WorldWideScience

Sample records for access mri system

  1. Posture-Dependent Human 3He Lung Imaging in an Open Access MRI System: Initial Results

    Tsai, L L; Li, C -H; Rosen, M S; Patz, S; Walsworth, R L

    2007-01-01

    The human lung and its functions are extremely sensitive to orientation and posture, and debate continues as to the role of gravity and the surrounding anatomy in determining lung function and heterogeneity of perfusion and ventilation. However, study of these effects is difficult. The conventional high-field magnets used for most hyperpolarized 3He MRI of the human lung, and most other common radiological imaging modalities including PET and CT, restrict subjects to lying horizontally, minimizing most gravitational effects. In this paper, we briefly review the motivation for posture-dependent studies of human lung function, and present initial imaging results of human lungs in the supine and vertical body orientations using inhaled hyperpolarized 3He gas and an open-access MRI instrument. The open geometry of this MRI system features a "walk-in" capability that permits subjects to be imaged in vertical and horizontal positions, and potentially allows for complete rotation of the orientation of the imaging su...

  2. Open-Access, Low-Magnetic-Field MRI System for Lung Research

    Mair, Ross W.; Rosen, Matthew S.; Tsai, Leo L.; Walsworth, Ronald L.; Hrovat, Mirko I.; Patz, Samuel; Ruset, Iullian C.; Hersman, F. William

    2009-01-01

    An open-access magnetic resonance imaging (MRI) system is being developed for use in research on orientational/gravitational effects on lung physiology and function. The open-access geometry enables study of human subjects in diverse orientations. This system operates at a magnetic flux density, considerably smaller than the flux densities of typical other MRI systems, that can be generated by resistive electromagnet coils (instead of the more-expensive superconducting coils of the other systems). The human subject inhales air containing He-3 or Xe-129 atoms, the nuclear spins of which have been polarized by use of a laser beam to obtain a magnetic resonance that enables high-resolution gas space imaging at the low applied magnetic field. The system includes a bi-planar, constant-current, four-coil electromagnet assembly and associated electronic circuitry to apply a static magnetic field of 6.5 mT throughout the lung volume; planar coils and associated circuitry to apply a pulsed magnetic-field-gradient for each spatial dimension; a single, detachable radio-frequency coil and associated circuitry for inducing and detecting MRI signals; a table for supporting a horizontal subject; and electromagnetic shielding surrounding the electromagnet coils.

  3. Orientation-Dependent 3He Lung Imaging in an Open Access, Very-Low-Field Human MRI System

    Mair, R W; Patz, S; Rosen, M S; Ruset, I C; Topulos, G P; Tsai, L L; Butler, J P; Hersman, F W; Walsworth, R L

    2004-01-01

    Orientation-dependent imaging of human lungs is demonstrated using inhaled laser-polarized 3He gas and an open-access very-low-magnetic field (< 5 mT) MRI instrument. This prototype device employs a simple, low-cost electromagnet, with an open geometry that allows variation of the orientation of the imaging subject in a two-dimensional plane. Two-dimensional 3He images were acquired with 2 mm in-plane resolution from a subject in two orientations: lying supine, and sitting in a vertical position with one arm raised. The images show clear differences in lung shape and inhaled 3He gas distribution, consistent with the expected orientation dependence of pulmonary physiology.

  4. OGIS Access System

    National Archives and Records Administration — The OGIS Access System (OAS) provides case management, stakeholder collaboration, and public communications activities including a web presence via a web portal.

  5. Advanced access control system

    A prototype voice verification system has been installed which provides the required positive identification at the main site access control point. This system compares an individual's file voice print with a sample voice print obtained from the individual when an attempt is made to enter the site. The voice system transmits the individual's identify to a central processor. The system installed at the Barnwell Nuclear Fuel Plant is described

  6. Advanced access control system

    A prototype voice verification system has been installed which provides the required positive identification at the main site access control point. This system compares an individual's file voice print with a sample voice print obtained from the individual when an attempt is made to enter the site. The voice system transmits the individual's identity to a central processor. The central processor associates that individual's authorization file with a card-key obtained at the access point. The system generates a record of personnel movement, provides a personnel inventory on a real-time basis, and it can retrieve a record of all prior events. The system installed at the Barnwell Nuclear Fuel Plant is described

  7. MRI of central nervous system anomalies

    MRI was very useful in the evaluation of congenital anomalies of central nervous system as well as other nervous system disease with three-dimensional spatial resolution. We had experienced MRI of central nervous system anomalies, demonstrated characterisitic findings in each anomaly. MRI is useful to observe the coronal, horizontal and sagittal images of the brain and spinal cord in order to discuss the etiological mechanisms of spinal dysraphysm and its associated anomalies. In case of spina bifida cystica MRI was available to decide operative indication for radical operation and tetherd cord developed from postoperative scar or accompanied intraspinal lesions. (author)

  8. MRI of central nervous system anomalies

    Izawa, M.; Oikawa, A.; Matoba, A.

    1987-05-01

    MRI was very useful in the evaluation of congenital anomalies of central nervous system as well as other nervous system disease with three-dimensional spatial resolution. We had experienced MRI of central nervous system anomalies, demonstrated characterisitic findings in each anomaly. MRI is useful to observe the coronal, horizontal and sagittal images of the brain and spinal cord in order to discuss the etiological mechanisms of spinal dysraphysm and its associated anomalies. In case of spina bifida cystica MRI was available to decide operative indication for radical operation and tetherd cord developed from postoperative scar or accompanied intraspinal lesions.

  9. Nuclear information access system

    The energy supply in the countries, which have abundant energy resources, may not be affected by accepting the assertion of anti-nuclear and environment groups. Anti-nuclear movements in the countries which have little energy resources may cause serious problem in securing energy supply. Especially, it is distinct in Korea because she heavily depends on nuclear energy in electricity supply(nuclear share in total electricity supply is about 40%).The cause of social trouble surrounding nuclear energy is being involved with various circumstances. However, it is very important that we are not aware of the importance of information access and prepared for such a situation from the early stage of nuclear energy's development. In those matter, this paper analyzes the contents of nuclear information access system in France and Japan which have dynamic nuclear development program and presents the direction of the nuclear access regime through comparing Korean status and referring to progresses of the regime

  10. Central nervous system tuberculosis: MRI

    The MRI findings of 18 proven cases of central nervous system (CNS) tuberculosis were reviewed; 10 patients were seropositive for HIV. All had medical, laboratory, or surgical proof of CNS tuberculosis. Eleven patients had meningitis, of whom two also had arachnoiditis. Five patients had focal intra-axial tuberculomas: four brain masses and one an intramedullary spinal lesion. Two patients had focal extra-axial tuberculomas: one in the pontine cistern, and one in the spine. In all 11 patients with meningitis MRI showed diffuse, thick, meningeal enhancement. All intraparenchymal tuberculomas showed low signal intensity on T2-weighted images and ring or nodular enhancement. The extra-axial tuberculomas had areas isointense or hypointense relative to normal brain and spinal cord on T2-weighted images. Although tuberculous meningitis cannot be differentiated from other meningitides on the basis of MR findings, intraparenchymal tuberculomas show characteristic T2 shortening, not found in most other space-occupying lesions. In the appropriate clinical setting, tuberculoma should be considered. (orig.)

  11. Timing of MRI in pregnancy, repeat exams, access, and physician qualifications.

    Levine, Deborah

    2013-10-01

    This review addresses specific questions regarding performance and utility of fetal MR. The specific issues addressed are (1) physician qualifications; (2) MR safety; (3) access to fetal MR; (4) timing of MRI in pregnancy; (5) repeat exams; and (6) when MRI is most effective for prenatal diagnosis. Fetal MRI is a problem-solving tool used for specific indications that are driven by ultrasound or at times by family history. Fetal MR should always be performed with knowledge of the sonographic findings from prior targeted scan. The best evidence for utility of MR is in assessment of CNS anomalies and assessment of the fetus with airway obstruction requiring decisions regarding mode of therapy. The type of information provided by MR can profoundly impact patient counseling and management. We recommend a team approach including specialists in obstetric imaging, fetal MRI, and postnatal care in interpreting MR so that the best information can be given to the pregnant patient. PMID:24176157

  12. Access control system for ISABELLE

    An access system based on the one now in operation at the CERN ISR is recommended. Access doors would presumably be located at the entrances to the utility tunnels connecting the support buildings with the ring. Persons requesting access would insert an identity card into a scanner to activate the system. The request would be autologged, the keybank adjacent to the door would be unlocked and ISABELLE operations would be notified. The operator would then select the door, activating a TV-audio link. The person requesting entry would draw a key from the bank, show it and his film badge to the operator who would enable the door release

  13. Positioning device for MRI-guided high intensity focused ultrasound system

    A prototype magnetic resonance imaging (MRI)- compatible positioning device was used to move an MRI-guided high intensity focused ultrasound (HIFU) transducer. The positioning device has three user-controlled degrees of freedom that allow access to various targeted lesions. The positioning device was designed and fabricated using construction materials selected for compatibility with high magnetic fields and fast switching magnetic field gradients encountered inside MRI scanners. The positioning device incorporates only MRI compatible materials such as piezoelectric motors, plastic sheets, brass screws, plastic pulleys and timing belts. The HIFU/MRI system includes the multiple subsystems (a) HIFU system, (b) MR imaging, (c) Positioning device (robot) and associate drivers, (d) temperature measurement, (e) cavitation detection, (f) MRI compatible camera, and (g) Soft ware. The MRI compatibility of the system was successfully demonstrated in a clinical high-field MRI scanner. The ability of the robot to accurately move the transducer thus creating discrete and overlapping lesions in biological tissue was tested successfully. A simple, cost effective, portable positioning device has been developed which can be used in virtually any clinical MRI scanner since it can be sited on the scanner's table. The propagation of HIFU can use either a lateral or superior-inferior approach. Discrete and large lesions were created successfully with reproducible results. (orig.)

  14. Positioning device for MRI-guided high intensity focused ultrasound system

    Damianou, Christakis [Frederick Institute of Technology (FIT), Limassol (Cyprus); MEDSONIC, LTD, Limassol (Cyprus); Ioannides, Kleanthis [Polikliniki Igia, Limassol (Cyprus); Milonas, Nicos [Frederick Institute of Technology (FIT), Limassol (Cyprus)

    2008-04-15

    A prototype magnetic resonance imaging (MRI)- compatible positioning device was used to move an MRI-guided high intensity focused ultrasound (HIFU) transducer. The positioning device has three user-controlled degrees of freedom that allow access to various targeted lesions. The positioning device was designed and fabricated using construction materials selected for compatibility with high magnetic fields and fast switching magnetic field gradients encountered inside MRI scanners. The positioning device incorporates only MRI compatible materials such as piezoelectric motors, plastic sheets, brass screws, plastic pulleys and timing belts. The HIFU/MRI system includes the multiple subsystems (a) HIFU system, (b) MR imaging, (c) Positioning device (robot) and associate drivers, (d) temperature measurement, (e) cavitation detection, (f) MRI compatible camera, and (g) Soft ware. The MRI compatibility of the system was successfully demonstrated in a clinical high-field MRI scanner. The ability of the robot to accurately move the transducer thus creating discrete and overlapping lesions in biological tissue was tested successfully. A simple, cost effective, portable positioning device has been developed which can be used in virtually any clinical MRI scanner since it can be sited on the scanner's table. The propagation of HIFU can use either a lateral or superior-inferior approach. Discrete and large lesions were created successfully with reproducible results. (orig.)

  15. Scalable multichannel MRI data acquisition system.

    Bodurka, Jerzy; Ledden, Patrick J; van Gelderen, Peter; Chu, Renxin; de Zwart, Jacco A; Morris, Doug; Duyn, Jeff H

    2004-01-01

    A scalable multichannel digital MRI receiver system was designed to achieve high bandwidth echo-planar imaging (EPI) acquisitions for applications such as BOLD-fMRI. The modular system design allows for easy extension to an arbitrary number of channels. A 16-channel receiver was developed and integrated with a General Electric (GE) Signa 3T VH/3 clinical scanner. Receiver performance was evaluated on phantoms and human volunteers using a custom-built 16-element receive-only brain surface coil array. At an output bandwidth of 1 MHz, a 100% acquisition duty cycle was achieved. Overall system noise figure and dynamic range were better than 0.85 dB and 84 dB, respectively. During repetitive EPI scanning on phantoms, the relative temporal standard deviation of the image intensity time-course was below 0.2%. As compared to the product birdcage head coil, 16-channel reception with the custom array yielded a nearly 6-fold SNR gain in the cerebral cortex and a 1.8-fold SNR gain in the center of the brain. The excellent system stability combined with the increased sensitivity and SENSE capabilities of 16-channel coils are expected to significantly benefit and enhance fMRI applications. PMID:14705057

  16. Computer access security code system

    Collins, Earl R., Jr. (Inventor)

    1990-01-01

    A security code system for controlling access to computer and computer-controlled entry situations comprises a plurality of subsets of alpha-numeric characters disposed in random order in matrices of at least two dimensions forming theoretical rectangles, cubes, etc., such that when access is desired, at least one pair of previously unused character subsets not found in the same row or column of the matrix is chosen at random and transmitted by the computer. The proper response to gain access is transmittal of subsets which complete the rectangle, and/or a parallelepiped whose opposite corners were defined by first groups of code. Once used, subsets are not used again to absolutely defeat unauthorized access by eavesdropping, and the like.

  17. Automated Computer Access Request System

    Snook, Bryan E.

    2010-01-01

    The Automated Computer Access Request (AutoCAR) system is a Web-based account provisioning application that replaces the time-consuming paper-based computer-access request process at Johnson Space Center (JSC). Auto- CAR combines rules-based and role-based functionality in one application to provide a centralized system that is easily and widely accessible. The system features a work-flow engine that facilitates request routing, a user registration directory containing contact information and user metadata, an access request submission and tracking process, and a system administrator account management component. This provides full, end-to-end disposition approval chain accountability from the moment a request is submitted. By blending both rules-based and rolebased functionality, AutoCAR has the flexibility to route requests based on a user s nationality, JSC affiliation status, and other export-control requirements, while ensuring a user s request is addressed by either a primary or backup approver. All user accounts that are tracked in AutoCAR are recorded and mapped to the native operating system schema on the target platform where user accounts reside. This allows for future extensibility for supporting creation, deletion, and account management directly on the target platforms by way of AutoCAR. The system s directory-based lookup and day-today change analysis of directory information determines personnel moves, deletions, and additions, and automatically notifies a user via e-mail to revalidate his/her account access as a result of such changes. AutoCAR is a Microsoft classic active server page (ASP) application hosted on a Microsoft Internet Information Server (IIS).

  18. An MRI system for imaging neonates in the NICU: initial feasibility study

    Transporting premature infants from a neonatal intensive care unit (NICU) to a radiology department for MRI has medical risks and logistical challenges. To develop a small 1.5-T MRI system for neonatal imaging that can be easily installed in the NICU and to evaluate its performance using a sheep model of human prematurity. A 1.5-T MRI system designed for orthopedic use was adapted for neonatal imaging. The system was used for MRI examinations of the brain, chest and abdomen in 12 premature lambs during the first hours of life. Spin-echo, fast spin-echo and gradient-echo MR images were evaluated by two pediatric radiologists. All animals remained physiologically stable throughout the imaging sessions. Animals were imaged at two or three time points. Seven brain MRI examinations were performed in seven different animals, 23 chest examinations in 12 animals and 19 abdominal examinations in 11 animals. At each anatomical location, high-quality images demonstrating good spatial resolution, signal-to-noise ratio and tissue contrast were routinely obtained within 30 min using standard clinical protocols. Our preliminary experience demonstrates the feasibility and potential of the neonatal MRI system to provide state-of-the-art MRI capabilities within the NICU. Advantages include overall reduced cost and site demands, lower acoustic noise, improved ease of access and reduced medical risk to the neonate. (orig.)

  19. An MRI system for imaging neonates in the NICU: initial feasibility study

    Tkach, Jean A.; Loew, Wolfgang; Pratt, Ron G.; Daniels, Barret R.; Giaquinto, Randy O.; Winter, Patrick M.; Li, Yu; Dumoulin, Charles L. [Cincinnati Children' s Hospital Medical Center, Imaging Research Center, Department of Radiology, Cincinnati, OH (United States); Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States); Hillman, Noah H.; Jobe, Alan H.; Kallapur, Suhas G.; Merhar, Stephanie L.; Ikegami, Machiko; Whitsett, Jeffrey A. [Perinatal Institute, Cincinnati Children' s Hospital Medical Center, Division of Neonatology and Pulmonary Biology, Cincinnati, OH (United States); Kline-Fath, Beth M. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States)

    2012-11-15

    Transporting premature infants from a neonatal intensive care unit (NICU) to a radiology department for MRI has medical risks and logistical challenges. To develop a small 1.5-T MRI system for neonatal imaging that can be easily installed in the NICU and to evaluate its performance using a sheep model of human prematurity. A 1.5-T MRI system designed for orthopedic use was adapted for neonatal imaging. The system was used for MRI examinations of the brain, chest and abdomen in 12 premature lambs during the first hours of life. Spin-echo, fast spin-echo and gradient-echo MR images were evaluated by two pediatric radiologists. All animals remained physiologically stable throughout the imaging sessions. Animals were imaged at two or three time points. Seven brain MRI examinations were performed in seven different animals, 23 chest examinations in 12 animals and 19 abdominal examinations in 11 animals. At each anatomical location, high-quality images demonstrating good spatial resolution, signal-to-noise ratio and tissue contrast were routinely obtained within 30 min using standard clinical protocols. Our preliminary experience demonstrates the feasibility and potential of the neonatal MRI system to provide state-of-the-art MRI capabilities within the NICU. Advantages include overall reduced cost and site demands, lower acoustic noise, improved ease of access and reduced medical risk to the neonate. (orig.)

  20. Fast Access Data Acquisition System

    Dr. Vladimir Katsman

    1998-03-17

    Our goal in this program is to develop Fast Access Data Acquisition System (FADAS) by combining the flexibility of Multilink's GaAs and InP electronics and electro-optics with an extremely high data rate for the efficient handling and transfer of collider experimental data. This novel solution is based on Multilink's and Los Alamos National Laboratory's (LANL) unique components and technologies for extremely fast data transfer, storage, and processing.

  1. Radio access selection in multi-radio access systems

    Jorgušeski, L.; Litjens, R.; Zhiyi, C.; Nikookar, H.

    2007-01-01

    Future wireless access systems will be characterized by their heterogeneity from technological point of view. It is envisaged that in certain areas end-users will have a choice between various radio accesses (RAs) such as e.g. classical cellular networks (GSM, UMTS, WiMAX, etc), WLAN hot-spots, or o

  2. Clinical application with a hybrid PET/MRI system

    Composite image diagnosis using a hybrid PET/MRI system is beneficial comparing to individual diagnosis of PET functional images and MRI anatomical images in standalone systems. Because the hybrid PET/MRI system makes it possible to detect disease more accurately and quickly. Moreover, it improves staging evaluation, therapy monitoring and follow-up observation. The stand-alone PET and MRI systems have already been established as useful clinical methods and provides complementary information for each other. With the hybrid PET/MRI system, it is expected to cover a wider range of clinical application. In addition, the hybrid system enables us to get highly precise registration information and more accurate fusion images. (author)

  3. Head Access Piping System Desing

    中大路 道彦; 一宮 正和; 向坊 隆一; 前田 清彦; 永田 敬

    1994-01-01

    PNC made design studies on loop type FBR plants:a 600 MWe class in '91, and a 1300 MWe class in '93 both with the "head access" primary piping system. This paper focuses on the features of the smaller plant at first and afterwards on the extension to the larger one. The contents of the paper consist of R/V wall protection mechanism, primary piping circuit, secondary piping circuit, plant layout and then, discusses the extension of the applicability of the wall protection mechanism, primary pi...

  4. Primary care direct access MRI for the investigation of chronic headache

    Taylor, T.R., E-mail: timt@nhs.net [Queens Medical Centre, Nottingham (United Kingdom); Evangelou, N. [Queens Medical Centre, Nottingham (United Kingdom); Porter, H. [Nottingham Cripps Health Centre, Nottingham (United Kingdom); Lenthall, R. [Queens Medical Centre, Nottingham (United Kingdom)

    2012-01-15

    Aim: To assess the efficacy of a primary-care imaging pathway for neurology outpatients, from inception to deployment, compared with traditional outpatient referral. Materials and methods: After local agreement, guidelines were generated providing pathways for diagnosis and treatment of common causes of headache, highlighting 'red-flag' features requiring urgent neurology referral, and selecting patients for direct magnetic resonance imaging (MRI) referral. In addition, reports were clarified and standardized. To evaluate the efficacy of the access pathway, a retrospective sequential review of 100 MRI investigations was performed comparing general practitioner (GP) referral, with traditional neurology referral plus imaging, acquired before the pathway started. Results: No statistically significant difference in rates of major abnormalities, incidental findings or ischaemic lesions were identified between the two cohorts. Reported patient satisfaction was high, with a cost reduction for groups using the pathway. Conclusion: The findings of the present study suggest that a defined access pathway for imaging to investigate chronic headache can be deployed appropriately in a primary-care setting.

  5. MRI-based microrobotic system for the propulsion and navigation of ferromagnetic microcapsules

    Belharet, Karim; Folio, David; Ferreira, Antoine

    2010-01-01

    This paper presents real-time MRI-based control of a ferromagnetic microcapsule for endovascular navigation. The concept was studied for future development of microdevices designed to perform minimally invasive interventions in remote sites accessible through the human cardiovascular system. A system software architecture is presented illustrating the different software modules to allow 3-D navigation of a microdevice in blood vessels, namely: (i) vessel path planner, (ii) magnetic gradient s...

  6. A new access scheme in OFDMA systems

    GU Xue-lin; YAN Wei; TIAN Hui; ZHANG Ping

    2006-01-01

    This article presents a dynamic random access scheme for orthogonal frequency division multiple access (OFDMA) systems. The key features of the proposed scheme are:it is a combination of both the distributed and the centralized schemes, it can accommodate several delay sensitivity classes,and it can adjust the number of random access channels in a media access control (MAC) frame and the access probability according to the outcome of Mobile Terminals access attempts in previous MAC frames. For floating populated packet-based networks, the proposed scheme possibly leads to high average user satisfaction.

  7. A Spectral-Scanning Magnetic Resonance Imaging (MRI) Integrated System

    Hassibi, Arjang; Babakhani, Aydin; Hajimiri, Ali

    2008-01-01

    An integrated spectral-scanning magnetic resonance imaging (MRI) technique is implemented in a 0.12μm SiGe BiCMOS process. This system is designed for small-scale MRI applications with non-uniform and low magnetic fields. The system is capable of generating customized magnetic resonance (MR) excitation signals, and also recovering the MR response using a coherent direct conversion receiver. The operation frequency is tunable from DC to 37MHz for wide-band MRI and up to...

  8. Interventional MRI: update

    Lufkin, R.B. [Department of Radiology, University of California Los Angeles, School of Medicine, 10 833 Le Comte Avenue, Los Angeles, CA 90024-1721 (United States); Gronemeyer, D.H.W.; Seibel, R.M.M. [Institute of Diagnostic and Interventional Radiology, Medical Computerscience, University Witten/Herdecke (Germany)

    1997-12-31

    Interventional MRI is in its early stages of development. Nevertheless, the design of new interventional MRI scanners that allow maximum direct access to the patient combined with the development of new interventional MRI pulse sequences and localization systems, means that the archetypal operating rooms of the 21st century may well contain dedicated interventional MRI units for combined radiological and surgical procedures. The present article looks at the state of interventional MRI today and looks ahead to what may be forthcoming in the not-too-distant future. After briefly discussing the instrumentation necessary for practical interventional MRI, the article will go on to describe a number of different approaches to, and clinical applications for, interventional MRI. The use of MRI in guiding and controlling tumor ablation, aspiration cytology and surgical biopsy of different body parts is described. (orig.) With 13 figs., 1 tab., 114 refs.

  9. Development of an outdoor MRI system for measuring flow in a living tree.

    Nagata, Akiyoshi; Kose, Katsumi; Terada, Yasuhiko

    2016-04-01

    An outdoor MRI system for noninvasive, long-term measurements of sap flow in a living tree in its natural environment has been developed. An open-access, 0.2 T permanent magnet with a 160 mm gap was combined with a radiofrequency probe, planar gradient coils, electromagnetic shielding, several electrical units, and a waterproofing box. Two-dimensional cross-sectional images were acquired for a ring-porous tree, and the anatomical structures, including xylem and phloem, were identified. The MRI flow measurements demonstrated the diurnal changes in flow velocity in the stem on a per-pixel basis. These results demonstrate that our outdoor MRI system is a powerful tool for studies of water transport in outdoor trees. PMID:26896868

  10. Development of an outdoor MRI system for measuring flow in a living tree

    Nagata, Akiyoshi; Kose, Katsumi; Terada, Yasuhiko

    2016-04-01

    An outdoor MRI system for noninvasive, long-term measurements of sap flow in a living tree in its natural environment has been developed. An open-access, 0.2 T permanent magnet with a 160 mm gap was combined with a radiofrequency probe, planar gradient coils, electromagnetic shielding, several electrical units, and a waterproofing box. Two-dimensional cross-sectional images were acquired for a ring-porous tree, and the anatomical structures, including xylem and phloem, were identified. The MRI flow measurements demonstrated the diurnal changes in flow velocity in the stem on a per-pixel basis. These results demonstrate that our outdoor MRI system is a powerful tool for studies of water transport in outdoor trees.

  11. Grain quality of drought tolerant accessions within the MRI Zemun Polje maize germplasm collection

    Jelena Vančetović

    2014-01-01

    Full Text Available Maize Research Institute Zemun Polje (MRI gene bank created an elite drought tolerant core collection of 40 accessions, based on field trials and general combining ability with inbred lines from the main heterotic groups (Lancaster, Iowa Stiff Stalk Synthetic - BSSS and Iodent. A total of seven genetic groups were identified. Seven accessions showed good combining abilities with three testers from chosen heterotic groups, thus forming a dinstinctive genetic group (Unknown. In the present research, accessions with drought tolerance were also analyzed for grain quality, as these two traits are becoming highly important due to global warming and population growth. Kernel macronutrients contents (oil, protein and starch were determined using Near Infrared Spectroscopy (NIR. Oil, protein and starch contents were significantly higher in introduced populations than in landraces for 0.43%, 0.12% and 0.85%, respectively (p<0.01. The greatest progress from the selection based on the expected genetic gain (ΔG for 5% selection intensity would be obtained for oil (14.74% followed by protein (10.14%. Landraces showed the least potential for the grain quality improvement due to the lowest expected ΔG for the three macronutrients. The differences between macronutrient content among genetic groups defined them as potentially favourable sources for a specific trait. According to ΔG values, the greatest progress in breeding would be accomplished for increased oil content with accessions from the Unknown group. Identification of the accessions with several favorable traits is valuable for simultaneous breeding for drought tolerance and grain quality.

  12. ACCESS Sub-system Performance

    Kaiser, Mary Elizabeth; Morris, Matthew J.; Aldoroty, Lauren Nicole; Godon, David; Pelton, Russell; McCandliss, Stephan R.; Kurucz, Robert L.; Kruk, Jeffrey W.; Rauscher, Bernard J.; Kimble, Randy A.; Wright, Edward L.; Benford, Dominic J.; Gardner, Jonathan P.; Feldman, Paul D.; Moos, H. Warren; Riess, Adam G.; Bohlin, Ralph; Deustua, Susana E.; Dixon, William Van Dyke; Sahnow, David J.; Lampton, Michael; Perlmutter, Saul

    2016-01-01

    ACCESS: Absolute Color Calibration Experiment for Standard Stars is a series of rocket-borne sub-orbital missions and ground-based experiments designed to leverage significant technological advances in detectors, instruments, and the precision of the fundamental laboratory standards used to calibrate these instruments to enable improvements in the precision of the astrophysical flux scale through the transfer of laboratory absolute detector standards from the National Institute of Standards and Technology (NIST) to a network of stellar standards with a calibration accuracy of 1% and a spectral resolving power of 500 across the 0.35 to 1.7 micron bandpass.A cross wavelength calibration of the astrophysical flux scale to this level of precision over this broad a bandpass is relevant for the data used to probe fundamental astrophysical problems such as the SNeIa photometry based measurements used to constrain dark energy theories.We will describe the strategy for achieving this level of precision, the payload and calibration configuration, present sub-system test data, and the status and preliminary performance of the integration and test of the spectrograph and telescope. NASA APRA sounding rocket grant NNX14AH48G supports this work.

