Sample records for ratio resulting images

  1. Image Enhancement by Spectral Ratioing,


    images et Vacquisition d’objectif dans 1’ infrarouge ", DREV R-4050/76, avril 1976, NON CIASSIFIE. UNCLASSIFIED 16 7. Sdvigny, L., "Simulation d’un d’acquisition automatique d’objectif infrarouge dans un contexte sol-sol", DREV R-4081/77, juin 1977, NON CIASSIFIE. 8. S6vigny, L., "La...reconnaissance de forme et I’acquisition d’objectif en infrarouge : Nouvel algorithme de detection", DREV R-4099/78, mars 1979, NON CEASSIFIE. 9. Panda, D.P

  2. Simpler images, better results

    Chance, Britton


    The very rapid development of optical technology has followed a pattern similar to that of nuclear magnetic resonance: first, spectroscopy and then imaging. The accomplishments in spectroscopy have been significant--among them, early detection of hematomas and quantitative oximetry (assuming that time and frequency domain instruments are used). Imaging has progressed somewhat later. The first images were obtained in Japan and USA a few years ago, particularly of parietal stimulation of the human brain. Since then, rapid applications to breast and limb, together with higher resolution of the brain now make NIR imaging of functional activation and tumor detection readily available, reliable and affordable devices. The lecture has to do with the applications of imaging to these three areas, particularly to prefrontal imaging of cognitive function, of breast tumor detection, and of localized muscle activation in exercise. The imaging resolution achievable in functional activation appears to be FWHM of 4 mm. The time required for an image is a few seconds or even much less. Breast image detection at 50 microsecond(s) ec/pixel results in images obtainable in a few seconds or shorter times (bandwidths of the kHz are available). Finally, imaging of the body organs is under study in this laboratory, particularly in the in utero fetus. It appears that the photon migration theory now leads to the development of a wide number of images for human subject tissue spectroscopy and imaging.

  3. Agreement in Measurement of Optic Cup-to-Disc Ratio with Stereo Biomicroscope Funduscopy and Digital Image Analysis: Results from the Nigeria National Blindness and Visual Impairment Survey.

    Kyari, Fatima; Gilbert, Clare


    To determine agreement in estimations of vertical cup-to-disc ratio (VCDR) between clinical stereo-biomicroscopic funduscopy and digital fundus image analysis. Systematic sampling of 1-in-7 from a sample of 13,591 participants aged ≥40 years gave a subsample who were examined in detail. VCDR was estimated clinically by 60 diopter aspheric lens biomicroscopic funduscopy (c-VCDR) and by digital fundus images (i-VCDR) graded at the Moorfields Eye Hospital Reading Centre. Spearman's correlation coefficient, paired t-test and the Bland-Altman method to assess limits of agreement (LOA) between the two methods were applied. Of 1759 participants in the subsample, 848 participants (48%) with normal frequency doubling technology (FDT) visual fields and data for i-VCDR and c-VCDR in both eyes (n = 1696 eyes) were included in the analysis. By absolute difference of VCDR values for each eye between the two methods, 1585 eyes (94%) differed by ≤0.2. Mean i-VCDR was 0.381 (standard deviation, SD 0.156), and mean c-VCDR 0.321 (SD 0.145). i-VCDRs were significantly larger by a mean difference of 0.061 (SD 0.121; 95% confidence interval, CI, 0.055-0.066; p Digital image analysis and clinical assessment are two distinct methods to measure VCDR; with larger i-VCDRs in this survey. Applying i-VCDR cut-off values to c-VCDR measurements in the Nigeria Blindness Survey might have underestimated glaucoma prevalence. It is recommended that all participants in glaucoma surveys have VCDR by digital image measurement.

  4. Annotating images by mining image search results

    Wang, X.J.; Zhang, L.; Li, X.; Ma, W.Y.


    Although it has been studied for years by the computer vision and machine learning communities, image annotation is still far from practical. In this paper, we propose a novel attempt at model-free image annotation, which is a data-driven approach that annotates images by mining their search results

  5. Annotating images by mining image search results.

    Wang, Xin-Jing; Zhang, Lei; Li, Xirong; Ma, Wei-Ying


    Although it has been studied for years by the computer vision and machine learning communities, image annotation is still far from practical. In this paper, we propose a novel attempt at model-free image annotation, which is a data-driven approach that annotates images by mining their search results. Some 2.4 million images with their surrounding text are collected from a few photo forums to support this approach. The entire process is formulated in a divide-and-conquer framework where a query keyword is provided along with the uncaptioned image to improve both the effectiveness and efficiency. This is helpful when the collected data set is not dense everywhere. In this sense, our approach contains three steps: 1) the search process to discover visually and semantically similar search results, 2) the mining process to identify salient terms from textual descriptions of the search results, and 3) the annotation rejection process to filter out noisy terms yielded by Step 2. To ensure real-time annotation, two key techniques are leveraged-one is to map the high-dimensional image visual features into hash codes, the other is to implement it as a distributed system, of which the search and mining processes are provided as Web services. As a typical result, the entire process finishes in less than 1 second. Since no training data set is required, our approach enables annotating with unlimited vocabulary and is highly scalable and robust to outliers. Experimental results on both real Web images and a benchmark image data set show the effectiveness and efficiency of the proposed algorithm. It is also worth noting that, although the entire approach is illustrated within the divide-and conquer framework, a query keyword is not crucial to our current implementation. We provide experimental results to prove this.

  6. Lattice QCD results on cumulant ratios at freeze-out

    Karsch, Frithjof


    Ratios of cumulants of net proton-number fluctuations measured by the STAR Collaboration show strong deviations from a skellam distribution, which should describe thermal properties of cumulant ratios, if proton-number fluctuations are generated in equilibrium and a hadron resonance gas (HRG) model would provide a suitable description of thermodynamics at the freeze-out temperature. We present some results on sixth order cumulants entering the calculation of the QCD equation of state at non-zero values of the baryon chemical potential (mu_B) and discuss limitations on the applicability of HRG thermodynamics deduced from a comparison between QCD and HRG model calculations of cumulants of conserved charge fluctuations. We show that basic features of the $\\mu_B$-dependence of skewness and kurtosis ratios of net proton-number fluctuations measured by the STAR Collaboration resemble those expected from a O(mu_B^2) QCD calculation of the corresponding net baryon-number cumulant ratios.

  7. A gray-natural logarithm ratio bilateral filtering method for image processing

    Guanan Chen; Kuntao Yang; Rong Chen; Zhiming Xie


    A new method based on gray-natural logarithm ratio bilateral filtering is presented for image smoothing in this work. A new gray-natural logarithm ratio range filter kernel, leading to adaptive magnitude from image gray distinction information, is pointed out for the bilateral filtering. The new method can not only well restrain noise but also keep much more weak edges and details of an image, and preserve the original color transition of color images. Experimental results show the effectiveness for image denoising with our method.

  8. Optimization of pediatric chest radiographic images using optical densities ratio

    Souza, Rafael T.F.; Miranda, Jose R.A. [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Botucatu, SP (Brazil). Inst. de Biociencias de Botucatu; Pina, Diana R. [Faculdade de Medicina de Botucatu (UNESP), Botucatu, SP (Brazil). Hospital das Clinicas. Dept. de Doencas Tropicais e Diagnostico por Imagem; Duarte, Sergio B. [Centro Brasileiro de Pesquisas Fisicas (CBPF/MCT), Rio de Janeiro, RJ (Brazil)


    The aim of this study is the optimization of radiographic images for the pediatric patients in the age range between 0 and 1 years old, through Optical Density Ratio (ODR), considering that pediatric patients are overexposed to radiation in the repeated attempts to obtain radiographic images considered of good quality. The optimization of radiographic techniques was carried out with the RAP-PEPP (Realistic Analytical Phantom coupled to homogeneous Phantom Equivalent to Pediatric Patient) phantom in two incubators and one cradle. The data show that the clinical routine radiographic techniques generate low-quality images at up to 18.8% when evaluated by the ODRs, and increases in doses up to 60% when compared to the optimized techniques doses. (author)

  9. Recent results in imaging lidar

    Ulich, Bobby L.; Lacovara, Philip; Moran, Steven E.; DeWeert, Michael J.


    Imaging lidar, in which light detection and ranging is implemented with sufficient spatial resolution to resolve the size and shape of an object, has demonstrated impressive performance for detecting and classifying underwater targets. During 1996 the U.S. Navy deployed its first imaging lidar system with Naval Air Reserve Squadron HSL-94. This paper reviews the Magic LanternR system and discusses new technology and trends for future systems.

  10. Scaling images using their background ratio. An application in statistical comparisons of images.

    Kalemis, A; Binnie, D; Bailey, D L; Flower, M A; Ott, R J


    Comparison of two medical images often requires image scaling as a pre-processing step. This is usually done with the scaling-to-the-mean or scaling-to-the-maximum techniques which, under certain circumstances, in quantitative applications may contribute a significant amount of bias. In this paper, we present a simple scaling method which assumes only that the most predominant values in the corresponding images belong to their background structure. The ratio of the two images to be compared is calculated and its frequency histogram is plotted. The scaling factor is given by the position of the peak in this histogram which belongs to the background structure. The method was tested against the traditional scaling-to-the-mean technique on simulated planar gamma-camera images which were compared using pixelwise statistical parametric tests. Both sensitivity and specificity for each condition were measured over a range of different contrasts and sizes of inhomogeneity for the two scaling techniques. The new method was found to preserve sensitivity in all cases while the traditional technique resulted in significant degradation of sensitivity in certain cases.

  11. Recent Opportunity Microscopic Imager Results

    Herkenhoff, K. E.; Arvidson, R. E.; Jolliff, B. L.; Yingst, R.; Team, A.


    Opportunity. The extremely soft bedrock exposed at a Whitewater Lake outcrop target dubbed 'Azilda' is mostly fine-grained, with dispersed 2-5 mm-diameter spherules and resistant veins. This target was easily abraded by the RAT, exposing a sandstone-like texture, but the sorting of grains is difficult to determine at MI resolution. Darker, erosion-resistant veneers, similar to desert varnishes on Earth, appear to record aqueous alteration that post-dates the formation of the Ca sulfate veins; they likely contain the nontronite that is observed by CRISM in this area. The inferred neutral pH and relatively low temperature of the fluids involved in these phases of alteration would have provided a habitable environment for life if it existed on Mars at that time. Because Opportunity can no longer directly sense phyllosilicate mineralogy with the MiniTES or Mössbauer spectrometers, it is focusing on characterizing the chemistry with the APXS and texture with the MI of potential phyllosilicate host rocks. The Athena MI continues to return useful images of Mars that are being used to study the textures of rocks and soils at Endeavour crater. Exploration by Opportunity continues, with the rover approaching 'Solander Point' and more exposures of phyllosilicates detected from orbit; the latest MI results will be presented at the conference.

  12. [Examination of R-L shunt ratio mensuration using dynamic images in lung perfusion scintigraphy].

    Ichikawa, Hajime; Yamada, Sayaka; Yoshioka, Chiho; Tamaoki, Toyoshi; Miura, Syunichi; Suzuki, Motoki; Makino, Tetsuzou


    We examined a method of quantitative analysis that used dynamic and static images to measure the Right-left (R-L) shunt ratio in lung perfusion scintigraphy. A total of 18 patients suspected of having R-L shunt brought on by congenital heart disease were referred for lung perfusion scintigraphy from November 2005 to February 2007 at our hospital. We acquired anterior dynamic images, set ROIs in all fields of view, and measured the highest count. We acquired anterior and posterior static images of the chest and measured lung counts. We considered the highest count on dynamic images to be the total injection dose per one second, normalized the acquisition time of static images, and calculated the R-L shunt ratio. We weighed the measurement results of the R-L shunt ratio obtained by the dynamic method against that of the whole-body method by t-test and the least-squares method. When we used a posterior static image in the dynamic method, we found that the coefficient of correlation (r) was 0.9831. The result of the t-test was that there was no significant difference at a level of significance of 1%. We think the use of the dynamic method is possible in R-L shunt ratio measurement and can shorten the examination time.

  13. Poisson’s Ratio Extrapolation from Digital Image Correlation Experiments


    base propellant was composed of nitroglycerin and nitrocellulose . The composite propellant was a hydroxyl-terminated polybutadiene (HTPB) propellant ...uses speckle patterns to determine surface strains, has been used recently to investigate values for Poisson’s ratio in solid propellant specimens...Work was performed on both a double-base and a composite propellant , and results indicate that the method is useful for determination of Poisson’s

  14. LOFAR: Recent imaging results & future prospects

    Heald, George; Horneffer, Andreas; Offringa, André R; Pizzo, Roberto; van der Tol, Sebastiaan; van Weeren, Reinout J; van Zwieten, Joris E; Anderson, James M; Beck, Rainer; van Bemmel, Ilse; Bîrzan, Laura; Bonafede, Annalisa; Conway, John; Ferrari, Chiara; De Gasperin, Francesco; Haverkorn, Marijke; Jackson, Neal; Macario, Giulia; McKean, John; Miraghaei, Halime; Orrù, Emanuela; Rafferty, David; Röttgering, Huub; Scaife, Anna; Shulevski, Aleksandar; Sotomayor, Carlos; Tasse, Cyril; Trasatti, Monica; Wucknitz, Olaf


    The Low Frequency Array (LOFAR) is under construction in the Netherlands and in several surrounding European countries. In this contribution, we describe the layout and design of the telescope, with a particular emphasis on the imaging characteristics of the array when used in its "standard imaging" mode. After briefly reviewing the calibration and imaging software used for LOFAR image processing, we show some recent results from the ongoing imaging commissioning efforts. We conclude by summarizing future prospects for the use of LOFAR in observing the little-explored low frequency Universe.

  15. Segmentation of the Striatum from MR Brain Images to Calculate the -TRODAT-1 Binding Ratio in SPECT Images

    Ching-Fen Jiang


    Full Text Available Quantification of regional -TRODAT-1 binding ratio in the striatum regions in SPECT images is essential for differential diagnosis between Alzheimer's and Parkinson's diseases. Defining the region of the striatum in the SPECT image is the first step toward success in the quantification of the TRODAT-1 binding ratio. However, because SPECT images reveal insufficient information regarding the anatomical structure of the brain, correct delineation of the striatum directly from the SPECT image is almost impossible. We present a method integrating the active contour model and the hybrid registration technique to extract regions from MR T1-weighted images and map them into the corresponding SPECT images. Results from three normal subjects suggest that the segmentation accuracy using the proposed method was compatible with the expert decision but has a higher efficiency and reproducibility than manual delineation. The binding ratio derived by this method correlated well (R2 = 0.76 with those values calculated by commercial software, suggesting the feasibility of the proposed method.

  16. Initial Results of Ultraviolet Imager on AKATSUKI

    Yamazaki, Atsushi; Yamada, Manabu; Watanabe, Shigeto; Imamura, Takeshi


    The UV images of the Venusian cloud top were obtained by several Venus spacecrafts such as Mariner 10 [Bruce et al., 1974], Pioneer Venus [Travis et al., 1979; Rossow et al., 1980], Galileo [Belton et al., 1991], Venus Express [Markiewicz et al., 2007; Titov et al., 2008]. Those previous instruments have taken images at the wavelength around 365-nm, but what material distribution reflects the contrasting density has been unknown yet. There is the SO2 absorption band around the 283-nm wavelength, and the 283-nm images clarify the distribution of SO2. The ultraviolet imager (UVI) on the AKATUSKI satellite takes ultraviolet images of the solar radiation scattered at the Venusian cloud top level at the both 283- and 365-nm wavelengths. There are absorption bands of SO2 and unknown absorber in these wavelength regions. The UVI carries out the measurements of the SO2 and the unknown absorber distributions, and the sequential images lead to understand the velocity vector of the wind at the cloud top altitude. The UVI is equipped with fast off-axial catadioptric optics, two bandpass filters and a diffuser installed in a filter wheel moving with a stepping motor, and a high-sensitive CCD devise with a UV coating. The UVI takes images of the ultraviolet solar radiation scattered from the Venusian cloud top in two wavelength ranges at the center of 283nm and 365nm with bandpass of 15 nm. A back illuminated type of a frame-transfer CCD with a UV sensitive coating is adopted. Its effective area is 1024 x 1024 pixels. UVI has 12-deg field-of-view, so the angular resolution is 0.012 deg/pix. The nominal exposure time is 125 msec and 46 msec at the observations of the 283- and 365-nm wavelengths, respectively. CCD has no mechanical shutter, so a smear noise in transferring from the image area to the storage area degrades the signal-to-noise ratio of the signal image especially in the short exposure operation. The images have a signal-to-noise ratio of over 100 after desmearing of

  17. Construction of a Ca II Core-to-Wing Ratio Image

    Roberts, H.


    To understand Earth's climate, we must first understand the Sun. However, there are still significant uncertainties associated with both the fundamental mechanisms of solar variability and how they enter into the Earth's climate system. An important method to study the causes of solar variability can be found through the analysis of solar images. The Precision Solar Photometric Telescope (PSPT) located at the Mauna Loa Solar Observatory (MLSO) acquires images of the Sun in three different photometric bands to monitor the evolution of solar surface features that change over the course of a solar cycle. These images provide a complete knowledge about the Sun by targeting different layers of the solar atmosphere. Though raw images are meaningful and important, precision image processing is required to remove instrumental artifacts and false features that may appear in these images prior to usage for scientific purposes. A scientific application of the high precision solar images is investigated by analyzing a set of narrow band of Calcium II K core and wing images. The Core and Wing images are processed to remove the influence of the center-to-limb variation; the resultant core-to-wing ratio image enhances the appearance of network structures on the entire solar disk along with the more obvious facula and plage brightening associated with the passage of active regions.

  18. LOFAR: Recent Imaging Results and Future Prospects

    George Heald; Michael R. Bell; Andreas Horneffer; André R. Offringa; Roberto Pizzo; Sebastiaan van der Tol; Reinout J. van Weeren; Joris E. van Zwieten; James M. Anderson; Rainer Beck; Ilse van Bemmel; Laura Bîrzan; Annalisa Bonafede; John Conway; Chiara Ferrari; Francesco De Gasperin; Marijke Haverkorn; Neal Jackson; Giulia Macario; John McKean; Halime Miraghaei; Emanuela Orrù; David Rafferty; Huub Röttgering; Anna Scaife; Aleksandar Shulevski; Carlos Sotomayor; Cyril Tasse; Monica Trasatti; Olaf Wucknitz


    The Low-Frequency Array (LOFAR) is under construction in the Netherlands and in several surrounding European countries. In this contribution, we describe the layout and design of the telescope, with particular emphasis on the imaging characteristics of the array when used in its `standard imaging’ mode. After briefly reviewing the calibration and imaging software used for LOFAR image processing, we show some recent results from the ongoing imaging commissioning efforts. We conclude by summarizing future prospects for the use of LOFAR in observing the little-explored low-frequency Universe.

  19. Extreme Contrast Ratio Imaging of Sirius with a Charge Injection Device

    Batcheldor, D; Bahr, C; Jenne, J; Ninkov, Z; Bhaskaran, S; Chapman, T


    The next fundamental steps forward in understanding our place in the universe could be a result of advances in extreme contrast ratio (ECR) imaging and point spread function (PSF) suppression. For example, blinded by quasar light we have yet to fully understand the processes of galaxy formation and evolution, and there is an ongoing race to obtain a direct image of an exoearth lost in the glare of its host star. To fully explore the features of these systems we must perform observations in which contrast ratios of at least one billion can be regularly achieved with sub 0.1" inner working angles. Here we present the details of a latest generation 32-bit charge injection device (CID) that could conceivably achieve contrast ratios on the order of one billion. We also demonstrate some of its ECR imaging abilities for astronomical imaging. At a separation of two arc minutes, we report a direct contrast ratio of Delta(m_v)=18.3, log(CR)=7.3, or 1 part in 20 million, from observations of the Sirius field. The atmosp...

  20. Method to evaluate the L/D ratio of neutron imaging beams

    Pugliesi, R.; Pereira, M.A. Stanojev; Schoueri, R.M., E-mail: [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)


    An alternative simple method to evaluate the L/D ratio of neutron imaging beams is proposed. It is based on the behavior of the ratio 'x/Ut', which asymptotically tends to L/D for large values of the parameter 'x', that corresponds to the distance separating a gadolinium test object to the scintillator plane, where its image is formed. The method was applied to the neutron imaging equipment of the Nuclear and Energy Research Institute IPEN/CNEN-SP and the obtained result was L/D = (104 ± 4). The consistency of the proposed method was verified by comparing this value with those ones obtained by a well - known and established procedure. (author)

  1. Dual energy contrast enhanced breast imaging optimization using contrast to noise ratio

    Arvanitis, C. D.; Royle, G.; Speller, R.


    The properties of dual energy contrast enhanced breast imaging have been analyzed by imaging a 4 cm breast equivalent phantom consisting of adipose and glandular equivalent plastics. This phantom had superimposed another thin plastic which incorporated a 2 mm deep cylinder filled with iodinated contrast media. The iodine projected thicknesses used for this study was 3 mg/cm2. Low and high energy spectra that straddle the iodine K-edge were used. Critical parameters such as the energy spectra and exposure are discussed, along with post processing by means of nonlinear energy dependent function. The dual energy image was evaluated using the relative contrast to noise ratio of a 2.5 mm x 2.5 mm region of the image at the different iodine concentrations incorporating different breast composition with respect to the noniodinated areas. Optimum results were achieved when the low and high-energy images were used in such a way that relative contrast to noise ratio of the iodine with respect to the background tissue was maximum. A figure of merit suggests that higher noise levels can be tolerated at the benefit of lower exposure. Contrast media kinetics of a phantom incorporating a water flow of 20.4 ml/min through the plastic cylinder suggests that time domain imaging could be performed with this approach. The results suggest that optimization of dual energy contrast enhanced mammography has the potential to lead to the development of perfusion digital mammography.

  2. Overview of Athena Microscopic Imager Results

    Herkenhoff, K.; Squyres, S.; Arvidson, R.; Bass, D.; Bell, J., III; Bertelsen, P.; Cabrol, N.; Ehlmann, B.; Farrand, W.; Gaddis, L.


    The Athena science payload on the Mars Exploration Rovers (MER) includes the Microscopic Imager (MI). The MI is a fixed-focus camera mounted on an extendable arm, the Instrument Deployment Device (IDD). The MI acquires images at a spatial resolution of 31 microns/pixel over a broad spectral range (400 - 700 nm). The MI uses the same electronics design as the other MER cameras but its optics yield a field of view of 32 32 mm across a 1024 1024 pixel CCD image. The MI acquires images using only solar or skylight illumination of the target surface. The MI science objectives, instrument design and calibration, operation, and data processing were described by Herkenhoff et al. Initial results of the MI experiment on both MER rovers (Spirit and Opportunity) have been published previously. Highlights of these and more recent results are described.

  3. Benchmarking result diversification in social image retrieval

    Ionescu, Bogdan; Popescu, Adrian; Müller, Henning


    This article addresses the issue of retrieval result diversification in the context of social image retrieval and discusses the results achieved during the MediaEval 2013 benchmarking. 38 runs and their results are described and analyzed in this text. A comparison of the use of expert vs....... crowdsourcing annotations shows that crowdsourcing results are slightly different and have higher inter observer differences but results are comparable at lower cost. Multimodal approaches have best results in terms of cluster recall. Manual approaches can lead to high precision but often lower diversity....... With this detailed results analysis we give future insights on this matter....

  4. High Etendue Imaging Fourier Transform Spectrometer: initial results

    Horton, Richard F.; Conger, Chris A.; Pelligrino, L. S.


    At the Denver meeting, last year, we presented the High Etendue Imaging Fourier Transform Spectrometer, (HEIFTS), theory and optical design. This device uses a new 'image plane interferometer' geometry to produce 'autocorrelation function modulation' in the image plane of a 2D imaging array, such that the phase offset of the modulation varies linearly across the image. As a 2D image is pushbroomed across the imaging, array, the record of an individual scene pixel is recorded for each autocorrelation phase offset. The 3D array of this data is processed to yield an 'autocorrelation function' data cube, which is Fourier transformed to yield a 'wavenumber' hyperspectral data curve. A phase I device has been demonstrated in the laboratory and initial results are presented. The significant increase in signal to noise ratio, which the HEIFTS optical design promises over conventional hyperspectral imaging schemes, has been simulated, and results will be discussed. A Phase II system is being prepared for initial field deployment, and will be described.

  5. Retrospective reconstruction of cardiac cine images from golden-ratio radial MRI using one-dimensional navigators.

    Krämer, Martin; Herrmann, Karl-Heinz; Biermann, Judith; Reichenbach, Jurgen R


    To demonstrate radial golden-ratio-based cardiac cine imaging by using interspersed one-dimensional (1D) navigators. The 1D navigators were interspersed into the acquisition of radial spokes which were continuously rotated by an angle increment based on the golden-ratio. Performing correlation analysis between the 1D navigator projections, time points corresponding to the same cardiac motion phases were automatically identified and used to combine retrospectively golden-ratio rotated radial spokes from multiple data windows. Data windows were shifted consecutively for dynamic reconstruction of different cardiac motion frames. Experiments were performed during a single breathhold. By artificially reducing the amount of input data, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) as well as artifact level was evaluated for different breathhold durations. Analysis of the 1D navigator data provided a detailed correlation function revealing cardiac motion over time. Imaging results were comparable to images reconstructed based on a timely synchronized ECG. Cardiac cine images with a low artifact level and good image quality in terms of SNR and CNR were reconstructed from volunteer data achieving a CNR between the myocardium and the left ventricular cavity of 50 for the longest breathhold duration of 26 s. CNR maintained a value higher than 30 for acquisition times as low as 10 s. Combining radial golden-ratio-based imaging with an intrinsic navigator is a promising and robust method for performing high quality cardiac cine imaging. © 2013 Wiley Periodicals, Inc.

  6. Multi-images deconvolution improves signal-to-noise ratio on gated stimulated emission depletion microscopy

    Castello, Marco [Nanobiophotonics, Nanophysics, Istituto Italiano di Tecnologia, Via Morego 30, Genoa, 16163 (Italy); DIBRIS, University of Genoa, Via Opera Pia 13, Genoa 16145 (Italy); Diaspro, Alberto [Nanobiophotonics, Nanophysics, Istituto Italiano di Tecnologia, Via Morego 30, Genoa, 16163 (Italy); Nikon Imaging Center, Via Morego 30, Genoa 16163 (Italy); Vicidomini, Giuseppe, E-mail: [Nanobiophotonics, Nanophysics, Istituto Italiano di Tecnologia, Via Morego 30, Genoa, 16163 (Italy)


    Time-gated detection, namely, only collecting the fluorescence photons after a time-delay from the excitation events, reduces complexity, cost, and illumination intensity of a stimulated emission depletion (STED) microscope. In the gated continuous-wave- (CW-) STED implementation, the spatial resolution improves with increased time-delay, but the signal-to-noise ratio (SNR) reduces. Thus, in sub-optimal conditions, such as a low photon-budget regime, the SNR reduction can cancel-out the expected gain in resolution. Here, we propose a method which does not discard photons, but instead collects all the photons in different time-gates and recombines them through a multi-image deconvolution. Our results, obtained on simulated and experimental data, show that the SNR of the restored image improves relative to the gated image, thereby improving the effective resolution.

  7. Extreme Contrast Ratio Imaging of Sirius with a Charge Injection Device

    Batcheldor, D.; Foadi, R.; Bahr, C.; Jenne, J.; Ninkov, Z.; Bhaskaran, S.; Chapman, T.


    The next fundamental steps forward in understanding our place in the universe could be a result of advances in extreme contrast ratio (ECR) imaging and point-spread function (PSF) suppression. For example, blinded by quasar light we have yet to fully understand the processes of galaxy and star formation and evolution, and there is an ongoing race to obtain a direct image of an exo-Earth lost in the glare of its host star. To fully explore the features of these systems, we must perform observations in which contrast ratios (CRs) of at least one billion can be regularly achieved with sub 0.″1 inner working angles. Here, we present the details of a latest-generation 32-bit charge injection device (CID) that could conceivably achieve CRs on the order of one billion. We also demonstrate some of its ECR imaging abilities for astronomical imaging. At a separation of two arcminutes, we report a direct CR of {{Δ }}{m}v=18.3,{log}({CR})=7.3, or 1 part in 20 million, from observations of the Sirius field. The atmospheric conditions present during the collection of this data prevented less modest results, and we expect to be able to achieve higher CRs, with improved inner working angles, simply by operating a CID at a world-class observing site. However, CIDs do not directly provide any PSF suppression. Therefore, combining CID imaging with a simple PSF suppression technique like angular differential imaging could provide a cheap and easy alternative to the complex ECR techniques currently being employed.

  8. Guidelines and recommended terms for expression of stable-isotope-ratio and gas-ratio measurement results

    Coplen, Tyler B.


    To minimize confusion in the expression of measurement results of stable isotope and gas-ratio measurements, recommendations based on publications of the Commission on Isotopic Abundances and Atomic Weights of the International Union of Pure and Applied Chemistry (IUPAC) are presented. Whenever feasible, entries are consistent with the Système International d'Unités, the SI (known in English as the International System of Units), and the third edition of the International Vocabulary of Basic and General Terms in Metrology (VIM, 3rd edition). The recommendations presented herein are approved by the Commission on Isotopic Abundances and Atomic Weights and are designed to clarify expression of quantities related to measurement of isotope and gas ratios to ensure that quantity equations instead of numerical value equations are used for quantity definitions. Examples of column headings consistent with quantity calculus (also called the algebra of quantities) and examples of various deprecated usages connected with the terms recommended are presented.

  9. Particle image velocimetry correlation signal-to-noise ratio metrics and measurement uncertainty quantification

    Xue, Zhenyu; Vlachos, Pavlos P


    In particle image velocimetry (PIV) the measurement signal is contained in the recorded intensity of the particle image pattern superimposed on a variety of noise sources. The signal-to-noise-ratio (SNR) strength governs the resulting PIV cross correlation and ultimately the accuracy and uncertainty of the resulting PIV measurement. Hence we posit that correlation SNR metrics calculated from the correlation plane can be used to quantify the quality of the correlation and the resulting uncertainty of an individual measurement. In this paper we present a framework for evaluating the correlation SNR using a set of different metrics, which in turn are used to develop models for uncertainty estimation. The SNR metrics and corresponding models presented herein are expanded to be applicable to both standard and filtered correlations. In addition, the notion of a valid measurement is redefined with respect to the correlation peak width in order to be consistent with uncertainty quantification principles and distinct ...


    N. M. S. M. Kadhim


    Full Text Available Very-High-Resolution (VHR satellite imagery is a powerful source of data for detecting and extracting information about urban constructions. Shadow in the VHR satellite imageries provides vital information on urban construction forms, illumination direction, and the spatial distribution of the objects that can help to further understanding of the built environment. However, to extract shadows, the automated detection of shadows from images must be accurate. This paper reviews current automatic approaches that have been used for shadow detection from VHR satellite images and comprises two main parts. In the first part, shadow concepts are presented in terms of shadow appearance in the VHR satellite imageries, current shadow detection methods, and the usefulness of shadow detection in urban environments. In the second part, we adopted two approaches which are considered current state-of-the-art shadow detection, and segmentation algorithms using WorldView-3 and Quickbird images. In the first approach, the ratios between the NIR and visible bands were computed on a pixel-by-pixel basis, which allows for disambiguation between shadows and dark objects. To obtain an accurate shadow candidate map, we further refine the shadow map after applying the ratio algorithm on the Quickbird image. The second selected approach is the GrabCut segmentation approach for examining its performance in detecting the shadow regions of urban objects using the true colour image from WorldView-3. Further refinement was applied to attain a segmented shadow map. Although the detection of shadow regions is a very difficult task when they are derived from a VHR satellite image that comprises a visible spectrum range (RGB true colour, the results demonstrate that the detection of shadow regions in the WorldView-3 image is a reasonable separation from other objects by applying the GrabCut algorithm. In addition, the derived shadow map from the Quickbird image indicates

  11. Personalizing Image Search Results on Flickr

    Lerman, Kristina; Wong, Chio


    The social media site Flickr allows users to upload their photos, annotate them with tags, submit them to groups, and also to form social networks by adding other users as contacts. Flickr offers multiple ways of browsing or searching it. One option is tag search, which returns all images tagged with a specific keyword. If the keyword is ambiguous, e.g., ``beetle'' could mean an insect or a car, tag search results will include many images that are not relevant to the sense the user had in mind when executing the query. We claim that users express their photography interests through the metadata they add in the form of contacts and image annotations. We show how to exploit this metadata to personalize search results for the user, thereby improving search performance. First, we show that we can significantly improve search precision by filtering tag search results by user's contacts or a larger social network that includes those contact's contacts. Secondly, we describe a probabilistic model that takes advantag...

  12. Guidelines and recommended terms for expression of stable-isotope-ratio and gas-ratio measurement results.

    Coplen, Tyler B


    To minimize confusion in the expression of measurement results of stable isotope and gas-ratio measurements, recommendations based on publications of the Commission on Isotopic Abundances and Atomic Weights of the International Union of Pure and Applied Chemistry (IUPAC) are presented. Whenever feasible, entries are consistent with the Système International d'Unités, the SI (known in English as the International System of Units), and the third edition of the International Vocabulary of Basic and General Terms in Metrology (VIM, 3rd edition). The recommendations presented herein are approved by the Commission on Isotopic Abundances and Atomic Weights and are designed to clarify expression of quantities related to measurement of isotope and gas ratios to ensure that quantity equations instead of numerical value equations are used for quantity definitions. Examples of column headings consistent with quantity calculus (also called the algebra of quantities) and examples of various deprecated usages connected with the terms recommended are presented. Published in 2011 by John Wiley & Sons, Ltd.

  13. Estimation of uncertainty bounds for individual particle image velocimetry measurements from cross-correlation peak ratio

    Charonko, John J.; Vlachos, Pavlos P.


    Numerous studies have established firmly that particle image velocimetry (PIV) is a robust method for non-invasive, quantitative measurements of fluid velocity, and that when carefully conducted, typical measurements can accurately detect displacements in digital images with a resolution well below a single pixel (in some cases well below a hundredth of a pixel). However, to date, these estimates have only been able to provide guidance on the expected error for an average measurement under specific image quality and flow conditions. This paper demonstrates a new method for estimating the uncertainty bounds to within a given confidence interval for a specific, individual measurement. Here, cross-correlation peak ratio, the ratio of primary to secondary peak height, is shown to correlate strongly with the range of observed error values for a given measurement, regardless of flow condition or image quality. This relationship is significantly stronger for phase-only generalized cross-correlation PIV processing, while the standard correlation approach showed weaker performance. Using an analytical model of the relationship derived from synthetic data sets, the uncertainty bounds at a 95% confidence interval are then computed for several artificial and experimental flow fields, and the resulting errors are shown to match closely to the predicted uncertainties. While this method stops short of being able to predict the true error for a given measurement, knowledge of the uncertainty level for a PIV experiment should provide great benefits when applying the results of PIV analysis to engineering design studies and computational fluid dynamics validation efforts. Moreover, this approach is exceptionally simple to implement and requires negligible additional computational cost.


    B. Ruf


    Full Text Available With the emergence of small consumer Unmanned Aerial Vehicles (UAVs, the importance and interest of image-based depth estimation and model generation from aerial images has greatly increased in the photogrammetric society. In our work, we focus on algorithms that allow an online image-based dense depth estimation from video sequences, which enables the direct and live structural analysis of the depicted scene. Therefore, we use a multi-view plane-sweep algorithm with a semi-global matching (SGM optimization which is parallelized for general purpose computation on a GPU (GPGPU, reaching sufficient performance to keep up with the key-frames of input sequences. One important aspect to reach good performance is the way to sample the scene space, creating plane hypotheses. A small step size between consecutive planes, which is needed to reconstruct details in the near vicinity of the camera may lead to ambiguities in distant regions, due to the perspective projection of the camera. Furthermore, an equidistant sampling with a small step size produces a large number of plane hypotheses, leading to high computational effort. To overcome these problems, we present a novel methodology to directly determine the sampling points of plane-sweep algorithms in image space. The use of the perspective invariant cross-ratio allows us to derive the location of the sampling planes directly from the image data. With this, we efficiently sample the scene space, achieving higher sampling density in areas which are close to the camera and a lower density in distant regions. We evaluate our approach on a synthetic benchmark dataset for quantitative evaluation and on a real-image dataset consisting of aerial imagery. The experiments reveal that an inverse sampling achieves equal and better results than a linear sampling, with less sampling points and thus less runtime. Our algorithm allows an online computation of depth maps for subsequences of five frames, provided that

  15. Estimation of sufficient signal to noise ratio for texture analysis of magnetic resonance images

    Savio, Sami; Harrison, Lara; Ryymin, Pertti; Dastidar, Prasun; Soimakallio, Seppo; Eskola, Hannu


    In this study, we have studied the effect of background noise on the texture analysis of muscle, bone marrow and fat tissues in 1.5 T magnetic resonance (MR) images using different statistical methods. Variable levels of noise were first added on 3-mm thick T2 weighted image slices of voluntary subjects to simulate several signal-to-noise ratio (SNR) levels. For each original and simulated image, the values for 264 texture parameters were calculated using MaZda, a texture analysis toolkit. We also determined Fisher coefficients based on the texture parameter values in order to enable high discrimination between different tissues. Linear discriminant analysis (LDA) and two different nearest neighbour (NN) methods were then applied for the texture parameters with the highest Fisher coefficient values. Several training and test sets were used to approximate the variation in the classification results. All the above-mentioned methods had the same classification accuracy, which in turn depended on the image SNR. We conclude that these tissues can be detected by texture analysis methods with a sufficient accuracy (90%) especially if SNR is at least 30-40 dB, even though the separation of different muscles remains a very challenging task.

