brain, and of cardiac-gated mouse heart using [11C]raclopride and 2-deoxy-2-[18F]fluoro-d-glucose PET radiotracers. There was minor interference between the PET electronics and the MRI during simultaneous operation, and small effects on the signal-to-noise ratio in the MR images in the presence of the PET, but no noticeable visual artifacts. Gradient echo and high-duty-cycle spin echo radio frequency (RF) pulses resulted in a 7% and a 28% loss in PET counts, respectively, due to high PET counts during the RF pulses that had to be gated out. The calibration of the activity concentration of PET data during MR pulsing is reproducible within less than 6%. Our initial results demonstrate the feasibility of performing simultaneous PET and MRI studies in adult rats and mice using the same PET insert in a small-bore 9.4 T MRI.

  13. Pragmatic fully 3D image reconstruction for the MiCES mouse imaging PET scanner

    International Nuclear Information System (INIS)

    Lee, Kisung; Kinahan, Paul E; Fessler, Jeffrey A; Miyaoka, Robert S; Janes, Marie; Lewellen, Tom K

    2004-01-01

    We present a pragmatic approach to image reconstruction for data from the micro crystal elements system (MiCES) fully 3D mouse imaging positron emission tomography (PET) scanner under construction at the University of Washington. Our approach is modelled on fully 3D image reconstruction used in clinical PET scanners, which is based on Fourier rebinning (FORE) followed by 2D iterative image reconstruction using ordered-subsets expectation-maximization (OSEM). The use of iterative methods allows modelling of physical effects (e.g., statistical noise, detector blurring, attenuation, etc), while FORE accelerates the reconstruction process by reducing the fully 3D data to a stacked set of independent 2D sinograms. Previous investigations have indicated that non-stationary detector point-spread response effects, which are typically ignored for clinical imaging, significantly impact image quality for the MiCES scanner geometry. To model the effect of non-stationary detector blurring (DB) in the FORE+OSEM(DB) algorithm, we have added a factorized system matrix to the ASPIRE reconstruction library. Initial results indicate that the proposed approach produces an improvement in resolution without an undue increase in noise and without a significant increase in the computational burden. The impact on task performance, however, remains to be evaluated

  14. Errors in MR-based attenuation correction for brain imaging with PET/MR scanners

    International Nuclear Information System (INIS)

    Rota Kops, Elena; Herzog, Hans

    2013-01-01

    Aim: Attenuation correction of PET data acquired by hybrid MR/PET scanners remains a challenge, even if several methods for brain and whole-body measurements have been developed recently. A template-based attenuation correction for brain imaging proposed by our group is easy to handle and delivers reliable attenuation maps in a short time. However, some potential error sources are analyzed in this study. We investigated the choice of template reference head among all the available data (error A), and possible skull anomalies of the specific patient, such as discontinuities due to surgery (error B). Materials and methods: An anatomical MR measurement and a 2-bed-position transmission scan covering the whole head and neck region were performed in eight normal subjects (4 females, 4 males). Error A: Taking alternatively one of the eight heads as reference, eight different templates were created by nonlinearly registering the images to the reference and calculating the average. Eight patients (4 females, 4 males; 4 with brain lesions, 4 w/o brain lesions) were measured in the Siemens BrainPET/MR scanner. The eight templates were used to generate the patients' attenuation maps required for reconstruction. ROI and VOI atlas-based comparisons were performed employing all the reconstructed images. Error B: CT-based attenuation maps of two volunteers were manipulated by manually inserting several skull lesions and filling a nasal cavity. The corresponding attenuation coefficients were substituted with the water's coefficient (0.096/cm). Results: Error A: The mean SUVs over the eight templates pairs for all eight patients and all VOIs did not differ significantly one from each other. Standard deviations up to 1.24% were found. Error B: After reconstruction of the volunteers' BrainPET data with the CT-based attenuation maps without and with skull anomalies, a VOI-atlas analysis was performed revealing very little influence of the skull lesions (less than 3%), while the filled

  15. Errors in MR-based attenuation correction for brain imaging with PET/MR scanners

    Science.gov (United States)

    Rota Kops, Elena; Herzog, Hans

    2013-02-01

    AimAttenuation correction of PET data acquired by hybrid MR/PET scanners remains a challenge, even if several methods for brain and whole-body measurements have been developed recently. A template-based attenuation correction for brain imaging proposed by our group is easy to handle and delivers reliable attenuation maps in a short time. However, some potential error sources are analyzed in this study. We investigated the choice of template reference head among all the available data (error A), and possible skull anomalies of the specific patient, such as discontinuities due to surgery (error B). Materials and methodsAn anatomical MR measurement and a 2-bed-position transmission scan covering the whole head and neck region were performed in eight normal subjects (4 females, 4 males). Error A: Taking alternatively one of the eight heads as reference, eight different templates were created by nonlinearly registering the images to the reference and calculating the average. Eight patients (4 females, 4 males; 4 with brain lesions, 4 w/o brain lesions) were measured in the Siemens BrainPET/MR scanner. The eight templates were used to generate the patients' attenuation maps required for reconstruction. ROI and VOI atlas-based comparisons were performed employing all the reconstructed images. Error B: CT-based attenuation maps of two volunteers were manipulated by manually inserting several skull lesions and filling a nasal cavity. The corresponding attenuation coefficients were substituted with the water's coefficient (0.096/cm). ResultsError A: The mean SUVs over the eight templates pairs for all eight patients and all VOIs did not differ significantly one from each other. Standard deviations up to 1.24% were found. Error B: After reconstruction of the volunteers' BrainPET data with the CT-based attenuation maps without and with skull anomalies, a VOI-atlas analysis was performed revealing very little influence of the skull lesions (less than 3%), while the filled nasal

  16. Errors in MR-based attenuation correction for brain imaging with PET/MR scanners

    Energy Technology Data Exchange (ETDEWEB)

    Rota Kops, Elena, E-mail: e.rota.kops@fz-juelich.de [Forschungszentrum Juelich, INM4, Juelich (Germany); Herzog, Hans [Forschungszentrum Juelich, INM4, Juelich (Germany)

    2013-02-21

    Aim: Attenuation correction of PET data acquired by hybrid MR/PET scanners remains a challenge, even if several methods for brain and whole-body measurements have been developed recently. A template-based attenuation correction for brain imaging proposed by our group is easy to handle and delivers reliable attenuation maps in a short time. However, some potential error sources are analyzed in this study. We investigated the choice of template reference head among all the available data (error A), and possible skull anomalies of the specific patient, such as discontinuities due to surgery (error B). Materials and methods: An anatomical MR measurement and a 2-bed-position transmission scan covering the whole head and neck region were performed in eight normal subjects (4 females, 4 males). Error A: Taking alternatively one of the eight heads as reference, eight different templates were created by nonlinearly registering the images to the reference and calculating the average. Eight patients (4 females, 4 males; 4 with brain lesions, 4 w/o brain lesions) were measured in the Siemens BrainPET/MR scanner. The eight templates were used to generate the patients' attenuation maps required for reconstruction. ROI and VOI atlas-based comparisons were performed employing all the reconstructed images. Error B: CT-based attenuation maps of two volunteers were manipulated by manually inserting several skull lesions and filling a nasal cavity. The corresponding attenuation coefficients were substituted with the water's coefficient (0.096/cm). Results: Error A: The mean SUVs over the eight templates pairs for all eight patients and all VOIs did not differ significantly one from each other. Standard deviations up to 1.24% were found. Error B: After reconstruction of the volunteers' BrainPET data with the CT-based attenuation maps without and with skull anomalies, a VOI-atlas analysis was performed revealing very little influence of the skull lesions (less than 3

  17. 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.)

  18. Comparative evaluation of two commercial PET scanners, ECAT EXACT HR+ and Biograph 2, using GATE

    International Nuclear Information System (INIS)

    Karakatsanis, N.; Sakellios, N.; Tsantilas, N.X.; Dikaios, N.; Tsoumpas, C.; Lazaro, D.; Loudos, G.; Schmidtlein, C.R.; Louizi, K.; Valais, J.; Nikolopoulos, D.; Malamitsi, J.; Kandarakis, J.; Nikita, K.

    2006-01-01

    Geant4 application for tomographic emission (GATE) is a generic Monte Carlo simulation platform based on a general-purpose code GEANT4 and designed to simulate positron emission tomography (PET) and single photon emission tomography systems. Monte Carlo simulations are used in nuclear medicine to model imaging systems and develop and assess tomographic reconstruction algorithms and correction methods for improved image quantification. The purpose of this study is to validate two GATE models of the commercial available PET scanner HR+ and the PET/CT Biograph 2. The geometry of the system components has been described in GATE, including detector ring, crystal blocks, PMTs etc. The energy and spatial resolution of the scanners as given by the manufacturers have been taken into account. The GATE simulated results are compared directly to experimental data obtained using a number of NEMA NU-2-2001 performance protocols, including spatial resolution, sensitivity and scatter fraction. All the respective phantoms are precisely modeled. Furthermore, an approximate dead-time model both at the level of single and coincidence events was developed so that the simulated count rate curve can satisfactorily match the experimental count rate performance curve for each scanner In addition a software tool was developed to build the sinograms from the simulated data and import them into the software for tomographic image reconstruction where the reconstruction algorithm of FBP3DRP was applied. An agreement of less than 0.8 mm was obtained between the spatial resolution of the simulated system and the experimental results. Also the simulated scatter fraction for the NEMA NU 2-2001 scatter phantom matched the experimental results to within 3% of measured values. Finally the ratio of the simulated sensitivities with sources radially offset 0 and 10 cm from the central axis of each of the two scanners reaches an agreement of less than 1% between the simulated and experimental values. This

  19. Childhood Attachment to Pets: Associations between Pet Attachment, Attitudes to Animals, Compassion, and Humane Behaviour.

    Science.gov (United States)

    Hawkins, Roxanne D; Williams, Joanne M; Scottish Society For The Prevention Of Cruelty To Animals Scottish Spca

    2017-05-06

    Attachment to pets has an important role in children's social, emotional, and cognitive development, mental health, well-being, and quality of life. This study examined associations between childhood attachment to pets and caring and friendship behaviour, compassion, and attitudes towards animals. This study also examined socio-demographic differences, particularly pet ownership and pet type. A self-report survey of over one thousand 7 to 12 year-olds in Scotland, UK, revealed that the majority of children are strongly attached to their pets, but attachment scores differ depending on pet type and child gender. Analysis revealed that attachment to pets is facilitated by compassion and caring and pet-directed friendship behaviours and that attachment to pets significantly predicts positive attitudes towards animals. The findings have implications for the promotion of prosocial and humane behaviour. Encouraging children to participate in pet care behaviour may promote attachment between children and their pet, which in turn may have a range of positive outcomes for both children (such as reduced aggression, better well-being, and quality of life) and pets (such as humane treatment). This study enhances our understanding of childhood pet attachment and has implications for humane education and promoting secure emotional attachments in childhood.

  20. Childhood Attachment to Pets: Associations between Pet Attachment, Attitudes to Animals, Compassion, and Humane Behaviour

    Directory of Open Access Journals (Sweden)

    Roxanne D. Hawkins

    2017-05-01

    Full Text Available Attachment to pets has an important role in children’s social, emotional, and cognitive development, mental health, well-being, and quality of life. This study examined associations between childhood attachment to pets and caring and friendship behaviour, compassion, and attitudes towards animals. This study also examined socio-demographic differences, particularly pet ownership and pet type. A self-report survey of over one thousand 7 to 12 year-olds in Scotland, UK, revealed that the majority of children are strongly attached to their pets, but attachment scores differ depending on pet type and child gender. Analysis revealed that attachment to pets is facilitated by compassion and caring and pet-directed friendship behaviours and that attachment to pets significantly predicts positive attitudes towards animals. The findings have implications for the promotion of prosocial and humane behaviour. Encouraging children to participate in pet care behaviour may promote attachment between children and their pet, which in turn may have a range of positive outcomes for both children (such as reduced aggression, better well-being, and quality of life and pets (such as humane treatment. This study enhances our understanding of childhood pet attachment and has implications for humane education and promoting secure emotional attachments in childhood.

  1. Childhood Attachment to Pets: Associations between Pet Attachment, Attitudes to Animals, Compassion, and Humane Behaviour

    Science.gov (United States)

    Hawkins, Roxanne D.; Williams, Joanne M.

    2017-01-01

    Attachment to pets has an important role in children’s social, emotional, and cognitive development, mental health, well-being, and quality of life. This study examined associations between childhood attachment to pets and caring and friendship behaviour, compassion, and attitudes towards animals. This study also examined socio-demographic differences, particularly pet ownership and pet type. A self-report survey of over one thousand 7 to 12 year-olds in Scotland, UK, revealed that the majority of children are strongly attached to their pets, but attachment scores differ depending on pet type and child gender. Analysis revealed that attachment to pets is facilitated by compassion and caring and pet-directed friendship behaviours and that attachment to pets significantly predicts positive attitudes towards animals. The findings have implications for the promotion of prosocial and humane behaviour. Encouraging children to participate in pet care behaviour may promote attachment between children and their pet, which in turn may have a range of positive outcomes for both children (such as reduced aggression, better well-being, and quality of life) and pets (such as humane treatment). This study enhances our understanding of childhood pet attachment and has implications for humane education and promoting secure emotional attachments in childhood. PMID:28481256

  2. Clinical evaluation of 2D versus 3D whole-body PET image quality using a dedicated BGO PET scanner

    International Nuclear Information System (INIS)

    Visvikis, D.; Griffiths, D.; Costa, D.C.; Bomanji, J.; Ell, P.J.

    2005-01-01

    Three-dimensional positron emission tomography (3D PET) results in higher system sensitivity, with an associated increase in the detection of scatter and random coincidences. The objective of this work was to compare, from a clinical perspective, 3D and two-dimensional (2D) acquisitions in terms of whole-body (WB) PET image quality with a dedicated BGO PET system. 2D and 3D WB emission acquisitions were carried out in 70 patients. Variable acquisition parameters in terms of time of emission acquisition per axial field of view (aFOV) and slice overlap between sequential aFOVs were used during the 3D acquisitions. 3D and 2D images were reconstructed using FORE+WLS and OSEM respectively. Scatter correction was performed by convolution subtraction and a model-based scatter correction in 2D and 3D respectively. All WB images were attenuation corrected using segmented transmission scans. Images were blindly assessed by three observers for the presence of artefacts, confidence in lesion detection and overall image quality using a scoring system. Statistically significant differences between 2D and 3D image quality were only obtained for 3D emission acquisitions of 3 min. No statistically significant differences were observed for image artefacts or lesion detectability scores. Image quality correlated significantly with patient weight for both modes of operation. Finally, no differences were seen in image artefact scores for the different axial slice overlaps considered, suggesting the use of five slice overlaps in 3D WB acquisitions. 3D WB imaging using a dedicated BGO-based PET scanner offers similar image quality to that obtained in 2D considering similar overall times of acquisitions. (orig.)

  3. Legal protection of pet animals in domestic legislation

    Directory of Open Access Journals (Sweden)

    Vidić-Trninić Jelena

    2012-01-01

    Full Text Available The subject of the author's analysis is the issue of legal protection of pet animals. Through analysis of applicable provisions contained in the Act on Animal Welfare of Serbia, on one hand, and the fundamental principles and provisions set out in the European Convention for the Protection of Pet animals, on the other hand, this paper attempts to point out the degree of legal protection that pet animals are awarded under domestic legal regulations, as well as to answer the question of compatibility of the national legislation with the international standards set out in the mentioned European Convention regarding the above mentioned question. In addition, since the legal protection of pet animals is also regulated by relevant by-laws in our law, the analysis of certain aspects of protection provided to pet animals, specifically the Decision of the city of Novi Sad on keeping of domesticated animals, the paper attempts to draw attention to compliance of the solutions adopted in this legal act, with the fundamental principles of protection, provided to pets by laws or the Act on Animal Welfare of Serbia. Finally, in order to provide a more comprehensive insight in terms of achievement of the legal protection of pets in Serbian law, the paper analyzes the types of unlawful conduct of the owner or the holder of the animals, as well as their respective sanctioning prescribed in specific laws or bylaws.

  4. A fully automated and scalable timing probe-based method for time alignment of the LabPET II scanners

    Science.gov (United States)

    Samson, Arnaud; Thibaudeau, Christian; Bouchard, Jonathan; Gaudin, Émilie; Paulin, Caroline; Lecomte, Roger; Fontaine, Réjean

    2018-05-01

    A fully automated time alignment method based on a positron timing probe was developed to correct the channel-to-channel coincidence time dispersion of the LabPET II avalanche photodiode-based positron emission tomography (PET) scanners. The timing probe was designed to directly detect positrons and generate an absolute time reference. The probe-to-channel coincidences are recorded and processed using firmware embedded in the scanner hardware to compute the time differences between detector channels. The time corrections are then applied in real-time to each event in every channel during PET data acquisition to align all coincidence time spectra, thus enhancing the scanner time resolution. When applied to the mouse version of the LabPET II scanner, the calibration of 6 144 channels was performed in less than 15 min and showed a 47% improvement on the overall time resolution of the scanner, decreasing from 7 ns to 3.7 ns full width at half maximum (FWHM).

  5. A feasibility study of ortho-positronium decays measurement with the J-PET scanner based on plastic scintillators

    Science.gov (United States)

    Kamińska, D.; Gajos, A.; Czerwiński, E.; Alfs, D.; Bednarski, T.; Białas, P.; Curceanu, C.; Dulski, K.; Głowacz, B.; Gupta-Sharma, N.; Gorgol, M.; Hiesmayr, B. C.; Jasińska, B.; Korcyl, G.; Kowalski, P.; Krzemień, W.; Krawczyk, N.; Kubicz, E.; Mohammed, M.; Niedźwiecki, Sz.; Pawlik-Niedźwiecka, M.; Raczyński, L.; Rudy, Z.; Silarski, M.; Wieczorek, A.; Wiślicki, W.; Zgardzińska, B.; Zieliński, M.; Moskal, P.

    2016-08-01

    We present a study of the application of the Jagiellonian positron emission tomograph (J-PET) for the registration of gamma quanta from decays of ortho-positronium (o-Ps). The J-PET is the first positron emission tomography scanner based on organic scintillators in contrast to all current PET scanners based on inorganic crystals. Monte Carlo simulations show that the J-PET as an axially symmetric and high acceptance scanner can be used as a multi-purpose detector well suited to pursue research including e.g. tests of discrete symmetries in decays of ortho-positronium in addition to the medical imaging. The gamma quanta originating from o-Ps decay interact in the plastic scintillators predominantly via the Compton effect, making the direct measurement of their energy impossible. Nevertheless, it is shown in this paper that the J-PET scanner will enable studies of the { o-Ps }→ 3γ decays with angular and energy resolution equal to σ (θ ) ≈ {0.4°} and σ (E) ≈ 4.1 {keV}, respectively. An order of magnitude shorter decay time of signals from plastic scintillators with respect to the inorganic crystals results not only in better timing properties crucial for the reduction of physical and instrumental background, but also suppresses significantly the pile-ups, thus enabling compensation of the lower efficiency of the plastic scintillators by performing measurements with higher positron source activities.

  6. A feasibility study of ortho-positronium decays measurement with the J-PET scanner based on plastic scintillators

    International Nuclear Information System (INIS)

    Kaminska, D.; Gajos, A.; Czerwinski, E.; Alfs, D.; Bednarski, T.; Bialas, P.; Dulski, K.; Glowacz, B.; Gupta-Sharma, N.; Korcyl, G.; Krawczyk, N.; Kubicz, E.; Mohammed, M.; Niedzwiecki, Sz.; Pawlik-Niedzwiecka, M.; Rudy, Z.; Wieczorek, A.; Zielinski, M.; Moskal, P.; Curceanu, C.; Silarski, M.; Gorgol, M.; Jasinska, B.; Zgardzinska, B.; Hiesmayr, B.C.; Kowalski, P.; Raczynski, L.; Wislicki, W.; Krzemien, W.

    2016-01-01

    We present a study of the application of the Jagiellonian positron emission tomograph (J-PET) for the registration of gamma quanta from decays of ortho-positronium (o-Ps). The J-PET is the first positron emission tomography scanner based on organic scintillators in contrast to all current PET scanners based on inorganic crystals. Monte Carlo simulations show that the J-PET as an axially symmetric and high acceptance scanner can be used as a multi-purpose detector well suited to pursue research including e.g. tests of discrete symmetries in decays of ortho-positronium in addition to the medical imaging. The gamma quanta originating from o-Ps decay interact in the plastic scintillators predominantly via the Compton effect, making the direct measurement of their energy impossible. Nevertheless, it is shown in this paper that the J-PET scanner will enable studies of the o-Ps → 3γ decays with angular and energy resolution equal to σ(θ) ∼ 0.4 circle and σ(E) ∼ 4.1 keV, respectively. An order of magnitude shorter decay time of signals from plastic scintillators with respect to the inorganic crystals results not only in better timing properties crucial for the reduction of physical and instrumental background, but also suppresses significantly the pile-ups, thus enabling compensation of the lower efficiency of the plastic scintillators by performing measurements with higher positron source activities. (orig.)

  7. Qualification of PET scanners for use in multicenter cancer clinical trials: the American College of Radiology Imaging Network experience.

    Science.gov (United States)

    Scheuermann, Joshua S; Saffer, Janet R; Karp, Joel S; Levering, Anthony M; Siegel, Barry A

    2009-07-01

    The PET Core Laboratory of the American College of Radiology Imaging Network (ACRIN) qualifies sites to participate in multicenter research trials by quantitatively reviewing submitted PET scans of uniform cylinders to verify the accuracy of scanner standardized uptake value (SUV) calibration and qualitatively reviewing clinical PET images from each site. To date, cylinder and patient data from 169 PET scanners have been reviewed, and 146 have been qualified. Each site is required to submit data from 1 uniform cylinder and 2 patient test cases. Submitted phantom data are analyzed by drawing a circular region of interest that encompasses approximately 90% of the diameter of the interior of the phantom and then recording the mean SUV and SD of each transverse slice. In addition, average SUVs are measured in the liver of submitted patient scans. These data illustrate variations of SUVs across PET scanners and across institutions, and comparison of results with values submitted by the site indicate the level of experience of PET camera operators in calculating SUVs. Of 101 scanner applications for which detailed records of the qualification process were available, 12 (12%) failed because of incorrect SUV or normalization calibrations. For sites to pass, the average cylinder SUV is required to be 1.0 +/- 0.1. The average SUVs for uniform cylinder images for the most common scanners evaluated-Siemens Biograph PET/CT (n = 43), GE Discovery LS PET/CT (n = 15), GE Discovery ST PET/CT (n = 34), Philips Allegro PET (n = 5), and Philips Gemini PET/CT (n = 11)-were 0.99, 1.01, 1.00, 0.98, and 0.95, respectively, and the average liver SUVs for submitted test cases were 2.34, 2.13, 2.27, 1.73, and 1.92, respectively. Minimizing errors in SUV measurement is critical to achieving accurate quantification in clinical trials. The experience of the ACRIN PET Core Laboratory shows that many sites are unable to maintain accurate SUV calibrations without additional training or supervision

  8. Energy spectra analysis of the four-layer DOI detector for the brain PET scanner: jPET-D4

    Science.gov (United States)

    Yoshida, Eiji; Kitamura, Keishi; Tsuda, Tomoaki; Shibuya, Kengo; Yamaya, Taiga; Inadama, Naoko; Hasegawa, Tomoyuki; Murayama, Hideo

    2006-02-01

    A depth of interaction (DOI) detector is being developed for the brain PET scanner, jPET-D4. We introduce a light output correction procedure to compensate for variations among the crystal elements in the DOI detector. Under uniform irradiation with 511 keV gamma rays, we estimate the light output of each crystal element by identifying each crystal element, and generate a look-up table (LUT) for light output correction. We evaluate the energy resolution of all crystal elements. The energy resolution of 16% is achieved after light output correction for all crystal elements. The DOI detector can correct light output variations that are related to the DOI. We analyze the crystal position dependence of the energy spectra due to inter-crystal scattering among the multiple crystal elements in the DOI detector. It is highly possible that gamma rays interacting with central crystal elements in the crystal array are absorbed by surrounding crystal elements and the Compton part of the energy spectrum is decreased. Inter-crystal scattering has less impact on the energy resolution of the DOI detector.

  9. Image quality assessment of LaBr3-based whole-body 3D PET scanners: a Monte Carlo evaluation

    International Nuclear Information System (INIS)

    Surti, S; Karp, J S; Muehllehner, G

    2004-01-01

    The main thrust for this work is the investigation and design of a whole-body PET scanner based on new lanthanum bromide scintillators. We use Monte Carlo simulations to generate data for a 3D PET scanner based on LaBr 3 detectors, and to assess the count-rate capability and the reconstructed image quality of phantoms with hot and cold spheres using contrast and noise parameters. Previously we have shown that LaBr 3 has very high light output, excellent energy resolution and fast timing properties which can lead to the design of a time-of-flight (TOF) whole-body PET camera. The data presented here illustrate the performance of LaBr 3 without the additional benefit of TOF information, although our intention is to develop a scanner with TOF measurement capability. The only drawbacks of LaBr 3 are the lower stopping power and photo-fraction which affect both sensitivity and spatial resolution. However, in 3D PET imaging where energy resolution is very important for reducing scattered coincidences in the reconstructed image, the image quality attained in a non-TOF LaBr 3 scanner can potentially equal or surpass that achieved with other high sensitivity scanners. Our results show that there is a gain in NEC arising from the reduced scatter and random fractions in a LaBr 3 scanner. The reconstructed image resolution is slightly worse than a high-Z scintillator, but at increased count-rates, reduced pulse pileup leads to an image resolution similar to that of LSO. Image quality simulations predict reduced contrast for small hot spheres compared to an LSO scanner, but improved noise characteristics at similar clinical activity levels

  10. Performance of a PET Insert for High-Resolution Small-Animal PET/MRI at 7 Tesla.

    Science.gov (United States)

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

    2018-03-01

    We characterize a compact MR-compatible PET insert for simultaneous preclinical PET/MRI. Although specifically designed with the strict size constraint to fit inside the 114-mm inner diameter of the BGA-12S gradient coil used in the BioSpec 70/20 and 94/20 series of small-animal MRI systems, the insert can easily be installed in any appropriate MRI scanner or used as a stand-alone PET system. Methods: The insert consists of 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 arrays. Scintillator crystal arrays are made from 22 × 10 and 21 × 9 crystals in the bottom and top layers, respectively, with respective layer thicknesses of 6 and 4 mm, arranged with a 1.27-mm pitch, resulting in a useable field of view 28 mm long and about 55 mm wide. Results: Spatial resolution ranged from 1.17 to 1.86 mm full width at half maximum in the radial direction from a radial offset of 0-15 mm. With a 300- to 800-keV energy window, peak sensitivity was 2.2% and noise-equivalent count rate from a mouse-sized phantom at 3.7 MBq was 11.1 kcps and peaked at 20.8 kcps at 14.5 MBq. Phantom imaging showed that features as small as 0.7 mm could be resolved. 18 F-FDG PET/MR images of mouse and rat brains showed no signs of intermodality interference and could excellently resolve substructures within the brain. Conclusion: Because of excellent spatial resolvability and lack of intermodality interference, this PET insert will serve as a useful tool for preclinical PET/MR. © 2018 by the Society of Nuclear Medicine and Molecular Imaging.

  11. A Movable Phantom Design for Quantitative Evaluation of Motion Correction Studies on High Resolution PET Scanners

    DEFF Research Database (Denmark)

    Olesen, Oline Vinter; Svarer, C.; Sibomana, M.

    2010-01-01

    , movable, mechanical PET phantom to simulate patients' head movements while being scanned. This can be used for evaluating motion correction methods. A low-cost phantom controlled by a rotary stage motor was built and tested for axial rotations of 1 degrees - 10 degrees with the multiple acquisition frame...... method. The phantom is able to perform stepwise and continuous axial rotations with submillimeter accuracy, and the movements are repeatable. The scans were acquired on the high resolution research tomograph dedicated brain scanner. The scans were reconstructed with the new 3-D ordered subset expectation...... maximization algorithm with modeling of the point spread function (3DOSEM-PSF), and they were corrected for motions based on external tracking information using the Polaris Vicra real-time stereo motion-tracking system. The new automatic, movable phantom has a robust design and is a potential quality...

  12. Attenuation correction for the HRRT PET-scanner using transmission scatter correction and total variation regularization

    DEFF Research Database (Denmark)

    Keller, Sune H; Svarer, Claus; Sibomana, Merence

    2013-01-01

    In the standard software for the Siemens high-resolution research tomograph (HRRT) positron emission tomography (PET) scanner the most commonly used segmentation in the μ -map reconstruction for human brain scans is maximum a posteriori for transmission (MAP-TR). Bias in the lower cerebellum...... and pons in HRRT brain images have been reported. The two main sources of the problem with MAP-TR are poor bone/soft tissue segmentation below the brain and overestimation of bone mass in the skull. Method: We developed the new transmission processing with total variation (TXTV) method that introduces...... scatter correction in the μ-map reconstruction and total variation filtering to the transmission processing. Results: Comparing MAP-TR and the new TXTV with gold standard CT-based attenuation correction, we found that TXTV has less bias as compared to MAP-TR. We also compared images acquired at the HRRT...

  13. Preliminary experience of a three-dimensional, large-field-of-view PET scanner for the localization of partial epilepsy

    International Nuclear Information System (INIS)

    Binns, D.S.; O'Brien, T.J.; Murphy, M.; Cook, M.J.; Hicks, R.J.

    1999-01-01

    Full text: PET scanning is a useful ancillary technique in the localization of intractable partial epilepsy, but its widespread use has been limited by the high cost of traditional PET equipment and radioisotopes. The use of 3D-scanning mode with a large-field of-view PET scanner involves lower equipment costs and requires significantly lower doses of radioisotope. Our aim was to report our preliminary experience of the use of a 3-D, large-field-of-view scanner for FDG-PET studies in the localization of partial epilepsy. 31 patients (pts) with partial epilepsy were studied. The FDG-PET scans were reviewed blindly by a single reviewer without knowledge of seizure localization on structural imaging or ictal electroencephalographic (EEG) monitoring. The PET results were correlated with the localization by more traditional techniques and the results on surgery when available. A localized region of hypometabolism on FDG-PET scanning was reported in 26/31 (84%) patients (21 temporal, 5 extratemporal). This compared favourably with volumetric MRI on which 19/31 (61%) had a focal potentially epileptogenic abnormality, all of which were concordant with the PET localization. PET was concordant with ictal EEG onset in all 22 patients with localizing studies, including 5 pts with normal MRI. PET demonstrated localized hypometabolism in 4/5 pts with non-localizing ictal EEG and was concordant in both pts with abnormal MRI in this group. PET was considered normal in 4 pts, including 3 pts with normal MRI but localizing EEG and 1 pt without EEG or MRI abnormality. One pt with a localizing EEG and normal MRI was felt to have bitemporal hypometabolism. Five patients have subsequently had resective epilepsy surgery with 4 currently seizure-free and 1 significantly improved. Four patients are planned for surgery in the near future. In conclusion, FDG-PET using a 3-D, large-field-of view PET scanner provides sensitive and specific localization in partial epilepsy, and may provide a

  14. Real-time 3D motion tracking for small animal brain PET

    Science.gov (United States)

    Kyme, A. Z.; Zhou, V. W.; Meikle, S. R.; Fulton, R. R.

    2008-05-01

    High-resolution positron emission tomography (PET) imaging of conscious, unrestrained laboratory animals presents many challenges. Some form of motion correction will normally be necessary to avoid motion artefacts in the reconstruction. The aim of the current work was to develop and evaluate a motion tracking system potentially suitable for use in small animal PET. This system is based on the commercially available stereo-optical MicronTracker S60 which we have integrated with a Siemens Focus-220 microPET scanner. We present measured performance limits of the tracker and the technical details of our implementation, including calibration and synchronization of the system. A phantom study demonstrating motion tracking and correction was also performed. The system can be calibrated with sub-millimetre accuracy, and small lightweight markers can be constructed to provide accurate 3D motion data. A marked reduction in motion artefacts was demonstrated in the phantom study. The techniques and results described here represent a step towards a practical method for rigid-body motion correction in small animal PET. There is scope to achieve further improvements in the accuracy of synchronization and pose measurements in future work.

  15. Molecular imaging of small animals with dedicated PET tomographs

    International Nuclear Information System (INIS)

    Chatziioannou, A.F.

    2002-01-01

    Biological discovery has moved at an accelerated pace in recent years, with a considerable focus on the transition from in vitro to in vivo models. As a result, there has been a significant increase in the need to adapt clinical imaging methods, as well as for novel imaging technologies for biological research. Positron emission tomography (PET) is a clinical imaging modality that permits the use of positron-labeled molecular imaging probes for non-invasive assays of biochemical processes. The imaging procedure can be repeatedly performed before and after interventions, thereby allowing each animal to be used as its own control. Positron-labeled compounds that target a range of molecular targets have been and continue to be synthesized, with examples of biological processes ranging from receptors and synthesis of transmitters in cell communication, to metabolic processes and gene expression. In animal research, PET has been used extensively in the past for studies of non-human primates and other larger animals. New detector technology has improved spatial resolution, and has made possible PET scanning for the study of the most important modern molecular biology model, the laboratory mouse. This paper presents the challenges facing PET technology as applied to small animal imaging, provides a historical overview of the development of small animal PET systems, and discusses the current state of the art in small animal PET technology. (orig.)

  16. MRI compatible small animal monitoring and trigger system for whole body scanners

    Energy Technology Data Exchange (ETDEWEB)

    Herrmann, Karl-Heinz; Krumbein, Ines; Reichenbach, Juergen R. [Jena University Hospital (Germany). Medical Physics Group; Pfeiffer, Norman [Jena University Hospital (Germany). Medical Physics Group; Ernst-Abbe-Fachhochschule Jena (Germany); Herrmann, Lutz [Ernst-Abbe-Fachhochschule Jena (Germany)

    2014-03-01

    Performing magnetic resonance imaging (MRI) experiments with small animals requires continuous monitoring of vital parameters, especially the respiration rate. Clinical whole-body MR scanners represent an attractive option for preclinical imaging as dedicated animal scanners are cost-intensive in both investment and maintenance, thus limiting their availability. Even though impressive image quality is achievable with clinical MR systems in combination with special coils, their built-in physiologic monitoring and triggering units are often not suited for small animal imaging. In this work, we present a simple, MRI compatible low cost solution to monitor the respiration and heart rate of small animals in a clinical whole-body MR scanner. The recording and processing of the biosignals as well as the optimisation of the respiratory trigger generation is described. Additionally rat and mouse in-vivo MRI experiments are presented to illustrate the effectiveness of the monitoring and respiratory trigger system in suppressing motion artifacts. (orig.)

  17. [Species specific animal housing in pet shops (catalogue of measures)].

    Science.gov (United States)

    Rinno, J

    1996-02-01

    Many veterinarians lack the essential zoological and ethologic knowledge of toy fishes and birds, reptiles, and the amphibians to correctly judge the specific keeping of animals in pet shops. To make up such deficits, the study group "AK 8 Zoofachhandel" (= study group 8 pet shops) of "Tierärztliche Vereinigung für Tierschutz TVT" (= Veterinarian Consortium for the Protection of Animals) has been setting up lists, which contain criteria that enables veterinarians to judge the conditions of animal keeping in pet shops equally. Any kind of defect determined in an inspection of a pet shop will consequentially lead to the specific measures for each individual case. These measures have to be made out by the veterinarian in accordance with those lists and his individual knowledge. The following slides are examplary for good as well as bad keeping conditions.

  18. Use of scanner characteristics in iterative image reconstruction for high-resolution positron emission tomography studies of small animals

    International Nuclear Information System (INIS)

    Brix, G.; Doll, J.; Bellemann, M.E.; Trojan, H.; Haberkorn, U.; Schmidlin, P.; Ostertag, H.

    1997-01-01

    The purpose of this work was to improve of the spatial resolution of a whole-body PET system for experimental studies of small animals by incorporation of scanner characteristics into the process of iterative image reconstruction. The image-forming characteristics of the PET camera were characterized by a spatially variant line-spread function (LSF), which was determined from 49 activated copper-64 line sources positioned over a field of view (FOV) of 21.0 cm. During the course of iterative image reconstruction, the forward projection of the estimated image was blurred with the LSF at each iteration step before the estimated projections were compared with the measured projections. Moreover, imaging studies of a rat and two nude mice were performed to evaluate the imaging properties of our approach in vivo. The spatial resolution of the scanner perpendicular to the direction of projection could be approximated by a one-dimensional Gaussian-shaped LSF with a full-width at half-maximum increasing from 6.5 mm at the centre to 6.7 mm at a radial distance of 10.5 cm. The incorporation of this blurring kernel into the iteration formula resulted in a significantly improved spatial resolution of about 3.9 mm over the examined FOV. As demonstrated by the phantom and the animal experiments, the high-resolution algorithm not only led to a better contrast resolution in the reconstructed emission scans but also improved the accuracy for quantitating activity concentrations in small tissue structures without leading to an amplification of image noise or image mottle. The presented data-handling strategy incorporates the image restoration step directly into the process of algebraic image reconstruction and obviates the need for ill-conditioned ''deconvolution'' procedures to be performed on the projections or on the reconstructed image. In our experience, the proposed algorithm is of special interest in experimental studies of small animals. (orig./AJ). With 9 figs

  19. Use of scanner characteristics in iterative image reconstruction for high-resolution positron emission tomography studies of small animals

    Energy Technology Data Exchange (ETDEWEB)

    Brix, G. [Research Program ``Radiological Diagnostics and Therapy``, German Cancer Research Center (DKFZ), Heidelberg (Germany); Doll, J. [Research Program ``Radiological Diagnostics and Therapy``, German Cancer Research Center (DKFZ), Heidelberg (Germany); Bellemann, M.E. [Research Program ``Radiological Diagnostics and Therapy``, German Cancer Research Center (DKFZ), Heidelberg (Germany); Trojan, H. [Research Program ``Radiological Diagnostics and Therapy``, German Cancer Research Center (DKFZ), Heidelberg (Germany); Haberkorn, U. [Research Program ``Radiological Diagnostics and Therapy``, German Cancer Research Center (DKFZ), Heidelberg (Germany); Schmidlin, P. [Research Program ``Radiological Diagnostics and Therapy``, German Cancer Research Center (DKFZ), Heidelberg (Germany); Ostertag, H. [Research Program ``Radiological Diagnostics and Therapy``, German Cancer Research Center (DKFZ), Heidelberg (Germany)

    1997-07-01

    The purpose of this work was to improve of the spatial resolution of a whole-body PET system for experimental studies of small animals by incorporation of scanner characteristics into the process of iterative image reconstruction. The image-forming characteristics of the PET camera were characterized by a spatially variant line-spread function (LSF), which was determined from 49 activated copper-64 line sources positioned over a field of view (FOV) of 21.0 cm. During the course of iterative image reconstruction, the forward projection of the estimated image was blurred with the LSF at each iteration step before the estimated projections were compared with the measured projections. Moreover, imaging studies of a rat and two nude mice were performed to evaluate the imaging properties of our approach in vivo. The spatial resolution of the scanner perpendicular to the direction of projection could be approximated by a one-dimensional Gaussian-shaped LSF with a full-width at half-maximum increasing from 6.5 mm at the centre to 6.7 mm at a radial distance of 10.5 cm. The incorporation of this blurring kernel into the iteration formula resulted in a significantly improved spatial resolution of about 3.9 mm over the examined FOV. As demonstrated by the phantom and the animal experiments, the high-resolution algorithm not only led to a better contrast resolution in the reconstructed emission scans but also improved the accuracy for quantitating activity concentrations in small tissue structures without leading to an amplification of image noise or image mottle. The presented data-handling strategy incorporates the image restoration step directly into the process of algebraic image reconstruction and obviates the need for ill-conditioned ``deconvolution`` procedures to be performed on the projections or on the reconstructed image. In our experience, the proposed algorithm is of special interest in experimental studies of small animals. (orig./AJ). With 9 figs.

  20. Depth of interaction (DOI) determination in three-layer small animal PET

    International Nuclear Information System (INIS)

    Kwon, Sun II; Hong, Seong Jong; Ito, Mikiko; Lee, Geon Song; Sim, Kwang Souk; Park, Kwang Suk; Rhee, June Tak; Lee, Jae Sung

    2007-01-01

    Improved spatial resolution without sacrificing sensitivity is one of the most challenging developmental goals for small animal PET scanners. The 3-layer configuration that we propose here utilizes relative offsets of half a crystal pitch in x, y directions, and pulse shape discrimination to obtain DOI. We present recent progress in developing the 3-layer PET scanner with LGSO crystals and H9500 PMTs. 3-layers of crystals (of each crystal 1.5x1.5x7.0 mm 3 ) were composed of a L 0.2 GSO crystal layer and a L 0.9 GSO crystal layer aligned with each other, and a L 0.9 GSO crystal layer offset at half a crystal pitch in x, y directions. The L 0.2 GSO crystal layer was attached to a Hamamatsu H9500. The devised small animal PET scanner has a diameter of 84 mm. We built a charge division circuit consisted of resistor matrix. Struck positions by photons were obtained with the 4 signals from the circuit. To study the layer identification capability of two crystal layers with a relative offset by half a crystal, we assembled two crystal layers with a 7x7 L 0.9 GSO crystal block and a 6x6 L 0.9 GSO crystal and obtained flood images at the center and the corner of the H9500 PMT. The crystal identification between the aligned L 0.2 GSO and L 0.9 GSO crystal layers was obtained using different pulse characteristics from these two crystals. The flood image of the 2-layer crystal blocks at the center and the corner of the H9500 PMT shows the clear separation of individual crystals and no distortion of image. The ratios of peaks to valleys of horizontal and vertical projection diagrams were about 5 ∼ 6(center) and 3 ∼ 4(corner). Energy resolutions were 14.4% (6x6 crystals) and 18.1% (7x7 crystals). We also achieved the crystal identification efficiencies of ∼99%. Based on these results, we are confident that a 3-layer animal PET scanner with high resolution and sensitivity can be built

  1. The emerging disease occurrence of pet animals in Bangladesh

    Directory of Open Access Journals (Sweden)

    Umma Habiba

    2016-12-01

    Results: Among the most general pet animals in Bangladesh (dog, cat, rabbit, the mostly occured diseases were scabies (23.07%, feline ascariasis (37.14% and rabbit mange (34.61%, while the less frequent diseases were canine parvovirus enteritis (2.19%, cat scratch disease (5.71% and overgrown teeth (7.69%. Conclusion: The study provides basic information about the current status and the percentage (% of disease occurrence considering the emerging diseases of pet animals in Bangladesh. [J Adv Vet Anim Res 2016; 3(4.000: 413-419

  2. Initial validation of 4D-model for a clinical PET scanner using the Monte Carlo code gate

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, Igor F.; Lima, Fernando R.A.; Gomes, Marcelo S., E-mail: falima@cnen.gov.b [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Vieira, Jose W.; Pacheco, Ludimila M. [Instituto Federal de Educacao, Ciencia e Tecnologia (IFPE), Recife, PE (Brazil); Chaves, Rosa M. [Instituto de Radium e Supervoltagem Ivo Roesler, Recife, PE (Brazil)

    2011-07-01

    Building exposure computational models (ECM) of emission tomography (PET and SPECT) currently has several dedicated computing tools based on Monte Carlo techniques (SimSET, SORTEO, SIMIND, GATE). This paper is divided into two steps: (1) using the dedicated code GATE (Geant4 Application for Tomographic Emission) to build a 4D model (where the fourth dimension is the time) of a clinical PET scanner from General Electric, GE ADVANCE, simulating the geometric and electronic structures suitable for this scanner, as well as some phenomena 4D, for example, rotating gantry; (2) the next step is to evaluate the performance of the model built here in the reproduction of test noise equivalent count rate (NEC) based on the NEMA Standards Publication NU protocols 2-2007 for this tomography. The results for steps (1) and (2) will be compared with experimental and theoretical values of the literature showing actual state of art of validation. (author)

  3. PET/MR in children. Initial clinical experience in paediatric oncology using an integrated PET/MR scanner

    OpenAIRE

    Hirsch, Franz Wolfgang; Sattler, Bernhard; Sorge, Ina; Kurch, Lars; Viehweger, Adrian; Ritter, Lutz; Werner, Peter; Jochimsen, Thies; Barthel, Henryk; Bierbach, Uta; Till, Holger; Sabri, Osama; Kluge, Regine

    2013-01-01

    Use of PET/MR in children has not previously been reported, to the best of our knowledge. Children with systemic malignancies may benefit from the reduced radiation exposure offered by PET/MR. We report our initial experience with PET/MR hybrid imaging and our current established sequence protocol after 21 PET/MR studies in 15 children with multifocal malignant diseases. The effective dose of a PET/MR scan was only about 20% that of the equivalent PET/CT examination. Simultaneous acquisition ...

  4. Studies oriented to optimize the image quality of the small animal PET: Clear PET, modifying some of the parameters of the reconstruction algorithm IMF-OSEM 3D on the data acquisition simulated with GAMOS

    International Nuclear Information System (INIS)

    Canadas, M.; Mendoza, J.; Embid, M.

    2007-01-01

    This report presents studies oriented to optimize the image quality of the small animal PET: Clear- PET. Certain figures of merit (FOM) were used to assess a quantitative value of the contrast and delectability of lesions. The optimization was carried out modifying some of the parameters in the reconstruction software of the scanner, imaging a mini-Derenzo phantom and a cylinder phantom with background activity and two hot spheres. Specifically, it was evaluated the incidence of the inter-update Metz filter (IMF) inside the iterative reconstruction algorithm 3D OSEM. The data acquisition was simulated using the GAMOS framework (Monte Carlo simulation). Integrating GAMOS output with the reconstruction software of the scanner was an additional novelty of this work, to achieve this, data sets were written with the list-mode format (LMF) of ClearPET. In order to verify the optimum values obtained, we foresee to make real acquisitions in the ClearPET of CIEMAT. (Author) 17 refs

  5. Performance of a new 3D-only PET scanner - the EXACT3D

    Energy Technology Data Exchange (ETDEWEB)

    Spinks, T.J.; Bailey, D.L.; Miller, M. [Hammersmith Hospital, London (United Kingdom)] [and others

    1996-12-31

    Characteristics of currently the highest sensitivity 3D-only PET scanner (CTI/Siemens 966/EXACT3D) have been studied. The device has 48 rings (82cm diameter) of BGO detector elements (4.0 x 4.1 x 30mm, 8 x 8 block) and an axial FOV of 23.4cm. Attenuation correction is carried out with a point source of {sup 137}Cs which moves under hydraulic pressure in a helical tube. Transaxial resolution is 4.7mm 1cm from the centre of the FOV increasing, in the radial direction to 6.3mm and 7.3mm at 10cm and 15cm. At a lower threshold of 350keV, the scatter fraction is 40%. With scatter subtracted, the efficiency (20cm cylinder) is 6.9 x 104 cps/kBq/ml (maximum ring difference of 40); the absolute sensitivity is 5.8%. In the current configuration, the maximum total coincidence event rate is limited to about 3 x 10{sup 6} per sec. The maximum trues rate is about 850kcps (90MBq in the FOV). List mode acquisition has been implemented to maximize temporal resolution and optimize data storage. The more open geometry of this device gives a broader singles FOV. Hence administered doses and/or additional side-shielding need to be carefully considered to optimize noise-equivalent counts.

  6. A count rate model for PET and its application to an LSO HR PLUS scanner

    International Nuclear Information System (INIS)

    Moisan, C.; Rogers, J.G.; Douglas, J.L.

    1996-10-01

    We present a count rate model for PET. Considering a standard 20 x 20 cm phantom in the field-of-view of a cylindrical septaless tomograph, the model computes the acceptance to prompt and random events from simple geometric considerations. Dead time factors at all stages of a typical event acquisition architecture are calculated from specified processing clock cycles. Validations of the model's predictions against the measured performances of the ECAT-953B and the EXACT HR PLUS are presented. The model is then used to investigate the benefit of using detectors made of LSO in the EXACT HR PLUS scanner geometry. The results indicate that in replacing BGO by the faster LSO, one can count on an increase of the peak noise-equivalent-count rate by a factor 2.2. This gain will be achieved by using a 5 nsec coincidence window, buckets operating on 128 nsec clock cycle, and front-end data acquisition that can sustain a total rate of 2.9 MHz. (authors)

  7. Test of a single module of the J-PET scanner based on plastic scintillators

    Science.gov (United States)

    Moskal, P.; Niedźwiecki, Sz.; Bednarski, T.; Czerwiński, E.; Kapłon, Ł.; Kubicz, E.; Moskal, I.; Pawlik-Niedźwiecka, M.; Sharma, N. G.; Silarski, M.; Zieliński, M.; Zoń, N.; Białas, P.; Gajos, A.; Kochanowski, A.; Korcyl, G.; Kowal, J.; Kowalski, P.; Kozik, T.; Krzemień, W.; Molenda, M.; Pałka, M.; Raczyński, L.; Rudy, Z.; Salabura, P.; Słomski, A.; Smyrski, J.; Strzelecki, A.; Wieczorek, A.; Wiślicki, W.

    2014-11-01

    A Time of Flight Positron Emission Tomography scanner based on plastic scintillators is being developed at the Jagiellonian University by the J-PET collaboration. The main challenge of the conducted research lies in the elaboration of a method allowing application of plastic scintillators for the detection of low energy gamma quanta. In this paper we report on tests of a single detection module built out from the BC-420 plastic scintillator strip (with dimensions of 5×19×300 mm3) read out at two ends by Hamamatsu R5320 photomultipliers. The measurements were performed using collimated beam of annihilation quanta from the 68Ge isotope and applying the Serial Data Analyzer (Lecroy SDA6000A) which enabled sampling of signals with 50 ps intervals. The time resolution of the prototype module was established to be better than 80 ps (σ) for a single level discrimination. The spatial resolution of the determination of the hit position along the strip was determined to be about 0.93 cm (σ) for the annihilation quanta. The fractional energy resolution for the energy E deposited by the annihilation quanta via the Compton scattering amounts to σ(E) / E ≈ 0.044 /√{ E(MeV) } and corresponds to the σ(E) / E of 7.5% at the Compton edge.

  8. Performance of a new 3D-only PET scanner - the EXACT3D

    International Nuclear Information System (INIS)

    Spinks, T.J.; Bailey, D.L.; Miller, M.

    1996-01-01

    Characteristics of currently the highest sensitivity 3D-only PET scanner (CTI/Siemens 966/EXACT3D) have been studied. The device has 48 rings (82cm diameter) of BGO detector elements (4.0 x 4.1 x 30mm, 8 x 8 block) and an axial FOV of 23.4cm. Attenuation correction is carried out with a point source of 137 Cs which moves under hydraulic pressure in a helical tube. Transaxial resolution is 4.7mm 1cm from the centre of the FOV increasing, in the radial direction to 6.3mm and 7.3mm at 10cm and 15cm. At a lower threshold of 350keV, the scatter fraction is 40%. With scatter subtracted, the efficiency (20cm cylinder) is 6.9 x 104 cps/kBq/ml (maximum ring difference of 40); the absolute sensitivity is 5.8%. In the current configuration, the maximum total coincidence event rate is limited to about 3 x 10 6 per sec. The maximum trues rate is about 850kcps (90MBq in the FOV). List mode acquisition has been implemented to maximize temporal resolution and optimize data storage. The more open geometry of this device gives a broader singles FOV. Hence administered doses and/or additional side-shielding need to be carefully considered to optimize noise-equivalent counts

  9. 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

  10. The significant human-animal bond: Pets with cancer

    Energy Technology Data Exchange (ETDEWEB)

    Weller, R.E.

    1994-03-01

    Veterinarians have responsibilities to both the animal and its owner. In the past several years there has been an increased awareness and concern about human-animal bonds. As a result, we have begun to appreciate the nature, strength, and significance of bonds that develop between humans and companion animals. It is typical for a pet to be perceived as and treated as a member of the family and as a result, animals provide special and beneficial relationships for many years. It is partly because of this role of the pet in promoting human health and happiness that we as veterinarians have an obligation to assist both owner and animal. The mark of the good practitioner concerns not only the ability to diagnose and treat accurately, but also the ability to show understanding and compassionate judgement.

  11. Scatter characterization and correction for simultaneous multiple small-animal PET imaging.

    Science.gov (United States)

    Prasad, Rameshwar; Zaidi, Habib

    2014-04-01

    The rapid growth and usage of small-animal positron emission tomography (PET) in molecular imaging research has led to increased demand on PET scanner's time. One potential solution to increase throughput is to scan multiple rodents simultaneously. However, this is achieved at the expense of deterioration of image quality and loss of quantitative accuracy owing to enhanced effects of photon attenuation and Compton scattering. The purpose of this work is, first, to characterize the magnitude and spatial distribution of the scatter component in small-animal PET imaging when scanning single and multiple rodents simultaneously and, second, to assess the relevance and evaluate the performance of scatter correction under similar conditions. The LabPET™-8 scanner was modelled as realistically as possible using Geant4 Application for Tomographic Emission Monte Carlo simulation platform. Monte Carlo simulations allow the separation of unscattered and scattered coincidences and as such enable detailed assessment of the scatter component and its origin. Simple shape-based and more realistic voxel-based phantoms were used to simulate single and multiple PET imaging studies. The modelled scatter component using the single-scatter simulation technique was compared to Monte Carlo simulation results. PET images were also corrected for attenuation and the combined effect of attenuation and scatter on single and multiple small-animal PET imaging evaluated in terms of image quality and quantitative accuracy. A good agreement was observed between calculated and Monte Carlo simulated scatter profiles for single- and multiple-subject imaging. In the LabPET™-8 scanner, the detector covering material (kovar) contributed the maximum amount of scatter events while the scatter contribution due to lead shielding is negligible. The out-of field-of-view (FOV) scatter fraction (SF) is 1.70, 0.76, and 0.11% for lower energy thresholds of 250, 350, and 400 keV, respectively. The increase in SF

  12. Investigations of Pet Animal Breeding Trends in Sivas

    Directory of Open Access Journals (Sweden)

    Yusuf Ziya Oğrak

    2014-04-01

    Full Text Available The aim of the study was to determine the present situation and future trends of pet which a member of our home in central Anatolian city of Sivas. For this purpose, 100 people (73 male, 27 female used with face to face interviews in the questionnaire aged 18-72 (mean 32.25, monthly income changed 400-5000 Turkish Liras (average 1841 and, 16 questions except for personal information were asked to participants. Participants, 51% graduated the university, 46% married, 82% lived in apartments, and 64% of the occupied own houses or belonging to their family have been identified. According to the findings, any breeders of pet in the house in Sivas rate were 31%. and, the people's income level , gender , age , marital status , educational level , having a child and the seat of the house with a garden and the lack of this on the ratio statistically not significant was observed. Highest percentage pet in species of breeding animals was the bird and, 48.4% of those pet owners did not go to the veterinarian at all and, 24.6% of non-animal’s previously had a bad incident with animals that have been identified. As a result, in terms of veterinary importance will increase day by day with pet animal breeding priorities for the further dissemination of the determination of the current situation and problems are seen to be important and, larger-scale research to be done will be helpful.

  13. Radiation exposure during transmission measurements: comparison between CT- and germanium-based techniques with a current PET scanner

    International Nuclear Information System (INIS)

    Wu, Tung-Hsin; Huang, Yung-Hui; Lee, Jason J.S.; Wang, Shih-Yuan; Wang, Su-Cheng; Su, Cheng-Tau; Chen, Liang-Kung; Chu, Tieh-Chi

    2004-01-01

    In positron emission tomographic (PET) scanning, transmission measurements for attenuation correction are commonly performed by using external germanium-68 rod sources. Recently, combined PET and computed tomographic (CT) scanners have been developed in which the CT data can be used for both anatomical-metabolic image formation and attenuation correction of the PET data. The purpose of this study was to evaluate the difference between germanium- and CT-based transmission scanning in terms of their radiation doses by using the same measurement technique and to compare the doses that patients receive during brain, cardiac and whole-body scans. Measurement of absorbed doses to organs was conducted by using a Rando Alderson phantom with thermoluminescent dosimeters. Effective doses were calculated according to the guidelines in the International Commission on Radiation Protection Publication Number 60. Compared with radionuclide doses used in routine 2-[fluorine-18]-fluoro-2-deoxy-d-glucose PET imaging, doses absorbed during germanium-based transmission scans were almost negligible. On the other hand, absorbed doses from CT-based transmission scans were significantly higher, particularly with a whole-body scanning protocol. Effective doses were 8.81 mSv in the high-speed mode and 18.97 mSv in the high-quality mode for whole-body CT-based transmission scans. These measurements revealed that the doses received by a patient during CT-based transmission scanning are more than those received in a typical PET examination. Therefore, the radiation doses represent a limitation to the generalised use of CT-based transmission measurements with current PET/CT scanner systems. (orig.)

