WorldWideScience

Sample records for performing onboard diagnostic

  1. An Integrated Architecture for On-Board Aircraft Engine Performance Trend Monitoring and Gas Path Fault Diagnostics

    Science.gov (United States)

    Simon, Donald L.

    2010-01-01

    Aircraft engine performance trend monitoring and gas path fault diagnostics are closely related technologies that assist operators in managing the health of their gas turbine engine assets. Trend monitoring is the process of monitoring the gradual performance change that an aircraft engine will naturally incur over time due to turbomachinery deterioration, while gas path diagnostics is the process of detecting and isolating the occurrence of any faults impacting engine flow-path performance. Today, performance trend monitoring and gas path fault diagnostic functions are performed by a combination of on-board and off-board strategies. On-board engine control computers contain logic that monitors for anomalous engine operation in real-time. Off-board ground stations are used to conduct fleet-wide engine trend monitoring and fault diagnostics based on data collected from each engine each flight. Continuing advances in avionics are enabling the migration of portions of the ground-based functionality on-board, giving rise to more sophisticated on-board engine health management capabilities. This paper reviews the conventional engine performance trend monitoring and gas path fault diagnostic architecture commonly applied today, and presents a proposed enhanced on-board architecture for future applications. The enhanced architecture gains real-time access to an expanded quantity of engine parameters, and provides advanced on-board model-based estimation capabilities. The benefits of the enhanced architecture include the real-time continuous monitoring of engine health, the early diagnosis of fault conditions, and the estimation of unmeasured engine performance parameters. A future vision to advance the enhanced architecture is also presented and discussed

  2. Rapid Diagnostics of Onboard Sequences

    Science.gov (United States)

    Starbird, Thomas W.; Morris, John R.; Shams, Khawaja S.; Maimone, Mark W.

    2012-01-01

    Keeping track of sequences onboard a spacecraft is challenging. When reviewing Event Verification Records (EVRs) of sequence executions on the Mars Exploration Rover (MER), operators often found themselves wondering which version of a named sequence the EVR corresponded to. The lack of this information drastically impacts the operators diagnostic capabilities as well as their situational awareness with respect to the commands the spacecraft has executed, since the EVRs do not provide argument values or explanatory comments. Having this information immediately available can be instrumental in diagnosing critical events and can significantly enhance the overall safety of the spacecraft. This software provides auditing capability that can eliminate that uncertainty while diagnosing critical conditions. Furthermore, the Restful interface provides a simple way for sequencing tools to automatically retrieve binary compiled sequence SCMFs (Space Command Message Files) on demand. It also enables developers to change the underlying database, while maintaining the same interface to the existing applications. The logging capabilities are also beneficial to operators when they are trying to recall how they solved a similar problem many days ago: this software enables automatic recovery of SCMF and RML (Robot Markup Language) sequence files directly from the command EVRs, eliminating the need for people to find and validate the corresponding sequences. To address the lack of auditing capability for sequences onboard a spacecraft during earlier missions, extensive logging support was added on the Mars Science Laboratory (MSL) sequencing server. This server is responsible for generating all MSL binary SCMFs from RML input sequences. The sequencing server logs every SCMF it generates into a MySQL database, as well as the high-level RML file and dictionary name inputs used to create the SCMF. The SCMF is then indexed by a hash value that is automatically included in all command

  3. USING THE INFORMATION OF ON-BOARD DIAGNOSTIC SYSTEMS IN DETERMINING THE TECHNICAL STATE OF THE LOCOMOTIVE

    Directory of Open Access Journals (Sweden)

    B. Ye. Bodnar

    2008-12-01

    Full Text Available The issues of increase of efficiency of information processing by оn-board systems of diagnostics of locomotives are considered. The examples of information processing by the on-board system of diagnostics of electric locomotives DE1 are presented. The suggestions on improvement of systematization and processing of information by on-board systems of diagnostics are given.

  4. 40 CFR 85.2222 - On-board diagnostic test procedures.

    Science.gov (United States)

    2010-07-01

    ... on-board diagnostic systems on 1996 and newer light-duty vehicles and light-duty trucks shall consist... the unset readiness code(s) in question may be issued a passing certificate without being required to... lit malfunction indicator light (MIL) must be failed, though setting the unset readiness flags in...

  5. Comparison of MODIS and VIIRS On-board Blackbody Performance

    Science.gov (United States)

    Xiong, Jack; Butler, Jim; Wu, Aisheng; Chiang, Vincent; McIntire, Jeff; Oudari, Hassan

    2012-01-01

    MODIS has 16 thermal emissive bands (TEBs), covering wavelengths from 3.7 to 14.4 microns. MODIS TEBs are calibrated on-orbit by a v-grooved blackbody (BB) on a scan-by-scan basis. The BB temperatures are measured by a set of 12 thennistors. As expected, the BB temperature uncertainty and stability have direct impact on the quality of TEB calibration and, therefore, the quality of the science products derived from TEB observations. Since launch, Terra and Aqua MODIS have successfully operated for more than 12 and 10 years, respectively. Their on-board BB performance has been satisfactory in meeting the TEB calibration requirements. The first VIIRS, launched on-board the Suomi NPP spacecraft on October 28, 2011, has successfully completed its initial Intensive Calibration and Validation (ICV) phase. VIIRS has 7 thermal emissive bands (TEBs), covering wavelengths from 3.7 to 12.4 microns. Designed with strong MODIS heritage, VIIRS uses a similar BB for its TEB calibration. Like MODIS, VIIRS BB is nominally controlled at a pre-determined temperature (set point). Periodically, a BB Warm-Up and Cool-Down (WUCD) operation is performed, during which the BB temperatures vary from instrument ambient (temperature) to 315K. This paper examines NPP VIIRS BB on-orbit performance. It focuses on its BB temperature scan-to-scan variations at nominally controlled temperature as well as during its WUCD operation and their impact on TEB calibration uncertainty. Comparisons of VIIRS (NPP) and MODIS (Terra and Aqua) BB on-orbit performance and lessons learned for future improvements are also presented in this paper.

  6. Fault diagnostics for turbo-shaft engine sensors based on a simplified on-board model.

    Science.gov (United States)

    Lu, Feng; Huang, Jinquan; Xing, Yaodong

    2012-01-01

    Combining a simplified on-board turbo-shaft model with sensor fault diagnostic logic, a model-based sensor fault diagnosis method is proposed. The existing fault diagnosis method for turbo-shaft engine key sensors is mainly based on a double redundancies technique, and this can't be satisfied in some occasions as lack of judgment. The simplified on-board model provides the analytical third channel against which the dual channel measurements are compared, while the hardware redundancy will increase the structure complexity and weight. The simplified turbo-shaft model contains the gas generator model and the power turbine model with loads, this is built up via dynamic parameters method. Sensor fault detection, diagnosis (FDD) logic is designed, and two types of sensor failures, such as the step faults and the drift faults, are simulated. When the discrepancy among the triplex channels exceeds a tolerance level, the fault diagnosis logic determines the cause of the difference. Through this approach, the sensor fault diagnosis system achieves the objectives of anomaly detection, sensor fault diagnosis and redundancy recovery. Finally, experiments on this method are carried out on a turbo-shaft engine, and two types of faults under different channel combinations are presented. The experimental results show that the proposed method for sensor fault diagnostics is efficient.

  7. Fault Diagnostics for Turbo-Shaft Engine Sensors Based on a Simplified On-Board Model

    Directory of Open Access Journals (Sweden)

    Yaodong Xing

    2012-08-01

    Full Text Available Combining a simplified on-board turbo-shaft model with sensor fault diagnostic logic, a model-based sensor fault diagnosis method is proposed. The existing fault diagnosis method for turbo-shaft engine key sensors is mainly based on a double redundancies technique, and this can’t be satisfied in some occasions as lack of judgment. The simplified on-board model provides the analytical third channel against which the dual channel measurements are compared, while the hardware redundancy will increase the structure complexity and weight. The simplified turbo-shaft model contains the gas generator model and the power turbine model with loads, this is built up via dynamic parameters method. Sensor fault detection, diagnosis (FDD logic is designed, and two types of sensor failures, such as the step faults and the drift faults, are simulated. When the discrepancy among the triplex channels exceeds a tolerance level, the fault diagnosis logic determines the cause of the difference. Through this approach, the sensor fault diagnosis system achieves the objectives of anomaly detection, sensor fault diagnosis and redundancy recovery. Finally, experiments on this method are carried out on a turbo-shaft engine, and two types of faults under different channel combinations are presented. The experimental results show that the proposed method for sensor fault diagnostics is efficient.

  8. On-Board Particulate Filter Failure Prevention and Failure Diagnostics Using Radio Frequency Sensing

    Energy Technology Data Exchange (ETDEWEB)

    Sappok, Alex [Filter Sensing Technologies; Ragaller, Paul [Filter Sensing Technologies; Herman, Andrew [CTS Corporation; Bromberg, L. [Massachusetts Institute of Technology (MIT); Prikhodko, Vitaly Y [ORNL; Parks, II, James E [ORNL; Storey, John Morse [ORNL

    2017-01-01

    The increasing use of diesel and gasoline particulate filters requires advanced on-board diagnostics (OBD) to prevent and detect filter failures and malfunctions. Early detection of upstream (engine-out) malfunctions is paramount to preventing irreversible damage to downstream aftertreatment system components. Such early detection can mitigate the failure of the particulate filter resulting in the escape of emissions exceeding permissible limits and extend the component life. However, despite best efforts at early detection and filter failure prevention, the OBD system must also be able to detect filter failures when they occur. In this study, radio frequency (RF) sensors were used to directly monitor the particulate filter state of health for both gasoline particulate filter (GPF) and diesel particulate filter (DPF) applications. The testing included controlled engine dynamometer evaluations, which characterized soot slip from various filter failure modes, as well as on-road fleet vehicle tests. The results show a high sensitivity to detect conditions resulting in soot leakage from the particulate filter, as well as potential for direct detection of structural failures including internal cracks and melted regions within the filter media itself. Furthermore, the measurements demonstrate, for the first time, the capability to employ a direct and continuous monitor of particulate filter diagnostics to both prevent and detect potential failure conditions in the field.

  9. Thermal Imaging Performance of TIR Onboard the Hayabusa2 Spacecraft

    Science.gov (United States)

    Arai, Takehiko; Nakamura, Tomoki; Tanaka, Satoshi; Demura, Hirohide; Ogawa, Yoshiko; Sakatani, Naoya; Horikawa, Yamato; Senshu, Hiroki; Fukuhara, Tetsuya; Okada, Tatsuaki

    2017-07-01

    The thermal infrared imager (TIR) is a thermal infrared camera onboard the Hayabusa2 spacecraft. TIR will perform thermography of a C-type asteroid, 162173 Ryugu (1999 JU3), and estimate its surface physical properties, such as surface thermal emissivity ɛ , surface roughness, and thermal inertia Γ, through remote in-situ observations in 2018 and 2019. In prelaunch tests of TIR, detector calibrations and evaluations, along with imaging demonstrations, were performed. The present paper introduces the experimental results of a prelaunch test conducted using a large-aperture collimator in conjunction with TIR under atmospheric conditions. A blackbody source, controlled at constant temperature, was measured using TIR in order to construct a calibration curve for obtaining temperatures from observed digital data. As a known thermal emissivity target, a sandblasted black almite plate warmed from the back using a flexible heater was measured by TIR in order to evaluate the accuracy of the calibration curve. As an analog target of a C-type asteroid, carbonaceous chondrites (50 mm × 2 mm in thickness) were also warmed from the back and measured using TIR in order to clarify the imaging performance of TIR. The calibration curve, which was fitted by a specific model of the Planck function, allowed for conversion to the target temperature within an error of 1°C (3σ standard deviation) for the temperature range of 30 to 100°C. The observed temperature of the black almite plate was consistent with the temperature measured using K-type thermocouples, within the accuracy of temperature conversion using the calibration curve when the temperature variation exhibited a random error of 0.3 °C (1σ ) for each pixel at a target temperature of 50°C. TIR can resolve the fine surface structure of meteorites, including cracks and pits with the specified field of view of 0.051°C (328 × 248 pixels). There were spatial distributions with a temperature variation of 3°C at the setting

  10. Performance assessment of an onboard monitoring system for CMV drivers : a field operational test : research brief.

    Science.gov (United States)

    2016-11-01

    The primary goal of an onboard monitoring system (OBMS) is to enhance driver performance and safety. OBMSs are employed with the expectation that feedback provided concurrently (via flashing feedback lights in the vehicle) and cumulatively (via coach...

  11. Improving BDS Autonomous Orbit Determination Performance Using Onboard Accelerometers

    Directory of Open Access Journals (Sweden)

    QIAO Jing

    2017-05-01

    Full Text Available Autonomous orbit determination is a crucial step for GNSS development to improve GNSS vulnerability, integrity, reliability and robustness. The newly launched BeiDou (BD satellites are capable of conducting satellite to satellite tracking (SST, which can be used for autonomous orbit determination. However, using SST data only, the BD satellite system (BDS will have whole constellation rotation in the absence of absolute constraints from ground or other celestial body over time, due to various force perturbations. The perturbations can be categorized into conservative forces and non-conservative forces. The conservative forces, such as the Earth non-spherical perturbations, tidal perturbation, the solar, lunar and other third-body perturbations, can be precisely modeled with latest force models. The non-conservative forces (i.e. Solar Radiation Pressure (SRP, on the other hand, are difficult to be modeled precisely, which are the main factors affecting satellite orbit determination accuracy. In recent years, accelerometers onboard satellites have been used to directly measure the non-conservative forces for gravity recovery and atmosphere study, such as GRACE, CHAMP, and GOCE missions. This study investigates the feasibility to use accelerometers onboard BD satellites to improve BD autonomous orbit determination accuracy and service span. Using simulated BD orbit and SST data, together with the error models of existing space-borne accelerometers, the orbit determination accuracy for BD constellation is evaluated using either SST data only or SST data with accelerometers. An empirical SRP model is used to extract non-conservative forces. The simulation results show that the orbit determination accuracy using SST with accelerometers is significantly better than that with SST data only. Assuming 0.33 m random noises and decimeter level signal transponder system biases in SST data, IGSO and MEO satellites decimeter level orbit accuracy can be

  12. Advanced stellar compass - Onboard autonomous orbit determination, preliminary performance

    DEFF Research Database (Denmark)

    Betto, Maurizio; Jørgensen, John Leif; Jørgensen, Peter Siegbjørn

    2004-01-01

    and the cost of deep space missions. From past experience, it appears that navigation is the Achilles heel of deep space missions. Performed on ground, this imposes considerable constraints on the entire system and limits operations. This makes it is very expensive to execute, especially when the mission lasts...... be implemented into an ASC without degrading the attitude measurements; and (4) to identify the areas of development and consolidation. The results obtained are very encouraging....

  13. About the Big Graphs Arising when Forming the Diagnostic Models in a Reconfigurable Computing Field of Functional Monitoring and Diagnostics System of the Spacecraft Onboard Control Complex

    Directory of Open Access Journals (Sweden)

    L. V. Savkin

    2015-01-01

    Full Text Available One of the problems in implementation of the multipurpose complete systems based on the reconfigurable computing fields (RCF is the problem of optimum redistribution of logicalarithmetic resources in growing scope of functional tasks. Irrespective of complexity, all of them are transformed into an orgraph, which functional and topological structure is appropriately imposed on the RCF based, as a rule, on the field programmable gate array (FPGA.Due to limitation of the hardware configurations and functions realized by means of the switched logical blocks (SLB, the abovementioned problem becomes even more critical when there is a need, within the strictly allocated RCF fragment, to realize even more complex challenge in comparison with the problem which was solved during the previous computing step. In such cases it is possible to speak about graphs of big dimensions with respect to allocated RCF fragment.The article considers this problem through development of diagnostic algorithms to implement diagnostics and control of an onboard control complex of the spacecraft using RCF. It gives examples of big graphs arising with respect to allocated RCF fragment when forming the hardware levels of a diagnostic model, which, in this case, is any hardware-based algorithm of diagnostics in RCF.The article reviews examples of arising big graphs when forming the complicated diagnostic models due to drastic difference in formation of hardware levels on closely located RCF fragments. It also pays attention to big graphs emerging when the multichannel diagnostic models are formed.Three main ways to solve the problem of big graphs with respect to allocated RCF fragment are given. These are: splitting the graph into fragments, use of pop-up windows with relocating and memorizing intermediate values of functions of high hardware levels of diagnostic models, and deep adaptive update of diagnostic model.It is shown that the last of three ways is the most efficient

  14. 40 CFR 85.2231 - On-board diagnostic test equipment requirements.

    Science.gov (United States)

    2010-07-01

    ... PROGRAMS (CONTINUED) CONTROL OF AIR POLLUTION FROM MOBILE SOURCES Emission Control System Performance... evaluation status of supported monitors (test complete/test not complete) in Mode $01 PID $01, as well as be... have the capability to include bi-directional communication for control of the evaporative canister...

  15. New Leakage Current Particulate Matter Sensor for On-Board Diagnostics

    Directory of Open Access Journals (Sweden)

    Jiawei Wang

    2016-01-01

    Full Text Available Structure and principle of the new leakage current particulate matter (PM sensor are introduced and further study is performed on the PM sensor with the combination of numerical simulation and bench test. High voltage electrode, conductive shell, and heaters are all built-in. Based on the principle of Venturi tube and maze structure design, this sensor can detect transient PM concentrations. Internal flow field of the sensor and distribution condition of PM inside the sensor are analyzed through gas-solid two-phase flow numerical simulation. The experiment was also carried out on the whole sensor system (including mechanical and electronic circuit part and the output signals were analyzed. The results of simulation and experiment reveal the possibility of PM concentration (mass detection by the sensor.

  16. Space Station Engineering and Technology Development. Proceedings of the Panel on Program Performance and Onboard Mission Control

    Science.gov (United States)

    1985-01-01

    An ad-hoc committee was asked to review the following questions relevant to the space station program: (1) onboard maintainability and repair; (2) in-space research and technology program and facility plans; (3) solar thermodynamic research and technology development program planning; (4) program performance (cost estimating, management, and cost avoidance); (5) onboard versus ground-based mission control; and (6) technology development road maps from IOC to the growth station. The objective of these new assignments is to provide NASA with advice on ways and means for improving the content, performance, and/or effectiveness of these elements of the space station program.

  17. Final Rule for Control of Air Pollution From Motor Vehicles and New Motor Vehicle Engines; Modification of Federal Onboard Diagnostic Regulations for Light-Duty Vehicles and Light-Duty Trucks; Extension of Acceptance of California OBD

    Science.gov (United States)

    This action finalizes modifications to the federal on-board diagnostics regulations, including: harmonizing the emission levels above which a component or system is considered malfunctioning with those of the California Air Resources Board (CARB).

  18. On-Orbit Performance of the Helioseismic and Magnetic Imager Instrument onboard the Solar Dynamics Observatory

    Science.gov (United States)

    Hoeksema, J. T.; Baldner, C. S.; Bush, R. I.; Schou, J.; Scherrer, P. H.

    2018-03-01

    The Helioseismic and Magnetic Imager (HMI) instrument is a major component of NASA's Solar Dynamics Observatory (SDO) spacecraft. Since commencement of full regular science operations on 1 May 2010, HMI has operated with remarkable continuity, e.g. during the more than five years of the SDO prime mission that ended 30 September 2015, HMI collected 98.4% of all possible 45-second velocity maps; minimizing gaps in these full-disk Dopplergrams is crucial for helioseismology. HMI velocity, intensity, and magnetic-field measurements are used in numerous investigations, so understanding the quality of the data is important. This article describes the calibration measurements used to track the performance of the HMI instrument, and it details trends in important instrument parameters during the prime mission. Regular calibration sequences provide information used to improve and update the calibration of HMI data. The set-point temperature of the instrument front window and optical bench is adjusted regularly to maintain instrument focus, and changes in the temperature-control scheme have been made to improve stability in the observable quantities. The exposure time has been changed to compensate for a 20% decrease in instrument throughput. Measurements of the performance of the shutter and tuning mechanisms show that they are aging as expected and continue to perform according to specification. Parameters of the tunable optical-filter elements are regularly adjusted to account for drifts in the central wavelength. Frequent measurements of changing CCD-camera characteristics, such as gain and flat field, are used to calibrate the observations. Infrequent expected events such as eclipses, transits, and spacecraft off-points interrupt regular instrument operations and provide the opportunity to perform additional calibration. Onboard instrument anomalies are rare and seem to occur quite uniformly in time. The instrument continues to perform very well.

  19. Validation of double Langmuir probe in-orbit performance onboard a nano-satellite

    Science.gov (United States)

    Tejumola, Taiwo Raphael; Zarate Segura, Guillermo Wenceslao; Kim, Sangkyun; Khan, Arifur; Cho, Mengu

    2018-03-01

    Many plasma measurement systems have been proposed and used onboard different satellites to characterize space plasma. Most of these systems employed the technique of Langmuir probes either using the single or double probes methods. Recent growth of lean satellites has positioned it on advantage to be used for space science missions using Langmuir probes because of its simplicity and convenience. However, single Langmuir probes are not appropriate to be used on lean satellites because of their limited conducting area which leads to spacecraft charging and drift of the instrument's electrical ground during measurement. Double Langmuir probes technique can overcome this limitation, as a measurement reference in relation to the spacecraft is not required. A double Langmuir probe measurement system was designed and developed at Kyushu Institute of Technology for HORYU-IV satellite, which is a 10 kg, 30 cm cubic class lean satellite launched into Low Earth Orbit on 17th February 2016. This paper presents the on-orbit performance and validation of the double Langmuir probe measurement using actual on-orbit measured data and computer simulations.

  20. EUV high resolution imager on-board solar orbiter: optical design and detector performances

    Science.gov (United States)

    Halain, J. P.; Mazzoli, A.; Rochus, P.; Renotte, E.; Stockman, Y.; Berghmans, D.; BenMoussa, A.; Auchère, F.

    2017-11-01

    The EUV high resolution imager (HRI) channel of the Extreme Ultraviolet Imager (EUI) on-board Solar Orbiter will observe the solar atmospheric layers at 17.4 nm wavelength with a 200 km resolution. The HRI channel is based on a compact two mirrors off-axis design. The spectral selection is obtained by a multilayer coating deposited on the mirrors and by redundant Aluminum filters rejecting the visible and infrared light. The detector is a 2k x 2k array back-thinned silicon CMOS-APS with 10 μm pixel pitch, sensitive in the EUV wavelength range. Due to the instrument compactness and the constraints on the optical design, the channel performance is very sensitive to the manufacturing, alignments and settling errors. A trade-off between two optical layouts was therefore performed to select the final optical design and to improve the mirror mounts. The effect of diffraction by the filter mesh support and by the mirror diffusion has been included in the overall error budget. Manufacturing of mirror and mounts has started and will result in thermo-mechanical validation on the EUI instrument structural and thermal model (STM). Because of the limited channel entrance aperture and consequently the low input flux, the channel performance also relies on the detector EUV sensitivity, readout noise and dynamic range. Based on the characterization of a CMOS-APS back-side detector prototype, showing promising results, the EUI detector has been specified and is under development. These detectors will undergo a qualification program before being tested and integrated on the EUI instrument.

  1. Diagnostic colonoscopy: performance measurement study.

    Science.gov (United States)

    Kuznets, Naomi

    2002-07-01

    This is the fifth of a series of best practices studies undertaken by the Performance Measurement Initiative (PMI), the centerpiece of the Institute for Quality Improvement (IQI), a not-for-profit quality improvement subsidiary of the Accreditation Association for Ambulatory Health Care (AAAHC) (Performance Measurement Initiative, 1999a, 1999b, 2000a, 2000b). The IQI was created to offer clinical performance measurement and improvement opportunities to ambulatory health care organizations and others interested in quality patient care. The purpose of the study was to provide opportunities to initiate clinical performance measurement on key processes and outcomes for this procedure and use this information for clinical quality improvement. This article provides performance measurement information on how organizations that have demonstrated and validated differences in clinical practice can have similar outcomes, but at a dramatically lower cost. The intent of the article is to provide organizations with alternatives in practice to provide a better value to their patients.

  2. Performance diagnostic system for emergency diesel generators

    International Nuclear Information System (INIS)

    Logan, K.P.

    1991-01-01

    Diesel generators are commonly used for emergency backup power at nuclear stations. Emergency diesel generators (EDGs) are subject to both start-up and operating failures, due to infrequent and fast-start use. EDG reliability can be critical to plant safety, particularly when station blackout occurs. This paper describes an expert diagnostic system designed to consistently evaluate the operating performance of diesel generators. The prototype system is comprised of a suite of sensor monitoring, cylinder combustion analyzing, and diagnostic workstation computers. On-demand assessments of generator and auxiliary equipment performance are provided along with color trend displays comparing measured performance to reference-normal conditions

  3. Methodology for quantitative evaluation of diagnostic performance

    International Nuclear Information System (INIS)

    Metz, C.

    1981-01-01

    Of various approaches that might be taken to the diagnostic performance evaluation problem, Receiver Operating Characteristic (ROC) analysis holds great promise. Further development of the methodology for a unified, objective, and meaningful approach to evaluating the usefulness of medical imaging procedures is done by consideration of statistical significance testing, optimal sequencing of correlated studies, and analysis of observer performance

  4. The LYRA Instrument Onboard PROBA2: Description and In-Flight Performance

    Science.gov (United States)

    Dominique, M.; Hochedez, J.-F.; Schmutz, W.; Dammasch, I. E.; Shapiro, A. I.; Kretzschmar, M.; Zhukov, A. N.; Gillotay, D.; Stockman, Y.; BenMoussa, A.

    2013-08-01

    The Large Yield Radiometer (LYRA) is an XUV-EUV-MUV (soft X-ray to mid-ultraviolet) solar radiometer onboard the European Space Agency Project for On-Board Autonomy 2 (PROBA2) mission, which was launched in November 2009. LYRA acquires solar-irradiance measurements at a high cadence (nominally 20 Hz) in four broad spectral channels, from soft X-ray to MUV, which have been chosen for their relevance to solar physics, space weather, and aeronomy. We briefly review the design of the instrument, give an overview of the data products distributed through the instrument website, and describe how the data are calibrated. We also briefly present a summary of the main fields of research currently under investigation by the LYRA consortium.

  5. Evaluating real-world CO2 and NOX emissions for public transit buses using a remote wireless on-board diagnostic (OBD) approach.

    Science.gov (United States)

    Yang, Liuhanzi; Zhang, Shaojun; Wu, Ye; Chen, Qizheng; Niu, Tianlin; Huang, Xu; Zhang, Shida; Zhang, Liangjun; Zhou, Yu; Hao, Jiming

    2016-11-01

    The challenge to mitigate real-world emissions from vehicles calls for powerful in-use compliance supervision. The remote on-board diagnostic (OBD) approach, with wireless data communications, is one of the promising next-generation monitoring methods. We collected second-by-second profiles of carbon dioxide (CO 2 ) and nitrogen oxides (NO X ) emissions, driving conditions and engine performance for three conventional diesel and three hybrid diesel buses participating in a remote OBD pilot program in Nanjing, China. Our results showed that the average CO 2 emissions for conventional diesel and hybrid diesel buses were 816 ± 83 g km -1 and 627 ± 54 g km -1 , respectively, under a typical driving pattern. An operating mode binning analysis indicated that CO 2 emissions reduction by series-parallel hybrid technology was largely because of the significant benefits of the technology under the modes of low speed and low power demand. However, significantly higher CO 2 emissions were observed for conventional diesel buses during rush hours, higher than 1200 g km -1 . The OBD data suggested no improvement in NO X emission reduction for hybrid buses compared with conventional buses; both were approximately 12 g km -1 because of poor performance of the selective catalyst reduction (SCR) systems in the real world. Speed-dependent functions for real-world CO 2 and NO X emissions were also constructed. The CO 2 emissions of hybrid buses were much less sensitive to the average speed than conventional buses. If the average speed decreased from 20 km h -1 to 10 km h -1 , the estimated CO 2 emission factor for conventional buses would be increased by 34%. Such a change in speed would increase NO X emissions for conventional and hybrid buses by 38% and 56%, respectively. This paper demonstrates the useful features of the remote OBD system and can inform policy makers how to take advantage of these features in monitoring in-use vehicles. Copyright © 2016 Elsevier

  6. Session 4: On-board exhaust gas reforming for improved performance of natural gas HCCI engines

    Energy Technology Data Exchange (ETDEWEB)

    Amieiro, A.; Golunski, S.; James, D. [Johnson Matthey Technology Centre, Sonning Common, Reading (United Kingdom); Miroslaw, Wyszynski; Athanasios, Megaritis; Peucheret, S. [Birmingham Univ., School of Engineering, Future Power Systems Research Group (United Kingdom); Hongming, Xu [Jaguar Cars Ltd, W/2/021 Engineering Centre, Whitley, Coventry (United Kingdom)

    2004-07-01

    Although natural gas (NG) is a non-renewable energy source, it is still a very attractive alternative fuel for transportation - it is inexpensive, abundant, and easier to refine than petroleum. Unfortunately the minimum spark energy required for NG ignition is higher than for liquid fuels, and engine performance is reduced since the higher volume of NG limits the air breathing capacity of the cylinders. On the other hand, the flammability range of NG is wider than for other hydrocarbons, so the engine can operate under leaner conditions. Environmentally, the use of NG is particularly attractive since it has a low flame temperature (resulting in reduced NO{sub x} emissions) and a low carbon content compared to diesel or gasoline (resulting in less CO, CO{sub 2} and particulate). In addition, NG is easily made sulphur-free, and has a high octane rating (RON = 110-130) which makes it suitable for high compression engine applications. Exhaust gas recirculation (EGR) into an engine is known to reduce both flame temperature and speed, and therefore produce lower NO{sub x} emissions. In general, a given volume of exhaust gas has a greater effect on flame speed and NO{sub x} emissions than the same quantity of excess air, although there is a limit to the amount of exhaust gas recirculation that can be used without inhibiting combustion. However, hydrogen addition to exhaust gas recirculation has been proved to reduce emissions while increasing flame speed, so improving both the emissions and the thermal efficiency of the engine. On-board reforming of some of the fuel, by reaction with exhaust gas during EGR, is a novel way of adding hydrogen to an engine. We have carried out reforming tests on mixtures of natural gas and exhaust gas at relatively low temperatures (400-600 C), to mimic the low availability of external heat within the integrated system. The reforming catalyst is a nickel-free formulation, containing precious metals promoted by metal oxides. The roles of

  7. Impact of hydrogen onboard storage technologies on the performance of hydrogen fuelled vehicles: A techno-economic well-to-wheel assessment

    NARCIS (Netherlands)

    de Wit, M.P.; Faaij, A.P.C.

    2007-01-01

    Hydrogen onboard storage technologies form an important factor in the overall performance of hydrogen fuelled transportation, both energetically and economically. Particularly, advanced storage options such as metal hydrides and carbon nanotubes are often hinted favourable to conventional, liquid

  8. Feasibility of introducing ferromagnetic materials to onboard bulk high-Tc superconductors to enhance the performance of present maglev systems

    International Nuclear Information System (INIS)

    Deng, Zigang; Wang, Jiasu; Zheng, Jun; Zhang, Ya; Wang, Suyu

    2013-01-01

    Highlights: ► Ferromagnetic materials guide the flux distribution of the PMG to bulk positions. ► With ferromagnetic materials, guidance performance can be enhanced greatly. ► A new HTS Maglev system with onboard ferromagnetic materials is designed. ► The design can meet large guidance force requirements for practical applications. -- Abstract: Performance improvement is a long-term research task for the promotion of practical application of promising high-temperature superconducting (HTS) magnetic levitation (maglev) vehicle technologies. We studied the feasibility to enhance the performance of present HTS Maglev systems by introducing ferromagnetic materials to onboard bulk superconductors. The principle here is to make use of the high magnetic permeability of ferromagnetic materials to alter the flux distribution of the permanent magnet guideway for the enhancement of magnetic field density at the position of the bulk superconductors. Ferromagnetic iron plates were added to the upper surface of bulk superconductors and their geometric and positioning effects on the maglev performance were investigated experimentally. Results show that the guidance performance (stability) was enhanced greatly for a particular setup when compared to the present maglev system which is helpful in the application where large guidance forces are needed such as maglev tracks with high degrees of curves

  9. Diagnostics and performance evaluation of multikilohertz capacitors

    International Nuclear Information System (INIS)

    McDuff, G.; Nunnally, W.C.; Rust, K.; Sarjeant, J.

    1980-01-01

    The observed performance of nanofarad polypropylene-silicone oil, mica paper, and polytetrafluoroethylene-silicone oil capacitors discharged in a 100-ns, 1-kA pulse with a pulse repetition frequency of 1 kHz is presented. The test facility circuit, diagnostic parameters, and the preliminary test schedule are outlined as a basis for discussion of the observed failure locations and proposed failure mechanisms. Most of the test data and discussion presented involves the polypropylene-silicone oil units

  10. Feasibility of introducing ferromagnetic materials to onboard bulk high-Tc superconductors to enhance the performance of present maglev systems

    Science.gov (United States)

    Deng, Zigang; Wang, Jiasu; Zheng, Jun; Zhang, Ya; Wang, Suyu

    2013-02-01

    Performance improvement is a long-term research task for the promotion of practical application of promising high-temperature superconducting (HTS) magnetic levitation (maglev) vehicle technologies. We studied the feasibility to enhance the performance of present HTS Maglev systems by introducing ferromagnetic materials to onboard bulk superconductors. The principle here is to make use of the high magnetic permeability of ferromagnetic materials to alter the flux distribution of the permanent magnet guideway for the enhancement of magnetic field density at the position of the bulk superconductors. Ferromagnetic iron plates were added to the upper surface of bulk superconductors and their geometric and positioning effects on the maglev performance were investigated experimentally. Results show that the guidance performance (stability) was enhanced greatly for a particular setup when compared to the present maglev system which is helpful in the application where large guidance forces are needed such as maglev tracks with high degrees of curves.

  11. 49 CFR Appendix A to Part 395 - Electronic On-Board Recorder Performance Specifications

    Science.gov (United States)

    2010-10-01

    ... recorded according to a “flat file” database model format. A flat file is a simple database in which all information is stored in a plain text format with one database “record” per line. Each of these data records... unit to factory for servicing). General System Diagnostic MEMERR memory error System memory error...

  12. Performances of Kevlar and Polyethylene as radiation shielding on-board the International Space Station in high latitude radiation environment.

    Science.gov (United States)

    Narici, Livio; Casolino, Marco; Di Fino, Luca; Larosa, Marianna; Picozza, Piergiorgio; Rizzo, Alessandro; Zaconte, Veronica

    2017-05-10

    Passive radiation shielding is a mandatory element in the design of an integrated solution to mitigate the effects of radiation during long deep space voyages for human exploration. Understanding and exploiting the characteristics of materials suitable for radiation shielding in space flights is, therefore, of primary importance. We present here the results of the first space-test on Kevlar and Polyethylene radiation shielding capabilities including direct measurements of the background baseline (no shield). Measurements are performed on-board of the International Space Station (Columbus modulus) during the ALTEA-shield ESA sponsored program. For the first time the shielding capability of such materials has been tested in a radiation environment similar to the deep-space one, thanks to the feature of the ALTEA system, which allows to select only high latitude orbital tracts of the International Space Station. Polyethylene is widely used for radiation shielding in space and therefore it is an excellent benchmark material to be used in comparative investigations. In this work we show that Kevlar has radiation shielding performances comparable to the Polyethylene ones, reaching a dose rate reduction of 32 ± 2% and a dose equivalent rate reduction of 55 ± 4% (for a shield of 10 g/cm 2 ).

  13. The F-16 Onboard Oxygen Generating System: Performance Evaluation and Man Rating

    Science.gov (United States)

    1983-08-01

    OXYGEN GENERATING , YSTEM: PERFORMANCE EVALUATION AND MAN RATING Thomas C. Horch , Captain, USAF Richard L. Miller, Ph.D. John B. Bomar, Jr...C. Horch , Capt, USAF; R. L. Miller, 8. CONTRACT OR GRANT NUMBER(i) Ph.D.; J. B. Bomar, Jr., Lt Col, IJSAF, BSC; J. B. Tedor, Maj, USAF, BSC; R. D...limitation (as of 1983); however, the information may no longer need protection since it is 14 years. At the time of its publication, Capt Thomas Horch

  14. Performance modeling of unmanned aerial vehicles with on-board energy harvesting

    Science.gov (United States)

    Anton, Steven R.; Inman, Daniel J.

    2011-03-01

    The concept of energy harvesting in unmanned aerial vehicles (UAVs) has received much attention in recent years. Solar powered flight of small aircraft dates back to the 1970s when the first fully solar flight of an unmanned aircraft took place. Currently, research has begun to investigate harvesting ambient vibration energy during the flight of UAVs. The authors have recently developed multifunctional piezoelectric self-charging structures in which piezoelectric devices are combined with thin-film lithium batteries and a substrate layer in order to simultaneously harvest energy, store energy, and carry structural load. When integrated into mass and volume critical applications, such as unmanned aircraft, multifunctional devices can provide great benefit over conventional harvesting systems. A critical aspect of integrating any energy harvesting system into a UAV, however, is the potential effect that the additional system has on the performance of the aircraft. Added mass and increased drag can significantly degrade the flight performance of an aircraft, therefore, it is important to ensure that the addition of an energy harvesting system does not adversely affect the efficiency of a host aircraft. In this work, a system level approach is taken to examine the effects of adding both solar and piezoelectric vibration harvesting to a UAV test platform. A formulation recently presented in the literature is applied to describe the changes to the flight endurance of a UAV based on the power available from added harvesters and the mass of the harvesters. Details of the derivation of the flight endurance model are reviewed and the formulation is applied to an EasyGlider remote control foam hobbyist airplane, which is selected as the test platform for this study. A theoretical study is performed in which the normalized change in flight endurance is calculated based on the addition of flexible thin-film solar panels to the upper surface of the wings, as well as the addition

  15. The diagnostic odds ratio: a single indicator of test performance

    NARCIS (Netherlands)

    Glas, Afina S.; Lijmer, Jeroen G.; Prins, Martin H.; Bonsel, Gouke J.; Bossuyt, Patrick M. M.

    2003-01-01

    Diagnostic testing can be used to discriminate subjects with a target disorder from subjects without it. Several indicators of diagnostic performance have been proposed, such as sensitivity and specificity. Using paired indicators can be a disadvantage in comparing the performance of competing

  16. Malaria Laboratory Diagnostic Performance: Case studies of two ...

    African Journals Online (AJOL)

    Advantages of rapid diagnostic tests when compared with microscopy are simple to perform, fast, low ... The study was conducted to establish the performance of laboratory diagnosis of malaria in local Malawi .... Government of Malawi.

  17. Methodology for evaluation of diagnostic performance

    International Nuclear Information System (INIS)

    Metz, C.E.

    1992-01-01

    Effort in this project during the past year has focused on the development, refinement, and distribution of computer software that will allow current Receiver Operating Characteristic (ROC) methodology to be used conveniently and reliably by investigators in a variety of evaluation tasks in diagnostic medicine; and on the development of new ROC methodology that will broaden the spectrum of evaluation tasks and/or experimental settings to which the fundamental approach can be applied. Progress has been limited by the amount of financial support made available to the project

  18. Model of critical diagnostic reasoning: achieving expert clinician performance.

    Science.gov (United States)

    Harjai, Prashant Kumar; Tiwari, Ruby

    2009-01-01

    Diagnostic reasoning refers to the analytical processes used to determine patient health problems. While the education curriculum and health care system focus on training nurse clinicians to accurately recognize and rescue clinical situations, assessments of non-expert nurses have yielded less than satisfactory data on diagnostic competency. The contrast between the expert and non-expert nurse clinician raises the important question of how differences in thinking may contribute to a large divergence in accurate diagnostic reasoning. This article recognizes superior organization of one's knowledge base, using prototypes, and quick retrieval of pertinent information, using similarity recognition as two reasons for the expert's superior diagnostic performance. A model of critical diagnostic reasoning, using prototypes and similarity recognition, is proposed and elucidated using case studies. This model serves as a starting point toward bridging the gap between clinical data and accurate problem identification, verification, and management while providing a structure for a knowledge exchange between expert and non-expert clinicians.

  19. Feasibility of introducing ferromagnetic materials to onboard bulk high-T{sub c} superconductors to enhance the performance of present maglev systems

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Zigang, E-mail: zgdeng@gmail.com [Applied Superconductivity Laboratory (ASCLab), Southwest Jiaotong University (SWJTU), Chengdu, Sichuan 610031 (China); State Key Laboratory of Traction Power (TPL), Southwest Jiaotong University (SWJTU), Chengdu, Sichuan 610031 (China); Wang, Jiasu [Applied Superconductivity Laboratory (ASCLab), Southwest Jiaotong University (SWJTU), Chengdu, Sichuan 610031 (China); Zheng, Jun; Zhang, Ya [Applied Superconductivity Laboratory (ASCLab), Southwest Jiaotong University (SWJTU), Chengdu, Sichuan 610031 (China); State Key Laboratory of Traction Power (TPL), Southwest Jiaotong University (SWJTU), Chengdu, Sichuan 610031 (China); Wang, Suyu [Applied Superconductivity Laboratory (ASCLab), Southwest Jiaotong University (SWJTU), Chengdu, Sichuan 610031 (China)

    2013-02-14

    Highlights: ► Ferromagnetic materials guide the flux distribution of the PMG to bulk positions. ► With ferromagnetic materials, guidance performance can be enhanced greatly. ► A new HTS Maglev system with onboard ferromagnetic materials is designed. ► The design can meet large guidance force requirements for practical applications. -- Abstract: Performance improvement is a long-term research task for the promotion of practical application of promising high-temperature superconducting (HTS) magnetic levitation (maglev) vehicle technologies. We studied the feasibility to enhance the performance of present HTS Maglev systems by introducing ferromagnetic materials to onboard bulk superconductors. The principle here is to make use of the high magnetic permeability of ferromagnetic materials to alter the flux distribution of the permanent magnet guideway for the enhancement of magnetic field density at the position of the bulk superconductors. Ferromagnetic iron plates were added to the upper surface of bulk superconductors and their geometric and positioning effects on the maglev performance were investigated experimentally. Results show that the guidance performance (stability) was enhanced greatly for a particular setup when compared to the present maglev system which is helpful in the application where large guidance forces are needed such as maglev tracks with high degrees of curves.

  20. Acoustic detection in superconducting magnets for performance characterization and diagnostics

    OpenAIRE

    Marchevsky, M.; Wang, X.; Sabbi, G.; Prestemon, S.

    2014-01-01

    Quench diagnostics in superconducting accelerator magnets is essential for understanding performance limitations and improving magnet design. Applicability of the conventional quench diagnostics methods such as voltage taps or quench antennas is limited for long magnets or complex winding geometries, and alternative approaches are desirable. Here, we discuss acoustic sensing technique for detecting mechanical vibrations in superconducting magnets. Using LARP high-field Nb3Sn quadrupole HQ01 [...

  1. Performance evaluation of lunar penetrating radar onboard the rover of CE-3 probe based on results from ground experiments

    Science.gov (United States)

    Zhang, Hong-Bo; Zheng, Lei; Su, Yan; Fang, Guang-You; Zhou, Bin; Feng, Jian-Qing; Xing, Shu-Guo; Dai, Shun; Li, Jun-Duo; Ji, Yi-Cai; Gao, Yun-Ze; Xiao, Yuan; Li, Chun-Lai

    2014-12-01

    Lunar Penetrating Radar (LPR) onboard the rover that is part of the Chang'e-3 (CE-3) mission was firstly utilized to obtain in situ measurements about geological structure on the lunar surface and the thickness of the lunar regolith, which are key elements for studying the evolutional history of lunar crust. Because penetration depth and resolution of LPR are related to the scientific objectives of this mission, a series of ground-based experiments using LPR was carried out, and results of the experimental data were obtained in a glacial area located in the northwest region of China. The results show that the penetration depth of the first channel antenna used for LPR is over 79 m with a resolution of 2.8 m, and that for the second channel antenna is over 50.8 m with a resolution of 17.1 cm.

  2. Performance evaluation of lunar penetrating radar onboard the rover of CE-3 probe based on results from ground experiments

    International Nuclear Information System (INIS)

    Zhang Hong-Bo; Zheng Lei; Su Yan; Feng Jian-Qing; Xing Shu-Guo; Dai Shun; Li Jun-Duo; Xiao Yuan; Li Chun-Lai; Fang Guang-You; Zhou Bin; Ji Yi-Cai; Gao Yun-Ze

    2014-01-01

    Lunar Penetrating Radar (LPR) onboard the rover that is part of the Chang'e-3 (CE-3) mission was firstly utilized to obtain in situ measurements about geological structure on the lunar surface and the thickness of the lunar regolith, which are key elements for studying the evolutional history of lunar crust. Because penetration depth and resolution of LPR are related to the scientific objectives of this mission, a series of ground-based experiments using LPR was carried out, and results of the experimental data were obtained in a glacial area located in the northwest region of China. The results show that the penetration depth of the first channel antenna used for LPR is over 79 m with a resolution of 2.8 m, and that for the second channel antenna is over 50.8 m with a resolution of 17.1 cm

  3. Resilient actions in the diagnostic process and system performance.

    Science.gov (United States)

    Smith, Michael W; Davis Giardina, Traber; Murphy, Daniel R; Laxmisan, Archana; Singh, Hardeep

    2013-12-01

    Systemic issues can adversely affect the diagnostic process. Many system-related barriers can be masked by 'resilient' actions of frontline providers (ie, actions supporting the safe delivery of care in the presence of pressures that the system cannot readily adapt to). We explored system barriers and resilient actions of primary care providers (PCPs) in the diagnostic evaluation of cancer. We conducted a secondary data analysis of interviews of PCPs involved in diagnostic evaluation of 29 lung and colorectal cancer cases. Cases covered a range of diagnostic timeliness and were analysed to identify barriers for rapid diagnostic evaluation, and PCPs' actions involving elements of resilience addressing those barriers. We rated these actions according to whether they were usual or extraordinary for typical PCP work. Resilient actions and associated barriers were found in 59% of the cases, in all ranges of timeliness, with 40% involving actions rated as beyond typical. Most of the barriers were related to access to specialty services and coordination with patients. Many of the resilient actions involved using additional communication channels to solicit cooperation from other participants in the diagnostic process. Diagnostic evaluation of cancer involves several resilient actions by PCPs targeted at system deficiencies. PCPs' actions can sometimes mitigate system barriers to diagnosis, and thereby impact the sensitivity of 'downstream' measures (eg, delays) in detecting barriers. While resilient actions might enable providers to mitigate system deficiencies in the short run, they can be resource intensive and potentially unsustainable. They complement, rather than substitute for, structural remedies to improve system performance. Measures to detect and fix system performance issues targeted by these resilient actions could facilitate diagnostic safety.

  4. Performance Assessment as a Diagnostic Tool for Science Teachers

    Science.gov (United States)

    Kruit, Patricia; Oostdam, Ron; van den Berg, Ed; Schuitema, Jaap

    2018-04-01

    Information on students' development of science skills is essential for teachers to evaluate and improve their own education, as well as to provide adequate support and feedback to the learning process of individual students. The present study explores and discusses the use of performance assessments as a diagnostic tool for formative assessment to inform teachers and guide instruction of science skills in primary education. Three performance assessments were administered to more than 400 students in grades 5 and 6 of primary education. Students performed small experiments using real materials while following the different steps of the empirical cycle. The mutual relationship between the three performance assessments is examined to provide evidence for the value of performance assessments as useful tools for formative evaluation. Differences in response patterns are discussed, and the diagnostic value of performance assessments is illustrated with examples of individual student performances. Findings show that the performance assessments were difficult for grades 5 and 6 students but that much individual variation exists regarding the different steps of the empirical cycle. Evaluation of scores as well as a more substantive analysis of students' responses provided insight into typical errors that students make. It is concluded that performance assessments can be used as a diagnostic tool for monitoring students' skill performance as well as to support teachers in evaluating and improving their science lessons.

  5. Magnetic resonance imaging of the wrist: Diagnostic performance statistics

    International Nuclear Information System (INIS)

    Hobby, Jonathan L.; Tom, Brian D.M.; Bearcroft, Philip W.P.; Dixon, Adrian K.

    2001-01-01

    AIM: To review the published diagnostic performance statistics for magnetic resonance imaging (MRI) of the wrist for tears of the triangular fibrocartilage complex, the intrinsic carpal ligaments, and for osteonecrosis of the carpal bones. MATERIALS AND METHODS: We used Medline and Embase to search the English language literature. Studies evaluating the diagnostic performance of MRI of the wrist in living patients with surgical confirmation of MR findings were identified. RESULTS: We identified 11 studies reporting the diagnostic performance of MRI for tears of the triangular fibrocartilage complex for a total of 410 patients, six studies for the scapho-lunate ligament (159 patients), six studies for the luno-triquetral ligament (142 patients) and four studies (56 patients) for osteonecrosis of the carpal bones. CONCLUSIONS: Magnetic resonance imaging is an accurate means of diagnosing tears of the triangular fibrocartilage and carpal osteonecrosis. Although MRI is highly specific for tears of the intrinsic carpal ligaments, its sensitivity is low. The diagnostic performance of MRI in the wrist is improved by using high-resolution T2* weighted 3D gradient echo sequences. Using current imaging techniques without intra-articular contrast medium, magnetic resonance imaging cannot reliably exclude tears of the intrinsic carpal ligaments. Hobby, J.L. (2001)

  6. Acoustic detection in superconducting magnets for performance characterization and diagnostics

    International Nuclear Information System (INIS)

    Marchevsky, M; Wang, X; Sabbi, G; Prestemon, S

    2013-01-01

    Quench diagnostics in superconducting accelerator magnets is essential for understanding performance limitations and improving magnet design. Applicability of the conventional quench diagnostics methods such as voltage taps or quench antennas is limited for long magnets or complex winding geometries, and alternative approaches are desirable. Here, we discuss acoustic sensing technique for detecting mechanical vibrations in superconducting magnets. Using LARP high-field Nb3Sn quadrupole HQ01, we show how acoustic data is connected with voltage instabilities measured simultaneously in the magnet windings during provoked extractions and current ramps to quench. Instrumentation and data analysis techniques for acoustic sensing are reviewed. (author)

  7. Acoustic detection in superconducting magnets for performance characterization and diagnostics

    CERN Document Server

    Marchevsky, M.; Sabbi, G.; Prestemon, S.

    2013-01-01

    Quench diagnostics in superconducting accelerator magnets is essential for understanding performance limitations and improving magnet design. Applicability of the conventional quench diagnostics methods such as voltage taps or quench antennas is limited for long magnets or complex winding geometries, and alternative approaches are desirable. Here, we discuss acoustic sensing technique for detecting mechanical vibrations in superconducting magnets. Using LARP high-field Nb$_{3}$Sn quadrupole HQ01 [1], we show how acoustic data is connected with voltage instabilities measured simultaneously in the magnet windings during provoked extractions and current ramps to quench. Instrumentation and data analysis techniques for acoustic sensing are reviewed.

  8. Statistical evaluation of diagnostic performance topics in ROC analysis

    CERN Document Server

    Zou, Kelly H; Bandos, Andriy I; Ohno-Machado, Lucila; Rockette, Howard E

    2016-01-01

    Statistical evaluation of diagnostic performance in general and Receiver Operating Characteristic (ROC) analysis in particular are important for assessing the performance of medical tests and statistical classifiers, as well as for evaluating predictive models or algorithms. This book presents innovative approaches in ROC analysis, which are relevant to a wide variety of applications, including medical imaging, cancer research, epidemiology, and bioinformatics. Statistical Evaluation of Diagnostic Performance: Topics in ROC Analysis covers areas including monotone-transformation techniques in parametric ROC analysis, ROC methods for combined and pooled biomarkers, Bayesian hierarchical transformation models, sequential designs and inferences in the ROC setting, predictive modeling, multireader ROC analysis, and free-response ROC (FROC) methodology. The book is suitable for graduate-level students and researchers in statistics, biostatistics, epidemiology, public health, biomedical engineering, radiology, medi...

  9. Study of the performance of diagnostic radiology instruments during calibration

    International Nuclear Information System (INIS)

    Freitas, Rodrigo N. de; Vivolo, Vitor; Potiens, Maria da Penha A.

    2008-01-01

    Full text: The instruments used in diagnostic radiology measurements represent 8 % of the tested instruments by the calibration laboratory of IPEN annually (approximately 1600 in 2007). Considering that the calibration of this kind of instrument is performed biannually it is possible to conclude that almost 300 instruments are being used to measure the air kerma in diagnostic radiology clinics to determine the in beam values (in front of the patient), attenuated measurements (behind the patient) and scattered radiation. This work presents the results of the calibration of the instruments used in mammography, computed tomography, dental and conventional diagnostic radiology dosimetry, performed during the period of 2005 to 2007. Their performances during the calibrations measurements were evaluated. Although at the calibration laboratory there are three available series of radiation quality to this type of calibration (RQR, N and M, according to standards IEC 61267 and ISO 4037-1.), the applications can be assorted (general radiology, computed tomography, mammography, radiation protection and fluoroscopy). Depending on its design and behaviour , one kind of instrument can be used for one or more type of applications. The instruments normally used for diagnostic radiology measurements are ionization chambers with volumes varying from 3 to 1800 cm 3 , and can be cylindrical, spherical or plane parallel plates kind. They usually are sensitive to photon particles, with energies greater than 15 keV and can be used up to 1200 keV. In this work they were tested in X radiation fields from 25 to 150 kV, in specific qualities depending on the utilization of the instrument. The calibration results of 390 instruments received from 2005 to 2007 were analyzed. About 20 instruments were not able to be calibrated due to bad functioning. The calibration coefficients obtained were between 0.88 and 1.24. The uncertainties were always less than ± 3.6% to instruments used in scattered

  10. Static dosimetry space image in which urology diagnostics are performed

    International Nuclear Information System (INIS)

    Banduka, M.S.; Vasic, D.D.

    2002-01-01

    Background. The effects of the dispersed radiation described theoretically imply complex picture of interaction of the photon beam with the patient's body, as well as its dispersion on other structures. Basic theoretical laws of this phenomenon are highlighted, thus giving the opportunity to model the effect in total. Material and methods. The measurements of the absorbed dose in the air give isodose curves that show distribution of the radiation dose. For the urological procedures standard urological diagnostic methods were being used. Results. Through a large series of measuring, we got the distribution of the radiation dose in space, where urology diagnostics is being made using the X-ray. The parameters determining this picture are the most frequent ones in the total number of 20 random cases taken in General Hospital in Doboj, Bosnia and Herzegovina. Conclusions. Static dosimetric picture of the space (radiation zone) in the general sense is useful before all for organisation of the diagnostic procedures utilising ionised radiation. Obtained in any way, this picture enables an insight into the three-dimensional distribution of the dosage on the basis of which it is possible to correct the organisation of the diagnostics being performed under these conditions. The values of the radiation dosage show it is necessary to use the protecting means prescribed by law. For more frequent exposure, it would be useful to make a dynamic dosimetric picture for professional exposure and assessment of the radiation risk of these persons. (author)

  11. Onboard software of Plasma Wave Experiment aboard Arase: instrument management and signal processing of Waveform Capture/Onboard Frequency Analyzer

    Science.gov (United States)

    Matsuda, Shoya; Kasahara, Yoshiya; Kojima, Hirotsugu; Kasaba, Yasumasa; Yagitani, Satoshi; Ozaki, Mitsunori; Imachi, Tomohiko; Ishisaka, Keigo; Kumamoto, Atsushi; Tsuchiya, Fuminori; Ota, Mamoru; Kurita, Satoshi; Miyoshi, Yoshizumi; Hikishima, Mitsuru; Matsuoka, Ayako; Shinohara, Iku

    2018-05-01

    We developed the onboard processing software for the Plasma Wave Experiment (PWE) onboard the Exploration of energization and Radiation in Geospace, Arase satellite. The PWE instrument has three receivers: Electric Field Detector, Waveform Capture/Onboard Frequency Analyzer (WFC/OFA), and the High-Frequency Analyzer. We designed a pseudo-parallel processing scheme with a time-sharing system and achieved simultaneous signal processing for each receiver. Since electric and magnetic field signals are processed by the different CPUs, we developed a synchronized observation system by using shared packets on the mission network. The OFA continuously measures the power spectra, spectral matrices, and complex spectra. The OFA obtains not only the entire ELF/VLF plasma waves' activity but also the detailed properties (e.g., propagation direction and polarization) of the observed plasma waves. We performed simultaneous observation of electric and magnetic field data and successfully obtained clear wave properties of whistler-mode chorus waves using these data. In order to measure raw waveforms, we developed two modes for the WFC, `chorus burst mode' (65,536 samples/s) and `EMIC burst mode' (1024 samples/s), for the purpose of the measurement of the whistler-mode chorus waves (typically in a frequency range from several hundred Hz to several kHz) and the EMIC waves (typically in a frequency range from a few Hz to several hundred Hz), respectively. We successfully obtained the waveforms of electric and magnetic fields of whistler-mode chorus waves and ion cyclotron mode waves along the Arase's orbit. We also designed the software-type wave-particle interaction analyzer mode. In this mode, we measure electric and magnetic field waveforms continuously and transfer them to the mission data recorder onboard the Arase satellite. We also installed an onboard signal calibration function (onboard SoftWare CALibration; SWCAL). We performed onboard electric circuit diagnostics and

  12. Peripheral occlusive vascular disease: Diagnostic performance of MRA and DSA

    International Nuclear Information System (INIS)

    Krug, B.; Kugel, H.; Harnischmacher, U.; Heindel, W.; Altenburg, A.; Fischbach, R.; Schmidt, R.

    1995-01-01

    In 59 patients with arterial flow disturbances 2-D inflow sequence of the abdominal and lower leg arteries were prospectively obtained on a 1.5 T MR-imager and were compared with additional DSA examinations. Supplementary Phase Contraste RSE ('Rapid Sequential Excitation') sequences were carried out in 29 patients. MRA and DSA angiograms were evaluated in random order by 4 readers using a questionnaire. The assessment of image quality were evaluated by variance analysis. Diagnostic performance of MRA and DSA was assessed by comparison of the readers' diagnostic assessments with reference diagnoses established by a radiologist and a vascular surgeon with full knowledge of all data concerning a patient. Image quality of inflow MRA was considered inferior to i.a. DSA (p [de

  13. Methodology for quantitative evalution of diagnostic performance. Project III

    International Nuclear Information System (INIS)

    Metz, C.E.

    1985-01-01

    Receiver Operation Characteristic (ROC) methodology is now widely recognized as the most satisfactory approach to the problem of measuring and specifying the performance of a diagnostic procedure. The primary advantage of ROC analysis over alternative methodologies is that it seperates differences in diagnostic accuracy that are due to actual differences in discrimination capacity from those that are due to decision threshold effects. Our effort during the past year has been devoted to developing digital computer programs for fitting ROC curves to diagnostic data by maximum likelihood estimation and to developing meaningful and valid statistical tests for assessing the significance of apparent differences between measured ROC curves. FORTRAN programs previously written here for ROC curve fitting and statistical testing have been refined to make them easier to use and to allow them to be run in a large variety of computer systems. We have attempted also to develop two new curve-fitting programs: one for conventional ROC data that assumes a different functional form for the ROC curve, and one that can be used for ''free-response'' ROC data. Finally, we have cooperated with other investigators to apply our techniques to analyze ROC data generated in clinical studies, and we have sought to familiarize the medical community with the advantages of ROC methodology. 36 ref

  14. Detailed Performance Assessment for the ITER ECE Diagnostic

    Science.gov (United States)

    Rowan, W.; Austin, M.; Houshmandyar, S.; Phillips, P.; Beno, J.; Bryant, A.; Ouroua, A.; Weeks, D.; Hubbard, A.; Taylor, G.

    2017-10-01

    One of the primary diagnostics for electron temperature (Te) measurement on ITER is based on the detection of electron cyclotron emission (ECE) Here we describe the predicted performance of the newly completed ECE diagnostic design by quantitatively following the emission from the plasma to the instruments and including the calibration method to assess accuracy. Operation of the diagnostic at 5.3 T is the main interest here but critical features of the emission spectra for 2.65 T and 1.8 T will be described. ECE will be collected by two very similar optical systems: one a radial view, the other an oblique view. Both measurements are used for Te while the oblique view also allows detection of non-thermal distortion in the electron distribution. An in-vacuum calibration source is included in the front end of each view to calibrate out the effect of any degradation of in-vessel optics. Following collection, the emission is split into orthogonal polarizations and transmitted to the detection instruments via waveguides filled with dry nitrogen, a choice that simplifies construction and analysis. Near the instruments, a switchyard is used to select which polarization and view is detected by each instrument. The design for the radiometer used for 5.3 T will be described in detail. Supported by PPPL/US-DA via subcontract S013464-H to UT Austin.

  15. Aerial Logistics Management for Carrier Onboard Delivery

    Science.gov (United States)

    2016-09-01

    NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA THESIS AERIAL LOGISTICS MANAGEMENT FOR CARRIER ONBOARD DELIVERY by Samuel L. Chen September 2016...AND SUBTITLE AERIAL LOGISTICS MANAGEMENT FOR CARRIER ONBOARD DELIVERY 5. FUNDING NUMBERS 6. AUTHOR(S) Samuel L. Chen 7. PERFORMING ORGANIZATION NAME(S...delivery (COD) is the use of aircraft to transport people and cargo from a forward logistics site (FLS) to a carrier strike group (CSG). The goal of

  16. On performance of cylindrical dipole antenna in diagnostics of wave phenomena in space plasma

    Science.gov (United States)

    Kiraga, A.

    within upper hybrid band do not show up. In equivalent circuit simulations, salient spectral characteristics can be matched and related to specific impedances. Equivalent circuit analysis was enforced by apparent difference between local plasma frequencies derived from onboard topside sounder data and frequencies of adjacent maximum in passive mode spectra. It has been subsequently verified and developed with the aid of impedance measurements, onboard sounder data and analysis of electron beam induced spectra. We show that circuit resonance can be neatly controlled to provide very low interference technique to monitor density of cold plasma. Circuit resonance monitoring, if properly coupled with impedance measurements and electron beam injection may be very useful, low interference tool for diagnostics of highly structured plasmas like those in auroral region.

  17. Performance of a Processor for On-Board RFI Detection and Mitigation in MetOpSG Radiometers

    DEFF Research Database (Denmark)

    Skou, Niels; Kristensen, Steen Savstrup; Lahtinen, J.

    2016-01-01

    An RFI processor breadboard has been designed and developed for the second generation MetOp satellites. RFI detection is based on the anomalous amplitude, kurtosis, and cross-frequency algorithms. These are implemented in VHDL code in an FPGA. Thus algorithm performance can very well be assessed...... by proper code simulation. Such simulations show that the kurtosis algorithm as implemented works according to theory when subjected to pulsed sinusoidal and QPSK signals....

  18. Impacts of dairy diagnostic teams on herd performance.

    Science.gov (United States)

    Weinand, D; Conlin, B J

    2003-05-01

    This study evaluated impacts of educational diagnostic teams of consultants used to transfer technology to dairy farms. Herd management performance changes were measured by comparing Dairy Herd Improvement data from 38 project farms to data from herds that were geographical contemporaries. The value of focused goals for effecting change was also assessed. Interviews provided producers' perception of project outcomes and insight on organization and conduct of dairy diagnostic teams. Changes observed in project herds were small compared with controls with tendencies for increased herd size and improved milk production per cow. Focused goals had greater impacts on increasing herd size, milk per cow, first lactation peak milk, reducing age at first calving, and percentages of cows with subclinical mastitis. Time, money, facility limitations, labor, and alternative priorities were the most cited constraints to implementing changes. Satisfaction scores of producers were significantly related to the degree that team recommendations were followed. Improved attitudes, quality of life, and financial well-being were benefits listed by a majority of producers from participation in the project. If similar projects were to be offered, 83% said they would participate again, and 69% indicated they would pay at least some of the costs. Project farms served as demonstration farms for 1930 other producers in their respective locales, resulting in a multiplier effect of original advice given by consultant teams. Suggestions by farmer participants for improvements in dairy diagnostic teams included needs for at least some unbiased team members, more frequent meetings, more follow-up on recommendations, and consistency of recommendations with family goals.

  19. 30 CFR 250.520 - When do I have to perform a casing diagnostic test?

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false When do I have to perform a casing diagnostic... Operations Casing Pressure Management § 250.520 When do I have to perform a casing diagnostic test? (a) You must perform a casing diagnostic test within 30 days after first observing or imposing casing pressure...

  20. Study for the design method of multi-agent diagnostic system to improve diagnostic performance for similar abnormality

    International Nuclear Information System (INIS)

    Minowa, Hirotsugu; Gofuku, Akio

    2014-01-01

    Accidents on industrial plants cause large loss on human, economic, social credibility. In recent, studies of diagnostic methods using techniques of machine learning such as support vector machine is expected to detect the occurrence of abnormality in a plant early and correctly. There were reported that these diagnostic machines has high accuracy to diagnose the operating state of industrial plant under mono abnormality occurrence. But the each diagnostic machine on the multi-agent diagnostic system may misdiagnose similar abnormalities as a same abnormality if abnormalities to diagnose increases. That causes that a single diagnostic machine may show higher diagnostic performance than one of multi-agent diagnostic system because decision-making considering with misdiagnosis is difficult. Therefore, we study the design method for multi-agent diagnostic system to diagnose similar abnormality correctly. This method aimed to realize automatic generation of diagnostic system where the generation process and location of diagnostic machines are optimized to diagnose correctly the similar abnormalities which are evaluated from the similarity of process signals by statistical method. This paper explains our design method and reports the result evaluated our method applied to the process data of the fast-breeder reactor Monju

  1. Monitoring the Microgravity Environment Quality On-board the International Space Station Using Soft Computing Techniques. Part 2; Preliminary System Performance Results

    Science.gov (United States)

    Jules, Kenol; Lin, Paul P.; Weiss, Daniel S.

    2002-01-01

    This paper presents the preliminary performance results of the artificial intelligence monitoring system in full operational mode using near real time acceleration data downlinked from the International Space Station. Preliminary microgravity environment characterization analysis result for the International Space Station (Increment-2), using the monitoring system is presented. Also, comparison between the system predicted performance based on ground test data for the US laboratory "Destiny" module and actual on-orbit performance, using measured acceleration data from the U.S. laboratory module of the International Space Station is presented. Finally, preliminary on-orbit disturbance magnitude levels are presented for the Experiment of Physics of Colloids in Space, which are compared with on ground test data. The ground test data for the Experiment of Physics of Colloids in Space were acquired from the Microgravity Emission Laboratory, located at the NASA Glenn Research Center, Cleveland, Ohio. The artificial intelligence was developed by the NASA Glenn Principal Investigator Microgravity Services Project to help the principal investigator teams identify the primary vibratory disturbance sources that are active, at any moment of time, on-board the International Space Station, which might impact the microgravity environment their experiments are exposed to. From the Principal Investigator Microgravity Services' web site, the principal investigator teams can monitor via a dynamic graphical display, implemented in Java, in near real time, which event(s) is/are on, such as crew activities, pumps, fans, centrifuges, compressor, crew exercise, structural modes, etc., and decide whether or not to run their experiments, whenever that is an option, based on the acceleration magnitude and frequency sensitivity associated with that experiment. This monitoring system detects primarily the vibratory disturbance sources. The system has built-in capability to detect both known

  2. Scramjet Performance Assessment Using Water Absorption Diagnostics (U)

    Science.gov (United States)

    Cavolowsky, John A.; Loomis, Mark P.; Deiwert, George

    1995-01-01

    Simultaneous multiple path measurements of temperature and H2O concentration will be presented for the AIMHYE test entries in the NASA Ames 16-Inch Shock Tunnel. Monitoring the progress of high temperature chemical reactions that define scramjet combustor efficiencies is a task uniquely suited to nonintrusive optical diagnostics. One application strategy to overcome the many challenges and limitations of nonintrusive measurements is to use laser absorption spectroscopy coupled with optical fibers. Absorption spectroscopic techniques with rapidly tunable lasers are capable of making simultaneous measurements of mole fraction, temperature, pressure, and velocity. The scramjet water absorption diagnostic was used to measure combustor efficiency and was compared to thrust measurements using a nozzle force balance and integrated nozzle pressures to develop a direct technique for evaluating integrated scramjet performance. Tests were initially performed with a diode laser tuning over a water absorption feature at 1391.7 nm. A second diode laser later became available at a wavelength near 1343.3 nm covering an additional water absorption feature and was incorporated in the system for a two-wavelength technique. Both temperature and mole fraction can be inferred from the lineshape analysis using this approach. Additional high temperature spectroscopy research was conducted to reduce uncertainties in the scramjet application. The lasers are optical fiber coupled to ports at the combustor exit and in the nozzle region. The output from the two diode lasers were combined in a single fiber, and the resultant two-wavelength beam was subsequently split into four legs. Each leg was directed through 60 meters of optical fiber to four combustor exit locations for measurement of beam intensity after absorption by the water within the flow. Absorption results will be compared to 1D combustor analysis using RJPA and nozzle CFD computations as well as to data from a nozzle metric

  3. Malignant renal cysts: Diagnostic performance and strong predictors at MDCT

    International Nuclear Information System (INIS)

    Kim, Dae Yoon; Kim, Jeong Kon; Cho, Kyoung-Sik; Min, Gyeong-Eun; Ahn, Han-Jong

    2010-01-01

    Background: Utilization of multidetector-row CT (MDCT) is anticipated to improve the diagnostic accuracy and reliability for determining malignant cysts. Purpose: To assess the diagnostic accuracy, interobserver agreement, benefit of consensus reading, and strong predictors of malignancy in determining malignant cystic renal masses at MDCT. Material and Methods: Two radiologists independently rated the probability of malignancy at MDCT in 72 benign and 53 malignant cysts. The accuracy and interobserver agreement for determining malignant cysts were evaluated. The strong predictors of malignancy were determined, and in patients with interobserver disagreement for determining malignant cysts, consensus readings were performed. Results: Az value of the two readers was 0.905-0.936 and the sensitivity and specificity were 85-89% and 83-93%, respectively. The overall interobserver agreement for determining the malignant cyst was good as the κ value was 0.696 (% agreement, 61% (76/125)). Thickened irregular wall, thickened irregular septa, and enhancing soft tissue component were strong predictors for malignancy with both readers. In the 17 patients with interobserver disagreement for determining malignant cysts, the sensitivity was improved from 38-63% to 89% by the consensus reading. Conclusion: At MDCT, some false negative decisions for determining malignant cysts can be corrected by consensus reading, and thickened irregular septa, thickened irregular wall, and enhancing soft tissue component are the strong predictors of malignant cysts

  4. Penetrating Colorectal Injuries: Diagnostic Performance of Multidetector CT with Trajectography.

    Science.gov (United States)

    Dreizin, David; Boscak, Alexis R; Anstadt, Michael J; Tirada, Nikki; Chiu, William C; Munera, Felipe; Bodanapally, Uttam K; Hornick, Michael; Stein, Deborah M

    2016-12-01

    Purpose To determine the diagnostic performance of multidetector computed tomography (CT) with trajectography for penetrating colorectal injuries. Materials and Methods This institutional review board-approved and HIPAA-compliant study was a 6-year blinded retrospective review by two independent readers of 182 consecutive patients who preoperatively underwent 40- or 64-row multidetector CT for penetrating torso trauma below the diaphragm and had surgically confirmed findings. Colorectal perforation was present in 42 patients. Trajectory analysis with postprocessing software was used for all studies. Additional signs evaluated were rectal contrast agent leak, collections of extruded fecal material, mural defect, wall thickening, abnormal enhancement, free fluid or stranding, and free air. The quality of the colorectal contrast agent administration was recorded. Sensitivity, specificity, predictive values, areas under the receiver operating characteristic curves (AUCs), and Cohen κ were determined. Results In patients with rectal contrast agent administration (n = 151), AUCs were 0.90-0.91, which indicated excellent accuracy. Trajectory was sensitive (88%-91%). For single wounds (n = 104), sensitivity of trajectory was 96% for both readers, but was only 80% for multiple wounds (n = 47). Contrast agent leak was highly specific (96%-98%), but insensitive (42%-46%). Improved diagnostic performance was observed in patients with poor colonic distension or opacification. Accuracy remained high (AUC, 0.86-0.99) in the group without rectal contrast agent administration (n = 31). Conclusion Trajectory had excellent sensitivity, while rectal contrast agent leak was specific but insensitive. Sensitivity of trajectory was lower for multiple wounds. Accuracy remained high in patients without rectal contrast agent administration. © RSNA, 2016.

  5. The Influence of Time Pressure and Case Complexity on Physicians׳ Diagnostic Performance

    Directory of Open Access Journals (Sweden)

    Dalal A. ALQahtani

    2016-12-01

    Conclusions: Time pressure did not impact the diagnostic performance, whereas the complexity of the clinical case negatively influenced the diagnostic accuracy. Further studies with the enhanced experimental manipulation of time pressure are needed to reveal the effect of time pressure, if any, on a physician׳s diagnostic performance.

  6. Diagnostics

    DEFF Research Database (Denmark)

    Donné, A.J.H.; Costley, A.E.; Barnsley, R.

    2007-01-01

    of the measurements—time and spatial resolutions, etc—will in some cases be more stringent. Many of the measurements will be used in the real time control of the plasma driving a requirement for very high reliability in the systems (diagnostics) that provide the measurements. The implementation of diagnostic systems...... on ITER is a substantial challenge. Because of the harsh environment (high levels of neutron and gamma fluxes, neutron heating, particle bombardment) diagnostic system selection and design has to cope with a range of phenomena not previously encountered in diagnostic design. Extensive design and R......&D is needed to prepare the systems. In some cases the environmental difficulties are so severe that new diagnostic techniques are required. The starting point in the development of diagnostics for ITER is to define the measurement requirements and develop their justification. It is necessary to include all...

  7. Optimization of Planck-LFI on-board data handling

    Energy Technology Data Exchange (ETDEWEB)

    Maris, M; Galeotta, S; Frailis, M; Zacchei, A; Fogliani, S; Gasparo, F [INAF-OATs, Via G.B. Tiepolo 11, 34131 Trieste (Italy); Tomasi, M; Bersanelli, M [Universita di Milano, Dipartimento di Fisica, Via G. Celoria 16, 20133 Milano (Italy); Miccolis, M [Thales Alenia Space Italia S.p.A., S.S. Padana Superiore 290, 20090 Vimodrone (Italy); Hildebrandt, S; Chulani, H; Gomez, F [Instituto de Astrofisica de Canarias (IAC), C/o Via Lactea, s/n E38205 - La Laguna, Tenerife (Spain); Rohlfs, R; Morisset, N; Binko, P [ISDC Data Centre for Astrophysics, University of Geneva, ch. d' Ecogia 16, 1290 Versoix (Switzerland); Burigana, C; Butler, R C; Cuttaia, F; Franceschi, E [INAF-IASF Bologna, Via P. Gobetti, 101, 40129 Bologna (Italy); D' Arcangelo, O, E-mail: maris@oats.inaf.i [IFP-CNR, via Cozzi 53, 20125 Milano (Italy)

    2009-12-15

    To asses stability against 1/f noise, the Low Frequency Instrument (LFI) on-board the Planck mission will acquire data at a rate much higher than the data rate allowed by the science telemetry bandwith of 35.5 Kbps. The data are processed by an on-board pipeline, followed on-ground by a decoding and reconstruction step, to reduce the volume of data to a level compatible with the bandwidth while minimizing the loss of information. This paper illustrates the on-board processing of the scientific data used by Planck/LFI to fit the allowed data-rate, an intrinsecally lossy process which distorts the signal in a manner which depends on a set of five free parameters (N{sub aver}, r{sub 1}, r{sub 2}, q, O) for each of the 44 LFI detectors. The paper quantifies the level of distortion introduced by the on-board processing as a function of these parameters. It describes the method of tuning the on-board processing chain to cope with the limited bandwidth while keeping to a minimum the signal distortion. Tuning is sensitive to the statistics of the signal and has to be constantly adapted during flight. The tuning procedure is based on a optimization algorithm applied to unprocessed and uncompressed raw data provided either by simulations, pre-launch tests or data taken in flight from LFI operating in a special diagnostic acquisition mode. All the needed optimization steps are performed by an automated tool, OCA2, which simulates the on-board processing, explores the space of possible combinations of parameters, and produces a set of statistical indicators, among them: the compression rate C{sub r} and the processing noise epsilon{sub Q}. For Planck/LFI it is required that C{sub r} = 2.4 while, as for other systematics, epsilon{sub Q} would have to be less than 10% of rms of the instrumental white noise. An analytical model is developed that is able to extract most of the relevant information on the processing errors and the compression rate as a function of the signal

  8. Diagnostics for Evaluating Performance of NSTX Liquid Lihium Divertor

    Science.gov (United States)

    Kaita, R.; Kugel, H.; Kallman, J.; Leblanc, B.; Paul, S.; Roquemore, A. L.; Skinner, C.; Soukhanovskii, V.; Maingi, R.; Ahn, J.-W.; Wilgen, J.; Allain, J.-P.; Taylor, C.

    2009-11-01

    A Liquid Lithium Divertor (LLD) is being installed on NSTX to investigate particle control and power handling with liquid lithium as plasma-facing component (PFC). The LLD is expected to provide a low-recycling plasma-facing component (PFC). To study the effects of such a PFC on plasma performance, a variety of edge measurements are required. Since its surface is highly reflective at visible wavelengths, a Lyman-alpha detector array will be used to monitor the recycling. To understand changes in edge transport, electron temperature and density measurements will be made with Langmuir probes mounted in PFC's near the LLD, and the edge sightlines of a multipoint Thomson scattering system. A frequency-scanning reflectometer will also provide scrapeoff layer electron density profiles. The LLD response to heat loads will be examined with infrared cameras and thermocouples. Diagnostics are also needed to measure the erosion and codeposition of lithium. They include quartz deposition monitors and a retractable probe for exposing samples to the plasma.

  9. An audit of diagnostic tests performed in medical microbiology, and ...

    African Journals Online (AJOL)

    Clinical audit is an important tool for reviewing and improving the quality of service in clinical laboratories. This is a three year audit of diagnostic test carried out in Medical Microbiology and Immunology laboratories of University of Maiduguri Teaching Hospital, Maiduguri, Nigeria. The objectives were to document and ...

  10. ON-BOARD COMPUTER SYSTEM FOR KITSAT-1 AND 2

    Directory of Open Access Journals (Sweden)

    H. S. Kim

    1996-06-01

    Full Text Available KITSAT-1 and 2 are microsatellites weighting 50kg and all the on-board data are processed by the on-board computer system. Hence, these on-board computers require to be highly reliable and be designed with tight power consumption, mass and size constraints. On-board computer(OBC systems for KITSAT-1 and 2 are also designed with a simple flexible hardware for reliability and software takes more responsibility than hardware. KITSAT-1 and 2 on-board computer system consist of OBC 186 as the primary OBC and OBC80 as its backup. OBC186 runs spacecraft operating system (SCOS which has real-time multi-tasking capability. Since their launch, OBC186 and OBC80 have been operating successfully until today. In this paper, we describe the development of OBC186 hardware and software and analyze its in-orbit operation performance.