  13. Easy Access: Auditing the System Network

    Wiech, Dean

    2013-01-01

    In today's electronic learning environment, access to appropriate systems and data is of the utmost importance to students, faculty, and staff. Without proper access to the school's internal systems, teachers could be prevented from logging on to an online learning system and students might be unable to submit course work to an online…

  14. Simultaneous imaging using Si-PM-based PET and MRI for development of an integrated PET/MRI system

    The silicon photomultiplier (Si-PM) is a promising photo-detector for PET for use in magnetic resonance imaging (MRI) systems because it has high gain and is insensitive to static magnetic fields. Recently we developed a Si-PM-based depth-of-interaction PET system for small animals and performed simultaneous measurements by combining the Si-PM-based PET and the 0.15 T permanent MRI to test the interferences between the Si-PM-based PET and an MRI. When the Si-PM was inside the MRI and installed around the radio frequency (RF) coil of the MRI, significant noise from the RF sequence of the MRI was observed in the analog signals of the PET detectors. However, we did not observe any artifacts in the PET images; fluctuation increased in the count rate of the Si-PM-based PET system. On the MRI side, there was significant degradation of the signal-to-noise ratio (S/N) in the MRI images compared with those without PET. By applying noise reduction procedures, the degradation of the S/N was reduced. With this condition, simultaneous measurements of a rat brain using a Si-PM-based PET and an MRI were made with some degradation in the MRI images. We conclude that simultaneous measurements are possible using Si-PM-based PET and MRI. (note)

  15. Access control and personal identification systems

    Bowers, Dan M

    1988-01-01

    Access Control and Personal Identification Systems provides an education in the field of access control and personal identification systems, which is essential in selecting the appropriate equipment, dealing intelligently with vendors in purchases of the equipment, and integrating the equipment into a total effective system. Access control devices and systems comprise an important part of almost every security system, but are seldom the sole source of security. In order for the goals of the total system to be met, the other portions of the security system must also be well planned and executed

  16. Modelling Access Control For Healthcare Information Systems

    Ferreira, Ana; Chadwick, David W; Antunes, Luis

    2007-01-01

    The widening use of Information Systems, which allow the collection, extraction, storage, management and search of information, is increasing the need for information security. After a user is successfully identified and authenticated to a system, he needs to be authorised to access the resources he/she requested. Access control is part of this last process that checks if a user can access those resources. This is particularly important in the healthcare environment where there is the need to...

  17. Quantitative Evaluation of the Reticuloendothelial System Function with Dynamic MRI

    Liu, Ting; Choi, Hoon; Zhou, Rong; Chen, I-Wei

    2014-01-01

    Purpose To evaluate the reticuloendothelial system (RES) function by real-time imaging blood clearance as well as hepatic uptake of superparamagnetic iron oxide nanoparticle (SPIO) using dynamic magnetic resonance imaging (MRI) with two-compartment pharmacokinetic modeling. Materials and Methods Kinetics of blood clearance and hepatic accumulation were recorded in young adult male 01b74 athymic nude mice by dynamic T2* weighted MRI after the injection of different doses of SPIO nanoparticles ...

  18. Multilingual Access for Information Systems.

    Peters, Carol; Sheridan, Paraic

    With the rapid growth of the global information society, the concept of library has evolved to embrace all kinds of information collections, on all kinds of storage media, and using many different access methods. The users of today's information networks and digital libraries, no longer restricted by geographic or spatial boundaries, want to be…

  19. Open Access and DSpace Institutional Repository System

    Çelik, Sönmez; Gürdal, Gültekin; Keten, Burcu; Türkfidanı, Ata; Kutlutürk, Levent

    2013-01-01

    The Open Access movement is a social movement in academia, dedicated to the principle of open access - to information - sharing for the common good and is being supported by many scientists, publishers, and researchers in the world, today. The software that is used to operate the institutional archive systems which are the basis of the Open Access, are divided into two forms of some free open source software and paid package programs which were developed by some corporates. DSpace, whose firs...

  20. CDC STATE System Tobacco Legislation - Youth Access

    U.S. Department of Health & Human Services — 1995-2016. Centers for Disease Control and Prevention (CDC). State Tobacco Activities Tracking and Evaluation (STATE) System. Legislation—Youth Access. The STATE...

  1. T₁ρ MRI of human musculoskeletal system.

    Wang, Ligong; Regatte, Ravinder R

    2015-03-01

    Magnetic resonance imaging (MRI) offers the direct visualization of the human musculoskeletal (MSK) system, especially all diarthrodial tissues including cartilage, bone, menisci, ligaments, tendon, hip, synovium, etc. Conventional MRI techniques based on T1 - and T2 -weighted, proton density (PD) contrast are inconclusive in quantifying early biochemically degenerative changes in MSK system in general and articular cartilage in particular. In recent years, quantitative MR parameter mapping techniques have been used to quantify the biochemical changes in articular cartilage, with a special emphasis on evaluating joint injury, cartilage degeneration, and soft tissue repair. In this article we focus on cartilage biochemical composition, basic principles of T1ρ MRI, implementation of T1ρ pulse sequences, biochemical validation, and summarize the potential applications of the T1ρ MRI technique in MSK diseases including osteoarthritis (OA), anterior cruciate ligament (ACL) injury, and knee joint repair. Finally, we also review the potential advantages, challenges, and future prospects of T1ρ MRI for widespread clinical translation. PMID:24935818

  2. Clinical application of MRI to fetal central nervous system

    Objective: To explore the value of MRI on fetal central nervous system. Methods: Twenty-four women with complicated pregnancies, aged from 22 to 32 years (average 27 years) and with gestation from 23-39 weeks (average 30 weeks) were studied with a 1.5T superconductive MR unit within 24 hours after ultrasound studies. T2-weighted MR imaging was performed using HASTE and T1-weighted MR imaging was using FLASH. Comparison of the diagnosis of MRI and ultrasound were done with autopsy or postnatal follow-up MRI. Results: Of the 24 cases, 24 fetus were found. The fetal brain, gyrus, sulcus, corpus callosum, thalamus, cerebellum, brain stem, and spinal cord were shown more clearly on MR T2-weighted images. T1-weighted images were not as good as T2-weighted images. Twenty-seven lesions were visualized by ultrasound and thirty-one by MRI in these twenty-four fetuses. By MRI study, two cases were conformed their ultrasound diagnosis, ten cases were completed their ultrasound diagnosis, and twelve cases were made the same diagnosis as ultrasound. Conclusion: MR has advantages in displaying fetal central nervous system anatomy over ultrasound, the quality of MR images is not affected by maternal somatotype, volume of amniotic fluid, fetal skull and the pelvic skeleton of pregnant women. Based on ultrasound, MR imaging is a valuable complement to sonography in difficult cases, it can conforming, completing, even more correcting the diagnosis made by ultrasound. (authors)

  3. Fetal central nervous system anomalies: fast MRI vs ultrasonography

    Objective: To evaluate the ability of fast MRI to detect fetal central nervous system (CNS) anomalies and to compare its performance with that of prenatal ultrasonography (US). Methods Forty-eight pregnant women were detected by conventional prenatal US and MRI. Twenty-two fetuses with CNS anomalies were conformed by autopsy and follow-up. The MR and US appearances of fetal CNS structure were compared to each other and to that of autopsy. Results: A total of 26 CNS anomalies were identified by autopsy (n=17) and follow-up (n=9) including anencephaly (n=6), rachischisis (n=2), encephalocele (n=3), congenital hydrocephalus (n=7), alobar holoprosencephaly (n=1), porencephalia (n=3), arachnoid cyst (n=2) and choroids plexus cyst (n=2). US diagnosed 24 CNS anomalies, the correct diagnostic rate was 92.3%, the false-positive rate was 3.8%, the missed-diagnostic rate was 3.8%. MRI diagnosed 23 CNS anomalies, the correct-diagnostic rate was 88.5%, the false-positive rate was 3.8% ,the missed-diagnostic rate was 7.7%. There was no difference between US and MRI (P>0.05), but MRI have larger FOV, higher tissues resolution, and can demonstrate gray-white matter in detail. Conclusions: MR imaging has a similar sensitivity to that of US in the detection of fetal CNS anomalies. (authors)

  4. An MRI-compatible hand sensory vibrotactile system

    Recently, the application of vibrotactile noise to the wrist or back of the hand has been shown to enhance fingertip tactile sensory perception (Enders et al 2013), supporting the potential for an assistive device worn at the wrist, that generates minute vibrations to help the elderly or patients with sensory deficit. However, knowledge regarding the detailed physiological mechanism behind this sensory improvement in the central nervous system, especially in the human brain, is limited, hindering progress in development and use of such assistive devices. To enable investigation of the impact of vibrotactile noise on sensorimotor brain activity in humans, a magnetic resonance imaging (MRI)-compatible vibrotactile system was developed to provide vibrotactile noise during an MRI of the brain. The vibrotactile system utilizes a remote (outside the MR room) signal amplifier which provides a voltage from –40 to +40 V to drive a 12 mm diameter piezoelectric vibrator (inside the MR room). It is portable and is found to be MRI-compatible which enables its use for neurologic investigation with MRI. The system was also found to induce an improvement in fingertip tactile sensation, consistent with the previous study. (note)

  5. Perfusion MRI in neuro-psychiatric systemic lupus erthemathosus.

    Emmer, B.J.; Osch, M.J. van; Wu, O.; Steup-Beekman, G.M.; Steens, S.; Huizinga, T.W.J.; Buchem, M.A. van; Grond, J. van der

    2010-01-01

    PURPOSE: To use perfusion weighted MR to quantify any perfusion abnormalities and to determine their contribution to neuropsychiatric (NP) involvement in systemic lupus erythematosus (SLE). MATERIALS AND METHODS: We applied dynamic susceptibility contrast (DSC) perfusion MRI in 15 active NPSLE, 26 i

  6. Access Control Management for SCADA Systems

    Hong, Seng-Phil; Ahn, Gail-Joon; Xu, Wenjuan

    The information technology revolution has transformed all aspects of our society including critical infrastructures and led a significant shift from their old and disparate business models based on proprietary and legacy environments to more open and consolidated ones. Supervisory Control and Data Acquisition (SCADA) systems have been widely used not only for industrial processes but also for some experimental facilities. Due to the nature of open environments, managing SCADA systems should meet various security requirements since system administrators need to deal with a large number of entities and functions involved in critical infrastructures. In this paper, we identify necessary access control requirements in SCADA systems and articulate access control policies for the simulated SCADA systems. We also attempt to analyze and realize those requirements and policies in the context of role-based access control that is suitable for simplifying administrative tasks in large scale enterprises.

  7. Optimized access to distributed relational database system

    Hrivnac, J.

    2006-01-01

    Efficient and friendly access to the large amount of data distributed over the wide area network is a challenge for the near future LCG experiments. The problem can be solved using current standard open technologies and tools. A JDBC standard soution has been chosen as a base for a comprehensive system for the relational data access and management. Widely available open tools have been reused and extended to satisfy HEP needs.

  8. Performance estimates for personnel access control systems

    Bradley, R. G.

    1980-10-01

    Current performance estimates for personnel access control systems use estimates of Type I and Type II verification errors. A system performance equation which addresses normal operation, the insider, and outside adversary attack is developed. Examination of this equation reveals the inadequacy of classical Type I and II error evaluations which require detailed knowledge of the adversary threat scenario for each specific installation. Consequently, new performance measures which are consistent with the performance equation and independent of the threat are developed as an aid in selecting personnel access control systems.

  9. Performance estimates for personnel access control systems

    Current performance estimates for personnel access control systems use estimates of Type I and Type II verification errors. A system performance equation which addresses normal operation, the insider, and outside adversary attack is developed. Examination of this equation reveals the inadequacy of classical Type I and II error evaluations which require detailed knowledge of the adversary threat scenario for each specific installation. Consequently, new performance measures which are consistent with the performance equation and independent of the threat are developed as an aid in selecting personnel access control systems

  10. Distributed Access View Integrated Database (DAVID) system

    Jacobs, Barry E.

    1991-01-01

    The Distributed Access View Integrated Database (DAVID) System, which was adopted by the Astrophysics Division for their Astrophysics Data System, is a solution to the system heterogeneity problem. The heterogeneous components of the Astrophysics problem is outlined. The Library and Library Consortium levels of the DAVID approach are described. The 'books' and 'kits' level is discussed. The Universal Object Typer Management System level is described. The relation of the DAVID project with the Small Business Innovative Research (SBIR) program is explained.

  11. Access Control in Data Management Systems

    Ferrari, Elena

    2010-01-01

    Access control is one of the fundamental services that any Data Management System should provide. Its main goal is to protect data from unauthorized read and write operations. This is particularly crucial in today's open and interconnected world, where each kind of information can be easily made available to a huge user population, and where a damage or misuse of data may have unpredictable consequences that go beyond the boundaries where data reside or have been generated. This book provides an overview of the various developments in access control for data management systems. Discretionary,

  12. Totally Accessible MRI A User's Guide to Principles, Technology, and Applications

    Lipton, Michael L

    2008-01-01

    This is a practical guide that offers a lucid introduction to the principles of MRI physics. The author, recognized in the imaging community for his exceptional teaching methods and lectures, has written an easy to understand text. Each chapter explains the "why" and "how" behind MRI physics. Readers will understand how altering MRI parameters will have many different consequences for image quality and the speed in which images are generated. Practical topics, selected for their value to clinical practice, include progressive changes in key MRI parameters, imaging time, and signal to noise ratio. A wealth of high quality illustrations, complemented by concise text, enables readers to gain a thorough understanding of the subject without requiring prior in-depth knowledge

  13. A wireless communication system for interventional MRI

    The available MR-compatible communication systems, which are typically designed for diagnostic exams, are mostly based on tubular sound transmission. In other settings, modern commercially available communication systems with ear protection allow wireless communication in noisy environments. The application of MR-compatible wireless headsets in interventional radiology precludes tube contact with sterile surfaces and hindrance of the interventionalist's range of motion. The system introduced here allows wireless communication within the scanner room without influencing MR image quality. (orig.)

  14. Safety testing for LHC access system

    Valentini, F; Ninin, P; Scibile, S

    2008-01-01

    In the domain of Safety Real-Time Systems the problem of testing represents always a big effort in terms of time, costs and efficiency to guarantee an adequate coverage degree. Exhaustive tests may, in fact, not be practicable for large and distributed systems. This paper describes the testing process followed during the validation of the CERN's LHC Access System [1], responsible for monitoring and preventing physical risks for the personnel accessing the underground areas. In the paper we also present a novel strategy for the testing problem, intended to drastically reduce the time for the test patterns generation and execution. In particular, we propose a methodology for blackbox testing that relies on the application of Model Checking techniques. Model Checking is a formal method from computer science, commonly adopted to prove correctness of system’s models through an automatic system’s state space exploration against some property formulas.

  15. Fetal MRI of the urinary system

    Hoermann, Marcus [Department of Radiodiagnostics, Medical University of Vienna, Waehringerguertel 18-20, A-1090 Vienna (Austria)]. E-mail: marcus.hoermann@meduniwien.ac.at; Brugger, Peter C. [Center of Anatomy and Cell Biology, Medical University of Vienna (Austria); Balassy, Csilla [Department of Radiodiagnostics, Medical University of Vienna, Waehringerguertel 18-20, A-1090 Vienna (Austria); Witzani, Linde [Department of Radiodiagnostics, Medical University of Vienna, Waehringerguertel 18-20, A-1090 Vienna (Austria); Prayer, Daniela [Department of Radiodiagnostics, Medical University of Vienna, Waehringerguertel 18-20, A-1090 Vienna (Austria)

    2006-02-15

    The assessment of the urinary system is typically performed by ultrasound. Nevertheless, an ultrasound may be inconclusive in fetuses with renal diseases that result in anhydramnios or oligohydramnios. In such cases, and in other cases in which ultrasound is limited, further investigation with MR should be considered. In the following article, we will provide an overview of the most commonly encountered disorders of the urinary system and their appearance on fetal MR imaging. Fetal MR imaging can accurately diagnose a wide variety of urinary tract disorders and must be seen as a valuable complementary tool to ultrasound in the assessment of the urinary system, particularly in cases of inconclusive ultrasound findings.

  16. Fetal MRI of the urinary system

    The assessment of the urinary system is typically performed by ultrasound. Nevertheless, an ultrasound may be inconclusive in fetuses with renal diseases that result in anhydramnios or oligohydramnios. In such cases, and in other cases in which ultrasound is limited, further investigation with MR should be considered. In the following article, we will provide an overview of the most commonly encountered disorders of the urinary system and their appearance on fetal MR imaging. Fetal MR imaging can accurately diagnose a wide variety of urinary tract disorders and must be seen as a valuable complementary tool to ultrasound in the assessment of the urinary system, particularly in cases of inconclusive ultrasound findings

  17. LANSCE personnel access control system (PACS)

    The Radiation Security System (RSS) at the Los Alamos Neutron Science Center (LANSCE) provides personnel protection from prompt radiation due to accelerated beam. The Personnel Access Control System (PACS) is a component of the RSS that is designed to prevent personnel access to areas where prompt radiation is a hazard. PACS was designed to replace several older personnel safety systems (PSS) with a single modem unified design. Lessons learned from the operation over the last 20 years were incorporated into a redundant sensor, single-point failure safe, fault tolerant, and tamper-resistant system that prevents access to the beam areas by controlling the access keys and beam stoppers. PACS uses a layered philosophy to the physical and electronic design. The most critical assemblies are battery backed up, relay logic circuits; less critical devices use Programmable Logic Controllers (PLCs) for timing functions and communications. Outside reviewers have reviewed the operational safety of the design. The design philosophy, lessons learned, hardware design, software design, operation, and limitations of the device are described

  18. Cardea: Dynamic Access Control in Distributed Systems

    Lepro, Rebekah

    2004-01-01

    Modern authorization systems span domains of administration, rely on many different authentication sources, and manage complex attributes as part of the authorization process. This . paper presents Cardea, a distributed system that facilitates dynamic access control, as a valuable piece of an inter-operable authorization framework. First, the authorization model employed in Cardea and its functionality goals are examined. Next, critical features of the system architecture and its handling of the authorization process are then examined. Then the S A M L and XACML standards, as incorporated into the system, are analyzed. Finally, the future directions of this project are outlined and connection points with general components of an authorization system are highlighted.

  19. Simulation of spin dynamics: a tool in MRI system development

    Magnetic Resonance Imaging (MRI) is a routine diagnostic tool in the clinics and the method of choice in soft-tissue contrast medical imaging. It is an important tool in neuroscience to investigate structure and function of the living brain on a systemic level. The latter is one of the driving forces to further develop MRI technology, as neuroscience especially demands higher spatiotemporal resolution which is to be achieved through increasing the static main magnetic field, B0. Although standard MRI is a mature technology, ultra high field (UHF) systems, at B0 ≥ 7 T, offer space for new technical inventions as the physical conditions dramatically change. This work shows that the development strongly benefits from computer simulations of the measurement process on the basis of a semi-classical, nuclear spin-1/2 treatment given by the Bloch equations. Possible applications of such simulations are outlined, suggesting new solutions to the UHF-specific inhomogeneity problems of the static main field as well as the high-frequency transmit field.

  20. Obstacle Characterization in a Geocrowdsourced Accessibility System

    Qin, H.; Aburizaiza, A. O.; Rice, R. M.; Paez, F.; Rice, M. T.

    2015-08-01

    Transitory obstacles - random, short-lived and unpredictable objects - are difficult to capture in any traditional mapping system, yet they have significant negative impacts on the accessibility of mobility- and visually-impaired individuals. These transitory obstacles include sidewalk obstructions, construction detours, and poor surface conditions. To identify these obstacles and assist the navigation of mobility- and visually- impaired individuals, crowdsourced mapping applications have been developed to harvest and analyze the volunteered obstacles reports from local students, faculty, staff, and residents. In this paper, we introduce a training program designed and implemented for recruiting and motivating contributors to participate in our geocrowdsourced accessibility system, and explore the quality of geocrowdsourced data with a comparative analysis methodology.

  1. MRI findings of central nervous system granulocytic sarcoma (chloroma)

    To characterize MRI findings of central nervous system (CNS) granulocytic sarcoma (chloroma) and to analyse the points which differentiate it from other CNS tumors. We evaluated MRI in six patients with CNS granulocytic sarcoma proven by surgery or bone marrow biopsy (intracranical, one case and spine five cases). A 0.5T superconductive MR machine was used for diagnosis and, axial, coronal and sagittal T1- and T2-weighted spin echo images and Gd-DTPA enhanced T1-weighted images were obtained. We retrospectively analized the location, signal intensity, margin, contrast enhancement and homogeneity, and bony change around the tumor. MRI findings of CNS granulocytic sarcomas were as follows : one tumor was seen to be an extra-axial mass in the posterior fossa of the brain, four were epidural, and one was an epidural and presacral masses in the spine;tumor magins were lobulated and three were smooth. On T1-weighted images, all tumors were of isoignal intensity;on T2-weighted images, four were of isosignal intersity and two were of high signal intensity. Contrast enhancement was inhomogeneous in five of six cases. Bony change around the tumor was seen in two cases. On T1-weighted images, CNS granulocytic sarcomas (chloromas) were of isosignal intensity, relative to brain parenchyma or spinal cord;on T2-weighted images, they were of iso or high signal intensity, with relative contrast enhancement. These points could be useful in differentiating them from other CNS tumors

  2. Fast Access Data Acquisition System (FADAS)

    Our goal in this program is to develop Fast Access Data Acquisition System (FADAS) by combining the flexibility of Multilink's GaAs and InP electronics and electro-optics with an extremely high data rate for the efficient handling and transfer of collider experimental data. This novel solution is based on Multilink's and Los Alamos National Laboratory's (LANL) unique components and technologies for extremely fast data transfer, storage, and processing

  3. Clinical and MRI correlation in multiple system atrophy

    By using magnetic resonance imaging (MRI), we studied 11 patients with multiple system atrophy (MSA): 5 olivo-pontocerebellar atrophy (OPCA), 2 Shy-Drager syndrome (SDS), and 4 striatonigral degeneration (SND). The diagnoses of OPCA, SDS and SND were clinically made. The MR images were performed on 1.5 tesla MRI unit (Siemens Asahi Medical, Magnetom H15), using a T2-weighted spin echo (SE) sequence (TR: 2000-3000 ms, TE: 80-90 ms), a T1-weighted SE sequence (TR: 550, TE: 15), and a proton density-weighted (PD) SE sequence (TR: 2000-3000, TE: 12-22). In the patients with OPCA, MRI revealed cerebellar and brainstem atrophy and degeneration of pontine transverse fibers more marked than in the patients with SDS and SND. T2-weighted images showed low intensity in posterolateral putamina in one OPCA patient and all of SDS and SND patients. PD images demonstrated the abnormal slit-like high signals in posterolateral putamina in three SND. The degree of cerebellar ataxia was not well correlated with cerebellar and brainstem atrophy and degeneration of pontine transverse fibers. There was a positive correlation between the atrophy of cerebellum and brainstem and the duration of cerebellar ataxia. In most of the patients with Parkinsonism, MRI demonstrated abnormal low signals in putamina on T2-weighted images. There were positive correlations between the abnormal low signals putamina and the duration and severity of Parkinsonism. Though abnormal low signals in lateral putamina may be seen in normal aging and other disorders on T2-weighted images, it is useful to evaluate Parkinsonism in MSA. We believe that the abnormal slit-like high signals in posterolateral putamina in MSA may suggest loss of neurons and gliosis. (author)

  4. OMERACT Rheumatoid Arthritis Magnetic Resonance Imaging Studies. Core set of MRI acquisitions, joint pathology definitions, and the OMERACT RA-MRI scoring system

    Østergaard, Mikkel; Peterfy, C; Conaghan, P;

    2003-01-01

    This article describes the 2002 OMERACT rheumatoid arthritis magnetic resonance image scoring system (RAMRIS) for evaluation of inflammatory and destructive changes in RA hands and wrists, which was developed by an international MRI-OMERACT group. MRI definitions of important RA joint pathologies......, and a 'core set' of basic MRI sequences for use in RA are also suggested...

  5. Analysis of systemic lupus erythematosus (SLE) involving the central nervous system by magnetic resonance imaging (MRI)

    Involvement of the central nervous system (CNS) commonly occurs in systemic lupus erythematosus (SLE). But definitive diagnosis remains difficult even with computed tomography (CT). In this study, we used the recently developed technique, magnetic resonance imaging (MRI) for CNS lupus and compared it with CT scans. CT was performed with a General Electric 8800 CT/T scanner. MRI was performed using a Mitsubishi Electric MMI-150 S. Ten patients with CNS lupus were divided into 3 groups. Group I included 4 cases with neurological manifestations alone. All lesions seen on CT were also detected by MRI, with greater clarity and extent. Furthermore, MRI depicted several microinfarcts in white matter without symptoms. Group II included 5 cases with psychiatric features alone. MRI detected a thalamic microinfarct in only one case while CT showed no abnormality in all cases. Group III included 1 case with both neurological and psychiatric symptoms. MRI demonstrated a small infarct of midbrain corresponding with neurological symptoms, more clearly than CT. Therefore MRI demonstrates the degree of brain involvement in SLE more accurately than CT. (author)

  6. Value of prenatal MRI in early evaluation of fetal central nervous system anomalies

    Kobayashi, Keiichi [Kugayama Hospital, Tokyo (Japan); Nakamura, Masanao; Hino, Ken [Kyorin Univ., Mitaka, Tokyo (Japan). School of Medicine] [and others

    2002-08-01

    Advances in technology and the need for accurate prenatal diagnoses have produced great improvements in fetal diagnosis by MRI. However, there are still many problems with diagnosis of central nervous system (CNS) anomalies using MRI (e.g., time of diagnosis, factors limiting diagnostic ability. Fifteen cases referred to our clinic from 1992 to 2001 and examined using intrauterine ultrasound, prenatal MRI and postnatal MRI were reviewed retrospectively. All clinical records and findings from prenatal MRI, postnatal MRI and ultrasound were reviewed. Prenatal MRI was found to be equal in diagnostic power to ultrasound and postnatal MRI in 10 of the 15 cases. In the remaining 5 fetuses, the findings of prenatal MRI were not the same to those of prenatal ultrasound and postnatal MRI. Our goal was to determine the value of prenatal MRI in diagnosis of fetal CNS anomalies, to ascertain how this information might be used for counseling, and to assess its impact on pregnancy management. Prenatal MRI provided useful information for support personnel (e.g., physicians, nurses, caseworkers, religious advisers). (author)

  7. OMERACT Rheumatoid Arthritis Magnetic Resonance Imaging Studies. Core set of MRI acquisitions, joint pathology definitions, and the OMERACT RA-MRI scoring system

    Østergaard, Mikkel; Peterfy, C; Conaghan, P;

    2003-01-01

    This article describes the 2002 OMERACT rheumatoid arthritis magnetic resonance image scoring system (RAMRIS) for evaluation of inflammatory and destructive changes in RA hands and wrists, which was developed by an international MRI-OMERACT group. MRI definitions of important RA joint pathologies......, and a 'core set' of basic MRI sequences for use in RA are also suggested......This article describes the 2002 OMERACT rheumatoid arthritis magnetic resonance image scoring system (RAMRIS) for evaluation of inflammatory and destructive changes in RA hands and wrists, which was developed by an international MRI-OMERACT group. MRI definitions of important RA joint pathologies...

  8. Science information systems: Archive, access, and retrieval

    Campbell, William J.

    1991-01-01

    The objective of this research is to develop technology for the automated characterization and interactive retrieval and visualization of very large, complex scientific data sets. Technologies will be developed for the following specific areas: (1) rapidly archiving data sets; (2) automatically characterizing and labeling data in near real-time; (3) providing users with the ability to browse contents of databases efficiently and effectively; (4) providing users with the ability to access and retrieve system independent data sets electronically; and (5) automatically alerting scientists to anomalies detected in data.

  9. Decentralized energy systems for clean electricity access

    Alstone, Peter; Gershenson, Dimitry; Kammen, Daniel M.

    2015-04-01

    Innovative approaches are needed to address the needs of the 1.3 billion people lacking electricity, while simultaneously transitioning to a decarbonized energy system. With particular focus on the energy needs of the underserved, we present an analytic and conceptual framework that clarifies the heterogeneous continuum of centralized on-grid electricity, autonomous mini- or community grids, and distributed, individual energy services. A historical analysis shows that the present day is a unique moment in the history of electrification where decentralized energy networks are rapidly spreading, based on super-efficient end-use appliances and low-cost photovoltaics. We document how this evolution is supported by critical and widely available information technologies, particularly mobile phones and virtual financial services. These disruptive technology systems can rapidly increase access to basic electricity services and directly inform the emerging Sustainable Development Goals for quality of life, while simultaneously driving action towards low-carbon, Earth-sustaining, inclusive energy systems.

  10. [Framework design of MRI guided phased HIFU system and software development].

    Ma, Ruifeng; Shen, Guofeng; Qiao, Shan; Wei, Bo; Chen, Sheng; Chen, Yazhu

    2013-03-01

    This paper introduced a new structure of MRI guided P-HIFU therapy system and software implementation based on the current P-HIFU system and interface provided by MRI vendor. The tests showed that the system's software can achieve the appropriate form of treatment need. PMID:23777061

  11. Quantitative evaluation of the reticuloendothelial system function with dynamic MRI.

    Ting Liu

    Full Text Available PURPOSE: To evaluate the reticuloendothelial system (RES function by real-time imaging blood clearance as well as hepatic uptake of superparamagnetic iron oxide nanoparticle (SPIO using dynamic magnetic resonance imaging (MRI with two-compartment pharmacokinetic modeling. MATERIALS AND METHODS: Kinetics of blood clearance and hepatic accumulation were recorded in young adult male 01b74 athymic nude mice by dynamic T2* weighted MRI after the injection of different doses of SPIO nanoparticles (0.5, 3 or 10 mg Fe/kg. Association parameter, Kin, dissociation parameter, Kout, and elimination constant, Ke, derived from dynamic data with two-compartment model, were used to describe active binding to Kupffer cells and extrahepatic clearance. The clodrosome and liposome were utilized to deplete macrophages and block the RES function to evaluate the capability of the kinetic parameters for investigation of macrophage function and density. RESULTS: The two-compartment model provided a good description for all data and showed a low sum squared residual for all mice (0.27±0.03. A lower Kin, a lower Kout and a lower Ke were found after clodrosome treatment, whereas a lower Kin, a higher Kout and a lower Ke were observed after liposome treatment in comparison to saline treatment (P<0.005. CONCLUSION: Dynamic SPIO-enhanced MR imaging with two-compartment modeling can provide information on RES function on both a cell number and receptor function level.

