Sample records for dual axis radiographic

  1. Transverse beam motion on the second axis of the dual axis radiographic hydrodynamic test facility

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Caporaso, G J; Chen, Y J; Fawley, W M

    1999-03-23

    The accelerator on the second-axis of the Dual-Axis Radiographic Hydrodynamic Test (DARHT-II) facility will generate a 20 MeV, 2-4 kA, 2 µs long electron beam with an energy variation {<=} ± 0.5%. Four short current pulses with various lengths will be selected out of this 2 µs long current pulse and delivered to an x-ray converter target. The DARHT-II radiographic resolution requires these electron pulses to be focused to sub-millimeter spots on Bremsstrahlung targets with peak-to-peak transverse beam motion less than a few hundred microns. We have modeled the transverse beam motion, including the beam breakup instability, corkscrew motion, transversemore » resistive wall instability and beam induced transverse deflection in the kicker system, from the DARHT-II injector exit to the x-ray converter target. Simulations show that the transverse motion at the x-ray converters satisfies the DARHT-II radiographic requirements.« less

  2. Shot H3837: Darht's first dual-axis explosive experiment

    NASA Astrophysics Data System (ADS)

    Harsh, James F.; Hull, Lawrence; Mendez, Jacob; McNeil, Wendy Vogan

    2012-03-01

    Test H3837 was the first explosive shot performed in front of both flash x-ray axes at the Los Alamos Dual Axis Radiographic Hydrodynamic Test (DARHT) facility. Executed in November 2009, the shot was an explosively-driven metal flyer plate in a series of experiments designed to explore equation-of-state properties of shocked materials. Imaging the initial shock wave traveling through the flyer plate, DARHT Axis II captured the range of motion from the shock front emergence in the flyer to breakout at the free surface; the Axis I pulse provided a perpendicular perspective of the shot at a time coinciding with the third pulse of Axis II.

  3. Shot H3837: Darht's First Dual-Axis Explosive Experiment

    NASA Astrophysics Data System (ADS)

    Mendez, Jacob; McNeil, Wendy Vogan; Harsh, James; Hull, Lawrence

    2011-06-01

    Test H3837 was the first explosive shot performed in front of both flash x-ray axes at the Los Alamos Dual Axis Radiographic HydroTest (DARHT) facility. Executed in November 2009, the shot was an explosively-driven metal flyer plate in a series of experiments designed to explore equation-of-state properties of shocked materials. Imaging the initial shock wave traveling through the flyer plate, DARHT Axis II captured the range of motion from the shock front emergence in the flyer to breakout at the free surface; the Axis I pulse provided a perpendicular perspective of the shot at a time coinciding with the third pulse of Axis II. Since the days of the Manhattan Project, penetrating radiography with multiple frames from different viewing angles has remained a high-profile goal at the Laboratory. H3837 is merely the beginning of a bright future for two-axis penetrating radiography.

  4. Dual Axis Radiographic Hydrodynamic Test Facility

    Science.gov Websites

    4:17 How DARHT Works The weapons programs at Los Alamos have one principal mission: ensure the safety, security, and effectiveness of nuclear weapons in our nation's enduring stockpile. One critical completed a successful two-axis, multiframe hydrotest. Two additional successful tests-one of which was

  5. Comparative radiographic analysis on the anatomical axis in knee osteoarthritis cases: inter and intraobserver evaluation.

    PubMed

    Matos, Luiz Felipe; Giordano, Marcos; Cardoso, Gustavo Novaes; Farias, Rafael Baptista; E Albuquerque, Rodrigo Pires

    2015-01-01

    To make a comparative inter and intraobserver analysis on measurements of the anatomical axis between panoramic radiographs of the lower limbs in anteroposterior (AP) view with bipedal weight-bearing, on short film. An accuracy study comparing radiographic measurements on 47 knees of patients attending the knee surgery outpatient clinic due to osteoarthritis. The radiographic evaluation used was as standardized for the total knee arthroplasty program, including panoramic AP views of the lower limbs and short radiographs of the knees in AP and lateral views, all with bipedal weight-bearing. Following this, the anatomical axis of the lower limbs or the femorotibial angle was measured by five independent examiners on the panoramic and short AP radiographs; three of the examiners were considered to be more experienced and two, less experienced. All the measurements were made again by the same examiners after an interval of not less than 15 days. The statistical analysis was performed using the intraclass correlation coefficient, in order to evaluate the inter and intraobserver concordance of the anatomical axis measurements. From the statistical analysis, it was observed that there was strongly significant concordance between the anatomical axis measurements on the panoramic and short radiographs, for all the five examiners and for both measurements. Under the conditions studied, short radiographs were equivalent to panoramic radiographs for evaluating the anatomical axis of the lower limbs in patients with advanced osteoarthritis. The measurements used also showed high rates of inter and intraobserver concordance and reproducibility.

  6. Dual-energy KUB radiographic examination for the detection of renal calculus.

    PubMed

    Yen, Peggy; Bailly, Greg; Pringle, Christopher; Barnes, David

    2014-08-01

    The dual-energy radiographic technique has been proved to be clinically useful in the thorax. Herein, we attempt to apply this technique to the abdomen and pelvis in the context of renal colic. The visibility of renal calculi were assessed using various dual energy peak kilovoltage combination radiographs applied to standard phantoms. This technique demonstrates a higher than acceptable radiation dosage required to optimize the image quality and the optimized diagnostic quality is inferior to that of the standard Kidneys, Ureters, and Bladder radiograph. The dual-energy radiographic technique could not better identify the radiopaque renal calculi. Limiting technical considerations include the increased subcutaneous and peritoneal adipose tissue and the limited contrast between the soft tissue and underlying calculi. Copyright © 2014 AUR. Published by Elsevier Inc. All rights reserved.

  7. Static-stress analysis of dual-axis confinement vessel

    NASA Astrophysics Data System (ADS)

    Bultman, D. H.

    1992-11-01

    This study evaluates the static-pressure containment capability of a 6-ft-diameter, spherical vessel, made of HSLA-100 steel, to be used for high-explosive (HE) containment. The confinement vessel is designed for use with the Dual-Axis Radiographic Hydrotest Facility (DARHT) being developed at Los Alamos National Laboratory. Two sets of openings in the vessel are covered with x-ray transparent covers to allow radiographic imaging of an explosion as it occurs inside the vessel. The confinement vessel is analyzed as a pressure vessel based on the ASME Boiler and Pressure Vessel Code, Section 8, Division 1, and the Welding Research Council Bulletin, WRC-107. Combined stresses resulting from internal pressure and external loads on nozzles are calculated and compared with the allowable stresses for HSLA-100 steel. Results confirm that the shell and nozzles of the confinement vessel are adequately designed to safely contain the maximum residual pressure of 1675 psi that would result from an HE charge of 24.2 kg detonated in a vacuum. Shell stresses at the shell-to-nozzle interface, produced from external loads on the nozzles, were less than 400 psi. The maximum combined stress resulting from the internal pressure plus external loads was 16,070 psi, which is less than half the allowable stress of 42,375 psi for HSLA-100 steel.

  8. Measuring x-ray spectra of flash radiographic sources [PowerPoint

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Gehring, Amanda Elizabeth; Espy, Michelle A.; Haines, Todd Joseph

    2015-11-02

    The x-ray spectra of flash radiographic sources are difficult to measure. The sources measured were Radiographic Integrated Test Stand-6 (370 rad at 1 m; 50 ns pulse) and Dual Axis Radiographic Hydrodynamic Test Facility (DARHT) (550 rad at 1 m; 50 ns pulse). Features of the Compton spectrometer are described, and spectra are shown. Additional slides present data on instrumental calibration.

  9. Dual axis operation of a micromachined rate gyroscope

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Juneau, T.; Pisano, A.P.; Smith, J.

    Since micromachining technology has raised the prospect of fabricating high performance sensors without the associated high cost and large size, many researchers have investigated micromachined rate gyroscopes. The vast majority of research has focused on single input axis rate gyroscopes, but this paper presents work on a dual input axis micromachined rate gyroscope. The key to successful simultaneous dual axis operation is the quad symmetry of the circular oscillating rotor design. Untuned gyroscopes with mismatched modes yielded random walk as low as 10{degrees}/{radical}hour with cross sensitivity ranging from 6% to 16%. Mode frequency matching via electrostatic tuning allowed performance bettermore » than 2{degrees}/{radical}hour, but at the expense of excessive cross sensitivity.« less

  10. High-accuracy self-calibration method for dual-axis rotation-modulating RLG-INS

    NASA Astrophysics Data System (ADS)

    Wei, Guo; Gao, Chunfeng; Wang, Qi; Wang, Qun; Long, Xingwu

    2017-05-01

    Inertial navigation system has been the core component of both military and civil navigation systems. Dual-axis rotation modulation can completely eliminate the inertial elements constant errors of the three axes to improve the system accuracy. But the error caused by the misalignment angles and the scale factor error cannot be eliminated through dual-axis rotation modulation. And discrete calibration method cannot fulfill requirements of high-accurate calibration of the mechanically dithered ring laser gyroscope navigation system with shock absorbers. This paper has analyzed the effect of calibration error during one modulated period and presented a new systematic self-calibration method for dual-axis rotation-modulating RLG-INS. Procedure for self-calibration of dual-axis rotation-modulating RLG-INS has been designed. The results of self-calibration simulation experiment proved that: this scheme can estimate all the errors in the calibration error model, the calibration precision of the inertial sensors scale factor error is less than 1ppm and the misalignment is less than 5″. These results have validated the systematic self-calibration method and proved its importance for accuracy improvement of dual -axis rotation inertial navigation system with mechanically dithered ring laser gyroscope.

  11. Evaluation of the prototype dual-axis wall attitude measurement sensor

    NASA Technical Reports Server (NTRS)

    Wong, Douglas T.

    1994-01-01

    A prototype dual-axis electrolytic tilt sensor package for angular position measurements was built and evaluated in a laboratory environment. The objective was to investigate the use of this package for making wind tunnel wall attitude measurements for the National Transonic Facility (NTF) at NASA Langley Research Center (LaRC). The instrumentation may replace an existing, more costly, and less rugged servo accelerometer package (angle-of-attack package) currently in use. The dual-axis electrolytic tilt sensor package contains two commercial electrolytic tilt sensors thermally insulated with NTF foam, all housed within a stainless steel package. The package is actively heated and maintained at 160 F using foil heating elements. The laboratory evaluation consisted of a series of tests to characterize the linearity, repeatability, cross-axis interaction, lead wire effect, step response, thermal time constant, and rectification errors. Tests revealed that the total RMS errors for the x-axis sensor is 0.084 degree, and 0.182 degree for the y-axis sensor. The RMS errors are greater than the 0.01 degree specification required for NTF wall attitude measurements. It is therefore not a viable replacement for the angle-of-attack package in the NTF application. However, with some physical modifications, it can be used as an inexpensive 5-degree range dual-axis inclinometer with overall accuracy approaching 0.01 degree under less harsh environments. Also, the data obtained from the tests can be valuable for wind tunnel applications of most types of electrolytic tilt sensors.

  12. Design, Fabrication, and Modeling of a Novel Dual-Axis Control Input PZT Gyroscope.

    PubMed

    Chang, Cheng-Yang; Chen, Tsung-Lin

    2017-10-31

    Conventional gyroscopes are equipped with a single-axis control input, limiting their performance. Although researchers have proposed control algorithms with dual-axis control inputs to improve gyroscope performance, most have verified the control algorithms through numerical simulations because they lacked practical devices with dual-axis control inputs. The aim of this study was to design a piezoelectric gyroscope equipped with a dual-axis control input so that researchers may experimentally verify those control algorithms in future. Designing a piezoelectric gyroscope with a dual-axis control input is more difficult than designing a conventional gyroscope because the control input must be effective over a broad frequency range to compensate for imperfections, and the multiple mode shapes in flexural deformations complicate the relation between flexural deformation and the proof mass position. This study solved these problems by using a lead zirconate titanate (PZT) material, introducing additional electrodes for shielding, developing an optimal electrode pattern, and performing calibrations of undesired couplings. The results indicated that the fabricated device could be operated at 5.5±1 kHz to perform dual-axis actuations and position measurements. The calibration of the fabricated device was completed by system identifications of a new dynamic model including gyroscopic motions, electromechanical coupling, mechanical coupling, electrostatic coupling, and capacitive output impedance. Finally, without the assistance of control algorithms, the "open loop sensitivity" of the fabricated gyroscope was 1.82 μV/deg/s with a nonlinearity of 9.5% full-scale output. This sensitivity is comparable with those of other PZT gyroscopes with single-axis control inputs.

  13. Static-stress analysis of dual-axis safety vessel

    NASA Astrophysics Data System (ADS)

    Bultman, D. H.

    1992-11-01

    An 8 ft diameter safety vessel, made of HSLA-100 steel, is evaluated to determine its ability to contain the quasi-static residual pressure from a high explosive (HE) blast. The safety vessel is designed for use with the Dual-Axis Radiographic Hydrotest (DARHT) facility being developed at Los Alamos National Laboratory. A smaller confinement vessel fits inside the safety vessel and contains the actual explosion, and the safety vessel functions as a second layer of containment in the unlikely case of a confinement vessel leak. The safety vessel is analyzed as a pressure vessel based on the ASME Boiler and Pressure Vessel Code, Section 8, Division 1, and the Welding Research Council Bulletin, WRC107. Combined stresses that result from internal pressure and external loads on nozzles are calculated and compared to the allowable stresses for HSLA-100 steel. Results confirm that the shell and nozzle components are adequately designed for a static pressure of 830 psi, plus the maximum expected external loads. Shell stresses at the 'shell to nozzle' interface, produced from external loads on the nozzles, were less than 700 psi. The maximum combined stress resulting from the internal pressure plus external loads was 17,384 psi, which is significantly less than the allowable stress of 42,375 psi for HSLA-100 steel.

  14. A study of electrostatic spring softening for dual-axis micromirror

    NASA Astrophysics Data System (ADS)

    Zhao, Yi; E H Tay, Francis; Zhou, Guangya; Siong Chau, Fook

    2006-08-01

    Electrostatic spring softening is an important characteristic of electrostatically actuated dual-axis micromirror, since it lowers the resonant frequencies. This paper presents an approach based on approximating the electrostatic forces by the first-order Taylor's series expansion to investigate this characteristic. The dual-axis micromirror studied in this paper has three motion modes, two torsional (about x- and y-axis, respectively) and one translational (about z-axis). The stiffnesses of all these modes are softened by a DC bias voltage applied to the mirror plate. The resonant frequencies are lowered with the increment of the bias voltage. The relationship of the bias voltage and the resonant frequencies of all the motion modes is derived. The analytical results show that the resonant frequency curves are affected by the capacitor geometries, i.e. the gap between the mirror plate and the electrodes and the electrodes size. The lowering curves drop slowly when the bias voltage is small. While for large bias voltage, the lowering curves drop rapidly. The experiment results are consistent with those obtained by the analytical approach.

  15. Human performance evaluation in dual-axis critical task tracking

    NASA Technical Reports Server (NTRS)

    Ritchie, M. L.; Nataraj, N. S.

    1975-01-01

    A dual axis tracking using a multiloop critical task was set up to evaluate human performance. The effects of control stick variation and display formats are evaluated. A secondary loading was used to measure the degradation in tracking performance.

  16. Low-loss off-axis feeds for symmetric dual-reflector antennas

    NASA Technical Reports Server (NTRS)

    Veruttipong, T.; Galindo-Israel, V.; Imbriale, W.

    1986-01-01

    Circularly symmetric, dual reflector, high gain antenna systems often require feeds placed off the system's axis because of the need for multiple feeds to use the reflector antenna. Also, the constraint requiring the hyperboloid or shaped subreflector to remain circularly symmetric is sometimes added. In a Cassegrainian system, the subreflector and feed may be rotated off axis around the paraboloid focus and retain main reflector focusing. However, substantial spillover results in considerable noise with a high gain/low noise temperature system. In a shaped system, the tilt of the shaped subreflector and feed together results in substantial defocusing as well as spillover noise. If the subreflector is tilted approximately one-half the angle of the feed tilt in either the Cassegrainian or the dual shaped reflector antenna, it is found that spillover and noise are substantially reduced with tolerable defocusing. An extensive numerical analysis of these effects was conducted to determine the characteristics of a planned 70-meter, dual shaped reflector versus Cassegrainian antenna and to gain some understanding of the cause of the observed effects.

  17. A dual-porosity reactive-transport model of off-axis hydrothermal systems

    NASA Astrophysics Data System (ADS)

    Farahat, N. X.; Abbot, D. S.; Archer, D. E.

    2017-12-01

    We built a dual-porosity reactive-transport 2D numerical model of off-axis pillow basalt alteration. An "outer chamber" full of porous glassy material supports significant seawater flushing, and an "inner chamber", which represents the more crystalline interior of a pillow, supports diffusive alteration. Hydrothermal fluids in the two chambers interact, and the two chambers are coupled to 2D flows. In a few million years of low-temperature alteration, the dual-porosity model predicts progressive stages of alteration that have been observed in drilled crust. A single-porosity model, with all else being equal, does not predict alteration stages as well. The dual-chamber model also does a better job than the single-chamber model at predicting the types of minerals expected in off-axis environments. We validate the model's ability to reproduce observations by configuring it to represent a thoroughly-studied transect of the Juan de Fuca Ridge eastern flank.

  18. Sheet-scanned dual-axis confocal microscopy using Richardson-Lucy deconvolution.

    PubMed

    Wang, D; Meza, D; Wang, Y; Gao, L; Liu, J T C

    2014-09-15

    We have previously developed a line-scanned dual-axis confocal (LS-DAC) microscope with subcellular resolution suitable for high-frame-rate diagnostic imaging at shallow depths. Due to the loss of confocality along one dimension, the contrast (signal-to-background ratio) of a LS-DAC microscope is deteriorated compared to a point-scanned DAC microscope. However, by using a sCMOS camera for detection, a short oblique light-sheet is imaged at each scanned position. Therefore, by scanning the light sheet in only one dimension, a thin 3D volume is imaged. Both sequential two-dimensional deconvolution and three-dimensional deconvolution are performed on the thin image volume to improve the resolution and contrast of one en face confocal image section at the center of the volume, a technique we call sheet-scanned dual-axis confocal (SS-DAC) microscopy.

  19. Performance Evaluation of Dual-axis Tracking System of Parabolic Trough Solar Collector

    NASA Astrophysics Data System (ADS)

    Ullah, Fahim; Min, Kang

    2018-01-01

    A parabolic trough solar collector with the concentration ratio of 24 was developed in the College of Engineering; Nanjing Agricultural University, China with the using of the TracePro software an optical model built. Effects of single-axis and dual-axis tracking modes, azimuth and elevating angle tracking errors on the optical performance were investigated and the thermal performance of the solar collector was experimentally measured. The results showed that the optical efficiency of the dual-axis tracking was 0.813% and its year average value was 14.3% and 40.9% higher than that of the eat-west tracking mode and north-south tracking mode respectively. Further, form the results of the experiment, it was concluded that the optical efficiency was affected significantly by the elevation angle tracking errors which should be kept below 0.6o. High optical efficiency could be attained by using dual-tracking mode even though the tracking precision of one axis was degraded. The real-time instantaneous thermal efficiency of the collector reached to 0.775%. In addition, the linearity of the normalized efficiency was favorable. The curve of the calculated thermal efficiency agreed well with the normalized instantaneous efficiency curve derived from the experimental data and the maximum difference between them was 10.3%. This type of solar collector should be applied in middle-scale thermal collection systems.

  20. Development of a dual-axis hybrid-type tactile sensor using PET film

    NASA Astrophysics Data System (ADS)

    Seonggi, Kim; Koo, Ja Choon; Choi, Hyouk Ryeol; Moon, Hyungpil

    2013-04-01

    In previous work, a dual-axis hybrid-type tactile sensor using PDMS (Polydimethylsiloxane) with a pair of metal electrodes, (which were deposited directly on the PDMS surface), was proposed. The hybrid sensor can measure the normal force and the shear force from the measurement of the change of capacitance and resistance values from the one pair of electrodes. However, the metal is hard to be deposited on the surface of the PDMS because the PDMS is hydrophobic. The hydrophobic surface can be changed to hydrophilic using O2 Plasma treatment or UV treatment. When O2 plasma treatment or UV treatment is used, there is the problem that the processing of the metal deposition and the wiring completed in a very short period of limited time. Also, the deposited metal on the surface of the PDMS is easy to break because the deposited metal is exposed in the air. In this paper, we propose a dual-axis hybrid-type tactile sensor where the PET (polyethylene terephthalate) film is inserted between the PDMS films. The deposited metal is not removed easily from the PET film because the adhesion is strong. Also, the PDMS surrounding the PET film plays the roles of dielectric elastomer and shielding the deposited metal from the external environment at same time. Experimental results verify the effectiveness of the fabricated dual-axis hybrid-type force sensor.

  1. Validation of a new radiographic measurement of acetabular version: the transverse axis distance (TAD).

    PubMed

    Nitschke, Ashley; Lambert, Jeffery R; Glueck, Deborah H; Jesse, Mary Kristen; Mei-Dan, Omer; Strickland, Colin; Petersen, Brian

    2015-11-01

    This study has three aims: (1) validate a new radiographic measure of acetabular version, the transverse axis distance (TAD) by showing equivalent TAD accuracy in predicting CT equatorial acetabular version when compared to a previously validated, but more cumbersome, radiographic measure, the p/a ratio; (2) establish predictive equations of CT acetabular version from TAD; (3) calculate a sensitive and specific cut point for predicting excessive CT acetabular anteversion using TAD. A 14-month retrospective review was performed of patients who had undergone a dedicated MSK CT pelvis study and who also had a technically adequate AP pelvis radiograph. Two trained observers measured the radiographic p/a ratio, TAD, and CT acetabular equatorial version for 110 hips on a PACS workstation. Mixed model analysis was used to find prediction equations, and ROC analysis was used to evaluate the diagnostic accuracy of p/a ratio and TAD. CT equatorial acetabular version can accurately be predicted from either p/a ratio (p < 0.001) or TAD (p < 0.001). The diagnostic accuracies of p/a ratio and TAD are comparable (p =0.46). Patients whose TAD is higher than 17 mm may have excessive acetabular anteversion. For that cutpoint, the sensitivity of TAD is 0.73, with specificity of 0.82. TAD is an accurate radiographic predictor of CT acetabular anteversion and provides an easy-to-use and intuitive point-of-care assessment of acetabular version in patients with hip pain.

  2. DARHT Axis-I Diode Simulations II: Geometrical Scaling

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ekdahl, Carl A. Jr.

    2012-06-14

    Flash radiography of large hydrodynamic experiments driven by high explosives is a venerable diagnostic technique in use at many laboratories. Many of the largest hydrodynamic experiments study mockups of nuclear weapons, and are often called hydrotests for short. The dual-axis radiography for hydrodynamic testing (DARHT) facility uses two electron linear-induction accelerators (LIA) to produce the radiographic source spots for perpendicular views of a hydrotest. The first of these LIAs produces a single pulse, with a fixed {approx}60-ns pulsewidth. The second axis LIA produces as many as four pulses within 1.6-{micro}s, with variable pulsewidths and separation. There are a wide varietymore » of hydrotest geometries, each with a unique radiographic requirement, so there is a need to adjust the radiographic dose for the best images. This can be accomplished on the second axis by simply adjusting the pulsewidths, but is more problematic on the first axis. Changing the beam energy or introducing radiation attenuation also changes the spectrum, which is undesirable. Moreover, using radiation attenuation introduces significant blur, increasing the effective spot size. The dose can also be adjusted by changing the beam kinetic energy. This is a very sensitive method, because the dose scales as the {approx}2.8 power of the energy, but it would require retuning the accelerator. This leaves manipulating the beam current as the best means for adjusting the dose, and one way to do this is to change the size of the cathode. This method has been proposed, and is being tested. This article describes simulations undertaken to develop scaling laws for use as design tools in changing the Axis-1 beam current by changing the cathode size.« less

  3. Confocal fluorescence microscope with dual-axis architecture and biaxial postobjective scanning

    PubMed Central

    Wang, Thomas D.; Contag, Christopher H.; Mandella, Michael J.; Chan, Ning Y.; Kino, Gordon S.

    2007-01-01

    We present a novel confocal microscope that has dual-axis architecture and biaxial postobjective scanning for the collection of fluorescence images from biological specimens. This design uses two low-numerical-aperture lenses to achieve high axial resolution and long working distance, and the scanning mirror located distal to the lenses rotates along the orthogonal axes to produce arc-surface images over a large field of view (FOV). With fiber optic coupling, this microscope can potentially be scaled down to millimeter dimensions via microelectromechanical systems (MEMS) technology. We demonstrate a benchtop prototype with a spatial resolution ≤4.4 μm that collects fluorescence images with a high SNR and a good contrast ratio from specimens expressing GFP. Furthermore, the scanning mechanism produces only small differences in aberrations over the image FOV. These results demonstrate proof of concept of the dual-axis confocal architecture for in vivo molecular and cellular imaging. PMID:15250760

  4. AXIS: an instrument for imaging Compton radiographs using the Advanced Radiography Capability on the NIF.

    PubMed

    Hall, G N; Izumi, N; Tommasini, R; Carpenter, A C; Palmer, N E; Zacharias, R; Felker, B; Holder, J P; Allen, F V; Bell, P M; Bradley, D; Montesanti, R; Landen, O L

    2014-11-01

    Compton radiography is an important diagnostic for Inertial Confinement Fusion (ICF), as it provides a means to measure the density and asymmetries of the DT fuel in an ICF capsule near the time of peak compression. The AXIS instrument (ARC (Advanced Radiography Capability) X-ray Imaging System) is a gated detector in development for the National Ignition Facility (NIF), and will initially be capable of recording two Compton radiographs during a single NIF shot. The principal reason for the development of AXIS is the requirement for significantly improved detection quantum efficiency (DQE) at high x-ray energies. AXIS will be the detector for Compton radiography driven by the ARC laser, which will be used to produce Bremsstrahlung X-ray backlighter sources over the range of 50 keV-200 keV for this purpose. It is expected that AXIS will be capable of recording these high-energy x-rays with a DQE several times greater than other X-ray cameras at NIF, as well as providing a much larger field of view of the imploded capsule. AXIS will therefore provide an image with larger signal-to-noise that will allow the density and distribution of the compressed DT fuel to be measured with significantly greater accuracy as ICF experiments are tuned for ignition.

  5. Dual axis translation apparatus and system for translating an optical beam and related method

    DOEpatents

    Cassidy, Kelly

    1991-01-01

    A dual axis translation device and system in accordance with this invention, for translating an optical beam along both an x-axis and a y-axis which are perpendicular to one another, has a beam directing means acting on said optical beam for directing the beam along a particular path transverse to said x and y axes. An arrangement supporting said beam directing means for movement in the x and y direction within a given plane is provided. The arrangement includes a first means for translating said beam directing means along the x-axis in said given plane in order to translate the beam along said x-axis. The arrangement comprises a second means for translating said beam directing means along the y-axis in said given plane in order to translate the beam along said y-axis.

  6. Sun-Relative Pointing for Dual-Axis Solar Trackers Employing Azimuth and Elevation Rotations

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Riley, Daniel; Hansen, Clifford W.

    Dual axis trackers employing azimuth and elevation rotations are common in the field of photovoltaic (PV) energy generation. Accurate sun-tracking algorithms are widely available. However, a steering algorithm has not been available to accurately point the tracker away from the sun such that a vector projection of the sun beam onto the tracker face falls along a desired path relative to the tracker face. We have developed an algorithm which produces the appropriate azimuth and elevation angles for a dual axis tracker when given the sun position, desired angle of incidence, and the desired projection of the sun beam ontomore » the tracker face. Development of this algorithm was inspired by the need to accurately steer a tracker to desired sun-relative positions in order to better characterize the electro-optical properties of PV and CPV modules.« less

  7. Tracking formulas and strategies for a receiver oriented dual-axis tracking toroidal heliostat

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Guo, Minghuan; Wang, Zhifeng; Liang, Wenfeng

    2010-06-15

    A 4 m x 4 m toroidal heliostat with receiver oriented dual-axis tracking, also called spinning-elevation tracking, was developed as an auxiliary heat source for a hydrogen production system. A series of spinning-elevation tracking formulas have been derived for this heliostat. This included basic tracking formulas, a formula for the elevation angle for heliostat with a mirror-pivot offset, and a more general formula for the biased elevation angle. This paper presents the new tracking formulas in detail and analyzes the accuracy of applying a simplifying approximation. The numerical results show these receiver oriented dual-axis tracking formula approximations are accurate tomore » within 2.5 x 10{sup -6} m in image plane. Some practical tracking strategies are discussed briefly. Solar images from the toroidal heliostat at selected times are also presented. (author)« less

  8. AXIS: An instrument for imaging Compton radiographs using the Advanced Radiography Capability on the NIF

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hall, G. N., E-mail: hall98@llnl.gov; Izumi, N.; Tommasini, R.

    2014-11-15

    Compton radiography is an important diagnostic for Inertial Confinement Fusion (ICF), as it provides a means to measure the density and asymmetries of the DT fuel in an ICF capsule near the time of peak compression. The AXIS instrument (ARC (Advanced Radiography Capability) X-ray Imaging System) is a gated detector in development for the National Ignition Facility (NIF), and will initially be capable of recording two Compton radiographs during a single NIF shot. The principal reason for the development of AXIS is the requirement for significantly improved detection quantum efficiency (DQE) at high x-ray energies. AXIS will be the detectormore » for Compton radiography driven by the ARC laser, which will be used to produce Bremsstrahlung X-ray backlighter sources over the range of 50 keV–200 keV for this purpose. It is expected that AXIS will be capable of recording these high-energy x-rays with a DQE several times greater than other X-ray cameras at NIF, as well as providing a much larger field of view of the imploded capsule. AXIS will therefore provide an image with larger signal-to-noise that will allow the density and distribution of the compressed DT fuel to be measured with significantly greater accuracy as ICF experiments are tuned for ignition.« less

  9. A comparison of radiographic anatomic axis knee alignment measurements and cross-sectional associations with knee osteoarthritis.

    PubMed

    Goulston, L M; Sanchez-Santos, M T; D'Angelo, S; Leyland, K M; Hart, D J; Spector, T D; Cooper, C; Dennison, E M; Hunter, D; Arden, N K

    2016-04-01

    Malalignment is associated with knee osteoarthritis (KOA), however, the optimal anatomic axis (AA) knee alignment measurement on a standard limb radiograph (SLR) is unknown. This study compares one-point (1P) and two-point (2P) AA methods using three knee joint centre locations and examines cross-sectional associations with symptomatic radiographic knee osteoarthritis (SRKOA), radiographic knee osteoarthritis (RKOA) and knee pain. AA alignment was measured six different ways using the KneeMorf software on 1058 SLRs from 584 women in the Chingford Study. Cross-sectional associations with principal outcome SRKOA combined with greatest reproducibility determined the optimal 1P and 2P AA method. Appropriate varus/neutral/valgus alignment categories were established using logistic regression with generalised estimating equation models fitted with restricted cubic spline function. The tibial plateau centre displayed greatest reproducibility and associations with SRKOA. As mean 1P and 2P values differed by >2°, new alignment categories were generated for 1P: varus <178°, neutral 178-182°, valgus >182° and for 2P methods: varus <180°, neutral 180-185°, valgus >185°. Varus vs neutral alignment was associated with a near 2-fold increase in SRKOA and RKOA, and valgus vs neutral for RKOA using 2P method. Nonsignificant associations were seen for 1P method for SRKOA, RKOA and knee pain. AA alignment was associated with SRKOA and the tibial plateau centre had the strongest association. Differences in AA alignment when 1P vs 2P methods were compared indicated bespoke alignment categories were necessary. Further replication and validation with mechanical axis alignment comparison is required. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

  10. A comparison of radiographic anatomic axis knee alignment measurements and cross-sectional associations with knee osteoarthritis

    PubMed Central

    Goulston, L.M.; Sanchez-Santos, M.T.; D'Angelo, S.; Leyland, K.M.; Hart, D.J.; Spector, T.D.; Cooper, C.; Dennison, E.M.; Hunter, D.; Arden, N.K.

    2016-01-01

    Summary Objective Malalignment is associated with knee osteoarthritis (KOA), however, the optimal anatomic axis (AA) knee alignment measurement on a standard limb radiograph (SLR) is unknown. This study compares one-point (1P) and two-point (2P) AA methods using three knee joint centre locations and examines cross-sectional associations with symptomatic radiographic knee osteoarthritis (SRKOA), radiographic knee osteoarthritis (RKOA) and knee pain. Methods AA alignment was measured six different ways using the KneeMorf software on 1058 SLRs from 584 women in the Chingford Study. Cross-sectional associations with principal outcome SRKOA combined with greatest reproducibility determined the optimal 1P and 2P AA method. Appropriate varus/neutral/valgus alignment categories were established using logistic regression with generalised estimating equation models fitted with restricted cubic spline function. Results The tibial plateau centre displayed greatest reproducibility and associations with SRKOA. As mean 1P and 2P values differed by >2°, new alignment categories were generated for 1P: varus <178°, neutral 178–182°, valgus >182° and for 2P methods: varus <180°, neutral 180–185°, valgus >185°. Varus vs neutral alignment was associated with a near 2-fold increase in SRKOA and RKOA, and valgus vs neutral for RKOA using 2P method. Nonsignificant associations were seen for 1P method for SRKOA, RKOA and knee pain. Conclusions AA alignment was associated with SRKOA and the tibial plateau centre had the strongest association. Differences in AA alignment when 1P vs 2P methods were compared indicated bespoke alignment categories were necessary. Further replication and validation with mechanical axis alignment comparison is required. PMID:26700504

  11. Design optimization of dual-axis driving mechanism for satellite antenna with two planar revolute clearance joints

    NASA Astrophysics Data System (ADS)

    Bai, Zheng Feng; Zhao, Ji Jun; Chen, Jun; Zhao, Yang

    2018-03-01

    In the dynamic analysis of satellite antenna dual-axis driving mechanism, it is usually assumed that the joints are ideal or perfect without clearances. However, in reality, clearances in joints are unavoidable due to assemblage, manufacturing errors and wear. When clearance is introduced to the mechanism, it will lead to poor dynamic performances and undesirable vibrations due to impact forces in clearance joint. In this paper, a design optimization method is presented to reduce the undesirable vibrations of satellite antenna considering clearance joints in dual-axis driving mechanism. The contact force model in clearance joint is established using a nonlinear spring-damper model and the friction effect is considered using a modified Coulomb friction model. Firstly, the effects of clearances on dynamic responses of satellite antenna are investigated. Then the optimization method for dynamic design of the dual-axis driving mechanism with clearance is presented. The objective of the optimization is to minimize the maximum absolute vibration peak of antenna acceleration by reducing the impact forces in clearance joint. The main consideration here is to optimize the contact parameters of the joint elements. The contact stiffness coefficient, damping coefficient and the dynamic friction coefficient for clearance joint elements are taken as the optimization variables. A Generalized Reduced Gradient (GRG) algorithm is used to solve this highly nonlinear optimization problem for dual-axis driving mechanism with clearance joints. The results show that the acceleration peaks of satellite antenna and contact forces in clearance joints are reduced obviously after design optimization, which contributes to a better performance of the satellite antenna. Also, the application and limitation of the proposed optimization method are discussed.

  12. Field optimization method of a dual-axis atomic magnetometer based on frequency-response and dynamics

    NASA Astrophysics Data System (ADS)

    Xing, Li; Quan, Wei; Fan, Wenfeng; Li, Rujie; Jiang, Liwei; Fang, Jiancheng

    2018-05-01

    The frequency-response and dynamics of a dual-axis spin-exchange-relaxation-free (SERF) atomic magnetometer are investigated by means of transfer function analysis. The frequency-response at different bias magnetic fields is tested to demonstrate the effect of the residual magnetic field. The resonance frequency of alkali atoms and magnetic linewidth can be obtained simultaneously through our theoretical model. The coefficient of determination of the fitting results is superior to 0.995 with 95% confidence bounds. Additionally, step responses are applied to analyze the dynamics of the control system and the effect of imperfections. Finally, a noise-limited magnetic field resolution of 15 fT {{\\sqrt{Hz}}-1} has been achieved for our dual-axis SERF atomic magnetometer through magnetic field optimization.

  13. Dual-axis high-data-rate atom interferometer via cold ensemble exchange

    DOE PAGES

    Rakholia, Akash V.; McGuinness, Hayden J.; Biedermann, Grant W.

    2014-11-24

    We demonstrate a dual-axis accelerometer and gyroscope atom interferometer, which can form the building blocks of a six-axis inertial measurement unit. By recapturing the atoms after the interferometer sequence, we maintain a large atom number at high data rates of 50 to 100 measurements per second. Two cold ensembles are formed in trap zones located a few centimeters apart and are launched toward one another. During their ballistic trajectory, they are interrogated with a stimulated Raman sequence, detected, and recaptured in the opposing trap zone. As a result, we achieve sensitivities at μg/ √Hz and μrad/s/ √Hz levels, making thismore » a compelling prospect for expanding the use of atom interferometer inertial sensors beyond benign laboratory environments.« less

  14. Attenuation and image noise level based online z-axis tube current modulation for CT scans independent with localizer radiograph: simulation study and results

    NASA Astrophysics Data System (ADS)

    Tian, Yi; Chen, Mahao; Kong, Jun

    2009-02-01

    With the online z-axis tube current modulation (OZTCM) technique proposed by this work, full automatic exposure control (AEC) for CT systems could be realized with online feedback not only for angular tube current modulation (TCM) but also for z-axis TCM either. Then the localizer radiograph was not required for TCM any more. OZTCM could be implemented with 2 schemes as attenuation based μ-OZTCM and image noise level based μ-OZTCM. Respectively the maximum attenuation of projection readings and standard deviation of reconstructed images can be used to modulate the tube current level in z-axis adaptively for each half (180 degree) or full (360 degree) rotation. Simulation results showed that OZTCM achieved better noise level than constant tube current scan case by using same total dose in mAs. The OZTCM can provide optimized base tube current level for angular TCM to realize an effective auto exposure control when localizer radiograph is not available or need to be skipped for simplified scan protocol in case of emergency procedure or children scan, etc.

  15. Modulated-alignment dual-axis (MAD) confocal microscopy for deep optical sectioning in tissues

    PubMed Central

    Leigh, Steven Y.; Chen, Ye; Liu, Jonathan T.C.

    2014-01-01

    A strategy is presented to enable optical-sectioning microscopy with improved contrast and imaging depth using low-power (0.5 - 1 mW) diode laser illumination. This technology combines the inherent strengths of focal-modulation microscopy and dual-axis confocal (DAC) microscopy for rejecting out-of-focus and multiply scattered background light in tissues. The DAC architecture is unique in that it utilizes an intersecting pair of illumination and collection beams to improve the spatial-filtering and optical-sectioning performance of confocal microscopy while focal modulation selectively ‘labels’ in-focus signals via amplitude modulation. Simulations indicate that modulating the spatial alignment of dual-axis beams at a frequency f generates signals from the focal volume of the microscope that are modulated at 2f with minimal modulation of background signals, thus providing nearly an order-of-magnitude improvement in optical-sectioning contrast compared to DAC microscopy alone. Experiments show that 2f lock-in detection enhances contrast and imaging depth within scattering phantoms and fresh tissues. PMID:24940534

  16. Concentrations of Radionuclides and Trace Elements in Environmantal Media arond te Dual-Axis Radiographic Hydrodynamic Test Facilit at Los Alamos National Laboratory during 2005

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    G.J.Gonzales; P.R. Fresquez; C.D.Hathcock

    2006-05-15

    The Mitigation Action Plan (MAP) for the Dual-Axis Radiographic Hydrodynamic Test (DARHT) facility at Los Alamos National Laboratory requires that samples of biotic and abiotic media be collected after operations began to determine if there are any human health or environmental impacts. The DARHT facility is the Laboratory's principal explosive test facility. To this end, samples of soil and sediment, vegetation, bees, and birds were collected around the facility in 2005 and analyzed for concentrations of {sup 3}H, {sup 137}Cs, {sup 90}Sr, {sup 238}Pu, {sup 239,240}Pu, {sup 241}Am, {sup 234}U, {sup 235}U, {sup 238}U, Ag, As, Ba, Be, Cd, Cr,more » Cu, Hg, Ni, Pb, Sb, Se, and Tl. Bird populations have also been monitored. Contaminant results, which represent up to six sample years since the start of operations, were compared with (1) baseline statistical reference levels (BSRLs) established over a four-year preoperational period before DARHT facility operations, (2) screening levels (SLs), and (3) regulatory standards. Most radionuclides and trace elements were below BSRLs and those few samples that contained radionuclides and trace elements above BSRLs were below SLs. Concentrations of radionuclides and nonradionuclides in biotic and abiotic media around the DARHT facility do not pose a significant human health hazard. The total number of birds captured and number of species represented were similar in 2003 and 2004, but both of these parameters increased substantially in 2005. Periodic interruption of the scope and schedule identified in the MAP generally should have no impact on meeting the intent of the MAP. The risk of not sampling one of the five media in any given year is that if a significant impact to contaminant levels were to occur there would exist a less complete understanding of the extent of the change to the baseline for these media and to the ecosystem as a whole. Since the MAP is a requirement that was established under the regulatory framework of

  17. A feasibility study of stationary and dual-axis tracking grid-connected photovoltaic systems in the Upper Midwest

    NASA Astrophysics Data System (ADS)

    Warren, Ryan Duwain

    Three primary objectives were defined for this work. The first objective was to determine, assess, and compare the performance, heat transfer characteristics, economics, and feasibility of real-world stationary and dual-axis tracking grid-connected photovoltaic (PV) systems in the Upper Midwest. This objective was achieved by installing two grid-connected PV systems with different mounting schemes in central Iowa, implementing extensive data acquisition systems, monitoring operation of the PV systems for one full year, and performing detailed experimental performance and economic studies. The two PV systems that were installed, monitored, and analyzed included a 4.59 kWp roof-mounted stationary system oriented for maximum annual energy production, and a 1.02 kWp pole-mounted actively controlled dual-axis tracking system. The second objective was to demonstrate the actual use and performance of real-world stationary and dual-axis tracking grid-connected PV systems used for building energy generation applications. This objective was achieved by offering the installed PV systems to the public for demonstration purposes and through the development of three computer-based tools: a software interface that has the ability to display real-time and historical performance and meteorological data of both systems side-by-side, a software interface that shows real-time and historical video and photographs of each system, and a calculator that can predict performance and economics of stationary and dual-axis tracking grid-connected PV systems at various locations in the United States. The final objective was to disseminate this work to social, professional, scientific, and academic communities in a way that is applicable, objective, accurate, accessible, and comprehensible. This final objective will be addressed by publishing the results of this work and making the computer-based tools available on a public website (www.energy.iastate.edu/Renewable/solar). Detailed experimental

  18. Design and implementation of a Sun tracker with a dual-axis single motor for an optical sensor-based photovoltaic system.

    PubMed

    Wang, Jing-Min; Lu, Chia-Liang

    2013-03-06

    The dual threats of energy depletion and global warming place the development of methods for harnessing renewable energy resources at the center of public interest. Solar energy is one of the most promising renewable energy resources. Sun trackers can substantially improve the electricity production of a photovoltaic (PV) system. This paper proposes a novel design of a dual-axis solar tracking PV system which utilizes the feedback control theory along with a four-quadrant light dependent resistor (LDR) sensor and simple electronic circuits to provide robust system performance. The proposed system uses a unique dual-axis AC motor and a stand-alone PV inverter to accomplish solar tracking. The control implementation is a technical innovation that is a simple and effective design. In addition, a scaled-down laboratory prototype is constructed to verify the feasibility of the scheme. The effectiveness of the Sun tracker is confirmed experimentally. To conclude, the results of this study may serve as valuable references for future solar energy applications.

  19. Design and Implementation of a Sun Tracker with a Dual-Axis Single Motor for an Optical Sensor-Based Photovoltaic System

    PubMed Central

    Wang, Jing-Min; Lu, Chia-Liang

    2013-01-01

    The dual threats of energy depletion and global warming place the development of methods for harnessing renewable energy resources at the center of public interest. Solar energy is one of the most promising renewable energy resources. Sun trackers can substantially improve the electricity production of a photovoltaic (PV) system. This paper proposes a novel design of a dual-axis solar tracking PV system which utilizes the feedback control theory along with a four-quadrant light dependent resistor (LDR) sensor and simple electronic circuits to provide robust system performance. The proposed system uses a unique dual-axis AC motor and a stand-alone PV inverter to accomplish solar tracking. The control implementation is a technical innovation that is a simple and effective design. In addition, a scaled-down laboratory prototype is constructed to verify the feasibility of the scheme. The effectiveness of the Sun tracker is confirmed experimentally. To conclude, the results of this study may serve as valuable references for future solar energy applications. PMID:23467030

  20. Integration of an Apple II Plus Computer into an Existing Dual Axis Sun Tracker System.

    DTIC Science & Technology

    1984-06-01

    Identify by block number) S, tpec l Sun Tracker System Solar Energy Apple II Plus Computer 20. ABSTRACT (’ ntlnue on reveree ide If neceesery end...14 4. Dual Axis Sun Tracker (Side View) ----------------- 15 5. Solar Tracker System Block Diagram ---------------- 17 6. Plug Wiring Diagram for Top...sources will be competitive. Already many homes have solar collectors and other devices designed to decrease the consumption of gas, oil, and

  1. Comparison of Mechanical Axis and Dynamic Range Assessed with Weight Bearing Radiographs and Navigation System in Closed Wedge High Tibial Osteotomy

    PubMed Central

    Bae, Dae Kyung; Lee, Jong Whan; Cho, Seong Jin; Song, Sang Jun

    2017-01-01

    Purpose To compare navigation and weight bearing radiographic measurements of mechanical axis (MA) before and after closed wedge high tibial osteotomy (HTO) and to evaluate post-osteotomy changes in MA assessed during application of external varus or valgus force. Materials and Methods Data from 30 consecutive patients (30 knees) who underwent computer-assisted closed-wedge HTO were prospectively analyzed. Pre- and postoperative weight bearing radiographic evaluation of MA was performed. Under navigation guidance, pre- and post-osteotomy MA values were measured in an unloaded position. Any change in the post-osteotomy MA in response to external varus or valgus force, which was named as dynamic range, was evaluated with the navigation system. The navigation and weight bearing radiographic measurements were compared. Results Although there was a positive correlation between navigation and radiographic measurements, the reliability of navigation measurements of coronal alignment was reduced after osteotomy and wedge closing. The mean post-osteotomy MA value measured with the navigation was 3.5°±0.8° valgus in an unloaded position. It was 1.3°±0.8° valgus under varus force and 5.8°±1.1° valgus under valgus force. The average dynamic range was >±2°. Conclusions Potential differences between the postoperative MAs assessed by weight bearing radiographs and the navigation system in unloaded position should be considered during computer-assisted closed wedge HTO. Care should be taken to keep the dynamic range within the permissible range of alignment goal in HTO. PMID:28854769

  2. Variability of single-leg versus double-leg stance radiographs in the varus knee.

    PubMed

    Chen, Andrew; Rich, Valerie; Bain, Elizabeth; Sterett, William I

    2009-07-01

    We evaluated measured radiographic parameter variability between single-leg stance (SLS) and double-leg stance (DLS) radiographs in patients with varus knee malalignment, indicated for high tibial osteotomy. Fifty-three consecutive knees (mean, 49 years; range, 18-79 years) were evaluated for varus thrust. SLS and DLS radiographs were obtained. A single blinded observer measured mechanical axis angles and weight-bearing line (WBL) deviation using a goniometer. Mechanical axis angles averaged 9.1 degrees (DLS) and 11.3 degrees (SLS). SLS radiographs averaged 9% greater WBL medialization than did DLS. Medial opening averaged 16.4 mm (DLS) and 18.8 mm (SLS). DLS and SLS radiographs showed no significant differences in patients without varus thrust. Patients with varus thrust demonstrated differences in mechanical axis angles (DLS, 9.4 degrees; SLS, 12.2 degrees), WBL deviation (12.1% less), medialization (DLS), and medial opening necessary for correction (DLS, 16.6 mm; SLS, 20.3 mm). In varus thrust, SLS radiographs more closely replicate dynamic knee malalignment, possibly providing more accurate measurements of angular deformity.

  3. Radiographic localization of unerupted mandibular anterior teeth.

    PubMed

    Jacobs, S G

    2000-10-01

    The parallax method and the use of 2 radiographs taken at right angles to each other are the 2 methods generally used to accurately localize teeth. For the parallax method, the combination of a rotational panoramic radiograph with an occlusal radiograph is recommended. This combination involves a vertical x-ray tube shift. Three case reports are presented that illustrate: (1) how this combination can accurately localize unerupted mandibular anterior teeth, (2) how a deceptive appearance of the labiolingual position of the unerupted tooth can be produced in an occlusal radiograph, (3) how increasing the vertical angle of the tube for the occlusal radiograph makes the tube shift easier to discern, (4) why occlusal radiographs are preferable to periapical radiographs for tube shifts, and (5) how localization can also be carried out with 2 radiographs at right angles to each other, one of which is an occlusal radiograph taken with the x-ray tube directed along the long axis of the reference tooth.

  4. Dual-axis reflective continuous-wave terahertz confocal scanning polarization imaging and image fusion

    NASA Astrophysics Data System (ADS)

    Zhou, Yi; Li, Qi

    2017-01-01

    A dual-axis reflective continuous-wave terahertz (THz) confocal scanning polarization imaging system was adopted. THz polarization imaging experiments on gaps on film and metallic letters "BeLLE" were carried out. Imaging results indicate that the THz polarization imaging is sensitive to the tilted gap or wide flat gap, suggesting the THz polarization imaging is able to detect edges and stains. An image fusion method based on the digital image processing was proposed to ameliorate the imaging quality of metallic letters "BeLLE." Objective and subjective evaluation both prove that this method can improve the imaging quality.

  5. An economic analysis comparison of stationary and dual-axis tracking grid-connected photovoltaic systems in the US Upper Midwest

    NASA Astrophysics Data System (ADS)

    Choi, Wongyu; Pate, Michael B.; Warren, Ryan D.; Nelson, Ron M.

    2018-05-01

    This paper presents an economic analysis of stationary and dual-axis tracking photovoltaic (PV) systems installed in the US Upper Midwest in terms of life-cycle costs, payback period, internal rate of return, and the incremental cost of solar energy. The first-year performance and energy savings were experimentally found along with documented initial cost. Future PV performance, savings, and operating and maintenance costs were estimated over 25-year assumed life. Under the given assumptions and discount rates, the life-cycle savings were found to be negative. Neither system was found to have payback periods less than the assumed system life. The lifetime average incremental costs of energy generated by the stationary and dual-axis tracking systems were estimated to be 0.31 and 0.37 per kWh generated, respectively. Economic analyses of different scenarios, each having a unique set of assumptions for costs and metering, showed a potential for economic feasibility under certain conditions when compared to alternative investments with assumed yields.

  6. Retuning the DARHT Axis-II Linear Induction Accelerator

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ekdahl, Carl August Jr.; Schulze, Martin E.; Carlson, Carl A.

    2015-03-31

    The Dual-Axis Radiographic Hydrodynamic Test (DARHT) facility uses bremsstrahlung radiation source spots produced by the focused electron beams from two linear induction accelerators (LIAs) to radiograph large hydrodynamic experiments driven by high explosives. The Axis-II 1.7-kA, 1600-ns beam pulse is transported through the LIA by the magnetic field from 91 solenoids as it is accelerated to ~16.5 MeV. The magnetic field produced by the solenoids and 80 steering dipole pairs for a given set of magnet currents is known as the “tune” of the accelerator [1]. From June, 2013 through September, 2014 a single tune was used. This tune wasmore » based on measurements of LIA element positions made over several years [2], and models of solenoidal fields derived from actual field measurements [3] [4]. Based on the focus scan technique, changing the tune of the accelerator and downstream transport had no effect on the beam emittance, to within the uncertainties of the measurement. Beam sizes appear to have been overestimated in all prior measurements because of the low magnification of the imaging system. This has resulted in overestimates of emittance by ~50%. The high magnification imaging should be repeated with the old tune for direct comparison with the new tune. High magnification imaging with the new accelerator tune should be repeated after retuning the downstream to produce a much more symmetric beam to reduce the uncertainty of this measurement. Thus, these results should be considered preliminary until we can effect a new tune to produce symmetric spots at our imaging station, for high magnification images.« less

  7. Relationship between the tibial mechanical axis and bony anatomical landmarks of the calf and foot as measured on radiographs obtained with a new laser-calibrated position.

    PubMed

    He, Peiheng; Zhu, Qi; Zhang, Zhaohui; Zou, Xuenong; Xu, Dongliang

    2013-01-01

    To investigate relationship between the tibial mechanical axis and bony landmarks of the calf and foot by developing a new laser-calibrated position for radiography of the lower limb. A total of 120 volunteers were randomly divided into two groups. All subjects were marked with skin projection of the hypothetical axis of the calf on the frontal and sagittal planes. Radiographs of weight-bearing full-length lower-limb were obtained by the laser-calibrated positioning in the experimental group, and by the use of conventional technique in the control group. To consider the rotation of the calf, radiological features of the knee and ankle were investigated. The relationship between the tibial mechanical axis and the bony landmarks of the calf and foot were also measured. Anteroposterior view depicted a tangential projection on the superior/inferior tibiofibular syndesmosis and between lateral malleolus and talus in ankle mortise in the experimental group. Bony overlap on the superior/inferior tibiofibular syndesmosis and between lateral malleolus and talus was seen in control group. On the tangential projection, it also presented a clear wheel-like contour of the medial femoral condyle, but a partial overlap between medial femoral condyle and tibial plateau. The femoral joint angle between the connecting line at the lowest point of the medial and lateral femoral condyles and the tibial mechanical axis was 83.6° ± 2.49° in the experimental group and 85.3° ± 2.18° in the control group (P < 0.001). The tibial tubercle-axis distance from the center of the medial and middle one-third of the tibial tubercle to the tibial mechanical axis was 1.5 mm in the experimental group and 3.7 mm in the control group (P < 0.05). The malleoli-axis distance from the midpoint of the bimalleolar line joining the tips of the medial and lateral malleoli to the tibial mechanical axis was 1.9 mm in the experimental group and 6.9 mm in the control group (P < 0.001). Lateral view showed no

  8. Miniature in vivo MEMS-based line-scanned dual-axis confocal microscope for point-of-care pathology

    PubMed Central

    Yin, C.; Glaser, A.K.; Leigh, S. Y.; Chen, Y.; Wei, L.; Pillai, P. C. S.; Rosenberg, M. C.; Abeytunge, S.; Peterson, G.; Glazowski, C.; Sanai, N.; Mandella, M. J.; Rajadhyaksha, M.; Liu, J. T. C.

    2016-01-01

    There is a need for miniature optical-sectioning microscopes to enable in vivo interrogation of tissues as a real-time and noninvasive alternative to gold-standard histopathology. Such devices could have a transformative impact for the early detection of cancer as well as for guiding tumor-resection procedures. Miniature confocal microscopes have been developed by various researchers and corporations to enable optical sectioning of highly scattering tissues, all of which have necessitated various trade-offs in size, speed, depth selectivity, field of view, resolution, image contrast, and sensitivity. In this study, a miniature line-scanned (LS) dual-axis confocal (DAC) microscope, with a 12-mm diameter distal tip, has been developed for clinical point-of-care pathology. The dual-axis architecture has demonstrated an advantage over the conventional single-axis confocal configuration for reducing background noise from out-of-focus and multiply scattered light. The use of line scanning enables fast frame rates (16 frames/sec is demonstrated here, but faster rates are possible), which mitigates motion artifacts of a hand-held device during clinical use. We have developed a method to actively align the illumination and collection beams in a DAC microscope through the use of a pair of rotatable alignment mirrors. Incorporation of a custom objective lens, with a small form factor for in vivo clinical use, enables our device to achieve an optical-sectioning thickness and lateral resolution of 2.0 and 1.1 microns respectively. Validation measurements with reflective targets, as well as in vivo and ex vivo images of tissues, demonstrate the clinical potential of this high-speed optical-sectioning microscopy device. PMID:26977337

  9. A three-axis force sensor for dual finger haptic interfaces.

    PubMed

    Fontana, Marco; Marcheschi, Simone; Salsedo, Fabio; Bergamasco, Massimo

    2012-10-10

    In this work we present the design process, the characterization and testing of a novel three-axis mechanical force sensor. This sensor is optimized for use in closed-loop force control of haptic devices with three degrees of freedom. In particular the sensor has been conceived for integration with a dual finger haptic interface that aims at simulating forces that occur during grasping and surface exploration. The sensing spring structure has been purposely designed in order to match force and layout specifications for the application. In this paper the design of the sensor is presented, starting from an analytic model that describes the characteristic matrix of the sensor. A procedure for designing an optimal overload protection mechanism is proposed. In the last part of the paper the authors describe the experimental characterization and the integrated test on a haptic hand exoskeleton showing the improvements in the controller performances provided by the inclusion of the force sensor.

  10. A Three-Axis Force Sensor for Dual Finger Haptic Interfaces

    PubMed Central

    Fontana, Marco; Marcheschi, Simone; Salsedo, Fabio; Bergamasco, Massimo

    2012-01-01

    In this work we present the design process, the characterization and testing of a novel three-axis mechanical force sensor. This sensor is optimized for use in closed-loop force control of haptic devices with three degrees of freedom. In particular the sensor has been conceived for integration with a dual finger haptic interface that aims at simulating forces that occur during grasping and surface exploration. The sensing spring structure has been purposely designed in order to match force and layout specifications for the application. In this paper the design of the sensor is presented, starting from an analytic model that describes the characteristic matrix of the sensor. A procedure for designing an optimal overload protection mechanism is proposed. In the last part of the paper the authors describe the experimental characterization and the integrated test on a haptic hand exoskeleton showing the improvements in the controller performances provided by the inclusion of the force sensor. PMID:23202012

  11. Development of a MEMS dual-axis differential capacitance floating element shear stress sensor

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Barnard, Casey; Griffin, Benjamin

    A single-axis MEMS wall shear stress sensor with differential capacitive transduction method is produced. Using a synchronous modulation and demodulation interface circuit, the system is capable of making real time measurements of both mean and fluctuating wall shear stress. A sensitivity of 3.44 mV/Pa is achieved, with linearity in response demonstrated up to testing limit of 2 Pa. Minimum detectable signals of 340 μPa at 100 Hz and 120 μPa at 1 kHz are indicated, with a resonance of 3.5 kHz. Multiple full scale wind tunnel tests are performed, producing spectral measurements of turbulent boundary layers in wind speeds rangingmore » up to 0.5 Ma (18 Pa of mean wall shear stress). The compact packaging allows for minimally invasive installation, and has proven relatively robust over multiple testing events. Temperature sensitivity, likely due to poor CTE matching of packaged materials, is an ongoing concern being addressed. These successes are being directly leveraged into a development plan for a dual-axis wall shear stress sensor, capable of producing true vector estimates at the wall.« less

  12. Tuning the DARHT Axis-II linear induction accelerator focusing

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ekdahl, Carl A.

    2012-04-24

    Flash radiography of large hydrodynamic experiments driven by high explosives is a well-known diagnostic technique in use at many laboratories, and the Dual-Axis Radiography for Hydrodynamic Testing (DARHT) facility at Los Alamos produces flash radiographs of large hydrodynamic experiments. Two linear induction accelerators (LIAs) make the bremsstrahlung radiographic source spots for orthogonal views of each test. The 2-kA, 20-MeV Axis-I LIA creates a single 60-ns radiography pulse. The 1.7-kA, 16.5-MeV Axis-II LIA creates up to four radiography pulses by kicking them out of a longer pulse that has a 1.6-{mu}s flattop. The Axis-II injector, LIA, kicker, and downstream transport (DST)more » to the bremsstrahlung converter are described. Adjusting the magnetic focusing and steering elements to optimize the electron-beam transport through an LIA is often called 'tuning.' As in all high-current LIAs, the focusing field is designed to be as close to that of the ideal continuous solenoid as physically possible. In ideal continuous solenoidal transport a smoothly varying beam size can easily be found for which radial forces balance, and the beam is said to be 'matched' to the focusing field. A 'mismatched' beam exhibits unwanted oscillations in size, which are a source of free energy that contributes to emittance growth. This is undesirable, because in the absence of beam-target effects, the radiographic spot size is proportional to the emittance. Tuning the Axis-II LIA is done in two steps. First, the solenoidal focusing elements are set to values designed to provide a matched beam with little or no envelope oscillations, and little or no beam-breakup (BBU) instability growth. Then, steering elements are adjusted to minimize the motion of the centroid of a well-centered beam at the LIA exit. This article only describes the design of the tune for the focusing solenoids. The DARHT Axis-II LIA was required to be re-tuned after installing an accelerator cell to replace a

  13. Dual-mesoporous ZSM-5 zeolite with highly b-axis-oriented large mesopore channels for the production of benzoin ethyl ether.

    PubMed

    Zhou, Xiaoxia; Chen, Hangrong; Zhu, Yan; Song, Yudian; Chen, Yu; Wang, Yongxia; Gong, Yun; Zhang, Guobin; Shu, Zhu; Cui, Xiangzhi; Zhao, Jinjin; Shi, Jianlin

    2013-07-22

    Dual-mesoporous ZSM-5 zeolite with highly b axis oriented large mesopores was synthesized by using nonionic copolymer F127 and cationic surfactant CTAB as co-templates. The product contains two types of mesopores--smaller wormlike ones of 3.3 nm in size and highly oriented larger ones of 30-50 nm in diameter along the b axis--and both of them interpenetrate throughout the zeolite crystals and interconnect with zeolite microporosity. The dual-mesoporous zeolite exhibits excellent catalytic performance in the condensation of benzaldehyde with ethanol and greater than 99 % selectivity for benzoin ethyl ether at room temperature, which can be ascribed to the zeolite lattice structure offering catalytically active sites and the hierarchical and oriented mesoporous structure providing fast access of reactants to these sites in the catalytic reaction. The excellent recyclability and high catalytic stability of the catalyst suggest prospective applications of such unique mesoporous zeolites in the chemical industry. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Construction of a dual axis force reflection stick and test station

    NASA Astrophysics Data System (ADS)

    Repperger, Daniel E.; Scarborough, Eric L.; Chelette, Tamara L.

    1991-11-01

    This report describes the construction of a dual axis force reflecting stick controller and test station which was constructed through the use of basic research funds (ILIR monies). The prototype described in this report is powered only by electric motors and used the latest technology in computers. This was an advancement over a previous prototype which involved pneumatic devices and was very large, bulky, and awkward to use. An experiment was conducted with 5 subjects as described herein to test the overall system for its use in experimental design. The motivation for developing such a small test station for the use of force reflection in stick controllers is because with this new compact and portable system, many new applications now appear for this technology. The system described herein minimizes both weight and electric power requirements to produce the same force reflection. By upgrading the technology in the components used in this test station, wider use of force reflection is now available for a host of new applications.

  15. Simple and robust resistive dual-axis accelerometer using a liquid metal droplet

    NASA Astrophysics Data System (ADS)

    Huh, Myoung; Won, Dong-Joon; Kim, Joong Gil; Kim, Joonwon

    2017-12-01

    This paper presents a novel dual-axis accelerometer that consists of a liquid metal droplet in a cone-shaped channel and an electrode layer with four Nichrome electrodes. The sensor uses the advantages of the liquid metal droplet (i.e., high surface tension, electrical conductivity, high density, and deformability). The cone-shaped channel imposes a restoring force on the liquid metal droplet. We conducted simulation tests to determine the appropriate design specifications of the cone-shaped channel. Surface modifications to the channel enhanced the nonwetting performance of the liquid metal droplet. The performances of the sensor were analyzed by a tilting test. When the acceleration was applied along the axial direction, the device showed 6 kΩ/g of sensitivity and negligible crosstalk between the X- and Y-axes. In a diagonal direction test, the device showed 4 kΩ/g of sensitivity.

  16. Small animal bone density and morphometry analysis with a dual energy x-ray absorptiometry bone densitometer using a 2D digital radiographic detector

    NASA Astrophysics Data System (ADS)

    Boudousq, V.; Bordy, T.; Gonon, G.; Dinten, J. M.

    2005-04-01

    The LEXXOS (DMS, Montpellier, France) is the first axial and total body cone beam bone densitometer using a 2D digital radiographic detector. Technical principles and performances for BMD measurements have been presented in previous papers. Bone densitometers are also used on small animals for drug development. In this paper, we show how the LEXXOS system can be adapted to small animals examinations, and its performances are evaluated. At first, in order to take advantage of the whole area of the digital flat panel X-ray detector, the geometrical configuration has been adapted. Secondly, as small animals present low BMD, a specific dual energy calibration has been defined. This adapted system has then been evaluated on two sets of mice: six reference mice and six ovariectomized mice. Each month, these two populations have been examined and the total body BMD has been measured. This evaluation has shown that the right order of BMD magnitude has been obtained and, as expected, BMD increases on the two sets until age of puberty and after this period, decreases significantly for the ovariectomized set. Moreover, the bone image obtained by dual energy processing on LEXXOS presents a radiographic image quality providing with useful complementary information on bone morphometry and architecture.

  17. Diode magnetic-field influence on radiographic spot size

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ekdahl, Carl A. Jr.

    2012-09-04

    Flash radiography of hydrodynamic experiments driven by high explosives is a well-known diagnostic technique in use at many laboratories. The Dual-Axis Radiography for Hydrodynamic Testing (DARHT) facility at Los Alamos was developed for flash radiography of large hydrodynamic experiments. Two linear induction accelerators (LIAs) produce the bremsstrahlung radiographic source spots for orthogonal views of each experiment ('hydrotest'). The 2-kA, 20-MeV Axis-I LIA creates a single 60-ns radiography pulse. For time resolution of the hydrotest dynamics, the 1.7-kA, 16.5-MeV Axis-II LIA creates up to four radiography pulses by slicing them out of a longer pulse that has a 1.6-{micro}s flattop. Bothmore » axes now routinely produce radiographic source spot sizes having full-width at half-maximum (FWHM) less than 1 mm. To further improve on the radiographic resolution, one must consider the major factors influencing the spot size: (1) Beam convergence at the final focus; (2) Beam emittance; (3) Beam canonical angular momentum; (4) Beam-motion blur; and (5) Beam-target interactions. Beam emittance growth and motion in the accelerators have been addressed by careful tuning. Defocusing by beam-target interactions has been minimized through tuning of the final focus solenoid for optimum convergence and other means. Finally, the beam canonical angular momentum is minimized by using a 'shielded source' of electrons. An ideal shielded source creates the beam in a region where the axial magnetic field is zero, thus the canonical momentum zero, since the beam is born with no mechanical angular momentum. It then follows from Busch's conservation theorem that the canonical angular momentum is minimized at the target, at least in principal. In the DARHT accelerators, the axial magnetic field at the cathode is minmized by using a 'bucking coil' solenoid with reverse polarity to cancel out whatever solenoidal beam transport field exists there. This is imperfect in practice, because

  18. Dual-axis vapor cell for simultaneous laser frequency stabilization on disparate optical transitions

    NASA Astrophysics Data System (ADS)

    Jayakumar, Anupriya; Plotkin-Swing, Benjamin; Jamison, Alan O.; Gupta, Subhadeep

    2015-07-01

    We have developed a dual-axis ytterbium (Yb) vapor cell and used it to simultaneously address the two laser cooling transitions in Yb at wavelengths 399 nm and 556 nm, featuring the disparate linewidths of 2π × 29 MHz and 2π × 182 KHz, respectively. By utilizing different optical paths for the two wavelengths, we simultaneously obtain comparable optical densities suitable for saturated absorption spectroscopy for both the transitions and keep both the lasers frequency stabilized over several hours. We demonstrate that by appropriate control of the cell temperature profile, two atomic transitions differing in relative strength across a large range of over three orders of magnitude can be simultaneously addressed, making the device adaptable to a variety of spectroscopic needs. We also show that our observations can be understood with a simple theoretical model of the Yb vapor.

  19. Attitude Heading Reference System Using MEMS Inertial Sensors with Dual-Axis Rotation

    PubMed Central

    Kang, Li; Ye, Lingyun; Song, Kaichen; Zhou, Yang

    2014-01-01

    This paper proposes a low cost and small size attitude and heading reference system based on MEMS inertial sensors. A dual-axis rotation structure with a proper rotary scheme according to the design principles is applied in the system to compensate for the attitude and heading drift caused by the large gyroscope biases. An optimization algorithm is applied to compensate for the installation angle error between the body frame and the rotation table's frame. Simulations and experiments are carried out to evaluate the performance of the AHRS. The results show that the proper rotation could significantly reduce the attitude and heading drifts. Moreover, the new AHRS is not affected by magnetic interference. After the rotation, the attitude and heading are almost just oscillating in a range. The attitude error is about 3° and the heading error is less than 3° which are at least 5 times better than the non-rotation condition. PMID:25268911

  20. A handheld MEMS-based line-scanned dual-axis confocal microscope for early cancer detection and surgical guidance (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Chen, Ye; Yin, Chengbo; Wei, Linpeng; Glaser, Adam K.; Abeytunge, Sanjee; Peterson, Gary; Mandella, Michael J.; Sanai, Nader; Rajadhyaksha, Milind; Liu, Jonathan T.

    2017-02-01

    Considerable efforts have been recently undertaken to develop miniature optical-sectioning microscopes for in vivo microendoscopy and point-of-care pathology. These devices enable in vivo interrogation of disease as a real-time and noninvasive alternative to gold-standard histopathology, and therefore could have a transformative impact for the early detection of cancer as well as for guiding tumor-resection procedures. Regardless of the specific modality, various trade-offs in size, speed, field of view, resolution, contrast, and sensitivity are necessary to optimize a device for a particular application. Here, a miniature MEMS-based line-scanned dual-axis confocal (LS-DAC) microscope, with a 12-mm diameter distal tip, has been developed for point-of-care pathology. The dual-axis architecture has demonstrated superior rejection of out-of-focus and multiply scattered photons compared to a conventional single-axis confocal configuration. The use of line scanning enables fast frame rates (≥15 frames/sec), which mitigates motion artifacts of a handheld device during clinical use. We have developed a method to actively align the illumination and collection beams in this miniature LS-DAC microscope through the use of a pair of rotatable alignment mirrors. Incorporation of a custom objective lens, with a small form factor for in vivo application, enables the device to achieve an axial and lateral resolution of 2.0 and 1.1 microns, respectively. Validation measurements with reflective targets, as well as in vivo and ex vivo images of tissues, demonstrate that this high-speed LS-DAC microscope can achieve high-contrast imaging of fluorescently labeled tissues with sufficient sensitivity for applications such as oral cancer detection and guiding brain-tumor resections.

  1. BBU and Corkscrew Growth Predictions for the Darht Second Axis Accelerator

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chen, Y.J.; Fawley, W.M.

