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Sample records for animal spect system

  1. Compact CT/SPECT Small-Animal Imaging System

    PubMed Central

    Kastis, George A.; Furenlid, Lars R.; Wilson, Donald W.; Peterson, Todd E.; Barber, H. Bradford; Barrett, Harrison H.

    2015-01-01

    We have developed a dual-modality CT/SPECT imaging system for small-animal imaging applications. The X-ray system comprises a commercially available micro-focus X-ray tube and a CCD-based X-ray camera. X-ray transmission measurements are performed based on cone-beam geometry. Individual projections are acquired by rotating the animal about a vertical axis in front of the CCD detector. A high-resolution CT image is obtained after reconstruction using an ordered subsets-expectation maximization (OS-EM) reconstruction algorithm. The SPECT system utilizes a compact semiconductor camera module previously developed in our group. The module is mounted perpendicular to the X-ray tube/CCD combination. It consists of a 64×64 pixellated CdZnTe detector and a parallel-hole tungsten collimator. The field of view is 1 square inch. Planar projections for SPECT reconstruction are obtained by rotating the animal in front of the detector. Gamma-ray and X-ray images are presented of phantoms and mice. Procedures for merging the anatomical and functional images are discussed. PMID:26538684

  2. SPECT data acquisition and image reconstruction in a stationary small animal SPECT/MRI system

    NASA Astrophysics Data System (ADS)

    Xu, Jingyan; Chen, Si; Yu, Jianhua; Meier, Dirk; Wagenaar, Douglas J.; Patt, Bradley E.; Tsui, Benjamin M. W.

    2010-04-01

    The goal of the study was to investigate data acquisition strategies and image reconstruction methods for a stationary SPECT insert that can operate inside an MRI scanner with a 12 cm bore diameter for simultaneous SPECT/MRI imaging of small animals. The SPECT insert consists of 3 octagonal rings of 8 MR-compatible CZT detectors per ring surrounding a multi-pinhole (MPH) collimator sleeve. Each pinhole is constructed to project the field-of-view (FOV) to one CZT detector. All 24 pinholes are focused to a cylindrical FOV of 25 mm in diameter and 34 mm in length. The data acquisition strategies we evaluated were optional collimator rotations to improve tomographic sampling; and the image reconstruction methods were iterative ML-EM with and without compensation for the geometric response function (GRF) of the MPH collimator. For this purpose, we developed an analytic simulator that calculates the system matrix with the GRF models of the MPH collimator. The simulator was used to generate projection data of a digital rod phantom with pinhole aperture sizes of 1 mm and 2 mm and with different collimator rotation patterns. Iterative ML-EM reconstruction with and without GRF compensation were used to reconstruct the projection data from the central ring of 8 detectors only, and from all 24 detectors. Our results indicated that without GRF compensation and at the default design of 24 projection views, the reconstructed images had significant artifacts. Accurate GRF compensation substantially improved the reconstructed image resolution and reduced image artifacts. With accurate GRF compensation, useful reconstructed images can be obtained using 24 projection views only. This last finding potentially enables dynamic SPECT (and/or MRI) studies in small animals, one of many possible application areas of the SPECT/MRI system. Further research efforts are warranted including experimentally measuring the system matrix for improved geometrical accuracy, incorporating the co

  3. A multipinhole small animal SPECT system with submillimeter spatial resolution

    SciTech Connect

    Funk, Tobias; Despres, Philippe; Barber, William C.; Shah, Kanai S.; Hasegawa, Bruce H.

    2006-05-15

    Single photon emission computed tomography (SPECT) is an important technology for molecular imaging studies of small animals. In this arena, there is an increasing demand for high performance imaging systems that offer improved spatial resolution and detection efficiency. We have designed a multipinhole small animal imaging system based on position sensitive avalanche photodiode (PSAPD) detectors with the goal of submillimeter spatial resolution and high detection efficiency, which will allow us to minimize the radiation dose to the animal and to shorten the time needed for the imaging study. Our design will use 8x24 mm{sup 2} PSAPD detector modules coupled to thallium-doped cesium iodide [CsI(Tl)] scintillators, which can achieve an intrinsic spatial resolution of 0.5 mm at 140 keV. These detectors will be arranged in rings of 24 modules each; the animal is positioned in the center of the 9 stationary detector rings which capture projection data from the animal with a cylindrical tungsten multipinhole collimator. The animal is supported on a bed which can be rocked about the central axis to increase angular sampling of the object. In contrast to conventional SPECT pinhole systems, in our design each pinhole views only a portion of the object. However, the ensemble of projection data from all of the multipinhole detectors provide angular sampling that is sufficient to reconstruct tomographic data from the object. The performance of this multipinhole PSAPD imaging system was simulated using a ray tracing program that models the appropriate point spread functions and then was compared against the performance of a dual-headed pinhole SPECT system. The detection efficiency of both systems was simulated and projection data of a hot rod phantom were generated and reconstructed to assess spatial resolution. Appropriate Poisson noise was added to the data to simulate an acquisition time of 15 min and an activity of 18.5 MBq distributed in the phantom. Both sets of data

  4. Integration of AdaptiSPECT, a small-animal adaptive SPECT imaging system

    PubMed Central

    Chaix, Cécile; Kovalsky, Stephen; Kosmider, Matthew; Barrett, Harrison H.; Furenlid, Lars R.

    2015-01-01

    AdaptiSPECT is a pre-clinical adaptive SPECT imaging system under final development at the Center for Gamma-ray Imaging. The system incorporates multiple adaptive features: an adaptive aperture, 16 detectors mounted on translational stages, and the ability to switch between a non-multiplexed and a multiplexed imaging configuration. In this paper, we review the design of AdaptiSPECT and its adaptive features. We then describe the on-going integration of the imaging system. PMID:26347197

  5. A small-animal imaging system capable of multipinhole circular/helical SPECT and parallel-hole SPECT

    PubMed Central

    Qian, Jianguo; Bradley, Eric L.; Majewski, Stan; Popov, Vladimir; Saha, Margaret S.; Smith, Mark F.; Weisenberger, Andrew G.; Welsh, Robert E.

    2008-01-01

    We have designed and built a small animal single photon emission computed tomography (SPECT) imaging system equipped with parallel-hole and multipinhole collimators and capable of circular or helical SPECT. Copper-beryllium parallel-hole collimators suitable for imaging the ~35 keV photons from the decay of 125I have been built and installed to achieve useful spatial resolution over a range of object-detector distances and to reduce imaging time on our dual-detector array. To address the resolution limitations in the parallel-hole SPECT and the sensitivity and limited field of view of single-pinhole SPECT, we have incorporated multipinhole circular and helical SPECT in addition to expanding the parallel-hole SPECT capabilities. The pinhole SPECT system is based on a 110 mm diameter circular detector equipped with a pixellated NaI(Tl) scintillator array (1×1×5 mm3/pixel). The helical trajectory is accomplished by two stepping motors controlling the rotation of the detector-support gantry and displacement of the animal bed along the axis of rotation of the gantry. Results obtained in SPECT studies of various phantoms show an enlarged field of view, very good resolution and improved sensitivity using multipinhole circular or helical SPECT. Collimators with one, three and five 1 mm diameter pinholes have been implemented and compared in these tests. Our objective is to develop a system on which one may readily select a suitable mode of either parallel-hole SPECT or pinhole circular or helical SPECT for a variety of small animal imaging applications. PMID:19701447

  6. A small-animal imaging system capable of multipinhole circular/helical SPECT and parallel-hole SPECT

    NASA Astrophysics Data System (ADS)

    Qian, Jianguo; Bradley, Eric L.; Majewski, Stan; Popov, Vladimir; Saha, Margaret S.; Smith, Mark F.; Weisenberger, Andrew G.; Welsh, Robert E.

    2008-08-01

    We have designed and built a small-animal single-photon emission computed tomography (SPECT) imaging system equipped with parallel-hole and multipinhole collimators and capable of circular or helical SPECT. Copper-beryllium parallel-hole collimators suitable for imaging the ˜35 keV photons from the decay of 125I have been built and installed to achieve useful spatial resolution over a range of object-detector distances and to reduce imaging time on our dual-detector array. To address the resolution limitations in the parallel-hole SPECT and the sensitivity and limited field of view of single-pinhole SPECT, we have incorporated multipinhole circular and helical SPECT in addition to expanding the parallel-hole SPECT capabilities. The pinhole SPECT system is based on a 110 mm diameter circular detector equipped with a pixellated NaI(Tl) scintillator array (1×1×5 mm 3/pixel). The helical trajectory is accomplished by two stepping motors controlling the rotation of the detector-support gantry and displacement of the animal bed along the axis of rotation of the gantry. Results obtained in SPECT studies of various phantoms show an enlarged field of view, very good resolution and improved sensitivity using multipinhole circular or helical SPECT. Collimators with one, three and five, 1-mm-diameter pinholes have been implemented and compared in these tests. Our objective is to develop a system on which one may readily select a suitable mode of either parallel-hole SPECT or pinhole circular or helical SPECT for a variety of small animal imaging applications.

  7. Design and development of MR-compatible SPECT systems for simultaneous SPECT-MR imaging of small animals

    NASA Astrophysics Data System (ADS)

    Tsui, Benjamin M. W.; Hugg, James W.; Xu, Jingyan; Chen, Si; Meier, Dirk; Edelstein, William; El-Sharkawy, Abdel; Wagenaar, Douglas J.; Patt, Bradley E.

    2011-03-01

    We describe a continuing design and development of MR-compatible SPECT systems for simultaneous SPECT-MR imaging of small animals. A first generation prototype SPECT system was designed and constructed to fit inside a MRI system with a gradient bore inner diameter of 12 cm. It consists of 3 angularly offset rings of 8 detectors (1"x1", 16x16 pixels MR-compatible solid-state CZT). A matching 24-pinhole collimator sleeve, made of a tungsten-compound, provides projections from a common FOV of ~25 mm. A birdcage RF coil for MRI data acquisition surrounds the collimator. The SPECT system was tested inside a clinical 3T MRI system. Minimal interference was observed on the simultaneously acquired SPECT and MR images. We developed a sparse-view image reconstruction method based on accurate modeling of the point response function (PRF) of each of the 24 pinholes to provide artifact-free SPECT images. The stationary SPECT system provides relatively low resolution of 3-5 mm but high geometric efficiency of 0.5- 1.2% for fast dynamic acquisition, demonstrated in a SPECT renal kinetics study using Tc-99m DTPA. Based on these results, a second generation prototype MR-compatible SPECT system with an outer diameter of 20 cm that fits inside a mid-sized preclinical MRI system is being developed. It consists of 5 rings of 19 CZT detectors. The larger ring diameter allows the use of optimized multi-pinhole collimator designs, such as high system resolution up to ~1 mm, high geometric efficiency, or lower system resolution without collimator rotation. The anticipated performance of the new system is supported by simulation data.

  8. Design and simulation of a high-resolution stationary SPECT system for small animals

    NASA Astrophysics Data System (ADS)

    Beekman, Freek J.; Vastenhouw, Brendan

    2004-10-01

    Exciting new SPECT systems can be created by combining pinhole imaging with compact high-resolution gamma cameras. These new systems are able to solve the problem of the limited sensitivity-resolution trade-off that hampers contemporary small animal SPECT. The design presented here (U-SPECT-III) uses a set of detectors placed in a polygonal configuration and a cylindrical collimator that contains 135 pinholes arranged in nine rings. Each ring contains 15 gold pinhole apertures that focus on the centre of the cylinder. A non-overlapping projection is acquired via each pinhole. Consequently, when a mouse brain is placed in the central field-of-view, each voxel in the cerebrum can be observed via 130 to 135 different pinholes simultaneously. A method for high-resolution scintillation detection is described that eliminates the depth-of-interaction problem encountered with pinhole cameras, and is expected to provide intrinsic detector resolutions better than 150 µm. By means of simulations U-SPECT-III is compared to a simulated dual pinhole SPECT (DP-SPECT) system with a pixelated array consisting of 2.0 × 2.0 mm NaI crystals. Analytic calculations indicate that the proposed U-SPECT-III system yields an almost four times higher linear and about sixty times higher volumetric system resolution than DP-SPECT, when the systems are compared at matching system sensitivity. In addition, it should be possible to achieve a 15 up to 30 times higher sensitivity with U-SPECT-III when the systems are compared at equal resolution. Simulated images of a digital mouse-brain phantom show much more detail with U-SPECT-III than with DP-SPECT. In a resolution phantom, 0.3 mm diameter cold rods are clearly visible with U-SPECT-III, whereas with DP-SPECT the smallest visible rods are about 0.6-0.8 mm. Furthermore, with U-SPECT-III, the image deformations outside the central plane of reconstruction that hamper conventional pinhole SPECT are strongly suppressed. Simulation results indicate

  9. SPECT-CT system for small animal imaging

    SciTech Connect

    Andrew Weisenberger; Randolph Wojcik; E.L. Bradley; Paul Brewer; Stanislaw Majewski; Jianguo Qian; Amoreena Ranck; Arunava Saha; Mark Smith; Robert Welsh

    2003-02-01

    The Detector Group at the Thomas Jefferson National Accelerator Facility (Jefferson Lab) and the Biology, Physics, and Applied Sciences Departments at the College of William and Mary are collaborating on the development of a miniature dual modality SPECT-CT system for mouse imaging. The detector heads of the SPECT sub-system are designed to be capable of imaging the gamma- and X-ray emissions (28-35 keV) of the radioactive isotope iodine-125 (I-125). Two different sets of I-125 imaging detectors are configured on a gantry that has an open-barrel type design. One set of detector heads is based on the 1-in square Hamamatsu R5900-M64 position sensitive photomultiplier tube coupled to crystal scintillator arrays. The other detector heads configured on the gantry are two 5-in diameter Hamamatsu R3292-based compact gamma cameras. The X-ray radiographic projections are obtained using a LIXI Inc. model LF-85-503-OS X-ray imaging system that has an active area of 5.5 cm in diameter. The open-barrel shaped gantry facilitates the positioning of various mini gamma-ray imaging detectors and the X-ray system. The data acquisition and gantry control is interfaced through a Macintosh G3 workstation. Preliminary SPECT reconstruction results using the R5900 based detector are presented.

  10. SPECT-CT System for Small Animal Imaging

    SciTech Connect

    A.G. Weisenberger; R. Wojcik; E.L. Bradley; P. Brewer; S. Majewski; J. Qian; A. Ranck; M.S. Saha; K. Smith; M.F. Smith; R.E. Welsh

    2001-11-01

    The Detector Group at the Thomas Jefferson National Accelerator Facility (Jefferson Lab) and the Biology, Physics and Applied Sciences Departments at the College of William and Mary are collaborating on the development of a miniature dual modality SPECT-CT system for mouse imaging. The detector heads of the SPECT sub-system are capable of imaging the gamma- and x-ray emissions (28-35 keV) of the radioactive isotope iodine-125 (I-125). Two different sets of I-125 imaging detectors are configured on a gantry which has an open-barrel type design. One set of detector heads is based on the 1 inch square Hamamatsu R5900-M64 position sensitive photomultiplier tube coupled to crystal scintillator arrays. The other detector heads configured on the gantry are two 5-inch diameter Hamamatsu R3292-based compact gamma cameras. The x-ray radiographic projections will be obtained using a LIXI Inc. model LF-85-503-OS x-ray imaging system that has an active area of 5.5 cm in diameter. The open-barrel shaped gantry facilitates the positioning of various mini gamma-ray imaging detectors and the x-ray system. The data acquisition and gantry control is interfaced through a Macintosh G3 workstation. SPECT reconstruction results using the R5900 based detector are presented.

  11. Improved Pose Measurement and Tracking System for Motion Correction of Awake, Unrestrained Small Animal SPECT Imaging

    SciTech Connect

    Goddard Jr, James Samuel; Baba, Justin S; Weisenberger, A G; Smith, M F

    2007-01-01

    An improved optical landmark-based pose measurement and tracking system has been developed to provide 3D animal pose data for a single photon emission computed tomography (SPECT) imaging system for awake, unanesthetized, unrestrained laboratory animals. The six degree of freedom animal position and orientation measurement data are time synchronized with the SPECT list mode data to provide for motion correction after the scan and before reconstruction. The tracking system employs infrared (IR) markers placed on the animal's head along with synchronized, strobed IR LEDs to illuminate the reflectors and freeze motion while minimizing reflections. A new design trinocular stereo image acquisition system using IEEE 1394 CMOS cameras acquires images of the animal with markers contained within a transparent enclosure. The trinocular configuration provides improved accuracy, range of motion, and robustness over the binocular stereo used previously. Enhanced software detects obstructions, automatically segments the markers, rejects reflections, performs marker correspondence, and calculates the 3D pose of the animal's head using image data from three cameras. The new hardware design provides more compact camera positioning with enhanced animal viewing through the 360 degree SPECT scan. This system has been implemented on a commercial scanner and tested using live mice and has been shown to be more reliable with higher accuracy than the previous system. Experimental results showing the improved motion tracking results are given.

  12. Quantitative analysis of L-SPECT system for small animal brain imaging

    NASA Astrophysics Data System (ADS)

    Rahman, Tasneem; Tahtali, Murat; Pickering, Mark R.

    2016-03-01

    This paper aims to investigate the performance of a newly proposed L-SPECT system for small animal brain imaging. The L-SPECT system consists of an array of 100 × 100 micro range diameter pinholes. The proposed detector module has a 48 mm by 48 mm active area and the system is based on a pixelated array of NaI crystals (10×10×10 mm elements) coupled with an array of position sensitive photomultiplier tubes (PSPMTs). The performance of this system was evaluated with pinhole radii of 50 μm, 60 μm and 100 μm. Monte Carlo simulation studies using the Geant4 Application for Tomographic Emission (GATE) software package validate the performance of this novel dual head L-SPECT system where a geometric mouse phantom is used to investigate its performance. All SPECT data were obtained using 120 projection views from 0° to 360° with a 3° step. Slices were reconstructed using conventional filtered back projection (FBP) algorithm. We have evaluated the quality of the images in terms of spatial resolution (FWHM) based on line spread function, the system sensitivity, the point source response function and the image quality. The sensitivity of our newly proposed L- SPECT system was about 4500 cps/μCi at 6 cm along with excellent full width at half-maximum (FWHM) using 50 μm pinhole aperture at several radii of rotation. The analysis results show the combination of excellent spatial resolution and high detection efficiency over an energy range between 20-160 keV. The results demonstrate that SPECT imaging using a pixelated L-SPECT detector module is applicable in a quantitative study of mouse brain imaging.

  13. System calibration and image reconstruction for a new small-animal SPECT system

    NASA Astrophysics Data System (ADS)

    Chen, Yi-Chun

    A novel small-animal SPECT imager, FastSPECT II, was recently developed at the Center for Gamma-Ray Imaging. FastSPECT II consists of two rings of eight modular scintillation cameras and list-mode data-acquisition electronics that enable stationary and dynamic imaging studies. The instrument is equipped with exchangeable aperture assemblies and adjustable camera positions for selections of magnifications, pinhole sizes, and fields of view (FOVs). The purpose of SPECT imaging is to recover the radiotracer distribution in the object from the measured image data. Accurate knowledge of the imaging system matrix (referred to as H) is essential for image reconstruction. To assure that all of the system physics is contained in the matrix, experimental calibration methods for the individual cameras and the whole imaging system were developed and carefully performed. The average spatial resolution over the FOV of FastSPECT II in its low-magnification (2.4X) configuration is around 2.4 mm, computed from the Fourier crosstalk matrix. The system sensitivity measured with a 99mTc point source at the center of the FOV is about 267 cps/MBq. The system detectability was evaluated by computing the ideal-observer performance on SKE/BKE (signal-known-exactly/background-known-exactly) detection tasks. To reduce the system-calibration time and achieve finer reconstruction grids, two schemes for interpolating H were implemented and compared: these are centroid interpolation with Gaussian fitting and Fourier interpolation. Reconstructed phantom and mouse-cardiac images demonstrated the effectiveness of the H-matrix interpolation. Tomographic reconstruction can be formulated as a linear inverse problem and solved using statistical-estimation techniques. Several iterative reconstruction algorithms were introduced, including maximum-likelihood expectation-maximization (ML-EM) and its ordered-subsets (OS) version, and some least-squares (LS) and weighted-least-squares (WLS) algorithms such

  14. A restraint-free small animal SPECT imaging system with motion tracking

    SciTech Connect

    Weisenberger, A.G.; Gleason, S.S.; Goddard, J.; Kross, B.; Majewski, S.; Meikle, S.R.; Paulus, M.J.; Pomper, M.; Popov, V.; Smith, M.F.; Welch, B.L.; Wojcik, R.

    2005-06-01

    We report on an approach toward the development of a high-resolution single photon emission computed tomography (SPECT) system to image the biodistribution of radiolabeled tracers such as Tc-99m and I-125 in unrestrained/unanesthetized mice. An infrared (IR)-based position tracking apparatus has been developed and integrated into a SPECT gantry. The tracking system is designed to measure the spatial position of a mouse's head at a rate of 10-15 frames per second with submillimeter accuracy. The high-resolution, gamma imaging detectors are based on pixellated NaI(Tl) crystal scintillator arrays, position-sensitive photomultiplier tubes, and novel readout circuitry requiring fewer analog-digital converter (ADC) channels while retaining high spatial resolution. Two SPECT gamma camera detector heads based upon position-sensitive photomultiplier tubes have been built and installed onto the gantry. The IR landmark-based pose measurement and tracking system is under development to provide animal position data during a SPECT scan. The animal position and orientation data acquired by the tracking system will be used for motion correction during the tomographic image reconstruction.

  15. Development of a combined microSPECT/CT system for small animal imaging

    NASA Astrophysics Data System (ADS)

    Sun, Mingshan

    Modern advances in the biomedical sciences have placed increased attention on small animals such as mice and rats as models of human biology and disease in biological research and pharmaceutical development. Their small size and fast breeding rate, their physiologic similarity to human, and, more importantly, the availability of sophisticated genetic manipulations, all have made mice and rats the laboratory mammals of choice in these experimental studies. However, the increased use of small animals in biomedical research also calls for new instruments that can measure the anatomic and metabolic information noninvasively with adequate spatial resolution and measurement sensitivity to facilitate these studies. This dissertation describes the engineering development of a combined single photon emission computed tomography (SPECT) and X-ray computed tomography (CT) system dedicated for small animals imaging. The system aims to obtain both the anatomic and metabolic images with submillimeter spatial resolution in a way that the data can be correlated to provide improved image quality and to offer more complete biological evaluation for biomedical studies involving small animals. The project requires development of complete microSPECT and microCT subsystems. Both subsystems are configured with a shared gantry and animal bed with integrated instrumentation for data acquisition and system control. The microCT employs a microfocus X-ray tube and a CCD-based detector for low noise, high resolution imaging. The microSPECT utilizes three semiconductor detectors coupled with pinhole collimators. A significant contribution of this dissertation project is the development of iterative algorithms with geometrical compensation that allows radionuclide images to be reconstructed at submillimeter spatial resolution, but with significantly higher detection efficiency than conventional methods. Both subsystems are capable of helical scans, offering lengthened field of view and improved

  16. Preliminary evaluation of the tomographic performance of the mediSPECT small animal imaging system

    NASA Astrophysics Data System (ADS)

    Accorsi, Roberto; Curion, Assunta Simona; Frallicciardi, Paola; Lanza, Richard C.; Lauria, Adele; Mettivier, Giovanni; Montesi, Maria Cristina; Russo, Paolo

    2007-02-01

    We report on the tests of a prototype (MediSPECT) system developed at University & INFN Napoli, for Single Photon Emission Computed Tomography (SPECT) imaging on small animals with a small Field of View (FoV) and high spatial resolution. MediSPECT is a SPECT imaging system based on a 1-mm-thick CdTe pixel detector, bump-bonded to the Medipix2 CMOS readout circuit operating in single-photon counting. The CdTe detector has 256×256 square array of pixels arranged with a 55 μm pitch, for a sensitive area of 14×14 mm 2. In its present version, this system implements a single detector head, mounted on a rotating gantry. For preliminary testing and calibration of the acquisition equipment and image reconstruction algorithms, 90 projections of a γ-ray point source ( 109Cd) through a single pinhole (diameter 0.4 mm; radius of rotation about 2.5 cm; focal length about 4.5 cm) were acquired for 20 min each in a step-and-shoot mode. Capillaries, 800 μm in diameter, were arranged in a Y-shape to form a more complex phantom ( 125I, 1 mm pinhole diameter, 45 projections, each acquired for 25 min). Images were reconstructed with a custom algorithm implementing standard OS-EM with center of rotation correction and spatial resolution of 0.2 mm over a FoV of 2 mm was obtained.

  17. Design optimization of a small-animal SPECT system using LGSO continuous crystals and micro parallel-hole collimators

    NASA Astrophysics Data System (ADS)

    Kim, Joong Hyun; Ito, Mikiko; Kim, Soo Mee; Hong, Seong Jong; Lee, Jae Sung

    2015-07-01

    A small-animal single photon emission computed tomography (SPECT) system having compact size and low cost was designed using monolithic LGSO scintillation crystals and micro parallel-hole collimators through Monte Carlo simulations. A spatial resolution of ~1 mm and a sensitivity of ~100 cps/MBq were achieved with a four-head SPECT system. A hot rod with a diameter of 1.0 mm was resolved in the SPECT image of the ultra-micro hot spot phantom. Using a thin monolithic crystal and micro collimator, we achieved high spatial resolution and high sensitivity.

  18. A SPECT camera for combined MRI and SPECT for small animals

    NASA Astrophysics Data System (ADS)

    Meier, D.; Wagenaar, D. J.; Chen, S.; Xu, J.; Yu, J.; Tsui, B. M. W.

    2011-10-01

    We describe an MR-compatible SPECT camera for small animals. The SPECT camera system can be inserted into the bore of a state-of-the-art MRI system and allows researchers to acquire tomographic images from a mouse in-vivo with the MRI and the SPECT acquiring simultaneously. The SPECT system provides functional information, while MRI provides anatomical information. Until today it was impossible to operate conventional SPECT inside the MRI because of mutual interference. The new SPECT technology is based on semiconductor radiation sensors (CZT, ASICs), and it fits into conventional high field MRI systems with a minimum 12-cm bore size. The SPECT camera has an MR-compatible multi-pinhole collimator for mice with a Ø25-mm field-of-view. For the work reported here we assembled a prototype SPECT camera system and acquired SPECT and MRI data from radioactive sources and resolution phantoms using the camera outside and inside the MRI.

  19. A SPECT Camera for Combined MRI and SPECT for Small Animals.

    PubMed

    Meier, D; Wagenaar, D J; Chen, S; Xu, J; Yu, J; Tsui, B M W

    2011-10-01

    We describe an MR-compatible SPECT camera for small animals. The SPECT camera system can be inserted into the bore of a state-of-the-art MRI system and allows researchers to acquire tomographic images from a mouse in-vivo with the MRI and the SPECT acquiring simultaneously. The SPECT system provides functional information, while MRI provides anatomical information. Until today it was impossible to operate conventional SPECT inside the MRI because of mutual interference. The new SPECT technology is based on semiconductor radiation sensors (CZT, ASICs), and it fits into conventional high field MRI systems with a minimum 12-cm bore size. The SPECT camera has an MR-compatible multi-pinhole collimator for mice with a ø25-mm field-of-view. For the work reported here we assembled a prototype SPECT camera system and acquired SPECT and MRI data from radioactive sources and resolution phantoms using the camera outside and inside the MRI. PMID:21966076

  20. A SPECT Camera for Combined MRI and SPECT for Small Animals

    PubMed Central

    Meier, D.; Wagenaar, D. J.; Chen, S.; Xu, J.; Yu, J.; Tsui, B. M. W.

    2010-01-01

    We describe an MR-compatible SPECT camera for small animals. The SPECT camera system can be inserted into the bore of a state-of-the-art MRI system and allows researchers to acquire tomographic images from a mouse in-vivo with the MRI and the SPECT acquiring simultaneously. The SPECT system provides functional information, while MRI provides anatomical information. Until today it was impossible to operate conventional SPECT inside the MRI because of mutual interference. The new SPECT technology is based on semiconductor radiation sensors (CZT, ASICs), and it fits into conventional high field MRI systems with a minimum 12-cm bore size. The SPECT camera has an MR-compatible multi-pinhole collimator for mice with a ø25-mm field-of-view. For the work reported here we assembled a prototype SPECT camera system and acquired SPECT and MRI data from radioactive sources and resolution phantoms using the camera outside and inside the MRI. PMID:21966076

  1. Implementation and assessment of an animal management system for small-animal micro-CT / micro-SPECT imaging

    NASA Astrophysics Data System (ADS)

    Holdsworth, David W.; Detombe, Sarah A.; Chiodo, Chris; Fricke, Stanley T.; Drangova, Maria

    2011-03-01

    Advances in laboratory imaging systems for CT, SPECT, MRI, and PET facilitate routine micro-imaging during pre-clinical investigations. Challenges still arise when dealing with immune-compromised animals, biohazardous agents, and multi-modality imaging. These challenges can be overcome with an appropriate animal management system (AMS), with the capability for supporting and monitoring a rat or mouse during micro-imaging. We report the implementation and assessment of a new AMS system for mice (PRA-3000 / AHS-2750, ASI Instruments, Warren MI), designed to be compatible with a commercial micro-CT / micro-SPECT imaging system (eXplore speCZT, GE Healthcare, London ON). The AMS was assessed under the following criteria: 1) compatibility with the imaging system (i.e. artifact generation, geometric dimensions); 2) compatibility with live animals (i.e. positioning, temperature regulation, anesthetic supply); 3) monitoring capabilities (i.e. rectal temperature, respiratory and cardiac monitoring); 4) stability of co-registration; and 5) containment. Micro-CT scans performed using a standardized live-animal protocol (90 kVp, 40 mA, 900 views, 16 ms per view) exhibited low noise (+/-19 HU) and acceptable artifact from high-density components within the AMS (e.g. ECG pad contacts). Live mice were imaged repeatedly (with removal and replacement of the AMS) and spatial registration was found to be stable to within +/-0.07 mm. All animals tolerated enclosure within the AMS for extended periods (i.e. > one hour) without distress, based on continuous recordings of rectal temperature, ECG waveform and respiratory rate. A sealed AMS system extends the capability of a conventional micro-imaging system to include immune-compromised and biosafety level 2 mouse-imaging protocols.

  2. Performance evaluation of a compact PET/SPECT/CT tri-modality system for small animal imaging applications

    NASA Astrophysics Data System (ADS)

    Wei, Qingyang; Wang, Shi; Ma, Tianyu; Wu, Jing; Liu, Hui; Xu, Tianpeng; Xia, Yan; Fan, Peng; Lyu, Zhenlei; Liu, Yaqiang

    2015-06-01

    PET, SPECT and CT imaging techniques are widely used in preclinical small animal imaging applications. In this paper, we present a compact small animal PET/SPECT/CT tri-modality system. A dual-functional, shared detector design is implemented which enables PET and SPECT imaging with a same LYSO ring detector. A multi-pinhole collimator is mounted on the system and inserted into the detector ring in SPECT imaging mode. A cone-beam CT consisting of a micro focus X-ray tube and a CMOS detector is implemented. The detailed design and the performance evaluations are reported in this paper. In PET imaging mode, the measured NEMA based spatial resolution is 2.12 mm (FWHM), and the sensitivity at the central field of view (CFOV) is 3.2%. The FOV size is 50 mm (∅)×100 mm (L). The SPECT has a spatial resolution of 1.32 mm (FWHM) and an average sensitivity of 0.031% at the center axial, and a 30 mm (∅)×90 mm (L) FOV. The CT spatial resolution is 8.32 lp/mm @10%MTF, and the contrast discrimination function value is 2.06% with 1.5 mm size cubic box object. In conclusion, a compact, tri-modality PET/SPECT/CT system was successfully built with low cost and high performance.

  3. Real-time Awake Animal Motion Tracking System for SPECT Imaging

    SciTech Connect

    Goddard Jr, James Samuel; Baba, Justin S; Lee, Seung Joon; Weisenberger, A G; Stolin, A; McKisson, J; Smith, M F

    2008-01-01

    Enhancements have been made in the development of a real-time optical pose measurement and tracking system that provides 3D position and orientation data for a single photon emission computed tomography (SPECT) imaging system for awake, unanesthetized, unrestrained small animals. Three optical cameras with infrared (IR) illumination view the head movements of an animal enclosed in a transparent burrow. Markers placed on the head provide landmark points for image segmentation. Strobed IR LED s are synchronized to the cameras and illuminate the markers to prevent motion blur for each set of images. The system using the three cameras automatically segments the markers, detects missing data, rejects false reflections, performs trinocular marker correspondence, and calculates the 3D pose of the animal s head. Improvements have been made in methods for segmentation, tracking, and 3D calculation to give higher speed and more accurate measurements during a scan. The optical hardware has been installed within a Siemens MicroCAT II small animal scanner at Johns Hopkins without requiring functional changes to the scanner operation. The system has undergone testing using both phantoms and live mice and has been characterized in terms of speed, accuracy, robustness, and reliability. Experimental data showing these motion tracking results are given.

  4. Resolution-recovery-embedded image reconstruction for a high-resolution animal SPECT system.

    PubMed

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

    2014-11-01

    The small-animal High-Resolution SPECT (HiReSPECT) is a dedicated dual-head gamma camera recently designed and developed in our laboratory for imaging of murine models. Each detector is composed of an array of 1.2 × 1.2 mm(2) (pitch) pixelated CsI(Na) crystals. Two position-sensitive photomultiplier tubes (H8500) are coupled to each head's crystal. In this paper, we report on a resolution-recovery-embedded image reconstruction code applicable to the system and present the experimental results achieved using different phantoms and mouse scans. Collimator-detector response functions (CDRFs) were measured via a pixel-driven method using capillary sources at finite distances from the head within the field of view (FOV). CDRFs were then fitted by independent Gaussian functions. Thereafter, linear interpolations were applied to the standard deviation (σ) values of the fitted Gaussians, yielding a continuous map of CDRF at varying distances from the head. A rotation-based maximum-likelihood expectation maximization (MLEM) method was used for reconstruction. A fast rotation algorithm was developed to rotate the image matrix according to the desired angle by means of pre-generated rotation maps. The experiments demonstrated improved resolution utilizing our resolution-recovery-embedded image reconstruction. While the full-width at half-maximum (FWHM) radial and tangential resolution measurements of the system were over 2 mm in nearly all positions within the FOV without resolution recovery, reaching around 2.5 mm in some locations, they fell below 1.8 mm everywhere within the FOV using the resolution-recovery algorithm. The noise performance of the system was also acceptable; the standard deviation of the average counts per voxel in the reconstructed images was 6.6% and 8.3% without and with resolution recovery, respectively. PMID:24986422

  5. Development and testing of a restraint free small animal SPECT imaging system with infrared based motion tracking

    SciTech Connect

    Weisenberger, A.G.; Kross, B.; Gleason, S.S.; Goddard, J.; Majewski, S.; Meikle, S.R.; Paulus, M.J.; Pomper, M.; Popov, V.; Smith, M.F.; Welch, B.L.; Wojcik, R.

    2003-10-01

    The development and initial evaluation of a high-resolution single photon emission tomography (SPECT) based system to image the biodistribution of radiolabeled tracers such as Tc-99m and I-125 in unrestrained/un-anesthetized mice. An infrared (IR) based position tracking apparatus has been developed and integrated into a SPECT gantry. The tracking system is designed to measure the spatial position of a mouse's head at a rate of 10-15 frames per second with sub-millimeter accuracy. The high resolution, gamma imaging detectors are based on pixelated NaI(Tl) crystal scintillator arrays, arrays of compact position-sensitive photomultiplier tubes and novel readout circuitry for lower device cost while retaining high spatial resolution. Two SPECT gamma camera detector heads based on a 4 /spl times/ 8 array of Hamamatsu R8520-C12 position sensitive photomultiplier tubes have been built and installed onto the gantry. The IR landmark-based pose measurement and tracking system is under development to provide animal position data during a SPECT scan. The animal position and orientation data acquired by the IR tracking system is used for motion correction during the tomographic image reconstruction.

  6. Design of a high-resolution small-animal SPECT-CT system sharing a CdTe semiconductor detector

    NASA Astrophysics Data System (ADS)

    Ryu, Hyun-Ju; Lee, Young-Jin; Lee, Seung-Wan; Cho, Hyo-Min; Choi, Yu-Na; Kim, Hee-Joung

    2012-07-01

    A single photon emission computed tomography (SPECT) system with a co-registered X-y computed tomography (CT) system allows the convergence of functional information and morphologic information. The localization of radiopharmaceuticals on a SPECT can be enhanced by combining the SPECT with an anatomical modality, such as X-ray CT. Gamma-ray imaging for nuclear medicine devices and X-ray imaging systems for diagnostics has recently been developed based on semiconductor detectors, and semiconductor detector materials such as cadmium telluride (CdTe) or cadmium zinc telluride (CZT) are available for both X-ray and gamma-ray systems for small-animal imaging. CdTe or CZT detectors provide strong absorption and high detection efficiency of high energy X-ray and gamma-ray photons because of their large atomic numbers. In this study, a pinhole collimator SPECT system sharing a cadmium telluride (CdTe) detector with a CT was designed. The GEANT4 application for tomographic emission (GATE) v.6.1 was used for the simulation. The pinhole collimator was designed to obtain a high spatial resolution of the SPECT system. The acquisition time for each projection was 40 seconds, and 60 projections were obtained for tomographic image acquisition. The reconstruction was performed using ordered subset expectation maximization (OS-EM) algorithms. The sensitivity and the spatial resolution were measured on the GATE simulation to evaluate the system characteristics. The spatial resolution of the system calculated from the FWHM of Gaussian fitted PSF curve was 0.69 mm, and the sensitivity of the system was measured to be 0.354 cps/kBq by using a Tc-99m point source of 1 MBq for 800 seconds. A phantom study was performed to verify the design of the dual imaging modality system. The system will be built as designed, and it can be applied as a pre-clinical imaging system.

  7. Small-animal SPECT and SPECT/CT: important tools for preclinical investigation.

    PubMed

    Franc, Benjamin L; Acton, Paul D; Mari, Carina; Hasegawa, Bruce H

    2008-10-01

    The need to study dynamic biologic processes in intact small-animal models of disease has stimulated the development of high-resolution nuclear imaging methods. These methods are capable of clarifying molecular interactions important in the onset and progression of disease, assessing the biologic relevance of drug candidates and potential imaging agents, and monitoring therapeutic effectiveness of pharmaceuticals serially within a single-model system. Single-photon-emitting radionuclides have many advantages in these applications, and SPECT can provide 3-dimensional spatial distributions of gamma- (and x-) ray-emitting radionuclide imaging agents or therapeutics. Furthermore, combining SPECT with CT in a SPECT/CT system can assist in defining the anatomic context of biochemical processes and improve the quantitative accuracy of the SPECT data. Over the past decade, dedicated small-animal SPECT and SPECT/CT systems have been developed in academia and industry. Although significant progress in this arena has been realized through system development and biologic application, further innovation continues to address challenges in camera sensitivity, spatial resolution, and image reconstruction and quantification. The innumerable applications of small-animal SPECT and SPECT/CT in drug development, cardiology, neurology, and oncology are stimulating further investment in education, research, and development of these dedicated small-animal imaging modalities. PMID:18794275

  8. SemiSPECT: A Small-animal Imaging System Based on Eight CdZnTe Pixel Detectors

    PubMed Central

    Peterson, Todd E.; Kim, Hyunki; Crawford, Michael J.; Gershman, Benjamin M.; Hunter, William C.J.; Barber, H. Bradford; Furenlid, Lars R.; Wilson, Donald W.; Woolfenden, James M.; Barrett, Harrison H.

    2015-01-01

    We have constructed a SPECT system for small animals that utilizes eight CdZnTe pixel detectors. The eight detectors are arranged in a single octagonal ring, where each views the object to be imaged through a single pinhole. Additional projections are obtained via rotation of the animal. Each CdZnTe detector is approximately 2 mm in thickness and is patterned on one surface into a 64×64 array of pixels with 380 micron pitch. We have designed an electronic readout system capable of collecting data from the eight detectors in listmode. In this scheme each event entry for a gamma-ray hit includes the pulse height of the pixel with the largest signal and the pulse height for each of its eight nearest neighbors. We present details of the overall design, the electronics, and system performance. PMID:26568674

  9. The multi-module multi-resolution SPECT system: A tool for variable-pinhole small-animal imaging

    NASA Astrophysics Data System (ADS)

    Hesterman, Jacob Yost

    The multi-module, multi-resolution SPECT system (M 3R) was developed and evaluated at the University of Arizona's Center for Gamma-Ray Imaging (CGRI). The system consists of four modular gamma cameras stationed around a Cerrobend shielding assembly. Slots machined into the shielding allow for the easy interchange of pinhole apertures, providing M3R with excellent hardware flexibility. Motivation for the system included serving as a prototype for a tabletop, small-animal SPECT system, acting as a testbed for image quality by enabling the experimental validation of imaging theory, and aiding in the development of techniques for the emerging field of adaptive SPECT imaging. Development of the system included design and construction of the shielding assembly and pinhole apertures. The issue of pinhole design and evaluation represents a recurring theme of the presented work. Existing calibration methods were adapted for use with M3R. A new algorithm, the contracting grid-search algorithm, that is capable of being executed in hardware was developed for use in position estimation. The algorithm was successfully applied in software and progress was made in hardware implementation. Special equipment and interpolation techniques were also developed to deal with M3R's unique system design and calibration requirements. A code library was created to simplify the many image processing steps required to realize successful analysis of measured image and calibration data and to achieve reconstruction. Observer studies were performed using both projection data and reconstructed images. These observer studies sought to explore signal-detection and activity estimation for various pinhole apertures. Special attention was paid to object variability, including the development and statistical analysis of a phantom capable of generating multiple realizations of a random, textured background. The results of these studies indicate potential for multiple-pinhole, multiplexed apertures but

  10. Awake animal SPECT: Overview and initial results

    SciTech Connect

    Weisenberger, A G; Majewski, S; McKisson, J; Popov, V; Proffitt, J; Stolin, A; Baba, J S; Goddard, J S; Lee, S J; Smith, M F; Tsui, B; Pomper, M

    2009-02-01

    A SPECT / X-ray CT system configured at Johns Hopkins University to image the biodistribution of radiopharmaceuticals in unrestrained, un-anesthetized mice has been constructed and tested on awake mice. The system was built by Thomas Jefferson National Accelerator Facility and Oak Ridge National Laboratory. SPECT imaging is accomplished using two gamma cameras, 10 cm × 20 cm in size based on a 2 × 4 array of Hamamatsu H8500 flat panel position sensitive photomultiplier tubes. A real-time optical tracking system utilizing three infrared cameras provides time stamped pose data of an awake mouse head during a SPECT scan. The six degrees of freedom (three translational and three rotational) pose data are used for motion correction during 3-D tomographic list-mode iterative image reconstruction. SPECT reconstruction of awake, unrestrained mice with motion compensation for head movement has been accomplished.

  11. Experimental task-based optimization of a four-camera variable-pinhole small-animal SPECT system

    NASA Astrophysics Data System (ADS)

    Hesterman, Jacob Y.; Kupinski, Matthew A.; Furenlid, Lars R.; Wilson, Donald W.

    2005-04-01

    We have previously utilized lumpy object models and simulated imaging systems in conjunction with the ideal observer to compute figures of merit for hardware optimization. In this paper, we describe the development of methods and phantoms necessary to validate or experimentally carry out these optimizations. Our study was conducted on a four-camera small-animal SPECT system that employs interchangeable pinhole plates to operate under a variety of pinhole configurations and magnifications (representing optimizable system parameters). We developed a small-animal phantom capable of producing random backgrounds for each image sequence. The task chosen for the study was the detection of a 2mm diameter sphere within the phantom-generated random background. A total of 138 projection images were used, half of which included the signal. As our observer, we employed the channelized Hotelling observer (CHO) with Laguerre-Gauss channels. The signal-to-noise (SNR) of this observer was used to compare different system configurations. Results indicate agreement between experimental and simulated data with higher detectability rates found for multiple-camera, multiple-pinhole, and high-magnification systems, although it was found that mixtures of magnifications often outperform systems employing a single magnification. This work will serve as a basis for future studies pertaining to system hardware optimization.

  12. Real-time landmark-based unrestrained animal tracking system for motion-corrected PET/SPECT imaging

    SciTech Connect

    J.S. Goddard; S.S. Gleason; M.J. Paulus; Stanislaw Majewski; Vladimir Popov; Mark Smith; Andrew Weisenberger; Benjamin Welch; Randolph Wojcik

    2003-08-01

    Oak Ridge National Laboratory (ORNL) and Jefferson Lab and are collaborating to develop a new high-resolution single photon emission tomography (SPECT) instrument to image unrestrained laboratory animals. This technology development will allow functional imaging studies to be performed on the animals without the use of anesthetic agents. This technology development could have eventual clinical applications for performing functional imaging studies on patients that cannot remain still (Parkinson's patients, Alzheimer's patients, small children, etc.) during a PET or SPECT scan. A key component of this new device is the position tracking apparatus. The tracking apparatus is an integral part of the gantry and designed to measure the spatial position of the animal at a rate of 10-15 frames per second with sub-millimeter accuracy. Initial work focuses on brain studies where anesthetic agents or physical restraint can significantly impact physiologic processes.

  13. MediSPECT: Single photon emission computed tomography system for small field of view small animal imaging based on a CdTe hybrid pixel detector

    NASA Astrophysics Data System (ADS)

    Accorsi, R.; Autiero, M.; Celentano, L.; Chmeissani, M.; Cozzolino, R.; Curion, A. S.; Frallicciardi, P.; Laccetti, P.; Lanza, R. C.; Lauria, A.; Maiorino, M.; Marotta, M.; Mettivier, G.; Montesi, M. C.; Riccio, P.; Roberti, G.; Russo, P.

    2007-02-01

    We describe MediSPECT, a new scanner developed at University and INFN Napoli, for SPECT studies on small animals with a small field of view (FOV) and high spatial resolution. The CdTe pixel detector (a 256×256 matrix of 55 μm square pixels) operating in single photon counting for detection of gamma-rays with low and medium energy (e.g. 125I, 27-35 keV, 99mTc, 140 keV), is bump bonded to the Medipix2 readout chip. The FOV of the MediSPECT scanner with a coded aperture mask collimator ranges from 6.3 mm (system spatial resolution 110 μm at 27-35 keV) to 24.3 mm. With a 0.30 mm pinhole the FOV ranges from 2.4 to 29 mm (where the system spatial resolution is 1.0 mm at 27-35 keV and 2.0 mm at 140 keV). MediSPECT will be used for in vivo imaging of small organs or tissue structures in mouse, e.g., brain, thyroid, heart or tumor.

  14. Performance evaluation of a newly developed high-resolution, dual-head animal SPECT system based on the NEMA NU1-2007 standard.

    PubMed

    Moji, Vahideh; Zeratkar, Navid; Farahani, Mohammad Hossein; Aghamiri, Mahmoud Reza; Sajedi, Salar; Teimourian, Behnoosh; Ghafarian, Pardis; Sarkar, Saeed; Ay, Mohammad Reza

    2014-01-01

    Small-animal single-photon emission computed tomography (SPECT) system plays an important role in the field of drug development and investigation of potential drugs in the preclinical phase. The small-animal High-Resolution SPECT (HiReSPECT) scanner has been recently designed and developed based on compact and high-resolution detectors. The detectors are based on a high-resolution parallel hole collimator, a cesium iodide (sodium-activated) pixelated crystal array and two H8500 position-sensitive photomultiplier tubes. In this system, a full set of data cor- rections such as energy, linearity, and uniformity, together with resolution recovery option in reconstruction algorithms, are available. In this study, we assessed the performance of the system based on NEMA-NU1-2007 standards for pixelated detector cameras. Characterization of the HiReSPECT was performed by measure- ment of the physical parameters including planar and tomographic performance. The planar performance of the system was characterized with flood-field phantom for energy resolution and uniformity. Spatial resolution and sensitivity were evaluated as functions of distance with capillary tube and cylindrical source, respectively. Tomographic spatial resolution was characterized as a function of radius of rotation (ROR). A dedicated hot rod phantom and image quality phantom was used for the evaluation of overall tomographic quality of the HiReSPECT. The results showed that the planar spatial resolution was ~ 1.6 mm and ~ 2.3 mm in terms of full-width at half-maximum (FWHM) along short- and long-axis dimensions, respectively, when the source was placed on the detector surface. The integral uniformity of the system after uniformity correction was 1.7% and 1.2% in useful field of view (UFOV) and central field of view (CFOV), respectively. System sensitivity on the collimator surface was 1.31 cps/μCi and didn't vary significantly with distance. Mean tomographic spatial resolution was measured ~ 1.7 mm

  15. Dual-headed SPECT for awake animal brain imaging

    SciTech Connect

    Lee, Seung Joon; Weisenberger, A G; McKisson, J; Goddard Jr, James Samuel; Baba, Justin S; Smith, M F

    2011-01-01

    Abstract- Motion-corrected awake animal imaging is needed for normal-state investigations of models of neurological disease and brain activity. The awake animal brain SPECT/CT system, AwakeSPECT at Johns Hopkins University has in the past used a single gamma camera for imaging. Enhancements have been made by adding a pinhole collimator to the second gamma camera at the opposite side which has been previously equipped parallel hole collimator. Geometry calibration was performed using a custom built quality control phantom containing three Co-57 point sources and applied to the tomographic reconstruction code. Hot-rod phantom scans with Tc-99m were performed to test sensitivity and resolution improvements. The reconstruction results show significant resolution and sensitivity improvements.

  16. Dual-headed SPECT for awake animal brain imaging

    SciTech Connect

    S. Lee, B. Kross, D. Weisenberger, J. McKisson, J.S. Goddard, J.S. Baba, M.S. Smith

    2012-02-01

    Motion-corrected awake animal imaging is needed for normal-state investigations of models of neurological disease and brain activity. The awake animal brain SPECT/CT system, AwakeSPECT at Johns Hopkins University has in the past used a single gamma camera for imaging. Enhancements have been made by adding a pinhole collimator to the second gamma camera at the opposite side which has been previously equipped parallel hole collimator. Geometry calibration was performed using a custom built quality control phantom containing three Co-57 point sources and applied to the tomographic reconstruction code. Hot-rod phantom scans with Tc-99m were performed to test sensitivity and resolution improvements. The reconstruction results show significant resolution and sensitivity improvements.

  17. Comparison of photon counting and conventional scintillation detectors in a pinhole SPECT system for small animal imaging: Monte carlo simulation studies

    NASA Astrophysics Data System (ADS)

    Lee, Young-Jin; Park, Su-Jin; Lee, Seung-Wan; Kim, Dae-Hong; Kim, Ye-Seul; Kim, Hee-Joung

    2013-05-01

    The photon counting detector based on cadmium telluride (CdTe) or cadmium zinc telluride (CZT) is a promising imaging modality that provides many benefits compared to conventional scintillation detectors. By using a pinhole collimator with the photon counting detector, we were able to improve both the spatial resolution and the sensitivity. The purpose of this study was to evaluate the photon counting and conventional scintillation detectors in a pinhole single-photon emission computed tomography (SPECT) system. We designed five pinhole SPECT systems of two types: one type with a CdTe photon counting detector and the other with a conventional NaI(Tl) scintillation detector. We conducted simulation studies and evaluated imaging performance. The results demonstrated that the spatial resolution of the CdTe photon counting detector was 0.38 mm, with a sensitivity 1.40 times greater than that of a conventional NaI(Tl) scintillation detector for the same detector thickness. Also, the average scatter fractions of the CdTe photon counting and the conventional NaI(Tl) scintillation detectors were 1.93% and 2.44%, respectively. In conclusion, we successfully evaluated various pinhole SPECT systems for small animal imaging.

  18. Multiple-pinhole SPECT/CBCT system and its application on animal model on tumor

    NASA Astrophysics Data System (ADS)

    Bao, Shanglian; Li, Jun

    2011-12-01

    Characterized by wisdom and creativity, human beings are huge, complex, giant systems. Each person's life is experienced the process of birth, growth, aging and death. The genetic stability keeps human beings no change, and the mutation keeps the human beings in progress. The balance between stability and mutation are controlled by the nature laws automatically. But the balance often broken because the body's biochemical processes is out of order in vivo, which is scaled by quantitative concentrations for all molecular in human body. Now day, the biomedical imaging tools can investigate these process quantitatively.

  19. Intrinsic Feature Pose Measurement for Awake Animal SPECT Imaging

    SciTech Connect

    Goddard Jr, James Samuel; Baba, Justin S; Lee, Seung Joon; Weisenberger, A G; Stolin, A; McKisson, J; Smith, M F

    2009-01-01

    New developments have been made in optical motion tracking for awake animal imaging that measures 3D position and orientation (pose) for a single photon emission computed tomography (SPECT) imaging system. Ongoing SPECT imaging research has been directed towards head motion measurement for brain studies in awake, unrestrained mice. In contrast to previous results using external markers, this work extracts and tracks intrinsic features from multiple camera images and computes relative pose from the tracked features over time. Motion tracking thus far has been limited to measuring extrinsic features such as retro-reflective markers applied to the mouse s head. While this approach has been proven to be accurate, the additional animal handling required to attach the markers is undesirable. A significant improvement in the procedure is achieved by measuring the pose of the head without extrinsic markers using only the external surface appearance. This approach is currently being developed with initial results presented here. The intrinsic features measurement extracts discrete, sparse natural features from 2D images such as eyes, nose, mouth and other visible structures. Stereo correspondence between features for a camera pair is determined for calculation of 3D positions. These features are also tracked over time to provide continuity for surface model fitting. Experimental results from live images are presented.

  20. Design for a high-resolution small-animal spect system usingpixellated Si(Li) detectors for in vivo Iodine-125 imaging

    SciTech Connect

    Choong, Woon-Seng; Moses, William W.; Tindall, Craig S.; Luke,Paul N.

    2004-08-01

    We propose a design for a high-resolution single-photon emission computed tomography (SPECT) system for in vivo {sup 125}I imaging in small animal using pixellated lithium-drifted silicon (Si(Li)) detectors. The proposed detectors are expected to have high interaction probability (>90%), good energy resolution (<15% FWHM), and good intrinsic spatial resolution ({approx}1 mm FWHM). The SPECT system will consist of a dual head detector geometry with the distance between the detectors ranging 30-50 mm to minimize the imaging distance between the mouse and the detectors. The detectors, each with an active area of 64 mm x 40 mm (64 x 40 array of 1 mm{sup 2} pixels and a 6 mm thick Si(Li) detector), will be mounted on a rotating gantry with an axial field-of-view of 64 mm. The detector signals will be read out by custom application-specific integrated circuits (ASICs). Using a high-resolution parallel-hole collimator, the expected spatial resolution is 1.6 mm FWHM at an imaging distance of 20 mm, and sensitivity is 6.7 cps/{micro}Ci. {sup 125}I is a readily available radioisotope with a long half-life of 59.4 days and it is commonly used to label biological compounds in molecular biology. Conventional gamma cameras are not optimized to detect the low emission energies (27 to 35 keV) of {sup 125}I. However, Si(Li) detector provides an ideal solution for detecting the low-energy emissions of {sup 125}I. In addition to presenting the design of the system, this paper presents a feasibility study of using Si(Li) detectors to detect the emissions of {sup 125}I.

  1. First Results of Small Animal Imaging Spect Detector for Cardiovascular Disease Studies on Mice

    NASA Astrophysics Data System (ADS)

    Magliozzi, M. L.; Ballerini, M.; Cisbani, E.; Colilli, S.; Cusanno, F.; Fratoni, R.; Garibaldi, F.; Giuliani, F.; Gricia, M.; Lucentini, M.; Santavenere, F.; Torrioli, S.; Veneroni, P.; Majewsky, S.; Mok, S. P. G.; Tsui, B. M. W.; Wang, Y.; Marano, G.; Musumeci, M.; Palazzesi, S.; Ciccariello, G.; de Vincentis, G.; Accorsi, R.

    2008-06-01

    We have developed a compact, open, Dual Head pinhole SPECT system for high resolution molecular imaging with radionuclides of mice, dedicated mainly to preclinical study of stem cells capability to recover myocardial infarction. The gamma detector is made of pinhole tungsten collimators, pixellated scintillators, matrix of multi-anode PMTs and individual channel readout. Measurements have been performed on phantoms and live mice devoted initially to test and calibrate the system and to optimize protocols. The implemented system and the first results will be presented, demonstrating the effectiveness of our dedicated SPECT detector for small animal imaging.

  2. A review of small animal imaging planar and pinhole spect Gamma camera imaging.

    PubMed

    Peremans, Kathelijne; Cornelissen, Bart; Van Den Bossche, Bieke; Audenaert, Kurt; Van de Wiele, Christophe

    2005-01-01

    Scintigraphy (positron emission tomography (PET) or single photon emission computed tomography (SPECT) techniques) allows qualitative and quantitative measurement of physiologic processes as well as alterations secondary to various disease states. With the use of specific radioligands, molecular pathways and pharmaco-kinetic processes can be investigated. Radioligand delivery can be (semi)quantified in the region of interest in cross-sectional and longitudinal examinations, which can be performed under the same conditions or after physiologic or pharmacologic interventions. Most preclinical pharmacokinetic studies on physiological and experimentally altered physiological processes are performed in laboratory animals using high-resolution imaging systems. Single photon emission imaging has the disadvantage of decreased spatial and temporal resolution compared with PET. The advantage of SPECT is that equipment is generally more accessible and commonly used radionuclides have a longer physical half-life allowing for investigations over a longer time interval. This review will focus on single photon emission scintigraphy. An overview of contemporary techniques to measure biodistribution and kinetics of radiopharmaceuticals in small animal in vivo is presented. Theoretical as well as practical aspects of planar gamma camera and SPECT pinhole (PH) imaging are discussed. Current research is focusing on refining PH SPECT methodology, so specific regarding technical aspects and applications of PH SPECT will be reviewed. PMID:15869162

  3. Design and performance of a multi-pinhole collimation device for small animal imaging with clinical SPECT and SPECT CT scanners

    NASA Astrophysics Data System (ADS)

    Di Filippo, Frank P.

    2008-08-01

    A multi-pinhole collimation device is developed that uses the gamma camera detectors of a clinical SPECT or SPECT-CT scanner to produce high-resolution SPECT images. The device consists of a rotating cylindrical collimator having 22 tungsten pinholes with 0.9 mm diameter apertures and an animal bed inside the collimator that moves linearly to provide helical or ordered-subsets axial sampling. CT images also may be acquired on a SPECT-CT scanner for purposes of image co-registration and SPECT attenuation correction. The device is placed on the patient table of the scanner without attaching to the detectors or scanner gantry. The system geometry is calibrated in-place from point source data and is then used during image reconstruction. The SPECT imaging performance of the device is evaluated with test phantom scans. Spatial resolution from reconstructed point source images is measured to be 0.6 mm full width at half maximum or better. Micro-Derenzo phantom images demonstrate the ability to resolve 0.7 mm diameter rod patterns. The axial slabs of a Micro-Defrise phantom are visualized well. Collimator efficiency exceeds 0.05% at the center of the field of view, and images of a uniform phantom show acceptable uniformity and minimal artifact. The overall simplicity and relatively good imaging performance of the device make it an interesting low-cost alternative to dedicated small animal scanners.

  4. Assessment of the sources of error affecting the quantitative accuracy of SPECT imaging in small animals

    PubMed Central

    Hwang, Andrew B; Franc, Benjamin L; Gullberg, Grant T; Hasegawa, Bruce H

    2009-01-01

    Small animal SPECT imaging systems have multiple potential applications in biomedical research. Whereas SPECT data are commonly interpreted qualitatively in a clinical setting, the ability to accurately quantify measurements will increase the utility of the SPECT data for laboratory measurements involving small animals. In this work, we assess the effect of photon attenuation, scatter and partial volume errors on the quantitative accuracy of small animal SPECT measurements, first with Monte Carlo simulation and then confirmed with experimental measurements. The simulations modeled the imaging geometry of a commercially available small animal SPECT system. We simulated the imaging of a radioactive source within a cylinder of water, and reconstructed the projection data using iterative reconstruction algorithms. The size of the source and the size of the surrounding cylinder were varied to evaluate the effects of photon attenuation and scatter on quantitative accuracy. We found that photon attenuation can reduce the measured concentration of radioactivity in a volume of interest in the center of a rat-sized cylinder of water by up to 50% when imaging with iodine-125, and up to 25% when imaging with technetium-99m. When imaging with iodine-125, the scatter-to-primary ratio can reach up to approximately 30%, and can cause overestimation of the radioactivity concentration when reconstructing data with attenuation correction. We varied the size of the source to evaluate partial volume errors, which we found to be a strong function of the size of the volume of interest and the spatial resolution. These errors can result in large (>50%) changes in the measured amount of radioactivity. The simulation results were compared with and found to agree with experimental measurements. The inclusion of attenuation correction in the reconstruction algorithm improved quantitative accuracy. We also found that an improvement of the spatial resolution through the use of resolution

  5. Assessment of the sources of error affecting the quantitative accuracy of SPECT imaging in small animals

    SciTech Connect

    Joint Graduate Group in Bioengineering, University of California, San Francisco and University of California, Berkeley; Department of Radiology, University of California; Gullberg, Grant T; Hwang, Andrew B.; Franc, Benjamin L.; Gullberg, Grant T.; Hasegawa, Bruce H.

    2008-02-15

    Small animal SPECT imaging systems have multiple potential applications in biomedical research. Whereas SPECT data are commonly interpreted qualitatively in a clinical setting, the ability to accurately quantify measurements will increase the utility of the SPECT data for laboratory measurements involving small animals. In this work, we assess the effect of photon attenuation, scatter and partial volume errors on the quantitative accuracy of small animal SPECT measurements, first with Monte Carlo simulation and then confirmed with experimental measurements. The simulations modeled the imaging geometry of a commercially available small animal SPECT system. We simulated the imaging of a radioactive source within a cylinder of water, and reconstructed the projection data using iterative reconstruction algorithms. The size of the source and the size of the surrounding cylinder were varied to evaluate the effects of photon attenuation and scatter on quantitative accuracy. We found that photon attenuation can reduce the measured concentration of radioactivity in a volume of interest in the center of a rat-sized cylinder of water by up to 50percent when imaging with iodine-125, and up to 25percent when imaging with technetium-99m. When imaging with iodine-125, the scatter-to-primary ratio can reach up to approximately 30percent, and can cause overestimation of the radioactivity concentration when reconstructing data with attenuation correction. We varied the size of the source to evaluate partial volume errors, which we found to be a strong function of the size of the volume of interest and the spatial resolution. These errors can result in large (>50percent) changes in the measured amount of radioactivity. The simulation results were compared with and found to agree with experimental measurements. The inclusion of attenuation correction in the reconstruction algorithm improved quantitative accuracy. We also found that an improvement of the spatial resolution through the

  6. Using the Wiener estimator to determine optimal imaging parameters in a synthetic-collimator SPECT system used for small animal imaging

    NASA Astrophysics Data System (ADS)

    Lin, Alexander; Johnson, Lindsay C.; Shokouhi, Sepideh; Peterson, Todd E.; Kupinski, Matthew A.

    2015-03-01

    In synthetic-collimator SPECT imaging, two detectors are placed at different distances behind a multi-pinhole aperture. This configuration allows for image detection at different magnifications and photon energies, resulting in higher overall sensitivity while maintaining high resolution. Image multiplexing the undesired overlapping between images due to photon origin uncertainty may occur in both detector planes and is often present in the second detector plane due to greater magnification. However, artifact-free image reconstruction is possible by combining data from both the front detector (little to no multiplexing) and the back detector (noticeable multiplexing). When the two detectors are used in tandem, spatial resolution is increased, allowing for a higher sensitivity-to-detector-area ratio. Due to variability in detector distances and pinhole spacings found in synthetic-collimator SPECT systems, a large parameter space must be examined to determine optimal imaging configurations. We chose to assess image quality based on the task of estimating activity in various regions of a mouse brain. Phantom objects were simulated using mouse brain data from the Magnetic Resonance Microimaging Neurological Atlas (MRM NeAt) and projected at different angles through models of a synthetic-collimator SPECT system, which was developed by collaborators at Vanderbilt University. Uptake in the different brain regions was modeled as being normally distributed about predetermined means and variances. We computed the performance of the Wiener estimator for the task of estimating activity in different regions of the mouse brain. Our results demonstrate the utility of the method for optimizing synthetic-collimator system design.

  7. High Sensitivity SPECT for Small Animals and Plants

    SciTech Connect

    Mitchell, Gregory S.

    2015-02-28

    Imaging systems using single gamma-ray emitting radioisotopes typically implement collimators in order to form the images. However, a tradeoff in sensitivity is inherent in the use of collimators, and modern preclinical single-photon emission computed tomography (SPECT) systems detect a very small fraction of emitted gamma-rays (<0.3%). We have built a collimator-less system, which can reach sensitivity of 40% for 99mTc imaging, while still producing images of sufficient spatial resolution for certain applications in thin objects such as mice, small plants, and well plates used for in vitro experiments.

  8. SemiSPECT: A small-animal SPECT imager based on eight cadmium zinc tellurium detector arrays

    NASA Astrophysics Data System (ADS)

    Kim, Hyunki

    We have completed a new small-animal imaging system, called SemiSPECT, based on eight pixellated cadmium zinc telluride (CdZnTe) gamma-ray detector arrays. The detector is a 2.5 cm x 2.5 cm x 0.15 cm slab having a 64 x 64 pixel array. A read-out application-specific integrated circuit (ASIC) is attached onto the detector via indium-bump bonding, and a -180 V bias is applied onto the detector surface to transport electron-hole pairs generated by gamma-ray interaction. Eight detectors are arranged in an octagonal lead-shielded ring. An eight-pinhole aperture is placed at the center of the ring, and an object is imaged onto each detector through a pinhole. The object can be rotated about a vertical axis to attain sufficient angular projections for tomographic reconstruction. The whole system gantry is compact enough to be placed onto a desktop-sized optical breadboard. Eight front-end boards were developed to detect events, generate list-mode data arrays, and send them to back-end boards. Four back-end boards are utilized to hold the list-mode data arrays and transfer them to a host computer. Eight clock-and-bias boards provide clock and bias signals to the eight ASICs. Eight control-and-bias boards were developed to monitor and control the temperatures on the eight detectors, analog and digital currents supplied to the eight ASICs, and -180 V biases applied to the eight detector surfaces. The spatial resolution provided by SemiSPECT, estimated both based on the system geometry and via the Fourier crosstalk approach, is about 1˜2 mm. The system sensitivity measured with a point source is about 1.53 x 10-4, and the estimated one from the system geometry is about 1.41 x 10-4. The energy resolution acquired by summing neighboring pixel signals in a 3 x 3 window is about 10% full-width-at-half-maximum for 140 keV gamma rays. The detectabilities for multiple signal spheres simulating various lesions or organs in a small animal are presented and discussed. A line

  9. Effect of geometric and motion tracking errors on awake small animal SPECT

    SciTech Connect

    Lee, Seung Joon; Baba, Justin S; Goddard Jr, James Samuel; Weisenberger, A G; Stolin, A; McKisson, J; Smith, M F

    2009-01-01

    A series of simulation studies were performed to evaluate the effects of geometric and motion tracking errors on reconstruction image quality for a single pinhole collimator awake animal imaging SPECT system. List-mode SPECT data generated using a custom Monte Carlo program that incorporated experimental mouse motion data were reconstructed by MLEM with Siddon's ray tracing. To better understand the impact of motion tracking and system geometric parameter errors on reconstructed system data, an offset of up to 1 mm or degree was separately applied to each for evaluation. In the absence of motion tracking or system geometric error, the applied motion compensation algorithm successfully reconstructed volumes without any degradation or distortion. Presented results reveal that motion tracking errors propagate through the SPECT reconstruction process. However, it is confirmed that the impact of tracking errors in the currently employed motion tracking system, is minimal because of their accuracy. The results also reveal the direct and indirect impact of geometric errors to motion compensated reconstruction quality and that a wrong assumption of pinhole transaxial position produces the most amount of distortion of all the investigated errors. Finally, system geometric errors are shown to have a greater impact on reconstruction quality than equivalent tracking errors.

  10. Effect of geometric and motion tracking error for awake small animal SPECT

    SciTech Connect

    S.J. Lee, J.S. Baba, J. S. Goddard, A. Stolin, J. McKisson, A.G. Weisenberger, M.F. Smith

    2010-01-01

    A series of simulation studies were performed to evaluate the effects of geometric and motion tracking errors on reconstruction image quality for a single pinhole collimator awake animal imaging SPECT system. List-mode SPECT data generated using a custom Monte Carlo program that incorporated experimental mouse motion data were reconstructed by MLEM with Siddon's ray tracing. To better understand the impact of motion tracking and system geometric parameter errors on reconstructed system data, an offset of up to 1 mm or degree was separately applied to each for evaluation. In the absence of motion tracking or system geometric error, the applied motion compensation algorithm successfully reconstructed volumes without any degradation or distortion. Presented results reveal that motion tracking errors propagate through the SPECT reconstruction process. However, it is confirmed that the impact of tracking errors in the currently employed motion tracking system, is minimal because of their accuracy. The results also reveal the direct and indirect impact of geometric errors to motion compensated reconstruction quality and that a wrong assumption of pinhole transaxial position produces the most amount of distortion of all the investigated errors. Finally, system geometric errors are shown to have a greater impact on reconstruction quality than equivalent tracking errors.

  11. Multimodal fluorescence mediated tomography and SPECT/CT for small animals imaging

    PubMed Central

    Solomon, Metasebya; Nothdruft, Ralph E.; Akers, Walter; Edwards, W. Barry; Liang, Kexian; Xu, Baogang; Suddlow, Gail P.; Deghani, Hamid; Tai, Yuan-Chuan; Eggebrecht, Adam T.; Achilefu, Samuel; Culver, Joseph P.

    2014-01-01

    Spatial and temporal co-registration of nuclear and optical images would enable the fusion of the information from theses complementary molecular imaging modalities. A critical challenge in integration is fitting optical hardware into the nuclear imaging platforms. Flexible fiber-based fluorescence mediated tomography (FMT) systems provide a viable solution because the various imaging bore sizes of small animal nuclear imaging systems can potentially accommodate the FMT fiber imaging arrays. Further, FMT imaging facilitates co-registering the nuclear and optical contrasts in time. Herein, we combine a fiber based FMT system with a preclinical NanoSPECT/CT platform. Feasibility of in vivo imaging is demonstrated by tracking the accumulation of a monomolecular multimodal imaging agent (MOMIA) in a sentinel lymph node (SLN) of a rat. Methods The fiber-based, video-rate FMT imaging system is composed of 12 alternating sources (785nm and 830nm LDs) and 13 detectors. To maintain high temporal sampling, the system simultaneously acquires ratio-metric data at each detector. The data is reconstructed using the normalized Born approach with a three-dimensional finite element model derived from an anatomical CT image of a rat for accurate light propagation modeling. Nuclear and optical contrasts are integrated by using a MOMIA. Data collection begins immediately after injection of the MOMIA intradermally into the forepaw with the FMT data acquired simultaneously with both the SPECT and CT. Results Fluorescence and radioactivity from the MOMIA were co-localized in a spatially coincident region. Intravital imaging with surgical exposure of the lymph node validated the localization of the optical contrast. The optical and nuclear contrasts where integrated by incorporating SPECT as a prior in the DOT reconstruction. Conclusion The feasibility of integrating a fiber-based, video-rate FMT system with a commercial preclinical NanoSPECT/CT platform was established. The co

  12. Improving the quality of small animal brain pinhole SPECT imaging by Bayesian reconstruction.

    PubMed

    Sohlberg, Antti; Lensu, Sanna; Jolkkonen, Jukka; Tuomisto, Leena; Ruotsalainen, Ulla; Kuikka, Jyrki T

    2004-07-01

    The possibility of using existing hardware makes pinhole single-photon emission computed tomography (SPECT) attractive when pursuing the ultra-high resolution required for small animal brain imaging. Unfortunately, the poor sensitivity and the heavy weight of the collimator hamper the use of pinhole SPECT in animal studies by generating noisy and misaligned projections. To improve the image quality we have developed a new Bayesian reconstruction method, pinhole median root prior (PH-MRP), which prevents the excessive noise accumulation from the projections to the reconstructed image. The PH-MRP algorithm was used to reconstruct data acquired with our small animal rotating device, which was designed to reduce the rotation orbit misalignments. Phantom experiments were performed to test the device and compare the PH-MRP with the conventional Feldkamp-Davis-Kress (FDK) and pinhole ordered subsets maximum likelihood expectation maximisation (PH-OSEM) reconstruction algorithms. The feasibility of the system for small animal brain imaging was studied with Han-Wistar rats injected with (123)I-epidepride and (99m)Tc-hydroxy methylene diphosphonate. Considering all the experiments, no shape distortions due to orbit misalignments were encountered and remarkable improvements in noise characteristics and also in overall image quality were observed when the PH-MRP was applied instead of the FDK or PH-OSEM. In addition, the proposed methods utilise existing hardware and require only a certain amount of construction and programming work, making them easy to implement. PMID:14991246

  13. Evaluation and reduction of respiratory motion artifacts in small animal SPECT with GATE

    NASA Astrophysics Data System (ADS)

    Lee, C.-L.; Park, S.-J.; Kim, H.-J.