  12. Digital Autonomous Terminal Access Communication (DATAC) system

    Novacki, Stanley M., III

    1987-01-01

    In order to accommodate the increasing number of computerized subsystems aboard today's more fuel efficient aircraft, the Boeing Co. has developed the DATAC (Digital Autonomous Terminal Access Control) bus to minimize the need for point-to-point wiring to interconnect these various systems, thereby reducing total aircraft weight and maintaining an economical flight configuration. The DATAC bus is essentially a local area network providing interconnections for any of the flight management and control systems aboard the aircraft. The task of developing a Bus Monitor Unit was broken down into four subtasks: (1) providing a hardware interface between the DATAC bus and the Z8000-based microcomputer system to be used as the bus monitor; (2) establishing a communication link between the Z8000 system and a CP/M-based computer system; (3) generation of data reduction and display software to output data to the console device; and (4) development of a DATAC Terminal Simulator to facilitate testing of the hardware and software which transfer data between the DATAC's bus and the operator's console in a near real time environment. These tasks are briefly discussed.

  13. Diagnostic and interventional application of open gantry medium field MRI systems

    The authors presented advantages and limits in application of open gantry medium field MRI systems. These systems are used in diagnosis of bone joints injuries and in application of interventional techniques (e.g. endoscopy). In mammographic diagnostics stereotactic biopsy of the changes under control of MRI is possible

  14. Research of user access control for networked manufacturing system

    ZHENG Xiao-lin; LEI Yu; CHEN De-ren

    2006-01-01

    An integrated user access control method was proposed to address the issues of security and management in networked manufacturing systems (NMS).Based on the analysis of the security issues in networked manufacturing system,an integrated user access control method composed of role-based access control (RBAC),task-based access control (TBAC),relationship-driven access control (RDAC)and coalition-based access control (CBAC) was proposed,including the hierarchical user relationship model,the reference model and the process model.The elements and their relationships were defined,and the expressions of constraints authorization were given.The extensible access control markup language (XACML) was used to implement this method.This method was used in the networked manufacturing system in the Shaoxing spinning region of China.The results show that the integrated user access control method can reduce the costs of system security maintenance and management.

  15. Online Access to Knowledge: System Design.

    Meadow, Charles T.; And Others

    1989-01-01

    Reports on design and rationale of Online Access to Knowledge, a computer intermediary developed by Online Access to Knowledge Project to enable users with little or no training or experience in bibliographic searching to conduct their own searches. Topics covered include software design, tutorials and assistance programs, and conclusions based on…

  16. Context-Based E-Health System Access Control Mechanism

    Al-Neyadi, Fahed; Abawajy, Jemal H.

    E-Health systems logically demand a sufficiently fine-grained authorization policy for access control. The access to medical information should not be just role-based but should also include the contextual condition of the role to access data. In this paper, we present a mechanism to extend the standard role-based access control to incorporate contextual information for making access control decisions in e-health application. We present an architecture consisting of authorisation and context infrastructure that work cooperatively to grant access rights based on context-aware authorization policies and context information.

  17. Diffusion microscopist simulator - The development and application of a Monte Carlo simulation system for diffusion MRI

    Diffusion magnetic resonance imaging (dMRI) has made a significant breakthrough in neurological disorders and brain research thanks to its exquisite sensitivity to tissue cyto-architecture. However, as the water diffusion process in neuronal tissues is a complex biophysical phenomena at molecular scale, it is difficult to infer tissue microscopic characteristics on a voxel scale from dMRI data. The major methodological contribution of this thesis is the development of an integrated and generic Monte Carlo simulation framework, 'Diffusion Microscopist Simulator' (DMS), which has the capacity to create 3D biological tissue models of various shapes and properties, as well as to synthesize dMRI data for a large variety of MRI methods, pulse sequence design and parameters. DMS aims at bridging the gap between the elementary diffusion processes occurring at a micrometric scale and the resulting diffusion signal measured at millimetric scale, providing better insights into the features observed in dMRI, as well as offering ground-truth information for optimization and validation of dMRI acquisition protocols for different applications. We have verified the performance and validity of DMS through various benchmark experiments, and applied to address particular research topics in dMRI. Based on DMS, there are two major application contributions in this thesis. First, we use DMS to investigate the impact of finite diffusion gradient pulse duration (delta) on fibre orientation estimation in dMRI. We propose that current practice of using long delta, which is enforced by the hardware limitation of clinical MRI scanners, is actually beneficial for mapping fibre orientations, even though it violates the underlying assumption made in q-space theory. Second, we employ DMS to investigate the feasibility of estimating axon radius using a clinical MRI system. The results suggest that the algorithm for mapping the direct microstructures is applicable to dMRI data acquired from

  18. Campus Access Control System RFID Based

    Mr. SANTHOSH S

    2012-06-01

    Full Text Available Radio frequency identification (RFID technology has helped many organizations to reduce cost. Nevertheless, there are challenges and issues associated with RFID adoption. The most common internal challenge for many organizations is justifying the investment and modification of processes. The focus of this project is to show the business value of RFID technology and its applications. The important issue is the security level of the whole campus because it needs to be carefully differentiated. Dormitories and special research laboratories should benefit from higher levels of security than any other campuses. The key to the problem is represented by the new Radio Frequency Identification (RFID which can support contactless cards with memory. The most important feature of the proposed system is the updating of access permission level at any time for the user based on the availability of that user. The data transfer from the reader to the database was done using wireless communication (RF communication. To achieve this here RF transmitter and the RF receiver is used. The data which is read by the reader is sent to the microcontroller. Then from the controller we can transfer the data to the database by using the UART module (serial communication which is inbuilt in the microcontroller through RF transmitter. RF receiver of the same frequency at the receiver end receives and then stores the data in the database. RF transmitter and Receiver – frequency for transmitting and receiving the data depends on the user as per the requirement for the application and it is based on the range of distance. For the data encoding and decoding process HCS-101 protocol is used.

  19. MRI-guided abdominal biopsy in a 0.23-T open-configuration MRI system

    Kariniemi, J.; Blanco Sequeiros, R.; Ojala, R.; Tervonen, O. [University Hospital of Oulu Radiology, Oulu (Finland)

    2005-06-01

    The purpose of this study was to test the hypothesis that when ultrasound (US) guidance is not feasible, abdominal biopsies can be performed safely and accurately under magnetic resonance imaging (MRI) guidance in a low-field environment. MRI-guided abdominal biopsy was performed on 31 consecutive patients, in whom US-guided abdominal biopsy was not possible because the lesion was not visualized in US (n=27) or an US-guided procedure was not considered safe (n=4). The locations of the lesions were liver (n=14), pancreas (n=6), lymph node (n=4), retroperitoneal mass (n=3), adrenal gland (n=3) and spleen (n=1). The average size of the lesion was 2.2 cm (range 1-4 cm) in maximum diameter. All procedures were done by using a 0.23-T open-configuration C-arm-shaped MRI scanner with interventional optical tracking equipment and software. Fine-needle aspiration (FNA) biopsy was performed on all 31 patients; 18 patients underwent both FNA biopsy and cutting needle core biopsy. Procedures were evaluated for diagnostic sensitivity, specificity and accuracy as well as procedure time and complications. The FNA biopsy specimens were adequate for interpretation in 27 (87%) of 31 cases. Two of these proved to be false-negative findings during follow-up or subsequent biopsy. The final diagnosis was malignant in 15 and benign in 16 patients. The sensitivity, specificity and accuracy of FNA biopsy were 71, 100 and 81%, respectively. Of the 18 core-needle biopsies, one was determined false-negative owing to nonrepresentativeness. The sensitivity, specificity and accuracy of histological samples were 90, 100 and 94%, respectively. The needle time was 19 min on average and the mean room time was 1 h 48 min. No immediate or late complications occurred. MRI-guided abdominal biopsy can be performed safely and accurately in a low-field environment in patients for whom an US-guided procedure is not feasible. (orig.)

  20. The DAMASK trial protocol: a pragmatic randomised trial to evaluate whether GPs should have direct access to MRI for patients with suspected internal derangement of the knee

    Orchard Jo

    2006-10-01

    Full Text Available Abstract Background Though new technologies like Magnetic Resonance Imaging (MRI may be accurate, they often diffuse into practice before thorough assessment of their value in diagnosis and management, and of their effects on patient outcome and costs. MRI of the knee is a common investigation despite concern that it is not always appropriate. There is wide variation in general practitioners (GPs access to, and use of MRI, and in the associated costs. The objective of this study was to resolve uncertainty whether GPs should refer patients with suspected internal derangement of the knee for MRI or to an orthopaedic specialist in secondary care. Methods/Design The design consisted of a pragmatic multi-centre randomised trial with two parallel groups and concomitant economic evaluation. Patients presenting in general practice with suspected internal derangement of the knee and for whom their GP was considering referral to an orthopaedic specialist in secondary care were eligible for inclusion. Within practices, GPs or practice nurses randomised eligible and consenting participants to the local radiology department for an MRI examination, or for consultation with an orthopaedic specialist. To ensure that the waiting time from GP consultation to orthopaedic appointment was similar for both trial arms, GPs made a provisional referral to orthopaedics when requesting the MRI examination. Thus we evaluated the more appropriate sequence of events independent of variations in waiting times. Follow up of participants was by postal questionnaires at six, twelve and 24 months after randomisation. This was to ensure that the evaluation covered all events up to and including arthroscopy. Discussion The DAMASK trial should make a major contribution to the development of evidence-based partnerships between primary and secondary care professionals and inform the debate when MRI should enter the diagnostic pathway.

  1. Application Performance on the Direct Access File System

    Fedorova, Alexandra; Seltzer, Margo I.; Magoutis, Kostas; Addetia, Salimah

    2003-01-01

    The Direct Access File System (DAFS) is a distributed file system built on top of direct-access transports (DAT). Direct-access transports are characterized by using remote direct memory access (RDMA) for data transfer and user-level networking. The motivation behind the DAT-enabled distributed file system architecture is the reduction of the CPU overhead on the I/O data path. In collaboration with Duke University we have created and made available an open-source implementation of DAFS for th...

  2. Influence of the Application of MRI on the T, N Staging System of Nasopharyngeal Carcinoma

    ChuanmiaoXie; BilingLiang; HaogaoUn; PeihongWu

    2004-01-01

    OBJECTIVE To investigate the influence of utilizing MRI on the T, N staging system (the 5th edition, UICC) and on the 1992 China staging systems (Fuzhou-Guangzhou,China) by comparing the results of CT and MRI examinations of nasopharyngeal carcinoma (NPC).METHODS All 56 NPC patients, which were confirmed by histology,accepted both CT and MRI examinations. CT system scans were obtained by using an Elscient CT Twin Flash with the conventional axial scan. Three cases were examined by an additional coronary scan and 16 patients received an enhanced CT. The MR imaging was performed with a 0.5T MR system (Philips T5- II Ultra-Magnetic). The conventional axial, sagittal and coronary sections with SE sequences were obtained. The scan field was from the supra sellar cistern to the inferior border of C2. Most patients (50/56) accepted contrast enhanced MRI.RESULTS The pharyngobasilar fascia can clearly be seen on MRI but not on CT, so MRI can accurately determine the lesion in the nasopharyngeal cavity. MRI is more sensitive for evaluation of tumor involvement of soft tissue such as the Iongus colli muscle (14 cases by CT and 26 by MRI), tensor veli patalini muscle and levator veli palatini muscle (17 cases by CT and 23 by MRI), and skull-base bone marrow invasion (15 cases by CT and 42 by MRI). MRI can also demonstrate the invasion of the carotid sheath area and the enlargement of retropharyngeal lymph nodes more definitely than CT.The involvement of the trigeminal nerve can be detected on MRI, which may influence the clinical staging directly.CONCLUSION Of the 56 cases examined, 16 (28.6%) changed the staging based on UICC staging; while 33.9% (19/56) cases changed based on the 1992 China-stagin9 system. The major influence of MRI examinations on the 1992 staging was to differentiate the involvement of the carotid sheath area from metastasis of the retropharyngeal lymph nodes. There also was a significant difference in finding early invasion of the skull base.

  3. Multi-sensor system for simultaneous ultra-low-field MRI and MEG

    Zotev, V S; Matlachov, A N; Mosher, J C; Newman, S G; Sandin, H J; Urbaitis, A V; Volegov, P L

    2006-01-01

    Magnetoencephalography (MEG) and magnetic resonance imaging at ultra-low fields (ULF MRI) are two methods based on the ability of SQUID (superconducting quantum interference device) sensors to detect femtotesla magnetic fields. Combination of these methods will allow simultaneous functional (MEG) and structural (ULF MRI) imaging of the human brain. In this paper, we report the first implementation of a multi-sensor SQUID system designed for both MEG and ULF MRI. We present a multi-channel image of a human hand obtained at 46 microtesla field, as well as results of auditory MEG measurements with the new system.

  4. Characterization of acoustic noise in a neonatal intensive care unit MRI system

    To eliminate the medical risks and logistical challenges of transporting infants from the neonatal intensive care unit (NICU) to the radiology department for magnetic resonance imaging, a small-footprint 1.5-T MRI scanner has been developed for neonatal imaging within the NICU. MRI is known to be noisy, and exposure to excessive acoustic noise has the potential to elicit physiological distress and impact development in the term and preterm infant. To measure and compare the acoustic noise properties of the NICU MRI system against those of a conventional 1.5-T MRI system. We performed sound pressure level measurements in the NICU MRI scanner and in a conventional adult-size whole-body 1.5-T MRI system. Sound pressure level measurements were made for six standard clinical MR imaging protocols. The average sound pressure level value, reported in unweighted (dB) and A-weighted (dBA) decibels for all six imaging pulse sequences, was 73.8 dB and 88 dBA for the NICU scanner, and 87 dB and 98.4 dBA for the conventional MRI scanner. The sound pressure level values measured on the NICU scanner for each of the six MR imaging pulse sequences were consistently and significantly (P = 0.03) lower, with an average difference of 14.2 dB (range 10-21 dB) and 11 dBA (range 5-18 dBA). The sound pressure level frequency response of the two MR systems showed a similar harmonic structure above 200 Hz for all imaging sequences. The amplitude, however, was appreciably lower for the NICU scanner, by as much as 30 dB, for frequencies below 200 Hz. The NICU MRI system is quieter than conventional MRI scanners, improving safety for the neonate and facilitating siting of the unit within the NICU. (orig.)

  5. Characterization of acoustic noise in a neonatal intensive care unit MRI system

    Tkach, Jean A.; Li, Yu; Pratt, Ronald G.; Loew, Wolfgang; Daniels, Barret R.; Giaquinto, Randy O.; Dumoulin, Charles L. [Cincinnati Children' s Hospital Medical Center, Imaging Research Center, Department of Radiology, Cincinnati, OH (United States); Baroch, Kelly A. [Cincinnati Children' s Hospital Medical Center, Division of Audiology, Cincinnati, OH (United States); Merhar, Stephanie L. [Cincinnati Children' s Hospital Medical Center, Division of Neonatology and Pulmonary Biology, Perinatal Institute, Cincinnati, OH (United States); Kline-Fath, Beth M. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States)

    2014-08-15

    To eliminate the medical risks and logistical challenges of transporting infants from the neonatal intensive care unit (NICU) to the radiology department for magnetic resonance imaging, a small-footprint 1.5-T MRI scanner has been developed for neonatal imaging within the NICU. MRI is known to be noisy, and exposure to excessive acoustic noise has the potential to elicit physiological distress and impact development in the term and preterm infant. To measure and compare the acoustic noise properties of the NICU MRI system against those of a conventional 1.5-T MRI system. We performed sound pressure level measurements in the NICU MRI scanner and in a conventional adult-size whole-body 1.5-T MRI system. Sound pressure level measurements were made for six standard clinical MR imaging protocols. The average sound pressure level value, reported in unweighted (dB) and A-weighted (dBA) decibels for all six imaging pulse sequences, was 73.8 dB and 88 dBA for the NICU scanner, and 87 dB and 98.4 dBA for the conventional MRI scanner. The sound pressure level values measured on the NICU scanner for each of the six MR imaging pulse sequences were consistently and significantly (P = 0.03) lower, with an average difference of 14.2 dB (range 10-21 dB) and 11 dBA (range 5-18 dBA). The sound pressure level frequency response of the two MR systems showed a similar harmonic structure above 200 Hz for all imaging sequences. The amplitude, however, was appreciably lower for the NICU scanner, by as much as 30 dB, for frequencies below 200 Hz. The NICU MRI system is quieter than conventional MRI scanners, improving safety for the neonate and facilitating siting of the unit within the NICU. (orig.)

  6. Analysis of Access Control Policies in Operating Systems

    Chen, Hong

    2009-01-01

    Operating systems rely heavily on access control mechanisms to achieve security goals and defend against remote and local attacks. The complexities of modern access control mechanisms and the scale of policy configurations are often overwhelming to system administrators and software developers. Therefore, mis-configurations are common, and the…

  7. Speed control system for an access gate

    Bzorgi, Fariborz M.

    2012-03-20

    An access control apparatus for an access gate. The access gate typically has a rotator that is configured to rotate around a rotator axis at a first variable speed in a forward direction. The access control apparatus may include a transmission that typically has an input element that is operatively connected to the rotator. The input element is generally configured to rotate at an input speed that is proportional to the first variable speed. The transmission typically also has an output element that has an output speed that is higher than the input speed. The input element and the output element may rotate around a common transmission axis. A retardation mechanism may be employed. The retardation mechanism is typically configured to rotate around a retardation mechanism axis. Generally the retardation mechanism is operatively connected to the output element of the transmission and is configured to retard motion of the access gate in the forward direction when the first variable speed is above a control-limit speed. In many embodiments the transmission axis and the retardation mechanism axis are substantially co-axial. Some embodiments include a freewheel/catch mechanism that has an input connection that is operatively connected to the rotator. The input connection may be configured to engage an output connection when the rotator is rotated at the first variable speed in a forward direction and configured for substantially unrestricted rotation when the rotator is rotated in a reverse direction opposite the forward direction. The input element of the transmission is typically operatively connected to the output connection of the freewheel/catch mechanism.

  8. Testing the quality of images for permanent magnet desktop MRI systems using specially designed phantoms

    Our aim was to measure the performance of desktop magnetic resonance imaging (MRI) systems using specially designed phantoms, by testing imaging parameters and analysing the imaging quality. We designed multifunction phantoms with diameters of 18 and 60 mm for desktop MRI scanners in accordance with the American Association of Physicists in Medicine (AAPM) report no. 28. We scanned the phantoms with three permanent magnet 0.5 T desktop MRI systems, measured the MRI image parameters, and analysed imaging quality by comparing the data with the AAPM criteria and Chinese national standards. Image parameters included: resonance frequency, high contrast spatial resolution, low contrast object detectability, slice thickness, geometrical distortion, signal-to-noise ratio (SNR), and image uniformity. The image parameters of three desktop MRI machines could be measured using our specially designed phantoms, and most parameters were in line with MRI quality control criterion, including: resonance frequency, high contrast spatial resolution, low contrast object detectability, slice thickness, geometrical distortion, image uniformity and slice position accuracy. However, SNR was significantly lower than in some references. The imaging test and quality control are necessary for desktop MRI systems, and should be performed with the applicable phantom and corresponding standards. (paper)

  9. Delegation in Role Based Access Control Model for Workflow Systems

    Prasanna H Bammigatti

    2008-03-01

    Full Text Available Role -based access control (RBAC has been introduced in the last few years, and offers a powerful means of specifying access control decisions. The model of RBAC usually assumes that, if there is a role hierarchy then access rights are inherited upwards through the hierarchy. In organization workflow the main threat is of access control. The Role based access control is one of the best suitable access control model one can think of. It is not only the role hierarchies but also other control factors that affect the access control in the workflow. The paper discusses the control factors and role hierarchies in workflow and brings a new model of RBAC. This paper also over comes the conflicts and proves that the system is safe by applying the new model to the workflow

  10. Piezoelectrically Actuated Robotic System for MRI-Guided Prostate Percutaneous Therapy

    Su, Hao; Shang, Weijian; Cole, Gregory; Li, Gang; Harrington, Kevin; Camilo, Alexander; Tokuda, Junichi; Tempany, Clare M.; Hata, Nobuhiko; Fischer, Gregory S.

    2014-01-01

    This paper presents a fully-actuated robotic system for percutaneous prostate therapy under continuously acquired live magnetic resonance imaging (MRI) guidance. The system is composed of modular hardware and software to support the surgical workflow of intra-operative MRI-guided surgical procedures. We present the development of a 6-degree-of-freedom (DOF) needle placement robot for transperineal prostate interventions. The robot consists of a 3-DOF needle driver module and a 3-DOF Cartesian...

  11. A lifelogging system supporting multimodal access

    Qiu, Zhengwei

    2013-01-01

    Today, technology has progressed to allow us to capture our lives digitally such as taking pictures, recording videos and gaining access to WiFi to share experiences using smartphones. People’s lifestyles are changing. One example is from the traditional memo writing to the digital lifelog. Lifelogging is the process of using digital tools to collect personal data in order to illustrate the user’s daily life (Smith et al., 2011). The availability of smartphones embedded with different sensors...

  12. Is Your System Calibrated? MRI Gradient System Calibration for Pre-Clinical, High-Resolution Imaging

    James O'Callaghan; Jack Wells; Simon Richardson; Holly Holmes; Yichao Yu; Simon Walker-Samuel; Bernard Siow; Lythgoe, Mark F

    2014-01-01

    High-field, pre-clinical MRI systems are widely used to characterise tissue structure and volume in small animals, using high resolution imaging. Both applications rely heavily on the consistent, accurate calibration of imaging gradients, yet such calibrations are typically only performed during maintenance sessions by equipment manufacturers, and potentially with acceptance limits that are inadequate for phenotyping. To overcome this difficulty, we present a protocol for gradient calibration...

  13. Scheduling Heterogeneous Wireless Systems for Efficient Spectrum Access

    Lichun Bao

    2010-01-01

    Full Text Available The spectrum scarcity problem emerged in recent years, due to unbalanced utilization of RF (radio frequency bands in the current state of wireless spectrum allocations. Spectrum access scheduling addresses challenges arising from spectrum sharing by interleaving the channel access among multiple wireless systems in a TDMA fashion. Different from cognitive radio approaches which are opportunistic and noncollaborative in general, spectrum access scheduling proactively structures and interleaves the channel access pattern of heterogeneous wireless systems, using collaborative designs by implementing a crucial architectural component—the base stations on software defined radios (SDRs. We discuss our system design choices for spectrum sharing from multiple perspectives and then present the mechanisms for spectrum sharing and coexistence of GPRS+WiMAX and GPRS+WiFi as use cases, respectively. Simulations were carried out to prove that spectrum access scheduling is an alternative, feasible, and promising approach to the spectrum scarcity problem.

  14. ACCESS: Design and Sub-System Performance

    Kaiser, Mary Elizabeth; Morris, Matthew J.; McCandliss, Stephan R.; Rasucher, Bernard J.; Kimble, Randy A.; Kruk, Jeffrey W.; Pelton, Russell; Mott, D. Brent; Wen, Hiting; Foltz, Roger; Quijada, Manuel A.; Gum, Jeffery S.; Gardner, Jonathan P.; Kahle, Duncan M.; Benford, Dominic J.; Woodgate, Bruce E.; Wright, Edward L.; Feldman, Paul D.; Hart, Murdock; Moos, H. Warren; Reiss, Adam G.; Bohlin, Ralph; Deustua, Susana E.; Dixon, W. V.; Sahnow, David J.

    2012-01-01

    Establishing improved spectrophotometric standards is important for a broad range of missions and is relevant to many astrophysical problems. ACCESS, "Absolute Color Calibration Experiment for Standard Stars", is a series of rocket-borne sub-orbital missions and ground-based experiments designed to enable improvements in the precision of the astrophysical flux scale through the transfer of absolute laboratory detector standards from the National Institute of Standards and Technology (NIST) to a network of stellar standards with a calibration accuracy of 1% and a spectral resolving power of 500 across the 0.35 -1.7 micrometer bandpass.

  15. Third Degree Skin Burns Caused by an MRI Compatible Electrocardiographic Monitoring System

    Brix, Lau; Isaksen, Christin Rosendahl Graff; Kristensen, Birgitte Hornbæk;

    .0 Tesla MRI system. MRI sequences: Turbo Spin Echo (TSE) (ETL = 2-27, Scan time = 152-235 seconds), Flip Angles 135-160°, TR = 560-5423 ms). Both patients had elongated burns located on their bellies and therefore caused by the leads and not the electrodes. Both patients were sedated and the burns were...... marginal crossing of the assigned compatibility specifications of the leads due to the use of TFE sequences with high SAR values. MRI compatible monitoring systems are only safe when used with proper care. The presented burn cases may have been avoided if space had been provided between the ECG leads and......Introduction: The combination of increased magnetic field strength, field gradients and RF power, augments the risk of tissue heating in patients undergoing an MRI examination. This is especially important when the patients have implants or when external devices are in direct contact with the skin...

  16. Role Based Access Control system in the ATLAS experiment

    The complexity of the ATLAS experiment motivated the deployment of an integrated Access Control System in order to guarantee safe and optimal access for a large number of users to the various software and hardware resources. Such an integrated system was foreseen since the design of the infrastructure and is now central to the operations model. In order to cope with the ever growing needs of restricting access to all resources used within the experiment, the Roles Based Access Control (RBAC) previously developed has been extended and improved. The paper starts with a short presentation of the RBAC design, implementation and the changes made to the system to allow the management and usage of roles to control access to the vast and diverse set of resources. The RBAC implementation uses a directory service based on Lightweight Directory Access Protocol to store the users (∼3000), roles (∼320), groups (∼80) and access policies. The information is kept in sync with various other databases and directory services: human resources, central CERN IT, CERN Active Directory and the Access Control Database used by DCS. The paper concludes with a detailed description of the integration across all areas of the system.

  17. Role Based Access Control system in the ATLAS experiment

    Valsan, M. L.; Dobson, M.; Lehmann Miotto, G.; Scannicchio, D. A.; Schlenker, S.; Filimonov, V.; Khomoutnikov, V.; Dumitru, I.; Zaytsev, A. S.; Korol, A. A.; Bogdantchikov, A.; Avolio, G.; Caramarcu, C.; Ballestrero, S.; Darlea, G. L.; Twomey, M.; Bujor, F.

    2011-12-01

    The complexity of the ATLAS experiment motivated the deployment of an integrated Access Control System in order to guarantee safe and optimal access for a large number of users to the various software and hardware resources. Such an integrated system was foreseen since the design of the infrastructure and is now central to the operations model. In order to cope with the ever growing needs of restricting access to all resources used within the experiment, the Roles Based Access Control (RBAC) previously developed has been extended and improved. The paper starts with a short presentation of the RBAC design, implementation and the changes made to the system to allow the management and usage of roles to control access to the vast and diverse set of resources. The RBAC implementation uses a directory service based on Lightweight Directory Access Protocol to store the users (~3000), roles (~320), groups (~80) and access policies. The information is kept in sync with various other databases and directory services: human resources, central CERN IT, CERN Active Directory and the Access Control Database used by DCS. The paper concludes with a detailed description of the integration across all areas of the system.

  18. Disability standards and guidelines for learning management systems: Evaluating accessibility

    Moreno, Lourdes; Iglesias, Ana; Calvo, Rocío; Delgado, Sandra; Zaragoza, Luis

    2012-01-01

    Currently, the great majority of institutions of higher education use Learning Content Management Systems (LCMSs) and Learning Management Systems (LMS) as pedagogical tools. In order to make these systems accessible to all students, it is important to take into account not only educational standards, but also standards of accessibility. It is essential to have with procedures and well-established method for evaluating these tools, so in this paper we propose a method for evaluatin...

  19. Time division multiplexed orbital angular momentum access system

    Shi, Jianyang; Fang, Yuan; Chi, Nan

    2016-03-01

    We propose and experimentally demonstrate time division multiplexed orbital angular momentum (OAM) access system to increase transmission capacity and spectral efficiency. In this system, data carried on different time tributaries share the same OAM mode. Multiple time division multiplexed OAM modes are multiplexed to realize two-dimensional (time dimension and OAM dimension) multiplexing. Therefore, the capacity and spectral efficiency of the access system will increase. The orthogonality between optical time division multiplexing (OTDM) and OAM techniques is also verified in our experiment. In a proof-of-concept experiment, 2×5-Gbps return-to-zero signal over OAM mode +4 is transmitted and investigated. The bit error ratio performance after transmission in this system can be smaller than 1×10-9. Results show that the proposed time division multiplexed OAM access system is suitable for future broadband access network.