  11. The Impact of Gas Turbine Component Leakage Fault on GPA Performance Diagnostics

    Directory of Open Access Journals (Sweden)

    E. L. Ntantis

    2016-01-01

    Full Text Available The leakage analysis is a key factor in determining energy loss from a gas turbine. Once the components assembly fails, air leakage through the opening increases resulting in a performance loss. Therefore, the performance efficiency of the engine cannot be reliably determined, without good estimates and analysis of leakage faults. Consequently, the implementation of a leakage fault within a gas turbine engine model is necessary for any performance diagnostic technique that can expand its diagnostics capabilities for more accurate predictions. This paper explores the impact of gas turbine component leakage fault on GPA (Gas Path Analysis Performance Diagnostics. The analysis is demonstrated with a test case where gas turbine performance simulation and diagnostics code TURBOMATCH is used to build a performance model of a model engine similar to Rolls-Royce Trent 500 turbofan engine, and carry out the diagnostic analysis with the presence of different component fault cases. Conclusively, to improve the reliability of the diagnostic results, a leakage fault analysis of the implemented faults is made. The diagnostic tool used to deal with the analysis of the gas turbine component implemented faults is a model-based method utilizing a non-linear GPA.

  12. Sensor Selection for Aircraft Engine Performance Estimation and Gas Path Fault Diagnostics

    Science.gov (United States)

    Simon, Donald L.; Rinehart, Aidan W.

    2016-01-01

    This paper presents analytical techniques for aiding system designers in making aircraft engine health management sensor selection decisions. The presented techniques, which are based on linear estimation and probability theory, are tailored for gas turbine engine performance estimation and gas path fault diagnostics applications. They enable quantification of the performance estimation and diagnostic accuracy offered by different candidate sensor suites. For performance estimation, sensor selection metrics are presented for two types of estimators including a Kalman filter and a maximum a posteriori estimator. For each type of performance estimator, sensor selection is based on minimizing the theoretical sum of squared estimation errors in health parameters representing performance deterioration in the major rotating modules of the engine. For gas path fault diagnostics, the sensor selection metric is set up to maximize correct classification rate for a diagnostic strategy that performs fault classification by identifying the fault type that most closely matches the observed measurement signature in a weighted least squares sense. Results from the application of the sensor selection metrics to a linear engine model are presented and discussed. Given a baseline sensor suite and a candidate list of optional sensors, an exhaustive search is performed to determine the optimal sensor suites for performance estimation and fault diagnostics. For any given sensor suite, Monte Carlo simulation results are found to exhibit good agreement with theoretical predictions of estimation and diagnostic accuracies.

  13. Exercise echocardiography or exercise SPECT imaging? - A meta-analysis of diagnostic test performance

    NARCIS (Netherlands)

    Fleischmann, KE; Hunink, MGM; Kuntz, KM; Douglas, PS

    1998-01-01

    Context.-Cardiac imaging has advanced rapidly, providing clinicians with several choices for evaluating patients with suspected coronary artery disease, but few studies compare modalities directly. .-To review the contemporary literature and to compare the diagnostic performance of exercise

  14. Development of a computerized system for performance monitoring and diagnostics in nuclear power plants

    International Nuclear Information System (INIS)

    Chou, G.H.; Chao, H.J.

    1995-01-01

    An on-line computerized system for thermal performance monitoring and diagnostics has been developed at the Institute of Nuclear Energy Research (INER). It was the product of the ChinShan plant performance Monitoring, Analysis and Diagnostics Expert System (CS-MADES) project sponsored by Taiwan Power Company (TPC). The system can carry out turbine performance monitoring and analysis during normal operation, and yield diagnostic results of component degradation after finding out the missing generation problems. Three subsystems were generated to support the whole system framework. They are Test Data Processing Subsystem (TDPS), On-line Monitoring and Analysis Subsystem (OMAS), and Thermal Performance Diagnostics Expert System (TPDES). Some visible benefits have been gained so far through the prototype system installed at the Chinshan nuclear power station

  15. ROC Analysis of Diagnostic Performance in Liver Scan

    International Nuclear Information System (INIS)

    Lee, Myung Chul; Moon, Dyuk Hyuk; Koh, Chang Soon; Matumoto, Toru; Tateno, Yukio

    1988-01-01

    To evaluate diagnostic accuracy of liver scintigraphy we analysed liver scans of 143 normal and 258 patients with various liver diseases. Three ROC curves for SOL, liver cirrhosis and diffuse liver disease were fitted using rating methods and areas under the ROC curves and their standard errors were calculated by the trapezoidal rule and the variance of the Wilcoxon statistic suggested by McNeil. We compared these results with that of National Institute of Radiological Science in Japan. 1) The sensitivity of liver scintigraphy was 74.2% in SOL, 71.8% in liver cirrhosis and 34.8% in diffuse liver disease. The specificity was 96.0% in SOL, 94.2% in liver cirrhosis and 87.6% in diffuse liver disease. 2) ROC curves of SOL and liver cirrhosis approached the upper left-hand corner closer than that of diffuse liver disease. Area (± standard error) under the ROC curve was 0.868±0.024 in SOL and 0.867±0.028 in liver cirrhosis. These were significantly higher than 0.658±0.043 in diffuse liver disease. 3) There was no interobserver difference in terms of ROC curves. But low sensitivity and high specificity of authors' SOL diagnosis suggested we used more strict decision threshold.

  16. Autonomous onboard optical processor for driving aid

    Science.gov (United States)

    Attia, Mondher; Servel, Alain; Guibert, Laurent

    1995-01-01

    We take advantage of recent technological advances in the field of ferroelectric liquid crystal silicon back plane optoelectronic devices. These are well suited to perform massively parallel processing tasks. That choice enables the design of low cost vision systems and allows the implementation of an on-board system. We focus on transport applications such as road sign recognition. Preliminary in-car experimental results are presented.

  17. ROC analysis of diagnostic performance in liver scintigraphy

    International Nuclear Information System (INIS)

    Fritz, S.L.; Preston, D.F.; Gallagher, J.H.

    1981-01-01

    Studies on the accuracy of liver scintigraphy for the detection of metastases were assembled from 38 sources in the medical literature. An ROC curve was fitted to the observed values of sensitivity and specificity using an algorithm developed by Ogilvie and Creelman. This ROC curve fitted the data better than average sensitivity and specificity values in each of four subsets of the data. For the subset dealing with Tc-99m sulfur colloid scintigraphy, performed for detection of suspected metastases and containing data on 2800 scans from 17 independent series, it was not possible to reject the hypothesis that interobserver variation was entirely due to the use of different decision thresholds by the reporting clinicians. Thus the ROC curve obtained is a reasonable baseline estimate of the performance potentially achievable in today's clinical setting. Comparison of new reports with these data is impossible, but is limited by the small sample sizes in most reported series

  18. ROC analysis of diagnostic performance in liver scintigraphy.

    Science.gov (United States)

    Fritz, S L; Preston, D F; Gallagher, J H

    1981-02-01

    Studies on the accuracy of liver scintigraphy for the detection of metastases were assembled from 38 sources in the medical literature. An ROC curve was fitted to the observed values of sensitivity and specificity using an algorithm developed by Ogilvie and Creelman. This ROC curve fitted the data better than average sensitivity and specificity values in each of four subsets of the data. For the subset dealing with Tc-99m sulfur colloid scintigraphy, performed for detection of suspected metastases and containing data on 2800 scans from 17 independent series, it was not possible to reject the hypothesis that interobserver variation was entirely due to the use of different decision thresholds by the reporting clinicians. Thus the ROC curve obtained is a reasonable baseline estimate of the performance potentially achievable in today's clinical setting. Comparison of new reports with these data is possible, but is limited by the small sample sizes in most reported series.

  19. Thermal diagnostics in power plant to improve performance

    International Nuclear Information System (INIS)

    Meister, H.

    1995-01-01

    The improvement of older power plants by changing poor performing components is a cost effective method to increase the capacity of the units. The necessary information for the detection of components that are to be replaced can be obtained from heat rate and component tests with accuracy instrumentation. The discussed methods and tools provided by ABB Were used with success in several power plants in Europe. These tools are in the process of permanent improvement and can be used in almost any type of power plant. Due to the reasons discussed above, there is a high potential for improvement of a lot of power plants in the next decade. (author)

  20. Thyroid Ultrasound: Change of Inter-observer Variability and Diagnostic Performance after Training

    International Nuclear Information System (INIS)

    Moon, Hee Jung; Kim, Eun Kyung; Kwak, Jin Young; Park, Jeong Seon

    2011-01-01

    To investigate and compare inter-observer variability and diagnostic performance of thyroid ultrasound (US) between a faculty member and observing residents. From October 2007 to June 2009, 18 residents underwent training in thyroid US section. Group 1 included 8 residents that were trained for the first time and group 2 included 10 residents that were trained for the second time. US features of nodules were recorded according to the composition, echogenicity, margin, calcifications, shape, and final assessment by a faculty member and residents, respectively. Following a discussion, a faculty member performed fine needle aspiration. Then, the inter-observer variability and diagnostic performance between a faculty member and residents were investigated and compared for US. In group 1, agreement for composition in resident 1, calcification for residents 5 and 6, and shape for resident 4 were slight, moderate, moderate, and moderate, respectively. In group 2, agreement for composition in residents 1 and 10 were moderate. Substantial or greater agreement was observed more frequently in group 2 than 1. The diagnostic performances for both the faculty and residents were high and not statistically different. Agreement for US features between a faculty and residents as well as diagnostic performance were high. Moreover, diagnostic performance of residents that underwent training a second time of training was higher than residents that underwent training only once

  1. Evaluation Of The Diagnostic Performance Of A Multimedia Medical Communications System.

    Science.gov (United States)

    Robertson, John G.; Coristine, Marjorie; Goldberg, Morris; Beeton, Carolyn; Belanger, Garry; Tombaugh, Jo W.; Hickey, Nancy M.; Millward, Steven F.; Davis, Michael; Whittingham, David

    1989-05-01

    The central concern of radiologists when evaluating Picture Archiving Communication System (PACS) is the diagnostic performance of digital images compared to the original analog versions of the same images. Considerable work has been done comparing the ROC curves of various types of digital systems to the corresponding analog systems for the detection of specific phantoms or diseases. Although the studies may notify the radiologists that for a specific lesion a digital system may perform as well as the analog system, it tells the radiologists very little about the impact on diagnostic performance of a digital system in the general practice of radiology. We describe in this paper an alternative method for evaluating the diagnostic performance of a digital system and a preliminary experiment we conducted to test the methodology.

  2. Effective exposure level and diagnostic performance in endodontic radiography

    International Nuclear Information System (INIS)

    Okano, T.; Wiebe, J.D.; Webber, R.L.; Wagner, R.F.

    1983-01-01

    Image quality is limited by the information capacity of the image-forming system and can be computed from three parameters: contrast, resolution, and noise. These parameters can be combined to yield a single measure which determines the maximum amount of information obtainable from any x-ray system and is called the noise-equivalent number of quanta (NEQ) per unit area. The effects of image quality, expressed as noise-equivalent number of quanta (NEQ) per unit area, on the radiographic performance by dentists reading the position of an endodontic file in a root canal were studied. Three different speed films were used in conjunction with a fixed screen. Components of variance associated with the position of the tooth apex and the tip of an endodontic file in a root canal were compared for the effect of different NEQs and observers. Results show that the standard deviation in locating a file tip and tooth apex may be a linear function of log NEQ. These findings indicate that a significant reduction in exposure would have a relatively small effect on the precision of endodontic distance measurements

  3. Exploring the Knowledge Management Index as a Performance Diagnostic Tool

    Directory of Open Access Journals (Sweden)

    Jakov Crnkovic

    2005-04-01

    Full Text Available The knowledge management index (KMI has been proposed as a parsimonious and useful tool to help organizations gauge their knowledge management (KM capabilities. This may be the first step in understanding the difference between what an organization is currently doing and what it needs to do in order to maintain and improve its performance level. At the macro level, the index enables organizations to compare themselves with each other. At the micro level, it calls attention to areas needing improvement in current and future KM initiatives. In either case, the KMI provides a robust indicator and basis for business decision-making and organizational support and development. This paper presents a holistic approach to KM that relates key knowledge management processes (KMP and critical success factors (CSF needed to successfully implement it. By juxtaposing these processes and success factors, we create Belardo's matrix that will enable us to characterize an organization and estimate the KMI. At the macro level, we used realized KMI values and OP estimates to confirm the positive correlation between the KMI and OP. Additional findings include comparing the current and expected role of KM in organizations and discussion for marginal values of rows (CSF and columns (KM Processes of the proposed matrix.

  4. Gas monitoring onboard ISS using FTIR spectroscopy

    Science.gov (United States)

    Gisi, Michael; Stettner, Armin; Seurig, Roland; Honne, Atle; Witt, Johannes; Rebeyre, Pierre

    2017-06-01

    In the confined, enclosed environment of a spacecraft, the air quality must be monitored continuously in order to safeguard the crew's health. For this reason, OHB builds the ANITA2 (Analysing Interferometer for Ambient Air) technology demonstrator for trace gas monitoring onboard the International Space Station (ISS). The measurement principle of ANITA2 is based on the Fourier Transform Infrared (FTIR) technology with dedicated gas analysis software from the Norwegian partner SINTEF. This combination proved to provide high sensitivity, accuracy and precision for parallel measurements of 33 trace gases simultaneously onboard ISS by the precursor instrument ANITA1. The paper gives a technical overview about the opto-mechanical components of ANITA2, such as the interferometer, the reference Laser, the infrared source and the gas cell design and a quick overview about the gas analysis. ANITA2 is very well suited for measuring gas concentrations specifically but not limited to usage onboard spacecraft, as no consumables are required and measurements are performed autonomously. ANITA2 is a programme under the contract of the European Space Agency, and the air quality monitoring system is a stepping stone into the future, as a precursor system for manned exploration missions.

  5. A systematic review of the diagnostic performance of orthopedic physical examination tests of the hip.

    Science.gov (United States)

    Rahman, Labib Ataur; Adie, Sam; Naylor, Justine Maree; Mittal, Rajat; So, Sarah; Harris, Ian Andrew

    2013-08-30

    Previous reviews of the diagnostic performances of physical tests of the hip in orthopedics have drawn limited conclusions because of the low to moderate quality of primary studies published in the literature. This systematic review aims to build on these reviews by assessing a broad range of hip pathologies, and employing a more selective approach to the inclusion of studies in order to accurately gauge diagnostic performance for the purposes of making recommendations for clinical practice and future research. It specifically identifies tests which demonstrate strong and moderate diagnostic performance. A systematic search of Medline, Embase, Embase Classic and CINAHL was conducted to identify studies of hip tests. Our selection criteria included an analysis of internal and external validity. We reported diagnostic performance in terms of sensitivity, specificity, predictive values and likelihood ratios. Likelihood ratios were used to identify tests with strong and moderate diagnostic utility. Only a small proportion of tests reported in the literature have been assessed in methodologically valid primary studies. 16 studies were included in our review, producing 56 independent test-pathology combinations. Two tests demonstrated strong clinical utility, the patellar-pubic percussion test for excluding radiologically occult hip fractures (negative LR 0.05, 95% Confidence Interval [CI] 0.03-0.08) and the hip abduction sign for diagnosing sarcoglycanopathies in patients with known muscular dystrophies (positive LR 34.29, 95% CI 10.97-122.30). Fifteen tests demonstrated moderate diagnostic utility for diagnosing and/or excluding hip fractures, symptomatic osteoarthritis and loosening of components post-total hip arthroplasty. We have identified a number of tests demonstrating strong and moderate diagnostic performance. These findings must be viewed with caution as there are concerns over the methodological quality of the primary studies from which we have extracted our

  6. The diagnostic performance of imaging methods in ARVC using the 2010 Task Force criteria

    DEFF Research Database (Denmark)

    Borgquist, Rasmus; Haugaa, Kristina H; Gilljam, Thomas

    2014-01-01

    , fractional area shortening 31 ± 9 vs. 39 ± 9% (P performance was low; sensitivity 50% and specificity 70%, positive predictive value 80% and negative predictive value 37...... evaluation of subtle structural changes in the right ventricle may be unreliable, and the diagnostic performance of CMR compared with echocardiography should be reflected in the guidelines....

  7. Diagnostic Performance of the Intraoral Radiographs on the Interproximal Dental Caries

    International Nuclear Information System (INIS)

    Kim, Soo Ji; Kang, Byung Cheol

    1998-01-01

    The purpose of this study was to evaluated the diagnostic performance of the senior dental students for the proximal dental caries in intraoral radiographs and to compare it with the dental hospital residents, the reference group. It was also investigated the diagnostic performance according to the carious lesion depth. Thirty-five intraoral periapical and bitewing radiographs with 213 proximal surface included in this study were selected from the dental patients at Chonnam National University Hospital. The observers were 181 senior dental students from 5 dental schools and 40 dentists who were second year resident from 5 dental hospitals. They were asked to evaluate the presence ro the absence of the proximal dental caries. The results were as follows : 1. The mean of the hitting rate for the overall observers was 184.51 surfaces and the diagnostic accuracy was 86.62%. 2. The diagnostic performance of the sound proximal tooth surfaces was very high, i.e., 91.5% true negative rate and 8.5% false positive rate. 3. The diagnostic performance of the dentist group was higher than the student group (P 0.001).

  8. Quantitative evaluation of visual detection performance in medicine: ROC analysis and determination of diagnostic benefit

    International Nuclear Information System (INIS)

    Metz, C.E.; Starr, S.J.; Lusted, L.B.

    1976-01-01

    An ROC curve provides an empirical description of the trade-offs which are possible among the various types of correct and incorrect decisions as the human decision-maker varies one or more confidence thresholds. Conventional ROC curves measured in simple decision-making situations can, in some cases, be used to predict human decision performance in more complex situations. By considering both the consequences of the various types of diagnostic decisions and the overhead cost of a diagnostic study, one can use the ROC curve to evaluate the diagnostic usefulness of a study in any particular clinical context. Since the ROC curve describes the possible relationships among the probabilities of the various types of correct and incorrect decisions, it plays a central role in optimizing diagnostic strategies using the general techniques of decision analysis. Applications in radiographic image evaluation are described

  9. A Hybrid Neural Network-Genetic Algorithm Technique for Aircraft Engine Performance Diagnostics

    Science.gov (United States)

    Kobayashi, Takahisa; Simon, Donald L.

    2001-01-01

    In this paper, a model-based diagnostic method, which utilizes Neural Networks and Genetic Algorithms, is investigated. Neural networks are applied to estimate the engine internal health, and Genetic Algorithms are applied for sensor bias detection and estimation. This hybrid approach takes advantage of the nonlinear estimation capability provided by neural networks while improving the robustness to measurement uncertainty through the application of Genetic Algorithms. The hybrid diagnostic technique also has the ability to rank multiple potential solutions for a given set of anomalous sensor measurements in order to reduce false alarms and missed detections. The performance of the hybrid diagnostic technique is evaluated through some case studies derived from a turbofan engine simulation. The results show this approach is promising for reliable diagnostics of aircraft engines.

  10. Arctic summer school onboard an icebreaker

    Science.gov (United States)

    Alexeev, Vladimir A.; Repina, Irina A.

    2014-05-01

    The International Arctic Research Center (IARC) of the University of Alaska Fairbanks conducted a summer school for PhD students, post-docs and early career scientists in August-September 2013, jointly with an arctic expedition as a part of NABOS project (Nansen and Amundsen Basin Observational System) onboard the Russian research vessel "Akademik Fedorov". Both the summer school and NABOS expedition were funded by the National Science Foundation. The one-month long summer school brought together graduate students and young scientists with specialists in arctic oceanography and climate to convey to a new generation of scientists the opportunities and challenges of arctic climate observations and modeling. Young scientists gained hands-on experience during the field campaign and learned about key issues in arctic climate from observational, diagnostic, and modeling perspectives. The summer school consisted of background lectures, participation in fieldwork and mini-projects. The mini-projects were performed in collaboration with summer school instructors and members of the expedition. Key topics covered in the lectures included: - arctic climate: key characteristics and processes; - physical processes in the Arctic Ocean; - sea ice and the Arctic Ocean; - trace gases, aerosols, and chemistry: importance for climate changes; - feedbacks in the arctic system (e.g., surface albedo, clouds, water vapor, circulation); - arctic climate variations: past, ongoing, and projected; - global climate models: an overview. An outreach specialist from the Miami Science Museum was writing a blog from the icebreaker with some very impressive statistics (results as of January 1, 2014): Total number of blog posts: 176 Blog posts written/contributed by scientists: 42 Blog views: 22,684 Comments: 1,215 Number of countries who viewed the blog: 89 (on 6 continents) The 33-day long NABOS expedition started on August 22, 2013 from Kirkenes, Norway. The vessel ("Akademik Fedorov") returned to

  11. Social anxiety disorder diagnostic criteria perform equally across age, comorbid diagnosis, and performance/interaction subtypes.

    Science.gov (United States)

    Crome, Erica; Baillie, Andrew

    2015-01-01

    The prevalence of social anxiety disorder (SAD) is frequently higher in younger age groups and people with other anxiety or mood disorders; however, it is unclear whether these groups have a higher risk for developing SAD or are simply more likely to endorse diagnostic criteria than other people with similar levels of social anxiety. Explicitly testing the assumption all people respond to structured diagnostic interviews in comparable ways (measurement invariance) is essential in ensuring systematic response biases do not create spurious group differences. This research aims to systematically test whether age, comorbidity status, or types of social fears affect responses to a structured diagnostic interview. Responses from 1755 participants in a large-scale survey of mental health in Australia screening into the social phobia/SAD section of the Composite International Diagnostic Interview were used. Three series of multigroup confirmatory factor analyses for categorical data systematically tested for increasingly strict levels of measurement invariance. Overall, patterns of responding to diagnostic criteria were comparable across the groups, supporting assumptions of measurement invariance. Establishment of invariance supports the interpretation of differences between age, comorbidity status, and types of social situations feared as genuine differences in experience as opposed to measurement biases.

  12. Study on Fault Diagnostics of a Turboprop Engine Using Inverse Performance Model and Artificial Intelligent Methods

    Science.gov (United States)

    Kong, Changduk; Lim, Semyeong

    2011-12-01

    Recently, the health monitoring system of major gas path components of gas turbine uses mostly the model based method like the Gas Path Analysis (GPA). This method is to find quantity changes of component performance characteristic parameters such as isentropic efficiency and mass flow parameter by comparing between measured engine performance parameters such as temperatures, pressures, rotational speeds, fuel consumption, etc. and clean engine performance parameters without any engine faults which are calculated by the base engine performance model. Currently, the expert engine diagnostic systems using the artificial intelligent methods such as Neural Networks (NNs), Fuzzy Logic and Genetic Algorithms (GAs) have been studied to improve the model based method. Among them the NNs are mostly used to the engine fault diagnostic system due to its good learning performance, but it has a drawback due to low accuracy and long learning time to build learning data base if there are large amount of learning data. In addition, it has a very complex structure for finding effectively single type faults or multiple type faults of gas path components. This work builds inversely a base performance model of a turboprop engine to be used for a high altitude operation UAV using measured performance data, and proposes a fault diagnostic system using the base engine performance model and the artificial intelligent methods such as Fuzzy logic and Neural Network. The proposed diagnostic system isolates firstly the faulted components using Fuzzy Logic, then quantifies faults of the identified components using the NN leaned by fault learning data base, which are obtained from the developed base performance model. In leaning the NN, the Feed Forward Back Propagation (FFBP) method is used. Finally, it is verified through several test examples that the component faults implanted arbitrarily in the engine are well isolated and quantified by the proposed diagnostic system.

  13. Onboard Autonomous Corrections for Accurate IRF Pointing.

    Science.gov (United States)

    Jorgensen, J. L.; Betto, M.; Denver, T.

    2002-05-01

    Over the past decade, the Noise Equivalent Angle (NEA) of onboard attitude reference instruments, has decreased from tens-of-arcseconds to the sub-arcsecond level. This improved performance is partly due to improved sensor-technology with enhanced signal to noise ratios, partly due to improved processing electronics which allows for more sophisticated and faster signal processing. However, the main reason for the increased precision, is the application of onboard autonomy, which apart from simple outlier rejection also allows for removal of "false positive" answers, and other "unexpected" noise sources, that otherwise would degrade the quality of the measurements (e.g. discrimination between signals caused by starlight and ionizing radiation). The utilization of autonomous signal processing has also provided the means for another onboard processing step, namely the autonomous recovery from lost in space, where the attitude instrument without a priori knowledge derive the absolute attitude, i.e. in IRF coordinates, within fractions of a second. Combined with precise orbital state or position data, the absolute attitude information opens for multiple ways to improve the mission performance, either by reducing operations costs, by increasing pointing accuracy, by reducing mission expendables, or by providing backup decision information in case of anomalies. The Advanced Stellar Compass's (ASC) is a miniature, high accuracy, attitude instrument which features fully autonomous operations. The autonomy encompass all direct steps from automatic health checkout at power-on, over fully automatic SEU and SEL handling and proton induced sparkle removal, to recovery from "lost in space", and optical disturbance detection and handling. But apart from these more obvious autonomy functions, the ASC also features functions to handle and remove the aforementioned residuals. These functions encompass diverse operators such as a full orbital state vector model with automatic cloud

  14. Effect of radiologists' diagnostic work-up volume on interpretive performance.

    Science.gov (United States)

    Buist, Diana S M; Anderson, Melissa L; Smith, Robert A; Carney, Patricia A; Miglioretti, Diana L; Monsees, Barbara S; Sickles, Edward A; Taplin, Stephen H; Geller, Berta M; Yankaskas, Bonnie C; Onega, Tracy L

    2014-11-01

    To examine radiologists' screening performance in relation to the number of diagnostic work-ups performed after abnormal findings are discovered at screening mammography by the same radiologist or by different radiologists. In an institutional review board-approved HIPAA-compliant study, the authors linked 651 671 screening mammograms interpreted from 2002 to 2006 by 96 radiologists in the Breast Cancer Surveillance Consortium to cancer registries (standard of reference) to evaluate the performance of screening mammography (sensitivity, false-positive rate [ FPR false-positive rate ], and cancer detection rate [ CDR cancer detection rate ]). Logistic regression was used to assess the association between the volume of recalled screening mammograms ("own" mammograms, where the radiologist who interpreted the diagnostic image was the same radiologist who had interpreted the screening image, and "any" mammograms, where the radiologist who interpreted the diagnostic image may or may not have been the radiologist who interpreted the screening image) and screening performance and whether the association between total annual volume and performance differed according to the volume of diagnostic work-up. Annually, 38% of radiologists performed the diagnostic work-up for 25 or fewer of their own recalled screening mammograms, 24% performed the work-up for 0-50, and 39% performed the work-up for more than 50. For the work-up of recalled screening mammograms from any radiologist, 24% of radiologists performed the work-up for 0-50 mammograms, 32% performed the work-up for 51-125, and 44% performed the work-up for more than 125. With increasing numbers of radiologist work-ups for their own recalled mammograms, the sensitivity (P = .039), FPR false-positive rate (P = .004), and CDR cancer detection rate (P women recalled per cancer detected from 17.4 for 25 or fewer mammograms to 24.6 for more than 50 mammograms. Increases in work-ups for any radiologist yielded significant

  15. Effect of Radiologists’ Diagnostic Work-up Volume on Interpretive Performance

    Science.gov (United States)

    Anderson, Melissa L.; Smith, Robert A.; Carney, Patricia A.; Miglioretti, Diana L.; Monsees, Barbara S.; Sickles, Edward A.; Taplin, Stephen H.; Geller, Berta M.; Yankaskas, Bonnie C.; Onega, Tracy L.

    2014-01-01

    Purpose To examine radiologists’ screening performance in relation to the number of diagnostic work-ups performed after abnormal findings are discovered at screening mammography by the same radiologist or by different radiologists. Materials and Methods In an institutional review board–approved HIPAA-compliant study, the authors linked 651 671 screening mammograms interpreted from 2002 to 2006 by 96 radiologists in the Breast Cancer Surveillance Consortium to cancer registries (standard of reference) to evaluate the performance of screening mammography (sensitivity, false-positive rate [FPRfalse-positive rate], and cancer detection rate [CDRcancer detection rate]). Logistic regression was used to assess the association between the volume of recalled screening mammograms (“own” mammograms, where the radiologist who interpreted the diagnostic image was the same radiologist who had interpreted the screening image, and “any” mammograms, where the radiologist who interpreted the diagnostic image may or may not have been the radiologist who interpreted the screening image) and screening performance and whether the association between total annual volume and performance differed according to the volume of diagnostic work-up. Results Annually, 38% of radiologists performed the diagnostic work-up for 25 or fewer of their own recalled screening mammograms, 24% performed the work-up for 0–50, and 39% performed the work-up for more than 50. For the work-up of recalled screening mammograms from any radiologist, 24% of radiologists performed the work-up for 0–50 mammograms, 32% performed the work-up for 51–125, and 44% performed the work-up for more than 125. With increasing numbers of radiologist work-ups for their own recalled mammograms, the sensitivity (P = .039), FPRfalse-positive rate (P = .004), and CDRcancer detection rate (P work-ups for any radiologist yielded significant increases in FPRfalse-positive rate (P = .011) and CDRcancer detection rate (P

  16. Performance Evaluation of Commercial Dengue Diagnostic Tests for Early Detection of Dengue in Clinical Samples

    Directory of Open Access Journals (Sweden)

    Tuan Nur Akmalina Mat Jusoh

    2017-01-01

    Full Text Available The shattering rise in dengue virus infections globally has created a need for an accurate and validated rapid diagnostic test for this virus. Rapid diagnostic test (RDT and reverse transcription-polymerase chain reaction (RT-PCR diagnostic detection are useful tools for diagnosis of early dengue infection. We prospectively evaluated the diagnostic performance of nonstructural 1 (NS1 RDT and real-time RT-PCR diagnostic kits in 86 patient serum samples. Thirty-six samples were positive for dengue NS1 antigen while the remaining 50 were negative when tested with enzyme-linked immunosorbent assay (ELISA. Commercially available RDTs for NS1 detection, RTK ProDetect™, and SD Bioline showed high sensitivity of 94% and 89%, respectively, compared with ELISA. GenoAmp® Trioplex Real-Time RT-PCR and RealStar® Dengue RT-PCR tests presented a comparable kappa agreement with 0.722. The result obtained from GenoAmp® Real-Time RT-PCR Dengue test showed that 14 samples harbored dengue virus type 1 (DENV-1, 8 samples harbored DENV-2, 2 samples harbored DENV-3, and 1 sample harbored DENV-4. 1 sample had a double infection with DENV-1 and DENV-2. The NS1 RDTs and real-time RT-PCR tests were found to be a useful diagnostic for early and rapid diagnosis of acute dengue and an excellent surveillance tool in our battle against dengue.

  17. Performance of diagnostic mammography differs in the United States and Denmark

    DEFF Research Database (Denmark)

    Jensen, Allan; Geller, Berta M; Gard, Charlotte C

    2010-01-01

    in the United States and Denmark. The performance of 93,585 diagnostic mammograms from 180 facilities contributing data to the US Breast Cancer Surveillance Consortium (BCSC) from 1999 to 2001 was compared to that of all 51,313 diagnostic mammograms performed at Danish clinics in 2000. We used the imaging...... workup's final assessment to determine sensitivity, specificity and an estimate of accuracy: area under the receiver-operating characteristics (ROCs) curve (AUC). Diagnostic mammography had slightly higher sensitivity in the United States (85%) than in Denmark (82%). In contrast, it had higher...... specificity in Denmark (99%) than in the United States (93%). The AUC was high in both countries: 0.91 in United States and 0.95 in Denmark. Denmark's higher accuracy may result from supplementary ultrasound examinations, which are provided to 74% of Danish women but only 37% to 52% of US women. In addition...

  18. Systematic reviews of diagnostic tests in endocrinology: an audit of methods, reporting, and performance.

    Science.gov (United States)

    Spencer-Bonilla, Gabriela; Singh Ospina, Naykky; Rodriguez-Gutierrez, Rene; Brito, Juan P; Iñiguez-Ariza, Nicole; Tamhane, Shrikant; Erwin, Patricia J; Murad, M Hassan; Montori, Victor M

    2017-07-01

    Systematic reviews provide clinicians and policymakers estimates of diagnostic test accuracy and their usefulness in clinical practice. We identified all available systematic reviews of diagnosis in endocrinology, summarized the diagnostic accuracy of the tests included, and assessed the credibility and clinical usefulness of the methods and reporting. We searched Ovid MEDLINE, EMBASE, and Cochrane CENTRAL from inception to December 2015 for systematic reviews and meta-analyses reporting accuracy measures of diagnostic tests in endocrinology. Experienced reviewers independently screened for eligible studies and collected data. We summarized the results, methods, and reporting of the reviews. We performed subgroup analyses to categorize diagnostic tests as most useful based on their accuracy. We identified 84 systematic reviews; half of the tests included were classified as helpful when positive, one-fourth as helpful when negative. Most authors adequately reported how studies were identified and selected and how their trustworthiness (risk of bias) was judged. Only one in three reviews, however, reported an overall judgment about trustworthiness and one in five reported using adequate meta-analytic methods. One in four reported contacting authors for further information and about half included only patients with diagnostic uncertainty. Up to half of the diagnostic endocrine tests in which the likelihood ratio was calculated or provided are likely to be helpful in practice when positive as are one-quarter when negative. Most diagnostic systematic reviews in endocrine lack methodological rigor, protection against bias, and offer limited credibility. Substantial efforts, therefore, seem necessary to improve the quality of diagnostic systematic reviews in endocrinology.

  19. Diagnostic performance of traditional hepatobiliary biomarkers of drug-induced liver injury in the rat.

    Science.gov (United States)

    Ennulat, Daniela; Magid-Slav, Michal; Rehm, Sabine; Tatsuoka, Kay S

    2010-08-01

    Nonclinical studies provide the opportunity to anchor biochemical with morphologic findings; however, liver injury is often complex and heterogeneous, confounding the ability to relate biochemical changes with specific patterns of injury. The aim of the current study was to compare diagnostic performance of hepatobiliary markers for specific manifestations of drug-induced liver injury in rat using data collected in a recent hepatic toxicogenomics initiative in which rats (n = 3205) were given 182 different treatments for 4 or 14 days. Diagnostic accuracy of alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (Tbili), serum bile acids (SBA), alkaline phosphatase (ALP), gamma glutamyl transferase (GGT), total cholesterol (Chol), and triglycerides (Trig) was evaluated for specific types of liver histopathology by Receiver Operating Characteristic (ROC) analysis. To assess the relationship between biochemical and morphologic changes in the absence of hepatocellular necrosis, a second ROC analysis was performed on a subset of rats (n = 2504) given treatments (n = 152) that did not cause hepatocellular necrosis. In the initial analysis, ALT, AST, Tbili, and SBA had the greatest diagnostic utility for manifestations of hepatocellular necrosis and biliary injury, with comparable magnitude of area under the ROC curve and serum hepatobiliary marker changes for both. In the absence of hepatocellular necrosis, ALT increases were observed with biochemical or morphologic evidence of cholestasis. In both analyses, diagnostic utility of ALP and GGT for biliary injury was limited; however, ALP had modest diagnostic value for peroxisome proliferation, and ALT, AST, and total Chol had moderate diagnostic utility for phospholipidosis. None of the eight markers evaluated had diagnostic value for manifestations of hypertrophy, cytoplasmic rarefaction, inflammation, or lipidosis.

  20. Diagnostic performance of CT angiography in patients visiting emergency department with overt gastrointestinal bleeding

    International Nuclear Information System (INIS)

    Kim, Ji Hang; Kim, Young Hoon; Lee, Kyoung Ho; Lee, Yoon Jin; Park, Ji Hoon

    2015-01-01

    To investigate the diagnostic performance of computed tomography angiography (CTA) in identifying the cause of bleeding and to determine the clinical features associated with a positive test result of CTA in patients visiting emergency department with overt gastrointestinal (GI) bleeding. We included 111 consecutive patients (61 men and 50 women; mean age: 63.4 years; range: 28-89 years) who visited emergency department with overt GI bleeding. They underwent CTA as a first-line diagnostic modality from July through December 2010. Two radiologists retrospectively reviewed the CTA images and determined the presence of any definite or potential bleeding focus by consensus. An independent assessor determined the cause of bleeding based on other diagnostic studies and/or clinical follow-up. The diagnostic performance of CTA and clinical characteristics associated with positive CTA results were analyzed. To identify a definite or potential bleeding focus, the diagnostic yield of CTA was 61.3% (68 of 111). The overall sensitivity, specificity, positive predictive value (PPV), and negative predictive value were 84.8% (67 of 79), 96.9% (31 of 32), 98.5% (67 of 68), and 72.1% (31 of 43), respectively. Positive CTA results were associated with the presence of massive bleeding (p = 0.001, odds ratio: 11.506). Computed tomography angiography as a first-line diagnostic modality in patients presenting with overt GI bleeding showed a fairly high accuracy. It could identify definite or potential bleeding focus with a moderate diagnostic yield and a high PPV. CTA is particularly useful in patients with massive bleeding.

  1. Diagnostic performance of 64-slice multidetector coronary computed tomographic angiography in women.

    Science.gov (United States)

    Jug, Borut; Gupta, Mohit; Papazian, Jenny; Li, Dong; Tsang, Janet; Bhatia, Harpreet; Karlsberg, Ronald; Budoff, Matthew

    2012-12-01

    Diagnostic approach to chest pain in women is challenging, but still under-investigated. The purpose of this study was to assess the diagnostic performance of 64-slice multidetector coronary computed tomographic angiography (CCTA) in women with chest pain. We included 606 patients--255 women and 351 men (mean age 61 ± 12 years for both)--who had been referred for a CCTA and an invasive coronary angiography (diagnostic standard) because of chest pain, either as part of clinical work-up in two urban medical centers or as part of the multicenter ACCURACY trial. On a patient-based model, the sensitivity, specificity, and positive predictive value (PPV) and negative predictive value to detect ≥50% and ≥70% stenosis were 98%, 84%, 87%, and 97% and 96%, 83%, 77%, and 97%, respectively, for women and 97%, 83%, 89%, and 95% and 94%, 91%, 90%, and 94%, respectively, for men. There were no statistically significant differences between men and women in diagnostic performance measures except for the PPV of detecting a ≥70% stenosis (P = .007). In women with chest pain, 64-slice multidetector CCTA is at least as sensitive and specific as in men. Our findings suggest that CCTA is a promising diagnostic tool for timely detection and/or exclusion of CAD in symptomatic intermediate-risk female populations.

  2. Towards Modernizing the Characterization of Shock and Detonation Physics Performance via Novel Diagnostics and Tests

    Science.gov (United States)

    Salyer, Terry

    2017-06-01

    For the bulk of detonation performance experiments, a fairly basic set of diagnostic techniques has evolved as the standard for acquiring the necessary measurements. Gold standard techniques such as pin switches and streak cameras still produce the high-quality data required, yet much room remains for improvement with regard to ease of use, cost of fielding, breadth of data, and diagnostic versatility. Over the past several years, an alternate set of diagnostics has been under development to replace many of these traditional techniques. Pulse Correlation Reflectometry (PCR) is a capable substitute for pin switches with the advantage of obtaining orders of magnitude more data at a small fraction of the cost and fielding time. Spectrally Encoded Imaging (SEI) can replace most applications of streak camera with the advantage of imaging surfaces through a single optical fiber that are otherwise optically inaccessible. Such diagnostics advance the measurement state of the art, but even further improvements may come through revamping the standardized tests themselves such as the copper cylinder expansion test. At the core of this modernization, the aforementioned diagnostics play a significant role in revamping and improving the standard test suite for the present era. This research was performed under the auspices of the United States Department of Energy.

  3. On-Board Rendezvous Targeting for Orion

    Science.gov (United States)

    Weeks, Michael W.; DSouza, Christopher N.

    2010-01-01

    The Orion On-board GNC system is among the most complex ever developed for a space mission. It is designed to operate autonomously (independent of the ground). The rendezvous system in particular was designed to operate on the far side of the moon, and in the case of loss-of-communications with the ground. The vehicle GNC system is designed to retarget the rendezvous maneuvers, given a mission plan. As such, all the maneuvers which will be performed by Orion, have been designed and are being incorporated into the flight code.

  4. Low cut-off values increase diagnostic performance of protein S assays

    NARCIS (Netherlands)

    Mulder, Rene; ten Kate, Min Ki; Kluin-Nelemans, Hanneke C.; Mulder, Andre B.

    Conflicting data have been reported on the accuracy of protein S (PS) assays for detection of hereditary PS deficiency. In this study we assessed the diagnostic performance of two total PS antigen assays, four free PS assays and three PS activity assays in a group of 28 heterozygous carriers of

  5. Development of high performance Schottky barrier diode and its application to plasma diagnostics

    International Nuclear Information System (INIS)

    Fujita, Junji; Kawahata, Kazuo; Okajima, Shigeki

    1993-10-01

    At the conclusion of the Supporting Collaboration Research on 'Development of High Performance Detectors in the Far Infrared Range' carried out from FY1990 to FY1992, the results of developing Schottky barrier diode and its application to plasma diagnostics are summarized. Some remarks as well as technical know-how for the correct use of diodes are also described. (author)

  6. Diagnostic Utility of the Social Skills Improvement System Performance Screening Guide

    Science.gov (United States)

    Krach, S. Kathleen; McCreery, Michael P.; Wang, Ye; Mohammadiamin, Houra; Cirks, Christen K.

    2017-01-01

    Researchers investigated the diagnostic utility of the Social Skills Improvement System: Performance Screening Guide (SSIS-PSG). Correlational, regression, receiver operating characteristic (ROC), and conditional probability analyses were run to compare ratings on the SSIS-PSG subscales of Prosocial Behavior, Reading Skills, and Math Skills, to…

  7. Diagnostic Performance on Low Dose Computed Tomography For Acute Appendicitis Among Attending and Resident Radiologists

    International Nuclear Information System (INIS)

    Chang, Chih-Chen; Wong, Yon-Cheong; Wu, Cheng-Hsien; Chen, Huan-Wu; Wang, Li-Jen; Lee, Yu-Hsien; Wu, Patricia Wanping; Irama, Wiwan; Chen, Wei Yuan; Chang, Chee-Jen

    2016-01-01

    Low-dose computed tomography (LDCT) techniques can reduce exposure to radiation. Several previous studies have shown that radiation dose reduction in LDCT does not decrease the diagnostic performance for appendicitis among attending radiologists. But, the LDCT diagnostic performance for acute appendicitis in radiology residents with variable training levels has not been well discussed. To compare inter-observer and intra-observer differences of diagnostic performance on non-enhanced LDCT (NE-LDCT) and contrast-enhanced standard dose CT (CE-SDCT) for acute appendicitis among attending and resident radiologists. This retrospective study included 101 patients with suspected acute appendicitis who underwent NE-LDCT and CE-SDCT. The CT examinations were interpreted and recorded on a five-point scale independently by three attending radiologists and three residents with 4, 1 and 1 years of training. Diagnostic performance for acute appendicitis of all readers on both examinations was represented by area under receiver operating characteristic (ROC) curves. Inter-observer and intra-observer AUC values were compared using Jackknife FROC software on both modalities. The diagnostic accuracy of each reader on NE-LDCT was compared with body mass index (BMI) subgroups and noise using independent T test. Diagnostic performances for acute appendicitis were not statistically different for attending radiologists at both examinations. Better performance was noted on the CE-SDCT with a borderline significant difference (P = 0.05) for senior radiology resident. No statistical difference of AUC values was observed between attending radiologists and fourth year resident on both examinations. Statistically signifi@@cant differences of AUC values were observed between attending radiologists and first year residents (P = 0.001 ~ 0.018) on NE-LDCT. Diagnostic accuracies of acute appendicitis on NE-LDCT for each reader were not significantly related to BMI or noise. Attending radiologists

  8. Poor academic performance: A perspective of final year diagnostic radiography students

    International Nuclear Information System (INIS)

    Gqweta, Ntokozo

    2012-01-01

    Introduction: A study was conducted on final year diagnostic radiography students at a University of Technology in Durban. The aim of the study was to investigate the final year diagnostic radiography students' opinions and views on academic performance in order to inform teaching and learning methods. The objectives were: •To explore the students' opinions regarding poor performance. •To identify strategies to improve academic performance. Method: A qualitative, interpretive approach was used to explain and understand the students' lived experiences of their academic performances. A short open ended questionnaire was administered to a cohort of final diagnostic radiography students following feedback on a written assessment. Questionnaire responses were then manually captured and analyzed. Results: Five (5) themes were identified that could possibly be associated with poor academic performance. These themes were, poor preparation, lack of independent study, difficulty in understanding learning content and misinterpretation of assessment questions, inefficient studying techniques as well as perceived improvement strategies. Conclusion: Students identified their inadequate preparation and the lack of dedicated independent studying as the main reasons for poor performance. Students preferred to be taught in an assessment oriented manner. However their identified improvement strategies were aligned with the learner centred approach.

  9. Diagnostic accuracy of mammography readers and their memory performance have no correlation with each other

    International Nuclear Information System (INIS)

    Kok, P.; Cawson, J.N.; Mercuri, V.; Pitman, A.G.; Gledhill, S.; Shnier, D.; Taft, R.; Zentner, L.

    2010-01-01

    Full text: The study aims to determine if any association exists between visual memory performance and diagnostic accuracy performance in a group of radiologist mammogram readers. Materials and Methods: One hundred proven mammograms (23 with cancers) were grouped into 5 sets of 20 cases, with sets being of equal difficulty. Pairs of sets were presented in 5 reads (40 cases per read, order random) to a panel of 8 radiologist readers (either present or past screening readers, with experience range from 20 years). The readers were asked to either 'clear' or 'call back' cases depending on need for further workup, and at post-baseline reads to indicate whether each case was 'new' or 'old' (i .e. remembered from prior read). Two sets were presented only at baseline (40 cases per reader), and were used to calculate the reader's false recollection rate. Three sets were repeated post-baseline once or twice (100 cases per reader). Reading conditions were standardised. Results: Memory performance differed markedly between readers. The number of correctly remembered cases (of 100 'old' cases) had a median of 10.5 and range of 0-58. The observed number of false recollections (of 40 'totally new' cases) had a median of 2 and range of 0-17. Diagnostic performance measures were mean (range): sensitivity 0.68 (0.54-0.81); specificity 0.82 (0.74-0.91); positive predictive value (PPV) 0.55 (0.500.65); negative predictive value (NPV) 0.89 (0.86-0.93) and accuracy 0.78 (0.76-0.83). Confidence intervals (CIs; 95%) for each reader overlapped for all the diagnostic parameters, indicating a lack of statistically significant difference between the readers at the 5% level. The most sensitive and the most specific reader showed a trend away from each other on sensitivity, specificity, NPV and PPV; their accuracies were 0.76 and 0.82, respectively, and their accuracy 95% CIs overlapped considerably. Correlation analysis by reader showed no association between observed memory performance and

  10. Diagnostic Performance of Narrow Band Imaging for Laryngeal Cancer: A Systematic Review and Meta-analysis.

    Science.gov (United States)

    Sun, Changling; Han, Xue; Li, Xiaoying; Zhang, Yayun; Du, Xiaodong

    2017-04-01

    Objective To evaluate the performance of narrow band imaging (NBI) for the diagnosis of laryngeal cancer and to compare the diagnostic value of NBI with that of white light endoscopy. Data Sources PubMed, Embase, Cochrane Library, and CNKI databases. Review Methods Data analyses were performed with Meta-DiSc. The updated Quality Assessment of Diagnostic Accuracy Studies-2 tool was used to assess study quality and potential bias. Publication bias was assessed with the Deeks's asymmetry test. The protocol used in this article has been published on PROSPERO and is in accordance with the PRISMA checklist. The registry number for this study is CRD42015025866. Results Six studies including 716 lesions were included in this meta-analysis. The pooled sensitivity, specificity, and diagnostic odds ratio for the NBI diagnosis of laryngeal cancer were 0.94 (95% confidence interval [95% CI]: 0.91-0.96), 0.89 (95% CI: 0.85-0.92), and 142.12 (95% CI: 46.42-435.15), respectively, and the area under receiver operating characteristics curve was 0.97. Among the 6 studies, 3 evaluated the diagnostic value of white light endoscopy, with a sensitivity of 0.81 (95% CI: 0.76-0.86), a specificity of 0.92 (95% CI: 0.88-0.95), and a diagnostic odds ratio of 33.82 (95% CI: 14.76-77.49). The evaluation of heterogeneity, calculated per the diagnostic odds ratio, gave an I 2 of 66%. No marked publication bias ( P = .84) was detected in this meta-analysis. Conclusion The sensitivity of NBI is superior to white light endoscopy, and the potential value of NBI needs to be validated in future studies.

  11. Diagnostic performance of increased overjet in Class II division 1 malocclusion and incisor trauma.

    Science.gov (United States)

    Baccetti, Tiziano; Giuntini, Veronica; Vangelisti, Andrea; Darendeliler, M Ali; Franchi, Lorenzo

    2010-01-01

    The objectives of this study were: 1) to evaluate the associations between an increased overjet (IO) and other dentoskeletal characteristics of Class II division 1 malocclusions in the mixed dentition; 2) to assess whether Class II division 1 malocclusions or rather an increased overjet per se is a risk factor for upper incisor trauma (UIT). A sample of 900 mixed dentition subjects, was observed by clinical inspection, analysis of dental casts, and lateral cephalograms. The diagnostic performance of IO (overjet ≥ 7 mm) was evaluated in relation to other Class II dentoskeletal features (Class II molar and canine relationships, and skeletal Class II relationships). Secondly, the diagnostic performance of IO and of the other Class II dentoskeletal components was tested with regard to the prevalence of UIT. Diagnostic performance was assessed by odds ratio and positive likelihood ratio. The diagnostic performance of IO with regard to the other dentoskeletal components of Class II malocclusions was not significant. The only Class II features associated significantly with an increased risk of UIT was IO. When used as an isolated occlusal feature, IO is not a valid diagnostic indicator for Class II division 1 malocclusions. An increased overjet per se, and not Class II malocclusions, appears to be a significant risk factor for UIT. These findings recommend discrimination between clinical conditions showing an isolated IO from comprehensive Class II malocclusions during diagnosis, analysis of treatment outcomes, and evaluation of the risk of upper incisor trauma. Copyright © 2010 Società Italiana di Ortodonzia SIDO. Published by Elsevier Srl. All rights reserved.

  12. Simulated and measured performance of a real-time processor for RFI detection and mitigation on-board spaceborne microwave radiometers

    DEFF Research Database (Denmark)

    Skou, Niels; Kristensen, Steen Savstrup; Søbjærg, Sten Schmidl

    2017-01-01

    An RFI processor breadboard has been designed and developed for future spaceborne microwave radiometer systems. RFI detection is based on the anomalous amplitude, kurtosis, and cross-frequency algorithms. These are implemented in VHDL code in an FPGA. Thus algorithm performance can be assessed...... by proper code simulation. The breadboard has been integrated with a Ku band radiometer subjected to RFI-like signals from a laboratory generator. Simulations show that the algorithms as implemented work according to theory when subjected to pulsed sinusoidal and QPSK signals. The laboratory measurements...

  13. Diagnostic accuracy of 201Tl SPECT·MRI in brain diseases and inter-reader variance of diagnostic performance

    International Nuclear Information System (INIS)

    Machida, Kikuo; Honda, Norinari; Matsumoto, Toru

    1996-01-01

    Fifteen-four studies of 201 Tl brain tumor SPECT were independently interpreted by 9 nuclear medicine physicians with and without reference magnetic resonance images in 2 separate sessions to define an effect of referring images, and inter-observer variations. The physicians were requested to detect foci of abnormal deposits, and to discriminate whether they were malignant or not according to 5-grade scaling of subjective diagnostic confidence. Receiver-operating characteristics (ROC) analysis was performed. Mean sensitivity for presence of lesions (SFP), and sensitivity and specificity for malignancy of 2 01 Tl SPECT were 84, and 53 and 55%, which were changed to 94 and 74 and 55% after referring to the MR images. The SFP was significantly improved (p 201 Tl brain tumor SPECT has moderate sensitivity and specificity for malignancy, which is not improved by addition of anatomical reference images, that additional MR images reduce inter-observer variation of confidence on lesion presence, and that SPECT localization of lesions has great inter-observer variations. (author)

  14. Diagnostic performance and color overlay pattern in shear wave elastography (SWE) for palpable breast mass.

    Science.gov (United States)

    Park, Jiyoon; Woo, Ok Hee; Shin, Hye Seon; Cho, Kyu Ran; Seo, Bo Kyoung; Kang, Eun Young

    2015-10-01

    The purpose of this study is to evaluate the diagnostic performance of SWE in palpable breast mass and to compare with color overlay pattern in SWE with conventional US and quantitative SWE for assessing palpable breast mass. SWE and conventional breast US were performed in 133 women with 156 palpable breast lesions (81 benign, 75 malignant) between August 2013 to June 2014. Either pathology or periodic imaging surveillance more than 2 years was a reference standard. Existence of previous image was blinded to performing radiologists. US BI-RADS final assessment, qualitative and quantitative SWE measurements were evaluated. Diagnostic performances of grayscale US, SWE and US combined to SWE were calculated and compared. Correlation between pattern classification and quantitative SWE was evaluated. Both color overlay pattern and quantitative SWE improved the specificity of conventional US, from 81.48% to 96.30% (p=0.0005), without improvement in sensitivity. Color overlay pattern was significantly related to all quantitative SWE parameters and malignancy rate (pbreast mass, conventional US combine to SWE improves specificity and reduces the number of biopsies that ultimately yield a benign result. Color overlay pattern classification is more quick and easy and may represent quantitative SWE measurements with similar diagnostic performances. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  15. Diagnostic performance of semi-quantitative and quantitative stress CMR perfusion analysis: a meta-analysis.

    Science.gov (United States)

    van Dijk, R; van Assen, M; Vliegenthart, R; de Bock, G H; van der Harst, P; Oudkerk, M

    2017-11-27

    Stress cardiovascular magnetic resonance (CMR) perfusion imaging is a promising modality for the evaluation of coronary artery disease (CAD) due to high spatial resolution and absence of radiation. Semi-quantitative and quantitative analysis of CMR perfusion are based on signal-intensity curves produced during the first-pass of gadolinium contrast. Multiple semi-quantitative and quantitative parameters have been introduced. Diagnostic performance of these parameters varies extensively among studies and standardized protocols are lacking. This study aims to determine the diagnostic accuracy of semi- quantitative and quantitative CMR perfusion parameters, compared to multiple reference standards. Pubmed, WebOfScience, and Embase were systematically searched using predefined criteria (3272 articles). A check for duplicates was performed (1967 articles). Eligibility and relevance of the articles was determined by two reviewers using pre-defined criteria. The primary data extraction was performed independently by two researchers with the use of a predefined template. Differences in extracted data were resolved by discussion between the two researchers. The quality of the included studies was assessed using the 'Quality Assessment of Diagnostic Accuracy Studies Tool' (QUADAS-2). True positives, false positives, true negatives, and false negatives were subtracted/calculated from the articles. The principal summary measures used to assess diagnostic accuracy were sensitivity, specificity, andarea under the receiver operating curve (AUC). Data was pooled according to analysis territory, reference standard and perfusion parameter. Twenty-two articles were eligible based on the predefined study eligibility criteria. The pooled diagnostic accuracy for segment-, territory- and patient-based analyses showed good diagnostic performance with sensitivity of 0.88, 0.82, and 0.83, specificity of 0.72, 0.83, and 0.76 and AUC of 0.90, 0.84, and 0.87, respectively. In per territory

  16. The diagnostic performance of chronologic age in the assessment of skeletal maturity.

    Science.gov (United States)

    Baccetti, Tiziano; Franchi, Lorenzo; De Toffol, Laura; Ghiozzi, Bruno; Cozza, Paola

    2006-01-01

    The aim of this study was to analyze the relationship between chronologic age the and individual skeletal maturity as assessed by means of the cervical vertebral maturation (CVM) method during the circumpubertal period. The evaluated sample of 600 subjects consisted of 100 subjects (50 males and 50 females) for each of 6 age groups, from 9 years through 14 years of age. Individual skeletal maturity for all subjects was determined by using the CVM method. The relationship between chronologic age and the most prevalent CVM stage at each age group was evaluated statistically by means of indicators of diagnostic test performance that specify the ability of a diagnostic test to identify a condition. The diagnostic performance of chronologic age for the detection of the onset of the adolescent peak in skeletal maturation was very low both in males and in females. In male subjects, the chronologic age of 9 years +/- 6 months presented with strong diagnostic power for the identification of a pre-pubertal stage in skeletal maturation. In female subjects, the chronologic age of 14 years +/- 6 months corresponded with a strong probability of a postpubertal stage in skeletal maturation. In males, chronologic age can identify a pre-pubertal stage of skeletal development, and in females a post-pubertal stage. In both males and females, chronologic age cannot recognize the onset of the adolescent peak in skeletal maturation.

  17. 9 CFR 130.17 - User fees for other veterinary diagnostic laboratory tests performed at NVSL (excluding FADDL) or...

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false User fees for other veterinary... FEES USER FEES § 130.17 User fees for other veterinary diagnostic laboratory tests performed at NVSL (excluding FADDL) or at authorized sites. (a) User fees for veterinary diagnostics tests performed at the...

  18. 9 CFR 130.16 - User fees for veterinary diagnostic serology tests performed at NVSL (excluding FADDL) or at...

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false User fees for veterinary diagnostic serology tests performed at NVSL (excluding FADDL) or at authorized sites. 130.16 Section 130.16 Animals... USER FEES § 130.16 User fees for veterinary diagnostic serology tests performed at NVSL (excluding...

  19. Evaluation performance of diagnostic methods of intestinal parasitosis in school age children in Ethiopia.

    Science.gov (United States)

    Yimer, Mulat; Hailu, Tadesse; Mulu, Wondemagegn; Abera, Bayeh

    2015-12-26

    Although the sensitivity of Wet mount technique is questionable, it is the major diagnostic technique for routine diagnosis of intestinal parasitosis in Ethiopia. Therefore, the aim of this study was the evaluation performance of diagnostic methods of intestinal parasitosis in school age children in Ethiopia. A cross sectional study was conducted from May to June 2013. Single stool sample was processed for direct, Formol ether concentration (FEC) and Kato Katz methods. The sensitivity and negative predictive value (NPV) of diagnostic tests were calculated in terms of the "Gold" standard method (the combined result of the three methods altogether). A total of 422 school age children were participated in this study. The prevalence of intestinal parasites was high (74.6%) with Kato Katz technique. The sensitivity of Wet mount, FEC and Kato Katz tests against the Gold standard test was 48.9, 63.1 and 93.7%, respectively. Kato Katz technique revealed a better NPV 80.4 (80.1-80.6) as compared to the Wet mount (33.7%) and FEC techniques (41.3%). In this study, the Kato Katz technique outperformed the other two methods but the true values for sensitivity, specificity and diagnostic values are not known. Moreover, it is labor intensive and not easily accessible. Hence, it is preferable to use FEC technique to complement the Wet mount test.

  20. Simulated performance of the optical Thomson scattering diagnostic designed for the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Ross, J. S., E-mail: ross36@llnl.gov; Datte, P.; Divol, L.; Galbraith, J.; Hatch, B.; Landen, O.; Manuel, A. M.; Molander, W.; Moody, J. D.; Swadling, G. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States); Froula, D. H.; Katz, J. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States); Glenzer, S. H. [SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Kilkenny, J. [General Atomics, San Diego, California 92186 (United States); Montgomery, D. S. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Weaver, J. [Plasma Physics Division, Naval Research Laboratory, Washington, DC 20375 (United States)

    2016-11-15

    An optical Thomson scattering diagnostic has been designed for the National Ignition Facility to characterize under-dense plasmas. We report on the design of the system and the expected performance for different target configurations. The diagnostic is designed to spatially and temporally resolve the Thomson scattered light from laser driven targets. The diagnostic will collect scattered light from a 50 × 50 × 200 μm volume. The optical design allows operation with different probe laser wavelengths. A deep-UV probe beam (λ{sub 0} = 210 nm) will be used to Thomson scatter from electron plasma densities of ∼5 × 10{sup 20} cm{sup −3} while a 3ω probe will be used for plasma densities of ∼1 × 10{sup 19} cm{sup −3}. The diagnostic package contains two spectrometers: the first to resolve Thomson scattering from ion acoustic wave fluctuations and the second to resolve scattering from electron plasma wave fluctuations. Expected signal levels relative to background will be presented for typical target configurations (hohlraums and a planar foil).

  1. Diagnostic Performance of Mammographic Texture Analysis in the Differential Diagnosis of Benign and Malignant Breast Tumors.

    Science.gov (United States)

    Li, Zhiming; Yu, Lan; Wang, Xin; Yu, Haiyang; Gao, Yuanxiang; Ren, Yande; Wang, Gang; Zhou, Xiaoming

    2017-11-09

    The purpose of this study was to investigate the diagnostic performance of mammographic texture analysis in the differential diagnosis of benign and malignant breast tumors. Digital mammography images were obtained from the Picture Archiving and Communication System at our institute. Texture features of mammographic images were calculated. Mann-Whitney U test was used to identify differences between the benign and malignant group. The receiver operating characteristic (ROC) curve analysis was used to assess the diagnostic performance of texture features. Significant differences of texture features of histogram, gray-level co-occurrence matrix (GLCM) and run length matrix (RLM) were found between the benign and malignant breast group (P  .05). The AUROCs of imaging-based diagnosis, texture analysis, and imaging-based diagnosis combined with texture analysis were 0.873, 0.863, and 0.961, respectively. When imaging-based diagnosis was combined with texture analysis, the AUROC was higher than that of imaging-based diagnosis or texture analysis (P benign and malignant breast tumors. Furthermore, the combination of imaging-based diagnosis and texture analysis can significantly improve diagnostic performance. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. New On-board Microprocessors

    Science.gov (United States)

    Weigand, R.

    Two new processor devices have been developed for the use on board of spacecrafts. An 8-bit 8032-microcontroller targets typical controlling applications in instruments and sub-systems, or could be used as a main processor on small satellites, whereas the LEON 32-bit SPARC processor can be used for high performance controlling and data processing tasks. The ADV80S32 is fully compliant to the Intel 80x1 architecture and instruction set, extended by additional peripherals, 512 bytes on-chip RAM and a bootstrap PROM, which allows downloading the application software using the CCSDS PacketWire pro- tocol. The memory controller provides a de-multiplexed address/data bus, and allows to access up to 16 MB data and 8 MB program RAM. The peripherals have been de- signed for the specific needs of a spacecraft, such as serial interfaces compatible to RS232, PacketWire and TTC-B-01, counters/timers for extended duration and a CRC calculation unit accelerating the CCSDS TM/TC protocol. The 0.5 um Atmel manu- facturing technology (MG2RT) provides latch-up and total dose immunity; SEU fault immunity is implemented by using SEU hardened Flip-Flops and EDAC protection of internal and external memories. The maximum clock frequency of 20 MHz allows a processing power of 3 MIPS. Engineering samples are available. For SW develop- ment, various SW packages for the 8051 architecture are on the market. The LEON processor implements a 32-bit SPARC V8 architecture, including all the multiply and divide instructions, complemented by a floating-point unit (FPU). It includes several standard peripherals, such as timers/watchdog, interrupt controller, UARTs, parallel I/Os and a memory controller, allowing to use 8, 16 and 32 bit PROM, SRAM or memory mapped I/O. With on-chip separate instruction and data caches, almost one instruction per clock cycle can be reached in some applications. A 33-MHz 32-bit PCI master/target interface and a PCI arbiter allow operating the device in a plug-in card

  3. POTENTIALITIES OF DIAGNOSTICS AND DIFFERENTIAL DIAGNOSTICS OF STOMACH DISEASES BY MEANS OF USAGE OF HIGH-PERFORMANCE BLOOD SERUM LIQUID CHROMATOGRAPHY

    Directory of Open Access Journals (Sweden)

    O.P. Alexeeva

    2008-12-01

    Full Text Available 62 patients with the endoscopically and morphologicallyverified diagnosis of the chronic gastritis, 89 patients with the morphologically verified diagnosis of stomach cancer and 43 healthy persons ages 23 to 54 years have been examined. Potentialities of the usage of high-performance blood serum liquid chromatography have been studied for the purpose of diagnostics and differential diagnostics of chronic gastritis and stomach cancer. Blood serum driedextract was investigated by means of"Milichrome A02"chromatograph (Novosibirsk, "Econova" joint-stock company. The chromatograms were treated by the multivahate cluster analysis with the formation of pathologic three-dimensional characteristic state notably differed from the healthy human image. Diagnostic sensitivity of chronic gastritis and stomach cancer acounts for accordingly 92% and 96%. Diagnostic accuracy of the method comes to 94%.

  4. Verification of ICESat-2/ATLAS Science Receiver Algorithm Onboard Databases

    Science.gov (United States)

    Carabajal, C. C.; Saba, J. L.; Leigh, H. W.; Magruder, L. A.; Urban, T. J.; Mcgarry, J.; Schutz, B. E.

    2013-12-01

    NASA's ICESat-2 mission will fly the Advanced Topographic Laser Altimetry System (ATLAS) instrument on a 3-year mission scheduled to launch in 2016. ATLAS is a single-photon detection system transmitting at 532nm with a laser repetition rate of 10 kHz, and a 6 spot pattern on the Earth's surface. A set of onboard Receiver Algorithms will perform signal processing to reduce the data rate and data volume to acceptable levels. These Algorithms distinguish surface echoes from the background noise, limit the daily data volume, and allow the instrument to telemeter only a small vertical region about the signal. For this purpose, three onboard databases are used: a Surface Reference Map (SRM), a Digital Elevation Model (DEM), and a Digital Relief Maps (DRMs). The DEM provides minimum and maximum heights that limit the signal search region of the onboard algorithms, including a margin for errors in the source databases, and onboard geolocation. Since the surface echoes will be correlated while noise will be randomly distributed, the signal location is found by histogramming the received event times and identifying the histogram bins with statistically significant counts. Once the signal location has been established, the onboard Digital Relief Maps (DRMs) will be used to determine the vertical width of the telemetry band about the signal. University of Texas-Center for Space Research (UT-CSR) is developing the ICESat-2 onboard databases, which are currently being tested using preliminary versions and equivalent representations of elevation ranges and relief more recently developed at Goddard Space Flight Center (GSFC). Global and regional elevation models have been assessed in terms of their accuracy using ICESat geodetic control, and have been used to develop equivalent representations of the onboard databases for testing against the UT-CSR databases, with special emphasis on the ice sheet regions. A series of verification checks have been implemented, including

  5. Improving the diagnostic performance of lung scintigraphy in suspected pulmonary embolic disease

    International Nuclear Information System (INIS)

    Gleeson, F.V.; Turner, S.; Scarsbrook, A.F.

    2006-01-01

    Aim: to determine the effectiveness of a new imaging algorithm in the investigation of suspected pulmonary embolism (PE). Materials and methods: A new imaging algorithm for suspected PE was introduced following the installation of a multisection computed tomography (CT) machine at our institution. Before its installation, patients with suspected PE were evaluated with ventilation/perfusion (V/Q) scintigraphy. Subsequently, patients were triaged according to chest radiography (CR) and respiratory history to either lung scintigraphy or CT pulmonary angiography (CTPA). Patients with a normal CR and no history of lung disease were evaluated using perfusion (Q) scintigraphy [ventilation (V) scintigraphy was no longer performed]. Patients with an abnormal CR, asthma or chronic lung disease were evaluated using CTPA. All V/Q images in a continuous 3-year period before the introduction of the new imaging algorithm and all Q images performed in a 3-year period after its introduction were retrospectively reviewed. Imaging reports were categorized into normal, non-diagnostic (low or intermediate probability) or high probability for PE. Patients in the later group who subsequently underwent CTPA, were also reviewed. Results: After the policy change the percentage of normal scintigrams significantly increased (39 to 60%; p < 0.001). There was a non-significant increase in the percentage of high probability scintigrams (15 to 18%; p = 0.716). Overall the diagnostic yield of lung scintigraphy improved significantly (54 to 78%; p < 0.001). Conclusion: the diagnostic performance of lung scintigraphy can be improved by careful triage of patients to either Q scintigraphy or CTPA based on clinical history and CR findings. Q scintigraphy remains a valuable diagnostic test in the investigation of suspected PE in carefully selected patients

  6. Chest radiography with a shaped filter has no diagnostic advantage: Demonstration by observer performance tests

    International Nuclear Information System (INIS)

    Guilbeau, J.C.; Mazoyer, B.; Pruvost, P.; Verrey, B.; Grenier, P.

    1987-01-01

    The effectiveness of a shaped filter in improving the detection of mediastinal and retrocardiac abnormalities on 140-kV posteroanterior chest radiographs was measured by observer performance testing. The filtered and unfiltered radiographs of 50 patients were randomly selected from 1,000 radiographs obtained from 500 ambulatory or hospitalized patients and were independently read by five observers. Observer performance in detecting abnormalities in the central area was analyzed by receiver operating characteristic (ROC) techniques. The results indicate that the use of a filter has no significant diagnostic advantage, regardless of type or location of lesions over the mediastinum and the retrocardiac areas

  7. The Effects of Fatigue From Overnight Shifts on Radiology Search Patterns and Diagnostic Performance.

    Science.gov (United States)

    Hanna, Tarek N; Zygmont, Matthew E; Peterson, Ryan; Theriot, David; Shekhani, Haris; Johnson, Jamlik-Omari; Krupinski, Elizabeth A

    2018-01-20

    The aim of this study was to assess the effect of overnight shifts (ONS) on radiologist fatigue, visual search pattern, and diagnostic performance. This experimental study was approved by the institutional review board. Twelve radiologists (five faculty members and seven residents) each completed two sessions: one during a normal workday ("not fatigued") and another in the morning after an ONS ("fatigued"). Each radiologist completed the Swedish Occupational Fatigue Inventory. During each session, radiologists viewed 20 bone radiographs consisting of normal and abnormal findings. Viewing time, diagnostic confidence, and eye-tracking data were recorded. Swedish Occupational Fatigue Inventory results demonstrated worsening in all five variables (lack of energy, physical exertion, physical discomfort, lack of motivation, and sleepiness) after ONS (P radiologists were more fatigued with worse diagnostic performance, a 45% increase in view time per case, a 60% increase in total gaze fixations, and a 34% increase in time to fixate on the fracture. The effects of fatigue were more pronounced in residents. Copyright © 2017 American College of Radiology. Published by Elsevier Inc. All rights reserved.

  8. Diagnostic performance of computed tomography for parathyroid adenoma localization; a systematic review and meta-analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kluijfhout, Wouter P., E-mail: WPKluijfhout@gmail.com [Department of Surgery, University of California San Francisco (United States); Department of Surgery, University Medical Center Utrecht (Netherlands); Pasternak, Jesse D. [Department of Surgery, University Health Network Toronto (Canada); Beninato, Toni; Drake, Frederick Thurston; Gosnell, Jessica E.; Shen, Wen T.; Duh, Quan-Yang [Department of Surgery, University of California San Francisco (United States); Allen, Isabel E. [Department of Epidemiology and Biostatistics, University of California San Francisco (United States); Vriens, Menno R. [Department of Surgery, University Medical Center Utrecht (Netherlands); Keizer, Bart de [Department of Radiology, University Medical Center Utrecht (Netherlands); Hope, Thomas A. [Department of Radiology, University of California San Francisco (United States); Suh, Insoo [Department of Surgery, University of California San Francisco (United States)

    2017-03-15

    Highlights: • CT performs well in localizing pathological parathyroid glands. • Performance of CT is less in patients with inconclusive ultrasound and sestamibi. • Addition of a third contrast phase seems to have little added value. - Abstract: Abstract purpose: To perform a systematic review and meta-analysis of the sensitivity and positive predictive value (PPV) of CT for preoperative parathyroid localization in patients with primary hyperparathyroidism (pHPT), and subsequently compare the different protocols and their performance in different patient groups. Materials and methods: We performed a search of the Embase, Pubmed and Cochrane Library databases to identify studies published between January 1, 2000 and March 31, 2016 investigating the diagnostic value of CT for parathyroid localization in patients with biochemical diagnosis of pHPT. Performance of CT was expressed in sensitivity and PPV with pooled proportion using a random-effects model. Factors that could have affected the diagnostic performance were investigated by subgroup analysis. Results: Thirty-four studies evaluating a total of 2563 patients with non-familial pHPT who underwent CT localization and surgical resection were included. Overall pooled sensitivity of CT for localization of the pathological parathyroid(s) to the correct quadrant was 73% (95% CI: 69–78%), which increased to 81% (95% CI: 75–87%) for lateralization to the correct side. Subgroup analysis based on the number of contrast phases showed that adding a second contrast phase raises sensitivity from 71% (95% CI: 61–80%) to 76% (95% CI: 71–87%), and that adding a third phase resulted in a more modest additional increase in performance with a sensitivity of 80% (95% CI: 74–86%). Conclusion: CT performs well in localizing pathological glands in patients with pHPT. A protocol with two contrast phases seems to offer a good balance of acceptable performance with limitation of radiation exposure.

  9. A simple, high performance Thomson scattering diagnostic for high temperature plasma research

    International Nuclear Information System (INIS)

    Hartog, D.J.D.; Cekic, M.

    1994-02-01

    This Thomson scattering diagnostic is used to measure the electron temperature and density of the plasma in the MST reversed-field pinch, a magnetic confinement fusion research device. This diagnostic system is unique for its type in that it combines high performance with simple design and low cost components. In the design of this instrument, careful attention was given to the suppression of stray laser line light with simple and effective beam dumps, viewing dumps, aperatures, and a holographic edge filter. This allows the use of a single grating monochromator for dispersion of the Thomson scattered spectrum onto the microchannel plate detector. Alignment and calibration procedures for the laser beam delivery system, the scattered light collection system, and the spectrometer and detector are described. A sample Thomson scattered spectrum illustrates typical data

  10. Diagnostic performance of cytology for assessment of hepatic lipid content in dairy cattle.

    Science.gov (United States)

    Fry, M M; Yao, B; Ríos, C; Wong, C; Mann, S; McArt, J A A; Nydam, D V; Leal Yepes, F A; Viesselmann, L; Geick, A; Goldin, K; Jordan, A; Behling-Kelly, E

    2018-02-01

    The objective of our study was to characterize the diagnostic performance of cytology for assessing hepatic lipid content (HLC) in dairy cows by comparing microscopic evaluation of lipid vacuolation in touch imprint slide preparations of liver biopsies with quantitative measurement of triglyceride concentration ([TG]; mg/mg of wet weight) in paired biopsy samples. Our study also sought to compare the diagnostic performance of liver cytology, plasma nonesterified fatty acid concentration ([NEFA]), and plasma β-hydroxybutyrate concentration ([BHB]) derived from a measurement performed on whole blood, for assessing HLC. Chemical extraction of TG from liver tissue remains the gold standard for quantifying HLC, largely because available blood tests, although useful for detecting some types of pathology, such as increased lipid mobilization, ketosis, or hepatocellular injury, are nonspecific as to etiology. Veterinary practitioners can sample bovine liver for cytological evaluation in a fast, minimally invasive, and inexpensive manner. Thus, if highly predictive of HLC, cytology would be a practical diagnostic tool for dairy veterinarians. In our study, liver biopsy samples from Holstein cows (219 samples from 105 cows: 52 from cows 2 to 20 d prepartum, 105 from cows 0 to 10 d in milk, 62 from cows 18 to 25 d in milk) were used to prepare cytology slides and to quantify [TG] using the Folch extraction method followed by the Hantzch condensation reaction and spectrophotometric measurement. An ordinal scale (0-4) based on amount of hepatocellular cytoplasm occupied by discrete clear vacuoles was used by 3 blinded, independent observers to rank HLC in Wright-Giemsa-stained slides. Interobserver agreement in cytology scoring was good. Corresponding plasma [NEFA] and [BHB] measurements were available for 187 and 195 of the 219 samples, respectively. Liver [TG] correlated more strongly with cytology score than with NEFA or BHB, and receiver operating characteristic curve

  11. Diagnostic performances of serum liver enzymes and cytokines in non-alcoholic fatty liver disease

    Directory of Open Access Journals (Sweden)

    Hakan Turkon

    2015-03-01

    Full Text Available Objective:Non-alcoholic fatty liver disease (NAFLD is affecting people worldwide with increasing prevalence. Non-invasive tests are required for both diagnosis and staging of the disease. We aimed to evaluate diagnostic accuracy of routine liver enzymes and cytokines in NAFLD. Methods:A total of 88 cases, aged between 20 and 62 years, were included in the study. Serum ALT, AST, GGT, triglyceride, TNF-alpha, IL-6 and IL-8 were measured in 40 patients with NAFLD and in 48 healthy control patients with similar BMI and demographic characteristics. Diagnostic performances of serum biomarkers for diagnosis of NAFLD were evaluated with ROC analysis. Results:ALT and AST showed good diagnostic performance in predicting patients with NAFLD in the overall group (AUC=0.817; 95% CI[0.721-0.913], AUC=0.815;95% CI[0.718-0.911] respectively but in obese subjects ALT and AST showed poor performance (AUC=0.659;95% CI[0.478-0.841], AUC=0.680; 95% CI[0.498-0.861] respectively. Among cytokines TNF-alpha showed best performance in the diagnosis of NAFLD in both overall group and obese subjects (AUC=0.892; 95% CI[0.824- 0.959], AUC=0.858; 95% CI[0.739-0.977] respectively. The optimal cut off value for TNF-alpha was 10.65pg/ml with a sensitivity of 75% and a specificity of 93% in the overall group. IL-6 and IL-8 showed poor performance. Conclusion: TNF-alpha may be a good parameter for predicting patients with NAFLD. J Clin Exp Invest 2015;6 (1: 16-20

  12. Optimization of Classification Strategies of Acetowhite Temporal Patterns towards Improving Diagnostic Performance of Colposcopy

    Directory of Open Access Journals (Sweden)

    Karina Gutiérrez-Fragoso

    2017-01-01

    Full Text Available Efforts have been being made to improve the diagnostic performance of colposcopy, trying to help better diagnose cervical cancer, particularly in developing countries. However, improvements in a number of areas are still necessary, such as the time it takes to process the full digital image of the cervix, the performance of the computing systems used to identify different kinds of tissues, and biopsy sampling. In this paper, we explore three different, well-known automatic classification methods (k-Nearest Neighbors, Naïve Bayes, and C4.5, in addition to different data models that take full advantage of this information and improve the diagnostic performance of colposcopy based on acetowhite temporal patterns. Based on the ROC and PRC area scores, the k-Nearest Neighbors and discrete PLA representation performed better than other methods. The values of sensitivity, specificity, and accuracy reached using this method were 60% (95% CI 50–70, 79% (95% CI 71–86, and 70% (95% CI 60–80, respectively. The acetowhitening phenomenon is not exclusive to high-grade lesions, and we have found acetowhite temporal patterns of epithelial changes that are not precancerous lesions but that are similar to positive ones. These findings need to be considered when developing more robust computing systems in the future.