  16. Imaging resolution signal-to-noise ratio in transverse phase amplification from classical information theory

    French, Doug [School of Nuclear Engineering, Purdue University, West Lafayette, IN 47907 (United States)], E-mail:; Huang Zun; Pao, H.-Y.; Jovanovic, Igor [School of Nuclear Engineering, Purdue University, West Lafayette, IN 47907 (United States)


    A quantum phase amplifier operated in the spatial domain can improve the signal-to-noise ratio in imaging beyond the classical limit. The scaling of the signal-to-noise ratio with the gain of the quantum phase amplifier is derived from classical information theory.

  17. Modeling the behavior of signal-to-noise ratio for repeated snapshot imaging

    Li, Junhui; Yang, Dongyue; Wu, Guohua; Yin, Longfei; Guo, Hong


    For imaging of static object by the means of sequential repeated independent measurements, a theoretical modeling of the behavior of signal-to-noise ratio (SNR) with varying number of measurement is developed, based on the information capacity of optical imaging systems. Experimental veritification of imaging using pseudo-thermal light source is implemented, for both the direct average of multiple measurements, and the image reconstructed by second order fluctuation correlation (SFC) which is closely related to ghost imaging. Successful curve fitting of data measured under different conditions verifies the model.


    Dumont, Douglas M.; Walsh, Kristy M.; Byram, Brett C.


    Radiation force-based elasticity imaging is currently being investigated as a possible diagnostic modality for a number of clinical tasks, including liver fibrosis staging and the characterization of cardiovascular tissue. In this study, we evaluate the relationship between peak displacement magnitude and image quality and propose using a Bayesian estimator to overcome the challenge of obtaining viable data in low displacement signal environments. Displacement data quality were quantified for two common radiation force-based applications, acoustic radiation force impulse imaging, which measures the displacement within the region of excitation, and shear wave elasticity imaging, which measures displacements outside the region of excitation. Performance as a function of peak displacement magnitude for acoustic radiation force impulse imaging was assessed in simulations and lesion phantoms by quantifying signal-to-noise ratio (SNR) and contrast-to-noise ratio for varying peak displacement magnitudes. Overall performance for shear wave elasticity imaging was assessed in ex vivo chicken breast samples by measuring the displacement SNR as a function of distance from the excitation source. The results show that for any given displacement magnitude level, the Bayesian estimator can increase the SNR by approximately 9 dB over normalized cross-correlation and the contrast-to-noise ratio by a factor of two. We conclude from the results that a Bayesian estimator may be useful for increasing data quality in SNR-limited imaging environments. PMID:27157861

  19. Digital subtraction peripheral angiography using image stacking: initial clinical results.

    Kump, K S; Sachs, P B; Wilson, D L


    Using clinically acquired x-ray angiography image sequences, we compared three algorithms for creating a single diagnostic quality image that combined input images containing flowing contrast agent. These image-stacking algorithms were: maximum opacity with the minimum gray-scale value across time recorded at each spatial location, (REC) recursive temporal filtering followed by a maximum opacity operation, and (AMF) an approximate matched filter consisting of a convolution with a kernel approximating the matched filter followed by a maximum opacity operation. Eighteen clinical exams of the peripheral arteries of the legs were evaluated. AMF gave 2.7 times greater contrast to noise ratio than the single best subtraction image and 1.3 times improvement over REC, the second best stacking algorithm. This is consistent with previous simulations showing that AMF performs nearly equal to the optimal result from matched filtering without the well-known limitations. For example, unlike matched filtering, AMF filter coefficients were obtained automatically using an image-processing algorithm. AMF effectively brought out small collateral arteries, otherwise difficult to see, without degrading artery sharpness or stenosis grading. Comparing results using reduced and full contrast agent volumes demonstrated that contrast agent load could be reduced to one-third of the conventional amount with AMF processing. By simulating reduced x-ray exposures on clinical exams, we determined that x-ray exposure could be reduced by 80% with AMF processing. We conclude that AMF is a promising, potential technique for reducing contrast agent load and for improving vessel visibility, both very important characteristics for vascular imaging.

  20. LOFAR : Recent Imaging Results and Future Prospects

    Heald, George; Bell, Michael R.; Horneffer, Andreas; Offringa, Andre R.; Pizzo, Roberto; van der Tol, Sebastiaan; van Weeren, Reinout J.; van Zwieten, Joris E.; Anderson, James M.; Beck, Rainer; van Bemmel, Ilse; Birzan, Laura; Bonafede, Annalisa; Conway, John; Ferrari, Chiara; De Gasperin, Francesco; Haverkorn, Marijke; Jackson, Neal; Macario, Giulia; McKean, John; Miraghaei, Halime; Orru, Emanuela; Rafferty, David; Rottgering, Huub; Scaife, Anna; Shulevski, Aleksandar; Sotomayor, Carlos; Tasse, Cyril; Trasatti, Monica; Wucknitz, Olaf


    The Low-Frequency Array (LOFAR) is under construction in the Netherlands and in several surrounding European countries. In this contribution, we describe the layout and design of the telescope, with particular emphasis on the imaging characteristics of the array when used in its 'standard imaging' m

  1. Relationship Model Between Nightlight Data and Floor Area Ratio from High Resolution Images

    Yan, M.; Xu, L.


    It is a hotpot that extraction the floor area ratio from high resolution remote sensing images. It is a development trend of using nightlight data to survey the urban social and economic information. This document aims to provide a conference relationship model for VIIRS/NPP nightlight data and floor Area Ratio from High Resolution ZY-3 Images. It shows that there is a lineal relationship between the shadow and the floor area ratio, and the R2 is 0.98. It shows that there is a quadratic polynomial relationship between the floor area ratio and the nightlight, and the R2 is 0.611. We can get a conclusion that, VIIRS/NPP nightlights data may show the floor area ratio in an extent at level of administrative street.

  2. Estimating grass-clover ratio variations caused by traffic intensities using image analysis

    Jørgensen, Rasmus Nyholm; Sørensen, Claus Grøn; Green, Ole

    ensuring that the whole parcel was imaged. Each image was geo-positioned. The image analysis comprised two steps: Extraction of green material and discrimination of grass and clover using the morphological opening approach. This paper shows the initial results using the automated imaging analysis algorithm...

  3. Imaging with the leak microstructures: preliminary results

    Baiocchi, C.; Balbinot, G; Battistella, A.; Galeazzi, G.; Lombardi, F.S.; Lombardi, M. E-mail:; Prete, G.; Simon, A


    We report on some images obtained with the Leak Microstructures (LM), which are elements for the detection of gas ionizing particles based on needle-point anodes. X-ray images of a mask with seven holes, 300 {mu}m in diameter and 100 {mu}m separated, drilled on a tantalum sheet were obtained with a very good spatial resolution. Varying the potential to the drifting electrode we put in evidence the possibility to perform a 'zoom' of the image. X-ray images of a tantalum sheet of about 20x20 mm{sup 2} were obtained using a matrix of 9x9 LMs read by only 6 electronic chains (6 ADCs)

  4. Strain ratio measurement of femoral cartilage by real-time elastosonography: preliminary results

    Ipek, Ali; Unal, Ozlem; Kartal, Merve Gulbiz; Arslan, Halil [Yildirim Beyazit University, Department of Radiology, Faculty of Medicine, Ataturk Training and Research Hospital, Ankara (Turkey); Isik, Cetin; Bozkurt, Murat [Yildirim Beyazit University, Department of Orthopedics, Faculty of Medicine, Ataturk Training and Research Hospital, Ankara (Turkey)


    The purpose of this study was to evaluate strain ratio measurement of femoral cartilage using real-time elastosonography. Twenty-five patients with femoral cartilage pathology on MRI (study group) were prospectively compared with 25 subjects with normal findings on MRI (control group) using real-time elastosonography. Strain ratio measurements of pathologic and normal cartilage were performed and compared, both within the study group and between the two groups. Elastosonography colour-scale coding showed a colour change from blue to red in pathologic cartilage and only blue colour-coding in normal cartilage. In the study group, the median strain ratio was higher in pathologic cartilage areas compared to normal areas (median, 1.49 [interquartile range, 0.80-2.53] vs. median, 0.01 [interquartile range, 0.01-0.01], p < 0.001, respectively). The median strain ratio of the control group was 0.01 (interquartile range, 0.01-0.01), and there was no significant difference compared to normal areas of the study group. There was, however, a significant difference between the control group cartilage and pathologic cartilage of the study group (p < 0.001). Elastosonography may be an effective, easily accessible, and relatively simple tool to demonstrate pathologic cartilage and to differentiate it from normal cartilage in the absence of advanced imaging facility such as MRI. (orig.)

  5. Evaluation of the ventilation-perfusion ratio in lung diseases by simultaneous anterior and posterior image acquisition

    Nakata, Yasunobu; Narabayashi, Isamu; Sueyoshi, Kozo; Matsui, Ritsuo; Namba, Ryuichiro; Tabuchi, Kojiro (Osaka Medical Coll., Takatsuki (Japan))


    Ventilation and perfusion images were acquired during tidal breathing using [sup 81m]Kr gas and [sup 99m]Tc-MAA. Anterior and posterior functional images of V/Q and Q/V were simultaneously acquired in 34 subjects with various lung diseases and 6 healthy controls. Superimposed anterior and posterior images were constructed and histograms of the frequency distribution for ventilation, perfusion, and the V/Q ratio were displayed for both lungs as well as for the left and right lungs individually. Blood gas analysis and general lung function tests were also performed on the day before scintigraphy. A correlation between marked uneven distribution of V/Q and A-aDO[sub 2] was found. When the proportion of counts at V/Q<0.67 and/or V/Q>1.50 in the V/Q counts histogram was compared with A-aDO[sub 2], there was a significant positive correlation for anterior images (r=0.684, p<0.05), posterior images (r=0.654, p<0.05) and superimposed images (r=0.696, p<0.05). Superimposed images therefore showed the highest correlation. There was no correlation between the results of lung function testing and A-aDO[sub 2]. Coronal SPECT images were also obtained in 15 patients and compared with the superimposed anterior and posterior planar images. There was a good correlation (r=0.888, p<0.001) between both the imaging methods regarding the marked uneven distribution of V/Q. Simultaneous anterior and posterior planar image acquisition reduces the examining time, is simple, and is noninvasive. The present results also suggest that it is useful for quantitative evaluation of the ventilation-perfusion ratio. (author).

  6. Statistical modeling and MAP estimation for body fat quantification with MRI ratio imaging

    Wong, Wilbur C. K.; Johnson, David H.; Wilson, David L.


    We are developing small animal imaging techniques to characterize the kinetics of lipid accumulation/reduction of fat depots in response to genetic/dietary factors associated with obesity and metabolic syndromes. Recently, we developed an MR ratio imaging technique that approximately yields lipid/{lipid + water}. In this work, we develop a statistical model for the ratio distribution that explicitly includes a partial volume (PV) fraction of fat and a mixture of a Rician and multiple Gaussians. Monte Carlo hypothesis testing showed that our model was valid over a wide range of coefficient of variation of the denominator distribution (c.v.: 0-0:20) and correlation coefficient among the numerator and denominator (ρ 0-0.95), which cover the typical values that we found in MRI data sets (c.v.: 0:027-0:063, ρ: 0:50-0:75). Then a maximum a posteriori (MAP) estimate for the fat percentage per voxel is proposed. Using a digital phantom with many PV voxels, we found that ratio values were not linearly related to PV fat content and that our method accurately described the histogram. In addition, the new method estimated the ground truth within +1.6% vs. +43% for an approach using an uncorrected ratio image, when we simply threshold the ratio image. On the six genetically obese rat data sets, the MAP estimate gave total fat volumes of 279 +/- 45mL, values 21% smaller than those from the uncorrected ratio images, principally due to the non-linear PV effect. We conclude that our algorithm can increase the accuracy of fat volume quantification even in regions having many PV voxels, e.g. ectopic fat depots.

  7. A Visual Basic program for analyzing oedometer test results and evaluating intergranular void ratio

    Monkul, M. Murat; Önal, Okan


    A visual basic program (POCI) is proposed and explained in order to analyze oedometer test results. Oedometer test results have vital importance from geotechnical point of view, since settlement requirements usually control the design of foundations. The software POCI is developed in order perform the necessary calculations for convential oedometer test. The change of global void ratio and stress-strain characteristics can be observed both numerically and graphically. It enables the users to calculate some parameters such as coefficient of consolidation, compression index, recompression index, and preconsolidation pressure depending on the type and stress history of the soil. Moreover, it adopts the concept of intergranular void ratio which may be important especially in the compression behavior of sandy soils. POCI shows the variation of intergranular void ratio and also enables the users to calculate granular compression index.

  8. Change detection from synthetic aperture radar images based on neighborhood-based ratio and extreme learning machine

    Gao, Feng; Dong, Junyu; Li, Bo; Xu, Qizhi; Xie, Cui


    Change detection is of high practical value to hazard assessment, crop growth monitoring, and urban sprawl detection. A synthetic aperture radar (SAR) image is the ideal information source for performing change detection since it is independent of atmospheric and sunlight conditions. Existing SAR image change detection methods usually generate a difference image (DI) first and use clustering methods to classify the pixels of DI into changed class and unchanged class. Some useful information may get lost in the DI generation process. This paper proposed an SAR image change detection method based on neighborhood-based ratio (NR) and extreme learning machine (ELM). NR operator is utilized for obtaining some interested pixels that have high probability of being changed or unchanged. Then, image patches centered at these pixels are generated, and ELM is employed to train a model by using these patches. Finally, pixels in both original SAR images are classified by the pretrained ELM model. The preclassification result and the ELM classification result are combined to form the final change map. The experimental results obtained on three real SAR image datasets and one simulated dataset show that the proposed method is robust to speckle noise and is effective to detect change information among multitemporal SAR images.

  9. Microgradients in bacterial colonies : use of fluorescence ratio imaging : a non-invasive technique

    Malakar, P.K.; Brocklehurst, T.F.; Mackie, A.R.; Wilson, P.D.G.; Zwietering, M.H.; Riet, K. van 't


    Fluorescence ratio imaging is a non-invasive technique for studying the formation of microgradients in immobilised bacterial colonies. These gradients can be quantified easily when combined with the gel cassette system designed at the Institute of Food Research, Norwich, UK. Colonies of

  10. Image fusion in dual energy computed tomography for detection of various anatomic structures - Effect on contrast enhancement, contrast-to-noise ratio, signal-to-noise ratio and image quality

    Paul, Jijo, E-mail: [Department of Diagnostic Radiology, Goethe University Hospital, Theodor-Stern-Kai 7, 60590 Frankfurt am Main (Germany); Department of Biophysics, Goethe University, Max von Laue-Str.1, 60438 Frankfurt am Main (Germany); Bauer, Ralf W. [Department of Diagnostic Radiology, Goethe University Hospital, Theodor-Stern-Kai 7, 60590 Frankfurt am Main (Germany); Maentele, Werner [Department of Biophysics, Goethe University, Max von Laue-Str.1, 60438 Frankfurt am Main (Germany); Vogl, Thomas J. [Department of Diagnostic Radiology, Goethe University Hospital, Theodor-Stern-Kai 7, 60590 Frankfurt am Main (Germany)


    Objective: The purpose of this study was to evaluate image fusion in dual energy computed tomography for detecting various anatomic structures based on the effect on contrast enhancement, contrast-to-noise ratio, signal-to-noise ratio and image quality. Material and methods: Forty patients underwent a CT neck with dual energy mode (DECT under a Somatom Definition flash Dual Source CT scanner (Siemens, Forchheim, Germany)). Tube voltage: 80-kV and Sn140-kV; tube current: 110 and 290 mA s; collimation-2 x 32 x 0.6 mm. Raw data were reconstructed using a soft convolution kernel (D30f). Fused images were calculated using a spectrum of weighting factors (0.0, 0.3, 0.6 0.8 and 1.0) generating different ratios between the 80- and Sn140-kV images (e.g. factor 0.6 corresponds to 60% of their information from the 80-kV image, and 40% from the Sn140-kV image). CT values and SNRs measured in the ascending aorta, thyroid gland, fat, muscle, CSF, spinal cord, bone marrow and brain. In addition, CNR values calculated for aorta, thyroid, muscle and brain. Subjective image quality evaluated using a 5-point grading scale. Results compared using paired t-tests and nonparametric-paired Wilcoxon-Wilcox-test. Results: Statistically significant increases in mean CT values noted in anatomic structures when increasing weighting factors used (all P {<=} 0.001). For example, mean CT values derived from the contrast enhanced aorta were 149.2 {+-} 12.8 Hounsfield Units (HU), 204.8 {+-} 14.4 HU, 267.5 {+-} 18.6 HU, 311.9 {+-} 22.3 HU, 347.3 {+-} 24.7 HU, when the weighting factors 0.0, 0.3, 0.6, 0.8 and 1.0 were used. The highest SNR and CNR values were found in materials when the weighting factor 0.6 used. The difference CNR between the weighting factors 0.6 and 0.3 was statistically significant in the contrast enhanced aorta and thyroid gland (P = 0.012 and P = 0.016, respectively). Visual image assessment for image quality showed the highest score for the data reconstructed using the

  11. Centimeter-deep tissue fluorescence microscopic imaging with high signal-to-noise ratio and picomole sensitivity

    Cheng, Bingbing; Wei, Ming-Yuan; Pei, Yanbo; DSouza, Francis; Nguyen, Kytai T; Hong, Yi; Tang, Liping; Yuan, Baohong


    Fluorescence microscopic imaging in centimeter-deep tissue has been highly sought-after for many years because much interesting in vivo micro-information, such as microcirculation, tumor angiogenesis, and metastasis, may deeply locate in tissue. In this study, for the first time this goal has been achieved in 3-centimeter deep tissue with high signal-to-noise ratio (SNR) and picomole sensitivity under radiation safety thresholds. These results are demonstrated not only in tissue-mimic phantoms but also in actual tissues, such as porcine muscle, ex vivo mouse liver, ex vivo spleen, and in vivo mouse tissue. These results are achieved based on three unique technologies: excellent near infrared ultrasound-switchable fluorescence (USF) contrast agents, a sensitive USF imaging system, and an effective correlation method. Multiplex USF fluorescence imaging is also achieved. It is useful to simultaneously image multiple targets and observe their interactions. This work opens the door for future studies of centimeter...

  12. Non-chondritic iron isotope ratios in planetary mantles as a result of core formation

    Elardo, Stephen M.; Shahar, Anat


    Information about the materials and conditions involved in planetary formation and differentiation in the early Solar System is recorded in iron isotope ratios. Samples from Earth, the Moon, Mars and the asteroid Vesta reveal significant variations in iron isotope ratios, but the sources of these variations remain uncertain. Here we present experiments that demonstrate that under the conditions of planetary core formation expected for the Moon, Mars and Vesta, iron isotopes fractionate between metal and silicate due to the presence of nickel, and enrich the bodies' mantles in isotopically light iron. However, the effect of nickel diminishes at higher temperatures: under conditions expected for Earth's core formation, we infer little fractionation of iron isotopes. From our experimental results and existing conceptual models of magma ocean crystallization and mantle partial melting, we find that nickel-induced fractionation can explain iron isotope variability found in planetary samples without invoking nebular or accretionary processes. We suggest that near-chondritic iron isotope ratios of basalts from Mars and Vesta, as well as the most primitive lunar basalts, were achieved by melting of isotopically light mantles, whereas the heavy iron isotope ratios of terrestrial ocean floor basalts are the result of melting of near-chondritic Earth mantle.

  13. Ultrafast active cavitation imaging with enhanced cavitation to tissue ratio based on wavelet transform and pulse inversion.

    Liu, Runna; Hu, Hong; Xu, Shanshan; Huo, Rui; Wang, Supin; Wan, Mingxi


    The quality of ultrafast active cavitation imaging (UACI) using plane wave transmission is hindered by low transmission pressure, which is necessary to prevent bubble destruction. In this study, a UACI method that combined wavelet transform with pulse inversion (PI) was proposed to enhance the contrast between the cavitation bubbles and surrounding tissues. The main challenge in using wavelet transform is the selection of the optimum mother wavelet. A mother wavelet named "cavitation bubble wavelet" and constructed according to Rayleigh-Plesset-Noltingk-Neppiras-Poritsky model was expected to obtain a high correlation between the bubbles and beamformed echoes. The method was validated by in vitro experiments. Results showed that the image quality was associated with the initial radius of bubble and the scale. The signal-to-noise ratio (SNR) of the best optimum cavitation bubble wavelet transform (CBWT) mode image was improved by 3.2 dB compared with that of the B-mode image in free-field experiments. The cavitation-to-tissue ratio of the best optimum PI-based CBWT mode image was improved by 2.3 dB compared with that of the PI-based B-mode image in tissue experiments. Furthermore, the SNR versus initial radius curve had the potential to estimate the size distribution of cavitation bubbles.

  14. Imaging Atmospheric Cerenkov Telescopes Techniques and Results

    Bradbury, S M


    The hunt for cosmic TeV particle accelerators is prospering through Imaging Atmospheric Cerenkov Telescopes. We face challenges such as low light levels and MHz trigger rates, and the need to distinguish between particle air showers stemming from primary gamma rays and those due to the hadronic cosmic ray background. Our test beam is provided by the Crab Nebula, a steady accelerator of particles to energies beyond 20 TeV. Highly variable gamma-ray emission, coincident with flares at longer wavelengths, is revealing the particle acceleration mechanisms at work in the relativistic jets of Active Galaxies. These 200 GeV to 20 TeV photons propagating over cosmological distances allow us to place a limit on the infra-red background linked to galaxy formation and, some speculate, to the decay of massive relic neutrinos. Gamma rays produced in neutralino annihilation or the evaporation of primordial black holes may also be detectable. These phenomena and a zoo of astrophysical objects will be the targets of the next...

  15. Gemini Planet Imager Coronagraph Testbed Results

    Sivaranmakrishnan, A.; Carr, G.; Soummer, R.; Oppenheimer, B.R.; Mey, J.L.; Brenner, D.; Mandeville, C.W.; Zimmerman, N. Macintosh, B.A.; Graham, J.R.; Saddlemyer, L.; Bauman, B.; Carlotti, A.; Pueyo, L.; Tuthill, P.G.; Dorrer, C.; Roberts, R.; Greenbaum, A.


    The Gemini Planet Imager (GPI) is an extreme AO coronagraphic integral field unit YJHK spectrograph destined for first light on the 8m Gemini South telescope in 2011. GPI fields a 1500 channel AO system feeding an apodized pupil Lyot coronagraph, and a nIR non-common-path slow wavefront sensor. It targets detection and characterizion of relatively young (<2GYr), self luminous planets up to 10 million times as faint as their primary star. We present the coronagraph subsystem's in-lab performance, and describe the studies required to specify and fabricate the coronagraph. Coronagraphic pupil apodization is implemented with metallic half-tone screens on glass, and the focal plane occulters are deep reactive ion etched holes in optically polished silicon mirrors. Our JH testbed achieves H-band contrast below a million at separations above 5 resolution elements, without using an AO system. We present an overview of the coronagraphic masks and our testbed coronagraphic data. We also demonstrate the performance of an astrometric and photometric grid that enables coronagraphic astrometry relative to the primary star in every exposure, a proven technique that has yielded on-sky precision of the order of a milliarsecond.

  16. One-Dimensional-Ratio Measures of Atrophy Progression in Multiple Sclerosis as Evaluated by Longitudinal Magnetic Resonance Imaging

    Martola, J.; Wiberg Kristoffersen, M.; Aspelin, P. (Div. of Radiology, Dept. of Clinical Science, Intervention and Technology, Karolinska Inst., Stockholm (Sweden)); Stawiarz, L.; Fredrikson, S.; Hillert, J. (Div. of Neurology, Dept. of Clinical Neuroscience, Karolinska Inst., Stockholm (Sweden)); Bergstroem, J. (Medical Statistics Unit, Dept. of Learning, Informatics, Management, and Ethics (LIME), Karolinska Inst., Stockholm (Sweden)); Flodmark, O. (Dept. of Neuroradiology, Karolinska Univ. Hospital, Stockholm (Sweden))


    Background: For decades, normalized one-dimensional (1D) measures have been used in the evaluation of brain atrophy. In multiple sclerosis (MS), the use of normalized linear measures over longitudinal follow-up remains insufficiently documented. Purpose: To evaluate the association between different regional atrophy measures and disability in MS patients over four decades in a longitudinal cross-sectional study. Material and Methods: 37 consecutively selected MS patients were included. At baseline, patients had a range of disease duration (1-33 years) and age (24-65 years). Each patient was followed by magnetic resonance imaging (MRI) for a mean of 9.25 years (range 7.3-10 years). Four 1D measures were applied at three time points on axial 5-mm T1-weighted images. Three clinical MS subgroups were represented: relapsing-remitting MS (RRMS), secondary progressive MS (SPMS), and primary progressive MS (PPMS). Results: There were significant changes in all 1D ratios during follow-up. The Evans ratio (ER) and the bifrontal ratio (BFR) were associated with the development of disability. Changes of ER and BFR reflected more aggressive disease progression, as expressed by MS severity score (MSSS). Conclusion: All four normalized ratios showed uniform atrophy progression, suggesting a consistent rate of atrophy over long-term disease duration independent of MS course. Disability status correlated with 1D measures, suggesting that serial evaluation of Evans and bifrontal ratios might contribute to the radiological evaluation of MS patients.

  17. Application of input amplitude masks in image encryption with spatially incoherent illumination for increase of decrypted images signal-to-noise ratio

    Cheremkhin, Pavel A.; Evtikhiev, Nikolay N.; Krasnov, Vitaly V.; Molodtsov, Dmitriy Y.; Rodin, Vladislav G.; Shifrina, Anna V.


    The majority of existing methods of optical encryption use not only light intensity distribution, easily registered with photosensors, but also its phase distribution. This provides best encryption strength for fixed quantities of elements and phase levels in a mask. Downsides are holographic registration scheme used in order to register not only light intensity distribution but also its phase distribution and speckle noise occurring due to coherent illumination. That factors lead to very poor decryption quality when it comes from computer simulations to optical implementations. Method of optical encryption with spatially incoherent illumination does not have drawbacks inherent to coherent systems, however, as only light intensity distribution is considered, mean value of image to be encrypted is always above zero which leads to intensive zero spatial frequency peak in image spectrum. Therefore, in case of spatially incoherent illumination, image spectrum, as well as encryption key spectrum, cannot be white. If encryption is based on convolution operation, no matter coherent light used or not, Fourier spectrum amplitude distribution of encryption key should overlap Fourier spectrum amplitude distribution of image to be encrypted otherwise loss of information is unavoidable. Another factor affecting decrypted image quality is original image spectrum. Usually, most part of image energy is concentrated in area of low frequencies. Consequently, only this area in encrypted image contains information about original image, while other areas contain only noise. We propose to use additional encoding of input scene to increase size of the area containing useful information. This provides increase of signal-to-noise ratio in encrypted image and consequentially increases quality of decrypted images. Results of computer simulations of test images optical encryption with spatially incoherent illumination and additional input amplitude masks are presented.

  18. Automatic Insall-Salvati ratio measurement on lateral knee x-ray images using model-guided landmark localization

    Chen, Hsin-Chen; Wu, Chia-Hsing; Sun, Yung-Nien [Department of Computer Science and Information Engineering, National Cheng Kung University, 1 University Road, Tainan 701, Taiwan (China); Lin, Chii-Jeng [Department of Orthopedics, College of Medicine, National Cheng Kung University, 138 Sheng Li Road, Tainan 704, Taiwan (China); Wang, Chien-Kuo, E-mail:, E-mail:, E-mail:, E-mail:, E-mail: [Department of Radiology, National Cheng Kung University Hospital, 138 Sheng Li Road, Tainan 704, Taiwan (China)


    The Insall-Salvati ratio (ISR) is important for detecting two common clinical signs of knee disease: patella alta and patella baja. Furthermore, large inter-operator differences in ISR measurement make an objective measurement system necessary for better clinical evaluation. In this paper, we define three specific bony landmarks for determining the ISR and then propose an x-ray image analysis system to localize these landmarks and measure the ISR. Due to inherent artifacts in x-ray images, such as unevenly distributed intensities, which make landmark localization difficult, we hence propose a registration-assisted active-shape model (RAASM) to localize these landmarks. We first construct a statistical model from a set of training images based on x-ray image intensity and patella shape. Since a knee x-ray image contains specific anatomical structures, we then design an algorithm, based on edge tracing, for patella feature extraction in order to automatically align the model to the patella image. We can estimate the landmark locations as well as the ISR after registration-assisted model fitting. Our proposed method successfully overcomes drawbacks caused by x-ray image artifacts. Experimental results show great agreement between the ISRs measured by the proposed method and by orthopedic clinicians.

  19. Improved method for predicting the peak signal-to-noise ratio quality of decoded images in fractal image coding

    Wang, Qiang; Bi, Sheng


    To predict the peak signal-to-noise ratio (PSNR) quality of decoded images in fractal image coding more efficiently and accurately, an improved method is proposed. After some derivations and analyses, we find that the linear correlation coefficients between coded range blocks and their respective best-matched domain blocks can determine the dynamic range of their collage errors, which can also provide the minimum and the maximum of the accumulated collage error (ACE) of uncoded range blocks. Moreover, the dynamic range of the actual percentage of accumulated collage error (APACE), APACEmin to APACEmax, can be determined as well. When APACEmin reaches a large value, such as 90%, APACEmin to APACEmax will be limited in a small range and APACE can be computed approximately. Furthermore, with ACE and the approximate APACE, the ACE of all range blocks and the average collage error (ACER) can be obtained. Finally, with the logarithmic relationship between ACER and the PSNR quality of decoded images, the PSNR quality of decoded images can be predicted directly. Experiments show that compared with the previous similar method, the proposed method can predict the PSNR quality of decoded images more accurately and needs less computation time simultaneously.

  20. Signal-to-noise ratio improvements in laser flow diagnostics using time-resolved image averaging and high dynamic range imaging

    Giassi, Davide; Long, Marshall B.


    Two alternative image readout approaches are demonstrated to improve the signal-to-noise ratio (SNR) in temporally resolved laser-based imaging experiments of turbulent phenomena. The first method exploits the temporal decay characteristics of the phosphor screens of image intensifiers when coupled to an interline-transfer CCD camera operated in double-frame mode. Specifically, the light emitted by the phosphor screen, which has a finite decay constant, is equally distributed and recorded over the two sequential frames of the detector so that an averaged image can be reconstructed. The characterization of both detector and image intensifier showed that the technique preserves the correct quantitative information, and its applicability to reactive flows was verified using planar Rayleigh scattering and tested with the acquisition of images of both steady and turbulent partially premixed methane/air flames. The comparison between conventional Rayleigh results and the averaged ones showed that the SNR of the averaged image is higher than the conventional one; with the setup used in this work, the gain in SNR was seen to approach 30 %, for both the steady and turbulent cases. The second technique uses the two-frame readout of an interline-transfer CCD to increase the image SNR based on high dynamic range imaging, and it was tested in an unsteady non-reactive flow of Freon-12 injected in air. The result showed a 15 % increase in the SNR of the low-pixel-count regions of an image, when compared to the pixels of a conventionally averaged one.

  1. Image deblurring applied to infrared tongue position imaging: Initial simulation results

    Poots, J. Kent


    Paper describes development work for a new biomedical application of image deblurring. Optical imaging is not currently used to assess tongue position during speech, nor is optical imaging the modality of choice for imaging tissue of moderate thickness. Tongue position assessment is important during rehabilitation. Optical imaging of biological tissue provides good contrast, but incident light is scattered, seriously restricting clinical usefulness. Paper describes simulation results for scattering correction and suggests possible directions for future work. Images are represented by sparse matrices.

  2. Novel approach for improving signal to noise ratio of seismic images

    陈凤; 李金宗; 李冬冬


    A novel approach of digital image processing technology is applied to improve SNR of seismic images. At first,we analyze the characters of line-like texture in seismic images, and then a preprocessing method named 2 D tracing horizon filtering is designed. After that, the technology of optical flow analysis is adopted to calculate the displacement vectors of adjacent pixels between neighboring seismic images. At last, the novel image accumulation algorithms are proposed, which are applied to greatly improve SNR and definition of seismic images. The experimental results show that SNR of seismic section images with SNR of about 20 dB and 17 dB are increased 8 dB~9 dB under keeping signal energy 67%~80% by processing section images and 3dB~4dB under keeping signalenergy 80~90% by processing horizontal slice images. Thereby, the proposed novel approaches are very helpful to the correct seismic interpretation and have very important significance for seismic exploring.

  3. Detection of Bleeding in Wireless Capsule Endoscopy Images Using Range Ratio Color

    Al-Rahayfeh, Amer A; 10.5121/ijma.2010.2201


    Wireless Capsule Endoscopy (WCE) is device to detect abnormalities in colon,esophagus,small intestinal and stomach, to distinguish bleeding in WCE images from non bleeding is a hard job by human reviewing and very time consuming. Consequently, automation for classifying bleeding frames not only will expedite the process but will reduce the burden on the doctors. Using the purity of the red color we can detect the Bleeding areas in WCE images. But, we could find various intensity of red color values in different parts of the small intestinal,so it is not enough to depend on the red color feature alone. We select RGB(Red,Green,Blue) because it takes raw level values and it is easy to use. In this paper we will put range ratio color for each of R,G,and B. Therefore, we divide each image into multiple pixels and apply the range ratio color condition for each pixel. Then we count the number of the pixels that achieved our condition. If the number of pixels grater than zero, then the frame is classified as a bleedi...

  4. Ultrasensitive fluorescent ratio imaging probe for the detection of glutathione ultratrace change in mitochondria of cancer cells.

    Zhang, Hua; Wang, Caixia; Wang, Kui; Xuan, Xiaopeng; Lv, Qingzhang; Jiang, Kai


    Glutathione (GSH) ultratrace change in mitochondria of cancer cells can mildly and effectively induce cancer cells apoptosis in early stage. Thus, if GSH ultratrace change in mitochondria of cancer cells could be recognized and imaged, it will be beneficial for fundamental research of cancer therapy. There have reported a lot of fluorescent probes for GSH, but the fluorescent probe with ultrasensitivity and high selectivity for the ratio imaging of GSH ultratrace changes in mitochondria of cancer cells is scarce. Herein, based on different reaction mechanism of sulfonamide under different pH, a sulfonamide-based reactive ratiometric fluorescent probe (IQDC-M) was reported for the recognizing and imaging of GSH ultratrace change in mitochondria of cancer cells. The detection limit of IQDC-M for GSH ultratrace change is low to 2.02nM, which is far less than 1.0‰ of endogenic GSH in living cells. And during the recognition process, IQDC-M can emit different fluorescent signals at 520nm and 592nm, which results in it recognizing GSH ultratrace change on ratio mode. More importantly, IQDC-M recognizing GSH ultratrace change specifically occurs in mitochondria of cancer cells because of appropriate water/oil amphipathy (log P) of IQDC-M. So, these make IQDC-M possible to image and monitor GSH ultratrace change in mitochondria during cancer cells apoptosis for the first time. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Surrogate/spent fuel sabotage : aerosol ratio test program and Phase 2 test results.

    Borek, Theodore Thaddeus III; Thompson, N. Slater (U.S. Department of Energy); Sorenson, Ken Bryce; Hibbs, R.S. (U.S. Department of Energy); Nolte, Oliver (Fraunhofer Institut fur Toxikologie und Experimentelle Medizin, Germany); Molecke, Martin Alan; Autrusson, Bruno (Institut de Radioprotection et de Surete Nucleaire, France); Young, F. I. (U.S. Nuclear Regulatory Commission); Koch, Wolfgang (Fraunhofer Institut fur Toxikologie und Experimentelle Medizin, Germany); Brochard, Didier (Institut de Radioprotection et de Surete Nucleaire, France); Pretzsch, Gunter Guido (Gesellschaft fur Anlagen- und Reaktorsicherheit, Germany); Lange, Florentin (Gesellschaft fur Anlagen- und Reaktorsicherheit, Germany)


    A multinational test program is in progress to quantify the aerosol particulates produced when a high energy density device, HEDD, impacts surrogate material and actual spent fuel test rodlets. This program provides needed data that are relevant to some sabotage scenarios in relation to spent fuel transport and storage casks, and associated risk assessments; the program also provides significant political benefits in international cooperation. We are quantifying the spent fuel ratio, SFR, the ratio of the aerosol particles released from HEDD-impacted actual spent fuel to the aerosol particles produced from surrogate materials, measured under closely matched test conditions. In addition, we are measuring the amounts, nuclide content, size distribution of the released aerosol materials, and enhanced sorption of volatile fission product nuclides onto specific aerosol particle size fractions. These data are crucial for predicting radiological impacts. This document includes a thorough description of the test program, including the current, detailed test plan, concept and design, plus a description of all test components, and requirements for future components and related nuclear facility needs. It also serves as a program status report as of the end of FY 2003. All available test results, observations, and analyses - primarily for surrogate material Phase 2 tests using cerium oxide sintered ceramic pellets are included. This spent fuel sabotage - aerosol test program is coordinated with the international Working Group for Sabotage Concerns of Transport and Storage Casks, WGSTSC, and supported by both the U.S. Department of Energy and Nuclear Regulatory Commission.