  20. Is your system calibrated? MRI gradient system calibration for pre-clinical, high-resolution imaging.

    James O'Callaghan

    Full Text Available High-field, pre-clinical MRI systems are widely used to characterise tissue structure and volume in small animals, using high resolution imaging. Both applications rely heavily on the consistent, accurate calibration of imaging gradients, yet such calibrations are typically only performed during maintenance sessions by equipment manufacturers, and potentially with acceptance limits that are inadequate for phenotyping. To overcome this difficulty, we present a protocol for gradient calibration quality assurance testing, based on a 3D-printed, open source, structural phantom that can be customised to the dimensions of individual scanners and RF coils. In trials on a 9.4 T system, the gradient scaling errors were reduced by an order of magnitude, and displacements of greater than 100 µm, caused by gradient non-linearity, were corrected using a post-processing technique. The step-by-step protocol can be integrated into routine pre-clinical MRI quality assurance to measure and correct for these errors. We suggest that this type of quality assurance is essential for robust pre-clinical MRI experiments that rely on accurate imaging gradients, including small animal phenotyping and diffusion MR.

  1. Clinical evaluation of shoulder kinematic MRI using an open-type system

    Previous studies on kinematic MRI of the shoulder using cylindrical-type MRI systems were limited to internal or external rotation. The open-type MRI system enables kinematic MRI to be carried out for the abductive position, and is expected to permit evaluation of the superior and inferior glenoid labrum. It is important to evaluate the superior and inferior glenoid labrum in cases of sports injuries (baseball, tennis, etc.). We evaluated the superior and inferior glenoid labrum for abductive motion in asymptomatic healthy volunteers as a preliminary study. As the abduction angle increased, the superior labrum moved into the joint space. Its shape changed from round or triangular to crescent (p<0.0001), and there was increased signal for larger abduction angles (p<0.0001). On the other hand, the shape of the inferior labrum tended to change from crescent to triangular or round (p<0.0001). Increased signal was seen in the inferior labrum on about half the shoulders (N.P.). This did not change as the abduction angle increased. Our results define normal patterns for the superior and inferior glenoid labrum on abductive kinematic MRI in healthy volunteers. Abductive kinematic studies using an open-type MRI system, which permits dynamic evaluation of the superior and inferior glenoid labrum, are expected to be useful for various patients with sports injuries. (author)

  2. Development of Nuclear Radiation monitoring simulation system of health access

    It introduces a nuclear radiation monitoring simulation system of health access. The main parameters of the software and hardware design and the system structure are described, the development of similar simulation system to provide some help an d guidance, the system design is based on radiation monitor of NPQJVC. (authors)

  3. BCH codes for large IC random-access memory systems

    Lin, S.; Costello, D. J., Jr.

    1983-01-01

    In this report some shortened BCH codes for possible applications to large IC random-access memory systems are presented. These codes are given by their parity-check matrices. Encoding and decoding of these codes are discussed.

  4. MULTIAGENT SYSTEM BASED ON GENETIC ACCESS MATRIX ANALYSIS

    Noto Masato

    2012-12-01

    Full Text Available How should an individual contribute to the public good? Conversely, how does the public help the individual? We should analyze and alleviate conflicts in community clouds. Covert channels in the access matrix are caused by conflicts between public values and a private sense of values. We cannot control the information leaks from the covert channels by using only access control. We believe that the community cloud system should emphasize harmony between public values and a private sense of values. We interpret the access matrix as follows: The acts of the individual are generalized and symbolized by an access matrix that describes the access operations of the subject. We propose a multiagent system embodying the concept of swarm intelligence to analyze the covert channels that arise. Each agent has a group target and an individual target. The group target and an individual target include targets for generation of access and restriction of access. The system does not have any principle of universal control. Instead, an agent’s interactions are guided by metaheuristics for achieving targets. The social order of the whole society is made from the agents’ interactions related to the group value target, group game target, an individual value target, and an individual game target. The conceptual framework and multiagent system presented here are intended to support people. If the covert channel problem can be solved, it will become possible for people to use community clouds safely.

  5. MRI of plants and foods.

    Van As, Henk; van Duynhoven, John

    2013-04-01

    The importance and prospects for MRI as applied to intact plants and to foods are presented in view of one of humanity's most pressing concerns, the sustainable and healthy feeding of a worldwide increasing population. Intact plants and foods have in common that their functionality is determined by complex multiple length scale architectures. Intact plants have an additional level of complexity since they are living systems which critically depend on transport and signalling processes between and within tissues and organs. The combination of recent cutting-edge technical advances and integration of MRI accessible parameters has the perspective to contribute to breakthroughs in understanding complex regulatory plant performance mechanisms. In food science and technology MRI allows for quantitative multi-length scale structural assessment of food systems, non-invasive monitoring of heat and mass transport during shelf-life and processing, and for a unique view on food properties under shear. These MRI applications are powerful enablers of rationally (re)designed food formulations and processes. Limitations and bottlenecks of the present plant and food MRI methods are mainly related to short T2 values and susceptibility artefacts originating from small air spaces in tissues/materials. We envisage cross-fertilisation of solutions to overcome these hurdles in MRI applications in plants and foods. For both application areas we witness a development where MRI is moving from highly specialised equipment to mobile and downscaled versions to be used by a broad user base in the field, greenhouse, food laboratory or factory. PMID:23369439

  6. Personnel Access Control System Evaluation for National Ignition Facility Operations

    Altenbach, T; Brereton, S.; Hermes, G.; Singh, M.

    2001-06-01

    The purpose of this document is to analyze the baseline Access Control System for the National Ignition Facility (NIF), and to assess its effectiveness at controlling access to hazardous locations during full NIF operations. It reviews the various hazards present during a NIF shot sequence, and evaluates the effectiveness of the applicable set of controls at preventing access while the hazards are present. It considers only those hazards that could potentially be lethal. In addition, various types of technologies that might be applicable at NIF are reviewed, as are systems currently in use at other facilities requiring access control for safety reasons. Recommendations on how this system might be modified to reduce risk are made.

  7. Evaluation of Brain and Cervical MRI Abnormality Rates in Patients With Systemic Lupus Erythematosus With or Without Neurological Manifestations

    Central nervous system (CNS) involvement has been observed in 14-80% of patients with systemic lupus erythematosus (SLE). Magnetic resonance imaging (MRI) is an appropriate method for evaluating CNS involvement in these patients. Clinical manifestations and MRI findings of CNS lupus should be differentiated from other mimicking diseases such as multiple sclerosis (MS). The aim of this study was to evaluate the prevalence and extent of brain and cervical cord MRI lesions of lupus patients. The relationship between neurological signs and symptoms and MRI findings were evaluated as well. Fifty SLE patients who had been referred to the rheumatology clinic of our hospital within 2009 were included in a cross sectional study. All patients fulfilled the revised 1981 American College of Rheumatology (ACR) criteria for SLE. We evaluated the neurological signs and symptoms and brain and cervical MRI findings in these patients. Forty-one patients (82%) were female and nine (18%) were male. The mean age was 30.1 ± 9.3 years. Twenty eight (56%) patients had an abnormal brain MRI. No one showed any abnormality in the cervical MRI. The lesions in 20 patients were similar to demyelinative plaques. Seventeen patients with abnormal brain MRI were neurologically asymptomatic. There was only a significant relationship between neurological motor manifestations and brain MRI abnormal findings. Unlike the brain, cervical MRI abnormality and especially asymptomatic cord involvement in MRI is quite rare in SLE patients. This finding may be helpful to differentiate SLE from other CNS disorders such as MS

  8. Hand and wrist imaging using a low-field dedicated MRI system

    Purpose of this study was to evaluate the diagnostic value of a low field dedicated MRI system in hand and wrist imaging. All 308 exams of the hand and wrist, that were performed on a low-field dedicated MRI system (Artoscan, Esaote Biomedica, Italy) in our institution in 1996, and high-field MRI exams performed in addition as part of the diagnostic work-up, were evaluated and correlated to final operative (n=64) and histologic (n=12) reports. 90% of all low-field MRI scans stated a diagnosis according to clinical suspicion. In 62% the clinical question was answered, and in 26% additional pathologies were identified. An MR-diagnosis completely different from the clinical suspicion was stated in 2%. High field exams contributed additional information in 6 to 36 patients. In 3 patients a tumor was not shown completely in the limited field-of-view of the dedicated low-field MRI-system. Frequency-selective fat-suppression pulse sequences and a better spatial resolution were the reasons for the additional information obtained in the other three patients. Low-field dedicted MR-imaging is a valuable method in the extensive work-up of the hand and wrist. Osseous, ligamentous and tendinous pathologies are well depicted. Large or infiltrative tumors should be referred to a high-field system. (orig.)

  9. Immediate data access system for LHD experiments

    Several kinds of computer systems are used to perform large helical device (LHD) experiments, and each produces its own data format. Therefore, it has been difficult to deal with these data simultaneously. In order to solve this problem, the Kaiseki server was developed; it has been facilitating the unified retrieval of LHD data. The data acquired or analyzed by various computer systems are converted into the unified ASCII format, or Kaiseki format, and transferred to the Kaiseki server. With this method, the researchers can visualize and analyze the data produced by various kinds of computers in the same way. Because validations are needed before registering on the Kaiseki server, it takes time to make the validated data available. However, some researchers need data as soon as it is gathered in order to adjust their instruments during the experiments. To satisfy this requirement, a new visualization system has been under development. The new system has two ways to visualize the data as physical values from the raw data. If the conversion task is not complex, the NIFSscope, a visualization tool, converts the raw data into physics data by itself. If the task is too complex to handle, it asks the ANACalc server to make physics data. When the ANACalc server receives a request, it delegates calculation programs to convert the acquired data into physics data. Because the interfaces between the server and the calculation processes are independent of programming languages and operating systems, the calculation processes can be placed on different computers and the server load can be reduced. Therefore, the system can respond to changes in requirements by replacing the calculation programs, and can easily be expanded by increasing the number of calculation servers

  10. Role Based Access Control system in the ATLAS experiment

    Valsan, M L; The ATLAS collaboration; Lehmann Miotto, G; Scannicchio, D A; Schlenker, S; Filimonov, V; Khomoutnikov, V; Dumitru, I; Zaytsev, A S; Korol, A A; Bogdantchikov, A; Caramarcu, C; Ballestrero, S; Darlea, G L; Twomey, M; Bujor, F; Avolio, G

    2011-01-01

    The complexity of the ATLAS experiment motivated the deployment of an integrated Access Control System in order to guarantee safe and optimal access for a large number of users to the various software and hardware resources. Such an integrated system was foreseen since the design of the infrastructure and is now central to the operations model. In order to cope with the ever growing needs of restricting access to all resources used within the experiment, the Roles Based Access Control (RBAC) previously developed has been extended and improved. The paper starts with a short presentation of the RBAC design, implementation and the changes made to the system to allow the management and usage of roles to control access to the vast and diverse set of resources. The paper continues with a detailed description of the integration across all areas of the system: local Linux and Windows nodes in the ATLAS Control Network (ATCN), the Linux application gateways offering remote access inside ATCN, the Windows Terminal Serv...

  11. Role Based Access Control System in the ATLAS Experiment

    Valsan, M L; The ATLAS collaboration; Lehmann Miotto, G; Scannicchio, D A; Schlenker, S; Filimonov, V; Khomoutnikov, V; Dumitru, I; Zaytsev, A S; Korol, A A; Bogdantchikov, A; Avolio, G; Caramarcu, C; Ballestrero, S; Darlea, G L; Twomey, M; Bujor, F

    2010-01-01

    The complexity of the ATLAS experiment motivated the deployment of an integrated Access Control System in order to guarantee safe and optimal access for a large number of users to the various software and hardware resources. Such an integrated system was foreseen since the design of the infrastructure and is now central to the operations model. In order to cope with the ever growing needs of restricting access to all resources used within the experiment, the Roles Based Access Control (RBAC) previously developed has been extended and improved. The paper starts with a short presentation of the RBAC design, implementation and the changes made to the system to allow the management and usage of roles to control access to the vast and diverse set of resources. The paper continues with a detailed description of the integration across all areas of the system: local Linux and Windows nodes in the ATLAS Control Network (ATCN), the Linux application gateways offering remote access inside ATCN, the Windows Terminal Serv...

  12. DCSK Multi-Access Scheme for UHF RFID System

    Keqiang Yue

    2014-04-01

    Full Text Available DCSK modulation in chaos communication is a robust non-coherent modulation scheme. In this paper, the multiple-access DCSK scheme based on the OVSF code is proposed. Using the multiple-access DCSK scheme in RFID system, a DCSK-RFID system is presented. In the presented DCSK-RFID system, we use the DCSK for tag modulation for its low complexity and the simple receiver of the DCSK scheme is applied in reader part. The tag’s BER performance of the proposed DCSK-RFID system is carefully generalized both in theoretic analysis and in simulations. From the simulation results, the theoretical and simulation values match closely with each other. Then, we design an anti-collision MAC protocol based on multi-access DCSK-RFID scheme. We theoretically analyze the throughout in given number of tags. The simulation shows that the proposed algorithm has better throughout than S-Aloha system

  13. The Romanian Banking System after EU Accession

    Viorica IOAN

    2011-11-01

    Full Text Available Banks play an important role in the financial sector, in the proper functioning of economic entities and in the economy as a whole, therefore over time the establishment of a functioning banking system capable of delivering a wide range of products and services to meet the requirements of all potential customers has been a permanent concern. Considering the economic and financial reality, both internationally and domestically, each country and therefore, Romania is interested in creating a solid banking system, enabling the appropriate organizational framework in order to ensure a development of the financial mechanisms. The banking system as the basic element of the financial system, allows an efficient allocation of resources in the economy and, in order to function properly, we need to know the risks they face:a slow economic growth may cause losses due to difficulties in repaying bank loans, due to lower sales or lower wages, changes in asset prices may cause financial losses to investors, decreasing a sector of the economy which has monopolized the banks’ and investors’ attention.

  14. Efficient medium access control protocol for geostationary satellite systems

    王丽娜; 顾学迈

    2004-01-01

    This paper proposes an efficient medium access control (MAC) protocol based on multifrequency-time division multiple access (MF-TDMA) for geostationary satellite systems deploying multiple spot-beams and onboard processing,which uses a method of random reservation access with movable boundaries to dynamically request the transmission slots and can transmit different types of traffic. The simulation results have shown that our designed MAC protocol can achieve a high bandwidth utilization, while providing the required quality of service (QoS) for each class of service.

  15. A new access control system by fingerprint for radioisotope facilities

    Kawamura, Hiroko; Hirata, Yasuki [Kyushu Univ., Fukuoka (Japan). Radioisotope Center; Kondo, Takahiro; Takatsuki, Katsuhiro

    1998-04-01

    We applied a new fingerprint checker for complete access control to the radiation controlled area and to the radioisotope storage room, and prepared softwares for the best use of this checker. This system consists of a personal computer, access controllers, a fingerprint register, fingerprint checkers, a tenkey and mat sensors, permits ten thousand users to register their fingerprints and its hard disk to keep more than a million records of user`s access. Only 1% of users could not register their fingerprints worn-out, registered four numbers for a fingerprint. The softwares automatically provide varieties of reports, caused a large reduction in manual works. (author)

  16. An optically coupled system for quantitative monitoring of MRI gradient currents induced into endocardial leads.

    Mattei, E; Calcagnini, G; Triventi, M; Delogu, A; Del Guercio, M; Angeloni, A; Bartolini, P

    2013-01-01

    The time-varying gradient fields generated during Magnetic Resonance Imaging (MRI) procedures have the potential to induce electrical current on implanted endocardial leads. Whether this current can result in undesired cardiac stimulation is unknown. This paper presents an optically coupled system with the potential to quantitatively measure the currents induced by the gradient fields into endocardial leads during MRI procedures. Our system is based on a microcontroller that works as analog-to-digital (A/D) converter and sends the current signal acquired from the lead to an optical high-speed light-emitting-diode transmitter. Plastic fiber guides the light outside the MRI chamber, to a photodiode receiver and then to an acquisition board connected to a PC. The preliminary characterization of the performances of the system is also presented. PMID:24110209

  17. Technical performance evaluation of a human brain PET/MRI system

    Kolb, Armin; Wehrl, Hans F.; Judenhofer, Martin S.; Pichler, Bernd J. [Eberhard Karls University, Department of Preclinical Imaging and Radiopharmacy, Tuebingen (Germany); Hofmann, Matthias [Eberhard Karls University, Department of Preclinical Imaging and Radiopharmacy, Tuebingen (Germany); Max Planck Institute for Biological Cybernetics, Tuebingen (Germany); Eriksson, Lars; Ladebeck, Ralf; Byars, Larry; Michel, Christian; Schmand, Matthias [Siemens Healthcare, Knoxville, TN (United States); Lichy, Matthias P. [Eberhard Karls University, Department of Diagnostic and Interventional Radiology, Department of Radiology, Tuebingen (Germany); Siemens Healthcare, Erlangen (Germany); Schlemmer, Heinz-Peter; Claussen, Claus D. [Eberhard Karls University, Department of Diagnostic and Interventional Radiology, Department of Radiology, Tuebingen (Germany); Sossi, Vesna [University of British Columbia, Vancouver (Canada)

    2012-08-15

    Technical performance evaluation of a human brain PET/MRI system. The magnetic field compatible positron emission tomography (PET) insert is based on avalanche photodiode (APD) arrays coupled with lutetium oxyorthosilicate (LSO) crystals and slip-fits into a slightly modified clinical 3-T MRI system. The mutual interference between the two imaging techniques was minimised by the careful design of the hardware to maintain the quality of the B{sub 0} and B{sub 1} field homogeneity. The signal-to-noise ratio (SNR) and the homogeneity of the MR images were minimally influenced by the presence of the PET. Measurements according to the Function Biomedical Informatics Research Network (FBIRN) protocol proved the combined system's ability to perform functional MRI (fMRI). The performance of the PET insert was evaluated according to the National Electrical Manufacturers Association (NEMA) standard. The noise equivalent count rate (NEC) peaked at 30.7 x 10{sup 3} counts/s at 7.3 kBq/mL. The point source sensitivity was greater than 7 %. The spatial resolution in the centre field of view was less than 3 mm. Patient data sets clearly revealed a noticeably good PET and MR image quality. PET and MRI phantom tests and first patient data exhibit the device's potential for simultaneous multiparametric imaging. (orig.)

  18. A head-mounted display system for augmented reality: Initial evaluation for interventional MRI

    Purpose: To discuss the technical details of a head mounted display with an augmented reality (AR) system and to describe a first pre-clinical evaluation in interventional MRI. Method: The AR system consists of a video-see-through head mounted display (HMD), mounted with a mini video camera for tracking and a stereo pair of mini cameras that capture live images of the scene. The live video view of the phantom/patient is augmented with graphical representations of anatomical structures from MRI image data and is displayed on the HMD. The application of the AR system with interventional MRI was tested using a MRI data set of the head and a head phantom. Results: The HMD enables the user to move around and observe the scene dynamically from various viewpoints. Within a short time the natural hand-eye coordination can easily be adapted to the slightly different view. The 3D perception is based on stereo and kinetic depth cues. A circular target with a diameter of 0.5 square centimeter was hit in 19 of 20 attempts. In a first evaluation the MRI image data augmented reality scene of a head phantom allowed good planning and precise simulation of a puncture. Conclusion: The HMD in combination with AR provides a direct, intuitive guidance for interventional MR procedures. (orig.)

  19. Remotely Accessed Vehicle Traffic Management System

    Al-Alawi, Raida

    2010-06-01

    The ever increasing number of vehicles in most metropolitan cities around the world and the limitation in altering the transportation infrastructure, led to serious traffic congestion and an increase in the travelling time. In this work we exploit the emergence of novel technologies such as the internet, to design an intelligent Traffic Management System (TMS) that can remotely monitor and control a network of traffic light controllers located at different sites. The system is based on utilizing Embedded Web Servers (EWS) technology to design a web-based TMS. The EWS located at each intersection uses IP technology for communicating remotely with a Central Traffic Management Unit (CTMU) located at the traffic department authority. Friendly GUI software installed at the CTMU will be able to monitor the sequence of operation of the traffic lights and the presence of traffic at each intersection as well as remotely controlling the operation of the signals. The system has been validated by constructing a prototype that resembles the real application.

  20. Abnormal findings of magnetic resonance imaging (MRI) in patients with systemic lupus erythematosus involving the brain

    Ishikawa, Akira; Okada, Jun; Kondo, Hirobumi (Kitasato Univ., Sagamihara, Kanagawa (Japan). School of Medicine); Kashiwazaki, Sadao

    1992-06-01

    To elucidate the clinical significance of MRI on central nervous system systemic lupus erythematosus (CNS-SLE), MRI and CT scans were performed in 35 patients with SLE, of 18 patients who had CNS manifestations at the time of MRI examinations. The investigations were also carried out in 17 patients without CNS-SLE. The rate of detection of abnormal findings on MRI in patients with CNS-SLE was 77.2% (14/18), which was high, as compared with the rate of those on CT scans (50%: 9/18). Especially, all of 4 patients with seizure and 3 patients with encephalopathy showed abnormal MRI findings, although respectively 50% and 33.3% of them had abnormal CT scan findings. MRI findings were classified into 4 groups below: (1) Large focal are as increased signal intensity at T2 weighted image. These were observed in 2 of 4 patients with seizure and 1 of 3 patients with encephalopathy, which were completely resolved after treatment. (2) Patchy subcortical foci of increased signal intensity at T2 weighted image. These were observed in 11 of 18 CNS-SLE and 7 of 17 without CNS-SLE, which were not detected by CT scan. (3) All of six patients with cerebral infarctions showed high signal intensity areas at T2 weighted image and low signal intensity areas at T1 weighted image. (4) Normal findings were observed in 4 of 18 CNS-SLE (22.2%). We concluded that MRI is useful for the evaluation of CNS-SLE and provides more information than CT scan. (author).

  1. SPS access control system a new user interface

    Riesco, T

    1999-01-01

    This document describes the project to implement at CERN new trends in industrial control systems and integrate new requirements and functions requested by users. This project will be the testing ground for the specification of procedures in the Access Control and Machine Interlock of LHC. The last modification in the Access Control System to the primary beam areas was made in 1995, and this new project is to improve the fields of personal security, access security and the introduction of modern communication networks used in the industrial control systems. Inside the cycle model of project life, it is at the present time in the test phase in terms of security and exploitation inside the Accelerator Decelerator (AD) project. The presence of Authorization Management System (AMS) to guarantee the automatic information distribution of authorizations to controlled areas is in line with this project.

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

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

    2014-03-01

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

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

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

  4. MRI findings in Tolosa-Hunt syndrome before and after systemic corticosteroid therapy

    Tolosa-Hunt syndrome (THS) is characterized by painful ophthalmoplegia due to a granulomatous inflammation in the cavernous sinus. Corticosteroid therapy dramatically resolves both the clinical and radiological findings of THS. We present MRI findings of six patients with a clinical history of at least one episode of unilateral or bilateral orbital-periorbital pain, clinical findings of associated paresis of one or more of 3rd, 4th, 5th or 6th cranial nerves. All of the patients revealed an enlargement of the symptomatic cavernous sinus on magnetic resonance imaging (MRI) scans. Five patients revealed total resolution of the clinical findings within 1-8 weeks, following systemic corticosteroid treatment. One patient revealed only minor regression of clinical findings within 2 weeks after the initiation of the treatment, so the cavernous sinus lesion was reevaluated as meningioma on MRI, and the patient underwent surgical resection of the mass with resultant histopathological finding of cavernous sinus meningioma. A follow-up MRI scan was performed for five patients at the end of 8-weeks of steroid therapy. Three of these five patients showed total resolution of the cavernous sinus lesions whereas two of them revealed a partial regression of the cavernous sinus lesions. MRI findings before and after systemic corticosteroid therapy are important diagnostic criteria to put the definitive diagnosis of THS and to differentiate it from other cavernous sinus lesions that simulate THS both clinically and radiologically

  5. MRI findings in Tolosa-Hunt syndrome before and after systemic corticosteroid therapy

    Cakirer, Sinan E-mail: scakirer@yahoo.com

    2003-02-01

    Tolosa-Hunt syndrome (THS) is characterized by painful ophthalmoplegia due to a granulomatous inflammation in the cavernous sinus. Corticosteroid therapy dramatically resolves both the clinical and radiological findings of THS. We present MRI findings of six patients with a clinical history of at least one episode of unilateral or bilateral orbital-periorbital pain, clinical findings of associated paresis of one or more of 3rd, 4th, 5th or 6th cranial nerves. All of the patients revealed an enlargement of the symptomatic cavernous sinus on magnetic resonance imaging (MRI) scans. Five patients revealed total resolution of the clinical findings within 1-8 weeks, following systemic corticosteroid treatment. One patient revealed only minor regression of clinical findings within 2 weeks after the initiation of the treatment, so the cavernous sinus lesion was reevaluated as meningioma on MRI, and the patient underwent surgical resection of the mass with resultant histopathological finding of cavernous sinus meningioma. A follow-up MRI scan was performed for five patients at the end of 8-weeks of steroid therapy. Three of these five patients showed total resolution of the cavernous sinus lesions whereas two of them revealed a partial regression of the cavernous sinus lesions. MRI findings before and after systemic corticosteroid therapy are important diagnostic criteria to put the definitive diagnosis of THS and to differentiate it from other cavernous sinus lesions that simulate THS both clinically and radiologically.

  6. Application Of Fuzzy System In Segmentation Of MRI Brain Tumor

    Rajya, Mrigank; Sheoran, Swati

    2010-01-01

    Segmentation of images holds an important position in the area of image processing. It becomes more important whi le typically dealing with medical images where presurgery and post surgery decisions are required for the purpose of initiating and speeding up the recovery process. Segmentation of 3-D tumor structures from magnetic resonance images (MRI) is a very challenging problem due to the variability of tumor geometry and intensity patterns. Level set evolution combining global smoothness with the flexibility of topology changes offers significant advantages over the conventional statistical classification followed by mathematical morphology. Level set evolution with constant propagation needs to be initialized either completely inside or outside the tumor and can leak through weak or missing boundary parts. Replacing the constant propagation term by a statistical force overcomes these limitations and results in a convergence to a stable solution. Using MR images presenting tumors, probabilities for backgr...

  7. Development of a flexible optical fiber based high resolution integrated PET/MRI system

    Yamamoto, Seiichi; Watabe, Hiroshi; Kanai, Yasukazu; Watabe, Tadashi; Aoki, Masaaki; Sugiyama, Eiji; Kato, Katsuhiko; Hatazawa, Jun [Department of Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine, Nagoya, Aichi 461-8673 (Japan); Department of Molecular Imaging in Medicine, Osaka University Graduate School of Medicine, Osaka 565-0871 (Japan); Department of Nuclear Medicine and Tracer Kinetics, Osaka University Graduate School of Medicine, 565-0871 Osaka (Japan); Neomax Engineering, Takasaki 370-2115 (Japan); Department of Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine, Nagoya 461-8673 (Japan); Department of Nuclear Medicine and Tracer Kinetics, Osaka University Graduate School of Medicine, Osaka 565-0871 (Japan) and Department of Molecular Imaging in Medicine, Osaka University Graduate School of Medicine, Osaka 565-0871 (Japan)

    2012-11-15

    Purpose: The simultaneous measurement of PET and magnetic resonance imaging (MRI) is an emerging field for molecular imaging research. Although optical fiber based PET/MRI systems have advantages on less interference between PET and MRI, there is a drawback in reducing the scintillation light due to the fiber. To reduce the problem, the authors newly developed flexible optical fiber bundle based block detectors and employed them for a high resolution integrated PET/MRI system. Methods: The flexible optical fiber bundle used 0.5 mm diameter, 80 cm long double clad fibers which have dual 12 mm Multiplication-Sign 24 mm rectangular inputs and a single 24 mm Multiplication-Sign 24 mm rectangular output. In the input surface, LGSO scintillators of 0.025 mol.% (decay time: {approx}31 ns: 0.9 mm Multiplication-Sign 1.3 mm Multiplication-Sign 5 mm) and 0.75 mol.% (decay time: {approx}46 ns: 0.9 mm Multiplication-Sign 1.3 mm Multiplication-Sign 6 mm) were optically coupled in depth direction to form depth-of-interaction detector, arranged in 11 Multiplication-Sign 13 matrix and optically coupled to the fiber bundle. The two inputs of the bundle are bent for 90 Degree-Sign , bound to one, and are optically coupled to a Hamamatsu 1-in. square position sensitive photomultiplier tube. Results: Light loss due to the fiber bundle could be reduced and the performance of the block detectors was improved. Eight optical fiber based block detectors (16 LGSO blocks) were arranged in a 56 mm diameter ring to form a PET system. Spatial resolution and sensitivity were 1.2 mm full-width at half-maximum and 1.2% at the central field-of-view, respectively. Sensitivity change was less than 1% for 2 Degree-Sign C temperature changes. This PET system was integrated with a 0.3 T permanent magnet MRI system which has 17 cm diameter hole at the yoke area for insertion of the PET detector ring. There was no observable interference between PET and MRI. Simultaneous imaging of PET and MRI was

  8. Access Safety Systems – New Concepts from the LHC Experience

    Ladzinski, T; di Luca, S; Hakulinen, T; Hammouti, L; Riesco, T; Nunes, R; Ninin, P; Juget, J-F; Havart, F; Valentini, F; Sanchez-Corral Mena, E

    2011-01-01

    The LHC Access Safety System has introduced a number of new concepts into the domain of personnel protection at CERN. These can be grouped into several categories: organisational, architectural and concerning the end-user experience. By anchoring the project on the solid foundations of the IEC 61508/61511 methodology, the CERN team and its contractors managed to design, develop, test and commission on time a SIL3 safety system. The system uses a successful combination of the latest Siemens redundant safety programmable logic controllers with a traditional relay logic hardwired loop. The external envelope barriers used in the LHC include personnel and material access devices, which are interlocked door-booths introducing increased automation of individual access control, thus removing the strain from the operators. These devices ensure the inviolability of the controlled zones by users not holding the required credentials. To this end they are equipped with personnel presence detectors and th...