    2015-09-01

    The degradation of image quality caused by respiration is a major impediment to accurate lesion detection in single photon emission computed tomography (SPECT) imaging. This study was performed to evaluate the effects of lung motion on image quantification. A small animal SPECT system with NaI(Tl) was modeled in the Geant4 application for tomographic emission (GATE) simulation for a lung lesion using a 4D mouse whole-body phantom. SPECT images were obtained using 120 projection views acquired from 0o to 360o with a 3o step. Slices were reconstructed using ordered subsets expectation maximization (OS-EM) without attenuation correction with five iterations and four subsets. Image quality was compared between the static mode without respiratory motion, and dynamic mode with respiratory motion in terms of spatial resolution was measured by the full width at half maximum (FWHM), signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR). The FWHM of the non-gated image and the respiratory gated image were also compared. Spatial resolution improved as activity increased and lesion diameter decreased in the static and dynamic modes. The SNR and CNR increased significantly as lesion activity increased and lesion diameter decreased. Our results show that respiratory motion leads to reduced contrast and quantitative accuracy and that image quantification depends on both the amplitude and the pattern of the respiratory motion. We verified that respiratory motion can have a major effect on the accuracy of measurement of lung lesions and that respiratory gating can reduce activity smearing on SPECT images.

  14. SemiSPECT: A small-animal single-photon emission computed tomography (SPECT) imager based on eight cadmium zinc telluride (CZT) detector arrays

    SciTech Connect

    Kim, Hyunki; Furenlid, Lars R.; Crawford, Michael J.; Wilson, Donald W.; Barber, H. Bradford; Peterson, Todd E.; Hunter, William C.J.; Liu Zhonglin; Woolfenden, James M.; Barrett, Harrison H.

    2006-02-15

    The first full single-photon emission computed tomography (SPECT) imager to exploit eight compact high-intrinsic-resolution cadmium zinc telluride (CZT) detectors, called SemiSPECT, has been completed. Each detector consists of a CZT crystal and a customized application-specific integrated circuit (ASIC). The CZT crystal is a 2.7 cmx2.7 cmx{approx}0.2 cm slab with a continuous top electrode and a bottom electrode patterned into a 64x64 pixel array by photolithography. The ASIC is attached to the bottom of the CZT crystal by indium-bump bonding. A bias voltage of -180 V is applied to the continuous electrode. The eight detectors are arranged in an octagonal lead-shielded ring. Each pinhole in the eight-pinhole aperture placed at the center of the ring is matched to each individual detector array. An object is imaged onto each detector through a pinhole, and each detector is operated independently with list-mode acquisition. The imaging subject can be rotated about a vertical axis to obtain additional angular projections. The performance of SemiSPECT was characterized using {sup 99m}Tc. When a 0.5 mm diameter pinhole is used, the spatial resolution on each axis is about 1.4 mm as estimated by the Fourier crosstalk matrix, which provides an algorithm-independent average resolution over the field of view. The energy resolution achieved by summing neighboring pixel signals in a 3x3 window is about 10% full-width-at-half-maximum of the photopeak. The overall system sensitivity is about 0.5x10{sup -4} with the energy window of {+-}10% from the photopeak. Line-phantom images are presented to visualize the spatial resolution provided by SemiSPECT, and images of bone, myocardium, and human tumor xenografts in mice demonstrate the feasibility of preclinical small-animal studies with SemiSPECT.

  15. SemiSPECT: a small-animal single-photon emission computed tomography (SPECT) imager based on eight cadmium zinc telluride (CZT) detector arrays.

    PubMed

    Kim, Hyunki; Furenlid, Lars R; Crawford, Michael J; Wilson, Donald W; Barber, H Bradford; Peterson, Todd E; Hunter, William C J; Liu, Zhonglin; Woolfenden, James M; Barrett, Harrison H

    2006-02-01

    The first full single-photon emission computed tomography (SPECT) imager to exploit eight compact high-intrinsic-resolution cadmium zinc telluride (CZT) detectors, called SemiSPECT, has been completed. Each detector consists of a CZT crystal and a customized application-specific integrated circuit (ASIC). The CZT crystal is a 2.7 cm x 2.7 cm x -0.2 cm slab with a continuous top electrode and a bottom electrode patterned into a 64 x 64 pixel array by photolithography. The ASIC is attached to the bottom of the CZT crystal by indium-bump bonding. A bias voltage of -180 V is applied to the continuous electrode. The eight detectors are arranged in an octagonal lead-shielded ring. Each pinhole in the eight-pinhole aperture placed at the center of the ring is matched to each individual detector array. An object is imaged onto each detector through a pinhole, and each detector is operated independently with list-mode acquisition. The imaging subject can be rotated about a vertical axis to obtain additional angular projections. The performance of SemiSPECT was characterized using 99mTc. When a 0.5 mm diameter pinhole is used, the spatial resolution on each axis is about 1.4 mm as estimated by the Fourier crosstalk matrix, which provides an algorithm-independent average resolution over the field of view. The energy resolution achieved by summing neighboring pixel signals in a 3 x 3 window is about 10% full-width-at-half-maximum of the photopeak. The overall system sensitivity is about 0.5 x 10(-4) with the energy window of +/-10% from the photopeak. Line-phantom images are presented to visualize the spatial resolution provided by SemiSPECT, and images of bone, myocardium, and human tumor xenografts in mice demonstrate the feasibility of preclinical small-animal studies with SemiSPECT. PMID:16532954

  16. SemiSPECT: A small-animal single-photon emission computed tomography (SPECT) imager based on eight cadmium zinc telluride (CZT) detector arrays

    PubMed Central

    Kim, Hyunki; Furenlid, Lars R.; Crawford, Michael J.; Wilson, Donald W.; Barber, H. Bradford; Peterson, Todd E.; Hunter, William C. J.; Liu, Zhonglin; Woolfenden, James M.; Barrett, Harrison H.

    2008-01-01

    The first full single-photon emission computed tomography (SPECT) imager to exploit eight compact high-intrinsic-resolution cadmium zinc telluride (CZT) detectors, called SemiSPECT, has been completed. Each detector consists of a CZT crystal and a customized application-specific integrated circuit (ASIC). The CZT crystal is a 2.7 cm × 2.7 cm × ~ 0.2 cm slab with a continuous top electrode and a bottom electrode patterned into a 64 × 64 pixel array by photolithography. The ASIC is attached to the bottom of the CZT crystal by indium-bump bonding. A bias voltage of −180 V is applied to the continuous electrode. The eight detectors are arranged in an octagonal lead-shielded ring. Each pinhole in the eight-pinhole aperture placed at the center of the ring is matched to each individual detector array. An object is imaged onto each detector through a pinhole, and each detector is operated independently with list-mode acquisition. The imaging subject can be rotated about a vertical axis to obtain additional angular projections. The performance of SemiSPECT was characterized using 99mTc. When a 0.5 mm diameter pinhole is used, the spatial resolution on each axis is about 1.4 mm as estimated by the Fourier crosstalk matrix, which provides an algorithm-independent average resolution over the field of view. The energy resolution achieved by summing neighboring pixel signals in a 3 × 3 window is about 10% full-width-at-half-maximum of the photopeak. The overall system sensitivity is about 0.5 × 10−4 with the energy window of ±10% from the photopeak. Line-phantom images are presented to visualize the spatial resolution provided by SemiSPECT, and images of bone, myocardium, and human tumor xenografts in mice demonstrate the feasibility of preclinical small-animal studies with SemiSPECT. PMID:16532954

  17. Design and assessment of cardiac SPECT systems

    NASA Astrophysics Data System (ADS)

    Lee, Chih-Jie

    Single-photon emission computed tomography (SPECT) is a modality widely used to detect myocardial ischemia and myocardial infarction. Objectively assessing and comparing different SPECT systems is important so that the best detectability of cardiac defects can be achieved. Whitaker, Clarkson, and Barrett's study on the scanning linear observer (SLO) shows that the SLO can be used to estimate the location and size of signals. One major advantage of the SLO is that it can be used with projection data rather than reconstruction data. Thus, this observer model assesses overall hardware performance independent by any reconstruction algorithm. In addition, we will show that the run time of image-quality studies is significantly reduced. Several systems derived from the GE CZT-based dedicated cardiac SPECT camera Discovery 530c design, which is officially named the Alcyone Technology: Discovery NM 530c, were assessed using the performance of the SLO for the task of detecting cardiac defects and estimating the properties of the defects. Clinically, hearts can be virtually segmented into three coronary artery territories: left anterior descending artery (LAD), left circumflex artery (LCX), and right coronary artery (RCA). One of the most important functions of a cardiac SPECT system is to produce images from which a radiologist can correctly predict in which territory the defect exists. A good estimation of the defect extent from the images is also very helpful for determining the seriousness of the myocardial ischemia. In this dissertation, both locations and extent of defects were estimated by the SLO, and system performance was assessed using localization receiver operating characteristic (LROC) / estimation receiver operating characteristic (EROC) curves. Area under LROC curve (AULC) / area under EROC curve (AUEC) and true positive fraction (TPF) at specific false positive fraction (FPF) can be treated as the gures of merit (FOMs). As the results will show, a

  18. Performance evaluation of D-SPECT: a novel SPECT system for nuclear cardiology

    NASA Astrophysics Data System (ADS)

    Erlandsson, Kjell; Kacperski, Krzysztof; van Gramberg, Dean; Hutton, Brian F.

    2009-05-01

    D-SPECT (Spectrum Dynamics, Israel) is a novel SPECT system for cardiac perfusion studies. Based on CZT detectors, region-centric scanning, high-sensitivity collimators and resolution recovery, it offers potential advantages over conventional systems. A series of measurements were made on a β-version D-SPECT system in order to evaluate its performance in terms of energy resolution, scatter fraction, sensitivity, count rate capability and resolution. Corresponding measurements were also done on a conventional SPECT system (CS) for comparison. The energy resolution of the D-SPECT system at 140 keV was 5.5% (CS: 9.25%), the scatter fraction 30% (CS: 34%), the planar sensitivity 398 s-1 MBq-1 per head (99mTc, 10 cm) (CS: 72 s-1 MBq-1), and the tomographic sensitivity in the heart region was in the range 647-1107 s-1 MBq-1 (CS: 141 s-1 MBq-1). The count rate increased linearly with increasing activity up to 1.44 M s-1. The intrinsic resolution was equal to the pixel size, 2.46 mm (CS: 3.8 mm). The average reconstructed resolution using the standard clinical filter was 12.5 mm (CS: 13.7 mm). The D-SPECT has superior sensitivity to that of a conventional system with similar spatial resolution. It also has excellent energy resolution and count rate characteristics, which should prove useful in dynamic and dual radionuclide studies.

  19. Experimental Acquisitions with ^125I on a Small Animal SPECT Device*

    NASA Astrophysics Data System (ADS)

    Knott, Kevin; Welsh, Robert E.; Bradley, Eric L.; Saha, Margaret S.; Kross, Brian; Majewski, Stan; Popov, Vladimir; Smith, Mark F.; Weisenberger, Andrew G.; Wojcik, Randolph

    2001-04-01

    We have performed single photon emission computed tomography (SPECT) studies on a small animal scanning system for which the detector employed position sensitive phototubes (125 mm dia. Hamamatsu R3292 and 18 x 18 mm Hamamatsu M-64) coupled to pixelated scintillators CsI(Tl) and CsI(Na) Phantom acquisitions were used to investigate the effects of angular sampling and scan time on reconstructed image quality and noise. Results from these studies will be described and extended to in vivo studies with small animals. *Supported in part by the Thomas F. and Kate Miller Jeffress Trust, the Department of Energy, The American Diabetes Association, The National Science Foundation, the Howard Hughes Foundation and the Virginia Commonwealth Health Research Board.

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

    NASA Astrophysics Data System (ADS)

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

    2014-03-01

    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.

  1. Optimal energy window selection of a CZT-based small-animal SPECT for quantitative accuracy

    NASA Astrophysics Data System (ADS)

    Park, Su-Jin; Yu, A. Ram; Choi, Yun Young; Kim, Kyeong Min; Kim, Hee-Joung

    2015-05-01

    Cadmium zinc telluride (CZT)-based small-animal single-photon emission computed tomography (SPECT) has desirable characteristics such as superior energy resolution, but data acquisition for SPECT imaging has been widely performed with a conventional energy window. The aim of this study was to determine the optimal energy window settings for technetium-99 m (99mTc) and thallium-201 (201Tl), the most commonly used isotopes in SPECT imaging, using CZT-based small-animal SPECT for quantitative accuracy. We experimentally investigated quantitative measurements with respect to primary count rate, contrast-to-noise ratio (CNR), and scatter fraction (SF) within various energy window settings using Triumph X-SPECT. The two ways of energy window settings were considered: an on-peak window and an off-peak window. In the on-peak window setting, energy centers were set on the photopeaks. In the off-peak window setting, the ratios of energy differences between the photopeak from the lower- and higher-threshold varied from 4:6 to 3:7. In addition, the energy-window width for 99mTc varied from 5% to 20%, and that for 201Tl varied from 10% to 30%. The results of this study enabled us to determine the optimal energy windows for each isotope in terms of primary count rate, CNR, and SF. We selected the optimal energy window that increases the primary count rate and CNR while decreasing SF. For 99mTc SPECT imaging, the energy window of 138-145 keV with a 5% width and off-peak ratio of 3:7 was determined to be the optimal energy window. For 201Tl SPECT imaging, the energy window of 64-85 keV with a 30% width and off-peak ratio of 3:7 was selected as the optimal energy window. Our results demonstrated that the proper energy window should be carefully chosen based on quantitative measurements in order to take advantage of desirable characteristics of CZT-based small-animal SPECT. These results provided valuable reference information for the establishment of new protocol for CZT

  2. Development of an MR-compatible SPECT system (MRSPECT) for simultaneous data acquisition

    NASA Astrophysics Data System (ADS)

    Hamamura, Mark J.; Ha, Seunghoon; Roeck, Werner W.; Tugan Muftuler, L.; Wagenaar, Douglas J.; Meier, Dirk; Patt, Bradley E.; Nalcioglu, Orhan

    2010-03-01

    In medical imaging, single-photon emission computed tomography (SPECT) can provide specific functional information while magnetic resonance imaging (MRI) can provide high spatial resolution anatomical information as well as complementary functional information. In this study, we developed a miniaturized dual-modality SPECT/MRI (MRSPECT) system and demonstrated the feasibility of simultaneous SPECT and MRI data acquisition, with the possibility of whole-body MRSPECT systems through suitable scaling of components. For our MRSPECT system, a cadmium-zinc-telluride (CZT) nuclear radiation detector was interfaced with a specialized radiofrequency (RF) coil and placed within a whole-body 4 T MRI system. Various phantom experiments characterized the interaction between the SPECT and MRI hardware components. The metallic components of the SPECT hardware altered the B0 field and generated a non-uniform reduction in the signal-to-noise ratio (SNR) of the MR images. The presence of a magnetic field generated a position shift and resolution loss in the nuclear projection data. Various techniques were proposed to compensate for these adverse effects. Overall, our results demonstrate that accurate, simultaneous SPECT and MRI data acquisition is feasible, justifying the further development of MRSPECT for either small-animal imaging or whole-body human systems by using appropriate components.

  3. Attenuation correction for small animal SPECT imaging using x-ray CT data

    SciTech Connect

    Hwang, Andrew B.; Hasegawa, Bruce H.

    2005-09-15

    Photon attenuation in small animal nuclear medicine scans can be significant when using isotopes that emit lower energy photons such as iodine-125. We have developed a method to use microCT data to perform attenuation corrected small animal single-photon emission computed tomography (SPECT). A microCT calibration phantom was first imaged, and the resulting calibration curve was used to convert microCT image values to linear attenuation coefficient values that were then used in an iterative SPECT reconstruction algorithm. This method was applied to reconstruct a SPECT image of a uniform phantom filled with {sup 125}I-NaI. Without attenuation correction, the image suffered a 30% decrease in intensity in the center of the image, which was removed with the addition of attenuation correction. This reduced the relative standard deviation in the region of interest from 10% to 6%.

  4. Adaptive SPECT

    PubMed Central

    Barrett, Harrison H.; Furenlid, Lars R.; Freed, Melanie; Hesterman, Jacob Y.; Kupinski, Matthew A.; Clarkson, Eric; Whitaker, Meredith K.

    2008-01-01

    Adaptive imaging systems alter their data-acquisition configuration or protocol in response to the image information received. An adaptive pinhole single-photon emission computed tomography (SPECT) system might acquire an initial scout image to obtain preliminary information about the radiotracer distribution and then adjust the configuration or sizes of the pinholes, the magnifications, or the projection angles in order to improve performance. This paper briefly describes two small-animal SPECT systems that allow this flexibility and then presents a framework for evaluating adaptive systems in general, and adaptive SPECT systems in particular. The evaluation is in terms of the performance of linear observers on detection or estimation tasks. Expressions are derived for the ideal linear (Hotelling) observer and the ideal linear (Wiener) estimator with adaptive imaging. Detailed expressions for the performance figures of merit are given, and possible adaptation rules are discussed. PMID:18541485

  5. Performance evaluation of advanced industrial SPECT system with diverging collimator.

    PubMed

    Park, Jang Guen; Jung, Sung-Hee; Kim, Jong Bum; Moon, Jinho; Yeom, Yeon Soo; Kim, Chan Hyeong

    2014-12-01

    An advanced industrial SPECT system with 12-fold-array diverging collimator was developed for flow visualization in industrial reactors and was discussed in the previous study. The present paper describes performance evaluation of the SPECT system under both static- and dynamic- flow conditions. Under static conditions, the movement of radiotracer inside the test reactor was compared with that of color tracer (blue ink) captured with a high-speed camera. The comparison of the reconstructed images obtained with the radiotracer and the SPECT system showed fairly good agreement with video-frames of the color tracer obtained with the camera. Based on the results of the performance evaluation, it is concluded that the SPECT system is suitable for investigation and visualization of flows in industrial flow reactors. PMID:25169132

  6. Thick Silicon Double-Sided Strip Detectors for Low-Energy Small-Animal SPECT

    PubMed Central

    Shokouhi, Sepideh; McDonald, Benjamin S.; Durko, Heather L.; Fritz, Mark A.; Furenlid, Lars R.; Peterson, Todd E.

    2010-01-01

    This work presents characterization studies of thick silicon double-sided strip detectors for a high-resolution small-animal SPECT. The dimension of these detectors is 60.4 mm × 60.4 mm × 1 mm. There are 1024 strips on each side that give the coordinates of the photon interaction, with each strip processed by a separate ASIC channel. Our measurement shows that intrinsic spatial resolution equivalent to the 59 μm strip pitch is attainable. Good trigger uniformity can be achieved by proper setting of a 4-bit DAC in each ASIC channel to remove trigger threshold variations. This is particularly important for triggering at low energies. The thick silicon DSSD (Double-sided strip detector) shows high potential for small-animal SPECT. PMID:20686626

  7. Characterization of a high-purity germanium detector for small-animal SPECT

    PubMed Central

    Johnson, Lindsay C; Campbell, Desmond L; Hull, Ethan L; Peterson, Todd E

    2011-01-01

    We present an initial evaluation of a mechanically-cooled, high-purity germanium double-sided strip detector as a potential gamma camera for small-animal SPECT. It is 90 mm in diameter and 10 mm thick with two sets of 16 orthogonal strips that have a 4.5 mm width with a 5 mm pitch. We found an energy resolution of 0.96% at 140 keV, an intrinsic efficiency of 43.3% at 122 keV and a FWHM spatial resolution of approximately 1.5 mm. We demonstrated depth-of-interaction estimation capability through comparison of pinhole acquisitions with a point source on and off axis. Finally, a flood-corrected-flood image exhibited a strip-level uniformity of less than 1%. This high-purity germanium offers many desirable properties for small-animal SPECT. PMID:21852723

  8. Performance Evaluation of a Bedside Cardiac SPECT System

    SciTech Connect

    M.T. Studenski, D.R. Gilland, J.G. Parker, B. Hammond, S. Majewski, A.G. Weisenberger, V. Popov

    2009-06-01

    This paper reports on the initial performance evaluation of a bedside cardiac PET/SPECT system. The system was designed to move within a hospital to image critically-ill patients, for example, those in intensive care unit (ICU) or emergency room settings, who cannot easily be transported to a conventional SPECT or PET facility. The system uses two compact (25 cm times 25 cm) detectors with pixilated NaI crystals and position sensitive PMTs. The performance is evaluated for both 140 keV (Tc-99m) and 511 keV (F-18) emitters with the system operating in single photon counting (SPECT) mode. The imaging performance metrics for both 140 keV and 511 keV included intrinsic energy resolution, spatial resolution (intrinsic, system, and reconstructed SPECT), detection sensitivity, count rate capability, and uniformity. Results demonstrated an intrinsic energy resolution of 31% at 140 keV and 23% at 511 keV, a planar intrinsic spatial resolution of 5.6 mm full width half-maximum (FWHM) at 140 keV and 6.3 mm FWHM at 511 keV, and a sensitivity of 4.15 countsmiddotmuCi-1 ldr s-1 at 140 keV and 0.67 counts ldr muCi-1 ldr s-1 at 511 keV. To further the study, a SPECT acquisition using a dynamic cardiac phantom was performed, and the resulting reconstructed images are presented.

  9. Dual modality micro-SPECT and micro-CT for small animal imaging: technical advances and challenges

    NASA Astrophysics Data System (ADS)

    Izaguirre, Enrique W.; Sun, Mingshan; Carver, James; Thompson, Steve; Hasegawa, Bruce H.

    2005-09-01

    Small animal dual modality microSPECT-micro CT has seen many technological advances during recent years. The design of small animal dual modality scanners is a multidisciplinary field, where several interrelated technological problems must be integrated in a complex instrument. This article describes the general concepts that must be taken into consideration during the design process of dual modality microSPECT- microCT scanners. A description of the contemporary scanner technology is presented using the recently designed dual modality micro SPECT -microCT at the Physics Research Laboratory at UCSF. The technology is described with a simple approach to introduce the reader to the complex process of the dual modality scanner design. This article includes a discussion of current technological challenges that have potential to improve or expand the microSPECT-microCT performance and its applications.

  10. System Integration of FastSPECT III, a Dedicated SPECT Rodent-Brain Imager Based on BazookaSPECT Detector Technology

    PubMed Central

    Miller, Brian W.; Furenlid, Lars R.; Moore, Stephen K.; Barber, H. Bradford; Nagarkar, Vivek V.; Barrett, Harrison H.

    2010-01-01

    FastSPECT III is a stationary, single-photon emission computed tomography (SPECT) imager designed specifically for imaging and studying neurological pathologies in rodent brain, including Alzheimer’s and Parkinsons’s disease. Twenty independent BazookaSPECT [1] gamma-ray detectors acquire projections of a spherical field of view with pinholes selected for desired resolution and sensitivity. Each BazookaSPECT detector comprises a columnar CsI(Tl) scintillator, image-intensifier, optical lens, and fast-frame-rate CCD camera. Data stream back to processing computers via firewire interfaces, and heavy use of graphics processing units (GPUs) ensures that each frame of data is processed in real time to extract the images of individual gamma-ray events. Details of the system design, imaging aperture fabrication methods, and preliminary projection images are presented. PMID:21218137

  11. Multimodal imaging with hybrid semiconductor detectors Timepix for an experimental MRI-SPECT system

    NASA Astrophysics Data System (ADS)

    Zajicek, J.; Jakubek, J.; Burian, M.; Vobecky, M.; Fauler, A.; Fiederle, M.; Zwerger, A.

    2013-01-01

    An increasing number of clinical applications are being based on multimodal imaging systems (MIS), including anatomical (CT, MRI) and functional (PET, SPECT) techniques to provide complex information in a single image. CT with one of the scintigraphic methods (PET or SPECT) is nowadays a combination of choice for clinical practice and it is mostly used in cardiography and tumour diagnostics. Combination with MRI is also being implemented as no radiation dose is imparted to the patient and it is possible to gain higher structural resolution of soft tissues (brain imaging). A major disadvantage of such systems is inability to operate scintillators with photomultipliers (used for detection of γ rays) in presence of high magnetic fields. In this work we present the application of the semiconductor pixel detector for SPECT method in combination with MR imaging. We propose a novel approach based on MRI compatible setup with CdTe pixel sensor Timepix and non-conductive collimator. Measurements were performed on high proton-density (PD) phantom (1H) with an embedded radioisotopic source inside the shielded RF coil by MRI animal scanner (4.7 T). Our results pave the way for a combined MRI-SPECT system. The project was performed in the framework of the Medipix Collaboration.

  12. Phantom experiments on a PSAPD-based compact gamma camera with submillimeter spatial resolution for small animal SPECT

    PubMed Central

    Kim, Sangtaek; McClish, Mickel; Alhassen, Fares; Seo, Youngho; Shah, Kanai S.; Gould, Robert G.

    2010-01-01

    We demonstrate a position sensitive avalanche photodiode (PSAPD) based compact gamma camera for the application of small animal single photon emission computed tomography (SPECT). The silicon PSAPD with a two-dimensional resistive layer and four readout channels is implemented as a gamma ray detector to record the energy and position of radiation events from a radionuclide source. A 2 mm thick monolithic CsI:Tl scintillator is optically coupled to a PSAPD with a 8mm×8mm active area, providing submillimeter intrinsic spatial resolution, high energy resolution (16% full-width half maximum at 140 keV) and high gain. A mouse heart phantom filled with an aqueous solution of 370 MBq 99mTc-pertechnetate (140 keV) was imaged using the PSAPD detector module and a tungsten knife-edge pinhole collimator with a 0.5 mm diameter aperture. The PSAPD detector module was cooled with cold nitrogen gas to suppress dark current shot noise. For each projection image of the mouse heart phantom, a rotated diagonal readout algorithm was used to calculate the position of radiation events and correct for pincushion distortion. The reconstructed image of the mouse heart phantom demonstrated reproducible image quality with submillimeter spatial resolution (0.7 mm), showing the feasibility of using the compact PSAPD-based gamma camera for a small animal SPECT system. PMID:21278833

  13. Dynamics of intramyocardial blood volume in the intact animal: evaluation with SPECT

    NASA Astrophysics Data System (ADS)

    Behrenbeck, Thomas; O'Connor, Michael K.; Foley, David A.; Ritman, Erik L.

    1996-04-01

    Variations in blood volume in the myocardium through the cardiac cycle have previously been considered constant. More recent studies have indicated a considerably variation from end diastole to end systole. These studies were nearly all performed under non-physiological conditions using muscle preparations or ex situ cardiac preparations. This study was designed to assess the dynamic changes of the intramyocardial blood volume in the intact animal under normal flow conditions using single photon emission computed tomography (SPECT). Radiolabeled, 15 micrometers diameter, microspheres were emoblized in the myocardial microcirculation of dogs with subsequent scans in a TRIAD single-photon-emission-computed- tomography scanner. Gated images were obtained at 63 msec intervals encompassing the entire heart. Transmural voxel (equals volume element) brightness was measured in all tomographic images reflecting global and regional count density in the myocardium. There was a significant decrease in the blood volume from end diastole to end systole (10.8 cc/100 mL muscle volume; p < 0.00001). The decrease from diastole (ED) to systole (ES) in image brightness at the apex, mid ventricle, and base were: -5.7% (p < 0.01, apex vs. base), -4.7% (p < 0.01, mid ventricle vs. base) and +2.2%, respectively. Conclusions: (1) respiratory and ECG gated SPECT images allow measurement of intramyocardial blood volume changes throughout the cardiac cycle in the intact animal; (2) myocardial blood content is maximum at ED; (3) these findings progressively diminished in magnitude from apex to base.

  14. Recent advances in cardiac SPECT instrumentation and system design.

    PubMed

    Smith, Mark F

    2013-08-01

    Recent advances in clinical cardiac SPECT instrumentation are reviewed from a systems perspective. New hardware technologies include pixelated scintillator and semiconductor detector elements; photodetectors such as position-sensitive photomultiplier tubes (PSPMT), avalanche photodiodes (APD) and silicon photomultipliers (SiPM); and novel cardiac collimation methods. There are new approaches for positioning detectors and controlling their motion during cardiac imaging. Software technology advances include iterative image reconstruction with modeling of Poisson statistics and depth-dependent collimator response. These new technologies enable faster acquisitions, the lowering of administered activity and radiation dose, and improved image resolution. Higher sensitivity collimators are a significant factor enabling faster acquisitions. Several clinical systems incorporating new technologies are discussed and different system designs can achieve similar performance. With detector elements such as APDs, SiPMs and semiconductors that are insensitive to magnetic fields, the potential for cardiac SPECT imagers that are MRI compatible opens up new frontiers in clinical cardiac research and patient care. PMID:23832650

  15. Quantitative multi-pinhole small-animal SPECT: uniform versus non-uniform Chang attenuation correction

    NASA Astrophysics Data System (ADS)

    Wu, C.; de Jong, J. R.; Gratama van Andel, H. A.; van der Have, F.; Vastenhouw, B.; Laverman, P.; Boerman, O. C.; Dierckx, R. A. J. O.; Beekman, F. J.

    2011-09-01

    Attenuation of photon flux on trajectories between the source and pinhole apertures affects the quantitative accuracy of reconstructed single-photon emission computed tomography (SPECT) images. We propose a Chang-based non-uniform attenuation correction (NUA-CT) for small-animal SPECT/CT with focusing pinhole collimation, and compare the quantitative accuracy with uniform Chang correction based on (i) body outlines extracted from x-ray CT (UA-CT) and (ii) on hand drawn body contours on the images obtained with three integrated optical cameras (UA-BC). Measurements in phantoms and rats containing known activities of isotopes were conducted for evaluation. In 125I, 201Tl, 99mTc and 111In phantom experiments, average relative errors comparing to the gold standards measured in a dose calibrator were reduced to 5.5%, 6.8%, 4.9% and 2.8%, respectively, with NUA-CT. In animal studies, these errors were 2.1%, 3.3%, 2.0% and 2.0%, respectively. Differences in accuracy on average between results of NUA-CT, UA-CT and UA-BC were less than 2.3% in phantom studies and 3.1% in animal studies except for 125I (3.6% and 5.1%, respectively). All methods tested provide reasonable attenuation correction and result in high quantitative accuracy. NUA-CT shows superior accuracy except for 125I, where other factors may have more impact on the quantitative accuracy than the selected attenuation correction.

  16. Lutetium oxyorthosilicate (LSO) intrinsic activity correction and minimal detectable target activity study for SPECT imaging with a LSO-based animal PET scanner.

    PubMed

    Yao, Rutao; Ma, Tianyu; Shao, Yiping

    2008-08-21

    This work is part of a feasibility study to develop SPECT imaging capability on a lutetium oxyorthosilicate (LSO) based animal PET system. The SPECT acquisition was enabled by inserting a collimator assembly inside the detector ring and acquiring data in singles mode. The same LSO detectors were used for both PET and SPECT imaging. The intrinsic radioactivity of (176)Lu in the LSO crystals, however, contaminates the SPECT data, and can generate image artifacts and introduce quantification error. The objectives of this study were to evaluate the effectiveness of a LSO background subtraction method, and to estimate the minimal detectable target activity (MDTA) of image object for SPECT imaging. For LSO background correction, the LSO contribution in an image study was estimated based on a pre-measured long LSO background scan and subtracted prior to the image reconstruction. The MDTA was estimated in two ways. The empirical MDTA (eMDTA) was estimated from screening the tomographic images at different activity levels. The calculated MDTA (cMDTA) was estimated from using a formula based on applying a modified Currie equation on an average projection dataset. Two simulated and two experimental phantoms with different object activity distributions and levels were used in this study. The results showed that LSO background adds concentric ring artifacts to the reconstructed image, and the simple subtraction method can effectively remove these artifacts-the effect of the correction was more visible when the object activity level was near or above the eMDTA. For the four phantoms studied, the cMDTA was consistently about five times of the corresponding eMDTA. In summary, we implemented a simple LSO background subtraction method and demonstrated its effectiveness. The projection-based calculation formula yielded MDTA results that closely correlate with that obtained empirically and may have predicative value for imaging applications. PMID:18670052

  17. Lutetium oxyorthosilicate (LSO) intrinsic activity correction and minimal detectable target activity study for SPECT imaging with a LSO-based animal PET scanner

    NASA Astrophysics Data System (ADS)

    Yao, Rutao; Ma, Tianyu; Shao, Yiping

    2008-08-01

    This work is part of a feasibility study to develop SPECT imaging capability on a lutetium oxyorthosilicate (LSO) based animal PET system. The SPECT acquisition was enabled by inserting a collimator assembly inside the detector ring and acquiring data in singles mode. The same LSO detectors were used for both PET and SPECT imaging. The intrinsic radioactivity of 176Lu in the LSO crystals, however, contaminates the SPECT data, and can generate image artifacts and introduce quantification error. The objectives of this study were to evaluate the effectiveness of a LSO background subtraction method, and to estimate the minimal detectable target activity (MDTA) of image object for SPECT imaging. For LSO background correction, the LSO contribution in an image study was estimated based on a pre-measured long LSO background scan and subtracted prior to the image reconstruction. The MDTA was estimated in two ways. The empirical MDTA (eMDTA) was estimated from screening the tomographic images at different activity levels. The calculated MDTA (cMDTA) was estimated from using a formula based on applying a modified Currie equation on an average projection dataset. Two simulated and two experimental phantoms with different object activity distributions and levels were used in this study. The results showed that LSO background adds concentric ring artifacts to the reconstructed image, and the simple subtraction method can effectively remove these artifacts—the effect of the correction was more visible when the object activity level was near or above the eMDTA. For the four phantoms studied, the cMDTA was consistently about five times of the corresponding eMDTA. In summary, we implemented a simple LSO background subtraction method and demonstrated its effectiveness. The projection-based calculation formula yielded MDTA results that closely correlate with that obtained empirically and may have predicative value for imaging applications.

  18. Preliminary experience with small animal SPECT imaging on clinical gamma cameras.

    PubMed

    Aguiar, P; Silva-Rodríguez, J; Herranz, M; Ruibal, A

    2014-01-01

    The traditional lack of techniques suitable for in vivo imaging has induced a great interest in molecular imaging for preclinical research. Nevertheless, its use spreads slowly due to the difficulties in justifying the high cost of the current dedicated preclinical scanners. An alternative for lowering the costs is to repurpose old clinical gamma cameras to be used for preclinical imaging. In this paper we assess the performance of a portable device, that is, working coupled to a single-head clinical gamma camera, and we present our preliminary experience in several small animal applications. Our findings, based on phantom experiments and animal studies, provided an image quality, in terms of contrast-noise trade-off, comparable to dedicated preclinical pinhole-based scanners. We feel that our portable device offers an opportunity for recycling the widespread availability of clinical gamma cameras in nuclear medicine departments to be used in small animal SPECT imaging and we hope that it can contribute to spreading the use of preclinical imaging within institutions on tight budgets. PMID:24963478

  19. Prone breast tumor imaging using vertical axis-of-rotation (VAOR) SPECT systems: An initial study

    SciTech Connect

    Wang, Huili; Scarfone, C.; Greer, K.L.; Coleman, R.E.

    1996-12-31

    We propose the use of a single photon emission computed tomography (SPECT) system equipped with multiple cameras revolving around a vertical axis-of-rotation (VAOR) to image tumors in a prone-dependent breast. This innovative breast imaging approach has the advantages of a small attenuation volume between breast lesions and gamma detector as well as a minimal radius-of-rotation compared to conventional (horizontal axis-of-rotation) breast SPECT. Small attenuation volume results in improved detected counts and minimal radius-of-rotation leads to increased collimator resolution. Because of no VAOR SPECT system currently available, we conducted our experiments on a conventional SPECT system using an isolated breast phantom to investigate the proposed VAOR breast SPECT. Our experimental setup simulated a VAOR SPECT study with a prone-dependent breast in the camera`s field-of-view. The results of our experiment indicate that VAOR breast SPECT with Trionix LESR parallel hole collimator is capable of detecting a breast lesion with a diameter of 10 mm and a lesion-to-background concentration ratio of 6 to 1. The results also demonstrate that VAOR breast SPECT provides improved lesion visualization over planar scintimammography and conventional breast SPECT.

  20. Advances in Small Animal Imaging Systems

    NASA Astrophysics Data System (ADS)

    Loudos, George K.

    2007-11-01

    The rapid growth in genetics and molecular biology combined with the development of techniques for genetically engineering small animals has led to an increased interest in in vivo laboratory animal imaging during the past few years. For this purpose, new instrumentation, data acquisition strategies, and image processing and reconstruction techniques are being developed, researched and evaluated. The aim of this article is to give a short overview of the state of the art technologies for high resolution and high sensitivity molecular imaging techniques, primarily positron emission tomography (PET) and single photon emission computed tomography (SPECT). The basic needs of small animal imaging will be described. The evolution in instrumentation in the past two decades, as well as the commercially available systems will be overviewed. Finally, the new trends in detector technology and preliminary results from challenging applications will be presented. For more details a number of references are provided.

  1. Advances in Small Animal Imaging Systems

    SciTech Connect

    Loudos, George K.

    2007-11-26

    The rapid growth in genetics and molecular biology combined with the development of techniques for genetically engineering small animals has led to an increased interest in in vivo laboratory animal imaging during the past few years. For this purpose, new instrumentation, data acquisition strategies, and image processing and reconstruction techniques are being developed, researched and evaluated. The aim of this article is to give a short overview of the state of the art technologies for high resolution and high sensitivity molecular imaging techniques, primarily positron emission tomography (PET) and single photon emission computed tomography (SPECT). The basic needs of small animal imaging will be described. The evolution in instrumentation in the past two decades, as well as the commercially available systems will be overviewed. Finally, the new trends in detector technology and preliminary results from challenging applications will be presented. For more details a number of references are provided.

  2. Impact of extraneous mispositioned events on motion-corrected brain SPECT images of freely moving animals

    SciTech Connect

    Angelis, Georgios I. Ryder, William J.; Bashar, Rezaul; Meikle, Steven R.; Fulton, Roger R.

    2014-09-15

    Purpose: Single photon emission computed tomography (SPECT) brain imaging of freely moving small animals would allow a wide range of important neurological processes and behaviors to be studied, which are normally inhibited by anesthetic drugs or precluded due to the animal being restrained. While rigid body motion of the head can be tracked and accounted for in the reconstruction, activity in the torso may confound brain measurements, especially since motion of the torso is more complex (i.e., nonrigid) and not well correlated with that of the head. The authors investigated the impact of mispositioned events and attenuation due to the torso on the accuracy of motion corrected brain images of freely moving mice. Methods: Monte Carlo simulations of a realistic voxelized mouse phantom and a dual compartment phantom were performed. Each phantom comprised a target and an extraneous compartment which were able to move independently of each other. Motion correction was performed based on the known motion of the target compartment only. Two SPECT camera geometries were investigated: a rotating single head detector and a stationary full ring detector. The effects of motion, detector geometry, and energy of the emitted photons (hence, attenuation) on bias and noise in reconstructed brain regions were evaluated. Results: The authors observed two main sources of bias: (a) motion-related inconsistencies in the projection data and (b) the mismatch between attenuation and emission. Both effects are caused by the assumption that the orientation of the torso is difficult to track and model, and therefore cannot be conveniently corrected for. The motion induced bias in some regions was up to 12% when no attenuation effects were considered, while it reached 40% when also combined with attenuation related inconsistencies. The detector geometry (i.e., rotating vs full ring) has a big impact on the accuracy of the reconstructed images, with the full ring detector being more

  3. Radiotracers for PET and SPECT studies of neurotransmitter systems

    SciTech Connect

    Fowler, J.S.

    1991-01-01

    The study of neurotransmitter systems is one of the major thrusts in emission tomography today. The current generation of Positron Emission Tomography (PET) and Single Photon Emission Computed Tomography (SPECT) radiotracers examines neurotransmitter properties from a number of different perspectives including their pre and post synaptic sites and the activity of the enzymes which regulate their concentration. Although the dopamine system has been the most extensively investigated, other neurotransmitter systems including the acetylcholine muscarine, serotonin, benzodiazepine, opiate, NMDA and others are also under intensive development. Enzymes involved in the synthesis and regulation of neurotransmitter concentration, for example monoamine oxidase and amino acid decarboxylase has also been probed in vivo. Medical applications range from the study of normal function and the characterization of neurotransmitter activity in neurological and psychiatric diseases and in heart disease and cancer to the study of the binding of therapeutic drugs and substances of abuse. This chapter will provide an overview of the current generation of radiotracers for PET and SPECT studies of neurotransmitter systems including radiotracer design, synthesis localization mechanisms and applications in emission tomography. 60 refs., 1 tab.

  4. Automatic estimation of detector radial position for contoured SPECT acquisition using CT images on a SPECT/CT system.

    PubMed

    Liu, Ruijie Rachel; Erwin, William D

    2006-08-01

    An algorithm was developed to estimate noncircular orbit (NCO) single-photon emission computed tomography (SPECT) detector radius on a SPECT/CT imaging system using the CT images, for incorporation into collimator resolution modeling for iterative SPECT reconstruction. Simulated male abdominal (arms up), male head and neck (arms down) and female chest (arms down) anthropomorphic phantom, and ten patient, medium-energy SPECT/CT scans were acquired on a hybrid imaging system. The algorithm simulated inward SPECT detector radial motion and object contour detection at each projection angle, employing the calculated average CT image and a fixed Hounsfield unit (HU) threshold. Calculated radii were compared to the observed true radii, and optimal CT threshold values, corresponding to patient bed and clothing surfaces, were found to be between -970 and -950 HU. The algorithm was constrained by the 45 cm CT field-of-view (FOV), which limited the detected radii to < or = 22.5 cm and led to occasional radius underestimation in the case of object truncation by CT. Two methods incorporating the algorithm were implemented: physical model (PM) and best fit (BF). The PM method computed an offset that produced maximum overlap of calculated and true radii for the phantom scans, and applied that offset as a calculated-to-true radius transformation. For the BF method, the calculated-to-true radius transformation was based upon a linear regression between calculated and true radii. For the PM method, a fixed offset of +2.75 cm provided maximum calculated-to-true radius overlap for the phantom study, which accounted for the camera system's object contour detect sensor surface-to-detector face distance. For the BF method, a linear regression of true versus calculated radius from a reference patient scan was used as a calculated-to-true radius transform. Both methods were applied to ten patient scans. For -970 and -950 HU thresholds, the combined overall average root-mean-square (rms

  5. Automatic estimation of detector radial position for contoured SPECT acquisition using CT images on a SPECT/CT system

    SciTech Connect

    Liu Ruijie Rachel; Erwin, William D.

    2006-08-15

    An algorithm was developed to estimate noncircular orbit (NCO) single-photon emission computed tomography (SPECT) detector radius on a SPECT/CT imaging system using the CT images, for incorporation into collimator resolution modeling for iterative SPECT reconstruction. Simulated male abdominal (arms up), male head and neck (arms down) and female chest (arms down) anthropomorphic phantom, and ten patient, medium-energy SPECT/CT scans were acquired on a hybrid imaging system. The algorithm simulated inward SPECT detector radial motion and object contour detection at each projection angle, employing the calculated average CT image and a fixed Hounsfield unit (HU) threshold. Calculated radii were compared to the observed true radii, and optimal CT threshold values, corresponding to patient bed and clothing surfaces, were found to be between -970 and -950 HU. The algorithm was constrained by the 45 cm CT field-of-view (FOV), which limited the detected radii to {<=}22.5 cm and led to occasional radius underestimation in the case of object truncation by CT. Two methods incorporating the algorithm were implemented: physical model (PM) and best fit (BF). The PM method computed an offset that produced maximum overlap of calculated and true radii for the phantom scans, and applied that offset as a calculated-to-true radius transformation. For the BF method, the calculated-to-true radius transformation was based upon a linear regression between calculated and true radii. For the PM method, a fixed offset of +2.75 cm provided maximum calculated-to-true radius overlap for the phantom study, which accounted for the camera system's object contour detect sensor surface-to-detector face distance. For the BF method, a linear regression of true versus calculated radius from a reference patient scan was used as a calculated-to-true radius transform. Both methods were applied to ten patient scans. For -970 and -950 HU thresholds, the combined overall average root-mean-square (rms) error

  6. Observer detection limits for a dedicated SPECT breast imaging system

    NASA Astrophysics Data System (ADS)

    Cutler, S. J.; Perez, K. L.; Barnhart, H. X.; Tornai, M. P.

    2010-04-01

    An observer-based contrast-detail study is performed in an effort to evaluate the limits of object detectability using a dedicated CZT-based breast SPECT imaging system under various imaging conditions. A custom geometric contrast-resolution phantom was developed that can be used for both positive ('hot') and negative contrasts ('cold'). The 3 cm long fillable tubes are arranged in six sectors having equal inner diameters ranging from 1 mm to 6 mm with plastic wall thicknesses of <0.25 mm, on a pitch of twice their inner diameters. Scans of the activity filled tubes using simple circular trajectories are obtained in a 215 mL uniform water filled cylinder, varying the rod:background concentration ratios from 10:1 to 1:10 simulating a large range of biological uptake ratios. The rod phantom is then placed inside a non-uniformly shaped 500 mL breast phantom and scans are again acquired using both simple and complex 3D trajectories for similarly varying contrasts. Summed slice and contiguous multi-slice images are evaluated by five independent readers, identifying the smallest distinguishable rod for each concentration and experimental setup. Linear and quadratic regression is used to compare the resulting contrast-detail curves. Results indicate that in a moderately low-noise 500 mL background, using the SPECT camera having 2.5 mm intrinsic pixels, the mean detectable rod was ~3.4 mm at a 10:1 ratio, degrading to ~5.2 mm with the 2.5:1 concentration ratio. The smallest object detail was observed using a 45° tilted trajectory acquisition. The complex 3D projected sine wave acquisition, however, had the most consistent combined intra- and inter-observer results, making it potentially the best imaging approach for consistent results.

  7. Final Report: A CdZnTe detector for MRI-compatible SPECT Systems

    SciTech Connect

    Meng, Ling-Jian

    2012-12-27

    The key objective of this project is to develop the enabling technology for future MRI-compatible nuclear (e.g. SPECT) imaging system, and to demonstrate the feasibility of performing simultaneous MR and SPECT imaging studies of the same object. During the past three years, we have developed (a) a MRI-compatible ultrahigh resolution gamma ray detector and associated readout electronics, (b) a theoretical approach for modeling the effect of strong magnetic field on SPECT image quality, and (c) a maximum-likelihood (ML) based reconstruction routine with correction for the MR-induced distortion. With this support, we have also constructed a four-head MR-compatible SPECT system and tested the system inside a 3-T clinical MR-scanner located on UI campus. The experimental results obtained with this system have clearly demonstrated that sub-500um spatial resolution can be achieved with a SPECT system operated inside a 3-T MRI scanner. During the past three years, we have accomplished most of the major objectives outlined in the original proposal. These research efforts have laid out a solid foundation the development of future MR-compatible SPECT systems for both pre-clinical and clinical imaging applications.

  8. Performance characterization of a new CZT-based preclinical SPECT system: a comparative study of different collimators

    NASA Astrophysics Data System (ADS)

    Yu, A. R.; Park, S.-J.; Choi, Y. Y.; Kim, K. M.; Kim, H.-J.

    2015-09-01

    Triumph X-SPECT is a newly released CZT-based preclinical small-animal SPECT system with interchangeable collimators. The purpose of this work was to evaluate and systematically compare the imaging performances of three different collimators in the CZT-based preclinical small-animal system: a single-pinhole collimator (SPH), a multi-pinhole collimator (MPH) and a parallel-hole collimator. We measured the spatial resolutions and sensitivities of the three collimators with 99mTc sources, considering three distinct energy window widths (5, 10, and 20%), and used the NEMA NU4-2008 Image Quality phantom to test the imaging performance of the three collimators in terms of uniformity and spill-over ratio (SOR) for each energy window. With a 10% energy window width at a radius of rotation (ROR) of 30 mm, the system resolution of the SPH, MPH and parallel-hole collimators was 0.715, 0.855 and 3.270 mm FWHM, respectively. For the same energy window, the sensitivity of the system with SPH, MPH and parallel-hole collimators was 32.860, 152.514 and 49.205 counts/sec/MBq at a 100 mm source-to-detector distance and 6.790, 33.376 and 49.038 counts/sec/MBq at a 130 mm source-to-detector distance, respectively. The image noise and SORair for the three collimators were 20.137, 12.278 and 11.232 (%STDunif) and 0.106, 0.140 and 0.161, respectively. Overall, the results show that the SPH had better spatial resolution than the other collimators. The MPH had the highest sensitivity at 100 mm source-to-collimator distance, and the parallel-hole collimator had the highest sensitivity at 130 mm-source-to-detector distance. Therefore, the proper collimator for Triumph X-SPECT system must be determined by the task. These results provide valuable reference data and insight into the imaging performance of various collimators in CZT-based preclinical small-animal SPECT.

  9. Assessment of hybrid rotation-translation scan schemes for in vivo animal SPECT imaging

    NASA Astrophysics Data System (ADS)

    Xia, Yan; Yao, Rutao; Deng, Xiao; Liu, Yaqiang; Wang, Shi; Ma, Tianyu

    2013-02-01

    To perform in vivo animal single photon emission computed tomography imaging on a stationary detector gantry, we introduced a hybrid rotation-translation (HRT) tomographic scan, a combination of translational and limited angle rotational movements of the image object, to minimize gravity-induced animal motion. To quantitatively assess the performance of ten HRT scan schemes and the conventional rotation-only scan scheme, two simulated phantoms were first scanned with each scheme to derive the corresponding image resolution (IR) in the image field of view. The IR results of all the scan schemes were visually assessed and compared with corresponding outputs of four scan scheme evaluation indices, i.e. sampling completeness (SC), sensitivity (S), conventional system resolution (SR), and a newly devised directional spatial resolution (DR) that measures the resolution in any specified orientation. A representative HRT scheme was tested with an experimental phantom study. Eight of the ten HRT scan schemes evaluated achieved a superior performance compared to two other HRT schemes and the rotation-only scheme in terms of phantom image resolution. The same eight HRT scan schemes also achieved equivalent or better performance in terms of the four quantitative indices than the conventional rotation-only scheme. As compared to the conventional index SR, the new index DR appears to be a more relevant indicator of system resolution performance. The experimental phantom image obtained from the selected HRT scheme was satisfactory. We conclude that it is feasible to perform in vivo animal imaging with a HRT scan scheme and SC and DR are useful predictors for quantitatively assessing the performance of a scan scheme.

  10. System characteristics of SPECT with a slat collimated strip detector.

    PubMed

    Vandenberghe, Stefaan; Van Holen, Roel; Staelens, Steven; Lemahieu, Ignace

    2006-01-21

    In classical SPECT with parallel hole collimation, the sensitivity is constant over the field of view (FOV). This is no longer the case if a rotating slat collimator with planar photon collection is used: there will be a significant variation of the sensitivity within the FOV. Since not compensating for this inhomogeneous sensitivity distribution would result in non-quantitative images, an accurate knowledge of the sensitivity is mandatory to account for it during reconstruction. On the other hand, the spatial resolution versus distance dependency remains unaltered compared to parallel hole collimation. For deriving the sensitivity, different factors have to be taken into account: a first factor concerns the intrinsic detector properties and will be incorporated into the calculations as a detection efficiency term depending on the incident angle. The calculations are based on a second and more pronounced factor: the collimator and detector geometry. Several assumptions will be made for the calculation of the sensitivity formulae and it will be proven that these calculations deliver a valid prediction of the sensitivity at points far enough from the collimator. To derive a close field model which also accounts for points close to the collimator surface, a modified calculation method is used. After calculating the sensitivity in one plane it is easy to obtain the tomographic sensitivity. This is done by rotating the sensitivity maps for spin and camera rotation. The results derived from the calculations are then compared to simulation results and both show good agreement after including the aforementioned detection efficiency term. The validity of the calculations is also proven by measuring the sensitivity in the FOV of a prototype rotating slat gamma camera. An expression for the resolution of these planar collimation systems is obtained. It is shown that for equal collimator dimensions the same resolution-distance relationship is obtained as for parallel hole

  11. A hardware investigation of robotic SPECT for functional and molecular imaging onboard radiation therapy systems

    PubMed Central

    Yan, Susu; Bowsher, James; Tough, MengHeng; Cheng, Lin; Yin, Fang-Fang

    2014-01-01

    Purpose: To construct a robotic SPECT system and to demonstrate its capability to image a thorax phantom on a radiation therapy flat-top couch, as a step toward onboard functional and molecular imaging in radiation therapy. Methods: A robotic SPECT imaging system was constructed utilizing a gamma camera detector (Digirad 2020tc) and a robot (KUKA KR150 L110 robot). An imaging study was performed with a phantom (PET CT PhantomTM), which includes five spheres of 10, 13, 17, 22, and 28 mm diameters. The phantom was placed on a flat-top couch. SPECT projections were acquired either with a parallel-hole collimator or a single-pinhole collimator, both without background in the phantom and with background at 1/10th the sphere activity concentration. The imaging trajectories of parallel-hole and pinhole collimated detectors spanned 180° and 228°, respectively. The pinhole detector viewed an off-centered spherical common volume which encompassed the 28 and 22 mm spheres. The common volume for parallel-hole system was centered at the phantom which encompassed all five spheres in the phantom. The maneuverability of the robotic system was tested by navigating the detector to trace the phantom and flat-top table while avoiding collision and maintaining the closest possible proximity to the common volume. The robot base and tool coordinates were used for image reconstruction. Results: The robotic SPECT system was able to maneuver parallel-hole and pinhole collimated SPECT detectors in close proximity to the phantom, minimizing impact of the flat-top couch on detector radius of rotation. Without background, all five spheres were visible in the reconstructed parallel-hole image, while four spheres, all except the smallest one, were visible in the reconstructed pinhole image. With background, three spheres of 17, 22, and 28 mm diameters were readily observed with the parallel-hole imaging, and the targeted spheres (22 and 28 mm diameters) were readily observed in the pinhole

  12. A hardware investigation of robotic SPECT for functional and molecular imaging onboard radiation therapy systems

    SciTech Connect

    Yan, Susu Tough, MengHeng; Bowsher, James; Yin, Fang-Fang; Cheng, Lin

    2014-11-01

    Purpose: To construct a robotic SPECT system and to demonstrate its capability to image a thorax phantom on a radiation therapy flat-top couch, as a step toward onboard functional and molecular imaging in radiation therapy. Methods: A robotic SPECT imaging system was constructed utilizing a gamma camera detector (Digirad 2020tc) and a robot (KUKA KR150 L110 robot). An imaging study was performed with a phantom (PET CT Phantom{sup TM}), which includes five spheres of 10, 13, 17, 22, and 28 mm diameters. The phantom was placed on a flat-top couch. SPECT projections were acquired either with a parallel-hole collimator or a single-pinhole collimator, both without background in the phantom and with background at 1/10th the sphere activity concentration. The imaging trajectories of parallel-hole and pinhole collimated detectors spanned 180° and 228°, respectively. The pinhole detector viewed an off-centered spherical common volume which encompassed the 28 and 22 mm spheres. The common volume for parallel-hole system was centered at the phantom which encompassed all five spheres in the phantom. The maneuverability of the robotic system was tested by navigating the detector to trace the phantom and flat-top table while avoiding collision and maintaining the closest possible proximity to the common volume. The robot base and tool coordinates were used for image reconstruction. Results: The robotic SPECT system was able to maneuver parallel-hole and pinhole collimated SPECT detectors in close proximity to the phantom, minimizing impact of the flat-top couch on detector radius of rotation. Without background, all five spheres were visible in the reconstructed parallel-hole image, while four spheres, all except the smallest one, were visible in the reconstructed pinhole image. With background, three spheres of 17, 22, and 28 mm diameters were readily observed with the parallel-hole imaging, and the targeted spheres (22 and 28 mm diameters) were readily observed in the

  13. Improving the count rate performance of a modular cylindrical SPECT system

    SciTech Connect

    Li, Y.J.; Hollinger, E.F.; Liu, J.; Chang, W.

    1996-12-31

    We recently proposed a design of a modular cylindrical cardiac SPECT system. one special feature of this system is an integrated provision for transmission imaging. To meet the clinical demands of obtaining transmission images, this system must be able to achieve a very high count rate (CR). To explore methods for achieving a high CR capability on a modular cylindrical detector system, we have used our existing modular cylindrical brain SPECT system to examine the feasibility of two approaches. First, we use digital-signal-processing (DSP) boards, in parallel, to execute real time position calculations. Second, we use local encoding and triggering circuits to perform analog signal processing, including identifying the detector module and digitizing the pulse signals. The results of our preliminary investigations indicate that applying the multiple-DSP parallel position calculation and local triggering techniques in a modular SPECT system can improve the CR capability significantly. Applying local triggering increased the CR capability by 15% at a CR capability of 200 kcps. Because we have used slow-speed DSP boards during this proof-of-concept testing, we have not yet met the CR requirements for transmission imaging. However, these results indicate that by using state-of-the-art DSP boards the CR capability of this modular SPECT system can be increased to over 300 kcps.

  14. Dual isotope cross-talk correction in Tc-99m/In-111 small-animal SPECT

    NASA Astrophysics Data System (ADS)

    Timmins, Rachel

    Dual-isotope imaging via energy discrimination is a major strength of SPECT but image quality is degraded by cross-talk interference. Direct application of clinically developed cross-talk correction techniques in small-animals is not ideal. Reduced subject size may allow adequate quantification with simpler cross-talk correction methods. This study evaluated four simple cross-talk correction methods for In-111/Tc--99m small-animal imaging: triple energy window (TEW), applied pre- and post-correction, convolution subtraction, and a vendor-supplied correction. Each method was evaluated using a three-syringe phantom filled with either Tc-99m, In-111, or a mixture of the two at five different ratios. The optimal method was tested on in-vivo rat images. A modified TEW applied in projection space visually provided the best removal of In-111 cross-talk and reduced it quantitatively by 96%. The mixed syringe ratios were recovered to within 5%. In-vivo testing provided inconclusive results indicating that a true dual-isotope study is still necessary.

  15. Feasibility and Initial Performance of Simultaneous SPECT-CT Imaging Using a Commercial Multi-Modality Preclinical Imaging System

    PubMed Central

    Osborne, Dustin R.; Austin, Derek W.

    2015-01-01

    Multi-modality imaging provides coregistered PET-CT and SPECT-CT images; however such multi-modality workflows usually consist of sequential scans from the individual imaging components for each modality. This typical workflow may result in long scan times limiting throughput of the imaging system. Conversely, acquiring multi-modality data simultaneously may improve correlation and registration of images, improve temporal alignment of the acquired data, increase imaging throughput, and benefit the scanned subject by minimizing time under anesthetic. In this work, we demonstrate the feasibility and procedure for modifying a commercially available preclinical SPECT-CT platform to enable simultaneous SPECT-CT acquisition. We also evaluate the performance of simultaneous SPECT-CT tomographic imaging with this modified system. Performance was accessed using a 57Co source and image quality was evaluated with 99mTc phantoms in a series of simultaneous SPECT-CT scans. PMID:26146568

  16. End-expiration respiratory gating for a high-resolution stationary cardiac SPECT system

    NASA Astrophysics Data System (ADS)

    Chan, Chung; Harris, Mark; Le, Max; Biondi, James; Grobshtein, Yariv; Liu, Yi-Hwa; Sinusas, Albert J.; Liu, Chi

    2014-10-01

    Respiratory and cardiac motions can degrade myocardial perfusion SPECT (MPS) image quality and reduce defect detection and quantitative accuracy. In this study, we developed a dual respiratory and cardiac gating system for a high-resolution fully stationary cardiac SPECT scanner in order to improve the image quality and defect detection. Respiratory motion was monitored using a compressive sensor pillow connected to a dual respiratory-cardiac gating box, which sends cardiac triggers only during end-expiration phases to the single cardiac trigger input on the SPECT scanners. The listmode data were rebinned retrospectively into end-expiration frames for respiratory motion reduction or eight cardiac gates only during end-expiration phases to compensate for both respiratory and cardiac motions. The proposed method was first validated on a motion phantom in the presence and absence of multiple perfusion defects, and then applied on 11 patient studies with and without perfusion defects. In the normal phantom studies, the end-expiration gated SPECT (EXG-SPECT) reduced respiratory motion blur and increased myocardium to blood pool contrast by 51.2% as compared to the ungated images. The proposed method also yielded an average of 11.2% increase in myocardium to defect contrast as compared to the ungated images in the phantom studies with perfusion defects. In the patient studies, EXG-SPECT significantly improved the myocardium to blood pool contrast (p < 0.005) by 24% on average as compared to the ungated images, and led to improved perfusion uniformity across segments on polar maps for normal patients. For a patient with defect, EXG-SPECT improved the defect contrast and definition. The dual respiratory-cardiac gating further reduced the blurring effect, increased the myocardium to blood pool contrast significantly by 36% (p < 0.05) compared to EXG-SPECT, and further improved defect characteristics and visualization of fine structures at the expense of increased noise on

  17. End-expiration Respiratory Gating for a High Resolution Stationary Cardiac SPECT system

    PubMed Central

    Chan, Chung; Harris, Mark; Le, Max; Biondi, James; Grobshtein, Yariv; Liu, Yi-Hwa; Sinusas, Albert J.; Liu, Chi

    2014-01-01

    Respiratory and cardiac motions can degrade myocardial perfusion SPECT (MPS) image quality and reduce defect detection and quantitative accuracy. In this study, we developed a dual-respiratory and cardiac gating system for a high resolution fully stationary cardiac SPECT scanner in order to improve the image quality and defect detection. Respiratory motion was monitored using a compressive sensor pillow connected to a dual respiratory-cardiac gating box, which sends cardiac triggers only during end-expiration phases to the single cardiac trigger input on the SPECT scanners. The listmode data were rebinned retrospectively into end-expiration frames for respiratory motion reduction or 8 cardiac gates only during end-expiration phases to compensate for both respiratory and cardiac motions. The proposed method was first validated on a motion phantom in the presence and absence of multiple perfusion defects, and then applied on 11 patient studies with and without perfusion defects. In the normal phantom studies, the end-expiration gated SPECT (EXG-SPECT) reduced respiratory motion blur and increased myocardium to blood pool contrast by 51.2% as compared to the ungated images. The proposed method also yielded an average of 11.2% increase in myocardium to defect contrast as compared to the ungated images in the phantom studies with perfusion defects. In the patient studies, EXG-SPECT significantly improved the myocardium to blood pool contrast (p<0.005) by 24% on average as compared to the ungated images, and led to improved perfusion uniformity across segments on polar maps for normal patients. For a patient with defect, EXG-SPECT improved the defect contrast and definition. The dual respiratory-cardiac gating further reduced the blurring effect, increased the myocardium to blood pool contrast significantly by 36% (p<0.05) compared to EXG SPECT, and further improved defect characteristics and visualization of fine structures at the expense of increased noise on the

  18. Monte Carlo methods for the simulation of positron emitters in SPECT systems

    SciTech Connect

    Dobrzeniecki, A.B.; Selcow, E.C.; Yanch, J.C.; Belanger, M.J.; Lu, A.; Esser, P.D.

    1996-12-31

    Monte Carlo simulations of nuclear medical systems are being widely used to better understand the characteristics of the acquired images. Single-photon emission computed tomography (SPECT) is an imaging modality that provides a physician with a nuclear medical image of function in an organ. In SPECT systems, the patient is injected with a radiopharmaceutical that is labeled with a photon-emitting radioisotope. A collimated gamma camera revolves around the patient, providing a series of planar images, which are then reconstructed to produce a three-dimensional image of the radiotracer distribution in the patient or phantom. The usage of positron emission computed tomography (PET) systems with {sup 18}F-labeled fluorodeoxyglucose (FDG) is an important mechanism for quantitating tumor glucose metabolism. This may facilitate the detection of primary and metastatic malignancies and the distinction between tissue regions that are normal, fibrous, necrotic, or cancerous. However, PET facilities are implemented in significantly fewer hospitals in the United States than SPECT systems. To address this issue and provide similar functional information to a clinician, there is a growing interest in imaging the 511-keV photons associated with PET agents in SPECT imaging systems. Note that the clinical utility of FDG as a diagnostic radiopharmaceutical cannot be replicated by known radiotracers emitting single photons. The authors are extending their simulations of SPECT systems to higher photon energies, where at present there is more disagreement between simulations and actual data. They discuss here possible reasons for this and steps being taken to address this discrepancy in the development of the modeling.

  19. Half-cone beam collimation for triple-camera SPECT systems

    SciTech Connect

    Li, Jianying; Jaszczak, R.J.; Van Mullekom, A. |

    1996-03-01

    Cone-beam collimators provide increased sensitivity at similar resolution compared to other collimators. The use of cone-beam collimators for brain imaging with triple-camera SPECT systems, however, results in truncation of the base of the brain because of clearance of the shoulders. A half-cone beam collimator does not have the problem of truncation. The objective of this study was to compare the performance characteristics of half-cone beam with parallel-beam and fan-beam collimators with similar resolution characteristics for SPECT imaging of the brain. A half-cone beam collimator with the focal point located towards the base of the brain was built for a triple-camera SPECT system. Spatial resolutions and sensitivities of three collimators were measured. When 10-cm from the collimator surface, the planar spatial resolutions FWHM in mm (point source sensitivities in cps-MBq) for half-cone beam, fan-beam and parallel-beam collimators were 5.2 (85.6), 5.1 (55.6) and 5.9 (39.7), respectively. Image quality was evaluated using a three-dimensional Hoffman brain phantom and patient data. The deeper gray matter were more clearly visualized in the half-cone beam scans. Half-cone beam collimation provides higher sensitivity and offers the potential for improved brain imaging compared with parallel-beam and fan-beam collimation when used with a triple-camera SPECT system. 23 refs., 9 figs., 1 tab.

  20. A flexible high-rate USB2 data acquisition system for PET and SPECT imaging

    SciTech Connect

    J. Proffitt, W. Hammond, S. Majewski, V. Popov, R.R. Raylman, A.G. Weisenberger, R. Wojcik

    2006-02-01

    A new flexible data acquisition system has been developed to instrument gamma-ray imaging detectors designed by the Jefferson Lab Detector and Imaging Group. Hardware consists of 16-channel data acquisition modules installed on USB2 carrier boards. Carriers have been designed to accept one, two, and four modules. Application trigger rate and channel density determines the number of acquisition boards and readout computers used. Each channel has an independent trigger, gated integrator and a 2.5 MHz 12-bit ADC. Each module has an FPGA for analog control and signal processing. Processing includes a 5 ns 40-bit trigger time stamp and programmable triggering, gating, ADC timing, offset and gain correction, charge and pulse-width discrimination, sparsification, event counting, and event assembly. The carrier manages global triggering and transfers module data to a USB buffer. High-granularity time-stamped triggering is suitable for modular detectors. Time stamped events permit dynamic studies, complex offline event assembly, and high-rate distributed data acquisition. A sustained USB data rate of 20 Mbytes/s, a sustained trigger rate of 300 kHz for 32 channels, and a peak trigger rate of 2.5 MHz to FIFO memory were achieved. Different trigger, gating, processing, and event assembly techniques were explored. Target applications include >100 kHz coincidence rate PET detectors, dynamic SPECT detectors, miniature and portable gamma detectors for small-animal and clinical use.

  1. Recent advances in SPECT

    SciTech Connect

    Tsui, Benjamin M. W.

    1998-08-28

    Single photon emission computed tomography (SPECT) is a medical imaging modality that combines conventional nuclear medicine imaging technique and methods of computed tomography (CT). From images that represent the biodistribution of the injected radiopharmaceutical in the patient, SPECT provides functional information that is unique. The first SPECT system was developed in the sixties. However, early progress of SPECT was hampered by the lack of adequate image reconstruction methods. The development of x-ray CT and image reconstruction methods in the seventies spurred a renewed interest in SPECT. In 1981, the first commercial SPECT system based on a single rotating camera was available for clinical use. Today, most modern SPECT systems consist of multiple cameras that rotate around the patients. They have better spatial resolution and higher detection efficiency as compared to the earlier single camera systems. Recently, a new generation of dual camera systems allowing for coincidence imaging of positron emitting radiopharmaceuticals has emerged in the commercial market. Additionally, new quantitative image reconstruction methods are under development. They compensate for image degrading factors including attenuation, collimator-detector blurring and scatter. Also, they result in SPECT images with improved image quality and more accurately represent the three-dimensional radioactivity distribution in the patient. Such advances in radiopharmaceuticals, instrumentation, image reconstruction, compensation methods, and clinical applications have fueled a steady growth of SPECT as an important diagnostic tool in patient management.

  2. Space Launch System Animation

    NASA Video Gallery

    NASA is ready to move forward with the development of the Space Launch System -- an advanced heavy-lift launch vehicle that will provide an entirely new national capability for human exploration be...

  3. First imaging result with an ultrahigh resolution stationary MR compatible SPECT system

    PubMed Central

    Cai, L.; Shen, Z. M.; Zhang, J. C.; Chen, C. T.; Meng, L. J.

    2013-01-01

    In this paper, we will present the design and preliminary performance of an ultrahigh resolution stationary MR compatible SPECT (MRC-SPECT) system that is developed in our lab. The MRC-SPECT system is based on the second-generation energy-resolved photon-counting (ERPC) CdTe detectors and there are several key features associated with this system. Firstly, up to a total of twenty ERPC detectors will be assembled as a very compact ring, which provides an adequate angular sampling capability and a relatively high detection efficiency. The detectors are supported on a gantry made of high strength polyamide structure constructed using 3-D printing. This compact system can be directly operated inside an MR scanner. The detector module used in this system offers an intrinsic resolution of 350μm and an excellent energy resolution of around 3~4kev. Each ERPC detector module consists of four pixelated CdTe detectors with a total dimension of 4.5cm×2.25cm. Secondly, a die-cast platinum pinhole inserts and cast lead apertures are developed for this stationary SPECT system. Four 300/500μm diameter pinholes are used for each detector and all pinholes are mounted around a casted cylinder lead aperture tube. The inner diameter of the lead aperture tube is 6cm and the lead tube thickness is 16mm. The opposite detectors are placed 15.6cm apart and the magnification factor of this SPECT system is about 1.2. Thirdly, a comprehensive charge collection model inside strong magnetic field has been developed to account for the magnetic field induced distortion in the SPECT image. This model can accurately predict the detector’s energy and spatial response to gamma ray incident events and then help to compensate for the event position recording error due to the strong magnetic field. In this development, we have made an effort to minimize the amount of magnetic materials in the system to alleviate potential interference to magnetic field inhomogeneity. PMID:26692275

  4. Rodent brain imaging with SPECT/CT

    SciTech Connect

    Seo, Youngho; Gao, D.-W.; Hasegawa, Bruce H.; Dae, Michael W.; Franc, Benjamin L.

    2007-04-15

    We evaluated methods of imaging rat models of stroke in vivo using a single photon emission computed tomography (SPECT) system dedicated to small animal imaging (X-SPECT{sup TM}, Gamma Medica-Ideas, Northridge, CA). An animal model of ischemic stroke was developed for in vivo SPECT/CT imaging using the middle cerebral artery occlusion (MCAO) technique. The presence of cerebral ischemia was verified in ex vivo studies using triphenyltetrazolium chloride (TTC) staining. In vivo radionuclide imaging of cerebral blood flow was performed in rats following MCAO using dynamic planar imaging of {sup 99m}Tc-exametazime with parallel hole collimation. This was followed immediately by in vivo radionuclide imaging of cerebral blood flow with {sup 99m}Tc-exametazime in the same animals using 1-mm pinhole SPECT. Correlated computed tomography imaging was performed to localize radiopharmaceutical uptake. The animals were allowed to recover and ex vivo autoradiography was performed with separate administration of {sup 99m}Tc-exametazime. Time activity curve of {sup 99m}Tc-exametazime showed that the radiopharmaceutical uptake could be maintained for over 9 min. The activity would be expected to be relatively stable for a much longer period, although the data were only obtained for 9 min. TTC staining revealed sizable infarcts by visual observation of inexistence of TTC stain in infracted tissues of MCAO rat brains. In vivo SPECT imaging showed cerebral blood flow deficit in the MCAO model, and the in vivo imaging result was confirmed with ex vivo autoradiography. We have demonstrated a capability of imaging regions of cerebral blood flow deficit in MCAO rat brains in vivo using a pinhole SPECT dedicated to small animal imaging.

