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Sample records for pet camera optimized

  1. Characterization of a PET Camera Optimized for ProstateImaging

    SciTech Connect

    Huber, Jennifer S.; Choong, Woon-Seng; Moses, William W.; Qi,Jinyi; Hu, Jicun; Wang, G.C.; Wilson, David; Oh, Sang; Huesman, RonaldH.; Derenzo, Stephen E.

    2005-11-11

    We present the characterization of a positron emission tomograph for prostate imaging that centers a patient between a pair of external curved detector banks (ellipse: 45 cm minor, 70 cm major axis). The distance between detector banks adjusts to allow patient access and to position the detectors as closely as possible for maximum sensitivity with patients of various sizes. Each bank is composed of two axial rows of 20 HR+ block detectors for a total of 80 detectors in the camera. The individual detectors are angled in the transaxial plane to point towards the prostate to reduce resolution degradation in that region. The detectors are read out by modified HRRT data acquisition electronics. Compared to a standard whole-body PET camera, our dedicated-prostate camera has the same sensitivity and resolution, less background (less randoms and lower scatter fraction) and a lower cost. We have completed construction of the camera. Characterization data and reconstructed images of several phantoms are shown. Sensitivity of a point source in the center is 946 cps/mu Ci. Spatial resolution is 4 mm FWHM in the central region.

  2. PETIROC2 based readout electronics optimization for Gamma Cameras and PET detectors

    NASA Astrophysics Data System (ADS)

    Monzo, J. M.; Aguilar, A.; González-Montoro, A.; Lamprou, E.; González, A. J.; Hernández, L.; Mazur, D.; Colom, R. J.; Benlloch, J. M.

    2017-02-01

    Developing front-end electronics to improve charge detection and time resolution in gamma-ray detectors is one of the main tasks to improve performance in new multimodal imaging systems that merge information of Magnetic Resonance Imaging and Gamma Camera or PET tomographs. The aim of this work is to study the behaviour and to optimize the performance of an ASIC for PET and Gamma Camera applications based on SiPMs detectors. PETIROC2 is a commercial ASIC developed by Weeroc to provide accurate charge and time coincidence resolutions. It has 32 analog input channels that are independently managed. Each channel is divided into two signals, one for time stamping using a TDC and another for charge measurement. In this work, PETIROC2 is evaluated in an experimental setup composed of two pixelated LYSO crystals based detectors, each coupled to a Hamamatsu 4×4 SiPM array. Both detectors are working in coincidence with a separation distance between them that can be modified. In the present work, an energy resolution of 13.6% FWHM and a time coincidence resolution of 815 ps FWHM have been obtained. These results will be useful to optimize and improve PETIROC2 based PET and Gamma Camera systems.

  3. An Educational PET Camera Model

    ERIC Educational Resources Information Center

    Johansson, K. E.; Nilsson, Ch.; Tegner, P. E.

    2006-01-01

    Positron emission tomography (PET) cameras are now in widespread use in hospitals. A model of a PET camera has been installed in Stockholm House of Science and is used to explain the principles of PET to school pupils as described here.

  4. Performance of the Tachyon Time-of-Flight PET Camera.

    PubMed

    Peng, Q; Choong, W-S; Vu, C; Huber, J S; Janecek, M; Wilson, D; Huesman, R H; Qi, Jinyi; Zhou, Jian; Moses, W W

    2015-02-01

    We have constructed and characterized a time-of-flight Positron Emission Tomography (TOF PET) camera called the Tachyon. The Tachyon is a single-ring Lutetium Oxyorthosilicate (LSO) based camera designed to obtain significantly better timing resolution than the ~ 550 ps found in present commercial TOF cameras, in order to quantify the benefit of improved TOF resolution for clinically relevant tasks. The Tachyon's detector module is optimized for timing by coupling the 6.15 × 25 mm(2) side of 6.15 × 6.15 × 25 mm(3) LSO scintillator crystals onto a 1-inch diameter Hamamatsu R-9800 PMT with a super-bialkali photocathode. We characterized the camera according to the NEMA NU 2-2012 standard, measuring the energy resolution, timing resolution, spatial resolution, noise equivalent count rates and sensitivity. The Tachyon achieved a coincidence timing resolution of 314 ps +/- ps FWHM over all crystal-crystal combinations. Experiments were performed with the NEMA body phantom to assess the imaging performance improvement over non-TOF PET. The results show that at a matched contrast, incorporating 314 ps TOF reduces the standard deviation of the contrast by a factor of about 2.3.

  5. Performance of the Tachyon Time-of-Flight PET Camera

    PubMed Central

    Peng, Q.; Choong, W.-S.; Vu, C.; Huber, J. S.; Janecek, M.; Wilson, D.; Huesman, R. H.; Qi, Jinyi; Zhou, Jian; Moses, W. W.

    2015-01-01

    We have constructed and characterized a time-of-flight Positron Emission Tomography (TOF PET) camera called the Tachyon. The Tachyon is a single-ring Lutetium Oxyorthosilicate (LSO) based camera designed to obtain significantly better timing resolution than the ~ 550 ps found in present commercial TOF cameras, in order to quantify the benefit of improved TOF resolution for clinically relevant tasks. The Tachyon’s detector module is optimized for timing by coupling the 6.15 × 25 mm2 side of 6.15 × 6.15 × 25 mm3 LSO scintillator crystals onto a 1-inch diameter Hamamatsu R-9800 PMT with a super-bialkali photocathode. We characterized the camera according to the NEMA NU 2-2012 standard, measuring the energy resolution, timing resolution, spatial resolution, noise equivalent count rates and sensitivity. The Tachyon achieved a coincidence timing resolution of 314 ps +/− ps FWHM over all crystal-crystal combinations. Experiments were performed with the NEMA body phantom to assess the imaging performance improvement over non-TOF PET. The results show that at a matched contrast, incorporating 314 ps TOF reduces the standard deviation of the contrast by a factor of about 2.3. PMID:26594057

  6. Performance of the Tachyon Time-of-Flight PET Camera

    DOE PAGES

    Peng, Q.; Choong, W. -S.; Vu, C.; ...

    2015-01-23

    We have constructed and characterized a time-of-flight Positron Emission Tomography (TOF PET) camera called the Tachyon. The Tachyon is a single-ring Lutetium Oxyorthosilicate (LSO) based camera designed to obtain significantly better timing resolution than the ~ 550 ps found in present commercial TOF cameras, in order to quantify the benefit of improved TOF resolution for clinically relevant tasks. The Tachyon's detector module is optimized for timing by coupling the 6.15 ×25 mm2 side of 6.15 ×6.15 ×25 mm3 LSO scintillator crystals onto a 1-inch diameter Hamamatsu R-9800 PMT with a super-bialkali photocathode. We characterized the camera according to the NEMAmore » NU 2-2012 standard, measuring the energy resolution, timing resolution, spatial resolution, noise equivalent count rates and sensitivity. The Tachyon achieved a coincidence timing resolution of 314 ps +/- 20 ps FWHM over all crystal-crystal combinations. Experiments were performed with the NEMA body phantom to assess the imaging performance improvement over non-TOF PET. We find that the results show that at a matched contrast, incorporating 314 ps TOF reduces the standard deviation of the contrast by a factor of about 2.3.« less

  7. Performance of the Tachyon Time-of-Flight PET Camera

    SciTech Connect

    Peng, Q.; Choong, W. -S.; Vu, C.; Huber, J. S.; Janecek, M.; Wilson, D.; Huesman, R. H.; Qi, Jinyi; Zhou, Jian; Moses, W. W.

    2015-01-23

    We have constructed and characterized a time-of-flight Positron Emission Tomography (TOF PET) camera called the Tachyon. The Tachyon is a single-ring Lutetium Oxyorthosilicate (LSO) based camera designed to obtain significantly better timing resolution than the ~ 550 ps found in present commercial TOF cameras, in order to quantify the benefit of improved TOF resolution for clinically relevant tasks. The Tachyon's detector module is optimized for timing by coupling the 6.15 ×25 mm2 side of 6.15 ×6.15 ×25 mm3 LSO scintillator crystals onto a 1-inch diameter Hamamatsu R-9800 PMT with a super-bialkali photocathode. We characterized the camera according to the NEMA NU 2-2012 standard, measuring the energy resolution, timing resolution, spatial resolution, noise equivalent count rates and sensitivity. The Tachyon achieved a coincidence timing resolution of 314 ps +/- 20 ps FWHM over all crystal-crystal combinations. Experiments were performed with the NEMA body phantom to assess the imaging performance improvement over non-TOF PET. We find that the results show that at a matched contrast, incorporating 314 ps TOF reduces the standard deviation of the contrast by a factor of about 2.3.

  8. Septa design for a prostate specific PET camera

    SciTech Connect

    Qi, Jinyi; Huber, Jennifer S.; Huesman, Ronald H.; Moses, William W.; Derenzo, Stephen E.; Budinger, Thomas F.

    2003-11-15

    The recent development of new prostate tracers has motivated us to build a low cost PET camera optimized to image the prostate. Coincidence imaging of positron emitters is achieved using a pair of external curved detector banks. The bottom bank is fixed below the patient bed, and the top bank moves upward for patient access and downward for maximum sensitivity. In this paper, we study the design of septa for the prostate camera using Monte Carlo simulations. The system performance is measured by the detectability of a prostate lesion. We have studied 17 septa configurations. The results show that the design of septa has a large impact on the lesion detection at a given activity concentration. Significant differences are also observed between the lesion detectability and the conventional noise equivalent count (NEC) performance, indicating that the NEC is not appropriate for the detection task.

  9. Triple-head gamma camera PET: system overview and performance characteristics.

    PubMed

    Grosev, D; Loncarić, S; Vandenberghe, S; Dodig, D

    2002-08-01

    Positron emission tomography (PET) is currently performed using either a dedicated PET scanner or scintillation gamma camera equipped with electronic circuitry for coincidence detection of 511 keV annihilation quanta (gamma camera PET system). Although the resolution limits of these two instruments are comparable, the sensitivity and count rate performance of the gamma camera PET system are several times lower than that of the PET scanner. Most gamma camera PET systems are manufactured as dual-detector systems capable of performing dual-head coincidence imaging. One possible step towards the improvement of the sensitivity of the gamma camera PET system is to add another detector head. This work investigates the characteristics of one such triple-head gamma camera PET system capable of performing triple-head coincidence imaging. The following performance characteristics of the system were assessed: spatial resolution, sensitivity, count rate performance. The spatial resolution, expressed as the full width at half-maximum (FWHM), at 1 cm radius is 5.9 mm; at 10 cm radius, the transverse radial resolution is 5.3 mm, whilst the transverse tangential and axial resolutions are 8.9 mm and 13.3 mm, respectively. The sensitivity for a standard cylindrical phantom is 255 counts.s(-1).MBq*(-1)), using a 30% width photopeak energy window. An increase of 35% in the PET sensitivity is achievable by opening an additional 30% width energy window in the Compton region. The count rate in coincidence mode, at the upper limit of the systems optimal performance, is 45 kc.s(-1) (kc=kilocounts) using the photopeak energy window only, and increases to 60 kc.s(-1) using the photopeak + Compton windows. Sensitivity results are compared with published data for a similar dual-head detector system.

  10. Advantages of improved timing accuracy in PET cameras using LSOscintillator

    SciTech Connect

    Moses, William W.

    2002-12-02

    PET scanners based on LSO have the potential forsignificantly better coincidence timing resolution than the 6 ns fwhmtypically achieved with BGO. This study analyzes the performanceenhancements made possible by improved timing as a function of thecoincidence time resolution. If 500 ps fwhm coincidence timing resolutioncan be achieved in a complete PET camera, the following four benefits canbe realized for whole-body FDG imaging: 1) The random event rate can bereduced by using a narrower coincidence timing window, increasing thepeak NECR by~;50 percent. 2) Using time-of-flight in the reconstructionalgorithm will reduce the noise variance by a factor of 5. 3) Emissionand transmission data can be acquired simultaneously, reducing the totalscan time. 4) Axial blurring can be reduced by using time-of-flight todetermine the correct axial plane that each event originated from. Whiletime-of-flight was extensively studied in the 1980's, practical factorslimited its effectiveness at that time and little attention has been paidto timing in PET since then. As these potential improvements aresubstantial and the advent of LSO PET cameras gives us the means toobtain them without other sacrifices, efforts to improve PET timingshould resume after their long dormancy.

  11. Streak camera dynamic range optimization

    SciTech Connect

    Wiedwald, J.D.; Lerche, R.A.

    1987-09-01

    The LLNL optical streak camera is used by the Laser Fusion Program in a wide range of applications. Many of these applications require a large recorded dynamic range. Recent work has focused on maximizing the dynamic range of the streak camera recording system. For our streak cameras, image intensifier saturation limits the upper end of the dynamic range. We have developed procedures to set the image intensifier gain such that the system dynamic range is maximized. Specifically, the gain is set such that a single streak tube photoelectron is recorded with an exposure of about five times the recording system noise. This ensures detection of single photoelectrons, while not consuming intensifier or recording system dynamic range through excessive intensifier gain. The optimum intensifier gain has been determined for two types of film and for a lens-coupled CCD camera. We have determined that by recording the streak camera image with a CCD camera, the system is shot-noise limited up to the onset of image intensifier nonlinearity. When recording on film, the film determines the noise at high exposure levels. There is discussion of the effects of slit width and image intensifier saturation on dynamic range. 8 refs.

  12. Performance modeling of a wearable brain PET (BET) camera

    NASA Astrophysics Data System (ADS)

    Schmidtlein, C. R.; Turner, J. N.; Thompson, M. O.; Mandal, K. C.; Häggström, I.; Zhang, J.; Humm, J. L.; Feiglin, D. H.; Krol, A.

    2016-03-01

    Purpose: To explore, by means of analytical and Monte Carlo modeling, performance of a novel lightweight and low-cost wearable helmet-shaped Brain PET (BET) camera based on thin-film digital Geiger Avalanche Photo Diode (dGAPD) with LSO and LaBr3 scintillators for imaging in vivo human brain processes for freely moving and acting subjects responding to various stimuli in any environment. Methods: We performed analytical and Monte Carlo modeling PET performance of a spherical cap BET device and cylindrical brain PET (CYL) device, both with 25 cm diameter and the same total mass of LSO scintillator. Total mass of LSO in both the BET and CYL systems is about 32 kg for a 25 mm thick scintillator, and 13 kg for 10 mm thick scintillator (assuming an LSO density of 7.3 g/ml). We also investigated a similar system using an LaBr3 scintillator corresponding to 22 kg and 9 kg for the 25 mm and 10 mm thick systems (assuming an LaBr3 density of 5.08 g/ml). In addition, we considered a clinical whole body (WB) LSO PET/CT scanner with 82 cm ring diameter and 15.8 cm axial length to represent a reference system. BET consisted of distributed Autonomous Detector Arrays (ADAs) integrated into Intelligent Autonomous Detector Blocks (IADBs). The ADA comprised of an array of small LYSO scintillator volumes (voxels with base a×a: 1.0 <= a <= 2.0 mm and length c: 3.0 <= c <= 6.0 mm) with 5-65 μm thick reflective layers on its five sides and sixth side optically coupled to the matching array of dGAPDs and processing electronics with total thickness of 50 μm. Simulated energy resolution was 10.8% and 3.3% for LSO and LaBr3 respectively and the coincidence window was set at 2 ns. The brain was simulated as a sphere of uniform F-18 activity with diameter of 10 cm embedded in a center of water sphere with diameter of 10 cm. Results: Analytical and Monte Carlo models showed similar results for lower energy window values (458 keV versus 445 keV for LSO, and 492 keV versus 485 keV for LaBr3

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

    DTIC Science & Technology

    2012-07-01

    Characterization of a Dedicated High-Resolution Breast PET Camera 5b. GRANT NUMBER W81XWH-10-1-0393 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d...characterizing a high resolution breast PET camera . We have received about 25% of the modules needed to construct the camera and about 80% of these passed...high voltage biasing circuitry. Energy resolutions of 11.8 +/- 0.3% FWHM at 511 keV are obtained and a coincidence time resolution of 9.8 +/- 0.7 ns

  14. Quality controls for gamma cameras and PET cameras: development of a free open-source ImageJ program

    NASA Astrophysics Data System (ADS)

    Carlier, Thomas; Ferrer, Ludovic; Berruchon, Jean B.; Cuissard, Regis; Martineau, Adeline; Loonis, Pierre; Couturier, Olivier

    2005-04-01

    Acquisition data and treatments for quality controls of gamma cameras and Positron Emission Tomography (PET) cameras are commonly performed with dedicated program packages, which are running only on manufactured computers and differ from each other, depending on camera company and program versions. The aim of this work was to develop a free open-source program (written in JAVA language) to analyze data for quality control of gamma cameras and PET cameras. The program is based on the free application software ImageJ and can be easily loaded on any computer operating system (OS) and thus on any type of computer in every nuclear medicine department. Based on standard parameters of quality control, this program includes 1) for gamma camera: a rotation center control (extracted from the American Association of Physics in Medicine, AAPM, norms) and two uniformity controls (extracted from the Institute of Physics and Engineering in Medicine, IPEM, and National Electronic Manufacturers Association, NEMA, norms). 2) For PET systems, three quality controls recently defined by the French Medical Physicist Society (SFPM), i.e. spatial resolution and uniformity in a reconstructed slice and scatter fraction, are included. The determination of spatial resolution (thanks to the Point Spread Function, PSF, acquisition) allows to compute the Modulation Transfer Function (MTF) in both modalities of cameras. All the control functions are included in a tool box which is a free ImageJ plugin and could be soon downloaded from Internet. Besides, this program offers the possibility to save on HTML format the uniformity quality control results and a warning can be set to automatically inform users in case of abnormal results. The architecture of the program allows users to easily add any other specific quality control program. Finally, this toolkit is an easy and robust tool to perform quality control on gamma cameras and PET cameras based on standard computation parameters, is free, run on

  15. Optimized PET imaging for 4D treatment planning in radiotherapy: the virtual 4D PET strategy.

    PubMed

    Gianoli, Chiara; Riboldi, Marco; Fontana, Giulia; Giri, Maria G; Grigolato, Daniela; Ferdeghini, Marco; Cavedon, Carlo; Baroni, Guido

    2015-02-01

    The purpose of the study is to evaluate the performance of a novel strategy, referred to as "virtual 4D PET", aiming at the optimization of hybrid 4D CT-PET scan for radiotherapy treatment planning. The virtual 4D PET strategy applies 4D CT motion modeling to avoid time-resolved PET image acquisition. This leads to a reduction of radioactive tracer administered to the patient and to a total acquisition time comparable to free-breathing PET studies. The proposed method exploits a motion model derived from 4D CT, which is applied to the free-breathing PET to recover respiratory motion and motion blur. The free-breathing PET is warped according to the motion model, in order to generate the virtual 4D PET. The virtual 4D PET strategy was tested on images obtained from a 4D computational anthropomorphic phantom. The performance was compared to conventional motion compensated 4D PET. Tests were also carried out on clinical 4D CT-PET scans coming from seven lung and liver cancer patients. The virtual 4D PET strategy was able to recover lesion motion, with comparable performance with respect to the motion compensated 4D PET. The compensation of the activity blurring due to motion was successfully achieved in terms of spill out removal. Specific limitations were highlighted in terms of partial volume compensation. Results on clinical 4D CT-PET scans confirmed the efficacy in 4D PET count statistics optimization, as equal to the free-breathing PET, and recovery of lesion motion. Compared to conventional motion compensation strategies that explicitly require 4D PET imaging, the virtual 4D PET strategy reduces clinical workload and computational costs, resulting in significant advantages for radiotherapy treatment planning.

  16. Towards optimal imaging with PET: an in silico feasibility study.

    PubMed

    McNamara, A L; Toghyani, M; Gillam, J E; Wu, K; Kuncic, Z

    2014-12-21

    The efficacy of Positron Emission Tomography (PET) imaging relies fundamentally on the ability of the system to accurately identify true coincidence events. With existing systems, this is currently accomplished with an energy acceptance criterion followed by correction techniques to remove suspected false coincidence events. These corrections generally result in signal and contrast loss and thus limit the PET system's ability to achieve optimum image quality. A key property of annihilation radiation is that the photons are polarised with respect to each other. This polarisation correlation offers a potentially powerful discriminator, independent of energy, to accurately identify true events. In this proof of concept study, we investigate how photon polarisation information can be exploited in PET imaging by developing a method to discriminate true coincidences using the polarisation correlation of annihilation pairs. We implement this method using a Geant4 PET simulation of a GE Advance/Discovery LS system and demonstrate the potential advantages of the polarisation coincidence selection method over a standard energy criterion method. Current PET ring detectors are not capable of exploiting the polarisation correlation of the photon pairs. Compton PET systems, however are promising candidates for this application. We demonstrate the feasibility of a two-component Compton camera system in identifying true coincidences with Monte Carlo simulations. Our study demonstrates the potential of improving signal gain using polarisation, particularly for high photon emission rates. We also demonstrate the ability of the Compton camera at exploiting this polarisation correlation in PET.

  17. Towards optimal imaging with PET: an in silico feasibility study

    NASA Astrophysics Data System (ADS)

    McNamara, A. L.; Toghyani, M.; Gillam, J. E.; Wu, K.; Kuncic, Z.

    2014-12-01

    The efficacy of Positron Emission Tomography (PET) imaging relies fundamentally on the ability of the system to accurately identify true coincidence events. With existing systems, this is currently accomplished with an energy acceptance criterion followed by correction techniques to remove suspected false coincidence events. These corrections generally result in signal and contrast loss and thus limit the PET system’s ability to achieve optimum image quality. A key property of annihilation radiation is that the photons are polarised with respect to each other. This polarisation correlation offers a potentially powerful discriminator, independent of energy, to accurately identify true events. In this proof of concept study, we investigate how photon polarisation information can be exploited in PET imaging by developing a method to discriminate true coincidences using the polarisation correlation of annihilation pairs. We implement this method using a Geant4 PET simulation of a GE Advance/Discovery LS system and demonstrate the potential advantages of the polarisation coincidence selection method over a standard energy criterion method. Current PET ring detectors are not capable of exploiting the polarisation correlation of the photon pairs. Compton PET systems, however are promising candidates for this application. We demonstrate the feasibility of a two-component Compton camera system in identifying true coincidences with Monte Carlo simulations. Our study demonstrates the potential of improving signal gain using polarisation, particularly for high photon emission rates. We also demonstrate the ability of the Compton camera at exploiting this polarisation correlation in PET.

  18. Dose Optimization in TOF-PET/MR Compared to TOF-PET/CT

    PubMed Central

    Queiroz, Marcelo A.; Delso, Gaspar; Wollenweber, Scott; Deller, Timothy; Zeimpekis, Konstantinos; Huellner, Martin; de Galiza Barbosa, Felipe; von Schulthess, Gustav; Veit-Haibach, Patrick

    2015-01-01

    Purpose To evaluate the possible activity reduction in FDG-imaging in a Time-of-Flight (TOF) PET/MR, based on cross-evaluation of patient-based NECR (noise equivalent count rate) measurements in PET/CT, cross referencing with phantom-based NECR curves as well as initial evaluation of TOF-PET/MR with reduced activity. Materials and Methods A total of 75 consecutive patients were evaluated in this study. PET/CT imaging was performed on a PET/CT (time-of-flight (TOF) Discovery D 690 PET/CT). Initial PET/MR imaging was performed on a newly available simultaneous TOF-PET/MR (Signa PET/MR). An optimal NECR for diagnostic purposes was defined in clinical patients (NECRP) in PET/CT. Subsequent optimal activity concentration at the acquisition time ([A]0) and target NECR (NECRT) were obtained. These data were used to predict the theoretical FDG activity requirement of the new TOF-PET/MR system. Twenty-five initial patients were acquired with (retrospectively reconstructed) different imaging times equivalent for different activities on the simultaneous PET/MR for the evaluation of clinically realistic FDG-activities. Results The obtained values for NECRP, [A]0 and NECRT were 114.6 (± 14.2) kcps (Kilocounts per second), 4.0 (± 0.7) kBq/mL and 45 kcps, respectively. Evaluating the NECRT together with the phantom curve of the TOF-PET/MR device, the theoretical optimal activity concentration was found to be approximately 1.3 kBq/mL, which represents 35% of the activity concentration required by the TOF-PET/CT. Initial evaluation on patients in the simultaneous TOF-PET/MR shows clinically realistic activities of 1.8 kBq/mL, which represent 44% of the required activity. Conclusion The new TOF-PET/MR device requires significantly less activity to generate PET-images with good-to-excellent image quality, due to improvements in detector geometry and detector technologies. The theoretically achievable dose reduction accounts for up to 65% but cannot be fully translated into clinical

  19. Optimization of PET system design for lesion detection

    SciTech Connect

    Qi, Jinyi

    2000-10-13

    Traditionally, the figures of merit used in designing a PET scanner are spatial resolution, noise equivalent count rate, noise equivalent sensitivity, etc. These measures, however, do not directly reflect the lesion detectability using the PET scanner. Here we propose to optimize PET scanner design directly for lesion detection. The signal-to-noise ratio (SNR) of lesion detection can be easily computed using the theoretical expressions that we have previously derived. Because no time consuming Monte Carlo simulation is needed, the theoretical expressions allow evaluation of a large range of parameters. The PET system parameters can then be chosen to achieve the maximum SNR for lesion detection. The simulation study shown in this paper was focused a single ring PET scanner without depth of interaction measurement. Randoms and scatters were also ignored.

  20. Detection of the optimal region of interest for camera oximetry.

    PubMed

    Karlen, Walter; Ansermino, J Mark; Dumont, Guy A; Scheffer, Cornie

    2013-01-01

    The estimation of heart rate and blood oxygen saturation with an imaging array on a mobile phone (camera oximetry) has great potential for mobile health applications as no additional hardware other than a camera and LED flash enabled phone are required. However, this approach is challenging as the configuration of the camera can negatively influence the estimation quality. Further, the number of photons recorded with the photo detector is largely dependent on the optical path length, resulting in a non-homogeneous image. In this paper we describe a novel method to automatically detect the optimal region of interest (ROI) for the captured image to extract a pulse waveform. We also present a study to select the optimal camera settings, notably the white balance. The experiments show that the incandescent white balance mode is the preferable setting for camera oximetry applications on the tested mobile phone (Samsung Galaxy Ace). Also, the ROI algorithm successfully identifies the frame regions which provide waveforms with the largest amplitudes.

  1. Optimally stabilized PET image denoising using trilateral filtering.

    PubMed

    Mansoor, Awais; Bagci, Ulas; Mollura, Daniel J

    2014-01-01

    Low-resolution and signal-dependent noise distribution in positron emission tomography (PET) images makes denoising process an inevitable step prior to qualitative and quantitative image analysis tasks. Conventional PET denoising methods either over-smooth small-sized structures due to resolution limitation or make incorrect assumptions about the noise characteristics. Therefore, clinically important quantitative information may be corrupted. To address these challenges, we introduced a novel approach to remove signal-dependent noise in the PET images where the noise distribution was considered as Poisson-Gaussian mixed. Meanwhile, the generalized Anscombe's transformation (GAT) was used to stabilize varying nature of the PET noise. Other than noise stabilization, it is also desirable for the noise removal filter to preserve the boundaries of the structures while smoothing the noisy regions. Indeed, it is important to avoid significant loss of quantitative information such as standard uptake value (SUV)-based metrics as well as metabolic lesion volume. To satisfy all these properties, we extended bilateral filtering method into trilateral filtering through multiscaling and optimal Gaussianization process. The proposed method was tested on more than 50 PET-CT images from various patients having different cancers and achieved the superior performance compared to the widely used denoising techniques in the literature.

  2. TU-A-18A-01: Basic Principles of PET/CT, Calibration Methods and Contrast Recovery Across Multiple Cameras

    SciTech Connect

    Kappadath, S; Nye, J

    2014-06-15

    This continuing education session will discuss the physical principles of PET/CT imaging and characterization of contrast recovery using accreditation phantoms. A detailed overview will be given on the physical principles of PET including positron decay physics, 2D and 3D data acquisition, time-of-flight, scatter correction, CT attenuation correction, and image reconstruction. Instrument quality control and calibration procedures will be discussed. Technical challenges, common image artifacts and strategies to mitigate these issues will also be discussed. Data will be presented on acquisition techniques and reconstruction parameters affecting contrast recovery. The discussion will emphasize the minimization of reconstruction differences in quantification metrics such as SUV and contrast recovery coefficients for the NEMA and ACR clinical trial phantoms. Data from new and older generation scanners will be shown including comparison of contrast recovery measurements to their analytical solutions. The goal of this session is to update attendees on the quality control and calibration of PET/CT scanners, on methods to establish a common calibration for PET/CT scanners to control for instrument variance across multiple sites. Learning Objectives: Review the physical principles of PET/CT, quality control and calibration Gain further understanding on how to apply techniques for improving quantitative agreement across multiple cameras Describe the differences between measured and expected contrast recovery for the NEMA and ACR PET phantoms.

  3. PET image reconstruction: mean, variance, and optimal minimax criterion

    NASA Astrophysics Data System (ADS)

    Liu, Huafeng; Gao, Fei; Guo, Min; Xue, Liying; Nie, Jing; Shi, Pengcheng

    2015-04-01

    Given the noise nature of positron emission tomography (PET) measurements, it is critical to know the image quality and reliability as well as expected radioactivity map (mean image) for both qualitative interpretation and quantitative analysis. While existing efforts have often been devoted to providing only the reconstructed mean image, we present a unified framework for joint estimation of the mean and corresponding variance of the radioactivity map based on an efficient optimal min-max criterion. The proposed framework formulates the PET image reconstruction problem to be a transformation from system uncertainties to estimation errors, where the minimax criterion is adopted to minimize the estimation errors with possibly maximized system uncertainties. The estimation errors, in the form of a covariance matrix, express the measurement uncertainties in a complete way. The framework is then optimized by ∞-norm optimization and solved with the corresponding H∞ filter. Unlike conventional statistical reconstruction algorithms, that rely on the statistical modeling methods of the measurement data or noise, the proposed joint estimation stands from the point of view of signal energies and can handle from imperfect statistical assumptions to even no a priori statistical assumptions. The performance and accuracy of reconstructed mean and variance images are validated using Monte Carlo simulations. Experiments on phantom scans with a small animal PET scanner and real patient scans are also conducted for assessment of clinical potential.

  4. Data Acquisition and Image Reconstruction Systems from the miniPET Scanners to the CARDIOTOM Camera

    NASA Astrophysics Data System (ADS)

    Valastván, I.; Imrek, J.; Hegyesi, G.; Molnár, J.; Novák, D.; Bone, D.; Kerek, A.

    2007-11-01

    Nuclear imaging devices play an important role in medical diagnosis as well as drug research. The first and second generation data acquisition systems and the image reconstruction library developed provide a unified hardware and software platform for the miniPET-I, miniPET-II small animal PET scanners and for the CARDIOTOM™.

  5. Initial experience in primal-dual optimization reconstruction from sparse-PET patient data

    NASA Astrophysics Data System (ADS)

    Zhang, Zheng; Ye, Jinghan; Chen, Buxin; Perkins, Amy E.; Rose, Sean; Sidky, Emil Y.; Kao, Chien-Min; Xia, Dan; Tung, Chi-Hua; Pan, Xiaochuan

    2016-03-01

    There exists interest in designing a PET system with reduced detectors due to cost concerns, while not significantly compromising the PET utility. Recently developed optimization-based algorithms, which have demonstrated the potential clinical utility in image reconstruction from sparse CT data, may be used for enabling such design of innovative PET systems. In this work, we investigate a PET configuration with reduced number of detectors, and carry out preliminary studies from patient data collected by use of such sparse-PET configuration. We consider an optimization problem combining Kullback-Leibler (KL) data fidelity with an image TV constraint, and solve it by using a primal-dual optimization algorithm developed by Chambolle and Pock. Results show that advanced algorithms may enable the design of innovative PET configurations with reduced number of detectors, while yielding potential practical PET utilities.

  6. Optimization of PET instrumentation for brain activation studies

    SciTech Connect

    Dahlbom, M.; Cherry, S.R.; Hoffman, E.J. . Dept. of Radiological Science); Eriksson, L. . Dept. of Clinical Neurophysiology); Wienhard, K. )

    1993-08-01

    By performing cerebral blood flow studies with positron emission tomography (PET), and comparing blood flow images of different states of activation, functional mapping of the brain is possible. The ability of current commercial instruments to perform such studies is investigated in this work, based on a comparison of noise equivalent count (NEC) rates. Differences in the NEC performance of the different scanners in conjunction with scanner design parameters, provide insights into the importance of block design (size, dead time, crystal thickness) and overall scanner design (sensitivity and scatter fraction) for optimizing data from activation studies. The newer scanners with removable septa, operating with 3-D acquisition, have much higher sensitivity, but require new methodology for optimized operation. Only by administering multiple low doses (fractionation) of the flow tracer can the high sensitivity be utilized.

  7. Performance evaluation and optimization of the MiniPET-II scanner

    NASA Astrophysics Data System (ADS)

    Lajtos, Imre; Emri, Miklos; Kis, Sandor A.; Opposits, Gabor; Potari, Norbert; Kiraly, Beata; Nagy, Ferenc; Tron, Lajos; Balkay, Laszlo

    2013-04-01

    This paper presents results of the performance of a small animal PET system (MiniPET-II) installed at our Institute. MiniPET-II is a full ring camera that includes 12 detector modules in a single ring comprised of 1.27×1.27×12 mm3 LYSO scintillator crystals. The axial field of view and the inner ring diameter are 48 mm and 211 mm, respectively. The goal of this study was to determine the NEMA-NU4 performance parameters of the scanner. In addition, we also investigated how the calculated parameters depend on the coincidence time window (τ=2, 3 and 4 ns) and the low threshold settings of the energy window (Elt=250, 350 and 450 keV). Independent measurements supported optimization of the effective system radius and the coincidence time window of the system. We found that the optimal coincidence time window and low threshold energy window are 3 ns and 350 keV, respectively. The spatial resolution was close to 1.2 mm in the center of the FOV with an increase of 17% at the radial edge. The maximum value of the absolute sensitivity was 1.37% for a point source. Count rate tests resulted in peak values for the noise equivalent count rate (NEC) curve and scatter fraction of 14.2 kcps (at 36 MBq) and 27.7%, respectively, using the rat phantom. Numerical values of the same parameters obtained for the mouse phantom were 55.1 kcps (at 38.8 MBq) and 12.3%, respectively. The recovery coefficients of the image quality phantom ranged from 0.1 to 0.87. Altering the τ and Elt resulted in substantial changes in the NEC peak and the sensitivity while the effect on the image quality was negligible. The spatial resolution proved to be, as expected, independent of the τ and Elt. The calculated optimal effective system radius (resulting in the best image quality) was 109 mm. Although the NEC peak parameters do not compare favorably with those of other small animal scanners, it can be concluded that under normal counting situations the MiniPET-II imaging capability assures remarkably

  8. Investigation of optimization-based reconstruction with an image-total-variation constraint in PET

    NASA Astrophysics Data System (ADS)

    Zhang, Zheng; Ye, Jinghan; Chen, Buxin; Perkins, Amy E.; Rose, Sean; Sidky, Emil Y.; Kao, Chien-Min; Xia, Dan; Tung, Chi-Hua; Pan, Xiaochuan

    2016-08-01

    Interest remains in reconstruction-algorithm research and development for possible improvement of image quality in current PET imaging and for enabling innovative PET systems to enhance existing, and facilitate new, preclinical and clinical applications. Optimization-based image reconstruction has been demonstrated in recent years of potential utility for CT imaging applications. In this work, we investigate tailoring the optimization-based techniques to image reconstruction for PET systems with standard and non-standard scan configurations. Specifically, given an image-total-variation (TV) constraint, we investigated how the selection of different data divergences and associated parameters impacts the optimization-based reconstruction of PET images. The reconstruction robustness was explored also with respect to different data conditions and activity up-takes of practical relevance. A study was conducted particularly for image reconstruction from data collected by use of a PET configuration with sparsely populated detectors. Overall, the study demonstrates the robustness of the TV-constrained, optimization-based reconstruction for considerably different data conditions in PET imaging, as well as its potential to enable PET configurations with reduced numbers of detectors. Insights gained in the study may be exploited for developing algorithms for PET-image reconstruction and for enabling PET-configuration design of practical usefulness in preclinical and clinical applications.

  9. Comparison of Imaging Characteristics of (124)I PET for Determination of Optimal Energy Window on the Siemens Inveon PET.

    PubMed

    Yu, A Ram; Kim, Hee-Joung; Lim, Sang Moo; Kim, Jin Su

    2016-01-01

    Purpose. (124)I has a half-life of 4.2 days, which makes it suitable for imaging over several days over its uptake and washout phases. However, it has a low positron branching ratio (23%), because of prompt gamma coincidence due to high-energy γ-photons (602 to 1,691 keV), which are emitted in cascade with positrons. Methods. In this study, we investigated the optimal PET energy window for (124)I PET based on image characteristics of reconstructed PET. Image characteristics such as nonuniformities, recovery coefficients (RCs), and the spillover ratios (SORs) of (124)I were measured as described in NEMA NU 4-2008 standards. Results. The maximum and minimum prompt gamma coincidence fraction (PGF) were 33% and 2% in 350~800 and 400~590 keV, respectively. The difference between best and worst uniformity in the various energy windows was less than 1%. The lowest SORs of (124)I were obtained at 350~750 keV in nonradioactive water compartment. Conclusion. Optimal energy window should be determined based on image characteristics. Our developed correction method would be useful for the correction of high-energy prompt gamma photon in (124)I PET. In terms of the image quality of (124)I PET, our findings indicate that an energy window of 350~750 keV would be optimal.

  10. ECAT ART - a continuously rotating PET camera: performance characteristics, initial clinical studies, and installation considerations in a nuclear medicine department.

    PubMed

    Bailey, D L; Young, H; Bloomfield, P M; Meikle, S R; Glass, D; Myers, M J; Spinks, T J; Watson, C C; Luk, P; Peters, A M; Jones, T

    1997-01-01

    Advances in fully three-dimensional (3D) image reconstruction techniques have permitted the development of a commercial, rotating, partial ring, fully 3D positron emission tomographic (PET) scanner, the ECAT ART. The system has less than one-half the number of bismuth germanate detectors compared with a full ring scanner with the equivalent field of view, resulting in reduced capital cost. The performance characteristics, implications for installation in a nuclear medicine department, and clinical utility of the scanner are presented in this report. The sensitivity (20 cm diameterx20 cm long cylindrical phantom, no scatter correction) is 11400 cps.kBq-1.ml-1. This compares with 5800 and 40500 cps.kBq-1.ml-1 in 2D and 3D respectively for the equivalent full ring scanner (ECAT EXACT). With an energy window of 350-650 keV the maximum noise equivalent count (NEC) rate was 27 kcps at a radioactivity concentration of approximately 15 kBq.ml-1 in the cylinder. Spatial resolution is approximately 6 mm full width at half maximum on axis degrading to just under 8 mm at a distance of 20 cm off axis. Installation and use within the nuclear medicine department does not appreciably increase background levels of radiation on gamma cameras in adjacent rooms and the dose rate to an operator in the same room is 2 microSv. h-1 for a typical fluorine-18 fluorodeoxyglucose (18F-FDG) study with an initial injected activity of 370 MBq. The scanner has been used for clinical imaging with18F-FDG for neurological and oncological applications. Its novel use for imaging iron-52 transferrin for localising erythropoietic activity demonstrates its sensitivity and resolution advantages over a conventional dual-headed gamma camera. The ECAT ART provides a viable alternative to conventional full ring PET scanners without compromising the performance required for clinical PET imaging.

  11. Simultaneous Camera Path Optimization and Distraction Removal for Improving Amateur Video.

    PubMed

    Zhang, Fang-Lue; Wang, Jue; Zhao, Han; Martin, Ralph R; Hu, Shi-Min

    2015-12-01

    A major difference between amateur and professional video lies in the quality of camera paths. Previous work on video stabilization has considered how to improve amateur video by smoothing the camera path. In this paper, we show that additional changes to the camera path can further improve video aesthetics. Our new optimization method achieves multiple simultaneous goals: 1) stabilizing video content over short time scales; 2) ensuring simple and consistent camera paths over longer time scales; and 3) improving scene composition by automatically removing distractions, a common occurrence in amateur video. Our approach uses an L(1) camera path optimization framework, extended to handle multiple constraints. Two passes of optimization are used to address both low-level and high-level constraints on the camera path. The experimental and user study results show that our approach outputs video that is perceptually better than the input, or the results of using stabilization only.

  12. HIGH-RESOLUTION L(Y)SO DETECTORS USING PMT-QUADRANT-SHARING FOR HUMAN & ANIMAL PET CAMERAS.

    PubMed

    Ramirez, Rocio A; Liu, Shitao; Liu, Jiguo; Zhang, Yuxuan; Kim, Soonseok; Baghaei, Hossain; Li, Hongdi; Wang, Yu; Wong, Wai-Hoi

    2008-06-01

    We developed high resolution L(Y)SO detectors for human and animal PET applications using Photomultiplier-quadrant-sharing (PQS) technology. The crystal sizes were 1.27 × 1.27 × 10 mm(3) for the animal PQS-blocks and 3.25 × 3.25 × 20 mm(3) for human ones. Polymer mirror film patterns (PMR) were placed between crystals as reflector. The blocks were assembled together using optical grease and wrapped by Teflon tape. The blocks were coupled to regular round PMT's of 19/51 mm in PQS configuration. List-mode data of Ga-68 source (511 KeV) were acquired with our high yield pileup-event recovery (HYPER) electronics and data acquisition software. The high voltage bias was 1100V. Crystal decoding maps and individual crystal energy resolutions were extracted from the data. To investigate the potential imaging resolution of the PET cameras with these blocks, we used GATE (Geant4 Application for Tomographic Emission) simulation package. GATE is a GEANT4 based software toolkit for realistic simulation of PET and SPECT systems. The packing fractions of these blocks were found to be 95.6% and 98.2%. From the decoding maps, all 196 and 225 crystals were clearly identified. The average energy resolutions were 14.0% and 15.6%. For small animal PET systems, the detector ring diameter was 16.5 cm with an axial field of view (AFOV) of 11.8 cm. The simulation data suggests that a reconstructed radial (tangential) spatial resolution of 1.24 (1.25) mm near the center is potentially achievable. For the wholebody human PET systems, the detector ring diameter was 86 cm. The simulation data suggests that a reconstructed radial (tangential) spatial resolution of 3.09(3.38) mm near the center is potentially achievable. From this study we can conclude that PQS design could achieve high spatial resolutions and excellent energy resolutions on human and animal PET systems with substantially lower production costs and inexpensive readout devices.

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

    DTIC Science & Technology

    2011-07-01

    detector design that is able to measure annihilation radiation coming from the PET tracer in 3 dimensions, using many 1 × 1 × 1 mm3 scintillation crystals. 2...Gonzalez, P. D. Olcott, A. Vandenbroucke, C. S. Levin Mixture Model for Fast Estimation of Positron Range 7 2. P. D. Reynolds, F. W. Lau, A. Vandenbroucke, C

  14. Count rate performance and deadtime analysis of the new 3D PETRRA PET camera

    NASA Astrophysics Data System (ADS)

    Wells, Kevin; Kakana, Christina; Ott, Robert J.; Flower, M.; Divoli, Antigoni; Meriaux, Sebastian; Bateman, J. E.; Stephenson, R.; Duxbury, D.; Spill, E. J.

    2001-12-01

    We report on the count-rate performance of the unique PETRRA positron camera at activities up to 60MBq. The camera consists of two large area detectors, each comprising a tiled array of 10mm thick BaF2 scintillation crystals interfaced to a multi-step avalanche chamber filled with 4.2mbar of pure TMAE vapor. Preliminary results demonstrate coincident count rates of over 80kcps for a cylindrical (20x20cm3) phantom with 50MBq of F-18 in the field-of-view using a 20ns coincidence time window. Each component of the readout cycle has been characterized in terms of dead-time loss. The camera's dead-time related count loss is well-described by a paralysable model with a dead-time of ~500ns. Other sources of count rate loss are also discussed.

  15. Optimizing a three-stage Compton camera for measuring prompt gamma rays emitted during proton radiotherapy

    NASA Astrophysics Data System (ADS)

    Peterson, S. W.; Robertson, D.; Polf, J.

    2010-11-01

    In this work, we investigate the use of a three-stage Compton camera to measure secondary prompt gamma rays emitted from patients treated with proton beam radiotherapy. The purpose of this study was (1) to develop an optimal three-stage Compton camera specifically designed to measure prompt gamma rays emitted from tissue and (2) to determine the feasibility of using this optimized Compton camera design to measure and image prompt gamma rays emitted during proton beam irradiation. The three-stage Compton camera was modeled in Geant4 as three high-purity germanium detector stages arranged in parallel-plane geometry. Initially, an isotropic gamma source ranging from 0 to 15 MeV was used to determine lateral width and thickness of the detector stages that provided the optimal detection efficiency. Then, the gamma source was replaced by a proton beam irradiating a tissue phantom to calculate the overall efficiency of the optimized camera for detecting emitted prompt gammas. The overall calculated efficiencies varied from ~10-6 to 10-3 prompt gammas detected per proton incident on the tissue phantom for several variations of the optimal camera design studied. Based on the overall efficiency results, we believe it feasible that a three-stage Compton camera could detect a sufficient number of prompt gammas to allow measurement and imaging of prompt gamma emission during proton radiotherapy.

  16. Optimizing a three-stage Compton camera for measuring prompt gamma rays emitted during proton radiotherapy.

    PubMed

    Peterson, S W; Robertson, D; Polf, J

    2010-11-21

    In this work, we investigate the use of a three-stage Compton camera to measure secondary prompt gamma rays emitted from patients treated with proton beam radiotherapy. The purpose of this study was (1) to develop an optimal three-stage Compton camera specifically designed to measure prompt gamma rays emitted from tissue and (2) to determine the feasibility of using this optimized Compton camera design to measure and image prompt gamma rays emitted during proton beam irradiation. The three-stage Compton camera was modeled in Geant4 as three high-purity germanium detector stages arranged in parallel-plane geometry. Initially, an isotropic gamma source ranging from 0 to 15 MeV was used to determine lateral width and thickness of the detector stages that provided the optimal detection efficiency. Then, the gamma source was replaced by a proton beam irradiating a tissue phantom to calculate the overall efficiency of the optimized camera for detecting emitted prompt gammas. The overall calculated efficiencies varied from ∼ 10(-6) to 10(-3) prompt gammas detected per proton incident on the tissue phantom for several variations of the optimal camera design studied. Based on the overall efficiency results, we believe it feasible that a three-stage Compton camera could detect a sufficient number of prompt gammas to allow measurement and imaging of prompt gamma emission during proton radiotherapy.

  17. Robust Video Stabilization Using Particle Keypoint Update and l1-Optimized Camera Path

    PubMed Central

    Jeon, Semi; Yoon, Inhye; Jang, Jinbeum; Yang, Seungji; Kim, Jisung; Paik, Joonki

    2017-01-01

    Acquisition of stabilized video is an important issue for various type of digital cameras. This paper presents an adaptive camera path estimation method using robust feature detection to remove shaky artifacts in a video. The proposed algorithm consists of three steps: (i) robust feature detection using particle keypoints between adjacent frames; (ii) camera path estimation and smoothing; and (iii) rendering to reconstruct a stabilized video. As a result, the proposed algorithm can estimate the optimal homography by redefining important feature points in the flat region using particle keypoints. In addition, stabilized frames with less holes can be generated from the optimal, adaptive camera path that minimizes a temporal total variation (TV). The proposed video stabilization method is suitable for enhancing the visual quality for various portable cameras and can be applied to robot vision, driving assistant systems, and visual surveillance systems. PMID:28208622

  18. Robust Video Stabilization Using Particle Keypoint Update and l₁-Optimized Camera Path.

    PubMed

    Jeon, Semi; Yoon, Inhye; Jang, Jinbeum; Yang, Seungji; Kim, Jisung; Paik, Joonki

    2017-02-10

    Acquisition of stabilized video is an important issue for various type of digital cameras. This paper presents an adaptive camera path estimation method using robust feature detection to remove shaky artifacts in a video. The proposed algorithm consists of three steps: (i) robust feature detection using particle keypoints between adjacent frames; (ii) camera path estimation and smoothing; and (iii) rendering to reconstruct a stabilized video. As a result, the proposed algorithm can estimate the optimal homography by redefining important feature points in the flat region using particle keypoints. In addition, stabilized frames with less holes can be generated from the optimal, adaptive camera path that minimizes a temporal total variation (TV). The proposed video stabilization method is suitable for enhancing the visual quality for various portable cameras and can be applied to robot vision, driving assistant systems, and visual surveillance systems.

  19. Optimization of microfluidic PET tracer synthesis with Cerenkov imaging†

    PubMed Central

    Dooraghi, Alex A.; Keng, Pei Y.; Chen, Supin; Javed, Muhammad R.; Kim, Chang-Jin “CJ”; Chatziioannou, Arion F.; van Dam, R. Michael

    2013-01-01

    Microfluidic technologies provide an attractive platform for the synthesis of radiolabeled compounds. Visualization of radioisotopes on chip is critical for synthesis optimization and technological development. With Cerenkov imaging, beta particle emitting isotopes can be localized with a sensitive CCD camera. In order for Cerenkov imaging to also serve as a quantitative tool, it is necessary to understand how material properties relevant to Cerenkov emission, namely, index of refraction and beta particle stopping power, affect Cerenkov light output. In this report, we investigate the fundamental physical characteristics of Cerenkov photon yield at different stages of [18F]FDG synthesis on the electrowetting on dielectric (EWOD) microfluidic platform. We also demonstrate how Cerenkov imaging has enabled synthesis optimization. Geant4, a Monte Carlo program applied extensively in high energy physics, is used to simulate Cerenkov photon yield from 18F beta particles traversing materials of interest during [18F]FDG synthesis on chip. Our simulations show that the majority (approximately two-thirds) of the 18F beta particle energy available to produce Cerenkov photons is deposited on the glass plates of the EWOD chip. This result suggests the possibility of using a single calibration factor to convert Cerenkov signal to radioactivity, independent of droplet composition. We validate our simulations with a controlled measurement examining varying ratios of [18O]H2O, dimethyl sulfoxide (DMSO), and acetonitrile (MeCN), and find a consistent calibration independent of solvent composition. However, the calibration factor may underestimate the radioactivity in actual synthesis due to discoloration of the droplet during certain steps of probe synthesis. In addition to the attractive quantitative potential of Cerenkov imaging, this imaging strategy provides indispensable qualitative data to guide synthesis optimization. We are able to use this imaging technique to optimize the

  20. The effect of β + energy on performance of a small animal PET camera

    NASA Astrophysics Data System (ADS)

    Partridge, M.; Spinelli, A.; Ryder, W.; Hindorf, C.

    2006-12-01

    The effective spatial resolution of a positron emission tomography (PET) scanner is determined in part by the initial energy of the positron, which is a function of the radionuclide. For F-18 ( Emax=0.633 MeV) the mean positron range in water is small (0.6 mm). However, many other useful positron-emitting nuclides have higher energies, for example Ga-68 ( Emax=1.899 MeV, mean range 2.9 mm) has one of the highest. The performance of a non-rotating, 16 module high density avalanche chamber (quad-HIDAC) small animal PET scanner was measured using both F-18 and Ga-68 to represent the extremes of high and low positron energy. The count rate performance—scatter fraction and noise-equivalent count rate (NEC)—were measured for both isotopes. Data were also collected for a spatial resolution phantom with rectangular arrays of holes of diameter 2.0, 1.5, 1.0 and 0.5 mm with the centres separated by 4.0, 3.0, 2.0 and 1.0 mm respectively. The NEC, measured for both 70 and 200 cm 3 cylindrical phantoms, was approximately linear up to 30 MBq, but shows a rapid drop-off above this value. The spatial resolution phantom showed that 1 mm objects are just resolved with F-18, but none of the targets are resolved for Ga-68. In conclusion, spatial resolution is dominated by the choice of isotope down to 1 mm, with sensitivity and count-rate data being largely independent of positron range.

  1. Optimization of the protocols for the use of contrast agents in PET/CT studies.

    PubMed

    Pelegrí Martínez, L; Kohan, A A; Vercher Conejero, J L

    The introduction of PET/CT scanners in clinical practice in 1998 has improved care for oncologic patients throughout the clinical pathway, from the initial diagnosis of disease through the evaluation of the response to treatment to screening for possible recurrence. The CT component of a PET/CT study is used to correct the attenuation of PET studies; CT also provides anatomic information about the distribution of the radiotracer. CT is especially useful in situations where PET alone can lead to false positives and false negatives, and CT thereby improves the diagnostic performance of PET. The use of intravenous or oral contrast agents and optimal CT protocols have improved the detection and characterization of lesions. However, there are circumstances in which the systematic use of contrast agents is not justified. The standard acquisition in PET/CT scanners is the whole body protocol, but this can lead to artifacts due to the position of patients and respiratory movements between the CT and PET acquisitions. This article discusses these aspects from a constructive perspective with the aim of maximizing the diagnostic potential of PET/CT and providing better care for patients.

  2. Optimal Co-segmentation of Tumor in PET-CT Images with Context Information

    PubMed Central

    Song, Qi; Bai, Junjie; Han, Dongfeng; Bhatia, Sudershan; Sun, Wenqing; Rockey, William; Bayouth, John E.; Buatti, John M.

    2014-01-01

    PET-CT images have been widely used in clinical practice for radiotherapy treatment planning of the radiotherapy. Many existing segmentation approaches only work for a single imaging modality, which suffer from the low spatial resolution in PET or low contrast in CT. In this work we propose a novel method for the co-segmentation of the tumor in both PET and CT images, which makes use of advantages from each modality: the functionality information from PET and the anatomical structure information from CT. The approach formulates the segmentation problem as a minimization problem of a Markov Random Field (MRF) model, which encodes the information from both modalities. The optimization is solved using a graph-cut based method. Two sub-graphs are constructed for the segmentation of the PET and the CT images, respectively. To achieve consistent results in two modalities, an adaptive context cost is enforced by adding context arcs between the two subgraphs. An optimal solution can be obtained by solving a single maximum flow problem, which leads to simultaneous segmentation of the tumor volumes in both modalities. The proposed algorithm was validated in robust delineation of lung tumors on 23 PET-CT datasets and two head-and-neck cancer subjects. Both qualitative and quantitative results show significant improvement compared to the graph cut methods solely using PET or CT. PMID:23693127

  3. Study of the performance of a novel 1 mm resolution dual-panel PET camera design dedicated to breast cancer imaging using Monte Carlo simulation

    SciTech Connect

    Zhang Jin; Olcott, Peter D.; Chinn, Garry; Foudray, Angela M. K.; Levin, Craig S.

    2007-02-15

    We studied the performance of a dual-panel positron emission tomography (PET) camera dedicated to breast cancer imaging using Monte Carlo simulation. The PET camera under development has two 10x15 cm{sup 2} plates that are constructed from arrays of 1x1x3 mm{sup 3} LSO crystals coupled to novel ultra-thin (<200 {mu}m) silicon position-sensitive avalanche photodiodes (PSAPD). In this design the photodetectors are configured ''edge-on'' with respect to incoming photons which encounter a minimum of 2 cm thick of LSO with directly measured photon interaction depth. Simulations predict that this camera will have 10-15% photon sensitivity, for an 8-4 cm panel separation. Detector measurements show {approx}1 mm{sup 3} intrinsic spatial resolution, <12% energy resolution, and {approx}2 ns coincidence time resolution. By performing simulated dual-panel PET studies using a phantom comprising active breast, heart, and torso tissue, count performance was studied as a function of coincident time and energy windows. We also studied visualization of hot spheres of 2.5-4.0 mm diameter and various locations within the simulated breast tissue for 1x1x3 mm{sup 3}, 2x2x10 mm{sup 3}, 3x3x30 mm{sup 3}, and 4x4x20 mm{sup 3} LSO crystal resolutions and different panel separations. Images were reconstructed by focal plane tomography with attenuation and normalization corrections applied. Simulation results indicate that with an activity concentration ratio of tumor:breast:heart:torso of 10:1:10:1 and 30 s of acquisition time, only the dual-plate PET camera comprising 1x1x3 mm{sup 3} crystals could resolve 2.5 mm diameter spheres with an average peak-to-valley ratio of 1.3.

  4. Characterization of a module with pixelated CdTe detectors for possible PET, PEM and compton camera applications

    NASA Astrophysics Data System (ADS)

    Ariño-Estrada, G.; Chmeissani, M.; de Lorenzo, G.; Puigdengoles, C.; Martínez, R.; Cabruja, E.

    2014-05-01

    We present the measurement of the energy resolution and the impact of charge sharing for a pixel CdTe detector. This detector will be used in a novel conceptual design for diagnostic systems in the field of nuclear medicine such as positron emission tomography (PET), positron emission mammography (PEM) and Compton camera. The detector dimensions are 10 mm × 10 mm × 2 mm and with a pixel pitch of 1 mm × 1 mm. The pixel CdTe detector is a Schottky diode and it was tested at a bias of -1000 V. The VATAGP7.1 frontend ASIC was used for the readout of the pixel detector and the corresponding single channel electronic noise was found to be σ < 2 keV for all the pixels. We have achieved an energy resolution, FWHM/Epeak, of 7.1%, 4.5% and 0.98% for 59.5, 122 and 511 keV respectively. The study of the charge sharing shows that 16% of the events deposit part of their energy in the adjacent pixel.

  5. Optimal Design of Anger Camera for Bremsstrahlung Imaging: Monte Carlo Evaluation

    PubMed Central

    Walrand, Stephan; Hesse, Michel; Wojcik, Randy; Lhommel, Renaud; Jamar, François

    2014-01-01

    A conventional Anger camera is not adapted to bremsstrahlung imaging and, as a result, even using a reduced energy acquisition window, geometric x-rays represent <15% of the recorded events. This increases noise, limits the contrast, and reduces the quantification accuracy. Monte Carlo (MC) simulations of energy spectra showed that a camera based on a 30-mm-thick BGO crystal and equipped with a high energy pinhole collimator is well-adapted to bremsstrahlung imaging. The total scatter contamination is reduced by a factor 10 versus a conventional NaI camera equipped with a high energy parallel hole collimator enabling acquisition using an extended energy window ranging from 50 to 350 keV. By using the recorded event energy in the reconstruction method, shorter acquisition time and reduced orbit range will be usable allowing the design of a simplified mobile gantry. This is more convenient for use in a busy catheterization room. After injecting a safe activity, a fast single photon emission computed tomography could be performed without moving the catheter tip in order to assess the liver dosimetry and estimate the additional safe activity that could still be injected. Further long running time MC simulations of realistic acquisitions will allow assessing the quantification capability of such system. Simultaneously, a dedicated bremsstrahlung prototype camera reusing PMT–BGO blocks coming from a retired PET system is currently under design for further evaluation. PMID:24982849

  6. A sinogram warping strategy for pre-reconstruction 4D PET optimization.

    PubMed

    Gianoli, Chiara; Riboldi, Marco; Fontana, Giulia; Kurz, Christopher; Parodi, Katia; Baroni, Guido

    2016-03-01

    A novel strategy for 4D PET optimization in the sinogram domain is proposed, aiming at motion model application before image reconstruction ("sinogram warping" strategy). Compared to state-of-the-art 4D-MLEM reconstruction, the proposed strategy is able to optimize the image SNR, avoiding iterative direct and inverse warping procedures, which are typical of the 4D-MLEM algorithm. A full-count statistics sinogram of the motion-compensated 4D PET reference phase is generated by warping the sinograms corresponding to the different PET phases. This is achieved relying on a motion model expressed in the sinogram domain. The strategy was tested on the anthropomorphic 4D PET-CT NCAT phantom in comparison with the 4D-MLEM algorithm, with particular reference to robustness to PET-CT co-registrations artefacts. The MLEM reconstruction of the warped sinogram according to the proposed strategy exhibited better accuracy (up to +40.90 % with respect to the ideal value), whereas images reconstructed according to the 4D-MLEM reconstruction resulted in less noisy (down to -26.90 % with respect to the ideal value) but more blurred. The sinogram warping strategy demonstrates advantages with respect to 4D-MLEM algorithm. These advantages are paid back by introducing approximation of the deformation field, and further efforts are required to mitigate the impact of such an approximation in clinical 4D PET reconstruction.

  7. Optimization of image reconstruction for yttrium-90 SIRT on a LYSO PET/CT system using a Bayesian penalized likelihood reconstruction algorithm.

    PubMed

    Rowley, Lisa M; Bradley, Kevin M; Boardman, Philip; Hallam, Aida; McGowan, Daniel R

    2016-09-29

    Imaging on a gamma camera with Yttrium-90 ((90)Y) following selective internal radiotherapy (SIRT) may allow for verification of treatment delivery but suffers relatively poor spatial resolution and imprecise dosimetry calculation. (90)Y Positron Emission Tomography (PET) / Computed Tomography (CT) imaging is possible on 3D, time-of-flight machines however images are usually poor due to low count statistics and noise. A new PET reconstruction software using a Bayesian penalized likelihood (BPL) reconstruction algorithm (termed Q.Clear) released by GE was investigated using phantom and patient scans to optimize the reconstruction for post-SIRT imaging and clarify if this leads to an improvement in clinical image quality using (90)Y.

  8. Optimized dynamic framing for PET-based myocardial blood flow estimation

    NASA Astrophysics Data System (ADS)

    Kolthammer, Jeffrey A.; Muzic, Raymond F.

    2013-08-01

    An optimal experiment design methodology was developed to select the framing schedule to be used in dynamic positron emission tomography (PET) for estimation of myocardial blood flow using 82Rb. A compartment model and an arterial input function based on measured data were used to calculate a D-optimality criterion for a wide range of candidate framing schedules. To validate the optimality calculation, noisy time-activity curves were simulated, from which parameter values were estimated using an efficient and robust decomposition of the estimation problem. D-optimized schedules improved estimate precision compared to non-optimized schedules, including previously published schedules. To assess robustness, a range of physiologic conditions were simulated. Schedules that were optimal for one condition were nearly-optimal for others. The effect of infusion duration was investigated. Optimality was better for shorter than for longer tracer infusion durations, with the optimal schedule for the shortest infusion duration being nearly optimal for other durations. Together this suggests that a framing schedule optimized for one set of conditions will also work well for others and it is not necessary to use different schedules for different infusion durations or for rest and stress studies. The method for optimizing schedules is general and could be applied in other dynamic PET imaging studies.

  9. Optimizing modelling in iterative image reconstruction for preclinical pinhole PET

    NASA Astrophysics Data System (ADS)

    Goorden, Marlies C.; van Roosmalen, Jarno; van der Have, Frans; Beekman, Freek J.

    2016-05-01

    The recently developed versatile emission computed tomography (VECTor) technology enables high-energy SPECT and simultaneous SPECT and PET of small animals at sub-mm resolutions. VECTor uses dedicated clustered pinhole collimators mounted in a scanner with three stationary large-area NaI(Tl) gamma detectors. Here, we develop and validate dedicated image reconstruction methods that compensate for image degradation by incorporating accurate models for the transport of high-energy annihilation gamma photons. Ray tracing software was used to calculate photon transport through the collimator structures and into the gamma detector. Input to this code are several geometric parameters estimated from system calibration with a scanning 99mTc point source. Effects on reconstructed images of (i) modelling variable depth-of-interaction (DOI) in the detector, (ii) incorporating photon paths that go through multiple pinholes (‘multiple-pinhole paths’ (MPP)), and (iii) including various amounts of point spread function (PSF) tail were evaluated. Imaging 18F in resolution and uniformity phantoms showed that including large parts of PSFs is essential to obtain good contrast-noise characteristics and that DOI modelling is highly effective in removing deformations of small structures, together leading to 0.75 mm resolution PET images of a hot-rod Derenzo phantom. Moreover, MPP modelling reduced the level of background noise. These improvements were also clearly visible in mouse images. Performance of VECTor can thus be significantly improved by accurately modelling annihilation gamma photon transport.