  9. The OMERACT psoriatic arthritis magnetic resonance imaging scoring system (PsAMRIS): definitions of key pathologies, suggested MRI sequences, and preliminary scoring system for PsA Hands

    Østergaard, Mikkel; McQueen, Fiona; Wiell, Charlotte;

    2009-01-01

    This article describes a preliminary OMERACT psoriatic arthritis magnetic resonance image scoring system (PsAMRIS) for evaluation of inflammatory and destructive changes in PsA hands, which was developed by the international OMERACT MRI in inflammatory arthritis group. MRI definitions of importan...... pathologies in peripheral PsA and suggestions concerning appropriate MRI sequences for use in PsA hands are also provided.......This article describes a preliminary OMERACT psoriatic arthritis magnetic resonance image scoring system (PsAMRIS) for evaluation of inflammatory and destructive changes in PsA hands, which was developed by the international OMERACT MRI in inflammatory arthritis group. MRI definitions of important...

  10. Value of MRI of the brain in patients with systemic lupus erythematosus and neurologic disturbance

    Our objective was to review the frequency and pattern of signal abnormalities seen on conventional MRI in patients with suspected neuropsychiatric systemic lupus erythematosus (NP-SLE). We reviewed 116 MRI examinations of the brain performed on 85 patients with SLE, (81 women, four men, aged 21-78 years, mean 40.6 years) presenting with neurological disturbances. MRI was normal or nearly normal in 34%. In 60% high-signal lesions were observed on T2-weighted images, frequently in the frontal and parietal subcortical white matter. Infarct-like lesions involving gray and white matter were demonstrated in 21 of cases. Areas of restricted diffusion were seen in 12 of the 67 patients who underwent diffusion-weighted imaging. Other abnormalities included loss of brain volume, hemorrhage, meningeal enhancement, and bilateral high signal in occipital white-matter. The MRI findings alone did not allow us to distinguish between thromboembolic and inflammatory events in many patients. Some patients with normal MRI improved clinically while on immunosuppressive therapy. More sensitive and/or specific imaging methods, such as spectroscopy and perfusion-weighted imaging, should be investigated in these subgroups of patients with suspected NP-SLE. (orig.)

  11. Portable MRI

    This project proposes to: (1) provide the power of MRI to situations where it presently isn't available; (2) perform the engineering required to move from lab to a functional prototype; and (3) leverage significant existing infrastructure and capability in ultra-low field MRI. The reasons for doing this: (1) MRI is the most powerful tool for imaging soft-tissue (e.g. brain); (2) Billions don't have access due to cost or safety issues; (3) metal will heat/move in high magnetic fields; (4) Millions of cases of traumatic brain injury in US alone; (5) even more of non-traumatic brain injury; (6) (e.g. stroke, infection, chemical exposure); (7) Need for early diagnostic; (8) 'Signature' wound of recent conflicts; (9) 22% of injuries; (10) Implications for post-traumatic stress disorder; and (11) chronic traumatic encephalopathy.

  12. Portable MRI

    Espy, Michelle A. [Los Alamos National Laboratory

    2012-06-29

    This project proposes to: (1) provide the power of MRI to situations where it presently isn't available; (2) perform the engineering required to move from lab to a functional prototype; and (3) leverage significant existing infrastructure and capability in ultra-low field MRI. The reasons for doing this: (1) MRI is the most powerful tool for imaging soft-tissue (e.g. brain); (2) Billions don't have access due to cost or safety issues; (3) metal will heat/move in high magnetic fields; (4) Millions of cases of traumatic brain injury in US alone; (5) even more of non-traumatic brain injury; (6) (e.g. stroke, infection, chemical exposure); (7) Need for early diagnostic; (8) 'Signature' wound of recent conflicts; (9) 22% of injuries; (10) Implications for post-traumatic stress disorder; and (11) chronic traumatic encephalopathy.

  13. Improving information access with an emergency department system.

    Travers, D.; Parham, T.

    1997-01-01

    An emergency department (ED) clinical system was developed by in-house personnel, with ED physician, nursing, registration and clerical staff input. The utilization of existing hardware and customization of the hospital's mainframe hospital information system (HIS) facilitated the implementation of a cost-effective system that meets the information access needs of a busy, state-of-the-art academic ED. The transition to automation of the ED was facilitated through the use of a comprehensive tr...

  14. Concurrent TMS-fMRI Reveals Interactions between Dorsal and Ventral Attentional Systems

    Leitao, Joana; Thielscher, Axel; Tuennerhoff, Johannes;

    2015-01-01

    interactively in this process. This fMRI study used concurrent transcranial magnetic stimulation (TMS) as a causal perturbation approach to investigate the interactions between dorsal and ventral attentional systems and sensory processing areas. In a sustained spatial attention paradigm, human participants...

  15. Advances of blood oxygen-level dependent MRI in muscular system

    BOLD-fMRI has been applied to muscular system to observe muscular pathophysiological change after performing a task and show the characteristics of muscle perfusion. This paper mainly introduces the scanning sequence, common tasking methods, such as cuff compression, excise, oxygen and drug, etc. It also introduces clinical study of perfusion reserve of muscular tissue with abnormal blood vessels. (authors)

  16. Magnetic field homogeneity of birdcage coil for 4T MRI system with no lumped circuit elements

    In recent years, magnetic resonance imaging (MRI) systems that operate up to under 3T are being used in clinical practice in Japan. In order to achieve the requirements of higher image quality and shorter imaging times, devices that utilize high magnetic fields (> 3T) and high power electromagnetic (EM) wave pulses have been developed. The rise of the static magnetic field is proportional to the increase of the EM wave frequency which raises the issue of variation in capacitance used in the radio frequency (RF) coil for MRI system. In addition, increasing power causes problems of withstanding voltage and these approaches leads to generation of non-uniform magnetic field inside the RF coil. Therefore, we proposed a birdcage coil without the use of lumped circuit elements for MRI systems in previous study. However, it is difficult to fabricate this birdcage coil. Hence, simply-structured birdcage coil with no lumped circuit elements is desired. In this paper, we propose a simply-structured birdcage coil with no lumped circuit elements for a 4T MRI system. In addition, the authors investigated the input impedance and magnetic field distribution of the proposed coil by FDTD calculations and measurements. The results confirm that the proposed birdcage coil matches the performance of the conventional birdcage coil which includes several capacitors. (author)

  17. Assessment of three different software systems in the evaluation of dynamic MRI of the breast

    Objective: The aim was to compare the diagnostic performance and handling of dynamic contrast-enhanced MRI of the breast with two commercial software solutions ('CADstream' and '3TP') and one self-developed software system ('Mammatool'). Materials and methods: Identical data sets of dynamic breast MRI from 21 patients were evaluated retrospectively with all three software systems. The exams were classified according to the BI-RADS classification. The number of lesions in the parametric mapping was compared to histology or follow-up of more than 2 years. In addition, 25 quality criteria were judged by 3 independent investigators with a score from 0 to 5. Statistical analysis was performed to document the quality ranking of the different software systems. Results: There were 9 invasive carcinomas, one pure DCIS, one papilloma, one radial scar, three histologically proven changes due to mastopathy, one adenosis and two fibroadenomas. Additionally two patients with enhancing parenchyma followed with MRI for more than 3 years and one scar after breast conserving therapy were included. All malignant lesions were classified as BI-RADS 4 or 5 using all software systems and showed significant enhancement in the parametric mapping. 'CADstream' showed the best score on subjective quality criteria. '3TP' showed the lowest number of false-positive results. 'Mammatool' produced the lowest number of benign tissues indicated with parametric overlay. Conclusion: All three software programs tested were adequate for sensitive and efficient assessment of dynamic MRI of the breast. Improvements in specificity may be achievable

  18. Accessibility and Radioactivity Calculations for Nuclear Reactor Shutdown System

    An important consideration in the design of power reactors is providing access to the reactor cooling system for the purposes of maintenance, repair and refuelling. The major sources of radiation which tend to prohibit such access are: induced activity of the reactor coolant, activated impurities in the reactor coolant and radiation originating in the reactor core both during reactor operation and after shut down. Impurities in the reactor coolant may be present in high enough concentrations so that their activation restricts accessibility for maintenance after shutdown. When water being used as a coolant, the activity of the water itself is very short- lived but their corrosive nature, resultant high impurity and induced activity of structural material are the major source of activity in the system after reactor shutdown. In this case, it may be necessary to chemically remove some of the impurity by a purification process to prevent a build up of long-lived induced activity in the system from restricting access to the plant, and to keep the radiation dose at the working places within the permissible limits. A mathematical modelling is developed. A system of coupled first-order linear differential equations describing adequately the activity behaviour has to be derived and solved. It treats the determination of equilibrium concentrations of impurities on system surface , and the effect of release of fission products from the reactor core

  19. Studies of the interactions of an MRI system with the shielding in a combined PET/MRI scanner

    A positron emission tomography (PET) system or 'insert' has been constructed for placement and operation in the bore of a small animal magnetic resonance imaging (MRI) scanner to allow simultaneous MR and PET imaging. The insert contains electronics, components with a variety of magnetic properties and large continuous sheets of metal-all characteristics of an object that should, by conventional wisdom, never be placed in the bore of an MR scanner, especially near the imaging volume. There are a variety of ways the two systems might be expected to interact that could negatively impact the performance of either or both. In this article, the interaction mechanisms, particularly the impact of the PET insert and shielding on MR imaging, are defined and explored. Additionally, some of the difficulties in quantifying errors introduced into the MR images as a result of the presence of the PET components are demonstrated. Several different approaches are used to characterize image artifacts and determine optimal placement of the shielding. Data are also presented that suggest ways the shielding could be modified to reduce errors and enable placement closer to the isocenter of the magnet.

  20. A novel IPTV program multiplex access system to EPON

    Xu, Xian; Liu, Deming; He, Wei; Lu, Xi

    2007-11-01

    With the rapid development of high speed networks, such as Ethernet Passive Optical Network (EPON), traffic patterns in access networks have evolved from traditional text-oriented service to the mixed text-, voice- and video- based services, leading to so called "Triple Play". For supporting IPTV service in EPON access network infrastructure, in this article we propose a novel IPTV program multiplex access system to EPON, which enables multiple IPTV program source servers to seamlessly access to IPTV service access port of optical line terminal (OLT) in EPON. There are two multiplex schemes, namely static multiplex scheme and dynamic multiplex scheme, in implementing the program multiplexing. Static multiplex scheme is to multiplex all the IPTV programs and forward them to the OLT, regardless of the need of end-users. While dynamic multiplex scheme can dynamically multiplex and forward IPTV programs according to what the end-users actually demand and those watched by no end-user would not be multiplexed. By comparing these two schemes, a reduced traffic of EPON can be achieved by using dynamic multiplex scheme, especially when most end-users are watching the same few IPTV programs. Both schemes are implemented in our system, with their hardware and software designs described.

  1. THE USAGE OF HRU SEGMENT MATRIX ACCESS IN THE ANALYSIS OF INFORMATION SECURITY SYSTEMS WHICH MAKE MANDATORY ACCESS CONTROL

    Korolev I. D.

    2014-09-01

    Full Text Available In this article we consider the usage of HRU access matrix changing system allowing for information security system which makes mandatory access control in case of information security analysis by using an automatic classification of formalized documents in the system of electronic document management

  2. The unified management of access authorization for information systems

    This paper describes the requirements of the unified management of access authorization for different information systems, from the point of view of the unified management to all applications of the enterprise. This paper also gives the design of software based on the requirements. (authors)

  3. The ARAC client system: network-based access to ARAC

    The ARAC Client System allows users (such as emergency managers and first responders) with commonly available desktop and laptop computers to utilize the central ARAC system over the Internet or any other communications link using Internet protocols. Providing cost-effective fast access to the central ARAC system greatly expands the availability of the ARAC capability. The ARAC Client system consists of (1) local client applications running on the remote user's computer, and (2) ''site servers'' that provide secure access to selected central ARAC system capabilities and run on a scalable number of dedicated workstations residing at the central facility. The remote client applications allow users to describe a real or potential them-bio event, electronically sends this information to the central ARAC system which performs model calculations, and quickly receive and visualize the resulting graphical products. The site servers will support simultaneous access to ARAC capabilities by multiple users. The ARAC Client system is based on object-oriented client/server and distributed computing technologies using CORBA and Java, and consists of a large number of interacting components

  4. Pre-surgery localization of non-palpable lesions of the breast using a 1.0 Tesla MRI system and a body coil

    The purpose of the study was to verify whether examination with a non-dedicated MRI body coil, i.e. without complementing electronic hardware, will reliably locate the lesion revealed by the MR-mammography. The idea was that if the results obtained were equal in value, a less expensive alternative for tumor localization might have been found. Material and methods: In 18 patients we performed a contrast enhanced (i.v. 0.2 mmol Gd-DTPA/kg b.w.) breast MRI on a 1.0 Tesla system (Magnetom Impact, Siemens, Erlangen, Germany) using a body coil and a GRE 3D sequence. In prone position, the patients were placed in a customized positioning device offering lateral access to the breast. The localizations were done with a MRI-compatible wire (n=21). In addition, all patients underwent the same imaging protocol using a dedicated breast coil (without localization). For both MRI modalities, the signal intensities of the lesion, the normal breast tissue, and the background noise were measured. The lesion-to-fat contrast (LFC), the lesion-to-breast tissue contrast (LCB) and the percentage of signal change pre- and post-contrast administration were calculated and compared. The localization results were correlated to pathologic findings. Results: There was no difference in lesion detection. Regarding the LCF and LBC, the body coil was superior to the dedicated breast coil. However, the background noise was higher using the body coil. In all cases the localization was successful. (orig./CB)

  5. Does the public deserve free access to climate system science?

    Grigorov, Ivo

    2010-05-01

    Some time ago it was the lack of public access to medical research data that really stirred the issue and gave inertia for legislation and a new publishing model that puts tax payer-funded medical research in the hands of those who fund it. In today's age global climate change has become the biggest socio-economic challenge, and the same argument resonates: climate affects us all and the publicly-funded science quantifying it should be freely accessible to all stakeholders beyond academic research. Over the last few years the ‘Open Access' movement to remove as much as possible subscription, and other on-campus barriers to academic research has rapidly gathered pace, but despite significant progress, the climate system sciences are not among the leaders in providing full access to their publications and data. Beyond the ethical argument, there are proven and tangible benefits for the next generation of climate researchers to adapt the way their output is published. Through the means provided by ‘open access', both data and ideas can gain more visibility, use and citations for the authors, but also result in a more rapid exchange of knowledge and ideas, and ultimately progress towards a sought solution. The presentation will aim to stimulate discussion and seek progress on the following questions: Should free access to climate research (& data) be mandatory? What are the career benefits of using ‘open access' for young scientists? What means and methods should, or could, be incorporated into current European graduate training programmes in climate research, and possible ways forward?

  6. Implementation of a ferromagnetic detection system in a clinical MRI setting

    Purpose: To evaluate the implementation of a ferromagnetic detection system (FMDS) into a clinical MRI setting. Materials and methods: One thousand patients were considered for MRI safety screening using an FMDS. Equipment used was a Ferroguard® Screener (Metrasens Ltd, Malvern, Worcestershire, UK). Fully gowned patients rotated 360° in front of the FMDS in a standardized manner following traditional MRI screening methods (the use of a written questionnaire (Fig. B.1) and verbal interview. Results: Final results included 1032 individual screening events performed in 977 patients. There were 922 (94%) initial passes using the FMDS; 34 (4%) failed initial screens but passed a subsequent screen; 21 (2%) failed the initial and subsequent screens. Thus, including all screening events (n = 1032), there were 956 (93%) true negatives (TN); 21 (2%) false positives (FP) and 55 (5%) true positives (TP). No false negatives (FN) were recorded. Therefore, sensitivity was 100% and specificity was 98%. Conclusion: Implementation and correct usage of an FMDS proved to increase safety within a clinical MRI environment by alerting staff to ferromagnetic items or implants not identified using traditional MRI screening methods. An FMDS should be used as an adjunct to these methods. The information in this study pertains to the specific equipment used in this investigation. - Highlights: • Ferromagnetic detection system sensitivity in this study was 100%. • Ferromagnetic detection system specificity in this study was 98%. • The additional screening procedure had little impact on throughput ie additional time taken was minimal. • Staff training, technique and compliance is important in implementing the screening procedures. • The ferromagnetic detection system identified objects that may have demonstrated projectile, heating or artefact effects

  7. NASA Access Mechanism - Graphical user interface information retrieval system

    Hunter, Judy F.; Generous, Curtis; Duncan, Denise

    1993-01-01

    Access to online information sources of aerospace, scientific, and engineering data, a mission focus for NASA's Scientific and Technical Information Program, has always been limited by factors such as telecommunications, query language syntax, lack of standardization in the information, and the lack of adequate tools to assist in searching. Today, the NASA STI Program's NASA Access Mechanism (NAM) prototype offers a solution to these problems by providing the user with a set of tools that provide a graphical interface to remote, heterogeneous, and distributed information in a manner adaptable to both casual and expert users. Additionally, the NAM provides access to many Internet-based services such as Electronic Mail, the Wide Area Information Servers system, Peer Locating tools, and electronic bulletin boards.

  8. NASA access mechanism: Graphical user interface information retrieval system

    Hunter, Judy; Generous, Curtis; Duncan, Denise

    1993-01-01

    Access to online information sources of aerospace, scientific, and engineering data, a mission focus for NASA's Scientific and Technical Information Program, has always been limited to factors such as telecommunications, query language syntax, lack of standardization in the information, and the lack of adequate tools to assist in searching. Today, the NASA STI Program's NASA Access Mechanism (NAM) prototype offers a solution to these problems by providing the user with a set of tools that provide a graphical interface to remote, heterogeneous, and distributed information in a manner adaptable to both casual and expert users. Additionally, the NAM provides access to many Internet-based services such as Electronic Mail, the Wide Area Information Servers system, Peer Locating tools, and electronic bulletin boards.

  9. Preface to Evaluating Systems for Multilingual and Multimodal information Access

    Peters, Carol; Deselaers, Thomas; Ferro, Nicola; Gonzalo, Julio; Jones, Gareth J.F.; Kurimo, Mikko; Mandl, Thomas; Penas, Anselmo; Petras, Vivien

    2009-01-01

    This book constitutes the thoroughly refereed proceedings of the 9th Workshop of the Cross-Language Evaluation Forum, CLEF 2008, held in Aarhus, Denmark, in September 2008. The 130 revised and extended papers presented were carefully reviewed and selected for inclusion in the book. They are completed by an introduction on CLEF 2008. As usual, the seven main evaluation tracks in CLEF 2008 aimed to test the performance of a wide range of multilingual information access systems or system compone...

  10. Workflow management systems, their security and access control mechanisms

    Chehrazi, Golriz

    2007-01-01

    This paper gives an overview of workflow management systems (WfMSs) and their security requirements with focus on access mechanisms. It is a descriptive paper in which we examine the state of the art of workflow systems, describe what security risks affect WfMSs in particular, and how these can be diminiuished. WfMSs manage, illustrate and support business processes. They contribute to the performance, automation and optimization of processes, which is important in the global economy today. ...

  11. A United Access Control Model for Systems in Collaborative Commerce

    Ruo-Fei Han

    2009-06-01

    Full Text Available The latest researches on access control model are dramatically different from conventional ones. Nowadays, most attention is paid to accessing across organizational boundaries. So, how to identify the applicant and determine authorization with limited information; how to express and exchange control rules expediently; how to protect confidential information and enhance collaboration simultaneously, are the most concerned problems. However, for large commercial organizations, a fine management of internal functions is of the same importance as external service management. It is very troublesome to control authorizations merely with attributes and composition of policies introduced from attribute-based access control (ABAC. So, we introduce a united access control model for systems in collaborative commerce, combining the advantages of conventional role-based access control (RBAC, task-based authentication control (TBAC and that of recent ABAC and automated trust negotiation (ATN. Innovational ideas in the model are analyzed, and the implement architecture is discussed. The paper concludes with a summary of the united model’s benefits and future work.

  12. Philips 3T Intera Magnetic Resonance Imaging System and Upgrade of existing MRI equipment

    Evanochko, William T

    2004-05-14

    The objective of this proposal was twofold. First, upgrade existing MRI equipment, specifically a research 4.1T whole-body system. Second, purchase a clinical, state-of-the-art 3T MRI system tailored specifically to cardiovascular and neurological applications. This project was within the guidelines of ''Medical Applications and Measurement Science''. The goals were: [1] to develop beneficial applications of magnetic resonance imaging; [2] discover new applications of MR strategies for medical research; and [2] apply them for clinical diagnosis. Much of this proposal searched for breakthroughs in this noninvasive and nondestructive imaging technology. Finally, this proposal's activities focused on research in the basic science of chemistry, biochemistry, physics, and engineering as applied to bioengineering. The centerpiece of this grant was our 4.1T ultra-high field whole-body nuclear magnetic resonance system and the newly acquired state-of-the-art, heart and head dedicated 3T clinical MRI system. We have successfully upgraded the equipment for the 4.1T system so that it is now state-of-the-art with new gradient and radio frequency amplifiers. We also purchase a unique In Vivo EKG monitoring unit that will permit tracking clinical quality EKG signals while the patient is in a high field MR scanner. Important upgrades of a peripheral vascular coil and a state-of-the-art clinical workstation for processing complex heart images were implemented. The most recent acquisition was the purchase of a state-of-the-art Philips 3T Intera clinical MRI system. This system is unique in that the magnet is only 5 1/2 feet long compare to over 12 feet long magnet of our 4.1T MRI system. The 3T MRI system is fully functional and its use and applications are already greatly benefiting the UAB with 200-300 micron resolution brain images and diagnostic quality MR angiography of coronary arteries in less than 5 minutes.

  13. Visualization of suspicious lesions in breast MRI based on intelligent neural systems

    Twellmann, Thorsten; Lange, Oliver; Nattkemper, Tim Wilhelm; Meyer-Bäse, Anke

    2006-05-01

    Intelligent medical systems based on supervised and unsupervised artificial neural networks are applied to the automatic visualization and classification of suspicious lesions in breast MRI. These systems represent an important component of future sophisticated computer-aided diagnosis systems and enable the extraction of spatial and temporal features of dynamic MRI data stemming from patients with confirmed lesion diagnosis. By taking into account the heterogenity of the cancerous tissue, these techniques reveal the malignant, benign and normal kinetic signals and and provide a regional subclassification of pathological breast tissue. Intelligent medical systems are expected to have substantial implications in healthcare politics by contributing to the diagnosis of indeterminate breast lesions by non-invasive imaging.

  14. Visual MRI grading system to evaluate atrophy of the supeaspinatus muscle

    Lim, Hyun Kyoung; Hong, Sung Hwan; Yoo, Hye Jin; Choi, Ja Young; Kim, Sae Hoon; Choi, Jung Ah; Kang, Heung Sik [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2014-08-15

    To investigate the interobserver reproducibility and diagnostic feasibility of a visual grading system for assessing atrophy of the supraspinatus muscle on magnetic resonance imaging (MRI). Three independent radiologists retrospectively evaluated the occupying ratio of the supraspinatus muscle in the supraspinatus fossa on 192 shoulder MRI examinations in 188 patients using a 3-point visual grading system (1, ≥ 60%; 2, 30-59%; 3, < 30%) on oblique sagittal T1-weighted images. The inter-reader agreement and the agreement with the reference standard (3-point grades according to absolute occupying ratio values quantitatively measured by directly contouring the muscles on MRI) were analyzed using weighted kappa. The visual grading was applied by a single reader to a group of 100 consecutive patients who had undergone rotator cuff repair to retrospectively determine the association between the visual grades at preoperative state and postsurgical occurrences of retear. The inter-reader weighted kappa value for the visual grading was 0.74 when averaged across three reader pairs (0.70-0.77 for individual reader pairs). The weighted kappa value between the visual grading and the reference standard ranged from 0.75 to 0.83. There was a significant difference in retear rates of the rotator cuff between the 3 visual grades of supraspinatus muscle atrophy on MRI in univariable analysis (p < 0.001), but not in multivariable analysis (p = 0.026). The 3-point visual grading system may be a feasible method to assess the severity of supraspinatus muscle atrophy on MRI and assist in the clinical management of patients with rotator cuff tear.

  15. volBrain: An Online MRI Brain Volumetry System.

    Manjón, José V; Coupé, Pierrick

    2016-01-01

    The amount of medical image data produced in clinical and research settings is rapidly growing resulting in vast amount of data to analyze. Automatic and reliable quantitative analysis tools, including segmentation, allow to analyze brain development and to understand specific patterns of many neurological diseases. This field has recently experienced many advances with successful techniques based on non-linear warping and label fusion. In this work we present a novel and fully automatic pipeline for volumetric brain analysis based on multi-atlas label fusion technology that is able to provide accurate volumetric information at different levels of detail in a short time. This method is available through the volBrain online web interface (http://volbrain.upv.es), which is publically and freely accessible to the scientific community. Our new framework has been compared with current state-of-the-art methods showing very competitive results. PMID:27512372

  16. volBrain: An Online MRI Brain Volumetry System

    Manjón, José V.; Coupé, Pierrick

    2016-01-01

    The amount of medical image data produced in clinical and research settings is rapidly growing resulting in vast amount of data to analyze. Automatic and reliable quantitative analysis tools, including segmentation, allow to analyze brain development and to understand specific patterns of many neurological diseases. This field has recently experienced many advances with successful techniques based on non-linear warping and label fusion. In this work we present a novel and fully automatic pipeline for volumetric brain analysis based on multi-atlas label fusion technology that is able to provide accurate volumetric information at different levels of detail in a short time. This method is available through the volBrain online web interface (http://volbrain.upv.es), which is publically and freely accessible to the scientific community. Our new framework has been compared with current state-of-the-art methods showing very competitive results.

  17. Computer systems handle changing T-line access

    Paula, G.

    1990-03-01

    As the number of power exchanges among utilities grows and transmission lines are loaded more heavily, it becomes increasingly difficult to manage power-system access. A study sponsored by the Electric Power Research Institute (EPRI) identifies two analysis techniques that can provide more detailed line-use information to help utilities ensure continued reliability. After meeting internal needs, a utility agrees on usage price and terms with other power suppliers and users that want to transfer power across its lines. This is known as wheeling. However, such transactions affect the loading of lines belonging to other utilities. As a result, no utility can actually control who uses its transmission system. Many utilities would like a way to monitor power flows on their systems to improve the economy and reliability of operation. The EPRI-sponsored study, conducted by Casazza, Schultz, Associates (CSA), Arlington, VA, identifies ways that computer methods can help utilities cope with increased line access.

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

    Meng, Ling-Jian

    2012-12-27

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

  19. MRI-guided prostate focal laser ablation therapy using a mechatronic needle guidance system

    Cepek, Jeremy; Lindner, Uri; Ghai, Sangeet; Davidson, Sean R. H.; Trachtenberg, John; Fenster, Aaron

    2014-03-01

    Focal therapy of localized prostate cancer is receiving increased attention due to its potential for providing effective cancer control in select patients with minimal treatment-related side effects. Magnetic resonance imaging (MRI)-guided focal laser ablation (FLA) therapy is an attractive modality for such an approach. In FLA therapy, accurate placement of laser fibers is critical to ensuring that the full target volume is ablated. In practice, error in needle placement is invariably present due to pre- to intra-procedure image registration error, needle deflection, prostate motion, and variability in interventionalist skill. In addition, some of these sources of error are difficult to control, since the available workspace and patient positions are restricted within a clinical MRI bore. In an attempt to take full advantage of the utility of intraprocedure MRI, while minimizing error in needle placement, we developed an MRI-compatible mechatronic system for guiding needles to the prostate for FLA therapy. The system has been used to place interstitial catheters for MRI-guided FLA therapy in eight subjects in an ongoing Phase I/II clinical trial. Data from these cases has provided quantification of the level of uncertainty in needle placement error. To relate needle placement error to clinical outcome, we developed a model for predicting the probability of achieving complete focal target ablation for a family of parameterized treatment plans. Results from this work have enabled the specification of evidence-based selection criteria for the maximum target size that can be confidently ablated using this technique, and quantify the benefit that may be gained with improvements in needle placement accuracy.

  20. MRI of the spinocerebellar degeneration (multiple system atrophy, Holmes type, and Menzel-Joseph type)

    Mukai, Eiichiro (National Hospital of Nagoya (Japan)); Makino, Naoki

    1991-06-01

    We have analyzed MRI in 33 patients with several forms of spinocerebellar degeneration; 17 with multiple system atrophy, 10 with Holmes type, and 6 with Menzel-Joseph type. The MRIs were obtained using a 1.5-T GEMR System. Patients with multiple system atrophy demonstrated: atrophy of the brain stem, particularly basis pontis; decreased signal intensity of the white matter of pons; atrophy of the white matter of cerebellum; atrophy and decreased signal intensity of the putamen, particularly along their lateral and posterior portions; and atrophy of the cerebrum. Patients with Holmes type showed: atrophy of the cerebellum; atrophy of the vermis more than hemispheres; and nuclei of the cerebellum with no decreased intensity on T{sub 2}-weighted sequences. Patients with Menzel-Joseph type demonstrated moderate atrophy of the brain stem and mild atrophy of the white matter of cerebellum. MRI is a useful diagnostic tool in the management of the spinocerebellar degeneration. (author).