  13. Comparative diagnostic performance of multidetector computed tomography and MRI for characterization of pancreatic cystic lesions

    International Nuclear Information System (INIS)

    Moon, Sung Min; Shin, Sang Soo; Park, Jin Gyoon; Jeong, Yong Yeon

    2015-01-01

    To compare the diagnostic performance of multidetector computed tomography (MDCT) and magnetic resonance imaging (MRI) in characterization of pancreatic cystic lesions. We conducted a retrospective study on 34 patients with histopathologically proven cystic pancreatic lesions who underwent both preoperative MDCT and MRI. CT and MRI were independently evaluated for differentiating mucinous vs. non-mucinous lesions, differentiating aggressive vs. non-aggressive lesion, analyzing morphological features, and evaluating specific leading diagnoses. Sensitivity, specificity, and accuracy were determined. Competency assessment of lesional morphology analysis was performed using the kappa values of the 2 tests. The sensitivity, specificity, and accuracy of MRI for differentiating mucinous vs. non-mucinous lesions were higher than CT (p = 0.03). For differentiating aggressiveness, the sensitivity of MRI was better than CT, but the specificity of CT was better than MRI. In evaluation of morphologic features, MRI showed better performance in characterization of septa and wall. Otherwise, the 2 modalities showed similarly good performance. MRI was better than CT in determining a specific diagnosis (58.8% vs. 47.2%, respectively). CT and MRI are reasonable diagnostic methods for characterization of pancreatic cystic lesions. However, MRI enables more confident assessment than CT in differentiating mucinous vs. non-mucinous lesions and characterization of the septa and wall

  14. Ruling out pulmonary embolism in primary care : Comparison of the diagnostic performance of “gestalt” and the wells rule

    NARCIS (Netherlands)

    Hendriksen, Janneke M T; Lucassen, Wim A M; Erkens, Petra M G; Stoffers, Henri E J H; van Weert, Henk C P M; Büller, Harry R.; Hoes, Arno W.; Moons, Karel G M; Geersing, Geert Jan

    2016-01-01

    PURPOSE Diagnostic prediction models such as the Wells rule can be used for safely ruling out pulmonary embolism (PE) when it is suspected. A physician’s own probability estimate (“gestalt”), however, is commonly used instead. We evaluated the diagnostic performance of both approaches in primary

  15. Ruling Out Pulmonary Embolism in Primary Care: Comparison of the Diagnostic Performance of "Gestalt" and the Wells Rule

    NARCIS (Netherlands)

    Hendriksen, Janneke M. T.; Lucassen, Wim A. M.; Erkens, Petra M. G.; Stoffers, Henri E. J. H.; van Weert, Henk C. P. M.; Büller, Harry R.; Hoes, Arno W.; Moons, Karel G. M.; Geersing, Geert-Jan

    2016-01-01

    Diagnostic prediction models such as the Wells rule can be used for safely ruling out pulmonary embolism (PE) when it is suspected. A physician's own probability estimate ("gestalt"), however, is commonly used instead. We evaluated the diagnostic performance of both approaches in primary care.

  16. 9 CFR 130.15 - User fees for veterinary diagnostic isolation and identification tests performed at NVSL...

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false User fees for veterinary diagnostic isolation and identification tests performed at NVSL (excluding FADDL) or other authorized site. 130.15... AGRICULTURE USER FEES USER FEES § 130.15 User fees for veterinary diagnostic isolation and identification...

  17. Diagnostic performance of serological tests to detect antibodies against acute scrub typhus infection in central India

    Directory of Open Access Journals (Sweden)

    Kiran Pote

    2018-01-01

    Full Text Available Background: Differentiating scrub typhus from other acute febrile illness is difficult due to non specificity of clinical symptoms and relative absence of eschar in Indian population. The diagnosis thus relies mainly on laboratory tests. Antibody based serological tests are mainstay of scrub typhus diagnosis. Here, we evaluated the diagnostic performance of IgM ELISA, IgM IFA and ICT to detect antibodies against O. tsutsugamushi in acute serum of febrile patients. Methodology: The serum samples from 600 randomly selected patients suffering from acute undifferentiated fever were tested by all the three tests mentioned above. We used latent class analysis to generate unbiased results as all the tests for scrub typhus diagnosis are imperfect and none of them can be considered as reference standard. Results: We found that IgM ELISA with cutoff titer 0.5 OD has high diagnostic accuracy (sensitivity 99.9% and specificity 99.15 than IgM IFA (sensitivity 96.8% and specificity 99.7% for scrub typhus diagnosis. ICT used in our study had very high specificity 100% but low sensitivity (38% which would limit its use for acute serum samples. ICT being a screening or point of care test, has to be more sensitive while some compromise with specificity is affordable. Hence, optimal cutoff for ICT should be evaluated under different settings. Conclusion: IgM ELISA being simple and affordable could be an alternative diagnostic test to IgM IFA which is subjective and costly.

  18. Diagnostic performance of serological tests to detect antibodies against acute scrub typhus infection in central India.

    Science.gov (United States)

    Pote, Kiran; Narang, Rahul; Deshmukh, Pradeep

    2018-01-01

    Differentiating scrub typhus from other acute febrile illness is difficult due to non specificity of clinical symptoms and relative absence of eschar in Indian population. The diagnosis thus relies mainly on laboratory tests. Antibody based serological tests are mainstay of scrub typhus diagnosis. Here, we evaluated the diagnostic performance of IgM ELISA, IgM IFA and ICT to detect antibodies against O. tsutsugamushi in acute serum of febrile patients. The serum samples from 600 randomly selected patients suffering from acute undifferentiated fever were tested by all the three tests mentioned above. We used latent class analysis to generate unbiased results as all the tests for scrub typhus diagnosis are imperfect and none of them can be considered as reference standard. We found that IgM ELISA with cutoff titer 0.5 OD has high diagnostic accuracy (sensitivity 99.9% and specificity 99.15) than IgM IFA (sensitivity 96.8% and specificity 99.7%) for scrub typhus diagnosis. ICT used in our study had very high specificity 100% but low sensitivity (38%) which would limit its use for acute serum samples. ICT being a screening or point of care test, has to be more sensitive while some compromise with specificity is affordable. Hence, optimal cutoff for ICT should be evaluated under different settings. IgM ELISA being simple and affordable could be an alternative diagnostic test to IgM IFA which is subjective and costly.

  19. Diagnostic performance of BMI percentiles to identify adolescents with metabolic syndrome.

    Science.gov (United States)

    Laurson, Kelly R; Welk, Gregory J; Eisenmann, Joey C

    2014-02-01

    To compare the diagnostic performance of the Centers for Disease Control and Prevention (CDC) and FITNESSGRAM (FGram) BMI standards for quantifying metabolic risk in youth. Adolescents in the NHANES (n = 3385) were measured for anthropometric variables and metabolic risk factors. BMI percentiles were calculated, and youth were categorized by weight status (using CDC and FGram thresholds). Participants were also categorized by presence or absence of metabolic syndrome. The CDC and FGram standards were compared by prevalence of metabolic abnormalities, various diagnostic criteria, and odds of metabolic syndrome. Receiver operating characteristic curves were also created to identify optimal BMI percentiles to detect metabolic syndrome. The prevalence of metabolic syndrome in obese youth was 19% to 35%, compared with <2% in the normal-weight groups. The odds of metabolic syndrome for obese boys and girls were 46 to 67 and 19 to 22 times greater, respectively, than for normal-weight youth. The receiver operating characteristic analyses identified optimal thresholds similar to the CDC standards for boys and the FGram standards for girls. Overall, BMI thresholds were more strongly associated with metabolic syndrome in boys than in girls. Both the CDC and FGram standards are predictive of metabolic syndrome. The diagnostic utility of the CDC thresholds outperformed the FGram values for boys, whereas FGram standards were slightly better thresholds for girls. The use of a common set of thresholds for school and clinical applications would provide advantages for public health and clinical research and practice.

  20. MR arthrography in calcific tendinitis of the shoulder: diagnostic performance and pitfalls

    Energy Technology Data Exchange (ETDEWEB)

    Zubler, Christoph; Mengiardi, Bernard; Schmid, Marius R.; Hodler, Juerg; Pfirrmann, Christian W.A. [University Hospital Balgrist, Radiology, Zurich (Switzerland); Jost, Bernhard [University Hospital Balgrist, Orthopedic Surgery, Zurich (Switzerland)

    2007-06-15

    The purpose was to assess the diagnostic performance of MR arthrography to diagnose calcific tendinitis of the shoulder and to assess the reasons for diagnostic errors. Standard MR arthrograms of 22 patients with calcific tendinitis and 61 controls were retrospectively analyzed by two independent and blinded radiologists. All cases were consecutively collected from a database. Conventional radiographs were available in all cases serving as gold standard. The supraspinatus was involved in 16, the infraspinatus in four and the subscapularis in two patients. All diagnostic errors were analyzed by two additional readers. Reader 1 correctly detected 12 of the 22 shoulders with and 42 of the 61 shoulders without calcific tendinitis (sensitivity 0.55, specificity 0.66). The corresponding values for reader 2 were 13 of 22 and 40 of 61 cases (sensitivity 0.59, specificity 0.69). Inter-rater agreement (kappa-value) was 0.42. Small size of the calcific deposits and isointensity compared to the surrounding tissue were the most important reasons for false negative results. Normal hypointense areas within the supraspinatus tendon substance and attachment were the main reason for false positive results. In conclusion, MR arthrography is insufficient in the diagnosis of calcific tendinitis. Normal hypointense parts of the rotator cuff may mimic calcific deposits and calcifications may not be detected when they are isointense compared to the rotator cuff. Therefore, MR imaging should not be interpreted without corresponding radiographs. (orig.)

  1. Overview of diagnostic performance and results for the first operation phase in Wendelstein 7-X (invited).

    Science.gov (United States)

    Krychowiak, M; Adnan, A; Alonso, A; Andreeva, T; Baldzuhn, J; Barbui, T; Beurskens, M; Biel, W; Biedermann, C; Blackwell, B D; Bosch, H S; Bozhenkov, S; Brakel, R; Bräuer, T; Brotas de Carvalho, B; Burhenn, R; Buttenschön, B; Cappa, A; Cseh, G; Czarnecka, A; Dinklage, A; Drews, P; Dzikowicka, A; Effenberg, F; Endler, M; Erckmann, V; Estrada, T; Ford, O; Fornal, T; Frerichs, H; Fuchert, G; Geiger, J; Grulke, O; Harris, J H; Hartfuß, H J; Hartmann, D; Hathiramani, D; Hirsch, M; Höfel, U; Jabłoński, S; Jakubowski, M W; Kaczmarczyk, J; Klinger, T; Klose, S; Knauer, J; Kocsis, G; König, R; Kornejew, P; Krämer-Flecken, A; Krawczyk, N; Kremeyer, T; Książek, I; Kubkowska, M; Langenberg, A; Laqua, H P; Laux, M; Lazerson, S; Liang, Y; Liu, S C; Lorenz, A; Marchuk, A O; Marsen, S; Moncada, V; Naujoks, D; Neilson, H; Neubauer, O; Neuner, U; Niemann, H; Oosterbeek, J W; Otte, M; Pablant, N; Pasch, E; Sunn Pedersen, T; Pisano, F; Rahbarnia, K; Ryć, L; Schmitz, O; Schmuck, S; Schneider, W; Schröder, T; Schuhmacher, H; Schweer, B; Standley, B; Stange, T; Stephey, L; Svensson, J; Szabolics, T; Szepesi, T; Thomsen, H; Travere, J-M; Trimino Mora, H; Tsuchiya, H; Weir, G M; Wenzel, U; Werner, A; Wiegel, B; Windisch, T; Wolf, R; Wurden, G A; Zhang, D; Zimbal, A; Zoletnik, S

    2016-11-01

    Wendelstein 7-X, a superconducting optimized stellarator built in Greifswald/Germany, started its first plasmas with the last closed flux surface (LCFS) defined by 5 uncooled graphite limiters in December 2015. At the end of the 10 weeks long experimental campaign (OP1.1) more than 20 independent diagnostic systems were in operation, allowing detailed studies of many interesting plasma phenomena. For example, fast neutral gas manometers supported by video cameras (including one fast-frame camera with frame rates of tens of kHz) as well as visible cameras with different interference filters, with field of views covering all ten half-modules of the stellarator, discovered a MARFE-like radiation zone on the inboard side of machine module 4. This structure is presumably triggered by an inadvertent plasma-wall interaction in module 4 resulting in a high impurity influx that terminates some discharges by radiation cooling. The main plasma parameters achieved in OP1.1 exceeded predicted values in discharges of a length reaching 6 s. Although OP1.1 is characterized by short pulses, many of the diagnostics are already designed for quasi-steady state operation of 30 min discharges heated at 10 MW of ECRH. An overview of diagnostic performance for OP1.1 is given, including some highlights from the physics campaigns.

  2. MR arthrography in calcific tendinitis of the shoulder: diagnostic performance and pitfalls

    International Nuclear Information System (INIS)

    Zubler, Christoph; Mengiardi, Bernard; Schmid, Marius R.; Hodler, Juerg; Pfirrmann, Christian W.A.; Jost, Bernhard

    2007-01-01

    The purpose was to assess the diagnostic performance of MR arthrography to diagnose calcific tendinitis of the shoulder and to assess the reasons for diagnostic errors. Standard MR arthrograms of 22 patients with calcific tendinitis and 61 controls were retrospectively analyzed by two independent and blinded radiologists. All cases were consecutively collected from a database. Conventional radiographs were available in all cases serving as gold standard. The supraspinatus was involved in 16, the infraspinatus in four and the subscapularis in two patients. All diagnostic errors were analyzed by two additional readers. Reader 1 correctly detected 12 of the 22 shoulders with and 42 of the 61 shoulders without calcific tendinitis (sensitivity 0.55, specificity 0.66). The corresponding values for reader 2 were 13 of 22 and 40 of 61 cases (sensitivity 0.59, specificity 0.69). Inter-rater agreement (kappa-value) was 0.42. Small size of the calcific deposits and isointensity compared to the surrounding tissue were the most important reasons for false negative results. Normal hypointense areas within the supraspinatus tendon substance and attachment were the main reason for false positive results. In conclusion, MR arthrography is insufficient in the diagnosis of calcific tendinitis. Normal hypointense parts of the rotator cuff may mimic calcific deposits and calcifications may not be detected when they are isointense compared to the rotator cuff. Therefore, MR imaging should not be interpreted without corresponding radiographs. (orig.)

  3. Glaucoma diagnostic performance of GDxVCC and spectralis OCT on eyes with atypical retardation pattern.

    Science.gov (United States)

    Hoesl, Laura Maria; Tornow, Ralf P; Schrems, Wolfgang A; Horn, Folkert K; Mardin, Christian Y; Kruse, Friedrich E; Juenemann, Anselm G M; Laemmer, Robert

    2013-01-01

    To investigate the impact of typical scan score (TSS) on discriminating glaucomatous and healthy eyes by scanning laser polarimetry and spectral domain optical coherence tomography (SD-OCT) in 32 peripapillary sectors. One hundred two glaucoma patients and 32 healthy controls underwent standard automated perimetry, 24-hour intraocular pressure profile, optic disc photography, GDxVCC, and SD-OCT measurements. For controls, only very typical scans (TSS=100) were accepted. Glaucoma patients were divided into 3 subgroups (very typical: TSS=100; typical: 99≥TSS≥80, atypical: TSS<80). Receiver operating characteristic curves were constructed for mean retinal nerve fiber layer values, sector data, and nerve fiber indicator (NFI). Sensitivity was estimated at ≥90% specificity to compare the discriminating ability of each imaging modality. For discrimination between healthy and glaucomatous eyes with very typical scans, the NFI and inferior sector analyses 26 to 27 demonstrated the highest sensitivity at ≥90% specificity in GDxVCC and SD-OCT, respectively. For the typical and atypical groups, sensitivity at ≥90% specificity decreased for all 32 peripapillary sectors on an average by 10.9% and 17.9% for GDxVCC and by 4.9% and 0.8% for SD-OCT. For GDxVCC, diagnostic performance of peripapillary sectors decreased with lower TSS, especially in temporosuperior and inferotemporal sectors (sensitivity at ≥90% specificity decreased by 55.3% and by 37.8% in the atypical group). Diagnostic accuracy is comparable for SD-OCT and GDxVCC if typical scans (TSS=100) are investigated. Decreasing TSS is associated with a decrease in diagnostic accuracy for discriminating healthy and glaucomatous eyes by scanning laser polarimetry. NFI is less influenced than the global or sector retinal nerve fiber layer thickness. The TSS score should be included in the standard printout. Diagnostic accuracy of SD-OCT is barely influenced by low TSS.

  4. Diagnostic Performance of Ultrasonography for Pediatric Appendicitis: A Night and Day Difference?

    Science.gov (United States)

    Mangona, Kate Louise M; Guillerman, R Paul; Mangona, Victor S; Carpenter, Jennifer; Zhang, Wei; Lopez, Monica; Orth, Robert C

    2017-12-01

    For imaging pediatric appendicitis, ultrasonography (US) is preferred because of its lack of ionizing radiation, but is limited by operator dependence. This study investigates the US diagnostic performance during night shifts covered by radiology trainees compared to day shifts covered by attending radiologists. Appy-Scores (1 = completely visualized normal appendix; 2 = partially visualized normal appendix; 3 = nonvisualized appendix with no inflammatory changes in the expected region of the appendix; 4 = equivocal; 5a = nonperforated appendicitis; 5b = perforated appendicitis) from 2935 US examinations (2161:774, day-to-night) from July 2013 to 2014 were correlated with the intraoperative diagnoses and the clinical follow-up. The diagnostic performance of trainees and attendings was compared with Fisher exact test. Interobserver agreement was measured by Cohen kappa coefficient. Appendicitis prevalence was 25.3% (day) and 22.5% (night). Sensitivity, specificity, accuracy, negative predictive value, and positive predictive vale were 94.0%, 93.7%, 93.8%, 97.9%, and 83.4% during the day and 92.0%, 91.2%, 91.3%, 97.5%, and 75.2% at night. Specificity (P = .048) and positive predictive value (P = .011) differed, with more false positives at night (7%) than during the day (4.7%). Trainee and attending agreement was high (k = 0.995), with Appy-Scores of 1, 4, and 5a most frequently discordant. US has a high diagnostic performance and interobserver agreement for pediatric appendicitis when interpreted by radiology trainees during night shifts or attending radiologists during day shifts. However, lower specificity and positive predictive value at night warrants a thorough trainee education to avoid false-positive examinations. Published by Elsevier Inc.

  5. A Performance Evaluation of Diagnostic X-ray Unit Depends on the Hospitals Size

    International Nuclear Information System (INIS)

    Park, Ju Hun; Im, In Chul; Dong, Kyung Rae; Kang, Se Sik

    2009-01-01

    The purpose of this study is to measure the tube voltage, the tube current/volume, exposure time and exposure dose of diagnostic X-ray unit in each doctor offices, hospitals and general hospitals for evaluating the performance of such device, to learn the method and technology of its measurement and to suggest its importance. Research subjects were total 30 X-ray units and divided into groups of 10 X-ray units each. The tube voltage, the tube current/volume, exposure time and exposure dose were measured using percentage average error, and then reproducibility of exposure dose was measured through calculating coefficient of variation. The results are like followings; The tube voltage correctness examination showed that incongruent devices among total 30 X-ray units were 5 devices (16.7%). The tube current correctness examination showed that incongruent X-ray units were 3 devices (10.0%). The tube current volume correctness examination showed that incongruent X-ray units were 4 devices (13.3%). Finally, according to exposure time correctness examination, incongruent X-ray units were 5 devices (16.7%) and according to reproducibility examination of exposure dose, incongruent X-ray units were 7 devices (23.3%). Above results showed serious problem in performance management based on management regulation of diagnostic X-ray unit; it means that regular checkout and safety management are required, and as doing so, patients will be able to receive good quality of medical service by the reduction of radiation exposure time, image quality administration, unnecessary retake and etc. Therefore, this study suggests that the performance of diagnostic X-ray units should be checked regularly

  6. A Performance Evaluation of Diagnostic X-ray Unit Depends on the Hospitals Size

    Energy Technology Data Exchange (ETDEWEB)

    Park, Ju Hun [Kaya University, Gimhae (Korea, Republic of); Im, In Chul [Gwangju Health College University, Gwangju (Korea, Republic of); Dong, Kyung Rae [Chosun University, Gwangju (Korea, Republic of); Kang, Se Sik [College of Health Science, Catholic University of Pusan, Busan (Korea, Republic of)

    2009-03-15

    The purpose of this study is to measure the tube voltage, the tube current/volume, exposure time and exposure dose of diagnostic X-ray unit in each doctor offices, hospitals and general hospitals for evaluating the performance of such device, to learn the method and technology of its measurement and to suggest its importance. Research subjects were total 30 X-ray units and divided into groups of 10 X-ray units each. The tube voltage, the tube current/volume, exposure time and exposure dose were measured using percentage average error, and then reproducibility of exposure dose was measured through calculating coefficient of variation. The results are like followings; The tube voltage correctness examination showed that incongruent devices among total 30 X-ray units were 5 devices (16.7%). The tube current correctness examination showed that incongruent X-ray units were 3 devices (10.0%). The tube current volume correctness examination showed that incongruent X-ray units were 4 devices (13.3%). Finally, according to exposure time correctness examination, incongruent X-ray units were 5 devices (16.7%) and according to reproducibility examination of exposure dose, incongruent X-ray units were 7 devices (23.3%). Above results showed serious problem in performance management based on management regulation of diagnostic X-ray unit; it means that regular checkout and safety management are required, and as doing so, patients will be able to receive good quality of medical service by the reduction of radiation exposure time, image quality administration, unnecessary retake and etc. Therefore, this study suggests that the performance of diagnostic X-ray units should be checked regularly

  7. Diagnostic performance of dark-blood T2-weighted CMR for evaluation of acute myocardial injury.

    Science.gov (United States)

    Srichai, Monvadi B; Lim, Ruth P; Lath, Narayan; Babb, James; Axel, Leon; Kim, Daniel

    2013-01-01

    We compared the image quality and diagnostic performance of 2 fat-suppression methods for black-blood T2-weighted fast spin-echo (FSE), which are as follows: (a) short T1 inversion recovery (STIR; FSE-STIR) and (b) spectral adiabatic inversion recovery (SPAIR; FSE-SPAIR), for detection of acute myocardial injury. Edema-sensitive T2-weighted FSE cardiac magnetic resonance (CMR) imaging is useful in detecting acute myocardial injury but may experience reduced myocardial signal and signal dropout. The SPAIR pulse aims to eliminate artifacts associated with the STIR pulse. A total of 65 consecutive patients referred for CMR evaluation of myocardial structure and function underwent FSE-STIR and FSE-SPAIR, in addition to cine and late gadolinium enhancement (LGE) CMR. T2-weighted FSE images were independently evaluated by 2 readers for image quality and artifacts (Likert scale of 1-5; best-worst) and presence of increased myocardial signal suggestive of edema. In addition, clinical CMR interpretation, incorporating all CMR sequences available, was recorded for comparison. Diagnostic performance of each T2-weighted sequence was measured using recent (T2, and wall motion. There was a statistically significant difference in sensitivity between the clinical interpretation and each of the T2-weighted sequences but not between each T2-weighted sequence. Although FSE-SPAIR demonstrated significantly improved image quality and decreased artifacts, isolated interpretations of each T2-weighted technique demonstrated high specificity but overall low sensitivity for the detection of myocardial injury, with no difference in accuracy between the techniques. However, real-world interpretation in combination with cine and LGE CMR methods significantly improves the overall sensitivity and diagnostic performance.

  8. General guidelines about performance specifications for purchasing equipment for x-ray diagnostics, with comments

    International Nuclear Information System (INIS)

    1995-12-01

    These general guidelines are intended to be used as a basis for what requirements are reasonable from a radiation protection point of view and should be part of the contract in connection with the purchase of equipment for x-ray diagnostics. Technical performance requirements are addressed as well as items like documentation, instructions for use and education and training. The guidelines are also useful for the design of quality assurance programs. In the comments in addition to these guidelines legal aspects are noted, including a list of relevant laws, regulations and directives. Standards, both national and international, within the field are referred to with a short description of their content. 40 refs

  9. Measurement of the performance characteristics of diagnostic X-ray systems used in medicine

    International Nuclear Information System (INIS)

    1981-01-01

    A booklet has been produced by the Diagnostic Radiology Topic Group of the Hospital Physicists' Association, providing the basis for exhaustive performance tests on X-ray image intensifier television systems. After a general introduction to the equipment, the parameters which may need to be assessed are outlined in section 1. The measurement techniques and equipment necessary to undertake the measurements are presented in section 2. Specimen data sheets are also presented which the user may find useful to record the data acquired in the field. (U.K.)

  10. General guidelines about performance specifications for purchasing equipment for x-ray diagnostics, with comments

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-01

    These general guidelines are intended to be used as a basis for what requirements are reasonable from a radiation protection point of view and should be part of the contract in connection with the purchase of equipment for x-ray diagnostics. Technical performance requirements are addressed as well as items like documentation, instructions for use and education and training. The guidelines are also useful for the design of quality assurance programs. In the comments in addition to these guidelines legal aspects are noted, including a list of relevant laws, regulations and directives. Standards, both national and international, within the field are referred to with a short description of their content. 40 refs.

  11. Diagnostic performance of sonoelastographic Tsukuba score and strain ratio in evaluation of breast masses

    Directory of Open Access Journals (Sweden)

    Mahmoud Abd Elaziz Dawood

    2018-03-01

    Full Text Available The aim of this prospective study was to evaluate the diagnostic performance of the use of strain index ratio by sonoelastography to differentiate between benign and malignant breast lesions. Patients & Methods: This prospective study including 40 females, complaining of breast masses which were suspicious to be malignant on clinical examination. All patients were submitted to B-mode Ultrasound and sonoelastography. Biopsy as a gold standard and pathological study were done for all breast lesions. Results: US examination of every mass was done and categorized according to BI-RADS categories according to ACR2013, according to US lexicon. Sonoelastography examination with Lesions classification was performed on the basis of a 5-point scoring method proposed by Tsukuba elasticity score. Then measurements of strain ratio were done. Statistical analysis of combination of the three methods was sensitivity of 96.7%, specificity of 100% when we use cut off value of 3–4 in elastography score and ≤3 cut off value of strain ratio. Conclusion: The combined use of strain ratio with Tsukuba score and BI-RADS categorization increased the diagnostic performance in differentiation between benign and malignant breast lesions. Keywords: Elastography, Breast masses, Strain ratio, Ultrasound, BI-RADS classification, Tsukuba score

  12. Diagnostic performance of dual-staining cytology for cervical cancer screening: A systematic literature review.

    Science.gov (United States)

    Tjalma, Wiebren A A

    2017-03-01

    Cervical cancer screening saves lives. Secondary prevention in cervical cancer screening relies on the results of primary cytology and/or HPV testing. However, primary screening with cytology has a low sensitivity, and HPV screening has a low specificity. This means that either cancers are missed, or women are over-treated. To improve performance outcomes, the concept of dual-stain cytology (CINtec ® PLUS Cytology test) has been introduced. In this approach, additional staining with p16/Ki-67 is performed in cases where cytology results are abnormal (LSIL or ASCUS) and/or HPV-positive. Another way to describe this approach might be "diagnostic" cytology. In order to assess the value of this "diagnostic cytology", a systematic literature review was conducted of dual-stain cytology performance across multiple studies until May 2016. In a Belgian screening population (women age 25-65 years), dual-stain cytology was significantly more sensitive (66%) and slightly less specific (-1.0%) than cytology. In the population referred to colposcopy or with abnormal cytology (ASCUS, LSIL), dual-staining showed a significantly higher increase in specificity, and a slightly lower sensitivity than HPV testing. Specificity gains resulted in fewer false positives and an increase in the number of correct referrals to colposcopy. Dual-staining with p16/Ki-67 cytology is an attractive biomarker approach for triage in cervical cancer screening. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Elastography for Thyroid Nodules: The Comparison of Diagnostic Performance on Transverse and Longitudinal Planes

    International Nuclear Information System (INIS)

    Moon, Hee Jung; Kwak, Jin Young; Kim, Eun Kyung

    2012-01-01

    To evaluate the diagnostic performance of elastography for thyroid nodules on the transverse and longitudinal planes. Gray scale ultrasonography (US), elastography on trans- verse and longitudinal planes, and fine needle aspiration biopsy for 78 thyroid nodules (malignant: 34 cases, benign: 44 cases) were performed. According to the Asteria criteria of elastography, scores 1 and 2 were classified as probably benign and scores 3 and 4 were classified as suspicious. Strain ratios on transverse and longitudinal planes were measured. Sensitivity, specificity, positive predictive value, negative predictive value, accuracy, and Az value (under the receiver operating characteristics curve) of elastography on transverse and longitudinal planes were calculated and compared. Scores 3 and 4 were more frequently seen in malignant nodules on the longitudinal plane (p value = 0.007), but not significantly seen on the transverse plane (p value = 0.160). Sensitivity, specificity, positive predictive value, negative predictive value, accuracy, and the Az value of elastography on the longitudinal plane were higher than those on the transverse plane, although Az values on the transverse and longtudinal planes were not statistically significant. Diagnostic performance of thyroid elastography, especially sensitivity, were higher on the longitudinal plane than the transverse plane

  14. Diagnostic performance of Contrast-enhanced CT in Pyrrolizidine Alkaloids-induced Hepatic Sinusoidal Obstructive Syndrome

    Science.gov (United States)

    Kan, Xuefeng; Ye, Jin; Rong, Xinxin; Lu, Zhiwen; Li, Xin; Wang, Yong; Yang, Ling; Xu, Keshu; Song, Yuhu; Hou, Xiaohua

    2016-01-01

    Hepatic sinusoidal obstruction syndrome (HSOS) can be caused by pyrrolizidine alkaloids(PAs)-containing herbals. Since PAs exposure is obscure and clinical presentation of HSOS is unspecific, it is challenge to establish the diagnosis of PAs-induced HSOS. Gynura segetum is one of the most wide-use herbals containing PAs. The aim of our study is to describe the features of contrast-enhanced computed tomography (CT) in gynura segetum-induced HSOS, and then determine diagnostic performance of radiological signs. We retrospectively analyzed medical records and CT images of HSOS patients (71 cases) and the controls (222 cases) enrolled from January 1, 2008, to Oct 31, 2015. The common findings of contrast CT in PAs-induced HSOS included: ascites (100%), hepatomegaly (78.87%), gallbladder wall thickening (86.96%), pleural effusion (70.42%), hepatic vein narrowing (87.32%), patchy liver enhancement (92.96%), and heterogeneous hypoattenuation (100%); of these signs, patchy enhancement and heterogeneous hypoattenuation were valuable features. Then, the result of diagnostic performance demonstrated that contrast CT possessed better performance in diagnosing PAs-induced HSOS compared with various parameters of Seattle criteria. In conclusion, the patients with PAs-induced HSOS display distinct radiologic features at CT-scan, which reveals that contrast-enhanced CT provides an effective noninvasive method for diagnosing PAs-induced HSOS. PMID:27897243

  15. Onboard autonomous mineral detectors for Mars rovers

    Science.gov (United States)

    Gilmore, M. S.; Bornstein, B.; Castano, R.; Merrill, M.; Greenwood, J.

    2005-12-01

    Mars rovers and orbiters currently collect far more data than can be downlinked to Earth, which reduces mission science return; this problem will be exacerbated by future rovers of enhanced capabilities and lifetimes. We are developing onboard intelligence sufficient to extract geologically meaningful data from spectrometer measurements of soil and rock samples, and thus to guide the selection, measurement and return of these data from significant targets at Mars. Here we report on techniques to construct mineral detectors capable of running on current and future rover and orbital hardware. We focus on carbonate and sulfate minerals which are of particular geologic importance because they can signal the presence of water and possibly life. Sulfates have also been discovered at the Eagle and Endurance craters in Meridiani Planum by the Mars Exploration Rover (MER) Opportunity and at other regions on Mars by the OMEGA instrument aboard Mars Express. We have developed highly accurate artificial neural network (ANN) and Support Vector Machine (SVM) based detectors capable of identifying calcite (CaCO3) and jarosite (KFe3(SO4)2(OH)6) in the visible/NIR (350-2500 nm) spectra of both laboratory specimens and rocks in Mars analogue field environments. To train the detectors, we used a generative model to create 1000s of linear mixtures of library end-member spectra in geologically realistic percentages. We have also augmented the model to include nonlinear mixing based on Hapke's models of bidirectional reflectance spectroscopy. Both detectors perform well on the spectra of real rocks that contain intimate mixtures of minerals, rocks in natural field environments, calcite covered by Mars analogue dust, and AVIRIS hyperspectral cubes. We will discuss the comparison of ANN and SVM classifiers for this task, technical challenges (weathering rinds, atmospheric compositions, and computational complexity), and plans for integration of these detectors into both the Coupled Layer

  16. Comparative Evaluation of the Diagnostic Performance of the Prototype Cepheid GeneXpert Ebola Assay

    Science.gov (United States)

    Jansen van Vuren, Petrus; Grobbelaar, Antoinette; Storm, Nadia; Conteh, Ousman; Konneh, Kelfala; Kamara, Abdul; Sanne, Ian

    2015-01-01

    The Ebola virus disease (EVD) outbreak in West Africa has highlighted an urgent need for point-of-care (POC) assays for the diagnosis of this devastating disease in resource-limited African countries. The diagnostic performance characteristics of a prototype Cepheid GeneXpert Ebola POC used to detect Ebola virus (EBOV) in stored serum and plasma samples collected from suspected EVD cases in Sierra Leone in 2014 and 2015 was evaluated. The GeneXpert Ebola POC is a self-contained single-cartridge automated system that targets the glycoprotein (GP) and nucleoprotein (NP) genes of EBOV and yields results within 90 min. Results from 281 patient samples were compared to the results of a TaqMan real-time reverse transcription-PCR (RT-PCR) targeting the polymerase gene and performed on two real-time PCR machines. Agreement between the three platforms was 100% at cycle threshold (CT) values of ≤34.99, but discordant results were noted between CT values of 35 and 45.The diagnostic sensitivity of the three platforms was 100% in 91 patient samples that were confirmed to be infectious by virus isolation. All three molecular platforms detected viral EBOV RNA in additional samples that did not contain viable EBOV. The analytical sensitivity of the GeneXpert Ebola POC for the detection of NP was higher, and comparable to that of polymerase gene detection, than that for the detection of GP when using a titrated laboratory stock of EBOV. There was no detectable cross-reactivity with other hemorrhagic fever viruses or arboviruses. The GeneXpert Ebola POC offers an easy to operate and sensitive diagnostic tool that can be used for the rapid screening of suspected EVD cases in treatment or in holding centers during EVD outbreaks. PMID:26637383

  17. Frequency of chest pain in primary care, diagnostic tests performed and final diagnoses.

    Science.gov (United States)

    Hoorweg, Beatrijs Bn; Willemsen, Robert Ta; Cleef, Lotte E; Boogaerts, Tom; Buntinx, Frank; Glatz, Jan Fc; Dinant, Geert Jan

    2017-11-01

    Observational study of patients with chest pain in primary care: determination of incidence, referral rate, diagnostic tests and (agreement between) working and final diagnoses. 118 general practitioners (GPs) in the Netherlands and Belgium recorded all patient contacts during  2weeks. Furthermore, patients presenting with chest pain were registered extensively. A follow-up form was filled in after 30 days. 22 294 patient contacts were registered. In 281 (1.26%), chest pain was a reason for consulting the GP (mean age for men 54.4/women 53 years). In this cohort of 281 patients, in 38.1% of patients, acute coronary syndrome (ACS) was suspected at least temporarily during consultation, 40.2% of patients were referred to secondary care and 512 diagnostic tests were performed by GPs and consulted specialists. Musculoskeletal pain was the most frequent working (26.1%) and final diagnoses (33.1%). Potentially life-threatening diseases as final diagnosis (such as myocardial infarction) accounted for 8.4% of all chest pain cases. In 23.1% of cases, a major difference between working and final diagnoses was found, in 0.7% a severe disease was initially missed by the GP. Chest pain was present in 281 patients (1.26% of all consultations). Final diagnoses were mostly non-life-threatening. Nevertheless, in 8.4% of patients with chest pain, life-threatening underlying causes were identified. This seems reflected in the magnitude and wide variety of diagnostic tests performed in these patients by GPs and specialists, in the (safe) overestimation of life-threatening diseases by GPs at initial assessment and in the high referral rate we found. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  18. Use of proficiency samples to assess diagnostic laboratories in France performing a Trichinella digestion assay.

    Science.gov (United States)

    Vallée, Isabelle; Macé, Pauline; Forbes, Lorry; Scandrett, Brad; Durand, Benoit; Gajadhar, Alvin; Boireau, Pascal

    2007-07-01

    Routine diagnosis of animal trichinellosis for food safety and trade relies on a method of artificial digestion to free Trichinella muscle larvae from meat for subsequent identification by microscopy. As part of a quality control system, the French National Reference Laboratory (NRL) initiated ring trials to determine the sensitivity of the test performed in the 72 routine diagnostic laboratories in France. A method was devised to obtain calibrated meat samples containing known numbers of capsules with Trichinella spiralis muscle larvae. This method was based on an incomplete artificial digestion of Trichinella-infected mice carcasses to allow the collection of intact Trichinella capsules. Capsules were placed into a meatball of 100 +/- 2 g of pork and horsemeat to produce proficiency samples. Three categories of samples were prepared: small (3 to 5 capsules), medium (7 to 10), and large (12 to 15). The sensitivity was expressed as the percentage of muscle larvae recovered from each proficiency sample. Reproducibility was tested with ring trials organized between two NRLs (France and Canada), and a reference sensitivity of 84.9% was established. National ring trials were then organized in France, with the 72 routine diagnostic laboratories each receiving four proficiency samples per session. After five sessions, an improvement in the digest test sensitivity was observed. Results at the fifth session indicated sensitivities of 78.60% +/- 23.70%, 81.19% +/- 19.59%, and 80.52% +/- 14.71% muscle larvae for small, medium, and large samples, respectively. This study supports the use of proficiency samples to accurately evaluate the performance of routine diagnostic laboratories that conduct digestion tests for animal trichinellosis diagnosis.

  19. Diagnostic Performance of Self-Assessment for Constipation in Patients With Long-Term Opioid Treatment.

    Science.gov (United States)

    Tafelski, Sascha; Bellin, Felicitas; Denke, Claudia; Beutlhauser, Torsten; Fritzsche, Thomas; West, Christina; Schäfer, Michael

    2015-12-01

    Constipation is a prevalent comorbidity affecting ∼50% of patients with long-term opioid therapy. In clinical routine different diagnostic instruments are in use to identify patients under risk. The aim of this study was to assess the diagnostic performance of an 11-item Likert scale for constipation used as a self-assessment in opioid-treated patients. This trial was conducted as a retrospective cohort study in Berlin, Germany. Patients with long-term opioid therapy treated in 2 university-affiliated outpatient pain facilities at the Charité hospital were included from January 2013 to August 2013. Constipation was rated in a self-assessment using a numeric rating scale from 0 to 10 (Con-NRS) and compared with results from a structured assessment based on ROME-III criteria. Altogether, 171 patients were included. Incidence of constipation was 49% of patients. The receiver-operating characteristic of Con-NRS achieved an area under the curve of 0.814 (AUC 95% confidence interval 0.748-0.880, P < 0.001). Con-NRS ≥ 1 achieved sensitivity and specificity of 79.7% and 77.2%, respectively. The positive predictive value and the negative predictive value were 70.3% and 81.6%, respectively. Overall diagnostic performance of a concise 11-item Likert scale for constipation was moderate. Although patients with long-term opioid therapy are familiar with numeric rating scales, a significant number of patients with constipation were not identified. The instrument may be additionally useful to facilitate individualized therapeutic decision making and to control therapeutic success when measured repetitively.

  20. The SUCCESS model for laboratory performance and execution of rapid molecular diagnostics in patients with sepsis.

    Science.gov (United States)

    Dekmezian, Mhair; Beal, Stacy G; Damashek, Mary Jane; Benavides, Raul; Dhiman, Neelam

    2015-04-01

    Successful performance and execution of rapid diagnostics in a clinical laboratory hinges heavily on careful validation, accurate and timely communication of results, and real-time quality monitoring. Laboratories must develop strategies to integrate diagnostics with stewardship and evidence-based clinical practice guidelines. We present a collaborative SUCCESS model for execution and monitoring of rapid sepsis diagnostics to facilitate timely treatment. Six months after execution of the Verigene Gram-Positive Blood Culture (BC-GP) and the AdvanDx PNA-FISH assays, data were collected on 579 and 28 episodes of bacteremia and fungemia, respectively. Clinical testing was executed using a SUCCESS model comprising the following components: stewardship, utilization of resources, core strategies, concierge services, education, support, and surveillance. Stewardship needs were identified by evaluating the specialty services benefiting from new testing. Utilization of resources was optimized by reviewing current treatment strategies and antibiogram and formulary options. Core strategies consisted of input from infectious disease leadership, pharmacy, and laboratory staff. Concierge services included automated Micro-eUpdate and physician-friendly actionable reports. Education modules were user-specific, and support was provided through a dedicated 24/7 microbiology hotline. Surveillance was performed by daily audit by the director. Using the SUCCESS model, the turnaround time for the detailed report with actionable guidelines to the physician was ∼3 hours from the time of culture positivity. The overall correlation between rapid methods and culture was 94% (546/579). Discrepant results were predominantly contaminants such as a coagulase-negative staphylococci or viridans streptococci in mixed cultures. SUCCESS is a cost-effective and easily adaptable model for clinical laboratories with limited stewardship resources.

  1. Volume perfusion CT imaging of cerebral vasospasm: diagnostic performance of different perfusion maps

    Energy Technology Data Exchange (ETDEWEB)

    Othman, Ahmed E. [RWTH Aachen University, Department of Diagnostic and Interventional Neuroradiology, Aachen (Germany); Eberhard Karls University Tuebingen, University Hospital Tuebingen, Department for Diagnostic and Interventional Radiology, Tuebingen (Germany); Afat, Saif; Nikoubashman, Omid; Mueller, Marguerite; Wiesmann, Martin; Brockmann, Carolin [RWTH Aachen University, Department of Diagnostic and Interventional Neuroradiology, Aachen (Germany); Schubert, Gerrit Alexander [RWTH Aachen University, Department of Neurosurgery, Aachen (Germany); Bier, Georg [Eberhard Karls University Tuebingen, University Hospital Tuebingen, Department for Diagnostic and Interventional Neuroradiology, Tuebingen (Germany); Brockmann, Marc A. [RWTH Aachen University, Department of Diagnostic and Interventional Neuroradiology, Aachen (Germany); University Hospital Mainz, Department of Neuroradiology, Mainz (Germany)

    2016-08-15

    In this study, we aimed to evaluate the diagnostic performance of different volume perfusion CT (VPCT) maps regarding the detection of cerebral vasospasm compared to angiographic findings. Forty-one datasets of 26 patients (57.5 ± 10.8 years, 18 F) with subarachnoid hemorrhage and suspected cerebral vasospasm, who underwent VPCT and angiography within 6 h, were included. Two neuroradiologists independently evaluated the presence and severity of vasospasm on perfusion maps on a 3-point Likert scale (0 - no vasospasm, 1 - vasospasm affecting <50 %, 2 - vasospasm affecting >50 % of vascular territory). A third neuroradiologist independently assessed angiography for the presence and severity of vasospasm on a 3-point Likert scale (0 - no vasospasm, 1 - vasospasm affecting < 50 %, 2 - vasospasm affecting > 50 % of vessel diameter). Perfusion maps of cerebral blood volume (CBV), cerebral blood flow (CBF), mean transit time (MTT), and time to drain (TTD) were evaluated regarding diagnostic accuracy for cerebral vasospasm with angiography as reference standard. Correlation analysis of vasospasm severity on perfusion maps and angiographic images was performed. Furthermore, inter-reader agreement was assessed regarding findings on perfusion maps. Diagnostic accuracy for TTD and MTT was significantly higher than for all other perfusion maps (TTD, AUC = 0.832; MTT, AUC = 0.791; p < 0.001). TTD revealed higher sensitivity than MTT (p = 0.007). The severity of vasospasm on TTD maps showed significantly higher correlation levels with angiography than all other perfusion maps (p ≤ 0.048). Inter-reader agreement was (almost) perfect for all perfusion maps (kappa ≥ 0.927). The results of this study indicate that TTD maps have the highest sensitivity for the detection of cerebral vasospasm and highest correlation with angiography regarding the severity of vasospasm. (orig.)

  2. A Meta-analysis for the Diagnostic Performance of Transient Elastography for Clinically Significant Portal Hypertension.

    Science.gov (United States)

    You, Myung-Won; Kim, Kyung Won; Pyo, Junhee; Huh, Jimi; Kim, Hyoung Jung; Lee, So Jung; Park, Seong Ho

    2017-01-01

    We aimed to evaluate the correlation between liver stiffness measurement using transient elastography (TE-LSM) and hepatic venous pressure gradient and the diagnostic performance of TE-LSM in assessing clinically significant portal hypertension through meta-analysis. Eleven studies were included from thorough literature research and selection processes. The summary correlation coefficient was 0.783 (95% confidence interval [CI], 0.737-0.823). Summary sensitivity, specificity and area under the hierarchical summary receiver operating characteristic curve (AUC) were 87.5% (95% CI, 75.8-93.9%), 85.3 % (95% CI, 76.9-90.9%) and 0.9, respectively. The subgroup with low cut-off values of 13.6-18 kPa had better summary estimates (sensitivity 91.2%, specificity 81.3% and partial AUC 0.921) than the subgroup with high cut-off values of 21-25 kPa (sensitivity 71.2%, specificity 90.9% and partial AUC 0.769). In summary, TE-LSM correlated well with hepatic venous pressure gradient and represented good diagnostic performance in diagnosing clinically significant portal hypertension. For use as a sensitive screening tool, we propose using low cut-off values of 13.6-18 kPa in TE-LSM. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  3. Diagnostic performance of shear wave elastography of the breast according to scanning orientation.

    Science.gov (United States)

    Kim, Solip; Choi, SeonHyeong; Choi, Yoonjung; Kook, Shin-Ho; Park, Hee Jin; Chung, Eun Chul

    2014-10-01

    To evaluate the influence of the scanning orientation on diagnostic performance measured by the mean elasticity, maximum elasticity, and fat-to-lesion elasticity ratio on ultrasound-based shear wave elastography in differentiating breast cancers from benign lesions. In this study, a total of 260 breast masses from 235 consecutive patients were observed from March 2012 to November 2012. For each lesion, the mean elasticity value, maximum elasticity value, and fat-to-lesion ratio were measured along two orthogonal directions, and all values were compared with pathologic results. There were 59 malignant and 201 benign lesions. Malignant masses showed higher mean elasticity, maximum elasticity, and fat-to-lesion ratio values than benign lesions (P masses; and mean elasticity, 0.392, for anterior mammary fat. Mean elasticity, maximum elasticity, and fat-to-lesion elasticity ratio values were helpful in differentiating benign and malignant breast masses. The scanning orientation did not significantly affect the diagnostic performance of shear wave elastography for breast masses. © 2014 by the American Institute of Ultrasound in Medicine.

  4. Wireless Infrastructure for Performing Monitoring, Diagnostics, and Control HVAC and Other Energy-Using Systems in Small Commercial Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Patrick O' Neill

    2009-06-30

    This project focused on developing a low-cost wireless infrastructure for monitoring, diagnosing, and controlling building systems and equipment. End users receive information via the Internet and need only a web browser and Internet connection. The system used wireless communications for: (1) collecting data centrally on site from many wireless sensors installed on building equipment, (2) transmitting control signals to actuators and (3) transmitting data to an offsite network operations center where it is processed and made available to clients on the Web (see Figure 1). Although this wireless infrastructure can be applied to any building system, it was tested on two representative applications: (1) monitoring and diagnostics for packaged rooftop HVAC units used widely on small commercial buildings and (2) continuous diagnosis and control of scheduling errors such as lights and equipment left on during unoccupied hours. This project developed a generic infrastructure for performance monitoring, diagnostics, and control, applicable to a broad range of building systems and equipment, but targeted specifically to small to medium commercial buildings (an underserved market segment). The proposed solution is based on two wireless technologies. The first, wireless telemetry, is used for cell phones and paging and is reliable and widely available. This risk proved to be easily managed during the project. The second technology is on-site wireless communication for acquiring data from sensors and transmitting control signals. The technology must enable communication with many nodes, overcome physical obstructions, operate in environments with other electrical equipment, support operation with on-board power (instead of line power) for some applications, operate at low transmission power in license-free radio bands, and be low cost. We proposed wireless mesh networking to meet these needs. This technology is relatively new and has been applied only in research and tests

  5. Performance, diagnostics, controls and plans for the gyrotron system on the DIII-D tokamak

    Directory of Open Access Journals (Sweden)

    Ponce D.M.

    2012-09-01

    Full Text Available The DIII-D ECH complex is being upgraded with three new depressed collector gyrotrons. The performance of the existing system has been very good. As more gyrotrons having higher power are added to the system, diagnostics of gyrotron operation, optimization of the performance and qualification of components for higher power become more important. A new FPGA-based gyrotron control system is being installed, additional capabilities for rapid real time variation of the rf injection angles by the DIII-D Plasma Control System are being tested and infrastructure enhancements are being completed. Longer term plans continue to include ECH as a major component in the DIII-D heating and current drive capabilities.

  6. Onboard Short Term Plan Viewer

    Science.gov (United States)

    Hall, Tim; LeBlanc, Troy; Ulman, Brian; McDonald, Aaron; Gramm, Paul; Chang, Li-Min; Keerthi, Suman; Kivlovitz, Dov; Hadlock, Jason

    2011-01-01

    Onboard Short Term Plan Viewer (OSTPV) is a computer program for electronic display of mission plans and timelines, both aboard the International Space Station (ISS) and in ISS ground control stations located in several countries. OSTPV was specifically designed both (1) for use within the limited ISS computing environment and (2) to be compatible with computers used in ground control stations. OSTPV supplants a prior system in which, aboard the ISS, timelines were printed on paper and incorporated into files that also contained other paper documents. Hence, the introduction of OSTPV has both reduced the consumption of resources and saved time in updating plans and timelines. OSTPV accepts, as input, the mission timeline output of a legacy, print-oriented, UNIX-based program called "Consolidated Planning System" and converts the timeline information for display in an interactive, dynamic, Windows Web-based graphical user interface that is used by both the ISS crew and ground control teams in real time. OSTPV enables the ISS crew to electronically indicate execution of timeline steps, launch electronic procedures, and efficiently report to ground control teams on the statuses of ISS activities, all by use of laptop computers aboard the ISS.

  7. HIV misdiagnosis in sub-Saharan Africa: performance of diagnostic algorithms at six testing sites

    Science.gov (United States)

    Kosack, Cara S.; Shanks, Leslie; Beelaert, Greet; Benson, Tumwesigye; Savane, Aboubacar; Ng’ang’a, Anne; Andre, Bita; Zahinda, Jean-Paul BN; Fransen, Katrien; Page, Anne-Laure

    2017-01-01

    Abstract Introduction: We evaluated the diagnostic accuracy of HIV testing algorithms at six programmes in five sub-Saharan African countries. Methods: In this prospective multisite diagnostic evaluation study (Conakry, Guinea; Kitgum, Uganda; Arua, Uganda; Homa Bay, Kenya; Doula, Cameroun and Baraka, Democratic Republic of Congo), samples from clients (greater than equal to five years of age) testing for HIV were collected and compared to a state-of-the-art algorithm from the AIDS reference laboratory at the Institute of Tropical Medicine, Belgium. The reference algorithm consisted of an enzyme-linked immuno-sorbent assay, a line-immunoassay, a single antigen-enzyme immunoassay and a DNA polymerase chain reaction test. Results: Between August 2011 and January 2015, over 14,000 clients were tested for HIV at 6 HIV counselling and testing sites. Of those, 2786 (median age: 30; 38.1% males) were included in the study. Sensitivity of the testing algorithms ranged from 89.5% in Arua to 100% in Douala and Conakry, while specificity ranged from 98.3% in Doula to 100% in Conakry. Overall, 24 (0.9%) clients, and as many as 8 per site (1.7%), were misdiagnosed, with 16 false-positive and 8 false-negative results. Six false-negative specimens were retested with the on-site algorithm on the same sample and were found to be positive. Conversely, 13 false-positive specimens were retested: 8 remained false-positive with the on-site algorithm. Conclusions: The performance of algorithms at several sites failed to meet expectations and thresholds set by the World Health Organization, with unacceptably high rates of false results. Alongside the careful selection of rapid diagnostic tests and the validation of algorithms, strictly observing correct procedures can reduce the risk of false results. In the meantime, to identify false-positive diagnoses at initial testing, patients should be retested upon initiating antiretroviral therapy. PMID:28691437

  8. An Evaluation of the Performance Diagnostic Checklist-Human Services (PDC-HS) Across Domains.

    Science.gov (United States)

    Wilder, David A; Lipschultz, Joshua; Gehrman, Chana

    2018-06-01

    The Performance Diagnostic Checklist-Human Services (PDC-HS) is an informant-based tool designed to assess the environmental variables that contribute to poor employee performance in human service settings. Although the PDC-HS has been shown to effectively identify variables contributing to problematic performance, interventions based on only two of the four PDC-HS domains have been evaluated to date. In addition, the extent to which PDC-HS-indicated interventions are more effective than nonindicated interventions for two domains remains unclear. In the current study, we administered the PDC-HS to supervisors to assess the variables contributing to infrequent teaching of verbal operants and use of a timer by therapists at a center-based autism treatment program. Each of the four PDC-HS domains was identified as contributing to poor performance for at least one therapist. We then evaluated PDC-HS-indicated interventions for each domain. In addition, to assess the predictive validity of the tool, we evaluated various nonindicated interventions prior to implementing a PDC-HS-indicated intervention for two of the four domains. Results suggest that the PDC-HS-indicated interventions were effective across all four domains and were more effective than the nonindicated interventions for the two domains for which they were evaluated. Results are discussed in terms of the utility of the PDC-HS to identify appropriate interventions to manage therapist performance in human service settings.

  9. 40 CFR 86.1806-01 - On-board diagnostics.

    Science.gov (United States)

    2010-07-01

    ... Section 86.1806-01 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... available on demand through the serial port on the standardized data link connector, if the information is... or components during malfunction conditions if such evaluation would result in a risk to safety or...

  10. 40 CFR 86.005-17 - On-board diagnostics.

    Science.gov (United States)

    2010-07-01

    ... Section 86.005-17 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... the serial port on the standardized data link connector, if the information is available to the on... systems or components during malfunction conditions if such evaluation would result in a risk to safety or...

  11. 40 CFR 86.1806-04 - On-board diagnostics.

    Science.gov (United States)

    2010-07-01

    ... (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES (CONTINUED) General... conform with the following Society of Automotive Engineers (SAE) standards and/or the following..., definitions and abbreviations shall be formatted according to SAE J1930 “Electrical/Electronic Systems...

  12. Diagnostic performance of a Lattice Boltzmann-based method for CT-based fractional flow reserve.

    Science.gov (United States)

    Giannopoulos, Andreas A; Tang, Anji; Ge, Yin; Cheezum, Michael K; Steigner, Michael L; Fujimoto, Shinichiro; Kumamaru, Kanako K; Chiappino, Dante; Della Latta, Daniele; Berti, Sergio; Chiappino, Sara; Rybicki, Frank J; Melchionna, Simone; Mitsouras, Dimitrios

    2018-02-20

    Fractional flow reserve (FFR) estimated from coronary computed tomography angiography (CT-FFR) offers non-invasive detection of lesion-specific ischaemia. We aimed to develop and validate a fast CT-FFR algorithm utilising the Lattice Boltzmann method for blood flow simulation (LBM CT-FFR). Sixty-four patients with clinically indicated CTA and invasive FFR measurement from three institutions were retrospectively analysed. CT-FFR was performed using an onsite tool interfacing with a commercial Lattice Boltzmann fluid dynamics cloud-based platform. Diagnostic accuracy of LBM CT-FFR ≤0.8 and percent diameter stenosis >50% by CTA to detect invasive FFR ≤0.8 were compared using area under the receiver operating characteristic curve (AUC). Sixty patients successfully underwent LBM CT-FFR analysis; 29 of 73 lesions in 69 vessels had invasive FFR ≤0.8. Total time to perform LBM CT-FFR was 40±10 min. Compared to invasive FFR, LBM CT-FFR had good correlation (r=0.64), small bias (0.009) and good limits of agreement (-0.223 to 0.206). The AUC of LBM CT-FFR (AUC=0.894, 95% confidence interval [CI]: 0.792-0.996) was significantly higher than CTA (AUC=0.685, 95% CI: 0.576-0.794) to detect FFR ≤0.8 (p=0.0021). Per-lesion specificity, sensitivity, and accuracy of LBM CT-FFR were 97.7%, 79.3%, and 90.4%, respectively. LBM CT-FFR has very good diagnostic accuracy to detect lesion-specific ischaemia (FFR ≤0.8) and can be performed in less than one hour.

  13. Xanthogranulomatous cholecystitis: Diagnostic performance of CT to differentiate from gallbladder cancer

    Energy Technology Data Exchange (ETDEWEB)

    Goshima, Satoshi, E-mail: gossy@par.odn.ne.j [Department of Radiology, University of Pittsburgh Medical Center, Lothrop St., Pittsburgh, PA 15213 (United States); Department of Radiology, Gifu University School of Medicine, 1-1 Yanagido, Gifu 501-1194 (Japan); Chang, Samuel; Wang, Jin Hong [Department of Radiology, University of Pittsburgh School of Medicine, 3362 Fifth Ave., Pittsburgh, PA15213 (United States); Kanematsu, Masayuki [Department of Radiology, Gifu University School of Medicine, 1-1 Yanagido, Gifu 501-1194 (Japan); Department of Radiology Services, Gifu University School of Medicine, 1-1- Yanagido, Gifu 501-1194 (Japan); Bae, Kyongtae T. [Department of Radiology, University of Pittsburgh School of Medicine, 3362 Fifth Ave., Pittsburgh, PA15213 (United States); Federle, Michael P. [Department of Radiology, University of Pittsburgh Medical Center, Lothrop St., Pittsburgh, PA 15213 (United States); Department of Radiology, Stanford University Medical Center, 300 Pasteur Drive, Stanford, CA 94305-5105 (United States)

    2010-06-15

    Purpose: To retrospectively evaluate CT findings of xanthogranulomatous cholecystitis (XGC) and to measure diagnostic performance for distinguishing it from gallbladder (GB) cancer. Methods and materials: Our institutional review board approved this retrospective study. Three blinded radiologists, first independently and then in consensus, retrospectively evaluated postcontrast CT images of 35 patients with histopathologically proved XGC and GB cancer, all of whom subsequently had cholecystectomy. These included 18 patients with XGC (13 male, 5 female; age range, 35-84, mean 63 years) and 17 with GB cancer (6 male, 11 female; age range, 45-95, mean 69). Differences in CT findings between XGC and GB cancer and diagnostic performances for each CT finding were calculated. Sensitivity, specificity, and accuracy were calculated for each radiologist and observer performance was also determined by receiver-operating-characteristic curve analysis. Results: Five CT findings showed significant differences between XGC and GB cancer. Sensitivity, specificity, and accuracy of each finding for the differentiation of XGC were 89%, 65%, 77% with diffuse GB wall thickening, 67%, 82%, 74% with a continuous mucosal line, 61%, 71%, 66% with intra-mural hypo-attenuated nodules, 72%, 77%, 74% with absence of macroscopic hepatic invasion, and 67%, 71%, 69% with absence of intra-hepatic bile duct dilatation, respectively. When at least three of these five CT findings were observed in combination, sensitivity, specificity, and accuracy were 83%, 100% and 91%, respectively. Sensitivities, specificities and Az values for the differentiation of XGC from GB cancer were 83%, 88%, 0.94 for reader 1, 78%, 88%, 0.93 for reader 2, and 78%, 82%, 0.84 for reader 3. Conclusions: The combination of three of the five CT findings that are common with XGC can provide excellent accuracy for the differentiation of XGC and GB cancer.

  14. Diagnostic performance of dual-energy CT stress myocardial perfusion imaging: direct comparison with cardiovascular MRI.

    Science.gov (United States)

    Ko, Sung Min; Song, Meong Gun; Chee, Hyun Kun; Hwang, Hweung Kon; Feuchtner, Gudrun Maria; Min, James K

    2014-12-01

    The purpose of this study was to assess the diagnostic performance of stress perfusion dual-energy CT (DECT) and its incremental value when used with coronary CT angiography (CTA) for identifying hemodynamically significant coronary artery disease. One hundred patients with suspected or known coronary artery disease without chronic myocardial infarction detected with coronary CTA underwent stress perfusion DECT, stress cardiovascular perfusion MRI, and invasive coronary angiography (ICA). Stress perfusion DECT and cardiovascular stress perfusion MR images were used for detecting perfusion defects. Coronary CTA and ICA were evaluated in the detection of ≥50% coronary stenosis. The diagnostic performance of coronary CTA for detecting hemo-dynamically significant stenosis was assessed before and after stress perfusion DECT on a per-vessel basis with ICA and cardiovascular stress perfusion MRI as the reference standard. The performance of stress perfusion DECT compared with cardiovascular stress perfusion MRI on a per-vessel basis in the detection of perfusion defects was sensitivity, 89%; specificity, 74%; positive predictive value, 73%; negative predictive value, 90%. Per segment, these values were sensitivity, 76%; specificity, 80%; positive predictive value, 63%; and negative predictive value, 88%. Compared with ICA and cardiovascular stress perfusion MRI per vessel territory the sensitivity, specificity, positive predictive value, and negative predictive value of coronary CTA were 95%, 61%, 61%, and 95%. The values for stress perfusion DECT were 92%, 72%, 68%, and 94%. The values for coronary CTA and stress perfusion DECT were 88%, 79%, 73%, and 91%. The ROC AUC increased from 0.78 to 0.84 (p=0.02) with the use of coronary CTA and stress perfusion DECT compared with coronary CTA alone. Stress perfusion DECT plays a complementary role in enhancing the accuracy of coronary CTA for identifying hemodynamically significant coronary stenosis.

  15. Development of GEM detector for plasma diagnostics application: simulations addressing optimization of its performance

    Science.gov (United States)

    Chernyshova, M.; Malinowski, K.; Kowalska-Strzęciwilk, E.; Czarski, T.; Linczuk, P.; Wojeński, A.; Krawczyk, R. D.

    2017-12-01

    The advanced Soft X-ray (SXR) diagnostics setup devoted to studies of the SXR plasma emissivity is at the moment a highly relevant and important for ITER/DEMO application. Especially focusing on the energy range of tungsten emission lines, as plasma contamination by W and its transport in the plasma must be understood and monitored for W plasma-facing material. The Gas Electron Multiplier, with a spatial and energy-resolved photon detecting chamber, based SXR radiation detection system under development by our group may become such a diagnostic setup considering and solving many physical, technical and technological aspects. This work presents the results of simulations aimed to optimize a design of the detector's internal chamber and its performance. The study of the effect of electrodes alignment allowed choosing the gap distances which maximizes electron transmission and choosing the optimal magnitudes of the applied electric fields. Finally, the optimal readout structure design was identified suitable to collect a total formed charge effectively, basing on the range of the simulated electron cloud at the readout plane which was in the order of ~ 2 mm.

  16. Diagnostic value of performing endocervical curettage at the time of colposcopy procedure; a systematic review

    Directory of Open Access Journals (Sweden)

    Shabnam Imannezhad

    2016-03-01

    Full Text Available Introduction: The importance of high-grade cervical intraepithelial neoplasia (CIN as a precursor to invasive cervical cancer suggests a considerable need for accurate screening of the patients for the risk of these lesions. This systematic review aimed to study the diagnostic significance of endocervical curettage (ECC at the time of colposcopy in the detection of CIN 2, 3, and preinvasive lesions.Methods: PubMed was searched to obtain the relevant articles based on the following search term: (endocervical curettage OR ECC AND colposcopy. The most relevant articles were included after studying the title, abstract, and full text of the obtained articles at initial search. Only English language articles published after 1992 with at least 500 patients were included in this study.Result: Among 300 articles identified by the first search, only seven articles were in line with the purpose of this systematic review. Majority of the included studies were retrospective observational studies.Conclusion: Performing ECC has higher sensitivity in women older than 40 years and those with unsatisfactory colposcopy results. However exact diagnostic usefulness of ECC at the time of colposcopy needs to be investigated in further studies.

  17. Diagnostic Performance of Narrow Band Imaging for Nasopharyngeal Cancer: A Systematic Review and Meta-analysis.

    Science.gov (United States)

    Sun, Changling; Zhang, Yayun; Han, Xue; Du, Xiaodong

    2018-03-01

    Objective The purposes of this study were to verify the effectiveness of the narrow band imaging (NBI) system in diagnosing nasopharyngeal cancer (NPC) as compared with white light endoscopy. Data Sources PubMed, Cochrane Library, EMBASE, CNKI, and Wan Fang databases. Review Methods Data analyses were performed with Meta-Disc. The updated Quality Assessment of Diagnostic Accuracy Studies-2 tool was used to assess study quality and potential bias. Publication bias was assessed with a Deeks asymmetry test. The registry number of the protocol published on PROSPERO is CRD42015026244. Results This meta-analysis included 10 studies of 1337 lesions. For NBI diagnosis of NPC, the pooled values were as follows: sensitivity, 0.83 (95% CI, 0.80-0.86); specificity, 0.91 (95% CI, 0.89-0.93); positive likelihood ratio, 8.82 (95% CI, 5.12-15.21); negative likelihood ratio, 0.18 (95% CI, 0.12-0.27); and diagnostic odds ratio, 65.73 (95% CI, 36.74-117.60). The area under the curve was 0.9549. For white light endoscopy in diagnosing NPC, the pooled values were as follows: sensitivity, 0.79 (95% CI, 0.75-0.83); specificity, 0.87 (95% CI, 0.84-0.90); positive likelihood ratio, 5.02 (95% CI, 1.99-12.65); negative likelihood ratio, 0.34 (95% CI, 0.24-0.49); and diagnostic odds ratio, 16.89 (95% CI, 5.98-47.66). The area under the curve was 0.8627. The evaluation of heterogeneity, calculated per the diagnostic odds ratio, gave an I 2 of 0.326. No marked publication bias ( P = .68) existed in this meta-analysis. Conclusion The sensitivity and specificity of NBI for the diagnosis of NPC are similar to those of white light endoscopy, and the potential value of NBI for the diagnosis of NPC needs to be validated further.

  18. Memory-Efficient Onboard Rock Segmentation

    Science.gov (United States)

    Burl, Michael C.; Thompson, David R.; Bornstein, Benjamin J.; deGranville, Charles K.

    2013-01-01

    Rockster-MER is an autonomous perception capability that was uploaded to the Mars Exploration Rover Opportunity in December 2009. This software provides the vision front end for a larger software system known as AEGIS (Autonomous Exploration for Gathering Increased Science), which was recently named 2011 NASA Software of the Year. As the first step in AEGIS, Rockster-MER analyzes an image captured by the rover, and detects and automatically identifies the boundary contours of rocks and regions of outcrop present in the scene. This initial segmentation step reduces the data volume from millions of pixels into hundreds (or fewer) of rock contours. Subsequent stages of AEGIS then prioritize the best rocks according to scientist- defined preferences and take high-resolution, follow-up observations. Rockster-MER has performed robustly from the outset on the Mars surface under challenging conditions. Rockster-MER is a specially adapted, embedded version of the original Rockster algorithm ("Rock Segmentation Through Edge Regrouping," (NPO- 44417) Software Tech Briefs, September 2008, p. 25). Although the new version performs the same basic task as the original code, the software has been (1) significantly upgraded to overcome the severe onboard re source limitations (CPU, memory, power, time) and (2) "bulletproofed" through code reviews and extensive testing and profiling to avoid the occurrence of faults. Because of the limited computational power of the RAD6000 flight processor on Opportunity (roughly two orders of magnitude slower than a modern workstation), the algorithm was heavily tuned to improve its speed. Several functional elements of the original algorithm were removed as a result of an extensive cost/benefit analysis conducted on a large set of archived rover images. The algorithm was also required to operate below a stringent 4MB high-water memory ceiling; hence, numerous tricks and strategies were introduced to reduce the memory footprint. Local filtering

  19. On-board Data Mining

    Science.gov (United States)

    Tanner, Steve; Stein, Cara; Graves, Sara J.

    Networks of remote sensors are becoming more common as technology improves and costs decline. In the past, a remote sensor was usually a device that collected data to be retrieved at a later time by some other mechanism. This collected data were usually processed well after the fact at a computer greatly removed from the in situ sensing location. This has begun to change as sensor technology, on-board processing, and network communication capabilities have increased and their prices have dropped. There has been an explosion in the number of sensors and sensing devices, not just around the world, but literally throughout the solar system. These sensors are not only becoming vastly more sophisticated, accurate, and detailed in the data they gather but they are also becoming cheaper, lighter, and smaller. At the same time, engineers have developed improved methods to embed computing systems, memory, storage, and communication capabilities into the platforms that host these sensors. Now, it is not unusual to see large networks of sensors working in cooperation with one another. Nor does it seem strange to see the autonomous operation of sensorbased systems, from space-based satellites to smart vacuum cleaners that keep our homes clean and robotic toys that help to entertain and educate our children. But access to sensor data and computing power is only part of the story. For all the power of these systems, there are still substantial limits to what they can accomplish. These include the well-known limits to current Artificial Intelligence capabilities and our limited ability to program the abstract concepts, goals, and improvisation needed for fully autonomous systems. But it also includes much more basic engineering problems such as lack of adequate power, communications bandwidth, and memory, as well as problems with the geolocation and real-time georeferencing required to integrate data from multiple sensors to be used together.

  20. Diagnostic performance of PET/MR in the evaluation of active inflammation in Crohn disease.

    Science.gov (United States)

    Catalano, Onofrio Antonio; Wu, Vincent; Mahmood, Umar; Signore, Alberto; Vangel, Mark; Soricelli, Andrea; Salvatore, Marco; Gervais, Debra; Rosen, Bruce R

    2018-01-01

    This study investigates the performance of PET/MR versus each sub-modality alone in the assessment of active inflammation in patients with Crohn disease, when compared to surgery as standard of reference. Sensitivity for detecting active inflammation was 91.5% for PET, 80% for MR, and 88% for PET/MR. Specificity for active inflammation was 74% for PET, 87% for MR, and 93% for PET/MR. Diagnostic accuracy was 84% for PET, 83% for MR, and 91% for PET/MR. In conclusion, PET/MR is significantly more accurate than either sub-modality alone and more specific than PET alone in the detection of active inflammation in patients with Crohn disease.

  1. A Diagnostic Comparison of Turkish and Korean Students’ Mathematics Performances on the TIMSS 2011 Assessment

    Directory of Open Access Journals (Sweden)

    Sedat Şen

    2015-11-01

    Full Text Available The purpose of the present study was to analyze an international large-scale data set using a cognitive assessment approach. Although some researchers question the usefulness of international large-scale assessments (e.g., TIMSS, participating countries have continued to use the results from these large-scale assessments to improve their curricula and teaching methods. Despite the common reporting practice—single-score—in these large scale assessments gives useful insights about students’ overall performances, they still lack diagnostic information. Cognitive diagnosis models (CDMs were developed to provide more feedback on students’ cognitive strengths and weaknesses. This study retrofitted the TIMSS 2011 eighth grade mathematics assessment by applying a specific CDM called the DINA (the deterministic, inputs, noisy, “and” gate model to data from South Korea and Turkey. Results of the DINA model were used to make a detailed comparison between students of these two countries.

  2. Reproducibility and diagnostic performance of shear wave elastography in evaluating breast solid mass.

    Science.gov (United States)

    Hong, Sun; Woo, Ok Hee; Shin, Hye Seon; Hwang, Soon-Young; Cho, Kyu Ran; Seo, Bo Kyoung

    Shear wave elastography (SWE) was performed independently by two radiologists in 264 solid breast masses. The images were reviewed for color overlay pattern (COP) classification by the two radiologists, double blinded to any information. The interobserver agreement of the COP was almost perfect (κ=0.908) and high in E max (ICC=0.89). The AUC value of the COP (0.954) was significantly higher than that of E max (0.915) (p=0.002) but not significantly different from that of E max combined with COP (0.957) (p=0.098). The SWE color overlay pattern and E max of breast masses were highly reproducible. The COP had better diagnostic ability than E max , suggesting that COP may be a more reliable parameter for solid breast mass evaluation. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. An Evaluation of the Performance Diagnostic Checklist-Human Services to Assess an Employee Performance Problem in a Center-Based Autism Treatment Facility

    Science.gov (United States)

    Ditzian, Kyle; Wilder, David A.; King, Allison; Tanz, Jeanine

    2015-01-01

    The Performance Diagnostic Checklist-Human Services (PDC-HS) is an informant-based tool designed to assess the environmental variables that contribute to poor employee performance in human services settings. We administered the PDC-HS to 3 supervisors to assess the variables that contributed to poor performance by 4 staff members when securing…

  4. The Interobserver Variability and Diagnostic Performance of 3-Dimensional Breast Ultrasound

    International Nuclear Information System (INIS)

    Lyou, Chae Yeon; Kim, Sun Mi; Jang, Mi Jung; Kim, Sung Won; Kang, Eun Young; Park, So Yeon; Moon, Woo Kyung

    2011-01-01

    We wanted to evaluate the interobserver variability and diagnostic performance of 3-dimensional (3D) breast ultrasound (US) as compared with that of 2- dimensional (2D) US. We included 150 patients who received US-guided core biopsy and 3D US between June 2009 and April 2010. Three breast imaging radiologists analyzed the 2D and 3D US images using the Breast Imaging Reporting and Data System (BI-RADS) lexicon. The intra-observer agreement and inter-observer agreement were calculated. The sensitivity and specificity of 2D and 3D US were evaluated. The intra-observer agreement between 2D and 3D US was mostly slight or fair agreement. However, in terms of the final category, there was substantial agreement for all three radiologists. The inter-observer agreement of 3D US was similar to that of 2D US (moderate agreement for shape, orientation, circumscribed margin and boundary: fair agreement for indistinct margin, angular margin, microlobulated margin, echo pattern and final category). The sensitivity of 3D US for breast cancer was higher than that of 2D US for two radiologists (2D vs. 3D for reader 2: 55.8% vs. 61.5%, 2D vs. 3D for reader 3: 59.6% vs. 63.5%), and the specificity of 3D US was lower than that of 2D US for all the readers (2D vs. 3D for reader 1: 90.8% vs. 86.7%, 2D vs. 3D for reader 2: 90.8% vs. 87.8%, 2D vs. 3D for reader 3: 94.9% vs. 90.8%), but the difference was not significant (p ≥ 0.05). The interobserver variability and diagnostic performance of 3D breast US were similar to those of 2D US

  5. Diagnostic performance of procalcitonin for hospitalised children with acute pyelonephritis presenting to the paediatric emergency department.

    Science.gov (United States)

    Chen, Shan-Ming; Chang, Hung-Ming; Hung, Tung-Wei; Chao, Yu-Hua; Tsai, Jeng-Dau; Lue, Ko-Huang; Sheu, Ji-Nan

    2013-05-01

    Urinary tract infection (UTI) is a common bacterial infection in children that can result in permanent renal damage. This study prospectively assessed the diagnostic performance of procalcitonin (PCT) for predicting acute pyelonephritis (APN) among children with febrile UTI presenting to the paediatric emergency department (ED). Children aged ≤10 years with febrile UTI admitted to hospital from the paediatric ED were prospectively studied. Blood PCT, C reactive protein (CRP) and white blood cell (WBC) count were measured in the ED. Sensitivity, specificity, predictive values, multilevel likelihood ratios, receiver operating characteristic (ROC) curve analysis and multivariate logistic regression were used to assess quantitative variables for diagnosing APN. The 136 enrolled patients (56 boys and 80 girls; age range 1 month to 10 years) were divided into APN (n=87) and lower UTI (n=49) groups according to (99m)Tc-dimercaptosuccinic acid scan results. The cut-off value for maximum diagnostic performance of PCT was 1.3 ng/ml (sensitivity 86.2%, specificity 89.8%). By multivariate regression analysis, only PCT and CRP were retained as significant predictors of APN. Comparing ROC curves, PCT had a significantly greater area under the curve than CRP, WBC count and fever for differentiating between APN and lower UTI. PCT has better sensitivity and specificity than CRP and WBC count for distinguishing between APN and lower UTI. PCT is a valuable marker for predicting APN in children with febrile UTI. It may be considered in the initial investigation and therapeutic strategies for children presenting to the ED.

  6. SU-F-E-01: Pitfalls: Reliability and Performance of Diagnostic X-Sources

    Energy Technology Data Exchange (ETDEWEB)

    Behling, R [Philips Medical Systems DMC GmbHHamburg (United States)

    2016-06-15

    Purpose: Performance and reliability of medical X-ray tubes for imaging are crucial from an ethical, clinical and economic perspective. This lecture will deliver insight into the aspects to consider during the decision making process to invest in X-ray imaging equipment. Outdated metric still hampers realistic product comparison. It is time to change this and to comply with latest standards, which consider current technology. Failure modes and ways to avoid down-time of the equipment shall be discussed. In view of the increasing number of interventional procedures and the hazards associated with ionizing radiation, toxic contrast agents, and the combination thereof, the aspect of system reliability is of paramount importance. Methods: A comprehensive picture of trends for different modalities (CT, angiography, general radiology) has been drawn and led to the development of novel X-ray tube technology. Results: Recent X-ray tubes feature enhanced reliability and unprecedented performance. Relevant metrics for product comparison still have to be implemented in practice. Conclusion: The speed of scientific and industrial development of new diagnostic and therapeutic X-ray sources remains tremendous. Still, users suffer from gaps between desire and reality in day-to-day diagnostic routine. X-ray sources are still limiting cutting-edge medical procedures. Side-effects of wear and tear, limitations of the clinical work flow, costs, the characteristics of the X-ray spectrum and others topics need to be further addressed. New applications and modalities, like detection-based color-resolved X-ray and phase-contrast / dark-field imaging will impact the course of new developments of X-ray sources. The author is employee of Royal Philips.

  7. Clinical performance of dual-source computerized tomography (DSCT) in primary diagnostics of coronary heart diseases

    International Nuclear Information System (INIS)

    Brunner, H.; Froehner, S.; Wagner, M.; Schmitt, R.; Brunn, J.; Gietzen, F.H.; Kerber, S.

    2008-01-01

    Dual-source-CT-technology (DSCT) improves temporal resolution of cardiac computed tomography to 83 ms per heart-phase. In this study, the clinical performance of this new method is evaluated. Materials and Methods: In fifty patients (33 male, 17 female; age 50±13 years) with suspected coronary heart disease, CT angiography (slice thickness 0,75 mm, contrast-agent 60-80 ml iomeprol) was performed with a Somatom Definition scanner. Based on the coronary 15-segment-model of the AHA, scores for image quality and lumen reduction were established to enable the observer, to give recommendations for further therapy. Results: Out of 750 possible AHA-segments, 655 were depicted (87,3%). 591 segments (90,2%) were assessed without any limitation of quality, 49 (7,5%) segments showed moderate, and 15 (2,3%) segments severe limitation in image quality. 508 (77,6%) segments were without pathological findings, 92 (14,0%) segments had minimal atherosclerotic lesions, 42 (6,4%) segments suffered from stenoses with lumen reduction less than 70%, and 13 (2,0%) showed significant stenoses of more than 70%. In 31 patients (62%), coronary heart disease was ruled out by CT angiography without any need for further non-invasive or invasive diagnostics. 8 patients (16%) underwent stress-testing for ischemia. In 11 (22%) patients coronary angiography was recommended, and DSCT findings were confirmed in 10 cases. Only one LCx stenosis was overestimated in DSCT. Conclusion: Contrast-enhanced DSCT is a powerful tool in diagnosis of coronary heart disease. 98% of coronary segments could be assessed in diagnostic quality, and at least 90% of haemodynamically significant coronary stenoses were detected. (orig.)