  10. Vehicle occupancy detection camera position optimization using design of experiments and standard image references

    NASA Astrophysics Data System (ADS)

    Paul, Peter; Hoover, Martin; Rabbani, Mojgan

    2013-03-01

    Camera positioning and orientation is important to applications in domains such as transportation since the objects to be imaged vary greatly in shape and size. In a typical transportation application that requires capturing still images, inductive loops buried in the ground or laser trigger sensors are used when a vehicle reaches the image capture zone to trigger the image capture system. The camera in such a system is in a fixed position pointed at the roadway and at a fixed orientation. Thus the problem is to determine the optimal location and orientation of the camera when capturing images from a wide variety of vehicles. Methods from Design for Six Sigma, including identifying important parameters and noise sources and performing systematically designed experiments (DOE) can be used to determine an effective set of parameter settings for the camera position and orientation under these conditions. In the transportation application of high occupancy vehicle lane enforcement, the number of passengers in the vehicle is to be counted. Past work has described front seat vehicle occupant counting using a camera mounted on an overhead gantry looking through the front windshield in order to capture images of vehicle occupants. However, viewing rear seat passengers is more problematic due to obstructions including the vehicle body frame structures and seats. One approach is to view the rear seats through the side window. In this situation the problem of optimally positioning and orienting the camera to adequately capture the rear seats through the side window can be addressed through a designed experiment. In any automated traffic enforcement system it is necessary for humans to be able to review any automatically captured digital imagery in order to verify detected infractions. Thus for defining an output to be optimized for the designed experiment, a human defined standard image reference (SIR) was used to quantify the quality of the line-of-sight to the rear seats of

  11. Optimization of light field display-camera configuration based on display properties in spectral domain.

    PubMed

    Bregović, Robert; Kovács, Péter Tamás; Gotchev, Atanas

    2016-02-08

    The visualization capability of a light field display is uniquely determined by its angular and spatial resolution referred to as display passband. In this paper we use a multidimensional sampling model for describing the display-camera channel. Based on the model, for a given display passband, we propose a methodology for determining the optimal distribution of ray generators in a projection-based light field display. We also discuss the required camera setup that can provide data with the necessary amount of details for such display that maximizes the visual quality and minimizes the amount of data.

  12. Optimal feature selection for automated classification of FDG-PET in patients with suspected dementia

    NASA Astrophysics Data System (ADS)

    Serag, Ahmed; Wenzel, Fabian; Thiele, Frank; Buchert, Ralph; Young, Stewart

    2009-02-01

    FDG-PET is increasingly used for the evaluation of dementia patients, as major neurodegenerative disorders, such as Alzheimer's disease (AD), Lewy body dementia (LBD), and Frontotemporal dementia (FTD), have been shown to induce specific patterns of regional hypo-metabolism. However, the interpretation of FDG-PET images of patients with suspected dementia is not straightforward, since patients are imaged at different stages of progression of neurodegenerative disease, and the indications of reduced metabolism due to neurodegenerative disease appear slowly over time. Furthermore, different diseases can cause rather similar patterns of hypo-metabolism. Therefore, classification of FDG-PET images of patients with suspected dementia may lead to misdiagnosis. This work aims to find an optimal subset of features for automated classification, in order to improve classification accuracy of FDG-PET images in patients with suspected dementia. A novel feature selection method is proposed, and performance is compared to existing methods. The proposed approach adopts a combination of balanced class distributions and feature selection methods. This is demonstrated to provide high classification accuracy for classification of FDG-PET brain images of normal controls and dementia patients, comparable with alternative approaches, and provides a compact set of features selected.

  13. Multiobjective optimization of an industrial wiped-film PET reactor

    SciTech Connect

    Bhaskar, V.; Gupta, S.K.; Ray, A.K.

    2000-05-01

    Multiobjective optimization of a third-stage, wiped-film polyester reactor was carried out using a model that describes an industrial poly(ethylene terephthalate) reactor quite well. The two objective functions minimized are the acid and vinyl end group concentrations in the product. These are two of the undesirable side products produced in the reactor. The optimization-problem incorporates an endpoint constraint to produce a polymer with a desired value of the degree of polymerization. In addition, the concentration of the di-ethylene glycol end group in the product is constrained to lie within a certain range of values. Adaptations of the nondominated sorting genetic algorithm have been developed to obtain optimal values of the five decision variables: reactor pressure, temperature, catalyst concentration, residence time of the polymer inside the reactor, and the speed of the agitator. The optimal solution was a unique point (no Pareto set obtained). Problems of multiplicity and premature convergence were encountered. A smoothening procedure is suggested to generate near-optimal operating conditions. The optimal solution corresponds simultaneously to minimum values of the residence time of the polymeric reaction mass in the reactor.

  14. Flow optimization study of a batch microfluidics PET tracer synthesizing device

    PubMed Central

    Elizarov, Arkadij M.; Meinhart, Carl; van Dam, R. Michael; Huang, Jiang; Daridon, Antoine; Heath, James R.; Kolb, Hartmuth C.

    2010-01-01

    We present numerical modeling and experimental studies of flow optimization inside a batch microfluidic micro-reactor used for synthesis of human-scale doses of Positron Emission Tomography (PET) tracers. Novel techniques are used for mixing within, and eluting liquid out of, the coin-shaped reaction chamber. Numerical solutions of the general incompressible Navier Stokes equations along with time-dependent elution scalar field equation for the three dimensional coin-shaped geometry were obtained and validated using fluorescence imaging analysis techniques. Utilizing the approach presented in this work, we were able to identify optimized geometrical and operational conditions for the micro-reactor in the absence of radioactive material commonly used in PET related tracer production platforms as well as evaluate the designed and fabricated micro-reactor using numerical and experimental validations. PMID:21072595

  15. Edge-preserving PET image reconstruction using trust optimization transfer.

    PubMed

    Wang, Guobao; Qi, Jinyi

    2015-04-01

    Iterative image reconstruction for positron emission tomography can improve image quality by using spatial regularization. The most commonly used quadratic penalty often oversmoothes sharp edges and fine features in reconstructed images, while nonquadratic penalties can preserve edges and achieve higher contrast recovery. Existing optimization algorithms such as the expectation maximization (EM) and preconditioned conjugate gradient (PCG) algorithms work well for the quadratic penalty, but are less efficient for high-curvature or nonsmooth edge-preserving regularizations. This paper proposes a new algorithm to accelerate edge-preserving image reconstruction by using two strategies: trust surrogate and optimization transfer descent. Trust surrogate approximates the original penalty by a smoother function at each iteration, but guarantees the algorithm to descend monotonically; Optimization transfer descent accelerates a conventional optimization transfer algorithm by using conjugate gradient and line search. Results of computer simulations and real 3-D data show that the proposed algorithm converges much faster than the conventional EM and PCG for smooth edge-preserving regularization and can also be more efficient than the current state-of-art algorithms for the nonsmooth l1 regularization.

  16. A neutron pinhole camera for PF-24 source: Conceptual design and optimization

    NASA Astrophysics Data System (ADS)

    Bielecki, J.; Wójcik-Gargula, A.; Wiacek, U.; Scholz, M.; Igielski, A.; Drozdowicz, K.; Woźnicka, U.

    2015-07-01

    A fast-neutron pinhole camera based on small-area (5mm × 5 mm) BCF-12 scintillation detectors with nanosecond time resolution has been designed. The pinhole camera is dedicated to the investigation of the spatial and temporal distributions of DD neutrons from the Plasma Focus (PF-24) source. The geometrical parameters of the camera have been optimized in terms of maximum neutron flux at the imaging plane by means of MCNP calculations. The detection system consists of four closely packed scintillation detectors coupled via long optical fibres to Hamamatsu H3164-10 photomultiplier tubes. The pinhole consists of specially designed 420 mm long copper collimator with an effective aperture of 1.7 mm mounted inside a cylindrical polyethylene tube. The performance of the presented detection system in the mixed (hard X-ray and neutron) radiation field of the PF-24 plasma focus device has been tested. The results of the tests showed that the small-area BCF-12 scintillation detectors can be successfully applied as the detection system of the neutron pinhole camera for the PF-24 device.

  17. SU-D-9A-01: Listmode-Driven Optimal Gating (OG) Respiratory Motion Management: Potential Impact On Quantitative PET Imaging

    SciTech Connect

    Lee, K; Hristov, D

    2014-06-01

    Purpose: To evaluate the potential impact of listmode-driven amplitude based optimal gating (OG) respiratory motion management technique on quantitative PET imaging. Methods: During the PET acquisitions, an optical camera tracked and recorded the motion of a tool placed on top of patients' torso. PET event data were utilized to detect and derive a motion signal that is directly coupled with a specific internal organ. A radioactivity-trace was generated from listmode data by accumulating all prompt counts in temporal bins matching the sampling rate of the external tracking device. Decay correction for 18F was performed. The image reconstructions using OG respiratory motion management technique that uses 35% of total radioactivity counts within limited motion amplitudes were performed with external motion and radioactivity traces separately with ordered subset expectation maximization (OSEM) with 2 iterations and 21 subsets. Standard uptake values (SUVs) in a tumor region were calculated to measure the effect of using radioactivity trace for motion compensation. Motion-blurred 3D static PET image was also reconstructed with all counts and the SUVs derived from OG images were compared with SUVs from 3D images. Results: A 5.7 % increase of the maximum SUV in the lesion was found for optimal gating image reconstruction with radioactivity trace when compared to a static 3D image. The mean and maximum SUVs on the image that was reconstructed with radioactivity trace were found comparable (0.4 % and 4.5 % increase, respectively) to the values derived from the image that was reconstructed with external trace. Conclusion: The image reconstructed using radioactivity trace showed that the blurring due to the motion was reduced with impact on derived SUVs. The resolution and contrast of the images reconstructed with radioactivity trace were comparable to the resolution and contrast of the images reconstructed with external respiratory traces. Research supported by Siemens.

  18. Optimized MLAA for quantitative non-TOF PET/MR of the brain

    NASA Astrophysics Data System (ADS)

    Benoit, Didier; Ladefoged, Claes N.; Rezaei, Ahmadreza; Keller, Sune H.; Andersen, Flemming L.; Højgaard, Liselotte; Hansen, Adam E.; Holm, Søren; Nuyts, Johan

    2016-12-01

    For quantitative tracer distribution in positron emission tomography, attenuation correction is essential. In a hybrid PET/CT system the CT images serve as a basis for generation of the attenuation map, but in PET/MR, the MR images do not have a similarly simple relationship with the attenuation map. Hence attenuation correction in PET/MR systems is more challenging. Typically either of two MR sequences are used: the Dixon or the ultra-short time echo (UTE) techniques. However these sequences have some well-known limitations. In this study, a reconstruction technique based on a modified and optimized non-TOF MLAA is proposed for PET/MR brain imaging. The idea is to tune the parameters of the MLTR applying some information from an attenuation image computed from the UTE sequences and a T1w MR image. In this MLTR algorithm, an {αj} parameter is introduced and optimized in order to drive the algorithm to a final attenuation map most consistent with the emission data. Because the non-TOF MLAA is used, a technique to reduce the cross-talk effect is proposed. In this study, the proposed algorithm is compared to the common reconstruction methods such as OSEM using a CT attenuation map, considered as the reference, and OSEM using the Dixon and UTE attenuation maps. To show the robustness and the reproducibility of the proposed algorithm, a set of 204 [18F]FDG patients, 35 [11C]PiB patients and 1 [18F]FET patient are used. The results show that by choosing an optimized value of {αj} in MLTR, the proposed algorithm improves the results compared to the standard MR-based attenuation correction methods (i.e. OSEM using the Dixon or the UTE attenuation maps), and the cross-talk and the scale problem are limited.

  19. Optimization of camera exposure durations for multi-exposure speckle imaging of the microcirculation

    PubMed Central

    Kazmi, S. M. Shams; Balial, Satyajit; Dunn, Andrew K.

    2014-01-01

    Improved Laser Speckle Contrast Imaging (LSCI) blood flow analyses that incorporate inverse models of the underlying laser-tissue interaction have been used to develop more quantitative implementations of speckle flowmetry such as Multi-Exposure Speckle Imaging (MESI). In this paper, we determine the optimal camera exposure durations required for obtaining flow information with comparable accuracy with the prevailing MESI implementation utilized in recent in vivo rodent studies. A looping leave-one-out (LOO) algorithm was used to identify exposure subsets which were analyzed for accuracy against flows obtained from analysis with the original full exposure set over 9 animals comprising n = 314 regional flow measurements. From the 15 original exposures, 6 exposures were found using the LOO process to provide comparable accuracy, defined as being no more than 10% deviant, with the original flow measurements. The optimal subset of exposures provides a basis set of camera durations for speckle flowmetry studies of the microcirculation and confers a two-fold faster acquisition rate and a 28% reduction in processing time without sacrificing accuracy. Additionally, the optimization process can be used to identify further reductions in the exposure subsets for tailoring imaging over less expansive flow distributions to enable even faster imaging. PMID:25071956

  20. Motion correction of PET brain images through deconvolution: II. Practical implementation and algorithm optimization

    NASA Astrophysics Data System (ADS)

    Raghunath, N.; Faber, T. L.; Suryanarayanan, S.; Votaw, J. R.

    2009-02-01

    Image quality is significantly degraded even by small amounts of patient motion in very high-resolution PET scanners. When patient motion is known, deconvolution methods can be used to correct the reconstructed image and reduce motion blur. This paper describes the implementation and optimization of an iterative deconvolution method that uses an ordered subset approach to make it practical and clinically viable. We performed ten separate FDG PET scans using the Hoffman brain phantom and simultaneously measured its motion using the Polaris Vicra tracking system (Northern Digital Inc., Ontario, Canada). The feasibility and effectiveness of the technique was studied by performing scans with different motion and deconvolution parameters. Deconvolution resulted in visually better images and significant improvement as quantified by the Universal Quality Index (UQI) and contrast measures. Finally, the technique was applied to human studies to demonstrate marked improvement. Thus, the deconvolution technique presented here appears promising as a valid alternative to existing motion correction methods for PET. It has the potential for deblurring an image from any modality if the causative motion is known and its effect can be represented in a system matrix.

  1. Dynamic whole-body PET parametric imaging: I. Concept, acquisition protocol optimization and clinical application

    NASA Astrophysics Data System (ADS)

    Karakatsanis, Nicolas A.; Lodge, Martin A.; Tahari, Abdel K.; Zhou, Y.; Wahl, Richard L.; Rahmim, Arman

    2013-10-01

    Static whole-body PET/CT, employing the standardized uptake value (SUV), is considered the standard clinical approach to diagnosis and treatment response monitoring for a wide range of oncologic malignancies. Alternative PET protocols involving dynamic acquisition of temporal images have been implemented in the research setting, allowing quantification of tracer dynamics, an important capability for tumor characterization and treatment response monitoring. Nonetheless, dynamic protocols have been confined to single-bed-coverage limiting the axial field-of-view to ˜15-20 cm, and have not been translated to the routine clinical context of whole-body PET imaging for the inspection of disseminated disease. Here, we pursue a transition to dynamic whole-body PET parametric imaging, by presenting, within a unified framework, clinically feasible multi-bed dynamic PET acquisition protocols and parametric imaging methods. We investigate solutions to address the challenges of: (i) long acquisitions, (ii) small number of dynamic frames per bed, and (iii) non-invasive quantification of kinetics in the plasma. In the present study, a novel dynamic (4D) whole-body PET acquisition protocol of ˜45 min total length is presented, composed of (i) an initial 6 min dynamic PET scan (24 frames) over the heart, followed by (ii) a sequence of multi-pass multi-bed PET scans (six passes × seven bed positions, each scanned for 45 s). Standard Patlak linear graphical analysis modeling was employed, coupled with image-derived plasma input function measurements. Ordinary least squares Patlak estimation was used as the baseline regression method to quantify the physiological parameters of tracer uptake rate Ki and total blood distribution volume V on an individual voxel basis. Extensive Monte Carlo simulation studies, using a wide set of published kinetic FDG parameters and GATE and XCAT platforms, were conducted to optimize the acquisition protocol from a range of ten different clinically

  2. A non-linear camera calibration with modified teaching-learning-based optimization algorithm

    NASA Astrophysics Data System (ADS)

    Zhang, Buyang; Yang, Hua; Yang, Shuo

    2015-12-01

    In this paper, we put forward a novel approach based on hierarchical teaching-and-learning-based optimization (HTLBO) algorithm for nonlinear camera calibration. This algorithm simulates the teaching-learning ability of teachers and learners of a classroom. Different from traditional calibration approach, the proposed technique can find the nearoptimal solution without the need of accurate initial parameters estimation (with only very loose parameter bounds). With the introduction of cascade of teaching, the convergence speed is rapid and the global search ability is improved. Results from our study demonstrate the excellent performance of the proposed technique in terms of convergence, accuracy, and robustness. The HTLBO can also be used to solve many other complex non-linear calibration optimization problems for its good portability.

  3. Optimization of Rb-82 PET acquisition and reconstruction protocols for myocardial perfusion defect detection

    NASA Astrophysics Data System (ADS)

    Tang, Jing; Rahmim, Arman; Lautamäki, Riikka; Lodge, Martin A.; Bengel, Frank M.; Tsui, Benjamin M. W.

    2009-05-01

    The purpose of this study is to optimize the dynamic Rb-82 cardiac PET acquisition and reconstruction protocols for maximum myocardial perfusion defect detection using realistic simulation data and task-based evaluation. Time activity curves (TACs) of different organs under both rest and stress conditions were extracted from dynamic Rb-82 PET images of five normal patients. Combined SimSET-GATE Monte Carlo simulation was used to generate nearly noise-free cardiac PET data from a time series of 3D NCAT phantoms with organ activities modeling different pre-scan delay times (PDTs) and total acquisition times (TATs). Poisson noise was added to the nearly noise-free projections and the OS-EM algorithm was applied to generate noisy reconstructed images. The channelized Hotelling observer (CHO) with 32× 32 spatial templates corresponding to four octave-wide frequency channels was used to evaluate the images. The area under the ROC curve (AUC) was calculated from the CHO rating data as an index for image quality in terms of myocardial perfusion defect detection. The 0.5 cycle cm-1 Butterworth post-filtering on OS-EM (with 21 subsets) reconstructed images generates the highest AUC values while those from iteration numbers 1 to 4 do not show different AUC values. The optimized PDTs for both rest and stress conditions are found to be close to the cross points of the left ventricular chamber and myocardium TACs, which may promote an individualized PDT for patient data processing and image reconstruction. Shortening the TATs for <~3 min from the clinically employed acquisition time does not affect the myocardial perfusion defect detection significantly for both rest and stress studies.

  4. An energy-optimized collimator design for a CZT-based SPECT camera

    PubMed Central

    Weng, Fenghua; Bagchi, Srijeeta; Zan, Yunlong; Huang, Qiu; Seo, Youngho

    2015-01-01

    In single photon emission computed tomography, it is a challenging task to maintain reasonable performance using only one specific collimator for radio-tracers over a broad spectrum of diagnostic photon energies, since photon scatter and penetration in a collimator differ with the photon energy. Frequent collimator exchanges are inevitable in daily clinical SPECT imaging, which hinders throughput while subjecting the camera to operational errors and damage. Our objective is to design a collimator, which independent of the photon energy performs reasonably well for commonly used radiotracers with low- to medium-energy levels of gamma emissions. Using the Geant4 simulation toolkit, we simulated and evaluated a parallel-hole collimator mounted to a CZT detector. With the pixel-geometry-matching collimation, the pitch of the collimator hole was fixed to match the pixel size of the CZT detector throughout this work. Four variables, hole shape, hole length, hole radius/width and the source-to-collimator distance were carefully studied. Scatter and penetration of the collimator, sensitivity and spatial resolution of the system were assessed for four radionuclides including 57Co, 99mTc, 123I and 111In, with respect to the aforementioned four variables. An optimal collimator was then decided upon such that it maximized the total relative sensitivity (TRS) for the four considered radionuclides while other performance parameters, such as scatter, penetration and spatial resolution, were benchmarked to prevalent commercial scanners and collimators. Digital phantom studies were also performed to validate the system with the optimal square-hole collimator (23 mm hole length, 1.28 mm hole width, 0.32 mm septal thickness) in terms of contrast, contrast-to-noise ratio and recovery ratio. This study demonstrates promise of our proposed energy-optimized collimator to be used in a CZT-based gamma camera, with comparable or even better imaging performance versus commercial collimators

  5. An energy-optimized collimator design for a CZT-based SPECT camera

    NASA Astrophysics Data System (ADS)

    Weng, Fenghua; Bagchi, Srijeeta; Zan, Yunlong; Huang, Qiu; Seo, Youngho

    2016-01-01

    In single photon emission computed tomography, it is a challenging task to maintain reasonable performance using only one specific collimator for radiotracers over a broad spectrum of diagnostic photon energies, since photon scatter and penetration in a collimator differ with the photon energy. Frequent collimator exchanges are inevitable in daily clinical SPECT imaging, which hinders throughput while subjecting the camera to operational errors and damage. Our objective is to design a collimator, which is independent of the photon energy, performs reasonably well for commonly used radiotracers with low- to medium-energy levels of gamma emissions. Using the Geant4 simulation toolkit, we simulated and evaluated a parallel-hole collimator mounted to a CZT detector. With the pixel-geometry-matching collimation, the pitch of the collimator hole was fixed to match the pixel size of the CZT detector throughout this work. Four variables, hole shape, hole length, hole radius/width and the source-to-collimator distance were carefully studied. Scatter and penetration of the collimator, sensitivity and spatial resolution of the system were assessed for four radionuclides including 57Co, 99mTc, 123I and 111In, with respect to the aforementioned four variables. An optimal collimator was then decided upon such that it maximized the total relative sensitivity (TRS) for the four considered radionuclides while other performance parameters, such as scatter, penetration and spatial resolution, were benchmarked to prevalent commercial scanners and collimators. Digital phantom studies were also performed to validate the system with the optimal square-hole collimator (23 mm hole length, 1.28 mm hole width, and 0.32 mm septal thickness) in terms of contrast, contrast-to-noise ratio and recovery ratio. This study demonstrates promise of our proposed energy-optimized collimator to be used in a CZT-based gamma camera, with comparable or even better imaging performance versus commercial

  6. Optimization of radiation doses received by personnel in PET uptake rooms.

    PubMed

    Perez, Maria E; Verde, José M; Montes, Carlos; Ramos, Julio A; García, Sofía; Hernandez, Jorge

    2014-11-01

    Reduction of dose to exposed personnel during positron emission tomography (PET) installation usually relies on physical shielding. While the major contribution of shielding is unquestioned, it is usually the only method applied. Other methods of reduction, such as working procedure optimization, the position of the furniture, and rooms are usually disregarded in these installations. This paper presents a design and work optimization procedure used in a particular institution. The influence on the dose received by personnel due to the positioning of injection chairs, injection room configuration, and working procedures is studied. Using this optimization strategy, it is possible to reduce the technician dose due to patients by a factor of 0.59. Injection room design is much more important for optimizing the received dose than is work-flow management. The influence of the order of patient entrance on received dose was the aspect that produced the smallest variation in received doses. It is recommended that the optimization be carried out for the installation proposed in the design phase, when no additional cost is required, because the position of the doors of the injection rooms depends on the where the injection chairs are situated.

  7. Dual-Modality PET/Ultrasound imaging of the Prostate

    SciTech Connect

    Huber, Jennifer S.; Moses, William W.; Pouliot, Jean; Hsu, I.C.

    2005-11-11

    Functional imaging with positron emission tomography (PET)will detect malignant tumors in the prostate and/or prostate bed, as well as possibly help determine tumor ''aggressiveness''. However, the relative uptake in a prostate tumor can be so great that few other anatomical landmarks are visible in a PET image. Ultrasound imaging with a transrectal probe provides anatomical detail in the prostate region that can be co-registered with the sensitive functional information from the PET imaging. Imaging the prostate with both PET and transrectal ultrasound (TRUS) will help determine the location of any cancer within the prostate region. This dual-modality imaging should help provide better detection and treatment of prostate cancer. LBNL has built a high performance positron emission tomograph optimized to image the prostate.Compared to a standard whole-body PET camera, our prostate-optimized PET camera has the same sensitivity and resolution, less backgrounds and lower cost. We plan to develop the hardware and software tools needed for a validated dual PET/TRUS prostate imaging system. We also plan to develop dual prostate imaging with PET and external transabdominal ultrasound, in case the TRUS system is too uncomfortable for some patients. We present the design and intended clinical uses for these dual imaging systems.

  8. Study and optimization of positioning algorithms for monolithic PET detectors blocks

    NASA Astrophysics Data System (ADS)

    Garcia de Acilu, P.; Sarasola, I.; Canadas, M.; Cuerdo, R.; Rato Mendes, P.; Romero, L.; Willmott, C.

    2012-06-01

    We are developing a PET insert for existing MRI equipment to be used in clinical PET/MR studies of the human brain. The proposed scanner is based on annihilation gamma detection with monolithic blocks of cerium-doped lutetium yttrium orthosilicate (LYSO:Ce) coupled to magnetically-compatible avalanche photodiodes (APD) matrices. The light distribution generated on the LYSO:Ce block provides the impinging position of the 511 keV photons by means of a positioning algorithm. Several positioning methods, from the simplest Anger Logic to more sophisticate supervised-learning Neural Networks (NN), can be implemented to extract the incidence position of gammas directly from the APD signals. Finally, an optimal method based on a two-step Feed-Forward Neural Network has been selected. It allows us to reach a resolution at detector level of 2 mm, and acquire images of point sources using a first BrainPET prototype consisting of two monolithic blocks working in coincidence. Neural networks provide a straightforward positioning of the acquired data once they have been trained, however the training process is usually time-consuming. In order to obtain an efficient positioning method for the complete scanner it was necessary to find a training procedure that reduces the data acquisition and processing time without introducing a noticeable degradation of the spatial resolution. A grouping process and posterior selection of the training data have been done regarding the similitude of the light distribution of events which have one common incident coordinate (transversal or longitudinal). By doing this, the amount of training data can be reduced to about 5% of the initial number with a degradation of spatial resolution lower than 10%.

  9. Optimization, evaluation, and comparison of standard algorithms for image reconstruction with the VIP-PET.

    PubMed

    Mikhaylova, E; Kolstein, M; De Lorenzo, G; Chmeissani, M

    2014-07-01

    A novel positron emission tomography (PET) scanner design based on a room-temperature pixelated CdTe solid-state detector is being developed within the framework of the Voxel Imaging PET (VIP) Pathfinder project [1]. The simulation results show a great potential of the VIP to produce high-resolution images even in extremely challenging conditions such as the screening of a human head [2]. With unprecedented high channel density (450 channels/cm(3)) image reconstruction is a challenge. Therefore optimization is needed to find the best algorithm in order to exploit correctly the promising detector potential. The following reconstruction algorithms are evaluated: 2-D Filtered Backprojection (FBP), Ordered Subset Expectation Maximization (OSEM), List-Mode OSEM (LM-OSEM), and the Origin Ensemble (OE) algorithm. The evaluation is based on the comparison of a true image phantom with a set of reconstructed images obtained by each algorithm. This is achieved by calculation of image quality merit parameters such as the bias, the variance and the mean square error (MSE). A systematic optimization of each algorithm is performed by varying the reconstruction parameters, such as the cutoff frequency of the noise filters and the number of iterations. The region of interest (ROI) analysis of the reconstructed phantom is also performed for each algorithm and the results are compared. Additionally, the performance of the image reconstruction methods is compared by calculating the modulation transfer function (MTF). The reconstruction time is also taken into account to choose the optimal algorithm. The analysis is based on GAMOS [3] simulation including the expected CdTe and electronic specifics.

  10. Optimization, evaluation, and comparison of standard algorithms for image reconstruction with the VIP-PET

    NASA Astrophysics Data System (ADS)

    Mikhaylova, E.; Kolstein, M.; De Lorenzo, G.; Chmeissani, M.

    2014-07-01

    A novel positron emission tomography (PET) scanner design based on a room-temperature pixelated CdTe solid-state detector is being developed within the framework of the Voxel Imaging PET (VIP) Pathfinder project [1]. The simulation results show a great potential of the VIP to produce high-resolution images even in extremely challenging conditions such as the screening of a human head [2]. With unprecedented high channel density (450 channels/cm3) image reconstruction is a challenge. Therefore optimization is needed to find the best algorithm in order to exploit correctly the promising detector potential. The following reconstruction algorithms are evaluated: 2-D Filtered Backprojection (FBP), Ordered Subset Expectation Maximization (OSEM), List-Mode OSEM (LM-OSEM), and the Origin Ensemble (OE) algorithm. The evaluation is based on the comparison of a true image phantom with a set of reconstructed images obtained by each algorithm. This is achieved by calculation of image quality merit parameters such as the bias, the variance and the mean square error (MSE). A systematic optimization of each algorithm is performed by varying the reconstruction parameters, such as the cutoff frequency of the noise filters and the number of iterations. The region of interest (ROI) analysis of the reconstructed phantom is also performed for each algorithm and the results are compared. Additionally, the performance of the image reconstruction methods is compared by calculating the modulation transfer function (MTF). The reconstruction time is also taken into account to choose the optimal algorithm. The analysis is based on GAMOS [3] simulation including the expected CdTe and electronic specifics.

  11. Optimization, evaluation, and comparison of standard algorithms for image reconstruction with the VIP-PET

    PubMed Central

    Mikhaylova, E.; Kolstein, M.; De Lorenzo, G.; Chmeissani, M.

    2014-01-01

    A novel positron emission tomography (PET) scanner design based on a room-temperature pixelated CdTe solid-state detector is being developed within the framework of the Voxel Imaging PET (VIP) Pathfinder project [1]. The simulation results show a great potential of the VIP to produce high-resolution images even in extremely challenging conditions such as the screening of a human head [2]. With unprecedented high channel density (450 channels/cm3) image reconstruction is a challenge. Therefore optimization is needed to find the best algorithm in order to exploit correctly the promising detector potential. The following reconstruction algorithms are evaluated: 2-D Filtered Backprojection (FBP), Ordered Subset Expectation Maximization (OSEM), List-Mode OSEM (LM-OSEM), and the Origin Ensemble (OE) algorithm. The evaluation is based on the comparison of a true image phantom with a set of reconstructed images obtained by each algorithm. This is achieved by calculation of image quality merit parameters such as the bias, the variance and the mean square error (MSE). A systematic optimization of each algorithm is performed by varying the reconstruction parameters, such as the cutoff frequency of the noise filters and the number of iterations. The region of interest (ROI) analysis of the reconstructed phantom is also performed for each algorithm and the results are compared. Additionally, the performance of the image reconstruction methods is compared by calculating the modulation transfer function (MTF). The reconstruction time is also taken into account to choose the optimal algorithm. The analysis is based on GAMOS [3] simulation including the expected CdTe and electronic specifics. PMID:25018777

  12. SU-D-201-05: Phantom Study to Determine Optimal PET Reconstruction Parameters for PET/MR Imaging of Y-90 Microspheres Following Radioembolization

    SciTech Connect

    Maughan, N; Conti, M; Parikh, P; Faul, D; Laforest, R

    2015-06-15

    Purpose: Imaging Y-90 microspheres with PET/MRI following hepatic radioembolization has the potential for predicting treatment outcome and, in turn, improving patient care. The positron decay branching ratio, however, is very small (32 ppm), yielding images with poor statistics even when therapy doses are used. Our purpose is to find PET reconstruction parameters that maximize the PET recovery coefficients and minimize noise. Methods: An initial 7.5 GBq of Y-90 chloride solution was used to fill an ACR phantom for measurements with a PET/MRI scanner (Siemens Biograph mMR). Four hot cylinders and a warm background activity volume of the phantom were filled with a 10:1 ratio. Phantom attenuation maps were derived from scaled CT images of the phantom and included the MR phased array coil. The phantom was imaged at six time points between 7.5–1.0 GBq total activity over a period of eight days. PET images were reconstructed via OP-OSEM with 21 subsets and varying iteration number (1–5), post-reconstruction filter size (5–10 mm), and either absolute or relative scatter correction. Recovery coefficients, SNR, and noise were measured as well as total activity in the phantom. Results: For the 120 different reconstructions, recovery coefficients ranged from 0.1–0.6 and improved with increasing iteration number and reduced post-reconstruction filter size. SNR, however, improved substantially with lower iteration numbers and larger post-reconstruction filters. From the phantom data, we found that performing 2 iterations, 21 subsets, and applying a 5 mm Gaussian post-reconstruction filter provided optimal recovery coefficients at a moderate noise level for a wide range of activity levels. Conclusion: The choice of reconstruction parameters for Y-90 PET images greatly influences both the accuracy of measurements and image quality. We have found reconstruction parameters that provide optimal recovery coefficients with minimized noise. Future work will include the effects

  13. Controlling Small Fixed Wing UAVs to Optimize Image Quality from On-Board Cameras

    NASA Astrophysics Data System (ADS)

    Jackson, Stephen Phillip

    Small UAVs have shown great promise as tools for collecting aerial imagery both quickly and cheaply. Furthermore, using a team of small UAVs, as opposed to one large UAV, has shown promise as being a cheaper, faster and more robust method for collecting image data over a large area. Unfortunately, the autonomy of small UAVs has not yet reached the point where they can be relied upon to collect good aerial imagery without human intervention, or supervision. The work presented here intends to increase the level of autonomy of small UAVs so that they can independently, and reliably collect quality aerial imagery. The main contribution of this paper is a novel approach to controlling small fixed wing UAVs that optimizes the quality of the images captured by cameras on board the aircraft. This main contribution is built on three minor contributions: a kinodynamic motion model for small fixed wing UAVs, an iterative Gaussian sampling strategy for rapidly exploring random trees, and a receding horizon, nonlinear model predictive controller for controlling a UAV's sensor footprint. The kinodynamic motion model is built on the traditional unicycle model of an aircraft. In order to create dynamically feasible paths, the kinodynamic motion model augments the kinetic unicycle model by adding a first order estimate of the aircraft's roll dynamics. Experimental data is presented that not only validates this novel kinodynamic motion model, but also shows a 25% improvement over the traditional unicycle model. A novel Gaussian biased sampling strategy is presented for building a rapidly exploring random tree that quickly iterates to a near optimal path. This novel sampling strategy does not require a method for calculating the nearest node to a point, which means that it runs much faster than the traditional RRT algorithm, but it still results in a Gaussian distribution of nodes. Furthermore, because it uses the kinodynamic motion model, the near optimal path it generates is, by

  14. Optimal camera exposure for video surveillance systems by predictive control of shutter speed, aperture, and gain

    NASA Astrophysics Data System (ADS)

    Torres, Juan; Menéndez, José Manuel

    2015-02-01

    This paper establishes a real-time auto-exposure method to guarantee that surveillance cameras in uncontrolled light conditions take advantage of their whole dynamic range while provide neither under nor overexposed images. State-of-the-art auto-exposure methods base their control on the brightness of the image measured in a limited region where the foreground objects are mostly located. Unlike these methods, the proposed algorithm establishes a set of indicators based on the image histogram that defines its shape and position. Furthermore, the location of the objects to be inspected is likely unknown in surveillance applications. Thus, the whole image is monitored in this approach. To control the camera settings, we defined a parameters function (Ef ) that linearly depends on the shutter speed and the electronic gain; and is inversely proportional to the square of the lens aperture diameter. When the current acquired image is not overexposed, our algorithm computes the value of Ef that would move the histogram to the maximum value that does not overexpose the capture. When the current acquired image is overexposed, it computes the value of Ef that would move the histogram to a value that does not underexpose the capture and remains close to the overexposed region. If the image is under and overexposed, the whole dynamic range of the camera is therefore used, and a default value of the Ef that does not overexpose the capture is selected. This decision follows the idea that to get underexposed images is better than to get overexposed ones, because the noise produced in the lower regions of the histogram can be removed in a post-processing step while the saturated pixels of the higher regions cannot be recovered. The proposed algorithm was tested in a video surveillance camera placed at an outdoor parking lot surrounded by buildings and trees which produce moving shadows in the ground. During the daytime of seven days, the algorithm was running alternatively together

  15. Fourier-based reconstruction for fully 3-D PET: optimization of interpolation parameters.

    PubMed

    Matej, Samuel; Kazantsev, Ivan G

    2006-07-01

    Fourier-based approaches for three-dimensional (3-D) reconstruction are based on the relationship between the 3-D Fourier transform (FT) of the volume and the two-dimensional (2-D) FT of a parallel-ray projection of the volume. The critical step in the Fourier-based methods is the estimation of the samples of the 3-D transform of the image from the samples of the 2-D transforms of the projections on the planes through the origin of Fourier space, and vice versa for forward-projection (reprojection). The Fourier-based approaches have the potential for very fast reconstruction, but their straightforward implementation might lead to unsatisfactory results if careful attention is not paid to interpolation and weighting functions. In our previous work, we have investigated optimal interpolation parameters for the Fourier-based forward and back-projectors for iterative image reconstruction. The optimized interpolation kernels were shown to provide excellent quality comparable to the ideal sinc interpolator. This work presents an optimization of interpolation parameters of the 3-D direct Fourier method with Fourier reprojection (3D-FRP) for fully 3-D positron emission tomography (PET) data with incomplete oblique projections. The reprojection step is needed for the estimation (from an initial image) of the missing portions of the oblique data. In the 3D-FRP implementation, we use the gridding interpolation strategy, combined with proper weighting approaches in the transform and image domains. We have found that while the 3-D reprojection step requires similar optimal interpolation parameters as found in our previous studies on Fourier-based iterative approaches, the optimal interpolation parameters for the main 3D-FRP reconstruction stage are quite different. Our experimental results confirm that for the optimal interpolation parameters a very good image accuracy can be achieved even without any extra spectral oversampling, which is a common practice to decrease errors

  16. Optical modeling, design optimization, and performance analysis of a gamma camera for detection of breast cancer

    NASA Astrophysics Data System (ADS)

    Sain, John David

    2001-07-01

    This dissertation presents the research performed to develop an optical model, improve some design parameters, and analyze the performance of the UA modular gamma camera. Initially we provide a brief background on nuclear medical imaging with scintillation cameras. The key hardware components of a camera are introduced, and some of the fundamental physics involved in the detection of gamma rays is explained. Then we describe a stand-alone modular camera imaging system that was developed to image human breasts in the clinic. The hardware and software components, calibration procedure, and general operation of the system are detailed. We explain the concepts of position estimation and scatter rejection and note how they have been applied to imaging with the UA modular gamma camera. Position estimation uses the output signals of the camera to determine where an incident gamma ray interacted within the camera, and scatter rejection uses the signals to decide whether or not an incident gamma ray underwent scattering prior to being detected by the camera. Then we present an analytical optical model of the UA modular gamma camera. Taking into account physical and optical properties of the camera components, the model performs radiometric calculations to estimate the mean response of the camera to a scintillation event anywhere within the scintillation crystal. The results of several studies using the optical model to test and improve some camera design parameters are reported. Finally, we demonstrate how straightforward signal detection theory can be used to evaluate the performance of a modular gamma camera for the task of detecting signals in noisy backgrounds. Guided by the preliminary design of a dedicated breast imaging system, estimates of how well the UA modular gamma camera can detect lesions within human breasts were generated.

  17. Optimization of transmission and emission scan duration in 3D whole-body PET

    SciTech Connect

    Beyer, T.; Kinahan, P.E.; Townsend, D.W.

    1996-12-31

    Whole-body PET imaging is being increasingly used to identify and localize malignant disease remote from the site of the primary tumor. Patients are typically scanned at multiple contiguous bed positions over an axial length of 75-100 cm. For oncology patients, the total scan duration should not exceed about an hour and therefore only 5-10 minutes of imaging can be performed at each bed position. To minimize the total scan duration, the transmission scan is often omitted and the emission scan reconstructed without attenuation correction. However, whole-body scans reconstructed without attenuation correction can lead to incorrect diagnosis, particularly for tumors located deep within the body. We have performed a series of torso phantom measurements to investigate the optimal partition of scan time between the emission and transmission scans for a fixed total scan duration. We find that a transmission fraction of about 0.4 is optimal for a 5 min and 10 min total acquisition time per bed position. The optimal partition depends on the way the attenuation correction factors are calculated and on the reconstruction algorithm.

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

    NASA Astrophysics Data System (ADS)

    Heredia-Munoz, Manuel Antonio

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

  19. Calibration of a dual-PTZ-camera system for stereo vision based on parallel particle swarm optimization method

    NASA Astrophysics Data System (ADS)

    Chang, Yau-Zen; Wang, Huai-Ming; Lee, Shih-Tseng; Wu, Chieh-Tsai; Hsu, Ming-Hsi

    2014-02-01

    This work investigates the calibration of a stereo vision system based on two PTZ (Pan-Tilt-Zoom) cameras. As the accuracy of the system depends not only on intrinsic parameters, but also on the geometric relationships between rotation axes of the cameras, the major concern is the development of an effective and systematic way to obtain these relationships. We derived a complete geometric model of the dual-PTZ-camera system and proposed a calibration procedure for the intrinsic and external parameters of the model. The calibration method is based on Zhang's approach using an augmented checkerboard composed of eight small checkerboards, and is formulated as an optimization problem to be solved by an improved particle swarm optimization (PSO) method. Two Sony EVI-D70 PTZ cameras were used for the experiments. The root-mean-square errors (RMSE) of corner distances in the horizontal and vertical direction are 0.192 mm and 0.115 mm, respectively. The RMSE of overlapped points between the small checkerboards is 1.3958 mm.

  20. Optimization of LSO/LuYAP phoswich detector for small animal PET

    NASA Astrophysics Data System (ADS)

    Jung, Jin Ho; Choi, Yong; Chung, Yong Hyun; Devroede, Olivier; Krieguer, Magalie; Bruyndonckx, Peter; Tavernier, Stefaan

    2007-02-01

    LSO/LuYAP phoswich detectors for small animal PET were developed to measure the depth of interaction (DOI), and to improve the spatial resolution at the edge of the field of view (FOV). The aim of this study was to optimize the optical coupling conditions between the crystal and photomultiplier tube (PMT) to maximize the light-collection efficiency, and to develop a method for rejecting scatter events by applying an equal energy window in each crystal layer. The light yields of the phoswich detector were estimated by changing the refractive index of the optical coupling material using a DETECT simulation. The accuracy of the DOI measurement on the phoswich detector, using an optical coupling material with the optimal light yield, were evaluated experimentally and compared with the air condition. The energy window for the photopeak events cannot be applied properly because the light outputs of LSO and LuYAP are different. The LSO/LuYAP photopeaks need to be superposed in order to effectively discriminate the scattered events by applying an equal energy window. The photopeaks of the LSO and LuYAP can be superposed by inserting a reflecting material between the crystals. The optimal coverage ratio of the inserting material was derived from a DETECT simulation, and its performance was investigated. In the simulation result, optimal refractive index of the optical coupling material was 1.7. The average DOI measurement errors of the LSO/LuYAP were 0.6%/3.4% and 4.9%/41.4% in the phoswich detector with and without an optical coupling material, respectively. The photopeaks of the LSO and LuYAP were superposed by covering 75% of the contact surface between the crystals with white Teflon. The DOI measurement errors of the LSO/LuYAP were 0.2%/2.4%. In this study, the optimal condition of the optical coupling material inserted between the crystal and PMT was derived to improve the accuracy of DOI measurement, and a photopeak superposition method of the LSO and LuYAP was

  1. Optimization of oncological {sup 18}F-FDG PET/CT imaging based on a multiparameter analysis

    SciTech Connect

    Menezes, Vinicius O.; D’Errico, Francesco; Namías, Mauro; Larocca, Ticiana F.; Soares, Milena B. P.

    2016-02-15

    Purpose: This paper describes a method to achieve consistent clinical image quality in {sup 18}F-FDG scans accounting for patient habitus, dose regimen, image acquisition, and processing techniques. Methods: Oncological PET/CT scan data for 58 subjects were evaluated retrospectively to derive analytical curves that predict image quality. Patient noise equivalent count rate and coefficient of variation (CV) were used as metrics in their analysis. Optimized acquisition protocols were identified and prospectively applied to 179 subjects. Results: The adoption of different schemes for three body mass ranges (<60 kg, 60–90 kg, >90 kg) allows improved image quality with both point spread function and ordered-subsets expectation maximization-3D reconstruction methods. The application of this methodology showed that CV improved significantly (p < 0.0001) in clinical practice. Conclusions: Consistent oncological PET/CT image quality on a high-performance scanner was achieved from an analysis of the relations existing between dose regimen, patient habitus, acquisition, and processing techniques. The proposed methodology may be used by PET/CT centers to develop protocols to standardize PET/CT imaging procedures and achieve better patient management and cost-effective operations.

  2. Convex Optimization of Coincidence Time Resolution for a High-Resolution PET System

    PubMed Central

    Reynolds, Paul D.; Olcott, Peter D.; Pratx, Guillem; Lau, Frances W. Y.

    2013-01-01

    We are developing a dual panel breast-dedicated positron emission tomography (PET) system using LSO scintillators coupled to position sensitive avalanche photodiodes (PSAPD). The charge output is amplified and read using NOVA RENA-3 ASICs. This paper shows that the coincidence timing resolution of the RENA-3 ASIC can be improved using certain list-mode calibrations. We treat the calibration problem as a convex optimization problem and use the RENA-3’s analog-based timing system to correct the measured data for time dispersion effects from correlated noise, PSAPD signal delays and varying signal amplitudes. The direct solution to the optimization problem involves a matrix inversion that grows order (n3) with the number of parameters. An iterative method using single-coordinate descent to approximate the inversion grows order (n). The inversion does not need to run to convergence, since any gains at high iteration number will be low compared to noise amplification. The system calibration method is demonstrated with measured pulser data as well as with two LSO-PSAPD detectors in electronic coincidence. After applying the algorithm, the 511 keV photopeak paired coincidence time resolution from the LSO-PSAPD detectors under study improved by 57%, from the raw value of 16.3 ± 0.07 ns full-width at half-maximum (FWHM) to 6.92 ± 0.02 ns FWHM (11.52 ± 0.05 ns to 4.89 ± 0.02 ns for unpaired photons). PMID:20876008

  3. Application of Two Phase (Liquid/Gas) Xenon Gamma-Camera for the Detection of Special Nuclear Material and PET Medical Imaging

    SciTech Connect

    McKinsey, Daniel Nicholas

    2013-08-27

    The McKinsey group at Yale has been awarded a grant from DTRA for the building of a Liquid Xenon Gamma Ray Color Camera (LXe-GRCC), which combines state-of-the-art detection of LXe scintillation light and time projection chamber (TPC) charge readout. The DTRA application requires a movable detector and hence only a single phase (liquid) xenon detector can be considered in this case. We propose to extend the DTRA project to applications that allow a two phase (liquid/gas) xenon TPC. This entails additional (yet minimal) hardware and extension of the research effort funded by DTRA. The two phase detector will have better energy and angular resolution. Such detectors will be useful for PET medical imaging and detection of special nuclear material in stationary applications (e.g. port of entry). The expertise of the UConn group in gas phase TPCs will enhance the capabilities of the Yale group and the synergy between the two groups will be very beneficial for this research project as well as the education and research projects of the two universities. The LXe technology to be used in this project has matured rapidly over the past few years, developed for use in detectors for nuclear physics and astrophysics. This technology may now be applied in a straightforward way to the imaging of gamma rays. According to detailed Monte Carlo simulations recently performed at Yale University, energy resolution of 1% and angular resolution of 3 degrees may be obtained for 1.0 MeV gamma rays, using existing technology. With further research and development, energy resolution of 0.5% and angular resolution of 1.3 degrees will be possible at 1.0 MeV. Because liquid xenon is a high density, high Z material, it is highly efficient for scattering and capturing gamma rays. In addition, this technology scales elegantly to large detector areas, with several square meter apertures possible. The Yale research group is highly experienced in the development and use of noble liquid detectors for

  4. Design and optimization for main support structure of a large-area off-axis three-mirror space camera.

    PubMed

    Wei, Lei; Zhang, Lei; Gong, Xiaoxue; Ma, Dong-Mei

    2017-02-01

    To ensure excellent dynamic and static performance of large-area, off-axis three-mirror anastigmat (TMA)-space cameras, and to realize a lighter weight for the entire system, a truss support structure design is applied in this study. In contrast to traditional methods, this paper adopts topology optimization based on the solid isotropic materials with penalization method on the truss structure design. Through reasonable object function and constraint choice, optimal topology results that have concerned the effect of gravity in the X, Y, and Z axis are achieved. Subsequently, the initial truss structure is designed based on the results and manufacturing technology. Moreover, to reduce the random vibration response of the secondary mirror and fold mirror without mechanical performance decline of the whole truss, a weighted optimization of truss size is proposed and the final truss structure is achieved. Finite element analysis and experiments have confirmed the reliability of the design and optimization method. The designed truss-structure camera maintains excellent static performance with the relative optical axis angle between the primary mirror and corresponding mirrors (secondary mirror and fold mirror) being less than 5.3 in. Dynamic performances, such as random and sinusoidal vibration responses, also met the requirements that the acceleration RMS value for mount points of the fold mirror should be less than 20 g and the primary frequency reached 97.2 Hz.

  5. Optimal whole-body PET scanner configurations for different volumes of LSO scintillator: a simulation study

    NASA Astrophysics Data System (ADS)

    Poon, Jonathan K.; Dahlbom, Magnus L.; Moses, William W.; Balakrishnan, Karthik; Wang, Wenli; Cherry, Simon R.; Badawi, Ramsey D.

    2012-07-01

    The axial field of view (AFOV) of the current generation of clinical whole-body PET scanners range from 15-22 cm, which limits sensitivity and renders applications such as whole-body dynamic imaging or imaging of very low activities in whole-body cellular tracking studies, almost impossible. Generally, extending the AFOV significantly increases the sensitivity and count-rate performance. However, extending the AFOV while maintaining detector thickness has significant cost implications. In addition, random coincidences, detector dead time, and object attenuation may reduce scanner performance as the AFOV increases. In this paper, we use Monte Carlo simulations to find the optimal scanner geometry (i.e. AFOV, detector thickness and acceptance angle) based on count-rate performance for a range of scintillator volumes ranging from 10 to 93 l with detector thickness varying from 5 to 20 mm. We compare the results to the performance of a scanner based on the current Siemens Biograph mCT geometry and electronics. Our simulation models were developed based on individual components of the Siemens Biograph mCT and were validated against experimental data using the NEMA NU-2 2007 count-rate protocol. In the study, noise-equivalent count rate (NECR) was computed as a function of maximum ring difference (i.e. acceptance angle) and activity concentration using a 27 cm diameter, 200 cm uniformly filled cylindrical phantom for each scanner configuration. To reduce the effect of random coincidences, we implemented a variable coincidence time window based on the length of the lines of response, which increased NECR performance up to 10% compared to using a static coincidence time window for scanners with a large maximum ring difference values. For a given scintillator volume, the optimal configuration results in modest count-rate performance gains of up to 16% compared to the shortest AFOV scanner with the thickest detectors. However, the longest AFOV of approximately 2 m with 20 mm

  6. Optimal whole-body PET scanner configurations for different volumes of LSO scintillator: a simulation study.

    PubMed

    Poon, Jonathan K; Dahlbom, Magnus L; Moses, William W; Balakrishnan, Karthik; Wang, Wenli; Cherry, Simon R; Badawi, Ramsey D

    2012-07-07

    The axial field of view (AFOV) of the current generation of clinical whole-body PET scanners range from 15-22 cm, which limits sensitivity and renders applications such as whole-body dynamic imaging or imaging of very low activities in whole-body cellular tracking studies, almost impossible. Generally, extending the AFOV significantly increases the sensitivity and count-rate performance. However, extending the AFOV while maintaining detector thickness has significant cost implications. In addition, random coincidences, detector dead time, and object attenuation may reduce scanner performance as the AFOV increases. In this paper, we use Monte Carlo simulations to find the optimal scanner geometry (i.e. AFOV, detector thickness and acceptance angle) based on count-rate performance for a range of scintillator volumes ranging from 10 to 93 l with detector thickness varying from 5 to 20 mm. We compare the results to the performance of a scanner based on the current Siemens Biograph mCT geometry and electronics. Our simulation models were developed based on individual components of the Siemens Biograph mCT and were validated against experimental data using the NEMA NU-2 2007 count-rate protocol. In the study, noise-equivalent count rate (NECR) was computed as a function of maximum ring difference (i.e. acceptance angle) and activity concentration using a 27 cm diameter, 200 cm uniformly filled cylindrical phantom for each scanner configuration. To reduce the effect of random coincidences, we implemented a variable coincidence time window based on the length of the lines of response, which increased NECR performance up to 10% compared to using a static coincidence time window for scanners with a large maximum ring difference values. For a given scintillator volume, the optimal configuration results in modest count-rate performance gains of up to 16% compared to the shortest AFOV scanner with the thickest detectors. However, the longest AFOV of approximately 2 m with

  7. 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.

  8. Optimization of a Model Corrected Blood Input Function from Dynamic FDG-PET Images of Small Animal Heart In Vivo

    PubMed Central

    Zhong, Min; Kundu, Bijoy K.

    2013-01-01

    Quantitative evaluation of dynamic Positron Emission Tomography (PET) of mouse heart in vivo is challenging due to the small size of the heart and limited intrinsic spatial resolution of the PET scanner. Here, we optimized a compartment model which can simultaneously correct for spill over and partial volume effects for both blood pool and the myocardium, compute kinetic rate parameters and generate model corrected blood input function (MCBIF) from ordered subset expectation maximization – maximum a posteriori (OSEM-MAP) cardiac and respiratory gated 18F-FDG PET images of mouse heart with attenuation correction in vivo, without any invasive blood sampling. Arterial blood samples were collected from a single mouse to indicate the feasibility of the proposed method. In order to establish statistical significance, venous blood samples from n=6 mice were obtained at 2 late time points, when SP contamination from the tissue to the blood is maximum. We observed that correct bounds and initial guesses for the PV and SP coefficients accurately model the wash-in and wash-out dynamics of the tracer from mouse blood. The residual plot indicated an average difference of about 1.7% between the blood samples and MCBIF. The downstream rate of myocardial FDG influx constant, Ki (0.15±0.03 min−1), compared well with Ki obtained from arterial blood samples (P=0.716). In conclusion, the proposed methodology is not only quantitative but also reproducible. PMID:24741130

  9. A risk-based coverage model for video surveillance camera control optimization

    NASA Astrophysics Data System (ADS)

    Zhang, Hongzhou; Du, Zhiguo; Zhao, Xingtao; Li, Peiyue; Li, Dehua

    2015-12-01

    Visual surveillance system for law enforcement or police case investigation is different from traditional application, for it is designed to monitor pedestrians, vehicles or potential accidents. Visual surveillance risk is defined as uncertainty of visual information of targets and events monitored in present work and risk entropy is introduced to modeling the requirement of police surveillance task on quality and quantity of vide information. the prosed coverage model is applied to calculate the preset FoV position of PTZ camera.

  10. Optimization of Early Response Monitoring and Prediction of Cancer Antiangiogenesis Therapy via Noninvasive PET Molecular Imaging Strategies of Multifactorial Bioparameters.

    PubMed

    Bao, Xiao; Wang, Ming-Wei; Luo, Jian-Min; Wang, Si-Yang; Zhang, Yong-Ping; Zhang, Ying-Jian

    2016-01-01

    Objective: Antiangiogenesis therapy (AAT) has provided substantial benefits regarding improved outcomes and survival for suitable patients in clinical settings. Therefore, the early definition of therapeutic effects is urgently needed to guide cancer AAT. We aimed to optimize the early response monitoring and prediction of AAT efficacy, as indicated by the multi-targeted anti-angiogenic drug sunitinib in U87MG tumors, using noninvasive positron emission computed tomography (PET) molecular imaging strategies of multifactorial bioparameters. Methods: U87MG tumor mice were treated via intragastric injections of sunitinib (80 mg/kg) or vehicle for 7 consecutive days. Longitudinal MicroPET/CT scans with (18)F-FDG, (18)F-FMISO, (18)F-ML-10 and (18)F-Alfatide II were acquired to quantitatively measure metabolism, hypoxia, apoptosis and angiogenesis on days 0, 1, 3, 7 and 13 following therapy initiation. Tumor tissues from a dedicated group of mice were collected for immunohistochemical (IHC) analysis of key biomarkers (Glut-1, CA-IX, TUNEL, ανβ3 and CD31) at the time points of PET imaging. The tumor sizes and mouse weights were measured throughout the study. The tumor uptake (ID%/gmax), the ratios of the tumor/muscle (T/M) for each probe, and the tumor growth ratios (TGR) were calculated and used for statistical analyses of the differences and correlations. Results: Sunitinib successfully inhibited U87MG tumor growth with significant differences in the tumor size from day 9 after sunitinib treatment compared with the control group (P < 0.01). The uptakes of (18)F-FMISO (reduced hypoxia), (18)F-ML-10 (increased apoptosis) and (18)F-Alfatide II (decreased angiogenesis) in the tumor lesions significantly changed during the early stage (days 1 to 3) of sunitinib treatment; however, the uptake of (18)F-FDG (increased glucose metabolism) was significantly different during the late stage. The PET imaging data of each probe were all confirmed via ex vivo IHC of the relevant

  11. PET optimization for improved assessment and accurate quantification of {sup 90}Y-microsphere biodistribution after radioembolization

    SciTech Connect

    Martí-Climent, Josep M. Prieto, Elena; Elosúa, César; Rodríguez-Fraile, Macarena; Domínguez-Prado, Inés; Vigil, Carmen; García-Velloso, María J.; Arbizu, Javier; Peñuelas, Iván; Richter, José A.

    2014-09-15

    Purpose: {sup 90}Y-microspheres are widely used for the radioembolization of metastatic liver cancer or hepatocellular carcinoma and there is a growing interest for imaging {sup 90}Y-microspheres with PET. The aim of this study is to evaluate the performance of a current generation PET/CT scanner for {sup 90}Y imaging and to optimize the PET protocol to improve the assessment and the quantification of {sup 90}Y-microsphere biodistribution after radioembolization. Methods: Data were acquired on a Biograph mCT-TrueV scanner with time of flight (TOF) and point spread function (PSF) modeling. Spatial resolution was measured with a{sup 90}Y point source. Sensitivity was evaluated using the NEMA 70 cm line source filled with {sup 90}Y. To evaluate the count rate performance, {sup 90}Y vials with activity ranging from 3.64 to 0.035 GBq were measured in the center of the field of view (CFOV). The energy spectrum was evaluated. Image quality with different reconstructions was studied using the Jaszczak phantom containing six hollow spheres (diameters: 31.3, 28.1, 21.8, 16.1, 13.3, and 10.5 mm), filled with a 207 kBq/ml {sup 90}Y concentration and a 5:1 sphere-to-background ratio. Acquisition time was adjusted to simulate the quality of a realistic clinical PET acquisition of a patient treated with SIR-Spheres{sup ®}. The developed methodology was applied to ten patients after SIR-Spheres{sup ®} treatment acquiring a 10 min per bed PET. Results: The energy spectrum showed the{sup 90}Y bremsstrahlung radiation. The {sup 90}Y transverse resolution, with filtered backprojection reconstruction, was 4.5 mm in the CFOV and degraded to 5.0 mm at 10 cm off-axis. {sup 90}Y absolute sensitivity was 0.40 kcps/MBq in the center of the field of view. Tendency of true and random rates as a function of the {sup 90}Y activity could be accurately described using linear and quadratic models, respectively. Phantom studies demonstrated that, due to low count statistics in {sup 90}Y PET

  12. Optimization of Early Response Monitoring and Prediction of Cancer Antiangiogenesis Therapy via Noninvasive PET Molecular Imaging Strategies of Multifactorial Bioparameters

    PubMed Central

    Bao, Xiao; Wang, Ming-Wei; Luo, Jian-Min; Wang, Si-Yang; Zhang, Yong-Ping; Zhang, Ying-Jian

    2016-01-01

    Objective: Antiangiogenesis therapy (AAT) has provided substantial benefits regarding improved outcomes and survival for suitable patients in clinical settings. Therefore, the early definition of therapeutic effects is urgently needed to guide cancer AAT. We aimed to optimize the early response monitoring and prediction of AAT efficacy, as indicated by the multi-targeted anti-angiogenic drug sunitinib in U87MG tumors, using noninvasive positron emission computed tomography (PET) molecular imaging strategies of multifactorial bioparameters. Methods: U87MG tumor mice were treated via intragastric injections of sunitinib (80 mg/kg) or vehicle for 7 consecutive days. Longitudinal MicroPET/CT scans with 18F-FDG, 18F-FMISO, 18F-ML-10 and 18F-Alfatide II were acquired to quantitatively measure metabolism, hypoxia, apoptosis and angiogenesis on days 0, 1, 3, 7 and 13 following therapy initiation. Tumor tissues from a dedicated group of mice were collected for immunohistochemical (IHC) analysis of key biomarkers (Glut-1, CA-IX, TUNEL, ανβ3 and CD31) at the time points of PET imaging. The tumor sizes and mouse weights were measured throughout the study. The tumor uptake (ID%/gmax), the ratios of the tumor/muscle (T/M) for each probe, and the tumor growth ratios (TGR) were calculated and used for statistical analyses of the differences and correlations. Results: Sunitinib successfully inhibited U87MG tumor growth with significant differences in the tumor size from day 9 after sunitinib treatment compared with the control group (P < 0.01). The uptakes of 18F-FMISO (reduced hypoxia), 18F-ML-10 (increased apoptosis) and 18F-Alfatide II (decreased angiogenesis) in the tumor lesions significantly changed during the early stage (days 1 to 3) of sunitinib treatment; however, the uptake of 18F-FDG (increased glucose metabolism) was significantly different during the late stage. The PET imaging data of each probe were all confirmed via ex vivo IHC of the relevant biomarkers

  13. GISMO, a 2 mm Bolometer Camera Optimized for the Study of High Redshift Galaxies

    NASA Technical Reports Server (NTRS)

    Staguhn, J.

    2007-01-01

    The 2mm spectral range provides a unique terrestrial window enabling ground based observations of the earliest active dusty galaxies in the universe and thereby allowing a better constraint on the star formation rate in these objects. We present a progress report for our bolometer camera GISMO (the Goddard-IRAM Superconducting 2-Millimeter Observer), which will obtain large and sensitive sky maps at this wavelength. The instrument will be used at the IRAM 30 m telescope and we expect to install it at the telescope in 2007. The camera uses an 8 x 16 planar array of multiplexed TES bolometers, which incorporates our recently designed Backshort Under Grid (BUG) architecture. GISMO will be very efficient at detecting sources serendipitously in large sky surveys. With the background limited performance of the detectors, the camera provides significantly greater imaging sensitivity and mapping speed at this wavelength than has previously been possible. The major scientific driver for the instrument is to provide the IRAM 30 m telescope with the capability to rapidly observe galactic and extragalactic dust emission, in particular from high-zeta ULI RGs and quasar s, even in the summer season. The instrument will fill in the SEDs of high redshift galaxies at the Rayleigh-Jeans part of the dust emission spectrum, even at the highest redshifts. Our source count models predict that GISMO will serendipitously detect one galaxy every four hours on the blank sky, and that one quarter of these galaxies will be at a redshift of zeta 6.5.

  14. Optimal UAV Path Planning for Tracking a Moving Ground Vehicle with a Gimbaled Camera

    DTIC Science & Technology

    2014-03-27

    optimization. The next step is to find the optimal path for a given ground profile by using nonlinear programming ( NLP ) to solve the optimal control problem...that the choice of the NLP solver can have an effect on the solution. For more information about both the IPM and ASM solvers see reference [15]. The

  15. Optimization of super-resolution processing using incomplete image sets in PET imaging.

    PubMed

    Chang, Guoping; Pan, Tinsu; Clark, John W; Mawlawi, Osama R

    2008-12-01

    Super-resolution (SR) techniques are used in PET imaging to generate a high-resolution image by combining multiple low-resolution images that have been acquired from different points of view (POVs). The number of low-resolution images used defines the processing time and memory storage necessary to generate the SR image. In this paper, the authors propose two optimized SR implementations (ISR-1 and ISR-2) that require only a subset of the low-resolution images (two sides and diagonal of the image matrix, respectively), thereby reducing the overall processing time and memory storage. In an N x N matrix of low-resolution images, ISR-1 would be generated using images from the two sides of the N x N matrix, while ISR-2 would be generated from images across the diagonal of the image matrix. The objective of this paper is to investigate whether the two proposed SR methods can achieve similar performance in contrast and signal-to-noise ratio (SNR) as the SR image generated from a complete set of low-resolution images (CSR) using simulation and experimental studies. A simulation, a point source, and a NEMA/IEC phantom study were conducted for this investigation. In each study, 4 (2 x 2) or 16 (4 x 4) low-resolution images were reconstructed from the same acquired data set while shifting the reconstruction grid to generate images from different POVs. SR processing was then applied in each study to combine all as well as two different subsets of the low-resolution images to generate the CSR, ISR-1, and ISR-2 images, respectively. For reference purpose, a native reconstruction (NR) image using the same matrix size as the three SR images was also generated. The resultant images (CSR, ISR-1, ISR-2, and NR) were then analyzed using visual inspection, line profiles, SNR plots, and background noise spectra. The simulation study showed that the contrast and the SNR difference between the two ISR images and the CSR image were on average 0.4% and 0.3%, respectively. Line profiles of

  16. Optimizing process time of laser drilling processes in solar cell manufacturing by coaxial camera control

    NASA Astrophysics Data System (ADS)

    Jetter, Volker; Gutscher, Simon; Blug, Andreas; Knorz, Annerose; Ahrbeck, Christopher; Nekarda, Jan; Carl, Daniel

    2014-03-01

    In emitter wrap through (EWT) solar cells, laser drilling is used to increase the light sensitive area by removing emitter contacts from the front side of the cell. For a cell area of 156 x 156 mm2, about 24000 via-holes with a diameter of 60 μm have to be drilled into silicon wafers with a thickness of 200 μm. The processing time of 10 to 20 s is determined by the number of laser pulses required for safely opening every hole on the bottom side. Therefore, the largest wafer thickness occurring in a production line defines the processing time. However, wafer thickness varies by roughly +/-20 %. To reduce the processing time, a coaxial camera control system was integrated into the laser scanner. It observes the bottom breakthrough from the front side of the wafer by measuring the process emissions of every single laser pulse. To achieve the frame rates and latency times required by the repetition rate of the laser (10 kHz), a camera based on cellular neural networks (CNN) was used where the images are processed directly on the camera chip by 176 x 144 sensor-processor-elements. One image per laser pulse is processed within 36 μs corresponding to a maximum pulse rate of 25 kHz. The laser is stopped when all of the holes are open on the bottom side. The result is a quality control system in which the processing time of a production line is defined by average instead of maximum wafer thickness.