  5. Improved image quality in pinhole SPECT by accurate modeling of the point spread function in low magnification systems

    SciTech Connect

    Pino, Francisco; Roé, Nuria; Aguiar, Pablo; Falcon, Carles; Ros, Domènec; Pavía, Javier

    2015-02-15

    Purpose: Single photon emission computed tomography (SPECT) has become an important noninvasive imaging technique in small-animal research. Due to the high resolution required in small-animal SPECT systems, the spatially variant system response needs to be included in the reconstruction algorithm. Accurate modeling of the system response should result in a major improvement in the quality of reconstructed images. The aim of this study was to quantitatively assess the impact that an accurate modeling of spatially variant collimator/detector response has on image-quality parameters, using a low magnification SPECT system equipped with a pinhole collimator and a small gamma camera. Methods: Three methods were used to model the point spread function (PSF). For the first, only the geometrical pinhole aperture was included in the PSF. For the second, the septal penetration through the pinhole collimator was added. In the third method, the measured intrinsic detector response was incorporated. Tomographic spatial resolution was evaluated and contrast, recovery coefficients, contrast-to-noise ratio, and noise were quantified using a custom-built NEMA NU 4–2008 image-quality phantom. Results: A high correlation was found between the experimental data corresponding to intrinsic detector response and the fitted values obtained by means of an asymmetric Gaussian distribution. For all PSF models, resolution improved as the distance from the point source to the center of the field of view increased and when the acquisition radius diminished. An improvement of resolution was observed after a minimum of five iterations when the PSF modeling included more corrections. Contrast, recovery coefficients, and contrast-to-noise ratio were better for the same level of noise in the image when more accurate models were included. Ring-type artifacts were observed when the number of iterations exceeded 12. Conclusions: Accurate modeling of the PSF improves resolution, contrast, and recovery

  6. Feasibility study of SPECT system for online dosimetry imaging in boron neutron capture therapy.

    PubMed

    Hales, B; Katabuchi, T; Hayashizaki, N; Terada, K; Igashira, M; Kobayashi, T

    2014-06-01

    A single collimator version of a proposed PG-SPECT system was manufactured and experimentally tested. Combining this experimental data with Monte Carlo simulation, the viability of Ge and CdTe semiconductors detectors was calculated. It was determined that the best detector of the ones compared would be a CdTe detector of 2-3mm, aided by the benefit of adding a Compton-suppression anti-coincidence timing detector. PMID:24378365

  7. Design and evaluation of a mobile bedside PET/SPECT imaging system

    NASA Astrophysics Data System (ADS)

    Studenski, Matthew Thomas

    Patients confined to an intensive care unit, the emergency room, or a surgical suite are managed without nuclear medicine procedures such as positron emission tomography (PET) or single photon emission computed tomography (SPECT). These studies have diagnostic value which can greatly benefit the physician's treatment of the patient but require that the patient is moved to a scanner. This dissertation examines the feasibility of an economical PET/SPECT system that can be brought to the bedside of an immobile patient for imaging. We chose to focus on cardiac SPECT imaging including perfusion imaging using 99mTc tracers and viability imaging using 18F tracers first because of problems arising from positioning a detector beneath a patient's bed, a requirement for the opposed detector orientation in PET imaging. Second, SPECT imaging acquiring over the anterior 180 degrees of the patient results in reduced attenuation effects due to the heart's location in the anterior portion of the body. Four studies were done to assess the clinical feasibility of the mobile system; 1) the performance of the system was evaluated in SPECT mode at both 140 keV (99mTc tracers) and 511 keV (positron emitting tracers), 2) a dynamic cardiac phantom was used to develop and test image acquisition and processing methods for the system at both energies, 3) a high energy pinhole collimator was designed to reduce the effects of high energy photon penetration through the parallel hole collimator, and 4) we estimated the radiation dose to persons that would be in the vicinity of a patient to ensure that the effective dose is below the regulatory limit. With these studies, we show that the mobile system provides an economical means of bringing nuclear medicine to an immobile patient while staying below the regulatory dose limit to other persons. The system performed well at both 140 keV and 511 keV and provided viable images of a phantom myocardium at both energies. The system does not achieve the

  8. Extrapyramidal system neurotoxicity: animal models.

    PubMed

    Dorman, David

    2015-01-01

    The central nervous system's extrapyramidal system provides involuntary motor control to the muscles of the head, neck, and limbs. Toxicants that affect the extrapyramidal system are generally clinically characterized by impaired motor control, which is usually the result of basal ganglionic dysfunction. A variety of extrapyramidal syndromes are recognized in humans and include Parkinson's disease, secondary parkinsonism, other degenerative diseases of the basal ganglia, and clinical syndromes that result in dystonia, dyskinesia, essential tremor, and other forms of tremor and chorea. This chapter briefly reviews the anatomy of the extrapyramidal system and discusses several naturally occurring and experimental models that target the mammalian (nonhuman) extrapyramidal system. Topics discussed include extrapyramidal syndromes associated with antipsychotic drugs, carbon monoxide, reserpine, cyanide, rotenone, paraquat, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), and manganese. In most cases, animals are used as experimental models to improve our understanding of the toxicity and pathogenesis of these agents. Another agent discussed in this chapter, yellowstar thistle poisoning in horses, however, represents an important spontaneous cause of parkinsonism that naturally occurs in animals. The central focus of the chapter is on animal models, especially the concordance between clinical signs, neurochemical changes, and neuropathology between animals and people. PMID:26563791

  9. A line-source method for aligning on-board and other pinhole SPECT systems

    PubMed Central

    Yan, Susu; Bowsher, James; Yin, Fang-Fang

    2013-01-01

    Purpose: In order to achieve functional and molecular imaging as patients are in position for radiation therapy, a robotic multipinhole SPECT system is being developed. Alignment of the SPECT system—to the linear accelerator (LINAC) coordinate frame and to the coordinate frames of other on-board imaging systems such as cone-beam CT (CBCT)—is essential for target localization and image reconstruction. An alignment method that utilizes line sources and one pinhole projection is proposed and investigated to achieve this goal. Potentially, this method could also be applied to the calibration of the other pinhole SPECT systems. Methods: An alignment model consisting of multiple alignment parameters was developed which maps line sources in three-dimensional (3D) space to their two-dimensional (2D) projections on the SPECT detector. In a computer-simulation study, 3D coordinates of line-sources were defined in a reference room coordinate frame, such as the LINAC coordinate frame. Corresponding 2D line-source projections were generated by computer simulation that included SPECT blurring and noise effects. The Radon transform was utilized to detect angles (α) and offsets (ρ) of the line-source projections. Alignment parameters were then estimated by a nonlinear least squares method, based on the α and ρ values and the alignment model. Alignment performance was evaluated as a function of number of line sources, Radon transform accuracy, finite line-source width, intrinsic camera resolution, Poisson noise, and acquisition geometry. Experimental evaluations were performed using a physical line-source phantom and a pinhole-collimated gamma camera attached to a robot. Results: In computer-simulation studies, when there was no error in determining angles (α) and offsets (ρ) of the measured projections, six alignment parameters (three translational and three rotational) were estimated perfectly using three line sources. When angles (α) and offsets (ρ) were provided by

  10. A line-source method for aligning on-board and other pinhole SPECT systems

    SciTech Connect

    Yan, Susu; Bowsher, James; Yin, Fang-Fang

    2013-12-15

    Purpose: In order to achieve functional and molecular imaging as patients are in position for radiation therapy, a robotic multipinhole SPECT system is being developed. Alignment of the SPECT system—to the linear accelerator (LINAC) coordinate frame and to the coordinate frames of other on-board imaging systems such as cone-beam CT (CBCT)—is essential for target localization and image reconstruction. An alignment method that utilizes line sources and one pinhole projection is proposed and investigated to achieve this goal. Potentially, this method could also be applied to the calibration of the other pinhole SPECT systems.Methods: An alignment model consisting of multiple alignment parameters was developed which maps line sources in three-dimensional (3D) space to their two-dimensional (2D) projections on the SPECT detector. In a computer-simulation study, 3D coordinates of line-sources were defined in a reference room coordinate frame, such as the LINAC coordinate frame. Corresponding 2D line-source projections were generated by computer simulation that included SPECT blurring and noise effects. The Radon transform was utilized to detect angles (α) and offsets (ρ) of the line-source projections. Alignment parameters were then estimated by a nonlinear least squares method, based on the α and ρ values and the alignment model. Alignment performance was evaluated as a function of number of line sources, Radon transform accuracy, finite line-source width, intrinsic camera resolution, Poisson noise, and acquisition geometry. Experimental evaluations were performed using a physical line-source phantom and a pinhole-collimated gamma camera attached to a robot.Results: In computer-simulation studies, when there was no error in determining angles (α) and offsets (ρ) of the measured projections, six alignment parameters (three translational and three rotational) were estimated perfectly using three line sources. When angles (α) and offsets (ρ) were provided by

  11. Small-Animal SPECT/CT of the Progression and Recovery of Rat Liver Fibrosis by Using an Integrin αvβ3-targeting Radiotracer.

    PubMed

    Yu, Xinhe; Wu, Yue; Liu, Hao; Gao, Liquan; Sun, Xianlei; Zhang, Chenran; Shi, Jiyun; Zhao, Huiyun; Jia, Bing; Liu, Zhaofei; Wang, Fan

    2016-05-01

    Purpose To assess the potential utility of an integrin αvβ3-targeting radiotracer, technetium 99m-PEG4-E[PEG4-cyclo(arginine-glycine-aspartic acid-D-phenylalanine-lysine)]2 ((99m)Tc-3PRGD2), for single photon emission computed tomography (SPECT)/computed tomography (CT) for monitoring of the progression and prognosis of liver fibrosis in a rat model. Materials and Methods All animal experiments were performed by following the protocol approved by the institutional animal care and use committee. (99m)Tc-3PRGD2 was prepared and longitudinal SPECT/CT was performed to monitor the progression (n = 8) and recovery (n = 5) of liver fibrosis induced in a rat model by means of thioacetamide (TAA) administration. The mean liver-to-background radioactivity per unit volume ratio was analyzed for comparisons between the TAA and control (saline) groups at different stages of liver fibrosis. Data were compared by using Student t and Mann-Whitney tests. Results of SPECT/CT were compared with those of ex vivo biodistribution analysis (n = 5). Results Accumulation of (99m)Tc-3PRGD2 in the liver increased in proportion to the progression of fibrosis and TAA exposure time; accumulation levels were significantly different between the TAA and control groups as early as week 4 of TAA administration (liver-to-background ratio: 32.30 ± 3.39 vs 19.01 ± 3.31; P = .0002). Results of ex vivo immunofluorescence staining demonstrated the positive expression of integrin αvβ3 on the activated hepatic stellate cells, and the integrin αvβ3 levels in the liver corresponded to the results of SPECT/CT (R(2) = 0.75, P < .0001). (99m)Tc-3PRGD2 uptake in the fibrotic liver decreased after antifibrotic therapy with interferon α2b compared with that in the control group (relative liver-to-background ratio: 0.45 ± 0.05 vs 1.01 ± 0.05; P < .0001) or spontaneous recovery (relative liver-to-background ratio: 0.56 ± 0.06 vs 1.01 ± 0.05; P < .0001). Conclusion (99m)Tc-3PRGD2 SPECT/CT was successfully

  12. RAI Thyroid Bed Uptake After Total Thyroidectomy: A Novel SPECT-CT Anatomic Classification System

    PubMed Central

    Zeuren, Rebecca; Biagini, Agnese; Grewal, Ravinder K.; Randolph, Gregory W.; Kamani, Dipti; Sabra, Mona M.; Shaha, Ashok R.; Tuttle, R. Michael

    2016-01-01

    Objective Recent, more selective use of radioactive iodine (RAI) has led to reevaluation of the clinical importance of achieving complete total thyroidectomy with minimal residual normal thyroid tissue. We utilize the improved localization by post-RAI remnant ablation, single photon emission computerized tomography-computed tomography (SPECT-CT) to define specific anatomic sites of residual RAI-uptake foci after total thyroidectomy for differentiated thyroid cancer (DTC) and to provide a novel classification system relating uptake to thyroid anatomy and preservation of adjacent neural structures. Study Design Retrospective. Method Radioactive iodine-uptake foci in thyroid bed were localized by SPECT/CT imaging at the time of RAI remnant ablation in 141 DTC patients undergoing total thyroidectomy. Results Minimal residual RAI uptake (median 0.32% at 24 hours) in the thyroid bed was detected by diagnostic planar whole body scans in 93% and by posttherapy SPECT/CT imaging in 99% of subjects. Discrete RAI uptake foci were identified on the SPECT/CT imaging at Berry’s ligament (87%), at superior thyroid poles (79%), in paratracheal-lobar regions (67%), in isthmus-region (54%), and in pyramidal lobe (46%). Despite the residual foci, the nonstimulated thyroglobulin (Tg) prior to remnant ablation (with a median thyroid-stimulating hormone of 0.36 m IU/L) was <0.6 ng/mL in 53% and <1 ng/mL in 73% of cases. Conclusion After extracapsular total thyroidectomy, highly sensitive detection tools identify microscopic residual RAI avid foci in thyroid bed in the majority of patients. These foci can be classified as 1) neural-related and 2) capsule-related. These common residual foci have no relationship to postoperative Tg, suggesting that attempts at radical removal of thyroid tissue in these locations may not be warranted. PMID:25891354

  13. Comparative immune systems in animals.

    PubMed

    Yuan, Shaochun; Tao, Xin; Huang, Shengfeng; Chen, Shangwu; Xu, Anlong

    2014-02-01

    Animal immune systems can be classified into those of innate immunity and those of adaptive immunity. It is generally thought that the former are universal for all animals and depend on germline-encoded receptors that recognize highly conserved pathogen-associated molecular patterns (PAMPs), whereas the latter are vertebrate specific and are mediated primarily by lymphocytes bearing a unique antigen receptor. However, novel adaptive or adaptive-like immunities have been found in invertebrates and jawless vertebrates, and extraordinarily complex innate immunities, created through huge expansions of many innate gene families, have recently been found in the cephalochordate amphioxus and the echinoderm sea urchin. These studies not only inspire immunologists to seek novel immune mechanisms in invertebrates but also raise questions about the origin and evolution of vertebrate immunities. PMID:25384142

  14. Evaluation of a low-dose/slow-rotating SPECT-CT system

    NASA Astrophysics Data System (ADS)

    Hamann, M.; Aldridge, M.; Dickson, J.; Endozo, R.; Lozhkin, K.; Hutton, B. F.

    2008-05-01

    The 4-slice CT that forms part of the GE Infinia Hawkeye-4 SPECT-CT scanner (Hawkeye) is evaluated against the diagnostic 16-slice CT that is incorporated in the GE Discovery ST PET-CT system (DST). The x-ray tube of the slow-rotating Hawkeye system (23 s/rotation) operates at approximately a third of the dose of diagnostic systems as used for conventional diagnostic imaging. Image reconstruction is optimized for low noise. High-contrast spatial resolution significantly falls behind diagnostic figures: the average of MTF50 and MTF10 (resolution where the MTF has fallen to 50% and 10%) is 2.8 ± 0.1 cm-1 for Hawkeye and 5.3 ± 0.1 cm-1 for the DST (standard reconstruction filters). Resolution in the direction of the couch movement (z coordinate) is governed by the fixed Hawkeye slice width of 5 mm. Reconstruction accuracy is found to be increased by reducing the default z increment from 4.4 mm to 2.2 mm. Low-contrast object detectability is superior compared with diagnostic systems operating in the Hawkeye dose range. In the diagnostic dose regime, however, small low-contrast details remain visible in DST that are not detectable with Hawkeye. Although not of diagnostic quality, the low-dose Hawkeye provides appropriate data for SPECT attenuation correction and anatomical localization capability. For more information on this article, see medicalphysicsweb.org

  15. Estimating ROI activity concentration with photon-processing and photon-counting SPECT imaging systems

    NASA Astrophysics Data System (ADS)

    Jha, Abhinav K.; Frey, Eric C.

    2015-03-01

    Recently a new class of imaging systems, referred to as photon-processing (PP) systems, are being developed that uses real-time maximum-likelihood (ML) methods to estimate multiple attributes per detected photon and store these attributes in a list format. PP systems could have a number of potential advantages compared to systems that bin photons based on attributes such as energy, projection angle, and position, referred to as photon-counting (PC) systems. For example, PP systems do not suffer from binning-related information loss and provide the potential to extract information from attributes such as energy deposited by the detected photon. To quantify the effects of this advantage on task performance, objective evaluation studies are required. We performed this study in the context of quantitative 2-dimensional single-photon emission computed tomography (SPECT) imaging with the end task of estimating the mean activity concentration within a region of interest (ROI). We first theoretically outline the effect of null space on estimating the mean activity concentration, and argue that due to this effect, PP systems could have better estimation performance compared to PC systems with noise-free data. To evaluate the performance of PP and PC systems with noisy data, we developed a singular value decomposition (SVD)-based analytic method to estimate the activity concentration from PP systems. Using simulations, we studied the accuracy and precision of this technique in estimating the activity concentration. We used this framework to objectively compare PP and PC systems on the activity concentration estimation task. We investigated the effects of varying the size of the ROI and varying the number of bins for the attribute corresponding to the angular orientation of the detector in a continuously rotating SPECT system. The results indicate that in several cases, PP systems offer improved estimation performance compared to PC systems.

  16. Multiple system atrophy: natural history, MRI morphology, and dopamine receptor imaging with 123IBZM-SPECT.

    PubMed Central

    Schulz, J B; Klockgether, T; Petersen, D; Jauch, M; Müller-Schauenburg, W; Spieker, S; Voigt, K; Dichgans, J

    1994-01-01

    Sixteen patients with a clinical diagnosis of probable multiple system atrophy (MSA) were examined clinically by MRI and by 123I-iodobenzamide single photon emission computed tomography (IBZM-SPECT). The clinical records of another 16 patients were also analysed retrospectively. On the basis of their clinical presentation, patients were subdivided into those with prominent parkinsonism (MSA-P, n = 11) and those with prominent cerebellar ataxia (MSA-C, n = 21). Autonomic symptoms were present in all patients and preceded the onset of motor symptoms in 63% of patients. Calculated median lifetime and the median time to become wheelchair bound after onset of disease were significantly shorter for MSA-P than for MSA-C (lifetime: 4.0 v 9.1 years; wheelchair: 3.1 vs 5.0 years) suggesting a better prognosis for cerebellar patients. A significant loss of striatal dopamine receptors (below 2 SD threshold) was detected by IBZM-SPECT in 63% of the patients (56% below 2.5 SD threshold). There was no difference between patients with MSA-C and those with MSA-P in the proportion with significant receptor loss and the extent of dopamine receptor loss. Planimetric MRI evaluation showed cerebellar and brainstem atrophy in both groups. Atrophy was more pronounced in patients with MSA-C than in those with MSA-P. Pontocerebellar hyperintensities and putaminal hypointensities on T2 weighted MRI were found in both groups. Pontocerebellar signal abnormalities were more pronounced in MSA-C than in MSA-P, whereas the rating scores for area but not for intensity of putaminal abnormalities were higher in MSA-P. MRI and IBZM-SPECT provide in vivo evidence for combined basal ganglia and pontocerebellar involvement in almost all patients in this series. Images PMID:8089667

  17. Pharmacological challenge and synaptic response - assessing dopaminergic function in the rat striatum with small animal single-photon emission computed tomography (SPECT) and positron emission tomography (PET).

    PubMed

    Nikolaus, Susanne; Larisch, Rolf; Vosberg, Henning; Beu, Markus; Wirrwar, Andreas; Antke, Christina; Kley, Konstantin; Silva, Maria Angelica De Souza; Huston, Joseph P; Müller, Hans-Wilhelm

    2011-01-01

    Disturbances of dopaminergic neurotransmission may be caused by changes in concentrations of synaptic dopamine (DA) and/or availabilities of pre- and post-synaptic transporter and receptor binding sites. We present a series of experiments which focus on the regulatory mechanisms of the dopamin(DA)ergic synapse in the rat striatum. In these studies, DA transporter (DAT) and/or D(2) receptor binding were assessed with either small animal single-photon emission computed tomography (SPECT) or positron emission tomography (PET) after pharmacological challenge with haloperidol, L-DOPA and methylphenidate, and after nigrostriatal 6-hydroxydopamine lesion. Investigations of DAT binding were performed with [(123)I]N-ω-fluoropropyl-2β-carbomethoxy-3β-(4-iodophenyl)nortropane ([(123)I]FP-CIT). D(2) receptor bindingd was assessed with either [(123)I](S)-2-hydroxy-3-iodo-6-methoxy-N-[(1-ethyl-2-pyrrolidinyl)methyl]benzamide ([(123)I]IBZM) or [(18)F]1[3-(4'fluorobenzoyl)propyl]-4-(2-keto-3-methyl-1-benzimidazolinyl)piperidine ([(18)F]FMB). Findings demonstrate that in vivo investigations of transporter and/or receptor binding are feasible with small animal SPECT and PET. Therefore, tracers that are radiolabeled with isotopes of comparatively long half-lives such as (123)I may be employed. Our approach to quantify DAT and/or D(2) receptor binding at baseline and after pharmacological interventions inducing DAT blockade, D(2) receptor blockade, and increases or decreases of endogenous DA concentrations holds promise for the in vivo assessment of synaptic function. This pertains to animal models of diseases associated with pre- or postsynaptic DAergic deficiencies such as Parkinson's disease, Huntington's disease, attention-deficit/hyperactivity disorder, schizophrenia or drug abuse. PMID:22103308

  18. Analytical, experimental, and Monte Carlo system response matrix for pinhole SPECT reconstruction

    SciTech Connect

    Aguiar, Pablo; Pino, Francisco; Silva-Rodríguez, Jesús; Pavía, Javier; Ros, Doménec; Ruibal, Álvaro; and others

    2014-03-15

    Purpose: To assess the performance of two approaches to the system response matrix (SRM) calculation in pinhole single photon emission computed tomography (SPECT) reconstruction. Methods: Evaluation was performed using experimental data from a low magnification pinhole SPECT system that consisted of a rotating flat detector with a monolithic scintillator crystal. The SRM was computed following two approaches, which were based on Monte Carlo simulations (MC-SRM) and analytical techniques in combination with an experimental characterization (AE-SRM). The spatial response of the system, obtained by using the two approaches, was compared with experimental data. The effect of the MC-SRM and AE-SRM approaches on the reconstructed image was assessed in terms of image contrast, signal-to-noise ratio, image quality, and spatial resolution. To this end, acquisitions were carried out using a hot cylinder phantom (consisting of five fillable rods with diameters of 5, 4, 3, 2, and 1 mm and a uniform cylindrical chamber) and a custom-made Derenzo phantom, with center-to-center distances between adjacent rods of 1.5, 2.0, and 3.0 mm. Results: Good agreement was found for the spatial response of the system between measured data and results derived from MC-SRM and AE-SRM. Only minor differences for point sources at distances smaller than the radius of rotation and large incidence angles were found. Assessment of the effect on the reconstructed image showed a similar contrast for both approaches, with values higher than 0.9 for rod diameters greater than 1 mm and higher than 0.8 for rod diameter of 1 mm. The comparison in terms of image quality showed that all rods in the different sections of a custom-made Derenzo phantom could be distinguished. The spatial resolution (FWHM) was 0.7 mm at iteration 100 using both approaches. The SNR was lower for reconstructed images using MC-SRM than for those reconstructed using AE-SRM, indicating that AE-SRM deals better with the

  19. SU-C-201-02: Quantitative Small-Animal SPECT Without Scatter Correction Using High-Purity Germanium Detectors

    SciTech Connect

    Gearhart, A; Peterson, T; Johnson, L

    2015-06-15

    Purpose: To evaluate the impact of the exceptional energy resolution of germanium detectors for preclinical SPECT in comparison to conventional detectors. Methods: A cylindrical water phantom was created in GATE with a spherical Tc-99m source in the center. Sixty-four projections over 360 degrees using a pinhole collimator were simulated. The same phantom was simulated using air instead of water to establish the true reconstructed voxel intensity without attenuation. Attenuation correction based on the Chang method was performed on MLEM reconstructed images from the water phantom to determine a quantitative measure of the effectiveness of the attenuation correction. Similarly, a NEMA phantom was simulated, and the effectiveness of the attenuation correction was evaluated. Both simulations were carried out using both NaI detectors with an energy resolution of 10% FWHM and Ge detectors with an energy resolution of 1%. Results: Analysis shows that attenuation correction without scatter correction using germanium detectors can reconstruct a small spherical source to within 3.5%. Scatter analysis showed that for standard sized objects in a preclinical scanner, a NaI detector has a scatter-to-primary ratio between 7% and 12.5% compared to between 0.8% and 1.5% for a Ge detector. Preliminary results from line profiles through the NEMA phantom suggest that applying attenuation correction without scatter correction provides acceptable results for the Ge detectors but overestimates the phantom activity using NaI detectors. Due to the decreased scatter, we believe that the spillover ratio for the air and water cylinders in the NEMA phantom will be lower using germanium detectors compared to NaI detectors. Conclusion: This work indicates that the superior energy resolution of germanium detectors allows for less scattered photons to be included within the energy window compared to traditional SPECT detectors. This may allow for quantitative SPECT without implementing scatter

  20. Dynamic molecular imaging of cardiac innervation using a dual headpinhole SPECT system

    SciTech Connect

    Hu, Jicun; Boutchko, Rostyslav; Sitek, Arkadiusz; Reutter, BryanW.; Huesman, Ronald H.; Gullberg, Grant T.

    2008-03-29

    Typically 123I-MIBG is used for the study of innervation andfunction of the sympathetic nervous system in heart failure. The protocolinvolves two studies: first a planar or SPECT scan is performed tomeasure initial uptake of the tracer, followed some 3-4 hours later byanother study measuring the wash-out of the tracer from the heart. A fastwash-out is indicative of a compromised heart. In this work, a dual headpinhole SPECT system was used for imaging the distribution and kineticsof 123I-MIBG in the myocardium of spontaneous hypertensive rats (SHR) andnormotensive Wistar Kyoto (WKY) rats. The system geometry was calibratedbased on a nonlinear point projection fitting method using a three-pointsource phantom. The angle variation effect of the parameters was modeledwith a sinusoidal function. A dynamic acquisition was performed byinjecting 123I-MIBG into rats immediately after starting the dataacquisition. The detectors rotated continuously performing a 360o dataacquisition every 90 seconds. We applied the factor analysis (FA)methodand region of interest (ROI) sampling method to obtain time activitycurves (TACs)in the blood pool and myocardium and then appliedtwo-compartment modeling to estimate the kinetic parameters. Since theinitial injection bolus is too fast for obtaining a consistenttomographic data set in the first few minutes of the study, we appliedthe FA method directly to projections during the first rotation. Then thetime active curves for blood and myocardial tissue were obtained from ROIsampling. The method was applied to determine if there were differencesin the kinetics between SHR and WKY rats and requires less time byreplacing the delayed scan at 3-4 hours after injection with a dynamicacquisition over 90 to 120 minutes. The results of a faster washout and asmaller distribution volume of 123IMIBG near the end of life in the SHRmodel of hypertrophic cardiomyopthy may be indicative of a failing heartin late stages of heart failure.

  1. Parallel-hole collimator concept for stationary SPECT imaging.

    PubMed

    Pato, Lara R V; Vandenberghe, Stefaan; Zedda, Tiziana; Van Holen, Roel

    2015-11-21

    Parallel-hole SPECT collimators have traditionally been manufactured by stacking sheets of lead foil or by casting. These techniques significantly restrict our options in terms of collimator geometry. However, recent developments in metal additive manufacturing are making novel collimator designs possible, giving rise to new opportunities in SPECT imaging. In this paper we propose an innovative type of collimator for stationary SPECT, using parallel-holes whose collimation direction depends on their axial position. Its main advantage compared to current stationary SPECT systems (which are based on pinholes) is that, using only axial bed translations, we can achieve complete angular sampling of an increased portion of the transaxial area of the collimator bore. This allows the system to be much more compact than current stationary SPECT systems that image objects of the same size. We describe three possible designs, for full-body, brain and small-animal imaging, respectively, and test their feasibility using simulations. The system modeling method is validated against realistic Monte Carlo simulations, and then used in the evaluation of the systems' performances and reconstructions. The simulations show that the system is able to reconstruct objects occupying the predicted field of view ([Formula: see text] of the transaxial area of the bore) without sampling artifacts. In particular, we perform reconstructions from noisy projection data obtained for an activity and scanning time similar to standard protocols for the three applications, and the resulting images indicate the possibility of using the proposed systems in practice. PMID:26528908

  2. Parallel-hole collimator concept for stationary SPECT imaging

    NASA Astrophysics Data System (ADS)

    Pato, Lara R. V.; Vandenberghe, Stefaan; Zedda, Tiziana; Van Holen, Roel

    2015-11-01

    Parallel-hole SPECT collimators have traditionally been manufactured by stacking sheets of lead foil or by casting. These techniques significantly restrict our options in terms of collimator geometry. However, recent developments in metal additive manufacturing are making novel collimator designs possible, giving rise to new opportunities in SPECT imaging. In this paper we propose an innovative type of collimator for stationary SPECT, using parallel-holes whose collimation direction depends on their axial position. Its main advantage compared to current stationary SPECT systems (which are based on pinholes) is that, using only axial bed translations, we can achieve complete angular sampling of an increased portion of the transaxial area of the collimator bore. This allows the system to be much more compact than current stationary SPECT systems that image objects of the same size. We describe three possible designs, for full-body, brain and small-animal imaging, respectively, and test their feasibility using simulations. The system modeling method is validated against realistic Monte Carlo simulations, and then used in the evaluation of the systems’ performances and reconstructions. The simulations show that the system is able to reconstruct objects occupying the predicted field of view (75% of the transaxial area of the bore) without sampling artifacts. In particular, we perform reconstructions from noisy projection data obtained for an activity and scanning time similar to standard protocols for the three applications, and the resulting images indicate the possibility of using the proposed systems in practice.

  3. Tri-modality small animal imaging system

    SciTech Connect

    Kundu, B.K.; Stolin, A.V.; Pole, J.; Baumgart, L.; Fontaine, M.; Wojcik, R.; Kross, B.; Zorn, C.; Majewski, S.; Williams, M.B.

    2006-02-01

    Our group is developing a scanner that combines x-ray, single gamma, and optical imaging on the same rotating gantry. Two functional modalities (SPECT and optical) are included because they have different strengths and weaknesses in terms of spatial and temporal decay lengths in the context of in vivo imaging, and because of the recent advent of multiple reporter gene constructs. The effect of attenuation by biological tissue on the detected intensity of the emitted signal was measured for both gamma and optical imaging. Attenuation by biological tissue was quantified for both the bioluminescent emission of luciferace and for the emission light of the near infrared fluorophore cyanine 5.5, using a fixed excitation light intensity. Experiments were performed to test the feasibility of using either single gamma or x-ray imaging to make depth-dependent corrections to the measured optical signal. Our results suggest that significant improvements in quantitation of optical emission are possible using straightforward correction techniques based on information from other modalities. Development of an integrated scanner in which data from each modality are obtained with the animal in a common configuration will greatly simplify this process.

  4. Evaluation of quantitative accuracy in CZT-based pre-clinical SPECT for various isotopes

    NASA Astrophysics Data System (ADS)

    Park, S.-J.; Yu, A. R.; Kim, Y.-s.; Kang, W.-S.; Jin, S. S.; Kim, J.-S.; Son, T. J.; Kim, H.-J.

    2015-05-01

    In vivo pre-clinical single-photon emission computed tomography (SPECT) is a valuable tool for functional small animal imaging, but several physical factors, such as scatter radiation, limit the quantitative accuracy of conventional scintillation crystal-based SPECT. Semiconductor detectors such as CZT overcome these deficiencies through superior energy resolution. To our knowledge, little scientific information exists regarding the accuracy of quantitative analysis in CZT-based pre-clinical SPECT systems for different isotopes. The aim of this study was to assess the quantitative accuracy of CZT-based pre-clinical SPECT for four isotopes: 201Tl, 99mTc, 123I, and 111In. The quantitative accuracy of the CZT-based Triumph X-SPECT (Gamma-Medica Ideas, Northridge, CA, U.S.A.) was compared with that of a conventional SPECT using GATE simulation. Quantitative errors due to the attenuation and scatter effects were evaluated for all four isotopes with energy windows of 5%, 10%, and 20%. A spherical source containing the isotope was placed at the center of the air-or-water-filled mouse-sized cylinder phantom. The CZT-based pre-clinical SPECT was more accurate than the conventional SPECT. For example, in the conventional SPECT with an energy window of 10%, scatter effects degraded quantitative accuracy by up to 11.52%, 5.10%, 2.88%, and 1.84% for 201Tl, 99mTc, 123I, and 111In, respectively. However, with the CZT-based pre-clinical SPECT, the degradations were only 9.67%, 5.45%, 2.36%, and 1.24% for 201Tl, 99mTc, 123I, and 111In, respectively. As the energy window was increased, the quantitative errors increased in both SPECT systems. Additionally, the isotopes with lower energy of photon emissions had greater quantitative error. Our results demonstrated that the CZT-based pre-clinical SPECT had lower overall quantitative errors due to reduced scatter and high detection efficiency. Furthermore, the results of this systematic assessment quantifying the accuracy of these SPECT

  5. Molecular SPECT Imaging: An Overview

    PubMed Central

    Khalil, Magdy M.; Tremoleda, Jordi L.; Bayomy, Tamer B.; Gsell, Willy

    2011-01-01

    Molecular imaging has witnessed a tremendous change over the last decade. Growing interest and emphasis are placed on this specialized technology represented by developing new scanners, pharmaceutical drugs, diagnostic agents, new therapeutic regimens, and ultimately, significant improvement of patient health care. Single photon emission computed tomography (SPECT) and positron emission tomography (PET) have their signature on paving the way to molecular diagnostics and personalized medicine. The former will be the topic of the current paper where the authors address the current position of the molecular SPECT imaging among other imaging techniques, describing strengths and weaknesses, differences between SPECT and PET, and focusing on different SPECT designs and detection systems. Radiopharmaceutical compounds of clinical as well-preclinical interest have also been reviewed. Moreover, the last section covers several application, of μSPECT imaging in many areas of disease detection and diagnosis. PMID:21603240

  6. Rapid construction of pinhole SPECT system matrices by distance-weighted Gaussian interpolation method combined with geometric parameter estimations

    NASA Astrophysics Data System (ADS)

    Lee, Ming-Wei; Chen, Yi-Chun

    2014-02-01

    In pinhole SPECT applied to small-animal studies, it is essential to have an accurate imaging system matrix, called H matrix, for high-spatial-resolution image reconstructions. Generally, an H matrix can be obtained by various methods, such as measurements, simulations or some combinations of both methods. In this study, a distance-weighted Gaussian interpolation method combined with geometric parameter estimations (DW-GIMGPE) is proposed. It utilizes a simplified grid-scan experiment on selected voxels and parameterizes the measured point response functions (PRFs) into 2D Gaussians. The PRFs of missing voxels are interpolated by the relations between the Gaussian coefficients and the geometric parameters of the imaging system with distance-weighting factors. The weighting factors are related to the projected centroids of voxels on the detector plane. A full H matrix is constructed by combining the measured and interpolated PRFs of all voxels. The PRFs estimated by DW-GIMGPE showed similar profiles as the measured PRFs. OSEM reconstructed images of a hot-rod phantom and normal rat myocardium demonstrated the effectiveness of the proposed method. The detectability of a SKE/BKE task on a synthetic spherical test object verified that the constructed H matrix provided comparable detectability to that of the H matrix acquired by a full 3D grid-scan experiment. The reduction in the acquisition time of a full 1.0-mm grid H matrix was about 15.2 and 62.2 times with the simplified grid pattern on 2.0-mm and 4.0-mm grid, respectively. A finer-grid H matrix down to 0.5-mm spacing interpolated by the proposed method would shorten the acquisition time by 8 times, additionally.

  7. Optimization of an adaptive SPECT system with the scanning linear estimator

    NASA Astrophysics Data System (ADS)

    Ghanbari, Nasrin; Clarkson, Eric; Kupinski, Matthew A.; Li, Xin

    2015-08-01

    The adaptive single-photon emission computed tomography (SPECT) system studied here acquires an initial scout image to obtain preliminary information about the object. Then the configuration is adjusted by selecting the size of the pinhole and the magnification that optimize system performance on an ensemble of virtual objects generated to be consistent with the scout data. In this study the object is a lumpy background that contains a Gaussian signal with a variable width and amplitude. The virtual objects in the ensemble are imaged by all of the available configurations and the subsequent images are evaluated with the scanning linear estimator to obtain an estimate of the signal width and amplitude. The ensemble mean squared error (EMSE) on the virtual ensemble between the estimated and the true parameters serves as the performance figure of merit for selecting the optimum configuration. The results indicate that variability in the original object background, noise and signal parameters leads to a specific optimum configuration in each case. A statistical study carried out for a number of objects show that the adaptive system on average performs better than its nonadaptive counterpart.

  8. A systems approach to animal communication

    PubMed Central

    Barron, Andrew B.; Balakrishnan, Christopher N.; Hauber, Mark E.; Hoke, Kim L.

    2016-01-01

    Why animal communication displays are so complex and how they have evolved are active foci of research with a long and rich history. Progress towards an evolutionary analysis of signal complexity, however, has been constrained by a lack of hypotheses to explain similarities and/or differences in signalling systems across taxa. To address this, we advocate incorporating a systems approach into studies of animal communication—an approach that includes comprehensive experimental designs and data collection in combination with the implementation of systems concepts and tools. A systems approach evaluates overall display architecture, including how components interact to alter function, and how function varies in different states of the system. We provide a brief overview of the current state of the field, including a focus on select studies that highlight the dynamic nature of animal signalling. We then introduce core concepts from systems biology (redundancy, degeneracy, pluripotentiality, and modularity) and discuss their relationships with system properties (e.g. robustness, flexibility, evolvability). We translate systems concepts into an animal communication framework and accentuate their utility through a case study. Finally, we demonstrate how consideration of the system-level organization of animal communication poses new practical research questions that will aid our understanding of how and why animal displays are so complex. PMID:26936240

  9. Correlation between clinical severity of central nervous system (CNS) lupus and findings on single photon emission computed tomographic (SPECT) images of the brain; preliminary results

    SciTech Connect

    Silverman, I.E.; Zeit, R.M.; Von Feldt, J.M.

    1994-05-01

    Systemic Lupus Erythematosis (SLE) commonly causes significant neuropsychiatric disorders. The purpose of this study was to review the brain SPECT studies of SLE patients with clinical evidence of CNS involvement and determine whether there is a correlation between the findings on SPECT images and the clinical manifestations of this serious phase of the disease. We enrolled 19 SLE patients and 12 normal controls in this study. The level of each patient`s disease activity was determined by the SLE Disease Activity Index (SLEDAI), an established method of scoring disease severity which is heavily weighted toward neuropsychiatric symptomatology, for 15 of the 19 SLE patients. The SLEDAI was calculated within a 10 day window of the date when the SPECT scan was obtained. SPECT scans were performed 30 minutes following the intravenous administration of 99mTc-HMPAO. Results are discussed.

  10. Usefulness of three-phase bone scintigraphy and SPECT/CT for the diagnosis of bone lesions of systemic sarcoidosis

    PubMed Central

    Higashiyama, Shigeaki; Kawabe, Joji; Yoshida, Atsushi; Kotani, Kohei; Shiomi, Susumu

    2014-01-01

    We report a three-phase bone scintigraphy for the diagnosis of a peripheral bone lesion caused by systemic sarcoidosis. A 32-year-old man with suspected osteomyelitis of the right forefinger underwent three-phase bone scintigraphy with Tc-99m hydroxymethylene diphosphonate (HMDP) and single-photon emission computed tomography/computed tomography (SPECT/CT). The lesion was rich in blood flow according to flow study and blood pool study on bone scintigraphy, and was associated with an osteolytic change on SPECT/CT imaging performed 3 hours after injection of a radioisotope (RI). Whole-body bone scintigraphy indicated multiple high levels of abnormal RI accumulation. The findings of the three-phase bone scintigraphy and SPECT/CT suggested the presence of systemic sarcoidosis; however, a subsequent 18F-fluorodeoxyglucose positron emission tomography/CT (FDG-PET/CT) could not exclude the possibility of multiple metastases from testicular tumors. Therefore, testicular enucleation was performed, and the pathological examination confirmed the presence of sarcoidosis.

  11. Core systems of geometry in animal minds.

    PubMed

    Spelke, Elizabeth S; Lee, Sang Ah

    2012-10-01

    Research on humans from birth to maturity converges with research on diverse animals to reveal foundational cognitive systems in human and animal minds. The present article focuses on two such systems of geometry. One system represents places in the navigable environment by recording the distance and direction of the navigator from surrounding, extended surfaces. The other system represents objects by detecting the shapes of small-scale forms. These two systems show common signatures across animals, suggesting that they evolved in distant ancestral species. As children master symbolic systems such as maps and language, they come productively to combine representations from the two core systems of geometry in uniquely human ways; these combinations may give rise to abstract geometric intuitions. Studies of the ontogenetic and phylogenetic sources of abstract geometry therefore are illuminating of both human and animal cognition. Research on animals brings simpler model systems and richer empirical methods to bear on the analysis of abstract concepts in human minds. In return, research on humans, relating core cognitive capacities to symbolic abilities, sheds light on the content of representations in animal minds. PMID:22927577

  12. Core systems of geometry in animal minds

    PubMed Central

    Spelke, Elizabeth S.; Lee, Sang Ah

    2012-01-01

    Research on humans from birth to maturity converges with research on diverse animals to reveal foundational cognitive systems in human and animal minds. The present article focuses on two such systems of geometry. One system represents places in the navigable environment by recording the distance and direction of the navigator from surrounding, extended surfaces. The other system represents objects by detecting the shapes of small-scale forms. These two systems show common signatures across animals, suggesting that they evolved in distant ancestral species. As children master symbolic systems such as maps and language, they come productively to combine representations from the two core systems of geometry in uniquely human ways; these combinations may give rise to abstract geometric intuitions. Studies of the ontogenetic and phylogenetic sources of abstract geometry therefore are illuminating of both human and animal cognition. Research on animals brings simpler model systems and richer empirical methods to bear on the analysis of abstract concepts in human minds. In return, research on humans, relating core cognitive capacities to symbolic abilities, sheds light on the content of representations in animal minds. PMID:22927577

  13. FastSPECT II: A Second-Generation High-Resolution Dynamic SPECT Imager

    PubMed Central

    Furenlid, Lars R.; Wilson, Donald W.; Chen, Yi-chun; Kim, Hyunki; Pietraski, Philip J.; Crawford, Michael J.; Barrett, Harrison H.

    2010-01-01

    FastSPECT II is a recently commissioned 16-camera small-animal SPECT imager built with modular scintillation cameras and list-mode data-acquisition electronics. The instrument is housed in a lead-shielded enclosure and has exchangeable aperture assemblies and adjustable camera positions for selection of magnification, pinhole size, and field of view. The calibration of individual cameras and measurement of an overall system imaging matrix (1 mm3 voxels) are supported via a five-axis motion-control system. Details of the system integration and results of characterization and performance measurements are presented along with first tomographic images. The dynamic imaging capabilities of the instrument are explored and discussed. PMID:20877439

  14. Biosynthesis of Fluorescent Bi2S3 Nanoparticles and their Application as Dual-Function SPECT-CT Probe for Animal Imaging.

    PubMed

    Uddin, Imran; Ahmad, Absar; Siddiqui, Ejaz Ahmad; Rahaman, Sk Hasanur; Gambhir, Sanjay

    2016-01-01

    Bismuth sulphide (Bi2S3) is an excellent semiconductor and its nanoparticles have numerous significant applications including photovoltaic materials, photodiode arrays, bio-imaging, etc. Nevertheless, these nanoparticles when fabricated by chemical and physical routes tend to easily aggregate in colloidal solutions, are eco-unfriendly, cumbrous and very broad in size distribution. The aim of the present manuscript was to ecologically fabricate water dispersible, safe and stable Bi2S3 nanoparticles such that these may find use in animal imaging, diagnostics, cell labeling and other biomedical applications. Herein, we for the first time have biosynthesized highly fluorescent, natural protein capped Bi2S3 nanoparticles by subjecting the fungus Fusarium oxysporum to bismuth nitrate pentahydrate [Bi(NO3)3.5H2O] alongwith sodium sulphite (Na2SO3) as precursor salts under ambient conditions of temperature, pressure and pH. The nanoparticles were completely characterized using recognized standard techniques. These natural protein capped Bi2S3 nanoparticles are quasi-spherical in shape with an average particle size of 15 nm, maintain long term stability and show semiconductor behavior having blue shift with a band gap of 3.04 eV. Semiconductor nanocrystals are fundamentally much more fluorescent than the toxic fluorescent chemical compounds (fluorophores) which are presently largely employed in imaging, immunohistochemistry, biochemistry, etc. Biologically fabricated fluorescent nanoparticles may replace organic fluorophores and aid in rapid development of biomedical nanotechnology. Thus, biodistribution study of the so-formed Bi2S3 nanoparticles in male Sprague Dawley rats was done by radiolabelling with Technitium-99m (Tc-99m) and clearance time from blood was calculated. The nanoparticles were then employed in SPECT-CT probe for animal imaging where these imparted iodine equivalent contrast. PMID:26876521

  15. Development of radiodetection systems towards miniaturised quality control of PET and SPECT radiopharmaceuticals.

    PubMed

    Taggart, Matthew P; Tarn, Mark D; Esfahani, Mohammad M N; Schofield, Daniel M; Brown, Nathaniel J; Archibald, Stephen J; Deakin, Tom; Pamme, Nicole; Thompson, Lee F

    2016-04-26

    The ability to detect radiation in microfluidic devices is important for the on-chip analysis of radiopharmaceuticals, but previously reported systems have largely suffered from various limitations including cost, complexity of fabrication, and insufficient sensitivity and/or speed. Here, we present the use of sensitive, low cost, small-sized, commercially available silicon photomultipliers (SiPMs) for the detection of radioactivity inside microfluidic channels fabricated from a range of conventional microfluidic chip substrates. We demonstrate the effects of chip material and thickness on the detection of the positron-emitting isotope, [(18)F]fluoride, and find that, while the SiPMs are light sensors, they are able to detect radiation even through opaque chip materials via direct positron and gamma (γ) ray interaction. Finally, we employed the SiPM platform for analysis of the PET (positron emission tomography) radiotracers 2-[(18)F]fluoro-2-deoxy-d-glucose ([(18)F]FDG) and [(68)Ga]gallium-citrate, and highlight the ability to detect the γ ray emitting SPECT (single photon emission computed tomography) radiotracer, [(99m)Tc]pertechnetate. PMID:27044712

  16. Molecular Imaging of Conscious, Unrestrained Mice with AwakeSPECT

    PubMed Central

    Baba, Justin S.; Endres, Christopher J.; Foss, Catherine A.; Nimmagadda, Sridhar; Jung, Hyeyun; Goddard, James S.; Lee, Seungjoon; McKisson, John; Smith, Mark F.; Stolin, Alexander V.; Weisenberger, Andrew G.; Pomper, Martin G.

    2014-01-01

    We have developed a SPECT imaging system, AwakeSPECT, to enable molecular brain imaging of untrained mice that are conscious, unanesthetized, and unrestrained. We accomplished this with head tracking and motion correction techniques. Methods: The capability of the system for motion-corrected imaging was demonstrated with a 99mTc-pertechnetate phantom, 99mTcmethylene diphosphonate bone imaging, and measurement of the binding potential of the dopamine transporter radioligand 123I-ioflupane in mouse brain in the awake and anesthetized (isoflurane) states. Stress induced by imaging in the awake state was assessed through measurement of plasma corticosterone levels. Results: AwakeSPECT provided high-resolution bone images reminiscent of those obtained from CT. The binding potential of 123I-ioflupane in the awake state was on the order of 50% of that obtained with the animal under anesthesia, consistent with previous studies in nonhuman primates. Levels of stress induced were on the order of those seen in other behavioral tasks and imaging studies of awake animals. Conclusion: These results demonstrate the feasibility of SPECT molecular brain imaging of mice in the conscious, unrestrained state and demonstrate the effects of isoflurane anesthesia on radiotracer uptake. PMID:23536223

  17. Molecular Imaging of Conscious, Unrestrained Mice with AwakeSPECT

    SciTech Connect

    Baba, Justin S.; Endres, Christopher J.; Foss, Catherine A.; Nimmagadda, Sridhar; Jung, Hyeyun; Goddard, James S.; Lee, Seung Joon; McKisson, John; Smith, Mark F.; Stolin, Alexander V.; Weisenberger, Andrew G.; Pomper, Martin G.

    2013-06-01

    We have developed a SPECT imaging system, AwakeSPECT, to enable molecular brain imaging of untrained mice that are conscious, unanesthetized, and unrestrained. We accomplished this with head tracking and motion correction techniques. Methods: The capability of the system for motion-corrected imaging was demonstrated with a ^99mTc-pertechnetate phantom, ^99mTc-methylene diphosphonate bone imaging, and measurement of the binding potential of the dopamine transporter radioligand ^123I-ioflupane in mouse brain in the awake and anesthetized (isoflurane) states. Stress induced by imaging in the awake state was assessed through measurement of plasma corticosterone levels. Results: AwakeSPECT provided high-resolution bone images reminiscent of those obtained from CT. The binding potential of ^123I-ioflupane in the awake state was on the order of 50% of that obtained with the animal under anesthesia, consistent with previous studies in nonhuman primates. Levels of stress induced were on the order of those seen in other behavioral tasks and imaging studies of awake animals. Conclusion: These results demonstrate the feasibility of SPECT molecular brain imaging of mice in the conscious, unrestrained state and demonstrate the effects of isoflurane anesthesia on radiotracer uptake.

  18. Molecular Imaging of Conscious, Unrestrained Mice with AwakeSPECT

    SciTech Connect

    Baba, Justin S; Endres, Christopher; Foss, Catherine; Nimmagadda, Sridhar; Jung, Hyeyun; Goddard Jr, James Samuel; Lee, Seung Joon; McKisson, John; Smith, Mark F.; Stolin, Alexander; Weisenberger, Andrew G.; Pomper, Martin

    2013-01-01

    We have developed a SPECT imaging system, AwakeSPECT, to enable molecular brain imaging of untrained mice that are conscious, unanesthetized, and unrestrained. We accomplished this with head tracking and motion correction techniques. Methods: The capability of the system for motion-corrected imaging was demonstrated with a 99mTc-pertechnetate phantom, 99mTcmethylene diphosphonate bone imaging, and measurement of the binding potential of the dopamine transporter radioligand 123I-ioflupane in mouse brain in the awake and anesthetized (isoflurane) states. Stress induced by imaging in the awake state was assessed through measurement of plasma corticosterone levels. Results: AwakeSPECT provided high-resolution bone images reminiscent of those obtained from CT. The binding potential of 123I-ioflupane in the awake state was on the order of 50% of that obtained with the animal under anesthesia, consistent with previous studies in nonhuman primates. Levels of stress induced were on the order of those seen in other behavioral tasks and imaging studies of awake animals. Conclusion: These results demonstrate the feasibility of SPECT molecular brain imaging of mice in the conscious, unrestrained state and demonstrate the effects of isoflurane anesthesia on radiotracer uptake.

  19. Do Animal Communication Systems Have Phonemes?

    PubMed

    Bowling, Daniel L; Fitch, W Tecumseh

    2015-10-01

    Biologists often ask whether animal communication systems make use of conceptual entities from linguistics, such as semantics or syntax. A new study of an Australian bird species argues that their communication system has phonemes, but we argue that imposing linguistic concepts obscures, rather than clarifyies, communicative function. PMID:26346993

  20. The SPECT imaging shows the accumulation of neural progenitor cells into internal organs after systemic administration in middle cerebral artery occlusion rats.

    PubMed

    Lappalainen, Riikka S; Narkilahti, Susanna; Huhtala, Tuulia; Liimatainen, Timo; Suuronen, Tiina; Närvänen, Ale; Suuronen, Riitta; Hovatta, Outi; Jolkkonen, Jukka

    2008-08-01

    The regenerative potential of stem cells from various sources has been under intense investigation in the experimental models of cerebral ischemia. To end up with a restorative therapeutic treatment, it is crucial to get the cell transplants to the site of injury. Here, we evaluated the feasibility of small animal SPECT/CT in assessing the definite accumulation of (111)In-oxine-labeled human embryonic stem (ES) cell-derived neural progenitors and rat hippocampal progenitors after intravenous or intra-arterial administration (femoral vein vs. common carotid artery) in middle cerebral artery occlusion (MCAO) and sham-operated rats. Cell detection was carried out immediately and 24h after the infusion using a SPECT/CT device. The results showed that after intravenous injections both cell types accumulated primarily into internal organs, instead of brain. In contrast, after intra-arterial injection, a weak signal was detected in the ischemic hemisphere. Additional studies showed that the detection sensitivity of SPECT/CT device was approximately 1000 (111)In-oxine-labeled cells and labeling did not affect the cell viability. In conclusion, a small animal SPECT is powerful technique to study the whole body biodistribution of cell-based therapies. Our data showed that intravenous administration is not an optimal route to deliver neural progenitor cell-containing transplants into the brain after MCAO in rats. PMID:18572314

  1. Innovative ventilation system for animal anatomy laboratory

    SciTech Connect

    Lacey, D.R.; Smith, D.C.

    1997-04-01

    A unique ventilation system was designed and built to reduce formaldehyde fumes in the large animal anatomy lab at the Vet Medical Center at Cornell University. The laboratory includes four rooms totaling 5,500 ft{sup 2}. The main room has 2,300 ft{sup 2} and houses the laboratory where up to 60 students dissect as many as 12 horses at a time. Other rooms are a cold storage locker, an animal preparation room and a smaller lab for specialized instruction. The large animal anatomy laboratory has a history of air quality complaints despite a fairly high ventilation rate of over 10 air changes/hour. The horses are embalmed, creating a voluminous source of formaldehyde and phenol vapors. Budget constraints and increasingly stringent exposure limits for formaldehyde presented a great challenge to design a ventilation system that yields acceptable air quality. The design solution included two innovative elements: air-to-air heat recovery, and focused ventilation.

  2. MO-G-17A-02: Computer Simulation Studies for On-Board Functional and Molecular Imaging of the Prostate Using a Robotic Multi-Pinhole SPECT System

    SciTech Connect

    Cheng, L; Bowsher, J; Yin, F; Yan, S

    2014-06-15

    Purpose: To investigate prostate imaging onboard radiation therapy machines using a novel robotic, 49-pinhole Single Photon Emission Computed Tomography (SPECT) system. Methods: Computer-simulation studies were performed for region-of-interest (ROI) imaging using a 49-pinhole SPECT collimator and for broad cross-section imaging using a parallel-hole SPECT collimator. A male XCAT phantom was computersimulated in supine position with one 12mm-diameter tumor added in the prostate. A treatment couch was added to the phantom. Four-minute detector trajectories for imaging a 7cm-diameter-sphere ROI encompassing the tumor were investigated with different parameters, including pinhole focal length, pinhole diameter and trajectory starting angle. Pseudo-random Poisson noise was included in the simulated projection data, and SPECT images were reconstructed by OSEM with 4 subsets and up to 10 iterations. Images were evaluated by visual inspection, profiles, and Root-Mean- Square-Error (RMSE). Results: The tumor was well visualized above background by the 49-pinhole SPECT system with different pinhole parameters while it was not visible with parallel-hole SPECT imaging. Minimum RMSEs were 0.30 for 49-pinhole imaging and 0.41 for parallelhole imaging. For parallel-hole imaging, the detector trajectory from rightto- left yielded slightly lower RMSEs than that from posterior to anterior. For 49-pinhole imaging, near-minimum RMSEs were maintained over a broader range of OSEM iterations with a 5mm pinhole diameter and 21cm focal length versus a 2mm diameter pinhole and 18cm focal length. The detector with 21cm pinhole focal length had the shortest rotation radius averaged over the trajectory. Conclusion: On-board functional and molecular prostate imaging may be feasible in 4-minute scan times by robotic SPECT. A 49-pinhole SPECT system could improve such imaging as compared to broadcross-section parallel-hole collimated SPECT imaging. Multi-pinhole imaging can be improved by

  3. [PET and SPECT in epilepsy].

    PubMed

    Setoain, X; Carreño, M; Pavía, J; Martí-Fuster, B; Campos, F; Lomeña, F

    2014-01-01

    Epilepsy is one of the most frequent chronic neurological disorders, affecting 1-2% of the population. Patients with complex partial drug resistant episodes may benefit from a surgical treatment consisting in the excision of the epileptogenic area. Localization of the epileptogenic area was classically performed with video-EEG and magnetic resonance (MR). Recently, functional neuroimaging studies of Nuclear Medicine, positron emission tomography (PET) and single photon emission tomography (SPECT) have demonstrated their utility in the localization of the epileptogenic area prior to surgery. Ictal SPECT with brain perfusion tracers show an increase in blood flow in the initial ictal focus, while PET with (18)FDG demonstrates a decrease of glucose metabolism in the interictal functional deficit zone. In this review, the basic principles and methodological characteristics of the SPECT and PET in epilepsy are described. The ictal SPECT injection mechanism, different patterns of perfusion based on the time of ictal, postictal or interictal injection are detailed and the different diagnostic sensitivities of each one of these SPECT are reviewed. Different methods of analysis of the images with substraction and fusion systems with the MR are described. Similarly, the injection methodology, quantification and evaluation of the images of the PET in epilepsy are described. Finally, the main clinical indications of SPECT and PET in temporal and extratemporal epilepsy are detailed. PMID:24565567

  4. The design and clinical utilities of a fan beam collimator for a SPECT system

    SciTech Connect

    Tsui, B.M.W.; Gullberg, G.T.; Edgerton, E.R.; Gilland, D.R.; Rho, T.; Johnston, R.E.; Perry, J.R.; McCartney, W.H.

    1984-01-01

    A low-energy fan-beam collimator (LEFB) designed for SPECT imaging of the head was evaluated using physical measurements, phantom and clinical studies. In the transverse image plane, the collimator holes are tapered and converged to a focal point 58 cm from the collimator face. In the longitudinal image plane, the collimator holes are straight and parallel. The collimator holes are hexagonal in shape and 13 cm in length. The extended hole design allows improved clearance of the patient's shoulders during rotation such that the collimator face may be positioned 8.5 cm closer to the patient's head than is possible with conventional collimators. At the center of rotation with the closest rotational radius, the spatial resolutions for the LEGP, LEHR, and LEFB collimators are 17.0, 14.4 and 12.2 mm, respectively. The point source sensitivities are 330, 220 and 190 (at 15 cm) cpm/..mu..Ci, respectively. Line spread functions at various distances from the collimator face, both in air and in water, were measured. Reconstruction algorithms and a special attenuation correction method for the fan beam geometry were developed and various reconstruction parameters for the LEFB collimator were determined experimentally. Images of a SPECT phantom were obtained to evaluate the imaging capabilities of the LEFB collimator and the reconstruction algorithm. Clinical comparison of SPECT bone images of the temporomandibular joints obtained with both LEGP and LEFB collimators on the same patients show superior image quality with the LEFB collimator.

  5. PET and SPECT imaging of the opioid system: receptors, radioligands and avenues for drug discovery and development.

    PubMed

    Lever, John R

    2007-01-01

    As we celebrate the bicentennial of the isolation of morphine by Sertürner, opioids continue to dominate major sectors of the analgesic market worldwide. The pharmaceutical industry stands to benefit greatly from molecular imaging in preclinical and early clinical trials of new or improved opioid drugs. At this juncture, it seems fitting to summarize the past twenty or so years of research on molecular imaging of the opioid system from the viewpoint of drug discovery and development. Opioid receptors were first imaged in human volunteers by positron emission tomography (PET) in 1984. Now, quantitative PET imaging of the major opioid receptor types (micro, delta , kappa) is possible in the brain and peripheral organs of healthy persons and patient populations. Radioligands are under development for single photon emission computed tomography (SPECT) of opioid receptors as well. These functional, nuclear imaging techniques can trace the fate of radiolabeled molecules directly, but non-invasively, and allow precise pharmacokinetic and pharmacodynamic measurements. Molecular imaging provides unique data that can aid in selecting the best drug candidates, determining optimal dosing regimens, clearing regulatory hurdles and lowering risks of failure. Using a historical perspective, this review touches on opioid receptors as drug targets, and focuses on the status and use of radiotracers for opioid receptor PET and SPECT. Selected studies are discussed to illustrate the power of molecular imaging for facilitating opioid drug discovery and development. PMID:17266587

  6. A guide to SPECT equipment for brain imaging

    SciTech Connect

    Hoffer, P.B.; Zubal, G.

    1991-12-31

    Single photon emission computed tomography (SPECT) was started by Kuhl and Edwards about 30 years ago. Their original instrument consisted of four focused Nal probes mounted on a moving gantry. During the 1980s, clinical SPECT imaging was most frequently performed using single-headed Anger-type cameras which were modified for rotational as well as static imaging. Such instruments are still available and may be useful in settings where there are few patients and SPECT is used only occasionally. More frequently, however, dedicated SPECT devices are purchased which optimize equipment potential while being user-friendly. Modern SPECT instrumentation incorporates improvements in the detector, computers, mathematical formulations, electronics and display systems. A comprehensive discussion of all aspects of SPECT is beyond the scope of this article. The authors, however, discuss general concepts of SPECT, the current state-of-the-art in clinical SPECT instrumentation, and areas of common misunderstanding. 9 refs.

  7. A Point-Scoring System for the Clinical Diagnosis of Sjögren's Syndrome Based on Quantified SPECT Imaging of Salivary Gland

    PubMed Central

    Chen, Jing; Zhao, Xia; Liu, Haixia; Zhou, Sheng; Yang, Yunqiang; Li, Shouxin; Xianyu, Zhiqun; Han, Yunfeng; Shen, Guifen; Li, Jinming; Ye, Cong; Sun, Wei; Dong, Lingli

    2016-01-01

    Objective To establish a point-scoring diagnostic system for Sjögren's syndrome (SS) based on quantified SPECT imaging of salivary gland, and evaluate its feasibility and performance compared with 2002 AECG criteria and 2012 ACR criteria. Methods 213 patients with suspected SS enrolled in this study. The related clinical data of all patients were collected. All patients were evaluated and grouped on a clinical basis and posttreatment follow-up by rheumatology specialists as the unified standard (SS group with 149 cases and nSS group with 64 cases). From SPECT imaging of salivary gland, Tmax, UImax, Ts and EFs were derived for bilateral parotid and submandibular glands, and compared between the groups. A point-scoring diagnostic system for SS was established based on the quantified SPECT imaging of salivary gland. We estimated the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy for the new diagnostic system, compared with 2002 AECG criteria and 2012 ACR criteria. Results When 7.0 was used as the cut-off point, the sensitivity, specificity, PPV, NPV and accuracy for the new point-scoring system in diagnosing SS were 89.93% (134/149), 93.75% (60/64), 97.10% (134/138), 80.00% (60/75) and 91.08% (194/213), respectively. The new point-scoring diagnostic system based on quantified SPECT imaging of salivary gland keeps the specificity comparatively to 2002 AECG criteria and 2012 ACR criteria, but improves the sensitivity significantly (P<0.01). Conclusion The new point-scoring diagnostic system for SS based on quantified SPECT imaging of salivary gland may be superior to 2002 AECG criteria and 2012 ACR criteria, with higher sensitivity and similar specificity in the diagnosis of SS. Additionally, it also has good feasibility in the clinical settings. PMID:27195488

  8. SU-E-I-79: Effect of Number of Pinholes in Onboard Robotic Multi-Pinhole SPECT System

    SciTech Connect

    Touch, M; Bowsher, J; Yan, S; Yin, F

    2014-06-01

    Purpose: To study the effect of number of pinholes for a novel Single Photon Emission Computed Tomography (SPECT) system for onboard molecular and functional imaging. Methods: Comparison studies were performed using simulation for the 49-pinhole SPECT system and a series of reductions in number of pinholes. Trajectories about the breast of a supine patient were considered. Minimum distances, radii of rotation (RORs), were determined by requirements to fully view the region of interest (ROI) and to avoid collision between the detector and the patient. Reductions in RORs translate into improvements in sensitivity. Starting from the 49-pinhole system, pinholes were removed pod by pod. The furthest two end pods in the Sup-Inf direction were removed first for their higher likelihood of alleviating the collision avoidance criteria. After iterating through different combinations of pinhole pods, and selecting three combinations, the corresponding RORs were used to analytically calculate sensitivities. Results: Based on the Methods procedure, 3 combination of pods removal were identified: 1) Superior peripheral pod 2) Inferior peripheral pod 3) both pods. RORs were reduced at only one multi-pinhole stop. Analytic calculation showed that sensitivities were reduced from 0.032 for the 49-pinhole system to 0.028 for 42-pinhole and to 0.023 for 39-pinhole system respectively. The sensitivity per pinhole detector was approximately the same for all three cases. Conclusion: For the trajectories considered, only minimal improvements in RORs were identified by removing pinhole pods. Consequently, sensitivities decreased in proportion to the number of pinholes. Studies of other anatomical sites are needed to determine if in some cases sensitivity per pinhole can be improved by removing some pinholes. PHS/NIH/NCI grant R21-CA156390-01A1.

  9. Simulation of the expected performance of INSERT: A new multi-modality SPECT/MRI system for preclinical and clinical imaging

    NASA Astrophysics Data System (ADS)

    Busca, P.; Fiorini, C.; Butt, A. D.; Occhipinti, M.; Peloso, R.; Quaglia, R.; Schembari, F.; Trigilio, P.; Nemeth, G.; Major, P.; Erlandsson, K.; Hutton, B. F.

    2014-01-01

    A new multi-modality imaging tool is under development in the framework of the INSERT (INtegrated SPECT/MRI for Enhanced Stratification in Radio-chemo Therapy) project, supported by the European Community. The final goal is to develop a custom SPECT apparatus, that can be used as an insert for commercially available MRI systems such as 3 T MRI with 59 cm bore diameter. INSERT is expected to offer more effective and earlier diagnosis with potentially better outcome in survival for the treatment of brain tumors, primarily glioma. Two SPECT prototypes will be developed, one dedicated to preclinical imaging, the second one dedicated to clinical imaging. The basic building block of the SPECT detector ring is a small 5 cm×5 cm gamma camera, based on the well-established Anger architecture with a continuous scintillator readout by an array of silicon photodetectors. Silicon Drift Detectors (SDDs) and Silicon PhotoMultipliers (SiPM) are being considered as possible scintillator readout, considering that the detector choice plays a predominant role for the final performance of the system, such as energy and spatial resolution, as well as the useful field of view of the camera. Both solutions are therefore under study to evaluate their performances in terms of field of view (FOV), spatial and energy resolution. Preliminary simulations for both the preclinical and clinical systems have been carried out to evaluate resolution and sensitivity.

  10. Theory and realization of a 2D high resolution and high sensitivity SPECT system with an angle-encoding attenuator pattern

    NASA Astrophysics Data System (ADS)

    Feng, Tao; Wang, Jizhe; Tsui, Benjamin M. W.

    2016-04-01

    The camera of the conventional SPECT system requires a collimator to allow incoming photons from a specific range of incident angle to reach the detector. It is the major factor that determines the spatial resolution of the camera. Moreover, it also greatly reduces the number of detected photons and hence increases statistical fluctuations in the acquired image data. The goal of this paper is to propose a theory and design for a novel high resolution and high sensitivity SPECT system without conventional collimators. The key is to resolve the incident photons from all directional angles and detected by every detector bin. Special ‘attenuators’ were designed to ‘encode’ the incoming photons from different directions similar to coded aperture to form projection data for image reconstruction. Each encoded angular pattern of detected photons was recorded as one measurement. Different angular patterns were achieved by changing the configurations of the attenuators so that angular pattern of different measurements or measurement matrix (MM) is invertible, which guarantee a unique reconstructed image. In simulation, the attenuators were fitted on a virtual full-ring gamma camera, as an alternative to the collimators in conventional SPECT systems. To evaluate the performance of the new SPECT system, analytical simulated projection data in 2D scenario were generated from the XCAT phantom. Noisy simulation using 100 noise realizations suggests that the new attenuator design provides much improved image quality in terms of contrast-noise trade-offs (~30% improvement). The results suggest that the new design of using attenuators to replace collimator is feasible and could potentially improve sensitivity without sacrificing resolution in today’s SPECT systems.

  11. Theory and realization of a 2D high resolution and high sensitivity SPECT system with an angle-encoding attenuator pattern.

    PubMed

    Feng, Tao; Wang, Jizhe; Tsui, Benjamin M W

    2016-04-01

    The camera of the conventional SPECT system requires a collimator to allow incoming photons from a specific range of incident angle to reach the detector. It is the major factor that determines the spatial resolution of the camera. Moreover, it also greatly reduces the number of detected photons and hence increases statistical fluctuations in the acquired image data. The goal of this paper is to propose a theory and design for a novel high resolution and high sensitivity SPECT system without conventional collimators. The key is to resolve the incident photons from all directional angles and detected by every detector bin. Special 'attenuators' were designed to 'encode' the incoming photons from different directions similar to coded aperture to form projection data for image reconstruction. Each encoded angular pattern of detected photons was recorded as one measurement. Different angular patterns were achieved by changing the configurations of the attenuators so that angular pattern of different measurements or measurement matrix (MM) is invertible, which guarantee a unique reconstructed image. In simulation, the attenuators were fitted on a virtual full-ring gamma camera, as an alternative to the collimators in conventional SPECT systems. To evaluate the performance of the new SPECT system, analytical simulated projection data in 2D scenario were generated from the XCAT phantom. Noisy simulation using 100 noise realizations suggests that the new attenuator design provides much improved image quality in terms of contrast-noise trade-offs (~30% improvement). The results suggest that the new design of using attenuators to replace collimator is feasible and could potentially improve sensitivity without sacrificing resolution in today's SPECT systems. PMID:26976649

  12. Integration of SimSET photon history generator in GATE for efficient Monte Carlo simulations of pinhole SPECT

    PubMed Central

    Chen, Chia-Lin; Wang, Yuchuan; Lee, Jason J. S.; Tsui, Benjamin M. W.

    2008-01-01

    The authors developed and validated an efficient Monte Carlo simulation (MCS) workflow to facilitate small animal pinhole SPECT imaging research. This workflow seamlessly integrates two existing MCS tools: simulation system for emission tomography (SimSET) and GEANT4 application for emission tomography (GATE). Specifically, we retained the strength of GATE in describing complex collimator∕detector configurations to meet the anticipated needs for studying advanced pinhole collimation (e.g., multipinhole) geometry, while inserting the fast SimSET photon history generator (PHG) to circumvent the relatively slow GEANT4 MCS code used by GATE in simulating photon interactions inside voxelized phantoms. For validation, data generated from this new SimSET-GATE workflow were compared with those from GATE-only simulations as well as experimental measurements obtained using a commercial small animal pinhole SPECT system. Our results showed excellent agreement (e.g., in system point response functions and energy spectra) between SimSET-GATE and GATE-only simulations, and, more importantly, a significant computational speedup (up to ∼10-fold) provided by the new workflow. Satisfactory agreement between MCS results and experimental data were also observed. In conclusion, the authors have successfully integrated SimSET photon history generator in GATE for fast and realistic pinhole SPECT simulations, which can facilitate research in, for example, the development and application of quantitative pinhole and multipinhole SPECT for small animal imaging. This integrated simulation tool can also be adapted for studying other preclinical and clinical SPECT techniques. PMID:18697552

  13. The Roles of Mental Animations and External Animations in Understanding Mechanical Systems

    ERIC Educational Resources Information Center

    Hegarty, Mary; Kriz, Sarah; Cate, Christina

    2003-01-01

    The effects of computer animations and mental animation on people's mental models of a mechanical system are examined. In 3 experiments, students learned how a mechanical system works from various instructional treatments including viewing a static diagram of the machine, predicting motion from static diagrams, viewing computer animations, and…

  14. Rugged Video System For Inspecting Animal Burrows

    NASA Technical Reports Server (NTRS)

    Triandafils, Dick; Maples, Art; Breininger, Dave

    1992-01-01

    Video system designed for examining interiors of burrows of gopher tortoises, 5 in. (13 cm) in diameter or greater, to depth of 18 ft. (about 5.5 m), includes video camera, video cassette recorder (VCR), television monitor, control unit, and power supply, all carried in backpack. Polyvinyl chloride (PVC) poles used to maneuver camera into (and out of) burrows, stiff enough to push camera into burrow, but flexible enough to bend around curves. Adult tortoises and other burrow inhabitants observable, young tortoises and such small animals as mice obscured by sand or debris.

  15. SPECT imaging with resolution recovery

    SciTech Connect

    Bronnikov, A. V.

    2011-07-01

    Single-photon emission computed tomography (SPECT) is a method of choice for imaging spatial distributions of radioisotopes. Many applications of this method are found in nuclear industry, medicine, and biomedical research. We study mathematical modeling of a micro-SPECT system by using a point-spread function (PSF) and implement an OSEM-based iterative algorithm for image reconstruction with resolution recovery. Unlike other known implementations of the OSEM algorithm, we apply en efficient computation scheme based on a useful approximation of the PSF, which ensures relatively fast computations. The proposed approach can be applied with the data acquired with any type of collimators, including parallel-beam fan-beam, cone-beam and pinhole collimators. Experimental results obtained with a micro SPECT system demonstrate high efficiency of resolution recovery. (authors)

  16. SPECT brain imaging of the dopaminergic system in Parkinsonism using {sup 123}I and {sup 99m}Tc labeled agents

    SciTech Connect

    Du Yong

    2004-12-01

    SPECT brain imaging of the dopaminergic system using {sup 123}I and {sup 99m}Tc labeled agents, especially the simultaneous imaging of both pre- and postsynaptic neurons, promises to provide accurate diagnosis and differentiation of Parkinsonism. However, there are many degrading factors that affect the quality and quantitative accuracy of the SPECT images. These degrading factors limit the potential clinical applications of brain SPECT imaging. In this work, we studied these degrading factors by developing and validating a Monte Carlo (MC) method that provides accurate SPECT simulation with detailed modeling of the photon interactions inside the collimator detector system. To compensate for the partial volume effect (PVE) in the SPECT images caused by finite spatial resolution, we developed a new PVE compensation method that takes into account the effects of nonlinearity in iterative reconstruction-based compensation for image degrading factors, including attenuation, scatter, and collimator detector response. Compensation using the new method greatly improved the quantitative accuracy of brain SPECT images. We have also developed model-based method that can accurately estimate the downscatter and crosstalk contamination in the {sup 123}I imaging and the simultaneous {sup 123}I/{sup 99m}Tc dual-isotope imaging. Based on the model-based method, two different approaches to model-based downscatter and crosstalk contamination compensation were proposed. Both methods are based on iterative reconstruction and include compensation for other imaging degrading factors. The model-based downscatter and crosstalk compensation method provided greatly improved accuracy of activity estimates with little effect on the precision. Finally, optimization of energy windows for simultaneous {sup 123}I/{sup 99m}Tc acquisition was performed to find the energy windows with the best trade-off between minimizing the crosstalk and maximizing the detection efficiency for simultaneous

  17. SPECT/CT and pulmonary embolism.

    PubMed

    Mortensen, Jann; Gutte, Henrik

    2014-05-01

    Acute pulmonary embolism (PE) is diagnosed either by ventilation/perfusion (V/P) scintigraphy or pulmonary CT angiography (CTPA). In recent years both techniques have improved. Many nuclear medicine centres have adopted the single photon emission CT (SPECT) technique as opposed to the planar technique for diagnosing PE. SPECT has been shown to have fewer indeterminate results and a higher diagnostic value. The latest improvement is the combination of a low-dose CT scan with a V/P SPECT scan in a hybrid tomograph. In a study comparing CTPA, planar scintigraphy and SPECT alone, SPECT/CT had the best diagnostic accuracy for PE. In addition, recent developments in the CTPA technique have made it possible to image the pulmonary arteries of the lungs in one breath-hold. This development is based on the change from a single-detector to multidetector CT technology with an increase in volume coverage per rotation and faster rotation. Furthermore, the dual energy CT technique is a promising modality that can provide functional imaging in combination with anatomical information. Newer high-end CT scanners and SPECT systems are able to visualize smaller subsegmental emboli. However, consensus is lacking regarding the clinical impact and treatment. In the present review, SPECT and SPECT in combination with low-dose CT, CTPA and dual energy CT are discussed in the context of diagnosing PE. PMID:24213621

  18. Animal biocalorimeter and waste management system

    NASA Technical Reports Server (NTRS)

    Poppendiek, Heinz F. (Inventor); Trimailo, William R. (Inventor)

    1995-01-01

    A biocalorimeter and waste management system is provided for making metabolic heat release measurements of animals or humans in a calorimeter (enclosure) using ambient air as a low velocity source of ventilating air through the enclosure. A shroud forces ventilating air to pass over the enclosure from an end open to ambient air at the end of the enclosure opposite its ventilating air inlet end and closed around the inlet end of the enclosure in order to obviate the need for regulating ambient air temperature. Psychrometers for measuring dry- and wet-bulb temperature of ventilating air make it possible to account for the sensible and latent heat additions to the ventilating air. A waste removal system momentarily recirculates high velocity air in a closed circuit through the calorimeter wherein a sudden rise in moisture is detected in the ventilating air from the outlet.