  6. Variability in the results of inr (international normalized ratio: a comparison of six commercial thromboplastin brands

    Fernanda Daniela Serralvo


    Full Text Available Introduction: The efficacy and safety in treatment with oral anticoagulants are dependent on the monitoring of the effect of anticoagulants by the prothrombin time (PT. The system INR (International Normalized Ratio was developed to minimize the variability in the PT, mainly because of the thromboplastin reagent used. Objective: Compare the results of INR employing six thromboplastins and plasmas of patients using oral anticoagulants. Materials and Methods: For this study, 96 patients using oral anticoagulants and that had TP collected for monitoring anticoagulants were selected randomly. INR values were determined using six commercially available thromboplastin brands. Results and Discussion: Of the 96 patients, 29 were with the INR between 2 and 3 when used reagents Dade-Behring®, Human do Brasil® and Diagnostica Stago®. Regardless of the range of INR, the results obtained with the reagent Labtest® were statistically different from the Dade-Behring®, from Diagnostica Stago®, Trinity Biotech and Bios Diagnostica®. With INR between 2 and 3 only differences were observed between the results of brands and Bios Diagnostica® Labtest®. With INR above 3, the results of Labtest® were different from the Dade-Behring®, from Diagnostica Stago®, Trinity Biotech® and Bios Diagnostica®. Conclusion: Despite the establishment of INR, there are still significant differences in INR results depending on the thromboplastin brand used, which can interfere with the therapeutic approach in relation to oral anticoagulants.

  7. Phase-aligned multiple spin-echo averaging: a simple way to improve signal-to-noise ratio of in vivo mouse spinal cord diffusion tensor image.

    Tu, Tsang-Wei; Budde, Matthew D; Xie, Mingqiang; Chen, Ying-Jr; Wang, Qing; Quirk, James D; Song, Sheng-Kwei


    reflected pathological features in contusion spinal cord injury. Our in vivo imaging results indicate that averaging the phased multiple spin-echo images yields an 84% signal-noise-ratio increase over the spin-echo images and a 41% gain over the magnitude averaged multiple spin-echo images with equal acquisition time. Current results from the animal model of spinal cord injury suggest that the phased multiple spin-echo images could be used to improve signal-noise-ratio. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Age estimation using pulp/tooth area ratio: A digital image analysis

    Sasidhar Singaraju


    Full Text Available Age is one of the essential factors in establishing the identity of the person. Estimation of the human age is a procedure adopted by anthropologists, archeologists, and forensic scientists. Inspection of radiographs and subsequent comparison with radiographic images, in charts yield ′maturity scores′ that help us to assess the age of an individual. Alternative approaches based on digitalization of panoramic radiographs and their computerized storage have recently become available that exploit image analysis to obtain nondestructive metric measurements of both pulp chambers and teeth, which can be used to assess the age of an individual. The purpose of the present study was to present a method for assessing the chronological age based on the relationship between age and measurement of the pulp/tooth area ratio on single-rooted teeth, using orthopantomographs and a computer-aided drafting program AutoCAD 2000.

  9. Using the ratio of means as the effect size measure in combining results of microarray experiments

    Greenwood Celia MT


    Full Text Available Abstract Background Development of efficient analytic methodologies for combining microarray results is a major challenge in gene expression analysis. The widely used effect size models are thought to provide an efficient modeling framework for this purpose, where the measures of association for each study and each gene are combined, weighted by the standard errors. A significant disadvantage of this strategy is that the quality of different data sets may be highly variable, but this information is usually neglected during the integration. Moreover, it is widely known that the estimated standard deviations are probably unstable in the commonly used effect size measures (such as standardized mean difference when sample sizes in each group are small. Results We propose a re-parameterization of the traditional mean difference based effect measure by using the log ratio of means as an effect size measure for each gene in each study. The estimated effect sizes for all studies were then combined under two modeling frameworks: the quality-unweighted random effects models and the quality-weighted random effects models. We defined the quality measure as a function of the detection p-value, which indicates whether a transcript is reliably detected or not on the Affymetrix gene chip. The new effect size measure is evaluated and compared under the quality-weighted and quality-unweighted data integration frameworks using simulated data sets, and also in several data sets of prostate cancer patients and controls. We focus on identifying differentially expressed biomarkers for prediction of cancer outcomes. Conclusion Our results show that the proposed effect size measure (log ratio of means has better power to identify differentially expressed genes, and that the detected genes have better performance in predicting cancer outcomes than the commonly used effect size measure, the standardized mean difference (SMD, under both quality-weighted and quality

  10. Evaluation of some ratio effects in 99mTc-MIBI imaging of breast tumors


    The effectiveness of using some ratios in 99mTc-MIBI imaging fbr the diagnosis of breast tumors was evaluated. After 100 patients with the breast tumor underwent 99mTc-MIBI imaging, the ratios of tunor to contralateral uptake (T/N). tumor to heart uptake (T/H), and tumor to sternum uptake (T/S) were obtained and then analysed about their reproducibility and values in differentiating benign breast lesion the from malignant tumor. To detect breast cancers, the sensitivity, specificit y and accuracy of T/N were 92%, 90% and 91%, respectively. However, those of T/S were 70% (p <0.01), 74% (p <0.05), 72% (p <0.01), and those of T/H were 74%(p <0.05). 76% (p >0.05). 75% (p <0.01). The average coefticients of variation(CV) of T/N, T/S and T/H were 9.439±9.712. 4.856+4.420 (p >0.05), and 3.736±3.489 (p <0.05). It was found that T/N had the best sensitivity, specificity and accuracy todetect the breast cancer, but its reproducibility is poor. On the other hand, T/H has better reproducibility.

  11. Woody-to-total area ratio determination with a multispectral canopy imager.

    Zou, Jie; Yan, Guangjian; Zhu, Ling; Zhang, Wuming


    Leaf area index (LAI) - defined as one half of the total green leaf area per unit ground surface area - can be determined by direct or indirect methods. Three major sources of errors exist in indirect LAI measurements: within-shoot clumping, beyond-shoot clumping and non-photosynthetic components. The effect of non-photosynthetic components on LAI measurements can be described by the woody-to-total area ratio, alpha; however, no convenient and efficient indirect methods have been developed to estimate alpha, especially the variations in alpha with zenith angle , alpha(theta). We describe the development and use of a multispectral canopy imager (MCI) to estimate alpha and alpha(theta) by considering the effects of non-random distributions of canopy elements and woody components and the overestimation of needle-to-shoot area ratio on woody components. The MCI, which mainly comprises a near-infrared band camera (Fujifilm IS-1), two visible band cameras (Canon 40D), filters and a pan tilt, was developed to measure clumping index, woody-to-total area ratio and geometric parameters of isolated trees. Two typical sampling plots (Plots 1 and 5) chosen from among 16 permanent forest experiment plots were selected for the estimation of alpha and alpha(theta). The non-random distributions of canopy elements and woody components were estimated separately at eight zenith angles (from 0 degrees to 70 degrees in increments of 10 degrees) using MCI images based on the gap size distribution theory. The visible/near-infrared image pairs captured by the MCI were able to discriminate among sky, leaves, cloud and woody components. Based on three methods of estimation, we obtained woody-to-total area ratios of 0.24, 0.19, 0.19 for Plot 1 and 0.23, 0.18, 0.17 for Plot 5. If clumping effects were ignored, alpha values were overestimated by as much as 21% and 24% at Plots 1 and 5, respectively. We demonstrated that alpha(theta) varied with the zenith angle, with variations in the range of

  12. Results from neutron imaging of ICF experiments at NIF

    Merrill, F. E.; Danly, C. R.; Fittinghoff, D. N.; Grim, G. P.; Guler, N.; Volegov, P. L.; Wilde, C. H.


    In 2011 a neutron imaging diagnostic was commissioned at the National Ignition Facility (NIF). This new system has been used to collect neutron images to measure the size and shape of the burning DT plasma and the surrounding fuel assembly. The imaging technique uses a pinhole neutron aperture placed between the neutron source and a neutron detector. The detection system measures the two-dimensional distribution of neutrons passing through the pinhole. This diagnostic collects two images at two times. The long flight path for this diagnostic, 28 m, results in a chromatic separation of the neutrons, allowing the independently timed images to measure the source distribution for two neutron energies. Typically one image measures the distribution of the 14 MeV neutrons, and the other image measures the distribution of the 6-12 MeV neutrons. The combination of these two images has provided data on the size and shape of the burning plasma within the compressed capsule, as well as a measure of the quantity and spatial distribution of the cold fuel surrounding this core. Images have been collected for the majority of the experiments performed as part of the ignition campaign. Results from this data have been used to estimate a burn-averaged fuel assembly as well as providing performance metrics to gauge progress towards ignition. This data set and our interpretation are presented.

  13. Directly Imaging Planets with SCExAO: First Results

    Currie, Thayne M.; Guyon, Olivier; Jovanovic, Nemanja; Lozi, Julien; Tamura, Motohide; Kudo, Tomoyuki; Uyama, Taichi; Garcia, Eugenio


    We present the first science results from the newly commissioned Subaru Coronagraphic Extreme Adaptive Optics project, an experimental system dedicated to image faint jovian planets around nearby stars. SCExAO is now achieving true extreme AO capability. We describe the typical performance of SCExAO, the first images of benchmark exoplanets and planet-forming disks, and SCExAO’s first science results. Finally, we briefly chart the path forward for SCExAO to achieve its full scientific capability, including imaging mature planets in reflected light.

  14. Winning the genetic lottery: biasing birth sex ratio results in more grandchildren.

    Collette M Thogerson

    Full Text Available Population dynamics predicts that on average parents should invest equally in male and female offspring; similarly, the physiology of mammalian sex determination is supposedly stochastic, producing equal numbers of sons and daughters. However, a high quality parent can maximize fitness by biasing their birth sex ratio (SR to the sex with the greatest potential to disproportionately outperform peers. All SR manipulation theories share a fundamental prediction: grandparents who bias birth SR should produce more grandoffspring via the favored sex. The celebrated examples of biased birth SRs in nature consistent with SR manipulation theories provide compelling circumstantial evidence. However, this prediction has never been directly tested in mammals, primarily because the complete three-generation pedigrees needed to test whether individual favored offspring produce more grandoffspring for the biasing grandparent are essentially impossible to obtain in nature. Three-generation pedigrees were constructed using 90 years of captive breeding records from 198 mammalian species. Male and female grandparents consistently biased their birth SR toward the sex that maximized second-generation success. The most strongly male-biased granddams and grandsires produced respectively 29% and 25% more grandoffspring than non-skewing conspecifics. The sons of the most male-biasing granddams were 2.7 times as fecund as those of granddams with a 50∶50 bias (similar results are seen in grandsires. Daughters of the strongest female-biasing granddams were 1.2 times as fecund as those of non-biasing females (this effect is not seen in grandsires. To our knowledge, these results are the first formal test of the hypothesis that birth SR manipulation is adaptive in mammals in terms of grandchildren produced, showing that SR manipulation can explain biased birth SR in general across mammalian species. These findings also have practical implications: parental control of birth

  15. Spatial harmonic imaging of X-ray scattering--initial results.

    Wen, Han; Bennett, Eric E; Hegedus, Monica M; Carroll, Stefanie C


    Coherent X-ray scattering is related to the electron density distribution by a Fourier transform, and therefore a window into the microscopic structures of biological samples. Current techniques of scattering rely on small-angle measurements from highly collimated X-ray beams produced from synchrotron light sources. Imaging of the distribution of scattering provides a new contrast mechanism which is different from absorption radiography, but is a lengthy process of raster or line scans of the beam over the object. Here, we describe an imaging technique in the spatial frequency domain capable of acquiring both the scattering and absorption distributions in a single exposure. We present first results obtained with conventional X-ray equipment. This method interposes a grid between the X-ray source and the imaged object, so that the grid-modulated image contains a primary image and a grid harmonic image. The ratio between the harmonic and primary images is shown to be a pure scattering image. It is the auto-correlation of the electron density distribution at a specific distance. We tested a number of samples at 60-200 nm autocorrelation distance, and found the scattering images to be distinct from the absorption images and reveal new features. This technique is simple to implement, and should help broaden the imaging applications of X-ray scattering.

  16. Result Analysis of Blur and Noise on Image Denoising based on PDE

    Meenal Jain


    Full Text Available The effect of noise on image is still a challenging problem for researchers. Image Denoising has remained a fundamental problem in the field of image processing. Wavelets give a superior performance in image denoising due to properties such as sparsity and multi resolution structure. Many of the previous research use the basic noise reduction through image blurring. Blurring can be done locally, as in the Gaussian smoothing model or in anisotropic filtering; by calculus of variations; or in the frequency domain, such as Weiner filters. In this paper we proposed an image denoising method using partial differential equation. In our proposed approach we proposed three different approaches first is for blur, second is for noise and finally for blur and noise. These approaches are compared by Average absolute difference, signal to noise ratio (SNR, peak signal to noise ratio (PSNR, Image Fidelity and Mean square error. So we can achieve better result on different scenario. We also compare our result on the basis of the above five parameters and the result is better in comparison to the traditional technique.

  17. Image transmission over OFDM channel with rate allocation scheme and minimum peak-toaverage power ratio

    Mohammed, Usama S


    This paper proposes new scheme for efficient rate allocation in conjunction with reducing peak-to-average power ratio (PAPR) in orthogonal frequency-division multiplexing (OFDM) systems. Modification of the set partitioning in hierarchical trees (SPIHT) image coder is proposed to generate four different groups of bit-stream relative to its significances. The significant bits, the sign bits, the set bits and the refinement bits are transmitted in four different groups. The proposed method for reducing the PAPR utilizes twice the unequal error protection (UEP), using the Read-Solomon codes (RS), in conjunction with bit-rate allocation and selective interleaving to provide minimum PAPR. The output bit-stream from the source code (SPIHT) will be started by the most significant types of bits (first group of bits). The optimal unequal error protection (UEP) of the four groups is proposed based on the channel destortion. The proposed structure provides significant improvement in bit error rate (BER) performance. Per...

  18. To Improvement in Image Compression ratio using Artificial Neural Network Technique

    Shabbir Ahmad


    Full Text Available Compression of data in any form is a large and active field as well as a big business. This paper presents a neural network based technique that may be applied to data compression. This paper breaks down large images into smaller windows and eliminates redundant information. Finally, the technique uses a neural network trained by direct solution methods. Conventional techniques such as Huffman coding and the Shannon Fano method, LZ Method, Run Length Method, LZ-77 are discussed as well as more recent methods for the compression of data presents a neural network based technique that may be applied to data compression. The proposed technique and images. Intelligent methods for data compression are reviewed including the use of Back propagation and Kohonen neural networks. The proposed technique has been implemented in C on the SP2 and tested on digital mammograms and other images. The results obtained are presented in this paper.

  19. SPOT4 HRVIR first in-flight image quality results

    Kubik, Philippe; Breton, Eric; Meygret, Aime; Cabrieres, Bernard; Hazane, Philippe; Leger, Dominique


    The SPOT4 remote sensing satellite was successfully launched at the end of March 1998. It was designed first of all to guarantee continuity of SPOT services beyond the year 2000 but also to improve the mission. Its two cameras are now called HRVIR since a short-wave infrared (SWIR) spectral band has been added. Like their predecessor HRV cameras, they provide 20-meter multispectral and 10-meter monospectral images with a 60 km swath for nadir viewing. SPOT4's first two months of life in orbit were dedicated to the evaluation of its image quality performances. During this period of time, the CNES team used specific target programming in order to compute image correction parameters and estimate the performance, at system level, of the image processing chain. After a description of SPOT4 system requirements and new features of the HRVIR cameras, this paper focuses on the performance deduced from in-flight measurements, methods used and their accuracy: MTF measurements, refocusing, absolute calibration, signal-to-noise Ratio, location, focal plane cartography, dynamic disturbances.

  20. Theoretical signal-to-noise ratio of a slotted surface coil for magnetic resonance imaging

    Ocegueda, K; Solis, S E; Rodriguez, A O


    The analytical expression for the signal-to-noise ratio of a slotted surface coil with an arbitrary number of slots was derived using the quasi-static approach. This surface coil based on the vane-type magnetron tube. To study the coil perfomance, the theoretical signal-to-noise ratio predictions of this coil design were computed using a different number of slots. Results were also compared with theoretical results obtained for a circular coil with similar dimensions. It can be appreciated that slotted surface coil performance improves as the number of coils increases and, outperformed the circular-shaped coil. This makes it a good candidate for other MRI applications involving coil array techniques.

  1. Comparison of contrast-to-noise ratios of transmission and dark-field signal in grating-based X-ray imaging for healthy murine lung tissue

    Schwab, Felix [Ludwig Maximilians-Univ. Hospital Munich (Germany). Inst. for Clinical Radiology; Schleede, Simone; Hahn, Dieter [Technische Univ. Muenchen, Garching (Germany). Dept. of Physics and Inst. of Medical Engineering] [and others


    Purpose: An experimental comparison of the contrast-to-noise ratio (CNR) between transmission and dark-field signals in grating-based X-ray imaging for ex-vivo murine lung tissue. Materials and Methods: Lungs from three healthy mice were imaged ex vivo using a laser-driven compact synchrotron X-ray source. Background noise of transmission and dark-field signal was quantified by measuring the standard deviation in a region of interest (ROI) placed in a homogeneous area outside the specimen. Image contrast was quantified by measuring the signal range in rectangular ROIs placed in central and peripheral lung parenchyma. The relative contrast gain (RCG) of dark-field over transmission images was calculated as CNRDF / CNRT. Results: In all images, there was a trend for contrast-to-noise ratios of dark-field images (CNRDF) to be higher than for transmission images (CNRT) for all ROIs (median 61 vs. 38, p = 0.10), but the difference was statistically significant only for peripheral ROIs (61 vs. 32, p = 0.03). Median RCG was >1 for all ROIs (1.84). RCG values were significantly smaller for central ROIs than for peripheral ROIs (1.34 vs. 2.43, p = 0.03). Conclusion: The contrast-to-noise ratio of dark-field images compares more favorably to the contrast-to-noise ratio of transmission images for peripheral lung regions as compared to central regions. For any specific specimen, a calculation of the RCG allows comparing which X-ray modality (dark-field or transmission imaging) produces better contrast-to-noise characteristics in a well-defined ROI. (orig.)

  2. Implementation of intensity ratio change and line-of-sight rate change algorithms for imaging infrared trackers

    Viau, C. R.


    The use of the intensity change and line-of-sight (LOS) change concepts have previously been documented in the open-literature as techniques used by non-imaging infrared (IR) seekers to reject expendable IR countermeasures (IRCM). The purpose of this project was to implement IR counter-countermeasure (IRCCM) algorithms based on target intensity and kinematic behavior for a generic imaging IR (IIR) seeker model with the underlying goal of obtaining a better understanding of how expendable IRCM can be used to defeat the latest generation of seekers. The report describes the Intensity Ratio Change (IRC) and LOS Rate Change (LRC) discrimination techniques. The algorithms and the seeker model are implemented in a physics-based simulation product called Tactical Engagement Simulation Software (TESS™). TESS is developed in the MATLAB®/Simulink® environment and is a suite of RF/IR missile software simulators used to evaluate and analyze the effectiveness of countermeasures against various classes of guided threats. The investigation evaluates the algorithm and tests their robustness by presenting the results of batch simulation runs of surface-to-air (SAM) and air-to-air (AAM) IIR missiles engaging a non-maneuvering target platform equipped with expendable IRCM as self-protection. The report discusses how varying critical parameters such track memory time, ratio thresholds and hold time can influence the outcome of an engagement.

  3. Learned dictionaries for sparse image representation: properties and results

    Skretting, Karl; Engan, Kjersti


    Sparse representation of images using learned dictionaries have been shown to work well for applications like image denoising, impainting, image compression, etc. In this paper dictionary properties are reviewed from a theoretical approach, and experimental results for learned dictionaries are presented. The main dictionary properties are the upper and lower frame (dictionary) bounds, and (mutual) coherence properties based on the angle between dictionary atoms. Both l0 sparsity and l1 sparsity are considered by using a matching pursuit method, order recursive matching Pursuit (ORMP), and a basis pursuit method, i.e. LARS or Lasso. For dictionary learning the following methods are considered: Iterative least squares (ILS-DLA or MOD), recursive least squares (RLS-DLA), K-SVD and online dictionary learning (ODL). Finally, it is shown how these properties relate to an image compression example.

  4. Atmospheric Modelling for Neptune's Methane D/H Ratio - Preliminary Results

    Cotton, Daniel V; Bott, Kimberly; Bailey, Jeremy


    The ratio of deuterium to hydrogen (D/H ratio) of Solar System bodies is an important clue to their formation histories. Here we fit a Neptunian atmospheric model to Gemini Near Infrared Spectrograph (GNIRS) high spectral resolution observations and determine the D/H ratio in methane absorption in the infrared H-band ($\\sim$ 1.6 {\\mu}m). The model was derived using our radiative transfer software VSTAR (Versatile Software for the Transfer of Atmospheric Radiation) and atmospheric fitting software ATMOF (ATMOspheric Fitting). The methane line list used for this work has only become available in the last few years, enabling a refinement of earlier estimates. We identify a bright region on the planetary disc and find it to correspond to an optically thick lower cloud. Our preliminary determination of CH$_{\\rm 3}$D/CH$_{\\rm 4}$ is 3.0$\\times10^{-4}$, which is in line with the recent determination of Irwin et al. (2014) of 3.0$^{+1.0}_{-0.9}\\sim\\times10^{-4}$, made using the same model parameters and line list but...

  5. Preliminary results of Sr:Ca ratios of Coilia nasus in otoliths by micro-PIXE

    Zhong, L. [Institute of Modern Physics, Applied Ion Beam Physics Laboratory, Fudan University, Shanghai 200433 (China); Guo, H. [Institute of Life Science, Shanghai Fisheries University, Shanghai 200090 (China); Shen, H. [Institute of Modern Physics, Applied Ion Beam Physics Laboratory, Fudan University, Shanghai 200433 (China)]. E-mail:; Li, X. [Shanghai Institute of Applied Physics, Chinese Academy of Science, Shanghai 201800 (China); Tang, W. [Institute of Life Science, Shanghai Fisheries University, Shanghai 200090 (China); Liu, J. [Shanghai Institute of Applied Physics, Chinese Academy of Science, Shanghai 201800 (China); Jin, J. [Institute of Modern Physics, Applied Ion Beam Physics Laboratory, Fudan University, Shanghai 200433 (China); Mi, Y. [Institute of Modern Physics, Applied Ion Beam Physics Laboratory, Fudan University, Shanghai 200433 (China)


    Coilia nasus, distributed in Changjiang River as well as northwest Pacific, has a high economic value owing to its delicacy and nutritional value. Recently, the fishing yields in Changjiang River have decreased dramatically due to excessive fishing and changes in the aquatic ecology. In order to prevent excessive fishing effectively, the life history pattern of C. nasus should be known in detail. Ootoliths contain much information about a fish's life history, because elemental concentrations remain unaltered after deposition, and can be analysed. C. nasus collected from Jing Jiang (lower reaches of the Changjiang River) and Jiu Duan Sha (the estuary of the Changjiang River) were studied by measuring Sr:Ca ratios in their otoliths using micro-PIXE. On average, the Sr:Ca ratios of estuarine C. nasus were found to be higher. The Sr:Ca ratios were higher in the core regions and lower in the outermost marginal regions, and shows fluctuations in certain regions. Possible corresponding life history patterns are discussed.

  6. Investigate the variation in optical redox ratio of epicardial adipose tissue in patients with CAD through auto-fluorescence metabolic molecular image (Conference Presentation)

    Guo, Lun-Zhang; Wang, Tzung-Dau; Lin, Jong-Wei; Liu, Tzu-Ming


    In recent years, it has been suggested that epicardial adipose tissue (EAT) plays an important role in development of coronary artery disease (CAD) and diabetes mellitus (DM). In this article, we used two-photon fluoresce microscope to measure the fluorescence metabolic image of EAT, which obtained from the patient with/without CAD/DM. We used 740nm and 890nm infrared light to excite the auto-fluorescence of metabolic molecules NADH and FAD respectively. We collected the fluorescence signal at wavelength 450nm to 500nm and 500nm to 550nm to obtain the metabolic image. Through the image, we computed the redox ratio (NADH/FAD) by analyzing the intensity. The preliminary result showed that the redox ratio increase in the patients with CAD. It indicates EAT adipocytes of patient with CAD have decreased cellular metabolic activity. But there were no significant variation of redox ratio in the patients with DM.

  7. Projective rectification of infrared images from air-cooled condenser temperature measurement by using projection profile features and cross-ratio invariability.

    Xu, Lijun; Chen, Lulu; Li, Xiaolu; He, Tao


    In this paper, we propose a projective rectification method for infrared images obtained from the measurement of temperature distribution on an air-cooled condenser (ACC) surface by using projection profile features and cross-ratio invariability. In the research, the infrared (IR) images acquired by the four IR cameras utilized are distorted to different degrees. To rectify the distorted IR images, the sizes of the acquired images are first enlarged by means of bicubic interpolation. Then, uniformly distributed control points are extracted in the enlarged images by constructing quadrangles with detected vertical lines and detected or constructed horizontal lines. The corresponding control points in the anticipated undistorted IR images are extracted by using projection profile features and cross-ratio invariability. Finally, a third-order polynomial rectification model is established and the coefficients of the model are computed with the mapping relationship between the control points in the distorted and anticipated undistorted images. Experimental results obtained from an industrial ACC unit show that the proposed method performs much better than any previous method we have adopted. Furthermore, all rectified images are stitched together to obtain a complete image of the whole ACC surface with a much higher spatial resolution than that obtained by using a single camera, which is not only useful but also necessary for more accurate and comprehensive analysis of ACC performance and more reliable optimization of ACC operations.

  8. First Results of the Athena Microscopic Imager Investigation

    Herkenhoff, K.; Squyres, S.; Archinal, B.; Arvidson, R.; Bass, D.; Barrett, J.; Becker, K.; Becker, T.; Bell, J., III; Burr, D.


    The Athena science payload on the Mars Exploration Rovers (MER) includes the Microscopic Imager (MI). The MI is a fixed-focus camera mounted on an extendable arm, the Instrument Deployment Device (IDD). The MI acquires images at a spatial resolution of 30 microns/pixel over a broad spectral range (400 - 700 nm). The MI uses the same electronics design as the other MER cameras but its optics yield a field of view of 31 x 31 mm across a 1024 x 1024 pixel CCD image. The MI acquires images using only solar or skylight illumination of the target surface. A contact sensor is used to place the MI slightly closer to the target surface than its best focus distance (about 69 mm), allowing concave surfaces to be imaged in good focus. Coarse focusing (approx. 2 mm precision) is achieved by moving the IDD away from a rock target after contact is sensed. The MI optics are protected from the Martian environment by a retractable dust cover. This cover includes a Kapton window that is tinted orange to restrict the spectral bandpass to 500 - 700 nm, allowing crude color information to be obtained by acquiring images with the cover open and closed. The MI science objectives, instrument design and calibration, operation, and data processing were described by Herkenhoff et al. Initial results of the MI experiment on both MER rovers ('Spirit' and 'Opportunity') are described below.

  9. Estimating age ratios and size of pacific walrus herds on coastal haulouts using video imaging.

    Daniel H Monson

    Full Text Available During Arctic summers, sea ice provides resting habitat for Pacific walruses as it drifts over foraging areas in the eastern Chukchi Sea. Climate-driven reductions in sea ice have recently created ice-free conditions in the Chukchi Sea by late summer causing walruses to rest at coastal haulouts along the Chukotka and Alaska coasts, which provides an opportunity to study walruses at relatively accessible locations. Walrus age can be determined from the ratio of tusk length to snout dimensions. We evaluated use of images obtained from a gyro-stabilized video system mounted on a helicopter flying at high altitudes (to avoid disturbance to classify the sex and age of walruses hauled out on Alaska beaches in 2010-2011. We were able to classify 95% of randomly selected individuals to either an 8- or 3-category age class, and we found measurement-based age classifications were more repeatable than visual classifications when using images presenting the correct head profile. Herd density at coastal haulouts averaged 0.88 walruses/m(2 (std. err. = 0.02, herd size ranged from 8,300 to 19,400 (CV 0.03-0.06 and we documented ∼30,000 animals along ∼1 km of beach in 2011. Within the herds, dependent walruses (0-2 yr-olds tended to be located closer to water, and this tendency became more pronounced as the herd spent more time on the beach. Therefore, unbiased estimation of herd age-ratios will require a sampling design that allows for spatial and temporal structuring. In addition, randomly sampling walruses available at the edge of the herd for other purposes (e.g., tagging, biopsying will not sample walruses with an age structure representative of the herd. Sea ice losses are projected to continue, and population age structure data collected with aerial videography at coastal haulouts may provide demographic information vital to ongoing efforts to understand effects of climate change on this species.

  10. Estimating age ratios and size of pacific walrus herds on coastal haulouts using video imaging.

    Monson, Daniel H; Udevitz, Mark S; Jay, Chadwick V


    During Arctic summers, sea ice provides resting habitat for Pacific walruses as it drifts over foraging areas in the eastern Chukchi Sea. Climate-driven reductions in sea ice have recently created ice-free conditions in the Chukchi Sea by late summer causing walruses to rest at coastal haulouts along the Chukotka and Alaska coasts, which provides an opportunity to study walruses at relatively accessible locations. Walrus age can be determined from the ratio of tusk length to snout dimensions. We evaluated use of images obtained from a gyro-stabilized video system mounted on a helicopter flying at high altitudes (to avoid disturbance) to classify the sex and age of walruses hauled out on Alaska beaches in 2010-2011. We were able to classify 95% of randomly selected individuals to either an 8- or 3-category age class, and we found measurement-based age classifications were more repeatable than visual classifications when using images presenting the correct head profile. Herd density at coastal haulouts averaged 0.88 walruses/m(2) (std. err. = 0.02), herd size ranged from 8,300 to 19,400 (CV 0.03-0.06) and we documented ∼30,000 animals along ∼1 km of beach in 2011. Within the herds, dependent walruses (0-2 yr-olds) tended to be located closer to water, and this tendency became more pronounced as the herd spent more time on the beach. Therefore, unbiased estimation of herd age-ratios will require a sampling design that allows for spatial and temporal structuring. In addition, randomly sampling walruses available at the edge of the herd for other purposes (e.g., tagging, biopsying) will not sample walruses with an age structure representative of the herd. Sea ice losses are projected to continue, and population age structure data collected with aerial videography at coastal haulouts may provide demographic information vital to ongoing efforts to understand effects of climate change on this species.

  11. Sharp-Tip Silver Nanowires Mounted on Cantilevers for High-Aspect-Ratio High-Resolution Imaging.

    Ma, Xuezhi; Zhu, Yangzhi; Kim, Sanggon; Liu, Qiushi; Byrley, Peter; Wei, Yang; Zhang, Jin; Jiang, Kaili; Fan, Shoushan; Yan, Ruoxue; Liu, Ming


    Despite many efforts to fabricate high-aspect-ratio atomic force microscopy (HAR-AFM) probes for high-fidelity, high-resolution topographical imaging of three-dimensional (3D) nanostructured surfaces, current HAR probes still suffer from unsatisfactory performance, low wear-resistivity, and extravagant prices. The primary objective of this work is to demonstrate a novel design of a high-resolution (HR) HAR AFM probe, which is fabricated through a reliable, cost-efficient benchtop process to precisely implant a single ultrasharp metallic nanowire on a standard AFM cantilever probe. The force-displacement curve indicated that the HAR-HR probe is robust against buckling and bending up to 150 nN. The probes were tested on polymer trenches, showing a much better image fidelity when compared with standard silicon tips. The lateral resolution, when scanning a rough metal thin film and single-walled carbon nanotubes (SW-CNTs), was found to be better than 8 nm. Finally, stable imaging quality in tapping mode was demonstrated for at least 15 continuous scans indicating high resistance to wear. These results demonstrate a reliable benchtop fabrication technique toward metallic HAR-HR AFM probes with performance parallel or exceeding that of commercial HAR probes, yet at a fraction of their cost.

  12. Preliminary results of Sr/Ca ratio study of teeth samples by photoactivation analysis

    Kavun Yusuf


    Full Text Available In this paper, we have performed Photoactivation Analysis (PAA, a non-destructive method, which is used to determine elemental concentration of any sample. This paper presents the first use of this method in medical sciences in Turkey. The method was applied to the determination of Sr/Ca ratios in teeth. The collected teeth samples and standards (SrO and CaCO3 have been irradiated for a fixed time interval with high energy photons. The photons were generated by a clinical linear accelerator (cLINAC. The photon end-point energy was 18 MeV. The energy and the time interval were sufficient to achieve good activation. Afterward, the samples and standards have been analysed with gamma spectroscopic analysis by using an HPGe detector system. By analysing many samples, a database of Sr/Ca ratios will be created at Nuclear Research and Application Center (NUBA. In this paper we present a small subset of the already analysed data as an example of our capabilities and goal. We hope to set an example for future studies.

  13. Improvement of natural image search engines results by emotional filtering

    Patrice Denis


    Full Text Available With the Internet 2.0 era, managing user emotions is a problem that more and more actors are interested in. Historically, the first notions of emotion sharing were expressed and defined with emoticons. They allowed users to show their emotional status to others in an impersonal and emotionless digital world. Now, in the Internet of social media, every day users share lots of content with each other on Facebook, Twitter, Google+ and so on. Several new popular web sites like FlickR, Picassa, Pinterest, Instagram or DeviantArt are now specifically based on sharing image content as well as personal emotional status. This kind of information is economically very valuable as it can for instance help commercial companies sell more efficiently. In fact, with this king of emotional information, business can made where companies will better target their customers needs, and/or even sell them more products. Research has been and is still interested in the mining of emotional information from user data since then. In this paper, we focus on the impact of emotions from images that have been collected from search image engines. More specifically our proposition is the creation of a filtering layer applied on the results of such image search engines. Our peculiarity relies in the fact that it is the first attempt from our knowledge to filter image search engines results with an emotional filtering approach.

  14. Semi-automated measurements of heart-to-mediastinum ratio on 123I-MIBG myocardial scintigrams by using image fusion method with chest X-ray images

    Kawai, Ryosuke; Hara, Takeshi; Katafuchi, Tetsuro; Ishihara, Tadahiko; Zhou, Xiangrong; Muramatsu, Chisako; Abe, Yoshiteru; Fujita, Hiroshi


    MIBG (iodine-123-meta-iodobenzylguanidine) is a radioactive medicine that is used to help diagnose not only myocardial diseases but also Parkinson's diseases (PD) and dementia with Lewy Bodies (DLB). The difficulty of the segmentation around the myocardium often reduces the consistency of measurement results. One of the most common measurement methods is the ratio of the uptake values of the heart to mediastinum (H/M). This ratio will be a stable independent of the operators when the uptake value in the myocardium region is clearly higher than that in background, however, it will be unreliable indices when the myocardium region is unclear because of the low uptake values. This study aims to develop a new measurement method by using the image fusion of three modalities of MIBG scintigrams, 201-Tl scintigrams, and chest radiograms, to increase the reliability of the H/M measurement results. Our automated method consists of the following steps: (1) construct left ventricular (LV) map from 201-Tl myocardium image database, (2) determine heart region in chest radiograms, (3) determine mediastinum region in chest radiograms, (4) perform image fusion of chest radiograms and MIBG scintigrams, and 5) perform H/M measurements on MIBG scintigrams by using the locations of heart and mediastinum determined on the chest radiograms. We collected 165 cases with 201-Tl scintigrams and chest radiograms to construct the LV map. Another 65 cases with MIBG scintigrams and chest radiograms were also collected for the measurements. Four radiological technologists (RTs) manually measured the H/M in the MIBG images. We compared the four RTs' results with our computer outputs by using Pearson's correlation, the Bland-Altman method, and the equivalency test method. As a result, the correlations of the H/M between four the RTs and the computer were 0.85 to 0.88. We confirmed systematic errors between the four RTs and the computer as well as among the four RTs. The variation range of the H

  15. Prevalence of grey matter pathology in early multiple sclerosis assessed by magnetization transfer ratio imaging.

    Lydie Crespy

    Full Text Available The aim of the study was to assess the prevalence, the distribution and the impact on disability of grey matter (GM pathology in early multiple sclerosis. Eighty-eight patients with a clinically isolated syndrome with a high risk developing multiple sclerosis were included in the study. Forty-four healthy controls constituted the normative population. An optimized statistical mapping analysis was performed to compare each subject's GM Magnetization Transfer Ratio (MTR imaging maps with those of the whole group of controls. The statistical threshold of significant GM MTR decrease was determined as the maximum p value (p<0.05 FDR for which no significant cluster survived when comparing each control to the whole control population. Using this threshold, 51% of patients showed GM abnormalities compared to controls. Locally, 37% of patients presented abnormalities inside the limbic cortex, 34% in the temporal cortex, 32% in the deep grey matter, 30% in the cerebellum, 30% in the frontal cortex, 26% in the occipital cortex and 19% in the parietal cortex. Stepwise regression analysis evidenced significant association (p = 0.002 between EDSS and both GM pathology (p = 0.028 and T2 white matter lesions load (p = 0.019. In the present study, we evidenced that individual analysis of GM MTR map allowed demonstrating that GM pathology is highly heterogeneous across patients at the early stage of MS and partly underlies irreversible disability.

  16. Registration of multimodal brain images: some experimental results

    Chen, Hua-mei; Varshney, Pramod K.


    Joint histogram of two images is required to uniquely determine the mutual information between the two images. It has been pointed out that, under certain conditions, existing joint histogram estimation algorithms like partial volume interpolation (PVI) and linear interpolation may result in different types of artifact patterns in the MI based registration function by introducing spurious maxima. As a result, the artifacts may hamper the global optimization process and limit registration accuracy. In this paper we present an extensive study of interpolation-induced artifacts using simulated brain images and show that similar artifact patterns also exist when other intensity interpolation algorithms like cubic convolution interpolation and cubic B-spline interpolation are used. A new joint histogram estimation scheme named generalized partial volume estimation (GPVE) is proposed to eliminate the artifacts. A kernel function is involved in the proposed scheme and when the 1st order B-spline is chosen as the kernel function, it is equivalent to the PVI. A clinical brain image database furnished by Vanderbilt University is used to compare the accuracy of our algorithm with that of PVI. Our experimental results show that the use of higher order kernels can effectively remove the artifacts and, in cases when MI based registration result suffers from the artifacts, registration accuracy can be improved significantly.