    2001-06-12

    The second axis accelerator of the Dual Axis Radiographic Hydrodynamic Test (DARHT-II) facility will produce a 2-kA, 20-MeV, 2-{micro}s output electron beam with a design goal of less than 1000 {pi} mm-mrad normalized transverse emittance. In order to meet this goal, both the beam breakup instability (BBJ) and transverse corkscrew motion (due to chromatic phase advance) must be limited in growth. Using data from recent experimental measurements of the transverse impedance of actual DARHT-II accelerator cells by Briggs et al. [2], they have used the LLNL BREAKUP code to predict BBU and corkscrew growth in DARHT-II. The results suggest thatmore » BBU growth should not seriously degrade the final achievable spot size at the x-ray converter, presuming the initial excitation level is of the order 100 microns or smaller. For control of corkscrew growth, a major concern is the number of tuning shots needed to utilize effectively the tuning-V algorithm [3]. Presuming that the solenoid magnet alignment falls within spec, they believe that possibly as few as 50-100 shots will be necessary to set the dipole corrector magnet currents. They give some specific examples of tune determination for a hypothetical set of alignment errors.« less

  2. BBU and Corkscrew Growth Predictions for the DARHT Second Axis Accelerator

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chen, Y J; Fawley, W M

    2001-06-12

    The second axis accelerator of the Dual Axis Radiographic Hydrodynamic Test (DARHT-II) facility will produce a 2-kA, 20-MeV, 2-{micro}s output electron beam with a design goal of less than 1000 {pi} mm-mrad normalized transverse emittance. In order to meet this goal, both the beam breakup instability (BBU) and transverse ''corkscrew'' motion (due to chromatic phase advance) must be limited in growth. Using data from recent experimental measurements of the transverse impedance of actual DARHT-II accelerator cells by Briggs et al., they have used the LLNL BREAKUP code to predict BBU and corkscrew growth in DARHT-II. The results suggest that BBUmore » growth should not seriously degrade the final achievable spot size at the x-ray converter, presuming the initial excitation level is of the order 100 microns or smaller. For control of corkscrew growth, a major concern is the number of ''tuning'' shots needed to utilize effectively the ''tuning-V'' algorithm. Presuming that the solenoid magnet alignment falls within spec, they believe that possibly as few as 50-100 shots will be necessary to set the dipole corrector magnet currents. They give some specific examples of tune determination for a hypothetical set of alignment errors.« less

  3. Optimizing the performance of dual-axis confocal microscopes via Monte-Carlo scattering simulations and diffraction theory.

    PubMed

    Chen, Ye; Liu, Jonathan T C

    2013-06-01

    Dual-axis confocal (DAC) microscopy has been found to exhibit superior rejection of out-of-focus and multiply scattered background light compared to conventional single-axis confocal microscopy. DAC microscopes rely on the use of separated illumination and collection beam paths that focus and intersect at a single focal volume (voxel) within tissue. While it is generally recognized that the resolution and contrast of a DAC microscope depends on both the crossing angle of the DAC beams, 2θ, and the focusing numerical aperture of the individual beams, α, a detailed study to investigate these dependencies has not been performed. Contrast and resolution are considered as two main criteria to assess the performance of a point-scanned DAC microscope (DAC-PS) and a line-scanned DAC microscope (DAC-LS) as a function of θ and α. The contrast and resolution of these designs are evaluated by Monte-Carlo scattering simulations and diffraction theory calculations, respectively. These results can be used for guiding the optimal designs of DAC-PS and DAC-LS microscopes.

  4. Soft X-ray spectrometer design for warm dense plasma measurements on DARHT Axis-I

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ramey, Nicholas Bryan; Perry, John Oliver; Coleman, Joshua Eugene

    2017-07-11

    A preliminary design study is being performed on a soft X-ray spectrometer to measure K-shell spectra emitted by a warm dense plasma generated on Axis-I of the Dual-Axis Radiographic Hydrodynamic Testing (DARHT) facility at Los Alamos National Laboratory. The 100-ns-long intense, relativistic electron pulse with a beam current of 1.7 kA and energy of 19.8 MeV deposits energy into a thin metal foil heating it to a warm dense plasma. The collisional ionization of the target by the electron beam produces an anisotropic angular distribution of K-shell radiation and a continuum of both scattered electrons and Bremsstrahlung up to themore » beam energy of 19.8 MeV. The principal goal of this project is to characterize these angular distributions to determine the optimal location to deploy the soft X-ray spectrometer. In addition, a proof-of-principle design will be presented. The ultimate goal of the spectrometer is to obtain measurements of the plasma temperature and density to benchmark equation-of-state models of the warm dense matter regime.« less

  5. A dual-loop model of the human controller in single-axis tracking tasks

    NASA Technical Reports Server (NTRS)

    Hess, R. A.

    1977-01-01

    A dual loop model of the human controller in single axis compensatory tracking tasks is introduced. This model possesses an inner-loop closure which involves feeding back that portion of the controlled element output rate which is due to control activity. The sensory inputs to the human controller are assumed to be system error and control force. The former is assumed to be sensed via visual, aural, or tactile displays while the latter is assumed to be sensed in kinesthetic fashion. A nonlinear form of the model is briefly discussed. This model is then linearized and parameterized. A set of general adaptive characteristics for the parameterized model is hypothesized. These characteristics describe the manner in which the parameters in the linearized model will vary with such things as display quality. It is demonstrated that the parameterized model can produce controller describing functions which closely approximate those measured in laboratory tracking tasks for a wide variety of controlled elements.

  6. Problems Encountered During the Recertification of the GLORY Solar Array Dual Axis Gimbal Drive Actuators

    NASA Technical Reports Server (NTRS)

    Saltzman, Marc; Schepis, Jospeh P.; Bruckner, Michael J.

    2009-01-01

    The Glory observatory is the current incarnation of the Vegetation Canopy Lidar (VCL) mission spacecraft bus. The VCL spacecraft bus, having been cancelled for programmatic reasons in 2000, was nearly integrated when it was put into storage for possible future use. The Glory mission was a suitable candidate for using this spacecraft and in 2006 an effort to recertify the two axis solar array gimbal drive after its extended storage was begun. What was expected to be a simple performance validation of the two dual axis gimbal stepper motors became a serious test, diagnosis and repair task once questions arose on the flight worthiness of the hardware. A significant test program logic flow was developed which identified decisions that could be made based on the results of individual recertification tests. Without disassembling the bi-axial gimbals, beginning with stepper motor threshold voltage measurements and relating these to powered drive torque measurements, both performed at the spacecraft integrator s facility, a confusing picture of the health of the actuators came to light. Tests at the gimbal assembly level and tests of the disassembled actuators were performed by the manufacturer to validate our results and torque discrepancies were noted. Further disassembly to the component level of the actuator revealed the source of the torque loss.

  7. Comparison of dual and single exposure techniques in dual-energy chest radiography.

    PubMed

    Ho, J T; Kruger, R A; Sorenson, J A

    1989-01-01

    Conventional chest radiography is the most effective tool for lung cancer detection and diagnosis; nevertheless, a high percentage of lung cancer tumors are missed because of the overlap of lung nodule image contrast with bone image contrast in a chest radiograph. Two different energy subtraction strategies, dual exposure and single exposure techniques, were studied for decomposing a radiograph into bone-free and soft tissue-free images to address this problem. For comparing the efficiency of these two techniques in lung nodule detection, the performances of the techniques were evaluated on the basis of residual tissue contrast, energy separation, and signal-to-noise ratio. The evaluation was based on both computer simulation and experimental verification. The dual exposure technique was found to be better than the single exposure technique because of its higher signal-to-noise ratio and greater residual tissue contrast. However, x-ray tube loading and patient motion are problems.

  8. Can the tibial slope be measured on lateral knee radiographs?

    PubMed

    Faschingbauer, M; Sgroi, M; Juchems, M; Reichel, H; Kappe, T

    2014-12-01

    The posterior tibial slope influences both the natural knee stability as well as the stability and kinematics after total knee arthroplasty (TKA). Exact definition of the posterior tibial slope (PTS) requires lateral radiographs of the lower limb. Only lateral knee radiographs are routinely obtained after TKA, however. The purpose of the present study therefore was to analyse the relationship between PTS measurement results on short and expanded lateral knee radiographs. The PTS was measured on 100 consecutive lateral radiographs of the lower limb using the mechanical and three diaphyseal axes with various distances below the tibial plateau. Significant differences between PTS results were found for all three diaphyseal axes, with the smallest differences and the strongest correlation for a diaphyseal axis at 16 and 20 cm below the tibial plateau. Using short distances below the tibial plateau (6 and 10 cm) resulted in an overestimation of the PTS of 3°, on average. The PTS measurements in long lateral knee radiographs are more accurate compared to short radiographs. On short lateral knee radiographs, only a estimation of the PTS can be carried out. Diagnostic study, Level II.

  9. Fracture strength of four different types of anterior 3-unit bridges after thermo-mechanical fatigue in the dual-axis chewing simulator.

    PubMed

    Kheradmandan, S; Koutayas, S O; Bernhard, M; Strub, J R

    2001-04-01

    The purpose of this study was to evaluate the fracture strength of four different types of anterior 3-unit bridges after thermo-mechanical fatigue in a dual-axis chewing simulator. Sixty-four human maxillary incisors were prepared and 32 bridges fabricated. The four groups of eight bridges each were - (GC): AGC(R) galvano-ceramic bridges (CA): Celay(R) In-Ceram(R) Alumina bridges (E2): heat-pressed lithium disilicate glass-ceramic bridges and (CM) ceramo-metal (control). Fracture loads were recorded after a dual-axis chewing simulator and in a universal testing machine. The survival rate after 5 years for the CM and the GC groups was 100%, for the E2 group 75% and for the CA group 37.5% (Kaplan-Mayer analysis). The mean fracture strengths (N) were 681.52 +/- 151.90 (CM); 397.71 +/- 59.02 (GC); 292.92 +/- 46.45 (E2) and 239.95 +/- 33.39 (CA), respectively. The log-rank test showed a significant difference between the CA and the GC or the CA and the CM groups. No significant differences between the E2 and the CA or the E2 and the GC groups were found. The study indicates that heat-pressed lithium disilicate glass-ceramic and AGC(R) galvano-ceramic bridges are alternatives to ceramo-metal 3-unit anterior bridges.

  10. The interleukin-20 receptor axis in early rheumatoid arthritis: novel links between disease-associated autoantibodies and radiographic progression.

    PubMed

    Kragstrup, Tue Wenzel; Greisen, Stinne Ravn; Nielsen, Morten Aagaard; Rhodes, Christopher; Stengaard-Pedersen, Kristian; Hetland, Merete Lund; Hørslev-Petersen, Kim; Junker, Peter; Østergaard, Mikkel; Hvid, Malene; Vorup-Jensen, Thomas; Robinson, William H; Sokolove, Jeremy; Deleuran, Bent

    2016-03-11

    months (Spearman's rho = 0.19 and 0.26, both P < 0.05) in the early RA patients. The IL-22R1 was expressed by osteoclast precursors and in multinucleated osteoclasts. IL-20 and IL-24 increased the secretion of monocyte chemoattractant protein 1 by these cells. This study suggests that IL-20 and IL-24 link RA-associated autoantibodies with radiographic progression via the IL-22R1. Modulation of this axis holds promise as feasible anti-erosive treatment modalities in seropositive RA.

  11. Wavelength-tunable Hermite-Gaussian modes and an orbital-angular-momentum-tunable vortex beam in a dual-off-axis pumped Yb:CALGO laser.

    PubMed

    Shen, Yijie; Meng, Yuan; Fu, Xing; Gong, Mali

    2018-01-15

    A dual-off-axis pumping scheme is presented to generate wavelength-tunable high-order Hermite-Gaussian (HG) modes in Yb:CaGdAlO 4 lasers. The mode and wavelength can be actively controlled by the off-axis displacements and pump power. The purities of the output HG modes are quantified by intensity distributions and the measured M 2 values. The highest order reaches m=15 for stable HG m,0 mode, and wavelength-tunable width is about 10 nm. Moreover, through externally converting the HG m,0 modes, the vortex beams carrying orbital angular momentum (OAM) with a large OAM-tunable range from ±1ℏ to ±15ℏ are produced. This work is effective for largely scaling the spectral and OAM tunable ranges of optical vortex beams.

  12. In vivo near-infrared dual-axis confocal microendoscopy in the human lower gastrointestinal tract

    NASA Astrophysics Data System (ADS)

    Piyawattanametha, Wibool; Ra, Hyejun; Qiu, Zhen; Friedland, Shai; Liu, Jonathan T. C.; Loewke, Kevin; Kino, Gordon S.; Solgaard, Olav; Wang, Thomas D.; Mandella, Michael J.; Contag, Christopher H.

    2012-02-01

    Near-infrared confocal microendoscopy is a promising technique for deep in vivo imaging of tissues and can generate high-resolution cross-sectional images at the micron-scale. We demonstrate the use of a dual-axis confocal (DAC) near-infrared fluorescence microendoscope with a 5.5-mm outer diameter for obtaining clinical images of human colorectal mucosa. High-speed two-dimensional en face scanning was achieved through a microelectromechanical systems (MEMS) scanner while a micromotor was used for adjusting the axial focus. In vivo images of human patients are collected at 5 frames/sec with a field of view of 362×212 μm2 and a maximum imaging depth of 140 μm. During routine endoscopy, indocyanine green (ICG) was topically applied a nonspecific optical contrasting agent to regions of the human colon. The DAC microendoscope was then used to obtain microanatomic images of the mucosa by detecting near-infrared fluorescence from ICG. These results suggest that DAC microendoscopy may have utility for visualizing the anatomical and, perhaps, functional changes associated with colorectal pathology for the early detection of colorectal cancer.

  13. In vivo near-infrared dual-axis confocal microendoscopy in the human lower gastrointestinal tract.

    PubMed

    Piyawattanametha, Wibool; Ra, Hyejun; Qiu, Zhen; Friedland, Shai; Liu, Jonathan T C; Loewke, Kevin; Kino, Gordon S; Solgaard, Olav; Wang, Thomas D; Mandella, Michael J; Contag, Christopher H

    2012-02-01

    Near-infrared confocal microendoscopy is a promising technique for deep in vivo imaging of tissues and can generate high-resolution cross-sectional images at the micron-scale. We demonstrate the use of a dual-axis confocal (DAC) near-infrared fluorescence microendoscope with a 5.5-mm outer diameter for obtaining clinical images of human colorectal mucosa. High-speed two-dimensional en face scanning was achieved through a microelectromechanical systems (MEMS) scanner while a micromotor was used for adjusting the axial focus. In vivo images of human patients are collected at 5 frames/sec with a field of view of 362×212 μm(2) and a maximum imaging depth of 140 μm. During routine endoscopy, indocyanine green (ICG) was topically applied a nonspecific optical contrasting agent to regions of the human colon. The DAC microendoscope was then used to obtain microanatomic images of the mucosa by detecting near-infrared fluorescence from ICG. These results suggest that DAC microendoscopy may have utility for visualizing the anatomical and, perhaps, functional changes associated with colorectal pathology for the early detection of colorectal cancer.

  14. Dual Pathology of Mandible

    PubMed Central

    Rajurkar, Suday G.; Deshpande, Mohan D.; Kazi, Noaman; Jadhav, Dhanashree; Ranadive, Pallavi; Ingole, Snehal

    2017-01-01

    Aneurysmal Bone cyst (ABC)is a rare benign lesion of the bone which is infrequent in craniofacial region (12%). Rapid growth pattern causing bone expansion and facial asymmetry is a characteristic feature of ABC. Giant cell lesion is another distinct pathological entity. Here we present to you a rare case of dual pathology in an 11 year old female patient who presented with a large expansile lesion in the left hemimandible. All radiographic investigations were suggestive of ABC, aspiration of the lesion resulted in blood aspirate. However only after a histologic examination the dual nature of the lesion was revealed. PMID:29264307

  15. Dual Pathology of Mandible.

    PubMed

    Rajurkar, Suday G; Deshpande, Mohan D; Kazi, Noaman; Jadhav, Dhanashree; Ranadive, Pallavi; Ingole, Snehal

    2017-01-01

    Aneurysmal Bone cyst (ABC)is a rare benign lesion of the bone which is infrequent in craniofacial region (12%). Rapid growth pattern causing bone expansion and facial asymmetry is a characteristic feature of ABC. Giant cell lesion is another distinct pathological entity. Here we present to you a rare case of dual pathology in an 11 year old female patient who presented with a large expansile lesion in the left hemimandible. All radiographic investigations were suggestive of ABC, aspiration of the lesion resulted in blood aspirate. However only after a histologic examination the dual nature of the lesion was revealed.

  16. Dual regulation of HMGB1 by combined JNK1/2-ATF2 axis with miR-200 family in nonalcoholic steatohepatitis in mice.

    PubMed

    Chen, Xin; Ling, Yan; Wei, Yanping; Tang, Jing; Ren, Yibing; Zhang, Baohua; Jiang, Feng; Li, Hengyu; Wang, Ruoyu; Wen, Wen; Lv, Guishuai; Wu, Mengchao; Chen, Lei; Li, Liang; Wang, Hongyang

    2018-05-01

    In the context of diabetes, obesity, and metabolic syndrome, the inflammatory signaling has critical roles in the pathogenesis of nonalcoholic fatty liver disease (NAFLD), but the underlying mechanisms remain poorly delineated. Herein, early and persistently elevated, proinflammatory cytokine HMGB1 expression was detected in a high-fat diet (HFD)-induced NAFLD model in C57BL/6 mice. The expression and extracellular release of HMGB1 was rapidly and dramatically induced by saturated palmitic acid in vitro. HFD-induced inflammatory response and liver function impairment were both mitigated after the inhibition of endogenous HMGB1 by neutralizing antibody in vivo. The up-regulation of HMGB1 was thought to be modified by dual channels: in the transcriptional level, it was regulated by JNK1/JNK2-ATF2 axis; post-transcriptionally, it was regulated by the microRNA (miR)-200 family, especially miR-429. miR-429 liver conditional knockout mice (miR-429 Δhep ), fed either a normal diet or an HFD, showed severe liver inflammation and dysfunction, accompanied by greater expression of HMGB1. Intriguingly, the up-regulation and release of HMGB1 could in turn self-activate TLR4-JNK1/JNK2-ATF2 signaling, thus forming a positive feedback. Our findings reveal a novel mechanism by which HMGB1 expression was regulated by both the JNK1/2-ATF2 axis and the miR-200 family, which provides a potential new approach for the treatment of NAFLD.-Chen, X., Ling, Y., Wei, Y., Tang, J., Ren, Y., Zhang, B., Jiang, F., Li, H., Wang, R., Wen, W., Lv, G., Wu, M., Chen, L., Li, L., Wang, H. Dual regulation of HMGB1 by combined JNK1/2-ATF2 axis with miR-200 family in nonalcoholic steatohepatitis in mice.

  17. New View on the Initial Development Site and Radiographic Classification System of Osteoarthritis of the Knee Based on Radiographic Analysis

    PubMed Central

    Moon, Ki-Ho

    2012-01-01

    Introduction: Radiographic pathology of severe osteoarthritis of the knee (OAK) such as severe osteophyte at tibial spine (TS), compartment narrowing, marginal osteophyte, and subchondral sclerosis is well known. Kellgren-Lawrence grading system, which is widely used to diagnose OAK, describes narrowing-marginal osteophyte in 4-grades but uses osteophyte at TS only as evidence of OAK without detailed-grading. However, kinematically the knee employs medial TS as an axis while medial and lateral compartments carry the load, suggesting that early OAK would occur sooner at TS than at compartment. Then, Kellgren-Lawrence system may be inadequate to diagnose early-stage OAK manifested as a subtle osteophyte at TS without narrowing-marginal osteophyte. This undiagnosed-OAK will deteriorate becoming a contributing factor in an increasing incidence of OAK. Methods: This study developed a radiographic OAK-marker based on both osteophyte at TS and compartment narrowing-marginal osteophyte and graded as normal, mild, moderate, and severe. With this marker, both knee radiographs of 1,728 patients with knee pain were analyzed. Results: Among 611 early-stage mild OAK, 562 or 92% started at TS and 49 or 8% at compartment. It suggests the initial development site of OAK, helping develop new site-specific radiographic classification system of OAK accurately to diagnose all severity of OAK at early, intermediate, or late-stage. It showed that Kellgren-Lawrence system missed 92.0% of early-stage mild OAK from diagnosis. Conclusions: A subtle osteophyte at TS is the earliest radiographic sign of OAK. A new radiographic classification system of OAK was suggested for accurate diagnosis of all OAK in severity and at stage. PMID:23675278

  18. New view on the initial development site and radiographic classification system of osteoarthritis of the knee based on radiographic analysis.

    PubMed

    Moon, Ki-Ho

    2012-12-01

    Radiographic pathology of severe osteoarthritis of the knee (OAK) such as severe osteophyte at tibial spine (TS), compartment narrowing, marginal osteophyte, and subchondral sclerosis is well known. Kellgren-Lawrence grading system, which is widely used to diagnose OAK, describes narrowing-marginal osteophyte in 4-grades but uses osteophyte at TS only as evidence of OAK without detailed-grading. However, kinematically the knee employs medial TS as an axis while medial and lateral compartments carry the load, suggesting that early OAK would occur sooner at TS than at compartment. Then, Kellgren-Lawrence system may be inadequate to diagnose early-stage OAK manifested as a subtle osteophyte at TS without narrowing-marginal osteophyte. This undiagnosed-OAK will deteriorate becoming a contributing factor in an increasing incidence of OAK. This study developed a radiographic OAK-marker based on both osteophyte at TS and compartment narrowing-marginal osteophyte and graded as normal, mild, moderate, and severe. With this marker, both knee radiographs of 1,728 patients with knee pain were analyzed. Among 611 early-stage mild OAK, 562 or 92% started at TS and 49 or 8% at compartment. It suggests the initial development site of OAK, helping develop new site-specific radiographic classification system of OAK accurately to diagnose all severity of OAK at early, intermediate, or late-stage. It showed that Kellgren-Lawrence system missed 92.0% of early-stage mild OAK from diagnosis. A subtle osteophyte at TS is the earliest radiographic sign of OAK. A new radiographic classification system of OAK was suggested for accurate diagnosis of all OAK in severity and at stage.

  19. In vivo near-infrared dual-axis confocal microendoscopy in the human lower gastrointestinal tract

    PubMed Central

    Ra, Hyejun; Qiu, Zhen; Friedland, Shai; Liu, Jonathan T. C.; Loewke, Kevin; Kino, Gordon S.; Solgaard, Olav; Wang, Thomas D.; Mandella, Michael J.; Contag, Christopher H.

    2012-01-01

    Abstract. Near-infrared confocal microendoscopy is a promising technique for deep in vivo imaging of tissues and can generate high-resolution cross-sectional images at the micron-scale. We demonstrate the use of a dual-axis confocal (DAC) near-infrared fluorescence microendoscope with a 5.5-mm outer diameter for obtaining clinical images of human colorectal mucosa. High-speed two-dimensional en face scanning was achieved through a microelectromechanical systems (MEMS) scanner while a micromotor was used for adjusting the axial focus. In vivo images of human patients are collected at 5  frames/sec with a field of view of 362×212  μm2 and a maximum imaging depth of 140 μm. During routine endoscopy, indocyanine green (ICG) was topically applied a nonspecific optical contrasting agent to regions of the human colon. The DAC microendoscope was then used to obtain microanatomic images of the mucosa by detecting near-infrared fluorescence from ICG. These results suggest that DAC microendoscopy may have utility for visualizing the anatomical and, perhaps, functional changes associated with colorectal pathology for the early detection of colorectal cancer. PMID:22463020

  20. The Nature of Scatter at the DARHT Facility and Suggestions for Improved Modeling of DARHT Facility

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Morneau, Rachel Anne

    This report describes the US Stockpile Stewardship Program which is meant to sustain and evaluate nuclear weapon stockpile with no underground nuclear tests. This research will focus on DARHT, the Dual Axis Radiographic Hydrodynamic Test facility.

  1. Using dual-energy x-ray imaging to enhance automated lung tumor tracking during real-time adaptive radiotherapy.

    PubMed

    Menten, Martin J; Fast, Martin F; Nill, Simeon; Oelfke, Uwe

    2015-12-01

    Real-time, markerless localization of lung tumors with kV imaging is often inhibited by ribs obscuring the tumor and poor soft-tissue contrast. This study investigates the use of dual-energy imaging, which can generate radiographs with reduced bone visibility, to enhance automated lung tumor tracking for real-time adaptive radiotherapy. kV images of an anthropomorphic breathing chest phantom were experimentally acquired and radiographs of actual lung cancer patients were Monte-Carlo-simulated at three imaging settings: low-energy (70 kVp, 1.5 mAs), high-energy (140 kVp, 2.5 mAs, 1 mm additional tin filtration), and clinical (120 kVp, 0.25 mAs). Regular dual-energy images were calculated by weighted logarithmic subtraction of high- and low-energy images and filter-free dual-energy images were generated from clinical and low-energy radiographs. The weighting factor to calculate the dual-energy images was determined by means of a novel objective score. The usefulness of dual-energy imaging for real-time tracking with an automated template matching algorithm was investigated. Regular dual-energy imaging was able to increase tracking accuracy in left-right images of the anthropomorphic phantom as well as in 7 out of 24 investigated patient cases. Tracking accuracy remained comparable in three cases and decreased in five cases. Filter-free dual-energy imaging was only able to increase accuracy in 2 out of 24 cases. In four cases no change in accuracy was observed and tracking accuracy worsened in nine cases. In 9 out of 24 cases, it was not possible to define a tracking template due to poor soft-tissue contrast regardless of input images. The mean localization errors using clinical, regular dual-energy, and filter-free dual-energy radiographs were 3.85, 3.32, and 5.24 mm, respectively. Tracking success was dependent on tumor position, tumor size, imaging beam angle, and patient size. This study has highlighted the influence of patient anatomy on the success rate of real

  2. Using dual-energy x-ray imaging to enhance automated lung tumor tracking during real-time adaptive radiotherapy

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Menten, Martin J., E-mail: martin.menten@icr.ac.uk; Fast, Martin F.; Nill, Simeon

    2015-12-15

    Purpose: Real-time, markerless localization of lung tumors with kV imaging is often inhibited by ribs obscuring the tumor and poor soft-tissue contrast. This study investigates the use of dual-energy imaging, which can generate radiographs with reduced bone visibility, to enhance automated lung tumor tracking for real-time adaptive radiotherapy. Methods: kV images of an anthropomorphic breathing chest phantom were experimentally acquired and radiographs of actual lung cancer patients were Monte-Carlo-simulated at three imaging settings: low-energy (70 kVp, 1.5 mAs), high-energy (140 kVp, 2.5 mAs, 1 mm additional tin filtration), and clinical (120 kVp, 0.25 mAs). Regular dual-energy images were calculated bymore » weighted logarithmic subtraction of high- and low-energy images and filter-free dual-energy images were generated from clinical and low-energy radiographs. The weighting factor to calculate the dual-energy images was determined by means of a novel objective score. The usefulness of dual-energy imaging for real-time tracking with an automated template matching algorithm was investigated. Results: Regular dual-energy imaging was able to increase tracking accuracy in left–right images of the anthropomorphic phantom as well as in 7 out of 24 investigated patient cases. Tracking accuracy remained comparable in three cases and decreased in five cases. Filter-free dual-energy imaging was only able to increase accuracy in 2 out of 24 cases. In four cases no change in accuracy was observed and tracking accuracy worsened in nine cases. In 9 out of 24 cases, it was not possible to define a tracking template due to poor soft-tissue contrast regardless of input images. The mean localization errors using clinical, regular dual-energy, and filter-free dual-energy radiographs were 3.85, 3.32, and 5.24 mm, respectively. Tracking success was dependent on tumor position, tumor size, imaging beam angle, and patient size. Conclusions: This study has highlighted the

  3. An additional reference axis improves femoral rotation alignment in image-free computer navigation assisted total knee arthroplasty.

    PubMed

    Inui, Hiroshi; Taketomi, Shuji; Nakamura, Kensuke; Sanada, Takaki; Tanaka, Sakae; Nakagawa, Takumi

    2013-05-01

    Few studies have demonstrated improvement in accuracy of rotational alignment using image-free navigation systems mainly due to the inconsistent registration of anatomical landmarks. We have used an image-free navigation for total knee arthroplasty, which adopts the average algorithm between two reference axes (transepicondylar axis and axis perpendicular to the Whiteside axis) for femoral component rotation control. We hypothesized that addition of another axis (condylar twisting axis measured on a preoperative radiograph) would improve the accuracy. One group using the average algorithm (double-axis group) was compared with the other group using another axis to confirm the accuracy of the average algorithm (triple-axis group). Femoral components were more accurately implanted for rotational alignment in the triple-axis group (ideal: triple-axis group 100%, double-axis group 82%, P<0.05). Copyright © 2013 Elsevier Inc. All rights reserved.

  4. Single- versus dual-rod anterior instrumentation of thoracolumbar curves in adolescent idiopathic scoliosis.

    PubMed

    Nambiar, Mithun; Yang, Yi; Liew, Susan; Turner, Peter L; Torode, Ian P

    2016-10-01

    Single or dual-rod instrumentation can be used for the anterior fixation of the spine in adolescent idiopathic scoliosis (AIS). We aim to compare the complications, radiographic and functional outcomes of patients with AIS who have undergone single and dual-rod instrumentation. This is a multi-centre study involving the Royal Children's, Royal Melbourne and Epworth hospitals. Three primary surgeons were involved to ensure homogeneity of surgical technique and implants. Patients with AIS and thoracolumbar curves (Lenke 5 and 6) undergoing anterior instrumentation from 1st January 2000 to 30th June 2013 were included. Radiographic data were collected from X-rays. The functional outcome was measured through the Scoliosis Research Society questionnaire (SRS-30). The study included 58 patients (38 single-rod and 20 dual-rod patients). Thirty-nine patients were classified with Lenke 5 curves, while 19 patients had Lenke 6 curves. Structural interbody supports were used in 95 % of cases. In the preoperative to postoperative period, patients with single rods had an improvement of 75 and 51 % for primary and secondary curves, respectively, while patients with dual rods had an improvement of 70 and 38 % for primary and secondary curves, respectively. There were no cases of pseudoarthrosis or metalware failure in either group. Two patients (one single-rod and one dual-rod patient) required further unplanned posterior fusion. 91 % of patients were satisfied with the results of their back management. Pseudoarthrosis and metalware failure are rare complications of anterior instrumentation. Our study found no significant difference in functional or radiographic outcome between single and dual-rod instrumentation. Level III.

  5. Video-rate in vivo fluorescence imaging with a line-scanned dual-axis confocal microscope.

    PubMed

    Chen, Ye; Wang, Danni; Khan, Altaz; Wang, Yu; Borwege, Sabine; Sanai, Nader; Liu, Jonathan T C

    2015-10-01

    Video-rate optical-sectioning microscopy of living organisms would allow for the investigation of dynamic biological processes and would also reduce motion artifacts, especially for in vivo imaging applications. Previous feasibility studies, with a slow stage-scanned line-scanned dual-axis confocal (LS-DAC) microscope, have demonstrated that LS-DAC microscopy is capable of imaging tissues with subcellular resolution and high contrast at moderate depths of up to several hundred microns. However, the sensitivity and performance of a video-rate LS-DAC imaging system, with low-numerical aperture optics, have yet to be demonstrated. Here, we report on the construction and validation of a video-rate LS-DAC system that possesses sufficient sensitivity to visualize fluorescent contrast agents that are topically applied or systemically delivered in animal and human tissues. We present images of murine oral mucosa that are topically stained with methylene blue, and images of protoporphyrin IX-expressing brain tumor from glioma patients that have been administered 5-aminolevulinic acid prior to surgery. In addition, we demonstrate in vivo fluorescence imaging of red blood cells trafficking within the capillaries of a mouse ear, at frame rates of up to 30 fps. These results can serve as a benchmark for miniature in vivo microscopy devices under development.

  6. Video-rate in vivo fluorescence imaging with a line-scanned dual-axis confocal microscope

    NASA Astrophysics Data System (ADS)

    Chen, Ye; Wang, Danni; Khan, Altaz; Wang, Yu; Borwege, Sabine; Sanai, Nader; Liu, Jonathan T. C.

    2015-10-01

    Video-rate optical-sectioning microscopy of living organisms would allow for the investigation of dynamic biological processes and would also reduce motion artifacts, especially for in vivo imaging applications. Previous feasibility studies, with a slow stage-scanned line-scanned dual-axis confocal (LS-DAC) microscope, have demonstrated that LS-DAC microscopy is capable of imaging tissues with subcellular resolution and high contrast at moderate depths of up to several hundred microns. However, the sensitivity and performance of a video-rate LS-DAC imaging system, with low-numerical aperture optics, have yet to be demonstrated. Here, we report on the construction and validation of a video-rate LS-DAC system that possesses sufficient sensitivity to visualize fluorescent contrast agents that are topically applied or systemically delivered in animal and human tissues. We present images of murine oral mucosa that are topically stained with methylene blue, and images of protoporphyrin IX-expressing brain tumor from glioma patients that have been administered 5-aminolevulinic acid prior to surgery. In addition, we demonstrate in vivo fluorescence imaging of red blood cells trafficking within the capillaries of a mouse ear, at frame rates of up to 30 fps. These results can serve as a benchmark for miniature in vivo microscopy devices under development.

  7. Physical performance and radiographic and clinical vertebral fractures in older men.

    PubMed

    Cawthon, Peggy M; Blackwell, Terri L; Marshall, Lynn M; Fink, Howard A; Kado, Deborah M; Ensrud, Kristine E; Cauley, Jane A; Black, Dennis; Orwoll, Eric S; Cummings, Steven R; Schousboe, John T

    2014-09-01

    In men, the association between poor physical performance and likelihood of incident vertebral fractures is unknown. Using data from the MrOS study (N = 5958), we describe the association between baseline physical performance (walking speed, grip strength, leg power, repeat chair stands, narrow walk [dynamic balance]) and incidence of radiographic and clinical vertebral fractures. At baseline and follow-up an average of 4.6 years later, radiographic vertebral fractures were assessed using semiquantitative (SQ) scoring on lateral thoracic and lumbar radiographs. Logistic regression modeled the association between physical performance and incident radiographic vertebral fractures (change in SQ grade ≥1 from baseline to follow-up). Every 4 months after baseline, participants self-reported fractures; clinical vertebral fractures were confirmed by centralized radiologist review of the baseline study radiograph and community-acquired spine images. Proportional hazards regression modeled the association between physical performance with incident clinical vertebral fractures. Multivariate models were adjusted for age, bone mineral density (BMD, by dual-energy X-ray absorptiometry [DXA]), clinical center, race, smoking, height, weight, history of falls, activity level, and comorbid medical conditions; physical performance was analyzed as quartiles. Of 4332 men with baseline and repeat radiographs, 192 (4.4%) had an incident radiographic vertebral fracture. With the exception of walking speed, poorer performance on repeat chair stands, leg power, narrow walk, and grip strength were each associated in a graded manner with an increased risk of incident radiographic vertebral fracture (p for trend across quartiles <0.001). In addition, men with performance in the worst quartile on three or more exams had an increased risk of radiographic fracture (odds ratio [OR] = 1.81, 95% confidence interval [CI] 1.33-2.45) compared with men with better performance on all exams

  8. Experimental studies of 7-cell dual axis asymmetric cavity for energy recovery linac

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Konoplev, Ivan V.; Metodiev, K.; Lancaster, A. J.

    High average current, transportable energy recovery linacs (ERLs) can be very attractive tools for a number of applications including next generation high-luminosity, compact light sources. Conventional ERLs are based on an electron beam circulating through the same set of rf cavity cells. This leads to an accumulation of high-order modes inside the cavity cells, resulting in the development of a beam breakup (BBU) instability, unless the beam current is kept below the BBU start current. This limits the maximum current which can be transported through the ERL and hence the intensity of the photon beam generated. It has recently beenmore » proposed that splitting the accelerating and decelerating stages, tuning them separately and coupling them via a resonance coupler can increase the BBU start current. The paper presents the first experimental rf studies of a dual axis 7-cell asymmetric cavity and confirms the properties predicted by the theoretical model. The field structures of the symmetric and asymmetric modes are measured and good agreement with the numerical predictions is demonstrated. The operating mode field flatness was also measured and discussed. A novel approach based on the coupled mode (Fano-like) model has been developed for the description of the cavity eigenmode spectrum and good agreement between analytical theory, numerical predictions and experimental data is shown. Finally, numerical and experimental results observed are analyzed, discussed and a good agreement between theory and experiment is demonstrated.« less

  9. Experimental studies of 7-cell dual axis asymmetric cavity for energy recovery linac

    DOE PAGES

    Konoplev, Ivan V.; Metodiev, K.; Lancaster, A. J.; ...

    2017-10-10

    High average current, transportable energy recovery linacs (ERLs) can be very attractive tools for a number of applications including next generation high-luminosity, compact light sources. Conventional ERLs are based on an electron beam circulating through the same set of rf cavity cells. This leads to an accumulation of high-order modes inside the cavity cells, resulting in the development of a beam breakup (BBU) instability, unless the beam current is kept below the BBU start current. This limits the maximum current which can be transported through the ERL and hence the intensity of the photon beam generated. It has recently beenmore » proposed that splitting the accelerating and decelerating stages, tuning them separately and coupling them via a resonance coupler can increase the BBU start current. The paper presents the first experimental rf studies of a dual axis 7-cell asymmetric cavity and confirms the properties predicted by the theoretical model. The field structures of the symmetric and asymmetric modes are measured and good agreement with the numerical predictions is demonstrated. The operating mode field flatness was also measured and discussed. A novel approach based on the coupled mode (Fano-like) model has been developed for the description of the cavity eigenmode spectrum and good agreement between analytical theory, numerical predictions and experimental data is shown. Finally, numerical and experimental results observed are analyzed, discussed and a good agreement between theory and experiment is demonstrated.« less

  10. Single-shot dual-wavelength in-line and off-axis hybrid digital holography

    NASA Astrophysics Data System (ADS)

    Wang, Fengpeng; Wang, Dayong; Rong, Lu; Wang, Yunxin; Zhao, Jie

    2018-02-01

    We propose an in-line and off-axis hybrid holographic real-time imaging technique. The in-line and off-axis digital holograms are generated simultaneously by two lasers with different wavelengths, and they are recorded using a color camera with a single shot. The reconstruction is carried using an iterative algorithm in which the initial input is designed to include the intensity of the in-line hologram and the approximate phase distributions obtained from the off-axis hologram. In this way, the complex field in the object plane and the output by the iterative procedure can produce higher quality amplitude and phase images compared to traditional iterative phase retrieval. The performance of the technique has been demonstrated by acquiring the amplitude and phase images of a green lacewing's wing and a living moon jellyfish.

  11. High mobility, dual layer, c-axis aligned crystalline/amorphous IGZO thin film transistor

    NASA Astrophysics Data System (ADS)

    Chung, Chen-Yang; Zhu, Bin; Greene, Raymond G.; Thompson, Michael O.; Ast, Dieter G.

    2015-11-01

    We demonstrate a dual layer IGZO thin film transistor (TFT) consisting of a 310 °C deposited c-axis aligned crystal (CAAC) 20 nm thick channel layer capped by a second, 30 nm thick, 260 °C deposited amorphous IGZO layer. The TFT exhibits a saturation field-effect mobility of ˜20 cm2/V s, exceeding the mobility of 50 nm thick single layer reference TFTs fabricated with either material. The deposition temperature of the second layer influences the mobility of the underlying transport layer. When the cap layer is deposited at room temperature (RT), the mobility in the 310 °C deposited CAAC layer is initially low (6.7 cm2/V s), but rises continuously with time over 58 days to 20.5 cm2/V s, i.e., to the same value as when the second layer is deposited at 260 °C. This observation indicates that the two layers equilibrate at RT with a time constant on the order of 5 × 106 s. An analysis based on diffusive transport indicates that the room temperature diffusivity must be of the order of 1 × 10-18 cm2 s-1 with an activation enthalpy EA < 0.2 eV for the mobility limiting species. The findings are consistent with a hypothesis that the amorphous layer deposited on top of the CAAC has a higher solubility for impurities and/or structural defects than the underlying nanocrystalline transport layer, and that the equilibration of the mobility limiting species is rate limited by hydrogen diffusion, whose known diffusivity fits these estimates.

  12. Radiation modelling and performance evaluations of fixed, single- and double-axis tracking surfaces: a case study for Dhahran city, Saudi Arabia

    NASA Astrophysics Data System (ADS)

    Abdulsalam, Alrowashed; Idris, Azni Bin; Ahmad, Thamer; Ahsan, Amimul

    2017-01-01

    This work overviews the solar radiation basics and insolation of different surfaces is presented. A complete solar radiation modelling and investigation on the effect of horizontal plate, yearly tilt, monthly tilt, and single-axis and double-axis tracking surface on the insolation are carried out to conduct performance evaluation using the case study in Dhahran city of Saudi Arabia. The increments received by insolation for the yearly tilt, monthly tilt, and single-axis and dual-axis tracking surface with respect to traditional flat-plate collector is estimated. The results show that the yearly optimal tilt angle due to the south is close to the 0.913 time latitude of Dhahran. It is found that the yearly irradiation gains using yearly and monthly optimal tilts relative to flat panel installation are 7% and 14%, respectively. The yearly insulation gains made by single-axis and dual-axis continuous tracking surfaces are 33% and 48%, respectively.

  13. Efficient Dual Head Nd:YAG 100mJ Oscillator for Remote Sensing

    NASA Technical Reports Server (NTRS)

    Coyle, Donald B.; Stysley, Paul R.; Kay, Richard b.; Poulios, Demetrios

    2007-01-01

    A diode pumped, Nd:YAG laser producing 100 mJ Q-switched pulses and employing a dual-pump head scheme in an unstable resonator configuration is described. Each head contains a side pumped zig-zag slab and four 6-bar QCW 808 nm diodes arrays which are de-rated 23%. Denoting 'z' as the lasing axis, the pump directions were along the x-axis in one head and the y-axis in the other, producing a circularized thermal lens, more typical in laser rod-based cavities. The dual head design's effective thermal lens is now corrected with a proper HR mirror curvature selection. This laser has demonstrated over 100 mJ output with high optical efficiency (24%), good TEM(sub 00) beam quality, and high pointing stability.

  14. Sensitivity and specificity of radiographic methods for predicting insertion torque of dental implants.

    PubMed

    Cortes, Arthur Rodriguez Gonzalez; Eimar, Hazem; Barbosa, Jorge de Sá; Costa, Claudio; Arita, Emiko Saito; Tamimi, Faleh

    2015-05-01

    Subjective radiographic classifications of alveolar bone have been proposed and correlated with implant insertion torque (IT). The present diagnostic study aims to identify quantitative bone features influencing IT and to use these findings to develop an objective radiographic classification for predicting IT. Demographics, panoramic radiographs (taken at the beginning of dental treatment), and cone-beam computed tomographic scans (taken for implant surgical planning) of 25 patients receiving 31 implants were analyzed. Bone samples retrieved from implant sites were assessed with dual x-ray absorptiometry, microcomputed tomography, and histology. Odds ratio, sensitivity, and specificity of all variables to predict high peak IT were assessed. A ridge cortical thickness >0.75 mm and a normal appearance of the inferior mandibular cortex were the most sensitive variables for predicting high peak IT (87.5% and 75%, respectively). A classification based on the combination of both variables presented high sensitivity (90.9%) and specificity (100%) for predicting IT. Within the limitations of this study, the results suggest that it is possible to predict IT accurately based on radiographic findings of the patient. This could be useful in the treatment plan of immediate loading cases.

  15. Is the gravity effect of radiographic anatomic features enough to justify stone clearance or fragments retention following extracorporeal shock wave lithotripsy (SWL).

    PubMed

    Mustafa, Mahmoud

    2012-08-01

    We determined whether the gravity effect of radiographic anatomic features on the preoperative urography (IVP) are enough to predict fragments clearance after shock wave lithotripsy (SWL). A Total of 282 patients with mean age 45.8 ± 13.2 years (189 male, 93 female), who underwent SWL due to renal calculi between October 2005 and August 2009 were enrolled. The mean calculi load was 155.72 ± 127.66 mm². The patients were stratified into three groups: patients with pelvis calculi (group 1); patients with upper or middle pole calculi (group 2) and patients with lower pole calculi (group 3). Three angles on the pretreatment IVP were measured: the inner angle between the axis of the lower pole infundibular and ureteropelvic axis (angle I); the inner angle between the lower pole infundibular axis and main axis of pelvis-ureteropelvic (UP) junction point (angle II) and the inner angle between the lower pole infundibular axis and perpendicular line (angle III). Multivariate analysis was used to define the significant predictors of stone clearance. The overall success rate was 85.81%. All angles, sessions number, shock waves number and stone burden were significant predictors of success in patients in group 1. However, in group 2 only angle II and in group 3 angles I and II had significant effect on stone clearance. Radiographic anatomic features have significant role in determining the stone-free rate following satisfactory fragmentation of renal stones with SWL. The measurement of infundibulopelvic angle in different manner helps to predict the stone-free status in patients with renal calculi located not only in lower pole, but also in renal pelvis and upper or middle pole. Gravity effect is not enough to justify the significant influence of the radiographic anatomic features on the stone clearance and fragments retention after SWL.

  16. Reducing the spatial resolution range of neutron radiographs cast by thick objects

    NASA Astrophysics Data System (ADS)

    Almeida, G. L.; Silvani, M. I.; Souza, E. S.; Lopes, R. T.

    2017-11-01

    The quality of a neutron radiograph is strongly dependent upon the features of the acquisition system. Most of them, such as detector resolution, electronic noise and statistical fluctuation can hardly be improved. Yet, a main parameter ruling the image spatial resolution, namely the L/D ratio of the system can be increased simply by lengthening the source-detector clearance. Such an option eventually may not be feasible due to neutron flux decreasing or engineering constraints. Under this circumstance, a radiograph improvement is only possible by some kind of after-acquisition procedure capable to retrieve, at least partially, the information concealed by the degradation process. Since the spoiling agent tied to the L/D has a systematic character, its impact can be reduced by an unfolding procedure such as Richardson-Lucy algorithm. However, that agent should be fully characterized and furnished to the algorithm as a Point Spread Function - PSF unfolding function. A main drawback of unfolding algorithms like Richardson-Lucy is that the PSF should be fixed, i.e., it assumes a certain constant image spatial resolution, rather than a variable one as actually occurs for thick objects. This work presents a methodology to minimize this difficulty by making all planes of the inspected object to cast a resolution within the shorter gap comprised between the object central plane and the detector. The image can then be unfolded with a lower resolution within a tighter range, yielding a better quality. The process is performed with two radiographs, where one of them is acquired with the object turned by 180° on its vertical axis with regard to the other. After a mirroring of one of them about its vertical axis, the images are added. As the resolution increases linearly with the object-detector gap, it would remain always lower than that of the central one. Therefore, the overall resolution of the composite radiograph is enhanced. A further improvement can then be achieved

  17. Monosodium urate crystal deposition associated with the progress of radiographic grade at the sacroiliac joint in axial SpA: a dual-energy CT study.

    PubMed

    Zhu, Junqing; Li, Aiwu; Jia, Ertao; Zhou, Yi; Xu, Juan; Chen, Shixian; Huang, Yinger; Xiao, Xiang; Li, Juan

    2017-05-02

    Previous studies have revealed that ankylosing spondylitis (AS), as the progenitor of axial spondyloarthritis (AxSpA), has been characterized by the insidiously progressive nature of sacroiliitis and spondylitis. Dual-energy computed tomography (DECT) has recently been used to analyse the deposition of monosodium urate (MSU) crystals with higher sensitivity and specificity. However, it remains unclear whether the existence of the MSU crystal deposition detected by DECT at the sacroiliac joint in patients with AxSpA also is associated with the existing structural damage. Here, we performed this study to show the DECT MSU crystal deposits in AxSpA patients without coexisting gout and to ascertain the relationship between the MSU crystal deposition and the structural joint damage of sacroiliac joints. One hundred and eighty-six AxSpA patients without coexisting gout were recruited. The plain radiographs of the sacroiliac joint were obtained, along with the DECT scans at the pelvis and the clinical variables. All statistics based on the left or right sacroiliac joint damage grading (0-4) were calculated independently. Bivariate analysis and ordinal logistic regression was performed between the clinical features and radiographic grades at the sacroiliac joint. At the pelvis, large quantities of MSU crystal deposition were found in patients with AxSpA. The average MSU crystal volume at the left sacroiliac joint, the right sacroiliac joint, and the pelvis were 0.902 ± 1.345, 1.074 ± 1.878, and 5.272 ± 9.044 cm 3 , values which were correlated with serum uric acid concentrations (r = 0.727, 0.740, 0.896; p < 0.001). In bivariate analysis, wide clinical variables were associated with the changes in sacroiliac joint damage. Further, the AxSpA duration, BASFI score, and the volume of MSU crystal at both sides of sacroiliac joint were associated with the progress of radiographic grade at the sacroiliac joints in the ordinal logistic models (left AOR

  18. Radiographic outcomes of single versus dual plate fixation of acute mid-shaft clavicle fractures.

    PubMed

    Chen, Xiaobin; Shannon, Steven F; Torchia, Michael; Schoch, Bradley

    2017-06-01

    The clavicle exhibits considerable movement in three planes making rigid fixation challenging. The addition of a second plate may be considered to improve fixation rigidity, but risks compromising the blood supply to the fracture site. The purpose of this study is to assess if extraperiosteal dual plate fixation increases the rate of non-union, reoperation, and complications at 1 year for surgically treated acute mid-shaft clavicle fractures. Between June 1998 and June 2013, surgically treated mid-shaft clavicle fractures undergoing open reduction internal fixation within 4 weeks of injury were retrospectively reviewed. Patients undergoing single plate fixation were compared to dual plate fixation. Patients were followed for a minimum of 1 year. Charts were reviewed to assess union rates, reoperation, and complications. One hundred and sixty-three clavicles (125 single plates, 34 dual plates) were evaluated. All patients (100%) in dual plating group and one hundred and fourteen (91%) in single plating group obtained bony union by 1 year (p = 0.13). Six patients (4.8%) experienced a non-union in the single plating cohort compared to the dual plating cohort who had a 100% union rate. Seven patients required reoperation in the single plate cohort due to implant failure (N = 4), infection (N = 2), and non-union (N = 1). This limited series of patients demonstrates dual plate fixation is a reliable option for acute mid-shaft clavicle fractures, with excellent union rates and low complication rates. Compared to single plate fixation, no significant differences in outcomes were identified. In the case of more complex fracture patterns, application of a second extraperiosteal plate may be utilized without compromising healing or increasing complication rates.

  19. High precision dual-axis tracking solar wireless charging system based on the four quadrant photoelectric sensor

    NASA Astrophysics Data System (ADS)

    Liu, Zhilong; Wang, Biao; Tong, Weichao

    2015-08-01

    This paper designs a solar automatic tracking wireless charging system based on the four quadrant photoelectric sensor. The system track the sun's rays automatically in real time to received the maximum energy and wireless charging to the load through electromagnetic coupling. Four quadrant photoelectric sensor responsive to the solar spectrum, the system could get the current azimuth and elevation angle of the light by calculating the solar energy incident on the sensor profile. System driver the solar panels by the biaxial movement mechanism to rotate and tilt movement until the battery plate and light perpendicular to each other. Maximize the use of solar energy, and does not require external power supply to achieve energy self-sufficiency. Solar energy can be collected for portable devices and load wireless charging by close electromagnetic field coupling. Experimental data show that: Four quadrant photoelectric sensor more sensitive to light angle measurement. when track positioning solar light, Azimuth deviation is less than 0.8°, Elevation angle deviation is less than 0.6°. Use efficiency of a conventional solar cell is only 10% -20%.The system uses a Four quadrant dual-axis tracking to raise the utilization rate of 25% -35%.Wireless charging electromagnetic coupling efficiency reached 60%.

  20. A Two-Axis Direct Fluid Shear Stress Sensor

    NASA Technical Reports Server (NTRS)

    Adcock, Edward E.; Scott, Michael A.; Bajikar, Sateesh S.

    2010-01-01

    This innovation is a miniature or micro sized semiconductor sensor design that provides two axis direct non-intrusive measurement of skin friction or wall shear stress in fluid flow. The sensor is fabricated by micro-electro-mechanical system (MEMS) technology, enabling small size and low cost reproductions. The sensors have been fabricated by utilizing MEMS fabrication processes to bond a sensing element wafer to a fluid coupling wafer. This layering technique provides for an out of plane dimension that is on the same order of length as the inplane dimensions. The sensor design has the following characteristics: a shear force collecting plate with dimensions that can be tailored to various application specific requirements such as spatial resolution, temporal resolution and shear force range and resolution. This plate is located coplanar to both the sensor body and flow boundary, and is connected to a dual axis gimbal structure by a connecting column or lever arm. The dual axis gimbal structure has torsional hinges with embedded piezoresistive torsional strain gauges which provide a voltage output that is correlated to the applied shear stress (and excitation current) on force collection plate that is located on the flow boundary surface (hence the transduction method). This combination of design elements create a force concentration and resolution structure that enables the generation of a large stress on the strain gauge from the small shear stress on the flow boundary wall. This design as well as the use of back side electrical contacts establishes a non-intrusive method to quantitatively measure the shear force vector on aerodynamic bodies.

  1. Radiographer.

    ERIC Educational Resources Information Center

    Ohio State Univ., Columbus. Center on Education and Training for Employment.

    This document, which is designed for use in developing a tech prep competency profile for the occupation of radiographer, lists technical competencies and competency builders for 18 units pertinent to the health technologies cluster in general as well as those specific to the occupation of radiographer. The following skill areas are covered in the…

  2. Accuracy of radiographs in assessment of displacement in lateral humeral condyle fractures.

    PubMed

    Knutsen, Ashleen; Avoian, Tigran; Borkowski, Sean L; Ebramzadeh, Edward; Zionts, Lewis E; Sangiorgio, Sophia N

    2014-02-01

    Determining the magnitude of displacement in pediatric lateral humeral condyle fractures can be difficult. The purpose of this study was to (1) assess the effect of forearm rotation on true fracture displacement using a cadaver model and to (2) determine the accuracy of radiographic measurements of the fracture gap. A non-displaced fracture was created in three human cadaveric arms. The specimens were mounted on a custom apparatus allowing forearm rotation with the humerus fixed. First, the effect of pure rotation on fracture displacement was simulated by rotating the forearm from supination to pronation about the central axis of the forearm, to isolate the effects of muscle pull. Then, the clinical condition of obtaining a lateral oblique radiograph was simulated by rotating the forearm about the medial aspect of the forearm. Fracture displacements were measured using a motion-capture system (true-displacement) and clinical radiographs (apparent-displacement). During pure rotation of the forearm, there were no significant differences in fracture displacement between supination and pronation, with changes in displacement of <1.0 mm. During rotation about the medial aspect of the forearm, there was a significant difference in true displacements between supination and pronation at the posterior edge (p < 0.05). Overall, true fracture displacement measurements were larger than apparent radiographic displacement measurements, with differences from 1.6 to 6.0 mm, suggesting that the current clinical methods may not be sensitive enough to detect a displacement of 2.0 mm, especially when positioning the upper extremity for an internal oblique lateral radiograph.

  3. Real-time simulator for designing electron dual scattering foil systems.

    PubMed

    Carver, Robert L; Hogstrom, Kenneth R; Price, Michael J; LeBlanc, Justin D; Pitcher, Garrett M

    2014-11-08

    The purpose of this work was to develop a user friendly, accurate, real-time com- puter simulator to facilitate the design of dual foil scattering systems for electron beams on radiotherapy accelerators. The simulator allows for a relatively quick, initial design that can be refined and verified with subsequent Monte Carlo (MC) calculations and measurements. The simulator also is a powerful educational tool. The simulator consists of an analytical algorithm for calculating electron fluence and X-ray dose and a graphical user interface (GUI) C++ program. The algorithm predicts electron fluence using Fermi-Eyges multiple Coulomb scattering theory with the reduced Gaussian formalism for scattering powers. The simulator also estimates central-axis and off-axis X-ray dose arising from the dual foil system. Once the geometry of the accelerator is specified, the simulator allows the user to continuously vary primary scattering foil material and thickness, secondary scat- tering foil material and Gaussian shape (thickness and sigma), and beam energy. The off-axis electron relative fluence or total dose profile and central-axis X-ray dose contamination are computed and displayed in real time. The simulator was validated by comparison of off-axis electron relative fluence and X-ray percent dose profiles with those calculated using EGSnrc MC. Over the energy range 7-20 MeV, using present foils on an Elekta radiotherapy accelerator, the simulator was able to reproduce MC profiles to within 2% out to 20 cm from the central axis. The central-axis X-ray percent dose predictions matched measured data to within 0.5%. The calculation time was approximately 100 ms using a single Intel 2.93 GHz processor, which allows for real-time variation of foil geometrical parameters using slider bars. This work demonstrates how the user-friendly GUI and real-time nature of the simulator make it an effective educational tool for gaining a better understanding of the effects that various system

  4. The vibration discomfort of standing people: evaluation of multi-axis vibration.

    PubMed

    Thuong, Olivier; Griffin, Michael J

    2015-01-01

    Few studies have investigated discomfort caused by multi-axis vibration and none has explored methods of predicting the discomfort of standing people from simultaneous fore-and-aft, lateral and vertical vibration of a floor. Using the method of magnitude estimation, 16 subjects estimated their discomfort caused by dual-axis and tri-axial motions (octave-bands centred on either 1 or 4 Hz with various magnitudes in the fore-and-aft, lateral and vertical directions) and the discomfort caused by single-axis motions. The method of predicting discomfort assumed in current standards (square-root of the sums of squares of the three components weighted according to their individual contributions to discomfort) provided reasonable predictions of the discomfort caused by multi-axis vibration. Improved predictions can be obtained for specific stimuli, but no single simple method will provide accurate predictions for all stimuli because the rate of growth of discomfort with increasing magnitude of vibration depends on the frequency and direction of vibration.

  5. Emittance Growth in the DARHT-II Linear Induction Accelerator

    NASA Astrophysics Data System (ADS)

    Ekdahl, Carl; Carlson, Carl A.; Frayer, Daniel K.; McCuistian, B. Trent; Mostrom, Christopher B.; Schulze, Martin E.; Thoma, Carsten H.

    2017-11-01

    The Dual-Axis Radiographic Hydrotest (DARHT) facility uses bremsstrahlung radiation source spots produced by the focused electron beams from two linear induction accelerators (LIAs) to radiograph large hydrodynamic experiments driven by high explosives. Radiographic resolution is determined by the size of the source spot, and beam emittance is the ultimate limitation to spot size. Some of the possible causes for the emittance growth in the DARHT LIA have been investigated using particle-in-cell (PIC) codes, and are discussed in this article. The results suggest that the most likely source of emittance growth is a mismatch of the beam to the magnetic transport, which can cause beam halo.

  6. Two-axis direct fluid shear stress sensor

    NASA Technical Reports Server (NTRS)

    Bajikar, Sateesh (Inventor); Scott, Michael A. (Inventor); Adcock, Edward E. (Inventor)

    2011-01-01

    A micro sized multi-axis semiconductor skin friction/wall shear stress induced by fluid flow. The sensor design includes a shear/strain transduction gimble connected to a force collecting plate located at the flow boundary surface. The shear force collecting plate is interconnected by an arm to offset the tortional hinges from the fluid flow. The arm is connected to the shear force collecting plate through dual axis torsional hinges with piezoresistive torsional strain gauges. These gauges are disposed on the tortional hinges and provide a voltage output indicative of applied shear stress acting on the force collection plate proximate the flow boundary surface. Offsetting the torsional hinges creates a force concentration and resolution structure that enables the generation of a large stress on the strain gauge from small shear stress, or small displacement of the collecting plate. The design also isolates the torsional sensors from exposure to the fluid flow.

  7. A diode-pumped Nd:YAlO3 dual-wavelength yellow light source

    NASA Astrophysics Data System (ADS)

    Zhang, Jing; Fu, Xihong; Zhai, Pei; Xia, Jing; Li, Shutao

    2013-11-01

    We present what is, to the best of our knowledge, the first diode-pumped Nd:YAlO3 (Nd:YAP) continuous-wave (cw) dual-wavelength yellow laser at 593 nm and 598 nm, based on sum-frequency generation between 1064 and 1339 nm in a-axis polarization using LBO crystal and between 1079 and 1341 nm in c-axis polarization using PPKTP crystal, respectively. At an incident pump power of 17.3 W, the maximum output power obtained at 593 nm and 598 nm is 0.18 W and 1.86 W, respectively. The laser experiment shows that Nd:YAP crystal can be used for an efficient diode-pumped dual-wavelength yellow laser system.

  8. Estimation of the axis of a screw motion from noisy data--a new method based on Plücker lines.

    PubMed

    Kiat Teu, Koon; Kim, Wangdo

    2006-01-01

    The problems of estimating the motion and orientation parameters of a body segment from two n point-set patterns are analyzed using the Plücker coordinates of a line (Plücker lines). The aim is to find algorithms less complex than those in conventional use, and thus facilitating more accurate computation of the unknown parameters. All conventional techniques use point transformation to calculate the screw axis. In this paper, we present a novel technique that directly estimates the axis of a screw motion as a Plücker line. The Plücker line can be transformed via the dual-number coordinate transformation matrix. This method is compared with Schwartz and Rozumalski [2005. A new method for estimating joint parameters from motion data. Journal of Biomechanics 38, 107-116] in simulations of random measurement errors and systematic skin movements. Simulation results indicate that the methods based on Plücker lines (Plücker line method) are superior in terms of extremely good results in the determination of the screw axis direction and position as well as a concise derivation of mathematical statements. This investigation yielded practical results, which can be used to locate the axis of a screw motion in a noisy environment. Developing the dual transformation matrix (DTM) from noisy data and determining the screw axis from a given DTM is done in a manner analogous to that for handling simple rotations. A more robust approach to solve for the dual vector associated with DTM is also addressed by using the eigenvector and the singular value decomposition.

  9. Segmentation of lung fields using Chan-Vese active contour model in chest radiographs

    NASA Astrophysics Data System (ADS)

    Sohn, Kiwon

    2011-03-01

    A CAD tool for chest radiographs consists of several procedures and the very first step is segmentation of lung fields. We develop a novel methodology for segmentation of lung fields in chest radiographs that can satisfy the following two requirements. First, we aim to develop a segmentation method that does not need a training stage with manual estimation of anatomical features in a large training dataset of images. Secondly, for the ease of implementation, it is desirable to apply a well established model that is widely used for various image-partitioning practices. The Chan-Vese active contour model, which is based on Mumford-Shah functional in the level set framework, is applied for segmentation of lung fields. With the use of this model, segmentation of lung fields can be carried out without detailed prior knowledge on the radiographic anatomy of the chest, yet in some chest radiographs, the trachea regions are unfavorably segmented out in addition to the lung field contours. To eliminate artifacts from the trachea, we locate the upper end of the trachea, find a vertical center line of the trachea and delineate it, and then brighten the trachea region to make it less distinctive. The segmentation process is finalized by subsequent morphological operations. We randomly select 30 images from the Japanese Society of Radiological Technology image database to test the proposed methodology and the results are shown. We hope our segmentation technique can help to promote of CAD tools, especially for emerging chest radiographic imaging techniques such as dual energy radiography and chest tomosynthesis.

  10. The dual blocker of FAAH/TRPV1 N-arachidonoylserotonin reverses the behavioral despair induced by stress in rats and modulates the HPA-axis.

    PubMed

    Navarria, Andrea; Tamburella, Alessandra; Iannotti, Fabio A; Micale, Vincenzo; Camillieri, Giovanni; Gozzo, Lucia; Verde, Roberta; Imperatore, Roberta; Leggio, Gian Marco; Drago, Filippo; Di Marzo, Vincenzo

    2014-09-01

    In recent years, several studies have explored the involvement of the deregulation of the hypothalamus-pituitary-adrenal (HPA) axis in the pathophysiology of stress-related disorders. HPA hyper-activation as a consequence of acute/chronic stress has been found to play a major role in the neurobiological changes that are responsible for the onset of such states. Currently available medications for depression, one of the most relevant stress-related disorders, present several limitations, including a time lag for treatment response and low rates of efficacy. N-Arachidonoylserotonin (AA-5-HT), a dual blocker at fatty acid amide hydrolase (FAAH, the enzyme responsible for the inactivation of the endocannabinoid anandamide) and transient receptor potential vanilloid type-1 channel (TRPV1), produces anxiolytic-like effects in mice. The present study was designed to assess the capability of AA-5-HT to reverse the behavioral despair following exposure to stress in rats and the role of the HPA-axis. Behavioral tasks were performed, and corticosterone and endocannabinoid (anandamide and 2-arachidonoylglycerol) levels were measured in selected brain areas critically involved in the pathophysiology of stress-related disorders (medial PFC and hippocampus) under basal and stress conditions, and in response to treatment with AA-5-HT. Our data show that AA-5-HT reverses the rat behavioral despair in the forced swim test under stress conditions, and this effect is associated with the normalization of the HPA-axis deregulation that follows stress application and only in part with elevation of anandamide levels. Blockade of FAAH and TRPV1 may thus represent a novel target to design novel therapeutic strategies for the treatment of stress-related disorders. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. AXIS - Advanced X-ray Imaging Sarellite

    NASA Astrophysics Data System (ADS)

    Loewenstein, Michael; AXIS Team

    2018-01-01

    We present an overview of the Advanced X-ray Imaging Satellite (AXIS), a probe mission concept under study to the 2020 Decadal survey. AXIS follows in the footsteps of the spectacularly successful Chandra X-ray Observatory with similar or higher angular resolution and an order of magnitude more collecting area in the 0.3-10 keV band over a 15' field of view. These capabilities are designed to attain a wide range of science goals such as (i) measuring the event horizon scale structure in AGN accretion disks and the spin of supermassive black holes through monitoring of gravitationally microlensed quasars; (ii) understanding AGN and starburst feedback in galaxies and galaxy clusters through direct imaging of winds and interaction of jets and via spatially resolved imaging of galaxies at high-z; (iii) probing the fueling of AGN by resolving the SMBH sphere of influence in nearby galaxies; (iv) investigating hierarchical structure formation and the SMBH merger rate through measurement of the occurrence rate of dual AGN and occupation fraction of SMBHs; (v) advancing SNR physics and galaxy ecology through large detailed samples of SNR in nearby galaxies; (vi) measuring the Cosmic Web through its connection to cluster outskirts. With a nominal 2028 launch, AXIS benefits from natural synergies with LSST, ELTs, ALMA, WFIRST and ATHENA, and will be a valuable precursor to Lynx. AXIS utilizes breakthroughs in the construction of light-weight X-ray optics from mono-crystalline silicon blocks, and developments in the fabrication of large format, small pixel, high readout detectors.

  12. Dual-axis resonance testing of wind turbine blades

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hughes, Scott; Musial, Walter; White, Darris

    An apparatus (100) for fatigue testing test articles (104) including wind turbine blades. The apparatus (100) includes a test stand (110) that rigidly supports an end (106) of the test article (104). An actuator assembly (120) is attached to the test article (104) and is adapted for substantially concurrently imparting first and second forcing functions in first and second directions on the test article (104), with the first and second directions being perpendicular to a longitudinal axis. A controller (130) transmits first and second sets of displacement signals (160, 164) to the actuator assembly (120) at two resonant frequencies ofmore » the test system (104). The displacement signals (160, 164) initiate the actuator assembly (120) to impart the forcing loads to concurrently oscillate the test article (104) in the first and second directions. With turbine blades, the blades (104) are resonant tested concurrently for fatigue in the flapwise and edgewise directions.« less

  13. Assessing delivery and quantifying efficacy of small interfering ribonucleic acid therapeutics in the skin using a dual-axis confocal microscope

    NASA Astrophysics Data System (ADS)

    Ra, Hyejun; Gonzalez-Gonzalez, Emilio; Smith, Bryan R.; Gambhir, Sanjiv S.; Kino, Gordon S.; Solgaard, Olav; Kaspar, Roger L.; Contag, Christopher H.

    2010-05-01

    Transgenic reporter mice and advances in imaging instrumentation are enabling real-time visualization of cellular mechanisms in living subjects and accelerating the development of novel therapies. Innovative confocal microscope designs are improving their utility for microscopic imaging of fluorescent reporters in living animals. We develop dual-axis confocal (DAC) microscopes for such in vivo studies and create mouse models where fluorescent proteins are expressed in the skin for the purpose of advancing skin therapeutics and transdermal delivery tools. Three-dimensional image volumes, through the different skin compartments of the epidermis and dermis, can be acquired in several seconds with the DAC microscope in living mice, and are comparable to histologic analyses of reporter protein expression patterns in skin sections. Intravital imaging with the DAC microscope further enables visualization of green fluorescent protein (GFP) reporter gene expression in the skin over time, and quantification of transdermal delivery of small interfering RNA (siRNA) and therapeutic efficacy. Visualization of transdermal delivery of nucleic acids will play an important role in the development of innovative strategies for treating skin pathologies.

  14. Weld radiograph enigmas

    NASA Technical Reports Server (NTRS)

    Jemian, Wartan A.

    1986-01-01

    Weld radiograph enigmas are features observed on X-ray radiographs of welds. Some of these features resemble indications of weld defects, although their origin is different. Since they are not understood, they are a source of concern. There is a need to identify their causes and especially to measure their effect on weld mechanical properties. A method is proposed whereby the enigmas can be evaluated and rated, in relation to the full spectrum of weld radiograph indications. Thie method involves a signature and a magnitude that can be used as a quantitive parameter. The signature is generated as the diference between the microdensitometer trace across the radiograph and the computed film intensity derived from a thickness scan along the corresponding region of the sample. The magnitude is the measured difference in intensity between the peak and base line values of the signature. The procedure is demonstated by comparing traces across radiographs of a weld sample before and after the introduction of a hole and by a system based on a MacIntosh mouse used for surface profiling.

  15. How DARHT Works - the World's Most Powerful X-ray Machine

    ScienceCinema

    None

    2018-06-01

    The Dual Axis Radiographic Hydrodynamic Test (DARHT) facility at Los Alamos National Laboratory is an essential scientific tool that supports Stockpile Stewardship at the Laboratory. The World's most powerful x-ray machine, it's used to take high-speed images of mock nuclear devices - data that is used to confirm and modify advanced computer codes in assuring the safety, security, and effectiveness of the U.S. nuclear deterrent.

  16. Broadband Venetian Blind polarizer with dual vanes

    NASA Technical Reports Server (NTRS)

    Conroy, Bruce L.; Hoppe, Daniel J.; Imbriale, William A.

    1993-01-01

    During development of a Venetian Blind polarizer, high reflections and substantial pattern deformation were noted. Analysis showed that when the polarizer was illuminated slightly off axis, a degenerate mode was excited. This mode is resonant at the design center frequency, and was the cause of the problems. A design developed using dual vanes has been shown to be free of the problem. It also has greater bandwidth.

  17. Usefulness of Chest Radiographs for Scoliosis Screening: A Comparison with Thoraco-Lumbar Standing Radiographs

    PubMed Central

    Oh, Chang Hyun; Kim, Chan Gyu; Lee, Myoung Seok; Park, Hyeong-Chun; Park, Chong Oon

    2012-01-01

    Purpose The purposes of this study were to evaluate the usefulness and limitations of chest radiographs in scoliosis screening and to compare these results with those of thoraco-lumbar standing radiographs (TLSR). Materials and Methods During Korean conscription, 419 males were retrospectively examined using both chest radiographs and TLSR to confirm the scoliosis and Cobb angle at the Regional Military Manpower. We compared the types of spinal curves and Cobb angles as measured from different radiographs. Results In the pattern of spinal curves, the overall matching rate of chest radiographs using TLSR was about 58.2% (244 of 419 cases). Cobb angle differences between chest radiographs and TLSR with meaningful difference was observed in 156 cases (37.2%); a relatively high proportion (9.5%) of Cobb angle differences more than 10 degrees was also observed. The matching rate of both spinal curve types and Cobb angle accuracy between chest radiographs and TLSR was 27.9% (117 among 419 cases). Chest radiographs for scoliosis screening were observed with 93.94% of sensitivity and 61.67% of specificity in thoracic curves; however, less than 40% of sensitivity (38.27%, 20.00%, and 25.80%) and more than 95% of specificity (97.34%, 99.69%, and 98.45%) were observed in thoraco-lumbar, lumbar, and double major curves, respectively. Conclusion The accuracy of chest radiographs for scoliosis screening was low. The incidence of thoracic curve scoliosis was overestimated and lumbar curve scoliosis was easily missed by chest radiography. Scoliosis screening using chest radiography has limited values, nevertheless, it is useful method for detecting thoracic curve scoliosis. PMID:23074120

  18. Dental digital radiographic imaging.

    PubMed

    Mauriello, S M; Platin, E

    2001-01-01

    Radiographs are an important adjunct to providing oral health care for the total patient. Historically, radiographic images have been produced using film-based systems. However, in recent years, with the arrival of new technologies, many practitioners have begun to incorporate digital radiographic imaging into their practices. Since dental hygienists are primarily responsible for exposing and processing radiographs in the provision of dental hygiene care, it is imperative that they become knowledgeable on the use and application of digital imaging in patient care and record keeping. The purpose of this course is to provide a comprehensive overview of digital radiography in dentistry. Specific components addressed are technological features, diagnostic software, advantages and disadvantages, technique procedures, and legal implications.