  17. Optimization of the Energy Window for PETbox4, a Preclinical PET Tomograph With a Small Inner Diameter

    PubMed Central

    Gu, Z.; Bao, Q.; Taschereau, R.; Wang, H.; Bai, B.; Chatziioannou, A. F.

    2015-01-01

    Small animal positron emission tomography (PET) systems are often designed by employing close geometry configurations. Due to the different characteristics caused by geometrical factors, these tomographs require data acquisition protocols that differ from those optimized for conventional large diameter ring systems. In this work we optimized the energy window for data acquisitions with PETbox4, a 50 mm detector separation (box-like geometry) pre-clinical PET scanner, using the Geant4 Application for Tomographic Emission (GATE). The fractions of different types of events were estimated using a voxelized phantom including a mouse as well as its supporting chamber, mimicking a realistic mouse imaging environment. Separate code was developed to extract additional information about the gamma interactions for more accurate event type classification. Three types of detector backscatter events were identified in addition to the trues, phantom scatters and randoms. The energy window was optimized based on the noise equivalent count rate (NECR) and scatter fraction (SF) with lower-level discriminators (LLD) corresponding to energies from 150 keV to 450 keV. The results were validated based on the calculated image uniformity, spillover ratio (SOR) and recovery coefficient (RC) from physical measurements using the National Electrical Manufacturers Association (NEMA) NU-4 image quality phantom. These results indicate that when PETbox4 is operated with a more narrow energy window (350-650 keV), detector backscatter rejection is unnecessary. For the NEMA NU-4 image quality phantom, the SOR for the water chamber decreases by about 45% from 15.1% to 8.3%, and the SOR for the air chamber decreases by 31% from 12.0% to 8.3% at the LLDs of 150 and 350 keV, without obvious change in uniformity, further supporting the simulation based optimization. The optimization described in this work is not limited to PETbox4, but also applicable or helpful to other small inner diameter geometry

  18. Optimization of spectral sensitivities of mosaic five-band camera for estimating chromophore densities from skin images including shading and surface reflections

    NASA Astrophysics Data System (ADS)

    Hirose, Misa; Akaho, Rina; Maita, Chikashi; Sugawara, Mai; Tsumura, Norimichi

    2016-06-01

    In this paper, the spectral sensitivities of a mosaic five-band camera were optimized using a numerical skin phantom to perform the separation of chromophore densities, shading and surface reflection. To simulate the numerical skin phantom, the spectral reflectance of skin was first calculated by Monte Carlo simulation of photon migration for different concentrations of melanin, blood and oxygen saturation levels. The melanin and hemoglobin concentration distributions used in the numerical skin phantom were obtained from actual skin images by independent component analysis. The calculated components were assigned as concentration distributions. The spectral sensitivities of the camera were then optimized using a nonlinear technique to estimate the spectral reflectance for skin separation. In this optimization, the spectral sensitivities were assumed to be normally distributed, and the sensor arrangement was identical to that of a conventional mosaic five-band camera. Our findings demonstrated that spectral estimation could be significantly improved by optimizing the spectral sensitivities.

  19. Comparison of FDG PET and positron coincidence detection imaging using a dual-head gamma camera with 5/8-inch NaI(Tl) crystals in patients with suspected body malignancies.

    PubMed

    Boren, E L; Delbeke, D; Patton, J A; Sandler, M P

    1999-04-01

    The purpose of this study was to compare the diagnostic accuracy of fluorine-18 fluorodeoxyglucose (FDG) images obtained with (a) a dual-head coincidence gamma camera (DHC) equipped with 5/8-inch-thick NaI(Tl) crystals and parallel slit collimators and (b) a dedicated positron emission tomograph (PET) in a series of 28 patients with known or suspected malignancies. Twenty-eight patients with known or suspected malignancies underwent whole-body FDG PET imaging (Siemens, ECAT 933) after injection of approximately 10 mCi of 18F-FDG. FDG DHC images were then acquired for 30 min over the regions of interest using a dual-head gamma camera (VariCam, Elscint). The images were reconstructed in the normal mode, using photopeak/photopeak, photopeak/Compton, and Compton/photopeak coincidence events. FDG PET imaging found 45 lesions ranging in size from 1 cm to 7 cm in 28 patients. FDG DHC imaging detected 35/45 (78%) of these lesions. Among the ten lesions not seen with FDG DHC imaging, eight were less than 1.5 cm in size, and two were located centrally within the abdomen suffering from marked attenuation effects. The lesions were classified into three categories: thorax (n=24), liver (n=12), and extrahepatic abdominal (n=9). FDG DHC imaging identified 100% of lesions above 1.5 cm in the thorax group and 78% of those below 1.5 cm, for an overall total of 83%. FDG DHC imaging identified 100% of lesions above 1.5 cm, in the liver and 43% of lesions below 1.5 cm, for an overall total of 67%. FDG DHC imaging identified 78% of lesions above 1.5 cm in the extrahepatic abdominal group. There were no lesions below 1.5 cm in this group. FDG coincidence imaging using a dual-head gamma camera detected 90% of lesions greater than 1.5 cm. These data suggest that DHC imaging can be used clinically in well-defined diagnostic situations to differentiate benign from malignant lesions.

  20. Optimization design of periscope type 3X zoom lens design for a five megapixel cellphone camera

    NASA Astrophysics Data System (ADS)

    Sun, Wen-Shing; Tien, Chuen-Lin; Pan, Jui-Wen; Chao, Yu-Hao; Chu, Pu-Yi

    2016-11-01

    This paper presents a periscope type 3X zoom lenses design for a five megapixel cellphone camera. The configuration of optical system uses the right angle prism in front of the zoom lenses to change the optical path rotated by a 90° angle resulting in the zoom lenses length of 6 mm. The zoom lenses can be embedded in mobile phone with a thickness of 6 mm. The zoom lenses have three groups with six elements. The half field of view is varied from 30° to 10.89°, the effective focal length is adjusted from 3.142 mm to 9.426 mm, and the F-number is changed from 2.8 to 5.13.

  1. Designing of High-Volume PET/CT Facility with Optimal Reduction of Radiation Exposure to the Staff: Implementation and Optimization in a Tertiary Health Care Facility in India

    PubMed Central

    Jha, Ashish Kumar; Singh, Abhijith Mohan; Mithun, Sneha; Shah, Sneha; Agrawal, Archi; Purandare, Nilendu C.; Shetye, Bhakti; Rangarajan, Venkatesh

    2015-01-01

    Positron emission tomography (PET) has been in use for a few decades but with its fusion with computed tomography (CT) in 2001, the new PET/CT integrated system has become very popular and is now a key influential modality for patient management in oncology. However, along with its growing popularity, a growing concern of radiation safety among the radiation professionals has become evident. We have judiciously developed a PET/CT facility with optimal shielding, along with an efficient workflow to perform high volume procedures and minimize the radiation exposure to the staff and the general public by reducing unnecessary patient proximity to the staff and general public. PMID:26420990

  2. SU-C-9A-01: Parameter Optimization in Adaptive Region-Growing for Tumor Segmentation in PET

    SciTech Connect

    Tan, S; Xue, M; Chen, W; D'Souza, W; Lu, W; Li, H

    2014-06-01

    Purpose: To design a reliable method to determine the optimal parameter in the adaptive region-growing (ARG) algorithm for tumor segmentation in PET. Methods: The ARG uses an adaptive similarity criterion m - fσ ≤ I-PET ≤ m + fσ, so that a neighboring voxel is appended to the region based on its similarity to the current region. When increasing the relaxing factor f (f ≥ 0), the resulting volumes monotonically increased with a sharp increase when the region just grew into the background. The optimal f that separates the tumor from the background is defined as the first point with the local maximum curvature on an Error function fitted to the f-volume curve. The ARG was tested on a tumor segmentation Benchmark that includes ten lung cancer patients with 3D pathologic tumor volume as ground truth. For comparison, the widely used 42% and 50% SUVmax thresholding, Otsu optimal thresholding, Active Contours (AC), Geodesic Active Contours (GAC), and Graph Cuts (GC) methods were tested. The dice similarity index (DSI), volume error (VE), and maximum axis length error (MALE) were calculated to evaluate the segmentation accuracy. Results: The ARG provided the highest accuracy among all tested methods. Specifically, the ARG has an average DSI, VE, and MALE of 0.71, 0.29, and 0.16, respectively, better than the absolute 42% thresholding (DSI=0.67, VE= 0.57, and MALE=0.23), the relative 42% thresholding (DSI=0.62, VE= 0.41, and MALE=0.23), the absolute 50% thresholding (DSI=0.62, VE=0.48, and MALE=0.21), the relative 50% thresholding (DSI=0.48, VE=0.54, and MALE=0.26), OTSU (DSI=0.44, VE=0.63, and MALE=0.30), AC (DSI=0.46, VE= 0.85, and MALE=0.47), GAC (DSI=0.40, VE= 0.85, and MALE=0.46) and GC (DSI=0.66, VE= 0.54, and MALE=0.21) methods. Conclusions: The results suggest that the proposed method reliably identified the optimal relaxing factor in ARG for tumor segmentation in PET. This work was supported in part by National Cancer Institute Grant R01 CA172638; The

  3. The design of an animal PET: flexible geometry for achieving optimal spatial resolution or high sensitivity.

    PubMed

    Weber, S; Terstegge, A; Herzog, H; Reinartz, R; Reinhart, P; Rongen, F; Müller-Gärtner, H W; Halling, H

    1997-10-01

    We present the design of a positron emission tomograph (PET) with flexible geometry dedicated to in vivo studies of small animals (TierPET). The scanner uses two pairs of detectors. Each detector consists of 400 small individual yttrium aluminum perovskite (YAP) scintillator crystals of dimensions 2 x 2 x 15 mm3, optically isolated and glued together, which are coupled to position-sensitive photomultiplier tubes (PSPMT's). The detector modules can be moved in a radial direction so that the detector-to-detector spacing can be varied. Special hardware has been built for coincidence detection, position detection, and real-time data acquisition, which is performed by a PC. The single-event data are transferred to workstations where the radioactivity distribution is reconstructed. The dimensions of the crystals and the detector layout are the result of extensive simulations which are described in this report, taking into account sensitivity, spatial resolution and additional parameters like parallax error or scatter effects. For the three-dimensional (3-D) reconstruction a genuine 3-D expectation-maximization (EM)-algorithm which can include the characteristics of the detector system has been implemented. The reconstruction software is flexible and matches the different detector configurations. The main advantage of the proposed animal PET scanner is its high flexibility, allowing the realization of various detector-system configurations. By changing the detector-to-detector spacing, the system is capable of either providing good spatial resolution or high sensitivity for dynamic studies of pharmacokinetics.

  4. Optimized list-mode acquisition and data processing procedures for ACS2 based PET systems.

    PubMed

    Langner, Jens; Bühler, Paul; Just, Uwe; Pötzsch, Christian; Will, Edmund; van den Hoff, Jörg

    2006-01-01

    PET systems using the acquisition control system version 2 (ACS2), e.g. the ECAT Exact HR PET scanner series, offer a rather restricted list-mode functionality. For instance, typical transfers of acquisition data consume a considerable amount of time. This represents a severe obstacle to the utilization of potential advantages of list-mode acquisition. In our study, we have developed hardware and software solutions which do not only allow for the integration of list-mode into routine procedures, but also improve the overall runtime stability of the system. We show that our methods are able to speed up the transfer of the acquired data to the image reconstruction and processing workstations by a factor of up to 140. We discuss how this improvement allows for the integration of list-mode-based post-processing methods such as an event-driven movement correction into the data processing environment, and how list-mode is able to improve the overall flexibility of PET investigations in general. Furthermore, we show that our methods are also attractive for conventional histogram-mode acquisition, due to the improved stability of the ACS2 system.

  5. Optimization of Acquisition time of 68Ga-PSMA-Ligand PET/MRI in Patients with Local and Metastatic Prostate Cancer

    PubMed Central

    Lütje, Susanne; Blex, Sebastian; Gomez, Benedikt; Schaarschmidt, Benedikt M.; Umutlu, Lale; Forsting, Michael; Jentzen, Walter; Bockisch, Andreas; Poeppel, Thorsten D.; Wetter, Axel

    2016-01-01

    Objective The aim of this optimization study was to minimize the acquisition time of 68Ga-HBED-CC-PSMA positron emission tomography/magnetic resonance imaging (PET/MRI) in patients with local and metastatic prostate cancer (PCa) to obtain a sufficient image quality and quantification accuracy without any appreciable loss. Methods Twenty patients with PCa were administered intravenously with the 68Ga-HBED-CC-PSMA ligand (mean activity 99 MBq/patient, range 76–148 MBq) and subsequently underwent PET/MRI at, on average, 168 min (range 77–320 min) after injection. PET and MR imaging data were acquired simultaneously. PET acquisition was performed in list mode and PET images were reconstructed at different time intervals (1, 2, 4, 6, 8, and 10 min). Data were analyzed regarding radiotracer uptake in tumors and muscle tissue and PET image quality. Tumor uptake was quantified in terms of the maximum and mean standardized uptake value (SUVmax, SUVmean) within a spherical volume of interest (VOI). Reference VOIs were drawn in the gluteus maximus muscle on the right side. PET image quality was evaluated by experienced nuclear physicians/radiologists using a five-point ordinal scale from 5–1 (excellent—insufficient). Results Lesion detectability linearly increased with increasing acquisition times, reaching its maximum at PET acquisition times of 4 min. At this image acquisition time, tumor lesions in 19/20 (95%) patients were detected. PET image quality showed a positive correlation with increasing acquisition time, reaching a plateau at 4–6 min image acquisition. Both SUVmax and SUVmean correlated inversely with acquisition time and reached a plateau at acquisition times after 4 min. Conclusion In the applied image acquisition settings, the optimal acquisition time of 68Ga-PSMA-ligand PET/MRI in patients with local and metastatic PCa was identified to be 4 min per bed position. At this acquisition time, PET image quality and lesion detectability reach a maximum

  6. Validation of an optimized SPM procedure for FDG-PET in dementia diagnosis in a clinical setting

    PubMed Central

    Perani, Daniela; Della Rosa, Pasquale Anthony; Cerami, Chiara; Gallivanone, Francesca; Fallanca, Federico; Vanoli, Emilia Giovanna; Panzacchi, Andrea; Nobili, Flavio; Pappatà, Sabina; Marcone, Alessandra; Garibotto, Valentina; Castiglioni, Isabella; Magnani, Giuseppe; Cappa, Stefano F.; Gianolli, Luigi

    2014-01-01

    Diagnostic accuracy in FDG-PET imaging highly depends on the operating procedures. In this clinical study on dementia, we compared the diagnostic accuracy at a single-subject level of a) Clinical Scenarios, b) Standard FDG Images and c) Statistical Parametrical (SPM) Maps generated via a new optimized SPM procedure. We evaluated the added value of FDG-PET, either Standard FDG Images or SPM Maps, to Clinical Scenarios. In 88 patients with neurodegenerative diseases (Alzheimer's Disease—AD, Frontotemporal Lobar Degeneration—FTLD, Dementia with Lewy bodies—DLB and Mild Cognitive Impairment—MCI), 9 neuroimaging experts made a forced diagnostic decision on the basis of the evaluation of the three types of information. There was also the possibility of a decision of normality on the FDG-PET images. The clinical diagnosis confirmed at a long-term follow-up was used as the gold standard. SPM Maps showed higher sensitivity and specificity (96% and 84%), and better diagnostic positive (6.8) and negative (0.05) likelihood ratios compared to Clinical Scenarios and Standard FDG Images. SPM Maps increased diagnostic accuracy for differential diagnosis (AD vs. FTD; beta 1.414, p = 0.019). The AUC of the ROC curve was 0.67 for SPM Maps, 0.57 for Clinical Scenarios and 0.50 for Standard FDG Images. In the MCI group, SPM Maps showed the highest predictive prognostic value (mean LOC = 2.46), by identifying either normal brain metabolism (exclusionary role) or hypometabolic patterns typical of different neurodegenerative conditions. PMID:25389519

  7. Analogs of JHU75528, a PET ligand for imaging of cerebral cannabinoid receptors (CB1): development of ligands with optimized lipophilicity and binding affinity

    PubMed Central

    Fan, Hong; Kotsikorou, Evangelia; Hoffman, Alexander F.; Ravert, Hayden T.; Holt, Daniel; Hurst, Dow P.; Lupica, Carl R.; Reggio, Patricia H.; Dannals, Robert F.; Horti, Andrew G.

    2009-01-01

    Cyano analogs of Rimonabant with high binding affinity for the cerebral cannabinoid receptor (CB1) and with optimized lipophilicity have been synthesized as potential positron emission tomography (PET) ligands. The best ligands of the series are optimal targets for the future radiolabeling with PET isotopes and in vivo evaluation as radioligands with enhanced properties for PET imaging of CB1 receptors in human subjects. Extracellular electrophysiological recordings in rodent brain slices demonstrated that JHU75528, 4, the lead compound of the new series, has functional CB antagonist properties that are consistent with its structural relationship to Rimonabant. Molecular modeling analysis revealed an important role of the binding of the cyano-group with the CB1 binding pocket. PMID:18511157

  8. Optimized design and research for cylindrical electrically controlled box of space camera

    NASA Astrophysics Data System (ADS)

    Wang, Hai-ping; Li, Yan-chun; Dong, Ji-hong; Guo, Quan-feng; Wang, Kejun; Wang, Yi-jian

    2014-09-01

    The object of study is the electric control box of a certain type of space remote sensor. In view of the existing shortcomings of the original electric control box, the electric control box is designed reasonably. In the result, the design of electronic control box supported by the cylindrical multi-point is proposed, which can solve the series of problem of the original program, such as the large volume, heavy weight, large signal interference. The camera control box is made of magnesium alloy which has light weight and high strength; by the structure design of stacked, the electronics system is classified integration; through the local shielding program, the problem of anti radiation and interference of electronics system is solved; by using the multi supporting structure scheme , the structural rigidity of the electric control box is improved, the modal by 57Hz increased to more than 120Hz, which meet the 100Hz technology of the design specifications; the box body is adopted by nickel for protection, which eliminating the possibility of air and humid environment on the corrosion of magnesium alloy. At present, the electric control box designed has been completed the

  9. Optimizing PiB-PET SUVR change-over-time measurement by a large-scale analysis of longitudinal reliability, plausibility, separability, and correlation with MMSE.

    PubMed

    Schwarz, Christopher G; Senjem, Matthew L; Gunter, Jeffrey L; Tosakulwong, Nirubol; Weigand, Stephen D; Kemp, Bradley J; Spychalla, Anthony J; Vemuri, Prashanthi; Petersen, Ronald C; Lowe, Val J; Jack, Clifford R

    2017-01-01

    Quantitative measurements of change in β-amyloid load from Positron Emission Tomography (PET) images play a critical role in clinical trials and longitudinal observational studies of Alzheimer's disease. These measurements are strongly affected by methodological differences between implementations, including choice of reference region and use of partial volume correction, but there is a lack of consensus for an optimal method. Previous works have examined some relevant variables under varying criteria, but interactions between them prevent choosing a method via combined meta-analysis. In this work, we present a thorough comparison of methods to measure change in β-amyloid over time using Pittsburgh Compound B (PiB) PET imaging.

  10. Single-shot depth camera lens design optimization based on a blur metric

    NASA Astrophysics Data System (ADS)

    Chen, Yung-Lin; Chang, Chuan-Chung; Angot, Ludovic; Chang, Chir-Weei; Tien, Chung-Hao

    2010-08-01

    Computational imaging technology can capture extra information at the sensor and can be used for various photographic applications, including imaging with extended depth of field or depth extraction for 3D applications. The depth estimation from a single captured photograph can be achieved through a phase coded lens and image processing. In this paper, we propose a new method to design a phase coded lens, using a blur metric (BM) as the design criterion. Matlab and Zemax are used for the co-optimization of optical coding and digital image process. The purpose of the design is to find a curve for which the BM changes continuously and seriously within a distance range. We verified our approach by simulation, and got a axial symmetric phase mask as the coded lens. By using a pseudo-random pattern which contains uniform black and white patches as the input image, and the on-axis point spread function (PSF) calculated from Zemax, we can evaluate the BM of the simulated image which is convoluted by the pseudo-random pattern and PSF. In order to ensure the BM curve evaluated from the on-axis PSF represents the result of the whole field of view, the PSF is also optimized to get high off-axis similarity.

  11. Clinical NECR in 18F-FDG PET scans: optimization of injected activity and variable acquisition time. Relationship with SNR

    NASA Astrophysics Data System (ADS)

    Carlier, T.; Ferrer, L.; Necib, H.; Bodet-Milin, C.; Rousseau, C.; Kraeber-Bodéré, F.

    2014-10-01

    The injected activity and the acquisition time per bed position for 18F-FDG PET scans are usually optimized by using metrics obtained from phantom experiments. However, optimal activity and time duration can significantly vary from a phantom set-up and from patient to patient. An approach using a patient-specific noise equivalent count rate (NECR) modelling has been previously proposed for optimizing clinical scanning protocols. We propose using the clinical NECR on a large population as a function of the body mass index (BMI) for deriving the optimal injected activity and acquisition duration per bed position. The relationship between the NEC and the signal-to-noise ratio (SNR) was assessed both in a phantom and in a clinical setting. 491 consecutive patients were retrospectively evaluated and divided into 4 BMI subgroups. Two criteria were used to optimize the injected activity and the time per bed position was adjusted using the NECR value while keeping the total acquisition time constant. Finally, the relationship between NEC and SNR was investigated using an anthropomorphic phantom and a population of 507 other patients. While the first dose regimen suggested a unique injected activity (665 MBq) regardless of the BMI, the second dose regimen proposed a variable activity and a total acquisition time according to the BMI. The NEC improvement was around 35% as compared with the local current injection rule. Variable time per bed position was derived according to BMI and anatomical region. NEC and number of true events were found to be highly correlated with SNR for the phantom set-up and partially confirmed in the patient study for the BMI subgroup under 28 kg m-2 suggesting that for the scanner, the nonlinear reconstruction algorithm used in this study and BMI < 28 kg m-2, NEC, or the number of true events linearly correlated with SNR2.

  12. Optimally Repeatable Kinetic Model Variant for Myocardial Blood Flow Measurements with 82Rb PET

    PubMed Central

    deKemp, Robert A.; Renaud, Jennifer M.; Adler, Andy; Beanlands, Rob S. B.; Klein, Ran

    2017-01-01

    Purpose. Myocardial blood flow (MBF) quantification with 82Rb positron emission tomography (PET) is gaining clinical adoption, but improvements in precision are desired. This study aims to identify analysis variants producing the most repeatable MBF measures. Methods. 12 volunteers underwent same-day test-retest rest and dipyridamole stress imaging with dynamic 82Rb PET, from which MBF was quantified using 1-tissue-compartment kinetic model variants: (1) blood-pool versus uptake region sampled input function (Blood/Uptake-ROI), (2) dual spillover correction (SOC-On/Off), (3) right blood correction (RBC-On/Off), (4) arterial blood transit delay (Delay-On/Off), and (5) distribution volume (DV) constraint (Global/Regional-DV). Repeatability of MBF, stress/rest myocardial flow reserve (MFR), and stress/rest MBF difference (ΔMBF) was assessed using nonparametric reproducibility coefficients (RPCnp = 1.45 × interquartile range). Results. MBF using SOC-On, RVBC-Off, Blood-ROI, Global-DV, and Delay-Off was most repeatable for combined rest and stress: RPCnp = 0.21 mL/min/g (15.8%). Corresponding MFR and ΔMBF RPCnp were 0.42 (20.2%) and 0.24 mL/min/g (23.5%). MBF repeatability improved with SOC-On at stress (p < 0.001) and tended to improve with RBC-Off at both rest and stress (p < 0.08). DV and ROI did not significantly influence repeatability. The Delay-On model was overdetermined and did not reliably converge. Conclusion. MBF and MFR test-retest repeatability were the best with dual spillover correction, left atrium blood input function, and global DV. PMID:28293274

  13. Optimizing Detection Rate and Characterization of Subtle Paroxysmal Neonatal Abnormal Facial Movements with Multi-Camera Video-Electroencephalogram Recordings.

    PubMed

    Pisani, Francesco; Pavlidis, Elena; Cattani, Luca; Ferrari, Gianluigi; Raheli, Riccardo; Spagnoli, Carlotta

    2016-06-01

    Objectives We retrospectively analyze the diagnostic accuracy for paroxysmal abnormal facial movements, comparing one camera versus multi-camera approach. Background Polygraphic video-electroencephalogram (vEEG) recording is the current gold standard for brain monitoring in high-risk newborns, especially when neonatal seizures are suspected. One camera synchronized with the EEG is commonly used. Methods Since mid-June 2012, we have started using multiple cameras, one of which point toward newborns' faces. We evaluated vEEGs recorded in newborns in the study period between mid-June 2012 and the end of September 2014 and compared, for each recording, the diagnostic accuracies obtained with one-camera and multi-camera approaches. Results We recorded 147 vEEGs from 87 newborns and found 73 episodes of paroxysmal facial abnormal movements in 18 vEEGs of 11 newborns with the multi-camera approach. By using the single-camera approach, only 28.8% of these events were identified (21/73). Ten positive vEEGs with multicamera with 52 paroxysmal facial abnormal movements (52/73, 71.2%) would have been considered as negative with the single-camera approach. Conclusions The use of one additional facial camera can significantly increase the diagnostic accuracy of vEEGs in the detection of paroxysmal abnormal facial movements in the newborns.

  14. Antarctic Surveying Telescope (AST3-3) NIR camera for the Kunlun Infrared Sky Survey (KISS): thermal optimization and system performance

    NASA Astrophysics Data System (ADS)

    Zheng, Jessica R.; Lawrence, Jon; Content, Robert; Churilov, Vladimir; Zhang, Kaiyuan; Yuan, Xiangyan; Lu, Haiping

    2016-08-01

    The Antarctic survey telescope (AST 3-3) near infrared(NIR) camera is designed to conduct the Kunlun Infrared Sky Survey which will provide a comprehensive exploration of the time varying Universe in the near infrared. It is going to be located at Dome A, on the Antarctic plateau, one of the most unique low background sites at the Kdark band (2.4μm). Carefully designed thermal emission from the telescope and the Kdark camera is very important to realize background limited operation. We setup a scattering and thermal emission model of the whole system to optimize the camera performance. An exposure time calculator was also built to predict system performance.

  15. Traffic camera system development

    NASA Astrophysics Data System (ADS)

    Hori, Toshi

    1997-04-01

    The intelligent transportation system has generated a strong need for the development of intelligent camera systems to meet the requirements of sophisticated applications, such as electronic toll collection (ETC), traffic violation detection and automatic parking lot control. In order to achieve the highest levels of accuracy in detection, these cameras must have high speed electronic shutters, high resolution, high frame rate, and communication capabilities. A progressive scan interline transfer CCD camera, with its high speed electronic shutter and resolution capabilities, provides the basic functions to meet the requirements of a traffic camera system. Unlike most industrial video imaging applications, traffic cameras must deal with harsh environmental conditions and an extremely wide range of light. Optical character recognition is a critical function of a modern traffic camera system, with detection and accuracy heavily dependent on the camera function. In order to operate under demanding conditions, communication and functional optimization is implemented to control cameras from a roadside computer. The camera operates with a shutter speed faster than 1/2000 sec. to capture highway traffic both day and night. Consequently camera gain, pedestal level, shutter speed and gamma functions are controlled by a look-up table containing various parameters based on environmental conditions, particularly lighting. Lighting conditions are studied carefully, to focus only on the critical license plate surface. A unique light sensor permits accurate reading under a variety of conditions, such as a sunny day, evening, twilight, storms, etc. These camera systems are being deployed successfully in major ETC projects throughout the world.

  16. Instrumentation optimization for positron emission mammography

    SciTech Connect

    Moses, William W.; Qi, Jinyi

    2003-06-05

    The past several years have seen designs for PET cameras optimized to image the breast, commonly known as Positron Emission Mammography or PEM cameras. The guiding principal behind PEM instrumentation is that a camera whose field of view is restricted to a single breast has higher performance and lower cost than a conventional PET camera. The most common geometry is a pair of parallel planes of detector modules, although geometries that encircle the breast have also been proposed. The ability of the detector modules to measure the depth of interaction (DOI) is also a relevant feature. This paper finds that while both the additional solid angle coverage afforded by encircling the breast and the decreased blurring afforded by the DOI measurement improve performance, the ability to measure DOI is more important than the ability to encircle the breast.

  17. Ringfield lithographic camera

    DOEpatents

    Sweatt, William C.

    1998-01-01

    A projection lithography camera is presented with a wide ringfield optimized so as to make efficient use of extreme ultraviolet radiation from a large area radiation source (e.g., D.sub.source .apprxeq.0.5 mm). The camera comprises four aspheric mirrors optically arranged on a common axis of symmetry with an increased etendue for the camera system. The camera includes an aperture stop that is accessible through a plurality of partial aperture stops to synthesize the theoretical aperture stop. Radiation from a mask is focused to form a reduced image on a wafer, relative to the mask, by reflection from the four aspheric mirrors.

  18. LSST Camera Optics Design

    SciTech Connect

    Riot, V J; Olivier, S; Bauman, B; Pratuch, S; Seppala, L; Gilmore, D; Ku, J; Nordby, M; Foss, M; Antilogus, P; Morgado, N

    2012-05-24

    The Large Synoptic Survey Telescope (LSST) uses a novel, three-mirror, telescope design feeding a camera system that includes a set of broad-band filters and three refractive corrector lenses to produce a flat field at the focal plane with a wide field of view. Optical design of the camera lenses and filters is integrated in with the optical design of telescope mirrors to optimize performance. We discuss the rationale for the LSST camera optics design, describe the methodology for fabricating, coating, mounting and testing the lenses and filters, and present the results of detailed analyses demonstrating that the camera optics will meet their performance goals.

  19. Transmission electron microscope CCD camera

    DOEpatents

    Downing, Kenneth H.

    1999-01-01

    In order to improve the performance of a CCD camera on a high voltage electron microscope, an electron decelerator is inserted between the microscope column and the CCD. This arrangement optimizes the interaction of the electron beam with the scintillator of the CCD camera while retaining optimization of the microscope optics and of the interaction of the beam with the specimen. Changing the electron beam energy between the specimen and camera allows both to be optimized.

  20. Single-camera stereo-digital image correlation with a four-mirror adapter: optimized design and validation

    NASA Astrophysics Data System (ADS)

    Yu, Liping; Pan, Bing

    2016-12-01

    A low-cost, easy-to-implement but practical single-camera stereo-digital image correlation (DIC) system using a four-mirror adapter is established for accurate shape and three-dimensional (3D) deformation measurements. The mirrors assisted pseudo-stereo imaging system can convert a single camera into two virtual cameras, which view a specimen from different angles and record the surface images of the test object onto two halves of the camera sensor. To enable deformation measurement in non-laboratory conditions or extreme high temperature environments, an active imaging optical design, combining an actively illuminated monochromatic source with a coupled band-pass optical filter, is compactly integrated to the pseudo-stereo DIC system. The optical design, basic principles and implementation procedures of the established system for 3D profile and deformation measurements are described in detail. The effectiveness and accuracy of the established system are verified by measuring the profile of a regular cylinder surface and displacements of a translated planar plate. As an application example, the established system is used to determine the tensile strains and Poisson's ratio of a composite solid propellant specimen during stress relaxation test. Since the established single-camera stereo-DIC system only needs a single camera and presents strong robustness against variations in ambient light or the thermal radiation of a hot object, it demonstrates great potential in determining transient deformation in non-laboratory or high-temperature environments with the aid of a single high-speed camera.

  1. Optical engineering application of modeled photosynthetically active radiation (PAR) for high-speed digital camera dynamic range optimization

    NASA Astrophysics Data System (ADS)

    Alves, James; Gueymard, Christian A.

    2009-08-01

    As efforts to create accurate yet computationally efficient estimation models for clear-sky photosynthetically active solar radiation (PAR) have succeeded, the range of practical engineering applications where these models can be successfully applied has increased. This paper describes a novel application of the REST2 radiative model (developed by the second author) in optical engineering. The PAR predictions in this application are used to predict the possible range of instantaneous irradiances that could impinge on the image plane of a stationary video camera designed to image license plates on moving vehicles. The overall spectral response of the camera (including lens and optical filters) is similar to the 400-700 nm PAR range, thereby making PAR irradiance (rather than luminance) predictions most suitable for this application. The accuracy of the REST2 irradiance predictions for horizontal surfaces, coupled with another radiative model to obtain irradiances on vertical surfaces, and to standard optical image formation models, enable setting the dynamic range controls of the camera to ensure that the license plate images are legible (unsaturated with adequate contrast) regardless of the time of day, sky condition, or vehicle speed. A brief description of how these radiative models are utilized as part of the camera control algorithm is provided. Several comparisons of the irradiance predictions derived from the radiative model versus actual PAR measurements under varying sky conditions with three Licor sensors (one horizontal and two vertical) have been made and showed good agreement. Various camera-to-plate geometries and compass headings have been considered in these comparisons. Time-lapse sequences of license plate images taken with the camera under various sky conditions over a 30-day period are also analyzed. They demonstrate the success of the approach at creating legible plate images under highly variable lighting, which is the main goal of this

  2. Optimizing the timing resolution of SiPM sensors for use in TOF-PET detectors

    NASA Astrophysics Data System (ADS)

    Vinke, R.; Löhner, H.; Schaart, D. R.; van Dam, H. T.; Seifert, S.; Beekman, F. J.; Dendooven, P.

    2009-10-01

    We have investigated the timing performance of Hamamatsu Multi-Pixel Photon Counter (MPPC) photosensors in light of their use in time-of-flight (TOF) positron emission tomography detectors. Measurements using picosecond laser pulses show a single photo-electron root-mean-square (RMS) timing resolution down to about 100 ps. In coincidences of 511 keV photons detected with an LYSO crystal coupled to a MPPC and a BaF 2 detector, an optimum FWHM timing resolution of 600 ps was obtained with leading edge time pickoff at the 1-1.5 photo-electron level. By optimizing the LYSO/MPPC coupling, this can be improved by a factor of 2. We further conclude that the use of stored digitized pulses allows great flexibility and efficiency in developing data analysis algorithms.

  3. MO-G-BRF-02: Enhancement of Texture-Based Metastasis Prediction Models Via the Optimization of PET/MRI Acquisition Protocols

    SciTech Connect

    Vallieres, M; Laberge, S; Levesque I, R; El Naqa, I

    2014-06-15

    Purpose: We have previously identified a prediction model of lung metastases at diagnosis of soft-tissue sarcomas (STS) that is composed of two textural features extracted from FDG-PET and T1-weighted (T1w) MRI scans. The goal of this study is to evaluate whether the optimization in FDGPET and MRI acquisition parameters would enhance the prediction performance of texture-based models. Methods: Ten FDG-PET and T1w- MRI digitized tumor models were generated from imaging data of STS patients who underwent pre-treatment clinical scans between 2005 and 2011. Five of ten patients eventually developed lung metastases. Numerically simulated MR images were produced using echo times (TE) of 2 and 4 times the nominal clinical parameter (TEc), and repetition times (TR) of 0.5, 0.67, 1.5 and 2 times the nominal clinical parameter (TRc) found in the DICOM headers (TEc range: 9–13 ms, TRc range: 410-667 ms). PET 2D images were simulated using Monte-Carlo and were reconstructed using an ordered-subsets expectation maximization (OSEM) algorithm with 1 to 32 iterations and a post-reconstruction Gaussian filter of 0, 2, 4 or 6 mm width. For all possible combinations of PET and MRI acquisition parameters, the prediction model was constructed using logistic regression with new coefficients, and its associated prediction performance for lung metastases was evaluated using the area under the ROC curve (AUC). Results: The prediction performance over all simulations yielded AUCs ranging from 0.7 to 1. Notably, TR values below or equal to TRc and higher PET post-reconstruction filter widths yielded higher prediction performance. The best results were obtained with a combination of 4*TEc, TRc, 30 OSEM iterations and 2mm filter width. Conclusion: This work indicates that texture-based metastasis prediction models could be improved using optimized choices of FDG-PET and MRI acquisition protocols. This principle could be generalized to other texture-based models.

  4. Camera Optics.

    ERIC Educational Resources Information Center

    Ruiz, Michael J.

    1982-01-01

    The camera presents an excellent way to illustrate principles of geometrical optics. Basic camera optics of the single-lens reflex camera are discussed, including interchangeable lenses and accessories available to most owners. Several experiments are described and results compared with theoretical predictions or manufacturer specifications.…

  5. Comparison of {sup 18}F-Fluorothymidine and {sup 18}F-Fluorodeoxyglucose PET/CT in Delineating Gross Tumor Volume by Optimal Threshold in Patients With Squamous Cell Carcinoma of Thoracic Esophagus

    SciTech Connect

    Han Dali; Yu Jinming; Yu Yonghua; Zhang Guifang; Zhong Xiaojun; Lu Jie; Yin Yong; Fu Zheng; Mu Dianbin; Zhang Baijiang; He Wei; Huo Zhijun; Liu Xijun; Kong Lei; Zhao Shuqiang; Sun Xiangyu

    2010-03-15

    Purpose: To determine the optimal method of using {sup 18}F-fluorothymidine (FLT) positron emission tomography (PET)/computed tomography (CT) simulation to delineate the gross tumor volume (GTV) in esophageal squamous cell carcinoma verified by pathologic examination and compare the results with those using {sup 18}F-fluorodeoxyglucose (FDG) PET/CT. Methods and Materials: A total of 22 patients were enrolled and underwent both FLT and FDG PET/CT. The GTVs with biologic information were delineated using seven different methods in FLT PET/CT and three different methods in FDG PET/CT. The results were compared with the pathologic gross tumor length, and the optimal threshold was obtained. Next, we compared the simulation plans using the optimal threshold of FLT and FDG PET/CT. The radiation dose was prescribed as 60 Gy in 30 fractions with a precise radiotherapy technique. Results: The mean +- standard deviation pathologic gross tumor length was 4.94 +- 2.21 cm. On FLT PET/CT, the length of the standardized uptake value 1.4 was 4.91 +- 2.43 cm. On FDG PET/CT, the length of the standardized uptake value 2.5 was 5.10 +- 2.18 cm, both of which seemed more approximate to the pathologic gross tumor length. The differences in the bilateral lung volume receiving >=20 Gy, heart volume receiving >=40 Gy, and the maximal dose received by spinal cord between FLT and FDG were not significant. However, the values for mean lung dose, bilateral lung volume receiving >=5, >=10, >=30, >=40, and >=50 Gy, mean heart dose, and heart volume receiving >=30 Gy using FLT PET/CT-based planning were significant lower than those using FDG PET/CT. Conclusion: A standardized uptake value cutoff of 1.4 on FLT PET/CT and one of 2.5 on FDG PET/CT provided the closest estimation of GTV length. Finally, FLT PET/CT-based treatment planning provided potential benefits to the lungs and heart.

  6. Ringfield lithographic camera

    DOEpatents

    Sweatt, W.C.

    1998-09-08

    A projection lithography camera is presented with a wide ringfield optimized so as to make efficient use of extreme ultraviolet radiation from a large area radiation source (e.g., D{sub source} {approx_equal} 0.5 mm). The camera comprises four aspheric mirrors optically arranged on a common axis of symmetry. The camera includes an aperture stop that is accessible through a plurality of partial aperture stops to synthesize the theoretical aperture stop. Radiation from a mask is focused to form a reduced image on a wafer, relative to the mask, by reflection from the four aspheric mirrors. 11 figs.

  7. Pet Health

    MedlinePlus

    ... Before getting a pet, think carefully about which animal is best for your family. What is each ... Does anyone have pet allergies? What type of animal suits your lifestyle and budget? Once you own ...

  8. Automated tumour boundary delineation on 18F-FDG PET images using active contour coupled with shifted-optimal thresholding method

    NASA Astrophysics Data System (ADS)

    Khamwan, Kitiwat; Krisanachinda, Anchali; Pluempitiwiriyawej, Charnchai

    2012-10-01

    This study presents an automatic method to trace the boundary of the tumour in positron emission tomography (PET) images. It has been discovered that Otsu's threshold value is biased when the within-class variances between the object and the background are significantly different. To solve the problem, a double-stage threshold search that minimizes the energy between the first Otsu's threshold and the maximum intensity value is introduced. Such shifted-optimal thresholding is embedded into a region-based active contour so that both algorithms are performed consecutively. The efficiency of the method is validated using six sphere inserts (0.52-26.53 cc volume) of the IEC/2001 torso phantom. Both spheres and phantom were filled with 18F solution with four source-to-background ratio (SBR) measurements of PET images. The results illustrate that the tumour volumes segmented by combined algorithm are of higher accuracy than the traditional active contour. The method had been clinically implemented in ten oesophageal cancer patients. The results are evaluated and compared with the manual tracing by an experienced radiation oncologist. The advantage of the algorithm is the reduced erroneous delineation that improves the precision and accuracy of PET tumour contouring. Moreover, the combined method is robust, independent of the SBR threshold-volume curves, and it does not require prior lesion size measurement.

  9. Region specific optimization of continuous linear attenuation coefficients based on UTE (RESOLUTE): application to PET/MR brain imaging.

    PubMed

    Ladefoged, Claes N; Benoit, Didier; Law, Ian; Holm, Søren; Kjær, Andreas; Højgaard, Liselotte; Hansen, Adam E; Andersen, Flemming L

    2015-10-21

    The reconstruction of PET brain data in a PET/MR hybrid scanner is challenging in the absence of transmission sources, where MR images are used for MR-based attenuation correction (MR-AC). The main challenge of MR-AC is to separate bone and air, as neither have a signal in traditional MR images, and to assign the correct linear attenuation coefficient to bone. The ultra-short echo time (UTE) MR sequence was proposed as a basis for MR-AC as this sequence shows a small signal in bone. The purpose of this study was to develop a new clinically feasible MR-AC method with patient specific continuous-valued linear attenuation coefficients in bone that provides accurate reconstructed PET image data. A total of 164 [(18)F]FDG PET/MR patients were included in this study, of which 10 were used for training. MR-AC was based on either standard CT (reference), UTE or our method (RESOLUTE). The reconstructed PET images were evaluated in the whole brain, as well as regionally in the brain using a ROI-based analysis. Our method segments air, brain, cerebral spinal fluid, and soft tissue voxels on the unprocessed UTE TE images, and uses a mapping of R(*)2 values to CT Hounsfield Units (HU) to measure the density in bone voxels. The average error of our method in the brain was 0.1% and less than 1.2% in any region of the brain. On average 95% of the brain was within  ±10% of PETCT, compared to 72% when using UTE. The proposed method is clinically feasible, reducing both the global and local errors on the reconstructed PET images, as well as limiting the number and extent of the outliers.

  10. Region specific optimization of continuous linear attenuation coefficients based on UTE (RESOLUTE): application to PET/MR brain imaging

    NASA Astrophysics Data System (ADS)

    Ladefoged, Claes N.; Benoit, Didier; Law, Ian; Holm, Søren; Kjær, Andreas; Højgaard, Liselotte; Hansen, Adam E.; Andersen, Flemming L.

    2015-10-01

    The reconstruction of PET brain data in a PET/MR hybrid scanner is challenging in the absence of transmission sources, where MR images are used for MR-based attenuation correction (MR-AC). The main challenge of MR-AC is to separate bone and air, as neither have a signal in traditional MR images, and to assign the correct linear attenuation coefficient to bone. The ultra-short echo time (UTE) MR sequence was proposed as a basis for MR-AC as this sequence shows a small signal in bone. The purpose of this study was to develop a new clinically feasible MR-AC method with patient specific continuous-valued linear attenuation coefficients in bone that provides accurate reconstructed PET image data. A total of 164 [18F]FDG PET/MR patients were included in this study, of which 10 were used for training. MR-AC was based on either standard CT (reference), UTE or our method (RESOLUTE). The reconstructed PET images were evaluated in the whole brain, as well as regionally in the brain using a ROI-based analysis. Our method segments air, brain, cerebral spinal fluid, and soft tissue voxels on the unprocessed UTE TE images, and uses a mapping of R2* values to CT Hounsfield Units (HU) to measure the density in bone voxels. The average error of our method in the brain was 0.1% and less than 1.2% in any region of the brain. On average 95% of the brain was within  ±10% of PETCT, compared to 72% when using UTE. The proposed method is clinically feasible, reducing both the global and local errors on the reconstructed PET images, as well as limiting the number and extent of the outliers.

  11. Optimization of PET activation studies based on the SNR measured in the 3-D Hoffman brain phantom.

    PubMed

    Li, H H; Votaw, J R

    1998-08-01

    This work investigates the noise properties of O-15 water PET images in an attempt to increase the sensitivity of activation studies. A method for computing the amount of noise within a region of interest (ROI) from the uncertainty in the raw data was implemented for three-dimensional (3-D) positron emission tomography (PET). The method was used to study the signal-to-noise ratio (SNR) of regions-of-interest (ROI's) inside a 3-D Hoffman brain phantom. Saturation occurs at an activity concentration of 2.2 mCi/l which corresponds to a 75-mCi O-15 water injection into a normal person of average weight. This establishes the upper limit for injections for human brain studies using 3-D PET on the Siemens ECAT 921 EXACT scanner. Data from human brain activation studies on four normal volunteers using two-dimensional (2-D) PET were analyzed. The biological variation was found to be 5% in 1-ml ROI's. The variance for a complete activation study was calculated, for a variety of protocols, by combining the Poisson noise propagated from the raw data in the phantom experiments with the biological variation. A protocol that is predicted to maximize the SNR in dual-condition activation experiments while remaining below the radiation safety limit is: ten scans with 45 mCi per injection. The data should not be corrected for random or scatter events since they do not help in the identification of activation sites while they do add noise to the image. Due to the lower noise level of 3-D PET, the threshold for detecting a true change in activity concentration is 10%-20% lower than 2-D PET. Because of this, a 3-D activation experiment using the Siemens 921 scanner requires fewer subjects for equal statistical power.

  12. Optimization of methods for quantification of rCBF using high-resolution [15O]H2O PET images

    NASA Astrophysics Data System (ADS)

    Walker, M. D.; Feldmann, M.; Matthews, J. C.; Anton-Rodriguez, J. M.; Wang, S.; Koepp, M. J.; Asselin, M.-C.

    2012-04-01

    This study aimed to derive accurate estimates of regional cerebral blood flow (rCBF) from noisy dynamic [15O]H2O PET images acquired on the high-resolution research tomograph, while retaining as much as possible the high spatial resolution of this brain scanner (2-3 mm) in parametric maps of rCBF. The PET autoradiographic method and generalized linear least-squares (GLLS), with fixed or extended to include spatially variable estimates of the dispersion of the measured input function, were compared to nonlinear least-squares (NLLS) for rCBF estimation. Six healthy volunteers underwent two [15O]H2O PET scans with continuous arterial blood sampling. rCBF estimates were obtained from three image reconstruction methods (one analytic and two iterative, of which one includes a resolution model) to which a range of post-reconstruction filters (3D Gaussian: 2, 4 and 6 mm FWHM) were applied. The optimal injected activity was estimated to be around 11 MBq kg-1 (800 MBq) by extrapolation of patient-specific noise equivalent count rates. Whole-brain rCBF values were found to be relatively insensitive to the method of reconstruction and rCBF quantification. The grey and white matter rCBF for analytic reconstruction and NLLS were 0.44 ± 0.03 and 0.15 ± 0.03 mL min-1 cm-3, respectively, in agreement with literature values. Similar values were obtained from the other methods. For generation of parametric images using GLLS or the autoradiographic method, a filter of ⩾4 mm was required in order to suppress noise in the PET images which otherwise produced large biases in the rCBF estimates.

  13. Experimental Demonstration of Extended Depth-of-Field F/1.2 Visible High Definition Camera with Jointly Optimized Phase Mask and Real-Time Digital Processing

    NASA Astrophysics Data System (ADS)

    Burcklen, M.-A.; Diaz, F.; Lepretre, F.; Rollin, J.; Delboulbé, A.; Lee, M.-S. L.; Loiseaux, B.; Koudoli, A.; Denel, S.; Millet, P.; Duhem, F.; Lemonnier, F.; Sauer, H.; Goudail, F.

    2015-10-01

    Increasing the depth of field (DOF) of compact visible high resolution cameras while maintaining high imaging performance in the DOF range is crucial for such applications as night vision goggles or industrial inspection. In this paper, we present the end-to-end design and experimental validation of an extended depth-of-field visible High Definition camera with a very small f-number, combining a six-ring pyramidal phase mask in the aperture stop of the lens with a digital deconvolution. The phase mask and the deconvolution algorithm are jointly optimized during the design step so as to maximize the quality of the deconvolved image over the DOF range. The deconvolution processing is implemented in real-time on a Field-Programmable Gate Array and we show that it requires very low power consumption. By mean of MTF measurements and imaging experiments we experimentally characterize the performance of both cameras with and without phase mask and thereby demonstrate a significant increase in depth of field of a factor 2.5, as it was expected in the design step.

  14. Study of PET scanner designs using clinical metrics to optimize the scanner axial FOV and crystal thickness

    NASA Astrophysics Data System (ADS)

    Surti, S.; Werner, M. E.; Karp, J. S.

    2013-06-01

    The aim of this study is to understand the trade-off between crystal thickness and scanner axial field-of-view FOV (AFOV) for clinical PET imaging. Clinical scanner design has evolved towards 20-25 mm thick crystals and 16-22 cm long scanner AFOV, as well as time-of-flight (TOF) imaging. While Monte Carlo studies demonstrate that longer AFOV and thicker crystals will lead to higher scanner sensitivity, cost has prohibited the building of commercial scanners with >22 cm AFOV. In this study, we performed a series of system simulations to optimize the use of a given amount of crystal material by evaluating the impact on system sensitivity and noise equivalent counts (NEC), as well as image quality in terms of lesion detectability. We evaluated two crystal types (LSO and LaBr3) and fixed the total crystal volume used for each type (8.2 L of LSO and 17.1 L of LaBr3) while varying the crystal thickness and scanner AFOV. In addition, all imaging times were normalized so that the total scan time needed to scan a 100 cm long object with multiple bed positions was kept constant. Our results show that the highest NEC cm-1 in a 35 cm diameter ×70 cm long line source cylinder is achieved for an LSO scanner with 10 mm long crystals and AFOV of 36 cm, while for LaBr3 scanners, the highest NEC cm-1 is obtained with 20 mm long crystals and an AFOV of 38 cm. Lesion phantom simulations show that the best lesion detection performance is achieved in scanners with long AFOV (≥36 cm) and using thin crystals (≤10 mm of LSO and ≤20 mm of LaBr3). This is due to a combination of improved NEC, as well as improved lesion contrast estimation due to better spatial resolution in thinner crystals. Alternatively, for lesion detection performance similar to that achieved in standard clinical scanner designs, the long AFOV scanners can be used to reduce the total scan time without increasing the amount of crystal used in the scanner. In addition, for LaBr3 based scanners, the reduced lesion

  15. Study of PET scanner designs using clinical metrics to optimize the scanner axial FOV and crystal thickness

    PubMed Central

    Surti, S; Werner, M E; Karp, J S

    2013-01-01

    The aim of this study is to understand the trade-off between crystal thickness and scanner axial FOV (AFOV) for clinical PET imaging. Clinical scanner design has evolved towards 20–25 mm thick crystals and 16–22 cm long scanner AFOV, as well as time-of-flight (TOF) imaging. While Monte Carlo studies demonstrate that longer AFOV and thicker crystals will lead to higher scanner sensitivity, cost has prohibited the building of commercial scanners with > 22 cm AFOV. In this study, we performed a series of system simulations to optimize the use of a given amount of crystal material by evaluating the impact on system sensitivity and NEC, as well image quality in terms of lesion detectability. We evaluated two crystal types (LSO and LaBr3) and fixed the total crystal volume used for each type (8.2 liters of LSO and 17.1 liters of LaBr3) while varying the crystal thickness and scanner AFOV. In addition, all imaging times were normalized so that the total scan time needed to scan a 100 cm long object with multiple bed positions was kept constant. Our results show that the highest NEC/cm in a 35 cm diameter×70 cm long line source cylinder is achieved for an LSO scanner with 10 mm long crystals and AFOV of 36 cm while for LaBr3 scanners, the highest NEC/cm is obtained with 20 mm long crystals and an AFOV of 38 cm. Lesion phantom simulations show best lesion detection performance is achieved in scanners with long AFOV (≥ 36 cm) and using thin crystals (≤ 10 mm of LSO and ≤ 20 mm of LaBr3). This is due to a combination of improved NEC, as well as improved lesion contrast estimation due to better spatial resolution in thinner crystals. Alternatively, for lesion detection performance similar to that achieved in standard clinical scanner designs, the long AFOV scanners can be used to reduce the total scan time without increasing the amount of crystal used in the scanner. In addition, for LaBr3 based scanners, the reduced lesion contrast relative to LSO based scanners

  16. Gallium-68 EDTA PET/CT for Renal Imaging.

    PubMed

    Hofman, Michael S; Hicks, Rodney J

    2016-09-01

    Nuclear medicine renal imaging provides important functional data to assist in the diagnosis and management of patients with a variety of renal disorders. Physiologically stable metal chelates like ethylenediaminetetraacetic acid (EDTA) and diethylenetriamine penta-acetate (DTPA) are excreted by glomerular filtration and have been radiolabelled with a variety of isotopes for imaging glomerular filtration and quantitative assessment of glomerular filtration rate. Gallium-68 ((68)Ga) EDTA PET usage predates Technetium-99m ((99m)Tc) renal imaging, but virtually disappeared with the widespread adoption of gamma camera technology that was not optimal for imaging positron decay. There is now a reemergence of interest in (68)Ga owing to the greater availability of PET technology and use of (68)Ga to label other radiotracers. (68)Ga EDTA can be used a substitute for (99m)Tc DTPA for wide variety of clinical indications. A key advantage of PET for renal imaging over conventional scintigraphy is 3-dimensional dynamic imaging, which is particularly helpful in patients with complex anatomy in whom planar imaging may be nondiagnostic or difficult to interpret owing to overlying structures containing radioactive urine that cannot be differentiated. Other advantages include accurate and absolute (rather than relative) camera-based quantification, superior spatial and temporal resolution and integrated multislice CT providing anatomical correlation. Furthermore, the (68)Ga generator enables on-demand production at low cost, with no additional patient radiation exposure compared with conventional scintigraphy. Over the past decade, we have employed (68)Ga EDTA PET/CT primarily to answer difficult clinical questions in patients in whom other modalities have failed, particularly when it was envisaged that dynamic 3D imaging would be of assistance. We have also used it as a substitute for (99m)Tc DTPA if unavailable owing to supply issues, and have additionally examined the role of

  17. AX-PET: A novel PET concept with G-APD readout

    NASA Astrophysics Data System (ADS)

    Bolle, E.; Casella, C.; Chesi, E.; De Leo, R.; Dissertori, G.; Fanti, V.; Gillam, J. E.; Heller, M.; Joram, C.; Lustermann, W.; Nappi, E.; Oliver, J. F.; Pauss, F.; Rafecas, M.; Rudge, A.; Ruotsalainen, U.; Schinzel, D.; Schneider, T.; Séguinot, J.; Solevi, P.; Stapnes, S.; Tuna, U.; Weilhammer, P.

    2012-12-01

    The AX-PET collaboration has developed a novel concept for high resolution PET imaging to overcome some of the performance limitations of classical PET cameras, in particular the compromise between spatial resolution and sensitivity introduced by the parallax error. The detector consists of an arrangement of long LYSO scintillating crystals axially oriented around the field of view together with arrays of wave length shifter strips orthogonal to the crystals. This matrix allows a precise 3D measurement of the photon interaction point. This is valid both for photoelectric absorption at 511 keV and for Compton scattering down to deposited energies of about 100 keV. Crystals and WLS strips are individually read out using Geiger-mode Avalanche Photo Diodes (G-APDs). The sensitivity of such a detector can be adjusted by changing the number of layers and the resolution is defined by the crystal and strip dimensions. Two AX-PET modules were built and fully characterized in dedicated test set-ups at CERN, with point-like 22Na sources. Their performance in terms of energy (Renergy≈11.8% (FWMH) at 511 keV) and spatial resolution was assessed (σaxial≈0.65 mm), both individually and for the two modules in coincidence. Test campaigns at ETH Zurich and at the company AAA allowed the tomographic reconstructions of more complex phantoms validating the 3D reconstruction algorithms. The concept of the AX-PET modules will be presented together with some characterization results. We describe a count rate model which allows to optimize the planing of the tomographic scans.

  18. Optimizing geometric accuracy of four-dimensional CT scans acquired using the wall- and couch-mounted Varian® Real-time Position Management™ camera systems

    PubMed Central

    Irvine, D M; Cole, A J; Hanna, G G; McGarry, C K

    2015-01-01

    Objective: The aim of this study was to identify sources of anatomical misrepresentation owing to the location of camera mounting, tumour motion velocity and image processing artefacts in order to optimize the four-dimensional CT (4DCT) scan protocol and improve geometrical–temporal accuracy. Methods: A phantom with an imaging insert was driven with a sinusoidal superior–inferior motion of varying amplitude and period for 4DCT scanning. The length of a high-density cube within the insert was measured using treatment planning software to determine the accuracy of its spatial representation. Scan parameters were varied, including the tube rotation period and the cine time between reconstructed images. A CT image quality phantom was used to measure various image quality signatures under the scan parameters tested. Results: No significant difference in spatial accuracy was found for 4DCT scans carried out using the wall- or couch-mounted camera for sinusoidal target motion. Greater spatial accuracy was found for 4DCT scans carried out using a tube rotation speed of 0.5 s rather than 1.0 s. The reduction in image quality when using a faster rotation speed was not enough to require an increase in patient dose. Conclusion: The 4DCT accuracy may be increased by optimizing scan parameters, including choosing faster tube rotation speeds. Peak misidentification in the recorded breathing trace may lead to spatial artefacts, and this risk can be reduced by using a couch-mounted infrared camera. Advances in knowledge: This study explicitly shows that 4DCT scan accuracy is improved by scanning with a faster CT tube rotation speed. PMID:25470359

  19. Advances in Clinical PET/MRI Instrumentation.

    PubMed

    Herzog, Hans; Lerche, Christoph

    2016-04-01

    In 2010, the first whole-body PET/MRI scanners installed for clinical use were the sequential Philips PET/MRI with PMT-based, TOF-capable technology and the integrated simultaneous Siemens PET/MRI. Avalanche photodiodes as non-magneto-sensitive readout electronics allowed PET integrated within the MRI. The experiences with these scanners showed that improvements of software aspects, such as attenuation correction, were necessary and that efficient protocols combining optimally PET and MRI must be still developed. In 2014, General Electric issued an integrated PET/MRI with SiPM-based PET detectors, allowing TOF-PET. Looking at the MRI components of current PET/MR imaging systems, primary improvements come from sequences and new coils.

  20. Are Pets in the Bedroom a Problem?

    PubMed

    Krahn, Lois E; Tovar, M Diane; Miller, Bernie

    2015-12-01

    The presence of pets in the bedroom can alter the sleep environment in ways that could affect sleep. Data were collected by questionnaire and interview from 150 consecutive patients seen at the Center for Sleep Medicine, Mayo Clinic in Arizona. Seventy-four people (49%) reported having pets, with 31 (41% of pet owners) having multiple pets. More than half of pet owners (56%) allowed their pets to sleep in the bedroom. Fifteen pet owners (20%) described their pets as disruptive, whereas 31 (41%) perceived their pets as unobtrusive or even beneficial to sleep. Health care professionals working with patients with sleep concerns should inquire about the presence of companion animals in the sleep environment to help them find solutions and optimize their sleep.

  1. Optimization of a Pretargeted Strategy for the PET Imaging of Colorectal Carcinoma via the Modulation of Radioligand Pharmacokinetics.

    PubMed

    Zeglis, Brian M; Brand, Christian; Abdel-Atti, Dalya; Carnazza, Kathryn E; Cook, Brendon E; Carlin, Sean; Reiner, Thomas; Lewis, Jason S

    2015-10-05

    Pretargeted PET imaging has emerged as an effective strategy for merging the exquisite selectivity of antibody-based targeting vectors with the rapid pharmacokinetics of radiolabeled small molecules. We previously reported the development of a strategy for the pretargeted PET imaging of colorectal cancer based on the bioorthogonal inverse electron demand Diels-Alder reaction between a tetrazine-bearing radioligand and a transcyclooctene-modified huA33 immunoconjugate. Although this method effectively delineated tumor tissue, its clinical potential was limited by the somewhat sluggish clearance of the radioligand through the gastrointestinal tract. Herein, we report the development and in vivo validation of a pretargeted strategy for the PET imaging of colorectal carcinoma with dramatically improved pharmacokinetics. Two novel tetrazine constructs, Tz-PEG7-NOTA and Tz-SarAr, were synthesized, characterized, and radiolabeled with (64)Cu in high yield (>90%) and radiochemical purity (>99%). PET imaging and biodistribution experiments in healthy mice revealed that although (64)Cu-Tz-PEG7-NOTA is cleared via both the gastrointestinal and urinary tracts, (64)Cu-Tz-SarAr is rapidly excreted by the renal system alone. On this basis, (64)Cu-Tz-SarAr was selected for further in vivo evaluation. To this end, mice bearing A33 antigen-expressing SW1222 human colorectal carcinoma xenografts were administered huA33-TCO, and the immunoconjugate was given 24 h to accumulate at the tumor and clear from the blood, after which (64)Cu-Tz-SarAr was administered via intravenous tail vein injection. PET imaging and biodistribution experiments revealed specific uptake of the radiotracer in the tumor at early time points (5.6 ± 0.7 %ID/g at 1 h p.i.), high tumor-to-background activity ratios, and rapid elimination of unclicked radioligand. Importantly, experiments with longer antibody accumulation intervals (48 and 120 h) yielded slight decreases in tumoral uptake but also concomitant

  2. Experimental evaluation and basis function optimization of the spatially variant image-space PSF on the Ingenuity PET/MR scanner

    SciTech Connect

    Kotasidis, Fotis A.; Zaidi, Habib

    2014-06-15

    Purpose: The Ingenuity time-of-flight (TF) PET/MR is a recently developed hybrid scanner combining the molecular imaging capabilities of PET with the excellent soft tissue contrast of MRI. It is becoming common practice to characterize the system's point spread function (PSF) and understand its variation under spatial transformations to guide clinical studies and potentially use it within resolution recovery image reconstruction algorithms. Furthermore, due to the system's utilization of overlapping and spherical symmetric Kaiser-Bessel basis functions during image reconstruction, its image space PSF and reconstructed spatial resolution could be affected by the selection of the basis function parameters. Hence, a detailed investigation into the multidimensional basis function parameter space is needed to evaluate the impact of these parameters on spatial resolution. Methods: Using an array of 12 × 7 printed point sources, along with a custom made phantom, and with the MR magnet on, the system's spatially variant image-based PSF was characterized in detail. Moreover, basis function parameters were systematically varied during reconstruction (list-mode TF OSEM) to evaluate their impact on the reconstructed resolution and the image space PSF. Following the spatial resolution optimization, phantom, and clinical studies were subsequently reconstructed using representative basis function parameters. Results: Based on the analysis and under standard basis function parameters, the axial and tangential components of the PSF were found to be almost invariant under spatial transformations (∼4 mm) while the radial component varied modestly from 4 to 6.7 mm. Using a systematic investigation into the basis function parameter space, the spatial resolution was found to degrade for basis functions with a large radius and small shape parameter. However, it was found that optimizing the spatial resolution in the reconstructed PET images, while having a good basis function

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

    NASA Astrophysics Data System (ADS)

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

    2014-09-01

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

  4. Single Particle and PET-based Platform for Identifying Optimal Plasmonic Nano-Heaters for Photothermal Cancer Therapy

    NASA Astrophysics Data System (ADS)

    Jørgensen, Jesper Tranekjær; Norregaard, Kamilla; Tian, Pengfei; Bendix, Poul Martin; Kjaer, Andreas; Oddershede, Lene B.