  14. PET/MR in children. Initial clinical experience in paediatric oncology using an integrated PET/MR scanner

    International Nuclear Information System (INIS)

    Hirsch, Franz Wolfgang; Sorge, Ina; Viehweger, Adrian; Ritter, Lutz; Sattler, Bernhard; Kurch, Lars; Werner, Peter; Jochimsen, Thies; Barthel, Henryk; Sabri, Osama; Kluge, Regine; Bierbach, Uta; Till, Holger

    2013-01-01

    Use of PET/MR in children has not previously been reported, to the best of our knowledge. Children with systemic malignancies may benefit from the reduced radiation exposure offered by PET/MR. We report our initial experience with PET/MR hybrid imaging and our current established sequence protocol after 21 PET/MR studies in 15 children with multifocal malignant diseases. The effective dose of a PET/MR scan was only about 20% that of the equivalent PET/CT examination. Simultaneous acquisition of PET and MR data combines the advantages of the two previously separate modalities. Furthermore, the technique also enables whole-body diffusion-weighted imaging (DWI) and statements to be made about the biological cellularity and nuclear/cytoplasmic ratio of tumours. Combined PET/MR saves time and resources. One disadvantage of PET/MR is that in order to have an effect, a significantly longer examination time is needed than with PET/CT. In our initial experience, PET/MR has turned out to be an unexpectedly stable and reliable hybrid imaging modality, which generates a complementary diagnostic study of great additional value. (orig.)

  15. PET/MR in children. Initial clinical experience in paediatric oncology using an integrated PET/MR scanner

    Energy Technology Data Exchange (ETDEWEB)

    Hirsch, Franz Wolfgang; Sorge, Ina; Viehweger, Adrian; Ritter, Lutz [University of Leipzig, Department of Paediatric Radiology, Leipzig (Germany); Sattler, Bernhard; Kurch, Lars; Werner, Peter; Jochimsen, Thies; Barthel, Henryk; Sabri, Osama; Kluge, Regine [University of Leipzig, Department of Nuclear Medicine, Leipzig (Germany); Bierbach, Uta [University of Leipzig, Department of Paediatric Oncology, Leipzig (Germany); Till, Holger [University of Leipzig, Department of Paediatric Surgery, Leipzig (Germany)

    2013-07-15

    Use of PET/MR in children has not previously been reported, to the best of our knowledge. Children with systemic malignancies may benefit from the reduced radiation exposure offered by PET/MR. We report our initial experience with PET/MR hybrid imaging and our current established sequence protocol after 21 PET/MR studies in 15 children with multifocal malignant diseases. The effective dose of a PET/MR scan was only about 20% that of the equivalent PET/CT examination. Simultaneous acquisition of PET and MR data combines the advantages of the two previously separate modalities. Furthermore, the technique also enables whole-body diffusion-weighted imaging (DWI) and statements to be made about the biological cellularity and nuclear/cytoplasmic ratio of tumours. Combined PET/MR saves time and resources. One disadvantage of PET/MR is that in order to have an effect, a significantly longer examination time is needed than with PET/CT. In our initial experience, PET/MR has turned out to be an unexpectedly stable and reliable hybrid imaging modality, which generates a complementary diagnostic study of great additional value. (orig.)

  16. PET/MR in children. Initial clinical experience in paediatric oncology using an integrated PET/MR scanner.

    Science.gov (United States)

    Hirsch, Franz Wolfgang; Sattler, Bernhard; Sorge, Ina; Kurch, Lars; Viehweger, Adrian; Ritter, Lutz; Werner, Peter; Jochimsen, Thies; Barthel, Henryk; Bierbach, Uta; Till, Holger; Sabri, Osama; Kluge, Regine

    2013-07-01

    Use of PET/MR in children has not previously been reported, to the best of our knowledge. Children with systemic malignancies may benefit from the reduced radiation exposure offered by PET/MR. We report our initial experience with PET/MR hybrid imaging and our current established sequence protocol after 21 PET/MR studies in 15 children with multifocal malignant diseases. The effective dose of a PET/MR scan was only about 20% that of the equivalent PET/CT examination. Simultaneous acquisition of PET and MR data combines the advantages of the two previously separate modalities. Furthermore, the technique also enables whole-body diffusion-weighted imaging (DWI) and statements to be made about the biological cellularity and nuclear/cytoplasmic ratio of tumours. Combined PET/MR saves time and resources. One disadvantage of PET/MR is that in order to have an effect, a significantly longer examination time is needed than with PET/CT. In our initial experience, PET/MR has turned out to be an unexpectedly stable and reliable hybrid imaging modality, which generates a complementary diagnostic study of great additional value.

  17. Evaluation of attenuation and scatter correction requirements in small animal PET and SPECT imaging

    Science.gov (United States)

    Konik, Arda Bekir

    Positron emission tomography (PET) and single photon emission tomography (SPECT) are two nuclear emission-imaging modalities that rely on the detection of high-energy photons emitted from radiotracers administered to the subject. The majority of these photons are attenuated (absorbed or scattered) in the body, resulting in count losses or deviations from true detection, which in turn degrades the accuracy of images. In clinical emission tomography, sophisticated correction methods are often required employing additional x-ray CT or radionuclide transmission scans. Having proven their potential in both clinical and research areas, both PET and SPECT are being adapted for small animal imaging. However, despite the growing interest in small animal emission tomography, little scientific information exists about the accuracy of these correction methods on smaller size objects, and what level of correction is required. The purpose of this work is to determine the role of attenuation and scatter corrections as a function of object size through simulations. The simulations were performed using Interactive Data Language (IDL) and a Monte Carlo based package, Geant4 application for emission tomography (GATE). In IDL simulations, PET and SPECT data acquisition were modeled in the presence of attenuation. A mathematical emission and attenuation phantom approximating a thorax slice and slices from real PET/CT data were scaled to 5 different sizes (i.e., human, dog, rabbit, rat and mouse). The simulated emission data collected from these objects were reconstructed. The reconstructed images, with and without attenuation correction, were compared to the ideal (i.e., non-attenuated) reconstruction. Next, using GATE, scatter fraction values (the ratio of the scatter counts to the total counts) of PET and SPECT scanners were measured for various sizes of NEMA (cylindrical phantoms representing small animals and human), MOBY (realistic mouse/rat model) and XCAT (realistic human model

  18. 15 CFR 265.43 - Pets and other animals.

    Science.gov (United States)

    2010-01-01

    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Pets and other animals. 265.43 Section... INSTITUTE OF STANDARDS AND TECHNOLOGY, DEPARTMENT OF COMMERCE REGULATIONS GOVERNING TRAFFIC AND CONDUCT REGULATIONS GOVERNING TRAFFIC AND CONDUCT ON THE GROUNDS OF THE NATIONAL INSTITUTE OF STANDARDS & TECHNOLOGY...

  19. Molecular Imaging with Small Animal PET/CT

    DEFF Research Database (Denmark)

    Binderup, T.; El-Ali, H.H.; Skovgaard, D.

    2011-01-01

    Small animal positron emission tomography (PET) and computer tomography (CT) is an emerging field in pre-clinical imaging. High quality, state-of-the-art instruments are required for full optimization of the translational value of the small animal studies with PET and CT. However...... in this field of small animal molecular imaging with special emphasis on the targets for tissue characterization in tumor biology such as hypoxia, proliferation and cancer specific over-expression of receptors. The added value of applying CT imaging for anatomical localization and tumor volume measurements...... is also described. In addition, the non-invasive nature of molecular imaging and the targets of these promising new tracers are attractive for other research areas as well, although these fields are much less explored. We present an example of an interesting research field with the application of small...

  20. PKU-PET-II: A novel SiPM-based PET imaging system for small animals

    Science.gov (United States)

    Xie, Zhaoheng; Li, Suying; Zhou, Kun; Vuletic, Ivan; Meng, Xiangxi; Zhu, Sihao; Xu, Huan; Yang, Kun; Xu, Baixuan; Zhang, Jinming; Ren, Qiushi

    2018-01-01

    The objective of this study was to introduce, describe, and validate the performance of a novel preclinical silicon photomultiplier (SiPM)-based PET system (PKU-PET-II). Briefly, the detector assembly consisted of cerium-doped lutetium-yttrium oxyorthosilicate (LYSO) crystals, with dimensions of 2 ×2 ×15 mm3, that offered a 60 mm transaxial field of view (FOV) and 32 mm axial FOV, respectively. The compact front-end electronics readout and digital controller implemented architecture in the FPGA were noteworthy improvements in PKU-PET-II over its predecessor (PKU-PET-I). Based on the National Electrical Manufacturers Association (NEMA) NU 04-2008 standards, the design of the PKU-PET-II system was validated by a phantom experiment. The results presented spatial resolution (evaluated as full width at half maximum) with a system range from 1.68 ±0.07 to 2.31 ±0.03 mm at the FOV center and from 1.43 ±0.02 to 2.10 ±0.10 mm at the 1/4th axial FOV, respectively. The system's absolute sensitivity at the center position was 1.35% with the coincidence window of 6 ns and energy window of 300-700 keV. In addition, the NEMA image quality phantom and an animal study results validated the system imaging performance in preclinical imaging application. In conclusion, this SiPM-based, small-animal PET system (PKU-PET-II) provided higher-resolution, adequate sensitivity, and excellent image quality and has potential as a useful tool for real-time imaging of disease progression and development in vivo.

  1. Verslag 20th Symposium on Housing and Fiseases of Rabbits, Furprovinding animals and Pet animals

    NARCIS (Netherlands)

    Rommers, J.M.

    2017-01-01

    Op 17 en 18 mei jl. werd in Celle (Duitsland) het Symposium on Housing
    and Diseases of Rabbits, Furproviding animals and Pet animals
    gehouden. Dit symposium wordt eenmaal per twee jaar georganiseerd
    door Duitsland. Er waren circa 60 deelnemers uit 12 verschillende
    landen, waaronder

  2. Initial reconstruction results from a simulated adaptive small animal C shaped PET/MR insert

    Energy Technology Data Exchange (ETDEWEB)

    Efthimiou, Nikos [Technological Educational Institute of Athens (Greece); Kostou, Theodora; Papadimitroulas, Panagiotis [Technological Educational Institute of Athens (Greece); Department of Medical Physics, School of Medicine, University of Patras (Greece); Charalampos, Tsoumpas [Division of Biomedical Imaging, University of Leeds, Leeds (United Kingdom); Loudos, George [Technological Educational Institute of Athens (Greece)

    2015-05-18

    Traditionally, most clinical and preclinical PET scanners, rely on full cylindrical geometry for whole body as well as dedicated organ scans, which is not optimized with regards to sensitivity and resolution. Several groups proposed the construction of dedicated PET inserts for MR scanners, rather than the construction of new integrated PET/MR scanners. The space inside an MR scanner is a limiting factor which can be reduced further with the use of extra coils, and render the use of non-flexible cylindrical PET scanners difficult if not impossible. The incorporation of small SiPM arrays, can provide the means to design adaptive PET scanners to fit in tight locations, which, makes imaging possible and improve the sensitivity, due to the closer approximation to the organ of interest. In order to assess the performance of such a device we simulated the geometry of a C shaped PET, using GATE. The design of the C-PET was based on a realistic SiPM-BGO scenario. In order reconstruct the simulated data, with STIR, we had to calculate system probability matrix which corresponds to this non standard geometry. For this purpose we developed an efficient multi threaded ray tracing technique to calculate the line integral paths in voxel arrays. One of the major features is the ability to automatically adjust the size of FOV according to the geometry of the detectors. The initial results showed that the sensitivity improved as the angle between the detector arrays increases, thus better angular sampling the scanner's field of view (FOV). The more complete angular coverage helped in improving the shape of the source in the reconstructed images, as well. Furthermore, by adapting the FOV to the closer to the size of the source, the sensitivity per voxel is improved.

  3. Initial reconstruction results from a simulated adaptive small animal C shaped PET/MR insert

    International Nuclear Information System (INIS)

    Efthimiou, Nikos; Kostou, Theodora; Papadimitroulas, Panagiotis; Charalampos, Tsoumpas; Loudos, George

    2015-01-01

    Traditionally, most clinical and preclinical PET scanners, rely on full cylindrical geometry for whole body as well as dedicated organ scans, which is not optimized with regards to sensitivity and resolution. Several groups proposed the construction of dedicated PET inserts for MR scanners, rather than the construction of new integrated PET/MR scanners. The space inside an MR scanner is a limiting factor which can be reduced further with the use of extra coils, and render the use of non-flexible cylindrical PET scanners difficult if not impossible. The incorporation of small SiPM arrays, can provide the means to design adaptive PET scanners to fit in tight locations, which, makes imaging possible and improve the sensitivity, due to the closer approximation to the organ of interest. In order to assess the performance of such a device we simulated the geometry of a C shaped PET, using GATE. The design of the C-PET was based on a realistic SiPM-BGO scenario. In order reconstruct the simulated data, with STIR, we had to calculate system probability matrix which corresponds to this non standard geometry. For this purpose we developed an efficient multi threaded ray tracing technique to calculate the line integral paths in voxel arrays. One of the major features is the ability to automatically adjust the size of FOV according to the geometry of the detectors. The initial results showed that the sensitivity improved as the angle between the detector arrays increases, thus better angular sampling the scanner's field of view (FOV). The more complete angular coverage helped in improving the shape of the source in the reconstructed images, as well. Furthermore, by adapting the FOV to the closer to the size of the source, the sensitivity per voxel is improved.

  4. First results in the application of silicon photomultiplier matrices to small animal PET

    Energy Technology Data Exchange (ETDEWEB)

    Llosa, G. [University of Pisa, Department of Physics, Pisa (Italy)], E-mail: gabriela.llosa@pi.infn.it; Belcari, N.; Bisogni, M.G. [University of Pisa, Department of Physics, Pisa (Italy); INFN Pisa (Italy); Collazuol, G. [University of Pisa, Department of Physics, Pisa (Italy); Scuola Normale Superiore, Pisa (Italy); Marcatili, S. [University of Pisa, Department of Physics, Pisa (Italy); INFN Pisa (Italy); Boscardin, M.; Melchiorri, M.; Tarolli, A.; Piemonte, C.; Zorzi, N. [FBK irst, Trento (Italy); Barrillon, P.; Bondil-Blin, S.; Chaumat, V.; La Taille, C. de; Dinu, N.; Puill, V.; Vagnucci, J-F. [Laboratoire de l' Accelerateur Lineaire, IN2P3-CNRS, Orsay (France); Del Guerra, A. [University of Pisa, Department of Physics, Pisa (Italy); INFN Pisa (Italy)

    2009-10-21

    A very high resolution small animal PET scanner that employs matrices of silicon photomultipliers as photodetectors is under development at the University of Pisa and INFN Pisa. The first SiPM matrices composed of 16 (4x4)1mmx1mm pixel elements on a common substrate have been produced at FBK-irst, and are being evaluated for this application. The MAROC2 ASIC developed at LAL-Orsay has been employed for the readout of the SiPM matrices. The devices have been tested with pixelated and continuous LYSO crystals. The results show the good performance of the matrices and lead to the fabrication of matrices with 64 SiPM elements.

  5. First results in the application of silicon photomultiplier matrices to small animal PET

    International Nuclear Information System (INIS)

    Llosa, G.; Belcari, N.; Bisogni, M.G.; Collazuol, G.; Marcatili, S.; Boscardin, M.; Melchiorri, M.; Tarolli, A.; Piemonte, C.; Zorzi, N.; Barrillon, P.; Bondil-Blin, S.; Chaumat, V.; La Taille, C. de; Dinu, N.; Puill, V.; Vagnucci, J-F.; Del Guerra, A.

    2009-01-01

    A very high resolution small animal PET scanner that employs matrices of silicon photomultipliers as photodetectors is under development at the University of Pisa and INFN Pisa. The first SiPM matrices composed of 16 (4x4)1mmx1mm pixel elements on a common substrate have been produced at FBK-irst, and are being evaluated for this application. The MAROC2 ASIC developed at LAL-Orsay has been employed for the readout of the SiPM matrices. The devices have been tested with pixelated and continuous LYSO crystals. The results show the good performance of the matrices and lead to the fabrication of matrices with 64 SiPM elements.

  6. A PET system based on 2-18FDG production with a low energy electrostatic proton accelerator and a dual headed PET scanner.

    Science.gov (United States)

    Sandell, A; Ohlsson, T; Erlandsson, K; Hellborg, R; Strand, S E

    1992-01-01

    We have developed a comparatively inexpensive PET system, based on a rotating scanner with two scintillation camera heads, and a nearby low energy electrostatic proton accelerator for production of short-lived radionuclides. Using a 6 MeV proton beam of 5 microA, and by optimization of the target geometry for the 18O(p,n)18F reaction, 750 MBq of 2-18FDG can be obtained. The PET scanner shows a spatial resolution of 6 mm (FWHM) and a sensitivity of 80 s-1kBq-1ml-1 (3 kcps/microCi/ml). Various corrections are included in the imaging process, to compensate for spatial and temporal response variations in the detector system. Both filtered backprojection and iterative reconstruction methods are employed. Clinical studies have been performed with acquisition times of 30-40 min. The system will be used for clinical experimental research with short- as well as long-lived positron emitters. Also the possibility of true 3D reconstruction is under evaluation.

  7. Quantitative PET/CT scanner performance characterization based upon the society of nuclear medicine and molecular imaging clinical trials network oncology clinical simulator phantom.

    Science.gov (United States)

    Sunderland, John J; Christian, Paul E

    2015-01-01

    The Clinical Trials Network (CTN) of the Society of Nuclear Medicine and Molecular Imaging (SNMMI) operates a PET/CT phantom imaging program using the CTN's oncology clinical simulator phantom, designed to validate scanners at sites that wish to participate in oncology clinical trials. Since its inception in 2008, the CTN has collected 406 well-characterized phantom datasets from 237 scanners at 170 imaging sites covering the spectrum of commercially available PET/CT systems. The combined and collated phantom data describe a global profile of quantitative performance and variability of PET/CT data used in both clinical practice and clinical trials. Individual sites filled and imaged the CTN oncology PET phantom according to detailed instructions. Standard clinical reconstructions were requested and submitted. The phantom itself contains uniform regions suitable for scanner calibration assessment, lung fields, and 6 hot spheric lesions with diameters ranging from 7 to 20 mm at a 4:1 contrast ratio with primary background. The CTN Phantom Imaging Core evaluated the quality of the phantom fill and imaging and measured background standardized uptake values to assess scanner calibration and maximum standardized uptake values of all 6 lesions to review quantitative performance. Scanner make-and-model-specific measurements were pooled and then subdivided by reconstruction to create scanner-specific quantitative profiles. Different makes and models of scanners predictably demonstrated different quantitative performance profiles including, in some cases, small calibration bias. Differences in site-specific reconstruction parameters increased the quantitative variability among similar scanners, with postreconstruction smoothing filters being the most influential parameter. Quantitative assessment of this intrascanner variability over this large collection of phantom data gives, for the first time, estimates of reconstruction variance introduced into trials from allowing

  8. Development of a PET Insert for simultaneously small animal PET/MRI

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yingjie; Zhang, Zhiming; Li, Daowu; Liu, Shuangquan; Wang, Peilin; Feng, Baotong; Chai, Pei; Wei, Long [Division of Nuclear Technology and Applications, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049 (China); Beijing Engineering Research Center of Radiographic Techniques and Equipment, Beijing, 100049 (China)

    2015-05-18

    PET/MR is a new multi-modality imaging system which provide both structural and functional information with good soft tissue imaging ability and no ionizing radiation. In recent years, PET/MR is under major progress because of the development of silicon photomultipliers (SiPM). The goal of this study is to develop a MRI compatible PET insert based on SiPM and LYSO scintillator. The PET system was constituted by the detector ring, electronics and software. The detector ring consists of 16 detector module. The inner diameter of the ring was 151 mm, the external diameter was 216 mm, which was big enough for small animal research, e.g. rat, rabbit and tupaia. The sensor of each module was 2*2 SensL SPMArraySL, coupled with an array of 14 x 14 LYSO crystals, each crystal measuring 2 mm x 2 mm 10 mm. The detector was encapsulated in a copper box for light and magnetic shielding. Resister charge multiplexing circuit was used in the front end electronics. Each detector output 8X and 8Y position signals. One summed timing signal was extracted from the common cathode of all 64 channels. All these signals were transmitted to digital electronic board by a 3 m long coaxial cable from inside of the MR to the outside. Each digital electronic board handled 8 detector modules based on FPGA to obtain the timing, position and energy information of a single event. And then these single events were sent to the coincidence processing board to produce coincidence packets which are prepared for further processing. A 0.2mCi 68Ge line source was used to do the preliminary imaging test. The image was reconstructed by 3D-OSEM algorithm. The initial result proved the system to be feasible as a PET. FDG phantom imaging and simultaneous PET/MR imaging are in progress.

  9. Lesion detection and quantification performance of the Tachyon-I time-of-flight PET scanner: phantom and human studies

    Science.gov (United States)

    Zhang, Xuezhu; Peng, Qiyu; Zhou, Jian; Huber, Jennifer S.; Moses, William W.; Qi, Jinyi

    2018-03-01

    The first generation Tachyon PET (Tachyon-I) is a demonstration single-ring PET scanner that reaches a coincidence timing resolution of 314 ps using LSO scintillator crystals coupled to conventional photomultiplier tubes. The objective of this study was to quantify the improvement in both lesion detection and quantification performance resulting from the improved time-of-flight (TOF) capability of the Tachyon-I scanner. We developed a quantitative TOF image reconstruction method for the Tachyon-I and evaluated its TOF gain for lesion detection and quantification. Scans of either a standard NEMA torso phantom or healthy volunteers were used as the normal background data. Separately scanned point source and sphere data were superimposed onto the phantom or human data after accounting for the object attenuation. We used the bootstrap method to generate multiple independent noisy datasets with and without a lesion present. The signal-to-noise ratio (SNR) of a channelized hotelling observer (CHO) was calculated for each lesion size and location combination to evaluate the lesion detection performance. The bias versus standard deviation trade-off of each lesion uptake was also calculated to evaluate the quantification performance. The resulting CHO-SNR measurements showed improved performance in lesion detection with better timing resolution. The detection performance was also dependent on the lesion size and location, in addition to the background object size and shape. The results of bias versus noise trade-off showed that the noise (standard deviation) reduction ratio was about 1.1–1.3 over the TOF 500 ps and 1.5–1.9 over the non-TOF modes, similar to the SNR gains for lesion detection. In conclusion, this Tachyon-I PET study demonstrated the benefit of improved time-of-flight capability on lesion detection and ROI quantification for both phantom and human subjects.

  10. Full modelling of the MOSAIC animal PET system based on the GATE Monte Carlo simulation code

    International Nuclear Information System (INIS)

    Merheb, C; Petegnief, Y; Talbot, J N

    2007-01-01

    Positron emission tomography (PET) systems dedicated to animal imaging are now widely used for biological studies. The scanner performance strongly depends on the design and the characteristics of the system. Many parameters must be optimized like the dimensions and type of crystals, geometry and field-of-view (FOV), sampling, electronics, lightguide, shielding, etc. Monte Carlo modelling is a powerful tool to study the effect of each of these parameters on the basis of realistic simulated data. Performance assessment in terms of spatial resolution, count rates, scatter fraction and sensitivity is an important prerequisite before the model can be used instead of real data for a reliable description of the system response function or for optimization of reconstruction algorithms. The aim of this study is to model the performance of the Philips Mosaic(TM) animal PET system using a comprehensive PET simulation code in order to understand and describe the origin of important factors that influence image quality. We use GATE, a Monte Carlo simulation toolkit for a realistic description of the ring PET model, the detectors, shielding, cap, electronic processing and dead times. We incorporate new features to adjust signal processing to the Anger logic underlying the Mosaic(TM) system. Special attention was paid to dead time and energy spectra descriptions. Sorting of simulated events in a list mode format similar to the system outputs was developed to compare experimental and simulated sensitivity and scatter fractions for different energy thresholds using various models of phantoms describing rat and mouse geometries. Count rates were compared for both cylindrical homogeneous phantoms. Simulated spatial resolution was fitted to experimental data for 18 F point sources at different locations within the FOV with an analytical blurring function for electronic processing effects. Simulated and measured sensitivities differed by less than 3%, while scatter fractions agreed

  11. Small Animal [18F]FDG PET Imaging for Tumor Model Study

    International Nuclear Information System (INIS)

    Woo, Sang Keun; Kim, Kyeong Min; Cheon, Gi Jeong

    2008-01-01

    PET allows non-invasive, quantitative and repetitive imaging of biological function in living animals. Small animal PET imaging with [ 18 F]FDG has been successfully applied to investigation of metabolism, receptor, ligand interactions, gene expression, adoptive cell therapy and somatic gene therapy. Experimental condition of animal handling impacts on the biodistribution of [ 18 F]FDG in small animal study. The small animal PET and CT images were registered using the hardware fiducial markers and small animal contour point. Tumor imaging in small animal with small animal [ 18 F]FDG PET should be considered fasting, warming, and isoflurane anesthesia level. Registered imaging with small animal PET and CT image could be useful for the detection of tumor. Small animal experimental condition of animal handling and registration method will be of most importance for small lesion detection of metastases tumor model

  12. Future of keeping pet reptiles and amphibians: animal welfare and public health perspective.

    Science.gov (United States)

    Warwick, C; Jessop, M; Arena, P; Pliny, A; Nicholas, E; Lambiris, A

    2017-10-28

    In a review summary on page 450, Pasmans and others discuss the future of keeping reptiles and amphibians as pets. Here, Clifford Warwick and others discuss the animal welfare and public health implications of exotic pet business. British Veterinary Association.

  13. Experimental MRI-SPECT insert system with Hybrid Semiconductor detectors Timepix for MR animal scanner Bruker 47/20

    Science.gov (United States)

    Zajicek, J.; Burian, M.; Soukup, P.; Novak, V.; Macko, M.; Jakubek, J.

    2017-01-01

    Multimodal medical imaging based on Magnetic Resonance is mainly combinated with one of the scintigraphic method like PET or SPECT. These methods provide functional information whereas magnetic resonance imaging provides high spatial resolution of anatomical information or complementary functional information. Fusion of imaging modalities allows researchers to obtain complimentary information in a single measurement. The combination of MRI with SPECT is still relatively new and challenging in many ways. The main complication of using SPECT in MRI systems is the presence of a high magnetic field therefore (ferro)magnetic materials have to be eliminated. Furthermore the application of radiofrequency fields within the MR gantry does not allow for the use of conductive structures such as the common heavy metal collimators. This work presents design and construction of an experimental MRI-SPECT insert system and its initial tests. This unique insert system consists of an MR-compatible SPECT setup with CdTe pixelated sensors Timepix tungsten collimators and a radiofrequency coil. Measurements were performed on a gelatine and tissue phantom with an embedded radioisotopic source (57Co 122 keV γ ray) inside the RF coil by the Bruker BioSpec 47/20 (4.7 T) MR animal scanner. The project was performed in the framework of the Medipix Collaboration.

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

    International Nuclear Information System (INIS)

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

    2014-01-01

    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

  15. Childhood pet ownership, attachment to pets, and subsequent meat avoidance. The mediating role of empathy toward animals.

    Science.gov (United States)

    Rothgerber, Hank; Mican, Frances

    2014-08-01

    Researchers studying childhood pet ownership outcomes do not typically focus on measures of adult diet, and those studying the psychology of meat consumption do not normally consider early experiences with companion animals. The present research sought to integrate these two areas by examining relationships between childhood pet ownership, pet attachment, empathy toward animals, belief in human-animal similarity, meat avoidance, and justifications for eating meat. Results from 273 individuals responding to a survey on an internet platform revealed that participants with greater childhood attachment to a pet reported greater meat avoidance as adults, an effect that disappeared when controlling for animal empathy. Greater childhood pet attachment was also related to the use of indirect, apologetic justifications for meat consumption, and this effect too, was mediated by empathy toward animals. Child pet ownership itself predicted views toward animals but not dietary behavior or meat-eating justifications. The authors propose a sequence of events by which greater childhood pet attachment leads to increased meat avoidance, focusing on the central role played by empathy toward animals. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Development of a prototype PET scanner with depth-of-interaction measurement using solid-state photomultiplier arrays and parallel readout electronics.

    Science.gov (United States)

    Shao, Yiping; Sun, Xishan; Lan, Kejian A; Bircher, Chad; Lou, Kai; Deng, Zhi

    2014-03-07

    In this study, we developed a prototype animal PET by applying several novel technologies to use solid-state photomultiplier (SSPM) arrays to measure the depth of interaction (DOI) and improve imaging performance. Each PET detector has an 8 × 8 array of about 1.9 × 1.9 × 30.0 mm(3) lutetium-yttrium-oxyorthosilicate scintillators, with each end optically connected to an SSPM array (16 channels in a 4 × 4 matrix) through a light guide to enable continuous DOI measurement. Each SSPM has an active area of about 3 × 3 mm(2), and its output is read by a custom-developed application-specific integrated circuit to directly convert analogue signals to digital timing pulses that encode the interaction information. These pulses are transferred to and are decoded by a field-programmable gate array-based time-to-digital convertor for coincident event selection and data acquisition. The independent readout of each SSPM and the parallel signal process can significantly improve the signal-to-noise ratio and enable the use of flexible algorithms for different data processes. The prototype PET consists of two rotating detector panels on a portable gantry with four detectors in each panel to provide 16 mm axial and variable transaxial field-of-view (FOV) sizes. List-mode ordered subset expectation maximization image reconstruction was implemented. The measured mean energy, coincidence timing and DOI resolution for a crystal were about 17.6%, 2.8 ns and 5.6 mm, respectively. The measured transaxial resolutions at the center of the FOV were 2.0 mm and 2.3 mm for images reconstructed with and without DOI, respectively. In addition, the resolutions across the FOV with DOI were substantially better than those without DOI. The quality of PET images of both a hot-rod phantom and mouse acquired with DOI was much higher than that of images obtained without DOI. This study demonstrates that SSPM arrays and advanced readout/processing electronics can be used to develop a practical DOI

  17. Molecular characterization of pneumococcal isolates from pets and laboratory animals.

    Directory of Open Access Journals (Sweden)

    Mark van der Linden

    Full Text Available BACKGROUND: Between 1986 and 2008 Streptococcus pneumoniae was isolated from 41 pets/zoo animals (guinea pigs (n = 17, cats (n = 12, horses (n = 4, dogs (n = 3, dolphins (n = 2, rat (n = 2, gorilla (n = 1 treated in medical veterinary laboratories and zoos, and 44 laboratory animals (mastomys (multimammate mice; n = 32, mice (n = 6, rats (n = 4, guinea pigs (n = 2 during routine health monitoring in an animal facility. S. pneumoniae was isolated from nose, lung and respiratory tract, eye, ear and other sites. METHODOLOGY/PRINCIPAL FINDINGS: Carriage of the same isolate of S. pneumoniae over a period of up to 22 weeks was shown for four mastomys. Forty-one animals showed disease symptoms. Pneumococcal isolates were characterized by optochin sensitivity, bile solubility, DNA hybridization, pneumolysin PCR, serotyping and multilocus sequence typing. Eighteen of the 32 mastomys isolates (56% were optochin resistant, all other isolates were optochin susceptible. All mastomys isolates were serotype 14, all guinea pig isolates serotype 19F, all horse isolates serotype 3. Rats had serotypes 14 or 19A, mice 33A or 33F. Dolphins had serotype 23F, the gorilla serotype 14. Cats and dogs had many different serotypes. Four isolates were resistant to macrolides, three isolates also to clindamycin and tetracycline. Mastomys isolates were sequence type (ST 15 (serotype 14, an ST/serotype combination commonly found in human isolates. Cats, dogs, pet rats, gorilla and dolphins showed various human ST/serotype combinations. Lab rats and lab mice showed single locus variants (SLV of human STs, in human ST/serotype combinations. All guinea pig isolates showed the same completely new combination of known alleles. The horse isolates showed an unknown allele combination and three new alleles. CONCLUSIONS/SIGNIFICANCE: The isolates found in mastomys, mice, rats, cats, dogs, gorilla and dolphins are most likely identical to human pneumococcal isolates. Isolates from

  18. Development and evaluation of an ultra-fast ASIC for future PET scanners using TOF-capable MPPC array detectors

    International Nuclear Information System (INIS)

    Ambe, T.; Ikeda, H.; Kataoka, J.; Matsuda, H.; Kato, T.

    2015-01-01

    We developed a front-end ASIC for future PET scanners with Time-Of-Flight (TOF) capability to be coupled with 4×4 Multi-Pixel Photon Counter (MPPC) arrays. The ASIC is designed based on the open-IP project proposed by JAXA and realized in TSMC 0.35 μm CMOS technology. The circuit comprises 16-channel, low impedance current conveyors for effectively acquiring fast MPPC signals. For precise measurement of the coincidence timing of 511-keV gamma rays, the leading-edge method was used to discriminate the signals. We first tested the time response of the ASIC by illuminating each channel of a MPPC array device 3×3 mm 2 in size with a Pico-second Light Pulsar with a light emission peak of 655 nm and pulse duration of 54 ps (FWHM). We obtained 105 ps (FWHM) on average for each channel in time jitter measurements. Moreover, we compensated for the time lag of each channel with inner delay circuits and succeeded in suppressing about a 700-ps lag to only 15 ps. This paper reports TOF measurements using back-to-back 511-keV signals, and suggests that the ASIC can be a promising device for future TOF-PET scanners based on the MPPC array. - Highlights: • We developed a newly designed large-area monolithic MPPC array. • We obtained fine gain uniformity, and good energy and time resolutions when coupled to the LYSO scintillator. • We fabricated gamma-ray camera consisting of the MPPC array and the submillimeter pixelized LYSO and GGAG scintillators. • In the flood images, each crystal of scintillator matrices was clearly resolved. • Good energy resolutions for 662 keV gamma-rays for each LYSO and GGAG scintillator matrices were obtained

  19. What about animals dealing with working dogs, pets and other animals during terrorism incidents and disasters

    International Nuclear Information System (INIS)

    Eifried, G.

    2009-01-01

    It is highly likely that K9 teams (patrol, search and rescue, and cadaver) will be exposed to hazardous materials as a result of an act of CBRN terrorism, and thus require decontamination. Service animals and pets which have been exposed to toxic agents and materials will also need to be decontaminated, along with their owners. Emergency evacuation and sheltering plans need to consider how service animals, pets and livestock will be handled. The United States has recently made significant changes to focus in this regard, to the extent that caring for animals must now be addressed in disaster preparedness planning. In this paper we describe lessons learned from work done by the Massachusetts Urban Search and Rescue Team (USAR), and the response to hurricane Katrina, concerning the handling and decontamination of animals following major incidents. We discuss: how the new Federal and state mandates have changed evacuation and sheltering concepts; cooperation among government entities, veterinarians, animal facilities, humane societies, animal rescue organizations and animal owners; and describe some practical considerations and solutions to sheltering and mass decontamination of animals along with their humans.(author)

  20. A Review of the Roles of Pet Animals in Psychotherapy and With the Elderly.

    Science.gov (United States)

    Brickel, Clark M.

    1980-01-01

    A survey of case histories, anecdotal evidence and pilot studies shows that, as therapeutic adjuncts, pet animals facilitate rapport and enrich the treatment milieu. Pets enhance the lives of their owners in the community. Pet-facilitated psychotherapy can increase social interaction, provide comfort, and reinforce feelings of independence.…

  1. Development of an inexpensive, low attenuation styrofoam primate chair for use in a PET scanner

    NARCIS (Netherlands)

    Kortekaas, R; van Waarde, A; Maguire, RP; Leenders, KL; Elsinga, PH

    Pharmacokinetic modelling of radiotracers for positron emission tomography (PET) imaging of neuroreceptors can be performed with time-activity data for brain and blood. We aimed to develop an alternative to withdrawal of arterial blood samples for acquisition of a blood curve. A supportive primate

  2. DigiPET: sub-millimeter spatial resolution small-animal PET imaging using thin monolithic scintillators

    Science.gov (United States)

    España, Samuel; Marcinkowski, Radoslaw; Keereman, Vincent; Vandenberghe, Stefaan; Van Holen, Roel

    2014-07-01

    A new preclinical PET system based on dSiPMs, called DigiPET, is presented. The system is based on thin monolithic scintillation crystals and exhibits superior spatial resolution at low-cost compared to systems based on pixelated crystals. Current dedicated small-rodent PET scanners have a spatial resolution in the order of 1 mm. Most of them have a large footprint, requiring considerable laboratory space. For rodent brain imaging, a PET scanner with sub-millimeter resolution is desired. To achieve this, crystals with a pixel pitch down to 0.5 mm have been used. However, fine pixels are difficult to produce and will render systems expensive. In this work, we present the first results with a high-resolution preclinical PET scanner based on thin monolithic scintillators and a large solid angle. The design is dedicated to rat-brain imaging and therefore has a very compact geometry. Four detectors were placed in a square arrangement with a distance of 34.5 mm between two opposing detector modules, defining a field of view (FOV) of 32 × 32 × 32 mm3. Each detector consists of a thin monolithic LYSO crystal of 32 × 32 × 2 mm3 optically coupled to a digital silicon photomultiplier (dSiPM). Event positioning within each detector was obtained using the maximum likelihood estimation (MLE) method. To evaluate the system performance, we measured the energy resolution, coincidence resolving time (CRT), sensitivity and spatial resolution. The image quality was evaluated by acquiring a hot-rod phantom filled with 18F-FDG and a rat head one hour after an 18F-FDG injection. The MLE yielded an average intrinsic spatial resolution on the detector of 0.54 mm FWHM. We obtained a CRT of 680 ps and an energy resolution of 18% FWHM at 511 keV. The sensitivity and spatial resolution obtained at the center of the FOV were 6.0 cps kBq-1 and 0.7 mm, respectively. In the reconstructed images of the hot-rod phantom, hot rods down to 0.7 mm can be discriminated. In conclusion, a compact PET

  3. DigiPET: sub-millimeter spatial resolution small-animal PET imaging using thin monolithic scintillators

    International Nuclear Information System (INIS)

    España, Samuel; Marcinkowski, Radoslaw; Keereman, Vincent; Vandenberghe, Stefaan; Van Holen, Roel

    2014-01-01

    A new preclinical PET system based on dSiPMs, called DigiPET, is presented. The system is based on thin monolithic scintillation crystals and exhibits superior spatial resolution at low-cost compared to systems based on pixelated crystals. Current dedicated small-rodent PET scanners have a spatial resolution in the order of 1 mm. Most of them have a large footprint, requiring considerable laboratory space. For rodent brain imaging, a PET scanner with sub-millimeter resolution is desired. To achieve this, crystals with a pixel pitch down to 0.5 mm have been used. However, fine pixels are difficult to produce and will render systems expensive. In this work, we present the first results with a high-resolution preclinical PET scanner based on thin monolithic scintillators and a large solid angle. The design is dedicated to rat-brain imaging and therefore has a very compact geometry. Four detectors were placed in a square arrangement with a distance of 34.5 mm between two opposing detector modules, defining a field of view (FOV) of 32 × 32 × 32 mm 3 . Each detector consists of a thin monolithic LYSO crystal of 32 × 32 × 2 mm 3  optically coupled to a digital silicon photomultiplier (dSiPM). Event positioning within each detector was obtained using the maximum likelihood estimation (MLE) method. To evaluate the system performance, we measured the energy resolution, coincidence resolving time (CRT), sensitivity and spatial resolution. The image quality was evaluated by acquiring a hot-rod phantom filled with 18 F-FDG and a rat head one hour after an 18 F-FDG injection. The MLE yielded an average intrinsic spatial resolution on the detector of 0.54 mm FWHM. We obtained a CRT of 680 ps and an energy resolution of 18% FWHM at 511 keV. The sensitivity and spatial resolution obtained at the center of the FOV were 6.0 cps kBq −1  and 0.7 mm, respectively. In the reconstructed images of the hot-rod phantom, hot rods down to 0.7 mm can be discriminated

  4. Pet Face: Mechanisms Underlying Human-Animal Relationships.

    Science.gov (United States)

    Borgi, Marta; Cirulli, Francesca

    2016-01-01

    Accumulating behavioral and neurophysiological studies support the idea of infantile (cute) faces as highly biologically relevant stimuli rapidly and unconsciously capturing attention and eliciting positive/affectionate behaviors, including willingness to care. It has been hypothesized that the presence of infantile physical and behavioral features in companion (or pet) animals (i.e., dogs and cats) might form the basis of our attraction to these species. Preliminary evidence has indeed shown that the human attentional bias toward the baby schema may extend to animal facial configurations. In this review, the role of facial cues, specifically of infantile traits and facial signals (i.e., eyes gaze) as emotional and communicative signals is highlighted and discussed as regulating the human-animal bond, similarly to what can be observed in the adult-infant interaction context. Particular emphasis is given to the neuroendocrine regulation of the social bond between humans and animals through oxytocin secretion. Instead of considering companion animals as mere baby substitutes for their owners, in this review we highlight the central role of cats and dogs in human lives. Specifically, we consider the ability of companion animals to bond with humans as fulfilling the need for attention and emotional intimacy, thus serving similar psychological and adaptive functions as human-human friendships. In this context, facial cuteness is viewed not just as a releaser of care/parental behavior, but, more in general, as a trait motivating social engagement. To conclude, the impact of this information for applied disciplines is briefly described, particularly in consideration of the increasing evidence of the beneficial effects of contacts with animals for human health and wellbeing.

  5. PET FACE: MECHANISMS UNDERLYING HUMAN-ANIMAL RELATIONSHIPS

    Directory of Open Access Journals (Sweden)

    Marta eBorgi

    2016-03-01

    Full Text Available Accumulating behavioral and neurophysiological studies support the idea of infantile (cute faces as highly biologically relevant stimuli rapidly and unconsciously capturing attention and eliciting positive/affectionate behaviors, including willingness to care. It has been hypothesized that the presence of infantile physical and behavioral features in companion (or pet animals (i.e. dogs and cats might form the basis of our attraction to these species. Preliminary evidence has indeed shown that the human attentional bias toward the baby schema may extend to animal facial configurations. In this review, the role of facial cues, specifically of infantile traits and facial signals (i.e. eyes gaze as emotional and communicative signals is highlighted and discussed as regulating human-animal bond, similarly to what can be observed in the adult-infant interaction context. Particular emphasis is given to the neuroendocrine regulation of social bond between humans and animals through oxytocin secretion. Instead of considering companion animals as mere baby substitutes for their owners, in this review we highlight the central role of cats and dogs in human lives. Specifically, we consider the ability of companion animals to bond with humans as fulfilling the need for attention and emotional intimacy, thus serving similar psychological and adaptive functions as human-human friendships. In this context, facial cuteness is viewed not just as a releaser of care/parental behavior, but more in general as a trait motivating social engagement. To conclude, the impact of this information for applied disciplines is briefly described, particularly in consideration of the increasing evidence of the beneficial effects of contacts with animals for human health and wellbeing.

  6. An investigation of the challenges in reconstructing PET images of a freely moving animal

    International Nuclear Information System (INIS)

    Akhtar, Mahmood; Kyme, Andre; Meikle, Steven; Zhou, Victor; Fulton, Roger

    2013-01-01

    Imaging the brain of a freely moving small animal using positron emission tomography (PET) while simultaneously observing its behaviour is an important goal for neuroscience. While we have successfully demonstrated the use of line-of-response (LOR) rebinning to correct the head motion of confined animals, a large proportion of events may need to be discarded because they either 'miss' the detector array after transformation or fall out of the acceptance range of a sinogram. The proportion of events that would have been measured had motion not occurred, so-called 'lost events', is expected to be even larger for freely moving animals. Moreover, the data acquisition in the case of a freely moving animal is further complicated by a complex attenuation field. The aims of this study were (a) to characterise the severity of 'lost events' problem for the freely moving animal scenario, and (b) to investigate the relative impact of attenuation correction errors on quantitative accuracy of reconstructed images. A phantom study was performed to simulate the uncorrelated motion of a target and non-target source volume. A small animal PET scanner was used to acquire list-mode data for different sets of phantom positions. The list-mode data were processed using the standard LOR rebinning approach, and multiple frame variants of this designed to reduce discarded events. We found that LOR rebinning caused up to 86 % 'lost events', and artifacts that we attribute to incomplete projections, when applied to a freely moving target. This fraction was reduced by up to 18 % using the variant approaches, resulting in slightly reduced image artifacts. The effect of the non-target compartment on attenuation correction of the target volume was surprisingly small. However, for certain poses where the target and non-target volumes are aligned transaxially in the field-of-view, the attenuation problem becomes more complex and sophisticated correction methods will be required. We conclude that

  7. Studies oriented to optimize the image quality of the small animal PET: Clear PET, modifying some of the parameters of the reconstruction algorithm IMF-OSEM 3D on the data acquisition simulated with GAMOS; Estudios para la optimizaciOn de la calidad de imagen en el escaner ClearPET, modifi cando parametros del algoritmo IMF-OSEM 3D sobre adquisiciones simuladas con GAMOS

    Energy Technology Data Exchange (ETDEWEB)

    Canadas, M.; Mendoza, J.; Embid, M.

    2007-09-27

    This report presents studies oriented to optimize the image quality of the small animal PET: Clear- PET. Certain figures of merit (FOM) were used to assess a quantitative value of the contrast and delectability of lesions. The optimization was carried out modifying some of the parameters in the reconstruction software of the scanner, imaging a mini-Derenzo phantom and a cylinder phantom with background activity and two hot spheres. Specifically, it was evaluated the incidence of the inter-update Metz filter (IMF) inside the iterative reconstruction algorithm 3D OSEM. The data acquisition was simulated using the GAMOS framework (Monte Carlo simulation). Integrating GAMOS output with the reconstruction software of the scanner was an additional novelty of this work, to achieve this, data sets were written with the list-mode format (LMF) of ClearPET. In order to verify the optimum values obtained, we foresee to make real acquisitions in the ClearPET of CIEMAT. (Author) 17 refs.

  8. Companion animal welfare and possible implications on the human-pet relationship

    Directory of Open Access Journals (Sweden)

    Marina Verga

    2010-01-01

    Full Text Available The role of pets (dogs and cats in particular in human society has changed in recent years. Nowadays pets are an integral part of the human family and this aspect has many social and emotional implications. For their positive effects on human health, pets are also employed in some special and therapeutic activities known by the generic term of “Pet Therapy”. In these programmes the animal becomes an integral part of the therapeutic plan in order to induce some physical, social, emotional, and cognitive improvements in human patients. However, the close bond between companion animals and man is not always the herald of beneficial effects. Sometimes the welfare of pets may be compromised by distress due to many factors, mostly related to the environment and to management by humans. Both behavioural and physiological variables may be analysed in order to evaluate welfare level in pets. Reduced welfare may be indicated by the onset of some behavioural problems, which have usually a multifactorial aetiology, related both to the genetic individual basis and environmental factors. Physiological variables which may be analysed in order to evaluate pet welfare include hormone levels, mainly related to the HPA (hypothalamus-pituitary-adrenal- axis and to the immune systems activations. Behavioural problems may also lead to the relinquishment of pets to shelters. Animals housed in rescue shelters cannot display their ethogram and show behavioural and physiological signs of distress. Thus it is very important to improve the human-pet relationship both by educating owners and reducing the number of stray animals, in accordance with the indications of the European Convention for the Protection of Pet Animals stated at Strasbourg in 1987, mainly as regards pet breeding and welfare. Humans have to realise that adopting pets implies the responsibility to care for their health and welfare, avoiding undue stress in the living environment and improving the

  9. Small animal PET based on 16x16 TSV-MPPCs and monolithic crystals

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, Antonio; Aguilar, Albert Talens; Conde, Pablo; Hernadez, Liczandro Hernadez; Vidal San Sebastian, Luis Fernando [Institute for Instrumentation in Molecular Imaging, i3M-CSIC, Valencia (Spain); Salbador, Carlos Correcher; Solsona, Cesar Molinos [Oncovision, Valencia (Spain); Junge, Sven; Lankes, Konrad [Bruker BioSpin (Germany); Benlloch, Jose Maria [Institute for Instrumentation in Molecular Imaging, i3M-CSIC, Valencia (Spain)

    2015-05-18

    In this work we present the design of a small animal PET based on 8 high-density arrays of MPPCs and monolithic scintillators. The MPPCs arrays are composed of 16x16 TSV-type (3x3 mm{sup 2}) elements covering a rough active area of 5x5 cm{sup 2}. A single LYSO block with a thickness of 10mm has been mounted on each detector. Black paint has been applied to the entrance and lateral faces of the crystal to preserve the scintillation light distribution. The axial and transaxial FOVs of one ring are 48 mm and 80 mm, respectively. Each MPPC array has been directly attached to a resistive readout circuit that provides outputs for each row and column of the array. These 32 signals are read with flexible boards 30 cm apart from the PET detector without any additional connectors in between. The PET-system is intended for in-line acquisition in front of MR scanners and as PET-insert inside the sensitive MRI volume. For this purpose, it is necessary to avoid magnetic sensible materials, such as nickel, and to prevent eddy currents in metallic structures induced by the MRI gradients. All detectors are air cooled and kept at temperatures of approximately 20{sup o}C with a variation below 0.05{sup o}C. The intrinsic resolution is 2.2 mm at the crystal center (averaged over all 2.6 mm) when Center of Gravity methods are used to resolve the impact position. This value is about a factor 1.5 better than results obtained with the H8500 PSPMT (64 PADs) and similar scintillators. With an improved collimator with holes with only 0.8mm diameter and a length of 70 mm, an intrinsic detector resolution of 1.1mm was reached. The energy resolutions of ROIs of 1x1 cm{sup 2} showed FWHM values in the range of 14%.

  10. Characterization of dual layer phoswich detector performance for small animal PET using Monte Carlo simulation

    International Nuclear Information System (INIS)

    Chung, Yong Hyun; Choi, Yong; Cho, Gyuseong; Choe, Yearn Seong; Lee, Kyung-Han; Kim, Byung-Tae

    2004-01-01

    A positron emission tomograph dedicated to small animal imaging should have high spatial resolution and sensitivity, and dual layer scintillators have been developed for this purpose. In this study, simulations were performed to optimize the order and the length of each crystal of a dual layer phoswich detector, and to evaluate the possibility of measuring signals from each layer of the phoswich detector. A simulation tool GATE was used to estimate the sensitivity and resolution of a small PET scanner. The proposed scanner is based on dual layer phoswich detector modules arranged in a ring of 10 cm diameter. Each module is composed of 8 x 8 arrays of phoswich detectors consisting of LSO and LuYAP with a 2 mm x 2 mm sensitive area coupled to a Hamamatsu R7600-00-M64 PSPMT. The length of the front layer of the phoswich detector varied from 0 to 10 mm at 1 mm intervals, and the total length (LSO + LuYAP) was fixed at 20 mm. The order of the crystal layers of the phoswich detector was also changed. Radial resolutions were kept below 3.4 mm and 3.7 mm over 8 cm FOV, and sensitivities were 7.4% and 8.0% for LSO 5 mm-LuYAP 15 mm, and LuYAP 6 mm-LSO 14 mm phoswich detectors, respectively. Whereas, high and uniform resolutions were achieved by using the LSO front layer, higher sensitivities were obtained by changing the crystal order. The feasibilities for applying crystal identification methods to phoswich detectors consisting of LSO and LuYAP were investigated using simulation and experimentally derived measurements of the light outputs from each layer of the phoswich detector. In this study, the optimal order and lengths of the dual layer phoswich detector were derived in order to achieve high sensitivity and high and uniform radial resolution

  11. Investigation of time-of-flight benefits in an LYSO-based PET/CT scanner: A Monte Carlo study using GATE

    Energy Technology Data Exchange (ETDEWEB)

    Geramifar, P. [Faculty of Physics and Nuclear Engineering, Amir Kabir University of Technology (Tehran Polytechnic), Tehran (Iran, Islamic Republic of); Research Center for Science and Technology in Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Research Institute for Nuclear Medicine, Tehran University of Medical Sciences, Shariati Hospital, Tehran (Iran, Islamic Republic of); Ay, M.R., E-mail: mohammadreza_ay@tums.ac.ir [Research Center for Science and Technology in Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Research Institute for Nuclear Medicine, Tehran University of Medical Sciences, Shariati Hospital, Tehran (Iran, Islamic Republic of); Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Shamsaie Zafarghandi, M. [Faculty of Physics and Nuclear Engineering, Amir Kabir University of Technology (Tehran Polytechnic), Tehran (Iran, Islamic Republic of); Sarkar, S. [Research Center for Science and Technology in Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Research Institute for Nuclear Medicine, Tehran University of Medical Sciences, Shariati Hospital, Tehran (Iran, Islamic Republic of); Loudos, G. [Department of Medical Instruments Technology, Technological Educational Institute, Athens (Greece); Rahmim, A. [Department of Radiology, School of Medicine, Johns Hopkins University, Baltimore (United States); Department of Electrical and Computer Engineering, School of Engineering, Johns Hopkins University, Baltimore (United States)

    2011-06-11

    The advent of fast scintillators yielding great light yield and/or stopping power, along with advances in photomultiplier tubes and electronics, have rekindled interest in time-of-flight (TOF) PET. Because the potential performance improvements offered by TOF PET are substantial, efforts to improve PET timing should prove very fruitful. In this study, we performed Monte Carlo simulations to explore what gains in PET performance could be achieved if the coincidence resolving time (CRT) in the LYSO-based PET component of Discovery RX PET/CT scanner were improved. For this purpose, the GATE Monte Carlo package was utilized, providing the ability to model and characterize various physical phenomena in PET imaging. For the present investigation, count rate performance and signal to noise ratio (SNR) values in different activity concentrations were simulated for different coincidence timing windows of 4, 5.85, 6, 6.5, 8, 10 and 12 ns and with different CRTs of 100-900 ps FWHM involving 50 ps FWHM increments using the NEMA scatter phantom. Strong evidence supporting robustness of the simulations was found as observed in the good agreement between measured and simulated data for the cases of estimating axial sensitivity, axial and transaxial detection position, gamma non-collinearity angle distribution and positron annihilation distance. In the non-TOF context, the results show that the random event rate can be reduced by using narrower coincidence timing window widths, demonstrating considerable enhancements in the peak noise equivalent count rate (NECR) performance. The peak NECR had increased by {approx}50% when utilizing the coincidence window width of 4 ns. At the same time, utilization of TOF information resulted in improved NECR and SNR with the dramatic reduction of random coincidences as a function of CRT. For example, with CRT of 500 ps FWHM, a factor of 2.3 reduction in random rates, factor of 1.5 increase in NECR and factor of 2.1 improvement in SNR is

  12. Paul Lecoq assembles a read head made with special crystals for a PET (positron emission tomography) scanner. He is the initiator of the Crystal Clear collaboration, which aims to transfer crystals developed at CERN to applications in medical imaging.

    CERN Multimedia

    Maximilien Brice

    2004-01-01

    Paul Lecoq assembles a read head made with special crystals for a PET (positron emission tomography) scanner. He is the initiator of the Crystal Clear collaboration, which aims to transfer crystals developed at CERN to applications in medical imaging.

  13. Characterization of a high resolution and high sensitivity pre-clinical PET scanner with 3D event reconstruction

    CERN Document Server

    Rissi, M; Bolle, E; Dorholt, O; Hines, K E; Rohne, O; Skretting, A; Stapnes, S; Volgyes, D

    2012-01-01

    COMPET is a preclinical PET scanner aiming towards a high sensitivity, a high resolution and MRI compatibility by implementing a novel detector geometry. In this approach, long scintillating LYSO crystals are used to absorb the gamma-rays. To determine the point of interaction (P01) between gamma-ray and crystal, the light exiting the crystals on one of the long sides is collected with wavelength shifters (WLS) perpendicularly arranged to the crystals. This concept has two main advantages: (1) The parallax error is reduced to a minimum and is equal for the whole field of view (FOV). (2) The P01 and its energy deposit is known in all three dimension with a high resolution, allowing for the reconstruction of Compton scattered gamma-rays. Point (1) leads to a uniform point source resolution (PSR) distribution over the whole FOV, and also allows to place the detector close to the object being imaged. Both points (1) and (2) lead to an increased sensitivity and allow for both high resolution and sensitivity at the...

  14. Semi-quantitative and simulation analyses of effects of {gamma} rays on determination of calibration factors of PET scanners with point-like {sup 22}Na sources

    Energy Technology Data Exchange (ETDEWEB)

    Hasegawa, Tomoyuki [School of Allied Health Sciences, Kitasato University, 1-15-1, Kitasato, Minamiku, Sagamihara, Kanagawa, 252-0373 (Japan); Sato, Yasushi [National Institute of Advanced Industrial Science and Technology, 1-1-1, Umezono, Tsukuba, Ibaraki, 305-8568 (Japan); Oda, Keiichi [Tokyo Metropolitan Institute of Gerontology, 1-1, Nakamachi, Itabashi, Tokyo, 173-0022 (Japan); Wada, Yasuhiro [RIKEN Center for Molecular Imaging Science, 6-7-3, Minamimachi, Minatoshima, Chuo, Kobe, Hyogo, 650-0047 (Japan); Murayama, Hideo [National Institute of Radiological Sciences, 4-9-1, Anagawa, Inage, Chiba, 263-8555 (Japan); Yamada, Takahiro, E-mail: hasegawa@kitasato-u.ac.jp [Japan Radioisotope Association, 2-28-45, Komagome, Bunkyo-ku, Tokyo, 113-8941 (Japan)

    2011-09-21

    The uncertainty of radioactivity concentrations measured with positron emission tomography (PET) scanners ultimately depends on the uncertainty of the calibration factors. A new practical calibration scheme using point-like {sup 22}Na radioactive sources has been developed. The purpose of this study is to theoretically investigate the effects of the associated 1.275 MeV {gamma} rays on the calibration factors. The physical processes affecting the coincidence data were categorized in order to derive approximate semi-quantitative formulae. Assuming the design parameters of some typical commercial PET scanners, the effects of the {gamma} rays as relative deviations in the calibration factors were evaluated by semi-quantitative formulae and a Monte Carlo simulation. The relative deviations in the calibration factors were less than 4%, depending on the details of the PET scanners. The event losses due to rejecting multiple coincidence events of scattered {gamma} rays had the strongest effect. The results from the semi-quantitative formulae and the Monte Carlo simulation were consistent and were useful in understanding the underlying mechanisms. The deviations are considered small enough to correct on the basis of precise Monte Carlo simulation. This study thus offers an important theoretical basis for the validity of the calibration method using point-like {sup 22}Na radioactive sources.