  19. Generalized bone loss as a predictor of three-year radiographic damage in African American patients with recent-onset rheumatoid arthritis.

    PubMed

    Zhang, Jie; Redden, David T; McGwin, Gerald; Callahan, Leigh F; Smith, Edwin A; Alarcón, Graciela S; Moreland, Larry W; van der Heijde, Désirée M; Brown, Elizabeth E; Arnett, Donna K; Mikuls, Ted R; Bridges, S Louis

    2010-08-01

    To examine the association between baseline bone mineral density (BMD) and radiographic damage at 3 years of disease duration in a longitudinal cohort of African Americans with recent-onset rheumatoid arthritis (RA). African American RA patients with a disease duration of <2 years (n = 141) were included in the study. All patients underwent baseline BMD measurements (femoral neck and/or lumbar spine) using dual x-ray absorptiometry. T scores were calculated using normative data from the general population of African Americans. Patients were categorized as having osteopenia/osteoporosis (T score less than or equal to -1) or as being healthy. Hand and wrist radiographs, obtained at baseline and at 3 years of disease duration, were scored using the modified Sharp/van der Heijde method. The association between baseline BMD and total radiographic score at 3 years of disease was examined using multivariable negative binomial regression. At baseline, the mean age and the mean disease duration were 52.4 years and 14.8 months, respectively; 85.1% of the patients were women. The average total radiographic scores at baseline and at 3 years of disease were 2.4 and 5.7, respectively. In the final reduced multivariable model, adjusting for age, sex, anti-cyclic citrullinated peptide antibody positivity, and the presence of radiographic damage at baseline, the total radiographic score at 3 years disease in patients with osteopenia/osteoporosis of the femoral neck was twice that in patients with normal bone density, and the difference was statistically significant (P = 0.0084). No association between lumbar spine osteopenia/osteoporosis and radiographic score was found. Our findings suggest that reduced generalized BMD may be a predictor of future radiographic damage and support the hypothesis that radiographic damage and reduced generalized BMD in RA patients may share a common pathogenic mechanism.

  20. Neospora caninum in Axis Deer ( Axis axis ) and Fallow Deer ( Dama dama ) in Northern Mexico.

    PubMed

    De La Torre, Jose R; Bautista-Piña, Christian; Alfonso Ortega-S, J; Cantu-Covarruvias, Antonio; Genoveva Alvarez-Ojeda, Maria; Romero-Salas, Dora; Henke, Scott E; Hilton, Clayton D; Hewitt, David G; De Young, Randy W; Campbell, Tyler A; Bryant, Fred C

    2017-01-01

    Serum samples from 18 axis deer ( Axis axis ) and 19 fallow deer ( Dama dama ) were analyzed with an enzyme-linked immunosorbent assay for Neospora caninum antibodies. Two axis (11%) and two fallow deer (11%) were positive for N. caninum antibodies.

  1. An Anatomic Study on Whether the Immature Patella is Centered on an Anteroposterior Radiograph.

    PubMed

    Kyriakedes, James C; Liu, Raymond W

    2017-03-01

    In the operating room, after first obtaining a proper lateral radiograph with the condyles superimposed, a 90-degree rotation of the intraoperative fluoroscopy unit does not always produce an anteroposterior (AP) image with the patella centered. The orthogonality of these 2 views has not been well determined in children. This study was comprised of a radiographic group (35 knees) and a cadaveric group (59 knees). Both cadaveric and clinical images were obtained by resting or positioning the femur with the posterior condyles overlapped, and then taking an orthogonal AP image. Centering of the patella was calculated and multiple regression analysis was performed to determine the relationship between patellar centering and age, sex, ethnicity, mechanical lateral distal femoral angle (mLDFA), medial proximal tibial angle (MPTA), and contralateral centering. Mean patellar centering, expressed as the lateral position of the patella with respect to the total condylar width, was 0.08±0.10 in the radiographic group and 0.06±0.03 in the cadaveric group. Positive (lateral) patellar centering in 1 knee had a statistically significant correlation with positive patellar centering in the contralateral knee in both the radiographs and the cadavers. In the radiographic group, there was a statistically significant correlation between femoral varus and valgus deformities and positive patellar centering. In the cadaveric group, there was a statistically significant correlation between tibial valgus and negative (medial) patellar centering. The patella in an immature knee is rarely perfectly centered on a true AP image, and is usually seated slightly laterally within the femoral condyles. Obtaining a true AP intraoperative radiograph is critical to analyzing and correcting valgus and varus deformities, and in the proper placement of implants. When addressing knee deformity one should consider obtaining an AP view orthogonal either to a perfect lateral of the knee or orthogonal to the

  2. Factors affecting radiographers' organizational commitment.

    PubMed

    Akroyd, Duane; Jackowski, Melissa B; Legg, Jeffrey S

    2007-01-01

    A variety of factors influence employees' attitudes toward their workplace and commitment to the organization that employs them. However, these factors have not been well documented among radiologic technologists. To determine the predictive ability of selected organizational, leadership, work-role and demographic variables on organizational commitment for a national sample of radiographers. Three thousand radiographers registered by the American Registry of Radiologic Technologists working full time in clinical settings were surveyed by mail regarding their commitment to their employers, leadership within the organization that employs them, employer support and demographic information. Overall, radiographers were found to have only a moderate level of commitment to their employers. Among the factors that significantly affected commitment were the radiographer's educational level, perceived level of organizational support, role clarity and organizational leadership. The results of this study could provide managers and supervisors with insights on how to empower and challenge radiographers and offer opportunities that will enhance radiographers' commitment to the organization, thus reducing costly turnover and improving employee performance.

  3. Dual-modal photoacoustic and ultrasound imaging of dental implants

    NASA Astrophysics Data System (ADS)

    Lee, Donghyun; Park, Sungjo; Kim, Chulhong

    2018-02-01

    Dental implants are common method to replace decayed or broken tooth. As the implant treatment procedures varies according to the patients' jawbone, bone ridge, and sinus structure, appropriate examinations are necessary for successful treatment. Currently, radiographic examinations including periapical radiology, panoramic X-ray, and computed tomography are commonly used for diagnosing and monitoring. However, these radiographic examinations have limitations in that patients and operators are exposed to radioactivity and multiple examinations are performed during the treatment. In this study, we demonstrated photoacoustic (PA) and ultrasound (US) combined imaging of dental implant that can lower the total amount of absorbed radiation dose in dental implant treatment. An acoustic resolution PA macroscopy and a clinical PA/US system was used for dental implant imaging. The acquired dual modal PA/US imaging results support that the proposed photoacoustic imaging strategy can reduce the radiation dose rate during dental implant treatment.

  4. Factors affecting femoral rotational angle based on the posterior condylar axis in gap-based navigation-assisted total knee arthroplasty for valgus knee.

    PubMed

    Lee, Sung-Sahn; Lee, Yong-In; Kim, Dong-Uk; Lee, Dae-Hee; Moon, Young-Wan

    2018-01-01

    Achieving proper rotational alignment of the femoral component in total knee arthroplasty (TKA) for valgus knee is challenging because of lateral condylar hypoplasia and lateral cartilage erosion. Gap-based navigation-assisted TKA enables surgeons to determine the angle of femoral component rotation (FCR) based on the posterior condylar axis. This study evaluated the possible factors that affect the rotational alignment of the femoral component based on the posterior condylar axis. Between 2008 and 2016, 28 knees were enrolled. The dependent variable for this study was FCR based on the posterior condylar axis, which was obtained from the navigation system archives. Multiple regression analysis was conducted to identify factors that might predict FCR, including body mass index (BMI), Kellgren-Lawrence grade (K-L grade), lateral distal femoral angles obtained from the navigation system and radiographs (NaviLDFA, XrayLDFA), hip-knee-ankle (HKA) axis, lateral gap under varus stress (LGVS), medial gap under valgus stress (MGVS), and side-to-side difference (STSD, MGVS - LGVS). The mean FCR was 6.1° ± 2.0°. Of all the potentially predictive factors evaluated in this study, only NaviLDFA (β = -0.668) and XrayLDFA (β = -0.714) predicted significantly FCR. The LDFAs, as determined using radiographs and the navigation system, were both predictive of the rotational alignment of the femoral component based on the posterior condylar axis in gap-based TKA for valgus knee. A 1° increment with NaviLDFA led to a 0.668° decrement in FCR, and a 1° increment with XrayLDFA led to a 0.714° decrement. This suggests that symmetrical lateral condylar hypoplasia of the posterior and distal side occurs in lateral compartment end-stage osteoarthritis with valgus deformity.

  5. Use of a compact range approach to evaluate rf and dual-mode missiles

    NASA Astrophysics Data System (ADS)

    Willis, Kenneth E.; Weiss, Yosef

    2000-07-01

    This paper describes a hardware-in-the-loop (HWIL) system developed for testing Radio Frequency (RF), Infra-Red (IR), and Dual-Mode missile seekers. The system consists of a unique hydraulic five-axis (three seeker axes plus two target axes) Flight Motion Table (FMT), an off-axis parabolic reflector, and electronics required to generate the signals to the RF feeds. RF energy that simulates the target is fed into the reflector from three orthogonal feeds mounted on the inner target axis, at the focal point area of the parabolic reflector. The parabolic reflector, together with the three RF feeds (the Compact Range), effectively produces a far-field image of the target. Both FMT target axis motion and electronic control of the RF beams (deflection) modify the simulated line-of-sight target angles. Multiple targets, glint, multi-path, ECM, and clutter can be introduced electronically. To evaluate dual-mode seekers, the center section of the parabolic reflector is replaced with an IR- transparent, but RF-reflective section. An IR scene projector mounts to the FMT target axes, with its image focused on the intersection of the FMT seeker axes. The system eliminates the need for a large anechoic chamber and 'Target Wall' or target motion system used with conventional HWIL systems. This reduces acquisition and operating costs of the facility.

  6. Radiographic artifacts.

    PubMed

    Kirberger, R M; Roos, C J

    1995-06-01

    Radiographic artifacts commonly occur, particularly with hand processing. The artifacts may originate between the X-ray tube and the cassette as extraneous material on the patient or contamination of positioning aids, or result from debris within the cassette, or damage to, or staining of the screens. These artifacts are white to grey, may have a constant or different position on follow-up radiographs, and their size and shape are reflective of the inciting cause. A number of artifacts may occur in the darkroom during handling, developing, fixing and drying of the film. White to shiny artifacts are caused by the contamination of films with fixer, inability of developer to reach parts of the film or loss of emulsion from the developed film. Black artifacts result from improper handling or storage of films, resulting in exposure to light, or from pressure marks or static electricity discharges. Dropped levels of hand-processing chemicals may result in a variety of tide-marks on films. Most radiographic artifacts can be prevented by proper storage and handling of films and by optimal darkroom technique.

  7. Construction of anthropomorphic hybrid, dual-lattice voxel models for optimizing image quality and dose in radiography

    NASA Astrophysics Data System (ADS)

    Petoussi-Henss, Nina; Becker, Janine; Greiter, Matthias; Schlattl, Helmut; Zankl, Maria; Hoeschen, Christoph

    2014-03-01

    In radiography there is generally a conflict between the best image quality and the lowest possible patient dose. A proven method of dosimetry is the simulation of radiation transport in virtual human models (i.e. phantoms). However, while the resolution of these voxel models is adequate for most dosimetric purposes, they cannot provide the required organ fine structures necessary for the assessment of the imaging quality. The aim of this work is to develop hybrid/dual-lattice voxel models (called also phantoms) as well as simulation methods by which patient dose and image quality for typical radiographic procedures can be determined. The results will provide a basis to investigate by means of simulations the relationships between patient dose and image quality for various imaging parameters and develop methods for their optimization. A hybrid model, based on NURBS (Non Linear Uniform Rational B-Spline) and PM (Polygon Mesh) surfaces, was constructed from an existing voxel model of a female patient. The organs of the hybrid model can be then scaled and deformed in a non-uniform way i.e. organ by organ; they can be, thus, adapted to patient characteristics without losing their anatomical realism. Furthermore, the left lobe of the lung was substituted by a high resolution lung voxel model, resulting in a dual-lattice geometry model. "Dual lattice" means in this context the combination of voxel models with different resolution. Monte Carlo simulations of radiographic imaging were performed with the code EGS4nrc, modified such as to perform dual lattice transport. Results are presented for a thorax examination.

  8. SU-E-T-25: Real Time Simulator for Designing Electron Dual Scattering Foil Systems.

    PubMed

    Carver, R; Hogstrom, K; Price, M; Leblanc, J; Harris, G

    2012-06-01

    To create a user friendly, accurate, real time computer simulator to facilitate the design of dual foil scattering systems for electron beams on radiotherapy accelerators. The simulator should allow for a relatively quick, initial design that can be refined and verified with subsequent Monte Carlo (MC) calculations and measurements. The simulator consists of an analytical algorithm for calculating electron fluence and a graphical user interface (GUI) C++ program. The algorithm predicts electron fluence using Fermi-Eyges multiple Coulomb scattering theory with a refined Moliere formalism for scattering powers. The simulator also estimates central-axis x-ray dose contamination from the dual foil system. Once the geometry of the beamline is specified, the simulator allows the user to continuously vary primary scattering foil material and thickness, secondary scattering foil material and Gaussian shape (thickness and sigma), and beam energy. The beam profile and x-ray contamination are displayed in real time. The simulator was tuned by comparison of off-axis electron fluence profiles with those calculated using EGSnrc MC. Over the energy range 7-20 MeV and using present foils on the Elekta radiotherapy accelerator, the simulator profiles agreed to within 2% of MC profiles from within 20 cm of the central axis. The x-ray contamination predictions matched measured data to within 0.6%. The calculation time was approximately 100 ms using a single processor, which allows for real-time variation of foil parameters using sliding bars. A real time dual scattering foil system simulator has been developed. The tool has been useful in a project to redesign an electron dual scattering foil system for one of our radiotherapy accelerators. The simulator has also been useful as an instructional tool for our medical physics graduate students. © 2012 American Association of Physicists in Medicine.

  9. The burden of non-radiographic axial spondyloarthritis.

    PubMed

    Boonen, Annelies; Sieper, Joachim; van der Heijde, Désirée; Dougados, Maxime; Bukowski, Jack F; Valluri, Satish; Vlahos, Bonnie; Kotak, Sameer

    2015-04-01

    To identify patients earlier, new classification criteria have been introduced for axial spondyloarthritis (axSpA). Patients who satisfy the clinical or imaging criteria for axSpA in the absence of definite sacroiliac joint changes on pelvic x-rays are classified as having non-radiographic axSpA. Although the burden associated with radiographic axSpA (i.e., ankylosing spondylitis) has been extensively studied, the impact of non-radiographic disease is not well understood. The purpose of this review is to provide an overview of the burden of illness in non-radiographic axSpA, including epidemiology and effects on patients׳ functioning and health-related quality of life (HR-QoL). A PubMed search was performed using relevant key words (e.g., "spondyloarthritis," "ankylosing spondylitis," "epidemiology," and "quality of life") to examine literature published from 2003 to 2013. Studies conducted to date suggest that radiographic progression is detected in approximately 10% of patients with non-radiographic axSpA over 2 years. Differences between patients with non-radiographic and radiographic axSpA were found in age, symptom duration, and gender distribution. Although less inflammation (i.e., lower C-reactive protein levels and less spinal inflammation on MRI) and less impairment in spinal mobility are observed in non-radiographic than in radiographic axSpA, the 2 conditions pose a similar burden in terms of disease activity, physical function, HR-QoL impairment. Patients with non-radiographic axSpA are more frequently female. Although patients with non-radiographic axSpA have shorter disease duration and lack radiological changes, they demonstrate a substantial burden of illness, with self-reported disease activity and functional impairments comparable to those found in patients with radiographic disease. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. Analysis of polyethylene wear in plain radiographs

    PubMed Central

    2009-01-01

    Background and purpose Two-dimensional computerized radiographic techniques are frequently used to measure in vivo polyethylene (PE) wear after total hip arthroplasty (THA), and several variables in the clinical set-up may influence the amount of wear that is measured. We compared the repeatability and concurrent validity of linear PE wear on plain radiographs using the same software but a different number of radiographs. Methods We used either 1, 2, or 6 anteroposterior (AP) hip radiographs of 11 patients from a clinical THA series with 12 years of follow-up, and measured the PE wear with the software PolyWare 3D Pro. Repeatability within and concurrent validity between the different numbers of radiograph strategies were assessed using limits of agreement (LOAs) and bias. Results Observed median wear (range) in mm was 3.4 (1.6–4.6), 2.3 (0.7–4.9), and 4.0 (2.6–6.2) for the 1-, 2-, and 6-radiograph strategies. For repeatability, no bias (p > 0.41) was observed. LOAs around the bias were ± 0.6, ± 0.4, and ± 1.2 mm for the 1-, 2-, and 6-radiograph strategies. For concurrent validity, a bias (± LOA) between all pairwise comparisons was observed (p < 0.02) with 0.8 mm (± 2.5) between the 1- and 2-radiograph strategies, 1.0 mm (± 2.2) between the 1- and 6-radiograph strategies, and 1.8 mm (± 1.2) between the 2- and 6-radiograph strategies. Interpretation The number of radiographs used for wear measurement with a shadow-casting analysis method on plain AP radiographs influences the amount of linear wear measured. Results of PE wear obtained with PolyWare in studies using a different number of radiographs are not comparable. PMID:19995318

  11. Radiographic morphometry and densitometry predict strength of cadaveric proximal humeri more reliably than age and DXA scan density.

    PubMed

    Skedros, John G; Knight, Alex N; Pitts, Todd C; O'Rourke, Peter J; Burkhead, Wayne Z

    2016-02-01

    Methods are needed for identifying poorer quality cadaver proximal humeri to ensure that they are not disproportionately segregated into experimental groups for fracture studies. We hypothesized that measurements made from radiographs of cadaveric proximal humeri are stronger predictors of fracture strength than chronological age or bone density values derived from dual-energy x-ray absorptiometry (DXA) scans. Thirty-three proximal humeri (range: 39-78 years) were analyzed for: (1) bone mineral density (BMD, g/cm(2)) using DXA, (2) bulk density (g/cm(3)) using DXA and volume displacement, (3) regional bone density in millimeters of aluminum (mmAl) using radiographs, and (4) regional mean (medial+lateral) cortical thickness and cortical index (CI) using radiographs. The bones were then fractured simulating a fall. Strongest correlations with ultimate fracture load (UFL) were: mean cortical thickness at two diaphyseal locations (r = 0.71; p < 0.001), and mean mmAl in the humeral head (r = 0.70; p < 0.001). Weaker correlations were found between UFL and DXA-BMD (r = 0.60), bulk density (r = 0.43), CI (r = 0.61), and age (r = -0.65) (p values <0.01). Analyses between UFL and the product of any two characteristics showed six combinations with r-values >0.80, but none included DXA-derived density, CI, or age. Radiographic morphometric and densitometric measurements from radiographs are therefore stronger predictors of UFL than age, CI, or DXA-derived density measurements. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  12. Tarsal navicular stress fractures: radiographic evaluation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Pavlov, H.; Torg, J.S.; Freiberger, R.H.

    1983-09-01

    Tarsal navicular stress fractures are a potential source of disabling foot pain in physically active individuals. The diagnosis of tarsal navicular stress fracture requires a high index of clinical and radiographic suspicion because the fracture is only rarely evident on routine radiographs or standard tomograms. The radiographic diagnosis of a tarsal navicular stress fracture may require anatomic anteroposterior tomograms or a radionuclide bone scan with plantar views. Radiographic examinations of 23 fractures in 21 patients are evaluated.

  13. Validation of a new radiographic protocol for Asian elephant feet and description of their radiographic anatomy.

    PubMed

    Mumby, C; Bouts, T; Sambrook, L; Danika, S; Rees, E; Parry, A; Rendle, M; Masters, N; Weller, R

    2013-10-05

    Foot problems are extremely common in elephants and radiography is the only imaging method available but the radiographic anatomy has not been described in detail. The aims of this study were to develop a radiographic protocol for elephant feet using digital radiography, and to describe the normal radiographic anatomy of the Asian elephant front and hind foot. A total of fifteen cadaver foot specimens from captive Asian elephants were radiographed using a range of projections and exposures to determine the best radiographic technique. This was subsequently tested in live elephants in a free-contact setting. The normal radiographic anatomy of the Asian elephant front and hind foot was described with the use of three-dimensional models based on CT reconstructions. The projection angles that were found to be most useful were 65-70° for the front limb and 55-60° in the hind limb. The beam was centred 10-15 cm proximal to the cuticle in the front and 10-15 cm dorsal to the plantar edge of the sole in the hind foot depending on the size of the foot. The protocol developed can be used for larger-scale diagnostic investigations of captive elephant foot disorders, while the normal radiographic anatomy described can improve the diagnostic reliability of elephant feet radiography.

  14. Assessment of risk of femoral neck fracture with radiographic texture parameters: a retrospective study.

    PubMed

    Thevenot, Jérôme; Hirvasniemi, Jukka; Pulkkinen, Pasi; Määttä, Mikko; Korpelainen, Raija; Saarakkala, Simo; Jämsä, Timo

    2014-07-01

    To investigate whether femoral neck fracture can be predicted retrospectively on the basis of clinical radiographs by using the combined analysis of bone geometry, textural analysis of trabecular bone, and bone mineral density (BMD). Formal ethics committee approval was obtained for the study, and all participants gave informed written consent. Pelvic radiographs and proximal femur BMD measurements were obtained in 53 women aged 79-82 years in 2006. By 2012, 10 of these patients had experienced a low-impact femoral neck fracture. A Laplacian-based semiautomatic custom algorithm was applied to the radiographs to calculate the texture parameters along the trabecular fibers in the lower neck area for all subjects. Intra- and interobserver reproducibility was calculated by using the root mean square average coefficient of variation to evaluate the robustness of the method. The best predictors of hip fracture were entropy (P = .007; reproducibility coefficient of variation < 1%), the neck-shaft angle (NSA) (P = .017), and the BMD (P = .13). For prediction of fracture, the area under the receiver operating characteristic curve was 0.753 for entropy, 0.608 for femoral neck BMD, and 0.698 for NSA. The area increased to 0.816 when entropy and NSA were combined and to 0.902 when entropy, NSA, and BMD were combined. Textural analysis of pelvic radiographs enables discrimination of patients at risk for femoral neck fracture, and our results show the potential of this conventional imaging method to yield better prediction than that achieved with dual-energy x-ray absorptiometry-based BMD. The combination of the entropy parameter with NSA and BMD can further enhance predictive accuracy. © RSNA, 2014.

  15. Digital radiographic imaging transfer: comparison with plain radiographs.

    PubMed

    Averch, T D; O'Sullivan, D; Breitenbach, C; Beser, N; Schulam, P G; Moore, R G; Kavoussi, L R

    1997-04-01

    Advances in digital imaging and computer display technology have allowed development of clinical teleradiographic systems. There are limited data assessing the effectiveness of such systems when applied to urologic pathology. In an effort to appraise the effectiveness of teleradiology in identifying renal calculi, the accuracy of findings on transmitted radiographic images were compared with those made when viewing the actual plain film. Plain films (KUB) were obtained from 26 patients who presented to the radiology department to rule out urinary calculous disease. The films were digitalized by a radiograph scanner into ARCNEMA-2 file format, compressed by a NASA algorithm, and transferred via a 28.8-kbps modern over standard telephone lines to a remote section 25 miles away, where they were decompressed and viewed on a 1600 x 1200-pixel monitor. Two attending urologists and two endourologic fellows were randomized to read either the transmitted image or the original radiograph with minimal clinical history provided. Of the 26 plain radiographic films, 24 were correctly interpreted by the fellows and 25 by the attending physicians (92% and 96% accuracy, respectively) for a total accuracy of 94% with no statistical difference (p = 0.16). After compression, all but one of the digital images were transferred successfully. The attending physicians correctly interpreted 24 of the 25 digital images (96%), whereas the fellows were correct on 21 interpretations (84%), resulting in a total 90% accuracy with a significant difference between the groups (p < or = 0.04). Overall, no statistical difference between the interpretations of the plain film and the digital image was revealed (p = 0.21). Using available technology, KUB images can be transmitted to a remote site, and the location of a stone can be determined correctly. Higher accuracy is demonstrated by experienced surgeons.

  16. Spatial resolution measurements of the advanced radiographic capability x-ray imaging system at energies relevant to Compton radiography

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hall, G. N.; Izumi, N.; Landen, O. L.

    2016-08-03

    Compton radiography provides a means to measure the integrity, ρR and symmetry of the DT fuel in an inertial confinement fusion implosion near peak compression. Upcoming experiments at the National Ignition Facility will use the ARC (Advanced Radiography Capability) laser to drive backlighter sources for Compton radiography experiments, and will use the newly commissioned AXIS (ARC X-ray Imaging System) instrument as the detector. AXIS uses a dual-MCP (micro channel plate) to provide gating and high DQE at the 40–200keV x-ray range required for Compton radiography, but introduces many effects that contribute to the spatial resolution. Here, experiments were performed atmore » energies relevant to Compton radiography to begin characterization of the spatial resolution of the AXIS diagnostic.« less

  17. AXIS - A High Angular Resoltuion X-ray Probe Concept Study

    NASA Astrophysics Data System (ADS)

    Mushotzky, Richard; AXIS Study Team

    2018-01-01

    AXIS is a probe-class concept under study to the 2020 Decadal survey. AXIS will extend and enhance the science of high angular resolution x-ray imaging and spectroscopy in the next decade with ~0.3" angular resolution over a 7' radius field of view and an order of magnitude more collecting area than Chandra in the 0.3-12 keV band with a cost consistent with a probe.These capabilities enable major advances in a wide range of science such as: (1) measuring the event horizon scale structure in AGN accretion disks and the spins of supermassive black holes through observations of gravitationally-microlensed quasars; (ii) determining AGN and starburst feedback in galaxies and galaxy clusters through direct imaging of winds and interaction of jets and via spatially resolved imaging of galaxies at high-z; (iii) fueling of AGN by probing the Bondi radius of over 20 nearby galaxies; (iv) hierarchical structure formation and the SMBH merger rate through measurement of the occurrence rate of dual AGN and occupation fraction of SMBHs; (v) advancing SNR physics and galaxy ecology through large detailed samples of SNR in nearby galaxies; (vi) measuring the Cosmic Web through its connection to cluster outskirts. With a nominal 2028 launch, AXIS benefits from natural synergies with the ELTs, LSST, ALMA, WFIRST and ATHENA. AXIS utilizes breakthroughs in the construction of lightweight X-ray optics from mono-crystalline silicon blocks, and developments in the fabrication of large format, small pixel, high readout rate detectors allowing a robust and cost effective design. The AXIS team welcomes input and feedback from the community in preparation for the 2020 Decadal review.

  18. Study of the transverse beam motion in the DARHT Phase II accelerator

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chen, Yu-Jiuan; Fawley, W M; Houck, T L

    1998-08-20

    The accelerator for the second-axis of the Dual Axis Radiographic Hydrodynamic Test (DARHT) facility will accelerate a 4-kA, 3-MeV, 2--µs long electron current pulse to 20 MeV. The energy variation of the beam within the flat-top portion of the current pulse is (plus or equal to) 0.5%. The performance of the DARHT Phase II radiographic machine requires the transverse beam motion to be much less than the beam spot size which is about 1.5 mm diameter on the x-ray converter. In general, the leading causes of the transverse beam motion in an accelerator are the beam breakup instability (BBU) andmore » the corkscrew motion. We have modeled the transverse beam motion in the DARHT Phase II accelerator with various magnetic tunes and accelerator cell configurations by using the BREAKUP code. The predicted sensitivity of corkscrew motion and BBU growth to different tuning algorithms will be presented.« less

  19. Improved motor control method with measurements of fiber optics gyro (FOG) for dual-axis rotational inertial navigation system (RINS).

    PubMed

    Song, Tianxiao; Wang, Xueyun; Liang, Wenwei; Xing, Li

    2018-05-14

    Benefiting from frame structure, RINS can improve the navigation accuracy by modulating the inertial sensor errors with proper rotation scheme. In the traditional motor control method, the measurements of the photoelectric encoder are always adopted to drive inertial measurement unit (IMU) to rotate. However, when carrier conducts heading motion, the inertial sensor errors may no longer be zero-mean in navigation coordinate. Meanwhile, some high-speed carriers like aircraft need to roll a certain angle to balance the centrifugal force during the heading motion, which may result in non-negligible coupling errors, caused by the FOG installation errors and scale factor errors. Moreover, the error parameters of FOG are susceptible to the temperature and magnetic field, and the pre-calibration is a time-consuming process which is difficult to completely suppress the FOG-related errors. In this paper, an improved motor control method with the measurements of FOG is proposed to address these problems, with which the outer frame can insulate the carrier's roll motion and the inner frame can simultaneously achieve the rotary modulation on the basis of insulating the heading motion. The results of turntable experiments indicate that the navigation performance of dual-axis RINS has been significantly improved over the traditional method, which could still be maintained even with large FOG installation errors and scale factor errors, proving that the proposed method can relax the requirements for the accuracy of FOG-related errors.

  20. Chevron-type medial malleolar osteotomy: a functional, radiographic and quantitative T2-mapping MRI analysis.

    PubMed

    Lamb, Joshua; Murawski, Christopher D; Deyer, Timothy W; Kennedy, John G

    2013-06-01

    The purpose of this study was to retrospectively evaluate a large series of patients for functional, radiographic and MRI outcomes after a Chevron-type medial malleolar osteotomy. Sixty-two patients underwent a Chevron-type medial malleolar osteotomy with a median follow-up of 34.5 months. Standard digital radiographs were used to determine bony union and the angle of the osteotomy relative to the longitudinal axis of the tibia. Morphologic and quantitative T2-mapping MRI was also analysed in 32 patients. Fifty-eight patients (94 %) reported being asymptomatic at the site of the medial malleolar osteotomy. The median time to healing on standard radiograph was 6 weeks (range, 4-6 weeks) with an angle of 31.7° ± 6.9°. Quantitative T2-mapping MRI analysis demonstrated that the deep half of interface repair tissue had relaxation times that were not significantly different from normal tibial cartilage. In contrast, interface repair tissue in the superficial half demonstrated significant prolongation from normal relaxation time values, indicating a more fibrocartilaginous repair. Four patients (6 %) reported pain post-operatively. A Chevron-type medial malleolar osteotomy demonstrates satisfactory healing and fixation, with fibrocartilaginous tissue evident superficially at the osteotomy interface. Further investigation is warranted in the form of longitudinal study to assess the long-term outcomes of medial malleolar osteotomy.

  1. 21 CFR 892.1840 - Radiographic film.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Radiographic film. 892.1840 Section 892.1840 Food... DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1840 Radiographic film. (a) Identification. Radiographic film is a device that consists of a thin sheet of radiotransparent material coated on one or both...

  2. 21 CFR 892.1840 - Radiographic film.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Radiographic film. 892.1840 Section 892.1840 Food... DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1840 Radiographic film. (a) Identification. Radiographic film is a device that consists of a thin sheet of radiotransparent material coated on one or both...

  3. 21 CFR 892.1840 - Radiographic film.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Radiographic film. 892.1840 Section 892.1840 Food... DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1840 Radiographic film. (a) Identification. Radiographic film is a device that consists of a thin sheet of radiotransparent material coated on one or both...

  4. 21 CFR 892.1840 - Radiographic film.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Radiographic film. 892.1840 Section 892.1840 Food... DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1840 Radiographic film. (a) Identification. Radiographic film is a device that consists of a thin sheet of radiotransparent material coated on one or both...

  5. 21 CFR 892.1840 - Radiographic film.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radiographic film. 892.1840 Section 892.1840 Food... DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1840 Radiographic film. (a) Identification. Radiographic film is a device that consists of a thin sheet of radiotransparent material coated on one or both...

  6. An investigation of thoracic and lumbar cancellous vertebral architecture using power-spectral analysis of plain radiographs*

    PubMed Central

    Buck, AM; Price, RI; Sweetman, IM; Oxnard, CE

    2002-01-01

    The internal architecture of the vertebral bodies spanning the levels T1 to L5 in seven male columns was studied using mammographic-resolution radiographs of 2.5-mm-thick planar parasagittal slices. The overlapping radiographic shadows of vertebral trabeculae combined in the image to form a series of ‘elements’, broadly representative of the cancellous structure. The orientations and sizes of these elements were analysed by applying the Fast Fourier transform (FFT) to the digitized radiographic images. Elements aligned in the ‘vertical’ orientation, along the long axis of the column, were the most prominent for all vertebral levels. The relative prominence of horizontal to vertical elements was generally constant along the column below T5. In contrast, the relative prominence of oblique to vertical elements declined in the cranio-caudal direction, particularly in individuals aged ≥ 60 years. The ratio of ‘large’ (x > 0.3 mm) to ‘small’ (0.15 mm ≤ x ≤ 0.3 mm) elements was unchanged cranio-caudally in specimens < 60 years. However, in individuals ≥ 60 years, large elements increased in relative prominence in the caudal direction. These results suggest that a basic orthogonal pattern of trabeculae is found along the male human spine, regardless of differences in vertebral body size. Power-spectral analysis is shown to yield information summarizing the predominant orientations and sizes of radiographically rendered architectural elements of vertebral cancellous bone, to define the effects of ageing on architecture, and to identify broad structural differences between vertebral levels in the adult male spine. PMID:12090391

  7. Radiographic cup anteversion measurement corrected from pelvic tilt.

    PubMed

    Wang, Liao; Thoreson, Andrew R; Trousdale, Robert T; Morrey, Bernard F; Dai, Kerong; An, Kai-Nan

    2017-11-01

    The purpose of this study was to develop a novel technique to improve the accuracy of radiographic cup anteversion measurement by correcting the influence of pelvic tilt. Ninety virtual total hip arthroplasties were simulated from computed tomography data of 6 patients with 15 predetermined cup orientations. For each simulated implantation, anteroposterior (AP) virtual pelvic radiographs were generated for 11 predetermined pelvic tilts. A linear regression model was created to capture the relationship between radiographic cup anteversion angle error measured on AP pelvic radiographs and pelvic tilt. Overall, nine hundred and ninety virtual AP pelvic radiographs were measured, and 90 linear regression models were created. Pearson's correlation analyses confirmed a strong correlation between the errors of conventional radiographic cup anteversion angle measured on AP pelvic radiographs and the magnitude of pelvic tilt (P < 0.001). The mean of 90 slopes and y-intercepts of the regression lines were -0.8 and -2.5°, which were applied as the general correction parameters for the proposed tool to correct conventional cup anteversion angle from the influence of pelvic tilt. The current method proposes to measure the pelvic tilt on a lateral radiograph, and to use it as a correction for the radiographic cup anteversion measurement on an AP pelvic radiograph. Thus, both AP and lateral pelvic radiographs are required for the measurement of pelvic posture-integrated cup anteversion. Compared with conventional radiographic cup anteversion, the errors of pelvic posture-integrated radiographic cup anteversion were reduced from 10.03 (SD = 5.13) degrees to 2.53 (SD = 1.33) degrees. Pelvic posture-integrated cup anteversion measurement improves the accuracy of radiographic cup anteversion measurement, which shows the potential of further clarifying the etiology of postoperative instability based on planar radiographs. Copyright © 2017 IPEM. Published by Elsevier Ltd

  8. Dual-Actuator Active Vibration-Control System

    NASA Technical Reports Server (NTRS)

    Kascak, Albert F.; Kiraly, Louis J.; Montague, Gerald T.; Palazzolo, Alan B.; Manchala, Daniel

    1994-01-01

    Dual-actuator active vibration-control (DAAVC) system is developmental system of type described in "Active Vibration Dampers for Rotating Machinery" (LEW-15427). System features sensors and actuators positioned and oriented at bearings to measure and counteract vibrations of shaft along either of two axes perpendicular to axis of rotation. Effective in damping vibrations of helicopter-engine test stand, making it safer to operate engine at speeds near and above first resonance of engine/test-stand system. Opens new opportunities for engine designers to draw more power from engine, and concept applicable to other rotating machines.

  9. Does the radiologically isolated syndrome exist? A dual-task cost pilot study.

    PubMed

    Dattola, Vincenzo; Logiudice, Anna Lisa; Bonanno, Lilla; Famà, Fausto; Milardi, Demetrio; Chillemi, Gaetana; D'Aleo, Giangaetano; Marino, Silvia; Calabrò, Rocco Salvatore; Russo, Margherita

    2017-11-01

    Simultaneous performance of motor and cognitive tasks may compete for common brain network resources in aging or patients with some neurological diseases, suggesting the occurrence of a cognitive-motor interference. While this phenomenon has been well described for multiple sclerosis (MS) patients, it never has been tested on asymptomatic subject with magnetic resonance imaging (MRI) findings suggestive of demyelinating disease (i.e., radiologically isolated syndrome: RIS). In this pilot study, 10 RIS subjects and 10 sex/age-matched healthy controls were tested by means of static posturography under eyes opened (single-task trial) and while performing two different cognitive tasks (semantic modified word list generation for first dual-task trial and phonemic semantic modified word list generation for second dual-task trial), to estimate the dual-task cost (DTC) of standing balance. In our sample, under cognitive interference (without any substantial differences between semantic and phonemic modified word list generation), the RIS group showed significance differences in CoP (center of pressure) total sway area, ellipse eccentricity, CoP sway path length, CoP median sway velocity along the AP (anteroposterior) axis and along the ML (mediolateral) axis, reflecting a higher negative DTC respect to healthy subjects (which have simply shown a statistical trend, failing to reach a significance, in some trials). The phenomenon of cognitive-motor interference might be unmasked by a dual-task posturography in RIS subjects, too. We hypothesize that this approach could be useful to early reveal the presence of a demyelinating disease and to reach a MS diagnosis in subjects otherwise classified as RIS.

  10. Errors in radiographic interpretation made by veterinary students.

    PubMed

    Lamb, C R; Pfeiffer, D U; Mantis, P

    2007-01-01

    As a means of identifying student weaknesses in radiographic interpretation that could be used as foci for teaching, a cohort of 96 students joining the final-year radiology rotation were randomly allocated to one of three radiographic interpretation quizzes, each based on radiographs of small-animal patients together with the signalment and a brief, relevant history. Students' quiz scores were analyzed by multiple logistic regression, using an outcome variable with the score for each item as numerator and maximum possible mark as denominator. Students' median quiz score was 49% of the maximum (range 23-80%). Students were more likely to gain a mark for items based on abnormal radiographs than for those based on normal radiographs (odds ratio 3.4, p < 0.001). Skeletal radiographs were associated with lower scores (OR 0.75, p = 0.03). The fewest marks were awarded for interpretation of a radiograph of a normal canine stifle and interpretation of a radiograph of a normal canine pelvis; these items were misinterpreted as abnormal by 86% and 80% of the students, respectively. Students' tendency to over-interpret normal radiographs may reflect a lack of knowledge of radiographic anatomy or an unrealistically high expectation that the radiographs are abnormal.

  11. Radiographic landmarks for locating the femoral origin of the superficial medial collateral ligament.

    PubMed

    Hartshorn, Timothy; Otarodifard, Karimdad; White, Eric A; Hatch, George F Rick

    2013-11-01

    Little has been written about the use of radiographic landmarks for locating the origin of the superficial medial collateral ligament (sMCL). A standardized radiographic landmark for the sMCL origin using intraoperative fluoroscopic imaging may be of value in aiding the surgeon in accurate femoral tunnel placement in the setting of extensive soft tissue disruption and bony attrition. To determine a reproducible radiographic landmark that will assist in correct femoral tunnel placement in sMCL repair and reconstruction. Descriptive laboratory study. Ten fresh-frozen unmatched human cadaveric knees were dissected, and the origin of the sMCL was exposed. A 2-mm metallic marker was then placed at the center of the femoral origin of the sMCL. True lateral fluoroscopically assisted digital radiographs were obtained of the knee with the posterior and distal femoral condyles overlapping in a standardized fashion. With the use of computer software, reference lines were drawn on the images, creating 4 quadrants. Two independent examiners performed quantitative measurements of the sMCL origin in relation to this axis and to the Blumensaat line. Mean measurements showed the sMCL origin to be closely related to the intersection point of the Blumensaat line and a line drawn distally from the posterior femoral cortex on a true lateral radiograph. The sMCL origin was found at a mean point 1.6 ± 4.3 mm posterior and 4.9 ± 2.1 mm proximal to the intersection of a line paralleling the posterior femoral cortex and a line drawn perpendicular to the posterior femoral cortical line, where it intersects the Blumensaat line. In 5 of 10 specimens, the center of the sMCL origin fell precisely on the Blumensaat line. The remaining specimens had sMCL origins anterior to the Blumensaat line. The femoral origin of the sMCL was found in the proximal and posterior quadrants in 8 of 10 specimens. With a relatively small amount of deviation, the sMCL origin can be consistently identified on a true

  12. Emittance Growth in the DARHT-II Linear Induction Accelerator

    DOE PAGES

    Ekdahl, Carl; Carlson, Carl A.; Frayer, Daniel K.; ...

    2017-10-03

    The dual-axis radiographic hydrodynamic test (DARHT) facility uses bremsstrahlung radiation source spots produced by the focused electron beams from two linear induction accelerators (LIAs) to radiograph large hydrodynamic experiments driven by high explosives. Radiographic resolution is determined by the size of the source spot, and beam emittance is the ultimate limitation to spot size. On the DARHT-II LIA, we measure an emittance higher than predicted by theoretical simulations, and even though this accelerator produces submillimeter source spots, we are exploring ways to improve the emittance. Some of the possible causes for the discrepancy have been investigated using particle-in-cell codes. Finally,more » the simulations establish that the most likely source of emittance growth is a mismatch of the beam to the magnetic transport, which can cause beam halo.« less

  13. Emittance Growth in the DARHT-II Linear Induction Accelerator

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ekdahl, Carl; Carlson, Carl A.; Frayer, Daniel K.

    The dual-axis radiographic hydrodynamic test (DARHT) facility uses bremsstrahlung radiation source spots produced by the focused electron beams from two linear induction accelerators (LIAs) to radiograph large hydrodynamic experiments driven by high explosives. Radiographic resolution is determined by the size of the source spot, and beam emittance is the ultimate limitation to spot size. On the DARHT-II LIA, we measure an emittance higher than predicted by theoretical simulations, and even though this accelerator produces submillimeter source spots, we are exploring ways to improve the emittance. Some of the possible causes for the discrepancy have been investigated using particle-in-cell codes. Finally,more » the simulations establish that the most likely source of emittance growth is a mismatch of the beam to the magnetic transport, which can cause beam halo.« less

  14. Radiographic bone loss in a Scottish non-smoking Type 1 Diabetes mellitus population; a Bitewing Radiographic Study.

    PubMed

    Plessas, Anastasios; Robertson, Douglas P; Hodge, Penny J

    2018-05-15

    The dental complications of uncontrolled diabetes include reduced salivary flow rate, candidiasis and periodontal manifestations. A recent meta-analysis concluded that diabetes patients have a significantly higher severity, but not extent, of destructive periodontal disease than non-diabetes people. The authors reported that most type-1 diabetes studies using dental radiographic data have not controlled for confounding factors such as smoking. The aim of this cross-sectional study was to compare radiographic alveolar bone loss between type 1 diabetes (T1DM) and non-diabetes (NDM) participants in a Scottish non-smoking population. Digital bitewing radiographs for 174 Scottish adult never or ex-smoker (> 5 years) participants (108 T1DM, 66 NDS), recruited from outpatient clinics throughout Greater Glasgow and Clyde, were included in the analysis. A single blinded, trained and calibrated examiner recorded the radiographic bone loss seen on bitewing radiographs using the digital screen caliper. The bone loss was measured as the distance between the cemento-enamel junction (CEJ) and the deepest radiographic alveolar bone margin interproximally of each tooth. T1DM participants had more radiographic alveolar bone loss throughout the all teeth measured (median:1.27 mm vs 1.06 mm, P < 0.001) and more than a two fold increase in the risk of having sites with ≥2 mm periodontal destruction (OR = 2.297, 95%CI 1.058-4.986, P = 0.036) compared with non-diabetes subjects. Patients suffering from type 1 diabetes are at higher risk of periodontitis even when controlling for multiple possible confounding factors and this difference can be detected on routine dental radiographs at an early stage. These data confirm radiographically the previously reported association between T1DM and periodontal bone loss. This article is protected by copyright. All rights reserved. © 2018 American Academy of Periodontology.

  15. Simulation results of corkscrew motion in DARHT-II

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chan, K. D.; Ekdahl, C. A.; Chen, Y. J.

    2003-01-01

    DARHT-II, the second axis of the Dual-Axis Radiographic Hydrodynamics Test Facility, is being commissioned. DARHT-II is a linear induction accelerator producing 2-microsecond electron beam pulses at 20 MeV and 2 kA. These 2-microsecond pulses will be chopped into four short pulses to produce time resolved x-ray images. Radiographic application requires the DARHT-II beam to have excellent beam quality, and it is important to study various beam effects that may cause quality degradation of a DARHT-II beam. One of the beam dynamic effects under study is 'corkscrew' motion. For corkscrew motion, the beam centroid is deflected off axis due to misalignmentsmore » of the solenoid magnets. The deflection depends on the beam energy variation, which is expected to vary by {+-}0.5% during the 'flat-top' part of a beam pulse. Such chromatic aberration will result in broadening of beam spot size. In this paper, we will report simulation results of our study of corkscrew motion in DARHT-II. Sensitivities of beam spot size to various accelerator parameters and the strategy for minimizing corkscrew motion will be described. Measured magnet misalignment is used in the simulation.« less

  16. Pediatric cervical spine in emergency: radiographic features of normal anatomy, variants and pitfalls.

    PubMed

    Adib, Omar; Berthier, Emeline; Loisel, Didier; Aubé, Christophe

    2016-12-01

    Injuries of the cervical spine are uncommon in children. The distribution of injuries, when they do occur, differs according to age. Young children aged less than 8 years usually have upper cervical injuries because of the anatomic and biomechanical properties of their immature spine, whereas older children, whose biomechanics more closely resemble those of adults, are prone to lower cervical injuries. In all cases, the pediatric cervical spine has distinct radiographic features, making the emergency radiological analysis of it difficult. Such features as hypermobility between C2 and C3, pseudospread of the atlas on the axis, pseudosubluxation, the absence of lordosis, anterior wedging of vertebral bodies, pseudowidening of prevertebral soft tissue and incomplete ossification of synchondrosis can be mistaken for traumatic injuries. The interpretation of a plain radiograph of the pediatric cervical spine following trauma must take into account the age of the child, the location of the injury and the mechanism of trauma. Comprehensive knowledge of the specific anatomy and biomechanics of the childhood spine is essential for the diagnosis of suspected cervical spine injury. With it, the physician can, on one hand, differentiate normal physes or synchondroses from pathological fractures or ligamentous disruptions and, on the other, identify any possible congenital anomalies that may also be mistaken for injury. Thus, in the present work, we discuss normal radiological features of the pediatric cervical spine, variants that may be encountered and pitfalls that must be avoided when interpreting plain radiographs taken in an emergency setting following trauma.

  17. The 'ABC' of examining foot radiographs.

    PubMed

    Pearse, Eyiyemi O; Klass, Benjamin; Bendall, Stephen P

    2005-11-01

    We report a simple systematic method of assessing foot radiographs that improves diagnostic accuracy and can reduce the incidence of inappropriate management of serious forefoot and midfoot injuries, particularly the Lisfranc-type injury. Five recently appointed senior house officers (SHOs), with no casualty or Orthopaedic experience prior to their appointment, were shown a set of 10 foot radiographs and told the history and examination findings recorded in the casualty notes of each patient within 6 weeks of taking up their posts. They were informed that the radiographs might or might not demonstrate an abnormality. They were asked to make a diagnosis and decide on a management plan. The test was repeated after they were taught the 'ABC' method of evaluating foot radiographs. Diagnostic accuracy improved after SHOs were taught a systematic method of assessing foot radiographs. The proportion of correct diagnoses increased from 0.64 to 0.78 and the probability of recognising Lisfranc injuries increased from 0 to 0.6. The use of this simple method of assessing foot radiographs can reduce the incidence of inappropriate management of serious foot injuries by casualty SHOs, in particular the Lisfranc type injury.

  18. Off-axis impact of unidirectional composites with cracks: Dynamic stress intensification

    NASA Technical Reports Server (NTRS)

    Sih, G. C.; Chen, E. P.

    1979-01-01

    The dynamic response of unidirectional composites under off axis (angle loading) impact is analyzed by assuming that the composite contains an initial flaw in the matrix material. The analytical method utilizes Fourier transform for the space variable and Laplace transform for the time variable. The off axis impact is separated into two parts, one being symmetric and the other skew-symmetric with reference to the crack plane. Transient boundary conditions of normal and shear tractions are applied to a crack embedded in the matrix of the unidirectional composite. The two boundary conditions are solved independently and the results superimposed. Mathematically, these conditions reduce the problem to a system of dual integral equations which are solved in the Laplace transform plane for the transformation of the dynamic stress intensity factor. The time inversion is carried out numerically for various combinations of the material properties of the composite and the results are displayed graphically.

  19. Low Frequency of Early Complications With Dual-mobility Acetabular Cups in Cementless Primary THA.

    PubMed

    Chughtai, Morad; Mistry, Jaydev B; Diedrich, Aloise M; Jauregui, Julio J; Elmallah, Randa K; Bonutti, Peter M; Harwin, Steven F; Malkani, Arthur L; Kolisek, Frank R; Mont, Michael A

    2016-10-01

    Dislocation complicates 1% to 5% of primary total hip arthroplasties (THAs). As a result, some surgeons consider dual-mobility articulations, which are usually used in the revision setting to decrease the likelihood of dislocation, as an option for primary THA. However, few studies have evaluated their use in this setting. (1) What is the cup survivorship when the dual-mobility articulation is used in the setting of primary THA? (2) What are the clinical outcomes with this approach? (3) What are the radiographic outcomes? (4) What are the complications of dual-mobility articulations in primary THA? Between 2011 and 2013, the five participating surgeons performed 495 cementless primary THAs. During that time, one of the five surgeons used dual-mobility articulations for all THAs, and the other four used it whenever the acetabular cup size was 52 mm or greater to enable a 28-mm head. Of the 495 patients, 453 (92%) were performed using this device. Smaller patients were treated with a standard THA. Of the 453 patients, a total of 43 patients (10%) were lost to followup before the 2-year minimum. The resulting 410 patients who were included in the analysis (164 men, 246 women) had a mean age of 64 years (SD, 12 years). The mean followup was 3 years (SD, 0.7 years). We performed Kaplan-Meier analyses to assess survivorship to aseptic failure and all-cause acetabular component survivorship. Clinical outcomes were evaluated using the Harris hip score (HHS); radiographs were assessed for cup migration, progressive radiolucencies, and positional changes of the components; and any surgery-related complications were recorded. The survivorship to aseptic failure and all-cause acetabular component survivorship was 99.8% (failures, n = 1) (95% confidence interval [CI], 4.517-4.547) and 99.3% (failures, aseptic, n = 1; septic, n = 2) (95% CI, 4.494-4.543); one hip had trunnion notching caused by impingement of a malpositioned cup, which was treated with revision of the cup and

  20. Intra-observer reproducibility and interobserver reliability of the radiographic parameters in the Spinal Deformity Study Group's AIS Radiographic Measurement Manual.

    PubMed

    Dang, Natasha Radhika; Moreau, Marc J; Hill, Douglas L; Mahood, James K; Raso, James

    2005-05-01

    Retrospective cross-sectional assessment of the reproducibility and reliability of radiographic parameters. To measure the intra-examiner and interexaminer reproducibility and reliability of salient radiographic features. The management and treatment of adolescent idiopathic scoliosis (AIS) depends on accurate and reproducible radiographic measurements of the deformity. Ten sets of radiographs were randomly selected from a sample of patients with AIS, with initial curves between 20 degrees and 45 degrees. Fourteen measures of the deformity were measured from posteroanterior and lateral radiographs by 2 examiners, and were repeated 5 times at intervals of 3-5 days. Intra-examiner and interexaminer differences were examined. The parameters include measures of curve size, spinal imbalance, sagittal kyphosis and alignment, maximum apical vertebral rotation, T1 tilt, spondylolysis/spondylolisthesis, and skeletal age. Intra-examiner reproducibility was generally excellent for parameters measured from the posteroanterior radiographs but only fair to good for parameters from the lateral radiographs, in which some landmarks were not clearly visible. Of the 13 parameters observed, 7 had excellent interobserver reliability. The measurements from the lateral radiograph were less reproducible and reliable and, thus, may not add value to the assessment of AIS. Taking additional measures encourages a systematic and comprehensive assessment of spinal radiographs.

  1. Radiographic parameters improve lower extremity prosthetic alignment.

    PubMed

    Mooney, Ryan; Carry, Patrick; Wylie, Erin; Schultz, Abby; McNair, Bryan; Page, Carol; Biffl, Susan; Heare, Travis

    2013-12-01

    The goal of prosthetic fitting is to provide comfort and functionality to the patient. It is thought that incorporating the use of standing anterior-posterior long leg radiographs (LLR) into the fitting of lower extremity prostheses will provide an objective guide when making adjustments, and be a better assessment of alignment. This study compares prosthetic alignment before and after radiography-guided adjustments. This retrospective study was performed at a multidisciplinary amputee clinic on patients with congenital and/or acquired limb deficiencies. Their prosthetic alignment was evaluated by LLR and adjusted as needed. Satisfactory alignment was defined as a mechanical axis angular deviation of ≤1° and a leg length discrepancy of ≤10 mm. A total of 45 unique prostheses from 24 subjects (10 female and 14 male) were included. Post-adjustment radiographs were obtained from 29 prostheses. After the initial prosthetic fitting, the probability of a satisfactory fit was 20.0 % (95 % CI 10.9-34.9 %). Following the baseline adjustment, the probability of a satisfactory fit improved to 53.3 % (95 % CI 37.5-70.9 %). After adjustment number 4, the probability of a satisfactory fit further improved to 76.7 % (95 % CI 41.9-98.0 %). There were also significant improvements in distal offset distance (p = 0.0040) and leg length discrepancy (p = 0.0206). The distal offset distance decreased by an average of 10.7 mm (95 % CI 3.6-17.8), and leg length discrepancy decreased by an average of 3.0 mm (95 % CI 00.48-5.5). The addition of LLRs to existing fitting methods significantly improves prosthetic alignment and length.

  2. Radiographic evaluation of the ankle syndesmosis.

    PubMed

    Croft, Stephen; Furey, Andrew; Stone, Craig; Moores, Carl; Wilson, Robert

    2015-02-01

    Radiographic measurements to document ankle anatomy have been suggested in recent literature to be inadequate. Focus has been put on stress views and computed tomography; however, there are also issues with these modalities. An orthogonal view that could be used both statically and dynamically could help determine syndesmotic stability. The purpose of this study was to determine a parameter on a normal lateral ankle radiograph that will increase the reliability of standard radiography in diagnosing syndesmotic integrity. Three orthopedic surgeons reviewed 80 lateral ankle radiographs. Thirty of those radiographs were reviewed on a second occasion. Rotation of the radiographs was determined by evaluating the overlap of the talar dome. Four radiographic parameters were measured 1 cm above the tibial plafond: fibular width, tibial width, and anterior and posterior tibiofibular intervals. Seventy-two radiographs were determined by consensus to be adequate. Means and ratios were documented to determine the relationship of the fibula to the tibia. Interrater reliability ranged from moderate to near-perfect, and the intrarater reliability was documented for each ratio. The anterior tibiofibular ratio was shown to be strong to near-perfect. It demonstrates that 40% of the tibia should be seen anterior to the fibula at 1cm above the tibial plafond. The anterior tibiofibular ratio provides an orthogonal measure for the syndesmosis that, in conjunction with those parameters previously documented, could clinically and economically improve the diagnosis of syndesmotic disruptions.

  3. 10 CFR 34.33 - Permanent radiographic installations.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 1 2013-01-01 2013-01-01 false Permanent radiographic installations. 34.33 Section 34.33 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Equipment § 34.33 Permanent radiographic installations. (a...

  4. 10 CFR 34.33 - Permanent radiographic installations.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Permanent radiographic installations. 34.33 Section 34.33 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Equipment § 34.33 Permanent radiographic installations. (a...

  5. 10 CFR 34.33 - Permanent radiographic installations.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 1 2012-01-01 2012-01-01 false Permanent radiographic installations. 34.33 Section 34.33 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Equipment § 34.33 Permanent radiographic installations. (a...

  6. 10 CFR 34.33 - Permanent radiographic installations.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 false Permanent radiographic installations. 34.33 Section 34.33 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Equipment § 34.33 Permanent radiographic installations. (a...

  7. 10 CFR 34.33 - Permanent radiographic installations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Permanent radiographic installations. 34.33 Section 34.33 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Equipment § 34.33 Permanent radiographic installations. (a...

  8. Methods employed for chest radiograph interpretation education for radiographers: A systematic review of the literature.

    PubMed

    McLaughlin, L; McConnell, J; McFadden, S; Bond, R; Hughes, C

    2017-11-01

    This systematic review aimed to determine the strength of evidence available in the literature on the effect of training to develop the skills required by radiographers to interpret plain radiography chest images. Thirteen articles feature within the review. Sample size varied from one reporting radiographer to 148 radiography students/experienced radiographers. The quality of the articles achieved a mean score of 7.5/10, indicating the evidence is strong and the quality of studies in this field is high. Investigative approaches included audit of participants' performance in clinical practice post formal training, evaluation of informal training and the impact of short feedback sessions on performance. All studies demonstrated positive attributions on user performance. Using a combination of training techniques can help maximise learning and accommodate those with different preferred learning types. Copyright © 2017 The College of Radiographers. Published by Elsevier Ltd. All rights reserved.

  9. [Clinical and radiographic correlation after anterior cruciate ligament reconstruction].

    PubMed

    González Perales, Aldo Alán; Negrete Corona, Jorge; Chávez Hinojosa, Edgard

    2010-01-01

    The purpose of this work is to correlate the clinical, functional and radiographic results of the anterior cruciate ligament (ACL) reconstruction with the angulation and orientation of the femoral and tibial tunnels. The ACL is one of the most frequently injured articular structures of the knee. The reason for this being that it is the primary limiting structure of anterior tibial translation; its tear causes kinematic alterations and results in long-term degenerative and functional changes. Repair can restore the kinematics. 26 patients, 20-50 years old, post-ACL reconstruction with the semitendinous-gracilis technique. From November 2006 to July 2007. Clinical and functional assessments: Tegner and Lysholm. Radiographic assessment: anteroposterior view with knee extension and lateral view with 30 degrees flexion. Pearson correlations (r) were used in the analysis. 26 patients (100%), 20 males (76.92%), 6 females (23.08%). Mean of 2.4 in the Lysholm scale (fair to good); standard deviation 1.2. Bernard-Lysholm quadrant r = -0.772. Tegner quadrant r = 0.790. The Lysholm and Tegner scale is associated with the graft quadrant. The situation of the tibial implant in the saggital plane is associated with the Lysholm scale. The correlation of patients with an inadequate placement with respect to the quadrants was associated with good-to-excellent results and fair-to-good results. Two patients had a poor clinical outcome; the orientation of the AP angle and the quadrant were within acceptable parameters, with the exception of the lateral angle-shaft axis.

  10. [Madrid study on the prevalence and characteristics of outpatients with dual pathology in community mental health and substance misuse services].

    PubMed

    Arias, Francisco; Szerman, Nestor; Vega, Pablo; Mesias, Beatriz; Basurte, Ignacio; Morant, Consuelo; Ochoa, Enriqueta; Poyo, Félix; Babín, Francisco

    2013-01-01

    The objective was to quantify the prevalence of dual diagnosis and to evaluate the characteristics of these patients from community mental health and substance misuse services in Madrid. The sample consisted of 837 outpatients from Madrid, 208 from mental health services and 629 from substance misuse services. We used the Mini International Neuropsychiatric Interview (MINI) and Personality Disorder Questionnaire (PDQ4+) to evaluate disorders from axis I and II. It was considered that 517 (61.8%) patients had dual pathology (current diagnoses of axis I or II disorders and an addictive disorder): 36,1% in mental health services and 70,3% in substance misuse services. There were fewer males amongst the dual patients and it was also found that they had a worse employment situation, along with higher figures of alcohol and cannabis dependence than addicts without dual diagnoses (n=194). When comparing them with patients with mental disorder diagnoses only, excluding substance use disorder (n=126), there were differences in all socio-demographic characteristics analyzed, and dual patients were associated with diagnoses of bipolar disorder, agoraphobia, generalized anxiety disorder, post-traumatic stress disorder, and had more suicide risk and different personality disorders. Thus, dual pathology is higher in patients who are in treatment and have differential characteristics (higher suicide risk, worse employment situation) that suggest greater severity that could be of help in the planning of care resource policies for these patients.

  11. Ergonomic strategies to improve radiographers' posture during mammography activities.

    PubMed

    Cernean, Nicolai; Serranheira, Florentino; Gonçalves, Pedro; Sá Dos Reis, Cláudia

    2017-08-01

    To identify alternatives for radiographers' postures while performing mammography that can contribute to reduce the risk of work-related musculoskeletal disorders (WRMSDs). Radiographers' postures to positioning craniocaudal (CC) and mediolateral oblique (MLO) views were simulated without any intervention for three scenarios: radiographer/patient with similar statures, radiographer smaller than patient and radiographer taller than patient. Actions were taken to modify the postures: seated radiographer; patient on a step; seated patient; radiographer on a step. All the postures were analysed using kinovea 0.8.15 software and the angles were measured twice and classified according to European standard EN1005-4: 2005. The non-acceptable angles were measured mainly during MLO positioning when radiographer was taller than the patient: 139° and 120° for arm-flexion and abduction, 72° for trunk and -24° for head/neck-flexion. The introduction of alternative postures (radiographer seated), allowed improvements in posture (60° and 99° for arm flexion and abduction, 14° for trunk and 0° for head/neck flexion), being classified as acceptable. The alternative postures simulated have the potential to reduce the risk of developing WRMSDs when radiographers and patients have different statures. • Radiographers' postures in mammography can contribute to work-related musculoskeletal disorders • Non-acceptable posture was identified for MLO breast positioning (radiographer taller than patient) • Adapting posture to patient biotype reduces the WRMSD risk for radiographers.

  12. Full ocular biometry through dual-depth whole-eye optical coherence tomography

    PubMed Central

    Kim, Hyung-Jin; Kim, Minji; Hyeon, Min Gyu; Choi, Youngwoon; Kim, Beop-Min

    2018-01-01

    We propose a new method of determining the optical axis (OA), pupillary axis (PA), and visual axis (VA) of the human eye by using dual-depth whole-eye optical coherence tomography (OCT). These axes, as well as the angles “α” between the OA and VA and “κ” between PA and VA, are important in many ophthalmologic applications, especially in refractive surgery. Whole-eye images are reconstructed based on simultaneously acquired images of the anterior segment and retina. The light from a light source is split into two orthogonal polarization components for imaging the anterior segment and retina, respectively. The OA and PA are identified based on their geometric definitions by using the anterior segment image only, while the VA is detected through accurate correlation between the two images. The feasibility of our approach was tested using a model eye and human subjects. PMID:29552378

  13. 21 CFR 892.1850 - Radiographic film cassette.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Radiographic film cassette. 892.1850 Section 892...) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1850 Radiographic film cassette. (a) Identification. A radiographic film cassette is a device intended for use during diagnostic x-ray procedures to...

  14. 21 CFR 892.1890 - Radiographic film illuminator.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Radiographic film illuminator. 892.1890 Section... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1890 Radiographic film illuminator. (a) Identification. A radiographic film illuminator is a device containing a visible light source covered with a...

  15. 21 CFR 892.1850 - Radiographic film cassette.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Radiographic film cassette. 892.1850 Section 892...) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1850 Radiographic film cassette. (a) Identification. A radiographic film cassette is a device intended for use during diagnostic x-ray procedures to...

  16. 21 CFR 892.1890 - Radiographic film illuminator.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Radiographic film illuminator. 892.1890 Section... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1890 Radiographic film illuminator. (a) Identification. A radiographic film illuminator is a device containing a visible light source covered with a...

  17. 21 CFR 892.1890 - Radiographic film illuminator.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Radiographic film illuminator. 892.1890 Section... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1890 Radiographic film illuminator. (a) Identification. A radiographic film illuminator is a device containing a visible light source covered with a...

  18. 21 CFR 892.1850 - Radiographic film cassette.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Radiographic film cassette. 892.1850 Section 892...) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1850 Radiographic film cassette. (a) Identification. A radiographic film cassette is a device intended for use during diagnostic x-ray procedures to...

  19. 21 CFR 892.1890 - Radiographic film illuminator.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Radiographic film illuminator. 892.1890 Section... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1890 Radiographic film illuminator. (a) Identification. A radiographic film illuminator is a device containing a visible light source covered with a...

  20. 21 CFR 892.1890 - Radiographic film illuminator.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radiographic film illuminator. 892.1890 Section... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1890 Radiographic film illuminator. (a) Identification. A radiographic film illuminator is a device containing a visible light source covered with a...

  1. 21 CFR 892.1850 - Radiographic film cassette.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radiographic film cassette. 892.1850 Section 892...) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1850 Radiographic film cassette. (a) Identification. A radiographic film cassette is a device intended for use during diagnostic x-ray procedures to...

  2. Nonlinear dual-axis biodynamic response of the semi-supine human body during vertical whole-body vibration

    NASA Astrophysics Data System (ADS)

    Huang, Ya; Griffin, Michael J.

    2008-04-01

    Nonlinear biodynamic responses are evident in many studies of the apparent masses of sitting and standing subjects in static postures that require muscle activity for postural control. In the present study, 12 male subjects adopted a relaxed semi-supine posture assumed to involve less muscle activity than during static sitting and standing. The supine subjects were exposed to two types of vertical vibration (in the x-axis of the semi-supine body): (i) continuous random vibration (0.25-20 Hz) at five magnitudes (0.125, 0.25, 0.5, 0.75, and 1.0 m s -2 rms); (ii) intermittent random vibration (0.25-20 Hz) alternately at 0.25 and 1.0 m s -2 rms. With continuous random vibration, the dominant primary resonance frequency in the median normalised apparent mass decreased from 10.35 to 7.32 Hz as the vibration magnitude increased from 0.125 to 1.0 m s -2 rms. This nonlinear response was apparent in both the vertical ( x-axis) apparent mass and in the horizontal ( z-axis) cross-axis apparent mass. As the vibration magnitude increased from 0.25 to 1.0 m s -2 rms, the median resonance frequency of the apparent mass with intermittent random vibration decreased from 9.28 to 8.06 Hz whereas, over the same range of magnitudes with continuous random vibration, the resonance frequency decreased from 9.62 to 7.81 Hz. The median change in the resonance frequency (between 0.25 and 1.0 m s -2 rms) was 1.37 Hz with the intermittent random vibration and 1.71 with the continuous random vibration. With the intermittent vibration, the resonance frequency was higher at the high magnitude and lower at the low magnitude than with continuous vibration of the same magnitudes. The response was typical of thixotropy that may be a primary cause of the nonlinear biodynamic responses to whole-body vibration.

  3. Dual-Telescope Multi-Channel Thermal-Infrared Radiometer for Outer Planet Fly-By Missions

    NASA Technical Reports Server (NTRS)

    Aslam, Shahid; Amato, Michael; Bowles, Neil; Calcutt, Simon; Hewagama, Tilak; Howard, Joseph; Howett, Carly; Hsieh, Wen-Ting; Hurford, Terry; Hurley, Jane; hide

    2016-01-01

    The design of a versatile dual-telescope thermal-infrared radiometer spanning the spectral wavelength range 8-200 microns, in five spectral pass bands, for outer planet fly-by missions is described. The dual- telescope design switches between a narrow-field-of-view and a wide-field-of-view to provide optimal spatial resolution images within a range of spacecraft encounters to the target. The switchable dual-field- of-view system uses an optical configuration based on the axial rotation of a source-select mirror along the optical axis. The optical design, spectral performance, radiometric accuracy, and retrieval estimates of the instrument are discussed. This is followed by an assessment of the surface coverage performance at various spatial resolutions by using the planned NASA Europa Mission 13-F7 fly-by trajectories as a case study.

  4. Development and validation of a quantitative method to assess pedicle screw loosening in posterior spine instrumentation on plain radiographs.

    PubMed

    Aghayev, Emin; Zullig, Nicolas; Diel, Peter; Dietrich, Daniel; Benneker, Lorin M

    2014-03-01

    Currently, the diagnosis of pedicle screw (PS) loosening is based on a subjectively assessed halo sign, that is, a radiolucent line around the implant wider than 1 mm in plain radiographs. We aimed at development and validation of a quantitative method to diagnose PS loosening on radiographs. Between 11/2004 and 1/2010 36 consecutive patients treated with thoraco-lumbar spine fusion with PS instrumentation without PS loosening were compared with 37 other patients who developed a clinically manifesting PS loosening. Three different angles were measured and compared regarding their capability to discriminate the loosened PS over the postoperative course. The inter-observer invariance was tested and a receiver operating characteristics curve analysis was performed. The angle measured between the PS axis and the cranial endplate was significantly different between the early and all later postoperative images. The Spearman correlation coefficient for the measurements of two observers at each postoperative time point ranged between 0.89 at 2 weeks to 0.94 at 2 months and 1 year postoperative. The angle change of 1.9° between immediate postoperative and 6-month postoperative was 75% sensitive and 89% specific for the identification of loosened screws (AUC = 0.82). The angle between the PS axis and the cranial endplate showed good ability to change in PS loosening. A change of this angle of at least 2° had a relatively high sensitivity and specificity to diagnose screw loosening.

  5. Endocrine changes in histiocytosis of the hypothalamic-pituitary axis.

    PubMed

    Toro Galván, Silvia; Planas Vilaseca, Alejandra; Michalopoulou Alevras, Theodora; Torres Díaz, Alberto; Suárez Balaguer, Javier; Villabona Artero, Carles

    2015-02-01

    Histiocytosis is characterized by proliferation of cells from the mononuclear phagocyte system, and may be divided into Langerhans cell histiocytosis (LCH) and non-Langerhans cell histiocytosis (including Erdheim-Chester disease [ECD]). While diabetes insipidus (DI) is the most common hypothalamic-pituitary consequence, anterior pituitary deficiencies are less known. This study analyzed the frequency and progression of pituitary hormone deficiencies and the radiographic findings in 9 patients (7 with LCH and 2 with ECD) with hypothalamic-pituitary (HP) axis. Eighty-nine percent of patients had DI (62% at diagnosis), and 78% had one or more anterior pituitary deficiencies (71% at diagnosis). HP involvement is relatively common in patients diagnosed with histiocytosis and hormone deficiencies may be present at diagnosis or appear gradually during the course of disease. Regular monitoring of these patients is recommended. Copyright © 2014 SEEN. Published by Elsevier España, S.L.U. All rights reserved.