    2016-08-01

    Plasmonic nanoparticle-based photothermal cancer therapy is a promising new tool to inflict localized and irreversible damage to tumor tissue by hyperthermia, without harming surrounding healthy tissue. We developed a single particle and positron emission tomography (PET)-based platform to quantitatively correlate the heat generation of plasmonic nanoparticles with their potential as cancer killing agents. In vitro, the heat generation and absorption cross-section of single irradiated nanoparticles were quantified using a temperature sensitive lipid-based assay and compared to their theoretically predicted photo-absorption. In vivo, the heat generation of irradiated nanoparticles was evaluated in human tumor xenografts in mice using 2-deoxy-2-[F-18]fluoro-D-glucose (18F-FDG) PET imaging. To validate the use of this platform, we quantified the photothermal efficiency of near infrared resonant silica-gold nanoshells (AuNSs) and benchmarked this against the heating of colloidal spherical, solid gold nanoparticles (AuNPs). As expected, both in vitro and in vivo the heat generation of the resonant AuNSs performed superior compared to the non-resonant AuNPs. Furthermore, the results showed that PET imaging could be reliably used to monitor early treatment response of photothermal treatment. This multidisciplinary approach provides a much needed platform to benchmark the emerging plethora of novel plasmonic nanoparticles for their potential for photothermal cancer therapy.

  5. Single Particle and PET-based Platform for Identifying Optimal Plasmonic Nano-Heaters for Photothermal Cancer Therapy

    PubMed Central

    Jørgensen, Jesper Tranekjær; Norregaard, Kamilla; Tian, Pengfei; Bendix, Poul Martin; Kjaer, Andreas; Oddershede, Lene B.

    2016-01-01

    Plasmonic nanoparticle-based photothermal cancer therapy is a promising new tool to inflict localized and irreversible damage to tumor tissue by hyperthermia, without harming surrounding healthy tissue. We developed a single particle and positron emission tomography (PET)-based platform to quantitatively correlate the heat generation of plasmonic nanoparticles with their potential as cancer killing agents. In vitro, the heat generation and absorption cross-section of single irradiated nanoparticles were quantified using a temperature sensitive lipid-based assay and compared to their theoretically predicted photo-absorption. In vivo, the heat generation of irradiated nanoparticles was evaluated in human tumor xenografts in mice using 2-deoxy-2-[F-18]fluoro-D-glucose (18F-FDG) PET imaging. To validate the use of this platform, we quantified the photothermal efficiency of near infrared resonant silica-gold nanoshells (AuNSs) and benchmarked this against the heating of colloidal spherical, solid gold nanoparticles (AuNPs). As expected, both in vitro and in vivo the heat generation of the resonant AuNSs performed superior compared to the non-resonant AuNPs. Furthermore, the results showed that PET imaging could be reliably used to monitor early treatment response of photothermal treatment. This multidisciplinary approach provides a much needed platform to benchmark the emerging plethora of novel plasmonic nanoparticles for their potential for photothermal cancer therapy. PMID:27481537

  6. Cardiac cameras.

    PubMed

    Travin, Mark I

    2011-05-01

    Cardiac imaging with radiotracers plays an important role in patient evaluation, and the development of suitable imaging instruments has been crucial. While initially performed with the rectilinear scanner that slowly transmitted, in a row-by-row fashion, cardiac count distributions onto various printing media, the Anger scintillation camera allowed electronic determination of tracer energies and of the distribution of radioactive counts in 2D space. Increased sophistication of cardiac cameras and development of powerful computers to analyze, display, and quantify data has been essential to making radionuclide cardiac imaging a key component of the cardiac work-up. Newer processing algorithms and solid state cameras, fundamentally different from the Anger camera, show promise to provide higher counting efficiency and resolution, leading to better image quality, more patient comfort and potentially lower radiation exposure. While the focus has been on myocardial perfusion imaging with single-photon emission computed tomography, increased use of positron emission tomography is broadening the field to include molecular imaging of the myocardium and of the coronary vasculature. Further advances may require integrating cardiac nuclear cameras with other imaging devices, ie, hybrid imaging cameras. The goal is to image the heart and its physiological processes as accurately as possible, to prevent and cure disease processes.

  7. Minimizing artifacts resulting from respiratory and cardiac motion by optimization of the transmission scan in cardiac PET/CT

    SciTech Connect

    Nye, Jonathon A.; Esteves, Fabio; Votaw, John R.

    2007-06-15

    The introduction of positron emission/computed tomography (PET/CT) systems coupled with multidetector CT arrays has greatly increased the amount of clinical information in myocardial perfusion studies. The CT acquisition serves the dual role of providing high spatial anatomical detail and attenuation correction for PET. However, the differences between the interaction of respiratory and cardiac cycles in the CT and PET acquisitions presents a challenge when using the CT to determine PET attenuation correction. Three CT attenuation correction protocols were tested for their ability to produce accurate emission images: gated, a step mode acquisition covering the diastolic heart phase; normal, a high-pitch helical CT; and slow, a low-pitch, low-temporal-resolution helical CT. The amount of cardiac tissue in the emission image that overlaid lung tissue in the transmission image was used as the measure of mismatch between acquisitions. Phantom studies simulating misalignment of the heart between the transmission and emission sequences were used to correlate the amount of mismatch with the artificial defect changes in the emission image. Consecutive patients were studied prospectively with either paired gated (diastolic phase, 120 kVp, 280 mA, 2.6 s) and slow CT (0.562:1 pitch, 120 kVp, Auto-mA, 16 s) or paired normal (0.938:1 pitch, 120 kVp, Auto-mA, 4.8 s) and slow CT protocols, prior to a Rb-82 perfusion study. To determine the amount of mismatch, the transmission and emission images were converted to binary representations of attenuating tissue and cardiac tissue and overlaid using their native registration. The number of cardiac tissue pixels from the emission image present in the CT lung field yielded the magnitude of misalignment represented in terms of volume, of where a small volume indicates better registration. Acquiring a slow CT improved registration between the transmission and emission acquisitions compared to the gated and normal CT protocols. The volume

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

    DTIC Science & Technology

    2005-04-01

    demand. while the PET camera was taking data. The gating trigger signals Many respiration-gating methods, such as video- camera - represent particular...programmable logic array. I. INTRODUCTION TI HE detection of coincident events is at the core of a (b) pston emission tomography (PET) camera . In... CAMERAS 1387 Up to 12 input trigger pulses Coincidence backplane ------- ---- ----- - --- --- ----incidence---Fast-- oin- id-n ---- Fast coincidence Ingl

  9. Optimizing light transport in scintillation crystals for time-of-flight PET: an experimental and optical Monte Carlo simulation study.

    PubMed

    Berg, Eric; Roncali, Emilie; Cherry, Simon R

    2015-06-01

    Achieving excellent timing resolution in gamma ray detectors is crucial in several applications such as medical imaging with time-of-flight positron emission tomography (TOF-PET). Although many factors impact the overall system timing resolution, the statistical nature of scintillation light, including photon production and transport in the crystal to the photodetector, is typically the limiting factor for modern scintillation detectors. In this study, we investigated the impact of surface treatment, in particular, roughening select areas of otherwise polished crystals, on light transport and timing resolution. A custom Monte Carlo photon tracking tool was used to gain insight into changes in light collection and timing resolution that were observed experimentally: select roughening configurations increased the light collection up to 25% and improved timing resolution by 15% compared to crystals with all polished surfaces. Simulations showed that partial surface roughening caused a greater number of photons to be reflected towards the photodetector and increased the initial rate of photoelectron production. This study provides a simple method to improve timing resolution and light collection in scintillator-based gamma ray detectors, a topic of high importance in the field of TOF-PET. Additionally, we demonstrated utility of our Monte Carlo simulation tool to accurately predict the effect of altering crystal surfaces on light collection and timing resolution.

  10. k-space sampling optimization for ultrashort TE imaging of cortical bone: Applications in radiation therapy planning and MR-based PET attenuation correction

    PubMed Central

    Hu, Lingzhi; Su, Kuan-Hao; Pereira, Gisele C.; Grover, Anu; Traughber, Bryan; Traughber, Melanie; Muzic, Raymond F.

    2014-01-01

    Purpose: The ultrashort echo-time (UTE) sequence is a promising MR pulse sequence for imaging cortical bone which is otherwise difficult to image using conventional MR sequences and also poses strong attenuation for photons in radiation therapy and PET imaging. The authors report here a systematic characterization of cortical bone signal decay and a scanning time optimization strategy for the UTE sequence through k-space undersampling, which can result in up to a 75% reduction in acquisition time. Using the undersampled UTE imaging sequence, the authors also attempted to quantitatively investigate the MR properties of cortical bone in healthy volunteers, thus demonstrating the feasibility of using such a technique for generating bone-enhanced images which can be used for radiation therapy planning and attenuation correction with PET/MR. Methods: An angularly undersampled, radially encoded UTE sequence was used for scanning the brains of healthy volunteers. Quantitative MR characterization of tissue properties, including water fraction and R2∗ = 1/T2∗, was performed by analyzing the UTE images acquired at multiple echo times. The impact of different sampling rates was evaluated through systematic comparison of the MR image quality, bone-enhanced image quality, image noise, water fraction, and R2∗ of cortical bone. Results: A reduced angular sampling rate of the UTE trajectory achieves acquisition durations in proportion to the sampling rate and in as short as 25% of the time required for full sampling using a standard Cartesian acquisition, while preserving unique MR contrast within the skull at the cost of a minimal increase in noise level. The R2∗ of human skull was measured as 0.2–0.3 ms−1 depending on the specific region, which is more than ten times greater than the R2∗ of soft tissue. The water fraction in human skull was measured to be 60%–80%, which is significantly less than the >90% water fraction in brain. High-quality, bone

  11. k-space sampling optimization for ultrashort TE imaging of cortical bone: Applications in radiation therapy planning and MR-based PET attenuation correction

    SciTech Connect

    Hu, Lingzhi E-mail: raymond.muzic@case.edu; Traughber, Melanie; Su, Kuan-Hao; Pereira, Gisele C.; Grover, Anu; Traughber, Bryan; Muzic, Raymond F. Jr. E-mail: raymond.muzic@case.edu

    2014-10-15

    Purpose: The ultrashort echo-time (UTE) sequence is a promising MR pulse sequence for imaging cortical bone which is otherwise difficult to image using conventional MR sequences and also poses strong attenuation for photons in radiation therapy and PET imaging. The authors report here a systematic characterization of cortical bone signal decay and a scanning time optimization strategy for the UTE sequence through k-space undersampling, which can result in up to a 75% reduction in acquisition time. Using the undersampled UTE imaging sequence, the authors also attempted to quantitatively investigate the MR properties of cortical bone in healthy volunteers, thus demonstrating the feasibility of using such a technique for generating bone-enhanced images which can be used for radiation therapy planning and attenuation correction with PET/MR. Methods: An angularly undersampled, radially encoded UTE sequence was used for scanning the brains of healthy volunteers. Quantitative MR characterization of tissue properties, including water fraction and R2{sup ∗} = 1/T2{sup ∗}, was performed by analyzing the UTE images acquired at multiple echo times. The impact of different sampling rates was evaluated through systematic comparison of the MR image quality, bone-enhanced image quality, image noise, water fraction, and R2{sup ∗} of cortical bone. Results: A reduced angular sampling rate of the UTE trajectory achieves acquisition durations in proportion to the sampling rate and in as short as 25% of the time required for full sampling using a standard Cartesian acquisition, while preserving unique MR contrast within the skull at the cost of a minimal increase in noise level. The R2{sup ∗} of human skull was measured as 0.2–0.3 ms{sup −1} depending on the specific region, which is more than ten times greater than the R2{sup ∗} of soft tissue. The water fraction in human skull was measured to be 60%–80%, which is significantly less than the >90% water fraction in

  12. Optimal design and experimental verification of a magnetically actuated optical image stabilization system for cameras in mobile phones

    NASA Astrophysics Data System (ADS)

    Chiu, Chi-Wei; Chao, Paul C.-P.; Kao, Nicholas Y.-Y.; Young, Fu-Kuan

    2008-04-01

    A novel miniaturized optical image stabilizer (OIS) is proposed, which is installed inside the limited inner space of a mobile phone. The relation between the VCM electromagnetic force inside the OIS and the applied voltage is first established via an equivalent circuit and further validated by a finite element model. Various dimensions of the VCMs are optimized by a genetic algorithm (GA) to maximize sensitivities and also achieving high uniformity of the magnetic flux intensity.

  13. High-Resolution PET Detector. Final report

    SciTech Connect

    Karp, Joel

    2014-03-26

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

  14. CCD Camera

    DOEpatents

    Roth, Roger R.

    1983-01-01

    A CCD camera capable of observing a moving object which has varying intensities of radiation eminating therefrom and which may move at varying speeds is shown wherein there is substantially no overlapping of successive images and wherein the exposure times and scan times may be varied independently of each other.

  15. CCD Camera

    DOEpatents

    Roth, R.R.

    1983-08-02

    A CCD camera capable of observing a moving object which has varying intensities of radiation emanating therefrom and which may move at varying speeds is shown wherein there is substantially no overlapping of successive images and wherein the exposure times and scan times may be varied independently of each other. 7 figs.

  16. Senior Pets

    MedlinePlus

    ... Health Awareness Events About AVMA Who We Are Governance AVMA Careers AVMF Student AVMA (SAVMA) Allied Organizations ... Although senior pets may develop age-related problems, good care allows them to live happy, healthy and ...

  17. Giardia & Pets

    MedlinePlus

    ... items (for example, bedding and cloth toys) and linens (sheets and towels) can be washed in the ... and food bowls, pet bedding, floors, dog crates, linens, towels, litter box, etc.) regularly for as long ...

  18. PET scan

    MedlinePlus

    ... may have an allergic reaction to the tracer material. Some people have pain, redness, or swelling at ... with diabetes. Most PET scans are now performed along with a CT scan. This combination scan ...

  19. [82 Rubidium PET to replace myocardial scintigraphy].

    PubMed

    Hasbak, Philip; Kjær, Andreas

    2011-02-21

    Since the 1970's nuclear cardiology has mainly been based on the use of gamma camera technology. While gamma cameras have undergone a rapid development, the number of perfusion tracers has been limited. In parallel, cardiac positron emission tomography (PET) has only been performed with short-lived isotopes at centres with access to a cyclotron, and only including a very limited number of patients. The number of PET scanners has increased markedly in Denmark and with the introduction of generator-produced 82-Rubidium, this modality may replace the traditional cardial single photon emission computed tomography (SPECT).

  20. Positron Emission Tomography (PET)

    DOE R&D Accomplishments Database

    Welch, M. J.

    1990-01-01

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

  1. Positron Emission Tomography (PET)

    SciTech Connect

    Welch, M.J.

    1990-01-01

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

  2. Optimising rigid motion compensation for small animal brain PET imaging

    NASA Astrophysics Data System (ADS)

    Spangler-Bickell, Matthew G.; Zhou, Lin; Kyme, Andre Z.; De Laat, Bart; Fulton, Roger R.; Nuyts, Johan

    2016-10-01

    Motion compensation (MC) in PET brain imaging of awake small animals is attracting increased attention in preclinical studies since it avoids the confounding effects of anaesthesia and enables behavioural tests during the scan. A popular MC technique is to use multiple external cameras to track the motion of the animal’s head, which is assumed to be represented by the motion of a marker attached to its forehead. In this study we have explored several methods to improve the experimental setup and the reconstruction procedures of this method: optimising the camera-marker separation; improving the temporal synchronisation between the motion tracker measurements and the list-mode stream; post-acquisition smoothing and interpolation of the motion data; and list-mode reconstruction with appropriately selected subsets. These techniques have been tested and verified on measurements of a moving resolution phantom and brain scans of an awake rat. The proposed techniques improved the reconstructed spatial resolution of the phantom by 27% and of the rat brain by 14%. We suggest a set of optimal parameter values to use for awake animal PET studies and discuss the relative significance of each parameter choice.

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

    SciTech Connect

    Kolb, A. Parl, C.; Liu, C. C.; Pichler, B. J.; Mantlik, F.; Lorenz, E.; Renker, D.

    2014-08-15

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

  4. Current Status of Hybrid PET/MRI in Oncologic Imaging

    PubMed Central

    Rosenkrantz, Andrew B.; Friedman, Kent; Chandarana, Hersh; Melsaether, Amy; Moy, Linda; Ding, Yu-Shin; Jhaveri, Komal; Beltran, Luis; Jain, Rajan

    2016-01-01

    OBJECTIVE This review article explores recent advancements in PET/MRI for clinical oncologic imaging. CONCLUSION Radiologists should understand the technical considerations that have made PET/MRI feasible within clinical workflows, the role of PET tracers for imaging various molecular targets in oncology, and advantages of hybrid PET/MRI compared with PET/CT. To facilitate this understanding, we discuss clinical examples (including gliomas, breast cancer, bone metastases, prostate cancer, bladder cancer, gynecologic malignancy, and lymphoma) as well as future directions, challenges, and areas for continued technical optimization for PET/MRI. PMID:26491894

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

    PubMed

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

    2016-01-14

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

  6. Pet Therapy.

    ERIC Educational Resources Information Center

    Kavanagh, Kim

    1994-01-01

    This resource guide presents information on a variety of ways that animals can be used as a therapeutic modality with people having disabilities. Aspects addressed include: pet ownership and selection criteria; dogs (including service dogs, hearing/signal dogs, seeing leader dogs, and social/specialty dogs); horseriding for both therapy and fun;…

  7. 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.

  8. MO-AB-206-01: PET Physics.

    PubMed

    Turkington, T

    2016-06-01

    This education session will cover the physics and operation principles of gamma cameras and PET scanners. The first talk will focus on PET imaging. An overview of the principles of PET imaging will be provided, including positron decay physics, and the transition from 2D to 3D imaging. More recent advances in hardware and software will be discussed, such as time-of-flight imaging, and improvements in reconstruction algorithms that provide for options such as depth-of-interaction corrections. Quantitative applications of PET will be discussed, as well as the requirements for doing accurate quantitation. Relevant performance tests will also be described.

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

    NASA Astrophysics Data System (ADS)

    Kolstein, M.; Chmeissani, M.

    2016-01-01

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

  10. Caught on Camera.

    ERIC Educational Resources Information Center

    Milshtein, Amy

    2002-01-01

    Describes the benefits of and rules to be followed when using surveillance cameras for school security. Discusses various camera models, including indoor and outdoor fixed position cameras, pan-tilt zoom cameras, and pinhole-lens cameras for covert surveillance. (EV)

  11. Birds Kept as Pets

    MedlinePlus

    ... Pets Pets Birds Cats Dogs Farm Animals Backyard Poultry Ferrets Fish Horses Reptiles and Amphibians Turtles Kept ... as pets can be found on the backyard poultry page. Overview Diseases Prevention More Information Boy admiring ...

  12. OSSI-PET: Open-Access Database of Simulated [(11)C]Raclopride Scans for the Inveon Preclinical PET Scanner: Application to the Optimization of Reconstruction Methods for Dynamic Studies.

    PubMed

    Garcia, Marie-Paule; Charil, Arnaud; Callaghan, Paul; Wimberley, Catriona; Busso, Florian; Gregoire, Marie-Claude; Bardies, Manuel; Reilhac, Anthonin

    2016-07-01

    A wide range of medical imaging applications benefits from the availability of realistic ground truth data. In the case of positron emission tomography (PET), ground truth data is crucial to validate processing algorithms and assessing their performances. The design of such ground truth data often relies on Monte-Carlo simulation techniques. Since the creation of a large dataset is not trivial both in terms of computing time and realism, we propose the OSSI-PET database containing 350 simulated [(11)C]Raclopride dynamic scans for rats, created specifically for the Inveon pre-clinical PET scanner. The originality of this database lies on the availability of several groups of scans with controlled biological variations in the striata. Besides, each group consists of a large number of realizations (i.e., noise replicates). We present the construction methodology of this database using rat pharmacokinetic and anatomical models. A first application using the OSSI-PET database is presented. Several commonly used reconstruction techniques were compared in terms of image quality, accuracy and variability of the activity estimates and of the computed kinetic parameters. The results showed that OP-OSEM3D iterative reconstruction method outperformed the other tested methods. Analytical methods such as FBP2D and 3DRP also produced satisfactory results. However, FORE followed by OSEM2D reconstructions should be avoided. Beyond the illustration of the potential of the database, this application will help scientists to understand the different sources of noise and bias that can occur at the different steps in the processing and will be very useful for choosing appropriate reconstruction methods and parameters.

  13. PAU camera: detectors characterization

    NASA Astrophysics Data System (ADS)

    Casas, Ricard; Ballester, Otger; Cardiel-Sas, Laia; Castilla, Javier; Jiménez, Jorge; Maiorino, Marino; Pío, Cristóbal; Sevilla, Ignacio; de Vicente, Juan

    2012-07-01

    The PAU Camera (PAUCam) [1,2] is a wide field camera that will be mounted at the corrected prime focus of the William Herschel Telescope (Observatorio del Roque de los Muchachos, Canary Islands, Spain) in the next months. The focal plane of PAUCam is composed by a mosaic of 18 CCD detectors of 2,048 x 4,176 pixels each one with a pixel size of 15 microns, manufactured by Hamamatsu Photonics K. K. This mosaic covers a field of view (FoV) of 60 arcmin (minutes of arc), 40 of them are unvignetted. The behaviour of these 18 devices, plus four spares, and their electronic response should be characterized and optimized for the use in PAUCam. This job is being carried out in the laboratories of the ICE/IFAE and the CIEMAT. The electronic optimization of the CCD detectors is being carried out by means of an OG (Output Gate) scan and maximizing it CTE (Charge Transfer Efficiency) while the read-out noise is minimized. The device characterization itself is obtained with different tests. The photon transfer curve (PTC) that allows to obtain the electronic gain, the linearity vs. light stimulus, the full-well capacity and the cosmetic defects. The read-out noise, the dark current, the stability vs. temperature and the light remanence.

  14. The virtual gamma camera room.

    PubMed

    Penrose, J M; Trowbridge, E A; Tindale, W B

    1996-05-01

    The installation of a gamma camera is time-consuming and costly and, once installed, the camera position is unlikely to be altered during its working life. Poor choice of camera position therefore has long-term consequences. Additional equipment such as collimators and carts, the operator's workstation and wall-mounted display monitors must also be situated to maximize access and ease of use. The layout of a gamma camera room can be optimized prior to installation by creating a virtual environment. Super-Scape VRT software running on an upgraded 486 PC microprocessor was used to create a 'virtual camera room'. The simulation included an operator's viewpoint and a controlled tour of the room. Equipment could be repositioned as required, allowing potential problems to be identified at the design stage. Access for bed-ridden patients, operator ergonomics, operator and patient visibility were addressed. The display can also be used for patient education. Creation of a virtual environment is a valuable tool which allows different camera systems to be compared interactively in terms of dimensions, extent of movement and use of a defined space. Such a system also has applications in radiopharmacy design and simulation.

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

    ERIC Educational Resources Information Center

    Soltow, Willow

    1984-01-01

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

  16. Fundamental Limits of Spatial Resolution in PET

    PubMed Central

    Moses, William W.

    2010-01-01

    The fundamental limits of spatial resolution in positron emission tomography (PET) have been understood for many years. The physical size of the detector element usually plays the dominant role in determining resolution, but the combined contributions from acollinearity, positron range, penetration into the detector ring, and decoding errors in the detector modules often combine to be of similar size. In addition, the sampling geometry and statistical noise further degrade the effective resolution. This paper describes quantitatively describes these effects, discusses potential methods for reducing the magnitude of these effects, and computes the ultimately achievable spatial resolution for clinical and pre-clinical PET cameras. PMID:21804677

  17. Pets for Handicapped Children.

    ERIC Educational Resources Information Center

    Frith, Greg H.

    1982-01-01

    Pets can provide valuable learning for handicapped children, but selection of a type of pet should consider cost, availability and care, parents' attitudes, locality, the animal's susceptibility to training, pet's life expectancy, and the child's handicap and emotional maturity. Suggested pet-related activities are listed. (CL)

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

    DTIC Science & Technology

    2012-07-01

    recognized in both emission modalities, SPECT and PET. Compton camera is a subspecies of SPECT, where a silicon based scatter as a MR compatible part...exploit their advantages while compensat- ing for their drawbacks. Two specific arrangements are presented, a Compton camera with silicon detectors [4...direction of the field due to circular motion of the positrons. A brief summary of the study will be presented. 2. Compton camera Compton camera is a

  19. Determining Camera Gain in Room Temperature Cameras

    SciTech Connect

    Joshua Cogliati

    2010-12-01

    James R. Janesick provides a method for determining the amplification of a CCD or CMOS camera when only access to the raw images is provided. However, the equation that is provided ignores the contribution of dark current. For CCD or CMOS cameras that are cooled well below room temperature, this is not a problem, however, the technique needs adjustment for use with room temperature cameras. This article describes the adjustment made to the equation, and a test of this method.

  20. Short-lived positron emitters in beam-on PET imaging during proton therapy.

    PubMed

    Dendooven, P; Buitenhuis, H J T; Diblen, F; Heeres, P N; Biegun, A K; Fiedler, F; van Goethem, M-J; van der Graaf, E R; Brandenburg, S

    2015-12-07

    The only method for in vivo dose delivery verification in proton beam radiotherapy in clinical use today is positron emission tomography (PET) of the positron emitters produced in the patient during irradiation. PET imaging while the beam is on (so called beam-on PET) is an attractive option, providing the largest number of counts, the least biological washout and the fastest feedback. In this implementation, all nuclides, independent of their half-life, will contribute. As a first step towards assessing the relevance of short-lived nuclides (half-life shorter than that of (10)C, T1/2  =  19 s) for in vivo dose delivery verification using beam-on PET, we measured their production in the stopping of 55 MeV protons in water, carbon, phosphorus and calcium The most copiously produced short-lived nuclides and their production rates relative to the relevant long-lived nuclides are: (12)N (T1/2  =  11 ms) on carbon (9% of (11)C), (29)P (T1/2  =  4.1 s) on phosphorus (20% of (30)P) and (38m)K (T1/2  =  0.92 s) on calcium (113% of (38g)K). No short-lived nuclides are produced on oxygen. The number of decays integrated from the start of an irradiation as a function of time during the irradiation of PMMA and 4 tissue materials has been determined. For (carbon-rich) adipose tissue, (12)N dominates up to 70 s. On bone tissue, (12)N dominates over (15)O during the first 8-15 s (depending on carbon-to-oxygen ratio). The short-lived nuclides created on phosphorus and calcium provide 2.5 times more beam-on PET counts than the long-lived ones produced on these elements during a 70 s irradiation. From the estimated number of (12)N PET counts, we conclude that, for any tissue, (12)N PET imaging potentially provides equal to superior proton range information compared to prompt gamma imaging with an optimized knife-edge slit camera. The practical implementation of (12)N PET imaging is discussed.

  1. Short-lived positron emitters in beam-on PET imaging during proton therapy

    NASA Astrophysics Data System (ADS)

    Dendooven, P.; Buitenhuis, H. J. T.; Diblen, F.; Heeres, P. N.; Biegun, A. K.; Fiedler, F.; van Goethem, M.-J.; van der Graaf, E. R.; Brandenburg, S.

    2015-12-01

    The only method for in vivo dose delivery verification in proton beam radiotherapy in clinical use today is positron emission tomography (PET) of the positron emitters produced in the patient during irradiation. PET imaging while the beam is on (so called beam-on PET) is an attractive option, providing the largest number of counts, the least biological washout and the fastest feedback. In this implementation, all nuclides, independent of their half-life, will contribute. As a first step towards assessing the relevance of short-lived nuclides (half-life shorter than that of 10C, T1/2  =  19 s) for in vivo dose delivery verification using beam-on PET, we measured their production in the stopping of 55 MeV protons in water, carbon, phosphorus and calcium The most copiously produced short-lived nuclides and their production rates relative to the relevant long-lived nuclides are: 12N (T1/2  =  11 ms) on carbon (9% of 11C), 29P (T1/2  =  4.1 s) on phosphorus (20% of 30P) and 38mK (T1/2  =  0.92 s) on calcium (113% of 38gK). No short-lived nuclides are produced on oxygen. The number of decays integrated from the start of an irradiation as a function of time during the irradiation of PMMA and 4 tissue materials has been determined. For (carbon-rich) adipose tissue, 12N dominates up to 70 s. On bone tissue, 12N dominates over 15O during the first 8-15 s (depending on carbon-to-oxygen ratio). The short-lived nuclides created on phosphorus and calcium provide 2.5 times more beam-on PET counts than the long-lived ones produced on these elements during a 70 s irradiation. From the estimated number of 12N PET counts, we conclude that, for any tissue, 12N PET imaging potentially provides equal to superior proton range information compared to prompt gamma imaging with an optimized knife-edge slit camera. The practical implementation of 12N PET imaging is discussed.

  2. Iodine-124 as a label for pharmacological PET imaging.

    PubMed

    Belov, Vasily V; Bonab, Ali A; Fischman, Alan J; Heartlein, Michael; Calias, Pericles; Papisov, Mikhail I

    2011-06-06

    With the growing number of biotechnology products and drug delivery systems entering preclinical and clinical studies, pharmacological imaging studies with PET play an increasingly significant role. Such studies often require investigation of slow and complex pharmacokinetics (PK). This suggests labeling of the drug candidate with radionuclides that have long physical half-lives. Among the currently available PET positron emitters, ¹²⁴I has the longest physical half-life (4.2 days). This, combined with the well-investigated behavior of iodine in vivo, makes ¹²⁴I very attractive for pharmacological studies. However, the high energy of the positrons emitted by ¹²⁴I and the presence of single photons in the ¹²⁴I emission can potentially introduce limitations in the quantitative analysis of the images. The objective of this research was to determine whether the use of ¹²⁴I as a PET label provides data quality suitable for PK studies. The study was carried out using MicroPET P4 scanner (Siemens/Concorde Microsystems). Spatial resolution, count-rate performance, sensitivity and scatter fraction were measured using a line source and a cylindrical phantom. Model animal studies in rats and cynomolgus monkeys were carried out using human recombinant proteins. The proteins were labeled with ¹²⁴I, up to 185 MBq/mg. The transaxial and axial spatial resolutions in the center of the camera were satisfactory and higher for OSEM3D/MAP than FORE-2DFBP (FWHM 2.52 vs 3.31 mm, and 3.10 vs 3.69 mm). Linearity of the true coincidence count-rate was observed up to 44 MBq. Animal studies demonstrated excellent delineation and resolution of even very small organs. At optimal doses, 2-10 MBq per animal for rodents and 4-10 MBq per kg of body weight for larger animals, the quality of numerical data was appropriate for PK analysis in all experimental timeframes from minutes (dynamic studies) to 10 days. Overall, the data suggest that ¹²⁴I is an excellent label for

  3. Investigational study of iodine-124 with a positron camera

    SciTech Connect

    Lambrecht, R.M.; Woodhouse, N.; Phillips, R.; Wolczak, D.; Qureshi, A.; Reyes, E.D.; Graser, C.; Al-Yanbawi, S.; Al-Rabiah, A.; Meyer, W.

    1988-01-01

    A case is presented where I-124 produced by a clinical cyclotron was used with a positron emission tomography camera for clinical usage. This represents the first report of the utilization of this modality with this radionuclide. We feel the increased spatial resolution of PET should be of value in looking at thyroid disease.

  4. Optimising camera traps for monitoring small mammals.

    PubMed

    Glen, Alistair S; Cockburn, Stuart; Nichols, Margaret; Ekanayake, Jagath; Warburton, Bruce

    2013-01-01

    Practical techniques are required to monitor invasive animals, which are often cryptic and occur at low density. Camera traps have potential for this purpose, but may have problems detecting and identifying small species. A further challenge is how to standardise the size of each camera's field of view so capture rates are comparable between different places and times. We investigated the optimal specifications for a low-cost camera trap for small mammals. The factors tested were 1) trigger speed, 2) passive infrared vs. microwave sensor, 3) white vs. infrared flash, and 4) still photographs vs. video. We also tested a new approach to standardise each camera's field of view. We compared the success rates of four camera trap designs in detecting and taking recognisable photographs of captive stoats (Mustelaerminea), feral cats (Felis catus) and hedgehogs (Erinaceuseuropaeus). Trigger speeds of 0.2-2.1 s captured photographs of all three target species unless the animal was running at high speed. The camera with a microwave sensor was prone to false triggers, and often failed to trigger when an animal moved in front of it. A white flash produced photographs that were more readily identified to species than those obtained under infrared light. However, a white flash may be more likely to frighten target animals, potentially affecting detection probabilities. Video footage achieved similar success rates to still cameras but required more processing time and computer memory. Placing two camera traps side by side achieved a higher success rate than using a single camera. Camera traps show considerable promise for monitoring invasive mammal control operations. Further research should address how best to standardise the size of each camera's field of view, maximise the probability that an animal encountering a camera trap will be detected, and eliminate visible or audible cues emitted by camera traps.

  5. Trajectory association across multiple airborne cameras.

    PubMed

    Sheikh, Yaser Ajmal; Shah, Mubarak

    2008-02-01

    A camera mounted on an aerial vehicle provides an excellent means for monitoring large areas of a scene. Utilizing several such cameras on different aerial vehicles allows further flexibility, in terms of increased visual scope and in the pursuit of multiple targets. In this paper, we address the problem of associating objects across multiple airborne cameras. Since the cameras are moving and often widely separated, direct appearance-based or proximity-based constraints cannot be used. Instead, we exploit geometric constraints on the relationship between the motion of each object across cameras, to test multiple association hypotheses, without assuming any prior calibration information. Given our scene model, we propose a likelihood function for evaluating a hypothesized association between observations in multiple cameras that is geometrically motivated. Since multiple cameras exist, ensuring coherency in association is an essential requirement, e.g. that transitive closure is maintained between more than two cameras. To ensure such coherency we pose the problem of maximizing the likelihood function as a k-dimensional matching and use an approximation to find the optimal assignment of association. Using the proposed error function, canonical trajectories of each object and optimal estimates of inter-camera transformations (in a maximum likelihood sense) are computed. Finally, we show that as a result of associating objects across the cameras, a concurrent visualization of multiple aerial video streams is possible and that, under special conditions, trajectories interrupted due to occlusion or missing detections can be repaired. Results are shown on a number of real and controlled scenarios with multiple objects observed by multiple cameras, validating our qualitative models, and through simulation quantitative performance is also reported.

  6. Constrained space camera assembly

    DOEpatents

    Heckendorn, Frank M.; Anderson, Erin K.; Robinson, Casandra W.; Haynes, Harriet B.

    1999-01-01

    A constrained space camera assembly which is intended to be lowered through a hole into a tank, a borehole or another cavity. The assembly includes a generally cylindrical chamber comprising a head and a body and a wiring-carrying conduit extending from the chamber. Means are included in the chamber for rotating the body about the head without breaking an airtight seal formed therebetween. The assembly may be pressurized and accompanied with a pressure sensing means for sensing if a breach has occurred in the assembly. In one embodiment, two cameras, separated from their respective lenses, are installed on a mounting apparatus disposed in the chamber. The mounting apparatus includes means allowing both longitudinal and lateral movement of the cameras. Moving the cameras longitudinally focuses the cameras, and moving the cameras laterally away from one another effectively converges the cameras so that close objects can be viewed. The assembly further includes means for moving lenses of different magnification forward of the cameras.

  7. Novel fundus camera design

    NASA Astrophysics Data System (ADS)

    Dehoog, Edward A.

    A fundus camera a complex optical system that makes use of the principle of reflex free indirect ophthalmoscopy to image the retina. Despite being in existence as early as 1900's, little has changed in the design of a fundus camera and there is minimal information about the design principles utilized. Parameters and specifications involved in the design of fundus camera are determined and their affect on system performance are discussed. Fundus cameras incorporating different design methods are modeled and a performance evaluation based on design parameters is used to determine the effectiveness of each design strategy. By determining the design principles involved in the fundus camera, new cameras can be designed to include specific imaging modalities such as optical coherence tomography, imaging spectroscopy and imaging polarimetry to gather additional information about properties and structure of the retina. Design principles utilized to incorporate such modalities into fundus camera systems are discussed. Design, implementation and testing of a snapshot polarimeter fundus camera are demonstrated.

  8. Making Ceramic Cameras

    ERIC Educational Resources Information Center

    Squibb, Matt

    2009-01-01

    This article describes how to make a clay camera. This idea of creating functional cameras from clay allows students to experience ceramics, photography, and painting all in one unit. (Contains 1 resource and 3 online resources.)

  9. Vacuum Camera Cooler

    NASA Technical Reports Server (NTRS)

    Laugen, Geoffrey A.

    2011-01-01

    Acquiring cheap, moving video was impossible in a vacuum environment, due to camera overheating. This overheating is brought on by the lack of cooling media in vacuum. A water-jacketed camera cooler enclosure machined and assembled from copper plate and tube has been developed. The camera cooler (see figure) is cup-shaped and cooled by circulating water or nitrogen gas through copper tubing. The camera, a store-bought "spy type," is not designed to work in a vacuum. With some modifications the unit can be thermally connected when mounted in the cup portion of the camera cooler. The thermal conductivity is provided by copper tape between parts of the camera and the cooled enclosure. During initial testing of the demonstration unit, the camera cooler kept the CPU (central processing unit) of this video camera at operating temperature. This development allowed video recording of an in-progress test, within a vacuum environment.

  10. PET Imaging of Angiogenesis

    PubMed Central

    Niu, Gang; Chen, Xiaoyuan

    2009-01-01

    Synopsis Angiogenesis is a highly-controlled process that is dependent on the intricate balance of both promoting and inhibiting factors, involved in various physiological and pathological processes. A comprehensive understanding of the molecular mechanisms that regulate angiogenesis has resulted in the design of new and more effective therapeutic strategies. Due to insufficient sensitivity to detect therapeutic effects by using standard clinical endpoints or by looking for physiological improvement, a multitude of imaging techniques have been developed to assess tissue vasculature on the structural, functional and molecular level. Imaging is expected to provide a novel approach to noninvasively monitor angiogenesis, to optimize the dose of new antiangiogenic agents and to assess the efficacy of therapies directed at modulation of the angiogenic process. All these methods have been successfully used preclinically and will hopefully aid in antiangiogenic drug development in animal studies. In this review article, the application of PET in angiogenesis imaging at both functional and molecular level will be discussed. For PET imaging of angiogenesis related molecular markers, we emphasize integrin αvβ3, VEGF/VEGFR, and MMPs. PMID:20046926

  11. MO-AB-206-02: Testing Gamma Cameras Based On TG177 WG Report.

    PubMed

    Halama, J

    2016-06-01

    This education session will cover the physics and operation principles of gamma cameras and PET scanners. The first talk will focus on PET imaging. An overview of the principles of PET imaging will be provided, including positron decay physics, and the transition from 2D to 3D imaging. More recent advances in hardware and software will be discussed, such as time-of-flight imaging, and improvements in reconstruction algorithms that provide for options such as depth-of-interaction corrections. Quantitative applications of PET will be discussed, as well as the requirements for doing accurate quantitation. Relevant performance tests will also be described.

  12. Those Nifty Digital Cameras!

    ERIC Educational Resources Information Center

    Ekhaml, Leticia

    1996-01-01

    Describes digital photography--an electronic imaging technology that merges computer capabilities with traditional photography--and its uses in education. Discusses how a filmless camera works, types of filmless cameras, advantages and disadvantages, and educational applications of the consumer digital cameras. (AEF)

  13. Digital Pinhole Camera

    ERIC Educational Resources Information Center

    Lancor, Rachael; Lancor, Brian

    2014-01-01

    In this article we describe how the classic pinhole camera demonstration can be adapted for use with digital cameras. Students can easily explore the effects of the size of the pinhole and its distance from the sensor on exposure time, magnification, and image quality. Instructions for constructing a digital pinhole camera and our method for…

  14. Leptospirosis and Pets

    MedlinePlus

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

  15. 2. VAL CAMERA CAR, VIEW OF CAMERA CAR AND TRACK ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. VAL CAMERA CAR, VIEW OF CAMERA CAR AND TRACK WITH CAMERA STATION ABOVE LOOKING WEST TAKEN FROM RESERVOIR. - Variable Angle Launcher Complex, Camera Car & Track, CA State Highway 39 at Morris Reservior, Azusa, Los Angeles County, CA

  16. 7. VAL CAMERA CAR, DETAIL OF 'FLARE' OR TRAJECTORY CAMERA ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. VAL CAMERA CAR, DETAIL OF 'FLARE' OR TRAJECTORY CAMERA INSIDE CAMERA CAR. - Variable Angle Launcher Complex, Camera Car & Track, CA State Highway 39 at Morris Reservior, Azusa, Los Angeles County, CA

  17. 6. VAL CAMERA CAR, DETAIL OF COMMUNICATION EQUIPMENT INSIDE CAMERA ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. VAL CAMERA CAR, DETAIL OF COMMUNICATION EQUIPMENT INSIDE CAMERA CAR WITH CAMERA MOUNT IN FOREGROUND. - Variable Angle Launcher Complex, Camera Car & Track, CA State Highway 39 at Morris Reservior, Azusa, Los Angeles County, CA

  18. Tower Camera Handbook

    SciTech Connect

    Moudry, D

    2005-01-01

    The tower camera in Barrow provides hourly images of ground surrounding the tower. These images may be used to determine fractional snow cover as winter arrives, for comparison with the albedo that can be calculated from downward-looking radiometers, as well as some indication of present weather. Similarly, during spring time, the camera images show the changes in the ground albedo as the snow melts. The tower images are saved in hourly intervals. In addition, two other cameras, the skydeck camera in Barrow and the piling camera in Atqasuk, show the current conditions at those sites.

  19. AAPM Task Group 108: PET and PET/CT shielding requirements.

    PubMed

    Madsen, Mark T; Anderson, Jon A; Halama, James R; Kleck, Jeff; Simpkin, Douglas J; Votaw, John R; Wendt, Richard E; Williams, Lawrence E; Yester, Michael V

    2006-01-01

    The shielding of positron emission tomography (PET) and PET/CT (computed tomography) facilities presents special challenges. The 0.511 MeV annihilation photons associated with positron decay are much higher energy than other diagnostic radiations. As a result, barrier shielding may be required in floors and ceilings as well as adjacent walls. Since the patient becomes the radioactive source after the radiopharmaceutical has been administered, one has to consider the entire time that the subject remains in the clinic. In this report we present methods for estimating the shielding requirements for PET and PET/CT facilities. Information about the physical properties of the most commonly used clinical PET radionuclides is summarized, although the report primarily refers to fluorine-18. Typical PET imaging protocols are reviewed and exposure rates from patients are estimated including self-attenuation by body tissues and physical decay of the radionuclide. Examples of barrier calculations are presented for controlled and noncontrolled areas. Shielding for adjacent rooms with scintillation cameras is also discussed. Tables and graphs of estimated transmission factors for lead, steel, and concrete at 0.511 MeV are also included. Meeting the regulatory limits for uncontrolled areas can be an expensive proposition. Careful planning with the equipment vendor, facility architect, and a qualified medical physicist is necessary to produce a cost effective design while maintaining radiation safety standards.

  20. Miniaturized fundus camera

    NASA Astrophysics Data System (ADS)

    Gliss, Christine; Parel, Jean-Marie A.; Flynn, John T.; Pratisto, Hans S.; Niederer, Peter F.

    2003-07-01

    We present a miniaturized version of a fundus camera. The camera is designed for the use in screening for retinopathy of prematurity (ROP). There, but also in other applications a small, light weight, digital camera system can be extremely useful. We present a small wide angle digital camera system. The handpiece is significantly smaller and lighter then in all other systems. The electronics is truly portable fitting in a standard boardcase. The camera is designed to be offered at a compatible price. Data from tests on young rabbits' eyes is presented. The development of the camera system is part of a telemedicine project screening for ROP. Telemedical applications are a perfect application for this camera system using both advantages: the portability as well as the digital image.

  1. Optimization of dynamic measurement of receptor kinetics by wavelet denoising.

    PubMed

    Alpert, Nathaniel M; Reilhac, Anthonin; Chio, Tat C; Selesnick, Ivan

    2006-04-01

    The most important technical limitation affecting dynamic measurements with PET is low signal-to-noise ratio (SNR). Several reports have suggested that wavelet processing of receptor kinetic data in the human brain can improve the SNR of parametric images of binding potential (BP). However, it is difficult to fully assess these reports because objective standards have not been developed to measure the tradeoff between accuracy (e.g. degradation of resolution) and precision. This paper employs a realistic simulation method that includes all major elements affecting image formation. The simulation was used to derive an ensemble of dynamic PET ligand (11C-raclopride) experiments that was subjected to wavelet processing. A method for optimizing wavelet denoising is presented and used to analyze the simulated experiments. Using optimized wavelet denoising, SNR of the four-dimensional PET data increased by about a factor of two and SNR of three-dimensional BP maps increased by about a factor of 1.5. Analysis of the difference between the processed and unprocessed means for the 4D concentration data showed that more than 80% of voxels in the ensemble mean of the wavelet processed data deviated by less than 3%. These results show that a 1.5x increase in SNR can be achieved with little degradation of resolution. This corresponds to injecting about twice the radioactivity, a maneuver that is not possible in human studies without saturating the PET camera and/or exposing the subject to more than permitted radioactivity.

  2. PET imaging of adoptive progenitor cell therapies.

    SciTech Connect

    Gelovani, Juri G.

    2008-05-13

    stem cell imaging is proposed to circumvent the major limitation of in vitro radiolabeling – the eventual radiolabel decay. Stable transduction of stem cells in vitro would allow for the selection of high quality stem cells with optimal functional parameters of the transduced reporter systems. The use of a long-lived radioisotope 124I to label a highly specific reporter gene probe will allow for ex vivo labeling of stem cells and their imaging immediately after injection and during the following next week. The use of short-lived radioisotopes (i.e., 18F) to label highly specific reporter gene probes will allow repetitive PET imaging for the assessment of to stem cell migration, targeting, differentiation, and long-term viability of stem cell-derived tissues. Qualifications of the research team and resources. An established research team of experts in various disciplines has been assembled at MD Anderson Cancer Center (MDACC) over the past two years including the PI, senior co-investigators and collaborators. The participants of this team are recognized internationally to be among the leaders in their corresponding fields of research and clinical medicine. The resources at MDACC are exceptionally well developed and have been recently reinforced by the installation of a microPET and microSPECT/CT cameras, and a 7T MRI system for high resolution animal imaging; and by integrating a synthetic chemistry core for the development and production of precursors for radiolabeling.

  3. [Positron-emission tomography (PET)--basic considerations].

    PubMed

    von Schulthess, G K; Westera, G; Schubiger, P A

    1993-08-24

    A PET installation is a technically complex system composed essentially of two parts. The first consists in isotope production and synthesis of labeled biochemical compounds, the second in measuring the distribution of radioactivity in the body with the PET camera and the generation of image data. The specific advantage of PET lies on one hand in the use of positron emitters that are isotopes of ubiquitous elements in biologic matter, i.e. exact analogs of biomolecules can be produced and utilized and on the other hand quantification is possible. (= enable quantitative...?) Theoretically there are no limits for the synthesis of radioactive compounds and the method therefore provides unlimited test designs. The short half-life of the employed isotopes is advantageous for radioprotection reasons but the production of labeled compounds necessitates a cyclotron accelerator and a special laboratory for the handling of radioactive compounds rendering the production of the test substances relatively expensive. Measurements take place in a PET camera with a large number of coincidence detectors. The best available cameras have a spatial resolution of 5 mm in all three axes with an axial window of about 15 cm diameter. Evaluation of PET images is done in a qualitative way by superposition on anatomic images (CT, MRI) by image fusion. Quantitative determinations require elaborate computer modeling.

  4. Reduced grey matter metabolism due to white matter edema allows optimal assessment of brain tumors on 18F-FDG-PET.

    PubMed

    Pourdehnad, Michael; Basu, Sandip; Duarte, Paulo; Okpaku, Aubrey S; Saboury, Babak; Hustinx, Roland; Alavi, Abass

    2011-01-01

    The main aim of this research was to demonstrate that the cortical and subcortical grey matter hypometabolism as revealed by fluorine-18 fluorodesoxyglucose-positron emission tomography ((18)F-FDG-PET) imaging in brain tumors is related to associated edema as demonstrated by magnetic resonance imaging (MRI). This in turn enhances the ability to assess disease activity in the tumor and the degree of loss of cerebral function in the adjacent and distant structures. We evaluated brain T1 and T2 weighted MRI and (18)F-FDG-PET scans of 29 patients (19 adult, 10 pediatric) with history of brain tumor. Tumor histology types included 21 gliomas, 1 melanoma, 1 primitive neuroectodermal tumor, 3 medulloblastomas and 3 ependymomas. The majority of scans were performed within the same week (94% <1 month. The extent of hypo and hypermetabolism was assessed on the (18)F-FDG-PET scans. A template of 12 regions of interest (ROI) was applied and the laterality indices of the regional counts (signal intensity) were computed. Extent of edema, enhancement, and anatomical change were assessed on the MRI scans. Extent of edema in the same ROI was evaluated by a 6-point semiquantitative scale and laterality indices were generated. Metabolic activity of the grey matter was correlated with the extent of edema using these indices. In all cases where edema was present, significant hypometabolism was observed in the adjacent structures. Overall, there was a strong correlation between the extent of edema and severity of hypometabolism (r=0.92, P=0.01). This was true regardless of the location of edema, whether there was history of radiation treatment (r=0.91, P=0.03), or not (r=0.97, P=0.17). In conclusion, edema independent of underlying variables appeared to contribute significantly to cortical and sub-cortical grey matter hypometabolism observed in patients with brain tumors. This would indicate that brain tumors can be successfully assessed by (18)F-FDG-PET and therefore the efforts for

  5. Depth Estimation Using a Sliding Camera.

    PubMed

    Ge, Kailin; Hu, Han; Feng, Jianjiang; Zhou, Jie

    2016-02-01

    Image-based 3D reconstruction technology is widely used in different fields. The conventional algorithms are mainly based on stereo matching between two or more fixed cameras, and high accuracy can only be achieved using a large camera array, which is very expensive and inconvenient in many applications. Another popular choice is utilizing structure-from-motion methods for arbitrarily placed camera(s). However, due to too many degrees of freedom, its computational cost is heavy and its accuracy is rather limited. In this paper, we propose a novel depth estimation algorithm using a sliding camera system. By analyzing the geometric properties of the camera system, we design a camera pose initialization algorithm that can work satisfyingly with only a small number of feature points and is robust to noise. For pixels corresponding to different depths, an adaptive iterative algorithm is proposed to choose optimal frames for stereo matching, which can take advantage of continuously pose-changing imaging and save the time consumption amazingly too. The proposed algorithm can also be easily extended to handle less constrained situations (such as using a camera mounted on a moving robot or vehicle). Experimental results on both synthetic and real-world data have illustrated the effectiveness of the proposed algorithm.

  6. Microchannel plate streak camera

    DOEpatents

    Wang, Ching L.

    1989-01-01

    An improved streak camera in which a microchannel plate electron multiplier is used in place of or in combination with the photocathode used in prior streak cameras. The improved streak camera is far more sensitive to photons (UV to gamma-rays) than the conventional x-ray streak camera which uses a photocathode. The improved streak camera offers gamma-ray detection with high temporal resolution. It also offers low-energy x-ray detection without attenuation inside the cathode. Using the microchannel plate in the improved camera has resulted in a time resolution of about 150 ps, and has provided a sensitivity sufficient for 1000 KeV x-rays.

  7. GRACE star camera noise

    NASA Astrophysics Data System (ADS)

    Harvey, Nate

    2016-08-01

    Extending results from previous work by Bandikova et al. (2012) and Inacio et al. (2015), this paper analyzes Gravity Recovery and Climate Experiment (GRACE) star camera attitude measurement noise by processing inter-camera quaternions from 2003 to 2015. We describe a correction to star camera data, which will eliminate a several-arcsec twice-per-rev error with daily modulation, currently visible in the auto-covariance function of the inter-camera quaternion, from future GRACE Level-1B product releases. We also present evidence supporting the argument that thermal conditions/settings affect long-term inter-camera attitude biases by at least tens-of-arcsecs, and that several-to-tens-of-arcsecs per-rev star camera errors depend largely on field-of-view.

  8. Microchannel plate streak camera

    DOEpatents

    Wang, C.L.

    1984-09-28

    An improved streak camera in which a microchannel plate electron multiplier is used in place of or in combination with the photocathode used in prior streak cameras. The improved streak camera is far more sensitive to photons (uv to gamma-rays) than the conventional x-ray streak camera which uses a photocathode. The improved streak camera offers gamma-ray detection with high temporal resolution. It also offers low-energy x-ray detection without attenuation inside the cathode. Using the microchannel plate in the improved camera has resulted in a time resolution of about 150 ps, and has provided a sensitivity sufficient for 1000 keV x-rays.

  9. Microchannel plate streak camera

    DOEpatents

    Wang, C.L.

    1989-03-21

    An improved streak camera in which a microchannel plate electron multiplier is used in place of or in combination with the photocathode used in prior streak cameras is disclosed. The improved streak camera is far more sensitive to photons (UV to gamma-rays) than the conventional x-ray streak camera which uses a photocathode. The improved streak camera offers gamma-ray detection with high temporal resolution. It also offers low-energy x-ray detection without attenuation inside the cathode. Using the microchannel plate in the improved camera has resulted in a time resolution of about 150 ps, and has provided a sensitivity sufficient for 1,000 KeV x-rays. 3 figs.

  10. Review: comparison of PET rubidium-82 with conventional SPECT myocardial perfusion imaging.

    PubMed

    Ghotbi, Adam A; Kjaer, Andreas; Hasbak, Philip

    2014-05-01

    Nuclear cardiology has for many years been focused on gamma camera technology. With ever improving cameras and software applications, this modality has developed into an important assessment tool for ischaemic heart disease. However, the development of new perfusion tracers has been scarce. While cardiac positron emission tomography (PET) so far largely has been limited to centres with on-site cyclotron, recent developments with generator produced perfusion tracers such as rubidium-82, as well as an increasing number of PET scanners installed, may enable a larger patient flow that may supersede that of gamma camera myocardial perfusion imaging.

  11. Analytical multicollimator camera calibration

    USGS Publications Warehouse

    Tayman, W.P.

    1978-01-01

    Calibration with the U.S. Geological survey multicollimator determines the calibrated focal length, the point of symmetry, the radial distortion referred to the point of symmetry, and the asymmetric characteristiecs of the camera lens. For this project, two cameras were calibrated, a Zeiss RMK A 15/23 and a Wild RC 8. Four test exposures were made with each camera. Results are tabulated for each exposure and averaged for each set. Copies of the standard USGS calibration reports are included. ?? 1978.

  12. Streak camera meeting summary

    SciTech Connect

    Dolan, Daniel H.; Bliss, David E.

    2014-09-01

    Streak cameras are important for high-speed data acquisition in single event experiments, where the total recorded information (I) is shared between the number of measurements (M) and the number of samples (S). Topics of this meeting included: streak camera use at the national laboratories; current streak camera production; new tube developments and alternative technologies; and future planning. Each topic is summarized in the following sections.

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

    DTIC Science & Technology

    2012-07-01

    Compton camera in nuclear medical imaging. IEEE Trans Nucl Sci 2002; 49:812–16. [15] Linhart V, Burdette D, Chessi E, et al. Spectroscopy study of...applications can be recognized in both emission modalities, SPECT and PET. Compton camera is a subspecies of SPECT, where a silicon based scatter as a MR...Introducing a Compton camera also relaxes requirements of the radiotracers used, extending the range of conceivable photon energies beyond 140.5 keV of the

  14. Digital Electronic Still Camera

    NASA Technical Reports Server (NTRS)

    Holland, Samuel D.; Yeates, Herbert D.

    1993-01-01

    Digital electronic still camera part of electronic recording, processing, tansmitting, and displaying system. Removable hard-disk drive in camera serves as digital electronic equivalent of photographic film. Images viewed, analyzed, or transmitted quickly. Camera takes images of nearly photographic quality and stores them in digital form. Portable, hand-held, battery-powered unit designed for scientific use. Camera used in conjunction with playback unit also serving as transmitting unit if images sent to remote station. Remote station equipped to store, process, and display images. Digital image data encoded with error-correcting code at playback/transmitting unit for error-free transmission to remote station.

  15. Digital camera simulation.

    PubMed

    Farrell, Joyce E; Catrysse, Peter B; Wandell, Brian A

    2012-02-01

    We describe a simulation of the complete image processing pipeline of a digital camera, beginning with a radiometric description of the scene captured by the camera and ending with a radiometric description of the image rendered on a display. We show that there is a good correspondence between measured and simulated sensor performance. Through the use of simulation, we can quantify the effects of individual digital camera components on system performance and image quality. This computational approach can be helpful for both camera design and image quality assessment.

  16. Pet-Related Infections.

    PubMed

    Day, Michael J

    2016-11-15

    Physicians and veterinarians have many opportunities to partner in promoting the well-being of people and their pets, especially by addressing zoonotic diseases that may be transmitted between a pet and a human family member. Common cutaneous pet-acquired zoonoses are dermatophytosis (ringworm) and sarcoptic mange (scabies), which are both readily treated. Toxoplasmosis can be acquired from exposure to cat feces, but appropriate hygienic measures can minimize the risk to pregnant women. Persons who work with animals are at increased risk of acquiring bartonellosis (e.g., cat-scratch disease); control of cat fleas is essential to minimize the risk of these infections. People and their pets share a range of tick-borne diseases, and exposure risk can be minimized with use of tick repellent, prompt tick removal, and appropriate tick control measures for pets. Pets such as reptiles, amphibians, and backyard poultry pose a risk of transmitting Salmonella species and are becoming more popular. Personal hygiene after interacting with these pets is crucial to prevent Salmonella infections. Leptospirosis is more often acquired from wildlife than infected dogs, but at-risk dogs can be protected with vaccination. The clinical history in the primary care office should routinely include questions about pets and occupational or other exposure to pet animals. Control and prevention of zoonoses are best achieved by enhancing communication between physicians and veterinarians to ensure patients know the risks of and how to prevent zoonoses in themselves, their pets, and other people.

  17. CCD Luminescence Camera

    NASA Technical Reports Server (NTRS)

    Janesick, James R.; Elliott, Tom

    1987-01-01

    New diagnostic tool used to understand performance and failures of microelectronic devices. Microscope integrated to low-noise charge-coupled-device (CCD) camera to produce new instrument for analyzing performance and failures of microelectronics devices that emit infrared light during operation. CCD camera also used to indentify very clearly parts that have failed where luminescence typically found.

  18. Constrained space camera assembly

    DOEpatents

    Heckendorn, F.M.; Anderson, E.K.; Robinson, C.W.; Haynes, H.B.

    1999-05-11

    A constrained space camera assembly which is intended to be lowered through a hole into a tank, a borehole or another cavity is disclosed. The assembly includes a generally cylindrical chamber comprising a head and a body and a wiring-carrying conduit extending from the chamber. Means are included in the chamber for rotating the body about the head without breaking an airtight seal formed therebetween. The assembly may be pressurized and accompanied with a pressure sensing means for sensing if a breach has occurred in the assembly. In one embodiment, two cameras, separated from their respective lenses, are installed on a mounting apparatus disposed in the chamber. The mounting apparatus includes means allowing both longitudinal and lateral movement of the cameras. Moving the cameras longitudinally focuses the cameras, and moving the cameras laterally away from one another effectively converges the cameras so that close objects can be viewed. The assembly further includes means for moving lenses of different magnification forward of the cameras. 17 figs.

  19. Compact Solar Camera.

    ERIC Educational Resources Information Center

    Juergens, Albert

    1980-01-01

    Describes a compact solar camera built as a one-semester student project. This camera is used for taking pictures of the sun and moon and for direct observation of the image of the sun on a screen. (Author/HM)

  20. The DSLR Camera

    NASA Astrophysics Data System (ADS)

    Berkó, Ernő; Argyle, R. W.

    Cameras have developed significantly in the past decade; in particular, digital Single-Lens Reflex Cameras (DSLR) have appeared. As a consequence we can buy cameras of higher and higher pixel number, and mass production has resulted in the great reduction of prices. CMOS sensors used for imaging are increasingly sensitive, and the electronics in the cameras allows images to be taken with much less noise. The software background is developing in a similar way—intelligent programs are created for after-processing and other supplementary works. Nowadays we can find a digital camera in almost every household, most of these cameras are DSLR ones. These can be used very well for astronomical imaging, which is nicely demonstrated by the amount and quality of the spectacular astrophotos appearing in different publications. These examples also show how much post-processing software contributes to the rise in the standard of the pictures. To sum up, the DSLR camera serves as a cheap alternative for the CCD camera, with somewhat weaker technical characteristics. In the following, I will introduce how we can measure the main parameters (position angle and separation) of double stars, based on the methods, software and equipment I use. Others can easily apply these for their own circumstances.

  1. Camera Operator and Videographer

    ERIC Educational Resources Information Center

    Moore, Pam

    2007-01-01

    Television, video, and motion picture camera operators produce images that tell a story, inform or entertain an audience, or record an event. They use various cameras to shoot a wide range of material, including television series, news and sporting events, music videos, motion pictures, documentaries, and training sessions. Those who film or…

  2. Dry imaging cameras.

    PubMed

    Indrajit, Ik; Alam, Aftab; Sahni, Hirdesh; Bhatia, Mukul; Sahu, Samaresh

    2011-04-01

    Dry imaging cameras are important hard copy devices in radiology. Using dry imaging camera, multiformat images of digital modalities in radiology are created from a sealed unit of unexposed films. The functioning of a modern dry camera, involves a blend of concurrent processes, in areas of diverse sciences like computers, mechanics, thermal, optics, electricity and radiography. Broadly, hard copy devices are classified as laser and non laser based technology. When compared with the working knowledge and technical awareness of different modalities in radiology, the understanding of a dry imaging camera is often superficial and neglected. To fill this void, this article outlines the key features of a modern dry camera and its important issues that impact radiology workflow.

  3. Sensory analysis of pet foods.

    PubMed

    Koppel, Kadri

    2014-08-01

    Pet food palatability depends first and foremost on the pet and is related to the pet food sensory properties such as aroma, texture and flavor. Sensory analysis of pet foods may be conducted by humans via descriptive or hedonic analysis, pets via acceptance or preference tests, and through a number of instrumental analysis methods. Sensory analysis of pet foods provides additional information on reasons behind palatable and unpalatable foods as pets lack linguistic capabilities. Furthermore, sensory analysis may be combined with other types of information such as personality and environment factors to increase understanding of acceptable pet foods. Most pet food flavor research is proprietary and, thus, there are a limited number of publications available. Funding opportunities for pet food studies would increase research and publications and this would help raise public awareness of pet food related issues. This mini-review addresses current pet food sensory analysis literature and discusses future challenges and possibilities.

  4. Action selection for single-camera SLAM.

    PubMed

    Vidal-Calleja, Teresa A; Sanfeliu, Alberto; Andrade-Cetto, Juan

    2010-12-01

    A method for evaluating, at video rate, the quality of actions for a single camera while mapping unknown indoor environments is presented. The strategy maximizes mutual information between measurements and states to help the camera avoid making ill-conditioned measurements that are appropriate to lack of depth in monocular vision systems. Our system prompts a user with the appropriate motion commands during 6-DOF visual simultaneous localization and mapping with a handheld camera. Additionally, the system has been ported to a mobile robotic platform, thus closing the control-estimation loop. To show the viability of the approach, simulations and experiments are presented for the unconstrained motion of a handheld camera and for the motion of a mobile robot with nonholonomic constraints. When combined with a path planner, the technique safely drives to a marked goal while, at the same time, producing an optimal estimated map.