  8. Diagnostic performance of 3D standing CT imaging for detection of knee osteoarthritis features.

    Science.gov (United States)

    Segal, Neil A; Nevitt, Michael C; Lynch, John A; Niu, Jingbo; Torner, James C; Guermazi, Ali

    2015-07-01

    To determine the diagnostic performance of standing computerized tomography (SCT) of the knee for osteophytes and subchondral cysts compared with fixed-flexion radiography, using MRI as the reference standard. Twenty participants were recruited from the Multicenter Osteoarthritis Study. Participants' knees were imaged with SCT while standing in a knee-positioning frame, and with postero-anterior fixed-flexion radiography and 1T MRI. Medial and lateral marginal osteophytes and subchondral cysts were scored on bilateral radiographs and coronal SCT images using the OARSI grading system and on coronal MRI using Whole Organ MRI Scoring. Imaging modalities were read separately with images in random order. Sensitivity, specificity and accuracy for the detection of lesions were calculated and differences between modalities were tested using McNemar's test. Participants' mean age was 66.8 years, body mass index was 29.6 kg/m(2) and 50% were women. Of the 160 surfaces (medial and lateral femur and tibia for 40 knees), MRI revealed 84 osteophytes and 10 subchondral cysts. In comparison with osteophytes and subchondral cysts detected by MRI, SCT was significantly more sensitive (93 and 100%; p osteophytes) than plain radiographs (sensitivity 60 and 10% and accuracy 79 and 94%, respectively). For osteophytes, differences in sensitivity and accuracy were greatest at the medial femur (p = 0.002). In comparison with MRI, SCT imaging was more sensitive and accurate for detection of osteophytes and subchondral cysts than conventional fixed-flexion radiography. Additional study is warranted to assess diagnostic performance of SCT measures of joint space width, progression of OA features and the patellofemoral joint.

  9. SU-F-E-01: Pitfalls: Reliability and Performance of Diagnostic X-Sources

    International Nuclear Information System (INIS)

    Behling, R

    2016-01-01

    Purpose: Performance and reliability of medical X-ray tubes for imaging are crucial from an ethical, clinical and economic perspective. This lecture will deliver insight into the aspects to consider during the decision making process to invest in X-ray imaging equipment. Outdated metric still hampers realistic product comparison. It is time to change this and to comply with latest standards, which consider current technology. Failure modes and ways to avoid down-time of the equipment shall be discussed. In view of the increasing number of interventional procedures and the hazards associated with ionizing radiation, toxic contrast agents, and the combination thereof, the aspect of system reliability is of paramount importance. Methods: A comprehensive picture of trends for different modalities (CT, angiography, general radiology) has been drawn and led to the development of novel X-ray tube technology. Results: Recent X-ray tubes feature enhanced reliability and unprecedented performance. Relevant metrics for product comparison still have to be implemented in practice. Conclusion: The speed of scientific and industrial development of new diagnostic and therapeutic X-ray sources remains tremendous. Still, users suffer from gaps between desire and reality in day-to-day diagnostic routine. X-ray sources are still limiting cutting-edge medical procedures. Side-effects of wear and tear, limitations of the clinical work flow, costs, the characteristics of the X-ray spectrum and others topics need to be further addressed. New applications and modalities, like detection-based color-resolved X-ray and phase-contrast / dark-field imaging will impact the course of new developments of X-ray sources. The author is employee of Royal Philips

  10. TH-F-209-01: Pitfalls: Reliability and Performance of Diagnostic X-Ray Sources

    International Nuclear Information System (INIS)

    Behling, R.

    2016-01-01

    Purpose: Performance and reliability of medical X-ray tubes for imaging are crucial from an ethical, clinical and economic perspective. This lecture will deliver insight into the aspects to consider during the decision making process to invest in X-ray imaging equipment. Outdated metric still hampers realistic product comparison. It is time to change this and to comply with latest standards, which consider current technology. Failure modes and ways to avoid down-time of the equipment shall be discussed. In view of the increasing number of interventional procedures and the hazards associated with ionizing radiation, toxic contrast agents, and the combination thereof, the aspect of system reliability is of paramount importance. Methods: A comprehensive picture of trends for different modalities (CT, angiography, general radiology) has been drawn and led to the development of novel X-ray tube technology. Results: Recent X-ray tubes feature enhanced reliability and unprecedented performance. Relevant metrics for product comparison still have to be implemented in practice. Conclusion: The speed of scientific and industrial development of new diagnostic and therapeutic X-ray sources remains tremendous. Still, users suffer from gaps between desire and reality in day-to-day diagnostic routine. X-ray sources are still limiting cutting-edge medical procedures. Side-effects of wear and tear, limitations of the clinical work flow, costs, the characteristics of the X-ray spectrum and others topics need to be further addressed. New applications and modalities, like detection-based color-resolved X-ray and phase-contrast / dark-field imaging will impact the course of new developments of X-ray sources. Learning Objectives: Understand the basic requirements on medical diagnostic X-ray sources per modality Learn to select the optimal equipment employing state-of-the-art metric Know causes of failures, depending on the way X-ray sources are operated Understand methods to remediate

  11. TH-F-209-00: Pitfalls: Reliability and Performance of Diagnostic X-Ray Sources

    International Nuclear Information System (INIS)

    2016-01-01

    Purpose: Performance and reliability of medical X-ray tubes for imaging are crucial from an ethical, clinical and economic perspective. This lecture will deliver insight into the aspects to consider during the decision making process to invest in X-ray imaging equipment. Outdated metric still hampers realistic product comparison. It is time to change this and to comply with latest standards, which consider current technology. Failure modes and ways to avoid down-time of the equipment shall be discussed. In view of the increasing number of interventional procedures and the hazards associated with ionizing radiation, toxic contrast agents, and the combination thereof, the aspect of system reliability is of paramount importance. Methods: A comprehensive picture of trends for different modalities (CT, angiography, general radiology) has been drawn and led to the development of novel X-ray tube technology. Results: Recent X-ray tubes feature enhanced reliability and unprecedented performance. Relevant metrics for product comparison still have to be implemented in practice. Conclusion: The speed of scientific and industrial development of new diagnostic and therapeutic X-ray sources remains tremendous. Still, users suffer from gaps between desire and reality in day-to-day diagnostic routine. X-ray sources are still limiting cutting-edge medical procedures. Side-effects of wear and tear, limitations of the clinical work flow, costs, the characteristics of the X-ray spectrum and others topics need to be further addressed. New applications and modalities, like detection-based color-resolved X-ray and phase-contrast / dark-field imaging will impact the course of new developments of X-ray sources. Learning Objectives: Understand the basic requirements on medical diagnostic X-ray sources per modality Learn to select the optimal equipment employing state-of-the-art metric Know causes of failures, depending on the way X-ray sources are operated Understand methods to remediate

  12. TH-F-209-01: Pitfalls: Reliability and Performance of Diagnostic X-Ray Sources

    Energy Technology Data Exchange (ETDEWEB)

    Behling, R. [Philips Medical Systems DMC GmbH (United States)

    2016-06-15

    Purpose: Performance and reliability of medical X-ray tubes for imaging are crucial from an ethical, clinical and economic perspective. This lecture will deliver insight into the aspects to consider during the decision making process to invest in X-ray imaging equipment. Outdated metric still hampers realistic product comparison. It is time to change this and to comply with latest standards, which consider current technology. Failure modes and ways to avoid down-time of the equipment shall be discussed. In view of the increasing number of interventional procedures and the hazards associated with ionizing radiation, toxic contrast agents, and the combination thereof, the aspect of system reliability is of paramount importance. Methods: A comprehensive picture of trends for different modalities (CT, angiography, general radiology) has been drawn and led to the development of novel X-ray tube technology. Results: Recent X-ray tubes feature enhanced reliability and unprecedented performance. Relevant metrics for product comparison still have to be implemented in practice. Conclusion: The speed of scientific and industrial development of new diagnostic and therapeutic X-ray sources remains tremendous. Still, users suffer from gaps between desire and reality in day-to-day diagnostic routine. X-ray sources are still limiting cutting-edge medical procedures. Side-effects of wear and tear, limitations of the clinical work flow, costs, the characteristics of the X-ray spectrum and others topics need to be further addressed. New applications and modalities, like detection-based color-resolved X-ray and phase-contrast / dark-field imaging will impact the course of new developments of X-ray sources. Learning Objectives: Understand the basic requirements on medical diagnostic X-ray sources per modality Learn to select the optimal equipment employing state-of-the-art metric Know causes of failures, depending on the way X-ray sources are operated Understand methods to remediate

  13. TH-F-209-00: Pitfalls: Reliability and Performance of Diagnostic X-Ray Sources

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2016-06-15

    Purpose: Performance and reliability of medical X-ray tubes for imaging are crucial from an ethical, clinical and economic perspective. This lecture will deliver insight into the aspects to consider during the decision making process to invest in X-ray imaging equipment. Outdated metric still hampers realistic product comparison. It is time to change this and to comply with latest standards, which consider current technology. Failure modes and ways to avoid down-time of the equipment shall be discussed. In view of the increasing number of interventional procedures and the hazards associated with ionizing radiation, toxic contrast agents, and the combination thereof, the aspect of system reliability is of paramount importance. Methods: A comprehensive picture of trends for different modalities (CT, angiography, general radiology) has been drawn and led to the development of novel X-ray tube technology. Results: Recent X-ray tubes feature enhanced reliability and unprecedented performance. Relevant metrics for product comparison still have to be implemented in practice. Conclusion: The speed of scientific and industrial development of new diagnostic and therapeutic X-ray sources remains tremendous. Still, users suffer from gaps between desire and reality in day-to-day diagnostic routine. X-ray sources are still limiting cutting-edge medical procedures. Side-effects of wear and tear, limitations of the clinical work flow, costs, the characteristics of the X-ray spectrum and others topics need to be further addressed. New applications and modalities, like detection-based color-resolved X-ray and phase-contrast / dark-field imaging will impact the course of new developments of X-ray sources. Learning Objectives: Understand the basic requirements on medical diagnostic X-ray sources per modality Learn to select the optimal equipment employing state-of-the-art metric Know causes of failures, depending on the way X-ray sources are operated Understand methods to remediate

  14. Diagnostic Performance of Magnifying Endoscopy for Helicobacter pylori Infection: A Meta-Analysis.

    Directory of Open Access Journals (Sweden)

    Qingqing Qi

    Full Text Available Diagnosis of Helicobacter pylori (H. pylori infection using magnifying endoscopy offers advantages over conventional invasive and noninvasive tests.This meta-analysis aimed to assess the diagnostic performance of magnifying endoscopy in the prediction of H. pylori infection.A literature search of the PubMed, Medline, EMBASE, Science Direct and the Cochrane Library databases was performed. A random-effects model was used to calculate the diagnostic efficiency of magnifying endoscopy for H. pylori infection. A summary receiver operator characteristic curve was plotted, and the area under the curve (AUC was calculated.A total of 18 studies involving 1897 patients were included. The pooled sensitivity and specificity of magnifying endoscopy to predict H. pylori infection were 0.89 [95% confidence interval (CI 0.87-0.91] and 0.82 (95%CI 0.79-0.85, respectively, with an AUC of 0.9461. When targeting the gastric antrum, the pooled sensitivity and specificity were 0.82 (95%CI 0.78-0.86 and 0.72 (95%CI 0.66-0.78, respectively. When targeting the gastric corpus, the pooled sensitivity and specificity were 0.92 (95%CI 0.90-0.94 and 0.86 (95%CI 0.82-0.88, respectively. The pooled sensitivity and specificity using magnifying white light endoscopy were 0.90 (95%CI 0.87-0.91 and 0.81 (95%CI 0.77-0.84, respectively. The pooled sensitivity and specificity using magnifying chromoendoscopy were 0.87 (95%CI 0.83-0.91 and 0.85 (95%CI 0.80-0.88, respectively. The "pit plus vascular pattern" classification in the gastric corpus observed by magnifying endoscopy was able to accurately predict the status of H. pylori infection, as indicated by a pooled sensitivity and specificity of 0.96 (95%CI 0.94-0.97 and 0.91 (95%CI 0.87-0.93, respectively, with an AUC of 0.9872.Magnifying endoscopy was able to accurately predict the status of H. pylori infection, either in magnifying white light endoscopy or magnifying chromoendoscopy mode. The "pit plus vascular pattern

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

    International Nuclear Information System (INIS)

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

    2016-01-01

    Whole-body 18 F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) is the standard of care for lymphoma. Simultaneous PET/MRI (magnetic resonance imaging) is a promising new modality that combines the metabolic information of PET with superior soft-tissue resolution and functional imaging capabilities of MRI while decreasing radiation dose. There is limited information on the clinical performance of PET/MRI in the pediatric setting. This study evaluated the feasibility, dosimetry, and qualitative and quantitative diagnostic performance of simultaneous whole-body FDG-PET/MRI in children with lymphoma compared to PET/CT. Children with lymphoma undergoing standard of care FDG-PET/CT were prospectively recruited for PET/MRI performed immediately after the PET/CT. Images were evaluated for quality, lesion detection and anatomical localization of FDG uptake. Maximum and mean standardized uptake values (SUV max/mean ) of normal organs and SUV max of the most FDG-avid lesions were measured for PET/MRI and PET/CT. Estimation of radiation exposure was calculated using specific age-related factors. Nine PET/MRI scans were performed in eight patients (mean age: 15.3 years). The mean time interval between PET/CT and PET/MRI was 51 ± 10 min. Both the PET/CT and PET/MRI exams had good image quality and alignment with complete (9/9) concordance in response assessment. The SUVs from PET/MRI and PET/CT were highly correlated for normal organs (SUV mean r 2 : 0.88, P<0.0001) and very highly for FDG-avid lesions (SUV max r 2 : 0.94, P=0.0002). PET/MRI demonstrated an average percent radiation exposure reduction of 39% ± 13% compared with PET/CT. Simultaneous whole-body PET/MRI is clinically feasible in pediatric lymphoma. PET/MRI performance is comparable to PET/CT for lesion detection and SUV measurements. Replacement of PET/CT with PET/MRI can significantly decrease radiation dose from diagnostic imaging in children. (orig.)

  16. Digibaro pressure instrument onboard the Phoenix Lander

    Science.gov (United States)

    Harri, A.-M.; Polkko, J.; Kahanpää, H. H.; Schmidt, W.; Genzer, M. M.; Haukka, H.; Savijarv1, H.; Kauhanen, J.

    2009-04-01

    The Phoenix Lander landed successfully on the Martian northern polar region. The mission is part of the National Aeronautics and Space Administration's (NASA's) Scout program. Pressure observations onboard the Phoenix lander were performed by an FMI (Finnish Meteorological Institute) instrument, based on a silicon diaphragm sensor head manufactured by Vaisala Inc., combined with MDA data processing electronics. The pressure instrument performed successfully throughout the Phoenix mission. The pressure instrument had 3 pressure sensor heads. One of these was the primary sensor head and the other two were used for monitoring the condition of the primary sensor head during the mission. During the mission the primary sensor was read with a sampling interval of 2 s and the other two were read less frequently as a check of instrument health. The pressure sensor system had a real-time data-processing and calibration algorithm that allowed the removal of temperature dependent calibration effects. In the same manner as the temperature sensor, a total of 256 data records (8.53 min) were buffered and they could either be stored at full resolution, or processed to provide mean, standard deviation, maximum and minimum values for storage on the Phoenix Lander's Meteorological (MET) unit.The time constant was approximately 3s due to locational constraints and dust filtering requirements. Using algorithms compensating for the time constant effect the temporal resolution was good enough to detect pressure drops associated with the passage of nearby dust devils.

  17. Temporal diagnostic analysis of the SWAT model to detect dominant periods of poor model performance

    Science.gov (United States)

    Guse, Björn; Reusser, Dominik E.; Fohrer, Nicola

    2013-04-01

    Hydrological models generally include thresholds and non-linearities, such as snow-rain-temperature thresholds, non-linear reservoirs, infiltration thresholds and the like. When relating observed variables to modelling results, formal methods often calculate performance metrics over long periods, reporting model performance with only few numbers. Such approaches are not well suited to compare dominating processes between reality and model and to better understand when thresholds and non-linearities are driving model results. We present a combination of two temporally resolved model diagnostic tools to answer when a model is performing (not so) well and what the dominant processes are during these periods. We look at the temporal dynamics of parameter sensitivities and model performance to answer this question. For this, the eco-hydrological SWAT model is applied in the Treene lowland catchment in Northern Germany. As a first step, temporal dynamics of parameter sensitivities are analyzed using the Fourier Amplitude Sensitivity test (FAST). The sensitivities of the eight model parameters investigated show strong temporal variations. High sensitivities were detected for two groundwater (GW_DELAY, ALPHA_BF) and one evaporation parameters (ESCO) most of the time. The periods of high parameter sensitivity can be related to different phases of the hydrograph with dominances of the groundwater parameters in the recession phases and of ESCO in baseflow and resaturation periods. Surface runoff parameters show high parameter sensitivities in phases of a precipitation event in combination with high soil water contents. The dominant parameters give indication for the controlling processes during a given period for the hydrological catchment. The second step included the temporal analysis of model performance. For each time step, model performance was characterized with a "finger print" consisting of a large set of performance measures. These finger prints were clustered into

  18. Substantia nigra fractional anisotropy is not a diagnostic biomarker of Parkinson's disease: A diagnostic performance study and meta-analysis

    Energy Technology Data Exchange (ETDEWEB)

    Hirata, Fabiana C.C.; Vieira, Gilson; Lucato, Leandro T.; Leite, Claudia C.; Pastorello, Bruno F.; Otaduy, Maria C.G.; Chaim, Khallil T.; Campanholo, Kenia R. [University of Sao Paulo, LIM-44, Department of Radiology, Sao Paulo, SP (Brazil); Sato, Joao R. [University of Sao Paulo, LIM-44, Department of Radiology, Sao Paulo, SP (Brazil); Universidade Federal do ABC, Center of Mathematics, Computation and Cognition, Santo Andre (Brazil); Bor-Seng-Shu, Edson; Novaes, Natalia P. [Hospital Israelita Albert Einstein, Sao Paulo (Brazil); University of Sao Paulo, Department of Neurology, Sao Paulo (Brazil); Magalhaes Melo, Luciano; Goncalves, Marcia R.; Reis Barbosa, Egberto [University of Sao Paulo, Department of Neurology, Sao Paulo (Brazil); Pereira do Nascimento, Felipe Barjud; Amaro, Edson [University of Sao Paulo, LIM-44, Department of Radiology, Sao Paulo, SP (Brazil); Hospital Israelita Albert Einstein, Sao Paulo (Brazil); Jacobsen Teixeira, Manoel [University of Sao Paulo, Department of Neurosurgery, Sao Paulo (Brazil); Cardoso, Ellison Fernando [University of Sao Paulo, LIM-44, Department of Radiology, Sao Paulo, SP (Brazil); Hospital Israelita Albert Einstein, Sao Paulo (Brazil); Institute of Mathematics and Statistics University of Sao Paulo (IME-USP), Sao Paulo (Brazil)

    2017-06-15

    Our goal was to estimate the diagnostic accuracy of substantia nigra fractional anisotropy (SN-FA) for Parkinson's disease (PD) diagnosis in a sample similar to the clinical setting, including patients with essential tremor (ET) and healthy controls (HC). We also performed a systematic review and meta-analysis to estimate mean change in SN-FA induced by PD and its diagnostic accuracy. Our sample consisted of 135 subjects: 72 PD, 21 ET and 42 HC. To address inter-scanner variability, two 3.0-T MRI scans were performed. MRI results of this sample were pooled into a meta-analysis that included 1,432 subjects (806 PD and 626 HC). A bivariate model was used to evaluate diagnostic accuracy measures. In our sample, we did not observe a significant effect of disease on SN-FA and it was uninformative for diagnosis. The results of the meta-analysis estimated a 0.03 decrease in mean SN-FA in PD relative to HC (CI: 0.01-0.05). However, the discriminatory capability of SN-FA to diagnose PD was low: pooled sensitivity and specificity were 72 % (CI: 68-75) and 63 % (CI: 58-70), respectively. There was high heterogeneity between studies (I{sup 2} = 91.9 %). SN-FA cannot be used as an isolated measure to diagnose PD. (orig.)

  19. MOBS - A modular on-board switching system

    Science.gov (United States)

    Berner, W.; Grassmann, W.; Piontek, M.

    The authors describe a multibeam satellite system that is designed for business services and for communications at a high bit rate. The repeater is regenerative with a modular onboard switching system. It acts not only as baseband switch but also as the central node of the network, performing network control and protocol evaluation. The hardware is based on a modular bus/memory architecture with associated processors.

  20. Diagnostic performance of tumor markers AFP and PIVKA-II in Chinese hepatocellular carcinoma patients.

    Science.gov (United States)

    Huang, Shujing; Jiang, Feifei; Wang, Ying; Yu, Yanhua; Ren, Siqian; Wang, Xiaowei; Yin, Peng; Lou, Jinli

    2017-06-01

    Alpha-fetoprotein is an effective biomarker as an aid in hepatocellular carcinoma detection in many countries. However, alpha-fetoprotein has its limitations, especially in early hepatocellular carcinoma diagnosis. Protein induced by vitamin K absence or antagonist-II is another biomarker that is used for hepatocellular carcinoma detection. The aim of this study is to compare the diagnostic performance of alpha-fetoprotein and protein induced by vitamin K absence or antagonist-II alone and in combination to explore improving biomarker performance as an aid in early hepatocellular carcinoma detection. In this study a total of 582 serum samples including 132 hepatocellular carcinoma patients, 250 non-hepatocellular carcinoma patients, and 200 healthy volunteers were collected. Alpha-fetoprotein and protein induced by vitamin K absence or antagonist-II levels were measured by both chemiluminescent enzyme immunoassay on LUMIPULSE platform and by chemiluminescent microparticle immunoassay on ARCHITECT platform. Receiver operation characteristic curve analyses were performed for each biomarker and in combination. The results showed that Alpha-fetoprotein and protein induced by vitamin K absence or antagonist-II in combination have shown higher area under the curve compared to alpha-fetoprotein alone for diagnosis in whole patients (0.906 vs 0.870) in hepatocellular carcinoma early-stage patients (0.809 vs 0.77) and in hepatitis B virus-related hepatocellular carcinoma patients (0.851 vs 0.788) with ARCHITECT platform. Protein induced by vitamin K absence or antagonist-II showed higher area under the curve than alpha-fetoprotein for diagnosis of hepatitis B virus-related hepatocellular carcinoma patients (0.901 vs 0.788).We conclude that Combining alpha-fetoprotein and protein induced by vitamin K absence or antagonist-II may improve the diagnostic value for early detection of hepatocellular carcinoma. Protein induced by vitamin K absence or antagonist-II performs better

  1. Optimization of an on-board imaging system for extremely rapid radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Cherry Kemmerling, Erica M.; Wu, Meng, E-mail: mengwu@stanford.edu; Yang, He; Fahrig, Rebecca [Department of Radiology, Stanford University, Stanford, California 94305 (United States); Maxim, Peter G.; Loo, Billy W. [Department of Radiation Oncology, Stanford University, Stanford, California 94305 and Stanford Cancer Institute, Stanford University School of Medicine, Stanford, California 94305 (United States)

    2015-11-15

    Purpose: Next-generation extremely rapid radiation therapy systems could mitigate the need for motion management, improve patient comfort during the treatment, and increase patient throughput for cost effectiveness. Such systems require an on-board imaging system that is competitively priced, fast, and of sufficiently high quality to allow good registration between the image taken on the day of treatment and the image taken the day of treatment planning. In this study, three different detectors for a custom on-board CT system were investigated to select the best design for integration with an extremely rapid radiation therapy system. Methods: Three different CT detectors are proposed: low-resolution (all 4 × 4 mm pixels), medium-resolution (a combination of 4 × 4 mm pixels and 2 × 2 mm pixels), and high-resolution (all 1 × 1 mm pixels). An in-house program was used to generate projection images of a numerical anthropomorphic phantom and to reconstruct the projections into CT datasets, henceforth called “realistic” images. Scatter was calculated using a separate Monte Carlo simulation, and the model included an antiscatter grid and bowtie filter. Diagnostic-quality images of the phantom were generated to represent the patient scan at the time of treatment planning. Commercial deformable registration software was used to register the diagnostic-quality scan to images produced by the various on-board detector configurations. The deformation fields were compared against a “gold standard” deformation field generated by registering initial and deformed images of the numerical phantoms that were used to make the diagnostic and treatment-day images. Registrations of on-board imaging system data were judged by the amount their deformation fields differed from the corresponding gold standard deformation fields—the smaller the difference, the better the system. To evaluate the registrations, the pointwise distance between gold standard and realistic registration

  2. Optimization of an on-board imaging system for extremely rapid radiation therapy

    International Nuclear Information System (INIS)

    Cherry Kemmerling, Erica M.; Wu, Meng; Yang, He; Fahrig, Rebecca; Maxim, Peter G.; Loo, Billy W.

    2015-01-01

    Purpose: Next-generation extremely rapid radiation therapy systems could mitigate the need for motion management, improve patient comfort during the treatment, and increase patient throughput for cost effectiveness. Such systems require an on-board imaging system that is competitively priced, fast, and of sufficiently high quality to allow good registration between the image taken on the day of treatment and the image taken the day of treatment planning. In this study, three different detectors for a custom on-board CT system were investigated to select the best design for integration with an extremely rapid radiation therapy system. Methods: Three different CT detectors are proposed: low-resolution (all 4 × 4 mm pixels), medium-resolution (a combination of 4 × 4 mm pixels and 2 × 2 mm pixels), and high-resolution (all 1 × 1 mm pixels). An in-house program was used to generate projection images of a numerical anthropomorphic phantom and to reconstruct the projections into CT datasets, henceforth called “realistic” images. Scatter was calculated using a separate Monte Carlo simulation, and the model included an antiscatter grid and bowtie filter. Diagnostic-quality images of the phantom were generated to represent the patient scan at the time of treatment planning. Commercial deformable registration software was used to register the diagnostic-quality scan to images produced by the various on-board detector configurations. The deformation fields were compared against a “gold standard” deformation field generated by registering initial and deformed images of the numerical phantoms that were used to make the diagnostic and treatment-day images. Registrations of on-board imaging system data were judged by the amount their deformation fields differed from the corresponding gold standard deformation fields—the smaller the difference, the better the system. To evaluate the registrations, the pointwise distance between gold standard and realistic registration

  3. Evaluating the Performance Diagnostic Checklist-Human Services to Assess Incorrect Error-Correction Procedures by Preschool Paraprofessionals

    Science.gov (United States)

    Bowe, Melissa; Sellers, Tyra P.

    2018-01-01

    The Performance Diagnostic Checklist-Human Services (PDC-HS) has been used to assess variables contributing to undesirable staff performance. In this study, three preschool teachers completed the PDC-HS to identify the factors contributing to four paraprofessionals' inaccurate implementation of error-correction procedures during discrete trial…

  4. Diagnostic performance of computed tomography coronary angiography (from the Prospective National Multicenter Multivendor EVASCAN Study).

    Science.gov (United States)

    Gueret, Pascal; Deux, Jean-François; Bonello, Laurent; Sarran, Anthony; Tron, Christophe; Christiaens, Luc; Dacher, Jean-Nicolas; Bertrand, David; Leborgne, Laurent; Renard, Cedric; Caussin, Christophe; Cluzel, Philippe; Helft, Gerard; Crochet, Dominique; Vernhet-Kovacsik, Hélène; Chabbert, Valérie; Ferrari, Emile; Gilard, Martine; Willoteaux, Serge; Furber, Alain; Barone-Rochette, Gilles; Jankowski, Adrien; Douek, Philippe; Mousseaux, Elie; Sirol, Marc; Niarra, Ralph; Chatellier, Gilles; Laissy, Jean-Pierre

    2013-02-15

    Computed tomographic coronary angiography (CTCA) has been proposed as a noninvasive test for significant coronary artery disease (CAD), but only limited data are available from prospective multicenter trials. The goal of this study was to establish the diagnostic accuracy of CTCA compared to coronary angiography (CA) in a large population of symptomatic patients with clinical indications for coronary imaging. This national, multicenter study was designed to prospectively evaluate stable patients able to undergo CTCA followed by conventional CA. Data from CTCA and CA were analyzed in a blinded fashion at central core laboratories. The main outcome was the evaluation of patient-, vessel-, and segment-based diagnostic performance of CTCA to detect or rule out significant CAD (≥50% luminal diameter reduction). Of 757 patients enrolled, 746 (mean age 61 ± 12 years, 71% men) were analyzed. They underwent CTCA followed by CA 1.7 ± 0.8 days later using a 64-detector scanner. The prevalence of significant CAD in native coronary vessels by CA was 54%. The rate of nonassessable segments by CTCA was 6%. In a patient-based analysis, sensitivity, specificity, positive and negative predictive values, and positive and negative likelihood ratios of CTCA were 91%, 50%, 68%, 83%, 1.82, and 0.18, respectively. The strongest predictors of false-negative results on CTCA were high estimated pretest probability of CAD (odds ratio [OR] 1.97, p <0.001), male gender (OR 1.5, p <0.002), diabetes (OR 1.5, p <0.0001), and age (OR 1.2, p <0.0001). In conclusion, in this large multicenter study, CTCA identified significant CAD with high sensitivity. However, in routine clinical practice, each patient should be individually evaluated, and the pretest probability of obstructive CAD should be taken into account when deciding which method, CTCA or CA, to use to diagnose its presence and severity. Copyright © 2013 Elsevier Inc. All rights reserved.

  5. Performance and Pain Tolerability of Current Diagnostic Allergy Skin Prick Test Devices.

    Science.gov (United States)

    Tversky, Jody R; Chelladurai, Yohalakshmi; McGready, John; Hamilton, Robert G

    2015-01-01

    Allergen skin prick testing remains an essential tool for diagnosing atopic disease and guiding treatment. Sensitivity needs to be defined for newly introduced devices. Our aim was to compare the performance of 10 current allergy skin prick test devices. Single- and multiheaded skin test devices (n = 10) were applied by a single operator in a prospective randomized manner. Histamine (1 and 6 mg/mL) and control diluent were introduced at 6 randomized locations onto the upper and lower arms of healthy subjects. Wheal and flare reactions were measured independently by 2 masked technicians. Twenty-four subjects provided consent, and 768 skin tests were placed. Mean wheal diameter among devices differed from 3.0 mm (ComforTen; Hollister-Stier, Spokane, Wash) to 6.8 mm (UniTest PC; Lincoln Diagnostics, Decatur, Ill) using 1 mg/mL histamine (P Diagnostics, Decatur, Ill; and Sharp-Test; Panatrex, Placentia, Calif) using 6 mg/mL histamine (P pain score of less than 4 on a 10-point visual analog scale. Pain scores were higher among women, but this did not reach statistical significance. The Multi-Test PC and the UniTest PC had the lowest pain scores compared with the other devices. All 10 skin prick test devices displayed good analytical sensitivity and specificity; however, 3 mm cannot arbitrarily be used as a positive threshold. The use of histamine at 1 mg/mL is unacceptable for certain devices but may be preferable for the most sensitive devices. On average, there was no pain score difference between multiheaded and single-head devices. Copyright © 2015 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  6. Diagnostic performance of line-immunoassay based algorithms for incident HIV-1 infection

    Directory of Open Access Journals (Sweden)

    Schüpbach Jörg

    2012-04-01

    Full Text Available Abstract Background Serologic testing algorithms for recent HIV seroconversion (STARHS provide important information for HIV surveillance. We have previously demonstrated that a patient's antibody reaction pattern in a confirmatory line immunoassay (INNO-LIA™ HIV I/II Score provides information on the duration of infection, which is unaffected by clinical, immunological and viral variables. In this report we have set out to determine the diagnostic performance of Inno-Lia algorithms for identifying incident infections in patients with known duration of infection and evaluated the algorithms in annual cohorts of HIV notifications. Methods Diagnostic sensitivity was determined in 527 treatment-naive patients infected for up to 12 months. Specificity was determined in 740 patients infected for longer than 12 months. Plasma was tested by Inno-Lia and classified as either incident ( Results The 10 best algorithms had a mean raw sensitivity of 59.4% and a mean specificity of 95.1%. Adjustment for overrepresentation of patients in the first quarter year of infection further reduced the sensitivity. In the preferred model, the mean adjusted sensitivity was 37.4%. Application of the 10 best algorithms to four annual cohorts of HIV-1 notifications totalling 2'595 patients yielded a mean IIR of 0.35 in 2005/6 (baseline and of 0.45, 0.42 and 0.35 in 2008, 2009 and 2010, respectively. The increase between baseline and 2008 and the ensuing decreases were highly significant. Other adjustment models yielded different absolute IIR, although the relative changes between the cohorts were identical for all models. Conclusions The method can be used for comparing IIR in annual cohorts of HIV notifications. The use of several different algorithms in combination, each with its own sensitivity and specificity to detect incident infection, is advisable as this reduces the impact of individual imperfections stemming primarily from relatively low sensitivities and

  7. Diagnostic performance of an acoustic-based system for coronary artery disease risk stratification.

    Science.gov (United States)

    Winther, Simon; Nissen, Louise; Schmidt, Samuel Emil; Westra, Jelmer Sybren; Rasmussen, Laust Dupont; Knudsen, Lars Lyhne; Madsen, Lene Helleskov; Kirk Johansen, Jane; Larsen, Bjarke Skogstad; Struijk, Johannes Jan; Frost, Lars; Holm, Niels Ramsing; Christiansen, Evald Høj; Botker, Hans Erik; Bøttcher, Morten

    2017-11-09

    Diagnosing coronary artery disease (CAD) continues to require substantial healthcare resources. Acoustic analysis of transcutaneous heart sounds of cardiac movement and intracoronary turbulence due to obstructive coronary disease could potentially change this. The aim of this study was thus to test the diagnostic accuracy of a new portable acoustic device for detection of CAD. We included 1675 patients consecutively with low to intermediate likelihood of CAD who had been referred for cardiac CT angiography. If significant obstruction was suspected in any coronary segment, patients were referred to invasive angiography and fractional flow reserve (FFR) assessment. Heart sound analysis was performed in all patients. A predefined acoustic CAD-score algorithm was evaluated; subsequently, we developed and validated an updated CAD-score algorithm that included both acoustic features and clinical risk factors. Low risk is indicated by a CAD-score value ≤20. Haemodynamically significant CAD assessed from FFR was present in 145 (10.0%) patients. In the entire cohort, the predefined CAD-score had a sensitivity of 63% and a specificity of 44%. In total, 50% had an updated CAD-score value ≤20. At this cut-off, sensitivity was 81% (95% CI 73% to 87%), specificity 53% (95% CI 50% to 56%), positive predictive value 16% (95% CI 13% to 18%) and negative predictive value 96% (95% CI 95% to 98%) for diagnosing haemodynamically significant CAD. Sound-based detection of CAD enables risk stratification superior to clinical risk scores. With a negative predictive value of 96%, this new acoustic rule-out system could potentially supplement clinical assessment to guide decisions on the need for further diagnostic investigation. ClinicalTrials.gov identifier NCT02264717; Results. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  8. Diagnostic mirrors for ITER: A material choice and the impact of erosion and deposition on their performance

    International Nuclear Information System (INIS)

    Litnovsky, A.; Wienhold, P.; Philipps, V.; Sergienko, G.; Schmitz, O.; Kirschner, A.; Kreter, A.; Droste, S.; Samm, U.; Mertens, Ph.; Donne, A.H.; Rudakov, D.; Allen, S.; Boivin, R.; McLean, A.; Stangeby, P.; West, W.; Wong, C.; Lipa, M.; Schunke, B.; De Temmerman, G.; Pitts, R.; Costley, A.; Voitsenya, V.; Vukolov, K.; Oelhafen, P.; Rubel, M.; Romanyuk, A.

    2007-01-01

    Metal mirrors will be implemented in about half of the ITER diagnostics. Mirrors in ITER will have to withstand radiation loads, erosion by charge-exchange neutrals, deposition of impurities, particle implantation and neutron irradiation. It is believed that the optical properties of diagnostic mirrors will be primarily influenced by erosion and deposition. A solution is needed for optimal performance of mirrors in ITER throughout the entire lifetime of the machine. A multi-machine research on diagnostic mirrors is currently underway in fusion facilities at several institutions and laboratories worldwide. Among others, dedicated investigations of ITER-candidate mirror materials are ongoing in Tore-Supra, TEXTOR, DIII-D, TCV, T-10 and JET. Laboratory studies are underway at IPP Kharkov (Ukraine), Kurchatov Institute (Russia) and the University of Basel (Switzerland). An overview of current research on diagnostic mirrors along with an outlook on future investigations is the subject of this paper

  9. A portable and independent edge fluctuation diagnostic. Final performance report, March 1992--March 1993

    International Nuclear Information System (INIS)

    Tsui, H.; Wootton, A.

    1994-01-01

    A compact self contained portable probe system has been designed and developed to diagnose the edge plasma of devices of different sizes and configurations. The system measures both the mean and the fluctuation quantities of density, temperature and potential from a standardized Langmuir probe array using a fast reciprocating probe drive. It can also be used for other fluctuation diagnostics, such as magnetic probes. The data acquisition and analysis is performed on a Macintosh IIfx which provides a user-friendly environment. The results obtained by the signal processing routines are stored in a tabloid format to allow comparative studies. The resulting database is a core part of the protable signal analysis system. To date measurements have been performed on the stellarator ATF, the reversed field pinch ZT40(m), and the tokamaks TEXT, Versator, Phaedrus-T and TFTR. The data are presently being analyzed and the results collected into the database for the purpose of edge turbulence and transport studies. Existing published data are also being included. The edge database, an output of this project, will provide readily available information for other experimental groups to compare their results with, and for theoretical groups to validate (or otherwise) the predictions of their models

  10. Can continuous scans in orthogonal planes improve diagnostic performance of shear wave elastography for breast lesions?

    Science.gov (United States)

    Yang, Pan; Peng, Yulan; Zhao, Haina; Luo, Honghao; Jin, Ya; He, Yushuang

    2015-01-01

    Static shear wave elastography (SWE) is used to detect breast lesions, but slice and plane selections result in discrepancies. To evaluate the intraobserver reproducibility of continuous SWE, and whether quantitative elasticities in orthogonal planes perform better in the differential diagnosis of breast lesions. One hundred and twenty-two breast lesions scheduled for ultrasound-guided biopsy were recruited. Continuous SWE scans were conducted in orthogonal planes separately. Quantitative elasticities and histopathology results were collected. Reproducibility in the same plane and diagnostic performance in different planes were evaluated. The maximum and mean elasticities of the hardest portion, and standard deviation of whole lesion, had high inter-class correlation coefficients (0.87 to 0.95) and large areas under receiver operation characteristic curve (0.887 to 0.899). Without loss of accuracy, sensitivities had increased in orthogonal planes compared with single plane (from 73.17% up to 82.93% at most). Mean elasticity of whole lesion and lesion-to-parenchyma ratio were significantly less reproducible and less accurate. Continuous SWE is highly reproducible for the same observer. The maximum and mean elasticities of the hardest portion and standard deviation of whole lesion are most reliable. Furthermore, the sensitivities of the three parameters are improved in orthogonal planes without loss of accuracies.

  11. Transfer from point-of-care Ultrasonography training to diagnostic performance on patients--a randomized controlled trial

    DEFF Research Database (Denmark)

    Todsen, Tobias; Jensen, Morten Lind; Tolsgaard, Martin Grønnebæk

    2016-01-01

    BACKGROUND: Clinicians are increasingly using point-of-care ultrasonography for bedside examinations of patients. However, proper training is needed in this technique, and it is unknown whether the skills learned from focused Ultrasonography courses are being transferred to diagnostic performance...... test and binary logistic regression, respectively. RESULTS: There was a significant difference in the performance score between the intervention group (27.4%) and the control group (18.0%, P = .004) and the diagnostic accuracy between the intervention group (65%) and the control group (39%, P = .014......). CONCLUSIONS: Clinicians could successfully transfer learning from an Ultrasonography course to improve diagnostic performance on patients. However, our results also indicate a need for more training when new technologies such as point-of-care ultrasonography are introduced....

  12. Diagnostic performance of MRI and MR myelography in infants with a brachial plexus birth injury

    International Nuclear Information System (INIS)

    Medina, L.S.; Yaylali, Ilker; Zurakowski, David; Ruiz, Jennifer; Altman, Nolan R.; Grossman, John A.I.

    2006-01-01

    Detailed evaluation of a brachial plexus birth injury is important for treatment planning. To determine the diagnostic performance of MRI and MR myelography in infants with a brachial plexus birth injury. Included in the study were 31 children with perinatal brachial plexus injury who underwent surgical intervention. All patients had cervical and brachial plexus MRI. The standard of reference was the combination of intraoperative (1) surgical evaluation and (2) electrophysiological studies (motor evoked potentials, MEP, and somatosensory evoked potentials, SSEP), and (3) the evaluation of histopathological neuronal loss. MRI findings of cord lesion, pseudomeningocele, and post-traumatic neuroma were correlated with the standard of reference. Diagnostic performance characteristics including sensitivity and specificity were determined. From June 2001 to March 2004, 31 children (mean age 7.3 months, standard deviation 1.6 months, range 4.8-12.1 months; 19 male, 12 female) with a brachial plexus birth injury who underwent surgical intervention were enrolled. Sensitivity and specificity of an MRI finding of post-traumatic neuroma were 97% (30/31) and 100% (31/31), respectively, using the contralateral normal brachial plexus as the control. However, MRI could not determine the exact anatomic area (i.e. trunk or division) of the post-traumatic brachial plexus neuroma injury. Sensitivity and specificity for an MRI finding of pseudomeningocele in determining exiting nerve injury were 50% and 100%, respectively, using MEP, and 44% and 80%, respectively, using SSEP as the standard of reference. MRI in infants could not image well the exiting nerve roots to determine consistently the presence or absence of definite avulsion. In children younger than 18 months with brachial plexus injury, the MRI finding of pseudomeningocele has a low sensitivity and a high specificity for nerve root avulsion. MRI and MR myelography cannot image well the exiting nerve roots to determine

  13. Pediatric echocardiograms performed at primary centers: Diagnostic errors and missing links!

    International Nuclear Information System (INIS)

    Saraf, Rahul P; Suresh, PV; Maheshwari, Sunita; Shah, Sejal S

    2015-01-01

    The present study was undertaken to assess the accuracy of pediatric echocardiograms done at non-tertiary centers and to evaluate the relationship of inaccurate interpretations with age, echocardiogram performer and complexity of congenital heart disease (CHD). The echocardiogram reports of 182 consecutive children with CHD (5 days-16 years) who were evaluated at a non-tertiary center and subsequently referred to our center were reviewed. Age of the child at echocardiogram, echocardiogram performer and complexity of CHD were noted. These reports were compared with echocardiogram done at our center. Discrepancies were noted and categorized. To assess our own error rate, we compared our echocardiogram reports with the findings obtained during surgery (n = 172), CT scan (n = 9) or cardiac catheterization reports (n = 1). Most of the children at the non-tertiary center (92%) underwent echocardiogram by personnel other than a pediatric cardiologist. Overall, diagnostic errors were found in 69/182 (38%) children. Moderate and major discrepancies affecting the final management were found in 42/182 (23%) children. Discrepancies were higher when the echocardiogram was done by personnel other than pediatric cardiologist (P < 0.01) and with moderate and high complexity lesions (P = 0.0001). There was no significant difference in proportion of these discrepancies in children ≤ 1 year vs. >1 year of age. A significant number of pediatric echocardiograms done at non-tertiary centers had discrepancies that affected the management of these children. More discrepancies were seen when the echocardiogram performer was not a pediatric cardiologist and with complex CHD

  14. Optimized diagnostic performance of brain magnetic resonance imaging in children with idiopathic growth hormone deficiency

    International Nuclear Information System (INIS)

    Rac, M.

    2006-01-01

    Purpose: The aim of this study was to search for correlations between anatomic changes in the pituitary gland and hormonal disturbances in children with short stature. Material and methods: Children with short stature were enrolled when criteria of pituitary growth hormone deficiency were partly or completely met. Magnetic resonance imaging was performed in 87 children and particular attention was given to the pituitary gland. Measurements were compared with pituitary dimensions accepted as normal in the literature. Contrast with GdDTPA was used to visualize the pituitary gland and associated structures (stalk, infundibulum). T1-weighted images in the sagittal and coronal planes were obtained. The results were statistically analyzed with non-parametric tests. Conclusions: 1. Magnetic resonance imaging is a very sensitive method for detecting changes in the pituitary gland and may well be recommended as a method of choice even though the percentage of changes detected with it is rather small. 2. The use of contrast agent may be abandoned to limit costs when searching for cause of growth deficit in children with idiopathic growth hormone deficiency, save for the following cases: hypoplasia or aplasia of the pituitary gland, transection of the stalk, empty sella syndrome or tumor in the central nervous system. 3. Pituitary volume and height appear to be of greatest diagnostic significance, while width (which varies little) can serve as an auxiliary parameter. (author)

  15. Diagnostic performance of a commercial immunoblot assay for myositis antibody testing.

    Science.gov (United States)

    Bundell, Chris; Rojana-Udomsart, Arada; Mastaglia, Frank; Hollingsworth, Peter; McLean-Tooke, Andrew

    2016-06-01

    The objective of this study was to establish a population based reference range for a commercial immunoblot assay detecting myositis specific autoantibodies (MSAs) and myositis associated autoantibodies (MAAs), and to assess the diagnostic performance of this reference range against the manufacturer's recommended ranges in a myositis patient cohort. A total of 124 patients from a myositis cohort and 197 healthy controls were serologically assessed using a commercial immunoblot containing eleven autoantigens (Jo-1, EJ, OJ, PL7, PL12, Mi-2, SRP, Ku, PMScl75, PMScl100 and Ro52) according to the manufacturer's instructions. Use of the manufacturer's reference ranges resulted in detection of MSAs in 19.4% of myositis patients and 9.1% of controls; MAAs were detected in 41.1% of myositis patients and 14.2% of controls. Reference values derived from the healthy control population resulted in significant differences in cut-off values for some autoantibodies, particularly Ro52 and PMScl75. Use of local reference ranges reduced detection of MSAs to 16.9% of myositis patients and 3% of healthy controls, with MAAs 23.4% of patients and 2% of healthy controls. Application of population based reference ranges resulted in significant differences in detection of MSAs and MAAs compared to the manufacturer's recommended ranges. Cut-off levels should be assessed to ensure suitability for the population tested. Copyright © 2016. Published by Elsevier B.V.

  16. Magnetic resonance imaging in local staging of endometrial carcinoma: diagnostic performance, pitfalls, and literature review.

    Science.gov (United States)

    Zandrino, Franco; La Paglia, Ernesto; Musante, Francesco

    2010-01-01

    To assess the diagnostic accuracy of magnetic resonance imaging in local staging of endometrial carcinoma, and to review the results and pitfalls described in the literature. Thirty women with a histological diagnosis of endometrial carcinoma underwent magnetic resonance imaging. Unenhanced T2-weighted and dynamic contrast-enhanced Ti-weighted sequences were obtained. Hysterectomy and salpingo-oophorectomy was performed in all patients. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were calculated for the detection of deep myometrial and cervical infiltration. For deep myometrial infiltration T2-weighted sequences reached a sensitivity of 85%, specificity of 76%, PPV of 73%, NVP of 87%, and accuracy of 80%, while contrast-enhanced scans reached a sensitivity of 90%, specificity of 80%, PPV of 82%, NPV of 89%, and accuracy of 85%. For cervical infiltration T2-weighted sequences reached a sensitivity of 75%, specificity of 88%, PPV of 50%, NPV of 96%, and accuracy of 87%, while contrast-enhanced scans reached a sensitivity of 100%, specificity of 94%, PPV of 75%, NPV of 100%, and accuracy of 95%. Unenhanced and dynamic gadolinium-enhanced magnetic resonance allows accurate assessment of myometrial and cervical infiltration. Information provided by magnetic resonance imaging can define prognosis and management.

  17. Performance of diagnostic biomarkers in predicting liver fibrosis among hepatitis C virus-infected Egyptian children

    Directory of Open Access Journals (Sweden)

    Yasser E Nassef

    2013-11-01

    Full Text Available The aim of the present study was to identify specific markers that mirror liver fibrosis progression as an alternative to biopsy when biopsy is contraindicated, especially in children. After liver biopsies were performed, serum samples from 30 hepatitis C virus (HCV paediatric patients (8-14 years were analysed and compared with samples from 30 healthy subjects. All subjects were tested for the presence of serum anti-HCV antibodies. Direct biomarkers for liver fibrosis, including transforming growth factor-β1, tissue inhibitor of matrix metalloproteinase-1 (TIMP-1, hyaluronic acid (HA, procollagen type III amino-terminal peptide (PIIINP and osteopontin (OPN, were measured. The indirect biomarkers aspartate and alanine aminotransferases, albumin and bilirubin were also tested. The results revealed a significant increase in the serum marker levels in HCV-infected children compared with the healthy group, whereas albumin levels exhibited a significant decrease. Significantly higher levels of PIIINP, TIMP-1, OPN and HA were detected in HCV-infected children with moderate to severe fibrosis compared with children with mild fibrosis (p < 0.05. The diagnostic accuracy of these direct biomarkers, represented by sensitivity, specificity and positive predictive value, emphasises the utility of PIIINP, TIMP-1, OPN and HA as indicators of liver fibrosis among HCV-infected children.

  18. Comparison of 3MP medical-grade to 1MP office grade LCD monitors in mammographic diagnostic and perceptual performance

    International Nuclear Information System (INIS)

    Ong, Aaron; Tan, Shu.; Gledhill, Samuel; Hennessy, Oliver; Lui, Belinda; Lee, Alan; Lemish, Wayne; Styles, Colin; Pun, Emma; Padmanabhan, Meenakshi; Pitman, Alexander G.; Tauro, Paul; Waugh, Paul

    2011-01-01

    Full text: Picture archiving and communication systems images designed to be viewed on high-resolution medical-grade monitors are routinely viewed on office-grade monitors on the wards or at home. This study aimed to determine whether a statistically significant difference in diagnostic (cancer detection) and perceptual (microcalcification detection) performance exists between 3MP grade and 1MP office-grade monitors. 3MP Dome medical-grade liquid crystal display (LCD) monitors (Planar, Beaverton, OR, USA) were compared to 1MP Dell office-grade LCD monitors (Dell Inc, Round Rock, TX, USA). Eight radiologists (reader experi ence 8-30 years) read the same set of 100 mammograms (23/100 with proven cancers and 52/100 with microcalcifications) presented in random order on three occasions separated by two time intervals of 12 weeks. Reads 1 and 3 utilised 3MP monitors and formed the baseline read. Read 2 utilised 1MP monitors and constituted the experimental read. Reading conditions were standardised. Readers were aware of which monitors they were using. Mul tivariate logistic regression analysis (to account for reader variability and monitor impact) was performed to assess for statistical significance. At a = 5%, confidence intervals analysis comparing the measured parameters between 1MP to 3MP monitors demonstrated no statistically significant difference in diagnostic and perceptual performance for the reader group. In cancer detection (the diagnostic task), reader accuracy remained high irrespective of monitor type. Regression analysis comparing performance with 1MP against 3MP monitors found P values of 0.693 and 0.324 for diagnostic and perceptual performance, respectively. There were no statistically and clinically significant differences between 3MP and 1MP monitors in mammographic diagnostic and perceptual performance. Comparable performance may be due to compensatory behav iour by readers.

  19. Comparison of diagnostic performance for perinatal and paediatric post-mortem imaging: CT versus MRI

    International Nuclear Information System (INIS)

    Arthurs, Owen J.; Jacques, Thomas S.; Sebire, Neil J.; Guy, Anna; Chong, W.K.; Gunny, Roxanna; Saunders, Dawn; Olsen, Oystein E.; Thayyil, Sudhin; Wade, Angie; Jones, Rod; Norman, Wendy; Taylor, Andrew M.; Scott, Rosemary; Robertson, Nicola J.; Owens, Catherine M.; Offiah, Amaka C.; Chitty, Lyn S.

    2016-01-01

    To compare the diagnostic yield of whole-body post-mortem computed tomography (PMCT) imaging to post-mortem magnetic resonance (PMMR) imaging in a prospective study of fetuses and children. We compared PMCT and PMMR to conventional autopsy as the gold standard for the detection of (a) major pathological abnormalities related to the cause of death and (b) all diagnostic findings in five different body organ systems. Eighty two cases (53 fetuses and 29 children) underwent PMCT and PMMR prior to autopsy, at which 55 major abnormalities were identified. Significantly more PMCT than PMMR examinations were non-diagnostic (18/82 vs. 4/82; 21.9 % vs. 4.9 %, diff 17.1 % (95 % CI 6.7, 27.6; p < 0.05)). PMMR gave an accurate diagnosis in 24/55 (43.64 %; 95 % CI 31.37, 56.73 %) compared to 18/55 PMCT (32.73 %; 95 % CI 21.81, 45.90). PMCT was particularly poor in fetuses <24 weeks, with 28.6 % (8.1, 46.4 %) more non-diagnostic scans. Where both PMCT and PMMR were diagnostic, PMMR gave slightly higher diagnostic accuracy than PMCT (62.8 % vs. 59.4 %). Unenhanced PMCT has limited value in detection of major pathology primarily because of poor-quality, non-diagnostic fetal images. On this basis, PMMR should be the modality of choice for non-invasive PM imaging in fetuses and children. (orig.)

  20. CT imaging of congenital lung lesions: effect of iterative reconstruction on diagnostic performance and radiation dose

    International Nuclear Information System (INIS)

    Haggerty, Jay E.; Smith, Ethan A.; Dillman, Jonathan R.; Kunisaki, Shaun M.

    2015-01-01

    Different iterative reconstruction techniques are available for use in pediatric computed tomography (CT), but these techniques have not been systematically evaluated in infants. To determine the effect of iterative reconstruction on diagnostic performance, image quality and radiation dose in infants undergoing CT evaluation for congenital lung lesions. A retrospective review of contrast-enhanced chest CT in infants (<1 year) with congenital lung lesions was performed. CT examinations were reviewed to document the type of lung lesion, vascular anatomy, image noise measurements and image reconstruction method. CTDI vol was used to calculate size-specific dose estimates (SSDE). CT findings were correlated with intraoperative and histopathological findings. Analysis of variance and the Student's t-test were used to compare image noise measurements and radiation dose estimates between groups. Fifteen CT examinations used filtered back projection (FBP; mean age: 84 days), 15 used adaptive statistical iterative reconstruction (ASiR; mean age: 93 days), and 11 used model-based iterative reconstruction (MBIR; mean age: 98 days). Compared to operative findings, 13/15 (87%), 14/15 (93%) and 11/11 (100%) lesions were correctly characterized using FBP, ASiR and MBIR, respectively. Arterial anatomy was correctly identified in 12/15 (80%) using FBP, 13/15 (87%) using ASiR and 11/11 (100%) using MBIR. Image noise was less for MBIR vs. ASiR (P < 0.0001). Mean SSDE was different among groups (P = 0.003; FBP = 7.35 mGy, ASiR = 1.89 mGy, MBIR = 1.49 mGy). Congenital lung lesions can be adequately characterized in infants using iterative CT reconstruction techniques while maintaining image quality and lowering radiation dose. (orig.)

  1. High-performance pickups for beam diagnostics. Design, analysis, characterization and implementation

    International Nuclear Information System (INIS)

    Angelovski, Aleksandar

    2015-01-01

    This work introduces the design, analysis, characterization and implementation of high-performance pickups for two beam diagnostic instruments, a Bunch Arrival-time Monitor (BAM) and an Energy Beam Position Monitor (EBPM) at the European XFEL. As a part of the BAM the cone-shaped pickups are proposed along with the corresponding RF-frontend. The designed pickups deliver a beam induced signal with a slope steepness of around 400 mV/ps and a bandwidth of 40 GHz. These signal characteristics are well inside the design requirements, i.e., a slope steepness of 300 mV/ps and more than ten times better compared to the signal from the state-of-the-art pickups. The pickups are installed and commissioned at three accelerator facilities, FLASH at DESY, the quasi-CW SRF accelerator ELBE at the Helmholtz-Zentrum Dresden-Rossendorf and the SwissFEL injector test facility at Paul Scherrer Institute. The obtained measurement results from the installed pickups are in good agreement with the simulations. A comparison between the signal measurements with the cone-shaped pickup and the state-of-the-art is performed at ELBE showing an improvement by a factor of ten. The potential of the pickups for sub-10 fs arrival-time measurements for bunch charges of 20 pC is demonstrated at ELBE and at SwissFEL injector test facility. The introduced coneshaped pickups are the first commercially available pickups with a bandwidth of up to 40 GHz. For the EBPM, a modular pickup structure with two types of planar pickups, microstrip transmission line and grounded coplanar waveguide with perpendicular connectors is investigated. The transition region between the connector and the line is optimized for two substrate materials, alumina and glass with a reflection coefficient better than -20 dB up to 6 GHz.

  2. Diagnostic performance of the upper gastrointestinal series in the evaluation of children with clinically suspected malrotation

    International Nuclear Information System (INIS)

    Sizemore, Alecia W.; Rabbani, Kaneez Z.; Ladd, Alan; Applegate, Kimberly E.

    2008-01-01

    Malrotation is a congenital disorder of abnormal intestinal rotation and fixation that predisposes infants to potentially life-threatening midgut volvulus. Upper gastrointestinal tract (UGI) examination is sometimes equivocal and can lead to inaccurate diagnosis. To determine the diagnostic performance of UGI examinations in children who subsequently underwent a Ladd procedure for suspected malrotation or volvulus. We reviewed all children up to 21 years old who had undergone both a UGI examination and a Ladd procedure for possible malrotation across 9 years. Children were excluded if they had not undergone either a UGI examination or a Ladd procedure and if congenital abdominal wall defects were present. Of 229 patients identified, 166 (59% male, median age 67 days) were included. Excluded were 47 without a UGI series, 12 with omphalocele or gastroschisis, 1 without verifiable operative data, 1 who had not undergone a Ladd procedure, and 2 older than 21 years. Of the 166 patients, 40% were neonates and 73% were <12 months old, and 31% presented with bilious vomiting and 15% with abdominal distention. Of 163 patients with surgically verified malrotation, 156 had a positive UGI examination, a sensitivity of 96%. There were two patients with a false-positive UGI examination and seven with false-negative examination. Jejunal position was normal in six of the seven with a false-negative examination and abnormal in the two with a false-positive examination. Of 38 patients with surgically verified volvulus, 30 showed volvulus on the UGI series. Five required bowel resection and three died. Jejunal position can lead to inaccurate UGI series interpretation. Meticulous technique and periodic assessment of performance will help more accurately diagnose difficult or equivocal cases. (orig.)

  3. Diagnostic performance of the upper gastrointestinal series in the evaluation of children with clinically suspected malrotation

    Energy Technology Data Exchange (ETDEWEB)

    Sizemore, Alecia W [Indiana University School of Medicine, Department of Radiology, Indianapolis, IN (United States); University of Virginia School of Medicine, Department of Radiology, Charlottesville, VA (United States); Rabbani, Kaneez Z [Indiana University School of Medicine, Department of Medicine, Indianapolis, IN (United States); Ladd, Alan [Indiana University School of Medicine, Division of Pediatric Surgery, Riley Hospital, Indianapolis, IN (United States); Applegate, Kimberly E [Indiana University School of Medicine, Section of Pediatric Radiology, Department of Radiology, Indianapolis, IN (United States); Riley Hospital for Children, Department of Radiology, Indianapolis, IN (United States)

    2008-05-15

    Malrotation is a congenital disorder of abnormal intestinal rotation and fixation that predisposes infants to potentially life-threatening midgut volvulus. Upper gastrointestinal tract (UGI) examination is sometimes equivocal and can lead to inaccurate diagnosis. To determine the diagnostic performance of UGI examinations in children who subsequently underwent a Ladd procedure for suspected malrotation or volvulus. We reviewed all children up to 21 years old who had undergone both a UGI examination and a Ladd procedure for possible malrotation across 9 years. Children were excluded if they had not undergone either a UGI examination or a Ladd procedure and if congenital abdominal wall defects were present. Of 229 patients identified, 166 (59% male, median age 67 days) were included. Excluded were 47 without a UGI series, 12 with omphalocele or gastroschisis, 1 without verifiable operative data, 1 who had not undergone a Ladd procedure, and 2 older than 21 years. Of the 166 patients, 40% were neonates and 73% were <12 months old, and 31% presented with bilious vomiting and 15% with abdominal distention. Of 163 patients with surgically verified malrotation, 156 had a positive UGI examination, a sensitivity of 96%. There were two patients with a false-positive UGI examination and seven with false-negative examination. Jejunal position was normal in six of the seven with a false-negative examination and abnormal in the two with a false-positive examination. Of 38 patients with surgically verified volvulus, 30 showed volvulus on the UGI series. Five required bowel resection and three died. Jejunal position can lead to inaccurate UGI series interpretation. Meticulous technique and periodic assessment of performance will help more accurately diagnose difficult or equivocal cases. (orig.)

  4. CT imaging of congenital lung lesions: effect of iterative reconstruction on diagnostic performance and radiation dose

    Energy Technology Data Exchange (ETDEWEB)

    Haggerty, Jay E.; Smith, Ethan A.; Dillman, Jonathan R. [University of Michigan Health System, Section of Pediatric Radiology, Department of Radiology, C.S. Mott Children' s Hospital, Ann Arbor, MI (United States); Kunisaki, Shaun M. [University of Michigan Health System, Section of Pediatric Surgery, Department of Surgery, C.S. Mott Children' s Hospital, Ann Arbor, MI (United States)

    2015-07-15

    Different iterative reconstruction techniques are available for use in pediatric computed tomography (CT), but these techniques have not been systematically evaluated in infants. To determine the effect of iterative reconstruction on diagnostic performance, image quality and radiation dose in infants undergoing CT evaluation for congenital lung lesions. A retrospective review of contrast-enhanced chest CT in infants (<1 year) with congenital lung lesions was performed. CT examinations were reviewed to document the type of lung lesion, vascular anatomy, image noise measurements and image reconstruction method. CTDI{sub vol} was used to calculate size-specific dose estimates (SSDE). CT findings were correlated with intraoperative and histopathological findings. Analysis of variance and the Student's t-test were used to compare image noise measurements and radiation dose estimates between groups. Fifteen CT examinations used filtered back projection (FBP; mean age: 84 days), 15 used adaptive statistical iterative reconstruction (ASiR; mean age: 93 days), and 11 used model-based iterative reconstruction (MBIR; mean age: 98 days). Compared to operative findings, 13/15 (87%), 14/15 (93%) and 11/11 (100%) lesions were correctly characterized using FBP, ASiR and MBIR, respectively. Arterial anatomy was correctly identified in 12/15 (80%) using FBP, 13/15 (87%) using ASiR and 11/11 (100%) using MBIR. Image noise was less for MBIR vs. ASiR (P < 0.0001). Mean SSDE was different among groups (P = 0.003; FBP = 7.35 mGy, ASiR = 1.89 mGy, MBIR = 1.49 mGy). Congenital lung lesions can be adequately characterized in infants using iterative CT reconstruction techniques while maintaining image quality and lowering radiation dose. (orig.)

  5. Weather-enabled future onboard surveillance and navigation systems

    Science.gov (United States)

    Mutuel, L.; Baillon, B.; Barnetche, B.; Delpy, P.

    2009-09-01

    With the increasing traffic and the development of business trajectories, there is a widespread need to anticipate any adverse weather conditions that could impact the performance of the flight or to use of atmospheric parameters to optimize trajectories. Current sensors onboard air transport are challenged to provide the required service, while new products for business jets and general aviation open the door to innovative assimilation of weather information in onboard surveillance and navigation. The paper aims at surveying current technology available to air transport aircraft and pointing out their shortcomings in view of the modernization proposed in SESAR and NextGen implementation plans. Foreseen innovations are then illustrated via results of ongoing research like FLYSAFE or standardization efforts, in particular meteorological datalink services and impact on Human-Machine Interface. The paper covers the operational need to avoid adverse weather like thunderstorm, icing, turbulence, windshear and volcanic ash, but also the requirement to control in 4D the trajectory through the integration of wind and temperature grids in the flight management. The former will lead to enhanced surveillance systems onboard the aircraft with new displays and new alerting schemes, ranging from targeted information supporting better re-planning to auto-escape strategies. The latter will be standard in next generation flight management systems. Finally both will rely on ATM products that will also assimilate weather information so that situational awareness is shared and decision is collaborative.

  6. Automation of On-Board Flightpath Management

    Science.gov (United States)

    Erzberger, H.

    1981-01-01

    The status of concepts and techniques for the design of onboard flight path management systems is reviewed. Such systems are designed to increase flight efficiency and safety by automating the optimization of flight procedures onboard aircraft. After a brief review of the origins and functions of such systems, two complementary methods are described for attacking the key design problem, namely, the synthesis of efficient trajectories. One method optimizes en route, the other optimizes terminal area flight; both methods are rooted in optimal control theory. Simulation and flight test results are reviewed to illustrate the potential of these systems for fuel and cost savings.

  7. Using Onboard Telemetry for MAVEN Orbit Determination

    Science.gov (United States)

    Lam, Try; Trawny, Nikolas; Lee, Clifford

    2013-01-01

    Determination of the spacecraft state has been traditional done using radiometric tracking data before and after the atmosphere drag pass. This paper describes our approach and results to include onboard telemetry measurements in addition to radiometric observables to refine the reconstructed trajectory estimate for the Mars Atmosphere and Volatile Evolution Mission (MAVEN). Uncertainties in the Mars atmosphere models, combined with non-continuous tracking degrade navigation accuracy, making MAVEN a key candidate for using onboard telemetry data to help complement its orbit determination process.

  8. Performance of Different Diagnostic Criteria for Familial Mediterranean Fever in Children with Periodic Fevers : Results from a Multicenter International Registry

    NARCIS (Netherlands)

    Demirkaya, Erkan; Saglam, Celal; Turker, Turker; Koné-Paut, Isabelle; Woo, Pat; Doglio, Matteo; Amaryan, Gayane; Frenkel, Joost; Uziel, Yosef; Insalaco, Antonella; Cantarini, Luca; Hofer, Michael; Boiu, Sorina; Duzova, Ali; Modesto, Consuelo; Bryant, Annette; Rigante, Donato; Papadopoulou-Alataki, Efimia; Guillaume-Czitrom, Severine; Kuemmerle-Deschner, Jasmine; Neven, Bénédicte; Lachmann, Helen; Martini, Alberto; Ruperto, Nicolino; Gattorno, Marco; Ozen, Seza

    2015-01-01

    OBJECTIVE: Our aims were to validate the pediatric diagnostic criteria in a large international registry and to compare them with the performance of previous criteria for the diagnosis of familial Mediterranean fever (FMF). METHODS: Pediatric patients with FMF from the Eurofever registry were used

  9. Alzheimer's Disease Diagnostic Performance of a Multi-Atlas Hippocampal Segmentation Method using the Harmonized Hippocampal Protocol

    DEFF Research Database (Denmark)

    Anker, Cecilie Benedicte; Sørensen, Lauge; Pai, Akshay

    PURPOSE Hippocampal volumetry is the most widely used structural MRI biomarker of Alzheimer’s disease (AD), and state-of-the-art, automatic hippocampal segmentation can be obtained using longitudinal FreeSurfer. In this study, we compare the diagnostic AD performance of a single time point, multi...

  10. Multiparametric MRI of the prostate: diagnostic performance and interreader agreement of two scoring systems.

    Science.gov (United States)

    Lin, Wei-Ching; Muglia, Valdair F; Silva, Gyl E B; Chodraui Filho, Salomão; Reis, Rodolfo B; Westphalen, Antonio C

    2016-06-01

    To compare the diagnostic accuracies and interreader agreements of the Prostate Imaging Reporting and Data System (PI-RADS) v. 2 and University of California San Francisco (UCSF) multiparametric prostate MRI scale for diagnosing clinically significant prostate cancer. This institutional review board-approved retrospective study included 49 males who had 1.5 T endorectal MRI and prostatectomy. Two radiologists scored suspicious lesions on MRI using PI-RADS v. 2 and the UCSF scale. Percent agreement, 2 × 2 tables and the area under the receiver operating characteristic curves (Az) were used to assess and compare the individual and overall scores of these scales. Interreader agreements were estimated with kappa statistics. Reader 1 (R1) detected 78 lesions, and Reader 2 (R2) detected 80 lesions. Both identified 52 of 65 significant cancers. The Az for PI-RADS v. 2 and UCSF scale for R1 were 0.68 and 0.69 [T2 weighted imaging (T2WI)], 0.75 and 0.68 [diffusion-weighted imaging (DWI)] and 0.64 and 0.72 (overall score), respectively, and were 0.72 and 0.75 (T2WI), 0.73 and 0.67 (DWI) and 0.66 and 0.75 (overall score) for R2. The dynamic contrast-enhanced percent agreements between scales were 100% (R1) and 95% (R2). PI-RADS v. 2 DWI of R1 performed better than UCSF DWI (Az = 0.75 vs Az = 0.68; p = 0.05); no other differences were found. The interreader agreements were higher for PI-RADS v. 2 (T2WI: 0.56 vs 0.42; DWI: 0.60 vs 0.46; overall: 0.61 vs 0.42). The UCSF approach to derive the overall PI-RADS v. 2 scores increased the Az for the identification of significant cancer (R1 to 0.76, p < 0.05; R2 to 0.71, p = 0.35). Although PI-RADS v. 2 DWI score may have a higher discriminatory performance than the UCSF scale counterpart to diagnose clinically significant cancer, the utilization of the UCSF scale weighing system for the integration of PI-RADS v. 2 individual parameter scores improved the accuracy its overall score. PI-RADS v. 2 is

  11. Performance assessment and adoption processes of an information monitoring and diagnostic system prototype; FINAL

    International Nuclear Information System (INIS)

    Piette, Mary Ann

    1999-01-01

    This report addresses the problem that buildings do not perform as well as anticipated during design. We partnered with an innovative building operator to evaluate a prototype Information Monitoring and Diagnostic System (IMDS). The IMDS consists of high-quality measurements archived each minute, a data visualization tool, and a web-based capability. The operators recommend similar technology be adopted in other buildings. The IMDS has been used to identify and correct a series of control problems. It has also allowed the operators to make more effective use of the building control system, freeing up time to take care of other tenant needs. They believe they have significantly improved building comfort, potentially improving tenant health, and productivity. The reduction in hours to operate the building are worth about$20,000 per year, which could pay for the IMDS in about five years. A control system retrofit based on findings from the IMDS is expected to reduce energy use by 20 percent over the next year, worth over$30,000 per year. The main conclusion of the model-based chiller fault detection work is that steady-state models can be used as reference models to monitor chiller operation and detect faults. The ability of the IMDS to measure cooling load and chiller power to one-percent accuracy with a one-minute sampling interval permits detection of additional faults. Evolutionary programming techniques were also evaluated, showing promise in the detection of patterns in building data. We also evaluated two technology adoption processes, radical and routine. In routine adoption, managers enhance features of existing products that are already well understood. In radical adoption, innovative building managers introduce novel technology into their organizations without using the rigorous payback criteria used in routine innovations

  12. Diagnostic performance of radiographers as compared to radiologists in magnetic resonance colonography

    International Nuclear Information System (INIS)

    Zijta, F.M.; Florie, J.; Jensch, S.; Bipat, S.; Nievelstein, R.A.J.; Poulus, M.; Thomassen-de Graaf, M.A.; Montauban van Swijndregt, A.D.; Stoker, J.

    2010-01-01

    Purpose: To evaluate the diagnostic performance of radiographers compared to radiologists in the detection of colorectal lesions in MR colonography. Material and methods: 159 patients at increased risk of colorectal cancer were included. Four different experienced observers, one MR radiologist, one radiologist in training and two radiographers evaluated all MR colonography examinations. The protocol included T1-weighted and T2-weighted sequences in prone and supine position. Colonoscopy was used as reference standard. Mean sensitivity rates with 95% confidence intervals (CIs) were determined on a per-patient and per-polyp basis, segmented by size (≥6 mm and ≥10 mm). Specificity was calculated on a per-patient basis. The McNemar and chi-square (χ 2 ) test was used to determine significant differences. Results: At colonoscopy 74 patients (47%) had normal findings; 23 patients had 40 polyps with a size ≥6 mm. In 10 patients at least 1 polyp ≥10 mm was found (20 polyps in total). Similar sensitivities for patients with lesions ≥10 mm were found for radiologists and radiographers (65% (95%CI: 44-86%) vs. 50% (95%CI: 28-72%)) (p = n.s.). For lesions ≥10 mm combined per-patient specificity for radiologists and radiographers was 96% (95%CI: 94-98%) and 73% (95%CI: 68-79%) (p < 0.0001). Combined per-patient sensitivity for lesions ≥6 mm differed significantly between both groups of observers (57% (95%CI: 42-71%) vs. 33% (95%CI: 19-46%)) (p = 0.03). Conclusion: Radiographers have comparable sensitivity but lower specificity relative to radiologists in the detection of colorectal lesions ≥10 mm at MR colonography. Adequate training in evaluating MR colonography is necessary, especially for readers with no prior experience with colonography.

  13. Performance assessment and adoption processes of an information monitoring and diagnostic system prototype

    Energy Technology Data Exchange (ETDEWEB)

    Piette, Mary Ann

    1999-10-01

    This report addresses the problem that buildings do not perform as well as anticipated during design. We partnered with an innovative building operator to evaluate a prototype Information Monitoring and Diagnostic System (IMDS). The IMDS consists of high-quality measurements archived each minute, a data visualization tool, and a web-based capability. The operators recommend similar technology be adopted in other buildings. The IMDS has been used to identify and correct a series of control problems. It has also allowed the operators to make more effective use of the building control system, freeing up time to take care of other tenant needs. They believe they have significantly improved building comfort, potentially improving tenant health, and productivity. The reduction in hours to operate the building are worth about $20,000 per year, which could pay for the IMDS in about five years. A control system retrofit based on findings from the IMDS is expected to reduce energy use by 20 percent over the next year, worth over $30,000 per year. The main conclusion of the model-based chiller fault detection work is that steady-state models can be used as reference models to monitor chiller operation and detect faults. The ability of the IMDS to measure cooling load and chiller power to one-percent accuracy with a one-minute sampling interval permits detection of additional faults. Evolutionary programming techniques were also evaluated, showing promise in the detection of patterns in building data. We also evaluated two technology adoption processes, radical and routine. In routine adoption, managers enhance features of existing products that are already well understood. In radical adoption, innovative building managers introduce novel technology into their organizations without using the rigorous payback criteria used in routine innovations.

  14. Diagnostic performance of bone metabolic indexes for the detection of stroke

    Directory of Open Access Journals (Sweden)

    Li-Ming Tan

    2017-01-01

    Full Text Available Objectives: To explore the diagnostic performance of 25-hydroxyvitamin D (25(OHD, parathyroid hormone (PTH, bone alkaline phosphatase (BALP, and osteocalcin (OC in predicting stroke. Methods: This retrospective survey was conducted in The Second Affiliated Hospital to Nanchang University, Nanchang, Jiangxi Province, China. involved 121 cerebral infarction patients and 103 cerebral hemorrhage patients as the experimental groups, 100 volunteers as the healthy control group and 80 brain trauma patients as the disease control group. The 25(OHD, PTH, BALP, and OC levels of all participants were measured by electrochemiluminescence immunoassay. Results: The serum concentration of 25(OHD in stroke patients was appreciably lower than that of the control groups (p<0.05, and subsequently, the deficiency level of 25(OHD in the stroke population was considerably higher than that of the control groups (p<0.05. The serum concentrations of PTH and OC in stroke patients exceeded those found in the control groups (p<0.05, and the abnormal level in the stroke patients was also higher than that of the control. Compared with the control group, BALP concentrations in cerebral infarction patients were increased significantly. Additionally, abnormal levels of BALP in stroke patients were found to be higher than those in the control groups. However, concentrations and abnormal levels of BALP in cerebral hemorrhage patients were not found to be significantly different than those found in cerebral infarction and the control groups, There were no substantial differences between the 2 control groups. Conclusion: Lack of 25(OHD and excessive PTH, BALP, and OC could indicate a high risk of stroke.

  15. Diagnostic performance of body mass index to identify excess body fat in children with cerebral palsy.

    Science.gov (United States)

    Duran, Ibrahim; Schulze, Josefa; Martakis, KyriakoS; Stark, Christina; Schoenau, Eckhard

    2018-03-07

    To assess the diagnostic performance of body mass index (BMI) cut-off values according to recommendations of the World Health Organization (WHO), the World Obesity Federation (WOF), and the German Society for Adiposity (DAG) to identify excess body fat in children with cerebral palsy (CP). The present study was a monocentric retrospective analysis of prospectively collected data among children and adolescents with CP participating in a rehabilitation programme. Excess body fat was defined as a body fat percentage above the 85th centile assessed by dual-energy X-ray absorptiometry. In total, 329 children (181 males, 148 females) with CP were eligible for analysis. The mean age was 12 years 4 months (standard deviation 2y 9mo). The BMI cut-off values for 'overweight' according to the WHO, WOF, and DAG showed the following sensitivities and specificities for the prediction of excess body fat in our population: WHO: sensitivity 0.768 (95% confidence interval [CI] 0.636-0.870), specificity 0.894 (95% CI 0.851-0.928); WOF: sensitivity 0.696 (95% CI 0.559-0.812), specificity 0.934 (95% CI 0.898-0.960); DAG: sensitivity 0.411 (95% CI 0.281-0.550), specificity 0.993 (95% CI 0.974-0.999). Body mass index showed high specificity, but low sensitivity in children with CP. Thus, 'normal-weight obese' children with CP were overlooked, when assessing excess body fat only using BMI. Excess body fat in children with cerebral palsy (CP) is less common than previously reported. Body mass index (BMI) had high specificity but low sensitivity in detecting excess body fat in children with CP. BMI evaluation criteria of the German Society for Adiposity could be improved in children with CP. © 2018 Mac Keith Press.

  16. Diagnostic Performance of a Rapid Magnetic Resonance Imaging Method of Measuring Hepatic Steatosis

    Science.gov (United States)

    House, Michael J.; Gan, Eng K.; Adams, Leon A.; Ayonrinde, Oyekoya T.; Bangma, Sander J.; Bhathal, Prithi S.; Olynyk, John K.; St. Pierre, Tim G.