  15. An analog signal processing ASIC for a small animal LSO-APD PET tomograph

    International Nuclear Information System (INIS)

    Spanoudaki, V.Ch.; McElroy, D.P.; Ziegler, S.I.

    2006-01-01

    MADPET-II is a small animal PET scanner currently under development that provides individual readout for each one of its 1152 LSO-APD electronic channels. In order to process such a large number of channels individually, the analog signal processing electronics are fully integrated into monolithic chips. Each chip contains four independent differential receivers, shaping amplifiers, peak hold detectors and non-delay line constant-fraction discriminators (CFDs). The CFDs use a high-pass CR circuit rather than the conventional delay line to generate a bipolar pulse. The performance of the chip has been tested for walk, jitter and pulse height linearity by studying the peak detector and the CFD signals, and has been optimized by adjusting the corresponding bias currents so as to maximize the signal-to-noise ratio and to minimize the walk of the CFD output (trigger). The response of the peak detector to different input signal amplitudes is linear (R 2 =0.99945+/-0.00002). The walk performance of the CFD can be adjusted by changing the offset of the CR high-pass filter output signal, and can be minimized to approximately 2ns over a 5:1 input amplitude dynamic range

  16. Gated listmode acquisition with the QuadHIDAC animal PET to image mouse hearts

    International Nuclear Information System (INIS)

    Schaefers, K.P.; Lang, N.; Stegger, L.; Schober, O.; Schaefers, M.

    2006-01-01

    Purpose: the aim of this study was to develop ECG and respiratory gating in combination with listmode acquisition for the quadHIDAC small-animal PET scanner. Methods: ECG and respiratory gating was realized with the help of an external trigger device (BioVET) synchronized with the listmode acquisition. Listmode data of a mouse acquisition (injected with 6.5 MBq of 18 F-FDG) were sorted according to three different gating definitions: 12 cardiac gates, 8 respiratory gates and a combination of 8 cardiac and 8 respiratory gates. Images were reconstructed with filtered back-projection (ramp filter), and parameters like left ventricular wall thickness (WT), wall-to-wall separation (WS) and blood to myocardium activity ratios (BMR) were calculated. Results: cardiac gated images show improvement of all parameters (WT 2.6 mm, WS 4.1 mm, BRM 2.3) in diastole compared to ungated images (WT 3.0 mm, WS 3.4 mm, BMR 1.3). Respiratory gating had little effect on calculated parameters. Conclusion: ECG gating with the quadHIDAC can improve myocardial image quality in mice. This could have a major impact on the calculation of an image-derived input function for kinetic modelling. (orig.)

  17. Development of a SiPM-based PET imaging system for small animals

    International Nuclear Information System (INIS)

    Lu, Yanye; Yang, Kun; Zhou, Kedi; Zhang, Qiushi; Pang, Bo; Ren, Qiushi

    2014-01-01

    Advances in small animal positron emission tomography (PET) imaging have been accelerated by many new technologies such as the successful incorporation of silicon photomultiplier (SiPM). In this paper, we have developed a compact, lightweight PET imaging system that is based on SiPM detectors for small animals imaging, which could be integrated into a multi-modality imaging system. This PET imaging system consists of a stationary detector gantry, a motor-controlled animal bed module, electronics modules, and power supply modules. The PET detector, which was designed as a multi-slice circular ring geometry of 27 discrete block detectors, is composed of a cerium doped lutetium–yttrium oxyorthosilicate (LYSO) scintillation crystal and SiPM arrays. The system has a 60 mm transaxial field of view (FOV) and a 26 mm axial FOV. Performance tests (e.g. spatial resolution, energy resolution, and sensitivity) and phantom and animal imaging studies were performed to evaluate the imaging performance of the PET imaging system. The performance tests and animal imaging results demonstrate the feasibility of an animal PET system based on SiPM detectors and indicate that SiPM detectors can be promising photodetectors in animal PET instrumentation development

  18. The Benefit of Pets and Animal-Assisted Therapy to the Health of Older Individuals

    Directory of Open Access Journals (Sweden)

    E. Paul Cherniack

    2014-01-01

    Full Text Available Many studies utilizing dogs, cats, birds, fish, and robotic simulations of animals have tried to ascertain the health benefits of pet ownership or animal-assisted therapy in the elderly. Several small unblinded investigations outlined improvements in behavior in demented persons given treatment in the presence of animals. Studies piloting the use of animals in the treatment of depression and schizophrenia have yielded mixed results. Animals may provide intangible benefits to the mental health of older persons, such as relief social isolation and boredom, but these have not been formally studied. Several investigations of the effect of pets on physical health suggest animals can lower blood pressure, and dog walkers partake in more physical activity. Dog walking, in epidemiological studies and few preliminary trials, is associated with lower complication risk among patients with cardiovascular disease. Pets may also have harms: they may be expensive to care for, and their owners are more likely to fall. Theoretically, zoonotic infections and bites can occur, but how often this occurs in the context of pet ownership or animal-assisted therapy is unknown. Despite the poor methodological quality of pet research after decades of study, pet ownership and animal-assisted therapy are likely to continue due to positive subjective feelings many people have toward animals.

  19. The benefit of pets and animal-assisted therapy to the health of older individuals.

    Science.gov (United States)

    Cherniack, E Paul; Cherniack, Ariella R

    2014-01-01

    Many studies utilizing dogs, cats, birds, fish, and robotic simulations of animals have tried to ascertain the health benefits of pet ownership or animal-assisted therapy in the elderly. Several small unblinded investigations outlined improvements in behavior in demented persons given treatment in the presence of animals. Studies piloting the use of animals in the treatment of depression and schizophrenia have yielded mixed results. Animals may provide intangible benefits to the mental health of older persons, such as relief social isolation and boredom, but these have not been formally studied. Several investigations of the effect of pets on physical health suggest animals can lower blood pressure, and dog walkers partake in more physical activity. Dog walking, in epidemiological studies and few preliminary trials, is associated with lower complication risk among patients with cardiovascular disease. Pets may also have harms: they may be expensive to care for, and their owners are more likely to fall. Theoretically, zoonotic infections and bites can occur, but how often this occurs in the context of pet ownership or animal-assisted therapy is unknown. Despite the poor methodological quality of pet research after decades of study, pet ownership and animal-assisted therapy are likely to continue due to positive subjective feelings many people have toward animals.

  20. Deep Inspiration Breath Hold [(18)F]FDG PET-CT on 4-rings scanners in evaluating lung lesions: evidences from a phantom and a clinical study.

    Science.gov (United States)

    Caobelli, Federico; Puta, Erinda; Kaiser, Stefano Ren; Massetti, Valentina; Andreoli, Michela; Mostarda, Angelica; Soffientini, Alberto; Pizzocaro, Claudio; Guerra, Ugo Paolo

    2014-01-01

    To investigate the clinical feasibility of a Deep Inspiration Breath Hold (DIBH) (18)F-FDG PET-CT acquisition in apnea and compare the results obtained between these acts of acquisition in apnea and in Free Breathing in the evaluation of lung lesions. A pre-clinical phantom study was performed to evaluate the shortest simulated DIBH time according to the minimum detectable lesion that can be detected by our ultrasound scanner. This study was conducted by changing acquisition time and sphere-to-background activity ratio values and by using radioactivity densities similar to those generally found in clinical examinations. In the clinical study, 25 patients with pulmonary lesions underwent a standard whole body (18)F-FDG PET-CT scan in free breathing followed by a 20s single thorax acquisition PET/CT in DIBH acquisition. The phantom study indicated that a 20-s acquisition time provides an accurate evaluation of smallest sphere shaped lesions. In the clinical study, PET-CT scans obtained in DIBH studies showed a significant reduction of misalignment between the PET and CT scan images and an increase of SUVmax compared to free breathing acquisitions. A correlation between the %BH-index and lesion displacement between PET and CT images in FB acquisition was demonstrated, significantly higher for lesions with a displacement>8mm. The single 20s acquisition of DIBH PET-CT is a feasible technique for lung lesion detection in the clinical setting. It only requires a minor increase in examination time without special patient training. 20s DIBH scan provided a more precise measurement of SUVmax, especially for lesions in the lower lung lobes which usually show greater displacement between PET and CT scan images in FB acquisition. Copyright © 2013 Elsevier España, S.L. and SEMNIM. All rights reserved.

  1. Future of keeping pet reptiles and amphibians: towards integrating animal welfare, human health and environmental sustainability.

    Science.gov (United States)

    Pasmans, Frank; Bogaerts, Serge; Braeckman, Johan; Cunningham, Andrew A; Hellebuyck, Tom; Griffiths, Richard A; Sparreboom, Max; Schmidt, Benedikt R; Martel, An

    2017-10-28

    The keeping of exotic pets is currently under debate and governments of several countries are increasingly exploring the regulation, or even the banning, of exotic pet keeping. Major concerns are issues of public health and safety, animal welfare and biodiversity conservation. The keeping of reptiles and amphibians in captivity encompasses all the potential issues identified with keeping exotic pets, and many of those relating to traditional domestic pets. Within the context of risks posed by pets in general, the authors argue for the responsible and sustainable keeping of reptile and amphibian pets by private persons, based on scientific evidence and on the authors' own expertise (veterinary medicine, captive husbandry, conservation biology). © British Veterinary Association (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  2. A microPET/CT system for invivo small animal imaging

    Energy Technology Data Exchange (ETDEWEB)

    Liang, H [Department of Biomedical Engineering, University of California, Davis, GBSF Building, 451 East Health Sciences Drive, Davis, CA 95616 (United States); Yang, Y [Department of Biomedical Engineering, University of California, Davis, GBSF Building, 451 East Health Sciences Drive, Davis, CA 95616 (United States); Yang, K [Department of Radiology, UC Davis Medical Center, 4701 X Street, X-ray Imaging Laboratory, Sacramento, CA 95817 (United States); Wu, Y [Department of Biomedical Engineering, University of California, Davis, GBSF Building, 451 East Health Sciences Drive, Davis, CA 95616 (United States); Boone, J M [Department of Biomedical Engineering, University of California, Davis, GBSF Building, 451 East Health Sciences Drive, Davis, CA 95616 (United States); Cherry, S R [Department of Biomedical Engineering, University of California, Davis, GBSF Building, 451 East Health Sciences Drive, Davis, CA 95616 (United States)

    2007-07-07

    A microCT scanner was designed, fabricated and integrated with a previously reported microPET II scanner (Tai et al 2003 Phys. Med. Biol. 48 1519, Yang et al 2004 Phys. Med. Biol. 49 2527), forming a dual modality system for in vivo anatomic and molecular imaging of the mouse. The system was designed to achieve high-spatial-resolution and high-sensitivity PET images with adequate CT image quality for anatomic localization and attenuation correction with low x-ray dose. The system also has relatively high throughput for screening, and a flexible gantry and user interface. X-rays were produced by a 50 kVp, 1.5 mA fixed tungsten anode tube, with a focal spot size of 70 {mu}m. The detector was a 5 x 5 cm{sup 2} photodiode detector incorporating 48 {mu}m pixels on a CMOS array and a fast gadolinium oxysulfide (GOS) intensifying screen. The microCT system has a flexible C-arm gantry design with adjustable detector positioning, which acquires CT projection images around the common microPET/CT bed. The design and the initial characterization of the microCT system is described, and images of the first mouse scans with microPET/CT scanning protocols are shown.

  3. A microPET/CT system for invivo small animal imaging

    Science.gov (United States)

    Liang, H.; Yang, Y.; Yang, K.; Wu, Y.; Boone, J. M.; Cherry, S. R.

    2007-07-01

    A microCT scanner was designed, fabricated and integrated with a previously reported microPET II scanner (Tai et al 2003 Phys. Med. Biol. 48 1519, Yang et al 2004 Phys. Med. Biol. 49 2527), forming a dual modality system for in vivo anatomic and molecular imaging of the mouse. The system was designed to achieve high-spatial-resolution and high-sensitivity PET images with adequate CT image quality for anatomic localization and attenuation correction with low x-ray dose. The system also has relatively high throughput for screening, and a flexible gantry and user interface. X-rays were produced by a 50 kVp, 1.5 mA fixed tungsten anode tube, with a focal spot size of 70 µm. The detector was a 5 × 5 cm2 photodiode detector incorporating 48 µm pixels on a CMOS array and a fast gadolinium oxysulfide (GOS) intensifying screen. The microCT system has a flexible C-arm gantry design with adjustable detector positioning, which acquires CT projection images around the common microPET/CT bed. The design and the initial characterization of the microCT system is described, and images of the first mouse scans with microPET/CT scanning protocols are shown.

  4. The Benefit of Pets and Animal-Assisted Therapy to the Health of Older Individuals

    OpenAIRE

    E. Paul Cherniack; Ariella R. Cherniack

    2014-01-01

    Many studies utilizing dogs, cats, birds, fish, and robotic simulations of animals have tried to ascertain the health benefits of pet ownership or animal-assisted therapy in the elderly. Several small unblinded investigations outlined improvements in behavior in demented persons given treatment in the presence of animals. Studies piloting the use of animals in the treatment of depression and schizophrenia have yielded mixed results. Animals may provide intangible benefits to the mental health...

  5. 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.

  6. Healthy animals, healthy people: zoonosis risk from animal contact in pet shops, a systematic review of the literature.

    Science.gov (United States)

    Halsby, Kate D; Walsh, Amanda L; Campbell, Colin; Hewitt, Kirsty; Morgan, Dilys

    2014-01-01

    Around 67 million pets are owned by households in the United Kingdom, and an increasing number of these are exotic animals. Approximately a third of pets are purchased through retail outlets or direct from breeders. A wide range of infections can be associated with companion animals. This study uses a systematic literature review to describe the transmission of zoonotic disease in humans associated with a pet shop or other location selling pets (incidents of rabies tracebacks and zoonoses from pet food were excluded). PubMed and EMBASE. Fifty seven separate case reports or incidents were described in the 82 papers that were identified by the systematic review. Summary information on each incident is included in this manuscript. The infections include bacterial, viral and fungal diseases and range in severity from mild to life threatening. Infections associated with birds and rodents were the most commonly reported. Over half of the reports describe incidents in the Americas, and three of these were outbreaks involving more than 50 cases. Many of the incidents identified relate to infections in pet shop employees. This review may have been subject to publication bias, where unusual and unexpected zoonotic infections may be over-represented in peer-reviewed publications. It was also restricted to English-language articles so that pathogens that are more common in non-Western countries, or in more exotic animals not common in Europe and the Americas, may have been under-represented. A wide spectrum of zoonotic infections are acquired from pet shops. Salmonellosis and psittacosis were the most commonly documented diseases, however more unusual infections such as tularemia also appeared in the review. Given their potential to spread zoonotic infection, it is important that pet shops act to minimise the risk as far as possible.

  7. Jet set pets: examining the zoonosis risk in animal import and travel across the European Union

    Directory of Open Access Journals (Sweden)

    Fooks AR

    2014-12-01

    Full Text Available Anthony R Fooks,1,2 Nicholas Johnson1 1Wildlife Zoonoses and Vector-Borne Diseases Research Group, Animal and Plant Health Agency, Addlestone, Surrey, 2Department of Clinical Infection, University of Liverpool, Liverpool, UK Abstract: Ownership of companion animals or pets is popular throughout the world. Unfortunately, such animals are susceptible to and potential reservoirs of zoonotic pathogens. Close proximity to and contact with pets can lead to human infections. The distribution of zoonotic diseases associated with companion animals such as dogs and cats is not uniform around the world, and moving animals between regions, countries, and continents carries with it the risk of relocating the pathogens they might harbor. Critical among these zoonotic diseases are rabies, echinococcosis, and leishmania. In addition, the protozoan parasites, Toxoplasma gondii and Giardia duodenalis, are also significant agents for human disease of pet origin. Considerable effort is applied to controlling movements of companion animals, particularly dogs, into the European Union. However, free movement of people and their pets within the European Union is a risk factor for the translocation of diseases and their vectors. This review considers the current distribution of some of these diseases, the risks associated with pet travel, and the controls implemented within Europe to prevent the free movement of zoonotic pathogens. Keywords: zoonosis, companion animal, rabies, alveolar echinococcosis, leishmania

  8. The 'pet effect'--health related aspects of companion animal ownership.

    Science.gov (United States)

    Smith, Bradley

    2012-06-01

    Numerous studies indicate that companion animal ownership is associated with a range of physical, psychological and social health advantages, yet there is little discussion around the practical ways to integrate companion animals into healthcare and health promotion. This article provides a brief summary of the health related aspects of companion animal ownership, and suggests ways in which general practitioners can integrate discussions regarding pet interaction into everyday practice. The subject of companion animals can be a catalyst for engaging patients in discussions about preventive health. General practitioners are in an ideal position to understand the human-pet dynamic, and to encourage patients to interact with their pets to improve their own health and wellbeing. Questions relating to companion animals could be asked during routine social history taking. The knowledge gained from this approach may facilitate more tailored patient management and personalised lifestyle recommendations.

  9. Experimental Characterization of Monolithic-Crystal Small Animal PET Detectors Read Out by APD Arrays

    Science.gov (United States)

    Maas, M. C.; van der Laan, D. J.; Schaart, D. R.; Huizenga, J.; Brouwer, J. C.; Bruyndonckx, P.; Leonard, S.; Lemaitre, C.; van Eijk, C. W. E.

    2006-06-01

    Minimizing dead space is one way to increase the detection efficiency of small-animal PET scanners. By using monolithic scintillator crystals (e.g., 20 mm/spl times/10 mm/spl times/10 mm LSO), loss of efficiency due to inter-crystal reflective material is minimized. Readout of such crystals can be performed by means of one or more avalanche photo-diode (APD) arrays optically coupled to the crystal. The entry point of a gamma photon on the crystal surface can be estimated from the measured distribution of the scintillation light over the APD array(s). By estimating the entry point, correction for the depth-of-interaction (DOI) is automatically provided. We are studying the feasibility of such detector modules. To this end, a 64-channel test setup has been developed. Experiments to determine the effect on the spatial resolution of crystal surface finish and detector geometry have been carried out. The first results of these experiments are presented and compared to simulation results. The crystal surface finish has only a small influence on the spatial resolution. The spatial resolution of 20 mm/spl times/10 mm/spl times/10 mm detectors is significantly better when read out on the front side than when read out on the back side. With a 20 mm/spl times/10 mm/spl times/20 mm crystal coupled to two APD arrays, a very small resolution degradation of only /spl sim/0.2 mm is observed for an incidence angle of 30/spl deg/ compared to normal incidence.

  10. Senior Pets

    Science.gov (United States)

    ... Care Animal Welfare Veterinary Careers Public Health Senior Pets Veterinarians Get the Senior Pets client information brochure . ... healthier life for your pet. When does a pet become “old”? It varies, but cats and small ...

  11. Why Did You Choose This Pet?: Adopters and Pet Selection Preferences in Five Animal Shelters in the United States

    Science.gov (United States)

    Weiss, Emily; Miller, Katherine; Mohan-Gibbons, Heather; Vela, Carla

    2012-01-01

    Simple Summary This study examined reasons why adopters chose their pet in an animal shelter, what behaviors were first exhibited by the pet to the adopter, what information was important during their selection process, and the relative importance of seeing the animals’ behavior in various contexts. Abstract Responses from an adopter survey (n = 1,491) determined reasons for pet selection, type of information received by the adopter, and the context in which the animal’s behavior was observed. Appearance of the animal, social behavior with adopter, and personality were the top reasons for adoption across species and age groups. Most adopters stated that information about the animal from a staff member or volunteer was more important than information on cage cards, and health and behavior information was particularly important. Adopters found greater importance in interacting with the animal rather than viewing it in its kennel. The results of this study can be used by shelters to create better adoption matches, prioritize shelter resources and staff training, and potentially increase adoptions. Additionally, some simple training techniques are suggested to facilitate adopter-friendly behaviors from sheltered dogs and cats. PMID:26486914

  12. Application of inulin-type fructans in animal feed and pet food

    NARCIS (Netherlands)

    Verdonk, J.M.A.J.; Shim, S.B.; Leeuwen, van P.; Verstegen, M.W.A.

    2005-01-01

    The inulin-type fructans are non-digestible oligosaccharides that are fermented in the gastrointestinal tract of farm animals and pets. This review focuses on the various effects of inulin-type fructans in pigs, poultry, calves and companion animals. Effects of the inulin-type fructans on gut

  13. Effects of Keeping Animals as Pets on Children's Concepts of Vertebrates and Invertebrates

    Science.gov (United States)

    Prokop, Pavol; Prokop, Matej; Tunnicliffe, Sue D.

    2008-01-01

    Looking after pets provides several benefits in terms of children's social interactions, and factual and conceptual knowledge about these animals. In this study we investigated effects of rearing experiences on children's factual knowledge and alternative conceptions about animals. Data obtained from 1,541 children and 7,705 drawings showed very…

  14. Investigation into the animal species contents of popular wet pet foods.

    Science.gov (United States)

    Maine, Isabella R; Atterbury, Robert; Chang, Kin-Chow

    2015-03-10

    The use of the generic term "meat and animal derivatives" in declared ingredient lists of pet foods in the European Union is virtually universal. In the wake of the 2013 "horse meat scandal" in the human food chain, we examined the presence and authenticity of animal sources (cow, chicken, pig and horse) of proteins in a range of popular wet pet foods in the United Kingdom. Seventeen leading dog and cat foods were sampled for the relative presence of DNA from each of the four animal species by quantitative real-time polymerase chain reaction. No horse DNA was detected. However, there was detection at substantial levels of unspecified animal species in most products tested. In 14 out of 17 samples, bovine, porcine and chicken DNA were found in various proportions and combinations but were not explicitly identified on the product labels. Of the 7 products with prominent headline descriptions containing the term "with beef", only 2 were found to contain more bovine DNA (>50%) than pig and chicken DNA combined. There is a need for the pet food industry to show greater transparency to customers in the disclosure of the types of animal proteins (animal species and tissue types) in their products. Full disclosure of animal contents will (a) allow more informed choices to be made on purchases which are particularly important for pets with food allergies, (b) reduce the risk of product misinterpretation by shoppers, and (c) avoid potential religious concerns.

  15. On the accuracy and reproducibility of a novel probabilistic atlas-based generation for calculation of head attenuation maps on integrated PET/MR scanners

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Kevin T. [Massachusetts General Hospital and Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Charlestown, MA (United States); Massachusetts Institute of Technology, Division of Health Sciences and Technology, Cambridge, MA (United States); Izquierdo-Garcia, David; Catana, Ciprian [Massachusetts General Hospital and Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Charlestown, MA (United States); Poynton, Clare B. [Massachusetts General Hospital and Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Charlestown, MA (United States); Massachusetts General Hospital, Department of Psychiatry, Boston, MA (United States); University of California, San Francisco, Department of Radiology and Biomedical Imaging, San Francisco, CA (United States); Chonde, Daniel B. [Massachusetts General Hospital and Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Charlestown, MA (United States); Harvard University, Program in Biophysics, Cambridge, MA (United States)

    2017-03-15

    To propose an MR-based method for generating continuous-valued head attenuation maps and to assess its accuracy and reproducibility. Demonstrating that novel MR-based photon attenuation correction methods are both accurate and reproducible is essential prior to using them routinely in research and clinical studies on integrated PET/MR scanners. Continuous-valued linear attenuation coefficient maps (''μ-maps'') were generated by combining atlases that provided the prior probability of voxel positions belonging to a certain tissue class (air, soft tissue, or bone) and an MR intensity-based likelihood classifier to produce posterior probability maps of tissue classes. These probabilities were used as weights to generate the μ-maps. The accuracy of this probabilistic atlas-based continuous-valued μ-map (''PAC-map'') generation method was assessed by calculating the voxel-wise absolute relative change (RC) between the MR-based and scaled CT-based attenuation-corrected PET images. To assess reproducibility, we performed pair-wise comparisons of the RC values obtained from the PET images reconstructed using the μ-maps generated from the data acquired at three time points. The proposed method produced continuous-valued μ-maps that qualitatively reflected the variable anatomy in patients with brain tumor and agreed well with the scaled CT-based μ-maps. The absolute RC comparing the resulting PET volumes was 1.76 ± 2.33 %, quantitatively demonstrating that the method is accurate. Additionally, we also showed that the method is highly reproducible, the mean RC value for the PET images reconstructed using the μ-maps obtained at the three visits being 0.65 ± 0.95 %. Accurate and highly reproducible continuous-valued head μ-maps can be generated from MR data using a probabilistic atlas-based approach. (orig.)

  16. 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.

  17. A Systematic Review and Meta-Analysis of the Campylobacter spp. Prevalence and Concentration in Household Pets and Petting Zoo Animals for Use in Exposure Assessments.

    Science.gov (United States)

    Pintar, Katarina D M; Christidis, Tanya; Thomas, M Kate; Anderson, Maureen; Nesbitt, Andrea; Keithlin, Jessica; Marshall, Barbara; Pollari, Frank

    2015-01-01

    Animal contact is a potential transmission route for campylobacteriosis, and both domestic household pet and petting zoo exposures have been identified as potential sources of exposure. Research has typically focussed on the prevalence, concentration, and transmission of zoonoses from farm animals to humans, yet there are gaps in our understanding of these factors among animals in contact with the public who don't live on or visit farms. This study aims to quantify, through a systematic review and meta-analysis, the prevalence and concentration of Campylobacter carriage in household pets and petting zoo animals. Four databases were accessed for the systematic review (PubMed, CAB direct, ProQuest, and Web of Science) for papers published in English from 1992-2012, and studies were included if they examined the animal population of interest, assessed prevalence or concentration with fecal, hair coat, oral, or urine exposure routes (although only articles that examined fecal routes were found), and if the research was based in Canada, USA, Europe, Australia, and New Zealand. Studies were reviewed for qualitative synthesis and meta-analysis by two reviewers, compiled into a database, and relevant studies were used to create a weighted mean prevalence value. There were insufficient data to run a meta-analysis of concentration values, a noted study limitation. The mean prevalence of Campylobacter in petting zoo animals is 6.5% based on 7 studies, and in household pets the mean is 24.7% based on 34 studies. Our estimated concentration values were: 7.65x103cfu/g for petting zoo animals, and 2.9x105cfu/g for household pets. These results indicate that Campylobacter prevalence and concentration are lower in petting zoo animals compared with household pets and that both of these animal sources have a lower prevalence compared with farm animals that do not come into contact with the public. There is a lack of studies on Campylobacter in petting zoos and/or fair animals in

  18. The impact of image reconstruction settings on 18F-FDG PET radiomic features. Multi-scanner phantom and patient studies

    Energy Technology Data Exchange (ETDEWEB)

    Shiri, Isaac; Abdollahi, Hamid [Iran University of Medical Sciences, Department of Medical Physics, School of Medicine, Tehran (Iran, Islamic Republic of); Rahmim, Arman [Johns Hopkins University, Department of Radiology, Baltimore, MD (United States); Johns Hopkins University, Department of Electrical and Computer Engineering, Baltimore, MD (United States); Ghaffarian, Pardis [Shahid Beheshti University of Medical Sciences, Chronic Respiratory Diseases Research Center, National Research Institute of Tuberculosis and Lung Diseases (NRITLD), Tehran (Iran, Islamic Republic of); Shahid Beheshti University of Medical Sciences, PET/CT and Cyclotron Center, Masih Daneshvari Hospital, Tehran (Iran, Islamic Republic of); Geramifar, Parham [Tehran University of Medical Sciences, Research Center for Nuclear Medicine, Shariati Hospital, Tehran (Iran, Islamic Republic of); Bitarafan-Rajabi, Ahmad [Iran University of Medical Sciences, Department of Medical Physics, School of Medicine, Tehran (Iran, Islamic Republic of); Iran University of Medical Sciences, Department of Nuclear Medicine, Rajaei Cardiovascular, Medical and Research Center, Tehran (Iran, Islamic Republic of)

    2017-11-15

    The purpose of this study was to investigate the robustness of different PET/CT image radiomic features over a wide range of different reconstruction settings. Phantom and patient studies were conducted, including two PET/CT scanners. Different reconstruction algorithms and parameters including number of sub-iterations, number of subsets, full width at half maximum (FWHM) of Gaussian filter, scan time per bed position and matrix size were studied. Lesions were delineated and one hundred radiomic features were extracted. All radiomics features were categorized based on coefficient of variation (COV). Forty seven percent features showed COV ≤ 5% and 10% of which showed COV > 20%. All geometry based, 44% and 41% of intensity based and texture based features were found as robust respectively. In regard to matrix size, 56% and 6% of all features were found non-robust (COV > 20%) and robust (COV ≤ 5%) respectively. Variability and robustness of PET/CT image radiomics in advanced reconstruction settings is feature-dependent, and different settings have different effects on different features. Radiomic features with low COV can be considered as good candidates for reproducible tumour quantification in multi-center studies. (orig.)

  19. 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...

  20. Why Did You Choose This Pet?: Adopters and Pet Selection Preferences in Five Animal Shelters in the United States

    Directory of Open Access Journals (Sweden)

    Carla Vela

    2012-04-01

    Full Text Available Responses from an adopter survey (n = 1,491 determined reasons for pet selection, type of information received by the adopter, and the context in which the animal’s behavior was observed. Appearance of the animal, social behavior with adopter, and personality were the top reasons for adoption across species and age groups. Most adopters stated that information about the animal from a staff member or volunteer was more important than information on cage cards, and health and behavior information was particularly important. Adopters found greater importance in interacting with the animal rather than viewing it in its kennel. The results of this study can be used by shelters to create better adoption matches, prioritize shelter resources and staff training, and potentially increase adoptions. Additionally, some simple training techniques are suggested to facilitate adopter-friendly behaviors from sheltered dogs and cats.

  1. 78 FR 34565 - Irradiation in the Production, Processing, and Handling of Animal Feed and Pet Food; Electron...

    Science.gov (United States)

    2013-06-10

    .... FDA-2012-F-0178] Irradiation in the Production, Processing, and Handling of Animal Feed and Pet Food; Electron Beam and X-Ray Sources for Irradiation of Poultry Feed and Poultry Feed Ingredients; Correction... Administration (FDA) is correcting a document amending the regulations for irradiation of animal feed and pet...

  2. 78 FR 27303 - Irradiation in the Production, Processing, and Handling of Animal Feed and Pet Food; Electron...

    Science.gov (United States)

    2013-05-10

    ...-0178] Irradiation in the Production, Processing, and Handling of Animal Feed and Pet Food; Electron Beam and X-Ray Sources for Irradiation of Poultry Feed and Poultry Feed Ingredients AGENCY: Food and... amending the regulations for irradiation of animal feed and pet food to provide for the safe use of...

  3. Development of an ultrahigh resolution Si-PM based PET system for small animals

    Science.gov (United States)

    Yamamoto, Seiichi; Watabe, Hiroshi; Kanai, Yasukazu; Watabe, Tadashi; Kato, Katsuhiko; Hatazawa, Jun

    2013-11-01

    Since a high resolution PET system is needed for small animal imaging, especially for mouse studies, we developed a new small animal PET system that decreased the size of the scintillators to less than 1 mm. Our developed PET system used 0.5 × 0.7 × 5 mm3 LYSO pixels arranged in an 11 × 13 matrix to form a block with a 0.1 mm BaSO4 reflector between the pixels. Two LYSO blocks were optically coupled to two optical fiber based angled image guides. These LYSO blocks and image guides were coupled to a Si-PM array (Hamamatsu MPPC S11064-050P) to form a block detector. Eight block detectors (16 LYSO blocks) were arranged in a 34 mm inner diameter ring to form a small animal PET system. The block detector showed good separation for the 22 × 13 LYSO pixels in the two-dimensional position histogram. The energy resolution was 20% full-with at half-maximum (FWHM) for 511 keV gamma photons. The transaxial resolution reconstructed by filtered backprojection was 0.71 to 0.75 mm FWHM and the axial resolution was 0.70 mm. The point source sensitivity was 0.24% at the central axial field-of-view. High resolution mouse images were obtained using our PET system. The developed ultrahigh resolution PET system showed attractive images for small animal studies and has a potential to provide new findings in molecular imaging researches.

  4. Development of an ultrahigh resolution Si-PM based PET system for small animals

    International Nuclear Information System (INIS)

    Yamamoto, Seiichi; Kato, Katsuhiko; Watabe, Hiroshi; Kanai, Yasukazu; Watabe, Tadashi; Hatazawa, Jun

    2013-01-01

    Since a high resolution PET system is needed for small animal imaging, especially for mouse studies, we developed a new small animal PET system that decreased the size of the scintillators to less than 1 mm. Our developed PET system used 0.5 × 0.7 × 5 mm 3 LYSO pixels arranged in an 11 × 13 matrix to form a block with a 0.1 mm BaSO 4 reflector between the pixels. Two LYSO blocks were optically coupled to two optical fiber based angled image guides. These LYSO blocks and image guides were coupled to a Si-PM array (Hamamatsu MPPC S11064–050P) to form a block detector. Eight block detectors (16 LYSO blocks) were arranged in a 34 mm inner diameter ring to form a small animal PET system. The block detector showed good separation for the 22 × 13 LYSO pixels in the two-dimensional position histogram. The energy resolution was 20% full-with at half-maximum (FWHM) for 511 keV gamma photons. The transaxial resolution reconstructed by filtered backprojection was 0.71 to 0.75 mm FWHM and the axial resolution was 0.70 mm. The point source sensitivity was 0.24% at the central axial field-of-view. High resolution mouse images were obtained using our PET system. The developed ultrahigh resolution PET system showed attractive images for small animal studies and has a potential to provide new findings in molecular imaging researches. (paper)

  5. FDG small animal PET permits early detection of malignant cells in a xenograft murine model

    International Nuclear Information System (INIS)

    Nanni, Cristina; Spinelli, Antonello; Trespidi, Silvia; Ambrosini, Valentina; Castellucci, Paolo; Farsad, Mohsen; Franchi, Roberto; Fanti, Stefano; Leo, Korinne di; Tonelli, Roberto; Pession, Andrea; Pettinato, Cinzia; Rubello, Domenico

    2007-01-01

    The administration of new anticancer drugs in animal models is the first step from in vitro to in vivo pre-clinical protocols. At this stage it is crucial to ensure that cells are in the logarithmic phase of growth and to avoid vascular impairment, which can cause inhomogeneous distribution of the drug within the tumour and thus lead to bias in the final analysis of efficacy. In subcutaneous xenograft murine models, positivity for cancer is visually recognisable 2-3 weeks after inoculation, when a certain amount of necrosis is usually already present. The aim of this study was to evaluate the accuracy of FDG small animal PET for the early detection of malignant masses in a xenograft murine model of human rhabdomyosarcoma. A second goal was to analyse the metabolic behaviour of this xenograft tumour over time. We studied 23 nude mice, in which 7 x 10 6 rhabdomyosarcoma cells (RH-30 cell line) were injected in the dorsal subcutaneous tissues. Each animal underwent four FDG PET scans (GE, eXplore Vista DR) under gas anaesthesia. The animals were studied 2, 5, 14 and 20 days after inoculation. We administered 20 MBq of FDG via the tail vein. Uptake time was 60 min, and acquisition time, 20 min. Images were reconstructed with OSEM 2D iterative reconstruction and the target to background ratio (TBR) was calculated for each tumour. Normal subcutaneous tissue had a TBR of 0.3. Necrosis was diagnosed when one or more cold areas were present within the mass. All the animals were sacrificed and histology was available to verify PET results. PET results were concordant with the findings of necropsy and histology in all cases. The incidence of the tumour was 69.6% (16/23 animals); seven animals did not develop a malignant mass. Ten of the 23 animals had a positive PET scan 2 days after inoculation. Nine of these ten animals developed a tumour; the remaining animal became negative, at the third scan. The positive predictive value of the early PET scan was 90% (9/10 animals

  6. Time over threshold readout method of SiPM based small animal PET detector

    International Nuclear Information System (INIS)

    Valastyan, I.; Gal, J.; Hegyesi, G.; Kalinka, G.; Nagy, F.; Kiraly, B.; Imrek, J.; Molnar, J.

    2012-01-01

    Complete text of publication follows. The aim of the work was to design a readout concept for silicon photomultiplier (SiPM) sensor array used in small animal PET scanner. The detector module consist of LYSO 35x35 scintillation crystals, 324 SiPM sensors (arranged in 2x2 blocks and those quads in a 9x9 configuration) and FPGA based readout electronics. The dimensions of the SiPM matrix are area: 48x48 mm 2 and the size of one SiPM sensor is 1.95x2.2 mm 2 . Due to the high dark current of the SiPM, conventional Anger based readout method does not provide sufficient crystal position maps. Digitizing the 324 SiPM channels is a straightforward way to obtain proper crystal position maps. However handling hundreds of analogue input channels and the required DSP resources cause large racks of data acquisition electronics. Therefore coding of the readout channels is required. Proposed readout method: The coding of the 324 SiPMs consists two steps: Step 1) Reduction of the channels from 324 to 36: Row column readout, SiPMs are connected to each other in column by column and row-by row, thus the required channels are 36. The dark current of 18 connected SiPMs is small in off for identifying pulses coming from scintillating events. Step 2) Reduction of the 18 rows and columns to 4 channels: Comparators were connected to each rows and columns, and the level was set above the level of dark noise. Therefore only few comparators are active when scintillation light enters in the tile. The output of the comparator rows and columns are divided to two parts using resistor chains. Then the outputs of the resistor chains are digitized by a 4 channel ADC. However instead of the Anger method, time over threshold (ToT) was used. Figure 1 shows the readout concept of the SiPM matrix. In order to validate the new method and optimize the front-end electronics of the detector, the analogue signals were digitized before the comparators using a CAEN DT5740 32 channel digitizer, then the

  7. Pulmonary emphysema diagnosis using a preclinical small-animal X-ray dark-field scanner

    Energy Technology Data Exchange (ETDEWEB)

    Yaroshenko, Andre; Bech, Martin; Tapfer, Arne; Velroyen, Astrid; Pfeiffer, Franz [Department of Physics, Technische Universitaet Muenchen (Germany); Meinel, Felix; Nikolaou, Konstantin; Reiser, Maximilian [Institute of Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Muenchen (Germany); Bohla, Alexander; Yildirim, Ali Oender; Eickelberg, Oliver [Institute of Lung Biology and Disease, Helmholtz Zentrum Muenchen (Germany)

    2013-07-01

    Pulmonary emphysema is one of the leading causes of morbidity and mortality worldwide that is difficult to detect using conventional x-ray radiographic methods. For emphysematous lungs with enlarged distal airspaces, x-ray scattering decreases and transmission increases, as has been demonstrated by the proof-of-principle experiments with brilliant x-rays from a synchrotron source. Therefore, combination of the transmission and dark-field signals leads to a novel diagnostic approach for pulmonary emphysema. In this study, images of excised murine lungs with pulmonary emphysema and control lungs were acquired using a compact phase- and dark-field scanner with a polychromatic source and a cone-beam geometry. The data analysis revealed a clear distinction between the two groups in the per-pixel scatter plot. The main difference was observed in the angle of the distribution to the vertical. The presented study reveals the high potential of the approach for the pulmonary emphysema diagnosis.

  8. 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

    by the optical motion tracking system) were selected from F-18-FDG scans acquired on a PET scanner. The motion was measured as the maximum displacement of the markers attached to the subject's head and was considered to be major if larger than 4 mm and minor if less than 2 mm. After allowing a 40- to 60-min...... uptake time after tracer injection, we acquired a 6-min transmission scan, followed by a 40-min emission list-mode scan. Each emission list-mode dataset was divided into 8 frames of 5 min. The reconstructed time-framed images were aligned to a selected reference frame using either EMT or the AIR...

  9. Development of depth encoding small animal PET detectors using dual-ended readout of pixelated scintillator arrays with SiPMs.

    Science.gov (United States)

    Kuang, Zhonghua; Sang, Ziru; Wang, Xiaohui; Fu, Xin; Ren, Ning; Zhang, Xianming; Zheng, Yunfei; Yang, Qian; Hu, Zhanli; Du, Junwei; Liang, Dong; Liu, Xin; Zheng, Hairong; Yang, Yongfeng

    2018-02-01

    The performance of current small animal PET scanners is mainly limited by the detector performance and depth encoding detectors are required to develop PET scanner to simultaneously achieve high spatial resolution and high sensitivity. Among all depth encoding PET detector approaches, dual-ended readout detector has the advantage to achieve the highest depth of interaction (DOI) resolution and spatial resolution. Silicon photomultiplier (SiPM) is believed to be the photodetector of the future for PET detector due to its excellent properties as compared to the traditional photodetectors such as photomultiplier tube (PMT) and avalanche photodiode (APD). The purpose of this work is to develop high resolution depth encoding small animal PET detector using dual-ended readout of finely pixelated scintillator arrays with SiPMs. Four lutetium-yttrium oxyorthosilicate (LYSO) arrays with 11 × 11 crystals and 11.6 × 11.6 × 20 mm 3 outside dimension were made using ESR, Toray and BaSO 4 reflectors. The LYSO arrays were read out with Hamamatsu 4 × 4 SiPM arrays from both ends. The SiPM array has a pixel size of 3 × 3 mm 2 , 0.2 mm gap in between the pixels and a total active area of 12.6 × 12.6 mm 2 . The flood histograms, DOI resolution, energy resolution and timing resolution of the four detector modules were measured and compared. All crystals can be clearly resolved from the measured flood histograms of all four arrays. The BaSO 4 arrays provide the best and the ESR array provides the worst flood histograms. The DOI resolution obtained from the DOI profiles of the individual crystals of the four array is from 2.1 to 2.35 mm for events with E > 350 keV. The DOI ratio variation among crystals is bigger for the BaSO 4 arrays as compared to both the ESR and Toray arrays. The BaSO 4 arrays provide worse detector based DOI resolution. The photopeak amplitude of the Toray array had the maximum change with depth, it provides the worst energy resolution of

  10. Toward VIP-PIX: A Low Noise Readout ASIC for Pixelated CdTe Gamma-Ray Detectors for Use in the Next Generation of PET Scanners.

    Science.gov (United States)

    Macias-Montero, Jose-Gabriel; Sarraj, Maher; Chmeissani, Mokhtar; Puigdengoles, Carles; Lorenzo, Gianluca De; Martínez, Ricardo

    2013-08-01

    VIP-PIX will be a low noise and low power pixel readout electronics with digital output for pixelated Cadmium Telluride (CdTe) detectors. The proposed pixel will be part of a 2D pixel-array detector for various types of nuclear medicine imaging devices such as positron-emission tomography (PET) scanners, Compton gamma cameras, and positron-emission mammography (PEM) scanners. Each pixel will include a SAR ADC that provides the energy deposited with 10-bit resolution. Simultaneously, the self-triggered pixel which will be connected to a global time-to-digital converter (TDC) with 1 ns resolution will provide the event's time stamp. The analog part of the readout chain and the ADC have been fabricated with TSMC 0.25 μ m mixed-signal CMOS technology and characterized with an external test pulse. The power consumption of these parts is 200 μ W from a 2.5 V supply. It offers 4 switchable gains from ±10 mV/fC to ±40 mV/fC and an input charge dynamic range of up to ±70 fC for the minimum gain for both polarities. Based on noise measurements, the expected equivalent noise charge (ENC) is 65 e - RMS at room temperature.

  11. Non-invasive imaging of acute renal allograft rejection in rats using small animal F-FDG-PET.

    Directory of Open Access Journals (Sweden)

    Stefan Reuter

    Full Text Available BACKGROUND: At present, renal grafts are the most common solid organ transplants world-wide. Given the importance of renal transplantation and the limitation of available donor kidneys, detailed analysis of factors that affect transplant survival are important. Despite the introduction of new and effective immunosuppressive drugs, acute cellular graft rejection (AR is still a major risk for graft survival. Nowadays, AR can only be definitively by renal biopsy. However, biopsies carry a risk of renal transplant injury and loss. Most important, they can not be performed in patients taking anticoagulant drugs. METHODOLOGY/PRINCIPAL FINDINGS: We present a non-invasive, entirely image-based method to assess AR in an allogeneic rat renal transplantation model using small animal positron emission tomography (PET and (18F-fluorodeoxyglucose (FDG. 3 h after i.v. injection of 30 MBq FDG into adult uni-nephrectomized, allogeneically transplanted rats, tissue radioactivity of renal parenchyma was assessed in vivo by a small animal PET-scanner (post operative day (POD 1,2,4, and 7 and post mortem dissection. The mean radioactivity (cps/mm(3 tissue as well as the percent injected dose (%ID was compared between graft and native reference kidney. Results were confirmed by histological and autoradiographic analysis. Healthy rats, rats with acute CSA nephrotoxicity, with acute tubular necrosis, and syngeneically transplanted rats served as controls. FDG-uptake was significantly elevated only in allogeneic grafts from POD 1 on when compared to the native kidney (%ID graft POD 1: 0.54+/-0.06; POD 2: 0.58+/-0.12; POD 4: 0.81+/-0.06; POD 7: 0.77+/-0.1; CTR: 0.22+/-0.01, n = 3-28. Renal FDG-uptake in vivo correlated with the results obtained by micro-autoradiography and the degree of inflammatory infiltrates observed in histology. CONCLUSIONS/SIGNIFICANCE: We propose that graft FDG-PET imaging is a new option to non-invasively, specifically, early detect, and follow

  12. 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.

  13. Questions and Answers about Ebola, Pets, and Other Animals

    Science.gov (United States)

    ... the U.S. Guidance for Cleaning, Disinfection, and Waste Disposal in Commercial Passenger Aircraft Diagnosis Treatment Sierra Leone ... Ebola Virus in Medical Waste Handling Ebola-Associated Waste ... and Animal Product Import is available. Each state and U.S. Territory ...

  14. Evaluation of Pattern of Pet Animal Trauma at the Veterinary ...

    African Journals Online (AJOL)

    The record of 114 small animal trauma cases seen at the Surgery Unit of the Veterinary Teaching Hospital (VTH), Ibadan between 2008 and 2012 were studied to evaluate the pattern of trauma with reference to species, sex, age groups, causes of trauma, regional involvement, severity including fatalities, in order to develop ...

  15. Anesthesia condition for 18F-FDG imaging of lung metastasis tumors using small animal PET

    International Nuclear Information System (INIS)

    Woo, Sang-Keun; Lee, Tae Sup; Kim, Kyeong Min; Kim, June-Youp; Jung, Jae Ho; Kang, Joo Hyun; Cheon, Gi Jeong; Choi, Chang Woon; Lim, Sang Moo

    2008-01-01

    Small animal positron emission tomography (PET) with 18 F-FDG has been increasingly used for tumor imaging in the murine model. The aim of this study was to establish the anesthesia condition for imaging of lung metastasis tumor using small animal 18 F-FDG PET. Methods: To determine the impact of anesthesia on 18 F-FDG distribution in normal mice, five groups were studied under the following conditions: no anesthesia, ketamine and xylazine (Ke/Xy), 0.5% isoflurane (Iso 0.5), 1% isoflurane (Iso 1) and 2% isoflurane (Iso 2). The ex vivo counting, standard uptake value (SUV) image and glucose SUV of 18 F-FDG in various tissues were evaluated. The 18 F-FDG images in the lung metastasis tumor model were obtained under no anesthesia, Ke/Xy and Iso 0.5, and registered with CT image to clarify the tumor region. Results: Blood glucose concentration and muscle uptake of 18 F-FDG in the Ke/Xy group markedly increased more than in the other groups. The Iso 2 group increased 18 F-FDG uptake in heart compared with the other groups. The Iso 0.5 anesthesized group showed the lowest 18 F-FDG uptake in heart and chest wall. The small size of lung metastasis tumor (2 mm) was clearly visualized by 18 F-FDG image with the Iso 0.5 anesthesia. Conclusion: Small animal 18 F-FDG PET imaging with Iso 0.5 anesthesia was appropriate for the detection of lung metastasis tumor. To acquire 18 F-FDG PET images with small animal PET, the type and level of anesthetic should be carefully considered to be suitable for the visualization of target tissue in the experimental model

  16. Development of a Si-PM-based high-resolution PET system for small animals

    International Nuclear Information System (INIS)

    Yamamoto, Seiichi; Imaizumi, Masao; Watabe, Tadashi; Shimosegawa, Eku; Hatazawa, Jun; Watabe, Hiroshi; Kanai, Yasukazu

    2010-01-01

    A Geiger-mode avalanche photodiode (Si-PM) is a promising photodetector for PET, especially for use in a magnetic resonance imaging (MRI) system, because it has high gain and is less sensitive to a static magnetic field. We developed a Si-PM-based depth-of-interaction (DOI) PET system for small animals. Hamamatsu 4 x 4 Si-PM arrays (S11065-025P) were used for its detector blocks. Two types of LGSO scintillator of 0.75 mol% Ce (decay time: ∼45 ns; 1.1 mm x 1.2 mm x 5 mm) and 0.025 mol% Ce (decay time: ∼31 ns; 1.1 mm x 1.2 mm x 6 mm) were optically coupled in the DOI direction to form a DOI detector, arranged in a 11 x 9 matrix, and optically coupled to the Si-PM array. Pulse shape analysis was used for the DOI detection of these two types of LGSOs. Sixteen detector blocks were arranged in a 68 mm diameter ring to form the PET system. Spatial resolution was 1.6 mm FWHM and sensitivity was 0.6% at the center of the field of view. High-resolution mouse and rat images were successfully obtained using the PET system. We confirmed that the developed Si-PM-based PET system is promising for molecular imaging research.

  17. Development of a Si-PM-based high-resolution PET system for small animals

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Seiichi [Kobe City College of Technology, Kobe (Japan); Imaizumi, Masao; Watabe, Tadashi; Shimosegawa, Eku; Hatazawa, Jun [Department of Nuclear Medicine and Tracer Kinetics, Osaka University Graduate School of Medicine, Osaka (Japan); Watabe, Hiroshi; Kanai, Yasukazu, E-mail: s-yama@kobe-kosen.ac.j [Department of Molecular Imaging in Medicine, Osaka University Graduate School of Medicine, Osaka (Japan)

    2010-10-07

    A Geiger-mode avalanche photodiode (Si-PM) is a promising photodetector for PET, especially for use in a magnetic resonance imaging (MRI) system, because it has high gain and is less sensitive to a static magnetic field. We developed a Si-PM-based depth-of-interaction (DOI) PET system for small animals. Hamamatsu 4 x 4 Si-PM arrays (S11065-025P) were used for its detector blocks. Two types of LGSO scintillator of 0.75 mol% Ce (decay time: {approx}45 ns; 1.1 mm x 1.2 mm x 5 mm) and 0.025 mol% Ce (decay time: {approx}31 ns; 1.1 mm x 1.2 mm x 6 mm) were optically coupled in the DOI direction to form a DOI detector, arranged in a 11 x 9 matrix, and optically coupled to the Si-PM array. Pulse shape analysis was used for the DOI detection of these two types of LGSOs. Sixteen detector blocks were arranged in a 68 mm diameter ring to form the PET system. Spatial resolution was 1.6 mm FWHM and sensitivity was 0.6% at the center of the field of view. High-resolution mouse and rat images were successfully obtained using the PET system. We confirmed that the developed Si-PM-based PET system is promising for molecular imaging research.

  18. Assessment of myocardial metabolic rate of glucose by means of Bayesian ICA and Markov Chain Monte Carlo methods in small animal PET imaging

    Science.gov (United States)

    Berradja, Khadidja; Boughanmi, Nabil

    2016-09-01

    In dynamic cardiac PET FDG studies the assessment of myocardial metabolic rate of glucose (MMRG) requires the knowledge of the blood input function (IF). IF can be obtained by manual or automatic blood sampling and cross calibrated with PET. These procedures are cumbersome, invasive and generate uncertainties. The IF is contaminated by spillover of radioactivity from the adjacent myocardium and this could cause important error in the estimated MMRG. In this study, we show that the IF can be extracted from the images in a rat heart study with 18F-fluorodeoxyglucose (18F-FDG) by means of Independent Component Analysis (ICA) based on Bayesian theory and Markov Chain Monte Carlo (MCMC) sampling method (BICA). Images of the heart from rats were acquired with the Sherbrooke small animal PET scanner. A region of interest (ROI) was drawn around the rat image and decomposed into blood and tissue using BICA. The Statistical study showed that there is a significant difference (p corrupted with spillover.

  19. 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...

  20. Prototype pre-clinical PET scanner with depth-of-interaction measurements using single-layer crystal array and single-ended readout

    Science.gov (United States)

    Lee, Min Sun; Kim, Kyeong Yun; Ko, Guen Bae; Lee, Jae Sung

    2017-05-01

    In this study, we developed a proof-of-concept prototype PET system using a pair of depth-of-interaction (DOI) PET detectors based on the proposed DOI-encoding method and digital silicon photomultiplier (dSiPM). Our novel cost-effective DOI measurement method is based on a triangular-shaped reflector that requires only a single-layer pixelated crystal and single-ended signal readout. The DOI detector consisted of an 18  ×  18 array of unpolished LYSO crystal (1.47  ×  1.47  ×  15 mm3) wrapped with triangular-shaped reflectors. The DOI information was encoded by depth-dependent light distribution tailored by the reflector geometry and DOI correction was performed using four-step depth calibration data and maximum-likelihood (ML) estimation. The detector pair and the object were placed on two motorized rotation stages to demonstrate 12-block ring PET geometry with 11.15 cm diameter. Spatial resolution was measured and phantom and animal imaging studies were performed to investigate imaging performance. All images were reconstructed with and without the DOI correction to examine the impact of our DOI measurement. The pair of dSiPM-based DOI PET detectors showed good physical performances respectively: 2.82 and 3.09 peak-to-valley ratios, 14.30% and 18.95% energy resolution, and 4.28 and 4.24 mm DOI resolution averaged over all crystals and all depths. A sub-millimeter spatial resolution was achieved at the center of the field of view (FOV). After applying ML-based DOI correction, maximum 36.92% improvement was achieved in the radial spatial resolution and a uniform resolution was observed within 5 cm of transverse PET FOV. We successfully acquired phantom and animal images with improved spatial resolution and contrast by using the DOI measurement. The proposed DOI-encoding method was successfully demonstrated in the system level and exhibited good performance, showing its feasibility for animal PET applications with high spatial

  1. Evaluation of cat brain infarction model using microPET

    International Nuclear Information System (INIS)

    Lee, J. J.; Lee, D. S.; Kim, J. H.; Hwang, D. W.; Jung, J. G.; Lee, M. C; Lim, S. M

    2004-01-01

    PET has some disadvantage in the imaging of small animal due to poor resolution. With the advance of microPET scanner, it is possible to image small animals. However, the image quality was not so much satisfactory as human image. As cats have relatively large sized brain, cat brain imaging was superior to mice or rat. In this study, we established the cat brain infarction model and evaluate it and its temporal change using microPET scanner. Two adult male cats were used. Anesthesia was done with xylazine and ketamine HCl. A burr hole was made at 1cm right lateral to the bregma. Collagenase type IV 10 ul was injected using 30G needle for 5 minutes to establish the infarction model. F-18 FDG microPET (Concorde Microsystems Inc., Knoxville. TN) scans were performed 1. 11 and 32 days after the infarction. In addition. 18F-FDG PET scans were performed using Gemini PET scanner (Philips medical systems. CA, USA) 13 and 47 days after the infarction. Two cat brain infarction models were established. The glucose metabolism of an infraction lesion improved with time. An infarction lesion was also distinguishable in the Gemini PET scan. We successfully established the cat brain infarction model and evaluated the infarcted lesion and its temporal change using F-18 FDG microPET scanner

  2. Evaluation of cat brain infarction model using microPET

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jong Jin; Lee, Dong Soo; Kim, Yun Hui; Hwang, Do Won; Kim, Jin Su; Chung, June Key; Lee, Myung Chul [College of Medicine, Seoul National Univ., Seoul (Korea, Republic of); Lim, Sang Moo [Korea Institite of Radiological and Medical Sciences, Seoul (Korea, Republic of)

    2004-12-01

    PET has some disadvantage in the imaging of small animal due to poor resolution. With the advent of microPET scanner, it is possible to image small animals. However, the image quality was not good enough as human image. Due to larger brain, cat brain imaging was superior to mouse or rat. In this study, we established the cat brain infarction model and evaluate it and its temporal change using microPET scanner. Two adult male cats were used. Anesthesia was done with xylazine and ketamine HCI. A burr hole was made at 1 cm right lateral to the bregma. Collagenase type IV 10 {mu}l was injected using 30 G needle for 5 minutes to establish the infarction model. {sup 18}F-FDG microPET (Concorde Microsystems Inc., Knoxville, TN) scans were performed 1, 11 and 32 days after the infarction. In addition, {sup 18}F-FDG PET scans were performed using human PET scanner (Gemini, Philips medical systems, CA, USA) 13 and 47 days after the infarction. Two cat brain infarction models were established. The glucose metabolism of an infarction lesion improved with time. An infarction lesion was also distinguishable in the human PET scan. We successfully established the cat brain infarction model and evaluated the infarcted lesion and its temporal change using {sup 18}F-FDG microPET scanner.