  17. This image smells good: Effects of image information scent in search engine results pages

    Loumakis, F.; Stumpf, S.; Grayson, D


    Users are confronted with an overwhelming amount of web pages when they look for information on the Internet. Current search engines already aid the user in their information seeking tasks by providing textual results but adding images to results pages could further help the user in judging the relevance of a result. We investigated this problem from an Information Foraging perspective and we report on two empirical studies that focused on the information scent of images. Our results show tha...

  18. Interventional C-arm tomosynthesis for vascular imaging: initial results

    Langan, David A.; Claus, Bernhard E. H.; Al Assad, Omar; Trousset, Yves; Riddell, Cyril; Avignon, Gregoire; Solomon, Stephen B.; Lai, Hao; Wang, Xin


    As percutaneous endovascular procedures address more complex and broader disease states, there is an increasing need for intra-procedure 3D vascular imaging. In this paper, we investigate C-Arm 2-axis tomosynthesis ("Tomo") as an alternative to C-Arm Cone Beam Computed Tomography (CBCT) for workflow situations in which the CBCT acquisition may be inconvenient or prohibited. We report on our experience in performing tomosynthesis acquisitions with a digital angiographic imaging system (GE Healthcare Innova 4100 Angiographic Imaging System, Milwaukee, WI). During a tomo acquisition the detector and tube each orbit on a plane above and below the table respectively. The tomo orbit may be circular or elliptical, and the tomographic half-angle in our studies varied from approximately 16 to 28 degrees as a function of orbit period. The trajectory, geometric calibration, and gantry performance are presented. We overview a multi-resolution iterative reconstruction employing compressed sensing techniques to mitigate artifacts associated with incomplete data reconstructions. In this work, we focus on the reconstruction of small high contrast objects such as iodinated vasculature and interventional devices. We evaluate the overall performance of the acquisition and reconstruction through phantom acquisitions and a swine study. Both tomo and comparable CBCT acquisitions were performed during the swine study thereby enabling the use of CBCT as a reference in the evaluation of tomo vascular imaging. We close with a discussion of potential clinical applications for tomo, reflecting on the imaging and workflow results achieved.

  19. Application of Factor Analysis on the Financial Ratios of Indian Cement Industry and Validation of the Results by Cluster Analysis

    De, Anupam; Bandyopadhyay, Gautam; Chakraborty, B. N.


    Financial ratio analysis is an important and commonly used tool in analyzing financial health of a firm. Quite a large number of financial ratios, which can be categorized in different groups, are used for this analysis. However, to reduce number of ratios to be used for financial analysis and regrouping them into different groups on basis of empirical evidence, Factor Analysis technique is being used successfully by different researches during the last three decades. In this study Factor Analysis has been applied over audited financial data of Indian cement companies for a period of 10 years. The sample companies are listed on the Stock Exchange India (BSE and NSE). Factor Analysis, conducted over 44 variables (financial ratios) grouped in 7 categories, resulted in 11 underlying categories (factors). Each factor is named in an appropriate manner considering the factor loads and constituent variables (ratios). Representative ratios are identified for each such factor. To validate the results of Factor Analysis and to reach final conclusion regarding the representative ratios, Cluster Analysis had been performed.


    Duignan, M; Charles Nash, C; Timothy Punch, T


    A principal role of the DOE Savannah River Site is to safely dispose of a large volume of liquid nuclear waste held in many storage tanks. An in-tank ion exchange unit is being considered for cesium removal to accelerate waste processing. This unit is planned to have a relatively high bed height to diameter ratio (10:1). Complicating the design is the need to cool the ion exchange media; therefore, the ion exchange column will have a central cooling core making the flow path annular. To separate cesium from waste the media being considered is made of resorcinol formaldehyde resin deposited on spherical plastic beads and is a substitute for a previously tested resin made of crystalline silicotitanate. This spherical media not only has an advantage of being mechanically robust, but, unlike its predecessor, it is also reusable, that is, loaded cesium can be removed through elution and regeneration. Resin regeneration leads to more efficient operation and less spent resin waste, but its hydraulic performance in the planned ion exchange column was unknown. Moreover, the recycling process of this spherical resorcinol formaldehyde causes its volume to significantly shrink and swell. To determine the spherical media's hydraulic demand a linearly scaled column was designed and tested. The waste simulant used was prototypic of the wastes' viscosity and density. This paper discusses the hydraulic performance of the media that will be used to assist in the design of a full-scale unit.

  1. Magnetic resonance imaging urodynamics: technique development and preliminary results

    Gustavo Borghesi


    Full Text Available OBJECTIVES: In this preliminary study we report the development of the video urodynamic technique using magnetic resonance imaging (MRI. MATERIALS AND METHODS: We studied 6 women with genuine stress urinary incontinence, diagnosed by history and physical examination. Urodynamic examination was performed on multichannel equipment with the patient in the supine position. Coughing and Valsalva maneuvers were performed at volumes of 150, 250 and 350 mL. Simultaneously, MRI was carried out by using 1.5 T GE Signa CV/i high-speed scanner with real time fluoroscopic imaging possibilities. Fluoroscopic imaging was accomplished in the corresponding planes with T2-weighted single shot fast spin echo sequences at a speed of about 1 frame per second. Both studies were recorded and synchronized, resulting in a single video urodynamic examination. RESULTS: Dynamic MRI with cine-loop reconstruction of 1 image per second demonstrated the movement of all compartment of the relaxed pelvis during straining with the concomitant registration of abdominal and intravesical pressures. In 5 patients, urinary leakage was demonstrated during straining and the Valsalva leak point pressure (VLPP was determined as the vesical pressure at leak subtracted from baseline bladder pressure. Mean VLPP was 72.6 cm H2O (ranging from 43 to 122 cm H2O. CONCLUSIONS: The concept of MRI video urodynamics is feasible. In a clinical perspective, practical aspects represent a barrier to daily use and it should be recommended for research purposes.

  2. An alternative approach to estimate the W/C ratio of hardened concrete using image analysis

    Valcke, S.; Nijland, T.G.; Larbi, J.A.


    The water cement (w/c) ratio is a typical quality parameter for concrete. The NT Build 361 Nordtest method is a standard for estimating the w/c ratio in hardened concrete and is based on the relationship between the ilc ratio and the capillary porosity in the cement paste. The latter can be estimate

  3. Voxel-wise relationships between distribution volume ratio and cerebral blood flow: implications for analysis of β-amyloid images

    Sojkova, Jitka; Goh, Joshua; Bilgel, Murat; Landman, Bennett; Yang, Xue; Zhou, Yun; An, Yang; Beason-Held, Lori L.; Kraut, Michael A.; Wong, Dean F.; Resnick, Susan M.


    Quantification of β-amyloid (Aβ) in vivo is often accomplished using the distribution volume ratio (DVR), based on a simplified reference tissue model. We investigated the local relationships between DVR and cerebral blood flow (CBF), as well as relative blood flow (R1), in nondemented older adults. Methods Fifty-five nondemented participants (mean age 78.5 years) in the Baltimore Longitudinal Study of Aging underwent 15O-H2O PET CBF and dynamic 11C-PiB-PET. 15O-H2O PET images were normalized and smoothed using SPM. A simplified reference tissue model with linear regression and spatial constraints was used to generate parametric DVR images. The DVR images were regressed on CBF images on a voxel-by-voxel basis using robust Biological Parametric Mapping, adjusting for age and sex (FDR p=0.05, k=50). DVR images were also regressed on R1 images, a measure of the transport rate constant from vascular space to tissue. All analyses were performed in the entire sample, and in high and low tertiles of mean cortical DVR. Results Voxel-based analyses showed that increased DVR is associated with increased CBF in frontal, parietal, temporal, and occipital cortices. However, this association appears to spare regions that typically show early β-amyloid (Aβ) deposition. A more robust relationship between DVR and CBF was observed in the lowest tertile of DVR, i.e., negligible cortical Aβ load, compared to the highest tertile of cortical DVR and Aβ load. Spatial distributions of the DVR-CBF and DVR-R1 correlations showed similar patterns. No reliable negative voxel-wise relationships between DVR and CBF or R1 were observed. Conclusion Robust associations between DVR and CBF at negligible Aβ levels, together with similar spatial distributions of DVR-CBF and DVR-R1 correlations, suggest that regional distribution of DVR reflects blood flow and tracer influx rather than pattern of Aβ deposition in those with minimal Aβ load. DVR-CBF associations in individuals with higher DVR

  4. Breast imaging with the SoftVue imaging system: first results

    Duric, Neb; Littrup, Peter; Schmidt, Steven; Li, Cuiping; Roy, Olivier; Bey-Knight, Lisa; Janer, Roman; Kunz, Dave; Chen, Xiaoyang; Goll, Jeffrey; Wallen, Andrea; Zafar, Fouzaan; Allada, Veerendra; West, Erik; Jovanovic, Ivana; Li, Kuo; Greenway, William


    For women with dense breast tissue, who are at much higher risk for developing breast cancer, the performance of mammography is at its worst. Consequently, many early cancers go undetected when they are the most treatable. Improved cancer detection for women with dense breasts would decrease the proportion of breast cancers diagnosed at later stages, which would significantly lower the mortality rate. The emergence of whole breast ultrasound provides good performance for women with dense breast tissue, and may eliminate the current trade-off between the cost effectiveness of mammography and the imaging performance of more expensive systems such as magnetic resonance imaging. We report on the performance of SoftVue, a whole breast ultrasound imaging system, based on the principles of ultrasound tomography. SoftVue was developed by Delphinus Medical Technologies and builds on an early prototype developed at the Karmanos Cancer Institute. We present results from preliminary testing of the SoftVue system, performed both in the lab and in the clinic. These tests aimed to validate the expected improvements in image performance. Initial qualitative analyses showed major improvements in image quality, thereby validating the new imaging system design. Specifically, SoftVue's imaging performance was consistent across all breast density categories and had much better resolution and contrast. The implications of these results for clinical breast imaging are discussed and future work is described.

  5. JWST tunable filter imager: etalon prototype test results

    Touahri, D.; Cameron, P.; Evans, C.; Greenberg, E.; Rowlands, N.; Scott, A.; Doyon, R.; Beaulieu, M.; Djazovski, O.


    We present the prototyping results and laboratory characterization of a narrow band Fabry-Perot etalon flight model which is one of the wavelength selecting elements of the Tunable Filter Imager. The latter is a part of the Fine Guidance Sensor which represents the Canadian contribution to NASA's James Webb Space Telescope. The unique design of this etalon provides the JWST observatory with the ability to image at 30 Kelvin, a 2.2'x2.2' portion of its field of view in a narrow spectral bandwidth of R~100 at any wavelength ranging between 1.6 and 4.9 μm (with a gap in coverage between 2.5 and 3.2 μm). Extensive testing has resulted in better understanding of the thermal properties of the piezoelectric transducers used as an actuation system for the etalon gap tuning. Good throughput, spectral resolution and contrast have been demonstrated for the full wavelength range.

  6. Artery and vein diameter ratio measurement based on improvement of arteries and veins segmentation on retinal images.

    Hatanaka, Yuji; Tachiki, Hirokazu; Ogohara, Kazunori; Muramatsu, Chisako; Okumura, Susumu; Fujita, Hiroshi


    Retinal arteriolar narrowing is decided based on the artery and vein diameter ratio (AVR). Previous methods segmented blood vessels and classified arteries and veins by color pixels in the centerlines of blood vessels. AVR was definitively determined through measurement of artery and vein diameters. However, this approach was not sufficient for cases with close contact between the artery of interest and an imposing vein. Here, an algorithm for AVR measurement via new classification of arteries and veins is proposed. In this algorithm, additional steps for an accurate segmentation of arteries and veins, which were not identified using the previous method, have been added to better identify major veins in the red channel of a color image. To identify major arteries, a decision tree with three features was used. As a result, all major veins and 90.9% of major arteries were correctly identified, and the absolute mean error in AVRs was 0.12. The proposed method will require further testing with a greater number of images of arteriolar narrowing before clinical application.


    Ivana Bilić


    Full Text Available Human resources represent one of the most important companies’ resources responsible in creation of companies’ competitive advantage. In search for the most valuable resources, companies use different methods. Lately, one of the growing methods is electronic recruiting, not only as a recruitment tool, but also as a mean of external communication. Additionally, in the process of corporate communication, companies nowadays use the electronic corporate communication as the easiest, the cheapest and the simplest form of business communication. The aim of this paper is to investigate relationship between three groups of different criteria; including main characteristics of performed electronic recruiting, corporate communication and selected financial performances. Selected companies were ranked separately by each group of criteria by usage of multicriteria decision making method PROMETHEE II. The main idea is to research whether companies which are the highest performers by certain group of criteria obtain the similar results regarding other group of criteria or performing results.

  8. Assessment of survival of food-borne microorganisms in the food chain by fluorescence ratio imaging microscopy

    Siegumfeldt, Henrik; Arneborg, Nils


    Traditionally, many data on food–borne microorganisms are obtained as an average of a whole population, under the assumption that the individual cells are clonal and therefore identical. However, it is now acknowledged that there may be a large heterogeneity within an isogenic population, and con......- and sugar- and bacteriocin stress, as assessed by Fluorescence Ratio Imaging Microscopy....

  9. Assessing the Reliability of Geoelectric Imaging Results for Permafrost Investigations

    Marescot, L.; Loke, M.; Abbet, D.; Delaloye, R.; Hauck, C.; Hilbich, C.; Lambiel, C.; Reynard, E.


    The effects of global climate change on mountain permafrost are of increasing concern; warming thaws permafrost, thereby increasing the risk of slope instabilities. Consequently, knowledge of the extent and location of permafrost are important for construction and other geotechnical and land-management activities in mountainous areas. Geoelectric imaging is a useful tool for mapping and characterizing permafrost occurrences. To overcome the generally poor electrical contacts in the active layer, geoelectric surveys usually involve coupling the electrodes to the ground via sponges soaked in salt water. The data are processed and inverted in terms of resistivity models of the subsurface. To monitor the evolution of mountain permafrost, time-lapse geoelectric imaging may be employed. A challenging aspect in geoelectric imaging of permafrost is the very large resistivity contrast between frozen and unfrozen material. Such a contrast makes inversion and interpretation difficult. To assess whether features at depth are required by the data or are artifacts of the inversion process, the reliability of models needs to be evaluated. We use two different approaches to assess the reliability of resistivity images in permafrost investigations: (i) depth of investigation (DOI) and (ii) resolution matrix maps. To compute the DOI, two inversions of the same data set using quite different reference resistivity models are carried out. At locations where the resistivity is well constrained by the data, the inversions yield the same results. At other locations, the inversions yield different values that are controlled by the reference models. The resolution matrix, which is based on the sensitivity matrix calculated during the inversion, quantifies the degree to which each resistivity cell in the model can be resolved by the data. Application of these two approaches to field data acquired in the Swiss Alps and Jura Mountains suggests that it is very difficult to obtain dependable

  10. Surrogate/spent fuel sabotage aerosol ratio testing:phase 1 summary and results.

    Vigil, Manuel Gilbert; Sorenson, Ken Bryce; Lange, F. (Gesellschaft fur Anlagen- und reaktorsicherheit (GRS), Germany); Nolte, O. (Fraunhofer Institut fur Toxikologie und Experimentelle Medizin, Germany); Koch, W. (Fraunhofer Institut fur Toxikologie und Experimentelle Medizin, Germany); Dickey, Roy R.; Yoshimura, Richard Hiroyuki; Molecke, Martin Alan; Autrusson, Bruno (Institut de Radioprotection et de Surete Nucleaire (IRSN), France); Young, F. I. (U.S. Nuclear Regulatory Commission); Pretzsch, Gunter Guido (Gesellschaft fur Anlagen- und reaktorsicherheit (GRS), Germany)


    This multinational test program is quantifying the aerosol particulates produced when a high energy density device (HEDD) impacts surrogate material and actual spent fuel test rodlets. The experimental work, performed in four consecutive test phases, has been in progress for several years. The overall program provides needed data that are relevant to some sabotage scenarios in relation to spent fuel transport and storage casks, and associated risk assessments. This program also provides significant political benefits in international cooperation for nuclear security related evaluations. The spent fuel sabotage--aerosol test program is coordinated with the international Working Group for Sabotage Concerns of Transport and Storage Casks (WGSTSC), and supported by both the U.S. Department of Energy and Nuclear Regulatory Commission. This report summarizes the preliminary, Phase 1 work performed in 2001 and 2002 at Sandia National Laboratories and the Fraunhofer Institute, Germany, and documents the experimental results obtained, observations, and preliminary interpretations. Phase 1 testing included: performance quantifications of the HEDD devices; characterization of the HEDD or conical shaped charge (CSC) jet properties with multiple tests; refinement of the aerosol particle collection apparatus being used; and, CSC jet-aerosol tests using leaded glass plates and glass pellets, serving as representative brittle materials. Phase 1 testing was quite important for the design and performance of the following Phase 2 test program and test apparatus.

  11. Signal-to-noise ratio, contrast-to-noise ratio and pharmacokinetic modeling considerations in dynamic contrast-enhanced magnetic resonance imaging.

    Li, Xin; Huang, Wei; Rooney, William D


    With advances in magnetic resonance imaging (MRI) technology, dynamic contrast-enhanced (DCE)-MRI is approaching the capability to simultaneously deliver both high spatial and high temporal resolutions for clinical applications. However, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) considerations and their impacts regarding pharmacokinetic modeling of the time-course data continue to represent challenges in the design of DCE-MRI acquisitions. Given that many acquisition parameters can affect the nature of DCE-MRI data, minimizing tissue-specific data acquisition discrepancy (among sites and scanner models) is as important as synchronizing pharmacokinetic modeling approaches. For cancer-related DCE-MRI studies where rapid contrast reagent (CR) extravasation is expected, current DCE-MRI protocols often adopt a three-dimensional fast low-angle shot (FLASH) sequence to achieve spatial-temporal resolution requirements. Based on breast and prostate DCE-MRI data acquired with different FLASH sequence parameters, this paper elucidates a number of SNR and CNR considerations for acquisition optimization and pharmacokinetic modeling implications therein. Simulations based on region of interest data further indicate that the effects of intercompartmental water exchange often play an important role in DCE time-course data modeling, especially for protocols optimized for post-CR SNR.

  12. Experimental results and analysis of sparse microwave imaging from spaceborne radar raw data

    JIANG ChengLong; ZHANG BingChen; ZHANG Zhe; HONG Wen; WU YiRong


    Sparse microwave imaging is a novel radar framework aiming to bring revolutions to the microwave imaging according to the theory of sparse signal processing. As compressive sensing (CS) is introduced to synthetic aperture radar (SAR) imaging in recent years,the current SAR sparse imaging methods have shown their advantages over the traditional matched filtering methods.However,the requirement for these methods to process the compressed range data results in the increase of the hardware complexity.So the SAR sparse imaging method that directly uses the raw data is needed.This paper describes the method of SAR sparse imaging with raw data directly,presents the analysis of the signal-to-noise ratio (SNR) in the echo signal by combining the traditional radar equation with the compressive sensing theory,and provides the tests on 2-D simulated SAR data.The simulation results demonstrate the validity of the SNR analysis,and the good performance of the proposed method while a large percentage of the raw data is dropped. An experiment with RadarSat-1 raw data is also carried out to show the feasibility of processing the real SAR data via the method proposed in this paper.Our method is helpful for designing new SAR systems.

  13. Initial results from the fast imaging solar spectrograph (FISS)


    This collection of papers describes the instrument and initial results obtained from the Fast Imaging Solar Spectrograph (FISS),  one of the post-focus instruments of the 1.6 meter New Solar Telescope at the Big Bear Solar Observatory. The FISS primarily aims at investigating structures and dynamics of  chromospheric features. This instrument is a dual-band Echelle spectrograph optimized for the simultaneous recording of the H I 656.3 nm band and the Ca II 854.2 nm band. The imaging is done with the fast raster scan realized by the linear motion of a two-mirror scanner, and its quality is determined by the performance of the adaptive optics of the telescope.    These papers illustrate the capability of the early FISS observations in the study of chromospheric features. Since the imaging quality has been improved a lot with the advance of the adaptive optics, one can obtain much better data with the current FISS observations.        This volume is aimed at graduate students and researchers working in...

  14. First Results from the Solar Ultraviolet Imager on GOES-16

    Seaton, Daniel B.; Darnel, Jonathan; Hill, Steven M.; Edwards, Chris; Mathur, Dnyanesh; Sabolish, David; Sequin, Ralph; Miller Shaw, Margaret; Shing, Lawrence; Slater, Gregory L.; Gopal, Vasudevan


    The Solar Ultraviolet Imager, launched November 19, 2016, on the GOES-16 spacecraft, is the first in a line of four identical instruments that will image the Sun’s atmosphere in the extreme ultraviolet for the next 20 years. SUVI’s six passbands — 94, 131, 171, 195, 284, and 304 Å — provide images of the solar chromosphere and corona over a temperature range from about 50,000 K to 10 million K. SUVI’s primary mission is to support space weather forecasting operations at NOAA’s Space Weather Prediction Center, but its unique properties — most notably its relatively large large 53×53 arcmin field of view — offer several opportunities for new research. These unique opportunities include the both study of the large-scale structure of the solar corona and the process of magnetic reconnection that powers solar flares and eruptions. Here, we will present an overview the instrument and its capabilities, ways to access its data, and some highlights from its early results.

  15. Airborne test results for smart pushbroom imaging system with optoelectronic image correction

    Tchernykh, Valerij; Dyblenko, Serguei; Janschek, Klaus; Seifart, Klaus; Harnisch, Bernd


    Smart pushbroom imaging system (SMARTSCAN) solves the problem of image correction for satellite pushbroom cameras which are disturbed by satellite attitude instability effects. Satellite cameras with linear sensors are particularly sensitive to attitude errors, which cause considerable image distortions. A novel solution of distortions correction is presented, which is based on the real-time recording of the image motion in the focal plane of the satellite camera. This allows using such smart pushbroom cameras (multi-/hyperspectral) even on moderately stabilised satellites, e.g. small sat's, LEO comsat's. The SMARTSCAN concept uses in-situ measurements of the image motion with additional CCD-sensors in the focal plane and real-time image processing of these measurements by an onboard Joint Transform Optical Correlator. SMARTSCAN has been successfully demonstrated with breadboard models for the Optical Correlator and a Smart Pushbroom Camera at laboratory level (satellite motion simulator on base of a 5 DOF industrial robot) and by an airborne flight demonstration in July 2002. The paper describes briefly the principle of operation of the system and gives a description of the hardware model are provided. Detailed results of the airborne tests and performance analysis are given as well as detailed tests description.

  16. Assessment of lung development in isolated congenital diaphragmatic hernia using signal intensity ratios on fetal MR imaging.

    Balassy, Csilla; Kasprian, Gregor; Brugger, Peter C; Weber, Michael; Csapo, Bence; Herold, Christian; Prayer, Daniela


    To investigate developmental changes in the apparently unaffected contralateral lung by using signal intensity ratios (SIR) and lung volumes (LV), and to search for correlation with clinical outcome. Twenty-five fetuses (22-37 weeks' gestation) were examined. Lung/liver signal intensity ratios (LLSIR) were assessed on T1-weighted and T2-weighted sequences for both lungs, then together with LV compared with age-matched controls of 91 fetuses by using the U test. Differences in LLSIRs and lung volumes were correlated with neonatal outcomes. LLSIRs in fetuses with congenital diaphragmatic hernia (CDH) were significantly higher in both lungs on T1-weighted images and significantly lower on T2-weighted images, compared with normals (p < 0.05), increasing on T2-weighted imaging and decreasing on T1-weighted imaging during gestation. Total LV were significantly smaller in the CDH group than in controls (p < 0.05). No significant differences in LLSIR of the two lungs were found. Outcomes correlated significantly with total LV, but not with LLSIR. Changes in LLSIR seem to reflect developmental impairment in CDH; however, they provide no additional information in predicting outcome. LV remains the best indicator on fetal MR imaging of neonatal survival in isolated, left-sided CDH.

  17. Assessment of lung development in isolated congenital diaphragmatic hernia using signal intensity ratios on fetal MR imaging

    Balassy, Csilla; Kasprian, Gregor; Weber, Michael; Herold, Christian; Prayer, Daniela [Medical University of Vienna, Department of Radiology, Vienna (Austria); Brugger, Peter C. [Medical University of Vienna, Centre of Anatomy and Cell Biology, Vienna (Austria); Csapo, Bence [Medical University of Vienna, Department of Obstetrics and Gyneocology, Vienna (Austria)


    To investigate developmental changes in the apparently unaffected contralateral lung by using signal intensity ratios (SIR) and lung volumes (LV), and to search for correlation with clinical outcome. Twenty-five fetuses (22-37 weeks' gestation) were examined. Lung/liver signal intensity ratios (LLSIR) were assessed on T1-weighted and T2-weighted sequences for both lungs, then together with LV compared with age-matched controls of 91 fetuses by using the U test. Differences in LLSIRs and lung volumes were correlated with neonatal outcomes. LLSIRs in fetuses with congenital diaphragmatic hernia (CDH) were significantly higher in both lungs on T1-weighted images and significantly lower on T2-weighted images, compared with normals (p < 0.05), increasing on T2-weighted imaging and decreasing on T1-weighted imaging during gestation. Total LV were significantly smaller in the CDH group than in controls (p < 0.05). No significant differences in LLSIR of the two lungs were found. Outcomes correlated significantly with total LV, but not with LLSIR. Changes in LLSIR seem to reflect developmental impairment in CDH; however, they provide no additional information in predicting outcome. LV remains the best indicator on fetal MR imaging of neonatal survival in isolated, left-sided CDH. (orig.)

  18. A robust computational solution for automated quantification of a specific binding ratio based on [123i]fp-cit SPECT images.

    Oliveira, F P M; Borges Faria, D; Campos Costa, D; Tavares, J M R S


    The purpose of the current paper is to present a computational solution to accurately quantify a specific to a non-specific uptake ratio in [123I]fP-CIT single photon emission computed tomography (SPECT) images and simultaneously measure the spatial dimensions of the basal ganglia, also known as basal nuclei. A statistical analysis based on a reference dataset selected by the user is also automatically performed. The quantification of the specific to non-specific uptake ratio here is based on regions of interest defined after the registration of the image under study with a template image. The computational solution was tested on a dataset of 38 [123I]FP-CIT SPECT images: 28 images were from patients with Parkinson's disease and the remainder from normal patients, and the results of the automated quantification were compared to the ones obtained by three well-known semi-automated quantification methods. The results revealed a high correlation coefficient between the developed automated method and the three semi-automated methods used for comparison (r ≥0.975). The solution also showed good robustness against different positions of the patient, as an almost perfect agreement between the specific to non-specific uptake ratio was found (ICC=1.000). The mean processing time was around 6 seconds per study using a common notebook PC. The solution developed can be useful for clinicians to evaluate [123I]FP-CIT SPECT images due to its accuracy, robustness and speed. Also, the comparison between case studies and the follow-up of patients can be done more accurately and proficiently since the intra- and inter-observer variability of the semi-automated calculation does not exist in automated solutions. The dimensions of the basal ganglia and their automatic comparison with the values of the population selected as reference are also important for professionals in this area.

  19. Artifacts resulting from imaging in scattering media: a theoretical prediction.

    Rohrbach, Alexander


    Scattering of illumination light from a laser is a severe problem especially when imaging in thick media. Although this effect occurs in nearly every imaging process, it can be well perceived and analyzed in configurations where the optical axes for illumination and detection are perpendicular to each other. In this paper I present a theoretical perspective of how to extend the point-spread function arithmetic from ideal imaging to realistic imaging including ghost images. These ghost images are generated by scattered light and are low-correlated with the ideal image. Numerical simulations of the propagation of four different types of illumination beams through a cluster of spheres illustrate the effects of inhomogeneous object illumination. Clear differences between a conventional plane-wave illumination, a static light-sheet, and a laterally scanned Gaussian beam, but also relative to a scanned Bessel beam, can be observed.

  20. Inflow hemodynamics evaluated by using four-dimensional flow magnetic resonance imaging and the size ratio of unruptured cerebral aneurysms

    Futami, Kazuya [Matto-Ishikawa Central Hospital, Department of Neurosurgery, Hakusan, Ishikawa (Japan); Nambu, Iku; Kitabayashi, Tomohiro; Sano, Hiroki; Misaki, Kouichi; Uchiyama, Naoyuki; Nakada, Mitsutoshi [Kanazawa University School of Medicine, Department of Neurosurgery, Kanazawa, Ishikawa (Japan)


    Prediction of the rupture risk is critical for the identification of unruptured cerebral aneurysms (UCAs) eligible for invasive treatments. The size ratio (SR) is a strong morphological predictor for rupture. We investigated the relationship between the inflow hemodynamics evaluated on four-dimensional (4D) flow magnetic resonance (MR) imaging and the SR to identify specific characteristics related to UCA rupture. We evaluated the inflow jet patterns and inflow hemodynamic parameters of 70 UCAs on 4D flow MR imaging and compared them among 23 aneurysms with an SR ≥2.1 and 47 aneurysms with an SR ≤2.0. Based on the shape of inflow streamline bundles with a velocity ≥75% of the maximum flow velocity in the parent artery, the inflow jet patterns were classified as concentrated (C), diffuse (D), neck-limited (N), and unvisualized (U). The incidence of patterns C and N was significantly higher in aneurysms with an SR ≥2.1. The rate of pattern U was significantly higher in aneurysms with an SR ≤2.0. The maximum inflow rate and the inflow rate ratio were significantly higher in aneurysms with an SR ≥2.1. The SR affected the inflow jet pattern, the maximum inflow rate, and the inflow rate ratio of UCAs. In conjunction with the SR, inflow hemodynamic analysis using 4D flow MR imaging may contribute to the risk stratification for aneurysmal rupture. (orig.)

  1. Comprehensive analysis of proton range uncertainties related to stopping-power-ratio estimation using dual-energy CT imaging

    Li, B.; Lee, H. C.; Duan, X.; Shen, C.; Zhou, L.; Jia, X.; Yang, M.


    The dual-energy CT-based (DECT) approach holds promise in reducing the overall uncertainty in proton stopping-power-ratio (SPR) estimation as compared to the conventional stoichiometric calibration approach. The objective of this study was to analyze the factors contributing to uncertainty in SPR estimation using the DECT-based approach and to derive a comprehensive estimate of the range uncertainty associated with SPR estimation in treatment planning. Two state-of-the-art DECT-based methods were selected and implemented on a Siemens SOMATOM Force DECT scanner. The uncertainties were first divided into five independent categories. The uncertainty associated with each category was estimated for lung, soft and bone tissues separately. A single composite uncertainty estimate was eventually determined for three tumor sites (lung, prostate and head-and-neck) by weighting the relative proportion of each tissue group for that specific site. The uncertainties associated with the two selected DECT methods were found to be similar, therefore the following results applied to both methods. The overall uncertainty (1σ) in SPR estimation with the DECT-based approach was estimated to be 3.8%, 1.2% and 2.0% for lung, soft and bone tissues, respectively. The dominant factor contributing to uncertainty in the DECT approach was the imaging uncertainties, followed by the DECT modeling uncertainties. Our study showed that the DECT approach can reduce the overall range uncertainty to approximately 2.2% (2σ) in clinical scenarios, in contrast to the previously reported 1%.

  2. Quantitative analysis of melamine in milk powders using near-infrared hyperspectral imaging and band ratio

    Since 2008, the detection of the adulterant melamine (2,4,6-triamino-1,3,5-triazine) in food products has become the subject of research due to several food safety scares. Near-infrared (NIR) hyperspectral imaging offers great potential for food safety and quality research because it combines the fe...

  3. Diffuse Prior Monotonic Likelihood Ratio Test for Evaluation of Fused Image Quality Measures


    Program., vol. 47, pp. 425–439, May 1990. [31] T. Moon and W. C. Stirling , Mathematical Methods and Algorithms for Signal Processing. Upper Saddle...Conf., Big Sky , MT, Mar. 2006. [40] D.-O. Kim and R.-H. Park, “New image quality metric using the Harris response,” IEEE Signal Process. Lett., vol

  4. Autofocus imaging : Experimental results in an anisotropic austenitic weld

    Zhang, J.; Drinkwater, B.W.; Wilcox, P.D.; Hunter, A.J.


    The quality of an ultrasonic array image, especially for anisotropic material, depends on accurate information about acoustic properties. Inaccuracy of acoustic properties causes image degradation, e.g., blurring, errors in locating of reflectors and introduction of artifacts. In this paper, for an

  5. Autofocus imaging : Experimental results in an anisotropic austenitic weld

    Zhang, J.; Drinkwater, B.W.; Wilcox, P.D.; Hunter, A.J.


    The quality of an ultrasonic array image, especially for anisotropic material, depends on accurate information about acoustic properties. Inaccuracy of acoustic properties causes image degradation, e.g., blurring, errors in locating of reflectors and introduction of artifacts. In this paper, for an

  6. Autofocus imaging: Experimental results in an anisotropic austenitic weld

    Zhang, J.; Drinkwater, B. W.; Wilcox, P. D.; Hunter, A.


    The quality of an ultrasonic array image, especially for anisotropic material, depends on accurate information about acoustic properties. Inaccuracy of acoustic properties causes image degradation, e.g., blurring, errors in locating of reflectors and introduction of artifacts. In this paper, for an anisotropic austenitic steel weld, an autofocus imaging technique is presented. The array data from a series of beacons is captured and then used to statistically extract anisotropic weld properties by using a Monte-Carlo inversion approach. The beacon and imaging systems are realized using two separated arrays; one acts as a series of beacons and the other images these beacons. Key to the Monte-Carlo inversion scheme is a fast forward model of wave propagation in the anisotropic weld and this is based on the Dijkstra algorithm. Using this autofocus approach a measured weld map was extracted from an austenitic weld and used to reduce location errors, initially greater than 6mm, to less than 1mm.

  7. Initial results of finger imaging using Photoacoustic Computed Tomography

    van Es, Peter; Moens, Hein J Bernelot; Steenbergen, Wiendelt; Manohar, Srirang


    We present a photoacoustic computed tomography investigation on a healthy human finger, to image blood vessels with a focus on vascularity across the interphalangeal joints. The cross-sectional images were acquired using an imager specifically developed for this purpose. The images show rich detail of the digital blood vessels with diameters between 100 $\\mu$m and 1.5 mm in various orientations and at various depths. Different vascular layers in the skin including the subpapillary plexus could also be visualized. Acoustic reflections on the finger bone of photoacoustic signals from skin were visible in sequential slice images along the finger except at the location of the joint gaps. Not unexpectedly, the healthy synovial membrane at the joint gaps was not detected due to its small size and normal vascularization. Future research will concentrate on studying digits afflicted with rheumatoid arthritis to detect the inflamed synovium with its heightened vascularization, whose characteristics are potential marke...

  8. Diffusion-weighted imaging findings of adnexal torsion: Initial results

    Fujii, Shinya, E-mail: [Division of Radiology, Department of Pathophysiological and Therapeutic Science, Faculty of Medicine, Tottori University, 36-1 Nishi-cho, Yonago, Tottori 683-8504 (Japan); Kaneda, Sachi; Kakite, Suguru; Kanasaki, Yoshiko; Matsusue, Eiji [Division of Radiology, Department of Pathophysiological and Therapeutic Science, Faculty of Medicine, Tottori University, 36-1 Nishi-cho, Yonago, Tottori 683-8504 (Japan); Harada, Tasuku [Division of Reproductive-Perinatal Medicine and Gynecological Oncology, Department of Surgery, Faculty of Medicine, Tottori University, Yonago (Japan); Kaminou, Toshio; Ogawa, Toshihide [Division of Radiology, Department of Pathophysiological and Therapeutic Science, Faculty of Medicine, Tottori University, 36-1 Nishi-cho, Yonago, Tottori 683-8504 (Japan)


    Our purpose is to clarify the diffusion-weighted (DW) imaging findings of adnexal torsion. We retrospectively analyzed the DW imaging findings in 11 consecutive patients with surgical confirmation of adnexal torsion. We assessed signal intensity of the adnexal mass and fallopian tube thickening, and the location of abnormal signal intensity within the adnexal mass. On DW imaging, thickening of the fallopian tube was apparent as abnormal signal intensity in 8 of 11 patients. Abnormal signal intensity was inhomogeneous in 7 of 8 patients. Abnormal signal intensity on DW imaging was observed in 10 of 11 adnexal masses, and in the walls of 7 out of 8 adnexal cystic lesions. In adnexal torsion, DW imaging showed abnormal signal intensity in the thickened fallopian tube and in the wall of cystic ovarian lesions. These findings would be feasible to diagnose adnexal torsion.

  9. Lessons and key results from 30 years of imaging spectroscopy

    Green, Robert O.


    Spectroscopy was first used in 1814 by Joseph von Fraunhofer as a scientific method for discovery, and to develop and test scientific hypotheses. From this beginning, spectroscopy evolved to a broadly used analytical tool for both science and applications. In the 1970's, technology began to enable a class of instruments that measure spectra for every point in an image. The first airborne imaging spectrometer developed at the Jet Propulsion Laboratory flew in 1982. Subsequently, a wide range of imaging spectrometers have been developed, many at the Jet Propulsion Laboratory, for airborne and space platforms and they have participated in NASA mission throughout the solar system. A key lesson over this time period has been the broad applicability of imaging spectrometers to pursue a range of science and application objectives wherever there is relevant signal in the spectral range from the ultra violet to the thermal infrared. As with all optical imaging instruments, imaging spectrometers have spectral, radiometric and spatial characteristics and related requirements. Of these, uniformity, radiometric precision, and calibration have been identified as critically important for the science and application utility of imaging spectrometer instruments. These key requirements are enabling for the most advanced imaging spectrometer algorithms that retrieve parameters with units and quantifiable uncertainties. The current trend in imaging spectrometer instrumentation is for broader spectral coverage and wider swath while improving uniformity, precision, and calibration. A companion emphasis is for lower mass, power and volume, with instruments taking advantage of the latest detector, optical, electronics and computational technologies. The number of imaging spectrometers in use is increasing every year and this trend is on track to continue.