  6. A CT scan protocol for the detection of radiographic loosening of the glenoid component after total shoulder arthroplasty

    PubMed Central

    2014-01-01

    Background and purpose It is difficult to evaluate glenoid component periprosthetic radiolucencies in total shoulder arthroplasties (TSAs) using plain radiographs. This study was performed to evaluate whether computed tomography (CT) using a specific patient position in the CT scanner provides a better method for assessing radiolucencies in TSA. Methods Following TSA, 11 patients were CT scanned in a lateral decubitus position with maximum forward flexion, which aligns the glenoid orientation with the axis of the CT scanner. Follow-up CT scanning is part of our routine patient care. Glenoid component periprosthetic lucency was assessed according to the Molé score and it was compared to routine plain radiographs by 5 observers. Results The protocol almost completely eliminated metal artifacts in the CT images and allowed accurate assessment of periprosthetic lucency of the glenoid fixation. Positioning of the patient within the CT scanner as described was possible for all 11 patients. A radiolucent line was identified in 54 of the 55 observed CT scans and osteolysis was identified in 25 observations. The average radiolucent line Molé score was 3.4 (SD 2.7) points with plain radiographs and 9.5 (SD 0.8) points with CT scans (p = 0.001). The mean intra-observer variance was lower in the CT scan group than in the plain radiograph group (p = 0.001). Interpretation The CT scan protocol we used is of clinical value in routine assessment of glenoid periprosthetic lucency after TSA. The technique improves the ability to detect and monitor radiolucent lines and, therefore, possibly implant loosening also. PMID:24286563

  7. Effectiveness of a Radiographic Anatomy Software Application for Enhancing Learning of Veterinary Radiographic Anatomy.

    PubMed

    Reiter, Rachel; Viehdorfer, Matt; Hescock, Kimmy; Clark, Terri; Nemanic, Sarah

    The goal of this study was to determine the effectiveness of an interactive radiology software application that we developed to enhance learning of normal canine radiographic anatomy. All first-year veterinary medical students were eligible to participate in this subject pre-test-post-test experimental design. When presented with the software application, all students had completed two terms of gross anatomy in which the complete anatomy of the dog had been taught using a combination of lectures and laboratory dissections, including radiographic examples. The software application was divided into four body regions: front limb, hind limb, skull/spine, and thorax/abdomen, each with a learning mode and a quiz mode. Quizzes were composed of 15 questions drawn pseudo-randomly without repeat from all structures within a region (median 206 structures). Students were initially given the software application with only the quiz mode activated. After completing four quizzes, one for each body region, students were given access to the software application with both learning mode and quiz mode activated. Students were instructed to spend 30 minutes using the learning mode to study the radiographic anatomy of each region and to retake each quiz. Quiz scores after using the learning mode were significantly higher for each body region (p<.001), with a large effect size for all four regions (Cohen's d=0.83-1.56). These results suggest that this radiographic anatomy software application is an effective tool for students to use to learn normal radiographic anatomy.

  8. A dual cone-beam CT system for image guided radiotherapy: initial performance characterization.

    PubMed

    Li, Hao; Giles, William; Bowsher, James; Yin, Fang-Fang

    2013-02-01

    The purpose of this study is to evaluate the performance of a recently developed benchtop dual cone-beam computed tomography (CBCT) system with two orthogonally placed tube∕detector sets. The benchtop dual CBCT system consists of two orthogonally placed 40 × 30 cm flat-panel detectors and two conventional x-ray tubes with two individual high-voltage generators sharing the same rotational axis. The x-ray source to detector distance is 150 cm and x-ray source to rotational axis distance is 100 cm for both subsystems. The objects are scanned through 200° of rotation. The dual CBCT system utilized 110° of projection data from one detector and 90° from the other while the two individual single CBCTs utilized 200° data from each detector. The system performance was characterized in terms of uniformity, contrast, spatial resolution, noise power spectrum, and CT number linearity. The uniformities, within the axial slice and along the longitudinal direction, and noise power spectrum were assessed by scanning a water bucket; the contrast and CT number linearity were measured using the Catphan phantom; and the spatial resolution was evaluated using a tungsten wire phantom. A skull phantom and a ham were also scanned to provide qualitative evaluation of high- and low-contrast resolution. Each measurement was compared between dual and single CBCT systems. Compared to single CBCT, the dual CBCT presented: (1) a decrease in uniformity by 1.9% in axial view and 1.1% in the longitudinal view, as averaged for four energies (80, 100, 125, and 150 kVp); (2) comparable or slightly better contrast (0∼25 HU) for low-contrast objects and comparable contrast for high-contrast objects; (3) comparable spatial resolution; (4) comparable CT number linearity with R(2) ≥ 0.99 for all four tested energies; (5) lower noise power spectrum in magnitude. Dual CBCT images of the skull phantom and the ham demonstrated both high-contrast resolution and good soft-tissue contrast. The

  9. Dual-energy computed tomographic virtual noncalcium algorithm for detection of bone marrow edema in acute fractures: early experiences.

    PubMed

    Reagan, Adrian C; Mallinson, Paul I; O'Connell, Timothy; McLaughlin, Patrick D; Krauss, Bernhard; Munk, Peter L; Nicolaou, Savvas; Ouellette, Hugue A

    2014-01-01

    Computed tomography (CT) is often used to assess the presence of occult fractures when plain radiographs are equivocal in the acute traumatic setting. While providing increased spatial resolution, conventional computed tomography is limited in the assessment of bone marrow edema, a finding that is readily detectable on magnetic resonance imaging (MRI).Dual-energy CT has recently been shown to demonstrate patterns of bone marrow edema similar to corresponding MRI studies. Dual-energy CT may therefore provide a convenient modality for further characterizing acute bony injury when MRI is not readily available. We report our initial experiences of 4 cases with imaging and clinical correlation.

  10. Radiographical measurements for distal intra-articular fractures of the radius using plain radiographs and cone beam computed tomography images.

    PubMed

    Suojärvi, Nora; Sillat, T; Lindfors, N; Koskinen, S K

    2015-12-01

    Operative treatment of an intra-articular distal radius fracture is one of the most common procedures in orthopedic and hand surgery. The intra- and interobserver agreement of common radiographical measurements of these fractures using cone beam computed tomography (CBCT) and plain radiographs were evaluated. Thirty-seven patients undergoing open reduction and volar fixation for a distal radius fracture were studied. Two radiologists analyzed the preoperative radiographs and CBCT images. Agreement of the measurements was subjected to intra-class correlation coefficient and the Bland-Altman analyses. Plain radiographs provided a slightly poorer level of agreement. For fracture diastasis, excellent intraobserver agreement was achieved for radiographs and good or excellent agreement for CBCT, compared to poor interobserver agreement (ICC 0.334) for radiographs and good interobserver agreement (ICC 0.621) for CBCT images. The Bland-Altman analyses indicated a small mean difference between the measurements but rather large variation using both imaging methods, especially in angular measurements. For most of the measurements, radiographs do well, and may be used in clinical practice. Two different measurements by the same reader or by two different readers can lead to different decisions, and therefore a standardization of the measurements is imperative. More detailed analysis of articular surface needs cross-sectional imaging modalities.

  11. Digital interactive learning of oral radiographic anatomy.

    PubMed

    Vuchkova, J; Maybury, T; Farah, C S

    2012-02-01

    Studies reporting high number of diagnostic errors made from radiographs suggest the need to improve the learning of radiographic interpretation in the dental curriculum. Given studies that show student preference for computer-assisted or digital technologies, the purpose of this study was to develop an interactive digital tool and to determine whether it was more successful than a conventional radiology textbook in assisting dental students with the learning of radiographic anatomy. Eighty-eight dental students underwent a learning phase of radiographic anatomy using an interactive digital tool alongside a conventional radiology textbook. The success of the digital tool, when compared to the textbook, was assessed by quantitative means using a radiographic interpretation test and by qualitative means using a structured Likert scale survey, asking students to evaluate their own learning outcomes from the digital tool. Student evaluations of the digital tool showed that almost all participants (95%) indicated that the tool positively enhanced their learning of radiographic anatomy and interpretation. The success of the digital tool in assisting the learning of radiographic interpretation is discussed in the broader context of learning and teaching curricula, and preference (by students) for the use of this digital form when compared to the conventional literate form of the textbook. Whilst traditional textbooks are still valued in the dental curriculum, it is evident that the preference for computer-assisted learning of oral radiographic anatomy enhances the learning experience by enabling students to interact and better engage with the course material. © 2011 John Wiley & Sons A/S.

  12. Bone and cartilage characteristics in postmenopausal women with mild knee radiographic osteoarthritis and those without radiographic osteoarthritis

    PubMed Central

    Multanen, J.; Heinonen, A.; Häkkinen, A.; Kautiainen, H.; Kujala, U.M.; Lammentausta, E.; Jämsä, T.; Kiviranta, I.; Nieminen, M.T.

    2015-01-01

    Objectives: To evaluate the association between radiographically-assessed knee osteoarthritis and femoral neck bone characteristics in women with mild knee radiographic osteoarthritis and those without radiographic osteoarthritis. Methods: Ninety postmenopausal women (mean age [SD], 58 [4] years; height, 163 [6] cm; weight, 71 [11] kg) participated in this cross-sectional study. The severity of radiographic knee osteoarthritis was defined using Kellgren-Lawrence grades 0=normal (n=12), 1=doubtful (n=25) or 2=minimal (n=53). Femoral neck bone mineral content (BMC), section modulus (Z), and cross-sectional area (CSA) were measured with DXA. The biochemical composition of ipsilateral knee cartilage was estimated using quantitative MRI measures, T2 mapping and dGEMRIC. The associations between radiographic knee osteoarthritis grades and bone and cartilage characteristics were analyzed using generalized linear models. Results: Age-, height-, and weight-adjusted femoral neck BMC (p for linearity=0.019), Z (p for linearity=0.033), and CSA (p for linearity=0.019) increased significantly with higher knee osteoarthritis grades. There was no linear relationship between osteoarthritis grades and knee cartilage indices. Conclusions: Increased DXA assessed hip bone strength is related to knee osteoarthritis severity. These results are hypothesis driven that there is an inverse relationship between osteoarthritis and osteoporosis. However, MRI assessed measures of cartilage do not discriminate mild radiographic osteoarthritis severity. PMID:25730654

  13. Dual Mobility Cemented Cups Have Low Dislocation Rates in THA Revisions

    PubMed Central

    Langlais, Frantz L.; Gaucher, François; Musset, Thierry; Chaix, Olivier

    2008-01-01

    THA revisions using standard cups are at risk of dislocation (5.1% to 14.4% incidence), especially in patients over 70 years of age. Constrained tripolar cups have reduced this risk (6% incidence) but are associated with substantial loosening rates (9%). The nonconstrained dual mobility cup was designed to improve prosthetic stability (polyethylene head ≥ 40 mm diameter) without increasing loosening rates by reducing wear and limiting impingement (rotation range of 108°). We implanted 88 cemented dual mobility cups for THA revisions in 82 patients at high risk of dislocation. Average patient age was 72 years (range, 65–86 years). Eighty-five of the 88 hips were reviewed at 2 to 5 years followup. One patient (1.1%) had a traumatic dislocation at 2 years postoperatively. Two patients (2.3%) had asymptomatic early loosening and three patients (3.5%) had localized radiographic lucencies. These results confirm those with press-fit dual mobility cups suggesting a low dislocation rate at 5 years and a cup survival of 94.6%. At middle term followup, cemented dual mobility cup achieved better results than constrained cups in cases at risk of dislocation and recurrent loosening. Level of Evidence: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence. PMID:18196422

  14. DARHT Axis II Cathode 16 (S/N 22) History as Recorded in the Historian and Shot Data Databases

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Smith, H. Vernon; Barraza, Juan; Harrison, James F.

    2014-01-10

    Long DARHT II injector cathode operating lifetimes are desirable for flash radiography of hydrodynamic tests at the dual-axis radiographic hydrotest facility (DARHT). The specification for cathode operating lifetime given to Spectra-Mat in the purchase orders for the 311X-M cathodes is ≥ 1000 hours at full operating temperature (~1120 oC). Of the five most-recent cathodes operated on DARHT II, only two have met this specification. It is desirable to have cathodes lifetimes considerably longer than the specified 1000 hours. In this report we present the thermal and vacuum history of cathode 16 (serial no. [S/N] 22), a 311X-M cathode, as recordedmore » in the historian database and the shot data database. The hope is that by examining this history we can identify the parameter (or parameters) that are limiting the DARHT II 311X-M cathode lifetimes. This is the fifth in a series of 5 DARHT Tech Notes in which recent cathode thermal and vacuum histories are examined. The other tech notes in this series are DARHT Tech Notes Nos. 501 (cathode 12, S/N 15), 502 (cathode 13, S/N 19), 503 (cathode 14, S/N 20), and 504 (cathode 15, S/N 21). In DARHT Tech Note No. 506 we will compare the recorded thermal and vacuum histories of cathodes 12-16 and attempt to understand the cathode lifetime limitations based on the stored cathode data presented in DARHT Tech Notes 501-505 and other relevant information.« less

  15. Radiographic anatomy of juvenile bovine limbs.

    PubMed

    Hoey, S E; Biedrzycki, A H; Livesey, M J; Drees, R

    2016-11-26

    Juvenile bovine patients who present with clinical signs of lameness are commonly evaluated using radiographic techniques both within a hospital setting and in a farm environment. The radiographic development of the juvenile bovine skeleton is currently poorly documented. In this study, the limbs of four heifer calves were sequentially radiographed to assess development of the juvenile bovine appendicular skeleton in the first 12 months of life. Images were acquired at three weeks, three months, six months, nine months and one year of age. The normal radiographic anatomy of the fore limbs and hindlimbs and the changes over the first 12 months are described. The majority of physes remain open throughout this period, with the exception of the proximal physes of the proximal and middle phalanges, the proximal radial physis, and the proximal humeral physis which close radiographically between 9 months and 12 months of age, and fusion of the fourth and central tarsal bones occurs between 9 months and 12 months of age. The results of this study may aid in differentiating normal and abnormal anatomy in the juvenile bovine limb. British Veterinary Association.

  16. Relevance of 2D radiographic texture analysis for the assessment of 3D bone micro-architecture

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Apostol, Lian; Boudousq, Vincent; Basset, Oliver

    Although the diagnosis of osteoporosis is mainly based on dual x-ray absorptiometry, it has been shown that trabecular bone micro-architecture is also an important factor in regard to fracture risk. In vivo, techniques based on high-resolution x-ray radiography associated to texture analysis have been proposed to investigate bone micro-architecture, but their relevance for giving pertinent 3D information is unclear. Thirty-three calcaneus and femoral neck bone samples including the cortical shells (diameter: 14 mm, height: 30-40 mm) were imaged using 3D-synchrotron x-ray micro-CT at the ESRF. The 3D reconstructed images with a cubic voxel size of 15 {mu}m were further usedmore » for two purposes: (1) quantification of three-dimensional trabecular bone micro-architecture (2) simulation of realistic x-ray radiographs under different acquisition conditions. The simulated x-ray radiographs were then analyzed using a large variety of texture analysis methods (co-occurrence, spectral density, fractal, morphology, etc.). The range of micro-architecture parameters was in agreement with previous studies and rather large, suggesting that the population was representative. More than 350 texture parameters were tested. A small number of them were selected based on their correlation to micro-architectural morphometric parameters. Using this subset of texture parameters, multiple regression allowed one to predict up to 93% of the variance of micro-architecture parameters using three texture features. 2D texture features predicting 3D micro-architecture parameters other than BV/TV were identified. The methodology proposed for evaluating the relationships between 3D micro-architecture and 2D texture parameters may also be used for optimizing the conditions for radiographic imaging. Further work will include the application of the method to physical radiographs. In the future, this approach could be used in combination with DXA to refine osteoporosis diagnosis.« less

  17. Spatial phase-shift dual-beam speckle interferometry.

    PubMed

    Gao, Xinya; Yang, Lianxiang; Wang, Yonghong; Zhang, Boyang; Dan, Xizuo; Li, Junrui; Wu, Sijin

    2018-01-20

    The spatial phase-shift technique has been successfully applied to an out-of-plane speckle interferometry system. Its application to a pure in-plane sensitive system has not been reported yet. This paper presents a novel optical configuration that enables the application of the spatial phase-shift technique to pure in-plane sensitive dual-beam speckle interferometry. The new spatial phase-shift dual-beam speckle interferometry (SPS-DBSP) uses a dual-beam in-plane electronic speckle pattern interferometry configuration with individual aperture shears, avoiding the interference in the object plane by the use of a low-coherence source, and different optical paths. The measured object is illuminated by two incoherent beams that are generated by a delay line, which is larger than the coherence length of the laser. The two beams reflected from the object surface interfere with each other at the CCD plane because of different optical paths. A spatial phase shift is introduced by the angle between the two apertures when they are mapped to the same optical axis. The phase of the in-plane deformation can directly be extracted from the speckle patterns by the Fourier transform method. The capability of SPS-DBSI is demonstrated by theoretical discussion as well as experiments.

  18. Beam-energy-spread minimization using cell-timing optimization

    NASA Astrophysics Data System (ADS)

    Rose, C. R.; Ekdahl, C.; Schulze, M.

    2012-04-01

    Beam energy spread, and related beam motion, increase the difficulty in tuning for multipulse radiographic experiments at the dual-axis radiographic hydrodynamic test facility’s axis-II linear induction accelerator (LIA). In this article, we describe an optimization method to reduce the energy spread by adjusting the timing of the cell voltages (both unloaded and loaded), either advancing or retarding, such that the injector voltage and summed cell voltages in the LIA result in a flatter energy profile. We developed a nonlinear optimization routine which accepts as inputs the 74 cell-voltage, injector voltage, and beam current waveforms. It optimizes cell timing per user-selected groups of cells and outputs timing adjustments, one for each of the selected groups. To verify the theory, we acquired and present data for both unloaded and loaded cell-timing optimizations. For the unloaded cells, the preoptimization baseline energy spread was reduced by 34% and 31% for two shots as compared to baseline. For the loaded-cell case, the measured energy spread was reduced by 49% compared to baseline.

  19. Dual-telescope multi-channel thermal-infrared radiometer for outer planet fly-by missions

    NASA Astrophysics Data System (ADS)

    Aslam, Shahid; Amato, Michael; Bowles, Neil; Calcutt, Simon; Hewagama, Tilak; Howard, Joseph; Howett, Carly; Hsieh, Wen-Ting; Hurford, Terry; Hurley, Jane; Irwin, Patrick; Jennings, Donald E.; Kessler, Ernst; Lakew, Brook; Loeffler, Mark; Mellon, Michael; Nicoletti, Anthony; Nixon, Conor A.; Putzig, Nathaniel; Quilligan, Gerard; Rathbun, Julie; Segura, Marcia; Spencer, John; Spitale, Joseph; West, Garrett

    2016-11-01

    The design of a versatile dual-telescope thermal-infrared radiometer spanning the spectral wavelength range 8-200 μm, in five spectral pass bands, for outer planet fly-by missions is described. The dual-telescope design switches between a narrow-field-of-view and a wide-field-of-view to provide optimal spatial resolution images within a range of spacecraft encounters to the target. The switchable dual-field-of-view system uses an optical configuration based on the axial rotation of a source-select mirror along the optical axis. The optical design, spectral performance, radiometric accuracy, and retrieval estimates of the instrument are discussed. This is followed by an assessment of the surface coverage performance at various spatial resolutions by using the planned NASA Europa Mission 13-F7 fly-by trajectories as a case study.

  20. Influence of radiographic techniques on the measurement of femoral anteversion angles and a conformation score of pelvic limbs in Labrador retrievers.

    PubMed

    Mostafa, Ayman A; Cunningham, Devin P; Boudrieau, Randy J; Kowaleski, Michael P; Griffon, Dominique J

    2018-04-01

    To determine repeatability of and correlation between 2 radiographic measurements of femoral anteversion angles (FAA) and to determine their influence on a score derived from tibial plateau angle (TPA) and FAA to predict the risk of cranial cruciate ligament disease (CCLD). Prospective clinical study. Forty-eight Labrador retrievers with or without CCLD. FAA and CCLD scores were calculated for each limb from extended pelvic radiographs (t-FAA) or angled (a-FAA) projections of the femur by 3 investigators. One investigator repeated measurements twice. Data were analyzed for repeatability, correlation between t-FAA and a-FAA, and their influence on CCLD scores. FAA correlated most strongly with the distance between the femoral head and the femoral axis on mediolateral radiographs, a measurement with excellent repeatability. t-FAA and a-FAA correlated with each other (r > 0.79, P < .0001), although t-FAA were about 1° greater than a-FAA (P = .01). Intrainvestigator and interinvestigator repeatability of the CCLD score was fair when derived from t-FAA and good to excellent when derived from a-FAA. CCLD scores differed between radiographic techniques but led to different predictions in only 9 (10%) limbs, all with lower TPA and CCLD scores than the rest of the population. a-FAA correlated strongly with t-FAA and improved the repeatability of CCLD scores within and between investigators. A craniocaudal angled beam projection of the femur is a suitable alternative to a ventrodorsal pelvic radiograph when measuring FAA and may improve the repeatability and positive predictive value of CCLD scores. © 2018 The American College of Veterinary Surgeons.

  1. Lead Scales for X-Radiographs

    NASA Technical Reports Server (NTRS)

    Burley, Richard K.; Adams, James F.

    1987-01-01

    Indentations made by typing on lead tape. Lead scales for inclusion in x-radiographs as length and position references created by repeatedly imprinting character like upper-case I, L, or V, or lower-case L into lead tape with typewriter. Character pitch of typewriter serves as length reference for scale. Thinning of tape caused by impacts of type shows up dark in radiograph.

  2. Radiographic findings of femoroacetabular impingement in National Football League Combine athletes undergoing radiographs for previous hip or groin pain.

    PubMed

    Nepple, Jeffrey J; Brophy, Robert H; Matava, Matthew J; Wright, Rick W; Clohisy, John C

    2012-10-01

    The purpose of this study was to investigate the prevalence of radiographic findings of femoroacetabular impingement (FAI) in elite football players with a history of hip pain or groin injury who underwent radiographs. We performed a retrospective review of athletes undergoing hip radiography at the National Football League Combine from 2007 to 2009. Radiographs were obtained in athletes with a history of hip pain or injury. Anteroposterior pelvis and frog-lateral radiographs were obtained in 123 hips (107 players) that met our inclusion criteria. Radiographic indicators of cam-type FAI (alpha angle, head-neck offset ratio) and pincer-type FAI (acetabular retroversion, center-edge angle, acetabular inclination) were recorded. Findings were correlated with clinical factors (previous groin/hip pain, position, race, and body mass index). The most common previous injuries included groin strain (n = 57) and sports hernia/abdominal strain (n = 21). Markers of cam- and/or pincer-type FAI were present in 94.3% of hips (116 of 123). Radiographic evidence of combined cam- and pincer-type FAI was the most common (61.8%, 76 hips), whereas isolated cam-type FAI (9.8%, 12 hips) and pincer-type FAI (22.8%, 28 hips) were less common. The most common deformities included acetabular retroversion (71.5%) and an abnormal alpha angle (61.8%). A body mass index greater than 35 was associated with the presence of global overcoverage (46.2% v 17.3%, P = .025). Radiographic indicators of FAI are very common among athletes evaluated at the National Football League Scouting Combine subjected to radiographic examination for the clinical suspicion of hip disease. Elite football athletes with significant or recurrent pain about the hip should be evaluated clinically and radiographically for FAI, because pain from FAI may be falsely attributed to or may be present in addition to other disorders. Level IV, therapeutic case series. Copyright © 2012 Arthroscopy Association of North America

  3. Bone texture analysis on dental radiographic images: results with several angulated radiographs on the same region of interest

    NASA Astrophysics Data System (ADS)

    Amouriq, Yves; Guedon, Jeanpierre; Normand, Nicolas; Arlicot, Aurore; Benhdech, Yassine; Weiss, Pierre

    2011-03-01

    Bone microarchitecture is the predictor of bone quality or bone disease. It can only be measured on a bone biopsy, which is invasive and not available for all clinical situations. Texture analysis on radiographs is a common way to investigate bone microarchitecture. But relationship between three-dimension histomorphometric parameters and two-dimension texture parameters is not always well known, with poor results. The aim of this study is to performed angulated radiographs of the same region of interest and see if a better relationship between texture analysis on several radiographs and histomorphometric parameters can be developed. Computed radiography images of dog (Beagle) mandible section in molar regions were compared with high-resolution micro-CT (Computed-Tomograph) volumes. Four radiographs with 27° angle (up, down, left, right, using Rinn ring and customized arm positioning system) were performed from initial radiograph position. Bone texture parameters were calculated on all images. Texture parameters were also computed from new images obtained by difference between angulated images. Results of fractal values in different trabecular areas give some caracterisation of bone microarchitecture.

  4. 21 CFR 892.1900 - Automatic radiographic film processor.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Automatic radiographic film processor. 892.1900... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1900 Automatic radiographic film processor. (a) Identification. An automatic radiographic film processor is a device intended to be used to...

  5. 21 CFR 892.1900 - Automatic radiographic film processor.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Automatic radiographic film processor. 892.1900... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1900 Automatic radiographic film processor. (a) Identification. An automatic radiographic film processor is a device intended to be used to...

  6. 21 CFR 892.1900 - Automatic radiographic film processor.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Automatic radiographic film processor. 892.1900... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1900 Automatic radiographic film processor. (a) Identification. An automatic radiographic film processor is a device intended to be used to...

  7. 21 CFR 892.1900 - Automatic radiographic film processor.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Automatic radiographic film processor. 892.1900... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1900 Automatic radiographic film processor. (a) Identification. An automatic radiographic film processor is a device intended to be used to...

  8. 21 CFR 892.1900 - Automatic radiographic film processor.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Automatic radiographic film processor. 892.1900... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1900 Automatic radiographic film processor. (a) Identification. An automatic radiographic film processor is a device intended to be used to...

  9. Reliability of a new method for measuring coronal trunk imbalance, the axis-line-angle technique.

    PubMed

    Zhang, Rui-Fang; Liu, Kun; Wang, Xue; Liu, Qian; He, Jia-Wei; Wang, Xiang-Yang; Yan, Zhi-Han

    2015-12-01

    Accurate determination of the extent of trunk imbalance in the coronal plane plays a key role in an evaluation of patients with trunk imbalance, such as patients with adolescent idiopathic scoliosis. An established, widely used practice in evaluating trunk imbalance is to drop a plumb line from the C7 vertebra to a key reference axis, the central sacral vertical line (CSVL) in full-spine standing anterioposterior radiographs, and measuring the distance between them, the C7-CSVL. However, measuring the CSVL is subject to intraobserver differences, is error-prone, and is of poor reliability. Therefore, the development of a different way to measure trunk imbalance is needed. This study aimed to describe a new method to measure coronal trunk imbalance, the axis-line-angle technique (ALAT), which measures the angle at the intersection between the C7 plumb line and an axis line drawn from the vertebral centroid of the C7 to the middle of the superior border of the symphysis pubis, and to compare the reliability of the ALAT with that of the C7-CSVL. A prospective study at a university hospital was used. The patient sample consisted of sixty-nine consecutively enrolled men and women patients, aged 10-18 years, who had trunk imbalance defined as C7-CSVL longer than 20 mm on computed full-spine standing anterioposterior radiographs. Data were analyzed to determine the correlation between C7-CSVL and ALAT measurements and to determine intraobserver and interobserver reliabilities. Using a picture archiving and communication system, three radiologists independently evaluated trunk imbalance on the 69 computed radiographs by measuring the C7-CSVL and by measuring the angle determined by the ALAT. Data were analyzed to determine the correlations between the two measures of trunk imbalance, and to determine intraobserver and interobserver reliabilities of each of them. Overall results from the measurements by the C7-CSVL and the ALAT were significantly moderately correlated

  10. The 'radiographer-referrer game': image interpretation dynamics in rural practice.

    PubMed

    Squibb, Kathryn; Smith, Anthony; Dalton, Lisa; Bull, Rosalind M

    2016-03-01

    Effective interprofessional communication is intrinsic to safe health care. Despite the identified positive impact of collaborative radiographic interpretation between rural radiographers and referrers, communication difficulties still exist. This article describes the strategies that Australian rural radiographers use for communication of their radiographic opinion to the referring doctor. In a two-phase interpretive doctoral study completed in 2012, data were collected from radiographers working in rural New South Wales, Western Australia and Tasmania using a paper based questionnaire followed by in-depth semistructured interviews. Data were analysed thematically in order to identify, analyse and report the emergent themes. The overarching theme was Patient Advocacy, where in the interest of patient care radiographers took measures to ensure that a referring doctor did not miss radiographic abnormalities. Strong interprofessional relationships enabled direct communication pathways. Interprofessional boundaries shaped by historical hierarchical relationships, together with a lack of confidence and educational preparation for radiographic interpretation result in barriers to direct communication pathways. These barriers prompted radiographers to pursue indirect communication pathways, such as side-stepping and hint and hope. A lack of formal communication pathways and educational preparation for this role has resulted in radiographers playing the radiographer-referrer game to overtly or covertly assist referrers in reaching a radiographic diagnosis. The findings from this study may be used to plan interventions for strengthening interprofessional communication pathways and improve quality of healthcare for patients.

  11. Dual Energy Method for Breast Imaging: A Simulation Study.

    PubMed

    Koukou, V; Martini, N; Michail, C; Sotiropoulou, P; Fountzoula, C; Kalyvas, N; Kandarakis, I; Nikiforidis, G; Fountos, G

    2015-01-01

    Dual energy methods can suppress the contrast between adipose and glandular tissues in the breast and therefore enhance the visibility of calcifications. In this study, a dual energy method based on analytical modeling was developed for the detection of minimum microcalcification thickness. To this aim, a modified radiographic X-ray unit was considered, in order to overcome the limited kVp range of mammographic units used in previous DE studies, combined with a high resolution CMOS sensor (pixel size of 22.5 μm) for improved resolution. Various filter materials were examined based on their K-absorption edge. Hydroxyapatite (HAp) was used to simulate microcalcifications. The contrast to noise ratio (CNR tc ) of the subtracted images was calculated for both monoenergetic and polyenergetic X-ray beams. The optimum monoenergetic pair was 23/58 keV for the low and high energy, respectively, resulting in a minimum detectable microcalcification thickness of 100 μm. In the polyenergetic X-ray study, the optimal spectral combination was 40/70 kVp filtered with 100 μm cadmium and 1000 μm copper, respectively. In this case, the minimum detectable microcalcification thickness was 150 μm. The proposed dual energy method provides improved microcalcification detectability in breast imaging with mean glandular dose values within acceptable levels.

  12. Dual Energy Method for Breast Imaging: A Simulation Study

    PubMed Central

    2015-01-01

    Dual energy methods can suppress the contrast between adipose and glandular tissues in the breast and therefore enhance the visibility of calcifications. In this study, a dual energy method based on analytical modeling was developed for the detection of minimum microcalcification thickness. To this aim, a modified radiographic X-ray unit was considered, in order to overcome the limited kVp range of mammographic units used in previous DE studies, combined with a high resolution CMOS sensor (pixel size of 22.5 μm) for improved resolution. Various filter materials were examined based on their K-absorption edge. Hydroxyapatite (HAp) was used to simulate microcalcifications. The contrast to noise ratio (CNRtc) of the subtracted images was calculated for both monoenergetic and polyenergetic X-ray beams. The optimum monoenergetic pair was 23/58 keV for the low and high energy, respectively, resulting in a minimum detectable microcalcification thickness of 100 μm. In the polyenergetic X-ray study, the optimal spectral combination was 40/70 kVp filtered with 100 μm cadmium and 1000 μm copper, respectively. In this case, the minimum detectable microcalcification thickness was 150 μm. The proposed dual energy method provides improved microcalcification detectability in breast imaging with mean glandular dose values within acceptable levels. PMID:26246848

  13. 21 CFR 892.1860 - Radiographic film/cassette changer.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Radiographic film/cassette changer. 892.1860... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1860 Radiographic film/cassette changer. (a) Identification. A radiographic film/cassette changer is a device intended to be used during a...

  14. 21 CFR 892.1860 - Radiographic film/cassette changer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Radiographic film/cassette changer. 892.1860... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1860 Radiographic film/cassette changer. (a) Identification. A radiographic film/cassette changer is a device intended to be used during a...

  15. 21 CFR 892.1640 - Radiographic film marking system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Radiographic film marking system. 892.1640 Section... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1640 Radiographic film marking system. (a) Identification. A radiographic film marking system is a device intended for medical purposes to...

  16. 21 CFR 892.1860 - Radiographic film/cassette changer.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Radiographic film/cassette changer. 892.1860... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1860 Radiographic film/cassette changer. (a) Identification. A radiographic film/cassette changer is a device intended to be used during a...

  17. 21 CFR 892.1640 - Radiographic film marking system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Radiographic film marking system. 892.1640 Section... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1640 Radiographic film marking system. (a) Identification. A radiographic film marking system is a device intended for medical purposes to...

  18. 21 CFR 892.1640 - Radiographic film marking system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Radiographic film marking system. 892.1640 Section... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1640 Radiographic film marking system. (a) Identification. A radiographic film marking system is a device intended for medical purposes to...

  19. 21 CFR 892.1860 - Radiographic film/cassette changer.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Radiographic film/cassette changer. 892.1860... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1860 Radiographic film/cassette changer. (a) Identification. A radiographic film/cassette changer is a device intended to be used during a...

  20. 21 CFR 892.1640 - Radiographic film marking system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Radiographic film marking system. 892.1640 Section... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1640 Radiographic film marking system. (a) Identification. A radiographic film marking system is a device intended for medical purposes to...

  1. 21 CFR 892.1640 - Radiographic film marking system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radiographic film marking system. 892.1640 Section... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1640 Radiographic film marking system. (a) Identification. A radiographic film marking system is a device intended for medical purposes to...

  2. 21 CFR 892.1860 - Radiographic film/cassette changer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radiographic film/cassette changer. 892.1860... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1860 Radiographic film/cassette changer. (a) Identification. A radiographic film/cassette changer is a device intended to be used during a...

  3. Is radiographic measurement of bony landmarks reliable for lateral meniscal sizing?

    PubMed

    Yoon, Jung-Ro; Kim, Taik-Seon; Lim, Hong-Chul; Lim, Hyung-Tae; Yang, Jae-Hyuk

    2011-03-01

    The accuracy of meniscal measurement methods is still in debate. The authors' protocol for radiologic measurements will provide reproducible bony landmarks, and this measurement method of the lateral tibial plateau will correlate with the actual anatomic value. Controlled laboratory study. Twenty-five samples of fresh lateral meniscus with attached proximal tibia were obtained during total knee arthroplasty. Each sample was obtained without damage to the meniscus and bony attachment sites. The inclusion criterion was mild to moderate osteoarthritis in patients with mechanical axis deviation of less than 15°. Knees with lateral compartment osteoarthritic change or injured or degenerated menisci were excluded. For the lateral tibial plateau length measurements, the radiographic beam was angled 10° caudally at neutral rotation, which allowed differentiation of the lateral plateau cortical margins from the medial plateau. The transition points were identified and used for length measurement. The values of length were then compared with the conventional Pollard method and the anatomic values. The width measurement was done according to Pollard's protocol. For each knee, the percentage deviation from the anatomic dimension was recorded. Intraobserver error and interobserver error were calculated. The deviation of the authors' radiographic length measurements from anatomic dimensions was 1.4 ± 1.1 mm. The deviation of Pollard's radiographic length measurements was 4.1 ± 2.0 mm. With respect to accuracy-which represents the frequency of measurements that fall within 10% of measurements-the accuracy of authors' length was 98%, whereas for Pollard's method it was 40%. There was a good correlation between anatomic meniscal dimensions and each radiologic plateau dimensions for lateral meniscal width (R(2) = .790) and the authors' lateral meniscal length (R(2) = .823) and fair correlation for Pollard's lateral meniscal length (R(2) = .660). The reliability of each

  4. Evaluation of the optical axis tilt of zinc oxide films via noncollinear second harmonic generation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bovino, F. A.; Larciprete, M. C.; Belardini, A.

    2009-06-22

    We investigated noncollinear second harmonic generation form zinc oxide films, grown on glass substrates by dual ion beam sputtering technique. At a fixed incidence angle, the generated signal is investigated by scanning the polarization state of both fundamental beams. We show that the map of the generated signal as a function of polarization states of both pump beams, together with the analytical curves, allows to retrieve the orientation of the optical axis and eventually, its angular tilt, with respect to the surface normal.

  5. Radiographic identification of the equine ventral conchal bulla.

    PubMed

    Finnegan, C M; Townsend, N B; Barnett, T P; Barakzai, S Z

    Involvement of the ventral conchal sinus (VCS) is an important diagnostic and prognostic feature in cases of the equine sinus disease. The authors aimed to ascertain if the caudo-dorsal extension of the VCS, the ventral conchal bulla (VCB) is identifiable on plain radiographs of cadaver skulls without sinus disease. Bilateral frontonasal sinus flaps were made in 10 equine cadaver skulls. Plain lateral, lateral oblique and dorso-ventral radiographs were then obtained followed by the same views taken with stainless steel wire outlining the caudal border of the VCB. Plain radiographs were randomised and blindly evaluated by two observers who marked where they believed the VCB to be positioned. This was then correlated with the true position of the VCB using radiographs with wires in place. The ease of identification of the VCB was classified as 'easy' or 'difficult'. The VCB was correctly identified in 70 per cent of lateral radiographs, but only 45 per cent of lateral oblique radiographs and 17 per cent of dorso-ventral radiographs. If a clinician was confident that he or she could identify the VCB, they were usually correct. Conversely if the clinician judged VCB identification as 'difficult', they usually identified it incorrectly. In the authors' clinical experience, the VCB of horses with sinusitis involving this compartment is more radiologically evident than in clinically normal horses. Knowledge of the normal radiographic anatomy of this structure should aid clinicians in identifying horses with sinusitis affecting the VCS.

  6. 21 CFR 892.1910 - Radiographic grid.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radiographic grid. 892.1910 Section 892.1910 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1910 Radiographic grid. (a) Identification. A...

  7. Nonlinear dual-axis biodynamic response of the semi-supine human body during longitudinal horizontal whole-body vibration

    NASA Astrophysics Data System (ADS)

    Huang, Ya; Griffin, Michael J.

    2008-04-01

    The resonance frequencies in frequency response functions of the human body (e.g. apparent mass and transmissibility) decrease with increasing vibration magnitude. This nonlinear biodynamic response is found with various sitting and standing postures requiring postural control. The present study measured the apparent mass of the body in a relaxed semi-supine posture with two types of longitudinal horizontal vibration (in the z-axis of the semi-supine body): (i) continuous random excitation (0.25-20 Hz) at five magnitudes (0.125, 0.25, 0.5, 0.75 and 1.0 ms -2 rms); (ii) intermittent random excitation (0.25-20 Hz) alternately at 0.25 and 1.0 ms -2 rms. With continuous random vibration, the dominant primary resonance frequency in the median normalised apparent mass decreased from 3.7 to 2.4 Hz as the vibration magnitude increased from 0.125 to 1.0 ms -2 rms. A nonlinear response was apparent in both the horizontal ( z-axis) apparent mass and the vertical ( x-axis) cross-axis apparent mass. With intermittent random vibration, as the vibration magnitude increased from 0.25 to 1.0 ms -2 rms, the median resonance frequency of the apparent mass decreased from 3.2 to 2.5 Hz whereas, with continuous random vibration over the same range of magnitudes, the resonance frequency decreased from 3.4 to 2.4 Hz. The median change in the resonance frequency (between 0.25 and 1.0 ms -2 rms) was 0.6 Hz with the intermittent random vibration and 0.9 Hz with the continuous random vibration. With intermittent vibration, the resonance frequency was higher at the high magnitude and lower at the low magnitude than with continuous vibration at the same magnitudes. The responses were consistent with passive thixotropy being a primary cause of nonlinear biodynamic responses to whole-body vibration, although reflex activity of the muscles may also have an influence.

  8. 21 CFR 892.1960 - Radiographic intensifying screen.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    .... (a) Identification. A radiographic intensifying screen is a device that is a thin radiolucent sheet... for medical purposes to expose radiographic film. (b) Classification. Class I (general controls). The...

  9. Vertical intensity modulation for improved radiographic penetration and reduced exclusion zone

    NASA Astrophysics Data System (ADS)

    Bendahan, J.; Langeveld, W. G. J.; Bharadwaj, V.; Amann, J.; Limborg, C.; Nosochkov, Y.

    2016-09-01

    In the present work, a method to direct the X-ray beam in real time to the desired locations in the cargo to increase penetration and reduce exclusion zone is presented. Cargo scanners employ high energy X-rays to produce radiographic images of the cargo. Most new scanners employ dual-energy to produce, in addition to attenuation maps, atomic number information in order to facilitate the detection of contraband. The electron beam producing the bremsstrahlung X-ray beam is usually directed approximately to the center of the container, concentrating the highest X-ray intensity to that area. Other parts of the container are exposed to lower radiation levels due to the large drop-off of the bremsstrahlung radiation intensity as a function of angle, especially for high energies (>6 MV). This results in lower penetration in these areas, requiring higher power sources that increase the dose and exclusion zone. The capability to modulate the X-ray source intensity on a pulse-by-pulse basis to deliver only as much radiation as required to the cargo has been reported previously. This method is, however, controlled by the most attenuating part of the inspected slice, resulting in excessive radiation to other areas of the cargo. A method to direct a dual-energy beam has been developed to provide a more precisely controlled level of required radiation to highly attenuating areas. The present method is based on steering the dual-energy electron beam using magnetic components on a pulse-to-pulse basis to a fixed location on the X-ray production target, but incident at different angles so as to direct the maximum intensity of the produced bremsstrahlung to the desired locations. The details of the technique and subsystem and simulation results are presented.

  10. Quantifying Spot Size Reduction of a 1.8 kA Electron Beam for Flash Radiography

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Burris-Mog, Trevor John; Moir, David C.

    The spot size of Axis-I at the Dual Axis Radiographic Hydrodynamic Test facility was reduced by 15.5% by including a small diameter drift tube that acts to aperture the outer diameter of the electron beam. Comparing the measured values to both analytic calculations and results from a particle-in-cell model shows that one-third to one-half of the spot size reduction is due to a drop in beam emittance. We infer that one-half to two-thirds of the spot-size reduction is due to a reduction in beam-target interactions. Sources of emittance growth and the scaling of the final focal spot size with emittancemore » and solenoid aberrations are also presented.« less

  11. Quantifying Spot Size Reduction of a 1.8 kA Electron Beam for Flash Radiography

    DOE PAGES

    Burris-Mog, Trevor John; Moir, David C.

    2018-03-14

    The spot size of Axis-I at the Dual Axis Radiographic Hydrodynamic Test facility was reduced by 15.5% by including a small diameter drift tube that acts to aperture the outer diameter of the electron beam. Comparing the measured values to both analytic calculations and results from a particle-in-cell model shows that one-third to one-half of the spot size reduction is due to a drop in beam emittance. We infer that one-half to two-thirds of the spot-size reduction is due to a reduction in beam-target interactions. Sources of emittance growth and the scaling of the final focal spot size with emittancemore » and solenoid aberrations are also presented.« less

  12. Chest radiographs for acute lower respiratory tract infections.

    PubMed

    Cao, Amy Millicent Y; Choy, Joleen P; Mohanakrishnan, Lakshmi Narayana; Bain, Roger F; van Driel, Mieke L

    2013-12-26

    Acute lower respiratory tract infections (LRTIs) (e.g. pneumonia) are a major cause of morbidity and mortality and management focuses on early treatment. Chest radiographs (X-rays) are one of the commonly used strategies. Although radiological facilities are easily accessible in high-income countries, access can be limited in low-income countries. The efficacy of chest radiographs as a tool in the management of acute LRTIs has not been determined. Although chest radiographs are used for both diagnosis and management, our review focuses only on management. To assess the effectiveness of chest radiographs in addition to clinical judgement, compared to clinical judgement alone, in the management of acute LRTIs in children and adults. We searched CENTRAL 2013, Issue 1; MEDLINE (1948 to January week 4, 2013); EMBASE (1974 to February 2013); CINAHL (1985 to February 2013) and LILACS (1985 to February 2013). We also searched NHS EED, DARE, ClinicalTrials.gov and WHO ICTRP (up to February 2013). Randomised controlled trials (RCTs) of chest radiographs versus no chest radiographs in acute LRTIs in children and adults. Two review authors independently applied the inclusion criteria, extracted data and assessed risk of bias. A third review author compiled the findings and any discrepancies were discussed among all review authors. We used the standard methodological procedures expected by The Cochrane Collaboration. Two RCTs involving 2024 patients (1502 adults and 522 children) were included in this review. Both RCTs excluded patients with suspected severe disease. It was not possible to pool the results due to incomplete data. Both included trials concluded that the use of chest radiographs did not result in a better clinical outcome (duration of illness and of symptoms) for patients with acute LRTIs. In the study involving children in South Africa, the median time to recovery was seven days (95% confidence interval (CI) six to eight days (radiograph group) and six to nine

  13. Dental radiographic guidelines: a review.

    PubMed

    Kim, Irene H; Mupparapu, Muralidhar

    2009-05-01

    The 2004 American Dental Association (ADA)/US Food and Drug Administration (FDA) radiographic selection criteria and guidelines were reviewed and compared with the prior radiographic selection criteria and guidelines. The authors reviewed the publications from the US FDA, US Department of Health and Human Services, and National Council on Radiation Protection and Measurements. The positions outlined by the Canadian Dental Association and the European Commission were also reviewed and compared to US guidelines. The FDA guidelines were first published in 1987, and several changes have been made to them over the years. Recent literature reveals that the general compliance of these guidelines is very low, especially within dental schools in the United States and Canada. Little is known about the compliance outside of the dental school environment; however, it is expected to be low for various reasons. In 2007, the International Commission on Radiological Protection (ICRP) revised its estimates of tissue radiosensitivity, which resulted in effective doses of dental radiographs 32% to 422% higher than the 1990 ICRP guidelines. Flow charts summarizing the latest guidelines were developed to facilitate general compliance among practitioners. Based on the literature reviewed and the recent ICRP findings, it would be prudent for dental health care professionals to follow dental radiographic guidelines.

  14. Adult sail sign: radiographic and computed tomographic features.

    PubMed

    Lee, Yu-Jin; Han, Daehee; Koh, Young Hwan; Zo, Joo Hee; Kim, Sang-Hyun; Kim, Deog Kyeom; Lee, Jeong Sang; Moon, Hyeon Jong; Kim, Jong Seung; Chun, Eun Ju; Youn, Byung Jae; Lee, Chang Hyun; Kim, Sam Soo

    2008-02-01

    The sail sign is a well-known radiographic feature of the pediatric chest. This sign can be observed in an adult population as well, but for a different reason. To investigate the sail sign appearing in adult chest radiography. Based on two anecdotal adult cases in which frontal chest radiographs showed the sail sign, we prospectively screened radiographs of 10,238 patients to determine the incidence of the sail sign found in adults in their 40s or older. The cause of the sail sign was assessed using computed tomography (CT). The sail sign was revealed in 10 (seven males, three females; median age 60.6 years) of 10,238 patients. Of these 10 patients with a sail sign on frontal radiographs, eight underwent CT. The frontal radiographs of these 10 patients showed a concave superior margin toward the lung in nine patients, a concave inferior margin in five, and a double-lined inferior margin in three. Lateral radiographs disclosed a focal opacity over the minor fissure in five of six patients, which was either fuzzy (n = 4) or sharp (n = 1) in its upper margin, and was sometimes double lined in the inferior margin (n = 3). CT revealed the anterior mediastinal fat to be the cause of the radiographic sail sign, which stretched laterally from the mediastinum to insinuate into the minor fissure. The incidence of sail sign on adult chest radiographs is about 0.1%. The sign is specific enough to eliminate the need for more sophisticated imaging.

  15. Magnification of digital hip radiographs differs between clinical workplaces.

    PubMed

    Hornová, Jana; Růžička, Pavel; Hrubina, Maroš; Šťastný, Eduard; Košková, Andrea; Fulín, Petr; Gallo, Jiří; Daniel, Matej

    2017-01-01

    Preoperative planning for total hip arthroplasty includes templating on anteroposterior radiographs. It is necessary to consider radiographic magnification in order to scale templates accurately. Studies dealing with hip templating report different values of radiographic magnification. It is not clear if the observed difference in magnification between the studies is caused by variability in studied groups, methodology or instrumentation. We hypothesize that there is a difference in magnification between clinical workplaces. Within this study, radiographic magnification was estimated on 337 radiographs of patients after total hip surgery from five orthopaedic departments in the Czech Republic. Magnification was determined for each patient as a ratio between diameter of implanted femoral head measured on radiogram and its true size. One-way ANOVA revealed significant differences in magnification between workplaces (F(4,332) = 132, p≤0.001). These results suggest that radiographic magnification depends on the workplace where it is taken or more precisely on radiographic device. It indicates potential limits in generalizability of results of studies dealing with preoperative planning accuracy to other institutions.

  16. Kynurenine pathway metabolism and the microbiota-gut-brain axis.

    PubMed

    Kennedy, P J; Cryan, J F; Dinan, T G; Clarke, G

    2017-01-01

    It has become increasingly clear that the gut microbiota influences not only gastrointestinal physiology but also central nervous system (CNS) function by modulating signalling pathways of the microbiota-gut-brain axis. Understanding the neurobiological mechanisms underpinning the influence exerted by the gut microbiota on brain function and behaviour has become a key research priority. Microbial regulation of tryptophan metabolism has become a focal point in this regard, with dual emphasis on the regulation of serotonin synthesis and the control of kynurenine pathway metabolism. Here, we focus in detail on the latter pathway and begin by outlining the structural and functional dynamics of the gut microbiota and the signalling pathways of the brain-gut axis. We summarise preclinical and clinical investigations demonstrating that the gut microbiota influences CNS physiology, anxiety, depression, social behaviour, cognition and visceral pain. Pertinent studies are drawn from neurogastroenterology demonstrating the importance of tryptophan and its metabolites in CNS and gastrointestinal function. We outline how kynurenine pathway metabolism may be regulated by microbial control of neuroendocrine function and components of the immune system. Finally, preclinical evidence demonstrating direct and indirect mechanisms by which the gut microbiota can regulate tryptophan availability for kynurenine pathway metabolism, with downstream effects on CNS function, is reviewed. Targeting the gut microbiota represents a tractable target to modulate kynurenine pathway metabolism. Efforts to develop this approach will markedly increase our understanding of how the gut microbiota shapes brain and behaviour and provide new insights towards successful translation of microbiota-gut-brain axis research from bench to bedside. This article is part of the Special Issue entitled 'The Kynurenine Pathway in Health and Disease'. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. 21 CFR 892.1850 - Radiographic film cassette.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...) Identification. A radiographic film cassette is a device intended for use during diagnostic x-ray procedures to hold a radiographic film in close contact with an x-ray intensifying screen and to provide a light...

  18. 2D–3D radiograph to cone-beam computed tomography (CBCT) registration for C-arm image-guided robotic surgery

    PubMed Central

    Liu, Wen Pei; Otake, Yoshito; Azizian, Mahdi; Wagner, Oliver J.; Sorger, Jonathan M.; Armand, Mehran; Taylor, Russell H.

    2015-01-01

    Purpose C-arm radiographs are commonly used for intraoperative image guidance in surgical interventions. Fluoroscopy is a cost-effective real-time modality, although image quality can vary greatly depending on the target anatomy. Cone-beam computed tomography (CBCT) scans are sometimes available, so 2D–3D registration is needed for intra-procedural guidance. C-arm radiographs were registered to CBCT scans and used for 3D localization of peritumor fiducials during a minimally invasive thoracic intervention with a da Vinci Si robot. Methods Intensity-based 2D–3D registration of intraoperative radiographs to CBCT was performed. The feasible range of X-ray projections achievable by a C-arm positioned around a da Vinci Si surgical robot, configured for robotic wedge resection, was determined using phantom models. Experiments were conducted on synthetic phantoms and animals imaged with an OEC 9600 and a Siemens Artis zeego, representing the spectrum of different C-arm systems currently available for clinical use. Results The image guidance workflow was feasible using either an optically tracked OEC 9600 or a Siemens Artis zeego C-arm, resulting in an angular difference of Δθ : ~ 30°. The two C-arm systems provided TREmean ≤ 2.5 mm and TREmean ≤ 2.0 mm, respectively (i.e., comparable to standard clinical intraoperative navigation systems). Conclusions C-arm 3D localization from dual 2D–3D registered radiographs was feasible and applicable for intraoperative image guidance during da Vinci robotic thoracic interventions using the proposed workflow. Tissue deformation and in vivo experiments are required before clinical evaluation of this system. PMID:25503592

  19. Threatened and Endangered Species Habitat Management Plan for Los Alamos National Laboratory

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hathcock, Charles Dean; Keller, David Charles; Thompson, Brent E.

    Los Alamos National Laboratory’s (LANL) Threatened and Endangered Species Habitat Management Plan (HMP) fulfills a commitment made to the U.S. Department of Energy (DOE) in the “Final Environmental Impact Statement for the Dual-Axis Radiographic Hydrodynamic Test Facility Mitigation Action Plan” (DOE 1996). The HMP received concurrence from the U.S. Fish and Wildlife Service (USFWS) in 1999 (USFWS consultation numbers 2-22-98-I-336 and 2-22-95-I-108). This 2017 update retains the management guidelines from the 1999 HMP for listed species, and updates some descriptive information.

  20. Bone images from dual-energy subtraction chest radiography in the detection of rib fractures.

    PubMed

    Szucs-Farkas, Zsolt; Lautenschlager, Katrin; Flach, Patricia M; Ott, Daniel; Strautz, Tamara; Vock, Peter; Ruder, Thomas D

    2011-08-01

    To assess the sensitivity and image quality of chest radiography (CXR) with or without dual-energy subtracted (ES) bone images in the detection of rib fractures. In this retrospective study, 39 patients with 204 rib fractures and 24 subjects with no fractures were examined with a single exposure dual-energy subtraction digital radiography system. Three blinded readers first evaluated the non-subtracted posteroanterior and lateral chest radiographs alone, and 3 months later they evaluated the non-subtracted images together with the subtracted posteroanterior bone images. The locations of rib fractures were registered with confidence levels on a 3-grade scale. Image quality was rated on a 5-point scale. Marks by readers were compared with fracture localizations in CT as a standard of reference. The sensivity for fracture detection using both methods was very similar (34.3% with standard CXR and 33.5% with ES-CXR, p=0.92). At the patient level, both sensitivity (71.8%) and specificity (92.9%) with or without ES were identical. Diagnostic confidence was not significantly different (2.61 with CXR and 2.75 with ES-CXR, p=0.063). Image quality with ES was rated higher than that on standard CXR (4.08 vs. 3.74, p<0.001). Despite a better image quality, adding ES bone images to standard radiographs of the chest does not provide better sensitivity or improved diagnostic confidence in the detection of rib fractures. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  1. Targeted vertical cross-sectional imaging with handheld near-infrared dual axes confocal fluorescence endomicroscope.

    PubMed

    Qiu, Zhen; Liu, Zhongyao; Duan, Xiyu; Khondee, Supang; Joshi, Bishnu; Mandella, Michael J; Oldham, Kenn; Kurabayashi, Katsuo; Wang, Thomas D

    2013-02-01

    We demonstrate vertical cross-sectional (XZ-plane) images of near-infrared (NIR) fluorescence with a handheld dual axes confocal endomicroscope that reveals specific binding of a Cy5.5-labeled peptide to pre-malignant colonic mucosa. This view is perpendicular to the tissue surface, and is similar to that used by pathologists. The scan head is 10 mm in outer diameter (OD), and integrates a one dimensional (1-D) microelectromechanical systems (MEMS) X-axis scanner and a bulky lead zirconate titanate (PZT) based Z-axis actuator. The microscope images in a raster-scanning pattern with a ±6 degrees (mechanical) scan angle at ~3 kHz in the X-axis (fast) and up to 10 Hz (0-400 μm) in the Z-axis (slow). Vertical cross-sectional fluorescence images are collected with a transverse and axial resolution of 4 and 5 μm, respectively, over a field-of-view of 800 μm (width) × 400 μm (depth). NIR vertical cross-sectional fluorescence images of fresh mouse colonic mucosa demonstrate histology-like imaging performance with this miniature instrument.

  2. Targeted vertical cross-sectional imaging with handheld near-infrared dual axes confocal fluorescence endomicroscope

    PubMed Central

    Qiu, Zhen; Liu, Zhongyao; Duan, Xiyu; Khondee, Supang; Joshi, Bishnu; Mandella, Michael J.; Oldham, Kenn; Kurabayashi, Katsuo; Wang, Thomas D.

    2013-01-01

    We demonstrate vertical cross-sectional (XZ-plane) images of near-infrared (NIR) fluorescence with a handheld dual axes confocal endomicroscope that reveals specific binding of a Cy5.5-labeled peptide to pre-malignant colonic mucosa. This view is perpendicular to the tissue surface, and is similar to that used by pathologists. The scan head is 10 mm in outer diameter (OD), and integrates a one dimensional (1-D) microelectromechanical systems (MEMS) X-axis scanner and a bulky lead zirconate titanate (PZT) based Z-axis actuator. The microscope images in a raster-scanning pattern with a ±6 degrees (mechanical) scan angle at ~3 kHz in the X-axis (fast) and up to 10 Hz (0–400 μm) in the Z-axis (slow). Vertical cross-sectional fluorescence images are collected with a transverse and axial resolution of 4 and 5 μm, respectively, over a field-of-view of 800 μm (width) × 400 μm (depth). NIR vertical cross-sectional fluorescence images of fresh mouse colonic mucosa demonstrate histology-like imaging performance with this miniature instrument. PMID:23412564

  3. Digital image analysis: improving accuracy and reproducibility of radiographic measurement.

    PubMed

    Bould, M; Barnard, S; Learmonth, I D; Cunningham, J L; Hardy, J R

    1999-07-01

    To assess the accuracy and reproducibility of a digital image analyser and the human eye, in measuring radiographic dimensions. We experimentally compared radiographic measurement using either an image analyser system or the human eye with digital caliper. The assessment of total hip arthroplasty wear from radiographs relies on both the accuracy of radiographic images and the accuracy of radiographic measurement. Radiographs were taken of a slip gauge (30+/-0.00036 mm) and slip gauge with a femoral stem. The projected dimensions of the radiographic images were calculated by trigonometry. The radiographic dimensions were then measured by blinded observers using both techniques. For a single radiograph, the human eye was accurate to 0.26 mm and reproducible to +/-0.1 mm. In comparison the digital image analyser system was accurate to 0.01 mm with a reproducibility of +/-0.08 mm. In an arthroplasty model, where the dimensions of an object were corrected for magnification by the known dimensions of a femoral head, the human eye was accurate to 0.19 mm, whereas the image analyser system was accurate to 0.04 mm. The digital image analysis system is up to 20 times more accurate than the human eye, and in an arthroplasty model the accuracy of measurement increases four-fold. We believe such image analysis may allow more accurate and reproducible measurement of wear from standard follow-up radiographs.

  4. Measurement of lung volumes from supine portable chest radiographs.

    PubMed

    Ries, A L; Clausen, J L; Friedman, P J

    1979-12-01

    Lung volumes in supine nonambulatory patients are physiological parameters often difficult to measure with current techniques (plethysmograph, gas dilution). Existing radiographic methods for measuring lung volumes require standard upright chest radiographs. Accordingly, in 31 normal supine adults, we determined helium-dilution functional residual and total lung capacities and measured planimetric lung field areas (LFA) from corresponding portable anteroposterior and lateral radiographs. Low radiation dose methods, which delivered less than 10% of that from standard portable X-ray technique, were utilized. Correlation between lung volume and radiographic LFA was highly significant (r = 0.96, SEE = 10.6%). Multiple-step regressions using height and chest diameter correction factors reduced variance, but weight and radiographic magnification factors did not. In 17 additional subjects studied for validation, the regression equations accurately predicted radiographic lung volume. Thus, this technique can provide accurate and rapid measurement of lung volume in studies involving supine patients.

  5. A radiographic and tomographic imaging system integrated into a medical linear accelerator for localization of bone and soft-tissue targets.

    PubMed

    Jaffray, D A; Drake, D G; Moreau, M; Martinez, A A; Wong, J W

    1999-10-01

    Dose escalation in conformal radiation therapy requires accurate field placement. Electronic portal imaging devices are used to verify field placement but are limited by the low subject contrast of bony anatomy at megavoltage (MV) energies, the large imaging dose, and the small size of the radiation fields. In this article, we describe the in-house modification of a medical linear accelerator to provide radiographic and tomographic localization of bone and soft-tissue targets in the reference frame of the accelerator. This system separates the verification of beam delivery (machine settings, field shaping) from patient and target localization. A kilovoltage (kV) x-ray source is mounted on the drum assembly of an Elekta SL-20 medical linear accelerator, maintaining the same isocenter as the treatment beam with the central axis at 90 degrees to the treatment beam axis. The x-ray tube is powered by a high-frequency generator and can be retracted to the drum-face. Two CCD-based fluoroscopic imaging systems are mounted on the accelerator to collect MV and kV radiographic images. The system is also capable of cone-beam tomographic imaging at both MV and kV energies. The gain stages of the two imaging systems have been modeled to assess imaging performance. The contrast-resolution of the kV and MV systems was measured using a contrast-detail (C-D) phantom. The dosimetric advantage of using the kV imaging system over the MV system for the detection of bone-like objects is quantified for a specific imaging geometry using a C-D phantom. Accurate guidance of the treatment beam requires registration of the imaging and treatment coordinate systems. The mechanical characteristics of the treatment and imaging gantries are examined to determine a localizing precision assuming an unambiguous object. MV and kV radiographs of patients receiving radiation therapy are acquired to demonstrate the radiographic performance of the system. The tomographic performance is demonstrated on

  6. Wide-beam sensors for controlling dual-delay systems

    NASA Astrophysics Data System (ADS)

    Edwards, J. B.; Twemlow, J. K.

    1982-09-01

    A class of dual delay feedback systems of open loop transfer function G(s) = k exp(-Xs)/l - exp(-Ws) is shown to be unstable if ratio X/W is noninteger. By means of z-transform techniques it is shown that, by using a feedback transducer that senses over a substantial distance either side of its central axis, closed-loop stability may be restored. Such transducers, termed widebeam sensors, include transmission, backscatter and natural radiation types as well as electromechanical conveyor belt weighers. Designing transducers for very narrow beams may not be desirable from the overall system viewpoint.

  7. Risk Factors for Proximal Junctional Kyphosis Associated With Dual-rod Growing-rod Surgery for Early-onset Scoliosis.

    PubMed

    Watanabe, Kota; Uno, Koki; Suzuki, Teppei; Kawakami, Noriaki; Tsuji, Taichi; Yanagida, Haruhisa; Ito, Manabu; Hirano, Toru; Yamazaki, Ken; Minami, Shohei; Taneichi, Hiroshi; Imagama, Shiro; Takeshita, Katsushi; Yamamoto, Takuya; Matsumoto, Morio

    2016-10-01

    A retrospective, multicenter study. To identify risk factors for proximal junctional kyphosis (PJK) when treating early-onset scoliosis (EOS) with dual-rod growing-rod (GR) procedure. The risk factors for PJK associated with GR treatment for EOS have not been adequately studied. We evaluated clinical and radiographic results from 88 patients with EOS who underwent dual-rod GR surgery in 12 spine centers in Japan. The mean age at the time of the initial surgery was 6.5±2.2 years (range, 1.5-9.8 y), and the mean follow-up period was 3.9±2.6 years (range, 2.0-12.0 y). Risk factors for PJK were analyzed by binomial multiple logistic regression analysis. The potential factors analyzed were sex, etiology, age, the number of rod-lengthening procedures, coronal and sagittal parameters on radiographs, the type of foundation (pedicle screws or hooks), the uppermost level of the proximal foundation, and the lowermost level of the distal foundation. PJK developed in 23 patients (26%); in 19 of these, the proximal foundation became dislodged following PJK. Binomial multiple logistic regression analysis identified the following significant independent risk factors for PJK: a lower instrumented vertebra at or cranial to L3 [odds ratio (OR), 3.32], a proximal thoracic scoliosis of ≥40 degrees (OR, 2.95), and a main thoracic kyphosis of ≥60 degrees (OR, 5.08). The significant independent risk factors for PJK during dual-rod GR treatment for EOS were a lower instrumented vertebra at or cranial to L3, a proximal thoracic scoliosis of ≥40 degrees, and a main thoracic kyphosis of ≥60 degrees.

  8. 21 CFR 892.1870 - Radiographic film/cassette changer programmer.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Radiographic film/cassette changer programmer. 892... SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1870 Radiographic film/cassette changer programmer. (a) Identification. A radiographic film/cassette changer programmer is a...

  9. 21 CFR 892.1870 - Radiographic film/cassette changer programmer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Radiographic film/cassette changer programmer. 892... SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1870 Radiographic film/cassette changer programmer. (a) Identification. A radiographic film/cassette changer programmer is a...

  10. 21 CFR 892.1870 - Radiographic film/cassette changer programmer.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Radiographic film/cassette changer programmer. 892... SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1870 Radiographic film/cassette changer programmer. (a) Identification. A radiographic film/cassette changer programmer is a...

  11. 21 CFR 892.1870 - Radiographic film/cassette changer programmer.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Radiographic film/cassette changer programmer. 892... SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1870 Radiographic film/cassette changer programmer. (a) Identification. A radiographic film/cassette changer programmer is a...

  12. 21 CFR 892.1870 - Radiographic film/cassette changer programmer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radiographic film/cassette changer programmer. 892... SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1870 Radiographic film/cassette changer programmer. (a) Identification. A radiographic film/cassette changer programmer is a...

  13. A novel method for defining the Greyhound talocrural joint axis of rotation for hinged transarticular external skeletal fixation.

    PubMed

    Colborne, G R; Hadley, N R; Wallace, A M

    2013-01-01

    In order to apply hinged transarticular external skeletal fixation for stabilization of the injured canine tarsal joint, knowledge of the three-dimensional (3D) location and orientation of the transverse axis is necessary. This method of immobilization may be used as a primary or adjunctive method of stabilisation for a large number of traumatic conditions. Using pin-mounted markers in the cadaveric Greyhound crus and talus, a closed-form solution of absolute orientation was used to identify, on radiographs, the lateral and medial locations of the transverse axis by tracking the 3D excursions of the markers during flexion and extension. A line was drawn across the dorsal aspect of the calcaneus from the most dorsal point on the distal articular surface(proximal intertarsal joint: PIJ) to the most dorsal point on its proximal articulation with the body of the talus, and the location of the centre of rotation was expressed in terms of the length of that line. In seven Greyhound tarsal joints, the medial end of the axis was located 73 ± 10% proximal to the PIJ and 11 ± 7% dorsal to the line. The lateral end was 73 ± 9% proximal tothe PIJ and -2 ± 3% plantar to the line.

  14. Film holder for radiographing tubing

    DOEpatents

    Davis, Earl V.; Foster, Billy E.

    1976-01-01

    A film cassette is provided which may be easily placed about tubing or piping and readily held in place while radiographic inspection is performed. A pair of precurved light-impervious semi-rigid plastic sheets, hinged at one edge, enclose sheet film together with any metallic foils or screens. Other edges are made light-tight with removable caps, and the entire unit is held securely about the object to be radiographed with a releasable fastener such as a strip of Velcro.

  15. Radiographers' performance in chest X-ray interpretation: the Nigerian experience

    PubMed Central

    Egbe, N O; Akpan, B E

    2015-01-01

    Objective: To assess the performance of Nigerian radiographers in interpretation of plain chest radiographs and to assess whether age, years since qualification and sector of practice are associated with performance. Methods: A test set of 50 radiographs containing 23 cases with no pathology (normal) and 27 abnormal cases (cardiopulmonary conditions) independently confirmed by 3 radiologists were presented to 51 radiographers in a random order. Readers independently evaluated radiographs for absence or presence of disease and stated the location, radiographic features and diagnosis. Readers self-reported their age, years since qualification and sector of practice. Receiver operating characteristic was used to assess the performance. Mann–Whitney U test was used to assess whether age, years since qualification and sector of practice were associated with performance. Results: Mean location sensitivity was 88.9 [95% confidence interval (CI), 0.787–0.980]. Mean sensitivity and specificity were 76.9 (95% CI, 0.658–0.864) and 79.8 (95% CI, 0.658–0.864), respectively. Age was not associated with performance (p = 0.07). Number of years qualified as radiographer (p = 0.005) and private practice (p = 0.004) were positively associated with performance. Conclusion: Nigerian radiographers can correctly report chest radiographs to a reasonable standard, and performance is associated with number of years since qualification and the sector of practice. Advances in knowledge: There are less than 300 radiologists serving a Nigerian population of about 170 million; therefore, X-ray interpretation by radiographers deserves consideration. Nigerian radiographers have potential to interpret chest X-ray in the clinical setting, and this may significantly improve radiology service delivery in this region. PMID:25966290

  16. Radiographic findings in pulmonary hypertension from unresolved embolism

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Woodruff, W.W. III; Hoeck, B.E.; Chitwood, W.R. Jr.

    1985-04-01

    Pulmonary artery hypertension with chronic pulmonary embolism is an uncommon entity that is potentially treatable with pulmonary embolectomy. Although the classic radiographic features have been described, several recent investigators report a significant percentage of these patients with normal chest radiographs. In a series of 22 patients, no normal radiographs were seen. Findings included cardiomegaly (86.4%) with right-sided enlargement (68.4%), right descending pulmonary artery enlargement (54.5%), azygos vein enlargement (27.3%), mosaic oligemia (68.2%), chronic volume loss (27.3%), atelectasis and/or effusion (22.7%), and pleural thickening (13.6%). Good correlation with specific areas of diminished vascularity was seen on chest radiographs compared with pulmonarymore » angiograms.« less

  17. Qualification of a High Accuracy Dual-Axis Antenna Deployment and Trimming Mechanism

    NASA Technical Reports Server (NTRS)

    Gossant, Alain; Morichon, Francois

    2010-01-01

    The Antenna Deployment and Trimming Mechanism Mark 2 (ADTM Mk2) has been developed to answer today's need for a generic antenna deployment and high accuracy pointing mechanism, allowing RF sensing applications and easier dual deployments configurations. This paper presents the design and evolution from its predecessor, the experience of the design team from kick off to qualification and batch manufacture, as well as some lessons learned from ramping up "mass-production" capabilities while implementing customer driven changes. Astrium has manufactured and flown ADTM units for the past 20 years, from an initial deployment-only mechanism developed for the Orion program to today's Eurostar E3000 ADTM family. The Antenna ADTM Mk2 is an evolution of the original ADTM Mk1. Although it uses Mk1 building blocks to minimize risks associated with the development of a new product, it incorporates major evolutions and is the new baseline for Astrium latest generation of Eurostar E3000 telecom satellites.

  18. First faint dual-field off-axis observations in optical long baseline interferometry

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Woillez, J.; Wizinowich, P.; Ragland, S.

    2014-03-10

    Ground-based long baseline interferometers have long been limited in sensitivity in part by the short integration periods imposed by atmospheric turbulence. The first observation fainter than this limit was performed on 2011 January 22 when the Keck Interferometer observed a K = 11.5 target, about 1 mag fainter than its K = 10.3 atmospherically imposed limit; the currently demonstrated limit is K = 12.5. These observations were made possible by the Dual-Field Phase-Referencing (DFPR) instrument, part of the NSF-funded ASTrometry and phase-Referenced Astronomy project; integration times longer than the turbulence time scale are made possible by its ability to simultaneouslymore » measure the real-time effects of the atmosphere on a nearby bright guide star and correct for it on the faint target. We present the implementation of DFPR on the Keck Interferometer. Then, we detail its on-sky performance focusing on the accuracy of the turbulence correction and the resulting fringe contrast stability.« less

  19. Ultrasound for diagnosing radiographically occult scaphoid fracture.

    PubMed

    Kwee, Robert M; Kwee, Thomas C

    2018-04-04

    To systematically review the literature on the performance of ultrasound in diagnosing radiographically occult scaphoid fracture. A systematic search was performed in the MEDLINE and Embase databases. Original studies investigating the performance of ultrasound in diagnosing radiographically occult scaphoid fracture in more than 10 patients were eligible for inclusion. Studies that included both radiographically apparent and occult scaphoid fractures (at initial radiography) were only included if independent data on radiographically occult fractures were reported. Methodological quality of the studies included was assessed using the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) tool. Accuracy data were extracted. Sensitivity and specificity were pooled with a bivariate random-effects model. The inclusion criteria were met by 7 studies; total sample size comprised 314 patients. All studies, except 1, included cortical disruption of the scaphoid in their diagnostic criteria. The sensitivity and specificity of ultrasound in diagnosing radiographically occult scaphoid fracture ranged from 77.8% to 100% and from 71.4% to 100% respectively, with pooled estimates of 85.6% (95% CI: 73.9%, 92.6%) and 83.3% % (95% CI: 72.0%, 90.6%) respectively. Exclusion of two studies with a high risk of bias in any QUADAS-2 domain did not affect the pooled results. Ultrasound can diagnose radiographically occult scaphoid fracture with a fairly high degree of accuracy. Because of its relatively low costs and fairly high sensitivity, ultrasound seems more cost-effective than empiric cast immobilization and may be used when CT and MRI are not readily available.