  19. The AdaptiSPECT Imaging Aperture

    PubMed Central

    Chaix, Cécile; Moore, Jared W.; Van Holen, Roel; Barrett, Harrison H.; Furenlid, Lars R.

    2015-01-01

    In this paper, we present the imaging aperture of an adaptive SPECT imaging system being developed at the Center for Gamma Ray Imaging (AdaptiSPECT). AdaptiSPECT is designed to automatically change its configuration in response to preliminary data, in order to improve image quality for a particular task. In a traditional pinhole SPECT imaging system, the characteristics (magnification, resolution, field of view) are set by the geometry of the system, and any modification can be accomplished only by manually changing the collimator and the distance of the detector to the center of the field of view. Optimization of the imaging system for a specific task on a specific individual is therefore difficult. In an adaptive SPECT imaging system, on the other hand, the configuration can be conveniently changed under computer control. A key component of an adaptive SPECT system is its aperture. In this paper, we present the design, specifications, and fabrication of the adaptive pinhole aperture that will be used for AdaptiSPECT, as well as the controls that enable autonomous adaptation. PMID:27019577

  20. Quantitative SPECT/CT: SPECT joins PET as a quantitative imaging modality.

    PubMed

    Bailey, Dale L; Willowson, Kathy P

    2014-05-01

    The introduction of combined modality single photon emission computed tomography (SPECT)/CT cameras has revived interest in quantitative SPECT. Schemes to mitigate the deleterious effects of photon attenuation and scattering in SPECT imaging have been developed over the last 30 years but have been held back by lack of ready access to data concerning the density of the body and photon transport, which we see as key to producing quantitative data. With X-ray CT data now routinely available, validations of techniques to produce quantitative SPECT reconstructions have been undertaken. While still suffering from inferior spatial resolution and sensitivity compared to positron emission tomography (PET) imaging, SPECT scans nevertheless can be produced that are as quantitative as PET scans. Routine corrections are applied for photon attenuation and scattering, resolution recovery, instrumental dead time, radioactive decay and cross-calibration to produce SPECT images in units of kBq.ml(-1). Though clinical applications of quantitative SPECT imaging are lacking due to the previous non-availability of accurately calibrated SPECT reconstructions, these are beginning to emerge as the community and industry focus on producing SPECT/CT systems that are intrinsically quantitative. PMID:24037503

  1. SPECT Imaging: Basics and New Trends

    NASA Astrophysics Data System (ADS)

    Hutton, Brian F.

    Single Photon Emission Computed Tomography (SPECT) is widely used as a means of imaging the distribution of administered radiotracers that have single-photon emission. The most widely used SPECT systems are based on the Anger gamma camera, usually involving dual detectors that rotate around the patient. Several factors affect the quality of SPECT images (e.g., resolution and noise) and the ability to perform absolute quantification (e.g., attenuation, scatter, motion, and resolution). There is a trend to introduce dual-modality systems and organ-specific systems, both developments that enhance diagnostic capability.

  2. SRS Computer Animation and Drive Train System

    NASA Technical Reports Server (NTRS)

    Arthun, Daniel; Schachner, Christian

    2001-01-01

    The spinning rocket simulator (SRS) is an ongoing project at Oral Roberts University. The goal of the SRS is to gather crucial data concerning a spinning rocket under thrust for the purpose of analysis and correction of the coning motion experienced by this type of spacecraft maneuver. The computer animation simulates a virtual, scale model of the component of the SRS that represents the spacecraft itself. This component is known as the (VSM), or virtual spacecraft model. During actual physical simulation, this component of the SRS will experience a coning. The goal of the animation is to cone the VSM within that range to accurately represent the motion of the actual simulator. The drive system of the SRS is the apparatus that turns the actual simulator. It consists of a drive motor, motor mount and chain to power the simulator into motion. The motor mount is adjustable and rigid for high torque application. A digital stepper motor controller actuates the main drive motor for linear acceleration. The chain transfers power from the motor to the simulator via sprockets on both ends.

  3. Systematic evaluation of 99mTc-tetrofosmin versus 99mTc-sestamibi to study murine myocardial perfusion in small animal SPECT/CT

    PubMed Central

    2012-01-01

    Background The “back-translation” of clinically available protocols to measure myocardial perfusion to preclinical imaging in mouse models of human disease is attractive for basic biomedical research. With respect to single-photon emission computed tomography (SPECT) approaches, clinical myocardial perfusion imaging protocols are established with different 99mTc-labeled perfusion tracers; however, studies evaluating and optimizing protocols for these tracers in high-resolution pinhole SPECT in mice are lacking. This study aims at evaluating two clinically available 99mTc-labeled myocardial perfusion tracers (99mTc-sestamibi vs. 99mTc-Tetrofosmin) in mice using four different imaging protocols. Methods Adult C57BL/6 male mice were injected with 99mTc-sestamibi (MIBI) or 99mTc-Tetrofosmin (TETRO) (4 MBq/g body weight) either intravenously through the tail vein (n = 5) or retroorbitally (n = 5) or intraperitoneally (i.p.) under anesthesia (n = 3) or i.p. in an awake state (n = 3) at rest. Immediately after injection, a multi-frame single-photon emission computed tomography/computed tomography (SPECT/CT) acquisition was initiated with six subsequent time frames of 10 min each. Reconstructed images of the different protocols were assessed and compared by visual analysis by experts and by time-activity-curves generated from regions-of-interest for various organs (normalized uptake values). Results Visually assessing overall image quality, the best image quality was found for MIBI for both intravenous injection protocols, whereas TETRO only had comparable image quality after retroorbital injections. These results were confirmed by quantitative analysis where left ventricular (LV) uptake of MIBI after tail vein injections was found significantly higher for all time points accompanied with a significantly slower washout of 16% for MIBI vs. 33% for TETRO (p = 0.009) from 10 to 60 min post injection (PI). Interestingly, LV washout from 10 to 60 min PI

  4. Progress In The Development Of A Tomographic SPECT System For Online Dosimetry In BNCT

    NASA Astrophysics Data System (ADS)

    Minsky, D. M.; Valda, A.; Kreiner, A. J.; Burlon, A. A.; Green, S.; Wojnecki, C.; Ghani, Z.

    2010-08-01

    In boron neutron capture therapy (BNCT) the delivered dose to the patient depends both on the neutron beam characteristics and on the 10B body distribution which, in turn, is governed by the tumor specificity of the 10B drug-carrier. BNCT dosimetry is a complex matter due to the several interactions that neutrons can undergo with the different nuclei present in tissue. However the boron capture reaction 10B(n,α)7Li accounts for about 80 % of the total dose in a tumor with 40 ppm in 10B concentration. Present dosimetric methods are indirect, based on drug biodistribution statistical data and subjected to inter and intra-patient variability. In order to overcome the consequences of the concomitant high dosimetric uncertainties, we propose a SPECT (Single Photon Emission Tomography) approach based on the detection of the prompt gamma-ray (478 keV) emitted in 94 % of the cases from 7Li. For this purpose we designed, built and tested a prototype based on LaBr3(Ce) scintillators. Measurements on a head and tumor phantom were performed in the accelerator-based BNCT facility of the University of Birmingham (UK). They result in the first tomographic image of the 10B capture distribution obtained in a BNCT facility.

  5. Progress In The Development Of A Tomographic SPECT System For Online Dosimetry In BNCT

    SciTech Connect

    Minsky, D. M.; Kreiner, A. J.; Valda, A.; Burlon, A. A.; Green, S.; Wojnecki, C.; Ghani, Z.

    2010-08-04

    In boron neutron capture therapy (BNCT) the delivered dose to the patient depends both on the neutron beam characteristics and on the {sup 10}B body distribution which, in turn, is governed by the tumor specificity of the {sup 10}B drug-carrier. BNCT dosimetry is a complex matter due to the several interactions that neutrons can undergo with the different nuclei present in tissue. However the boron capture reaction {sup 10}B(n,{alpha}){sup 7}Li accounts for about 80 % of the total dose in a tumor with 40 ppm in {sup 10}B concentration. Present dosimetric methods are indirect, based on drug biodistribution statistical data and subjected to inter and intra-patient variability. In order to overcome the consequences of the concomitant high dosimetric uncertainties, we propose a SPECT (Single Photon Emission Tomography) approach based on the detection of the prompt gamma-ray (478 keV) emitted in 94 % of the cases from {sup 7}Li. For this purpose we designed, built and tested a prototype based on LaBr{sub 3}(Ce) scintillators. Measurements on a head and tumor phantom were performed in the accelerator-based BNCT facility of the University of Birmingham (UK). They result in the first tomographic image of the 10B capture distribution obtained in a BNCT facility.

  6. Effective dose to patients and staff when using a mobile PET/SPECT system.

    PubMed

    Studenski, Matthew T

    2013-01-01

    The purpose of this study was to determine the number of weekly acquisitions permissible using a mobile PET/SPECT scanner for myocardial perfusion/viability imaging in an intensive care unit (ICU) based on the effective dose to patients and staff. The effective dose to other patients and staff in an ICU was calculated following recommendations from the American Association of Physicists in Medicine Task Group 108 report (AAPM TG-108). The number of weekly acquisitions using 555 MBq (15 mCi) Tc-99m for myocardial perfusion or F-18 for myocardial viability was determined using the regulatory limits described in the Code of Federal Regulations 10 CFR 20. To increase the number of weekly acquisitions allowed, a reduction in administered dose and portable shielding was considered. A single myocardial perfusion image can be acquired with Tc-99m each week with a dose reduction to 455 MBq (12.3 mCi) without additional shielding. To acquire a myocardial viability image with F-18, an activity reduction to 220 MBq (5.9 mCi) is required to meet the regulatory effective dose limit without additional shielding. More than one weekly acquisition can be performed if additional shielding or activity reduction is utilized. A method for calculating dose to patients and staff in an ICU has been developed using conservative assumptions and following AAPM TG-108. This calculation must be repeated for each individual clinic before any acquisition is performed. PMID:23652256

  7. Characterization of a rotating slat collimator system dedicated to small animal imaging

    NASA Astrophysics Data System (ADS)

    Boisson, F.; Bekaert, V.; El Bitar, Z.; Wurtz, J.; Steibel, J.; Brasse, D.

    2011-03-01

    Some current investigations based on small animal models are dedicated to functional cerebral imaging. They represent a fundamental tool to understand the mechanisms involved in neurodegenerative diseases. In the radiopharmaceutical development approach, the main challenge is to measure the radioactivity distribution in the brain of a subject with good temporal and spatial resolutions. Classical SPECT systems mainly use parallel hole or pinhole collimators. In this paper we investigate the use of a rotating slat collimator system for small animal brain imaging. The proposed prototype consists of a 64-channel multi-anode photomultiplier tube (H8804, Hamamatsu Corp.) coupled to a YAP:Ce crystal highly segmented into 32 strips of 0.575 × 18.4 × 10 mm3. The parameters of the rotating slat collimator are optimized using GATE Monte Carlo simulations. The performance of the proposed prototype in terms of spatial resolution, detection efficiency and signal-to-noise ratio is compared to that obtained with a gamma camera equipped with a parallel hole collimator. Preliminary experimental results demonstrate that a spatial resolution of 1.54 mm can be achieved with a detection efficiency of 0.012% for a source located at 20 mm, corresponding to the position of the brain in the prototype field of view.

  8. Hybrid pixel-waveform CdTe/CZT detector for use in an ultrahigh resolution MRI compatible SPECT system

    PubMed Central

    Cai, Liang; Meng, Ling-Jian

    2013-01-01

    In this paper, we will present a new small pixel CdTe/CZT detector for sub-500 μm resolution SPECT imaging application inside MR scanner based on a recently developed hybrid pixel-waveform (HPWF) readout circuitry. The HPWF readout system consists of a 2-D multi-pixel circuitry attached to the anode pixels to provide the X–Y positions of interactions, and a high-speed digitizer to read out the pulse-waveform induced on the cathode. The digitized cathode waveform could provide energy deposition information, precise timing and depth-of-interaction information for gamma ray interactions. Several attractive features with this HPWF detector system will be discussed in this paper. To demonstrate the performance, we constructed several prototype HPWF detectors with pixelated CZT and CdTe detectors of 2–5 mm thicknesses, connected to a prototype readout system consisting of energy-resolved photon-counting ASIC for readout anode pixels and an Agilent high-speed digitizer for digitizing the cathode signals. The performances of these detectors based on HPWF are discussed in this paper. PMID:24371365

  9. Hybrid pixel-waveform CdTe/CZT detector for use in an ultrahigh resolution MRI compatible SPECT system.

    PubMed

    Cai, Liang; Meng, Ling-Jian

    2013-02-01

    In this paper, we will present a new small pixel CdTe/CZT detector for sub-500 μm resolution SPECT imaging application inside MR scanner based on a recently developed hybrid pixel-waveform (HPWF) readout circuitry. The HPWF readout system consists of a 2-D multi-pixel circuitry attached to the anode pixels to provide the X-Y positions of interactions, and a high-speed digitizer to read out the pulse-waveform induced on the cathode. The digitized cathode waveform could provide energy deposition information, precise timing and depth-of-interaction information for gamma ray interactions. Several attractive features with this HPWF detector system will be discussed in this paper. To demonstrate the performance, we constructed several prototype HPWF detectors with pixelated CZT and CdTe detectors of 2-5 mm thicknesses, connected to a prototype readout system consisting of energy-resolved photon-counting ASIC for readout anode pixels and an Agilent high-speed digitizer for digitizing the cathode signals. The performances of these detectors based on HPWF are discussed in this paper. PMID:24371365

  10. Hybrid pixel-waveform CdTe/CZT detector for use in an ultrahigh resolution MRI compatible SPECT system

    NASA Astrophysics Data System (ADS)

    Cai, Liang; Meng, Ling-Jian

    2013-02-01

    In this paper, we will present a new small pixel CdTe/CZT detector for sub-500 μm resolution SPECT imaging application inside MR scanner based on a recently developed hybrid pixel-waveform (HPWF) readout circuitry. The HPWF readout system consists of a 2-D multi-pixel circuitry attached to the anode pixels to provide the X-Y positions of interactions, and a high-speed digitizer to read out the pulse-waveform induced on the cathode. The digitized cathode waveform could provide energy deposition information, precise timing and depth-of-interaction information for gamma ray interactions. Several attractive features with this HPWF detector system will be discussed in this paper. To demonstrate the performance, we constructed several prototype HPWF detectors with pixelated CZT and CdTe detectors of 2-5 mm thicknesses, connected to a prototype readout system consisting of energy-resolved photon-counting ASIC for readout anode pixels and an Agilent high-speed digitizer for digitizing the cathode signals. The performances of these detectors based on HPWF are discussed in this paper.

  11. Lipid-Calcium Phosphate Nanoparticles for Delivery to the Lymphatic System and SPECT/CT Imaging of Lymph Node Metastases

    PubMed Central

    Tseng, Yu-Cheng; Xu, Zhenghong; Guley, Kevin; Yuan, Hong; Huang, Leaf

    2014-01-01

    A lipid/calcium/phosphate (LCP) nanoparticle (NP) formulation (particle diameter ~25 nm) with superior siRNA delivery efficiency was developed and reported previously. Here, we describe the successful formulation of 111In into LCP for SPECT/CT imaging. Imaging and biodistribution studies showed that, polyethylene glycol grafted 111In-LCP preferentially accumulated in the lymph nodes at ~70% ID/g in both C57BL/6 and nude mice when the improved surface coating method was used. Both the liver and spleen accumulated only ~25% ID/g. Larger LCP (diameter ~67 nm) was less lymphotropic. These results indicate that 25 nm LCP was able to penetrate into tissues, enter the lymphatic system, and accumulate in the lymph nodes via lymphatic drainage due to 1) small size, 2) a well-PEGylated lipid surface, and 3) a slightly negative surface charge. The capability of intravenously injected 111In-LCP to visualize an enlarged, tumor-loaded sentinel lymph node was demonstrated using a 4T1 breast cancer lymph node metastasis model. Systemic gene delivery to the lymph nodes after IV injection was demonstrated by the expression of red fluorescent protein cDNA. The potential of using LCP for lymphatic drug delivery is discussed. PMID:24613050

  12. UCD-SPI: Un-Collimated Detector Single-Photon Imaging System for Small Animal and Plant Imaging

    NASA Astrophysics Data System (ADS)

    Walker, Katherine Leigh

    Medical imaging systems using single gamma-ray emitting radioisotopes implement collimators in order to form images. However, a tradeoff in sensitivity is inherent in the use of collimators, and modern preclinical single-photon emission computed tomography (SPECT) systems detect a very small fraction of emitted gamma-rays (<0.3%). We have built a collimator-less system, which can reach sensitivity of 40% for 99mTc imaging, while still producing images of sufficient spatial resolution for certain applications in "thin" objects such as mice, small plants, and well plates used for in vitro experiments. This flexible geometry un-collimated detector single-photon imaging (UCD-SPI) system consists of two large (5 cm x 10 cm), thin (3 mm and 5 mm), closely spaced, pixelated scintillation detectors of either NaI(Tl), CsI(Na), or BGO. The detectors are read out by two adjacent Hamamatsu H8500 multichannel photomultiplier tubes. The detector heads enable the interchange of scintillation detectors of different materials and thicknesses to optimize performance for a wide range of gamma-ray energies and imaging subjects. The detectors are horizontally oriented for animal imaging, and for plant imaging the system is rotated on its side to orient the detectors vertically. While this un-collimated detector system is unable to approach the sub-mm spatial resolution obtained by the most advanced preclinical pinhole SPECT systems, the high sensitivity could enable significant and new use in molecular imaging applications which do not require good spatial resolution- for example, screening applications for drug development (small animals), for material transport and sequestration studies for phytoremediation (plants), or for counting radiolabeled cells in vitro (well plates).

  13. Brain SPECT quantitation in clinical diagnosis

    SciTech Connect

    Hellman, R.S.

    1991-12-31

    Methods to quantitate SPECT data for clinical diagnosis should be chosen so that they take advantage of the lessons learned from PET data. This is particularly important because current SPECT high-resolution brain imaging systems now produce images that are similar in resolution to those generated by the last generation PET equipment (9 mm FWHM). These high-resolution SPECT systems make quantitation of SPECT more problematic than earlier. Methodology validated on low-resolution SPECT systems may no longer be valid for data obtained with the newer SPECT systems. For example, in patients with dementia, the ratio of parietal to cerebellar activity often was studied. However, with new instruments, the cerebellum appears very different: discrete regions are more apparent. The large cerebellar regions usually used with older instrumentation are of an inappropriate size for the new equipment. The normal range for any method of quantitation determined using older equipment probably changes for data obtained with new equipment. It is not surprising that Kim et al. in their simulations demonstrated that because of the finite resolution of imaging systems, the ability to measure pure function is limited, with {open_quotes}anatomy{close_quotes} and {open_quotes}function{close_quotes} coupled in a {open_quotes}complex nonlinear way{close_quotes}. 11 refs.

  14. Sci—Thur PM: Imaging — 04: An iterative triple energy window (TEW) approach to cross talk correction in quantitative small animal Tc99m and In111 SPECT

    SciTech Connect

    Prior, P; Timmins, R; Wells, R G

    2014-08-15

    Dual isotope SPECT allows simultaneous measurement of two different tracers in vivo. With In111 (emission energies of 171keV and 245keV) and Tc99m (140keV), quantification of Tc99m is degraded by cross talk from the In111 photons that scatter and are detected at an energy corresponding to Tc99m. TEW uses counts recorded in two narrow windows surrounding the Tc99m primary window to estimate scatter. Iterative TEW corrects for the bias introduced into the TEW estimate resulting from un-scattered counts detected in the scatter windows. The contamination in the scatter windows is iteratively estimated and subtracted as a fraction of the scatter-corrected primary window counts. The iterative TEW approach was validated with a small-animal SPECT/CT camera using a 2.5mL plastic container holding thoroughly mixed Tc99m/In111 activity fractions of 0.15, 0.28, 0.52, 0.99, 2.47 and 6.90. Dose calibrator measurements were the gold standard. Uncorrected for scatter, the Tc99m activity was over-estimated by as much as 80%. Unmodified TEW underestimated the Tc99m activity by 13%. With iterative TEW corrections applied in projection space, the Tc99m activity was estimated within 5% of truth across all activity fractions above 0.15. This is an improvement over the non-iterative TEW, which could not sufficiently correct for scatter in the 0.15 and 0.28 phantoms.

  15. Development of a Numerical Method for Patient-Specific Cerebral Circulation Using 1D-0D Simulation of the Entire Cardiovascular System with SPECT Data.

    PubMed

    Zhang, Hao; Fujiwara, Naoya; Kobayashi, Masaharu; Yamada, Shigeki; Liang, Fuyou; Takagi, Shu; Oshima, Marie

    2016-08-01

    The detailed flow information in the circle of Willis (CoW) can facilitate a better understanding of disease progression, and provide useful references for disease treatment. We have been developing a one-dimensional-zero-dimensional (1D-0D) simulation method for the entire cardiovascular system to obtain hemodynamics information in the CoW. This paper presents a new method for applying 1D-0D simulation to an individual patient using patient-specific data. The key issue is how to adjust the deviation of physiological parameters, such as peripheral resistance, from literature data when patient-specific geometry is used. In order to overcome this problem, we utilized flow information from single photon emission computed tomography (SPECT) data. A numerical method was developed to optimize physiological parameters by adjusting peripheral cerebral resistance to minimize the difference between the resulting flow rate and the SPECT data in the efferent arteries of the CoW. The method was applied to three cases using different sets of patient-specific data in order to investigate the hemodynamics of the CoW. The resulting flow rates in the afferent arteries were compared to those of the phase-contrast magnetic resonance angiography (PC-MRA) data. Utilization of the SPECT data combined with the PC-MRA data showed a good agreement in flow rates in the afferent arteries of the CoW with those of PC-MRA data for all three cases. The results also demonstrated that application of SPECT data alone could provide the information on the ratios of flow distributions among arteries in the CoW. PMID:26721836

  16. Dual tracer imaging of SPECT and PET probes in living mice using a sequential protocol

    PubMed Central

    Chapman, Sarah E; Diener, Justin M; Sasser, Todd A; Correcher, Carlos; González, Antonio J; Avermaete, Tony Van; Leevy, W Matthew

    2012-01-01

    Over the past 20 years, multimodal imaging strategies have motivated the fusion of Positron Emission Tomography (PET) or Single Photon Emission Computed Tomography (SPECT) scans with an X-ray computed tomography (CT) image to provide anatomical information, as well as a framework with which molecular and functional images may be co-registered. Recently, pre-clinical nuclear imaging technology has evolved to capture multiple SPECT or multiple PET tracers to further enhance the information content gathered within an imaging experiment. However, the use of SPECT and PET probes together, in the same animal, has remained a challenge. Here we describe a straightforward method using an integrated trimodal imaging system and a sequential dosing/acquisition protocol to achieve dual tracer imaging with 99mTc and 18F isotopes, along with anatomical CT, on an individual specimen. Dosing and imaging is completed so that minimal animal manipulations are required, full trimodal fusion is conserved, and tracer crosstalk including down-scatter of the PET tracer in SPECT mode is avoided. This technique will enhance the ability of preclinical researchers to detect multiple disease targets and perform functional, molecular, and anatomical imaging on individual specimens to increase the information content gathered within longitudinal in vivo studies. PMID:23145357

  17. Animal Health and Welfare Issues Facing Organic Production Systems

    PubMed Central

    Sutherland, Mhairi A.; Webster, Jim; Sutherland, Ian

    2013-01-01

    Simple Summary The demand for organically grown, animal derived produce is increasing due to a growing desire for consumer products that have minimal chemical inputs and high animal welfare standards. Evaluation of the scientific literature suggests that a major challenge facing organic animal production systems is the management and treatment of health-related issues. However, implementation of effective management practices can help organic animal producers achieve and maintain high standards of health and welfare, which is necessary to assure consumers that organic animal-based food and fibre has not only been produced with minimal or no chemical input, but under high standards of animal welfare. Abstract The demand for organically-grown produce is increasing worldwide, with one of the drivers being an expectation among consumers that animals have been farmed to a high standard of animal welfare. This review evaluates whether this expectation is in fact being met, by describing the current level of science-based knowledge of animal health and welfare in organic systems. The primary welfare risk in organic production systems appears to be related to animal health. Organic farms use a combination of management practices, alternative and complementary remedies and convenional medicines to manage the health of their animals and in many cases these are at least as effective as management practices employed by non-organic producers. However, in contrast to non-organic systems, there is still a lack of scientifically evaluated, organically acceptable therapeutic treatments that organic animal producers can use when current management practices are not sufficient to maintain the health of their animals. The development of such treatments are necessary to assure consumers that organic animal-based food and fibre has not only been produced with minimal or no chemical input, but under high standards of animal welfare. PMID:26479750

  18. RESTRAINING SYSTEM FOR PLETHYSMOGRAPHY IN SMALL ANIMALS

    EPA Science Inventory

    A restraining technique for immobilizing awake guinea pigs and rats during physiological measurements is described. The basic device consists of an adjustable acrylic holder that supports the animal in a standing position while restricting movement of the four legs. The holder al...

  19. Transmission of systemic AA amyloidosis in animals.

    PubMed

    Murakami, T; Ishiguro, N; Higuchi, K

    2014-03-01

    Amyloidoses are a group of protein-misfolding disorders that are characterized by the deposition of amyloid fibrils in organs and/or tissues. In reactive amyloid A (AA) amyloidosis, serum AA (SAA) protein forms deposits in mice, domestic and wild animals, and humans that experience chronic inflammation. AA amyloid fibrils are abnormal β-sheet-rich forms of the serum precursor SAA, with conformational changes that promote fibril formation. Extracellular deposition of amyloid fibrils causes disease in affected animals. Recent findings suggest that AA amyloidosis could be transmissible. Similar to the pathogenesis of transmissible prion diseases, amyloid fibrils induce a seeding-nucleation process that may lead to development of AA amyloidosis. We review studies of possible transmission in bovine, avian, mouse, and cheetah AA amyloidosis. PMID:24280941

  20. Fluorescence-enhanced optical tomography and nuclear imaging system for small animals

    NASA Astrophysics Data System (ADS)

    Tan, I.-Chih; Lu, Yujie; Darne, Chinmay; Rasmussen, John C.; Zhu, Banghe; Azhdarinia, Ali; Yan, Shikui; Smith, Anne M.; Sevick-Muraca, Eva M.

    2012-03-01

    Near-infrared (NIR) fluorescence is an alternative modality for molecular imaging that has been demonstrated in animals and recently in humans. Fluorescence-enhanced optical tomography (FEOT) using continuous wave or frequency domain photon migration techniques could be used to provide quantitative molecular imaging in vivo if it could be validated against "gold-standard," nuclear imaging modalities, using dual-labeled imaging agents. Unfortunately, developed FEOT systems are not suitable for incorporation with CT/PET/SPECT scanners because they utilize benchtop devices and require a large footprint. In this work, we developed a miniaturized fluorescence imaging system installed in the gantry of the Siemens Inveon PET/CT scanner to enable NIR transillumination measurements. The system consists of a CCD camera equipped with NIR sensitive intensifier, a diode laser controlled by a single board compact controller, a 2-axis galvanometer, and RF circuit modules for homodyne detection of the phase and amplitude of fluorescence signals. The performance of the FEOT system was tested and characterized. A mouse-shaped solid phantom of uniform optical properties with a fluorescent inclusion was scanned using CT, and NIR fluorescence images at several projections were collected. The method of high-order approximation to the radioactive transfer equation was then used to reconstruct the optical images. Dual-labeled agents were also used on a tumor bearing mouse to validate the results of the FEOT against PET/CT image. The results showed that the location of the fluorophore obtained from the FEOT matches the location of tumor obtained from the PET/CT images. Besides validation of FEOT, this hybrid system could allow multimodal molecular imaging (FEOT/PET/CT) for small animal imaging.

  1. Effects of gravity perturbation on developing animal systems

    NASA Astrophysics Data System (ADS)

    Malacinski, G. M.; Neff, A. W.

    Developing systems provide unique opportunities for analyzing the effects of microgravity on animals. Several unusual types of cells as well as various extraordinary cellular behavior patterns characterize the embryos of most animals. Those features have been exploited as test systems for space flight. The data from previous experiments are reviewed, and considerations for the design of future experiments are presented.

  2. SPECT/NIRF Dual Modality Imaging for Detection of Intraperitoneal Colon Tumor with an Avidin/Biotin Pretargeting System

    PubMed Central

    Dong, Chengyan; Yang, Sujuan; Shi, Jiyun; Zhao, Huiyun; Zhong, Lijun; Liu, Zhaofei; Jia, Bing; Wang, Fan

    2016-01-01

    We describe herein dual-modality imaging of intraperitoneal colon tumor using an avidin/biotin pretargeting system. A novel dual-modality probe, 99mTc-HYNIC-lys(Cy5.5)-PEG4-biotin, was designed, synthesized and characterized. Single-photon emission computed tomography/ computed tomography (SPECT/CT) imaging and near infrared fluorescence (NIRF) imaging were developed using intraperitoneal LS180 human colon adenocarcinoma xenografts. Following avidin preinjection for 4 hours, 99mTc-HYNIC-lys(Cy5.5)-PEG4-biotin could successfully detect colon tumors of different sizes inside the abdominal region using both modalities, and the imaging results showed no differences. Biodistribution studies demonstrated that the tumors had a very high uptake of the probe 99mTc-HYNIC-lys(Cy5.5)-PEG4-biotin (12.74 ± 1.89% ID/g at 2 h p.i.), and the clearance from blood and other normal tissues occured very fast. The low tumor uptake in the non-pretargeted mice (1.63 ± 0.50% ID/g at 2 h p.i.) and tumor cell staining results showed excellent tumor binding specificity of the pretargeting system. The ability of the novel probe to show excellent imaging quality with high tumor-to-background contrast, a high degree of binding specificity with tumors and excellent in vivo biodistribution pharmacokinetics should prove that the avidin/biotin based dual-modality pretargeting probe is a promising imaging tool during the entire period of tumor diagnosis and treatment. PMID:26732543

  3. Animator

    ERIC Educational Resources Information Center

    Tech Directions, 2008

    2008-01-01

    Art and animation work is the most significant part of electronic game development, but is also found in television commercials, computer programs, the Internet, comic books, and in just about every visual media imaginable. It is the part of the project that makes an abstract design idea concrete and visible. Animators create the motion of life in…

  4. SPECT assay of radiolabeled monoclonal antibodies

    SciTech Connect

    Jaszczak, R.J.

    1992-02-01

    The accurate determination of the biodistribution of radiolabeled monoclonal antibodies (MoAbs) is important for calculation of dosimetry and evaluation of pharmacokinetic variables such as antibody dose and route of administration. The hypothesis of this application is that the biodistribution of radiolabeled monoclonal antibodies (MoAbs) can be quantitatively determined using single photon emission computed tomography (SPECT). The major thrusts during the third year include the continued development and evaluation of improved 3D SPECT acquisition and reconstruction approaches to improve quantitative imaging of radiolabeled monoclonal antibodies (MoAbs), and the implementation and evaluation of algorithms to register serial SPECT image data sets, or to register 3D SPECT images with 3D image data sets acquired from positron emission tomography (PEI) and magnetic resonance images (MRI). The research has involved the investigation of statistical models and iterative reconstruction algorithms that accurately account for the physical characteristics of the SPECT acquisition system. It is our belief that SPECT quantification can be improved by accurately modeling the physical processes such as attenuation, scatter, geometric collimator response, and other factors that affect the measured projection data.

  5. Animal-microbe interactions and the evolution of nervous systems.

    PubMed

    Eisthen, Heather L; Theis, Kevin R

    2016-01-01

    Animals ubiquitously interact with environmental and symbiotic microbes, and the effects of these interactions on animal physiology are currently the subject of intense interest. Nevertheless, the influence of microbes on nervous system evolution has been largely ignored. We illustrate here how taking microbes into account might enrich our ideas about the evolution of nervous systems. For example, microbes are involved in animals' communicative, defensive, predatory and dispersal behaviours, and have likely influenced the evolution of chemo- and photosensory systems. In addition, we speculate that the need to regulate interactions with microbes at the epithelial surface may have contributed to the evolutionary internalization of the nervous system. PMID:26598731

  6. A Monte Carlo simulation study of the feasibility of a high resolution parallel-hole collimator with a CdTe pixelated semiconductor SPECT system

    NASA Astrophysics Data System (ADS)

    Lee, Y.-J.; Park, S.-J.; Lee, S.-W.; Kim, D.-H.; Kim, Y.-S.; Jo, B.-D.; Kim, H.-J.

    2013-03-01

    It is recommended that a pixelated parallel-hole collimator in which the hole and pixel sizes are equal be used to improve the sensitivity and spatial resolution when using a small pixel size and a single-photon emission computed tomography (SPECT) system with pixelated semiconductor detector materials (e.g., CdTe and CZT). However, some significant problems arise in the manufacturing of a pixelated parallel-hole collimator. Therefore, we sought to simulate a pixelated semiconductor SPECT system with various collimator geometric designs. The purpose of this study was to compare the quality of images generated with a pixelated semiconductor SPECT system simulated with pixelated parallel-hole collimators of various geometric designs. The sensitivity and spatial resolution of the various collimator geometric designs with varying septal heights and hole sizes were measured. Moreover, to evaluate the overall performance of the imaging system, a hot-rod phantom was designed using a Monte Carlo simulation. According to the results, the average sensitivity using a 15 mm septal height was 1.80, 2.87, and 4.16 times higher than that obtained with septal heights of 20, 25, and 30 mm, respectively. Also, the average spatial resolution using the 30 mm septal height was 44.33, 22.08, and 9.26% better than that attained with 15, 20, and 25 mm septal heights, respectively. When the results acquired with 0.3 and 0.6 mm hole sizes were compared, the average sensitivity with the 0.6 mm hole size was 3.97 times higher than that obtained with the 0.3 mm hole size, and the average spatial resolution with the 0.3 mm hole size was 45.76% better than that with the 0.6 mm hole size. We have presented the pixelated parallel-hole collimators of various collimator geometric designs and evaluations. Our results showed that the effect of various collimator geometric designs can be investigated by Monte Carlo simulation so as to evaluate the feasibility of a high resolution parallel

  7. Effects of gravity perturbation on developing animal systems

    NASA Technical Reports Server (NTRS)

    Malacinski, G. M.; Neff, A. W.

    1986-01-01

    The use of developing animal systems to analyze the effects of microgravity on animals is discussed. Some of the key features of developing systems, especially embryos, are reviewed and relevant space data are summarized. Issues to be addressed in the design of future space experiments are discussed. It is noted that an embryo which exhibits ground based gravity effects should be selected for use as a model system and individual variation in gravity response among batches of embryos should be taken into account.

  8. Farm animal well-being and intensive production systems.

    PubMed

    Swanson, J C

    1995-09-01

    Animal welfare, or well-being, is a social issue with ethical, scientific, political, and aesthetic properties. Answering questions about the welfare of animals requires scientific definition, assessment, solutions, and public acceptance. With respect to the actual well-being of the animal, most issues are centered on how the animal "feels" when managed within a specific level of confinement, during special agricultural practices (e.g., tail docking, beak trimming, etc.) and handling. Questions of this nature may require exploration of animal cognition, motivation, perception, and emotional states in addition to more commonly recognized indicators of well-being. Several general approaches have emerged for solving problems concerning animal well-being in intensive production systems: environmental, genetic, and therapeutic. Environmental approaches involve modifying existing systems to accommodate specific welfare concerns or development of alternative systems. Genetic approaches involve changing the behavioral and (or) physiological nature of the animal to reduce or eliminate behaviors that are undesirable within intensive system. Therapeutic approaches of a physical (tail docking, beak trimming) and physiological (drug and nutritional therapy) nature bring both concern and promise with regard to the reduction of confinement stress. Finally, the recent focus on commodity quality assurance programs may indirectly provide benefits for animal well-being. Although research in the area of animal well-being will provide important information for better animal management, handling, care, and the physical design of intensive production systems there is still some uncertainty regarding public acceptance. The aesthetics of modern intensive production systems may have as much to do with public acceptance as with science. PMID:8582867

  9. Patient doses from hybrid SPECT-CT procedures.

    PubMed

    Avramova-Cholakova, S; Dimcheva, M; Petrova, E; Garcheva, M; Dimitrova, M; Palashev, Y; Vassileva, J

    2015-07-01

    The aim of this work is to estimate patient doses from hybrid single-photon emission computed tomography (SPECT) and computed tomography (CT) procedures. The study involved all four SPECT-CT systems in Bulgaria. Effective dose was estimated for about 100 patients per system. Ten types of examinations were considered, representing all diagnostic procedures performed in the SPECT-CT systems. Effective doses from the SPECT component were calculated applying the ICRP 53 and ICRP 80 conversion coefficients. Computed tomography dose index and dose length product were retrospectively obtained from the archives of the systems, and effective doses from the CT component were calculated with CT-Expo software. Parallel estimation of CT component contribution with the National Radiological Protection Board (NRPB) conversion coefficients was performed where applicable. Large variations were found in the current practice of SPECT-CT imaging. Optimisation actions and diagnostic reference levels were proposed. PMID:25862537

  10. An Ultrahigh Resolution SPECT System for I-125 Mouse Brain Imaging Studies

    PubMed Central

    Meng, L. J.; Fu, G.; Roy, E. J.; Suppe, B.; Chen, C. T.

    2009-01-01

    This paper presents some initial experimental results obtained with a dual-head prototype single photon emission microscope system (SPEM) that is dedicated to mouse brain studies using I-125 labeled radiotracers. In particular, this system will be used for in vivo tacking of radiolabeled T cells in mouse brain. This system is based on the use of the intensified electron multiplying charge-coupled device (I-EMCCD) camera that offers the combination of an excellent intrinsic spatial resolution, a good signal-to-noise ratio, a large active area and a reasonable detection efficiency over an energy range between 27–140keV. In this study, the dual-head SPEM system was evaluated using both resolution phantoms and a mouse with locally injected T cells labelled with I-125. It was demonstrated that for a relatively concentrated source object, the current dual-head SPEM system is capable of visualizing the tiny amount of radioactivity (~12 nCi) carried by a very small number (<1000) of T cells. The current SPEM system design allows four or six camera heads to be installed in a stationary system configuration that offers a doubled or tripled sensitivity at a spatial resolution similar to that obtained with the dualhead system. This development would provide a powerful tool for in vivo and non-invasive tracking of radiolabeled T cells in mouse brain and potentially for other rodent brain imaging studies. PMID:20161174

  11. AIRS: The Medical Imaging Software for Segmentation and Registration in SPECT/CT

    NASA Astrophysics Data System (ADS)

    Widita, R.; Kurniadi, R.; Haryanto, F.; Darma, Y.; Perkasa, Y. S.; Zasneda, S. S.

    2010-06-01

    We have been successfully developed a new software, Automated Image Registration and Segmentation (AIRS), to fuse the CT and SPECT images. It is designed to solve different registration and segmentation problems that arises in tomographic data sets. AIRS is addressed to obtain anatomic information to be applied to NanoSpect system which is imaging for nano-tissues or small animals. It will be demonstrated that the information obtained by SPECT/CT is more accurate in evaluating patients/objects than that obtained from either SPECT or CT alone. The registration methods developed here are for both two-dimensional and three-dimensional registration. We used normalized mutual information (NMI) which is amenable for images produced by different modalities and having unclear boundaries between tissues. The segmentation components used in this software is region growing algorithms which have proven to be an effective approach for image segmentation. The implementations of region growing developed here are connected threshold and neighborhood connected. Our method is designed to perform with clinically acceptable speed, using accelerated techniques (multiresolution).

  12. Organ volume estimation using SPECT

    SciTech Connect

    Zaidi, H.

    1996-06-01

    Knowledge of in vivo thyroid volume has both diagnostic and therapeutic importance and could lead to a more precise quantification of absolute activity contained in the thyroid gland. In order to improve single-photon emission computed tomography (SPECT) quantitation, attenuation correction was performed according to Chang`s algorithm. The dual window method was used for scatter subtraction. The author used a Monte Carlo simulation of the SPECT system to accurately determine the scatter multiplier factor k. Volume estimation using SPECT was performed by summing up the volume elements (voxels) lying within the contour of the object, determined by a fixed threshold and the gray level histogram (GLH) method. Thyroid phantom and patient studies were performed and the influence of (1) fixed thresholding, (2) automatic thresholding, (3) attenuation, (4) scatter, and (5) reconstruction filter were investigated. This study shows that accurate volume estimation of the thyroid gland is feasible when accurate corrections are performed. The relative error is within 7% for the GLH method combined with attenuation and scatter corrections.

  13. Animation of Dawn's Path Through the Solar System

    NASA Video Gallery

    This animation shows the path of NASA's Dawn spacecraft through the solar system, on its way to orbit the two most massive objects in the main asteroid belt. Dawn arrives at the protoplanet Vesta i...

  14. An image guided small animal stereotactic radiotherapy system.

    PubMed

    Sha, Hao; Udayakumar, Thirupandiyur S; Johnson, Perry B; Dogan, Nesrin; Pollack, Alan; Yang, Yidong

    2016-04-01

    Small animal radiotherapy studies should be performed preferably on irradiators capable of focal tumor irradiation and healthy tissue sparing. In this study, an image guided small animal arc radiation treatment system (iSMAART) was developed which can achieve highly precise radiation targeting through the utilization of onboard cone beam computed tomography (CBCT) guidance. The iSMAART employs a unique imaging and radiation geometry where animals are positioned upright. It consists of a stationary x-ray tube, a stationary flat panel detector, and a rotatable and translational animal stage. System performance was evaluated in regards to imaging, image guidance, animal positioning, and radiation targeting using phantoms and tumor bearing animals. The onboard CBCT achieved good signal, contrast, and sub-millimeter spatial resolution. The iodine contrast CBCT accurately delineated orthotopic prostate tumors. Animal positioning was evaluated with ~0.3 mm vertical displacement along superior-inferior direction. The overall targeting precision was within 0.4 mm. Stereotactic radiation beams conformal to tumor targets can be precisely delivered from multiple angles surrounding the animal. The iSMAART allows radiobiology labs to utilize an image guided precision radiation technique that can focally irradiate tumors while sparing healthy tissues at an affordable cost. PMID:26958942

  15. An image guided small animal stereotactic radiotherapy system

    PubMed Central

    Sha, Hao; Udayakumar, Thirupandiyur S.; Johnson, Perry B.; Dogan, Nesrin; Pollack, Alan; Yang, Yidong

    2016-01-01

    Small animal radiotherapy studies should be performed preferably on irradiators capable of focal tumor irradiation and healthy tissue sparing. In this study, an image guided small animal arc radiation treatment system (iSMAART) was developed which can achieve highly precise radiation targeting through the utilization of onboard cone beam computed tomography (CBCT) guidance. The iSMAART employs a unique imaging and radiation geometry where animals are positioned upright. It consists of a stationary x-ray tube, a stationary flat panel detector, and a rotatable and translational animal stage. System performance was evaluated in regards to imaging, image guidance, animal positioning, and radiation targeting using phantoms and tumor bearing animals. The onboard CBCT achieved good signal, contrast, and sub-millimeter spatial resolution. The iodine contrast CBCT accurately delineated orthotopic prostate tumors. Animal positioning was evaluated with ∼0.3 mm vertical displacement along superior-inferior direction. The overall targeting precision was within 0.4 mm. Stereotactic radiation beams conformal to tumor targets can be precisely delivered from multiple angles surrounding the animal. The iSMAART allows radiobiology labs to utilize an image guided precision radiation technique that can focally irradiate tumors while sparing healthy tissues at an affordable cost. PMID:26958942

  16. A passive integrated transponder system for tracking animal movements

    USGS Publications Warehouse

    Boarman, W.I.; Beigel, M.L.; Goodlett, G.C.; Sazaki, M.

    1999-01-01

    We describe an automated system that uses passive integrated transponder (PIT) tags to track movements of animals past specific locations. The system was designed to operate maintenance free for several months, be secure from vandalism and environmental damage, and record the identity, date, and time of passage of animals past a 2.4-m wide area. We used the system to monitor effectively the movements of 172 desert tortoises (Gopherus agassizii) through 2 storm drain culverts that pass beneath a state highway in the Mojave Desert, California. Four tortoises entered or passed through the culverts on 60 occasions. The system can be easily adapted to other species.

  17. Feasibility of small animal cranial irradiation with the microRT system

    PubMed Central

    Kiehl, Erich L.; Stojadinovic, Strahinja; Malinowski, Kathleen T.; Limbrick, David; Jost, Sarah C.; Garbow, Joel R.; Rubin, Joshua B.; Deasy, Joseph O.; Khullar, Divya; Izaguirre, Enrique W.; Parikh, Parag J.; Low, Daniel A.; Hope, Andrew J.

    2008-01-01

    Purpose: To develop and validate methods for small-animal CNS radiotherapy using the microRT system. Materials and Methods: A custom head immobilizer was designed and built to integrate with a pre-existing microRT animal couch. The Delrin® couch-immobilizer assembly, compatible with multiple imaging modalities (CT, microCT, microMR, microPET, microSPECT, optical), was first imaged via CT in order to verify the safety and reproducibility of the immobilization method. Once verified, the subject animals were CT-scanned while positioned within the couch-immobilizer assembly for treatment planning purposes. The resultant images were then imported into CERR, an in-house-developed research treatment planning system, and registered to the microRTP treatment planning space using rigid registration. The targeted brain was then contoured and conformal radiotherapy plans were constructed for two separate studies: (1) a whole-brain irradiation comprised of two lateral beams at the 90° and 270° microRT treatment positions and (2) a hemispheric (left-brain) irradiation comprised of a single A-P vertex beam at the 0° microRT treatment position. During treatment, subject animals (n=48) were positioned to the CERR-generated treatment coordinates using the three-axis microRT motor positioning system and were irradiated using a clinical Ir-192 high-dose-rate remote after-loading system. The radiation treatment course consisted of 5 Gy fractions, 3 days per week. 90% of the subjects received a total dose of 30 Gy and 10% received a dose of 60 Gy. Results: Image analysis verified the safety and reproducibility of the immobilizer. CT scans generated from repeated reloading and repositioning of the same subject animal in the couch-immobilizer assembly were fused to a baseline CT. The resultant analysis revealed a 0.09 mm average, center-of-mass translocation and negligible volumetric error in the contoured, murine brain. The experimental use of the head immobilizer added ±0.1 mm to

  18. Feasibility of small animal cranial irradiation with the microRT system

    SciTech Connect

    Kiehl, Erich L.; Stojadinovic, Strahinja; Malinowski, Kathleen T.; Limbrick, David; Jost, Sarah C.; Garbow, Joel R.; Rubin, Joshua B.; Deasy, Joseph O.; Khullar, Divya; Izaguirre, Enrique W.; Parikh, Parag J.; Low, Daniel A.; Hope, Andrew J.

    2008-10-15

    Purpose: To develop and validate methods for small-animal CNS radiotherapy using the microRT system. Materials and Methods: A custom head immobilizer was designed and built to integrate with a pre-existing microRT animal couch. The Delrin couch-immobilizer assembly, compatible with multiple imaging modalities (CT, microCT, microMR, microPET, microSPECT, optical), was first imaged via CT in order to verify the safety and reproducibility of the immobilization method. Once verified, the subject animals were CT-scanned while positioned within the couch-immobilizer assembly for treatment planning purposes. The resultant images were then imported into CERR, an in-house-developed research treatment planning system, and registered to the microRTP treatment planning space using rigid registration. The targeted brain was then contoured and conformal radiotherapy plans were constructed for two separate studies: (1) a whole-brain irradiation comprised of two lateral beams at the 90 degree sign and 270 degree sign microRT treatment positions and (2) a hemispheric (left-brain) irradiation comprised of a single A-P vertex beam at the 0 degree sign microRT treatment position. During treatment, subject animals (n=48) were positioned to the CERR-generated treatment coordinates using the three-axis microRT motor positioning system and were irradiated using a clinical Ir-192 high-dose-rate remote after-loading system. The radiation treatment course consisted of 5 Gy fractions, 3 days per week. 90% of the subjects received a total dose of 30 Gy and 10% received a dose of 60 Gy. Results: Image analysis verified the safety and reproducibility of the immobilizer. CT scans generated from repeated reloading and repositioning of the same subject animal in the couch-immobilizer assembly were fused to a baseline CT. The resultant analysis revealed a 0.09 mm average, center-of-mass translocation and negligible volumetric error in the contoured, murine brain. The experimental use of the head

  19. Myocardial infarct size quantification in mice by SPECT using a novel algorithm independent of a normal perfusion database

    PubMed Central

    2012-01-01

    Background There is a growing interest in developing non-invasive imaging techniques permitting infarct size (IS) measurements in mice. The aim of this study was to validate the high-resolution rodent Linoview single photon emission computed tomography (SPECT) system for non-invasive measurements of IS in mice by using a novel algorithm independent of a normal database, in comparison with histology. Methods Eleven mice underwent a left coronary artery ligature. Seven days later, animals were imaged on the SPECT 2h30 after injection of 173 ± 27 MBq of Tc-99m-sestamibi. Mice were subsequently killed, and their hearts were excised for IS determination with triphenyltetrazolium chloride (TTC) staining. SPECT images were reconstructed using the expectation maximization maximum likelihood algorithm, and the IS was calculated using a novel algorithm applied on the 20-segment polar map provided by the commercially available QPS software (Cedars-Sinai Medical Center, CA, USA). This original method is attractive by the fact that it does not require the implementation of a normal perfusion database. Results Reconstructed images allowed a clear delineation of the left ventricles borders in all mice. No significant difference was found between mean IS determined by SPECT and by TTC staining [37.9 ± 17.5% vs 35.6 ± 17.2%, respectively (P = 0.10)]. Linear regression analysis showed an excellent correlation between IS measured on the SPECT images and IS obtained with TTC staining (y = 0.95x + 0.03 (r = 0.97; P < 0.0001)), without bias, as demonstrated by the Bland-Altman plot. Conclusion Our results demonstrate the accuracy of the method for the measurement of myocardial IS in mice with the Linoview SPECT system. PMID:23272995

  20. [The Optimal Reconstruction Parameters by Scatter and Attenuation Corrections Using Multi-focus Collimator System in Thallium-201 Myocardial Perfusion SPECT Study].

    PubMed

    Shibutani, Takayuki; Onoguchi, Masahisa; Funayama, Risa; Nakajima, Kenichi; Matsuo, Shinro; Yoneyama, Hiroto; Konishi, Takahiro; Kinuya, Seigo

    2015-11-01

    The aim of this study was to reveal the optimal reconstruction parameters of ordered subset conjugates gradient minimizer (OSCGM) by no correction (NC), attenuation correction (AC), and AC+scatter correction (ACSC) using IQ-single photon emission computed tomography (SPECT) system in thallium-201 myocardial perfusion SPECT. Myocardial phantom acquired two patterns, with or without defect. Myocardial images were performed 5-point scale visual score and quantitative evaluations using contrast, uptake, and uniformity about the subset and update (subset×iteration) of OSCGM and the full width at half maximum (FWHM) of Gaussian filter by three corrections. We decided on optimal reconstruction parameters of OSCGM by three corrections. The number of subsets to create suitable images were 3 or 5 for NC and AC, 2 or 3 for ACSC. The updates to create suitable images were 30 or 40 for NC, 40 or 60 for AC, and 30 for ACSC. Furthermore, the FWHM of Gaussian filters were 9.6 mm or 12 mm for NC and ACSC, 7.2 mm or 9.6 mm for AC. In conclusion, the following optimal reconstruction parameters of OSCGM were decided; NC: subset 5, iteration 8 and FWHM 9.6 mm, AC: subset 5, iteration 8 and FWHM 7.2 mm, ACSC: subset 3, iteration 10 and FWHM 9.6 mm. PMID:26596202

  1. Design optimization of multi-pinhole micro-SPECT configurations by signal detection tasks and system performance evaluations for mouse cardiac imaging

    NASA Astrophysics Data System (ADS)

    Lee, M.-W.; Lin, W.-T.; Chen, Y.-C.

    2015-01-01

    An optimized configuration of multi-pinhole aperture can improve the spatial resolution and the sensitivity of pinhole SPECT simultaneously. In this study, an optimization strategy of the multi-pinhole configuration with a small detector is proposed for mouse cardiac imaging. A 14 mm-diameter spherical field-of-view (FOV) is used to accommodate the mouse heart. To accelerate the optimization process, the analytic models are applied to rapidly obtain the projection areas of the FOV, the sensitivities and the spatial resolutions of numerous system designs. The candidates of optimal multi-pinhole configuration are then decided by the preliminary evaluations with the analytic models. Subsequently, the pinhole SPECT systems equipped with the designed multi-pinhole apertures are modeled in GATE to generate the imaging system matrices (H matrices) for the system performance assessments. The area under the ROC curves (AUC) of the designed systems is evaluated by signal-known-exactly/background-known-statistically detection tasks with their corresponding H matrices. In addition, the spatial resolutions are estimated by the Fourier crosstalk approach, and the sensitivities are calculated with the H matrices of designed systems, respectively. Furthermore, a series of OSEM reconstruction images of synthetic phantoms, including the hot-rod phantom, mouse heart phantom and Defrise phantom, are reconstructed with the H matrices of designed systems. To quantify the sensitivity and resolution competition in the optimization process, the AUC from the detection tasks and the resolution estimated by the Fourier crosstalk are used as the figure of merits. A trade-off function of AUC and resolution is introduced to find the optimal multi-pinhole configuration. According to the examining results, a 22.5° rotated detector plus a 4-pinhole aperture with 22.5° rotation, 20% multiplexing and 1.52X magnification is the optimized multi-pinhole configuration for the micro pinhole-SPECT

  2. Design optimization of multi-pinhole micro-SPECT configurations by signal detection tasks and system performance evaluations for mouse cardiac imaging.

    PubMed

    Lee, M-W; Lin, W-T; Chen, Y-C

    2015-01-21

    An optimized configuration of multi-pinhole aperture can improve the spatial resolution and the sensitivity of pinhole SPECT simultaneously. In this study, an optimization strategy of the multi-pinhole configuration with a small detector is proposed for mouse cardiac imaging. A 14 mm-diameter spherical field-of-view (FOV) is used to accommodate the mouse heart. To accelerate the optimization process, the analytic models are applied to rapidly obtain the projection areas of the FOV, the sensitivities and the spatial resolutions of numerous system designs. The candidates of optimal multi-pinhole configuration are then decided by the preliminary evaluations with the analytic models. Subsequently, the pinhole SPECT systems equipped with the designed multi-pinhole apertures are modeled in GATE to generate the imaging system matrices (H matrices) for the system performance assessments. The area under the ROC curves (AUC) of the designed systems is evaluated by signal-known-exactly/background-known-statistically detection tasks with their corresponding H matrices. In addition, the spatial resolutions are estimated by the Fourier crosstalk approach, and the sensitivities are calculated with the H matrices of designed systems, respectively. Furthermore, a series of OSEM reconstruction images of synthetic phantoms, including the hot-rod phantom, mouse heart phantom and Defrise phantom, are reconstructed with the H matrices of designed systems. To quantify the sensitivity and resolution competition in the optimization process, the AUC from the detection tasks and the resolution estimated by the Fourier crosstalk are used as the figure of merits. A trade-off function of AUC and resolution is introduced to find the optimal multi-pinhole configuration. According to the examining results, a 22.5° rotated detector plus a 4-pinhole aperture with 22.5° rotation, 20% multiplexing and 1.52X magnification is the optimized multi-pinhole configuration for the micro pinhole-SPECT

  3. Fabrication of the pinhole aperture for AdaptiSPECT

    PubMed Central

    Kovalsky, Stephen; Kupinski, Matthew A.; Barrett, Harrison H.; Furenlid, Lars R.

    2015-01-01

    AdaptiSPECT is a pre-clinical pinhole SPECT imaging system under final construction at the Center for Gamma-Ray Imaging. The system is designed to be able to autonomously change its imaging configuration. The system comprises 16 detectors mounted on translational stages to move radially away and towards the center of the field-of-view. The system also possesses an adaptive pinhole aperture with multiple collimator diameters and pinhole sizes, as well as the possibility to switch between multiplexed and non-multiplexed imaging configurations. In this paper, we describe the fabrication of the AdaptiSPECT pinhole aperture and its controllers. PMID:26146443

  4. Comparison of Fusion Imaging Using a Combined SPECT/CT System and Intra-arterial CT: Assessment of Drug Distribution by an Implantable Port System in Patients Undergoing Hepatic Arterial Infusion Chemotherapy

    SciTech Connect

    Ikeda, Osamu Kusunoki, Shinichiroh; Nakaura, Takeshi; Shiraishi, Shinya; Kawanaka, Kouichi; Tomiguchi, Seiji; Yamashita, Yasuyuki; Takamori, Hiroshi; Chikamoto, Akira; Kanemitsu, Keiichiro

    2006-06-15

    Hepatic arterial infusion (HAI) chemotherapy is effective for treating primary and metastatic carcinoma of the liver. We compared the perfusion patterns of HAI chemotherapy on intra-arterial port-catheter computed tomography (iapc-CT) and fused images obtained with a combined single-photon emission computed tomography/computed tomography (SPECT/CT) system. We studied 28 patients with primary or metastatic carcinoma of the liver who bore an implantable HAI port system. All underwent abdominal SPECT using Tc-99m-MAA (185 Mbq); the injection rate was 1 mL/min, identical to the chemotherapy infusion rate, and 0.5 mL/sec for iapc-CT. Delivery was through an implantable port. We compared the intrahepatic perfusion (IHP) and extrahepatic perfusion (EHP) patterns of HAI chemotherapy on iapc-CT images and fused images obtained with a combined SPECT/CT system. In 23 of 28 patients (82%), IHP patterns on iapc-CT images and fused images were identical. In 5 of the 28 patients (18%), IHP on fusion images was different from IHP on iapc-CT images. EHP was seen on fused images in 12 of the 28 patients (43%) and on iapc-CT images in 8 patients (29%). In 17 patients (61%), upper gastrointestinal endoscopy revealed gastroduodenal mucosal lesions. EHP was revealed on fused images in 10 of these patients; 9 of them manifested gastroduodenal toxicity at the time of subsequent HAI chemotherapy. Fusion imaging using the combined SPECT/CT system reflects the actual distribution of the infused anticancer agent. This information is valuable not only for monitoring adequate drug distribution but also for avoiding potential extrahepatic complications.

  5. Adaptive SPECT imaging with crossed-slit apertures

    PubMed Central

    Durko, Heather L.; Furenlid, Lars R.

    2015-01-01

    Preclinical single-photon emission computed tomography (SPECT) is an essential tool for studying the progression, response to treatment, and physiological changes in small animal models of human disease. The wide range of imaging applications is often limited by the static design of many preclinical SPECT systems. We have developed a prototype imaging system that replaces the standard static pinhole aperture with two sets of movable, keel-edged copper-tungsten blades configured as crossed (skewed) slits. These apertures can be positioned independently between the object and detector, producing a continuum of imaging configurations in which the axial and transaxial magnifications are not constrained to be equal. We incorporated a megapixel silicon double-sided strip detector to permit ultrahigh-resolution imaging. We describe the configuration of the adjustable slit aperture imaging system and discuss its application toward adaptive imaging, and reconstruction techniques using an accurate imaging forward model, a novel geometric calibration technique, and a GPU-based ultra-high-resolution reconstruction code. PMID:26190884

  6. Un-collimated single-photon imaging system for high-sensitivity small animal and plant imaging

    NASA Astrophysics Data System (ADS)

    Walker, Katherine L.; Judenhofer, Martin S.; Cherry, Simon R.; Mitchell, Gregory S.

    2015-01-01

    In preclinical single-photon emission computed tomography (SPECT) system development the primary objective has been to improve spatial resolution by using novel parallel-hole or multi-pinhole collimator geometries. However, such high-resolution systems have relatively poor sensitivity (typically 0.01-0.1%). In contrast, a system that does not use collimators can achieve very high-sensitivity. Here we present a high-sensitivity un-collimated detector single-photon imaging (UCD-SPI) system for the imaging of both small animals and plants. This scanner consists of two thin, closely spaced, pixelated scintillator detectors that use NaI(Tl), CsI(Na), or BGO. The performance of the system has been characterized by measuring sensitivity, spatial resolution, linearity, detection limits, and uniformity. With 99mTc (140 keV) at the center of the field of view (20 mm scintillator separation), the sensitivity was measured to be 31.8% using the NaI(Tl) detectors and 40.2% with CsI(Na). The best spatial resolution (FWHM when the image formed as the geometric mean of the two detector heads, 20 mm scintillator separation) was 19.0 mm for NaI(Tl) and 11.9 mm for CsI(Na) at 140 keV, and 19.5 mm for BGO at 1116 keV, which is somewhat degraded compared to the cm-scale resolution obtained with only one detector head and a close source. The quantitative accuracy of the system’s linearity is better than 2% with detection down to activity levels of 100 nCi. Two in vivo animal studies (a renal scan using 99mTc MAG-3 and a thyroid scan with 123I) and one plant study (a 99mTcO4- xylem transport study) highlight the unique capabilities of this UCD-SPI system. From the renal scan, we observe approximately a one thousand-fold increase in sensitivity compared to the Siemens Inveon SPECT/CT scanner. UCD-SPI is useful for many imaging tasks that do not require excellent spatial resolution, such as high-throughput screening applications, simple radiotracer uptake studies in tumor

  7. Diagnosis of myocardial involvement in patients with systemic myopathies with 15-(p-(I-123)iodophenyl) pentadecanoic acid (IPPA) SPECT

    SciTech Connect

    Kropp, J.; Briele, B.; Smekal, A.V.; Hotze, A.L.; Biersack, H.J.; Koehler, U.; Zierz, St. ); Knapp, F.F. )

    1992-01-01

    Involvement of the myocardium in non-infectious myopathies presents in most cases as systolic dysfunction or a disturbed cardiac rhythm. We are interested in exploring how often cardiac involvement can be evaluated with various diagnostic techniques in patients with proven myopathy. We investigated 41 patients with myopathies of various etiology, including mitochondrial and congenital myopathies, Curshmann-Steinert disease, muscular dystrophy, and others. Myopathy was proven by muscular biopsy usually from the bicep. Fatty acid imaging was performed with 15-(p-(I-123)iodophenyl)pentadecanoic acid (IP-PA) and sequential SPECT-scintigraphy with a 180 deg. rotation starting at the 45 deg. RAO position. 190 MBq were injected at the maximal stage of a submaximal exercise. Filtered backprojection and reorientation of the slices were achieved by standard techniques. The quantitative comparison of the oblique slices (bulls-eye technique) of the SPECT-studies revealed turnover-rates as a qualitative measure of {beta}-oxidation. Serum levels of lactate (L), pyruvate (P), glucose (G) and triglycerides (TG) were measured at rest and stress. Ventricular function was investigated by radionuclide ventriculography (MUGA) at rest and under stress with Tc-99m labeled red blood cells. In addition, ECG, 24 hour-ECG, and echocardiography were also performed with standard techniques.

  8. Diagnosis of myocardial involvement in patients with systemic myopathies with 15-(p-[I-123]iodophenyl) pentadecanoic acid (IPPA) SPECT

    SciTech Connect

    Kropp, J.; Briele, B.; Smekal, A.V.; Hotze, A.L.; Biersack, H.J.; Koehler, U.; Zierz, St.; Knapp, F.F.

    1992-03-01

    Involvement of the myocardium in non-infectious myopathies presents in most cases as systolic dysfunction or a disturbed cardiac rhythm. We are interested in exploring how often cardiac involvement can be evaluated with various diagnostic techniques in patients with proven myopathy. We investigated 41 patients with myopathies of various etiology, including mitochondrial and congenital myopathies, Curshmann-Steinert disease, muscular dystrophy, and others. Myopathy was proven by muscular biopsy usually from the bicep. Fatty acid imaging was performed with 15-(p-[I-123]iodophenyl)pentadecanoic acid (IP-PA) and sequential SPECT-scintigraphy with a 180 deg. rotation starting at the 45 deg. RAO position. 190 MBq were injected at the maximal stage of a submaximal exercise. Filtered backprojection and reorientation of the slices were achieved by standard techniques. The quantitative comparison of the oblique slices (bulls-eye technique) of the SPECT-studies revealed turnover-rates as a qualitative measure of {beta}-oxidation. Serum levels of lactate (L), pyruvate (P), glucose (G) and triglycerides (TG) were measured at rest and stress. Ventricular function was investigated by radionuclide ventriculography (MUGA) at rest and under stress with Tc-99m labeled red blood cells. In addition, ECG, 24 hour-ECG, and echocardiography were also performed with standard techniques.

  9. Performance evaluation of high-resolution square parallel-hole collimators with a CZT room temperature pixelated semiconductor SPECT system: a Monte Carlo simulation study

    NASA Astrophysics Data System (ADS)

    Lee, Y.; Kang, W.

    2015-07-01

    The pixelated semiconductor based on cadmium zinc telluride (CZT) is a promising imaging device that provides many benefits compared with conventional scintillation detectors. By using a high-resolution square parallel-hole collimator with a pixelated semiconductor detector, we were able to improve both sensitivity and spatial resolution. Here, we present a simulation of a CZT pixleated semiconductor single-photon emission computed tomography (SPECT) system with a high-resolution square parallel-hole collimator using various geometric designs of 0.5, 1.0, 1.5, and 2.0 mm X-axis hole size. We performed a simulation study of the eValuator-2500 (eV Microelectronics Inc., Saxonburg, PA, U.S.A.) CZT pixelated semiconductor detector using a Geant4 Application for Tomographic Emission (GATE). To evaluate the performances of these systems, the sensitivity and spatial resolution was evaluated. Moreover, to evaluate the overall performance of the imaging system, a hot-rod phantom was designed. Our results showed that the average sensitivity of the 2.0 mm collimator X-axis hole size was 1.34, 1.95, and 3.92 times higher than that of the 1.5, 1.0, and 0.5 mm collimator X-axis hole size, respectively. Also, the average spatial resolution of the 0.5 mm collimator X-axis hole size was 28.69, 44.65, and 55.73% better than that of the 1.0, 1.5, and 2.0 mm collimator X-axis hole size, respectively. We discuss the high-resolution square parallel-hole collimator of various collimator geometric designs and our evaluations. In conclusion, we have successfully designed a high-resolution square parallel-hole collimator with a CZT pixelated semiconductor SPECT system.

  10. Static and Animated Presentations in Learning Dynamic Mechanical Systems

    ERIC Educational Resources Information Center

    Boucheix, Jean-Michel; Schneider, Emmanuel

    2009-01-01

    In two experiments, we investigated how learners comprehend the functioning of a three-pulley system from a presentation on a computer screen. In the first experiment (N = 62) we tested the effect of static vs. animated presentations on comprehension. In the second experiment (N = 45), we tested the effect of user-control of an animated…

  11. Training Sessions Provide Working Knowledge of National Animal Identification System

    ERIC Educational Resources Information Center

    Glaze, J. Benton, Jr.; Ahola, Jason K.

    2010-01-01

    One in-service and two train-the-trainer workshops were conducted by University of Idaho Extension faculty, Idaho State Department of Agriculture personnel, and allied industry representatives to increase Extension educators' knowledge and awareness of the National Animal Identification System (NAIS) and related topics. Training sessions included…

  12. An Automated Motion Detection and Reward System for Animal Training

    PubMed Central

    Miller, Brad; Lim, Audrey N; Heidbreder, Arnold F

    2015-01-01

    A variety of approaches has been used to minimize head movement during functional brain imaging studies in awake laboratory animals. Many laboratories expend substantial effort and time training animals to remain essentially motionless during such studies. We could not locate an “off-the-shelf” automated training system that suited our needs.  We developed a time- and labor-saving automated system to train animals to hold still for extended periods of time. The system uses a personal computer and modest external hardware to provide stimulus cues, monitor movement using commercial video surveillance components, and dispense rewards. A custom computer program automatically increases the motionless duration required for rewards based on performance during the training session but allows changes during sessions. This system was used to train cynomolgus monkeys (Macaca fascicularis) for awake neuroimaging studies using positron emission tomography (PET) and functional magnetic resonance imaging (fMRI). The automated system saved the trainer substantial time, presented stimuli and rewards in a highly consistent manner, and automatically documented training sessions. We have limited data to prove the training system's success, drawn from the automated records during training sessions, but we believe others may find it useful. The system can be adapted to a range of behavioral training/recording activities for research or commercial applications, and the software is freely available for non-commercial use. PMID:26798573

  13. An Automated Motion Detection and Reward System for Animal Training.

    PubMed

    Miller, Brad; Lim, Audrey N; Heidbreder, Arnold F; Black, Kevin J

    2015-01-01

    A variety of approaches has been used to minimize head movement during functional brain imaging studies in awake laboratory animals. Many laboratories expend substantial effort and time training animals to remain essentially motionless during such studies. We could not locate an "off-the-shelf" automated training system that suited our needs.  We developed a time- and labor-saving automated system to train animals to hold still for extended periods of time. The system uses a personal computer and modest external hardware to provide stimulus cues, monitor movement using commercial video surveillance components, and dispense rewards. A custom computer program automatically increases the motionless duration required for rewards based on performance during the training session but allows changes during sessions. This system was used to train cynomolgus monkeys (Macaca fascicularis) for awake neuroimaging studies using positron emission tomography (PET) and functional magnetic resonance imaging (fMRI). The automated system saved the trainer substantial time, presented stimuli and rewards in a highly consistent manner, and automatically documented training sessions. We have limited data to prove the training system's success, drawn from the automated records during training sessions, but we believe others may find it useful. The system can be adapted to a range of behavioral training/recording activities for research or commercial applications, and the software is freely available for non-commercial use. PMID:26798573

  14. Ready for prime time? Dual tracer PET and SPECT imaging

    PubMed Central

    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 99mTc and 18F concentrations and illustrate the utility of such approaches in two sequential SPECT-PET/CT studies that include 99mTc-MAA/18F-NaF and 99mTc-Pentetate/18F-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 molecular

  15. Food for thought: food systems, livestock futures and animal health.

    PubMed

    Wilkinson, Angela

    2013-12-01

    Global food security, livestock production and animal health are inextricably bound. However, our focus on the future tends to disaggregate food and health into largely separate domains. Indeed, much foresight work is either food systems or health-based with little overlap in terms of predictions or narratives. Work on animal health is no exception. Part of the problem is the fundamental misunderstanding of the role, nature and impact of the modern futures tool kit. Here, I outline three key issues in futures research ranging from methodological confusion over the application of scenarios to the failure to effectively integrate multiple methodologies to the gap between the need for more evidence and power and control over futures processes. At its core, however, a better understanding of the narrative and worldview framing much of the futures work in animal health is required to enhance the value and impact of such exercises. PMID:23988197

  16. Freehand SPECT in low uptake situations

    NASA Astrophysics Data System (ADS)

    Lasser, Tobias; Ziegler, Sibylle I.; Navab, Nassir

    2011-03-01

    3D functional imaging in the operating room can be extremely useful for some procedures like SLN mapping or SLN biopsies. Freehand SPECT is an example of such an imaging modality, combining manually scanned, hand-held 1D gamma detectors with spatial positioning systems in order to reconstruct localized 3D SPECT images, for example in the breast or neck region. Standard series expansion methods are applied together with custom physical models of the acquisition process and custom filtering procedures to perform 3D tomographic reconstruction from sparse, limited-angle and irregularly sampled data. A Freehand SPECT system can easily be assembled on a mobile cart suitable for use in the operating room. This work addresses in particular the problem of objects with low uptake (like sentinel lymph nodes), where reconstruction tends to be difficult due to low signal to noise ratio. In a neck-like phantom study, we show that four simulated nodes of 250 microliter volume with 0.06% respectively 0.03% uptake of a virtual 70MBq injection of Tc99m (the typical activity for SLN procedures at our hospital) in a background of water can be reconstructed successfully using careful filtering procedures in the reconstruction pipeline. Ten independent Freehand SPECT scans of the phantom were performed by several different operators, with an average scan duration of 5.1 minutes. The resulting reconstructions show an average spatial accuracy within voxel dimensions (2.5mm) compared to CT and exhibit correct relative quantification.