  10. Search for novel contrast materials in dual-energy x-ray breast imaging using theoretical modeling of contrast-to-noise ratio.

    Karunamuni, R; Maidment, A D A


    Contrast-enhanced (CE) dual-energy (DE) x-ray breast imaging uses a low- and high-energy x-ray spectral pair to eliminate soft-tissue signal variation and thereby increase the detectability of exogenous imaging agents. Currently, CEDE breast imaging is performed with iodinated contrast agents. These compounds are limited by several deficiencies, including rapid clearance and poor tumor targeting ability. The purpose of this work is to identify novel contrast materials whose contrast-to-noise ratio (CNR) is comparable or superior to that of iodine in the mammographic energy range. A monoenergetic DE subtraction framework was developed to calculate the DE signal intensity resulting from the logarithmic subtraction of the low- and high-energy signal intensities. A weighting factor is calculated to remove the dependence of the DE signal on the glandularity of the breast tissue. Using the DE signal intensity and weighting factor, the CNR for materials with atomic numbers (Z) ranging from 1 to 79 are computed for energy pairs between 10 and 50 keV. A group of materials with atomic numbers ranging from 42 to 63 were identified to exhibit the highest levels of CNR in the mammographic energy range. Several of these materials have been formulated as nanoparticles for various applications but none, apart from iodine, have been investigated as CEDE breast imaging agents. Within this group of materials, the necessary dose fraction to the LE image decreases as the atomic number increases. By reducing the dose to the LE image, the DE subtraction technique will not provide an anatomical image of sufficient quality to accompany the contrast information. Therefore, materials with Z from 42 to 52 provide nearly optimal values of CNR with energy pairs and dose fractions that provide good anatomical images. This work is intended to inspire further research into new materials for optimized CEDE breast functional imaging.

  11. Imaging results and TOF studies with axial PET detectors

    Joram, Christian


    We have developed a fully operational PET demonstrator setup which allows true 3D reconstruction of the 511 keV photons and therefore leads to practically parallax free images. The AX-PET concept is based on thin 100 mm long scintillation crystals (LYSO), axially oriented and arranged in layers around the held of view. Layers of wavelength shifting plastic strips mounted in between the crystal layers give the axial coordinate. Both crystals and WLS strips are individually read out by G-APD (SiPM) photodetectors. The Fully scalable concept overcomes the dilemma of sensitivity versus spatial resolution which is inherent to classical PET designs. A demonstrator set-up based on two axial modules was exhaustively characterized using point-like sources, phantoms filled with radiotracer and finally rats and a mouse. The results entirely meet the performance expectations ( <2 mm FWHM in all three coordinates over the complete held of view) and also demonstrated the ability to include Compton interactions (inter-cr...

  12. Measurement of Autolysosomal pH by Dual-Wavelength Ratio Imaging.

    Saric, A; Grinstein, S; Freeman, S A


    Cellular components sequestered by autophagosomes during macroautophagy must be degraded and their components recycled in order to maintain homeostasis. To this end cells orchestrate the fusion of autophagosomes with lysosomes, degradative organelles that are rich in hydrolases. Most of the lysosomal enzymes function optimally at low pH, and products of macromolecular catabolism are cotransported with protons across the autolysosomal membrane. These functions are facilitated by the ability of lysosomes to pump protons inward, acidifying their lumen. Clearly, proper homeostasis of the luminal pH is crucial for autolysosomal function. We describe a method for the measurement of the absolute pH of individual autolysosomes in live cells. This technique involves measurement of the fluorescence of a pH-sensitive probe initially delivered to lysosomes and subsequently determined to have reached autolysosomes. By measuring the fluorescence at two separate wavelengths and calculating their ratio, potential artifacts introduced by photobleaching or by changes in autolysosome size, shape, or positioning are minimized. Combining such ratio determinations with an in situ calibration procedure enables absolute measurements of pH, which are superior to the qualitative estimates obtained with fluorescent weak bases such as LysoTracker.

  13. Real time magma transport imaging and earthquake localization using seismic amplitude ratio analysis

    Taisne, B.; Brenguier, F.; Nercessian, A.; Beauducel, F.; Smith, P. J.


    Seismic amplitude ratio analysis (SARA) has been used successfully to track the sub-surface migration of magma prior to an eruption at Piton de la Fournaise volcano, La Réunion. The methodology is based on the temporal analysis of the seismic amplitude ratio between different pairs of stations, along with a model of seismic wave attenuation. This method has already highlighted the complexity of magma migration in the shallower part of the volcanic edifice during a seismic crisis using continuous records. We will see that this method can also be applied to the localization of individual earthquakes triggered by monitoring systems, prior to human intervention such as phase picking. As examples, the analysis is performed on two kinds of seismic events observed at Soufrière Hills Volcano, Montserrat during the last 15 years, namely: Hybrids events and Volcano-Tectonic earthquakes. Finally, we present the implementation of a fully automatic SARA method for monitoring of Piton de la Fournaise volcano using continuous data in real-time.

  14. Nuclear Breast Imaging: Clinical Results and Future Directions.

    Berg, Wendie A


    Interest in nuclear breast imaging is increasing because of technical improvements in dedicated devices that allow the use of relatively low doses of radiotracers with high sensitivity for even small breast cancers. For women with newly diagnosed cancer, primary chemotherapy is often recommended, and improved methods of assessing treatment response are of interest. With widespread breast density notification, functional rather than anatomic methods of screening are of increasing interest as well. For a cancer imaging technology to be adopted, several criteria must be met that will be discussed: evidence of clinical benefit with minimal harm, standardized interpretive criteria, direct biopsy guidance, and acceptable cost-effectiveness.

  15. Results of an Advanced Fan Stage Operating Over a Wide Range of Speed and Bypass Ratio. Part 1; Fan Stage Design and Experimental Results

    Suder, Kenneth L.; Prahst, Patricia S.; Thorp, Scott A.


    NASA s Fundamental Aeronautics Program is investigating turbine-based combined cycle (TBCC) propulsion systems for access to space because it provides the potential for aircraft-like, space-launch operations that may significantly reduce launch costs and improve safety. To this end, National Aeronautics and Space Administration (NASA) and General Electric (GE) teamed to design a Mach 4 variable cycle turbofan/ramjet engine for access to space. To enable the wide operating range of a Mach 4+ variable cycle turbofan ramjet required the development of a unique fan stage design capable of multi-point operation to accommodate variations in bypass ratio (10 ), fan speed (7 ), inlet mass flow (3.5 ), inlet pressure (8 ), and inlet temperature (3 ). In this paper, NASA has set out to characterize a TBCC engine fan stage aerodynamic performance and stability limits over a wide operating range including power-on and hypersonic-unique "windmill" operation. Herein, we will present the fan stage design, and the experimental test results of the fan stage operating from 15 to 100 percent corrected design speed. Whereas, in the companion paper, we will provide an assessment of NASA s APNASA code s ability to predict the fan stage performance and operability over a wide range of speed and bypass ratio.

  16. Influence of lesion ratio on diagnostic performance of in-phase/opposed-phase imaging and apparent diffusion coefficient for differentiating acute benign vertebral fractures and metastases

    LIN Fan; LEI Yi; LI Yang-bin


    Background The usefulness of in-phase/opposed-phase imaging and diffusion weighted imaging (DWI) in differentiating benign and neoplastic vertebral fractures has been described. In this study, we aimed to evaluate the influence of the severity of vertebral damage on the diagnostic performance of these two technologies.Methods Totally 59 patients with 68 acute benign vertebral fractures and 43 patients with 79 vertebral metastases were included in this study. The MR protocol included DWls and sagittal in-phase/opposed-phase gradient recalled sequence.The severity of vertebral damage was expressed by lesion ratio (LR, the ratio of lesion area to vertebral area on the slices of largest abnormal signal area in the T1-weighted sequence). Quantitative (signal intensity ratio (SIR) defined as signal intensity (SI) on opposed-phase gradient recalled echo (GRE) images divided by SI on in-phase; apparent diffusion coefficient (ADC) value derived from DWI analysis was performed, the relationships between LR and the measurements of these two technologies were analyzed using linear regression. The covariate-specific receiver operating characteristic (ROC) curves were also fitted to evaluate the influence of LR on the diagnostic performance of ADC and SIR. Results The difference in both SIR and ADC for vertebral metastasis and acute benign vertebral fractures was significant (P 0.05). More severe cases were associated with increased AUC for SIR.Conclusions LR is capable of affecting the diagnostic performances of chemical shift imaging. Thus, when applying these tests to make diagnoses on vertebral fractures, the severity of the vertebral damage should be taken into account.The covariate-specific ROC model is recommended because it substantially improves the ability to avoid bias when evaluating tests.

  17. Relationship between the Carotid Plaque T1 Relaxation Time and the Plaque-to-Muscle Signal Intensity Ratio on Black-Blood Magnetic Resonance Imaging Scans.

    Eto, Ayumu; Kinoshita, Yoshimasa; Matsumoto, Yoshihisa; Kiyomi, Fumiaki; Iko, Minoru; Nii, Kouhei; Tsutsumi, Masanori; Sakamoto, Kimiya; Aikawa, Hiroshi; Kazekawa, Kiyoshi


    Black-blood magnetic resonance imaging (BB-MRI) is useful for the characterization and assessment of carotid artery plaques. The plaque-to-muscle signal intensity (SI) ratio (plaque/muscle ratio [PMR]) is used widely to evaluate plaques. However, the correlation between the PMR and the T1 relaxation time needs to be determined. We measured the T1 relaxation time of carotid plaques using T1 mapping and compared the results with the PMR on BB-MRI scans. Between April 2014 and July 2015, 20 patients with carotid artery stenosis were treated by carotid artery stenting. All patients underwent preoperative magnetic resonance plaque imaging. The ratio of the plaque SI to the sternocleidomastoid muscle was calculated on T1-weighted BB-MRI scans. T1 mapping was performed in the region where the vessel was narrowest using the inversion recovery technique. The T1 relaxation time was recorded to determine whether there was a correlation with the PMR. The plaque T1 value was 577.3 ± 143.2 milliseconds; the PMR value obtained on BB-MRI scans was 1.23 ± .27. There was a statistically significant decrease in the T1 value as the PMR increased (P relaxation time was well correlated with the PMR on BB-MRI scans, the evaluation of vulnerable plaques using the PMR was reliable and convenient. Copyright © 2016 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  18. Nonlinear Imaging of Microbubble Contrast Agent Using the Volterra Filter: In Vivo Results.

    Du, Juan; Liu, Dalong; Ebbini, Emad S


    A nonlinear filtering approach to imaging the dynamics of microbubble ultrasound contrast agents (UCAs) in microvessels is presented. The approach is based on the adaptive third-order Volterra filter (TVF), which separates the linear, quadratic, and cubic components from beamformed pulse-echo ultrasound data. The TVF captures polynomial nonlinearities utilizing the full spectral components of the echo data and not from prespecified bands, e.g., second or third harmonics. This allows for imaging using broadband pulse transmission to preserve the axial resolution and the SNR. In this paper, we present the results from imaging the UCA activity in a 200- [Formula: see text] cellulose tube embedded in a tissue-mimicking phantom using a linear array diagnostic probe. The contrast enhancement was quantified by computing the contrast-to-tissue ratio (CTR) for the different imaging components, i.e., B-mode, pulse inversion (PI), and the TVF components. The temporal mean and standard deviation of the CTR values were computed for all frames in a given data set. Quadratic and cubic images, referred to as QB-mode and CB-mode, produced higher mean CTR values than B-mode, which showed improved sensitivity. Compared with PI, they produced similar or higher mean CTR values with greater spatial specificity. We also report in vivo results from imaging UCA activity in an implanted LNCaP tumor with heterogeneous perfusion. The temporal means and standard deviations of the echogenicity were evaluated in small regions with different perfusion levels in the presence and absence of UCA. The in vivo measurements behaved consistently with the corresponding calculations obtained under microflow conditions in vitro. Specifically, the nonlinear VF components produced larger increases in the temporal mean and standard deviation values compared with B-mode in regions with low to relatively high perfusion. These results showed that polynomial filters such as the TVF can provide an important tool

  19. Initial results of a positron tomograph for prostate imaging

    Huber, J.S.; Choong, W.S.; Moses, W.W.; Qi, J.; Hu, J.; Wang,G.C.; Wilson, D.; Oh, S.; Huesman, R.H.; Derenzo, S.E.; Budinger, T.F.


    We present the status and initial images of a positrontomograph for prostate imaging that centers a patient between a pair ofexternal curved detector banks (ellipse: 45 cm minor, 70 cm major axis).The distance between detector banks adjusts to allow patient access andto position the detectors as closely as possible for maximum sensitivitywith patients of various sizes. Each bank is composed of two axial rowsof 20 CTI PET Systems HR+ block detectors for a total of 80 modules inthe camera. Compared to an ECAT HR PET system operating in 3D mode, ourcamera uses about one-quarter the number of detectors and hasapproximately the same sensitivity for a central point source, becauseour detectors are close to the patient. The individual detectors areangled in the plane to point towards the prostate to minimize resolutiondegradation in that region. The detectors are read out by modified CTIdata acquisition electronics. We have completed construction of thegantry and electronics, have developed detector calibration and dataacquisition software, and are taking coincidence data. We demonstratethat we can clearly visualize a "prostate" in a simple phantom.Reconstructed images of two phantoms are shown.

  20. Statistical approach of measurement of signal to noise ratio in according to change pulse sequence on brain MRI meningioma and cyst images

    Lee, Eul Kyu [Inje Paik University Hospital Jeo-dong, Seoul (Korea, Republic of); Choi, Kwan Woo [Asan Medical Center, Seoul (Korea, Republic of); Jeong, Hoi Woun [The Baekseok Culture University, Cheonan (Korea, Republic of); Jang, Seo Goo [The Soonchunhyang University, Asan (Korea, Republic of); Kim, Ki Won [Kyung Hee University Hospital at Gang-dong, Seoul (Korea, Republic of); Son, Soon Yong [The Wonkwang Health Science University, Iksan (Korea, Republic of); Min, Jung Whan; Son, Jin Hyun [The Shingu University, Sungnam (Korea, Republic of)


    The purpose of this study was to needed basis of measure MRI CAD development for signal to noise ratio (SNR) by pulse sequence analysis from region of interest (ROI) in brain magnetic resonance imaging (MRI) contrast. We examined images of brain MRI contrast enhancement of 117 patients, from January 2005 to December 2015 in a University-affiliated hospital, Seoul, Korea. Diagnosed as one of two brain diseases such as meningioma and cysts SNR for each patient's image of brain MRI were calculated by using Image J. Differences of SNR among two brain diseases were tested by SPSS Statistics21 ANOVA test for there was statistical significance (p < 0.05). We have analysis socio-demographical variables, SNR according to sequence disease, 95% confidence according to SNR of sequence and difference in a mean of SNR. Meningioma results, with the quality of distributions in the order of T1CE, T2 and T1, FLAIR. Cysts results, with the quality of distributions in the order of T2 and T1, T1CE and FLAIR. SNR of MRI sequences of the brain would be useful to classify disease. Therefore, this study will contribute to evaluate brain diseases, and be a fundamental to enhancing the accuracy of CAD development.

  1. LOFAR: Early imaging results from commissioning for Cygnus A

    McKean, John; van Weeren, Reinout J; Batejat, Fabien; Birzan, Laura; Bonafede, Annalisa; Conway, John; De Gasperin, Francesco; Ferrari, Chiara; Heald, George; Jackson, Neal; Macario, Giulia; Orrù, Emanuela; Pizzo, Roberto; Rafferty, David; Rottgering, Huub; Shulevski, Aleksandar; Tasse, Cyril; van der Tol, Sebastiaan; van Bemmel, Ilse; van Diepen, Ger; van Zwieten, Joris E


    The Low Frequency Array (LOFAR) will operate between 10 and 250 MHz, and will observe the low frequency Universe to an unprecedented sensitivity and angular resolution. The construction and commissioning of LOFAR is well underway, with over 27 of the Dutch stations and five International stations routinely performing both single-station and interferometric observations over the frequency range that LOFAR is anticipated to operate at. Here, we summarize the capabilities of LOFAR and report on some of the early commissioning imaging of Cygnus A.

  2. Results from PIXON-Processed HRC Images of Pluto

    Young, E. F.; Buie, M. W.; Young, L. A.


    We examine the 384 dithered images of Pluto and Charon taken with the Hubble Space Telescope's High Resolution Camera (HRC) under program GO-9391. We have deconvolved the individual images with synthetic point spread functions (PSF) generated with TinyTim v6.3 using PIXON processing (Puetter and Yahil 1999). We reconstruct a surface albedo map of Pluto using a backprojection algorithm. At present, this algorithm does not include Hapke phase function or backscattering parameters. We compare this albedo map to earlier maps based on HST and mutual event observations (e.g., Stern et al. 1997, Young et al. 2001), looking for changes in albedo distribution and B-V color distribution. Pluto's volatile surface ices are closely tied to its atmospheric column abundance, which has doubled in the interval between 1989 and 2002 (Sicardy et al. 2003, Elliot et al. 2003). A slight rise (1.5 K) in the temperature of nitrogen ice would support the thicker atmosphere. We examine the albedo distribution in the context of Pluto's changing atmosphere. Finally, a side effect of the PIXON processing is that we are better able to search for additional satellites in the Pluto-Charon system. We find no satellites within a 12 arcsec radius of Pluto brighter than a 5-sigma upper limit of B=25.9. In between Pluto and Charon this upper limit is degraded to B=22.8 within one Rp of Pluto's surface, improving to B=25.1 at 10 Rp (Charon's semimajor axis). This research was supported by a grant from NASA's Planetary Astronomy Program (NAG5-12516) and STScI grant GO-9391. Elliot, J.L., and 28 co-authors (2003), ``The recent expansion of Pluto's atmosphere," Nature 424, 165-168. R. C. Puetter and A. Yahil (1999), ``The Pixon Method of Image Reconstruction" in Astronomical Data Analysis Software and Systems VIII, D. M. Mehringer, R. L. Plante & D. A. Roberts, eds., ASP Conference Series, 172, pp. 307-316. Sicardy, B. and 40 co-authors (2003), ``Large changes in Pluto's atmosphere as revealed by recent

  3. New microangiography system development providing improved small vessel imaging, increased contrast-to-noise ratios, and multiview 3D reconstructions

    Kuhls, Andrew T.; Patel, Vikas; Ionita, Ciprian; Noël, Peter B.; Walczak, Alan M.; Rangwala, Hussain S.; Hoffmann, Kenneth R.; Rudin, Stephen


    A new microangiographic system (MA) integrated into a c-arm gantry has been developed allowing precise placement of a MA at the exact same angle as the standard x-ray image intensifier (II) with unchanged source and object position. The MA can also be arbitrarily moved about the object and easily moved into the field of view (FOV) in front of the lower resolution II when higher resolution angiographic sequences are needed. The benefits of this new system are illustrated in a neurovascular study, where a rabbit is injected with contrast media for varying oblique angles. Digital subtraction angiographic (DSA) images were obtained and compared using both the MA and II detectors for the same projection view. Vessels imaged with the MA appear sharper with smaller vessels visualized. Visualization of ~100 μm vessels was possible with the MA whereas not with the II. Further, the MA could better resolve vessel overlap. Contrast to noise ratios (CNR) were calculated for vessels of varying sizes for the MA versus the II and were found to be similar for large vessels, approximately double for medium vessels, and infinitely better for the smallest vessels. In addition, a 3D reconstruction of selected vessel segments was performed, using multiple (three) projections at oblique angles, for each detector. This new MA/II integrated system should lead to improved diagnosis and image guidance of neurovascular interventions by enabling initial guidance with the low resolution large FOV II combined with use of the high resolution MA during critical parts of diagnostic and interventional procedures.

  4. Importance of Reference Muscle Selection in Quantitative Signal Intensity Analysis of T2-Weighted Images of Myocardial Edema Using a T2 Ratio Method

    Iacopo Carbone


    Full Text Available Objectives. The purpose of our study was to identify the suitability of various skeletal muscles as reference regions for calculating the T2 SI ratio for a semiautomated quantification of the extent of myocardial edema with T2-weighted images. Methods. Thirty-four patients with acute myocardial infarction (MI were enrolled. The extent of myocardial edema was determined by T2 SI ratio map, using 4 different muscles as reference: major and minor pectoralis, serratus anterior, teres minor-infraspinatus, and subscapularis. The size of myocardial edema as visually quantified was used as the standard of truth. The control group consisted of 15 patients with chronic MI. Intra- and interobserver variability were assessed. Results. Due to poor image quality four patients were excluded from the analysis. In acute MI patients, serratus anterior muscle showed the strongest correlation with the visual analysis (r=0.799; P<0.001 and low inter- and intraobserver variability, while the other muscles resulted in a significant interobserver variability. In contrast, the use of other muscles as a reference led to overestimating edema size. Conclusions. In acute MI patients, serratus anterior resulted to be the most reliable and reproducible muscle for measuring the extent of myocardial edema.

  5. Diagnostic value of transmural perfusion ratio derived from dynamic CT-based myocardial perfusion imaging for the detection of haemodynamically relevant coronary artery stenosis

    A. Coenen (Adriaan); M. Lubbers (Marisa); A. Kurata (Akira); A.K. Kono (Atsushi K.); A. Dedic (Admir); R.G. Chelu (Raluca Gabriela); M.L. Dijkshoorn (Marcel); Rossi, A. (Alexia); R.J.M. van Geuns (Robert Jan); K. Nieman (Koen)


    textabstractObjectives: To investigate the additional value of transmural perfusion ratio (TPR) in dynamic CT myocardial perfusion imaging for detection of haemodynamically significant coronary artery disease compared with fractional flow reserve (FFR). Methods: Subjects with suspected or known coro

  6. The harmonic ratio of trunk acceleration predicts falling among older people: results of a 1-year prospective study

    Doi Takehiko


    Full Text Available Abstract Background Gait variables derived from trunk accelerometry may predict the risk of falls; however, their associations with falls are not fully understood. The purpose of the study was to determine which gait variables derived from upper and lower trunk accelerometry are associated with the incidence of falls, and to compare the discriminative ability of gait variables and physical performance. Methods This study was a 1-year prospective study. Older people (n = 73 walked normally while wearing accelerometers attached to the upper and lower trunk. Participants were classified as fallers (n = 16 or non-fallers (n = 57 based on the incidence of falls over 1 year. The harmonic ratio (HR of the upper and lower trunk was measured. Physical performance was measured in five chair stands and in the timed up and go test. Results The HR of the upper and lower trunk were consistently lower in fallers than non-fallers (P P Conclusions HR derived from upper trunk accelerometry may predict the risk of falls, independently of physical performance. The discriminative ability of HR for the risk of falls may have some validity, and further studies are needed to confirm the clinical relevance of trunk HR.

  7. Prevalence and correlates of increased lung/heart ratio of thallium-201 during dipyridamole stress imaging for suspected coronary artery disease

    Villanueva, F.S.; Kaul, S.; Smith, W.H.; Watson, D.D.; Varma, S.K.; Beller, G.A. (Univ. of Virginia School of Medicine, Charlottesville (USA))


    There is little information concerning the prevalence and clinical correlates of increased pulmonary thallium-201 uptake during dipyridamole thallium-201 stress imaging. Accordingly, the clinical characteristics and quantitative thallium-201 findings were correlated with quantitative lung/heart thallium-201 ratio in 87 patients undergoing dipyridamole thallium-201 stress testing. Nineteen patients (22%) had an elevated ratio (greater than 0.51). These patients were more likely to have had an infarction, to be taking beta blockers, and have a lower rate-pressure product after dipyridamole administration than those with a normal ratio (p less than 0.03). An elevated ratio was associated with a greater likelihood of initial, redistribution and persistent defects, as well as left ventricular cavity dilatation on thallium-201 imaging (p less than 0.05). In addition, the number of myocardial segments demonstrating initial, redistribution and persistent defects was also greater in patients with increased ratios (p less than 0.03). Multivariate analysis demonstrated that the presence of redistribution and left ventricular cavity dilatation were the most significant correlates of lung/heart thallium-201 ratio. It is concluded that the prevalence of increased lung/heart thallium-201 ratio with dipyridamole thallium-201 stress imaging is similar to that seen with exercise stress imaging. As with exercise thallium-201 imaging, increased pulmonary thallium-201 uptake may be a marker of functionally more significant coronary artery disease.

  8. Preliminary results of acoustic radiation force impulses (ARFI) ultrasound imaging of solid suspicious breast lesions

    Lei Ye; Liping Wang; Yuan Huang; Youbin Deng


    Objective: The aim of our study was to make the qualitative and quantitative analysis to breast lesions usingacoustic radiation force impulses (ARFI), and assess the diagnostic value of ARFI for differentiation between benign andmalignant solid breast masses, meanwhile evaluate the influences of ARFI with breast imaging reporting and data system(BI-RADS) of suspicious masses. Methods: Seventy-five women with 86 breast lesions underwent conventional breast ultrasoundexamination. Then B-mode BI-RADS features and assessments were recorded and standard breast US supplementedby ARFI elastographic examination were repeated. The data were recorded and analyzed as following: area ratio of breastlesion, the shear-wave velocity, the ratio of the shear-wave velocity between lesions and surrounding normal tissues, andaccording to the elastographic data reconsidered the BI-RADS category, all the results have been correlated with pathologicalresults and make statistical evaluations of ARFI for differentiation between benign and malignant solid breast masses.Meantime our study has correlated the adjusted BI-RADS category of suspicious breast lesions with the pathological resultsand made assessment. Results: Thirty-eight patients were malignant breast carcinoma (31 invasive ductal carcinoma, 5intraductal carcinoma in situ, 2 medullary carcinoma, 2 invasive lobular carcinoma), 48 patients were benign breast lesions(23 fibroadenoma, 12 benign nodular hyperplasia, 5 phyllodes tumor, 6 adenosis, 2 intraductal papilloma). Underwent conventionalbreast ultrasound exam, 42 cases were BI-RADS category 3, 23 cases were BI-RADS category 4. When addingelastographic data, 46 cases were BI-RADS category 3 and 20 cases were BI-RADS category 4. Compared with pathologicalresults showed for both the specificity of BIRADS features and the area under ROC curve has risen. Virtual touch tissue imaging(VTI) and virtual touch tissue quantification (VTQ) data showed the area ratio (AR) between

  9. Results from laboratory tests of the two-dimensional Time-Encoded Imaging System.

    Marleau, Peter; Brennan, James S.; Brubaker, Erik; Gerling, Mark D; Le Galloudec, Nathalie Joelle


    A series of laboratory experiments were undertaken to demonstrate the feasibility of two dimensional time-encoded imaging. A prototype two-dimensional time encoded imaging system was designed and constructed. Results from imaging measurements of single and multiple point sources as well as extended source distributions are presented. Time encoded imaging has proven to be a simple method for achieving high resolution two-dimensional imaging with potential to be used in future arms control and treaty verification applications.

  10. Diagnostic usefulness of the oedema-infarct ratio to differentiate acute from chronic myocardial damage using magnetic resonance imaging

    Yamada, Kiyoyasu; Suzuki, Susumu; Kinoshita, Kousuke; Yokouchi, Kazuhiko; Iwata, Hirokazu; Sawada, Ken [Gifu Social Insurance Hospital, Department of Cardiology, Gifu (Japan); Isobe, Satoshi; Ohshima, Satoru; Murohara, Toyoaki [Nagoya University Graduate School of Medicine, Department of Cardiology, Nagoya (Japan); Hirai, Makoto [Nagoya University School of Health Sciences, Department of Nursing, Nagoya (Japan)


    To differentiate acute from chronic damage to the myocardium in patients with myocardial infarction (MI) using DE and T2w MR. Short-axis T2w and DE MR images were acquired twice after the onset of MI in 36 patients who successfully underwent emergency coronary revascularisation. The areas of infarct and oedema were measured. The oedema-infarct ratio (O/I) of the left ventricular area was calculated by dividing the oedema by the infarct area. The oedema size on T2w MR was significantly larger than the infarct size on DE MR in the acute phase. Both the oedema size on T2w MR and the infarct size on DE MR in the acute phase were significantly larger than those in the chronic phase. The O/I was significantly greater in the acute phase compared with that in the chronic phase (P < 0.05). An analysis of relative cumulative frequency distributions revealed an O/I of 1.4 as a cut-off value for differentiating acute from chronic myocardial damage with the sensitivity, specificity, and accuracy of 85.1%, 82.7% and 83.9%, respectively. The oedema-infarct ratio may be a useful index in differentiating acute from chronic myocardial damage in patients with MI. (orig.)

  11. Optimization of Contrast-to-Tissue Ratio by Adaptation of Transmitted Ternary Signal in Ultrasound Pulse Inversion Imaging

    Sébastien Ménigot


    Full Text Available Ultrasound contrast imaging has provided more accurate medical diagnoses thanks to the development of innovating modalities like the pulse inversion imaging. However, this latter modality that improves the contrast-to-tissue ratio (CTR is not optimal, since the frequency is manually chosen jointly with the probe. However, an optimal choice of this command is possible, but it requires precise information about the transducer and the medium which can be experimentally difficult to obtain, even inaccessible. It turns out that the optimization can become more complex by taking into account the kind of generators, since the generators of electrical signals in a conventional ultrasound scanner can be unipolar, bipolar, or tripolar. Our aim was to seek the ternary command which maximized the CTR. By combining a genetic algorithm and a closed loop, the system automatically proposed the optimal ternary command. In simulation, the gain compared with the usual ternary signal could reach about 3.9 dB. Another interesting finding was that, in contrast to what is generally accepted, the optimal command was not a fixed-frequency signal but had harmonic components.

  12. Fibrosis and postoperative fistula of the pancreas: correlation with MR imaging findings--preliminary results.

    Watanabe, Haruo; Kanematsu, Masayuki; Tanaka, Kaori; Osada, Shinji; Tomita, Hiroyuki; Hara, Akira; Goshima, Satoshi; Kondo, Hiroshi; Kawada, Hiroshi; Noda, Yoshifumi; Tanahashi, Yukichi; Kawai, Nobuyuki; Yoshida, Kazuhiro; Moriyama, Noriyuki


    To assess the potential value of magnetic resonance (MR) imaging in evaluating pancreatic fibrosis and predicting the development of postoperative pancreatic fistula. This retrospective study had institutional review board approval, and the requirement for informed consent was waived. MR images obtained in 29 consecutive patients (15 men, 14 women; mean age, 64.9 years; age range, 21-80 years) who underwent pancreatectomy were evaluated. The pancreas-to-muscle signal intensity (SI) ratio on unenhanced T1- and T2-weighted, dynamic contrast material-enhanced, and diffusion-weighted images and the apparent diffusion coefficient (ADC) of the pancreas were measured. MR imaging parameters were correlated with the degrees of pancreatic fibrosis and expression of activated pancreatic stellate cells (PSCs) by using univariate and multivariate regression analyses and receiver operating characteristic curve analysis. The relationships between the development of postoperative pancreatic fistula and the MR imaging measurements were examined by using logistic regression analysis and the Mann-Whitney U test. Multiple regression analysis showed that pancreas-to-muscle SI ratios on T1-weighted images and ADC values were independently associated with pancreatic fibrosis (r(2) = 0.66, P fistula (1.6 ± 0.2) than for those without (1.2 ± 0.2), and the odds ratio for postoperative pancreatic fistula was 21.3 in patients with an SI ratio of 1.41 and higher. The pancreas-to-muscle SI ratio on T1-weighted MR images of the pancreas may be a potential biomarker for assessment of pancreatic fibrosis and prediction of postoperative pancreatic fistula. RSNA, 2013

  13. The ESO Imaging Survey Status Report and Preliminary Results

    Da Costa, L N; Deul, E; Erben, T; Freudling, W; Guarnieri, M D; Hook, I; Hook, R N; Méndez, R; Nonino, M; Olsen, L; Prandoni, I; Renzini, A; Savaglio, S; Scodeggio, M; Silva, D; Slijkhuis, R; Wicenec, A; Wichmann, R; Benoist, C


    The ESO Imaging Survey (EIS) presented in early issues of the Messenger, and with up-to-date information on the ongoing observations available on the Web (, is a concerted effort by ESO and the Member State community to provide targets for the first year of operation of the VLT. It consists of two parts: a relatively wide-angle survey (EIS-WIDE) to cover four pre-selected patches of sky, 6 square degrees each, spread in right ascension to search for distant clusters and quasars and a deep, multicolor survey of four optical (SUSI-2) and two infrared (SOFI) covering the HST/Hubble Deep Field South (HDFS) and its flanking fields (EIS-DEEP). From the start, the main challenge has been to carry out a public survey in a limited amount of time requiring observations, software development and data reduction with the goal of distributing the survey data products before the call for proposal for the VLT. To cope with this one-year timetable, a novel type of collaboration between ESO and the commu...

  14. First results from the Jordan COLTRIMS imaging system

    Afaneh, Feras, E-mail: [Physics Department, The Hashemite University, Zarqa 13115 (Jordan); Ali, Rami; Qasem, Rajaie; Balasmeh, Naeem [Department of Physics, The University of Jordan, Amman 11942 (Jordan); Hamasha, Safeia [Physics Department, The Hashemite University, Zarqa 13115 (Jordan); Dörner, Reinhard; Schmidt-Böcking, Horst [Institut fuer Kernphysik, University Frankfurt, Max-von-Laue-Str. 1, 60438 Frankfurt (Germany)


    A Cold Target Recoil Ion Momentum Spectroscopy (COLTRIMS) apparatus has been constructed and operated cooperatively by the Atomic and Molecular Physics Laboratory in the Physics Department at the Hashemite University, Jordan, and the Atomic and Molecular Physics Group at the 4.75 MeV Van de Graaff Accelerator Facility at the University of Jordan. This COLTRIMS imaging system allows the investigation of the dynamics of various ion impact induced atomic and molecular interactions and fragmentations. The performance of the COLTRIMS system was tested by carrying out preliminary studies of two collision systems. In the first study, electron capture processes in the He{sup 2+}–Ne collision system at 0.25 and 1.0 MeV impact energies were investigated. Significant simultaneous electron capture and target excitation has been observed for the 0.25 MeV as opposed to the 1.0 MeV impact energy. In the other study, projectile single electron loss and simultaneous single target ionization in the O{sup +}–He collision system was studied at three different projectile impact energies: 0.6, 1.45 and 2 MeV. Enhancement of the electron–electron contribution to projectile electron loss with increasing collision energy has been observed.

  15. Pulsed thermographic inspection of CFRP structures: experimental results and image analysis tools

    Theodorakeas, P.; Avdelidis, N. P.; Ibarra-Castanedo, C.; Koui, M.; Maldague, X.


    In this study, three different CFRP specimens with internal artificial delaminations of various sizes and located at different depths were investigated by means of Pulsed Thermography (PT) under laboratory conditions. The three CFRP panels, having the same thickness and defects characteristics but with a different shape (planar, trapezoid and curved), were assessed after applying various signal processing tools on the acquired thermal data (i.e. Thermographic Signal Reconstruction, Pulsed Phase Thermography and Principal Component Thermography). The effectiveness of the above processing tools was initially evaluated in a qualitative manner, comparing the imaging outputs and the information retrieval in terms of defect detectability enhancement and noise reduction. Simultaneously, the produced defect detectability was evaluated through Signal-to-Noise Ratio (SNR) computations, quantifying the image quality and the intensity contrast produced between the defected area and the adjacent background area of the test panel. From the results of this study, it can be concluded that the implementation of PT along with the application of advanced signal processing algorithms can be a useful technique for NDT assessment, providing enhanced qualitative information. Nevertheless, SNR analysis showed that despite the enhanced visibility resulting from these algorithms, these can be properly applied in order to retrieve the best possible information according to the user's demands.

  16. MATLAB-based Applications for Image Processing and Image Quality Assessment – Part II: Experimental Results

    L. Krasula


    Full Text Available The paper provides an overview of some possible usage of the software described in the Part I. It contains the real examples of image quality improvement, distortion simulations, objective and subjective quality assessment and other ways of image processing that can be obtained by the individual applications.

  17. Magnetization transfer imaging of normal and abnormal testis: preliminary results

    Tsili, Athina C.; Ntorkou, Alexandra; Maliakas, Vasilios; Argyropoulou, Maria I. [University of Ioannina, Department of Clinical Radiology, Medical School, Ioannina (Greece); Baltogiannis, Dimitrios; Sylakos, Anastasios; Sofikitis, Nikolaos [University of Ioannina, Department of Urology, Medical School, Ioannina (Greece); Stavrou, Sotirios [University of Ioannina, Department of Urology, Medical School, Ioannina (Greece); University Hospital of Ioannina, Leoforos S. Niarchou, Department of Urology, Ioannina (Greece); Astrakas, Loukas G. [University of Ioannina, Department of Medical Physics, Medical School, Ioannina (Greece)


    The aim was to determine the magnetization transfer ratio (MTR) of normal testes, possible variations with age and to assess the feasibility of MTR in characterizing various testicular lesions. Eighty-six men were included. A three-dimensional gradient-echo MT sequence was performed, with/without an on-resonance binomial prepulse. MTR was calculated as: (SIo-SIm)/(SIo) x 100 %, where SIm and SIo refers to signal intensities with and without the saturation pulse, respectively. Subjects were classified as: group 1, 20-39 years; group 2, 40-65 years; and group 3, older than 65 years of age. Analysis of variance (ANOVA) followed by the least significant difference test was used to assess variations of MTR with age. Comparison between the MTR of normal testis, malignant and benign testicular lesions was performed using independent-samples t testing. ANOVA revealed differences of MTR between age groups (F = 7.51, P = 0.001). Significant differences between groups 1, 2 (P = 0.011) and 1, 3 (P < 0.001) were found, but not between 2, 3 (P = 0.082). The MTR (in percent) of testicular carcinomas was 55.0 ± 3.2, significantly higher than that of benign lesions (50.3 ± 4.0, P = 0.02) and of normal testes (47.4 ± 2.2, P < 0.001). MTR of normal testes decreases with age. MTR might be helpful in the diagnostic work-up of testicular lesions. (orig.)