  1. Central nervous system lesions in adult T-cell leukaemia: MRI and pathology

    Kitajima, M.; Korogi, Y.; Shigematsu, Y.; Liang, L.; Takahashi, M. [Department of Radiology, Kumamoto University School of Medicine, Honjo, Kumamoto (Japan); Matsuoka, M. [Second Division of Internal Medicine, Kumamoto University School of Medicine, Honjo, Kumamoto (Japan); Yamamoto, T. [Department of Pathology, Kumamoto University School of Medicine, Honjo, Kumamoto (Japan); Jhono, M. [Department of Dermatology, Kumamoto University School of Medicine, Honjo, Kumamoto (Japan); Eto, K. [The National Institute for Minamata Disease, Minamata (Japan)

    2002-07-01

    Adult T-cell leukaemia (ATL) is a T-cell lymphoid neoplasm caused by human T-cell leukaemia virus type I (HTLV-I). Radiological findings in central nervous system (CNS) involvement have not been well characterised. We reviewed the MRI of 18 patients with ATL who developed new neurological symptoms or signs, and pathology specimens from a 53-year-old woman who died of ATL. MRI findings were divided into three categories: definite, probable, and other abnormal. Definite and probable findings were defined as ATL-related. The characteristic findings were multiple parenchymal masses with or without contrast enhancement adjacent to cerebrospinal fluid (CSF) spaced and the deep grey matter of both cerebral hemispheres, plus leptomeningeal lesion. One patient had both cerebral and spinal cord lesions. Other abnormal findings in eight patients included one case of leukoencephalopathy caused by methotrexate. The histology findings consisted of clusters of tumour cells along perivascular spaces, and scattered infiltration of the parenchyma, with nests of tumour cells. Leptomeningeal infiltration by tumour spread into the parenchyma and secondary degeneration of the neuronal tracts was observed. MRI was useful for detecting CNS invasion by ATL and differentiating it from other abnormalities. The MRI findings seemed to correlate well with the histological changes. (orig.)

  2. Central nervous system lesions in adult T-cell leukaemia: MRI and pathology

    Adult T-cell leukaemia (ATL) is a T-cell lymphoid neoplasm caused by human T-cell leukaemia virus type I (HTLV-I). Radiological findings in central nervous system (CNS) involvement have not been well characterised. We reviewed the MRI of 18 patients with ATL who developed new neurological symptoms or signs, and pathology specimens from a 53-year-old woman who died of ATL. MRI findings were divided into three categories: definite, probable, and other abnormal. Definite and probable findings were defined as ATL-related. The characteristic findings were multiple parenchymal masses with or without contrast enhancement adjacent to cerebrospinal fluid (CSF) spaced and the deep grey matter of both cerebral hemispheres, plus leptomeningeal lesion. One patient had both cerebral and spinal cord lesions. Other abnormal findings in eight patients included one case of leukoencephalopathy caused by methotrexate. The histology findings consisted of clusters of tumour cells along perivascular spaces, and scattered infiltration of the parenchyma, with nests of tumour cells. Leptomeningeal infiltration by tumour spread into the parenchyma and secondary degeneration of the neuronal tracts was observed. MRI was useful for detecting CNS invasion by ATL and differentiating it from other abnormalities. The MRI findings seemed to correlate well with the histological changes. (orig.)

  3. Type-Based Access Control in Data-Centric Systems

    Caires, Luís; Pérez, Jorge A.; Seco, João Costa; Vieira, Hugo Torres; Ferrão, Lúcio

    Data-centric multi-user systems, such as web applications, require flexible yet fine-grained data security mechanisms. Such mechanisms are usually enforced by a specially crafted security layer, which adds extra complexity and often leads to error prone coding, easily causing severe security breaches. In this paper, we introduce a programming language approach for enforcing access control policies to data in data-centric programs by static typing. Our development is based on the general concept of refinement type, but extended so as to address realistic and challenging scenarios of permission-based data security, in which policies dynamically depend on the database state, and flexible combinations of column- and row-level protection of data are necessary. We state and prove soundness and safety of our type system, stating that well-typed programs never break the declared data access control policies.

  4. Evaluasi Pemanfaatan Wireless Internet Protocol Access System di Kota Malang

    Ahmad Budi Setiawan

    2012-03-01

    Full Text Available WIPAS (Wireless Internet Protocol Accsess System adalah salah satu teknologi pita lebar (broadband yang terbaru. Teknologi tersebut dikembangkan berdasarkan model point-to-multipoint access system pada jaringan nirkabel tetap atau Fixed Wireless Access (FWA dengan memanfaatkan pita frekuensi 26-GHz. Dengan besarnya pita frekuensi yang digunakan, teknologi WIPAS dapat menampung kapasitas akses untuk lalu lintas jaringan yang sangat besar. Dalam penelitian ini akan dikaji dan dievaluasi efektifitas penggunaan teknologi WIPAS melalui kasus pemanfaatan teknologi WIPAS untuk pemberdayaan komunitas di kota Malang. Dalam penelitian ini juga akan dideskripsikan pemanfaatan teknologi WIPAS untuk melihat manfaat penggunaan teknologi tersebut. Penelitian ini dilakukan dengan metode kualitatif dengan melakukan evaluasi terhadap infrastruktur yang telah dibangun untuk melihat efektifitas pemanfaatan WIPAS. Hasil penelitian ini adalah sebuah kajian evaluatif tentang pemanfaatan WIPAS di kota Malang dan rekomendasi untuk implementasi lebih lanjut.

  5. Task-role-based Access Control Model in Smart Health-care System

    Wang Peng; Jiang Lingyun

    2015-01-01

    As the development of computer science and smart health-care technology, there is a trend for patients to enjoy medical care at home. Taking enormous users in the Smart Health-care System into consideration, access control is an important issue. Traditional access control models, discretionary access control, mandatory access control, and role-based access control, do not properly reflect the characteristics of Smart Health-care System. This paper proposes an advanced access control model for...

  6. Design and performance evaluation of a whole-body Ingenuity TF PET-MRI system.

    Zaidi, H; Ojha, N; Morich, M; Griesmer, J; Hu, Z; Maniawski, P; Ratib, O; Izquierdo-Garcia, D; Fayad, Z A; Shao, L

    2011-05-21

    The Ingenuity TF PET-MRI is a newly released whole-body hybrid PET-MR imaging system with a Philips time-of-flight GEMINI TF PET and Achieva 3T X-series MRI system. Compared to PET-CT, modifications to the positron emission tomography (PET) gantry were made to avoid mutual system interference and deliver uncompromising performance which is equivalent to the standalone systems. The PET gantry was redesigned to introduce magnetic shielding for the photomultiplier tubes (PMTs). Stringent electromagnetic noise requirements of the MR system necessitated the removal of PET gantry electronics to be housed in the PET-MR equipment room. We report the standard NEMA measurements for the PET scanner. PET imaging and performance measurements were done at Geneva University Hospital as described in the NEMA Standards NU 2-2007 manual. The scatter fraction (SF) and noise equivalent count rate (NECR) measurements with the NEMA cylinder (20 cm diameter) were repeated for two larger cylinders (27 cm and 35 cm diameter), which better represent average and heavy patients. A NEMA/IEC torso phantom was used for overall assessment of image quality. The transverse and axial resolution near the center was 4.7 mm. Timing and energy resolution of the PET-MR system were measured to be 525 ps and 12%, respectively. The results were comparable to PET-CT systems demonstrating that the effect of design modifications required on the PET system to remove the harmful effect of the magnetic field on the PMTs was negligible. The absolute sensitivity of this scanner was 7.0 cps kBq(-1), whereas SF was 26%. NECR measurements performed with cylinders having three different diameters, and image quality measurements performed with IEC phantom yielded excellent results. The Ingenuity TF PET-MRI represents the first commercial whole-body hybrid PET-MRI system. The performance of the PET subsystem was comparable to the GEMINI TF PET-CT system using phantom and patient studies. It is conceived that advantages

  7. DAISY Producer: An integrated production management system for accessible media

    Egli, Christian

    2011-01-01

    Large scale production of accessible media above and beyond DAISY Talking Books requires management of the workflow from the initial scan to the output of the media production. DAISY Producer was created to help manage this process. It tracks the transformation of hard copy or electronic content to DTBook XML at any stage of the workflow and interfaces to existing order processing systems. Making use of DAISY Pipeline and Liblouis, DAISY Producer fully automates the generation of on-demand, u...

  8. Scheduling with Bus Access Optimization for Distributed Embedded Systems

    Eles, Petru; Doboli, Alex; Pop, Paul;

    2000-01-01

    of control. Our goal is to derive a worst case delay by which the system completes execution, such that this delay is as small as possible; to generate a logically and temporally deterministic schedule; and to optimize parameters of the communication protocol such that this delay is guaranteed. We......, generates an efficient bus access scheme as well as the schedule tables for activation of processes and communications....

  9. A portable marine geophysical data access and management system

    Kunte, P.D.; Narvekar, P.

    COMMUNICATIONS CURRENT SCIENCE, VOL. 90, NO. 12, 25 JUNE 2006 *For correspondence. (e - mail: dr_pdkunte@yahoo.com ) A portable marine geophysical data access and ma n agement system Pravin D. Kunte 1, * and Prabhakar Narvekar 2 1 National... tio - na l data. The program calc u lates/generates the accurate position data for each fix a f ter considering the turning RESEARCH COMMUNICATIONS CURRENT SCIENCE, VOL. 90, NO. 12, 25 JUNE 2006 1659 Table 1. Database structure with field...

  10. Access control and interlock system at the Advanced Photon Source

    Forrestal, J.; Hogrefe, R.; Knott, M.; McDowell, W.; Reigle, D.; Solita, L.; Koldenhoven, R.; Haid, D. [Argonne National Lab., IL (United States). Advanced Photon Source

    1997-08-01

    The Advanced Photon Source (APS) consists of a linac, position accumulator ring (PAR), booster synchrotron, storage ring, and up to 70 experimental beamlines. The Access Control and Interlock System (ACIS) utilizes redundant programmable logic controllers (PLCs) and a third hard-wired chain to protect personnel from prompt radiation generated by the linac, PAR, synchrotron, and storage ring. This paper describes the ACIS`s design philosophy, configuration, hardware, functionality, validation requirements, and operational experience.

  11. MINIPILOT SOLAR SYSTEM: DESIGN/OPERATION OF SYSTEM AND RESULTS OF NON-SOLAR TESTING AT MRI

    Prior to this project, MRI had carried out work for the Environmental Protection Agency (EPA) on the conceptual design of a solar system for solid waste disposal and a follow-on project to study the feasibility of bench-scale testing of desorption of organics from soil with destr...

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

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

    2010-04-01

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

  13. A semi-automated vascular access system for preclinical models

    Murine models are used extensively in biological and translational research. For many of these studies it is necessary to access the vasculature for the injection of biologically active agents. Among the possible methods for accessing the mouse vasculature, tail vein injections are a routine but critical step for many experimental protocols. To perform successful tail vein injections, a high skill set and experience is required, leaving most scientists ill-suited to perform this task. This can lead to a high variability between injections, which can impact experimental results. To allow more scientists to perform tail vein injections and to decrease the variability between injections, a vascular access system (VAS) that semi-automatically inserts a needle into the tail vein of a mouse was developed. The VAS uses near infrared light, image processing techniques, computer controlled motors, and a pressure feedback system to insert the needle and to validate its proper placement within the vein. The VAS was tested by injecting a commonly used radiolabeled probe (FDG) into the tail veins of five mice. These mice were then imaged using micro-positron emission tomography to measure the percentage of the injected probe remaining in the tail. These studies showed that, on average, the VAS leaves 3.4% of the injected probe in the tail. With these preliminary results, the VAS system demonstrates the potential for improving the accuracy of tail vein injections in mice. (paper)

  14. The design and use of cryocooler in MRI systems - Experience from 3 years of operation

    Three different magnets for the whole body MRI Systems were designed and fabricated, 0.5 Tesla stationary magnet, 2.0 Tesla stationary magnet, and 0.5 Tesla mobile magnet. Different types of cryocooler were evaluated using thermal models and tested. The results of the tests were close to the calculations. The stationary magnets have 0.1 litres LHe/hr boil-off and no Nitrogen boil-off, the mobile magnets with permanent current lead have 0.3 litres LHe/hr boil-off and no Nitrogen boil-off. Magnets from those types have been working for up to three years in Elscint MRI Systems with no degradation in the performance

  15. ACCESS Earth: Promoting Accessibility to Earth System Science for Students with Disabilities

    Locke, S. M.; Cohen, L.; Lightbody, N.

    2001-05-01

    ACCESS Earth is an intensive summer institute for high school students with disabilities and their teachers that is designed to encourage students with disabilities to consider careers in earth system science. Participants study earth system science concepts at a Maine coastal estuary, using Geographic Information Systems, remote sensing, and field observations to evaluate the impacts of climate change, sea level rise, and development on coastal systems. Teachers, students, and scientists work together to adapt field and laboratory activities for persons with disabilities, including those with mobility and visual impairments. Other sessions include demonstrations of assistive technology, career discussions, and opportunities for students to meet with successful scientists with disabilities from throughout the U.S. The summer institute is one of several programs in development at the University of Southern Maine to address the problem of underrepresentation of people with disabilities in the earth sciences. Other projects include a mentoring program for high school students, a web-based clearinghouse of resources for teaching earth sciences to students with disabilities, and guidebooks for adaptation of popular published earth system science curricula for disabled learners.

  16. Multi-Channel SQUID System for MEG and Ultra-Low-Field MRI

    Zotev, Vadim S.; Matlachov, Andrei N.; Volegov, Petr L.; Sandin, Henrik J.; Espy, Michelle A.; Mosher, John C.; Urbaitis, Algis V.; Newman, Shaun G.; Kraus Jr, Robert H.

    2006-01-01

    A seven-channel system capable of performing both magnetoencephalography (MEG) and ultra-low-field magnetic resonance imaging (ULF MRI) is described. The system consists of seven second-order SQUID gradiometers with 37 mm diameter and 60 mm baseline, having magnetic field resolution of 1.2-2.8 fT/rtHz. It also includes four sets of coils for 2-D Fourier imaging with pre-polarization. The system's MEG performance was demonstrated by measurements of auditory evoked response. The system was also...

  17. Assessment of three different software systems in the evaluation of dynamic MRI of the breast

    Kurz, K.D. [Department of Radiology, Stavanger University Hospital, Postbox 8100, Stavanger (Norway)], E-mail: kurk@sus.no; Steinhaus, D. [Institute of Daignostic Radiology, Duesseldorf University Hospital, Moorenstr. 5, 40225 Duesseldorf (Germany)], E-mail: Daniele.Steinhaus@med.uni-duesseldorf.de; Klar, V. [Institute of Daignostic Radiology, Duesseldorf University Hospital, Moorenstr. 5, 40225 Duesseldorf (Germany)], E-mail: verena.klar@uni-duesseldorf.de; Cohnen, M. [Institute of Daignostic Radiology, Duesseldorf University Hospital, Moorenstr. 5, 40225 Duesseldorf (Germany)], E-mail: cohnen@med.uni-duesseldorf.de; Wittsack, H.J. [Institute of Daignostic Radiology, Duesseldorf University Hospital, Moorenstr. 5, 40225 Duesseldorf (Germany)], E-mail: wittsack@uni-duesseldorf.de; Saleh, A. [Institute of Daignostic Radiology, Duesseldorf University Hospital, Moorenstr. 5, 40225 Duesseldorf (Germany)], E-mail: saleh@uni-duesseldorf.de; Moedder, U. [Institute of Daignostic Radiology, Duesseldorf University Hospital, Moorenstr. 5, 40225 Duesseldorf (Germany)], E-mail: moedder@med.uni-duesseldorf.de; Blondin, D. [Institute of Daignostic Radiology, Duesseldorf University Hospital, Moorenstr. 5, 40225 Duesseldorf (Germany)], E-mail: blondin@med.uni-duesseldorf.de

    2009-02-15

    Objective: The aim was to compare the diagnostic performance and handling of dynamic contrast-enhanced MRI of the breast with two commercial software solutions ('CADstream' and '3TP') and one self-developed software system ('Mammatool'). Materials and methods: Identical data sets of dynamic breast MRI from 21 patients were evaluated retrospectively with all three software systems. The exams were classified according to the BI-RADS classification. The number of lesions in the parametric mapping was compared to histology or follow-up of more than 2 years. In addition, 25 quality criteria were judged by 3 independent investigators with a score from 0 to 5. Statistical analysis was performed to document the quality ranking of the different software systems. Results: There were 9 invasive carcinomas, one pure DCIS, one papilloma, one radial scar, three histologically proven changes due to mastopathy, one adenosis and two fibroadenomas. Additionally two patients with enhancing parenchyma followed with MRI for more than 3 years and one scar after breast conserving therapy were included. All malignant lesions were classified as BI-RADS 4 or 5 using all software systems and showed significant enhancement in the parametric mapping. 'CADstream' showed the best score on subjective quality criteria. '3TP' showed the lowest number of false-positive results. 'Mammatool' produced the lowest number of benign tissues indicated with parametric overlay. Conclusion: All three software programs tested were adequate for sensitive and efficient assessment of dynamic MRI of the breast. Improvements in specificity may be achievable.

  18. Benchmark IMRT evaluation of a Co-60 MRI-guided radiation therapy system

    A device for MRI-guided radiation therapy (MR-IGRT) that uses cobalt-60 sources to deliver intensity modulated radiation therapy is now commercially available. We investigated the performance of the treatment planning and delivery system against the benchmark recommended by the American Association of Physicists in Medicine (AAPM) Task Group 119 for IMRT commissioning and demonstrated that the device plans and delivers IMRT treatments within recommended confidence limits and with similar accuracy as linac IMRT

  19. Clinical application of virtual US-CT or MRI fusion navigation system in interventional radiology

    Objective: To evaluate the clinical value of virtual US-CT or MRI navigation system for guidance of interventional procedures. Methods: Virtual US-CT or MRI fusion navigation system was applied on 47 cases for guiding various interventional procedures. The operating method, success rate, clinical outcome, and complication of the navigating interventional technique were retrospectively analyzed. Thirtyeight cases of hepatic tumors underwent percutaneous needle biopsy and / or radiofrequency ablation (RFA); 4 cases of hepatic abscess underwent percutaneous abscess rainage, 5 cases of musculoskeletal diseases underwent biopsy, RFA or RFA with cementoplasty. Results: For 38 cases of hepatic tumors who underwent RFA, 27 acquired complete ablation in one session, no recurrence after 3.0-6.0 months (median time 4.8 months) follow-up; while the other 11 cases present with no significant change. Five cases of musculoskeletal diseases improved significantly after interventional therapy and pathological diagnoses were also acquired. Four cases of hepatic abscesses were cured after drainage. All cases were free of significant complication, except one local skin thermal damage. Conclusion: Virtual US-CCT or MRI navigation guiding technique provides mutual aid to different imaging modalities for guiding interventional procedure. After application of navigation system, those interventional procedures may become more convenient, more effective and safer. (authors)

  20. Intra-coil interactions in split gradient coils in a hybrid MRI-LINAC system

    Tang, Fangfang; Freschi, Fabio; Sanchez Lopez, Hector; Repetto, Maurizio; Liu, Feng; Crozier, Stuart

    2016-04-01

    An MRI-LINAC system combines a magnetic resonance imaging (MRI) system with a medical linear accelerator (LINAC) to provide image-guided radiotherapy for targeting tumors in real-time. In an MRI-LINAC system, a set of split gradient coils is employed to produce orthogonal gradient fields for spatial signal encoding. Owing to this unconventional gradient configuration, eddy currents induced by switching gradient coils on and off may be of particular concern. It is expected that strong intra-coil interactions in the set will be present due to the constrained return paths, leading to potential degradation of the gradient field linearity and image distortion. In this study, a series of gradient coils with different track widths have been designed and analyzed to investigate the electromagnetic interactions between coils in a split gradient set. A driving current, with frequencies from 100 Hz to 10 kHz, was applied to study the inductive coupling effects with respect to conductor geometry and operating frequency. It was found that the eddy currents induced in the un-energized coils (hereby-referred to as passive coils) positively correlated with track width and frequency. The magnetic field induced by the eddy currents in the passive coils with wide tracks was several times larger than that induced by eddy currents in the cold shield of cryostat. The power loss in the passive coils increased with the track width. Therefore, intra-coil interactions should be included in the coil design and analysis process.

  1. Privacy and Access Control for IHE-Based Systems

    Katt, Basel; Breu, Ruth; Hafner, Micahel; Schabetsberger, Thomas; Mair, Richard; Wozak, Florian

    Electronic Health Record (EHR) is the heart element of any e-health system, which aims at improving the quality and efficiency of healthcare through the use of information and communication technologies. The sensitivity of the data contained in the health record poses a great challenge to security. In this paper we propose a security architecture for EHR systems that are conform with IHE profiles. In this architecture we are tackling the problems of access control and privacy. Furthermore, a prototypical implementation of the proposed model is presented.

  2. Authorisation and access control for electronic health record systems.

    Blobel, Bernd

    2004-03-31

    Enabling the shared care paradigm, centralised or even decentralised electronic health record (EHR) systems increasingly become core applications in hospital information systems and health networks. For realising multipurpose use and reuse as well as inter-operability at knowledge level, EHR have to meet special architectural requirements. The component-oriented and model-based architecture should meet international standards. Especially in extended health networks realising inter-organisational communication and co-operation, authorisation cannot be organised at user level anymore. Therefore, models, methods and tools must be established to allow formal and structured policy definition, policy agreements, role definition, authorisation and access control. Based on the author's international engagement in EHR architecture and security standards referring to the revision of CEN ENV 13606, the GEHR/open EHR approach, HL7 and CORBA, models for health-specific and EHR-related roles, for authorisation management and access control have been developed. The basic concept is the separation of structural roles defining organisational entity-to-entity relationships and enabling specific acts on the one hand, and functional roles bound to specific activities and realising rights and duties on the other hand. Aggregation of organisational, functional, informational and technological components follows specific rules. Using UML and XML, the principles as well as some examples for analysis, design, implementation and maintenance of policy and authorisation management as well as access control have been practically implemented. PMID:15066555

  3. Licensed Shared Access System Possibilities for Public Safety

    Kalle Lähetkangas

    2016-01-01

    Full Text Available We investigate the licensed shared access (LSA concept based spectrum sharing ideas between public safety (PS and commercial radio systems. While the concept of LSA has been well developed, it has not been thoroughly investigated from the public safety (PS users’ point of view, who have special requirements and also should benefit from the concept. Herein, we discuss the alternatives for spectrum sharing between PS and commercial systems. In particular, we proceed to develop robust solutions for LSA use cases where connections to the LSA system may fail. We simulate the proposed system with different failure models. The results show that the method offers reliable LSA spectrum sharing in various conditions assuming that the system parameters are set properly. The paper gives guidelines to set these parameters.

  4. A Rewritable, Random-Access DNA-Based Storage System

    Tabatabaei Yazdi, S. M. Hossein; Yuan, Yongbo; Ma, Jian; Zhao, Huimin; Milenkovic, Olgica

    2015-09-01

    We describe the first DNA-based storage architecture that enables random access to data blocks and rewriting of information stored at arbitrary locations within the blocks. The newly developed architecture overcomes drawbacks of existing read-only methods that require decoding the whole file in order to read one data fragment. Our system is based on new constrained coding techniques and accompanying DNA editing methods that ensure data reliability, specificity and sensitivity of access, and at the same time provide exceptionally high data storage capacity. As a proof of concept, we encoded parts of the Wikipedia pages of six universities in the USA, and selected and edited parts of the text written in DNA corresponding to three of these schools. The results suggest that DNA is a versatile media suitable for both ultrahigh density archival and rewritable storage applications.

  5. Functional MRI of the olfactory system in conscious dogs.

    Hao Jia

    Full Text Available We depend upon the olfactory abilities of dogs for critical tasks such as detecting bombs, landmines, other hazardous chemicals and illicit substances. Hence, a mechanistic understanding of the olfactory system in dogs is of great scientific interest. Previous studies explored this aspect at the cellular and behavior levels; however, the cognitive-level neural substrates linking them have never been explored. This is critical given the fact that behavior is driven by filtered sensory representations in higher order cognitive areas rather than the raw odor maps of the olfactory bulb. Since sedated dogs cannot sniff, we investigated this using functional magnetic resonance imaging of conscious dogs. We addressed the technical challenges of head motion using a two pronged strategy of behavioral training to keep dogs' head as still as possible and a single camera optical head motion tracking system to account for residual jerky movements. We built a custom computer-controlled odorant delivery system which was synchronized with image acquisition, allowing the investigation of brain regions activated by odors. The olfactory bulb and piriform lobes were commonly activated in both awake and anesthetized dogs, while the frontal cortex was activated mainly in conscious dogs. Comparison of responses to low and high odor intensity showed differences in either the strength or spatial extent of activation in the olfactory bulb, piriform lobes, cerebellum, and frontal cortex. Our results demonstrate the viability of the proposed method for functional imaging of the olfactory system in conscious dogs. This could potentially open up a new field of research in detector dog technology.

  6. Towards an hybrid system for annotating brain MRI images

    Mechouche, Ammar; Golbreich, Christine; Gibaud, Bernard

    2006-01-01

    This paper describes a method combining symbolic and numerical techniques for annotating brain Magnetic Resonance images. The goal is to assist existing automatic labelling methods which are mostly statistical in nature and do not work very well in certain situations such as the presence of lesions. The system uses existing statistical methods for generating ABox facts that constitute a set of initial information sufficient for fruitful reasoning. The reasoning is supported by an OWL ontology...

  7. Bluetooth Navigation System Using WI-FI Access Points

    Rohit Agrawal

    2012-04-01

    Full Text Available There have been various navigation and tracking systems being developed with the help of technologies like GPS, GSM, Bluetooth, IR, Wi-Fi and Radar. Outdoor positioning systems have been deployed quite successfully using GPS but positioning systems for indoor environments still do not have widespread deployment due to various reasons. Most of these use only a single technology for positioning but using more than one in cooperation with each other is always advantageous for obtaining greater accuracy. Particularly, the ones which use Bluetooth are better since they would enhance the scalability of such a system because of the fact that this technology is in use by the common people so it would always be easy to track them. Moreover it would also reduce the hardware installation cost to some extent. The systemthat has been introduced here uses bluetooth primarily for positioning and tracking in combination with Wi-Fi access points. The reason that makes the commercial application of such a system easier and cheaper is that most of the localized areas today like college campus, offices are being provided withinternet connectivity using these access points.

  8. RF Head Coil Design with Improved RF Magnetic Near-Fields Uniformity for Magnetic Resonance Imaging (MRI) Systems

    Sohn, Sung-Min; DelaBarre, Lance; Gopinath, Anand; Vaughan, John Thomas

    2014-01-01

    Higher magnetic field strength in magnetic resonance imaging (MRI) systems offers higher signal-to-noise ratio (SNR), contrast, and spatial resolution in MR images. However, the wavelength in ultra-high fields (7 tesla and beyond) becomes shorter than the human body at the Larmor frequency with increasing static magnetic field (B0) of MRI system. At short wavelengths, interference effect appears resulting in non- uniformity of the RF magnetic near-field (B1) over the subject and MR images may...

  9. Realtime organ motion tracking and fast image registration system for MRI guided surgery

    We developed a realtime organ motion tracking/image registration system embedded in a 1.5 clinical MR scanner to track a target organ in realtime in MRI guided therapy. The displacement of the target organ is measured by projection profile matching, based on navigator echo technique. The phantom and volunteer studies showed that the system can provide the information of respiratory motion of the liver with frame rate of up to 10 Hz, delay of 200 ms and error of 2.0 mm, and the system was feasible in clinical use. (author)

  10. Microcomputer-based image processing system for CT/MRI scans II

    This paper reports that a microcomputer-based image processing system is used to digitize and process serial sections of CT/MRI scan and reconstruct three-dimensional images of brain structures and brain lesions. The images grabbed also serve as templates and different vital regions with different risk values are also traced out for 3D reconstruction. A knowledge-based system employing rule-based programming has been built to help identifying brain lesions and to help planning trajectory for operations. The volumes of the lesions are also automatically determined. Such system is very useful for medical skills archival, tumor size monitoring, survival and outcome forecasting, and consistent neurosurgical planning

  11. Use of CDMA access technology in mobile satellite systems

    Ramasastry, Jay; Wiedeman, Bob

    1995-01-01

    Use of Code Division Multiple Access (CDMA) technology in terrestrial wireless systems is fairly well understood. Similarly, design and operation of Power Control in a CDMA-based system in a terrestrial environment is also well established. Terrestrial multipath characteristics, and optimum design of the CDMA receiver to deal with multipath and fading conditions are reliably established. But the satellite environment is different. When the CDMA technology is adopted to the satellite environment, other design features need to be incorporated (for example; interleaving, open-loop and closed-loop power control design, diversity characteristics) to achieve comparable level of system performance. In fact, the GLOBALSTAR LEO/MSS system has incorporated all these features. Contrary to some published reports, CDMA retains the advantages in the satellite environment that are similar to those achieved in the terrestrial environment. This document gives a description of the CDMA waveform and other design features adopted for mobile satellite applications.