  5. 7. VAL CAMERA STATION, INTERIOR VIEW OF CAMERA MOUNT, COMMUNICATION ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. VAL CAMERA STATION, INTERIOR VIEW OF CAMERA MOUNT, COMMUNICATION EQUIPMENT AND STORAGE CABINET. - Variable Angle Launcher Complex, Camera Stations, CA State Highway 39 at Morris Reservior, Azusa, Los Angeles County, CA

  6. 3. VAL CAMERA CAR, VIEW OF CAMERA CAR AND TRACK ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. VAL CAMERA CAR, VIEW OF CAMERA CAR AND TRACK WITH THE VAL TO THE RIGHT, LOOKING NORTHEAST. - Variable Angle Launcher Complex, Camera Car & Track, CA State Highway 39 at Morris Reservior, Azusa, Los Angeles County, CA

  7. Imaging and dosimetric errors in 4D PET/CT-guided radiotherapy from patient-specific respiratory patterns: a dynamic motion phantom end-to-end study

    NASA Astrophysics Data System (ADS)

    Bowen, S. R.; Nyflot, M. J.; Herrmann, C.; Groh, C. M.; Meyer, J.; Wollenweber, S. D.; Stearns, C. W.; Kinahan, P. E.; Sandison, G. A.

    2015-05-01

    Effective positron emission tomography / computed tomography (PET/CT) guidance in radiotherapy of lung cancer requires estimation and mitigation of errors due to respiratory motion. An end-to-end workflow was developed to measure patient-specific motion-induced uncertainties in imaging, treatment planning, and radiation delivery with respiratory motion phantoms and dosimeters. A custom torso phantom with inserts mimicking normal lung tissue and lung lesion was filled with [18F]FDG. The lung lesion insert was driven by six different patient-specific respiratory patterns or kept stationary. PET/CT images were acquired under motionless ground truth, tidal breathing motion-averaged (3D), and respiratory phase-correlated (4D) conditions. Target volumes were estimated by standardized uptake value (SUV) thresholds that accurately defined the ground-truth lesion volume. Non-uniform dose-painting plans using volumetrically modulated arc therapy were optimized for fixed normal lung and spinal cord objectives and variable PET-based target objectives. Resulting plans were delivered to a cylindrical diode array at rest, in motion on a platform driven by the same respiratory patterns (3D), or motion-compensated by a robotic couch with an infrared camera tracking system (4D). Errors were estimated relative to the static ground truth condition for mean target-to-background (T/Bmean) ratios, target volumes, planned equivalent uniform target doses, and 2%-2 mm gamma delivery passing rates. Relative to motionless ground truth conditions, PET/CT imaging errors were on the order of 10-20%, treatment planning errors were 5-10%, and treatment delivery errors were 5-30% without motion compensation. Errors from residual motion following compensation methods were reduced to 5-10% in PET/CT imaging, <5% in treatment planning, and <2% in treatment delivery. We have demonstrated that estimation of respiratory motion uncertainty and its propagation from PET/CT imaging to RT planning, and RT

  8. Electronic cameras for low-light microscopy.

    PubMed

    Rasnik, Ivan; French, Todd; Jacobson, Ken; Berland, Keith

    2013-01-01

    This chapter introduces to electronic cameras, discusses the various parameters considered for evaluating their performance, and describes some of the key features of different camera formats. The chapter also presents the basic understanding of functioning of the electronic cameras and how these properties can be exploited to optimize image quality under low-light conditions. Although there are many types of cameras available for microscopy, the most reliable type is the charge-coupled device (CCD) camera, which remains preferred for high-performance systems. If time resolution and frame rate are of no concern, slow-scan CCDs certainly offer the best available performance, both in terms of the signal-to-noise ratio and their spatial resolution. Slow-scan cameras are thus the first choice for experiments using fixed specimens such as measurements using immune fluorescence and fluorescence in situ hybridization. However, if video rate imaging is required, one need not evaluate slow-scan CCD cameras. A very basic video CCD may suffice if samples are heavily labeled or are not perturbed by high intensity illumination. When video rate imaging is required for very dim specimens, the electron multiplying CCD camera is probably the most appropriate at this technological stage. Intensified CCDs provide a unique tool for applications in which high-speed gating is required. The variable integration time video cameras are very attractive options if one needs to acquire images at video rate acquisition, as well as with longer integration times for less bright samples. This flexibility can facilitate many diverse applications with highly varied light levels.

  9. The Mars observer camera

    NASA Technical Reports Server (NTRS)

    Malin, M. C.; Danielson, G. E.; Ingersoll, A. P.; Masursky, H.; Veverka, J.; Soulanille, T.; Ravine, M.

    1987-01-01

    A camera designed to operate under the extreme constraints of the Mars Observer Mission was selected by NASA in April, 1986. Contingent upon final confirmation in mid-November, the Mars Observer Camera (MOC) will begin acquiring images of the surface and atmosphere of Mars in September-October 1991. The MOC incorporates both a wide angle system for low resolution global monitoring and intermediate resolution regional targeting, and a narrow angle system for high resolution selective surveys. Camera electronics provide control of image clocking and on-board, internal editing and buffering to match whatever spacecraft data system capabilities are allocated to the experiment. The objectives of the MOC experiment follow.

  10. Night Vision Camera

    NASA Technical Reports Server (NTRS)

    1996-01-01

    PixelVision, Inc. developed the Night Video NV652 Back-illuminated CCD Camera, based on the expertise of a former Jet Propulsion Laboratory employee and a former employee of Scientific Imaging Technologies, Inc. The camera operates without an image intensifier, using back-illuminated and thinned CCD technology to achieve extremely low light level imaging performance. The advantages of PixelVision's system over conventional cameras include greater resolution and better target identification under low light conditions, lower cost and a longer lifetime. It is used commercially for research and aviation.

  11. Kitt Peak speckle camera

    NASA Technical Reports Server (NTRS)

    Breckinridge, J. B.; Mcalister, H. A.; Robinson, W. G.

    1979-01-01

    The speckle camera in regular use at Kitt Peak National Observatory since 1974 is described in detail. The design of the atmospheric dispersion compensation prisms, the use of film as a recording medium, the accuracy of double star measurements, and the next generation speckle camera are discussed. Photographs of double star speckle patterns with separations from 1.4 sec of arc to 4.7 sec of arc are shown to illustrate the quality of image formation with this camera, the effects of seeing on the patterns, and to illustrate the isoplanatic patch of the atmosphere.

  12. Optimization of supervised cluster analysis for extracting reference tissue input curves in (R)-[11C]PK11195 brain PET studies

    PubMed Central

    Yaqub, Maqsood; van Berckel, Bart NM; Schuitemaker, Alie; Hinz, Rainer; Turkheimer, Federico E; Tomasi, Giampaolo; Lammertsma, Adriaan A; Boellaard, Ronald

    2012-01-01

    Performance of two supervised cluster analysis (SVCA) algorithms for extracting reference tissue curves was evaluated to improve quantification of dynamic (R)-[11C]PK11195 brain positron emission tomography (PET) studies. Reference tissues were extracted from images using both a manually defined cerebellum and SVCA algorithms based on either four (SVCA4) or six (SVCA6) kinetic classes. Data from controls, mild cognitive impairment patients, and patients with Alzheimer's disease were analyzed using various kinetic models including plasma input, the simplified reference tissue model (RPM) and RPM with vascular correction (RPMVb). In all subject groups, SVCA-based reference tissue curves showed lower blood volume fractions (Vb) and volume of distributions than those based on cerebellum time-activity curve. Probably resulting from the presence of specific signal from the vessel walls that contains in normal condition a significant concentration of the 18 kDa translocation protein. Best contrast between subject groups was seen using SVCA4-based reference tissues as the result of a lower number of kinetic classes and the prior removal of extracerebral tissues. In addition, incorporation of Vb in RPM improved both parametric images and binding potential contrast between groups. Incorporation of Vb within RPM, together with SVCA4, appears to be the method of choice for analyzing cerebral (R)-[11C]PK11195 neurodegeneration studies. PMID:22588187

  13. Optimization of supervised cluster analysis for extracting reference tissue input curves in (R)-[(11)C]PK11195 brain PET studies.

    PubMed

    Yaqub, Maqsood; van Berckel, Bart N M; Schuitemaker, Alie; Hinz, Rainer; Turkheimer, Federico E; Tomasi, Giampaolo; Lammertsma, Adriaan A; Boellaard, Ronald

    2012-08-01

    Performance of two supervised cluster analysis (SVCA) algorithms for extracting reference tissue curves was evaluated to improve quantification of dynamic (R)-[(11)C]PK11195 brain positron emission tomography (PET) studies. Reference tissues were extracted from images using both a manually defined cerebellum and SVCA algorithms based on either four (SVCA4) or six (SVCA6) kinetic classes. Data from controls, mild cognitive impairment patients, and patients with Alzheimer's disease were analyzed using various kinetic models including plasma input, the simplified reference tissue model (RPM) and RPM with vascular correction (RPMV(b)). In all subject groups, SVCA-based reference tissue curves showed lower blood volume fractions (V(b)) and volume of distributions than those based on cerebellum time-activity curve. Probably resulting from the presence of specific signal from the vessel walls that contains in normal condition a significant concentration of the 18 kDa translocation protein. Best contrast between subject groups was seen using SVCA4-based reference tissues as the result of a lower number of kinetic classes and the prior removal of extracerebral tissues. In addition, incorporation of V(b) in RPM improved both parametric images and binding potential contrast between groups. Incorporation of V(b) within RPM, together with SVCA4, appears to be the method of choice for analyzing cerebral (R)-[(11)C]PK11195 neurodegeneration studies.

  14. Do speed cameras reduce collisions?

    PubMed

    Skubic, Jeffrey; Johnson, Steven B; Salvino, Chris; Vanhoy, Steven; Hu, Chengcheng

    2013-01-01

    We investigated the effects of speed cameras along a 26 mile segment in metropolitan Phoenix, Arizona. Motor vehicle collisions were retrospectively identified according to three time periods - before cameras were placed, while cameras were in place and after cameras were removed. A 14 mile segment in the same area without cameras was used for control purposes. Five cofounding variables were eliminated. In this study, the placement or removal of interstate highway speed cameras did not independently affect the incidence of motor vehicle collisions.

  15. MO-FG-207-00: Technological Advances in PET/MR Imaging

    SciTech Connect

    2015-06-15

    The use of integrated PET/MRI systems in clinical applications can best benefit from understanding their technological advances and limitations. The currently available clinical PET/MRI systems have their own characteristics. Thorough analyses of existing technical data and evaluation of necessary performance metrics for quality assurances could be conducted to optimize application-specific PET/MRI protocols. This Symposium will focus on technical advances and limitations of clinical PET/MRI systems, and how this exciting imaging modality can be utilized in applications that can benefit from both PET and MRI. Learning Objectives: To understand the technological advances of clinical PET/MRI systems To correctly identify clinical applications that can benefit from PET/MRI To understand ongoing work to further improve the current PET/MRI technology Floris Jansen is a GE Healthcare employee.

  16. My Pet Rock

    ERIC Educational Resources Information Center

    Lark, Adam; Kramp, Robyne; Nurnberger-Haag, Julie

    2008-01-01

    Many teachers and students have experienced the classic pet rock experiment in conjunction with a geology unit. A teacher has students bring in a "pet" rock found outside of school, and the students run geologic tests on the rock. The tests include determining relative hardness using Mohs scale, checking for magnetization, and assessing luster.…

  17. Improving Instruction through PET.

    ERIC Educational Resources Information Center

    Evans, Pamela Roland

    1982-01-01

    Outlines the content and training methods used in the Program for Effective Teaching (PET), the successful staff development program of Newport News (Virginia). PET promotes application of five instructional skills: selecting learning objectives, teaching to the objectives, establishing learner focus, monitoring learner progress, and enhancing…

  18. Mobile PET Center Project

    NASA Astrophysics Data System (ADS)

    Ryzhikova, O.; Naumov, N.; Sergienko, V.; Kostylev, V.

    2017-01-01

    Positron emission tomography is the most promising technology to monitor cancer and heart disease treatment. Stationary PET center requires substantial financial resources and time for construction and equipping. The developed mobile solution will allow introducing PET technology quickly without major investments.

  19. PET with radiolabeled aminoacid.

    PubMed

    Crippa, F; Alessi, A; Serafini, G L

    2012-04-01

    Since the clinical introduction of FDG, neuroimaging has been the first area of PET application in oncology. Later, while FDG-PET became progressively a key imaging modality in the management of the majority of malignancies outside the brain, its neuro-oncologic indications faced some limitations because of the unfavourable characteristics of FDG as brain tumor-seeking agent. PET applications in neuro-oncology have received new effectiveness by the advent of positron-emission labelled amino acids, so that it has been coined the term "Amino acid PET" to differentiate this imaging tool from FDG-PET. Radiolabeled amino acids are a very interesting class of PET tracers with great diagnostic potential in neuro-oncology because of their low uptake in normal brain and, conversely, high uptake in most brain tumors including low-grade gliomas. The present article surveys the results obtained using L-[methyl-11C]Methionine (MET), that has been the ancestor of PET amino acid tracers and is still the most popular amino acid imaging modality in oncology, and stresses the important role that this diagnostic modality can play in the evaluation of brain tumors. However, the use of MET is restricted to PET centers with an in-house cyclotron and radiochemistry facility, because of the short half-life (20 min) of 11C. The promising results of MET have stimulated the development of 18F-labelled aminoacid tracers, particularly O-(2-18F-fluoeoethyl1)-L-tyrosine (FET), that has the same properties of MET and, thanks to the longer half-life of 18F (about 110 min), allows a distribution strategy from a production tracer site to user satellite PET centers. Considering a more widespread use of Amino acid PET, together with the recent development of integrated PET-MRI imaging systems, and the oncoming clinical validation of other interesting PET tracers, i.e. FMISO or 18F-FAZA for hypoxia imaging and FLT for tumor proliferation imaging, it can be reasonably expected that metabolic imaging

  20. Advanced CCD camera developments

    SciTech Connect

    Condor, A.

    1994-11-15

    Two charge coupled device (CCD) camera systems are introduced and discussed, describing briefly the hardware involved, and the data obtained in their various applications. The Advanced Development Group Defense Sciences Engineering Division has been actively designing, manufacturing, fielding state-of-the-art CCD camera systems for over a decade. These systems were originally developed for the nuclear test program to record data from underground nuclear tests. Today, new and interesting application for these systems have surfaced and development is continuing in the area of advanced CCD camera systems, with the new CCD camera that will allow experimenters to replace film for x-ray imaging at the JANUS, USP, and NOVA laser facilities.

  1. The MKID Camera

    NASA Astrophysics Data System (ADS)

    Maloney, P. R.; Czakon, N. G.; Day, P. K.; Duan, R.; Gao, J.; Glenn, J.; Golwala, S.; Hollister, M.; LeDuc, H. G.; Mazin, B.; Noroozian, O.; Nguyen, H. T.; Sayers, J.; Schlaerth, J.; Vaillancourt, J. E.; Vayonakis, A.; Wilson, P.; Zmuidzinas, J.

    2009-12-01

    The MKID Camera project is a collaborative effort of Caltech, JPL, the University of Colorado, and UC Santa Barbara to develop a large-format, multi-color millimeter and submillimeter-wavelength camera for astronomy using microwave kinetic inductance detectors (MKIDs). These are superconducting, micro-resonators fabricated from thin aluminum and niobium films. We couple the MKIDs to multi-slot antennas and measure the change in surface impedance produced by photon-induced breaking of Cooper pairs. The readout is almost entirely at room temperature and can be highly multiplexed; in principle hundreds or even thousands of resonators could be read out on a single feedline. The camera will have 576 spatial pixels that image simultaneously in four bands at 750, 850, 1100 and 1300 microns. It is scheduled for deployment at the Caltech Submillimeter Observatory in the summer of 2010. We present an overview of the camera design and readout and describe the current status of testing and fabrication.

  2. The Complementary Pinhole Camera.

    ERIC Educational Resources Information Center

    Bissonnette, D.; And Others

    1991-01-01

    Presents an experiment based on the principles of rectilinear motion of light operating in a pinhole camera that projects the image of an illuminated object through a small hole in a sheet to an image screen. (MDH)

  3. Spacecraft camera image registration

    NASA Technical Reports Server (NTRS)

    Kamel, Ahmed A. (Inventor); Graul, Donald W. (Inventor); Chan, Fred N. T. (Inventor); Gamble, Donald W. (Inventor)

    1987-01-01

    A system for achieving spacecraft camera (1, 2) image registration comprises a portion external to the spacecraft and an image motion compensation system (IMCS) portion onboard the spacecraft. Within the IMCS, a computer (38) calculates an image registration compensation signal (60) which is sent to the scan control loops (84, 88, 94, 98) of the onboard cameras (1, 2). At the location external to the spacecraft, the long-term orbital and attitude perturbations on the spacecraft are modeled. Coefficients (K, A) from this model are periodically sent to the onboard computer (38) by means of a command unit (39). The coefficients (K, A) take into account observations of stars and landmarks made by the spacecraft cameras (1, 2) themselves. The computer (38) takes as inputs the updated coefficients (K, A) plus synchronization information indicating the mirror position (AZ, EL) of each of the spacecraft cameras (1, 2), operating mode, and starting and stopping status of the scan lines generated by these cameras (1, 2), and generates in response thereto the image registration compensation signal (60). The sources of periodic thermal errors on the spacecraft are discussed. The system is checked by calculating measurement residuals, the difference between the landmark and star locations predicted at the external location and the landmark and star locations as measured by the spacecraft cameras (1, 2).

  4. Neutron cameras for ITER

    SciTech Connect

    Johnson, L.C.; Barnes, C.W.; Batistoni, P.

    1998-12-31

    Neutron cameras with horizontal and vertical views have been designed for ITER, based on systems used on JET and TFTR. The cameras consist of fan-shaped arrays of collimated flight tubes, with suitably chosen detectors situated outside the biological shield. The sight lines view the ITER plasma through slots in the shield blanket and penetrate the vacuum vessel, cryostat, and biological shield through stainless steel windows. This paper analyzes the expected performance of several neutron camera arrangements for ITER. In addition to the reference designs, the authors examine proposed compact cameras, in which neutron fluxes are inferred from {sup 16}N decay gammas in dedicated flowing water loops, and conventional cameras with fewer sight lines and more limited fields of view than in the reference designs. It is shown that the spatial sampling provided by the reference designs is sufficient to satisfy target measurement requirements and that some reduction in field of view may be permissible. The accuracy of measurements with {sup 16}N-based compact cameras is not yet established, and they fail to satisfy requirements for parameter range and time resolution by large margins.

  5. Thoracic cancer imaging with PET/CT in radiation oncology

    NASA Astrophysics Data System (ADS)

    Chi, Pai-Chun Melinda

    Significance. Respiratory motion has been shown to cause artifacts in PET/CT imaging. This breathing artifact can have a significant impact on PET quantification and it can lead to large uncertainties when using PET for radiation therapy planning. We have demonstrated a promising solution to resolve the breathing artifact by acquiring respiration-averaged CT (ACT) for PET/CT. The purpose of this work was to optimize the ACT acquisition for clinical implementation and to evaluate the impact of ACT on PET/CT quantification. The hypothesis was that ACT is an effective method in removing the breathing artifact when compared to our current clinical protocol. Methods. Phase and cine approaches for acquiring ACT were investigated and the results of these two approaches were compared to the ACT generated from clinical 4DCT data sets (abbreviated as ACT10phs ). In the phase approach, ACT was generated based on combinations of selected respiratory phases; in the cine approach, ACT was generated based on cine images acquired over a fixed cine duration. The phase combination and cine duration that best approximated the ACT10phs were determined to be the optimized scanning parameters. 216 thoracic PET/CT patients were scanned with both current clinical and the ACT protocols. The effects of ACT on PET/CT quantification were assessed by comparing clinical PET/CT and ACT PET/CT using 3 metrics: PET/CT image alignment, maximum standardized uptake value (SUVmax), and threshold segmented gross tumor volume (GTV). Results. ACT10phs can be best approximated to within 2% of SUV variation by phase averaging based on 4 representative phases, and to within 3% by cine image averaging based on >3s of cine duration. We implemented the cine approach on the PET/CT scanners and acquired 216 patient data sets. 68% of patients had breathing artifacts in their clinical PET/CT and the artifacts were removed/reduced in all corresponding ACT PET/CT. PET/CT quantification for lesions <50 cm3 and

  6. 1. VARIABLEANGLE LAUNCHER CAMERA CAR, VIEW OF CAMERA CAR AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. VARIABLE-ANGLE LAUNCHER CAMERA CAR, VIEW OF CAMERA CAR AND TRACK WITH CAMERA STATION ABOVE LOOKING NORTH TAKEN FROM RESERVOIR. - Variable Angle Launcher Complex, Camera Car & Track, CA State Highway 39 at Morris Reservior, Azusa, Los Angeles County, CA

  7. Development of a high resolution beta camera for a direct measurement of positron distribution on brain surface

    SciTech Connect

    Yamamoto, S.; Seki, C.; Kashikura, K.

    1996-12-31

    We have developed and tested a high resolution beta camera for a direct measurement of positron distribution on brain surface of animals. The beta camera consists of a thin CaF{sub 2}(Eu) scintillator, a tapered fiber optics plate (taper fiber) and a position sensitive photomultiplier tube (PSPMT). The taper fiber is the key component of the camera. We have developed two types of beta cameras. One is 20mm diameter field of view camera for imaging brain surface of cats. The other is 10mm diameter camera for that of rats. Spatial resolutions of beta camera for cats and rats were 0.8mm FWHM and 0.5mm FWHM, respectively. We confirmed that developed beta cameras may overcome the limitation of the spatial resolution of the positron emission tomography (PET).

  8. TOFPET ASIC for PET applications

    NASA Astrophysics Data System (ADS)

    Rolo, M. D.; Bugalho, R.; Gonçalves, F.; Mazza, G.; Rivetti, A.; Silva, J. C.; Silva, R.; Varela, J.

    2013-02-01

    A 64-channel ASIC for Time-of-Flight Positron Emission Tomography (TOF PET) imaging has been designed and simulated. The circuit is optimized for the readout of signals produced by the scintillation of a L(Y)SO crystal optically coupled to a silicon photomultiplier (SiPM). Developed in the framework of the EndoTOFPET-US collaboration [1], the ASIC is integrated in the external PET plate and performs timing, digitization and data transmission for 511 keV and lower-energy events due to Compton scattering. Multi-event buffering capability allows event rates up to 100 kHz per channel. The channel cell includes a low input impedance low-noise current conveyor and two trans-impedance amplifier branches separately optimized for energy and time resolution. Two voltage mode discriminators generate respectively a fast trigger for accurate timing and a signal for time-over-threshold calculation, used for charge measurement. The digitization of these signals is done by two low-power TDCs, providing coarse and fine time stamps that are saved into a local register and later managed by a global controller, which builds-up the 40-bit event data and runs the interface with the data acquisition back-end. Running at 160 MHz the chip yields a 50 ps time binning and dissipates ≊ 7 mW per channel (simulated for 40 kHz event rate p/channel) for high capacitance photodetectors (9 mm2 active area Silicon Photomultiplier with 320 pF terminal capacitance). The minimum SNR of 23.5 dB expected with this capacitance should allow triggering on the first photoelectron to achieve the envisaged timing performance for a TOF-PET system.

  9. Development of a PET/Cerenkov-light hybrid imaging system

    SciTech Connect

    Yamamoto, Seiichi Hamamura, Fuka; Kato, Katsuhiko; Ogata, Yoshimune; Watabe, Tadashi; Ikeda, Hayato; Kanai, Yasukazu; Hatazawa, Jun; Watabe, Hiroshi

    2014-09-15

    Purpose: Cerenkov-light imaging is a new molecular imaging technology that detects visible photons from high-speed electrons using a high sensitivity optical camera. However, the merit of Cerenkov-light imaging remains unclear. If a PET/Cerenkov-light hybrid imaging system were developed, the merit of Cerenkov-light imaging would be clarified by directly comparing these two imaging modalities. Methods: The authors developed and tested a PET/Cerenkov-light hybrid imaging system that consists of a dual-head PET system, a reflection mirror located above the subject, and a high sensitivity charge coupled device (CCD) camera. The authors installed these systems inside a black box for imaging the Cerenkov-light. The dual-head PET system employed a 1.2 × 1.2 × 10 mm{sup 3} GSO arranged in a 33 × 33 matrix that was optically coupled to a position sensitive photomultiplier tube to form a GSO block detector. The authors arranged two GSO block detectors 10 cm apart and positioned the subject between them. The Cerenkov-light above the subject is reflected by the mirror and changes its direction to the side of the PET system and is imaged by the high sensitivity CCD camera. Results: The dual-head PET system had a spatial resolution of ∼1.2 mm FWHM and sensitivity of ∼0.31% at the center of the FOV. The Cerenkov-light imaging system's spatial resolution was ∼275μm for a {sup 22}Na point source. Using the combined PET/Cerenkov-light hybrid imaging system, the authors successfully obtained fused images from simultaneously acquired images. The image distributions are sometimes different due to the light transmission and absorption in the body of the subject in the Cerenkov-light images. In simultaneous imaging of rat, the authors found that {sup 18}F-FDG accumulation was observed mainly in the Harderian gland on the PET image, while the distribution of Cerenkov-light was observed in the eyes. Conclusions: The authors conclude that their developed PET/Cerenkov-light hybrid

  10. Deployable Wireless Camera Penetrators

    NASA Technical Reports Server (NTRS)

    Badescu, Mircea; Jones, Jack; Sherrit, Stewart; Wu, Jiunn Jeng

    2008-01-01

    A lightweight, low-power camera dart has been designed and tested for context imaging of sampling sites and ground surveys from an aerobot or an orbiting spacecraft in a microgravity environment. The camera penetrators also can be used to image any line-of-sight surface, such as cliff walls, that is difficult to access. Tethered cameras to inspect the surfaces of planetary bodies use both power and signal transmission lines to operate. A tether adds the possibility of inadvertently anchoring the aerobot, and requires some form of station-keeping capability of the aerobot if extended examination time is required. The new camera penetrators are deployed without a tether, weigh less than 30 grams, and are disposable. They are designed to drop from any altitude with the boost in transmitting power currently demonstrated at approximately 100-m line-of-sight. The penetrators also can be deployed to monitor lander or rover operations from a distance, and can be used for surface surveys or for context information gathering from a touch-and-go sampling site. Thanks to wireless operation, the complexity of the sampling or survey mechanisms may be reduced. The penetrators may be battery powered for short-duration missions, or have solar panels for longer or intermittent duration missions. The imaging device is embedded in the penetrator, which is dropped or projected at the surface of a study site at 90 to the surface. Mirrors can be used in the design to image the ground or the horizon. Some of the camera features were tested using commercial "nanny" or "spy" camera components with the charge-coupled device (CCD) looking at a direction parallel to the ground. Figure 1 shows components of one camera that weighs less than 8 g and occupies a volume of 11 cm3. This camera could transmit a standard television signal, including sound, up to 100 m. Figure 2 shows the CAD models of a version of the penetrator. A low-volume array of such penetrator cameras could be deployed from an

  11. Structured light 3D tracking system for measuring motions in PET brain imaging

    NASA Astrophysics Data System (ADS)

    Olesen, Oline V.; Jørgensen, Morten R.; Paulsen, Rasmus R.; Højgaard, Liselotte; Roed, Bjarne; Larsen, Rasmus

    2010-02-01

    Patient motion during scanning deteriorates image quality, especially for high resolution PET scanners. A new proposal for a 3D head tracking system for motion correction in high resolution PET brain imaging is set up and demonstrated. A prototype tracking system based on structured light with a DLP projector and a CCD camera is set up on a model of the High Resolution Research Tomograph (HRRT). Methods to reconstruct 3D point clouds of simple surfaces based on phase-shifting interferometry (PSI) are demonstrated. The projector and camera are calibrated using a simple stereo vision procedure where the projector is treated as a camera. Additionally, the surface reconstructions are corrected for the non-linear projector output prior to image capture. The results are convincing and a first step toward a fully automated tracking system for measuring head motions in PET imaging.

  12. The contribution of PET/CT to improved patient management.

    PubMed

    Ell, P J

    2006-01-01

    With the introduction of both SPET/CT and PET/CT, multimodality imaging has truly entered routine clinical practice. Multiple slice spiral CT scanners have been incorporated with multiple detector gamma cameras or PET systems, such that the benefit of these modalities can be achieved in one patient sitting. The subject of this manuscript is PET/CT and its impact on patient management. Applications of PET/CT span the whole field of medical and surgical oncology since very few cancers do not take up the labelled glucose tracer, (18)F-FDG. Given the contrast achieved, high-quality data can be obtained with FDG PET/CT. This technology has now spread worldwide and has been the subject of intense interest, as witnessed by the vast body of published evidence. In this short overview, only a brief discussion of the main clinical applications is possible. Novel applications of PET/CT outside the field of oncology are expected in the near future.

  13. The VISTA IR camera

    NASA Astrophysics Data System (ADS)

    Dalton, Gavin B.; Caldwell, Martin; Ward, Kim; Whalley, Martin S.; Burke, Kevin; Lucas, John M.; Richards, Tony; Ferlet, Marc; Edeson, Ruben L.; Tye, Daniel; Shaughnessy, Bryan M.; Strachan, Mel; Atad-Ettedgui, Eli; Leclerc, Melanie R.; Gallie, Angus; Bezawada, Nagaraja N.; Clark, Paul; Bissonauth, Nirmal; Luke, Peter; Dipper, Nigel A.; Berry, Paul; Sutherland, Will; Emerson, Jim

    2004-09-01

    The VISTA IR Camera has now completed its detailed design phase and is on schedule for delivery to ESO"s Cerro Paranal Observatory in 2006. The camera consists of 16 Raytheon VIRGO 2048x2048 HgCdTe arrays in a sparse focal plane sampling a 1.65 degree field of view. A 1.4m diameter filter wheel provides slots for 7 distinct science filters, each comprising 16 individual filter panes. The camera also provides autoguiding and curvature sensing information for the VISTA telescope, and relies on tight tolerancing to meet the demanding requirements of the f/1 telescope design. The VISTA IR camera is unusual in that it contains no cold pupil-stop, but rather relies on a series of nested cold baffles to constrain the light reaching the focal plane to the science beam. In this paper we present a complete overview of the status of the final IR Camera design, its interaction with the VISTA telescope, and a summary of the predicted performance of the system.

  14. THE DARK ENERGY CAMERA

    SciTech Connect

    Flaugher, B.; Diehl, H. T.; Alvarez, O.; Angstadt, R.; Annis, J. T.; Buckley-Geer, E. J.; Honscheid, K.; Abbott, T. M. C.; Bonati, M.; Antonik, M.; Brooks, D.; Ballester, O.; Cardiel-Sas, L.; Beaufore, L.; Bernstein, G. M.; Bernstein, R. A.; Bigelow, B.; Boprie, D.; Campa, J.; Castander, F. J.; Collaboration: DES Collaboration; and others

    2015-11-15

    The Dark Energy Camera is a new imager with a 2.°2 diameter field of view mounted at the prime focus of the Victor M. Blanco 4 m telescope on Cerro Tololo near La Serena, Chile. The camera was designed and constructed by the Dark Energy Survey Collaboration and meets or exceeds the stringent requirements designed for the wide-field and supernova surveys for which the collaboration uses it. The camera consists of a five-element optical corrector, seven filters, a shutter with a 60 cm aperture, and a charge-coupled device (CCD) focal plane of 250 μm thick fully depleted CCDs cooled inside a vacuum Dewar. The 570 megapixel focal plane comprises 62 2k × 4k CCDs for imaging and 12 2k × 2k CCDs for guiding and focus. The CCDs have 15 μm × 15 μm pixels with a plate scale of 0.″263 pixel{sup −1}. A hexapod system provides state-of-the-art focus and alignment capability. The camera is read out in 20 s with 6–9 electron readout noise. This paper provides a technical description of the camera's engineering, construction, installation, and current status.

  15. The Dark Energy Camera

    SciTech Connect

    Flaugher, B.

    2015-04-11

    The Dark Energy Camera is a new imager with a 2.2-degree diameter field of view mounted at the prime focus of the Victor M. Blanco 4-meter telescope on Cerro Tololo near La Serena, Chile. The camera was designed and constructed by the Dark Energy Survey Collaboration, and meets or exceeds the stringent requirements designed for the wide-field and supernova surveys for which the collaboration uses it. The camera consists of a five element optical corrector, seven filters, a shutter with a 60 cm aperture, and a CCD focal plane of 250-μm thick fully depleted CCDs cooled inside a vacuum Dewar. The 570 Mpixel focal plane comprises 62 2k x 4k CCDs for imaging and 12 2k x 2k CCDs for guiding and focus. The CCDs have 15μm x 15μm pixels with a plate scale of 0.263" per pixel. A hexapod system provides state-of-the-art focus and alignment capability. The camera is read out in 20 seconds with 6-9 electrons readout noise. This paper provides a technical description of the camera's engineering, construction, installation, and current status.

  16. Satellite camera image navigation

    NASA Technical Reports Server (NTRS)

    Kamel, Ahmed A. (Inventor); Graul, Donald W. (Inventor); Savides, John (Inventor); Hanson, Charles W. (Inventor)

    1987-01-01

    Pixels within a satellite camera (1, 2) image are precisely located in terms of latitude and longitude on a celestial body, such as the earth, being imaged. A computer (60) on the earth generates models (40, 50) of the satellite's orbit and attitude, respectively. The orbit model (40) is generated from measurements of stars and landmarks taken by the camera (1, 2), and by range data. The orbit model (40) is an expression of the satellite's latitude and longitude at the subsatellite point, and of the altitude of the satellite, as a function of time, using as coefficients (K) the six Keplerian elements at epoch. The attitude model (50) is based upon star measurements taken by each camera (1, 2). The attitude model (50) is a set of expressions for the deviations in a set of mutually orthogonal reference optical axes (x, y, z) as a function of time, for each camera (1, 2). Measured data is fit into the models (40, 50) using a walking least squares fit algorithm. A transformation computer (66 ) transforms pixel coordinates as telemetered by the camera (1, 2) into earth latitude and longitude coordinates, using the orbit and attitude models (40, 50).

  17. The Dark Energy Camera

    DOE PAGES

    Flaugher, B.

    2015-04-11

    The Dark Energy Camera is a new imager with a 2.2-degree diameter field of view mounted at the prime focus of the Victor M. Blanco 4-meter telescope on Cerro Tololo near La Serena, Chile. The camera was designed and constructed by the Dark Energy Survey Collaboration, and meets or exceeds the stringent requirements designed for the wide-field and supernova surveys for which the collaboration uses it. The camera consists of a five element optical corrector, seven filters, a shutter with a 60 cm aperture, and a CCD focal plane of 250-μm thick fully depleted CCDs cooled inside a vacuum Dewar.more » The 570 Mpixel focal plane comprises 62 2k x 4k CCDs for imaging and 12 2k x 2k CCDs for guiding and focus. The CCDs have 15μm x 15μm pixels with a plate scale of 0.263" per pixel. A hexapod system provides state-of-the-art focus and alignment capability. The camera is read out in 20 seconds with 6-9 electrons readout noise. This paper provides a technical description of the camera's engineering, construction, installation, and current status.« less

  18. Neutron counting with cameras

    SciTech Connect

    Van Esch, Patrick; Crisanti, Marta; Mutti, Paolo

    2015-07-01

    A research project is presented in which we aim at counting individual neutrons with CCD-like cameras. We explore theoretically a technique that allows us to use imaging detectors as counting detectors at lower counting rates, and transits smoothly to continuous imaging at higher counting rates. As such, the hope is to combine the good background rejection properties of standard neutron counting detectors with the absence of dead time of integrating neutron imaging cameras as well as their very good spatial resolution. Compared to Xray detection, the essence of thermal neutron detection is the nuclear conversion reaction. The released energies involved are of the order of a few MeV, while X-ray detection releases energies of the order of the photon energy, which is in the 10 KeV range. Thanks to advances in camera technology which have resulted in increased quantum efficiency, lower noise, as well as increased frame rate up to 100 fps for CMOS-type cameras, this more than 100-fold higher available detection energy implies that the individual neutron detection light signal can be significantly above the noise level, as such allowing for discrimination and individual counting, which is hard to achieve with X-rays. The time scale of CMOS-type cameras doesn't allow one to consider time-of-flight measurements, but kinetic experiments in the 10 ms range are possible. The theory is next confronted to the first experimental results. (authors)

  19. CAOS-CMOS camera.

    PubMed

    Riza, Nabeel A; La Torre, Juan Pablo; Amin, M Junaid

    2016-06-13

    Proposed and experimentally demonstrated is the CAOS-CMOS camera design that combines the coded access optical sensor (CAOS) imager platform with the CMOS multi-pixel optical sensor. The unique CAOS-CMOS camera engages the classic CMOS sensor light staring mode with the time-frequency-space agile pixel CAOS imager mode within one programmable optical unit to realize a high dynamic range imager for extreme light contrast conditions. The experimentally demonstrated CAOS-CMOS camera is built using a digital micromirror device, a silicon point-photo-detector with a variable gain amplifier, and a silicon CMOS sensor with a maximum rated 51.3 dB dynamic range. White light imaging of three different brightness simultaneously viewed targets, that is not possible by the CMOS sensor, is achieved by the CAOS-CMOS camera demonstrating an 82.06 dB dynamic range. Applications for the camera include industrial machine vision, welding, laser analysis, automotive, night vision, surveillance and multispectral military systems.

  20. A Prototype Detector for a Novel High-Resolution PET System: BazookaPET.

    PubMed

    Park, Ryeojin; Miller, Brian W; Jha, Abhinav K; Furenlid, Lars R; Hunter, William C J; Barrett, Harrison H

    2012-01-01

    We have designed and are developing a novel proof-of-concept PET system called BazookaPET. In order to complete the PET configuration, at least two detector elements are required to detect positron-electron annihilation events. Each detector element of the BazookaPET has two independent data acquisition channels. One side of the scintillation crystal is optically coupled to a 4×4 silicon photomultiplier (SiPM) array and the other side is a CCD-based gamma camera. Using these two separate channels, we can obtain data with high energy, temporal and spatial resolution data by associating the data outputs via several maximum-likelihood estimation (MLE) steps. In this work, we present the concept of the system and the prototype detector element. We focus on characterizing individual detector channels, and initial experimental calibration results are shown along with preliminary performance-evaluation results. We measured energy resolution and the integrated traces of the slit-beam images from both detector channel outputs. A photo-peak energy resolution of ~5.3% FWHM was obtained from the SiPM and ~48% FWHM from the CCD at 662 keV. We assumed SiPM signals follow Gaussian statistics and estimated the 2D interaction position using MLE. Based on our the calibration experiments, we computed the Cramér-Rao bound (CRB) for the SiPM detector channel and found that the CRB resolution is better than 1 mm in the center of the crystal.

  1. Optimism

    PubMed Central

    Carver, Charles S.; Scheier, Michael F.; Segerstrom, Suzanne C.

    2010-01-01

    Optimism is an individual difference variable that reflects the extent to which people hold generalized favorable expectancies for their future. Higher levels of optimism have been related prospectively to better subjective well-being in times of adversity or difficulty (i.e., controlling for previous well-being). Consistent with such findings, optimism has been linked to higher levels of engagement coping and lower levels of avoidance, or disengagement, coping. There is evidence that optimism is associated with taking proactive steps to protect one's health, whereas pessimism is associated with health-damaging behaviors. Consistent with such findings, optimism is also related to indicators of better physical health. The energetic, task-focused approach that optimists take to goals also relates to benefits in the socioeconomic world. Some evidence suggests that optimism relates to more persistence in educational efforts and to higher later income. Optimists also appear to fare better than pessimists in relationships. Although there are instances in which optimism fails to convey an advantage, and instances in which it may convey a disadvantage, those instances are relatively rare. In sum, the behavioral patterns of optimists appear to provide models of living for others to learn from. PMID:20170998

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

    PubMed

    Ortuño, J E; Kontaxakis, G; Rubio, J L; Guerra, P; Santos, A

    2010-04-07

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

  3. Characterization and optimization of image quality as a function of reconstruction algorithms and parameter settings in a Siemens Inveon small-animal PET scanner using the NEMA NU 4-2008 standards

    NASA Astrophysics Data System (ADS)

    Visser, Eric P.; Disselhorst, Jonathan A.; van Lier, Monique G. J. T. B.; Laverman, Peter; de Jong, Gabie M.; Oyen, Wim J. G.; Boerman, Otto C.

    2011-02-01

    The image reconstruction algorithms provided with the Siemens Inveon small-animal PET scanner are filtered backprojection (FBP), 3-dimensional reprojection (3DRP), ordered subset expectation maximization in 2 or 3 dimensions (OSEM2D/3D) and maximum a posteriori (MAP) reconstruction. This study aimed at optimizing the reconstruction parameter settings with regard to image quality (IQ) as defined by the NEMA NU 4-2008 standards. The NEMA NU 4-2008 image quality phantom was used to determine image noise, expressed as percentage standard deviation in the uniform phantom region (%STD unif), activity recovery coefficients for the FDG-filled rods (RC rod), and spill-over ratios for the non-radioactive water- and air-filled phantom compartments (SOR wat and SOR air). Although not required by NEMA NU 4, we also determined a contrast-to-noise ratio for each rod (CNR rod), expressing the trade-off between activity recovery and image noise. For FBP and 3DRP the cut-off frequency of the applied filters, and for OSEM2D and OSEM3D, the number of iterations was varied. For MAP, the "smoothing parameter" β and the type of uniformity constraint (variance or resolution) were varied. Results of these analyses were demonstrated in images of an FDG-injected rat showing tumours in the liver, and of a mouse injected with an 18F-labeled peptide, showing a small subcutaneous tumour and the cortex structure of the kidneys. Optimum IQ in terms of CNR rod for the small-diameter rods was obtained using MAP with uniform variance and β=0.4. This setting led to RC rod,1 mm=0.21, RC rod,2 mm=0.57, %STD unif=1.38, SOR wat=0.0011, and SOR air=0.00086. However, the highest activity recovery for the smallest rods with still very small %STD unif was obtained using β=0.075, for which these IQ parameters were 0.31, 0.74, 2.67, 0.0041, and 0.0030, respectively. The different settings of reconstruction parameters were clearly reflected in the rat and mouse images as the trade-off between the recovery of

  4. HIGH SPEED CAMERA

    DOEpatents

    Rogers, B.T. Jr.; Davis, W.C.

    1957-12-17

    This patent relates to high speed cameras having resolution times of less than one-tenth microseconds suitable for filming distinct sequences of a very fast event such as an explosion. This camera consists of a rotating mirror with reflecting surfaces on both sides, a narrow mirror acting as a slit in a focal plane shutter, various other mirror and lens systems as well as an innage recording surface. The combination of the rotating mirrors and the slit mirror causes discrete, narrow, separate pictures to fall upon the film plane, thereby forming a moving image increment of the photographed event. Placing a reflecting surface on each side of the rotating mirror cancels the image velocity that one side of the rotating mirror would impart, so as a camera having this short a resolution time is thereby possible.

  5. Selective-imaging camera

    NASA Astrophysics Data System (ADS)

    Szu, Harold; Hsu, Charles; Landa, Joseph; Cha, Jae H.; Krapels, Keith A.

    2015-05-01

    How can we design cameras that image selectively in Full Electro-Magnetic (FEM) spectra? Without selective imaging, we cannot use, for example, ordinary tourist cameras to see through fire, smoke, or other obscurants contributing to creating a Visually Degraded Environment (VDE). This paper addresses a possible new design of selective-imaging cameras at firmware level. The design is consistent with physics of the irreversible thermodynamics of Boltzmann's molecular entropy. It enables imaging in appropriate FEM spectra for sensing through the VDE, and displaying in color spectra for Human Visual System (HVS). We sense within the spectra the largest entropy value of obscurants such as fire, smoke, etc. Then we apply a smart firmware implementation of Blind Sources Separation (BSS) to separate all entropy sources associated with specific Kelvin temperatures. Finally, we recompose the scene using specific RGB colors constrained by the HVS, by up/down shifting Planck spectra at each pixel and time.

  6. Electronic Still Camera

    NASA Technical Reports Server (NTRS)

    Holland, S. Douglas (Inventor)

    1992-01-01

    A handheld, programmable, digital camera is disclosed that supports a variety of sensors and has program control over the system components to provide versatility. The camera uses a high performance design which produces near film quality images from an electronic system. The optical system of the camera incorporates a conventional camera body that was slightly modified, thus permitting the use of conventional camera accessories, such as telephoto lenses, wide-angle lenses, auto-focusing circuitry, auto-exposure circuitry, flash units, and the like. An image sensor, such as a charge coupled device ('CCD') collects the photons that pass through the camera aperture when the shutter is opened, and produces an analog electrical signal indicative of the image. The analog image signal is read out of the CCD and is processed by preamplifier circuitry, a correlated double sampler, and a sample and hold circuit before it is converted to a digital signal. The analog-to-digital converter has an accuracy of eight bits to insure accuracy during the conversion. Two types of data ports are included for two different data transfer needs. One data port comprises a general purpose industrial standard port and the other a high speed/high performance application specific port. The system uses removable hard disks as its permanent storage media. The hard disk receives the digital image signal from the memory buffer and correlates the image signal with other sensed parameters, such as longitudinal or other information. When the storage capacity of the hard disk has been filled, the disk can be replaced with a new disk.

  7. Electronic still camera

    NASA Astrophysics Data System (ADS)

    Holland, S. Douglas

    1992-09-01

    A handheld, programmable, digital camera is disclosed that supports a variety of sensors and has program control over the system components to provide versatility. The camera uses a high performance design which produces near film quality images from an electronic system. The optical system of the camera incorporates a conventional camera body that was slightly modified, thus permitting the use of conventional camera accessories, such as telephoto lenses, wide-angle lenses, auto-focusing circuitry, auto-exposure circuitry, flash units, and the like. An image sensor, such as a charge coupled device ('CCD') collects the photons that pass through the camera aperture when the shutter is opened, and produces an analog electrical signal indicative of the image. The analog image signal is read out of the CCD and is processed by preamplifier circuitry, a correlated double sampler, and a sample and hold circuit before it is converted to a digital signal. The analog-to-digital converter has an accuracy of eight bits to insure accuracy during the conversion. Two types of data ports are included for two different data transfer needs. One data port comprises a general purpose industrial standard port and the other a high speed/high performance application specific port. The system uses removable hard disks as its permanent storage media. The hard disk receives the digital image signal from the memory buffer and correlates the image signal with other sensed parameters, such as longitudinal or other information. When the storage capacity of the hard disk has been filled, the disk can be replaced with a new disk.

  8. Heart PET scan

    MedlinePlus

    Heart nuclear medicine scan; Heart positron emission tomography; Myocardial PET scan ... Udelson JE, Dilsizian V, Bonow RO. Nuclear cardiology. In: Mann DL, ... A Textbook of Cardiovascular Medicine . 10th ed. Philadelphia, ...

  9. Pets and Pasteurella Infections

    MedlinePlus

    ... Ear Nose & Throat Emotional Problems Eyes Fever From Insects or Animals Genitals and Urinary Tract Glands & Growth ... Preventable Diseases Healthy Children > Health Issues > Conditions > From Insects or Animals > Pets and Pasteurella Infections Health Issues ...

  10. Appropriate and Inappropriate Pets.

    ERIC Educational Resources Information Center

    Soltow, Willow

    1985-01-01

    Presents an 11-lesson mini unit overview on wild and domestic pets. Lessons contain teacher preparation information and student activities. Skills, discipline orientation, and the humane concept associated with each lesson are also outlined. (ML)

  11. Brain PET scan

    MedlinePlus

    ... Tell the difference between Parkinson disease and other movement disorders Several PET scans may be taken to determine ... identify where the seizures start in your brain Movement disorders (such as Parkinson disease )

  12. Healthy Pets and People

    MedlinePlus

    ... Pregnant women should avoid adopting or handling stray cats, especially kittens. They particularly should not clean litter ... may be sick. Many pets, such as dogs, cats, reptiles, rodents, and birds, carry germs that can ...

  13. Artificial human vision camera

    NASA Astrophysics Data System (ADS)

    Goudou, J.-F.; Maggio, S.; Fagno, M.

    2014-10-01

    In this paper we present a real-time vision system modeling the human vision system. Our purpose is to inspire from human vision bio-mechanics to improve robotic capabilities for tasks such as objects detection and tracking. This work describes first the bio-mechanical discrepancies between human vision and classic cameras and the retinal processing stage that takes place in the eye, before the optic nerve. The second part describes our implementation of these principles on a 3-camera optical, mechanical and software model of the human eyes and associated bio-inspired attention model.

  14. Laser Range Camera Modeling

    SciTech Connect

    Storjohann, K.

    1990-01-01

    This paper describes an imaging model that was derived for use with a laser range camera (LRC) developed by the Advanced Intelligent Machines Division of Odetics. However, this model could be applied to any comparable imaging system. Both the derivation of the model and the determination of the LRC's intrinsic parameters are explained. For the purpose of evaluating the LRC's extrinsic parameters, i.e., its external orientation, a transformation of the LRC's imaging model into a standard camera's (SC) pinhole model is derived. By virtue of this transformation, the evaluation of the LRC's external orientation can be found by applying any SC calibration technique.

  15. PET studies in epilepsy

    PubMed Central

    Sarikaya, Ismet

    2015-01-01

    Various PET studies, such as measurements of glucose, serotonin and oxygen metabolism, cerebral blood flow and receptor bindings are availabe for epilepsy. 18Fluoro-2-deoxyglucose (18F-FDG) PET imaging of brain glucose metabolism is a well established and widely available technique. Studies have demonstrated that the sensitivity of interictal FDG-PET is higher than interictal SPECT and similar to ictal SPECT for the lateralization and localization of epileptogenic foci in presurgical patients refractory to medical treatments who have noncontributory EEG and MRI. In addition to localizing epileptogenic focus, FDG-PET provide additional important information on the functional status of the rest of the brain. The main limitation of interictal FDG-PET is that it cannot precisely define the surgical margin as the area of hypometabolism usually extends beyond the epileptogenic zone. Various neurotransmitters (GABA, glutamate, opiates, serotonin, dopamine, acethylcholine, and adenosine) and receptor subtypes are involved in epilepsy. PET receptor imaging studies performed in limited centers help to understand the role of neurotransmitters in epileptogenesis, identify epileptic foci and investigate new treatment approaches. PET receptor imaging studies have demonstrated reduced 11C-flumazenil (GABAA-cBDZ) and 18F-MPPF (5-HT1A serotonin) and increased 11C-cerfentanil (mu opiate) and 11C-MeNTI (delta opiate) bindings in the area of seizure. 11C-flumazenil has been reported to be more sensitive than FDG-PET for identifying epileptic foci. The area of abnormality on GABAAcBDZ and opiate receptor images is usually smaller and more circumscribed than the area of hypometabolism on FDG images. Studies have demonstrated that 11C-alpha-methyl-L-tryptophan PET (to study synthesis of serotonin) can detect the epileptic focus within malformations of cortical development and helps in differentiating epileptogenic from non-epileptogenic tubers in patients with tuberous sclerosis complex

  16. PET studies in epilepsy.

    PubMed

    Sarikaya, Ismet

    2015-01-01

    Various PET studies, such as measurements of glucose, serotonin and oxygen metabolism, cerebral blood flow and receptor bindings are availabe for epilepsy. (18)Fluoro-2-deoxyglucose ((18)F-FDG) PET imaging of brain glucose metabolism is a well established and widely available technique. Studies have demonstrated that the sensitivity of interictal FDG-PET is higher than interictal SPECT and similar to ictal SPECT for the lateralization and localization of epileptogenic foci in presurgical patients refractory to medical treatments who have noncontributory EEG and MRI. In addition to localizing epileptogenic focus, FDG-PET provide additional important information on the functional status of the rest of the brain. The main limitation of interictal FDG-PET is that it cannot precisely define the surgical margin as the area of hypometabolism usually extends beyond the epileptogenic zone. Various neurotransmitters (GABA, glutamate, opiates, serotonin, dopamine, acethylcholine, and adenosine) and receptor subtypes are involved in epilepsy. PET receptor imaging studies performed in limited centers help to understand the role of neurotransmitters in epileptogenesis, identify epileptic foci and investigate new treatment approaches. PET receptor imaging studies have demonstrated reduced (11)C-flumazenil (GABAA-cBDZ) and (18)F-MPPF (5-HT1A serotonin) and increased (11)C-cerfentanil (mu opiate) and (11)C-MeNTI (delta opiate) bindings in the area of seizure. (11)C-flumazenil has been reported to be more sensitive than FDG-PET for identifying epileptic foci. The area of abnormality on GABAAcBDZ and opiate receptor images is usually smaller and more circumscribed than the area of hypometabolism on FDG images. Studies have demonstrated that (11)C-alpha-methyl-L-tryptophan PET (to study synthesis of serotonin) can detect the epileptic focus within malformations of cortical development and helps in differentiating epileptogenic from non-epileptogenic tubers in patients with tuberous

  17. Modification of a medical PET scanner for PEPT studies

    NASA Astrophysics Data System (ADS)

    Sadrmomtaz, Alireza; Parker, D. J.; Byars, L. G.

    2007-04-01

    Over the last 20 years, positron emission tomography (PET) has developed as the most powerful functional imaging modality in medicine. Over the same period the University of Birmingham Positron Imaging Centre has applied PET to study engineering processes and developed the alternative technique of positron emission particle tracking (PEPT) in which a single radioactively labelled tracer particle is tracked by detecting simultaneously the pairs of back-to-back photons arising from positron/electron annihilation. Originally PEPT was performed using a pair of multiwire detectors, and more recently using a pair of digital gamma camera heads. In 2002 the Positron Imaging Centre acquired a medical PET scanner, an ECAT 931/08, previously used at Hammersmith Hospital. This scanner has been rebuilt in a flexible geometry for use in PEPT studies. This paper presents initial results from this system. Fast moving tracer particles can be rapidly and accurately located.

  18. Underwater camera with depth measurement

    NASA Astrophysics Data System (ADS)

    Wang, Wei-Chih; Lin, Keng-Ren; Tsui, Chi L.; Schipf, David; Leang, Jonathan

    2016-04-01

    The objective of this study is to develop an RGB-D (video + depth) camera that provides three-dimensional image data for use in the haptic feedback of a robotic underwater ordnance recovery system. Two camera systems were developed and studied. The first depth camera relies on structured light (as used by the Microsoft Kinect), where the displacement of an object is determined by variations of the geometry of a projected pattern. The other camera system is based on a Time of Flight (ToF) depth camera. The results of the structural light camera system shows that the camera system requires a stronger light source with a similar operating wavelength and bandwidth to achieve a desirable working distance in water. This approach might not be robust enough for our proposed underwater RGB-D camera system, as it will require a complete re-design of the light source component. The ToF camera system instead, allows an arbitrary placement of light source and camera. The intensity output of the broadband LED light source in the ToF camera system can be increased by putting them into an array configuration and the LEDs can be modulated comfortably with any waveform and frequencies required by the ToF camera. In this paper, both camera were evaluated and experiments were conducted to demonstrate the versatility of the ToF camera.

  19. Photogrammetric camera calibration

    USGS Publications Warehouse

    Tayman, W.P.; Ziemann, H.

    1984-01-01

    Section 2 (Calibration) of the document "Recommended Procedures for Calibrating Photogrammetric Cameras and Related Optical Tests" from the International Archives of Photogrammetry, Vol. XIII, Part 4, is reviewed in the light of recent practical work, and suggestions for changes are made. These suggestions are intended as a basis for a further discussion. ?? 1984.

  20. Make a Pinhole Camera

    ERIC Educational Resources Information Center

    Fisher, Diane K.; Novati, Alexander

    2009-01-01

    On Earth, using ordinary visible light, one can create a single image of light recorded over time. Of course a movie or video is light recorded over time, but it is a series of instantaneous snapshots, rather than light and time both recorded on the same medium. A pinhole camera, which is simple to make out of ordinary materials and using ordinary…

  1. Anger Camera Firmware

    SciTech Connect

    2010-11-19

    The firmware is responsible for the operation of Anger Camera Electronics, calculation of position, time of flight and digital communications. It provides a first stage analysis of 48 signals from 48 analog signals that have been converted to digital values using A/D convertors.

  2. Mars Observer camera

    NASA Technical Reports Server (NTRS)

    Malin, M. C.; Danielson, G. E.; Ingersoll, A. P.; Masursky, H.; Veverka, J.; Ravine, M. A.; Soulanille, T. A.

    1992-01-01

    The Mars Observer camera (MOC) is a three-component system (one narrow-angle and two wide-angle cameras) designed to take high spatial resolution pictures of the surface of Mars and to obtain lower spatial resolution, synoptic coverage of the planet's surface and atmosphere. The cameras are based on the 'push broom' technique; that is, they do not take 'frames' but rather build pictures, one line at a time, as the spacecraft moves around the planet in its orbit. MOC is primarily a telescope for taking extremely high resolution pictures of selected locations on Mars. Using the narrow-angle camera, areas ranging from 2.8 km x 2.8 km to 2.8 km x 25.2 km (depending on available internal digital buffer memory) can be photographed at about 1.4 m/pixel. Additionally, lower-resolution pictures (to a lowest resolution of about 11 m/pixel) can be acquired by pixel averaging; these images can be much longer, ranging up to 2.8 x 500 km at 11 m/pixel. High-resolution data will be used to study sediments and sedimentary processes, polar processes and deposits, volcanism, and other geologic/geomorphic processes.

  3. Snapshot polarimeter fundus camera.

    PubMed

    DeHoog, Edward; Luo, Haitao; Oka, Kazuhiko; Dereniak, Eustace; Schwiegerling, James

    2009-03-20

    A snapshot imaging polarimeter utilizing Savart plates is integrated into a fundus camera for retinal imaging. Acquired retinal images can be processed to reconstruct Stokes vector images, giving insight into the polarization properties of the retina. Results for images from a normal healthy retina and retinas with pathology are examined and compared.

  4. Jack & the Video Camera

    ERIC Educational Resources Information Center

    Charlan, Nathan

    2010-01-01

    This article narrates how the use of video camera has transformed the life of Jack Williams, a 10-year-old boy from Colorado Springs, Colorado, who has autism. The way autism affected Jack was unique. For the first nine years of his life, Jack remained in his world, alone. Functionally non-verbal and with motor skill problems that affected his…

  5. Spas color camera

    NASA Technical Reports Server (NTRS)

    Toffales, C.

    1983-01-01

    The procedures to be followed in assessing the performance of the MOS color camera are defined. Aspects considered include: horizontal and vertical resolution; value of the video signal; gray scale rendition; environmental (vibration and temperature) tests; signal to noise ratios; and white balance correction.

  6. Advanced Virgo phase cameras

    NASA Astrophysics Data System (ADS)

    van der Schaaf, L.; Agatsuma, K.; van Beuzekom, M.; Gebyehu, M.; van den Brand, J.

    2016-05-01

    A century after the prediction of gravitational waves, detectors have reached the sensitivity needed to proof their existence. One of them, the Virgo interferometer in Pisa, is presently being upgraded to Advanced Virgo (AdV) and will come into operation in 2016. The power stored in the interferometer arms raises from 20 to 700 kW. This increase is expected to introduce higher order modes in the beam, which could reduce the circulating power in the interferometer, limiting the sensitivity of the instrument. To suppress these higher-order modes, the core optics of Advanced Virgo is equipped with a thermal compensation system. Phase cameras, monitoring the real-time status of the beam constitute a critical component of this compensation system. These cameras measure the phases and amplitudes of the laser-light fields at the frequencies selected to control the interferometer. The measurement combines heterodyne detection with a scan of the wave front over a photodetector with pin-hole aperture. Three cameras observe the phase front of these laser sidebands. Two of them monitor the in-and output of the interferometer arms and the third one is used in the control of the aberrations introduced by the power recycling cavity. In this paper the working principle of the phase cameras is explained and some characteristic parameters are described.

  7. Communities, Cameras, and Conservation

    ERIC Educational Resources Information Center

    Patterson, Barbara

    2012-01-01

    Communities, Cameras, and Conservation (CCC) is the most exciting and valuable program the author has seen in her 30 years of teaching field science courses. In this citizen science project, students and community volunteers collect data on mountain lions ("Puma concolor") at four natural areas and public parks along the Front Range of Colorado.…

  8. The LSST Camera Overview

    SciTech Connect

    Gilmore, Kirk; Kahn, Steven A.; Nordby, Martin; Burke, David; O'Connor, Paul; Oliver, John; Radeka, Veljko; Schalk, Terry; Schindler, Rafe; /SLAC

    2007-01-10

    The LSST camera is a wide-field optical (0.35-1um) imager designed to provide a 3.5 degree FOV with better than 0.2 arcsecond sampling. The detector format will be a circular mosaic providing approximately 3.2 Gigapixels per image. The camera includes a filter mechanism and, shuttering capability. It is positioned in the middle of the telescope where cross-sectional area is constrained by optical vignetting and heat dissipation must be controlled to limit thermal gradients in the optical beam. The fast, f/1.2 beam will require tight tolerances on the focal plane mechanical assembly. The focal plane array operates at a temperature of approximately -100 C to achieve desired detector performance. The focal plane array is contained within an evacuated cryostat, which incorporates detector front-end electronics and thermal control. The cryostat lens serves as an entrance window and vacuum seal for the cryostat. Similarly, the camera body lens serves as an entrance window and gas seal for the camera housing, which is filled with a suitable gas to provide the operating environment for the shutter and filter change mechanisms. The filter carousel can accommodate 5 filters, each 75 cm in diameter, for rapid exchange without external intervention.

  9. Ultraminiature television camera

    NASA Technical Reports Server (NTRS)

    Deterville, R. J.; Drago, N.

    1967-01-01

    Ultraminiature television camera with a total volume of 20.25 cubic inches, requires 28 vdc power, operates on UHF and accommodates standard 8-mm optics. It uses microelectronic assembly packaging techniques and contains a magnetically deflected and electrostatically focused vidicon, automatic gain control circuit, power supply, and transmitter.

  10. Gesture recognition on smart cameras

    NASA Astrophysics Data System (ADS)

    Dziri, Aziz; Chevobbe, Stephane; Darouich, Mehdi

    2013-02-01

    Gesture recognition is a feature in human-machine interaction that allows more natural interaction without the use of complex devices. For this reason, several methods of gesture recognition have been developed in recent years. However, most real time methods are designed to operate on a Personal Computer with high computing resources and memory. In this paper, we analyze relevant methods found in the literature in order to investigate the ability of smart camera to execute gesture recognition algorithms. We elaborate two hand gesture recognition pipelines. The first method is based on invariant moments extraction and the second on finger tips detection. The hand detection method used for both pipeline is based on skin color segmentation. The results obtained show that the un-optimized versions of invariant moments method and finger tips detection method can reach 10 fps on embedded processor and use about 200 kB of memory.

  11. Illumination box and camera system

    DOEpatents

    Haas, Jeffrey S.; Kelly, Fredrick R.; Bushman, John F.; Wiefel, Michael H.; Jensen, Wayne A.; Klunder, Gregory L.

    2002-01-01

    A hand portable, field-deployable thin-layer chromatography (TLC) unit and a hand portable, battery-operated unit for development, illumination, and data acquisition of the TLC plates contain many miniaturized features that permit a large number of samples to be processed efficiently. The TLC unit includes a solvent tank, a holder for TLC plates, and a variety of tool chambers for storing TLC plates, solvent, and pipettes. After processing in the TLC unit, a TLC plate is positioned in a collapsible illumination box, where the box and a CCD camera are optically aligned for optimal pixel resolution of the CCD images of the TLC plate. The TLC system includes an improved development chamber for chemical development of TLC plates that prevents solvent overflow.

  12. The PAU Camera

    NASA Astrophysics Data System (ADS)

    Casas, R.; Ballester, O.; Cardiel-Sas, L.; Carretero, J.; Castander, F. J.; Castilla, J.; Crocce, M.; de Vicente, J.; Delfino, M.; Fernández, E.; Fosalba, P.; García-Bellido, J.; Gaztañaga, E.; Grañena, F.; Jiménez, J.; Madrid, F.; Maiorino, M.; Martí, P.; Miquel, R.; Neissner, C.; Ponce, R.; Sánchez, E.; Serrano, S.; Sevilla, I.; Tonello, N.; Troyano, I.