  3. Evaluation of cat brain infarction model using microPET

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J. J.; Lee, D. S.; Kim, J. H.; Hwang, D. W.; Jung, J. G.; Lee, M. C [College of Medicine, Seoul National University, Seoul (Korea, Republic of); Lim, S. M [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

    2004-07-01

    PET has some disadvantage in the imaging of small animal due to poor resolution. With the advance of microPET scanner, it is possible to image small animals. However, the image quality was not so much satisfactory as human image. As cats have relatively large sized brain, cat brain imaging was superior to mice or rat. In this study, we established the cat brain infarction model and evaluate it and its temporal change using microPET scanner. Two adult male cats were used. Anesthesia was done with xylazine and ketamine HCl. A burr hole was made at 1cm right lateral to the bregma. Collagenase type IV 10 ul was injected using 30G needle for 5 minutes to establish the infarction model. F-18 FDG microPET (Concorde Microsystems Inc., Knoxville. TN) scans were performed 1. 11 and 32 days after the infarction. In addition. 18F-FDG PET scans were performed using Gemini PET scanner (Philips medical systems. CA, USA) 13 and 47 days after the infarction. Two cat brain infarction models were established. The glucose metabolism of an infraction lesion improved with time. An infarction lesion was also distinguishable in the Gemini PET scan. We successfully established the cat brain infarction model and evaluated the infarcted lesion and its temporal change using F-18 FDG microPET scanner.

  4. Initial studies using the RatCAP conscious animal PET tomograph

    Science.gov (United States)

    Woody, C.; Vaska, P.; Schlyer, D.; Pratte, J.-F.; Junnarkar, S.; Park, S.-J.; Stoll, S.; Purschke, M.; Southekal, S.; Kriplani, A.; Krishnamoorthy, S.; Maramraju, S.; Lee, D.; Schiffer, W.; Dewey, S.; Neill, J.; Kandasamy, A.; O'Connor, P.; Radeka, V.; Fontaine, R.; Lecomte, R.

    2007-02-01

    The RatCAP is a small, head-mounted PET tomograph designed to image the brain of a conscious rat without the use of anesthesia. The detector is a complete, high-performance 3D tomograph consisting of a 3.8 cm inside-diameter ring containing 12 block detectors, each of which is comprised of a 4×8 array of 2.2×2.2×5 mm 3 LSO crystals readout with a matching APD array and custom ASIC, and has a 1.8 cm axial field of view. Construction of the first working prototype detector has been completed and its performance characteristics have been measured. The results show an intrinsic spatial resolution of 2.1 mm, a time resolution of ˜14 ns FWHM, and a sensitivity of 0.7% at an energy threshold of 150 keV. First preliminary images have been obtained using 18F-FDG and 11C-methamphetamine, which show comparable image quality to those obtained from a commercial MicroPET R4 scanner. Initial studies have also been carried out to study stress levels in rats wearing the RatCAP.

  5. Initial studies using the RatCAP conscious animal PET tomograph

    Energy Technology Data Exchange (ETDEWEB)

    Woody, C. [Brookhaven National Laboratory, Upton, NY (United States)]. E-mail: woody@bnl.gov; Vaska, P. [Brookhaven National Laboratory, Upton, NY (United States); Schlyer, D. [Brookhaven National Laboratory, Upton, NY (United States); Pratte, J.-F. [Brookhaven National Laboratory, Upton, NY (United States); Junnarkar, S. [Brookhaven National Laboratory, Upton, NY (United States); Park, S.-J. [Brookhaven National Laboratory, Upton, NY (United States); Stoll, S. [Brookhaven National Laboratory, Upton, NY (United States); Purschke, M. [Brookhaven National Laboratory, Upton, NY (United States); Southekal, S. [Stony Brook University, Stony Brook, NY (United States); Kriplani, A. [Stony Brook University, Stony Brook, NY (United States); Krishnamoorthy, S. [Stony Brook University, Stony Brook, NY (United States); Maramraju, S. [Stony Brook University, Stony Brook, NY (United States); Lee, D. [Brookhaven National Laboratory, Upton, NY (United States); Schiffer, W. [Brookhaven National Laboratory, Upton, NY (United States); Dewey, S. [Brookhaven National Laboratory, Upton, NY (United States); Neill, J. [Long Island University, Brookville, NY (United States); Kandasamy, A. [Brookhaven National Laboratory, Upton, NY (United States); O' Connor, P. [Brookhaven National Laboratory, Upton, NY (United States); Radeka, V. [Brookhaven National Laboratory, Upton, NY (United States); Fontaine, R. [Sherbrooke University, Sherbrooke, Que. (Canada); Lecomte, R. [Sherbrooke University, Sherbrooke, Que. (Canada)

    2007-02-01

    The RatCAP is a small, head-mounted PET tomograph designed to image the brain of a conscious rat without the use of anesthesia. The detector is a complete, high-performance 3D tomograph consisting of a 3.8 cm inside-diameter ring containing 12 block detectors, each of which is comprised of a 4x8 array of 2.2x2.2x5 mm{sup 3} LSO crystals readout with a matching APD array and custom ASIC, and has a 1.8 cm axial field of view. Construction of the first working prototype detector has been completed and its performance characteristics have been measured. The results show an intrinsic spatial resolution of 2.1 mm, a time resolution of {approx}14 ns FWHM, and a sensitivity of 0.7% at an energy threshold of 150 keV. First preliminary images have been obtained using {sup 18}F-FDG and {sup 11}C-methamphetamine, which show comparable image quality to those obtained from a commercial MicroPET R4 scanner. Initial studies have also been carried out to study stress levels in rats wearing the RatCAP.

  6. Addressing the problem of pet overpopulation: the experience of New Hanover County Animal Control Services.

    Science.gov (United States)

    McNeil, Jean; Constandy, Elisabeth

    2006-01-01

    Pet overpopulation is a problem for humans not only because of the increased rabies exposure risk but also because it puts a strain on animal control agencies, which must care for, house, and often euthanize the unwanted animals. New Hanover County, North Carolina, Animal Control Services saw the need to control this problem and developed a plan to diminish the number of unwanted companion animals in its community. With the help of training through the UNC Management Academy for Public Health, they created a successful business plan to build an on-site spay/neuter facility. The facility began operations in 2004. As of January 31, 2006, a total of 1,108 surgeries had been completed in the new facility, with no added cost to taxpayers. The facility has been a success for Animal Control Services, the Health Department, and the community as a whole.

  7. High throughput static and dynamic small animal imaging using clinical PET/CT: potential preclinical applications

    International Nuclear Information System (INIS)

    Aide, Nicolas; Desmonts, Cedric; Agostini, Denis; Bardet, Stephane; Bouvard, Gerard; Beauregard, Jean-Mathieu; Roselt, Peter; Neels, Oliver; Beyer, Thomas; Kinross, Kathryn; Hicks, Rodney J.

    2010-01-01

    The objective of the study was to evaluate state-of-the-art clinical PET/CT technology in performing static and dynamic imaging of several mice simultaneously. A mouse-sized phantom was imaged mimicking simultaneous imaging of three mice with computation of recovery coefficients (RCs) and spillover ratios (SORs). Fifteen mice harbouring abdominal or subcutaneous tumours were imaged on clinical PET/CT with point spread function (PSF) reconstruction after injection of [18F]fluorodeoxyglucose or [18F]fluorothymidine. Three of these mice were imaged alone and simultaneously at radial positions -5, 0 and 5 cm. The remaining 12 tumour-bearing mice were imaged in groups of 3 to establish the quantitative accuracy of PET data using ex vivo gamma counting as the reference. Finally, a dynamic scan was performed in three mice simultaneously after the injection of 68 Ga-ethylenediaminetetraacetic acid (EDTA). For typical lesion sizes of 7-8 mm phantom experiments indicated RCs of 0.42 and 0.76 for ordered subsets expectation maximization (OSEM) and PSF reconstruction, respectively. For PSF reconstruction, SOR air and SOR water were 5.3 and 7.5%, respectively. A strong correlation (r 2 = 0.97, p 2 = 0.98; slope = 0.89, p 2 = 0.96; slope = 0.62, p 68 Ga-EDTA dynamic acquisition. New generation clinical PET/CT can be used for simultaneous imaging of multiple small animals in experiments requiring high throughput and where a dedicated small animal PET system is not available. (orig.)

  8. Multi-modality image reconstruction for dual-head small-animal PET

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Chang-Han; Chou, Cheng-Ying [National Taiwan University, Taipei, Taiwan (China)

    2015-05-18

    The hybrid positron emission tomography/computed tomography (PET/CT) or positron emission tomography/magnetic resonance imaging (PET/MRI) has become routine practice in clinics. The applications of multi-modality imaging can also benefit research advances. Consequently, dedicated small-imaging system like dual-head small-animal PET (DHAPET) that possesses the advantages of high detection sensitivity and high resolution can exploit the structural information from CT or MRI. It should be noted that the special detector arrangement in DHAPET leads to severe data truncation, thereby degrading the image quality. We proposed to take advantage of anatomical priors and total variation (TV) minimization methods to reconstruct PET activity distribution form incomplete measurement data. The objective is to solve the penalized least-squares function consisted of data fidelity term, TV norm and medium root priors. In this work, we employed the splitting-based fast iterative shrinkage/thresholding algorithm to split smooth and non-smooth functions in the convex optimization problems. Our simulations studies validated that the images reconstructed by use of the proposed method can outperform those obtained by use of conventional expectation maximization algorithms or that without considering the anatomical prior information. Additionally, the convergence rate is also accelerated.

  9. Strategies for improving the Voxel-based statistical analysis for animal PET studies: assessment of cerebral glucose metabolism in cat deafness model

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Su; Lee, Jae Sung; Park, Min Hyun; Kang, Hye Jin; Im, Ki Chun; Moon, Dae Hyuk; Lim, Sang Moo; Oh, Seung Ha; Lee, Dong Soo [Seoul National Univ. College of Medicine, Seoul (Korea, Republic of)

    2007-07-01

    In imaging studies of the human brain, voxel-based statistical analysis method was widely used, since these methods were originally developed for the analysis of the human brain data, they are not optimal for the animal brain data. The aim of this study is to optimize the procedures for the 3D voxel-based statistical analysis of cat FDG PET brain images. A microPET Focus 120 scanner was used. Eight cats underwent FDG PET scans twice before and after inducing the deafness. Only the brain and adjacent regions were extracted from each data set by manual masking. Individual PET image at normal and deaf state was realigned to each other to remove the confounding effects by the different spatial normalization parameters on the results of statistical analyses. Distance between the sampling points on the reference image and kernel size of Gaussian filter applied to the images before estimating the realignment parameters were adjusted to 0.5 mm and 2 mm. Both data was then spatial normalized onto study-specific cat brain template. Spatially normalized PET data were smoothed and voxel-based paired t-test was performed. Cerebral glucose metabolism decreased significantly after the loss of hearing capability in parietal lobes, postcentral gyri, STG, MTG, lTG, and IC at both hemisphere and left SC (FDR corrected P < 0.05, k=50). Cerebral glucose metabolism in deaf cats was found to be significantly higher than in controls in the right cingulate (FDR corrected P < 0.05, k=50). The ROI analysis also showed significant reduction of glucose metabolism in the same areas as in the SPM analysis, except for some regions (P < 0.05). Method for the voxel-based analysis of cat brain PET data was optimized for analysis of cat brain PET. This result was also confirmed by ROI analysis. The results obtained demonstrated the high localization accuracy and specificity of the developed method, and were found to be useful for examining cerebral glucose metabolism in a cat cortical deafness model.

  10. Prevalence, species distribution and antimicrobial resistance patterns of methicillin-resistant staphylococci in Lithuanian pet animals.

    Science.gov (United States)

    Ruzauskas, Modestas; Couto, Natacha; Kerziene, Sigita; Siugzdiniene, Rita; Klimiene, Irena; Virgailis, Marius; Pomba, Constança

    2015-06-02

    The bacterial genus Staphylococcus consists of many species that causes infections in pet animals. Antimicrobial resistant staphylococci cause infections that are difficult to treat and they are important from the point of one health perspective. The aim of this study was to determine the prevalence of methicillin-resistant Staphylococcus (MRS) species, including methicillin-resistant S. aureus (MRSA) in diseased pet animals (Group A) and kennel dogs (Group B) in Lithuania and to characterize the isolates according to their antimicrobial resistance. Twenty-one MRS isolates were obtained from 395 clinical samples (5.3 %; CI 95 % 3.5-8.0) of Group A animals. Sixteen, four and one isolates were from dogs, cats and a pet rabbit, respectively. The mecA gene was present in 20 isolates, whereas one isolate was positive for the mecC gene. Twenty-one MRS isolates (20.0 %; CI 95 % 13.5-28.6) were obtained from the vagina of female dogs (n = 105) (Group B). All isolates carried the mecA gene. Twelve MRS species were isolated of which S. pseudintermedius was the most common (18/42) followed by S. haemolyticus (8/42) and S. lentus (4/42). MRSA was not found. All MRS strains were susceptible to vancomycin, linezolid, daptomycin and quinupristin/dalfopristin. Resistance to tetracycline (16/21), clindamycin (15/21) and erythromycin (14/21) was the most common types of resistance in Group A animals. Three isolates also demonstrated resistance to rifampin. Resistance toward gentamicin (16/21), ciprofloxacin (15/21), macrolides (15/21) and tetracycline (12/21) was the most common in kennel dogs (Group B). The most common genes encoding resistance to antimicrobials (excluding beta-lactams) in isolates from Group A pets were tetK (21/42), aph(3')-IIIa (11/42) and aac(6')-Ie-aph(2'')-Ia (9/42). A wide range of MRS species were found in pet animals in Lithuania. MRSA was not found.

  11. Performing Repeated Quantitative Small-Animal PET with an Arterial Input Function Is Routinely Feasible in Rats.

    Science.gov (United States)

    Huang, Chi-Cheng; Wu, Chun-Hu; Huang, Ya-Yao; Tzen, Kai-Yuan; Chen, Szu-Fu; Tsai, Miao-Ling; Wu, Hsiao-Ming

    2017-04-01

    Performing quantitative small-animal PET with an arterial input function has been considered technically challenging. Here, we introduce a catheterization procedure that keeps a rat physiologically stable for 1.5 mo. We demonstrated the feasibility of quantitative small-animal 18 F-FDG PET in rats by performing it repeatedly to monitor the time course of variations in the cerebral metabolic rate of glucose (CMR glc ). Methods: Aseptic surgery was performed on 2 rats. Each rat underwent catheterization of the right femoral artery and left femoral vein. The catheters were sealed with microinjection ports and then implanted subcutaneously. Over the next 3 wk, each rat underwent 18 F-FDG quantitative small-animal PET 6 times. The CMR glc of each brain region was calculated using a 3-compartment model and an operational equation that included a k* 4 Results: On 6 mornings, we completed 12 18 F-FDG quantitative small-animal PET studies on 2 rats. The rats grew steadily before and after the 6 quantitative small-animal PET studies. The CMR glc of the conscious brain (e.g., right parietal region, 99.6 ± 10.2 μmol/100 g/min; n = 6) was comparable to that for 14 C-deoxyglucose autoradiographic methods. Conclusion: Maintaining good blood patency in catheterized rats is not difficult. Longitudinal quantitative small-animal PET imaging with an arterial input function can be performed routinely. © 2017 by the Society of Nuclear Medicine and Molecular Imaging.

  12. Kinetic parametric estimation in animal PET molecular imaging based on artificial immune network

    International Nuclear Information System (INIS)

    Chen Yuting; Ding Hong; Lu Rui; Huang Hongbo; Liu Li

    2011-01-01

    Objective: To develop an accurate,reliable method without the need of initialization in animal PET modeling for estimation of the tracer kinetic parameters based on the artificial immune network. Methods: The hepatic and left ventricular time activity curves (TACs) were obtained by drawing ROIs of liver tissue and left ventricle on dynamic 18 F-FDG PET imaging of small mice. Meanwhile, the blood TAC was analyzed by sampling the tail vein blood at different time points after injection. The artificial immune network for parametric optimization of pharmacokinetics (PKAIN) was adapted to estimate the model parameters and the metabolic rate of glucose (K i ) was calculated. Results: TACs of liver,left ventricle and tail vein blood were obtained.Based on the artificial immune network, K i in 3 mice was estimated as 0.0024, 0.0417 and 0.0047, respectively. The average weighted residual sum of squares of the output model generated by PKAIN was less than 0.0745 with a maximum standard deviation of 0.0084, which indicated that the proposed PKAIN method can provide accurate and reliable parametric estimation. Conclusion: The PKAIN method could provide accurate and reliable tracer kinetic modeling in animal PET imaging without the need of initialization of model parameters. (authors)

  13. 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.  ...

  14. Design and development of a high resolution animal SPECT scanner dedicated for rat and mouse imaging

    International Nuclear Information System (INIS)

    Sajedi, Salar; Zeraatkar, Navid; Moji, Vahideh; Farahani, Mohammad Hossein; Sarkar, Saeed; Arabi, Hossein; Teymoorian, Behnoosh; Ghafarian, Pardis; Rahmim, Arman; Reza Ay, Mohammad

    2014-01-01

    A dedicated small-animal SPECT system, HiReSPECT, was designed and developed to provide a high resolution molecular imaging modality in response to growing research demands. HiReSPECT is a dual-head system mounted on a rotating gantry. The detection system is based on pixelated CsI(Na) scintillator crystals coupled to two Hamamatsu H8500 Position Sensitive Photomultiplier Tubes in each head. Also, a high resolution parallel-hole collimator is applied to every head. The dimensions of each head are 50 mm×100 mm, enabling sufficient transaxial and axial fields-of-view (TFOV and AFOV), respectively, for coverage of the entire mouse in single-bed position imaging. However, a 50 mm TFOV is not sufficient for transaxial coverage of rats. To address this, each head can be rotated by 90 degrees in order to align the larger dimension of the heads with the short body axis, allowing tomographic data acquisition for rats. An innovative non-linear recursive filter was used for signal processing/detection. Resolution recovery was also embedded in the modified Maximum-Likelihood Expectation Maximization (MLEM) image reconstruction code to compensate for Collimator-Detector Response (CDR). Moreover, an innovative interpolation algorithm was developed to speed up the reconstruction code. The planar spatial resolution at the head surface and the image spatial resolutions were 1.7 mm and 1.2–1.6 mm, respectively. The measurements followed by post-processing showed that the observed count rate at 20% count loss is about 42 kcps. The system sensitivity at the collimator surface for heads 1 and 2 were 1.32 cps/µCi and 1.25 cps/µCi, respectively. The corresponding values were 1.18 cps/µCi and 1.02 cps/µCi at 8 cm distance from the collimator surfaces. In addition, whole-body scans of mice demonstrated appropriate imaging capability of the HiReSPECT

  15. Animal health care seeking behavior of pets or livestock owners and knowledge and awareness on zoonoses in a university community

    Directory of Open Access Journals (Sweden)

    Emmanuel J. Awosanya

    2015-07-01

    Full Text Available Aim: We investigated the attitude of pets or livestock owning households in a university community to animal health care services and assessed the knowledge and awareness level of the residents on zoonoses. Materials and Methods: Structured questionnaire was used to obtain information on demography, pet or livestock ownership, animal health care seeking behavior, awareness and knowledge of zoonoses from 246 households. We did descriptive statistics and bivariate analysis to determine the level of association in discrete variables between owners and non-owners of pets or livestock at a significant level of p<0.05. Results: Of the 246 respondents, 80 (32.5% were either pet or livestock owners. The animal health care seeking behavior of the 80 pets or livestock owners in terms of treatment and vaccination was 70%. Of the 56 (70% who provided health care services for their animals, about 48 (85.7% engaged the services of a veterinarian. Dog owning households (42 had the highest frequency of treating their pets against endoparasites (97.6%; ectoparasites (81% and vaccination against diseases (73.8%. Of the 246 respondents, only 47 (19.1% have heard of the term zoonoses. Of the considered zoonoses; their awareness of rabies (79.3% was the highest, followed by Lassa fever (66.3%, the least was pasteurellosis with 18.7%. Having pets or livestock was significantly associated (p=0.04 with rabies awareness. However, there is no significant difference in the level of awareness of zoonoses; knowledge of zoonoses, knowledge of prevention of zoonoses and knowledge of risk of zoonoses between owners and non-owners of pets or livestock. Conclusion: The animal health care seeking behavior of households with pets or livestock is good and should be encouraged. Public education should be created for other zoonoses aside from rabies, Lassa fever, and avian influenza.

  16. Automated analysis of small animal PET studies through deformable registration to an atlas

    International Nuclear Information System (INIS)

    Gutierrez, Daniel F.; Zaidi, Habib

    2012-01-01

    This work aims to develop a methodology for automated atlas-guided analysis of small animal positron emission tomography (PET) data through deformable registration to an anatomical mouse model. A non-rigid registration technique is used to put into correspondence relevant anatomical regions of rodent CT images from combined PET/CT studies to corresponding CT images of the Digimouse anatomical mouse model. The latter provides a pre-segmented atlas consisting of 21 anatomical regions suitable for automated quantitative analysis. Image registration is performed using a package based on the Insight Toolkit allowing the implementation of various image registration algorithms. The optimal parameters obtained for deformable registration were applied to simulated and experimental mouse PET/CT studies. The accuracy of the image registration procedure was assessed by segmenting mouse CT images into seven regions: brain, lungs, heart, kidneys, bladder, skeleton and the rest of the body. This was accomplished prior to image registration using a semi-automated algorithm. Each mouse segmentation was transformed using the parameters obtained during CT to CT image registration. The resulting segmentation was compared with the original Digimouse atlas to quantify image registration accuracy using established metrics such as the Dice coefficient and Hausdorff distance. PET images were then transformed using the same technique and automated quantitative analysis of tracer uptake performed. The Dice coefficient and Hausdorff distance show fair to excellent agreement and a mean registration mismatch distance of about 6 mm. The results demonstrate good quantification accuracy in most of the regions, especially the brain, but not in the bladder, as expected. Normalized mean activity estimates were preserved between the reference and automated quantification techniques with relative errors below 10 % in most of the organs considered. The proposed automated quantification technique is

  17. The Pet Factor - Companion Animals as a Conduit for Getting to Know People, Friendship Formation and Social Support

    Science.gov (United States)

    Wood, Lisa; Martin, Karen; Christian, Hayley; Nathan, Andrea; Lauritsen, Claire; Houghton, Steve; Kawachi, Ichiro; McCune, Sandra

    2015-01-01

    Background While companion animals have been previously identified as a direct source of companionship and support to their owners, their role as a catalyst for friendship formation or social support networks among humans has received little attention. This study investigated the indirect role of pets as facilitators for three dimensions of social relatedness; getting to know people, friendship formation and social support networks. Methods A telephone survey of randomly selected residents in four cities, one in Australia (Perth; n = 704) and three in the U.S. (San Diego, n = 690; Portland, n = 634; Nashville, n = 664) was conducted. All participants were asked about getting to know people within their neighborhood. Pet owners were asked additional questions about the type/s of pet/s they owned, whether they had formed friendships as a result of their pet, and if they had received any of four different types of social support from the people they met through their pet. Results Pet owners were significantly more likely to get to know people in their neighborhood than non-pet owners (OR 1.61; 95%CI: 1.30, 1.99). When analyzed by site, this relationship was significant for Perth, San Diego and Nashville. Among pet owners, dog owners in the three U.S. cities (but not Perth) were significantly more likely than owners of other types of pets to regard people whom they met through their pet as a friend (OR 2.59; 95%CI: 1.94, 3.46). Around 40% of pet owners reported receiving one or more types of social support (i.e. emotional, informational, appraisal, instrumental) via people they met through their pet. Conclusion This research suggests companion animals can be a catalyst for several dimensions of human social relationships in neighborhood settings, ranging from incidental social interaction and getting to know people, through to formation of new friendships. For many pet owners, their pets also facilitated relationships from which they derived tangible forms of social

  18. The pet factor--companion animals as a conduit for getting to know people, friendship formation and social support.

    Science.gov (United States)

    Wood, Lisa; Martin, Karen; Christian, Hayley; Nathan, Andrea; Lauritsen, Claire; Houghton, Steve; Kawachi, Ichiro; McCune, Sandra

    2015-01-01

    While companion animals have been previously identified as a direct source of companionship and support to their owners, their role as a catalyst for friendship formation or social support networks among humans has received little attention. This study investigated the indirect role of pets as facilitators for three dimensions of social relatedness; getting to know people, friendship formation and social support networks. A telephone survey of randomly selected residents in four cities, one in Australia (Perth; n = 704) and three in the U.S. (San Diego, n = 690; Portland, n = 634; Nashville, n = 664) was conducted. All participants were asked about getting to know people within their neighborhood. Pet owners were asked additional questions about the type/s of pet/s they owned, whether they had formed friendships as a result of their pet, and if they had received any of four different types of social support from the people they met through their pet. Pet owners were significantly more likely to get to know people in their neighborhood than non-pet owners (OR 1.61; 95%CI: 1.30, 1.99). When analyzed by site, this relationship was significant for Perth, San Diego and Nashville. Among pet owners, dog owners in the three U.S. cities (but not Perth) were significantly more likely than owners of other types of pets to regard people whom they met through their pet as a friend (OR 2.59; 95%CI: 1.94, 3.46). Around 40% of pet owners reported receiving one or more types of social support (i.e. emotional, informational, appraisal, instrumental) via people they met through their pet. This research suggests companion animals can be a catalyst for several dimensions of human social relationships in neighborhood settings, ranging from incidental social interaction and getting to know people, through to formation of new friendships. For many pet owners, their pets also facilitated relationships from which they derived tangible forms of social support, both of a practical and

  19. The pet factor--companion animals as a conduit for getting to know people, friendship formation and social support.

    Directory of Open Access Journals (Sweden)

    Lisa Wood

    Full Text Available While companion animals have been previously identified as a direct source of companionship and support to their owners, their role as a catalyst for friendship formation or social support networks among humans has received little attention. This study investigated the indirect role of pets as facilitators for three dimensions of social relatedness; getting to know people, friendship formation and social support networks.A telephone survey of randomly selected residents in four cities, one in Australia (Perth; n = 704 and three in the U.S. (San Diego, n = 690; Portland, n = 634; Nashville, n = 664 was conducted. All participants were asked about getting to know people within their neighborhood. Pet owners were asked additional questions about the type/s of pet/s they owned, whether they had formed friendships as a result of their pet, and if they had received any of four different types of social support from the people they met through their pet.Pet owners were significantly more likely to get to know people in their neighborhood than non-pet owners (OR 1.61; 95%CI: 1.30, 1.99. When analyzed by site, this relationship was significant for Perth, San Diego and Nashville. Among pet owners, dog owners in the three U.S. cities (but not Perth were significantly more likely than owners of other types of pets to regard people whom they met through their pet as a friend (OR 2.59; 95%CI: 1.94, 3.46. Around 40% of pet owners reported receiving one or more types of social support (i.e. emotional, informational, appraisal, instrumental via people they met through their pet.This research suggests companion animals can be a catalyst for several dimensions of human social relationships in neighborhood settings, ranging from incidental social interaction and getting to know people, through to formation of new friendships. For many pet owners, their pets also facilitated relationships from which they derived tangible forms of social support, both of a practical

  20. Quantification in dynamic and small-animal positron emission tomography

    NARCIS (Netherlands)

    Disselhorst, Johannes Antonius

    2011-01-01

    This thesis covers two aspects of positron emission tomography (PET) quantification. The first section addresses the characterization and optimization of a small-animal PET/CT scanner. The sensitivity and resolution as well as various parameters affecting image quality (reconstruction settings, type

  1. No Pet or Their Person Left Behind: Increasing the Disaster Resilience of Vulnerable Groups through Animal Attachment, Activities and Networks

    Directory of Open Access Journals (Sweden)

    Kirrilly Thompson

    2014-05-01

    Full Text Available Increased vulnerability to natural disasters has been associated with particular groups in the community. This includes those who are considered de facto vulnerable (children, older people, those with disabilities etc. and those who own pets (not to mention pets themselves. The potential for reconfiguring pet ownership from a risk factor to a protective factor for natural disaster survival has been recently proposed. But how might this resilience-building proposition apply to vulnerable members of the community who own pets or other animals? This article addresses this important question by synthesizing information about what makes particular groups vulnerable, the challenges to increasing their resilience and how animals figure in their lives. Despite different vulnerabilities, animals were found to be important to the disaster resilience of seven vulnerable groups in Australia. Animal attachment and animal-related activities and networks are identified as underexplored devices for disseminating or ‘piggybacking’ disaster-related information and engaging vulnerable people in resilience building behaviors (in addition to including animals in disaster planning initiatives in general. Animals may provide the kind of innovative approach required to overcome the challenges in accessing and engaging vulnerable groups. As the survival of humans and animals are so often intertwined, the benefits of increasing the resilience of vulnerable communities through animal attachment is twofold: human and animal lives can be saved together.

  2. Public health ethics and a status for pets as person-things : revisiting the place of animals in urbanized societies.

    Science.gov (United States)

    Rock, Melanie; Degeling, Chris

    2013-12-01

    Within the field of medical ethics, discussions related to public health have mainly concentrated on issues that are closely tied to research and practice involving technologies and professional services, including vaccination, screening, and insurance coverage. Broader determinants of population health have received less attention, although this situation is rapidly changing. Against this backdrop, our specific contribution to the literature on ethics and law vis-à-vis promoting population health is to open up the ubiquitous presence of pets within cities and towns for further discussion. An expanding body of research suggests that pet animals are deeply relevant to people's health (negatively and positively). Pet bylaws adopted by town and city councils have largely escaped notice, yet they are meaningful to consider in relation to everyday practices, social norms, and cultural values, and thus in relation to population health. Nevertheless, not least because they pivot on defining pets as private property belonging to individual people, pet bylaws raise emotionally charged ethical issues that have yet to be tackled in any of the health research on pet ownership. The literature in moral philosophy on animals is vast, and we do not claim to advance this field here. Rather, we pragmatically seek to reconcile philosophical objections to pet ownership with both animal welfare and public health. In doing so, we foreground theorizations of personhood and property from sociocultural anthropology.

  3. Establishing a process of irradiating small animal brain using a CyberKnife and a microCT scanner

    International Nuclear Information System (INIS)

    Kim, Haksoo; Welford, Scott; Fabien, Jeffrey; Zheng, Yiran; Yuan, Jake; Brindle, James; Yao, Min; Lo, Simon; Wessels, Barry; Machtay, Mitchell; Sohn, Jason W.; Sloan, Andrew

    2014-01-01

    Purpose: Establish and validate a process of accurately irradiating small animals using the CyberKnife G4 System (version 8.5) with treatment plans designed to irradiate a hemisphere of a mouse brain based on microCT scanner images. Methods: These experiments consisted of four parts: (1) building a mouse phantom for intensity modulated radiotherapy (IMRT) quality assurance (QA), (2) proving usability of a microCT for treatment planning, (3) fabricating a small animal positioning system for use with the CyberKnife's image guided radiotherapy (IGRT) system, and (4)in vivo verification of targeting accuracy. A set of solid water mouse phantoms was designed and fabricated, with radiochromic films (RCF) positioned in selected planes to measure delivered doses. After down-sampling for treatment planning compatibility, a CT image set of a phantom was imported into the CyberKnife treatment planning system—MultiPlan (ver. 3.5.2). A 0.5 cm diameter sphere was contoured within the phantom to represent a hemispherical section of a mouse brain. A nude mouse was scanned in an alpha cradle using a microCT scanner (cone-beam, 157 × 149 pixels slices, 0.2 mm longitudinal slice thickness). Based on the results of our positional accuracy study, a planning treatment volume (PTV) was created. A stereotactic body mold of the mouse was “printed” using a 3D printer laying UV curable acrylic plastic. Printer instructions were based on exported contours of the mouse's skin. Positional reproducibility in the mold was checked by measuring ten CT scans. To verify accurate dose delivery in vivo, six mice were irradiated in the mold with a 4 mm target contour and a 2 mm PTV margin to 3 Gy and sacrificed within 20 min to avoid DNA repair. The brain was sliced and stained for analysis. Results: For the IMRT QA using a set of phantoms, the planned dose (6 Gy to the calculation point) was compared to the delivered dose measured via film and analyzed using Gamma analysis (3% and 3 mm). A

  4. Animal condition and drug effect on the results of F-18 FPCIT PET studies in mice

    International Nuclear Information System (INIS)

    Park, S. A.; Oh, S. J.; Kim, S. Y.; Lim, K. C.; Ryu, J. S.; Moon, D. H.; Kim, J. S.

    2007-01-01

    F-18 FPCIT is a useful radioligand in clinical research with PET for measuring dopamine transporter (DAT) densities in Parkinsonian patients. In animal model, however, the results of F-18 FPCIT PET studies can be compromised by imaging protocol and animal condition. We assessed the effect of animal condition and drug on the assessment of DAT binding and biodistribution of F-18 FPCIT in a mouse model. Normal C57BL/6 mice were imaged by small animal PET with 120 min dynamic acquisition protocol after intravenous injection of F-18 FPCIT (3.7 MBq). In reference condition, warming using a heating pad (38C) and general anesthesia using isoflurane (2%) during the uptake period (30 min) after the injection of FPCIT was performed. The impact of warming at room temperature (19C), anesthesia, and injection route on the biodistribution and DAT binding of F-18 FPCIT was evaluated (n=4 per group). The effect of fluvoxamine pretreatment (5, 20, 40, and 80 mg/kg), known inhibitor of specific serotonin reuptake site (SERT) and hepatic CYP1A2 isozyme, was also tested. Radioactivity of striatum, cerebral cortex, liver, and lung rapidly increased and then gradually decreased but bone activity progressively increased, resulting in 90-120 min bone activity (SUV = 1.50.2), hepatic activity (SUV=4.41.4), lung activity (SUV=0.30.0), and striatal specific binding ratio (SBR, 1.40.2) under reference condition. No warming with anesthesia did not increase SBR (1.30.3) but significantly reduced bone activity (SUV=0.90.2). Other conditions did not change SBR and bone activity. Pretreatment of fluvoxamine increased SBR (2.90.3 at 80mg/kg) and reduced bone activity (SUV=1.20.1 at 80mg/kg) of F-18 FPCIT with dose relationship (p<0.05). Animal condition during PET study influenced bone activity and specific DAT binding ratio of F-18 FPCIT. Fluvoxamine pretreatment, by reducing defluorination and cerebral SERT binding of F-18 FPCIT resulted in effective imaging of DAT in mice

  5. A 3D HIDAC-PET camera with sub-millimeter resolution for imaging small animals

    International Nuclear Information System (INIS)

    Jeavons, A.P.; Chandler, R.A.; Dettmar, C.A.R.

    1999-01-01

    A HIDAC-PET camera consisting essentially of 5 million 0.5 mm gas avalanching detectors has been constructed for small-animal imaging. The particular HIDAC advantage--a high 3D spatial resolution--has been improved to 0.95 mm fwhm and to 0.7 mm fwhm when reconstructing with 3D-OSEM methods incorporating resolution recovery. A depth-of-interaction resolution of 2.5 mm is implicit, due to the laminar construction. Scatter-corrected sensitivity, at 8.9 cps/kBq (i.e. 0.9%) from a central point source, or 7.2 cps/kBq (543 cps/kBq/cm 3 ) from a distributed (40 mm diameter, 60 mm long) source is now much higher than previous, and other, work. A field-of-view of 100 mm (adjustable to 200 mm) diameter by 210 mm axially permits whole-body imaging of small animals, containing typically 4MBqs of activity, at 40 kcps of which 16% are random coincidences, with a typical scatter fraction of 44%. Throughout the field-of-view there are no positional distortions and relative quantitation is uniform to ± 3.5%, but some variation of spatial resolution is found. The performance demonstrates that HIDAC technology is quite appropriate for small-animal PET cameras

  6. No Pet or Their Person Left Behind: Increasing the Disaster Resilience of Vulnerable Groups through Animal Attachment, Activities and Networks

    Science.gov (United States)

    Thompson, Kirrilly; Every, Danielle; Rainbird, Sophia; Cornell, Victoria; Smith, Bradley; Trigg, Joshua

    2014-01-01

    Simple Summary The potential for reconfiguring pet ownership from a risk factor to a protective factor for natural disaster survival has been recently proposed. But how might this resilience-building proposition apply to members of the community who are already considered vulnerable? This article addresses this important question by synthesizing information about what makes seven particular groups vulnerable, the challenges to increasing their resilience and how animals figure in their lives. It concludes that animal attachment could provide a novel conduit for accessing, communicating with and motivating vulnerable people to engage in resilience building behaviors that promote survival and facilitate recovery. Abstract Increased vulnerability to natural disasters has been associated with particular groups in the community. This includes those who are considered de facto vulnerable (children, older people, those with disabilities etc.) and those who own pets (not to mention pets themselves). The potential for reconfiguring pet ownership from a risk factor to a protective factor for natural disaster survival has been recently proposed. But how might this resilience-building proposition apply to vulnerable members of the community who own pets or other animals? This article addresses this important question by synthesizing information about what makes particular groups vulnerable, the challenges to increasing their resilience and how animals figure in their lives. Despite different vulnerabilities, animals were found to be important to the disaster resilience of seven vulnerable groups in Australia. Animal attachment and animal-related activities and networks are identified as underexplored devices for disseminating or ‘piggybacking’ disaster-related information and engaging vulnerable people in resilience building behaviors (in addition to including animals in disaster planning initiatives in general). Animals may provide the kind of innovative approach required

  7. Exploring the differences between pet and non-pet owners: Implications for human-animal interaction research and policy.

    Science.gov (United States)

    Saunders, Jessica; Parast, Layla; Babey, Susan H; Miles, Jeremy V

    2017-01-01

    There is conflicting evidence about whether living with pets results in better mental and physical health outcomes, with the majority of the empirical research evidence being inconclusive due to methodological limitations. We briefly review the research evidence, including the hypothesized mechanisms through which pet ownership may influence health outcomes. This study examines how pet and non-pet owners differ across a variety of socio-demographic and health measures, which has implications for the proper interpretation of a large number of correlational studies that attempt to draw causal attributions. We use a large, population-based survey from California administered in 2003 (n = 42,044) and find that pet owners and non-pet owners differ across many traits, including gender, age, race/ethnicity, living arrangements, and income. We include a discussion about how the factors associated with the selection into the pet ownership group are related to a range of mental and physical health outcomes. Finally, we provide guidance on how to properly model the effects of pet ownership on health to accurately estimate this relationship in the general population.

  8. Exploring the differences between pet and non-pet owners: Implications for human-animal interaction research and policy.

    Directory of Open Access Journals (Sweden)

    Jessica Saunders

    Full Text Available There is conflicting evidence about whether living with pets results in better mental and physical health outcomes, with the majority of the empirical research evidence being inconclusive due to methodological limitations. We briefly review the research evidence, including the hypothesized mechanisms through which pet ownership may influence health outcomes. This study examines how pet and non-pet owners differ across a variety of socio-demographic and health measures, which has implications for the proper interpretation of a large number of correlational studies that attempt to draw causal attributions. We use a large, population-based survey from California administered in 2003 (n = 42,044 and find that pet owners and non-pet owners differ across many traits, including gender, age, race/ethnicity, living arrangements, and income. We include a discussion about how the factors associated with the selection into the pet ownership group are related to a range of mental and physical health outcomes. Finally, we provide guidance on how to properly model the effects of pet ownership on health to accurately estimate this relationship in the general population.

  9. Symposium on Housing and Diseases of Rabbits, furbearing animals and pet animals

    NARCIS (Netherlands)

    Rommers, J.M.; Jong, de I.C.; Greef, de K.H.

    2015-01-01

    Within the Welfare Quality® project protocols have been developed to assess animal welfare on-farm in an objective, science based and practically applicable way. For various species like broilers and laying hens, sows and growing pigs, dairy cattle and veal calves, welfare assessment protocols have

  10. Evaluation of animal control measures on pet demographics in Santa Clara County, California, 1993–2006

    Science.gov (United States)

    Johnson, Karen L.; Weng, Hsin-Yi

    2013-01-01

    The measurable benefits of animal control programs are unknown and the aim of this study was to determine the impact of these programs on pet population changes. A prospective cross-sectional study of 1000 households was implemented in 2005 to evaluate characteristics of the owned and unowned population of dogs and cats in Santa Clara County, California. The same population was previously studied 12 years earlier. During this time period, the county instituted in 1994 and then subsequently disestablished a municipal spay/neuter voucher program for cats. Dog intakes declined from 1992–2005, as they similarly did for an adjacent county (San Mateo). However, cat intakes declined significantly more in Santa Clara County than San Mateo, with an average annual decline of approximately 700 cats for the 12 year period. Time series analysis showed a greater than expected decline in the number of cats surrendered to shelters in Santa Clara County during the years the voucher program was in effect (1994–2005). The net savings to the county by reducing the number of cat shelter intakes was estimated at approximately $1.5 million. The measurable benefits of animal control programs are unknown and the aim of this study was to determine the impact of these programs on pet population changes. PMID:23638352

  11. Evaluation of animal control measures on pet demographics in Santa Clara County, California, 1993–2006

    Directory of Open Access Journals (Sweden)

    Philip H. Kass

    2013-02-01

    Full Text Available The measurable benefits of animal control programs are unknown and the aim of this study was to determine the impact of these programs on pet population changes. A prospective cross-sectional study of 1000 households was implemented in 2005 to evaluate characteristics of the owned and unowned population of dogs and cats in Santa Clara County, California. The same population was previously studied 12 years earlier. During this time period, the county instituted in 1994 and then subsequently disestablished a municipal spay/neuter voucher program for cats. Dog intakes declined from 1992–2005, as they similarly did for an adjacent county (San Mateo. However, cat intakes declined significantly more in Santa Clara County than San Mateo, with an average annual decline of approximately 700 cats for the 12 year period. Time series analysis showed a greater than expected decline in the number of cats surrendered to shelters in Santa Clara County during the years the voucher program was in effect (1994–2005. The net savings to the county by reducing the number of cat shelter intakes was estimated at approximately $1.5 million. The measurable benefits of animal control programs are unknown and the aim of this study was to determine the impact of these programs on pet population changes.

  12. Micro-PET/CT approach with O-(2-[18F]fluorethyl)-L-tyrosine in experimental animal model of F98 Glioma for treatment planning

    OpenAIRE

    Menichetti, Luca; Pascali, Giancarlo; Petroni, Debora; Panetta, Daniele; Burchielli, Silvia; Daquino, G; Muzi, L; Cerullo, N; Cionini, Luca; Mazzini, M; Salvadori, Piero A

    2010-01-01

    The present study focuses on micro-PET/CT application to be used for a specific PET Boron Distribution Treatment Planning System (BDTPS) which integrates in the same frame micro-CT derived anatomy and PET radiotracer distribution. Preliminary results have demonstrated that 18F-FET PET allows the identification of the extent of cerebral lesions in our animal model. FET uptake was assessed in glioma implanted and sham operated animals. The FET-PET approach could lead to the assessment of the tr...

  13. Comprehensive small animal imaging strategies on a clinical 3 T dedicated head MR-scanner; adapted methods and sequence protocols in CNS pathologies.

    Directory of Open Access Journals (Sweden)

    Deepu R Pillai

    Full Text Available BACKGROUND: Small animal models of human diseases are an indispensable aspect of pre-clinical research. Being dynamic, most pathologies demand extensive longitudinal monitoring to understand disease mechanisms, drug efficacy and side effects. These considerations often demand the concomitant development of monitoring systems with sufficient temporal and spatial resolution. METHODOLOGY AND RESULTS: This study attempts to configure and optimize a clinical 3 Tesla magnetic resonance scanner to facilitate imaging of small animal central nervous system pathologies. The hardware of the scanner was complemented by a custom-built, 4-channel phased array coil system. Extensive modification of standard sequence protocols was carried out based on tissue relaxometric calculations. Proton density differences between the gray and white matter of the rodent spinal cord along with transverse relaxation due to magnetic susceptibility differences at the cortex and striatum of both rats and mice demonstrated statistically significant differences. The employed parallel imaging reconstruction algorithms had distinct properties dependent on the sequence type and in the presence of the contrast agent. The attempt to morphologically phenotype a normal healthy rat brain in multiple planes delineated a number of anatomical regions, and all the clinically relevant sequels following acute cerebral ischemia could be adequately characterized. Changes in blood-brain-barrier permeability following ischemia-reperfusion were also apparent at a later time. Typical characteristics of intra-cerebral haemorrhage at acute and chronic stages were also visualized up to one month. Two models of rodent spinal cord injury were adequately characterized and closely mimicked the results of histological studies. In the employed rodent animal handling system a mouse model of glioblastoma was also studied with unequivocal results. CONCLUSIONS: The implemented customizations including extensive

  14. High Resolution 125I Pinhole SPECT Imaging of the Mouse Thyroid With the MediSPECT Small Animal CdTe Scanner

    Science.gov (United States)

    Mettivier, Giovanni; Montesi, Maria Cristina; Curion, Assunta Simona; Lauria, Adele; Marotta, Marcello; Russo, Paolo

    2010-06-01

    The first in vivo tomographic 125I imaging of the mouse thyroid carried out with the new MediSPECT small animal SPECT scanner is presented. The scanner is based on a fine pitch CdTe semiconductor pixel detector (14 × 14 mm2, 256 × 256 square pixel with a 55 m side) and equipped with a set of high resolution collimators. The collimation and detection units of the scanner are mounted on a gantry, rotating around a horizontal axis, along which is placed the small animal housing. In an in vivo test, the mouse was injected with a Na125 I solution having a total activity of 31.8 MBq. The planar projections for SPECT reconstruction were acquired with a 300 m pinhole (magnification 1.47 and field of view of 9.6 × 9.6 mm2). The projections were captured in a step-and-shoot fashion and were processed with an Ordered Subsets-Expectation Maximization reconstruction algorithm in order to obtain the SPECT images. Several 125I imaging tests have been made by using phantoms to assess the detector spatial resolution. The measured spatial resolution with a 300 m pinhole is about 0.5 mm in planar imaging and better than 1 mm in tomographic imaging.

  15. 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.

  16. Accuracy and Radiation Dose of CT-Based Attenuation Correction for Small Animal PET: A Monte Carlo Simulation Study

    International Nuclear Information System (INIS)

    Yang, Ching-Ching; Chan, Kai-Chieh

    2013-06-01

    -Small animal PET allows qualitative assessment and quantitative measurement of biochemical processes in vivo, but the accuracy and reproducibility of imaging results can be affected by several parameters. The first aim of this study was to investigate the performance of different CT-based attenuation correction strategies and assess the resulting impact on PET images. The absorbed dose in different tissues caused by scanning procedures was also discussed to minimize biologic damage generated by radiation exposure due to PET/CT scanning. A small animal PET/CT system was modeled based on Monte Carlo simulation to generate imaging results and dose distribution. Three energy mapping methods, including the bilinear scaling method, the dual-energy method and the hybrid method which combines the kVp conversion and the dual-energy method, were investigated comparatively through assessing the accuracy of estimating linear attenuation coefficient at 511 keV and the bias introduced into PET quantification results due to CT-based attenuation correction. Our results showed that the hybrid method outperformed the bilinear scaling method, while the dual-energy method achieved the highest accuracy among the three energy mapping methods. Overall, the accuracy of PET quantification results have similar trend as that for the estimation of linear attenuation coefficients, whereas the differences between the three methods are more obvious in the estimation of linear attenuation coefficients than in the PET quantification results. With regards to radiation exposure from CT, the absorbed dose ranged between 7.29-45.58 mGy for 50-kVp scan and between 6.61-39.28 mGy for 80-kVp scan. For 18 F radioactivity concentration of 1.86x10 5 Bq/ml, the PET absorbed dose was around 24 cGy for tumor with a target-to-background ratio of 8. The radiation levels for CT scans are not lethal to the animal, but concurrent use of PET in longitudinal study can increase the risk of biological effects. The

  17. A useful PET probe [11C]BU99008 with ultra-high specific radioactivity for small animal PET imaging of I2-imidazoline receptors in the hypothalamus

    International Nuclear Information System (INIS)

    Kawamura, Kazunori; Shimoda, Yoko; Yui, Joji; Zhang, Yiding; Yamasaki, Tomoteru; Wakizaka, Hidekatsu; Hatori, Akiko; Xie, Lin; Kumata, Katsushi; Fujinaga, Masayuki; Ogawa, Masanao; Kurihara, Yusuke; Nengaki, Nobuki; Zhang, Ming-Rong

    2017-01-01

    Introduction: A positron emission tomography (PET) probe with ultra-high specific radioactivity (SA) enables measuring high receptor specific binding in brain regions by avoiding mass effect of the PET probe itself. It has been reported that PET probe with ultra-high SA can detect small change caused by endogenous or exogenous ligand. Recently, Kealey et al. developed [ 11 C]BU99008, a more potent PET probe for I 2 -imidazoline receptors (I 2 Rs) imaging, with a conventional SA (mean 76 GBq/μmol) showed higher specific binding in the brain. Here, to detect small change of specific binding for I 2 Rs caused by endogenous or exogenous ligand in an extremely small region, such as hypothalamus in the brain, we synthesized and evaluated [ 11 C]BU99008 with ultra-high SA as a useful PET probe for small-animal PET imaging of I 2 Rs. Methods: [ 11 C]BU99008 was prepared by [ 11 C]methylation of N-desmethyl precursor with [ 11 C]methyl iodide. Biodistribution, metabolite analysis, and brain PET studies were conducted in rats. Results: [ 11 C]BU99008 with ultra-high SA in the range of 5400–16,600 GBq/μmol were successfully synthesized (n = 7), and had appropriate radioactivity for in vivo study. In the biodistribution study, the mean radioactivity levels in all investigated tissues except for the kidney did not show significant difference between [ 11 C]BU99008 with ultra-high SA and that with conventional SA. In the metabolite analysis, the percentage of unchanged [ 11 C]BU99008 at 30 min after the injection of probes with ultra-high and conventional SA was similar in rat brain and plasma. In the PET study of rats' brain, radioactivity level (AUC 30–60 min ) in the hypothalamus of rats injected with [ 11 C]BU99008 with ultra-high SA (64 [SUV ∙ min]) was significantly higher than that observed for that with conventional SA (50 [SUV ∙ min]). The specific binding of [ 11 C]BU99008 with ultra-high SA (86% of total binding) for I 2 R was higher than that of

  18. Experimental MRI-SPECT insert system with Hybrid Semiconductor detectors Timepix for MR animal scanner Bruker 47/20

    Czech Academy of Sciences Publication Activity Database

    Zajíček, J.; Burian, M.; Soukup, P.; Novák, Vladimír; Macko, M.; Jakůbek, J.

    2017-01-01

    Roč. 12, January (2017), č. článku P01015. ISSN 1748-0221 Institutional support: RVO:68378297 Keywords : Gamma camera * SPECT * PET PET/CT * coronary CT angiography (CTA) * Gamma detectors (scintillators, CZT, HPG, HgI etc) * multi-modality systems * pixelated detectors and associated VLSI electronics Subject RIV: JB - Sensors, Measurment, Regulation OBOR OECD: Electrical and electronic engineering Impact factor: 1.220, year: 2016 http://iopscience.iop.org/article/10.1088/1748-0221/12/01/P01015

  19. Dynamic {sup 11}C-methionine PET analysis has an additional value for differentiating malignant tumors from granulomas: an experimental study using small animal PET

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Songji; Zhao, Yan [Hokkaido University, Department of Nuclear Medicine, Graduate School of Medicine, Sapporo (Japan); Hokkaido University, Department of Tracer Kinetics and Bioanalysis, Graduate School of Medicine, Sapporo (Japan); Kuge, Yuji; Hatano, Toshiyuki [Hokkaido University, Central Institute of Isotope Science, Sapporo (Japan); Yi, Min; Kohanawa, Masashi [Hokkaido University, Department of Advanced Medicine, Graduate School of Medicine, Sapporo (Japan); Magota, Keiichi; Tamaki, Nagara [Hokkaido University, Department of Nuclear Medicine, Graduate School of Medicine, Sapporo (Japan); Nishijima, Ken-ichi [Hokkaido University, Department of Molecular Imaging, Graduate School of Medicine, Sapporo (Japan)

    2011-10-15

    We evaluated whether the dynamic profile of L-{sup 11}C-methionine ({sup 11}C-MET) may have an additional value in differentiating malignant tumors from granulomas in experimental rat models by small animal positron emission tomography (PET). Rhodococcus aurantiacus and allogenic rat C6 glioma cells were inoculated, respectively, into the right and left calf muscles to generate a rat model bearing both granulomas and tumors (n = 6). Ten days after the inoculations, dynamic {sup 11}C-MET PET was performed by small animal PET up to 120 min after injection of {sup 11}C-MET. The next day, after overnight fasting, the rats were injected with {sup 18}F-2-deoxy-2-fluoro-D-glucose ({sup 18}F-FDG), and dynamic {sup 18}F-FDG PET was performed up to 180 min. The time-activity curves, static images, and mean standardized uptake value (SUV) in the lesions were calculated. {sup 11}C-MET uptake in the granuloma showed a slow exponential clearance after an initial distribution, while the uptake in the tumor gradually increased with time. The dynamic pattern of {sup 11}C-MET uptake in the granuloma was significantly different from that in the tumor (p < 0.001). In the static analysis of {sup 11}C-MET, visual assessment and SUV analysis could not differentiate the tumor from the granuloma in all cases, although the mean SUV in the granuloma (1.48 {+-} 0.09) was significantly lower than that in the tumor (1.72 {+-} 0.18, p < 0.01). The dynamic patterns, static images, and mean SUVs of {sup 18}F-FDG in the granuloma were similar to those in the tumor (p = NS). Dynamic {sup 11}C-MET PET has an additional value for differentiating malignant tumors from granulomatous lesions, which deserves further elucidation in clinical settings. (orig.)

  20. Development of Input Function Measurement System for Small Animal PET Study

    International Nuclear Information System (INIS)

    Kim, Jong Guk; Kim, Byung Su; Kim, Jin Su

    2010-01-01

    For quantitative measurement of radioactivity concentration in tissue and a validated tracer kinetic model, the high sensitive detection system has been required for blood sampling. With the accurate measurement of time activity curves (TACs) of labeled compounds in blood (plasma) enable to provide quantitative information on biological parameters of interest in local tissue. Especially, the development of new tracers for PET imaging requires knowledge of the kinetics of the tracer in the body and in arterial blood and plasma. Conventional approaches of obtaining an input function are to sample arterial blood sequentially by manual as a function of time. Several continuous blood sampling systems have been developed and used in nuclear medicine research field to overcome the limited temporal resolution in sampling by the conventional method. In this work, we developed the high sensitive and unique geometric design of GSO detector for small animal blood activity measurement

  1. Pet in the therapy room: an attachment perspective on Animal-Assisted Therapy.

    Science.gov (United States)

    Zilcha-Mano, Sigal; Mikulincer, Mario; Shaver, Phillip R

    2011-11-01

    John Bowlby's ( 1973, 1980, 1982) attachment theory is one of the most influential theories in personality and developmental psychology and provides insights into adjustment and psychopathology across the lifespan. The theory is also helpful in defining the target of change in psychotherapy, understanding the processes by which change occurs, and conceptualizing cases and planning treatment (Daniel, 2006; Obegi & Berant, 2008; Sable, 2004 ; Wallin, 2007). Here, we propose a model of Animal-Assisted Therapy (AAT) based on attachment theory and on the unique characteristics of human-pet relationships. The model includes clients' unmet attachment needs, individual differences in attachment insecurity, coping, and responsiveness to therapy. It also suggests ways to foster the development of more adaptive patterns of attachment and healthier modes of relating to others.

  2. Application of Molecular Tools for Gut Health of Pet Animals: A Review

    Directory of Open Access Journals (Sweden)

    Lipismita Samal

    2011-04-01

    Full Text Available Gut health is an important facet of well being of pet animals; it is in this context, various nutritional and biotechnological approaches have been proposed to manipulate the gut health by specifically targeting the colonic microbiota. Nutritional approaches include supplementation of antioxidants and phytochemicals like flavonoids, isoflavonoids and carotenoids. Biotechnological approaches include supplementation of probiotics, prebiotics, synbiotics in the diet and potential application of molecular tools like fluorescent in situ hybridization, denaturing gradient gel electrophoresis, quantitative dot blot hybridization, and restriction fragment length polymorphism etc. in studying the fecal microbiota composition. Post-genomic and related technologies, i.e. genomics, nutrigenomics, transcriptomics, proteomics, metabolomics and epigenomics in the study of gastrointestinal tract also put forward challenges for nutritionists and microbiologists to elucidate the complex interactions between gut microbiota and host.

  3. Choline molecular imaging with small-animal PET for monitoring tumor cellular response to photodynamic therapy of cancer

    Science.gov (United States)

    Fei, Baowei; Wang, Hesheng; Wu, Chunying; Meyers, Joseph; Xue, Liang-Yan; MacLennan, Gregory; Schluchter, Mark

    2009-02-01

    We are developing and evaluating choline molecular imaging with positron emission tomography (PET) for monitoring tumor response to photodynamic therapy (PDT) in animal models. Human prostate cancer (PC-3) was studied in athymic nude mice. A second-generation photosensitizer Pc 4 was used for PDT in tumor-bearing mice. MicroPET images with 11C-choline were acquired before PDT and 48 h after PDT. Time-activity curves of 11C-choline uptake were analyzed before and after PDT. For treated tumors, normalized choline uptake decreased significantly 48 h after PDT, compared to the same tumors pre-PDT (p PET imaging with 11C-choline is sensitive to detect early tumor response to PDT in the animal model of human prostate cancer.