  20. The value of routine chest radiographs in acute asthma admissions.

    PubMed

    Ismail, Y; Loo, C S; Zahary, M K

    1994-04-01

    We reviewed 116 chest radiographs done in 70 adult asthmatic patients who were admitted to the Hospital Universiti Sains Malaysia from January to December 1989. The chest radiographs were abnormal in 23% of cases. Twelve percent showed hyperinflation and 7% had pneumonia. Eight patients diagnosed clinically to have pneumonia had normal chest radiographs. Seven patients had radiographic findings of conditions which were unsuspected clinically. These included two cases of pneumonia, one case each of fibrosing alveolitis, pneumothorax, pneumomediastinum, mitral stenosis with left ventricular failure and right pleural effusion. In conclusion, we found that significant chest radiograph abnormalities in adult patients admitted for asthma were uncommon although chest radiographs were helpful in detecting complications or coincidental conditions. Chest radiograph is therefore an important investigation in adult asthmatic patients who are admitted. However, considering the cost and the risk of radiation, it should be done only in selective cases rather than as a routine procedure.

  1. Dual-Pump CARS Development and Application to Supersonic Combustion

    NASA Technical Reports Server (NTRS)

    Magnotti, Gaetano; Cutler, Andrew D.

    2012-01-01

    A dual-pump Coherent Anti-Stokes Raman Spectroscopy (CARS) instrument has been developed to obtain simultaneous measurements of temperature and absolute mole fractions of N2, O2 and H2 in supersonic combustion and generate databases for validation and development of CFD codes. Issues that compromised previous attempts, such as beam steering and high irradiance perturbation effects, have been alleviated or avoided. Improvements in instrument precision and accuracy have been achieved. An axis-symmetric supersonic combusting coaxial jet facility has been developed to provide a simple, yet suitable flow to CFD modelers. Approximately one million dual-pump CARS single shots have been collected in the supersonic jet for varying values of flight and exit Mach numbers at several locations. Data have been acquired with a H2 co-flow (combustion case) or a N2 co-flow (mixing case). Results are presented and the effects of the compressibility and of the heat release are discussed.

  2. Mastitis, a Radiographic, Clinical, and Histopathologic Review.

    PubMed

    Cheng, Lin; Reddy, Vijaya; Solmos, Gene; Watkins, Latanja; Cimbaluk, David; Bitterman, Pincas; Ghai, Ritu; Gattuso, Paolo

    2015-01-01

    Mastitis is a benign inflammatory process of the breast with heterogeneous histopathological findings, which clinically and radiographically may mimic a mammary carcinoma. We undertook a retrospective study on 37 cases of mastitis in our institution to correlate the radiographic imaging features and the clinical presentation with the histopathological findings. Histologically, there were 21 granulomatous, 7 fibrous, 3 plasma cell, 3 lupus, 2 lymphocytic, and 1 case of acute mastitis. Radiographically, 16/25 (64%) patients with ultrasound studies showed irregular hypoechoic masses suspicious for malignancy. Clinically, 38% of patients had an associated systemic disease. © 2015 Wiley Periodicals, Inc.

  3. Clinical Features and Management of Acquired Resistance to PD-1 Axis Inhibitors in 26 Patients With Advanced Non-Small Cell Lung Cancer.

    PubMed

    Gettinger, Scott N; Wurtz, Anna; Goldberg, Sarah B; Rimm, David; Schalper, Kurt; Kaech, Susan; Kavathas, Paula; Chiang, Anne; Lilenbaum, Rogerio; Zelterman, Daniel; Politi, Katerina; Herbst, Roy S

    2018-06-01

    With expanding indications for programmed death 1 (PD-1) axis inhibitors in non-small cell lung cancer (NSCLC), acquired resistance (AR) to these therapies is increasingly being encountered. We sought to characterize clinical patterns of AR to PD-1 axis inhibitors in patients with advanced NSCLC, and evaluate subsequent outcome and management strategies for such patients. Patients with NSCLC who developed AR to PD-1 axis inhibitor therapy initiated between December 2009 and February 2016 at one institution were identified and examined by clinical and radiographic features. AR was defined as progressive disease after initial response by either Response Evaluation Criteria in Solid Tumors v1.1 or immune-related response criteria. Twenty-six patients with AR to PD-1 axis inhibitor therapy were identified and evaluated. Median time to AR was 313 days; the 2-year survival rate from AR was 70% (95% confidence interval: 0.53-0.92). Twenty patients (77%) experienced AR in lymph nodes (LNs), including 11 patients with LN-only progression. Twenty-three (88%) patients had recurrence limited to one (54%) or two (35%) sites of disease. Fourteen patients (54%) continued PD-1 axis inhibitor therapy beyond progression. Three patients were re-challenged with the same PD-1 axis inhibitor after holiday from and progression off therapy, 2 again responded. Fifteen patients (58%) received local therapy to site(s) of AR, 11 continued respective PD-1 axis inhibitor after local therapy. The 2-year survival rate from AR among these 15 patients was 92% (95% confidence interval: 0.77-1). Acquired resistance to PD-1 axis inhibitors is often limited to one or two sites when local therapy and continuation of PD-1 axis inhibitor therapy can result in prolonged benefit. LN metastases appear to be particularly susceptible sites to AR. When progression of disease following response occurs after holiday from PD-1 axis inhibitor, re-challenge can again lead to tumor regression. Copyright © 2018

  4. P-23 Highlights 6/10/12: Cygnus Dual Beam Radiographic Facility Refurbishment completed at U1A tunnel in Nevada NNSS meeting Level 2 milestone

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Deyoung, Anemarie; Smith, John R.

    2012-05-03

    A moratorium was placed on U.S. underground nuclear testing in 1992. In response, the Stockpile Stewardship Program was created to maintain readiness of the existing nuclear inventory through several efforts such as computer modeling, material analysis, and subcritical nuclear experiments (SCEs). As in the underground test era, the Nevada National Security Site (NNSS), formerly the Nevada Test Site, provides a safe and secure environment for SCEs by the nature of its isolated and secure facilities. A major tool for SCE diagnosis installed in the 05 drift laboratory is a high energy x-ray source used for time resolved imaging. This toolmore » consists of two identical sources (Cygnus 1 and Cygnus 2) and is called the Cygnus Dual Beam Radiographic Facility (Figs. 2-6). Each Cygnus machine has 5 major elements: Marx Generator, Pulse Forming Line (PFL), Coaxial Transmission Line (CTL), 3-cell Inductive Voltage Adder (IVA), and Rod Pinch Diode. Each machine is independently triggered and may be fired in separate tests (staggered mode), or in a single test where there is submicrosecond separation between the pulses (dual mode). Cygnus must operate as a single shot machine since on each pulse the diode electrodes are destroyed. The diode is vented to atmosphere, cleaned, and new electrodes are inserted for each shot. There is normally two shots per day on each machine. Since its installation in 2003, Cygnus has participated in: 4 Subcritical Experiments (Armando, Bacchus, Barolo A, and Barolo B), a 12 shot plutonium physics series (Thermos), and 2 plutonium step wedge calibration series (2005, 2011), resulting in well over 1000 shots. Currently the Facility is in preparation for 2 SCEs scheduled for this calendar year - Castor and Pollux. Cygnus has performed well during 8 years of operations at NNSS. Many improvements in operations and performance have been implemented during this time. Throughout its service at U1a, major maintenance and replacement of many hardware

  5. Effects of Different Viewing Conditions on Radiographic Interpretation.

    PubMed

    Moshfeghi, Mahkameh; Shahbazian, Majid; Sajadi, Soodabeh Sadat; Sajadi, Sepideh; Ansari, Hossein

    2015-11-01

    Optimum viewing conditions facilitate identification of radiographic details and decrease the need for retakes, patients' costs and radiation dose. This study sought to evaluate the effects of different viewing conditions on radiographic interpretation. This diagnostic study was performed by evaluating radiograph of a 7mm-thick aluminum block, in which 10 holes with 2mm diameters were randomly drilled with depths ranging from 0.05 mm to 0.50mm. The radiograph was viewed by four oral radiologists independently under four viewing conditions, including a white light viewing light box in a lit room, yellow light viewing light box in a lit room, white light viewing light box in a dark room and yellow light viewing light box in a dark room. Number of circular shadows observed on the film was recorded. The data were analyzed by two-way ANOVA. The mean number of detected circular shadows was 6.75, 7.5, 7.25 and 7.75 in white light viewing light box in a lit room, white light viewing light box in a dark room, yellow light viewing light box in a lit room and yellow light viewing light box in a dark room, respectively. Although the surrounding illumination had statistically significant effect on the radiographic details (P≤0.03), the light color of the viewing light box had no significant effect on visibility of the radiographic details. White and yellow light of the viewing light box had no significant effect on visibility of the radiographic details but more information was obtained in a dark room.

  6. Single-Axis Accelerometer

    NASA Technical Reports Server (NTRS)

    Tucker, Dennis Stephen (Inventor); Capo-Lugo, Pedro A. (Inventor)

    2016-01-01

    A single-axis accelerometer includes a housing defining a sleeve. An object/mass is disposed in the sleeve for sliding movement therein in a direction aligned with the sleeve's longitudinal axis. A first piezoelectric strip, attached to a first side of the object and to the housing, is longitudinally aligned with the sleeve's longitudinal axis. The first piezoelectric strip includes a first strip of a piezoelectric material with carbon nanotubes substantially aligned along a length thereof. A second piezoelectric strip, attached to a second side of the object and to the housing, is longitudinally aligned with the sleeve's longitudinal axis. The second piezoelectric strip includes a second strip of the piezoelectric material with carbon nanotubes substantially aligned along a length thereof. A voltage sensor is electrically coupled to at least one of the first and second piezoelectric strips.

  7. 21 CFR 892.1950 - Radiographic anthropomorphic phantom.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... purposes to simulate a human body for positioning radiographic equipment. (b) Classification. Class I... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Radiographic anthropomorphic phantom. 892.1950 Section 892.1950 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES...

  8. 21 CFR 892.1950 - Radiographic anthropomorphic phantom.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... purposes to simulate a human body for positioning radiographic equipment. (b) Classification. Class I... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Radiographic anthropomorphic phantom. 892.1950 Section 892.1950 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES...

  9. 21 CFR 892.1950 - Radiographic anthropomorphic phantom.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... purposes to simulate a human body for positioning radiographic equipment. (b) Classification. Class I... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Radiographic anthropomorphic phantom. 892.1950 Section 892.1950 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES...

  10. 21 CFR 892.1950 - Radiographic anthropomorphic phantom.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... purposes to simulate a human body for positioning radiographic equipment. (b) Classification. Class I... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radiographic anthropomorphic phantom. 892.1950 Section 892.1950 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES...

  11. 21 CFR 892.1950 - Radiographic anthropomorphic phantom.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... purposes to simulate a human body for positioning radiographic equipment. (b) Classification. Class I... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Radiographic anthropomorphic phantom. 892.1950 Section 892.1950 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES...

  12. 21 CFR 892.1960 - Radiographic intensifying screen.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radiographic intensifying screen. 892.1960 Section 892.1960 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1960 Radiographic intensifying screen...

  13. 21 CFR 892.1920 - Radiographic head holder.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radiographic head holder. 892.1920 Section 892.1920 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1920 Radiographic head holder. (a...

  14. The Joint Structure of DSM–IV Axis I and Axis II Disorders

    PubMed Central

    Røysamb, Espen; Tambs, Kristian; Ørstavik, Ragnhild E.; Torgersen, Svenn; Kendler, Kenneth S.; Neale, Michael C.; Aggen, Steven H.; Reichborn-Kjennerud, Ted

    2011-01-01

    The Diagnostic and Statistical Manual (4th ed. [DSM–IV]; American Psychiatric Association, 1994) distinction between clinical disorders on Axis I and personality disorders on Axis II has become increasingly controversial. Although substantial comorbidity between axes has been demonstrated, the structure of the liability factors underlying these two groups of disorders is poorly understood. The aim of this study was to determine the latent factor structure of a broad set of common Axis I disorders and all Axis II personality disorders and thereby to identify clusters of disorders and account for comorbidity within and between axes. Data were collected in Norway, through a population-based interview study (N = 2,794 young adult twins). Axis I and Axis II disorders were assessed with the Composite International Diagnostic Interview (CIDI) and the Structured Interview for DSM–IV Personality (SIDP–IV), respectively. Exploratory and confirmatory factor analyses were used to investigate the underlying structure of 25 disorders. A four-factor model fit the data well, suggesting a distinction between clinical and personality disorders as well as a distinction between broad groups of internalizing and externalizing disorders. The location of some disorders was not consistent with the DSM–IV classification; antisocial personality disorder belonged primarily to the Axis I externalizing spectrum, dysthymia appeared as a personality disorder, and borderline personality disorder appeared in an interspectral position. The findings have implications for a meta-structure for the DSM. PMID:21319931

  15. Automatic image hanging protocol for chest radiographs in PACS.

    PubMed

    Luo, Hui; Hao, Wei; Foos, David H; Cornelius, Craig W

    2006-04-01

    Chest radiography is one of the most widely used techniques in diagnostic imaging. It comprises at least one-third of all diagnostic radiographic procedures in hospitals. However, in the picture archive and communication system, images are often stored with the projection and orientation unknown or mislabeled, which causes inefficiency for radiologists' interpretation. To address this problem, an automatic hanging protocol for chest radiographs is presented. The method targets the most effective region in a chest radiograph, and extracts a set of size-, rotation-, and translation-invariant features from it. Then, a well-trained classifier is used to recognize the projection. The orientation of the radiograph is later identified by locating the neck, heart, and abdomen positions in the radiographs. Initial experiments are performed on the radiographs collected from daily routine chest exams in hospitals and show promising results. Using the presented protocol, 98.2% of all cases could be hung correctly on projection view (without protocol, 62%), and 96.1% had correct orientation (without protocol, 75%). A workflow study on the protocol also demonstrates a significant improvement in efficiency for image display.

  16. A radiographic scanning technique for cores

    USGS Publications Warehouse

    Hill, G.W.; Dorsey, M.E.; Woods, J.C.; Miller, R.J.

    1979-01-01

    A radiographic scanning technique (RST) can produce single continuous radiographs of cores or core sections up to 1.5 m long and up to 30 cm wide. Changing a portable industrial X-ray unit from the normal still-shot mode to a scanning mode requires simple, inexpensive, easily constructed, and highly durable equipment. Additional components include a conveyor system, antiscatter cylinder-diaphragm, adjustable sample platform, developing tanks, and a contact printer. Complete cores, half cores, sample slabs or peels may be scanned. Converting the X-ray unit from one mode to another is easy and can be accomplished without the use of special tools. RST provides the investigator with a convenient, continuous, high quality radiograph, saves time and money, and decreases the number of times cores have to be handled. ?? 1979.

  17. Reestablishment of radiographic kidney size in Miniature Schnauzer dogs

    PubMed Central

    SOHN, Jungmin; YUN, Sookyung; LEE, Jeosoon; CHANG, Dongwoo; CHOI, Mincheol; YOON, Junghee

    2016-01-01

    Kidney size may be altered in renal diseases, and the detection of kidney size alteration has diagnostic and prognostic values. We hypothesized that radiographic kidney size, the kidney length to the second lumbar vertebra (L2) length ratio, in normal Miniature Schnauzer dogs may be overestimated due to their shorter vertebral length. This study was conducted to evaluate radiographic and ultrasonographic kidney size and L2 length in clinically normal Miniature Schnauzers and other dog breeds to evaluate the effect of vertebral length on radiographic kidney size and to reestablish radiographic kidney size in normal Miniature Schnauzers. Abdominal radiographs and ultrasonograms from 49 Miniature Schnauzers and 54 other breeds without clinical evidence of renal disease and lumbar vertebral abnormality were retrospectively evaluated. Radiographic kidney size, in the Miniature Schnauzer (3.31 ± 0.26) was significantly larger than that in other breeds (2.94 ± 0.27). Relative L2 length, the L2 length to width ratio, in the Miniature Schnauzer (1.11 ± 0.06) was significantly shorter than that in other breeds (1.21 ± 0.09). However, ultrasonographic kidney sizes, kidney length to aorta diameter ratios, were within or very close to normal range both in the Miniature Schnauzer (6.75 ± 0.67) and other breeds (7.16 ± 1.01). Thus, Miniature Schnauzer dogs have breed-specific short vertebrae and consequently a larger radiographic kidney size, which was greater than standard reference in normal adult dogs. Care should be taken when evaluating radiographic kidney size in Miniature Schnauzers to prevent falsely diagnosed renomegaly. PMID:27594274

  18. Reestablishment of radiographic kidney size in Miniature Schnauzer dogs.

    PubMed

    Sohn, Jungmin; Yun, Sookyung; Lee, Jeosoon; Chang, Dongwoo; Choi, Mincheol; Yoon, Junghee

    2017-01-10

    Kidney size may be altered in renal diseases, and the detection of kidney size alteration has diagnostic and prognostic values. We hypothesized that radiographic kidney size, the kidney length to the second lumbar vertebra (L2) length ratio, in normal Miniature Schnauzer dogs may be overestimated due to their shorter vertebral length. This study was conducted to evaluate radiographic and ultrasonographic kidney size and L2 length in clinically normal Miniature Schnauzers and other dog breeds to evaluate the effect of vertebral length on radiographic kidney size and to reestablish radiographic kidney size in normal Miniature Schnauzers. Abdominal radiographs and ultrasonograms from 49 Miniature Schnauzers and 54 other breeds without clinical evidence of renal disease and lumbar vertebral abnormality were retrospectively evaluated. Radiographic kidney size, in the Miniature Schnauzer (3.31 ± 0.26) was significantly larger than that in other breeds (2.94 ± 0.27). Relative L2 length, the L2 length to width ratio, in the Miniature Schnauzer (1.11 ± 0.06) was significantly shorter than that in other breeds (1.21 ± 0.09). However, ultrasonographic kidney sizes, kidney length to aorta diameter ratios, were within or very close to normal range both in the Miniature Schnauzer (6.75 ± 0.67) and other breeds (7.16 ± 1.01). Thus, Miniature Schnauzer dogs have breed-specific short vertebrae and consequently a larger radiographic kidney size, which was greater than standard reference in normal adult dogs. Care should be taken when evaluating radiographic kidney size in Miniature Schnauzers to prevent falsely diagnosed renomegaly.

  19. Radiographic Study of Haematogenous Septic Arthritis in Dairy Calves.

    PubMed

    Constant, Caroline; Masseau, Isabelle; Babkine, Marie; Nichols, Sylvain; Francoz, David; Fecteau, Gilles; Marchionatti, Emma; Larde, Helene; Desrochers, Andre

    2018-06-16

     (1) To develop an evaluation grid to provide a systematic interpretation of calves' articular radiographs, (2) to describe radiographic lesions of septic arthritis in dairy calves less than 6 months of age, (3) to investigate potential associations between demographic data or synovial bacteriological culture results and radiographic lesions (4) to determine whether an association is present between radiographic lesions, their severity and the long-term outcome.  Medical records of 54 calves less than 180 days old treated for septic arthritis between 2009 and 2014 with radiographic images performed in the first 2 days after admission were reviewed.  Most common radiographic findings were increased articular joint space height ( n  = 49), irregularity of the articular surfaces ( n  = 24) and subchondral bone lysis ( n  = 24). The number of lesions observed and their severity were associated with older calves ( p  = 0.02), increased time between onset of clinical signs and admission ( p  = 0.0001) and the culture of Trueperella pyogenes within the joint ( p  = 0.02). The radiographic lesions associated with negative long-term prognosis were reduction in the joint space height ( p  = 0.01) and subchondral bone lysis on weight-bearing surfaces ( p  = 0.02).  An evaluation grid designed for veterinarians can facilitate systematic reading of articular radiographs and can be used for dairy calves with a presumptive diagnosis of septic arthritis. This diagnostic tool may aid in establishing a prognosis and decision-making process in terms of treatment. Schattauer GmbH Stuttgart.

  20. Effects of Different Viewing Conditions on Radiographic Interpretation

    PubMed Central

    Moshfeghi, Mahkameh; Shahbazian, Majid; Sajadi, Soodabeh Sadat; Sajadi, Sepideh; Ansari, Hossein

    2015-01-01

    Objectives: Optimum viewing conditions facilitate identification of radiographic details and decrease the need for retakes, patients’ costs and radiation dose. This study sought to evaluate the effects of different viewing conditions on radiographic interpretation. Materials and Methods: This diagnostic study was performed by evaluating radiograph of a 7mm-thick aluminum block, in which 10 holes with 2mm diameters were randomly drilled with depths ranging from 0.05 mm to 0.50mm. The radiograph was viewed by four oral radiologists independently under four viewing conditions, including a white light viewing light box in a lit room, yellow light viewing light box in a lit room, white light viewing light box in a dark room and yellow light viewing light box in a dark room. Number of circular shadows observed on the film was recorded. The data were analyzed by two-way ANOVA. Results: The mean number of detected circular shadows was 6.75, 7.5, 7.25 and 7.75 in white light viewing light box in a lit room, white light viewing light box in a dark room, yellow light viewing light box in a lit room and yellow light viewing light box in a dark room, respectively. Although the surrounding illumination had statistically significant effect on the radiographic details (P≤0.03), the light color of the viewing light box had no significant effect on visibility of the radiographic details. Conclusion: White and yellow light of the viewing light box had no significant effect on visibility of the radiographic details but more information was obtained in a dark room. PMID:27507997

  1. Coupling effect and control strategies of the maglev dual-stage inertially stabilization system based on frequency-domain analysis.

    PubMed

    Lin, Zhuchong; Liu, Kun; Zhang, Li; Zeng, Delin

    2016-09-01

    Maglev dual-stage inertially stabilization (MDIS) system is a newly proposed system which combines a conventional two-axis gimbal assembly and a 5-DOF (degree of freedom) magnetic bearing with vernier tilting capacity to perform dual-stage stabilization for the LOS of the suspended optical instrument. Compared with traditional dual-stage system, maglev dual-stage system exhibits different characteristics due to the negative position stiffness of the magnetic forces, which introduces additional coupling in the dual stage control system. In this paper, the coupling effect on the system performance is addressed based on frequency-domain analysis, including disturbance rejection, fine stage saturation and coarse stage structural resonance suppression. The difference between various control strategies is also discussed, including pile-up(PU), stabilize-follow (SF) and stabilize-compensate (SC). A number of principles for the design of a maglev dual stage system are proposed. A general process is also suggested, which leads to a cost-effective design striking a balance between high performance and complexity. At last, a simulation example is presented to illustrate the arguments in the paper. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

  2. Reproducibility of sagittal radiographic parameters in adolescent idiopathic scoliosis-a guide to reference values using serial imaging.

    PubMed

    Hey, Hwee Weng Dennis; Wong, Gordon Chengyuan; Chan, Chloe Xiaoyun; Lau, Leok-Lim; Kumar, Naresh; Thambiah, Joseph Shantakumar; Ruiz, John Nathaniel; Liu, Ka-Po Gabriel; Wong, Hee-Kit

    2017-06-01

    Knowledge of sagittal radiographic parameters in adolescent idiopathic scoliosis (AIS) patients has not yet caught up with our understanding of their roles in patients with adult spinal deformity. It is likely that more emphasis will be placed in restoring sagittal parameters for AIS patients in the future. Therefore, we need to understand how these parameters may vary in AIS to facilitate management plans. This study aimed to determine the reproducibility of sagittal spinal parameters on lateral film radiographs in patients with AIS. This was a retrospective, comparative study conducted in a tertiary health-care institution from January 2013 to February 2016 (3-year period). All AIS patients who underwent deformity correction surgery from January 2013 to February 2016 and had two preoperative serial lateral radiographs taken within the time period of a month were included in the study. Radiographic sagittal spinal parameters including sagittal vertical axis (SVA), cervical lordosis (CL), thoracic kyphosis (TK), thoracolumbar alignment (TL), lumbar lordosis (LL); standard spinopelvic measurements such as pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS); as well as end and apical vertebrae of cervical, thoracic, and lumbar curves were the outcome measures. All patient data were pooled from electronic medical records, and X-ray images were retrieved from Centricity Enterprise Web. Averaged X-ray measurements by two independent assessors were analyzed by comparing two radiographs of the same patients performed within a 1-month time period. Chi-squared and Wilcoxon signed-rank tests were used for categorical and continuous variables. The study cohort comprised 138 patients, 28 men and 110 women, with a mean age of 15 years (range 11-20). Between the two lateral X-rays, there was a mean difference of 0.79 cm in SVA (p<.001), 0.70° in LL (p=.033), and 0.73° in PT (p=.010). In the combined Lenke 1 and 2 subgroup, there was a similar 0.77 cm (p=.002), 0.79

  3. Small lung cancers: improved detection by use of bone suppression imaging--comparison with dual-energy subtraction chest radiography.

    PubMed

    Li, Feng; Engelmann, Roger; Pesce, Lorenzo L; Doi, Kunio; Metz, Charles E; Macmahon, Heber

    2011-12-01

    To determine whether use of bone suppression (BS) imaging, used together with a standard radiograph, could improve radiologists' performance for detection of small lung cancers compared with use of standard chest radiographs alone and whether BS imaging would provide accuracy equivalent to that of dual-energy subtraction (DES) radiography. Institutional review board approval was obtained. The requirement for informed consent was waived. The study was HIPAA compliant. Standard and DES chest radiographs of 50 patients with 55 confirmed primary nodular cancers (mean diameter, 20 mm) as well as 30 patients without cancers were included in the observer study. A new BS imaging processing system that can suppress the conspicuity of bones was applied to the standard radiographs to create corresponding BS images. Ten observers, including six experienced radiologists and four radiology residents, indicated their confidence levels regarding the presence or absence of a lung cancer for each lung, first by using a standard image, then a BS image, and finally DES soft-tissue and bone images. Receiver operating characteristic (ROC) analysis was used to evaluate observer performance. The average area under the ROC curve (AUC) for all observers was significantly improved from 0.807 to 0.867 with BS imaging and to 0.916 with DES (both P < .001). The average AUC for the six experienced radiologists was significantly improved from 0.846 with standard images to 0.894 with BS images (P < .001) and from 0.894 to 0.945 with DES images (P = .001). Use of BS imaging together with a standard radiograph can improve radiologists' accuracy for detection of small lung cancers on chest radiographs. Further improvements can be achieved by use of DES radiography but with the requirement for special equipment and a potential small increase in radiation dose. © RSNA, 2011.

  4. Two-Photon Absorption Spectroscopy of Rubidium with a Dual-Comb Tequnique

    NASA Astrophysics Data System (ADS)

    Nishiyama, Akiko; Yoshida, Satoru; Hariki, Takuya; Nakajima, Yoshiaki; Minoshima, Kaoru

    2017-06-01

    Dual-comb spectroscopies have great potential for high-resolution molecular and atomic spectroscopies, thanks to the broadband comb spectrum consisting of dense narrow modes. In this study, we apply the dual-comb system to Doppler-free two-photon absorption spectroscopy. The outputs of two frequency combs excite several two-photon transitions of rubidium, and we obtained broadband Doppler-free spectra from dual-comb fluorescence signals. The fluorescence detection scheme circumvents the sensitivity limit which is effectively determined by the dynamic range of photodetectors in absorption-based dual-comb spectroscopies. Our system realized high-sensitive, Doppler-free high-resolution and broadband atomic spectroscopy. A part of observed spectra of 5S_{1/2} - 5D_{5/2} transition is shown in the figure. The hyperfine structures of the F" = 1 - F' = 3,2,1 transitions are fully-resolved and the spectral widths are approximately 5 MHz. The absolute frequency axis is precisely calibrated from comb mode frequencies which were stabilized to a GPS-disciplined clock. This work was supported by JST through the ERATO MINOSHIMA Intelligent Optical Synthesizer Project and Grant-in-Aid for JSPS Fellows (16J02345). A. Nishiyama, S. Yoshida, Y. Nakajima, H. Sasada, K. Nakagawa, A. Onae, K. and Minoshima, Opt. Express 24, 25894 (2016). A. Hipke, S. A. Meek, T. Ideguchi, T.W. Hänsch, and N. Picqué, Phys. Rev. A 90, 011805(R) (2014).

  5. Dual-beam, second-derivative tunable diode-laser infrared spectroscopy applied to trace-gas measurement

    NASA Astrophysics Data System (ADS)

    Tallant, D. R.; Jungst, R. G.

    1981-04-01

    A dual base diode laser spectrometer was constructed using off axis reflective optics. The spectrometer was amplitude modulated for direct absorption measurements or frequency modulated to obtain derivative spectra. The spectrometer had: high throughput; was easy to operate and align; provided good dual beam compensation; and had no evidence of the interference effects that were observed in diode laser spectrometers using refractive optics. Unpurged, using second derivative techniques, the instrument measured 108 parts per million CO (10/cm absorption cell, atmospheric pressure broadened) with good signal/noise. With the replacement of marginal instrumental components, the signal/noise was substantially increased. This instrument was developed to monitor the evolution of decomposition gases in sealed containers of small volume at atmospheric pressure.

  6. Endodontic radiography: who is reading the digital radiograph?

    PubMed

    Tewary, Shalini; Luzzo, Joseph; Hartwell, Gary

    2011-07-01

    Digital radiographic imaging systems have undergone tremendous improvements since their introduction. Advantages of digital radiographs over conventional films include lower radiation doses compared with conventional films, instantaneous images, archiving and sharing images easily, and manipulation of several radiographic properties that might help in diagnosis. A total of 6 observers including 2 endodontic residents, 3 endodontists, and 1 oral radiologist evaluated 150 molar digital periapical radiographs to determine which of the following conditions existed: normal periapical tissue, widened periodontal ligament, or presence of periapical radiolucency. The evaluators had full control over the radiograph's parameters of the Planmeca Dimaxis software program. All images were viewed on the same computer monitor with ideal vie-wing conditions. The same 6 observers evaluated the same 150 digital images 3 months later. The data were analyzed to determine how well the evaluators agreed with each other (interobserver agreement) for 2 rounds of observations and with themselves (intraobserver agreement). Fleiss kappa statistical analysis was used to measure the level of agreement among multiple raters. The overall Fleiss kappa value for interobserver agreement for the first round of interpretation was 0.34 (P < .001). The overall Fleiss kappa value for interobserver agreement for the second round of interpretation was 0.35 (P < .001). This resulted in fair (0.2-0.4) agreement among the 6 raters at both observation periods. A weighted kappa analysis was used to determine intraobserver agreement, which showed on average a moderate agreement. The results indicate that the interpretation of a dental radiograph is subjective, irrespective of whether conventional or digital radiographs are used. The factors that appeared to have the most impact were the years of experience of the examiner and familiarity of the operator with a given digital system. Copyright © 2011 American

  7. Radiographic appearance of bronchoalveolar carcinoma in nine cats.

    PubMed

    Ballegeer, Elizabeth A; Forrest, Lisa J; Stepien, Rebecca L

    2002-01-01

    Thoracic radiographs of nine cats with confirmed bronchoalveolar carcinoma (BAC) were reviewed retrospectively. Radiographic appearance of BAC was divided into three categories: mixed bronchoalveolar pattern, ill-defined alveolar mass, or mass with cavitation. In addition to these radiographic signs, all nine cats had evidence of some form of bronchial disease. Cavitary lesions were the most common finding (n = 5). In addition, three cats in this category had diffuse bronchointerstitial opacity and one cat had focal peribronchial cuffing. Five cats had either a mixed bronchoalveolar pattern with bronchiectasis (n = 3) or an ill-defined alveolar mass with peribronchial cuffing (n = 2). One cat had both a mixed bronchoalveolar pattern and a cavitary mass. Each of these nine cats had some form of bronchial disease (bronchointerstitial pattern, peribronchial cuffing, or bronchiectasis), which aids in the radiographic diagnosis of bronchoalveolar carcinoma and may represent airway metastasis.

  8. Radiographic follow-up of community-acquired pneumonia in children.

    PubMed

    Surén, Pål; Try, Kirsti; Eriksson, Jan; Khoshnewiszadeh, Behzad; Wathne, Karl-Olaf

    2008-01-01

    To evaluate the value of radiographic follow-up of community-acquired pneumonia in children who are previously healthy. Patient records for the years 2003 and 2004 at the Ullevål University Hospital in Oslo were reviewed, and a total of 245 children were selected for the study. Radiographs were evaluated by two paediatric radiologists independently. One hundred and thirty-three patients had control radiographs, of which 106 were normal and 27 were abnormal. Only three of 27 patients with abnormal findings had further clinical problems that could be related to the pneumonia. Two of 106 with normal findings had further clinical problems, despite the normal control radiograph. Of the 112 without radiographic follow-up, 10 had subsequent clinical problems, but most occurred within the first 4 weeks after discharge, before controls would have been scheduled. There were five patients who may have benefited from controls. One relapse could theoretically have been prevented. Four patients were cases for whom the pneumonias were the first manifestations of chronic lung disease. Such patients may have some benefit from control radiographs, but only in terms of detecting the chronic disease at an earlier stage, not in altering the clinical course. Such modest benefits must be weighed against the consequences of providing follow-up to a large number of healthy children, and making lots of abnormal findings with no clinical significance. Control radiographs are not very valuable in children who are otherwise healthy.

  9. Hybrid shallow on-axis and deep off-axis hydrothermal circulation at fast-spreading ridges.

    PubMed

    Hasenclever, Jörg; Theissen-Krah, Sonja; Rüpke, Lars H; Morgan, Jason P; Iyer, Karthik; Petersen, Sven; Devey, Colin W

    2014-04-24

    Hydrothermal flow at oceanic spreading centres accounts for about ten per cent of all heat flux in the oceans and controls the thermal structure of young oceanic plates. It also influences ocean and crustal chemistry, provides a basis for chemosynthetic ecosystems, and has formed massive sulphide ore deposits throughout Earth's history. Despite this, how and under what conditions heat is extracted, in particular from the lower crust, remains largely unclear. Here we present high-resolution, whole-crust, two- and three-dimensional simulations of hydrothermal flow beneath fast-spreading ridges that predict the existence of two interacting flow components, controlled by different physical mechanisms, that merge above the melt lens to feed ridge-centred vent sites. Shallow on-axis flow structures develop owing to the thermodynamic properties of water, whereas deeper off-axis flow is strongly shaped by crustal permeability, particularly the brittle-ductile transition. About 60 per cent of the discharging fluid mass is replenished on-axis by warm (up to 300 degrees Celsius) recharge flow surrounding the hot thermal plumes, and the remaining 40 per cent or so occurs as colder and broader recharge up to several kilometres away from the axis that feeds hot (500-700 degrees Celsius) deep-rooted off-axis flow towards the ridge. Despite its lower contribution to the total mass flux, this deep off-axis flow carries about 70 per cent of the thermal energy released at the ridge axis. This combination of two flow components explains the seismically determined thermal structure of the crust and reconciles previously incompatible models favouring either shallower on-axis or deeper off-axis hydrothermal circulation.

  10. 42 CFR 37.50 - Interpreting and classifying chest radiographs-film.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Interpreting and classifying chest radiographs-film. 37.50 Section 37.50 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Radiographs § 37.50 Interpreting and classifying chest radiographs—film. (a) Chest radiographs must be...

  11. 10 CFR 34.41 - Conducting industrial radiographic operations.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 false Conducting industrial radiographic operations. 34.41 Section 34.41 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Radiation Safety Requirements § 34.41...

  12. 10 CFR 34.41 - Conducting industrial radiographic operations.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Conducting industrial radiographic operations. 34.41 Section 34.41 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Radiation Safety Requirements § 34.41...

  13. 10 CFR 34.41 - Conducting industrial radiographic operations.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 1 2012-01-01 2012-01-01 false Conducting industrial radiographic operations. 34.41 Section 34.41 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Radiation Safety Requirements § 34.41...

  14. 10 CFR 34.41 - Conducting industrial radiographic operations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Conducting industrial radiographic operations. 34.41 Section 34.41 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Radiation Safety Requirements § 34.41...

  15. 10 CFR 34.41 - Conducting industrial radiographic operations.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 1 2013-01-01 2013-01-01 false Conducting industrial radiographic operations. 34.41 Section 34.41 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Radiation Safety Requirements § 34.41...

  16. Influence of Radiographic Positioning on Canine Sacroiliac and Lumbosacral Angle Measurements.

    PubMed

    Jones, Susan; Savage, Mason; Naughton, Brian; Singh, Susheela; Robertson, Ian; Roe, Simon C; Marcellin-Little, Denis J; Mathews, Kyle G

    2018-01-01

     To evaluate the influence of radiographic malpositioning on canine sacroiliac and lumbosacral inclination angles.  Using canine cadavers, lateral pelvic radiographs were acquired with the radiographic beam in a neutral position and then rotated 5, 10 and 15° to mimic rotational malpositioning. The focal point of the beam was then focused over the abdomen and again over mid-diaphysis of the femur to mimic an abdominal or femoral radiographic study.  Five degrees of rotational malpositioning did not influence measurements of sacroiliac or lumbosacral inclination, but malpositioning by more than 5° led to a significant decrease in both sacroiliac and lumbosacral angles. Moving the focal point to the femur significantly decreased the measured lumbosacral angle. Abdominally centred radiographs had no effect on lumbosacral and sacroiliac angle measurements.  When evaluating canine lumbosacral and sacroiliac angles radiographically, pelvic rotation of more than 5° should be avoided as should the use of lateral radiographs centred over the femur. Schattauer GmbH Stuttgart.

  17. LAFD: TA-15 DARHT Firefighter Facility Familiarization Tour, OJT 53044, Revision 0.2

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Rutherford, Victor Stephen; Priestley, Terry B.; Maestas, Marvin Manuel

    The Los Alamos National Laboratory (LANL or the Lab) will conduct familiarization tours for the Los Alamos County Fire Department (LAFD) at the Dual-Axis Radiographic Hydrodynamic Test (DARHT) Facility, TA-15-0312. The purpose of these tours is to orient LAFD firefighters to the DARHT facility layout and hazards. This document provides information and figures to supplement the familiarization tours. The document will be distributed to the trainees at the time of the familiarization tour. A checklist (Attachment A) has also been developed to ensure that all required information is consistently presented to LAFD personnel during the familiarization tours.

  18. Interactive radiographic image retrieval system.

    PubMed

    Kundu, Malay Kumar; Chowdhury, Manish; Das, Sudeb

    2017-02-01

    Content based medical image retrieval (CBMIR) systems enable fast diagnosis through quantitative assessment of the visual information and is an active research topic over the past few decades. Most of the state-of-the-art CBMIR systems suffer from various problems: computationally expensive due to the usage of high dimensional feature vectors and complex classifier/clustering schemes. Inability to properly handle the "semantic gap" and the high intra-class versus inter-class variability problem of the medical image database (like radiographic image database). This yields an exigent demand for developing highly effective and computationally efficient retrieval system. We propose a novel interactive two-stage CBMIR system for diverse collection of medical radiographic images. Initially, Pulse Coupled Neural Network based shape features are used to find out the most probable (similar) image classes using a novel "similarity positional score" mechanism. This is followed by retrieval using Non-subsampled Contourlet Transform based texture features considering only the images of the pre-identified classes. Maximal information compression index is used for unsupervised feature selection to achieve better results. To reduce the semantic gap problem, the proposed system uses a novel fuzzy index based relevance feedback mechanism by incorporating subjectivity of human perception in an analytic manner. Extensive experiments were carried out to evaluate the effectiveness of the proposed CBMIR system on a subset of Image Retrieval in Medical Applications (IRMA)-2009 database consisting of 10,902 labeled radiographic images of 57 different modalities. We obtained overall average precision of around 98% after only 2-3 iterations of relevance feedback mechanism. We assessed the results by comparisons with some of the state-of-the-art CBMIR systems for radiographic images. Unlike most of the existing CBMIR systems, in the proposed two-stage hierarchical framework, main importance

  19. Purely hopping conduction in c-axis oriented LiNbO3 thin films

    NASA Astrophysics Data System (ADS)

    Shandilya, Swati; Tomar, Monika; Sreenivas, K.; Gupta, Vinay

    2009-05-01

    Dielectric constant and ac conductivity of highly c-axis oriented LiNbO3 thin film grown by pulsed laser deposition were studied in a metal-insulator-metal configuration over a wide temperature (200 to 450 K) and frequency (100 Hz to 1 MHz) range. The preferred oriented Al (1%) doped ZnO film with electrical conductivity 1.1×103 Ω-1 cm-1 was deposited for dual purpose: (1) to serve as nucleating center for LiNbO3 crystallites along preferred c-axis growth direction, and (2) to act as a suitable bottom electrode for electrical studies. The room temperature dc conductivity (σdc) of LiNbO3 film was about 5.34×10-10 Ω-1 cm-1 with activation energy ˜0.3 eV, indicating extrinsic conduction. The ac conductivity σac was found to be much higher in comparison to σdc in the low temperature region (<300 K) and exhibits a power law behavior due to the hopping of charge carriers. In higher temperature region (>300 K), σac shows a weak frequency dependence, whereas dielectric constant exhibits a strong frequency dispersion. The dielectric dispersion data has been discussed in the light of theoretical models based on Debye type mixed conduction and purely hopping conduction. The dominant conduction in c-axis oriented LiNbO3 thin film is attributed to the purely hopping where both σdc and σac arise due to same mechanism.

  20. Proton Radiography Imager:Generates Synthetic Proton Radiographs

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wilks, Scott C.; Black, Mason R.

    ProRad is a computer program that is used to generate synthetic images of proton (or other charged particles) radiographs. The proton radiographs arc images that arc obtained by sending energetic protons (or electrons or positrons, for example) through 11 plasma where electric and/or magnetic fields alter the particles trajectory, Dnd the variations me imaged on RC film, image plate, or equivalent

  1. A new method for designing dual foil electron beam forming systems. II. Feasibility of practical implementation of the method

    NASA Astrophysics Data System (ADS)

    Adrich, Przemysław

    2016-05-01

    In Part I of this work a new method for designing dual foil electron beam forming systems was introduced. In this method, an optimal configuration of the dual foil system is found by means of a systematic, automatized scan of system performance in function of its parameters. At each point of the scan, Monte Carlo method is used to calculate the off-axis dose profile in water taking into account detailed and complete geometry of the system. The new method, while being computationally intensive, minimizes the involvement of the designer. In this Part II paper, feasibility of practical implementation of the new method is demonstrated. For this, a prototype software tools were developed and applied to solve a real life design problem. It is demonstrated that system optimization can be completed within few hours time using rather moderate computing resources. It is also demonstrated that, perhaps for the first time, the designer can gain deep insight into system behavior, such that the construction can be simultaneously optimized in respect to a number of functional characteristics besides the flatness of the off-axis dose profile. In the presented example, the system is optimized in respect to both, flatness of the off-axis dose profile and the beam transmission. A number of practical issues related to application of the new method as well as its possible extensions are discussed.

  2. Pes planus: radiographic changes with foot orthoses and shoes.

    PubMed

    Penneau, K; Lutter, L D; Winter, R D

    1982-03-01

    Radiographic evaluation of 10 children with bilateral pes planus was performed. Radiographs taken barefoot, with a Thomas heel, with an over-the-counter insert, with two specially molded plastic foot orthoses were used. No significant change was seen after the donning of these appliances in their comparison to barefoot evaluation. The conclusion is that there was not a significant change radiographically of these feet by the utilization of any of the appliances.

  3. Digital radiographic imaging: is the dental practice ready?

    PubMed

    Parks, Edwin T

    2008-04-01

    Digital radiographic imaging is slowly, but surely, replacing film-based imaging. It has many advantages over traditional imaging, but the technology also has some drawbacks. The author presents an overview of the types of digital image receptors available, image enhancement software and the range of costs for the new technology. PRACTICE IMPLICATIONS. The expenses associated with converting to digital radiographic imaging are considerable. The purpose of this article is to provide the clinician with an overview of digital radiographic imaging technology so that he or she can be an informed consumer when evaluating the numerous digital systems in the marketplace.

  4. Investigation of an electronic image enhancer for radiographs

    NASA Technical Reports Server (NTRS)

    Vary, A.

    1972-01-01

    Radiographs of nuclear and aerospace components were studied with a closed-circuit television system to determine the advantages of electronic enhancement in radiographic nondestructive evaluation. The radiographic images were examined on a television monitor under various degrees of magnification and enhancement. The enhancement was accomplished by generating a video signal whose amplitude is proportional to the rate of change of density. Points, lines, edges, and other density variations that are faintly registered in the original image are rendered in sharp relief. Examples of the applications of this mode of enhancement are discussed together with the system's dynamic response and resolution.

  5. Investigation of an electronic image enhancer for radiographs.

    NASA Technical Reports Server (NTRS)

    Vary, A.

    1972-01-01

    Radiographs of nuclear and aerospace components were studied with a closed-circuit television system to determine the advantages of electronic enhancement in radiographic nondestructive evaluation. The radiographic images were examined on a television monitor under various degrees of magnification and enhancement. The enhancement was accomplished by generating a video signal whose amplitude is proportional to the rate of change of density. Points, lines, edges, and other density variations that are faintly registered in the original image are rendered in sharp relief. Examples of the applications of this mode of enhancement are discussed together with the system's dynamic response and resolution.

  6. Ontario dentists: 3. Radiographs prescribed in general practice.

    PubMed

    Swan, E S; Lewis, D W

    1993-01-01

    In February 1991, a mail survey was used to poll a sample consisting of about 10 per cent of Ontario's general dentists. The data obtained provided information about the radiographs prescribed by dentists for five different patient types, which were described to the respondents. The per cent agreement between the radiographic procedures prescribed by Ontario dentists and the ADA-approved Center for Devices and Radiological Health (CDRH) guidelines ranged from three per cent to 79 per cent, depending on patient type and disease risk. For each patient and risk type, there was considerable variation in the radiographs prescribed.

  7. Upright vs. Supine Radiographs of Clavicle Fractures: Does Positioning Matter?

    PubMed Central

    Backus, Jonathon D; Merriman, David J; McAndrew, Christopher M; Gardner, Michael J; Ricci, William M

    2014-01-01

    Objectives To determine if clavicle fracture displacement and shortening are different between upright and supine radiographic examinations. Design Combined retrospective and prospective comparative study. Setting Level I Trauma Center Patients Forty-six patients (mean age 49 years, range 24–89 years) with an acute clavicle fracture were evaluated. Intervention Standardized clavicle radiographs were obtained in both supine and upright positions for each patient. Displacement and shortening were measured and compared between the two positions. Main Outcomes Measurements One resident and three traumatologists classified the fractures and measured displacement and shortening. Data was aggregated and compared to ensure reliability with a two-way mixed intraclass correlation (ICC). Results Fracture displacement was significantly greater when measured from upright radiographs (15.9±8.9mm) than from supine radiographs (8.4±6.6mm, p<0.001), representing an 89% increase in displacement with upright positioning. Forty-one percent of patients had greater than 100% displacement on upright, but not on supine radiographs. Compared to the uninjured side, 3.0±10.7mm of shortening was noted on upright radiographs and 1.3±9.5mm of lengthening on supine radiographs (p<0.001). The ICC was 0.82 (95% CI: 0.73–0.89) for OTA fracture classification, 0.81 (95% CI: 0.75–0.87) for vertical displacement, and 0.92 (95% CI: 0.88–0.95) for injured clavicle length, demonstrating very high agreement among evaluators. Conclusions Increased fracture displacement and shortening was observed on upright compared to supine radiographs. This suggests that upright radiographs may better demonstrate clavicle displacement and predict the position at healing if nonoperative treatment is selected. PMID:24740113

  8. Research of misalignment between dithered ring laser gyro angle rate input axis and dither axis

    NASA Astrophysics Data System (ADS)

    Li, Geng; Wu, Wenqi; FAN, Zhenfang; LU, Guangfeng; Hu, Shaomin; Luo, Hui; Long, Xingwu

    2014-12-01

    The strap-down inertial navigation system (SINS), especially the SINS composed by dithered ring laser gyroscope (DRLG) is a kind of equipment, which providing high reliability and performance for moving vehicles. However, the mechanical dither which is used to eliminate the "Lock-In" effect can cause vibration disturbance to the INS and lead to dithering coupling problem in the inertial measurement unit (IMU) gyroscope triad, so its further application is limited. Among DRLG errors between the true gyro rotation rate and the measured rotation rate, the frequently considered one is the input axis misalignment between input reference axis which is perpendicular to the mounting surface and gyro angular rate input axis. But the misalignment angle between DRLG dither axis and gyro angular rate input axis is often ignored by researchers, which is amplified by dither coupling problem and that would lead to negative effects especially in high accuracy SINS. In order to study the problem more clearly, the concept of misalignment between DRLG dither axis and gyro angle rate input axis is researched. Considering the error of misalignment is of the order of 10-3 rad. or even smaller, the best way to measure it is using DRLG itself by means of an angle exciter as an auxiliary. In this paper, the concept of dither axis misalignment is explained explicitly firstly, based on this, the frequency of angle exciter is induced as reference parameter, when DRLG is mounted on the angle exciter in a certain angle, the projections of angle exciter rotation rate and mechanical oscillation rate on the gyro input axis are both sensed by DRLG. If the dither axis has misalignment error with the gyro input axis, there will be four major frequencies detected: the frequency of angle exciter, the dither mechanical frequency, sum and difference frequencies of the former two frequencies. Then the amplitude spectrum of DRLG output signal obtained by the using LabVIEW program. if there are only angle

  9. Comparison of the iAssist Handheld Guidance System to Conventional Instruments for Mechanical Axis Restoration in Total Knee Arthroplasty.

    PubMed

    Kinney, Matthew C; Cidambi, Krishna R; Severns, Dustyn L; Gonzales, Francis B

    2018-01-01

    Recent advances in total knee arthroplasty (TKA) include an intelligent instrument system designed to provide intraoperative guidance to reduce mechanical alignment errors. Internal position-sensing technology is integrated into microelectronic pods that attach to cutting blocks. The purpose of this prospective, randomized study was to determine whether this iAssist system enables the surgeon to make more accurate bone resections and better restore the mechanical axis compared to conventional instruments in TKA. We randomized patients undergoing TKA into 2 groups. Group I (n = 25) underwent TKA assisted by the iAssist guidance system, group II (n = 25) underwent TKA using conventional instruments. Preoperative and postoperative mechanical axes were measured from full-length lower extremity radiographs to evaluate alignment. Additional surgical parameters were also assessed, including tourniquet time and blood loss. Patient demographics and preoperative mechanical axis alignments were similar between the groups. Postoperatively, 4.0% of patients had greater than 3° of tibial or femoral component mal-alignment in the guidance-assisted cohort, compared with 36.0% in the conventional group (P < .05). Additionally, group I showed significant improvement in variance seen in both the femoral mechanical axis (1.65° ± 0.17° vs 2.23° ± 0.33°, P < .005) and tibial mechanical axis (1.28° ± 0.13° vs 1.71° ± 0.24°, P < .005) compared to group II. There were no significant differences in tourniquet time (P = .86) or blood loss (P = .39) between groups. Use of the iAssist system in TKA results in an improved postoperative mechanical axis and decreased alignment variability compared to conventional instruments, without significantly increasing operative time. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Radiographic Measurement of Displacement in Acetabular Fractures: A Systematic Review of the Literature.

    PubMed

    Dodd, Andrew; Osterhoff, Georg; Guy, Pierre; Lefaivre, Kelly A

    2016-06-01

    To report methods of measurement of radiographic displacement and radiographic outcomes in acetabular fractures described in the literature. A systematic review of the English literature was performed using EMBASE and Medline in August 2014. Inclusion criteria were studies of operatively treated acetabular fractures in adults with acute (<6 weeks) open reduction and internal fixation that reported radiographic outcomes. Exclusion criteria included case series with <10 patients, fractures managed >6 weeks from injury, acute total hip arthroplasty, periprosthetic fractures, time frame of radiographic outcomes not stated, missing radiographic outcome data, and non-English language articles. Basic information collected included journal, author, year published, number of fractures, and fracture types. Specific data collected included radiographic outcome data, method of measuring radiographic displacement, and methods of interpreting or categorizing radiographic outcomes. The number of reproducible radiographic measurement techniques (2/64) and previously described radiographic interpretation methods (4) were recorded. One radiographic reduction grading criterion (Matta) was used nearly universally in articles that used previously described criteria. Overall, 70% of articles using this criteria documented anatomic reductions. The current standard of measuring radiographic displacement in publications dealing with acetabulum fractures almost universally lacks basic description, making further scientific rigor, such as testing reproducibility, impossible. Further work is necessary to standardize radiographic measurement techniques, test their reproducibility, and qualify their validity or determine which measurements are important to clinical outcomes. Diagnostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

  11. Radiographic anatomy of the foot and ankle—part 4: the metatarsals.

    PubMed

    Christman, Robert A

    2015-01-01

    The normal radiographic anatomy of the foot and ankle, aside from my previous work, has been addressed only superficially or sparingly in the medical literature. This project correlates the detailed radiographic anatomy of the entire adult foot and ankle (two-dimensional) to osteology (three-dimensional). Each bone's position was determined after meticulous examination and correlation to an articulated skeleton relative to the image receptor and direction of the x-ray beam, with correlation to the radiograph for confirmation. Images of each foot and distal leg bone ("front" and "back" perspectives) are presented alongside a corresponding radiographic image for comparison. The normal gross and radiographic anatomy is correlated and described for each radiographic positioning technique. Foundational knowledge is provided that future researchers can use as a baseline ("normal") and that students and practitioners can use for comparison when interpreting radiographs and distinguishing abnormal findings. The results of the original project, owing to its broad scope, have been divided into five parts: the lower leg, the greater tarsus, the lesser tarsus, the metatarsals (the focus of this article), and the phalanges.

  12. Radiographic anatomy of the foot and ankle-part 5. The phalanges.

    PubMed

    Christman, Robert A

    2015-03-01

    The normal radiographic anatomy of the foot and ankle, aside from my previous work, has been addressed only superficially or sparingly in the medical literature. This project correlates the detailed radiographic anatomy of the entire adult foot and ankle (two-dimensional) to osteology (three-dimensional). Each bone's position was determined after meticulous examination and correlation to an articulated skeleton relative to the image receptor and direction of the x-ray beam, with correlation to the radiograph for confirmation. Images of each foot and distal leg bone ("front" and "back" perspectives) are presented alongside a corresponding radiographic image for comparison. The normal gross and radiographic anatomy is correlated and described for each radiographic positioning technique. Foundational knowledge is provided that future researchers can use as a baseline ("normal") and that students and practitioners can use for comparison when interpreting radiographs and distinguishing abnormal findings. The results of the original project, owing to its broad scope, have been divided into five parts: the lower leg, the greater tarsus, the lesser tarsus, the metatarsals, and the phalanges (the focus of this article).

  13. 21 CFR 892.1970 - Radiographic ECG/respirator synchronizer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radiographic ECG/respirator synchronizer. 892.1970 Section 892.1970 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1970 Radiographic ECG/respirator...

  14. Radiographic and scintigraphic evaluation of total knee arthroplasty

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Schneider, R.; Soudry, M.

    1986-04-01

    Various radiographic and scintigraphic methods are used to supplement clinical findings in the evaluation of total knee arthroplasty and its complications. Serial roentgenograms offer reliable information for diagnosing mechanical loosening. Wide and extensive radiolucency at the cement-bone interface and shift in position and alignment of prosthetic components can be seen in almost all cases by the time revision is necessary. Radiographic abnormalities are usually not present in acute infection, but are often present in chronic infection. Bone scanning has a high sensitivity for diagnosis of infection or loosening, but is nonspecific because increased uptake is often present around asymptomatic totalmore » knee arthroplasties with normal radiographs. Differential bone and Gallium scanning and scanning with Indium 111-labeled leukocytes have a greater specificity for diagnosis of infection than does bone or Gallium scanning alone. Routine radiographic and scintigraphic studies have shown a high incidence of deep vein thrombosis in the calf after total knee arthroplasty. Clinically significant pulmonary embolization is infrequent.« less

  15. Justification of radiographic examinations: What are the key issues?

    PubMed

    Vom, Jason; Williams, Imelda

    2017-09-01

    Justification of radiographic examinations is the practice of evaluating requested radiological examinations to assess for clinical merit and appropriateness based on clinical notes and patient information. This implies that justification in radiography requires the evaluation of requested examinations, the justification of exposures being applied and determining whether patients fit the recommended criteria for the procedure. Medico-legal requirements by the professional registration body, the Medical Radiation Practice Board of Australia (MRPBA), identify justification as an advocated and obligatory practice for radiographers. Yet, justification remains an inconsistent practice implemented amongst Australian radiographers. This review aims to identify associated barriers inhibiting the consistent practice of justification and the hesitance by radiographers in practicing justification responsibilities. It also recommends a change in workplace culture which encourages radiographers to accept a more autonomous role that cultivates critical thinking, reflection and research-informed decision making as justification will ultimately benefit patients. © 2017 The Authors. Journal of Medical Radiation Sciences published by John Wiley & Sons Australia, Ltd on behalf of Australian Society of Medical Imaging and Radiation Therapy and New Zealand Institute of Medical Radiation Technology.

  16. Radiographic inspection of porosity in pure titanium dumbbell castings.

    PubMed

    Nuñez, Juliana Maria Costa; Takahashi, Jessica Mie Ferreira Koyama; Henriques, Guilherme Elias Pessanha; Nóbilo, Mauro Antônio de Arruda; Consani, Rafael Leonardo Xediek; Mesquita, Marcelo Ferraz

    2011-09-01

      Titanium frameworks are frequently indicated for implant supported prostheses; however, voids are usually encountered inside cast titanium.   This study aimed to confirm the efficacy of a radiographic technique for inspection of porosity in commercially pure titanium castings with different diameter.   Sixty dumbbell rods (n=20) with a central 1.5, 2.0 and 3.5mm diameter were prepared by lost-wax casting. Cast specimens were finished and polished and submitted to radiographic examination (90kV, 15mA, 0.6s and 10-13mm of distance) using periapical film. The radiographs were visually analysed for the presence of porosity in the extension of the dumbbell or in the central portion of the rods. Data were submitted to Pearson Chi-square test (5%).   The tested radiographic method proved to be suitable for the evaluation of cast frameworks. Internal porosities were observed in most of the specimens (91.7%) (p=0.0005); however, only 20% occurred on the central portion of the rods (p=0.612).   Internal porosities can be visualised through radiographs and occur mostly in small diameter structures. The radiographic evaluation of metal structures can improve the quality of frameworks and thereby potentially increase the longevity of the rehabilitation. © 2010 The Gerodontology Society and John Wiley & Sons A/S.

  17. Sex differences in activated CRF neurons within stress-related neurocircuitry and HPA axis hormones following restraint in rats

    PubMed Central

    Babb, Jessica A; Masini, Cher V; Day, Heidi E W; Campeau, Serge

    2013-01-01

    Women may be more vulnerable to certain stress-related psychiatric illnesses than men due to differences in hypothalamic-pituitary-adrenocortical (HPA) axis function. To investigate potential sex differences in forebrain regions associated with HPA axis activation in rats, these experiments utilized acute exposure to a psychological stressor. Male and female rats in various stages of the estrous cycle were exposed to 30 min of restraint, producing a robust HPA axis hormonal response in all animals, the magnitude of which was significantly higher in female rats. Although both male and female animals displayed equivalent c-fos expression in many brain regions known to be involved in the detection of threatening stimuli, three regions had significantly higher expression in females: the paraventricular nucleus of the hypothalamus (PVN), the anteroventral division of the bed nucleus of the stria terminalis (BSTav), and the medial preoptic area (MPOA). Dual fluorescence in-situ hybridization analysis of neurons containing c-fos and corticotropin-releasing factor (CRF) mRNA in these regions revealed significantly more c-fos and CRF single-labeled neurons, as well as significantly more double-labeled neurons in females. Surprisingly, there was no effect of the estrous cycle on any measure analyzed, and an additional experiment revealed no demonstrable effect of estradiol replacement following ovariectomy on HPA axis hormone induction following stress. Taken together, these data suggest sex differences in HPA axis activation in response to perceived threat may be influenced by specific populations of CRF neurons in key stress-related brain regions, the BSTav, MPOA, and PVN, which may be independent of circulating sex steroids. PMID:23305762

  18. Rate of abnormal osteoarticular radiographic findings in pediatric patients.

    PubMed

    Petit, P; Sapin, C; Henry, G; Dahan, M; Panuel, M; Bourlière-Najean, B; Chaumoitre, K; Devred, P

    2001-04-01

    The objective of our study was to assess the rate of abnormal radiographic findings in the most frequent osteoarticular locations of traumatic injury in a pediatric population. During two periods of 12 weeks each, all patients admitted to the pediatric emergency department for osteoarticular trauma who underwent radiography were prospectively included in this study. A connection was drawn between the rate of abnormal radiographic findings for the seven most frequently radiographed locations and the clinical findings. Of 3128 locations of trauma in 2470 children, only 22% of the radiographic examinations were considered to reveal abnormal findings. In decreasing order, the hand and fingers, the ankle, the wrist, the knee, the elbow, the foot and toes, and the forearm were the most frequently examined locations. The rate of abnormal findings was 25.7% for the hand and fingers, 9.0% for the ankle, 42.5% for the wrist, 9.5% for the knee, 33.3% for the elbow, 18.3% for the foot, and 43.2% for the forearm. When only the direct sign of fracture was taken into account, these rates decreased for the ankle and knee to 2.6% and 1.9%, respectively. There was always a significant link between the degree of clinical suspicion and the rate of abnormal radiographic findings. However, fewer than 50% of the cases with high clinical suspicion of fracture were radiographically confirmed. It appears necessary, especially in cases of lower limb trauma, to evaluate clinical tests, including the implementation of the Ottawa ankle rules, to reduce the number of unnecessary radiographic examinations. This reduction will improve some parameters of children's quality of life and will significantly decrease the cost of emergency care.

  19. Dual-fuel, dual-throat engine preliminary analysis

    NASA Technical Reports Server (NTRS)

    Obrien, C. J.

    1979-01-01

    A propulsion system analysis of the dual fuel, dual throat engine for launch vehicle applications was conducted. Basic dual throat engine characterization data were obtained to allow vehicle optimization studies to be conducted. A preliminary baseline engine system was defined.

  20. Development of a Gimballed, dual frequency, space-based, microwave antenna for volume production

    NASA Technical Reports Server (NTRS)

    Leckie, Martin; Laidig, Dave

    1996-01-01

    A dual-frequency, two-axis Gimballed, Microwave Antenna (GMA) has been developed by COM DEV and Motorola for commercial satellites. The need for volume production of over three hundred antennas at a rate of four per week, a compressed development schedule, and the commercial nature of the effort necessitated a paradigm shift to an 'overall' cost-driven design approach. The translation of these demands into antenna requirements, a description of the resulting GMA design, and examples of development issues are detailed herein.

  1. Radiographic classifications in Perthes disease

    PubMed Central

    Huhnstock, Stefan; Svenningsen, Svein; Merckoll, Else; Catterall, Anthony; Terjesen, Terje; Wiig, Ola

    2017-01-01

    Background and purpose Different radiographic classifications have been proposed for prediction of outcome in Perthes disease. We assessed whether the modified lateral pillar classification would provide more reliable interobserver agreement and prognostic value compared with the original lateral pillar classification and the Catterall classification. Patients and methods 42 patients (38 boys) with Perthes disease were included in the interobserver study. Their mean age at diagnosis was 6.5 (3–11) years. 5 observers classified the radiographs in 2 separate sessions according to the Catterall classification, the original and the modified lateral pillar classifications. Interobserver agreement was analysed using weighted kappa statistics. We assessed the associations between the classifications and femoral head sphericity at 5-year follow-up in 37 non-operatively treated patients in a crosstable analysis (Gamma statistics for ordinal variables, γ). Results The original lateral pillar and Catterall classifications showed moderate interobserver agreement (kappa 0.49 and 0.43, respectively) while the modified lateral pillar classification had fair agreement (kappa 0.40). The original lateral pillar classification was strongly associated with the 5-year radiographic outcome, with a mean γ correlation coefficient of 0.75 (95% CI: 0.61–0.95) among the 5 observers. The modified lateral pillar and Catterall classifications showed moderate associations (mean γ correlation coefficient 0.55 [95% CI: 0.38–0.66] and 0.64 [95% CI: 0.57–0.72], respectively). Interpretation The Catterall classification and the original lateral pillar classification had sufficient interobserver agreement and association to late radiographic outcome to be suitable for clinical use. Adding the borderline B/C group did not increase the interobserver agreement or prognostic value of the original lateral pillar classification. PMID:28613966

  2. Detection of occult, undisplaced hip fractures with a dual-energy CT algorithm targeted to detection of bone marrow edema.

    PubMed

    Reddy, T; McLaughlin, P D; Mallinson, P I; Reagan, A C; Munk, P L; Nicolaou, S; Ouellette, H A

    2015-02-01

    The purpose of this study is to describe our initial clinical experience with dual-energy computed tomography (DECT) virtual non-calcium (VNC) images for the detection of bone marrow (BM) edema in patients with suspected hip fracture following trauma. Twenty-five patients presented to the emergency department at a level 1 trauma center between January 1, 2011 and January 1, 2013 with clinical suspicion of hip fracture and normal radiographs were included. All CT scans were performed on a dual-source, dual-energy CT system. VNC images were generated using prototype software and were compared to regular bone reconstructions by two musculoskeletal radiologists in consensus. Radiological and/or clinical diagnosis of fracture at 30-day follow-up was used as the reference standard. Twenty-one patients were found to have DECT-VNC signs of bone marrow edema. Eighteen of these 21 patients were true positive and three were false positive. A concordant fracture was clearly seen on bone reconstruction images in 15 of the 18 true positive cases. In three cases, DECT-VNC was positive for bone marrow edema where bone reconstruction CT images were negative. Four patients demonstrated no DECT-VNC signs of bone marrow edema: two cases were true negative, two cases were false negative. When compared with the gold standard of hip fracture determined at retrospective follow-up, the sensitivity of DECT-VNC images of the hip was 90 %, specificity was 40 %, positive predictive value was 86 %, and negative predictive value was 50 %. Our initial experience would suggest that DECT-VNC is highly sensitive but poorly specific in the diagnosis of hip fractures in patients with normal radiographs. The value of DECT-VNC primarily lies in its ability to help detect fractures which may be subtle or undetectable on bone reconstruction CT images.

  3. Radiographers' areas of professional competence related to good nursing care.

    PubMed

    Andersson, Bodil T; Fridlund, Bengt; Elgán, Carina; Axelsson, Asa B

    2008-09-01

    Radiographers' ability and competence is a matter of vital importance for patients. Nursing care is an integral part of the radiographer's work. The demand for high competence in clinical activities has increased in diagnostic radiology and has had an impact on the development of the profession. The aim was to describe the radiographer's areas of professional competence in relation to good nursing care based on critical incidents that occur in the course of radiological examinations and interventions. A descriptive design with a qualitative approach, using the Critical Incident Technique was employed. Interviews were conducted with a strategic sample of registered radiographers (n = 14), based at different hospitals in Sweden. The appropriate ethical principles were followed. All the participants provided informed consent, and formal approval for conducting the research was obtained according to national and local directives. The data analysis resulted in two main areas; direct and indirect patient-related areas of competence, which describe the radiographers' skills that either facilitate or hinder good nursing care. In the direct patient-related area of competence, four categories emerged, which illustrate good nursing care in the patient's immediate surroundings. In the indirect patient-related area of competence, four categories illuminated good nursing care that is provided without direct contact with the patient. The study highlights the different areas of the radiographer's unique professional competence. The findings provide insight into the radiographer's profession, on one hand as a carer and on the other as a medical technologist as well as highlighting the importance of each role. The radiographer's work encompasses a variety of components--from caring for the patient to handling and checking the technical equipment.

  4. Signal Acquisition Using AXIe

    NASA Astrophysics Data System (ADS)

    Narciso, Steven J.

    2011-08-01

    An emerging test and measurement standard called AXIe, AdvancedTCA extensions for Instrumentation, is expected to find wide acceptance within the Physics community as it offers many benefits to applications including shock, plasma, particle and nuclear physics. It is expected that many COTS (commercial off-the-shelf) signal conditioning, acquisition and processing modules will become available from a range of different suppliers. AXIe uses AdvancedTCA® as its basis, but then levers test and measurement industry standards such as PXI, IVI, and LXI to facilitate cooperation and plug-and-play interoperability between COTS instrument suppliers. AXIe's large board footprint and power allows high density in a 19" rack, enabling the development of high-performance signal conditioning, analog-to-digital conversion, and data processing, while offering channel count scalability inherent in modular systems. Synchronization between modules is flexible and provided by two triggering structures: a parallel trigger bus, and radially-distributed, time-matched point-to-point trigger lines. Inter-module communication is also provided with an adjacent module local bus allowing data transfer to 600 Gbits/s in each direction, for example between a front-end digitizer and DSP. AXIe allows embedding high performance computing and a range of COTS AdvancedTCA® computer blades are currently available that provide low cost alternatives to the development of custom signal processing modules. The availability of both LAN and PCI Express allow interconnection between modules, as well as industry-standard high-performance data paths to external host computer systems. AXIe delivers a powerful environment for custom module devel opment. As in the case of VXIbus and PXI before it, commercial development kits are expected to be available. This paper will give an overview of the architectural elements of AXIe 1.0, the compatibility model with AdvancedTCA, and signal acquisition performance of many

  5. Off-axis reflective optical apparatus

    NASA Technical Reports Server (NTRS)

    Ames, Lawrence L. (Inventor); Leary, David F. (Inventor); Mammini, Paul V. (Inventor)

    2005-01-01

    Embodiments of the present invention are directed to a simple apparatus and a convenient and accurate method of mounting the components to form an off-axis reflective optical apparatus such as a collimator. In one embodiment, an off-axis reflective optical apparatus comprises a mounting block having a ferrule holder support surface and an off-axis reflector support surface which is generally perpendicular to the ferrule holder support surface. An optical reflector is mounted on the off-axis reflector support surface and has a reflected beam centerline. The optical reflector has a conic reflective surface and a conic center. A ferrule holder is mounted on the ferrule holder support surface. The ferrule holder provides a ferrule for coupling to an optical fiber and orienting a fiber tip of the optical fiber along a fiber axis toward the optical reflector. The fiber axis is nonparallel to the reflected beam centerline. Prior to mounting the optical reflector to the off-axis reflector support surface and prior to mounting the ferrule holder to the ferrule holder support surface, the optical reflector is movable on the off-axis reflector surface and the ferrule holder is movable on the ferrule holder support surface to align the conic center of the optical reflector with respect to the fiber tip of the optical fiber, and the apparatus has at least one of the following features: (1) the optical reflector is movable on the off-axis reflector support surface to adjust a focus of the fiber tip with respect to the optical reflector, and (2) the ferrule holder is movable on the ferrule holder support surface to adjust the focus of the fiber tip with respect to the optical reflector.