    2011-11-01

    The PAU Camera (PAUCam) is a wide-field camera designed to be mounted at the William Herschel Telescope (WHT) prime focus, located at the Observatorio del Roque de los Muchachos in the island of La Palma (Canary Islands).Its primary function is to carry out a cosmological survey, the PAU Survey, covering an area of several hundred square degrees of sky. Its purpose is to determine positions and distances using photometric redshift techniques. To achieve accurate photo-z's, PAUCam will be equipped with 40 narrow-band filters covering the range from 450 to850 nm, and six broad-band filters, those of the SDSS system plus the Y band. To fully cover the focal plane delivered by the telescope optics, 18 CCDs 2k x 4k are needed. The pixels are square of 15 μ m size. The optical characteristics of the prime focus corrector deliver a field-of-view where eight of these CCDs will have an illumination of more than 95% covering a field of 40 arc minutes. The rest of the CCDs will occupy the vignetted region extending the field diameter to one degree. Two of the CCDs will be devoted to auto-guiding.This camera have some innovative features. Firstly, both the broad-band and the narrow-band filters will be placed in mobile trays, hosting 16 such filters at most. Those are located inside the cryostat at few millimeters in front of the CCDs when observing. Secondly, a pressurized liquid nitrogen tank outside the camera will feed a boiler inside the cryostat with a controlled massflow. The read-out electronics will use the Monsoon architecture, originally developed by NOAO, modified and manufactured by our team in the frame of the DECam project (the camera used in the DES Survey).PAUCam will also be available to the astronomical community of the WHT.

  13. Image Sensors Enhance Camera Technologies

    NASA Technical Reports Server (NTRS)

    2010-01-01

    In the 1990s, a Jet Propulsion Laboratory team led by Eric Fossum researched ways of improving complementary metal-oxide semiconductor (CMOS) image sensors in order to miniaturize cameras on spacecraft while maintaining scientific image quality. Fossum s team founded a company to commercialize the resulting CMOS active pixel sensor. Now called the Aptina Imaging Corporation, based in San Jose, California, the company has shipped over 1 billion sensors for use in applications such as digital cameras, camera phones, Web cameras, and automotive cameras. Today, one of every three cell phone cameras on the planet feature Aptina s sensor technology.

  14. Do Speed Cameras Reduce Collisions?

    PubMed Central

    Skubic, Jeffrey; Johnson, Steven B.; Salvino, Chris; Vanhoy, Steven; Hu, Chengcheng

    2013-01-01

    We investigated the effects of speed cameras along a 26 mile segment in metropolitan Phoenix, Arizona. Motor vehicle collisions were retrospectively identified according to three time periods – before cameras were placed, while cameras were in place and after cameras were removed. A 14 mile segment in the same area without cameras was used for control purposes. Five cofounding variables were eliminated. In this study, the placement or removal of interstate highway speed cameras did not independently affect the incidence of motor vehicle collisions. PMID:24406979

  15. AprilTag array-aided extrinsic calibration of camera-laser multi-sensor system.

    PubMed

    Tang, Dengqing; Hu, Tianjiang; Shen, Lincheng; Ma, Zhaowei; Pan, Congyu

    This paper presents a new algorithm for extrinsically calibrating a multi-sensor system including multiple cameras and a 2D laser scanner. On the basis of the camera pose estimation using AprilTag, we design an AprilTag array as the calibration target and employ a nonlinear optimization to calculate the single-camera extrinsic parameters when multiple tags are in the field of view of the camera. The extrinsic parameters of camera-camera and laser-camera are then calibrated, respectively. A global optimization is finally used to refine all the extrinsic parameters by minimizing a re-projection error. This algorithm is adapted to the extrinsic calibration of multiple cameras even if there is non-overlapping field of view. For algorithm validation, we have built a micro-aerial vehicle platform with multi-sensor system to collect real data, and the experiment results confirmed that the proposed algorithm yields great performance.

  16. Repeatability of the Maximum Standard Uptake Value (SUVmax) in FDG PET

    PubMed Central

    Lindholm, Henry; Staaf, Johan; Jacobsson, Hans; Brolin, Fredrik; Hatherly, Robert; Sânchez-Crespo, Alejandro

    2014-01-01

    Objective: SUVmax is often calculated at FDG PET examinations in systematic studies as well as at clinical examinations. Since SUVmax represents a very small portion of a lesion it may be questioned how statistically reliable the figure is. This was studied by assessing the repeatability of SUVmax between two FDG acquisitions acquired immediately upon each other in patients with chest lesions. Methods: In 100 clinical patients with a known chest lesion, two identical 3 min PET registrations (PET1 and PET2, respectively) were initiated within 224±31 sec of each other. The difference in SUVmax between the lesion for the two PET scans (ΔSUVmax) was calculated and the uncertainty expressed as the coefficient of variation, CV (%). The correlation between ΔSUVmax and the lowest SUVmax from PET1 or PET2, the approximate metabolic lesion volume, the time from FDG injection to PET1 and the time between PET1 and PET2, respectively, was also assessed. Results: In 56 patients SUVmax increased at the second acquisition and in 44 patients it decreased. Mean of SUVmax was 7.8±6.1 and 7.8±6.2 for PET1 and PET2, respectively. The mean percentage difference was 0.9±7.8. The difference was not significant (p=0.20). CV gave an uncertainty of 4.3% between the two measurements which is a strong indicator of equivalence. There was no correlation between ΔSUVmax and any of the assessed four parameters. The difference between the acquisitions, 0.9%, was much lower compared to the 3 previous published similar, but more restricted studies where the difference was 2.5-8.2%. Conclusion: From camera and computational perspectives, SUVmax is a stable parameter Conflict of interest:None declared. PMID:24653930

  17. Dual cameras acquisition and display system of retina-like sensor camera and rectangular sensor camera

    NASA Astrophysics Data System (ADS)

    Cao, Nan; Cao, Fengmei; Lin, Yabin; Bai, Tingzhu; Song, Shengyu

    2015-04-01

    For a new kind of retina-like senor camera and a traditional rectangular sensor camera, dual cameras acquisition and display system need to be built. We introduce the principle and the development of retina-like senor. Image coordinates transformation and interpolation based on sub-pixel interpolation need to be realized for our retina-like sensor's special pixels distribution. The hardware platform is composed of retina-like senor camera, rectangular sensor camera, image grabber and PC. Combined the MIL and OpenCV library, the software program is composed in VC++ on VS 2010. Experience results show that the system can realizes two cameras' acquisition and display.

  18. Simultaneous {sup 68}Ga-DOTATOC-PET/MRI for IMRT Treatment Planning for Meningioma: First Experience

    SciTech Connect

    Thorwarth, Daniela; Henke, Guido; Mueller, Arndt-Christian; Reimold, Matthias; Beyer, Thomas; Boss, Andreas; Kolb, Armin; Pichler, Bernd; Pfannenberg, Christina

    2011-09-01

    Purpose: To evaluate intensity-modulated radiotherapy (IMRT) treatment planning based on simultaneous positron-emission tomography and magnetic resonance imaging (PET/MRI) of meningioma. Methods and Materials: A meningioma patient was examined prior to radiotherapy with dedicated planning computed tomography (CT), MRI, PET/CT with gallium-68-labeled DOTATOC ({sup 68}Ga-DOTATOC), and simultaneous {sup 68}Ga-DOTATOC-PET/MRI. The first gross target volume (GTV) was defined based on a combination of separate MR and {sup 68}Ga-DOTATOC-PET/CT imaging (GTV{sub PET/CT+MR}). Then, the simultaneous PET/MR images were used to delineate a second GTV (GTV{sub PET/MR}) by following exactly the same delineation strategy. After an isotropic expansion of those volumes by a 4-mm safety margin, the resulting planning target volumes (PTVs) were compared by calculating the intersection volume and the relative complements. A cross-evaluation of IMRT plans was performed, where the treatment plan created for the PTV{sub PET/CT+MR} was applied to the PET/MR-based PTV{sub PET/MR}. Results: Generally, target volumes for IMRT treatment planning did not differ between MRI plus {sup 68}Ga-DOTATOC-PET/CT and simultaneous PET/MR imaging. Only in certain regions of the GTV were differences observed. The overall volume of the PET/MR-based PTV was approximately the same as that obtained from PET/CT data. A small region of infiltrative tumor growth next to the main tumor mass was better visualized with combined PET/MR due to smaller PET voxel sizes and improved recovery. An IMRT treatment plan was optimized for the PTV{sub PET/CT+MR}. The evaluation of this plan with respect to the PTV{sub PET/MR} showed parts of the target volume that would not have received the full radiation dose after delineation of the tumor, based on simultaneous PET/MR. Conclusion: This case showed that differences in target volumes delineated on the basis of separate MR and PET/CT and simultaneous PET/MR may be observed that

  19. Calibration method of absolute orientation of camera optical axis

    NASA Astrophysics Data System (ADS)

    Xu, Yong; Guo, Pengyu; Zhang, Xiaohu; Ding, Shaowen; Su, Ang; Li, Lichun

    2013-08-01

    Camera calibration is one of the most basic and important processes in optical measuring field. Generally, the objective of camera calibration is to estimate the internal and external parameters of object cameras, while the orientation error of optical axis is not included yet. Orientation error of optical axis is a important factor, which seriously affects measuring precision in high-precision measurement field, especially for those distant aerospace measurement in which object distance is much longer than focal length, that lead to magnifying the orientation errors to thousands times. In order to eliminate the influence of orientation error of camera optical axis, the imaging model of camera is analysed and established in this paper, and the calibration method is also introduced: Firstly, we analyse the reasons that cause optical axis error and its influence. Then, we find the model of optical axis orientation error and imaging model of camera basing on it's practical physical meaning. Furthermore, we derive the bundle adjustment algorithm which could compute the internal and external camera parameters and absolute orientation of camera optical axis simultaneously at high precision. In numeric simulation, we solve the camera parameters by using bundle adjustment optimization algorithm, then we correct the image points by calibration results according to the model of optical axis error, and the simulation result shows that our calibration model is reliable, effective and precise.

  20. The ADNI PET Core: 2015

    PubMed Central

    Jagust, William J.; Landau, Susan M.; Koeppe, Robert A.; Reiman, Eric M.; Chen, Kewei; Mathis, Chester A.; Price, Julie C.; Foster, Norman L.; Wang, Angela Y.

    2015-01-01

    INTRODUCTION This paper reviews the work done in the ADNI PET core over the past 5 years, largely concerning techniques, methods, and results related to amyloid imaging in ADNI. METHODS The PET Core has utilized [18F]florbetapir routinely on ADNI participants, with over 1600 scans available for download. Four different laboratories are involved in data analysis, and have examined factors such as longitudinal florbetapir analysis, use of FDG-PET in clinical trials, and relationships between different biomarkers and cognition. RESULTS Converging evidence from the PET Core has indicated that cross-sectional and longitudinal florbetapir analyses require different reference regions. Studies have also examined the relationship between florbetapir data obtained immediately after injection, which reflects perfusion, and FDG-PET results. Finally, standardization has included the translation of florbetapir PET data to a centiloid scale. CONCLUSION The PET Core has demonstrated a variety of methods for standardization of biomarkers such as florbetapir PET in a multicenter setting. PMID:26194311

  1. Disaster Preparedness for Your Pet

    MedlinePlus

    ... put pets, pet owners, and first responders in danger. Even if you try to create a safe ... Contact local veterinary clinics, boarding facilities, and local animal shelters. Visit the Humane Society website to find ...

  2. Automated Camera Array Fine Calibration

    NASA Technical Reports Server (NTRS)

    Clouse, Daniel; Padgett, Curtis; Ansar, Adnan; Cheng, Yang

    2008-01-01

    Using aerial imagery, the JPL FineCalibration (JPL FineCal) software automatically tunes a set of existing CAHVOR camera models for an array of cameras. The software finds matching features in the overlap region between images from adjacent cameras, and uses these features to refine the camera models. It is not necessary to take special imagery of a known target and no surveying is required. JPL FineCal was developed for use with an aerial, persistent surveillance platform.

  3. Streak camera receiver definition study

    NASA Technical Reports Server (NTRS)

    Johnson, C. B.; Hunkler, L. T., Sr.; Letzring, S. A.; Jaanimagi, P.

    1990-01-01

    Detailed streak camera definition studies were made as a first step toward full flight qualification of a dual channel picosecond resolution streak camera receiver for the Geoscience Laser Altimeter and Ranging System (GLRS). The streak camera receiver requirements are discussed as they pertain specifically to the GLRS system, and estimates of the characteristics of the streak camera are given, based upon existing and near-term technological capabilities. Important problem areas are highlighted, and possible corresponding solutions are discussed.

  4. LSST Camera Optics

    SciTech Connect

    Olivier, S S; Seppala, L; Gilmore, K; Hale, L; Whistler, W

    2006-06-05

    The Large Synoptic Survey Telescope (LSST) is a unique, three-mirror, modified Paul-Baker design with an 8.4m primary, a 3.4m secondary, and a 5.0m tertiary feeding a camera system that includes corrector optics to produce a 3.5 degree field of view with excellent image quality (<0.3 arcsecond 80% encircled diffracted energy) over the entire field from blue to near infra-red wavelengths. We describe the design of the LSST camera optics, consisting of three refractive lenses with diameters of 1.6m, 1.0m and 0.7m, along with a set of interchangeable, broad-band, interference filters with diameters of 0.75m. We also describe current plans for fabricating, coating, mounting and testing these lenses and filters.

  5. Combustion pinhole camera system

    DOEpatents

    Witte, Arvel B.

    1984-02-21

    A pinhole camera system utilizing a sealed optical-purge assembly which provides optical access into a coal combustor or other energy conversion reactors. The camera system basically consists of a focused-purge pinhole optical port assembly, a conventional TV vidicon receiver, an external, variable density light filter which is coupled electronically to the vidicon automatic gain control (agc). The key component of this system is the focused-purge pinhole optical port assembly which utilizes a purging inert gas to keep debris from entering the port and a lens arrangement which transfers the pinhole to the outside of the port assembly. One additional feature of the port assembly is that it is not flush with the interior of the combustor.

  6. Combustion pinhole camera system

    DOEpatents

    Witte, A.B.

    1984-02-21

    A pinhole camera system is described utilizing a sealed optical-purge assembly which provides optical access into a coal combustor or other energy conversion reactors. The camera system basically consists of a focused-purge pinhole optical port assembly, a conventional TV vidicon receiver, an external, variable density light filter which is coupled electronically to the vidicon automatic gain control (agc). The key component of this system is the focused-purge pinhole optical port assembly which utilizes a purging inert gas to keep debris from entering the port and a lens arrangement which transfers the pinhole to the outside of the port assembly. One additional feature of the port assembly is that it is not flush with the interior of the combustor. 2 figs.

  7. MO-FG-207-03: Maximizing the Utility of Integrated PET/MRI in Clinical Applications

    SciTech Connect

    Behr, S.

    2015-06-15

    The use of integrated PET/MRI systems in clinical applications can best benefit from understanding their technological advances and limitations. The currently available clinical PET/MRI systems have their own characteristics. Thorough analyses of existing technical data and evaluation of necessary performance metrics for quality assurances could be conducted to optimize application-specific PET/MRI protocols. This Symposium will focus on technical advances and limitations of clinical PET/MRI systems, and how this exciting imaging modality can be utilized in applications that can benefit from both PET and MRI. Learning Objectives: To understand the technological advances of clinical PET/MRI systems To correctly identify clinical applications that can benefit from PET/MRI To understand ongoing work to further improve the current PET/MRI technology Floris Jansen is a GE Healthcare employee.

  8. Hemispherical Laue camera

    DOEpatents

    Li, James C. M.; Chu, Sungnee G.

    1980-01-01

    A hemispherical Laue camera comprises a crystal sample mount for positioning a sample to be analyzed at the center of sphere of a hemispherical, X-radiation sensitive film cassette, a collimator, a stationary or rotating sample mount and a set of standard spherical projection spheres. X-radiation generated from an external source is directed through the collimator to impinge onto the single crystal sample on the stationary mount. The diffracted beam is recorded on the hemispherical X-radiation sensitive film mounted inside the hemispherical film cassette in either transmission or back-reflection geometry. The distances travelled by X-radiation diffracted from the crystal to the hemispherical film are the same for all crystal planes which satisfy Bragg's Law. The recorded diffraction spots or Laue spots on the film thereby preserve both the symmetry information of the crystal structure and the relative intensities which are directly related to the relative structure factors of the crystal orientations. The diffraction pattern on the exposed film is compared with the known diffraction pattern on one of the standard spherical projection spheres for a specific crystal structure to determine the orientation of the crystal sample. By replacing the stationary sample support with a rotating sample mount, the hemispherical Laue camera can be used for crystal structure determination in a manner previously provided in conventional Debye-Scherrer cameras.

  9. Gamma ray camera

    DOEpatents

    Perez-Mendez, V.

    1997-01-21

    A gamma ray camera is disclosed for detecting rays emanating from a radiation source such as an isotope. The gamma ray camera includes a sensor array formed of a visible light crystal for converting incident gamma rays to a plurality of corresponding visible light photons, and a photosensor array responsive to the visible light photons in order to form an electronic image of the radiation therefrom. The photosensor array is adapted to record an integrated amount of charge proportional to the incident gamma rays closest to it, and includes a transparent metallic layer, photodiode consisting of a p-i-n structure formed on one side of the transparent metallic layer, and comprising an upper p-type layer, an intermediate layer and a lower n-type layer. In the preferred mode, the scintillator crystal is composed essentially of a cesium iodide (CsI) crystal preferably doped with a predetermined amount impurity, and the p-type upper intermediate layers and said n-type layer are essentially composed of hydrogenated amorphous silicon (a-Si:H). The gamma ray camera further includes a collimator interposed between the radiation source and the sensor array, and a readout circuit formed on one side of the photosensor array. 6 figs.

  10. Gamma ray camera

    DOEpatents

    Perez-Mendez, Victor

    1997-01-01

    A gamma ray camera for detecting rays emanating from a radiation source such as an isotope. The gamma ray camera includes a sensor array formed of a visible light crystal for converting incident gamma rays to a plurality of corresponding visible light photons, and a photosensor array responsive to the visible light photons in order to form an electronic image of the radiation therefrom. The photosensor array is adapted to record an integrated amount of charge proportional to the incident gamma rays closest to it, and includes a transparent metallic layer, photodiode consisting of a p-i-n structure formed on one side of the transparent metallic layer, and comprising an upper p-type layer, an intermediate layer and a lower n-type layer. In the preferred mode, the scintillator crystal is composed essentially of a cesium iodide (CsI) crystal preferably doped with a predetermined amount impurity, and the p-type upper intermediate layers and said n-type layer are essentially composed of hydrogenated amorphous silicon (a-Si:H). The gamma ray camera further includes a collimator interposed between the radiation source and the sensor array, and a readout circuit formed on one side of the photosensor array.

  11. Orbiter Camera Payload System

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Components for an orbiting camera payload system (OCPS) include the large format camera (LFC), a gas supply assembly, and ground test, handling, and calibration hardware. The LFC, a high resolution large format photogrammetric camera for use in the cargo bay of the space transport system, is also adaptable to use on an RB-57 aircraft or on a free flyer satellite. Carrying 4000 feet of film, the LFC is usable over the visible to near IR, at V/h rates of from 11 to 41 milliradians per second, overlap of 10, 60, 70 or 80 percent and exposure times of from 4 to 32 milliseconds. With a 12 inch focal length it produces a 9 by 18 inch format (long dimension in line of flight) with full format low contrast resolution of 88 lines per millimeter (AWAR), full format distortion of less than 14 microns and a complement of 45 Reseau marks and 12 fiducial marks. Weight of the OCPS as supplied, fully loaded is 944 pounds and power dissipation is 273 watts average when in operation, 95 watts in standby. The LFC contains an internal exposure sensor, or will respond to external command. It is able to photograph starfields for inflight calibration upon command.

  12. The DRAGO gamma camera

    SciTech Connect

    Fiorini, C.; Gola, A.; Peloso, R.; Longoni, A.; Lechner, P.; Soltau, H.; Strueder, L.; Ottobrini, L.; Martelli, C.; Lui, R.; Madaschi, L.; Belloli, S.

    2010-04-15

    In this work, we present the results of the experimental characterization of the DRAGO (DRift detector Array-based Gamma camera for Oncology), a detection system developed for high-spatial resolution gamma-ray imaging. This camera is based on a monolithic array of 77 silicon drift detectors (SDDs), with a total active area of 6.7 cm{sup 2}, coupled to a single 5-mm-thick CsI(Tl) scintillator crystal. The use of an array of SDDs provides a high quantum efficiency for the detection of the scintillation light together with a very low electronics noise. A very compact detection module based on the use of integrated readout circuits was developed. The performances achieved in gamma-ray imaging using this camera are reported here. When imaging a 0.2 mm collimated {sup 57}Co source (122 keV) over different points of the active area, a spatial resolution ranging from 0.25 to 0.5 mm was measured. The depth-of-interaction capability of the detector, thanks to the use of a Maximum Likelihood reconstruction algorithm, was also investigated by imaging a collimated beam tilted to an angle of 45 deg. with respect to the scintillator surface. Finally, the imager was characterized with in vivo measurements on mice, in a real preclinical environment.

  13. A Novel Camera Calibration Method Based on Polar Coordinate

    PubMed Central

    Gai, Shaoyan; Da, Feipeng; Fang, Xu

    2016-01-01

    A novel calibration method based on polar coordinate is proposed. The world coordinates are expressed in the form of polar coordinates, which are converted to world coordinates in the calibration process. In the beginning, the calibration points are obtained in polar coordinates. By transformation between polar coordinates and rectangular coordinates, the points turn into form of rectangular coordinates. Then, the points are matched with the corresponding image coordinates. At last, the parameters are obtained by objective function optimization. By the proposed method, the relationships between objects and cameras are expressed in polar coordinates easily. It is suitable for multi-camera calibration. Cameras can be calibrated with fewer points. The calibration images can be positioned according to the location of cameras. The experiment results demonstrate that the proposed method is an efficient calibration method. By the method, cameras are calibrated conveniently with high accuracy. PMID:27798651

  14. Commercial and PET radioisotope manufacturing with a medical cyclotron

    NASA Astrophysics Data System (ADS)

    Boothe, T. E.; McLeod, T. F.; Plitnikas, M.; Kinney, D.; Tavano, E.; Feijoo, Y.; Smith, P.; Szelecsényi, F.

    1993-06-01

    Mount Sinai has extensive experience in producing radionuclides for commercial sales and for incorporation into radiopharmaceuticals, including PET. Currently, an attempt is being made to supply radiochemicals to radiopharmaceutical manufacturers outside the hospital, to prepare radiopharmaceuticals for in-house use, and to prepare PET radiopharmaceuticals, such as 2-[F-18] FDG, for outside sales. This use for both commercial and PET manufacturing is atypical for a hospital-based cyclotron. To accomplish PET radiopharmaceutical sales, the hospital operates a nuclear pharmacy. A review of operational details for the past several years shows a continuing dependence on commercial sales which is reflected in research and developmental aspects and in staffing. Developmental efforts have centered primarily on radionuclide production, target development, and radiochemical processing optimization.

  15. Maximizing the Performance of Automated Low Cost All-sky Cameras

    NASA Technical Reports Server (NTRS)

    Bettonvil, F.

    2011-01-01

    Thanks to the wide spread of digital camera technology in the consumer market, a steady increase in the number of active All-sky camera has be noticed European wide. In this paper I look into the details of such All-sky systems and try to optimize the performance in terms of accuracy of the astrometry, the velocity determination and photometry. Having autonomous operation in mind, suggestions are done for the optimal low cost All-sky camera.

  16. Detector Technologies for Sub-500um High-Sensitivity PET Imaging via a Novel PET Insert Approach

    SciTech Connect

    Tai, Yuan-Chuan

    2011-12-21

    The objective of this project was to develop detector technologies that would enable an ultrahigh resolution Virtual Pinhole (VP) PET insert device to provide sub-500 um resolution high-sensitivity PET imaging of a mouse in the future. To achieve this goal, we proposed to develop and characterize finely pixellated cadmium zinc telluride (CZT) detectors and the associated readout electronics with the following specific aims: 1. Develop pixellated CZT detectors with 350um pitches using 2-5 mm substrates; characterize their spatial, energy and timing performance through experiments; and optimize the anode design with steering grid if found necessary. 2. Develop a high-bandwidth readout system using a novel ASIC that can be directly bonded to CZT detectors with 2048 anodes of 350um pitches; optimize its overall performance for VP-PET applications considering the tradeoffs between spatial resolution (in 3D), count rate capability, timing and energy resolutions. 3. Evaluate the performance of a VP-PET insert based on the proposed detector technology through Monte Carlo simulation and experimental validation. Overall, we have completed all three specific aims and demonstrated that pixelated CZT detectors of 350um pitches, combined with VP-PET geometry, can provide PET image resolution of ~460 um FWHM for small animal imaging applications.

  17. Efficacy of novel robotic camera vs a standard laparoscopic camera.

    PubMed

    Strong, Vivian E M; Hogle, Nancy J; Fowler, Dennis L

    2005-12-01

    To improve visualization during minimal access surgery, a novel robotic camera has been developed. The prototype camera is totally insertable, has 5 degrees of freedom, and is remotely controlled. This study compared the performance of laparoscopic surgeons using both a laparoscope and the robotic camera. The MISTELS (McGill Inanimate System for the Training and Evaluation of Laparoscopic Skill) tasks were used to test six laparoscopic fellows and attending surgeons. Half the surgeons used the laparoscope first and half used the robotic camera first. Total scores from the MISTELS sessions in which the laparoscope was used were compared with the sessions in which the robotic camera was used and then analyzed with a paired t test (P < .05 was considered significant). All six surgeons tested showed no significant difference in their MISTELS task performance on the robotic camera compared with the standard laparoscopic camera. The mean MISTELS score of 963 for all subjects who used a laparoscope and camera was not significantly different than the mean score of 904 for the robotic camera (P = .17). This new robotic camera prototype allows for equivalent performance on a validated laparoscopic assessment tool when compared with performance using a standard laparoscope.

  18. Predictive and prognostic value of FDG-PET

    PubMed Central

    Oyen, Wim J.G.

    2008-01-01

    Abstract The predictive and prognostic value of fluorodeoxyglucose (FDG)-positron emission tomography (PET) in non-small-cell lung carcinoma, colorectal carcinoma and lymphoma is discussed. The degree of FDG uptake is of prognostic value at initial presentation, after induction treatment prior to resection and in the case of relapse of non-small cell lung cancer (NSCLC). In locally advanced and advanced stages of NSCLC, FDG-PET has been shown to be predictive for clinical outcome at an early stage of treatment. In colorectal carcinoma, limited studies are available on the prognostic value of FDG-PET, however, the technique appears to have great potential in monitoring the success of local ablative therapies soon after intervention and in the prediction and evaluation of response to radiotherapy, systemic therapy, and combinations thereof. The prognostic value of end-of treatment FDG-PET for FDG-avid lymphomas has been established, and the next step is to define how to use this information to optimize patient outcome. In Hodgkin's lymphoma, FDG-PET has a high negative predictive value, however, histological confirmation of positive findings should be sought where possible. For non-Hodgkin's lymphoma, the opposite applies. The newly published standardized guidelines for interpretation formulates specific criteria for visual interpretation and for defining PET positivity in the liver, spleen, lung, bone marrow and small residual lesions. The introduction of these guidelines should reduce variability among studies. Interim PET offers a reliable method for early prediction of long-term remission, however it should only be performed in prospective randomized controlled trials. Many of the diagnostic and management questions considered in this review are relevant to other tumour types. Further research in this field is of great importance, since it may lead to a change in the therapeutic concept of cancer. The preliminary findings call for systematic inclusion of FDG-PET

  19. [Pets, veterinarians, and multicultural society].

    PubMed

    Klumpers, M; Endenburg, N

    2009-01-15

    Dutch society comprises a growing percentage of non-Western ethnic minority groups. Little is known about pet ownership among these groups. This study explores some aspects of pet ownership, and the position of veterinarians, among the four largest non-Western ethnic minority groups in the Netherlands. Information was gathered through street interviews with people from a Moroccan, Turkish, Surinamese, or Antillean (including Aruban) background. Five hundred people where interviewed, including 41 pet owners. Results showed that people from non-Western ethnic minorities kept pets less often than Dutch people, with fish and birds being the most frequently kept pets. The number of visits to the veterinary clinic was comparable to that of Dutch pet owners; however, reasons given for the last visit were different. People from non-Western ethnic minorities mostly visited a veterinarian if their pet was ill whereas Dutch people visited the veterinarian if their pet needed to be vaccinated. People from non-Western ethnic minorities were positive about veterinarians, considering that they had sufficient knowledge about and concern for their pets. Moreover, veterinarians were trusted and provided understandable information--the respondents felt that they could go to their veterinarian with any question or problem regarding their pets. Although most respondents considered a visit to the veterinarian expensive, they were more than willing to invest in their pet's health.

  20. Optical Design of the LSST Camera

    SciTech Connect

    Olivier, S S; Seppala, L; Gilmore, K

    2008-07-16

    The Large Synoptic Survey Telescope (LSST) uses a novel, three-mirror, modified Paul-Baker design, with an 8.4-meter primary mirror, a 3.4-m secondary, and a 5.0-m tertiary feeding a camera system that includes a set of broad-band filters and refractive corrector lenses to produce a flat focal plane with a field of view of 9.6 square degrees. Optical design of the camera lenses and filters is integrated with optical design of telescope mirrors to optimize performance, resulting in excellent image quality over the entire field from ultra-violet to near infra-red wavelengths. The LSST camera optics design consists of three refractive lenses with clear aperture diameters of 1.55 m, 1.10 m and 0.69 m and six interchangeable, broad-band, filters with clear aperture diameters of 0.75 m. We describe the methodology for fabricating, coating, mounting and testing these lenses and filters, and we present the results of detailed tolerance analyses, demonstrating that the camera optics will perform to the specifications required to meet their performance goals.

  1. Multimodal sensing-based camera applications

    NASA Astrophysics Data System (ADS)

    Bordallo López, Miguel; Hannuksela, Jari; Silvén, J. Olli; Vehviläinen, Markku

    2011-02-01

    The increased sensing and computing capabilities of mobile devices can provide for enhanced mobile user experience. Integrating the data from different sensors offers a way to improve application performance in camera-based applications. A key advantage of using cameras as an input modality is that it enables recognizing the context. Therefore, computer vision has been traditionally utilized in user interfaces to observe and automatically detect the user actions. The imaging applications can also make use of various sensors for improving the interactivity and the robustness of the system. In this context, two applications fusing the sensor data with the results obtained from video analysis have been implemented on a Nokia Nseries mobile device. The first solution is a real-time user interface that can be used for browsing large images. The solution enables the display to be controlled by the motion of the user's hand using the built-in sensors as complementary information. The second application is a real-time panorama builder that uses the device's accelerometers to improve the overall quality, providing also instructions during the capture. The experiments show that fusing the sensor data improves camera-based applications especially when the conditions are not optimal for approaches using camera data alone.

  2. Digital Camera Control for Faster Inspection

    NASA Technical Reports Server (NTRS)

    Brown, Katharine; Siekierski, James D.; Mangieri, Mark L.; Dekome, Kent; Cobarruvias, John; Piplani, Perry J.; Busa, Joel

    2009-01-01

    Digital Camera Control Software (DCCS) is a computer program for controlling a boom and a boom-mounted camera used to inspect the external surface of a space shuttle in orbit around the Earth. Running in a laptop computer in the space-shuttle crew cabin, DCCS commands integrated displays and controls. By means of a simple one-button command, a crewmember can view low- resolution images to quickly spot problem areas and can then cause a rapid transition to high- resolution images. The crewmember can command that camera settings apply to a specific small area of interest within the field of view of the camera so as to maximize image quality within that area. DCCS also provides critical high-resolution images to a ground screening team, which analyzes the images to assess damage (if any); in so doing, DCCS enables the team to clear initially suspect areas more quickly than would otherwise be possible and further saves time by minimizing the probability of re-imaging of areas already inspected. On the basis of experience with a previous version (2.0) of the software, the present version (3.0) incorporates a number of advanced imaging features that optimize crewmember capability and efficiency.

  3. Polarisation-based coincidence event discrimination: an in silico study towards a feasible scheme for Compton-PET.

    PubMed

    Toghyani, M; Gillam, J E; McNamara, A L; Kuncic, Z

    2016-08-07

    Current positron emission tomography (PET) systems use temporally localised coincidence events discriminated by energy and time-of-flight information. The two annihilation photons are in an entangled polarisation state and, in principle, additional information from the polarisation correlation of photon pairs could be used to improve the accuracy of coincidence classification. In a previous study, we demonstrated that in principle, the polarisation correlation information could be transferred to an angular correlation in the distribution of scattered photon pairs in a planar Compton camera system. In the present study, we model a source-phantom-detector system using Geant4 and we develop a coincidence classification scheme that exploits the angular correlation of scattered annihilation quanta to improve the accuracy of coincidence detection. We find a [Formula: see text] image quality improvement in terms of the peak signal-to-noise ratio when scattered coincidence events are discriminated solely by their angular correlation, thus demonstrating the feasibility of this novel classification scheme. By integrating scatter events (both single-single and single-only) with unscattered coincidence events discriminated using conventional methods, our results suggest that Compton-PET may be a promising candidate for optimal emission tomographic imaging.

  4. Polarisation-based coincidence event discrimination: an in silico study towards a feasible scheme for Compton-PET

    NASA Astrophysics Data System (ADS)

    Toghyani, M.; Gillam, J. E.; McNamara, A. L.; Kuncic, Z.

    2016-08-01

    Current positron emission tomography (PET) systems use temporally localised coincidence events discriminated by energy and time-of-flight information. The two annihilation photons are in an entangled polarisation state and, in principle, additional information from the polarisation correlation of photon pairs could be used to improve the accuracy of coincidence classification. In a previous study, we demonstrated that in principle, the polarisation correlation information could be transferred to an angular correlation in the distribution of scattered photon pairs in a planar Compton camera system. In the present study, we model a source-phantom-detector system using Geant4 and we develop a coincidence classification scheme that exploits the angular correlation of scattered annihilation quanta to improve the accuracy of coincidence detection. We find a 22% image quality improvement in terms of the peak signal-to-noise ratio when scattered coincidence events are discriminated solely by their angular correlation, thus demonstrating the feasibility of this novel classification scheme. By integrating scatter events (both single-single and single-only) with unscattered coincidence events discriminated using conventional methods, our results suggest that Compton-PET may be a promising candidate for optimal emission tomographic imaging.

  5. Pet Allergy Quiz

    MedlinePlus

    ... term treatment for pet allergies. True False False: Allergy shots therapy (immunotherapy) has a proven track record as an effective form of long term treatment. Talk to your allergist / immunologist about whether this treatment approach is right for you. ... Utility navigation Donate ...

  6. Pets and Parenting.

    ERIC Educational Resources Information Center

    Mullis, Ann K.; And Others

    1987-01-01

    The authors describe a method for teaching parenting skills and helping students decide whether they want children by having them adopt a puppy or kitten for a 6-10 week period. They discuss how to use the pet adoption project in a family life education unit. (CH)

  7. Universal ICT Picosecond Camera

    NASA Astrophysics Data System (ADS)

    Lebedev, Vitaly B.; Syrtzev, V. N.; Tolmachyov, A. M.; Feldman, Gregory G.; Chernyshov, N. A.

    1989-06-01

    The paper reports on the design of an ICI camera operating in the mode of linear or three-frame image scan. The camera incorporates two tubes: time-analyzing ICI PIM-107 1 with cathode S-11, and brightness amplifier PMU-2V (gain about 104) for the image shaped by the first tube. The camera is designed on the basis of streak camera AGAT-SF3 2 with almost the same power sources, but substantially modified pulse electronics. Schematically, the design of tube PIM-107 is depicted in the figure. The tube consists of cermet housing 1, photocathode 2 made in a separate vacuum volume and introduced into the housing by means of a manipulator. In a direct vicinity of the photocathode, accelerating electrode is located made of a fine-structure grid. An electrostatic lens formed by focusing electrode 4 and anode diaphragm 5 produces a beam of electrons with a "remote crossover". The authors have suggested this term for an electron beam whose crossover is 40 to 60 mm away from the anode diaphragm plane which guarantees high sensitivity of scan plates 6 with respect to multiaperture framing diaphragm 7. Beyond every diaphragm aperture, a pair of deflecting plates 8 is found shielded from compensation plates 10 by diaphragm 9. The electronic image produced by the photocathode is focused on luminescent screen 11. The tube is controlled with the help of two saw-tooth voltages applied in antiphase across plates 6 and 10. Plates 6 serve for sweeping the electron beam over the surface of diaphragm 7. The beam is either allowed toward the screen, or delayed by the diaphragm walls. In such a manner, three frames are obtained, the number corresponding to that of the diaphragm apertures. Plates 10 serve for stopping the compensation of the image streak sweep on the screen. To avoid overlapping of frames, plates 8 receive static potentials responsible for shifting frames on the screen. Changing the potentials applied to plates 8, one can control the spacing between frames and partially or

  8. Neutron Imaging Camera

    NASA Technical Reports Server (NTRS)

    Hunter, Stanley; deNolfo, G. A.; Barbier, L. M.; Link, J. T.; Son, S.; Floyd, S. R.; Guardala, N.; Skopec, M.; Stark, B.

    2008-01-01

    The Neutron Imaging Camera (NIC) is based on the Three-dimensional Track Imager (3DTI) technology developed at GSFC for gamma-ray astrophysics applications. The 3-DTI, a large volume time-projection chamber, provides accurate, approximately 0.4 mm resolution, 3-D tracking of charged particles. The incident direction of fast neutrons, En > 0.5 MeV, are reconstructed from the momenta and energies of the proton and triton fragments resulting from (sup 3)He(n,p) (sup 3)H interactions in the 3-DTI volume. The performance of the NIC from laboratory and accelerator tests is presented.

  9. High-speed framing camera with an ellipsoidal scanner.

    PubMed

    Belinsky, A V; Plokhov, A V

    1995-01-01

    A new type of rotating-mirror framing-camera optical system is proposed. A study is reported of the feasibility of the use of an aspherical mirror, with its surface in the shape of a prolate ellipsoid of revolution, in the scanning system of the camera. Starting from the aberration minimization conditions, the optimization of the parameters of the optical system is carried out. An aspherical mirror of this kind performs not only the scanning function, but also acts as a condenser, thus greatly simplifying construction of the camera.

  10. Automatic inference of geometric camera parameters and inter-camera topology in uncalibrated disjoint surveillance cameras

    NASA Astrophysics Data System (ADS)

    den Hollander, Richard J. M.; Bouma, Henri; Baan, Jan; Eendebak, Pieter T.; van Rest, Jeroen H. C.

    2015-10-01

    Person tracking across non-overlapping cameras and other types of video analytics benefit from spatial calibration information that allows an estimation of the distance between cameras and a relation between pixel coordinates and world coordinates within a camera. In a large environment with many cameras, or for frequent ad-hoc deployments of cameras, the cost of this calibration is high. This creates a barrier for the use of video analytics. Automating the calibration allows for a short configuration time, and the use of video analytics in a wider range of scenarios, including ad-hoc crisis situations and large scale surveillance systems. We show an autocalibration method entirely based on pedestrian detections in surveillance video in multiple non-overlapping cameras. In this paper, we show the two main components of automatic calibration. The first shows the intra-camera geometry estimation that leads to an estimate of the tilt angle, focal length and camera height, which is important for the conversion from pixels to meters and vice versa. The second component shows the inter-camera topology inference that leads to an estimate of the distance between cameras, which is important for spatio-temporal analysis of multi-camera tracking. This paper describes each of these methods and provides results on realistic video data.

  11. 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.

  12. MR/PET or PET/MRI: does it matter?

    PubMed

    Beyer, Thomas; Moser, Ewald

    2013-02-01

    After the very successful clinical introduction of combined PET/CT imaging a decade ago, a hardware combination of PET and MR is following suit. Today, three different approaches towards integrated PET/MR have been proposed: (1) a triple-modality system with a 3T MRI and a time-of-flight PET/CT installed in adjacent rooms, (2) a tandem system with a 3T MRI and a time-of-flight PET/CT in a co-planar installation with a joint patient handling system, and (3) a fully-integrated system with a whole-body PET system mounted inside a 3T MRI system. This special issue of MAGMA brings together contributions from key experts in the field of PET/MR, PET/CT and CT. The various papers share the author's perspectives on the state-of-the-art PET/MR imaging with any of the three approaches mentioned above. In addition to several reviews discussing advantages and challenges of combining PET and MRI for clinical diagnostics, first clinical data are also presented. We expect this special issue to nurture future improvements in hardware, clinical protocols, and efficient post-processing strategies to further assess the diagnostic value of combined PET/MR imaging. It remains to be seen whether a so-called "killer application" for PET/MRI will surface. In that case PET/MR is likely to excel in pre-clinical and selected research applications for now. This special issue helps the readers to stay on track of this exciting development.

  13. Mars Science Laboratory Engineering Cameras

    NASA Technical Reports Server (NTRS)

    Maki, Justin N.; Thiessen, David L.; Pourangi, Ali M.; Kobzeff, Peter A.; Lee, Steven W.; Dingizian, Arsham; Schwochert, Mark A.

    2012-01-01

    NASA's Mars Science Laboratory (MSL) Rover, which launched to Mars in 2011, is equipped with a set of 12 engineering cameras. These cameras are build-to-print copies of the Mars Exploration Rover (MER) cameras, which were sent to Mars in 2003. The engineering cameras weigh less than 300 grams each and use less than 3 W of power. Images returned from the engineering cameras are used to navigate the rover on the Martian surface, deploy the rover robotic arm, and ingest samples into the rover sample processing system. The navigation cameras (Navcams) are mounted to a pan/tilt mast and have a 45-degree square field of view (FOV) with a pixel scale of 0.82 mrad/pixel. The hazard avoidance cameras (Haz - cams) are body-mounted to the rover chassis in the front and rear of the vehicle and have a 124-degree square FOV with a pixel scale of 2.1 mrad/pixel. All of the cameras utilize a frame-transfer CCD (charge-coupled device) with a 1024x1024 imaging region and red/near IR bandpass filters centered at 650 nm. The MSL engineering cameras are grouped into two sets of six: one set of cameras is connected to rover computer A and the other set is connected to rover computer B. The MSL rover carries 8 Hazcams and 4 Navcams.

  14. Stereoscopic camera design

    NASA Astrophysics Data System (ADS)

    Montgomery, David J.; Jones, Christopher K.; Stewart, James N.; Smith, Alan

    2002-05-01

    It is clear from the literature that the majority of work in stereoscopic imaging is directed towards the development of modern stereoscopic displays. As costs come down, wider public interest in this technology is expected to increase. This new technology would require new methods of image formation. Advances in stereo computer graphics will of course lead to the creation of new stereo computer games, graphics in films etc. However, the consumer would also like to see real-world stereoscopic images, pictures of family, holiday snaps etc. Such scenery would have wide ranges of depth to accommodate and would need also to cope with moving objects, such as cars, and in particular other people. Thus, the consumer acceptance of auto/stereoscopic displays and 3D in general would be greatly enhanced by the existence of a quality stereoscopic camera. This paper will cover an analysis of existing stereoscopic camera designs and show that they can be categorized into four different types, with inherent advantages and disadvantages. A recommendation is then made with regard to 3D consumer still and video photography. The paper will go on to discuss this recommendation and describe its advantages and how it can be realized in practice.

  15. NFC - Narrow Field Camera

    NASA Astrophysics Data System (ADS)

    Koukal, J.; Srba, J.; Gorková, S.

    2015-01-01

    We have been introducing a low-cost CCTV video system for faint meteor monitoring and here we describe the first results from 5 months of two-station operations. Our system called NFC (Narrow Field Camera) with a meteor limiting magnitude around +6.5mag allows research on trajectories of less massive meteoroids within individual parent meteor showers and the sporadic background. At present 4 stations (2 pairs with coordinated fields of view) of NFC system are operated in the frame of CEMeNt (Central European Meteor Network). The heart of each NFC station is a sensitive CCTV camera Watec 902 H2 and a fast cinematographic lens Meopta Meostigmat 1/50 - 52.5 mm (50 mm focal length and fixed aperture f/1.0). In this paper we present the first results based on 1595 individual meteors, 368 of which were recorded from two stations simultaneously. This data set allows the first empirical verification of theoretical assumptions for NFC system capabilities (stellar and meteor magnitude limit, meteor apparent brightness distribution and accuracy of single station measurements) and the first low mass meteoroid trajectory calculations. Our experimental data clearly showed the capabilities of the proposed system for low mass meteor registration and for calculations based on NFC data to lead to a significant refinement in the orbital elements for low mass meteoroids.

  16. HONEY -- The Honeywell Camera

    NASA Astrophysics Data System (ADS)

    Clayton, C. A.; Wilkins, T. N.

    The Honeywell model 3000 colour graphic recorder system (hereafter referred to simply as Honeywell) has been bought by Starlink for producing publishable quality photographic hardcopy from the IKON image displays. Full colour and black & white images can be recorded on positive or negative 35mm film. The Honeywell consists of a built-in high resolution flat-faced monochrome video monitor, a red/green/blue colour filter mechanism and a 35mm camera. The device works on the direct video signals from the IKON. This means that changing the brightness or contrast on the IKON monitor will not affect any photographs that you take. The video signals from the IKON consist of separate red, green and blue signals. When you take a picture, the Honeywell takes the red, green and blue signals in turn and displays three pictures consecutively on its internal monitor. It takes an exposure through each of three filters (red, green and blue) onto the film in the camera. This builds up the complete colour picture on the film. Honeywell systems are installed at nine Starlink sites, namely Belfast (locally funded), Birmingham, Cambridge, Durham, Leicester, Manchester, Rutherford, ROE and UCL.

  17. Talking with Children about Furry Classroom Pets.

    ERIC Educational Resources Information Center

    Texas Child Care, 1994

    1994-01-01

    Notes that rodents and rabbits share many characteristics that make them suitable classroom pets and gives background information on rabbits, guinea pigs, hamsters, and gerbils. Offers advice on buying a classroom pet, the pet's home, feeding, helping the children handle the pet, and pet health and family planning. (TJQ)

  18. Cloud Computing with Context Cameras

    NASA Astrophysics Data System (ADS)

    Pickles, A. J.; Rosing, W. E.

    2016-05-01

    We summarize methods and plans to monitor and calibrate photometric observations with our autonomous, robotic network of 2m, 1m and 40cm telescopes. These are sited globally to optimize our ability to observe time-variable sources. Wide field "context" cameras are aligned with our network telescopes and cycle every ˜2 minutes through BVr'i'z' filters, spanning our optical range. We measure instantaneous zero-point offsets and transparency (throughput) against calibrators in the 5-12m range from the all-sky Tycho2 catalog, and periodically against primary standards. Similar measurements are made for all our science images, with typical fields of view of ˜0.5 degrees. These are matched against Landolt, Stetson and Sloan standards, and against calibrators in the 10-17m range from the all-sky APASS catalog. Such measurements provide pretty good instantaneous flux calibration, often to better than 5%, even in cloudy conditions. Zero-point and transparency measurements can be used to characterize, monitor and inter-compare sites and equipment. When accurate calibrations of Target against Standard fields are required, monitoring measurements can be used to select truly photometric periods when accurate calibrations can be automatically scheduled and performed.

  19. Neutron Imaging Camera

    NASA Technical Reports Server (NTRS)

    Hunter, Stanley D.; DeNolfo, Georgia; Floyd, Sam; Krizmanic, John; Link, Jason; Son, Seunghee; Guardala, Noel; Skopec, Marlene; Stark, Robert

    2008-01-01

    We describe the Neutron Imaging Camera (NIC) being developed for DTRA applications by NASA/GSFC and NSWC/Carderock. The NIC is based on the Three-dimensional Track Imager (3-DTI) technology developed at GSFC for gamma-ray astrophysics applications. The 3-DTI, a large volume time-projection chamber, provides accurate, approximately 0.4 mm resolution. 3-D tracking of charged particles. The incident direction of fast neutrons, E(sub N) > 0.5 MeV. arc reconstructed from the momenta and energies of the proton and triton fragments resulting from 3He(n,p)3H interactions in the 3-DTI volume. We present angular and energy resolution performance of the NIC derived from accelerator tests.

  20. FDG-PET Contributions to the Pathophysiology of Memory Impairment.

    PubMed

    Segobin, Shailendra; La Joie, Renaud; Ritz, Ludivine; Beaunieux, Hélène; Desgranges, Béatrice; Chételat, Gaël; Pitel, Anne Lise; Eustache, Francis

    2015-09-01

    Measurement of synaptic activity by Positron Emission Tomography (PET) and its relation to cognitive functions such as episodic memory, working memory and executive functions in healthy humans and patients with neurocognitive disorders have been well documented. In this review, we introduce the concept of PET imaging that allows the observation of a particular biological process in vivo through the use of radio-labelled compounds, its general use to the medical world and its contributions to the understanding of memory systems. We then focus on [(18)F]-2-fluoro-2-deoxy-D-glucose (FDG-PET), the radiotracer that is used to measure local cerebral metabolic rate of glucose that is indicative of synaptic activity in the brain. FDG-PET at rest has been at the forefront of functional neuroimaging over the past 3 decades, contributing to the understanding of cognitive functions in healthy humans and how these functional patterns change with cognitive alterations. We discuss methodological considerations that are important for optimizing FDG-PET imaging data prior to analysis. We then highlight the contribution of FDG-PET to the understanding of the patterns of functional differences in non-degenerative pathologies, normal ageing, and age-related neurodegenerative disorders. Through reasonable temporal and spatial resolution, its ability to measure synaptic activity in the whole brain, independently of any specific network and disease, makes it ideal to observe regional functional changes associated with memory impairment.

  1. Newer PET application with an old tracer: role of 18F-NaF skeletal PET/CT in oncologic practice.

    PubMed

    Bastawrous, Sarah; Bhargava, Puneet; Behnia, Fatemeh; Djang, David S W; Haseley, David R

    2014-01-01

    The skeleton is one of the most common sites for metastatic disease, particularly from breast and prostate cancer. Bone metastases are associated with considerable morbidity, and accurate imaging of the skeleton is important in determining the appropriate therapeutic plan. Sodium fluoride labeled with fluorine 18 (sodium fluoride F 18 [(18)F-NaF]) is a positron-emitting radiopharmaceutical first introduced several decades ago for skeletal imaging. (18)F-NaF was approved for clinical use as a positron emission tomographic (PET) agent by the U.S. Food and Drug Administration in 1972. The early use of this agent was limited, given the difficulties of imaging its high-energy photons on the available gamma cameras. For skeletal imaging, it was eventually replaced by technetium 99m ((99m)Tc)-labeled agents because of the technical limitations of (18)F-NaF. During the past several years, the widespread availability and implementation of hybrid PET and computed tomographic (CT) dual-modality systems (PET/CT) have encouraged a renewed interest in (18)F-NaF PET/CT for routine clinical use in bone imaging. Because current PET/CT systems offer high sensitivity and spatial resolution, the use of (18)F-NaF has been reevaluated for the detection of malignant and nonmalignant osseous disease. Growing evidence suggests that (18)F-NaF PET/CT provides increased sensitivity and specificity in the detection of bone metastases. Furthermore, the favorable pharmacokinetics of (18)F-NaF, combined with the superior imaging characteristics of PET/CT, supports the routine clinical use of (18)F-NaF PET/CT for oncologic imaging for skeletal metastases. In this article, a review of the indications, imaging appearances, and utility of (18)F-NaF PET/CT in the evaluation of skeletal disease is provided, with an emphasis on oncologic imaging.

  2. Multimodality tomographic scintimammography with PET, PECI, and SPECT: initial evaluation

    NASA Astrophysics Data System (ADS)

    Krol, Andrzej; Feiglin, David H.; Thomas, Frank D.; Hellwig, Bradford J.; Gagne, George M.

    2002-04-01

    We compared tomographic scintimammography performed using single photon emission computed tomography (SPECT), positron emission coincidence imaging (PECI) and positron emission tomography (PET). A female thorax phantom was used. Activities of the myocardium, thorax and breasts were adjusted to emulate the count rate observed with patients. Hollow plastic spheres, imitating hot lesions (1.5-20ml), filled with radioactive saline were inserted in the center of each breast. Specific activities of internal organs were adjusted to emulate the count rate observed with patients. SPECT data were acquired with Tc-99m using gamma cameras with NaI(Tl) detectors. A modified FBP (CODE) reconstruction algorithm was used to render SPECT tomographic images. PECI (Siemens E.CAM with NaI(Tl)) and PET (GE Advance with BGO) data were acquired using F-18 FDG. Vendor supplied reconstruction algorithms were used. The reconstructed hot lesions contrast and resolution were investigated. Image quality obtained can be ranked as follows: (1) PET(BGO), (2) PECI(NaI), (3) SPECT(NaI) In conclusion, assuming comparable uptake values of Tc-99m-sestamibi and F-18 FDG, PET seems to be a superior methodology in visualization of breast lesion as compared to SPECT and PECI. All these tomographic methods appear to be promising adjunct to x-ray mammography in difficult to interpret cases.

  3. Evaluation of a video-based head motion tracking system for dedicated brain PET

    NASA Astrophysics Data System (ADS)

    Anishchenko, S.; Beylin, D.; Stepanov, P.; Stepanov, A.; Weinberg, I. N.; Schaeffer, S.; Zavarzin, V.; Shaposhnikov, D.; Smith, M. F.

    2015-03-01

    Unintentional head motion during Positron Emission Tomography (PET) data acquisition can degrade PET image quality and lead to artifacts. Poor patient compliance, head tremor, and coughing are examples of movement sources. Head motion due to patient non-compliance can be an issue with the rise of amyloid brain PET in dementia patients. To preserve PET image resolution and quantitative accuracy, head motion can be tracked and corrected in the image reconstruction algorithm. While fiducial markers can be used, a contactless approach is preferable. A video-based head motion tracking system for a dedicated portable brain PET scanner was developed. Four wide-angle cameras organized in two stereo pairs are used for capturing video of the patient's head during the PET data acquisition. Facial points are automatically tracked and used to determine the six degree of freedom head pose as a function of time. The presented work evaluated the newly designed tracking system using a head phantom and a moving American College of Radiology (ACR) phantom. The mean video-tracking error was 0.99±0.90 mm relative to the magnetic tracking device used as ground truth. Qualitative evaluation with the ACR phantom shows the advantage of the motion tracking application. The developed system is able to perform tracking with accuracy close to millimeter and can help to preserve resolution of brain PET images in presence of movements.

  4. Recent Advances and Future Advances in Time-of-Flight PET

    PubMed Central

    Moses, William W.

    2007-01-01

    Simple theory predicts that the statistical noise variance in PET can be reduced by an order of magnitude by using time-of-flight (TOF) information. This reduction can be obtained by improving the coincidence timing resolution, and so would be achievable in clinical, whole body studies using with PET systems that differ little from existing cameras. The potential impact of this development is large, especially for oncology studies in large patients, where it is sorely needed. TOF PET was extensively studied in the 1980’s but died away in the 1990’s, as it was impossible to reliably achieve sufficient timing resolution without sacrificing other important PET performance aspects, such as spatial resolution and efficiency. Recent advances in technology (scintillators, photodetectors, and high speed electronics) have renewed interest in TOF PET, which is experiencing a rebirth. However, there is still much to be done, both in instrumentation development and evaluating the true benefits of TOF in modern clinical PET. This paper looks at what has been accomplished and what needs to be done before time-of-flight PET can reach its full potential. PMID:18836513

  5. Whole blood glucose analysis based on smartphone camera module

    NASA Astrophysics Data System (ADS)

    Devadhasan, Jasmine Pramila; Oh, Hyunhee; Choi, Cheol Soo; Kim, Sanghyo

    2015-11-01

    Complementary metal oxide semiconductor (CMOS) image sensors have received great attention for their high efficiency in biological applications. The present work describes a CMOS image sensor-based whole blood glucose monitoring system through a point-of-care (POC) approach. A simple poly-ethylene terephthalate (PET) chip was developed to carry out the enzyme kinetic reaction at various concentrations (110-586 mg/dL) of mouse blood glucose. In this technique, assay reagent is immobilized onto amine functionalized silica (AFSiO2) nanoparticles as an electrostatic attraction in order to achieve glucose oxidation on the chip. The assay reagent immobilized AFSiO2 nanoparticles develop a semi-transparent reaction platform, which is technically a suitable chip to analyze by a camera module. The oxidized glucose then produces a green color according to the glucose concentration and is analyzed by the camera module as a photon detection technique; the photon number decreases when the glucose concentration increases. The combination of these components, the CMOS image sensor and enzyme immobilized PET film chip, constitute a compact, accurate, inexpensive, precise, digital, highly sensitive, specific, and optical glucose-sensing approach for POC diagnosis.

  6. Extended suicide with a pet.

    PubMed

    Cooke, Brian K

    2013-01-01

    The combination of the killing of a pet and a suicide is a perplexing scenario that is largely unexplored in the literature. Many forensic psychiatrists and psychologists may be unaccustomed to considering the significance of the killing of a pet. The subject is important, however, because many people regard their pets as members of their family. A case is presented of a woman who killed her pet dog and herself by carbon monoxide poisoning. The purpose of this article is to provide an initial exploration of the topic of extended suicide with a pet. Forensic mental health evaluations may have a role in understanding the etiology of this event and in opining as to the culpability of individuals who attempt to or successfully kill a pet and then commit suicide. Because the scientific literature is lacking, there is a need to understand this act from a variety of perspectives. First, a social and anthropological perspective will be presented that summarizes the history of the practice of killing of one's pet, with a focus on the ancient Egyptians. A clinical context will examine what relationship animals have to mental illness. A vast body of existing scientific data showing the relevance of human attachment to pets suggests that conclusions from the phenomena of homicide-suicide and filicide-suicide are applicable to extended suicide with a pet. Finally, recommendations will be proposed for both clinical and forensic psychiatrists faced with similar cases.

  7. A generalized reconstruction framework for unconventional PET systems

    PubMed Central

    Mathews, Aswin John; Li, Ke; Komarov, Sergey; Wang, Qiang; Ravindranath, Bosky; O’Sullivan, Joseph A.; Tai, Yuan-Chuan

    2015-01-01

    Purpose: Quantitative estimation of the radionuclide activity concentration in positron emission tomography (PET) requires precise modeling of PET physics. The authors are focused on designing unconventional PET geometries for specific applications. This work reports the creation of a generalized reconstruction framework, capable of reconstructing tomographic PET data for systems that use right cuboidal detector elements positioned at arbitrary geometry using a regular Cartesian grid of image voxels. Methods: The authors report on a variety of design choices and optimization for the creation of the generalized framework. The image reconstruction algorithm is maximum likelihood-expectation–maximization. System geometry can be specified using a simple script. Given the geometry, a symmetry seeking algorithm finds existing symmetry in the geometry with respect to the image grid to improve the memory usage/speed. Normalization is approached from a geometry independent perspective. The system matrix is computed using the Siddon’s algorithm and subcrystal approach. The program is parallelized through open multiprocessing and message passing interface libraries. A wide variety of systems can be modeled using the framework. This is made possible by modeling the underlying physics and data correction, while generalizing the geometry dependent features. Results: Application of the framework for three novel PET systems, each designed for a specific application, is presented to demonstrate the robustness of the framework in modeling PET systems of unconventional geometry. Three PET systems of unconventional geometry are studied. (1) Virtual-pinhole half-ring insert integrated into Biograph-40: although the insert device improves image quality over conventional whole-body scanner, the image quality varies depending on the position of the insert and the object. (2) Virtual-pinhole flat-panel insert integrated into Biograph-40: preliminary results from an investigation into a

  8. A detector head design for small-animal PET with silicon photomultipliers (SiPM).

    PubMed

    Moehrs, Sascha; Del Guerra, Alberto; Herbert, Deborah J; Mandelkern, Mark A

    2006-03-07

    Small-animal PET systems are now striving for sub-millimetre resolution. Current systems based upon PSPMTs and finely pixellated scintillators can be pushed to higher resolution, but at the expense of other performance parameters and a rapidly escalating cost. Moreover, depth of interaction (DOI) information is usually difficult to assess in such systems, even though this information is highly desirable to reduce the parallax error, which is often the dominant error for such high-resolution systems. In this study we propose a high-resolution detector head for a small-animal PET imaging system with intrinsic DOI information. Instead of a pixellated scintillator, our design is based upon the classic Anger camera principle, i.e. the head is constructed of modular layers each consisting of a continuous slab of scintillator, viewed by a new type of compact silicon photodetector. The photodetector is the recently developed silicon photomultiplier (SiPM) that as well as being very compact has many other attractive properties: high gain at low bias voltage, excellent single-photoelectron resolution and fast timing. A detector head of about 4 x 4 cm2 in area is proposed, constructed from three modular layers of the type described above. We perform a simulation study, using the Monte Carlo simulation package Geant4. The simulation results are used to optimize the geometry of the detector head and characterize its performance. Additionally, hit estimation algorithms are studied to determine the interaction position of annihilation photons correctly over the whole detector surface. The resulting detector has a nearly uniform efficiency for 511 keV photons of approximately 70% and an intrinsic spatial resolution of less than approximately 0.4 mm full width at half maximum (fwhm).

  9. A cooperative control algorithm for camera based observational systems.

    SciTech Connect

    Young, Joseph G.

    2012-01-01

    Over the last several years, there has been considerable growth in camera based observation systems for a variety of safety, scientific, and recreational applications. In order to improve the effectiveness of these systems, we frequently desire the ability to increase the number of observed objects, but solving this problem is not as simple as adding more cameras. Quite often, there are economic or physical restrictions that prevent us from adding additional cameras to the system. As a result, we require methods that coordinate the tracking of objects between multiple cameras in an optimal way. In order to accomplish this goal, we present a new cooperative control algorithm for a camera based observational system. Specifically, we present a receding horizon control where we model the underlying optimal control problem as a mixed integer linear program. The benefit of this design is that we can coordinate the actions between each camera while simultaneously respecting its kinematics. In addition, we further improve the quality of our solution by coupling our algorithm with a Kalman filter. Through this integration, we not only add a predictive component to our control, but we use the uncertainty estimates provided by the filter to encourage the system to periodically observe any outliers in the observed area. This combined approach allows us to intelligently observe the entire region of interest in an effective and thorough manner.

  10. Mars Exploration Rover engineering cameras

    USGS Publications Warehouse

    Maki, J.N.; Bell, J.F.; Herkenhoff, K. E.; Squyres, S. W.; Kiely, A.; Klimesh, M.; Schwochert, M.; Litwin, T.; Willson, R.; Johnson, Aaron H.; Maimone, M.; Baumgartner, E.; Collins, A.; Wadsworth, M.; Elliot, S.T.; Dingizian, A.; Brown, D.; Hagerott, E.C.; Scherr, L.; Deen, R.; Alexander, D.; Lorre, J.

    2003-01-01

    NASA's Mars Exploration Rover (MER) Mission will place a total of 20 cameras (10 per rover) onto the surface of Mars in early 2004. Fourteen of the 20 cameras are designated as engineering cameras and will support the operation of the vehicles on the Martian surface. Images returned from the engineering cameras will also be of significant importance to the scientific community for investigative studies of rock and soil morphology. The Navigation cameras (Navcams, two per rover) are a mast-mounted stereo pair each with a 45?? square field of view (FOV) and an angular resolution of 0.82 milliradians per pixel (mrad/pixel). The Hazard Avoidance cameras (Hazcams, four per rover) are a body-mounted, front- and rear-facing set of stereo pairs, each with a 124?? square FOV and an angular resolution of 2.1 mrad/pixel. The Descent camera (one per rover), mounted to the lander, has a 45?? square FOV and will return images with spatial resolutions of ???4 m/pixel. All of the engineering cameras utilize broadband visible filters and 1024 x 1024 pixel detectors. Copyright 2003 by the American Geophysical Union.

  11. Camera artifacts in IUE spectra

    NASA Technical Reports Server (NTRS)

    Bruegman, O. W.; Crenshaw, D. M.

    1994-01-01

    This study of emission line mimicking features in the IUE cameras has produced an atlas of artifiacts in high-dispersion images with an accompanying table of prominent artifacts and a table of prominent artifacts in the raw images along with a medium image of the sky background for each IUE camera.

  12. The "All Sky Camera Network"

    ERIC Educational Resources Information Center

    Caldwell, Andy

    2005-01-01

    In 2001, the "All Sky Camera Network" came to life as an outreach program to connect the Denver Museum of Nature and Science (DMNS) exhibit "Space Odyssey" with Colorado schools. The network is comprised of cameras placed strategically at schools throughout Colorado to capture fireballs--rare events that produce meteorites.…

  13. SEOS frame camera applications study

    NASA Technical Reports Server (NTRS)

    1974-01-01

    A research and development satellite is discussed which will provide opportunities for observation of transient phenomena that fall within the fixed viewing circle of the spacecraft. The evaluation of possible applications for frame cameras, for SEOS, are studied. The computed lens characteristics for each camera are listed.

  14. Radiation camera motion correction system

    DOEpatents

    Hoffer, P.B.