  4. Evaluation of a virtual pet visit system with live video streaming of patient images over the Internet in a companion animal intensive care unit in the Netherlands

    NARCIS (Netherlands)

    Robben, Joris H.; Melsen, Diede N.; Almalik, Osama; Roomer, Wendy; Endenburg, Nienke

    2016-01-01

    Objective To evaluate the impact of a virtual pet visit system (“TelePet” System, TPS) on owners and staff of a companion animal ICU. Design Longitudinal interventional study (2010–2013). Setting Companion animal ICU at a university veterinary medical teaching hospital. Study Populations Pet owners,

  5. Single scan parameterization of space-variant point spread functions in image space via a printed array: the impact for two PET/CT scanners

    Energy Technology Data Exchange (ETDEWEB)

    Kotasidis, F A; Matthews, J C; Angelis, G I; Noonan, P J; Jackson, A [Imaging, Genomics and Proteomics, Wolfson Molecular Imaging Centre, MAHSC, University of Manchester, Manchester (United Kingdom); Price, P [Academic Department of Radiation Oncology, University of Manchester, Manchester (United Kingdom); Lionheart, W R [School of Mathematics, Alan Turing Building, University of Manchester, Manchester (United Kingdom); Reader, A J, E-mail: fotis.kotasidis@mmic.man.ac.uk [Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, QC (Canada)

    2011-05-21

    Incorporation of a resolution model during statistical image reconstruction often produces images of improved resolution and signal-to-noise ratio. A novel and practical methodology to rapidly and accurately determine the overall emission and detection blurring component of the system matrix using a printed point source array within a custom-made Perspex phantom is presented. The array was scanned at different positions and orientations within the field of view (FOV) to examine the feasibility of extrapolating the measured point source blurring to other locations in the FOV and the robustness of measurements from a single point source array scan. We measured the spatially-variant image-based blurring on two PET/CT scanners, the B-Hi-Rez and the TruePoint TrueV. These measured spatially-variant kernels and the spatially-invariant kernel at the FOV centre were then incorporated within an ordinary Poisson ordered subset expectation maximization (OP-OSEM) algorithm and compared to the manufacturer's implementation using projection space resolution modelling (RM). Comparisons were based on a point source array, the NEMA IEC image quality phantom, the Cologne resolution phantom and two clinical studies (carbon-11 labelled anti-sense oligonucleotide [{sup 11}C]-ASO and fluorine-18 labelled fluoro-l-thymidine [{sup 18}F]-FLT). Robust and accurate measurements of spatially-variant image blurring were successfully obtained from a single scan. Spatially-variant resolution modelling resulted in notable resolution improvements away from the centre of the FOV. Comparison between spatially-variant image-space methods and the projection-space approach (the first such report, using a range of studies) demonstrated very similar performance with our image-based implementation producing slightly better contrast recovery (CR) for the same level of image roughness (IR). These results demonstrate that image-based resolution modelling within reconstruction is a valid alternative to

  6. Photodynamic therapy of pet animals with spontaneously occurring head and neck carcinomas

    Science.gov (United States)

    Beck, Elsa R.; Hetzel, Fred W.

    1991-06-01

    Eleven pets with squamous cell carcinomas of the head and neck were treated with PDT using 3.0 mg/kg Photofrin II and a light dose of 300 J/cm2 at 632 nm. All tumors had measurable disease that was recurrent following at least one surgical removal. Ten of the eleven patients achieved a complete remission (CR). Of the ten animals with CR, two relapsed at 11 or 13 weeks while the other eight maintained their CR. Six animals remain disease free to the present time, with durations of 65, 56, 56, 56, 50 and 13 weeks. One died of unrelated causes at 12 weeks, and a second animal died of metastatic disease at 8 weeks. In these two cases, extensive histologic evaluation of the treated areas failed to demonstrate any evidence of residual tumor. Toxicity to the tumor bed or surrounding normal tissue was minimal. When the tumor was located adjacent to bone of the mandible or maxilla, the bone was at risk to form sequestra (in 3/5 cases). Based on these preliminary results, PDT may have applications for human patients with carcinoma of the head and neck.

  7. 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 ...

  8. Relationship between sources of pet acquisition and euthanasia of cats and dogs in an animal shelter: a pilot study.

    Science.gov (United States)

    Arbe Montoya, A I; Rand, J S; Greer, R M; Alberthsen, C; Vankan, D

    2017-06-01

    Approximately 140,000 unwanted dogs and cats are culled in Australia annually. There is a paucity of information linking sources of pet acquisition with subsequent euthanasia, which may inform evidence-based strategies to reduce euthanasia rates. This pilot study aimed to determine whether there is a higher risk of euthanasia related to the source of acquisition for pets surrendered to an animal shelter. Data for 5391 dogs and 5581 cats surrendered to one Queensland shelter between January 2006 and December 2009 were analysed. The main sources of acquisition for owner-surrendered dogs were 'shelter' and 'pet shop' and for owner-surrendered cats were 'own litter' and 'shelter'. Euthanasia rates for different sources varied. For adult dogs, acquisition through newspaper advertisements was associated with the highest euthanasia rate. Adult cats obtained as gifts (from friend or family member) had the highest euthanasia rate. For junior cats, the overwhelming source was the owner's own litter (68% of intake) and only kittens acquired as strays were at significantly higher risk of euthanasia. For both dogs and cats, animals acquired from shelters had lower rates of euthanasia than most other sources, which suggests that shelter-sourced animals may be considered a preferred source for pet acquisition to assist in reducing the number of adoptable pets euthanased. There was evidence from the study animal shelter that the risk of euthanasia was related to acquisition source. These findings should be confirmed by prospective studies, which should also investigate the interaction between acquisition source and other factors, using larger data sets from a variety of shelters. © 2017 Australian Veterinary Association.

  9. Anesthesia condition for {sup 18}F-FDG imaging of lung metastasis tumors using small animal PET

    Energy Technology Data Exchange (ETDEWEB)

    Woo, Sang-Keun; Lee, Tae Sup; Kim, Kyeong Min; Kim, June-Youp; Jung, Jae Ho; Kang, Joo Hyun [Division of Nuclear Medicine and RI Application, Korea Institute of Radiological and Medical Sciences (KIRAMS), Nowon-Gu, Seoul 139-706 (Korea, Republic of); Cheon, Gi Jeong [Division of Nuclear Medicine and RI Application, Korea Institute of Radiological and Medical Sciences (KIRAMS), Nowon-Gu, Seoul 139-706 (Korea, Republic of); Department of Nuclear Medicine, Korea Institute of Radiological and Medical Sciences (KIRAMS), Nowon-Gu, Seoul 139-706 (Korea, Republic of)], E-mail: larry@kcch.re.kr; Choi, Chang Woon; Lim, Sang Moo [Division of Nuclear Medicine and RI Application, Korea Institute of Radiological and Medical Sciences (KIRAMS), Nowon-Gu, Seoul 139-706 (Korea, Republic of); Department of Nuclear Medicine, Korea Institute of Radiological and Medical Sciences (KIRAMS), Nowon-Gu, Seoul 139-706 (Korea, Republic of)

    2008-01-15

    Small animal positron emission tomography (PET) with {sup 18}F-FDG has been increasingly used for tumor imaging in the murine model. The aim of this study was to establish the anesthesia condition for imaging of lung metastasis tumor using small animal {sup 18}F-FDG PET. Methods: To determine the impact of anesthesia on {sup 18}F-FDG distribution in normal mice, five groups were studied under the following conditions: no anesthesia, ketamine and xylazine (Ke/Xy), 0.5% isoflurane (Iso 0.5), 1% isoflurane (Iso 1) and 2% isoflurane (Iso 2). The ex vivo counting, standard uptake value (SUV) image and glucose SUV of {sup 18}F-FDG in various tissues were evaluated. The {sup 18}F-FDG images in the lung metastasis tumor model were obtained under no anesthesia, Ke/Xy and Iso 0.5, and registered with CT image to clarify the tumor region. Results: Blood glucose concentration and muscle uptake of {sup 18}F-FDG in the Ke/Xy group markedly increased more than in the other groups. The Iso 2 group increased {sup 18}F-FDG uptake in heart compared with the other groups. The Iso 0.5 anesthesized group showed the lowest {sup 18}F-FDG uptake in heart and chest wall. The small size of lung metastasis tumor (2 mm) was clearly visualized by {sup 18}F-FDG image with the Iso 0.5 anesthesia. Conclusion: Small animal {sup 18}F-FDG PET imaging with Iso 0.5 anesthesia was appropriate for the detection of lung metastasis tumor. To acquire {sup 18}F-FDG PET images with small animal PET, the type and level of anesthetic should be carefully considered to be suitable for the visualization of target tissue in the experimental model.

  10. 13N-ammonia myocardial perfusion imaging with a PET/CT scanner: impact on clinical decision making and cost-effectiveness

    International Nuclear Information System (INIS)

    Siegrist, Patrick T.; Husmann, Lars; Knabenhans, Martina; Gaemperli, Oliver; Valenta, Ines; Hoefflinghaus, Tobias; Scheffel, Hans; Stolzmann, Paul; Alkadhi, Hatem; Kaufmann, Philipp A.

    2008-01-01

    The purpose of the study is to determine the impact of 13 N-ammonia positron emission tomography (PET) myocardial perfusion imaging (MPI) on clinical decision making and its cost-effectiveness. One hundred consecutive patients (28 women, 72 men; mean age 60.9 ± 12.0 years; range 24-85 years) underwent 13 N-ammonia PET scanning (and computed tomography, used only for attenuation correction) to assess myocardial perfusion in patients with known (n = 79) or suspected (n = 8) coronary artery disease (CAD), or for suspected small-vessel disease (SVD; n = 13). Before PET, the referring physician was asked to determine patient treatment if PET would not be available. Four weeks later, PET patient management was reassessed for each patient individually. Before PET management strategies would have been: diagnostic angiography (62 of 100 patients), diagnostic angiography and percutaneous coronary intervention (PCI; 6 of 100), coronary artery bypass grafting (CABG; 3 of 100), transplantation (1 of 100), or conservative medical treatment (28 of 100). After PET scanning, treatment strategies were altered in 78 patients leading to: diagnostic angiography (0 of 100), PCI (20 of 100), CABG (3 of 100), transplantation (1 of 100), or conservative medical treatment (76 of 100). Patient management followed the recommendations of PET findings in 97% of the cases. Cost-effectiveness analysis revealed lower costs of EUR206/patient as a result of PET scanning. In a population with a high prevalence of known CAD, PET is cost-effective and has an important impact on patient management. (orig.)

  11. Comparison of strength of the human-animal bond between Hispanic and non-Hispanic owners of pet dogs and cats.

    Science.gov (United States)

    Schoenfeld-Tacher, Regina; Kogan, Lori R; Wright, Mary L

    2010-03-01

    To assess differences in strength of the human-animal bond between Hispanic and non-Hispanic owners and determine whether these variations were associated with differences in medical care for pets. Survey. 419 pet owners presenting a dog or cat for veterinary services at private veterinary clinics in Aurora, Colo; Chula Vista, Calif; and Mexico City. Procedures-Owner and pet demographic information was obtained via open-ended interview questions. The human-animal bond was assessed through the Lexington Attachment to Pets Scale. Pet health data were obtained from medical records for the specific visit observed, and a body condition score was assigned. Hispanics were more likely to own sexually intact dogs and cats as pets than were individuals of other race-ethnicity groups. Overall, owners were most likely to classify their pets as providing companionship. When data for the 2 US locations were examined separately, no significant difference existed between how non-Hispanic White and Hispanic owners viewed their pets, and scores for the Lexington Attachment to Pets Scale did not differ significantly among race-ethnicity groups. There was a strong human-animal bond among Hispanic respondents, and Hispanic pet owners in the United States and Mexico verbalized this attachment in similar ways to non-Hispanic White owners. There was no observed association between owner race-ethnicity and strength of the human-animal bond for Hispanic and non-Hispanic White pet owners in the United States. Thus, other factors must be considered to explain the observed difference in percentages of neutered animals between groups.

  12. Imaging of lung metastasis tumor mouse model using [{sup 18}F]FDG small animal PET and CT

    Energy Technology Data Exchange (ETDEWEB)

    Kim, June Youp; Woo, Sang Keun; Lee, Tae Sup [Korea Institute of Radiological and Medical Sciences (KIRAMS), Seoul (Korea, Republic of)] (and others)

    2007-02-15

    The purpose of this study is to image metastaic lung melanoma model with optimal pre-conditions for animal handling by using [{sup 18}F]FDG small animal PET and clinical CT. The pre-conditions for lung region tumor imaging were 16-22 h fasting and warming temperature at 30 .deg. C. Small animal PET image was obtained at 60 min postinjection of 7.4 MBq [{sup 18}F]FDG and compared pattern of [{sup 18}F]FDG uptake and glucose standard uptake value (SUVG) of lung region between Ketamine/Xylazine (Ke/Xy) and Isoflurane (Iso) anesthetized group in normal mice. Metastasis tumor mouse model to lung was established by intravenous injection of B16-F10 cells in C57BL/6 mice. In lung metastasis tumor model, [{sup 18}F]FDG image was obtained and fused with anatomical clinical CT image. Average blood glucose concentration in normal mice were 128.0 {+-} 22.87 and 86.0 {+-} 21.65 mg/dL in Ke/Xy group and Iso group, respectively. Ke/Xy group showed 1.5 fold higher blood glucose concentration than Iso group. Lung to Background ratio (L/B) in SUVG image was 8.6 {+-} 0.48 and 12.1 {+-}0.63 in Ke/Xy group and Iso group, respectively. In tumor detection in lung region, [{sup 18}F]FDG image of Iso group was better than that of Ke/Xy group, because of high L/B ratio. Metastatic tumor location in [{sup 18}F]FDG small animal PET image was confirmed by fusion image using clinical CT. Tumor imaging in small animal lung region with [{sup 18}F]FDG small animal PET should be considered pre-conditions which fasting, warming and an anesthesia during [{sup 18}F]FDG uptake. Fused imaging with small animal PET and CT image could be useful for the detection of metastatic tumor in lung region.

  13. Automated computer quantification of breast cancer in small-animal models using PET-guided MR image co-segmentation.

    Science.gov (United States)

    Bagci, Ulas; Kramer-Marek, Gabriela; Mollura, Daniel J

    2013-07-05

    Care providers use complementary information from multiple imaging modalities to identify and characterize metastatic tumors in early stages and perform surveillance for cancer recurrence. These tasks require volume quantification of tumor measurements using computed tomography (CT) or magnetic resonance imaging (MRI) and functional characterization through positron emission tomography (PET) imaging. In vivo volume quantification is conducted through image segmentation, which may require both anatomical and functional images available for precise tumor boundary delineation. Although integrating multiple image modalities into the segmentation process may improve the delineation accuracy and efficiency, due to variable visibility on image modalities, complex shape of metastatic lesions, and diverse visual features in functional and anatomical images, a precise and efficient segmentation of metastatic breast cancer remains a challenging goal even for advanced image segmentation methods. In response to these challenges, we present here a computer-assisted volume quantification method for PET/MRI dual modality images using PET-guided MRI co-segmentation. Our aims in this study were (1) to determine anatomical tumor volumes automatically from MRI accurately and efficiently, (2) to evaluate and compare the accuracy of the proposed method with different radiotracers (18F-Z HER2-Affibody and 18F-flourodeoxyglucose (18F-FDG)), and (3) to confirm the proposed method's determinations from PET/MRI scans in comparison with PET/CT scans. After the Institutional Administrative Panel on Laboratory Animal Care approval was obtained, 30 female nude mice were used to construct a small-animal breast cancer model. All mice were injected with human breast cancer cells and HER2-overexpressing MDA-MB-231HER2-Luc cells intravenously. Eight of them were selected for imaging studies, and selected mice were imaged with MRI, CT, and 18F-FDG-PET at weeks 9 and 10 and then imaged with 18F-Z HER2

  14. PET/CT alignment calibration with a non-radioactive phantom and the intrinsic {sup 176}Lu radiation of PET detector

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Qingyang [School of Automation and Electrical Engineering, University of Science & Technology Beijing, Beijing 100083 (China); Ma, Tianyu; Wang, Shi; Liu, Yaqiang [Department of Engineering Physics, Tsinghua University, Beijing 100084 (China); Gu, Yu, E-mail: guyu@ustb.edu.cn [School of Automation and Electrical Engineering, University of Science & Technology Beijing, Beijing 100083 (China); Dai, Tiantian, E-mail: maxinedtt@163.com [Department of Radiation Oncology, China-Japan Friendship Hospital, Beijing 100029 (China)

    2016-11-01

    Positron emission tomography/computed tomography (PET/CT) is an important tool for clinical studies and pre-clinical researches which provides both functional and anatomical images. To achieve high quality co-registered PET/CT images, alignment calibration of PET and CT scanner is a critical procedure. The existing methods reported use positron source phantoms imaged both by PET and CT scanner and then derive the transformation matrix from the reconstructed images of the two modalities. In this paper, a novel PET/CT alignment calibration method with a non-radioactive phantom and the intrinsic {sup 176}Lu radiation of the PET detector was developed. Firstly, a multi-tungsten-alloy-sphere phantom without positron source was designed and imaged by CT and the PET scanner using intrinsic {sup 176}Lu radiation included in LYSO. Secondly, the centroids of the spheres were derived and matched by an automatic program. Lastly, the rotation matrix and the translation vector were calculated by least-square fitting of the centroid data. The proposed method was employed in an animal PET/CT system (InliView-3000) developed in our lab. Experimental results showed that the proposed method achieves high accuracy and is feasible to replace the conventional positron source based methods.

  15. Pet Allergy

    Science.gov (United States)

    ... an allergic reaction to proteins found in an animal's skin cells, saliva or urine. Signs of pet allergy ... Allergens from cats and dogs are found in skin cells the animals shed (dander), as well as in their saliva, ...

  16. Calibration test of PET scanners in a multi-centre clinical trial on breast cancer therapy monitoring using 18F-FLT.

    Directory of Open Access Journals (Sweden)

    Francis Bouchet

    Full Text Available A multi-centre trial using PET requires the analysis of images acquired on different systems We designed a multi-centre trial to estimate the value of 18F-FLT-PET to predict response to neoadjuvant chemotherapy in patients with newly diagnosed breast cancer. A calibration check of each PET-CT and of its peripheral devices was performed to evaluate the reliability of the results.11 centres were investigated. Dose calibrators were assessed by repeated measurements of a 68Ge certified source. The differences between the clocks associated with the dose calibrators and inherent to the PET systems were registered. The calibration of PET-CT was assessed with an homogeneous cylindrical phantom by comparing the activities per unit of volume calculated from the dose calibrator measurements with that measured on 15 Regions of Interest (ROIs drawn on 15 consecutive slices of reconstructed filtered back-projection (FBP images. Both repeatability of activity concentration based upon the 15 ROIs (ANOVA-test and its accuracy were evaluated.There was no significant difference for dose calibrator measurements (median of difference -0.04%; min = -4.65%; max = +5.63%. Mismatches between the clocks were less than 2 min in all sites and thus did not require any correction, regarding the half life of 18F. For all the PET systems, ANOVA revealed no significant difference between the activity concentrations estimated from the 15 ROIs (median of difference -0.69%; min = -9.97%; max = +9.60%.No major difference between the 11 centres with respect to calibration and cross-calibration was observed. The reliability of our 18F-FLT multi-centre clinical trial was therefore confirmed from the physical point of view. This type of procedure may be useful for any clinical trial involving different PET systems.

  17. Farm Fairs and Petting Zoos: A Review of Animal Contact as a Source of Zoonotic Enteric Disease.

    Science.gov (United States)

    Conrad, Cheyenne C; Stanford, Kim; Narvaez-Bravo, Claudia; Callaway, Todd; McAllister, Tim

    2017-02-01

    Many public venues such as farms, fairs, and petting zoos encourage animal contact for both educational and entertainment purposes. However, healthy farm animals, including cattle, small ruminants, and poultry, can be reservoirs for enteric zoonotic pathogens, with human infections resulting in nausea, vomiting, diarrhea, and, in some cases, severe complications that can lead to death. As animals shed these organisms in their feces, contamination of themselves and their surroundings is unavoidable. The majority of North Americans reside in urban and suburban settings, and the general public often possess limited knowledge of agricultural practices and minimal contact with farm animals. Furthermore, there is a lack of understanding of zoonotic pathogens, particularly how these pathogens are spread and the human behaviors that may increase the risk of infection. Human risk behaviors include hand-to-mouth contact immediately after physical contact with animals and their environments, a practice that facilitates the ingestion of pathogens. It is often young children who become ill due to their under-developed immune systems and poorer hygienic practices compared with adults, such as more frequent hand-to-mouth behaviors, and infrequent or improper hand washing. These illnesses are often preventable, simply through adequate hygiene and hand washing. Our objective was to use a structured approach to review the main causal organisms responsible for human illnesses acquired in petting zoo and open farm environments, Shiga toxin-producing Escherichia coli, nontyphoidal Salmonella, Campylobacter, and Cryptosporidium. Notable outbreaks involving direct contact with farm animals and farm, fair, or petting zoo environments are discussed and recommendations for how public venues can increase safety and hand hygiene compliance among visitors are proposed. The most effective protective measures against enteric illnesses include education of the public, increasing overall awareness

  18. Improving PET Quantification of Small Animal [68Ga]DOTA-Labeled PET/CT Studies by Using a CT-Based Positron Range Correction.

    Science.gov (United States)

    Cal-Gonzalez, Jacobo; Vaquero, Juan José; Herraiz, Joaquín L; Pérez-Liva, Mailyn; Soto-Montenegro, María Luisa; Peña-Zalbidea, Santiago; Desco, Manuel; Udías, José Manuel

    2018-01-19

    Image quality of positron emission tomography (PET) tracers that emits high-energy positrons, such as Ga-68, Rb-82, or I-124, is significantly affected by positron range (PR) effects. PR effects are especially important in small animal PET studies, since they can limit spatial resolution and quantitative accuracy of the images. Since generators accessibility has made Ga-68 tracers wide available, the aim of this study is to show how the quantitative results of [ 68 Ga]DOTA-labeled PET/X-ray computed tomography (CT) imaging of neuroendocrine tumors in mice can be improved using positron range correction (PRC). Eighteen scans in 12 mice were evaluated, with three different models of tumors: PC12, AR42J, and meningiomas. In addition, three different [ 68 Ga]DOTA-labeled radiotracers were used to evaluate the PRC with different tracer distributions: [ 68 Ga]DOTANOC, [ 68 Ga]DOTATOC, and [ 68 Ga]DOTATATE. Two PRC methods were evaluated: a tissue-dependent (TD-PRC) and a tissue-dependent spatially-variant correction (TDSV-PRC). Taking a region in the liver as reference, the tissue-to-liver ratio values for tumor tissue (TLR tumor ), lung (TLR lung ), and necrotic areas within the tumors (TLR necrotic ) and their respective relative variations (ΔTLR) were evaluated. All TLR values in the PRC images were significantly different (p effect more remarkable for the TDSV-PRC method, with relative differences respect to no PRC: ΔTLR lung  = - 45 ± 24 (TD-PRC), - 55 ± 18 (TDSV-PRC). TLR necrotic values also decreased when using PRC, with more noticeable differences for TD-PRC: ΔTLR necrotic  = - 52 ± 6 (TD-PRC), - 48 ± 8 (TDSV-PRC). The PRC methods proposed provide a significant quantitative improvement in [ 68 Ga]DOTA-labeled PET/CT imaging of mice with neuroendocrine tumors, hence demonstrating that these techniques could also ameliorate the deleterious effect of the positron range in clinical PET imaging.

  19. A computational pipeline for quantification of pulmonary infections in small animal models using serial PET-CT imaging.

    Science.gov (United States)

    Bagci, Ulas; Foster, Brent; Miller-Jaster, Kirsten; Luna, Brian; Dey, Bappaditya; Bishai, William R; Jonsson, Colleen B; Jain, Sanjay; Mollura, Daniel J

    2013-07-23

    Infectious diseases are the second leading cause of death worldwide. In order to better understand and treat them, an accurate evaluation using multi-modal imaging techniques for anatomical and functional characterizations is needed. For non-invasive imaging techniques such as computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET), there have been many engineering improvements that have significantly enhanced the resolution and contrast of the images, but there are still insufficient computational algorithms available for researchers to use when accurately quantifying imaging data from anatomical structures and functional biological processes. Since the development of such tools may potentially translate basic research into the clinic, this study focuses on the development of a quantitative and qualitative image analysis platform that provides a computational radiology perspective for pulmonary infections in small animal models. Specifically, we designed (a) a fast and robust automated and semi-automated image analysis platform and a quantification tool that can facilitate accurate diagnostic measurements of pulmonary lesions as well as volumetric measurements of anatomical structures, and incorporated (b) an image registration pipeline to our proposed framework for volumetric comparison of serial scans. This is an important investigational tool for small animal infectious disease models that can help advance researchers' understanding of infectious diseases. We tested the utility of our proposed methodology by using sequentially acquired CT and PET images of rabbit, ferret, and mouse models with respiratory infections of Mycobacterium tuberculosis (TB), H1N1 flu virus, and an aerosolized respiratory pathogen (necrotic TB) for a total of 92, 44, and 24 scans for the respective studies with half of the scans from CT and the other half from PET. Institutional Administrative Panel on Laboratory Animal Care approvals were

  20. A new electronic read-out for the YAPPET scanner

    CERN Document Server

    Damiani, C; Malaguti, R; Guerra, A D; Domenico, G D; Zavattini, G

    2002-01-01

    A small animal PET-SPECT scanner (YAPPET) prototype was built at the Physics Department of the Ferrara University and is presently being used at the Nuclear Medicine Department for radiopharmaceutical studies on rats. The first YAPPET prototype shows very good performances, but needs some improvements before it can be fully used for intensive radiopharmaceutical research. The main problem of the actual prototype is its heavy electronics, based on NIM and CAMAC standard modules. For this reason a new, compact read-out electronics was developed and tested. The results of a first series of tests made on the first prototype will be presented in the paper.

  1. Critically appraised topic on adverse food reactions of companion animals (5): discrepancies between ingredients and labeling in commercial pet foods.

    Science.gov (United States)

    Olivry, Thierry; Mueller, Ralf S

    2018-01-22

    Elimination dietary trials for the diagnosis of adverse food reactions (food allergies) in dogs and cats are often conducted with commercial pet foods while relying on their label to select those not containing previously-eaten ingredients. There are concerns that industrial pet foods might contain unlisted food sources that could negate the usefulness of performing food trials. Furthermore, unidentified ingredients might cause clinical reactions in patients hypersensitive to such items. We searched two article databases on July 7, 2017 and January 12, 2018 for relevant articles, and we screened abstracts from the leading international veterinary dermatology congresses for suitable material. Additional citations were found in the selected papers. In all, we extracted data from 17 articles and one abstract. The studies varied both in the number of pet foods tested (median: 15; range: 1 to 210) and that of ingredients specifically evaluated (median: 4; range: 1 to 11). Studies most often employed either PCR to detect DNA or ELISA to identify proteins from one or more vegetal or animal species; two studies used mass spectrometry to increase the number of detectable proteins. The various methods found ingredients that were not on the label in 0 to 83% (median: 45%) of tested diets; this percentage varied between 33 and 83% in pet foods with "novel/limited" ingredients proposed for elimination diets. Similarly, ingredients were found to be missing from the label in 0 to 38% (median: 1%) of tested foods. Finally, six studies evaluated, among others, several hydrolysate-containing pet foods: mislabeling with unlabeled or missing ingredients was found only in one diet. The mislabeling of pet foods appears rather common, even in those with "novel" or "limited" ingredients proposed for elimination diets. Unexpected added ingredients are more frequently detected than those missing from the label. There is insufficient information to determine if the presence of a

  2. Use of Radioactive Ion Beams for Biomedical Research 2. in-vivo dosimetry using positron emitting rare earth isotopes with the rotating prototype PET scanner at the Geneva Cantonal Hospital

    CERN Multimedia

    2002-01-01

    % IS331 \\\\ \\\\ The use of radioactive metal ions (such as $^{90}$Y, $^{153}$Sm or $^{186}$Re) in cancer therapy has made some progress, but has been hampered by factors that could be addressed at CERN with a greater likelihood of success than at any other installation in the world. The present proposal seeks to use the unique advantage of CERN ISOLDE to get round these problems together with the PET scanners at the Cantonal Hospital Geneva (PET~=~positron emission tomography). Radioisotope production by spallation at ISOLDE makes available a complete range of isotopes having as complete a diversity of types and energy of radiation, of half-life, and of ionic properties as one would wish. Among these isotopes several positron-emitters having clinical relevance are available.\\\\ \\\\Some free rare earth chelatas are used presently in palliation of painful bone metastases. Curative effects are not able for the moment with this kind of radiopharmaceuticals. More and better data on the biokinetics and bio-distribution...

  3. Small animal PET imaging of HSV1-tk gene expression with {sup 124}IVDU in liver by the hydrodynamic injection

    Energy Technology Data Exchange (ETDEWEB)

    Song, I. H.; Lee, T. S.; Woo, S. G.; Jeong, J. H.; Kang, J. H.; Kim, K. M.; Chun, K. J.; Choi, C. W.; Lim, S. M. [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

    2007-07-01

    The liver is an important target organ for gene transfer due to its capacity for synthesizing serum protein and its involvement in numerous genetic diseases. High level of foreign gene expression in liver can be achieved by a large-volume and high-speed intravenous injection of naked plasmid DNA (pDNA), so called hydrodynamic injection. This study is aimed to evaluate liver specific-gene expression of herpes simplex virus type 1 thymidine kinase(HSV1-tk) by hydrodynamic injection and image HSV1-tk expression using {sup 124}IVDU-PET. We constructed herpes simplex virus type 1 thymidine kinase (HSV1-tk)-expressing pDNA (pHSV1-tk) modified from pEGFP-N1. Hydrodynamic injection was performed using 40 {mu}g of plasmid (pEGFP/N1 or pHSV1-tk) in 2 ml of 0.85% saline solution for 20{approx}22g mice in 5 seconds intravenously. At 1 d post-hydrodynamic injection, biodistribution study was performed at 2 h post-injection of radiolabeled IVDU, fluorescence image was obtained using optical imager and small animal PET image was acquired with {sup 124}IVDU at 2 h post-injection. After PET imaging, digital whole body autoradiography (DWBA) was performed. Expression of HSV1-tk and EGFP was confirmed by RT-PCR in each liver tissue. In liver of pHSV1-tk and pEGFP/N1 injection groups, {sup 123}IVDU uptake was 5.65%ID/g and 0.98%ID/g, respectively. {sup 123}IVDU uptake in liver of pHSV1-tk injection group showed 5.7-fold higher than that of pEGFP/N1 injection group (p<0.01). On the other hand, the liver of pEGFP/N1 injection group showed fluorescence activity. In small animal PET images, {sup 124}IVDU uptake was selectively localized in liver of pHSV1-tk injection group and also checked in DWBA, but showed minimal uptake in liver of pEGFP/N1 injection mice. Hydrodynamic injection was effective to liver-specific delivery of plasmid DNA. Small animal PET image of {sup 124}IVDU could be used in the evaluation of noninvasive reporter gene imaging in liver.

  4. Leptospirosis and Pets

    Science.gov (United States)

    ... Bacterial Special Pathogens Branch (BSPB) BSPB Laboratory Submissions Pets Recommend on Facebook Tweet Share Compartir Leptospirosis is ... that can affect human and animals, including your pets. All animals can potentially become infected with Leptospirosis. ...

  5. Monte Carlo simulations in multi-detector CT (MDCT) for two PET/CT scanner models using MASH and FASH adult phantoms

    Energy Technology Data Exchange (ETDEWEB)

    Belinato, W., E-mail: wbfisica@gmail.com [Bahia Federal Institute of Education, Science and Technology – IFBA, Vitória da Conquista, 45.100-000 (Brazil); Department of Physics, Federal University of Sergipe – UFS, São Cristóvão, 49.100-000 (Brazil); Santos, W.S. [Department of Physics, Federal University of Sergipe – UFS, São Cristóvão, 49.100-000 (Brazil); Paschoal, C.M.M., E-mail: cinthiam.paschoal@gmail.com [Department of Civil Engineering, Vale do Acarau State University – UVA, Sobral 62.040-730 (Brazil); Souza, D.N. [Department of Physics, Federal University of Sergipe – UFS, São Cristóvão, 49.100-000 (Brazil)

    2015-06-01

    The combination of positron emission tomography (PET) and computed tomography (CT) has been extensively used in oncology for diagnosis and staging of tumors, radiotherapy planning and follow-up of patients with cancer, as well as in cardiology and neurology. This study determines by the Monte Carlo method the internal organ dose deposition for computational phantoms created by multidetector CT (MDCT) beams of two PET/CT devices operating with different parameters. The different MDCT beam parameters were largely related to the total filtration that provides a beam energetic change inside the gantry. This parameter was determined experimentally with the Accu-Gold Radcal measurement system. The experimental values of the total filtration were included in the simulations of two MCNPX code scenarios. The absorbed organ doses obtained in MASH and FASH phantoms indicate that bowtie filter geometry and the energy of the X-ray beam have significant influence on the results, although this influence can be compensated by adjusting other variables such as the tube current–time product (mAs) and pitch during PET/CT procedures.

  6. A focus group study of veterinarians' and pet owners' perceptions of veterinarian-client communication in companion animal practice.

    Science.gov (United States)

    Coe, Jason B; Adams, Cindy L; Bonnett, Brenda N

    2008-10-01

    To compare veterinarians' and pet owners' perceptions of client expectations with respect to veterinarian-client communication and to identify related barriers and challenges to communication. Qualitative study based on focus group interviews. 6 pet owner focus groups (32 owners) and 4 veterinarian focus groups (24 companion animal veterinarians). Independent focus group sessions were conducted with standardized open-ended questions and follow-up probes. Content analysis was performed on transcripts of the focus group discussions. Five themes related to veterinarian-client communication were identified: educating clients (ie, explaining important information, providing information up front, and providing information in various forms), providing choices (ie, providing pet owners with a range of options, being respectful of owners' decisions, and working in partnership with owners), using 2-way communication (ie, using language clients understand, listening to what clients have to say, and asking the right questions), breakdowns in communication that affected the client's experience (ie, owners feeling misinformed, that they had not been given all options, and that their concerns had not been heard), and challenges veterinarians encountered when communicating with clients (ie, monetary concerns, client misinformation, involvement of > 1 client, and time limitations). Results suggested that several factors are involved in providing effective veterinarian-client communication and that breakdowns in communication can have an adverse effect on the veterinarian-client relationship.

  7. Demonstration of an Axial PET concept for brain and small animal imaging

    CERN Document Server

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

    2011-01-01

    Standard Positron Emission Tomography (PET) cameras need to reach a compromise between spatial resolution and sensitivity. To overcome this limitation we developed a novel concept of PET. Our AX-PET demonstrator is made of LYSO crystals aligned along the z coordinate (patient's axis) and WLS strips orthogonally placed with respect to the crystals. This concept offers full 3D localization of the photon interaction inside the camera. Thus the spatial resolution and the sensitivity can be simultaneously improved and the reconstruction of Compton interactions inside the detector is also possible. Moreover, by means of G-APDs for reading out the photons, both from LYSO and WLS, the detector is insensitive to magnetic fields and it is then suitable to be used in a combined PET/MRI apparatus. A complete Monte Carlo simulation and dedicated reconstruction software have been developed. The two final modules, each composed of 48 crystals and 156 WLS strips, have been built and fully characterized in a dedicated test se...

  8. Small animal practice: billing, third-party payment options, and pet health insurance.

    Science.gov (United States)

    Dunn, Louise

    2006-03-01

    Rising veterinary costs can keep some people from accepting necessary medical care for their pets. This article discusses viable alternative financing options. Each alternative comes with its own pros and cons. Practice owners will want to study the offerings carefully to find the best match for their practice and clients.

  9. PET Evidence of the Effect of Donepezil on Cognitive Performance in an Animal Model of Chemobrain

    Directory of Open Access Journals (Sweden)

    Ilhan Lim

    2016-01-01

    Full Text Available A considerable number of patients with breast cancer complain of cognitive impairment after chemotherapy. In this study, we showed that donepezil enhanced memory function and increased brain glucose metabolism in a rat model of cognitive impairment after chemotherapy using behavioral analysis and positron emission tomography (PET. We found that chemotherapy affected spatial learning ability, reference memory, and working memory and that donepezil improved these cognitive impairments. According to PET analysis, chemotherapy reduced glucose metabolism in the medial prefrontal cortex and hippocampus, and donepezil increased glucose metabolism in the bilateral frontal lobe, parietal lobe, and hippocampus. Reduced glucose metabolism was more prominent after treatment with doxorubicin than cyclophosphamide. Our results demonstrated the neural mechanisms for cognitive impairment after chemotherapy and show that cognition was improved after donepezil intervention using both behavioral and imaging methods. Our results suggested that donepezil can be employed clinically for the treatment of cognitive deficits after chemotherapy.

  10. Optimization of an ultralow-dose high-resolution pediatric PET scanner design based on monolithic scintillators with dual-sided digital SiPM readout: a simulation study

    Science.gov (United States)

    Mikhaylova, Ekaterina; Tabacchini, Valerio; Borghi, Giacomo; Mollet, Pieter; D’Hoe, Ester; Schaart, Dennis R.; Vandenberghe, Stefaan

    2017-11-01

    The goal of this simulation study is the performance evaluation and comparison of six potential designs for a time-of-flight PET scanner for pediatric patients of up to about 12 years of age. It is designed to have a high sensitivity and provide high-contrast and high-resolution images. The simulated pediatric PET is a full ring scanner, consisting of 32  ×  32 mm2 monolithic LYSO:Ce crystals coupled to digital silicon photomultiplier arrays. The six considered designs differ in axial lengths (27.2 cm, 54.4 cm and 102 cm) and crystal thicknesses (22 mm and 11 mm). The simulations are based on measured detector response data. We study two possible detector arrangements: 22 mm-thick crystals with dual-sided readout and 11 mm-thick crystals with back-sided readout. The six designs are simulated by means of the GEANT4 application for tomographic emission software, using the measured spatial, energy and time response of the monolithic scintillator detectors as input. The performance of the six designs is compared on the basis of four studies: (1) spatial resolution; (2) NEMA NU2-2012 sensitivity and scatter fraction (SF) tests; (3) non-prewhitening signal-to-noise ratio observer study; and (4) receiver operating characteristics analysis. Based on the results, two designs are identified as cost-effective solutions for fast and efficient imaging of children: one with 54.4 cm axial field-of-view (FOV) and 22 mm-thick crystals, and another one with 102 cm axial FOV and 11 cm-thick crystals. The first one has a higher center point sensitivity than the second one, but requires dual-sided readout. The second design has the advantage of allowing a whole-body scan in a single bed position acquisition. Both designs have the potential to provide an excellent spatial resolution (∼2 mm) and an ultra-high sensitivity (>100 cps kBq-1 ).

  11. Resolution, sensitivity and precision with autoradiography and small animal positron emission tomography: implications for functional brain imaging in animal research

    International Nuclear Information System (INIS)

    Schmidt, Kathleen C.; Smith, Carolyn Beebe

    2005-01-01

    Quantitative autoradiographic methods for in vivo measurement of regional rates of cerebral blood flow, glucose metabolism, and protein synthesis contribute significantly to our understanding of physiological and biochemical responses of the brain to changes in the environment. A disadvantage of these autoradiographic methods is that experimental animals can be studied only once. With the advent of small animal positron emission tomography (PET) and with increases in the sensitivity and spatial resolution of scanners it is now possible to use adaptations of these methods in experimental animals with PET. These developments allow repeated studies of the same animal, including studies of the same animal under different conditions, and longitudinal studies. In this review we summarize the tradeoffs between the use of autoradiography and small animal PET for functional brain imaging studies in animal research

  12. Impact of demographic characteristics in pet ownership: modeling animal count according to owners income and age.

    Science.gov (United States)

    Martins, Camila Marinelli; Mohamed, Ahmed; Guimarães, Ana Marcia Sá; de Barros, Cristiane da Conceição; Pampuch, Raquel Dos Santos; Svoboda, Walfrido; Garcia, Rita de Cassia Maria; Ferreira, Fernando; Biondo, Alexander Welker

    2013-05-01

    Pet owner characteristics such as age, gender, income/social class, marital status, rural/urban residence and household type have been shown to be associated with the number of owned pets. However, few studies to date have attempted to evaluate these associations in Brazil. Accordingly, the aim of this study was to evaluate the association between age and income of owners and the number of owned dogs and cats in a Brazilian urban center. Pinhais, metropolitan area of Curitiba, Southern Brazil, the seventh largest city in Brazil, was chosen for this study. Questionnaires were administered door-to-door between January and February 2007 and data were analyzed by zero-inflated negative binomial (ZINB) models. A total of 13,555 of 30,380 (44.62%) households were interviewed. The majority (62.43%) of households reported having one or more dogs, with one or two dogs being the most common (29.97% and 19.71%, respectively). Cat ownership per household was much lower (P=0.001) than dog ownership, with 90% of the households reported having no owned cats. ZINB analyses indicated that income is not associated with the number of both dogs and cats among households that have pets. However, households from higher income categories were more likely to have dogs (but not cats) when compared to the lowest income category (Ppets. Certain age categories were significantly associated with the number of dogs or cats in households that have pets. In addition, most age categories were significantly associated with having dogs and/or cats (Ppets; higher income households were more likely to have dogs when compared to low-income households. Copyright © 2012 Elsevier B.V. All rights reserved.

  13. Accuracy and reproducibility of tumor positioning during prolonged and multi-modality animal imaging studies

    International Nuclear Information System (INIS)

    Zhang Mutian; Huang Minming; Le, Carl; Zanzonico, Pat B; Ling, C Clifton; Koutcher, Jason A; Humm, John L; Claus, Filip; Kolbert, Katherine S; Martin, Kyle

    2008-01-01

    Dedicated small-animal imaging devices, e.g. positron emission tomography (PET), computed tomography (CT) and magnetic resonance imaging (MRI) scanners, are being increasingly used for translational molecular imaging studies. The objective of this work was to determine the positional accuracy and precision with which tumors in situ can be reliably and reproducibly imaged on dedicated small-animal imaging equipment. We designed, fabricated and tested a custom rodent cradle with a stereotactic template to facilitate registration among image sets. To quantify tumor motion during our small-animal imaging protocols, 'gold standard' multi-modality point markers were inserted into tumor masses on the hind limbs of rats. Three types of imaging examination were then performed with the animals continuously anesthetized and immobilized: (i) consecutive microPET and MR images of tumor xenografts in which the animals remained in the same scanner for 2 h duration, (ii) multi-modality imaging studies in which the animals were transported between distant imaging devices and (iii) serial microPET scans in which the animals were repositioned in the same scanner for subsequent images. Our results showed that the animal tumor moved by less than 0.2-0.3 mm over a continuous 2 h microPET or MR imaging session. The process of transporting the animal between instruments introduced additional errors of ∼0.2 mm. In serial animal imaging studies, the positioning reproducibility within ∼0.8 mm could be obtained.

  14. Automatic cardiac gating of small-animal PET from list-mode data

    Energy Technology Data Exchange (ETDEWEB)

    Herraiz, J.L.; Udias, J.M. [Universidad Complutense de Madrid Univ. (Spain). Grupo de Fisica Nuclear; Vaquero, J.J.; Desco, M. [Universidad Carlos III de Madrid (Spain). Dept. de Bioingenieria e Ingenieria Aeroespacial; Cusso, L. [Hospital General Universitario Gregorio Maranon, Madrid (Spain). Unidad de Medicina y Cirugia Experimental

    2011-07-01

    This work presents a method to obtain automatically the cardiac gating signal in a PET study of rats, by employing the variation with time of the counts in the cardiac region, that can be extracted from list-mode data. In an initial step, the cardiac region is identified in the image space by backward-projecting a small fraction of the acquired data and studying the variation with time of the counts in each voxel inside said region, with frequencies within 2 and 8 Hz. The region obtained corresponds accurately to the left-ventricle of the heart of the rat. In a second step, the lines-of-response (LORs) connected with this region are found by forward-projecting this region. The time variation of the number of counts in these LORs contains the cardiac motion information that we want to extract. This variation of counts with time is band-pass filtered to reduce noise, and the time signal so obtained is used to create the gating signal. The result was compared with a cardiac gating signal obtained from an ECG acquired simultaneously to the PET study. Reconstructed gated images obtained from both gating information are similar. The method proposed demonstrates that valid cardiac gating signals can be obtained for rats from PET list-mode data. (orig.)

  15. PET/CT Imaging in Mouse Models of Myocardial Ischemia

    Directory of Open Access Journals (Sweden)

    Sara Gargiulo

    2012-01-01

    Full Text Available Different species have been used to reproduce myocardial infarction models but in the last years mice became the animals of choice for the analysis of several diseases, due to their short life cycle and the possibility of genetic manipulation. Many techniques are currently used for cardiovascular imaging in mice, including X-ray computed tomography (CT, high-resolution ultrasound, magnetic resonance imaging, and nuclear medicine procedures. Cardiac positron emission tomography (PET allows to examine noninvasively, on a molecular level and with high sensitivity, regional changes in myocardial perfusion, metabolism, apoptosis, inflammation, and gene expression or to measure changes in anatomical and functional parameters in heart diseases. Currently hybrid PET/CT scanners for small laboratory animals are available, where CT adds high-resolution anatomical information. This paper reviews mouse models of myocardial infarction and discusses the applications of dedicated PET/CT systems technology, including animal preparation, anesthesia, radiotracers, and images postprocessing.

  16. Malassezia spp. dan Peranannya sebagai Penyebab Dermatitis pada Hewan Peliharaan (MALASSEZIA SPP AND ITS ROLE AS THE CAUSAL AGENT OF DERMATITIS IN PET ANIMALS)

    OpenAIRE

    Pradipta Nuri Adiyati; Eko Sugeng Pribadi

    2015-01-01

    Malassezia is dimorphic yeast found normally in the animal healthy skin. Malassezia can causehealth problem in pet animals, such as dogs, cats, and other domestic animals. Varies according itsvirulence, Malassezia can cause skin changes characterized by severe pruritus, yellowish erythema andscab, greasy skin, bad odor with hyperpigmentation and lichenification in the face, paws, and neck bottom,as well as belly. Laboratory diagnosis can be performed either by microscopic examination of nativ...

  17. Hybrid image and blood sampling input function for quantification of small animal dynamic PET data

    International Nuclear Information System (INIS)

    Shoghi, Kooresh I.; Welch, Michael J.

    2007-01-01

    We describe and validate a hybrid image and blood sampling (HIBS) method to derive the input function for quantification of microPET mice data. The HIBS algorithm derives the peak of the input function from the image, which is corrected for recovery, while the tail is derived from 5 to 6 optimally placed blood sampling points. A Bezier interpolation algorithm is used to link the rightmost image peak data point to the leftmost blood sampling point. To assess the performance of HIBS, 4 mice underwent 60-min microPET imaging sessions following a 0.40-0.50-mCi bolus administration of 18 FDG. In total, 21 blood samples (blood-sampled plasma time-activity curve, bsPTAC) were obtained throughout the imaging session to compare against the proposed HIBS method. MicroPET images were reconstructed using filtered back projection with a zoom of 2.75 on the heart. Volumetric regions of interest (ROIs) were composed by drawing circular ROIs 3 pixels in diameter on 3-4 transverse planes of the left ventricle. Performance was characterized by kinetic simulations in terms of bias in parameter estimates when bsPTAC and HIBS are used as input functions. The peak of the bsPTAC curve was distorted in comparison to the HIBS-derived curve due to temporal limitations and delay in blood sampling, which affected the rates of bidirectional exchange between plasma and tissue. The results highlight limitations in using bsPTAC. The HIBS method, however, yields consistent results, and thus, is a substitute for bsPTAC

  18. Small-animal PET imaging of the type 1 and type 2 cannabinoid receptors in a photothrombotic stroke model

    Energy Technology Data Exchange (ETDEWEB)

    Vandeputte, Caroline; Casteels, Cindy; Koole, Michel; Gerits, Anneleen [KU Leuven, Division of Nuclear Medicine, Leuven (Belgium); KU Leuven, Molecular Small Animal Imaging Center, MoSAIC, Leuven (Belgium); Struys, Tom [Hasselt University, Laboratory of Histology, Biomedical Research Institute, Hasselt (Belgium); KU Leuven, Biomedical NMR Unit, Leuven (Belgium); Veghel, Daisy van; Evens, Nele; Bormans, Guy [KU Leuven, Molecular Small Animal Imaging Center, MoSAIC, Leuven (Belgium); KU Leuven, Laboratory of Radiopharmacy, Leuven (Belgium); Dresselaers, Tom; Himmelreich, Uwe [KU Leuven, Molecular Small Animal Imaging Center, MoSAIC, Leuven (Belgium); KU Leuven, Biomedical NMR Unit, Leuven (Belgium); Lambrichts, Ivo [Hasselt University, Laboratory of Histology, Biomedical Research Institute, Hasselt (Belgium); Laere, Koen van [KU Leuven, Division of Nuclear Medicine, Leuven (Belgium); KU Leuven, Molecular Small Animal Imaging Center, MoSAIC, Leuven (Belgium); UZ Leuven, Division of Nuclear Medicine, Leuven (Belgium)

    2012-11-15

    Recent ex vivo and pharmacological evidence suggests involvement of the endocannabinoid system in the pathophysiology of stroke, but conflicting roles for type 1 and 2 cannabinoid receptors (CB{sub 1} and CB{sub 2}) have been suggested. The purpose of this study was to evaluate CB{sub 1} and CB{sub 2} receptor binding over time in vivo in a rat photothrombotic stroke model using PET. CB{sub 1} and CB{sub 2} microPET imaging was performed at regular time-points up to 2 weeks after stroke using [{sup 18}F]MK-9470 and [{sup 11}C]NE40. Stroke size was measured using MRI at 9.4 T. Ex vivo validation was performed via immunostaining for CB{sub 1} and CB{sub 2}. Immunofluorescent double stainings were also performed with markers for astrocytes (GFAP) and macrophages/microglia (CD68). [{sup 18}F]MK-9470 PET showed a strong increase in CB{sub 1} binding 24 h and 72 h after stroke in the cortex surrounding the lesion, extending to the insular cortex 24 h after surgery. These alterations were consistently confirmed by CB{sub 1} immunohistochemical staining. [{sup 11}C]NE40 did not show any significant differences between stroke and sham-operated animals, although staining for CB{sub 2} revealed minor immunoreactivity at 1 and 2 weeks after stroke in this model. Both CB{sub 1} {sup +} and CB{sub 2} {sup +} cells showed minor immunoreactivity for CD68. Time-dependent and regionally strongly increased CB{sub 1}, but not CB{sub 2}, binding are early consequences of photothrombotic stroke. Pharmacological interventions should primarily aim at CB{sub 1} signalling as the role of CB{sub 2} seems minor in the acute and subacute phases of stroke. (orig.)

  19. Small-Animal Imaging Using Clinical Positron Emission Tomography/Computed Tomography and Super-Resolution

    Directory of Open Access Journals (Sweden)

    Frank P. DiFilippo

    2012-05-01

    Full Text Available Considering the high cost of dedicated small-animal positron emission tomography/computed tomography (PET/CT, an acceptable alternative in many situations might be clinical PET/CT. However, spatial resolution and image quality are of concern. The utility of clinical PET/CT for small-animal research and image quality improvements from super-resolution (spatial subsampling were investigated. National Electrical Manufacturers Association (NEMA NU 4 phantom and mouse data were acquired with a clinical PET/CT scanner, as both conventional static and stepped scans. Static scans were reconstructed with and without point spread function (PSF modeling. Stepped images were postprocessed with iterative deconvolution to produce super-resolution images. Image quality was markedly improved using the super-resolution technique, avoiding certain artifacts produced by PSF modeling. The 2 mm rod of the NU 4 phantom was visualized with high contrast, and the major structures of the mouse were well resolved. Although not a perfect substitute for a state-of-the-art small-animal PET/CT scanner, a clinical PET/CT scanner with super-resolution produces acceptable small-animal image quality for many preclinical research studies.

  20. A micro-PET/CT approach using O-(2-[{sup 18}F]fluoroethyl)-L-tyrosine in an experimental animal model of F98 glioma for BNCT

    Energy Technology Data Exchange (ETDEWEB)

    Menichetti, L., E-mail: luca.menichetti@ifc.cnr.it [CNR Institute of Clinical Physiology, Pisa (Italy); Petroni, D.; Panetta, D. [CNR Institute of Clinical Physiology, Pisa (Italy); Burchielli, S. [Fondazione CNR/Regione Toscana G. Monasterio, Pisa (Italy); Bortolussi, Silva [Dept. Theoretical and Nuclear Physics, University of Pavia, Pavia (Italy); Matteucci, M. [Scuola Superiore Sant' Anna, Pisa (Italy); Pascali, G.; Del Turco, S. [CNR Institute of Clinical Physiology, Pisa (Italy); Del Guerra, A. [Department of Physics, University of Pisa, Pisa (Italy); Altieri, S. [Dept. Theoretical and Nuclear Physics, University of Pavia, Pavia (Italy); Salvadori, P.A. [CNR Institute of Clinical Physiology, Pisa (Italy)

    2011-12-15

    The present study focuses on a micro-PET/CT application to be used for experimental Boron Neutron Capture Therapy (BNCT), which integrates, in the same frame, micro-CT derived anatomy and PET radiotracer distribution. Preliminary results have demonstrated that {sup 18}F-fluoroethyl-tyrosine (FET)/PET allows the identification of the extent of cerebral lesions in F98 tumor bearing rat. Neutron autoradiography and {alpha}-spectrometry on axial tissues slices confirmed the tumor localization and extraction, after the administration of fructose-boronophenylalanine (BPA). Therefore, FET-PET approach can be used to assess the transport, the net influx, and the accumulation of FET, as an aromatic amino acid analog of BPA, in experimental animal model. Coregistered micro-CT images allowed the accurate morphological localization of the radiotracer distribution and its potential use for experimental BNCT.

  1. An overview of the use of pigs in PET research

    DEFF Research Database (Denmark)

    Alstrup, Aage Kristian Olsen

    Current interest in studying molecular processes as they occur in the living organism has accelerated the use of laboratory animals for imaging of novel radiolabeled compounds. In particular, PET has contributed to the development of radiolabeled compounds for assessing molecular processes....... The dynamics of PET typically require a relatively large organ size and blood supply in order to properly evaluate radioligand binding kinetics. To fulfil these requirements, pigs have often been used in such studies. At least four factors have contributed to the ever-growing interest in using pigs for PET...... imaging. First, a wealth of information has become available concerning similarities of physiologic and pathologic processes in pigs and humans. Second, the size of most pig organs permits studies to be carried out in PET scanners otherwise designed for human use. Third, multiple blood samples can...

  2. The Combination of In vivo (124)I-PET and CT Small Animal Imaging for Evaluation of Thyroid Physiology and Dosimetry.

    Science.gov (United States)

    El-Ali, Henrik H; Eckerwall, Martin; Skovgaard, Dorthe; Larsson, Erik; Strand, Sven-Erik; Kjaer, Andreas

    2012-06-05

    A thyroid rat model combining functional and anatomical information would be of great benefit for better modeling of thyroid physiology and for absorbed dose calculations. Our aim was to show that (124)I-PET and CT small animal imaging are useful as a combined model for studying thyroid physiology and dose calculation. Seven rats were subjects for multiple thyroid (124)I-imaging and CT-scans. S-values [mGy/MBqs] for different thyroid sizes were simulated. A phantom with spheres was designed for validation of performances of the small animal PET and CT imaging systems. Small animal image-based measurements of the activity amount and the volumes of the spheres with a priori known volumes showed a good agreement with their corresponding actual volumes. The CT scans of the rats showed thyroid volumes from 34-70 mL. The wide span in volumes of thyroid glands indicates the importance of using an accurate volume-measuring technique such as the small animal CT. The small animal PET system was on the other hand able to accurately estimate the activity concentration in the thyroid volumes. We conclude that the combination of the PET and CT image information is essential for quantitative thyroid imaging and accurate thyroid absorbed dose calculation.

  3. The Combination of In vivo 124I-PET and CT Small Animal Imaging for Evaluation of Thyroid Physiology and Dosimetry

    Directory of Open Access Journals (Sweden)

    Henrik H. El-Ali

    2012-06-01

    Full Text Available Objective: A thyroid rat model combining functional and anatomical information would be of great benefit for better modeling of thyroid physiology and for absorbed dose calculations. Our aim was to show that 124I-PET and CT small animal imaging are useful as a combined model for studying thyroid physiology and dose calculation. Methods: Seven rats were subjects for multiple thyroid 124I-imaging and CT-scans. S-values [mGy/MBqs] for different thyroid sizes were simulated. A phantom with spheres was designed for validation of performances of the small animal PET and CT imaging systems. Results: Small animal image-based measurements of the activity amount and the volumes of the spheres with a priori known volumes showed a good agreement with their corresponding actual volumes. The CT scans of the rats showed thyroid volumes from 34–70 mL. Conclusions: The wide span in volumes of thyroid glands indicates the importance of using an accurate volume-measuring technique such as the small animal CT. The small animal PET system was on the other hand able to accurately estimate the activity concentration in the thyroid volumes. We conclude that the combination of the PET and CT image information is essential for quantitative thyroid imaging and accurate thyroid absorbed dose calculation.