  18. Unrequested imaging findings on routine chest CT : results from the PROVIDI study

    Gondrie, M.J.A.


    Prognostic research is of growing importance. However, rarely are results from imaging techniques considered for medical prognostication, whilst prognostically promising unrequested imaging findings are increasingly being detected in daily routine care. Therefore this thesis aimed to contribute to t

  19. Zinc isotope ratios of bones and teeth as new dietary indicators: results from a modern food web (Koobi Fora, Kenya)

    Jaouen, Klervia; Beasley, Melanie; Schoeninger, Margaret; Hublin, Jean-Jacques; Richards, Michael P.


    In order to explore the possibilities of using zinc (Zn) stable isotope ratios as dietary indicators, we report here on the measurements of the ratio of stable isotopes of zinc (66Zn/64Zn, expressed here as δ66Zn) in bioapatite (bone and dental enamel) of animals from a modern food web in the Koobi Fora region of the Turkana Basin in Kenya. We demonstrate that δ66Zn values in both bone and enamel allow a clear distinction between carnivores and herbivores from this food web. Differences were also observed between browsers and grazers as well as between carnivores that consumed bone (i.e. hyenas) compared to those that largely consume flesh (i.e. lions). We conclude that Zn isotope ratio measurements of bone and teeth are a new and promising dietary indicator.

  20. Low Lymphocyte Ratio as a Novel Prognostic Factor in Acute Heart Failure : Results from the Pre-RELAX-AHF Study

    Milo-Cotter, Olga; Teerlink, John R.; Metra, Marco; Felker, G. Michael; Ponikowski, Piotr; Voors, Adriaan A.; Edwards, Christopher; Weatherley, Beth Davison; Greenberg, Barry; Filippatos, Gerassimos; Unemori, Elaine; Teichman, Sam L.; Cotter, Gad


    Background: Previous studies have suggested that a lower lymphocyte ratio (Ly%) in the white blood cell (WBC) differential count is related to worse outcomes in patients with acute heart failure (AHF) and other cardiovascular disorders. Methods: In the Pre-RELAX-AHF study, 234 patients with AHF, sys

  1. The preoperative serum ratio of total prostate specific antigen (PSA to free testosterone (FT, PSA/FT index ratio, and prostate cancer. Results in 220 patients undergoing radical prostatectomy

    Antonio B. Porcaro


    Full Text Available Objectives: To evaluate associations of preoperative total prostate specific antigen (PSA to free testosterone (FT, the PSA/FT index ratio, with features of pathology prostate cancer (PCA and to investigate its prognostic potential in clustering the PCA population. Patients and methods: After excluding criteria, the records of 220 patients who underwent radical prostatectomy (RP were retrospectively reviewed. Serum samples of PSA, total testosterone (TT and FT were collected at 8.00 A.M., one month after biopsies and before RP. The PSA/FT ratio was computed in the population of patients who were clustered in groups according to ranking intervals of the PSA/FT ratio which identified at least 4 clusters which were coded as A, B, C, and D. The independent associations of the PSA/FT index ratio were assessed by statistical methods and a two-sided P < 0.05 was considered to indicate statistical significance. Results: TT correlated to FT which was a significant predictor of PSA in the population of patients who were subsequently clustered, according to increasing interval values of the PSA/FT index ratio, in groups that showed a stronger linear association of FT with PSA. The PSA/FT index ratio significantly associated with pathology features of prostate cancer such as pathology Gleason score (pGS, invasion of the seminal vesicles (pT3b, proportion of positive cores (P+ and proportion of cancer involving the volume of the prostate. In the population of patients, TT, PSA/FT index ratio and P+ independently associated with pGS ≥ 7 and pT3b; moreover, the odds ratio (OR of the PSA/FT index ratio resulted 9.11 which was stronger than TT (OR = 1.11 and P+ (OR = 8.84. In the PCA population, TT, PSA/FT index ratio and P+ also independently associated with pT3b PCA; interestingly, the OR of PSA/FT index resulted 54.91 which was stronger than TT (OR = 1.31 and P+ (26.43. Conclusions: Preoperative PSA/FT index ratio is an independent strong factor which

  2. Diagnostic value of transmural perfusion ratio derived from dynamic CT-based myocardial perfusion imaging for the detection of haemodynamically relevant coronary artery stenosis

    Coenen, Adriaan; Lubbers, Marisa M.; Dedic, Admir; Chelu, Raluca G.; Geuns, Robert-Jan M. van; Nieman, Koen [Erasmus University Medical Center, Department of Radiology, Rotterdam (Netherlands); Erasmus University Medical Center, Department of Cardiology, Rotterdam (Netherlands); Kurata, Akira; Kono, Atsushi; Dijkshoorn, Marcel L. [Erasmus University Medical Center, Department of Radiology, Rotterdam (Netherlands); Rossi, Alexia [Erasmus University Medical Center, Department of Radiology, Rotterdam (Netherlands); Barts Health NHS Trust, NIHR Cardiovascular Biomedical Research Unit at Barts, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London and Department of Cardiology, London (United Kingdom)


    To investigate the additional value of transmural perfusion ratio (TPR) in dynamic CT myocardial perfusion imaging for detection of haemodynamically significant coronary artery disease compared with fractional flow reserve (FFR). Subjects with suspected or known coronary artery disease were prospectively included and underwent a CT-MPI examination. From the CT-MPI time-point data absolute myocardial blood flow (MBF) values were temporally resolved using a hybrid deconvolution model. An absolute MBF value was measured in the suspected perfusion defect. TPR was defined as the ratio between the subendocardial and subepicardial MBF. TPR and MBF results were compared with invasive FFR using a threshold of 0.80. Forty-three patients and 94 territories were analysed. The area under the receiver operator curve was larger for MBF (0.78) compared with TPR (0.65, P = 0.026). No significant differences were found in diagnostic classification between MBF and TPR with a territory-based accuracy of 77 % (67-86 %) for MBF compared with 70 % (60-81 %) for TPR. Combined MBF and TPR classification did not improve the diagnostic classification. Dynamic CT-MPI-based transmural perfusion ratio predicts haemodynamically significant coronary artery disease. However, diagnostic performance of dynamic CT-MPI-derived TPR is inferior to quantified MBF and has limited incremental value. (orig.)

  3. Continuous H/V spectral ratio analysis of ambient noise: a necessity to understand microzonation results obtained by mobile stations

    Van Noten, Koen; Lecocq, Thomas


    Estimating the resonance frequency (f0) and amplification factor of unconsolidated sediments by H/V spectral ratio (HVSR) analysis of seismic ambient noise has been widely used since Nakamura's proposal in 1989. To measure f0 properly, Nakamura suggested to perform microzonation surveys at night when the artificial microtremor is small and does not fully disrupt the ambient seismic noise. As nightly fieldwork is not always a reasonable demand, we propose an alternative workflow of Nakamura's technique to improve the quality of HVSR results obtained by ambient noise measurements of mobile stations during the day. This new workflow includes the automated H/V calculation of continuous seismic data of a stationary or permanent station installed near the microzonation site for as long as the survey lasts in order to control the error in the HVSR analysis obtained by the mobile stations. In this presentation, we apply this workflow on one year of seismic data at two different case studies; i.e. a rural site with a shallow bedrock depth of 30 m and an urban site (Brussels, capital of Belgium, bedrock depth of 110 m) where human activity is continuous 24h/day. By means of an automated python script, the fundamental peak frequency and the H/V amplitude are automatically picked from H/V spectra that are calculated from 50% overlapping, 30 minute windows during the whole year. Afterwards, the f0 and amplitude picks are averaged per hour/per day for the whole year. In both case studies, the H/V amplitude and the fundamental frequencies range considerable, up to ˜15% difference between the daily and nightly measurements. As bedrock depth is known from boreholes at both sites, we concluded that the nightly picked f0 is the true one. Our results thus suggest that changes in the determined f0 and H/V amplitude are dominantly caused by the human behaviour which is stored in the ambient seismic noise (e.g. later onset of traffic in a weekend, quiet Sundays, differences between

  4. TU-EF-204-12: Quantitative Evaluation of Spectral Detector CT Using Virtual Monochromatic Images: Initial Results

    Duan, X; Guild, J [UT Southwestern Medical Center, Dallas, TX (United States); Arbique, G; Anderson, J [UT Southwestern Medical Ctr at Dallas, Dallas, TX (United States); Dhanantwari, A [Philips Healthcare, Highland Heights, OH (United States); Yagil, Y [Philips Medical Systems, Haifa (Israel)


    Purpose To evaluate the image quality and spectral information of a spectral detector CT (SDCT) scanner using virtual monochromatic (VM) energy images. Methods The SDCT scanner (Philips Healthcare) was equipped with a dual-layer detector and spectral iterative reconstruction (IR), which generates conventional 80–140 kV polychromatic energy (PE) CT images using both detector layers, PE images from the low-energy (upper) and high-energy (lower) detector layers and VM images. A solid water phantom with iodine (2.0–20.0 mg I/ml) and calcium (50.0–600.0 mg Ca/ml) rod inserts was used to evaluate effective energy estimate (EEE) and iodine contrast to noise ratio (CNR). The EEE corresponding to an insert CT number in a PE image was calculated from a CT number fit to the VM image set. Since PE image is prone to beam-hardening artifact EEE may underestimate the actual energy separation from two layers of the detector. A 30-cm-diameter water phantom was used to evaluate noise power spectrum (NPS). The phantoms were scanned at 120 and 140 kV with the same CTDIvol. Results The CT number difference for contrast inserts in VM images (50–150 keV) was 1.3±6% between 120 and 140 kV scans. The difference of EEE calculated from low- and high-energy detector images was 11.5 and 16.7 keV for 120 and 140 kV scans, respectively. The differences calculated from 140 and 100 kV conventional PE images were 12.8, and 20.1 keV from 140 and 80 kV conventional PE images. The iodine CNR increased monotonically with decreased keV. Compared to conventional PE images, the peak of NPS curves from VM images were shifted to lower frequency. Conclusion The EEE results indicates that SDCT at 120 and 140 kV may have energy separation comparable to 100/140 kV and 80/140 kV dual-kV imaging. The effects of IR on CNR and NPS require further investigation for SDCT. Author YY and AD are Philips Healthcare employees.

  5. A comparison with result of normalized image to different template image on statistical parametric mapping of ADHD children patients

    Shin, Dong Ho [Kyonggi University, Suwon (Korea, Republic of); Park, Soung Ock; Kwon, Soo Il [Dongnam Health College, Suwon (Korea, Republic of); Joh, Chol Woo; Yoon, Seok Nam [Medical College, Ajou University, Suwon (Korea, Republic of)


    We studied 64 ADHD children patients group (4 {approx} 15 ys, mean age: 8 {+-} 2.6 ys. M/F: 52/12) and 12 normal group (6 {approx} 7 ys, mean age: 9.4 {+-} 3.4 ys, M/F: 8/4) of the brain had been used to analysis of blood flow between normal and ADHD group. For analysis of Children ADHD, we used 12 children's mean brain images and made Template image of SPM99 program. In crease of blood flow (P-value 0.05), the result of normalized images to Template image to offer from SPM99 program, showed significant cluster in inter-Hemispheric and occipital Lobe, in the case of normalized images to children template image, showed inter-hemispheric and parietal lobe.

  6. Spatial extrapolation of lysimeter results using thermal infrared imaging

    Voortman, B. R.; Bosveld, F. C.; Bartholomeus, R. P.; Witte, J. P. M.


    Measuring evaporation (E) with lysimeters is costly and prone to numerous errors. By comparing the energy balance and the remotely sensed surface temperature of lysimeters with those of the undisturbed surroundings, we were able to assess the representativeness of lysimeter measurements and to quantify differences in evaporation caused by spatial variations in soil moisture content. We used an algorithm (the so called 3T model) to spatially extrapolate the measured E of a reference lysimeter based on differences in surface temperature, net radiation and soil heat flux. We tested the performance of the 3T model on measurements with multiple lysimeters (47.5 cm inner diameter) and micro lysimeters (19.2 cm inner diameter) installed in bare sand, moss and natural dry grass. We developed different scaling procedures using in situ measurements and remotely sensed surface temperatures to derive spatially distributed estimates of Rn and G and explored the physical soundness of the 3T model. Scaling of Rn and G considerably improved the performance of the 3T model for the bare sand and moss experiments (Nash-Sutcliffe efficiency (NSE) increasing from 0.45 to 0.89 and from 0.81 to 0.94, respectively). For the grass surface, the scaling procedures resulted in a poorer performance of the 3T model (NSE decreasing from 0.74 to 0.70), which was attributed to effects of shading and the difficulty to correct for differences in emissivity between dead and living biomass. The 3T model is physically unsound if the field scale average air temperature, measured at an arbitrarily chosen reference height, is used as input to the model. The proposed measurement system is relatively cheap, since it uses a zero tension (freely draining) lysimeter which results are extrapolated by the 3T model to the unaffected surroundings. The system is promising for bridging the gap between ground observations and satellite based estimates of E.

  7. Results of an Advanced Fan Stage Operating Over a Wide Range of Speed and Bypass Ratio. Part 2; Comparison of CFD and Experimental Results

    Celestina, Mark L.; Suder, Kenneth L.; Kulkarni, Sameer


    NASA and GE teamed to design and build a 57 percent engine scaled fan stage for a Mach 4 variable cycle turbofan/ramjet engine for access to space with multipoint operations. This fan stage was tested in NASA's transonic compressor facility. The objectives of this test were to assess the aerodynamic and aero mechanic performance and operability characteristics of the fan stage over the entire range of engine operation including: 1) sea level static take-off; 2) transition over large swings in fan bypass ratio; 3) transition from turbofan to ramjet; and 4) fan wind-milling operation at high Mach flight conditions. This paper will focus on an assessment of APNASA, a multistage turbomachinery analysis code developed by NASA, to predict the fan stage performance and operability over a wide range of speeds (37 to 100 percent) and bypass ratios.

  8. Quantitative estimation of a ratio of intracranial cerebrospinal fluid volume to brain volume based on segmentation of CT images in patients with extra-axial hematoma.

    Nguyen, Ha Son; Patel, Mohit; Li, Luyuan; Kurpad, Shekar; Mueller, Wade


    representing overall brain volume was calculated. Results CSF/brain volume ratio varied significantly during the course of the disease, being the lowest preoperatively, 0.051 ± 0.032; higher after surgical evacuation of hematoma, 0.067 ± 0.040; and highest at follow-up visit, 0.083 ± 0.040 ( p type of hematoma (odds ratio, 0.405; 95% CI, 0.303-0.540). Conclusion CSF/brain volume ratio calculated from CT images has potential to reflect dynamics of intracranial volume changes in patients with space-occupying mass.

  9. Signal-to-noise ratio enhancement on SEM images using a cubic spline interpolation with Savitzky-Golay filters and weighted least squares error.

    Kiani, M A; Sim, K S; Nia, M E; Tso, C P


    A new technique based on cubic spline interpolation with Savitzky-Golay smoothing using weighted least squares error filter is enhanced for scanning electron microscope (SEM) images. A diversity of sample images is captured and the performance is found to be better when compared with the moving average and the standard median filters, with respect to eliminating noise. This technique can be implemented efficiently on real-time SEM images, with all mandatory data for processing obtained from a single image. Noise in images, and particularly in SEM images, are undesirable. A new noise reduction technique, based on cubic spline interpolation with Savitzky-Golay and weighted least squares error method, is developed. We apply the combined technique to single image signal-to-noise ratio estimation and noise reduction for SEM imaging system. This autocorrelation-based technique requires image details to be correlated over a few pixels, whereas the noise is assumed to be uncorrelated from pixel to pixel. The noise component is derived from the difference between the image autocorrelation at zero offset, and the estimation of the corresponding original autocorrelation. In the few test cases involving different images, the efficiency of the developed noise reduction filter is proved to be significantly better than those obtained from the other methods. Noise can be reduced efficiently with appropriate choice of scan rate from real-time SEM images, without generating corruption or increasing scanning time.

  10. 基于局部边缘和变化率检测的无损图像压缩方法%A Lossless Image Compression Algorithm Based on Detection of Local Edge and Variance Ratio

    赵军; 王国胤; 吴中福; 吴渝; 李华


    In this paper,a new predictive coding algorithm is presented for lossless image compression. This algorithm considers both the local edge and the variance ratio of pixel value in prediction process. It further reduces the entropy of the predictive error image with error feedback technology. Simulation results show that the performance of this algorithm is better than not only the standard algorithm(LOCO_I)provided by JPEG_LS ,but also CALIC, which is the state-of-art in the literature of image compression.

  11. Polar Bear UV Imaging of Airglow and Aurora - Image Processing and Results


    in time) over the first half year of Polar BEAR’s life in 12 orbit by plotting a few dosen panes randomly chosen from that era. Figure 5 shows the...intend to expand our processing in the future to include dosens of images in each map. Thus this point, at least regarding the statistical validity of

  12. Improved signal-to-noise ratio performance in magnetic resonance imaging by using a multilayered surface coil array--a simulation study.

    Liang, Dandan; Hui, Hon Tat; Yeo, Tat Soon


    A multilayered surface coil array for magnetic resonance imaging with an improved signal-to-noise ratio (SNR) performance is introduced and investigated by a simulation study. By using an effective decoupling method, the strong mutual coupling effect between the coil layers can be accurately removed, leading to a coherent combination of the signals of the individual coils. This results in a much stronger received signal power which increases with the number of coil layers in the array. This, together with a smaller rate of increase of noise power with the number of coil layers, leads to a net increase in the SNR of array output with the number of coil layers in the array. Rigorous numerical simulation examples have been carried out to confirm and verify the performance of the new array.

  13. Impact of disclosure of individual imaging results in a multi-center Parkinson clinical trial.

    Jennings, Danna; Eberly, Shirley; Oakes, David; Seibyl, John; Marek, Ken; Shoulson, Ira


    Little is known about the impact of providing individual research results to clinical trial participants or the impact of sharing such data. The objective of this follow-up study was to evaluate the desire of participants for learning their imaging results and the impact of this information on their perception of their PD diagnosis and care. The Parkinson Research Examination of CEP-1347 Trial (PRECEPT) evaluated the experimental treatment CEP-1347 obtaining dopamine transporter imaging at baseline and 22 months as a secondary outcome. Dopamine transporter imaging and results were categorized as 'dopamine transporter deficit', 'no dopamine transporter deficit' or 'indeterminate.' Self-administered surveys were provided on three occasions to subjects who chose to learn their dopamine transporter imaging results: prior to receiving imaging data, immediately following receipt of imaging information, and three months following image disclosure. 656/777 subjects (84.4%) consented to receive their individual imaging data, comprising overall result categories of 86.3% 'dopamine transporter deficit', 10.4% 'no dopamine transporter deficit', and 3.4% 'indeterminate.' 99.6% of subjects believed their decision to receive data was correct. Following disclosure of imaging results, 97% of the 'dopamine transporter deficit' and 'indeterminate' subjects believed they had Parkinson disease compared with 34% of 'no dopamine transporter deficit' subjects. About 45% of participants reported that learning individual imaging data resulted in improved understanding of their diagnosis. The majority of research participants chose to learn their individual dopamine transporter imaging results and were satisfied with their decision. Disclosure of imaging information resulted in improved understanding of parkinsonian symptoms in nearly half of subjects, and less belief among 'no dopamine transporter deficit' subjects that they had a diagnosis of Parkinson disease.

  14. Improving Landsat and IRS Image Classification: Evaluation of Unsupervised and Supervised Classification through Band Ratios and DEM in a Mountainous Landscape in Nepal

    Krishna Bahadur K.C.


    Full Text Available Modification of the original bands and integration of ancillary data in digital image classification has been shown to improve land use land cover classification accuracy. There are not many studies demonstrating such techniques in the context of the mountains of Nepal. The objective of this study was to explore and evaluate the use of modified band and ancillary data in Landsat and IRS image classification, and to produce a land use land cover map of the Galaudu watershed of Nepal. Classification of land uses were explored using supervised and unsupervised classification for 12 feature sets containing the LandsatMSS, TM and IRS original bands, ratios, normalized difference vegetation index, principal components and a digital elevation model. Overall, the supervised classification method produced higher accuracy than the unsupervised approach. The result from the combination of bands ration 4/3, 5/4 and 5/7 ranked the highest in terms of accuracy (82.86%, while the combination of bands 2, 3 and 4 ranked the lowest (45.29%. Inclusion of DEM as a component band shows promising results.

  15. Compression of digital images in radiology. Results of a consensus conference; Kompression digitaler Bilddaten in der Radiologie. Ergebnisse einer Konsensuskonferenz

    Loose, R. [Klinikum Nuernberg-Nord (Germany). Inst. fuer Diagnostische und Interventionelle Radiologie; Braunschweig, R. [BG Kliniken Bergmannstrost, Halle/Saale (Germany). Klinik fuer Bildgebende Diagnostik und Interventionsradiologie; Kotter, E. [Universitaetsklinikum Freiburg (Germany). Abt. Roentgendiagnostik; Mildenberger, P. [Mainz Univ. (Germany). Klinik und Poliklinik fuer Diagnostische und Interventionelle Radiologie; Simmler, R.; Wucherer, M. [Klinikum Nuernberg (Germany). Inst. fuer Medizinische Physik


    Purpose: Recommendations for lossy compression of digital radiological DICOM images in Germany by means of a consensus conference. The compression of digital radiological images was evaluated in many studies. Even though the results demonstrate full diagnostic image quality of modality-dependent compression between 1:5 and 1:200, there are only a few clinical applications. Materials and Methods: A consensus conference with approx. 80 interested participants (radiology, industry, physics, and agencies) without individual invitation was organized by the working groups AGIT and APT of the German Roentgen Society DRG to determine compression factors without loss of diagnostic image quality for different anatomical regions for CT, CR/DR, MR, RF/XA examinations. The consent level was specified as at least 66 %. Results: For individual modalities the following compression factors were recommended: CT (brain) 1:5, CT (all other applications) 1:8, CR/DR (all applications except mammography) 1:10, CR/DR (mammography) 1:15, MR (all applications) 1:7, RF/XA (fluoroscopy, DSA, cardiac angio) 1:6. The recommended compression ratios are valid for JPEG and JPEG 2000 /Wavelet compressions. Conclusion: The results may be understood as recommendations and indicate limits of compression factors with no expected reduction of diagnostic image quality. They are similar to the current national recommendations for Canada and England. (orig.)

  16. Image restoration by the method of convex projections: part 2 applications and numerical results.

    Sezan, M I; Stark, H


    The image restoration theory discussed in a previous paper by Youla and Webb [1] is applied to a simulated image and the results compared with the well-known method known as the Gerchberg-Papoulis algorithm. The results show that the method of image restoration by projection onto convex sets, by providing a convenient technique for utilizing a priori information, performs significantly better than the Gerchberg-Papoulis method.

  17. Visual feedback of individuals' medical imaging results for changing health behaviour.

    Hollands, Gareth J; Hankins, Matthew; Marteau, Theresa M


    Feedback of medical imaging results can reveal visual evidence of actual bodily harm attributable to a given behaviour. This may offer a particularly promising approach to motivating changes in health behaviour to decrease risk. Applicable behaviours include smoking cessation, skin self-examination, sun protection behaviour, dietary intake, physical activity and medication usage. The current review assembles and evaluates the evidence concerning the behavioural impact of showing and explaining images, in order to determine whether their communication is an effective intervention approach. To assess the extent to which feedback to individuals of images of their own bodies created during medical imaging procedures increases or decreases a range of health behaviours. We searched the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 3 2009), MEDLINE (1950 to 14 September 2009), EMBASE (1980 to 14 September 2009), CINAHL (1982 to 9 October 2009), PsycINFO (1806 to 14 September 2009) and reference lists of articles. We also contacted authors of selected papers, and searched the ProQuest Dissertations and Theses database on 1 October 2009 for grey literature. Randomised or quasi-randomised controlled trials involving adult (18 years and over) non-pregnant individuals undergoing medical imaging procedures assessing risk of disease or of an existing condition, for which personal risk may be reduced by modification of behaviour. The sole or principal component of included interventions is visual feedback of individuals' medical imaging results, defined as individuals being shown, and having explained, source images (still or moving images) of their bodies generated by the procedure. Two authors searched for studies and independently extracted data from included studies, with disagreements resolved by consensus and a third author acting as arbiter. The risk of bias of included studies was assessed and reported in accordance with the

  18. Quantitative differentiation of breast lesions at 3T diffusion-weighted imaging (DWI) using the ratio of distributed diffusion coefficient (DDC).

    Ertas, Gokhan; Onaygil, Can; Akin, Yasin; Kaya, Handan; Aribal, Erkin


    To investigate the accuracy of diffusion coefficients and diffusion coefficient ratios of breast lesions and of glandular breast tissue from mono- and stretched-exponential models for quantitative diagnosis in diffusion-weighted magnetic resonance imaging (MRI). We analyzed pathologically confirmed 170 lesions (85 benign and 85 malignant) imaged using a 3.0T MR scanner. Small regions of interest (ROIs) focusing on the highest signal intensity for lesions and also for glandular tissue of contralateral breast were obtained. Apparent diffusion coefficient (ADC) and distributed diffusion coefficient (DDC) were estimated by performing nonlinear fittings using mono- and stretched-exponential models, respectively. Coefficient ratios were calculated by dividing the lesion coefficient by the glandular tissue coefficient. A stretched exponential model provides significantly better fits then the monoexponential model (P correlation was found in diffusion coefficients (0.99-0.81 and coefficient ratios (0.94) between the models. The highest diagnostic accuracy was found by the DDC ratio (area under the curve [AUC] = 0.93) when compared with lesion DDC, ADC ratio, and lesion ADC (AUC = 0.91, 0.90, 0.90) but with no statistically significant difference (P > 0.05). At optimal thresholds, the DDC ratio achieves 93% sensitivity, 80% specificity, and 87% overall diagnostic accuracy, while ADC ratio leads to 89% sensitivity, 78% specificity, and 83% overall diagnostic accuracy. The stretched exponential model fits better with signal intensity measurements from both lesion and glandular tissue ROIs. Although the DDC ratio estimated by using the model shows a higher diagnostic accuracy than the ADC ratio, lesion DDC, and ADC, it is not statistically significant. J. Magn. Reson. Imaging 2016;44:1633-1641. © 2016 International Society for Magnetic Resonance in Medicine.

  19. Technical note: Evaluation of the uncertainties in (choline+creatine)/citrate ratios measured by proton MR spectroscopic imaging in patients suspicious for prostate cancer

    Zbyn, S.; Krssak, M.; Memarsadeghi, M.; Gholami, B.; Haitel, A.; Weber, M.; Helbich, T.H.; Trattnig, S.; Moser, E.; Gruber, S.


    The presented evaluation of the relative uncertainty (δ'CCC) of the (choline + creatine)/citrate (CC/C) ratios can provide objective information about the quality and diagnostic value of prostate MR spectroscopic imaging data. This information can be combined with the numeric values of CC/C ratios and provides metabolic-quality maps enabling accurate cancer detection and user-independent data evaluation. In addition, the prostate areas suffering most from the low precision of CC/C ratios (e. g., prostate base) were identified.

  20. Mosquitofish (Gambusia affinis preference and behavioral response to animated images of conspecifics altered in their color, aspect ratio, and swimming depth.

    Giovanni Polverino

    Full Text Available Mosquitofish (Gambusia affinis is an example of a freshwater fish species whose remarkable diffusion outside its native range has led to it being placed on the list of the world's hundred worst invasive alien species (International Union for Conservation of Nature. Here, we investigate mosquitofish shoaling tendency using a dichotomous choice test in which computer-animated images of their conspecifics are altered in color, aspect ratio, and swimming level in the water column. Pairs of virtual stimuli are systematically presented to focal subjects to evaluate their attractiveness and the effect on fish behavior. Mosquitofish respond differentially to some of these stimuli showing preference for conspecifics with enhanced yellow pigmentation while exhibiting highly varying locomotory patterns. Our results suggest that computer-animated images can be used to understand the factors that regulate the social dynamics of shoals of Gambusia affinis. Such knowledge may inform the design of control plans and open new avenues in conservation and protection of endangered animal species.

  1. Ratios among atmospheric trace gases together with winds imply exploitable information for bird navigation: a model elucidating experimental results

    Wallraff, H. G.


    A model of avian goal-oriented navigation is described that is based on two empirical findings building a bridge from ornithology to atmospheric chemistry. (1) To orient their courses homeward from distant unfamiliar areas, homing pigeons require long-term exposure to undisturbed winds at the home site and olfactory access to the environmental air at home and abroad. (2) Above Germany, ratios among some atmospheric trace gases vary along differently oriented spatial gradients as well as depending on wind direction. The model emulates finding (1) by utilising the analysed air samples on which finding (2) is based. Starting with an available set of 46 omnipresent compounds, virtual pigeons determine the profile of relative weights among them at each of 96 sites regularly distributed around a central home site within a radius of 200 km and compare this profile with corresponding profiles determined at home under varying wind conditions. Referring to particular similarities and dissimilarities depending on home-wind direction, they try to estimate, at each site, the compass direction they should fly in order to approach home. To make the model work, an iterative algorithm imitates evolution by modifying sensitivity to the individual compounds stepwise at random. In the course of thousands of trial-and-error steps it gradually improves homeward orientation by selecting smaller sets of most useful and optimally weighted substances from whose proportional configurations at home and abroad it finally derives navigational performances similar to those accomplished by real pigeons. It is concluded that the dynamic chemical atmosphere most likely contains sufficient spatial information for home-finding over hundreds of kilometres of unfamiliar terrain. The underlying chemo-atmospheric processes remain to be clarified.

  2. Comparison of stroke infarction between CT perfusion and diffusion weighted imaging: preliminary results

    Abd. Rahni, Ashrani Aizzuddin; Arka, Israna Hossain; Chellappan, Kalaivani; Mukari, Shahizon Azura; Law, Zhe Kang; Sahathevan, Ramesh


    In this paper we present preliminary results of comparison of automatic segmentations of the infarct core, between that obtained from CT perfusion (based on time to peak parameter) and diffusion weighted imaging (DWI). For each patient, the two imaging volumes were automatically co-registered to a common frame of reference based on an acquired CT angiography image. The accuracy of image registration is measured by the overlap of the segmented brain from both images (CT perfusion and DWI), measured within their common field of view. Due to the limitations of the study, DWI was acquired as a follow up scan up to a week after initial CT based imaging. However, we found significant overlap of the segmented brain (Jaccard indices of approximately 0.8) and the percentage of infarcted brain tissue from the two modalities were still fairly highly correlated (correlation coefficient of approximately 0.9). The results are promising with more data needed in future for clinical inference.

  3. Evaluation of browning ratio in an image analysis of apple slices at different stages of instant controlled pressure drop-assisted hot-air drying (AD-DIC).

    Gao, Kun; Zhou, Linyan; Bi, Jinfeng; Yi, Jianyong; Wu, Xinye; Zhou, Mo; Wang, Xueyuan; Liu, Xuan


    Computer vision-based image analysis systems are widely used in food processing to evaluate quality changes. They are able to objectively measure the surface colour of various products since, providing some obvious advantages with their objectivity and quantitative capabilities. In this study, a computer vision-based image analysis system was used to investigate the colour changes of apple slices dried by instant controlled pressure drop-assisted hot air drying (AD-DIC). The CIE L* value and polyphenol oxidase activity in apple slices decreased during the entire drying process, whereas other colour indexes, including CIE a*, b*, ΔE and C* values, increased. The browning ratio calculated by image analysis increased during the drying process, and a sharp increment was observed for the DIC process. The change in 5-hydroxymethylfurfural (5-HMF) and fluorescent compounds (FIC) showed the same trend with browning ratio due to Maillard reaction. Moreover, the concentrations of 5-HMF and FIC both had a good quadratic correlation (R(2)  > 0.998) with the browning ratio. Browning ratio was a reliable indicator of 5-HMF and FIC changes in apple slices during drying. The image analysis system could be used to monitor colour changes, 5-HMF and FIC in dehydrated apple slices during the AD-DIC process. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  4. Prenatal diagnosis of fetal respiratory function: evaluation of fetal lung maturity using lung-to-liver signal intensity ratio at magnetic resonance imaging.

    Oka, Yasuko; Rahman, Mosfequr; Sasakura, Chihaya; Waseda, Tomoo; Watanabe, Yukio; Fujii, Ryota; Makinoda, Satoru


    The purpose of this retrospective study is to determine the fetal lung-to-liver signal intensity ratio (LLSIR) on T2-weighted images for the prediction of neonatal respiratory outcome. One hundred ten fetuses who underwent magnetic resonance imaging (MRI) examination for various indications after 22 weeks of gestation participated in this study. LLSIR was measured as the ratio of signal intensities of the fetal lung and liver on T2-weighted images at MRI. We examined the changes of the ratio with advancing gestation and the relations between LLSIR and the presence of the severe respiratory disorder (SRD) after birth. The best cut-off value of the LLSIR to predict respiratory outcome after birth was calculated using receiver operating characteristic (ROC) curve analysis. Lung-to-liver signal intensity ratio correlated significantly with advancing gestational age (R = 0.35, p fetal LLSIR on T2-weighted images is an accurate marker to diagnose the fetal lung maturity. © 2014 The Authors. Prenatal Diagnosis published by John Wiley & Sons, Ltd.

  5. Impact of concomitant medication use on myocardial 123I-mIBG imaging results in patients with heart failure.

    Jacobson, Arnold F; White, Susan; Travin, Mark I; Tseng, Carol


    Medications that interfere with sympathetic neuronal norepinephrine uptake and storage, such as neuropsychiatrics (NP) and sympathomimetic amines, are most likely to affect cardiac uptake of iodine-123 metaiodobenzylguanidine (I-mIBG). The present study examined these and other medications reported to affect I-mIBG uptake using measurements of cardiac I-mIBG uptake on the heart failure (HF) patients in the ADMIRE-HF extension (X) study. Baseline concomitant medications taken by the 961 HF patients were categorized into five groups: calcium channel blockers, NP medications, β agonists and sympathomimetics, α antagonists, and other antihypertensives. NP medications were further subcategorized into those expected to have high and low impact on norepinephrine transporter (NET) function. Myocardial I-mIBG heart/mediastinum (H/M) uptake ratios on 4 h planar images were compared among the groups. Impact of medication group on the prognostic value of the H/M ratio for all-cause (AC) and cardiac death during a median 2-year follow-up was also examined. A total of 283 (29%) patients were using at least one calcium channel blocker, NP medication, or β agonist or sympathomimetic. These patients had a lower mean H/M ratio than the other study patients (1.42±0.20 vs. 1.45±0.20; P=0.022). However, the 2-year AC mortality rates in the two groups were the same [11.3% (95% confidence interval: 7.5-15.2%) vs. 11.8% (95% confidence interval: 9.2-14.4%)]. In terms of medication categories, there were no significant differences in the mean H/M ratios between patients who did and did not use NP medications, β agonists, calcium channel blockers, and α antagonists. Across all categories, patients with H/M ratio greater than or equal to 1.60 had lower AC and cardiac mortality. Patients using higher potency (for NET inhibition) NP medications had significantly lower H/M ratio values, but the prognostic significance of H/M ratio greater than or equal to 1.60 was unchanged. Only a

  6. Four-Dimensional Magnetic Resonance Imaging Using Axial Body Area as Respiratory Surrogate: Initial Patient Results

    Yang, Juan [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); School of Information Science and Engineering, Shandong University, Jinan, Shandong (China); Cai, Jing [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Wang, Hongjun [School of Information Science and Engineering, Shandong University, Jinan, Shandong (China); Chang, Zheng; Czito, Brian G. [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Bashir, Mustafa R. [Department of Radiology, Duke University Medical Center, Durham, North Carolina (United States); Yin, Fang-Fang, E-mail: [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States)


    Purpose: To evaluate the feasibility of a retrospective binning technique for 4-dimensional magnetic resonance imaging (4D-MRI) using body area (BA) as a respiratory surrogate. Methods and Materials: Seven patients with hepatocellular carcinoma (4 of 7) or liver metastases (3 of 7) were enrolled in an institutional review board-approved prospective study. All patients were simulated with both computed tomography (CT) and MRI to acquire 3-dimensinal and 4D images for treatment planning. Multiple-slice multiple-phase cine-MR images were acquired in the axial plane for 4D-MRI reconstruction. Image acquisition time per slice was set to 10-15 seconds. Single-slice 2-dimensinal cine-MR images were also acquired across the center of the tumor in orthogonal planes. Tumor motion trajectories from 4D-MRI, cine-MRI, and 4D-CT were analyzed in the superior–inferior (SI), anterior–posterior (AP), and medial–lateral (ML) directions, respectively. Their correlation coefficients (CC) and differences in tumor motion amplitude were determined. Tumor-to-liver contrast-to-noise ratio (CNR) was measured and compared between 4D-CT, 4D-MRI, and conventional T2-weighted fast spin echo MRI. Results: The means (±standard deviations) of CC comparing 4D-MRI with cine-MRI were 0.97 ± 0.03, 0.97 ± 0.02, and 0.99 ± 0.04 in SI, AP, and ML directions, respectively. The mean differences were 0.61 ± 0.17 mm, 0.32 ± 0.17 mm, and 0.14 ± 0.06 mm in SI, AP, and ML directions, respectively. The means of CC comparing 4D-MRI and 4D-CT were 0.95 ± 0.02, 0.94 ± 0.02, and 0.96 ± 0.02 in SI, AP, and ML directions, respectively. The mean differences were 0.74 ± 0.02 mm, 0.33 ± 0.13 mm, and 0.18 ± 0.07 mm in SI, AP, and ML directions, respectively. The mean tumor-to-tissue CNRs were 2.94 ± 1.51, 19.44 ± 14.63, and 39.47 ± 20.81 in 4D-CT, 4D-MRI, and T2-weighted MRI, respectively. Conclusions: The preliminary evaluation of our 4D-MRI technique results in oncologic patients demonstrates its

  7. Initial Results from Fitting p-Modes Using Intensity Observations from the Helioseismic and Magnetic Imager

    Korzennik, Sylvain G.