    1973-12-18

    The device determines the ratio of the intensity of radiation received by a radiation camera from two separate portions of the object. A correction signal is developed to maintain this ratio at a substantially constant value and this correction signal is combined with the camera signal to correct for object motion. (Official Gazette)

  15. Compact and robust hyperspectral camera based on compressed sensing

    NASA Astrophysics Data System (ADS)

    Žídek, K.; Denk, O.; Hlubuček, J.; Václavík, J.

    2016-11-01

    Spectrum of light which is emitted or reflected by an object carries immense amount of information about the object. A simple piece of evidence is the importance of color sensing for human vision. Combining an image acquisition with efficient measurement of light spectra for each detected pixel is therefore one of the important issues in imaging, referred as hyperspectral imaging. We demonstrate a construction of a compact and robust hyperspectral camera for the visible and near-IR spectral region. The camera was designed vastly based on off-shelf optics, yet an extensive optimization and addition of three customized parts enabled construction of the camera featuring a low f-number (F/3.9) and fully concentric optics. We employ a novel approach of compressed sensing (namely coded aperture snapshot spectral imaging, abbrev. CASSI). The compressed sensing enables to computationally extract an encoded hyperspectral information from a single camera exposition. Owing to the technique the camera lacks any moving or scanning part, while it can record the full image and spectral information in a single snapshot. Moreover, unlike the commonly used compressed sensing table-top apparatuses, the camera represents a portable device able to work outside a lab. We demonstrate the spectro-temporal reconstruction of recorded scenes based on 90×90 random matrix encoding. Finally, we discuss potential of the compressed sensing in hyperspectral camera.

  16. An autonomous sensor module based on a legacy CCTV camera

    NASA Astrophysics Data System (ADS)

    Kent, P. J.; Faulkner, D. A. A.; Marshall, G. F.

    2016-10-01

    A UK MoD funded programme into autonomous sensors arrays (SAPIENT) has been developing new, highly capable sensor modules together with a scalable modular architecture for control and communication. As part of this system there is a desire to also utilise existing legacy sensors. The paper reports upon the development of a SAPIENT-compliant sensor module using a legacy Close-Circuit Television (CCTV) pan-tilt-zoom (PTZ) camera. The PTZ camera sensor provides three modes of operation. In the first mode, the camera is automatically slewed to acquire imagery of a specified scene area, e.g. to provide "eyes-on" confirmation for a human operator or for forensic purposes. In the second mode, the camera is directed to monitor an area of interest, with zoom level automatically optimized for human detection at the appropriate range. Open source algorithms (using OpenCV) are used to automatically detect pedestrians; their real world positions are estimated and communicated back to the SAPIENT central fusion system. In the third mode of operation a "follow" mode is implemented where the camera maintains the detected person within the camera field-of-view without requiring an end-user to directly control the camera with a joystick.

  17. Innovative LuYAP:Ce array for PET imaging

    NASA Astrophysics Data System (ADS)

    Cinti, M. N.; Scafe, R.; Bennati, P.; Lo Meo, S.; Frantellizzi, V.; Pellegrini, R.; De Vincentis, G.; Sacco, D.; Fabbri, A.; Pani, R.

    2017-03-01

    We present an imaging characterization of a 10 × 10 LuYAP array (2 × 2 × 10 mm3 pixels) with an innovative dielectric coating insulation (0.015 mm thick), in view of its possible use in a gamma camera for imaging positron emission tomography (PET) or in similar applications, e.g. as γ -prompt detector in hadron therapy. The particular assembly of this array was realized in order to obtain a packing fraction of 98%, improving detection efficiency and light collection. For imaging purpose, the array has been coupled with a selected Hamamatsu H10966-100 Multi Anode Photomultiplier read out by a customized 64 independent channels electronics. This tube presents a superbialkali photocathode with 38% of quantum efficiency, permitting to enhance energy resolution and consequently image quality. A pixel identification of about 0.5 mm at 662 keV was obtained, highlighting the potentiality of this detector in PET applications.

  18. Coherent infrared imaging camera (CIRIC)

    SciTech Connect

    Hutchinson, D.P.; Simpson, M.L.; Bennett, C.A.; Richards, R.K.; Emery, M.S.; Crutcher, R.I.; Sitter, D.N. Jr.; Wachter, E.A.; Huston, M.A.

    1995-07-01

    New developments in 2-D, wide-bandwidth HgCdTe (MCT) and GaAs quantum-well infrared photodetectors (QWIP) coupled with Monolithic Microwave Integrated Circuit (MMIC) technology are now making focal plane array coherent infrared (IR) cameras viable. Unlike conventional IR cameras which provide only thermal data about a scene or target, a coherent camera based on optical heterodyne interferometry will also provide spectral and range information. Each pixel of the camera, consisting of a single photo-sensitive heterodyne mixer followed by an intermediate frequency amplifier and illuminated by a separate local oscillator beam, constitutes a complete optical heterodyne receiver. Applications of coherent IR cameras are numerous and include target surveillance, range detection, chemical plume evolution, monitoring stack plume emissions, and wind shear detection.

  19. 3D Scene Restoration Using One Active PTZ Camera

    NASA Astrophysics Data System (ADS)

    Alexiev, K. M.; Nikolova, I. N.; Zapryanov, G. S.

    2009-10-01

    The paper considers the task of recovery of 3D information about the scene from single camera images. The basic idea is to extract the useful depth information from the images automatically and efficiently. Depth perception with single standard video surveillance camera is a challenging problem. The difficulties in deriving the distance to the observed objects in the scene can be partially overcome using active PTZ cameras and suitable control of camera parameters. There are several techniques for depth recovery. Here, the task of depth estimation in the context of the well known depth from defocus approach is considered. In this paper, it is proposed the problem to be solved as classical nonlinear line fitting optimization problem. The characteristics of the approach are discussed. Experimental studies, using test patterns and real objects are presented.

  20. How long is enough to detect terrestrial animals? Estimating the minimum trapping effort on camera traps

    PubMed Central

    Si, Xingfeng; Kays, Roland

    2014-01-01

    Camera traps is an important wildlife inventory tool for estimating species diversity at a site. Knowing what minimum trapping effort is needed to detect target species is also important to designing efficient studies, considering both the number of camera locations, and survey length. Here, we take advantage of a two-year camera trapping dataset from a small (24-ha) study plot in Gutianshan National Nature Reserve, eastern China to estimate the minimum trapping effort actually needed to sample the wildlife community. We also evaluated the relative value of adding new camera sites or running cameras for a longer period at one site. The full dataset includes 1727 independent photographs captured during 13,824 camera days, documenting 10 resident terrestrial species of birds and mammals. Our rarefaction analysis shows that a minimum of 931 camera days would be needed to detect the resident species sufficiently in the plot, and c. 8700 camera days to detect all 10 resident species. In terms of detecting a diversity of species, the optimal sampling period for one camera site was c. 40, or long enough to record about 20 independent photographs. Our analysis of evaluating the increasing number of additional camera sites shows that rotating cameras to new sites would be more efficient for measuring species richness than leaving cameras at fewer sites for a longer period. PMID:24868493

  1. How long is enough to detect terrestrial animals? Estimating the minimum trapping effort on camera traps.

    PubMed

    Si, Xingfeng; Kays, Roland; Ding, Ping

    2014-01-01

    Camera traps is an important wildlife inventory tool for estimating species diversity at a site. Knowing what minimum trapping effort is needed to detect target species is also important to designing efficient studies, considering both the number of camera locations, and survey length. Here, we take advantage of a two-year camera trapping dataset from a small (24-ha) study plot in Gutianshan National Nature Reserve, eastern China to estimate the minimum trapping effort actually needed to sample the wildlife community. We also evaluated the relative value of adding new camera sites or running cameras for a longer period at one site. The full dataset includes 1727 independent photographs captured during 13,824 camera days, documenting 10 resident terrestrial species of birds and mammals. Our rarefaction analysis shows that a minimum of 931 camera days would be needed to detect the resident species sufficiently in the plot, and c. 8700 camera days to detect all 10 resident species. In terms of detecting a diversity of species, the optimal sampling period for one camera site was c. 40, or long enough to record about 20 independent photographs. Our analysis of evaluating the increasing number of additional camera sites shows that rotating cameras to new sites would be more efficient for measuring species richness than leaving cameras at fewer sites for a longer period.

  2. Camera sensitivity study

    NASA Astrophysics Data System (ADS)

    Schlueter, Jonathan; Murphey, Yi L.; Miller, John W. V.; Shridhar, Malayappan; Luo, Yun; Khairallah, Farid

    2004-12-01

    As the cost/performance Ratio of vision systems improves with time, new classes of applications become feasible. One such area, automotive applications, is currently being investigated. Applications include occupant detection, collision avoidance and lane tracking. Interest in occupant detection has been spurred by federal automotive safety rules in response to injuries and fatalities caused by deployment of occupant-side air bags. In principle, a vision system could control airbag deployment to prevent this type of mishap. Employing vision technology here, however, presents a variety of challenges, which include controlling costs, inability to control illumination, developing and training a reliable classification system and loss of performance due to production variations due to manufacturing tolerances and customer options. This paper describes the measures that have been developed to evaluate the sensitivity of an occupant detection system to these types of variations. Two procedures are described for evaluating how sensitive the classifier is to camera variations. The first procedure is based on classification accuracy while the second evaluates feature differences.

  3. Proportional counter radiation camera

    DOEpatents

    Borkowski, C.J.; Kopp, M.K.

    1974-01-15

    A gas-filled proportional counter camera that images photon emitting sources is described. A two-dimensional, positionsensitive proportional multiwire counter is provided as the detector. The counter consists of a high- voltage anode screen sandwiched between orthogonally disposed planar arrays of multiple parallel strung, resistively coupled cathode wires. Two terminals from each of the cathode arrays are connected to separate timing circuitry to obtain separate X and Y coordinate signal values from pulse shape measurements to define the position of an event within the counter arrays which may be recorded by various means for data display. The counter is further provided with a linear drift field which effectively enlarges the active gas volume of the counter and constrains the recoil electrons produced from ionizing radiation entering the counter to drift perpendicularly toward the planar detection arrays. A collimator is interposed between a subject to be imaged and the counter to transmit only the radiation from the subject which has a perpendicular trajectory with respect to the planar cathode arrays of the detector. (Official Gazette)

  4. Toward standardising gamma camera quality control procedures

    NASA Astrophysics Data System (ADS)

    Alkhorayef, M. A.; Alnaaimi, M. A.; Alduaij, M. A.; Mohamed, M. O.; Ibahim, S. Y.; Alkandari, F. A.; Bradley, D. A.

    2015-11-01

    Attaining high standards of efficiency and reliability in the practice of nuclear medicine requires appropriate quality control (QC) programs. For instance, the regular evaluation and comparison of extrinsic and intrinsic flood-field uniformity enables the quick correction of many gamma camera problems. Whereas QC tests for uniformity are usually performed by exposing the gamma camera crystal to a uniform flux of gamma radiation from a source of known activity, such protocols can vary significantly. Thus, there is a need for optimization and standardization, in part to allow direct comparison between gamma cameras from different vendors. In the present study, intrinsic uniformity was examined as a function of source distance, source activity, source volume and number of counts. The extrinsic uniformity and spatial resolution were also examined. Proper standard QC procedures need to be implemented because of the continual development of nuclear medicine imaging technology and the rapid expansion and increasing complexity of hybrid imaging system data. The present work seeks to promote a set of standard testing procedures to contribute to the delivery of safe and effective nuclear medicine services.

  5. MO-FG-207-01: Technological Advances and Challenges: Experience with the First Integrated Whole-Body PET/MRI

    SciTech Connect

    Laforest, R.

    2015-06-15

    The use of integrated PET/MRI systems in clinical applications can best benefit from understanding their technological advances and limitations. The currently available clinical PET/MRI systems have their own characteristics. Thorough analyses of existing technical data and evaluation of necessary performance metrics for quality assurances could be conducted to optimize application-specific PET/MRI protocols. This Symposium will focus on technical advances and limitations of clinical PET/MRI systems, and how this exciting imaging modality can be utilized in applications that can benefit from both PET and MRI. Learning Objectives: To understand the technological advances of clinical PET/MRI systems To correctly identify clinical applications that can benefit from PET/MRI To understand ongoing work to further improve the current PET/MRI technology Floris Jansen is a GE Healthcare employee.

  6. MO-FG-207-02: Technological Advances and Challenges: Experience with Time-Of-Flight PET Combined with 3-Tesla MRI

    SciTech Connect

    Jansen, F.

    2015-06-15

    The use of integrated PET/MRI systems in clinical applications can best benefit from understanding their technological advances and limitations. The currently available clinical PET/MRI systems have their own characteristics. Thorough analyses of existing technical data and evaluation of necessary performance metrics for quality assurances could be conducted to optimize application-specific PET/MRI protocols. This Symposium will focus on technical advances and limitations of clinical PET/MRI systems, and how this exciting imaging modality can be utilized in applications that can benefit from both PET and MRI. Learning Objectives: To understand the technological advances of clinical PET/MRI systems To correctly identify clinical applications that can benefit from PET/MRI To understand ongoing work to further improve the current PET/MRI technology Floris Jansen is a GE Healthcare employee.

  7. Auto-converging stereo cameras for 3D robotic tele-operation

    NASA Astrophysics Data System (ADS)

    Edmondson, Richard; Aycock, Todd; Chenault, David

    2012-06-01

    Polaris Sensor Technologies has developed a Stereovision Upgrade Kit for TALON robot to provide enhanced depth perception to the operator. This kit previously required the TALON Operator Control Unit to be equipped with the optional touchscreen interface to allow for operator control of the camera convergence angle adjustment. This adjustment allowed for optimal camera convergence independent of the distance from the camera to the object being viewed. Polaris has recently improved the performance of the stereo camera by implementing an Automatic Convergence algorithm in a field programmable gate array in the camera assembly. This algorithm uses scene content to automatically adjust the camera convergence angle, freeing the operator to focus on the task rather than adjustment of the vision system. The autoconvergence capability has been demonstrated on both visible zoom cameras and longwave infrared microbolometer stereo pairs.

  8. VIRUS-P: camera design and performance

    NASA Astrophysics Data System (ADS)

    Tufts, Joseph R.; MacQueen, Phillip J.; Smith, Michael P.; Segura, Pedro R.; Hill, Gary J.; Edmonston, Robert D.

    2008-07-01

    We present the design and performance of the prototype Visible Integral-field Replicable Unit Spectrograph (VIRUS-P) camera. Commissioned in 2007, VIRUS-P is the prototype for 150+ identical fiber-fed integral field spectrographs for the Hobby-Eberly Telescope Dark Energy Experiment. With minimal complexity, the gimbal mounted, double-Schmidt design achieves high on-sky throughput, image quality, contrast, and stability with novel optics, coatings, baffling, and minimization of obscuration. The system corrector working for both the collimator and f / 1.33 vacuum Schmidt camera serves as the cryostat window while a 49 mm square aspheric field flattener sets the central obscuration. The mount, electronics, and cooling of the 2k × 2k, Fairchild Imaging CCD3041-BI fit in the field-flattener footprint. Ultra-black knife edge baffles at the corrector, spider, and adjustable mirror, and a detector mask, match the optical footprints at each location and help maximize the 94% contrast between 245 spectra. An optimally stiff and light symmetric four vane stainless steel spider supports the CCD which is thermally isolated with an equally stiff Ultem-1000 structure. The detector/field flattener spacing is maintained to 1 μm for all camera orientations and repeatably reassembled to 12 μm. Invar rods in tension hold the camera focus to +/-4 μm over a -5-25 °C temperature range. Delivering a read noise of 4.2 e- RMS, sCTE of 1-10-5 , and pCTE of 1-10-6 at 100 kpix/s, the McDonald V2 controller also helps to achieve a 38 hr hold time with 3 L of LN2 while maintaining the detector temperature setpoint to 150 μK (5σ RMS).

  9. Supplements for exotic pets.

    PubMed

    Mejia-Fava, Johanna; Colitz, Carmen M H

    2014-09-01

    The use of supplements has become commonplace in an effort to complement traditional therapy and as part of long-term preventive health plans. This article discusses historical and present uses of antioxidants, vitamins, and herbs. By complementing traditional medicine with holistic and alternative nutrition and supplements, the overall health and wellness of exotic pets can be enhanced and balanced. Further research is needed for understanding the strengths and uses of supplements in exotic species. Going back to the animals' origin and roots bring clinicians closer to nature and its healing powers.

  10. Dark energy survey and camera

    SciTech Connect

    William Wester

    2004-08-16

    The authors describe the Dark Energy Survey and Camera. The survey will image 5000 sq. deg. in the southern sky to collect 300 million galaxies, 30,000 galaxy clusters and 2000 Type Ia supernovae. They expect to derive a value for the dark energy equation of state parameters, w, to a precision of 5% by combining four distinct measurement techniques. They describe the mosaic camera that will consist of CCDs with enhanced sensitivity in the near infrared. The camera will be mounted at the prime focus of the 4m Blanco telescope.

  11. Vision Sensors and Cameras

    NASA Astrophysics Data System (ADS)

    Hoefflinger, Bernd

    Silicon charge-coupled-device (CCD) imagers have been and are a specialty market ruled by a few companies for decades. Based on CMOS technologies, active-pixel sensors (APS) began to appear in 1990 at the 1 μm technology node. These pixels allow random access, global shutters, and they are compatible with focal-plane imaging systems combining sensing and first-level image processing. The progress towards smaller features and towards ultra-low leakage currents has provided reduced dark currents and μm-size pixels. All chips offer Mega-pixel resolution, and many have very high sensitivities equivalent to ASA 12.800. As a result, HDTV video cameras will become a commodity. Because charge-integration sensors suffer from a limited dynamic range, significant processing effort is spent on multiple exposure and piece-wise analog-digital conversion to reach ranges >10,000:1. The fundamental alternative is log-converting pixels with an eye-like response. This offers a range of almost a million to 1, constant contrast sensitivity and constant colors, important features in professional, technical and medical applications. 3D retino-morphic stacking of sensing and processing on top of each other is being revisited with sub-100 nm CMOS circuits and with TSV technology. With sensor outputs directly on top of neurons, neural focal-plane processing will regain momentum, and new levels of intelligent vision will be achieved. The industry push towards thinned wafers and TSV enables backside-illuminated and other pixels with a 100% fill-factor. 3D vision, which relies on stereo or on time-of-flight, high-speed circuitry, will also benefit from scaled-down CMOS technologies both because of their size as well as their higher speed.

  12. Silicon Detectors for PET and SPECT

    NASA Astrophysics Data System (ADS)

    Cochran, Eric R.

    Silicon detectors use state-of-the-art electronics to take advantage of the semiconductor properties of silicon to produce very high resolution radiation detectors. These detectors have been a fundamental part of high energy, nuclear, and astroparticle physics experiments for decades, and they hold great potential for significant gains in both PET and SPECT applications. Two separate prototype nuclear medicine imaging systems have been developed to explore this potential. Both devices take advantage of the unique properties of high resolution pixelated silicon detectors, designed and developed as part of the CIMA collaboration and built at The Ohio State University. The first prototype is a Compton SPECT imaging system. Compton SPECT, also referred to as electronic collimation, is a fundamentally different approach to single photon imaging from standard gamma cameras. It removes the inherent coupling of spatial resolution and sensitivity in mechanically collimated systems and provides improved performance at higher energies. As a result, Compton SPECT creates opportunities for the development of new radiopharmaceuticals based on higher energy isotopes as well as opportunities to expand the use of current isotopes such as 131I due to the increased resolution and sensitivity. The Compton SPECT prototype consists of a single high resolution silicon detector, configured in a 2D geometry, in coincidence with a standard NaI scintillator detector. Images of point sources have been taken for 99mTc (140 keV), 131I (364keV), and 22Na (511 keV), demonstrating the performance of high resolution silicon detectors in a Compton SPECT system. Filtered back projection image resolutions of 10 mm, 7.5 mm, and 6.7 mm were achieved for the three different sources respectively. The results compare well with typical SPECT resolutions of 5-15 mm and validate the claims of improved performance in Compton SPECT imaging devices at higher source energies. They also support the potential of

  13. Recent Developments in PET Instrumentation

    PubMed Central

    Peng, Hao; Levin, Craig S.

    2013-01-01

    Positron emission tomography (PET) is used in the clinic and in vivo small animal research to study molecular processes associated with diseases such as cancer, heart disease, and neurological disorders, and to guide the discovery and development of new treatments. This paper reviews current challenges of advancing PET technology and some of newly developed PET detectors and systems. The paper focuses on four aspects of PET instrumentation: high photon detection sensitivity; improved spatial resolution; depth-of-interaction (DOI) resolution and time-of-flight (TOF). Improved system geometry, novel non-scintillator based detectors, and tapered scintillation crystal arrays are able to enhance the photon detection sensitivity of a PET system. Several challenges for achieving high resolution with standard scintillator-based PET detectors are discussed. Novel detectors with 3-D positioning capability have great potential to be deployed in PET for achieving spatial resolution better than 1 mm, such as cadmium-zinc-telluride (CZT) and position-sensitive avalanche photodiodes (PSAPDs). DOI capability enables a PET system to mitigate parallax error and achieve uniform spatial resolution across the field-of-view (FOV). Six common DOI designs, as well as advantages and limitations of each design, are discussed. The availability of fast scintillation crystals such as LaBr3, and the silicon photomultiplier (SiPM) greatly advances TOF-PET development. Recent instrumentation and initial results of clinical trials are briefly presented. If successful, these technology advances, together with new probe molecules, will substantially enhance the molecular sensitivity of PET and thus increase its role in preclinical and clinical research as well as evaluating and managing disease in the clinic. PMID:20497121

  14. Fourier-wavelet restoration in PET/CT brain studies

    NASA Astrophysics Data System (ADS)

    Knešaurek, Karin

    2012-10-01

    Our goal is to improve brain PET imaging through the application of a novel, hybrid Fourier-wavelet (WFT) restoration technique. The major limitation of PET studies is a relatively poor resolution in comparison with MRI and CT imaging and there is a need for improved PET imaging. A GE DLS PET/CT 16 slice system was used to acquire the studies. In order to create restoration filters the point source study was performed. The 6-fillable spheres and 3D Hoffman brain phantom studies were acquired and used to test and optimize the restoration approach. The patient data used in the study were acquired in a 3D PET mode, using the standard clinical protocol. Here, we have implemented Fourier-wavelet regularized restoration. In the Fourier domain, the inverse of modulation transfer function was multiplied by a Butterworth low-pass filter, order n=6 and cut-off frequency f=0.35 cycles/pixel. In addition, wavelet (Daubechies, order 2) noise suppression was applied by “hard threshold”. Hot spheres and 3D Hoffman brain studies showed that the restoration process not only improves resolution and contrast but also improves quantification in 3D PET/CT imaging. The average contrast increase was 19% and the quantification improved in the range 8-20% depending on sphere size. In the restored images, there was no significant increase in noise when compared with the original images. The clinical studies followed brain phantom findings, i.e., the restored images had better contrast and resolution properties, when compared with the original images. The results of the study demonstrate that the quality and quantification of 3D brain 18F FDG PET images can be significantly improved by Fourier-wavelet (WFT) restoration filtering.

  15. PET/CT and radiotherapy in prostate cancer.

    PubMed

    De Jong, I J; De Haan, T D; Wiegman, E M; Van Den Bergh, A C M; Pruim, J; Breeuwsma, A J

    2010-10-01

    Radiotherapy is one of the corner stone treatments for patients with prostate cancer. Especially for locally advanced tumors radiotherapy +/- adjuvant androgen deprivation treatment is standard of care. This brings up the need for accurate assessment of extra prostatic tumor growth and/or the presence of nodal metastases for selection of the optimal radiation dose and treatment volume. Morphological imaging like transrectal ultra sound, computed tomography (CT) and magnetic resonance imaging (MRI) are routinely used but are limited in their accuracy in detecting extra prostatic extension and nodal metastases. In this article we present a structured review of the literature on positron emission tomography (PET)/CT and radiotherapy in prostate cancer patients with emphasis on: 1) the pretreatment assessment of extra prostatic tumor extension, nodal and distant metastases; 2) the intraprostatic tumor characterization and radiotherapy treatment planning; and 3) treatment evaluation and the use of PET/CT in guidance of salvage treatment. PET/CT is not an appropriate imaging technique for accurate T-staging of prostate cancer prior to radiotherapy. Although macroscopic disease beyond the prostatic capsule and into the periprostatic fat or in seminal vesicle is often accurately detected, the microscopic extension of prostate cancer remains undetected. Choline PET/CT holds a great potential as a single step diagnostic procedure of lymph nodes and skeleton, which could facilitate radiotherapy treatment planning. At present the use of PET/CT for treatment planning in radiotherapy is still experimental. Choline PET based tumor delineation is not yet standardized and different segmentation-algorithms are under study. However, dose escalation using dose-painting is feasible with only limited increases of the doses to the bladder and rectum wall. PET/CT using either acetate or choline is able to detect recurrent prostate cancer after radiotherapy but stratification of patients

  16. SMART-1/AMIE Camera System

    NASA Astrophysics Data System (ADS)

    Josset, J.-L.; Beauvivre, S.; Cerroni, P.; de Sanctis, M. C.; Pinet, P.; Chevrel, S.; Langevin, Y.; Barucci, M. A.; Plancke, P.; Koschny, D.; Almeida, M.; Sodnik, Z.; Mancuso, S.; Hofmann, B. A.; Muinonen, K.; Shevchenko, V.; Shkuratov, Y.; Ehrenfreund, P.; Foing, B. H.

    2006-03-01

    The Advanced Moon micro-Imager Experiment (AMIE), on board ESA SMART-1, the first European mission to the Moon (launched on 27th September 2003), is a camera system with scientific, technical and public outreach oriented objectives.

  17. An Inexpensive Digital Infrared Camera

    ERIC Educational Resources Information Center

    Mills, Allan

    2012-01-01

    Details are given for the conversion of an inexpensive webcam to a camera specifically sensitive to the near infrared (700-1000 nm). Some experiments and practical applications are suggested and illustrated. (Contains 9 figures.)

  18. 36 CFR 1002.15 - Pets.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 3 2011-07-01 2011-07-01 false Pets. 1002.15 Section 1002.15....15 Pets. (a) The following are prohibited: (1) Possessing a pet in a public building, public... possession of pets by the Board. This paragraph shall not apply to guide dogs accompanying visually...

  19. 36 CFR 2.15 - Pets.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Pets. 2.15 Section 2.15 Parks... USE AND RECREATION § 2.15 Pets. (a) The following are prohibited: (1) Possessing a pet in a public... area closed to the possession of pets by the superintendent. This subparagraph shall not apply to...

  20. 36 CFR 2.15 - Pets.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 1 2011-07-01 2011-07-01 false Pets. 2.15 Section 2.15 Parks... USE AND RECREATION § 2.15 Pets. (a) The following are prohibited: (1) Possessing a pet in a public... area closed to the possession of pets by the superintendent. This subparagraph shall not apply to...

  1. 36 CFR 1002.15 - Pets.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Pets. 1002.15 Section 1002.15....15 Pets. (a) The following are prohibited: (1) Possessing a pet in a public building, public... possession of pets by the Board. This paragraph shall not apply to guide dogs accompanying visually...

  2. 7 CFR 502.11 - Pets.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 6 2011-01-01 2011-01-01 false Pets. 502.11 Section 502.11 Agriculture Regulations of... CONDUCT ON BELTSVILLE AGRICULTURE RESEARCH CENTER PROPERTY, BELTSVILLE, MARYLAND § 502.11 Pets. Pets... vaccinations. Pets that are the property of employees residing on BARC must be up to date on their...

  3. 7 CFR 502.11 - Pets.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 6 2010-01-01 2010-01-01 false Pets. 502.11 Section 502.11 Agriculture Regulations of... CONDUCT ON BELTSVILLE AGRICULTURE RESEARCH CENTER PROPERTY, BELTSVILLE, MARYLAND § 502.11 Pets. Pets... vaccinations. Pets that are the property of employees residing on BARC must be up to date on their...

  4. Solid State Television Camera (CID)

    NASA Technical Reports Server (NTRS)

    Steele, D. W.; Green, W. T.

    1976-01-01

    The design, development and test are described of a charge injection device (CID) camera using a 244x248 element array. A number of video signal processing functions are included which maximize the output video dynamic range while retaining the inherently good resolution response of the CID. Some of the unique features of the camera are: low light level performance, high S/N ratio, antiblooming, geometric distortion, sequential scanning and AGC.

  5. The future of consumer cameras

    NASA Astrophysics Data System (ADS)

    Battiato, Sebastiano; Moltisanti, Marco

    2015-03-01

    In the last two decades multimedia, and in particular imaging devices (camcorders, tablets, mobile phones, etc.) have been dramatically diffused. Moreover the increasing of their computational performances, combined with an higher storage capability, allows them to process large amount of data. In this paper an overview of the current trends of consumer cameras market and technology will be given, providing also some details about the recent past (from Digital Still Camera up today) and forthcoming key issues.

  6. PET-Based Thoracic Radiation Oncology.

    PubMed

    Simone, Charles B; Houshmand, Sina; Kalbasi, Anusha; Salavati, Ali; Alavi, Abass

    2016-07-01

    Fluorodeoxyglucose-PET is increasingly being integrated into multiple aspects of oncology. PET/computed tomography (PET/CT) has become especially important in radiation oncology. With the increasing use of advanced techniques like intensity-modulated radiation therapy and proton therapy, PET/CT scans have played critical roles in the target delineation of tumors for radiation oncologists delivering conformal treatment techniques. Use of PET/CT is well established in lung cancer and several other thoracic malignancies. This article details the current uses of PET/CT in thoracic radiation oncology with a focus on lung cancer and describes expected future roles of PET/CT for thoracic tumors.

  7. Positron emission tomography (PET) for cholangiocarcinoma

    PubMed Central

    Breitenstein, S.; Apestegui, C.

    2008-01-01

    The combination of positron emission tomography (PET) with computed tomography (PET-CT) provides simultaneous metabolic and anatomic information on tumors in the same imaging session. Sensitivity of PET/PET-CT is higher for intrahepatic (>90%) than for extrahepatic cholangiocarcinoma (CCA) (about 60%). The detection rate of distant metastasis is 100%. PET, and particularly PET-CT, improves the results and impacts on the oncological management in CCA compared with other imaging modalities. Therefore, PET-CT is recommended in the preoperative staging of intrahepatic (strength of recommendation: moderate) and extrahepatic (strength of recommendation: low) CCA. PMID:18773069

  8. Imaging performance of LabPET APD-based digital PET scanners for pre-clinical research

    NASA Astrophysics Data System (ADS)

    Bergeron, Mélanie; Cadorette, Jules; Tétrault, Marc-André; Beaudoin, Jean-François; Leroux, Jean-Daniel; Fontaine, Réjean; Lecomte, Roger

    2014-02-01

    The LabPET is an avalanche photodiode (APD) based digital PET scanner with quasi-individual detector read-out and highly parallel electronic architecture for high-performance in vivo molecular imaging of small animals. The scanner is based on LYSO and LGSO scintillation crystals (2×2×12/14 mm3), assembled side-by-side in phoswich pairs read out by an APD. High spatial resolution is achieved through the individual and independent read-out of an individual APD detector for recording impinging annihilation photons. The LabPET exists in three versions, LabPET4 (3.75 cm axial length), LabPET8 (7.5 cm axial length) and LabPET12 (11.4 cm axial length). This paper focuses on the systematic characterization of the three LabPET versions using two different energy window settings to implement a high-efficiency mode (250-650 keV) and a high-resolution mode (350-650 keV) in the most suitable operating conditions. Prior to measurements, a global timing alignment of the scanners and optimization of the APD operating bias have been carried out. Characteristics such as spatial resolution, absolute sensitivity, count rate performance and image quality have been thoroughly investigated following the NEMA NU 4-2008 protocol. Phantom and small animal images were acquired to assess the scanners' suitability for the most demanding imaging tasks in preclinical biomedical research. The three systems achieve the same radial FBP spatial resolution at 5 mm from the field-of-view center: 1.65/3.40 mm (FWHM/FWTM) for an energy threshold of 250 keV and 1.51/2.97 mm for an energy threshold of 350 keV. The absolute sensitivity for an energy window of 250-650 keV is 1.4%/2.6%/4.3% for LabPET4/8/12, respectively. The best count rate performance peaking at 362 kcps is achieved by the LabPET12 with an energy window of 250-650 keV and a mouse phantom (2.5 cm diameter) at an activity of 2.4 MBq ml-1. With the same phantom, the scatter fraction for all scanners is about 17% for an energy threshold of

  9. Science, conservation, and camera traps

    USGS Publications Warehouse

    Nichols, James D.; Karanth, K. Ullas; O'Connel, Allan F.; O'Connell, Allan F.; Nichols, James D.; Karanth, K. Ullas

    2011-01-01

    Biologists commonly perceive camera traps as a new tool that enables them to enter the hitherto secret world of wild animals. Camera traps are being used in a wide range of studies dealing with animal ecology, behavior, and conservation. Our intention in this volume is not to simply present the various uses of camera traps, but to focus on their use in the conduct of science and conservation. In this chapter, we provide an overview of these two broad classes of endeavor and sketch the manner in which camera traps are likely to be able to contribute to them. Our main point here is that neither photographs of individual animals, nor detection history data, nor parameter estimates generated from detection histories are the ultimate objective of a camera trap study directed at either science or management. Instead, the ultimate objectives are best viewed as either gaining an understanding of how ecological systems work (science) or trying to make wise decisions that move systems from less desirable to more desirable states (conservation, management). Therefore, we briefly describe here basic approaches to science and management, emphasizing the role of field data and associated analyses in these processes. We provide examples of ways in which camera trap data can inform science and management.

  10. The camera convergence problem revisited

    NASA Astrophysics Data System (ADS)

    Allison, Robert S.

    2004-05-01

    Convergence of the real or virtual stereoscopic cameras is an important operation in stereoscopic display systems. For example, convergence can shift the range of portrayed depth to improve visual comfort; can adjust the disparity of targets to bring them nearer to the screen and reduce accommodation-vergence conflict; or can bring objects of interest into the binocular field-of-view. Although camera convergence is acknowledged as a useful function, there has been considerable debate over the transformation required. It is well known that rotational camera convergence or 'toe-in' distorts the images in the two cameras producing patterns of horizontal and vertical disparities that can cause problems with fusion of the stereoscopic imagery. Behaviorally, similar retinal vertical disparity patterns are known to correlate with viewing distance and strongly affect perception of stereoscopic shape and depth. There has been little analysis of the implications of recent findings on vertical disparity processing for the design of stereoscopic camera and display systems. We ask how such distortions caused by camera convergence affect the ability to fuse and perceive stereoscopic images.

  11. Microfluidics: a groundbreaking technology for PET tracer production?

    PubMed

    Rensch, Christian; Jackson, Alexander; Lindner, Simon; Salvamoser, Ruben; Samper, Victor; Riese, Stefan; Bartenstein, Peter; Wängler, Carmen; Wängler, Björn

    2013-07-05

    Application of microfluidics to Positron Emission Tomography (PET) tracer synthesis has attracted increasing interest within the last decade. The technical advantages of microfluidics, in particular the high surface to volume ratio and resulting fast thermal heating and cooling rates of reagents can lead to reduced reaction times, increased synthesis yields and reduced by-products. In addition automated reaction optimization, reduced consumption of expensive reagents and a path towards a reduced system footprint have been successfully demonstrated. The processing of radioactivity levels required for routine production, use of microfluidic-produced PET tracer doses in preclinical and clinical imaging as well as feasibility studies on autoradiolytic decomposition have all given promising results. However, the number of microfluidic synthesizers utilized for commercial routine production of PET tracers is very limited. This study reviews the state of the art in microfluidic PET tracer synthesis, highlighting critical design aspects, strengths, weaknesses and presenting several characteristics of the diverse PET market space which are thought to have a significant impact on research, development and engineering of microfluidic devices in this field. Furthermore, the topics of batch- and single-dose production, cyclotron to quality control integration as well as centralized versus de-centralized market distribution models are addressed.

  12. Micromechanics and advanced designs for curved photodetector arrays in hemispherical electronic-eye cameras.

    PubMed

    Shin, Gunchul; Jung, Inhwa; Malyarchuk, Viktor; Song, Jizhou; Wang, Shuodao; Ko, Heung Cho; Huang, Yonggang; Ha, Jeong Sook; Rogers, John A

    2010-04-09

    The fabrication of a hemispherical electronic-eye camera with optimized designs based upon micromechanical analysis is reported. The photodetector arrays combine layouts with multidevice tiles and extended, non-coplanar interconnects to improve the fill factor and deformability, respectively. Quantitative comparison to micromechanics analysis reveals the key features of these designs. Color images collected with working cameras demonstrate the utility of these approaches.

  13. Understanding regulations affecting pet foods.

    PubMed

    Dzanis, David A

    2008-08-01

    In the United States, pet foods are subject to regulation at both the federal and the state levels. The US Food and Drug Administration has jurisdiction over all animal feeds (including pet foods, treats, chews, supplements, and ingredients) in interstate commerce, which includes imported products. Many states adopt and enforce at least in part the Association of American Feed Control Officials Model Bill and Model Regulations for Pet Food and Specialty Pet Food. Thus, all pet foods in multi-state distribution are subject to a host of labeling requirements covering aspects such as product names, ingredient lists, nutrient content guarantees, and nutritional adequacy statements. Ingredients must be GRAS (generally recognized as safe) substances, approved food additives, or defined by Association of American Feed Control Officials for their intended use. Pet food labels may not bear claims that are false or misleading or that state or imply use for the treatment or prevention of disease. Pet foods that are found to be adulterated or misbranded may be subject to seizure or other enforcement actions.

  14. Fast camera objective designs for spectrograph of Mont Megantique telescope

    NASA Astrophysics Data System (ADS)

    Thibault, Simon; Wang, Min

    2004-02-01

    All-reflective optics is conventionally required for extended spectral region observations in astronomical spectrograph. But the spatial resolution is usually not good enough while the large-size CCD will be used for observation in all-reflective optics. In this paper, all-refractive optics has been investigated to design a fast (F/1.55) and wide angle camera objective for large spectral coverage, from UV to VIS and up to NIR, when a large-size CCD is used on the focal plane of the spectrograph of Mont Megantique telescope. The case of achromatic and apochromatic condition has been investigated for axial and lateral color controls. The new proposed solutions have been optimized from two to three different glass combinations in order to have higher throughputs for large spectral coverage, especially in UV region. The used components have been minimized to reduce the light inherent lost. The monochromatic aberrations have been corrected and controlled by using optimized lens bending and shapes to make the camera have the CCD pixel resolution. Ray tracing results displayed the good optical performance of the camera to cover from 350 nm to 1000 nm spectral region with high resolution. The broadband AR coating, enhanced on UV region, will be used on each surface of the lenses in the camera. Final throughputs for the designed camera has been estimated and given in the paper.

  15. Diagnostic accuracy of CSF Ab42 and florbetapir PET for Alzheimer's disease

    PubMed Central

    Mattsson, Niklas; Insel, Philip S; Landau, Susan; Jagust, William; Donohue, Michael; Shaw, Leslie M; Trojanowski, John Q; Zetterberg, Henrik; Blennow, Kaj; Weiner, Michael

    2014-01-01

    Background Reduced cerebrospinal fluid (CSF) β-amyloid42 (Aβ42) and increased florbetapir positron emission tomography (PET) uptake reflects brain Aβ accumulation. These biomarkers are correlated with each other and altered in Alzheimer's disease (AD), but no study has directly compared their diagnostic performance. Methods We examined healthy controls (CN, N = 169) versus AD dementia patients (N = 118), and stable (sMCI; no dementia, followed up for at least 2 years, N = 165) versus progressive MCI (pMCI; conversion to AD dementia, N = 59). All subjects had florbetapir PET (global and regional; temporal, frontal, parietal, and cingulate) and CSF Aβ42 measurements at baseline. We compared area under the curve (AUC), sensitivity, and specificity (testing a priori and optimized cutoffs). Clinical diagnosis was the reference standard. Results CSF Aβ42 and (global or regional) PET florbetapir did not differ in AUC (CN vs. AD, CSF 84.4%; global PET 86.9%; difference [95% confidence interval] −6.7 to 1.5). CSF Aβ42 and global PET florbetapir did not differ in sensitivity, but PET had greater specificity than CSF in most comparisons. Sixteen CN progressed to MCI and AD (six Aβ negative, seven Aβ positive, and three PET positive but CSF negative). Interpretation The overall diagnostic accuracies of CSF Aβ42 and PET florbetapir were similar, but PET had greater specificity. This was because some CN and sMCI subjects appear pathological using CSF but not using PET, suggesting that low CSF Aβ42 not always translates to cognitive decline or brain Aβ accumulation. Other factors, including costs and side effects, may also be considered when determining the optimal modality for different applications. PMID:25356425

  16. Segmentation of brain PET-CT images based on adaptive use of complementary information

    NASA Astrophysics Data System (ADS)

    Xia, Yong; Wen, Lingfeng; Eberl, Stefan; Fulham, Michael; Feng, Dagan

    2009-02-01

    Dual modality PET-CT imaging provides aligned anatomical (CT) and functional (PET) images in a single scanning session, which can potentially be used to improve image segmentation of PET-CT data. The ability to distinguish structures for segmentation is a function of structure and modality and varies across voxels. Thus optimal contribution of a particular modality to segmentation is spatially variant. Existing segmentation algorithms, however, seldom account for this characteristic of PET-CT data and the results using these algorithms are not optimal. In this study, we propose a relative discrimination index (RDI) to characterize the relative abilities of PET and CT to correctly classify each voxel into the correct structure for segmentation. The definition of RDI is based on the information entropy of the probability distribution of the voxel's class label. If the class label derived from CT data for a particular voxel has more certainty than that derived from PET data, the corresponding RDI will have a higher value. We applied the RDI matrix to balance adaptively the contributions of PET and CT data to segmentation of brain PET-CT images on a voxel-by-voxel basis, with the aim to give the modality with higher discriminatory power a larger weight. The resultant segmentation approach is distinguished from traditional approaches by its innovative and adaptive use of the dual-modality information. We compared our approach to the non-RDI version and two commonly used PET-only based segmentation algorithms for simulation and clinical data. Our results show that the RDI matrix markedly improved PET-CT image segmentation.

  17. The MC and LFC cameras. [metric camera (MC); large format camera (LFC)

    NASA Technical Reports Server (NTRS)

    Norton, Clarice L.; Schroeder, Manfried; Mollberg, Bernard

    1986-01-01

    The characteristics of the shuttle-borne Large Format Camera are listed. The LFC focal plane format was 23 by 46 cm, double the usual size, thereby acquiring approximately double the ground area. Forward motion compensation was employed. With the stable platform (shuttle) it was possible to use the slow exposure, high resolution, Kodak aerial films; 3414 and 3412 black and white, SO-242 color, and SO-131 aerochrome infrared. The camera was designed to maintain stability during varying temperature extremes of space.

  18. NEMA NU 4-2008 validation and applications of the PET-SORTEO Monte Carlo simulations platform for the geometry of the Inveon PET preclinical scanner

    NASA Astrophysics Data System (ADS)

    Boisson, F.; Wimberley, C. J.; Lehnert, W.; Zahra, D.; Pham, T.; Perkins, G.; Hamze, H.; Gregoire, M.-C.; Reilhac, A.

    2013-10-01

    Monte Carlo-based simulation of positron emission tomography (PET) data plays a key role in the design and optimization of data correction and processing methods. Our first aim was to adapt and configure the PET-SORTEO Monte Carlo simulation program for the geometry of the widely distributed Inveon PET preclinical scanner manufactured by Siemens Preclinical Solutions. The validation was carried out against actual measurements performed on the Inveon PET scanner at the Australian Nuclear Science and Technology Organisation in Australia and at the Brain & Mind Research Institute and by strictly following the NEMA NU 4-2008 standard. The comparison of simulated and experimental performance measurements included spatial resolution, sensitivity, scatter fraction and count rates, image quality and Derenzo phantom studies. Results showed that PET-SORTEO reliably reproduces the performances of this Inveon preclinical system. In addition, imaging studies showed that the PET-SORTEO simulation program provides raw data for the Inveon scanner that can be fully corrected and reconstructed using the same programs as for the actual data. All correction techniques (attenuation, scatter, randoms, dead-time, and normalization) can be applied on the simulated data leading to fully quantitative reconstructed images. In the second part of the study, we demonstrated its ability to generate fast and realistic biological studies. PET-SORTEO is a workable and reliable tool that can be used, in a classical way, to validate and/or optimize a single PET data processing step such as a reconstruction method. However, we demonstrated that by combining a realistic simulated biological study ([11C]Raclopride here) involving different condition groups, simulation allows one also to assess and optimize the data correction, reconstruction and data processing line flow as a whole, specifically for each biological study, which is our ultimate intent.

  19. Veterinarians' role for pet owners facing pet loss

    PubMed Central

    Fernandez-Mehler, P.; Gloor, P.; Sager, E.; Lewis, F. I.; Glaus, T. M

    2013-01-01

    Owners' satisfaction with, and expectations from, their veterinarians around euthanasia, including questions on disposal of pet remains subject to animal species, clients' gender, age, family conditions, area of living and type of veterinary clinic visited were evaluated by questionnaire. Questionnaires were to be filled out by clients consecutively visiting the individual practices and hospitals for any kind of consultations. Of 2350 questionnaires distributed, 2008 were returned and available for analysis. Owner satisfaction concerning the procedure of euthanasia was high (92 per cent, 1173/1272). After the event of euthanasia, 14 per cent (170/1250) had changed their veterinarian, even though 75 per cent of these 170 had been satisfied with the procedure. Most owners (88 per cent) expected veterinarians to talk about their pet's final destination, and 38 per cent expected this to happen early in the pet's life. For 81 per cent clients, the veterinarian was the primary informant about the possibilities concerning the disposal of pet remains, and 33 per cent indicated their veterinarian as the contact person to talk about pet loss. Area of living, or veterinary specialisation, only marginally influenced the answers. Veterinarians play an important role to inform their clients concerning questions around euthanasia and the care of pet remains, and to support them during the process of mourning. PMID:23492929

  20. Veterinarians' role for pet owners facing pet loss.

    PubMed

    Fernandez-Mehler, P; Gloor, P; Sager, E; Lewis, F I; Glaus, T M

    2013-05-25

    Owners' satisfaction with, and expectations from, their veterinarians around euthanasia, including questions on disposal of pet remains subject to animal species, clients' gender, age, family conditions, area of living and type of veterinary clinic visited were evaluated by questionnaire. Questionnaires were to be filled out by clients consecutively visiting the individual practices and hospitals for any kind of consultations. Of 2350 questionnaires distributed, 2008 were returned and available for analysis. Owner satisfaction concerning the procedure of euthanasia was high (92 per cent, 1173/1272). After the event of euthanasia, 14 per cent (170/1250) had changed their veterinarian, even though 75 per cent of these 170 had been satisfied with the procedure. Most owners (88 per cent) expected veterinarians to talk about their pet's final destination, and 38 per cent expected this to happen early in the pet's life. For 81 per cent clients, the veterinarian was the primary informant about the possibilities concerning the disposal of pet remains, and 33 per cent indicated their veterinarian as the contact person to talk about pet loss. Area of living, or veterinary specialisation, only marginally influenced the answers. Veterinarians play an important role to inform their clients concerning questions around euthanasia and the care of pet remains, and to support them during the process of mourning.

  1. Principles of nuclear medicine imaging: planar, SPECT, PET, multi-modality, and autoradiography systems.

    PubMed

    Zanzonico, Pat

    2012-04-01

    The underlying principles of nuclear medicine imaging involve the use of unsealed sources of radioactivity in the form of radiopharmaceuticals. The ionizing radiations that accompany the decay of the administered radioactivity can be quantitatively detected, measured, and imaged in vivo with instruments such as gamma cameras. This paper reviews the design and operating principles, as well as the capabilities and limitations, of instruments used clinically and preclinically for in vivo radionuclide imaging. These include gamma cameras, single-photon emission computed tomography (SPECT) scanners, and positron emission tomography (PET) scanners. The technical basis of autoradiography is reviewed as well.

  2. Specific recommendations for accurate and direct use of PET-CT in PET guided radiotherapy for head and neck sites

    SciTech Connect

    Thomas, C. M. Convery, D. J.; Greener, A. G.; Pike, L. C.; Baker, S.; Woods, E.; Hartill, C. E.

    2014-04-15

    techniques, laser positioning may affect setup accuracy and couch deflection may be greater than scanners dedicated to radiotherapy. The full set of departmental commissioning and routine quality assurance tests applied to radiotherapy CT simulators must be carried out on the PET-CT scanner. CT image quality must be optimized for radiotherapy planning whilst understanding that the appearance will differ between scanners and may affect delineation. PET-CT quality assurance schedules will need to be added to and modified to incorporate radiotherapy quality assurance. Methods of working for radiotherapy and PET staff will change to take into account considerations of both parties. PET to CT alignment must be subject to quality control on a loaded and unloaded couch preferably using a suitable emission phantom, and tested throughout the whole data pathway. Data integrity must be tested throughout the whole pathway and a system included to verify that delineated structures are transferred correctly. Excellent multidisciplinary team communication and working is vital, and key staff members on both sides should be specifically dedicated to the project. Patient pathway should be clearly devised to optimize patient care and the resources of all departments. Recruitment of a cohort of patients into a methodology study is valuable to test the quality assurance methods and pathway.

  3. Sub-Camera Calibration of a Penta-Camera

    NASA Astrophysics Data System (ADS)

    Jacobsen, K.; Gerke, M.

    2016-03-01

    Penta cameras consisting of a nadir and four inclined cameras are becoming more and more popular, having the advantage of imaging also facades in built up areas from four directions. Such system cameras require a boresight calibration of the geometric relation of the cameras to each other, but also a calibration of the sub-cameras. Based on data sets of the ISPRS/EuroSDR benchmark for multi platform photogrammetry the inner orientation of the used IGI Penta DigiCAM has been analyzed. The required image coordinates of the blocks Dortmund and Zeche Zollern have been determined by Pix4Dmapper and have been independently adjusted and analyzed by program system BLUH. With 4.1 million image points in 314 images respectively 3.9 million image points in 248 images a dense matching was provided by Pix4Dmapper. With up to 19 respectively 29 images per object point the images are well connected, nevertheless the high number of images per object point are concentrated to the block centres while the inclined images outside the block centre are satisfying but not very strongly connected. This leads to very high values for the Student test (T-test) of the finally used additional parameters or in other words, additional parameters are highly significant. The estimated radial symmetric distortion of the nadir sub-camera corresponds to the laboratory calibration of IGI, but there are still radial symmetric distortions also for the inclined cameras with a size exceeding 5μm even if mentioned as negligible based on the laboratory calibration. Radial and tangential effects of the image corners are limited but still available. Remarkable angular affine systematic image errors can be seen especially in the block Zeche Zollern. Such deformations are unusual for digital matrix cameras, but it can be caused by the correlation between inner and exterior orientation if only parallel flight lines are used. With exception of the angular affinity the systematic image errors for corresponding

  4. PET/CT in radiation oncology

    SciTech Connect

    Pan, Tinsu; Mawlawi, Osama

    2008-11-15

    PET/CT is an effective tool for the diagnosis, staging and restaging of cancer patients. It combines the complementary information of functional PET images and anatomical CT images in one imaging session. Conventional stand-alone PET has been replaced by PET/CT for improved patient comfort, patient throughput, and most importantly the proven clinical outcome of PET/CT over that of PET and that of separate PET and CT. There are over two thousand PET/CT scanners installed worldwide since 2001. Oncology is the main application for PET/CT. Fluorine-18 deoxyglucose is the choice of radiopharmaceutical in PET for imaging the glucose uptake in tissues, correlated with an increased rate of glycolysis in many tumor cells. New molecular targeted agents are being developed to improve the accuracy of targeting different disease states and assessing therapeutic response. Over 50% of cancer patients receive radiation therapy (RT) in the course of their disease treatment. Clinical data have demonstrated that the information provided by PET/CT often changes patient management of the patient and/or modifies the RT plan from conventional CT simulation. The application of PET/CT in RT is growing and will become increasingly important. Continuing improvement of PET/CT instrumentation will also make it easier for radiation oncologists to integrate PET/CT in RT. The purpose of this article is to provide a review of the current PET/CT technology, to project the future development of PET and CT for PET/CT, and to discuss some issues in adopting PET/CT in RT and potential improvements in PET/CT simulation of the thorax in radiation therapy.

  5. Preliminary Design of Pinhole camera for NSLS-II Project.

    SciTech Connect

    Pinayev,I.; Kosciuk, B.; Singh, O.

    2009-05-04

    The NSLS-II Light Source being built at Brookhaven National Laboratory is expected to provide very small emittances and electron beam sizes. High resolution imaging systems are required in order to provide robust measurements. The pinhole camera will utilize 6-fold magnification with a pinhole placed inside a crotch absorber. The pinhole is protected from high power synchrotron radiation with a filter made of refractory metal. In this paper we provide resolution analyses, heat load calculations, and optimization details for the NSLS-II pinhole camera, including beamline design.

  6. Analysis of Pet Coke Samples

    EPA Pesticide Factsheets

    EPA required KCBX to submit samples of the petroleum coke stored at their North and South Chicago terminals to EPA's Chicago Regional Laboratory for analysis of pollutant levels. Results will be compared to coal and pet coke sampled in Detroit.

  7. Take Care with Pet Reptiles

    MedlinePlus

    ... CDC Features Take Care with Pet Reptiles and Amphibians Language: English Español (Spanish) Recommend on Facebook Tweet ... helpful resources. Safe Handling Tips for Reptiles and Amphibians Always wash your hands thoroughly after handling reptiles ...

  8. Behavior problems in geriatric pets.

    PubMed

    Landsberg, Gary; Araujo, Joseph A

    2005-05-01

    Aging pets often suffer a decline in cognitive function (eg, memory,learning, perception, awareness) likely associated with age-dependent brain alterations. Clinically, cognitive dysfunction may result in various behavioral signs, including disorientation; forgetting of previously learned behaviors, such as house training; alterations in the manner in which the pet interacts with people or other pets;onset of new fears and anxiety; decreased recognition of people, places, or pets; and other signs of deteriorating memory and learning ability. Many medical problems, including other forms of brain pathologic conditions, can contribute to these signs. The practitioner must first determine the cause of the behavioral signs and then determine an appropriate course of treatment, bearing in mind the constraints of the aging process. A diagnosis of cognitive dysfunction syndrome is made once other medical and behavioral causes are ruled out.

  9. Should Immunocompromised Patients Have Pets?

    PubMed Central

    Steele, Russell W.

    2008-01-01

    Purpose: To evaluate the risks and benefits of pet ownership by immunodeficient patients, focusing primarily on organisms that colonize animals and are transmitted to humans. Those diseases that are known to be progressive or more severe in patients with altered immune function are emphasized. Methods: A review of the medical and veterinary literature pertaining to zoonoses transmitted by domestic animals was completed. Information pertaining to issues involving immunosuppressed patients including AIDS was carefully evaluated and summarized for inclusion. Results: There are significant clinical and psychosocial benefits to pet ownership. However, numerous diseases can be acquired from these animals which may be more severe in immunocompromised individuals. Conclusion: Simple guidelines for pet ownership by immunosuppressed patients can be implemented to reduce their risk of disease and allow them to safely interchange with their pets. PMID:21603465

  10. 10 "Poison Pills" for Pets

    MedlinePlus

    ... left on the bedside table. Zolpidem may make cats wobbly and sleepy, but most pets become very ... very common pain killer found in most households. Cats are extremely sensitive to acetaminophen, but dogs can ...

  11. Single-Cell Tracking with PET using a Novel Trajectory Reconstruction Algorithm

    PubMed Central

    Lee, Keum Sil; Kim, Tae Jin

    2015-01-01

    Virtually all biomedical applications of positron emission tomography (PET) use images to represent the distribution of a radiotracer. However, PET is increasingly used in cell tracking applications, for which the “imaging” paradigm may not be optimal. Here we investigate an alternative approach, which consists in reconstructing the time-varying position of individual radiolabeled cells directly from PET measurements. As a proof of concept, we formulate a new algorithm for reconstructing the trajectory of one single moving cell directly from list-mode PET data. We model the trajectory as a 3D B-spline function of the temporal variable and use non-linear optimization to minimize the mean-square distance between the trajectory and the recorded list-mode coincidence events. Using Monte Carlo simulations (GATE), we show that this new algorithm can track a single source moving within a small-animal PET system with <3 mm accuracy provided that the activity of the cell [Bq] is greater than four times its velocity [mm/s]. The algorithm outperforms conventional ML-EM as well as the “minimum distance” method used for positron emission particle tracking (PEPT). The new method was also successfully validated using experimentally acquired PET data. In conclusion, we demonstrated the feasibility of a new method for tracking a single moving cell directly from PET list-mode data, at the whole-body level, for physiologically relevant activities and velocities. PMID:25423651

  12. Monte Carlo simulation of sensitivity and NECR of an entire-body PET scanner.

    PubMed

    Isnaini, Ismet; Obi, Takashi; Yoshida, Eiji; Yamaya, Taiga

    2014-07-01

    The current positron emission tomography (PET) design is aimed toward establishing an entire-body PET scanner. An entire-body PET scanner is a scanner whose axial field of view (FOV) covers the whole body of a patient, whereas whole-body PET scanner can be of any axial FOV length, but was designed for a whole-body scan. Despite its high production cost, an entire-body depth-of-interaction PET scanner offers many benefits, such as shorter and dynamic PET time acquisition, as well as higher sensitivity and count rate performance. This PET scanner may be cost-effective for clinical PET scanners with high scan throughput. In this work, we evaluated the sensitivity and count rate performance of a 2-m-long PET scanner with conventional data acquisition (DAQ) architecture, using Monte Carlo simulation, and we evaluated two ring diameters (60 and 80 cm) to reduce the scanner cost. From simulation of scanning with a 2-m axial FOV, the sensitivity for a 2-m-long PET scanner of 60 and 80-cm diameter is around 80 and 68 times higher, respectively, than that of the conventional PET scanner. In addition, for the 2-m-long PET scanner with 60-cm diameter, the peak noise equivalent count rate (NECR) was 843 kcps at 125 MBq, whereas the peak for the 80-cm diameter was 989 kcps at 200 MBq. This shows gains of 15.3 and 17.95, respectively, in comparison with that of the conventional PET scanner. The 2-m-long PET scanner with 60-cm ring diameter could not only reduce the number of detectors by 21 %, but also had a 17 % higher sensitivity compared to that with an 80-cm ring diameter. On the other hand, despite the higher sensitivity, the NECR of the 60-cm ring diameter was smaller than that of the 80-cm ring diameter. This results from the single data loss due to dead time, whereas grouping of axially stacked detectors was used in the conventional DAQ architecture. Parallelization of the DAQ architecture is therefore important for the 2-m-long PET scanner to achieve its optimal

  13. The Clementine longwave infrared camera

    SciTech Connect

    Priest, R.E.; Lewis, I.T.; Sewall, N.R.; Park, H.S.; Shannon, M.J.; Ledebuhr, A.G.; Pleasance, L.D.; Massie, M.A.; Metschuleit, K.

    1995-04-01

    The Clementine mission provided the first ever complete, systematic surface mapping of the moon from the ultra-violet to the near-infrared regions. More than 1.7 million images of the moon, earth and space were returned from this mission. The longwave-infrared (LWIR) camera supplemented the UV/Visible and near-infrared mapping cameras providing limited strip coverage of the moon, giving insight to the thermal properties of the soils. This camera provided {approximately}100 m spatial resolution at 400 km periselene, and a 7 km across-track swath. This 2.1 kg camera using a 128 x 128 Mercury-Cadmium-Telluride (MCT) FPA viewed thermal emission of the lunar surface and lunar horizon in the 8.0 to 9.5 {micro}m wavelength region. A description of this light-weight, low power LWIR camera along with a summary of lessons learned is presented. Design goals and preliminary on-orbit performance estimates are addressed in terms of meeting the mission`s primary objective for flight qualifying the sensors for future Department of Defense flights.

  14. Traditional gamma cameras are preferred.

    PubMed

    DePuey, E Gordon

    2016-08-01

    Although the new solid-state dedicated cardiac cameras provide excellent spatial and energy resolution and allow for markedly reduced SPECT acquisition times and/or injected radiopharmaceutical activity, they have some distinct disadvantages compared to traditional sodium iodide SPECT cameras. They are expensive. Attenuation correction is not available. Cardio-focused collimation, advantageous to increase depth-dependent resolution and myocardial count density, accentuates diaphragmatic attenuation and scatter from subdiaphragmatic structures. Although supplemental prone imaging is therefore routinely advised, many patients cannot tolerate it. Moreover, very large patients cannot be accommodated in the solid-state camera gantries. Since data are acquired simultaneously with an arc of solid-state detectors around the chest, no temporally dependent "rotating" projection images are obtained. Therefore, patient motion can be neither detected nor corrected. In contrast, traditional sodium iodide SPECT cameras provide rotating projection images to allow technologists and physicians to detect and correct patient motion and to accurately detect the position of soft tissue attenuators and to anticipate associated artifacts. Very large patients are easily accommodated. Low-dose x-ray attenuation correction is widely available. Also, relatively inexpensive low-count density software is provided by many vendors, allowing shorter SPECT acquisition times and reduced injected activity approaching that achievable with solid-state cameras.

  15. Energy and coincidence time resolution measurements of CdTe detectors for PET.

    PubMed

    Ariño, G; Chmeissani, M; De Lorenzo, G; Puigdengoles, C; Cabruja, E; Calderón, Y; Kolstein, M; Macias-Montero, J G; Martinez, R; Mikhaylova, E; Uzun, D

    2013-02-01

    We report on the characterization of 2 mm thick CdTe diode detector with Schottky contacts to be employed in a novel conceptual design of PET scanner. Results at -8°C with an applied bias voltage of -1000 V/mm show a 1.2% FWHM energy resolution at 511 keV. Coincidence time resolution has been measured by triggering on the preamplifier output signal to improve the timing resolution of the detector. Results at the same bias and temperature conditions show a FWHM of 6 ns with a minimum acceptance energy of 500 keV. These results show that pixelated CdTe Schottky diode is an excellent candidate for the development of next generation nuclear medical imaging devices such as PET, Compton gamma cameras, and especially PET-MRI hybrid systems when used in a magnetic field immune configuration.

  16. Energy and coincidence time resolution measurements of CdTe detectors for PET

    PubMed Central

    Ariño, G.; Chmeissani, M.; De Lorenzo, G.; Puigdengoles, C.; Cabruja, E.; Calderón, Y.; Kolstein, M.; Macias-Montero, J.G.; Martinez, R.; Mikhaylova, E.; Uzun, D.

    2013-01-01

    We report on the characterization of 2 mm thick CdTe diode detector with Schottky contacts to be employed in a novel conceptual design of PET scanner. Results at −8°C with an applied bias voltage of −1000 V/mm show a 1.2% FWHM energy resolution at 511 keV. Coincidence time resolution has been measured by triggering on the preamplifier output signal to improve the timing resolution of the detector. Results at the same bias and temperature conditions show a FWHM of 6 ns with a minimum acceptance energy of 500 keV. These results show that pixelated CdTe Schottky diode is an excellent candidate for the development of next generation nuclear medical imaging devices such as PET, Compton gamma cameras, and especially PET-MRI hybrid systems when used in a magnetic field immune configuration. PMID:23750177

  17. Energy and coincidence time resolution measurements of CdTe detectors for PET

    NASA Astrophysics Data System (ADS)

    Ariño, G.; Chmeissani, M.; De Lorenzo, G.; Puigdengoles, C.; Cabruja, E.; Calderón, Y.; Kolstein, M.; Macias-Montero, J. G.; Martinez, R.; Mikhaylova, E.; Uzun, D.

    2013-02-01

    We report on the characterization of 2 mm thick CdTe diode detector with Schottky contacts to be employed in a novel conceptual design of PET scanner. Results at -8°C with an applied bias voltage of -1000 V/mm show a 1.2% FWHM energy resolution at 511 keV. Coincidence time resolution has been measured by triggering on the preamplifier output signal to improve the timing resolution of the detector. Results at the same bias and temperature conditions show a FWHM of 6 ns with a minimum acceptance energy of 500 keV. These results show that pixelated CdTe Schottky diode is an excellent candidate for the development of next generation nuclear medical imaging devices such as PET, Compton gamma cameras, and especially PET-MRI hybrid systems when used in a magnetic field immune configuration.