  17. Proceedings of clinical SPECT (single photon emission computed tomography) symposium

    SciTech Connect

    Not Available

    1986-09-01

    It has been five years since the last in-depth American College of Nuclear Physicians/Society of Nuclear Medicine Symposium on the subject of single photon emission computed tomography (SPECT) was held. Because this subject was nominated as the single most desired topic we have selected SPECT imaging as the basis for this year's program. The objectives of this symposium are to survey the progress of SPECT clinical applications that have taken place over the last five years and to provide practical and timely guidelines to users of SPECT so that this exciting imaging modality can be fully integrated into the evaluation of pathologic processes. The first half was devoted to a consideration of technical factors important in SPECT acquisition and the second half was devoted to those organ systems about which sufficient clinical SPECT imaging data are available. With respect to the technical aspect of the program we have selected the key areas which demand awareness and attention in order to make SPECT operational in clinical practice. These include selection of equipment, details of uniformity correction, utilization of phantoms for equipment acceptance and quality assurance, the major aspect of algorithms, an understanding of filtered back projection and appropriate choice of filters and an awareness of the most commonly generated artifacts and how to recognize them. With respect to the acquisition and interpretation of organ images, the faculty will present information on the major aspects of hepatic, brain, cardiac, skeletal, and immunologic imaging techniques. Individual papers are processed separately for the data base. (TEM)

  18. Monte Carlo scatter correction for SPECT

    NASA Astrophysics Data System (ADS)

    Liu, Zemei

    The goal of this dissertation is to present a quantitatively accurate and computationally fast scatter correction method that is robust and easily accessible for routine applications in SPECT imaging. A Monte Carlo based scatter estimation method is investigated and developed further. The Monte Carlo simulation program SIMIND (Simulating Medical Imaging Nuclear Detectors), was specifically developed to simulate clinical SPECT systems. The SIMIND scatter estimation (SSE) method was developed further using a multithreading technique to distribute the scatter estimation task across multiple threads running concurrently on multi-core CPU's to accelerate the scatter estimation process. An analytical collimator that ensures less noise was used during SSE. The research includes the addition to SIMIND of charge transport modeling in cadmium zinc telluride (CZT) detectors. Phenomena associated with radiation-induced charge transport including charge trapping, charge diffusion, charge sharing between neighboring detector pixels, as well as uncertainties in the detection process are addressed. Experimental measurements and simulation studies were designed for scintillation crystal based SPECT and CZT based SPECT systems to verify and evaluate the expanded SSE method. Jaszczak Deluxe and Anthropomorphic Torso Phantoms (Data Spectrum Corporation, Hillsborough, NC, USA) were used for experimental measurements and digital versions of the same phantoms employed during simulations to mimic experimental acquisitions. This study design enabled easy comparison of experimental and simulated data. The results have consistently shown that the SSE method performed similarly or better than the triple energy window (TEW) and effective scatter source estimation (ESSE) methods for experiments on all the clinical SPECT systems. The SSE method is proven to be a viable method for scatter estimation for routine clinical use.

  19. NASA Workshop on Animal Gravity-Sensing Systems

    NASA Technical Reports Server (NTRS)

    Corcoran, M. L. (Editor)

    1986-01-01

    The opportunity for space flight has brought about the need for well-planned research programs that recognize the significance of space flight as a scientific research tool for advancing knowledge of life on Earth, and that utilize each flight opportunity to its fullest. For the first time in history, gravity can be almost completely eliminated. Thus, studies can be undertaken that will help to elucidate the importance of gravity to the normal functioning of living organisms, and to determine the effects microgravity may have on an organism. This workshop was convened to organize a plan for space research on animal gravity-sensing systems and the role that gravity plays in the development and normal functioning of these systems. Scientists working in the field of animal gravity-sensing systems use a wide variety of organisms in their research. The workshop presentations dealt with topics which ranged from the indirect gravity receptor of the water flea, Daphnia (whose antennal setae apparently act as current-sensing receptors as the animal moves up and down in water), through specialized statocyst structures found in jellyfish and gastropods, to the more complex vestibular systems that are characteristic of amphibians, avians, and mammals.

  20. Applications of penetrating radiation for small animal imaging

    NASA Astrophysics Data System (ADS)

    Hasegawa, Bruce H.; Wu, Max C.; Iwata, Koji; Hwang, Andrew B.; Wong, Kenneth H.; Barber, William C.; Dae, Michael W.; Sakdinawat, Anne E.

    2002-11-01

    than those used with microPET. High-resolution dual-modality imaging systems now are being developed that combine microPET or microSPECT with microCT in a way that facilitates more direct correlation of anatomy and physiology in the same animal. Small animal imaging allows researchers to perform experiments that are not possible with conventional invasive techniques, and thereby are becoming increasingly important tools for discovery of fundamental biological information, and development of new diagnostic and therapeutic techniques in the biomedical sciences.

  1. Bioluminescent system for dynamic imaging of cell and animal behavior

    SciTech Connect

    Hara-Miyauchi, Chikako; Tsuji, Osahiko; Hanyu, Aki; Okada, Seiji; Yasuda, Akimasa; Fukano, Takashi; Akazawa, Chihiro; Nakamura, Masaya; Imamura, Takeshi; Matsuzaki, Yumi; Okano, Hirotaka James; and others

    2012-03-09

    Highlights: Black-Right-Pointing-Pointer We combined a yellow variant of GFP and firefly luciferase to make ffLuc-cp156. Black-Right-Pointing-Pointer ffLuc-cp156 showed improved photon yield in cultured cells and transgenic mice. Black-Right-Pointing-Pointer ffLuc-cp156 enabled video-rate bioluminescence imaging of freely-moving animals. Black-Right-Pointing-Pointer ffLuc-cp156 mice enabled tracking real-time drug delivery in conscious animals. -- Abstract: The current utility of bioluminescence imaging is constrained by a low photon yield that limits temporal sensitivity. Here, we describe an imaging method that uses a chemiluminescent/fluorescent protein, ffLuc-cp156, which consists of a yellow variant of Aequorea GFP and firefly luciferase. We report an improvement in photon yield by over three orders of magnitude over current bioluminescent systems. We imaged cellular movement at high resolution including neuronal growth cones and microglial cell protrusions. Transgenic ffLuc-cp156 mice enabled video-rate bioluminescence imaging of freely moving animals, which may provide a reliable assay for drug distribution in behaving animals for pre-clinical studies.

  2. Early animal evolution and the origins of nervous systems

    PubMed Central

    Budd, Graham E.

    2015-01-01

    Understanding the evolution of early nervous systems is hazardous because we lack good criteria for determining homology between the systems of distant taxa; the timing of the evolutionary events is contested, and thus the relevant ecological and geological settings for them are also unclear. Here I argue that no simple approach will resolve the first issue, but that it remains likely that animals evolved relatively late, and that their nervous systems thus arose during the late Ediacaran, in a context provided by the changing planktonic and benthic environments of the time. The early trace fossil provides the most concrete evidence for early behavioural diversification, but it cannot simply be translated into increasing nervous system complexity: behavioural complexity does not map on a one-to-one basis onto nervous system complexity, both because of possible limitations to behaviour caused by the environment and because we know that even organisms without nervous systems are capable of relatively complex behaviour. PMID:26554037

  3. Early animal evolution and the origins of nervous systems.

    PubMed

    Budd, Graham E

    2015-12-19

    Understanding the evolution of early nervous systems is hazardous because we lack good criteria for determining homology between the systems of distant taxa; the timing of the evolutionary events is contested, and thus the relevant ecological and geological settings for them are also unclear. Here I argue that no simple approach will resolve the first issue, but that it remains likely that animals evolved relatively late, and that their nervous systems thus arose during the late Ediacaran, in a context provided by the changing planktonic and benthic environments of the time. The early trace fossil provides the most concrete evidence for early behavioural diversification, but it cannot simply be translated into increasing nervous system complexity: behavioural complexity does not map on a one-to-one basis onto nervous system complexity, both because of possible limitations to behaviour caused by the environment and because we know that even organisms without nervous systems are capable of relatively complex behaviour. PMID:26554037

  4. The importance of animal cognition in agricultural animal production systems: an overview.

    PubMed

    Curtis, S E; Stricklin, W R

    1991-12-01

    To describe and then fulfill agricultural animals' needs, we must learn more about their fundamental psychological and behavioral processes. How does this animal feel? Is that animal suffering? Will we ever be able to know these things? Scientists specializing in animal cognition say that there are numerous problems but that they can be overcome. Recognition by scientists of the notion of animal awareness has been increasing in recent years, because of the work of Griffin and others. Feeling, thinking, remembering, and imagining are cognitive processes that are factors in the economic and humane production of agricultural animals. It has been observed that the animal welfare debate depends on two controversial questions: Do animals have subjective feelings? If they do, can we find indicators that reveal them? Here, indirect behavioral analysis approaches must be taken. Moreover, the linear additivity of several stressor effects on a variety of animal traits suggests that some single phenomenon is acting as a "clearinghouse" for many or all of the stresses acting on an animal at any given time, and this phenomenon might be psychological stress. Specific situations animals may encounter in agricultural production settings are discussed with respect to the animals' subjective feelings. PMID:1808193

  5. High-resolution single photon planar and spect imaging of brain and neck employing a system of two co-registered opposed gamma imaging heads

    DOEpatents

    Majewski, Stanislaw; Proffitt, James

    2011-12-06

    A compact, mobile, dedicated SPECT brain imager that can be easily moved to the patient to provide in-situ imaging, especially when the patient cannot be moved to the Nuclear Medicine imaging center. As a result of the widespread availability of single photon labeled biomarkers, the SPECT brain imager can be used in many locations, including remote locations away from medical centers. The SPECT imager improves the detection of gamma emission from the patient's head and neck area with a large field of view. Two identical lightweight gamma imaging detector heads are mounted to a rotating gantry and precisely mechanically co-registered to each other at 180 degrees. A unique imaging algorithm combines the co-registered images from the detector heads and provides several SPECT tomographic reconstructions of the imaged object thereby improving the diagnostic quality especially in the case of imaging requiring higher spatial resolution and sensitivity at the same time.

  6. Reducing Multiplexing Artifacts in Multi-Pinhole SPECT with a Stacked Silicon-Germanium System: a Simulation Study

    PubMed Central

    Johnson, Lindsay C.; Shokouhi, Sepideh; Peterson, Todd E

    2015-01-01

    In pinhole SPECT, multi-pinhole collimators can increase sensitivity but may lead to projection overlap, or multiplexing, which can cause image artifacts. In this work we explore whether a stacked-detector configuration with a germanium and a silicon detector, used with 123I (27–32, 159 keV), where little multiplexing occurs in the Si projections, can reduce image artifacts caused by highly-multiplexed Ge projections. Simulations are first used to determine a reconstruction method that combines the Si and Ge projections to maximize image quality. Next, simulations of different pinhole configurations (varying projection multiplexing) in conjunction with digital phantoms are used to examine whether additional Si projections mitigate artifacts from the multiplexing in the Ge projections. Reconstructed images using both Si and Ge data are compared to those using Ge data alone. Normalized mean-square error and normalized standard deviation provide a quantitative evaluation of reconstructed images’ error and noise, respectively, and are used to evaluate the impact of the additional non-multiplexed data on image quality. For a qualitative comparison, the differential point response function is used to examine multiplexing artifacts. Results show that in cases of highly-multiplexed Ge projections, the addition of low-multiplexed Si projections helps to reduce image artifacts both quantitatively and qualitatively. PMID:25055382

  7. Definition of animal breeding goals for sustainable production systems.

    PubMed

    Olesen, I; Groen, A F; Gjerde, B

    2000-03-01

    What we do is determined by the way we "view" a complex issue and what sample of issues or events we choose to deal with. In this paper, a model based on a communal, cultural, or people-centered worldview, informed by a subjective epistemology and a holistic ontology, is considered. Definitions and interpretations of sustainable agriculture are reviewed. Common elements in published definitions of sustainable agriculture and animal production among those who seek long-term and equitable solutions for food production are resource efficiency, profitability, productivity, environmental soundness, biodiversity, social viability, and ethical aspects. Possible characteristics of future sustainable production systems and further development are presented. The impact of these characteristics on animal breeding goals is reviewed. The need for long-term biologically, ecologically, and sociologically sound breeding goals is emphasized, because animal breeding determined only by short-term market forces leads to unwanted side effects. Hence, a procedure for defining animal breeding goals with ethical priorities and weighing of market and non-market values is suggested. Implementation of non-market as well as market economic trait values in the aggregate genotype, as suggested, may allow for breeding programs that contribute to sustainable production systems. Examples of breeding goals in salmon, cattle, and pigs are given, and the resulting genetic responses are evaluated with respect to economic profit (or costs) and other criteria of sustainability. Important prerequisites for breeding programs for sustainable production are appropriate governmental policies, awareness of our way of thinking, and a more communal worldview informed by a subjective epistemology and a holistic ontology. PMID:10764063

  8. An Ethanol Vapor Chamber System for Small Animals

    PubMed Central

    Wang, Jie; Jiang, Lihong; Du, Hongying; Mason, Graeme F.

    2012-01-01

    Ethanol vapor chambers have been utilized widely in alcohol research since their introduction in 1971, and implementations of these systems are now available commercially. Here, we present a modification of the chamber that can be built at lower cost and greater simplicity of operation. The six-chamber system for rats has multiple air pumps. Ethanol vapor levels are adjusted with the air flow rate, ethanol drip rate, and dilution with room air, without a heater or fans. Ethanol vapor concentrations are measured with a breathalyzer, using room air to dilute the vapor chamber output into the range of the breathalyzer. Multiple pumps provide backup to ensure animal survival in the case of failure of the primary air pump. Tests in animals demonstrated comfortable and stable elevation of blood ethanol, with tight control of the ethanol vapor concentrations and the ability to select from a broad range of levels. The ethanol vapor measurement was rapid and efficient. The parts cost was a few thousand U.S. dollars. This vapor chamber system features low cost, ease of use, and convenient and inexpensive measurement of ethanol vapor concentrations. The lack of a heater and electrical components that could come into contact with ethanol in our case facilitated institutional approval. PMID:22575431

  9. A Time Domain Fluorescence Tomography System for Small Animal Imaging

    PubMed Central

    Raymond, Scott B.; Dunn, Andrew K.; Bacskai, Brian J.; Boas, David A.

    2010-01-01

    We describe the application of a time domain diffuse fluorescence tomography system for whole body small animal imaging. The key features of the system are the use of point excitation in free space using ultrashort laser pulses and noncontact detection using a gated, intensified charge-coupled device (CCD) camera. Mouse shaped epoxy phantoms, with embedded fluorescent inclusions, were used to verify the performance of a recently developed asymptotic lifetime-based tomography algorithm. The asymptotic algorithm is based on a multiexponential analysis of the decay portion of the data. The multiexponential model is shown to enable the use of a global analysis approach for a robust recovery of the lifetime components present within the imaging medium. The surface boundaries of the imaging volume were acquired using a photogrammetric camera integrated with the imaging system, and implemented in a Monte-Carlo model of photon propagation in tissue. The tomography results show that the asymptotic approach is able to separate axially located fluorescent inclusions centered at depths of 4 and 10 mm from the surface of the mouse phantom. The fluorescent inclusions had distinct lifetimes of 0.5 and 0.95 ns. The inclusions were nearly overlapping along the measurement axis and shown to be not resolvable using continuous wave (CW) methods. These results suggest the practical feasibility and advantages of a time domain approach for whole body small animal fluorescence molecular imaging, particularly with the use of lifetime as a contrast mechanism. PMID:18672432

  10. An ethanol vapor chamber system for small animals.

    PubMed

    Wang, Jie; Jiang, Lihong; Du, Hongying; Mason, Graeme F

    2012-06-30

    Ethanol vapor chambers have been utilized widely in alcohol research since their introduction in 1971, and implementations of these systems are now available commercially. Here, we present a modification of the chamber that can be built at lower cost and greater simplicity of operation. The six-chamber system for rats has multiple air pumps. Ethanol vapor levels are adjusted with the air flow rate, ethanol drip rate, and dilution with room air, without a heater or fans. Ethanol vapor concentrations are measured with a breathalyzer, using room air to dilute the vapor chamber output into the range of the breathalyzer. Multiple pumps provide backup to ensure animal survival in the case of failure of the primary air pump. Tests in animals demonstrated comfortable and stable elevation of blood ethanol, with tight control of the ethanol vapor concentrations and the ability to select from a broad range of levels. The ethanol vapor measurement was rapid and efficient. The parts cost was a few thousand U.S. dollars. This vapor chamber system features low cost, ease of use, and convenient and inexpensive measurement of ethanol vapor concentrations. The lack of a heater and electrical components that could come into contact with ethanol in our case facilitated institutional approval. PMID:22575431

  11. Using adaptive neuro-fuzzy inference system technique for crosstalk correction in simultaneous 99mTc/201Tl SPECT imaging: A Monte Carlo simulation study

    NASA Astrophysics Data System (ADS)

    Heidary, Saeed; Setayeshi, Saeed

    2015-01-01

    This work presents a simulation based study by Monte Carlo which uses two adaptive neuro-fuzzy inference systems (ANFIS) for cross talk compensation of simultaneous 99mTc/201Tl dual-radioisotope SPECT imaging. We have compared two neuro-fuzzy systems based on fuzzy c-means (FCM) and subtractive (SUB) clustering. Our approach incorporates eight energy-windows image acquisition from 28 keV to 156 keV and two main photo peaks of 201Tl (77±10% keV) and 99mTc (140±10% keV). The Geant4 application in emission tomography (GATE) is used as a Monte Carlo simulator for three cylindrical and a NURBS Based Cardiac Torso (NCAT) phantom study. Three separate acquisitions including two single-isotopes and one dual isotope were performed in this study. Cross talk and scatter corrected projections are reconstructed by an iterative ordered subsets expectation maximization (OSEM) algorithm which models the non-uniform attenuation in the projection/back-projection. ANFIS-FCM/SUB structures are tuned to create three to sixteen fuzzy rules for modeling the photon cross-talk of the two radioisotopes. Applying seven to nine fuzzy rules leads to a total improvement of the contrast and the bias comparatively. It is found that there is an out performance for the ANFIS-FCM due to its acceleration and accurate results.

  12. Comparison of transmission acquisition approaches for SPECT nonuniform attenuation compensation

    SciTech Connect

    Gilland, D.R.; Jaszczak, R.J.; Turkington, T.G.; Coleman, R.E.

    1998-06-01

    This study compared two approaches for acquiring transmission computed tomography (TCT) data for SPECT nonuniform attenuation compensation. One approach, which has been implemented in commercial SPECT systems, acquires the TCT and SPECT data simultaneously using a scanning transmission line source, dual head SPECT system and parallel beam collimation (PB-sim). The other approach acquires the TCT and SPECT data sequentially using long focus, off-set fan beam collimation with a non-scanning line source and a triple head system (FB-seq). The two systems were compared based on: (a) the noise level of the TCT projection data, (b) the spatial resolution of the TCT projection data, and (c) the quality of reconstructed TCT and SPECT images of a thorax phantom. For the thorax phantom data a fast TCT scan (2 min.) was used and total scan time (TCT and SPECT) was the same for the two systems. The results from the TCT noise measurements showed that for the source activities used here (400 mCi for PB-sim, 56 mCi for FB-seq), PB-sim had higher in the heart and liver regions. The measured TCT spatial resolution for the two systems was comparable in the axial direction but was superior with FB-seq in the transaxial direction. The resolution difference was apparent in the reconstructed TCT images. These results suggest that the FB-seq system offers a viable approach for TCT acquisition and one that compares favorably with current commercial approaches based on TCT noise, resolution and reconstructed image quality.

  13. Coregistration of datasets from a micro-SPECT/CT and a preclinical 1.5 T MRI

    NASA Astrophysics Data System (ADS)

    Dillenseger, J.-P.; Guillaud, B.; Goetz, C.; Sayeh, A.; Schimpf, R.; Constantinesco, A.; Choquet, P.

    2013-02-01

    An universal tool was designed for small animal SPECT/CT/MR coregistration. It was tested on a preclinical MRI (OPTImouse, RS2D, Bischwiller, France) and a micro-SPECT/CT (eXplore speCZT Vision 120, GE, Waukesha, USA), closed to each other, thanks to the short extension of the MRI magnet fringe field. The tool consists of a curved catheter describing many rigid loops, and fixed on a plastic sheet. During acquisitions, it is placed around the animal, in an isolated imaging cell, and filled with a solution containing iodine, copper sulfate and radioisotope. Multimodality imaging is achieved sequentially by moving the cell from one system to the other, in about 20 s. Acquisitions on phantom demonstrate the resolution accuracy of the coregistration process. Whole body trimodal SPECT/CT/MR acquisitions on live mice were coregistrated as well. A simple, cheap tool, easy to fill, could efficiently help for rigid coregistration of preclinical images, acquired on separate imaging apparatus.

  14. [Animals (Animalia) in system of organisms. 2. Phylogenetic understanding of animals].

    PubMed

    Shatalkin, A I

    2005-01-01

    may be through different and crossed classifications. Inside the given category of groups it is possible to distinguish: (2.1) Level of the organization (grade) described by the differences on the levels of organization: for example prokaryotic and eukaryotic levels of the organization. Eukaryotes can be divided into unicellular (Protoctista, Protista) and multicelluar (tissue-specific-Histonia) forms. (2.2) Types of the organization distinguishing groups of one level: for example, amoedoid type (Sarcodina), naked (Gymnamoebia), and testate (Testacea) amoebas. (2.3) Taxonomic groups as set-theoretical approximations of taxa. (2.4) Groups of the mixed nature. For example, Haeckel has recognized Protophyta and Protozoa describing the unicellular level of the organization inside plants and animals accordingly. Protozoa in Cavalier-Smith's system (2002, 2004) is also an example of groups of the mixed nature. PMID:16245570

  15. Hybrid SPECT/CT imaging in neurology.

    PubMed

    Ciarmiello, Andrea; Giovannini, Elisabetta; Meniconi, Martina; Cuccurullo, Vincenzo; Gaeta, Maria Chiara

    2014-01-01

    In recent years, the SPECT/CT hybrid modality has led to a rapid development of imaging techniques in nuclear medicine, opening new perspectives for imaging staff and patients as well. However, while, the clinical role of positron emission tomography-computed tomography (PET-CT) is well consolidated, the diffusion and the consequent value of single-photon emission tomography-computed tomography (SPECT-CT) has yet to be weighed, Hence, there is a need for a careful analysis, comparing the "potential" benefits of the hybrid modality with the "established" ones of the standalone machine. The aim of this article is to analyze the impact of this hybrid tool on the diagnosis of diseases of the central nervous system, comparing strengths and weaknesses of both modalities through the use of SWOT analysis. PMID:25143053

  16. Development of a triple modality small animal planar imaging system

    SciTech Connect

    A. G. Weisenberger, Z. Lee, S. Majewski, B. Kross, V. Popov, B. Welch, R. Wojcik, C. Zorn

    2006-02-01

    Recently small animal research utilizing nuclear medicine based imaging has been combined with structural anatomical imaging from x-ray radiography providing a powerful tool for animal researchers. The addition of a third modality is the goal of our instrumentation development. Thomas Jefferson National Accelerator Facility and Case Western Reserve University have been collaborating on the development of a planar imaging system which in addition to radiopharmaceutical based functional imaging and x-ray radiography structural imaging also allows for the in vivo bioluminescence imaging thus providing another functional imaging modality. For the gamma camera we use is a Hamamatsu position sensitive photomultiplier tube coupled to a pixellated NaI(TI) scintillator array with individual crystal elements 1 mm × 1 mm × 5 mm in size and a 0.25 mm septum between each element. The gamma camera has a 10 cm diameter active area and can be used for 125I, 99mT and 111In radionuclide imaging. To acquire anatomical information we are using a Rad-Icon Shad-o-Box X-ray detector that provides a field of view of 5 cm × 10 cm. The x-ray source is a Source-Ray compact x-ray generator. We are using a Princeton Instruments cooled CCD based detector for the imaging of the bio-distribution of bioluminescence. All three imaging instruments will be integrated into a single light tight / x-ray tight enclosure.

  17. Method and apparatus for animal positioning in imaging systems

    SciTech Connect

    Hadjioannou, Arion-Xenofon; Stout, David B.; Silverman, Robert W.

    2013-01-01

    An apparatus for imaging an animal includes a first mounting surface, a bed sized to support the animal and releasably secured to or integral with the first mounting surface. The apparatus also includes a plurality of straps, each having a first end in a fixed position relative to the bed and a second end for tightening around a limb of the animal. A method for in-vivo imaging of an animal includes providing an animal that has limbs, providing a first mounting surface, and providing a bed removably secured to or integral with the mounting surface and sized to support the animal as well as being coupled to a plurality of straps. The method also includes placing the animal on the bed between the plurality of straps and tightening at least two of the plurality of straps around at least two of the limbs such that the animal is substantially secured in place relative to the bed.

  18. SPECT detectors: the Anger Camera and beyond

    PubMed Central

    Peterson, Todd E.; Furenlid, Lars R.

    2011-01-01

    The development of radiation detectors capable of delivering spatial information about gamma-ray interactions was one of the key enabling technologies for nuclear medicine imaging and, eventually, single-photon emission computed tomography (SPECT). The continuous NaI(Tl) scintillator crystal coupled to an array of photomultiplier tubes, almost universally referred to as the Anger Camera after its inventor, has long been the dominant SPECT detector system. Nevertheless, many alternative materials and configurations have been investigated over the years. Technological advances as well as the emerging importance of specialized applications, such as cardiac and preclinical imaging, have spurred innovation such that alternatives to the Anger Camera are now part of commercial imaging systems. Increased computing power has made it practical to apply advanced signal processing and estimation schemes to make better use of the information contained in the detector signals. In this review we discuss the key performance properties of SPECT detectors and survey developments in both scintillator and semiconductor detectors and their readouts with an eye toward some of the practical issues at least in part responsible for the continuing prevalence of the Anger Camera in the clinic. PMID:21828904

  19. SPECT detectors: the Anger Camera and beyond.

    PubMed

    Peterson, Todd E; Furenlid, Lars R

    2011-09-01

    The development of radiation detectors capable of delivering spatial information about gamma-ray interactions was one of the key enabling technologies for nuclear medicine imaging and, eventually, single-photon emission computed tomography (SPECT). The continuous sodium iodide scintillator crystal coupled to an array of photomultiplier tubes, almost universally referred to as the Anger Camera after its inventor, has long been the dominant SPECT detector system. Nevertheless, many alternative materials and configurations have been investigated over the years. Technological advances as well as the emerging importance of specialized applications, such as cardiac and preclinical imaging, have spurred innovation such that alternatives to the Anger Camera are now part of commercial imaging systems. Increased computing power has made it practical to apply advanced signal processing and estimation schemes to make better use of the information contained in the detector signals. In this review we discuss the key performance properties of SPECT detectors and survey developments in both scintillator and semiconductor detectors and their readouts with an eye toward some of the practical issues at least in part responsible for the continuing prevalence of the Anger Camera in the clinic. PMID:21828904

  20. SPECT detectors: the Anger Camera and beyond

    NASA Astrophysics Data System (ADS)

    Peterson, Todd E.; Furenlid, Lars R.

    2011-09-01

    The development of radiation detectors capable of delivering spatial information about gamma-ray interactions was one of the key enabling technologies for nuclear medicine imaging and, eventually, single-photon emission computed tomography (SPECT). The continuous sodium iodide scintillator crystal coupled to an array of photomultiplier tubes, almost universally referred to as the Anger Camera after its inventor, has long been the dominant SPECT detector system. Nevertheless, many alternative materials and configurations have been investigated over the years. Technological advances as well as the emerging importance of specialized applications, such as cardiac and preclinical imaging, have spurred innovation such that alternatives to the Anger Camera are now part of commercial imaging systems. Increased computing power has made it practical to apply advanced signal processing and estimation schemes to make better use of the information contained in the detector signals. In this review we discuss the key performance properties of SPECT detectors and survey developments in both scintillator and semiconductor detectors and their readouts with an eye toward some of the practical issues at least in part responsible for the continuing prevalence of the Anger Camera in the clinic.

  1. A simple integrated system for electrophysiologic recordings in animals

    PubMed Central

    Slater, Bernard J.; Miller, Neil R.; Bernstein, Steven L.; Flower, Robert W.

    2009-01-01

    This technical note describes a modification to a fundus camera that permits simultaneous recording of pattern electroretinograms (pERGs) and pattern visual evoked potentials (pVEPs). The modification consists of placing an organic light-emitting diode (OLED) in the split-viewer pathway of a fundus camera, in a plane conjugate to the subject’s pupil. In this way, a focused image of the OLED can be delivered to a precisely known location on the retina. The advantage of using an OLED is that it can achieve high luminance while maintaining high contrast, and with minimal degradation over time. This system is particularly useful for animal studies, especially when precise retinal positioning is required. PMID:19137347

  2. Comprehending emergent systems phenomena through direct-manipulation animation

    NASA Astrophysics Data System (ADS)

    Aguirre, Priscilla Abel

    This study seeks to understand the type of interaction mode that best supports learning and comprehension of emergent systems phenomena. Given that the literature has established that students hold robust misconceptions of such phenomena, this study investigates the influence of using three types of interaction; speed-manipulation animation (SMN), post-manipulation animation (PMA) and direct-manipulation animation (DMA) for increasing comprehension and testing transfer of the phenomena, by looking at the effect of simultaneous interaction of haptic and visual channels on long term and working memories when seeking to comprehend emergent phenomena. The questions asked were: (1) Does the teaching of emergent phenomena, with the aid of a dynamic interactive modeling tool (i.e., SMA, PMA or DMA), improve students' mental model construction of systems, thus increasing comprehension of this scientific concept? And (2) does the teaching of emergent phenomena, with the aid of a dynamic interactive modeling tool, give the students the necessary complex cognitive skill which can then be applied to similar (near transfer) and/or novel, but different, (far transfer) scenarios? In an empirical study undergraduate and graduate students were asked to participate in one of three experimental conditions: SMA, PMA, or DMA. The results of the study found that it was the participants of the SMA treatment condition that had the most improvement in post-test scores. Students' understanding of the phenomena increased most when they used a dynamic model with few interactive elements (i.e., start, stop, and speed) that allowed for real time visualization of one's interaction on the phenomena. Furthermore, no indication was found that the learning of emergent phenomena, with the aid of a dynamic interactive modeling tool, gave the students the necessary complex cognitive skill which could then be applied to similar (near transfer) and/or novel, but different, (far transfer) scenarios

  3. Geometric characterization of multi-axis multi-pinhole SPECT

    SciTech Connect

    DiFilippo, Frank P.

    2008-01-15

    A geometric model and calibration process are developed for single photon emission computed tomography (SPECT) imaging with multiple pinholes and multiple mechanical axes. Unlike the typical situation where pinhole collimators are mounted directly to rotating gamma ray detectors, this geometric model allows for independent rotation of the detectors and pinholes, for the case where the pinhole collimator is physically detached from the detectors. This geometric model is applied to a prototype small animal SPECT device with a total of 22 pinholes and which uses dual clinical SPECT detectors. All free parameters in the model are estimated from a calibration scan of point sources and without the need for a precision point source phantom. For a full calibration of this device, a scan of four point sources with 360 deg. rotation is suitable for estimating all 95 free parameters of the geometric model. After a full calibration, a rapid calibration scan of two point sources with 180 deg. rotation is suitable for estimating the subset of 22 parameters associated with repositioning the collimation device relative to the detectors. The high accuracy of the calibration process is validated experimentally. Residual differences between predicted and measured coordinates are normally distributed with 0.8 mm full width at half maximum and are estimated to contribute 0.12 mm root mean square to the reconstructed spatial resolution. Since this error is small compared to other contributions arising from the pinhole diameter and the detector, the accuracy of the calibration is sufficient for high resolution small animal SPECT imaging.

  4. Accelerated GPU based SPECT Monte Carlo simulations.

    PubMed

    Garcia, Marie-Paule; Bert, Julien; Benoit, Didier; Bardiès, Manuel; Visvikis, Dimitris

    2016-06-01

    Monte Carlo (MC) modelling is widely used in the field of single photon emission computed tomography (SPECT) as it is a reliable technique to simulate very high quality scans. This technique provides very accurate modelling of the radiation transport and particle interactions in a heterogeneous medium. Various MC codes exist for nuclear medicine imaging simulations. Recently, new strategies exploiting the computing capabilities of graphical processing units (GPU) have been proposed. This work aims at evaluating the accuracy of such GPU implementation strategies in comparison to standard MC codes in the context of SPECT imaging. GATE was considered the reference MC toolkit and used to evaluate the performance of newly developed GPU Geant4-based Monte Carlo simulation (GGEMS) modules for SPECT imaging. Radioisotopes with different photon energies were used with these various CPU and GPU Geant4-based MC codes in order to assess the best strategy for each configuration. Three different isotopes were considered: (99m) Tc, (111)In and (131)I, using a low energy high resolution (LEHR) collimator, a medium energy general purpose (MEGP) collimator and a high energy general purpose (HEGP) collimator respectively. Point source, uniform source, cylindrical phantom and anthropomorphic phantom acquisitions were simulated using a model of the GE infinia II 3/8" gamma camera. Both simulation platforms yielded a similar system sensitivity and image statistical quality for the various combinations. The overall acceleration factor between GATE and GGEMS platform derived from the same cylindrical phantom acquisition was between 18 and 27 for the different radioisotopes. Besides, a full MC simulation using an anthropomorphic phantom showed the full potential of the GGEMS platform, with a resulting acceleration factor up to 71. The good agreement with reference codes and the acceleration factors obtained support the use of GPU implementation strategies for improving computational

  5. Accelerated GPU based SPECT Monte Carlo simulations

    NASA Astrophysics Data System (ADS)

    Garcia, Marie-Paule; Bert, Julien; Benoit, Didier; Bardiès, Manuel; Visvikis, Dimitris

    2016-06-01

    Monte Carlo (MC) modelling is widely used in the field of single photon emission computed tomography (SPECT) as it is a reliable technique to simulate very high quality scans. This technique provides very accurate modelling of the radiation transport and particle interactions in a heterogeneous medium. Various MC codes exist for nuclear medicine imaging simulations. Recently, new strategies exploiting the computing capabilities of graphical processing units (GPU) have been proposed. This work aims at evaluating the accuracy of such GPU implementation strategies in comparison to standard MC codes in the context of SPECT imaging. GATE was considered the reference MC toolkit and used to evaluate the performance of newly developed GPU Geant4-based Monte Carlo simulation (GGEMS) modules for SPECT imaging. Radioisotopes with different photon energies were used with these various CPU and GPU Geant4-based MC codes in order to assess the best strategy for each configuration. Three different isotopes were considered: 99m Tc, 111In and 131I, using a low energy high resolution (LEHR) collimator, a medium energy general purpose (MEGP) collimator and a high energy general purpose (HEGP) collimator respectively. Point source, uniform source, cylindrical phantom and anthropomorphic phantom acquisitions were simulated using a model of the GE infinia II 3/8" gamma camera. Both simulation platforms yielded a similar system sensitivity and image statistical quality for the various combinations. The overall acceleration factor between GATE and GGEMS platform derived from the same cylindrical phantom acquisition was between 18 and 27 for the different radioisotopes. Besides, a full MC simulation using an anthropomorphic phantom showed the full potential of the GGEMS platform, with a resulting acceleration factor up to 71. The good agreement with reference codes and the acceleration factors obtained support the use of GPU implementation strategies for improving computational efficiency

  6. In vivo SPECT and ex vivo autoradiographic brain imaging of the novel selective CB1 receptor antagonist radioligand [125I]SD7015 in CB1 knock-out and wildtype mouse.

    PubMed

    Máthé, Domokos; Horváth, Ildikó; Szigeti, Krisztián; Donohue, Sean R; Pike, Victor W; Jia, Zisheng; Ledent, Catherine; Palkovits, Miklós; Freund, Tamás F; Halldin, Christer; Gulyás, Balázs

    2013-02-01

    We aimed to evaluate the novel high-affinity and relatively lipophilic CB(1) receptor (CB(1)R) antagonist radioligand [(125)I]SD7015 for SPECT imaging of CB(1)Rs in vivo using the multiplexed multipinhole dedicated small animal SPECT/CT system, NanoSPECT/CT(PLUS) (Mediso, Budapest, Hungary), in knock-out CB(1) receptor knock-out (CB(1)R-/-) and wildtype mice. In order to exclude possible differences in cerebral blood flow between the two types of animals, HMPAO SPECT scans were performed, whereas in order to confirm the brain uptake differences of the radioligand between knock-out mice and wildtype mice, in vivo scans were complemented with ex vivo autoradiographic measurements using the brains of the same animals. With SPECT/CT imaging, we measured the brain uptake of radioactivity, using %SUV (% standardised uptake values) in CB(1)R-/- mice (n=3) and C57BL6 wildtype mice (n=7) under urethane anaesthesia after injecting [(125)I]SD7015 intravenously or intraperitoneally. The Brookhaven Laboratory mouse MRI atlas was fused to the SPECT/CT images by using a combination of rigid and non-rigid algorithms in the Mediso Fusion™ (Mediso, Budapest, Hungary) and VivoQuant (inviCRO, Boston, MA, USA) softwares. Phosphor imager plate autoradiography (ARG) was performed on 4 μm-thin cryostat sections of the excised brains. %SUV was 8.6±3.6 (average±SD) in CB(1)R-/- mice and 22.1±12.4 in wildtype mice between 2 and 4 h after injection (p<0.05). ARG of identically taken sections from wildtype mouse brain showed moderate radioactivity uptake when compared with the in vivo images, with a clear difference between grey matter and white matter, whereas ARG in CB(1)R(-/-) mice showed practically no radioactivity uptake. [(125)I]SD7015 enters the mouse brain in sufficient amount to enable SPECT imaging. Brain radioactivity distribution largely coincides with that of the known CB(1)R expression pattern in rodent brain. We conclude that [(125)I]SD7015 should be a useful SPECT

  7. In vivo SPECT and ex vivo autoradiographic brain imaging of the novel selective CB1 receptor antagonist radioligand [125I]SD7015 in CB1 knock-out and wildtype mouse

    PubMed Central

    Máthé, Domokos; Horváth, Ildikó; Szigeti, Krisztián; Donohue, Sean R.; Pike, Victor W.; Jia, Zisheng; Ledent, Catherine; Palkovits, Miklós; Freund, Tamás F.; Halldin, Christer; Gulyás, Balázs

    2014-01-01

    We aimed to evaluate the novel high-affinity and relatively lipophilic CB1 receptor (CB1R) antagonist radioligand [125I]SD7015 for SPECT imaging of CB1Rs in vivo using the multiplexed multipinhole dedicated small animal SPECT/CT system, NanoSPECT/CTPLUS (Mediso, Budapest, Hungary), in knock-out CB1 receptor knock-out (CB1R-/-) and wildtype mice. In order to exclude possible differences in cerebral blood flow between the two types of animals, HMPAO SPECT scans were performed, whereas in order to confirm the brain uptake differences of the radioligand between knock-out mice and wildtype mice, in vivo scans were complemented with ex vivo autoradiographic measurements using the brains of the same animals. With SPECT/CT imaging, we measured the brain uptake of radioactivity, using %SUV (% standardised uptake values) in CB1R-/- mice (n = 3) and C57BL6 wildtype mice (n = 7) under urethane anaesthesia after injecting [125I]SD7015 intravenously or intraperitoneally. The Brookhaven Laboratory mouse MRI atlas was fused to the SPECT/CT images by using a combination of rigid and non-rigid algorithms in the Mediso Fusion™ (Mediso, Budapest, Hungary) and VivoQuant (inviCRO, Boston, MA, USA) softwares. Phosphor imager plate autoradiography (ARG) was performed on 4 μm-thin cryostat sections of the excised brains. %SUV was 8.6 ± 3.6 (average ± SD) in CB1R-/- mice and 22.1 ± 12.4 in wildtype mice between 2 and 4 h after injection (p < 0.05). ARG of identically taken sections from wildtype mouse brain showed moderate radioactivity uptake when compared with the in vivo images, with a clear difference between grey matter and white matter, whereas ARG in CB1R(-/-) mice showed practically no radioactivity uptake. [125I]SD7015 enters the mouse brain in sufficient amount to enable SPECT imaging. Brain radioactivity distribution largely coincides with that of the known CB1R expression pattern in rodent brain. We conclude that [125I]SD7015 should be a useful SPECT radioligand for

  8. Multipinhole SPECT helical scan parameters and imaging volume

    SciTech Connect

    Yao, Rutao Deng, Xiao; Wei, Qingyang; Dai, Tiantian; Ma, Tianyu; Lecomte, Roger

    2015-11-15

    Purpose: The authors developed SPECT imaging capability on an animal PET scanner using a multiple-pinhole collimator and step-and-shoot helical data acquisition protocols. The objective of this work was to determine the preferred helical scan parameters, i.e., the angular and axial step sizes, and the imaging volume, that provide optimal imaging performance. Methods: The authors studied nine helical scan protocols formed by permuting three rotational and three axial step sizes. These step sizes were chosen around the reference values analytically calculated from the estimated spatial resolution of the SPECT system and the Nyquist sampling theorem. The nine helical protocols were evaluated by two figures-of-merit: the sampling completeness percentage (SCP) and the root-mean-square (RMS) resolution. SCP was an analytically calculated numerical index based on projection sampling. RMS resolution was derived from the reconstructed images of a sphere-grid phantom. Results: The RMS resolution results show that (1) the start and end pinhole planes of the helical scheme determine the axial extent of the effective field of view (EFOV), and (2) the diameter of the transverse EFOV is adequately calculated from the geometry of the pinhole opening, since the peripheral region beyond EFOV would introduce projection multiplexing and consequent effects. The RMS resolution results of the nine helical scan schemes show optimal resolution is achieved when the axial step size is the half, and the angular step size is about twice the corresponding values derived from the Nyquist theorem. The SCP results agree in general with that of RMS resolution but are less critical in assessing the effects of helical parameters and EFOV. Conclusions: The authors quantitatively validated the effective FOV of multiple pinhole helical scan protocols and proposed a simple method to calculate optimal helical scan parameters.

  9. Animation of multi-flexible body systems and its use in control system design

    NASA Technical Reports Server (NTRS)

    Juengst, Carl; Stahlberg, Ron

    1993-01-01

    Animation can greatly assist the structural dynamicist and control system analyst with better understanding of how multi-flexible body systems behave. For multi-flexible body systems, the structural characteristics (mode frequencies, mode shapes, and damping) change, sometimes dramatically with large angles of rotation between bodies. With computer animation, the analyst can visualize these changes and how the system responds to active control forces and torques. A characterization of the type of system we wish to animate is presented. The lack of clear understanding of the above effects was a key element leading to the development of a multi-flexible body animation software package. The resulting animation software is described in some detail here, followed by its application to the control system analyst. Other applications of this software can be determined on an individual need basis. A number of software products are currently available that make the high-speed rendering of rigid body mechanical system simulation possible. However, such options are not available for use in rendering flexible body mechanical system simulations. The desire for a high-speed flexible body visualization tool led to the development of the Flexible Or Rigid Mechanical System (FORMS) software. This software was developed at the Center for Simulation and Design Optimization of Mechanical Systems at the University of Iowa. FORMS provides interactive high-speed rendering of flexible and/or rigid body mechanical system simulations, and combines geometry and motion information to produce animated output. FORMS is designed to be both portable and flexible, and supports a number of different user interfaces and graphical display devices. Additional features have been added to FORMS that allow special visualization results related to the nature of the flexible body geometric representations.

  10. Development of automatic movement analysis system for a small laboratory animal using image processing

    NASA Astrophysics Data System (ADS)

    Nagatomo, Satoshi; Kawasue, Kikuhito; Koshimoto, Chihiro

    2013-03-01

    Activity analysis in a small laboratory animal is an effective procedure for various bioscience fields. The simplest way to obtain animal activity data is just observation and recording manually, even though this is labor intensive and rather subjective. In order to analyze animal movement automatically and objectivity, expensive equipment is usually needed. In the present study, we develop animal activity analysis system by means of a template matching method with video recorded movements in laboratory animal at a low cost.

  11. Radiopharmaceuticals for SPECT cancer detection

    NASA Astrophysics Data System (ADS)

    Chernov, V. I.; Medvedeva, A. A.; Zelchan, R. V.; Sinilkin, I. G.; Stasyuk, E. S.; Larionova, L. A.; Slonimskaya, E. M.; Choynzonov, E. L.

    2016-08-01

    The purpose of the study was to assess the efficacy of single photon emission computed tomography (SPECT) with 199Tl and 99mTc-MIBI in the detection of breast, laryngeal and hypopharyngeal cancers. A total of 220 patients were included into the study: 120 patients with breast lesions (100 patients with breast cancer and 20 patients with benign breast tumors) and 100 patients with laryngeal/hypopharyngeal diseases (80 patients with laryngeal/hypopharyngeal cancer and 20 patients with benign laryngeal/hypopharyngeal lesions). No abnormal 199Tl uptake was seen in all patients with benign breast and laryngeal lesions, indicating a 100% specificity of 199Tl SPECT. In the breast cancer patients, the increased 199Tl uptake in the breast was visualized in 94.8% patients, 99mTc-MIBI—in 93.4% patients. The increased 199Tl uptake in axillary lymph nodes was detected in 60% patients, and 99mTc-MIBI—in 93.1% patients. In patients with laryngeal/hypopharyngeal cancer, the sensitivity of SPECT with 199Tl and 99mTc-MIBI was 95%. The 199Tl SPECT sensitivity in identification of regional lymph node metastases in the patients with laryngeal/hypopharyngeal cancer was 75% and the 99mTc-MIBI SPECT sensitivity was 17%. The data obtained showed that SPECT with 199Tl and 99mTc-MIBI can be used as one of the additional imaging methods in detection of tumors.

  12. Radiopharmaceuticals for SPECT Cancer Detection

    NASA Astrophysics Data System (ADS)

    Chernov, V. I.; Medvedeva, A. A.; Zelchan, R. V.; Sinilkin, I. G.; Stasyuk, E. S.; Larionova, L. A.; Slonimskaya, E. M.; Choynzonov, E. L.

    2016-06-01

    The purpose of the study was to assess the efficacy of single photon emission computed tomography (SPECT) with 199Tl and 99mTc-MIBI in the detection of breast, laryngeal and hypopharyngeal cancers. Materials and Methods: a total of 220 patients were included into the study. Of them, there were 120 patients with breast lesions (100 patients with breast cancer and 20 patients with benign breast tumors) and '00 patients with laryngeal/hypopharyngeal diseases (80 patients with laryngeal/hypopharyngeal cancer and 20 patients with benign laryngeal/hypopharyngeal lesions). Results: no abnormal 199Tl uptake was seen in all patients with benign breast and laryngeal lesions, indicating a 100% specificity of 199Tl SPECT. In breast cancer patients, increased 199Tl uptake in the breast was visualized in 94.8% patients, 99mTc-MIBI in 93.4% patients. Increased 199Tl uptake in axillary lymph nodes was detected in 60% patients and 99mTc-MIBI in 93.1% patients. In patients with laryngeal/hypopharyngeal cancer, sensitivity of SPECT with 199Tl and 99mTc-MIBI were 95%. The 199Tl SPECT sensitivity in identification of regional lymph node metastases in patients with laryngeal/hypopharyngeal cancer was 75% and the 99mTc-MIBI SPECT sensitivity was 17%. Conclusion: the data obtained show that SPECT with 199Tl and 99mTc-MIBI can be used as one of the additional imaging methods in detection of tumors.

  13. Comparison of ultra-high-resolution parallel-hole collimator materials based on the CdTe pixelated semiconductor SPECT system

    NASA Astrophysics Data System (ADS)

    Lee, Young-Jin; Ryu, Hyun-Ju; Lee, Seung-Wan; Park, Su-Jin; Kim, Hee-Joung

    2013-06-01

    Recently, many studies have sought to improve the sensitivity and spatial resolution of pixelated semiconductor detectors. Spatial resolution can be improved by using a pinhole or pixelated parallel-hole collimator with equal hole and pixel sizes. We compared a pinhole to a pixelated parallel-hole collimator and found that the pixelated parallel-hole collimator had higher sensitivity. Additionally, collimator materials with high absorption efficiency are often used because of their high spatial resolution. The purpose of this study was to compare the quality of images generated using a pixelated semiconductor single photon emission computed tomography (SPECT) system simulated with pixelated parallel-hole collimators of lead, tungsten, gold, and depleted uranium. We performed a simulation study of the PID 350 (Ajat Oy Ltd., Finland) CdTe pixelated semiconductor detector, which consists of small pixels (0.35×0.35 mm2), using a Geant4 Application for Tomographic Emission (GATE) simulation. Sensitivities and spatial resolutions were measured for the four collimator materials. To evaluate overall image performance, a hot-rod phantom was designed using GATE simulation. The results showed that with lead, sensitivity was 4.25%, 6.53%, and 10.28% higher than with tungsten, gold, and depleted uranium, respectively. Spatial resolution using depleted uranium was 3.19%, 4.19%, and 8.01% better than that of gold, tungsten, and lead, respectively. Sensitivity and spatial resolution showed little difference among the four types of collimator materials tested. It was difficult to visually distinguish between the reconstructed images of the hot-rod phantom for different collimator materials. The results are promising for notable cost reductions in collimator manufacturing while avoiding impractical and rare materials.

  14. The effect of high-resolution parallel-hole collimator materials with a pixelated semiconductor SPECT system at equivalent sensitivities: Monte Carlo simulation studies

    NASA Astrophysics Data System (ADS)

    Lee, Young-Jin; Kim, Dae-Hong; Kim, Hee-Joung

    2014-04-01

    In nuclear medicine, the use of a pixelated semiconductor detector with cadmium telluride (CdTe) or cadmium zinc telluride (CdZnTe) is of growing interest for new devices. Especially, the spatial resolution can be improved by using a pixelated parallel-hole collimator with equal holes and pixel sizes based on the above-mentioned detector. High-absorption and high-stopping-power pixelated parallel-hole collimator materials are often chosen because of their good spatial resolution. Capturing more gamma rays, however, may result in decreased sensitivity with the same collimator geometric designs. Therefore, a trade-off between spatial resolution and sensitivity is very important in nuclear medicine imaging. The purpose of this study was to compare spatial resolutions using a pixelated semiconductor single photon emission computed tomography (SPECT) system with lead, tungsten, gold, and depleted uranium pixelated parallel-hole collimators at equal sensitivity. We performed a simulation study of the PID 350 (Ajat Oy Ltd., Finland) CdTe pixelated semiconductor detector (pixel size: 0.35 × 0.35 mm2) by using a Geant4 Application for Tomographic Emission (GATE) simulation. Spatial resolutions were measured with different collimator materials at equivalent sensitivities. Additionally, hot-rod phantom images were acquired for each source-to-collimator distance by using a GATE simulation. At equivalent sensitivities, measured averages of the full width at half maximum (FWHM) using lead, tungsten, and gold were 4.32, 2.93, and 2.23% higher than that of depleted uranium, respectively. Furthermore, for the full width at tenth maximum (FWTM), measured averages when using lead, tungsten, and gold were 6.29, 4.10, and 2.65% higher than that of depleted uranium, respectively. Although, the spatial resolution showed little differences among the different pixelated parallel-hole collimator materials, lower absorption and stopping power materials such as lead and tungsten had

  15. Recent developments and future prospects of SPECT myocardial perfusion imaging.

    PubMed

    Zaman, Maseeh Uz; Hashmi, Ibrahim; Fatima, Nosheen

    2010-10-01

    Myocardial perfusion SPECT imaging is the most commonly performed functional imaging for assessment of coronary artery disease. High diagnostic accuracy and incremental prognostic value are the major benefits while suboptimal spatial resolution and significant radiation exposure are the main limitations. Its ability to detect hemodynamic significance of lesions seen on multidetector CT angiogram (MDCTA) has paved the path for a successful marriage between anatomical and functional imaging modalities in the form of hybrid SPECT/MDCTA system. In recent years, there have been enormous efforts by industry and academia to develop new SPECT imaging systems with better sensitivity, resolution, compact design and new reconstruction algorithms with ability to improve image quality and resolution. Furthermore, expected arrival of Tc-99m-labeled deoxyglucose in next few years would further strengthen the role of SPECT in imaging hibernating myocardium. In view of these developments, it seems that SPECT would enjoy its pivotal role in spite of major threat to be replaced by fluorine-18-labeled positron emission tomography perfusion and glucose metabolism imaging agents. PMID:20652774

  16. Learning about Skeletons and Other Organ Systems of Vertebrate Animals.

    ERIC Educational Resources Information Center

    Tunnicliffe, Sue Dale; Reiss, Michael

    1999-01-01

    Describes students' (n=175) understandings of the structure of animal (including human) skeletons and the internal organs found in them. Finds that older students have a better knowledge of animals' internal anatomies, although knowledge of human internal structure is significantly better than knowledge of rat, bird, and fish internal structure.…

  17. GATE simulation of a LYSO-based SPECT imager: Validation and detector optimization

    NASA Astrophysics Data System (ADS)

    Li, Suying; Zhang, Qiushi; Xie, Zhaoheng; Liu, Qi; Xu, Baixuan; Yang, Kun; Li, Changhui; Ren, Qiushi

    2015-02-01

    This paper presents a small animal SPECT system that is based on cerium doped lutetium-yttrium oxyorthosilicate (LYSO) scintillation crystal, position sensitive photomultiplier tubes (PSPMTs) and parallel hole collimator. Spatial resolution test and animal experiment were performed to demonstrate the imaging performance of the detector. Preliminary results indicated a spatial resolution of 2.5 mm at FWHM that cannot meet our design requirement. Therefore, we simulated this gamma camera using GATE (GEANT 4 Application for Tomographic Emission) aiming to make detector spatial resolution less than 2 mm. First, the GATE simulation process was validated through comparison between simulated and experimental data. This also indicates the accuracy and effectiveness of GATE simulation for LYSO-based gamma camera. Then the different detector sampling methods (crystal size with 1.5, and 1 mm) and collimator design (collimator height with 30, 34.8, 38, and 43 mm) were studied to figure out an optimized parameter set. Detector sensitivity changes were also focused on with different parameters set that generated different spatial resolution results. Tradeoff curves of spatial resolution and sensitivity were plotted to determine the optimal collimator height with different sampling methods. Simulation results show that scintillation crystal size of 1 mm and collimator height of 38 mm, which can generate a spatial resolution of ~1.8 mm and sensitivity of ~0.065 cps/kBq, can be an ideal configuration for our SPECT imager design.

  18. SPECT Perfusion Imaging Demonstrates Improvement of Traumatic Brain Injury With Transcranial Near-infrared Laser Phototherapy.

    PubMed

    Henderson, Theodore A; Morries, Larry D

    2015-01-01

    Traumatic brain injury (TBI) is a growing health concern affecting civilians and military personnel. Near-infrared (NIR) light has shown benefits in animal models and human trials for stroke and in animal models for TBI. Diodes emitting low-level NIR often have lacked therapeutic efficacy, perhaps failing to deliver sufficient radiant energy to the necessary depth. In this case report, a patient with moderate TBI documented in anatomical magnetic resonance imaging (MRI) and perfusion single-photon emission computed tomography (SPECT) received 20 NIR treatments in the course of 2 mo using a high-power NIR laser. Symptoms were monitored by clinical examination and a novel patient diary system specifically designed for this patient population. Clinical application of these levels of infrared energy for this patient with TBI yielded highly favorable outcomes with decreased depression, anxiety, headache, and insomnia, whereas cognition and quality of life improved. Neurological function appeared to improve based on changes in the SPECT by quantitative analysis. NIR in the power range of 10-15 W at 810 and 980 nm can safely and effectively treat chronic symptoms of TBI. PMID:26535475

  19. Animals and the invention of the Phanerozoic Earth system.

    PubMed

    Butterfield, Nicholas J

    2011-02-01

    Animals do not just occupy the modern biosphere, they permeate its structure and define how it works. Their unique combination of organ-grade multicellularity, motility and heterotrophic habit makes them powerful geobiological agents, imposing myriad feedbacks on nutrient cycling, productivity and environment. Most significantly, animals have 'engineered' the biosphere over evolutionary time, forcing the diversification of, for example, phytoplankton, land plants, trophic structure, large body size, bioturbation, biomineralization and indeed the evolutionary process itself. This review surveys how animals contribute to the modern world and provides a basis for reconstructing ancient ecosystems. Earlier, less animal-influenced biospheres worked quite differently from the one currently occupied, with the Ediacaran-Cambrian radiation of organ-grade animals marking a fundamental shift in macroecological and macroevolutionary expression. PMID:21190752

  20. An isolated working heart system for large animal models.

    PubMed

    Schechter, Matthew A; Southerland, Kevin W; Feger, Bryan J; Linder, Dean; Ali, Ayyaz A; Njoroge, Linda; Milano, Carmelo A; Bowles, Dawn E

    2014-01-01

    Since its introduction in the late 19(th) century, the Langendorff isolated heart perfusion apparatus, and the subsequent development of the working heart model, have been invaluable tools for studying cardiovascular function and disease(1-15). Although the Langendorff heart preparation can be used for any mammalian heart, most studies involving this apparatus use small animal models (e.g., mouse, rat, and rabbit) due to the increased complexity of systems for larger mammals(1,3,11). One major difficulty is ensuring a constant coronary perfusion pressure over a range of different heart sizes - a key component of any experiment utilizing this device(1,11). By replacing the classic hydrostatic afterload column with a centrifugal pump, the Langendorff working heart apparatus described below allows for easy adjustment and tight regulation of perfusion pressures, meaning the same set-up can be used for various species or heart sizes. Furthermore, this configuration can also seamlessly switch between constant pressure or constant flow during reperfusion, depending on the user's preferences. The open nature of this setup, despite making temperature regulation more difficult than other designs, allows for easy collection of effluent and ventricular pressure-volume data. PMID:24962492

  1. Brain SPECT thallium using cadmium zinc telluride: a first experience.

    PubMed

    Farid, Karim; Queneau, Mathieu; Guernou, Mohamed; Lussato, David; Petras, Slavomir; Songy, Bernard

    2011-11-01

    A 70-year-old man underwent a thallium-201 brain SPECT in the work-up and characterization of a frontotemporal mass. SPECT images were performed on cadmium zinc telluride system during only 5 minutes and after the injection of only 2 mCi. Images demonstrated high thallium uptake in frontotemporal areas considered as a potential malignant tumor. Surgical removal confirmed the diagnosis of malignant glioblastoma. The thallium SPECT fast acquisition imaging on cadmium zinc telluride systems is feasible with reduced injected dose. This method allows a significantly decrease of patient radiation exposure without compromising the image quality. This initial experience needs to be confirmed and optimized in larger clinical studies. PMID:21975418

  2. A detector response function design in pinhole SPECT including geometrical calibration

    PubMed Central

    El Bitar, Z; Huesman, R H; Buchko, R; Bekaert, Virgile; Brasse, David; Gullberg, G T

    2014-01-01

    Clinical single photon emission computed tomography (SPECT) equipped with pinhole collimators have a magnification factor that results in high spatial resolution images for small animal imaging. Using Monte Carlo simulations to model the acquisition process and the propagation of the photons from their point of emission to their detection point then integrating the model into an iterative reconstruction algorithm improves the signal-to-noise ratio, the contrast and the spatial resolution in the reconstructed images. However, pinhole SPECT systems are known to be very sensitive to geometrical misalignments. Geometrical misalignments are defined as the radial or axial shift of the collimator pinhole and/or twist and tilt of the detector heads and are introduced in the system each time the collimation device is changed (pinhole to parallel holes or vice versa). In this work, we present a flexible detector response function table (DRFT) design that takes into account the geometrical misalignments and avoids performing new Monte Carlo simulations for each exam in order to calculate a geometrical study-dependent system matrix. The utilization of the DRFT for the calculation of the system matrix speeds up its computation time by two orders of magnitude making it acceptable for preclinical and clinical applications. PMID:23492938

  3. Automatic real-time pair-feeding system for animals

    NASA Technical Reports Server (NTRS)

    Leon, H. A.; Connolly, J. P.; Hitchman, M. J.; Humbert, J. E. (Inventor)

    1974-01-01

    A pair feeding method and apparatus are provided for experimental animals wherein the amount of food consumed is immediately delivered to a normal or control animal so that there is a qualitative, quantitative and chronological correctness in the pair feeding of the two animals. This feeding mechanism delivers precisely measured amounts of food to a feeder. Circuitry is provided between master and slave feeders so that there is virtually no chance of a malfunction of the feeding apparatus, causing erratic results. Recording equipment is also provided so that an hourly record is kept of food delivery.

  4. [Sensitivity of animals to central nervous system stimulants in hypokinesia].

    PubMed

    Kolemeeva, L Ia; Shashkov, V S; Egorov, B B

    1977-01-01

    The experiments were carried out on 1150 non-inbred white male rats weighing 200+/-50 g. The animals were housed in small cages for 1, 5, 10, 15, 30, 45 and 60 days. Control rats remained normally active. The experimental and control animals were given a typical diet. On the above days the rats were injected intraperitoneally with central nervous stimulants--caffeine, phenamine and strychnine. Changes in the animal sensitivity to the stimulants were measured with respect to the alterating of LD16, LD50 and LD54 in test animals as compared with the controls and in regards to the emergence and duration of behavioural reactions: adynamics (caffeine), stereotype behavior (phenamine) and convulsions (strychnine). The greatest changes in the animal sensitivity were noted in response to phenamine. A significant increase in the sensitivity to caffeine was found on the 5, 15 and 45th experimental days and to strychnine only on the 5 and 45th days. Convulsions in response to strychnine were recorded in experimental animals earlier than in the controls and their duration was dependent on the doses injected. Adynamics in response to caffeine developed in experimental rats later than in the controls (on the 15th day) and its duration changed cyclically. Stereotype behavior in response to phenamine showed cyclic pattern and its duration in experimental rats was shorter than in the controls. PMID:15162

  5. Progress in BazookaSPECT

    PubMed Central

    Miller, Brian W.; Barber, H. Bradford; Furenlid, Lars R.; Moore, Stephen K.; Barrett, Harrison H.

    2010-01-01

    Recent progress on a high-resolution, photon-counting gamma-ray and x-ray imager called BazookaSPECT is presented. BazookaSPECT is an example of a new class of scintillation detectors based on integrating detectors such as CCD(charge-coupled device) or CMOS(complementary metal-oxide semiconductor) sensors. BazookaSPECT is unique in that it makes use of a scintillator in close proximity to a microchannel plate-based image intensifier for up-front optical amplification of scintillation light. We discuss progress made in bringing about compact BazookaSPECT modules and in real-time processing of event data using graphics processing units (GPUs). These advances are being implemented in the design of a high-resolution rodent brain imager called FastSPECT III. A key benefit of up-front optical gain is that any CCD/CMOS sensor can now be utilized for photon counting. We discuss the benefits and feasibility of using CMOS sensors as photon-counting detectors for digital radiography, with application in mammography and computed tomography (CT). We present as an appendix a formal method for comparing various photon-counting integrating detectors using objective statistical criteria. PMID:21297897

  6. Performance evaluation of a novel high performance pinhole array detector module using NEMA NU-4 image quality phantom for four head SPECT Imaging

    NASA Astrophysics Data System (ADS)

    Rahman, Tasneem; Tahtali, Murat; Pickering, Mark R.

    2015-03-01

    Radiolabeled tracer distribution imaging of gamma rays using pinhole collimation is considered promising for small animal imaging. The recent availability of various radiolabeled tracers has enhanced the field of diagnostic study and is simultaneously creating demand for high resolution imaging devices. This paper presents analyses to represent the optimized parameters of a high performance pinhole array detector module using two different characteristics phantoms. Monte Carlo simulations using the Geant4 application for tomographic emission (GATE) were executed to assess the performance of a four head SPECT system incorporated with pinhole array collimators. The system is based on a pixelated array of NaI(Tl) crystals coupled to an array of position sensitive photomultiplier tubes (PSPMTs). The detector module was simulated to have 48 mm by 48 mm active area along with different pinhole apertures on a tungsten plate. The performance of this system has been evaluated using a uniform shape cylindrical water phantom along with NEMA NU-4 image quality (IQ) phantom filled with 99mTc labeled radiotracers. SPECT images were reconstructed where activity distribution is expected to be well visualized. This system offers the combination of an excellent intrinsic spatial resolution, good sensitivity and signal-to-noise ratio along with high detection efficiency over an energy range between 20-160 keV. Increasing number of heads in a stationary system configuration offers increased sensitivity at a spatial resolution similar to that obtained with the current SPECT system design with four heads.

  7. 40 CFR 160.90 - Animal and other test system care.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... PROGRAMS GOOD LABORATORY PRACTICE STANDARDS Testing Facilities Operation § 160.90 Animal and other test... 40 Protection of Environment 25 2013-07-01 2013-07-01 false Animal and other test system care. 160... as raw data. (h) Bedding used in animal cages or pens shall not interfere with the purpose or...

  8. 40 CFR 160.90 - Animal and other test system care.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... PROGRAMS GOOD LABORATORY PRACTICE STANDARDS Testing Facilities Operation § 160.90 Animal and other test... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Animal and other test system care. 160... as raw data. (h) Bedding used in animal cages or pens shall not interfere with the purpose or...

  9. Quantitative High-Efficiency Cadmium-Zinc-Telluride SPECT with Dedicated Parallel-Hole Collimation System in Obese Patients: Results of a Multi-Center Study

    PubMed Central

    Nakazato, Ryo; Slomka, Piotr J.; Fish, Mathews; Schwartz, Ronald G.; Hayes, Sean W.; Thomson, Louise E.J.; Friedman, John D.; Lemley, Mark; Mackin, Maria L.; Peterson, Benjamin; Schwartz, Arielle M.; Doran, Jesse A.; Germano, Guido; Berman, Daniel S.

    2014-01-01

    Background Obesity is a common source of artifact on conventional SPECT myocardial perfusion imaging (MPI). We evaluated image quality and diagnostic performance of high-efficiency (HE) cadmium-zinc-telluride (CZT) parallel-hole SPECT-MPI for coronary artery disease (CAD) in obese patients. Methods and Results 118 consecutive obese patients at 3 centers (BMI 43.6±8.9 kg/m2, range 35–79.7 kg/m2) had upright/supine HE-SPECT and ICA >6 months (n=67) or low-likelihood of CAD (n=51). Stress quantitative total perfusion deficit (TPD) for upright (U-TPD), supine (S-TPD) and combined acquisitions (C-TPD) was assessed. Image quality (IQ; 5=excellent; <3 nondiagnostic) was compared among BMI 35–39.9 (n=58), 40–44.9 (n=24) and ≥45 (n=36) groups. ROC-curve area for CAD detection (≥50% stenosis) for U-TPD, S-TPD, and C-TPD were 0.80, 0.80, and 0.87, respectively. Sensitivity/specificity was 82%/57% for U-TPD, 74%/71% for S-TPD, and 80%/82% for C-TPD. C-TPD had highest specificity (P=.02). C-TPD normalcy rate was higher than U-TPD (88% vs. 75%, P=.02). Mean IQ was similar among BMI 35–39.9, 40–44.9 and ≥45 groups [4.6 vs. 4.4 vs. 4.5, respectively (P=.6)]. No patient had a non-diagnostic stress scan. Conclusions In obese patients, HE-SPECT MPI with dedicated parallel-hole collimation demonstrated high image quality, normalcy rate, and diagnostic accuracy for CAD by quantitative analysis of combined upright/supine acquisitions. PMID:25388380

  10. Onboard functional and molecular imaging: A design investigation for robotic multipinhole SPECT

    SciTech Connect

    Bowsher, James Giles, William; Yin, Fang-Fang; Yan, Susu; Roper, Justin

    2014-01-15

    Purpose: Onboard imaging—currently performed primarily by x-ray transmission modalities—is essential in modern radiation therapy. As radiation therapy moves toward personalized medicine, molecular imaging, which views individual gene expression, may also be important onboard. Nuclear medicine methods, such as single photon emission computed tomography (SPECT), are premier modalities for molecular imaging. The purpose of this study is to investigate a robotic multipinhole approach to onboard SPECT. Methods: Computer-aided design (CAD) studies were performed to assess the feasibility of maneuvering a robotic SPECT system about a patient in position for radiation therapy. In order to obtain fast, high-quality SPECT images, a 49-pinhole SPECT camera was designed which provides high sensitivity to photons emitted from an imaging region of interest. This multipinhole system was investigated by computer-simulation studies. Seventeen hot spots 10 and 7 mm in diameter were placed in the breast region of a supine female phantom. Hot spot activity concentration was six times that of background. For the 49-pinhole camera and a reference, more conventional, broad field-of-view (FOV) SPECT system, projection data were computer simulated for 4-min scans and SPECT images were reconstructed. Hot-spot localization was evaluated using a nonprewhitening forced-choice numerical observer. Results: The CAD simulation studies found that robots could maneuver SPECT cameras about patients in position for radiation therapy. In the imaging studies, most hot spots were apparent in the 49-pinhole images. Average localization errors for 10-mm- and 7-mm-diameter hot spots were 0.4 and 1.7 mm, respectively, for the 49-pinhole system, and 3.1 and 5.7 mm, respectively, for the reference broad-FOV system. Conclusions: A robot could maneuver a multipinhole SPECT system about a patient in position for radiation therapy. The system could provide onboard functional and molecular imaging with 4-min

  11. Onboard functional and molecular imaging: A design investigation for robotic multipinhole SPECT

    PubMed Central

    Bowsher, James; Yan, Susu; Roper, Justin; Giles, William; Yin, Fang-Fang

    2014-01-01

    Purpose: Onboard imaging—currently performed primarily by x-ray transmission modalities—is essential in modern radiation therapy. As radiation therapy moves toward personalized medicine, molecular imaging, which views individual gene expression, may also be important onboard. Nuclear medicine methods, such as single photon emission computed tomography (SPECT), are premier modalities for molecular imaging. The purpose of this study is to investigate a robotic multipinhole approach to onboard SPECT. Methods: Computer-aided design (CAD) studies were performed to assess the feasibility of maneuvering a robotic SPECT system about a patient in position for radiation therapy. In order to obtain fast, high-quality SPECT images, a 49-pinhole SPECT camera was designed which provides high sensitivity to photons emitted from an imaging region of interest. This multipinhole system was investigated by computer-simulation studies. Seventeen hot spots 10 and 7 mm in diameter were placed in the breast region of a supine female phantom. Hot spot activity concentration was six times that of background. For the 49-pinhole camera and a reference, more conventional, broad field-of-view (FOV) SPECT system, projection data were computer simulated for 4-min scans and SPECT images were reconstructed. Hot-spot localization was evaluated using a nonprewhitening forced-choice numerical observer. Results: The CAD simulation studies found that robots could maneuver SPECT cameras about patients in position for radiation therapy. In the imaging studies, most hot spots were apparent in the 49-pinhole images. Average localization errors for 10-mm- and 7-mm-diameter hot spots were 0.4 and 1.7 mm, respectively, for the 49-pinhole system, and 3.1 and 5.7 mm, respectively, for the reference broad-FOV system. Conclusions: A robot could maneuver a multipinhole SPECT system about a patient in position for radiation therapy. The system could provide onboard functional and molecular imaging with 4-min

  12. An Intelligent Recommendation System for Animation Scriptwriters' Education

    ERIC Educational Resources Information Center

    Tsai, Shang-Te; Chang, Ting-Cheng; Huang, Yu-Feng

    2016-01-01

    Producing an animation requires extensive labor, time, and money. Experienced directors and screenwriters are required to design scenes using standard props and actors in position. This study structurally analyzes the script and defines scenes, characters, positions, dialogue, etc., according to their dramatic attributes. These are entered into a…

  13. Remote Laboratory and Animal Behaviour: An Interactive Open Field System

    ERIC Educational Resources Information Center

    Fiore, Lorenzo; Ratti, Giovannino

    2007-01-01

    Remote laboratories can provide distant learners with practical acquisitions which would otherwise remain precluded. Our proposal here is a remote laboratory on a behavioural test (open field test), with the aim of introducing learners to the observation and analysis of stereotyped behaviour in animals. A real-time video of a mouse in an…

  14. Designing an Algorithm Animation System To Support Instructional Tasks.

    ERIC Educational Resources Information Center

    Hamilton-Taylor, Ashley George; Kraemer, Eileen

    2002-01-01

    The authors are conducting a study of instructors teaching data structure and algorithm topics, with a focus on the use of diagrams and tracing. The results of this study are being used to inform the design of the Support Kit for Animation (SKA). This article describes a preliminary version of SKA, and possible usage scenarios. (Author/AEF)

  15. Comparison of Intrahepatic and Pancreatic Perfusion on Fusion Images Using a Combined SPECT/CT System and Assessment of Efficacy of Combined Continuous Arterial Infusion and Systemic Chemotherapy in Advanced Pancreatic Carcinoma

    SciTech Connect

    Ikeda, Osama Tamura, Yoshitaka; Nakasone, Yutaka; Shiraishi, Shinya; Kawanaka, Kouichi; Tomiguchi, Seiji; Yamashita, Yasuyuki; Takamori, Hiroshi; Kanemitsu, Keiichiro; Baba, Hideo

    2007-09-15

    Purpose. The purpose of this study was to compare intrahepatic and pancreatic perfusion on fusion images using a combined single-photon emission computed tomography (SPECT)/CT system and to evaluate the efficacy of combined continuous transcatheter arterial infusion (CTAI) and systemic chemotherapy in the treatment of advanced pancreatic carcinoma. Materials and Methods. CTAI was performed in 33 patients (22 men, 11 women; age range, 35-77 years; mean age, 60 years) with stage IV pancreatic cancer with liver metastasis. The reservoir was transcutaneously implanted with the help of angiography. The systemic administration of gemcitabine was combined with the infusion of 5-fluorouracil via the reservoir. In all patients we obtained fusion images using a combined SPECT/CT system. Pancreatic perfusion on fusion images was classified as perfusion presence or as perfusion absent in the pancreatic cancer. Using WHO criteria we recorded the tumor response after 3 months on multislice helical CT scans. Treatment effects were evaluated based on the pancreatic cancer, liver metastasis, and factors such as intrahepatic and pancreatic perfusion on fusion images. For statistical analysis we used the chi-square test; survival was evaluated by the Kaplan Meier method (log-rank test). Results. On fusion images, pancreatic and intrahepatic perfusion was recorded as hot spot and as homogeneous distribution, respectively, in 18 patients (55%) and as cold spot and heterogeneous distribution, respectively, in 15 (45%). Patients with hot spot in the pancreatic tumor and homogeneous distribution in the liver manifested better treatment results (p < 0.05 and p < 0.01, respectively). Patients with hot spot both in the pancreatic cancer and in the liver survived longer than those with cold spot in the pancreatic cancer and heterogeneous distribution in the liver (median {+-} SD, 16.0 {+-} 3.7 vs. 8.0 {+-} 1.4 months; p < 0.05). Conclusions. We conclude that in patients with advanced

  16. Detection models for freehand SPECT reconstruction

    NASA Astrophysics Data System (ADS)

    Hartl, Alexander; Shakir, Dzhoshkun I.; Lasser, Tobias; Ziegler, Sibylle I.; Navab, Nassir

    2015-02-01

    Nuclear imaging modalities are commonly used tools in today’s diagnostics and therapy planning. However for interventional use they suffer from drawbacks which limit their application. Freehand SPECT was developed to provide 3D functional imaging during interventions. It combines a nuclear detector with an optical tracking system to obtain its position and orientation in space and synchronizes this with the detector readings. This information can be used to compute a 3D tomographic reconstruction of an activity distribution of a nuclear tracer. As there is no fixed geometry, the system matrix has to be computed on the fly. This is done with models of the detection process for completely arbitrary freehand acquisitions. The accuracy of the reconstructions is highly dependent on the used models of the detection process. Different models of the detection process were developed and evaluated in this work, in particular two analytical models as well as lookup tables generated from either real measurements or Monte Carlo simulations. We showed that it is possible to perform acceptable reconstructions with a simple but efficient analytical model. The use of lookup tables to generate the system matrix in Freehand SPECT is a fast solution with good accuracy.