    The Helioseismic and Magnetic Imager project recently started processing the continuum-intensity images following global helioseismology procedures similar to those used to process the velocity images. The spatial decomposition of these images has produced time series of spherical harmonic coefficients for degrees up to ℓ=300, using a different apodization than the one used for velocity observations. The first 360 days of observations were processed and are made available. I present initial results from fitting these time series using my fitting method and compare the derived mode characteristics to those estimated using coeval velocity observations.

  8. Improved Method of Detection Falsification Results the Digital Image in Conditions of Attacks

    Kobozeva A.A.


    Full Text Available The modern level of information technologies development has led to unheard ease embodiments hitherto unauthorized modifications of digital content. At the moment, very important question is the effective expert examination of authenticity of digital images, video, audio, development of the methods for identification and localization of violations of their integrity using these contents for purposes other than entertainment. Present paper deals with the improvement of the detection method of the cloning results in digital images - one of the most frequently used in the software tools falsification realized in all modern graphics editors. The method is intended for clone detection areas and pre-image in terms of additional disturbing influences in the image after the cloning operation for "masking" of the results, which complicates the search process. The improvement is aimed at reducing the number of "false alarms", when the area of the clone / pre-image detected in the original image or the localization of the identified areas do not correspond to the real clone and pre-image. The proposed improvement, based on analysis of different sizes per-pixel image blocks with the least difference from each other, has made it possible efficient functioning of the method, regardless of the specificity of the analyzed digital image.

  9. Particle image velocimetry - Principles and first results; La velocimetrie par images de particules. Principes et premiers resultats

    Laporta, A.; Marechal, J.P. [Electricite de France (EDF), Direction des Etudes et Recherches, 92 - Clamart (France)


    Particle Image Velocimetry (PIV) is a measurement technique elaborated towards the end of the 1970`s, but which has developed considerably in recent years. The general principle of PIV is very simple and enables access to instantaneous velocity fields. It consists in recording images of tracer-particles injected into the flow and determining the distance covered by these particles. Since we know the time lapse between successive images of the same particle, we can derive the local fluid velocity. Among the many existing image acquisition and processing methods, the image inter-correlation analysis techniques, used with a pulsed laser source, is the most effective. Since we know the influence of different parameters (number of particles, beam power, time lapse between two successive images, size of query zones, etc.) on the quality of the final result, we can optimize practical adjustment of the PIV measurement scheme. The PIV was tested on the LAVITA hydraulic mockup (simulating the operation of a tangential fan). First results are, all in all, highly satisfactory. These have enabled the rapid drafting of instantaneous mean velocity field maps (20 images acquired in less than 90 seconds, with a post-processing time of about 10 minutes). Observation of the instantaneous fields has evidenced the presence of low frequency non-stationary phenomena which are not revealed by Laser Doppler Velocimetry (LDV). Quantitative comparison between LDV and PIV, concerning average fields, showed close results, with, however, local divergences which could be relatively marked. It must nevertheless be noted that the PIV measurements performed on LAVITA have not been optimized with a view to obtaining a consistently good accuracy level. Priority in the present case was given to the scope of the field explored, with a view to observing the large non-stationary structures within a flow. The PIV measurement technique is thus operational for prompt flow characterization. However

  10. Cardiothoracic ratio on chest radiograph in pediatric heart disease: How does it correlate with heart volumes at magnetic resonance imaging?

    Grotenhuis, Heynric B. [The University of Toronto, Division of Cardiology, Department of Paediatrics, The Labatt Family Heart Centre, The Hospital for Sick Children, Toronto (Canada); Zhou, Cheng; Isaac, Kathryn V. [The University of Toronto, Department of Diagnostic Imaging, The Hospital for Sick Children, Toronto (Canada); Tomlinson, George [University of Toronto, Department of Medicine, Toronto General Hospital and Mt. Sinai Hospital, Toronto (Canada); Seed, Mike; Grosse-Wortmann, Lars; Yoo, Shi-Joon [The University of Toronto, Division of Cardiology, Department of Paediatrics, The Labatt Family Heart Centre, The Hospital for Sick Children, Toronto (Canada); The University of Toronto, Department of Diagnostic Imaging, The Hospital for Sick Children, Toronto (Canada)


    The cardiothoracic ratio by chest radiograph is widely used as a marker of cardiac size. The purpose of this study is to correlate cardiothoracic ratio and cardiac volumes as measured by cardiovascular magnetic resonance (MR) in common structural and myopathic heart disease with increased cardiac size due to volume overload or hypertrophy. A retrospective single center study was performed in all patients between 2007 and 2013 with repaired tetralogy of Fallot (TOF), aortic regurgitation, isolated left-to-right shunt and hypertrophic cardiomyopathy (HCM) who underwent cardiovascular MR and chest radiograph within 6 months of each other. Cardiothoracic ratios by chest radiograph (frontal and lateral) were compared to cardiac volumes (indexed for body surface area) by cardiovascular MR. One hundred twenty-seven patients (mean age: 11.2 ± 5.5 years) were included in this study (76 with TOF, 23 with isolated left-to-right shunt, 16 with aortic regurgitation and 12 with HCM). Frontal cardiothoracic ratio of all groups correlated with indexed right ventricular (RV) end-diastolic volume (EDVI) (r = 0.40, P < 0.01) and indexed total heart volume (THVI) (r = 0.27, P < 0.01). In TOF patients, frontal cardiothoracic ratio correlated with RVEDVI (r = 0.34, P < 0.01; coefficient of variation = 27.6%), indexed RV end-systolic volume (ESVI) (r = 0.44, P < 0.01; coefficient of variation = 33.3%) and THVI (r = 0.35, P < 0.01; coefficient of variation = 19.6%), although RV volumes and THVI showed widespread variation given the high coefficients of variation. In patients with aortic regurgitation, frontal cardiothoracic ratio correlated with left ventricular (LV) EDVI (r = 0.50, P = 0.047), but not with THVI and aortic regurgitant fraction, and widespread variation for LV EDVI (coefficient of variation = 19.2%), LV ESVI (coefficient of variation = 32.5%) and THVI (coefficient of variation = 13.6%) was also observed. Frontal cardiothoracic ratio was not correlated with cardiac volumes

  11. Isomeric cross-section ratios resulted from reaction (p,n) on targets {sup 100}Ru and {sup 104,106,110}Pd

    Hu Bitao [Lanzhou Univ., Gansu (China). Dept. of Modern Physics; Zarubin, P.P.; Juravlev, U.U. [Faculty of Physics, Saint-Petersburg University, Saint-Petersburg (Russian Federation)


    The isomeric cross section ratios for production {sup 100mg}Rh and {sup 104mg,106mg,110mg}Ag in reaction (p,n) were measured over energy range from {proportional_to}6 MeV to {proportional_to}9 MeV. Statistical model calculations were performed for analyzing the experimental isomeric ratios and it was found that the theoretically calculated ratios agree well with our experimental results. In the present work the tendency that theoretical values will be larger than experimental results for energy above 9 MeV was indicated and the influence of the optical model parameters and the level density model was discussed. (orig.) With 6 figs., 5 tabs., 17 refs.

  12. Detectability comparison between a high energy x-ray phase sensitive and mammography systems in imaging phantoms with varying glandular-adipose ratios

    Ghani, Muhammad U.; Wong, Molly D.; Wu, Di; Zheng, Bin; Fajardo, Laurie L.; Yan, Aimin; Fuh, Janis; Wu, Xizeng; Liu, Hong


    The objective of this study was to demonstrate the potential benefits of using high energy x-rays in comparison with the conventional mammography imaging systems for phase sensitive imaging of breast tissues with varying glandular-adipose ratios. This study employed two modular phantoms simulating the glandular (G) and adipose (A) breast tissue composition in 50 G-50 A and 70 G-30 A percentage densities. Each phantom had a thickness of 5 cm with a contrast detail test pattern embedded in the middle. For both phantoms, the phase contrast images were acquired using a micro-focus x-ray source operated at 120 kVp and 4.5 mAs, with a magnification factor (M) of 2.5 and a detector with a 50 µm pixel pitch. The mean glandular dose delivered to the 50 G-50 A and 70 G-30 A phantom sets were 1.33 and 1.3 mGy, respectively. A phase retrieval algorithm based on the phase attenuation duality that required only a single phase contrast image was applied. Conventional low energy mammography images were acquired using GE Senographe DS and Hologic Selenia systems utilizing their automatic exposure control (AEC) settings. In addition, the automatic contrast mode (CNT) was also used for the acquisition with the GE system. The AEC mode applied higher dose settings for the 70 G-30 A phantom set. As compared to the phase contrast images, the dose levels for the AEC mode acquired images were similar while the dose levels for the CNT mode were almost double. The observer study, contrast-to-noise ratio and figure of merit comparisons indicated a large improvement with the phase retrieved images in comparison to the AEC mode images acquired with the clinical systems for both density levels. As the glandular composition increased, the detectability of smaller discs decreased with the clinical systems, particularly with the GE system, even at higher dose settings. As compared to the CNT mode (double dose) images, the observer study also indicated that the phase retrieved images provided

  13. Variance Owing to Observer, Repeat Imaging, and Fundus Camera Type on Cup-to-disc Ratio Estimates by Stereo Planimetry

    Kwon, Young H.; Adix, Michael; Zimmerman, M. Bridget; Piette, Scott; Greenlee, Emily C.; Alward, Wallace L. M.; Abramoff, M.D.


    Objective: To determine and compare variance components in linear cup-to-disc ratio (LCDR) estimates by computer-assisted planimetry by human experts, and automated machine algorithm (digital automated planimetry). Design: Prospective case series for evaluation of planimetry.

  14. Savanna grass nitrogen to phosphorus ratio estimation using field spectroscopy and the potential for estimation with imaging spectroscopy

    Ramoelo, Abel


    Full Text Available Determining the foliar N: P ratio provides a tool for understanding nutrient limitation on plant production and consequently for the feeding patterns of herbivores. In order to understand the nutrient limitation at landscape scale, remote sensing...

  15. Iodine potassium iodide improves the contrast-to-noise ratio of micro-computed tomography images of the human middle ear.

    Rohani, S A; Ghomashchi, S; Umoh, J; Holdsworth, D W; Agrawal, S K; Ladak, H M


    High-resolution imaging of middle-ear geometry is necessary for finite-element modeling. Although micro-computed tomography (microCT) is widely used because of its ability to image bony structures of the middle ear, it is difficult to visualize soft tissues - including the tympanic membrane and the suspensory ligaments/tendons - because of lack of contrast. The objective of this research is to quantitatively evaluate the efficacy of iodine potassium iodide (IKI) solution as a contrast agent. Six human temporal bones were used in this experiment, which were obtained in right-left pairs, from three cadaveric heads. All bones were fixed using formaldehyde. Three bones (one from each pair) were stained in IKI solution for 2 days, whereas the other three were not stained. Samples were scanned using a microCT system at a resolution of 20 μm. Eight soft tissues in the middle ear were segmented: anterior mallear ligament, incudomallear joint, lateral mallear ligament, posterior incudal ligament, stapedial annular ligament, stapedius muscle, tympanic membrane and tensor tympani muscle. Contrast-to-noise ratios (CNRs) of each soft tissue were calculated for each temporal bone. Combined CNRs of the soft tissues in unstained samples were 6.1 ± 3.0, whereas they were 8.1 ± 2.7 in stained samples. Results from Welch's t-test indicate significant difference between the two groups at a 95% confidence interval. Results for paired t-tests for each of the individual soft tissues also indicated significant improvement of contrast in all tissues after staining. Relatively large soft tissues in the middle ear such as the tympanic membrane and the tensor tympani muscle were impacted by staining more than smaller tissues such as the stapedial annular ligament. The increase in contrast with IKI solution confirms its potential application in automatic segmentation of the middle-ear soft tissues.




  17. Investigation of gamma knife image registration errors resulting from misalignment between the patient and the imaging axis.

    Cernica, George; Wang, Zhou; Malhotra, Harish; de Boer, Steven; Podgorsak, Matthew B


    The ability of Leksell GammaPlan to perform stereotactic space localizations with image sets where there is misalignment of the patient's head (stereotactic frame and fiducial apparatus) relative to the computed tomography (CT) scanner coordinate system was studied. Misalignment is sometimes necessary for patient comfort. Results equally apply to magnetic resonance imaging. Seven 0.5 mm diameter CT-visible spheres were rigidly mounted to a string tied tightly at each end to diagonally opposite posts attached to a Leksell stereotactic frame. A standard CT fiducial box was applied to the frame in the usual clinical manner. A baseline CT scan (1 mm slice thickness) was obtained with the fiducial box perfectly aligned with the scanner axis. After localization of the image set, the (x,y,z) coordinate of the center of each sphere was recorded. Repeat CT scans with varying fiducial box misalignments with the imaging axis were subsequently obtained. The mean difference between the base line and the respective coordinates in misaligned geometries was approximately 0.2 mm (sigma=0.2 mm), well within the accuracy of the image sets and the delivery of radiosurgery with the Gamma Knife.

  18. Imaging of patients with hippocampal sclerosis at 7 Tesla: initial results.

    Breyer, Tobias; Wanke, Isabel; Maderwald, Stefan; Woermann, Friedrich G; Kraff, Oliver; Theysohn, Jens M; Ebner, Alois; Forsting, Michael; Ladd, Mark E; Schlamann, Marc


    Focal epilepsies potentially can be cured by neurosurgery; other treatment options usually remain symptomatic. High-resolution magnetic resonance (MR) imaging is the central imaging strategy in the evaluation of focal epilepsy. The most common substrate of temporal epilepsies is hippocampal sclerosis (HS), which cannot always be sufficiently characterized with current MR field strengths. Therefore, the purpose of our study was to demonstrate the feasibility of high-resolution MR imaging at 7 Tesla in patients with focal epilepsy resulting from a HS and to improve image resolution at 7 Tesla in patients with HS. Six patients with known HS were investigated with T1-, T2-, T2(*)-, and fluid-attenuated inversion recovery-weighted sequences at 7 Tesla with an eight-channel transmit-receive head coil. Total imaging time did not exceed 90 minutes per patient. High-resolution imaging at 7 Tesla is feasible and reveals high resolution of intrahippocampal structures in vivo. HS was confirmed in all patients. The maximum non-interpolated in-plane resolution reached 0.2 x 0.2 mm(2) in T2(*)-weighted images. The increased susceptibility effects at 7 Tesla revealed identification of intrahippocampal structures in more detail than at 1.5 Tesla, but otherwise led to stronger artifacts. Imaging revealed regional differences in hippocampal atrophy between patients. The scan volume was limited because of specific absorption rate restrictions, scanning time was reasonable. High-resolution imaging at 7 Tesla is promising in presurgical epilepsy imaging. "New" contrasts may further improve detection of even very small intrahippocampal structural changes. Therefore, further investigations will be necessary to demonstrate the potential benefit for presurgical selection of patients with various lesion patterns in mesial temporal epilepsies resulting from a unilateral HS. Copyright 2010 AUR. Published by Elsevier Inc. All rights reserved.

  19. Illusory vowels resulting from perceptual continuity: a functional magnetic resonance imaging study.

    Heinrich, Antje; Carlyon, Robert P; Davis, Matthew H; Johnsrude, Ingrid S


    We used functional magnetic resonance imaging to study the neural processing of vowels whose perception depends on the continuity illusion. Participants heard sequences of two-formant vowels under a number of listening conditions. In the "vowel conditions," both formants were always present simultaneously and the stimuli were perceived as speech-like. Contrasted with a range of nonspeech sounds, these vowels elicited activity in the posterior middle temporal gyrus (MTG) and superior temporal sulcus (STS). When the two formants alternated in time, the "speech-likeness" of the sounds was reduced. It could be partially restored by filling the silent gaps in each formant with bands of noise (the "Illusion" condition) because the noise induced an illusion of continuity in each formant region, causing the two formants to be perceived as simultaneous. However, this manipulation was only effective at low formant-to-noise ratios (FNRs). When the FNR was increased, the illusion broke down (the "illusion-break" condition). Activation in vowel-sensitive regions of the MTG was greater in the illusion than in the illusion-break condition, consistent with the perception of Illusion stimuli as vowels. Activity in Heschl's gyri (HG), the approximate location of the primary auditory cortex, showed the opposite pattern, and may depend instead on the number of perceptual onsets in a sound. Our results demonstrate that speech-sensitive regions of the MTG are sensitive not to the physical characteristics of the stimulus but to the perception of the stimulus as speech, and also provide an anatomically distinct, objective physiological correlate of the continuity illusion in human listeners.

  20. High-field MR imaging in pediatric congenital heart disease: Initial results

    Nguyen, Kim-Lien [David Geffen School of Medicine at UCLA, Division of Cardiology, VA Greater Los Angeles Healthcare System, Los Angeles, CA (United States); Khan, Sarah N.; Moriarty, John M.; Mohajer, Kiyarash; Renella, Pierangelo; Boechat, M.I.; Finn, J.P. [University of California at Los Angeles, Department of Radiological Sciences, Los Angeles, CA (United States); Satou, Gary [David Geffen School of Medicine at UCLA, Division of Pediatric Cardiology, Los Angeles, CA (United States); Ayad, Ihab; Patel, Swati [David Geffen School of Medicine at UCLA, Department of Anesthesia, Los Angeles, CA (United States)


    Comprehensive assessment of pediatric congenital heart disease (CHD) at any field strength mandates evaluation of both vascular and dynamic cardiac anatomy for which diagnostic quality contrast-enhanced magnetic resonance angiography (CEMRA) and cardiac cine are crucial. To determine whether high-resolution (HR) CEMRA and steady-state free precession (SSFP) cine can be performed reliably at 3.0 T in children with CHD and to compare the image quality to similar techniques performed at 1.5 T. Twenty-eight patients with a median age of 5 months and average weight 9.0 ± 7.8 kg with suspected or known CHD were evaluated at 3.0 T. SSFP cine (n = 86 series) and HR-CEMRA (n = 414 named vascular segments) were performed and images were scored for image quality and artifacts. The findings were compared to those of 28 patients with CHD of similar weight who were evaluated at 1.5 T. Overall image quality on HR-CEMRA was rated as excellent or good in 96% (397/414) of vascular segments at 3.0 T (k = 0.49) and in 94% (349/371) of vascular segments at 1.5 T (k = 0.36). Overall image quality of SSFP was rated excellent or good in 91% (78/86) of cine series at 3.0 T (k = 0.55) and in 81% (87/108) at 1.5 T (k = 0.47). Off-resonance artifact was common at both field strengths, varied over the cardiac cycle and was more prevalent at 3.0 T. At 3.0 T, off-resonance dark band artifact on SSFP cine was absent in 3% (3/86), mild in 69% (59/86), moderate in 27% (23/86) and severe in 1% (1/86) of images; at 1.5 T, dark band artifact was absent in 16% (17/108), mild in 69% (75/108), moderate in 12% (13/108) and severe in 3% (3/108) of cine images. The signal-to-noise ratio and contrast-to-noise ratio of both SSFP cine and HR-CEMRA images were significantly higher at 3.0 T than at 1.5 T (P < 0.001). Signal-to-noise ratio and contrast-to-noise ratio of high-resolution contrast-enhanced magnetic resonance angiography and SSFP cine were higher at 3.0 T than at 1.5 T. Artifacts on SSFP cine were

  1. Computation of the ensemble channelized Hotelling observer signal-to-noise ratio for ordered-subset image reconstruction using noisy data

    Soares, Edward J.; Gifford, Howard C.; Glick, Stephen J.


    We investigated the estimation of the ensemble channelized Hotelling observer (CHO) signal-to-noise ratio (SNR) for ordered-subset (OS) image reconstruction using noisy projection data. Previously, we computed the ensemble CHO SNR using a method for approximating the channelized covariance of OS reconstruction, which requires knowledge of the noise-free projection data. Here, we use a "plug-in" approach, in which noisy data is used in place of the noise-free data in the aforementioned channelized covariance approximation. Additionally, we evaluated the use of smoothing of the noisy projections before use in the covariance approximation. Additionally, we evaluated the use of smoothing of the noisy projections before use in the covariance calculation. The task was detection of a 10% contrast Gaussian signal within a slice of the MCAT phantom. Simulated projections of the MCAT phantom were scaled and Poisson noise was added to create 100 noisy signal-absent data sets. Simulated projections of the scaled signal were then added to the noisy background projections to create 100 noisy signal-present data set. These noisy data sets were then used to generate 100 estimates of the ensemble CHO SNR for reconstructions at various iterates. For comparison purposes, the same calculation was repeated with the noise-free data. The results, reported as plots of the average CHO SNR generated in this fashion, along with 95% confidence intervals, demonstrate that this approach works very well, and would allow optimization of imaging systems and reconstruction methods using a more accurate object model (i.e., real patient data).

  2. Principal component analysis with pre-normalization improves the signal-to-noise ratio and image quality in positron emission tomography studies of amyloid deposits in Alzheimer's disease

    Razifar, Pasha [Molecular Imaging and CT Research, GE Healthcare, WI 53188, Waukesha (United States); Engler, Henry [Department of Medical Science, Uppsala University, SE-751 85 Uppsala (Sweden); Blomquist, Gunnar [Department of Oncology, Radiology and Clinical Immunology, Uppsala University, SE-751 85 Uppsala (Sweden); Ringheim, Anna; Estrada, Sergio [Uppsala Imanet AB, GE Healthcare, Box 967, SE-751 09, Uppsala (Sweden); Laangstroem, Bengt [Department of Biochemistry and Organic Chemistry, Uppsala University, SE-751 24 Uppsala (Sweden); Bergstroem, Mats [Department of Pharmaceutical Biosciences, Uppsala University, SE-751 24 Uppsala (Sweden)


    This study introduces a new approach for the application of principal component analysis (PCA) with pre-normalization on dynamic positron emission tomography (PET) images. These images are generated using the amyloid imaging agent N-methyl [{sup 11}C]2-(4'-methylaminophenyl)-6-hydroxy-benzothiazole ([{sup 11}C]PIB) in patients with Alzheimer's disease (AD) and healthy volunteers (HVs). The aim was to introduce a method which, by using the whole dataset and without assuming a specific kinetic model, could generate images with improved signal-to-noise and detect, extract and illustrate changes in kinetic behavior between different regions in the brain. Eight AD patients and eight HVs from a previously published study with [{sup 11}C]PIB were used. The approach includes enhancement of brain regions where the kinetics of the radiotracer are different from what is seen in the reference region, pre-normalization for differences in noise levels and removal of negative values. This is followed by slice-wise application of PCA (SW-PCA) on the dynamic PET images. Results obtained using the new approach were compared with results obtained using reference Patlak and summed images. The new approach generated images with good quality in which cortical brain regions in AD patients showed high uptake, compared to cerebellum and white matter. Cortical structures in HVs showed low uptake as expected and in good agreement with data generated using kinetic modeling. The introduced approach generated images with enhanced contrast and improved signal-to-noise ratio (SNR) and discrimination power (DP) compared to summed images and parametric images. This method is expected to be an important clinical tool in the diagnosis and differential diagnosis of dementia.

  3. Orientale and South Pole-Aitken basins on the Moon: Preliminary Galileo imaging results

    Head, J.; Fischer, E.; Murchie, S.; Pieters, C.; Plutchak, J.; Sunshine, J.; Belton, M.; Carr, M.; Chapman, C.; Davies, M.

    During the Earth-Moon flyby the Galileo Solid State Imaging System obtained new information on the landscape and physical geology of the Moon. Multicolor Galileo images of the Moon reveal variations in color properties of the lunar surface. Using returned lunar samples as a key, the color differences can be interpreted in terms of variations in the mineral makeup of the lunar rocks and soil. The combined results of Apollo landings and multicolor images from Galileo allow extrapolation of surface composition to areas distant from the landing sites, including the far side invisible from Earth.

  4. First X-ray fluorescence CT experimental results at the SSRF X-ray imaging beamline

    DENG Biao; YANG Qun; XIE Hong-Lan; DU Guo-Hao; XIAO Wi-Qiao


    X-ray fluorescence CT is a non-destructive technique for detecting elemental composition and distribution inside a specimen. In this paper, the first experimental results of X-ray fluorescence CT obtained at the SSRF X-ray imaging beamline (BL13W1) are described. The test samples were investigated and the 2D elemental image was reconstructed using a filtered back-projection algorithm. In the sample the element Cd was observed. Up to now, the X-ray fluorescence CT could be carried out at the SSRF X-ray imaging beamline.

  5. 结合最大方差比准则和PCNN模型的图像分割%Image segmentation with PCNN model and maximum of variance ratio

    辛国江; 邹北骥; 李建锋; 陈再良; 蔡美玲


    脉冲耦合神经网络(PCNN)模型在图像分割方面有着很好的应用.在各项参数确定的情况下,其分割结果的好坏取决于循环迭代次数的多少,而PCNN模型自身无法实现迭代次数的自动判定.为此提出一种结合最大方差比准则的PCNN迭代次数自动判定算法,用于实现图像的自动分割.算法利用最大方差比准则找到图像的最优分割界限,确定PCNN的迭代次数,获得最优图像分割结果,然后利用最大香农熵准则验证分割结果.实验表明:提出的算法实现了PCNN迭代次数的自动判定,提高了PCNN的迭代速度,运行效率优于基于2D-OTSU和基于交叉熵的自动分割算法,图像分割效果良好.%The Pulse Coupled Neural Network (FCNN) model is very suitable for image segmentation. With given parameters, the results of segmentation are determined only by the times of iteration. However, the PCNN model itself cannot automatically discover the optimal iteration times. Therefore, an algorithm based on the maximization of variance ratio criteria is proposed to solve this problem. The algorithm can automatically discover the best iteration times by applying the maximization of variance ratio criteria, and get the best segmentation results. Eventually, the Shannon entropy rule is used to check the segmentation results. The experimental results show that the algorithm can automatically discover the optimal iteration times, the segmentation results are satisfactory, and it improves the speed of PCNN iteration, and it is also more efficient than the automatic segmentation algorithm based 2D-OTSU and cross-entropy.

  6. Savanna grass nitrogen to phosphorous ratio estimation using field spectroscopy and the potential for estimation with imaging spectroscopy

    Ramoelo, A.; Skidmore, A.K.; Schlerf, M.; Heitkonig, I.M.A.; Mathieu, R.; Cho, M.A.


    Determining the foliar N:P ratio provides a tool for understanding nutrient limitation on plant production and consequently for the feeding patterns of herbivores. In order to understand the nutrient limitation at landscape scale, remote sensing techniques offer that opportunity. The objective of

  7. Variance Owing to Observer, Repeat Imaging, and Fundus Camera Type on Cup-to-disc Ratio Estimates by Stereo Planimetry

    Kwon, Young H.; Adix, Michael; Zimmerman, M. Bridget; Piette, Scott; Greenlee, Emily C.; Alward, Wallace L. M.; Abramoff, M.D.


    Objective: To determine and compare variance components in linear cup-to-disc ratio (LCDR) estimates by computer-assisted planimetry by human experts, and automated machine algorithm (digital automated planimetry). Design: Prospective case series for evaluation of planimetry. Participants: F

  8. Aid in the detection of myocardial perfusion abnormality utilizing SPECT atlas and images registration: preliminary results

    Padua, Rodrigo Donizete Santana de [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Faculdade de Medicina. Div. de Cardiologia]. E-mail:; Oliveira, Lucas Ferrari de [Universidade Federal de Pelotas (UFPel), RS (Brazil). Inst. de Fisica e Matematica. Dept. de Tecnologia da Informacao; Marques, Paulo Mazzoncini de Azevedo [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Faculdade de Medicina. Centro de Ciencias das Imagens e Fisica Medica; Groote, Jean-Jacques Georges Soares de [Instituto de Ensino Superior COC, Ribeirao Preto, SP (Brazil). Lab. of Artifical Intelligence and Applications; Castro, Adelson Antonio de [Universidade de Sao Paulo (USP), Ribeirao Preto, SP, (Brazil). Faculdade de Medicina; Ana, Lauro Wichert [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Faculdade de Medicina. Centro de Ciencias das Imagens e Fisica Medica; Simoes, Marcus Vinicius [Universidade de Sao Paulo (USP), Ribeirao Preto, SP, (Brazil). Faculdade de Medicina. Divisao de Cardiologia


    To develop an atlas of myocardial perfusion scintigraphy and evaluating its applicability in computer-aided detection of myocardial perfusion defects in patients with ischemic heart disease. The atlas was created with rest-stress myocardial perfusion scintigraphic images of 20 patients of both genders with low probability of coronary artery disease and considered as normal by two experienced observers. Techniques of image registration and mathematical operations on images were utilized for obtaining template images depicting mean myocardial uptake and standard deviation for each gender and physiological condition. Myocardial perfusion scintigraphy images of one male and one female patient were aligned with the corresponding atlas template image, and voxels with myocardial uptake rates two standard deviations below the mean voxel value of the respective region in the atlas template image were highlighted on the tomographic sections and confirmed as perfusion defects by both observe. The present study demonstrated the creation of an atlas of myocardial perfusion scintigraphy with promising results of this tool as an aid in the detection of myocardial perfusion defects. However, further prospective validation with a more representative sample is recommended. (author)

  9. First imaging results from Apertif, a phased-array feed for WSRT

    Adams, Elizabeth A.; Adebahr, Björn; de Blok, Willem J. G.; Hess, Kelley M.; Hut, Boudewijn; Lucero, Danielle M.; Maccagni, Filippo; Morganti, Raffaella; Oosterloo, Tom; Staveley-Smith, Lister; van der Hulst, Thijs; Verheijen, Marc; Verstappen, Joris


    Apertif is a phased-array feed for the Westerbork Synthesis Radio Telescope (WSRT), increasing the field of view of the telescope by a factor of twenty-five. In 2017, three legacy surveys will commence: a shallow imaging survey, a medium-deep imaging survey, and a pulsars and fast transients survey. The medium-deep imaging survey will include coverage of the northern Herschel Atlas field, the CVn region, HetDex, and the Perseus-Pisces supercluster. The shallow imaging survey increases overlap with HetDex, has expanded coverage of the Perseus-Pisces supercluster, and includes part of the Zone of Avoidance. Both imaging surveys are coordinating with MaNGA and will have WEAVE follow-up. The imaging surveys will be done in full polarization over the frequency range 1130-1430 MHz, which corresponds to redshifts of z=0-0.256 for neutral hydrogen (HI). The spectral resolution is 12.2 kHz, or an HI velocity resolution of 2.6 km/s at z=0 and 3.2 km/s at z=0.256. The full resolution images will have a beam size of 15"x15"/sin(declination), and tapered data products (i.e., 30" resolution images) will also be available. The shallow survey will cover ~3500 square degrees with a four-sigma HI imaging sensitivity of 2.5x10^20 atoms cm^-2 (20 km/s linewidth) at the highest resolution and a continuum sensitivity of 15 uJy/beam (11 uJy/beam for polarization data). The current plan calls for the medium deep survey to cover 450 square degrees and provide an HI imaging sensitivity of 1.0x10^20 atoms cm^-2 at the highest resolution and a continuum sensitivity of 6 uJy/beam, close to the confusion limit (4 uJy/beam for polarization data, not confusion limited). Up-to-date information on Apertif and the planned surveys can be found at: of the Apertif instrument is currently underway. Here we present first results from the image commissioning, including the detection of HI absorption plus continuum and HI imaging. These results highlight the data quality

  10. [The image noise effect on the results of Gamma knife dosimetry parameters test].

    Cheng, Xiaojun; Zhang, Conghua; Hu, Chuanpeng; Dai, Fuyou; Wei, Kunjie; Chu, Caifang


    In order to analyze the image noise effect on the results of Gamma knife dosimetry parameter test, we tested the dosimetry parameters of the Gamma knives according to GBZ 168-2005. Radiological protection standards of X (gamma)-ray stereotactic radiosurgery for head treatment. Dose analysis software was applied to examine the testing film before and after image denoising, and SPSS 11.0 software was used for statistical analysis. The results showed that there was a significant difference in the results of the maximum deviation between radiation field size and its nominal value (t = 7.600, P Gamma knife dosimetry parameters, so as to cause deviations.

  11. Physical mechanism of the chaotic detection of the unknown frequency of weak harmonic signal and effects of damping ratio on the detection results

    Li Yue; Yang Bao-Jun; Deng Xiao-Ying; Jin Lei; Du Li-Zhi


    In the zero-order approximation, we use the perturbation method of parameter with small magnitude to prove that the harmonic frequency in the solution of the equation is close to that of the driving force when the chaotic system from Duffing-Holmes equation stays in the stable periodic state, which is the physical mechanism of the detection of the unknown frequency of weak harmonic signal using the chaotic theory. The result of the simulation experiment shows that the method proposed in this paper, by which one can determine the frequency of the stable system from the number of circulation change of the phase state directionally across a fixed phase state point (x, x) in fixed simulation time period, is successful. Analyzing the effects of the damping ratio on the chaotic detection result, one can see that for different frequency ranges it is necessary to carefully choose corresponding damping ratio α.

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

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


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

  13. First Results On The Imaging Capabilities Of A DROID Array In The UV/Visible

    Hijmering, R. A.; Verhoeve, P.; Martin, D. D. E.; Venn, R.


    Within the SCAM project of the European Space Agency the next step in the development of a cryogenic optical photon counting imaging spectrometer would be to increase the field of view using DROIDs (Distributed Read-Out Imaging Detector). We present the results of the first system test using an array of 60 360×33.5 μm2 DROIDs in a 3×20 format for optical photon detection. This is an increase in area by a factor of 5.5 compared to the successful S-Cam 3 detector. The responsivity of the DROID array tested is too low for actual use on the telescope. However the spatial resolution of ˜35 μm is just above the size of a virtual pixel and imaging capabilities of the array can be demonstrated. With increasing responsivity this will improve, yielding a DROID array which can be used as an astronomical optical photon counting imaging spectrometer.

  14. Imaging the crustal structure of the valley of Mexico and higher mode identification using H/V spectral ratio

    Rivet, D.; Campillo, M.; Sanchez-Sesma, F.; Singh, S. K.


    We reconstruct Rayleigh and Love waves from cross-correlations of ambient seismic noise recorded at 19 broad-band stations of the MesoAmerica Seismic Experiment (MASE) and Valley of Mexico Experiment (VMEX). The cross-correlations are computed over 2 years of noise records for the 8 MASE stations and over 1 year for the 11 VMEX stations. We use surface waves with sufficient signal-to-noise ratio to measure group velocity dispersion curves at period of 0.5 to 3 seconds. For paths within the soft quaternary sediments basin, the maximum energy is observed at velocity higher than expected for the fundamental mode. This observation suggests the importance of higher modes as the main vectors of energy in such complex structures. To perform a reliable inversion of the velocity structure beneath the valley, an identification of these dominants modes is required. To identify the modes of surface waves we use the spectral ratio of the horizontal components over the vertical component (H/V) measured on seismic coda. We compare the observed values with the theoretical H/V for the velocity model deduced from surface wave dispersion when assuming a particular mode. H/V ratio in the coda is computed under the hypothesis of equipartition of a diffuse field in a layered medium following Margerin et al. [2009] and Sánchez-Sesma et al. [2011]. We processed several events to ensure that the observed H/V is stable. The comparison of the modelled dispersion and H/V ratio allows for mode identification, and consequently to recover the velocity model of the structure. We conclude on the predominance of higher modes in our observations. The excitation of higher modes is key element of explanation for the long duration and amplification of the seismic signals observed in the Valley of Mexico.