  4. Positron emission tomography (PET) study of the alterations in brain pharmacokinetics of methamphetamine in methamphetamine sensitized animals

    International Nuclear Information System (INIS)

    Nakamura, Hitoshi

    2001-01-01

    I investigated the differences in brain pharmacokinetics of [ 11 C]methamphetamine ([ 11 C]MAP) in normal and MAP sensitized animals using positron emission tomography (PET). [ 11 C]MAP was synthesized by an automated on-line [ 11 C]methylation system. I newly produced MAP sensitized dog and monkey by repeated MAP treatment. The maximal level of accumulation of [ 11 C]MAP in the sensitized dog brain was 1.4 times higher than that in the control. This result suggests the changes in the pharmacokinetic profile of MAP in the brain affect the development or expression of MAP-induced behavioral sensitization. However, the overaccumulation of [ 11 C]MAP in the sensitized monkey brain was not observed due to the influence of anesthesia. (author)

  5. Evaluation of anesthesia effects on [18F]FDG uptake in mouse brain and heart using small animal PET

    International Nuclear Information System (INIS)

    Toyama, Hiroshi; Ichise, Masanori; Liow, Jeih-San; Vines, Douglass C.; Seneca, Nicholas M.; Modell, Kendra J.; Seidel, Jurgen; Green, Michael V.; Innis, Robert B.

    2004-01-01

    This study evaluates effects of anesthesia on 18 F-FDG (FDG) uptake in mouse brain and heart to establish the basic conditions of small animal PET imaging. Prior to FDG injection, 12 mice were anesthetized with isoflurane gas; 11 mice were anesthetized with an intraperitoneal injection of a ketamine/xylazine mixture; and 11 mice were awake. In isoflurane and ketamine/xylazine conditions, FDG brain uptake (%ID/g) was significantly lower than in controls. Conversely, in the isoflurane condition, %ID/g in heart was significantly higher than in controls, whereas heart uptake in ketamine/xylazine mice was significantly lower. Results suggest that anesthesia impedes FDG uptake in mouse brain and affects FDG uptake in heart; however, the effects in the brain and heart differ depending on the type of anesthesia used

  6. Evaluation of anesthesia effects on [{sup 18}F]FDG uptake in mouse brain and heart using small animal PET

    Energy Technology Data Exchange (ETDEWEB)

    Toyama, Hiroshi E-mail: htoyama@fujita-hu.ac.jp; Ichise, Masanori; Liow, Jeih-San; Vines, Douglass C.; Seneca, Nicholas M.; Modell, Kendra J.; Seidel, Jurgen; Green, Michael V.; Innis, Robert B

    2004-02-01

    This study evaluates effects of anesthesia on {sup 18}F-FDG (FDG) uptake in mouse brain and heart to establish the basic conditions of small animal PET imaging. Prior to FDG injection, 12 mice were anesthetized with isoflurane gas; 11 mice were anesthetized with an intraperitoneal injection of a ketamine/xylazine mixture; and 11 mice were awake. In isoflurane and ketamine/xylazine conditions, FDG brain uptake (%ID/g) was significantly lower than in controls. Conversely, in the isoflurane condition, %ID/g in heart was significantly higher than in controls, whereas heart uptake in ketamine/xylazine mice was significantly lower. Results suggest that anesthesia impedes FDG uptake in mouse brain and affects FDG uptake in heart; however, the effects in the brain and heart differ depending on the type of anesthesia used.

  7. Positron emission tomography (PET) study of the alterations in brain pharmacokinetics of methamphetamine in methamphetamine sensitized animals

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Hitoshi [Tohoku Univ., Sendai (Japan). Hospital

    2001-08-01

    I investigated the differences in brain pharmacokinetics of [{sup 11}C]methamphetamine ([{sup 11}C]MAP) in normal and MAP sensitized animals using positron emission tomography (PET). [{sup 11}C]MAP was synthesized by an automated on-line [{sup 11}C]methylation system. I newly produced MAP sensitized dog and monkey by repeated MAP treatment. The maximal level of accumulation of [{sup 11}C]MAP in the sensitized dog brain was 1.4 times higher than that in the control. This result suggests the changes in the pharmacokinetic profile of MAP in the brain affect the development or expression of MAP-induced behavioral sensitization. However, the overaccumulation of [{sup 11}C]MAP in the sensitized monkey brain was not observed due to the influence of anesthesia. (author)

  8. 78 FR 57227 - Animal Welfare; Retail Pet Stores and Licensing Exemptions

    Science.gov (United States)

    2013-09-18

    ..., and transportation of animals covered by the AWA. Part 2 requires most dealers to be licensed by APHIS... requirements governing the humane handling, care, treatment, and transportation of certain animals by dealers... registries there is one other breeder that has not been identified who also uses remote marketing methods...

  9. Parents' acceptance and their children's choice of pet for animal-assisted therapy (A.A.T.) in 3- to 12-year-old children in the dental operatory -A questionnaire-based pilot study.

    Science.gov (United States)

    Gupta, Nidhi; Yadav, Tushar

    2018-04-16

    To evaluate the parents' acceptance to therapy pets, child's most favoured pet, child's choice of soft toy as compared to live pet, and child's preference of his own pet versus therapy pet. Sixty-two children of age groups 3-6 year, 6-9 year, and 9-12 year were selected. The data from completed questionnaires were statistically analysed and subjected to z test, Chi-squared test with P valueAnimal-Assisted Therapy (AAT) can prove to be a good behaviour management technique if more parents are made aware and informed about AAT; dog is one of the highly recommended pets for AAT, and therapy pet should be preferred over home pet. © 2018 BSPD, IAPD and John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  10. Battered pets and domestic violence: animal abuse reported by women experiencing intimate violence and by nonabused women.

    Science.gov (United States)

    Ascione, Frank R; Weber, Claudia V; Thompson, Teresa M; Heath, John; Maruyama, Mika; Hayashi, Kentaro

    2007-04-01

    Women residing at domestic violence shelters (S group) were nearly 11 times more likely to report that their partner had hurt or killed pets than a comparison group of women who said they had not experienced intimate violence (NS group). Reports of threatened harm to pets were more than 4 times higher for the S group. Using the Conflict Tactics Scale, the authors demonstrated that severe physical violence was a significant predictor of pet abuse. The vast majority of shelter women described being emotionally close to their pets and distraught by the abuse family pets experienced. Children were often exposed to pet abuse, and most reported being distressed by these experiences. A substantial minority of S-group women reported that their concern for their pets' welfare prevented them from seeking shelter sooner. This seemed truer for women without children, who may have had stronger pet attachments. This obstacle to seeking safety should be addressed by domestic violence agencies.

  11. Early life exposures to home dampness, pet ownership and farm animal contact and neuropsychological development in 4 year old children: a prospective birth cohort study.

    NARCIS (Netherlands)

    Casas, L.; Torrent, M.; Zock, J.P.; Doekes, G.; Forns, J.; Guxens, M.; Täubel, M.; Heinrich, J.; Sunyer, J.

    2013-01-01

    Exposure to biocontaminants is associated with behavioural problems and poorer cognitive function. Our study assesses the associations between early life exposure to home dampness, pets and farm animal contact and cognitive function and social competences in 4-year old children, and the associations

  12. Assessment of a chemically induced model of lung squamous cell carcinoma in mice by 18F-FDG small-animal PET.

    Science.gov (United States)

    Ambrosini, Valentina; Nanni, Cristina; Pettinato, Cinzia; Fini, Milena; D'Errico, Antonia; Trepidi, Silvia; Spinelli, Antonello; Al-Nahhas, Adil; Rubello, Domenico; Zompatori, Maurizio; Fabbri, Mario; Franchi, Roberto; Fanti, Stefano

    2007-08-01

    Small-animal imaging has become a relevant research field in pre-clinical oncology. In particular, metabolic information provided by small-animal positron emission tomography (PET) is very useful to closely monitor tumour growth and assess therapy response in murine models of human disease. There are various murine models for human lung adenocarcinoma, but those for squamous cell lung carcinoma, the most common form of human cancer, are lacking. To assess the feasibility of 18F-FDG small-animal PET to monitor tumour growth in a chemically induced model of squamous cell carcinoma of the lung. Nineteen NIH Swiss mice were skin painted by N-nitroso-tris-chloroethylurea (NTCU) twice a week, with a 3 day interval, for 8 months and 10 NIH Swiss mice skin painted with NTCU solvent (acetone) were used as controls. 18F-FDG PET was performed under sevofluorane anaesthesia and oxygen supplementation at 2, 4, 6 and 8 months from initial treatment. Images were assessed by visual analysis and semi-quantitatively. When a diffuse distribution of tumour was noted, the mean of the counts/pixel measured at three lung levels, corrected for the effective dose injected and for decay, was used for comparison between mutagen-painted and control mice. Pathological evaluation was carried out from the time of the first positive PET results in a subgroup of the whole population to assess correlation with PET findings. Small animal CT was performed at 8 months in another subgroup. In both terms of visual analysis and measurement of total lung activity, 18F-FDG PET at 2 and 4 months from initial treatment were comparable in mutagen-painted and controls. At 6 months, PET images showed a faint and diffuse uptake over both lung fields in mutagen-painted mice with multiple focal areas of increased tracer uptake that merged into confluent masses at 8 months and seriously subverting lung architecture on computed tomography. Total lung activity was significantly higher in mutagen-painted versus

  13. Effects of repeated petting sessions on leukocyte counts, intestinal parasite prevalence, and plasma cortisol concentration of dogs housed in a county animal shelter.

    Science.gov (United States)

    Dudley, Emily S; Schiml, Patricia A; Hennessy, Michael B

    2015-12-01

    To describe changes in WBC counts, plasma cortisol concentration, and fecal parasite shedding of dogs housed in an animal shelter and determine the effects of daily petting sessions on these variables. Hybrid prospective observational and experimental study. 92 healthy dogs newly arrived to an animal shelter and 15 healthy privately owned dogs (control group). Blood and fecal samples were collected from shelter dogs 1, 3, and 10 days after arrival and from control dogs once. A subset of shelter dogs (n = 15) was assigned to receive 30 minutes of petting daily. Plasma cortisol concentration was measured, CBCs were performed, and fecal samples were evaluated for parasite ova. For shelter dogs, total leukocyte, neutrophil, and lymphocyte counts increased significantly between days 1 and 10, with less consistent increases in monocyte count and neutrophil-to-lymphocyte count ratio. Parasite shedding was unaffected by duration of shelter stay but was greater for shelter versus control dogs. For shelter dogs, plasma cortisol concentration decreased with time and was higher than that of control dogs on each day. Total leukocyte, neutrophil, and monocyte counts and neutrophil-to-lymphocyte count ratios were also higher for shelter versus control dogs. Petting sessions resulted in a decrease in plasma cortisol concentration but in no other variables. Large increasing immunologic responses, heavy parasite shedding, and high but decreasing plasma cortisol concentration were identified in shelter dogs. Daily 30-minute petting sessions affected only cortisol values, so the clinical importance of petting for immunologic and other health outcomes remains unclear.

  14. Performance comparison of Si-PM-based block detectors with different pixel sizes for an ultrahigh-resolution small-animal PET system

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Seiichi [Kobe City College of Technology, Kobe (Japan); Watabe, Hiroshi; Hatazawa, Jun, E-mail: s-yama@kobe-kosen.ac.jp [Department of Molecular Imaging in Medicine, Osaka University Graduate School of Medicine, Osaka (Japan)

    2011-10-21

    The silicon photomultiplier (Si-PM) is a promising photodetector for a high-resolution PET scanner due to its small size, high gain and lower sensitivity to magnetic fields. There are several commercially available Si-PM arrays with different pixel sizes and fill factors, and these parameters can affect the performance of a PET block detector read out by these devices. We compared the performance of block detectors using 4 x 4 Si-PM arrays with 25 {mu}m (Hamamatsu S11064-025P) and 50 {mu}m (S11064-050P) pixels combined with the same 15 x 15 matrix LGSO block made of 0.7 x 0.7 x 6 mm{sup 3} scintillator pixels. Evaluated characteristics include photopeak linearity, energy resolution and positioning performance. Although the photopeak linearity and energy resolution are slightly better for the Si-PM with 25 {mu}m pixels, the position performance measured by the separation of the position histogram is significantly better for the Si-PM with 50 {mu}m pixels. We conclude that using the Si-PM with 50 {mu}m pixels will provide a better solution for the development of ultrahigh-resolution PET systems. (note)

  15. Performance comparison of Si-PM-based block detectors with different pixel sizes for an ultrahigh-resolution small-animal PET system

    International Nuclear Information System (INIS)

    Yamamoto, Seiichi; Watabe, Hiroshi; Hatazawa, Jun

    2011-01-01

    The silicon photomultiplier (Si-PM) is a promising photodetector for a high-resolution PET scanner due to its small size, high gain and lower sensitivity to magnetic fields. There are several commercially available Si-PM arrays with different pixel sizes and fill factors, and these parameters can affect the performance of a PET block detector read out by these devices. We compared the performance of block detectors using 4 x 4 Si-PM arrays with 25 μm (Hamamatsu S11064-025P) and 50 μm (S11064-050P) pixels combined with the same 15 x 15 matrix LGSO block made of 0.7 x 0.7 x 6 mm 3 scintillator pixels. Evaluated characteristics include photopeak linearity, energy resolution and positioning performance. Although the photopeak linearity and energy resolution are slightly better for the Si-PM with 25 μm pixels, the position performance measured by the separation of the position histogram is significantly better for the Si-PM with 50 μm pixels. We conclude that using the Si-PM with 50 μm pixels will provide a better solution for the development of ultrahigh-resolution PET systems. (note)

  16. Image reconstruction for the ClearPET{sup TM} Neuro

    Energy Technology Data Exchange (ETDEWEB)

    Weber, Simone [Central Institute for Electronics, Forschungszentrum Juelich, 52425 Juelich (Germany)]. E-mail: s.weber@fz-juelich.de; Morel, Christian [Universite de la Mediterranee, Centre de Physique des Particules de Marseille (France); Simon, Luc [Institut Curie, Paris (France); Krieguer, Magalie [Vrije Universiteit Brussels (Belgium); Rey, Martin [Universite de Lausanne (Switzerland); Gundlich, Brigitte [Central Institute for Electronics, Forschungszentrum Juelich, 52425 Juelich (Germany); Khodaverdi, Maryam [Central Institute for Electronics, Forschungszentrum Juelich, 52425 Juelich (Germany)

    2006-12-20

    ClearPET{sup TM} is a family of small-animal PET scanners which are currently under development within the Crystal Clear Collaboration (CERN). All scanners are based on the same detector block design using individual LSO and LuYAP crystals in phoswich configuration, coupled to multi-anode photomultiplier tubes. One of the scanners, the ClearPET{sup TM} Neuro is designed for applications in neuroscience. Four detector blocks with 64 2x2x10 mm LSO and LuYAP crystals, arranged in line, build a module. Twenty modules are arranged in a ring with a ring diameter of 13.8 cm and an axial size of 11.2 cm. An insensitive region at the border of the detector heads results in gaps between the detectors axially and tangentially. The detectors are rotating by 360{sup o} in step and shoot mode during data acquisition. Every second module is shifted axially to compensate partly for the gaps between the detector blocks in a module. This unconventional scanner geometry requires dedicated image reconstruction procedures. Data acquisition acquires single events that are stored with a time mark in a dedicated list mode format. Coincidences are associated off line by software. After sorting the data into 3D sinograms, image reconstruction is performed using the Ordered Subset Maximum A Posteriori One-Step Late (OSMAPOSL) iterative algorithm implemented in the Software for Tomographic Image Reconstruction (STIR) library. Due to the non-conventional scanner design, careful estimation of the sensitivity matrix is needed to obtain artifact-free images from the ClearPET{sup TM} Neuro.

  17. I-124 labeled recombinant human annexin V produced by E. coli for apoptosis image using small animal PET

    Energy Technology Data Exchange (ETDEWEB)

    Jung, J. H.; Lee, I. S.; Woo, S. K.; Woo, G. S.; Chung, W. S.; Kang, J. H.; Cheon, G. J.; Choi, C. W.; Urn, S. M. [Korea Institute of Radiological and Medical Sciences, Daejeon (Korea, Republic of)

    2007-07-01

    Annexin V labeled with radioisotope and optical probe has been used to detect apoptosis. To evaluate annexin V as a multimodal apoptosis imaging agent, large-scale preparation of Annexin V (AV) is preliminary. The aim of this study is to produce and purify recombinant human Annexin V (rh-AV) in E. coli system and radiolabeled rh-AV evaluate in vitro and in vivo apoptosis model system. Annexin V cDNA was obtained from human placenta and rh-AV cloning vector used fusion E. coli vector. Expression vector was based on the E. coli pET system. Induction of rh-AV was used Isopropyl--D-thiogalactoside (IPTG) and purification was used TALON metal affinity resin and T7 - Taq. Purification yield confirmed through SDS-PAGE. In camptothecin (0, 50, 100 uM) induced Jurkat T cell apoptosis model, AV-PI flow cytometry analysis and in vitro binding assay of I-124 labeled rh - AV were performed and compared. Small animal PET images of I-124 labeled rh-AV were obtained in Fas-mediated hepatic apoptosis model. Optimum expression condition was at 37, 250 rpm, 8 hr in 2X YT media including 1mM IPTG, Through two step purification process, rh-AV confirmed about 35 Kd single band by SDS-PAGE. As camptothecin concentration increasing, annexin V-FITC positive % increased in flow cytometry analysis and uptake of I-124 labeled rh-AV also increased. Annexin V-FITC positive % was correlated with and uptake of I-124 labeled rh-AV (R{sup 2}=0.99). In Fas-mediated hepatic apoptosis model, I-124 labeled rh-AV was selectively localized in liver region in PET image. Recombinant Human annexin V was produced by E. coli system and purified using two step affinity chromatography. Radiolabeled rh-AV was useful for the evaluation of apoptosis in vitro and in vivo model. Recombinant human annexin V could be used as apoptosis imaging agent with various radiolabel and optical probe.

  18. Development and evaluation of a practical method to measure the Depth of Interaction function for a single side readout PET detector

    CERN Document Server

    Stringhini, G.; Ghezzi, A.; Stojkovic, A.; Paganoni, M.; Auffray, E.

    2016-01-01

    In small animal and organ dedicated PET scanners, the knowledge of depth of interaction (DOI) of the gamma ray along the main axis of the scintillator is a fundamental information in order to avoid parallax error and to achieve high performances in terms of spatial resolution. Recently we developed a new method to obtain the DOI function for a single side readout PET module, recirculating the scintillation light in the matrix by means of a mirror placed on top of the module. In a complete PET scanner, periodical DOI calibrations have to be performed to prevent time dependent miscalibrations and performance degradations. The current DOI calibration relies on a coincidence system between the module and an external scintillator to provide a priori the DOI information and it is clearly not feasible in a real system without unpractical disassemblies of the scanner. In this paper we develop instead a fast and precise calibration method based on uniform irradiation of the scintillators. Three irradiation modalities ...

  19. Use of visual and permanent identification for pets by veterinary clinics.

    Science.gov (United States)

    Dingman, P A; Levy, J K; Rockey, L E; Crandall, M M

    2014-07-01

    It is estimated that more than 5 million stray dogs and cats enter animal shelters in the USA each year, but less than half are ever reunited with their owners. Lost pets with identification microchips are up to 21 times more likely to be reunited than those without. Finders of lost pets are more likely to consult veterinarians than shelters for assistance, and pet owners look first to veterinarians for advice regarding pet health, protection, and welfare. An online survey of 1086 veterinary clinics in the South-Eastern USA was conducted to evaluate how veterinary clinics functioned as a part of the pet identification network. Scanning and microchip implants were offered by 91% of surveyed clinics and 41% used 'global' scanners capable of detecting all currently used microchip brands. Clinics more frequently relied on pet owners to register contact information rather than providing this service for clients (52% vs. 43%, respectively). Even though lost dogs are more likely to be reunited with owners than lost cats, microchips and collars were more likely to be recommended for all dogs (85% and 93%, respectively) than for all cats (67% and 61%, respectively). Only half of clinics that recommended identification collars made them available to their clients. Veterinarians can protect animals, pet owners and the human-animal bond by integrating pet identification into preventive health care. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Animal Companions: Fostering Children's Effort-Making by Nurturing Virtual Pets

    Science.gov (United States)

    Chen, Zhi-Hong; Liao, Calvin; Chien, Tzu-Chao; Chan, Tak-Wai

    2011-01-01

    Virtual character is a significant application in the research field of technology-enhanced learning. In this study, the concept of animal companions, "non-smart" virtual characters, is proposed as a way to encourage students to promote effort-making learning behaviours. The two underpinning design rationales are first discussed followed by the…

  1. Counseling with Pocket Pets: Using Small Animals in Elementary Counseling Programs

    Science.gov (United States)

    Flom, Barbara L.

    2005-01-01

    The power of the human-animal bond has been described in sources as diverse as ancient literature, modern fiction, and research reports in the professional literature (Chandler, 2001; Mallon, 1992; Parshall, 2003; Siegel, 1993). Educators have used classic examples, such as those found in the children's books Old Yeller and Where the Red Fern…

  2. The influence of the image reconstruction in relative quantification in SPECT/PET/CT animal; A influencia da reconstrucao da imagem na quantificacao relativa em SPECT/PET/CT animal

    Energy Technology Data Exchange (ETDEWEB)

    Soriano, Sarah; Sa, Lidia Vasconcellos de, E-mail: sarahsoriano@bolsista.ird.gov.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ),Rio de Janeiro, RJ (Brazil); Souza, Sergio; Barboza, Thiago [Hospital Universitario Clementino Fraga Filho (HUCFF/UFRJ), Rio de Janeiro, RJ (Brazil)

    2014-07-01

    The objective of this study is to evaluate the spatial resolution of the equipment SPECT/PET/CT animal to different reconstruction methods and the influence of this parameter in the mouse dosimetry C57BL6, aimed at development of new radiopharmaceuticals for use in humans. CT and SPECT images were obtained from a simulator composed of four spheres of different diameters (d), which simulate captating lesions by the equipment FLEX ™ Triumph ™ Pre-Clinical Imaging System used for preclinical studies in the Hospital Universitario (HU/UFRJ). In order to simulate a real study, the total volume of the simulator (body) was filled with a solution of {sup 99m}Tc diluted in water and the spheres were filled with concentrations four time higher than the body of the simulator. From the gross SPECT images it was used filtered backprojection method (FBP) with application of different filters: Hamming, Hann and Ramp, ranging the cutoff frequencies. The resolution of the equipment found in the study was 9.3 to 9.4 mm, very below the value provided by the manufacturer of 1.6mm. Thus, the protocol for mice can be optimized as being the FBP reconstruction method of Hamming filter, cutoff of 0.5 to yield a resolution from 9.3 to 9.4mm. This value indicates that captating regions of diameter below 9.3 mm are not properly quantified.

  3. THE CHARACTERISTICS OF EEC PET INSTRUMENTATION

    NARCIS (Netherlands)

    PAANS, AMJ

    1991-01-01

    As a result of a Guide-Questionnaire distributed among all European PET centers an inventory of the European PET instrumentation has become available in a data base. An overview and analysis of the European PET equipment, cyclotrons, scanners and software, together with some global information on

  4. Malassezia spp. dan Peranannya sebagai Penyebab Dermatitis pada Hewan Peliharaan (MALASSEZIA SPP AND ITS ROLE AS THE CAUSAL AGENT OF DERMATITIS IN PET ANIMALS

    Directory of Open Access Journals (Sweden)

    Pradipta Nuri Adiyati

    2015-05-01

    Full Text Available Malassezia is dimorphic yeast found normally in the animal healthy skin. Malassezia can causehealth problem in pet animals, such as dogs, cats, and other domestic animals. Varies according itsvirulence, Malassezia can cause skin changes characterized by severe pruritus, yellowish erythema andscab, greasy skin, bad odor with hyperpigmentation and lichenification in the face, paws, and neck bottom,as well as belly. Laboratory diagnosis can be performed either by microscopic examination of nativepreparations, or molecular biology. Treatment of Malassezia’s infection can still be made using someantifungals currently available. Malassezia pachydermatitis infection has been known as zoonoticpotential.

  5. Determination of dietary starch in animal feeds and pet food by an enzymatic-colorimetric method: collaborative study.

    Science.gov (United States)

    Hall, Mary Beth

    2015-01-01

    Starch, glycogen, maltooligosaccharides, and other α-1,4- and α-1,6-linked glucose carbohydrates, exclusive of resistant starch, are collectively termed "dietary starch". This nutritionally important fraction is increasingly measured for use in diet formulation for animals as it can have positive or negative effects on animal performance and health by affecting energy supply, glycemic index, and formation of fermentation products by gut microbes. AOAC Method 920.40 that was used for measuring dietary starch in animal feeds was invalidated due to discontinued production of a required enzyme. As a replacement, an enzymatic-colorimetric starch assay developed in 1997 that had advantages in ease of sample handling and accuracy compared to other methods was considered. The assay was further modified to improve utilization of laboratory resources and reduce time required for the assay. The assay is quasi-empirical: glucose is the analyte detected, but its release is determined by run conditions and specification of enzymes. The modified assay was tested in an AOAC collaborative study to evaluate its accuracy and reliability for determination of dietary starch in animal feedstuffs and pet foods. In the assay, samples are incubated in screw cap tubes with thermostable α-amylase in pH 5.0 sodium acetate buffer for 1 h at 100°C with periodic mixing to gelatinize and partially hydrolyze α-glucan. Amyloglucosidase is added, and the reaction mixture is incubated at 50°C for 2 h and mixed once. After subsequent addition of water, mixing, clarification, and dilution as needed, free + enzymatically released glucose are measured. Values from a separate determination of free glucose are subtracted to give values for enzymatically released glucose. Dietary starch equals enzymatically released glucose multiplied by 162/180 (or 0.9) divided by the weight of the as received sample. Fifteen laboratories that represented feed company, regulatory, research, and commercial feed

  6. An Economic Analysis of the UK Pet Dog Market and Animal Welfare: The case of the UK pet dog overpopulation problem

    OpenAIRE

    Siettou, Christina

    2015-01-01

    Pets are an important part of our society as they have become ‘part of the family’. However, one of the most important problems regarding the pet dog population is the great number of strays and their management. The annual stray survey conducted on behalf of Dogs Trust, one of the leading dog welfare organizations in the UK, has revealed that each year there are more than 100,000 stray dogs in the UK. To date, their management remains a problem only addressed by Local Authorities. \\ud \\ud Th...

  7. Assessment of MR-compatibility of SiPM PET insert using short optical fiber bundles for small animal research

    Science.gov (United States)

    Kang, H. G.; Hong, S. J.; Ko, G. B.; Yoon, H. S.; Song, I. C.; Rhee, J. T.; Lee, J. S.

    2015-12-01

    Simultaneous positron emission tomography (PET) and magnetic resonance imaging (MRI) can provide new perspectives in human disease research because of their complementary in-vivo imaging techniques. Previously, we have developed an MR-compatible PET insert based on optical fibers using silicon photomultipliers (SiPM). However when echo planar imaging (EPI) sequence was performed, signal intensity was slowly decreased by -0.9% over the 5.5 minutes and significant geometrical distortion was observed as the PET insert was installed inside an MRI bore, indicating that the PET electronics and its shielding boxes might have been too close to an MR imaging object. In this paper, optical fiber bundles with a length of 54 mm instead of 31 mm were employed to minimize PET interference on MR images. Furthermore, the LYSO crystals with a size of 1.5 × 1.5 × 7.0 mm3 were used instead of 2.47 × 2.74 × 20.0 mm3 for preclinical PET/MR applications. To improve the MR image quality, two receive-only loop coils were used. The effects of the PET insert on the SNR of the MR image either for morphological or advanced MR pulse sequences such as diffusion weighted imaging (DWI), functional MRI (fMRI), and magnetic resonance spectroscopy (MRS) were investigated. The quantitative MR compatibility such as B0 and B1 field homogeneity without PET, with `PET OFF', and with `PET ON' was also evaluated. In conclusion, B0 maps were not affected by the proposed PET insert whereas B1 maps were significantly affected by the PET insert. The advanced MRI sequences such as DWI, EPI, and MRS can be performed without a significant MR image quality degradation.

  8. Assessment of MR-compatibility of SiPM PET insert using short optical fiber bundles for small animal research

    International Nuclear Information System (INIS)

    Kang, H.G.; Hong, S.J.; Ko, G.B.; Yoon, H.S.; Lee, J.S.; Song, I.C.; Rhee, J.T.

    2015-01-01

    Simultaneous positron emission tomography (PET) and magnetic resonance imaging (MRI) can provide new perspectives in human disease research because of their complementary in-vivo imaging techniques. Previously, we have developed an MR-compatible PET insert based on optical fibers using silicon photomultipliers (SiPM). However when echo planar imaging (EPI) sequence was performed, signal intensity was slowly decreased by −0.9% over the 5.5 minutes and significant geometrical distortion was observed as the PET insert was installed inside an MRI bore, indicating that the PET electronics and its shielding boxes might have been too close to an MR imaging object. In this paper, optical fiber bundles with a length of 54 mm instead of 31 mm were employed to minimize PET interference on MR images. Furthermore, the LYSO crystals with a size of 1.5 × 1.5 × 7.0 mm 3 were used instead of 2.47 × 2.74 × 20.0 mm 3 for preclinical PET/MR applications. To improve the MR image quality, two receive-only loop coils were used. The effects of the PET insert on the SNR of the MR image either for morphological or advanced MR pulse sequences such as diffusion weighted imaging (DWI), functional MRI (fMRI), and magnetic resonance spectroscopy (MRS) were investigated. The quantitative MR compatibility such as B 0 and B 1 field homogeneity without PET, with 'PET OFF', and with 'PET ON' was also evaluated. In conclusion, B 0 maps were not affected by the proposed PET insert whereas B 1 maps were significantly affected by the PET insert. The advanced MRI sequences such as DWI, EPI, and MRS can be performed without a significant MR image quality degradation

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

    International Nuclear Information System (INIS)

    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

  10. Another breed of "service" animals: STARS study findings about pet ownership and recovery from serious mental illness.

    Science.gov (United States)

    Wisdom, Jennifer P; Saedi, Goal Auzeen; Green, Carla A

    2009-07-01

    This study elucidates the role of pets in recovery processes among adults with serious mental illness. Data derive from interviews with 177 HMO members with serious mental illness (52.2% women, average age 48.8 years) in the Study of Transitions and Recovery Strategies (STARS). Interviews and questionnaires addressed factors affecting recovery processes and included questions about pet ownership. Data were analyzed using a modified grounded theory method to identify the roles pets play in the recovery process. Primary themes indicate pets assist individuals in recovery from serious mental illness by (a) providing empathy and "therapy"; (b) providing connections that can assist in redeveloping social avenues; (c) serving as "family" in the absence of or in addition to human family members; and (d) supporting self-efficacy and strengthening a sense of empowerment. Pets appear to provide more benefits than merely companionship. Participants' reports of pet-related contributions to their well-being provide impetus to conduct more formal research on the mechanisms by which pets contribute to recovery and to develop pet-based interventions.

  11. Motivated mind perception: treating pets as people and people as animals.

    Science.gov (United States)

    Epley, Nicholas; Schroeder, Juliana; Waytz, Adam

    2013-01-01

    Human beings have a sophisticated ability to reason about the minds of others, often referred to as using one's theory of mind or mentalizing. Just like any other cognitive ability, people engage in reasoning about other minds when it seems useful for achieving particular goals, but this ability remains disengaged otherwise. We suggest that understanding the factors that engage our ability to reason about the minds of others helps to explain anthropomorphism: cases in which people attribute minds to a wide range of nonhuman agents, including animals, mechanical and technological objects, and supernatural entities such as God. We suggest that engagement is guided by two basic motivations: (1) the motivation to explain and predict others' actions, and (2) the motivation to connect socially with others. When present, these motivational forces can lead people to attribute minds to almost any agent. When absent, the likelihood of attributing a mind to others, even other human beings, decreases. We suggest that understanding the factors that engage our theory of mind can help to explain the inverse process of dehumanization, and also why people might be indifferent to other people even when connecting to them would improve their momentary wellbeing.

  12. 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.

  13. New scintillating crystals for PET scanners

    CERN Document Server

    Lecoq, P

    2002-01-01

    Systematic R&D on basic mechanism in inorganic scintillators, initiated by the Crystal Clear Collaboration at CERN 10 years ago, has contributed not to a small amount, to the development of new materials for a new generation of medical imaging devices with increased resolution and sensitivity. The first important requirement for a scintillator to be used in medical imaging devices is the stopping power for the given energy range of X and gamma rays to be considered, and more precisely the conversion efficiency. A high light yield is also mandatory to improve the energy resolution, which is essentially limited by the photostatistics and the electronic noise at these energies. A short scintillation decay time allows to reduce the dead time and therefore to increase the limiting counting rate. When all these requirements are fulfilled the sensitivity and image contrast are increased for a given patient dose, or the dose can be reduced. Examples of new materials under development by the Crystal Clear Collabor...

  14. Statistical parametric maps of 18F-FDG PET and 3-D autoradiography in the rat brain: a cross-validation study

    International Nuclear Information System (INIS)

    Prieto, Elena; Marti-Climent, Josep M.; Collantes, Maria; Molinet, Francisco; Delgado, Mercedes; Garcia-Garcia, Luis; Pozo, Miguel A.; Juri, Carlos; Fernandez-Valle, Maria E.; Gago, Belen; Obeso, Jose A.; Penuelas, Ivan

    2011-01-01

    Although specific positron emission tomography (PET) scanners have been developed for small animals, spatial resolution remains one of the most critical technical limitations, particularly in the evaluation of the rodent brain. The purpose of the present study was to examine the reliability of voxel-based statistical analysis (Statistical Parametric Mapping, SPM) applied to 18 F-fluorodeoxyglucose (FDG) PET images of the rat brain, acquired on a small animal PET not specifically designed for rodents. The gold standard for the validation of the PET results was the autoradiography of the same animals acquired under the same physiological conditions, reconstructed as a 3-D volume and analysed using SPM. Eleven rats were studied under two different conditions: conscious or under inhalatory anaesthesia during 18 F-FDG uptake. All animals were studied in vivo under both conditions in a dedicated small animal Philips MOSAIC PET scanner and magnetic resonance images were obtained for subsequent spatial processing. Then, rats were randomly assigned to a conscious or anaesthetized group for postmortem autoradiography, and slices from each animal were aligned and stacked to create a 3-D autoradiographic volume. Finally, differences in 18 F-FDG uptake between conscious and anaesthetized states were assessed from PET and autoradiography data by SPM analysis and results were compared. SPM results of PET and 3-D autoradiography are in good agreement and led to the detection of consistent cortical differences between the conscious and anaesthetized groups, particularly in the bilateral somatosensory cortices. However, SPM analysis of 3-D autoradiography also highlighted differences in the thalamus that were not detected with PET. This study demonstrates that any difference detected with SPM analysis of MOSAIC PET images of rat brain is detected also by the gold standard autoradiographic technique, confirming that this methodology provides reliable results, although partial volume

  15. Statistical parametric maps of {sup 18}F-FDG PET and 3-D autoradiography in the rat brain: a cross-validation study

    Energy Technology Data Exchange (ETDEWEB)

    Prieto, Elena; Marti-Climent, Josep M. [Clinica Universidad de Navarra, Nuclear Medicine Department, Pamplona (Spain); Collantes, Maria; Molinet, Francisco [Center for Applied Medical Research (CIMA) and Clinica Universidad de Navarra, Small Animal Imaging Research Unit, Pamplona (Spain); Delgado, Mercedes; Garcia-Garcia, Luis; Pozo, Miguel A. [Universidad Complutense de Madrid, Brain Mapping Unit, Madrid (Spain); Juri, Carlos [Center for Applied Medical Research (CIMA), Movement Disorders Group, Neurosciences Division, Pamplona (Spain); Clinica Universidad de Navarra, Department of Neurology and Neurosurgery, Pamplona (Spain); Centro de Investigacion Biomedica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Pamplona (Spain); Pontificia Universidad Catolica de Chile, Department of Neurology, Santiago (Chile); Fernandez-Valle, Maria E. [Universidad Complutense de Madrid, MRI Research Center, Madrid (Spain); Gago, Belen [Center for Applied Medical Research (CIMA), Movement Disorders Group, Neurosciences Division, Pamplona (Spain); Centro de Investigacion Biomedica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Pamplona (Spain); Obeso, Jose A. [Center for Applied Medical Research (CIMA), Movement Disorders Group, Neurosciences Division, Pamplona (Spain); Clinica Universidad de Navarra, Department of Neurology and Neurosurgery, Pamplona (Spain); Centro de Investigacion Biomedica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Pamplona (Spain); Penuelas, Ivan [Clinica Universidad de Navarra, Nuclear Medicine Department, Pamplona (Spain); Center for Applied Medical Research (CIMA) and Clinica Universidad de Navarra, Small Animal Imaging Research Unit, Pamplona (Spain)

    2011-12-15

    Although specific positron emission tomography (PET) scanners have been developed for small animals, spatial resolution remains one of the most critical technical limitations, particularly in the evaluation of the rodent brain. The purpose of the present study was to examine the reliability of voxel-based statistical analysis (Statistical Parametric Mapping, SPM) applied to {sup 18}F-fluorodeoxyglucose (FDG) PET images of the rat brain, acquired on a small animal PET not specifically designed for rodents. The gold standard for the validation of the PET results was the autoradiography of the same animals acquired under the same physiological conditions, reconstructed as a 3-D volume and analysed using SPM. Eleven rats were studied under two different conditions: conscious or under inhalatory anaesthesia during {sup 18}F-FDG uptake. All animals were studied in vivo under both conditions in a dedicated small animal Philips MOSAIC PET scanner and magnetic resonance images were obtained for subsequent spatial processing. Then, rats were randomly assigned to a conscious or anaesthetized group for postmortem autoradiography, and slices from each animal were aligned and stacked to create a 3-D autoradiographic volume. Finally, differences in {sup 18}F-FDG uptake between conscious and anaesthetized states were assessed from PET and autoradiography data by SPM analysis and results were compared. SPM results of PET and 3-D autoradiography are in good agreement and led to the detection of consistent cortical differences between the conscious and anaesthetized groups, particularly in the bilateral somatosensory cortices. However, SPM analysis of 3-D autoradiography also highlighted differences in the thalamus that were not detected with PET. This study demonstrates that any difference detected with SPM analysis of MOSAIC PET images of rat brain is detected also by the gold standard autoradiographic technique, confirming that this methodology provides reliable results, although

  16. 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.

  17. Test beam measurement of the first prototype of the fast silicon pixel monolithic detector for the TT-PET project

    Science.gov (United States)

    Paolozzi, L.; Bandi, Y.; Benoit, M.; Cardarelli, R.; Débieux, S.; Forshaw, D.; Hayakawa, D.; Iacobucci, G.; Kaynak, M.; Miucci, A.; Nessi, M.; Ratib, O.; Ripiccini, E.; Rücker, H.; Valerio, P.; Weber, M.

    2018-04-01

    The TT-PET collaboration is developing a PET scanner for small animals with 30 ps time-of-flight resolution and sub-millimetre 3D detection granularity. The sensitive element of the scanner is a monolithic silicon pixel detector based on state-of-the-art SiGe BiCMOS technology. The first ASIC prototype for the TT-PET was produced and tested in the laboratory and with minimum ionizing particles. The electronics exhibit an equivalent noise charge below 600 e‑ RMS and a pulse rise time of less than 2 ns , in accordance with the simulations. The pixels with a capacitance of 0.8 pF were measured to have a detection efficiency greater than 99% and, although in the absence of the post-processing, a time resolution of approximately 200 ps .

  18. Design and performance evaluation of a coplanar multimodality scanner for rodent imaging

    Energy Technology Data Exchange (ETDEWEB)

    Lage, E; Vaquero, J J; Sisniega, A; Tapias, G; Abella, M; Rodriguez-Ruano, A; Desco, M [Unidad de Medicina y Cirugia Experimental, Hospital General Universitario Gregorio Maranon, Madrid (Spain); Espana, S [Departamento de Fisica Atomica, Molecular y Nuclear, Facultad de Ciencias Fisicas, Universidad Complutense, Madrid (Spain); Ortuno, J E [Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Zaragoza (Spain); Udias, A [Departamento de Estadistica e Investigacion Operativa, Universidad Rey Juan Carlos, Fuenlabrada (Spain)], E-mail: elage@mce.hggm.es

    2009-09-21

    This work reports on the development and performance evaluation of the VrPET/CT, a new multimodality scanner with coplanar geometry for in vivo rodent imaging. The scanner design is based on a partial-ring PET system and a small-animal CT assembled on a rotatory gantry without axial displacement between the geometric centers of both fields of view (FOV). We report on the PET system performance based on the NEMA NU-4 protocol; the performance characteristics of the CT component are not included herein. The accuracy of inter-modality alignment and the imaging capability of the whole system are also evaluated on phantom and animal studies. Tangential spatial resolution of PET images ranged between 1.56 mm at the center of the FOV and 2.46 at a radial offset of 3.5 cm. The radial resolution varies from 1.48 mm to 1.88 mm, and the axial resolution from 2.34 mm to 3.38 mm for the same positions. The energy resolution was 16.5% on average for the entire system. The absolute coincidence sensitivity is 2.2% for a 100-700 keV energy window with a 3.8 ns coincident window. The scatter fraction values for the same settings were 11.45% for a mouse-sized phantom and 23.26% for a rat-sized phantom. The peak noise equivalent count rates were also evaluated for those phantoms obtaining 70.8 kcps at 0.66 MBq/cc and 31.5 kcps at 0.11 MBq/cc, respectively. The accuracy of inter-modality alignment is below half the PET resolution, and the image quality of biological specimens agrees with measured performance parameters. The assessment presented in this study shows that the VrPET/CT system is a good performance small-animal imager, while the cost derived from a partial ring detection system is substantially reduced as compared with a full-ring PET tomograph.

  19. Pets and Parasites

    Science.gov (United States)

    ... animals. This is how cats get the toxoplasmosis parasite. Keep your pets away from wild animals or stray pets (which may be unvaccinated or sick). Things to consider Reptiles (such as lizards, snakes, and turtles) carry bacteria (germs) that can make ...

  20. From Pests to Pets: Social and Cultural Perceptions of Animals in Post-medieval Urban Centres in England (AD1500 – 1900

    Directory of Open Access Journals (Sweden)

    Rebecca Gordon

    2017-03-01

    Full Text Available In the past, animals and their products were prominent features of urban life. How people utilised these animals as well as their relationships has continually changed. For example, cats, dogs, pigs and other animals lived in close proximity to people in post-medieval urban centres and were viewed in terms of their functional affordances. Cats were kept to deter rodents and exploited for their fur, dogs were protectors of the home and pigs were not only food, but helped to reduce the amount of rubbish where they were kept. However, perceptions and treatment of urban animals were far from static. The emergent animal welfare movement and legislation heralded a change in the species and numbers of animals present in the urban environment and altered human-animal relationships. Now people are detached from ‘livestock’ (e.g. pigs, but have developed closer bonds with companion animals (e.g. cats, dogs, etc.. In this article I will draw upon zooarchaeological and historical evidence in an attempt to show the timing of this transition and highlight some key factors in the accompanying shift in human-animal relationships, while focusing more specifically on pet-keeping in a city context.

  1. Healthy Pets and People

    Science.gov (United States)

    ... people to get sick from diseases shared between animals and people (also known as zoonotic diseases or zoonoses). CDC ... valuable source of information on diseases shared between animals and people. Keep Your Pet Healthy Whether you have a ...

  2. FIRST: Fast Iterative Reconstruction Software for (PET) tomography

    Energy Technology Data Exchange (ETDEWEB)

    Herraiz, J L [Dpto. Fisica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid (Spain); Espana, S [Dpto. Fisica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid (Spain); Vaquero, J J [Unidad de Medicina y CirugIa Experimental, Hospital GU Gregorio Maranon, Madrid (Spain); Desco, M [Unidad de Medicina y CirugIa Experimental, Hospital GU Gregorio Maranon, Madrid (Spain); UdIas, J M [Dpto. Fisica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid (Spain)

    2006-09-21

    Small animal PET scanners require high spatial resolution and good sensitivity. To reconstruct high-resolution images in 3D-PET, iterative methods, such as OSEM, are superior to analytical reconstruction algorithms, although their high computational cost is still a serious drawback. The higher performance of modern computers could make iterative image reconstruction fast enough to be viable, provided we are able to deal with the large number of probability coefficients for the system response matrix in high-resolution PET scanners, which is a difficult task that prevents the algorithms from reaching peak computing performance. Considering all possible axial and in-plane symmetries, as well as certain quasi-symmetries, we have been able to reduce the memory requirements to store the system response matrix (SRM) well below 1 GB, which allows us to keep the whole response matrix of the system inside RAM of ordinary industry-standard computers, so that the reconstruction algorithm can achieve near peak performance. The elements of the SRM are stored as cubic spline profiles and matched to voxel size during reconstruction. In this way, the advantages of 'on-the-fly' calculation and of fully stored SRM are combined. The on-the-fly part of the calculation (matching the profile functions to voxel size) of the SRM accounts for 10-30% of the reconstruction time, depending on the number of voxels chosen. We tested our approach with real data from a commercial small animal PET scanner. The results (image quality and reconstruction time) show that the proposed technique is a feasible solution.

  3. FIRST: Fast Iterative Reconstruction Software for (PET) tomography

    International Nuclear Information System (INIS)

    Herraiz, J L; Espana, S; Vaquero, J J; Desco, M; UdIas, J M

    2006-01-01

    Small animal PET scanners require high spatial resolution and good sensitivity. To reconstruct high-resolution images in 3D-PET, iterative methods, such as OSEM, are superior to analytical reconstruction algorithms, although their high computational cost is still a serious drawback. The higher performance of modern computers could make iterative image reconstruction fast enough to be viable, provided we are able to deal with the large number of probability coefficients for the system response matrix in high-resolution PET scanners, which is a difficult task that prevents the algorithms from reaching peak computing performance. Considering all possible axial and in-plane symmetries, as well as certain quasi-symmetries, we have been able to reduce the memory requirements to store the system response matrix (SRM) well below 1 GB, which allows us to keep the whole response matrix of the system inside RAM of ordinary industry-standard computers, so that the reconstruction algorithm can achieve near peak performance. The elements of the SRM are stored as cubic spline profiles and matched to voxel size during reconstruction. In this way, the advantages of 'on-the-fly' calculation and of fully stored SRM are combined. The on-the-fly part of the calculation (matching the profile functions to voxel size) of the SRM accounts for 10-30% of the reconstruction time, depending on the number of voxels chosen. We tested our approach with real data from a commercial small animal PET scanner. The results (image quality and reconstruction time) show that the proposed technique is a feasible solution

  4. Evaluation of a silicon photomultiplier PET insert for simultaneous PET and MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Ko, Guen Bae; Kim, Kyeong Yun; Yoon, Hyun Suk; Son, Jeong-Whan [Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul 110-799, South Korea and Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul 110-799 (Korea, Republic of); Lee, Min Sun [Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul 110-799, South Korea and Interdisciplinary Program in Radiation Applied Life Science, Seoul National University College of Medicine, Seoul 110-799 (Korea, Republic of); Im, Hyung-Jun [Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul 110-799 (Korea, Republic of); Lee, Jae Sung, E-mail: jaes@snu.ac.kr [Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul 110-799 (Korea, Republic of); Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul 110-799 (Korea, Republic of); Interdisciplinary Program in Radiation Applied Life Science, Seoul National University College of Medicine, Seoul 110-799 (Korea, Republic of); Institute of Radiation Medicine, Medical Research Center, Seoul National University College of Medicine, Seoul 110-799 (Korea, Republic of)

    2016-01-15

    Purpose: In this study, the authors present a silicon photomultiplier (SiPM)-based positron emission tomography (PET) insert dedicated to small animal imaging with high system performance and robustness to temperature change. Methods: The insert consists of 64 LYSO-SiPM detector blocks arranged in 4 rings of 16 detector blocks to yield a ring diameter of 64 mm and axial field of view of 55 mm. Each detector block consists of a 9 × 9 array of LYSO crystals (1.2 × 1.2 × 10 mm{sup 3}) and a monolithic 4 × 4 SiPM array. The temperature of each monolithic SiPM is monitored, and the proper bias voltage is applied according to the temperature reading in real time to maintain uniform performance. The performance of this PET insert was characterized using National Electrical Manufacturers Association NU 4-2008 standards, and its feasibility was evaluated through in vivo mouse imaging studies. Results: The PET insert had a peak sensitivity of 3.4% and volumetric spatial resolutions of 1.92 (filtered back projection) and 0.53 (ordered subset expectation maximization) mm{sup 3} at center. The peak noise equivalent count rate and scatter fraction were 42.4 kcps at 15.08 MBq and 16.5%, respectively. By applying the real-time bias voltage adjustment, an energy resolution of 14.2% ± 0.3% was maintained and the count rate varied ≤1.2%, despite severe temperature changes (10–30 °C). The mouse imaging studies demonstrate that this PET insert can produce high-quality images useful for imaging studies on the small animals. Conclusions: The developed MR-compatible PET insert is designed for insertion into a narrow-bore magnetic resonance imaging scanner, and it provides excellent imaging performance for PET/MR preclinical studies.

  5. Cardiac PET Imaging of Blood Flow, Metabolism, and Function in Normal and Infarcted Rats

    Science.gov (United States)

    Lecomte, R.; Croteau, E.; Gauthier, M.-E.; Archambault, M.; Aliaga, A.; Rousseau, J.; Cadorette, J.; Leroux, J.-D.; Lepage, M. D.; Benard, F.; Bentourkia, M.

    2004-06-01

    The rat heart is an excellent model for the investigation of cardiac physiology and metabolism. It has been used extensively for ex vivo studies of the normal heart as well as for the study of various heart diseases. With the advent of dedicated high-resolution small animal PET scanners, it is now possible to transpose many of the cardiac studies routinely used in humans to the rat. These include the in vivo measurement of myocardial blood flow, metabolism, and function. Because these techniques are noninvasive, the same animal can be imaged repetitively, thus allowing for follow-up studies of disease progression and for the assessment of new therapeutic methods. In this work, we report on cardiac studies performed in normal and diseased rats using the Sherbrooke avalanche photodiode PET scanner, a small animal PET imaging device achieving 14 /spl mu/l volumetric spatial resolution with excellent image signal-to-noise ratio. The system also features flexible list-mode data acquisition, which allows dynamic studies to be resampled as desired for kinetic modeling. These cardiac PET imaging methods were used for the follow-up of infarcted rats submitted to experimental intramyocardial revascularization therapy.

  6. Animal Bites

    Science.gov (United States)

    Wild animals usually avoid people. They might attack, however, if they feel threatened, are sick, or are protecting their ... or territory. Attacks by pets are more common. Animal bites rarely are life-threatening, but if they ...

  7. MRI compatibility of position-sensitive photomultiplier depth-of-interaction PET detectors modules for in-line multimodality preclinical studies

    Energy Technology Data Exchange (ETDEWEB)

    Vaquero, J.J., E-mail: juanjose.vaquero@uc3m.es [Universidad Carlos III de Madrid, Departamento de Bioingeniería e Ingeniería Aeroespacial, Avda. de la Universidad 30 Leganés, 28911 Madrid (Spain); Instituto de Investigación Sanitaria Gregorio Marañón, Madrid (Spain); Sánchez, J.J. [Instituto de Investigación Sanitaria Gregorio Marañón, Madrid (Spain); Udías, J.M.; Cal-González, J. [Grupo de Física Nuclear, Departamento de Física Atómica, Molecular y Nuclear, Universidad Complutense de Madrid, CEI Moncloa, Madrid (Spain); Desco, M. [Universidad Carlos III de Madrid, Departamento de Bioingeniería e Ingeniería Aeroespacial, Avda. de la Universidad 30 Leganés, 28911 Madrid (Spain); Instituto de Investigación Sanitaria Gregorio Marañón, Madrid (Spain)

    2013-02-21

    This work addresses the feasibility of a small-animal, in-line PET/MR system based on Position-Sensitive Photo Multiplier Tubes (PS-PMTs). To this end, we measured the effects of static magnetic fields on the PS-PMTs performance in order to explore the minimal tandem separation between the PET and MR subsystems to preserve their respective performances. We concluded that it is possible to achieve minimal degradation of the PET scanner performance (after a system recalibration) if the magnetic field strength influencing the PET detectors is less than 1 mT and if it is oriented perpendicularly to the longitudinal axis of the tube. Therefore, we predict that it will be possible to maintain the PET image quality if it is placed outside the 1 mT line.

  8. Simultaneous ECG-gated PET imaging of multiple mice

    International Nuclear Information System (INIS)

    Seidel, Jurgen; Bernardo, Marcelino L.; Wong, Karen J.; Xu, Biying; Williams, Mark R.; Kuo, Frank; Jagoda, Elaine M.; Basuli, Falguni; Li, Changhui; Griffiths, Gary L.

    2014-01-01

    Introduction: We describe and illustrate a method for creating ECG-gated PET images of the heart for each of several mice imaged at the same time. The method is intended to increase “throughput” in PET research studies of cardiac dynamics or to obtain information derived from such studies, e.g. tracer concentration in end-diastolic left ventricular blood. Methods: An imaging bed with provisions for warming, anesthetic delivery, etc., was fabricated by 3D printing to allow simultaneous PET imaging of two side-by-side mice. After electrode attachment, tracer injection and placement of the animals in the scanner field of view, ECG signals from each animal were continuously analyzed and independent trigger markers generated whenever an R-wave was detected in each signal. PET image data were acquired in “list” mode and these trigger markers were inserted into this list along with the image data. Since each mouse is in a different spatial location in the FOV, sorting of these data using trigger markers first from one animal and then the other yields two independent and correctly formed ECG-gated image sequences that reflect the dynamical properties of the heart during an “average” cardiac cycle. Results: The described method yields two independent ECG-gated image sequences that exhibit the expected properties in each animal, e.g. variation of the ventricular cavity volumes from maximum to minimum and back during the cardiac cycle in the processed animal with little or no variation in these volumes during the cardiac cycle in the unprocessed animal. Conclusion: ECG-gated image sequences for each of several animals can be created from a single list mode data collection using the described method. In principle, this method can be extended to more than two mice (or other animals) and to other forms of physiological gating, e.g. respiratory gating, when several subjects are imaged at the same time

  9. 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...... of different MRI techniques, such as DWI-MR (diffusion weighted imaging MR), DCE-MR (dynamic contrast enhanced MR), MRS (MR spectroscopy) and MR for attenuation correction of PET. All MR techniques presented in this paper have shown promising results in the treatment of patients with solid tumors and could...

  10. Pets and the immunocompromised person

    Science.gov (United States)

    ... can get infections, such as toxoplasmosis, by eating wild animals. DO NOT let your pet drink from the ... bird's cage. Other important tips: DO NOT adopt wild or exotic animals. These animals are more likely to bite. They ...

  11. Ready for prime time? Dual tracer PET and SPECT imaging.

    Science.gov (United States)

    Fakhri, Georges El

    2012-01-01

    Dual isotope single photon emission computed tomography (SPECT) and dual tracer positron emission tomography (PET) imaging have great potential in clinical and molecular applications in the pediatric as well as the adult populations in many areas of brain, cardiac, and oncologic imaging as it allows the exploration of different physiological and molecular functions (e.g., perfusion, neurotransmission, metabolism, apoptosis, angiogenesis) under the same physiological and physical conditions. This is crucial when the physiological functions studied depend on each other (e.g., perfusion and metabolism) hence requiring simultaneous assessment under identical conditions, and can reduce greatly the quantitation errors associated with physical factors that can change between acquisitions (e.g., human subject or animal motion, change in the attenuation map as a function of time) as is detailed in this editorial. The clinical potential of simultaneous dual isotope SPECT, dual tracer PET and dual SPECT/PET imaging are explored and summarized. In this issue of AJNMMI (http://www.ajnmmi.us), Chapman et al. explore the feasibility of simultaneous and sequential SPECT/PET imaging and conclude that down-scatter and crosstalk from 511 keV photons preclude obtaining useful SPECT information in the presence of PET radiotracers. They report on an alternative strategy that consists of performing sequential SPECT and PET studies in hybrid microPET/SPECT/CT scanners, now widely available for molecular imaging. They validate their approach in a phantom consisting of a 96-well plate with variable (99m)Tc and (18)F concentrations and illustrate the utility of such approaches in two sequential SPECT-PET/CT studies that include (99m)Tc-MAA/(18)F-NaF and (99m)Tc-Pentetate/(18)F-NaF. These approaches will need to be proven reproducible, accurate and robust to variations in the experimental conditions before they can be accepted by the molecular imaging community and be implemented in routine

  12. Limits of Tumor Detectability in Nuclear Medicine and PET

    Directory of Open Access Journals (Sweden)

    Yusuf Emre Erdi

    2012-04-01

    Full Text Available Objective: Nuclear medicine is becoming increasingly important in the early detection of malignancy. The advantage of nuclear medicine over other imaging modalities is the high sensitivity of the gamma camera. Nuclear medicine counting equipment has the capability of detecting levels of radioactivity which exceed background levels by as little as 2.4 to 1. This translates to only a few hundred counts per minute on a regular gamma camera or as few as 3 counts per minute when using coincidence detection on a positron emission tomography (PET camera. Material and Methods: We have experimentally measured the limits of detectability using a set of hollow spheres in a Jaszczak phantom at various tumor-to-background ratios. Imaging modalities for this work were (1 planar, (2 SPECT, (3 PET, and (4 planar camera with coincidence detection capability (MCD. Results: When there is no background (infinite contrast activity present, the detectability of tumors is similar for PET and planar imaging. With the presence of the background activity , PET can detect objects in an order of magnitude smaller in size than that can be seen by conventional planar imaging especially in the typical clinical low (3:1 T/B ratios. The detection capability of the MCD camera lies between a conventional nuclear medicine (planar / SPECT scans and the detection capability of a dedicated PET scanner Conclusion: Among nuclear medicine’s armamentarium, PET is the closest modality to CT or MR imaging in terms of limits of detection. Modern clinical PET scanners have a resolution limit of 4 mm, corresponding to the detection of tumors with a volume of 0.2 ml (7 mm diameter in 5:1 T/B ratio. It is also possible to obtain better resolution limits with dedicated brain and animal scanners. The future holds promise in development of new detector materials, improved camera design, and new reconstruction algorithms which will improve sensitivity, resolution, contrast, and thereby further

  13. 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

  14. P.I.X.S.C.A.N.: a micro-CT scanner for small animal based on hybrid pixel detectors

    International Nuclear Information System (INIS)

    Khoury, R.