  17. Detection models for freehand SPECT reconstruction.

    PubMed

    Hartl, Alexander; Shakir, Dzhoshkun I; Lasser, Tobias; Ziegler, Sibylle I; Navab, Nassir

    2015-02-01

    Nuclear imaging modalities are commonly used tools in today's diagnostics and therapy planning. However for interventional use they suffer from drawbacks which limit their application. Freehand SPECT was developed to provide 3D functional imaging during interventions. It combines a nuclear detector with an optical tracking system to obtain its position and orientation in space and synchronizes this with the detector readings. This information can be used to compute a 3D tomographic reconstruction of an activity distribution of a nuclear tracer. As there is no fixed geometry, the system matrix has to be computed on the fly. This is done with models of the detection process for completely arbitrary freehand acquisitions. The accuracy of the reconstructions is highly dependent on the used models of the detection process. Different models of the detection process were developed and evaluated in this work, in particular two analytical models as well as lookup tables generated from either real measurements or Monte Carlo simulations. We showed that it is possible to perform acceptable reconstructions with a simple but efficient analytical model. The use of lookup tables to generate the system matrix in Freehand SPECT is a fast solution with good accuracy. PMID:25585618

  18. Collimator design for a multipinhole brain SPECT insert for MRI

    SciTech Connect

    Van Audenhaege, Karen; Van Holen, Roel; Vanhove, Christian; Vandenberghe, Stefaan

    2015-11-15

    Purpose: Brain single photon emission computed tomography (SPECT) imaging is an important clinical tool, with unique tracers for studying neurological diseases. Nowadays, most commercial SPECT systems are combined with x-ray computed tomography (CT) in so-called SPECT/CT systems to obtain an anatomical background for the functional information. However, while CT images have a high spatial resolution, they have a low soft-tissue contrast, which is an important disadvantage for brain imaging. Magnetic resonance imaging (MRI), on the other hand, has a very high soft-tissue contrast and does not involve extra ionizing radiation. Therefore, the authors designed a brain SPECT insert that can operate inside a clinical MRI. Methods: The authors designed and simulated a compact stationary multipinhole SPECT insert based on digital silicon photomultiplier detector modules, which have shown to be MR-compatible and have an excellent intrinsic resolution (0.5 mm) when combined with a monolithic 2 mm thick LYSO crystal. First, the authors optimized the different parameters of the SPECT system to maximize sensitivity for a given target resolution of 7.2 mm in the center of the field-of-view, given the spatial constraints of the MR system. Second, the authors performed noiseless simulations of two multipinhole configurations to evaluate sampling and reconstructed resolution. Finally, the authors performed Monte Carlo simulations and compared the SPECT insert with a clinical system with ultrahigh-resolution (UHR) fan beam collimators, based on contrast-to-noise ratio and a visual comparison of a Hoffman phantom with a 9 mm cold lesion. Results: The optimization resulted in a stationary multipinhole system with a collimator radius of 150.2 mm and a detector radius of 172.67 mm, which corresponds to four rings of 34 diSPM detector modules. This allows the authors to include eight rings of 24 pinholes, which results in a system volume sensitivity of 395 cps/MBq. Noiseless simulations

  19. A resistive heating system for homeothermic maintenance in small animals

    PubMed Central

    Kersemans, Veerle; Gilchrist, Stuart; Allen, Philip D.; Beech, John S.; Kinchesh, Paul; Vojnovic, Borivoj; Smart, Sean C.

    2015-01-01

    Purpose To develop an MR-compatible resistive heater for temperature maintenance of anaesthetized animals. Materials and Methods An MR-compatible resistive electrical heater was formed from a tightly-wound twisted pair wire, interfaced to a homeothermic maintenance controller. Fat-suppressed images and localized spectra were acquired with the twisted pair heater and a near-identical single strand heater during operation at maximum power. Data were also acquired in the absence of heating to demonstrate the insensitivity of MR to distortions arising from the passage of current through the heater elements. The efficacy of temperature maintenance was examined by measuring rectal temperature immediately following induction of general anesthesia and throughout and after the acquisition of a heater artifact-prone image series. Results Images and spectra acquired in the presence and absence of DC current through the twisted pair heater were identical whereas the passage of current through the single strand wire created field shifts and lineshape distortions. Temperature that is lost during anesthesia induction was recovered within approximately 10–20 minutes of induction, and a stable temperature is reached as the animal's temperature approaches the set target. Conclusion The twisted pair wire heater does not interfere with MR image quality and maintains adequate thermal input to the animal to maintain body temperature. PMID:25863135

  20. Application of SPECT/CT imaging system and radiochemical analysis for investigation of blood kinetics and tissue distribution of radiolabeled plumbagin in healthy and Plasmodium berghei-infected mice.

    PubMed

    Sumsakul, W; Karbwang, J; Na-Bangchang, K

    2016-02-01

    Plumbagin is a derivative of napthoquinone which is isolated from the roots of plants in several families. These compound exhibits a wide range of biological and pharmacological activities including antimalarial, antibacterial, antifungal, and anticancer activities. The aim of the study was to investigate blood kinetics and tissue distribution of plumbagin in healthy and Plasmodium berghei-infected mice using Single-Photon Emission Computed Tomography/Computed Tomography (SPECT/CT) and radiochemical analysis by gamma counter. Plumbagin was labeled with (99m)technetium and the reducing agent stannous chloride dihydrate (50 μg/ml) at pH 6.5. Blood kinetics and tissue distribution of the radiolabeled plumbagin were investigated in healthy and P. berghei-infected mice (2 males and 2 females for each experimental group). In vitro and in vivo stability of plumbagin complex suggested satisfactory stability profiles of (99m)Tc-plumbagin complex in plasma and normal saline (92.21-95.47%) within 24 h. Significant difference in blood kinetics parameters (Cmax, AUC, t1/2, MRT, Vd, and CL) were observed between P. berghei-infected and healthy mice. The labeled complex distributed to all organs of both healthy and infected mice but with high intensity in liver, followed by lung, stomach, large intestine and kidney. Accumulation in spleen was markedly noticeable in the infected mice. Plumbagin-labeled complex was rapidly cleared from blood and major routes of excretion were hepatobiliary and pulmonary routes. In P. berghei-infected mice, t1/2 was significantly decreased, while Vd and CL were increased compared with healthy mice. Result suggests that malaria disease state influenced the pharmacokinetics and disposition of plumbagin. SPECT/CT imaging with radiolabeled (99m)Tc is a viable non-invasive technique that can be applied for investigation of kinetics and biodistribution of plumbagin in animal models. PMID:26713669

  1. Understanding Mechanical Systems Through Computer Animation and Kinematic Imagery. Final Report.

    ERIC Educational Resources Information Center

    Carpenter, Patricia A.; Just, Marcel Adam

    One purpose of this research is to develop models of cognitive processes in understanding mechanical systems. A particular focus was on the processes in mentally animating the representation of a mechanical system, and the contribution of animation graphics in comprehension. Several studies, involving eye fixations, verbal protocols, and process…

  2. 40 CFR 792.90 - Animal and other test system care.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 32 2011-07-01 2011-07-01 false Animal and other test system care. 792.90 Section 792.90 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT (CONTINUED) GOOD LABORATORY PRACTICE STANDARDS Testing Facilities Operation § 792.90 Animal and other test system care. (a)...

  3. 40 CFR 792.90 - Animal and other test system care.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 32 2014-07-01 2014-07-01 false Animal and other test system care. 792... SUBSTANCES CONTROL ACT (CONTINUED) GOOD LABORATORY PRACTICE STANDARDS Testing Facilities Operation § 792.90 Animal and other test system care. (a) There shall be standard operating procedures for the...

  4. 40 CFR 792.90 - Animal and other test system care.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 33 2013-07-01 2013-07-01 false Animal and other test system care. 792... SUBSTANCES CONTROL ACT (CONTINUED) GOOD LABORATORY PRACTICE STANDARDS Testing Facilities Operation § 792.90 Animal and other test system care. (a) There shall be standard operating procedures for the...

  5. 40 CFR 160.90 - Animal and other test system care.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Animal and other test system care. 160.90 Section 160.90 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS GOOD LABORATORY PRACTICE STANDARDS Testing Facilities Operation § 160.90 Animal and other test system care. (a) There shall be...

  6. 40 CFR 160.90 - Animal and other test system care.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 25 2012-07-01 2012-07-01 false Animal and other test system care. 160.90 Section 160.90 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS GOOD LABORATORY PRACTICE STANDARDS Testing Facilities Operation § 160.90 Animal and other test system care. (a) There shall be...

  7. 40 CFR 160.90 - Animal and other test system care.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Animal and other test system care. 160.90 Section 160.90 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS GOOD LABORATORY PRACTICE STANDARDS Testing Facilities Operation § 160.90 Animal and other test system care. (a) There shall be...

  8. 40 CFR 792.90 - Animal and other test system care.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 33 2012-07-01 2012-07-01 false Animal and other test system care. 792.90 Section 792.90 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT (CONTINUED) GOOD LABORATORY PRACTICE STANDARDS Testing Facilities Operation § 792.90 Animal and other test system care. (a)...

  9. 40 CFR 792.90 - Animal and other test system care.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 31 2010-07-01 2010-07-01 true Animal and other test system care. 792.90 Section 792.90 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT (CONTINUED) GOOD LABORATORY PRACTICE STANDARDS Testing Facilities Operation § 792.90 Animal and other test system care. (a)...

  10. Monte Carlo simulation of PET and SPECT imaging of {sup 90}Y

    SciTech Connect

    Takahashi, Akihiko Sasaki, Masayuki; Himuro, Kazuhiko; Yamashita, Yasuo; Komiya, Isao; Baba, Shingo

    2015-04-15

    Purpose: Yittrium-90 ({sup 90}Y) is traditionally thought of as a pure beta emitter, and is used in targeted radionuclide therapy, with imaging performed using bremsstrahlung single-photon emission computed tomography (SPECT). However, because {sup 90}Y also emits positrons through internal pair production with a very small branching ratio, positron emission tomography (PET) imaging is also available. Because of the insufficient image quality of {sup 90}Y bremsstrahlung SPECT, PET imaging has been suggested as an alternative. In this paper, the authors present the Monte Carlo-based simulation–reconstruction framework for {sup 90}Y to comprehensively analyze the PET and SPECT imaging techniques and to quantitatively consider the disadvantages associated with them. Methods: Our PET and SPECT simulation modules were developed using Monte Carlo simulation of Electrons and Photons (MCEP), developed by Dr. S. Uehara. PET code (MCEP-PET) generates a sinogram, and reconstructs the tomography image using a time-of-flight ordered subset expectation maximization (TOF-OSEM) algorithm with attenuation compensation. To evaluate MCEP-PET, simulated results of {sup 18}F PET imaging were compared with the experimental results. The results confirmed that MCEP-PET can simulate the experimental results very well. The SPECT code (MCEP-SPECT) models the collimator and NaI detector system, and generates the projection images and projection data. To save the computational time, the authors adopt the prerecorded {sup 90}Y bremsstrahlung photon data calculated by MCEP. The projection data are also reconstructed using the OSEM algorithm. The authors simulated PET and SPECT images of a water phantom containing six hot spheres filled with different concentrations of {sup 90}Y without background activity. The amount of activity was 163 MBq, with an acquisition time of 40 min. Results: The simulated {sup 90}Y-PET image accurately simulated the experimental results. PET image is visually

  11. Filtering in SPECT Image Reconstruction

    PubMed Central

    Lyra, Maria; Ploussi, Agapi

    2011-01-01

    Single photon emission computed tomography (SPECT) imaging is widely implemented in nuclear medicine as its clinical role in the diagnosis and management of several diseases is, many times, very helpful (e.g., myocardium perfusion imaging). The quality of SPECT images are degraded by several factors such as noise because of the limited number of counts, attenuation, or scatter of photons. Image filtering is necessary to compensate these effects and, therefore, to improve image quality. The goal of filtering in tomographic images is to suppress statistical noise and simultaneously to preserve spatial resolution and contrast. The aim of this work is to describe the most widely used filters in SPECT applications and how these affect the image quality. The choice of the filter type, the cut-off frequency and the order is a major problem in clinical routine. In many clinical cases, information for specific parameters is not provided, and findings cannot be extrapolated to other similar SPECT imaging applications. A literature review for the determination of the mostly used filters in cardiac, brain, bone, liver, kidneys, and thyroid applications is also presented. As resulting from the overview, no filter is perfect, and the selection of the proper filters, most of the times, is done empirically. The standardization of image-processing results may limit the filter types for each SPECT examination to certain few filters and some of their parameters. Standardization, also, helps in reducing image processing time, as the filters and their parameters must be standardised before being put to clinical use. Commercial reconstruction software selections lead to comparable results interdepartmentally. The manufacturers normally supply default filters/parameters, but these may not be relevant in various clinical situations. After proper standardisation, it is possible to use many suitable filters or one optimal filter. PMID:21760768

  12. Advances in SPECT and PET Hardware.

    PubMed

    Slomka, Piotr J; Pan, Tinsu; Berman, Daniel S; Germano, Guido

    2015-01-01

    There have been significant recent advances in single photon emission computed tomography (SPECT) and positron emission tomography (PET) hardware. Novel collimator designs, such as multi-pinhole and locally focusing collimators arranged in geometries that are optimized for cardiac imaging have been implemented to reduce imaging time and radiation dose. These new collimators have been coupled with solid state photon detectors to further improve image quality and reduce scanner size. The new SPECT scanners demonstrate up to a 7-fold increase in photon sensitivity and up to 2 times improvement in image resolution. Although PET scanners are used primarily for oncological imaging, cardiac imaging can benefit from the improved PET sensitivity of 3D systems without inter-plane septa and implementation of the time-of-flight reconstruction. Additionally, resolution recovery techniques are now implemented by all major PET vendors. These new methods improve image contrast, image resolution, and reduce image noise. Simultaneous PET/magnetic resonance (MR) hybrid systems have been developed. Solid state detectors with avalanche photodiodes or digital silicon photomultipliers have also been utilized in PET. These new detectors allow improved image resolution, higher count rate, as well as a reduced sensitivity to electromagnetic MR fields. PMID:25721706

  13. SPECT attenuation correction: an essential tool to realize nuclear cardiology's manifest destiny.

    PubMed

    Garcia, Ernest V

    2007-01-01

    Single photon emission computed tomography (SPECT) myocardial perfusion imaging has attained widespread clinical acceptance as a standard of care for cardiac patients. Yet, physical phenomena degrade the accuracy of how our cardiac images are visually interpreted or quantitatively analyzed. This degradation results in cardiac images in which brightness or counts are not necessarily linear with tracer uptake or myocardial perfusion. Attenuation correction (AC) is a methodology that has evolved over the last 30 years to compensate for this degradation. Numerous AC clinical trials over the last 10 years have shown increased diagnostic accuracy over non-AC SPECT for detecting and localizing coronary artery disease, particularly for significantly increasing specificity and normalcy rate. This overwhelming evidence has prompted our professional societies to issue a joint position statement in 2004 recommending the use of AC to maximize SPECT diagnostic accuracy and clinical usefulness. Phantom and animal studies have convincingly shown how SPECT AC recovers the true regional myocardial activity concentration, while non-AC SPECT does not. Thus, AC is also an essential tool for extracting quantitative parameters from all types of cardiac radionuclide distributions, and plays an important role in establishing cardiac SPECT for flow, metabolic, innervation, and molecular imaging, our manifest destiny. PMID:17276302

  14. Scatter and crosstalk corrections for {sup 99m}Tc/{sup 123}I dual-radionuclide imaging using a CZT SPECT system with pinhole collimators

    SciTech Connect

    Fan, Peng; Hutton, Brian F.; Holstensson, Maria; Ljungberg, Michael; Hendrik Pretorius, P.; Prasad, Rameshwar; Liu, Chi; Ma, Tianyu; Liu, Yaqiang; Wang, Shi; Thorn, Stephanie L.; Stacy, Mitchel R.; Sinusas, Albert J.

    2015-12-15

    Purpose: The energy spectrum for a cadmium zinc telluride (CZT) detector has a low energy tail due to incomplete charge collection and intercrystal scattering. Due to these solid-state detector effects, scatter would be overestimated if the conventional triple-energy window (TEW) method is used for scatter and crosstalk corrections in CZT-based imaging systems. The objective of this work is to develop a scatter and crosstalk correction method for {sup 99m}Tc/{sup 123}I dual-radionuclide imaging for a CZT-based dedicated cardiac SPECT system with pinhole collimators (GE Discovery NM 530c/570c). Methods: A tailing model was developed to account for the low energy tail effects of the CZT detector. The parameters of the model were obtained using {sup 99m}Tc and {sup 123}I point source measurements. A scatter model was defined to characterize the relationship between down-scatter and self-scatter projections. The parameters for this model were obtained from Monte Carlo simulation using SIMIND. The tailing and scatter models were further incorporated into a projection count model, and the primary and self-scatter projections of each radionuclide were determined with a maximum likelihood expectation maximization (MLEM) iterative estimation approach. The extracted scatter and crosstalk projections were then incorporated into MLEM image reconstruction as an additive term in forward projection to obtain scatter- and crosstalk-corrected images. The proposed method was validated using Monte Carlo simulation, line source experiment, anthropomorphic torso phantom studies, and patient studies. The performance of the proposed method was also compared to that obtained with the conventional TEW method. Results: Monte Carlo simulations and line source experiment demonstrated that the TEW method overestimated scatter while their proposed method provided more accurate scatter estimation by considering the low energy tail effect. In the phantom study, improved defect contrasts were

  15. Design and performance of a small-animal imaging system using synthetic collimation

    PubMed Central

    Havelin, R J; Miller, B W; Barrett, H H; Furenlid, L R; Murphy, J M; Foley, M J

    2015-01-01

    This work outlines the design and construction of a single-photon emission computed tomography (SPECT) imaging system based on the concept of synthetic collimation. A focused multi-pinhole collimator is constructed using rapid-prototyping and casting techniques. The collimator projects the centre of the field of view (FOV) through forty-six pinholes when the detector is adjacent to the collimator, with the number reducing towards the edge of the FOV. The detector is then moved further from the collimator to increase the magnification of the system. The object distance remains constant, and each new detector distance is a new system configuration. The level of overlap of the pinhole projections increases as the system magnification increases, but the number of projections subtended by the detector is reduced. There is no rotation in the system; a single tomographic angle is used in each system configuration. Image reconstruction is performed using maximum-likelihood expectation-maximization (MLEM), and an experimentally measured system matrix. The system matrix is measured for each configuration on a coarse grid, using a point source. The pinholes are individually identified and tracked, and a Gaussian fit is made to each projection. The coefficients of these fits are used to interpolate the system matrix. The system is validated experimentally with a hot-rod phantom. The Fourier crosstalk matrix is also measured to provide an estimate of the average spatial resolution along each axis over the entire FOV. The 3D synthetic-collimator image is formed by estimating the activity distribution within the FOV, and summing the activities in the voxels along the axis perpendicular to the collimator face. PMID:23618819

  16. Nonlinear dual reconstruction of SPECT activity and attenuation images.

    PubMed

    Liu, Huafeng; Guo, Min; Hu, Zhenghui; Shi, Pengcheng; Hu, Hongjie

    2014-01-01

    In single photon emission computed tomography (SPECT), accurate attenuation maps are needed to perform essential attenuation compensation for high quality radioactivity estimation. Formulating the SPECT activity and attenuation reconstruction tasks as coupled signal estimation and system parameter identification problems, where the activity distribution and the attenuation parameter are treated as random variables with known prior statistics, we present a nonlinear dual reconstruction scheme based on the unscented Kalman filtering (UKF) principles. In this effort, the dynamic changes of the organ radioactivity distribution are described through state space evolution equations, while the photon-counting SPECT projection data are measured through the observation equations. Activity distribution is then estimated with sub-optimal fixed attenuation parameters, followed by attenuation map reconstruction given these activity estimates. Such coupled estimation processes are iteratively repeated as necessary until convergence. The results obtained from Monte Carlo simulated data, physical phantom, and real SPECT scans demonstrate the improved performance of the proposed method both from visual inspection of the images and a quantitative evaluation, compared to the widely used EM-ML algorithms. The dual estimation framework has the potential to be useful for estimating the attenuation map from emission data only and thus benefit the radioactivity reconstruction. PMID:25225796

  17. Nonlinear Dual Reconstruction of SPECT Activity and Attenuation Images

    PubMed Central

    Liu, Huafeng; Guo, Min; Hu, Zhenghui; Shi, Pengcheng; Hu, Hongjie

    2014-01-01

    In single photon emission computed tomography (SPECT), accurate attenuation maps are needed to perform essential attenuation compensation for high quality radioactivity estimation. Formulating the SPECT activity and attenuation reconstruction tasks as coupled signal estimation and system parameter identification problems, where the activity distribution and the attenuation parameter are treated as random variables with known prior statistics, we present a nonlinear dual reconstruction scheme based on the unscented Kalman filtering (UKF) principles. In this effort, the dynamic changes of the organ radioactivity distribution are described through state space evolution equations, while the photon-counting SPECT projection data are measured through the observation equations. Activity distribution is then estimated with sub-optimal fixed attenuation parameters, followed by attenuation map reconstruction given these activity estimates. Such coupled estimation processes are iteratively repeated as necessary until convergence. The results obtained from Monte Carlo simulated data, physical phantom, and real SPECT scans demonstrate the improved performance of the proposed method both from visual inspection of the images and a quantitative evaluation, compared to the widely used EM-ML algorithms. The dual estimation framework has the potential to be useful for estimating the attenuation map from emission data only and thus benefit the radioactivity reconstruction. PMID:25225796

  18. MOAB: a spatially explicit, individual-based expert system for creating animal foraging models

    USGS Publications Warehouse

    Carter, J.; Finn, John T.

    1999-01-01

    We describe the development, structure, and corroboration process of a simulation model of animal behavior (MOAB). MOAB can create spatially explicit, individual-based animal foraging models. Users can create or replicate heterogeneous landscape patterns, and place resources and individual animals of a goven species on that landscape to simultaneously simulate the foraging behavior of multiple species. The heuristic rules for animal behavior are maintained in a user-modifiable expert system. MOAB can be used to explore hypotheses concerning the influence of landscape patttern on animal movement and foraging behavior. A red fox (Vulpes vulpes L.) foraging and nest predation model was created to test MOAB's capabilities. Foxes were simulated for 30-day periods using both expert system and random movement rules. Home range size, territory formation and other available simulation studies. A striped skunk (Mephitis mephitis L.) model also was developed. The expert system model proved superior to stochastic in respect to territory formation, general movement patterns and home range size.

  19. Evaluation of a Wobbling Method Applied to Correcting Defective Pixels of CZT Detectors in SPECT Imaging.

    PubMed

    Xie, Zhaoheng; Li, Suying; Yang, Kun; Xu, Baixuan; Ren, Qiushi

    2016-01-01

    In this paper, we propose a wobbling method to correct bad pixels in cadmium zinc telluride (CZT) detectors, using information of related images. We build up an automated device that realizes the wobbling correction for small animal Single Photon Emission Computed Tomography (SPECT) imaging. The wobbling correction method is applied to various constellations of defective pixels. The corrected images are compared with the results of conventional interpolation method, and the correction effectiveness is evaluated quantitatively using the factor of peak signal-to-noise ratio (PSNR) and structural similarity (SSIM). In summary, the proposed wobbling method, equipped with the automatic mechanical system, provides a better image quality for correcting defective pixels, which could be used for all pixelated detectors for molecular imaging. PMID:27240368

  20. Evaluation of a Wobbling Method Applied to Correcting Defective Pixels of CZT Detectors in SPECT Imaging

    PubMed Central

    Xie, Zhaoheng; Li, Suying; Yang, Kun; Xu, Baixuan; Ren, Qiushi

    2016-01-01

    In this paper, we propose a wobbling method to correct bad pixels in cadmium zinc telluride (CZT) detectors, using information of related images. We build up an automated device that realizes the wobbling correction for small animal Single Photon Emission Computed Tomography (SPECT) imaging. The wobbling correction method is applied to various constellations of defective pixels. The corrected images are compared with the results of conventional interpolation method, and the correction effectiveness is evaluated quantitatively using the factor of peak signal-to-noise ratio (PSNR) and structural similarity (SSIM). In summary, the proposed wobbling method, equipped with the automatic mechanical system, provides a better image quality for correcting defective pixels, which could be used for all pixelated detectors for molecular imaging. PMID:27240368

  1. LOTUS 1-2-3-BASED SYSTEM FOR RECORDING AND MAINTAINING BODY WEIGHT OF LABORATORY ANIMALS

    EPA Science Inventory

    Body weight maintenance is required in a variety of behavioral and physiological studies. C-based animal weighing system is described which features automated data collection and allows for accurate control of body weight in test animals via manipulation of food intake. ajor syst...

  2. Systems Biology in Animal Breeding: Identifying relationships among markers, genes, and phenotypes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Breeding and Genetics Symposium titled “Systems Biology in Animal Breeding: Identifying relationships among markers, genes, and phenotypes” was held at the Joint Annual Meeting of the American Dairy Science Association and the American Society of Animal Science in Phoenix, AZ, July 15 to 19, 201...

  3. An investigation of inconsistent projections and artefacts in multi-pinhole SPECT with axially aligned pinholes

    NASA Astrophysics Data System (ADS)

    Kench, P. L.; Lin, J.; Gregoire, M. C.; Meikle, S. R.

    2011-12-01

    Multiple pinholes are advantageous for maximizing the use of the available field of view (FOV) of compact small animal single photon emission computed tomography (SPECT) detectors. However, when the pinholes are aligned axially to optimize imaging of extended objects, such as rodents, multiplexing of the pinhole projections can give rise to inconsistent data which leads to 'ghost point' artefacts in the reconstructed volume. A novel four pinhole collimator with a baffle was designed and implemented to eliminate these inconsistent projections. Simulation and physical phantom studies were performed to investigate artefacts from axially aligned pinholes and the efficacy of the baffle in removing inconsistent data and, thus, reducing reconstruction artefacts. SPECT was performed using a Defrise phantom to investigate the impact of collimator design on FOV utilization and axial blurring effects. Multiple pinhole SPECT acquired with a baffle had fewer artefacts and improved quantitative accuracy when compared to SPECT acquired without a baffle. The use of four pinholes positioned in a square maximized the available FOV, increased acquisition sensitivity and reduced axial blurring effects. These findings support the use of a baffle to eliminate inconsistent projection data arising from axially aligned pinholes and improve small animal SPECT reconstructions.

  4. System identification of perilymphatic fistula in an animal model

    NASA Technical Reports Server (NTRS)

    Wall, C. 3rd; Casselbrant, M. L.

    1992-01-01

    An acute animal model has been developed in the chinchilla for the study of perilymphatic fistulas. Micropunctures were made in three sites to simulate bony, round window, and oval window fistulas. The eye movements in response to pressure applied to the external auditory canal were recorded after micropuncture induction and in preoperative controls. The main pressure stimulus was a pseudorandom binary sequence (PRBS) that rapidly changed between plus and minus 200 mm of water. The PRBS stimulus, with its wide frequency bandwidth, produced responses clearly above the preoperative baseline in 78 percent of the runs. The response was better between 0.5 and 3.3 Hz than it was below 0.5 Hz. The direction of horizontal eye movement was toward the side of the fistula with positive pressure applied in 92 percent of the runs. Vertical eye movements were also observed. The ratio of vertical eye displacement to horizontal eye displacement depended upon the site of the micropuncture induction. Thus, such a ratio measurement may be clinically useful in the noninvasive localization of perilymphatic fistulas in humans.

  5. WAHIS-Wild and its interface: the OIE worldwide monitoring system for wild animal diseases.

    PubMed

    Jebara, Karim Ben

    2016-06-30

    Wild animal diseases are a global growing concern, given the threat that they pose to animal health and their zoonotic potential. The World Organisation for Animal Health (OIE) was among the first organisations to recognise the importance of having a comprehensive knowledge of the disease situation in wild animals, collecting information on wildlife diseases worldwide since 1993, when for the first time an annual questionnaire was distribute by OIE to members Countries in order to collect qualitative and quantitative data on selected diseases in wild animals. Starting with 2008 until 2012 an updated version of questionnaire was circulated to allow for identifying wildlife species by their Latin name and by their common names in the 3 OIE official languages (English, French, and Spanish). This specific functionality was then implemented in the World Animal Health Information System (WAHIS) in 2012, when this information was made available to the public through WAHIS-Wild Interface. PMID:27393871

  6. Animal models for the study of the effects of spaceflight on the immune system

    NASA Astrophysics Data System (ADS)

    Sonnenfeld, G.

    2003-10-01

    Animal models have been used to determine the effects of spaceflight on the immune system. Rats and rhesus monkeys have been the primary animals used for actual space flight studies, but mice have also been utilized for studies in ground-based models. The primary ground based model used has been hindlimb unloading of rodents, which is similar to the chronic bed-rest model for humans. A variety of immune responses have been shown to be modified when animals are hindlimb unloaded. These results parallel those observed when animals are flown in space. In general, immune responses are depressed in animals maintained in the hindlimb unloading model or flown in space. These results raise the possibility that spaceflight could result in decreased resistance to infection in animals.

  7. Biomedical Imaging: SPECT and PET

    SciTech Connect

    Lecomte, Roger

    2007-11-26

    Single Photon Emission Computed Tomography (SPECT) and Positron Emission Tomography (PET) are non-invasive nuclear imaging techniques relying on the use of tomographic reconstruction methods to provide 3D representations of the distribution of radiolabeled molecules in vivo. Differences in the underlying physical principles determine the achievable spatial resolution, sensitivity, specificity and observation time span of these two imaging modalities. Their specific characteristics are described and the current technology developments and design tradeoffs are reviewed.

  8. Towed Twin-Fuselage Glider Launch System (CGI Animation)

    NASA Video Gallery

    The towed glider is an element of the novel rocket-launching concept of the Towed Glider Air-Launch System (TGALS). The TGALS demonstration’s goal is to provide proof-of-concept of a towed, airborn...

  9. Telocytes in female reproductive system (human and animal).

    PubMed

    Aleksandrovych, Veronika; Walocha, Jerzy A; Gil, Krzysztof

    2016-06-01

    Telocytes (TCs) are a newly discovered type of cell with numerous functions. They have been found in a large variety of organs: heart (endo-, myo-, epi- and pericardium, myocardial sleeves, heart valves); digestive tract and annex glands (oesophagus, stomach, duodenum, jejunum, liver, gallbladder, salivary gland, exocrine pancreas); respiratory system (trachea and lungs); urinary system (kidney, renal pelvis, ureters, bladder, urethra); female reproductive system (uterus, Fallopian tube, placenta, mammary gland); vasculature (blood vessels, thoracic duct); serous membranes (mesentery and pleura); and other organs (skeletal muscle, meninges and choroid plexus, neuromuscular spindles, fascia lata, skin, eye, prostate, bone marrow). Likewise, TCs are widely distributed in vertebrates (fish, reptiles, birds, mammals, including human). This review summarizes particular features of TCs in the female reproductive system, emphasizing their involvement in physiological and pathophysiological processes. PMID:27060783

  10. Report of the FELASA Working Group on evaluation of quality systems for animal units.

    PubMed

    Howard, B; van Herck, H; Guillen, J; Bacon, B; Joffe, R; Ritskes-Hoitinga, M

    2004-04-01

    This report compares and considers the merits of existing, internationally available quality management systems suitable for implementation in experimental animal facilities. These are: the Good Laboratory Practice Guidelines, ISO 9000:2000 (International Organization for Standardization) and AAALAC International (Association for Assessment and Accreditation of Laboratory Animal Care International). Good laboratory practice (GLP) is a legal requirement for institutions undertaking non-clinical health and environmental studies for the purpose of registering or licensing for use and which have to be 'GLP-compliant'. GLP guidelines are often only relevant for and obtainable by those institutions. ISO is primarily an external business standard, which provides a management tool to master and optimize a business activity; it aims to implement and enhance 'customer satisfaction'. AAALAC is primarily a peer-reviewed system of accreditation which evaluates the organization and procedures in programmes of animal care and use to ensure the appropriate use of animals, safeguard animal well-being (ensuring state-of-the-art housing, management, procedural techniques, etc.) as well as the management of health and safety of staff. Management needs to determine, on the basis of a facility's specific goals, whether benefits would arise from the introduction of a quality system and, if so, which system is most appropriate. The successful introduction of a quality system confers peer-recognition against an independent standard, thereby providing assurance of standards of animal care and use, improving the quality of animal studies, and contributing to the three Rs-reduction, refinement and replacement. PMID:15070450

  11. Production costs and animal welfare for four stylized hog production systems.

    PubMed

    Seibert, Lacey; Norwood, F Bailey

    2011-01-01

    Nonhuman animal welfare is arguably the most contentious issue facing the hog industry. Animal advocacy groups influence the regulation of hog farms and induce some consumers to demand more humane pork products. Hog producers are understandably reluctant to improve animal well being unless the premium they extract exceeds the corresponding increase in cost. To better understand the relationship between animal welfare and production costs under different farm systems, this study investigates 4 stylized hog production systems. The results show that increasing animal welfare for all hogs in the United States will increase retail pork prices by a maximum of 2% for a small welfare increase and 5% for a large welfare increase. The cost of banning gestation crates measured by this study is lower than the consumer willingness-to-pay from other studies. PMID:21191844

  12. Cervical SPECT Camera for Parathyroid Imaging

    SciTech Connect

    None, None

    2012-08-31

    Primary hyperparathyroidism characterized by one or more enlarged parathyroid glands has become one of the most common endocrine diseases in the world affecting about 1 per 1000 in the United States. Standard treatment is highly invasive exploratory neck surgery called Parathyroidectomy. The surgery has a notable mortality rate because of the close proximity to vital structures. The move to minimally invasive parathyroidectomy is hampered by the lack of high resolution pre-surgical imaging techniques that can accurately localize the parathyroid with respect to surrounding structures. We propose to develop a dedicated ultra-high resolution (~ 1 mm) and high sensitivity (10x conventional camera) cervical scintigraphic imaging device. It will be based on a multiple pinhole-camera SPECT system comprising a novel solid state CZT detector that offers the required performance. The overall system will be configured to fit around the neck and comfortably image a patient.

  13. A Roadmap for the Development of Alternative (Non-Animal) Methods for Systemic Toxicity Testing

    EPA Science Inventory

    Systemic toxicity testing forms the cornerstone for the safety evaluation of substances. Pressures to move from traditional animal models to novel technologies arise from various concerns, including: the need to evaluate large numbers of previously untested chemicals and new prod...

  14. Proceedings of the cardiac PET summit meeting 12 may 2014: Cardiac PET and SPECT instrumentation.

    PubMed

    Garcia, Ernest V

    2015-06-01

    Advances in PET and SPECT and imaging hardware and software are vastly improving the noninvasive evaluation of myocardial perfusion and function. PET perfusion imaging has benefitted from the introduction of novel detectors that now allow true 3D imaging, and precise attenuation correction (AC). These developments have also resulted in perfusion images with higher spatial and contrast resolution that may be acquired in shorter protocols and/or with less patient radiation exposure than traditional PET or SPECT studies. Hybrid PET/CT cameras utilize transmission computed tomographic (CT) scans for AC, and offer the additional clinical advantages of evaluating coronary calcium and myocardial anatomy but at a higher cost than PET scanners that use (68)Ge radioactive line sources. As cardiac PET systems continue to improve, dedicated cardiac SPECT systems are also undergoing a profound change in their design. The scintillation camera general purpose design is being replaced with systems with multiple detectors focused on the heart yielding 5 to 10 times the sensitivity of conventional SPECT. As a result, shorter acquisition times and/or lower tracer doses produce higher quality SPECT images than were possible before. This article reviews these concepts and compares the attributes of PET and SPECT instrumentation. PMID:25824018

  15. ANIMATION AND VISUALIZATION OF WATER QUALITY IN DISTRIBUTION SYSTEMS

    EPA Science Inventory

    Water may undergo a number of changes in the distribution system, making the quality of the water at the customer's tap different from the quality of the water that leaves the treatment plant. Such changes in quality may be caused by chemical or biological variations or by a loss...

  16. New systems for treatment of manure from confined animal production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    New swine waste management systems developed in North Carolina to replace the anaerobic lagoons need to meet the strict performance standards of an environmentally superior technology (EST). These technologies must be able to substantially remove nutrients, heavy metals, emissions of ammonia, odors,...

  17. A reference system for animal biometrics: application to the northern leopard frog

    USGS Publications Warehouse

    Petrovska-Delacretaz, D.; Edwards, A.; Chiasson, J.; Chollet, G.; Pilliod, D.S.

    2014-01-01

    Reference systems and public databases are available for human biometrics, but to our knowledge nothing is available for animal biometrics. This is surprising because animals are not required to give their agreement to be in a database. This paper proposes a reference system and database for the northern leopard frog (Lithobates pipiens). Both are available for reproducible experiments. Results of both open set and closed set experiments are given.

  18. ChR2 transgenic animals in peripheral sensory system: Sensing light as various sensations.

    PubMed

    Ji, Zhi-Gang; Wang, Hongxia

    2016-04-01

    Since the introduction of Channelrhodopsin-2 (ChR2) to neuroscience, optogenetics technology was developed, making it possible to activate specific neurons or circuits with spatial and temporal precision. Various ChR2 transgenic animal models have been generated and are playing important roles in revealing the mechanisms of neural activities, mapping neural circuits, controlling the behaviors of animals as well as exploring new strategy for treating the neurological diseases in both central and peripheral nervous system. An animal including humans senses environments through Aristotle's five senses (sight, hearing, smell, taste and touch). Usually, each sense is associated with a kind of sensory organ (eyes, ears, nose, tongue and skin). Is it possible that one could hear light, smell light, taste light and touch light? When ChR2 is targeted to different peripheral sensory neurons by viral vectors or generating ChR2 transgenic animals, the animals can sense the light as various sensations such as hearing, touch, pain, smell and taste. In this review, we focus on ChR2 transgenic animals in the peripheral nervous system. Firstly the working principle of ChR2 as an optogenetic actuator is simply described. Then the current transgenic animal lines where ChR2 was expressed in peripheral sensory neurons are presented and the findings obtained by these animal models are reviewed. PMID:26903290

  19. [Distribution of the different patterns of aging over the system of animal world].

    PubMed

    Popov, I Iu

    2011-01-01

    Since the system of animal world reflects evolutionary trends, an analysis of distribution of patterns of aging over this system provides information on the causes of the formation of differences among them. In this paper the system of the main animal groups in form of a table is presented, and the distribution of patterns demonstrating minimum and maximum of aging is discussed. Meanwhile the colonial animals are considered as a "minimum of aging", the animals demonstrating drastic self-liquidation after reproduction are considered as a "maximum of aging" (the most well-known example is the pink salmon). It is shown, that as far as the degree of difference from the simplest ancestor increases in process of evolution, the increase of the manifestations of aging takes place. Slow aging of relatively simple organisms cannot be a direct source of measures to prevent aging of complex ones. PMID:21957572

  20. U-SPECT-BioFluo: an integrated radionuclide, bioluminescence, and fluorescence imaging platform

    PubMed Central

    2014-01-01

    Background In vivo bioluminescence, fluorescence, and single-photon emission computed tomography (SPECT) imaging provide complementary information about biological processes. However, to date these signatures are evaluated separately on individual preclinical systems. In this paper, we introduce a fully integrated bioluminescence-fluorescence-SPECT platform. Next to an optimization in logistics and image fusion, this integration can help improve understanding of the optical imaging (OI) results. Methods An OI module was developed for a preclinical SPECT system (U-SPECT, MILabs, Utrecht, the Netherlands). The applicability of the module for bioluminescence and fluorescence imaging was evaluated in both a phantom and in an in vivo setting using mice implanted with a 4 T1-luc + tumor. A combination of a fluorescent dye and radioactive moiety was used to directly relate the optical images of the module to the SPECT findings. Bioluminescence imaging (BLI) was compared to the localization of the fluorescence signal in the tumors. Results Both the phantom and in vivo mouse studies showed that superficial fluorescence signals could be imaged accurately. The SPECT and bioluminescence images could be used to place the fluorescence findings in perspective, e.g. by showing tracer accumulation in non-target organs such as the liver and kidneys (SPECT) and giving a semi-quantitative read-out for tumor spread (bioluminescence). Conclusions We developed a fully integrated multimodal platform that provides complementary registered imaging of bioluminescent, fluorescent, and SPECT signatures in a single scanning session with a single dose of anesthesia. In our view, integration of these modalities helps to improve data interpretation of optical findings in relation to radionuclide images. PMID:25386389

  1. Use of animal models for space flight physiology studies, with special focus on the immune system

    NASA Technical Reports Server (NTRS)

    Sonnenfeld, Gerald

    2005-01-01

    Animal models have been used to study the effects of space flight on physiological systems. The animal models have been used because of the limited availability of human subjects for studies to be carried out in space as well as because of the need to carry out experiments requiring samples and experimental conditions that cannot be performed using humans. Experiments have been carried out in space using a variety of species, and included developmental biology studies. These species included rats, mice, non-human primates, fish, invertebrates, amphibians and insects. The species were chosen because they best fit the experimental conditions required for the experiments. Experiments with animals have also been carried out utilizing ground-based models that simulate some of the effects of exposure to space flight conditions. Most of the animal studies have generated results that parallel the effects of space flight on human physiological systems. Systems studied have included the neurovestibular system, the musculoskeletal system, the immune system, the neurological system, the hematological system, and the cardiovascular system. Hindlimb unloading, a ground-based model of some of the effects of space flight on the immune system, has been used to study the effects of space flight conditions on physiological parameters. For the immune system, exposure to hindlimb unloading has been shown to results in alterations of the immune system similar to those observed after space flight. This has permitted the development of experiments that demonstrated compromised resistance to infection in rodents maintained in the hindlimb unloading model as well as the beginning of studies to develop countermeasures to ameliorate or prevent such occurrences. Although there are limitations to the use of animal models for the effects of space flight on physiological systems, the animal models should prove very valuable in designing countermeasures for exploration class missions of the future.

  2. Systems biology: a new tool for farm animal science.

    PubMed

    Hollung, Kristin; Timperio, Anna M; Olivan, Mamen; Kemp, Caroline; Coto-Montes, Ana; Sierra, Veronica; Zolla, Lello

    2014-03-01

    It is rapidly emerging that the tender meat phenotype is affected by an enormous amount of variables, not only tied to genetics (livestock breeding selection), but also to extrinsic factors, such as feeding conditions, physical activity, rearing environment, administration of hormonal growth promotants, pre-slaughter handling and stress. Proteomics has been widely accepted by meat scientists over the last years and is now commonly used to shed light on the postmortem processes involved in meat tenderization. This review discusses the latest findings with the use of proteomics and systems biology to study the different biochemical pathways postmortem aiming at understanding the concerted action of different molecular mechanisms responsible for meat quality. The conversion of muscle to meat postmortem can be described as a sequence of events involving molecular pathways controlled by a complex interplay of many factors. Among the different pathways emerging are the influence of apoptosis and lately also the role of autophagy in muscle postmortem development. This review thus, focus on how systems-wide integrated investigations (metabolomics, transcriptomics, interactomics, phosphoproteomics, mathematical modeling), which have emerged as complementary tools to proteomics, have helped establishing a few milestones in our understanding of the events leading from muscle to meat conversion. PMID:24555891

  3. A Pilot System for Environmental Monitoring Through Domestic Animals

    NASA Technical Reports Server (NTRS)

    Schwabe, Calvin W.; Sawyer, John; Martin, Wayne

    1971-01-01

    A pilot system for environmental monitoring is in its early phases of development in Northern California. It is based upon the existing nation wide Federal-State Market Cattle Testing (14CT) program for brucellosis in cattle. This latter program depends upon the collection of blood program at the time of identified cattle. As the cattle Population of California is broadly distributed throughout the state, we intend to utilize these blood samples to biologically monitor the distribution and intensity of selected environmental pollutants. In a 2-year preliminary trial, the feasibility of retrieving, utilizing for a purpose similar to this, and tracing back to their geographic areas of origin of MCT samples have been demonstrated.

  4. Systems integrity in health and aging - an animal model approach

    PubMed Central

    2013-01-01

    Human lifespan is positively correlated with childhood intelligence, as measured by psychometric (IQ) tests. The strength of this correlation is similar to the negative effect that smoking has on the life course. This result suggests that people who perform well on psychometric tests in childhood may remain healthier and live longer. The correlation, however, is debated: is it caused exclusively by social-environmental factors or could it also have a biological component? Biological traits of systems integrity that might result in correlations between brain function and lifespan have been suggested but are not well-established, and it is questioned what useful knowledge can come from understanding such mechanisms. In a recent study, we found a positive correlation between brain function and longevity in honey bees. Honey bees are highly social, but relevant social-environmental factors that contribute to cognition-survival correlations in humans are largely absent from insect colonies. Our results, therefore, suggest a biological explanation for the correlation in the bee. Here, we argue that individual differences in stress handling (coping) mechanisms, which both affect the bees’ performance in tests of brain function and their survival could be a trait of systems integrity. Individual differences in coping are much studied in vertebrates, and several species provide attractive models. Here, we discuss how pigs are an interesting model for studying behavioural, physiological and molecular mechanisms that are recruited during stress and that can drive correlations between health, cognition and longevity traits. By revealing biological factors that make individuals susceptible to stress, it might be possible to alleviate health and longevity disparities in people. PMID:24472488

  5. Systems integrity in health and aging - an animal model approach.

    PubMed

    Oostindjer, Marije; Amdam, Gro V

    2013-01-01

    Human lifespan is positively correlated with childhood intelligence, as measured by psychometric (IQ) tests. The strength of this correlation is similar to the negative effect that smoking has on the life course. This result suggests that people who perform well on psychometric tests in childhood may remain healthier and live longer. The correlation, however, is debated: is it caused exclusively by social-environmental factors or could it also have a biological component? Biological traits of systems integrity that might result in correlations between brain function and lifespan have been suggested but are not well-established, and it is questioned what useful knowledge can come from understanding such mechanisms. In a recent study, we found a positive correlation between brain function and longevity in honey bees. Honey bees are highly social, but relevant social-environmental factors that contribute to cognition-survival correlations in humans are largely absent from insect colonies. Our results, therefore, suggest a biological explanation for the correlation in the bee. Here, we argue that individual differences in stress handling (coping) mechanisms, which both affect the bees' performance in tests of brain function and their survival could be a trait of systems integrity. Individual differences in coping are much studied in vertebrates, and several species provide attractive models. Here, we discuss how pigs are an interesting model for studying behavioural, physiological and molecular mechanisms that are recruited during stress and that can drive correlations between health, cognition and longevity traits. By revealing biological factors that make individuals susceptible to stress, it might be possible to alleviate health and longevity disparities in people. PMID:24472488

  6. [The need for research to support the emergence of alternative animal health systems].

    PubMed

    Domenech, J; Bonnet, P; Renard, J F

    2004-04-01

    Animal diseases remain one of the main problems for livestock production in terms of trade development, poverty reduction and public health. Animal health systems are complex because of the diversity of the parties involved and because of various changes in the delivery of veterinary services, such as the redefinition of the roles of the public and private sectors. It is, therefore, often difficult to assess the global performance of animal health systems and sub-systems in terms of their medical, economic and social effectiveness. In addition, the necessary reliability of the health information obtained leads to certification of the status of regions and countries with regard to epizootics, which requires a high degree of standardisation and conformity with international norms. An assessment therefore needs to be made of the advantages of alternative systems compared with conventional systems. An animal health system should be seen as a whole, and when assessing its overall performance several things must be taken into account, e.g. the markets for products and the sometimes contradictory interests of all the different parties involved. There are, therefore, many research needs and avenues to be pursued, including: the methods, data and tools required for assessing the effectiveness of systems, including a definition of what constitutes a reliable indicator; the factors that determine the health of a herd; having a clearer idea of what will affect herd health will make it possible to map risk indicators and animal health care needs; the design and management of realistic and harmonised animal health information systems whose indicators provide reliable measurements of health; the function, organisation and effectiveness of participative surveillance approaches; the definition and effectiveness of animal health contracts, such as health mandates between the State and private veterinarians; the function and role of livestock auxiliaries; the establishment of

  7. The oxytocin system in drug discovery for autism: Animal models and novel therapeutic strategies

    PubMed Central

    Modi, Meera E.; Young, Larry J.

    2012-01-01

    Animal models and behavioral paradigms are critical for elucidating the neural mechanism involved in complex behaviors, including social cognition. Both genotype and phenotype based models have implicated the neuropeptide oxytocin (OT) in the regulation of social behavior. Based on the findings in animal models, alteration of the OT system has been hypothesized to play a role in the social deficits associated with autism and other neuropsychiatric disorders. While the evidence linking the peptide to the etiology of the disorder is not yet conclusive, evidence from multiple animal models suggest modulation of the OT system may be a viable strategy for the pharmacological treatment of social deficits. In this review, we will discuss how animal models have been utilized to understand the role of OT in social cognition and how those findings can be applied to the conceptualization and treatment of the social impairments in ASD. Animal models with genetic alterations of the OT system, like the OT, OT receptor and CD38 knock-out mice, and those with phenotypic variation in social behavior, like BTBR inbred mice and prairie voles, coupled with behavioral paradigms with face and construct validity may prove to have predictive validity for identifying the most efficacious methods of stimulating the OT system to enhance social cognition in humans. The widespread use of strong animal models of social cognition has the potential yield pharmacological, interventions for the treatment social impairments psychiatric disorders. This article is part of a Special Issue entitled Oxytocin, Vasopressin, and Social Behavior. PMID:22206823

  8. The oxytocin system in drug discovery for autism: animal models and novel therapeutic strategies.

    PubMed

    Modi, Meera E; Young, Larry J

    2012-03-01

    Animal models and behavioral paradigms are critical for elucidating the neural mechanism involved in complex behaviors, including social cognition. Both genotype and phenotype based models have implicated the neuropeptide oxytocin (OT) in the regulation of social behavior. Based on the findings in animal models, alteration of the OT system has been hypothesized to play a role in the social deficits associated with autism and other neuropsychiatric disorders. While the evidence linking the peptide to the etiology of the disorder is not yet conclusive, evidence from multiple animal models suggest modulation of the OT system may be a viable strategy for the pharmacological treatment of social deficits. In this review, we will discuss how animal models have been utilized to understand the role of OT in social cognition and how those findings can be applied to the conceptualization and treatment of the social impairments in ASD. Animal models with genetic alterations of the OT system, like the OT, OT receptor and CD38 knock-out mice, and those with phenotypic variation in social behavior, like BTBR inbred mice and prairie voles, coupled with behavioral paradigms with face and construct validity may prove to have predictive validity for identifying the most efficacious methods of stimulating the OT system to enhance social cognition in humans. The widespread use of strong animal models of social cognition has the potential yield pharmacological, interventions for the treatment social impairments psychiatric disorders. This article is part of a Special Issue entitled Oxytocin, Vasopressin, and Social Behavior. PMID:22206823

  9. A novel SPECT camera for molecular imaging of the prostate

    NASA Astrophysics Data System (ADS)

    Cebula, Alan; Gilland, David; Su, Li-Ming; Wagenaar, Douglas; Bahadori, Amir

    2011-10-01

    The objective of this work is to develop an improved SPECT camera for dedicated prostate imaging. Complementing the recent advancements in agents for molecular prostate imaging, this device has the potential to assist in distinguishing benign from aggressive cancers, to improve site-specific localization of cancer, to improve accuracy of needle-guided prostate biopsy of cancer sites, and to aid in focal therapy procedures such as cryotherapy and radiation. Theoretical calculations show that the spatial resolution/detection sensitivity of the proposed SPECT camera can rival or exceed 3D PET and further signal-to-noise advantage is attained with the better energy resolution of the CZT modules. Based on photon transport simulation studies, the system has a reconstructed spatial resolution of 4.8 mm with a sensitivity of 0.0001. Reconstruction of a simulated prostate distribution demonstrates the focal imaging capability of the system.

  10. Potential Application of Electronic Olfaction Systems in Feedstuffs Analysis and Animal Nutrition

    PubMed Central

    Campagnoli, Anna; Dell'Orto, Vittorio

    2013-01-01

    Electronic Olfaction Systems (EOSs) based on a variety of gas-sensing technologies have been developed to simulate in a simplified manner animal olfactory sensing systems. EOSs have been successfully applied to many applications and fields, including food technology and agriculture. Less information is available for EOS applications in the feed technology and animal nutrition sectors. Volatile Organic Compounds (VOCs), which are derived from both forages and concentrate ingredients of farm animal rations, are considered and described in this review as olfactory markers for feedstock quality and safety evaluation. EOS applications to detect VOCs from feedstuffs (as analytical matrices) are described, and some future scenarios are hypothesised. Furthermore, some EOS applications in animal feeding behaviour and organoleptic feed assessment are also described. PMID:24172280

  11. Design and in vivo evaluation of a robotized needle insertion system for small animals.

    PubMed

    Goffin, Laurent; Bour, Gaetan; Martel, Fernand; Nicolau, Stephane; Gangloff, Jacques; Egly, Jean-Marc; Bayle, Bernard

    2013-08-01

    The development of imaging devices adapted to small animals has opened the way to image-guided procedures in biomedical research. In this paper, we focus on automated procedures to study the effects of the recurrent administration of substances to the same animal over time. A dedicated system and the associated workflow have been designed to percutaneously position a needle into the abdominal organs of mice. Every step of the procedure has been automated: the camera calibration, the needle access planning, the robotized needle positioning, and the respiratory-gated needle insertion. Specific devices have been developed for the registration, the animal binding under anesthesia, and the skin puncture. Among the presented results, the system accuracy is particularly emphasized, both in vitro using gelose phantoms and in vivo by injecting substances into various abdominal organs. The study shows that robotic assistance could be routinely used in biomedical research laboratories to improve existing procedures, allowing automated accurate treatments and limited animal sacrifices. PMID:23475327

  12. Design and development of a position-sensitive γ-camera for SPECT imaging based on PCI electronics

    NASA Astrophysics Data System (ADS)

    Spanoudaki, V.; Giokaris, N. D.; Karabarbounis, A.; Loudos, G. K.; Maintas, D.; Papanicolas, C. N.; Paschalis, P.; Stiliaris, E.

    2004-07-01

    A position-sensitive γ-camera is being currently designed at IASA. This camera will be used experimentally (development mode) in order to obtain an integrated knowledge of its function and perhaps to improve its performance in parallel with an existing one, which has shown a very good performance in phantom, small animal, SPECT technique and is currently being tested for clinical applications. The new system is a combination of a PSPMT (Hamamatsu, R2486-05) and a PMT for simultaneous or independent acquisition of energy and position information, respectively. The resistive chain technique resulting in two signals at each ( X, Y) direction will perform the readout of the PSPMT's anode signals; the system is based on PCI electronics. Status of the system's development and the ongoing progress is presented.

  13. SPECT assay of radiolabeled monoclonal antibodies. Third yearly progress report, September 1991--February 1992

    SciTech Connect

    Jaszczak, R.J.

    1992-02-01

    The accurate determination of the biodistribution of radiolabeled monoclonal antibodies (MoAbs) is important for calculation of dosimetry and evaluation of pharmacokinetic variables such as antibody dose and route of administration. The hypothesis of this application is that the biodistribution of radiolabeled monoclonal antibodies (MoAbs) can be quantitatively determined using single photon emission computed tomography (SPECT). The major thrusts during the third year include the continued development and evaluation of improved 3D SPECT acquisition and reconstruction approaches to improve quantitative imaging of radiolabeled monoclonal antibodies (MoAbs), and the implementation and evaluation of algorithms to register serial SPECT image data sets, or to register 3D SPECT images with 3D image data sets acquired from positron emission tomography (PEI) and magnetic resonance images (MRI). The research has involved the investigation of statistical models and iterative reconstruction algorithms that accurately account for the physical characteristics of the SPECT acquisition system. It is our belief that SPECT quantification can be improved by accurately modeling the physical processes such as attenuation, scatter, geometric collimator response, and other factors that affect the measured projection data.

  14. Application of statistical process control charts to monitor changes in animal production systems.

    PubMed

    De Vries, A; Reneau, J K

    2010-04-01

    Statistical process control (SPC) is a method of monitoring, controlling, and improving a process through statistical analysis. An important SPC tool is the control chart, which can be used to detect changes in production processes, including animal production systems, with a statistical level of confidence. This paper introduces the philosophy and types of control charts, design and performance issues, and provides a review of control chart applications in animal production systems found in the literature from 1977 to 2009. Primarily Shewhart and cumulative sum control charts have been described in animal production systems, with examples found in poultry, swine, dairy, and beef production systems. Examples include monitoring of growth, disease incidence, water intake, milk production, and reproductive performance. Most applications describe charting outcome variables, but more examples of control charts applied to input variables are needed, such as compliance to protocols, feeding practice, diet composition, and environmental factors. Common challenges for applications in animal production systems are the identification of the best statistical model for the common cause variability, grouping of data, selection of type of control chart, the cost of false alarms and lack of signals, and difficulty identifying the special causes when a change is signaled. Nevertheless, carefully constructed control charts are powerful methods to monitor animal production systems. Control charts might also supplement randomized controlled trials. PMID:20081080

  15. A SPECT imager with synthetic collimation

    PubMed Central

    Havelin, Ronan J.; Miller, Brian W.; Barrett, Harrison H.; Furenlid, Lars R.; Murphy, J M; Foley, Mark J.

    2015-01-01

    This work outlines the development of a multi-pinhole SPECT system designed to produce a synthetic-collimator image of a small field of view. The focused multi-pinhole collimator was constructed using rapid-prototyping and casting techniques. The collimator projects the field of view through forty-six pinholes when the detector is adjacent to the collimator. The detector is then moved further from the collimator to increase the magnification of the system. The amount of pinhole-projection overlap increases with the system magnification. There is no rotation in the system; a single tomographic angle is used in each system configuration. The maximum-likelihood expectation-maximization (MLEM) algorithm is implemented on graphics processing units to reconstruct the object in the field of view. Iterative reconstruction algorithms, such as MLEM, require an accurate model of the system response. For each system magnification, a sparsely-sampled system response is measured by translating a point source through a grid encompassing the field of view. The pinhole projections are individually identified and associated with their respective apertures. A 2D elliptical Gaussian model is applied to the pinhole projections on the detector. These coefficients are associated with the object-space location of the point source, and a finely-sampled system matrix is interpolated. Simulations with a hot-rod phantom demonstrate the efficacy of combining low-resolution non-multiplexed data with high-resolution multiplexed data to produce high-resolution reconstructions. PMID:26346410

  16. Molecular imaging of gene expression and protein function in vivo with PET and SPECT.

    PubMed

    Sharma, Vijay; Luker, Gary D; Piwnica-Worms, David

    2002-10-01

    Molecular imaging is broadly defined as the characterization and measurement of biological processes in living animals, model systems, and humans at the cellular and molecular level using remote imaging detectors. One underlying premise of molecular imaging is that this emerging field is not defined by the imaging technologies that underpin acquisition of the final image per se, but rather is driven by the underlying biological questions. In practice, the choice of imaging modality and probe is usually reduced to choosing between high spatial resolution and high sensitivity to address a given biological system. Positron emission tomography (PET) and single-photon emission computed tomography (SPECT) inherently use image-enhancing agents (radiopharmaceuticals) that are synthesized at sufficiently high specific activity to enable use of tracer concentrations of the compound (picomolar to nanomolar) for detecting molecular signals while providing the desired levels of image contrast. The tracer technologies strategically provide high sensitivity for imaging small-capacity molecular systems in vivo (receptors, enzymes, transporters) at a cost of lower spatial resolution than other technologies. We review several significant PET and SPECT advances in imaging receptors (somatostatin receptor subtypes, neurotensin receptor subtypes, alpha(v)beta(3) integrin), enzymes (hexokinase, thymidine kinase), transporters (MDR1 P-glycoprotein, sodium-iodide symporter), and permeation peptides (human immunodeficiency virus type 1 (HIV-1) Tat conjugates), as well as innovative reporter gene constructs (herpes simplex virus 1 thymidine kinase, somatostatin receptor subtype 2, cytosine deaminase) for imaging gene promoter activation and repression, signal transduction pathways, and protein-protein interactions in vivo. PMID:12353250

  17. Real-time animation software for customized training to use motor prosthetic systems.

    PubMed

    Davoodi, Rahman; Loeb, Gerald E

    2012-03-01

    Research on control of human movement and development of tools for restoration and rehabilitation of movement after spinal cord injury and amputation can benefit greatly from software tools for creating precisely timed animation sequences of human movement. Despite their ability to create sophisticated animation and high quality rendering, existing animation software are not adapted for application to neural prostheses and rehabilitation of human movement. We have developed a software tool known as MSMS (MusculoSkeletal Modeling Software) that can be used to develop models of human or prosthetic limbs and the objects with which they interact and to animate their movement using motion data from a variety of offline and online sources. The motion data can be read from a motion file containing synthesized motion data or recordings from a motion capture system. Alternatively, motion data can be streamed online from a real-time motion capture system, a physics-based simulation program, or any program that can produce real-time motion data. Further, animation sequences of daily life activities can be constructed using the intuitive user interface of Microsoft's PowerPoint software. The latter allows expert and nonexpert users alike to assemble primitive movements into a complex motion sequence with precise timing by simply arranging the order of the slides and editing their properties in PowerPoint. The resulting motion sequence can be played back in an open-loop manner for demonstration and training or in closed-loop virtual reality environments where the timing and speed of animation depends on user inputs. These versatile animation utilities can be used in any application that requires precisely timed animations but they are particularly suited for research and rehabilitation of movement disorders. MSMS's modeling and animation tools are routinely used in a number of research laboratories around the country to study the control of movement and to develop and test

  18. 75 FR 50987 - Privacy Act System of Records; National Animal Health Laboratory Network (NAHLN)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-18

    ...The U.S. Department of Agriculture (USDA) proposes to add a new Privacy Act system of records to its inventory of records systems subject to the Privacy Act of 1974, as amended, and invites public comment on this new records system. The system of records being proposed is the National Animal Health Laboratory Network. This notice is necessary to meet the requirements of the Privacy Act to......

  19. SPECT functional brain imaging. Technical considerations.

    PubMed

    Devous, M D

    1995-07-01

    The technical aspects of functional brain single-photon emission computed tomography (SPECT) imaging, referring primarily to the most common SPECT brain function measure--regional cerebral blood flow--are reviewed. SPECT images of regional cerebral blood flow are influenced by a number of factors unrelated to pathology, including tomographic quality, radiopharmaceuticals, environmental conditions at the time of radiotracer administration, characteristics of the subject (e.g., age, sex), image presentation, and image processing techniques. Modern SPECT scans yield excellent image quality, and instrumentation continues to improve. The armamentarium of regional cerebral blood flow and receptor radiopharmaceuticals is rapidly expanding. Standards regarding the environment for patient imaging and image presentation are emerging. However, there is still much to learn about the circumstances for performances and evaluation of SPECT functional brain imaging. Challenge tests, primarily established in cerebrovascular disease (i.e., the acetazolamide test), offer great promise in defining the extent and nature of disease, as well as predicting therapeutic responses. Clearly, SPECT brain imaging is a powerful clinical and research tool. However, SPECT will only achieve its full potential in the management of patients with cerebral pathology through close cooperation among members of the nuclear medicine, neurology, psychiatry, neurosurgery, and internal medicine specialties. PMID:7626833

  20. First Robotic SPECT for Minimally Invasive Sentinel Lymph Node Mapping.

    PubMed

    Fuerst, Bernhard; Sprung, Julian; Pinto, Francisco; Frisch, Benjamin; Wendler, Thomas; Simon, Hervé; Mengus, Laurent; van den Berg, Nynke S; van der Poel, Henk G; van Leeuwen, Fijs W B; Navab, Nassir

    2016-03-01

    In this paper we present the usage of a drop-in gamma probe for intra-operative Single-Photon Emission Computed Tomography (SPECT) imaging in the scope of minimally invasive robot-assisted interventions. The probe is designed to be inserted and reside inside the abdominal cavity during the intervention. It is grasped during the procedure using a robotic laparoscopic gripper enabling full six degrees of freedom handling by the surgeon. We demonstrate the first deployment of the tracked probe for intra-operative in-patient robotic SPECT enabling augmented-reality image guidance. The hybrid mechanical- and image-based in-patient probe tracking is shown to have an accuracy of 0.2 mm. The overall system performance is evaluated and tested with a phantom for gynecological sentinel lymph node interventions and compared to ground-truth data yielding a mean reconstruction accuracy of 0.67 mm. PMID:26561283

  1. Accuracy of quantitative reconstructions in SPECT/CT imaging

    NASA Astrophysics Data System (ADS)

    Shcherbinin, S.; Celler, A.; Belhocine, T.; van der Werf, R.; Driedger, A.

    2008-09-01

    The goal of this study was to determine the quantitative accuracy of our OSEM-APDI reconstruction method based on SPECT/CT imaging for Tc-99m, In-111, I-123, and I-131 isotopes. Phantom studies were performed on a SPECT/low-dose multislice CT system (Infinia-Hawkeye-4 slice, GE Healthcare) using clinical acquisition protocols. Two radioactive sources were centrally and peripherally placed inside an anthropometric Thorax phantom filled with non-radioactive water. Corrections for attenuation, scatter, collimator blurring and collimator septal penetration were applied and their contribution to the overall accuracy of the reconstruction was evaluated. Reconstruction with the most comprehensive set of corrections resulted in activity estimation with error levels of 3-5% for all the isotopes.

  2. An environmental chamber system for prolonged metabolic studies on small animals

    NASA Technical Reports Server (NTRS)

    Jordan, J. P.; Huston, L. J.; Simmons, J. B., II; Clarkson, D. P.; Martz, W. W.; Schatte, C. L.

    1973-01-01

    Measurement of metabolic adaptation to marginally stressful environments requires both precise regulation of a variety of atmospheric factors for extended periods of time and the capacity to employ sensitive parameters in an undisturbed subject. This paper describes a metabolic chamber system which can simultaneously maintain groups of small animals in two completely separate closed environments having different pressures, temperatures and gas compositions for an indefinite period. Oxygen consumption, carbon dioxide production, food and water consumption and animal activity cycles can be continuously monitored and quantified 24 h per day while the animals are in an unrestrained state. Each chamber can be serviced and the animals handled, injected and sacrificed without subjecting them to barometric stress. Several unique electrical and mechanical components allow semi-automated data collection on a continuous basis for indefinite periods of time.

  3. SPECT Myocardial Blood Flow Quantitation Concludes Equivocal Myocardial Perfusion SPECT Studies to Increase Diagnostic Benefits.

    PubMed

    Chen, Lung-Ching; Lin, Chih-Yuan; Chen, Ing-Jou; Ku, Chi-Tai; Chen, Yen-Kung; Hsu, Bailing

    2016-01-01

    Recently, myocardial blood flow quantitation with dynamic SPECT/CT has been reported to enhance the detection of coronary artery disease in human. This advance has created important clinical applications to coronary artery disease diagnosis and management for areas where myocardial perfusion PET tracers are not available. We present 2 clinical cases that undergone a combined test of 1-day rest/dipyridamole-stress dynamic SPECT and ECG-gated myocardial perfusion SPECT scans using an integrated imaging protocol and demonstrate that flow parameters are capable to conclude equivocal myocardial perfusion SPECT studies, therefore increasing diagnostic benefits to add value in making clinical decisions. PMID:26053731

  4. The influence of gravity on the process of development of animal systems

    NASA Technical Reports Server (NTRS)

    Malacinski, G. M.; Neff, A. W.

    1984-01-01

    The development of animal systems is described in terms of a series of overlapping phases: pattern specification; differentiation; growth; and aging. The extent to which altered (micro) gravity (g) affects those phases is briefly reviewed for several animal systems. As a model, amphibian egg/early embryo is described. Recent data derived from clinostat protocols indicates that microgravity simulation alters early pattern specification (dorsal/ventral polarity) but does not adversely influence subsequent morphogenesis. Possible explanations for the absence of catastrophic microgravity effects on amphibian embryogenesis are discussed.

  5. Environmental control and life support systems analysis for a Space Station life sciences animal experiment

    NASA Technical Reports Server (NTRS)

    So, Kenneth T.; Hall, John B., Jr.; Thompson, Clifford D.

    1987-01-01

    NASA's Langley and Goddard facilities have evaluated the effects of animal science experiments on the Space Station's Environmental Control and Life Support System (ECLSS) by means of computer-aided analysis, assuming an animal colony consisting of 96 rodents and eight squirrel monkeys. Thirteen ECLSS options were established for the reclamation of metabolic oxygen and waste water. Minimum cost and weight impacts on the ECLSS are found to accrue to the system's operation in off-nominal mode, using electrochemical CO2 removal and a static feed electrolyzer for O2 generation.

  6. A multi-channel telemetry system for brain microstimulation in freely roaming animals.

    PubMed

    Xu, Shaohua; Talwar, Sanjiv K; Hawley, Emerson S; Li, Lei; Chapin, John K

    2004-02-15

    A system is described that enables an experimenter to remotely deliver electrical pulse train stimuli to multiple different locations in the brains of freely moving rats. The system consists of two separate components: a transmitter base station that is controlled by a PC operator, and a receiver-microprocessor integrated pack worn on the back of the animals and which connects to suitably implanted brain locations. The backpack is small and light so that small animal subjects can easily carry it. Under remote command from the PC the backpack can be configured to provide biphasic pulse trains of arbitrarily specified parameters. A feature of the system is that it generates precise brain-stimulation behavioral effects using the direct constant-voltage TTL output of the backpack microprocessor. The system performs with high fidelity even in complex environments over a distance of about 300 m. Rat self-stimulation tests showed that this system produced the same behavioral responses as a conventional constant-current stimulator. This system enables a variety of multi-channel brain stimulation experiments in freely moving animals. We have employed it to develop a new animal behavior model ("virtual" conditioning) for the neurophysiological study of spatial learning, in which a rat can be accurately guided to navigate various terrains. PMID:14757345

  7. Estimating farm-gate ammonia emissions from major animal production systems in China

    NASA Astrophysics Data System (ADS)

    Gao, Zhiling; Ma, Wenqi; Zhu, Gaodi; Roelcke, Marco

    2013-11-01

    Ammonia (NH3) emissions from livestock production in China are an important contributor to the global NH3 budget. In this study, by estimating total nitrogen (N) intake based on herd structures and excreted N, a mass balance model was used to estimate NH3 losses from animal housing and manure storage facilities of dairy cattle, beef cattle, pigs, broiler and layer productions within animal farm gate and their corresponding NH3 emission intensities on the basis of animal products, N and protein in animal products. In 2009, NH3 emissions from pigs, layers, beef and dairy cattle and broiler production systems in China were 1.23, 0.52, 0.24, 0.21 and 0.09 million tons, respectively. The NH3 emission intensities were 26.6 g NH3-N kg-1 of pork, 28.1 g NH3-N kg-1 of layer eggs, 39.4 g NH3-N kg-1 of beef meat, 6.0 g NH3-N kg-1 of dairy milk and 4.6 g NH3-N kg-1 of chicken meat, or 1260 (pigs), 1514 (layers), 1297 (beef), 1107 (dairy) and 123 g NH3-N (broilers) kg-1 N in animal products. Of the sectors of NH3 emission, manure storage facilities and farmyard manure (FYM) in animal housing were the major contributors to the total NH3 emissions except for layers; housing emissions from slurry were also major contributors for dairy and pig production.

  8. SPECT assay of radiolabeled monoclonal antibodies

    SciTech Connect

    Jaszczak, R.J.

    1992-02-01

    The long-term goal of this research project is to develop methods to improve the utility of single photon emission computed tomography (SPECI) to quantify the biodistribution of monoclonal antibodies (MoAbs) labeled with clinically relevant radionuclides ({sup 123}I, {sup 131}I, and {sup 111}In) and with another radionuclide,{sup 211}At, recently used in therapy. We describe here our progress in developing quantitative SPECT methodology for {sup 111}In and {sup 123}I. We have focused our recent research thrusts on the following aspects of SPECT: (1) The development of improved SPECT hardware, such as improved acquisition geometries. (2) The development of better reconstruction methods that provide accurate compensation for the physical factors that affect SPECT quantification. (3) The application of carefully designed simulations and experiments to validate our hardware and software approaches.