  6. Gut Microbiota-brain Axis

    PubMed Central

    Wang, Hong-Xing; Wang, Yu-Ping

    2016-01-01

    Objective: To systematically review the updated information about the gut microbiota-brain axis. Data Sources: All articles about gut microbiota-brain axis published up to July 18, 2016, were identified through a literature search on PubMed, ScienceDirect, and Web of Science, with the keywords of “gut microbiota”, “gut-brain axis”, and “neuroscience”. Study Selection: All relevant articles on gut microbiota and gut-brain axis were included and carefully reviewed, with no limitation of study design. Results: It is well-recognized that gut microbiota affects the brain's physiological, behavioral, and cognitive functions although its precise mechanism has not yet been fully understood. Gut microbiota-brain axis may include gut microbiota and their metabolic products, enteric nervous system, sympathetic and parasympathetic branches within the autonomic nervous system, neural-immune system, neuroendocrine system, and central nervous system. Moreover, there may be five communication routes between gut microbiota and brain, including the gut-brain's neural network, neuroendocrine-hypothalamic-pituitary-adrenal axis, gut immune system, some neurotransmitters and neural regulators synthesized by gut bacteria, and barrier paths including intestinal mucosal barrier and blood-brain barrier. The microbiome is used to define the composition and functional characteristics of gut microbiota, and metagenomics is an appropriate technique to characterize gut microbiota. Conclusions: Gut microbiota-brain axis refers to a bidirectional information network between the gut microbiota and the brain, which may provide a new way to protect the brain in the near future. PMID:27647198

  7. 42 CFR 37.44 - Approval of radiographic facilities that use digital radiography systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... image acquisition, digitization, processing, compression, transmission, display, archiving, and... quality digital chest radiographs by submitting to NIOSH digital radiographic image files of a test object... digital radiographic image files from six or more sample chest radiographs that are of acceptable quality...

  8. 42 CFR 37.44 - Approval of radiographic facilities that use digital radiography systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... image acquisition, digitization, processing, compression, transmission, display, archiving, and... quality digital chest radiographs by submitting to NIOSH digital radiographic image files of a test object... digital radiographic image files from six or more sample chest radiographs that are of acceptable quality...

  9. Radiographic Features of Acute Patellar Tendon Rupture.

    PubMed

    Fazal, Muhammad Ali; Moonot, Pradeep; Haddad, Fares

    2015-11-01

    The purpose of our study was to assess soft tissue features of acute patellar tendon rupture on lateral knee radiograph that would facilitate early diagnosis. The participants were divided into two groups of 35 patients each. There were 28 men and seven women with a mean age of 46 years in the control group and 26 men and nine women with a mean age of 47 years in the rupture group. The lateral knee radiograph of each patient was evaluated for Insall-Salvati ratio for patella alta, increased density of the infrapatellar fat pad, appearance of the soft tissue margin of the patellar tendon and bony avulsions. In the rupture group there were three consistent soft tissue radiographic features in addition to patellar alta. These were increased density of infrapatellar fat pad; loss of sharp, well-defined linear margins of the patellar tendon and angulated wavy margin of the patellar tendon while in the control group these features were not observed. The soft tissue radiographic features described in the rupture group are consistent and reliable. When coupled with careful clinical assessment, these will aid in early diagnosis and further imaging will be seldom required. © 2015 Chinese Orthopaedic Association and Wiley Publishing Asia Pty Ltd.

  10. Radiographic abnormalities among construction workers exposed to quartz containing dust

    PubMed Central

    Tjoe, N; Burdorf, A; Parker, J; Attfield, M; van Duivenbooden, C; Heederik, D

    2003-01-01

    Background: Construction workers are exposed to quartz containing respirable dust, at levels that may cause fibrosis in the lungs. Studies so far have not established a dose-response relation for radiographic abnormalities for this occupational group. Aims: To measure the extent of radiographic abnormalities among construction workers primarily exposed to quartz containing respirable dust. Methods: A cross sectional study on radiographic abnormalities indicative of pneumoconiosis was conducted among 1339 construction workers mainly involved in grinding, (jack)-hammering, drilling, cutting, sawing, and polishing. Radiological abnormalities were determined by median results of the 1980 International Labour Organisation system of three certified "B" readers. Questionnaires were used for assessment of occupational history, presence of respiratory diseases, and symptoms and smoking habits. Results: An abnormality of ILO profusion category 1/0 and greater was observed on 10.2% of the chest radiographs, and profusion category of 1/1 or greater on 2.9% of the radiographs. The average duration of exposure of this group was 19 years and the average age was 42. The predominant type of small opacities (irregularly shaped) is presumably indicative of mixed dust pneumoconiosis. The prevalence of early signs of nodular silicosis (small rounded opacities of category 1/0 or greater) was low (0.8%). Conclusions: The study suggests an elevated risk of radiographic abnormalities among these workers with expected high exposure. An association between radiographic abnormalities and cumulative exposure to quartz containing dust from construction sites was observed, after correction for potentially confounding variables. PMID:12771392

  11. Cross-axis adaptation of torsional components in the yaw-axis vestibulo-ocular reflex

    NASA Technical Reports Server (NTRS)

    Trillenberg, P.; Shelhamer, M.; Roberts, D. C.; Zee, D. S.

    2003-01-01

    The three pairs of semicircular canals within the labyrinth are not perfectly aligned with the pulling directions of the six extraocular muscles. Therefore, for a given head movement, the vestibulo-ocular reflex (VOR) depends upon central neural mechanisms that couple the canals to the muscles with the appropriate functional gains in order to generate a response that rotates the eye the correct amount and around the correct axis. A consequence of these neural connections is a cross-axis adaptive capability, which can be stimulated experimentally when head rotation is around one axis and visual motion about another. From this visual-vestibular conflict the brain infers that the slow-phase eye movement is rotating around the wrong axis. We explored the capability of human cross-axis adaptation, using a short-term training paradigm, to determine if torsional eye movements could be elicited by yaw (horizontal) head rotation (where torsion is normally inappropriate). We applied yaw sinusoidal head rotation (+/-10 degrees, 0.33 Hz) and measured eye movement responses in the dark, and before and after adaptation. The adaptation paradigm lasted 45-60 min, and consisted of the identical head motion, coupled with a moving visual scene that required one of several types of eye movements: (1) torsion alone (-Roll); (2) horizontal/torsional, head right/CW torsion (Yaw-Roll); (3) horizontal/torsional, head right/CCW torsion (Yaw+Roll); (4) horizontal, vertical, torsional combined (Yaw+Pitch-Roll); and (5) horizontal and vertical together (Yaw+Pitch). The largest and most significant changes in torsional amplitude occurred in the Yaw-Roll and Yaw+Roll conditions. We conclude that short-term, cross-axis adaptation of torsion is possible but constrained by the complexity of the adaptation task: smaller torsional components are produced if more than one cross-coupling component is required. In contrast, vertical cross-axis components can be easily trained to occur with yaw head

  12. [Transparency regime: semiotics of radiographical images in urological diagnostics].

    PubMed

    Martin, M; Fangerau, H

    2012-10-01

    Shortly after Röntgen discovered x-rays urology became one of the main test fields for the application of this new technology. Initial scepticism among physicians, who were inclined to cling to traditional manual methods of diagnosing, was replaced by enthusiasm for radiographic technologies and the new method soon became the standard in, for example the diagnosis of concrements. Patients favoring radiographic procedures over the use of probes and a convincing documentation of stones in radiograms were factors that impacted the relatively rapid integration of radiology into urology. The radiographic representation of soft tissues and body cavities was more difficult and the development of contrast agents in particular posed a serious problem. Several patients died during this research. A new diagnostic dimension was revealed when radiography and cystography were combined to form the method of retrograde pyelography. However, the problem of how urologists could learn how to read the new images remained. In order to allow trainee physicians to practice interpreting radiograms atlases were produced which offered explanatory texts and drawings for radiographic images of the kidneys, the bladder etc. Thus, urologists developed a self-contained semiotics which facilitated the appropriation of a unique urological radiographical gaze.

  13. Validation of a novel technique for creating simulated radiographs using computed tomography datasets.

    PubMed

    Mendoza, Patricia; d'Anjou, Marc-André; Carmel, Eric N; Fournier, Eric; Mai, Wilfried; Alexander, Kate; Winter, Matthew D; Zwingenberger, Allison L; Thrall, Donald E; Theoret, Christine

    2014-01-01

    Understanding radiographic anatomy and the effects of varying patient and radiographic tube positioning on image quality can be a challenge for students. The purposes of this study were to develop and validate a novel technique for creating simulated radiographs using computed tomography (CT) datasets. A DICOM viewer (ORS Visual) plug-in was developed with the ability to move and deform cuboidal volumetric CT datasets, and to produce images simulating the effects of tube-patient-detector distance and angulation. Computed tomographic datasets were acquired from two dogs, one cat, and one horse. Simulated radiographs of different body parts (n = 9) were produced using different angles to mimic conventional projections, before actual digital radiographs were obtained using the same projections. These studies (n = 18) were then submitted to 10 board-certified radiologists who were asked to score visualization of anatomical landmarks, depiction of patient positioning, realism of distortion/magnification, and image quality. No significant differences between simulated and actual radiographs were found for anatomic structure visualization and patient positioning in the majority of body parts. For the assessment of radiographic realism, no significant differences were found between simulated and digital radiographs for canine pelvis, equine tarsus, and feline abdomen body parts. Overall, image quality and contrast resolution of simulated radiographs were considered satisfactory. Findings from the current study indicated that radiographs simulated using this new technique are comparable to actual digital radiographs. Further studies are needed to apply this technique in developing interactive tools for teaching radiographic anatomy and the effects of varying patient and tube positioning. © 2013 American College of Veterinary Radiology.

  14. Radiographic visualization of magma dynamics in an erupting volcano.

    PubMed

    Tanaka, Hiroyuki K M; Kusagaya, Taro; Shinohara, Hiroshi

    2014-03-10

    Radiographic imaging of magma dynamics in a volcanic conduit provides detailed information about ascent and descent of magma, the magma flow rate, the conduit diameter and inflation and deflation of magma due to volatile expansion and release. Here we report the first radiographic observation of the ascent and descent of magma along a conduit utilizing atmospheric (cosmic ray) muons (muography) with dynamic radiographic imaging. Time sequential radiographic images show that the top of the magma column ascends right beneath the crater floor through which the eruption column was observed. In addition to the visualization of this magma inflation, we report a sequence of images that show magma descending. We further propose that the monitoring of temporal variations in the gas volume fraction of magma as well as its position in a conduit can be used to support existing eruption prediction procedures.

  15. Endoscopic subcondylar fracture repair: functional, aesthetic, and radiographic outcomes.

    PubMed

    Lee, C; Mueller, R V; Lee, K; Mathes, S J

    1998-10-01

    An endoscopic method of mandibular subcondylar fracture repair has been described recently. To determine the effectiveness of this new technique, we longitudinally studied functional, aesthetic, and radiographic parameters following endoscopic repair of 22 subcondylar fractures in 20 patients. Restoration of mandibular function was achieved without postoperative maxillomandibular fixation. Premorbid occlusion was restored. Clinical jaw motion was found to progressively increase with a mean interincisal jaw opening of 43 mm achieved after the eighth postoperative week. Patients were pleased with the aesthetic restoration of their chin projection,jaw line, and the symmetric midline movement of the chin point onjaw opening. Anatomic fracture reduction with rigid plate fixation was confirmed on early postsurgical radiographs. Late radiographs showed fracture union without remodeling of the condylar head. Endoscopic subcondylar fracture repair was efficacious at functional, aesthetic, and radiographic restoration of the mandible.

  16. Radiographic visualization of magma dynamics in an erupting volcano

    PubMed Central

    Tanaka, Hiroyuki K. M.; Kusagaya, Taro; Shinohara, Hiroshi

    2014-01-01

    Radiographic imaging of magma dynamics in a volcanic conduit provides detailed information about ascent and descent of magma, the magma flow rate, the conduit diameter and inflation and deflation of magma due to volatile expansion and release. Here we report the first radiographic observation of the ascent and descent of magma along a conduit utilizing atmospheric (cosmic ray) muons (muography) with dynamic radiographic imaging. Time sequential radiographic images show that the top of the magma column ascends right beneath the crater floor through which the eruption column was observed. In addition to the visualization of this magma inflation, we report a sequence of images that show magma descending. We further propose that the monitoring of temporal variations in the gas volume fraction of magma as well as its position in a conduit can be used to support existing eruption prediction procedures. PMID:24614612

  17. Early diagnosis of osteoporosis using radiogrammetry and texture analysis from hand and wrist radiographs in Indian population.

    PubMed

    Areeckal, A S; Jayasheelan, N; Kamath, J; Zawadynski, S; Kocher, M; David S, S

    2018-03-01

    We propose an automated low cost tool for early diagnosis of onset of osteoporosis using cortical radiogrammetry and cancellous texture analysis from hand and wrist radiographs. The trained classifier model gives a good performance accuracy in classifying between healthy and low bone mass subjects. We propose a low cost automated diagnostic tool for early diagnosis of reduction in bone mass using cortical radiogrammetry and cancellous texture analysis of hand and wrist radiographs. Reduction in bone mass could lead to osteoporosis, a disease observed to be increasingly occurring at a younger age in recent times. Dual X-ray absorptiometry (DXA), currently used in clinical practice, is expensive and available only in urban areas in India. Therefore, there is a need to develop a low cost diagnostic tool in order to facilitate large-scale screening of people for early diagnosis of osteoporosis at primary health centers. Cortical radiogrammetry from third metacarpal bone shaft and cancellous texture analysis from distal radius are used to detect low bone mass. Cortical bone indices and cancellous features using Gray Level Run Length Matrices and Laws' masks are extracted. A neural network classifier is trained using these features to classify healthy subjects and subjects having low bone mass. In our pilot study, the proposed segmentation method shows 89.9 and 93.5% accuracy in detecting third metacarpal bone shaft and distal radius ROI, respectively. The trained classifier shows training accuracy of 94.3% and test accuracy of 88.5%. An automated diagnostic technique for early diagnosis of onset of osteoporosis is developed using cortical radiogrammetric measurements and cancellous texture analysis of hand and wrist radiographs. The work shows that a combination of cortical and cancellous features improves the diagnostic ability and is a promising low cost tool for early diagnosis of increased risk of osteoporosis.

  18. Plain abdominal radiographs in acute medical emergencies: an abused investigation?

    PubMed

    Feyler, S; Williamson, V; King, D

    2002-02-01

    Plain abdominal radiographs are commonly requested for acute medical emergencies on patients with non-specific abdominal symptoms and signs. In this study 131 plain abdominal radiographs performed on the day of admission were prospectively analysed. In only 16 cases (12%) the reasons for requests conformed to the recommended guidelines by the Royal College of Radiologists. The reason for the request was stated in the case notes in only three cases. In 62 cases (47%), there was no comment made on the film by the requesting clinician. There was a discrepancy in the interpretation of the radiograph between the clinician and the radiologist in 31 cases (24%). The clinical management was influenced by plain abdominal radiographs in only nine cases (7%). The majority of plain abdominal radiographs requested on acute medical emergencies is inappropriate. There is a need to ensure guidelines are followed to prevent unnecessary exposure of patients to radiation as well as preventing expenditure on irrelevant investigations.

  19. Plain abdominal radiographs in acute medical emergencies: an abused investigation?

    PubMed Central

    Feyler, S; Williamson, V; King, D

    2002-01-01

    Plain abdominal radiographs are commonly requested for acute medical emergencies on patients with non-specific abdominal symptoms and signs. In this study 131 plain abdominal radiographs performed on the day of admission were prospectively analysed. In only 16 cases (12%) the reasons for requests conformed to the recommended guidelines by the Royal College of Radiologists. The reason for the request was stated in the case notes in only three cases. In 62 cases (47%), there was no comment made on the film by the requesting clinician. There was a discrepancy in the interpretation of the radiograph between the clinician and the radiologist in 31 cases (24%). The clinical management was influenced by plain abdominal radiographs in only nine cases (7%). The majority of plain abdominal radiographs requested on acute medical emergencies is inappropriate. There is a need to ensure guidelines are followed to prevent unnecessary exposure of patients to radiation as well as preventing expenditure on irrelevant investigations. PMID:11807192

  20. A clinico-radiographic analysis of sagittal condylar guidance determined by protrusive interocclusal registration and panoramic radiographic images in humans

    PubMed Central

    Prasad, Krishna D.; Shah, Namrata; Hegde, Chethan

    2012-01-01

    Purpose: To evaluate the correlation between sagittal condylar guidance obtained by protrusive interocclusal records and panoramic radiograph tracing methods in human dentulous subjects. Materials and Methods: The sagittal condylar guidance was determined in 75 dentulous subjects by protrusive interocclusal records using Aluwax through a face bow transfer (HANAU™ Spring Bow, Whip Mix Corporation, USA) to a semi-adjustable articulator (HANAU™ Wide-Vue Articulator, Whip Mix Corporation, USA). In the same subjects, the sagittal outline of the articular eminence and glenoid fossa was traced in panoramic radiographs. The sagittal condylar path inclination was constructed by joining the heights of curvature in the glenoid fossa and the corresponding articular eminence. This was then related to the constructed Frankfurt's horizontal plane to determine the radiographic angle of sagittal condylar guidance. Results: A strong positive correlation existed between right and left condylar guidance by the protrusive interocclusal method (P 0.000) and similarly by the radiographic method (P 0.013). The mean difference between the condylar guidance obtained using both methods were 1.97° for the right side and 3.18° for the left side. This difference between the values by the two methods was found to be highly significant for the right (P 0.003) and left side (P 0.000), respectively. The sagittal condylar guidance obtained from both methods showed a significant positive correlation on right (P 0.000) and left side (P 0.015), respectively. Conclusion: Panoramic radiographic tracings of the sagittal condylar path guidance may be made relative to the Frankfurt's horizontal reference plane and the resulting condylar guidance angles used to set the condylar guide settings of semi-adjustable articulators. PMID:23633793

  1. Influence of dual-task constraints on the interaction between posture and movement during a lower limb pointing task.

    PubMed

    Silva, Marcelo Guimarães; Struber, Lucas; Brandão, José Geraldo T; Daniel, Olivier; Nougier, Vincent

    2018-04-01

    One of the challenges regarding human motor control is making the movement fluid and at a limited cognitive cost. The coordination between posture and movement is a necessary requirement to perform daily life tasks. The present experiment investigated this interaction in 20 adult men, aged 18-30 years. The cognitive costs associated to postural and movement control when kicking towards a target was estimated using a dual-task paradigm (secondary auditory task). Results showed that addition of the attentional demanding cognitive task yielded a decreased kicking accuracy and an increased timing to perform the movement, mainly during the backswing motion. In addition, significant differences between conditions were found for COP and COM displacement (increased amplitude, mean speed) on the anteroposterior axis. However, no significant differences between conditions were found on the mediolateral axis. Finally, EMG analysis showed that dual-task condition modified the way anticipatory postural adjustments (APAs) were generated. More specifically, we observed an increase of the peroneus longus activity, whereas the temporal EMG showed a decrease of its latency with respect to movement onset. These results suggested a functional adaptation resulting in an invariance of overall APAs, emphasizing that cognitive, postural, and motor processes worked dependently.

  2. Quantitative evaluation of distortion in sketching under mono and dual axes whole body vibration.

    PubMed

    Bhiwapurkar, M K; Saran, V H; Harsha, S P

    2011-01-01

    Performance of sedentary activities such as reading and writing, in trains is known to be affected by the vibrations. An experimental study was therefore initiated to investigate the interference perceived in sketching task under low frequency random vibration in both mono and dual axes. Thirty healthy male subjects participated in the study. Random vibration stimuli were excited in various axes in frequency range of 1-20 Hz at magnitudes of 0.4, 0.8 and 1.2 m/s(2). The task required the subjects to sketch the given geometric figures such as circle, rectangle and triangle under vibration environment in two subject postures (sketch pad on lap and on table). Three performance methods were used to measure the effect of vibration stimuli and posture. They consisted of two specifically designed objective methods for percentage distortion measurement and one subjective method using Borg CR10 scale. The results revealed that the percentage distortion and difficulty in sketching increased with an increase in vibration magnitude and was found to be higher for vibration in Y- and Z-axis. Similar trend was observed for percentage distortion and difficulty in sketching for dual axes also. The perceived difficulty and impairment in sketching performance was greater while sketching on lap for X-axis, while the effect was just the reverse for other axes.

  3. [Radiographic findings in raptors affected with a mycosis of the respiratory tract].

    PubMed

    Vorbrüggen, S; Bailey, T; Krautwald-Junghanns, M-E

    2013-01-01

    Summary of typical radiographic signs in birds of prey with aspergillosis compared to signs previously established in parrots. Evaluation of radiographs of 110 falcons (Falco spp.) with aspergillosis confirmed by endoscopy. Compared to parrots primarily subtle radiographic signs were detected in falcons (especially inhomogeneously increased radiodensities of the airsacs/lungs). Two typical signs for diseased falcons consisted of the poor delineation of the cardiac silhouette and the line-shaped increased radiodensity of the caudal lung border. Radiographic diagnosis of the lung is limited due to the strong flight musculature. The varying results between avian species can be explained by the different radiographic anatomy, husbandry conditions and x-ray technique (digital versus analog). A pet bird-experienced practitioner should be aware of specific radiographic signs in birds of prey suspected of having aspergillosis.

  4. 42 CFR 37.44 - Approval of radiographic facilities that use digital radiography systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... effective management, safety, and proper performance of chest image acquisition, digitization, processing... digital chest radiographs by submitting to NIOSH digital radiographic image files of a test object (e.g... radiographic image files from six or more sample chest radiographs that are of acceptable quality to one or...

  5. Video enhancement of X-ray and neutron radiographs

    NASA Technical Reports Server (NTRS)

    Vary, A.

    1973-01-01

    System was devised for displaying radiographs on television screen and enhancing fine detail in picture. System uses analog-computer circuits to process television signal from low-noise television camera. Enhanced images are displayed in black and white and can be controlled to vary degree of enhancement and magnification of details in either radiographic transparencies or opaque photographs.

  6. Molar axis estimation from computed tomography images.

    PubMed

    Dongxia Zhang; Yangzhou Gan; Zeyang Xia; Xinwen Zhou; Shoubin Liu; Jing Xiong; Guanglin Li

    2016-08-01

    Estimation of tooth axis is needed for some clinical dental treatment. Existing methods require to segment the tooth volume from Computed Tomography (CT) images, and then estimate the axis from the tooth volume. However, they may fail during estimating molar axis due to that the tooth segmentation from CT images is challenging and current segmentation methods may get poor segmentation results especially for these molars with angle which will result in the failure of axis estimation. To resolve this problem, this paper proposes a new method for molar axis estimation from CT images. The key innovation point is that: instead of estimating the 3D axis of each molar from the segmented volume, the method estimates the 3D axis from two projection images. The method includes three steps. (1) The 3D images of each molar are projected to two 2D image planes. (2) The molar contour are segmented and the contour's 2D axis are extracted in each 2D projection image. Principal Component Analysis (PCA) and a modified symmetry axis detection algorithm are employed to extract the 2D axis from the segmented molar contour. (3) A 3D molar axis is obtained by combining the two 2D axes. Experimental results verified that the proposed method was effective to estimate the axis of molar from CT images.

  7. Dual-Axis Rotational Angiography is Safe and Feasible to Detect Coronary Allograft Vasculopathy in Pediatric Heart Transplant Patients: A Single-Center Experience.

    PubMed

    Rios, Rodrigo; Loomba, Rohit S; Foerster, Susan R; Pelech, Andrew N; Gudausky, Todd M

    2016-04-01

    Coronary allograft vasculopathy (CAV) is the leading cause of graft failure in pediatric heart transplant recipients, also adding to mortality in this patient population. Coronary angiography is routinely performed to screen for CAV, with conventional single-plane or bi-plane angiography being utilized. Dual-axis rotational coronary angiography (RA) has been described, mostly in the adult population, and may offer reduction in radiation dose and contrast volume. Experience with this in the pediatric population is limited. This study describes a single-institution experience with RA for screening for CAV in pediatric patients. The catheterization database at our institution was used to identify pediatric heart transplant recipients having undergone RA to screen for CAV. Procedural data including radiation dose, fluoroscopy time, contrast volume, and procedure time were collected for each catheterization. The number of instances in which RA was not successful, ECG changes were present, and CAV was detected were also collected for each catheterization. A total of 97 patients underwent 345 catheterizations utilizing RA. Median radiation dose-area product per kilogram was found to be 341.7 (mGy cm(2)/kg), total air kerma was 126.8 (mGy), procedure time was 69 min, fluoroscopy time was 9.9 min, and contrast volume was 13 ml. A total of 17 (2 %) coronary artery injections out of 690 could not be successfully imaged using RA. A total of 14 patients had CAV noted at any point, 10 of whom had progressive CAV. Electrocardiographic changes were documented in a total of 10 (3 %) RA catheterizations. Procedural characteristics did not differ between serial catheterizations. RA is safe and feasible for CAV screening in pediatric heart transplant recipients while offering coronary imaging in multiple planes compared to conventional angiography.

  8. How Reliable is the Acetabular Cup Position Assessment from Routine Radiographs?

    PubMed Central

    Carvajal Alba, Jaime A.; Vincent, Heather K.; Sodhi, Jagdeep S.; Latta, Loren L.; Parvataneni, Hari K.

    2017-01-01

    Abstract Background: Cup position is crucial for optimal outcomes in total hip arthroplasty. Radiographic assessment of component position is routinely performed in the early postoperative period. Aims: The aims of this study were to determine in a controlled environment if routine radiographic methods accurately and reliably assess the acetabular cup position and to assess if there is a statistical difference related to the rater’s level of training. Methods: A pelvic model was mounted in a spatial frame. An acetabular cup was fixed in different degrees of version and inclination. Standardized radiographs were obtained. Ten observers including five fellowship-trained orthopaedic surgeons and five orthopaedic residents performed a blind assessment of cup position. Inclination was assessed from anteroposterior radiographs of the pelvis and version from cross-table lateral radiographs of the hip. Results: The radiographic methods used showed to be imprecise specially when the cup was positioned at the extremes of version and inclination. An excellent inter-observer reliability (Intra-class coefficient > 0,9) was evidenced. There were no differences related to the level of training of the raters. Conclusions: These widely used radiographic methods should be interpreted cautiously and computed tomography should be utilized in cases when further intervention is contemplated. PMID:28852355

  9. Appearance of the weight-bearing lateral radiograph in retrocalcaneal bursitis

    PubMed Central

    Muller, Bart; Maas, Mario; Sierevelt, Inger N; van Dijk, C Niek

    2010-01-01

    Background and purpose A retrocalcaneal bursitis is caused by repetitive impingement of the bursa between the Achilles tendon and the posterosuperior calcaneus. The bursa is situated in the posteroinferior corner of Kager's triangle (retrocalcaneal recess), which is a radiolucency with sharp borders on the lateral radiograph of the ankle. If there is inflammation, the fluid-filled bursa is less radiolucent, making it difficult to delineate the retrocalcaneal recess. We assessed whether the radiographic appearance of the retrocalcaneal recess on plain digital (filmless) radiographs could be used in the diagnosis of a retrocalcaneal bursitis. Methods Whether or not there was obliteration of the retrocalcaneal recess (yes/no) on 74 digital weight-bearing lateral radiographs of the ankle was independently assessed by 2 observers. The radiographs were from 24 patients (25 heels) with retrocalcaneal bursitis (confirmed on endoscopic calcaneoplasty); the control group consisted of 50 patients (59 heels). Results The sensitivity of the test was 83% for observer 1 and 79% for observer 2. Specificity was 100% and 98%, respectively. The kappa value of the interobserver reliability test was 0.86. For observer 1, intraobserver reliability was 0.96 and for observer 2 it was 0.92. Interpretation On digital weight-bearing lateral radiographs of a retrocalcaneal bursitis, the retrocalcaneal recess has a typical appearance. PMID:20450438

  10. Radiographic measurement of internal organs in Spix's macaws (Cyanopsitta spixii).

    PubMed

    Rettmer, Helen; Deb, Amrita; Watson, Ryan; Hatt, Jean-Michel; Hammer, Sven

    2011-12-01

    Radiology is an important diagnostic instrument in avian medicine, but standard measurement ranges for the objective evaluation of radiographs of birds are rare. To establish radiographic reference ranges for the critically endangered Spix's macaw (Cyanopsitta spixii), we measured radiographic silhouettes of the heart, liver, kidneys, spleen, proventriculus, and keel of the sternum on 29 radiographs taken under standardized conditions in adult and juvenile, clinically healthy birds. Ratios were determined for the proventricular diameter-to-keel height, the width of the heart to the width of the thorax, and for the "hourglass shape" (ratio of the width of the heart to the width of the liver). No significant differences were found between the sexes among the adult birds. Compared with adult birds, juvenile females had a significantly larger heart width (19.8 +/- 1.4 mm versus 21.2 +/- 0.7 mm), ratio of the heart width to the thorax width (0.86 +/- 0.08 versus 0.94 +/- 0.09), and horizontal width of the spleen (7.7 +/- 0.6 mm versus 8.5 +/- 0.4 mm). Results of radiographic measurements in the Spix's macaws were comparable to those published from other psittacine species. These reference ranges will facilitate a more objective radiographic evaluation of captive Spix's macaws.

  11. Ultrasonographic and radiographic findings in 503 cattle with traumatic reticuloperitonitis.

    PubMed

    Braun, Ueli; Gerspach, Christian; Warislohner, Sonja; Nuss, Karl; Ohlerth, Stefanie

    2018-05-26

    This study involved 503 cattle with traumatic reticuloperitonitis (TRP), 494 of which underwent ultrasonographic and 484 radiographic examination of the reticulum. Ultrasonography revealed changes in the reticulum and/or peritoneum suggestive of peritonitis in 403 (83%) cattle, a decrease in the amplitude of reticular contractions in 244 (54%) and reduced or absent reticular motility in 173 (37%). A total of 536 foreign bodies were seen on 465 (96%) radiographs and a magnet was seen on 311 (64%) radiographs. Of the 536 foreign bodies, 300 (56%) were not attached to a magnet and 236 (44%) were attached. Of 300 radiographs showing foreign bodies not attached to a magnet, the foreign body was lying flat on the floor of the reticulum on 98 (18%) radiographs, was at an angle of greater than 30 degrees to the ventral aspect of the reticulum on 54 (10%), had penetrated the dorsal reticular wall on 76 (14%), had perforated the reticulum on 64 (12%) and was completely outside of the reticulum on 8 (1%) radiographs. Ultrasonography provides information about the scale and localisation of inflammatory changes of the peritoneum, and radiography allows the visualisation of ferromagnetic foreign bodies and magnets. Copyright © 2018. Published by Elsevier Ltd.

  12. Stable fixation of an osseointegated implant system for above-the-knee amputees: titel RSA and radiographic evaluation of migration and bone remodeling in 55 cases.

    PubMed

    Nebergall, Audrey; Bragdon, Charles; Antonellis, Anne; Kärrholm, Johan; Brånemark, Rickard; Malchau, Henrik

    2012-04-01

    Rehabilitation of patients with transfemoral amputations is particularly difficult due to problems in using standard socket prostheses. We wanted to assess long-term fixation of the osseointegrated implant system (OPRA) using radiostereometric analysis (RSA) and periprosthetic bone remodeling. 51 patients with transfemoral amputations (55 implants) were enrolled in an RSA study. RSA and plain radiographs were scheduled at 6 months and at 1, 2, 5, 7, and 10 years after surgery. RSA films were analyzed using UmRSA software. Plain radiographs were graded for bone resorption, cancellization, cortical thinning, and trabecular streaming or buttressing in specifically defined zones around the implant. At 5 years, the median (SE) migration of the implant was -0.02 (0.06) mm distally. The rotational movement was 0.42 (0.32) degrees around the longitudinal axis. There was no statistically significant difference in median rotation or migration at any follow-up time. Cancellization of the cortex (plain radiographic grading) appeared in at least 1 zone in over half of the patients at 2 years. However, the prevalence of cancellization had decreased by the 5-year follow-up. The RSA analysis for the OPRA system indicated stable fixation of the implant. The periprosthetic bone remodeling showed similarities with changes seen around uncemented hip stems. The OPRA system is a new and promising approach for addressing the challenges faced by patients with transfemoral amputations.

  13. Cocaine abuse or dependency and other pyschiatric disorders. Madrid study on dual pathology.

    PubMed

    Arias, Francisco; Szerman, Nestor; Vega, Pablo; Mesias, Beatriz; Basurte, Ignacio; Morant, Consuelo; Ochoa, Enriqueta; Poyo, Félix; Babin, Francisco

    2013-01-01

    The main objective of this study was to analyse the cocaine addict subgroup from the Madrid study of prevalence of dual disorders in community mental health and substance misuse services. The sample consisted of 837 outpatients from Madrid, Spain. We compared 488 subjects who had a lifetime diagnosis of cocaine abuse or dependence, and 222 subjects who did not have a cocaine substance use disorder. We used the Mini International Neuropsychiatric Interview to evaluate axis I mental disorders, and the Personality Disorder Questionnaire to evaluate personality disorders. Almost three-quarters (73.4%) of cocaine addicts had a current dual disorder. Most prevalent were mood and anxiety disorders. Almost half (49.6%) had a personality disorder. Most of them (94.9%) had other substance use disorders. Cocaine addicts did not have higher prevalence rates of dual pathology than addicts with no cocaine abuse or dependence. Cocaine addicts were associated to a diagnosis of antisocial personality disorder, agoraphobia, and post-traumatic stress disorder, and they had an early age of onset of alcohol and cannabis use. Dual pathology is no higher in cocaine addicts in treatment than in addicts who do not use cocaine, however cocaine addicts started other drugs earlier, and were associated with specific mental disorders. Copyright © 2012 SEP y SEPB. Published by Elsevier Espana. All rights reserved.

  14. 10 CFR Appendix A to Part 34 - Radiographer Certification

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Pt. 34, App. A Appendix A to Part 34—Radiographer Certification I... of industrial radiography; 2. Make its membership available to the general public nationwide that is...

  15. 10 CFR Appendix A to Part 34 - Radiographer Certification

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Pt. 34, App. A Appendix A to Part 34—Radiographer Certification I... of industrial radiography; 2. Make its membership available to the general public nationwide that is...

  16. 10 CFR Appendix A to Part 34 - Radiographer Certification

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Pt. 34, App. A Appendix A to Part 34—Radiographer Certification I... of industrial radiography; 2. Make its membership available to the general public nationwide that is...

  17. 10 CFR Appendix A to Part 34 - Radiographer Certification

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Pt. 34, App. A Appendix A to Part 34—Radiographer Certification I... of industrial radiography; 2. Make its membership available to the general public nationwide that is...

  18. Acceleration feedback of a current-following synchronized control algorithm for telescope elevation axis

    NASA Astrophysics Data System (ADS)

    Tang, Tao; Zhang, Tong; Du, Jun-Feng; Ren, Ge; Tian, Jing

    2016-11-01

    This paper proposes a dual-motor configuration to enhance closed-loop performance of a telescope control system. Two identical motors are mounted on each side of a U-type frame to drive the telescope elevation axis instead of a single motor drive, which is usually used in a classical design. This new configuration and mechanism can reduce the motor to half the size used in the former design, and it also provides some other advantages. A master-slave current control mode is employed to synchronize the two motors. Acceleration feedback control is utilized to further enhance the servo performance. Extensive experiments are used to validate the effectiveness of the proposed control algorithm in synchronization, disturbance attenuation and low-velocity tracking.

  19. Design of dual energy x-ray detector for conveyor belt with steel wire ropes

    NASA Astrophysics Data System (ADS)

    Dai, Yue; Miao, Changyun; Rong, Feng

    2009-07-01

    A dual energy X-ray detector for conveyor belt with steel wire ropes is researched in the paper. Conveyor belt with steel wire ropes is one of primary transfer equipments in modern production. The traditional test methods like electromagnetic induction principle could not display inner image of steel wire ropes directly. So X-ray detection technology has used to detect the conveyor belt. However the image was not so clear by the interference of the rubber belt. Therefore, the dualenergy X-ray detection technology with subtraction method is developed to numerically remove the rubber belt from radiograph, thus improving the definition of the ropes image. The purpose of this research is to design a dual energy Xray detector that could make the operator easier to found the faulty of the belt. This detection system is composed of Xray source, detector controlled by FPGA chip, PC for running image processing system and so on. With the result of the simulating, this design really improved the capability of the staff to test the conveyor belt.

  20. The quality of emergency room radiograph interpretations.

    PubMed

    McLain, P L; Kirkwood, C R

    1985-05-01

    Primary care physicians often make patient management decisions based in part on their own interpretations of radiographs. This important area of clinical decision making has not been previously analyzed in the literature. In this series of 294 consecutive radiographs from rural practice, interpretative disagreement between primary care providers and backup radiologists occurred 9.2 percent of the time, a discordance rate similar to that seen among radiologists in other studies. Although a majority of the films for which interpretative disagreement occurred had potential implications for influencing patient management, in only seven cases did actual case management vary from appropriate norms. Follow-up of cases where interpretative disagreement occurred revealed that in only two cases did unsatisfactory outcomes occur. Primary care physicians can provide high-quality radiographic interpretations that, when coupled with clinical information, yield extremely low rates of error or potential for poor patient outcomes.

  1. Multi-Axis Test Facility

    NASA Image and Video Library

    1959-11-01

    Multi-Axis Test Facility, Space Progress Report, November 1, 1959: The Multi Axis Space Test Inertia Facility [MASTIF], informally referred to as the Gimbal Rig, was installed inside the Altitude Wind Tunnel. The rig, which spun on three axis simultaneously, was used to train the Mercury astronauts on how to bring a spinning spacecraft under control and to determine the effects of rapid spinning on the astronaut's eyesight and psyche. Small gaseous nitrogen jets were operated by the pilot to gain control of the rig after it had been set in motion. Part 1 shows pilot Joe Algranti in the rig as it rotates over one, two, and three axis. It also has overall views of the test set-up with researchers and technicians on the test platform. Part 2 shows Algranti being secured in the rig prior to the test. The rig is set in motion and the pilot slowly brings it under control. The Mercury astronauts trained on the MASTIF in early spring of 1960.

  2. Radiographic anatomy of the foot and ankle-part 2: the greater tarsus.

    PubMed

    Christman, Robert A

    2014-01-01

    Normal radiographic anatomy of the foot and ankle, aside from my previous work, has been addressed only superficially or sparingly in the medical literature. This project correlates detailed radiographic anatomy of the entire adult foot and ankle (two-dimensional) to osteology (three-dimensional). Each bone's position was determined after meticulous examination and correlation to an articulated skeleton relative to the image receptor and direction of the x-ray beam, with correlation to the radiograph for confirmation. Images of each foot and distal leg bone ("front" and "back" perspectives) are presented alongside a corresponding radiographic image for comparison. The normal gross and radiographic anatomy is correlated and described for each radiographic positioning technique. Foundational knowledge is provided that future researchers can use as a baseline ("normal") and that students and practitioners can use for comparison when interpreting radiographs and distinguishing abnormal findings. The results of the original project, owing to its broad scope, have been divided into five parts: the lower leg, the greater tarsus (the focus of this article), the lesser tarsus, the metatarsals, and the phalanges.

  3. Improving the Quality of Radiographs in Neonatal Intensive Care Unit Utilizing Educational Interventions.

    PubMed

    Gupta, Ashish O; Rorke, Jeanne; Abubakar, Kabir

    2015-08-01

    We aimed to develop an educational tool to improve the radiograph quality, sustain this improvement overtime, and reduce the number of repeat radiographs. A three phase quality control study was conducted at a tertiary care NICU. A retrospective data collection (phase1) revealed suboptimal radiograph quality and led to an educational intervention and development of X-ray preparation checklist (primary intervention), followed by a prospective data collection for 4 months (phase 2). At the end of phase 2, interim analysis revealed a gradual decline in radiograph quality, which prompted a more comprehensive educational session with constructive feedback to the NICU staff (secondary intervention), followed by another data collection for 6 months (phase 3). There was a significant improvement in the quality of radiographs obtained after primary educational intervention (phase 2) compared with phase 1 (p < 0.001). During interim analysis after phase 2, radiograph quality declined but still remained significantly better than phase 1. Secondary intervention resulted in significant improvement in radiograph quality to > 95% in all domains of image quality. No radiographs were repeated in phase 3, compared with 5.8% (16/277) in phase 1. A structured, collaborated educational intervention successfully improves the radiograph quality and decreases the need for repeat radiographs and radiation exposure in the neonates. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  4. Design of Off-Axis PIAACMC Mirrors

    NASA Technical Reports Server (NTRS)

    Pluzhnik, Eugene; Guyon, Olivier; Belikov, Ruslan; Kern, Brian; Bendek, Eduardo

    2015-01-01

    The Phase-Induced Amplitude Apodization Complex Mask Coronagraph (PIAACMC) provides an efficient way to control diffraction propagation effects caused by the central obstruction/segmented mirrors of the telescope. PIAACMC can be optimized in a way that takes into account both chromatic diffraction effects caused by the telescope obstructed aperture and tip/tilt sensitivity of the coronagraph. As a result, unlike classic PIAA, the PIAACMC mirror shapes are often slightly asymmetric even for an on-axis configuration and require more care in calculating off-axis shapes when an off-axis configuration is preferred. A method to design off-axis PIAA mirror shapes given an on-axis mirror design is presented. The algorithm is based on geometrical ray tracing and is able to calculate off-axis PIAA mirror shapes for an arbitrary geometry of the input and output beams. The method is demonstrated using the third generation PIAACMC design for WFIRST-AFTA (Wide Field Infrared Survey Telescope-Astrophysics Focused Telescope Assets) telescope. Geometrical optics design issues related to the off-axis diffraction propagation effects are also discussed.

  5. Integration of radiographic images with an electronic medical record.

    PubMed Central

    Overhage, J. M.; Aisen, A.; Barnes, M.; Tucker, M.; McDonald, C. J.

    2001-01-01

    Radiographic images are important and expensive diagnostic tests. However, the provider caring for the patient often does not review the images directly due to time constraints. Institutions can use picture archiving and communications systems to make images more available to the provider, but this may not be the best solution. We integrated radiographic image review into the Regenstrief Medical Record System in order to address this problem. To achieve adequate performance, we store JPEG compressed images directly in the RMRS. Currently, physicians review about 5% of all radiographic studies using the RMRS image review function. PMID:11825241

  6. A new technique for radiographic measurement of acetabular cup orientation.

    PubMed

    Derbyshire, Brian; Diggle, Peter J; Ingham, Christopher J; Macnair, Rory; Wimhurst, James; Jones, Henry Wynn

    2014-02-01

    Accurate radiographic measurement of acetabular cup orientation is required in order to assess susceptibility to impingement, dislocation, and edge loading wear. In this study, the accuracy and precision of a new radiographic cup orientation measurement system were assessed and compared to those of two commercially available systems. Two types of resurfacing hip prostheses and an uncemented prosthesis were assessed. Radiographic images of each prosthesis were created with the cup set at different, known angles of version and inclination in a measurement jig. The new system was the most accurate and precise and could repeatedly measure version and inclination to within a fraction of a degree. In addition it has a facility to distinguish cup retroversion from anteversion on anteroposterior radiographs. © 2013.

  7. Radiographic Diagnosis of Pincer-Type Femoroacetabular Impingement: A Systematic Review.

    PubMed

    Rhee, Chanseok; Le Francois, Tina; Byrd, J W Thomas; Glazebrook, Mark; Wong, Ivan

    2017-05-01

    Femoroacetabular impingement (FAI) is a well-recognized condition that causes hip pain and can lead to early osteoarthritis if not managed properly. With the increasing awareness and efficacy of operative treatments for pincer-type FAI, there is a need for consensus on the standardized radiographic diagnosis. To perform a systematic review of the evidence regarding imaging modalities and radiographic signs for diagnosing pincer-type FAI. Systematic review; Level of evidence, 4. A literature review was performed in 2016 using the Cochrane, PubMed, and Embase search engines. All articles focusing on a radiographic diagnosis of pincer-type FAI were reviewed. Each of the included 44 articles was assigned the appropriate level of evidence, and the particular radiographic marker and/or type of imaging were also summarized. There were 44 studies included in the final review. Most of the articles were level 4 evidence (26 articles), and there were 12 level 3 and 6 level 2 articles. The crossover sign was the most commonly used radiographic sign (27/44) followed by the lateral center-edge angle (22/44). Anteroposterior (AP) pelvis plain radiographs were the most commonly used imaging modality (33 studies). Poor-quality evidence exists in support of most currently used radiographic markers, including the crossover sign, lateral center-edge angle, posterior wall sign, ischial spine sign, coxa profunda, acetabular protrusion, and acetabular index. There is poor-quality conflicting evidence regarding the use of the herniation pit to diagnose pincer-type FAI. Some novel measurements, such as β-angle, acetabular roof ratio, and acetabular retroversion index, have been proposed, but they also lack support from the literature. No strong evidence exists to support a single best set of current radiographic markers for the diagnosis of pincer-type FAI, largely due to the lack of better quality trials (levels 1 and 2) that compare conventional radiographic findings with the gold

  8. Radiologists remember mountains better than radiographs, or do they?

    PubMed

    Evans, Karla K; Marom, Edith M; Godoy, Myrna C B; Palacio, Diana; Sagebiel, Tara; Cuellar, Sonia Betancourt; McEntee, Mark; Tian, Charles; Brennan, Patrick C; Haygood, Tamara Miner

    2016-01-01

    Expertise with encoding material has been shown to aid long-term memory for that material. It is not clear how relevant this expertise is for image memorability (e.g., radiologists' memory for radiographs), and how robust over time. In two studies, we tested scene memory using a standard long-term memory paradigm. One compared the performance of radiologists to naïve observers on two image sets, chest radiographs and everyday scenes, and the other radiologists' memory with immediate as opposed to delayed recognition tests using musculoskeletal radiographs and forest scenes. Radiologists' memory was better than novices for images of expertise but no different for everyday scenes. With the heterogeneity of image sets equated, radiologists' expertise with radiographs afforded them better memory for the musculoskeletal radiographs than forest scenes. Enhanced memory for images of expertise disappeared over time, resulting in chance level performance for both image sets after weeks of delay. Expertise with the material is important for visual memorability but not to the same extent as idiosyncratic detail and variability of the image set. Similar memory decline with time for images of expertise as for everyday scenes further suggests that extended familiarity with an image is not a robust factor for visual memorability.

  9. Radiologists remember mountains better than radiographs, or do they?

    PubMed Central

    Evans, Karla K.; Marom, Edith M.; Godoy, Myrna C. B.; Palacio, Diana; Sagebiel, Tara; Cuellar, Sonia Betancourt; McEntee, Mark; Tian, Charles; Brennan, Patrick C.; Haygood, Tamara Miner

    2015-01-01

    Abstract. Expertise with encoding material has been shown to aid long-term memory for that material. It is not clear how relevant this expertise is for image memorability (e.g., radiologists’ memory for radiographs), and how robust over time. In two studies, we tested scene memory using a standard long-term memory paradigm. One compared the performance of radiologists to naïve observers on two image sets, chest radiographs and everyday scenes, and the other radiologists’ memory with immediate as opposed to delayed recognition tests using musculoskeletal radiographs and forest scenes. Radiologists’ memory was better than novices for images of expertise but no different for everyday scenes. With the heterogeneity of image sets equated, radiologists’ expertise with radiographs afforded them better memory for the musculoskeletal radiographs than forest scenes. Enhanced memory for images of expertise disappeared over time, resulting in chance level performance for both image sets after weeks of delay. Expertise with the material is important for visual memorability but not to the same extent as idiosyncratic detail and variability of the image set. Similar memory decline with time for images of expertise as for everyday scenes further suggests that extended familiarity with an image is not a robust factor for visual memorability. PMID:26870748

  10. Lung nodule detection by microdose CT versus chest radiography (standard and dual-energy subtracted).

    PubMed

    Ebner, Lukas; Bütikofer, Yanik; Ott, Daniel; Huber, Adrian; Landau, Julia; Roos, Justus E; Heverhagen, Johannes T; Christe, Andreas

    2015-04-01

    The purpose of this study was to investigate the feasibility of microdose CT using a comparable dose as for conventional chest radiographs in two planes including dual-energy subtraction for lung nodule assessment. We investigated 65 chest phantoms with 141 lung nodules, using an anthropomorphic chest phantom with artificial lung nodules. Microdose CT parameters were 80 kV and 6 mAs, with pitch of 2.2. Iterative reconstruction algorithms and an integrated circuit detector system (Stellar, Siemens Healthcare) were applied for maximum dose reduction. Maximum intensity projections (MIPs) were reconstructed. Chest radiographs were acquired in two projections with bone suppression. Four blinded radiologists interpreted the images in random order. A soft-tissue CT kernel (I30f) delivered better sensitivities in a pilot study than a hard kernel (I70f), with respective mean (SD) sensitivities of 91.1%±2.2% versus 85.6%±5.6% (p=0.041). Nodule size was measured accurately for all kernels. Mean clustered nodule sensitivity with chest radiography was 45.7%±8.1% (with bone suppression, 46.1%±8%; p=0.94); for microdose CT, nodule sensitivity was 83.6%±9% without MIP (with additional MIP, 92.5%±6%; p<10(-3)). Individual sensitivities of microdose CT for readers 1, 2, 3, and 4 were 84.3%, 90.7%, 68.6%, and 45.0%, respectively. Sensitivities with chest radiography for readers 1, 2, 3, and 4 were 42.9%, 58.6%, 36.4%, and 90.7%, respectively. In the per-phantom analysis, respective sensitivities of microdose CT versus chest radiography were 96.2% and 75% (p<10(-6)). The effective dose for chest radiography including dual-energy subtraction was 0.242 mSv; for microdose CT, the applied dose was 0.1323 mSv. Microdose CT is better than the combination of chest radiography and dual-energy subtraction for the detection of solid nodules between 5 and 12 mm at a lower dose level of 0.13 mSv. Soft-tissue kernels allow better sensitivities. These preliminary results indicate that

  11. Dual Credit/Dual Enrollment and Data Driven Policy Implementation

    ERIC Educational Resources Information Center

    Lichtenberger, Eric; Witt, M. Allison; Blankenberger, Bob; Franklin, Doug

    2014-01-01

    The use of dual credit has been expanding rapidly. Dual credit is a college course taken by a high school student for which both college and high school credit is given. Previous studies provided limited quantitative evidence that dual credit/dual enrollment is directly connected to positive student outcomes. In this study, predictive statistics…

  12. Method for minimizing the radiation exposure from scoliosis radiographs. [X ray

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    De Smet, A.A.; Fritz, S.L.; Asher, M.A.

    1981-01-01

    The radiation exposure resulting from standard scoliosis radiographs was determined for eighteen adolescent girls. The risk of inducing breast cancer was estimated from the skin-exposure doses. The average skin exposure to the breasts was 59.6 millirads (0.59 mGy) for the anteroposterior radiograph. Assuming a total of twenty-two anteroposterior radiographs during a course of treatment, the cumulative exposure would result in a 1.35% relative increase in the risk of development of breast cancer. By utilizing collimation of the x-ray beam and proper selection of grids, films, and screens, the radiation risk of scoliosis radiographs is minimized.

  13. Aeroelastically coupled blades for vertical axis wind turbines

    DOEpatents

    Paquette, Joshua; Barone, Matthew F.

    2016-02-23

    Various technologies described herein pertain to a vertical axis wind turbine blade configured to rotate about a rotation axis. The vertical axis wind turbine blade includes at least an attachment segment, a rear swept segment, and optionally, a forward swept segment. The attachment segment is contiguous with the forward swept segment, and the forward swept segment is contiguous with the rear swept segment. The attachment segment includes a first portion of a centroid axis, the forward swept segment includes a second portion of the centroid axis, and the rear swept segment includes a third portion of the centroid axis. The second portion of the centroid axis is angularly displaced ahead of the first portion of the centroid axis and the third portion of the centroid axis is angularly displaced behind the first portion of the centroid axis in the direction of rotation about the rotation axis.

  14. Personalized models of bones based on radiographic photogrammetry.

    PubMed

    Berthonnaud, E; Hilmi, R; Dimnet, J

    2009-07-01

    The radiographic photogrammetry is applied, for locating anatomical landmarks in space, from their two projected images. The goal of this paper is to define a personalized geometric model of bones, based uniquely on photogrammetric reconstructions. The personalized models of bones are obtained from two successive steps: their functional frameworks are first determined experimentally, then, the 3D bone representation results from modeling techniques. Each bone functional framework is issued from direct measurements upon two radiographic images. These images may be obtained using either perpendicular (spine and sacrum) or oblique incidences (pelvis and lower limb). Frameworks link together their functional axes and punctual landmarks. Each global bone volume is decomposed in several elementary components. Each volumic component is represented by simple geometric shapes. Volumic shapes are articulated to the patient's bone structure. The volumic personalization is obtained by best fitting the geometric model projections to their real images, using adjustable articulations. Examples are presented to illustrating the technique of personalization of bone volumes, directly issued from the treatment of only two radiographic images. The chosen techniques for treating data are then discussed. The 3D representation of bones completes, for clinical users, the information brought by radiographic images.

  15. Inadequate pelvic radiographs: implications of not getting it right the first time.

    PubMed

    Parker, S; Nagra, N S; Kulkarni, K; Pegrum, J; Barry, S; Hughes, R; Ghani, Y

    2017-09-01

    Introduction Pelvic radiography is a frequent investigation. European guidelines aim to ensure appropriate use and adequate quality. When initial images are inadequate, repeat radiographs are often required, which may have significant patient safety and economic implications. Objectives The study aimed to assess the adequacy of pelvic imaging across three orthopaedic centres, to identify causes for inadequate imaging and to establish the cost of inadequate imaging from financial and patient safety perspectives. Methods Pelvic radiographs were identified on Picture Archiving and Communication System software at three UK hospitals. Radiographs were assessed against European guidelines and indications for repeat imaging were analysed. Results A total of 1,531 sequential pelvic radiographs were reviewed. The mean age of patients was 60 years (range 5 months to 101 years). Of this total, 51.9% of images were suboptimal, with no significant difference across the three hospitals (P > 0.05). Hospital 3 repeated radiographs in 6.3% of cases, compare with 18.1% and 19.7% at hospitals 1 and 2, respectively (P > 0.05). Hospital 3 identified pathology missed on the initial radiograph in 1% of cases, compared with 5.4% and 5.5% at hospitals 1 and 2, respectively (P > 0.05). Out-of-hours imaging is associated with a higher rate of suboptimal quality (69.1%) compared with normal working hours (51.3%; P = 0.006). Adequacy rates vary with age (χ 2 = 43.62, P < 0.001). Risk of having a suboptimal radiograph increases above the age of 60-years (χ 2 = 4.45, P < 0.05). The annual cost of repeat radiographs was £56,200 per hospital. Discussion and conclusion High rates of pelvic radiograph inadequacy can lead to missed pathology and the requirement for repeat imaging, which has significant patient safety and financial implications. Risk factors for inadequate radiographs include older patients and those having out-of-hours imaging.

  16. Quantitative analysis of the plain radiographic appearance of nonossifying fibroma.

    PubMed

    Friedland, J A; Reinus, W R; Fisher, A J; Wilson, A J

    1995-08-01

    To quantitate radiographic features that distinguish the plain radiographic appearance of nonossifying fibroma (NOF) from other solitary lesions of bone. Seven hundred nine cases of focal bone lesions, including 34 NOFs, were analyzed according to demographic, anatomic, and plain radiographic features. Vector analysis of groups of features was performed to determine those that are most sensitive and specific for the appearance of NOF in contrast to other lesions in the data base. The radiographic appearance of NOFs was most consistently a medullary based (97%), lytic lesion (100%) with geographic bone destruction (100%), marginal sclerosis (97%), and well-defined edges (94%). A statistically significant number of lesions were located in the distal aspect of long bones. Unicameral bone cyst shared the most radiographic features with the NOF. Vector analysis showed a large degree of overlap between NOF and other lesions such as aneurysmal bone cyst, chondromyxoid fibroma, and eosinophilic granuloma. The description that optimized sensitivity and prevalence for detection of NOF is a medullary based, ovoid lesion in the distal or proximal portions of a long bone with well-defined edges, a partial or complete rind of sclerosis, and absence of fallen fragment, periosteal reaction, and cortical disruption. The radiographic appearance of NOF is relatively nonspecific but, using vector analysis, can be better elucidated over current textbook descriptions.

  17. Segmentation and determination of joint space width in foot radiographs

    NASA Astrophysics Data System (ADS)

    Schenk, O.; de Muinck Keizer, D. M.; Bernelot Moens, H. J.; Slump, C. H.

    2016-03-01

    Joint damage in rheumatoid arthritis is frequently assessed using radiographs of hands and feet. Evaluation includes measurements of the joint space width (JSW) and detection of erosions. Current visual scoring methods are timeconsuming and subject to inter- and intra-observer variability. Automated measurement methods avoid these limitations and have been fairly successful in hand radiographs. This contribution aims at foot radiographs. Starting from an earlier proposed automated segmentation method we have developed a novel model based image analysis algorithm for JSW measurements. This method uses active appearance and active shape models to identify individual bones. The model compiles ten submodels, each representing a specific bone of the foot (metatarsals 1-5, proximal phalanges 1-5). We have performed segmentation experiments using 24 foot radiographs, randomly selected from a large database from the rheumatology department of a local hospital: 10 for training and 14 for testing. Segmentation was considered successful if the joint locations are correctly determined. Segmentation was successful in only 14%. To improve results a step-by-step analysis will be performed. We performed JSW measurements on 14 randomly selected radiographs. JSW was successfully measured in 75%, mean and standard deviation are 2.30+/-0.36mm. This is a first step towards automated determination of progression of RA and therapy response in feet using radiographs.

  18. Single-axis gyroscopic motion with uncertain angular velocity about spin axis

    NASA Technical Reports Server (NTRS)

    Singh, S. N.

    1977-01-01

    A differential game approach is presented for studying the response of a gyro by treating the controlled angular velocity about the input axis as the evader, and the bounded but uncertain angular velocity about the spin axis as the pursuer. When the uncertain angular velocity about the spin axis desires to force the gyro to saturation a differential game problem with two terminal surfaces results, whereas when the evader desires to attain the equilibrium state the usual game with single terminal manifold arises. A barrier, delineating the capture zone (CZ) in which the gyro can attain saturation and the escape zone (EZ) in which the evader avoids saturation is obtained. The CZ is further delineated into two subregions such that the states in each subregion can be forced on a definite target manifold. The application of the game theoretic approach to Control Moment Gyro is briefly discussed.

  19. An in-vitro comparison of the radiographic and actual gutta-percha terminus.

    PubMed

    Namazikhah, M S; Ghiai, M; Parkin, M J; Puccinelli, L

    2000-06-01

    The purpose of this study was to investigate the difference between the radiographic gutta-percha terminus and the actual gutta-percha terminus of human molars by comparing radiographic obturation results with actual obturation results. Forty maxillary palatal roots and 50 mandibular distal roots were randomly selected from a population of 540. They were then mounted in stone and radiographed. Conventional endodontic therapy was completed using stainless-steel K files and lateral condensation. Each radiographic gutta-percha terminus was evaluated under 4.5x magnification by three examiners following the completion of root canal therapy. These results were recorded. Each tooth was then removed from its mounting, and the actual gutta-percha terminus was evaluated under 4.5x magnification. These results were recorded and compared to the radiographic gutta-percha terminus results. In all 90 teeth examined, the actual gutta-percha terminus was equal to or longer than the radiographic gutta-percha terminus. In the 50 mandibular distal roots, the actual gutta-percha terminus averaged 0.645 mm longer than the radiographic gutta-percha terminus. In the 40 maxillary palatal roots, this difference measured 0.6375 mm.

  20. Effectiveness Of Plain Shoulder Radiograph In Detecting Degenerate Rotator Cuff Tears.

    PubMed

    Hussain, Adnan; Muzzammil, Muhammad; Butt, Faisal; Valsamis, Epaminondas Markos; Dwyer, Amitabh J

    2018-01-01

    Studies have demonstrated radiographic findings of sclerosis and cortical irregularity at the greater tuberosity can suggest a rotator cuff tear. Plain radiographs are the most easily attainable first-line investigations in evaluating shoulder injuries. This study determines the effectiveness in predicting degenerate rotator cuff tears by detecting radiographic changes on shoulder x-rays. Retrospective cross-sectional study with a consecutive series of patients conducted in Hinchingbrooke Hospital, Huntingdon, United Kingdom from January 2015 to June 2017. Anteroposterior shoulder radiographs of 150 symptomatic patients who underwent shoulder arthroscopy were independently analysed by surgeons who were blinded from the arthroscopic results. Patients aged fewer than 30 and over 70 years were excluded. Patients with advanced osteoarthritis and cuff tear arthropathy evident on x-rays were also excluded. Sixty-five patients included in the study had rotator cuff tears on arthroscopy. Radiographic changes were correlated with arthroscopic findings to determine this test's ability to predict degenerate rotator cuff tears. When both cortical irregularity and sclerosis were present on the plain radiograph, these signs had a sensitivity of 78.8% [95% CI 65.7, 87.8%] and specificity 77.4% [95% CI 67.2, 85.0%] with a positive predictive value of 68.3%, using contingency table analysis. The presence of cortical irregularity was found to be a better predictor of a tear as compared to sclerosis. This study concludes that plain radiograph are good modality for initial evaluation of rotator cuff tears and detecting when both cortical irregularity and sclerosis. Consideration of these radiographic findings serves as a useful adjunct in diagnostic workup and can guide subsequent investigations and treatment when evaluating rotator cuff tears of the shoulder.

  1. Are reporting radiographers fulfilling the role of advanced practitioner?

    PubMed

    Milner, R C; Snaith, B

    2017-02-01

    Advanced practice roles are emerging in all disciplines at a rapid pace and reporting radiographers are ideally placed to work at such level. Advanced practitioners should demonstrate expert practice and show progression into three other areas of higher level practice. Most existing literature has focussed on the image interpretation aspect of the role, however there is little evidence that plain film reporting radiographers are undertaking activities beyond image interpretation and fulfilling the role of advanced practitioner. Letters were posted to every acute NHS trust in the UK, inviting reporting radiographers to complete an online survey. Both quantitative and qualitative information was sought regarding demographics and roles supplementary to reporting. A total of 205 responses were analysed; 83.3% of reporting radiographers describe themselves as advanced practitioner, however significantly less are showing progression into the four core functions of higher level practice. A total of 97.0% undertake expert practice, 54.7% have a leadership role, 19.8% provide expert lectures and 71.1% have roles encompassing service development or research, though most of these fall into the service development category. 34.5% felt that they were aware of the differences between extended and advanced practice though much less (9.3%) could correctly articulate the difference. Few individuals are aware of the difference between extended and advanced practice. Though the majority of plain film reporting radiographers identify themselves as advanced practitioners, significantly less evidence all four core functions of higher level practice. The number of individuals undertaking research and providing expert-level education is low. Copyright © 2016 The College of Radiographers. Published by Elsevier Ltd. All rights reserved.

  2. Radiographic Evidence of Hip Microinstability in Elite Ballet.

    PubMed

    Mitchell, Ronald J; Gerrie, Brayden J; McCulloch, Patrick C; Murphy, Andrew J; Varner, Kevin E; Lintner, David M; Harris, Joshua D

    2016-06-01

    To determine prevalence, magnitude, and predisposing radiographic features of hip subluxation in elite ballet dancers. A cross-sectional investigation of professional male and female ballet dancers was performed using 5 plain radiographs. A "splits" anteroposterior (AP) radiograph was performed with legs abducted parallel to the trunk in the coronal plane (splits position; grand écart facial). Hip center position (HCP) was measured on standing AP pelvis and AP pelvis splits views and the difference calculated (subluxation distance) to determine prevalence and magnitude of femoral head subluxation. Student t test compared HCP on AP pelvis and splits radiographs. Pearson correlations were used to correlate splits HCP with radiographic measures of femoroacetabular impingement and dysplasia. Analyzing 47 dancers (21 men, 26 women; 23.8 ± 5.4 years), mean HCP on standing AP pelvis was 9.39 ± 3.33 mm versus 10.8 ± 2.92 mm on splits radiograph, with mean subluxation distance of 1.41 mm (P = .035). Forty-two dancers' femoral heads translated laterally with splits positioning, and 17 dancers (36%) exhibited a "vacuum sign" (bilateral in 71% of subjects with at least 1 hip vacuum sign). There was strong positive correlation (r = 0.461, P = .001) with splits HCP and alpha angle (Dunn 45°), and moderate negative correlation (r = -0.332, P = .022) with subluxation distance and neck-shaft angle. In men, splits HCP increased as lateral center edge angle (CEA) decreased (r = -0.437, P = .047), as anterior CEA decreased (r = -0.482, P = .027), as Tönnis angle increased (r = 0.656, P = .001), and as femoral head extrusion index increased (r = 0.511, P = .018). In women, there was moderate negative correlation (r = -0.389, P = .049) with subluxation distance and neck-shaft angle. Hip subluxation occurs during splits in most professional ballet dancers, with a significantly greater magnitude of subluxation in women than men. Subluxation magnitude

  3. Two new methods to increase the contrast of track-etch neutron radiographs

    NASA Technical Reports Server (NTRS)

    Morley, J.

    1971-01-01

    Methods for increasing the (optical density span) of radiographs were evaluated. In one method, fluorescent dye was deposited in the tracks of the radiograph. The radiograph was then examined under ultraviolet light. The second method was a crossed Polaroid filter technique. The radiograph was placed between the filters and then illuminated with a diffuse white-light source. An increase in the optical density span from .10 to .37 was obtained with the dye method. With the Polaroid method, the increase obtained was from .10 to 2.4.

  4. Navicular subluxation as a radiographic finding in Charcot neuroarthropathy.

    PubMed

    Estess, Allyson; Marquand, Nicole; Charlton, Timothy P; Thordarson, David B

    2013-11-01

    Treatment of patients with Charcot midfoot destruction is a difficult and increasingly common clinical problem. The pathoanatomical features of Charcot neuropathy have been evaluated in only a few studies. This study evaluated whether medial navicular subluxation (adduction of the navicular on the talus) is a radiographic finding present in patients with Charcot neuroarthropathy. A retrospective review of 143 consecutive patients diagnosed with Charcot arthropathy of the foot from January 2004 to May 2011 was performed. Patients were identified based on a clinical diagnosis code 713.5 during an outpatient clinic visit with 2 surgeons at a single institution. After exclusion criteria were applied, a series of radiographs of 50 feet in 40 patients were compared with radiographs from an age-matched control group. Radiographic data including talonavicular coverage angle and talonavicular uncoverage percentage were collected. The mean talonavicular coverage angle of the Charcot arthropathy group was 1.5 degrees and of the control group 12.1 degrees (P < .05). The talonavicular uncoverage value for the Charcot arthropathy group was 12.2% and for the control group 22.0% (P < .001). Medial navicular subluxation was a radiographic finding that was more commonly present in patients with Charcot arthropathy than in a matched control group. It is theorized that this finding is attributable to an unopposed pull of the posterior tibial tendon on the destabilized navicular. Level IV, retrospective case series.

  5. Film and digital periapical radiographs for the measurement of apical root shortening.

    PubMed

    El-Angbawi, Ahmed M F; McIntyre, Grant T; Bearn, David R; Thomson, Donald J

    2012-12-01

    The aim of this study was to compare the accuracy and agreement of scanned film and digital periapical radiographs for the measurement of apical root shortening. Twenty-four film and digital [phosphor plate sensor (PPS)] periapical radiographs were taken using the long-cone paralleling technique for six extracted teeth before and after 1mm of apical root trimming. All teeth were mounted using a typodont and the radiographs were recorded using a film holder and polysiloxane occlusal index for each tooth to ensure standardization during the different radiographic exposures. The film radiographs were scanned and the tooth length measurements for the scanned film and digital (PPS) images were calculated using Image-J-Link 1.4 software (http://rebweb.nih.gov/ij/index.html) for the two groups. The accuracy and agreement among the tooth length measurements from each group and the true tooth length measurements were calculated using intra-class correlation (ICC) tests and Bland and Altman plots. A high level of agreement was found between the true tooth length measurements and the scanned film measurements (ICC=0.979, limit of agreement 0.579 to -0.565) and the digital (PPS) radiograph measurements (ICC= 0.979, limit of agreement 0.596 to -0.763). Moreover, a high level of agreement was found between the scanned film and digital (PPS) radiographs for the measurement of tooth length ICC=0.991, limit of agreement 0.411-0.231. Film and digital (PPS) periapical radiographs are accurate methods for measuring apical root shortening with a high level of agreement. Key words:Root shortening, measurement, periapical radiographs, film, digital.

  6. Patient-specific instrumentation does not improve radiographic alignment or clinical outcomes after total knee arthroplasty.

    PubMed

    Huijbregts, Henricus J T A M; Khan, Riaz J K; Sorensen, Emma; Fick, Daniel P; Haebich, Samantha

    2016-08-01

    Background and purpose - Patient-specific instrumentation (PSI) for total knee arthroplasty (TKA) has been introduced to improve alignment and reduce outliers, increase efficiency, and reduce operation time. In order to improve our understanding of the outcomes of patient-specific instrumentation, we conducted a meta-analysis. Patients and methods - We identified randomized and quasi-randomized controlled trials (RCTs) comparing patient-specific and conventional instrumentation in TKA. Weighted mean differences and risk ratios were determined for radiographic accuracy, operation time, hospital stay, blood loss, number of surgical trays required, and patient-reported outcome measures. Results - 21 RCTs involving 1,587 TKAs were included. Patient-specific instrumentation resulted in slightly more accurate hip-knee-ankle axis (0.3°), coronal femoral alignment (0.3°, femoral flexion (0.9°), tibial slope (0.7°), and femoral component rotation (0.5°). The risk ratio of a coronal plane outlier (> 3° deviation of chosen target) for the tibial component was statistically significantly increased in the PSI group (RR =1.64). No significance was found for other radiographic measures. Operation time, blood loss, and transfusion rate were similar. Hospital stay was significantly shortened, by approximately 8 h, and the number of surgical trays used decreased by 4 in the PSI group. Knee Society scores and Oxford knee scores were similar. Interpretation - Patient-specific instrumentation does not result in clinically meaningful improvement in alignment, fewer outliers, or better early patient-reported outcome measures. Efficiency is improved by reducing the number of trays used, but PSI does not reduce operation time.