  18. Nutritional sustainability of pet foods.

    PubMed

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

    2013-03-01

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

  19. PET Imaging in Huntington's Disease.

    PubMed

    Roussakis, Andreas-Antonios; Piccini, Paola

    2015-01-01

    To date, little is known about how neurodegeneration and neuroinflammation propagate in Huntington's disease (HD). Unfortunately, no treatment is available to cure or reverse the progressive decline of function caused by the disease, thus considering HD a fatal disease. Mutation gene carriers typically remain asymptomatic for many years although alterations in the basal ganglia and cortex occur early on in mutant HD gene-carriers. Positron Emission Tomography (PET) is a functional imaging technique of nuclear medicine which enables in vivo visualization of numerous biological molecules expressed in several human tissues. Brain PET is most powerful to study in vivo neuronal and glial cells function as well as cerebral blood flow in a plethora of neurodegenerative disorders including Parkinson's disease, Alzheimer's and HD. In absence of HD-specific biomarkers for monitoring disease progression, previous PET studies in HD were merely focused on the study of dopaminergic terminals, cerebral blood flow and glucose metabolism in manifest and premanifest HD-gene carriers. More recently, research interest has been exploring novel PET targets in HD including the state of phosphodiesterse expression and the role of activated microglia. Hence, a better understanding of the HD pathogenesis mechanisms may lead to the development of targeted therapies. PET imaging follow-up studies with novel selective PET radiotracers such as 11C-IMA-107 and 11C-PBR28 may provide insight on disease progression and identify prognostic biomarkers, elucidate the underlying HD pathology and assess novel pharmaceutical agents and over time.

  20. Passive auto-focus for digital still cameras and camera phones: Filter-switching and low-light techniques

    NASA Astrophysics Data System (ADS)

    Gamadia, Mark Noel

    In order to gain valuable market share in the growing consumer digital still camera and camera phone market, camera manufacturers have to continually add and improve existing features to their latest product offerings. Auto-focus (AF) is one such feature, whose aim is to enable consumers to quickly take sharply focused pictures with little or no manual intervention in adjusting the camera's focus lens. While AF has been a standard feature in digital still and cell-phone cameras, consumers often complain about their cameras' slow AF performance, which may lead to missed photographic opportunities, rendering valuable moments and events with undesired out-of-focus pictures. This dissertation addresses this critical issue to advance the state-of-the-art in the digital band-pass filter, passive AF method. This method is widely used to realize AF in the camera industry, where a focus actuator is adjusted via a search algorithm to locate the in-focus position by maximizing a sharpness measure extracted from a particular frequency band of the incoming image of the scene. There are no known systematic methods for automatically deriving the parameters such as the digital pass-bands or the search step-size increments used in existing passive AF schemes. Conventional methods require time consuming experimentation and tuning in order to arrive at a set of parameters which balance AF performance in terms of speed and accuracy ultimately causing a delay in product time-to-market. This dissertation presents a new framework for determining an optimal set of passive AF parameters, named Filter- Switching AF, providing an automatic approach to achieve superior AF performance, both in good and low lighting conditions based on the following performance measures (metrics): speed (total number of iterations), accuracy (offset from truth), power consumption (total distance moved), and user experience (in-focus position overrun). Performance results using three different prototype cameras

  1. 3D measurement and camera attitude estimation method based on trifocal tensor

    NASA Astrophysics Data System (ADS)

    Chen, Shengyi; Liu, Haibo; Yao, Linshen; Yu, Qifeng

    2016-11-01

    To simultaneously perform 3D measurement and camera attitude estimation, an efficient and robust method based on trifocal tensor is proposed in this paper, which only employs the intrinsic parameters and positions of three cameras. The initial trifocal tensor is obtained by using heteroscedastic errors-in-variables (HEIV) estimator and the initial relative poses of the three cameras is acquired by decomposing the tensor. Further the initial attitude of the cameras is obtained with knowledge of the three cameras' positions. Then the camera attitude and the interested points' image positions are optimized according to the constraint of trifocal tensor with the HEIV method. Finally the spatial positions of the points are obtained by using intersection measurement method. Both simulation and real image experiment results suggest that the proposed method achieves the same precision of the Bundle Adjustment (BA) method but be more efficient.

  2. Towards the Implementation of an Autonomous Camera Algorithm on the da Vinci Platform.

    PubMed

    Eslamian, Shahab; Reisner, Luke A; King, Brady W; Pandya, Abhilash K

    2016-01-01

    Camera positioning is critical for all telerobotic surgical systems. Inadequate visualization of the remote site can lead to serious errors that can jeopardize the patient. An autonomous camera algorithm has been developed on a medical robot (da Vinci) simulator. It is found to be robust in key scenarios of operation. This system behaves with predictable and expected actions for the camera arm with respect to the tool positions. The implementation of this system is described herein. The simulation closely models the methodology needed to implement autonomous camera control in a real hardware system. The camera control algorithm follows three rules: (1) keep the view centered on the tools, (2) keep the zoom level optimized such that the tools never leave the field of view, and (3) avoid unnecessary movement of the camera that may distract/disorient the surgeon. Our future work will apply this algorithm to the real da Vinci hardware.

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

    DTIC Science & Technology

    2010-07-01

    principle all that will be necessary is to redesign the logic interface boards to the FPGA module that supply and sequence all control signals, rewrite...PCI Interface CAEN V785 ADC CAEN V1495 FPGA Module Logic converter boards BGO triggers (24) BGO analog out (96) GATE BGO amps...with external “coincidence” Anger cameras in use for PET at the time [1]. The primary focus of the application was for single photon tracers but it

  4. Toward a miniaturized fundus camera.

    PubMed

    Gliss, Christine; Parel, Jean-Marie; Flynn, John T; Pratisto, Hans; Niederer, Peter

    2004-01-01

    Retinopathy of prematurity (ROP) describes a pathological development of the retina in prematurely born children. In order to prevent severe permanent damage to the eye and enable timely treatment, the fundus of the eye in such children has to be examined according to established procedures. For these examinations, our miniaturized fundus camera is intended to allow the acquisition of wide-angle digital pictures of the fundus for on-line or off-line diagnosis and documentation. We designed two prototypes of a miniaturized fundus camera, one with graded refractive index (GRIN)-based optics, the other with conventional optics. Two different modes of illumination were compared: transscleral and transpupillary. In both systems, the size and weight of the camera were minimized. The prototypes were tested on young rabbits. The experiments led to the conclusion that the combination of conventional optics with transpupillary illumination yields the best results in terms of overall image quality.

  5. Cameras for semiconductor process control

    NASA Technical Reports Server (NTRS)

    Porter, W. A.; Parker, D. L.

    1977-01-01

    The application of X-ray topography to semiconductor process control is described, considering the novel features of the high speed camera and the difficulties associated with this technique. The most significant results on the effects of material defects on device performance are presented, including results obtained using wafers processed entirely within this institute. Defects were identified using the X-ray camera and correlations made with probe data. Also included are temperature dependent effects of material defects. Recent applications and improvements of X-ray topographs of silicon-on-sapphire and gallium arsenide are presented with a description of a real time TV system prototype and of the most recent vacuum chuck design. Discussion is included of our promotion of the use of the camera by various semiconductor manufacturers.

  6. Camera-on-a-Chip

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Jet Propulsion Laboratory's research on a second generation, solid-state image sensor technology has resulted in the Complementary Metal- Oxide Semiconductor Active Pixel Sensor (CMOS), establishing an alternative to the Charged Coupled Device (CCD). Photobit Corporation, the leading supplier of CMOS image sensors, has commercialized two products of their own based on this technology: the PB-100 and PB-300. These devices are cameras on a chip, combining all camera functions. CMOS "active-pixel" digital image sensors offer several advantages over CCDs, a technology used in video and still-camera applications for 30 years. The CMOS sensors draw less energy, they use the same manufacturing platform as most microprocessors and memory chips, and they allow on-chip programming of frame size, exposure, and other parameters.

  7. Dark Energy Camera for Blanco

    SciTech Connect

    Binder, Gary A.; /Caltech /SLAC

    2010-08-25

    In order to make accurate measurements of dark energy, a system is needed to monitor the focus and alignment of the Dark Energy Camera (DECam) to be located on the Blanco 4m Telescope for the upcoming Dark Energy Survey. One new approach under development is to fit out-of-focus star images to a point spread function from which information about the focus and tilt of the camera can be obtained. As a first test of a new algorithm using this idea, simulated star images produced from a model of DECam in the optics software Zemax were fitted. Then, real images from the Mosaic II imager currently installed on the Blanco telescope were used to investigate the algorithm's capabilities. A number of problems with the algorithm were found, and more work is needed to understand its limitations and improve its capabilities so it can reliably predict camera alignment and focus.

  8. The GISMO-2 Bolometer Camera

    NASA Technical Reports Server (NTRS)

    Staguhn, Johannes G.; Benford, Dominic J.; Fixsen, Dale J.; Hilton, Gene; Irwin, Kent D.; Jhabvala, Christine A.; Kovacs, Attila; Leclercq, Samuel; Maher, Stephen F.; Miller, Timothy M.; Moseley, Samuel H.; Sharp, Elemer H.; Wollack, Edward J.

    2012-01-01

    We present the concept for the GISMO-2 bolometer camera) which we build for background-limited operation at the IRAM 30 m telescope on Pico Veleta, Spain. GISM0-2 will operate Simultaneously in the 1 mm and 2 mm atmospherical windows. The 1 mm channel uses a 32 x 40 TES-based Backshort Under Grid (BUG) bolometer array, the 2 mm channel operates with a 16 x 16 BUG array. The camera utilizes almost the entire full field of view provided by the telescope. The optical design of GISM0-2 was strongly influenced by our experience with the GISMO 2 mm bolometer camera which is successfully operating at the 30m telescope. GISMO is accessible to the astronomical community through the regular IRAM call for proposals.

  9. SU-C-9A-06: The Impact of CT Image Used for Attenuation Correction in 4D-PET

    SciTech Connect

    Cui, Y; Bowsher, J; Yan, S; Cai, J; Das, S; Yin, F

    2014-06-01

    Purpose: To evaluate the appropriateness of using 3D non-gated CT image for attenuation correction (AC) in a 4D-PET (gated PET) imaging protocol used in radiotherapy treatment planning simulation. Methods: The 4D-PET imaging protocol in a Siemens PET/CT simulator (Biograph mCT, Siemens Medical Solutions, Hoffman Estates, IL) was evaluated. CIRS Dynamic Thorax Phantom (CIRS Inc., Norfolk, VA) with a moving glass sphere (8 mL) in the middle of its thorax portion was used in the experiments. The glass was filled with {sup 18}F-FDG and was in a longitudinal motion derived from a real patient breathing pattern. Varian RPM system (Varian Medical Systems, Palo Alto, CA) was used for respiratory gating. Both phase-gating and amplitude-gating methods were tested. The clinical imaging protocol was modified to use three different CT images for AC in 4D-PET reconstruction: first is to use a single-phase CT image to mimic actual clinical protocol (single-CT-PET); second is to use the average intensity projection CT (AveIP-CT) derived from 4D-CT scanning (AveIP-CT-PET); third is to use 4D-CT image to do the phase-matched AC (phase-matching- PET). Maximum SUV (SUVmax) and volume of the moving target (glass sphere) with threshold of 40% SUVmax were calculated for comparison between 4D-PET images derived with different AC methods. Results: The SUVmax varied 7.3%±6.9% over the breathing cycle in single-CT-PET, compared to 2.5%±2.8% in AveIP-CT-PET and 1.3%±1.2% in phasematching PET. The SUVmax in single-CT-PET differed by up to 15% from those in phase-matching-PET. The target volumes measured from single- CT-PET images also presented variations up to 10% among different phases of 4D PET in both phase-gating and amplitude-gating experiments. Conclusion: Attenuation correction using non-gated CT in 4D-PET imaging is not optimal process for quantitative analysis. Clinical 4D-PET imaging protocols should consider phase-matched 4D-CT image if available to achieve better accuracy.

  10. Radiometric performance of the Viking Mars lander cameras

    NASA Technical Reports Server (NTRS)

    Huck, F. O.; Burcher, E. E.; Taylor, E. J.; Wall, S. D.

    1975-01-01

    The Viking lander cameras feature an array of 12 silicon photodiodes for electronic focus selection and multispectral imaging. Comparisons of absolute radiometric calibrations of the four cameras selected for the mission to Mars with performance predictions based on their design data revealed minor discrepancies. These discrepancies were caused primarily by the method used to calibrate the photosensor array and apparently also from light reflections internal to the array. The sensitivity and dynamic range of all camera channels are found to be sufficient for high quality pictures, providing that the commandable gains and offsets can be optimized for the scene radiance; otherwise, the quantization noise may be too high or the dynamic range too low for an adequate characterization of the scene.

  11. Angular distance constraints calibration for outdoor zoom camera.

    PubMed

    Zheng, Xuehan; Wei, Zhenzhong; Zhang, Guangjun

    2016-10-17

    Based on 2-D protractor property of camera, we proposed a flexible calibration method for zoom camera that used outdoors. It only requires the camera to observe control points once for given zooming settings, when there are several control points at infinity and known the angular distances. Under constraints of image points, the angular distance between their re-projecting vectors and the image of absolute conic (IAC), nonlinear optimization is used to solve parameters of IAC. Then IAC can be uniquely decomposed by the Cholesky factorization, and consequently the intrinsic parameters can be obtained. Towards the factors that affect the accuracy of the calibration, theoretical analysis and computer simulation are carried out respectively consequence in qualitative analysis and quantitative result. On the issues of inaccuracy of principal point, the zooming center is selected to improve the accuracy of calibration. Real data demonstrated the effectiveness of the techniques.

  12. SFDT-1 Camera Pointing and Sun-Exposure Analysis and Flight Performance

    NASA Technical Reports Server (NTRS)

    White, Joseph; Dutta, Soumyo; Striepe, Scott

    2015-01-01

    The Supersonic Flight Dynamics Test (SFDT) vehicle was developed to advance and test technologies of NASA's Low Density Supersonic Decelerator (LDSD) Technology Demonstration Mission. The first flight test (SFDT-1) occurred on June 28, 2014. In order to optimize the usefulness of the camera data, analysis was performed to optimize parachute visibility in the camera field of view during deployment and inflation and to determine the probability of sun-exposure issues with the cameras given the vehicle heading and launch time. This paper documents the analysis, results and comparison with flight video of SFDT-1.

  13. PSMA PET and Radionuclide Therapy in Prostate Cancer.

    PubMed

    Bouchelouche, Kirsten; Turkbey, Baris; Choyke, Peter L

    2016-11-01

    Prostate cancer (PCa) is the most common malignancy in men and a major cause of cancer death. Accurate imaging plays an important role in diagnosis, staging, restaging, detection of biochemical recurrence, and for therapy of patients with PCa. Because no effective treatment is available for advanced PCa, there is an urgent need to develop new and more effective therapeutic strategies. To optimize treatment outcome, especially in high-risk patients with PCa, therapy for PCa is moving rapidly toward personalization. Medical imaging, including positron emission tomography (PET)/computed tomography (CT), plays an important role in personalized medicine in oncology. In the recent years, much focus has been on prostate-specific membrane antigen (PSMA) as a promising target for imaging and therapy with radionuclides, as it is upregulated in most PCa. In the prostate, one potential role for PSMA PET imaging is to help guide focal therapy. Several studies have shown great potential of PSMA PET/CT for initial staging, lymph node staging, and detection of recurrence of PCa, even at very low prostate-specific antigen values after primary therapy. Furthermore, studies have shown that PSMA PET/CT has a higher detection rate than choline PET/CT. Radiolabeled PSMA ligands for therapy show promise in several studies with metastatic PCa and is an area of active investigation. The "image and treat" strategy, with radiolabeled PSMA ligands, has the potential to improve the treatment outcome of patients with PCa and is paving the way for precision medicine in PCa. The aim of this review is to give an overview of recent advancement in PSMA PET and radionuclide therapy for PCa.

  14. Parasites, pets, and people.

    PubMed

    Marx, M B

    1991-03-01

    It is important for the family physician to understand that patients' relationships with their pets play an important role in helping maintain mental and physical health yet provide the potential for causing illness in the patient. Toxocara canis (dog roundworm) and Toxocara cati (cat roundworm) are the ascarids most commonly responsible for VLM and ocular larva migrans in humans. These roundworms live in their adult stage in the small intestine of the dog and cat where their eggs are passed in the feces. The eggs containing the infective larva are very sticky, thus an infant crawling around on the floor can easily pick these up on fingers that almost invariably end up in the mouth. Infections are usually mild and asymptomatic but with a persistent eosinophilia. Ocular larva migrans is the form usually occurring in older children and adults. Some public health veterinarians recommend that a puppy or kitten should not be obtained as a companion for a child who is not old enough to read, thus bypassing the crawling and toddler stages. Hookworm eggs, shed in the feces of infected dogs or cats, develop into the infective second stage within a week. Humans are usually infected when bare areas of skin such as bare feet or the torso come in contact with soil contaminated with the larvae. The second-stage larvae are able to penetrate the intact skin of humans and the foot pads of dogs and cats. In the United States, the common dog hookworm, A. caninum, is a widespread parasite. Human intestinal ancylostomiasis caused by this species is rare, with only six cases recorded in the literature. Infection in humans or animals by the common tapeworm of dogs and cats (Dipylidium caninum) requires ingestion of the intermediate host, the dog or cat flea containing the larva (cysticercoids) of the agent. Many cases in humans are asymptomatic. Dipylidiasis affects mainly infants and young children who may swallow a flea that hops up while the infant is crawling on the floor or fondling

  15. Astronomical observations with an infrared array camera

    SciTech Connect

    Tresch-Fienberg, R.M.

    1985-01-01

    Astronomical observations with an infrared array camera demonstrate that arrays are excellent for high spatial resolution photometric mapping of celestial objects. The author describes a a 16 x 16 pixel array camera system based on a bismuth-doped silicon charge injection device optimized for use in the 8-13 micron atmospheric window. Observing techniques and image processing algorithms that are unique to the use of an array detector are also discussed. Multi-wavelength, 1-2 arcsec resolution images of three different celestial objects are presented. For the galactic center, maps of the infrared color temperature and emission optical depth are derived. The results are consistent with a model in which a low density region with a massive luminosity source at its center is encircled by a ring of gas and dust from which material may be infalling toward the nucleus. Multiple luminosity sources are not required to explain the infrared appearance of the galactic center. Images of Seyfert galaxy NGC 1068 are the first to resolve the infrared structure of the nucleus and show that it is similar to that at optical and radio wavelengths. Infrared emission extended northeast of the nucleus is identified with the radio jet. Combined with optical spectra and charge coupled device images, the new data imply a causal relationship between the Seyfert activity in the nucleus and the starburst in the disk.

  16. Parasites in pet reptiles.

    PubMed

    Rataj, Aleksandra Vergles; Lindtner-Knific, Renata; Vlahović, Ksenija; Mavri, Urška; Dovč, Alenka

    2011-05-30

    Exotic reptiles originating from the wild can be carriers of many different pathogens and some of them can infect humans. Reptiles imported into Slovenia from 2000 to 2005, specimens of native species taken from the wild and captive bred species were investigated. A total of 949 reptiles (55 snakes, 331 lizards and 563 turtles), belonging to 68 different species, were examined for the presence of endoparasites and ectoparasites. Twelve different groups (Nematoda (5), Trematoda (1), Acanthocephala (1), Pentastomida (1) and Protozoa (4)) of endoparasites were determined in 26 (47.3%) of 55 examined snakes. In snakes two different species of ectoparasites were also found. Among the tested lizards eighteen different groups (Nematoda (8), Cestoda (1), Trematoda (1), Acanthocephala (1), Pentastomida (1) and Protozoa (6)) of endoparasites in 252 (76.1%) of 331 examined animals were found. One Trombiculid ectoparasite was determined. In 563 of examined turtles eight different groups (Nematoda (4), Cestoda (1), Trematoda (1) and Protozoa (2)) of endoparasites were determined in 498 (88.5%) animals. In examined turtles three different species of ectoparasites were seen. The established prevalence of various parasites in reptiles used as pet animals indicates the need for examination on specific pathogens prior to introduction to owners.

  17. Parasites in pet reptiles

    PubMed Central

    2011-01-01

    Exotic reptiles originating from the wild can be carriers of many different pathogens and some of them can infect humans. Reptiles imported into Slovenia from 2000 to 2005, specimens of native species taken from the wild and captive bred species were investigated. A total of 949 reptiles (55 snakes, 331 lizards and 563 turtles), belonging to 68 different species, were examined for the presence of endoparasites and ectoparasites. Twelve different groups (Nematoda (5), Trematoda (1), Acanthocephala (1), Pentastomida (1) and Protozoa (4)) of endoparasites were determined in 26 (47.3%) of 55 examined snakes. In snakes two different species of ectoparasites were also found. Among the tested lizards eighteen different groups (Nematoda (8), Cestoda (1), Trematoda (1), Acanthocephala (1), Pentastomida (1) and Protozoa (6)) of endoparasites in 252 (76.1%) of 331 examined animals were found. One Trombiculid ectoparasite was determined. In 563 of examined turtles eight different groups (Nematoda (4), Cestoda (1), Trematoda (1) and Protozoa (2)) of endoparasites were determined in 498 (88.5%) animals. In examined turtles three different species of ectoparasites were seen. The established prevalence of various parasites in reptiles used as pet animals indicates the need for examination on specific pathogens prior to introduction to owners. PMID:21624124

  18. Visible camera imaging of plasmas in Proto-MPEX

    NASA Astrophysics Data System (ADS)

    Mosby, R.; Skeen, C.; Biewer, T. M.; Renfro, R.; Ray, H.; Shaw, G. C.

    2015-11-01

    The prototype Material Plasma Exposure eXperiment (Proto-MPEX) is a linear plasma device being developed at Oak Ridge National Laboratory (ORNL). This machine plans to study plasma-material interaction (PMI) physics relevant to future fusion reactors. Measurements of plasma light emission will be made on Proto-MPEX using fast, visible framing cameras. The cameras utilize a global shutter, which allows a full frame image of the plasma to be captured and compared at multiple times during the plasma discharge. Typical exposure times are ~10-100 microseconds. The cameras are capable of capturing images at up to 18,000 frames per second (fps). However, the frame rate is strongly dependent on the size of the ``region of interest'' that is sampled. The maximum ROI corresponds to the full detector area, of ~1000x1000 pixels. The cameras have an internal gain, which controls the sensitivity of the 10-bit detector. The detector includes a Bayer filter, for ``true-color'' imaging of the plasma emission. This presentation will exmine the optimized camera settings for use on Proto-MPEX. This work was supported by the US. D.O.E. contract DE-AC05-00OR22725.

  19. "Stereo Compton cameras" for the 3-D localization of radioisotopes

    NASA Astrophysics Data System (ADS)

    Takeuchi, K.; Kataoka, J.; Nishiyama, T.; Fujita, T.; Kishimoto, A.; Ohsuka, S.; Nakamura, S.; Adachi, S.; Hirayanagi, M.; Uchiyama, T.; Ishikawa, Y.; Kato, T.

    2014-11-01

    The Compton camera is a viable and convenient tool used to visualize the distribution of radioactive isotopes that emit gamma rays. After the nuclear disaster in Fukushima in 2011, there is a particularly urgent need to develop "gamma cameras", which can visualize the distribution of such radioisotopes. In response, we propose a portable Compton camera, which comprises 3-D position-sensitive GAGG scintillators coupled with thin monolithic MPPC arrays. The pulse-height ratio of two MPPC-arrays allocated at both ends of the scintillator block determines the depth of interaction (DOI), which dramatically improves the position resolution of the scintillation detectors. We report on the detailed optimization of the detector design, based on Geant4 simulation. The results indicate that detection efficiency reaches up to 0.54%, or more than 10 times that of other cameras being tested in Fukushima, along with a moderate angular resolution of 8.1° (FWHM). By applying the triangular surveying method, we also propose a new concept for the stereo measurement of gamma rays by using two Compton cameras, thus enabling the 3-D positional measurement of radioactive isotopes for the first time. From one point source simulation data, we ensured that the source position and the distance to the same could be determined typically to within 2 meters' accuracy and we also confirmed that more than two sources are clearly separated by the event selection from two point sources of simulation data.

  20. Keeping a pan-tilt-zoom camera calibrated.

    PubMed

    Wu, Ziyan; Radke, Richard J

    2013-08-01

    Pan-tilt-zoom (PTZ) cameras are pervasive in modern surveillance systems. However, we demonstrate that the (pan, tilt) coordinates reported by PTZ cameras become inaccurate after many hours of operation, endangering tracking and 3D localization algorithms that rely on the accuracy of such values. To solve this problem, we propose a complete model for a PTZ camera that explicitly reflects how focal length and lens distortion vary as a function of zoom scale. We show how the parameters of this model can be quickly and accurately estimated using a series of simple initialization steps followed by a nonlinear optimization. Our method requires only 10 images to achieve accurate calibration results. Next, we show how the calibration parameters can be maintained using a one-shot dynamic correction process; this ensures that the camera returns the same field of view every time the user requests a given (pan, tilt, zoom), even after hundreds of hours of operation. The dynamic calibration algorithm is based on matching the current image against a stored feature library created at the time the PTZ camera is mounted. We evaluate the calibration and dynamic correction algorithms on both experimental and real-world datasets, demonstrating the effectiveness of the techniques.

  1. Full Stokes polarization imaging camera

    NASA Astrophysics Data System (ADS)

    Vedel, M.; Breugnot, S.; Lechocinski, N.

    2011-10-01

    Objective and background: We present a new version of Bossa Nova Technologies' passive polarization imaging camera. The previous version was performing live measurement of the Linear Stokes parameters (S0, S1, S2), and its derivatives. This new version presented in this paper performs live measurement of Full Stokes parameters, i.e. including the fourth parameter S3 related to the amount of circular polarization. Dedicated software was developed to provide live images of any Stokes related parameters such as the Degree Of Linear Polarization (DOLP), the Degree Of Circular Polarization (DOCP), the Angle Of Polarization (AOP). Results: We first we give a brief description of the camera and its technology. It is a Division Of Time Polarimeter using a custom ferroelectric liquid crystal cell. A description of the method used to calculate Data Reduction Matrix (DRM)5,9 linking intensity measurements and the Stokes parameters is given. The calibration was developed in order to maximize the condition number of the DRM. It also allows very efficient post processing of the images acquired. Complete evaluation of the precision of standard polarization parameters is described. We further present the standard features of the dedicated software that was developed to operate the camera. It provides live images of the Stokes vector components and the usual associated parameters. Finally some tests already conducted are presented. It includes indoor laboratory and outdoor measurements. This new camera will be a useful tool for many applications such as biomedical, remote sensing, metrology, material studies, and others.

  2. Stratoscope 2 integrating television camera

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The development, construction, test and delivery of an integrating television camera for use as the primary data sensor on Flight 9 of Stratoscope 2 is described. The system block diagrams are presented along with the performance data, and definition of the interface of the telescope with the power, telemetry, and communication system.

  3. OSIRIS camera barrel optomechanical design

    NASA Astrophysics Data System (ADS)

    Farah, Alejandro; Tejada, Carlos; Gonzalez, Jesus; Cobos, Francisco J.; Sanchez, Beatriz; Fuentes, Javier; Ruiz, Elfego

    2004-09-01

    A Camera Barrel, located in the OSIRIS imager/spectrograph for the Gran Telescopio Canarias (GTC), is described in this article. The barrel design has been developed by the Institute for Astronomy of the University of Mexico (IA-UNAM), in collaboration with the Institute for Astrophysics of Canarias (IAC), Spain. The barrel is being manufactured by the Engineering Center for Industrial Development (CIDESI) at Queretaro, Mexico. The Camera Barrel includes a set of eight lenses (three doublets and two singlets), with their respective supports and cells, as well as two subsystems: the Focusing Unit, which is a mechanism that modifies the first doublet relative position; and the Passive Displacement Unit (PDU), which uses the third doublet as thermal compensator to maintain the camera focal length and image quality when the ambient temperature changes. This article includes a brief description of the scientific instrument; describes the design criteria related with performance justification; and summarizes the specifications related with misalignment errors and generated stresses. The Camera Barrel components are described and analytical calculations, FEA simulations and error budgets are also included.

  4. Measuring Distances Using Digital Cameras

    ERIC Educational Resources Information Center

    Kendal, Dave

    2007-01-01

    This paper presents a generic method of calculating accurate horizontal and vertical object distances from digital images taken with any digital camera and lens combination, where the object plane is parallel to the image plane or tilted in the vertical plane. This method was developed for a project investigating the size, density and spatial…

  5. The Camera Comes to Court.

    ERIC Educational Resources Information Center

    Floren, Leola

    After the Lindbergh kidnapping trial in 1935, the American Bar Association sought to eliminate electronic equipment from courtroom proceedings. Eventually, all but two states adopted regulations applying that ban to some extent, and a 1965 Supreme Court decision encouraged the banning of television cameras at trials as well. Currently, some states…

  6. High speed multiwire photon camera

    NASA Technical Reports Server (NTRS)

    Lacy, Jeffrey L. (Inventor)

    1991-01-01

    An improved multiwire proportional counter camera having particular utility in the field of clinical nuclear medicine imaging. The detector utilizes direct coupled, low impedance, high speed delay lines, the segments of which are capacitor-inductor networks. A pile-up rejection test is provided to reject confused events otherwise caused by multiple ionization events occuring during the readout window.

  7. High speed multiwire photon camera

    NASA Technical Reports Server (NTRS)

    Lacy, Jeffrey L. (Inventor)

    1989-01-01

    An improved multiwire proportional counter camera having particular utility in the field of clinical nuclear medicine imaging. The detector utilizes direct coupled, low impedance, high speed delay lines, the segments of which are capacitor-inductor networks. A pile-up rejection test is provided to reject confused events otherwise caused by multiple ionization events occurring during the readout window.

  8. Directing Performers for the Cameras.

    ERIC Educational Resources Information Center

    Wilson, George P., Jr.

    An excellent way for an undergraduate, novice director of television and film to pick up background experience in directing performers for cameras is by participating in nonbroadcast-film activities, such as theatre, dance, and variety acts, both as performer and as director. This document describes the varieties of activities, including creative,…

  9. Toy Cameras and Color Photographs.

    ERIC Educational Resources Information Center

    Speight, Jerry

    1979-01-01

    The technique of using toy cameras for both black-and-white and color photography in the art class is described. The author suggests that expensive equipment can limit the growth of a beginning photographer by emphasizing technique and equipment instead of in-depth experience with composition fundamentals and ideas. (KC)

  10. Retinal oximetry with a multiaperture camera

    NASA Astrophysics Data System (ADS)

    Lemaillet, Paul; Lompado, Art; Ibrahim, Mohamed; Nguyen, Quan Dong; Ramella-Roman, Jessica C.

    2010-02-01

    Oxygen saturation measurements in the retina is an essential measurement in monitoring eye health of diabetic patient. In this paper, preliminary result of oxygen saturation measurements for a healthy patient retina is presented. The retinal oximeter used is based on a regular fundus camera to which was added an optimized optical train designed to perform aperture division whereas a filter array help select the requested wavelengths. Hence, nine equivalent wavelength-dependent sub-images are taken in a snapshot which helps minimizing the effects of eye movements. The setup is calibrated by using a set of reflectance calibration phantoms and a lookuptable (LUT) is computed. An inverse model based on the LUT is presented to extract the optical properties of a patient fundus and further estimate the oxygen saturation in a retina vessel.

  11. Initial Characterization of a Dedicated Breast PET/CT Scanner During Human Imaging

    PubMed Central

    Bowen, Spencer L.; Wu, Yibao; Chaudhari, Abhijit J.; Fu, Lin; Packard, Nathan J.; Burkett, George W.; Yang, Kai; Lindfors, Karen K.; Shelton, David K.; Hagge, Rosalie; Borowsky, Alexander D.; Martinez, Steve R.; Qi, Jinyi; Boone, John M.; Cherry, Simon R.; Badawi, Ramsey D.

    2010-01-01

    We have constructed a dedicated breast PET/CT scanner capable of high-resolution functional and anatomic imaging. Here, we present an initial characterization of scanner performance during patient imaging. Methods The system consisted of a lutetium oxyorthosilicate–based dual–planar head PET camera (crystal size, 3 × 3 × 20 mm) and 768-slice cone-beam CT. The position of the PET heads (separation and height) could be adjusted for varying breast dimensions. For scanning, the patient lay prone on a specialized bed and inserted a single pendent breast through an aperture in the table top. Compression of the breast as used in mammography is not required. PET and CT systems rotate in the coronal plane underneath the patient sequentially to collect fully tomographic datasets. PET images were reconstructed with the fully 3-dimensional maximum a posteriori method, and CT images were reconstructed with the Feldkamp algorithm, then spatially registered and fused for display. Phantom scans were obtained to assess the registration accuracy between PET and CT images and the influence of PET electronics and activity on CT image quality. We imaged 4 women with mammographic findings highly suggestive of breast cancer (breast imaging reporting and data system, category 5) in an ongoing clinical trial. Patients were injected with 18F-FDG and imaged for 12.5 min per breast. From patient data, noise-equivalent counting rates and the singles-to-trues ratio (a surrogate for the randoms fraction) were calculated. Results The average registration error between PET and CT images was 0.18 mm. PET electronics and activity did not significantly affect CT image quality. For the patient trial, biopsy-confirmed cancers were visualized on dedicated breast PET/CT on all patient scans, including the detection of ductal carcinoma in situ in 1 case. The singles-to-trues ratio was found to be inversely correlated with breast volume in the field of view, suggesting that larger breasts trend

  12. Quantitative PET imaging with the 3T MR-BrainPET

    NASA Astrophysics Data System (ADS)

    Weirich, C.; Scheins, J.; Lohmann, P.; Tellmann, L.; Byars, L.; Michel, C.; Rota Kops, E.; Brenner, D.; Herzog, H.; Shah, N. J.

    2013-02-01

    The new hybrid imaging technology of MR-PET allows for simultaneous acquisition of versatile MRI contrasts and the quantitative metabolic imaging with PET. In order to achieve the quantification of PET images with minimal residual error the application of several corrections is crucial. In this work we present our results on quantification with the 3T MR BrainPET scanner.

  13. Exercises in PET Image Reconstruction

    NASA Astrophysics Data System (ADS)

    Nix, Oliver

    These exercises are complementary to the theoretical lectures about positron emission tomography (PET) image reconstruction. They aim at providing some hands on experience in PET image reconstruction and focus on demonstrating the different data preprocessing steps and reconstruction algorithms needed to obtain high quality PET images. Normalisation, geometric-, attenuation- and scatter correction are introduced. To explain the necessity of those some basics about PET scanner hardware, data acquisition and organisation are reviewed. During the course the students use a software application based on the STIR (software for tomographic image reconstruction) library 1,2 which allows them to dynamically select or deselect corrections and reconstruction methods as well as to modify their most important parameters. Following the guided tutorial, the students get an impression on the effect the individual data precorrections have on image quality and what happens if they are forgotten. Several data sets in sinogram format are provided, such as line source data, Jaszczak phantom data sets with high and low statistics and NEMA whole body phantom data. The two most frequently used reconstruction algorithms in PET image reconstruction, filtered back projection (FBP) and the iterative OSEM (ordered subset expectation maximation) approach are used to reconstruct images. The exercise should help the students gaining an understanding what the reasons for inferior image quality and artefacts are and how to improve quality by a clever choice of reconstruction parameters.

  14. Recent Understandings of Pet Allergies

    PubMed Central

    Ownby, Dennis; Johnson, Christine Cole

    2016-01-01

    Allergic reactions to pets have been recognized for at least a hundred years. Yet our understanding of the effects of all of the interactions between pet exposures and human immune responses continues to grow. Allergists, epidemiologists, and immunologists have spent years trying to better understand how exposures to pet allergens lead to allergic sensitization (the production of allergen-specific immunoglobulin class E [IgE] antibodies) and subsequent allergic disease. A major new development in this understanding is the recognition that pet exposures consist of not only allergen exposures but also changes in microbial exposures. Exposures to certain pet-associated microbes, especially in the neonatal period, appear to be able to dramatically alter how a child’s immune system develops and this in turn reduces the risk of allergic sensitization and disease. An exciting challenge in the next few years will be to see whether these changes can be developed into a realistic preventative strategy with the expectation of significantly reducing allergic disease, especially asthma. PMID:26918180

  15. Potentially Dangerous Items for Your Pet

    MedlinePlus

    ... Animal & Veterinary Home Animal & Veterinary Resources for ... our homes to keep young children safe, but what about “pet proofing” our homes too? Many edible and non-edible dangers for your pet may exist in or around ...

  16. Dual-modality brain PET-CT image segmentation based on adaptive use of functional and anatomical information.

    PubMed

    Xia, Yong; Eberl, Stefan; Wen, Lingfeng; Fulham, Michael; Feng, David Dagan

    2012-01-01

    Dual medical imaging modalities, such as PET-CT, are now a routine component of clinical practice. Medical image segmentation methods, however, have generally only been applied to single modality images. In this paper, we propose the dual-modality image segmentation model to segment brain PET-CT images into gray matter, white matter and cerebrospinal fluid. This model converts PET-CT image segmentation into an optimization process controlled simultaneously by PET and CT voxel values and spatial constraints. It is innovative in the creation and application of the modality discriminatory power (MDP) coefficient as a weighting scheme to adaptively combine the functional (PET) and anatomical (CT) information on a voxel-by-voxel basis. Our approach relies upon allowing the modality with higher discriminatory power to play a more important role in the segmentation process. We compared the proposed approach to three other image segmentation strategies, including PET-only based segmentation, combination of the results of independent PET image segmentation and CT image segmentation, and simultaneous segmentation of joint PET and CT images without an adaptive weighting scheme. Our results in 21 clinical studies showed that our approach provides the most accurate and reliable segmentation for brain PET-CT images.

  17. Upsampling range camera depth maps using high-resolution vision camera and pixel-level confidence classification

    NASA Astrophysics Data System (ADS)

    Tian, Chao; Vaishampayan, Vinay; Zhang, Yifu

    2011-03-01

    We consider the problem of upsampling a low-resolution depth map generated by a range camera, by using information from one or more additional high-resolution vision cameras. The goal is to provide an accurate high resolution depth map from the viewpoint of one of the vision cameras. We propose an algorithm that first converts the low resolution depth map into a depth/disparity map through coordinate mappings into the coordinate frame of one vision camera, then classifies the pixels into regions according to whether the range camera depth map is trustworthy, and finally refine the depth values for the pixels in the untrustworthy regions. For the last refinement step, both a method based on graph cut optimization and that based on bilateral filtering are examined. Experimental results show that the proposed methods using classification are able to upsample the depth map by a factor of 10 x 10 with much improved depth details, with significantly better accuracy comparing to those without the classification. The improvements are visually perceptible on a 3D auto-stereoscopic display.

  18. Surveillance of a 2D plane area with 3D deployed cameras.

    PubMed

    Fu, Yi-Ge; Zhou, Jie; Deng, Lei

    2014-01-24

    As the use of camera networks has expanded, camera placement to satisfy some quality assurance parameters (such as a good coverage ratio, an acceptable resolution constraints, an acceptable cost as low as possible, etc.) has become an important problem. The discrete camera deployment problem is NP-hard and many heuristic methods have been proposed to solve it, most of which make very simple assumptions. In this paper, we propose a probability inspired binary Particle Swarm Optimization (PI-BPSO) algorithm to solve a homogeneous camera network placement problem. We model the problem under some more realistic assumptions: (1) deploy the cameras in the 3D space while the surveillance area is restricted to a 2D ground plane; (2) deploy the minimal number of cameras to get a maximum visual coverage under more constraints, such as field of view (FOV) of the cameras and the minimum resolution constraints. We can simultaneously optimize the number and the configuration of the cameras through the introduction of a regulation item in the cost function. The simulation results showed the effectiveness of the proposed PI-BPSO algorithm.

  19. Mini gamma cameras for intra-operative nuclear tomographic reconstruction.

    PubMed

    Matthies, Philipp; Gardiazabal, José; Okur, Aslı; Vogel, Jakob; Lasser, Tobias; Navab, Nassir

    2014-12-01

    Nuclear imaging modalities like PET or SPECT are in extensive use in medical diagnostics. In a move towards personalized therapy, we present a flexible nuclear tomographic imaging system to enable intra-operative SPECT-like 3D imaging. The system consists of a miniaturized gamma camera mounted on a robot arm for flexible positioning, while spatio-temporal localization is provided by an optical tracking system. To facilitate statistical tomographic reconstruction of the radiotracer distribution using a maximum likelihood approach, a precise model of the mini gamma camera is generated by measurements. The entire system is evaluated in a series of experiments using a hot spot phantom, with a focus on criteria relevant for the intra-operative workflow, namely the number of required imaging positions as well as the required imaging time. The results show that high quality reconstructed images of simple hot spot configurations with positional errors of less than one millimeter are possible within acquisition times as short as 15s.

  20. PET Metabolic Biomarkers for Cancer

    PubMed Central

    Croteau, Etienne; Renaud, Jennifer M.; Richard, Marie Anne; Ruddy, Terrence D.; Bénard, François; deKemp, Robert A.

    2016-01-01

    The body’s main fuel sources are fats, carbohydrates (glucose), proteins, and ketone bodies. It is well known that an important hallmark of cancer cells is the overconsumption of glucose. Positron emission tomography (PET) imaging using the glucose analog 18F-fluorodeoxyglucose (18F-FDG) has been a powerful cancer diagnostic tool for many decades. Apart from surgery, chemotherapy and radiotherapy represent the two main domains for cancer therapy, targeting tumor proliferation, cell division, and DNA replication—all processes that require a large amount of energy. Currently, in vivo clinical imaging of metabolism is performed almost exclusively using PET radiotracers that assess oxygen consumption and mechanisms of energy substrate consumption. This paper reviews the utility of PET imaging biomarkers for the detection of cancer proliferation, vascularization, metabolism, treatment response, and follow-up after radiation therapy, chemotherapy, and chemotherapy-related side effects. PMID:27679534

  1. Understanding advertising in pet nutrition.

    PubMed Central

    Brown, R G

    1994-01-01

    Advertising is part of the effort to attract attention of consumers to products, in this case, pet foods. It is generally benign in its effect, but it can be misleading, although rarely deliberately so. It uses a specialized vocabulary, which must be mastered if one is to understand what is intended. For all of the expense and effort, advertising figures directly in relatively few decisions to purchase. Its main intention is to call our attention to a particular pet food and to give that product an image. If the pet food does not perform in the consumer's hands, then all of the advertising on earth will not be persuasive. On the other hand, if a product performs well, the word-of-mouth will be positive and that mode of advertising is one of the most effective. PMID:8076285

  2. Promoting the exotic pet practice.

    PubMed

    Harris, Don J

    2005-09-01

    The marketing and promotion of an exotic pet veterinary practice allows the use of strategies that are not necessarily available in other veterinary disciplines. The advantage that an exotics practice enjoys is that it is able to capitalize not only on the unique nature of the species being attended but also on the specialized features of the hospital itself that make it specifically appropriate in caring for exotic pets. Before marketing, however, comes the responsibility that the practice live up to the claims made in promotional materials. A practice cannot ethically be presented as an "exotics" practice if it is nothing more than a dog and cat facility that is willing to attend to exotic pets. It is the competence of the veterinary staff and the appropriateness of the facility that determines the suitability of the practice for exotics management.

  3. Latest achievements in PET techniques

    NASA Astrophysics Data System (ADS)

    Del Guerra, Alberto; Belcari, Nicola; Motta, Alfonso; Di Domenico, Giovanni; Sabba, Nicola; Zavattini, Guido

    2003-11-01

    Positron emission tomography (PET) has moved from a distinguished research tool in physiology, cardiology and neurology to become a major tool for clinical investigation in oncology, in cardiac applications and in neurological disorders. Much of the PET accomplishments is due to the remarkable improvements in the last 10 years both in hardware and software aspects. Nowadays a similar effort is made by many research groups towards the construction of dedicated PET apparatus in new emerging fields such as molecular medicine, gene therapy, breast cancer imaging and combined modalities. This paper reports on some recent results we have obtained in small animal imaging and positron emission mammography, based on the use of advanced technology in the field of scintillators and photodetectors, such as Position-Sensitive Detectors coupled to crystal matrices, combined use of scintillating fibers and Hybrid-Photo-Diodes readout, and Hamamatsu flat panels. New ideas and future developments are discussed.

  4. 36 CFR 13.1234 - Pets.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 36 Parks, Forests, and Public Property 1 2013-07-01 2013-07-01 false Pets. 13.1234 Section 13.1234 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR NATIONAL PARK... § 13.1234 Pets. Possessing a pet in the BCDA is prohibited....

  5. 36 CFR 13.1234 - Pets.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 36 Parks, Forests, and Public Property 1 2014-07-01 2014-07-01 false Pets. 13.1234 Section 13.1234 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR NATIONAL PARK... § 13.1234 Pets. Possessing a pet in the BCDA is prohibited....

  6. 36 CFR 13.1234 - Pets.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 36 Parks, Forests, and Public Property 1 2012-07-01 2012-07-01 false Pets. 13.1234 Section 13.1234 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR NATIONAL PARK... § 13.1234 Pets. Possessing a pet in the BCDA is prohibited....

  7. 7 CFR 503.11 - Pets.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 6 2014-01-01 2014-01-01 false Pets. 503.11 Section 503.11 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL RESEARCH SERVICE, DEPARTMENT OF AGRICULTURE CONDUCT ON PLUM ISLAND ANIMAL DISEASE CENTER § 503.11 Pets. No pets or animals of any kind may be...

  8. 7 CFR 503.11 - Pets.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 6 2010-01-01 2010-01-01 false Pets. 503.11 Section 503.11 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL RESEARCH SERVICE, DEPARTMENT OF AGRICULTURE CONDUCT ON PLUM ISLAND ANIMAL DISEASE CENTER § 503.11 Pets. No pets or animals of any kind may be...

  9. 7 CFR 503.11 - Pets.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 6 2011-01-01 2011-01-01 false Pets. 503.11 Section 503.11 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL RESEARCH SERVICE, DEPARTMENT OF AGRICULTURE CONDUCT ON PLUM ISLAND ANIMAL DISEASE CENTER § 503.11 Pets. No pets or animals of any kind may be...

  10. 36 CFR 13.1234 - Pets.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Pets. 13.1234 Section 13.1234 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR NATIONAL PARK... § 13.1234 Pets. Possessing a pet in the BCDA is prohibited....

  11. 7 CFR 500.10 - Pets.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 6 2010-01-01 2010-01-01 false Pets. 500.10 Section 500.10 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL RESEARCH SERVICE, DEPARTMENT OF AGRICULTURE NATIONAL ARBORETUM Conduct on U.S. National Arboreturm Property § 500.10 Pets. Pets brought upon...

  12. Saying Goodbye: Pet Loss and Its Implications

    ERIC Educational Resources Information Center

    Duffey, Thelma

    2005-01-01

    Pets can be loyal, loving, and entertaining members of a family. Their deaths are generally experienced as painful losses by the people who love them, even though the grief experience is often culturally disenfranchised. In this manuscript, we discuss the role that pets can play in a person's life; the effects that pet loss can have on the people…

  13. 7 CFR 500.10 - Pets.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 6 2011-01-01 2011-01-01 false Pets. 500.10 Section 500.10 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL RESEARCH SERVICE, DEPARTMENT OF AGRICULTURE NATIONAL ARBORETUM Conduct on U.S. National Arboreturm Property § 500.10 Pets. Pets brought upon...

  14. 36 CFR 13.1234 - Pets.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 1 2011-07-01 2011-07-01 false Pets. 13.1234 Section 13.1234 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR NATIONAL PARK... § 13.1234 Pets. Possessing a pet in the BCDA is prohibited....

  15. 7 CFR 503.11 - Pets.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 6 2012-01-01 2012-01-01 false Pets. 503.11 Section 503.11 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL RESEARCH SERVICE, DEPARTMENT OF AGRICULTURE CONDUCT ON PLUM ISLAND ANIMAL DISEASE CENTER § 503.11 Pets. No pets or animals of any kind may be...

  16. 7 CFR 503.11 - Pets.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 6 2013-01-01 2013-01-01 false Pets. 503.11 Section 503.11 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL RESEARCH SERVICE, DEPARTMENT OF AGRICULTURE CONDUCT ON PLUM ISLAND ANIMAL DISEASE CENTER § 503.11 Pets. No pets or animals of any kind may be...

  17. Pets in the family: practical approaches.

    PubMed

    Hodgson, Kate; Darling, Marcia

    2011-01-01

    Adapting family life cycle theory to include pets provides veterinarians with a framework for understanding and reinforcing the human-animal bond. The family genogram with pets is a practice tool that identifies all people and pets in the family, enhancing the practice of One Health at the community level.

  18. 7 CFR 502.11 - Pets.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... vaccinations. Pets that are the property of employees residing on BARC must be up to date on their vaccinations... 7 Agriculture 6 2014-01-01 2014-01-01 false Pets. 502.11 Section 502.11 Agriculture Regulations of... CONDUCT ON BELTSVILLE AGRICULTURE RESEARCH CENTER PROPERTY, BELTSVILLE, MARYLAND § 502.11 Pets....

  19. 7 CFR 500.10 - Pets.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 6 2014-01-01 2014-01-01 false Pets. 500.10 Section 500.10 Agriculture Regulations of... NATIONAL ARBORETUM Conduct on U.S. National Arboreturm Property § 500.10 Pets. Pets brought upon USNA property must have proper vaccinations and, except assistance trained animals, must be kept on leash at...

  20. 7 CFR 500.10 - Pets.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 6 2013-01-01 2013-01-01 false Pets. 500.10 Section 500.10 Agriculture Regulations of... NATIONAL ARBORETUM Conduct on U.S. National Arboreturm Property § 500.10 Pets. Pets brought upon USNA property must have proper vaccinations and, except assistance trained animals, must be kept on leash at...

  1. 7 CFR 502.11 - Pets.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... vaccinations. Pets that are the property of employees residing on BARC must be up to date on their vaccinations... 7 Agriculture 6 2012-01-01 2012-01-01 false Pets. 502.11 Section 502.11 Agriculture Regulations of... CONDUCT ON BELTSVILLE AGRICULTURE RESEARCH CENTER PROPERTY, BELTSVILLE, MARYLAND § 502.11 Pets....

  2. 7 CFR 502.11 - Pets.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... vaccinations. Pets that are the property of employees residing on BARC must be up to date on their vaccinations... 7 Agriculture 6 2013-01-01 2013-01-01 false Pets. 502.11 Section 502.11 Agriculture Regulations of... CONDUCT ON BELTSVILLE AGRICULTURE RESEARCH CENTER PROPERTY, BELTSVILLE, MARYLAND § 502.11 Pets....

  3. 7 CFR 500.10 - Pets.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 6 2012-01-01 2012-01-01 false Pets. 500.10 Section 500.10 Agriculture Regulations of... NATIONAL ARBORETUM Conduct on U.S. National Arboreturm Property § 500.10 Pets. Pets brought upon USNA property must have proper vaccinations and, except assistance trained animals, must be kept on leash at...

  4. A Guide to Managing Your Classroom Pets.

    ERIC Educational Resources Information Center

    Caras, Robert

    1980-01-01

    The author suggests eight ideal classroom pets: hamsters; turtles; snakes; spiders; frogs and toads; fish; and birds. For each he gives suggestions on selecting the pet and housing and feeding it in the classroom. Desert terrariums and home pet care training are also discussed. (SJL)

  5. Selecting a digital camera for telemedicine.

    PubMed

    Patricoski, Chris; Ferguson, A Stewart

    2009-06-01

    The digital camera is an essential component of store-and-forward telemedicine (electronic consultation). There are numerous makes and models of digital cameras on the market, and selecting a suitable consumer-grade camera can be complicated. Evaluation of digital cameras includes investigating the features and analyzing image quality. Important features include the camera settings, ease of use, macro capabilities, method of image transfer, and power recharging. Consideration needs to be given to image quality, especially as it relates to color (skin tones) and detail. It is important to know the level of the photographer and the intended application. The goal is to match the characteristics of the camera with the telemedicine program requirements. In the end, selecting a digital camera is a combination of qualitative (subjective) and quantitative (objective) analysis. For the telemedicine program in Alaska in 2008, the camera evaluation and decision process resulted in a specific selection based on the criteria developed for our environment.

  6. The wide field/planetary camera

    NASA Technical Reports Server (NTRS)

    Westphal, J. A.; Baum, W. A.; Code, A. D.; Currie, D. G.; Danielson, G. E.; Gunn, J. E.; Kelsall, T. F.; Kristian, J. A.; Lynds, C. R.; Seidelmann, P. K.

    1982-01-01

    A wide site of potential astronomical and solar system scientific studies using the wide field planetary camera on space telescope are described. The expected performance of the camera as it approaches final assembly and testing is also detailed.

  7. Depth perception with a rotationally symmetric coded camera

    NASA Astrophysics Data System (ADS)

    Chang, Chuan-Chung; Chen, Yung-Lin; Chang, Chir-Weei; Lee, Cheng-Chung

    2009-08-01

    A novel design of a phase coded depth-sensing camera is presented. A rotational symmetric phase mask is designed to discriminate the point spread functions (PSF) from different scene distances. The depth information can then be computationally obtained from a single captured photograph through a phase coded lens. The PSF must be carefully optimized at off-axis angles in order to create a restored image which is sharp over the required field of view. In this paper, a phase coded depth camera with a focal length 10.82mm, sensor size 2mm and F-number 5 is designed. Simulation data is exchanged between Matlab and Zemax for co-optimization of optical coding and digital decoding process. The simulation result shows that coarse depth information is investigated for object distance from 513 mm to 1000 mm.

  8. Incremental Real-Time Bundle Adjustment for Multi-Camera Systems with Points at Infinity

    NASA Astrophysics Data System (ADS)

    Schneider, J.; Läbe, T.; Förstner, W.

    2013-08-01

    This paper presents a concept and first experiments on a keyframe-based incremental bundle adjustment for real-time structure and motion estimation in an unknown scene. In order to avoid periodic batch steps, we use the software iSAM2 for sparse nonlinear incremental optimization, which is highly efficient through incremental variable reordering and fluid relinearization. We adapted the software to allow for (1) multi-view cameras by taking the rigid transformation between the cameras into account, (2) omnidirectional cameras as it can handle arbitrary bundles of rays and (3) scene points at infinity, which improve the estimation of the camera orientation as points at the horizon can be observed over long periods of time. The real-time bundle adjustment refers to sets of keyframes, consisting of frames, one per camera, taken in a synchronized way, that are initiated if a minimal geometric distance to the last keyframe set is exceeded. It uses interest points in the keyframes as observations, which are tracked in the synchronized video streams of the individual cameras and matched across the cameras, if possible. First experiments show the potential of the incremental bundle adjustment w.r.t. time requirements. Our experiments are based on a multi-camera system with four fisheye cameras, which are mounted on a UAV as two stereo pairs, one looking ahead and one looking backwards, providing a large field of view.

  9. Quantitative analysis of PET studies.

    PubMed

    Weber, Wolfgang A

    2010-09-01

    Quantitative analysis can be included relatively easily in clinical PET-imaging protocols, but in order to obtain meaningful quantitative results one needs to follow a standardized protocol for image acquisition and data analysis. Important factors to consider are the calibration of the PET scanner, the radiotracer uptake time and the approach for definition of regions of interests. Using such standardized acquisition protocols quantitative parameters of tumor metabolism or receptor status can be derived from tracer kinetic analysis and simplified approaches such as calculation of standardized uptake values (SUVs).

  10. [Pets for the mentally ill].

    PubMed

    Jonas, C; Feline, A

    1981-07-01

    After studying the historical importance of the domestic animal through the ages and the role of the "pet" animal in the contemporary world, the authors present an analysis of the literature dealing with the function of the animal in child development and the use of animals as therapeutic "tools". The author's then consider, based on a series of observations, the relationship certain mentally ill patients may establish with one or several pet animals and the significance this object relation may have for the patient : animals become invested as counter depressive or delusional objects, auxiliary means for identification and projection, symbiotic relationship, as well as encouraging feeling of security and responsibility.

  11. PET/CT and Bremsstrahlung Imaging After 90Y DOTANOC Therapy for Rectal Net With Liver Metastases.

    PubMed

    Abdülrezzak, Ümmühan; Kula, Mustafa; Tutuş, Ahmet; Buyukkaya, Fikret; Karaca, Halit

    2015-10-01

    Peptide receptor radionuclide therapy with Lu or Y is promising with successful results in somatostatin receptor-positive tumors. In all radiation therapies, knowledge of the radiation dose received by the target, and other organs in the body is essential to evaluate the risks and benefits of any procedure. We report a case of liver metastases from a rectal neuroendocrine tumor, which was treated with Y DOTANOC. Posttreatment whole-body planar images were acquired through Bremsstrahlung radiations of Y on a γ-camera, and thoracolumbar PET/CT images were acquired on PET.

  12. Flash photography by digital still camera

    NASA Astrophysics Data System (ADS)

    Yamamoto, Yoshitaka

    2001-04-01

    Recently, the number of commercially produced digital still cameras has increases rapidly. However, detailed performance of digital still camera had not been evaluated. One of the purposes of this paper is to devise the method of evaluating the performance of a new camera. Another purpose is to show possibility of taking a picture of a scientific high quality photograph with a camera on the market, and taking a picture of a high-speed phenomenon.

  13. Electronographic cameras for space astronomy.

    NASA Technical Reports Server (NTRS)

    Carruthers, G. R.; Opal, C. B.

    1972-01-01

    Magnetically-focused electronographic cameras have been under development at the Naval Research Laboratory for use in far-ultraviolet imagery and spectrography, primarily in astronomical and optical-geophysical observations from sounding rockets and space vehicles. Most of this work has been with cameras incorporating internal optics of the Schmidt or wide-field all-reflecting types. More recently, we have begun development of electronographic spectrographs incorporating an internal concave grating, operating at normal or grazing incidence. We also are developing electronographic image tubes of the conventional end-window-photo-cathode type, for far-ultraviolet imagery at the focus of a large space telescope, with image formats up to 120 mm in diameter.

  14. GRAVITY acquisition camera: characterization results

    NASA Astrophysics Data System (ADS)

    Anugu, Narsireddy; Garcia, Paulo; Amorim, Antonio; Wiezorrek, Erich; Wieprecht, Ekkehard; Eisenhauer, Frank; Ott, Thomas; Pfuhl, Oliver; Gordo, Paulo; Perrin, Guy; Brandner, Wolfgang; Straubmeier, Christian; Perraut, Karine

    2016-08-01

    GRAVITY acquisition camera implements four optical functions to track multiple beams of Very Large Telescope Interferometer (VLTI): a) pupil tracker: a 2×2 lenslet images four pupil reference lasers mounted on the spiders of telescope secondary mirror; b) field tracker: images science object; c) pupil imager: reimages telescope pupil; d) aberration tracker: images a Shack-Hartmann. The estimation of beam stabilization parameters from the acquisition camera detector image is carried out, for every 0.7 s, with a dedicated data reduction software. The measured parameters are used in: a) alignment of GRAVITY with the VLTI; b) active pupil and field stabilization; c) defocus correction and engineering purposes. The instrument is now successfully operational on-sky in closed loop. The relevant data reduction and on-sky characterization results are reported.

  15. Combustion pinhole-camera system

    DOEpatents

    Witte, A.B.

    1982-05-19

    A pinhole camera system is described utilizing a sealed optical-purge assembly which provides optical access into a coal combustor or other energy conversion reactors. The camera system basically consists of a focused-purge pinhole optical port assembly, a conventional TV vidicon receiver, an external, variable density light filter which is coupled electronically to the vidicon automatic gain control (agc). The key component of this system is the focused-purge pinhole optical port assembly which utilizes a purging inert gas to keep debris from entering the port and a lens arrangement which transfers the pinhole to the outside of the port assembly. One additional feature of the port assembly is that it is not flush with the interior of the combustor.

  16. A 10-microm infrared camera.

    PubMed

    Arens, J F; Jernigan, J G; Peck, M C; Dobson, C A; Kilk, E; Lacy, J; Gaalema, S

    1987-09-15

    An IR camera has been built at the University of California at Berkeley for astronomical observations. The camera has been used primarily for high angular resolution imaging at mid-IR wavelengths. It has been tested at the University of Arizona 61- and 90-in. telescopes near Tucson and the NASA Infrared Telescope Facility on Mauna Kea, HI. In the observations the system has been used as an imager with interference coated and Fabry-Perot filters. These measurements have demonstrated a sensitivity consistent with photon shot noise, showing that the system is limited by the radiation from the telescope and atmosphere. Measurements of read noise, crosstalk, and hysteresis have been made in our laboratory.

  17. Preliminary studies of PQS PET detector module for dose verification of carbon beam therapy

    NASA Astrophysics Data System (ADS)

    Kim, H.-I.; An, S. Jung; Lee, C. Y.; Jo, W. J.; Min, E.; Lee, K.; Kim, Y.; Joung, J.; Chung, Y. H.

    2014-05-01

    PET imaging can be used to verify dose distributions of therapeutic particle beams such as carbon ion beams. The purpose of this study was to develop a PET detector module which was designed for an in-beam PET scanner geometry integrated into a carbon beam therapy system, and to evaluate its feasibility as a monitoring system of patient dose distribution. A C-shaped PET geometry was proposed to avoid blockage of the carbon beam by the detector modules. The proposed PET system consisted of 14 detector modules forming a bore with 30.2 cm inner diameter for brain imaging. Each detector module is composed of a 9 × 9 array of 4.0 mm × 4.0 mm × 20.0 mm LYSO crystal module optically coupled with four 29 mm diameter PMTs using Photomultiplier-quadrant-sharing (PQS) technique. Because the crystal pixel was identified based upon the distribution of scintillation lights of four PMTs, the design of the reflector between crystal elements should be well optimized. The optical design of reflectors was optimized using DETECT2000, a Monte Carlo code for light photon transport. A laser-cut reflector set was developed using the Enhanced Specular Reflector (ESR, 3M Co.) mirror-film with a high reflectance of 98% and a thickness of 0.064 mm. All 81 crystal elements of detector module were identified. Our result demonstrates that the C-shaped PET system is under development and we present the first reconstructed image.

  18. The OCA CCD Camera Controller

    DTIC Science & Technology

    1996-01-01

    blank) -2. REPORT DATE 3 . REPORT TYPE AND DATES COVERED •. . ..December 1996 , 1996 Final Report - Ř. TITLE AND SUBTITLE 5. FUNDING NUMBERS The OCA...Physical. implementation of a multi CCD camera Appendix 1: Contrbller schematics Appendix 2: Data sheets of the the major components Appendix 3 ...the final-report for EOARD cbntract ##SPC-93-4007. R? 3 %o-/ Ob. 7(, It contains the following sections: - Requirements analysis - Description of the

  19. The PS1 Gigapixel Camera

    NASA Astrophysics Data System (ADS)

    Tonry, John L.; Isani, S.; Onaka, P.

    2007-12-01

    The world's largest and most advanced digital camera has been installed on the Pan-STARRS-1 (PS1) telescope on Haleakala, Maui. Built at the University of Hawaii at Manoa's Institute for Astronomy (IfA) in Honolulu, the gigapixel camera will capture images that will be used to scan the skies for killer asteroids, and to create the most comprehensive catalog of stars and galaxies ever produced. The CCD sensors at the heart of the camera were developed in collaboration with Lincoln Laboratory of the Massachusetts Institute of Technology. The image area, which is about 40 cm across, contains 60 identical silicon chips, each of which contains 64 independent imaging circuits. Each of these imaging circuits contains approximately 600 x 600 pixels, for a total of about 1.4 gigapixels in the focal plane. The CCDs themselves employ the innovative technology called "orthogonal transfer." Splitting the image area into about 4,000 separate regions in this way has three advantages: data can be recorded more quickly, saturation of the image by a very bright star is confined to a small region, and any defects in the chips only affect only a small part of the image area. The CCD camera is controlled by an ultrafast 480-channel control system developed at the IfA. The individual CCD cells are grouped in 8 x 8 arrays on a single silicon chip called an orthogonal transfer array (OTA), which measures about 5 cm square. There are a total of 60 OTAs in the focal plane of each telescope.

  20. SPEIR: A Ge Compton Camera

    SciTech Connect

    Mihailescu, L; Vetter, K M; Burks, M T; Hull, E L; Craig, W W

    2004-02-11

    The SPEctroscopic Imager for {gamma}-Rays (SPEIR) is a new concept of a compact {gamma}-ray imaging system of high efficiency and spectroscopic resolution with a 4-{pi} field-of-view. The system behind this concept employs double-sided segmented planar Ge detectors accompanied by the use of list-mode photon reconstruction methods to create a sensitive, compact Compton scatter camera.