    2013-01-01

    Objectives Hepatic steatosis is associated with an increased risk of developing serious liver disease and other clinical sequelae of the metabolic syndrome. However, visual estimates of steatosis from histological sections of biopsy samples are subjective and reliant on an invasive procedure with associated risks. The aim of this study was to test the ability of a rapid, routinely available, magnetic resonance imaging (MRI) method to diagnose clinically relevant grades of hepatic steatosis in a cohort of patients with diverse liver diseases. Materials and Methods Fifty-nine patients with a range of liver diseases underwent liver biopsy and MRI. Hepatic steatosis was quantified firstly using an opposed-phase, in-phase gradient echo, single breath-hold MRI methodology and secondly, using liver biopsy with visual estimation by a histopathologist and by computer-assisted morphometric image analysis. The area under the receiver operating characteristic (ROC) curve was used to assess the diagnostic performance of the MRI method against the biopsy observations. Results The MRI approach had high sensitivity and specificity at all hepatic steatosis thresholds. Areas under ROC curves were 0.962, 0.993, and 0.972 at thresholds of 5%, 33%, and 66% liver fat, respectively. MRI measurements were strongly associated with visual (r2 = 0.83) and computer-assisted morphometric (r2 = 0.84) estimates of hepatic steatosis from histological specimens. Conclusions This MRI approach, using a conventional, rapid, gradient echo method, has high sensitivity and specificity for diagnosing liver fat at all grades of steatosis in a cohort with a range of liver diseases. PMID:23555650

  17. Accurate Point-of-Care Detection of Ruptured Fetal Membranes: Improved Diagnostic Performance Characteristics with a Monoclonal/Polyclonal Immunoassay

    Directory of Open Access Journals (Sweden)

    Linda C. Rogers

    2016-01-01

    Full Text Available Objective Accurate and timely diagnosis of rupture of membranes (ROM is imperative to allow for gestational age-specific interventions. This study compared the diagnostic performance characteristics between two methods used for the detection of ROM as measured in the same patient. Methods Vaginal secretions were evaluated using the conventional fern test as well as a point-of-care monoclonal/polyclonal immunoassay test (ROM Plus® in 75 pregnant patients who presented to labor and delivery with complaints of leaking amniotic fluid. Both tests were compared to analytical confirmation of ROM using three external laboratory tests. Diagnostic performance characteristics were calculated including sensitivity, specificity, positive predictive value (PPV, negative predictive value (NPV, and accuracy. Results Diagnostic performance characteristics uniformly favored ROM detection using the immunoassay test compared to the fern test: sensitivity (100% vs. 77.8%, specificity (94.8% vs. 79.3%, PPV (75% vs. 36.8%, NPV (100% vs. 95.8%, and accuracy (95.5% vs. 79.1%. Conclusions The point-of-care immunoassay test provides improved diagnostic accuracy for the detection of ROM compared to fern testing. It has the potential of improving patient management decisions, thereby minimizing serious complications and perinatal morbidity.

  18. Dust Measurements Onboard the Deep Space Gateway

    Science.gov (United States)

    Horanyi, M.; Kempf, S.; Malaspina, D.; Poppe, A.; Srama, R.; Sternovsky, Z.; Szalay, J.

    2018-02-01

    A dust instrument onboard the Deep Space Gateway will revolutionize our understanding of the dust environment at 1 AU, help our understanding of the evolution of the solar system, and improve dust hazard models for the safety of crewed and robotic missions.

  19. Preclinical study of diagnostic performances of contrast-enhanced spectral mammography versus MRI for breast diseases in China.

    Science.gov (United States)

    Wang, Qingguo; Li, Kangan; Wang, Lihui; Zhang, Jianbing; Zhou, Zhiguo; Feng, Yan

    2016-01-01

    To evaluate diagnostic performances of CESM for breast diseases with comparison to breast MRI in China. Sixty-eight patients with 77 breast lesions underwent MR and CESM. Two radiologists interpreted either MRI or CESM images, separately and independently. BI-RADS 1-3 and BI-RADS 4-5 were classified into the suspicious benign and suspicious malignant groups. Diagnostic accuracy parameters were calculated. Receiver operating characteristic (ROC) curves were constructed for the two modalities. The agreement and correlation between maximum lesion diameter based on CESM and MRI, or CESM and pathology were analyzed. Diagnostic accuracy parameters for CESM were sensitivity 95.8 %, specificity 65.5 %, PPV 82.1 %, NPV 90.5 % and accuracy 84.4 %. The diagnostic accuracy parameters for breast MRI were sensitivity 93.8 %, specificity 82.8 %, PPV 88.2 %, NPV 92.3 %and accuracy 89.6 %. Area under the curve (AUC) of ROC was 0.96 for breast MRI and 0.88 for CESM. The Bland-Altman plots showed a mean difference of 0.7 mm with 95 % limits of agreement of 11.4 mm in tumor diameter measured using CESM and breast MRI. The differences of size measurement between CESM and breast MRI were significant, whereas no difference was observed between CESM and pathology as well as between breast MRI and pathology. The better correlation with pathological results was found in CESM than breast MRI. Our study demonstrates that CESM possesses better diagnostic performances than breast MRI in terms of diagnostic sensitivity and lesion size assessment. And CESM is a good alternative method of screening breast cancer in high-risk people.

  20. The effect of question format and task difficulty on reasoning strategies and diagnostic performance in Internal Medicine residents.

    Science.gov (United States)

    Heemskerk, Laura; Norman, Geoff; Chou, Sophia; Mintz, Marcy; Mandin, Henry; McLaughlin, Kevin

    2008-11-01

    Previous studies have suggested an association between reasoning strategies and diagnostic success, but the influence on this relationship of variables such as question format and task difficulty, has not been studied. Our objective was to study the association between question format, task difficulty, reasoning strategies and diagnostic success. Study participants were 13 Internal Medicine residents at the University of Calgary. Each was given eight problem-solving questions in four clinical presentations and were randomized to groups that differed only in the question format, such that a question presented as short answer (SA) to the first group was presented as extended matching (EM) to the second group. There were equal numbers of SA/EM questions and straightforward/difficult tasks. Participants performed think-aloud during diagnostic reasoning. Data were analyzed using multiple logistic regression. Question format was associated with reasoning strategies; hypothetico-deductive reasoning being used more frequently on EM questions and scheme-inductive reasoning on SA questions. For SA question, non-analytic reasoning alone was used more frequently to answer straightforward cases than difficult cases, whereas for EM questions no such association was observed. EM format and straightforward task increased the odds of diagnostic success, whereas hypothetico-deductive reasoning was associated with reduced odds of success. Question format and task difficulty both influence diagnostic reasoning strategies and studies that examine the effect of reasoning strategies on diagnostic success should control for these effects. Further studies are needed to investigate the effect of reasoning strategies on performance of different groups of learners.

  1. Tomosynthesis for the early detection of pulmonary emphysema: diagnostic performance compared with chest radiography, using multidetector computed tomography as reference

    International Nuclear Information System (INIS)

    Yamada, Yoshitake; Jinzaki, Masahiro; Hashimoto, Masahiro; Shiomi, Eisuke; Kuribayashi, Sachio; Abe, Takayuki; Ogawa, Kenji

    2013-01-01

    To compare the diagnostic performance of tomosynthesis with that of chest radiography for the detection of pulmonary emphysema, using multidetector computed tomography (MDCT) as reference. Forty-eight patients with and 63 without pulmonary emphysema underwent chest MDCT, tomosynthesis and radiography on the same day. Two blinded radiologists independently evaluated the tomosynthesis images and radiographs for the presence of pulmonary emphysema. Axial and coronal MDCT images served as the reference standard and the percentage lung volume with attenuation values of -950 HU or lower (LAA -950 ) was evaluated to determine the extent of emphysema. Receiver-operating characteristic (ROC) analysis and generalised estimating equations model were used. ROC analysis revealed significantly better performance (P -950 . The diagnostic performance of tomosynthesis was significantly superior to that of radiography for the detection of pulmonary emphysema. In both tomosynthesis and radiography, the sensitivity was affected by the LAA -950 . (orig.)

  2. Emergency CT brain: preliminary interpretation with a tablet device: image quality and diagnostic performance of the Apple iPad.

    LENUS (Irish Health Repository)

    Mc Laughlin, Patrick

    2012-04-01

    Tablet devices have recently been used in radiological image interpretation because they have a display resolution comparable to desktop LCD monitors. We identified a need to examine tablet display performance prior to their use in preliminary interpretation of radiological images. We compared the spatial and contrast resolution of a commercially available tablet display with a diagnostic grade 2 megapixel monochrome LCD using a contrast detail phantom. We also recorded reporting discrepancies, using the ACR RADPEER system, between preliminary interpretation of 100 emergency CT brain examinations on the tablet display and formal review on a diagnostic LCD. The iPad display performed inferiorly to the diagnostic monochrome display without the ability to zoom. When the software zoom function was enabled on the tablet device, comparable contrast detail phantom scores of 163 vs 165 points were achieved. No reporting discrepancies were encountered during the interpretation of 43 normal examinations and five cases of acute intracranial hemorrhage. There were seven RADPEER2 (understandable) misses when using the iPad display and 12 with the diagnostic LCD. Use of software zoom in the tablet device improved its contrast detail phantom score. The tablet allowed satisfactory identification of acute CT brain findings, but additional research will be required to examine the cause of "understandable" reporting discrepancies that occur when using tablet devices.

  3. Diagnostic Performance of Three Phase Bone Scan for Complex Regional Pain Syndrome Type 1 with Optimally Modified Image Criteria

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Hyun Woo; Paeng, Jin Chul; Nahm, Francins Sahngun; Kim, Seog Gyun; Zehra, Tanzeel; Oh, So Won; Lee, Hyo Sang; Kang, Keon Wook; Chung, June Key; Lee, Myung Chul; Lee, Dong Soo [Seoul National Univ. College of Medicine, Seoul (Korea, Republic of)

    2011-12-15

    Although the three phase bone scan (TBPS) is one of the widely used imaging studies for diagnosing complex regional pain syndrome type 1 (CRPS 1), there is some controversy regarding the TPBS image criteria for CRPS 1. In this study, we modified the image criteria using image pattern and quantitative analysis in the patients diagnosed using the most recent consensus clinical diagnostic criteria. The study included 140 patients with suspected CRPS 1 (CRPS 1, n=79; non CRPS, n=61; mean age 39{+-}15 years) who underwent TPBS. The clinical diagnostic criteria for CRPS 1 revised by the Budapest consensus group were used for confirmative diagnosis. Patients were classified according to flow/pool and delayed uptake (DU) image patterns, and the time interval between the initiating event and TPBS (TI{sup eventscan)}. Quantitative analysis for lesion to contralateral ratio (LCR) was performed. Modified TPBS image criteria were created and evaluated for optimal diagnostic performance. Both increased and decreased periarticular DU were significant image findings for CRPS 1 (CRPS 1 positive rate=73% in the increased DU group, 75% in the decreased DU group). The TI{sup eventscand}id not differ significantly between the different image pattern groups. Quantitative analysis revealed an LCR of 1.43 was the optimal cutoff value for CRPS 1 and diagnostic performance was significantly improved in the increased DU group (area under the curve=0.732). Given the modified image criteria, the sensitivity and specificity of TPBS for diagnosing CRPS 1 were 80% and 72%, respectively. Optimally modified TPBS image criteria for CRPS 1 were suggested using image pattern and quantitative analysis. With the criteria, TPBS is an effective imaging study for CRPS 1 even with the most recent consensus clinical diagnostic criteria.

  4. Diagnostic Performance of Three Phase Bone Scan for Complex Regional Pain Syndrome Type 1 with Optimally Modified Image Criteria

    International Nuclear Information System (INIS)

    Kwon, Hyun Woo; Paeng, Jin Chul; Nahm, Francins Sahngun; Kim, Seog Gyun; Zehra, Tanzeel; Oh, So Won; Lee, Hyo Sang; Kang, Keon Wook; Chung, June Key; Lee, Myung Chul; Lee, Dong Soo

    2011-01-01

    Although the three phase bone scan (TBPS) is one of the widely used imaging studies for diagnosing complex regional pain syndrome type 1 (CRPS 1), there is some controversy regarding the TPBS image criteria for CRPS 1. In this study, we modified the image criteria using image pattern and quantitative analysis in the patients diagnosed using the most recent consensus clinical diagnostic criteria. The study included 140 patients with suspected CRPS 1 (CRPS 1, n=79; non CRPS, n=61; mean age 39±15 years) who underwent TPBS. The clinical diagnostic criteria for CRPS 1 revised by the Budapest consensus group were used for confirmative diagnosis. Patients were classified according to flow/pool and delayed uptake (DU) image patterns, and the time interval between the initiating event and TPBS (TI eventscan) . Quantitative analysis for lesion to contralateral ratio (LCR) was performed. Modified TPBS image criteria were created and evaluated for optimal diagnostic performance. Both increased and decreased periarticular DU were significant image findings for CRPS 1 (CRPS 1 positive rate=73% in the increased DU group, 75% in the decreased DU group). The TI eventscand id not differ significantly between the different image pattern groups. Quantitative analysis revealed an LCR of 1.43 was the optimal cutoff value for CRPS 1 and diagnostic performance was significantly improved in the increased DU group (area under the curve=0.732). Given the modified image criteria, the sensitivity and specificity of TPBS for diagnosing CRPS 1 were 80% and 72%, respectively. Optimally modified TPBS image criteria for CRPS 1 were suggested using image pattern and quantitative analysis. With the criteria, TPBS is an effective imaging study for CRPS 1 even with the most recent consensus clinical diagnostic criteria.

  5. Comparative analysis of diagnostic performance, feasibility and cost of different test-methods for thyroid nodules with indeterminate cytology.

    Science.gov (United States)

    Sciacchitano, Salvatore; Lavra, Luca; Ulivieri, Alessandra; Magi, Fiorenza; De Francesco, Gian Paolo; Bellotti, Carlo; Salehi, Leila B; Trovato, Maria; Drago, Carlo; Bartolazzi, Armando

    2017-07-25

    Since it is impossible to recognize malignancy at fine needle aspiration (FNA) cytology in indeterminate thyroid nodules, surgery is recommended for all of them. However, cancer rate at final histology is blood assay.We performed systematic reviews and meta-analyses to compare their features, feasibility, diagnostic performance and cost. GEC, GEC+BRAF, M/F panel+miRNA GEC and M/F panel by NGS were the best in ruling-out malignancy (sensitivity = 90%, 89%, 89% and 90% respectively). BRAF and M/F panel alone and by NGS were the best in ruling-in malignancy (specificity = 100%, 93% and 93%). The M/F by NGS showed the highest accuracy (92%) and BRAF the highest diagnostic odds ratio (DOR) (247). GAL-3-ICC performed well as rule-out (sensitivity = 83%) and rule-in test (specificity = 85%), with good accuracy (84%) and high DOR (27) and is one of the cheapest (113 USD) and easiest one to be performed in different clinical settings.In conclusion, the more accurate molecular-based test-methods are still expensive and restricted to few, highly specialized and centralized laboratories. GAL-3-ICC, although limited by some false negatives, represents the most suitable screening test-method to be applied on a large-scale basis in the diagnostic algorithm of indeterminate thyroid lesions.

  6. An Onboard ISS Virtual Reality Trainer

    Science.gov (United States)

    Miralles, Evelyn

    2013-01-01

    Prior to the retirement of the Space Shuttle, many exterior repairs on the International Space Station (ISS) were carried out by shuttle astronauts, trained on the ground and flown to the Station to perform these specific repairs. With the retirement of the shuttle, this is no longer an available option. As such, the need for ISS crew members to review scenarios while on flight, either for tasks they already trained for on the ground or for contingency operations has become a very critical issue. NASA astronauts prepare for Extra-Vehicular Activities (EVA) or Spacewalks through numerous training media, such as: self-study, part task training, underwater training in the Neutral Buoyancy Laboratory (NBL), hands-on hardware reviews and training at the Virtual Reality Laboratory (VRLab). In many situations, the time between the last session of a training and an EVA task might be 6 to 8 months. EVA tasks are critical for a mission and as time passes the crew members may lose proficiency on previously trained tasks and their options to refresh or learn a new skill while on flight are limited to reading training materials and watching videos. In addition, there is an increased need for unplanned contingency repairs to fix problems arising as the Station ages. In order to help the ISS crew members maintain EVA proficiency or train for contingency repairs during their mission, the Johnson Space Center's VRLab designed an immersive ISS Virtual Reality Trainer (VRT). The VRT incorporates a unique optical system that makes use of the already successful Dynamic On-board Ubiquitous Graphics (DOUG) software to assist crew members with procedure reviews and contingency EVAs while on board the Station. The need to train and re-train crew members for EVAs and contingency scenarios is crucial and extremely demanding. ISS crew members are now asked to perform EVA tasks for which they have not been trained and potentially have never seen before. The Virtual Reality Trainer (VRT

  7. Appraising and applying evidence about a diagnostic test during a performance-based assessment

    Directory of Open Access Journals (Sweden)

    Franklin Ellen

    2004-10-01

    Full Text Available Abstract Background The practice of Evidence-based Medicine requires that clinicians assess the validity of published research and then apply the results to patient care. We wanted to assess whether our soon-to-graduate medical students could appraise and apply research about a diagnostic test within a clinical context and to compare our students with peers trained at other institutions. Methods 4th year medical students who previously had demonstrated competency at probability revision and just starting first-year Internal Medicine residents were used for this research. Following an encounter with a simulated patient, subjects critically appraised a paper about an applicable diagnostic test and revised the patient's pretest probability given the test result. Results The medical students and residents demonstrated similar skills at critical appraisal, correctly answering 4.7 and 4.9, respectively, of 6 questions (p = 0.67. Only one out of 28 (3% medical students and none of the 15 residents were able to correctly complete the probability revision task (p = 1.00. Conclusions This study found that most students completing medical school are able to appraise an article about a diagnostic test but few are able to apply the information from the article to a patient. These findings raise questions about the clinical usefulness of the EBM skills possessed by graduating medical students within the area of diagnostic testing.

  8. Performance study of the primary standard ionization chamber for deployment of the diagnostic radiology qualities

    International Nuclear Information System (INIS)

    Cardoso, Ricardo de Souza; Bossio, Francisco; Quaresma, Daniel da Silva; Peixoto, Jose Guilherme Pereira

    2013-01-01

    Activities radiotherapy, diagnostic radiology and radiation protection, require knowledge of physical and dosimetric parameters, to be applied safely. Aiming to meet demand in Brazil, the National Laboratory of Metrology of Ionising Radiation - LNMRI - is deploying the primary standard for the calibration of secondary standard chambers, used in quality control in hospitals, clinics and industries. (author)

  9. 78 FR 18988 - Establishing the Performance Characteristics of In Vitro Diagnostic Devices for the Detection of...

    Science.gov (United States)

    2013-03-28

    ... either electronic or written comments on this guidance at any time. General comments on Agency guidance... INFORMATION section for information on electronic access to the guidance. Submit electronic comments on the... diagnostic devices for the detection of antibodies to B. burgdorferi in human serum, plasma, and blood. These...

  10. Diagnostic performance of I-123-labeled serum amyloid P component scintigraphy in patients with amyloidosis

    NARCIS (Netherlands)

    Hazenberg, BPC; van Rijswijk, MH; Piers, DA; Lub-de Hooge, MN; Vellenga, E; Haagsma, EB; Hawkins, PN; Jager, PL

    Purpose: To assess the diagnostic accuracy and additional information provided by I-123-labeled serum amyloid P component ( SAP) scintigraphy in patients with systemic and localized amyloidosis. Subjects and Methods: I-123-labeled human SAP was injected intravenously into 20 controls and 189

  11. Agreement and Diagnostic Performance of FITNESSGRAM®, International Obesity Task Force, and Hungarian National BMI Standards

    Science.gov (United States)

    Laurson, Kelly R.; Welk, Gregory J.; Marton, Orsolya; Kaj, Mónika; Csányi, Tamás

    2015-01-01

    Purpose: This study examined agreement between all 3 standards (as well as relative diagnostic associations with metabolic syndrome) using a representative sample of youth from the Hungarian National Youth Fitness Study. Method: Body mass index (BMI) was assessed in a field sample of 2,352 adolescents (ages 10-18.5 years) and metabolic syndrome…

  12. Svelte Integrated Delivery System Performance Examined Through Diagnostic Catheter Delivery : The SPEED Registry

    NARCIS (Netherlands)

    Khattab, Ahmed A.; Nijhoff, Freek; Schofer, Joachim; Berland, Jacques; Meier, Bernhard; Nietlispach, Fabian; Agostoni, Pierfrancesco; Brucks, Steffen; Stella, Pieter

    2015-01-01

    Aims: The multi-center SPEED registry evaluated the procedural success and in-hospital clinical outcomes of direct stenting with the Svelte 'all-in-one' coronary stent Integrated Delivery System (IDS) through diagnostic catheters to identify the clinical indications for which this approach is

  13. Performance of different diagnostic criteria of overweight and obesity as predictors of metabolic syndrome in adolescents

    Directory of Open Access Journals (Sweden)

    Raphael Gonçalves de Oliveira

    2017-09-01

    Conclusions: Overweight and obesity using BMI showed a moderate association with MetS, regardless of the diagnostic criteria used. However, the IOTF criterion showed better predictive capacity for the presence of MetS than the WHO and the Conde and Monteiro criteria.

  14. Diagnostic model for assessing traceability system performance in fish processing plants

    NARCIS (Netherlands)

    Mgonja, J.T.; Luning, P.A.; Vorst, van der J.G.A.J.

    2013-01-01

    This paper introduces a diagnostic tool that can be used by fish processing companies to evaluate their own traceability systems in a systematic manner. The paper begins with discussions on the rationale of traceability systems in food manufacturing companies, followed by a detailed analysis of the

  15. A study on the real-time reliability of on-board equipment of train control system

    Science.gov (United States)

    Zhang, Yong; Li, Shiwei

    2018-05-01

    Real-time reliability evaluation is conducive to establishing a condition based maintenance system for the purpose of guaranteeing continuous train operation. According to the inherent characteristics of the on-board equipment, the connotation of reliability evaluation of on-board equipment is defined and the evaluation index of real-time reliability is provided in this paper. From the perspective of methodology and practical application, the real-time reliability of the on-board equipment is discussed in detail, and the method of evaluating the realtime reliability of on-board equipment at component level based on Hidden Markov Model (HMM) is proposed. In this method the performance degradation data is used directly to realize the accurate perception of the hidden state transition process of on-board equipment, which can achieve a better description of the real-time reliability of the equipment.

  16. On-board image compression for the RAE lunar mission

    Science.gov (United States)

    Miller, W. H.; Lynch, T. J.

    1976-01-01

    The requirements, design, implementation, and flight performance of an on-board image compression system for the lunar orbiting Radio Astronomy Explorer-2 (RAE-2) spacecraft are described. The image to be compressed is a panoramic camera view of the long radio astronomy antenna booms used for gravity-gradient stabilization of the spacecraft. A compression ratio of 32 to 1 is obtained by a combination of scan line skipping and adaptive run-length coding. The compressed imagery data are convolutionally encoded for error protection. This image compression system occupies about 1000 cu cm and consumes 0.4 W.

  17. Performance of a real-time PCR assay in routine bovine mastitis diagnostics compared with in-depth conventional culture.

    Science.gov (United States)

    Hiitiö, Heidi; Riva, Rauna; Autio, Tiina; Pohjanvirta, Tarja; Holopainen, Jani; Pyörälä, Satu; Pelkonen, Sinikka

    2015-05-01

    Reliable identification of the aetiological agent is crucial in mastitis diagnostics. Real-time PCR is a fast, automated tool for detecting the most common udder pathogens directly from milk. In this study aseptically taken quarter milk samples were analysed with a real-time PCR assay (Thermo Scientific PathoProof Mastitis Complete-12 Kit, Thermo Fisher Scientific Ltd.) and by semi-quantitative, in-depth bacteriological culture (BC). The aim of the study was to evaluate the diagnostic performance of the real-time PCR assay in routine use. A total of 294 quarter milk samples from routine mastitis cases were cultured in the national reference laboratory of Finland and examined with real-time PCR. With BC, 251 out of 294 (85.7%) of the milk samples had at least one colony on the plate and 38 samples were considered contaminated. In the PCR mastitis assay, DNA of target species was amplified in 244 samples out of 294 (83.0%). The most common bacterial species detected in the samples, irrespective of the diagnostic method, was the coagulase negative staphylococci (CNS) group (later referred as Staphylococcus spp.) followed by Staphylococcus aureus. Sensitivity (Se) and specificity (Sp) for the PCR assay to provide a positive Staph. aureus result was 97.0 and 95.8% compared with BC. For Staphylococcus spp., the corresponding figures were 86.7 and 75.4%. Our results imply that PCR performed well as a diagnostic tool to detect Staph. aureus but may be too nonspecific for Staphylococcus spp. in routine use with the current cut-off Ct value (37.0). Using PCR as the only microbiological method for mastitis diagnostics, clinical relevance of the results should be carefully considered before further decisions, for instance antimicrobial treatment, especially when minor pathogens with low amount of DNA have been detected. Introducing the concept of contaminated samples should also be considered.

  18. Diagnostic performance of combined noninvasive coronary angiography and myocardial perfusion imaging using 320 row detector computed tomography

    DEFF Research Database (Denmark)

    Vavere, Andrea L; Simon, Gregory G; George, Richard T

    2013-01-01

    Multidetector coronary computed tomography angiography (CTA) is a promising modality for widespread clinical application because of its noninvasive nature and high diagnostic accuracy as found in previous studies using 64 to 320 simultaneous detector rows. It is, however, limited in its ability...... to detect myocardial ischemia. In this article, we describe the design of the CORE320 study ("Combined coronary atherosclerosis and myocardial perfusion evaluation using 320 detector row computed tomography"). This prospective, multicenter, multinational study is unique in that it is designed to assess...... the diagnostic performance of combined 320-row CTA and myocardial CT perfusion imaging (CTP) in comparison with the combination of invasive coronary angiography and single-photon emission computed tomography myocardial perfusion imaging (SPECT-MPI). The trial is being performed at 16 medical centers located in 8...

  19. Molecular diagnosis of bacterial vaginosis: Does adjustment for total bacterial load or human cellular content improve diagnostic performance?

    Science.gov (United States)

    Plummer, E L; Garland, S M; Bradshaw, C S; Law, M G; Vodstrcil, L A; Hocking, J S; Fairley, C K; Tabrizi, S N

    2017-02-01

    We investigated the utility of quantitative PCR assays for diagnosis of bacterial vaginosis and found that while the best model utilized bacterial copy number adjusted for total bacterial load (sensitivity=98%, specificity=93%, AUC=0.95[95%CI=0.93,0.97]), adjusting for total bacterial or human cell load did not consistently increase the diagnostic performance of the assays. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Virtual Resting Pd/Pa From Coronary Angiography and Blood Flow Modelling: Diagnostic Performance Against Fractional Flow Reserve.

    Science.gov (United States)

    Papafaklis, Michail I; Muramatsu, Takashi; Ishibashi, Yuki; Bourantas, Christos V; Fotiadis, Dimitrios I; Brilakis, Emmanouil S; Garcia-Garcia, Héctor M; Escaned, Javier; Serruys, Patrick W; Michalis, Lampros K

    2018-03-01

    Fractional flow reserve (FFR) has been established as a useful diagnostic tool. The distal coronary pressure to aortic pressure (Pd/Pa) ratio at rest is a simpler physiologic index but also requires the use of the pressure wire, whereas recently proposed virtual functional indices derived from coronary imaging require complex blood flow modelling and/or are time-consuming. Our aim was to test the diagnostic performance of virtual resting Pd/Pa using routine angiographic images and a simple flow model. Three-dimensional quantitative coronary angiography (3D-QCA) was performed in 139 vessels (120 patients) with intermediate lesions assessed by FFR. The resting Pd/Pa for each lesion was assessed by computational fluid dynamics. The discriminatory power of virtual resting Pd/Pa against FFR (reference: ≤0.80) was high (area under the receiver operator characteristic curve [AUC]: 90.5% [95% CI: 85.4-95.6%]). Diagnostic accuracy, sensitivity and specificity for the optimal virtual resting Pd/Pa cut-off (≤0.94) were 84.9%, 90.4% and 81.6%, respectively. Virtual resting Pd/Pa demonstrated superior performance (pvirtual resting Pd/Pa and FFR (r=0.69, pVirtual resting Pd/Pa using routine angiographic data and a simple flow model provides fast functional assessment of coronary lesions without requiring the pressure-wire and hyperaemia induction. The high diagnostic performance of virtual resting Pd/Pa for predicting FFR shows promise for using this simple/fast virtual index in clinical practice. Copyright © 2017 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.

  1. Prevalence and diagnostic performance of computed tomography angiography spot sign for intracerebral hematoma expansion depend on scan timing

    Energy Technology Data Exchange (ETDEWEB)

    Tsukabe, Akio; Watanabe, Yoshiyuki; Tanaka, Hisashi; Kunitomi, Yuki; Nishizawa, Mitsuo; Arisawa, Atsuko; Tomiyama, Noriyuki [Osaka University Graduate School of Medicine, Department of Diagnostic and Interventional Radiology, Suita, Osaka (Japan); Yoshiya, Kazuhisa; Shimazu, Takeshi [Osaka University Graduate School of Medicine, Department of Traumatology and Acute Critical Medicine, Suita, Osaka (Japan)

    2014-12-15

    The computed tomography angiography (CTA) spot sign correlates with intracerebral hemorrhage (ICH) expansion; however, various diagnostic performances for hematoma expansion, especially in sensitivity, have been reported. We aimed to assess the impact of scan timing of CTA on the diagnostic performance of the CTA spot sign for ICH expansion in two different arterial phases within patients. Eighty-three consecutive patients with primary ICH who received two sequential CTAs were recruited. Two neuroradiologists reviewed CTAs for CTA spot signs, while one reviewed initial and follow-up non-contrast CT for measuring ICH volume. The time interval between two phases was then calculated, and the diagnostic performance of CTA spot sign in each phase was evaluated. CTA spot signs were observed in 20/83 (24.1 %) patients in the early phase and 44/83 (53.0 %) patients in the late phase. The mean time interval between the two phases was 12.7 s. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for hematoma progression of CTA spot sign were 48.1, 87.5, 65.0, 77.8, and 74.7 %, respectively, in early phase and 92.6, 66.1, 56.8, 94.9, and 74.7 %, respectively, in late phase. The CTA spot sign was significantly associated with ICH expansion in early (P < 0.001) and late (P < 0.00001) phases (Pearson's chi-square test). A mere 10-s difference in scan timing could make a difference on prevalence and diagnostic performance of the CTA spot sign, suggesting a need for the standardization of the CTA protocol to generalize the approach for effective clinical application. (orig.)

  2. Performance of the Quidel Sofia Rapid Influenza Diagnostic Test During the 2012-2013 and 2013-2014 Influenza Seasons

    Science.gov (United States)

    2016-03-23

    Performance of the Quidel Sofia rapid influenza diagnostic test during the 2012–2013 and 2013–2014 influenza seasons Peter E. Kammerer, Jennifer M... Influenza A+B Fluorescent Immunoassay was used to test nasal swab specimens from patients with influenza -like illness at US–Mexico border-area clinics in...the 2012–2013 and 2013–2014 influenza seasons. Compared with real-time reverse transcription polymerase chain reaction, the overall sensitivities and

  3. Diagnostic performance and useful findings of ultrasound re-evaluation for patients with equivocal CT features of acute appendicitis.

    Science.gov (United States)

    Kim, Mi Sung; Kwon, Heon-Ju; Kang, Kyung A; Do, In-Gu; Park, Hee-Jin; Kim, Eun Young; Hong, Hyun Pyo; Choi, Yoon Jung; Kim, Young Hwan

    2018-02-01

    To evaluate the diagnostic performance of ultrasound and to determine which ultrasound findings are useful to differentiate appendicitis from non-appendicitis in patients who underwent ultrasound re-evaluation owing to equivocal CT features of acute appendicitis. 62 patients who underwent CT examinations for suspected appendicitis followed by ultrasound re-evaluation owing to equivocal CT findings were included. Equivocal CT findings were considered based on the presence of only one or two findings among the CT criteria, and ultrasound re-evaluation was done based on a predefined structured report form. The diagnostic performance of ultrasound and independent variables to discriminate appendicitis from non-appendicitis were assessed. There were 27 patients in the appendicitis group. The overall diagnostic performance of ultrasound re-evaluation was sensitivity of 96.3%, specificity of 91.2% and accuracy of 91.9%. In terms of the performance of individual ultrasound findings, probe-induced tenderness showed the highest accuracy (86.7%) with sensitivity of 74% and specificity of 97%, followed by non-compressibility (accuracy 71.7%, sensitivity 85.2% and specificity 60.6%). The independent ultrasound findings for discriminating appendicitis were non-compressibility (p = 0.002) and increased flow on the appendiceal wall (p = 0.001). Ultrasound re-evaluation can be used to improve diagnostic accuracy in cases with equivocal CT features for diagnosing appendicitis. The presence of non-compressibility and increased vascular flow on the appendix wall are useful ultrasound findings to discriminate appendicitis from non-appendicitis. Advances in knowledge: Ultrasound re-evaluation is useful to discriminate appendicitis from non-appendicitis when CT features are inconclusive.

  4. Diagnostic performance of calcification-suppressed coronary CT angiography using rapid kilovolt-switching dual-energy CT

    Energy Technology Data Exchange (ETDEWEB)

    Yunaga, Hiroto; Ohta, Yasutoshi; Kitao, Shinichiro; Ogawa, Toshihide [Tottori University, Division of Radiology, Department of Pathophysiological Therapeutic Science, Faculty of Medicine, Yonago City, Tottori (Japan); Kaetsu, Yasuhiro [Kakogawa Higashi Hospital, Department of Cardiology, Kakogawa (Japan); Watanabe, Tomomi; Furuse, Yoshiyuki; Yamamoto, Kazuhiro [Tottori University, Division of Cardiology, Department of Molecular Medicine and Therapeutics, Faculty of Medicine, Yonago (Japan)

    2017-07-15

    Multi-detector-row computed tomography angiography (MDCTA) plays an important role in the assessment of patients with suspected coronary artery disease. However, MDCTA tends to overestimate stenosis in calcified coronary artery lesions. The aim of our study was to evaluate the diagnostic performance of calcification-suppressed material density (MD) images produced by using a single-detector single-source dual-energy computed tomography (ssDECT). We enrolled 67 patients with suspected or known coronary artery disease who underwent ssDECT with rapid kilovolt-switching (80 and 140 kVp). Coronary artery stenosis was evaluated on the basis of MD images and virtual monochromatic (VM) images. The diagnostic performance of the two methods for detecting coronary artery disease was compared with that of invasive coronary angiography as a reference standard. We evaluated 239 calcified segments. In all the segments, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy for detecting significant stenosis were respectively 88%, 88%, 75%, 95% and 88% for the MD images, 91%, 71%, 56%, 95% and 77% for the VM images. PPV was significantly higher on the MD images than on the VM images (P < 0.0001). Calcification-suppressed MD images improved PPV and diagnostic performance for calcified coronary artery lesions. (orig.)

  5. Comparison of Diagnostic Performance of Semi-Quantitative Knee Ultrasound and Knee Radiography with MRI: Oulu Knee Osteoarthritis Study

    Science.gov (United States)

    Podlipská, Jana; Guermazi, Ali; Lehenkari, Petri; Niinimäki, Jaakko; Roemer, Frank W.; Arokoski, Jari P.; Kaukinen, Päivi; Liukkonen, Esa; Lammentausta, Eveliina; Nieminen, Miika T.; Tervonen, Osmo; Koski, Juhani M.; Saarakkala, Simo

    2016-01-01

    Osteoarthritis (OA) is a common degenerative musculoskeletal disease highly prevalent in aging societies worldwide. Traditionally, knee OA is diagnosed using conventional radiography. However, structural changes of articular cartilage or menisci cannot be directly evaluated using this method. On the other hand, ultrasound is a promising tool able to provide direct information on soft tissue degeneration. The aim of our study was to systematically determine the site-specific diagnostic performance of semi-quantitative ultrasound grading of knee femoral articular cartilage, osteophytes and meniscal extrusion, and of radiographic assessment of joint space narrowing and osteophytes, using MRI as a reference standard. Eighty asymptomatic and 79 symptomatic subjects with mean age of 57.7 years were included in the study. Ultrasound performed best in the assessment of femoral medial and lateral osteophytes, and medial meniscal extrusion. In comparison to radiography, ultrasound performed better or at least equally well in identification of tibio-femoral osteophytes, medial meniscal extrusion and medial femoral cartilage morphological degeneration. Ultrasound provides relevant additional diagnostic information on tissue-specific morphological changes not depicted by conventional radiography. Consequently, the use of ultrasound as a complementary imaging tool along with radiography may enable more accurate and cost-effective diagnostics of knee osteoarthritis at the primary healthcare level. PMID:26926836

  6. Diagnostic performance of qualitative shear-wave elastography according to different color map opacities for breast masses.

    Science.gov (United States)

    Kim, Hana; Youk, Ji Hyun; Gweon, Hye Mi; Kim, Jeong-Ah; Son, Eun Ju

    2013-08-01

    To compare the diagnostic performance of qualitative shear-wave elastography (SWE) according to three different color map opacities for breast masses 101 patients aged 21-77 years with 113 breast masses underwent B-mode US and SWE under three different color map opacities (50%, 19% and 100%) before biopsy or surgery. Following SWE features were reviewed: visual pattern classification (pattern 1-4), color homogeneity (Ehomo) and six-point color score of maximum elasticity (Ecol). Combined with B-mode US and SWE, the likelihood of malignancy (LOM) was also scored. The area under the curve (AUC) was obtained by ROC curve analysis to assess the diagnostic performance under each color opacity. A visual color pattern, Ehomo, Ecol and LOM scoring were significantly different between benign and malignant lesions under all color opacities (Pbreast lesion under all color opacities. The difference in color map opacity did not significantly influence diagnostic performance of SWE. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  7. Fresh water generators onboard a floating platform

    International Nuclear Information System (INIS)

    Tewari, P.K.; Verma, R.K.; Misra, B.M.; Sadhulkan, H.K.

    1997-01-01

    A dependable supply of fresh water is essential for any ocean going vessel. The operating and maintenance personnel on offshore platforms and marine structures also require a constant and regular supply of fresh water to meet their essential daily needs. A seawater thermal desalination unit onboard delivers good quality fresh water from seawater. The desalination units developed by Bhabha Atomic Research Centre (BARC) suitable for ocean going vessels and offshore platforms have been discussed. Design considerations of such units with reference to floating platforms and corrosive environments have been presented. The feasibility of coupling a low temperature vacuum evaporation (LTVE) desalination plant suitable for an onboard floating platform to a PHWR nuclear power plant has also been discussed. (author). 1 ref., 3 figs, 2 tabs

  8. On-boarding the Middle Manager.

    Science.gov (United States)

    OʼConnor, Mary

    The trend of promoting clinical experts into management roles continues. New middle managers need a transitional plan that includes support, mentoring, and direction from senior leaders, including the chief nursing officer (CNO). This case study demonstrates how the CNO of one organization collaborated with a faculty member colleague to develop and implement a yearlong personalized on-boarding program for a group of new nurse middle managers.

  9. The AGILE on-board Kalman filter

    International Nuclear Information System (INIS)

    Giuliani, A.; Cocco, V.; Mereghetti, S.; Pittori, C.; Tavani, M.

    2006-01-01

    On-board reduction of particle background is one of the main challenges of space instruments dedicated to gamma-ray astrophysics. We present in this paper a discussion of the method and main simulation results of the on-board background filter of the Gamma-Ray Imaging Detector (GRID) of the AGILE mission. The GRID is capable of detecting and imaging with optimal point spread function gamma-ray photons in the range 30MeV-30GeV. The AGILE planned orbit is equatorial, with an altitude of 550km. This is an optimal orbit from the point of view of the expected particle background. For this orbit, electrons and positrons of kinetic energies between 20MeV and hundreds of MeV dominate the particle background, with significant contributions from high-energy (primary) and low-energy protons, and gamma-ray albedo-photons. We present here the main results obtained by extensive simulations of the on-board AGILE-GRID particle/photon background rejection algorithms based on a special application of Kalman filter techniques. This filter is applied (Level-2) sequentially after other data processing techniques characterizing the Level-1 processing. We show that, in conjunction with the Level-1 processing, the adopted Kalman filtering is expected to reduce the total particle/albedo-photon background rate to a value (=<10-30Hz) that is compatible with the AGILE telemetry. The AGILE on-board Kalman filter is also effective in reducing the Earth-albedo-photon background rate, and therefore contributes to substantially increase the AGILE exposure for celestial gamma-ray sources

  10. Building Performance Optimization while Empowering Occupants Toward Environmentally Sustainable Behavior through Continuous Monitoring and Diagnostics

    Science.gov (United States)

    2016-12-01

    Federal Energy Management Program FM Facility Manager GHG Green House Gases HASP Health and Safety Plan HVAC Heating Ventilation and... workplace energy efficiency enhancement by the DOD personnel. 2.1.2 ID-F Intelligent Dashboards for Facility Managers Creation of the Base Building...demonstration project. The first technology, ‘ID-F,’ targets building facility managers and allows real time diagnostics for BAS systems with features

  11. The development, evaluation and performance of molecular diagnostics for detection of Mycobacterium tuberculosis.

    Science.gov (United States)

    Bates, Matthew; Zumla, Alimuddin

    2016-01-01

    The unique pathogenesis of tuberculosis (TB) poses several barriers to the development of accurate diagnostics: a) the establishment of life-long latency by Mycobacterium tuberculosis (M.tb) after primary infection confounds the development of classical antibody or antigen based assays; b) our poor understanding of the molecular pathways that influence progression from latent to active disease; c) the intracellular nature of M.tb infection in tissues means that M.tb and/or its components, are not readily detectable in peripheral specimens; and d) the variable presence of M.tb bacilli in specimens from patients with extrapulmonary TB or children. The literature on the current portfolio of molecular diagnostics tests for TB is reviewed here and the developmental pipeline is summarized. Also reviewed are data from recently published operational research on the GeneXpert MTB/RIF assay and discussed are the lessons that can be taken forward for the design of studies to evaluate the impact of TB diagnostics.

  12. Diagnostic Performance of Bronchoalveolar Lavage Fluid CD4/CD8 Ratio for Sarcoidosis: A Meta-analysis.

    Science.gov (United States)

    Shen, Yongchun; Pang, Caishuang; Wu, Yanqiu; Li, Diandian; Wan, Chun; Liao, Zenglin; Yang, Ting; Chen, Lei; Wen, Fuqiang

    2016-06-01

    The usefulness of bronchoalveolar lavage fluid (BALF) CD4/CD8 ratio for diagnosing sarcoidosis has been reported in many studies with variable results. Therefore, we performed a meta-analysis to estimate the overall diagnostic accuracy of BALF CD4/CD8 ratio based on the bulk of published evidence. Studies published prior to June 2015 and indexed in PubMed, OVID, Web of Science, Scopus and other databases were evaluated for inclusion. Data on sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), and diagnostic odds ratio (DOR) were pooled from included studies. Summary receiver operating characteristic (SROC) curves were used to summarize overall test performance. Deeks's funnel plot was used to detect publication bias. Sixteen publications with 1885 subjects met our inclusion criteria and were included in this meta-analysis. Summary estimates of the diagnostic performance of the BALF CD4/CD8 ratio were as follows: sensitivity, 0.70 (95%CI 0.64-0.75); specificity, 0.83 (95%CI 0.78-0.86); PLR, 4.04 (95%CI 3.13-5.20); NLR, 0.36 (95%CI 0.30-0.44); and DOR, 11.17 (95%CI 7.31-17.07). The area under the SROC curve was 0.84 (95%CI 0.81-0.87). There was no evidence of publication bias. Measuring the BALF CD4/CD8 ratio may assist in the diagnosis of sarcoidosis when interpreted in parallel with other diagnostic factors. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  13. Utility of DWI with quantitative ADC values in ovarian tumors: a meta-analysis of diagnostic test performance.

    Science.gov (United States)

    Pi, Shan; Cao, Rong; Qiang, Jin Wei; Guo, Yan Hui

    2018-01-01

    Background Diffusion-weighted imaging (DWI) and quantitative apparent diffusion coefficient (ADC) values are widely used in the differential diagnosis of ovarian tumors. Purpose To assess the diagnostic performance of quantitative ADC values in ovarian tumors. Material and Methods PubMed, Embase, the Cochrane Library, and local databases were searched for studies assessing ovarian tumors using quantitative ADC values. We quantitatively analyzed the diagnostic performances for two clinical problems: benign vs. malignant tumors and borderline vs. malignant tumors. We evaluated diagnostic performances by the pooled sensitivity and specificity values and by summary receiver operating characteristic (SROC) curves. Subgroup analyses were used to analyze study heterogeneity. Results From the 742 studies identified in the search results, 16 studies met our inclusion criteria. A total of ten studies evaluated malignant vs. benign ovarian tumors and six studies assessed malignant vs. borderline ovarian tumors. Regarding the diagnostic accuracy of quantitative ADC values for distinguishing between malignant and benign ovarian tumors, the pooled sensitivity and specificity values were 0.91 and 0.91, respectively. The area under the SROC curve (AUC) was 0.96. For differentiating borderline from malignant tumors, the pooled sensitivity and specificity values were 0.89 and 0.79, and the AUC was 0.91. The methodological quality of the included studies was moderate. Conclusion Quantitative ADC values could serve as useful preoperative markers for predicting the nature of ovarian tumors. Nevertheless, prospective trials focused on standardized imaging parameters are needed to evaluate the clinical value of quantitative ADC values in ovarian tumors.

  14. Performance Measures of Diagnostic Codes for Detecting Opioid Overdose in the Emergency Department.

    Science.gov (United States)

    Rowe, Christopher; Vittinghoff, Eric; Santos, Glenn-Milo; Behar, Emily; Turner, Caitlin; Coffin, Phillip O

    2017-04-01

    Opioid overdose mortality has tripled in the United States since 2000 and opioids are responsible for more than half of all drug overdose deaths, which reached an all-time high in 2014. Opioid overdoses resulting in death, however, represent only a small fraction of all opioid overdose events and efforts to improve surveillance of this public health problem should include tracking nonfatal overdose events. International Classification of Disease (ICD) diagnosis codes, increasingly used for the surveillance of nonfatal drug overdose events, have not been rigorously assessed for validity in capturing overdose events. The present study aimed to validate the use of ICD, 9th revision, Clinical Modification (ICD-9-CM) codes in identifying opioid overdose events in the emergency department (ED) by examining multiple performance measures, including sensitivity and specificity. Data on ED visits from January 1, 2012, to December 31, 2014, including clinical determination of whether the visit constituted an opioid overdose event, were abstracted from electronic medical records for patients prescribed long-term opioids for pain from any of six safety net primary care clinics in San Francisco, California. Combinations of ICD-9-CM codes were validated in the detection of overdose events as determined by medical chart review. Both sensitivity and specificity of different combinations of ICD-9-CM codes were calculated. Unadjusted logistic regression models with robust standard errors and accounting for clustering by patient were used to explore whether overdose ED visits with certain characteristics were more or less likely to be assigned an opioid poisoning ICD-9-CM code by the documenting physician. Forty-four (1.4%) of 3,203 ED visits among 804 patients were determined to be opioid overdose events. Opioid-poisoning ICD-9-CM codes (E850.2-E850.2, 965.00-965.09) identified overdose ED visits with a sensitivity of 25.0% (95% confidence interval [CI] = 13.6% to 37.8%) and

  15. Diagnostic performance of stress myocardial perfusion imaging for coronary artery disease: a systematic review and meta-analysis

    International Nuclear Information System (INIS)

    Jong, Marcus C. de; Genders, Tessa S.S.; Geuns, Robert-Jan van; Moelker, Adriaan; Hunink, M.G.M.

    2012-01-01

    To determine and compare the diagnostic performance of stress myocardial perfusion imaging (MPI) for the diagnosis of obstructive coronary artery disease (CAD), using conventional coronary angiography (CCA) as the reference standard. We searched Medline and Embase for literature that evaluated stress MPI for the diagnosis of obstructive CAD using magnetic resonance imaging (MRI), contrast-enhanced echocardiography (ECHO), single-photon emission computed tomography (SPECT) and positron emission tomography (PET). All pooled analyses were based on random effects models. Articles on MRI yielded a total of 2,970 patients from 28 studies, articles on ECHO yielded a sample size of 795 from 10 studies, articles on SPECT yielded 1,323 from 13 studies. For CAD defined as either at least 50 %, at least 70 % or at least 75 % lumen diameter reduction on CCA, the natural logarithms of the diagnostic odds ratio (lnDOR) for MRI (3.63; 95 % CI 3.26-4.00) was significantly higher compared to that of SPECT (2.76; 95 % CI 2.28-3.25; P = 0.006) and that of ECHO (2.83; 95 % CI 2.29-3.37; P = 0.02). There was no significant difference between the lnDOR of SPECT and ECHO (P = 0.52). Our results suggest that MRI is superior for the diagnosis of obstructive CAD compared with ECHO and SPECT. ECHO and SPECT demonstrated similar diagnostic performance. (orig.)

  16. CT-guided transthoracic core needle biopsy for small pulmonary lesions: diagnostic performance and adequacy for molecular testing.

    Science.gov (United States)

    Tian, Panwen; Wang, Ye; Li, Lei; Zhou, Yongzhao; Luo, Wenxin; Li, Weimin

    2017-02-01

    Computed tomography (CT)-guided transthoracic needle biopsy is a well-established, minimally invasive diagnostic tool for pulmonary lesions. Few large studies have been conducted on the diagnostic performance and adequacy for molecular testing of transthoracic core needle biopsy (TCNB) for small pulmonary lesions. This study included CT-guided TCNB with 18-gauge cutting needles in 560 consecutive patients with small (≤3 cm) pulmonary lesions from January 2012 to January 2015. There were 323 males and 237 females, aged 51.8±12.7 years. The size of the pulmonary lesions was 1.8±0.6 cm. The sensitivity, specificity, accuracy and complications of the biopsies were investigated. The risk factors of diagnostic failure were assessed using univariate and multivariate analyses. The sample's adequacy for molecular testing of non-small cell lung cancer (NSCLC) was analyzed. The overall sensitivity, specificity, and accuracy for diagnosis of malignancy were 92.0% (311/338), 98.6% (219/222), and 94.6% (530/560), respectively. The incidence of bleeding complications was 22.9% (128/560), and the incidence of pneumothorax was 10.4% (58/560). Logistic multivariate regression analysis showed that the independent risk factors for diagnostic failure were a lesion size ≤1 cm [odds ratio (OR), 3.95; P=0.007], lower lobe lesions (OR, 2.83; P=0.001), and pneumothorax (OR, 1.98; P=0.004). Genetic analysis was successfully performed on 95.45% (168/176) of specimens diagnosed as NSCLC. At least 96.8% of samples with two or more passes from a lesion were sufficient for molecular testing. The diagnostic yield of small pulmonary lesions by CT-guided TCNB is high, and the procedure is relatively safe. A lesion size ≤1 cm, lower lobe lesions, and pneumothorax are independent risk factors for biopsy diagnostic failure. TCNB specimens could provide adequate tissues for molecular testing.

  17. Effect of breast cancer phenotype on diagnostic performance of MRI in the prediction to response to neoadjuvant treatment

    Energy Technology Data Exchange (ETDEWEB)

    Bufi, Enida, E-mail: reagandus@alice.it [Department of Bioimaging and Radiological Sciences, Catholic University, Rome (Italy); Belli, Paolo; Di Matteo, Marialuisa [Department of Bioimaging and Radiological Sciences, Catholic University, Rome (Italy); Terribile, Daniela; Franceschini, Gianluca [Department of Surgery, Breast Unit, Catholic University, Rome (Italy); Nardone, Luigia [Department of Radiotherapy, Catholic University, Rome (Italy); Petrone, Gianluigi [Department of Pathology, Catholic University, Rome (Italy); Bonomo, Lorenzo [Department of Bioimaging and Radiological Sciences, Catholic University, Rome (Italy)

    2014-09-15

    Aim: The estimation of response to neoadjuvant chemotherapy (NAC) is useful in the surgical decision in breast cancer. We addressed the diagnostic reliability of conventional MRI, of diffusion weighted imaging (DWI) and of a merged criterion coupling morphological MRI and DWI. Diagnostic performance was analysed separately in different tumor subtypes, including HER2+ (human epidermal growth factor receptor 2)/HR+ (hormone receptor) (hybrid phenotype). Materials and methods: Two-hundred and twenty-five patients underwent MRI before and after NAC. The response to treatment was defined according to the RECIST classification and the evaluation of DWI with apparent diffusion coefficient (ADC). The complete pathological response – pCR was assessed (Mandard classification). Results: Tumor phenotypes were Luminal (63.6%), Triple Negative (16.4%), HER2+ (7.6%) or Hybrid (12.4%). After NAC, pCR was observed in 17.3% of cases. Average ADC was statistically higher after NAC (p < 0.001) among patients showing pCR vs. those who had not pCR. The RECIST classification showed adequate performance in predicting the pCR in Triple Negative (area under the receiver operating characteristic curve, ROC AUC = 0.9) and in the HER2+ subgroup (AUC = 0.826). Lower performance was found in the Luminal and Hybrid subgroups (AUC 0.693 and 0.611, respectively), where the ADC criterion yielded an improved performance (AUC = 0.787 and 0.722). The coupling of morphological and DWI criteria yielded maximally improved performance in the Luminal and Hybrid subgroups (AUC = 0.797 and 0.761). Conclusion: The diagnostic reliability of MRI in predicting the pCR to NAC depends on the tumor phenotype, particularly in the Luminal and Hybrid subgroups. In these cases, the coupling of morphological MRI evaluation and DWI assessment may facilitate the diagnosis.

  18. Diagnostic performances of shear wave elastography: which parameter to use in differential diagnosis of solid breast masses?

    Science.gov (United States)

    Lee, Eun Jung; Jung, Hae Kyoung; Ko, Kyung Hee; Lee, Jong Tae; Yoon, Jung Hyun

    2013-07-01

    To evaluate which shear wave elastography (SWE) parameter proves most accurate in the differential diagnosis of solid breast masses. One hundred and fifty-six breast lesions in 139 consecutive women (mean age: 43.54 ± 9.94 years, range 21-88 years), who had been scheduled for ultrasound-guided breast biopsy, were included. Conventional ultrasound and SWE were performed in all women before biopsy procedures. Ultrasound BI-RADS final assessment and SWE parameters were recorded. Diagnostic performance of each SWE parameter was calculated and compared with those obtained when applying cut-off values of previously published data. Performance of conventional ultrasound and ultrasound combined with each parameter was also compared. Of the 156 breast masses, 120 (76.9 %) were benign and 36 (23.1 %) malignant. Maximum stiffness (Emax) with a cut-off of 82.3 kPa had the highest area under the receiver operating characteristics curve (Az) value compared with other SWE parameters, 0.860 (sensitivity 88.9 %, specificity 77.5 %, accuracy 80.1 %). Az values of conventional ultrasound combined with each SWE parameter showed lower (but not significantly) values than with conventional ultrasound alone. Maximum stiffness (82.3 kPa) provided the best diagnostic performance. However the overall diagnostic performance of ultrasound plus SWE was not significantly better than that of conventional ultrasound alone. • SWE offers new information over and above conventional breast ultrasound • Various SWE parameters were explored regarding distinction between benign and malignant lesions • An elasticity of 82.3 kPa appears optimal in differentiating solid breast masses • However, ultrasound plus SWE was not significantly better than conventional ultrasound alone.

  19. Clinical Evaluation of Rapid Diagnostic Test Kit for Scrub Typhus with Improved Performance.

    Science.gov (United States)

    Kim, Young-Jin; Park, Sungman; Premaratna, Ranjan; Selvaraj, Stephen; Park, Sang-Jin; Kim, Sora; Kim, Donghwan; Kim, Min Soo; Shin, Dong Hoon; Choi, Kyung-Chan; Kwon, Soon-Hwan; Seo, Wonjun; Lee, Nam Taek; Kim, Seung-Han; Kang, Heui Keun; Kim, Yoon-Won

    2016-08-01

    Diagnosis of scrub typhus is challenging due to its more than twenty serotypes and the similar clinical symptoms with other acute febrile illnesses including leptospirosis, murine typhus and hemorrhagic fever with renal syndrome. Accuracy and rapidity of a diagnostic test to Orientia tsutsugamushi is an important step to diagnose this disease. To discriminate scrub typhus from other diseases, the improved ImmuneMed Scrub Typhus Rapid Diagnostic Test (RDT) was evaluated in Korea and Sri Lanka. The sensitivity at the base of each IgM and IgG indirect immunofluorescent assay (IFA) in Korean patients was 98.6% and 97.1%, and the specificity was 98.2% and 97.7% respectively. The sensitivity and specificity for retrospective diagnosis at the base of IFA in Sri Lanka was 92.1% and 96.1%. ImmuneMed RDT was not reactive to any serum from seventeen diseases including hemorrhagic fever with renal syndrome (n = 48), leptospirosis (n = 23), and murine typhus (n = 48). ImmuneMed RDT shows superior sensitivity (98.6% and 97.1%) compared with SD Bioline RDT (84.4% at IgM and 83.3% at IgG) in Korea. The retrospective diagnosis of ImmuneMed RDT exhibits 94.0% identity with enzyme-linked Immunosorbent assay (ELISA) using South India patient serum samples. These results suggest that this RDT can replace other diagnostic tests and is applicable for global diagnosis of scrub typhus. This rapid and accurate diagnosis will be beneficial for diagnosing and managing scrub typhus.

  20. Dose and diagnostic performance comparison between phase-contrast mammography with synchrotron radiation and digital mammography: a clinical study report.

    Science.gov (United States)

    Fedon, Christian; Rigon, Luigi; Arfelli, Fulvia; Dreossi, Diego; Quai, Elisa; Tonutti, Maura; Tromba, Giuliana; Cova, Maria Assunta; Longo, Renata

    2018-01-01

    Two dosimetric quantities [mean glandular dose (MGD) and entrance surface air kerma (ESAK)] and the diagnostic performance of phase-contrast mammography with synchrotron radiation (MSR) are compared to conventional digital mammography (DM). Seventy-one patients (age range, 41 to 82 years) underwent MSR after a DM examination if questionable or suspicious breast abnormalities were not clarified by ultrasonography. The MGD and the ESAK delivered in both examinations were evaluated and compared. Two on-site radiologists rated the images in consensus according to the Breast Imaging Reporting and Data System assessment categories, which were then correlated with the final diagnoses by means of statistical generalized linear models (GLMs). Receiver operating characteristic curves were also used to assess the diagnostic performance by comparing the area under the curve (AUC). An important MGD and ESAK reduction was observed in MSR due to the monoenergetic beam. In particular, an average 43% reduction was observed for the MGD and a reduction of more than 50% for the ESAK. GLM showed higher diagnostic accuracy, especially in terms of specificity, for MSR, confirmed by AUC analysis ([Formula: see text]). The study design implied that the population was characterized by a high prevalence of disease and that the radiologists, who read the DM images before referring the patient to MSR, could have been influenced in their assessments. Within these limitations, the use of synchrotron radiation with the phase-contrast technique applied to mammography showed an important dose reduction and a higher diagnostic accuracy compared with DM. These results could further encourage research on the translation of x-ray phase-contrast imaging into the clinics.

  1. [Treatment of Hallux Valgus: Current Diagnostic Testing and Surgical Treatment Performed by German Foot and Ankle Surgeons].

    Science.gov (United States)

    Arbab, Dariusch; Schneider, Lisa-Maria; Schnurr, Christoph; Bouillon, Bertil; Eysel, Peer; König, Dietmar Pierre

    2018-04-01

    Hallux valgus is one of the most prevalent foot deformities, and surgical treatment of Hallux valgus is one of the most common procedures in foot and ankle surgery. Diagnostic and treatment standards show large variation despite medical guidelines and national foot and ankle societies. The aim of this nationwide survey is a description of the current status of diagnostics and therapy of Hallux valgus in Germany. A nationwide online questionnaire survey was sent to two German foot and ankle societies. The participants were asked to answer a questionnaire of 53 questions with four subgroups (general, diagnostics, operation, preoperative management). Surgical treatment for three clinical cases demonstrating a mild, moderate and severe Hallux valgus deformity was inquired. 427 foot and ankle surgeons answered the questionnaire. 388 participants were certified foot and ankle surgeons from one or both foot and ankle societies. Medical history (78%), preoperative radiographs (100%) and preoperative radiographic management (78%) are of high or very high importance for surgical decision pathway. Outcome scores are used by less than 20% regularly. Open surgery is still the gold standard, whereas minimally invasive surgery is performed by only 7%. Our survey showed that diagnostic standards are met regularly. There is a wide variation in the type of procedures used to treat Hallux valgus deformity. TMT I arthrodesis is preferred in severe Hallux valgus, but also used to treat moderate and mild deformities. Minimally invasive surgery is still used by a minority of surgeons. It remains to be seen, to what extent minimally invasive surgery will be performed in the future. Georg Thieme Verlag KG Stuttgart · New York.

  2. Diagnostic Performance and Confidence of Contrast-Enhanced Ultrasound in the Differential Diagnosis of Cystic and Cysticlike Liver Lesions.

    Science.gov (United States)

    Corvino, Antonio; Catalano, Orlando; Corvino, Fabio; Sandomenico, Fabio; Petrillo, Antonella

    2017-09-01

    The aims of this study were to assess the diagnostic performance of contrast-enhanced ultrasound (CEUS) in the characterization of atypical cystic and cysticlike focal liver lesions in comparison with conventional US and to determine whether the use of CEUS can reduce the need for further diagnostic workup. In a 3-year period 48 patients with 50 atypical cystic and cysticlike lesions found at conventional US underwent CEUS. Diagnostic confirmation was obtained in cytohistopathologic examinations, with other imaging modalities, and in follow-up. Overall, there were 24 cystic lesions and 26 cysticlike solid lesions, specifically 32 benign and 18 malignant lesions. The conventional US and CEUS images and cine loops were reviewed by two blinded readers independently. Sensitivity, specificity, area under the ROC curve (A z ), and interobserver agreement were calculated. Diagnostic performance improved after review of CEUS examinations by both readers (conventional US A z = 0.781 vs 0.972; CEUS A z = 0.734 vs 0.957). Interreader agreement increased, although slightly (conventional US weighted κ = 0.894; CEUS weighted κ = 0.953). In terms of differential diagnosis, the occurrence of correctly characterized lesions increased after CEUS for both readers (reader 1, 62% to 98%; reader 2, 56% to 96%). The development of low-acoustic-power CEUS has made it possible to identify several imaging features of cystic and cysticlike focal liver lesions that, in association with history and clinical findings, may help to correctly characterize them. Our data indicate the usefulness of CEUS in the evaluation of patients with these lesions.

  3. Performance and analysis of the TVTS diagnostic system on HT-7 tokamak

    International Nuclear Information System (INIS)

    Han Xiaofeng; Shao Chunqiang; Xi Xiaoqi; Zhao Junyu; Qing Zang; Yang Jianhua; Dai Xingxing

    2013-01-01

    A high spatial resolution imaging Thomson scattering diagnostic system was developed in ASIPP. After about one month trial running on the superconducting HT-7 tokamak, the system was proved to be capable of measuring plasma electron temperature. The system setup and data calibration are described in this paper and then the instrument function is studied in detail, as well as the measurement capability, an electron temperature of 50 eV to 2 keV and density beyond 1x10"1"9 m"-"3. Finally, the data processing method and experimental results are presented. (author)

  4. Evaluation of the use of on-board spacecraft energy storage for electric propulsion missions

    Science.gov (United States)

    Poeschel, R. L.; Palmer, F. M.

    1983-01-01

    On-board spacecraft energy storage represents an under utilized resource for some types of missions that also benefit from using relatively high specific impulse capability of electric propulsion. This resource can provide an appreciable fraction of the power required for operating the electric propulsion subsystem in some missions. The most probable mission requirement for utilization of this energy is that of geostationary satellites which have secondary batteries for operating at high power levels during eclipse. The study summarized in this report selected four examples of missions that could benefit from use of electric propulsion and on-board energy storage. Engineering analyses were performed to evaluate the mass saved and economic benefit expected when electric propulsion and on-board batteries perform some propulsion maneuvers that would conventionally be provided by chemical propulsion. For a given payload mass in geosynchronous orbit, use of electric propulsion in this manner typically provides a 10% reduction in spacecraft mass.

  5. Diagnostic Performance of CT Colonography for the Detection of Colorectal Polyps

    International Nuclear Information System (INIS)

    Yun, Ji Young; Ro, Hee Jeong; Choi, Jung Bin; Chung, Ji Eun; Kim, Yong Jin; Suh, Won Hyuck; Lee, Jong Kyun; Park, Jong Beom

    2007-01-01

    To investigate the diagnostic value of CT colonography for the detection of colorectal polyps. From December 2004 to December 2005, 399 patients underwent CT colonography and follow-up conventional colonoscopy. We excluded cases of advanced colorectal cancer. We retrospectively analyzed the CT colonography findings and follow-up conventional colonoscopy findings of 113 patients who had polyps more than 6 mm in diameter. Radiologists using 3D and 2D computer generated displays interpreted the CT colonography images. The colonoscopists were aware of the CT colonography findings before the procedure. CT colonography detected 132 polyps in 107 of the 113 patients and conventional colonoscopy detected 114 colorectal polyps more than 6 mm in diameter in 87 of the 113 patients. The sensitivity of CT colonography analyzed per polyp was 91% (41/45) for polyps more than 10 mm in diameter and 89% (101/114) for polyps more than 6 mm in diameter. Thirteen polyps were missed by CT colonography and were detected on follow-up conventional colonoscopy. CT colonography is a sensitive diagnostic tool for the detection of colorectal polyps and adequate bowel preparation, optimal bowel distention and clinical experience are needed to reduce the rate of missing appropriate lesions

  6. Diagnostic performance of 320-detector CT coronary angiography in patients with atrial fibrillation: preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Lei; Yang, Lin; Fan, Zhanming; Yu, Wei; Lv, Biao; Zhang, Zhaoqi [Capital Medical University, Department of Radiology, Beijing Anzhen Hospital, Beijing (China)

    2011-05-15

    To evaluate the feasibility, diagnostic accuracy, and radiation dose of CT coronary angiography (CTCA) in patients with atrial fibrillation (AF) using 320-detector CT. Thirty-seven patients with persistent AF and suspected coronary artery disease (CAD) were enrolled. All patients underwent both 320-detector CTCA and conventional coronary angiography (CCA). CT image quality and the presence of significant ({>=}50%) stenosis were evaluated by two radiologists blinded to the results of CCA. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated using CCA as the reference standard. Differences in detection of coronary artery stenosis between 320-detector CTCA and CCA were evaluated with McNemar's test. Patient radiation dose was calculated by multiplying dose length product by conversion coefficient of 0.017. In total 474 evaluated coronary segments, 459 (96.8%) segments were diagnostically evaluable. On per-segment analysis, sensitivity, specificity, PPV and NPV were 90.0% (18 of 20), 99.3% (436 of 439), 85.7% (18 of 21) and 99.5% (436 of 438). No significant difference was found between 320-detector CTCA and CCA on the detection of significant stenosis (P = 1.000). Effective doses of 320-detector CTCA was 13.0 {+-} 4.7 mSv. 320-detector CTCA is feasible and accurate in excluding CAD in patients with AF. (orig.)

  7. Myeloma-Derived Light Chain Paired with a Diagnostic Monoclonal Antibody Hinders Immunoassay Performance.

    Science.gov (United States)

    Tu, Bailin; Tieman, Bryan; Moore, Jeffrey; Pan, You; Muerhoff, A Scott

    2017-06-01

    Monoclonal antibodies are widely used as the capture and detection reagents in diagnostic immunoassays. In the past, myeloma fusion partners expressing endogenous heavy and/or light chains were often used to generate hybridoma cell lines. As a result, mixed populations of antibodies were produced that can cause inaccurate test results, poor antibody stability, and significant lot-to-lot variability. We describe one such scenario where the P3U1 (P3X63Ag8U.1) myeloma fusion partner was used in the generation of a hybridoma producing protein induced vitamin K absence/antagonist-II (PIVKA II) antibody. The hybridoma produces three subpopulations of immunoglobulin as determined by ion exchange (IEx) chromatography that exhibit varying degrees of immunoreactivity (0%, 50%, or 100%) to the target antigen as determined by Surface Plasmon Resonance. To produce an antibody with the highest possible sensitivity and specificity, the antigen-specific heavy and light chain variable domains (VH and VL) were cloned from the hybridoma and tethered to murine IgG1 and kappa scaffolds. The resulting recombinant antibody was expressed in Chinese hamster ovary cells and is compatible for use in a diagnostic immunoassay.

  8. Tomosynthesis for the early detection of pulmonary emphysema: diagnostic performance compared with chest radiography, using multidetector computed tomography as reference.

    Science.gov (United States)

    Yamada, Yoshitake; Jinzaki, Masahiro; Hashimoto, Masahiro; Shiomi, Eisuke; Abe, Takayuki; Kuribayashi, Sachio; Ogawa, Kenji

    2013-08-01

    To compare the diagnostic performance of tomosynthesis with that of chest radiography for the detection of pulmonary emphysema, using multidetector computed tomography (MDCT) as reference. Forty-eight patients with and 63 without pulmonary emphysema underwent chest MDCT, tomosynthesis and radiography on the same day. Two blinded radiologists independently evaluated the tomosynthesis images and radiographs for the presence of pulmonary emphysema. Axial and coronal MDCT images served as the reference standard and the percentage lung volume with attenuation values of -950 HU or lower (LAA-950) was evaluated to determine the extent of emphysema. Receiver-operating characteristic (ROC) analysis and generalised estimating equations model were used. ROC analysis revealed significantly better performance (P pulmonary emphysema. The average sensitivity, specificity, positive predictive value and negative predictive value of tomosynthesis were 0.875, 0.968, 0.955 and 0.910, respectively, whereas the values for radiography were 0.479, 0.913, 0.815 and 0.697, respectively. For both tomosynthesis and radiography, the sensitivity increased with increasing LAA-950. The diagnostic performance of tomosynthesis was significantly superior to that of radiography for the detection of pulmonary emphysema. In both tomosynthesis and radiography, the sensitivity was affected by the LAA-950. • Tomosynthesis showed significantly better diagnostic performance for pulmonary emphysema than radiography. • Interobserver agreement for tomosynthesis was significantly higher than that for radiography. • Sensitivity increased with increasing LAA -950 in both tomosynthesis and radiography. • Tomosynthesis imparts a similar radiation dose to two projection chest radiography. • Radiation dose and cost of tomosynthesis are lower than those of MDCT.

  9. Clinical and Demographic Stratification of Test Performance: A Pooled Analysis of Five Laboratory Diagnostic Methods for American Cutaneous Leishmaniasis

    Science.gov (United States)

    Boggild, Andrea K.; Ramos, Ana P.; Espinosa, Diego; Valencia, Braulio M.; Veland, Nicolas; Miranda-Verastegui, Cesar; Arevalo, Jorge; Low, Donald E.; Llanos-Cuentas, Alejandro

    2010-01-01

    We evaluated performance characteristics of five diagnostic methods for cutaneous leishmaniasis. Patients who came to the Leishmania Clinic of Hospital Nacional Cayetano Heredia in Lima, Peru, were enrolled in the study. Lesion smears, culture, microculture, polymerase chain reaction (PCR), and leishmanin skin test (LST) were performed. A total of 145 patients with 202 lesions were enrolled: 114 patients with 161 lesions fulfilled criteria for cutaneous leishmaniasis. Sensitivity and specificity were 57.8% (95% confidence interval [CI] = 50.2–65.4%) and 100.0% for culture, 78.3% (95% CI = 71.9–84.7%) and 100.0% for microculture, 71.4% (95% CI = 64.4–78.4%) and 100.0% for smears, 78.2% (95% CI = 70.6–85.8%) and 77.4% (95% CI = 62.7–92.1%) for LST, and 96.9% (95% CI = 94.2–99.6%) and 65.9% (95% CI = 51.4–80.4%) for PCR. PCR was more sensitive than the other assays (P < 0.001). Sensitivities of culture, smears, and LST varied by lesion duration and appearance. PCR offers performance advantages over other assays, irrespective of patient age, sex, lesion duration, or appearance. That clinical factors influence performance of non-molecular assays offers clinicians a patient-focused approach to diagnostic test selection. PMID:20682880

  10. The Clinical Utility and Diagnostic Performance of MRI for Identification of Early and Advanced Knee Osteoarthritis: A Systematic Review

    Science.gov (United States)

    Quatman, Carmen E.; Hettrich, Carolyn M.; Schmitt, Laura C.; Spindler, Kurt P.

    2013-01-01

    Background Current diagnostic strategies for detection of structural articular cartilage abnormalities, the earliest structural signs of osteoarthritis, often do not capture the condition until it is too far advanced for the most potential benefit of non-invasive interventions. Purpose Systematically review the literature relative to the following questions: (1) Is MRI a valid, sensitive, specific, accurate and reliable instrument to identify knee articular cartilage abnormalities compared to arthroscopy? (2) Is MRI a sensitive tool that can be utilized to identify early cartilage degeneration? Study Design Systematic Review Methods A systematic search was performed in November 2010 using PubMed MEDLINE (from 1966), CINAHL (from 1982), SPORTDiscus (from 1985), and SCOPUS (from 1996) databases. Results Fourteen level I and 13 level II studies were identified that met inclusion criteria and provided information related to diagnostic performance of MRI compared to arthroscopic evaluation. The diagnostic performance of MRI demonstrated a large range of sensitivities, specificities, and accuracies. The sensitivity for identifying articular cartilage abnormalities in the knee joint was reported between 26–96%. Specificity and accuracy was reported between 50–100% and 49–94%, respectively. The sensitivity, specificity, and accuracy for identifying early osteoarthritis were reported between 0–86%, 48–95%, and 5–94%, respectively. As a result of inconsistencies between imaging techniques and methodological shortcomings of many of the studies, a meta-analysis was not performed and it was difficult to fully synthesize the information to state firm conclusions about the diagnostic performance of MRI. Conclusions There is evidence in some MRI protocols that MRI is a relatively valid, sensitive, specific, accurate, and reliable clinical tool for identifying articular cartilage degeneration. Due to heterogeneity of MRI sequences it is not possible to make definitive

  11. Evaluation of the diagnostic performance and operational characteristics of four rapid immunochromatographic syphilis tests in Burkina Faso.

    Science.gov (United States)

    Bocoum, Fadima Yaya; Ouédraogo, Henri; Tarnagda, Grissoum; Kiba, Alice; Tiendrebeogo, Simon; Bationo, Fabrice; Liestman, Benjamin; Diagbouga, Serge; Zarowsky, Christina; Traoré, Ramata Ouédraogo; Kouanda, Séni

    2015-06-01

    Little information is available on the rapid diagnostic testing for syphilis in Burkina Faso. The objectives of the study were (i) to assess the sensitivity and specificity of four on site rapid tests in comparison with Treponema pallidum haemagglutination assay (TPHA) as a gold standard and (ii) to evaluate the operational characteristics of those tests among health workers in a maternity unit. Four rapid syphilis tests commercially available in Burkina Faso were evaluated using archived serum samples and Treponema pallidum hemagglutination assay (TPHA) as the gold standard. Blood samples were collected between November 2011 and June 2012 from blood donors at the Regional Blood Transfusion Center of Ouagadougou. The sensitivity and specificity of the tests were calculated. Evaluation of operational characteristics such as clarity of pamphlet, complexity of technique, duration, was conducted in a first-level healthcare center with health workers in maternity unit. Alere DetermineTM Syphilis was the most sensitive of the four rapid syphilis tests evaluated. It was followed by SD Bioline Syphilis 3.0, Cypress Diagnostics Syphilis Quick test and Accu-Tell ® Rapid Anti-TP, which was the least sensitive. The four tests demonstrated a good diagnostic specificity for syphilis (95-98%), and healthcare workers found them easy to use. The study allowed confirming the good performance of three of four rapid syphilis tests in Burkina Faso. More research will be conducted to assess the feasibility of introducing selected rapid tests for syphilis in antenatal care services.

  12. Diagnostic performance of a novel cadmium-zinc-telluride gamma camera system assessed using fractional flow reserve.

    Science.gov (United States)

    Tanaka, Hirokazu; Chikamori, Taishiro; Tanaka, Nobuhiro; Hida, Satoshi; Igarashi, Yuko; Yamashita, Jun; Ogawa, Masashi; Shiba, Chie; Usui, Yasuhiro; Yamashina, Akira

    2014-01-01

    Although the novel cadmium-zinc-telluride (CZT) camera system provides excellent image quality, its diagnostic value using thallium-201 as assessed on coronary angiography (CAG) and fractional flow reserve (FFR) has not been validated. METHODS AND RESULTS: To evaluate the diagnostic accuracy of the CZT ultrafast camera system (Discovery NM 530c), 95 patients underwent stress thallium-201 single-photon emission computed tomography (SPECT) and then CAG within 3 months. Image acquisition was performed in the supine and prone positions after stress for 5 and 3 min, respectively, and in the supine position at rest for 10 min. Significant stenosis was defined as ≥90% diameter narrowing on visual estimation, or a lesion with <90% and ≥50% stenosis and FFR ≤0.75. To detect individual coronary stenosis, the respective sensitivity, specificity, and accuracy were 90%, 64%, and 78% for left anterior descending coronary artery stenosis, 78%, 84%, and 81% for left circumflex stenosis, and 83%, 47%, and 60% for right coronary artery (RCA) stenosis. The combination of prone and supine imaging had a higher specificity for RCA disease than supine imaging alone (65% vs. 47%), with an improvement in accuracy from 60% to 72%. Using thallium-201 with short acquisition time, combined with prone imaging, CZT SPECT had a high diagnostic yield in detecting significant coronary stenosis as assessed using FFR.

  13. Method of optimization onboard communication network

    Science.gov (United States)

    Platoshin, G. A.; Selvesuk, N. I.; Semenov, M. E.; Novikov, V. M.

    2018-02-01

    In this article the optimization levels of onboard communication network (OCN) are proposed. We defined the basic parameters, which are necessary for the evaluation and comparison of modern OCN, we identified also a set of initial data for possible modeling of the OCN. We also proposed a mathematical technique for implementing the OCN optimization procedure. This technique is based on the principles and ideas of binary programming. It is shown that the binary programming technique allows to obtain an inherently optimal solution for the avionics tasks. An example of the proposed approach implementation to the problem of devices assignment in OCN is considered.

  14. On-board processing for telecommunications satellites

    Science.gov (United States)

    Nuspl, P. P.; Dong, G.

    1991-01-01

    In this decade, communications satellite systems will probably face dramatic challenges from alternative transmission means. To balance and overcome such competition, and to prepare for new requirements, INTELSAT has developed several on-board processing techniques, including Satellite-Switched TDMA (SS-TDMA), Satellite-Switched FDMA (SS-FDMA), several Modulators/Demodulators (Modem), a Multicarrier Multiplexer and Demodulator MCDD), an International Business Service (IBS)/Intermediate Data Rate (IDR) BaseBand Processor (BBP), etc. Some proof-of-concept hardware and software were developed, and tested recently in the INTELSAT Technical Laboratories. These techniques and some test results are discussed.