    2008-03-01

    Since more than a dozen years, efforts were led in the field of X-ray tomography for small animals, principally for the improvement of spatial resolution and the diminution of the absorbed dose. The C.P.P.M. developed the micro-CT P.I.X.S.C.A.N. based on the hybrid pixel detector X.P.A.D.2. In this context, my thesis work consists in studying the demonstrator P.I.X.S.C.A.N./X.P.A.D.2 and the contribution of the hybrid pixels in the imaging of small animals. A fast analytical simulation, FastSimu, was developed. An extrapolation of the performance of the demonstrator P.I.X.S.C.A.N, as well as the validation of the results obtained with the measured data, were led by means of the analytical simulator FastSimu. The demonstrator P.I.X.S.C.A.N./X.P.A.D.2 allowed to obtain reconstructed images with a rather good quality for a relatively weak absorbed dose. Its spatial resolution is degraded by the high number of defective pixels of the detector X.P.A.D.2. Beyond this study, a new version of the demonstrator P.I.X.S.C.A.N./X.P.A.D.2 is under construction. This latter, characterized by two and a half times smaller pixels and about no defective pixels will bring a considerable improvement on spatial resolution. (author)

  15. Early life exposures to home dampness, pet ownership and farm animal contact and neuropsychological development in 4 year old children: a prospective birth cohort study.

    Science.gov (United States)

    Casas, Lidia; Torrent, Maties; Zock, Jan-Paul; Doekes, Gert; Forns, Joan; Guxens, Mònica; Täubel, Martin; Heinrich, Joachim; Sunyer, Jordi

    2013-11-01

    Exposure to biocontaminants is associated with behavioural problems and poorer cognitive function. Our study assesses the associations between early life exposure to home dampness, pets and farm animal contact and cognitive function and social competences in 4-year old children, and the associations between these indoor factors and microbial compounds (bacterial endotoxin and fungal extracellular polysaccharides). A Spanish population-based birth-cohort enrolled 482 children, and 424 of them underwent psychometric testing at 4 years of age, including the McCarthy Scales of Child Abilities (MSCA) and the California Preschool Social Competence Scale (CPSCS). Information on pet ownership, farm animal contact and home dampness was periodically reported by the parents through questionnaires. Microbial compounds were measured in living room sofa dust collected at the age of 3 months. Persistent home dampness during early life significantly decreased the general score of MSCA by 4.9 points (95% CI: -8.9; -0.8), and it decreased the CPSCS by 6.5 points (95% CI: -12.2; -0.9) in the child's bedroom. Cat or dog ownership were not associated with the outcomes, but occasional farm animal contact increased the general cognitive score of MSCA by 5.6 points (95% CI: 1.8; 9.3). Cat and dog ownership were associated with higher levels of endotoxins in home dust. None of the measured microbial compounds were related with the psychometric tests scores. In conclusion, damp housing in early life may have adverse effects on neuropsychological development at 4 years old. More research is needed to explore the possible involvement of mycotoxins in the observed results. Copyright © 2013 Elsevier GmbH. All rights reserved.

  16. The pivotal role of FDG-PET/CT in modern medicine

    DEFF Research Database (Denmark)

    Hess, Søren; Blomberg, Björn Alexander; Zhu, Hongyun June

    2014-01-01

    to the emergence of hybrid scanners combining PET with computed tomography (PET/CT). Molecular imaging has enormous potential for advancing biological research and patient care, and FDG-PET/CT is currently the most widely used technology in this domain. In this review, we discuss contemporary applications of FDG......-PET and FDG-PET/CT as well as novel developments in quantification and potential future indications including the emerging new modality PET/magnetic resonance imaging....

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

    International Nuclear Information System (INIS)

    Willemink, Martin J; Eldib, Mootaz; Leiner, Tim; Fayad, Zahi A; Mani, Venkatesh

    2015-01-01

    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.

  18. Noninvasive image derived heart input function for CMRglc measurements in small animal slow infusion FDG PET studies

    Science.gov (United States)

    Xiong, Guoming; Cumming, Paul; Todica, Andrei; Hacker, Marcus; Bartenstein, Peter; Böning, Guido

    2012-12-01

    Absolute quantitation of the cerebral metabolic rate for glucose (CMRglc) can be obtained in positron emission tomography (PET) studies when serial measurements of the arterial [18F]-fluoro-deoxyglucose (FDG) input are available. Since this is not always practical in PET studies of rodents, there has been considerable interest in defining an image-derived input function (IDIF) by placing a volume of interest (VOI) within the left ventricle of the heart. However, spill-in arising from trapping of FDG in the myocardium often leads to progressive contamination of the IDIF, which propagates to underestimation of the magnitude of CMRglc. We therefore developed a novel, non-invasive method for correcting the IDIF without scaling to a blood sample. To this end, we first obtained serial arterial samples and dynamic FDG-PET data of the head and heart in a group of eight anaesthetized rats. We fitted a bi-exponential function to the serial measurements of the IDIF, and then used the linear graphical Gjedde-Patlak method to describe the accumulation in myocardium. We next estimated the magnitude of myocardial spill-in reaching the left ventricle VOI by assuming a Gaussian point-spread function, and corrected the measured IDIF for this estimated spill-in. Finally, we calculated parametric maps of CMRglc using the corrected IDIF, and for the sake of comparison, relative to serial blood sampling from the femoral artery. The uncorrected IDIF resulted in 20% underestimation of the magnitude of CMRglc relative to the gold standard arterial input method. However, there was no bias with the corrected IDIF, which was robust to the variable extent of myocardial tracer uptake, such that there was a very high correlation between individual CMRglc measurements using the corrected IDIF with gold-standard arterial input results. Based on simulation, we furthermore find that electrocardiogram-gating, i.e. ECG-gating is not necessary for IDIF quantitation using our approach.

  19. Evaluation of brain SERT occupancy by resveratrol against MDMA-induced neurobiological and behavioral changes in rats: A 4-[¹⁸F]-ADAM/small-animal PET study.

    Science.gov (United States)

    Shih, Jui-Hu; Ma, Kuo-Hsing; Chen, Chien-Fu F; Cheng, Cheng-Yi; Pao, Li-Heng; Weng, Shao-Ju; Huang, Yuahn-Sieh; Shiue, Chyng-Yann; Yeh, Ming-Kung; Li, I-Hsun

    2016-01-01

    The misuse of 3,4-methylenedioxymethamphetamine (MDMA) has drawn a growing concern worldwide for its psychophysiological impacts on humans. MDMA abusers are often accompanied by long-term serotonergic neurotoxicity, which is associated with reduced density of cerebral serotonin transporters (SERT) and depressive disorders. Resveratrol (RSV) is a natural polyphenolic phytoalexin that has been known for its antidepressant and neuroprotective effects. However, biological targets of RSV as well as its neuroprotective effects against MDMA remained largely unknown. In this study, we examined binding potency of RSV and MDMA to SERT using small-animal positron emission tomography (PET) with the SERT radioligand, N,N-dimethyl-2-(2-amino-4-[(18)F]fluorophenylthio)benzylamine (4-[(18)F]-ADAM) and investigated the protection of RSV against the acute and long-term adverse effects of MDMA. We found that RSV exhibit binding potentials to SERT in vivo in a dose-dependent manner with variation among brain regions. When the MDMA-treated rats (10mg/kg, s.c.) were co-injected with RSV (20mg/kg, i.p.) twice daily for 4 consecutive days, MDMA-induced acute elevation in plasma corticosterone was significantly reduced. Further, 4-[(18)F]-ADAM PET imaging revealed that RSV protected against the MDMA-induced decrease in SERT availability in the midbrain and the thalamus 2 weeks following the co-treatment. The PET data were comparable to the observation from the forced swim test that RSV sufficiently ameliorated the depressive-like behaviors of the MDMA-treated rats. Together, these findings suggest that RSV is a potential antidepressant and may confer protection against neurobiological and behavioral changes induced by MDMA. Copyright © 2015 Elsevier B.V. and ECNP. All rights reserved.

  20. Animals

    International Nuclear Information System (INIS)

    Skuterud, L.; Strand, P.; Howard, B.J.

    1997-01-01

    The radionuclides of most concern with respect to contamination of animals after a nuclear accident are radioiodine, radiocaesium and radiostrontium (ICRP 30, 1979). Of the other significant anthropogenic radionuclides likely to be released in most accidents, only small proportions of that ingested will be absorbed in an animals gut, and the main animal products, milk and meat, will not normally be contaminated to a significant extent. Animal products will mostly be contaminated as a result of ingestion of contaminated feed and possibly, but to a much lesser extent, from inhalation (for radioiodine only). Direct external contamination of animals is of little or no consequence in human food production. Radioiodine and radiostrontium are important with respect to contamination of milk; radiocaesium contaminates both milk and meat. The physical and chemical form of a radionuclide can influence its absorption in the animal gut. For example, following the Chernobyl accident radiocaesium incorporated into vegetation by root uptake was more readily absorbed than that associated with the original deposit. The transfer of radiocaesium and radiostrontium to animals will be presented both as transfer coefficients and aggregated transfer coefficients. For most animal meat products, only radiocaesium is important as other radionuclides do not significantly contaminate muscle. Farm animal products are the most important foodstuff determining radiocaesium intake by the average consumer in the Nordic countries. The major potential source of radioiodine and radiostrontium to humans is milk and milk products. Of the different species, the smaller animals have the highest transfer of radiocaesium from fodder to meat and milk. (EG)

  1. Influence of Animal Heating on PET Imaging Quantification and Kinetics: Biodistribution of 18F-Tetrafluoroborate and 18F-FDG in Mice.

    Science.gov (United States)

    Goetz, Christian; Podein, Matthias; Braun, Friederike; Weber, Wolfgang A; Choquet, Philippe; Constantinesco, André; Mix, Michael

    2017-07-01

    Different environmental conditions under anesthesia may lead to unstable homeostatic conditions in rodents and therefore may alter kinetics. In this study, the impact of different heating conditions on PET imaging quantification was evaluated. Methods: Two groups of 6 adult female BALB/c nude mice with subcutaneously implanted tumors underwent microPET imaging after injection of 18 F-labeled tetrafluoroborate or 18 F-FDG. Dynamic scans were acquired under optimal and suboptimal heating conditions. Time-activity curves were analyzed to calculate uptake and washout time constants. Results: With 18 F-labeled tetrafluoroborate, optimal animal heating led to a stable heart rate during acquisition (515 ± 35 [mean ± SD] beats/min), whereas suboptimal heating led to a lower heart rate and a higher SD (470 ± 84 beats/min). Both uptake and washout time constants were faster ( P heating. Conclusion: Although the difference in heart rates was slight, optimal heating yielded significantly faster uptake and washout kinetics than suboptimal heating in all organs for both tracers. © 2017 by the Society of Nuclear Medicine and Molecular Imaging.

  2. Experimental Approach to Evaluate the 11C Perfusion and Diffusion in Small Animal Tissues for HadronPET Applications.

    Directory of Open Access Journals (Sweden)

    Immaculada Martínez-Rovira

    Full Text Available The development of a reliable dose monitoring system in hadron therapy is essential in order to control the treatment plan delivery. Positron Emission Tomography (PET is the only method used in clinics nowadays for quality assurance. However, the accuracy of this method is limited by the loss of signal due to the biological washout processes. Up to the moment, very few studies measured the washout processes and there is no database of washout data as a function of the tissue and radioisotope. One of the main difficulties is related to the complexity of such measurements, along with the limited time slots available in hadron therapy facilities. Thus, in this work, we proposed an alternative in vivo methodology for the measurement and modeling of the biological washout parameters without any radiative devices. It consists in the implementation of a point-like radioisotope source by direct injection on the tissues of interest and its measurement by means of high-resolution preclinical PET systems. In particular, the washout of 11C carbonate radioisotopes was assessed, considering that 11C is is the most abundant β+ emitter produced by carbon beams. 11C washout measurements were performed in several tissues of interest (brain, muscle and 9L tumor xenograf in rodents (Wistar rat. Results show that the methodology presented is sensitive to the washout variations depending on the selected tissue. Finally, a first qualitative correlation between 11C tumor washout properties and tumor metabolism (via 18F-FDG tracer uptake was found.

  3. Wavelet-based regularization and edge preservation for submillimetre 3D list-mode reconstruction data from a high resolution small animal PET system

    Energy Technology Data Exchange (ETDEWEB)

    Jesus Ochoa Dominguez, Humberto de, E-mail: hochoa@uacj.mx [Departamento de Ingenieria Eectrica y Computacion, Universidad Autonoma de Ciudad Juarez, Avenida del Charro 450 Norte, C.P. 32310 Ciudad Juarez, Chihuahua (Mexico); Ortega Maynez, Leticia; Osiris Vergara Villegas, Osslan; Gordillo Castillo, Nelly; Guadalupe Cruz Sanchez, Vianey; Gutierrez Casas, Efren David [Departamento de Ingenieria Eectrica y Computacion, Universidad Autonoma de Ciudad Juarez, Avenida del Charro 450 Norte, C.P. 32310 Ciudad Juarez, Chihuahua (Mexico)

    2011-10-01

    The data obtained from a PET system tend to be noisy because of the limitations of the current instrumentation and the detector efficiency. This problem is particularly severe in images of small animals as the noise contaminates areas of interest within small organs. Therefore, denoising becomes a challenging task. In this paper, a novel wavelet-based regularization and edge preservation method is proposed to reduce such noise. To demonstrate this method, image reconstruction using a small mouse {sup 18}F NEMA phantom and a {sup 18}F mouse was performed. Investigation on the effects of the image quality was addressed for each reconstruction case. Results show that the proposed method drastically reduces the noise and preserves the image details.

  4. 21 CFR 570.14 - Indirect food additives resulting from packaging materials for animal feed and pet food.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Indirect food additives resulting from packaging..., DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES General Provisions § 570.14 Indirect food additives resulting from packaging materials for animal feed and...

  5. Is Animal Cruelty a "Red Flag" for Family Violence? Investigating Co-Occurring Violence toward Children, Partners, and Pets

    Science.gov (United States)

    DeGue, Sarah; DiLillo, David

    2009-01-01

    Cross-reporting legislation, which permits child and animal welfare investigators to refer families with substantiated child maltreatment or animal cruelty for investigation by parallel agencies, has recently been adopted in several U.S. jurisdictions. The current study sheds light on the underlying assumption of these policies--that animal…

  6. Animals

    Energy Technology Data Exchange (ETDEWEB)

    Skuterud, L.; Strand, P. [Norwegian Radiation Protection Authority (Norway); Howard, B.J. [Inst. of Terrestrial Ecology (United Kingdom)

    1997-10-01

    The radionuclides of most concern with respect to contamination of animals after a nuclear accident are radioiodine, radiocaesium and radiostrontium (ICRP 30, 1979). Of the other significant anthropogenic radionuclides likely to be released in most accidents, only small proportions of that ingested will be absorbed in an animals gut, and the main animal products, milk and meat, will not normally be contaminated to a significant extent. Animal products will mostly be contaminated as a result of ingestion of contaminated feed and possibly, but to a much lesser extent, from inhalation (for radioiodine only). Direct external contamination of animals is of little or no consequence in human food production. Radioiodine and radiostrontium are important with respect to contamination of milk; radiocaesium contaminates both milk and meat. The physical and chemical form of a radionuclide can influence its absorption in the animal gut. For example, following the Chernobyl accident radiocaesium incorporated into vegetation by root uptake was more readily absorbed than that associated with the original deposit. The transfer of radiocaesium and radiostrontium to animals will be presented both as transfer coefficients and aggregated transfer coefficients. For most animal meat products, only radiocaesium is important as other radionuclides do not significantly contaminate muscle. Farm animal products are the most important foodstuff determining radiocaesium intake by the average consumer in the Nordic countries. The major potential source of radioiodine and radiostrontium to humans is milk and milk products. Of the different species, the smaller animals have the highest transfer of radiocaesium from fodder to meat and milk. (EG). 68 refs.

  7. Construction and tests of demonstrator modules for a 3-D axial PET system for brain or small animal imaging

    CERN Document Server

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

    2011-01-01

    The design and construction of a PET camera module with high sensitivity, full 3-D spatial reconstruction and very good energy resolution is presented. The basic principle consists of an axial arrangement of long scintillation crystals around the Field Of View (FOV), providing a measurement of the transverse coordinates of the interacting 511 keV gamma ray. On top of each layer of crystals, an array of Wave-Length Shifter (WLS) strips, which collect the light leaving the crystals sideways, is positioned orthogonal to the crystal direction. The signals in the WLS strips allow a precise measurement of the z (axial) co-ordinate of the 511 keV gamma-ray gamma impact. The construction of two modules used for demonstration of the concept is described. First preliminary results on spatial and energy resolution from one full module will be shown. (C) 2010 Elsevier B.V. All rights reserved.

  8. Fully 3D GPU PET reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Herraiz, J.L., E-mail: joaquin@nuclear.fis.ucm.es [Grupo de Fisica Nuclear, Departmento 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); Cal-Gonzalez, J. [Grupo de Fisica Nuclear, Departmento Fisica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid (Spain); Vaquero, J.J. [Departmento de Bioingenieria e Ingenieria Espacial, Universidad Carlos III, Madrid (Spain); Desco, M. [Departmento de Bioingenieria e Ingenieria Espacial, Universidad Carlos III, Madrid (Spain); Unidad de Medicina y Cirugia Experimental, Hospital General Universitario Gregorio Maranon, Madrid (Spain); Udias, J.M. [Grupo de Fisica Nuclear, Departmento Fisica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid (Spain)

    2011-08-21

    Fully 3D iterative tomographic image reconstruction is computationally very demanding. Graphics Processing Unit (GPU) has been proposed for many years as potential accelerators in complex scientific problems, but it has not been used until the recent advances in the programmability of GPUs that the best available reconstruction codes have started to be implemented to be run on GPUs. This work presents a GPU-based fully 3D PET iterative reconstruction software. This new code may reconstruct sinogram data from several commercially available PET scanners. The most important and time-consuming parts of the code, the forward and backward projection operations, are based on an accurate model of the scanner obtained with the Monte Carlo code PeneloPET and they have been massively parallelized on the GPU. For the PET scanners considered, the GPU-based code is more than 70 times faster than a similar code running on a single core of a fast CPU, obtaining in both cases the same images. The code has been designed to be easily adapted to reconstruct sinograms from any other PET scanner, including scanner prototypes.

  9. Scanner image quality profiling

    Science.gov (United States)

    Cui, Chengwu

    2009-01-01

    When using a document scanner, scan image quality is often unknown to the end user of the scanned image. Document scanners may employ different imaging technologies that can result in different image characteristics. Variability of scanner parts and the manufacturing process may also create variability of the scanned image quality from machine to machine. Image quality of the same scanner may also change as it ages and becomes contaminated. If the scanned image is used for human viewing, the resulting image quality variability may not be mission critical other than being a visual annoyance because the human visual system has superb adaptation and segmentation capability. However, if the scanned image is used for machine recognition or for printing, the image quality variability may become important and even mission critical. Here we propose a framework to profile the scanner image quality and tag the scanned image with the IQ profile. We review the potential quantified aspects of scan image quality and propose a method of characterization with examples.

  10. Development of a positron emission mammography scanner for breast cancer detection

    International Nuclear Information System (INIS)

    Belcari, Nicola

    2004-01-01

    a tumor-to-background uptake ratio of 10:1. An experimental study on a dual head system, based on the small animal YAP-(S)PET scanner, has been simulated, so as to validate the Monte Carlo code. The results obtained support that the YAP-PEM scanner under development could be a valuable tool for breast cancer investigation, showing excellent performance, similar or better than that of other existing (or in development) Positron Emission Mammography systems

  11. Comparison of PET/CT with Sequential PET/MRI Using an MR-Compatible Mobile PET System.

    Science.gov (United States)

    Nakamoto, Ryusuke; Nakamoto, Yuji; Ishimori, Takayoshi; Fushimi, Yasutaka; Kido, Aki; Togashi, Kaori

    2018-05-01

    The current study tested a newly developed flexible PET (fxPET) scanner prototype. This fxPET system involves dual arc-shaped detectors based on silicon photomultipliers that are designed to fit existing MRI devices, allowing us to obtain fused PET and MR images by sequential PET and MR scanning. This prospective study sought to evaluate the image quality, lesion detection rate, and quantitative values of fxPET in comparison with conventional whole-body (WB) PET and to assess the accuracy of registration. Methods: Seventeen patients with suspected or known malignant tumors were analyzed. Approximately 1 h after intravenous injection of 18 F-FDG, WB PET/CT was performed, followed by fxPET and MRI. For reconstruction of fxPET images, MRI-based attenuation correction was applied. The quality of fxPET images was visually assessed, and the number of detected lesions was compared between the 2 imaging methods. SUV max and maximum average SUV within a 1 cm 3 spheric volume (SUV peak ) of lesions were also compared. In addition, the magnitude of misregistration between fxPET and MR images was evaluated. Results: The image quality of fxPET was acceptable for diagnosis of malignant tumors. There was no significant difference in detectability of malignant lesions between fxPET and WB PET ( P > 0.05). However, the fxPET system did not exhibit superior performance to the WB PET system. There were strong positive correlations between the 2 imaging modalities in SUV max (ρ = 0.88) and SUV peak (ρ = 0.81). SUV max and SUV peak measured with fxPET were approximately 1.1-fold greater than measured with WB PET. The average misregistration between fxPET and MR images was 5.5 ± 3.4 mm. Conclusion: Our preliminary data indicate that running an fxPET scanner near an existing MRI system provides visually and quantitatively acceptable fused PET/MR images for diagnosis of malignant lesions. © 2018 by the Society of Nuclear Medicine and Molecular Imaging.

  12. In vivo PET imaging of implanted cells in a Parkinson's disease rat model

    International Nuclear Information System (INIS)

    Wang Ruimin; Guo Zhe; Zhang Jinming; Shen Li; Shang Aijia; Chen Yingmao; Yao Shulin; Yin Dayi; Tian Jiahe

    2008-01-01

    Objective: It is a major hurdle for the researchers to mornitor the implanted cells differentiation in vivo. This study was designed as a proof of concept of the feasibility to track the efficacy of transplanted human retinal pigment epithelial (RPE) cells in a Parkinson's disease (PD) rat model using PET. Methods: RPE cells or normal saline were injected into striatum of the injured side of the models in treated group(12 rats) and control group(11 rats), respectively. PET imaging on both groups was under- taken before and at certain intervals after the transplantation using 11 C-raclopride and 11 C-CFT as the markers. Behavioral observation and immunofluorescence confocal microscopy also conducted to prove PET results. Results: PET studies showed increased 11 C-raclopride accumulation and decreased 11 C-CFT in the injured side of striatum in both groups before transplantation. The 11 C-raclopride striatum/cerebellum ratio at ipsilateral side decreased from 1.870 ± 0.465 to 1.601 ± 0.257 after transplantation, along with a concomitant increase of 11 C-CFT accumulation in the same area (1.827 ± 0.347 to 2.336 ± 0.326) in treated group. The changes of PET studies paralleled the behavior states and confocal microscopic observations in the treated animals. Conclusion: Even a clinical PET scanner could provide to certain extent some information on the existence and in vivo differentiation of RPE cells in a PD rat model. (authors)

  13. Twelve automated thresholding methods for segmentation of PET images: a phantom study

    Science.gov (United States)

    Prieto, Elena; Lecumberri, Pablo; Pagola, Miguel; Gómez, Marisol; Bilbao, Izaskun; Ecay, Margarita; Peñuelas, Iván; Martí-Climent, Josep M.

    2012-06-01

    Tumor volume delineation over positron emission tomography (PET) images is of great interest for proper diagnosis and therapy planning. However, standard segmentation techniques (manual or semi-automated) are operator dependent and time consuming while fully automated procedures are cumbersome or require complex mathematical development. The aim of this study was to segment PET images in a fully automated way by implementing a set of 12 automated thresholding algorithms, classical in the fields of optical character recognition, tissue engineering or non-destructive testing images in high-tech structures. Automated thresholding algorithms select a specific threshold for each image without any a priori spatial information of the segmented object or any special calibration of the tomograph, as opposed to usual thresholding methods for PET. Spherical 18F-filled objects of different volumes were acquired on clinical PET/CT and on a small animal PET scanner, with three different signal-to-background ratios. Images were segmented with 12 automatic thresholding algorithms and results were compared with the standard segmentation reference, a threshold at 42% of the maximum uptake. Ridler and Ramesh thresholding algorithms based on clustering and histogram-shape information, respectively, provided better results that the classical 42%-based threshold (p < 0.05). We have herein demonstrated that fully automated thresholding algorithms can provide better results than classical PET segmentation tools.

  14. 7 CFR 503.11 - Pets.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 6 2010-01-01 2010-01-01 false Pets. 503.11 Section 503.11 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL RESEARCH SERVICE, DEPARTMENT OF AGRICULTURE CONDUCT ON PLUM ISLAND ANIMAL DISEASE CENTER § 503.11 Pets. No pets or animals of any kind may be brought...

  15. Living on a farm, contact with farm animals and pets, and childhood acute lymphoblastic leukemia: pooled and meta-analyses from the Childhood Leukemia International Consortium.

    Science.gov (United States)

    Orsi, Laurent; Magnani, Corrado; Petridou, Eleni T; Dockerty, John D; Metayer, Catherine; Milne, Elizabeth; Bailey, Helen D; Dessypris, Nick; Kang, Alice Y; Wesseling, Catharina; Infante-Rivard, Claire; Wünsch-Filho, Victor; Mora, Ana M; Spector, Logan G; Clavel, Jacqueline

    2018-04-16

    The associations between childhood acute lymphoblastic leukemia (ALL) and several factors related to early stimulation of the immune system, that is, farm residence and regular contacts with farm animals (livestock, poultry) or pets in early childhood, were investigated using data from 13 case-control studies participating in the Childhood Leukemia International Consortium. The sample included 7847 ALL cases and 11,667 controls aged 1-14 years. In all studies, the data were obtained from case and control parents using standardized questionnaires. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were estimated by unconditional logistic regression adjusted for age, sex, study, maternal education, and maternal age. Contact with livestock in the first year of life was inversely associated with ALL (OR = 0.65, 95% CI: 0.50, 0.85). Inverse associations were also observed for contact with dogs (OR = 0.92, 95% CI: 0.86, 0.99) and cats (OR = 0.87, 95% CI: 0.80, 0.94) in the first year of life. There was no evidence of a significant association with farm residence in the first year of life. The findings of these large pooled and meta-analyses add additional evidence to the hypothesis that regular contact with animals in early childhood is inversely associated with childhood ALL occurrence which is consistent with Greaves' delayed infection hypothesis. © 2018 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

  16. Evaluation of the co-registration capabilities of a MRI/PET compatible bed in an Experimental autoimmune encephalomyelitis (EAE) model

    Energy Technology Data Exchange (ETDEWEB)

    Esposito, Giovanna, E-mail: giovanna.esposito@unito.it [Molecular and Preclinical Imaging Center, University of Torino (Italy); D' angeli, Luca; Bartoli, Antonietta [Molecular and Preclinical Imaging Center, University of Torino (Italy); Chaabane, Linda [INSPE-Division of Neuroscience, San Raffaele Scientific Institute, 20132 Milano (Italy); Terreno, Enzo [Molecular and Preclinical Imaging Center, University of Torino (Italy)

    2013-02-21

    Positron Emission Tomography (PET) with {sup 18}F-FDG is a promising tool for the detection and evaluation of active inflammation in animal models of neuroinflammation. MRI is a complementary imaging technique with high resolution and contrast suitable to obtain the anatomical data required to analyze PET data. To combine PET and MRI modalities, we developed a support bed system compatible for both scanners that allowed to perform imaging exams without animal repositioning. With this approach, MRI and PET data were acquired in mice with Experimental autoimmune encephalomyelitis (EAE). In this model, it was possible to measure a variation of {sup 18}F-FDG uptake proportional to the degree of disease severity which is mainly related to Central Nervous System (CNS) inflammation. Against the low resolved PET images, the co-registered MRI/PET images allowed to distinguish the different brain structures and to obtain a more accurate tracer evaluation. This is essential in particular for brain regions whose size is of the order of the spatial resolution of PET.

  17. Evaluation of the co-registration capabilities of a MRI/PET compatible bed in an Experimental autoimmune encephalomyelitis (EAE) model

    Science.gov (United States)

    Esposito, Giovanna; D'angeli, Luca; Bartoli, Antonietta; Chaabane, Linda; Terreno, Enzo

    2013-02-01

    Positron Emission Tomography (PET) with 18F-FDG is a promising tool for the detection and evaluation of active inflammation in animal models of neuroinflammation. MRI is a complementary imaging technique with high resolution and contrast suitable to obtain the anatomical data required to analyze PET data. To combine PET and MRI modalities, we developed a support bed system compatible for both scanners that allowed to perform imaging exams without animal repositioning. With this approach, MRI and PET data were acquired in mice with Experimental autoimmune encephalomyelitis (EAE). In this model, it was possible to measure a variation of 18F-FDG uptake proportional to the degree of disease severity which is mainly related to Central Nervous System (CNS) inflammation. Against the low resolved PET images, the co-registered MRI/PET images allowed to distinguish the different brain structures and to obtain a more accurate tracer evaluation. This is essential in particular for brain regions whose size is of the order of the spatial resolution of PET.

  18. Performance analysis of different PSF shapes for the quad-HIDAC PET submillimetre resolution recovery

    Energy Technology Data Exchange (ETDEWEB)

    Ortega Maynez, Leticia, E-mail: lortega@uacj.mx [Departamento de Ingenieria Eectrica y Computacion , Universidad Autonoma de Ciudad Juarez, Avenida del Charro 450 Norte, C.P. 32310 Ciudad Juarez, Chihuahua (Mexico); Dominguez de Jesus Ochoa, Humberto; Villegas Osiris Vergara, Osslan; Gordillo, Nelly; Guadalupe Cruz Sanchez, Vianey; Gutierrez Casas, Efren David [Departamento de Ingenieria Eectrica y Computacion, Universidad Autonoma de Ciudad Juarez, Avenida del Charro 450 Norte, C.P. 32310 Ciudad Juarez, Chihuahua (Mexico)

    2011-10-01

    In pre-clinical applications, it is quite important to preserve the image resolution because it is necessary to show the details of structures of small animals. Therefore, small animal PET scanners require high spatial resolution and good sensitivity. For the quad-HIDAC PET scanner, which has virtually continuous spatial sampling; improvements in resolution, noise and contrast are obtained as a result of avoiding artifacts introduced by binning the data into sampled projections used during the reconstruction process. In order to reconstruct high-resolution images in 3D-PET, background correction and resolution recovery are included within the Maximum Likelihood list-mode Expectation Maximization reconstruction model. This paper, introduces the performance analysis of the Gaussian, Laplacian and Triangular kernels. The Full-Width Half-Maximum used for each kernel was varied from 0.8 to 1.6 mm. For each quality compartment within the phantom, transaxial middle slices from the 3D reconstructed images are shown. Results show that, according to the quantitative measures, the triangular kernel has the best performance.

  19. Ionization beam scanner

    CERN Multimedia

    CERN PhotoLab

    1973-01-01

    Inner structure of an ionization beam scanner, a rather intricate piece of apparatus which permits one to measure the density distribution of the proton beam passing through it. On the outside of the tank wall there is the coil for the longitudinal magnetic field, on the inside, one can see the arrangement of electrodes creating a highly homogeneous transverse electric field.

  20. An analysis of the demand for and revenue from companion animal veterinary services in Australia between 1996 and 2026 using industry revenue data and household census and pet ownership data and forecasts.

    Science.gov (United States)

    Baguley, J

    2011-09-01

    OBJECTIVE To examine the potential impact of household demographic and pet ownership trends on the demand for and revenue from companion animal veterinary services in Australia. DESIGN The size of the market for companion animal veterinary services was estimated by creating a model using assumptions derived from the revenue equation. The model was verified and validated through sensitivity analyses and comparisons between model outputs and available industry data. RESULTS The model provided outputs similar to alternative industry estimates and suggested that revenue growth in recent years has been much stronger than demand growth. Under the assumptions used in this model, forecast changes to household numbers and types are less important than pet ownership trends in determining the potential demand for and revenue from companion animal veterinary services. Forecast trends in household types and relatively stable pet ownership in the future will lead to growth in demand for companion animal veterinary services in real terms of approximately 1.2% per annum to 2026. CONCLUSION The market for companion animal veterinary services in Australia is mature and growth in demand is expected to remain low over the forecast period. For most veterinary practices within this environment, growth in revenue will be a function of growth in average client fees. © 2011 The Author. Australian Veterinary Journal © 2011 Australian Veterinary Association.

  1. P.I.X.S.C.A.N.: a micro-CT scanner for small animal based on hybrid pixel detectors; PIXSCAN: micro-tomodensitrometre a pixels hybrides pour le petit animal

    Energy Technology Data Exchange (ETDEWEB)

    Khoury, R

    2008-03-15

    Since more than a dozen years, efforts were led in the field of X-ray tomography for small animals, principally for the improvement of spatial resolution and the diminution of the absorbed dose. The C.P.P.M. developed the micro-CT P.I.X.S.C.A.N. based on the hybrid pixel detector X.P.A.D.2. In this context, my thesis work consists in studying the demonstrator P.I.X.S.C.A.N./X.P.A.D.2 and the contribution of the hybrid pixels in the imaging of small animals. A fast analytical simulation, FastSimu, was developed. An extrapolation of the performance of the demonstrator P.I.X.S.C.A.N, as well as the validation of the results obtained with the measured data, were led by means of the analytical simulator FastSimu. The demonstrator P.I.X.S.C.A.N./X.P.A.D.2 allowed to obtain reconstructed images with a rather good quality for a relatively weak absorbed dose. Its spatial resolution is degraded by the high number of defective pixels of the detector X.P.A.D.2. Beyond this study, a new version of the demonstrator P.I.X.S.C.A.N./X.P.A.D.2 is under construction. This latter, characterized by two and a half times smaller pixels and about no defective pixels will bring a considerable improvement on spatial resolution. (author)

  2. Scanner calibration revisited

    Directory of Open Access Journals (Sweden)

    Pozhitkov Alexander E

    2010-07-01

    Full Text Available Abstract Background Calibration of a microarray scanner is critical for accurate interpretation of microarray results. Shi et al. (BMC Bioinformatics, 2005, 6, Art. No. S11 Suppl. 2. reported usage of a Full Moon BioSystems slide for calibration. Inspired by the Shi et al. work, we have calibrated microarray scanners in our previous research. We were puzzled however, that most of the signal intensities from a biological sample fell below the sensitivity threshold level determined by the calibration slide. This conundrum led us to re-investigate the quality of calibration provided by the Full Moon BioSystems slide as well as the accuracy of the analysis performed by Shi et al. Methods Signal intensities were recorded on three different microarray scanners at various photomultiplier gain levels using the same calibration slide from Full Moon BioSystems. Data analysis was conducted on raw signal intensities without normalization or transformation of any kind. Weighted least-squares method was used to fit the data. Results We found that initial analysis performed by Shi et al. did not take into account autofluorescence of the Full Moon BioSystems slide, which led to a grossly distorted microarray scanner response. Our analysis revealed that a power-law function, which is explicitly accounting for the slide autofluorescence, perfectly described a relationship between signal intensities and fluorophore quantities. Conclusions Microarray scanners respond in a much less distorted fashion than was reported by Shi et al. Full Moon BioSystems calibration slides are inadequate for performing calibration. We recommend against using these slides.

  3. Radiolabeling optimization and characterization of 68Ga labeled DOTA–polyamido-amine dendrimer conjugate – Animal biodistribution and PET imaging results

    International Nuclear Information System (INIS)

    Ghai, Aanchal; Singh, Baljinder; Panwar Hazari, Puja; Schultz, Michael K.; Parmar, Ambika; Kumar, Pardeep; Sharma, Sarika; Dhawan, Devinder; Kumar Mishra, Anil

    2015-01-01

    The present study describes the optimization of 68 Ga radiolabeling with PAMAM dendrimer–DOTA conjugate. A conjugate (PAMAM–DOTA) concentration of 11.69 µM, provided best radiolabeling efficiency of more than 93.0% at pH 4.0, incubation time of 30.0 min and reaction temperature ranging between 90 and 100 °C. The decay corrected radiochemical yield was found to be 79.4±0.01%. The radiolabeled preparation ([ 68 Ga]-DOTA–PAMAM-D) remained stable (radiolabeling efficiency of 96.0%) at room temperature and in serum for up to 4-h. The plasma protein binding was observed to be 21.0%. After intravenous administration, 50.0% of the tracer cleared from the blood circulation by 30-min and less than 1.0% of the injected activity remained in blood by 1.0 h. The animal biodistribution studies demonstrated that the tracer excretes through the kidneys and about 0.33% of the %ID/g accumulated in the tumor at 1 h post injection. The animal organ's biodistribution data was supported by animal PET imaging showing good ‘non-specific’ tracer uptake in tumor and excretion is primarily through kidneys. Additionally, DOTA–PAMAM-D conjugation with α V β 3 receptors targeting peptides and drug loading on the dendrimers may improve the specificity of the 68 Ga labeled product for imaging and treating angiogenesis respectively. - Highlights: • Chemical conjugation of G-4 PAMAM dendrimers with DOTA-NHS carried out successfully. • Purification and characterization of the conjugate was done by SEC and MALDI-TOF. • Radiolabeling of PAMAM-DOTA-conjugate with 68Ga yielded high radiolabeling efficiency. • [ 68 Ga] DOTA–PAMAM-Dhas rapid blood clearance and excreted mainly through the kidneys. • No significant retention of the radiotracer was seen in any other organ.

  4. A proposal of an open PET geometry

    Energy Technology Data Exchange (ETDEWEB)

    Yamaya, Taiga [Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555 (Japan); Inaniwa, Taku [Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Minohara, Shinichi [Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Yoshida, Eiji [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); Nishikido, Fumihiko [Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555 (Japan); Shibuya, Kengo [Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555 (Japan); Lam, Chih Fung [Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555 (Japan); Murayama, Hideo [Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555 (Japan)

    2008-02-07

    The long patient port of a PET scanner tends to put stress on patients, especially patients with claustrophobia. It also prevents doctors and technicians from taking care of patients during scanning. In this paper, we proposed an 'open PET' geometry, which consists of two axially separated detector rings. A long and continuous field-of-view (FOV) including a 360 deg. opened gap between two detector rings can be imaged enabling a fully 3D image reconstruction of all the possible lines-of-response. The open PET will become practical if iterative image reconstruction methods are applied even though image reconstruction of the open PET is analytically an incomplete problem. First we implemented a 'masked' 3D ordered subset expectation maximization (OS-EM) in which the system matrix was obtained from a long 'gapless' scanner by applying a mask to detectors corresponding to the open space. Next, in order to evaluate imaging performance of the proposed open PET geometry, we simulated a dual HR+ scanner (ring diameter of D = 827 mm, axial length of W = 154 mm x 2) separated by a variable gap. The gap W was the maximum limit to have axially continuous FOV of 3W though the maximum diameter of FOV at the central slice was limited to D/2. Artifacts, observed on both sides of the open space when the gap exceeded W, were effectively reduced by inserting detectors partially into unnecessary open spaces. We also tested the open PET geometry using experimental data obtained by the jPET-D4. The jPET-D4 is a prototype brain scanner, which has 5 rings of 24 detector blocks. We simulated the open jPET-D4 with a gap of 66 mm by eliminating 1 block-ring from experimental data. Although some artifacts were seen at both ends of the opened gap, very similar images were obtained with and without the gap. The proposed open PET geometry is expected to lead to realization of in-beam PET, which is a method for an in situ monitoring of charged particle therapy, by

  5. 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)

  6. Attenuation correction for the large non-human primate brain imaging using microPET

    Science.gov (United States)

    Naidoo-Variawa, S.; Lehnert, W.; Kassiou, M.; Banati, R.; Meikle, S. R.

    2010-04-01

    Assessment of the biodistribution and pharmacokinetics of radiopharmaceuticals in vivo is often performed on animal models of human disease prior to their use in humans. The baboon brain is physiologically and neuro-anatomically similar to the human brain and is therefore a suitable model for evaluating novel CNS radioligands. We previously demonstrated the feasibility of performing baboon brain imaging on a dedicated small animal PET scanner provided that the data are accurately corrected for degrading physical effects such as photon attenuation in the body. In this study, we investigated factors affecting the accuracy and reliability of alternative attenuation correction strategies when imaging the brain of a large non-human primate (papio hamadryas) using the microPET Focus 220 animal scanner. For measured attenuation correction, the best bias versus noise performance was achieved using a 57Co transmission point source with a 4% energy window. The optimal energy window for a 68Ge transmission source operating in singles acquisition mode was 20%, independent of the source strength, providing bias-noise performance almost as good as for 57Co. For both transmission sources, doubling the acquisition time had minimal impact on the bias-noise trade-off for corrected emission images, despite observable improvements in reconstructed attenuation values. In a [18F]FDG brain scan of a female baboon, both measured attenuation correction strategies achieved good results and similar SNR, while segmented attenuation correction (based on uncorrected emission images) resulted in appreciable regional bias in deep grey matter structures and the skull. We conclude that measured attenuation correction using a single pass 57Co (4% energy window) or 68Ge (20% window) transmission scan achieves an excellent trade-off between bias and propagation of noise when imaging the large non-human primate brain with a microPET scanner.

  7. Attenuation correction for the large non-human primate brain imaging using microPET

    International Nuclear Information System (INIS)

    Naidoo-Variawa, S; Lehnert, W; Kassiou, M; Banati, R; Meikle, S R

    2010-01-01

    Assessment of the biodistribution and pharmacokinetics of radiopharmaceuticals in vivo is often performed on animal models of human disease prior to their use in humans. The baboon brain is physiologically and neuro-anatomically similar to the human brain and is therefore a suitable model for evaluating novel CNS radioligands. We previously demonstrated the feasibility of performing baboon brain imaging on a dedicated small animal PET scanner provided that the data are accurately corrected for degrading physical effects such as photon attenuation in the body. In this study, we investigated factors affecting the accuracy and reliability of alternative attenuation correction strategies when imaging the brain of a large non-human primate (papio hamadryas) using the microPET Focus 220 animal scanner. For measured attenuation correction, the best bias versus noise performance was achieved using a 57 Co transmission point source with a 4% energy window. The optimal energy window for a 68 Ge transmission source operating in singles acquisition mode was 20%, independent of the source strength, providing bias-noise performance almost as good as for 57 Co. For both transmission sources, doubling the acquisition time had minimal impact on the bias-noise trade-off for corrected emission images, despite observable improvements in reconstructed attenuation values. In a [ 18 F]FDG brain scan of a female baboon, both measured attenuation correction strategies achieved good results and similar SNR, while segmented attenuation correction (based on uncorrected emission images) resulted in appreciable regional bias in deep grey matter structures and the skull. We conclude that measured attenuation correction using a single pass 57 Co (4% energy window) or 68 Ge (20% window) transmission scan achieves an excellent trade-off between bias and propagation of noise when imaging the large non-human primate brain with a microPET scanner.

  8. Standardised uptake values from PET/CT images: comparison with conventional attenuation-corrected PET

    International Nuclear Information System (INIS)

    Souvatzoglou, M.; Ziegler, S.I.; Martinez, M.J.; Dzewas, G.; Schwaiger, M.; Bengel, F.; Busch, R.

    2007-01-01

    In PET/CT, CT-derived attenuation factors may influence standardised uptake values (SUVs) in tumour lesions and organs when compared with stand-alone PET. Therefore, we compared PET/CT-derived SUVs intra-individually in various organs and tumour lesions with stand-alone PET-derived SUVs. Thirty-five patients with known or suspected cancer were prospectively included. Sixteen patients underwent FDG PET using an ECAT HR+scanner, and subsequently a second scan using a Biograph Sensation 16PET/CT scanner. Nineteen patients were scanned in the reverse order. All images were reconstructed with an iterative algorithm (OSEM). Suspected lesions were grouped as paradiaphragmatic versus distant from the diaphragm. Mean and maximum SUVs were also calculated for brain, lung, liver, spleen and vertebral bone. The attenuation coefficients (μ values) used for correction of emission data (bone, soft tissue, lung) in the two data sets were determined. A body phantom containing six hot spheres and one cold cylinder was measured using the same protocol as in patients. Forty-six lesions were identified. There was a significant correlation of maximum and mean SUVs derived from PET and PET/CT for 14 paradiaphragmatic lesions (r=0.97 respectively; p<0.001 respectively) and for 32 lesions located distant from the diaphragm (r=0.87 and r=0.89 respectively; p<0.001 respectively). No significant differences were observed in the SUVs calculated with PET and PET/CT in the lesions or in the organs. In the phantom, radioactivity concentration in spheres calculated from PET and from PET/CT correlated significantly (r=0.99; p<0.001). SUVs of cancer lesions and normal organs were comparable between PET and PET/CT, supporting the usefulness of PET/CT-derived SUVs for quantification of tumour metabolism. (orig.)

  9. Automatic extraction of forward stroke volume using dynamic PET/CT

    DEFF Research Database (Denmark)

    Harms, Hans; Tolbod, Lars Poulsen; Hansson, Nils Henrik

    Background: Dynamic PET can be used to extract forward stroke volume (FSV) by the indicator dilution principle. The technique employed can be automated and is in theory independent on the tracer used and may therefore be added to any dynamic cardiac PET protocol. The aim of this study was to vali......Background: Dynamic PET can be used to extract forward stroke volume (FSV) by the indicator dilution principle. The technique employed can be automated and is in theory independent on the tracer used and may therefore be added to any dynamic cardiac PET protocol. The aim of this study...... was to validate automated methods for extracting FSV directly from dynamic PET studies for two different tracers and to examine potential scanner hardware bias. Methods: 21 subjects underwent a dynamic 27 min 11C-acetate PET scan on a Siemens Biograph TruePoint 64 PET/CT scanner (scanner I). In addition, 8...... subjects underwent a dynamic 6 min 15O-water PET scan followed by a 27 min 11C-acetate PET scan on a GE Discovery ST PET/CT scanner (scanner II). The LV-aortic time-activity curve (TAC) was extracted automatically from dynamic PET data using cluster analysis. The first-pass peak was isolated by automatic...

  10. Influence of PET/CT-introduction on PET scanning frequency and indications. Results of a multicenter study

    International Nuclear Information System (INIS)

    Stergar, H.; Bockisch, A.; Eschmann, S.M.; Krause, B.J.; Roedel, R.; Tiling, R.; Weckesser, M.

    2007-01-01

    Aim: to evaluate the influence of the introduction of combined PET/CT scanners into clinical routine. This investigation addresses the quantitative changes between PET/CT and stand alone PET. Methods: the study included all examinations performed on stand alone PET- or PET/CT-scanners within 12 month prior to and after implementation of PET/CT. The final data analysis included five university hospitals and a total number of 15 497 exams. We distinguished exams on stand alone tomographs prior to and after installation of the combined device as well as PET/CT scans particularly with regard to disease entities. Various further parameters were investigated. Results: the overall number of PET scans (PET and PET/CT) rose by 146% while the number of scans performed on stand alone scanners declined by 22%. Only one site registered an increase in stand alone PET. The number of exams for staging in oncology increased by 196% while that of cardiac scans decreased by 35% and the number of scans in neurology rose by 47%. The use of scans for radiotherapy planning increased to 7% of all PET/CT studies. The increase of procedures for so-called classic PET oncology indications was moderate compared to the more common tumors. An even greater increase was observed in some rare entities. Conclusions: the introduction of PET/CT led to more than a doubling of overall PET procedures with a main focus on oncology. Some of the observed changes in scanning frequency may be caused by a rising availability of new radiotracers and advancements of competing imaging methods. Nevertheless the evident increase in the use of PET/CT for the most common tumour types demonstrates its expanding role in cancer staging. The combination of molecular and morphologic imaging has not only found its place but is still gaining greater importance with new developments in technology and radiochemistry. (orig.)

  11. Preclinical quantitative MicroPET imaging in evaluation of neuroprotective drug candidates

    International Nuclear Information System (INIS)

    Son, Ji Yeon; Kim, Yu Kyeong; Kim, Ji Sun; Lee, Byung Chul; Kim, Kyeong Min; Choi, Tae Hyun; Cheon, Gi Jeong; Lee, Won Woo; Kim, Sang Eun

    2007-01-01

    Using in vivo molecular imaging with microPET/SPECT has been expected to facilitate drug discovery and development. In this study, we applied quantitative microPET to the preclinical evaluation of the effects of two neuroprotective drug candidates to the nigrostriatal dopaminergic neuronal damage. Fifteen SD rats were divided into three groups. The rats of each group were orally administrated one of neuroprotective candidate; NeuProtec (100mg/kg bid) and SureCero (10mg/kg, qd) or normal saline (0.1ml, qd) for 3 weeks. 6-OHDA was sterotactically placed to the right striatum on eighth day after starting while continuing the medication for additional 14 days. [ 124 I]FP-ClT PET scans were obtained using microPET R4 scanner. The behavioral test by amphetamine-induced rotation and the histological examination after thyrosine hydroxylase (TH) immunohistochemical staining were performed. Different uptake in the lesioned striatum among the groups were demonstrated on [ 124 I]FP-CIT PET images. The rats with NeuProtec showed higher binding in the lesion than controls. No differences were observed in SureCere groups. The FP-CIT uptake in the lesioned striatum was well correlated with the % reduction of TH(+) cells (rho =0.73, p=0.025), and also correlated with rotation test (rho =0.79, p=0.001) [ 124 I]FP-CIT animal PET depicted the neuroprotective effects of NeuProtec to the 6-OHDA neurotoxicity in the rat striatum. No demonstrable effect of SureCero might indicate that inadequate dosage was used in this study. MicroPET imaging with small animal could be a great tool in preclinical evaluation of drug efficacy

  12. High resolution reconstruction of PET images using the iterative OSEM algorithm

    International Nuclear Information System (INIS)

    Doll, J.; Bublitz, O.; Werling, A.; Haberkorn, U.; Semmler, W.; Adam, L.E.; Pennsylvania Univ., Philadelphia, PA; Brix, G.

    2004-01-01

    Aim: Improvement of the spatial resolution in positron emission tomography (PET) by incorporation of the image-forming characteristics of the scanner into the process of iterative image reconstruction. Methods: All measurements were performed at the whole-body PET system ECAT EXACT HR + in 3D mode. The acquired 3D sinograms were sorted into 2D sinograms by means of the Fourier rebinning (FORE) algorithm, which allows the usage of 2D algorithms for image reconstruction. The scanner characteristics were described by a spatially variant line-spread function (LSF), which was determined from activated copper-64 line sources. This information was used to model the physical degradation processes in PET measurements during the course of 2D image reconstruction with the iterative OSEM algorithm. To assess the performance of the high-resolution OSEM algorithm, phantom measurements performed at a cylinder phantom, the hotspot Jaszczack phantom, and the 3D Hoffmann brain phantom as well as different patient examinations were analyzed. Results: Scanner characteristics could be described by a Gaussian-shaped LSF with a full-width at half-maximum increasing from 4.8 mm at the center to 5.5 mm at a radial distance of 10.5 cm. Incorporation of the LSF into the iteration formula resulted in a markedly improved resolution of 3.0 and 3.5 mm, respectively. The evaluation of phantom and patient studies showed that the high-resolution OSEM algorithm not only lead to a better contrast resolution in the reconstructed activity distributions but also to an improved accuracy in the quantification of activity concentrations in small structures without leading to an amplification of image noise or even the occurrence of image artifacts. Conclusion: The spatial and contrast resolution of PET scans can markedly be improved by the presented image restauration algorithm, which is of special interest for the examination of both patients with brain disorders and small animals. (orig.)

  13. 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.

  14. Detection and quantification of 14 Campylobacter species in pet dogs reveals an increase in species richness in feces of diarrheic animals

    Directory of Open Access Journals (Sweden)

    Ngeleka Musangu

    2010-03-01

    Full Text Available Abstract Background The genus Campylobacter includes many species, some of which are known human and animal pathogens. Even though studies have repeatedly identified domestic dogs as a risk factor for human campylobacteriosis, our understanding of Campylobacter ecology in this reservoir is limited. Work to date has focused primarily on a limited number of species using culture-based methods. To expand our understanding of Campylobacter ecology in dogs, a collection of fecal samples from 70 healthy and 65 diarrheic pet dogs were examined for the presence and levels of 14 Campylobacter species using quantitative PCR. Results It was found that 58% of healthy dogs and 97% of diarrheic dogs shed detectable levels of Campylobacter spp., with C. coli, C. concisus, C. fetus, C. gracilis, C. helveticus, C. jejuni, C. lari, C. mucosalis, C. showae, C. sputorum and C. upsaliensis levels significantly higher in the diarrheic population. Levels of individual Campylobacter species detected ranged from 103 to 108 organisms per gram of feces. In addition, many individual samples contained multiple species of Campylobacter, with healthy dogs carrying from 0-7 detectable species while diarrheic dogs carried from 0-12 detectable species. Conclusions These findings represent the largest number of Campylobacter species specifically tested for in animals and is the first report to determine quantifiable levels of Campylobacter being shed from dogs. This study demonstrates that domestic dogs can carry a wide range of Campylobacter species naturally and that there is a notable increase in species richness detectable in the diarrheic population. With several of the detected Campylobacter species known or emerging pathogens, these results are relevant to both ecological and public health discussions.

  15. THE PETS:Game Introduction of Pets in Two Languages

    Directory of Open Access Journals (Sweden)

    Wahyu Febriyanto

    2017-02-01

    Full Text Available Introducing environment is important for children. Included in this environment is the life of living beings such as humans, animals, and plants. The role of parents is needed in introducing the living creatures. One of the living creatures that endeared children are animals, especially the pets. Therefore made educational game The Pets. With the game "The Pets" is expected to help parents to teach the children in learning about pets based on place of living and food. In this paper describes how to design and create introducing pet game based on the type of food and its habitat in two different languages . "The Pets" has the Android platform with a minimum API Level 14 is created using the game engine Construct 2. Using two dimensional model and image with interesting coloring for children, and using the application CorelDraw X4. From results of the survey, "The Pets" can provide new knowledge and can assist children in learning about pets based on place of living and food. Children who previously could not mention animals vocabulary in English, after playing "The Pets" can name them into English.

  16. 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

    Background The aim of this study was to develop and validate an automated method for extracting forward stroke volume (FSV) using indicator dilution theory directly from dynamic positron emission tomography (PET) studies for two different tracers and scanners. Methods 35 subjects underwent...... a dynamic 11 C-acetate PET scan on a Siemens Biograph TruePoint-64 PET/CT (scanner I). In addition, 10 subjects underwent both dynamic 15 O-water PET and 11 C-acetate PET scans on a GE Discovery-ST PET/CT (scanner II). The left ventricular (LV)-aortic time-activity curve (TAC) was extracted automatically...... from PET data using cluster analysis. The first-pass peak was isolated by automatic extrapolation of the downslope of the TAC. FSV was calculated as the injected dose divided by the product of heart rate and the area under the curve of the first-pass peak. Gold standard FSV was measured using phase...

  17. PET/CT: panacea, redundancy, or something in between?

    NARCIS (Netherlands)

    Vogel, W.V.; Oyen, W.J.G.; Barentsz, J.O.; Kaanders, J.H.A.M.; Corstens, F.H.M.