  7. Radiographers' perceptions of their professional rights in diagnostic radiography: a qualitative interview study.

    PubMed

    Matilainen, Kati; Ahonen, Sanna-Mari; Kankkunen, Päivi; Kangasniemi, Mari

    2017-03-01

    Considering the ethics of each profession is important as inter-professional collaboration increases. Professional ethics creates a basis for radiographers' work, as it includes values and principles, together with rights and duties that guide and support professionals. However, little is known about radiographers' rights when it comes to professional ethics. The aim of this study was to describe radiographers' perceptions and experiences of their professional rights. The ultimate aim was to increase the understanding of professional ethics in this context and support radiographers' ethical pondering in diagnostic radiography. A qualitative method was used. Semistructured group interviews with 15 radiographers were conducted in spring 2013 at two publicly provided diagnostic imaging departments in Finland. Data were analysed by inductive content analysis. All the participants were women, and they had worked as radiographers for an average of 18 years. Based on our analysis, radiographers' professional rights consisted of rights related to their expertise in radiography and the rights related to working conditions that ensured their wellbeing. Expertise-based rights included rights to plan, conduct and assess radiological care with patient advocacy. Radiographers have the right to contribute to a culture of safe radiation in their organisation and to use their professional knowledge to achieve their main target, which is the safe imaging of patients. Radiographers also have right to work in conditions that support their well-being, including the legal rights stated in their employment contract, as well as their rights concerning resources at work. Radiographers' professional rights are an elementary and multidimensional part of their clinical practice. In future, more theoretical and empirical research is needed to deepen the understanding of their rights in the clinical practice and support radiographers on issues related to this aspect of their work. © 2016

  8. a Single-Exposure Dual-Energy Computed Radiography Technique for Improved Nodule Detection and Classification in Chest Imaging

    NASA Astrophysics Data System (ADS)

    Zink, Frank Edward

    The detection and classification of pulmonary nodules is of great interest in chest radiography. Nodules are often indicative of primary cancer, and their detection is particularly important in asymptomatic patients. The ability to classify nodules as calcified or non-calcified is important because calcification is a positive indicator that the nodule is benign. Dual-energy methods offer the potential to improve both the detection and classification of nodules by allowing the formation of material-selective images. Tissue-selective images can improve detection by virtue of the elimination of obscuring rib structure. Bone -selective images are essentially calcium images, allowing classification of the nodule. A dual-energy technique is introduced which uses a computed radiography system to acquire dual-energy chest radiographs in a single-exposure. All aspects of the dual-energy technique are described, with particular emphasis on scatter-correction, beam-hardening correction, and noise-reduction algorithms. The adaptive noise-reduction algorithm employed improves material-selective signal-to-noise ratio by up to a factor of seven with minimal sacrifice in selectivity. A clinical comparison study is described, undertaken to compare the dual-energy technique to conventional chest radiography for the tasks of nodule detection and classification. Observer performance data were collected using the Free Response Observer Characteristic (FROC) method and the bi-normal Alternative FROC (AFROC) performance model. Results of the comparison study, analyzed using two common multiple observer statistical models, showed that the dual-energy technique was superior to conventional chest radiography for detection of nodules at a statistically significant level (p < .05). Discussion of the comparison study emphasizes the unique combination of data collection and analysis techniques employed, as well as the limitations of comparison techniques in the larger context of technology

  9. Detecting objects in radiographs for homeland security

    NASA Astrophysics Data System (ADS)

    Prasad, Lakshman; Snyder, Hans

    2005-05-01

    We present a general scheme for segmenting a radiographic image into polygons that correspond to visual features. This decomposition provides a vectorized representation that is a high-level description of the image. The polygons correspond to objects or object parts present in the image. This characterization of radiographs allows the direct application of several shape recognition algorithms to identify objects. In this paper we describe the use of constrained Delaunay triangulations as a uniform foundational tool to achieve multiple visual tasks, namely image segmentation, shape decomposition, and parts-based shape matching. Shape decomposition yields parts that serve as tokens representing local shape characteristics. Parts-based shape matching enables the recognition of objects in the presence of occlusions, which commonly occur in radiographs. The polygonal representation of image features affords the efficient design and application of sophisticated geometric filtering methods to detect large-scale structural properties of objects in images. Finally, the representation of radiographs via polygons results in significant reduction of image file sizes and permits the scalable graphical representation of images, along with annotations of detected objects, in the SVG (scalable vector graphics) format that is proposed by the world wide web consortium (W3C). This is a textual representation that can be compressed and encrypted for efficient and secure transmission of information over wireless channels and on the Internet. In particular, our methods described here provide an algorithmic framework for developing image analysis tools for screening cargo at ports of entry for homeland security.

  10. Optimization of dual energy contrast enhanced breast tomosynthesis for improved mammographic lesion detection and diagnosis

    NASA Astrophysics Data System (ADS)

    Saunders, R.; Samei, E.; Badea, C.; Yuan, H.; Ghaghada, K.; Qi, Y.; Hedlund, L. W.; Mukundan, S.

    2008-03-01

    Dual-energy contrast-enhanced breast tomosynthesis has been proposed as a technique to improve the detection of early-stage cancer in young, high-risk women. This study focused on optimizing this technique using computer simulations. The computer simulation used analytical calculations to optimize the signal difference to noise ratio (SdNR) of resulting images from such a technique at constant dose. The optimization included the optimal radiographic technique, optimal distribution of dose between the two single-energy projection images, and the optimal weighting factor for the dual energy subtraction. Importantly, the SdNR included both anatomical and quantum noise sources, as dual energy imaging reduces anatomical noise at the expense of increases in quantum noise. Assuming a tungsten anode, the maximum SdNR at constant dose was achieved for a high energy beam at 49 kVp with 92.5 μm copper filtration and a low energy beam at 49 kVp with 95 μm tin filtration. These analytical calculations were followed by Monte Carlo simulations that included the effects of scattered radiation and detector properties. Finally, the feasibility of this technique was tested in a small animal imaging experiment using a novel iodinated liposomal contrast agent. The results illustrated the utility of dual energy imaging and determined the optimal acquisition parameters for this technique. This work was supported in part by grants from the Komen Foundation (PDF55806), the Cancer Research and Prevention Foundation, and the NIH (NCI R21 CA124584-01). CIVM is a NCRR/NCI National Resource under P41-05959/U24-CA092656.

  11. Association of hip pain with radiographic evidence of hip osteoarthritis: diagnostic test study

    PubMed Central

    Nevitt, Michael C; Niu, Jingbo; Clancy, Mary M; Lane, Nancy E; Link, Thomas M; Vlad, Steven; Tolstykh, Irina; Jungmann, Pia M.; Felson, David T; Guermazi, Ali

    2015-01-01

    Study question Is there concordance between hip pain and radiographic hip osteoarthritis? Methods In this diagnostic test study, pelvic radiographs were assessed for hip osteoarthritis in two cohorts: the Framingham Osteoarthritis Study (community of Framingham, Massachusetts) and the Osteoarthritis Initiative (a multicenter longitudinal cohort study of osteoarthritis in the United States). Using visual representation of the hip joint, participants reported whether they had hip pain on most days and the location of the pain: anterior, groin, lateral, buttocks, or low back. In the Framingham study, participants with hip pain were also examined for hip pain with internal rotation. The authors analysed the agreement between radiographic hip osteoarthritis and hip pain, and for those with hip pain suggestive of hip osteoarthritis they calculated the sensitivity, specificity, positive predictive value, and negative predictive value of radiographs as the diagnostic test. Study answer and limitations In the Framingham study (n=946), only 15.6% of hips in patients with frequent hip pain showed radiographic evidence of hip osteoarthritis, and 20.7% of hips with radiographic hip osteoarthritis were frequently painful. The sensitivity of radiographic hip osteoarthritis for hip pain localised to the groin was 36.7%, specificity 90.5%, positive predictive value 6.0%, and negative predictive value 98.9%. Results did not differ much for hip pain at other locations or for painful internal rotation. In the Osteoarthritis Initiative study (n=4366), only 9.1% of hips in patients with frequent pain showed radiographic hip osteoarthritis, and 23.8% of hips with radiographic hip osteoarthritis were frequently painful. The sensitivity of definite radiographic hip osteoarthritis for hip pain localised to the groin was 16.5%, specificity 94.0%, positive predictive value 7.1%, and negative predictive value 97.6%. Results also did not differ much for hip pain at other locations. What this

  12. Follow-up chest radiographic findings in patients with MERS-CoV after recovery

    PubMed Central

    Das, Karuna M; Lee, Edward Y; Singh, Rajvir; Enani, Mushira A; Al Dossari, Khalid; Van Gorkom, Klaus; Larsson, Sven G; Langer, Ruth D

    2017-01-01

    Purpose: To evaluate the follow-up chest radiographic findings in patients with Middle East respiratory syndrome coronavirus (MERS-CoV) who were discharged from the hospital following improved clinical symptoms. Materials and Methods: Thirty-six consecutive patients (9 men, 27 women; age range 21–73 years, mean ± SD 42.5 ± 14.5 years) with confirmed MERS-CoV underwent follow-up chest radiographs after recovery from MERS-CoV. The 36 chest radiographs were obtained at 32 to 230 days with a median follow-up of 43 days. The reviewers systemically evaluated the follow-up chest radiographs from 36 patients for lung parenchymal, airway, pleural, hilar and mediastinal abnormalities. Lung parenchyma and airways were assessed for consolidation, ground-glass opacity (GGO), nodular opacity and reticular opacity (i.e., fibrosis). Follow-up chest radiographs were also evaluated for pleural thickening, pleural effusion, pneumothorax and lymphadenopathy. Patients were categorized into two groups: group 1 (no evidence of lung fibrosis) and group 2 (chest radiographic evidence of lung fibrosis) for comparative analysis. Patient demographics, length of ventilations days, number of intensive care unit (ICU) admission days, chest radiographic score, chest radiographic deterioration pattern (Types 1-4) and peak lactate dehydrogenase level were compared between the two groups using the student t-test, Mann-Whitney U test and Fisher's exact test. Results: Follow-up chest radiographs were normal in 23 out of 36 (64%) patients. Among the patients with abnormal chest radiographs (13/36, 36%), the following were found: lung fibrosis in 12 (33%) patients GGO in 2 (5.5%) patients, and pleural thickening in 2 (5.5%) patients. Patients with lung fibrosis had significantly greater number of ICU admission days (19 ± 8.7 days; P value = 0.001), older age (50.6 ± 12.6 years; P value = 0.02), higher chest radiographic scores [10 (0-15.3); P value = 0.04] and higher peak lactate dehydrogenase

  13. Adult congenital heart disease imaging with second-generation dual-source computed tomography: initial experiences and findings.

    PubMed

    Ghoshhajra, Brian B; Sidhu, Manavjot S; El-Sherief, Ahmed; Rojas, Carlos; Yeh, Doreen Defaria; Engel, Leif-Christopher; Liberthson, Richard; Abbara, Suhny; Bhatt, Ami

    2012-01-01

    Adult congenital heart disease patients present a unique challenge to the cardiac imager. Patients may present with both acute and chronic manifestations of their complex congenital heart disease and also require surveillance for sequelae of their medical and surgical interventions. Multimodality imaging is often required to clarify their anatomy and physiology. Radiation dose is of particular concern in these patients with lifelong imaging needs for their chronic disease. The second-generation dual-source scanner is a recently available advanced clinical cardiac computed tomography (CT) scanner. It offers a combination of the high-spatial resolution of modern CT, the high-temporal resolution of dual-source technology, and the wide z-axis coverage of modern cone-beam geometry CT scanners. These advances in technology allow novel protocols that markedly reduce scan time, significantly reduce radiation exposure, and expand the physiologic imaging capabilities of cardiac CT. We present a case series of complicated adult congenital heart disease patients imaged by the second-generation dual-source CT scanner with extremely low-radiation doses and excellent image quality. © 2012 Wiley Periodicals, Inc.

  14. Radiographic Evidence of Femoroacetabular Impingement in Athletes With Athletic Pubalgia

    PubMed Central

    Economopoulos, Kostas J.; Milewski, Matthew D.; Hanks, John B.; Hart, Joseph M.; Diduch, David R.

    2014-01-01

    Background: Two of the most common causes of groin pain in athletes are femoroacetabular impingement (FAI) and athletic pubalgia. An association between the 2 is apparent, but the prevalence of radiographic signs of FAI in patients undergoing athletic pubalgia surgery remains unknown. The purpose of this study was to determine the prevalence of radiologic signs of FAI in patients with athletic pubalgia. Hypothesis: We hypothesized that patients with athletic pubalgia would have a high prevalence of underlying FAI. Study Design: Case series. Level of Evidence: Level 4. Methods: A retrospective review of all patients evaluated at our institution with athletic pubalgia who underwent surgical treatment (ie, for sports hernia) from 1999 to 2011 was performed. The radiographs of patients with athletic pubalgia were reviewed for radiographic signs of FAI. Alpha angles were measured using frog-leg lateral radiographs. Pincer lesions were identified by measuring the lateral center-edge angle and identifying the presence of a “crossover” sign on anteroposterior radiographs. Phone follow-up was performed 2 years or more after the initial sports hernia surgery to evaluate recurrent symptoms. Results: Forty-three patients underwent 56 athletic pubalgia surgeries. Radiographic evidence of FAI was identified in at least 1 hip in 37 of 43 patients (86%). Cam lesions were identified in 83.7% of the population; the alpha angle averaged 66.7° ± 17.9° for all hips. Pincer lesions were present in 28% of the hips. Eight patients had recurrent groin pain, 3 patients had revision athletic pubalgia surgery, and 1 had hip arthroscopy. Conclusion: The study demonstrates a high prevalence of radiographic FAI in patients with athletic pubalgia. Clinical Relevance: Underlying FAI may be a cause of continued groin pain after athletic pubalgia surgery. Patients with athletic pubalgia should be evaluated closely for FAI. PMID:24587869

  15. Radiographic evidence of femoroacetabular impingement in athletes with athletic pubalgia.

    PubMed

    Economopoulos, Kostas J; Milewski, Matthew D; Hanks, John B; Hart, Joseph M; Diduch, David R

    2014-03-01

    Two of the most common causes of groin pain in athletes are femoroacetabular impingement (FAI) and athletic pubalgia. An association between the 2 is apparent, but the prevalence of radiographic signs of FAI in patients undergoing athletic pubalgia surgery remains unknown. The purpose of this study was to determine the prevalence of radiologic signs of FAI in patients with athletic pubalgia. We hypothesized that patients with athletic pubalgia would have a high prevalence of underlying FAI. Case series. Level 4. A retrospective review of all patients evaluated at our institution with athletic pubalgia who underwent surgical treatment (ie, for sports hernia) from 1999 to 2011 was performed. The radiographs of patients with athletic pubalgia were reviewed for radiographic signs of FAI. Alpha angles were measured using frog-leg lateral radiographs. Pincer lesions were identified by measuring the lateral center-edge angle and identifying the presence of a "crossover" sign on anteroposterior radiographs. Phone follow-up was performed 2 years or more after the initial sports hernia surgery to evaluate recurrent symptoms. Forty-three patients underwent 56 athletic pubalgia surgeries. Radiographic evidence of FAI was identified in at least 1 hip in 37 of 43 patients (86%). Cam lesions were identified in 83.7% of the population; the alpha angle averaged 66.7° ± 17.9° for all hips. Pincer lesions were present in 28% of the hips. Eight patients had recurrent groin pain, 3 patients had revision athletic pubalgia surgery, and 1 had hip arthroscopy. The study demonstrates a high prevalence of radiographic FAI in patients with athletic pubalgia. Underlying FAI may be a cause of continued groin pain after athletic pubalgia surgery. Patients with athletic pubalgia should be evaluated closely for FAI.

  16. Dual-mode switching of a liquid crystal panel for viewing angle control

    NASA Astrophysics Data System (ADS)

    Baek, Jong-In; Kwon, Yong-Hoan; Kim, Jae Chang; Yoon, Tae-Hoon

    2007-03-01

    The authors propose a method to control the viewing angle of a liquid crystal (LC) panel using dual-mode switching. To realize both wide viewing angle (WVA) characteristics and narrow viewing angle (NVA) characteristics with a single LC panel, the authors use two different dark states. The LC layer can be aligned homogeneously parallel to the transmission axis of the bottom polarizer for WVA dark state operation, while it can be aligned vertically for NVA dark state operation. The authors demonstrated that viewing angle control can be achieved with a single panel without any loss of contrast at the front.

  17. Method of radiographic inspection of wooden members

    NASA Technical Reports Server (NTRS)

    Berry, Maggie L. (Inventor); Berry, Robert F., Jr. (Inventor)

    1990-01-01

    The invention is a method to be used for radiographic inspection of a wooden specimen for internal defects which includes the steps of introducing a radiopaque penetrant into any internal defects in the specimen through surface openings; passing a beam of radiation through a portion of the specimen to be inspected; and making a radiographic film image of the radiation passing through the specimen, with the radiopaque penetrant in the specimen absorbing the radiation passing through it, thereby enhancing the resulting image of the internal defects in the specimen.

  18. Chest radiographic manifestations of scrub typhus.

    PubMed

    Abhilash, Kpp; Mannam, P R; Rajendran, K; John, R A; Ramasami, P

    2016-01-01

    Respiratory system involvement in scrub typhus is seen in 20-72% of patients. In endemic areas, good understanding and familiarity with the various radiologic findings of scrub typhus are essential in identifying pulmonary complications. Patients admitted to a tertiary care center with scrub typhus between October 2012 and September 2013 and had a chest X ray done were included in the analysis. Details and radiographic findings were noted and factors associated with abnormal X-rays were analyzed. The study cohort contained 398 patients. Common presenting complaints included fever (100%), generalized myalgia (83%), headache (65%), dyspnea (54%), cough (24.3%), and altered sensorium (14%). Almost half of the patients (49.4%) had normal chest radiographs. Common radiological pulmonary abnormalities included pleural effusion (14.6%), acute respiratory distress syndrome (14%), airspace opacity (10.5%), reticulonodular opacities (10.3%), peribronchial thickening (5.8%), and pulmonary edema (2%). Cardiomegaly was noted in 3.5% of patients. Breathlessness, presence of an eschar, platelet counts of <20,000 cells/cumm, and total serum bilirubin >2 mg/dL had the highest odds of having an abnormal chest radiograph. Patients with an abnormal chest X-ray had a higher requirement of noninvasive ventilation (odds ratio [OR]: 13.98; 95% confidence interval CI: 5.89-33.16), invasive ventilation (OR: 18.07; 95% CI: 6.42-50.88), inotropes (OR: 8.76; 95% CI: 4.35-17.62), higher involvement of other organ systems, longer duration of hospital stay (3.18 ± 3 vs. 7.27 ± 5.58 days; P< 0.001), and higher mortality (OR: 4.63; 95% CI: 1.54-13.85). Almost half of the patients with scrub typhus have abnormal chest radiographs. Chest radiography should be included as part of basic evaluation at presentation in patients with scrub typhus, especially in those with breathlessness, eschar, jaundice, and severe thrombocytopenia.

  19. Diagnosing Femoroacetabular Impingement From Plain Radiographs

    PubMed Central

    Ayeni, Olufemi R.; Chan, Kevin; Whelan, Daniel B.; Gandhi, Rajiv; Williams, Dale; Harish, Srinivasan; Choudur, Hema; Chiavaras, Mary M.; Karlsson, Jon; Bhandari, Mohit

    2014-01-01

    Background: A diagnosis of femoroacetabular impingement (FAI) requires careful history and physical examination, as well as an accurate and reliable radiologic evaluation using plain radiographs as a screening modality. Radiographic markers in the diagnosis of FAI are numerous and not fully validated. In particular, reliability in their assessment across health care providers is unclear. Purpose: To determine inter- and intraobserver reliability between orthopaedic surgeons and musculoskeletal radiologists. Study Design: Cohort study (diagnosis); Level of evidence, 3. Methods: Six physicians (3 orthopaedic surgeons, 3 musculoskeletal radiologists) independently evaluated a broad spectrum of FAI pathologies across 51 hip radiographs on 2 occasions separated by at least 4 weeks. Reviewers used 8 common criteria to diagnose FAI, including (1) pistol-grip deformity, (2) size of alpha angle, (3) femoral head-neck offset, (4) posterior wall sign abnormality, (5) ischial spine sign abnormality, (6) coxa profunda abnormality, (7) crossover sign abnormality, and (8) acetabular protrusion. Agreement was calculated using the intraclass correlation coefficient (ICC). Results: When establishing an FAI diagnosis, there was poor interobserver reliability between the surgeons and radiologists (ICC batch 1 = 0.33; ICC batch 2 = 0.15). In contrast, there was higher interobserver reliability within each specialty, ranging from fair to good (surgeons: ICC batch 1 = 0.72; ICC batch 2 = 0.70 vs radiologists: ICC batch 1 = 0.59; ICC batch 2 = 0.74). Orthopaedic surgeons had the highest interobserver reliability when identifying pistol-grip deformities (ICC = 0.81) or abnormal alpha angles (ICC = 0.81). Similarly, radiologists had the highest agreement for detecting pistol-grip deformities (ICC = 0.75). Conclusion: These results suggest that surgeons and radiologists agree among themselves, but there is a need to improve the reliability of radiographic interpretations for FAI between the

  20. [Comparative Study of Patient Identifications for Conventional and Portable Chest Radiographs Utilizing ROC Analysis].

    PubMed

    Kawashima, Hiroki; Hayashi, Norio; Ohno, Naoki; Matsuura, Yukihiro; Sanada, Shigeru

    2015-08-01

    To evaluate the patient identification ability of radiographers, previous and current chest radiographs were assessed with observer study utilizing a receiver operating characteristics (ROCs) analysis. This study included portable and conventional chest radiographs from 43 same and 43 different patients. The dataset used in this study was divided into the three following groups: (1) a pair of portable radiographs, (2) a pair of conventional radiographs, and (3) a combination of each type of radiograph. Seven observers participated in this ROC study, which aimed to identify same or different patients, using these datasets. ROC analysis was conducted to calculate the average area under ROC curve obtained by each observer (AUCave), and a statistical test was performed using the multi-reader multi-case method. Comparable results were obtained with pairs of portable (AUCave: 0.949) and conventional radiographs (AUCave: 0.951). In a comparison between the same modality, there were no significant differences. In contrast, the ability to identify patients by comparing a portable and conventional radiograph (AUCave: 0.873) was lower than with the matching datasets (p=0.002 and p=0.004, respectively). In conclusion, the use of different imaging modalities reduces radiographers' ability to identify their patients.

  1. Diagnostic value of chest radiographs in bedridden patients suspected of having pneumonia.

    PubMed

    Esayag, Yaacov; Nikitin, Irina; Bar-Ziv, Jacob; Cytter, Ruth; Hadas-Halpern, Irith; Zalut, Todd; Yinnon, Amos M

    2010-01-01

    To assess the diagnostic value of the chest radiograph for the diagnosis of pneumonia in bedridden patients, using non-contrast-enhanced high-resolution chest computed tomography (CT) as the gold standard. We prospectively evaluated bedridden patients hospitalized with moderate to high clinical probability of pneumonia. Chest radiographs were interpreted in a blinded fashion by 3 observers and classified as definite, normal, or uncertain for pneumonia. Chest CT was obtained within 12 hours of chest radiograph. We applied Bayesian analysis to assess the accuracy of chest radiograph in the diagnosis of pneumonia. In a 5-month period, 58 patients were evaluated, 31 (53%) were female. Their chest radiographs were interpreted as negative, uncertain, or positive for pneumonia in 31 (53%), 15 (26%), and 12 (21%) patients, respectively, while CT confirmed pneumonia in 11 (35%), 10 (67%), and in 10 (83%). The sensitivity of the chest radiograph to diagnose pneumonia was 65%, the specificity was 93%, the positive and negative predictive values were, respectively, 83% and 65%, while the overall accuracy was 69% (95% confidence interval, 50%-79%). In bedridden patients with suspected pneumonia, a normal chest radiograph does not rule out the diagnosis, hence, a chest CT scan might provide valuable diagnostic information. Copyright 2010 Elsevier Inc. All rights reserved.

  2. Radiographic Assessment for Back Pain

    MedlinePlus

    ... under the age of 18, or are a student athlete, if you have a history of osteoporosis, ... bending to better determine the cause of your pain. Lateral flexion and extension (bending forward and ... Degenerative Disc Disease NSAIDs Radiographic Assessment ...

  3. Computer enhancement of radiographs

    NASA Technical Reports Server (NTRS)

    Dekaney, A.; Keane, J.; Desautels, J.

    1973-01-01

    Examination of three relevant noise processes and the image degradation associated with Marshall Space Flight Center's (MSFC) X-ray/scanning system was conducted for application to computer enhancement of radiographs using MSFC's digital filtering techniques. Graininess of type M, R single coat and R double coat X-ray films was quantified as a function of density level using root-mean-square (RMS) granularity. Quantum mottle (including film grain) was quantified as a function of the above film types, exposure level, specimen material and thickness, and film density using RMS granularity and power spectral density (PSD). For various neutral-density levels the scanning device used in digital conversion of radiographs was examined for noise characteristics which were quantified by RMS granularity and PSD. Image degradation of the entire pre-enhancement system (MG-150 X-ray device; film; and optronics scanner) was measured using edge targets to generate modulation transfer functions (MTF). The four parameters were examined as a function of scanning aperture sizes of approximately 12.5 25 and 50 microns.

  4. Dual-Vivaldi wideband nanoantenna with high radiation efficiency over the infrared frequency band.

    PubMed

    Iluz, Zeev; Boag, Amir

    2011-08-01

    A dual-Vivaldi nanoantenna is proposed to demonstrate the possibility of wideband operation at IR frequencies. The antenna geometry design is guided by the material properties of metals at IR frequencies. According to our numerical results, this nanoantenna has both high radiation efficiency and good impedance-matching properties over a wide frequency band (more than 122%) in the IR frequency band. The design is based on the well-known Vivaldi antenna placed on quartz substrate but operating as a pair instead of a single element. Such a pair of Vivaldi antennas oriented in opposite directions produces the main lobe in the broadside direction (normal to the axes of the antennas) rather than the usual peak gain along the axis (end fire) of a single Vivaldi antenna. The dual-Vivaldi nanoantenna is easy to fabricate in a conventional electron-beam lithography process, and it provides a large number of degrees of freedom, facilitating design for ultra-wideband operation. © 2011 Optical Society of America

  5. Coronal and Intraradicular Appearances Affect Radiographic Perception of the Periapical Region.

    PubMed

    Strong, Julie W; Woodmansey, Karl F; Khademi, John A; Hatton, John F

    2017-05-01

    The influence of the radiographic appearances of the coronal and intraradicular areas on periapical radiographic interpretation has been minimally evaluated in dentistry and endodontics. The purpose of this study was to evaluate the effects that the coronal and intraradicular radiographic appearance has on endodontists' radiographic interpretations of periapical areas. In a split-group study design using an online survey format, 2 pairs of digital periapical radiographic images were evaluated by 2 groups (A and B) of endodontist readers for the presence of a periapical finding. The images in each pair were identical except that 1 image of each image pairs had coronal restorations and/or root canal fillings altered using Adobe Photoshop software (Adobe Systems, San Jose, CA). The periapical areas were not altered. Using a 5-point Likert scale, the endodontist readers were asked to "Please evaluate the periapical area(s)." A Mann-Whitney U test was used to statistically evaluate the difference between the groups. Significance was set at P < .01. There were 417 readers in group A and 442 readers in group B. The Mann-Whitney U test showed a significant difference in the responses between the groups for both image pairs (P < .01). Because the periapical areas of the image pairs were unaltered, the differing coronal and intraradicular areas of the radiographs appear to have influenced endodontists' interpretations of the periapical areas. This finding has implications for all radiographic outcome assessments. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  6. Sequence-dependent rotation axis changes in tennis.

    PubMed

    Hansen, Clint; Martin, Caroline; Rezzoug, Nasser; Gorce, Philippe; Bideau, Benoit; Isableu, Brice

    2017-09-01

    The purpose of this study was to evaluate the role of rotation axes during a tennis serve. A motion capture system was used to evaluate the contribution of the potential axes of rotation (minimum inertia axis, shoulder-centre of mass axis and the shoulder-elbow axis) during the four discrete tennis serve phases (loading, cocking, acceleration and follow through). Ten ranked athletes (International Tennis Number 1-3) repeatedly performed a flat service aiming at a target on the other side of the net. The four serve phases are distinct and thus, each movement phase seems to be organised around specific rotation axes. The results showed that the limbs' rotational axis does not necessarily coincide with the minimum inertia axis across the cocking phase of the tennis serve. Even though individual serving strategies were exposed, all participants showed an effect due to the cocking phase and changed the rotation axis during the task. Taken together, the results showed that despite inter-individual differences, nine out of 10 participants changed the rotation axis towards the minimum inertia and/or the mass axis in an endeavour to maximise external rotation of the shoulder to optimally prepare for the acceleration phase.

  7. Radiographic evaluation of BFX acetabular component position in dogs.

    PubMed

    Renwick, Alasdair; Gemmill, Toby; Pink, Jonathan; Brodbelt, David; McKee, Malcolm

    2011-07-01

    To assess the reliability of radiographic measurement of angle of lateral opening (ALO) and angle of version of BFX acetabular cups. In vitro radiographic study. BFX cups (24, 28, and 32 mm). Total hip replacement constructs (cups, 17 mm femoral head and a #7 CFX stem) were mounted on an inclinometer. Ventrodorsal radiographs were obtained with ALO varying between 21° and 70° and inclination set at 0°, 10°, 20°, and 30°. Radiographs were randomized using a random sequence generator. Three observers blinded to the radiograph order assessed ALO using 3 methods: (1) an ellipse method based on trigonometry; (2) using a measurement from the center of the femoral head to the truncated surface of the cup; (3) by visual estimation using a reference chart. Version was measured by assessing the ventral edge of the truncated surface. ALO methods 2 and 3 were accurate and precise to within 10° and were significantly more accurate and precise than method 1 (P < .001). All methods were significantly less accurate with increasing inclination. Version measurement was accurate and precise to within 7° with 0-20° of inclination, but significantly less accurate with 30° of inclination. Methods 2 and 3, but not method 1, were sufficiently accurate and precise to be clinically useful. Version measurement was clinically useful when inclination was ≤ 20°. © Copyright 2011 by The American College of Veterinary Surgeons.

  8. Microchip solid-state cylindrical vector lasers with orthogonally polarized dual laser-diode end pumping.

    PubMed

    Otsuka, Kenju; Chu, Shu-Chun

    2013-05-01

    We report a simple method for generating cylindrical vector beams directly from laser-diode (LD)-pumped microchip solid-state lasers by using dual end-pumping beams. Radially as well as azimuthally polarized vector field emissions have been generated from the common c-cut Nd:GdVO4 laser cavity merely by controlling the focus positions of orthogonally polarized LD off-axis pump beams. Hyperbolically polarized vector fields have also been observed, in which the cylindrical symmetry of vector fields is broken. Experimental results have been well reproduced by numerical simulations.

  9. Radiographic analysis of the correlation between ossification of the nuchal ligament and sagittal alignment and segmental stability of the cervical spine in patients with cervical spondylotic myelopathy.

    PubMed

    Ying, Jinwei; Teng, Honglin; Qian, Yunfan; Hu, Yingying; Wen, Tianyong; Ruan, Dike; Zhu, Minyu

    2018-01-01

    Background Ossification of the nuchal ligament (ONL) caused by chronic injury to the nuchal ligament (NL) is very common in instability-related cervical disorders. Purpose To determine possible correlations between ONL, sagittal alignment, and segmental stability of the cervical spine. Material and Methods Seventy-three patients with cervical spondylotic myelopathy (CSM) and ONL (ONL group) and 118 patients with CSM only (control group) were recruited. Radiographic data included the characteristics of ONL, sagittal alignment and segmental stability, and ossification of the posterior longitudinal ligament (OPLL). We performed comparisons in terms of radiographic parameters between the ONL and control groups. The correlations between ONL size, cervical sagittal alignment, and segmental stability were analyzed. Multivariate logistic regression was used to identify the independent risk factors of the development of ONL. Results C2-C7 sagittal vertical axis (SVA), T1 slope (T1S), T1S minus cervical lordosis (T1S-CL) on the lateral plain, angular displacement (AD), and horizontal displacement (HD) on the dynamic radiograph increased significantly in the ONL group compared with the control group. The size of ONL significantly correlated with C2-C7 SVA, T1S, AD, and HD. The incidence of ONL was higher in patients with OPLL and segmental instability. Cervical instability, sagittal malalignment, and OPLL were independent predictors of the development of ONL through multivariate analysis. Conclusion Patients with ONL are more likely to have abnormal sagittal alignment and instability of the cervical spine. Thus, increased awareness and appreciation of this often-overlooked radiographic finding is warranted during diagnosis and treatment of instability-related cervical pathologies and injuries.

  10. External Ventricular Drain and Hemorrhage in Aneurysmal Subarachnoid Hemorrhage Patients on Dual Antiplatelet Therapy: A Retrospective Cohort Study.

    PubMed

    Hudson, Joseph S; Prout, Benjamin S; Nagahama, Yasunori; Nakagawa, Daichi; Guerrero, Waldo R; Zanaty, Mario; Chalouhi, Nohra; Jabbour, Pascal; Dandapat, Sudeepta; Allan, Lauren; Ortega-Gutierrez, Santiago; Samaniego, Edgar A; Hasan, David

    2018-04-11

    Stenting and flow diversion for aneurysmal sub arachnoid hemorrhage (aSAH) require the use of dual antiplatelet therapy (DAPT). To investigate whether DAPT is associated with hemorrhagic complication following placement of external ventricular drains (EVD) in patients with aSAH. Rates of radiographically identified hemorrhage associated with EVD placement were compared between patients who received DAPT for stenting or flow diversion, and patients who underwent microsurgical clipping or coiling and did not receive DAPT by way of a backward stepwise multivariate analysis. Four hundred forty-three patients were admitted for aSAH management. Two hundred ninety-eight patients required placement of an EVD. One hundred twenty patients (40%) were treated with stent-assisted coiling or flow diversion and required DAPT, while 178 patients (60%) were treated with coiling without stents or microsurgical clipping and did not receive DAPT. Forty-two (14%) cases of new hemorrhage along the EVD catheter were identified radiographically. Thirty-two of these hemorrhages occurred in patients on DAPT, while 10 occurred in patients without DAPT. After multivariate analysis, DAPT was significantly associated with radiographic hemorrhage [odds ratio: 4.92, 95% confidence interval: 2.45-9.91, P = .0001]. We did not observe an increased proportion of symptomatic hemorrhage in patients receiving DAPT (10 of 32 [31%]) vs those without (5 of 10 [50%]; P = .4508). Patients with aSAH who receive stent-assisted coiling or flow diversion are at higher risk for radiographic hemorrhage associated with EVD placement. The timing between EVD placement and DAPT initiation does not appear to be of clinical significance. Stenting and flow diversion remain viable options for aSAH patients.

  11. Application of external axis in thermal spraying

    NASA Astrophysics Data System (ADS)

    Gao, Guoyou; Wang, Wei; Chen, Tao; Hui, Chun

    2018-05-01

    Industrial robots are widely used nowadays in the process of thermal spraying, human work can be largely replaced due to the high-efficient, security, precision and repeatability of industrial robot. As offering the convenience to industrial product, Robots have some natural deficiencies because of its mechanical linkages of six-axis. When robot performs a series of stage of production, it could be hard to move to the next one because one of his axis reaches a maximum value. For this reason, external axis is added to robot system to extend the reachable space of robot axis. This paper concerns to the application of external axis and the different methods of programming the robot with work-holding external axis in the virtual environment. Experiments demonstrate the coating layer on the regular workpiece is uniform.

  12. Technologist-Directed Repeat Musculoskeletal and Chest Radiographs: How Often Do They Impact Diagnosis?

    PubMed

    Rosenkrantz, Andrew B; Jacobs, Jill E; Jain, Nidhi; Brusca-Augello, Geraldine; Mechlin, Michael; Parente, Marc; Recht, Michael P

    2017-12-01

    Radiologic technologists may repeat images within a radiographic examination because of perceived suboptimal image quality, excluding these original images from submission to a PACS. This study assesses the appropriateness of technologists' decisions to repeat musculoskeletal and chest radiographs as well as the utility of repeat radiographs in addressing examinations' clinical indication. We included 95 musculoskeletal and 87 chest radiographic examinations in which the technologist repeated one or more images because of perceived image quality issues, rejecting original images from PACS submission. Rejected images were retrieved from the radiograph unit and uploaded for viewing on a dedicated server. Musculoskeletal and chest radiologists reviewed rejected and repeat images in their timed sequence, in addition to the studies' remaining images. Radiologists answered questions regarding the added value of repeat images. The reviewing radiologist agreed with the reason for rejection for 64.2% of musculoskeletal and 60.9% of chest radiographs. For 77.9% and 93.1% of rejected radiographs, the clinical inquiry could have been satisfied without repeating the image. For 75.8% and 64.4%, the repeated images showed improved image quality. Only 28.4% and 3.4% of repeated images were considered to provide additional information that was helpful in addressing the clinical question. Most repeated radiographs (chest more so than musculoskeletal radiographs) did not add significant clinical information or alter diagnosis, although they did increase radiation exposure. The decision to repeat images should be made after viewing the questionable image in context with all images in a study and might best be made by a radiologist rather than the performing technologist.

  13. Quantitative radiographic analysis of fiber reinforced polymer composites.

    PubMed

    Baidya, K P; Ramakrishna, S; Rahman, M; Ritchie, A

    2001-01-01

    X-ray radiographic examination of the bone fracture healing process is a widely used method in the treatment and management of patients. Medical devices made of metallic alloys reportedly produce considerable artifacts that make the interpretation of radiographs difficult. Fiber reinforced polymer composite materials have been proposed to replace metallic alloys in certain medical devices because of their radiolucency, light weight, and tailorable mechanical properties. The primary objective of this paper is to provide a comparable radiographic analysis of different fiber reinforced polymer composites that are considered suitable for biomedical applications. Composite materials investigated consist of glass, aramid (Kevlar-29), and carbon reinforcement fibers, and epoxy and polyether-ether-ketone (PEEK) matrices. The total mass attenuation coefficient of each material was measured using clinical X-rays (50 kev). The carbon fiber reinforced composites were found to be more radiolucent than the glass and kevlar fiber reinforced composites.

  14. Dual nozzle aerodynamic and cooling analysis study. [dual throat and dual expander nozzles

    NASA Technical Reports Server (NTRS)

    Meagher, G. M.

    1980-01-01

    Geometric, aerodynamic flow field, performance prediction, and heat transfer analyses are considered for two advanced chamber nozzle concepts applicable to Earth-to-orbit engine systems. Topics covered include improvements to the dual throat aerodynamic and performance prediction program; geometric and flow field analyses of the dual expander concept; heat transfer analysis of both concepts, and engineering analysis of data from the NASA/MSFC hot-fire testing of a dual throat thruster model thrust chamber assembly. Preliminary results obtained are presented in graphs.

  15. Bipolar disorder and substance use disorders. Madrid study on the prevalence of dual disorders/pathology.

    PubMed

    Arias, Francisco; Szerman, Nestor; Vega, Pablo; Mesías, Beatriz; Basurte, Ignacio; Rentero, David

    2017-06-28

    Given its prevalence and impact on public health, the comorbidity of bipolar and substance use disorders is one of the most relevant of dual diagnoses. The objective was to evaluate the characteristics of patients from community mental health and substance abuse centres in Madrid. The sample consisted of 837 outpatients from mental health and substance abuse centres. We used the Mini International Neuropsychiatric Interview (MINI) and Personality Disorder Questionnaire (PDQ4+) to evaluate axis I and II disorders. Of these patients, 174 had a lifetime bipolar disorder, 83 had bipolar disorder type I and 91 had type II. Most patients had dual pathology. Of the 208 participants from the mental health centres, 21 had bipolar disorder and 13 (61.9%) were considered dually-diagnosed patients, while 33.2% of non-bipolar patients had a dual diagnoses (p = 0.03). Of the 629 participants from the substance abuse centres, 153 patients (24.3%) had a bipolar diagnosis. Bipolar dual patients had higher rates of alcohol and cocaine dependence than non-bipolar patients. Moreover, age at onset of alcohol use was earlier in bipolar duallydiagnosed patients than in other alcoholics. Bipolar dually-diagnosed patients had higher personality and anxiety disorder comorbidities and greater suicide risk. Thus, alcohol and cocaine are the drugs most associated with bipolar disorder. Given the nature of the study, the type of relationship between these disorders cannot be determined.

  16. A review of computer aided interpretation technology for the evaluation of radiographs of aluminum welds

    NASA Technical Reports Server (NTRS)

    Lloyd, J. F., Sr.

    1987-01-01

    Industrial radiography is a well established, reliable means of providing nondestructive structural integrity information. The majority of industrial radiographs are interpreted by trained human eyes using transmitted light and various visual aids. Hundreds of miles of radiographic information are evaluated, documented and archived annually. In many instances, there are serious considerations in terms of interpreter fatigue, subjectivity and limited archival space. Quite often it is difficult to quickly retrieve radiographic information for further analysis or investigation. Methods of improving the quality and efficiency of the radiographic process are being explored, developed and incorporated whenever feasible. High resolution cameras, digital image processing, and mass digital data storage offer interesting possibilities for improving the industrial radiographic process. A review is presented of computer aided radiographic interpretation technology in terms of how it could be used to enhance the radiographic interpretation process in evaluating radiographs of aluminum welds.

  17. Infrapatellar fat pad disruption: a radiographic sign of patellar tendon rupture.

    PubMed

    Chin, Kingsley R; Sodl, Jeffrey F

    2005-11-01

    After knee trauma, radiographs showing patella alta supercede other signs that suggest patellar tendon rupture. However, without patella alta the diagnosis may be missed. A standard lateral radiograph with the knee flexed showed the infrapatellar fat pad as a dark band with a smooth contour. Our pilot study identified a disruption of the fat pad contour as a radiographic sign of tendon rupture. Two blinded reviewers independently analyzed randomly selected lateral radiographs of the knees of 14 patients with knee injuries. Seven patients had confirmed ruptures diagnosed at surgery, and the other patients had different diagnoses. There were 12 men and two women with an average age of 49 years (range, 20-81 years). One observer detected five of the seven disrupted tendons and six of the seven intact tendons. The other observer detected six of the seven disrupted tendons and all seven intact tendons. Disruption in the contour of the infrapatellar fat pad on routine lateral view radiographs was a reasonably reliable sign of patellar tendon rupture. Diagnostic accuracy should increase when used with the patient's history, physical examination, and other radiographic signs. Absence of this sign should not supersede other suggestive signs of patella tendon rupture. Diagnostic study, Level II (development of diagnostic criteria on consecutive patients--with universally applied reference "gold" standard). See the Guidelines for Authors for a complete description of levels of evidence.

  18. 42 CFR 37.50 - Interpreting and classifying chest radiographs-film.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Interpreting and classifying chest radiographs-film. 37.50 Section 37.50 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Interpreting and classifying chest radiographs—film. (a) Chest radiographs must be interpreted and classified...

  19. Analysis of physiological impact while reading stereoscopic radiographs

    NASA Astrophysics Data System (ADS)

    Unno, Yasuko Y.; Tajima, Takashi; Kuwabara, Takao; Hasegawa, Akira; Natsui, Nobutaka; Ishikawa, Kazuo; Hatada, Toyohiko

    2011-03-01

    A stereoscopic viewing technology is expected to improve diagnostic performance in terms of reading efficiency by adding one more dimension to the conventional 2D images. Although a stereoscopic technology has been applied to many different field including TV, movies and medical applications, physiological fatigue through reading stereoscopic radiographs has been concerned although no established physiological fatigue data have been provided. In this study, we measured the α-amylase concentration in saliva, heart rates and normalized tissue hemoglobin index (nTHI) in blood of frontal area to estimate physiological fatigue through reading both stereoscopic radiographs and the conventional 2D radiographs. In addition, subjective assessments were also performed. As a result, the pupil contraction occurred just after the reading of the stereoscopic images, but the subjective assessments regarding visual fatigue were nearly identical for the reading the conventional 2D and stereoscopic radiographs. The α-amylase concentration and the nTHI continued to decline while examinees read both 2D and stereoscopic images, which reflected the result of subjective assessment that almost half of the examinees reported to feel sleepy after reading. The subjective assessments regarding brain fatigue showed that there were little differences between 2D and stereoscopic reading. In summary, this study shows that the physiological fatigue caused by stereoscopic reading is equivalent to the conventional 2D reading including ocular fatigue and burden imposed on brain.

  20. Prevalence of dental developmental anomalies: a radiographic study.

    PubMed

    Ezoddini, Ardakani F; Sheikhha, M H; Ahmadi, H

    2007-09-01

    To determine the prevalence of developmental dental anomalies in patients attending the Dental Faculty of Medical University of Yazd, Iran and the gender differences of these anomalies. A retrospective study based on the panoramic radiographs of 480 patients. Patients referred for panoramic radiographs were clinically examined, a detailed family history of any dental anomalies in their first and second degree relatives was obtained and finally their radiographs were studied in detail for the presence of dental anomalies. 40.8% of the patients had dental anomalies. The more common anomalies were dilaceration (15%), impacted teeth (8.3%) and taurodontism (7.5%) and supernumerary teeth (3.5%). Macrodontia and fusion were detected in a few radiographs (0.2%). 49.1% of male patients had dental anomalies compared to 33.8% of females. Dilaceration, taurodontism and supernumerary teeth were found to be more prevalent in men than women, whereas impacted teeth, microdontia and gemination were more frequent in women. Family history of dental anomalies was positive in 34% of the cases.. Taurodontism, gemination, dens in dente and talon cusp were specifically limited to the patients under 20 year's old, while the prevalence of other anomalies was almost the same in all groups. Dilaceration, impaction and taurodontism were relatively common in the studied populaton. A family history of dental anomalies was positive in a third of cases.

  1. Fracture modes in off-axis fiber composites

    NASA Technical Reports Server (NTRS)

    Sinclair, J. H.; Chamis, C. C.

    1978-01-01

    Criteria were developed for identifying, characterizing, and quantifying fracture modes in high-modulus graphite-fiber/resin unidirectional composites subjected to off-axis tensile loading. Procedures are described which use sensitivity analyses and off-axis data to determine the uniaxial strength of fiber composites. It was found that off-axis composites fail by three fracture modes which produce unique fracture surface characteristics. The stress that dominates each fracture mode and the load angle range of its dominance can be identified. Linear composite mechanics is adequate to describe quantitatively the mechanical behavior of off-axis composites. The uniaxial strengths predicted from off-axis data are comparable to these measured in uniaxial tests.

  2. Are We Using Abdominal Radiographs Appropriately in the Management of Pediatric Constipation?

    PubMed

    Beinvogl, Beate; Sabharwal, Sabina; McSweeney, Maireade; Nurko, Samuel

    2017-12-01

    To identify the reasons why pediatric gastroenterologists obtain abdominal radiographs in the management of pediatric constipation. This was a prospective study surveying providers regarding their rationale, interpretation, resultant change, and confidence in their management before and after obtaining KUBs in patients seen for suspected constipation. Demographics and clinical findings were obtained from medical records. A total of 24 providers were surveyed after 72 patient encounters. Reasons for obtaining an abdominal radiograph included evaluation of stool burden (70%), need for a clean out (35%), fecal impaction (27%), cause of abdominal pain (24%), demonstration of stool burden to families (14%), assessment of response to therapy (13%), or encopresis (10%). The plan was changed in 47.6% of cases based on radiographic findings. In cases in which a plan was outlined before obtaining the radiograph (69%), the initial plan was implemented on average in 52.5%. In cases with no plans before obtaining the radiograph, previously unconsidered plans were implemented in 8.7%. Provider confidence in the management plan increased from 2.4 ± 2.7 to 4.1 ± 1.8 (P < .05) after the abdominal radiograph. Abdominal radiographs commonly are obtained by pediatric gastroenterologists in the evaluation and management of constipation. The majority used it to make a diagnosis, and nearly one-half changed their management based on the imaging findings. Overall, they reported an improved confidence in their management plan, despite evidence that radiographic findings poorly correlate with clinical severity. This study highlights the need for further provider education regarding the recommendations delineated in existing constipation guidelines. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Radiographic and ultrasonographic characteristics of ventral abdominal hernia in pigeons (Columba livia).

    PubMed

    Amer, Mohammed S; Hassan, Elham A; Torad, Faisal A

    2018-02-20

    Five female egg-laying pigeons presented with painless, reducible, ventral abdominal swellings located between the keel and the pubis, or close to the cloaca. Based on clinical, radiographic, and ultrasonographic examination, these pigeons were diagnosed with ventral abdominal hernia requiring surgical interference. Reduction was successfully performed under general anesthesia. Radiographic and ultrasonographic examinations were beneficial for confirming the diagnosis and visualizing the hernial content for surgical planning. Lateral radiographs were more helpful than ventrodorsal radiographs for identification of the hernial content and its continuation with the abdominal muscles. Ultrasonographic examination offered a non-invasive diagnostic tool that allowed for the differentiation of hernia from other abdominal swellings. In addition, it played a beneficial role in identification of the hernial content and follow up after surgical interference. In conclusion, radiographic and ultrasonographic examinations were beneficial in the diagnosis, surgical planning, and follow up after surgical interference of ventral abdominal hernia in pigeons.

  4. A study of the quality of duplicated radiographs.

    PubMed

    Erales, F A; Manson-Hing, L R

    1979-01-01

    The resolution, contrast, and clinical appearance of radiographs and duplicate radiographs made with two types of duplicating film were compared. Duplicating conditions evaluated were type and shape of light, light-film distance, type of exposure surface, and developer temperature. Major observations were as follows: both Kodak and DuPont films produced clinically acceptable duplicates; Kodak film was faster; DuPont film responded better in incandescent photoflood light than Kodak film; clear glass with appropriate light-film distance was the best exposure surface.

  5. Comb model for the anomalous diffusion with dual-phase-lag constitutive relation

    NASA Astrophysics Data System (ADS)

    Liu, Lin; Zheng, Liancun; Fan, Yu; Chen, Yanping; Liu, Fawang

    2018-10-01

    As a development of the Fick's model, the dual-phase-lag constitutive relationship with macroscopic and microscopic relaxation characteristics is introduced to describe the anomalous diffusion in comb model. The Dirac delta function in the formulated governing equation represents the special spatial structure of comb model that the horizontal current only exists on the x axis. Solutions are obtained by analytical method with Laplace transform and Fourier transform. The dependence of concentration field and mean square displacement on different parameters are presented and discussed. Results show that the macroscopic and microscopic relaxation parameters have opposite effects on the particle distribution and mean square displacement. Furthermore, four significant results with constant 1/2 are concluded, namely the product of the particle number and the mean square displacement on the x axis equals to 1/2, the exponent of mean square displacement is 1/2 at the special case τq= τP, an asymptotic form of mean square displacement (MSD∼t1/2 as t→0, ∞) is obtained as well at the short time behavior and the long time behavior.

  6. Horizontal-axis clothes washer market poised for expansion

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    George, K.L.

    1994-12-31

    The availability of energy- and water-efficient horizontal-axis washing machines in the North American market is growing, as US and European manufacturers position for an expected long-term market shift toward horizontal-axis (H-axis) technology. Four of the five major producers of washing machines in the US are developing or considering new H-axis models. New entrants, including US-based Staber Industries and several European manufacturers, are also expected to compete in this market. The intensified interest in H-axis technology is partly driven by speculation that new US energy efficiency standards, to be proposed in 1996 and implemented in 1999, will effectively mandate H-axis machines.more » H-axis washers typically use one-third to two-thirds less energy, water, and detergent than vertical-axis machines. Some models also reduce the energy needed to dry the laundry, since their higher spin speeds extract more water than is typical with vertical-axis designs. H-axis washing machines are the focus of two broadly-based efforts to support coordinated research and incentive programs by electric, gas, and water utilities: The High-Efficiency Laundry Metering/Marketing Analysis (THELMA), and the Consortium for Energy Efficiency (CEE) High-Efficiency Clothes Washer Initiative. These efforts may help to pave the way for new types of marketing partnerships among utilities and other parties that could help to speed adoption of H-axis washers.« less

  7. Correlation between broiler lameness and anatomical measurements of bone using radiographical projections with assessments of consistency across and within radiographs.

    PubMed

    Toscano, M J; Nasr, M A F; Hothersall, B

    2013-09-01

    Lameness represents a major welfare and production issue in the poultry industry with a recent survey estimating 27% of birds lame and 3% unable to walk by 40 d of age. A variety of factors may induce lameness and are typically grouped into 2 broad classes on the basis of being infectious or skeletal in nature with the latter accounting for the majority of cases. The current work sought to build upon a large body of literature assessing the anatomical properties of bone in lame birds. Our specific objectives sought to identify relationships between relevant anatomical properties of the tibia and metatarsus using digital quantification from radiographs of legs and a measure of walking difficulty. Resulting output was statistically analyzed to assess 1) observer reliability for consistency in placing the leg during the radiograph procedure and quantification of the various measures within a radiograph, 2) the relationship between the various measurements of anatomical bone properties and sex, bird mass, and gait score, and 3) the relationship between each measurement and leg symmetry. Our anatomical bone measures were found to be reliable (intra-rater and test-retest reliabilities < 0.75) within radiograph for all measures and 8 of the 10 measures across radiographs. Several measures of bone properties in the tibia correlated to difficulty walking as measured by gait score (P < 0.05), indicating greater angulations with increasing lameness. Of the measures that manifested a gait score × bird mass interaction, heavier birds appeared to exhibit less angulation with increasing difficulty walking with lighter birds the opposite. These interactions suggest possibilities for influencing effects of activity or feed intake on bone mineralization with the bone angulation observed. Our efforts agree with that of others and indicate that angulation of the tibia may be related to lameness, though subsequent efforts involving comprehensive measures of bird activity, growth rates

  8. A Study of Radiographic Imaging Systems Used for Dental Hygiene.

    ERIC Educational Resources Information Center

    Karst, Nancy S.

    Thirty-three two-year dental hygiene programs throughout the United States were surveyed to identify the radiographic imaging system most often used and the accompanying rationale for that decision. A literature review identified the three radiographic imaging systems most frequently used and indicated that all dental hygiene programs had the…

  9. Comparisons of NIF convergent ablation simulations with radiograph data.

    PubMed

    Olson, R E; Hicks, D G; Meezan, N B; Koch, J A; Landen, O L

    2012-10-01

    A technique for comparing simulation results directly with radiograph data from backlit capsule implosion experiments will be discussed. Forward Abel transforms are applied to the kappa*rho profiles of the simulation. These provide the transmission ratio (optical depth) profiles of the simulation. Gaussian and top hat blurs are applied to the simulated transmission ratio profiles in order to account for the motion blurring and imaging slit resolution of the experimental measurement. Comparisons between the simulated transmission ratios and the radiograph data lineouts are iterated until a reasonable backlighter profile is obtained. This backlighter profile is combined with the blurred, simulated transmission ratios to obtain simulated intensity profiles that can be directly compared with the radiograph data. Examples will be shown from recent convergent ablation (backlit implosion) experiments at the NIF.

  10. Off-axis illumination direct-to-digital holography

    DOEpatents

    Thomas, Clarence E.; Price, Jeffery R.; Voelkl, Edgar; Hanson, Gregory R.

    2004-06-08

    Systems and methods are described for off-axis illumination direct-to-digital holography. A method of recording an off-axis illuminated spatially heterodyne hologram including spatially heterodyne fringes for Fourier analysis, includes: reflecting a reference beam from a reference mirror at a non-normal angle; reflecting an object beam from an object at an angle with respect to an optical axis defined by a focusing lens; focusing the reference beam and the object beam at a focal plane of a digital recorder to form the off-axis illuminated spatially heterodyne hologram including spatially heterodyne fringes for Fourier analysis; digitally recording the off-axis illuminated spatially heterodyne hologram including spatially heterodyne fringes for Fourier analysis; Fourier analyzing the recorded off-axis illuminated spatially heterodyne hologram including spatially heterodyne fringes by transforming axes of the recorded off-axis illuminated spatially heterodyne hologram including spatially heterodyne fringes in Fourier space to sit on top of a heterodyne carrier frequency defined as an angle between the reference beam and the object beam; applying a digital filter to cut off signals around an original origin; and then performing an inverse Fourier transform.

  11. Vertical or horizontal orientation of foot radiographs does not affect image interpretation

    PubMed Central

    Ferran, Nicholas Antonio; Ball, Luke; Maffulli, Nicola

    2012-01-01

    Summary This study determined whether the orientation of dorsoplantar and oblique foot radiographs has an effect on radiograph interpretation. A test set of 50 consecutive foot radiographs were selected (25 with fractures, and 25 normal), and duplicated in the horizontal orientation. The images were randomly arranged, numbered 1 through 100, and analysed by six image interpreters. Vertical and horizontal area under the ROC curve, accuracy, sensitivity and specificity were calculated for each image interpreter. There was no significant difference in the area under the ROC curve, accuracy, sensitivity or specificity of image interpretation between images viewed in the vertical or horizontal orientation. While conventions for display of radiographs may help to improve the development of an efficient visual search strategy in trainees, and allow for standardisation of publication of radiographic images, variation from the convention in clinical practice does not appear to affect the sensitivity or specificity of image interpretation. PMID:23738310

  12. Validity of radiographic assessment of the knee joint space using automatic image analysis.

    PubMed

    Komatsu, Daigo; Hasegawa, Yukiharu; Kojima, Toshihisa; Seki, Taisuke; Ikeuchi, Kazuma; Takegami, Yasuhiko; Amano, Takafumi; Higuchi, Yoshitoshi; Kasai, Takehiro; Ishiguro, Naoki

    2016-09-01

    The present study investigated whether there were differences between automatic and manual measurements of the minimum joint space width (mJSW) on knee radiographs. Knee radiographs of 324 participants in a systematic health screening were analyzed using the following three methods: manual measurement of film-based radiographs (Manual), manual measurement of digitized radiographs (Digital), and automatic measurement of digitized radiographs (Auto). The mean mJSWs on the medial and lateral sides of the knees were determined using each method, and measurement reliability was evaluated using intra-class correlation coefficients. Measurement errors were compared between normal knees and knees with radiographic osteoarthritis. All three methods demonstrated good reliability, although the reliability was slightly lower with the Manual method than with the other methods. On the medial and lateral sides of the knees, the mJSWs were the largest in the Manual method and the smallest in the Auto method. The measurement errors of each method were significantly larger for normal knees than for radiographic osteoarthritis knees. The mJSW measurements are more accurate and reliable with the Auto method than with the Manual or Digital method, especially for normal knees. Therefore, the Auto method is ideal for the assessment of the knee joint space.

  13. A laboratory evaluation of four quality control devices for radiographic processing.

    PubMed

    Rushton, V E; Horner, K

    1994-08-01

    Quality assurance programmes for radiographic processing traditionally employ expensive sensitometric and densitometric techniques. However cheap and simple devices for monitoring radiographic processing are available. The aim of this study was to make a comparison of four such devices in terms of their ability to detect variations in radiographic density of clinical significance. Three of the devices are commercially available while the fourth is easily manufactured from waste materials. Ideal bitewing exposure times were selected for four different kilovoltage/film speed combinations. Phantom bitewing radiographs, exposed using these exposure times, were processed using a variety of times and developer temperatures to simulate variations in radiographic quality due to inadequate processing conditions. Test films, produced using the four monitoring devices, were exposed and processed under identical conditions. The phantom bitewings were judged to have 'acceptable' quality when the optical density of that part of the film not showing calcified structures was within +/- 0.5 of that of the film processed under optimal conditions. The efficacy of the monitoring devices in indicating the adequacy of processing was assessed by a comparison of their readings with those made from the phantom bitewings. None of the monitoring devices was ideal for all the kilovoltage/film speed combinations tested, but the homemade device proved to be the most generally effective. We conclude that guidelines to dentists on radiographic quality assurance should include reference to and details of this simple device.

  14. Variability amongst radiographers in the categorization of clinical acceptability for digital trauma radiography

    NASA Astrophysics Data System (ADS)

    Decoster, Robin; Toomey, Rachel; Smits, Dirk; Mol, Harrie; Verhelle, Filip; Butler, Marie-Louise

    2016-03-01

    Introduction: Radiographers evaluate anatomical structures to judge clinical acceptability of a radiograph. Whether a radiograph is deemed acceptable for diagnosis or not depends on the individual decision of the radiographer. Individual decisions cause variation in the accepted image quality. To minimise these variations definitions of acceptability, such as in RadLex, were developed. On which criteria radiographers attribute a RadLex categories to radiographs is unknown. Insight into these criteria helps to further optimise definitions and reduce variability in acceptance between radiographers. Therefore, this work aims the evaluation of the correlation between the RadLex classification and the evaluation of anatomical structures, using a Visual Grading Analysis (VGA) Methods: Four radiographers evaluated the visibility of five anatomical structures of 25 lateral cervical spine radiographs on a secondary class display with a VGA. They judged clinical acceptability of each radiograph using RadLex. Relations between VGAS and RadLex category were analysed with Kendall's Tau correlation and Nagelkerke pseudo-R². Results: The overall VGA score (VGAS) and the RadLex score correlate (rτ= 0.62, p<0.01, R2=0.72) strongly. The observers' evaluation of contrast between bone, air (trachea) and soft tissue has low value in predicting (rτ=0.55, p<0.01, R2=0.03) the RadLex score. The reproduction of spinous processes (rτ=0.67, p<0.01, R2=0.31) and the evaluation of the exposure (rτ=0.65, p<0.01, R2=0.56) have a strong correlation with high predictive value for the RadLex score. Conclusion: RadLex scores and VGAS correlate positively, strongly and significantly. The predictive value of bony structures may support the use of these in the judgement of clinical acceptability. Considerable inter-observer variations in the VGAS within a certain RadLex category, suggest that observers use of observer specific cut

  15. Exploring the feasibility of traditional image querying tasks for industrial radiographs

    NASA Astrophysics Data System (ADS)

    Bray, Iliana E.; Tsai, Stephany J.; Jimenez, Edward S.

    2015-08-01

    Although there have been great strides in object recognition with optical images (photographs), there has been comparatively little research into object recognition for X-ray radiographs. Our exploratory work contributes to this area by creating an object recognition system designed to recognize components from a related database of radiographs. Object recognition for radiographs must be approached differently than for optical images, because radiographs have much less color-based information to distinguish objects, and they exhibit transmission overlap that alters perceived object shapes. The dataset used in this work contained more than 55,000 intermixed radiographs and photographs, all in a compressed JPEG form and with multiple ways of describing pixel information. For this work, a robust and efficient system is needed to combat problems presented by properties of the X-ray imaging modality, the large size of the given database, and the quality of the images contained in said database. We have explored various pre-processing techniques to clean the cluttered and low-quality images in the database, and we have developed our object recognition system by combining multiple object detection and feature extraction methods. We present the preliminary results of the still-evolving hybrid object recognition system.

  16. Direct measurement of the image displacement instability in a linear induction accelerator

    NASA Astrophysics Data System (ADS)

    Burris-Mog, T. J.; Ekdahl, C. A.; Moir, D. C.

    2017-06-01

    The image displacement instability (IDI) has been measured on the 20 MeV Axis I of the dual axis radiographic hydrodynamic test facility and compared to theory. A 0.23 kA electron beam was accelerated across 64 gaps in a low solenoid focusing field, and the position of the beam centroid was measured to 34.3 meters downstream from the cathode. One beam dynamics code was used to model the IDI from first principles, while another code characterized the effects of the resistive wall instability and the beam break-up (BBU) instability. Although the BBU instability was not found to influence the IDI, it appears that the IDI influences the BBU. Because the BBU theory does not fully account for the dependence on beam position for coupling to cavity transverse magnetic modes, the effect of the IDI is missing from the BBU theory. This becomes of particular concern to users of linear induction accelerators operating in or near low magnetic guide fields tunes.

  17. The relationship between operative and radiographic acetabular component orientation: which factors influence resultant cup orientation?

    PubMed

    Grammatopoulos, G; Pandit, H G; da Assunção, R; McLardy-Smith, P; De Smet, K A; Gill, H S; Murray, D W

    2014-10-01

    There is great variability in acetabular component orientation following hip replacement. The aims of this study were to compare the component orientation at impaction with the orientation measured on post-operative radiographs and identify factors that influence the difference between the two. A total of 67 hip replacements (52 total hip replacements and 15 hip resurfacings) were prospectively studied. Intra-operatively, the orientation of the acetabular component after impaction relative to the operating table was measured using a validated stereo-photogrammetry protocol. Post-operatively, the radiographic orientation was measured; the mean inclination/anteversion was 43° (sd 6°)/ 19° (sd 7°). A simulated radiographic orientation was calculated based on how the orientation would have appeared had an on-table radiograph been taken intra-operatively. The mean difference between radiographic and intra-operative inclination/anteversion was 5° (sd 5°)/ -8° (sd 8°). The mean difference between simulated radiographic and intra-operative inclination/anteversion, which quantifies the effect of the different way acetabular orientation is measured, was 3°/-6° (sd 2°). The mean difference between radiographic and simulated radiographic orientation inclination/anteversion, which is a manifestation of the change in pelvic position between component impaction and radiograph, was 1°/-2° (sd 7°). This study demonstrated that in order to achieve a specific radiographic orientation target, surgeons should implant the acetabular component 5° less inclined and 8° more anteverted than their target. Great variability (2 sd about ± 15°) in the post-operative radiographic cup orientation was seen. The two equally contributing causes for this are variability in the orientation at which the cup is implanted, and the change in pelvic position between impaction and post-operative radiograph. ©2014 The British Editorial Society of Bone & Joint Surgery.

  18. Radiographic Severity of Rheumatoid Arthritis in African-Americans: Results from the CLEAR Registry

    PubMed Central

    Bridges, S. Louis; Causey, Zenoria L.; Burgos, Paula I.; Huynh, B. Quynh N.; Hughes, Laura B.; Danila, Maria I.; van Everdingen, Amalia; Ledbetter, Stephanie; Conn, Doyt L.; Tamhane, Ashutosh; Westfall, Andrew O.; Jonas, Beth L.; Callahan, Leigh F.; Smith, Edwin A.; Brasington, Richard; Moreland, Larry W.; Alarcón, Graciela S.; van der Heijde, Désirée M.

    2010-01-01

    Objective To describe radiographic changes in African-Americans with rheumatoid arthritis (RA) from the CLEAR (Consortium for the Longitudinal Evaluation of African-Americans with Early Rheumatoid Arthritis) Registry, a multicenter observational study. Methods Self-declared African-American patients, were enrolled in CLEAR I, a longitudinal cohort of early RA (disease duration <2 years) from 2000 to 2005; or in CLEAR II, a cross-sectional cohort (any disease duration), from 2006 to the present. Demographic and clinical data were obtained, and sets of hand/wrist and foot radiographs were scored using the modified Sharp/van der Heijde scoring system. Results A total of 357 and 418 patients, respectively, have been enrolled into CLEAR I and CLEAR II. We report here an interim analysis of radiographic severity in these patients. For the CLEAR I cohort, 294 patients had a mean radiographic score of 2.89 at the baseline visit; 32.0% showed either erosions (25.9%) or joint space narrowing (JSN) (19.4%). At the 36-month visit the mean score was 5.65; 44.2% had erosions, 41.5% JSN and 55.4% had either. Among those patients without radiographic damage at baseline, 18.9% had progressed at the 36-month visit, compared to 57.1% of those with baseline damage (p<0.0001). For the CLEAR II cohort, 167 patients with RA of any duration, 65.3% exhibited joint erosions, 65.3% JSN and 74.8% exhibited either. The mean radiographic score was 33.42. Conclusion This is the largest radiographic study of African American RA patients. Damage occurs early in the disease and is associated with radiographic progression at 3 years of disease duration. The CLEAR Registry will provide a valuable resource for future analyses of genetic, clinical, and environmental factors associated with radiographic severity of RA in African-Americans. PMID:20461784

  19. Sacroplasty procedural extravasation with high viscosity bone cement: comparing the intraoperative long-axis versus short-axis techniques in osteoporotic cadavers.

    PubMed

    Miller, Jeffrey W; Diani, Art; Docsa, Steve; Ashton, Kristi; Sciamanna, Michele

    2017-09-01

    Percutaneous sacroplasty involves image-guided injection of bone cement for sacral insufficiency fractures to alleviate pain and facilitate mobility. Correct sacral placement of the cement and the risk of cement extravasation present procedural challenges. This study compares the occurrence, number, location, and surface area of high viscosity radiopaque bone cement extravasation via biplane fluoroscopy with Dyna CT between the fluoroscopically-guided intraoperative long-axis and short-axis sacroplasty techniques in osteoporotic cadavers. Ten osteoporotic cadavers underwent bilateral percutaneous instillation of VertaPlex HV High Viscosity Radiopaque Bone Cement. Long- and short-axis sacroplasty techniques were randomly assigned to zone 1 of the left or right sacral ala of each cadaver. Cement extravasation data were summarized by technique (long-axis vs short-axis) and time period (15-min and 3-hour post-procedure syngo DynaCT scan) in the form of point and CI estimates for the true proportions of cement extravasation. No procedural sacral extravasation differences were observed between the long-axis and short-axis sacroplasty techniques. There were no occurrences of intra-procedural or post-procedural cement extravasation at 15 min or 3 hours in association with either the long-axis sacroplasty technique or the short-axis sacroplasty technique. The long- and short-axis sacroplasty techniques, using high viscosity cement with careful post-procedural positioning, result in no occurrence of cement extravasation in porous osteoporotic cadaver bone. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  20. Correction of radiographic measurements of acetabular cup wear for variations in pelvis orientation.

    PubMed

    Derbyshire, Brian

    2018-03-01

    Radiographic measurement of two-dimensional acetabular cup wear is usually carried out on a series of follow-up radiographs of the patient's pelvis. Since the orientation of the pelvis might not be consistent at every X-ray examination, the resulting change in view of the wear plane introduces error into the linear wear measurement. This effect is amplified on some designs of cup in which the centre of the socket is several millimetres below the centre of the cup or circular wire marker. This study describes the formulation of a mathematical method to correct radiographic wear measurements for changes in pelvis orientation. A mathematical simulation of changes in cup orientation and wear vectors caused by pelvic tilt was used to confirm that the formulae corrected the wear exactly if the radiographic plane of the reference radiograph was parallel to the true plane of wear. An error analysis showed that even when the true wear plane was not parallel to the reference radiographic plane, the formulae could still provide a useful correction. A published correction formula was found to be ineffective.

  1. Correction of radiographic measurements of acetabular cup wear for variations in pelvis orientation

    PubMed Central

    Derbyshire, Brian

    2018-01-01

    Radiographic measurement of two-dimensional acetabular cup wear is usually carried out on a series of follow-up radiographs of the patient’s pelvis. Since the orientation of the pelvis might not be consistent at every X-ray examination, the resulting change in view of the wear plane introduces error into the linear wear measurement. This effect is amplified on some designs of cup in which the centre of the socket is several millimetres below the centre of the cup or circular wire marker. This study describes the formulation of a mathematical method to correct radiographic wear measurements for changes in pelvis orientation. A mathematical simulation of changes in cup orientation and wear vectors caused by pelvic tilt was used to confirm that the formulae corrected the wear exactly if the radiographic plane of the reference radiograph was parallel to the true plane of wear. An error analysis showed that even when the true wear plane was not parallel to the reference radiographic plane, the formulae could still provide a useful correction. A published correction formula was found to be ineffective. PMID:29473454

  2. High Variability of Observed Weight Bearing During Standing Foot and Ankle Radiographs.

    PubMed

    Miller, Christopher P; Ghorbanhoseini, Mohammad; Ehrlichman, Lauren K; Walley, Kempland C; Ghaheri, Azadeh; Kwon, John Y

    2017-06-01

    Weight-bearing radiographs are a critical component of evaluating foot and ankle pathology. An underlying assumption is that patients are placing 50% of their body weight on the affected foot during image acquisition. The accuracy of weight bearing during radiographs is unknown and, presumably, variable, which may result in uncertain ability of the resultant radiographs to appropriately portray the pathology of interest. Fifty subjects were tested. The percentage body weight through the foot of interest was measured at the moment of radiographic image acquisition. The subject was then instructed to bear "half [their] weight" prior to the next radiograph. The percentage body weight was calculated and compared to ideal 50% weight bearing. The mean percentage body weight in trial 1 and 2 was 45.7% ± 3.2% ( P = .012 compared to the 50% mark) and 49.2% ± 2.4%, respectively ( P = .428 compared to 50%). The mean absolute difference in percentage weight bearing compared to 50% in trials 1 and 2 was 9.3% ± 2.3% and 5.8% ± 1.8%, respectively ( P = .005). For trial 1, 18/50 subjects were within the "ideal" (45%-55%) range for weight bearing compared to 32/50 on trial 2 ( P = .005). In trial 1, 24/50 subjects had "appropriate" (>45%) weight bearing compared to 39/50 on trial 2 ( P = .002). There was substantial variability in the weight applied during radiograph acquisition. This study raises questions regarding the assumptions, reliability, and interpretation when evaluating weight-bearing radiographs. Level III, comparative study.

  3. Comparison between electromagnetic transponders and radiographic imaging for prostate localization: A pelvic phantom study with rotations and translations.