  15. Analytical and diagnostic performance of a qPCR assay for Ichthyophonus spp. compared to the tissue culture 'gold standard'.

    Science.gov (United States)

    Lowe, Vanessa C; Hershberger, Paul K; Friedman, Carolyn S

    2018-06-04

    Parasites of the genus Ichthyophonus infect many fish species and have a non-uniform distribution within host tissues. Due in part to this uneven distribution, the comparative sensitivity and accuracy of using molecular-based detection methods versus culture to estimate parasite prevalence is under debate. We evaluated the analytical and diagnostic performance of an existing qPCR assay in comparison to the 'gold standard' culture method using Pacific herring Clupea pallasii with known exposure history. We determined that the assay is suitable for use in this host, and diagnostic specificity was consistently high (>98%) in both heart and liver tissues. Diagnostic sensitivity could not be fully assessed due to low infection rates, but our results suggest that qPCR is not as sensitive as culture under all circumstances. Diagnostic sensitivity of qPCR relative to culture is likely affected by the amount of sample processed. The prevalence values estimated by the 2 methods were not significantly different when sample amounts were equal (heart tissue), but when the assayed sample amounts were unequal (liver tissue), the culture method detected a significantly higher prevalence of the parasite than qPCR. Further, culture of liver also detected significantly more Ichthyophonus infections than culture of heart, suggesting that the density and distribution of parasites in tissues also plays a role in assay sensitivity. This sensitivity issue would be most problematic for fish with light infections. Although qPCR does not detect the presence of a live organism, DNA-based pathogen detection methods provide the opportunity for alternate testing strategies when culture is not possible.

  16. Diagnostic Performance and Utility of Quantitative EEG Analyses in Delirium: Confirmatory Results From a Large Retrospective Case-Control Study.

    Science.gov (United States)

    Fleischmann, Robert; Tränkner, Steffi; Bathe-Peters, Rouven; Rönnefarth, Maria; Schmidt, Sein; Schreiber, Stephan J; Brandt, Stephan A

    2018-03-01

    The lack of objective disease markers is a major cause of misdiagnosis and nonstandardized approaches in delirium. Recent studies conducted in well-selected patients and confined study environments suggest that quantitative electroencephalography (qEEG) can provide such markers. We hypothesize that qEEG helps remedy diagnostic uncertainty not only in well-defined study cohorts but also in a heterogeneous hospital population. In this retrospective case-control study, EEG power spectra of delirious patients and age-/gender-matched controls (n = 31 and n = 345, respectively) were fitted in a linear model to test their performance as binary classifiers. We subsequently evaluated the diagnostic performance of the best classifiers in control samples with normal EEGs (n = 534) and real-world samples including pathologic findings (n = 4294). Test reliability was estimated through split-half analyses. We found that the combination of spectral power at F3-P4 at 2 Hz (area under the curve [AUC] = .994) and C3-O1 at 19 Hz (AUC = .993) provided a sensitivity of 100% and a specificity of 99% to identify delirious patients among normal controls. These classifiers also yielded a false positive rate as low as 5% and increased the pretest probability of being delirious by 57% in an unselected real-world sample. Split-half reliabilities were .98 and .99, respectively. This retrospective study yielded preliminary evidence that qEEG provides excellent diagnostic performance to identify delirious patients even outside confined study environments. It furthermore revealed reduced beta power as a novel specific finding in delirium and that a normal EEG excludes delirium. Prospective studies including parameters of pretest probability and delirium severity are required to elaborate on these promising findings.

  17. Diagnostic performance of indirect MR arthrography for the diagnosis of rotator cuff tears at 3.0 T.

    Science.gov (United States)

    Lee, Ji Hyun; Yoon, Young Cheol; Jee, Sukkyung

    2015-06-01

    Indirect magnetic resonance (MR) arthrography is a non-invasive method for shoulder imaging. However, there are no studies that have examined the diagnostic performance of indirect MR arthrography for the diagnosis of rotator cuff tears in a large patient population. To assess the diagnostic performance of indirect fast spin-echo (FSE) MR arthrography for the diagnosis of rotator cuff tears at 3.0 T. A total of 149 patients who had undergone indirect shoulder MR arthrography followed by arthroscopic surgery were enrolled in this retrospective study. Two musculoskeletal radiologists evaluated images from each patient for the presence of supraspinatus-infraspinatus (SSP-ISP) or subscapularis (SSC) tendon tears. Using the arthroscopic findings as the reference standard, the overall diagnostic performance and detection rates for SSP-ISP and SSC tendon tears were calculated. The sensitivity, specificity, and accuracy of readers I and II for the diagnosis of SSP-ISP tendon tears were 94% and 95%, 89% and 85%, and 93% and 93%, respectively. The sensitivity of imaging for detection of SSP-ISP tendon tears by readers I and II were 100% and 100% for full-thickness tears and 84% and 86% for partial-thickness tears, respectively. The sensitivity, specificity, and accuracy of readers I and II for the diagnosis of SSC tendon tears were 80% and 76%, 89% and 93%, and 85% and 85%, respectively. Indirect MR arthrography is useful for the detection of SSP-ISP and SSC tendon tears. © The Foundation Acta Radiologica 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  18. Diagnostic performance of calcification-suppressed coronary CT angiography using rapid kilovolt-switching dual-energy CT.

    Science.gov (United States)

    Yunaga, Hiroto; Ohta, Yasutoshi; Kaetsu, Yasuhiro; Kitao, Shinichiro; Watanabe, Tomomi; Furuse, Yoshiyuki; Yamamoto, Kazuhiro; Ogawa, Toshihide

    2017-07-01

    Multi-detector-row computed tomography angiography (MDCTA) plays an important role in the assessment of patients with suspected coronary artery disease. However, MDCTA tends to overestimate stenosis in calcified coronary artery lesions. The aim of our study was to evaluate the diagnostic performance of calcification-suppressed material density (MD) images produced by using a single-detector single-source dual-energy computed tomography (ssDECT). We enrolled 67 patients with suspected or known coronary artery disease who underwent ssDECT with rapid kilovolt-switching (80 and 140 kVp). Coronary artery stenosis was evaluated on the basis of MD images and virtual monochromatic (VM) images. The diagnostic performance of the two methods for detecting coronary artery disease was compared with that of invasive coronary angiography as a reference standard. We evaluated 239 calcified segments. In all the segments, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy for detecting significant stenosis were respectively 88%, 88%, 75%, 95% and 88% for the MD images, 91%, 71%, 56%, 95% and 77% for the VM images. PPV was significantly higher on the MD images than on the VM images (P < 0.0001). Calcification-suppressed MD images improved PPV and diagnostic performance for calcified coronary artery lesions. • Computed tomography angiography tends to overestimate stenosis in calcified coronary artery. • Dual-energy CT enables us to suppress calcification of coronary artery lesions. • Calcification-suppressed material density imaging reduces false-positive diagnosis of calcified lesion.

  19. Diagnostic performance of qualitative shear-wave elastography according to different color map opacities for breast masses

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hana; Youk, Ji Hyun, E-mail: jhyouk@yuhs.ac; Gweon, Hye Mi; Kim, Jeong-Ah; Son, Eun Ju

    2013-08-15

    Purpose: To compare the diagnostic performance of qualitative shear-wave elastography (SWE) according to three different color map opacities for breast masses Materials and methods: 101 patients aged 21–77 years with 113 breast masses underwent B-mode US and SWE under three different color map opacities (50%, 19% and 100%) before biopsy or surgery. Following SWE features were reviewed: visual pattern classification (pattern 1–4), color homogeneity (E{sub homo}) and six-point color score of maximum elasticity (E{sub col}). Combined with B-mode US and SWE, the likelihood of malignancy (LOM) was also scored. The area under the curve (AUC) was obtained by ROC curve analysis to assess the diagnostic performance under each color opacity. Results: A visual color pattern, E{sub homo}, E{sub col} and LOM scoring were significantly different between benign and malignant lesions under all color opacities (P < 0.001). For 50% opacity, AUCs of visual color pattern, E{sub col}, E{sub homo} and LOM scoring were 0.902, 0.951, 0.835 and 0.975. But, for each SWE feature, there was no significant difference in the AUC among three different color opacities. For all color opacities, visual color pattern and E{sub col} showed significantly higher AUC than E{sub homo}. In addition, a combined set of B-mode US and SWE showed significantly higher AUC than SWE alone for color patterns, E{sub homo}, but no significant difference was found in E{sub col}. Conclusion: Qualitative SWE was useful to differentiate benign from malignant breast lesion under all color opacities. The difference in color map opacity did not significantly influence diagnostic performance of SWE.

  20. Diagnostic performance of qualitative shear-wave elastography according to different color map opacities for breast masses

    International Nuclear Information System (INIS)

    Kim, Hana; Youk, Ji Hyun; Gweon, Hye Mi; Kim, Jeong-Ah; Son, Eun Ju

    2013-01-01

    Purpose: To compare the diagnostic performance of qualitative shear-wave elastography (SWE) according to three different color map opacities for breast masses Materials and methods: 101 patients aged 21–77 years with 113 breast masses underwent B-mode US and SWE under three different color map opacities (50%, 19% and 100%) before biopsy or surgery. Following SWE features were reviewed: visual pattern classification (pattern 1–4), color homogeneity (E homo ) and six-point color score of maximum elasticity (E col ). Combined with B-mode US and SWE, the likelihood of malignancy (LOM) was also scored. The area under the curve (AUC) was obtained by ROC curve analysis to assess the diagnostic performance under each color opacity. Results: A visual color pattern, E homo , E col and LOM scoring were significantly different between benign and malignant lesions under all color opacities (P < 0.001). For 50% opacity, AUCs of visual color pattern, E col , E homo and LOM scoring were 0.902, 0.951, 0.835 and 0.975. But, for each SWE feature, there was no significant difference in the AUC among three different color opacities. For all color opacities, visual color pattern and E col showed significantly higher AUC than E homo . In addition, a combined set of B-mode US and SWE showed significantly higher AUC than SWE alone for color patterns, E homo , but no significant difference was found in E col . Conclusion: Qualitative SWE was useful to differentiate benign from malignant breast lesion under all color opacities. The difference in color map opacity did not significantly influence diagnostic performance of SWE

  1. Tomosynthesis for the early detection of pulmonary emphysema: diagnostic performance compared with chest radiography, using multidetector computed tomography as reference

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Yoshitake [Keio University School of Medicine, Department of Diagnostic Radiology, Tokyo (Japan); Nippon Koukan Hospital, Department of Radiology, Kawasaki-shi, Kanagawa (Japan); Jinzaki, Masahiro; Hashimoto, Masahiro; Shiomi, Eisuke; Kuribayashi, Sachio [Keio University School of Medicine, Department of Diagnostic Radiology, Tokyo (Japan); Abe, Takayuki [Keio University School of Medicine, Center for Clinical Research, Tokyo (Japan); Ogawa, Kenji [Nippon Koukan Hospital, Department of Radiology, Kawasaki-shi, Kanagawa (Japan)

    2013-08-15

    To compare the diagnostic performance of tomosynthesis with that of chest radiography for the detection of pulmonary emphysema, using multidetector computed tomography (MDCT) as reference. Forty-eight patients with and 63 without pulmonary emphysema underwent chest MDCT, tomosynthesis and radiography on the same day. Two blinded radiologists independently evaluated the tomosynthesis images and radiographs for the presence of pulmonary emphysema. Axial and coronal MDCT images served as the reference standard and the percentage lung volume with attenuation values of -950 HU or lower (LAA{sub -950}) was evaluated to determine the extent of emphysema. Receiver-operating characteristic (ROC) analysis and generalised estimating equations model were used. ROC analysis revealed significantly better performance (P < 0.0001) of tomosynthesis than radiography for the detection of pulmonary emphysema. The average sensitivity, specificity, positive predictive value and negative predictive value of tomosynthesis were 0.875, 0.968, 0.955 and 0.910, respectively, whereas the values for radiography were 0.479, 0.913, 0.815 and 0.697, respectively. For both tomosynthesis and radiography, the sensitivity increased with increasing LAA{sub -950}. The diagnostic performance of tomosynthesis was significantly superior to that of radiography for the detection of pulmonary emphysema. In both tomosynthesis and radiography, the sensitivity was affected by the LAA{sub -950}. (orig.)

  2. C-arm flat-panel CT arthrography of the shoulder: Radiation dose considerations and preliminary data on diagnostic performance

    Energy Technology Data Exchange (ETDEWEB)

    Guggenberger, Roman; Ulbrich, Erika J.; Kaelin, Pascal; Pfammatter, Thomas; Alkadhi, Hatem; Andreisek, Gustav [University Hospital Zurich, Institute of Diagnostic and Interventional Radiology, Zuerich (Switzerland); Dietrich, Tobias J. [Balgrist University Hospital, Department of Radiology, Zurich (Switzerland); Scholz, Rosemarie; Koehler, Christoph; Elsaesser, Thilo [Siemens Healthcare GmbH, Business Area Advanced Therapies, Forchheim (Germany); Le Corroller, Thomas [Aix-Marseille Universite, CNRS, ISM UMR 7287, Marseille (France); Radiology Department, APHM, Marseille (France)

    2017-02-15

    To investigate radiation dose and diagnostic performance of C-arm flat-panel CT (FPCT) versus standard multi-detector CT (MDCT) shoulder arthrography using MRI-arthrography as reference standard. Radiation dose of two different FPCT acquisitions (5 and 20 s) and standard MDCT of the shoulder were assessed using phantoms and thermoluminescence dosimetry. FPCT arthrographies were performed in 34 patients (mean age 44 ± 15 years). Different joint structures were quantitatively and qualitatively assessed by two independent radiologists. Inter-reader agreement and diagnostic performance were calculated. Effective radiation dose was markedly lower in FPCT 5 s (0.6 mSv) compared to MDCT (1.7 mSv) and FPCT 20 s (3.4 mSv). Contrast-to-noise ratios (CNRs) were significantly (p < 0.05) higher in FPCT 20-s versus 5-s protocols. Inter-reader agreements of qualitative ratings ranged between κ = 0.47-1.0. Sensitivities for cartilage and rotator cuff pathologies were low for FPCT 5-s (40 % and 20 %) and moderate for FPCT 20-s protocols (75 % and 73 %). FPCT showed high sensitivity (81-86 % and 89-99 %) for bone and acromioclavicular-joint pathologies. Using a 5-s protocol FPCT shoulder arthrography provides lower radiation dose compared to MDCT but poor sensitivity for cartilage and rotator cuff pathologies. FPCT 20-s protocol is moderately sensitive for cartilage and rotator cuff tendon pathology with markedly higher radiation dose compared to MDCT. (orig.)

  3. Diagnostic Performance of Computed Tomography Colonography and Colonoscopy: A Prospective and Validated Analysis of 231 Paired Examinations

    International Nuclear Information System (INIS)

    Arnesen, R.B.; Benzon, E. von; Adamsen, S.; Svendsen, L.B.; Raaschou, H.O.; Hart Hansen, O.

    2007-01-01

    Background: Detection of colorectal tumors with computed tomography colonography (CTC) is an alternative to conventional colonoscopy (CC), and clarification of the diagnostic performance is essential for cost-effective use of both technologies. Purpose: To evaluate the diagnostic performance of CTC compared with CC. Material and Methods: 231 consecutive CTCs were performed prior to same-day scheduled CC. The radiologist and endoscopists were blinded to each other's findings. Patients underwent a polyethylene glycol bowel preparation, and were scanned in prone and supine positions using a single-detector helical CT scanner and commercially available software for image analysis. Findings were validated (matched) in an unblinded comparison with video-recordings of the CCs and re-CCs in cases of doubt. Results: For patients with polyps 5 mm and 10 mm, the sensitivity was 69% (95% CI 58-80%) and 81% (68-94%), and the specificity was 91% (84-98%) and 98% (93-100%), respectively. For detection of polyps 5 mm and 10 mm, the sensitivity was 66% (57-75%) and 77% (65-89%). A flat, elevated low-grade carcinoma was missed by CTC. One cancer relapse was missed by CC, and a cecal cancer was missed by an incomplete CC and follow-up double-contrast barium enema. Conclusion: CC was superior to CTC and should remain first choice for the diagnosis of colorectal polyps. However, for diagnosis of lesions 10 mm, CTC and CC should be considered as complementary methods

  4. C-arm flat-panel CT arthrography of the shoulder: Radiation dose considerations and preliminary data on diagnostic performance

    International Nuclear Information System (INIS)

    Guggenberger, Roman; Ulbrich, Erika J.; Kaelin, Pascal; Pfammatter, Thomas; Alkadhi, Hatem; Andreisek, Gustav; Dietrich, Tobias J.; Scholz, Rosemarie; Koehler, Christoph; Elsaesser, Thilo; Le Corroller, Thomas

    2017-01-01

    To investigate radiation dose and diagnostic performance of C-arm flat-panel CT (FPCT) versus standard multi-detector CT (MDCT) shoulder arthrography using MRI-arthrography as reference standard. Radiation dose of two different FPCT acquisitions (5 and 20 s) and standard MDCT of the shoulder were assessed using phantoms and thermoluminescence dosimetry. FPCT arthrographies were performed in 34 patients (mean age 44 ± 15 years). Different joint structures were quantitatively and qualitatively assessed by two independent radiologists. Inter-reader agreement and diagnostic performance were calculated. Effective radiation dose was markedly lower in FPCT 5 s (0.6 mSv) compared to MDCT (1.7 mSv) and FPCT 20 s (3.4 mSv). Contrast-to-noise ratios (CNRs) were significantly (p < 0.05) higher in FPCT 20-s versus 5-s protocols. Inter-reader agreements of qualitative ratings ranged between κ = 0.47-1.0. Sensitivities for cartilage and rotator cuff pathologies were low for FPCT 5-s (40 % and 20 %) and moderate for FPCT 20-s protocols (75 % and 73 %). FPCT showed high sensitivity (81-86 % and 89-99 %) for bone and acromioclavicular-joint pathologies. Using a 5-s protocol FPCT shoulder arthrography provides lower radiation dose compared to MDCT but poor sensitivity for cartilage and rotator cuff pathologies. FPCT 20-s protocol is moderately sensitive for cartilage and rotator cuff tendon pathology with markedly higher radiation dose compared to MDCT. (orig.)

  5. T1 mapping cardiovascular magnetic resonance imaging to detect myocarditis—Impact of slice orientation on the diagnostic performance

    Energy Technology Data Exchange (ETDEWEB)

    Bohnen, Sebastian, E-mail: s.bohnen@uke.de [University Medical Center Hamburg-Eppendorf, University Heart Center, General and Interventional Cardiology, Hamburg (Germany); Radunski, Ulf K., E-mail: u.radunski@uke.de [University Medical Center Hamburg-Eppendorf, University Heart Center, General and Interventional Cardiology, Hamburg (Germany); Lund, Gunnar K., E-mail: glund@uke.de [University Medical Center Hamburg-Eppendorf, Department of Diagnostic and Interventional Radiology, Hamburg (Germany); Tahir, Enver, E-mail: e.tahir@uke.de [University Medical Center Hamburg-Eppendorf, Department of Diagnostic and Interventional Radiology, Hamburg (Germany); Avanesov, Maxim, E-mail: m.avanesov@uke.de [University Medical Center Hamburg-Eppendorf, Department of Diagnostic and Interventional Radiology, Hamburg (Germany); Stehning, Christian, E-mail: christian.stehning@philips.com [Philips Research, Hamburg (Germany); Schnackenburg, Bernhard, E-mail: bernhard.schnackenburg@philips.com [Philips Healthcare Germany, Hamburg (Germany); Adam, Gerhard, E-mail: g.adam@uke.de [University Medical Center Hamburg-Eppendorf, Department of Diagnostic and Interventional Radiology, Hamburg (Germany); Blankenberg, Stefan, E-mail: s.blankenberg@uke.de [University Medical Center Hamburg-Eppendorf, University Heart Center, General and Interventional Cardiology, Hamburg (Germany); Muellerleile, Kai, E-mail: kamuellerleile@uke.de [University Medical Center Hamburg-Eppendorf, University Heart Center, General and Interventional Cardiology, Hamburg (Germany)

    2017-01-15

    Background: T1 mapping is a promising diagnostic tool to improve the diagnostic accuracy of cardiovascular magnetic resonance (CMR) in patients with suspected myocarditis. However, there are currently no data on the potential influence of slice orientation on the diagnostic performance of CMR. Thus, we compared the diagnostic performance of global myocardial T1 and extracellular volume (ECV) values to differentiate patients with myocarditis from healthy individuals between different slice orientations. Methods: This study included 48 patients with clinically defined myocarditis and 13 healthy controls who underwent CMR at 1.5 T. A modified Look-Locker inversion-recovery (MOLLI) sequence was used for T1 mapping before and 15 min after administration of 0.075 mmol/kg Gadolinium-BOPTA. T1 mapping was performed on three short and on three long axes slices, respectively. Native T1, post-contrast T1 and extracellular volume (ECV) −BOPTA maps were calculated using a dedicated plug-in written for the OsiriX software and compared between the mean value of three short-axes slices (3SAX), the central short-axis (1SAX), the mean value of three long-axes slices (3LAX), the four-chamber view (4CH), the three-chamber view (3CH) and the two-chamber view (2CH). Results: There were significantly lower native T1 values on 3LAX (1081 ms (1037–1131 ms)) compared to 3SAX (1107 ms (1069–1143 ms), p = 0.0022) in patients with myocarditis, but not in controls (1026 ms (1009–1059 ms) vs. 1039 ms (1023–1055 ms), p = 0.2719). The areas under the curve (AUC) to discriminate between myocarditis and healthy controls by native myocardial T1 were 0.85 (p < 0.0001) on 3SAX, 0.85 (p < 0.0001) on 1SAX, 0.76 (p = 0.0002) on 3LAX, 0.70 (p = 0.0075) on 4CH, 0.72 (p = 0.0020) on 3CH and 0.75 (p = 0.0003) on 2CH. The AUCs for ECV-BOPTA were 0.83 (p < 0.0001) on 3 SAX, 0.82 (p < 0.0001) on 1SAX, 0.77 (p = 0.0005) on 3LAX, 0.71 (p = 0.0079) on 4CH, 0.69 (p = 0.0371) on 3CH and 0.75 (p = 0.0006) on

  6. T1 mapping cardiovascular magnetic resonance imaging to detect myocarditis—Impact of slice orientation on the diagnostic performance

    International Nuclear Information System (INIS)

    Bohnen, Sebastian; Radunski, Ulf K.; Lund, Gunnar K.; Tahir, Enver; Avanesov, Maxim; Stehning, Christian; Schnackenburg, Bernhard; Adam, Gerhard; Blankenberg, Stefan; Muellerleile, Kai

    2017-01-01

    Background: T1 mapping is a promising diagnostic tool to improve the diagnostic accuracy of cardiovascular magnetic resonance (CMR) in patients with suspected myocarditis. However, there are currently no data on the potential influence of slice orientation on the diagnostic performance of CMR. Thus, we compared the diagnostic performance of global myocardial T1 and extracellular volume (ECV) values to differentiate patients with myocarditis from healthy individuals between different slice orientations. Methods: This study included 48 patients with clinically defined myocarditis and 13 healthy controls who underwent CMR at 1.5 T. A modified Look-Locker inversion-recovery (MOLLI) sequence was used for T1 mapping before and 15 min after administration of 0.075 mmol/kg Gadolinium-BOPTA. T1 mapping was performed on three short and on three long axes slices, respectively. Native T1, post-contrast T1 and extracellular volume (ECV) −BOPTA maps were calculated using a dedicated plug-in written for the OsiriX software and compared between the mean value of three short-axes slices (3SAX), the central short-axis (1SAX), the mean value of three long-axes slices (3LAX), the four-chamber view (4CH), the three-chamber view (3CH) and the two-chamber view (2CH). Results: There were significantly lower native T1 values on 3LAX (1081 ms (1037–1131 ms)) compared to 3SAX (1107 ms (1069–1143 ms), p = 0.0022) in patients with myocarditis, but not in controls (1026 ms (1009–1059 ms) vs. 1039 ms (1023–1055 ms), p = 0.2719). The areas under the curve (AUC) to discriminate between myocarditis and healthy controls by native myocardial T1 were 0.85 (p < 0.0001) on 3SAX, 0.85 (p < 0.0001) on 1SAX, 0.76 (p = 0.0002) on 3LAX, 0.70 (p = 0.0075) on 4CH, 0.72 (p = 0.0020) on 3CH and 0.75 (p = 0.0003) on 2CH. The AUCs for ECV-BOPTA were 0.83 (p < 0.0001) on 3 SAX, 0.82 (p < 0.0001) on 1SAX, 0.77 (p = 0.0005) on 3LAX, 0.71 (p = 0.0079) on 4CH, 0.69 (p = 0.0371) on 3CH and 0.75 (p = 0.0006) on

  7. Onboard monitoring of fatigue damage rates in the hull girder

    DEFF Research Database (Denmark)

    Nielsen, Ulrik Dam; Jensen, Jørgen Juncher; Pedersen, Preben Terndrup

    2011-01-01

    Most new advanced ships have extensive data collection systems to be used for continuous monitoring of engine and hull performance, for voyage performance evaluation etc. Such systems could be expanded to include also procedures for stress monitoring and for decision support, where the most...... critical wave-induced ship extreme responses and fatigue damage accumulation can be estimated for hypothetical changes in ship course and speed in the automatically estimated wave environment.The aim of this paper is to outline a calculation procedure for fatigue damage rate prediction in hull girders...... taking into account whipping stresses. It is conceptually shown how such a method, which integrates onboard estimation of sea states, can be used to deduce decision support with respect to the accumulated fatigue damage in the hull girder.The paper firstly presents a set of measured full-scale wave...

  8. A new on-board imaging treatment technique for palliative and emergency treatments in radiation oncology

    International Nuclear Information System (INIS)

    Held, Mareike

    2016-01-01

    This dissertation focuses on the use of on-board imaging systems as the basis for treatment planning, presenting an additional application for on-board images. A clinical workflow is developed to simulate, plan, and deliver a simple radiation oncology treatment rapidly, using 3D patient scans. The work focuses on an on-line dose planning and delivery process based on on-board images entirely performed with the patient set up on the treatment couch of the linear accelerator. This potentially reduces the time between patient simulation and treatment to about 30 minutes. The basis for correct dose calculation is the accurate image gray scale to tissue density calibration. The gray scale, which is defined in CT Numbers, is dependent on the energy spectrum of the beam. Therefore, an understanding of the physics characteristics of each on-board system is required to evaluate the impact on image quality, especially regarding the underlying cause of image noise, contrast, and non-uniformity. Modern on-board imaging systems, including kV and megavoltage (MV) cone beam (CB) CT as well as MV CT, are characterized in terms of image quality and stability. A library of phantom and patient CT images is used to evaluate the dose calculation accuracy for the on-board images. The dose calculation objective is to stay within 5% local dose differences compared to standard kV CT dose planning. The objective is met in many treatment cases. However, dose calculation accuracy depends on the anatomical treatment site. While on-board CT-based treatments of the head and extremities are predictable within 5% on all systems, lung tissue and air cavities may create local dose discrepancies of more than 5%. The image quality varies between the tested units. Consequently, the CT number-to-density calibration is defined independently for each system. In case of some imaging systems, the CT numbers of the images are dependent on the protocol used for on-board imaging, which defines the imaging dose

  9. A new on-board imaging treatment technique for palliative and emergency treatments in radiation oncology

    Energy Technology Data Exchange (ETDEWEB)

    Held, Mareike

    2016-03-23

    This dissertation focuses on the use of on-board imaging systems as the basis for treatment planning, presenting an additional application for on-board images. A clinical workflow is developed to simulate, plan, and deliver a simple radiation oncology treatment rapidly, using 3D patient scans. The work focuses on an on-line dose planning and delivery process based on on-board images entirely performed with the patient set up on the treatment couch of the linear accelerator. This potentially reduces the time between patient simulation and treatment to about 30 minutes. The basis for correct dose calculation is the accurate image gray scale to tissue density calibration. The gray scale, which is defined in CT Numbers, is dependent on the energy spectrum of the beam. Therefore, an understanding of the physics characteristics of each on-board system is required to evaluate the impact on image quality, especially regarding the underlying cause of image noise, contrast, and non-uniformity. Modern on-board imaging systems, including kV and megavoltage (MV) cone beam (CB) CT as well as MV CT, are characterized in terms of image quality and stability. A library of phantom and patient CT images is used to evaluate the dose calculation accuracy for the on-board images. The dose calculation objective is to stay within 5% local dose differences compared to standard kV CT dose planning. The objective is met in many treatment cases. However, dose calculation accuracy depends on the anatomical treatment site. While on-board CT-based treatments of the head and extremities are predictable within 5% on all systems, lung tissue and air cavities may create local dose discrepancies of more than 5%. The image quality varies between the tested units. Consequently, the CT number-to-density calibration is defined independently for each system. In case of some imaging systems, the CT numbers of the images are dependent on the protocol used for on-board imaging, which defines the imaging dose

  10. Chang?E-5T Orbit Determination Using Onboard GPS Observations

    OpenAIRE

    Su, Xing; Geng, Tao; Li, Wenwen; Zhao, Qile; Xie, Xin

    2017-01-01

    In recent years, Global Navigation Satellite System (GNSS) has played an important role in Space Service Volume, the region enclosing the altitudes above 3000 km up to 36,000 km. As an in-flight test for the feasibility as well as for the performance of GNSS-based satellite orbit determination (OD), the Chinese experimental lunar mission Chang?E-5T had been equipped with an onboard high-sensitivity GNSS receiver with GPS and GLONASS tracking capability. In this contribution, the 2-h onboard G...

  11. Clinical Evaluation of Iliopsoas Strain with Findings from Diagnostic Musculoskeletal Ultrasound in Agility Performance Canines – 73 Cases

    Directory of Open Access Journals (Sweden)

    Robert Cullen

    2017-06-01

    Full Text Available Objective: Iliopsoas injury and strain is a commonly diagnosed disease process, especially amongst working and sporting canines. There has been very little published literature regarding iliopsoas injuries and there is no information regarding the ultrasound evaluation of abnormal iliopsoas muscles. This manuscript is intended to describe the ultrasound findings in 73 canine agility athletes who had physical examination findings consistent with iliopsoas discomfort. The population was chosen given the high incidence of these animals for the development of iliopsoas injury; likely due to repetitive stress.Methods: Medical records of 73 agility performance canines that underwent musculoskeletal ultrasound evaluation of bilateral iliopsoas muscle groups were retrospectively reviewed. Data included signalment, previous radiographic findings, and ultrasound findings. A 3-tier grading scheme for acute strains was used while the practitioner also evaluated for evidence of chronic injury and bursitis.Results: The majority of pathologies were localised to the tendon of insertion, with the majority being low grade I-II strains (80.8%. Tendon fibre disruption (71.2% and indistinct hypoechoic lesions (91.8% were the most common of acute changes noted. Hyperechoic chronic changes were noted in 84.9 percent of cases. Acute and chronic changes were commonly seen together (62.8%.Conclusion: Diagnostic musculoskeletal ultrasound was used to identify lesions of the iliopsoas tendon consistent with acute and chronic injury, as well as identifying the region of pathology. The majority of agility performance dogs had low grade acute strains based on the tiered system, with mixed acute and chronic lesions being noted frequently.Application: Diagnostic musculoskeletal ultrasound provides a non-invasive diagnostic modality for patients suspected of having an iliopsoas strain.

  12. Orienting and Onboarding Clinical Nurse Specialists: A Process Improvement Project.

    Science.gov (United States)

    Garcia, Mayra G; Watt, Jennifer L; Falder-Saeed, Karie; Lewis, Brennan; Patton, Lindsey

    Clinical nurse specialists (CNSs) have a unique advanced practice role. This article describes a process useful in establishing a comprehensive orientation and onboarding program for a newly hired CNS. The project team used the National Association of Clinical Nurse Specialists core competencies as a guide to construct a process for effectively onboarding and orienting newly hired CNSs. Standardized documents were created for the orientation process including a competency checklist, needs assessment template, and professional evaluation goals. In addition, other documents were revised to streamline the orientation process. Standardizing the onboarding and orientation process has demonstrated favorable results. As of 2016, 3 CNSs have successfully been oriented and onboarded using the new process. Unique healthcare roles require special focus when onboarding and orienting into a healthcare system. The use of the National Association of Clinical Nurse Specialists core competencies guided the project in establishing a successful orientation and onboarding process for newly hired CNSs.

  13. The Green Propellant Infusion Mission Thruster Performance Testing for Plume Diagnostics

    Science.gov (United States)

    Deans, Matthew C.; Reed, Brian D.; Arrington, Lynn A.; Williams, George J.; Kojima, Jun J.; Kinzbach, McKenzie I.; McLean, Christopher H.

    2014-01-01

    The Green Propellant Infusion Mission (GPIM) is sponsored by NASA's Space Technology Mission Directorate (STMD) Technology Demonstration Mission (TDM) office. The goal of GPIM is to advance the technology readiness level of a green propulsion system, specifically, one using the monopropellant, AF-M315E, by demonstrating ground handling, spacecraft processing, and on-orbit operations. One of the risks identified for GPIM is potential contamination of sensitive spacecraft surfaces from the effluents in the plumes of AF-M315E thrusters. NASA Glenn Research Center (GRC) is conducting activities to characterize the effects of AF-M315E plume impingement and deposition. GRC has established individual plume models of the 22-N and 1-N thrusters that will be used on the GPIM spacecraft. The model simulations will be correlated with plume measurement data from Laboratory and Engineering Model 22-N, AF-M315E thrusters. The thrusters are currently being tested in a small rocket, altitude facility at NASA GRC. A suite of diagnostics, including Raman spectroscopy, Rayleigh spectroscopy, and Schlieren imaging are being used to acquire plume measurements of AF-M315E thrusters. Plume data will include temperature, velocity, relative density, and species concentration. The plume measurement data will be compared to the corresponding simulations of the plume model. The GRC effort will establish a data set of AF-M315E plume measurements and a plume model that can be used for future AF-M315E applications.

  14. Analysis of mental disorders in tinnitus patients performed with Composite International Diagnostic Interview.

    Science.gov (United States)

    Zirke, N; Seydel, C; Arsoy, D; Klapp, B F; Haupt, H; Szczepek, A J; Olze, H; Goebel, G; Mazurek, B

    2013-10-01

    Known association between tinnitus and psychological distress prompted us to examine patients with chronic tinnitus by using the Composite International Diagnostic Interview (CIDI), which is a standardized and reliable method used for the diagnosis of mental disorders. One hundred patients with chronic tinnitus admitted to the Tinnitus Center, Charité-Universitätsmedizin Berlin, were included in this study. Data were collected between February 2008 and February 2009. Besides CIDI, the Tinnitus Questionnaire according to Goebel and Hiller, the Hospital Anxiety Depression Scale, and the General Anxiety Disorder-7 were used. Using CIDI, we have identified one or more mental disorders in 46 tinnitus patients. In that group, we found persistent affective disorders (37 %), anxiety disorders (32 %), and somatoform disorders (27 %). Those patients who had affective or anxiety disorders were more distressed by tinnitus and were more anxious and more depressed than tinnitus patients without mental disorders. Psychological impairment positively correlated with tinnitus distress: Patients with decompensated tinnitus had significantly more affective and anxiety disorders than patients with compensated tinnitus. In the present study, we have detected a high rate (almost half of the cases) of psychological disorders occurring in patients with chronic tinnitus. The patients diagnosed with psychological disorders were predominantly affected by affective and anxiety disorders. Psychological disorders were associated with severity of tinnitus distress. Our findings imply a need for routine comprehensive screening of mental disorders in patients with chronic tinnitus.

  15. Success, Failure and Emotions: Examining the Relationship between Performance Feedback and Emotions in Diagnostic Reasoning

    Science.gov (United States)

    Jarrell, Amanda; Harley, Jason M.; Lajoie, Susanne; Naismith, Laura

    2017-01-01

    Students experience a variety of emotions following achievement outcomes which stand to influence how they learn and perform in academic settings. However, little is known about the link between student outcome emotions and dimensions of performance feedback in computer-based learning environments (CBLEs). Understanding the dynamics of this…

  16. Performance of thyroid scintigraphy in the thyrotoxicosis etiological diagnosis: about 210 cases; Performance de la scintigraphie thyroidienne dans le diagnostic etiologique des thyrotoxicoses: a propos de 210 cas

    Energy Technology Data Exchange (ETDEWEB)

    Chatti, K.; Nouira, M.; Guezguez, M.; Sfar, R.; Essabbah, H. [CHU Sahloul, Service de medecine nucleaire, Sousse (Tunisia); Zantour, B. [CHU Mahdia, service d' endocrinologie (Tunisia)

    2010-07-01

    Purpose: The thyrotoxicosis is a syndrome linked to thyroid hormones excess grouping any causes leading to a overload in circulating hormones, including these ones linked to an inflammatory process (thyroiditis) or an exogenous contribution. The etiologic diagnosis is based on complementary examinations. The objective of our work is to elucidate the performance of scintigraphy in the etiologic diagnosis and the therapy approach of thyrotoxicosis through the experience of our service. Conclusions: Scintigraphy has a place in the etiologic diagnosis of thyrotoxicosis. it brings functional and morphological information and allows to guide the diagnostic and therapeutic approach. (N.C.)

  17. Identifying Onboarding Heuristics for Free-to-Play Mobile Games

    DEFF Research Database (Denmark)

    Thomsen, Line Ebdrup; Weigert Petersen, Falko; Drachen, Anders

    2016-01-01

    a set of heuristics for the design of onboarding phases in mobile games is presented. The heuristics are identified by a lab-based mixed-methods experiment, utilizing lightweight psycho-physiological measures together with self-reported player responses, across three titles that cross the genres...... of puzzle games, base builders and arcade games, and utilize different onboarding phase design approaches. Results showcase how heuristics can be used to design engaging onboarding phases in mobile games....

  18. Performance of Physical Examination Skills in Medical Students during Diagnostic Medicine Course in a University Hospital of Northwest China

    Science.gov (United States)

    Li, Yan; Li, Na; Han, Qunying; He, Shuixiang; Bae, Ricard S.; Liu, Zhengwen; Lv, Yi; Shi, Bingyin

    2014-01-01

    This study was conducted to evaluate the performance of physical examination (PE) skills during our diagnostic medicine course and analyze the characteristics of the data collected to provide information for practical guidance to improve the quality of teaching. Seventy-two fourth-year medical students were enrolled in the study. All received an assessment of PE skills after receiving a 17-week formal training course and systematic teaching. Their performance was evaluated and recorded in detail using a checklist, which included 5 aspects of PE skills: examination techniques, communication and care skills, content items, appropriateness of examination sequence, and time taken. Error frequency and type were designated as the assessment parameters in the survey. The results showed that the distribution and the percentage in examination errors between male and female students and among the different body parts examined were significantly different (pexaminations was higher than in abdominal (0.867) and head, neck and nervous system examinations (0.917). Female students had a lower average error frequency than males in cardiac examinations (p = 0.041). Additionally, error in examination techniques was the highest type of error among the 5 aspects of PE skills irrespective of participant gender and assessment content (pexaminations and examination techniques may be included in the main focus of improving the teaching of diagnostics in these medical students. PMID:25329685

  19. Metal artifact suppression at the hip: diagnostic performance at 3.0 T versus 1.5 Tesla

    Energy Technology Data Exchange (ETDEWEB)

    Nardo, Lorenzo; Han, Misung; Kretschmar, Martin; Krug, Roland; Link, Thomas M. [University of California San Francisco, Musculoskeletal and Quantitative Imaging Research, Department of Radiology and Biomedical Imaging, San Francisco, CA (United States); Guindani, Michele [The University of Texas MD Anderson Cancer Center, Department of Biostatistics - Unit 1411, Houston, TX (United States); Koch, Kevin [Medical College of Wisconsin, Department of Biophysics, Milwaukee, WI (United States); Medical College of Wisconsin, Department of Radiology, Milwaukee, WI (United States); Vail, Thomas [University of California San Francisco, Department of Orthopedic Surgery, San Francisco, CA (United States)

    2015-11-15

    This work aimed to compare the diagnostic performance of a metal artifact suppression sequence (MAVRIC-SL) for imaging of hip arthroplasties (HA) at 1.5 and 3 Tesla (T) field strength. Eighteen patients (10 females; aged 27-74) with HA were examined at 3.0 and 1.5 T within 3 weeks. The sequence protocol included 3D-MAVRIC-SL PD (coronal), 3D-MAVRIC-SL STIR (axial), FSE T1, FSE PD and STIR sequences. Anatomical structures and pathological findings were assessed independently by two radiologists. Artifact extent and technical quality (image quality, fat saturation and geometric distortion) were also evaluated. Findings at 1.5 and 3.0 T were compared using a Wilcoxon signed rank test. While image quality was better at 1.5 T, visualization of anatomic structures and clinical abnormalities was not significantly different using the two field strengths (p > 0.05). Fat suppression and amount of artifacts were significantly better at 1.5 T (p < 0.01). Inter- and intra-reader agreement for different anatomic details, image quality and visualization of abnormalities ranged from k = 0.62 to k = 1.00. MAVRIC-SL at 1.5 T had a comparable diagnostic performance when compared MAVRIC-SL at 3.0 T; however, the higher field strength was associated with larger artifacts, limited image quality and worse fat saturation. (orig.)

  20. Metal artifact suppression at the hip: diagnostic performance at 3.0 T versus 1.5 Tesla

    International Nuclear Information System (INIS)

    Nardo, Lorenzo; Han, Misung; Kretschmar, Martin; Krug, Roland; Link, Thomas M.; Guindani, Michele; Koch, Kevin; Vail, Thomas

    2015-01-01

    This work aimed to compare the diagnostic performance of a metal artifact suppression sequence (MAVRIC-SL) for imaging of hip arthroplasties (HA) at 1.5 and 3 Tesla (T) field strength. Eighteen patients (10 females; aged 27-74) with HA were examined at 3.0 and 1.5 T within 3 weeks. The sequence protocol included 3D-MAVRIC-SL PD (coronal), 3D-MAVRIC-SL STIR (axial), FSE T1, FSE PD and STIR sequences. Anatomical structures and pathological findings were assessed independently by two radiologists. Artifact extent and technical quality (image quality, fat saturation and geometric distortion) were also evaluated. Findings at 1.5 and 3.0 T were compared using a Wilcoxon signed rank test. While image quality was better at 1.5 T, visualization of anatomic structures and clinical abnormalities was not significantly different using the two field strengths (p > 0.05). Fat suppression and amount of artifacts were significantly better at 1.5 T (p < 0.01). Inter- and intra-reader agreement for different anatomic details, image quality and visualization of abnormalities ranged from k = 0.62 to k = 1.00. MAVRIC-SL at 1.5 T had a comparable diagnostic performance when compared MAVRIC-SL at 3.0 T; however, the higher field strength was associated with larger artifacts, limited image quality and worse fat saturation. (orig.)

  1. Visually assessed colour overlay features in shear-wave elastography for breast masses: quantification and diagnostic performance.

    Science.gov (United States)

    Gweon, Hye Mi; Youk, Ji Hyun; Son, Eun Ju; Kim, Jeong-Ah

    2013-03-01

    To determine whether colour overlay features can be quantified by the standard deviation (SD) of the elasticity measured in shear-wave elastography (SWE) and to evaluate the diagnostic performance for breast masses. One hundred thirty-three breast lesions in 119 consecutive women who underwent SWE before US-guided core needle biopsy or surgical excision were analysed. SWE colour overlay features were assessed using two different colour overlay pattern classifications. Quantitative SD of the elasticity value was measured with the region of interest including the whole breast lesion. For the four-colour overlay pattern, the area under the ROC curve (Az) was 0.947; with a cutoff point between pattern 2 and 3, sensitivity and specificity were 94.4 % and 81.4 %. According to the homogeneity of the elasticity, the Az was 0.887; with a cutoff point between reasonably homogeneous and heterogeneous, sensitivity and specificity were 86.1 % and 82.5 %. For the SD of the elasticity, the Az was 0.944; with a cutoff point of 12.1, sensitivity and specificity were 88.9 % and 89.7 %. The colour overlay features showed significant correlations with the quantitative SD of the elasticity (P < 0.001). The colour overlay features and the SD of the elasticity in SWE showed excellent diagnostic performance and showed good correlations between them.

  2. The Use of the Performance Diagnostic Checklist-Human Services to Assess and Improve the Job Performance of Individuals with Intellectual Disabilities.

    Science.gov (United States)

    Smith, Madison; Wilder, David A

    2018-06-01

    The Performance Diagnostic Checklist-Human Services (PDC-HS) is an informant-based tool designed to identify the variables responsible for performance problems. To date, the PDC-HS has not been examined with individuals with intellectual disabilities. In the current study, two supervisors with intellectual disabilities completed the PDC-HS to assess the productivity of two supervisees with disabilities who performed a pricing task in a thrift store. The PDC-HS suggested that performance deficits were due to a lack of training; a PDC-HS-indicated intervention was effective to increase accurate pricing. • The PDC-HS is an informant-based tool designed to identify the variables responsible for employee performance problems in human service settings. • The PDC-HS can be completed by some individuals with intellectual disabilities in a supervisory position to identify the variables responsible for problematic job performance among their supervisees. • A PDC-HS indicated intervention was demonstrated to be effective to improve the job performance of individuals with disabilities. • The PDC-HS may be a useful tool to support performance improvement and job maintenance among individuals with intellectual disabilities.

  3. Crohn's Disease Evaluated with Magnetic Resonance Enteroclysis: Diagnostic Performance of Experienced and Inexperienced Readers before and after Training

    International Nuclear Information System (INIS)

    Negaard, A.; Mulahasanovic, A.; Reisaeter, L.A.; Aasekjaer, K.; Sandvik, L.; Klow, N.E.

    2008-01-01

    Background: Magnetic resonance enteroclysis (MRE) is suggested to become the preferred radiological method in small-bowel Crohn's disease (CD). However, the performance of inexperienced readers may influence the diagnostic value of the method and has not been previously investigated. Purpose: To compare readings of MRE in small-bowel CD performed by experienced and inexperienced readers before and after training.Material and Methods: One experienced radiologist (observer 1) and two trainees (observers 2 and 3) reviewed 60 MRE examinations. A second reading was performed after training. Bowel wall thickness (BWT), ulcers (BWU), stenosis (BWS), fistulas (FIS), and abscesses (ABS) were evaluated. A reference standard based on clinical records was established. Results: BWT in the terminal ileum was evaluated with high diagnostic performance (sensitivity: observer 1, 83%; observer 2, 72%; observer 3, 78%). Only BWU was diagnosed with a higher sensitivity by observer 1 (78% vs. 33% and 39%, respectively; P=0.02). False-positive findings for BWT in the jejunum (observer 2: 7; observer 3: 4) and fistulas and abscesses (observer 2: 11/5; observer 3: 5/4) were made by the trainees. Interobserver agreement in the jejunum was poor (observer 1/observer 2: κ=0.23; observer 1/observer 3: κ=-0.03) and in the ileum good (observer 1/observer 2: κ=0.78; observer 1/observer 3: κ=0.73). After training, evaluation of BWU (observer 2: 56%, P=0.22; observer 3: 44%, P=0.03), BWT (observer 2: 2; observer 3: 2), and interobserver agreement in the jejunum improved (observer 1/observer 2: κ=0.66; observer 1/observer 3: κ=0.66). However, the number of diagnosed fistulas and abscesses remained high. Conclusion: Before training, most findings of Crohn's disease in the terminal ileum were evaluated with high diagnostic performance by all readers. However, the inexperienced readers evaluated BWU with a low sensitivity and overestimated the number of FIS, number of ABS, and increased BWT in

  4. Diagnostic performance of quantitative shear wave elastography in the evaluation of solid breast masses: determination of the most discriminatory parameter.

    Science.gov (United States)

    Au, Frederick Wing-Fai; Ghai, Sandeep; Moshonov, Hadas; Kahn, Harriette; Brennan, Cressida; Dua, Hemi; Crystal, Pavel

    2014-09-01

    The purpose of this article is to assess the diagnostic performance of quantitative shear wave elastography in the evaluation of solid breast masses and to determine the most discriminatory parameter. B-mode ultrasound and shear wave elastography were performed before core biopsy of 123 masses in 112 women. The diagnostic performance of ultrasound and quantitative shear wave elastography parameters (mean elasticity, maximum elasticity, and elasticity ratio) were compared. The added effect of shear wave elastography on the performance of ultrasound was determined. The mean elasticity, maximum elasticity, and elasticity ratio were 24.8 kPa, 30.3 kPa, and 1.90, respectively, for 79 benign masses and 130.7 kPa, 154.9 kPa, and 11.52, respectively, for 44 malignant masses (p shear wave elastography parameter was higher than that of ultrasound (p shear wave elastography parameters to the evaluation of BI-RADS category 4a masses, about 90% of masses could be downgraded to BI-RADS category 3. The numbers of downgraded masses were 40 of 44 (91%) for mean elasticity, 39 of 44 (89%) for maximum elasticity, and 42 of 44 (95%) for elasticity ratio. The numbers of correctly downgraded masses were 39 of 40 (98%) for mean elasticity, 38 of 39 (97%) for maximum elasticity, and 41 of 42 (98%) for elasticity ratio. There was improvement in the diagnostic performance of ultrasound of mass assessment with shear wave elastography parameters added to BI-RADS category 4a masses compared with ultrasound alone. Combined ultrasound and elasticity ratio had the highest improvement, from 35.44% to 87.34% for specificity, from 45.74% to 80.77% for positive predictive value, and from 57.72% to 90.24% for accuracy (p shear wave elastography parameters of benign and malignant solid breast masses. By adding shear wave elastography parameters to BI-RADS category 4a masses, we found that about 90% of them could be correctly downgraded to BI-RADS category 3, thereby avoiding biopsy. Elasticity ratio

  5. STOL terminal area operating systems (aircraft and onboard avionics, ATC, navigation aids)

    Science.gov (United States)

    Burrous, C.; Erzberger, H.; Johnson, N.; Neuman, F.

    1974-01-01

    Operational procedures and systems onboard the STOL aircraft which are required to enable the aircraft to perform acceptably in restricted airspace in all types of atmospheric conditions and weather are discussed. Results of simulation and flight investigations to establish operational criteria are presented.

  6. Data systems and computer science space data systems: Onboard networking and testbeds

    Science.gov (United States)

    Dalton, Dan

    1991-01-01

    The technical objectives are to develop high-performance, space-qualifiable, onboard computing, storage, and networking technologies. The topics are presented in viewgraph form and include the following: justification; technology challenges; program description; and state-of-the-art assessment.

  7. Flight Hardware Virtualization for On-Board Science Data Processing

    Data.gov (United States)

    National Aeronautics and Space Administration — Utilize Hardware Virtualization technology to benefit on-board science data processing by investigating new real time embedded Hardware Virtualization solutions and...

  8. Performance of health laboratories in provision of HIV diagnostic and supportive services in selected districts of Tanzania.

    Science.gov (United States)

    Ishengoma, Deus S; Kamugisha, Mathias L; Rutta, Acleus S M; Kagaruki, Gibson B; Kilale, Andrew M; Kahwa, Amos; Kamugisha, Erasmus; Baraka, Vito; Mandara, Celine I; Materu, Godlisten S; Massaga, Julius J; Magesa, Stephen M; Lemnge, Martha M; Mboera, Leonard E G

    2017-01-23

    Roll-out and implementation of antiretroviral therapy (ART) necessitated many countries in Sub-Saharan Africa to strengthen their national health laboratory systems (NHLSs) to provide high quality HIV diagnostic and supportive services. This study was conducted to assess the performance of health laboratories in provision of HIV diagnostic and supportive services in eight districts (from four regions of Iringa, Mtwara, Tabora and Tanga), after nine years of implementation of HIV/AIDS care and treatment plan in Tanzania. In this cross-sectional study, checklists and observations were utilized to collect information from health facilities (HFs) with care and treatment centres (CTCs) for HIV/AIDS patients; on availability of laboratories, CTCs, laboratory personnel, equipment and reagents. A checklist was also used to collect information on implementation of quality assurance (QA) systems at all levels of the NHLS in the study areas. The four regions had 354 HFs (13 hospitals, 41 Health Centres (HCs) and 300 dispensaries); whereby all hospitals had laboratories and 11 had CTCs while 97.5 and 61.0% of HCs had both laboratories and CTCs, respectively. Of the dispensaries, 36.0 and 15.0% had laboratories and CTCs (mainly in urban areas). Thirty nine HFs (12 hospitals, 21 HCs and six dispensaries) were assessed and 56.4% were located in urban areas. The assessed HFs had 199 laboratory staff of different cadres (laboratory assistants = 35.7%; technicians =32.7%; attendants = 22.6%; and others = 9.1%); with >61% of the staff and 72.3% of the technicians working in urban areas. All laboratories were using rapid diagnostic tests for HIV testing. Over 74% of the laboratories were performing internal quality control and 51.4% were participating in external QA programmes. Regional and district laboratories had all key equipment and harmonization was maintained for Fluorescence-Activated Cell Sorting (FACS) machines. Most of the biochemical (58.0%) and haematological

  9. Performance assessment of patient dosimetry services and X-ray quality assurance instruments used in diagnostic radiology

    International Nuclear Information System (INIS)

    Green, S.; Palethrope, J.E.; Peach, D.; Bradley, D.A.

    1999-01-01

    Experiences of the Regional Radiation Physics and Protection Service (RRPPS) in performance assessment of diagnostic X-ray QA instrumentation and on-patient dosemeters are recounted. Issues relating to the provision of realistic and reproducible reference conditions for calibrated X-irradiations are considered and summary statistics from test measurements of dose and kVp meters are provided. For both dose and kVp meters it is indicated that as many as 25% of instruments used in routine use in the U.K. may require some adjustment before they can truly be said to be performing as the manufacturer intended. Results from intercomparison exercises for patient dosimetry services are also discussed. It is apparent that, for those centres participating in the exercise, dose assessments are generally being obtained to within a bias and a relative standard deviation of less then 10%

  10. Diagnostic performance of combined single photon emission computed tomographic scintimammography and ultrasonography based on computer-aided diagnosis for breast cancer

    International Nuclear Information System (INIS)

    Hwang, Kyung Hoon; Choi, Duck Joo; Choe, Won Sick; Lee, Jun Gu; Kim, Jong Hyo; Lee, Hyung Ji; Om, Kyong Sik; Lee, Byeong Il

    2007-01-01

    We investigated whether the diagnostic performance of SPECT scintimammography (SMM) can be improved by adding computer-aided diagnosis (CAD) of ultrasonography (US). We reviewed breast SPECT SMM images and corresponding US images from 40 patients with breast masses (21 malignant and 19 benign tumors.) The quantitative data of SPECT SMM were obtained as the uptake ratio of lesion to contralateral normal breast. The morphologic features of the breast lesions on US were extracted and quantitated using the automated CAD software program. The diagnostic performance of SPECT SMM and CAD of US alone was determined using receiver operating characteristic (ROC) curve analysis. The best discriminating parameter (D-value) combining SPECT SMM and the CAD of US was created. The sensitivity, specificity and accuracy of combined two diagnostic modalities were compared to those of a single one. Both SPECT SMM and CAD of US showed a relatively good diagnostic performance (area under curve=0.846 and 0.831, respectively). Combining the results of SPECT SMM and CAD of US resulted in improved diagnostic performance (area under curve=0.860), but there was no statistical difference in sensitivity, specificity and accuracy between the combined method and a single modality. It seems that combining the results of SPECT SMM and CAD of breast US do not significantly improve the diagnostic performance for diagnosis of breast cancer, compared with that of SPECT SMM alone. However, SPECT SMM and CAD of US may complement each other in differential diagnosis of breast cancer

  11. Estimation of waves and ship responses using onboard measurements

    DEFF Research Database (Denmark)

    Montazeri, Najmeh

    This thesis focuses on estimation of waves and ship responses using ship-board measurements. This is useful for development of operational safety and performance efficiency in connection with the broader concept of onboard decision support systems. Estimation of sea state is studied using a set...... of measured ship responses, a parametric description of directional wave spectra (a generalised JONSWAP model) and the transfer functions of the ship responses. The difference between the spectral moments of the measured ship responses and the corresponding theoretically calculated moments formulates a cost...... information. The model is tested on simulated data based on known unimodal and bimodal wave scenarios. The wave parameters in the output are then compared with the true wave parameters. In addition to the numerical experiments, two sets of full-scale measurements from container ships are analysed. Herein...

  12. Reconfigurable On-Board Vision Processing for Small Autonomous Vehicles

    Directory of Open Access Journals (Sweden)

    James K. Archibald

    2006-12-01

    Full Text Available This paper addresses the challenge of supporting real-time vision processing on-board small autonomous vehicles. Local vision gives increased autonomous capability, but it requires substantial computing power that is difficult to provide given the severe constraints of small size and battery-powered operation. We describe a custom FPGA-based circuit board designed to support research in the development of algorithms for image-directed navigation and control. We show that the FPGA approach supports real-time vision algorithms by describing the implementation of an algorithm to construct a three-dimensional (3D map of the environment surrounding a small mobile robot. We show that FPGAs are well suited for systems that must be flexible and deliver high levels of performance, especially in embedded settings where space and power are significant concerns.

  13. Reconfigurable On-Board Vision Processing for Small Autonomous Vehicles

    Directory of Open Access Journals (Sweden)

    Fife WadeS

    2007-01-01

    Full Text Available This paper addresses the challenge of supporting real-time vision processing on-board small autonomous vehicles. Local vision gives increased autonomous capability, but it requires substantial computing power that is difficult to provide given the severe constraints of small size and battery-powered operation. We describe a custom FPGA-based circuit board designed to support research in the development of algorithms for image-directed navigation and control. We show that the FPGA approach supports real-time vision algorithms by describing the implementation of an algorithm to construct a three-dimensional (3D map of the environment surrounding a small mobile robot. We show that FPGAs are well suited for systems that must be flexible and deliver high levels of performance, especially in embedded settings where space and power are significant concerns.

  14. Building Performance Optimization While Empowering Occupants towards Environmentally Sustainable Behavior through Continuous Monitoring and Diagnostics

    Science.gov (United States)

    2016-12-01

    transportation, and energy-related activities in an environmentally, economically, and fiscally sound manner. “To improve environmental performance...size, walls and windows insulation value). o Dynamic Variables: occupancy patterns, lighting system (technology and efficiency of the fixtures), and...during heating season. The survey asked questions about thermal, visual, acoustic , and air quality satisfaction levels; but only thermal and air quality

  15. Technical Performance Measurement, Earned Value, and Risk Management: An Integrated Diagnostic Tool for Program Management

    National Research Council Canada - National Science Library

    Pisano, N

    2002-01-01

    ...(A)), is known as the Navy PEO(A) Technical Performance Measurement (TPM) System. A retrospective analysis was conducted on the T45TS Cockpit-21 program and real-time test implementations are being conducted on the Federal Aviation Administration's (FAA...

  16. Myometrial invasion in endometrial cancer: diagnostic performance of diffusion-weighted MR imaging at 1.5-T

    International Nuclear Information System (INIS)

    Rechichi, Gilda; Sironi, Sandro; Galimberti, Stefania; Valsecchi, Maria Grazia; Signorelli, Mauro; Perego, Patrizia

    2010-01-01

    To determine the diagnostic accuracy of diffusion-weighted (DW) magnetic resonance (MR) imaging in the preoperative assessment of myometrial invasion by endometrial cancer. In this prospective study, 47 patients with histologically confirmed endometrial cancer underwent preoperative MR imaging and total hysterectomy. The MR protocol included spin-echo multishot T2-weighted, dynamic T1-weighted and DW images acquired with b-values of 0 and 500 s/mm 2 . Myometrial tumour spread was classified as superficial (<50%) or deep (≥50% myometrial thickness). Postoperative histopathological findings served as a reference standard. Indices of diagnostic performance were assessed for each sequence. At histopathological examination, superficial myometrial invasion was found in 34 patients and deep myometrial invasion in 13. In the assessment of tumour invasion, sensitivity, specificity, positive and negative predictive values of T2-weighted images were 92.3%, 76.5%, 60.0% and 96.3%, respectively. The corresponding values for dynamic images were 69.2%, 61.8%, 40.9% and 84.0%, and for DW images 84.6%, 70.6%, 52.4% and 92.3%. T2-weighted and DW imaging proved to be the most accurate techniques for tumour spread determination. DW imaging proved to be accurate in assessing myometrial invasion, and it could replace dynamic imaging as an adjunct to routine T2-weighted imaging for preoperative evaluation of endometrial cancer. (orig.)

  17. Performance of Rapid Diagnostic Tests for Imported Malaria in Clinical Practice: Results of a National Multicenter Study

    Science.gov (United States)

    Houzé, Sandrine; Boutron, Isabelle; Marmorat, Anne; Dalichampt, Marie; Choquet, Christophe; Poilane, Isabelle; Godineau, Nadine; Le Guern, Anne-Sophie; Thellier, Marc; Broutier, Hélène; Fenneteau, Odile; Millet, Pascal; Dulucq, Stéphanie; Hubert, Véronique; Houzé, Pascal; Tubach, Florence; Le Bras, Jacques; Matheron, Sophie

    2013-01-01

    We compared the performance of four rapid diagnostic tests (RDTs) for imported malaria, and particularly Plasmodium falciparum infection, using thick and thin blood smears as the gold standard. All the tests are designed to detect at least one protein specific to P. falciparum ( Plasmodium histidine-rich protein 2 (PfHRP2) or Plasmodium LDH (PfLDH)) and one pan-Plasmodium protein (aldolase or Plasmodium LDH (pLDH)). 1,311 consecutive patients presenting to 9 French hospitals with suspected malaria were included in this prospective study between April 2006 and September 2008. Blood smears revealed malaria parasites in 374 cases (29%). For the diagnosis of P. falciparum infection, the three tests detecting PfHRP2 showed high and similar sensitivity (96%), positive predictive value (PPV) (90%) and negative predictive value (NPV) (98%). The PfLDH test showed lower sensitivity (83%) and NPV (80%), despite good PPV (98%). For the diagnosis of non-falciparum species, the PPV and NPV of tests targeting pLDH or aldolase were 94–99% and 52–64%, respectively. PfHRP2-based RDTs are thus an acceptable alternative to routine microscopy for diagnosing P. falciparum malaria. However, as malaria may be misdiagnosed with RDTs, all negative results must be confirmed by the reference diagnostic method when clinical, biological or other factors are highly suggestive of malaria. PMID:24098699

  18. Diagnostic performance of dental students in identifying mandibular condyle fractures by panoramic radiography and the usefulness of reference images

    International Nuclear Information System (INIS)

    Cho, Bong Hae

    2011-01-01

    The purpose of this study was to evaluate the diagnostic performance of dental students in detection of mandibular condyle fractures and the effectiveness of reference panoramic images. Forty-six undergraduates evaluated 25 panoramic radiographs for condylar fractures and the data were analyzed through receiver operating characteristic (ROC) analysis. After a month, they were divided into two homogeneous groups based on the first results and re-evaluated the images with (group A) or without (group B) reference images. Eight reference images included indications showing either typical condylar fractures or anatomic structures which could be confused with fractures. Paired t-test was used for statistical analysis of the difference between the first and the second evaluations for each group, and student's t-test was used between the two groups in the second evaluation. The intra- and inter-observer agreements were evaluated with Kappa statistics. Intra- and inter-observer agreements were substantial (k=0.66) and moderate (k=0.53), respectively. The area under the ROC curve (Az) in the first evaluation was 0.802. In the second evaluation, it was increased to 0.823 for group A and 0.814 for group B. The difference between the first and second evaluations for group A was statistically significant (p<0.05), however there was no statistically significant difference between the two groups in the second evaluation. Providing reference images to less experienced clinicians would be a good way to improve the diagnostic ability in detecting condylar fracture.

  19. Diagnostic performance of placental alpha-microglobulin-1 test in women with prolonged pre-labour rupture of membranes.

    Science.gov (United States)

    Eleje, George Uchenna; Ezugwu, Euzebus Chinonye; Eke, Ahizechukwu Chigoziem; Eleje, Lydia Ijeoma; Ikechebelu, Joseph Ifeanyichukwu; Afiadigwe, Evaristus Anthony; Ezugwu, Frank O; Udigwe, Gerald Okanandu; Okafor, Charles I; Ezeama, Chukwuemeka Okwudili

    2016-01-01

    To determine diagnostic performance of placental alpha-microglobulin-1 (PAMG-1) test compared to conventional clinical assessment (CCA) in women with prolonged pre-labour rupture of membranes (PROM). A double-blind study of women with symptoms and signs of PROM in Nnamdi Azikiwe University Teaching Hospital, Nnewi and University of Nigeria Teaching Hospital, Enugu, in south-east Nigeria using CCA for PROM and PAMG-1 test was done. Women were included if their symptoms, signs or complaints suggestive of PROM was more than 24 h duration. PROM was diagnosed if two out of three methods from CCA (pooling, positive nitrazine test or ferning) were present. Confirmation of PROM was done after delivery using any two of these clinical criteria: delivery in 48 h to 7 days, evidence of chorioamnionitis, membranes obviously ruptured at delivery and adverse perinatal outcomes strongly correlated with prolonged PROM. Accuracy, specificity and sensitivity value for CCA were 72.5, 36.8 and 86.0% lower than for PAMG-1 test which were 95.7, 94.1 and 96.2%. In equivocal cases, PAMG-1 was significantly more accurate than CCA (92.3% versus 38.5%; p < 0.001). This study in women with prolonged PROM, confirms that PAMG-1 test has high diagnostic accuracy irrespective of the duration of PROM before clinical evaluation.

  20. Performance Validity Testing in Neuropsychology: Methods for Measurement Development and Maximizing Diagnostic Accuracy.

    Science.gov (United States)

    Wodushek, Thomas R; Greher, Michael R

    2017-05-01

    In the first column in this 2-part series, Performance Validity Testing in Neuropsychology: Scientific Basis and Clinical Application-A Brief Review, the authors introduced performance validity tests (PVTs) and their function, provided a justification for why they are necessary, traced their ongoing endorsement by neuropsychological organizations, and described how they are used and interpreted by ever increasing numbers of clinical neuropsychologists. To enhance readers' understanding of these measures, this second column briefly describes common detection strategies used in PVTs as well as the typical methods used to validate new PVTs and determine cut scores for valid/invalid determinations. We provide a discussion of the latest research demonstrating how neuropsychologists can combine multiple PVTs in a single battery to improve sensitivity/specificity to invalid responding. Finally, we discuss future directions for the research and application of PVTs.

  1. [Performances and place of sonography in the diagnostic of endometriosis: CNGOF-HAS Endometriosis Guidelines].

    Science.gov (United States)

    Philip, C-A; Dubernard, G

    2018-03-01

    Endometriosis is difficult to diagnose clinically. Transvaginal sonography (TVS) is a procedure that is known to be operator-dependent, which mean that published evidences has to be balanced with the level of the sonographer that produced the data. The objective of this publication was to assess the performances of the sonography in the diagnosis of endometriosis in order to establish the French national recommendations. We searched the MEDLINE database for publication from January 2000 to September 2017 using keywords associated with endometriosis and sonography. Eighty-four trial and reviews published in English or French were included. Ovarian endometrioma can usually be diagnosed by a non-expert sonographer, especially when its aspect is typical. In case of an ovarian cyst with atypical presentation, it is recommended to control the sonography by a referent or to perform an MRI. In menopaused women, any ovarian cyst should be considered as a cancer until proven otherwise. In the diagnosis of posterior deep invasive endometriosis (DIE), TVS with sensitivity and specificity of 96 and 99% respectively, seems at least equivalent if not superior to MRI. However, these performances are related to expert sonographers. To reach sufficient efficiency in posterior DIE, the estimated learning curve for a sonographer is 44 cases. When posterior DIE is suspected, we recommend proposing a TVS "performed by an expert" or a MRI "at least interpreted by an expert". In anterior DIE, TVS has a good specificity (100%), but its sensitivity is poor in the literature (64%). TVS is therefore not able to eliminate the diagnosis. However a renal ultrasound should be proposed each time a urinary endometriosis is confirmed, and should be considered whenever posterior DIE is diagnosed especially the lesion is superior to 3cm. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

  2. The Thermal Infrared Sensor onboard NASA's Mars 2020 Mission

    Science.gov (United States)

    Martinez, G.; Perez-Izquierdo, J.; Sebastian, E.; Ramos, M.; Bravo, A.; Mazo, M.; Rodriguez-Manfredi, J. A.

    2017-12-01

    NASA's Mars 2020 rover mission is scheduled for launch in July/August 2020 and will address key questions about the potential for life on Mars. The Mars Environmental Dynamics Analyzer (MEDA) is one of the seven instruments onboard the rover [1] and has been designed to assess the environmental conditions across the rover traverse. MEDA will extend the current record of in-situ meteorological measurements at the surface [2] to other locations on Mars. The Thermal InfraRed Sensor (TIRS) [3] is one of the six sensors comprising MEDA. TIRS will use three downward-looking channels to measure (1) the surface skin temperature (with high heritage from the Rover Environmental Monitoring Station onboard the Mars Science Laboratory mission [4]), (2) the upwelling thermal infrared radiation from the surface and (3) the reflected solar radiation at the surface, and two upward-looking channels to measure the (4) downwelling thermal infrared radiation at the surface and (5) the atmospheric temperature. In combination with other MEDA's sensors, TIRS will allow the quantification of the surface energy budget [5] and the determination of key geophysical properties of the terrain such as the albedo and thermal inertia with an unprecedented spatial resolution. Here we present a general description of the TIRS, with focus on its scientific requirements and results from field campaigns showing the performance of the different channels. References:[1] Rodríguez-Manfredi, J. A. et al. (2014), MEDA: An environmental and meteorological package for Mars 2020, LPSC, 45, 2837. [2] Martínez, G.M. et al. (2017), The Modern Near-Surface Martian Climate: A Review of In-situ Meteorological Data from Viking to Curiosity, Space Science Reviews, 1-44. [3] Pérez-Izquierdo, J. et al. (2017), The Thermal Infrared Sensor (TIRS) of the Mars Environmental Dynamics Analyzer (MEDA) Instrument onboard Mars 2020, IEEE. [4] Sebastián, E. et al. (2010), The Rover Environmental Monitoring Station Ground

  3. Multispectral Video-Microscope Modified for Skin Diagnostics

    Directory of Open Access Journals (Sweden)

    Rubins U.

    2014-12-01

    Full Text Available Commercial DinoLite AD413 digital microscope was modified for skin diagnostics purposes. The original LED ring (4 white and 4 ultraviolet light emitters of microscope was replaced by a custom-designed 16-LED ring module consisting of four LED groups (450, 545, 660 and 940 nm, and an onboard LED controller with USB hub was added. The video acquisition and LED switching are performed using custom-designed Matlab software which provides real-time spectral analysis of multi-spectral images and calculation of skin chromophore optical density. The developed multispectral video-microscope is mainly meant for diagnostics of skin malformations, e.g. skin cancerous lesions.

  4. On-board processing of video image sequences

    DEFF Research Database (Denmark)

    Andersen, Jakob Dahl; Chanrion, Olivier Arnaud; Forchhammer, Søren

    2008-01-01

    and evaluated. On-board there are six video cameras each capturing images of 1024times1024 pixels of 12 bpp at a frame rate of 15 fps, thus totalling 1080 Mbits/s. In comparison the average downlink data rate for these images is projected to be 50 kbit/s. This calls for efficient on-board processing to select...

  5. Defense Threat Reduction Agency > Careers > Onboarding > Special Programs

    Science.gov (United States)

    Development Work/Life Programs Onboarding Onboarding Overview Before You Report Sponsor Program Getting Here , programs, and practices to help our employees and Service members balance work and family responsibilities . We have put in place family-friendly Work/Life programs and policies designed to create a more

  6. Virtual microscopy: an evaluation of its validity and diagnostic performance in routine histologic diagnosis of skin tumors

    DEFF Research Database (Denmark)

    Nielsen, Patricia Switten; Lindebjerg, Jan; Rasmussen, Jan

    2010-01-01

    Digitization of histologic slides is associated with many advantages, and its use in routine diagnosis holds great promise. Nevertheless, few articles evaluate virtual microscopy in routine settings. This study is an evaluation of the validity and diagnostic performance of virtual microscopy...... in routine histologic diagnosis of skin tumors. Our aim is to investigate whether conventional microscopy of skin tumors can be replaced by virtual microscopy. Ninety-six skin tumors and skin-tumor-like changes were consecutively gathered over a 1-week period. Specimens were routinely processed, and digital...... slides were captured on Mirax Scan (Carl Zeiss MicroImaging, Göttingen, Germany). Four pathologists evaluated the 96 virtual slides and the associated 96 conventional slides twice with intermediate time intervals of at least 3 weeks. Virtual slides that caused difficulties were reevaluated to identify...

  7. Analysis and Performance of the Thomson Scattering Diagnostics on HT-7 Tokamak Based on I-EMCCD

    International Nuclear Information System (INIS)

    Shao Chunqiang; Zhao Junyu; Zang Qing; Han Xiaofeng; Xi Xiaoqi; Yang Jianhua; Chen Hui; Hu Ailan

    2014-01-01

    A visible light imaging Thomson scattering (VIS-TVTS) diagnostic system has been developed for the measurement of plasma electron temperature on the HT-7 tokamak. The system contains a Nd:YAG laser (λ = 532 nm, repetition rate 10 Hz, total pulse duration ≍ 10 ns, pulse energy > 1.0 J), a grating spectrometer, an image intensifier (I.I.) lens coupled with an electron multiplying CCD (EMCCD) and a data acquisition and analysis system. In this paper, the measurement capability of the system is analyzed. In addition to the performance of the system, the capability of measuring plasma electron temperature has been proved. The profile of electron temperature is presented with a spatial resolution of about 0.96 cm (seven points) near the center of the plasma

  8. Data-Driven Anomaly Detection Performance for the Ares I-X Ground Diagnostic Prototype

    Science.gov (United States)

    Martin, Rodney A.; Schwabacher, Mark A.; Matthews, Bryan L.

    2010-01-01

    In this paper, we will assess the performance of a data-driven anomaly detection algorithm, the Inductive Monitoring System (IMS), which can be used to detect simulated Thrust Vector Control (TVC) system failures. However, the ability of IMS to detect these failures in a true operational setting may be related to the realistic nature of how they are simulated. As such, we will investigate both a low fidelity and high fidelity approach to simulating such failures, with the latter based upon the underlying physics. Furthermore, the ability of IMS to detect anomalies that were previously unknown and not previously simulated will be studied in earnest, as well as apparent deficiencies or misapplications that result from using the data-driven paradigm. Our conclusions indicate that robust detection performance of simulated failures using IMS is not appreciably affected by the use of a high fidelity simulation. However, we have found that the inclusion of a data-driven algorithm such as IMS into a suite of deployable health management technologies does add significant value.

  9. Combining principles of Cognitive Load Theory and diagnostic error analysis for designing job aids: Effects on motivation and diagnostic performance in a process control task.

    Science.gov (United States)

    Kluge, Annette; Grauel, Britta; Burkolter, Dina

    2013-03-01

    Two studies are presented in which the design of a procedural aid and the impact of an additional decision aid for process control were assessed. In Study 1, a procedural aid was developed that avoids imposing unnecessary extraneous cognitive load on novices when controlling a complex technical system. This newly designed procedural aid positively affected germane load, attention, satisfaction, motivation, knowledge acquisition and diagnostic speed for novel faults. In Study 2, the effect of a decision aid for use before the procedural aid was investigated, which was developed based on an analysis of diagnostic errors committed in Study 1. Results showed that novices were able to diagnose both novel faults and practised faults, and were even faster at diagnosing novel faults. This research contributes to the question of how to optimally support novices in dealing with technical faults in process control. Copyright © 2012 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  10. Prevalence and Diagnostic Performance of Isolated and Combined NEXUS Chest CT Decision Criteria.

    Science.gov (United States)

    Raja, Ali S; Mower, William R; Nishijima, Daniel K; Hendey, Gregory W; Baumann, Brigitte M; Medak, Anthony J; Rodriguez, Robert M

    2016-08-01

    The use of chest computed tomography (CT) to evaluate emergency department patients with adult blunt trauma is rising. The NEXUS Chest CT decision instruments are highly sensitive identifiers of adult blunt trauma patients with thoracic injuries. However, many patients without injury exhibit one of more of the criteria so cannot be classified "low risk." We sought to determine screening performance of both individual and combined NEXUS Chest CT criteria as predictors of thoracic injury to inform chest CT imaging decisions in "non-low-risk" patients. This was a secondary analysis of data on patients in the derivation and validation cohorts of the prospective, observational NEXUS Chest CT study, performed September 2011 to May 2014 in 11 Level I trauma centers. Institutional review board approval was obtained at all study sites. Adult blunt trauma patients receiving chest CT were included. The primary outcome was injury and major clinical injury prevalence and screening performance in patients with combinations of one, two, or three of seven individual NEXUS Chest CT criteria. Across the 11 study sites, rates of chest CT performance ranged from 15.5% to 77.2% (median = 43.6%). We found injuries in 1,493/5,169 patients (28.9%) who had chest CT; 269 patients (5.2%) had major clinical injury (e.g., pneumothorax requiring chest tube). With sensitivity of 73.7 (95% confidence interval [CI] = 68.1 to 78.6) and specificity of 83.9 (95% CI = 83.6 to 84.2) for major clinical injury, abnormal chest-x-ray (CXR) was the single most important screening criterion. When patients had only abnormal CXR, injury and major clinical injury prevalences were 60.7% (95% CI = 52.2% to 68.6%) and 12.9% (95% CI = 8.3% to 19.4%), respectively. Injury and major clinical injury prevalences when any other single criterion alone (other than abnormal CXR) was present were 16.8% (95% CI = 15.2% to 18.6%) and 1.1% (95% CI = 0.1% to 1.8%), respectively. Injury and major clinical injury prevalences

  11. Comparison of Diagnostic Performance of US Elastography and Conventional B-mode US in Differentiation of Breast Lesions

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Ji Young; Lee, Jin Hwa; Cho, Jin Han; Ha, Dong Ho; Park, Byeong Ho; Choi, Sun Seob [Dept. of Radiology, Dong-A University College of Medicine, Busan (Korea, Republic of); Kim, Eun Kyung [Dept. of Radiology, Yonsei University College of Medicine, Seoul (Korea, Republic of); Shin, Su Young [Dept. of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Kim, Byeong Ho [Dept. of Preventive Medicine, Dong-A University College of Medicine, Busan (Korea, Republic of)

    2012-08-15

    The purpose of this study was to compare the diagnostic performance of ultrasound (US) elastography and conventional B-mode US for discrimination between benign and malignant breast lesions. During a 13-month period, 277 women with 335 sonographically visible breast lesions who were scheduled to undergo biopsy were examined with US elastography. Elastographic findings were classified as benign or malignant based on the area ratio, with 1.00 as the threshold. Findings on conventional B mode US were classified according to the BI-RADS category, as follows: lesions of BIRADS categories 2 and 3 were considered benign, while those in categories 4 and 5 were considered malignant. Statistical analysis included sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy, and ROC curve analysis for comparison of the diagnostic performance of US elastography and conventional B-mode US. Of the 335 breast lesions, 85 (25.4%) showed malignancy on pathology. Findings on B-mode US showed malignancy in 264 (78.8%) and elastographic findings showed malignancy in 102 (30.4%). The sensitivity, specificity, PPV, NPV, and accuracy of B-mode US and elastography were 98.8%, 28.0%, 31.8%, 98.6%, and 79.4% and 69.4%, 81.2%, 57.8%, 88.8%, and 79.4%, respectively. Elastography showed significantly higher specificity and PPV and lower sensitivity and NPV, compared with B-mode US (p < 0.001). The area under the ROC curve (AUC value) was 0.761 for elastography, and 0.634 for B-mode US (p < 0.001). US elastography can improve specificity and PPV of B-mode US, but with significant sacrifice of sensitivity and NPV. Therefore, US elastography may complement B-mode US for differentiation of breast masses.