  12. Towards motion insensitive EEG-fMRI: Correcting motion-induced voltages and gradient artefact instability in EEG using an fMRI prospective motion correction (PMC) system.

    Maziero, Danilo; Velasco, Tonicarlo R; Hunt, Nigel; Payne, Edwin; Lemieux, Louis; Salmon, Carlos E G; Carmichael, David W

    2016-09-01

    The simultaneous acquisition of electroencephalography and functional magnetic resonance imaging (EEG-fMRI) is a multimodal technique extensively applied for mapping the human brain. However, the quality of EEG data obtained within the MRI environment is strongly affected by subject motion due to the induction of voltages in addition to artefacts caused by the scanning gradients and the heartbeat. This has limited its application in populations such as paediatric patients or to study epileptic seizure onset. Recent work has used a Moiré-phase grating and a MR-compatible camera to prospectively update image acquisition and improve fMRI quality (prospective motion correction: PMC). In this study, we use this technology to retrospectively reduce the spurious voltages induced by motion in the EEG data acquired inside the MRI scanner, with and without fMRI acquisitions. This was achieved by modelling induced voltages from the tracking system motion parameters; position and angles, their first derivative (velocities) and the velocity squared. This model was used to remove the voltages related to the detected motion via a linear regression. Since EEG quality during fMRI relies on a temporally stable gradient artefact (GA) template (calculated from averaging EEG epochs matched to scan volume or slice acquisition), this was evaluated in sessions both with and without motion contamination, and with and without PMC. We demonstrate that our approach is capable of significantly reducing motion-related artefact with a magnitude of up to 10mm of translation, 6° of rotation and velocities of 50mm/s, while preserving physiological information. We also demonstrate that the EEG-GA variance is not increased by the gradient direction changes associated with PMC. Provided a scan slice-based GA template is used (rather than a scan volume GA template) we demonstrate that EEG variance during motion can be supressed towards levels found when subjects are still. In summary, we show that

  13. MRI of prostate cancer using three different coil systems: image quality, tumor detection, and staging

    Purpose: To compare three MRI coil systems in terms of image quality, delineation of prostate cancer, and tumor staging. Materials and Methods: 49 patients with prostate cancer underwent MRI at 1.5 Tesla using a combination of an endorectal coil with a phased-array body coil (combination coil) prior to radical prostatectomy. Images were reconstructed from the data sets acquired with the endorectal coil alone and from those acquired with the combined coil. In addition, 19 patients of the study patients were examined with the body phased-array coil alone without the endorectal coil. The prostate was imaged at a slice thickness of 3 mm using axial and coronal T2-weighted sequences and an axial T1-weighted sequence. Preoperative analysis of all images acquired was done to determine the accuracy of MRI in local staging of prostate cancer. An additional retrospective analysis served to compare the different coil systems in terms of overall image quality, delineation and localization of the tumor, and criteria for local staging of prostate cancer. Results: Preoperative analysis showed MRI to have an accuracy of 59% in local tumor staging. Retrospective coil-by-coil analysis demonstrated image quality and tumor delineation to be best for the combination coil and the endorectal coil. Regarding the staging criteria for transcapsular tumor extension and infiltration of adjacent organs, a significant advantage of the combination coil compared to the endorectal coil was identified only for the criterion of smooth bulging. In addition, the endorectal coil and the combination coil were found to be superior to the body phased-array coil in assessing 15 of 17 criteria for local tumor staging but the differences were not significant. Conclusion: In view of the achieved superior image quality, the combination coil or the endorectal coil is the preferred method for staging prostate cancer. (orig.)

  14. MRI in central nervous system infections: A simplified patterned approach

    Krithika; Rangarajan; Chandan; J; Das; Atin; Kumar; Arun; Kumar; Gupta

    2014-01-01

    Recognition and characterization of central nervous system infections poses a formidable challenge to the neuro-radiologist.Imaging plays a vital role,the lesions typically being relatively inaccessible to tisue sampling.The results of an accurate diagnosis are endlessly re-warding,given the availability of excellent pharmaco-logical regimen.The availability of numerous magnetic resonance(MR)sequences which provide functional and molecular information is a powerful tool in the hands of the radiologist.However,the plethora of se-quences and the possibilities on each sequence is also intimidating,and often confusing as well as time con-suming.While a large number of reviews have already described in detail the possible imaging findings in each infection,we intend to classify infections based on their imaging characteristics.In this review we describe an algorithm for first classifying the imaging findings into patterns based on basic MR sequences(T1,T2 and enhancement pattern with Gadolinium),and then sub-classify them based on more advanced molecular and functional sequences(Diffusion,Perfusion,Susceptibili-ty imaging,MR Spectroscopy).This patterned approachis intended as a guide to radiologists in-training and in-practice for quickly narrowing their list of differentials when faced with a clinical challenge.The entire content of the article has also been summarised in the form of flow-charts for the purpose of quick reference.

  15. MRI in central nervous system infections: A simplified patterned approach.

    Rangarajan, Krithika; Das, Chandan J; Kumar, Atin; Gupta, Arun Kumar

    2014-09-28

    Recognition and characterization of central nervous system infections poses a formidable challenge to the neuro-radiologist. Imaging plays a vital role, the lesions typically being relatively inaccessible to tisue sampling. The results of an accurate diagnosis are endlessly rewarding, given the availability of excellent pharmacological regimen. The availability of numerous magnetic resonance (MR) sequences which provide functional and molecular information is a powerful tool in the hands of the radiologist. However, the plethora of sequences and the possibilities on each sequence is also intimidating, and often confusing as well as time consuming. While a large number of reviews have already described in detail the possible imaging findings in each infection, we intend to classify infections based on their imaging characteristics. In this review we describe an algorithm for first classifying the imaging findings into patterns based on basic MR sequences (T1, T2 and enhancement pattern with Gadolinium), and then sub-classify them based on more advanced molecular and functional sequences (Diffusion, Perfusion, Susceptibility imaging, MR Spectroscopy). This patterned approach is intended as a guide to radiologists in-training and in-practice for quickly narrowing their list of differentials when faced with a clinical challenge. The entire content of the article has also been summarised in the form of flow-charts for the purpose of quick reference. PMID:25276314

  16. Simultaneous fMRI-PET of the Opioidergic Pain System in Human Brain

    Wey, HY; Catana, C.; Hooker, JM; Dougherty, DD; Knudsen, GM; Wang, DJJ; Chonde, DB; Rosen, BR; Gollub, RL; Kong, J.

    2014-01-01

    MRI and PET provide complementary information for studying brain function. While the potential use of simultaneous MRI/PET for clinical diagnostic and disease staging has been demonstrated recently; the biological relevance of concurrent functional MRI-PET brain imaging to dissect neurochemically distinct components of the blood oxygenation level dependent (BOLD) fMRI signal has not yet been shown. We obtained sixteen fMRI-PET data sets from eight healthy volunteers. Each subject participated...

  17. Nomadic Computing : Security assessment of remote access to workplace systems

    Karlsson, Johanna

    2003-01-01

    Nomadic computing is about communication on an anytime anywhere basis. Security in this area is today not high enough and at the same time nomadic computing is increasing. In this thesis, security in the area of nomadic computing and remote access to company systems is assessed. The purpose is to investigate the security in this area today but also in the future in order to answer the main question of how and when secure nomadic computing can be offered. For this purpose a futuristic scenario...

  18. Fetal MRI

    New, ultrafast sequences have made it possible to obtain MR images of the fetus without maternal sedation or immobilization of the fetus itself. While fetal MRI began as an adjunct to ultrasound, it has now been shown that MRI can provide additional information that may change prognosis, the management of pregnancy, or the treatment of the newborn child. It is of particular value in the assessment of malformations of the central nervous system. The steady development and adaptation of MR-sequences to the needs of fetal imaging has led to new indications that can support prognostic and therapeutic decisions. (orig.)

  19. Fetal MRI

    Prayer, D.; Brugger, P.C. [University Hospital of Vienna (Austria). Division of Neuroradiology

    2004-07-01

    New, ultrafast sequences have made it possible to obtain MR images of the fetus without maternal sedation or immobilization of the fetus itself. While fetal MRI began as an adjunct to ultrasound, it has now been shown that MRI can provide additional information that may change prognosis, the management of pregnancy, or the treatment of the newborn child. It is of particular value in the assessment of malformations of the central nervous system. The steady development and adaptation of MR-sequences to the needs of fetal imaging has led to new indications that can support prognostic and therapeutic decisions. (orig.)

  20. A recently developed MRI scoring system for hand osteoarthritis: its application in a clinical setting.

    Ramonda, Roberta; Favero, Marta; Vio, Stefania; Lacognata, Carmelo; Frallonardo, Paola; Belluzzi, Elisa; Campana, Carla; Lorenzin, Mariagrazia; Ortolan, Augusta; Angelini, Federico; Piccoli, Antonio; Oliviero, Francesca; Punzi, Leonardo

    2016-08-01

    This study aimed to apply the recently proposed Oslo hand osteoarthritis magnetic resonance imaging (MRI) scoring system to evaluate MRI findings in a cohort of patients affected by long-standing erosive hand osteoarthritis (EHOA). Eleven female EHOA patients (median 59 [interquartile range 62-52] years, disease duration 9.5 [interquartile range 13-3.75] years) underwent MRI (1.5 T) of the dominant hand, and synovitis, bone marrow lesions (BMLs), joint space narrowing, osteophytes, cysts, malalignment, and erosions were scored using the Oslo scoring system. Intra- and inter-reader reliability were assessed. The patients also underwent X-ray examination, and bone features were evaluated using the same scoring system. Pain and tenderness were assessed during a physical examination. Spearman's non-parametric test was used to analyze the correlations between variables. MRI intra- and inter-reader reliability were found between good and moderate for many features. No statistical differences were found between the radiographs and MRI with regard to detection of JSN, malalignment, and bone erosions. Synovitis was detected in 39.8 % of the 80 joints examined (in a mild form in 80 %), erosions were found in 51.1 %, and BMLs were identified in 20.5 and 23.9 % at the distal and the proximal side, respectively. BMLs at both the proximal and distal ends were correlated with tender joints (BML distal p = 0.0013, BML proximal p = 0.012). The presence of synovitis was correlated with tenderness (p = 0.004) and erosions at both the distal and proximal joints (p = 0.004). The presence of erosions correlated with tender joints (p < 0.01) and the mean visual analog scale (VAS) score (distal p = 0.03, proximal p = 0.01). Synovitis and BMLs were correlated with clinical symptoms in our patients affected with long-standing EHOA. PMID:27236512

  1. Access Control in Decentralised Publish/Subscribe Systems

    Lauri I.W. Pesonen

    2007-04-01

    Full Text Available Publish/subscribe has emerged as an attractive communication paradigm for building Internet-wide distributed systems by decoupling message senders from receivers. Large scale publish/subscribe systems are likely to employ components of the event transport network owned by cooperating, but independent organisations. As the number of participants in the network increases, security becomes an increasing concern. So far most of the research on publish/subscribe has focused on efficient event routing, event filtering, and composite event detection. Very little research has been published regarding securing publish/subscribe systems. This paper extends our previous work to present and evaluate a secure multi-domain publish/subscribe infrastructure that supports and enforces fine-grained access control over the individual attributes of event types.

  2. Channel Fragmentation in Dynamic Spectrum Access Systems - a Theoretical Study

    Coffman, Ed; Simatos, Florian; Tarumi, Shuzo; Zussman, Gil

    2010-01-01

    Dynamic Spectrum Access systems exploit temporarily available spectrum (`holes' or `white spaces') and can spread transmissions over a number of non-contiguous sub-channels. Such methods can have significant benefits in terms of spectrum utilization. However, excessive fragmentation degrades performance and hence off-sets the benefits. Thus, there is a critical need for an in-depth understanding of these processes so as to determine how best to ensure acceptable levels of fragmentation. We address this need by presenting experimental and analytical results derived from a mathematical model. In particular, we model a system operating at capacity serving requests for bandwidth by assigning as needed a collection of gaps (sub-channels) with no limitations on fragment size. Our main theoretical result shows that even if fragments can be arbitrarily small, the system does not degrade with time; i.e., the average total number of fragments remains bounded. Within the very difficult class of dynamic fragmentation mod...

  3. Electron contamination modeling and reduction in a 1 T open bore inline MRI-linac system

    Oborn, B. M. [Illawarra Cancer Care Centre (ICCC), Wollongong, NSW 2500, Australia and Centre for Medical Radiation Physics (CMRP), University of Wollongong, Wollongong, NSW 2500 (Australia); Kolling, S. [Sydney Medical School, University of Sydney, NSW 2006 (Australia); Metcalfe, P. E. [Centre for Medical Radiation Physics (CMRP), University of Wollongong, Wollongong, NSW 2500, Australia and Ingham Institute for Applied Medical Research, Liverpool, NSW 2170 (Australia); Crozier, S. [School of Information Technology and Electric Engineering, University of Queensland, QLD 4072 (Australia); Litzenberg, D. W. [Department of Radiation Oncology, University of Michigan Hospital and Health Systems, Ann Arbor, Michigan 48109 (United States); Keall, P. J. [Sydney Medical School, University of Sydney, NSW 2006, Australia and Ingham Institute for Applied Medical Research, Liverpool, NSW 2170 (Australia)

    2014-05-15

    Purpose: A potential side effect of inline MRI-linac systems is electron contamination focusing causing a high skin dose. In this work, the authors reexamine this prediction for an open bore 1 T MRI system being constructed for the Australian MRI-Linac Program. The efficiency of an electron contamination deflector (ECD) in purging electron contamination from the linac head is modeled, as well as the impact of a helium gas region between the deflector and phantom surface for lowering the amount of air-generated contamination. Methods: Magnetic modeling of the 1 T MRI was used to generate 3D magnetic field maps both with and without the presence of an ECD located immediately below the MLC’s. Forty-seven different ECD designs were modeled and for each the magnetic field map was imported into Geant4 Monte Carlo simulations including the linac head, ECD, and a 30 × 30 × 30 cm{sup 3} water phantom located at isocenter. For the first generation system, the x-ray source to isocenter distance (SID) will be 160 cm, resulting in an 81.2 cm long air gap from the base of the ECD to the phantom surface. The first 71.2 cm was modeled as air or helium gas, with the latter encased between two windows of 50 μm thick high density polyethlyene. 2D skin doses (at 70 μm depth) were calculated across the phantom surface at 1 × 1 mm{sup 2} resolution for 6 MV beams of field size of 5 × 5, 10 × 10, and 20 × 20 cm{sup 2}. Results: The skin dose was predicted to be of similar magnitude as the generic systems modeled in previous work, 230% to 1400% ofD {sub max} for 5 × 5 to 20 × 20 cm{sup 2}, respectively. Inclusion of the ECD introduced a nonuniformity to the MRI imaging field that ranged from ∼20 to ∼140 ppm while the net force acting on the ECD ranged from ∼151 N to ∼1773 N. Various ECD designs were 100% efficient at purging the electron contamination into the ECD magnet banks; however, a small percentage were scattered back into the beam and continued to the phantom

  4. MR-guided discography using an open 1 Tesla MRI system

    To evaluate the feasibility of MR-guided discography using an open 1 Tesla MRI system. 48 disc segments of 41 patients scheduled for intradiscal thermal treatment, total disc replacement or spondylodesis were examined. A 1.0-T open MRI was used for instrument guidance and imaging. After primary disc puncture under guidance of interactive PDw TSE imaging, 1-2 ml of gadolinium contrast saline mixture was injected into the disc. The occurrence of memory pain during injection was recorded. Axial and sagittal T1w TSE images with and without fat saturation were obtained. All MRI discograms were analysed by two readers, who were blinded to the clinical findings. Overall, the placement of the puncture needle in the targeted disc was accurate under real-time MR guidance. Injections were technically successful in all cases. No major complications occurred. The mean procedure time was 17 min (range 13-34 min). Image quality of contrast-enhanced MR discograms was excellent when using an optimized gadolinium contrast saline mixture of 1:600. Memory pain was detected in 16 out of 48 affected segments. MR-guided discography is accurate and safe. Multiplanar dynamic imaging facilitates the puncture of discs and provides high-quality MR discograms. (orig.)

  5. ISPMER: Integrated system for combined PET, MRI, and electrophysiological recording in somatosensory studies in rats

    The present study developed an integrated system for use in combined PET, MRI, and electrophysiological recording in somatosensory studies in rats, called ISPMER. A stereotaxic frame was designed for animal positioning that could be used in all three measurement modalities, and its dimensions complied with the gold standard of the Paxinos and Watson rat brain atlas. A graphical user interface was developed for analyzing the data using several signal processing algorithms. This integrated system provides a novel interface for the recording and processing of three-dimensional neuronal signals in three modalities

  6. Low-field MRI for studies of human pulmonary physiology and traumatic brain injury

    Wilson, Alyssa; Devience, Stephen; Rosen, Matthew; Walsworth, Ronald

    2011-05-01

    We describe recent progress on the development of an open-access low-magnetic-field MRI system for studies of human pulmonary physiology and traumatic brain injury. Low-field MRI benefits from reduced magnetic susceptibility effects and can provide high-resolution images of the human body when used with hyperpolarized media such as 3He and 129Xe.

  7. Effective Connectivity Modeling for fMRI: Six Issues and Possible Solutions Using Linear Dynamic Systems

    Jason Fitzgerald Smith

    2012-01-01

    Full Text Available Analysis of directionally specific or causal interactions between regions in functional magnetic resonance imaging (fMRI data has proliferated. Here we identify six issues with existing effective connectivity methods that need addressed. The issues are discussed within the framework of Linear Dynamic Systems for fMRI (LDSf. The first concerns the use of deterministic models to identify inter-regional effective connectivity. We show that deterministic dynamics are incapable of identifying the trial-to-trial variability typically investigated as the marker of connectivity while stochastic models can capture this variability. The second concerns the simplistic (constant connectivity modeled by most methods. Connectivity parameters of the LDSf model can vary at the same timescale as the input data. Further, extending LDSf to mixtures of multiple models provides more robust connectivity variation. The third concerns the correct identification of the network itself including the number and anatomical origin of the network nodes. Augmentation of the LDSf state space can identify additional nodes of a network. The fourth concerns the locus of the signal used as a “node” in a network. A novel extension LDSf incorporating sparse canonical correlations can select most relevant voxels from an anatomically defined region based on connectivity. The fifth concerns connection interpretation. Individual parameter differences have received most attention. We present alternative network descriptors of connectivity changes which consider the whole network. The sixth concerns the temporal resolution of fMRI data relative to the timescale of the inter-regional interactions in the brain. LDSf includes an “instantaneous” connection term to capture connectivity occurring at timescales faster than the data resolution. The LDS framework can also be extended to statistically combine fMRI and EEG data. The LDSf framework is a promising foundation for effective

  8. MRI zoo

    Laustsen, Christoffer

    The basic idea was to use MRI to produce a sequence of 3D gray scale image slices of various animals, subsequentlyimaged with a clinical CT system. For this purpose, these animals were used: toad, lungfish, python snake and a horseshoe crab. Each animal was sacrificed according to standard proced...

  9. Development of Ultra-low Field SQUID-MRI System with an LC Resonator

    Yamamoto, M.; Toyota, H.; Kawagoe, S.; Hatta, J.; Tanaka, S.

    We are developing an Ultra-Low Field (ULF) magnetic resonance imaging (MRI) system using high temperature superconductor (HTS)-rf-superconducting quantum interference device (SQUID) for food inspection. The advantage of the ULF MRI system is that non-magnetic contaminants, which are difficult to be detected by a magnetic sensor, can be detected and localized. The system uses HTS-SQUID with high sensitivity that is independent of frequency, because the signal frequency is reduced in ULF. However the detection area of HTS-SQUID is difficult to be increased. Therefore, we studied to increase the detection area using an LC resonator. The LC resonator is composed of a coil (22.9 mH, Φ40 mm inner diameter) and a capacitor (the setting resonance frequency of 1890 Hz). The signal is detected by a copper wound coil of the resonator, and transferred to HTS-SQUID that inductively coupled to the coil immersed in liquid nitrogen at 77 K. We combined the LC resonator with the ULF MRI system, and obtained the 2D-MR images. The signal detector, with the SQUID and the LC resonator, provided a 1.5 times larger detection area. The size of 2D-MR image was near the size of the actual sample. Then we obtained 2D-MR images by a filtered back projection (FBP) method and a 2D-fast fourier transform (FFT) method. In the 2D-FFT method, the pixel size of the image was smaller than that of image by FBP method. As a result, the quality of the 2D-MR image by 2D-FFT method has been improved. There results suggested that the system we are proposing is feasible.

  10. Accessibility of a Destination-Based Transportation System: A Large Airport Study

    SHI Jing; YING Xiwen

    2008-01-01

    The accessibility of a destination-based transportation system is defined to quantify the perform-ance of transportation systems which access a distinct destination. The access cost is used to reflect the utility of the transportation system including the fatigue and inconvenience in the total cost. The cost is quan-tified by two coefficients which represent the different characteristics of various people. The average cost and the income-relative accessibility are used to describe various aspects of the accessibility and to evaluate the accessibility of a destination-based system. A case study uses data from the Kunming transpor-tation system to evaluate the accessibility of the present city airport. The calibrated coefficients are then used to evaluate the transportation system to the new Kunming international airport. The results show that this transportation accessibility evaluation can be combined with transportation planning to study transporta-tion sub-systems.

  11. 77 FR 25525 - Thirteenth Meeting: RTCA Special Committee 224, Airport Security Access Control Systems.

    2012-04-30

    ... Access Control Systems. AGENCY: Federal Aviation Administration (FAA), U.S. Department of Transportation (DOT). ACTION: Meeting Notice of RTCA Special Committee 224, Airport Security Access Control Systems... Committee 224, Airport Security Access Control Systems DATES: The meeting will be held May 30, 2012, from...

  12. 77 FR 2343 - Eleventh Meeting: RTCA Special Committee 224, Airport Security Access Control Systems

    2012-01-17

    ...). ACTION: Notice of RTCA Special Committee 224, Airport Security Access Control Systems. SUMMARY: The FAA..., Airport Security Access Control Systems. DATES: The meeting will be held February 9, 2012, from 10 a.m.-4..., Airport Security Access Control Systems. The agenda will include the following: February 9, 2012...

  13. Bluetooth Navigation System using Wi-Fi Access Points

    Agrawal, Rohit

    2012-01-01

    There have been various navigation and tracking systems being developed with the help of technologies like GPS, GSM, Bluetooth, IR, Wi-Fi and Radar. Outdoor positioning systems have been deployed quite successfully using GPS but positioning systems for indoor environments still do not have widespread deployment due to various reasons. Most of these use only a single technology for positioning but using more than one in cooperation with each other is always advantageous for obtaining greater accuracy. Particularly, the ones which use Bluetooth are better since they would enhance the scalability of such a system because of the fact that this technology is in use by the common people so it would always be easy to track them. Moreover it would also reduce the hardware installation cost to some extent. The system that has been introduced here uses Bluetooth primarily for positioning and tracking in combination with Wi-Fi access points. The reason that makes the commercial application of such a system easier and ch...

  14. Permanent Magnet System for MRI with Constant Gradient mechanically adjustable in Direction and Strength

    Blümler, Peter

    2015-01-01

    A design for a permanent magnet system is proposed that generates spatially homogeneous, constant magnetic field gradients, thus creating conditions suitable for MRI without gradient coils and amplifiers. This is achieved by superimposing a weak Halbach quadrupole on a strong Halbach dipole. Rotation of either the quadrupole or the entire magnet assembly can be used to generate 2D images via filtered back-projection. Additionally, the mutual rotation of two quadrupoles can be used to scale the resulting gradient. If both gradients have identical strength the gradient can even be made to vanish. The concept is demonstrated by analytical considerations and FEM-simulations.

  15. Safety systems and access control in the National Ignition Facility.

    Reed, Robert K; Bell, Jayce C

    2013-06-01

    The National Ignition Facility (NIF) is the world's largest and most energetic laser system. The facility has the potential to generate ionizing radiation due to the interaction between the laser beams and target material, with neutrons and gamma rays being produced during deuterium-tritium fusion reactions. To perform these experiments, several types of hazards must be mitigated and controlled to ensure personnel safety. NIF uses a real-time safety system to monitor and mitigate the hazards presented by the facility. The NIF facility Safety Interlock System (SIS) monitors for oxygen deficiency and controls access to the facility preventing exposure to laser light and radiation from the Radiation Generating Devices. It also interfaces to radiation monitoring and other radiological monitoring and alarm systems. The SIS controls permissives to the hazard-generating equipment and annunciates hazard levels in the facility. To do this reliably and safely, the SIS has been designed as a fail-safe system with a proven performance record now spanning over 10 y. This paper discusses the SIS, its design, implementation, operator interfaces, validation/verification, and the hazard mitigation approaches employed in the NIF. A brief discussion of the Failure Modes and Effect Analysis supporting the SIS will also be presented. The paper ends with a general discussion of SIS do's and don'ts and common design flaws that should be avoided in SIS design. PMID:23629061

  16. Access to Papanicolaou Test by the Unified Health System users

    Vanessa Franco de Carvalho; Nalú Pereira da Costa Kerber; Vanessa Andréia Wachholz; Flávia Conceição Pohlmann; Letícia Amico Marques; Fabiane Ferreira Francioni

    2016-01-01

    Objective: to understand how is the access to the public health service users in the Papanicolaou Test. Methods: qualitative study, with 52 women who have changes in the Pap smear exam, questioning the exam achievement frequency and the difficulties of its access and the consultations. It was developed a thematic analysis based on the Fekete accessibility reference. Results: three categories emerged: access to information on the frequency of Pap smears, highlighting the completion of the exam...

  17. Cloud Radio Access Network: Virtualizing Wireless Access for Dense Heterogeneous Systems

    Simeone, Osvaldo; Maeder, Andreas; Peng, Mugen; Sahin, Onur; Yu, Wei

    2015-01-01

    Cloud Radio Access Network (C-RAN) refers to the virtualization of base station functionalities by means of cloud computing. This results in a novel cellular architecture in which low-cost wireless access points, known as radio units (RUs) or remote radio heads (RRHs), are centrally managed by a reconfigurable centralized "cloud", or central, unit (CU). C-RAN allows operators to reduce the capital and operating expenses needed to deploy and maintain dense heterogeneous networks. This critical...

  18. Title III Evaluation Report for the Access Road System

    The objective of this evaluation is to provide recommendations to ensure consistency between the technical baseline requirements, baseline design, and the as-constructed Access Roads. Recommendations for resolving discrepancies between the as-constructed system, the technical baseline requirements, and the baseline design are included in this report. Cost and Schedule estimates are provided for all recommended modifications. This report does not address items which do not meet current safety or code requirements. These items are identified to the CMO and immediate action is taken to correct the situation. The report does identify safety and code items for which the A/E is recommending improvements. The recommended improvements will exceed the minimum requirements of applicable code and safety guide lines. These recommendations are intended to improve and enhance the operation and maintenance of the facility

  19. Enhanced Role Based Access Control Mechanism for Electronic Examination System

    Adebukola Onashoga

    2014-02-01

    Full Text Available Over the years, e-learning and e-examination has become standard in many institutions of higher learning. It has been observed that examination questions and results can be easily intercepted by invalid users, thus the security of resources shared among valid users is not guaranteed. In order to solve these problems as it relates to access control, a Role based Examination System (RBES was designed, developed and evaluated. RBES attempted to solve the security issue by the combination of two authentication techniques: text-based authentication and graphical password authentication. The Text-based authentication utilizes two text-based parameters namely the username and password. The graphical password authentication makes use of a finite set of controls (RBES chooses radio buttons which are identified by numbers. These numbers constitute the password used for graphical authentication. To improve on resource sharing among users in the examination system, RBES proposes role management (role creation, role update, role removal and user management (user creation, user update and user removal. The developed system made use of asp.net, C#, IIS server, WAMP server, Mysql and other tools for its development. RBES was tested by some legitimate and illegitimate users and the performance of the system was found to be satisfactory, hence RBES shows an efficient and reliable scheme that can be deployed in any examination or e-learning system. Finally the potential threats to the system were modeled and the use of weak passwords was found to be the most likely threat the system could be vulnerable to.

  20. 78 FR 51810 - Twenty-Fourth Meeting: RTCA Special Committee 224, Airport Security Access Control Systems

    2013-08-21

    ... Security Access Control Systems AGENCY: Federal Aviation Administration (FAA), U.S. Department of Transportation (DOT). ACTION: Meeting Notice of RTCA Special Committee 224, Airport Security Access Control... RTCA Special Committee 224, Airport Security Access Control Systems. DATES: The meeting will be held...