    PubMed

    Hamilton, Daniel G; McKenzie, Dean P; Perkins, Anne E

    2017-09-01

    The aim of this study was to evaluate the differences in target localization between Calypso ® , kV orthogonal imaging and cone-beam computed tomography (CBCT) for combined translations and rotations of an anthropomorphic pelvic phantom. The phantom was localized using all three systems in 50 different positions, with applied translational and rotational offsets randomly sampled from representative normal distributions of prostate motion. Lin's concordance correlation coefficient (ρc) and 95% confidence intervals were calculated to assess the agreement between the localization systems. Mean differences and difference vectors between the three systems were also calculated. Agreement between systems for lateral, vertical, and longitudinal translations was excellent, with ρc values of greater than 0.98 between all three systems in all axes. There was excellent agreement between the systems for rotations around the lateral axis (pitch) (ρc > 0.99), and around the vertical axis (yaw) (ρc > 0.97). However, somewhat poorer agreement for rotations around the longitudinal axis (roll) was observed, with the lowest correlation observed between Calypso and kV orthogonal imaging (ρc = 0.895). Mean differences between the phantom position reported by Calypso and the radiographic systems were less than 1 mm and 1° for all translations and rotations. The results for translations are consistent with the publications of previous authors. There is no comparable published data for rotations. While there is lower correlation between the three systems for roll than for the other angles, the mean differences in reported rotations are not clinically significant. © 2017 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine.

  4. Accuracy and precision of computer-assisted analysis of bone density via conventional and digital radiography in relation to dual-energy x-ray absorptiometry.

    PubMed

    Vaccaro, Calogero; Busetto, Roberto; Bernardini, Daniele; Anselmi, Carlo; Zotti, Alessandro

    2012-03-01

    To evaluate the precision and accuracy of assessing bone mineral density (BMD) by use of mean gray value (MGV) on digitalized and digital images of conventional and digital radiographs, respectively, of ex vivo bovine and equine bone specimens in relation to the gold-standard technique of dual-energy x-ray absorptiometry (DEXA). Left and right metatarsal bones from 11 beef cattle and right femurs from 2 horses. Bovine specimens were imaged by use of conventional radiography, whereas equine specimens were imaged by use of computed radiography (digital radiography). Each specimen was subsequently scanned by use of the same DEXA equipment. The BMD values resulting from each DEXA scan were paired with the MGVs obtained by use of software on the corresponding digitalized or digital radiographic image. The MGV analysis of digitalized and digital x-ray images was a precise (coefficient of variation, 0.1 and 0.09, respectively) and highly accurate method for assessing BMD, compared with DEXA (correlation coefficient, 0.910 and 0.937 for conventional and digital radiography, respectively). The high correlation between MGV and BMD indicated that MGV analysis may be a reliable alternative to DEXA in assessing radiographic bone density. This may provide a new, inexpensive, and readily available estimate of BMD.

  5. Stability of a dual-spin satellite with two dampers

    NASA Technical Reports Server (NTRS)

    Alfriend, K. T.; Hubert, C. H.

    1974-01-01

    The rotational stability of a dual-spin satellite consisting of a main body and a symmetric rotor, both spinning about a common axis, is investigated. The main body is equipped with a spring-mass damper, while a partially filled viscous ring damper is mounted on the rapidly spinning rotor. The effect of fluid motion on the rotational stability of the satellite is calculated, considering the fluid as a single particle moving in a tube with viscous damping. Time constants are obtained by solving approximate equations of motion for the nutation-synchronous and the spin-synchronous modes, and the results are found to agree well with the numerical integrations of the exact equations. A limit cycle may exist for some configurations; the nutation angle tends to increase in such cases.

  6. Vertical axis wind turbine airfoil

    DOEpatents

    Krivcov, Vladimir; Krivospitski, Vladimir; Maksimov, Vasili; Halstead, Richard; Grahov, Jurij Vasiljevich

    2012-12-18

    A vertical axis wind turbine airfoil is described. The wind turbine airfoil can include a leading edge, a trailing edge, an upper curved surface, a lower curved surface, and a centerline running between the upper surface and the lower surface and from the leading edge to the trailing edge. The airfoil can be configured so that the distance between the centerline and the upper surface is the same as the distance between the centerline and the lower surface at all points along the length of the airfoil. A plurality of such airfoils can be included in a vertical axis wind turbine. These airfoils can be vertically disposed and can rotate about a vertical axis.

  7. Modular off-axis solar concentrator

    DOEpatents

    Plesniak, Adam P; Hall, John C

    2015-01-27

    A solar concentrator including a housing defining a vertical axis and including a receiving wall connected to a reflecting wall to define an internal volume and an opening into the internal volume, wherein the reflecting wall defines at least one primary optical element, and wherein at least a portion of the reflecting wall includes a layer of reflective material, the housing further including a cover connected to the receiving wall and the reflecting wall to seal the opening, and at least one receiver mounted on the receiving wall such that a vertical axis of the receiver is disposed at a non-zero angle relative to the vertical axis of the housing, the receiver including at least one photovoltaic cell.

  8. Dual-Pump CARS Development and Application to Supersonic Combustion

    NASA Astrophysics Data System (ADS)

    Magnotti, Gaetano

    Successful design of hypersonic air-breathing engines requires new computational fluid dynamics (CFD) models for turbulence and turbulence-chemistry interaction in supersonic combustion. Unfortunately, not enough data are available to the modelers to develop and validate their codes, due to difficulties in taking measurements in such a harsh environment. Dual-pump coherent anti-Stokes Raman spectroscopy (CARS) is a non-intrusive, non-linear, laser-based technique that provides temporally and spatially resolved measurements of temperature and absolute mole fractions of N2, O2 and H2 in H2-air flames. A dual-pump CARS instrument has been developed to obtain measurements in supersonic combustion and generate databases for the CFD community. Issues that compromised previous attempts, such as beam steering and high irradiance perturbation effects, have been alleviated or avoided. Improvements in instrument precision and accuracy have been achieved. An axis-symmetric supersonic combusting coaxial jet facility has been developed to provide a simple, yet suitable flow to CFD modelers. The facility provides a central jet of hot "vitiated air" simulating the hot air entering the engine of a hypersonic vehicle flying at Mach numbers between 5 and 7. Three different silicon carbide nozzles, with exit Mach number 1, 1.6 and 2, are used to provide flows with the effects of varying compressibility. H2 co-flow is available in order to generate a supersonic combusting free jet. Dual-pump CARS measurements have been obtained for varying values of flight and exit Mach numbers at several locations. Approximately one million Dual-pump CARS single shots have been collected in the supersonic jet for varying values of flight and exit Mach numbers at several locations. Data have been acquired with a H2 co-flow (combustion case) or a N 2 co-flow (mixing case). Results are presented and the effects of the compressibility and of the heat release are discussed.

  9. Dual modality surgical guidance of non-palpable breast lesions

    NASA Astrophysics Data System (ADS)

    Judy, Patricia Goodale

    Although breast conserving therapy has some advantages over the traditional mastectomy procedure, the biggest disadvantage is the chance of local re-occurrence in which a second surgery is often required. Adequate surgical removal of breast tumors requires accurate tumor localization in order to ensure a balance between optimal cosmetic results and minimization of the risk for local re-occurrence. These challenges have motivated the search for alternative, more accurate methods for intraoperative localization of non-palpable breast lesions. The overall goal of this project was to develop an innovative technique for radioguided localization of non-palpable breast lesions that is more accurate, easier for the breast surgeon, and more comfortable for the patient than the current practice of wire localization. The technique uses a dual modality breast imaging system to place a marker composed of radiolabeled albumin (99mTc-MAA or 111ln-MAA) into the lesion. Preliminary studies were made to evaluate the localization accuracy of the system, which showed that the dual modality breast scanner is capable of accurate 3-dimensional localization using either X-ray or gamma ray imaging. A 3-axis needle positioning system was built and integrated into the dual modality breast scanner and its accuracy tested. A pilot clinical trial to evaluate the dual-modality surgical guidance technique was designed and preliminary clinical data collected. Detailed results were presented on the first three subjects; although a total of seven subjects have been recruited to the study to date. So far, it has been demonstrated that the radioguided surgery technique can be performed with approximately 10 times less radiomarker activity than is currently being used by other researchers employing 99mTc-MAA as a radiomarker, while maintaining comparable localization accuracy. Although the DMSG technique has not been tested in a large cohort of subjects, the preliminary data on the first few are

  10. Utility of plain radiographs in detecting traumatic injuries of the cervical spine in children.

    PubMed

    Nigrovic, Lise E; Rogers, Alexander J; Adelgais, Kathleen M; Olsen, Cody S; Leonard, Jeffrey R; Jaffe, David M; Leonard, Julie C

    2012-05-01

    The objective of this study was to estimate the sensitivity of plain radiographs in identifying bony or ligamentous cervical spine injury in children. We identified a retrospective cohort of children younger than 16 years with blunt trauma-related bony or ligamentous cervical spine injury evaluated between 2000 and 2004 at 1 of 17 hospitals participating in the Pediatric Emergency Care Applied Research Network. We excluded children who had a single or undocumented number of radiographic views or one of the following injuries types: isolated spinal cord injury, spinal cord injury without radiographic abnormalities, or atlantoaxial rotary subluxation. Using consensus methods, study investigators reviewed the radiology reports and assigned a classification (definite, possible, or no cervical spine injury) as well as film adequacy. A pediatric neurosurgeon, blinded to the classification of the radiology reports, reviewed complete case histories and assigned final cervical spine injury type. We identified 206 children who met inclusion criteria, of which 127 had definite and 41 had possible cervical spine injury identified by plain radiograph. Of the 186 children with adequate cervical spine radiographs, 168 had definite or possible cervical spine injury identified by plain radiograph for a sensitivity of 90% (95% confidence interval, 85%-94%). Cervical spine radiographs did not identify the following cervical spine injuries: fracture (15 children) and ligamentous injury alone (3 children). Nine children with normal cervical spine radiographs presented with 1 or more of the following: endotracheal intubation (4 children), altered mental status (5 children), or focal neurologic findings (5 children). Plain radiographs had a high sensitivity for cervical spine injury in our pediatric cohort.

  11. A method for the geometric and densitometric standardization of intraoral radiographs

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Duckworth, J.E.; Judy, P.F.; Goodson, J.M.

    1983-07-01

    The interpretation of dental radiographs for the diagnosis of periodontal disease conditions poses several difficulties. These include the inability to adequately reproduce the projection geometry and optical density of the exposures. In order to improve the ability to extract accurate quantitative information from a radiographic survey of periodontal status, a method was developed which provided for consistent reproduction of both geometric and densitometric exposure parameters. This technique employed vertical bitewing projections in holders customized to individual segments of the dentition. A copper stepwedge was designed to provide densitometric standardization, and wire markers were included to permit measurement of angular variation.more » In a series of 53 paired radiographs, measurement of alveolar crest heights was found to be reproducible within approximately 0.1 mm. This method provided a full mouth radiographic survey using seven films, each complete with internal standards suitable for computer-based image processing.« less

  12. Neutron radiographic viewing system

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The design, development and application of a neutron radiographic viewing system for use in nondestructive testing applications is considered. The system consists of a SEC vidicon camera, neutron image intensifier system, disc recorder, and TV readout. Neutron bombardment of the subject is recorded by an image converter and passed through an optical system into the SEC vidicon. The vidicon output may be stored, or processed for visual readout.

  13. Modern dual-mobility cup implanted with an uncemented stem: about 100 cases with 12-year follow-up.

    PubMed

    Philippot, Remi; Meucci, Jean Francois; Boyer, Bertrand; Farizon, Frederic

    2013-09-01

    We report the results of a 12-year follow-up retrospective series of 100 total hip arthroplasties using cementless, press-fit, dual-mobility acetabular cups. The aim of our study was to evaluate the clinical and radiographic results of this acetabular cup at last follow-up. This continuous and homogeneous series included 100 primary total hip arthroplasties performed during the year 2000. The THA combined a Corail® stem (Corail®, Depuy, Warsaw, IN) with a stainless steel Novae Sunfit® (Serf, Decines, France) acetabular cup. Fifteen patients died and 2 were lost to follow-up. Two cases of early dislocation were observed, and 3 cases of aseptic loosening of the acetabular component were reported. The mean stem subsidence was 0.71 mm, the mean craniopodal acetabular migration was 1.37 mm, and the mean medio-lateral acetabular migration was 1.52 mm. The 12-year survivorship is comparable to the data from the literature. The low dislocation rate at 12 years confirms the long-term, high stability of dual mobility, which should be recommended in primary THA for patients at risk for postoperative instability. The absence of true intraprosthetic dislocation events at 12-year follow-up provides evidence of the good quality of the latest generation of polyethylene liners and the necessity of combining thin-mirror, polished femoral necks with dual-mobility cups.

  14. Imaging of juvenile idiopathic arthritis. Part I: Clinical classifications and radiographs

    PubMed Central

    Matuszewska, Genowefa; Gietka, Piotr; Płaza, Mateusz; Walentowska-Janowicz, Marta

    2016-01-01

    Juvenile idiopathic arthritis is the most common autoimmune systemic disease of the connective tissue affecting individuals at the developmental age. Radiography is the primary modality employed in the diagnostic imaging in order to identify changes typical of this disease entity and rule out other bone-related pathologies, such as neoplasms, posttraumatic changes, developmental defects and other forms of arthritis. The standard procedure involves the performance of comparative joint radiographs in two planes. Radiographic changes in juvenile idiopathic arthritis are detected in later stages of the disease. Bone structures are assessed in the first place. Radiographs can also indirectly indicate the presence of soft tissue inflammation (i.e. in joint cavities, sheaths and bursae) based on swelling and increased density of the soft tissue as well as dislocation of fat folds. Signs of articular cartilage defects are also seen in radiographs indirectly – based on joint space width changes. The first part of the publication presents the classification of juvenile idiopathic arthritis and discusses its radiographic images. The authors list the affected joints as well as explain the spectrum and specificity of radiographic signs resulting from inflammatory changes overlapping with those caused by the maturation of the skeletal system. Moreover, certain dilemmas associated with the monitoring of the disease are reviewed. The second part of the publication will explain issues associated with ultrasonography and magnetic resonance imaging, which are more and more commonly applied in juvenile idiopathic arthritis for early detection of pathological features as well as the disease complications. PMID:27679726

  15. Brazilian young dental practitioners' use and acceptance of digital radiographic examinations.

    PubMed

    Rovaris, Karla; de Faria Vasconcelos, Karla; do Nascimento, Eduarda Helena Leandro; Oliveira, Matheus Lima; Freitas, Deborah Queiroz; Haiter-Neto, Francisco

    2016-12-01

    The aim of this study was to investigate the use and acceptance of digital radiographic examinations by Brazilian dental practitioners in daily practice and to evaluate the advances that have occurred over the past 5 years. Dental practitioners enrolled in extension courses at the Piracicaba Dental School, University of Campinas, Brazil, responded to a self-administered questionnaire in the years 2011 and 2015. They were asked about sociodemographic factors and their knowledge and use of digital radiographic examinations. Descriptive analysis was performed, as well as the chi-square and Fisher exact tests, with a significance level of 5% (α=0.05). A total of 181 participants responded to the questionnaire in the years 2011 and 2015. Most of the respondents worked in private practice, had graduated within the last 5 years, and were between 20 and 30 years old. In 2011, 55.6% of respondents reported having ever used digital radiographic examinations, while in 2015 this number increased significantly to 85.4% (p<.0001), out of which 71.4% preferred it to conventional images. Moreover, 21.4% of respondents reported having used digital radiographic examinations for more than 3 years. A significant increase in use of intraoral digital radiography (p=0.0316) was observed in 2015. In both years, image quality and high cost were indicated, respectively, as the main advantage and disadvantage of digital radiographic examinations. This study showed that digital radiology has become more common in Brazil over the past 5 years. Most of the Brazilian dental practitioners evaluated in 2015 used digital radiographic examinations.

  16. Awareness of radiographic guidelines for low back pain: a survey of Australian chiropractors.

    PubMed

    Jenkins, Hazel J

    2016-01-01

    Chiropractors have been shown to refer for lumbar radiography in clinical scenarios inconsistent with the current clinical guidelines for low back pain. It is unknown whether this is due to lack of adherence with known guidelines or a lack of awareness of relevant guidelines. Therefore, the aim of this study is to determine Australian chiropractors' awareness of, and reported adherence to, radiographic guidelines for low back pain. Demographic, chiropractic practice and radiographic usage characteristics will be investigated for association with poor guideline adherence. An online survey was distributed to Australian chiropractors from July to September, 2014. Survey questions assessed demographic, chiropractic practice and radiographic usage characteristics, awareness of radiographic guidelines for low back pain and the level of agreement with current guidelines. Results were analysed with descriptive statistics and logistic regression analysis. There were 480 surveys completed online. Only 49.6 % (95 % confidence interval (95 % CI): 44.9, 54.4) reported awareness of radiographic guidelines for low back pain. Chiropractors reported a likelihood of referring for radiographs for low back pain: in new patients (47.6 % (95 % CI: 42.9, 52.3)); to confirm biomechanical pathologies (69.0 % (95 % CI: 64.5, 73.1)); to perform biomechanical analysis (37.5 % (95 % CI: 33.1, 42.0)); or to screen for contraindications (39.4 % (95 % CI: 35.0, 44.0)). Chiropractors agreed that radiographs for low back pain could be useful for: acute low back pain (54.0 % (95 % CI: 49.2, 58.7)); screening for contraindications (55.8 % (95 % CI: 51.0, 60.5)); or to confirm diagnosis and direct treatment (61.3 % (95 % CI: 56.5, 65.9)). Poorer adherence to current guidelines was seen if the chiropractor referred to in-house radiographic facilities, practiced a technique other than diversified technique or was unaware or unsure of current radiographic guidelines for low back pain. Only 50

  17. Distortion definition and correction in off-axis systems

    NASA Astrophysics Data System (ADS)

    Da Deppo, Vania; Simioni, Emanuele; Naletto, Giampiero; Cremonese, Gabriele

    2015-09-01

    Off-axis optical configurations are becoming more and more used in a variety of applications, in particular they are the most preferred solution for cameras devoted to Solar System planets and small bodies (i.e. asteroids and comets) study. Off-axis designs, being devoid of central obstruction, are able to guarantee better PSF and MTF performance, and thus higher contrast imaging capabilities with respect to classical on-axis designs. In particular they are suitable for observing extended targets with intrinsic low contrast features, or scenes where a high dynamical signal range is present. Classical distortion theory is able to well describe the performance of the on-axis systems, but it has to be adapted for the off-axis case. A proper way to deal with off-axis distortion definition is thus needed together with dedicated techniques to accurately measure and hence remove the distortion effects present in the acquired images. In this paper, a review of the distortion definition for off-axis systems will be given. In particular the method adopted by the authors to deal with the distortion related issues (definition, measure, removal) in some off-axis instruments will be described in detail.

  18. Usefulness of intraoperative radiographs in reducing errors of cup placement and leg length during total hip arthroplasty.

    PubMed

    Wind, Michael A; Morrison, J Craig; Christie, Michael J

    2013-11-01

    Traditional methods of component placement during total hip arthroplasty (THA) can lead to errors in cup abduction angle and leg length. Intraoperative radiographs were used to assess and correct errors during surgery in a consecutive series of 278 THAs performed by a single surgeon. After exclusions, 262 cases were available for cup abduction angle assessment and 224 for leg length discrepancy (LLD) assessment. Components were initially placed in a position determined as appropriate by the surgeon. Intraoperative radiographs were taken and appropriate corrections made. Postoperative radiographs were assessed at 6 weeks. Mean abduction angle on intraoperative radiographs was 39.6°±5.9° versus 38.6°±4.1° on postoperative radiographs. Thirty-eight cups were outside the target abduction range on intraoperative radiographs versus 4 on postoperative radiographs. Mean LLD was 3.7 mm ± 3.6 mm on intraoperative radiographs and 2.5 mm ± 2.7 mm on postoperative radiographs. Use of intraoperative radiographs is a valid, useful technique for minimizing errors in THA.

  19. Chest radiographic characteristics of community-acquired Legionella pneumonia in the elderly.

    PubMed

    Zhang, Zhigang; Liu, Xinmin; Chen, Luzeng; Qiu, Jianxing

    2014-01-01

    Legionella is an important community-acquired pneumonia pathogen. Although the elderly are especially susceptible to Legionella, few studies have looked at comparative radiographic features of Legionella pneumonia in this population. The aim of this study was to explore the chest radiographic characteristics of community-acquired Legionella pneumonia in the elderly. Serial chest radiographs obtained in 34 patients hospitalized with serologically proven Legionella pneumonia were retrospectively reviewed. Chest X-ray features of an aged group of ≥ 65 years were assessed and compared with a non-aged group of <65 years old with regard to initial patterns and distributions of pulmonary abnormalities, accompanying signs, and progression. The most common initial presentation was a patchy alveolar infiltrate involving a single lobe, most often the lower lobe. There was no middle or lingular lobe involvement in the aged group patients, but bilateral pleural effusion was significantly more common in this group. In the aged group patients, radiographic progression following adequate therapy, despite a clinical response, was more often noted and the radiographs were less likely to have returned to the premorbid state at discharge, but the differences were not significant between the two groups. The discrepancy between imaging findings and clinical symptoms seems more prominent in community-acquired Legionella pneumonia in the elderly.

  20. Nurses in OR are more assertive than radiographers.

    PubMed

    Johnson, L

    1993-01-01

    This study investigated two hypotheses: that there is a positive correlation between assertiveness and self-esteem, and that nurses rate lower than non-nurses on the constructs. A self-report survey incorporating scales for general assertiveness, situationally-specific assertiveness, global self-esteem and differentiated self-esteem was utilised. For the sample of 83 operating room nurses and 81 radiographers, correlations significant at the p < .001 level between the respective scales supported the first hypothesis. Analysis of variance yielded no significant differences between the two groups on either self-esteem measures or general assertiveness, with the nurses scoring significantly higher than radiographers on the situationally-specific assertiveness scale. Findings challenge the stereotype of the 'shrinking violet' nurse. Additional analysis revealed that the power component of differentiated self-esteem had a higher correlation with global self-esteem and with both assertiveness measures than any other component. Further, the operating room nurses were significantly more power-oriented than radiographers. The pre-eminence of power in the findings suggests that assertiveness and self-esteem are issues relating to the empowerment of nurses.

  1. Dual Protection and Dual Methods in Women Living with HIV: The Brazilian Context

    PubMed Central

    Barbosa, Regina María; Pinho, Adriana de Araujo

    2013-01-01

    The cooccurrence of HIV and unintended pregnancy has prompted a body of work on dual protection, the simultaneous protection against HIV and unintended pregnancy. This study examines dual protection and dual methods as a risk-reduction strategy for women living with HIV. Data are from a cross-sectional sample of HIV-positive women attended in Specialized STI/AIDS Public Health Service Clinics in 13 municipalities from all five regions of Brazil 2003-2004 (N = 834). Descriptive techniques and logistic regression were used to examine dual protection among women living with HIV. We expand the definition of dual protection to include consistent condom use and reversible/irreversible contraceptive methods, we test the dual methods hypothesis that women who use dual methods will use condoms less consistently than women who use only condoms, and we identify predictors of dual protection. Dual protection is common in our sample. Women who use dual methods have lower odds of consistent condom use than women who only use condoms. Among dual method users, we find that women who use an irreversible method use condoms more consistently than women who use a reversible method. Women on ART and with an HIV-serodiscordant partner have greater odds of consistent condom use than their counterparts. PMID:26316959

  2. Prediction of age and gender using digital radiographic method: A retrospective study.

    PubMed

    Poongodi, V; Kanmani, R; Anandi, M S; Krithika, C L; Kannan, A; Raghuram, P H

    2015-08-01

    To investigate age, sex based on gonial angle, width and breadth of the ramus of the mandible by digital orthopantomograph. A total of 200 panoramic radiographic images were selected. The age of the individuals ranged between 4 and 75 years of both the gender - males (113) and females (87) and selected radiographic images were measured using KLONK image measurement software tool with linear, angular measurement. The investigated radiographs were collected from the records of SRM Dental College, Department of Oral Medicine and Radiology. Radiographs with any pathology, facial deformities, if no observation of mental foramen, congenital deformities, magnification, and distortion were excluded. Mean, median, standard deviation, derived to check the first and third quartile, linear regression is used to check age and gender correlation with angle of mandible, height and width of the ramus of mandible. The radiographic method is a simpler and cost-effective method of age identification compared with histological and biochemical methods. Mandible is strongest facial bone after the skull, pelvic bone. It is validatory to predict age and gender by many previous studies. Radiographic and tomographic images have become an essential aid for human identification in forensic dentistry forensic dentists can choose the most appropriate one since the validity of age and gender estimation crucially depends on the method used and its proper application.

  3. Actuator assembly including a single axis of rotation locking member

    DOEpatents

    Quitmeyer, James N.; Benson, Dwayne M.; Geck, Kellan P.

    2009-12-08

    An actuator assembly including an actuator housing assembly and a single axis of rotation locking member fixedly attached to a portion of the actuator housing assembly and an external mounting structure. The single axis of rotation locking member restricting rotational movement of the actuator housing assembly about at least one axis. The single axis of rotation locking member is coupled at a first end to the actuator housing assembly about a Y axis and at a 90.degree. angle to an X and Z axis providing rotation of the actuator housing assembly about the Y axis. The single axis of rotation locking member is coupled at a second end to a mounting structure, and more particularly a mounting pin, about an X axis and at a 90.degree. angle to a Y and Z axis providing rotation of the actuator housing assembly about the X axis. The actuator assembly is thereby restricted from rotation about the Z axis.

  4. Radiographic identification of the anterior and posterior root attachments of the medial and lateral menisci.

    PubMed

    James, Evan W; LaPrade, Christopher M; Ellman, Michael B; Wijdicks, Coen A; Engebretsen, Lars; LaPrade, Robert F

    2014-11-01

    Anatomic root placement is necessary to restore native meniscal function during meniscal root repair. Radiographic guidelines for anatomic root placement are essential to improve the accuracy and consistency of anatomic root repair and to optimize outcomes after surgery. To define quantitative radiographic guidelines for identification of the anterior and posterior root attachments of the medial and lateral menisci on anteroposterior (AP) and lateral radiographic views. Descriptive laboratory study. The anterior and posterior roots of the medial and lateral menisci were identified in 12 human cadaveric specimens (average age, 51.3 years; age range, 39-65 years) and labeled using 2-mm radiopaque spheres. True AP and lateral radiographs were obtained, and 2 raters independently measured blinded radiographs in relation to pertinent landmarks and radiographic reference lines. On AP radiographs, the anteromedial and posteromedial roots were, on average, 31.9 ± 5.0 mm and 36.3 ± 3.5 mm lateral to the edge of the medial tibial plateau, respectively. The anterolateral and posterolateral roots were, on average, 37.9 ± 5.2 mm and 39.3 ± 3.8 mm medial to the edge of the lateral tibial plateau, respectively. On lateral radiographs, the anteromedial and anterolateral roots were, on average, 4.8 ± 3.7 mm and 20.5 ± 4.3 mm posterior to the anterior margin of the tibial plateau, respectively. The posteromedial and posterolateral roots were, on average, 18.0 ± 2.8 mm and 19.8 ± 3.5 mm anterior to the posterior margin of the tibial plateau, respectively. The intrarater and interrater intraclass correlation coefficients (ICCs) were >0.958, demonstrating excellent reliability. The meniscal root attachment sites were quantitatively and reproducibly defined with respect to anatomic landmarks and superimposed radiographic reference lines. The high ICCs indicate that the measured radiographic relationships are a consistent means for evaluating meniscal root positions. This study

  5. Conical Fourier shell correlation applied to electron tomograms.

    PubMed

    Diebolder, C A; Faas, F G A; Koster, A J; Koning, R I

    2015-05-01

    The resolution of electron tomograms is anisotropic due to geometrical constraints during data collection, such as the limited tilt range and single axis tilt series acquisition. Acquisition of dual axis tilt series can decrease these effects. However, in cryo-electron tomography, to limit the electron radiation damage that occurs during imaging, the total dose should not increase and must be fractionated over the two tilt series. Here we set out to determine whether it is beneficial fractionate electron dose for recording dual axis cryo electron tilt series or whether it is better to perform single axis acquisition. To assess the quality of tomographic reconstructions in different directions here we introduce conical Fourier shell correlation (cFSCe/o). Employing cFSCe/o, we compared the resolution isotropy of single-axis and dual-axis (cryo-)electron tomograms using even/odd split data sets. We show that the resolution of dual-axis simulated and cryo-electron tomograms in the plane orthogonal to the electron beam becomes more isotropic compared to single-axis tomograms and high resolution peaks along the tilt axis disappear. cFSCe/o also allowed us to compare different methods for the alignment of dual-axis tomograms. We show that different tomographic reconstruction programs produce different anisotropic resolution in dual axis tomograms. We anticipate that cFSCe/o can also be useful for comparisons of acquisition and reconstruction parameters, and different hardware implementations. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Supply and demand for radiographers in Lithuania: a prognosis for 2012-2030.

    PubMed

    Vanckaviciene, Aurika; Starkiene, Liudvika; Macijauskiene, Jūrate

    2014-07-01

    This is the first ever study on the planning of the supply and demand for radiographers in Lithuania. The aim of this study was to analyze the supply and demand for radiographers in the labor market with respect to their number, structure, and services, and to provide a prognosis for the period of 2012-2030. Supply was calculated using two scenarios with differing duration of studies, annual student drop-out rates, rates of failure to start working, the annual number of new entrants into the labor market, and emigration rates. Annual mortality rates, the number of first-year students, and retirement rates were evaluated equally in both scenarios. Two projections of the demand for radiographers, based on the population's differing (by age and gender), need for outpatient radiology services, computed tomography, and magnetic resonance scans. Subsequently, the supply and demand scenarios were compared. Evaluation of the perspective supply and demand scenarios - which are the most probable - revealed a gap forming during the analyzed period, the predicted specialist shortage will reach 0.13 full-time equivalents per 10,000 population, and in 2030-0.37 full-time equivalents per 10,000 population. Considering the changes in education of radiographers, the socio-demographic characteristics of the staff, and the increasing need for radiographers' services, the supply of radiographers during the next two decades will be insufficient. To meet the forecasted demand for radiographers in the perspective scenario, the number of students choosing this specialty from 2013 on should increase by up to 30%. Copyright © 2014 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

  7. 42 CFR 37.45 - Protection against radiation emitted by radiographic equipment.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Protection against radiation emitted by radiographic equipment. 37.45 Section 37.45 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN....45 Protection against radiation emitted by radiographic equipment. Except as otherwise specified in...

  8. Skeletal maturity determination from hand radiograph by model-based analysis

    NASA Astrophysics Data System (ADS)

    Vogelsang, Frank; Kohnen, Michael; Schneider, Hansgerd; Weiler, Frank; Kilbinger, Markus W.; Wein, Berthold B.; Guenther, Rolf W.

    2000-06-01

    Derived from a model based segmentation algorithm for hand radiographs proposed in our former work we now present a method to determine skeletal maturity by an automated analysis of regions of interest (ROI). These ROIs including the epiphyseal and carpal bones, which are most important for skeletal maturity determination, can be extracted out of the radiograph by knowledge based algorithms.

  9. Digital processing of radiographic images

    NASA Technical Reports Server (NTRS)

    Bond, A. D.; Ramapriyan, H. K.

    1973-01-01

    Some techniques are presented and the software documentation for the digital enhancement of radiographs. Both image handling and image processing operations are considered. The image handling operations dealt with are: (1) conversion of format of data from packed to unpacked and vice versa; (2) automatic extraction of image data arrays; (3) transposition and 90 deg rotations of large data arrays; (4) translation of data arrays for registration; and (5) reduction of the dimensions of data arrays by integral factors. Both the frequency and the spatial domain approaches are presented for the design and implementation of the image processing operation. It is shown that spatial domain recursive implementation of filters is much faster than nonrecursive implementations using fast fourier transforms (FFT) for the cases of interest in this work. The recursive implementation of a class of matched filters for enhancing image signal to noise ratio is described. Test patterns are used to illustrate the filtering operations. The application of the techniques to radiographic images of metallic structures is demonstrated through several examples.

  10. Outcomes of Patellofemoral Arthroplasty Based on Radiographic Severity.

    PubMed

    deDeugd, Casey M; Pareek, Ayoosh; Krych, Aaron J; Cummings, Nancy M; Dahm, Diane L

    2017-04-01

    Patellofemoral arthroplasty (PFA) is increasingly performed for symptomatic patellofemoral arthritis. The purpose of this study was to evaluate the outcomes of PFA based on preoperative radiographic severity of patellofemoral arthritis. All patients who underwent PFA for isolated patellofemoral arthritis between 2002 and 2013 and had undergone preoperative magnetic resonance imaging were identified. Radiographic severity of patellofemoral arthritis was classified according to the Iwano classification system. Groups were divided between mild (grade 0-I) and moderate to severe (grade II-IV) patellofemoral arthritis. Clinical outcomes were evaluated using the Knee Society scores (KSS), University of California at Los Angeles (UCLA) and Tegner scores. Seventy-five knees in 55 patients met inclusion criteria. Mean age was 51 years (range, 36 to 81), and mean follow-up was 3 years (range, 2 to 10). All patients had grade IV patellofemoral chondromalacia and/or significant subchondral cyst formation and edema on magnetic resonance imaging. On plain radiographs, there were no patients with Iwano grade 0, 21 grade I, 15 grade II, 21 grade III, and 18 grade IV patellofemoral arthritis. There was significantly more improvement in KSS pain (P = .046), KSS function (P = .02), University of California at Los Angeles (UCLA) (P = .046) and Tegner (P = .008) scores in the Iwano grade II-IV group vs the Iwano grade I group. Patient-reported pain quality improved significantly more following PFA in the grade II-IV group (P = .04). Patients with evidence of mild patellofemoral arthritis on plain radiographs demonstrated less improvement in pain and function after PFA than those with more advanced patellofemoral arthritis. Caution should be used when considering PFA for patients with minimal radiographic evidence of patellofemoral arthritis. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Effect of Relative Marker Movement on the Calculation of the Foot Torsion Axis Using a Combined Cardan Angle and Helical Axis Approach

    PubMed Central

    Graf, Eveline S.; Wright, Ian C.; Stefanyshyn, Darren J.

    2012-01-01

    The two main movements occurring between the forefoot and rearfoot segment of a human foot are flexion at the metatarsophalangeal joints and torsion in the midfoot. The location of the torsion axis within the foot is currently unknown. The purpose of this study was to develop a method based on Cardan angles and the finite helical axis approach to calculate the torsion axis without the effect of flexion. As the finite helical axis method is susceptible to error due to noise with small helical rotations, a minimal amount of rotation was defined in order to accurately determine the torsion axis location. Using simulation, the location of the axis based on data containing noise was compared to the axis location of data without noise with a one-sample t-test and Fisher's combined probability score. When using only data with helical rotation of seven degrees or more, the location of the torsion axis based on the data with noise was within 0.2 mm of the reference location. Therefore, the proposed method allowed an accurate calculation of the foot torsion axis location. PMID:22666303

  12. Evaluation of radiographic, computed tomographic, and cadaveric anatomy of the head of boa constrictors.

    PubMed

    Banzato, Tommaso; Russo, Elisa; Di Toma, Anna; Palmisano, Giuseppe; Zotti, Alessandro

    2011-12-01

    To evaluate the radiographic, computed tomographic (CT), and cadaveric anatomy of the head of boa constrictors. 4 Boa constrictor imperator cadavers. Cadavers weighed 3.4 to 5.6 kg and had a body length ranging from 189 to 221 cm. Radiographic and CT images were obtained with a high-detail screen-film combination, and conventional CT was performed with a slice thickness of 1.5 mm. Radiographic images were obtained in ventrodorsal, dorsoventral, and left and right laterolateral recumbency; CT images were obtained with the animals positioned in ventral recumbency directly laying on a plastic support. At the end of the radiographic and CT imaging session, 2 heads were sectioned following a stratigraphic approach; the other 2, carefully maintained in the same position on the plastic support, were moved into a freezer (-20°C) until completely frozen and then sectioned into 3-mm slices, respecting the imaging protocol. The frozen sections were cleaned and then photographed on each side. Anatomic structures were identified and labeled on gross anatomic images and on the corresponding CT or radiographic image with the aid of available literature. Radiographic and CT images provided high detail for visualization of bony structures; soft tissues were not easily identified on radiographic and CT images. Results provide an atlas of stratigraphic and cross-sectional gross anatomy and radiographic and CT anatomy of the heads of boa constrictors that might be useful in the interpretation of any imaging modality in this species.

  13. Interphalangeal Osteoarthritis Radiographic Simplified (iOARS) score: a radiographic method to detect osteoarthritis of the interphalangeal finger joints based on its histopathological alterations.

    PubMed

    Sunk, Ilse-Gerlinde; Amoyo-Minar, Love; Stamm, Tanja; Haider, Stefanie; Niederreiter, Birgit; Supp, Gabriela; Soleiman, Afschin; Kainberger, Franz; Smolen, Josef S; Bobacz, Klaus

    2014-11-01

    To develop a radiographic score for assessment of hand osteoarthritis (OA) that is based on histopathological alterations of the distal (DIP) and proximal (PIP) interphalangeal joints. DIP and PIP joints were obtained from corpses (n=40). Plain radiographies of these joints were taken. Joint samples were prepared for histological analysis; cartilage damage was graded according to the Mankin scoring system. A 2×2 Fisher's exact test was applied to define those radiographic features most likely to be associated with histological alterations. Receiver operating characteristic curves were analysed to determine radiographic thresholds. Intraclass correlation coefficients (ICC) estimated intra- and inter-reader variability. Spearman's correlation was applied to examine the relationship between our score and histopathological changes. Differences between groups were determined by a Student's t test. The Interphalangeal Osteoarthritis Radiographic Simplified (iOARS) score is presented. The score is based on histopathological changes of DIP and PIP joints and follows a simple dichotomy whether OA is present or not. The iOARS score relies on three equally ranked radiographic features (osteophytes, joint space narrowing and subchondral sclerosis). For both DIP and PIP joints, the presence of one x-ray features reflects interphalangeal OA. Sensitivity and specificity for DIP joints were 92.3% and 90.9%, respectively, and 75% and 100% for PIP joints. All readers were able to reproduce their own readings in DIP and PIP joints after 4 weeks. The overall agreement between the three readers was good; ICCs ranged from 0.945 to 0.586. Additionally, outcomes of the iOARS score in a hand OA cohort revealed a higher prevalence of interphalangeal joint OA compared with the Kellgren and Lawrence score. The iOARS score is uniquely based on histopathological alterations of the interphalangeal joints in order to reliably determine OA of the DIP and PIP joints radiographically. Its high

  14. Two-axis angular effector

    DOEpatents

    Vaughn, Mark R.; Robinett, III, Rush D.; Phelan, John R.; Van Zuiden, Don M.

    1997-01-21

    A new class of coplanar two-axis angular effectors. These effectors combine a two-axis rotational joint analogous to a Cardan joint with linear actuators in a manner to produce a wider range of rotational motion about both axes defined by the joint. This new class of effectors also allows design of robotic manipulators having very high strength and efficiency. These effectors are particularly suited for remote operation in unknown surroundings, because of their extraordinary versatility. An immediate application is to the problems which arise in nuclear waste remediation.

  15. Fluoroscopic and radiographic evaluation of tracheal collapse in dogs: 62 cases (2001-2006).

    PubMed

    Macready, Dawn M; Johnson, Lynelle R; Pollard, Rachel E

    2007-06-15

    To compare the use of radiography and fluoroscopy for detection and grading of tracheal collapse in dogs. Retrospective case series. Animals-62 dogs with tracheal collapse. For each dog, tracheal collapse was confirmed fluoroscopically and lateral cervical and thoracic radiographic views were reviewed. A board-certified radiologist (who was unaware of the dogs' clinical history) evaluated the cervical, thoracic inlet, thoracic, carinal, and main stem bronchial regions in all fluoroscopic videos and radiographic images for evidence of collapse. Cervical, thoracic inlet, thoracic, and carinal regions in both radio-graphic and fluoroscopic studies were graded for collapse (0%, 25%, 50%, 75%, or 100% decrease in diameter). Lateral cervical and thoracic radiographic images were available for 54 dogs, and inspiratory and expiratory lateral cervical and thoracic radiographic images were available for 8 dogs. For detection of tracheal collapse, assessment of radiographic views was sensitive and had the best negative predictive value in the cervical and thoracic inlet regions. Assessment of radiographic views was most specific and had the best positive predictive value in the thoracic inlet, thoracic, carina, and main stem bronchial regions. Radiography underestimated the degree of collapse in all areas. Review of inspiratory and expiratory views improved the accuracy of radiography for tracheal collapse diagnosis only slightly. Compared with fluoroscopy, radiography underestimated the frequency and degree of tracheal collapse. However, radiography appears to be useful for screening dogs with potential tracheal collapse.

  16. Standardized radiographic interpretation of thoracic tuberculosis in children.

    PubMed

    Concepcion, Nathan David P; Laya, Bernard F; Andronikou, Savvas; Daltro, Pedro A N; Sanchez, Marion O; Uy, Jacqueline Austine U; Lim, Timothy Reynold U

    2017-09-01

    There is a lack of standardized approach and terminology to classify the diverse spectrum of manifestations in tuberculosis. It is important to recognize the different clinical and radiographic patterns to guide treatment. As a result of changing epidemiology, there is considerable overlap in the radiologic presentations of primary tuberculosis and post-primary tuberculosis. In this article we promote a standardized approach in clinical and radiographic classification for children suspected of having or diagnosed with childhood tuberculosis. We propose standardized terms to diminish confusion and miscommunication, which can affect management. In addition, we present pitfalls and limitations of imaging.

  17. Suppressing beam-centroid motion in a long-pulse linear induction accelerator

    NASA Astrophysics Data System (ADS)

    Ekdahl, Carl; Abeyta, E. O.; Archuleta, R.; Bender, H.; Broste, W.; Carlson, C.; Cook, G.; Frayer, D.; Harrison, J.; Hughes, T.; Johnson, J.; Jacquez, E.; McCuistian, B. Trent; Montoya, N.; Nath, S.; Nielsen, K.; Rose, C.; Schulze, M.; Smith, H. V.; Thoma, C.; Tom, C. Y.

    2011-12-01

    The second axis of the dual-axis radiography of hydrodynamic testing (DARHT) facility produces up to four radiographs within an interval of 1.6μs. It does this by slicing four micropulses out of a 2-μs long electron beam pulse and focusing them onto a bremsstrahlung converter target. The 1.8-kA beam pulse is created by a dispenser cathode diode and accelerated to more than 16 MeV by the unique DARHT Axis-II linear induction accelerator (LIA). Beam motion in the accelerator would be a problem for multipulse flash radiography. High-frequency motion, such as from beam-breakup (BBU) instability, would blur the individual spots. Low-frequency motion, such as produced by pulsed-power variation, would produce spot-to-spot differences. In this article, we describe these sources of beam motion, and the measures we have taken to minimize it. Using the methods discussed, we have reduced beam motion at the accelerator exit to less than 2% of the beam envelope radius for the high-frequency BBU, and less than 1/3 of the envelope radius for the low-frequency sweep.

  18. O-Acetylation of Arabidopsis Hemicellulose Xyloglucan Requires AXY4 or AXY4L, Proteins with a TBL and DUF231 Domain[W][OA

    PubMed Central

    Gille, Sascha; de Souza, Amancio; Xiong, Guangyan; Benz, Monique; Cheng, Kun; Schultink, Alex; Reca, Ida-Barbara; Pauly, Markus

    2011-01-01

    In an Arabidopsis thaliana forward genetic screen aimed at identifying mutants with altered structures of their hemicellulose xyloglucan (axy mutants) using oligosaccharide mass profiling, two nonallelic mutants (axy4-1 and axy4-2) that have a 20 to 35% reduction in xyloglucan O-acetylation were identified. Mapping of the mutation in axy4-1 identified AXY4, a type II transmembrane protein with a Trichome Birefringence-Like domain and a domain of unknown function (DUF231). Loss of AXY4 transcript results in a complete lack of O-acetyl substituents on xyloglucan in several tissues, except seeds. Seed xyloglucan is instead O-acetylated by the paralog AXY4like, as demonstrated by the analysis of the corresponding T-DNA insertional lines. Wall fractionation analysis of axy4 knockout mutants indicated that only a fraction containing xyloglucan is non-O-acetylated. Hence, AXY4/AXY4L is required for the O-acetylation of xyloglucan, and we propose that these proteins represent xyloglucan-specific O-acetyltransferases, although their donor and acceptor substrates have yet to be identified. An Arabidopsis ecotype, Ty-0, has reduced xyloglucan O-acetylation due to mutations in AXY4, demonstrating that O-acetylation of xyloglucan does not impact the plant’s fitness in its natural environment. The relationship of AXY4 with another previously identified group of Arabidopsis proteins involved in general wall O-acetylation, reduced wall acetylation, is discussed. PMID:22086088

  19. A radiographic survey of monumental masonry workers in Aberdeen

    PubMed Central

    Davies, T. A. Lloyd; Doig, A. T.; Fox, A. J.; Greenberg, M.

    1973-01-01

    Lloyd Davies, T. A., Doig, A. T., Fox, A. J., and Greenberg, M. (1973).British Journal of Industrial Medicine,30, 227-231. A radiographic survey of monumental masonry workers in Aberdeen. A survey of radiographic appearances of the lungs of monumental masonry workers in Aberdeen was carried out to determine the present prevalence of abnormalities and to serve as a standard for future comparisons in view of changes in methods of working. No major change could be detected in the status of these granite workers in Aberdeen over the past 20 years but the different methods of survey used by Mair in 1951 and by the present study did not allow of strict comparison. Chest radiographs were reported on by three readers independently using the National Coal Board elaboration of the ILO classification and a score was given to each film using Oldham's method. Multiple regression analysis showed that ϰ-ray changes were related to years in granite but progression was slow in comparison with foundry workers. The prevalence of radiographic appearances of category 1 or greater was 3·0% overall and 4·6% for workers in dusty jobs. Evidence of pneumoconiosis was not observed in workers exposed for less than 20 years. With the environmental control attained the threshold limit values for respirable dust were not often much exceeded. PMID:4353240

  20. Brazilian young dental practitioners' use and acceptance of digital radiographic examinations

    PubMed Central

    de Faria Vasconcelos, Karla; do Nascimento, Eduarda Helena Leandro; Oliveira, Matheus Lima; Freitas, Deborah Queiroz; Haiter-Neto, Francisco

    2016-01-01

    Purpose The aim of this study was to investigate the use and acceptance of digital radiographic examinations by Brazilian dental practitioners in daily practice and to evaluate the advances that have occurred over the past 5 years. Materials and Methods Dental practitioners enrolled in extension courses at the Piracicaba Dental School, University of Campinas, Brazil, responded to a self-administered questionnaire in the years 2011 and 2015. They were asked about sociodemographic factors and their knowledge and use of digital radiographic examinations. Descriptive analysis was performed, as well as the chi-square and Fisher exact tests, with a significance level of 5% (α=0.05). Results A total of 181 participants responded to the questionnaire in the years 2011 and 2015. Most of the respondents worked in private practice, had graduated within the last 5 years, and were between 20 and 30 years old. In 2011, 55.6% of respondents reported having ever used digital radiographic examinations, while in 2015 this number increased significantly to 85.4% (p<.0001), out of which 71.4% preferred it to conventional images. Moreover, 21.4% of respondents reported having used digital radiographic examinations for more than 3 years. A significant increase in use of intraoral digital radiography (p=0.0316) was observed in 2015. In both years, image quality and high cost were indicated, respectively, as the main advantage and disadvantage of digital radiographic examinations. Conclusion This study showed that digital radiology has become more common in Brazil over the past 5 years. Most of the Brazilian dental practitioners evaluated in 2015 used digital radiographic examinations. PMID:28035301

  1. Radiographic protocol and normal anatomy of the hind feet in the white rhinoceros (Ceratotherium simum).

    PubMed

    Dudley, Robert J; Wood, Simon P; Hutchinson, John R; Weller, Renate

    2015-01-01

    Foot pathology is a common and important health concern in captive rhinoceroses worldwide, but osteopathologies are rarely diagnosed, partly because of a lack of radiographic protocols. Here, we aimed to develop the first radiographic protocol for rhinoceros feet and describe the radiographic anatomy of the white rhinoceros (Ceratotherium simum) hind foot (pes). Computed tomographic images were obtained of nine cadaver pedes from seven different white rhinoceroses and assessed for pathology. A single foot deemed free of pathology was radiographed using a range of different projections and exposures to determine the best protocol. 3D models were produced from the CT images and were displayed with the real radiographs to describe the normal radiographic anatomy of the white rhinoceros pes. An optimal radiographic projection was determined for each bone in the rhinoceros pes focusing on highlighting areas where pathology has been previously described. The projections deemed to be most useful were D60Pr-PlDiO (digit III), D45Pr45M-PlDiLO (digit II), and D40Pr35L-PlDiLO (digit IV). The primary beam was centered 5-7 cm proximal to the cuticle on the digit of interest. Articular surfaces, ridges, grooves, tubercles, processes and fossae were identified. The radiographic protocol we have developed along with the normal radiographic anatomy we have described will allow for more accessible and effective diagnosis of white rhinoceros foot osteopathologies. © 2014 American College of Veterinary Radiology.

  2. Radiographic features of cardiogenic pulmonary edema in dogs with mitral regurgitation: 61 cases (1998-2007).

    PubMed

    Diana, Alessia; Guglielmini, Carlo; Pivetta, Mauro; Sanacore, Antonina; Di Tommaso, Morena; Lord, Peter F; Cipone, Mario

    2009-11-01

    To evaluate radiographic distribution of pulmonary edema (PE) in dogs with mitral regurgitation (MR) and investigate the association between location of radiographic findings and direction of the mitral regurgitant jet (MRJ). Retrospective case series. 61 dogs with cardiogenic PE and MR resulting from mitral valve disease (MVD; 51 dogs), dilated cardiomyopathy (9), and hypertrophic cardiomyopathy (1). Thoracic radiographs of dogs with Doppler echocardiographic evidence of MR were reviewed for location (diffuse, perihilar, or focal) of PE. Also, direction (central or eccentric) of the MRJ, as evaluated by Doppler color flow mapping (DCFM), and distribution (symmetric or asymmetric) of radiographic findings were evaluated. Diffuse, perihilar, and focal increases in pulmonary opacity were observed in 11 (18.0%), 7 (11.5%), and 43 (70.5%) of 61 dogs, respectively. Radiographic evidence of asymmetric PE in a single lung lobe or 2 ipsilateral lobes was found in 21 dogs, with involvement of only the right caudal lung lobe in 17 dogs. Doppler color flow mapping of the MRJ was available for 46 dogs. Of 31 dogs with a central MRJ, 28 had radiographic findings indicative of symmetric PE. Of 15 dogs with eccentric MRJ, 11 had radiographic evidence of asymmetric PE, and all of these dogs had MVD. In dogs with cardiogenic PE, a symmetric radiographic distribution of increased pulmonary opacity was predominantly associated with a central MRJ, whereas an asymmetric radiographic distribution was usually associated with eccentric MRJ, especially in dogs with MVD.

  3. The multi-axis vibration environment and man.

    PubMed

    Lovesey, E J

    1970-12-01

    Many investigations into the effects of vibration on man have been performed since Mallock's first study of London Underground vibrations in 1902. The vibration research has tended to be confined to the vertical (heave) axis, yet recent experiments have indicated that low frequency vibration along the lateral (sway) axis has a greater adverse effect upon comfort and performance. Measurements of the vibration environments in current forms of transport including motor vehicles, hovercraft and aircraft etc have shown that appreciable quantities of vibration along all three axes exist. Further vibration research should consider the effects of multi-axis vibrations upon man rather than limit tests to single axis vibration.

  4. Potassium-Based Dual Ion Battery with Dual-Graphite Electrode.

    PubMed

    Fan, Ling; Liu, Qian; Chen, Suhua; Lin, Kairui; Xu, Zhi; Lu, Bingan

    2017-08-01

    A potassium ion battery has potential applications for large scale electric energy storage systems due to the abundance and low cost of potassium resources. Dual graphite batteries, with graphite as both anode and cathode, eliminate the use of transition metal compounds and greatly lower the overall cost. Herein, combining the merits of the potassium ion battery and dual graphite battery, a potassium-based dual ion battery with dual-graphite electrode is developed. It delivers a reversible capacity of 62 mA h g -1 and medium discharge voltage of ≈3.96 V. The intercalation/deintercalation mechanism of K + and PF 6 - into/from graphite is proposed and discussed in detail, with various characterizations to support. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Development of a detector model for generation of synthetic radiographs of cargo containers

    NASA Astrophysics Data System (ADS)

    White, Timothy A.; Bredt, Ofelia P.; Schweppe, John E.; Runkle, Robert C.

    2008-05-01

    Creation of synthetic cargo-container radiographs that possess attributes of their empirical counterparts requires accurate models of the imaging-system response. Synthetic radiographs serve as surrogate data in studies aimed at determining system effectiveness for detecting target objects when it is impractical to collect a large set of empirical radiographs. In the case where a detailed understanding of the detector system is available, an accurate detector model can be derived from first-principles. In the absence of this detail, it is necessary to derive empirical models of the imaging-system response from radiographs of well-characterized objects. Such a case is the topic of this work, where we demonstrate the development of an empirical model of a gamma-ray radiography system with the intent of creating a detector-response model that translates uncollided photon transport calculations into realistic synthetic radiographs. The detector-response model is calibrated to field measurements of well-characterized objects thus incorporating properties such as system sensitivity, spatial resolution, contrast and noise.

  6. Veterinary nurse to medical diagnostic radiographer.

    PubMed

    Taylor, Nicholas

    2017-08-19

    Nicholas Taylor is senior diagnostic radiographer at the Great Western Hospital, Swindon, having initially qualified as a veterinary nurse. It was a college lecture that initially sparked his interest in radiography - little did he know where it would lead. British Veterinary Association.

  7. Radiographic progression of silicosis among Japanese tunnel workers in Kochi.

    PubMed

    Dumavibhat, Narongpon; Matsui, Tomomi; Hoshino, Eri; Rattanasiri, Sasivimol; Muntham, Dittapol; Hirota, Ryoji; Eitoku, Masamitsu; Imanaka, Momo; Muzembo, Basilua Andre; Ngatu, Nlandu Roger; Kondo, Shinichi; Hamada, Norihiko; Suganuma, Narufumi

    2013-01-01

    The aim of our study was to investigate the natural course of silicosis in terms of radiographic progression among Japanese tunnel workers. Tunnel workers with silicosis were included in our study between January 2008 and June 2011. We retrospectively assessed workers' radiographs from their first through last visits to see whether there was progression. All films were interpreted by two physicians, who had been specially trained in using the ILO (2000) International Classification of Radiographs of Pneumoconioses (ILO/ICRP). We classified the radiographic findings according to the ILO/ICRP. Survival analysis was performed and then presented as time to progression. Subgroup analysis among the progressed group was performed to demonstrate duration of progression. A total of 65 patients, who were no longer exposed to silica for the duration of the study, were included. The mean age at the first visit was 58.60 ± 7.10 years. The incidence rate of progression was 42 per 1,000 person-years with a median time to progression of 17 years. Progression was demonstrated among 33 cases (51%). The mean durations of progression from category 1 to category 4 and category 2 to category 4 were 14.55 and 10.65 years, respectively. Most patients (86%) had radiographic change from category 1 or 2 directly to category 4. Silicosis progressed at a relatively high rate among tunnel workers without further silica exposure. The high probability of progression directly from category 1 to category 4 may lead to further investigation for the improvement of disease prevention.

  8. Radiographic Prevalence of Dysplasia, Cam, and Pincer Deformities in Elite Ballet.

    PubMed

    Harris, Joshua D; Gerrie, Brayden J; Varner, Kevin E; Lintner, David M; McCulloch, Patrick C

    2016-01-01

    The demands of hip strength and motion in ballet are high. Hip disorders, such as cam and pincer deformities or dysplasia, may affect dance performance. However, the prevalence of these radiographic findings is unknown. To determine the prevalence of radiographic cam and pincer deformities, borderline dysplasia, and dysplasia in a professional ballet company. Cross-sectional study; Level of evidence, 3. An institutional review board-approved cross-sectional investigation of a professional ballet company was undertaken. Male and female adult dancers were eligible for inclusion. Four plain radiographs were obtained (standing anteroposterior pelvis, bilateral false profile, and supine Dunn 45°) and verified for adequacy. Cam and pincer deformities, dysplasia, borderline dysplasia, and osteoarthritis were defined. All plain radiographic parameters were measured and analyzed on available radiographs. Student t test, chi-square test (and Fisher exact test), and Spearman correlation analyses were performed to compare sexes, groups, and the effect of select radiographic criteria. A total of 47 dancers were analyzed (21 males, 26 females; mean age (±SD), 23.8 ± 5.4 years). Cam deformity was identified in 25.5% (24/94) of hips and 31.9% (15/47) of subjects, with a significantly greater prevalence in male dancers than females (48% hips and 57% subjects vs 8% hips and 12% subjects; P < .001 and P = .001, respectively). Seventy-four percent of subjects had at least 2 of 6 radiographic signs of pincer deformity. Male dancers had a significantly greater prevalence of both prominent ischial spine and posterior wall signs (P = .001 and P < .001, respectively), while female dancers had a significantly greater prevalence of coxa profunda (85% female hips vs 26% male hips; P < .001). Eighty-nine percent of subjects had dysplasia or borderline dysplasia in at least 1 hip (37% dysplastic), with a significantly greater prevalence of dysplasia or borderline dysplasia in female versus

  9. 42 CFR 37.45 - Protection against radiation emitted by radiographic equipment.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Protection against radiation emitted by radiographic equipment. 37.45 Section 37.45 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN... against radiation emitted by radiographic equipment. Except as otherwise specified in § 37.41 and § 37.42...

  10. Detailed Concepts in Performing Oversight on an Army Radiographic Inspection Site

    DTIC Science & Technology

    2017-03-01

    number of facilities that perform various nondestructive tests , inspections, and evaluations. The U.S. Army Armament Research, Development and...procedures, and documentation in place to conform to nationally recognized standards. This report specifically reviews the radiographic testing ...X-ray Nondestructive testing (NDT) Radiographic testing (RT) Computed tomography (CT) 16. SECURITY

  11. The impact of dual-source parallel radiofrequency transmission with patient-adaptive shimming on the cardiac magnetic resonance in children at 3.0 T.

    PubMed

    Wang, Haipeng; Qiu, Liyun; Wang, Guangbin; Gao, Fei; Jia, Haipeng; Zhao, Junyu; Chen, Weibo; Wang, Cuiyan; Zhao, Bin

    2017-06-01

    The cardiac magnetic resonance (CMR) of children at 3.0 T presents a unique set of technical challenges because of their small cardiac anatomical structures, fast heart rates, and the limited ability to keep motionless and hold breathe, which could cause problems associated with field inhomogeneity and degrade the image quality. The aim of our study was to evaluate the effect of dual-source parallel radiofrequency (RF) transmission on the B1 homogeneity and image quality in children with CMR at 3.0 T. The study was approved by the institutional ethics committee and written informed consent was obtained. A total of 30 free-breathing children and 30 breath-hold children performed CMR examinations with dual-source and single-source RF transmission. The B1 homogeneity, contrast ratio (CR) of cine images, and off-resonance artifacts in cine images between dual-source and single-source RF transmission were assessed in free-breathing and breath-hold groups, respectively. In both free-breathing and breath-hold groups, higher mean percentage of flip angle (free-breathing group: 104.2 ± 4.6 vs 95.5 ± 6.3, P < .001; breath-hold group: 101.5 ± 5.1 vs 92.5 ± 6.3, P < .001) and lower coefficient of variation (free-breathing group: 0.06 ± 0.02 vs 0.09 ± 0.03, P < .001; breath-hold group: 0.07 ± 0.03 vs 0.10 ± 0.04, P = .005) were found with dual-source than with single-source RF transmission. Both the CRs in the horizontal long axis (HLA) and short axis of cine images with dual-source RF transmission was improved (P < .05 for all). The scores of off-resonance artifacts in the HLA with dual-source RF transmission were higher in both free-breathing and breath-hold groups (P < .05 for all), with substantial interreader agreement (kappa values from 0.68 to 0.74). Compared with conventional single-source, dual-source parallel RF transmission could significantly improve the B1 homogeneity and image quality for CMR in

  12. Radiographic Outcomes of Volar Locked Plating for Distal Radius Fractures

    PubMed Central

    Mignemi, Megan E.; Byram, Ian R.; Wolfe, Carmen C.; Fan, Kang-Hsien; Koehler, Elizabeth A.; Block, John J.; Jordanov, Martin I.; Watson, Jeffry T.; Weikert, Douglas R.; Lee, Donald H.

    2013-01-01

    Purpose To assess the ability of volar locked plating to achieve and maintain normal radiographic parameters for articular stepoff, volar tilt, radial inclination, ulnar variance, and radial height in distal radius fractures. Methods We performed a retrospective review of 185 distal radius fractures that underwent volar locked plating with a single plate design over a 5-year period. We reviewed radiographs and recorded measurements for volar tilt, radial inclination, ulnar variance, radial height, and articular stepoff. We used logistic regression to determine the association between return to radiographic standard norms and fracture type. Results At the first and final postoperative follow-up visits, we observed articular congruence less than 2 mm in 92% of fractures at both times. Normal volar tilt (11°) was restored in 46% at the first follow-up and 48% at the final one. Radial inclination (22°) was achieved in 44% at the first follow-up and 43% at the final one, and ulnar variance (01 ± 2 mm) was achieved in 53% at the first follow-up and 53% at the final one. In addition, radial height (14 ± 1mm) was restored in 14% at the first follow-up and 12% at the final one. More complex, intra-articular fractures (AO class B and C and Frykman types 3, 4, 7, and 8) were less likely to be restored to normal radiographic parameters. However, because of the small sample size for some fracture types, it was difficult to discover significant associations between fracture type and radiographic outcome. Conclusions Volar locked plating for distal radius fractures achieved articular stepoff less than 2 mm in most fractures but only restored and maintained normal radiographic measurements for volar tilt, radial inclination, and ulnar variance in 50% of fractures. The ability of volar locked plating to restore and maintain ulnar variance and volar tilt decreased with more complex intra-articular fracture types. PMID:23218558

  13. The thyroid axis in ageing.

    PubMed

    Leitol, Holger; Behrends, Jens; Brabant, Georg

    2002-01-01

    The hypothalmo-pituitary thyroid axis, among various endocrine systems, undergoes physiological alterations associated with the ageing process. Directly age-related changes have to be distinguished from indirect modifications which are caused by simultaneous thyroidal or non-thyroidal illness or other physiological or pathophysiological states whose incidence increases with age. In summary, direct changes of the hypothalmo-pituitary-thyroid axis seem to be subtle and suggestive of a decreased hypothalamic stimulation of thyroid function. In parallel, disease-specific alterations such as the development of thyroid autonomy or changes in energy intake or sleep lead to pronounced alterations of thyroid function with age which may dominate the underlying ageing of the hypothalmo-pituitary thyroid axis itself. The following article attempts to delineate some aspects of the interplay of the regulation of thyroid function and the ageing process.

  14. Evaluation of trabecular bone patterns on dental radiographic images: influence of cortical bone

    NASA Astrophysics Data System (ADS)

    Amouriq, Yves; Evenou, Pierre; Arlicot, Aurore; Normand, Nicolas; Layrolle, Pierre; Weiss, Pierre; Guédon, Jean-Pierre

    2010-03-01

    For some authors trabecular bone is highly visible in intraoral radiographs. For other authors, the observed intrabony trabecular pattern is a representation of only the endosteal surface of cortical bone, not of intermedullary striae. The purpose of this preliminary study was to investigate the true anatomical structures that are visible in routine dental radiographs and classically denoted trabecular bone. This is a major point for bone texture analysis on radiographs. Computed radiography (CR) images of dog mandible section in molar region were compared with simulations calculated from high-resolution micro-CT volumes. Calculated simulations were obtained using the Mojette Transform. By digitally editing the CT volume, the simulations were separated into trabecular and cortical components into a region of interest. Different images were compared and correlated, some bone micro-architecture parameters calculated. A high correlation was found between computed radiographs and calculated simulations from micro-CT. The Mojette transform was successful to obtain high quality images. Cortical bone did not contribute to change in a major way simulated images. These first results imply that intrabony trabecular pattern observed on radiographs can not only be a representation of the cortical bone endosteal surface and that trabecular bone is highly visible in intraoral radiographs.

  15. Apical root resorption of incisors after orthodontic treatment of impacted maxillary canines: a radiographic study.

    PubMed

    Brusveen, Elin Marie Gravdal; Brudvik, Pongsri; Bøe, Olav Egil; Mavragani, Maria

    2012-04-01

    The purpose of the study was to evaluate impacted maxillary canines as risk factor for orthodontic apical root resorption. The sample comprised 66 patients treated with fixed appliances. Thirty-two patients with a unilateral impacted maxillary canine, which was distanced from the roots of the incisors at a preliminary phase of treatment before bonding, formed the impaction group, and 34 patients without impactions served as the controls. Root shortening was calculated by using pretreatment and posttreatment intraoral radiographs. Inclination of the eruption path of the impacted canine relative to the midline, axis of the lateral incisor, and nasal line, root development, and the medial and vertical positions of the impacted tooth were recorded on orthopantomograms and lateral cephalometric films. The follicle/tooth ratio was evaluated by using periapical radiographs. No significant difference in apical resorption of the maxillary incisors was detected between the impaction and control groups, or between the incisors of the impacted and contralateral sides in the same subject. Likewise, no difference in the severity of root resorption was found between the incisors of impacted side alone and the incisors of the control group. Mesial and vertical inclinations of the impacted canines were negatively related to a lateral incisor's root resorption. No correlations were found between resorption and medial or vertical position of the crown of the canine. The follicle/tooth ratio was significantly related to the mesial inclination of the impacted canine, but not to root resorption. An impacted maxillary canine, after being distanced from the incisor roots, does not seem to be a risk factor for apical root resorption during orthodontic treatment. Copyright © 2012 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

  16. Application of an electronic image analyzer to dimensional measurements from neutron radiographs

    NASA Technical Reports Server (NTRS)

    Vary, A.; Bowles, K. J.

    1973-01-01

    Means of obtaining improved dimensional measurements from neutron radiographs of nuclear fuel elements are discussed. The use of video-electronic image analysis relative to edge definition in radiographic images is described. Based on this study, an edge definition criterion is proposed for overcoming image unsharpness effects in taking accurate diametral measurements from radiographs. An electronic density slicing method for automatic edge definition is described. Results of measurements made with video micrometry are compared with scanning microdensitometer and micrometric physical measurements. An image quality indicator for estimating photographic and geometric unsharpness is described.

  17. Acute myocardial infarction with changing axis deviation.

    PubMed

    Patanè, Salvatore; Marte, Filippo

    2011-07-01

    Changing axis deviation has been rarely reported also during atrial fibrillation or atrial flutter. Changing axis deviation has been rarely reported also during acute myocardial infarction associated with atrial fibrillation. Isolated left posterior hemiblock is a very rare finding but the evidence of transient right axis deviation with a left posterior hemiblock pattern has been reported during acute anterior myocardial infarction as related with significant right coronary artery obstruction and collateral circulation between the left coronary system and the posterior descending artery. Left anterior hemiblock development during acute inferior myocardial infarction can be an indicator of left anterior descending coronary artery lesions, multivessel coronary artery disease, and impaired left ventricular systolic function. We present a case of changing axis deviation in a 62-year-old Italian man with acute myocardial infarction. Also this case focuses attention on changing axis deviation during acute myocardial infarction. Copyright © 2009 Elsevier Ireland Ltd. All rights reserved.

  18. Pilot study evaluating the effects of a cervical headgear on the C-axis: the growth axis of the dentomaxillary complex.

    PubMed

    Braun, Stanley; Bottrel, J Alexandre

    2004-12-01

    The C-axis, a growth vector for the dentomaxillary complex, is a means of quantifying complex maxillary growth in the sagittal plane through 3 key cephalometric measurements. This pilot study examined the effect of a cervical headgear, worn 8 to 10 hours per day, on the growth axis. The mean velocity of C-axis length increase in normally growing boys in the age range studied is 1.14 mm per year. In normally growing girls, the C-axis length increase is nonlinear, varying from a mean of 1.67 mm per year at age 9 and to 0.78 mm per year at 13.5 years of age. The cervical headgear reduced the C-axis length increases by 73.7% in boys and 61.1% in girls. The growth axis vector angle theta; was not clinically affected in either sex, but the palatal plane angle alpha became more acute in both sexes, rather than becoming more obtuse as it does in normally growing adolescents. Additional research should be undertaken to determine the effects on the C-axis by other cervical headgears having different lines of action relative to the center of resistance of the dentomaxillary complex, as well as occipital-pull and straight distal-pull headgear.

  19. Radiographic evaluation of bone adaptation adjacent to percutaneous osseointegrated prostheses in a sheep model.

    PubMed

    Jeyapalina, Sujee; Beck, James Peter; Bachus, Kent N; Chalayon, Ornusa; Bloebaum, Roy D

    2014-10-01

    Percutaneous osseointegrated prostheses (POPs) are being investigated as an alternative to conventional socket suspension and require a radiographic followup in translational studies to confirm that design objectives are being met. In this 12-month animal study, we determined (1) radiographic signs of osseointegration and (2) radiographic signs of periprosthetic bone hypertrophy and resorption (adaptation) and (3) confirmed them with the histologic evidence of host bone osseointegration and adaptation around a novel, distally porous-coated titanium POP with a collar. A POP device was designed to fit the right metacarpal bone of sheep. Amputation and implantation surgeries (n = 14) were performed, and plane-film radiographs were collected quarterly for 12 months. Radiographs were assessed for osseointegration (fixation) and bone adaptation (resorption and hypertrophy). The cortical wall and medullary canal widths were used to compute the cortical index and expressed as a percentage. Based on the cortical index changes and histologic evaluations, bone adaptation was quantified. Radiographic data showed signs of osseointegration including those with incomplete seating against the collar attachment. Cortical index data indicated distal cortical wall thinning if the collar was not seated distally. When implants were bound proximally, bone resorbed distally and the diaphyseal cortex hypertrophied. Histopathologic evidence and cortical index measurements confirmed the radiographic indications of adaptation and osseointegration. Distal bone loading, through collar attachment and porous coating, limited the distal bone resorption. Serial radiographic studies, in either animal models or preclinical trials for new POP devices, will help to determine which designs are likely to be safe over time and avoid implant failures.

  20. Assessment of radiation protection awareness and knowledge about radiological examination doses among Italian radiographers.

    PubMed

    Paolicchi, F; Miniati, F; Bastiani, L; Faggioni, L; Ciaramella, A; Creonti, I; Sottocornola, C; Dionisi, C; Caramella, D

    2016-04-01

    To evaluate radiation protection basic knowledge and dose assessment for radiological procedures among Italian radiographers A validated questionnaire was distributed to 780 participants with balanced demographic characteristics and geographic distribution. Only 12.1 % of participants attended radiation protection courses on a regular basis. Despite 90 % of radiographers stating to have sufficient awareness of radiation protection issues, most of them underestimated the radiation dose of almost all radiological procedures. About 5 % and 4 % of the participants, respectively, claimed that pelvis magnetic resonance imaging and abdominal ultrasound exposed patients to radiation. On the contrary, 7.0 % of the radiographers stated that mammography does not use ionising radiation. About half of participants believed that radiation-induced cancer is not dependent on age or gender and were not able to differentiate between deterministic and stochastic effects. Young radiographers (with less than 3 years of experience) showed a higher level of knowledge compared with the more experienced radiographers. There is a substantial need for radiographers to improve their awareness of radiation protection issues and their knowledge of radiological procedures. Specific actions such as regular training courses for both undergraduate and postgraduate students as well as for working radiographers must be considered in order to assure patient safety during radiological examinations. • Radiographers should improve their knowledge on radiation protection issues. • Only 12.1 % of participants attended radiation protection courses on a regular basis. • Specific actions must be considered in order to increase knowledge and awareness.