  12. Detection of parathyroid adenomas using a monophasic dual-energy computed tomography acquisition: diagnostic performance and potential radiation dose reduction

    International Nuclear Information System (INIS)

    Leiva-Salinas, Carlos; Flors, Lucia; Durst, Christopher R.; Hou, Qinghua; Mukherjee, Sugoto; Patrie, James T.; Wintermark, Max

    2016-01-01

    The aims of the study were to compare the diagnostic performance of a combination of virtual non-contrast (VNC) images and arterial images obtained from a single-phase dual-energy CT (DECT) acquisition and standard non-contrast and arterial images from a biphasic protocol and to study the potential radiation dose reduction of the former approach. All DECT examinations performed for evaluation of parathyroid adenomas during a 13-month period were retrospectively reviewed. An initial single-energy unenhanced acquisition was followed by a dual-energy arterial phase acquisition. ''Virtual non-contrast images'' were generated from the dual-energy acquisition. Two independent and blinded radiologists evaluated three different sets of images during three reading sessions: single arterial phase, single-phase DECT (virtual non-contrast and arterial phase), and standard biphasic protocol (true non-contrast and arterial phase). The accuracy of interpretation in lateralizing an adenoma to the side of the neck and localizing it to a quadrant in the neck was evaluated. Sixty patients (mean age, 65.5 years; age range, 38-87 years) were included in the study. The lateralization and localization accuracy, sensitivity, and positive predicted value (PPV) and negative predicted value (NPV) of the different image datasets were comparable. The combination of VNC and arterial images was more specific than arterial images alone to lateralize a parathyroid lesion (OR = 1.93, p = 0.043). The use of the single-phase protocol resulted in a calculated radiation exposure reduction of 52.8 %. Virtual non-contrast and arterial images from a single DECT acquisition showed similar diagnostic accuracy than a biphasic protocol, providing a significant dose reduction. (orig.)

  13. Detection of parathyroid adenomas using a monophasic dual-energy computed tomography acquisition: diagnostic performance and potential radiation dose reduction

    Energy Technology Data Exchange (ETDEWEB)

    Leiva-Salinas, Carlos; Flors, Lucia; Durst, Christopher R.; Hou, Qinghua; Mukherjee, Sugoto [University of Virginia, Department of Radiology, Division of Neuroradiology, Charlottesville, VA (United States); Patrie, James T. [University of Virginia, Department of Public Health Sciences, Charlottesville, VA (United States); Wintermark, Max [Stanford University, Department of Radiology, Palo Alto, CA (United States)

    2016-11-15

    The aims of the study were to compare the diagnostic performance of a combination of virtual non-contrast (VNC) images and arterial images obtained from a single-phase dual-energy CT (DECT) acquisition and standard non-contrast and arterial images from a biphasic protocol and to study the potential radiation dose reduction of the former approach. All DECT examinations performed for evaluation of parathyroid adenomas during a 13-month period were retrospectively reviewed. An initial single-energy unenhanced acquisition was followed by a dual-energy arterial phase acquisition. ''Virtual non-contrast images'' were generated from the dual-energy acquisition. Two independent and blinded radiologists evaluated three different sets of images during three reading sessions: single arterial phase, single-phase DECT (virtual non-contrast and arterial phase), and standard biphasic protocol (true non-contrast and arterial phase). The accuracy of interpretation in lateralizing an adenoma to the side of the neck and localizing it to a quadrant in the neck was evaluated. Sixty patients (mean age, 65.5 years; age range, 38-87 years) were included in the study. The lateralization and localization accuracy, sensitivity, and positive predicted value (PPV) and negative predicted value (NPV) of the different image datasets were comparable. The combination of VNC and arterial images was more specific than arterial images alone to lateralize a parathyroid lesion (OR = 1.93, p = 0.043). The use of the single-phase protocol resulted in a calculated radiation exposure reduction of 52.8 %. Virtual non-contrast and arterial images from a single DECT acquisition showed similar diagnostic accuracy than a biphasic protocol, providing a significant dose reduction. (orig.)

  14. [Feasibility and diagnostic value of hysterosonography performed in bleeding time in the exploration of abnormal uterine bleeding].

    Science.gov (United States)

    Bouzid, A; Ayachi, A; Ben Khedija, M; Menjli, S; Mkaouar, L; Mourali, M

    2016-11-01

    The aim of our study is to evaluate the feasibility, safety and diagnostic value of hysterosonography performed in an emergency setting among patients consulting for active abnormal uterine bleeding. In this prospective study, we included 216 patients visiting our emergency department for abnormal uterine bleeding. All patients had a transvaginal ultrasound with doppler study and an hysterosonography. Secondly, the patients, in whom we diagnosed a suspected organic lesion, were addressed to an endoscopic or surgical procedure with pathological examination. Initially, we evaluated the feasibility and the safety of hysterosonography and secondly, we compared the two techniques (EEV and hysterosonography), sensitivity, specificity, LHR+and LHR-. The hysterosonography was performed in 98.1 % of patients and its realization has resulted in an additional period of 1.2minutes on average (extreme: 6-12) compared to ultrasound. The tolerance of the hysterosonographic examination was very good in 73.5 % of patients and good in 23.1 % of them. For the 167 patients who had been diagnosed with presumed organic lesions, pathological examination found an endometrial hyperplasia in 34.7 % of cases, polyps in 40.1 % of cases, sub-mucosal fibroids in 11.3 % of cases, endometrial cancer in 0.7 % of cases and other lesions in 13.2 % of cases. The diagnostic value of hysterosonography was superior to ultrasound in the detection of polyps (AUC: 0.894 vs 0.778, P=0.003) and fibromas (AUC: 1.000 vs 0.716, P=0.001) while the two methods showed no significant difference in the detection of hyperplasia. The purpose of our study was to focus on a particular context of use of the hysterosonography consisting on hemorrhagic period and on its realization in the emergency room. We were able to demonstrate that hysterosonography is compatible with the emergency situation as to its feasibility and its diagnostic value and that its realization would contribute to the sorting of patients

  15. An instrument to perform automated quality assurance and patient dosimetry in diagnostic radiology

    International Nuclear Information System (INIS)

    Chapple, C.-L.; Faulkner, K.

    1992-01-01

    A computerised method of automatically monitoring tube and generator parameters to perform on-line quality assurance and patient dosimetry has been developed. A microcomputer has been interfaced to a microprocessor controlled X ray generator and dose-area product meter. The instrument prompts the operator to enter details of the examination and projection before an examination is made. The field size and dose-area product are monitored by the instrument. These data, together with information on the tube potential are used to deduce the patient entrance dose and energy imparted. Organ doses are estimated using normalised organ dose data. The accuracy and reproducibility of the instrument were investigated. Doses measured in a Rando phantom were compared with calculations made by the instrument. The instrument will compare various measured quality assurance parameters against their nominal values. The implications of this instrument for both patient dosimetry studies and effective continuous quality assurance are discussed. (author)

  16. How to improve the standardization and the diagnostic performance of the fecal egg count reduction test?

    DEFF Research Database (Denmark)

    Levecke, Bruno; Kaplan, Ray M.; Thamsborg, Stig M.

    2018-01-01

    Although various studies have provided novel insights into how to best design, analyze and interpret a fecal egg count reduction test (FECRT), it is still not straightforward to provide guidance that allows improving both the standardization and the analytical performance of the FECRT across...... a variety of both animal and nematode species. For example, it has been suggested to recommend a minimum number of eggs to be counted under the microscope (not eggs per gram of feces), but we lack the evidence to recommend any number of eggs that would allow a reliable assessment of drug efficacy. Other...... the UI methodology that yields the most reliable assessment of drug efficacy (coverage of TDE) and detection of reduced drug efficacy, and (iii) to determine the required sample size and number of eggs counted under the microscope that optimizes the detection of reduced efficacy. Our results confirm...

  17. Diagnostic performance of {sup 18}F-dihydroxyphenylalanine positron emission tomography in patients with paraganglioma: a meta-analysis

    Energy Technology Data Exchange (ETDEWEB)

    Treglia, Giorgio; Cocciolillo, Fabrizio; Castaldi, Paola; Rufini, Vittoria; Giordano, Alessandro [Catholic University of the Sacred Heart, Institute of Nuclear Medicine, Rome (Italy); De Waure, Chiara; Di Nardo, Francesco; Gualano, Maria Rosaria [Catholic University of the Sacred Heart, Institute of Hygiene, Rome (Italy)

    2012-07-15

    The aim of this study was to systematically review and conduct a meta-analysis of published data about the diagnostic performance of {sup 18}F-dihydroxyphenylalanine (DOPA) positron emission tomography (PET) in patients with paraganglioma (PG). A comprehensive computer literature search of studies published through 30 June 2011 regarding {sup 18}F-DOPA PET or PET/computed tomography (PET/CT) in patients with PG was performed in PubMed/MEDLINE, Embase and Scopus databases. Pooled sensitivity and specificity of {sup 18}F-DOPA PET or PET/CT in patients with PG on a per patient- and on a per lesion-based analysis were calculated. The area under the receiver-operating characteristic (ROC) curve was calculated to measure the accuracy of {sup 18}F-DOPA PET or PET/CT in patients with PG. Furthermore, a sub-analysis taking into account the different genetic mutations in PG patients was also performed. Eleven studies comprising 275 patients with suspected PG were included in this meta-analysis. The pooled sensitivity of {sup 18}F-DOPA PET and PET/CT in detecting PG was 91% [95% confidence interval (CI) 87-94%] on a per patient-based analysis and 79% (95% CI 76-81%) on a per lesion-based analysis. The pooled specificity of {sup 18}F-DOPA PET and PET/CT in detecting PG was 95% (95% CI 86-99%) on a per patient-based analysis and 95% (95% CI 84-99%) on a per lesion-based analysis. The area under the ROC curve was 0.95 on a per patient- and 0.94 on a per lesion-based analysis. Heterogeneity between the studies about sensitivity of {sup 18}F-DOPA PET or PET/CT was found. A significant increase in sensitivity of {sup 18}F-DOPA PET or PET/CT was observed when a sub-analysis excluding patients with succinate dehydrogenase subunit B (SDHB) gene mutations was performed. In patients with suspected PG {sup 18}F-DOPA PET or PET/CT demonstrated high sensitivity and specificity. {sup 18}F-DOPA PET or PET/CT are accurate methods in this setting. Nevertheless, possible sources of false

  18. Diagnostic performance of 18F-dihydroxyphenylalanine positron emission tomography in patients with paraganglioma: a meta-analysis

    International Nuclear Information System (INIS)

    Treglia, Giorgio; Cocciolillo, Fabrizio; Castaldi, Paola; Rufini, Vittoria; Giordano, Alessandro; De Waure, Chiara; Di Nardo, Francesco; Gualano, Maria Rosaria

    2012-01-01

    The aim of this study was to systematically review and conduct a meta-analysis of published data about the diagnostic performance of 18 F-dihydroxyphenylalanine (DOPA) positron emission tomography (PET) in patients with paraganglioma (PG). A comprehensive computer literature search of studies published through 30 June 2011 regarding 18 F-DOPA PET or PET/computed tomography (PET/CT) in patients with PG was performed in PubMed/MEDLINE, Embase and Scopus databases. Pooled sensitivity and specificity of 18 F-DOPA PET or PET/CT in patients with PG on a per patient- and on a per lesion-based analysis were calculated. The area under the receiver-operating characteristic (ROC) curve was calculated to measure the accuracy of 18 F-DOPA PET or PET/CT in patients with PG. Furthermore, a sub-analysis taking into account the different genetic mutations in PG patients was also performed. Eleven studies comprising 275 patients with suspected PG were included in this meta-analysis. The pooled sensitivity of 18 F-DOPA PET and PET/CT in detecting PG was 91% [95% confidence interval (CI) 87-94%] on a per patient-based analysis and 79% (95% CI 76-81%) on a per lesion-based analysis. The pooled specificity of 18 F-DOPA PET and PET/CT in detecting PG was 95% (95% CI 86-99%) on a per patient-based analysis and 95% (95% CI 84-99%) on a per lesion-based analysis. The area under the ROC curve was 0.95 on a per patient- and 0.94 on a per lesion-based analysis. Heterogeneity between the studies about sensitivity of 18 F-DOPA PET or PET/CT was found. A significant increase in sensitivity of 18 F-DOPA PET or PET/CT was observed when a sub-analysis excluding patients with succinate dehydrogenase subunit B (SDHB) gene mutations was performed. In patients with suspected PG 18 F-DOPA PET or PET/CT demonstrated high sensitivity and specificity. 18 F-DOPA PET or PET/CT are accurate methods in this setting. Nevertheless, possible sources of false-negative results should be kept in mind. Furthermore

  19. Diagnostic performance of 18F-dihydroxyphenylalanine positron emission tomography in patients with paraganglioma: a meta-analysis.

    Science.gov (United States)

    Treglia, Giorgio; Cocciolillo, Fabrizio; de Waure, Chiara; Di Nardo, Francesco; Gualano, Maria Rosaria; Castaldi, Paola; Rufini, Vittoria; Giordano, Alessandro

    2012-07-01

    The aim of this study was to systematically review and conduct a meta-analysis of published data about the diagnostic performance of (18)F-dihydroxyphenylalanine (DOPA) positron emission tomography (PET) in patients with paraganglioma (PG). A comprehensive computer literature search of studies published through 30 June 2011 regarding (18)F-DOPA PET or PET/computed tomography (PET/CT) in patients with PG was performed in PubMed/MEDLINE, Embase and Scopus databases. Pooled sensitivity and specificity of (18)F-DOPA PET or PET/CT in patients with PG on a per patient- and on a per lesion-based analysis were calculated. The area under the receiver-operating characteristic (ROC) curve was calculated to measure the accuracy of (18)F-DOPA PET or PET/CT in patients with PG. Furthermore, a sub-analysis taking into account the different genetic mutations in PG patients was also performed. Eleven studies comprising 275 patients with suspected PG were included in this meta-analysis. The pooled sensitivity of (18)F-DOPA PET and PET/CT in detecting PG was 91% [95% confidence interval (CI) 87-94%] on a per patient-based analysis and 79% (95% CI 76-81%) on a per lesion-based analysis. The pooled specificity of (18)F-DOPA PET and PET/CT in detecting PG was 95% (95% CI 86-99%) on a per patient-based analysis and 95% (95% CI 84-99%) on a per lesion-based analysis. The area under the ROC curve was 0.95 on a per patient- and 0.94 on a per lesion-based analysis. Heterogeneity between the studies about sensitivity of (18)F-DOPA PET or PET/CT was found. A significant increase in sensitivity of (18)F-DOPA PET or PET/CT was observed when a sub-analysis excluding patients with succinate dehydrogenase subunit B (SDHB) gene mutations was performed. In patients with suspected PG (18)F-DOPA PET or PET/CT demonstrated high sensitivity and specificity. (18)F-DOPA PET or PET/CT are accurate methods in this setting. Nevertheless, possible sources of false-negative results should be kept in mind

  20. Instrumentation Of The CERN Accelerator Logging Service: Ensuring Performance, Scalability, Maintenance And Diagnostics

    CERN Document Server

    Roderick, C; Dinis Teixeira, D

    2011-01-01

    The CERN accelerator Logging Service currently holds more than 90 terabytes of data online, and processes approximately 450 gigabytes per day, via hundreds of data loading processes and data extraction requests. This service is mission-critical for day-to-day operations, especially with respect to the tracking of live data from the LHC beam and equipment. In order to effectively manage any service, the service provider’s goals should include knowing how the underlying systems are being used, in terms of: “Who is doing what, from where, using which applications and methods, and how long each action takes”. Armed with such information, it is then possible to: analyse and tune system performance over time; plan for scalability ahead of time; assess the impact of maintenance operations and infrastructure upgrades; diagnose past, on-going, or re-occurring problems. The Logging Service is based on Oracle DBMS and Application Servers, and Java technology, and is comprised of several layered and multi-tiered s...

  1. Correlation between the physical performances measured from detectors and the diagnostic image quality in digital mammography

    International Nuclear Information System (INIS)

    Perez-Ponce, H.

    2009-05-01

    In digital mammography two approaches exist to estimate image quality. In the first approach, human observer assesses the lesion detection in mammograms. Unfortunately, such quality assessment is subject to interobserver variability, and requires a large amount of time and human resources. In the second approach, objective and human-independent parameters relating to image spatial resolution and noise (MTF and NPS) are used to evaluate digital detector performance; even if these parameters are objective, they are not directly related to lesion detection. A method leading to image quality assessment which is both human independent, and directly related to lesion detection is very important for the optimal use of mammographic units. This Ph.D thesis presents the steps towards such a method: the computation of realistic virtual images using an 'X ray source/digital detector' model taking into account the physical parameters of the detector (spatial resolution and noise measurements) measured under clinical conditions. From results obtained in this work, we have contributed to establish the link between the physical characteristics of detectors and the clinical quality of the image for usual exposition conditions. Furthermore, we suggest the use of our model for the creation of virtual images, in order to rapidly determine the optimal conditions in mammography, which usually is a long and tedious experimental process. This is an essential aspect to be taken into account for radioprotection of patients, especially in the context of organized mass screening of breast cancer. (author)

  2. Diagnostic performance of MRI measurements to assess hindfoot malalignment. An assessment of four measurement techniques

    International Nuclear Information System (INIS)

    Buck, Florian M.; Hoffmann, Adrienne; Mamisch-Saupe, Nadja; Hodler, Juerg; Farshad, Mazda; Espinosa, Norman; Resnick, Donald

    2013-01-01

    To investigate the ability of coronal non-weight-bearing MR images to discriminate between normal and abnormal hindfoot alignment. Three different measurement techniques (calcaneal axis, medial/lateral calcaneal contour) based on weight-bearing hindfoot alignment radiographs were applied in 49 patients (mean, 48 years; range 21-76 years). Three groups of subjects were enrolled: (1) normal hindfoot alignment (0 -10 valgus); (2) abnormal valgus (>10 ); (3) any degree of varus hindfoot alignment. Hindfoot alignment was then measured on coronal MR images using four different measurement techniques (calcaneal axis, medial/lateral calcaneal contour, sustentaculum tangent). ROC analysis was performed to find the MR measurement with the greatest sensitivity and specificity for discrimination between normal and abnormal hindfoot alignment. The most accurate measurement on MR images to detect abnormal hindfoot valgus was the one using the medial calcaneal contour, reaching a sensitivity/specificity of 86 %/75 % using a cutoff value of >11 valgus. The most accurate measurement on MR images to detect abnormal hindfoot varus was the sustentaculum tangent, reaching a sensitivity/specificity of 91 %/71 % using a cutoff value of <12 valgus. It is possible to suspect abnormal hindfoot alignment on coronal non-weight-bearing MR images. (orig.)

  3. Diagnostic performance of MRI measurements to assess hindfoot malalignment. An assessment of four measurement techniques

    Energy Technology Data Exchange (ETDEWEB)

    Buck, Florian M.; Hoffmann, Adrienne; Mamisch-Saupe, Nadja; Hodler, Juerg [University Hospital Balgrist and University of Zurich, Radiology, Zuerich (Switzerland); Farshad, Mazda; Espinosa, Norman [University Hospital Balgrist and University of Zurich, Department of Orthopaedic Surgery, Zuerich (Switzerland); Resnick, Donald [University of California San Diego, Department of Radiology, San Diego, CA (United States)

    2013-09-15

    To investigate the ability of coronal non-weight-bearing MR images to discriminate between normal and abnormal hindfoot alignment. Three different measurement techniques (calcaneal axis, medial/lateral calcaneal contour) based on weight-bearing hindfoot alignment radiographs were applied in 49 patients (mean, 48 years; range 21-76 years). Three groups of subjects were enrolled: (1) normal hindfoot alignment (0 -10 valgus); (2) abnormal valgus (>10 ); (3) any degree of varus hindfoot alignment. Hindfoot alignment was then measured on coronal MR images using four different measurement techniques (calcaneal axis, medial/lateral calcaneal contour, sustentaculum tangent). ROC analysis was performed to find the MR measurement with the greatest sensitivity and specificity for discrimination between normal and abnormal hindfoot alignment. The most accurate measurement on MR images to detect abnormal hindfoot valgus was the one using the medial calcaneal contour, reaching a sensitivity/specificity of 86 %/75 % using a cutoff value of >11 valgus. The most accurate measurement on MR images to detect abnormal hindfoot varus was the sustentaculum tangent, reaching a sensitivity/specificity of 91 %/71 % using a cutoff value of <12 valgus. It is possible to suspect abnormal hindfoot alignment on coronal non-weight-bearing MR images. (orig.)

  4. Intra-observer reproducibility and diagnostic performance of breast shear-wave elastography in Asian women.

    Science.gov (United States)

    Park, Hye Young; Han, Kyung Hwa; Yoon, Jung Hyun; Moon, Hee Jung; Kim, Min Jung; Kim, Eun-Kyung

    2014-06-01

    Our aim was to evaluate intra-observer reproducibility of shear-wave elastography (SWE) in Asian women. Sixty-four breast masses (24 malignant, 40 benign) were examined with SWE in 53 consecutive Asian women (mean age, 44.9 y old). Two SWE images were obtained for each of the lesions. The intra-observer reproducibility was assessed by intra-class correlation coefficients (ICC). We also evaluated various clinicoradiologic factors that can influence reproducibility in SWE. The ICC of intra-observer reproducibility was 0.789. In clinicoradiologic factor evaluation, masses surrounded by mixed fatty and glandular tissue (ICC: 0.619) showed lower intra-observer reproducibility compared with lesions that were surrounded by glandular tissue alone (ICC: 0.937; p breast SWE was excellent in Asian women. However, it may decrease when breast tissue is in a heterogeneous background. Therefore, SWE should be performed carefully in these cases. Copyright © 2014 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  5. Performance Evaluation of Five Different Disseminated Intravascular Coagulation (DIC) Diagnostic Criteria for Predicting Mortality in Patients with Complicated Sepsis.

    Science.gov (United States)

    Ha, Sang Ook; Park, Sang Hyuk; Hong, Sang Bum; Jang, Seongsoo

    2016-11-01

    Disseminated intravascular coagulation (DIC) is a major complication in sepsis patients. We compared the performance of five DIC diagnostic criteria, focusing on the prediction of mortality. One hundred patients with severe sepsis or septic shock admitted to intensive care unit (ICU) were enrolled. Routine DIC laboratory tests were performed over the first 4 days after admission. The overall ICU and 28-day mortality in DIC patients diagnosed from five criteria (International Society on Thrombosis and Haemostasis [ISTH], the Japanese Association for Acute Medicine [JAAM], the revised JAAM [R-JAAM], the Japanese Ministry of Health and Welfare [JMHW] and the Korean Society on Thrombosis and Hemostasis [KSTH]) were compared. Both KSTH and JMHW criteria showed superior performance than ISTH, JAAM and R-JAAM criteria in the prediction of overall ICU mortality in DIC patients (odds ratio 3.828 and 5.181, P = 0.018 and 0.006, 95% confidence interval 1.256-11.667 and 1.622-16.554, respectively) when applied at day 1 after admission, and survival analysis demonstrated significant prognostic impact of KSTH and JMHW criteria on the prediction of 28-day mortality (P = 0.007 and 0.049, respectively) when applied at day 1 after admission. In conclusion, both KSTH and JMHW criteria would be more useful than other three criteria in predicting prognosis in DIC patients with severe sepsis or septic shock.

  6. Onboard Plasmatron Hydrogen Production for Improved Vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Daniel R. Cohn; Leslie Bromberg; Kamal Hadidi

    2005-12-31

    A plasmatron fuel reformer has been developed for onboard hydrogen generation for vehicular applications. These applications include hydrogen addition to spark-ignition internal combustion engines, NOx trap and diesel particulate filter (DPF) regeneration, and emissions reduction from spark ignition internal combustion engines First, a thermal plasmatron fuel reformer was developed. This plasmatron used an electric arc with relatively high power to reform fuels such as gasoline, diesel and biofuels at an oxygen to carbon ratio close to 1. The draw back of this device was that it has a high electric consumption and limited electrode lifetime due to the high temperature electric arc. A second generation plasmatron fuel reformer was developed. It used a low-current high-voltage electric discharge with a completely new electrode continuation. This design uses two cylindrical electrodes with a rotating discharge that produced low temperature volumetric cold plasma., The lifetime of the electrodes was no longer an issue and the device was tested on several fuels such as gasoline, diesel, and biofuels at different flow rates and different oxygen to carbon ratios. Hydrogen concentration and yields were measured for both the thermal and non-thermal plasmatron reformers for homogeneous (non-catalytic) and catalytic reforming of several fuels. The technology was licensed to an industrial auto part supplier (ArvinMeritor) and is being implemented for some of the applications listed above. The Plasmatron reformer has been successfully tested on a bus for NOx trap regeneration. The successful development of the plasmatron reformer and its implementation in commercial applications including transportation will bring several benefits to the nation. These benefits include the reduction of NOx emissions, improving engine efficiency and reducing the nation's oil consumption. The objective of this program has been to develop attractive applications of plasmatron fuel reformer

  7. Physical examination tests of the shoulder: a systematic review and meta-analysis of diagnostic test performance.

    Science.gov (United States)

    Gismervik, Sigmund Ø; Drogset, Jon O; Granviken, Fredrik; Rø, Magne; Leivseth, Gunnar

    2017-01-25

    Physical examination tests of the shoulder (PETS) are clinical examination maneuvers designed to aid the assessment of shoulder complaints. Despite more than 180 PETS described in the literature, evidence of their validity and usefulness in diagnosing the shoulder is questioned. This meta-analysis aims to use diagnostic odds ratio (DOR) to evaluate how much PETS shift overall probability and to rank the test performance of single PETS in order to aid the clinician's choice of which tests to use. This study adheres to the principles outlined in the Cochrane guidelines and the PRISMA statement. A fixed effect model was used to assess the overall diagnostic validity of PETS by pooling DOR for different PETS with similar biomechanical rationale when possible. Single PETS were assessed and ranked by DOR. Clinical performance was assessed by sensitivity, specificity, accuracy and likelihood ratio. Six thousand nine-hundred abstracts and 202 full-text articles were assessed for eligibility; 20 articles were eligible and data from 11 articles could be included in the meta-analysis. All PETS for SLAP (superior labral anterior posterior) lesions pooled gave a DOR of 1.38 [1.13, 1.69]. The Supraspinatus test for any full thickness rotator cuff tear obtained the highest DOR of 9.24 (sensitivity was 0.74, specificity 0.77). Compression-Rotation test obtained the highest DOR (6.36) among single PETS for SLAP lesions (sensitivity 0.43, specificity 0.89) and Hawkins test obtained the highest DOR (2.86) for impingement syndrome (sensitivity 0.58, specificity 0.67). No single PETS showed superior clinical test performance. The clinical performance of single PETS is limited. However, when the different PETS for SLAP lesions were pooled, we found a statistical significant change in post-test probability indicating an overall statistical validity. We suggest that clinicians choose their PETS among those with the highest pooled DOR and to assess validity to their own specific clinical

  8. Incremental Diagnostic Performance of Combined Parameters in the Detection of Severe Coronary Artery Disease Using Exercise Gated Myocardial Perfusion Imaging.

    Directory of Open Access Journals (Sweden)

    Chia-Ju Liu

    Full Text Available Myocardial perfusion imaging (MPI using gated single-photon emission tomography (gSPECT may underestimate the severity of coronary artery disease (CAD. This study aimed to evaluate the significance of combined parameters derived from gSPECT, as well as treadmill stress test parameters, in the detection of severe CAD.A total of 211 consecutive patients referred for exercise MPI between June 2011 and June 2013 (who received invasive coronary angiography within six months after MPI were retrospectively reviewed. Exercise MPI was performed with Bruce protocol and 201Tl injected at peak exercise. Gated SPECT was performed using a cadmium-zinc-telluride camera and processed by QPS/QGS software. Perfusion defect abnormalities such as sum stress score (SSS; sum difference score, algorithm-derived total perfusion deficits, transient ischemic dilatation ratios of end-diastolic volumes and end-systolic volumes, post-stress changes in ejection fraction, and lung/heart ratio (LHR were calculated. Treadmill parameters, including ST depression (STD at the 1st and 3rd minutes of recovery stage (1'STD and 3'STD, maximal STD corrected by heart rate increment (ST/HR, heart rate decline in 1st and 3rd minutes of recovery stage, recovery heart rate ratio (HR ratio, systolic and mean blood pressure ratios (SBP ratio and MAP ratio during recovery phase were recorded. Diagnostic performances of these parameters were analyzed with receiver operating characteristic (ROC analysis and logistic regression for detection of left main (≥ 50% or 3-vessel disease (all ≥ 70% luminal stenosis on invasive angiography.Among various MPI and treadmill parameters used for detection of severe CAD, SSS and ST/HR had the highest AUC (0.78, 0.73, p = NS and best cut-off values (SSS > 6, ST/HR > 17.39 10-2mV/bpm, respectively. By univariate logistic regression, all parameters except 1'HRR, 3'HRR, SBP and MAP ratios increased the odds ratio of severe CAD. Only increased L/H ratio, 3'STD

  9. Diagnostic performance of CT and MRI on the detection of symptomatic intracranial dural arteriovenous fistula: a meta-analysis with indirect comparison

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Yen-Heng [National Taiwan University, Institute of Epidemiology and Preventive Medicine, Taipei (China); National Taiwan University Hospital in Taipei and Yuan-Lin Branch, Department of Medical Imaging and Radiology, Hospital and Medical College, Taipei (China); Lin, Hsien-Ho [National Taiwan University, Institute of Epidemiology and Preventive Medicine, Taipei (China); Liu, Hon-Man; Lee, Chung-Wei; Chen, Ya-Fang [National Taiwan University Hospital in Taipei and Yuan-Lin Branch, Department of Medical Imaging and Radiology, Hospital and Medical College, Taipei (China)

    2016-08-15

    This study aims to review the diagnostic performance of computed tomography (CT) and magnetic resonance imaging (MRI) in symptomatic dural arteriovenous fistula (DAVF). EMBASE, PubMed, and Cochrane Library were searched until April 2015 for studies which compared CT, MRI, or both with angiography for the detection of DAVF. The diagnostic performances of MRI and CT were indirectly compared using modality as a covariate in the analysis. Thirteen studies met our inclusion criteria. MRI had a sensitivity of 0.90 (95 % confidence interval (CI) = 0.83-0.94) and specificity of 0.94 (95 % CI = 0.90-0.96). CT had a sensitivity of 0.80 (95 % CI = 0.62-0.90) and specificity of 0.87 (95 % CI = 0.74-0.94). MRI showed better diagnostic performance than CT (p = 0.02). Contrast medium use and time-resolved MR angiography did not improve MRI diagnostic performance (p = 0.31 and 0.44, respectively). Both CT and MRI had good diagnostic performance. MRI was better than CT on the detection of symptomatic intracranial dural arteriovenous fistula in the indirect comparison. (orig.)

  10. Adaptive statistical iterative reconstruction and Veo: assessment of image quality and diagnostic performance in CT colonography at various radiation doses.

    Science.gov (United States)

    Yoon, Min A; Kim, Se Hyung; Lee, Jeong Min; Woo, Hyoun Sik; Lee, Eun Sun; Ahn, Se Jin; Han, Joon Koo

    2012-01-01

    To evaluate the diagnostic performance of computed tomography (CT) colonography (CTC) reconstructed with different levels of adaptive statistical iterative reconstruction (ASiR, GE Healthcare) and Veo (model-based iterative reconstruction, GE Healthcare) at various tube currents in detection of polyps in porcine colon phantoms. Five porcine colon phantoms with 46 simulated polyps were scanned at different radiation doses (10, 30, and 50 mA s) and were reconstructed using filtered back projection (FBP), ASiR (20%, 40%, and 60%) and Veo. Eleven data sets for each phantom (10-mA s FBP, 10-mA s 20% ASiR, 10-mA s 40% ASiR, 10-mA s 60% ASiR, 10-mA s Veo, 30-mA s FBP, 30-mA s 20% ASiR, 30-mA s 40% ASiR, 30-mA s 60% ASiR, 30-mA s Veo, and 50-mA s FBP) yielded a total of 55 data sets. Polyp detection sensitivity and confidence level of 2 independent observers were evaluated with the McNemar test, the Fisher exact test, and receiver operating characteristic curve analysis. Comparative analyses of overall image quality score, measured image noise, and interpretation time were also performed. Per-polyp detection sensitivities and specificities were highest in 10-mA s Veo, 30-mA s FBP, 30-mA s 60% ASiR, and 50-mA s FBP (sensitivity, 100%; specificity, 100%). The area-under-the-curve values for the overall performance of each data set was also highest (1.000) at 50-mA s FBP, 30-mA s FBP, 30-mA s 60% ASiR, and 10-mA s Veo. Images reconstructed with ASiR showed statistically significant improvement in per-polyp detection sensitivity as the percent level of per-polyp sensitivity increased (10-mA s FBP vs 10-mA s 20% ASiR, P = 0.011; 10-mA s FBP vs 10-mA s 40% ASiR, P = 0.000; 10-mA s FBP vs 10-mA s 60% ASiR, P = 0.000; 10-mA s 20% ASiR vs 40% ASiR, P = 0.034). Overall image quality score was highest at 30-mA s Veo and 50-mA s FBP. The quantitative measurement of the image noise was lowest at 30-mA s Veo and second lowest at 10-mA s Veo. There was a trend of decrease in time

  11. Pregnancy differentially impacts performance of latent tuberculosis diagnostics in a high-burden setting.

    Directory of Open Access Journals (Sweden)

    Jyoti S Mathad

    Full Text Available Targeted screening for latent TB infection (LTBI in vulnerable populations is a recommended TB control strategy. Pregnant women are at high risk for developing TB and likely to access healthcare, making pregnancy an important screening opportunity in developing countries. The sensitivity of the widely-used tuberculin skin test (TST, however, may be reduced during pregnancy.We performed a cross-sectional study comparing the TST with the QuantiFERON Gold In-tube (QGIT in 401 HIV-negative women presenting antepartum (n = 154, at delivery (n = 148, or postpartum (n = 99 to a government hospital in Pune, India. A subset of 60 women enrolled during pregnancy was followed longitudinally and received both tests at all three stages of pregnancy.The QGIT returned significantly more positive results than the TST. Of the 401 women in the cross-sectional study, 150 (37% had a positive QGIT, compared to 59 (14% for the TST (p<0.005. Forty-nine (12% did not have their TST read. Of 356 who had both results available, 46 (13% were concordant positive, 91 (25% were discordant (12 (3% TST+/QGIT-; 79 (22% TST-/QGIT+, and 206 (57% concordant negative. Comparison by stage of pregnancy revealed that QGIT percent positivity remained stable between antepartum and delivery, unlike TST results (QGIT 31-32% vs TST 11-17%. Median IFN-γ concentration was lower at delivery than in antepartum or postpartum (1.66 vs 2.65 vs 8.99 IU/mL, p = 0.001. During postpartum, both tests had significantly increased positives (QGIT 31% vs 32% vs 52%, p = 0.01; TST 17% vs 11% vs 25%, p<0.005. The same trends were observed in the longitudinal subset.Timing and choice of LTBI test during pregnancy impact results. QGIT was more stable and more closely approximated the LTBI prevalence in India. But pregnancy stage clearly affects both tests, raising important questions about how the complex immune changes brought on by pregnancy may impact LTBI screening.

  12. Pregnancy differentially impacts performance of latent tuberculosis diagnostics in a high-burden setting.

    Science.gov (United States)

    Mathad, Jyoti S; Bhosale, Ramesh; Sangar, Vikrant; Mave, Vidya; Gupte, Nikhil; Kanade, Savita; Nangude, Ashwini; Chopade, Kavita; Suryavanshi, Nishi; Deshpande, Prasad; Kulkarni, Vandana; Glesby, Marshall J; Fitzgerald, Daniel; Bharadwaj, Renu; Sambarey, Pradeep; Gupta, Amita

    2014-01-01

    Targeted screening for latent TB infection (LTBI) in vulnerable populations is a recommended TB control strategy. Pregnant women are at high risk for developing TB and likely to access healthcare, making pregnancy an important screening opportunity in developing countries. The sensitivity of the widely-used tuberculin skin test (TST), however, may be reduced during pregnancy. We performed a cross-sectional study comparing the TST with the QuantiFERON Gold In-tube (QGIT) in 401 HIV-negative women presenting antepartum (n = 154), at delivery (n = 148), or postpartum (n = 99) to a government hospital in Pune, India. A subset of 60 women enrolled during pregnancy was followed longitudinally and received both tests at all three stages of pregnancy. The QGIT returned significantly more positive results than the TST. Of the 401 women in the cross-sectional study, 150 (37%) had a positive QGIT, compared to 59 (14%) for the TST (p<0.005). Forty-nine (12%) did not have their TST read. Of 356 who had both results available, 46 (13%) were concordant positive, 91 (25%) were discordant (12 (3%) TST+/QGIT-; 79 (22%) TST-/QGIT+), and 206 (57%) concordant negative. Comparison by stage of pregnancy revealed that QGIT percent positivity remained stable between antepartum and delivery, unlike TST results (QGIT 31-32% vs TST 11-17%). Median IFN-γ concentration was lower at delivery than in antepartum or postpartum (1.66 vs 2.65 vs 8.99 IU/mL, p = 0.001). During postpartum, both tests had significantly increased positives (QGIT 31% vs 32% vs 52%, p = 0.01; TST 17% vs 11% vs 25%, p<0.005). The same trends were observed in the longitudinal subset. Timing and choice of LTBI test during pregnancy impact results. QGIT was more stable and more closely approximated the LTBI prevalence in India. But pregnancy stage clearly affects both tests, raising important questions about how the complex immune changes brought on by pregnancy may impact LTBI screening.

  13. Diagnostic Performance of Tuberculosis-Specific IgG Antibody Profiles in Patients with Presumptive Tuberculosis from Two Continents.

    Science.gov (United States)

    Broger, Tobias; Basu Roy, Robindra; Filomena, Angela; Greef, Charles H; Rimmele, Stefanie; Havumaki, Joshua; Danks, David; Schneiderhan-Marra, Nicole; Gray, Christen M; Singh, Mahavir; Rosenkrands, Ida; Andersen, Peter; Husar, Gregory M; Joos, Thomas O; Gennaro, Maria L; Lochhead, Michael J; Denkinger, Claudia M; Perkins, Mark D

    2017-04-01

    Development of rapid diagnostic tests for tuberculosis is a global priority. A whole proteome screen identified Mycobacterium tuberculosis antigens associated with serological responses in tuberculosis patients. We used World Health Organization (WHO) target product profile (TPP) criteria for a detection test and triage test to evaluate these antigens. Consecutive patients presenting to microscopy centers and district hospitals in Peru and to outpatient clinics at a tuberculosis reference center in Vietnam were recruited. We tested blood samples from 755 HIV-uninfected adults with presumptive pulmonary tuberculosis to measure IgG antibody responses to 57 M. tuberculosis antigens using a field-based multiplexed serological assay and a 132-antigen bead-based reference assay. We evaluated single antigen performance and models of all possible 3-antigen combinations and multiantigen combinations. Three-antigen and multiantigen models performed similarly and were superior to single antigens. With specificity set at 90% for a detection test, the best sensitivity of a 3-antigen model was 35% (95% confidence interval [CI], 31-40). With sensitivity set at 85% for a triage test, the specificity of the best 3-antigen model was 34% (95% CI, 29-40). The reference assay also did not meet study targets. Antigen performance differed significantly between the study sites for 7/22 of the best-performing antigens. Although M. tuberculosis antigens were recognized by the IgG response during tuberculosis, no single antigen or multiantigen set performance approached WHO TPP criteria for clinical utility among HIV-uninfected adults with presumed tuberculosis in high-volume, urban settings in tuberculosis-endemic countries. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America.

  14. Plasma Diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Zaveryaev, V [Kurchatov Institute, Moscow (Russian Federation); others, and

    2012-09-15

    The success in achieving peaceful fusion power depends on the ability to control a high temperature plasma, which is an object with unique properties, possibly the most complicated object created by humans. Over years of fusion research a new branch of science has been created, namely plasma diagnostics, which involves knowledge of almost all fields of physics, from electromagnetism to nuclear physics, and up-to-date progress in engineering and technology (materials, electronics, mathematical methods of data treatment). Historically, work on controlled fusion started with pulsed systems and accordingly the methods of plasma parameter measurement were first developed for short lived and dense plasmas. Magnetically confined hot plasmas require the creation of special experimental techniques for diagnostics. The diagnostic set is the most scientifically intensive part of a plasma device. During many years of research operation some scientific tasks have been solved while new ones arose. New tasks often require significant changes in the diagnostic system, which is thus a very flexible part of plasma machines. Diagnostic systems are designed to solve several tasks. As an example here are the diagnostic tasks for the International Thermonuclear Experimental Reactor - ITER: (1) Measurements for machine protection and basic control; (2) Measurements for advanced control; (3) Additional measurements for performance evaluation and physics. Every new plasma machine is a further step along the path to the main goal - controlled fusion - and nobody knows in advance what new phenomena will be met on the way. So in the planning of diagnostic construction we should keep in mind further system upgrading to meet possible new scientific and technical challenges. (author)

  15. Computational Approach for Securing Radiology-Diagnostic Data in Connected Health Network using High-Performance GPU-Accelerated AES.

    Science.gov (United States)

    Adeshina, A M; Hashim, R

    2017-03-01

    Diagnostic radiology is a core and integral part of modern medicine, paving ways for the primary care physicians in the disease diagnoses, treatments and therapy managements. Obviously, all recent standard healthcare procedures have immensely benefitted from the contemporary information technology revolutions, apparently revolutionizing those approaches to acquiring, storing and sharing of diagnostic data for efficient and timely diagnosis of diseases. Connected health network was introduced as an alternative to the ageing traditional concept in healthcare system, improving hospital-physician connectivity and clinical collaborations. Undoubtedly, the modern medicinal approach has drastically improved healthcare but at the expense of high computational cost and possible breach of diagnosis privacy. Consequently, a number of cryptographical techniques are recently being applied to clinical applications, but the challenges of not being able to successfully encrypt both the image and the textual data persist. Furthermore, processing time of encryption-decryption of medical datasets, within a considerable lower computational cost without jeopardizing the required security strength of the encryption algorithm, still remains as an outstanding issue. This study proposes a secured radiology-diagnostic data framework for connected health network using high-performance GPU-accelerated Advanced Encryption Standard. The study was evaluated with radiology image datasets consisting of brain MR and CT datasets obtained from the department of Surgery, University of North Carolina, USA, and the Swedish National Infrastructure for Computing. Sample patients' notes from the University of North Carolina, School of medicine at Chapel Hill were also used to evaluate the framework for its strength in encrypting-decrypting textual data in the form of medical report. Significantly, the framework is not only able to accurately encrypt and decrypt medical image datasets, but it also

  16. Comparison of onboard low-field magnetic resonance imaging versus onboard computed tomography for anatomy visualization in radiotherapy.

    Science.gov (United States)

    Noel, Camille E; Parikh, Parag J; Spencer, Christopher R; Green, Olga L; Hu, Yanle; Mutic, Sasa; Olsen, Jeffrey R

    2015-01-01

    Onboard magnetic resonance imaging (OB-MRI) for daily localization and adaptive radiotherapy has been under development by several groups. However, no clinical studies have evaluated whether OB-MRI improves visualization of the target and organs at risk (OARs) compared to standard onboard computed tomography (OB-CT). This study compared visualization of patient anatomy on images acquired on the MRI-(60)Co ViewRay system to those acquired with OB-CT. Fourteen patients enrolled on a protocol approved by the Institutional Review Board (IRB) and undergoing image-guided radiotherapy for cancer in the thorax (n = 2), pelvis (n = 6), abdomen (n = 3) or head and neck (n = 3) were imaged with OB-MRI and OB-CT. For each of the 14 patients, the OB-MRI and OB-CT datasets were displayed side-by-side and independently reviewed by three radiation oncologists. Each physician was asked to evaluate which dataset offered better visualization of the target and OARs. A quantitative contouring study was performed on two abdominal patients to assess if OB-MRI could offer improved inter-observer segmentation agreement for adaptive planning. In total 221 OARs and 10 targets were compared for visualization on OB-MRI and OB-CT by each of the three physicians. The majority of physicians (two or more) evaluated visualization on MRI as better for 71% of structures, worse for 10% of structures, and equivalent for 14% of structures. 5% of structures were not visible on either. Physicians agreed unanimously for 74% and in majority for > 99% of structures. Targets were better visualized on MRI in 4/10 cases, and never on OB-CT. Low-field MR provides better anatomic visualization of many radiotherapy targets and most OARs as compared to OB-CT. Further studies with OB-MRI should be pursued.

  17. Comparison of the diagnostic performance of microscopic examination with nested polymerase chain reaction for optimum malaria diagnosis in Upper Myanmar.

    Science.gov (United States)

    Kang, Jung-Mi; Cho, Pyo-Yun; Moe, Mya; Lee, Jinyoung; Jun, Hojong; Lee, Hyeong-Woo; Ahn, Seong Kyu; Kim, Tae Im; Pak, Jhang Ho; Myint, Moe Kyaw; Lin, Khin; Kim, Tong-Soo; Na, Byoung-Kuk

    2017-03-16

    Accurate diagnosis of Plasmodium infection is crucial for prompt malaria treatment and surveillance. Microscopic examination has been widely applied as the gold standard for malaria diagnosis in most part of malaria endemic areas, but its diagnostic value has been questioned, particularly in submicroscopic malaria. In this study, the diagnostic performance of microscopic examination and nested polymerase chain reaction (PCR) was evaluated to establish optimal malaria diagnosis method in Myanmar. A total of 1125 blood samples collected from residents in the villages and towns located in Naung Cho, Pyin Oo Lwin, Tha Beik Kyin townships and Mandalay of Upper Myanmar were screened by microscopic examination and species-specific nested PCR method. Among the 1125 blood samples, 261 samples were confirmed to be infected with malaria by microscopic examination. Evaluation of the 1125 samples by species-specific nested PCR analysis revealed that the agreement between microscopic examination and nested PCR was 87.3% (261/299). Nested PCR successfully detected 38 Plasmodium falciparum or Plasmodium vivax infections, which were missed in microscopic examination. Microscopic examinations also either misdiagnosed the infected Plasmodium species, or did not detect mixed infections with different Plasmodium species in 31 cases. The nested PCR method is more reliable than conventional microscopic examination for the diagnosis of malaria infections, and this is particularly true in cases of mixed infections and submicroscopic infections. Given the observed higher sensitivity and specificity of nested PCR, the molecular method holds enormous promise in malaria diagnosis and species differentiation, and can be applied as an effective monitoring tool for malaria surveillance, control and elimination in Myanmar.

  18. Diagnostic performance of dental students in identifying mandibular condyle fractures by panoramic radiography and the usefulness of reference images

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Bong Hae [School of Dentistry, Pusan National University, Pusan (Korea, Republic of)

    2011-06-15

    The purpose of this study was to evaluate the diagnostic performance of dental students in detection of mandibular condyle fractures and the effectiveness of reference panoramic images. Forty-six undergraduates evaluated 25 panoramic radiographs for condylar fractures and the data were analyzed through receiver operating characteristic (ROC) analysis. After a month, they were divided into two homogeneous groups based on the first results and re-evaluated the images with (group A) or without (group B) reference images. Eight reference images included indications showing either typical condylar fractures or anatomic structures which could be confused with fractures. Paired t-test was used for statistical analysis of the difference between the first and the second evaluations for each group, and student's t-test was used between the two groups in the second evaluation. The intra- and inter-observer agreements were evaluated with Kappa statistics. Intra- and inter-observer agreements were substantial (k=0.66) and moderate (k=0.53), respectively. The area under the ROC curve (Az) in the first evaluation was 0.802. In the second evaluation, it was increased to 0.823 for group A and 0.814 for group B. The difference between the first and second evaluations for group A was statistically significant (p<0.05), however there was no statistically significant difference between the two groups in the second evaluation. Providing reference images to less experienced clinicians would be a good way to improve the diagnostic ability in detecting condylar fracture.

  19. On-Board, Real-Time Preprocessing System for Optical Remote-Sensing Imagery.

    Science.gov (United States)

    Qi, Baogui; Shi, Hao; Zhuang, Yin; Chen, He; Chen, Liang

    2018-04-25

    With the development of remote-sensing technology, optical remote-sensing imagery processing has played an important role in many application fields, such as geological exploration and natural disaster prevention. However, relative radiation correction and geometric correction are key steps in preprocessing because raw image data without preprocessing will cause poor performance during application. Traditionally, remote-sensing data are downlinked to the ground station, preprocessed, and distributed to users. This process generates long delays, which is a major bottleneck in real-time applications for remote-sensing data. Therefore, on-board, real-time image preprocessing is greatly desired. In this paper, a real-time processing architecture for on-board imagery preprocessing is proposed. First, a hierarchical optimization and mapping method is proposed to realize the preprocessing algorithm in a hardware structure, which can effectively reduce the computation burden of on-board processing. Second, a co-processing system using a field-programmable gate array (FPGA) and a digital signal processor (DSP; altogether, FPGA-DSP) based on optimization is designed to realize real-time preprocessing. The experimental results demonstrate the potential application of our system to an on-board processor, for which resources and power consumption are limited.

  20. On-Board, Real-Time Preprocessing System for Optical Remote-Sensing Imagery

    Science.gov (United States)

    Qi, Baogui; Zhuang, Yin; Chen, He; Chen, Liang

    2018-01-01

    With the development of remote-sensing technology, optical remote-sensing imagery processing has played an important role in many application fields, such as geological exploration and natural disaster prevention. However, relative radiation correction and geometric correction are key steps in preprocessing because raw image data without preprocessing will cause poor performance during application. Traditionally, remote-sensing data are downlinked to the ground station, preprocessed, and distributed to users. This process generates long delays, which is a major bottleneck in real-time applications for remote-sensing data. Therefore, on-board, real-time image preprocessing is greatly desired. In this paper, a real-time processing architecture for on-board imagery preprocessing is proposed. First, a hierarchical optimization and mapping method is proposed to realize the preprocessing algorithm in a hardware structure, which can effectively reduce the computation burden of on-board processing. Second, a co-processing system using a field-programmable gate array (FPGA) and a digital signal processor (DSP; altogether, FPGA-DSP) based on optimization is designed to realize real-time preprocessing. The experimental results demonstrate the potential application of our system to an on-board processor, for which resources and power consumption are limited. PMID:29693585

  1. IBIS: the imager on-board integral

    International Nuclear Information System (INIS)

    Ubertini, P.; Bazzano, A.; Lebrun, F.; Goldwurm, A.; Laurent, P.; Mirabel, I.F.; Vigroux, L.; Di Cocco, G.; Labanti, C.; Bird, A.J.; Broenstad, K.; La Rosa, G.; Sacco, B.; Quadrini, E.M.; Ramsey, B.; Weisskopf, M.C.; Reglero, V.; Sabau, L.; Staubert, R.; Zdziarski, A.A.

    2003-01-01

    The IBIS telescope is the high angular resolution gamma-ray imager on-board the INTEGRAL Observatory, successfully launched from Baikonur (Kazakhstan) on October 2002. This medium size ESA project, planned for a 2 year mission with possible extension to 5, is devoted to the observation of the gamma-ray sky in the energy range from 3 keV to 10 MeV (Winkler 2001). The IBIS imaging system is based on two independent solid state detector arrays optimised for low (15-1000 keV) and high (0.175-10.0 MeV) energies surrounded by an active VETO System. This high efficiency shield is essential to minimise the background induced by high energy particles in the highly ex-centric out of van Allen belt orbit. A Tungsten Coded Aperture Mask, 16 mm thick and ∼ 1 squared meter in dimension is the imaging device. The IBIS telescope will serve the scientific community at large providing a unique combination of unprecedented high energy wide field imaging capability coupled with broad band spectroscopy and high resolution timing over the energy range from X to gamma rays. To date the IBIS telescope is working nominally in orbit since more than 9 month. (authors)

  2. The Importance of Urine Concentration on the Diagnostic Performance of the Urinalysis for Pediatric Urinary Tract Infection.

    Science.gov (United States)

    Chaudhari, Pradip P; Monuteaux, Michael C; Shah, Pinkey; Bachur, Richard G

    2017-07-01

    The presence of leukocyte esterase by urine dipstick and microscopic pyuria are both indicators of possible urinary tract infection. The effect of urine concentration on the diagnostic performance of the urinalysis for pediatric urinary tract infection has not been studied. Our objective is to determine whether the urinalysis performance for detecting urinary tract infection varies by urine concentration as measured by specific gravity. This was a retrospective cross-sectional study of the urine laboratory results of children younger than 13 years who presented to the emergency department during 68 months and had a paired urinalysis and urine culture obtained. Urinary tract infection was defined as pure growth of a uropathogen at standard culture thresholds. Test characteristics were calculated across 4 specific gravity groups (1.000 to 1.010, 1.011 to 1.020, 1.021 to 1.030, and >1.030). In total, 14,971 cases were studied. Median age was 1.5 years (interquartile range 0.4 to 5.5 years) and 60% were female patients. Prevalence of urinary tract infection was 7.7%. For the presence of leukocyte esterase and a range of pyuria cut points, the positive likelihood ratios decreased with increasing specific gravity. From most dilute to most concentrated urine, the positive likelihood ratio decreased from 12.1 (95% confidence interval [CI] 10.7 to 13.7) to 4.2 (95% CI 3.0 to 5.8) and 9.5 (95% CI 8.6 to 10.6) to 5.5 (95% CI 3.3 to 9.1) at a threshold of greater than or equal to 5 WBCs per high-power field and presence of leukocyte esterase, respectively. The negative likelihood ratios increased with increasing specific gravity for leukocyte esterase and microscopic pyuria. For the detection of pediatric urinary tract infection, the diagnostic performance of both dipstick leukocyte esterase and microscopic pyuria varies by urine concentration, and therefore the specific gravity should be considered when the urinalysis is interpreted. Copyright © 2016 American College of

  3. Contrast-enhanced ultrasound features of histologically proven focal nodular hyperplasia: diagnostic performance compared with contrast-enhanced CT

    International Nuclear Information System (INIS)

    Wang, Wei; Chen, Li-Da; Liu, Guang-Jian; Xu, Zuo-Feng; Xie, Xiao-Yan; Wang, Yan; Zhou, Lu-Yao; Lu, Ming-De; Shen, Shun-Li

    2013-01-01

    To investigate and compare contrast-enhanced ultrasound (CEUS) in the characterisation of histologically proven focal nodular hyperplasia (FNH) with contrast-enhanced computed tomography (CECT). CEUS was performed in 85 patients with 85 histologically proven FNHs. Enhancement, centrifugal filling, spoke-wheel arteries, feeding artery and central scarring were reviewed and correlated with lesion size or liver background. Independent factors for predicting FNH from other focal liver lesions (FLLs) were evaluated. Forty-seven FLLs with CECT were randomly selected for comparison of diagnostic performance with CEUS. Centrifugal filling was more common (P = 0.002) and the significant predictor (P = 0.003) in FNHs ≤3 cm. Lesion size or liver background has no significant influence on the detection rate of the spoke-wheel arteries and feeding artery (P > 0.05). Central scarring was found in 42.6 % of FNHs ≥3 cm (P = 0.000). The area under the ROC curve, sensitivity and specificity showed no significant differences between CEUS and CECT (P > 0.05), except that the sensitivity of CEUS was better for reader 1 (P = 0.041). CEUS is valuable in characterising centrifugal filling signs or spoke wheels in small FNHs and should be employed as the first-line imaging technique for diagnosis of FNH. (orig.)

  4. Comparison of Diagnostic Performance of Three-Dimensional Positron Emission Mammography versus Whole Body Positron Emission Tomography in Breast Cancer

    Directory of Open Access Journals (Sweden)

    Dong Dai

    2017-01-01

    Full Text Available Objective. To compare the diagnostic performance of three-dimensional (3D positron emission mammography (PEM versus whole body positron emission tomography (WBPET for breast cancer. Methods. A total of 410 women with normal breast or benign or highly suspicious malignant tumors were randomized at 1 : 1 ratio to undergo 3D-PEM followed by WBPET or WBPET followed by 3D-PEM. Lumpectomy or mastectomy was performed on eligible participants after the scanning. Results. The sensitivity and specificity of 3D-PEM were 92.8% and 54.5%, respectively. WBPET showed a sensitivity of 95.7% and specificity of 56.8%. After exclusion of the patients with lesions beyond the detecting range of the 3D-PEM instrument, 3D-PEM showed higher sensitivity than WBPET (97.0% versus 95.5%, P = 0.913, particularly for small lesions (<1 cm (72.0% versus 60.0%, P = 0.685. Conclusions. The 3D-PEM appears more sensitive to small lesions than WBPET but may fail to detect lesions that are beyond the detecting range. This study was approved by the Ethics Committee (E2012052 at the Tianjin Medical University Cancer Institute and Hospital (Tianjin, China. The instrument positron emission mammography (PEMi was approved by China State Food and Drug Administration under the registration number 20153331166.

  5. Magnetic resonance imaging and magnetic resonance arthrography of the shoulder: dependence on the level of training of the performing radiologist for diagnostic accuracy

    Energy Technology Data Exchange (ETDEWEB)

    Theodoropoulos, John S. [University of Toronto, Division of Orthopaedics, Mount Sinai Hospital and the University Health Network, Toronto, ON (Canada); Andreisek, Gustav [University of Toronto, Department of Medical Imaging, Mount Sinai Hospital and the University Health Network, Toronto, ON (Canada); University Hospital Zuerich, Institute for Diagnostic Radiology, Zuerich (Switzerland); Harvey, Edward J. [McGill University, Division of Orthopaedics, MUHC - Montreal General Hospital, Montreal, Quebec (Canada); Wolin, Preston [Center for Athletic Medicine, Chicago, IL (United States)

    2010-07-15

    Discrepancies were identified between magnetic resonance (MR) imaging and clinical findings in patients who had MR imaging examinations evaluated by community-based general radiologists. The purpose of this study was to evaluate the diagnostic performance of MR imaging examinations of the shoulder with regard to the training level of the performing radiologist. A review of patient charts identified 238 patients (male/female, 175/63; mean age, 40.4 years) in whom 250 arthroscopies were performed and who underwent MR imaging or direct MR arthrography in either a community-based or hospital-based institution prior to surgery. All MR imaging and surgical reports were reviewed and the diagnostic performance for the detection of labral, rotator cuff, biceps, and Hill-Sachs lesions was determined. Kappa and Student's t test analyses were performed in a subset of cases in which initial community-based MR images were re-evaluated by hospital-based musculoskeletal radiologists, to determine the interobserver agreement and any differences in image interpretation. The diagnostic performance of community-based general radiologists was lower than that of hospital-based sub-specialized musculoskeletal radiologists. A sub-analysis of re-evaluated cases showed that musculoskeletal radiologists performed better. {kappa} values were 0.208, 0.396, 0.376, and 0.788 for labral, rotator cuff, biceps, and Hill-Sachs lesions (t test statistics: p =<0.001, 0.004, 0.019, and 0.235). Our results indicate that the diagnostic performance of MR imaging and MR arthrography of the shoulder depends on the training level of the performing radiologist, with sub-specialized musculoskeletal radiologists having a better diagnostic performance than general radiologists. (orig.)

  6. Comparison of diagnostic performance between single- and multiphasic contrast-enhanced abdominopelvic computed tomography in patients admitted to the emergency department with abdominal pain: potential radiation dose reduction.

    Science.gov (United States)

    Hwang, Shin Hye; You, Je Sung; Song, Mi Kyong; Choi, Jin-Young; Kim, Myeong-Jin; Chung, Yong Eun

    2015-04-01

    To evaluate feasibility of radiation dose reduction by optimal phase selection of computed tomography (CT) in patients who visited the emergency department (ED) for abdominal pain. We included 253 patients who visited the ED for abdominal pain. They underwent multiphasic CT including precontrast, late arterial phase (LAP), and hepatic venous phase (HVP). Three image sets (HVP, precontrast + HVP, and precontrast + LAP + HVP) were reviewed. Two reviewers determined the most appropriate diagnosis with five-point confidence scale. Diagnostic performances were compared among image sets by weighted-least-squares method or DeLong's method. Linear mixed model was used to assess changes of diagnostic confidence and radiation dose. There was no difference in diagnostic performance among three image sets, although diagnostic confidence level was significantly improved after review of triphasic images compared with both HVP images only or HVP with precontrast images (confidence scale, 4.64 ± 0.05, 4.66 ± 0.05, and 4.76 ± 0.04 in the order of the sets; overall P = 0.0008). Similar trends were observed in the subgroup analysis for diagnosis of pelvic inflammatory disease and cholecystitis. There is no difference between HVP-CT alone and multiphasic CT for the diagnosis of causes of abdominal pain in patients admitted to the ED without prior chronic disease or neoplasia. • There was no difference in diagnostic performance of HVP CT and multiphasic CT. • The diagnostic confidence level was improved after review of the LAP images. • HVP CT can achieve diagnostic performance similar to that of multiphasic CT, while minimizing radiation.

  7. Diagnostic performance of major depression disorder case-finding instruments used among mothers of young children in the United States: A systematic review.

    Science.gov (United States)

    Owora, Arthur H; Carabin, Hélène; Reese, Jessica; Garwe, Tabitha

    2016-09-01

    Growing recognition of the interrelated negative outcomes associated with major depression disorder (MDD) among mothers and their children has led to renewed public health interest in the early identification and treatment of maternal MDD. Healthcare providers, however, remain unsure of the validity of existing case-finding instruments. We conducted a systematic review to identify the most valid maternal MDD case-finding instrument used in the United States. We identified articles reporting the sensitivity and specificity of MDD case-finding instruments based on Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) by systematically searching through three electronic bibliographic databases, PubMed, PsycINFO, and EMBASE, from 1994 to 2014. Study eligibility and quality were evaluated using the Standards for the Reporting of Diagnostic Accuracy studies and Quality Assessment of Diagnostic Accuracy Studies guidelines respectively. Overall, we retrieved 996 unduplicated articles and selected 74 for full-text review. Of these, 14 articles examining 21 different instruments were included in the systematic review. The 10 item Edinburgh Postnatal Depression Scale and Postpartum Depression Screening Scale had the most stable (lowest variation) and highest diagnostic performance during the antepartum and postpartum periods (sensitivity range: 0.63-0.94 and 0.67-0.95; specificity range: 0.83-0.98 and 0.68-0.97 respectively). Greater variation in diagnostic performance was observed among studies with higher MDD prevalence. Factors that explain greater variation in instrument diagnostic performance in study populations with higher MDD prevalence were not examined. Findings suggest that the diagnostic performance of maternal MDD case-finding instruments is peripartum period-specific. Published by Elsevier B.V.

  8. Medicalising normality? Using a simulated dataset to assess the performance of different diagnostic criteria of HIV-associated cognitive impairment

    Science.gov (United States)

    De Francesco, Davide; Leech, Robert; Sabin, Caroline A.; Winston, Alan

    2018-01-01

    Objective The reported prevalence of cognitive impairment remains similar to that reported in the pre-antiretroviral therapy era. This may be partially artefactual due to the methods used to diagnose impairment. In this study, we evaluated the diagnostic performance of the HIV-associated neurocognitive disorder (Frascati criteria) and global deficit score (GDS) methods in comparison to a new, multivariate method of diagnosis. Methods Using a simulated ‘normative’ dataset informed by real-world cognitive data from the observational Pharmacokinetic and Clinical Observations in PeoPle Over fiftY (POPPY) cohort study, we evaluated the apparent prevalence of cognitive impairment using the Frascati and GDS definitions, as well as a novel multivariate method based on the Mahalanobis distance. We then quantified the diagnostic properties (including positive and negative predictive values and accuracy) of each method, using bootstrapping with 10,000 replicates, with a separate ‘test’ dataset to which a pre-defined proportion of ‘impaired’ individuals had been added. Results The simulated normative dataset demonstrated that up to ~26% of a normative control population would be diagnosed with cognitive impairment with the Frascati criteria and ~20% with the GDS. In contrast, the multivariate Mahalanobis distance method identified impairment in ~5%. Using the test dataset, diagnostic accuracy [95% confidence intervals] and positive predictive value (PPV) was best for the multivariate method vs. Frascati and GDS (accuracy: 92.8% [90.3–95.2%] vs. 76.1% [72.1–80.0%] and 80.6% [76.6–84.5%] respectively; PPV: 61.2% [48.3–72.2%] vs. 29.4% [22.2–36.8%] and 33.9% [25.6–42.3%] respectively). Increasing the a priori false positive rate for the multivariate Mahalanobis distance method from 5% to 15% resulted in an increase in sensitivity from 77.4% (64.5–89.4%) to 92.2% (83.3–100%) at a cost of specificity from 94.5% (92.8–95.2%) to 85.0% (81.2–88

  9. Comparison of the diagnostic performances of diffusion parameters in diffusion weighted imaging and diffusion tensor imaging of breast lesions

    International Nuclear Information System (INIS)

    Cakir, Ozgur; Arslan, Arzu; Inan, Nagihan; Anık, Yonca; Sarısoy, Tahsin; Gumustas, Sevtap; Akansel, Gur

    2013-01-01

    Purpose: To evaluate the diagnostic efficiency of the diffusion parameters measured by conventional diffusion-weighted imaging (DWI) and diffusion tensor imaging (DTI) for discrimination of malignant breast lesions from benign lesions and the normal breast. Materials and methods: The study included 52 women with 55 breast lesions (30 malignant, 25 benign). DTI and DWI were performed complementary to dynamic contrast MRI at 3T. Apparent diffusion coefficient (ADC) of DWI, mean diffusivity (MD) and fractional anisotropy (FA) values of DTI were measured for lesions and contralateral breast parenchyma in each patient. We used b factors of 0, 50, 850, 1000 and 1500 s/mm 2 for DWI and b 0 and 1000 s/mm 2 for DTI. ADC, MD and FA values were compared between malignant and benign lesions, and the normal parenchyma by univariate and multivariate analyses. Results: Diffusion parameters showed no difference according to menopausal status in the normal breast. ADC and MD values of the malignant lesions were significantly lower than benign lesions and normal parenchyma (p = 0.001). The FA showed no statistical significance. With the cut-off values of ≤1.23 × 10 −3 mm 2 /s (b 0–1000 s/mm 2 ) and ≤1.12 × 10 −3 mm 2 /s (b 0–1500 s/mm 2 ), ADC showed 92.85% and 96.15% sensitivity; 72.22% and 73.52% PPV, respectively. With a cut-off value of ≤1.27 × 10 −3 mm 2 /s (b 1000 s/mm 2 ), MD was 100% sensitive with a PPV of 65.90%. Comparing the diagnostic performance of the parameters in DTI with DWI, we obtained similar efficiency of ADC with b values of 0,1000 and 0,1500 s/mm 2 and MD with a b value of 0, 1000 s/mm 2 (AUC = 0.82 ± 0.07). Conclusion: ADC of DWI and MD of DTI values provide significant discriminative factors for benign and malignant breast lesions. FA measurement was not discriminative. Supported with clinical and dynamic contrast MRI findings, DWI and DTI findings provide significant contribution to the final radiologic decision

  10. Comparison of the diagnostic performances of diffusion parameters in diffusion weighted imaging and diffusion tensor imaging of breast lesions

    Energy Technology Data Exchange (ETDEWEB)

    Cakir, Ozgur, E-mail: cakirozgur@hotmail.com; Arslan, Arzu, E-mail: arzu.s.arslan@gmail.com; Inan, Nagihan, E-mail: nagihaninan@yahoo.com.tr; Anık, Yonca, E-mail: yoncaanik@yahoo.com; Sarısoy, Tahsin, E-mail: htsarisoy@yahoo.com; Gumustas, Sevtap, E-mail: svtgumustas@yahoo.com; Akansel, Gur, E-mail: gakansel@gmail.com

    2013-12-01

    Purpose: To evaluate the diagnostic efficiency of the diffusion parameters measured by conventional diffusion-weighted imaging (DWI) and diffusion tensor imaging (DTI) for discrimination of malignant breast lesions from benign lesions and the normal breast. Materials and methods: The study included 52 women with 55 breast lesions (30 malignant, 25 benign). DTI and DWI were performed complementary to dynamic contrast MRI at 3T. Apparent diffusion coefficient (ADC) of DWI, mean diffusivity (MD) and fractional anisotropy (FA) values of DTI were measured for lesions and contralateral breast parenchyma in each patient. We used b factors of 0, 50, 850, 1000 and 1500 s/mm{sup 2} for DWI and b 0 and 1000 s/mm{sup 2} for DTI. ADC, MD and FA values were compared between malignant and benign lesions, and the normal parenchyma by univariate and multivariate analyses. Results: Diffusion parameters showed no difference according to menopausal status in the normal breast. ADC and MD values of the malignant lesions were significantly lower than benign lesions and normal parenchyma (p = 0.001). The FA showed no statistical significance. With the cut-off values of ≤1.23 × 10{sup −3} mm{sup 2}/s (b 0–1000 s/mm{sup 2}) and ≤1.12 × 10{sup −3} mm{sup 2}/s (b 0–1500 s/mm{sup 2}), ADC showed 92.85% and 96.15% sensitivity; 72.22% and 73.52% PPV, respectively. With a cut-off value of ≤1.27 × 10{sup −3} mm{sup 2}/s (b 1000 s/mm{sup 2}), MD was 100% sensitive with a PPV of 65.90%. Comparing the diagnostic performance of the parameters in DTI with DWI, we obtained similar efficiency of ADC with b values of 0,1000 and 0,1500 s/mm{sup 2} and MD with a b value of 0, 1000 s/mm{sup 2} (AUC = 0.82 ± 0.07). Conclusion: ADC of DWI and MD of DTI values provide significant discriminative factors for benign and malignant breast lesions. FA measurement was not discriminative. Supported with clinical and dynamic contrast MRI findings, DWI and DTI findings provide significant

  11. Diffusion-weighted MRI in prostatic lesions: Diagnostic performance of normalized ADC using normal peripheral prostatic zone as a reference

    Directory of Open Access Journals (Sweden)

    Tamer F. Taha Ali

    2018-03-01

    Full Text Available Aim of study: Evaluate the potential value of the normal peripheral zone as a reference organ to normalize prostatic lesion apparent diffusion coefficient (ADC to improve its evaluation of prostatic lesions. Patients and methods: This prospective study included 38 patients with clinical suspicion of cancer prostate (increased PSA levels (>4 ng/ml, hard prostate in digital rectal examination and who are scheduled to undergo a TRUS-guided biopsy. Conventional and DW-MRI was done and ADC was calculated. The normalized ADC value was calculated by dividing the ADC of lesion by ADC of reference site (healthy peripheral zone. DWI-MRI results were compared to the results of biopsy. Comparison of ADCs and nADCs of benign and malignant lesions was done. Receiver operating characteristics (ROC curve analysis was done. Results: The patients were classified by histopathology into non-malignant group (16 patients and malignant group (22 patients. Significant negative correlation between ADC and normalized ADC (nADC and malignancy was detected. There was no significant difference between the mean ADC of peripheral health prostatic zones (PZ between benign and malignant cases (2.221 ± 0.356 versus 1.99 ± 0.538x10−3 mm2/sec, p = 0.144.There was significant difference between the mean ADC and mean nADC in benign and malignant lesions (1.049 ± 0.217 versus 0.659 ± 0.221x10−3 mm2/sec, p < 0.001 and (0.475 ± 0.055 versus 0.328 ± 0.044, p < 0.001 respectively.There was significant higher diagnostic performance of nADC than ADC with ADC Cut-off value 0.75 × 10−3 mm2/sec and nADC cut-off value 0.39 could significantly differentiate between benign and malignant lesion with sensitivity, specificity, PPV,NPV of 86.36,75,82.61 and 80% respectively, p < 0.0001 for ADC and 95.45, 93.75, 95.45 and 93.75%, p < 0.0001 for nADC. Conclusion: diagnostic performance of nADC using normal peripheral zone is higher than

  12. Diagnostic performance of fecal quantitative real-time polymerase chain reaction for detection of Lawsonia intracellularis–associated proliferative enteropathy in nursery pigs

    DEFF Research Database (Denmark)

    Pedersen, Ken Steen; Stege, Helle; Jensen, Tim Kåre

    2013-01-01

    Quantitative polymerase chain reaction (qPCR) tests for detection and quantification of Lawsonia intracellularis in feces from pigs have been developed. The objective of the current study was to evaluate the diagnostic performance of a fecal qPCR test for detection of nursery pigs with L. intrace......Quantitative polymerase chain reaction (qPCR) tests for detection and quantification of Lawsonia intracellularis in feces from pigs have been developed. The objective of the current study was to evaluate the diagnostic performance of a fecal qPCR test for detection of nursery pigs with L...

  13. Diagnostic performance of FDG PET or PET/CT in prosthetic infection after arthroplasty: a meta-analysis

    International Nuclear Information System (INIS)

    Jin, H.; Yuan, L.; Li, C.; Kan, Y.; Yang, J.; Hao, R.

    2014-01-01

    The purpose of this study was to systematically review and perform a meta-analysis of published data regarding the diagnostic performance of positron emission tomography (PET) or PET/computed tomography (PET/CT) in prosthetic infection after arthroplasty. A comprehensive computer literature search of studies published through May 31, 2012 regarding PET or PET/CT in patients suspicious of prosthetic infection was performed in PubMed/MEDLINE, Embase and Scopus databases. Pooled sensitivity and specificity of PET or PET/CT in patients suspicious of prosthetic infection on a per prosthesis-based analysis were calculated. The area under the receiver-operating characteristic (ROC) curve was calculated to measure the accuracy of PET or PET/CT in patients with suspicious of prosthetic infection. Fourteen studies comprising 838 prosthesis with suspicious of prosthetic infection after arthroplasty were included in this meta-analysis. The pooled sensitivity of PET or PET/CT in detecting prosthetic infection was 86% (95% confidence interval [CI] 82-90%) on a per prosthesis-based analysis. The pooled specificity of PET or PET/CT in detecting prosthetic infection was 86% (95% CI 83-89%) on a per prosthesis-based analysis. The area under the ROC curve was 0.93 on a per prosthesis-based analysis. In patients suspicious of prosthetic infection, FDG PET or PET/CT demonstrated high sensitivity and specificity. FDG PET or PET/CT are accurate methods in this setting. Nevertheless, possible sources of false positive results and influcing factors should kept in mind.

  14. Autonomous Diagnostic Imaging Performed by Untrained Operator Using Augmented Reality as a Form of "Just-in-Time" Training

    Science.gov (United States)

    Martin, David S.; Wang, Lui; Laurie, Steven S.; Lee, Stuart M. C.; Stenger, Michael B.

    2017-01-01

    We will address the Human Factors and Performance Team, "Risk of performance errors due to training deficiencies" by improving the JIT training materials for ultrasound and OCT imaging by providing advanced guidance in a detailed, timely, and user-friendly manner. Specifically, we will (1) develop an audio-visual tutorial using AR that guides non-experts through an abdominal trauma ultrasound protocol; (2) develop an audio-visual tutorial using AR to guide an untrained operator through the acquisition of OCT images; (3) evaluate the quality of abdominal ultrasound and OCT images acquired by untrained operators using AR guidance compared to images acquired using traditional JIT techniques (laptop-based training conducted before image acquisition); and (4) compare the time required to complete imaging studies using AR tutorials with images acquired using current JIT practices to identify areas for time efficiency improvements. Two groups of subjects will be recruited to participate in this study. Operator-subjects, without previous experience in ultrasound or OCT, will be asked to perform both procedures using either the JIT training with AR technology or the traditional JIT training via laptop. Images acquired by inexperienced operator-subjects will be scored by experts in that imaging modality for diagnostic and research quality; experts will be blinded to the form of JIT used to acquire the images. Operator-subjects also will be asked to submit feedback to improve the training modules used during the scans to improve future training modules. Scanned-subjects will be a small group individuals from whom all images will be acquired.

  15. Autonomous Diagnostic Imaging Performed by Untrained Operators using Augmented Reality as a Form of "Just-in-Time" Training

    Science.gov (United States)

    Martin, D. S.; Wang, L.; Laurie, S. S.; Lee, S. M. C.; Fleischer, A. C.; Gibson, C. R.; Stenger, M. B.

    2017-01-01

    We will address the Human Factors and Performance Team, "Risk of performance errors due to training deficiencies" by improving the JIT training materials for ultrasound and OCT imaging by providing advanced guidance in a detailed, timely, and user-friendly manner. Specifically, we will (1) develop an audio-visual tutorial using AR that guides non-experts through an abdominal trauma ultrasound protocol; (2) develop an audio-visual tutorial using AR to guide an untrained operator through the acquisition of OCT images; (3) evaluate the quality of abdominal ultrasound and OCT images acquired by untrained operators using AR guidance compared to images acquired using traditional JIT techniques (laptop-based training conducted before image acquisition); and (4) compare the time required to complete imaging studies using AR tutorials with images acquired using current JIT practices to identify areas for time efficiency improvements. Two groups of subjects will be recruited to participate in this study. Operator-subjects, without previous experience in ultrasound or OCT, will be asked to perform both procedures using either the JIT training with AR technology or the traditional JIT training via laptop. Images acquired by inexperienced operator-subjects will be scored by experts in that imaging modality for diagnostic and research quality; experts will be blinded to the form of JIT used to acquire the images. Operator-subjects also will be asked to submit feedback to improve the training modules used during the scans to improve future training modules. Scanned-subjects will be a small group individuals from whom all images will be acquired.

  16. Diagnostic performance of FDG PET or PET/CT in prosthetic infection after arthroplasty: a meta-analysis.

    Science.gov (United States)

    Jin, H; Yuan, L; Li, C; Kan, Y; Hao, R; Yang, J

    2014-03-01

    The purpose of this study was to systematically review and perform a meta-analysis of published data regarding the diagnostic performance of positron emission tomography (PET) or PET/computed tomography (PET/CT) in prosthetic infection after arthroplasty. A comprehensive computer literature search of studies published through May 31, 2012 regarding PET or PET/CT in patients suspicious of prosthetic infection was performed in PubMed/MEDLINE, Embase and Scopus databases. Pooled sensitivity and specificity of PET or PET/CT in patients suspicious of prosthetic infection on a per prosthesis-based analysis were calculated. The area under the receiver-operating characteristic (ROC) curve was calculated to measure the accuracy of PET or PET/CT in patients with suspicious of prosthetic infection. Fourteen studies comprising 838 prosthesis with suspicious of prosthetic infection after arthroplasty were included in this meta-analysis. The pooled sensitivity of PET or PET/CT in detecting prosthetic infection was 86% (95% confidence interval [CI] 82-90%) on a per prosthesis-based analysis. The pooled specificity of PET or PET/CT in detecting prosthetic infection was 86% (95% CI 83-89%) on a per prosthesis-based analysis. The area under the ROC curve was 0.93 on a per prosthesis-based analysis. In patients suspicious of prosthetic infection, FDG PET or PET/CT demonstrated high sensitivity and specificity. FDG PET or PET/CT are accurate methods in this setting. Nevertheless, possible sources of false positive results and influcing factors should kept in mind.