  9. Single Photon Emission Computed Tomography (SPECT)

    MedlinePlus

    ... High Blood Pressure Tools & Resources Stroke More Single Photon Emission Computed Tomography (SPECT) Updated:Sep 11,2015 ... Persantine) or dobutamine. The tests may take between 2 and 2 1/2 hours. What happens after ...

  10. On the Use of a Simple Physical System Analogy to Study Robustness Features in Animal Sciences

    PubMed Central

    Sadoul, Bastien; Martin, Olivier; Prunet, Patrick; Friggens, Nicolas C.

    2015-01-01

    Environmental perturbations can affect the health, welfare, and fitness of animals. Being able to characterize and phenotype adaptive capacity is therefore of growing scientific concern in animal ecology and in animal production sciences. Terms borrowed from physics are commonly used to describe adaptive responses of animals facing an environmental perturbation, but no quantitative characterization of these responses has been made. Modeling the dynamic responses to an acute challenge was used in this study to facilitate the characterization of adaptive capacity and therefore robustness. A simple model based on a spring and damper was developed to simulate the dynamic responses of animals facing an acute challenge. The parameters characterizing the spring and the damper can be interpreted in terms of stiffness and resistance to the change of the system. The model was tested on physiological and behavioral responses of rainbow trout facing an acute confinement challenge. The model has proven to properly fit the different responses measured in this study and to quantitatively describe the different temporal patterns for each statistical individual in the study. It provides therefore a new way to explicitly describe, analyze and compare responses of individuals facing an acute perturbation. This study suggests that such physical models may be usefully applied to characterize robustness in many other biological systems. PMID:26322508

  11. Cerebral SPECT imaging: Impact on clinical management

    SciTech Connect

    Bloom, M.; Jacobs, S.; Pozniakof, T.

    1994-05-01

    Although cerebral SPECT has been reported to be of value in a variety of neurologic disorders, there is limited data available on the value of SPECT relative to clinical management decisions. The purpose of this study was to determine the effect of cerebral SPECT imaging on patient management. A total of 94 consecutive patients referred for clinical evaluation with brain SPECT were included in this study. Patients were assigned to one of nine groups depending on the clinical indication for the study. These groups included transient ischemia (16), stroke (20), dementia (18), seizures (5), hemorrhage (13), head trauma (6), arteriovenous malformations (6), encephalopathy (6) and a miscellaneous (4) group. All patients were injected with 99mTc HMPAO in doses ranging from 15 mCi to 22 mCi (555 MBq to 814 MBq) and scanned on a triple headed SPECT gamma camera. Two weeks after completion of the study, a standardized interview was conducted between the nuclear and referring physicians to determine if the SPECT findings contributed to an alteration in patient management. Overall, patient management was significantly altered in 47% of the cases referred. The greatest impact on patient management occurred in the group evaluated for transient ischemia, where a total of 13/16 (81%) of patients had their clinical management altered as a result of the cerebral SPECT findings. Clinical management was altered in 61% of patients referred for evaluation of dementia, 67% of patients evaluated for arteriovenous malformations, and 50% of patients with head trauma. In the remainder of the patients, alteration in clinical management ranged from 17% to 50% of patients. This study demonstrates the clinical utility of cerebral SPECT imaging since in a significant number of cases clinical management was altered as a result of the examination. Long term follow up will be necessary to determine patient outcome.

  12. Temperature dependent operation of PSAPD-based compact gamma camera for SPECT imaging.

    PubMed

    Kim, Sangtaek; McClish, Mickel; Alhassen, Fares; Seo, Youngho; Shah, Kanai S; Gould, Robert G

    2011-10-10

    We investigated the dependence of image quality on the temperature of a position sensitive avalanche photodiode (PSAPD)-based small animal single photon emission computed tomography (SPECT) gamma camera with a CsI:Tl scintillator. Currently, nitrogen gas cooling is preferred to operate PSAPDs in order to minimize the dark current shot noise. Being able to operate a PSAPD at a relatively high temperature (e.g., 5 °C) would allow a more compact and simple cooling system for the PSAPD. In our investigation, the temperature of the PSAPD was controlled by varying the flow of cold nitrogen gas through the PSAPD module and varied from -40 °C to 20 °C. Three experiments were performed to demonstrate the performance variation over this temperature range. The point spread function (PSF) of the gamma camera was measured at various temperatures, showing variation of full-width-half-maximum (FWHM) of the PSF. In addition, a (99m)Tc-pertechnetate (140 keV) flood source was imaged and the visibility of the scintillator segmentation (16×16 array, 8 mm × 8 mm area, 400 μm pixel size) at different temperatures was evaluated. Comparison of image quality was made at -25 °C and 5 °C using a mouse heart phantom filled with an aqueous solution of (99m)Tc-pertechnetate and imaged using a 0.5 mm pinhole collimator made of tungsten. The reconstructed image quality of the mouse heart phantom at 5 °C degraded in comparision to the reconstructed image quality at -25 °C. However, the defect and structure of the mouse heart phantom were clearly observed, showing the feasibility of operating PSAPDs for SPECT imaging at 5 °C, a temperature that would not need the nitrogen cooling. All PSAPD evaluations were conducted with an applied bias voltage that allowed the highest gain at a given temperature. PMID:24465051

  13. Temperature dependent operation of PSAPD-based compact gamma camera for SPECT imaging

    PubMed Central

    Kim, Sangtaek; McClish, Mickel; Alhassen, Fares; Seo, Youngho; Shah, Kanai S.; Gould, Robert G.

    2011-01-01

    We investigated the dependence of image quality on the temperature of a position sensitive avalanche photodiode (PSAPD)-based small animal single photon emission computed tomography (SPECT) gamma camera with a CsI:Tl scintillator. Currently, nitrogen gas cooling is preferred to operate PSAPDs in order to minimize the dark current shot noise. Being able to operate a PSAPD at a relatively high temperature (e.g., 5 °C) would allow a more compact and simple cooling system for the PSAPD. In our investigation, the temperature of the PSAPD was controlled by varying the flow of cold nitrogen gas through the PSAPD module and varied from −40 °C to 20 °C. Three experiments were performed to demonstrate the performance variation over this temperature range. The point spread function (PSF) of the gamma camera was measured at various temperatures, showing variation of full-width-half-maximum (FWHM) of the PSF. In addition, a 99mTc-pertechnetate (140 keV) flood source was imaged and the visibility of the scintillator segmentation (16×16 array, 8 mm × 8 mm area, 400 μm pixel size) at different temperatures was evaluated. Comparison of image quality was made at −25 °C and 5 °C using a mouse heart phantom filled with an aqueous solution of 99mTc-pertechnetate and imaged using a 0.5 mm pinhole collimator made of tungsten. The reconstructed image quality of the mouse heart phantom at 5 °C degraded in comparision to the reconstructed image quality at −25 °C. However, the defect and structure of the mouse heart phantom were clearly observed, showing the feasibility of operating PSAPDs for SPECT imaging at 5 °C, a temperature that would not need the nitrogen cooling. All PSAPD evaluations were conducted with an applied bias voltage that allowed the highest gain at a given temperature. PMID:24465051

  14. Use of a ray-based reconstruction algorithm to accurately quantify preclinical microSPECT images.

    PubMed

    Vandeghinste, Bert; Van Holen, Roel; Vanhove, Christian; De Vos, Filip; Vandenberghe, Stefaan; Staelens, Steven

    2014-01-01

    This work aimed to measure the in vivo quantification errors obtained when ray-based iterative reconstruction is used in micro-single-photon emission computed tomography (SPECT). This was investigated with an extensive phantom-based evaluation and two typical in vivo studies using 99mTc and 111In, measured on a commercially available cadmium zinc telluride (CZT)-based small-animal scanner. Iterative reconstruction was implemented on the GPU using ray tracing, including (1) scatter correction, (2) computed tomography-based attenuation correction, (3) resolution recovery, and (4) edge-preserving smoothing. It was validated using a National Electrical Manufacturers Association (NEMA) phantom. The in vivo quantification error was determined for two radiotracers: [99mTc]DMSA in naive mice (n  =  10 kidneys) and [111In]octreotide in mice (n  =  6) inoculated with a xenograft neuroendocrine tumor (NCI-H727). The measured energy resolution is 5.3% for 140.51 keV (99mTc), 4.8% for 171.30 keV, and 3.3% for 245.39 keV (111In). For 99mTc, an uncorrected quantification error of 28 ± 3% is reduced to 8 ± 3%. For 111In, the error reduces from 26 ± 14% to 6 ± 22%. The in vivo error obtained with 99mTc-dimercaptosuccinic acid ([99mTc]DMSA) is reduced from 16.2 ± 2.8% to -0.3 ± 2.1% and from 16.7 ± 10.1% to 2.2 ± 10.6% with [111In]octreotide. Absolute quantitative in vivo SPECT is possible without explicit system matrix measurements. An absolute in vivo quantification error smaller than 5% was achieved and exemplified for both [99mTc]DMSA and [111In]octreotide. PMID:24824961

  15. Chapter 5: Quantifying greenhouse gas sources and sinks in animal production systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The purpose of this publication is to develop methods to quantify greenhouse gas emissions (GHG) from U.S. agriculture and forestry. This chapter provides guidance for reporting GHG emissions from animal production systems. In particular, it focuses on methods for estimating emissions from beef cat...

  16. Augmenting Instructional Animations with a Body Analogy to Help Children Learn about Physical Systems.

    PubMed

    Pouw, Wim T J L; van Gog, Tamara; Zwaan, Rolf A; Paas, Fred

    2016-01-01

    We investigated whether augmenting instructional animations with a body analogy (BA) would improve 10- to 13-year-old children's learning about class-1 levers. Children with a lower level of general math skill who learned with an instructional animation that provided a BA of the physical system, showed higher accuracy on a lever problem-solving reaction time task than children studying the instructional animation without this BA. Additionally, learning with a BA led to a higher speed-accuracy trade-off during the transfer task for children with a lower math skill, which provided additional evidence that especially this group is likely to be affected by learning with a BA. However, overall accuracy and solving speed on the transfer task was not affected by learning with or without this BA. These results suggest that providing children with a BA during animation study provides a stepping-stone for understanding mechanical principles of a physical system, which may prove useful for instructional designers. Yet, because the BA does not seem effective for all children, nor for all tasks, the degree of effectiveness of body analogies should be studied further. Future research, we conclude, should be more sensitive to the necessary degree of analogous mapping between the body and physical systems, and whether this mapping is effective for reasoning about more complex instantiations of such physical systems. PMID:27375538

  17. What's Inside Bodies? Learning about Skeletons and Other Organ Systems of Vertebrate Animals.

    ERIC Educational Resources Information Center

    Tunnicliffe, Sue Dale; Reiss, Michael

    This paper describes a study of young children's understanding of what is on the inside of animals--skeletons and other organ systems. The study uses 2-D drawings based on the idea that a drawing is the representational model and is the outward expression of the mental model. The 617 drawings made by participants in the study were awarded one of…

  18. Augmenting Instructional Animations with a Body Analogy to Help Children Learn about Physical Systems

    PubMed Central

    Pouw, Wim T. J. L.; van Gog, Tamara; Zwaan, Rolf A.; Paas, Fred

    2016-01-01

    We investigated whether augmenting instructional animations with a body analogy (BA) would improve 10- to 13-year-old children’s learning about class-1 levers. Children with a lower level of general math skill who learned with an instructional animation that provided a BA of the physical system, showed higher accuracy on a lever problem-solving reaction time task than children studying the instructional animation without this BA. Additionally, learning with a BA led to a higher speed–accuracy trade-off during the transfer task for children with a lower math skill, which provided additional evidence that especially this group is likely to be affected by learning with a BA. However, overall accuracy and solving speed on the transfer task was not affected by learning with or without this BA. These results suggest that providing children with a BA during animation study provides a stepping-stone for understanding mechanical principles of a physical system, which may prove useful for instructional designers. Yet, because the BA does not seem effective for all children, nor for all tasks, the degree of effectiveness of body analogies should be studied further. Future research, we conclude, should be more sensitive to the necessary degree of analogous mapping between the body and physical systems, and whether this mapping is effective for reasoning about more complex instantiations of such physical systems. PMID:27375538

  19. Improvements in animal productivity and health with a total aerobic manure management system

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The aim of this study was to evaluate the effects of improved manure management using second generation technology on air and water quality and the beneficial effect of a cleaner environment on animal productivity and health. The technology is a lower cost, second generation treatment system develop...

  20. Efficiency of a skid-mounted pyrolysis system for power production from animal manures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study is to evaluate the efficiency of a skid-mounted pyrolysis system for power production from animal manures: chicken litter; swine solids; and swine solids blended with rye grass. Eight to 19 liters of dried manures were used as feedstocks for the skid-mounted pyrolysis ste...

  1. Use of Gamagrass as Hay or Silage in animal Production Systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The use of native grasses to improve wildlife habitat is receiving consideration by conservation and wildlife interests. The potential use of native grasses in animal production systems, and particularly as conserved forage, has received little attention. Two experiments in each of 2 yr were condu...

  2. Courseware Development with Animated Pedagogical Agents in Learning System to Improve Learning Motivation

    ERIC Educational Resources Information Center

    Chin, Kai-Yi; Hong, Zeng-Wei; Huang, Yueh-Min; Shen, Wei-Wei; Lin, Jim-Min

    2016-01-01

    The addition of animated pedagogical agents (APAs) in computer-assisted learning (CAL) systems could successfully enhance students' learning motivation and engagement in learning activities. Conventionally, the APA incorporated multimedia materials are constructed through the cooperation of teachers and software programmers. However, the thinking…

  3. Modelling, Simulation, Animation, and Real-Time Control (Mosart) for a Class of Electromechanical Systems: A System-Theoretic Approach

    ERIC Educational Resources Information Center

    Rodriguez, Armando A.; Metzger, Richard P.; Cifdaloz, Oguzhan; Dhirasakdanon, Thanate; Welfert, Bruno

    2004-01-01

    This paper describes an interactive modelling, simulation, animation, and real-time control (MoSART) environment for a class of 'cart-pendulum' electromechanical systems that may be used to enhance learning within differential equations and linear algebra classes. The environment is useful for conveying fundamental mathematical/systems concepts…

  4. An automated robot arm system for small animal tissue biopsy under dual-image modality

    NASA Astrophysics Data System (ADS)

    Huang, Y. H.; Wu, T. H.; Lin, M. H.; Yang, C. C.; Guo, W. Y.; Wang, Z. J.; Chen, C. L.; Lee, J. S.

    2006-12-01

    The ability to non-invasively monitor cell biology in vivo is one of the most important goals of molecular imaging. Imaging procedures could be inter-subject performed repeatedly at different investigating stages; thereby need not sacrifice small animals during the entire study period. Thus, the ultimate goal of this study was to design a stereotactic image-guided system for small animals and integrated it with an automatic robot arm for in vivo tissue biopsy analysis. The system was composed of three main parts, including one small animal stereotactic frame, one imaging-fusion software and an automatic robot arm system. The system has been thoroughly evaluated with three components; the robot position accuracy was 0.05±0.02 mm, the image registration accuracy was 0.37±0.18 mm and the system integration was satisfactorily within 1.20±0.39 mm of error. From these results, the system demonstrated sufficient accuracy to guide the micro-injector from the planned delivery routes into practice. The entire system accuracy was limited by the image fusion and orientation procedures, due to its nature of the blurred PET imaging obtained from the small objects. The primary improvement is to acquire as higher resolution as possible the fused imaging for localizing the targets in the future.

  5. Systems Approaches to Animal Disease Surveillance and Resource Allocation: Methodological Frameworks for Behavioral Analysis

    PubMed Central

    Rich, Karl M.; Denwood, Matthew J.; Stott, Alistair W.; Mellor, Dominic J.; Reid, Stuart W. J.; Gunn, George J.

    2013-01-01

    While demands for animal disease surveillance systems are growing, there has been little applied research that has examined the interactions between resource allocation, cost-effectiveness, and behavioral considerations of actors throughout the livestock supply chain in a surveillance system context. These interactions are important as feedbacks between surveillance decisions and disease evolution may be modulated by their contextual drivers, influencing the cost-effectiveness of a given surveillance system. This paper identifies a number of key behavioral aspects involved in animal health surveillance systems and reviews some novel methodologies for their analysis. A generic framework for analysis is discussed, with exemplar results provided to demonstrate the utility of such an approach in guiding better disease control and surveillance decisions. PMID:24348922

  6. Reasoning visualization in expert systems - The applicability of algorithm animation techniques

    NASA Technical Reports Server (NTRS)

    Selig, William J.; Johannes, James D.

    1990-01-01

    This paper presents the results of research into providing a means for users to flexibly create visualizations of the reasoning processes of forward-chaining rule-based expert systems using algorithm animation techniques. Levels of reasoning are described in order to identify the information necessary from the expert system development environment for these visualizations. A dual-process visualization environment is presented consisting of: (1) a version of CLIPS modified for the identified information access requirements; and (2) VISOR, an algorithm animation-based system for creating visualizations of arbitrary complexity which can be triggered by 'interesting event' messages from the running expert-system application. This is followed by examples from several visualizations performed during the scope of this work.

  7. A programmable closed-loop recording and stimulating wireless system for behaving small laboratory animals

    NASA Astrophysics Data System (ADS)

    Angotzi, Gian Nicola; Boi, Fabio; Zordan, Stefano; Bonfanti, Andrea; Vato, Alessandro

    2014-08-01

    A portable 16-channels microcontroller-based wireless system for a bi-directional interaction with the central nervous system is presented in this work. The device is designed to be used with freely behaving small laboratory animals and allows recording of spontaneous and evoked neural activity wirelessly transmitted and stored on a personal computer. Biphasic current stimuli with programmable duration, frequency and amplitude may be triggered in real-time on the basis of the recorded neural activity as well as by the animal behavior within a specifically designed experimental setup. An intuitive graphical user interface was developed to configure and to monitor the whole system. The system was successfully tested through bench tests and in vivo measurements on behaving rats chronically implanted with multi-channels microwire arrays.

  8. A programmable closed-loop recording and stimulating wireless system for behaving small laboratory animals

    PubMed Central

    Angotzi, Gian Nicola; Boi, Fabio; Zordan, Stefano; Bonfanti, Andrea; Vato, Alessandro

    2014-01-01

    A portable 16-channels microcontroller-based wireless system for a bi-directional interaction with the central nervous system is presented in this work. The device is designed to be used with freely behaving small laboratory animals and allows recording of spontaneous and evoked neural activity wirelessly transmitted and stored on a personal computer. Biphasic current stimuli with programmable duration, frequency and amplitude may be triggered in real-time on the basis of the recorded neural activity as well as by the animal behavior within a specifically designed experimental setup. An intuitive graphical user interface was developed to configure and to monitor the whole system. The system was successfully tested through bench tests and in vivo measurements on behaving rats chronically implanted with multi-channels microwire arrays. PMID:25096831

  9. CT with a CMOS flat panel detector integrated on the YAP-(S)PET scanner for in vivo small animal imaging

    NASA Astrophysics Data System (ADS)

    Di Domenico, Giovanni; Cesca, Nicola; Zavattini, Guido; Auricchio, Natalia; Gambaccini, Mauro

    2007-02-01

    Several research groups are pursuing multimodality simultaneous functional and morphological imaging. In this line of research the high resolution YAP-(S)PET small animal integrated PET-SPECT imaging system, constructed by our group of medical physics at the University of Ferrara, is being upgraded with a computed tomography (CT). In this way it will be possible to perform in vivo molecular and genomic imaging studies on small animals (such as mice and rats) and at the same time obtain morphological information necessary for both attenuation correction and accurate localization of the region under investigation. We have take simultaneous PET-CT and SPECT-CT images of phantoms obtained with a single scanner.

  10. Microbiomes: unifying animal and plant systems through the lens of community ecology theory.

    PubMed

    Christian, Natalie; Whitaker, Briana K; Clay, Keith

    2015-01-01

    The field of microbiome research is arguably one of the fastest growing in biology. Bacteria feature prominently in studies on animal health, but fungi appear to be the more prominent functional symbionts for plants. Despite the similarities in the ecological organization and evolutionary importance of animal-bacterial and plant-fungal microbiomes, there is a general failure across disciplines to integrate the advances made in each system. Researchers studying bacterial symbionts in animals benefit from greater access to efficient sequencing pipelines and taxonomic reference databases, perhaps due to high medical and veterinary interest. However, researchers studying plant-fungal symbionts benefit from the relative tractability of fungi under laboratory conditions and ease of cultivation. Thus each system has strengths to offer, but both suffer from the lack of a common conceptual framework. We argue that community ecology best illuminates complex species interactions across space and time. In this synthesis we compare and contrast the animal-bacterial and plant-fungal microbiomes using six core theories in community ecology (i.e., succession, community assembly, metacommunities, multi-trophic interactions, disturbance, restoration). The examples and questions raised are meant to spark discussion amongst biologists and lead to the integration of these two systems, as well as more informative, manipulatory experiments on microbiomes research. PMID:26441846

  11. Microbiomes: unifying animal and plant systems through the lens of community ecology theory

    PubMed Central

    Christian, Natalie; Whitaker, Briana K.; Clay, Keith

    2015-01-01

    The field of microbiome research is arguably one of the fastest growing in biology. Bacteria feature prominently in studies on animal health, but fungi appear to be the more prominent functional symbionts for plants. Despite the similarities in the ecological organization and evolutionary importance of animal-bacterial and plant–fungal microbiomes, there is a general failure across disciplines to integrate the advances made in each system. Researchers studying bacterial symbionts in animals benefit from greater access to efficient sequencing pipelines and taxonomic reference databases, perhaps due to high medical and veterinary interest. However, researchers studying plant–fungal symbionts benefit from the relative tractability of fungi under laboratory conditions and ease of cultivation. Thus each system has strengths to offer, but both suffer from the lack of a common conceptual framework. We argue that community ecology best illuminates complex species interactions across space and time. In this synthesis we compare and contrast the animal-bacterial and plant–fungal microbiomes using six core theories in community ecology (i.e., succession, community assembly, metacommunities, multi-trophic interactions, disturbance, restoration). The examples and questions raised are meant to spark discussion amongst biologists and lead to the integration of these two systems, as well as more informative, manipulatory experiments on microbiomes research. PMID:26441846

  12. Human-animal bonds II: the role of pets in family systems and family therapy.

    PubMed

    Walsh, Froma

    2009-12-01

    The vast majority of pet owners regard their companion animals as family members, yet the role of pets in family systems and family therapy has received little attention in research, training, and practice. This article first notes the benefits of family pets and their importance for resilience. It then examines their role in couple and family processes and their involvement in relational dynamics and tensions. Next, it addresses bereavement in the loss of a cherished pet, influences complicating grief, and facilitation of mourning and adaptation. Finally, it explores the ways that clients' pets and the use of therapists' companion animals in animal-assisted therapy can inform and enrich couple and family therapy as valuable resources in healing. PMID:19930434

  13. Investigation of dynamic SPECT measurements of the arterial input function in human subjects using simulation, phantom and human studies

    PubMed Central

    Winant, Celeste D; Aparici, Carina Mari; Zelnik, Yuval R; Reutter, Bryan W; Sitek, Arkadiusz; Bacharach, Stephen L; Gullberg, Grant T

    2012-01-01

    Computer simulations, a phantom study and a human study were performed to determine whether a slowly rotating single-photon computed emission tomography (SPECT) system could provide accurate arterial input functions for quantification of myocardial perfusion imaging using kinetic models. The errors induced by data inconsistency associated with imaging with slow camera rotation during tracer injection were evaluated with an approach called SPECT/P (dynamic SPECT from positron emission tomography (PET)) and SPECT/D (dynamic SPECT from database of SPECT phantom projections). SPECT/P simulated SPECT-like dynamic projections using reprojections of reconstructed dynamic 94Tc-methoxyisobutylisonitrile (94Tc-MIBI) PET images acquired in three human subjects (1 min infusion). This approach was used to evaluate the accuracy of estimating myocardial wash-in rate parameters K1 for rotation speeds providing 180° of projection data every 27 or 54 s. Blood input and myocardium tissue time-activity curves (TACs) were estimated using spatiotemporal splines. These were fit to a one-compartment perfusion model to obtain wash-in rate parameters K1. For the second method (SPECT/D), an anthropomorphic cardiac torso phantom was used to create real SPECT dynamic projection data of a tracer distribution derived from 94Tc-MIBI PET scans in the blood pool, myocardium, liver and background. This method introduced attenuation, collimation and scatter into the modeling of dynamic SPECT projections. Both approaches were used to evaluate the accuracy of estimating myocardial wash-in parameters for rotation speeds providing 180° of projection data every 27 and 54 s. Dynamic cardiac SPECT was also performed in a human subject at rest using a hybrid SPECT/CT scanner. Dynamic measurements of 99mTc-tetrofosmin in the myocardium were obtained using an infusion time of 2 min. Blood input, myocardium tissue and liver TACs were estimated using the same spatiotemporal splines. The spatiotemporal maximum

  14. A small animal holding fixture system with positional reproducibility for longitudinal multimodal imaging

    NASA Astrophysics Data System (ADS)

    Kokuryo, Daisuke; Kimura, Yuichi; Obata, Takayuki; Yamaya, Taiga; Kawamura, Kazunori; Zhang, Ming-Rong; Kanno, Iwao; Aoki, Ichio

    2010-07-01

    This study presents a combined small animal holding fixture system, termed a 'bridge capsule', which provides for small animal re-fixation with positional reproducibility. This system comprises separate holding fixtures for the head and lower body and a connecting part to a gas anesthesia system. A mouse is fixed in place by the combination of a head fixture with a movable part made from polyacetal resin, a lower body fixture made from vinyl-silicone and a holder for the legs and tail. For re-fixation, a similar posture could be maintained by the same holding fixtures and a constant distance between the head and lower body fixtures is maintained. Artifacts caused by the bridge capsule system were not observed on magnetic resonance (MRI) and positron emission tomography (PET) images. The average position differences of the spinal column and the iliac body before and after re-fixation for the same modality were approximately 1.1 mm. The difference between the MRI and PET images was approximately 1.8 mm for the lower body fixture after image registration using fiducial markers. This system would be useful for longitudinal, repeated and multimodal imaging experiments requiring similar animal postures.

  15. Forty research issues for the redesign of animal production systems in the 21st century.

    PubMed

    Dumont, B; González-García, E; Thomas, M; Fortun-Lamothe, L; Ducrot, C; Dourmad, J Y; Tichit, M

    2014-08-01

    Agroecology offers a scientific and operational framework for redesigning animal production systems (APS) so that they better cope with the coming challenges. Grounded in the stimulation and valorization of natural processes to reduce inputs and pollutions in agroecosystems, it opens a challenging research agenda for the animal science community. In this paper, we identify key research issues that define this agenda. We first stress the need to assess animal robustness by measurable traits, to analyze trade-offs between production and adaptation traits at within-breed and between-breed level, and to better understand how group selection, epigenetics and animal learning shape performance. Second, we propose research on the nutritive value of alternative feed resources, including the environmental impacts of producing these resources and their associated non-provisioning services. Third, we look at how the design of APS based on agroecological principles valorizes interactions between system components and promotes biological diversity at multiple scales to increase system resilience. Addressing such challenges requires a collection of theories and models (concept-knowledge theory, viability theory, companion modeling, etc.). Acknowledging the ecology of contexts and analyzing the rationales behind traditional small-scale systems will increase our understanding of mechanisms contributing to the success or failure of agroecological practices and systems. Fourth, the large-scale development of agroecological products will require analysis of resistance to change among farmers and other actors in the food chain. Certifications and market-based incentives could be an important lever for the expansion of agroecological alternatives in APS. Finally, we question the suitability of current agriculture extension services and public funding mechanisms for scaling-up agroecological practices and systems. PMID:24871266

  16. Pediatric solid tumors: Evaluation by gallium-67 SPECT studies

    SciTech Connect

    Rossleigh, M.A.; Murray, I.P.; Mackey, D.W.; Bargwanna, K.A.; Nayanar, V.V. )

    1990-02-01

    A retrospective review of 37 children with a variety of solid tumors who underwent 60 {sup 67}Ga single-photon emission computed tomographic (SPECT) studies was performed. These studies were correlated with clinical and radiological findings and, where possible, histopathologic confirmation. In all studies, SPECT gave better definition and better anatomic localization of disease sites than obtained with planar views. SPECT detected more lesions in the head and neck (planar 16, SPECT 19), chest (planar 39, SPECT 45), and abdomen (planar 22, SPECT 24). In six of 20 patients scanned following chemotherapy, SPECT was useful in demonstrating that tracer accumulation in a normally located and shaped thymus indicated uptake resulting from thymic regeneration rather than tumor recurrence. It is concluded that {sup 67}Ga SPECT studies are very useful in the pediatric population, where perhaps because of their small size, interpretation of standard planar views may be difficult.

  17. Optical methods and integrated systems for brain imaging in awake, untethered animals

    NASA Astrophysics Data System (ADS)

    Murari, Kartikeya

    Imaging is a powerful tool for biomedical research offering non-contact and minimally or non-invasive means of investigating at multiple scales---from single molecules to large populations of cells. Imaging in awake, behaving animals is an emerging field that offers the additional advantage of being able to study physiological processes and structures in a more natural state than what is possible in tissue slices or even in anesthetized animals. To date, most imaging in awake animals has used optical fiber bundles or electrical cables to transfer signals to traditional imaging-system components. However, the fibers or cables tether the animal and greatly limit the kind and duration of animal behavior that can be studied using imaging methods. This work involves three distinct yet related approaches to fulfill the goal of imaging in unanesthetized, unrestrained animals---optical techniques for functional and structural imaging, development of novel photodetectors and the design of miniaturized imaging systems. I hypothesized that the flow within vessels might act as a contrast-enhancing agent and improve the visualization of vascular architecture using laser speckle imaging. When imaging rodent cerebral vasculature I saw a two to four fold increase in the contrast-to-noise ratios and was able to visualize 10--30% more vascular features over reflectance techniques. I designed a complementary metal oxide semiconductor (CMOS) photodetector array that was comparable in sensitivity and noise performance to cooled CCD sensors, able to image fluorescence from a single cell, while running at faster frame rates. Next, I designed an imaging system weighing under 6 grams and occupying less than 4 cm3. The system incorporated multispectral illumination, adjustable focusing optics and the high-sensitivity CMOS imager. I was able to implement a variety of optical modalities with the system and performed reflectance, fluorescence, spectroscopic and laser speckle imaging with my

  18. Comparison of two detector systems for cone beam CT small animal imaging - a preliminary study

    PubMed Central

    Meng, Yang; Shaw, Chris C.; Liu, Xinming; Altunbas, Mustafa C.; Wang, Tianpeng; Chen, Lingyun; Tu, Shu-Ju; Kappadath, S. Cheenu; Lai, Chao-Jen

    2007-01-01

    Purpose To compare two detector systems - one based on the charge-coupled device (CCD) and image amplifier, the other based on a-Si/CsI flat panel, for cone beam computed-tomography (CT) imaging of small animals. A high resolution, high framing rate detector system for the cone beam CT imaging of small animals was developed. The system consists of a 2048×3072×12 bit CCD optically coupled to an image amplifier and an x-ray phosphor screen. The CCD has an intrinsic pixel size of 12 μm but the effective pixel size can be adjusted through the magnification adjustment of the optical coupling systems. The system is used in conjunction with an x-ray source and a rotating stage for holding and rotating the scanned object in the cone beam CT imaging experiments. The advantages of the system include but are not limited to the ability to adjust the effective pixel size and to achieve extremely high spatial resolution and temporal resolution. However, the need to use optical coupling compromises the detective quanta efficiency (DQE) of the system. In this paper, the imaging characteristics of the system were presented and compared with those of an a-Si/CsI flat-panel detector system. PMID:18160972

  19. Modelling photon transport in non-uniform media for SPECT with a vectorized Monte Carlo code.

    PubMed

    Smith, M F

    1993-10-01

    A vectorized Monte Carlo code has been developed for modelling photon transport in non-uniform media for single-photon-emission computed tomography (SPECT). The code is designed to compute photon detection kernels, which are used to build system matrices for simulating SPECT projection data acquisition and for use in matrix-based image reconstruction. Non-uniform attenuating and scattering regions are constructed from simple three-dimensional geometric shapes, in which the density and mass attenuation coefficients are individually specified. On a Stellar GS1000 computer, Monte Carlo simulations are performed between 1.6 and 2.0 times faster when the vector processor is utilized than when computations are performed in scalar mode. Projection data acquired with a clinical SPECT gamma camera for a line source in a non-uniform thorax phantom are well modelled by Monte Carlo simulations. The vectorized Monte Carlo code was used to stimulate a 99Tcm SPECT myocardial perfusion study, and compensations for non-uniform attenuation and the detection of scattered photons improve activity estimation. The speed increase due to vectorization makes Monte Carlo simulation more attractive as a tool for modelling photon transport in non-uniform media for SPECT. PMID:8248288

  20. SPECT imaging in a case of primary respiratory tract amyloidosis.

    PubMed

    Nishihara, M; Oda, J; Kamura, T; Kimura, M; Odano, I; Sakai, K

    1993-08-01

    SPECT findings in a very rare case of primary amyloidosis localized in the laryngotracheobronchial area are reported. SPECT using Tc-99m PYP revealed widespread uptake in the larynx and the entire tracheobronchial tree up to the subsegmental divisions; the areas corresponded to diffuse thickening and calcification of the walls on CT. SPECT using Ga-67 citrate also showed marked uptake in the same area, consistent with the findings shown by SPECT using Tc-99m PYP. PMID:8403700

  1. A classic model animal in the 21st century: recent lessons from the leech nervous system.

    PubMed

    Wagenaar, Daniel A

    2015-11-01

    The medicinal leech (genus Hirudo) is a classic model animal in systems neuroscience. The leech has been central to many integrative studies that establish how properties of neurons and their interconnections give rise to the functioning of the animal at the behavioral level. Leeches exhibit several discrete behaviors (such as crawling, swimming and feeding) that are each relatively simple. Importantly, these behaviors can all be studied - at least at a basal level - in the isolated nervous system. The leech nervous system is particularly amenable to such studies because of its distributed nature; sensory processing and generation of behavior occur to a large degree in iterated segmental ganglia that each contain only ∼400 neurons. Furthermore, the neurons are relatively large and are arranged with stereotyped topography on the surface of the ganglion, which greatly facilitates their identification and accessibility. This Commentary provides an overview of recent work on the leech nervous system, with particular focus on circuits that underlie leech behavior. Studies that combine the unique features of the leech with modern optical and genetic techniques are also discussed. Thus, this Commentary aims to explain the continued appeal of the leech as an experimental animal in the 21st century. PMID:26538172

  2. Global positioning system and associated technologies in animal behaviour and ecological research

    USGS Publications Warehouse

    Tomkiewicz, Stanley M.; Fuller, Mark R.; Kie, John G.; Bates, Kirk K.

    2010-01-01

    Biologists can equip animals with global positioning system (GPS) technology to obtain accurate (less than or equal to 30 m) locations that can be combined with sensor data to study animal behaviour and ecology. We provide the background of GPS techniques that have been used to gather data for wildlife studies. We review how GPS has been integrated into functional systems with data storage, data transfer, power supplies, packaging and sensor technologies to collect temperature, activity, proximity and mortality data from terrestrial species and birds. GPS 'rapid fixing' technologies combined with sensors provide location, dive frequency and duration profiles, and underwater acoustic information for the study of marine species. We examine how these rapid fixing technologies may be applied to terrestrial and avian applications. We discuss positional data quality and the capability for high-frequency sampling associated with GPS locations. We present alternatives for storing and retrieving data by using dataloggers (biologging), radio-frequency download systems (e.g. very high frequency, spread spectrum), integration of GPS with other satellite systems (e.g. Argos, Globalstar) and potential new data recovery technologies (e.g. network nodes). GPS is one component among many rapidly evolving technologies. Therefore, we recommend that users and suppliers interact to ensure the availability of appropriate equipment to meet animal research objectives.

  3. Human-induced changes in animal populations and distributions, and the subsequent effects on fluvial systems

    NASA Astrophysics Data System (ADS)

    Butler, David R.

    2006-09-01

    Humans have profoundly altered hydrological pathways and fluvial systems through their near-extirpation of native populations of animal species that strongly influenced hydrology and removal of surface sediment, and through the introduction of now-feral populations of animals that bring to bear a suite of different geomorphic effects on the fluvial system. In the category of effects of extirpation, examples are offered through an examination of the geomorphic effects and former spatial extent of beavers, bison, prairie dogs, and grizzly bears. Beavers entrapped hundreds of billions of cubic meters of sediment in North American stream systems prior to European contact. Individual bison wallows, that numbered in the range of 100 million wallows, each displaced up to 23 m 3 of sediment. Burrowing by prairie dogs displaced more than 5000 kg and possibly up to 67,500 kg of sediment per hectare. In the category of feral populations, the roles of feral rabbits, burros and horses, and pigs are highlighted. Much work remains to adequately quantify the geomorphic effects animals have on fluvial systems, but the influence is undeniable.

  4. Global positioning system and associated technologies in animal behaviour and ecological research.

    PubMed

    Tomkiewicz, Stanley M; Fuller, Mark R; Kie, John G; Bates, Kirk K

    2010-07-27

    Biologists can equip animals with global positioning system (GPS) technology to obtain accurate (less than or equal to 30 m) locations that can be combined with sensor data to study animal behaviour and ecology. We provide the background of GPS techniques that have been used to gather data for wildlife studies. We review how GPS has been integrated into functional systems with data storage, data transfer, power supplies, packaging and sensor technologies to collect temperature, activity, proximity and mortality data from terrestrial species and birds. GPS 'rapid fixing' technologies combined with sensors provide location, dive frequency and duration profiles, and underwater acoustic information for the study of marine species. We examine how these rapid fixing technologies may be applied to terrestrial and avian applications. We discuss positional data quality and the capability for high-frequency sampling associated with GPS locations. We present alternatives for storing and retrieving data by using dataloggers (biologging), radio-frequency download systems (e.g. very high frequency, spread spectrum), integration of GPS with other satellite systems (e.g. Argos, Globalstar) and potential new data recovery technologies (e.g. network nodes). GPS is one component among many rapidly evolving technologies. Therefore, we recommend that users and suppliers interact to ensure the availability of appropriate equipment to meet animal research objectives. PMID:20566494

  5. Global positioning system and associated technologies in animal behaviour and ecological research

    PubMed Central

    Tomkiewicz, Stanley M.; Fuller, Mark R.; Kie, John G.; Bates, Kirk K.

    2010-01-01

    Biologists can equip animals with global positioning system (GPS) technology to obtain accurate (less than or equal to 30 m) locations that can be combined with sensor data to study animal behaviour and ecology. We provide the background of GPS techniques that have been used to gather data for wildlife studies. We review how GPS has been integrated into functional systems with data storage, data transfer, power supplies, packaging and sensor technologies to collect temperature, activity, proximity and mortality data from terrestrial species and birds. GPS ‘rapid fixing’ technologies combined with sensors provide location, dive frequency and duration profiles, and underwater acoustic information for the study of marine species. We examine how these rapid fixing technologies may be applied to terrestrial and avian applications. We discuss positional data quality and the capability for high-frequency sampling associated with GPS locations. We present alternatives for storing and retrieving data by using dataloggers (biologging), radio-frequency download systems (e.g. very high frequency, spread spectrum), integration of GPS with other satellite systems (e.g. Argos, Globalstar) and potential new data recovery technologies (e.g. network nodes). GPS is one component among many rapidly evolving technologies. Therefore, we recommend that users and suppliers interact to ensure the availability of appropriate equipment to meet animal research objectives. PMID:20566494

  6. Liquid breathing trials and animal studies with a demand-regulated liquid breathing system.

    PubMed

    Moskowitz, G D; Shaffer, T H; Dubin, S E

    1975-01-01

    Experimental results of in vivo animal tests conducted on a demand-regulated liquid breathing system are presented. When a liquid replaces gas as the medium in which oxygen and carbon dioxide are transported, several problems not typical in gas respiration occur. The increased mass and viscosity of a liquid as compared with a gas necessitate some means of mechanical assistance. The lower diffusion rates of gases in liquids as compared with gas rates places several constraints on the design of a mechanically assisted liquid breathing system. The liquid breathing system reported in this study has been designed to be demand-regulated, i.e., the animal has control over cycling the pumps which mechanically assist the circulation of an oxygenated liquid to and from the lungs. This system consists of a gas-operated diaphragm pump, demand controller, liquid regenerator with heater and gas scrubber, and ancillary equipment. A demand controller is described which obtains a control signal from an esophageal balloon catheter in the animal and governs operation of the pneumatically driven diaphragm pump. PMID:1055284

  7. Columnar transmitter based wireless power delivery system for implantable device in freely moving animals.

    PubMed

    Eom, Kyungsik; Jeong, Joonsoo; Lee, Tae Hyung; Lee, Sung Eun; Jun, Sang Bum; Kim, Sung June

    2013-01-01

    A wireless power delivery system is developed to deliver electrical power to the neuroprosthetic devices that are implanted into animals freely moving inside the cage. The wireless powering cage is designed for long-term animal experiments without cumbersome wires for power supply or the replacement of batteries. In the present study, we propose a novel wireless power transmission system using resonator-based inductive links to increase power efficiency and to minimize the efficiency variations. A columnar transmitter coil is proposed to provide lateral uniformity of power efficiency. Using this columnar transmitter coil, only 7.2% efficiency fluctuation occurs from the maximum transmission efficiency of 25.9%. A flexible polymer-based planar type receiver coil is fabricated and assembled with a neural stimulator and an electrode. Using the designed columnar transmitter coil, the implantable device successfully operates while it moves freely inside the cage. PMID:24110073

  8. Simultaneous SPECT imaging of multi-targets to assist in identifying hepatic lesions

    PubMed Central

    Guo, Zhide; Gao, Mengna; Zhang, Deliang; Li, Yesen; Song, Manli; Zhuang, Rongqiang; Su, Xinhui; Chen, Guibing; Liu, Ting; Liu, Pingguo; Wu, Hua; Du, Jin; Zhang, Xianzhong

    2016-01-01

    Molecular imaging technique is an attractive tool to detect liver disease at early stage. This study aims to develop a simultaneous dual-isotope single photon emission computed tomography (SPECT)/CT imaging method to assist diagnosis of hepatic tumor and liver fibrosis. Animal models of liver fibrosis and orthotopic human hepatocellular carcinoma (HCC) were established. The tracers of 131I-NGA and 99mTc-3P-RGD2 were selected to target asialoglycoprotein receptor (ASGPR) on the hepatocytes and integrin αvβ3 receptor in tumor or fibrotic liver, respectively. SPECT imaging and biodistribution study were carried out to verify the feasibility and superiority. As expected, 99mTc-3P-RGD2 had the ability to evaluate liver fibrosis and detect tumor lesions. 131I-NGA showed that it was effective in assessing the anatomy and function of the liver. In synchronized dual-isotope SPECT/CT imaging, clear fusion images can be got within 30 minutes for diagnosing liver fibrosis and liver cancer. This new developed imaging approach enables the acquisition of different physiological information for diagnosing liver fibrosis, liver cancer and evaluating residual functional liver volume simultaneously. So synchronized dual-isotope SPECT/CT imaging with 99mTc-3P-RGD2 and 131I-NGA is an effective approach to detect liver disease, especially liver fibrosis and liver cancer. PMID:27377130

  9. Simultaneous SPECT imaging of multi-targets to assist in identifying hepatic lesions.

    PubMed

    Guo, Zhide; Gao, Mengna; Zhang, Deliang; Li, Yesen; Song, Manli; Zhuang, Rongqiang; Su, Xinhui; Chen, Guibing; Liu, Ting; Liu, Pingguo; Wu, Hua; Du, Jin; Zhang, Xianzhong

    2016-01-01

    Molecular imaging technique is an attractive tool to detect liver disease at early stage. This study aims to develop a simultaneous dual-isotope single photon emission computed tomography (SPECT)/CT imaging method to assist diagnosis of hepatic tumor and liver fibrosis. Animal models of liver fibrosis and orthotopic human hepatocellular carcinoma (HCC) were established. The tracers of (131)I-NGA and (99m)Tc-3P-RGD2 were selected to target asialoglycoprotein receptor (ASGPR) on the hepatocytes and integrin αvβ3 receptor in tumor or fibrotic liver, respectively. SPECT imaging and biodistribution study were carried out to verify the feasibility and superiority. As expected, (99m)Tc-3P-RGD2 had the ability to evaluate liver fibrosis and detect tumor lesions. (131)I-NGA showed that it was effective in assessing the anatomy and function of the liver. In synchronized dual-isotope SPECT/CT imaging, clear fusion images can be got within 30 minutes for diagnosing liver fibrosis and liver cancer. This new developed imaging approach enables the acquisition of different physiological information for diagnosing liver fibrosis, liver cancer and evaluating residual functional liver volume simultaneously. So synchronized dual-isotope SPECT/CT imaging with (99m)Tc-3P-RGD2 and (131)I-NGA is an effective approach to detect liver disease, especially liver fibrosis and liver cancer. PMID:27377130

  10. Animal cytomegaloviruses.

    PubMed Central

    Staczek, J

    1990-01-01

    Cytomegaloviruses are agents that infect a variety of animals. Human cytomegalovirus is associated with infections that may be inapparent or may result in severe body malformation. More recently, human cytomegalovirus infections have been recognized as causing severe complications in immunosuppressed individuals. In other animals, cytomegaloviruses are often associated with infections having relatively mild sequelae. Many of these sequelae parallel symptoms associated with human cytomegalovirus infections. Recent advances in biotechnology have permitted the study of many of the animal cytomegaloviruses in vitro. Consequently, animal cytomegaloviruses can be used as model systems for studying the pathogenesis, immunobiology, and molecular biology of cytomegalovirus-host and cytomegalovirus-cell interactions. PMID:2170830

  11. Quantitative tools for comparing animal communication systems: information theory applied to bottlenose dolphin whistle repertoires.

    PubMed

    McCOWAN; Hanser; Doyle

    1999-02-01

    Comparative analysis of nonhuman animal communication systems and their complexity, particularly in comparison to human language, has been generally hampered by both a lack of sufficiently extensive data sets and appropriate analytic tools. Information theory measures provide an important quantitative tool for examining and comparing communication systems across species. In this paper we use the original application of information theory, that of statistical examination of a communication system's structure and organization. As an example of the utility of information theory to the analysis of animal communication systems, we applied a series of information theory statistics to a statistically categorized set of bottlenose dolphin Tursiops truncatus, whistle vocalizations. First, we use the first-order entropic relation in a Zipf-type diagram (Zipf 1949 Human Behavior and the Principle of Least Effort) to illustrate the application of temporal statistics as comparative indicators of repertoire complexity, and as possible predictive indicators of acquisition/learning in animal vocal repertoires. Second, we illustrate the need for more extensive temporal data sets when examining the higher entropic orders, indicative of higher levels of internal informational structure, of such vocalizations, which could begin to allow the statistical reconstruction of repertoire organization. Third, we propose using 'communication capacity' as a measure of the degree of temporal structure and complexity of statistical correlation, represented by the values of entropic order, as an objective tool for interspecies comparison of communication complexity. In doing so, we introduce a new comparative measure, the slope of Shannon entropies, and illustrate how it potentially can be used to compare the organizational complexity of vocal repertoires across a diversity of species. Finally, we illustrate the nature and predictive application of these higher-order entropies using a preliminary

  12. Countering the livestock-targeted bioterrorism threat and responding with an animal health safeguarding system.

    PubMed

    Yeh, J-Y; Lee, J-H; Park, J-Y; Cho, Y S; Cho, I-S

    2013-08-01

    Attacks against livestock and poultry using biological agents constitute a subtype of agroterrorism. These attacks are defined as the intentional introduction of an animal infectious disease to strike fear in people, damage a nation's economy and/or threaten social stability. Livestock bioterrorism is considered attractive to terrorists because biological agents for use against livestock or poultry are more readily available and difficult to monitor than biological agents for use against humans. In addition, an attack on animal husbandry can have enormous economic consequences, even without human casualties. Animal husbandry is vulnerable to livestock-targeted bioterrorism because it is nearly impossible to secure all livestock animals, and compared with humans, livestock are less well-guarded targets. Furthermore, anti-livestock biological weapons are relatively easy to employ, and a significant effect can be produced with only a small amount of infectious material. The livestock sector is presently very vulnerable to bioterrorism as a result of large-scale husbandry methods and weaknesses in the systems used to detect disease outbreaks, which could aggravate the consequences of livestock-targeted bioterrorism. Thus, terrorism against livestock and poultry cannot be thought of as either a 'low-probability' or 'low-consequence' incident. This review provides an overview of methods to prevent livestock-targeted bioterrorism and respond to terrorism involving the deliberate introduction of a pathogen-targeting livestock and poultry. PMID:22726305

  13. Good governance of animal health systems and public-private partnerships: an Australian case study.

    PubMed

    Black, P F

    2012-08-01

    The animal health system in Australia has evolved over more than 100 years and includes innovative public-private partnership arrangements. The establishment in 1996 of Animal Health Australia (AHA), a not-for-profit company, was a crucial development which formalised arrangements for shared decision-making and funding across both government and industry stakeholders. However, Federal and State governments retain legislative authority for animal health control. Accordingly, all programmes must recognise that the public sector remains an executive arm of government, accountable for its actions. Hence, much effort has been invested in ensuring that the governance arrangements within AHA are lawful and transparent. The Emergency Animal Disease Response Agreement (EADRA) is a very good example of governance arrangements that are sustainably financed, widely available, provided efficiently, without waste or duplication, and in a manner that is transparent and free of fraud or corruption. The benefits of EADRA include certainty and greater transparency of funding; greater efficiency through increased probability of a rapid response to an occurrence of any of 65 diseases; and industry participation in the management and financing of such a response. PMID:23413743

  14. An Automatic Weighting System for Wild Animals Based in an Artificial Neural Network: How to Weigh Wild Animals without Causing Stress

    PubMed Central

    Larios, Diego Francisco; Rodríguez, Carlos; Barbancho, Julio; Baena, Manuel; Leal, Miguel Ángel; Marín, Jesús; León, Carlos; Bustamante, Javier

    2013-01-01

    This paper proposes a novel and autonomous weighing system for wild animals. It allows evaluating changes in the body weight of animals in their natural environment without causing stress. The proposed system comprises a smart scale designed to estimate individual body weights and their temporal evolution in a bird colony. The system is based on computational intelligence, and offers valuable large amount of data to evaluate the relationship between long-term changes in the behavior of individuals and global change. The real deployment of this system has been for monitoring a breeding colony of lesser kestrels (Falco naumanni) in southern Spain. The results show that it is possible to monitor individual weight changes during the breeding season and to compare the weight evolution in males and females. PMID:23449117

  15. Open-Source Medical Devices (OSMD) Design of a Small Animal Radiotherapy System

    NASA Astrophysics Data System (ADS)

    Prajapati, S.; Mackie, T. R.; Jeraj, R.

    2014-03-01

    Open-Source Medical Devices (OSMD) was initiated with the goal of facilitating medical research by developing medical technologies including both hardware and software on an open-source platform. Our first project was to develop an integrated imaging and radiotherapy device for small animals that includes computed tomography (CT), positron emission tomography (PET) and radiation therapy (RT) modalities for which technical specifications were defined in the first OSMD conference held in Madison, Wisconsin, USA in December 2011. This paper specifically focuses on the development of a small animal RT (micro-RT) system by designing a binary micro multileaf collimator (bmMLC) and a small animal treatment planning system (SATPS) to enable intensity modulated RT (IMRT). Both hardware and software projects are currently under development and their current progresses are described. After the development, both bmMLC and TPS will be validated and commissioned for a micro-RT system. Both hardware design and software development will be open-sourced after completion.

  16. Vegetable oils and animal fats for diesel fuels: a systems study

    SciTech Connect

    Lipinsky, E.S.; Kresovich, S.; Wagner, C.K.; Appelbaum, H.R.; McClure, T.A.; Otis, J.L.; Trayser, D.A.

    1982-01-01

    This paper provided some information on the possible use of vegetable oils and animal fats as substitute fuels and as emergency diesel fuels in the United States. This paper is confined to using triglyceride fuels in agricultural, automotive, and highway transportation applications. Satisfactory substitution of petroleum-based diesel fuels with triglyceride-based fuels requires the development of an integrated system for the production, processing, and end use of the new fuels on a basis that is both technically attractive and economically rewarding to all of the elements of the system. The three subsystems, the farms that produce oilseed crops, the production of triglycerides and protein, and the manufacturers of the diesel engines and the owners of the present stock of auto-ignition engines, are discussed. It was concluded that vegetable oils and animal fats have substantial prospects as long-term substitutes for diesel fuels. If special auto-ignition engines were developed to handle vegetable oils, on-farm production and use might succeed. In the absence of such engine development, it is likely that large, centralized facilities to manufacture vegetable oils and their methylesters will be the successful processing route. Vegetable oils are likely to succeed first in geographical areas with benign climates. Vegetable oils and animal fats have limited prospects as diesel fuels for acute emergencies. The high viscosity of vegetable oils and the necessity to make substantial capital investments to obtain oils from oilseeds render the system relatively inflexible. 4 tables. (DP)

  17. Design and implementation of a marine animal alert system to support Marine Renewable Energy

    SciTech Connect

    Deng, Zhiqun; Carlson, Thomas J.; Fu, Tao; Ren, Huiying; Martinez, Jayson J.; Myers, Joshua R.; Matzner, Shari; Choi, Eric Y.; Copping, Andrea E.

    2013-08-08

    Power extracted from fast moving tidal currents has been identified as a potential commercial-scale source of renewable energy. Device developers and utilities are pursuing deployment of prototype tidal turbines to assess technology viability, site feasibility, and environmental interactions. Deployment of prototype turbines requires permits from a range of regulatory authorities. Ensuring the safety of marine animals, particularly those under protection of the Endangered Species Act of 1973 (ESA) and the Marine Mammal Protection Act of 1972 has emerged as a key regulatory challenge for initial MHK deployments. The greatest perceived risk to marine animals is from strike by the rotating blades of tidal turbines. Development of the marine mammal alert system (MAAS) was undertaken to support monitoring and mitigation requirements for tidal turbine deployments. The prototype system development focused on Southern Resident killer whales (SRKW), an endangered population of killer whales that frequents Puget Sound and is intermittently present in the part of the sound where deployment of prototype tidal turbines is being considered. Passive acoustics were selected as the primary means because of the vocal nature of these animals. The MAAS passive acoustic system consists of two-stage process involving the use of an energy detector and a spectrogram-based classifier to distinguish between SKRW’s calls and noise. A prototype consisting of two 2D symmetrical star arrays separated by 20 m center to center was built and evaluated in the waters of Sequim Bay using whale call playback.

  18. Anatomical-based partial volume correction for low-dose dedicated cardiac SPECT/CT.

    PubMed

    Liu, Hui; Chan, Chung; Grobshtein, Yariv; Ma, Tianyu; Liu, Yaqiang; Wang, Shi; Stacy, Mitchel R; Sinusas, Albert J; Liu, Chi

    2015-09-01

    Due to the limited spatial resolution, partial volume effect has been a major degrading factor on quantitative accuracy in emission tomography systems. This study aims to investigate the performance of several anatomical-based partial volume correction (PVC) methods for a dedicated cardiac SPECT/CT system (GE Discovery NM/CT 570c) with focused field-of-view over a clinically relevant range of high and low count levels for two different radiotracer distributions. These PVC methods include perturbation geometry transfer matrix (pGTM), pGTM followed by multi-target correction (MTC), pGTM with known concentration in blood pool, the former followed by MTC and our newly proposed methods, which perform the MTC method iteratively, where the mean values in all regions are estimated and updated by the MTC-corrected images each time in the iterative process. The NCAT phantom was simulated for cardiovascular imaging with (99m)Tc-tetrofosmin, a myocardial perfusion agent, and (99m)Tc-red blood cell (RBC), a pure intravascular imaging agent. Images were acquired at six different count levels to investigate the performance of PVC methods in both high and low count levels for low-dose applications. We performed two large animal in vivo cardiac imaging experiments following injection of (99m)Tc-RBC for evaluation of intramyocardial blood volume (IMBV). The simulation results showed our proposed iterative methods provide superior performance than other existing PVC methods in terms of image quality, quantitative accuracy, and reproducibility (standard deviation), particularly for low-count data. The iterative approaches are robust for both (99m)Tc-tetrofosmin perfusion imaging and (99m)Tc-RBC imaging of IMBV and blood pool activity even at low count levels. The animal study results indicated the effectiveness of PVC to correct the overestimation of IMBV due to blood pool contamination. In conclusion, the iterative PVC methods can achieve more accurate quantification, particularly

  19. Anatomical-based partial volume correction for low-dose dedicated cardiac SPECT/CT

    NASA Astrophysics Data System (ADS)

    Liu, Hui; Chan, Chung; Grobshtein, Yariv; Ma, Tianyu; Liu, Yaqiang; Wang, Shi; Stacy, Mitchel R.; Sinusas, Albert J.; Liu, Chi

    2015-09-01

    Due to the limited spatial resolution, partial volume effect has been a major degrading factor on quantitative accuracy in emission tomography systems. This study aims to investigate the performance of several anatomical-based partial volume correction (PVC) methods for a dedicated cardiac SPECT/CT system (GE Discovery NM/CT 570c) with focused field-of-view over a clinically relevant range of high and low count levels for two different radiotracer distributions. These PVC methods include perturbation geometry transfer matrix (pGTM), pGTM followed by multi-target correction (MTC), pGTM with known concentration in blood pool, the former followed by MTC and our newly proposed methods, which perform the MTC method iteratively, where the mean values in all regions are estimated and updated by the MTC-corrected images each time in the iterative process. The NCAT phantom was simulated for cardiovascular imaging with 99mTc-tetrofosmin, a myocardial perfusion agent, and 99mTc-red blood cell (RBC), a pure intravascular imaging agent. Images were acquired at six different count levels to investigate the performance of PVC methods in both high and low count levels for low-dose applications. We performed two large animal in vivo cardiac imaging experiments following injection of 99mTc-RBC for evaluation of intramyocardial blood volume (IMBV). The simulation results showed our proposed iterative methods provide superior performance than other existing PVC methods in terms of image quality, quantitative accuracy, and reproducibility (standard deviation), particularly for low-count data. The iterative approaches are robust for both 99mTc-tetrofosmin perfusion imaging and 99mTc-RBC imaging of IMBV and blood pool activity even at low count levels. The animal study results indicated the effectiveness of PVC to correct the overestimation of IMBV due to blood pool contamination. In conclusion, the iterative PVC methods can achieve more accurate quantification, particularly for low

  20. Gallium-SPECT in the detection of prosthetic valve endocarditis and aortic ring abscess

    SciTech Connect

    O'Brien, K.; Barnes, D.; Martin, R.H.; Rae, J.R. )

    1991-09-01

    A 52-yr-old man who had a bioprosthetic aortic valve developed Staphylococcus aureus bacteremia. Despite antibiotic therapy he had persistent pyrexia and developed new conduction system disturbances. Echocardiography did not demonstrate vegetations on the valve or an abscess, but gallium scintigraphy using SPECT clearly identified a focus of intense activity in the region of the aortic valve. The presence of valvular vegetations and a septal abscess was confirmed at autopsy. Gallium scintigraphy, using SPECT, provided a useful noninvasive method for the demonstration of endocarditis and the associated valve ring abscess.

  1. Small-animal whole-body imaging using a photoacoustic full ring array system

    NASA Astrophysics Data System (ADS)

    Xia, Jun; Guo, Zijian; Aguirre, Andres; Zhu, Quing; Wang, Lihong V.

    2011-03-01

    In this report, we present a novel 3D photoacoustic computed tomography (PACT) system for small-animal whole-body imaging. The PACT system, based on a 512-element full-ring transducer array, received photoacoustic signals primarily from a 2-mm-thick slice. The light was generated by a pulse laser, and can either illuminate from the top or be reshaped to illuminate the sample from the side, using a conical lens and an optical condenser. The PACT system was capable of acquiring an in-plane image in 1.6 s; by scanning the sample in the elevational direction, a 3D tomographic image could be constructed. We tested the system by imaging a cylindrical phantom made of human hairs immersed in a scattering medium. The reconstructed image achieved an in-plane resolution of 0.1 mm and an elevational resolution of 1 mm. After deconvolution in the elevational direction, the 3D image was found to match well with the phantom. The system was also used to image a baby mouse in situ; the spinal cord and ribs can be seen easily in the reconstructed image. Our results demonstrate that the PACT system has the potential to be used for fast small-animal whole-body tomographic imaging.

  2. Comparison of SPECT/CT and MRI in Diagnosing Symptomatic Lesions in Ankle and Foot Pain Patients: Diagnostic Performance and Relation to Lesion Type

    PubMed Central

    Ha, Seunggyun; Hong, Sung Hwan; Paeng, Jin Chul; Lee, Dong Yeon; Cheon, Gi Jeong; Arya, Amitabh; Chung, June-Key; Lee, Dong Soo; Kang, Keon Wook

    2015-01-01

    Purpose The purpose of this study was to compare the diagnostic performance of SPECT/CT and MRI in patients with ankle and foot pain, with regard to the lesion types. Materials and Methods Fifty consecutive patients with ankle and foot pain, who underwent 99mTc-MDP SPECT/CT and MRI, were retrospectively enrolled in this study. Symptomatic lesions were determined based on clinical examination and response to treatment. On MRI and SPECT/CT, detected lesions were classified as bone, ligament/tendon, and joint lesions. Uptake on SPECT/CT was assessed using a 4-grade system. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of SPECT/CT and MRI were evaluated in all detected lesions and each lesion type. Diagnostic value of uptake grade was analyzed using receiver-operating characteristics (ROC) curve analysis, and diagnostic performance was compared using Chi-square or McNemar tests. Results In overall lesions, the sensitivity, PPV and NPV of SPECT/CT for symptomatic lesions were 93%, 56%, 91%, and they were 98%, 48%, 95% for MRI. There was no significant difference between SPECT/CT and MRI. However, the specificity of SPECT/CT was significantly higher than that of MRI (48% versus 24%, P = 0.016). Uptake grade on SPECT/CT was significantly higher in symptomatic lesions (P < 0.001), and its area under curve on ROC analysis was 0.787. In the analysis of each lesion type, the specificity of SPECT/CT was poor in joint lesions compared with other lesion types and MRI (P < 0.001, respectively). MRI exhibited lower specificity than SPECT/CT in bone lesions (P = 0.004) and ligament/tendon lesions (P < 0.001). Conclusions SPECT/CT has MRI-comparable diagnostic performance for symptomatic lesions in ankle and foot pain patients. SPECT/CT and MRI exhibit different diagnostic specificity in different lesion types. SPECT/CT may be used as a complementary imaging method to MRI for enhancing diagnostic specificity. PMID:25668182

  3. Ultrahigh-speed ultrahigh-resolution adaptive optics: optical coherence tomography system for in-vivo small animal retinal imaging

    NASA Astrophysics Data System (ADS)

    Jian, Yifan; Xu, Jing; Zawadzki, Robert J.; Sarunic, Marinko V.

    2013-03-01

    Small animal models of human retinal diseases are a critical component of vision research. In this report, we present an ultrahigh-resolution ultrahigh-speed adaptive optics optical coherence tomography (AO-OCT) system for small animal retinal imaging (mouse, fish, etc.). We adapted our imaging system to different types of small animals in accordance with the optical properties of their eyes. Results of AO-OCT images of small animal retinas acquired with AO correction are presented. Cellular structures including nerve fiber bundles, capillary networks and detailed double-cone photoreceptors are visualized.

  4. [Animal experiment studies on the topical and systemic effectiveness of prednisolone-17-ethylcarbonate-21-propionate].

    PubMed

    Alpermann, H G; Sandow, J; Vogel, H G

    1986-01-01

    Prednisolone-17-ethyl carbonate-21-propionate (PrEP, Hoe 777) was tested for antiinflammatory activity in various animal models by topical and systemic administration. In those models being indicative of topical efficacy, the potency of PrEP was the same as that of desoximetasone. However, systemic effects after topical administration of PrEP in shaved skin of the dorsum of rats were relatively weak compared with the reference compound. Moreover, there were less systemic corticoid effects after s.c. administration of PrEP than after desoximetasone. Thus, PrEP is obviously a compound with a considerable split of topical and systemic activity, suggesting its testing in man for systemic effects after topical administration. PMID:3705675

  5. [Experimental animal studies on the topical and systemic activity of prednisolone-17-ethylcarbonate-21-propionate].

    PubMed

    Alpermann, H G; Sandow, J; Vogel, H G

    1982-01-01

    Prednisolone-17-ethylcarbonate-21-propionate (PrEP, Hoe 777) was tested for antiinflammatory activity in various animal models by topical and systemic administration. In those models being indicative of topical efficacy, the potency of PrEP was the same as that of desoximetasone. However, systemic effects after topical administration of PrEP in shaved skin of the dorsum of rats were relatively weak compared with the reference compound. Moreover, there were less systemic glucocorticoid effects after s.c. administration of PrEP than after desoximetasone. Thus, PrEP is obviously a compound with a considerable split of topical and systemic activity, suggesting its testing in man for systemic effects after topical administration. PMID:6981416

  6. A novel telemetric system to measure polysomnographic biopotentials in freely moving animals.

    PubMed

    Zielinski, Mark R; Gerashchenko, Ludmila; Karpova, Svetlana A; Gerashchenko, Dmitry

    2013-06-15

    Mice are by far the most widely used species for scientific research and have been used in many studies involving biopotentials, such as the electroencephalogram (EEG) and electromyogram (EMG) signals monitored for sleep analysis. Unfortunately, current methods for the analysis of these signals involve either tethered systems that are restrictive and heavy for the animal or wireless systems that use transponders that are large relative to the animal and require invasive surgery for implantation; as a result, natural behavior/activity is altered. Here, we propose a novel and inexpensive system for measuring electroencephalographic signals and other biopotentials in mice that allows for natural movement. We also evaluate the new system for the analysis of sleep architecture and EEG power during both spontaneous sleep and the sleep that follows sleep deprivation in mice. Using our new system, vigilance states including non-rapid eye movement sleep (NREMS), rapid eye movement sleep (REMS), and wakefulness, as well as EEG power and NREMS EEG delta power in the 0.5-4 Hz range (an indicator of sleep intensity) showed the diurnal rhythms typically found in mice. These values were also similar to values obtained in mice using telemetry transponders. Mice that used the new system also demonstrated enhanced NREMS EEG delta power responses that are typical following sleep deprivation and few signal artifacts. Moreover, similar movement activity counts were found when using the new system compared to a wireless system. This novel system for measuring biopotentials can be used for polysomnography, infusion, microdialysis, and optogenetic studies, reduces artifacts, and allows for a more natural moving environment and a more accurate investigation of biological systems and pharmaceutical development. PMID:23563323

  7. A novel telemetric system to measure polysomnography biopotentials in freely moving animals

    PubMed Central

    Zielinski, Mark R.; Gerashchenko, Ludmila; Karpova, Svetlana A.; Gerashchenko, Dmitry

    2013-01-01

    Mice are by far the most widely used species for scientific research including many studies involving biopotentials such as electroencephalogram (EEG) and electromyogram (EMG) signals for sleep analysis. Unfortunately, current methods for the analysis of these systems involve either tethered systems that are restrictive and heavy on the animal or wireless systems using transponders that are large relative to the animal and surgically invasive for implantation; thus natural behavior/activity is altered. Herein, we propose an inexpensive novel system for measuring electroencephalographic signals and other biopotentials in mice that allows for natural movement and evaluate it for the analysis of sleep architecture and EEG power during spontaneous sleep and sleep responses after sleep deprivation in mice. Vigilance states of non-rapid eye movement sleep (NREMS), rapid eye movement sleep (REMS), and wakefulness and EEG power and NREMS EEG delta power in the 0.5–4 Hz range (an indicator of sleep intensity) showed the typical diurnal rhythms found in mice using our new system and these values were similar to mice values using telemetry transponders. Mice that used the new system also demonstrated typical enhanced NREMS EEG delta power responses after sleep deprivation and few signal artifacts. Moreover, similar movement activity counts were found in the new system compared to a wireless system. This novel system for biopotential measuring can be used for polysomnography, infusion, microdialysate, and optogenetic studies providing a platform allowing reduced artifacts and a more natural moving environment for more accurate investigation of biological systems and pharmaceutical development. PMID:23563323

  8. Aluminum in the central nervous system (CNS): toxicity in humans and animals, vaccine adjuvants, and autoimmunity.

    PubMed

    Shaw, C A; Tomljenovic, L

    2013-07-01

    We have examined the neurotoxicity of aluminum in humans and animals under various conditions, following different routes of administration, and provide an overview of the various associated disease states. The literature demonstrates clearly negative impacts of aluminum on the nervous system across the age span. In adults, aluminum exposure can lead to apparently age-related neurological deficits resembling Alzheimer's and has been linked to this disease and to the Guamanian variant, ALS-PDC. Similar outcomes have been found in animal models. In addition, injection of aluminum adjuvants in an attempt to model Gulf War syndrome and associated neurological deficits leads to an ALS phenotype in young male mice. In young children, a highly significant correlation exists between the number of pediatric aluminum-adjuvanted vaccines administered and the rate of autism spectrum disorders. Many of the features of aluminum-induced neurotoxicity may arise, in part, from autoimmune reactions, as part of the ASIA syndrome. PMID:23609067

  9. 'I think it will eventually be done away with': Attitudes among healthcare professionals towards the current system of animal experimentation.

    PubMed

    Dignon, Andrée

    2016-08-01

    This article describes a study of attitudes to the current system of animal experimentation (for the production of health interventions) among 52 UK healthcare professionals. These healthcare professionals participated in three separate focus groups (of 18, 17 and 17 participants) and were invited to respond to the question 'what is your opinion about the current system of animal testing?' The study focused specifically on their views of the current system (rather than their views of animal testing in general). The healthcare professionals were critical of the current system, particularly with regard to regulation, secrecy, validity, unnecessary suffering and welfare. PMID:25476576

  10. Sci—Thur PM: Imaging — 05: Calibration of a SPECT/CT camera for quantitative SPECT with {sup 99m}Tc

    SciTech Connect

    Gaudin, Émilie; Montégiani, Jean-François; Després, Philippe; Beauregard, Jean-Mathieu

    2014-08-15

    While quantitation is the norm in PET, it is not widely available yet in SPECT. This work's aim was to calibrate a commercially available SPECT/CT system to perform quantitative SPECT. Counting sensitivity, dead-time (DT) constant and partial volume effect (PVE) of the system were assessed. A dual-head Siemens SymbiaT6 SPECT/CT camera equipped with low energy high-resolution collimators was studied. {sup 99m}Tc was the radioisotope of interest because of its wide usage in nuclear medicine. First, point source acquisitions were performed (activity: 30–990MBq). Further acquisitions were then performed with a uniform Jaszczak phantom filled with water at high activity (25–5000MBq). PVE was studied using 6 hot spheres (diameters: 9.9–31.2 mm) filled with {sup 99m}Tc (2.8MBq/cc) in the Jaszczak phantom, which was: (1) empty, (2) water-filled and (3) water-filled with low activity (0.1MBq/cc). The data was reconstructed with the Siemens's Flash3D iterative algorithm with 4 subsets and 8 iterations, attenuation-correction (AC) and scatter-correction (SC). DT modelling was based on the total spectrum counting rate. Sensitivity was assessed using AC-SC reconstructed SPECT data. Sensitivity and DT for the sources were 99.51±1.46cps/MBq and 0.60±0.04µs. For the phantom, sensitivity and DT were 109.9±2.3cps/MBq and 0.62±0.13µs. The recovery-coefficient varied from 5% for the 9.9mm, to 80% for the 31.2mm spheres. With our calibration methods, both sensitivity and DT constant of the SPECT camera had little dependence on the object geometry and attenuation. For small objects of known size, recovery-coefficient can be applied to correct PVE. Clinical quantitative SPECT appears to be possible and has many potential applications.

  11. Animal mdels for the study of the effects of spaceflight on the immune system

    NASA Astrophysics Data System (ADS)

    Sonnenfeld, G.

    Animal models have been used extensively to study the effects of spaceflight on the immune system. The rat has been the animal used most extensively, but some studies have also been carried out utilizing mice and rhesus monkeys. Hindlimb unloading of rats and mice is a ground-based model that has been utilized to determine the effects of spaceflight-type conditions on the immune systems. The results using this model have shown that hindlimb unloading results in alterations of functional rodent immune responses, including cytokine production, blastogenesis of leukocytes, response of bone marrow cells to colony stimulating factors, neutrophil activity, and resistance to infection. Distribution of leukocyte subtypes was not affected by hindlimb unloading. Studies on rats flown in space have demonstrated that exposure to spaceflight results in alterations in cytokine production, alterations in the ability of bone marrow cells to respond to colony stimulating factors, alterations in leukocyte subset distribution, and alterations in natural killer cell function. When pregnant rats were flown in space, although the immune responses of the pregnant mothers were altered by exposure to spaceflight, no effects of spaceflight on the immune responses of the offspring were observed. In one study, rhesus monkeys were flown in space and their immune status was evaluated upon their return to earth. Results of that study showed alterations in the ability of monkey immune cells to produce cytokines, express cytokine receptors, and respond to colony stimulating factor. Therefore, it is clear that exposure to spaceflight results in alterations in immune responses of the test animals. These changes are similar to those observed for humans that have flown in space, and demonstrate that the animal models are appropriate for studying the effects of spaceflight on the immune system. Although use of the hindlimb unloading model on the ground has indicated that exposure to the model also

  12. Efficient system modeling for a small animal PET scanner with tapered DOI detectors

    NASA Astrophysics Data System (ADS)

    Zhang, Mengxi; Zhou, Jian; Yang, Yongfeng; Rodríguez-Villafuerte, Mercedes; Qi, Jinyi

    2016-01-01

    A prototype small animal positron emission tomography (PET) scanner for mouse brain imaging has been developed at UC Davis. The new scanner uses tapered detector arrays with depth of interaction (DOI) measurement. In this paper, we present an efficient system model for the tapered PET scanner using matrix factorization and a virtual scanner geometry. The factored system matrix mainly consists of two components: a sinogram blurring matrix and a geometrical matrix. The geometric matrix is based on a virtual scanner geometry. The sinogram blurring matrix is estimated by matrix factorization. We investigate the performance of different virtual scanner geometries. Both simulation study and real data experiments are performed in the fully 3D mode to study the image quality under different system models. The results indicate that the proposed matrix factorization can maintain image quality while substantially reduce the image reconstruction time and system matrix storage cost. The proposed method can be also applied to other PET scanners with DOI measurement.