  1. Fetal lung volume measurement by MRI with high-speed imaging systems

    Osada, Hisao; Kaku, Kenshi [Chiba Univ. (Japan). Hospital

    2002-08-01

    Although ultrasonography is widely used for fetal morphologic observation, magnetic resonance imaging (MRI) has gained popularity as a new prenatal diagnostic method with recent introduction of high-speed imaging systems. Infants with lung hypoplasia affecting respiratory function require intensive management starting immediately after birth. Therefore, accurate prenatal differential diagnosis and severity evaluation are extremely important for these fetuses. The aim of this study is to measure fetal lung volume using a computer-based, three-dimensional MRI imaging system and to evaluate the possibility of clinical applications of this procedure. A total of 96 fetuses were evaluated, all were morphologically abnormal, and MRI was done for advanced assessment from 24 to 39 weeks gestation. Three-directional views of fetal chest were imaged by Signa Horizon, 1.5 Tesla, version 5.6 (General Electronics) with the following conditions; coil: TORSO coil, sequence: SSFSE (single shot fast spin echo), slice thickness: 5 mm, and imaging speed: 2 seconds/slice. To calculate the lung volume and create three-dimensional image, the lung area in each slice was traced out, then multiplied using computer image processing. Simultaneously, the volumes of all slices were summed to give the volume of each lung. Linear regression analysis and analysis of covariance (ANCOVA) were used for statistical analyses. In all cases, clear images were obtained, and were adequate for three-dimensional evaluation of the fetal lung. Thirty-five fetuses had poor outcomes, such as intrauterine fetal death, neonatal death, and intensive respiratory care. Regression lines of lung volume versus gestational week were calculated for these fetuses with poor outcome and 61 other fetuses with good outcome. ANCOVA, with gestational week as a covariant, revealed a significant intergroup difference in the lung volume (p<0.001). Similarly, regression lines of lung volume versus fetal body weight estimated by

  2. Fetal lung volume measurement by MRI with high-speed imaging systems

    Although ultrasonography is widely used for fetal morphologic observation, magnetic resonance imaging (MRI) has gained popularity as a new prenatal diagnostic method with recent introduction of high-speed imaging systems. Infants with lung hypoplasia affecting respiratory function require intensive management starting immediately after birth. Therefore, accurate prenatal differential diagnosis and severity evaluation are extremely important for these fetuses. The aim of this study is to measure fetal lung volume using a computer-based, three-dimensional MRI imaging system and to evaluate the possibility of clinical applications of this procedure. A total of 96 fetuses were evaluated, all were morphologically abnormal, and MRI was done for advanced assessment from 24 to 39 weeks gestation. Three-directional views of fetal chest were imaged by Signa Horizon, 1.5 Tesla, version 5.6 (General Electronics) with the following conditions; coil: TORSO coil, sequence: SSFSE (single shot fast spin echo), slice thickness: 5 mm, and imaging speed: 2 seconds/slice. To calculate the lung volume and create three-dimensional image, the lung area in each slice was traced out, then multiplied using computer image processing. Simultaneously, the volumes of all slices were summed to give the volume of each lung. Linear regression analysis and analysis of covariance (ANCOVA) were used for statistical analyses. In all cases, clear images were obtained, and were adequate for three-dimensional evaluation of the fetal lung. Thirty-five fetuses had poor outcomes, such as intrauterine fetal death, neonatal death, and intensive respiratory care. Regression lines of lung volume versus gestational week were calculated for these fetuses with poor outcome and 61 other fetuses with good outcome. ANCOVA, with gestational week as a covariant, revealed a significant intergroup difference in the lung volume (p<0.001). Similarly, regression lines of lung volume versus fetal body weight estimated by

  3. Power System Trade Studies for the Lunar Surface Access Module

    Kohout, Lisa, L.

    2008-01-01

    A Lunar Lander Preparatory Study (LLPS) was undertaken for NASA's Lunar Lander Pre-Project in 2006 to explore a wide breadth of conceptual lunar lander designs. Civil servant teams from nearly every NASA center responded with dozens of innovative designs that addressed one or more specific lander technical challenges. Although none of the conceptual lander designs sought to solve every technical design issue, each added significantly to the technical database available to the Lunar Lander Project Office as it began operations in 2007. As part of the LLPS, a first order analysis was performed to identify candidate power systems for the ascent and descent stages of the Lunar Surface Access Module (LSAM). A power profile by mission phase was established based on LSAM subsystem power requirements. Using this power profile, battery and fuel cell systems were modeled to determine overall mass and volume. Fuel cell systems were chosen for both the descent and ascent stages due to their low mass. While fuel cells looked promising based on these initial results, several areas have been identified for further investigation in subsequent studies, including the identification and incorporation of peak power requirements into the analysis, refinement of the fuel cell models to improve fidelity and incorporate ongoing technology developments, and broadening the study to include solar power.

  4. Real-time 3-dimensional virtual reality navigation system with open MRI for breast-conserving surgery

    We report here the early experiences using a real-time three-dimensional (3D) virtual reality navigation system with open magnetic resonance imaging (MRI) for breast-conserving surgery (BCS). Two patients with a non-palpable MRI-detected breast tumor underwent BCS under the guidance of the navigation system. An initial MRI for the breast tumor using skin-affixed markers was performed immediately prior to excision. A percutaneous intramammary dye marker was applied to delineate an excision line, and the computer software '3D Slicer' generated a real-time 3D virtual reality model of the tumor and the puncture needle in the breast. Under guidance by the navigation system, marking procedures were performed without any difficulties. Fiducial registration errors were 3.00 mm for patient no.1, and 4.07 mm for patient no.2. The real-time 3D virtual reality navigation system with open MRI is feasible for safe and accurate excision of non-palpable MRI-detected breast tumors. (author)

  5. Chest MRI

    Nuclear magnetic resonance - chest; Magnetic resonance imaging - chest; NMR - chest; MRI of the thorax; Thoracic MRI ... healthy enough to filter the contrast. During the MRI, the person who operates the machine will watch ...

  6. MRI screening for breast cancer in women at high risk; is the Australian breast MRI screening access program addressing the needs of women at high risk of breast cancer?

    Breast magnetic resonance imaging (MRI) screening of women under 50 years old at high familial risk of breast cancer was given interim funding by Medicare in 2009 on the basis that a review would be undertaken. An updated literature review has been undertaken by the Medical Services Advisory Committee but there has been no assessment of the quality of the screening or other screening outcomes. This review examines the evidence basis of breast MRI screening and how this fits within an Australian context with the purpose of informing future modifications to the provision of Medicare-funded breast MRI screening in Australia. Issues discussed will include selection of high-risk women, the options for MRI screening frequency and measuring the outcomes of screening

  7. MRI screening for breast cancer in women at high risk; is the Australian breast MRI screening access program addressing the needs of women at high risk of breast cancer?

    Schenberg, Tess [Department of Medical Oncology, Peter MacCallum Cancer Centre, Melbourne, Victoria (Australia); Familial Cancer Centre, Peter MacCallum Cancer Centre, Melbourne, Victoria (Australia); Mitchell, Gillian [Familial Cancer Centre, Peter MacCallum Cancer Centre, Melbourne, Victoria (Australia); Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, Victoria (Australia); Taylor, Donna [School of Surgery, University of Western Australia, Perth, Western Australia (Australia); Department of Radiology, Royal Perth Hospital, Perth, Western Australia (Australia); BreastScreen Western Australia, Adelaide Terrace, Perth, Western Australia (Australia); Saunders, Christobel [School of Surgery, University of Western Australia, Perth, Western Australia (Australia); Department of General Surgery, St John of God Hospital, Perth, Western Australia (Australia); Department of Medical Oncology, Peter MacCallum Cancer Centre, Melbourne, Victoria (Australia)

    2015-09-15

    Breast magnetic resonance imaging (MRI) screening of women under 50 years old at high familial risk of breast cancer was given interim funding by Medicare in 2009 on the basis that a review would be undertaken. An updated literature review has been undertaken by the Medical Services Advisory Committee but there has been no assessment of the quality of the screening or other screening outcomes. This review examines the evidence basis of breast MRI screening and how this fits within an Australian context with the purpose of informing future modifications to the provision of Medicare-funded breast MRI screening in Australia. Issues discussed will include selection of high-risk women, the options for MRI screening frequency and measuring the outcomes of screening.

  8. MRI screening for breast cancer in women at high risk; is the Australian breast MRI screening access program addressing the needs of women at high risk of breast cancer?

    Schenberg, Tess; Mitchell, Gillian; Taylor, Donna; Saunders, Christobel

    2015-09-01

    Breast magnetic resonance imaging (MRI) screening of women under 50 years old at high familial risk of breast cancer was given interim funding by Medicare in 2009 on the basis that a review would be undertaken. An updated literature review has been undertaken by the Medical Services Advisory Committee but there has been no assessment of the quality of the screening or other screening outcomes. This review examines the evidence basis of breast MRI screening and how this fits within an Australian context with the purpose of informing future modifications to the provision of Medicare-funded breast MRI screening in Australia. Issues discussed will include selection of high-risk women, the options for MRI screening frequency and measuring the outcomes of screening. PMID:26451244

  9. MRI screening for breast cancer in women at high risk; is the Australian breast MRI screening access program addressing the needs of women at high risk of breast cancer?

    Schenberg, Tess; Mitchell, Gillian; Taylor, Donna; Saunders, Christobel

    2015-01-01

    Breast magnetic resonance imaging (MRI) screening of women under 50 years old at high familial risk of breast cancer was given interim funding by Medicare in 2009 on the basis that a review would be undertaken. An updated literature review has been undertaken by the Medical Services Advisory Committee but there has been no assessment of the quality of the screening or other screening outcomes. This review examines the evidence basis of breast MRI screening and how this fits within an Australi...

  10. MRI and low back pain

    Backache - MRI; Low back pain - MRI; Lumbar pain - MRI; Back strain - MRI; Lumbar radiculopathy - MRI; Herniated intervertebral disk - MRI; Prolapsed intervertebral disk - MRI; Slipped disk - MRI; Ruptured ...

  11. SINP space physics data storage and access system

    Barinova, Vera; Kalegaev, Vladimir; Parunakian, David

    In this paper we present the system for automated data retrieval and processing developed in the the Skobeltsyn Institute of Nuclear Physics. Telemetry data files containing scientific information (e.g. charged particle fluxes) are auto-matically parsed and stored in our Oracle database immediately upon arrival. Parsed telemetry files, metadata, instrument technical information and orbital parameters are also stored. Most of the data can be accessed via our public FTP server. Users can preview the data available for time intervals and channels of interest using the web interface provided. The preview plot building software has also been developed in-house. This system has been successfully used in 2009 with the following spacecraft and instru-ments: Electron-M-Pesca at Coronas-Photon (Electrons 200KeV -4 MeV+; Protons : 4 MeV -80MeV+ ;α : 5 -24 MeV/nucleon; CNO : 6 -15MeV/nucleon), DUFIK at Tatiana-2 (electrons, infrared 600nm ¡ ¡ 700nm and ultraviolet 300nm ¡ ¡ 400nm), MSGI and SKL at Meteor-M (10 spectral channels: 0,5-12,5 µm ). The data collections are available at http://smdc.sinp.msu.ru for visual preview and download.

  12. A system for success: BMC Systems Biology, a new open access journal

    Webb Penelope A

    2007-09-01

    Full Text Available Abstract BMC Systems Biology is the first open access journal spanning the growing field of systems biology from molecules up to ecosystems. The journal has launched as more and more institutes are founded that are similarly dedicated to this new approach. BMC Systems Biology builds on the ongoing success of the BMC series, providing a venue for all sound research in the systems-level analysis of biology.

  13. A system for success: BMC Systems Biology, a new open access journal

    Webb Penelope A; Hodgkinson Matt J

    2007-01-01

    Abstract BMC Systems Biology is the first open access journal spanning the growing field of systems biology from molecules up to ecosystems. The journal has launched as more and more institutes are founded that are similarly dedicated to this new approach. BMC Systems Biology builds on the ongoing success of the BMC series, providing a venue for all sound research in the systems-level analysis of biology.

  14. Whole-body MRI in children with Langerhans cell histiocytosis for the evaluation of the skeletal system

    Purpose: the usefulness of whole-body MRI (WB-MRI) for the detection of skeletal lesions in patients with Langerhans cell histiocytosis should be documented on the basis of case presentations. Materials and methods: in six patients with histologically proven Langerhans cell histiocytosis, 14 WB-MRI examinations were performed to evaluate the skeletal system within disease staging (6 primary, 8 follow-up examinations). The examinations were performed on a 1.5 Tesla, 32-channel whole-body scanner. The examination protocol consisted of T1-weighted and STIR sequences in coronal and sagittal orientation. For comparison, radiographs of the initial skeletal lesions and those that were additionally detected on WB-MRI were available. Results: in 4 patients no additional skeletal lesions were found on WB-MRI besides the initial lesion leading to the diagnosis of unifocal single system disease. In 2 patients WB-MRI was able to identify additional skeletal lesions. In a 5 1/2 year-old boy with the primary lesion located in the cervical spine, a second lesion was detected in the lumbar spine on the initial scan and in the skull and proximal femur during follow-up examination. In a 12 year-old girl with a primary lesion of the thoracic spine, WB-MRI diagnosed additional lesions in the pelvic bone and the tibia. In both patients the diagnosis of multifocal skeletal involvement led to chemotherapy. During follow-up examination, the healing response under therapy could be demonstrated. Comparison with conventional imaging showed that especially lesions located in the spine or the pelvis were not detectable on radiographs even when knowing the MR results. (orig.)

  15. A CAD system for assessment of MRI findings to track the progression of multiple sclerosis

    Wong, Alexis; Gertych, Arkadiusz; Zee, Chi-Shing; Guo, Bing; Liu, Brent J.

    2007-03-01

    Multiple sclerosis (MS) is a progressive neurological disease affecting myelin pathways. MRI has become the medical imaging study of choice both for the diagnosis and for the follow-up and monitoring of multiple sclerosis. The progression of the disease is variable, and requires routine follow-up to document disease exacerbation, improvement, or stability of the characteristic MS lesions or plaques. The difficulties with using MRI as a monitoring tool are the significant quantities of time needed by the radiologist to actually measure the size of the lesions, and the poor reproducibility of these manual measurements. A CAD system for automatic image analysis improves clinical efficiency and standardizes the lesion measurements. Multiple sclerosis is a disease well suited for automated analysis. The segmentation algorithm devised classifies normal and abnormal brain structures and measures the volume of multiple sclerosis lesions using fuzzy c-means clustering with incorporated spatial (sFCM) information. First, an intracranial structures mask in T1 image data is localized and then superimposed in FLAIR image data. Next, MS lesions are identified by sFCM and quantified within a predefined volume. The initial validation process confirms a satisfactory comparison of automatic segmentation to manual outline by a neuroradiologist and the results will be presented.

  16. MRI in psychiatry

    Mulert, Christoph [UKE, Hamburg (Germany). Psychiatry Neuroimaging Branch; Shenton, Martha E. (ed.) [Harvard Medical School, Boston, MA (United States). Dept. of Psychiatry and Radiology

    2014-07-01

    This is the first comprehensive textbook on the use of MRI in psychiatry covering imaging techniques, brain systems and a review of findings in different psychiatric disorders. The book is divided into three sections, the first of which covers in detail all the major MRI-based methodological approaches available today, including fMRI, EEG-fMRI, DTI, and MR spectroscopy. In addition, the role of MRI in imaging genetics and combined brain stimulation and imaging is carefully explained. The second section provides an overview of the different brain systems that are relevant for psychiatric disorders, including the systems for perception, emotion, cognition, and reward. The final part of the book presents the MRI findings that are obtained in all the major psychiatric disorders using the previously discussed techniques. Numerous carefully chosen images support the informative text, making this an ideal reference work for all practitioners and trainees with an interest in this flourishing field.

  17. Combining optogenetic stimulation and fMRI to validate a multivariate dynamical systems model for estimating causal brain interactions.

    Ryali, Srikanth; Shih, Yen-Yu Ian; Chen, Tianwen; Kochalka, John; Albaugh, Daniel; Fang, Zhongnan; Supekar, Kaustubh; Lee, Jin Hyung; Menon, Vinod

    2016-05-15

    State-space multivariate dynamical systems (MDS) (Ryali et al. 2011) and other causal estimation models are being increasingly used to identify directed functional interactions between brain regions. However, the validity and accuracy of such methods are poorly understood. Performance evaluation based on computer simulations of small artificial causal networks can address this problem to some extent, but they often involve simplifying assumptions that reduce biological validity of the resulting data. Here, we use a novel approach taking advantage of recently developed optogenetic fMRI (ofMRI) techniques to selectively stimulate brain regions while simultaneously recording high-resolution whole-brain fMRI data. ofMRI allows for a more direct investigation of causal influences from the stimulated site to brain regions activated downstream and is therefore ideal for evaluating causal estimation methods in vivo. We used ofMRI to investigate whether MDS models for fMRI can accurately estimate causal functional interactions between brain regions. Two cohorts of ofMRI data were acquired, one at Stanford University and the University of California Los Angeles (Cohort 1) and the other at the University of North Carolina Chapel Hill (Cohort 2). In each cohort, optical stimulation was delivered to the right primary motor cortex (M1). General linear model analysis revealed prominent downstream thalamic activation in Cohort 1, and caudate-putamen (CPu) activation in Cohort 2. MDS accurately estimated causal interactions from M1 to thalamus and from M1 to CPu in Cohort 1 and Cohort 2, respectively. As predicted, no causal influences were found in the reverse direction. Additional control analyses demonstrated the specificity of causal interactions between stimulated and target sites. Our findings suggest that MDS state-space models can accurately and reliably estimate causal interactions in ofMRI data and further validate their use for estimating causal interactions in fMRI

  18. Universal remote access infrastructure for embedded systems; Universelle Fernzugriff-Infrastruktur fuer eingebettete Systeme

    Jazdi, N. [Stuttgart Univ. (Germany). Inst. fuer Automatisierungs- und Softwaretechnik

    2005-07-01

    This article describes a flexible and extensible infrastructure for applying Web-Technologies to embedded systems.The presented approach develops a Three-level-Architecture consisting of the embedded system, the universal Remote-Access-Server and the Remote-Access-Client. A system-spanning general interface allows the binding of embedded systems in order to access their process data. Additionally, this procedure facilitates a flexible processing of the device data, so that it is ready to be used by different control devices. To ensure flexibility - connecting different devices on the one side and providing information for different clients like PC, PDA or mobile phone on the other side - a new XML-based description language (Service Description Markup Language - SDML) is introduced. The SDML documents contain information about connected embedded systems, reusable device data and the presentation policies for different clients. These documents are specifically created for each device. Applying the suggested procedure, different embedded systems can be connected to the Internet with minimum hardware and software requirements/costs. Software components of the Remote-Access-Server, once developed, can be used and applied to various devices which lead to a reduction of the development costs. The user can use an ordinary web browser to communicate with the devices and does not need to install any additional software on his local computer. (orig.) (orig.)

  19. Efficiency of unenhanced MRI in the diagnosis of acute appendicitis: Comparison with Alvarado scoring system and histopathological results

    Inci, Ercan, E-mail: ercan_inci@mynet.com [Department of Radiology, Istanbul Bakirkoy Dr. Sadi Konuk Training and Research Hospital, Incirli-Bakirkoy, Istanbul (Turkey); Hocaoglu, Elif; Aydin, Sibel; Palabiyik, Figen; Cimilli, Tan [Department of Radiology, Istanbul Bakirkoy Dr. Sadi Konuk Training and Research Hospital, Incirli-Bakirkoy, Istanbul (Turkey); Turhan, Ahmet Nuray; Ayguen, Ersan [Department of Surgery, Istanbul Bakirkoy Dr. Sadi Konuk Training and Research Hospital, Istanbul (Turkey)

    2011-11-15

    Purpose: The purpose of this study was to assess the diagnostic value of unenhanced magnetic resonance imaging (MRI) in the diagnosis of acute appendicitis and compare with Alvarado scores and histopathological results. Materials and methods: The study included 85 consecutive patients (mean age, 26.5 {+-} 11.3 years) who were clinically suspected of having acute appendicitis. Each patients Alvarado scores were recorded and unenhanced MRI was performed, consisting of T1-weighted, T2-weighted and fat-suppressed T2-weighted fast spin-echo sequences. The MR images were prospectively reviewed in consensus for the presence of acute appendicitis by two radiologists who were blinded to the results of the Alvarado scores. The study population were divided into three subgroups based on the MRI findings: Group I: definitely not appendicitis, Group II: probably appendicitis, Group III: definitely appendicitis. All patients were divided into two subgroups according to Alvarado scores as Group A (low: 1-6), and Group B (high: 7-10). MR findings were compared with Alvarado scores and histopathological findings. Results: Sixty-six (77.6%) of the 85 patients with clinically suspected acute appendicitis, had undergone surgery. The diagnosis of appendicitis could be correctly achieved with MRI in 55 (83.3%) of 57 (86.4%) patients with histopathologically proven acute appendicitis. The sensitivity, specificity, positive predictive value and negative predictive value of MRI examination and Alvarado scoring system in the diagnosis of acute appendicitis were 96.49%, 66.67%, 94.83%, 75.0% and 84.21%, 66.67%, 94.12%, 40.0%, respectively. Conclusions: MRI is a valuable technique for detecting acute appendicitis even in the cases with low Alvarado scores. To increase the diagnostic accuracy and preventing unnecessary laparotomies for suspected appendicitis, shorter and cheaper unenhanced basic MRI may be performed.

  20. Efficiency of unenhanced MRI in the diagnosis of acute appendicitis: Comparison with Alvarado scoring system and histopathological results

    Purpose: The purpose of this study was to assess the diagnostic value of unenhanced magnetic resonance imaging (MRI) in the diagnosis of acute appendicitis and compare with Alvarado scores and histopathological results. Materials and methods: The study included 85 consecutive patients (mean age, 26.5 ± 11.3 years) who were clinically suspected of having acute appendicitis. Each patients Alvarado scores were recorded and unenhanced MRI was performed, consisting of T1-weighted, T2-weighted and fat-suppressed T2-weighted fast spin-echo sequences. The MR images were prospectively reviewed in consensus for the presence of acute appendicitis by two radiologists who were blinded to the results of the Alvarado scores. The study population were divided into three subgroups based on the MRI findings: Group I: definitely not appendicitis, Group II: probably appendicitis, Group III: definitely appendicitis. All patients were divided into two subgroups according to Alvarado scores as Group A (low: 1-6), and Group B (high: 7-10). MR findings were compared with Alvarado scores and histopathological findings. Results: Sixty-six (77.6%) of the 85 patients with clinically suspected acute appendicitis, had undergone surgery. The diagnosis of appendicitis could be correctly achieved with MRI in 55 (83.3%) of 57 (86.4%) patients with histopathologically proven acute appendicitis. The sensitivity, specificity, positive predictive value and negative predictive value of MRI examination and Alvarado scoring system in the diagnosis of acute appendicitis were 96.49%, 66.67%, 94.83%, 75.0% and 84.21%, 66.67%, 94.12%, 40.0%, respectively. Conclusions: MRI is a valuable technique for detecting acute appendicitis even in the cases with low Alvarado scores. To increase the diagnostic accuracy and preventing unnecessary laparotomies for suspected appendicitis, shorter and cheaper unenhanced basic MRI may be performed.

  1. Database Security System for Applying Sophisticated Access Control via Database Firewall Server

    Eun-Ae Cho; Chang-Joo Moon; Dae-Ha Park; Kang-Bin Yim

    2014-01-01

    Database security, privacy, access control, database firewall, data break masking Recently, information leakage incidents have occurred due to database security vulnerabilities. The administrators in the traditional database access control methods grant simple permissions to users for accessing database objects. Even though they tried to apply more strict permissions in recent database systems, it was difficult to properly adopt sophisticated access control policies to commercial databases...

  2. The Time Between: Continuously-defined accessibility functions for schedule-based transportation systems

    Paul Anderson; Andrew Owen; David Levinson

    2012-01-01

    Accessibility is traditionally considered to be a property of a point or region in space, and to be invariant over time (or at least over some computationally convenient time interval). How- ever, a locations accessibility can vary over time on a wide range of scales. This temporal variation is especially significant for schedule-based transportation systems. Current measures of accessibility generally reflect the accessibility only at points in time corresponding to the departures of one or ...

  3. Simultaneous fMRI-PET of the opioidergic pain system in human brain

    Wey, Hsiao-Ying; Catana, Ciprian; Hooker, Jacob M;

    2014-01-01

    MRI and PET provide complementary information for studying brain function. While the potential use of simultaneous MRI/PET for clinical diagnostic and disease staging has been demonstrated recently; the biological relevance of concurrent functional MRI-PET brain imaging to dissect neurochemically...... and striatum related to pain processing, while modality specific brain networks were also found. Co-localized fMRI and PET signal changes in the thalamus were positively correlated suggesting that pain-induced changes in opioid neurotransmission contribute a significant component of the fMRI signal...... change in this region. Simultaneous fMRI-PET provides unique opportunities allowing us to relate specific neurochemical events to functional hemodynamic activation and to investigate the impacts of neurotransmission on neurovascular coupling of the human brain in vivo....

  4. CT and MRI findings of central nervous system complications of leukemia

    Objective: To evaluate the CT and MRI findings and their diagnostic value of central nervous system complications of leukemia (CNSCL). Methods: The CT and MRI findings of 18 adult patients with CNSCL proved by clinical features or pathology were retrospectively analyzed. Among 18 cases, 7 were acute lymphocytic leukemia, 10 acute non-lymphocytic leukemia and 1 chronic myelomonocytic leukemia. Eleven cases underwent plain CT scan with one of them also receiving contrast-enhanced CT scan enhancement, 16 cases underwent plain MR scan with 11 of them receiving contrast-enhanced MR scan. Results: Intracranial lesions in 14 cases: (1) intracranial hemorrhage was found in 7 cases, including intracerebral hematoma in 4 cases, micro-haemorrhage in 2 cases, and intracerebral hematoma accompanying by multiple intracerebral micro-haemorrhage foci in 1 case. All cases with intracerebral hematoma showed multiple lesions, which demonstrated high-density on CT images, and low or mixed signal on T1WI, high- oi intermediate signal with low-signal rim on T2WI and ring enhancement or no evident enhancement. Micro- haemorrhage manifested as multiple mini-mottling and strip hypointense foci on susceptibility weighted imaging, on which the detection rate of micro-haemorrhage foci was much higher than that on CT and other sequences of MRI. Among the 7 cases, one also had cerebral infarction and one subarachnoid hemorrhage. (2) Intracranial mass was found in 5 cases, among which two appeared as masses under or bestride cranium in the left frontal region with hypointensity on T1WI, mixed signal on T2WI, strong homogeneous enhancement and dual tail sign; one showed a mass in saddle area, with high density on CT, slightly low signal on T1WI, high signal on T2WI and heterogeneous enhancement, one case displayed a mass near lateral ventricle with iso-intensity on T1WI and T2WI and strong homogeneous enhancement; and one case manifested as cystic mass in the left fronto-apical lobe, with thick

  5. Presidential Management Fellows (PMF) Talent Acquisition System, PMF-TAS (ACCESS CONTROLLED)

    Office of Personnel Management — Application and Assessment system for Presidential Management Fellows (PMF) and PMF Science, Technology, Engineering, and Math (STEM) programs. This sytem is access...

  6. Ultra-sensitive molecular MRI of cerebrovascular cell activation enables early detection of chronic central nervous system disorders

    Since endothelial cells can be targeted by large contrast-carrying particles, molecular imaging of cerebrovascular cell activation is highly promising to evaluate the underlying inflammation of the central nervous system (CNS). In this study, we aimed to demonstrate that molecular magnetic resonance imaging (MRI) of cerebrovascular cell activation can reveal CNS disorders in the absence of visible lesions and symptoms. To this aim, we optimized contrast carrying particles targeting vascular cell adhesion molecule-1 and MRI protocols through both in vitro and in vivo experiments. Although, pre-contrast MRI images failed to reveal the ongoing pathology, contrast-enhanced MRI revealed hypoperfusion-triggered CNS injury in vascular dementia, unmasked amyloid-induced cerebrovascular activation in Alzheimer's disease and allowed monitoring of disease activity during experimental autoimmune encephalomyelitis. Moreover, contrast-enhanced MRI revealed the cerebrovascular cell activation associated with known risk factors of CNS disorders such as peripheral inflammation, ethanol consumption, hyperglycemia and aging. By providing a dramatically higher sensitivity than previously reported methods and molecular contrast agents, the technology described in the present study opens new avenues of investigation in the field of neuro-inflammation. (authors)

  7. A United Access Control Model for Systems in Collaborative Commerce

    Ruo-Fei Han; Hou-Xiang Wang; Qian Xiao; Xiao-Pei Jing; Hui Li

    2009-01-01

    The latest researches on access control model are dramatically different from conventional ones. Nowadays, most attention is paid to accessing across organizational boundaries. So, how to identify the applicant and determine authorization with limited information; how to express and exchange control rules expediently; how to protect confidential information and enhance collaboration simultaneously, are the most concerned problems. However, for large commercial organizations, a fine management...

  8. 48 CFR 504.602-71 - Federal Procurement Data System-Public access to data.

    2010-10-01

    ... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Federal Procurement Data System-Public access to data. 504.602-71 Section 504.602-71 Federal Acquisition Regulations System GENERAL SERVICES ADMINISTRATION GENERAL ADMINISTRATIVE MATTERS Contract Reporting 504.602-71 Federal Procurement Data System—Public access to data....

  9. From System Expansion to System Contraction: Access to Higher Education in Poland

    Kwiek, Marek

    2013-01-01

    Access to higher education in Poland is changing due to the demography of smaller cohorts of potential students. Following a demand-driven educational expansion after the collapse of communism in 1989, the higher education system is now contracting. Such expansion/contraction and growth/decline in European higher education has rarely been…

  10. Magnetic Resonance Imaging (MRI) -- Head

    Full Text Available ... or cause problems during an MRI exam. Nephrogenic systemic fibrosis is currently a recognized, but rare, complication ... Tumor Treatment Magnetic Resonance Imaging (MRI) Safety Alzheimer's Disease Head Injury Brain Tumors Images related to Magnetic ...