  17. LAT Onboard Science: Gamma-Ray Burst Identification

    International Nuclear Information System (INIS)

    Kuehn, Frederick; Hughes, Richard; Smith, Patrick; Winer, Brian; Bonnell, Jerry; Norris, Jay; Ritz, Steven; Russell, James

    2007-01-01

    The main goal of the Large Area Telescope (LAT) onboard science program is to provide quick identification and localization of Gamma Ray Bursts (GRB) onboard the LAT for follow-up observations by other observatories. The GRB identification and localization algorithm will provide celestial coordinates with an error region that will be distributed via the Gamma ray burst Coordinate Network (GCN). We present results that show our sensitivity to bursts as characterized using Monte Carlo simulations of the GLAST observatory. We describe and characterize the method of onboard track determination and the GRB identification and localization algorithm. Onboard track determination is considerably different than in the on-ground case, resulting in a substantially altered point spread function. The algorithm contains tunable parameters which may be adjusted after launch when real bursts characteristics at very high energies have been identified

  18. Onboard Blackbody Calibrator Component Development for IR Remote Sensing Instrumentation

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of this study is to apply and to provide a reliable, stable durable onboard blackbody calibrator to future Earth Science missions by infusing the new...

  19. Diagnostic performance of direct traction MR arthrography of the hip: detection of chondral and labral lesions with arthroscopic comparison

    International Nuclear Information System (INIS)

    Schmaranzer, Florian; Klauser, Andrea; Henninger, Benjamin; Kogler, Michael; Schmaranzer, Ehrenfried; Forstner, Thomas; Reichkendler, Markus

    2015-01-01

    To assess diagnostic performance of traction MR arthrography of the hip in detection and grading of chondral and labral lesions with arthroscopic comparison. Seventy-five MR arthrograms obtained ± traction of 73 consecutive patients (mean age, 34.5 years; range, 14-54 years) who underwent arthroscopy were included. Traction technique included weight-adapted traction (15-23 kg), a supporting plate for the contralateral leg, and intra-articular injection of 18-27 ml (local anaesthetic and contrast agent). Patients reported on neuropraxia and on pain. Two blinded readers independently assessed femoroacetabular cartilage and labrum lesions which were correlated with arthroscopy. Interobserver agreement was calculated using κ values. Joint distraction ± traction was evaluated in consensus. No procedure had to be stopped. There were no cases of neuropraxia. Accuracy for detection of labral lesions was 92 %/93 %, 91 %/83 % for acetabular lesions, and 92 %/88 % for femoral cartilage lesions for reader 1/reader 2, respectively. Interobserver agreement was moderate (κ = 0.58) for grading of labrum lesions and substantial (κ = 0.7, κ = 0.68) for grading of acetabular and femoral cartilage lesions. Joint distraction was achieved in 72/75 and 14/75 hips with/without traction, respectively. Traction MR arthrography safely enabled accurate detection and grading of labral and chondral lesions. (orig.)

  20. Diagnostic performance of direct traction MR arthrography of the hip: detection of chondral and labral lesions with arthroscopic comparison

    Energy Technology Data Exchange (ETDEWEB)

    Schmaranzer, Florian; Klauser, Andrea; Henninger, Benjamin [Medical University Innsbruck, Department of Radiology, Innsbruck (Austria); Kogler, Michael; Schmaranzer, Ehrenfried [District Hospital St. Johann in Tyrol, Department of Radiology, St. Johann in Tyrol (Austria); Forstner, Thomas [Johannes Keppler University, Department for Applied Systems Research and Statistics, Linz (Austria); Reichkendler, Markus [District Hospital St. Johann in Tyrol, Department of Orthopedic Surgery, St. Johann in Tyrol (Austria)

    2015-06-01

    To assess diagnostic performance of traction MR arthrography of the hip in detection and grading of chondral and labral lesions with arthroscopic comparison. Seventy-five MR arthrograms obtained ± traction of 73 consecutive patients (mean age, 34.5 years; range, 14-54 years) who underwent arthroscopy were included. Traction technique included weight-adapted traction (15-23 kg), a supporting plate for the contralateral leg, and intra-articular injection of 18-27 ml (local anaesthetic and contrast agent). Patients reported on neuropraxia and on pain. Two blinded readers independently assessed femoroacetabular cartilage and labrum lesions which were correlated with arthroscopy. Interobserver agreement was calculated using κ values. Joint distraction ± traction was evaluated in consensus. No procedure had to be stopped. There were no cases of neuropraxia. Accuracy for detection of labral lesions was 92 %/93 %, 91 %/83 % for acetabular lesions, and 92 %/88 % for femoral cartilage lesions for reader 1/reader 2, respectively. Interobserver agreement was moderate (κ = 0.58) for grading of labrum lesions and substantial (κ = 0.7, κ = 0.68) for grading of acetabular and femoral cartilage lesions. Joint distraction was achieved in 72/75 and 14/75 hips with/without traction, respectively. Traction MR arthrography safely enabled accurate detection and grading of labral and chondral lesions. (orig.)

  1. Roll-to-roll manufacturing of amorphous silicon alloy solar cells with in situ cell performance diagnostics

    International Nuclear Information System (INIS)

    Izu, M.; Ellison, T.

    2003-01-01

    In order to meet the price target necessary for widespread use of solar cell products, Energy Conversion Devices, Inc., ECD, has developed and commercialized a continuous roll-to-roll manufacturing technology for the production of a-Si alloy solar cells. Since the early 1980s, we have advanced this technology from a small-scale pilot machine to a large-scale production machine. In 2002, ECD commissioned a 30 MW per year machine for United Solar Systems Corp. in Auburn Hills, Michigan. The RF PECVD a-Si alloy solar cell processor, designed and built by ECD, deposits triple-junction solar cell materials consisting of nine layers of a-Si alloys in a continuous roll-to-roll operation simultaneously on six coils of 130 μm thick, 0.36 m wide, 2.6 km long stainless-steel substrate at 1 cm/s. In order to minimize production losses due to undetected deviations of production conditions and carry on a continuous program of device optimization, we have developed and are incorporating in situ cell performance diagnostic systems. (author)

  2. [The diagnostic performance of color Doppler ultrasonography for newborn four cases of midgut volvulus accompanied by intestinal malrotation].

    Science.gov (United States)

    Ikeshima, Yukari; Hisano, Katsuya; Morisawa, Takeshi; Inoue, Kozue; Shimamoto, Masahiro; Koujitani, Toshiaki; Yonetani, Masahiko; Yasufuku, Masao

    2014-03-01

    Midgut volvulus accompanied by intestinal malrotation is classified as a surgical emergency disease of the newborn, which emerges with the bilious vomiting or melena. This report presents four patients of this disease in our hospital, evaluated by color Doppler ultrasonography before surgical operation. All four patients were presented by bilious vomiting at the onset. By color Doppler ultrasonography method, the whirlpool sign which is the view of intestine and superior mesenteric vein rotated around with the axis of superior mesenteric artery, were shown in all cases. This whirlpool sign led to the diagnosis of midgut volvulus accompanied by intestinal malrotation. Intestinal contrast imaging was tested in three patients for the purpose of confirming the diagnosis. Repair of the volvulus and a ladd operation was performed in all four patients, without the excision of intestine because of no intestinal ischemic change. The clinical courses of four cases were good, and all patients were discharged within 17 days. Early diagnosis and timely surgical operation are essential for decreasing the possibility of occurring intestinal ischemic changes and improving clinical outcome after surgical operation. We propose that color Doppler ultrasonography is the powerful tool for the diagnosis of this disease, especially for the newborn, for whom the available diagnostic tests are limited.

  3. Neon dewar for the X-ray spectrometer onboard Suzaku

    Energy Technology Data Exchange (ETDEWEB)

    Fujimoto, R. [Institute of Space and Astronautical Science (ISAS), JAXA, 3-1-1 Yoshinodai, Sagamihara 229-8510 (Japan)]. E-mail: fujimoto@isas.jaxa.jp; Mitsuda, K. [Institute of Space and Astronautical Science (ISAS), JAXA, 3-1-1 Yoshinodai, Sagamihara 229-8510 (Japan); Hirabayashi, M. [Sumitomo Heavy Industries, Ltd. (SHI), 5-2 Sobiraki-cho, Niihama 792-8588 (Japan); Narasaki, K. [Sumitomo Heavy Industries, Ltd. (SHI), 5-2 Sobiraki-cho, Niihama 792-8588 (Japan); Breon, S. [NASA Goddard Space Flight Center (GSFC), Greenbelt, MD 20771 (United States); Boyle, R. [NASA Goddard Space Flight Center (GSFC), Greenbelt, MD 20771 (United States); Di Pirro, M. [NASA Goddard Space Flight Center (GSFC), Greenbelt, MD 20771 (United States); Volz, S.M. [NASA Headquarters, Washington, DC 20546-0001 (United States); Kelley, R.L. [NASA Goddard Space Flight Center (GSFC), Greenbelt, MD 20771 (United States)

    2006-04-15

    The X-ray spectrometer (XRS) onboard Suzaku is the first X-ray microcalorimeter array in orbit. The sensor array is operated at 60mK, which is attained by an adiabatic demagnetization refrigerator and superfluid liquid helium. The neon dewar is a vacuum-insulated container for the XRS. The requirements for the XRS dewar are to maintain the detector and the cryogenic system under the mechanical environment at launch ({approx}15G), and to attain a lifetime of 3 years in a near-earth orbit. It is characterized with adoptions of solid neon as the second cryogen and a mechanical cooler, design optimization of the support straps for the neon tank to reduce the heat load as much as possible, and shock absorbers to mitigate the mechanical environment at launch. Microphonics from the mechanical cooler was one of the concerns for the detector performance, but the ground test results proved that they do not interfere with the detector. After about 1 month in orbit, its thermal performance showed that the dewar potentially achieves its design goals.

  4. Diagnostic performance of a biomarker panel as a negative predictor for acute appendicitis in adult ED patients with abdominal pain.

    Science.gov (United States)

    Huckins, David S; Copeland, Karen; Self, Wesley; Vance, Cheryl; Hendry, Phyllis; Borg, Keith; Gogain, Joseph

    2017-03-01

    Evaluate the diagnostic accuracy of the APPY1TM biomarker panel, previously described for use in pediatric patients, for identifying adult ED patients with abdominal pain who are at low risk of acute appendicitis. This study prospectively enrolled subjects >18years of age presenting to seven U.S. emergency departments with pain suggesting possible acute appendicitis. The APPY1 panel was performed on blood samples drawn from each patient at the time of initial evaluation and results were correlated with the final diagnosis either positive or negative for acute appendicitis. 431 patients were enrolled with 422 completing all aspects of the study. The APPY1 biomarker panel exhibited a sensitivity of 97.5% (95% CI, 91.3-99.3%), a negative predictive value of 98.4% (95% CI, 94.4-99.6%), a negative likelihood ratio of 0.07 (95% CI, 0.02-0.27), with a specificity of 36.5% (95% CI, 31.6-41.8%) for acute appendicitis. The panel correctly identified 125 of 342 (36.6%) patients who did not have appendicitis with 2 (2.5%) false negatives. The CT utilization rate in this population was 72.7% (307/422). Of 307 CT scans, 232 were done for patients who did not have appendicitis and 79 (34%) of these patients were correctly identified as negative with "low risk" biomarker panel results, representing 26% (79/307) of all CT scans performed. This biomarker panel exhibited high sensitivity and negative predictive value for acute appendicitis in this prospective adult cohort, thereby potentially reducing the dependence on CT for the evaluation of possible acute appendicitis. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Diagnostic performance of conventional diffusion weighted imaging and diffusion tensor imaging for the liver fibrosis and inflammation

    International Nuclear Information System (INIS)

    Tosun, Mesude; Inan, Nagihan; Sarisoy, Hasan Tahsin; Akansel, Gur; Gumustas, Sevtap; Gürbüz, Yeşim; Demirci, Ali

    2013-01-01

    Objective: To evaluate the diagnostic accuracy of liver apparent diffusion coefficient (ADC) measured with conventional diffusion-weighted imaging (CDI) and diffusion tensor imaging (DTI) for the diagnosis of liver fibrosis and inflammation. Materials and methods: Thirty-seven patients with histologic diagnosis of chronic viral hepatitis and 34 healthy volunteers were included in this prospective study. All patients and healthy volunteers were examined by 3 T MRI. CDI and DTI were performed using a breath-hold single-shot echo-planar spin echo sequence with b factors of 0 and 1000 s/mm 2 . ADCs were obtained with CDI and DTI. Histopathologically, fibrosis of the liver parenchyma was classified with the use of a 5-point scale (0–4) and inflammation was classified with use of a 4-point scale (0–3) in accordance with the METAVIR score. Quantitatively, signal intensity and the ADCs of the liver parenchyma were compared between patients stratified by fibrosis stage and inflammation grade. Results: With a b factor of 1000 s/mm 2 , the signal intensity of the cirrhotic livers was significantly higher than those of the normal volunteers. In addition, ADCs reconstructed from CDI and DTI of the patients were significantly lower than those of the normal volunteers. Liver ADC values inversely correlated with fibrosis and inflammation but there was only statistically significant for inflammatory grading. CDI performed better than DTI for the diagnosis of fibrosis and inflammation. Conclusion: ADC values measured with CDI and DTI may help in the detection of liver fibrosis. They may also give contributory to the inflammatory grading, particularly in distinguishing high from low grade

  6. Confronting Decision Cliffs: Diagnostic Assessment of Multi-Objective Evolutionary Algorithms' Performance for Addressing Uncertain Environmental Thresholds

    Science.gov (United States)

    Ward, V. L.; Singh, R.; Reed, P. M.; Keller, K.

    2014-12-01

    As water resources problems typically involve several stakeholders with conflicting objectives, multi-objective evolutionary algorithms (MOEAs) are now key tools for understanding management tradeoffs. Given the growing complexity of water planning problems, it is important to establish if an algorithm can consistently perform well on a given class of problems. This knowledge allows the decision analyst to focus on eliciting and evaluating appropriate problem formulations. This study proposes a multi-objective adaptation of the classic environmental economics "Lake Problem" as a computationally simple but mathematically challenging MOEA benchmarking problem. The lake problem abstracts a fictional town on a lake which hopes to maximize its economic benefit without degrading the lake's water quality to a eutrophic (polluted) state through excessive phosphorus loading. The problem poses the challenge of maintaining economic activity while confronting the uncertainty of potentially crossing a nonlinear and potentially irreversible pollution threshold beyond which the lake is eutrophic. Objectives for optimization are maximizing economic benefit from lake pollution, maximizing water quality, maximizing the reliability of remaining below the environmental threshold, and minimizing the probability that the town will have to drastically change pollution policies in any given year. The multi-objective formulation incorporates uncertainty with a stochastic phosphorus inflow abstracting non-point source pollution. We performed comprehensive diagnostics using 6 algorithms: Borg, MOEAD, eMOEA, eNSGAII, GDE3, and NSGAII to ascertain their controllability, reliability, efficiency, and effectiveness. The lake problem abstracts elements of many current water resources and climate related management applications where there is the potential for crossing irreversible, nonlinear thresholds. We show that many modern MOEAs can fail on this test problem, indicating its suitability as a

  7. Diagnostic performance of conventional diffusion weighted imaging and diffusion tensor imaging for the liver fibrosis and inflammation

    Energy Technology Data Exchange (ETDEWEB)

    Tosun, Mesude, E-mail: mesude.tosun@kocaeli.edu.tr [Department of Radiology, School of Medicine, University of Kocaeli (Turkey); Inan, Nagihan, E-mail: inannagihan@ekolay.net [Department of Radiology, School of Medicine, University of Kocaeli (Turkey); Sarisoy, Hasan Tahsin, E-mail: htssarisoy@yahoo.com [Department of Radiology, School of Medicine, University of Kocaeli (Turkey); Akansel, Gur, E-mail: gakansel@gmail.com [Department of Radiology, School of Medicine, University of Kocaeli (Turkey); Gumustas, Sevtap, E-mail: svtgumustas@hotmail.com [Department of Radiology, School of Medicine, University of Kocaeli (Turkey); Gürbüz, Yeşim, E-mail: yesimgurbuz2002@yahoo.com [Department of Pathology, School of Medicine, University of Kocaeli (Turkey); Demirci, Ali, E-mail: alidemirci@kocaeli.edu.tr [Department of Radiology, School of Medicine, University of Kocaeli (Turkey)

    2013-02-15

    Objective: To evaluate the diagnostic accuracy of liver apparent diffusion coefficient (ADC) measured with conventional diffusion-weighted imaging (CDI) and diffusion tensor imaging (DTI) for the diagnosis of liver fibrosis and inflammation. Materials and methods: Thirty-seven patients with histologic diagnosis of chronic viral hepatitis and 34 healthy volunteers were included in this prospective study. All patients and healthy volunteers were examined by 3 T MRI. CDI and DTI were performed using a breath-hold single-shot echo-planar spin echo sequence with b factors of 0 and 1000 s/mm{sup 2}. ADCs were obtained with CDI and DTI. Histopathologically, fibrosis of the liver parenchyma was classified with the use of a 5-point scale (0–4) and inflammation was classified with use of a 4-point scale (0–3) in accordance with the METAVIR score. Quantitatively, signal intensity and the ADCs of the liver parenchyma were compared between patients stratified by fibrosis stage and inflammation grade. Results: With a b factor of 1000 s/mm{sup 2}, the signal intensity of the cirrhotic livers was significantly higher than those of the normal volunteers. In addition, ADCs reconstructed from CDI and DTI of the patients were significantly lower than those of the normal volunteers. Liver ADC values inversely correlated with fibrosis and inflammation but there was only statistically significant for inflammatory grading. CDI performed better than DTI for the diagnosis of fibrosis and inflammation. Conclusion: ADC values measured with CDI and DTI may help in the detection of liver fibrosis. They may also give contributory to the inflammatory grading, particularly in distinguishing high from low grade.

  8. Effects of disease severity distribution on the performance of quantitative diagnostic methods and proposal of a novel 'V-plot' methodology to display accuracy values.

    Science.gov (United States)

    Petraco, Ricardo; Dehbi, Hakim-Moulay; Howard, James P; Shun-Shin, Matthew J; Sen, Sayan; Nijjer, Sukhjinder S; Mayet, Jamil; Davies, Justin E; Francis, Darrel P

    2018-01-01

    Diagnostic accuracy is widely accepted by researchers and clinicians as an optimal expression of a test's performance. The aim of this study was to evaluate the effects of disease severity distribution on values of diagnostic accuracy as well as propose a sample-independent methodology to calculate and display accuracy of diagnostic tests. We evaluated the diagnostic relationship between two hypothetical methods to measure serum cholesterol (Chol rapid and Chol gold ) by generating samples with statistical software and (1) keeping the numerical relationship between methods unchanged and (2) changing the distribution of cholesterol values. Metrics of categorical agreement were calculated (accuracy, sensitivity and specificity). Finally, a novel methodology to display and calculate accuracy values was presented (the V-plot of accuracies). No single value of diagnostic accuracy can be used to describe the relationship between tests, as accuracy is a metric heavily affected by the underlying sample distribution. Our novel proposed methodology, the V-plot of accuracies, can be used as a sample-independent measure of a test performance against a reference gold standard.

  9. Effects of disease severity distribution on the performance of quantitative diagnostic methods and proposal of a novel ‘V-plot’ methodology to display accuracy values

    Science.gov (United States)

    Dehbi, Hakim-Moulay; Howard, James P; Shun-Shin, Matthew J; Sen, Sayan; Nijjer, Sukhjinder S; Mayet, Jamil; Davies, Justin E; Francis, Darrel P

    2018-01-01

    Background Diagnostic accuracy is widely accepted by researchers and clinicians as an optimal expression of a test’s performance. The aim of this study was to evaluate the effects of disease severity distribution on values of diagnostic accuracy as well as propose a sample-independent methodology to calculate and display accuracy of diagnostic tests. Methods and findings We evaluated the diagnostic relationship between two hypothetical methods to measure serum cholesterol (Cholrapid and Cholgold) by generating samples with statistical software and (1) keeping the numerical relationship between methods unchanged and (2) changing the distribution of cholesterol values. Metrics of categorical agreement were calculated (accuracy, sensitivity and specificity). Finally, a novel methodology to display and calculate accuracy values was presented (the V-plot of accuracies). Conclusion No single value of diagnostic accuracy can be used to describe the relationship between tests, as accuracy is a metric heavily affected by the underlying sample distribution. Our novel proposed methodology, the V-plot of accuracies, can be used as a sample-independent measure of a test performance against a reference gold standard. PMID:29387424

  10. Evaluation of lymph node status after neoadjuvant chemotherapy in breast cancer patients: comparison of diagnostic performance of ultrasound, MRI and ¹⁸F-FDG PET/CT.

    Science.gov (United States)

    You, S; Kang, D K; Jung, Y S; An, Y-S; Jeon, G S; Kim, T H

    2015-08-01

    To evaluate the diagnostic performance of ultrasound, MRI and fluorine-18 fludeoxyglucose positron emission tomography (¹⁸F-FDG PET)/CT for the diagnosis of metastatic axillary lymph node (ALN) after neoadjuvant chemotherapy (NAC) and to find out histopathological factors affecting the diagnostic performance of these imaging modalities. From January 2012 to November 2014, 191 consecutive patients with breast cancer who underwent NAC before surgery were retrospectively reviewed. We included 139 patients with ALN metastasis that was confirmed on fine needle aspiration or core needle biopsy at initial diagnosis. After NAC, 39 (28%) patients showed negative conversion of ALN on surgical specimens of sentinel lymph node (LN) or ALN. The sensitivity of ultrasound, MRI and PET/CT was 50% (48/96), 72% (70/97) and 22% (16/73), respectively. The specificity of ultrasound, MRI and PET/CT was 77% (30/39), 54% (21/39) and 85% (22/26), respectively. The Az value of combination of ultrasound and PET/CT was the highest (0.634) followed by ultrasound (0.626) and combination of ultrasound, MRI and PET/CT (0.617). The size of tumour deposit in LN and oestrogen receptor was significantly associated with the diagnostic performance of ultrasound (p performance of PET/CT (p = 0.023, p = 0.002, p = 0.036, p = 0.044 and p = 0.008, respectively). On multivariate logistic regression analysis, size of tumour deposit within LN was identified as being independently associated with diagnostic performance of ultrasound [odds ratio, 13.07; 95% confidence interval (CI), 2.95-57.96] and PET/CT (odds ratio, 6.47; 95% CI, 1.407-29.737). Combination of three imaging modalities showed the highest sensitivity, and PET/CT showed the highest specificity for the evaluation of ALN metastasis after NAC. Ultrasound alone or combination of ultrasound and PET/CT showed the highest positive-predictive value. The size of tumour deposit within ALN was significantly associated with

  11. Performance of the Directigen EZ Flu A+B rapid influenza diagnostic test to detect pandemic influenza A/H1N1 2009.

    Science.gov (United States)

    Boyanton, Bobby L; Almradi, Amro; Mehta, Tejal; Robinson-Dunn, Barbara

    2014-04-01

    The Directigen EZ Flu A+B rapid influenza diagnostic test, as compared to real-time reverse transcriptase polymerase chain reaction, demonstrated suboptimal performance to detect pandemic influenza A/H1N1 2009. Age- and viral load-stratified test sensitivity ranged from 33.3 to 84.6% and 0 to 100%, respectively. © 2013.

  12. An Examination of Pennsylvania's Classroom Diagnostic Testing as a Predictive Model of Pennsylvania System of School Assessment Performance

    Science.gov (United States)

    Matsanka, Christopher

    2017-01-01

    The purpose of this non-experimental quantitative study was to investigate the relationship between Pennsylvania's Classroom Diagnostic Tools (CDT) interim assessments and the state-mandated Pennsylvania System of School Assessment (PSSA) and to create linear regression equations that could be used as models to predict student performance on the…

  13. Use of the Performance Diagnostic Checklist to Select an Intervention Designed to Increase the Offering of Promotional Stamps at Two Sites of a Restaurant Franchise

    Science.gov (United States)

    Rodriguez, Manuel; Wilder, David A.; Therrien, Kelly; Wine, Byron; Miranti, Reylissa; Daratany, Kenneth; Salume, Gloria; Baranovsky, Greg; Rodriquez, Matias

    2006-01-01

    The performance diagnostic checklist (PDC) was administered to examine the variables influencing the offering of promotional stamps by employees at two sites of a restaurant franchise. PDC results suggested that a lack of appropriate antecedents, equipment and processes, and consequences were responsible for the deficits. Based on these results,…

  14. Comparison of the diagnostic performance of digital breast tomosynthesis and magnetic resonance imaging added to digital mammography in women with known breast cancers

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Won Hwa; Chang, Jung Min; Moon, Woo Kyung [Seoul National University Hospital, Department of Radiology, 101 Daehangno, Jongno-gu, Seoul (Korea, Republic of); Moon, Hyeong-Gon [Seoul National University Hospital, Department of Surgery, Seoul (Korea, Republic of); Yi, Ann [Seoul National University Hospital, Department of Radiology, Gangnan Healthcare Center, Seoul (Korea, Republic of); Koo, Hye Ryoung [Hanyang University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Gweon, Hye Mi [Yonsei University College of Medicine, Department of Radiology, Gangnam Severance Hospital, Seoul (Korea, Republic of)

    2016-06-15

    To compare the diagnostic performance of digital breast tomosynthesis (DBT) and magnetic resonance imaging (MRI) added to mammography in women with known breast cancers. Three radiologists independently reviewed image sets of 172 patients with 184 cancers; mammography alone, DBT plus mammography and MRI plus mammography, and scored for cancer probability using the Breast Imaging Reporting and Data System (BI-RADS). Jack-knife alternative free-response receiver-operating characteristic (JAFROC), which allows diagnostic performance estimation using single lesion as a statistical unit in a cancer-only population, was used. Sensitivity and positive predictive value (PPV) were compared using the McNemar and Fisher-exact tests. The JAFROC figures of merit (FOMs) was lower in DBT plus mammography (0.937) than MRI plus mammography (0.978, P = 0.0006) but higher than mammography alone (0.900, P = 0.0013). The sensitivity was lower in DBT plus mammography (88.2 %) than MRI plus mammography (97.8 %) but higher than mammography alone (78.3 %, both P < 0.0001). The PPV was significantly higher in DBT plus mammography (93.3 %) than MRI plus mammography (89.6 %, P = 0.0282). DBT provided lower diagnostic performance than MRI as an adjunctive imaging to mammography. However, DBT had higher diagnostic performance than mammography and higher PPV than MRI. (orig.)

  15. Diagnostic performance of an indirect enzyme-linked immunosorbent assay (ELISA) to detect bovine leukemia virus antibodies in bulk-tank milk samples

    Science.gov (United States)

    Nekouei, Omid; Durocher, Jean; Keefe, Greg

    2016-01-01

    This study assessed the diagnostic performance of a commercial ELISA for detecting bovine leukemia virus antibodies in bulk-tank milk samples from eastern Canada. Sensitivity and specificity of the test were estimated at 97.2% and 100%, respectively. The test was recommended as a cost-efficient tool for large-scale screening programs. PMID:27429469

  16. Diagnostic performance of CT-arthrography and 1.5T MR-arthrography for the assessment of glenohumeral joint cartilage: a comparative study with arthroscopic correlation

    Energy Technology Data Exchange (ETDEWEB)

    Omoumi, Patrick [Cliniques Universitaires St Luc - Universite Catholique de Louvain, Department of Radiology, Brussels (Belgium); Lausanne University Hospital, Department of Radiology, Lausanne (Switzerland); Rubini, Alexandra; Berg, Bruno C. vande; Lecouvet, Frederic E. [Cliniques Universitaires St Luc - Universite Catholique de Louvain, Department of Radiology, Brussels (Belgium); Dubuc, Jean-Emile [Cliniques Universitaires St Luc - Universite Catholique de Louvain, Department of Orthopedic Surgery, Brussels (Belgium)

    2015-04-01

    To compare the diagnostic performance of multi-detector CT arthrography (CTA) and 1.5-T MR arthrography (MRA) in detecting hyaline cartilage lesions of the shoulder, with arthroscopic correlation. CTA and MRA prospectively obtained in 56 consecutive patients following the same arthrographic procedure were independently evaluated for glenohumeral cartilage lesions (modified Outerbridge grade ≥2 and grade 4) by two musculoskeletal radiologists. The cartilage surface was divided in 18 anatomical areas. Arthroscopy was taken as the reference standard. Diagnostic performance of CTA and MRA was compared using ROC analysis. Interobserver and intraobserver agreement was determined by κ statistics. Sensitivity and specificity of CTA varied from 46.4 to 82.4 % and from 89.0 to 95.9 % respectively; sensitivity and specificity of MRA varied from 31.9 to 66.2 % and from 91.1 to 97.5 % respectively. Diagnostic performance of CTA was statistically significantly better than MRA for both readers (all p ≤ 0.04). Interobserver agreement for the evaluation of cartilage lesions was substantial with CTA (κ = 0.63) and moderate with MRA (κ = 0.54). Intraobserver agreement was almost perfect with both CTA (κ = 0.94-0.95) and MRA (κ = 0.83-0.87). The diagnostic performance of CTA and MRA for the detection of glenohumeral cartilage lesions is moderate, although statistically significantly better with CTA. (orig.)

  17. Comparison of the diagnostic performance of digital breast tomosynthesis and magnetic resonance imaging added to digital mammography in women with known breast cancers

    International Nuclear Information System (INIS)

    Kim, Won Hwa; Chang, Jung Min; Moon, Woo Kyung; Moon, Hyeong-Gon; Yi, Ann; Koo, Hye Ryoung; Gweon, Hye Mi

    2016-01-01

    To compare the diagnostic performance of digital breast tomosynthesis (DBT) and magnetic resonance imaging (MRI) added to mammography in women with known breast cancers. Three radiologists independently reviewed image sets of 172 patients with 184 cancers; mammography alone, DBT plus mammography and MRI plus mammography, and scored for cancer probability using the Breast Imaging Reporting and Data System (BI-RADS). Jack-knife alternative free-response receiver-operating characteristic (JAFROC), which allows diagnostic performance estimation using single lesion as a statistical unit in a cancer-only population, was used. Sensitivity and positive predictive value (PPV) were compared using the McNemar and Fisher-exact tests. The JAFROC figures of merit (FOMs) was lower in DBT plus mammography (0.937) than MRI plus mammography (0.978, P = 0.0006) but higher than mammography alone (0.900, P = 0.0013). The sensitivity was lower in DBT plus mammography (88.2 %) than MRI plus mammography (97.8 %) but higher than mammography alone (78.3 %, both P < 0.0001). The PPV was significantly higher in DBT plus mammography (93.3 %) than MRI plus mammography (89.6 %, P = 0.0282). DBT provided lower diagnostic performance than MRI as an adjunctive imaging to mammography. However, DBT had higher diagnostic performance than mammography and higher PPV than MRI. (orig.)

  18. Summary receiver operating characteristic curves as a technique for meta-analysis of the diagnostic performance of duplex ultrasonography in peripheral arterial disease

    NARCIS (Netherlands)

    deVries, SO; Hunink, MGM; Polak, JF

    Rationale and Objectives. We summarized and compared the diagnostic performance of duplex and color-guided duplex ultrasonography in the evaluation of peripheral arterial disease. We present our research as an example of the use of summary receiver operating characteristic (ROC) curves in a

  19. Comparison of SPECT/CT and MRI in diagnosing symptomatic lesions in ankle and foot pain patients: diagnostic performance and relation to lesion type.

    Science.gov (United States)

    Ha, Seunggyun; Hong, Sung Hwan; Paeng, Jin Chul; Lee, Dong Yeon; Cheon, Gi Jeong; Arya, Amitabh; Chung, June-Key; Lee, Dong Soo; Kang, Keon Wook

    2015-01-01

    The purpose of this study was to compare the diagnostic performance of SPECT/CT and MRI in patients with ankle and foot pain, with regard to the lesion types. Fifty consecutive patients with ankle and foot pain, who underwent 99mTc-MDP SPECT/CT and MRI, were retrospectively enrolled in this study. Symptomatic lesions were determined based on clinical examination and response to treatment. On MRI and SPECT/CT, detected lesions were classified as bone, ligament/tendon, and joint lesions. Uptake on SPECT/CT was assessed using a 4-grade system. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of SPECT/CT and MRI were evaluated in all detected lesions and each lesion type. Diagnostic value of uptake grade was analyzed using receiver-operating characteristics (ROC) curve analysis, and diagnostic performance was compared using Chi-square or McNemar tests. In overall lesions, the sensitivity, PPV and NPV of SPECT/CT for symptomatic lesions were 93%, 56%, 91%, and they were 98%, 48%, 95% for MRI. There was no significant difference between SPECT/CT and MRI. However, the specificity of SPECT/CT was significantly higher than that of MRI (48% versus 24%, P = 0.016). Uptake grade on SPECT/CT was significantly higher in symptomatic lesions (P diagnostic performance for symptomatic lesions in ankle and foot pain patients. SPECT/CT and MRI exhibit different diagnostic specificity in different lesion types. SPECT/CT may be used as a complementary imaging method to MRI for enhancing diagnostic specificity.

  20. Fiber optical sensing on-board communication satellites

    Science.gov (United States)

    Hurni, A.; Lemke, N. M. K.; Roner, M.; Obermaier, J.; Putzer, P.; Kuhenuri Chami, N.

    2017-11-01

    Striving constantly to reduce mass, AIT effort and overall cost of the classical point-to-point wired temperature sensor harness on-board telecommunication satellites, OHB System (formerly Kayser-Threde) has introduced the Hybrid Sensor Bus (HSB) system. As a future spacecraft platform element, HSB relies on electrical remote sensor units as well as fiber-optical sensors, both of which can serially be connected in a bus architecture. HSB is a modular measurement system with many applications, also thanks to the opportunities posed by the digital I²C bus. The emphasis, however, is on the introduction of fiber optics and especially fiber-Bragg grating (FBG) temperature sensors as disruptive innovation for the company's satellite platforms. The light weight FBG sensors are directly inscribed in mechanically robust and radiation tolerant fibers, reducing the need for optical fiber connectors and splices to a minimum. Wherever an FBG sensor shall be used, the fiber is glued together with a corresponding temperature transducer to the satellites structure or to a subsystem. The transducer is necessary to provide decoupling of mechanical stress, but simultaneously ensure a high thermal conductivity. HSB has been developed in the frame of an ESA-ARTES program with European and German co-funding and will be verified as flight demonstrator on-board the German Heinrich Hertz satellite (H2Sat). In this paper the Engineering Model development of HSB is presented and a Fiber-optical Sensor Multiplexer for a more flexible sensor bus architecture is introduced. The HSB system aims at telecommunication satellite platforms with an operational life time beyond 15 years in geostationary orbit. It claims a high compatibility in terms of performance and interfaces with existing platforms while it was designed with future applications with increased radiation exposure already in mind. In its basic configuration HSB consists of four modules which are the Power Supply Unit, the HSB

  1. [Qualitative and quantitative diagnostic performance of 320-slice computed tomography for detecting coronary artery disease with respect to atherosclerotic plaque characteristics].

    Science.gov (United States)

    Li, Suhua; Liu, Jinlai; Peng, Long; Dong, Ruimin; Wu, Huilan; Wang, Chenlin; Ni, Qiongqiong; Luo, Yanting; Zhu, Jieming; Chen, Lin

    2014-10-28

    To investigate qualitatively and quantitatively the diagnostic performance of 320-slice CT for detection of coronary artery disease with respect to different atherosclerotic plaque characteristics. A retrospective search was performed for inpatients underwent both coronary CT and further coronary angiography (CAG) from December 1, 2008 to December 31, 2012. The diagnostic performance of 320-slice CTA for detecting significant stenosis ( ≥ 50% diameter) with respect to atherosclerotic plaque characteristics were analyzed by calculating sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy, kappa index (κ), and area under the receiver operating characteristic curve (AUC). Chi-square test was used to evaluate whether there were significant differences of the true-case frequency (true positive + true negative) and false-case frequency (false positive + false negative) among groups. Bland-Altman analysis was used to determine limits of agreement between CTA and CAG. A total of 454 patients and 6 779 segments were analyzed. Diagnostic accuracy was higher in non-calcified segments; whereas they decreased in the presence of both mild-moderately and heavily calcified plaques. Excellent agreement (κ = 0.810) between CT and CAG was observed for non-calcified segments, while good agreement was observed for both mild-moderately (κ = 0.701) and heavily calcified segments (κ = 0.750). Both mild-moderate (P = 0.000) and heavy (P = 0.000) calcification decreased the true-case frequency and increased the false-case frequency when compared to non-calcification. There were no significant underestimation or overestimation for non-calcified (P = 0.087) and mild-moderately calcified (P = 0.704) segments, while there was significant overestimation for heavily calcified segments (P = 0.001). Great qualitative and quantitative diagnostic performances of 320-slice CT were observed in non-calcified coronary segments. However, qualitative

  2. Optical 3D scans for orthodontic diagnostics performed on full-arch impressions. Completeness of surface structure representation.

    Science.gov (United States)

    Vogel, Annike B; Kilic, Fatih; Schmidt, Falko; Rübel, Sebastian; Lapatki, Bernd G

    2015-11-01

    relatively large percentages of the total surface. However, the topographic examinations revealed that regions essential for orthodontic model analysis were missing. The malocclusion models were particularly affected. Thus, impression scans performed with structured-light scanners cannot replace scans of positive casts for diagnostic use in orthodontics.

  3. Diagnostic performance of magnetic resonance imaging and pre-surgical evaluation in the assessment of traumatic intra-articular knee disorders in children and adolescents: what conditions still pose diagnostic challenges?

    Energy Technology Data Exchange (ETDEWEB)

    Gans, Itai; Ganley, Theodore J. [The Children' s Hospital of Philadelphia, Division of Orthopaedics, 34th and Civic Center Boulevard, Philadelphia, PA (United States); Bedoya, Maria A.; Ho-Fung, Victor [The Children' s Hospital of Philadelphia, Department of Radiology, Philadelphia, PA (United States)

    2014-08-31

    Diagnosis of intra-articular lesions in children based on clinical examination and MRI is particularly challenging. To evaluate the diagnostic performance of MRI and pre-surgical evaluation of the knee in pediatric patients relative to arthroscopic evaluation as the gold standard. We report diagnoses frequently missed or inaccurately diagnosed pre-operatively. We conducted a retrospective review of MRI and pre-surgical evaluation in children and adolescents ages 1-17 years who were treated by knee arthroscopy during a 21/2-year period. All MRIs were reviewed by a pediatric radiologist blinded to clinical findings. Pediatric orthopedic clinic notes were reviewed for pre-surgical evaluation (based on physical exam, radiograph, MR images and radiologist's MRI report). Arthroscopic findings were used as the gold standard. We calculated the percentages of diagnoses at arthroscopy missed on both MRI and pre-surgical evaluation. Diagnostic accuracy between children and adolescents and in patients with one pathological lesion vs. those with >1 lesion was analyzed. We performed a second review of MR images of the missed or over-called MRI diagnoses with knowledge of arthroscopic findings. We included 178 children and adolescents. The most common diagnoses missed on MRI or pre-surgical evaluation but found at arthroscopy were: discoid meniscus (8/30, or 26.7% of cases); lateral meniscal tears (15/80, or 18.8% of cases); intra-articular loose bodies (5/36, or 13.9% of cases), and osteochondral injuries (9/73, or 12.3% of cases). Overall diagnostic accuracy of MRI and pre-surgical evaluation was 92.7% and 95.3%, respectively. No significant difference in diagnostic accuracy between children and adolescents was observed. When multiple intra-articular lesions were present, lateral meniscal tears were more likely to be inaccurately diagnosed (missed or over-called) on both MRI (P = 0.009) and pre-surgical evaluation (P < 0.001). Overall diagnostic accuracy of MRI and pre

  4. Diagnostic performance of magnetic resonance imaging and pre-surgical evaluation in the assessment of traumatic intra-articular knee disorders in children and adolescents: what conditions still pose diagnostic challenges?

    International Nuclear Information System (INIS)

    Gans, Itai; Ganley, Theodore J.; Bedoya, Maria A.; Ho-Fung, Victor

    2015-01-01

    Diagnosis of intra-articular lesions in children based on clinical examination and MRI is particularly challenging. To evaluate the diagnostic performance of MRI and pre-surgical evaluation of the knee in pediatric patients relative to arthroscopic evaluation as the gold standard. We report diagnoses frequently missed or inaccurately diagnosed pre-operatively. We conducted a retrospective review of MRI and pre-surgical evaluation in children and adolescents ages 1-17 years who were treated by knee arthroscopy during a 21/2-year period. All MRIs were reviewed by a pediatric radiologist blinded to clinical findings. Pediatric orthopedic clinic notes were reviewed for pre-surgical evaluation (based on physical exam, radiograph, MR images and radiologist's MRI report). Arthroscopic findings were used as the gold standard. We calculated the percentages of diagnoses at arthroscopy missed on both MRI and pre-surgical evaluation. Diagnostic accuracy between children and adolescents and in patients with one pathological lesion vs. those with >1 lesion was analyzed. We performed a second review of MR images of the missed or over-called MRI diagnoses with knowledge of arthroscopic findings. We included 178 children and adolescents. The most common diagnoses missed on MRI or pre-surgical evaluation but found at arthroscopy were: discoid meniscus (8/30, or 26.7% of cases); lateral meniscal tears (15/80, or 18.8% of cases); intra-articular loose bodies (5/36, or 13.9% of cases), and osteochondral injuries (9/73, or 12.3% of cases). Overall diagnostic accuracy of MRI and pre-surgical evaluation was 92.7% and 95.3%, respectively. No significant difference in diagnostic accuracy between children and adolescents was observed. When multiple intra-articular lesions were present, lateral meniscal tears were more likely to be inaccurately diagnosed (missed or over-called) on both MRI (P = 0.009) and pre-surgical evaluation (P < 0.001). Overall diagnostic accuracy of MRI and pre

  5. Diagnostic Performance of F-18 FDG PET/CT in Patients with Cancer of Unknown Primary: Additional Benefit over CT-Based Conventional Work up

    Directory of Open Access Journals (Sweden)

    Mehrdad Bakhshayeshkaram

    2016-01-01

    Full Text Available Background: In the era of well-developed site-specific treatment strategies in cancer, identification of occult primary is of paramount importance in CUP patients. Furthermore, exact determination of the extent of the disease may help in optimizing treatment planning. The aim of the present study was to investigate additional value of F-18 FDG PET/CT in patients with cancer of unknown primary (CUP as an appropriate imaging tool in early phase of initial standard work up.Materials and Methods: Sixty-two newly diagnosed CUP patients with inconclusive diagnostic CT scan of chest, abdomen and pelvis referring for F-18 FDG PET/CT were enrolled in this study. Standard of reference was defined as histopathology, other diagnostic procedures and a 3-month formal clinical follow up. The results of PET/CT were categorized as suggestion for primary site and additional metastasis and classified as true positive, false positive, false negative and true negative. The impact of additional metastasis revealed by F-18 FDG PET/CT on treatment planning and the time contribution of F-18 FDG PET/CT in diagnostic pathway was investigated.Results: Sixty-two patients with mean age of 62 (30 men, 32 women, PET/CT correctly identified primary origin in 32% with false positive rate of 14.8%. No primary lesion was detected after negative PET/CT according to standard of reference. Sensitivity, Specificity and accuracy were 100%, 78% and 85%, respectively. Additional metastatic site was found in 56% with 22% impact on treatment planning. Time contribution for PET/CT was 10% of total diagnostic pathway.Conclusion: Providing higher detection rate of primary origin with excellent diagnostic performance, shortening the diagnostic pathway and improving treatment planning, F-18 FDG PET/CT may play a major role in diagnostic work up of CUP patients and may be recommended as an alternative imaging tool in early phase of investigation.

  6. Diagnostic Performance of Fluorine-18-Fluorodeoxyglucose Positron Emission Tomography in the Postchemotherapy Management of Patients with Seminoma: Systematic Review and Meta-Analysis

    OpenAIRE

    Giorgio Treglia; Ramin Sadeghi; Salvatore Annunziata; Carmelo Caldarella; Francesco Bertagna; Luca Giovanella

    2014-01-01

    Objective. To meta-analyze published data about the diagnostic performance of fluorine-18-Fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) and PET/computed tomography (PET/CT) in the postchemotherapy management of patients with seminoma. Methods. A comprehensive literature search of studies published through January 2014 on this topic was performed. All retrieved studies were reviewed and qualitatively analyzed. Pooled sensitivity and specificity, positive and negative predicti...

  7. SuperAGILE onboard electronics and ground test instrumentation

    International Nuclear Information System (INIS)

    Pacciani, Luigi; Morelli, Ennio; Rubini, Alda; Mastropietro, Marcello; Porrovecchio, Geiland; Costa, Enrico; Del Monte, Ettore; Donnarumma, Immacolata; Evangelista, Yuri; Feroci, Marco; Lazzarotto, Francesco; Rapisarda, Massimo; Soffitta, Paolo

    2007-01-01

    In this paper we describe the electronics of the SuperAGILE X-ray imager on-board AGILE satellite and the instrumentation developed to test and improve the Front-End and digital electronics of the flight model of the imager. Although the working principle of the instrument is very well established, and the conceptual scheme simple, the budget and mechanical constraints of the AGILE small mission made necessary the introduction of new elements in SuperAGILE, regarding both the mechanics and the electronics. In fact the instrument is contained in a ∼44x44x16cm 3 volume, but the required performance is quite ambitious, leading us to equip a sensitive area of ∼1350cm 2 with 6144 Silicon μstrips detectors with a pitch of 121μm and a total length of ∼18.2cm. The result is a very light and power-cheap imager with a good sensitivity (∼15mCrab in 1 day in 15-45keV), high angular resolution (6arcmin) and gross spectral resolution. The test-equipment is versatile, and can be easily modified to test FEE based on self-triggered, data-driven and sparse-readout ASICs such as XA family chips

  8. Cosmic radiation dosimetry onboard aircrafts at the brazilian airspace

    International Nuclear Information System (INIS)

    Federico, Claudio Antonio

    2011-01-01

    The objective of this work is the establishment of a dosimetric system for the aircrew in the domestic territory. A technique to perform measurements of ambient dose equivalent in aircrafts was developed. An active detector was evaluated for onboard aircraft use, testing its adequacy to this specific type of measurement as well as its susceptibility to the magnetic and electromagnetic interferences. The equipment was calibrated in standard radiation beams and in a special field of the European Laboratory CERN, that reproduces with great proximity the real spectrum in aircraft flight altitudes; it was also tested in several flights, in an Brazilian Air Force's aircraft. The results were evaluated and compared with those obtained from several computational programs for cosmic radiation estimates, with respect to its adequacy for use in the South American region. The program CARI-6 was selected to evaluate the estimated averaged effective doses for the aircrew who operate in this region. A statistical distribution of aircrew effective doses in South America and Caribe was made, and the results show that a great part of this aircrew members are subjected to annual effective doses that exceed the dose limits for the members of the public. Additionally, a preliminary passive dosemeter, based in thermoluminescent detectors, was proposed; international collaborations with United Kingdom and Italy were established for joint measurements of the ambient equivalent doses in aircrafts. (author)

  9. Experiment in Onboard Synthetic Aperture Radar Data Processing

    Science.gov (United States)

    Holland, Matthew

    2011-01-01

    Single event upsets (SEUs) are a threat to any computing system running on hardware that has not been physically radiation hardened. In addition to mandating the use of performance-limited, hardened heritage equipment, prior techniques for dealing with the SEU problem often involved hardware-based error detection and correction (EDAC). With limited computing resources, software- based EDAC, or any more elaborate recovery methods, were often not feasible. Synthetic aperture radars (SARs), when operated in the space environment, are interesting due to their relevance to NASAs objectives, but problematic in the sense of producing prodigious amounts of raw data. Prior implementations of the SAR data processing algorithm have been too slow, too computationally intensive, and require too much application memory for onboard execution to be a realistic option when using the type of heritage processing technology described above. This standard C-language implementation of SAR data processing is distributed over many cores of a Tilera Multicore Processor, and employs novel Radiation Hardening by Software (RHBS) techniques designed to protect the component processes (one per core) and their shared application memory from the sort of SEUs expected in the space environment. The source code includes calls to Tilera APIs, and a specialized Tilera compiler is required to produce a Tilera executable. The compiled application reads input data describing the position and orientation of a radar platform, as well as its radar-burst data, over time and writes out processed data in a form that is useful for analysis of the radar observations.

  10. Diagnostic performance of contrast-enhanced MR for acute appendicitis and alternative causes of abdominal pain in children

    Energy Technology Data Exchange (ETDEWEB)

    Koning, Jeffrey L. [University of California San Diego, Department of Radiology, San Diego, CA (United States); Naheedy, John H.; Kruk, Peter G. [University of California San Diego, Department of Radiology, San Diego, CA (United States); Rady Children' s Hospital, Department of Radiology, San Diego, CA (United States)

    2014-08-15

    Unenhanced MRI has emerged as a useful tool for diagnosing pediatric acute appendicitis. The use of contrast-enhanced MRI for diagnosing pediatric appendicitis has not been documented. The purpose of this study is to examine the diagnostic performance of contrast-enhanced MRI for acute appendicitis and alternative entities in the pediatric population presenting with acute abdominal pain. A retrospective review was conducted of 364 consecutive pediatric patients undergoing contrast-enhanced MRI for the evaluation of possible appendicitis at a single institution between November 2012 and September 2013. There were 132 cases of pathologically confirmed appendicitis out of 364 pediatric patients (36.3%) included in the study. Overall sensitivity and specificity were 96.2% (95% CI [91.4-98.4%]) and 95.7% (95% CI [92.3-97.6%]), respectively. Positive predictive value and negative predictive value were 92.7% (95% CI [86.6-96.3%]) and 97.8% (95% CI [94.7-99.1%]), respectively. The appendix was visualized in 243 cases (66.8%). Imaging confirmed alternative diagnoses in 75 patients, including most commonly colitis, enteritis or terminal ileitis (n = 25, 6.9%), adnexal cysts (n = 25, 6.9%) and mesenteric adenitis (n = 7, 1.9%). Contrast-enhanced MRI is capable of accurately diagnosing acute appendicitis while detecting many alternative entities of abdominal pain, and it allows good visualization of the appendix. Further evaluation is needed to determine whether contrast-enhanced MRI provides an advantage over non-enhanced MRI for imaging evaluation of acute abdominal pain in the pediatric population. (orig.)

  11. Diagnostic performance of contrast-enhanced MR for acute appendicitis and alternative causes of abdominal pain in children

    International Nuclear Information System (INIS)

    Koning, Jeffrey L.; Naheedy, John H.; Kruk, Peter G.

    2014-01-01

    Unenhanced MRI has emerged as a useful tool for diagnosing pediatric acute appendicitis. The use of contrast-enhanced MRI for diagnosing pediatric appendicitis has not been documented. The purpose of this study is to examine the diagnostic performance of contrast-enhanced MRI for acute appendicitis and alternative entities in the pediatric population presenting with acute abdominal pain. A retrospective review was conducted of 364 consecutive pediatric patients undergoing contrast-enhanced MRI for the evaluation of possible appendicitis at a single institution between November 2012 and September 2013. There were 132 cases of pathologically confirmed appendicitis out of 364 pediatric patients (36.3%) included in the study. Overall sensitivity and specificity were 96.2% (95% CI [91.4-98.4%]) and 95.7% (95% CI [92.3-97.6%]), respectively. Positive predictive value and negative predictive value were 92.7% (95% CI [86.6-96.3%]) and 97.8% (95% CI [94.7-99.1%]), respectively. The appendix was visualized in 243 cases (66.8%). Imaging confirmed alternative diagnoses in 75 patients, including most commonly colitis, enteritis or terminal ileitis (n = 25, 6.9%), adnexal cysts (n = 25, 6.9%) and mesenteric adenitis (n = 7, 1.9%). Contrast-enhanced MRI is capable of accurately diagnosing acute appendicitis while detecting many alternative entities of abdominal pain, and it allows good visualization of the appendix. Further evaluation is needed to determine whether contrast-enhanced MRI provides an advantage over non-enhanced MRI for imaging evaluation of acute abdominal pain in the pediatric population. (orig.)

  12. Deployment and future prospects of high performance diagnostics featuring serial I/O (SIO) data acquisition (DAQ) at ASDEX Upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Behler, K., E-mail: karl.behler@ipp.mpg.de [Max-Planck-Institut fuer Plasmaphysik, Boltzmannstr. 2, D-85748 Garching bei Muenchen (Germany); Blank, H.; Eixenberger, H. [Max-Planck-Institut fuer Plasmaphysik, Boltzmannstr. 2, D-85748 Garching bei Muenchen (Germany); Fitzek, M. [Unlimited Computer Systems GmbH, Seeshaupterstr. 15, D-82393 Iffeldorf (Germany); Lohs, A. [Max-Planck-Institut fuer Plasmaphysik, Boltzmannstr. 2, D-85748 Garching bei Muenchen (Germany); Lueddecke, K. [Unlimited Computer Systems GmbH, Seeshaupterstr. 15, D-82393 Iffeldorf (Germany); Merkel, R. [Max-Planck-Institut fuer Plasmaphysik, Boltzmannstr. 2, D-85748 Garching bei Muenchen (Germany)

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer The high sustained data rates transferring measured data from periphery into memory of computers. Black-Right-Pointing-Pointer The achieved low latency in real-time interrupt handling under Solaris 10. Black-Right-Pointing-Pointer The new prototype of an even more powerful 2nd generation SIO II device. Black-Right-Pointing-Pointer The fusion of all blocks of board logic (serializer, FIFO, TDC, merge engine, PCIe controller) into one single FPGA simplifying the boards physical layout significantly. - Abstract: The SIO DAQ concept used at the ASDEX Upgrade fusion experiment features data acquisition from a modular front-end (a modular crate-and-interface-cards concept for analog and digital input and output) over standardized serial lines and via a serial input/output computer interface card (the SIO card) in real-time directly into the main memory of a host computer. Deployment of a series of diagnostics using SIO led to various solutions and configurations for the different requirements. Experience has been gained and lessons learned applying the SIO concept at its technical limits. Requirements for a further development of the SIO concept have been identified, and a performance improvement by a factor of 4-8 beyond its current limits seems achievable. An effort has been started to develop a SIO version 2 (SIO II) featuring upgraded serial links and a more powerful FPGA for merging and forwarding data streams to host computer memory. (Compatibility with the existing SIO (SIO I) front-end system has to be maintained.) This paper presents results achieved and experiences gained in the deployment of SIO I, the status of SIO II development (currently in the prototype phase), and projected enhancements and updates to existing implementations.

  13. The diagnostic performance of magnetic resonance spectroscopy in differentiating high-from low-grade gliomas: A systematic review and meta-analysis

    International Nuclear Information System (INIS)

    Wang, Qun; Zhang, JiaShu; Wu, Chen; Li, FangYe; Chen, XiaoLei; Xu, BaiNan; Zhang, Hui; Zhu, WeiJie

    2016-01-01

    Magnetic resonance spectroscopy (MRS) is a powerful tool for preoperative grading of gliomas. We performed a meta-analysis to evaluate the diagnostic performance of MRS in differentiating high-grade gliomas (HGGs) from low-grade gliomas (LGGs). PubMed and Embase databases were systematically searched for relevant studies of glioma grading assessed by MRS through 27 March 2015. Based on the data from eligible studies, pooled sensitivity, specificity, diagnostic odds ratio and areas under summary receiver operating characteristic curve (SROC) of different metabolite ratios were obtained. Thirty articles comprising a total sample size of 1228 patients were included in our meta-analysis. Quantitative synthesis of studies showed that the pooled sensitivity/specificity of Cho/Cr, Cho/NAA and NAA/Cr ratios was 0.75/0.60, 0.80/0.76 and 0.71/0.70, respectively. The area under the curve (AUC) of the SROC was 0.83, 0.87 and 0.78, respectively. MRS demonstrated moderate diagnostic performance in distinguishing HGGs from LGGs using tumoural metabolite ratios including Cho/Cr, Cho/NAA and NAA/Cr. Although there was no significant difference in AUC between Cho/Cr and Cho/NAA groups, Cho/NAA ratio showed higher sensitivity and specificity than Cho/Cr ratio and NAA/Cr ratio. We suggest that MRS should combine other advanced imaging techniques to improve diagnostic accuracy in differentiating HGGs from LGGs. (orig.)

  14. Combined diagnostic performance of coronary computed tomography angiography and computed tomography derived fractional flow reserve for the evaluation of myocardial ischemia: A meta-analysis.

    Science.gov (United States)

    Tan, Xiao Wei; Zheng, Qishi; Shi, Luming; Gao, Fei; Allen, John Carson; Coenen, Adriaan; Baumann, Stefan; Schoepf, U Joseph; Kassab, Ghassan S; Lim, Soo Teik; Wong, Aaron Sung Lung; Tan, Jack Wei Chieh; Yeo, Khung Keong; Chin, Chee Tang; Ho, Kay Woon; Tan, Swee Yaw; Chua, Terrance Siang Jin; Chan, Edwin Shih Yen; Tan, Ru San; Zhong, Liang

    2017-06-01

    To evaluate the combined diagnostic accuracy of coronary computed tomography angiography (CCTA) and computed tomography derived fractional flow reserve (FFRct) in patients with suspected or known coronary artery disease (CAD). PubMed, The Cochrane library, Embase and OpenGray were searched to identify studies comparing diagnostic accuracy of CCTA and FFRct. Diagnostic test measurements of FFRct were either extracted directly from the published papers or calculated from provided information. Bivariate models were conducted to synthesize the diagnostic performance of combined CCTA and FFRct at both "per-vessel" and "per-patient" levels. 7 articles were included for analysis. The combined diagnostic outcomes from "both positive" strategy, i.e. a subject was considered as "positive" only when both CCTA and FFRct were "positive", demonstrated relative high specificity (per-vessel: 0.91; per-patient: 0.81), high positive likelihood ratio (LR+, per-vessel: 7.93; per-patient: 4.26), high negative likelihood ratio (LR-, per-vessel: 0.30; per patient: 0.24) and high accuracy (per-vessel: 0.91; per-patient: 0.81) while "either positive" strategy, i.e. a subject was considered as "positive" when either CCTA or FFRct was "positive", demonstrated relative high sensitivity (per-vessel: 0.97; per-patient: 0.98), low LR+ (per-vessel: 1.50; per-patient: 1.17), low LR- (per-vessel: 0.07; per-patient: 0.09) and low accuracy (per-vessel: 0.57; per-patient: 0.54). "Both positive" strategy showed better diagnostic performance to rule in patients with non-significant stenosis compared to "either positive" strategy, as it efficiently reduces the proportion of testing false positive subjects. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Performance of in silico prediction tools for the classification of rare BRCA1/2 missense variants in clinical diagnostics.

    Science.gov (United States)

    Ernst, Corinna; Hahnen, Eric; Engel, Christoph; Nothnagel, Michael; Weber, Jonas; Schmutzler, Rita K; Hauke, Jan

    2018-03-27

    The use of next-generation sequencing approaches in clinical diagnostics has led to a tremendous increase in data and a vast number of variants of uncertain significance that require interpretation. Therefore, prediction of the effects of missense mutations using in silico tools has become a frequently used approach. Aim of this study was to assess the reliability of in silico prediction as a basis for clinical decision making in the context of hereditary breast and/or ovarian cancer. We tested the performance of four prediction tools (Align-GVGD, SIFT, PolyPhen-2, MutationTaster2) using a set of 236 BRCA1/2 missense variants that had previously been classified by expert committees. However, a major pitfall in the creation of a reliable evaluation set for our purpose is the generally accepted classification of BRCA1/2 missense variants using the multifactorial likelihood model, which is partially based on Align-GVGD results. To overcome this drawback we identified 161 variants whose classification is independent of any previous in silico prediction. In addition to the performance as stand-alone tools we examined the sensitivity, specificity, accuracy and Matthews correlation coefficient (MCC) of combined approaches. PolyPhen-2 achieved the lowest sensitivity (0.67), specificity (0.67), accuracy (0.67) and MCC (0.39). Align-GVGD achieved the highest values of specificity (0.92), accuracy (0.92) and MCC (0.73), but was outperformed regarding its sensitivity (0.90) by SIFT (1.00) and MutationTaster2 (1.00). All tools suffered from poor specificities, resulting in an unacceptable proportion of false positive results in a clinical setting. This shortcoming could not be bypassed by combination of these tools. In the best case scenario, 138 families would be affected by the misclassification of neutral variants within the cohort of patients of the German Consortium for Hereditary Breast and Ovarian Cancer. We show that due to low specificities state-of-the-art in silico

  16. Impact of helminth diagnostic test performance on estimation of risk factors and outcomes in HIV-positive adults.

    Directory of Open Access Journals (Sweden)

    Michael B Arndt

    Full Text Available BACKGROUND: Traditional methods using microscopy for the detection of helminth infections have limited sensitivity. Polymerase chain reaction (PCR assays enhance detection of helminths, particularly low burden infections. However, differences in test performance may modify the ability to detect associations between helminth infection, risk factors, and sequelae. We compared these associations using microscopy and PCR. METHODS: This cross-sectional study was nested within a randomized clinical trial conducted at 3 sites in Kenya. We performed microscopy and real-time multiplex PCR for the stool detection and quantification of Ascaris lumbricoides, Necator americanus, Ancylostoma duodenale, Strongyloides stercoralis, and Schistosoma species. We utilized regression to evaluate associations between potential risk factors or outcomes and infection as detected by either method. RESULTS: Of 153 HIV-positive adults surveyed, 55(36.0% and 20(13.1% were positive for one or more helminth species by PCR and microscopy, respectively (p<0.001. PCR-detected infections were associated with farming (Prevalence Ratio 1.57, 95% CI: 1.02, 2.40, communal water source (PR 3.80, 95% CI: 1.01, 14.27, and no primary education (PR 1.54, 95% CI: 1.14, 2.33, whereas microscopy-detected infections were not associated with any risk factors under investigation. Microscopy-detected infections were associated with significantly lower hematocrit and hemoglobin (means of -3.56% and -0.77 g/dl and a 48% higher risk of anemia (PR 1.48, 95% CI: 1.17, 1.88 compared to uninfected. Such associations were absent for PCR-detected infections unless infection intensity was considered, Infections diagnosed with either method were associated with increased risk of eosinophilia (PCR PR 2.42, 95% CI: 1.02, 5.76; microscopy PR 2.92, 95% CI: 1.29, 6.60. CONCLUSION: Newer diagnostic methods, including PCR, improve the detection of helminth infections. This heightened sensitivity may improve the

  17. Satellite on-board real-time SAR processor prototype

    Science.gov (United States)

    Bergeron, Alain; Doucet, Michel; Harnisch, Bernd; Suess, Martin; Marchese, Linda; Bourqui, Pascal; Desnoyers, Nicholas; Legros, Mathieu; Guillot, Ludovic; Mercier, Luc; Châteauneuf, François

    2017-11-01

    A Compact Real-Time Optronic SAR Processor has been successfully developed and tested up to a Technology Readiness Level of 4 (TRL4), the breadboard validation in a laboratory environment. SAR, or Synthetic Aperture Radar, is an active system allowing day and night imaging independent of the cloud coverage of the planet. The SAR raw data is a set of complex data for range and azimuth, which cannot be compressed. Specifically, for planetary missions and unmanned aerial vehicle (UAV) systems with limited communication data rates this is a clear disadvantage. SAR images are typically processed electronically applying dedicated Fourier transformations. This, however, can also be performed optically in real-time. Originally the first SAR images were optically processed. The optical Fourier processor architecture provides inherent parallel computing capabilities allowing real-time SAR data processing and thus the ability for compression and strongly reduced communication bandwidth requirements for the satellite. SAR signal return data are in general complex data. Both amplitude and phase must be combined optically in the SAR processor for each range and azimuth pixel. Amplitude and phase are generated by dedicated spatial light modulators and superimposed by an optical relay set-up. The spatial light modulators display the full complex raw data information over a two-dimensional format, one for the azimuth and one for the range. Since the entire signal history is displayed at once, the processor operates in parallel yielding real-time performances, i.e. without resulting bottleneck. Processing of both azimuth and range information is performed in a single pass. This paper focuses on the onboard capabilities of the compact optical SAR processor prototype that allows in-orbit processing of SAR images. Examples of processed ENVISAT ASAR images are presented. Various SAR processor parameters such as processing capabilities, image quality (point target analysis), weight and

  18. Comparison of the Diagnostic Performance of Power Doppler Ultrasound and a New Microvascular Doppler Ultrasound Technique (AngioPLUS) for Differentiating Benign and Malignant Breast Masses.

    Science.gov (United States)

    Jung, Hae Kyoung; Park, Ah Young; Ko, Kyung Hee; Koh, Jieun

    2018-03-12

    This study was performed to compare the diagnostic performance of power Doppler ultrasound (US) and a new microvascular Doppler US technique (AngioPLUS; SuperSonic Imagine, Aix-en-Provence, France) for differentiating benign and malignant breast masses. Power Doppler US and AngioPLUS findings were available in 124 breast masses with confirmed pathologic results (benign, 80 [64.5%]; malignant, 44 [35.5%]). The diagnostic performance of each tool was calculated to distinguish benign from malignant masses using a receiver operating characteristic curve analysis and compared. The area under the curve showed that AngioPLUS was superior to power Doppler US in differentiating benign from malignant breast masses, but the difference was not statistically significant. © 2018 by the American Institute of Ultrasound in Medicine.

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

    International Nuclear Information System (INIS)

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

    2014-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Bowsher, James, E-mail: james.bowsher@duke.edu; Giles, William; Yin, Fang-Fang [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina 27710 and Medical Physics Graduate Program, Duke University, Durham, North Carolina 27710 (United States); Yan, Susu [Medical Physics Graduate Program, Duke University, Durham, North Carolina 27710 (United States); Roper, Justin [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina 27710 (United States)

    2014-01-15

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

  1. Spaceflight Systems Training: A Comparison and Contrasting of Techniques for Training Ground Operators and Onboard Crewmembers

    Science.gov (United States)

    Balmain, Clinton; Fleming, Mark

    2009-01-01

    When developing techniques and products for instruction on manned spaceflight systems, training organizations are often faced with two very different customers: ground operators and onboard crewmembers. Frequently, instructional development focuses on one of these customers with the assumption that the other s needs will be met by default. Experience teaches us that differing approaches are required when developing training tailored to the specific needs of each customer. As a rule, ground operators require focused instruction on specific areas of expertise. Their knowledge should be of the details of the hardware, software, and operational techniques associated with that system. They often benefit from historical knowledge of how their system has operated over its lifetime. Since several different ground operators may be interfacing with the same system, each individual operator must understand the agreed-to principles by which that system will be run. In contrast, onboard crewmembers require a more broad, hands-on awareness of their operational environment. Their training should be developed with an understanding of the physical environment in which they live and work and the day-to-day tasks they are most likely to perform. Rarely do they require a deep understanding of the details of a system; it is often sufficient to teach them just enough to maintain situational awareness and perform basic tasks associated with maintenance and operation of onboard systems. Crewmembers may also develop unique onboard operational techniques that differ from preceding crews. They should be taught what flexibility they have in systems operations and how their specific habits can be communicated to ground support personnel. This paper will explore the techniques that can be employed when developing training for these unique customers. We will explore the history of International Space Station training development and how past efforts can guide us in creating training for users of

  2. A Study on Remote On-Line Diagnostic System for Vehicles by Integrating the Technology of OBD, GPS, and 3G

    OpenAIRE

    Jyong Lin; Shih-Chang Chen; Yu-Tsen Shih; Shi-Huang Chen

    2009-01-01

    This paper presents a remote on-line diagnostic system for vehicles via the use of On-Board Diagnostic (OBD), GPS, and 3G techniques. The main parts of the proposed system are on-board computer, vehicle monitor server, and vehicle status browser. First, the on-board computer can obtain the location of deriver and vehicle status from GPS receiver and OBD interface, respectively. Then on-board computer will connect with the vehicle monitor server through 3G network to trans...

  3. Comparison of diagnostic performance between single- and multiphasic contrast-enhanced abdominopelvic computed tomography in patients admitted to the emergency department with abdominal pain: potential radiation dose reduction

    International Nuclear Information System (INIS)

    Hwang, Shin Hye; You, Je Sung; Choi, Jin-Young; Kim, Myeong-Jin; Chung, Yong Eun; Song, Mi Kyong

    2015-01-01

    To evaluate feasibility of radiation dose reduction by optimal phase selection of computed tomography (CT) in patients who visited the emergency department (ED) for abdominal pain. We included 253 patients who visited the ED for abdominal pain. They underwent multiphasic CT including precontrast, late arterial phase (LAP), and hepatic venous phase (HVP). Three image sets (HVP, precontrast + HVP, and precontrast + LAP + HVP) were reviewed. Two reviewers determined the most appropriate diagnosis with five-point confidence scale. Diagnostic performances were compared among image sets by weighted-least-squares method or DeLong's method. Linear mixed model was used to assess changes of diagnostic confidence and radiation dose. There was no difference in diagnostic performance among three image sets, although diagnostic confidence level was significantly improved after review of triphasic images compared with both HVP images only or HVP with precontrast images (confidence scale, 4.64 ± 0.05, 4.66 ± 0.05, and 4.76 ± 0.04 in the order of the sets; overall P = 0.0008). Similar trends were observed in the subgroup analysis for diagnosis of pelvic inflammatory disease and cholecystitis. There is no difference between HVP-CT alone and multiphasic CT for the diagnosis of causes of abdominal pain in patients admitted to the ED without prior chronic disease or neoplasia. (orig.)

  4. Comparison of diagnostic performance between single- and multiphasic contrast-enhanced abdominopelvic computed tomography in patients admitted to the emergency department with abdominal pain: potential radiation dose reduction

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Shin Hye; You, Je Sung; Choi, Jin-Young; Kim, Myeong-Jin; Chung, Yong Eun [Yonsei University College of Medicine, Department of Radiology, Research Institute of Radiological Science, Seodaemun-gu, Seoul (Korea, Republic of); Song, Mi Kyong [Yonsei University, Biostatistics Collaboration Unit, College of Medicine, Seoul (Korea, Republic of)

    2015-04-01

    To evaluate feasibility of radiation dose reduction by optimal phase selection of computed tomography (CT) in patients who visited the emergency department (ED) for abdominal pain. We included 253 patients who visited the ED for abdominal pain. They underwent multiphasic CT including precontrast, late arterial phase (LAP), and hepatic venous phase (HVP). Three image sets (HVP, precontrast + HVP, and precontrast + LAP + HVP) were reviewed. Two reviewers determined the most appropriate diagnosis with five-point confidence scale. Diagnostic performances were compared among image sets by weighted-least-squares method or DeLong's method. Linear mixed model was used to assess changes of diagnostic confidence and radiation dose. There was no difference in diagnostic performance among three image sets, although diagnostic confidence level was significantly improved after review of triphasic images compared with both HVP images only or HVP with precontrast images (confidence scale, 4.64 ± 0.05, 4.66 ± 0.05, and 4.76 ± 0.04 in the order of the sets; overall P = 0.0008). Similar trends were observed in the subgroup analysis for diagnosis of pelvic inflammatory disease and cholecystitis. There is no difference between HVP-CT alone and multiphasic CT for the diagnosis of causes of abdominal pain in patients admitted to the ED without prior chronic disease or neoplasia. (orig.)

  5. Antibodies to phosphatidylserine/prothrombin (aPS/PT) enhanced the diagnostic performance in Chinese patients with antiphospholipid syndrome.

    Science.gov (United States)

    Zhang, Shulan; Wu, Ziyan; Zhang, Wen; Zhao, Jiuliang; Norman, Gary L; Zeng, Xiaofeng; Zhang, Fengchun; Li, Yongzhe

    2018-03-21

    Increasing evidence has highlighted the role of non-criteria antiphospholipid antibodies (aPLs) as important supplements to the current criteria aPLs for the diagnosis of antiphospholipid syndrome (APS). In this retrospective study, we evaluated the clinical relevance of antibodies to phosphatidylserine/prothrombin (aPS/PT) in Chinese patients with APS. A total of 441 subjects were tested, including 101 patients with primary APS (PAPS), 140 patients with secondary APS (SAPS), 161 disease controls (DCs) and 39 healthy controls (HCs). Serum IgG/IgM aPS/PT was determined by ELISA. The levels of IgG/IgM aPS/PT were significantly increased in patients with APS compared with DCs and HCs. IgG and IgM aPS/PT were present in 29.7% and 54.5% of PAPS, and 42.1% and 53.6% of SAPS, respectively. For diagnosis of APS, IgG aCL exhibited the highest positive likelihood ratio (LR+) of 21.60, followed by LA (13.84), IgG aβ2GP1 (9.19) and IgG aPS/PT (8.49). aPS/PT was detected in 13.3% of seronegative PAPS patients and 31.3% of seronegative SAPS patients. LA exhibited the highest OR of 3.64 in identifying patients with thrombosis, followed by IgG aCL (OR, 2.63), IgG aPS/PT (OR, 2.55) and IgG aβ2GP1 (OR, 2.33). LA and IgG aCL were correlated with both arterial and venous thrombosis, whereas IgG aPS/PT and IgG aβ2GP1 correlated with venous or arterial thrombosis, respectively. Our findings suggest that the inclusion of IgG/IgM aPS/PT may enhance the diagnostic performance for APS, especially in those in whom APS is highly suspected, but conventional aPLs are repeatedly negative. In addition, IgG aPS/PT may contribute to identify patients at risk of thrombosis.

  6. Diagnostic performance of diffusion-weighted MR imaging in differentiation of diabetic osteoarthropathy and osteomyelitis in diabetic foot

    International Nuclear Information System (INIS)

    Abdel Razek, Ahmed Abdel Khalek; Samir, Sieza

    2017-01-01

    Highlights: • Excellent inter-observer agreement of ADC of bony lesions in diabetic foot. • ADC can differentiate diabetic osteoarthropathy from osteomylitis. • Diffusion MR imaging can added to routine MR imaging of diabetic foot. - Abstract: Purpose: To study the diagnostic performance of diffusion weighted MR imaging in differentiation of diabetic osteoarthropathy and osteomyelitis in diabetic foot. Patients and methods: This prospective study was carried out on 41 patients with diabetic foot, 22 males and 19 females with mean age of 51 years. They underwent diffusion-weighted MR imaging of the foot. The apparent diffusion coefficient (ADC) values of the bony lesions were calculated by two reviewers and correlated with the surgical findings or biopsy. The kappa statistic (k) was used to estimate the proportion of inter-observer agreement of two reviewers. Results: The mean ADC of acute diabetic osteoarthropathy was 1.27 ± 0.19 × 10 −3 mm 2 /s for reviewer 1 and 1.26 ± 0.21 × 10 −3 mm 2 /s for reviewer 2. The mean ADC value in diabetic osteomyelitis was 0.86 ± 0.11 × 10 −3 mm 2 /s for reviewer 1 and 0.85 ± 0.12 × 10 −3 mm 2 /s for reviewer 2. There was excellent inter-observer agreement of ADC value of bony lesions in diabetic foot by both reviewers (K = 0.93). There was statistically significant difference in the ADC values of both groups (P = 0.001). The cut-off point of ADC value of both reviewers used in differentiating acute diabetic osteoarthropathy and osteomyelitis were 0.98 × 10 −3 mm 2 /s and 1.04 × 10 −3 mm 2 /s with an accuracy of 94% and 93% and area under the curve of 0.94 and 0.93 respectively. Conclusion: We conclude that the ADC value is a non-invasive imaging parameter that can help in differentiation of diabetic osteoarthropathy from osteomyelitis with excellent inter-observer agreement.

  7. Diagnostic performance of diffusion-weighted MR imaging in differentiation of diabetic osteoarthropathy and osteomyelitis in diabetic foot

    Energy Technology Data Exchange (ETDEWEB)

    Abdel Razek, Ahmed Abdel Khalek, E-mail: arazek@mans.edu.eg; Samir, Sieza, E-mail: Sieza_s@mans.edu.eg

    2017-04-15

    Highlights: • Excellent inter-observer agreement of ADC of bony lesions in diabetic foot. • ADC can differentiate diabetic osteoarthropathy from osteomylitis. • Diffusion MR imaging can added to routine MR imaging of diabetic foot. - Abstract: Purpose: To study the diagnostic performance of diffusion weighted MR imaging in differentiation of diabetic osteoarthropathy and osteomyelitis in diabetic foot. Patients and methods: This prospective study was carried out on 41 patients with diabetic foot, 22 males and 19 females with mean age of 51 years. They underwent diffusion-weighted MR imaging of the foot. The apparent diffusion coefficient (ADC) values of the bony lesions were calculated by two reviewers and correlated with the surgical findings or biopsy. The kappa statistic (k) was used to estimate the proportion of inter-observer agreement of two reviewers. Results: The mean ADC of acute diabetic osteoarthropathy was 1.27 ± 0.19 × 10{sup −3} mm{sup 2}/s for reviewer 1 and 1.26 ± 0.21 × 10{sup −3} mm{sup 2}/s for reviewer 2. The mean ADC value in diabetic osteomyelitis was 0.86 ± 0.11 × 10{sup −3} mm{sup 2}/s for reviewer 1 and 0.85 ± 0.12 × 10{sup −3} mm{sup 2}/s for reviewer 2. There was excellent inter-observer agreement of ADC value of bony lesions in diabetic foot by both reviewers (K = 0.93). There was statistically significant difference in the ADC values of both groups (P = 0.001). The cut-off point of ADC value of both reviewers used in differentiating acute diabetic osteoarthropathy and osteomyelitis were 0.98 × 10{sup −3} mm{sup 2}/s and 1.04 × 10{sup −3} mm{sup 2}/s with an accuracy of 94% and 93% and area under the curve of 0.94 and 0.93 respectively. Conclusion: We conclude that the ADC value is a non-invasive imaging parameter that can help in differentiation of diabetic osteoarthropathy from osteomyelitis with excellent inter-observer agreement.

  8. Validation of the fifth edition BI-RADS ultrasound lexicon with comparison of fourth and fifth edition diagnostic performance using video clips

    International Nuclear Information System (INIS)

    Yoon, Jung Hyun; Kim, Min Jung; Lee, Hye Sun; Kim, Sung Hun; Youk, Ji Hyun; Jeong, Sun Hye; Kim, You Me

    2016-01-01

    The aim of this study was to evaluate the positive predictive value (PPV) and the diagnostic performance of the ultrasonographic descriptors in the fifth edition of BI-RADS, comparing with the fourth edition using video clips. From September 2013 to July 2014, 80 breast masses in 74 women (mean age, 47.5±10.7 years) from five institutions of the Korean Society of Breast Imaging were included. Two radiologists individually reviewed the static and video images and analyzed the images according to the fourth and fifth edition of BI-RADS. The PPV o