    2004-01-01

    In the past decade, the integration of anatomic imaging and functional imaging has emerged as a new and promising diagnostic tool. Developments in software provided methods to integrate various modalities, such as PET, CT, MRI, and MR spectroscopy. The introduction of combined PET/CT scanners has

  18. PET/MR synchronization by detection of switching gradients

    Energy Technology Data Exchange (ETDEWEB)

    Weissler, Bjoern [Department Molecular Imaging Systems, Philips Research Europe - Aachen, Pauwelsstrasse 17, D-52074 Aachen (Germany); Department of Physics of Molecular Imaging Systems, Institute of Experimental Molecular Imaging, RWTH Aachen University, Pauwelsstrasse 20, D-52074 Aachen (Germany); Institute of High Frequency Technology, RWTH Aachen University, Melatener Straße 25, D-52074 Aachen (Germany); Gebhardt, Pierre [Imaging Sciences & Biomedical Engineering, King’s College London, St Thomas Hospital, London, SE1 7EH (United Kingdom); Lerche, Christoph W [Department Molecular Imaging Systems, Philips Research Europe - Aachen, Pauwelsstrasse 17, D-52074 Aachen (Germany); Soultanidis, Georgios [Imaging Sciences & Biomedical Engineering, King’s College London, St Thomas Hospital, London, SE1 7EH (United Kingdom); Wehner, Jakob [Department of Physics of Molecular Imaging Systems, Institute of Experimental Molecular Imaging, RWTH Aachen University, Pauwelsstrasse 20, D-52074 Aachen (Germany); Heberling, Dirk [Institute of High Frequency Technology, RWTH Aachen University, Melatener Straße 25, D-52074 Aachen (Germany); Schulz, Volkmar [Department Molecular Imaging Systems, Philips Research Europe - Aachen, Pauwelsstrasse 17, D-52074 Aachen (Germany); Department of Physics of Molecular Imaging Systems, Institute of Experimental Molecular Imaging, RWTH Aachen University, Pauwelsstrasse 20, D-52074 Aachen (Germany)

    2014-07-29

    The full potential of simultaneous PET and MRI image acquisition, such as dynamic studies or motion compensation, can only be explored if the data of both modalities are temporally synchronized. These hybrid imaging systems are often realized as custom made PET inserts for commercially available MRI scanner. Unfortunately, the standard MRIs do not always offer easily programmable synchronization outputs, nor can they be modified.

  19. Evaluation of Small-Animal PET Outcome Measures to Detect Disease Modification Induced by BACE Inhibition in a Transgenic Mouse Model of Alzheimer Disease.

    Science.gov (United States)

    Deleye, Steven; Waldron, Ann-Marie; Verhaeghe, Jeroen; Bottelbergs, Astrid; Wyffels, Leonie; Van Broeck, Bianca; Langlois, Xavier; Schmidt, Mark; Stroobants, Sigrid; Staelens, Steven

    2017-12-01

    In this study, we investigated the effects of chronic administration of an inhibitor of the β-site amyloid precursor protein-cleaving enzyme 1 (BACE1) on Alzheimer-related pathology by multitracer PET imaging in transgenic APPPS1-21 (TG) mice. Methods: Wild-type (WT) and TG mice received vehicle or BACE inhibitor (60 mg/kg) starting at 7 wk of age. Outcome measures of brain metabolism, neuroinflammation, and amyloid-β pathology were obtained through small-animal PET imaging with 18 F-FDG, 18 F-peripheral benzodiazepine receptor ( 18 F-PBR), and 18 F-florbetapir ( 18 F-AV45), respectively. Baseline scans were acquired at 6-7 wk of age and follow-up scans at 4, 7, and 12 mo. 18 F-AV45 uptake was measured at 8 and 13 mo of age. After the final scans, histologic measures of amyloid-β (4G8), microglia (ionized calcium binding adaptor molecule 1), astrocytes (glial fibrillary acidic protein), and neuronal nuclei were performed. Results: TG mice demonstrated significant age-associated increases in 18 F-AV45 uptake. An effect of treatment was observed in the cortex ( P = 0.0014), hippocampus ( P = 0.0005), and thalamus ( P < 0.0001). Histology confirmed reduction of amyloid-β pathology in TG-BACE mice. Regardless of treatment, TG mice demonstrated significantly lower 18 F-FDG uptake than WT mice in the thalamus ( P = 0.0004) and hippocampus ( P = 0.0332). Neuronal nucleus staining was lower in both TG groups in the thalamus and cortex. 18 F-PBR111 detected a significant age-related increase in TG mice ( P < 0.0001) but did not detect the treatment-induced reduction in activated microglia as demonstrated by histology. Conclusion: Although 18 F-FDG, 18 F-PBR111, and 18 F-AV45 all detected pathologic alterations between TG and WT mice, only 18 F-AV45 could detect an effect of BACE inhibitor treatment. However, changes in WT binding of 18 F-AV45 undermine the specificity of this effect. © 2017 by the Society of Nuclear Medicine and Molecular Imaging.

  20. Experimental validation of gallium production and isotope-dependent positron range correction in PET

    Energy Technology Data Exchange (ETDEWEB)

    Fraile, L.M., E-mail: lmfraile@ucm.es [Grupo de Física Nuclear, Dpto. Física Atómica, Molecular y Nuclear, Universidad Complutense de Madrid (Spain); Herraiz, J.L.; Udías, J.M.; Cal-González, J.; Corzo, P.M.G.; España, S.; Herranz, E.; Pérez-Liva, M.; Picado, E.; Vicente, E. [Grupo de Física Nuclear, Dpto. Física Atómica, Molecular y Nuclear, Universidad Complutense de Madrid (Spain); Muñoz-Martín, A. [Centro de Microanálisis de Materiales, Universidad Autónoma de Madrid, E-28049 Madrid (Spain); Vaquero, J.J. [Departamento de Bioingeniería e Ingeniería Aeroespacial, Universidad Carlos III de Madrid (Spain)

    2016-04-01

    Positron range (PR) is one of the important factors that limit the spatial resolution of positron emission tomography (PET) preclinical images. Its blurring effect can be corrected to a large extent if the appropriate method is used during the image reconstruction. Nevertheless, this correction requires an accurate modelling of the PR for the particular radionuclide and materials in the sample under study. In this work we investigate PET imaging with {sup 68}Ga and {sup 66}Ga radioisotopes, which have a large PR and are being used in many preclinical and clinical PET studies. We produced a {sup 68}Ga and {sup 66}Ga phantom on a natural zinc target through (p,n) reactions using the 9-MeV proton beam delivered by the 5-MV CMAM tandetron accelerator. The phantom was imaged in an ARGUS small animal PET/CT scanner and reconstructed with a fully 3D iterative algorithm, with and without PR corrections. The reconstructed images at different time frames show significant improvement in spatial resolution when the appropriate PR is applied for each frame, by taking into account the relative amount of each isotope in the sample. With these results we validate our previously proposed PR correction method for isotopes with large PR. Additionally, we explore the feasibility of PET imaging with {sup 68}Ga and {sup 66}Ga radioisotopes in proton therapy.

  1. PET image reconstruction with rotationally symmetric polygonal pixel grid based highly compressible system matrix

    International Nuclear Information System (INIS)

    Yu Yunhan; Xia Yan; Liu Yaqiang; Wang Shi; Ma Tianyu; Chen Jing; Hong Baoyu

    2013-01-01

    To achieve a maximum compression of system matrix in positron emission tomography (PET) image reconstruction, we proposed a polygonal image pixel division strategy in accordance with rotationally symmetric PET geometry. Geometrical definition and indexing rule for polygonal pixels were established. Image conversion from polygonal pixel structure to conventional rectangular pixel structure was implemented using a conversion matrix. A set of test images were analytically defined in polygonal pixel structure, converted to conventional rectangular pixel based images, and correctly displayed which verified the correctness of the image definition, conversion description and conversion of polygonal pixel structure. A compressed system matrix for PET image recon was generated by tap model and tested by forward-projecting three different distributions of radioactive sources to the sinogram domain and comparing them with theoretical predictions. On a practical small animal PET scanner, a compress ratio of 12.6:1 of the system matrix size was achieved with the polygonal pixel structure, comparing with the conventional rectangular pixel based tap-mode one. OS-EM iterative image reconstruction algorithms with the polygonal and conventional Cartesian pixel grid were developed. A hot rod phantom was detected and reconstructed based on these two grids with reasonable time cost. Image resolution of reconstructed images was both 1.35 mm. We conclude that it is feasible to reconstruct and display images in a polygonal image pixel structure based on a compressed system matrix in PET image reconstruction. (authors)

  2. Experimental validation of gallium production and isotope-dependent positron range correction in PET

    Science.gov (United States)

    Fraile, L. M.; Herraiz, J. L.; Udías, J. M.; Cal-González, J.; Corzo, P. M. G.; España, S.; Herranz, E.; Pérez-Liva, M.; Picado, E.; Vicente, E.; Muñoz-Martín, A.; Vaquero, J. J.

    2016-04-01

    Positron range (PR) is one of the important factors that limit the spatial resolution of positron emission tomography (PET) preclinical images. Its blurring effect can be corrected to a large extent if the appropriate method is used during the image reconstruction. Nevertheless, this correction requires an accurate modelling of the PR for the particular radionuclide and materials in the sample under study. In this work we investigate PET imaging with 68Ga and 66Ga radioisotopes, which have a large PR and are being used in many preclinical and clinical PET studies. We produced a 68Ga and 66Ga phantom on a natural zinc target through (p,n) reactions using the 9-MeV proton beam delivered by the 5-MV CMAM tandetron accelerator. The phantom was imaged in an ARGUS small animal PET/CT scanner and reconstructed with a fully 3D iterative algorithm, with and without PR corrections. The reconstructed images at different time frames show significant improvement in spatial resolution when the appropriate PR is applied for each frame, by taking into account the relative amount of each isotope in the sample. With these results we validate our previously proposed PR correction method for isotopes with large PR. Additionally, we explore the feasibility of PET imaging with 68Ga and 66Ga radioisotopes in proton therapy.

  3. Pet food safety: the roles of government, manufacturers, and veterinarians.

    Science.gov (United States)

    Eirmann, Laura; Cowell, Christopher; Thompson, Larry

    2012-01-01

    Food safety is of concern for both human and companion animal health. Government agencies, pet food manufacturers, and veterinarians play crucial roles in ensuring the safety of pet food and safeguarding pets and their owners. Recent legislation will increase the governmental role in regulating pet food and will affect many manufacturers. Veterinarians continue to play a vital role by recognizing and reporting pet food safety issues and by educating clients on matters related to pet food safety.

  4. PET/MRI in the presence of metal implants: Completion of the attenuation map from PET emission data

    DEFF Research Database (Denmark)

    Fuin, Niccolo; Pedemonte, Stefano; Catalano, Onofrio A.

    2017-01-01

    We present a novel technique for accurate whole-body attenuation correction in the presence of metallic endoprosthesis, on integrated non-time-of-flight (non-TOF) PET/MRI scanners. The proposed implant PET-based attenuationmap completion (IPAC) method performs a joint reconstruction of radioactiv...

  5. Parametric Imaging and Test-Retest Variability of ¹¹C-(+)-PHNO Binding to D₂/D₃ Dopamine Receptors in Humans on the High-Resolution Research Tomograph PET Scanner.

    Science.gov (United States)

    Gallezot, Jean-Dominique; Zheng, Ming-Qiang; Lim, Keunpoong; Lin, Shu-fei; Labaree, David; Matuskey, David; Huang, Yiyun; Ding, Yu-Shin; Carson, Richard E; Malison, Robert T

    2014-06-01

    (11)C-(+)-4-propyl-9-hydroxynaphthoxazine ((11)C-(+)-PHNO) is an agonist radioligand for imaging dopamine D2 and D3 receptors in the human brain with PET. In this study we evaluated the reproducibility of (11)C-(+)-PHNO binding parameters using a within-day design and assessed parametric imaging methods. Repeated studies were performed in 8 subjects, with simultaneous measurement of the arterial input function and plasma free fraction. Two (11)C-(+)-PHNO scans for the same subject were separated by 5.4 ± 0.7 h. After compartment models were evaluated, (11)C-(+)-PHNO volumes of distribution (V(T)) and binding potentials relative to the concentration of tracer in plasma (BP(P)), nondisplaceable tracer in tissue (BP(ND)), and free tracer in tissue (BP(F)) were quantified using the multilinear analysis MA1 method, with the cerebellum as the reference region. Parametric images of BP(ND) were also computed using the simplified reference tissue model (SRTM) and SRTM2. The test-retest variability of (11)C-(+)-PHNO BP(ND) was 9% in D2-rich regions (caudate and putamen). Among D3-rich regions, variability was low in the pallidum (6%) but higher in substantia nigra (19%), thalamus (14%), and hypothalamus (21%). No significant mass carry-over effect was observed in D3-rich regions, although a trend in BP(ND) was present in the substantia nigra (-14% ± 15%). Because of the relatively fast kinetics, low-noise BP(ND) parametric images were obtained with both SRTM and SRTM2 without spatial smoothing. (11)C-(+)-PHNO can be used to compute low-noise parametric images in both D2- and D3-rich regions in humans. © 2014 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

  6. Effect of Animal Condition and Fluvoxamine on the Result of [18F]N 3 Fluoropropyl-2β carbomethoxy-3β (4-iodophenyl) Nortropane ([18F]FP-CIT) PET Study in Mice

    International Nuclear Information System (INIS)

    Shin, Kwang Ho; Lee Sang Ju; Oh, Seung Jun; Kim, Jae Seung; Park, Su A; Kim, Seog Young

    2012-01-01

    PET (positron emission tomography) is a noninvasive imaging technique, visualizing biological aspects in vivo. In animal models, the result of PET study can be affected more prominently than in humans by the animal conditions or drug pretreatment. We assessed the effects of anesthesia, body temperature, and pretreatment with selective serotonin reuptake inhibitor on the results of [ 18F ]N 3 fluoropropyl 2β carbomethoxy 3β (4-iodophenyl) nortropane ([ 18F ]FP CIT) PET in mice. [ 18F ]FP CIT PET of C57BL/6 mice was performed in three different conditions: (1) anesthesia (isoflurane) with active warming (38.deg.C) as a reference; (2) no anesthesia or warming; (3) anesthesia without warming at room temperature. Additional groups of mine pretreated with escalating doses of fluvoxamine (5, 20, 40, 80 mg/kg) were imaged in condition (1). The time activity curve and standardized uptake value of the striatum, cerebral cortex, and bone were compared among these conditions. In all conditions, radioactivities of the striatum and cortex tended to form a plateau after rapid uptake and washout, but that of bone tended to increase gradually. When anesthetized without any warming, all the mice developed hypothermia and showed reduced bone uptake compared to the reference condition. In conditions without anesthesia, striatal and cortical uptakes compared to the reference condition. In conditions without anesthesia, striatal and cortical uptakes were reduced, whereas the bone uptake showed no change. Pretreatment with fluvoxamine increased the striatal uptake and striatal specific to cortical non specific uptake ratio, whereas the bone uptake was reduced. Anesthesia, body temperature, and fluvoxamine affect the result of [ 18F ]FP CIT PET in mice by altering striatal and bone uptakes

  7. Effect of Animal Condition and Fluvoxamine on the Result of [{sup 18F}]N 3 Fluoropropyl-2{beta} carbomethoxy-3{beta} (4-iodophenyl) Nortropane ([{sup 18F}]FP-CIT) PET Study in Mice

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Kwang Ho; Lee Sang Ju; Oh, Seung Jun; Kim, Jae Seung [Asan Medical Center, Univ. of Ulsan College of Medicine, Seoul (Korea, Republic of); Park, Su A [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of); Kim, Seog Young [Univ. of Pittsburgh, Pittaburg (United States)

    2012-03-15

    PET (positron emission tomography) is a noninvasive imaging technique, visualizing biological aspects in vivo. In animal models, the result of PET study can be affected more prominently than in humans by the animal conditions or drug pretreatment. We assessed the effects of anesthesia, body temperature, and pretreatment with selective serotonin reuptake inhibitor on the results of [{sup 18F}]N 3 fluoropropyl 2{beta} carbomethoxy 3{beta} (4-iodophenyl) nortropane ([{sup 18F}]FP CIT) PET in mice. [{sup 18F}]FP CIT PET of C57BL/6 mice was performed in three different conditions: (1) anesthesia (isoflurane) with active warming (38.deg.C) as a reference; (2) no anesthesia or warming; (3) anesthesia without warming at room temperature. Additional groups of mine pretreated with escalating doses of fluvoxamine (5, 20, 40, 80 mg/kg) were imaged in condition (1). The time activity curve and standardized uptake value of the striatum, cerebral cortex, and bone were compared among these conditions. In all conditions, radioactivities of the striatum and cortex tended to form a plateau after rapid uptake and washout, but that of bone tended to increase gradually. When anesthetized without any warming, all the mice developed hypothermia and showed reduced bone uptake compared to the reference condition. In conditions without anesthesia, striatal and cortical uptakes compared to the reference condition. In conditions without anesthesia, striatal and cortical uptakes were reduced, whereas the bone uptake showed no change. Pretreatment with fluvoxamine increased the striatal uptake and striatal specific to cortical non specific uptake ratio, whereas the bone uptake was reduced. Anesthesia, body temperature, and fluvoxamine affect the result of [{sup 18F}]FP CIT PET in mice by altering striatal and bone uptakes.

  8. Small-Animal PET Imaging of Amyloid-Beta Plaques with [11C]PiB and Its Multi-Modal Validation in an APP/PS1 Mouse Model of Alzheimer's Disease

    Science.gov (United States)

    Manook, André; Yousefi, Behrooz H.; Willuweit, Antje; Platzer, Stefan; Reder, Sybille; Voss, Andreas; Huisman, Marc; Settles, Markus; Neff, Frauke; Velden, Joachim; Schoor, Michael; von der Kammer, Heinz; Wester, Hans-Jürgen; Schwaiger, Markus

    2012-01-01

    In vivo imaging and quantification of amyloid-β plaque (Aβ) burden in small-animal models of Alzheimer's disease (AD) is a valuable tool for translational research such as developing specific imaging markers and monitoring new therapy approaches. Methodological constraints such as image resolution of positron emission tomography (PET) and lack of suitable AD models have limited the feasibility of PET in mice. In this study, we evaluated a feasible protocol for PET imaging of Aβ in mouse brain with [11C]PiB and specific activities commonly used in human studies. In vivo mouse brain MRI for anatomical reference was acquired with a clinical 1.5 T system. A recently characterized APP/PS1 mouse was employed to measure Aβ at different disease stages in homozygous and hemizygous animals. We performed multi-modal cross-validations for the PET results with ex vivo and in vitro methodologies, including regional brain biodistribution, multi-label digital autoradiography, protein quantification with ELISA, fluorescence microscopy, semi-automated histological quantification and radioligand binding assays. Specific [11C]PiB uptake in individual brain regions with Aβ deposition was demonstrated and validated in all animals of the study cohort including homozygous AD animals as young as nine months. Corresponding to the extent of Aβ pathology, old homozygous AD animals (21 months) showed the highest uptake followed by old hemizygous (23 months) and young homozygous mice (9 months). In all AD age groups the cerebellum was shown to be suitable as an intracerebral reference region. PET results were cross-validated and consistent with all applied ex vivo and in vitro methodologies. The results confirm that the experimental setup for non-invasive [11C]PiB imaging of Aβ in the APP/PS1 mice provides a feasible, reproducible and robust protocol for small-animal Aβ imaging. It allows longitudinal imaging studies with follow-up periods of approximately one and a half years and

  9. Selecting Safe Pets (For Parents)

    Science.gov (United States)

    ... because you can buy a pet from the pet store doesn't mean it's safe for homes with kids. Animals that may not be child-safe include: reptiles (turtles, snakes, lizards, iguanas) rodents (hamsters, gerbils, guinea pigs, chinchillas, hedgehogs, prairie ...

  10. Competitive advantage of PET/MRI.

    Science.gov (United States)

    Jadvar, Hossein; Colletti, Patrick M

    2014-01-01

    Multimodality imaging has made great strides in the imaging evaluation of patients with a variety of diseases. Positron emission tomography/computed tomography (PET/CT) is now established as the imaging modality of choice in many clinical conditions, particularly in oncology. While the initial development of combined PET/magnetic resonance imaging (PET/MRI) was in the preclinical arena, hybrid PET/MR scanners are now available for clinical use. PET/MRI combines the unique features of MRI including excellent soft tissue contrast, diffusion-weighted imaging, dynamic contrast-enhanced imaging, fMRI and other specialized sequences as well as MR spectroscopy with the quantitative physiologic information that is provided by PET. Most evidence for the potential clinical utility of PET/MRI is based on studies performed with side-by-side comparison or software-fused MRI and PET images. Data on distinctive utility of hybrid PET/MRI are rapidly emerging. There are potential competitive advantages of PET/MRI over PET/CT. In general, PET/MRI may be preferred over PET/CT where the unique features of MRI provide more robust imaging evaluation in certain clinical settings. The exact role and potential utility of simultaneous data acquisition in specific research and clinical settings will need to be defined. It may be that simultaneous PET/MRI will be best suited for clinical situations that are disease-specific, organ-specific, related to diseases of the children or in those patients undergoing repeated imaging for whom cumulative radiation dose must be kept as low as reasonably achievable. PET/MRI also offers interesting opportunities for use of dual modality probes. Upon clear definition of clinical utility, other important and practical issues related to business operational model, clinical workflow and reimbursement will also be resolved. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  11. Pet therapy: dogs de-stress students.

    Science.gov (United States)

    Young, Judith S

    2012-01-01

    Research supports the efficacy of the human-animal bond and pet therapy in a variety of settings. At nursing students' request at one school, the author began offering pet therapy prior to examinations. Anecdotal evidence of a study with the author's Golden Retriever, Goldilocks, demonstrates that pet therapy can reduce test anxiety and improve nursing student performance.

  12. How does PET/MR work? Basic physics for physicians.

    Science.gov (United States)

    Delso, Gaspar; Ter Voert, Edwin; Veit-Haibach, Patrick

    2015-08-01

    The aim of this article is to provide Radiologists and Nuclear Medicine physicians the basic information required to understand how PET/MR scanners work, what are their limitations and how to evaluate their performance. It will cover the operational principles of standalone PET and MR imaging, as well as the technical challenges of creating a hybrid system and how they have been solved in the now commercially available scanners. Guidelines will be provided to interpret the main performance figures of hybrid PET/MR systems.

  13. PET image reconstruction: mean, variance, and optimal minimax criterion

    International Nuclear Information System (INIS)

    Liu, Huafeng; Guo, Min; Gao, Fei; Shi, Pengcheng; Xue, Liying; Nie, Jing

    2015-01-01

    Given the noise nature of positron emission tomography (PET) measurements, it is critical to know the image quality and reliability as well as expected radioactivity map (mean image) for both qualitative interpretation and quantitative analysis. While existing efforts have often been devoted to providing only the reconstructed mean image, we present a unified framework for joint estimation of the mean and corresponding variance of the radioactivity map based on an efficient optimal min–max criterion. The proposed framework formulates the PET image reconstruction problem to be a transformation from system uncertainties to estimation errors, where the minimax criterion is adopted to minimize the estimation errors with possibly maximized system uncertainties. The estimation errors, in the form of a covariance matrix, express the measurement uncertainties in a complete way. The framework is then optimized by ∞-norm optimization and solved with the corresponding H ∞ filter. Unlike conventional statistical reconstruction algorithms, that rely on the statistical modeling methods of the measurement data or noise, the proposed joint estimation stands from the point of view of signal energies and can handle from imperfect statistical assumptions to even no a priori statistical assumptions. The performance and accuracy of reconstructed mean and variance images are validated using Monte Carlo simulations. Experiments on phantom scans with a small animal PET scanner and real patient scans are also conducted for assessment of clinical potential. (paper)

  14. A High Resolution Monolithic Crystal, DOI, MR Compatible, PET Detector

    Energy Technology Data Exchange (ETDEWEB)

    Robert S Miyaoka

    2012-03-06

    The principle objective of this proposal is to develop a positron emission tomography (PET) detector with depth-of-interaction (DOI) positioning capability that will achieve state of the art spatial resolution and sensitivity performance for small animal PET imaging. When arranged in a ring or box detector geometry, the proposed detector module will support <1 mm3 image resolution and >15% absolute detection efficiency. The detector will also be compatible with operation in a MR scanner to support simultaneous multi-modality imaging. The detector design will utilize a thick, monolithic crystal scintillator readout by a two-dimensional array of silicon photomultiplier (SiPM) devices using a novel sensor on the entrance surface (SES) design. Our hypothesis is that our single-ended readout SES design will provide an effective DOI positioning performance equivalent to more expensive dual-ended readout techniques and at a significantly lower cost. Our monolithic crystal design will also lead to a significantly lower cost system. It is our goal to design a detector with state of the art performance but at a price point that is affordable so the technology can be disseminated to many laboratories. A second hypothesis is that using SiPM arrays, the detector will be able to operate in a MR scanner without any degradation in performance to support simultaneous PET/MR imaging. Having a co-registered MR image will assist in radiotracer localization and may also be used for partial volume corrections to improve radiotracer uptake quantitation. The far reaching goal of this research is to develop technology for medical research that will lead to improvements in human health care.

  15. Animal-specific positioning molds for registration of repeat imaging studies: comparative microPET imaging of F18-labeled fluoro-deoxyglucose and fluoro-misonidazole in rodent tumors

    International Nuclear Information System (INIS)

    Zanzonico, Pat; Campa, Jose; Polycarpe-Holman, Dolores; Forster, Gregor; Finn, Ronald; Larson, Steven; Humm, John; Ling, Clifton

    2006-01-01

    Introduction: Comparative imaging of multiple radiotracers in the same animal can be invaluable in elucidating and validating their respective mechanisms of localization. Comparative imaging of PET tracers, particularly in small animals, is problematic, however: such tracers must be administered and imaged separately because simultaneously imaged positron emitters cannot be separated based on energy discrimination. Objective: As part of our ongoing development of hypoxia imaging radiotracers, the intratumoral distributions of sequentially administered F18-fluoro-deoxyglucose (FDG) and the hypoxia tracer F18-fluoromisonidazole (FMiso) were compared in rats by registered microPET imaging with positioning of each animal in a custom-fabricated whole-body mold. Methods: Nude rats with a hindlimb R3327-AT anaplastic rat prostate tumor xenograft and a hindlimb FaDu human squamous cell carcinoma (each up to 20x20x30 mm in size) were studied. Rapid-Foam (Soule Medical, Lutz, FL) was used to fabricate animal-specific molds for immobilization and reproducible positioning. Each rat was injected via the tail vein with ∼33 MBq (900 μCi) of FDG and imaged in its mold at 1 h postinjection (pi) on the microPET. The next day, each rat was injected with ∼22 MBq (600 μCi) of FMiso and positioned and imaged in its mold at ∼2 h pi. Custom-manufactured germanium-68 rods (10 μCi each, 1x10 mm) were reproducibly positioned in the mold as fiduciary markers. Results: The registered microPET images unambiguously demonstrated grossly similar though not identical distributions of FDG and FMiso in the tumors - a high-activity rim surrounding a lower-activity core. There were subtle but possibly significant differences in the intratumoral distributions of FDG and FMiso, however. These may not have been discerned without careful image registration. Conclusion: Animal-specific molds are inexpensive and straightforward to fabricate and use for registration (±1 to 2 mm) of sequential PET

  16. Are Pets in the Bedroom a Problem?

    Science.gov (United States)

    Krahn, Lois E; Tovar, M Diane; Miller, Bernie

    2015-12-01

    The presence of pets in the bedroom can alter the sleep environment in ways that could affect sleep. Data were collected by questionnaire and interview from 150 consecutive patients seen at the Center for Sleep Medicine, Mayo Clinic in Arizona. Seventy-four people (49%) reported having pets, with 31 (41% of pet owners) having multiple pets. More than half of pet owners (56%) allowed their pets to sleep in the bedroom. Fifteen pet owners (20%) described their pets as disruptive, whereas 31 (41%) perceived their pets as unobtrusive or even beneficial to sleep. Health care professionals working with patients with sleep concerns should inquire about the presence of companion animals in the sleep environment to help them find solutions and optimize their sleep. Copyright © 2015 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.

  17. The ECAT ART Scanner for Positron Emission Tomography. 1. Improvements in Performance Characteristics.

    Science.gov (United States)

    Townsend, David W.; Beyer, Thomas; Jerin, Jeff; Watson, Charles C.; Young, John; Nutt, Ronald

    1999-01-01

    The widespread use of positron emission tomography (PET) has been to some extent limited by the cost and complexity of PET instrumentation. Recognition of the wider applicability of clinical PET imaging is reflected in the ECAT ART design, a low cost PET scanner targeted for clinical applications, particularly in oncology. The ART comprises two asymmetrically opposed arrays of BGO block detectors. Each array consists of 88 (transaxial) by 24 (axial) crystals, and the arrays rotate continuously at 30 rpm to acquire a full 3D projection data set. Sensitivity and count rate limitations are key performance parameters for any imaging device. This paper reports on improved performance characteristics of the ART, achieved by operating the scanner with a decreased block integration time, reduced coincidence time window, and collimated singles transmission sources. Compared to the standard ART configuration, these modifications result in both improved count rate performance and higher quality transmission scans.

  18. Disaster Preparedness for Your Pet

    Science.gov (United States)

    ... Keep a leash and/or carrier nearby the exit. Ensure proper equipment for pets to ride in ... also carry a variety of diseases (Lyme disease, West Nile virus) harmful to both humans and animals. ...

  19. PET/CT or PET/MR for clinical molecular imaging in next decade

    International Nuclear Information System (INIS)

    Bal, C.S.

    2012-01-01

    In the era of molecular imaging, the true clinical benefits to patients started with use of hybrid equipment's (hardware integration of structural and functional imaging) since 2001, in the form of PET-CT. In a decade time more than 5000 PET-CT scanners have been installed all over the world including more than 50 in India. Application of 18 FDG PET-CT in oncology has revolutionized the patient management from staging/restaging of cancer, monitoring chemoradiotherapy and even predicting the outcome of multimodality interventions. The flip-side of the generous repeated use of PET-CT in all age groups has raised concern not only among professionals but also among patients as World Health Organization (WHO) has accepted radiation as a definite carcinogen. The numbers are very clear indication for the concern: out of 25 mSv delivered in a standard 18FDG PET-CT whole body scanning 18 mSv is due to CT and 7 mSv is due to 10 mCi 18FDG. Due to huge public outcry, all vendors have started building new scanners which delivered considerably lesser radiation dose to patient without compromising the brilliant image quality of PET-CT. Next logical approach is to replace CT with MR which is based-on non-ionizing radiation principles. The proof-of-principle equipment is PET-MR scanner. There are several technological challenges to built such machine and at the same time to keep the cost within affordable limit. The prototypes are being tested in industry-academia collaboration centres and the initial research articles are very promising. Integrating high resolution PET with 3 Tesla MR in a single machine is truly technological marvel. The significant benefits of PET-MR would be the inherent superior soft-tissue contrast, no radiation from MR (minimal radiation from 18FDG) and simultaneous cross evaluation of multiple imaging biomarker in the form of fMRI, DWI, PWI, tractography and spectroscopy, in addition to functional PET imaging. The true molecular imaging is born. As all good

  20. PET and paediatrics; La tomographie par emission de positons (ou PET scan) en pediatrie

    Energy Technology Data Exchange (ETDEWEB)

    Boddaert, N. [Necker Enfants Malades, AP-HP, Serv Radiol Pediat, Paris (France); Ribeiro, M.J. [CEA, DSV, I2BM, Serv Hosp Frederic Joliot, F-91406 Orsay (France)

    2008-07-01

    Positon emission tomography (PET scan) is a functional imagery technique.As in scintigraphy, a radioactive tracer is administrated to the patient and its distribution into the organism is detected by a tomograph or a PET scanner. The nuclear medicine techniques which use radioactive tracers allow to obtain an imagery of the regional metabolism of glucose, blood flow or of different neurotransmitters. The PET-TDM (tomodensitometry) is an hybrid imagery system which associates a PET to a multi-bars scanner (4 to 64 bars). The use of hybrid imagery systems allows an anatomic register of the metabolic anomalies or others, as well as the adjustment of the attenuation of the emitted particles. (O.M.)

  1. Beam profile assessment in spectral CT scanners.

    Science.gov (United States)

    Anjomrouz, Marzieh; Shamshad, Muhammad; Panta, Raj K; Broeke, Lieza Vanden; Schleich, Nanette; Atharifard, Ali; Aamir, Raja; Bheesette, Srinidhi; Walsh, Michael F; Goulter, Brian P; Bell, Stephen T; Bateman, Christopher J; Butler, Anthony P H; Butler, Philip H

    2018-03-01

    In this paper, we present a method that uses a combination of experimental and modeled data to assess properties of x-ray beam measured using a small-animal spectral scanner. The spatial properties of the beam profile are characterized by beam profile shape, the angular offset along the rotational axis, and the photon count difference between experimental and modeled data at the central beam axis. Temporal stability of the beam profile is assessed by measuring intra- and interscan count variations. The beam profile assessment method was evaluated on several spectral CT scanners equipped with Medipix3RX-based detectors. On a well-calibrated spectral CT scanner, we measured an integral count error of 0.5%, intrascan count variation of 0.1%, and an interscan count variation of less than 1%. The angular offset of the beam center ranged from 0.8° to 1.6° for the studied spectral CT scanners. We also demonstrate the capability of this method to identify poor performance of the system through analyzing the deviation of the experimental beam profile from the model. This technique can, therefore, aid in monitoring the system performance to obtain a robust spectral CT; providing the reliable quantitative images. Furthermore, the accurate offset parameters of a spectral scanner provided by this method allow us to incorporate a more realistic form of the photon distribution in the polychromatic-based image reconstruction models. Both improvements of the reliability of the system and accuracy of the volume reconstruction result in a better discrimination and quantification of the imaged materials. © 2018 MARS Bioimaging Ltd. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine.

  2. Clinical Evaluation of PET Image Quality as a Function of Acquisition Time in a New TOF-PET/MRI Compared to TOF-PET/CT--Initial Results.

    Science.gov (United States)

    Zeimpekis, Konstantinos G; Barbosa, Felipe; Hüllner, Martin; ter Voert, Edwin; Davison, Helen; Veit-Haibach, Patrick; Delso, Gaspar

    2015-10-01

    The purpose of this study was to compare only the performance of the PET component between a TOF-PET/CT (henceforth noted as PET/CT) scanner and an integrated TOF-PET/MRI (henceforth noted as PET/MRI) scanner concerning image quality parameters and quantification in terms of standardized uptake value (SUV) as a function of acquisition time (a surrogate of dose). The CT and MR image quality were not assessed, and that is beyond the scope of this study. Five brain and five whole-body patients were included in the study. The PET/CT scan was used as a reference and the PET/MRI acquisition time was consecutively adjusted, taking into account the decay between the scans in order to expose both systems to the same amount of the emitted signal. The acquisition times were then retrospectively reduced to assess the performance of the PET/MRI for lower count rates. Image quality, image sharpness, artifacts, and noise were evaluated. SUV measurements were taken in the liver and in the white matter to compare quantification. Quantitative evaluation showed strong correlation between PET/CT and PET/MRI brain SUVs. Liver correlation was good, however, with lower uptake estimation in PET/MRI, partially justified by bio-redistribution. The clinical evaluation showed that PET/MRI offers higher image quality and sharpness with lower levels of noise and artifacts compared to PET/CT with reduced acquisition times for whole-body scans while for brain scans there is no significant difference. The TOF-PET/MRI showed higher image quality compared to TOF-PET/CT as tested with reduced imaging times. However, this result accounts mainly for body imaging, while no significant differences were found in brain imaging.

  3. Molecular Imaging in Breast Cancer: From Whole-Body PET/CT to Dedicated Breast PET

    Directory of Open Access Journals (Sweden)

    B. B. Koolen

    2012-01-01

    Full Text Available Positron emission tomography (PET, with or without integrated computed tomography (CT, using 18F-fluorodeoxyglucose (FDG is based on the principle of elevated glucose metabolism in malignant tumors, and its use in breast cancer patients is frequently being investigated. It has been shown useful for classification, staging, and response monitoring, both in primary and recurrent disease. However, because of the partial volume effect and limited resolution of most whole-body PET scanners, sensitivity for the visualization of small tumors is generally low. To improve the detection and quantification of primary breast tumors with FDG PET, several dedicated breast PET devices have been developed. In this nonsystematic review, we shortly summarize the value of whole-body PET/CT in breast cancer and provide an overview of currently available dedicated breast PETs.

  4. Pet Ownership and Evacuation Prior to Hurricane Irene

    Directory of Open Access Journals (Sweden)

    Nick Rohrbaugh

    2012-09-01

    Full Text Available Pet ownership has historically been one of the biggest risk factors for evacuation failure prior to natural disasters. The forced abandonment of pets during Hurricane Katrina in 2005 made national headlines and led to the passage of the Pet Evacuation and Transportation Standards Act (PETS, 2006 which mandated local authorities to plan for companion animal evacuation. Hurricane Irene hit the East Coast of the United States in 2011, providing an excellent opportunity to examine the impact of the PETS legislation on frequency and ease of evacuation among pet owners and non-pet owners. Ninety pet owners and 27 non-pet owners who lived in mandatory evacuation zones completed questionnaires assessing their experiences during the hurricane and symptoms of depression, PTSD, dissociative experiences, and acute stress. Pet ownership was not found to be a statistical risk factor for evacuation failure. However, many pet owners who failed to evacuate continue to cite pet related reasons.

  5. Pet Ownership and Evacuation Prior to Hurricane Irene.

    Science.gov (United States)

    Hunt, Melissa G; Bogue, Kelsey; Rohrbaugh, Nick

    2012-09-28

    Pet ownership has historically been one of the biggest risk factors for evacuation failure prior to natural disasters. The forced abandonment of pets during Hurricane Katrina in 2005 made national headlines and led to the passage of the Pet Evacuation and Transportation Standards Act (PETS, 2006) which mandated local authorities to plan for companion animal evacuation. Hurricane Irene hit the East Coast of the United States in 2011, providing an excellent opportunity to examine the impact of the PETS legislation on frequency and ease of evacuation among pet owners and non-pet owners. Ninety pet owners and 27 non-pet owners who lived in mandatory evacuation zones completed questionnaires assessing their experiences during the hurricane and symptoms of depression, PTSD, dissociative experiences, and acute stress. Pet ownership was not found to be a statistical risk factor for evacuation failure. However, many pet owners who failed to evacuate continue to cite pet related reasons.

  6. Automatic extraction of forward stroke volume using dynamic PET/CT

    DEFF Research Database (Denmark)

    Harms, Hans; Tolbod, Lars Poulsen; Hansson, Nils Henrik

    subjects underwent a dynamic 6 min 15O-water PET scan followed by a 27 min 11C-acetate PET scan on a GE Discovery ST PET/CT scanner (scanner II). The LV-aortic time-activity curve (TAC) was extracted automatically from dynamic PET data using cluster analysis. The first-pass peak was isolated by automatic......Background: Dynamic PET can be used to extract forward stroke volume (FSV) by the indicator dilution principle. The technique employed can be automated and is in theory independent on the tracer used and may therefore be added to any dynamic cardiac PET protocol. The aim of this study...... was to validate automated methods for extracting FSV directly from dynamic PET studies for two different tracers and to examine potential scanner hardware bias. Methods: 21 subjects underwent a dynamic 27 min 11C-acetate PET scan on a Siemens Biograph TruePoint 64 PET/CT scanner (scanner I). In addition, 8...

  7. I Love Petting Zoos!

    Centers for Disease Control (CDC) Podcasts

    2010-03-23

    This Kidtastics podcast helps children learn about how to stay safe and healthy when visiting petting zoos and other animal exhibits.  Created: 3/23/2010 by Centers for Disease Control and Prevention (CDC).   Date Released: 3/23/2010.

  8. Development of PET/MRI with insertable PET for simultaneous PET and MR imaging of human brain

    International Nuclear Information System (INIS)

    Jung, Jin Ho; Choi, Yong; Jung, Jiwoong; Kim, Sangsu; Lim, Hyun Keong; Im, Ki Chun; Oh, Chang Hyun; Park, Hyun-wook; Kim, Kyung Min; Kim, Jong Guk

    2015-01-01

    Purpose: The purpose of this study was to develop a dual-modality positron emission tomography (PET)/magnetic resonance imaging (MRI) with insertable PET for simultaneous PET and MR imaging of the human brain. Methods: The PET detector block was composed of a 4 × 4 matrix of detector modules, each consisting of a 4 × 4 array LYSO coupled to a 4 × 4 Geiger-mode avalanche photodiode (GAPD) array. The PET insert consisted of 18 detector blocks, circularly mounted on a custom-made plastic base to form a ring with an inner diameter of 390 mm and axial length of 60 mm. The PET gantry was shielded with gold-plated conductive fabric tapes with a thickness of 0.1 mm. The charge signals of PET detector transferred via 4 m long flat cables were fed into the position decoder circuit. The flat cables were shielded with a mesh-type aluminum sheet with a thickness of 0.24 mm. The position decoder circuit and field programmable gate array-embedded DAQ modules were enclosed in an aluminum box with a thickness of 10 mm and located at the rear of the MR bore inside the MRI room. A 3-T human MRI system with a Larmor frequency of 123.7 MHz and inner bore diameter of 60 cm was used as the PET/MRI hybrid system. A custom-made radio frequency (RF) coil with an inner diameter of 25 cm was fabricated. The PET was positioned between gradient and the RF coils. PET performance was measured outside and inside the MRI scanner using echo planar imaging, spin echo, turbo spin echo, and gradient echo sequences. MRI performance was also evaluated with and without the PET insert. The stability of the newly developed PET insert was evaluated and simultaneous PET and MR images of a brain phantom were acquired. Results: No significant degradation of the PET performance caused by MR was observed when the PET was operated using various MR imaging sequences. The signal-to-noise ratio of MR images was slightly degraded due to the PET insert installed inside the MR bore while the homogeneity was

  9. Voxel based statistical analysis method for microPET studies to assess the cerebral glucose metabolism in cat deafness model: comparison to ROI based method

    International Nuclear Information System (INIS)

    Kim, Jin Su; Lee, Jae Sung; Park, Min Hyun; Lee, Jong Jin; Kang, Hye Jin; Lee, Hyo Jeong; Oh, Seung Ha; Kim, Chong Sun; Jung, June Key; Lee, Myung Chul; Lee, Dong Soo; Lim, Sang Moo

    2005-01-01

    Imaging research on the brain of sensory-deprived cats using small animal PET scanner has gained interest since the abundant information about the sensory system of ths animal is available and close examination of the brain is possible due to larger size of its brain than mouse or rat. In this study, we have established the procedures for 3D voxel-based statistical analysis (SPM) of FDG PET image of cat brain, and confirmed using ROI based-method. FDG PET scans of 4 normal and 4 deaf cats were acquired for 30 minutes using microPET R4 scanner. Only the brain cortices were extracted using a masking and threshold method to facilitate spatial normalization. After spatial normalization and smoothing, 3D voxel-wise and ROI based t-test were performed to identify the regions with significant different FDG uptake between the normal and deaf cats. In ROI analysis, 26 ROIs were drawn on both hemispheres, and regional mean pixel value in each ROI was normalized to the global mean of the brain. Cat brains were spatially normalized well onto the target brain due to the removal of background activity. When cerebral glucose metabolism of deaf cats were compared to the normal controls after removing the effects of the global count, the glucose metabolism in the auditory cortex, head of caudate nucleus, and thalamus in both hemispheres of the deaf cats was significantly lower than that of the controls (P<0.01). No area showed a significantly increased metabolism in the deaf cats even in higher significance level (P<0.05). ROI analysis also showed significant reduction of glucose metabolism in the same region. This study established and confirmed a method for voxel-based analysis of animal PET data of cat brain, which showed high localization accuracy and specificity and was useful for examining the cerebral glucose metabolism in a cat cortical deafness model

  10. Voxel based statistical analysis method for microPET studies to assess the cerebral glucose metabolism in cat deafness model: comparison to ROI based method

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Su; Lee, Jae Sung; Park, Min Hyun; Lee, Jong Jin; Kang, Hye Jin; Lee, Hyo Jeong; Oh, Seung Ha; Kim, Chong Sun; Jung, June Key; Lee, Myung Chul; Lee, Dong Soo [Seoul National University College of Medicine, Seoul (Korea, Republic of); Lim, Sang Moo [KIRAMS, Seoul (Korea, Republic of)

    2005-07-01

    Imaging research on the brain of sensory-deprived cats using small animal PET scanner has gained interest since the abundant information about the sensory system of ths animal is available and close examination of the brain is possible due to larger size of its brain than mouse or rat. In this study, we have established the procedures for 3D voxel-based statistical analysis (SPM) of FDG PET image of cat brain, and confirmed using ROI based-method. FDG PET scans of 4 normal and 4 deaf cats were acquired for 30 minutes using microPET R4 scanner. Only the brain cortices were extracted using a masking and threshold method to facilitate spatial normalization. After spatial normalization and smoothing, 3D voxel-wise and ROI based t-test were performed to identify the regions with significant different FDG uptake between the normal and deaf cats. In ROI analysis, 26 ROIs were drawn on both hemispheres, and regional mean pixel value in each ROI was normalized to the global mean of the brain. Cat brains were spatially normalized well onto the target brain due to the removal of background activity. When cerebral glucose metabolism of deaf cats were compared to the normal controls after removing the effects of the global count, the glucose metabolism in the auditory cortex, head of caudate nucleus, and thalamus in both hemispheres of the deaf cats was significantly lower than that of the controls (P<0.01). No area showed a significantly increased metabolism in the deaf cats even in higher significance level (P<0.05). ROI analysis also showed significant reduction of glucose metabolism in the same region. This study established and confirmed a method for voxel-based analysis of animal PET data of cat brain, which showed high localization accuracy and specificity and was useful for examining the cerebral glucose metabolism in a cat cortical deafness model.

  11. Early Detection of Tumor Response by FLT/MicroPET Imaging in a C26 Murine Colon Carcinoma Solid Tumor Animal Model

    Directory of Open Access Journals (Sweden)

    Wan-Chi Lee

    2011-01-01

    Full Text Available Fluorine-18 fluorodeoxyglucose (18F-FDG positron emission tomography (PET imaging demonstrated the change of glucose consumption of tumor cells, but problems with specificity and difficulties in early detection of tumor response to chemotherapy have led to the development of new PET tracers. Fluorine-18-fluorothymidine (18F-FLT images cellular proliferation by entering the salvage pathway of DNA synthesis. In this study, we evaluate the early response of colon carcinoma to the chemotherapeutic drug, lipo-Dox, in C26 murine colorectal carcinoma-bearing mice by 18F-FDG and 18F-FLT. The male BALB/c mice were bilaterally inoculated with 1×105 and 1×106 C26 tumor cells per flank. Mice were intravenously treated with 10 mg/kg lipo-Dox at day 8 after 18F-FDG and 18F-FLT imaging. The biodistribution of 18F-FDG and 18F-FLT were followed by the microPET imaging at day 9. For the quantitative measurement of microPET imaging at day 9, 18F-FLT was superior to 18F-FDG for early detection of tumor response to Lipo-DOX at various tumor sizes (<0.05. The data of biodistribution showed similar results with those from the quantification of SUV (standard uptake value by microPET imaging. The study indicates that 18F-FLT/microPET is a useful imaging modality for early detection of chemotherapy in the colorectal mouse model.

  12. 7 CFR 501.10 - Pets.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 6 2010-01-01 2010-01-01 false Pets. 501.10 Section 501.10 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL RESEARCH SERVICE, DEPARTMENT OF AGRICULTURE CONDUCT ON U.S. MEAT ANIMAL RESEARCH CENTER, CLAY CENTER, NEBRASKA § 501.10 Pets. Animals shall be brought...

  13. Performance evaluation of SiPM photodetectors for PET imaging in the presence of magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Espana, S., E-mail: samuel@nuclear.fis.ucm.e [Grupo de Fisica Nuclear, Dpto. Fisica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid (Spain); Fraile, L.M.; Herraiz, J.L.; Udias, J.M. [Grupo de Fisica Nuclear, Dpto. Fisica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid (Spain); Desco, M.; Vaquero, J.J. [Unidad de Medicina y Cirugia Experimental, Hospital General Universitario Gregorio Maranon, Madrid (Spain)

    2010-02-01

    The multi-pixel photon counter (MPPC) or silicon photomultiplier (SiPM), recently introduced as a solid-state photodetector, consists of an array of Geiger-mode photodiodes (microcells). It is a promising device for PET due to its potential for high photon detection efficiency (PDE) and its foreseeable immunity to magnetic fields. It is also easy to use with simple read-outs, has a high gain and a small size. In this work we evaluate the in field performance of three 1x1 mm{sup 2} (with 100, 400 and 1600 microcells, respectively) and one 6x6 mm{sup 2} (arranged as a 2x2 array) Hamamatsu MPPCs for their use in PET imaging. We examine the dependence of the energy resolution and the gain of these devices on the temperature and reverse bias voltage, when coupled to LYSO scintillator crystals under conditions that one would find in a PET system. We find that the 400 and 1600 microcells models and the 2x2 array are suitable for small-size crystals, like those employed in high resolution small animal scanners. We have confirmed the good performance of these devices up to magnetic fields of 7 T as well as their suitability for performing PET acquisitions in the presence of fast switching gradients and high duty radiofrequency MRI sequences.

  14. 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.

  15. The cobalt-60 container scanner

    International Nuclear Information System (INIS)

    Jigang, A.; Liye, Z.; Yisi, L.; Haifeng, W.; Zhifang, W.; Liqiang, W.; Yuanshi, Z.; Xincheng, X.; Furong, L.; Baozeng, G.; Chunfa, S.

    1997-01-01

    The Institute of Nuclear Energy Technology (INET) has successfully designed and constructed a container (cargo) scanner, which uses cobalt-60 of 100-300 Ci as radiation source. The following performances of the Cobalt-60 container scanner have been achieved at INET: a) IQI (Image Quality Indicator) - 2.5% behind 100 mm of steel; b) CI (Contrast Indicator) - 0.7% behind 100 mm of steel; c) SP (Steel Penetration) - 240 mm of steel; d) Maximum Dose per Scanning - 0.02mGy; e) Throughput - twenty 40-foot containers per hour. These performances are equal or similar to those of the accelerator scanners. Besides these nice enough inspection properties, the Cobalt-60 scanner possesses many other special features which are better than accelerator scanners: a) cheap price - it will be only or two tenths of the accelerator scanner's; b) low radiation intensity - the radiation protection problem is much easier to solve and a lot of money can be saved on the radiation shielding building; c) much smaller area for installation and operation; d) simple operation and convenient maintenance; e) high reliability and stability. The Cobalt-60 container (or cargo) scanner is satisfied for boundary customs, seaports, airports and railway stations etc. Because of the nice special features said above, it is more suitable to be applied widely. Its high properties and low price will make it have much better application prospects

  16. Usefulness of automatic quantification of immunochemical staining on whole tumor sections for correlation with oncological small animal PET studies: an example with cell proliferation, glucose transporter 1 and FDG.

    Science.gov (United States)

    Aide, Nicolas; Labiche, Alexandre; Herlin, Paulette; Paciencia, Maria; Poulain, Laurent; Dutoit, Soizic; Montravers, Françoise; Gauduchon, Pascal; Chasle, Jacques

    2008-09-01

    To highlight the use of automatic quantification of immunochemical staining on digitized images of whole tumor sections in preclinical positron emission tomography (PET) studies. Xenografted human testicular tumors (36) were imaged with 2-deoxy-2[F-18]fluoro-D: -glucose (FDG) small animal PET (SA-PET). Tumor cell proliferation and glucose transportation were assessed with cyclin A and Glut-1 immunostaining. Tumor slides were digitized and processed with PixCyt software enabling whole slide quantification, then compared with junior and senior pathologist manual scoring. Manual and automatic quantification results were correlated to FDG uptake. For cyclin A, inter- and intra-observer agreement for manual scoring was 0.52 and 0.72 and concordance between senior pathologist and automatic quantification was 0.84. Correlations between Tumor/Background ratio and tumor cell proliferation assessed by automatic quantification, junior and senior pathologists were 0.75, 0.55, and 0.61, respectively. Correlation between Tumor/Background ratio and Glut-1 assessed by automatic quantification was 0.74. Automatic quantification of immunostaining is a valuable tool to overcome inter- and intra-observer variability for correlation of cell proliferation or other markers with tumor tracer uptake.

  17. Radiographic scanner apparatus

    International Nuclear Information System (INIS)

    Wake, R.H.

    1980-01-01

    The preferred embodiment of this invention includes a hardware system, or processing means, which operates faster than software. Moreover the computer needed is less expensive and smaller. Radiographic scanner apparatus is described for measuring the intensity of radiation after passage through a planar region and for reconstructing a representation of the attenuation of radiation by the medium. There is a source which can be rotated, and detectors, the output from which forms a data line. The detectors are disposed opposite the planar region from the source to produce a succession of data lines corresponding to the succession of angular orientations of the source. There is a convolver means for convolving each of these data lines, with a filter function, and a means of processing the convolved data lines to create the representation of the radiation attenuation in the planar region. There is also apparatus to generate a succession of data lines indicating radiation attenuation along a determinable path with convolver means. (U.K.)

  18. 3D Surface Realignment Tracking for Medical Imaging: A Phantom Study with PET Motion Correction

    DEFF Research Database (Denmark)

    Olesen, Oline Vinter; Paulsen, Rasmus Reinhold; Jensen, Rasmus Ramsbøl

    2011-01-01

    on a plastic mannequin head equipped with two positron emitting line sources. Two experiments were performed. The rst simulates rapid and short head movements, while the second simulates slow and contin- uous movements. In both cases, the system was able to produce PET scans with focus the PET reconstructions......We present a complete system for motion correction in high resolution brain positron emission tomography (PET) imaging. It is based on a compact structured light scanner mounted above the patient tunnel of the Siemens High Resolution Research Tomograph PET brain scanner. The structured light system...... of recon- structed PET frames. To align the structured light system with the PET coordinate system a novel registration algorithm based on the PET trans- mission scan and an initial surface has been developed. The performance of the complete setup has been evaluated using a custom made phantom based...

  19. Head and neck imaging with PET and PET/CT: artefacts from dental metallic implants

    International Nuclear Information System (INIS)

    Goerres, Gerhard W.; Hany, Thomas F.; Kamel, Ehab; Schulthess von, Gustav K.; Buck, Alfred

    2002-01-01

    Germanium-68 based attenuation correction (PET Ge68 ) is performed in positron emission tomography (PET) imaging for quantitative measurements. With the recent introduction of combined in-line PET/CT scanners, CT data can be used for attenuation correction. Since dental implants can cause artefacts in CT images, CT-based attenuation correction (PET CT ) may induce artefacts in PET images. The purpose of this study was to evaluate the influence of dental metallic artwork on the quality of PET images by comparing non-corrected images and images attenuation corrected by PET Ge68 and PET CT . Imaging was performed on a novel in-line PET/CT system using a 40-mAs scan for PET CT in 41 consecutive patients with high suspicion of malignant or inflammatory disease. In 17 patients, additional PET Ge68 images were acquired in the same imaging session. Visual analysis of fluorine-18 fluorodeoxyglucose (FDG) distribution in several regions of the head and neck was scored on a 4-point scale in comparison with normal grey matter of the brain in the corresponding PET images. In addition, artefacts adjacent to dental metallic artwork were evaluated. A significant difference in image quality scoring was found only for the lips and the tip of the nose, which appeared darker on non-corrected than on corrected PET images. In 33 patients, artefacts were seen on CT, and in 28 of these patients, artefacts were also seen on PET imaging. In eight patients without implants, artefacts were seen neither on CT nor on PET images. Direct comparison of PET Ge68 and PET CT images showed a different appearance of artefacts in 3 of 17 patients. Malignant lesions were equally well visible using both transmission correction methods. Dental implants, non-removable bridgework etc. can cause artefacts in attenuation-corrected images using either a conventional 68 Ge transmission source or the CT scan obtained with a combined PET/CT camera. We recommend that the non-attenuation-corrected PET images also be

  20. Evaluation of ambient radiation levels in positron emission tomography/computed tomography in microPET/CT laboratory; Avaliacao dos niveis de radiacao ambiental no laboratorio de tomografia por emissao de positrons acoplada a tomografia computadorizada, microPET/CT

    Energy Technology Data Exchange (ETDEWEB)

    Sarmento, Daniele Martins

    2016-11-01

    Micro PET/CT scanner is an essential tool generally used for small animal molecular imaging. Fluorine-18-labeled fluorodeoxyglucose is the most widely used radioisotope in this technique. The present study aimed to evaluate the radiation levels in a micro PET/CT research laboratory of the Radiopharmacy Center at IPEN-CNEN / SP, in order to accomplish both national standards and international recommendations. The radioprotection team has classified the laboratory as supervised area; even this laboratory does not require the adoption of specific measures for protection and safety, should be done regular re-evaluation of the conditions of occupational exposures. Workplace monitoring and individual control assessment were carried out to ensure the radiological protection of all workers directly involved in handling the scanner. Initially, there was conducted a radiometric survey, as well as measurements of the external radiation level in the workplace and its surroundings. To achieve this goal, there were placed nine thermoluminescent dosimeters of CaSO{sub 4}:Dy in preselected locations. Monthly evaluations of the occupationally exposed individuals were carried out through the use of TL dosimeters, ported in the workers' chest. Moreover, whole body measurements were performed every six months. The study period was about two-years which started in April 2014. All tests to evaluate micro PET/CT performance were based on the standard protocol of the equipment in accordance with the standard developed by the Animal PET Standard Task Force. Present study's results demonstrated that the ambient radiation levels (ambient and effective estimated radiation dose), as well as the effective shielding equipment are both adequate. This study emphasizes that it is essential to strictly follow the principles of radioprotection in workplace, whenever researches involve radioactive unsealed sources. (author)

  1. 9 CFR 130.10 - User fees for pet birds.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false User fees for pet birds. 130.10... AGRICULTURE USER FEES USER FEES § 130.10 User fees for pet birds. (a) User fees for pet birds of U.S. origin returning to the United States, except pet birds of U.S. origin returning from Canada, are as follows...

  2. Simultaneous PET/MRI with 13C magnetic resonance spectroscopic imaging (hyperPET): phantom-based evaluation of PET quantification