  13. Fiber optic system for in-vivo sizing of proteins in animal eye lenses

    NASA Astrophysics Data System (ADS)

    Dhadwal, Harbans S.; Ansari, Rafat R.; DellaVecchia, Michael A.; Dubin, Stephen

    1995-05-01

    A compact fiber optic system, utilizing a lensless backscatter fiber optic probe, and a semiconductor laser is used as a non-invasive tool for in vivo characterization of the proteins in the eye lens of several animals. The system exploits the extremely sensitive technique of dynamic light scattering, which uses a laser beam to probe the temporal characteristics of the proteins present in eye lens fluid. The technique, with appropriate electronics and signal processing provides a rapid means of determining the size of the (alpha) -crystallin in the protein-water system. Changes in the size of the protein molecules can be tracked over the age of the eye lens; an abrupt increase in size is associated with the early cataractous formation. This paper describes the fiber optic system and discusses results obtained from measurements made on sedated rabbits, pigs and cats. A clear difference in the size of the (alpha) -crystallin of normal and cataractous lenses is observed.

  14. Consensus report on the future of animal-free systemic toxicity testing.

    PubMed

    Leist, Marcel; Hasiwa, Nina; Rovida, Costanza; Daneshian, Mardas; Basketter, David; Kimber, Ian; Clewell, Harvey; Gocht, Tilman; Goldberg, Alan; Busquet, Francois; Rossi, Anna-Maria; Schwarz, Michael; Stephens, Martin; Taalman, Rob; Knudsen, Thomas B; McKim, James; Harris, Georgina; Pamies, David; Hartung, Thomas

    2014-01-01

    Since March 2013, animal use for cosmetics testing for the European market has been banned. This requires a renewed view on risk assessment in this field. However, in other fields as well, traditional animal experimentation does not always satisfy requirements in safety testing, as the need for human-relevant information is ever increasing. A general strategy for animal-free test approaches was outlined by the US National Research Council`s vision document for Toxicity Testing in the 21st Century in 2007. It is now possible to provide a more defined roadmap on how to implement this vision for the four principal areas of systemic toxicity evaluation: repeat dose organ toxicity, carcinogenicity, reproductive toxicity and allergy induction (skin sensitization), as well as for the evaluation of toxicant metabolism (toxicokinetics) (Fig. 1). CAAT-Europe assembled experts from Europe, America and Asia to design a scientific roadmap for future risk assessment approaches and the outcome was then further discussed and refined in two consensus meetings with over 200 stakeholders. The key recommendations include: focusing on improving existing methods rather than favoring de novo design; combining hazard testing with toxicokinetics predictions; developing integrated test strategies; incorporating new high content endpoints to classical assays; evolving test validation procedures; promoting collaboration and data-sharing of different industrial sectors; integrating new disciplines, such as systems biology and high throughput screening; and involving regulators early on in the test development process. A focus on data quality, combined with increased attention to the scientific background of a test method, will be important drivers. Information from each test system should be mapped along adverse outcome pathways. Finally, quantitative information on all factors and key events will be fed into systems biology models that allow a probabilistic risk assessment with flexible

  15. Analysis of integrated animal-fish production system under subtropical hill agro ecosystem in India: growth performance of animals, total biomass production and monetary benefit.

    PubMed

    Kumaresan, A; Pathak, K A; Bujarbaruah, K M; Vinod, K

    2009-03-01

    The present study assessed the benefits of integration of animals with fish production in optimizing the bio mass production from unit land in subtropical hill agro ecosystem. Hampshire pigs and Khaki Campbell ducks were integrated with composite fish culture. The pig and duck excreta were directly allowed into the pond and no supplementary feed was given to fish during the period of study. The average levels of N, P and K in dried pig and duck manure were 0.9, 0.7 and 0.6 per cent and 1.3, 0.6 and 0.5 per cent, respectively. The average body weight of pig and duck at 11 months age was 90 and 1.74 kg with an average daily weight gain of 333.33 and 6.44 g, respectively. The fish production in pig-fish and duck-fish systems were 2209 and 2964 kg/ha, respectively while the fish productivity in control pond was only 820 kg/ha. The total biomass (animal and fish) production was higher (p<0.05) in commercial feeding system compared to the traditional system, however the input/output ratio was 1:1.2 and 1:1.55 for commercial and traditional systems, respectively. It was inferred that the total biomass production per unit land was high (p<0.05) when animal and fish were integrated together. PMID:18622714

  16. An Implantable MEMS Micropump System for Drug Delivery in Small Animals

    PubMed Central

    Gensler, Heidi; Sheybani, Roya; Li, Po-Ying; Lo, Ronalee; Meng, Ellis

    2012-01-01

    We present the first implantable drug delivery system for controlled dosing, timing, and location in small animals. Current implantable drug delivery devices do not provide control over these factors or are not feasible for implantation in research animals as small as mice. Our system utilizes an integrated electrolysis micropump, is refillable, has an inert drug reservoir for broad drug compatibility, and is capable of adjustment to the delivery regimen while implanted. Electrochemical impedance spectroscopy (EIS) was used for characterization of electrodes on glass substrate and a flexible Parylene substrate. Benchtop testing of the electrolysis actuator resulted in flow rates from 1 to 34 μL/min on glass substrate and up to 6.8 μL/min on Parylene substrate. The fully integrated system generated a flow rate of 4.72 ± 0.35 μL/min under applied constant current of 1.0 mA while maintaining a power consumption of only ~3 mW. Finally, we demonstrated in vivo application of the system for anti-cancer drug delivery in mice. PMID:22273985

  17. Evaluation of a closed loop inductive power transmission system on an awake behaving animal subject.

    PubMed

    Kiani, Mehdi; Kwon, Ki Yong; Zhang, Fei; Oweiss, Karim; Ghovanloo, Maysam

    2011-01-01

    This paper presents in vivo experimental results for a closed loop wireless power transmission system to implantable devices on an awake behaving animal subject. In this system, wireless power transmission takes place across an inductive link, controlled by a commercial off-the-shelf (COTS) radio frequency identification (RFID) transceiver (TRF7960) operating at 13.56 MHz. Induced voltage on the implantable secondary coil is rectified, digitized by a 10-bit analog to digital converter, and transmitted back to the primary via back telemetry. Transmitter (Tx) and receiver (Rx) circuitry were mounted on the back of an adult rat with a nominal distance of ~7 mm between their coils. Our experiments showed that the closed loop system was able to maintain the Rx supply voltage at the designated 3.8 V despite changes in the coils' relative distance and alignment due to animal movements. The Tx power consumption changed between 410 ~ 560 mW in order to deliver 27 mW to the receiver. The open loop system, on the other hand, showed undesired changes in the Rx supply voltage while the Tx power consumption was constant at 660 mW. PMID:22256112

  18. Viability of decision-making systems in human and animal groups.

    PubMed

    Sueur, Cédric

    2012-08-01

    Shared and unshared consensuses are present in both human and animal societies. To date, few studies have applied an evolutionary perspective to the viability of these systems. This study therefore aimed to assess if decision-making allows group members to satisfy all their needs and to survive, decision after decision, day after day. The novelty of this study is the inclusion of multiple decision-making events with varying conditions and the parameterization of the model based on data in macaques, bringing the model closer to ecologically reality. The activity budgets of group members in the model did not differ significantly from those observed in macaques, making the model robust and providing mechanistic insight. Three different decision-making systems were then tested: (1) One single leader, (2) Leading according to needs and (3) Voting process. Results show that when individuals have equal needs, all decision-making systems are viable. However, one single leader cannot impose its decision when the needs of other group members differ too much from its own needs. The leading according to needs system is always viable whatever the group heterogeneity. However, the individual with the highest body mass decides in the majority of cases. Finally, the voting process also appears to be viable, with a majority threshold that differs according to group size and to different individual needs. This study is the first clear prediction of the different types of consensus in animal groups used in various different conditions. PMID:22554449

  19. The emerging animal health delivery system in the People's Republic of China.

    PubMed

    Bedard, B G; Hunt, T

    2004-04-01

    Livestock production in the People's Republic of China has expanded at an unprecedented rate over the last decade and this trend is expected to continue into the foreseeable future. Government and private sector investment supports this growth, and the fact that small farmers are incorporating more animal husbandry into their work is expected to mitigate some of the concerns over recent World Trade Organization accession, particularly in the more precarious grain growing regions. Modernisation and intensification of the livestock industry in the People's Republic of China is subject to significant risks as regards both infectious and production-related diseases and within the framework of food safety and public health challenges. Although historically, the veterinary service system in the People's Republic of China has been successful in the eradication and control of major disease outbreaks, domestic and international market concerns are providing the catalyst for significant reforms in the animal health delivery system in the country. This paper provides an overview of the existing veterinary system in terms of the education and qualifications of veterinary personnel, delivery mechanisms, and future approaches to reforming the system in the context of a dynamic livestock industry in transition. PMID:15200104

  20. Type III Protein Secretion Systems in Bacterial Pathogens of Animals and Plants

    PubMed Central

    Hueck, Christoph J.

    1998-01-01

    Various gram-negative animal and plant pathogens use a novel, sec-independent protein secretion system as a basic virulence mechanism. It is becoming increasingly clear that these so-called type III secretion systems inject (translocate) proteins into the cytosol of eukaryotic cells, where the translocated proteins facilitate bacterial pathogenesis by specifically interfering with host cell signal transduction and other cellular processes. Accordingly, some type III secretion systems are activated by bacterial contact with host cell surfaces. Individual type III secretion systems direct the secretion and translocation of a variety of unrelated proteins, which account for species-specific pathogenesis phenotypes. In contrast to the secreted virulence factors, most of the 15 to 20 membrane-associated proteins which constitute the type III secretion apparatus are conserved among different pathogens. Most of the inner membrane components of the type III secretion apparatus show additional homologies to flagellar biosynthetic proteins, while a conserved outer membrane factor is similar to secretins from type II and other secretion pathways. Structurally conserved chaperones which specifically bind to individual secreted proteins play an important role in type III protein secretion, apparently by preventing premature interactions of the secreted factors with other proteins. The genes encoding type III secretion systems are clustered, and various pieces of evidence suggest that these systems have been acquired by horizontal genetic transfer during evolution. Expression of type III secretion systems is coordinately regulated in response to host environmental stimuli by networks of transcription factors. This review comprises a comparison of the structure, function, regulation, and impact on host cells of the type III secretion systems in the animal pathogens Yersinia spp., Pseudomonas aeruginosa, Shigella flexneri, Salmonella typhimurium, enteropathogenic Escherichia coli

  1. Design of a multimodal fibers optic system for small animal optical imaging.

    PubMed

    Spinelli, Antonello E; Pagliazzi, Marco; Boschi, Federico

    2015-02-01

    Small animals optical imaging systems are widely used in pre-clinical research to image in vivo the bio-distribution of light emitting probes using fluorescence or bioluminescence modalities. In this work we presented a set of simulated results of a novel small animal optical imaging module based on a fibers optics matrix, coupled with a position sensitive detector, devoted to acquire bioluminescence and Cerenkov images. Simulations were performed using GEANT 4 code with the GAMOS architecture using the tissue optics plugin. Results showed that it is possible to image a 30 × 30 mm region of interest using a fiber optics array containing 100 optical fibers without compromising the quality of the reconstruction. The number of fibers necessary to cover an adequate portion of a small animal is thus quite modest. This design allows integrating the module with magnetic resonance (MR) in order to acquire optical and MR images at the same time. A detailed model of the mouse anatomy, obtained by segmentation of 3D MRI images, will improve the quality of optical 3D reconstruction. PMID:25465071

  2. Animals devoid of pulmonary system as infection models in the study of lung bacterial pathogens.

    PubMed

    López Hernández, Yamilé; Yero, Daniel; Pinos-Rodríguez, Juan M; Gibert, Isidre

    2015-01-01

    Biological disease models can be difficult and costly to develop and use on a routine basis. Particularly, in vivo lung infection models performed to study lung pathologies use to be laborious, demand a great time and commonly are associated with ethical issues. When infections in experimental animals are used, they need to be refined, defined, and validated for their intended purpose. Therefore, alternative and easy to handle models of experimental infections are still needed to test the virulence of bacterial lung pathogens. Because non-mammalian models have less ethical and cost constraints as a subjects for experimentation, in some cases would be appropriated to include these models as valuable tools to explore host-pathogen interactions. Numerous scientific data have been argued to the more extensive use of several kinds of alternative models, such as, the vertebrate zebrafish (Danio rerio), and non-vertebrate insects and nematodes (e.g., Caenorhabditis elegans) in the study of diverse infectious agents that affect humans. Here, we review the use of these vertebrate and non-vertebrate models in the study of bacterial agents, which are considered the principal causes of lung injury. Curiously none of these animals have a respiratory system as in air-breathing vertebrates, where respiration takes place in lungs. Despite this fact, with the present review we sought to provide elements in favor of the use of these alternative animal models of infection to reveal the molecular signatures of host-pathogen interactions. PMID:25699030

  3. Effect of the Zataria multiflora on Systemic Inflammation of Experimental Animals Model of COPD

    PubMed Central

    Boskabady, Mohammad Hossein; Gholami Mhtaj, Lilla

    2014-01-01

    The effects of Zataria multiflora (Z. multiflora) on systemic inflammation in guinea pigs model of COPD were examined. Control animals, COPD (induced by exposing animals to cigarette smoke), COPD + drinking water containing three concentrations of the extract of Z. multiflora, and COPD + dexamethasone were studied (n = 6 for each group). Serum levels of IL-8 and malondialdehyde (MDA), total blood WBC (P < 0.01 for all cases), and eosinophil counts (P < 0.05) were higher and weight changes (P < 0.05) were lower in the COPD group compared to controls. IL-8 level (P < 0.001) and weight changes (P < 0.01 to P < 0.001) in all treated groups with Z. multiflora and total WBC number and MDA level in treated groups with two higher concentrations of the extract and lymphocytes percentage (P < 0.05) in the highest concentration of Z. multiflora and dexamethasone (P < 0.05 to P < 0.001) were significantly improved compared to the COPD group. Results showed a preventive effect of hydroethanolic extract from Z. multiflora on all measured parameters in animals model of COPD which was comparable or even higher (in the highest concentration) compared to the effect of dexamethasone at the concentration used. PMID:25013803

  4. Animals devoid of pulmonary system as infection models in the study of lung bacterial pathogens

    PubMed Central

    López Hernández, Yamilé; Yero, Daniel; Pinos-Rodríguez, Juan M.; Gibert, Isidre

    2015-01-01

    Biological disease models can be difficult and costly to develop and use on a routine basis. Particularly, in vivo lung infection models performed to study lung pathologies use to be laborious, demand a great time and commonly are associated with ethical issues. When infections in experimental animals are used, they need to be refined, defined, and validated for their intended purpose. Therefore, alternative and easy to handle models of experimental infections are still needed to test the virulence of bacterial lung pathogens. Because non-mammalian models have less ethical and cost constraints as a subjects for experimentation, in some cases would be appropriated to include these models as valuable tools to explore host–pathogen interactions. Numerous scientific data have been argued to the more extensive use of several kinds of alternative models, such as, the vertebrate zebrafish (Danio rerio), and non-vertebrate insects and nematodes (e.g., Caenorhabditis elegans) in the study of diverse infectious agents that affect humans. Here, we review the use of these vertebrate and non-vertebrate models in the study of bacterial agents, which are considered the principal causes of lung injury. Curiously none of these animals have a respiratory system as in air-breathing vertebrates, where respiration takes place in lungs. Despite this fact, with the present review we sought to provide elements in favor of the use of these alternative animal models of infection to reveal the molecular signatures of host–pathogen interactions. PMID:25699030

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

    NASA Astrophysics Data System (ADS)

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

    2007-02-01

    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™ 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™ 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 18F 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

  6. The Future of Animals, Cells, Models, and Systems in Research, Development, Education, and Testing: Proceedings of a Symposium.

    ERIC Educational Resources Information Center

    National Academy of Sciences - National Research Council, Washington, DC. Inst. of Lab. Animal Resources.

    This volume contains the prepared papers and discussions of a National Academy of Sciences - National Research Council Symposium on the Future of Animals, Cells, Models, and Systems in Research, Development, Education, and Testing. The purpose of the symposium was to examine the past, present, and future contributions of animals to human health…

  7. [Use of geographical information systems in parasitic diseases and the importance of animal health economics].

    PubMed

    Ciçek, Hasan; Ciçek, Hatice; Senkul, Cetin; Tandoğan, Murat

    2008-01-01

    In the world, economical losses due to the parasitic diseases reach enormous ratios in animal production. Both developed and developing countries set aside a considerable budget to control these parasitic diseases. This situation aids in the improvement of control methods of parasitic diseases. Also, it causes new ways of investigation that includes observation, evaluation and prevention of parasitic diseases. The Geographical Information System (GIS) has recently become one of the most common methods utilized to provide disease information technology with computer supported technology in many countries. The most important qualities of GIS are the formation of a powerful database, continual updating and rapid provision of coordination related to units. Many factors are evaluated at the same time by the system and also, results from analysis of data related to disease and their causes could reduce or prevent economical losses due to parasitic disease. In this study, possible uses of Geographical Information Systems against parasitic diseases and an approach in terms of animal health economics were presented. PMID:18985590

  8. Application study of the optical biopsy system for small experimental animals

    NASA Astrophysics Data System (ADS)

    Sato, Hidetoshi; Suzuki, Toshiaki; Morita, Shin-ichi; Maruyama, Atsushi; Shimosegawa, Toru; Matsuura, Yuji; Kanai, Gen'ichi; Ura, Nobuo; Masutani, Koji; Ozaki, Yukihiro

    2008-02-01

    An optical biopsy system for small experimental animals has been developed. The system includes endoscope probe, portable probe and two kinds of miniaturized Raman probes. The micro Raman probe (MRP) is made of optical fibers and the ball lens hollow optical fiber Raman probe (BHRP) is made of hollow fiber. The former has large focal depth and suitable to measure average spectra of subsurface tissue. The latter has rather small focal depth and it is possible to control focal length by selecting ball lens attached at the probe head. It is suitable to survey materials at the fixed depth in the tissue. The system is applied to study various small animal cancer models, such as esophagus and stomach rat models and subcutaneous mouse models of pancreatic cancers. In the studies of subcutaneous tumor model mouse, it is suggested that protein conformational changes occur in the tumor tissue within few minutes after euthanasia of the mouse. No more change is observed for the following ten minutes. Any alterations in the molecular level are not observed in normal skin, muscle tissues. Since the change completes in such a short time, it is suggested that this phenomenon caused by termination of blood circulation.

  9. Error control in the set-up of stereo camera systems for 3d animal tracking

    NASA Astrophysics Data System (ADS)

    Cavagna, A.; Creato, C.; Del Castello, L.; Giardina, I.; Melillo, S.; Parisi, L.; Viale, M.

    2015-12-01

    Three-dimensional tracking of animal systems is the key to the comprehension of collective behavior. Experimental data collected via a stereo camera system allow the reconstruction of the 3d trajectories of each individual in the group. Trajectories can then be used to compute some quantities of interest to better understand collective motion, such as velocities, distances between individuals and correlation functions. The reliability of the retrieved trajectories is strictly related to the accuracy of the 3d reconstruction. In this paper, we perform a careful analysis of the most significant errors affecting 3d reconstruction, showing how the accuracy depends on the camera system set-up and on the precision of the calibration parameters.

  10. Economic contribution of draught animals to Mazahua smallholder Campesino farming systems in the highlands of Central Mexico.

    PubMed

    Arriaga-Jordán, C M; Pedraza-Fuentes, A M; Velázquez-Beltrán, L G; Nava-Bernal, E G; Chávez-Mejía, M C

    2005-10-01

    The economic contribution of draught animals to smallholder Mazahua campesino systems in two mountain villages of San Felipe del Progreso, in the central highlands of Mexico, was assessed. Campesinos rely on draught animals for cultivation tasks, as pack animals, and as transport for agricultural and domestic activities. The villages were San Pablo Tlalchichilpa (SPT) and La Concepción Mayorazgo (LCM). Twelve households that possessed draught animals were monitored from July 1999 to June 2000, nine in SPT and three in LCM, in terms of animal inventories and income from their draught animals, in cash and opportunity values. Equines in SPT have substituted bulls, and are recognized for their multipurpose contribution, while in LCM bulls are still used for ploughing the land. Overall total mean gross income was US dollar 490.78 per farm per year, plus US dollar 56 as opportunity value of the fertilizer value of manure for both villages. Deducting estimated costs, owning draught animals leaves a mean net margin of US dollar 412.50/year in SPT and of US dollar 285.64/year in LCM. There is a significant correlation (p < 0.05) between ownership of draught animals and incomes, with a regression coefficient of US dollar 279.16 per year per draught animal. Besides positive economic returns, having work animals alleviates drudgery for the campesino families. PMID:16450864

  11. Body Deformation Correction for SPECT Imaging

    PubMed Central

    Gu, Songxiang; McNamara, Joseph E.; Mitra, Joyeeta; Gifford, Howard C.; Johnson, Karen; Gennert, Michael A.; King, Michael A.

    2010-01-01

    Patient motion degrades the quality of SPECT studies. Body bend and twist are types of patient deformation, which may occur during SPECT imaging, and which has been generally ignored in SPECT motion correction strategies. To correct for these types of motion, we propose a deformation model and its inclusion within an iterative reconstruction algorithm. Two experiments were conducted to investigate the applicability of our model. In the first experiment, the return of the postmotion-compensation locations of markers on the body-surface of a volunteer to approximate their original coordinates is used to examine our method of estimating the parameters of our model and the parameters’ use in undoing deformation. The second experiment employed simulated projections of the MCAT phantom formed using an analytical projector which includes attenuation and distance-dependent resolution to investigate applications of our model in reconstruction. We demonstrate in the simulation studies that twist and bend can significantly degrade SPECT image quality visually. Our correction strategy is shown to be able to greatly diminish the degradation seen in the slices, provided the parameters are estimated accurately. We view this work as a first step towards being able to estimate and correct patient deformation based on information obtained from marker tracking data. PMID:20336188

  12. Objective evaluation of reconstruction methods for quantitative SPECT imaging in the absence of ground truth

    PubMed Central

    Jha, Abhinav K.; Song, Na; Caffo, Brian; Frey, Eric C.

    2015-01-01

    Quantitative single-photon emission computed tomography (SPECT) imaging is emerging as an important tool in clinical studies and biomedical research. There is thus a need for optimization and evaluation of systems and algorithms that are being developed for quantitative SPECT imaging. An appropriate objective method to evaluate these systems is by comparing their performance in the end task that is required in quantitative SPECT imaging, such as estimating the mean activity concentration in a volume of interest (VOI) in a patient image. This objective evaluation can be performed if the true value of the estimated parameter is known, i.e. we have a gold standard. However, very rarely is this gold standard known in human studies. Thus, no-gold-standard techniques to optimize and evaluate systems and algorithms in the absence of gold standard are required. In this work, we developed a no-gold-standard technique to objectively evaluate reconstruction methods used in quantitative SPECT when the parameter to be estimated is the mean activity concentration in a VOI. We studied the performance of the technique with realistic simulated image data generated from an object database consisting of five phantom anatomies with all possible combinations of five sets of organ uptakes, where each anatomy consisted of eight different organ VOIs. Results indicate that the method provided accurate ranking of the reconstruction methods. We also demonstrated the application of consistency checks to test the no-gold-standard output. PMID:26430292

  13. Objective evaluation of reconstruction methods for quantitative SPECT imaging in the absence of ground truth

    NASA Astrophysics Data System (ADS)

    Jha, Abhinav K.; Song, Na; Caffo, Brian; Frey, Eric C.

    2015-03-01

    Quantitative single-photon emission computed tomography (SPECT) imaging is emerging as an important tool in clinical studies and biomedical research. There is thus a need for optimization and evaluation of systems and algorithms that are being developed for quantitative SPECT imaging. An appropriate objective method to evaluate these systems is by comparing their performance in the end task that is required in quantitative SPECT imaging, such as estimating the mean activity concentration in a volume of interest (VOI) in a patient image. This objective evaluation can be performed if the true value of the estimated parameter is known, i.e. we have a gold standard. However, very rarely is this gold standard known in human studies. Thus, no-gold-standard techniques to optimize and evaluate systems and algorithms in the absence of gold standard are required. In this work, we developed a no-gold-standard technique to objectively evaluate reconstruction methods used in quantitative SPECT when the parameter to be estimated is the mean activity concentration in a VOI. We studied the performance of the technique with realistic simulated image data generated from an object database consisting of five phantom anatomies with all possible combinations of five sets of organ uptakes, where each anatomy consisted of eight different organ VOIs. Results indicate that the method pro- vided accurate ranking of the reconstruction methods. We also demonstrated the application of consistency checks to test the no-gold-standard output.

  14. Critical windows of exposure for children's health: the reproductive system in animals and humans.

    PubMed Central

    Pryor, J L; Hughes, C; Foster, W; Hales, B F; Robaire, B

    2000-01-01

    Drugs and environmental chemicals can adversely affect the reproductive system. Currently, available data indicate that the consequences of exposure depend on the nature of the chemical, its target, and the timing of exposure relative to critical windows in development of the reproductive system. The reproductive system is designed to produce gametes in far greater excess than would seem to be necessary for the survival of species. Ten to hundreds of millions of spermatozoa are generated daily by most adult male mammals, yet very few of these germ cells succeed in transmitting their genetic material to the next generation. Although the number of oocytes produced in mammalian females is more limited, and their production occurs only during fetal life, most ovaries contain several orders of magnitude more oocytes than ever will be fertilized. Toxicant exposures may affect critical events in the development of the reproductive system, ranging from early primordial germ cell determination to gonadal differentiation, gametogenesis, external genitalia, or signaling events regulating sexual behavior. Although there are differences between the human reproductive system and that of the usual animal models, such models have been extremely useful in assessing risks for key human reproductive and developmental processes. The objectives for future studies should include the elucidation of the specific cellular and molecular targets of known toxicants; the design of a systematic approach to the identification of reproductive toxicants; and the development of sensitive, specific, and predictive animal models, minimally invasive surrogate markers, or in vitro tests to assess reproductive system function during embryonic, postnatal, and adult life. Images Figure 1 Figure 2 PMID:10852849

  15. SPECT studies of brain tumors with L-3-( sup 123 I) iodo-alpha-methyl tyrosine: Comparison with PET, 124IMT and first clinical results

    SciTech Connect

    Langen, K.J.; Coenen, H.H.; Roosen, N.; Kling, P.; Muzik, O.; Herzog, H.; Kuwert, T.; Stoecklin, G.F.; Feinendegen, L.E. )

    1990-03-01

    L-3-({sup 123}I)iodo-alpha-methyltyrosine ({sup 123}IMT) like tyrosine has been reported previously to have a high affinity for a transport system in the blood-brain-barrier (BBB). We examined the kinetic behavior of {sup 124}IMT in brain and plasma in two patients with glioblastoma using dynamic positron emission tomography (PET). {sup 124}IMT accumulated in brain and tumor tissue, reaching a maximum after 15 min, with a washout of 20% to 35% at 60 min postinjection. Animal experiments confirmed the accumulation of the intact tracer in murine brain, but there was no incorporation into proteins. SPECT studies with {sup 123}IMT in patients with different types of brain tumors showed increased uptake in 26 of 32 tumors. Although nonspecific uptake in tumors must be considered, the accumulation of IMT in normal brain and in some tumors with intact BBB suggests a specific uptake of IMT. As transport is the main determinant of initial amino acid uptake, {sup 123}IMT appears to be a suitable SPECT tracer of amino acid uptake although it is not incorporated into protein.

  16. Predator-scent stress, ethanol consumption and the opioid system in an animal model of PTSD.

    PubMed

    Manjoch, Hadar; Vainer, Ella; Matar, Michael; Ifergane, Gal; Zohar, Joseph; Kaplan, Zeev; Cohen, Hagit

    2016-06-01

    Emerging literature points to stress exposure as a potential contributor to the development of alcohol abuse, but animal models have yielded inconsistent results. Converging experimental data indicate that the endogenous opioid system modulates alcohol consumption and stress regulation. The aim of the present study is to examine the interplay between stress exposure, behavioral stress responses, ethanol (EtOH) consumption and the endogenous opioid system in an animal model of posttraumatic stress disorder. Rats were exposed to stress and then tested in a two-bottle free choice (TBC) assay or in a conditioned place preference paradigm. In some experiments, the endogenous opioid system was pharmacologically manipulated prior to stress exposure. The behavioral outcomes of stress exposure were assessed in an elevated plus-maze, with the acoustic startle response, and by monitoring the freezing response to trauma reminder. Immunoreactivity of phosphorylated opioid receptors in hippocampal subregions was also measured. Stress significantly increased the consumption of EtOH in the TBC assay. The severity of the behavioral response to stress was associated with EtOH consumption, cue-triggered freezing response to a trauma reminder, and endogenous levels of phosphorylated opioid receptors in the hippocampus. Pharmacologically manipulating the endogenous opioid system prior to stress exposure attenuated trauma cue-triggered freezing responses and blocked predator scent stress-induced potentiation of EtOH consumption. These data demonstrate a stress-induced potentiation of EtOH self-administration and reveal a clear association between individual patterns of the behavioral response to stress and alcohol preference, while indicating a role for the endogenous opioid system in the neurobiological response to stress. PMID:26965572

  17. Computer-automated silica aerosol generator and animal inhalation exposure system

    PubMed Central

    McKinney, Walter; Chen, Bean; Schwegler-Berry, Diane; Frazer, Dave G.

    2015-01-01

    Inhalation exposure systems are necessary tools for determining the dose response relationship of inhaled toxicants under a variety of exposure conditions. The objective of this study was to develop an automated computer controlled system to expose small laboratory animals to precise concentrations of uniformly dispersed airborne silica particles. An acoustical aerosol generator was developed which was capable of re-suspending particles from bulk powder. The aerosolized silica output from the generator was introduced into the throat of a venturi tube. The turbulent high-velocity air stream within the venturi tube increased the dispersion of the re-suspended powder. That aerosol was then used to expose small laboratory animals to constant aerosol concentrations, up to 20mg/m3, for durations lasting up to 8h. Particle distribution and morphology of the silica aerosol delivered to the exposure chamber were characterized to verify that a fully dispersed and respirable aerosol was being produced. The inhalation exposure system utilized a combination of airflow controllers, particle monitors, data acquisition devices and custom software with automatic feedback control to achieve constant and repeatable exposure environments. The automatic control algorithm was capable of maintaining median aerosol concentrations to within ±0.2 mg/m3 of a user selected target concentration during exposures lasting from 2 to 8 h. The system was able to reach 95% of the desired target value in <10min during the beginning phase of an exposure. This exposure system provided a highly automated tool for conducting inhalation toxicology studies involving silica particles. PMID:23796015

  18. Development of a Salmonella cross-protective vaccine for food animal production systems.

    PubMed

    Heithoff, Douglas M; House, John K; Thomson, Peter C; Mahan, Michael J

    2015-01-01

    Intensive livestock production is associated with increased Salmonella exposure, transmission, animal disease, and contamination of food and water supplies. Modified live Salmonella enterica vaccines that lack a functional DNA adenine methylase (Dam) confer cross-protection to a diversity of salmonellae in experimental models of murine, avian, ovine, and bovine models of salmonellosis. However, the commercial success of any vaccine is dependent upon the therapeutic index, the ratio of safety/efficacy. Herein, secondary virulence-attenuating mutations targeted to genes involved in intracellular and/or systemic survival were introduced into Salmonella dam vaccines to screen for vaccine candidates that were safe in the animal and the environment, while maintaining the capacity to confer cross-protective immunity to pathogenic salmonellae serotypes. Salmonella dam mgtC, dam sifA, and dam spvB vaccine strains exhibited significantly improved vaccine safety as evidenced by the failure to give rise to virulent revertants during the infective process, contrary to the parental Salmonella dam vaccine. Further, these vaccines exhibited a low grade persistence in host tissues that was associated with reduced vaccine shedding, reduced environmental persistence, and induction of cross-protective immunity to pathogenic serotypes derived from infected livestock. These data indicate that Salmonella dam double mutant vaccines are suitable for commercial applications against salmonellosis in livestock production systems. Reducing pre-harvest salmonellae load through vaccination will promote the health and productivity of livestock and reduce contamination of livestock-derived food products, while enhancing overall food safety. PMID:25448106

  19. A comparative study of production performance and animal health practices in organic and conventional dairy systems.

    PubMed

    Silva, Jenevaldo B; Fagundes, Gisele M; Soares, João P G; Fonseca, Adivaldo H; Muir, James P

    2014-10-01

    Health and production management strategies influence environmental impacts of dairies. The objective of this paper was to measure risk factors on health and production parameters on six organic and conventional bovine, caprine, and ovine dairy herds in southeastern Brazil over six consecutive years (2006-2011). The organic operations had lower milk production per animal (P ≤ 0.05), lower calf mortality (P ≤ 0.05), less incidence of mastitis (P ≤ 0.05), fewer rates of spontaneous abortions (P ≤ 0.05), and reduced ectoparasite loads (P ≤ 0.05) compared to conventional herds and flocks. Organic herds, however, had greater prevalence of internal parasitism (P ≤ 0.05) than conventional herds. In all management systems, calves, kids, and lambs had greater oocyte counts than adults. However, calves in the organic group showed lower prevalence of coccidiosis. In addition, animals in the organic system exhibited lower parasitic resistance to anthelmintics. Herd genetic potential, nutritive value of forage, feed intake, and pasture parasite loads, however, may have influenced productive and health parameters. Thus, although conventional herds showed greater milk production and less disease prevalence, future research might quantify the potential implications of these unreported factors. PMID:25015183

  20. A wireless neural recording system with a precision motorized microdrive for freely behaving animals

    PubMed Central

    Hasegawa, Taku; Fujimoto, Hisataka; Tashiro, Koichiro; Nonomura, Mayu; Tsuchiya, Akira; Watanabe, Dai

    2015-01-01

    The brain is composed of many different types of neurons. Therefore, analysis of brain activity with single-cell resolution could provide fundamental insights into brain mechanisms. However, the electrical signal of an individual neuron is very small, and precise isolation of single neuronal activity from moving subjects is still challenging. To measure single-unit signals in actively behaving states, establishment of technologies that enable fine control of electrode positioning and strict spike sorting is essential. To further apply such a single-cell recording approach to small brain areas in naturally behaving animals in large spaces or during social interaction, we developed a compact wireless recording system with a motorized microdrive. Wireless control of electrode placement facilitates the exploration of single neuronal activity without affecting animal behaviors. Because the system is equipped with a newly developed data-encoding program, the recorded data are readily compressed almost to theoretical limits and securely transmitted to a host computer. Brain activity can thereby be stably monitored in real time and further analyzed using online or offline spike sorting. Our wireless recording approach using a precision motorized microdrive will become a powerful tool for studying brain mechanisms underlying natural or social behaviors. PMID:25597933

  1. The magnetic shielding for the neutron decay spectrometer aSPECT

    NASA Astrophysics Data System (ADS)

    Konrad, Gertrud; Ayala Guardia, Fidel; Baeßler, Stefan; Borg, Michael; Glück, Ferenc; Heil, Werner; Hiebel, Stefan; Muñoz Horta, Raquel; Sobolev, Yury

    2014-12-01

    Many experiments in nuclear and neutron physics are confronted with the problem that they use a superconducting magnetic spectrometer which potentially affects other experiments by their stray magnetic field. The retardation spectrometer aSPECT consists, inter alia, of a superconducting magnet system that produces a strong longitudinal magnetic field of up to 6.2 T. In order not to disturb other experiments in the vicinity of aSPECT, we had to develop a magnetic field return yoke for the magnet system. While the return yoke must reduce the stray magnetic field, the internal magnetic field and its homogeneity should not be affected. As in many cases, the magnetic shielding for aSPECT must manage with limited space. In addition, we must ensure that the additional magnetic forces on the magnet coils are not destructive. In order to determine the most suitable geometry for the magnetic shielding for aSPECT, we simulated a variety of possible geometries and combinations of shielding materials of non-linear permeability. The results of our simulations were checked through magnetic field measurements both with Hall and nuclear magnetic resonance probes. The experimental data are in good agreement with the simulated values: the mean deviation from the simulated exterior magnetic field is (-1.7±4.8)%. However, in the two critical regions, the internal magnetic field deviates by 0.2% (decay volume) and < 1 ×10-4 (analyzing plane) from the simulated values.

  2. A chamber system for maintaining a hyperbaric environment for long-term animal studies.

    PubMed

    Pearce, P C; Ross, J A; Luff, N P; Halsey, M J; Monk, S

    1991-01-01

    An experimental hyperbaric chamber system is described whereby animals, including nonhuman primates, can be cared for under altered environmental conditions for periods in excess of 1 wk. The chamber itself is capable of a working pressure of 200 atm abs, used with various mixtures of gases which can be varied independently. The novel approach of vertical mounting enables cages to be lowered into position, and food and water can be supplied from above while excreta can be removed from below, irrespective of the internal pressure. The chamber has an integrated life support system such that temperature, both of the chamber and of the mass of gas inside, humidity, oxygen, carbon dioxide, and noise levels can be accurately and finely controlled, all within a pathogen-free environment. PMID:2021021

  3. Whole-body three-dimensional optoacoustic tomography system for small animals

    PubMed Central

    Brecht, Hans-Peter; Su, Richard; Fronheiser, Matthew; Ermilov, Sergey A.; Conjusteau, Andre; Oraevsky, Alexander A.

    2009-01-01

    We develop a system for three-dimensional whole-body optoacoustic tomography of small animals for applications in preclinical research. The tomographic images are obtained while the objects of study (phantoms or mice) are rotated within a sphere outlined by a concave arc-shaped array of 64 piezocomposite transducers. Two pulsed lasers operating in the near-IR spectral range (755 and 1064 nm) with an average pulsed energy of about 100 mJ, a repetition rate of 10 Hz, and a pulse duration of 15 to 75 ns are used as optical illumination sources. During the scan, the mouse is illuminated orthogonally to the array with two wide beams of light from a bifurcated fiber bundle. The system is capable of generating images of individual organs and blood vessels through the entire body of a mouse with spatial resolution of ∼0.5 mm. PMID:20059245

  4. Computer animation for minimally invasive surgery: computer system requirements and preferred implementations

    NASA Astrophysics Data System (ADS)

    Pieper, Steven D.; McKenna, Michael; Chen, David; McDowall, Ian E.

    1994-04-01

    We are interested in the application of computer animation to surgery. Our current project, a navigation and visualization tool for knee arthroscopy, relies on real-time computer graphics and the human interface technologies associated with virtual reality. We believe that this new combination of techniques will lead to improved surgical outcomes and decreased health care costs. To meet these expectations in the medical field, the system must be safe, usable, and cost-effective. In this paper, we outline some of the most important hardware and software specifications in the areas of video input and output, spatial tracking, stereoscopic displays, computer graphics models and libraries, mass storage and network interfaces, and operating systems. Since this is a fairly new combination of technologies and a new application, our justification for our specifications are drawn from the current generation of surgical technology and by analogy to other fields where virtual reality technology has been more extensively applied and studied.

  5. Asymmetrical-fan tranmission CT on SPECT to derive {mu}-maps for attenuation correction

    SciTech Connect

    Loncaric, S.; Huang, G.; Ni, B.

    1994-05-01

    For proper attenuation correction of SPECT images, an appropriate {mu}-map properly registered with each imaging slices is needed. Among the many techniques for {mu}-map derivation, simultaneous or sequential fan-beam transmission CT (TCT), on the same SPECT system with the same acquisition settings, have advantages of being practical while ensuring registration. However, the problems are: (1) limited FOV for thoracic imaging, projection would be truncated with a typical size detector, (2) lack of room for placing the transmission source in many SPECT systems. We have developed a new sampling scheme to solve the problems mentioned above. This scheme uses an asymmetrical-fan geometry (AFG), which samples only half of the field, the other half would be sampled after an 180{degrees} detector rotation. This technique completes the minimum sampling requirement in a 360{degrees} detector rotation and yields a relatively large FOV defined by the outside edge of the sampling fan. We have confirmed the feasibility of the AFG sampling on a 3-head SPECT system to provide a large FOV for TCT of most patient. The TCT sampling scheme is achieved with an asymmetrical-fan collimator. We have developed the required new reconstruction algorithms and derived excellent reconstructed images of phantoms and human subjects. We propose to have this technique implemented in a short and fast transmission scan in a multi-head SPECT system, after emission imaging, because the detectors have to be pulled out to make room for the transmission source. The imaging field can even exceed the full field size of the detector. MS would be possible when an obtuse sampling fan is formed by shifting the source outward further, provided the central FOV is properly covered with a supplementary sampling scheme, e.g., using another TCT with a fan-beam collimator on another one of the detectors.

  6. Evaluation of individually ventilated cage systems for laboratory rodents: cage environment and animal health aspects.

    PubMed

    Höglund, A U; Renström, A

    2001-01-01

    The use of individually ventilated cage (IVC) systems has become an attractive housing regime of laboratory rodents. The benefits of IVC systems are, reportedly, a high degree of containment combined with relative ease of handling, and a high degree of protection from allergenes. In the present study we tested whether two IVC systems (BioZone VentiRack, IVC1 and Techniplast SealSafe, IVC2S), in which we held mature male NMRI mice, were constructed to maintain a constant differential pressure, positive or negative, during a prolonged period of time. We also measured ammonia (NH3) concentrations after about 2 weeks of use, and CO2 build-up during a 60 min simulated power failure situation. In addition, animal weight development and bite-wound frequency were recorded (Renström et al. 2000). From the present study it is concluded that the IVC1 air handling system provides a more uniform and balanced differential pressure than the IVC2S. Both systems effectively scavenge NH3 when bedding material is not soaked by urine. Although the IVCs are dependent on the continual function of the fans to work properly, it seems unlikely that CO2 concentrations increase to hazardous levels, as a result of a one hour power failure, with the type of cages used in this study. Differences in weight development and bite-wound occurrence were noted between the two IVC systems. Causes for these differences could not be established and need more investigation. PMID:11201288

  7. A microcomputed tomography guided fluorescence tomography system for small animal molecular imaging

    NASA Astrophysics Data System (ADS)

    Kepshire, Dax; Mincu, Niculae; Hutchins, Michael; Gruber, Josiah; Dehghani, Hamid; Hypnarowski, Justin; Leblond, Frederic; Khayat, Mario; Pogue, Brian W.

    2009-04-01

    A prototype small animal imaging system was created for coupling fluorescence tomography (FT) with x-ray microcomputed tomography (microCT). The FT system has the potential to provide synergistic information content resultant from using microCT images as prior spatial information and then allows overlay of the FT image onto the original microCT image. The FT system was designed to use single photon counting to provide maximal sensitivity measurements in a noncontact geometry. Five parallel detector locations are used, each allowing simultaneous sampling of the fluorescence and transmitted excitation signals through the tissue. The calibration and linearity range performance of the system are outlined in a series of basic performance tests and phantom studies. The ability to image protoporphyrin IX in mouse phantoms was assessed and the system is ready for in vivo use to study biological production of this endogenous marker of tumors. This multimodality imaging system will have a wide range of applications in preclinical cancer research ranging from studies of the tumor microenvironment and treatment efficacy for emerging cancer therapeutics.

  8. A microcomputed tomography guided fluorescence tomography system for small animal molecular imaging

    SciTech Connect

    Kepshire, Dax; Gruber, Josiah; Hypnarowski, Justin; Leblond, Frederic; Pogue, Brian W.; Mincu, Niculae; Hutchins, Michael; Khayat, Mario; Dehghani, Hamid

    2009-04-15

    A prototype small animal imaging system was created for coupling fluorescence tomography (FT) with x-ray microcomputed tomography (microCT). The FT system has the potential to provide synergistic information content resultant from using microCT images as prior spatial information and then allows overlay of the FT image onto the original microCT image. The FT system was designed to use single photon counting to provide maximal sensitivity measurements in a noncontact geometry. Five parallel detector locations are used, each allowing simultaneous sampling of the fluorescence and transmitted excitation signals through the tissue. The calibration and linearity range performance of the system are outlined in a series of basic performance tests and phantom studies. The ability to image protoporphyrin IX in mouse phantoms was assessed and the system is ready for in vivo use to study biological production of this endogenous marker of tumors. This multimodality imaging system will have a wide range of applications in preclinical cancer research ranging from studies of the tumor microenvironment and treatment efficacy for emerging cancer therapeutics.

  9. An infrared motion detector system for lossless real-time monitoring of animal preference tests.

    PubMed

    Pogány, A; Heszberger, J; Szurovecz, Zita; Vincze, E; Székely, T

    2014-12-01

    Automated behavioural observations are routinely used in many fields of biology, including ethology, behavioural ecology and physiology. When preferences for certain resources are investigated, the focus is often on simple response variables, such as duration and frequency of visits to choice chambers. Here we present an automated motion detector system that use passive infrared sensors to eliminate many drawbacks of currently existing methods. Signals from the sensors are processed by a custom-built interface, and after unnecessary data is filtered by a computer software, the total time and frequency of the subject's visits to each of the choice chambers are calculated. We validate the detector system by monitoring (using the system) and in the same time video recording mating preferences of zebra finches in a four-way choice apparatus. Manual scoring of the video recordings showed very high consistency with data from the detector system both for time and for frequency of visits. Furthermore, the validation revealed that if we used micro-switches or light barriers, the most commonly applied automatic detection techniques, this would have resulted in approximately 22% less information compared to our lossless system. The system provides a low-cost alternative for monitoring animal movements, and we discuss its further applicability. PMID:25475978

  10. SU-E-I-20: Dead Time Count Loss Compensation in SPECT/CT: Projection Versus Global Correction

    SciTech Connect

    Siman, W; Kappadath, S

    2014-06-01

    Purpose: To compare projection-based versus global correction that compensate for deadtime count loss in SPECT/CT images. Methods: SPECT/CT images of an IEC phantom (2.3GBq 99mTc) with ∼10% deadtime loss containing the 37mm (uptake 3), 28 and 22mm (uptake 6) spheres were acquired using a 2 detector SPECT/CT system with 64 projections/detector and 15 s/projection. The deadtime, Ti and the true count rate, Ni at each projection, i was calculated using the monitor-source method. Deadtime corrected SPECT were reconstructed twice: (1) with projections that were individually-corrected for deadtime-losses; and (2) with original projections with losses and then correcting the reconstructed SPECT images using a scaling factor equal to the inverse of the average fractional loss for 5 projections/detector. For both cases, the SPECT images were reconstructed using OSEM with attenuation and scatter corrections. The two SPECT datasets were assessed by comparing line profiles in xyplane and z-axis, evaluating the count recoveries, and comparing ROI statistics. Higher deadtime losses (up to 50%) were also simulated to the individually corrected projections by multiplying each projection i by exp(-a*Ni*Ti), where a is a scalar. Additionally, deadtime corrections in phantoms with different geometries and deadtime losses were also explored. The same two correction methods were carried for all these data sets. Results: Averaging the deadtime losses in 5 projections/detector suffices to recover >99% of the loss counts in most clinical cases. The line profiles (xyplane and z-axis) and the statistics in the ROIs drawn in the SPECT images corrected using both methods showed agreement within the statistical noise. The count-loss recoveries in the two methods also agree within >99%. Conclusion: The projection-based and the global correction yield visually indistinguishable SPECT images. The global correction based on sparse sampling of projections losses allows for accurate SPECT deadtime

  11. [A new system using NMR technology for measurement of body composition in experimental animals].

    PubMed

    Suzuki, Jun; Furutoh, Kenichi; Nishikibe, Masaru

    2004-04-01

    Measurement of body composition (fat mass) is an important item in pathophysiological and pharmacological studies using small animals (mice) in the fields of obesity and diabetes. The existing methods are, however, difficult, time consuming, and require a shielding facility. Now a novel system using nuclear magnetic resonance (NMR) technique was developed for measurement of body composition in small animals (mice) that provides noninvasive and rapid measurement without anesthetics; we introduced and evaluated this system and tried another application of this system. First, we validated this system using canola oil, soft tissues (adipose and skeletal muscle), and various kinds of rodent chows. Accuracy, precision, and reproducibility of this system were demonstrated to be equal to those in standard chemical methods. A strong positive correlation (y=x) between the results of NMR and chemical methods was found. Secondly, we evaluated accuracy and assay range of the NMR method using live mice that were fasted overnight or fed high fat diet (HFD). In fasted mice, a small but quantitative decrease of fat mass (5.1% from 9.1%) was detected. Total decrease of fat and lean mass (5.0 g) in fasted mice was equivalent to the decrease of body weight (5.0 g). In mice fed the HFD, increase of fat mass with relative decrease of lean mass were qualitatively detected in a time-dependent manner. We would like to emphasize that operation of the system was actually easy and measurements were accomplished in a short time (1 minute). Thirdly, we tried to use the NMR system for determination of hepatic fat contents using mice fasted or treated with a PPARgamma agonist; our results showed a quantitative increase in fat by fasting or in decrease in fat by the drug treatment. The changes of fat contents determined by the NMR method were well correlated with the changes in triglyceride and total cholesterol values obtained by the biochemical assays. In conclusion, body composition data

  12. [The organization of veterinary services in African animal husbandry systems: chances for the exchange of interdisciplinary learning processes].

    PubMed

    Kirk, M

    1995-12-01

    The structure of the veterinary services to date hinders--together with massive intervention in the land tenure systems and the animal keepers' rights in arid and semi-arid areas--the future organization of productive animal-keeping systems adapted to the ecological conditions. The consensus of the findings of research in the social as well as in the natural sciences, is that state (agrarian) policies and international development cooperation have led to centralism and authoritarian administrations which formalize formerly informal, locally specific rules for securing the health of the animals and the maintenance of grazing and water resources. As a result, the animal-keeping groups have lost their rights, social conflicts arose and the environment suffered. Thus, decentralization, subsidarity and--above all--comprehensive participation on the part of the animal keepers are regarded as the guidelines for the future organization of state and/or private services for maintaining the health of the animals. Thereby, the planning at the various administrative levels is faced by great challenges in view of the progressing differentiation in the animal-keeping systems (e.g. peri-urban systems; urban absentee herd owners; marginalized, subsistence-oriented households). PMID:8651895

  13. Education System Using Interactive 3D Computer Graphics (3D-CG) Animation and Scenario Language for Teaching Materials

    ERIC Educational Resources Information Center

    Matsuda, Hiroshi; Shindo, Yoshiaki

    2006-01-01

    The 3D computer graphics (3D-CG) animation using a virtual actor's speaking is very effective as an educational medium. But it takes a long time to produce a 3D-CG animation. To reduce the cost of producing 3D-CG educational contents and improve the capability of the education system, we have developed a new education system using Virtual Actor.…

  14. Eastern Europe and the former Union of Soviet Socialist Republics: animal health systems in transition.

    PubMed

    Schillhorn van Veen, T W

    2004-04-01

    The economic transition in Eastern Europe and the former Union of Soviet Socialist Republics (USSR) during the last decade has profoundly changed the agricultural sector and the well-being of people in rural areas. Farm ownership changed; selected farm assets, including livestock, were transferred to farm workers or others, and the social and service structures of rural society are in a state of uncertainty. The transition has, in general, led to the deterioration of rural services. Animal health services have also deteriorated. This decline is associated with the contraction of the livestock inventory, the fragmentation of farms, higher transaction costs for service providers, and the overall decline of the rural economy which has, so far, lowered the demand for animal health services. There are considerable differences in the way that these countries are coping with the economic transition and its aftermath. Among the determining factors in the former USSR are, as follows: the speed of recovery from the legacies of large State-controlled farming and a centrally planned animal health system, the efforts made to address poverty reduction, the choice on whether to become a Member of the World Trade Organization and the requirements of such membership, the ability to provide low-cost services to a fragmented and unskilled livestock production sector. In Eastern Europe, the requirements for joining the European Union (EU) are an additional and important determining factor. In the short term, the choice of a veterinary system to serve the livestock sector may differ from country to country, depending on the legacies of the past, the status of reforms and the proximity of Western markets. Lower-income countries with an oversupply of veterinarians may support labour-intensive, low-cost systems which focus on food security and public health. The better-endowed EU accession countries may focus rather on improved disease surveillance, production enhancement, quality

  15. Passive immunisation, an old idea revisited: Basic principles and application to modern animal production systems.

    PubMed

    Hedegaard, Chris J; Heegaard, Peter M H

    2016-06-01

    Immunisation by administration of antibodies (immunoglobulins) has been known for more than one hundred years as a very efficient means of obtaining immediate, short-lived protection against infection and/or against the disease-causing effects of toxins from microbial pathogens and from other sources. Thus, due to its rapid action, passive immunisation is often used to treat disease caused by infection and/or toxin exposure. However immunoglobulins may also be administered prior to exposure to infection and/or toxin, although they will not provide long-lasting protection as is seen with active immunisation (vaccination) in which an immunological memory is established by controlled exposure of the host to the pathogen in question. With multi-factorial infectious diseases in production animals, especially those that have proven hard to control by vaccination, the potential of passive immunisation remains big. This review highlights a number of examples on the use of passive immunisation for the control of infectious disease in the modern production of a range of animals, including pigs, cattle, sheep, goat, poultry and fish. Special emphasis is given on the enablement of passive immunisation strategies in these production systems through low cost and ease of use as well as on the sources, composition and purity of immunoglobulin preparations used and their benefits as compared to current measures, including vaccination (also comprising maternal vaccination), antibiotics and feed additives such as spray-dried plasma. It is concluded that provided highly efficient, relatively low-price immunoglobulin products are available, passive immunisation has a clear role in the modern animal production sector as a means of controlling infectious diseases, importantly with a very low risk of causing development of bacterial resistance, thus constituting a real and widely applicable alternative to antibiotics. PMID:27185263

  16. Can disordered radical pair systems provide a basis for a magnetic compass in animals?

    PubMed Central

    Hill, Erin; Ritz, Thorsten

    2010-01-01

    A proposed mechanism for magnetic compasses in animals is that systems of radical pairs transduce magnetic field information to the nervous system. One can show that perfectly ordered arrays of radical pairs are sensitive to the direction of the external magnetic field and can thus operate, in principle, as a magnetic compass. Here, we investigate how disorder, inherent in biological cells, affects the ability of radical pair systems to provide directional information. We consider biologically inspired geometrical arrangements of ensembles of radical pairs with increasing amounts of disorder and calculate the effect of changing the direction of the external magnetic field on the rate of chemical signal production by radical pair systems. Using a previously established signal transduction model, we estimate the minimum number of receptors necessary to allow for detection of the change in chemical signal owing to changes in magnetic field direction. We quantify the required increase in the number of receptors to compensate for the signal attenuation through increased disorder. We find radical-pair-based compass systems to be relatively robust against disorder, suggesting several scenarios as to how a compass structure can be realized in a biological cell. PMID:19906676

  17. Wireless Neural/EMG Telemetry Systems for Small Freely Moving Animals.

    PubMed

    Harrison, R R; Fotowat, H; Chan, R; Kier, R J; Olberg, R; Leonardo, A; Gabbiani, F

    2011-04-01

    We have developed miniature telemetry systems that capture neural, EMG, and acceleration signals from a freely moving insect or other small animal and transmit the data wirelessly to a remote digital receiver. The systems are based on custom low-power integrated circuits (ICs) that amplify, filter, and digitize four biopotential signals using low-noise circuits. One of the chips also digitizes three acceleration signals from an off-chip microelectromechanical-system accelerometer. All information is transmitted over a wireless ~ 900-MHz telemetry link. The first unit, using a custom chip fabricated in a 0.6- μm BiCMOS process, weighs 0.79 g and runs for two hours on two small batteries. We have used this system to monitor neural and EMG signals in jumping and flying locusts as well as transdermal potentials in weakly swimming electric fish. The second unit, using a custom chip fabricated in a 0.35-μ m complementary metal-oxide semiconductor CMOS process, weighs 0.17 g and runs for five hours on a single 1.5-V battery. This system has been used to monitor neural potentials in untethered perching dragonflies. PMID:23851198

  18. Development of A General Principle Solution Forisoagrinet Compliant Networking System Components in Animal Husbandry

    NASA Astrophysics Data System (ADS)

    Kuhlmann, Arne; Herd, Daniel; Röβler, Benjamin; Gallmann, Eva; Jungbluth, Thomas

    In pig production software and electronic systems are widely used for process control and management. Unfortunately most devices on farms are proprietary solutions and autonomically working. To unify data communication of devices in agricultural husbandry, the international standard ISOagriNET (ISO 17532:2007) was developed. It defines data formats and exchange protocols, to link up devices like climate controls, feeding systems and sensors, but also management software. The aim of the research project, "Information and Data Collection in Livestock Systems" is to develop an ISOagriNET compliant IT system, a so called Farming Cell. It integrates all electronic components to acquire the available data and information for pig fattening. That way, an additional benefit to humans, animals and the environment regarding process control and documentation, can be generated. Developing the Farming Cell is very complex; in detail it is very difficult and long-winded to integrate hardware and software by various vendors into an ISOagriNET compliant IT system. This ISOagriNET prototype shows as a test environment the potential of this new standard.

  19. SPECT in Alzheimer`s disease and the dementias

    SciTech Connect

    Bonte, F.J.

    1991-12-31

    Among 90 patients with a clinical diagnosis of Alzheimer`s disease (AD), two subgroups were identified for special study, including 42 patients who had a history of dementia in one or more first-degree relatives, and 14 who had a diagnosis of early AD. Of the 42 patients with a family history of dementia, 34 out of the 35 patients whose final clinical diagnosis was possible or probable AD had positive SPECT rCBF studies. Studies in the 14 patients thought to have very early AD were positive in 11 cases. This finding suggests that altered cortical physiology, and hence, rCBF, occurs quite early in the course of AD, perhaps before the onset of symptoms. It is possible that Xenon 133 rCBF studies might be used to detect the presence of subclinical AD in a population of individuals at risk to this disorder. Despite the drawbacks of a radionuclide with poor photon energy, Xenon 133, with its low cost and round-the-clock availability, deserves further study. Although the physical characteristics of Xenon 127 might make it preferable as a SPECT tracer, it is still not regularly available, and some instrument systems are not designed to handle its higher photon energies.

  20. Development of PET and SPECT Probes for Glutamate Receptors

    PubMed Central

    Nakayama, Morio

    2015-01-01

    l-Glutamate and its receptors (GluRs) play a key role in excitatory neurotransmission within the mammalian central nervous system (CNS). Impaired regulation of GluRs has also been implicated in various neurological disorders. GluRs are classified into two major groups: ionotropic GluRs (iGluRs), which are ligand-gated ion channels, and metabotropic GluRs (mGluRs), which are coupled to heterotrimeric guanosine nucleotide binding proteins (G-proteins). Positron emission tomography (PET) and single photon emission computed tomography (SPECT) imaging of GluRs could provide a novel view of CNS function and of a range of brain disorders, potentially leading to the development of new drug therapies. Although no satisfactory imaging agents have yet been developed for iGluRs, several PET ligands for mGluRs have been successfully employed in clinical studies. This paper reviews current progress towards the development of PET and SPECT probes for GluRs. PMID:25874256

  1. An interactive computer-animated system (SpiroGame) facilitates spirometry in preschool children.

    PubMed

    Vilozni, D; Barker, M; Jellouschek, H; Heimann, G; Blau, H

    2001-12-15

    Although airway disease in preschool children is common, standard spirometry is limited by the level of cooperation. We evaluated a computer-animated system (SpiroGame) aimed at improving children's performance in spirometry. SpiroGame includes a commercial pneumotachograph (ZAN100; ZAN Messgeraete GmbH, Oberthulba, Germany) and games teaching tidal breathing and all steps of an FVC maneuver. SpiroGame was compared with commercial flow-targeted candle-blowing software (MasterLab, Jaeger, Germany), and with extrapolated predicted values. Of 112 children aged 3 to 6 yr, 10 refused spirometry and 102 proceeded to FVC games and were randomized to initially perform either SpiroGame or candle-blowing. Training lasted 5 to 10 min for SpiroGame and 3 to 7 min for candle-blowing. Acceptable spirometry was performed by 69 of 102 children with SpiroGame and 48 of 102 with candle-blowing (p = 0.005). Order did not affect success. Acceptable FEV(1) maneuvers were achieved by 55 children with SpiroGame and two children with candle-blowing. The intrasubject coefficient of variation was 4.0% for FVC and 3.3% for FEV(1) with SpiroGame. A premature expiratory break occurred in 41 subjects with candle-blowing and in six with SpiroGame. FEV(0.5) could be measured with both systems. FVC and maximal midexpiratory flow at 50% of FVC (MMEF(50)) values were similar, whereas peak expiratory flow was higher with candle-blowing. In 39 healthy children, most parameters with SpiroGame were similar to extrapolated normal values. We conclude that an interactive computer-animated system facilitates successful spirometry in preschool children. PMID:11751188

  2. The Pig PeptideAtlas: A resource for systems biology in animal production and biomedicine.

    PubMed

    Hesselager, Marianne O; Codrea, Marius C; Sun, Zhi; Deutsch, Eric W; Bennike, Tue B; Stensballe, Allan; Bundgaard, Louise; Moritz, Robert L; Bendixen, Emøke

    2016-02-01

    Biological research of Sus scrofa, the domestic pig, is of immediate relevance for food production sciences, and for developing pig as a model organism for human biomedical research. Publicly available data repositories play a fundamental role for all biological sciences, and protein data repositories are in particular essential for the successful development of new proteomic methods. Cumulative proteome data repositories, including the PeptideAtlas, provide the means for targeted proteomics, system-wide observations, and cross-species observational studies, but pigs have so far been underrepresented in existing repositories. We here present a significantly improved build of the Pig PeptideAtlas, which includes pig proteome data from 25 tissues and three body fluid types mapped to 7139 canonical proteins. The content of the Pig PeptideAtlas reflects actively ongoing research within the veterinary proteomics domain, and this article demonstrates how the expression of isoform-unique peptides can be observed across distinct tissues and body fluids. The Pig PeptideAtlas is a unique resource for use in animal proteome research, particularly biomarker discovery and for preliminary design of SRM assays, which are equally important for progress in research that supports farm animal production and veterinary health, as for developing pig models with relevance to human health research. PMID:26699206

  3. The Pig PeptideAtlas: a resource for systems biology in animal production and biomedicine

    PubMed Central

    Hesselager, Marianne O.; Codrea, Marius C.; Sun, Zhi; Deutsch, Eric W.; Bennike, Tue B.; Stensballe, Allan; Bundgaard, Louise; Moritz, Robert L.; Bendixen, Emøke

    2016-01-01

    Biological research of Sus scrofa, the domestic pig, is of immediate relevance for food production sciences, and for developing pig as a model organism for human biomedical research. Publicly available data repositories play a fundamental role for all biological sciences, and protein data repositories are in particular essential for the successful development of new proteomic methods. Cumulative proteome data repositories, including the PeptideAtlas, provide the means for targeted proteomics, system wide observations, and cross species observational studies, but pigs have so far been underrepresented in existing repositories. We here present a significantly improved build of the Pig PeptideAtlas, which includes pig proteome data from 25 tissues and three body fluid types mapped to 7139 canonical proteins. The content of the Pig PeptideAtlas reflects actively ongoing research within the veterinary proteomics domain, and this manuscript demonstrates how the expression of isoform-unique peptides can be observed across distinct tissues and body fluids. The Pig PeptideAtlas is a unique resource for use in animal proteome research, particularly biomarker discovery and for preliminary design of SRM assays, which are equally important for progress in research that supports farm animal production and veterinary health, as for developing pig models with relevance to human health research. PMID:26699206

  4. Digital restoration of indium-111 and iodine-123 SPECT images with optimized Metz filters

    SciTech Connect

    King, M.A.; Schwinger, R.B.; Penney, B.C.; Doherty, P.W.; Bianco, J.A.

    1986-08-01

    A number of radiopharmaceuticals of great current clinical interest for imaging are labeled with radionuclides that emit medium- to high-energy photons either as their primary radiation, or in low abundance in addition to their primary radiation. The imaging characteristics of these radionuclides result in gamma camera image quality that is inferior to that of /sup 99m/Tc images. Thus, in this investigation /sup 111/In and /sup 123/I contaminated with approximately 4% /sup 124/I were chosen to test the hypothesis that a dramatic improvement in planar and SPECT images may be obtainable with digital image restoration. The count-dependent Metz filter is shown to be able to deconvolve the rapid drop at low spatial frequencies in the imaging system modulation transfer function (MTF) resulting from the acceptance of septal penetration and scatter in the camera window. Use of the Metz filter was found to result in improved spatial resolution as measured by both the full width at half maximum and full width at tenth maximum for both planar and SPECT studies. Two-dimensional, prereconstruction filtering with optimized Metz filters was also determined to improve image contrast, while decreasing the noise level for SPECT studies. A dramatic improvement in image quality was observed with the clinical application of this filter to SPECT imaging.

  5. The use of spect/ct in the evaluation of heterotopic ossification in para/tetraplegics

    PubMed Central

    Lima, Maurício Coelho; Passarelli, Marcus Ceregati; Dario, Virgílio; Lebani, Bruno Rodrigues; Monteiro, Paulo Henrique Silva; Ramos, Celso Darío

    2014-01-01

    Objective: To evaluate the stage of maturation and the metabolism of neurogenic heterotopic ossification by using SPECT/CT. Methods: A total of 12 medical records of patients with spinal cord injury, all of them classified according to the ASIA protocol (disability scale from the American Spinal Injury Association) in complete lesion (A) and partial lesions (B, C and D) and registered at the Laboratory of Biomechanics and Rehabilitation of the Locomotor System, were submitted to SPECT/CT evaluation. Results: Sixteen hips with heterotopic ossification observed in X-ray were studied and only two (12.5%) had high osteoblastic activity. Five hips showed medium activity, three (18.75%) low activity and six (37.5%) did not present any activity detected by SPECT/CT. Conclusion: SPECT/CT helps to determinate which patients have a greater risk of relapse after surgical resection, proving to be a useful imaging study in preoperative evaluation that can be used to determinate the postoperative prognosis of these patients. Level of Evidence III, Investigating a Diagnostic Test. PMID:24644413

  6. Small Animal Radionuclide Imaging With Focusing Gamma-Ray Optics

    SciTech Connect

    Hill, R; Decker, T; Epstein, M; Ziock, K; Pivovaroff, M J; Craig, W W; Jernigan, J G; Barber, W B; Christensen, F E; Funk, T; Hailey, C J; Hasegawa, B H; Taylor, C

    2004-02-27

    Significant effort currently is being devoted to the development of noninvasive imaging systems that allow in vivo assessment of biological and biomolecular interactions in mice and other small animals. While physiological function in small animals can be localized and imaged using conventional radionuclide imaging techniques such as single-photon emission tomography (SPECT) and positron emission tomography (PET), these techniques inherently are limited to spatial resolutions of 1-2 mm. For this reason, we are developing a small animal radionuclide imaging system (SARIS) using grazing incidence optics to focus gamma-rays emitted by {sup 125}I and other radiopharmaceuticals. We have developed a prototype optic with sufficient accuracy and precision to focus the 27.5 keV photons from {sup 125}I onto a high-resolution imaging detector. Experimental measurements from the prototype have demonstrated that the optic can focus X-rays from a microfocus X-ray tube to a spot having physical dimensions (approximately 1500 microns half-power diameter) consistent with those predicted by theory. Our theoretical and numerical analysis also indicate that an optic can be designed and build that ultimately can achieve 100 {micro}m spatial resolution with sufficient efficiency to perform in vivo single photon emission imaging studies in small animal.

  7. A portable automatic pressure delivery system for scar compression therapy in large animals

    NASA Astrophysics Data System (ADS)

    Ghassemi, Pejhman; Shupp, Jeffrey W.; Travis, Taryn E.; Gravunder, Andrew J.; Moffatt, Lauren T.; Ramella-Roman, Jessica C.

    2015-01-01

    Compression therapy has long been a standard treatment for hypertrophic scar prevention. However, due to the lack of objective, quantitative assessments, and measurements of scar severity, as well as the lack of a self-operated, controllable, and precise pressure delivery technique, limited concrete evidence exists, demonstrating compression therapy's efficacy. We have designed and built an automatic pressure delivery system to apply and maintain constant pressure on scar tissue in an animal model. A force sensor positioned on a compression plate reads the imposed force in real-time and sends the information to a feedback system controlling two position actuators. The actuators move accordingly to maintain a preset value of pressure onto the skin. The system was used in an in vivo model of compression therapy on hypertrophic scars. It was shown that the system was capable of delivering a constant pressure of 30 mmHg on scar wounds for a period of two weeks, and that phenotypic changes were seen in the wounds.

  8. An x-ray image guidance system for small animal stereotactic irradiation

    NASA Astrophysics Data System (ADS)

    Song, K. H.; Pidikiti, R.; Stojadinovic, S.; Speiser, M.; Seliounine, S.; Saha, D.; Solberg, T. D.

    2010-12-01

    An x-ray image-guided small animal stereotactic irradiator was developed and characterized to enable tumor visualization and accurate target localization for small field, high dose irradiation. The system utilizes a custom collimation system, a motorized positioning system (x, y, θ), a digital imaging panel and operating software, and is integrated with a commercial x-ray unit. The essential characteristics of the irradiator include small radiation fields (1-10 mm), high dose rate (>10 Gy min-1) and submillimeter target localization. The software enables computer-controlled image acquisition, stage motion and target localization providing simple and precise automated target localization. The imaging panel was characterized in terms of signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and spatial resolution. Overall localization accuracy and precision were assessed. SNR, CNR and spatial resolution are 24 dB, 21 dB and 2.8 lp mm-1, respectively, and localization accuracy is approximately 65 µm with 6 µm precision. With the aid of image guidance, system performance was subsequently used to evaluate radiation response in a rat orthotopic lung tumor effectively sparing normal tissues and in a mouse normal lung. The capabilities of 3D treatment and cone-beam computed tomography are presented for 3D localization and delivery as a work in progress.

  9. Design of a Second Generation Firewire Based Data Acquisition System for Small Animal PET Scanners

    PubMed Central

    Lewellen, T.K.; Miyaoka, R.S.; MacDonald, L.R.; Haselman, M.; DeWitt, D.; Hunter, William; Hauck, S.

    2009-01-01

    The University of Washington developed a Firewire based data acquisition system for the MiCES small animal PET scanner. Development work has continued on new imaging scanners that require more data channels and need to be able to operate within a MRI imaging system. To support these scanners, we have designed a new version of our data acquisition system that leverages the capabilities of modern field programmable gate arrays (FPGA). The new design preserves the basic approach of the original system, but puts almost all functions into the FPGA, including the Firewire elements, the embedded processor, and pulse timing and pulse integration. The design has been extended to support implementation of the position estimation and DOl algorithms developed for the cMiCE detector module. The design is centered around an acquisition node board (ANB) that includes 65 ADC channels, Firewire 1394b support, the FPGA, a serial command bus and signal lines to support a rough coincidence window implementation to reject singles events from being sent on the Firewire bus. Adapter boards convert detector signals into differential paired signals to connect to the ANB. PMID:20228958

  10. An x-ray image guidance system for small animal stereotactic irradiation.

    PubMed

    Song, K H; Pidikiti, R; Stojadinovic, S; Speiser, M; Seliounine, S; Saha, D; Solberg, T D

    2010-12-01

    An x-ray image-guided small animal stereotactic irradiator was developed and characterized to enable tumor visualization and accurate target localization for small field, high dose irradiation. The system utilizes a custom collimation system, a motorized positioning system (x, y, θ), a digital imaging panel and operating software, and is integrated with a commercial x-ray unit. The essential characteristics of the irradiator include small radiation fields (1-10 mm), high dose rate (>10 Gy min(-1)) and submillimeter target localization. The software enables computer-controlled image acquisition, stage motion and target localization providing simple and precise automated target localization. The imaging panel was characterized in terms of signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and spatial resolution. Overall localization accuracy and precision were assessed. SNR, CNR and spatial resolution are 24 dB, 21 dB and 2.8 lp mm(-1), respectively, and localization accuracy is approximately 65 µm with 6 µm precision. With the aid of image guidance, system performance was subsequently used to evaluate radiation response in a rat orthotopic lung tumor effectively sparing normal tissues and in a mouse normal lung. The capabilities of 3D treatment and cone-beam computed tomography are presented for 3D localization and delivery as a work in progress. PMID:21081818

  11. A modularized infrared light matrix system with high resolution for measuring animal behaviors.

    PubMed

    Young, M S; Li, Y C; Lin, M T

    1993-03-01

    The current study provides a new modularized infrared light matrix system (about $200 cost) which is designed to measure the horizontal gross or fine movements, vertical motion, clockwise or anticlockwise turnings, freezing time, and total distance traveled in rats. The system records the sequences of animal's activity in a computer-aided system with a resolution of 0.2 s in time or 1.6 cm in space, and permanently stores all the resulting data in file. The behavioral apparatus was tested for its sensitivity and usability by amphetamine-injected rats. It was found that intraperitoneal administration of amphetamine (1.25-2.50 mg/kg), but not normal saline, produced a dose-related increase in either the horizontal gross or fine movements, vertical motion, clockwise or anticlockwise turnings, or total dist