  15. The impact of acquisition time of planar cardiac {sup 123}I-MIBG imaging on the late heart to mediastinum ratio

    Dimitriu-Leen, Aukelien C.; Veltman, Caroline E.; Bax, Jeroen J.; Scholte, Arthur J.H.A. [Leiden University Medical Center, Department of Cardiology, Leiden (Netherlands); Gimelli, Alessia [Fondazione Toscana/CNR Gabriele Monasterio, Pisa (Italy); Al Younis, Imad [VieCuri, Department of Nuclear Medicine, Venlo (Netherlands); Verberne, Hein J. [Academic Medical Center, Department of Nuclear Medicine, Amsterdam (Netherlands); Wolterbeek, Ron [Leiden University Medical Center, Department of Medical Statistics and Bio-informatics, Leiden (Netherlands); Zandbergen-Harlaar, Silvia [Leiden University Medical Center, Department of Nuclear Medicine, Leiden (Netherlands)


    The aim of this study was to investigate whether performing the late cardiac {sup 123}I-metaiodobenzylguanidine (MIBG) scan earlier than 4 h post-injection (p.i.) has relevant impact on the late heart to mediastinum ratio (H/M ratio) in patients with heart failure (HF). Forty-nine patients with HF (median left ventricular ejection fraction of 31 %, 51 % ischaemic HF) referred for cardiac {sup 123}I-MIBG scintigraphy were scanned at 15 min (early) p.i. and at 1, 2, 3 and 4 h (late) p.i. of {sup 123}I-MIBG. Late H/M ratios were calculated and evaluated using a linear mixed model with the mean late H/M ratio at 4 h p.i. as a reference. A difference in late H/M ratios of more than 0.10 between the different acquisition times in comparison with the late H/M ratio at 4 h p.i. was considered as clinically relevant. Statistically significant mean differences were observed between the late H/M ratios at 1, 2 and 3 h p.i. compared with the late H/M ratio at 4 h p.i. (0.09, 0.05 and 0.02, respectively). However, the mean differences did not exceed the cut-off value of 0.10. On an individual patient level, compared to the late H/M ratio at 4 h p.i., the late H/M ratios at 1, 2 and 3 h p.i. differed more than 0.10 in 24 (50 %), 9 (19 %) and 2 (4 %) patients, respectively. Variation in acquisition time of {sup 123}I-MIBG between 2 and 4 h p.i. does not lead to a clinically significant change in the late H/M ratio. An earlier acquisition time seems to be justified and may warrant a more time-efficient cardiac {sup 123}I-MIBG imaging protocol. (orig.)

  16. 3-D Tomographic Imaging of the Chicxulub Impact Crater: Preliminary Results From EW#0501

    Surendra, A. T.; Barton, P. J.; Vermeesch, P. M.; Morgan, J. V.; Warner, M. R.; Gulick, S. P.; Christeson, G. L.; Urrutia-Fucugauchi, J.; Rebolledo-Vieyra, M.; Melosh, H. J.; McDonald, M. A.; Goldin, T.; Mendoza, K.


    The Chicxulub impact structure provides a unique opportunity to investigate the sub-surface morphology of large craters on Earth and other planets. The structure of the crater interior is still poorly known and there is much uncertainty over the sequence of events by which these large craters form and the magnitude of the subsequent catastrophic environmental effects. In early 2005, a reflection-refraction survey aboard the R/V Maurice Ewing imaged the deep structure of the Chicxulub impact. We present wide-angle data collected by a 3-D grid of 50 ocean bottom seismometers (OBSs), 86 three-component land stations and a 6 km long hydrophone streamer. The OBS grid, designed to image the peak ring and underlying structure of the northwestern quadrant of the crater, recorded shots from several seismic profiles in various orientations. Many of these profiles extended past the crater rim imaging to the base of the crust. Travel-time picks from this dataset, combined with existing 1996 data, will be inverted using the JIVE3-D tomographic inversion program to create a fully 3-D velocity model of the crater interior. The interpretation of the velocity model will focus on the morphology of the peak ring and the central uplift, and the distribution of breccia and suevite (an impact related breccia/melt) in the centre of the crater. We will calculate the Poisson's ratio for different areas of the crater using both the P-wave velocity model and S-wave arrivals, including those from the 1996 land station data. Comparisons of these values with measurements on the Yaxcopoil-1 core taken from within the crater provide ground-truth for our tomographic model. The contrast in Poisson's ratio between areas of suevite and the surrounding rock further constrain the distribution of breccia and suevite.

  17. Hypoxic Prostate/Muscle PO{sub 2} Ratio Predicts for Outcome in Patients With Localized Prostate Cancer: Long-Term Results

    Turaka, Aruna [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA (United States); Buyyounouski, Mark K., E-mail: [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA (United States); Hanlon, Alexandra L. [School of Nursing, University of Pennsylvania, Philadelphia, PA (United States); Horwitz, Eric M. [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA (United States); Greenberg, Richard E. [Department of Surgery, Fox Chase Cancer Center, Philadelphia, PA (United States); Movsas, Benjamin [Department of Radiation Oncology, Henry Ford Hospital, Detroit, MI (United States)


    Purpose: To correlate tumor oxygenation status with long-term biochemical outcome after prostate brachytherapy. Methods and Materials: Custom-made Eppendorf PO{sub 2} microelectrodes were used to obtain PO{sub 2} measurements from the prostate (P), focused on positive biopsy locations, and normal muscle tissue (M), as a control. A total of 11,516 measurements were obtained in 57 men with localized prostate cancer immediately before prostate brachytherapy was given. The Eppendorf histograms provided the median PO{sub 2}, mean PO{sub 2}, and % <5 mm Hg or <10 mm Hg. Biochemical failure (BF) was defined using both the former American Society of Therapeutic Radiation Oncology (ASTRO) (three consecutive raises) and the current Phoenix (prostate-specific antigen nadir + 2 ng/mL) definitions. A Cox proportional hazards regression model evaluated the influence of hypoxia using the P/M mean PO{sub 2} ratio on BF. Results: With a median follow-up time of 8 years, 12 men had ASTRO BF and 8 had Phoenix BF. On multivariate analysis, P/M PO{sub 2} ratio <0.10 emerged as the only significant predictor of ASTRO BF (p = 0.043). Hormonal therapy (p = 0.015) and P/M PO{sub 2} ratio <0.10 (p = 0.046) emerged as the only independent predictors of the Phoenix BF. Kaplan-Meier freedom from BF for P/M ratio <0.10 vs. {>=}0.10 at 8 years for ASTRO BF was 46% vs. 78% (p = 0.03) and for the Phoenix BF was 66% vs. 83% (p = 0.02). Conclusions: Hypoxia in prostate cancer (low mean P/M PO{sub 2} ratio) significantly predicts for poor long-term biochemical outcome, suggesting that novel hypoxic strategies should be investigated.

  18. Online Learning a Binary Classifier for Improving Go ogle Image Search Results

    WAN Yu-Chai; LIU Xia-Bi; HAN Fei-Fei; TONG Kun-Qi; LIU Yu


    It is promising to improve web image search results through exploiting the results0 visual contents for learning a binary classifier which is used to refine the results0 relevance degrees to the given query. This paper proposes an algorithm framework as a solution to this problem and investigates the key issue of training data selection under the framework. The training data selection process is divided into two stages: initial selection for triggering the classifier learning and dynamic selection in the iterations of classifier learning. We investigate two main ways of initial training data selection, including clustering based and ranking based, and compare automatic training data selection schemes with manual manner. Furthermore, support vector machines and the max-min pseudo-probability (MMP) based Bayesian classifier are employed to support image classification, respectively. By varying these factors in the framework, we implement eight algorithms and tested them on keyword based image search results from Google search engine. The experimental results confirm that how to select the training data from noisy search results is really a key issue in the problem considered in this paper and show that the proposed algorithm is effective to improve Google search results, especially at top ranks, thus is helpful to reduce the user labor in finding the desired images by browsing the ranking in depth. Even so, it is still worth meditative to make automatic training data selection scheme better towards perfect human annotation.

  19. Sentinel-2A image quality commissioning phase final results: geometric calibration and performances

    Languille, F.; Gaudel, A.; Dechoz, C.; Greslou, D.; de Lussy, F.; Trémas, T.; Poulain, V.; Massera, S.


    In the frame of the Copernicus program of the European Commission, Sentinel-2 offers multispectral high-spatial-resolution optical images over global terrestrial surfaces. In cooperation with ESA, the Centre National d'Etudes Spatiales (CNES) is in charge of the image quality of the project, and so ensures the CAL/VAL commissioning phase during the months following the launch. Sentinel-2 is a constellation of 2 satellites on a polar sun-synchronous orbit with a revisit time of 5 days (with both satellites), a high field of view - 290km, 13 spectral bands in visible and shortwave infrared, and high spatial resolution - 10m, 20m and 60m. The Sentinel-2 mission offers a global coverage over terrestrial surfaces. The satellites acquire systematically terrestrial surfaces under the same viewing conditions in order to have temporal images stacks. The first satellite was launched in June 2015. Following the launch, the CAL/VAL commissioning phase is then lasting during 6 months for geometrical calibration. This paper will point on observations and results seen on Sentinel-2 images during commissioning phase. It will provide explanations about Sentinel-2 products delivered with geometric corrections. This paper will detail calibration sites, and the methods used for geometrical parameters calibration and will present linked results. The following topics will be presented: viewing frames orientation assessment, focal plane mapping for all spectral bands, results on geolocation assessment, and multispectral registration. There is a systematic images recalibration over a same reference which is a set of S2 images produced during the 6 months of CAL/VAL. This set of images will be presented as well as the geolocation performance and the multitemporal performance after refining over this ground reference.

  20. Iterative reconstruction techniques for computed tomography part 2: initial results in dose reduction and image quality

    Willemink, Martin J.; Leiner, Tim; Jong, Pim A. de; Nievelstein, Rutger A.J.; Schilham, Arnold M.R. [Utrecht University Medical Center, Department of Radiology, P.O. Box 85500, Utrecht (Netherlands); Heer, Linda M. de [Cardiothoracic Surgery, Utrecht (Netherlands); Budde, Ricardo P.J. [Utrecht University Medical Center, Department of Radiology, P.O. Box 85500, Utrecht (Netherlands); Gelre Hospital, Department of Radiology, Apeldoorn (Netherlands)


    To present the results of a systematic literature search aimed at determining to what extent the radiation dose can be reduced with iterative reconstruction (IR) for cardiopulmonary and body imaging with computed tomography (CT) in the clinical setting and what the effects on image quality are with IR versus filtered back-projection (FBP) and to provide recommendations for future research on IR. We searched Medline and Embase from January 2006 to January 2012 and included original research papers concerning IR for CT. The systematic search yielded 380 articles. Forty-nine relevant studies were included. These studies concerned: the chest(n = 26), abdomen(n = 16), both chest and abdomen(n = 1), head(n = 4), spine(n = 1), and no specific area (n = 1). IR reduced noise and artefacts, and it improved subjective and objective image quality compared to FBP at the same dose. Conversely, low-dose IR and normal-dose FBP showed similar noise, artefacts, and subjective and objective image quality. Reported dose reductions ranged from 23 to 76 % compared to locally used default FBP settings. However, IR has not yet been investigated for ultra-low-dose acquisitions with clinical diagnosis and accuracy as endpoints. Benefits of IR include improved subjective and objective image quality as well as radiation dose reduction while preserving image quality. Future studies need to address the value of IR in ultra-low-dose CT with clinically relevant endpoints. (orig.)

  1. Assessing agreement between preclinical magnetic resonance imaging and histology: An evaluation of their image qualities and quantitative results.

    Elschner, Cindy; Korn, Paula; Hauptstock, Maria; Schulz, Matthias C; Range, Ursula; Jünger, Diana; Scheler, Ulrich


    One consequence of demographic change is the increasing demand for biocompatible materials for use in implants and prostheses. This is accompanied by a growing number of experimental animals because the interactions between new biomaterials and its host tissue have to be investigated. To evaluate novel materials and engineered tissues the use of non-destructive imaging modalities have been identified as a strategic priority. This provides the opportunity for studying interactions repeatedly with individual animals, along with the advantages of reduced biological variability and decreased number of laboratory animals. However, histological techniques are still the golden standard in preclinical biomaterial research. The present article demonstrates a detailed method comparison between histology and magnetic resonance imaging. This includes the presentation of their image qualities as well as the detailed statistical analysis for assessing agreement between quantitative measures. Exemplarily, the bony ingrowth of tissue engineered bone substitutes for treatment of a cleft-like maxillary bone defect has been evaluated. By using a graphical concordance analysis the mean difference between MRI results and histomorphometrical measures has been examined. The analysis revealed a slightly but significant bias in the case of the bone volume [Formula: see text] and a clearly significant deviation for the remaining defect width [Formula: see text] But the study although showed a considerable effect of the analyzed section position to the quantitative result. It could be proven, that the bias of the data sets was less originated due to the imaging modalities, but mainly on the evaluation of different slice positions. The article demonstrated that method comparisons not always need the use of an independent animal study, additionally.

  2. Added value of 80 kVp images to averaged 120 kVp images in the detection of hepatocellular carcinomas in liver transplantation candidates using dual-source dual-energy MDCT: Results of JAFROC analysis

    Park, Ji Hoon [Department of Radiology, Seoul National University Hospital (Korea, Republic of); Kim, Se Hyung, E-mail: [Department of Radiology, Seoul National University Hospital (Korea, Republic of); Institute of Radiation Medicine, Seoul National University Hospital (Korea, Republic of); Park, Hee Sun [Department of Radiology, Konkuk University Hospital (Korea, Republic of); Kim, Gi Hyeon [Department of Radiology, Chung-Ang University Hospital (Korea, Republic of); Lee, Jae Young; Lee, Jeong Min; Han, Joon Koo; Choi, Byung Ihn [Department of Radiology, Seoul National University Hospital (Korea, Republic of); The Institute of Radiation Medicine, Seoul National University Hospital (Korea, Republic of)


    Background: To assess the added value of 80 kVp images to weighted average 120 kVp images for detecting hepatocellular carcinomas (HCCs) using dual-source, dual-energy MDCT. Materials and methods: Forty-one HCCs in 42 patients who underwent liver transplantation (LT) were included. All patients underwent quadruple-phase CT using a 64-row dual-source, dual-energy MDCT with 80 kVp and 140 kVp. For 120 kVp, a linear blending ratio of 0.3 was chosen. Interval reviews for both simulated 120 kVp images without and with pure 80 kVp data were performed independently by two radiologists. They detected HCCs using a 4-point confidence scale. Tumor-to-liver contrast-to-noise ratio (CNR) was calculated and compared between the 80 kVp and simulated 120 kVp images. The additional diagnostic value of 80 kVp images was evaluated by jackknife alternative free-response receiver-operating characteristic (JAFROC) analysis. Results: There were 41 HCCs on pathology and 37 of the 41 HCCs were depicted on CT scan. The mean CNR of the 37 HCCs in late arterial and portal-phase images was significantly better in the 80 kVp images than in 120 kVp images. The average JAFROC figure of merit, however, was not significantly improved when 80 kVp was added. Furthermore, the number of false-positives was significantly increased in reader 1 when adding 80 kVp data. Conclusion: The addition of 80 kVp CT images to simulated 120 kVp images did not significantly improve the detection of HCCs despite of the significantly better CNR of 80 kVp images.

  3. Co-Registration of Terrestrial and Uav-Based Images - Experimental Results

    Gerke, M.; Nex, F.; Jende, P.


    -filter. Results show that in more challenging situations, in this case for data captured from different platforms at different days most approaches do not perform well. Wallis-filtering emerged to be most helpful especially for the SIFT approach. The commercial software pix4dmapper succeeds in overall bundle adjustment only for some configurations, and especially not for the entire image block provided.


    M. Gerke


    Wallis-filter. Results show that in more challenging situations, in this case for data captured from different platforms at different days most approaches do not perform well. Wallis-filtering emerged to be most helpful especially for the SIFT approach. The commercial software pix4dmapper succeeds in overall bundle adjustment only for some configurations, and especially not for the entire image block provided.

  5. Recent results with a combined gamma-ray and neutron imaging detector

    Soundara-Pandian, L.; Whitney, C. M.; Johnson, E. B.; Vinci, R.; Glodo, J.; Christian, J. F.; Gervais, J.; Vogel, Sam; Nagarkar, E.; Robertson, F.; Squillante, M. S.; Waer, P.; Squillante, M. R.


    Numerous instruments have been developed for performing gamma-ray imaging and neutron imaging for research, nondestructive testing, medicine and national security. However, none are capable of imaging gamma-rays and neutrons simultaneously while also discriminating gamma-rays from the neutron. This paper will describe recent experimental results obtained using a gamma/neutron camera based on Cs2LiYCl6:Ce (CLYC) scintillation crystals, which can discriminate gamma-rays from neutrons. The ability to do this while also having good energy resolution provides a powerful capability for detecting and identifying shielded special nuclear materials for security applications. Also discussed are results obtained using a LaBr3 scintillation crystal.

  6. Nexus of Health and Development: Modelling Crude Birth Rate and Maternal Mortality Ratio Using Nighttime Satellite Images

    Koel Roychowdhury


    Full Text Available Health and development are intricately related. Although India has made significant progress in the last few decades in the health sector and overall growth in GDP, there are still large regional differences in both health and development. The main objective of this paper is to develop techniques for the prediction of health indicators for all the districts of India and examine the correlations between health and development. The level of electrification and district domestic product (DDP are considered as two fundamental indicators of development in this research. These data, along with health metrics and the information from two nighttime satellite images, were used to propose the models. These successfully predicted the health indicators with less than a 7%–10% error. The chosen health metrics, such as crude birth rate (CBR and maternal mortality rate (MMR, were mapped for the whole country at the district level. These metrics showed very strong correlation with development indicators (correlation coefficients ranging from 0.92 to 0.99 at the 99% confidence interval. This is the first attempt to use Visible Infrared Imaging Radiometer Suite (VIIRS (satellite imagery in a socio-economic study. This paper endorses the observation that areas with a higher DDP and level of electrification have overall better health conditions.

  7. Image tuning techniques for enhancing the performance of pure permanent magnet undulators with small gap/period ratios

    Tatchyn, R. [Stanford Univ., CA (United States)


    The on-axis field of a small-gap undulator constricted out of pure permanent magnet (PM) blocks arranged in an alternating-dipole (i.e., 2 dipoles/period) array can be substantially varied by positioning monolithic permeable plates above and below the undulator jaws. This simple technique, which can be used to control the 1st harmonic energy in conventional synchrotron radiation (SR) or Free Electron Laser (FEL) applications requiring sub-octave tuning, can also be shown to suppress magnetic inhomogeneities that can contribute to the undulator`s on-axis field errors. If a standard 4 block/period Halbach undulator, composed of PM blocks with square cross sections, is rearranged into an alternating-dipole array with the same period, the peak field that can be generated with superimposed image plates can substantially exceed that of the pure-PM Halbach array. This design technique, which can be viewed as intermediate between the {open_quotes}pure-PM{close_quotes} and standard {open_quotes}hybrid/PM{close_quotes} configurations, provides a potentially cost-effective method of enhancing the performance of small-gap, pure-PM insertion devices. In this paper we report on the analysis and recent characterization of pure-PM undulator structures with superimposed image plates, and discuss possible applications to FEL research.

  8. Research on the classification result and accuracy of building windows in high resolution satellite images: take the typical rural buildings in Guangxi, China, as an example

    Li, Baishou; Gao, Yujiu


    The information extracted from the high spatial resolution remote sensing images has become one of the important data sources of the GIS large scale spatial database updating. The realization of the building information monitoring using the high resolution remote sensing, building small scale information extracting and its quality analyzing has become an important precondition for the applying of the high-resolution satellite image information, because of the large amount of regional high spatial resolution satellite image data. In this paper, a clustering segmentation classification evaluation method for the high resolution satellite images of the typical rural buildings is proposed based on the traditional KMeans clustering algorithm. The factors of separability and building density were used for describing image classification characteristics of clustering window. The sensitivity of the factors influenced the clustering result was studied from the perspective of the separability between high image itself target and background spectrum. This study showed that the number of the sample contents is the important influencing factor to the clustering accuracy and performance, the pixel ratio of the objects in images and the separation factor can be used to determine the specific impact of cluster-window subsets on the clustering accuracy, and the count of window target pixels (Nw) does not alone affect clustering accuracy. The result can provide effective research reference for the quality assessment of the segmentation and classification of high spatial resolution remote sensing images.

  9. Latest Results from the DODO Survey: Imaging Planets around White Dwarfs

    Hogan, Emma; Burleigh, Matt R.; Clarke, Fraser J.


    The aim of the Degenerate Objects around Degenerate Objects (DODO) survey is to search for very low mass brown dwarfs and extrasolar planets in wide orbits around white dwarfs via direct imaging. The direct detection of such companions would allow the spectroscopic investigation of objects with temperatures lower (DODO survey has the ability to directly image planets in post-main sequence analogues of these systems. These proceedings present the latest results of our multi-epoch J band common proper motion survey of nearby white dwarfs.

  10. Fast Blood Vector Velocity Imaging: Simulations and Preliminary In Vivo Results

    Udesen, Jesper; Gran, Fredrik; Hansen, Kristoffer Lindskov


    for each pulse emission. 2) The transmitted pulse consists of a 13 bit Barker code which is transmitted simultaneously from each transducer element. 3) The 2-D vector velocity of the blood is found using 2-D speckle tracking between segments in consecutive speckle images. III Results: The method was tested...... rate can be significantly increased, and the full 2-D vector velocity of the blood can be estimated. II Method: The method presented in this paper uses three techniques: 1) The ultrasound is not focused during the transmit of the ultrasound signals, and a full speckle image of the blood can be acquired...


    Giovanni Francesco Spatola


    Full Text Available The use of image analysis methods has allowed us to obtain more reliable and repro-ducible immunohistochemistry (IHC results. Wider use of such approaches and sim-plification of software allowing a colorimetric study has meant that these methods are available to everyone, and made it possible to standardize the technique by a reliable systems score. Moreover, the recent introduction of multispectral image acquisition systems methods has further refined these techniques, minimizing artefacts and eas-ing the evaluation of the data by the observer.

  12. Focal overlap gating in velocity map imaging to achieve high signal-to-noise ratio in photo-ion pump-probe experiments

    Shivaram, Niranjan; Champenois, Elio G.; Cryan, James P.; Wright, Travis; Wingard, Taylor; Belkacem, Ali


    We demonstrate a technique in velocity map imaging (VMI) that allows spatial gating of the laser focal overlap region in time resolved pump-probe experiments. This significantly enhances signal-to-noise ratio by eliminating background signal arising outside the region of spatial overlap of pump and probe beams. This enhancement is achieved by tilting the laser beams with respect to the surface of the VMI electrodes which creates a gradient in flight time for particles born at different points along the beam. By suitably pulsing our microchannel plate detector, we can select particles born only where the laser beams overlap. This spatial gating in velocity map imaging can benefit nearly all photo-ion pump-probe VMI experiments especially when extreme-ultraviolet light or X-rays are involved which produce large background signals on their own.

  13. Focal overlap gating in velocity map imaging to achieve high signal-to-noise ratio in photo-ion pump-probe experiments

    Shivaram, Niranjan; Cryan, James P; Wright, Travis W; Wingard, Taylor; Belkacem, Ali


    We demonstrate a new technique in velocity map imaging (VMI) that allows spatial gating of the laser focal overlap region in time resolved pump-probe experiments. This significantly enhances signal-to-noise ratio by eliminating background signal arising outside the region of spatial overlap of pump and probe beams. This enhancement is achieved by tilting the laser beams with respect to the surface of the VMI electrodes which creates a gradient in flight time for particles born at different points along the beam. By suitably pulsing our microchannel plate detector, we can select particles born only where the laser beams overlap. This spatial gating in velocity map imaging can benefit nearly all photoion pump-probe VMI experiments especially when extreme-ultraviolet (XUV) light or X-rays are involved which produce large background signals on their own.

  14. Experience of applying the results of investigations into controlling lines of the salt ratio between the salt and pure sections of high-pressure drum boilers

    Fedorov, A. I.


    Layouts of the connection of the salt ratio lines (SRLs) existing in domestic boiler building are analyzed and the main causes of their low operational efficiency are shown. The results of investigation of hydraulics and the salt mode of an internal boiler layout with the SRL of the TPE-208 boiler are presented. Recommendations on designing the SRL in internal boiler layouts of high-pressure drum boilers, which make it possible to increase the reliability of boilers and to decrease the annual consumption of phosphates, are developed.

  15. Results Of The IMAGES Project 1986-1989; Facts And Fallacies

    Ottes, Fenno P.; de Valk, Jan P.; Lodder, Herman; Stut, W. J.; van der Horst-Bruinsma, I.; Hofland, Paul L.; van Poppel, Bas M.; Ter Haar Romeny, Bart M.; Bakker, Albert R.


    A concise overview is presented on the results of the total IMAGIS (IMAGe Information System) research as carried out by BAZIS. This paper is intended as a continuation of the IMAGIS presentation at the 'Dutch PACS session' during the SPIE Medical Imaging H Conference 1988. That session was jointly organized by the Utrecht University Hospital (AZU), BAZIS and Philips Medical Systems, the partners within the Dutch PACS project. The HIS-PACS coupling/integration project has resulted in a HIS-PACS coupling that is used to transfer data from the BAZIS HIS to the prototype Philips PACS. The modelling and simulation project has resulted in a modelling and simulation package (MIRACLES), which has been used to suggest performance improvements of existing and future PACS's. To support the technology assessment project a PC program has been developed that calculates the financial consequences of the introduction of a PACS (CAPACITY). The diagnostic image quality evaluation project has provided research protocols and a software package (FEASIBLE) that have been used as an aid to execute observer performance studies. A software package (FRACTALS) has been developed so that a standard computer (113M RT PC) can be used as a simple image workstation for radiological research. Furthermore, a number of general issues concerning the development, the acceptance and the introduction of PACS are discussed.

  16. T2-weighted four dimensional magnetic resonance imaging with result-driven phase sorting

    Liu, Yilin; Yin, Fang-Fang; Cai, Jing, E-mail: [Medical Physics Graduate Program, Duke University, Durham, North Carolina 27710 and Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina 27710 (United States); Czito, Brian G. [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina 27710 (United States); Bashir, Mustafa R. [Department of Radiology, Duke University Medical Center, Durham, North Carolina 27710 (United States)


    Purpose: T2-weighted MRI provides excellent tumor-to-tissue contrast for target volume delineation in radiation therapy treatment planning. This study aims at developing a novel T2-weighted retrospective four dimensional magnetic resonance imaging (4D-MRI) phase sorting technique for imaging organ/tumor respiratory motion. Methods: A 2D fast T2-weighted half-Fourier acquisition single-shot turbo spin-echo MR sequence was used for image acquisition of 4D-MRI, with a frame rate of 2–3 frames/s. Respiratory motion was measured using an external breathing monitoring device. A phase sorting method was developed to sort the images by their corresponding respiratory phases. Besides, a result-driven strategy was applied to effectively utilize redundant images in the case when multiple images were allocated to a bin. This strategy, selecting the image with minimal amplitude error, will generate the most representative 4D-MRI. Since we are using a different image acquisition mode for 4D imaging (the sequential image acquisition scheme) with the conventionally used cine or helical image acquisition scheme, the 4D dataset sufficient condition was not obviously and directly predictable. An important challenge of the proposed technique was to determine the number of repeated scans (N{sub R}) required to obtain sufficient phase information at each slice position. To tackle this challenge, the authors first conducted computer simulations using real-time position management respiratory signals of the 29 cancer patients under an IRB-approved retrospective study to derive the relationships between N{sub R} and the following factors: number of slices (N{sub S}), number of 4D-MRI respiratory bins (N{sub B}), and starting phase at image acquisition (P{sub 0}). To validate the authors’ technique, 4D-MRI acquisition and reconstruction were simulated on a 4D digital extended cardiac-torso (XCAT) human phantom using simulation derived parameters. Twelve healthy volunteers were involved

  17. Results from the 1997 run of the LHCb ring imaging Cherenkov test-beam

    Halley, A; Teixeira-Dias, P; Wilkinson, G; Wilkinson, Guy


    Analysis results of data from the ring imaging Cherenkov test-beam using hybrid photo diodes are presented. Details are given of the geometrical arrangement of the prototype and data-taking conditions, together with results of simulation and studies of the detector performance, photon yield and Cherenkov angle resolution using different radiators. Good agreement with simulation is found for both gas and aerogel photon yield calculations and the observed Cherenkov angle resolution.1

  18. Quality assurance in MRI breast screening: comparing signal-to-noise ratio in dynamic contrast-enhanced imaging protocols

    Kousi, Evanthia; Borri, Marco; Dean, Jamie; Panek, Rafal; Scurr, Erica; Leach, Martin O.; Schmidt, Maria A.


    MRI has been extensively used in breast cancer staging, management and high risk screening. Detection sensitivity is paramount in breast screening, but variations of signal-to-noise ratio (SNR) as a function of position are often overlooked. We propose and demonstrate practical methods to assess spatial SNR variations in dynamic contrast-enhanced (DCE) breast examinations and apply those methods to different protocols and systems. Four different protocols in three different MRI systems (1.5 and 3.0 T) with receiver coils of different design were employed on oil-filled test objects with and without uniformity filters. Twenty 3D datasets were acquired with each protocol; each dataset was acquired in under 60 s, thus complying with current breast DCE guidelines. In addition to the standard SNR calculated on a pixel-by-pixel basis, we propose other regional indices considering the mean and standard deviation of the signal over a small sub-region centred on each pixel. These regional indices include effects of the spatial variation of coil sensitivity and other structured artefacts. The proposed regional SNR indices demonstrate spatial variations in SNR as well as the presence of artefacts and sensitivity variations, which are otherwise difficult to quantify and might be overlooked in a clinical setting. Spatial variations in SNR depend on protocol choice and hardware characteristics. The use of uniformity filters was shown to lead to a rise of SNR values, altering the noise distribution. Correlation between noise in adjacent pixels was associated with data truncation along the phase encoding direction. Methods to characterise spatial SNR variations using regional information were demonstrated, with implications for quality assurance in breast screening and multi-centre trials.

  19. Does improved access to diagnostic imaging results reduce hospital length of stay? A retrospective study

    Hurlen Petter


    Full Text Available Abstract Background One year after the introduction of Information and Communication Technology (ICT to support diagnostic imaging at our hospital, clinicians had faster and better access to radiology reports and images; direct access to Computed Tomography (CT reports in the Electronic Medical Record (EMR was particularly popular. The objective of this study was to determine whether improvements in radiology reporting and clinical access to diagnostic imaging information one year after the ICT introduction were associated with a reduction in the length of patients' hospital stays (LOS. Methods Data describing hospital stays and diagnostic imaging were collected retrospectively from the EMR during periods of equal duration before and one year after the introduction of ICT. The post-ICT period was chosen because of the documented improvement in clinical access to radiology results during that period. The data set was randomly split into an exploratory part used to establish the hypotheses, and a confirmatory part. The data was used to compare the pre-ICT and post-ICT status, but also to compare differences between groups. Results There was no general reduction in LOS one year after ICT introduction. However, there was a 25% reduction for one group - patients with CT scans. This group was heterogeneous, covering 445 different primary discharge diagnoses. Analyses of subgroups were performed to reduce the impact of this divergence. Conclusion Our results did not indicate that improved access to radiology results reduced the patients' LOS. There was, however, a significant reduction in LOS for patients undergoing CT scans. Given the clinicians' interest in CT reports and the results of the subgroup analyses, it is likely that improved access to CT reports contributed to this reduction.

  20. Susceptibility weighted imaging (SWI) of the kidney at 3 T. Initial results

    Mie, Moritz B.; Zoellner, Frank G.; Heilmann, Melanie; Schad, Lothar R. [Heidelberg Univ. Medizinische Fakultaet Mannheim (Germany). Computer Assisted Clinical Medicine; Nissen, Johanna C.; Schoenberg, Stefan O.; Michaely, Henrik J. [Heidelberg Univ. Medizinische Fakultaet Mannheim (Germany). Inst. of Clinical Radiology and Nuclear Medicine


    Susceptibility weighted imaging provides diagnostic information in strokes, hemorrhages, and cerebral tumors and has proven to be a valuable tool in imaging venous vessels in the cerebrum. The SWI principle is based on the weighting of T{sub 2}{sup *} weighted magnitude images with a phase mask, therewith improving image contrast of veins or neighbouring structures of different susceptibility, in general. T{sub 2}{sup *} weighted MRI is already used for assessment of kidney function. In this paper, the feasibility of SWI on kidneys was investigated. Translation of SWI from the brain to the kidneys comes along with two main challenges: (i) organ motion due to breathing and (ii) a higher oxygenation level of renal veins compared to the brain. To handle these problems, the acquisition time has been cut down to allow for breath-hold examinations, and different post-processing methods including a new phase mask were investigated to visualize renal veins. Results showed that by a new post-processing strategy SWI contrast was enhanced on average by a factor of 1.33 compared to the standard phase mask. In summary, initial experiences of SWI on the kidneys demonstrated the feasibility. However, further technical developments have to be performed to make this technology applicable in clinical abdominal MRI. (orig.)

  1. First Results from a Coherence Imaging Diagnostic for the Compact Toroidal Hybrid

    Ennis, D. A.; Hartwell, G. J.; Johnson, C. A.; Maurer, D. A.; Allen, S. L.


    An optical coherence imaging diagnostic is being commissioned for time-resolved measurements (~ 10 ms) of ion emissivity, velocity, and temperature in the Compact Toroidal Hybrid (CTH) experiment. The Coherence Imaging (CI) technique measures the spectral coherence of an emission line with an imaging interferometer of fixed delay. CI has a number of advantages when compared to dispersive Doppler spectroscopy, including higher throughput and the capability to provide 2D spectral images, making it advantageous for investigating the non-axisymmetric geometry of CTH plasmas. A spectral survey of the visible and ultraviolet emission for a range of CTH discharges has identified helium and carbon impurity lines that will be utilized for CI measurements in CTH. First CI measurements of He II (468.6 nm) emission from CTH plasmas will be presented along with interferograms from a calibration light source and details of the instrument design. Results from this diagnostic will aid in characterizing the equilibrium ion parameters in both the edge and core of CTH plasmas for planned island divertor and MHD mode-locking experiments. Work supported by USDoE grant DE-FG02-00ER54610.

  2. Energetic Neutral Atom Imaging with the POLAR CEPPAD/ IPS Instrument : Initial Forward Modeling Results

    Henderson, M. G.; Reeves, G. D.; Moore, K. R.; Spence, H. E.; Jorgensen, A. M.; Fennell, J. F.; Blake, J. B.; Roelof, E. C.


    Although the primary function of the CEPPAD/IPS instrument on Polar is the measurement of energetic ions in-situ, it has also proven to be a very capable Energetic Neutral Atom (ENA) imager. Raw ENA images are currently being constructed on a routine basis with a temporal resolution of minutes during both active and quiet times. However, while analyses of these images by themselves provide much information on the spatial distribution and dynamics of the energetic ion population in the ring current. detailed modeling is required to extract the actual ion distributions. In this paper. we present the initial results of forward modeling an IPS ENA image obtained during a small geo-magnetic storm on June 9, 1997. The equatorial ion distribution inferred with this technique reproduces the expected large noon/midnight and dawn/dusk asymmetries. The limitations of the model are discussed and a number of modifications to the basic forward modeling technique are proposed which should significantly improve its performance in future studies.

  3. First results from imaging riometer installed at Indian Antarctic station Maitri

    Jayanta K Behera; A K Sinha; Anand K Singh; Rahul Rawat; Geeta Vichare; Ajay Dhar; B M Pathan; K U Nair; C Selvaraj; P Elango


    Cosmic noise absorption (CNA) measurred by imaging riometer, is an excellent tool to passively study the high latitude D-region ionospheric conditions and dynamics. An imaging riometer has been installed at Indian Antarctic station Maitri (geographic 70.75°S, 11.75°E; corrected geomagnetic 63.11°S, 53.59°E) in February 2010. This is the first paper using the imaging riometer data from Maitri. The present paper introduces the details of this facility, including its instrumentation, related CNA theory and its applications. Sidereal shift of around 2 hours in the diurnal pattern validates the data obtained from the newly installed instrument. Moreover, the strength of cosmic noise signal on quiet days also varies with months. This is apparently due to solar ionization of D-region ionosphere causing enhanced electron density where collision frequency is already high. The main objective of installing the imaging riometer at Maitri is to study magneotspheric–ionospheric coupling during substorm processes. In the current study, we present two typical examples of disturbed time CNA associated with storm-time and non-storm time substorm. Results reveal that CNA is more pronounced during storm-time substorm as compared to nonstorm-time substorm. The level of CNA strongly depends upon the strengthening of convectional electric field and the duration of southward turning of interplanetary magnetic field before the substorm onset.

  4. Recent Results of the Remote Sensing of the O/N2 Ratio in the 100 to 200 Km Altitude Region

    Hecht, J. H.


    The O/N2 ratio is a sensitive indicator of dynamical changes in the composition of the lower Thermosphere. In the auroral zone the deposition of auroral energy (either through particle precipitation or Joule heating) can produce changes in vertical winds causing a decrease in the O/N2 ratio. Horizontal winds may transport O-depleted air away from the auroral zone causing composition changes in the latitude regions equatorward of the auroral zone. Large waves and tides may also affect composition. To measure such composition changes a number of complimentary remote sensing techniques exist. In the auroral zone ground-based photometers have been sued to monitor, at night, variations of the column O/N2 at a single location as a function of time. Satellite observations (most notably the GUVI instrument on TIMED) provide column O/N2 variations during the daytime as a function of latitude at a nearly fixed local time. Rockets have recently been shown to be able to measure vertical variations in an auroral arc providing altitude-based measurements. Here we review some of the most recent results with an emphasis on comparison with the model predictions of MSIS.

  5. Clinical practice of image-guided spine radiosurgery - results from an international research consortium

    Guckenberger Matthias


    Full Text Available Abstract Background Spinal radiosurgery is a quickly evolving technique in the radiotherapy and neurosurgical communities. However, the methods of spine radiosurgery have not been standardized. This article describes the results of a survey about the methods of spine radiosurgery at five international institutions. Methods All institutions are members of the Elekta Spine Radiosurgery Research Consortium and have a dedicated research and clinical focus on image-guided radiosurgery. The questionnaire consisted of 75 items covering all major steps of spine radiosurgery. Results Strong agreement in the methods of spine radiosurgery was observed. In particular, similarities were observed with safety and quality assurance playing an important role in the methods of all institutions, cooperation between neurosurgeons and radiation oncologists in case selection, dedicated imaging for target- and organ-at-risk delineation, application of proper safety margins for the target volume and organs-at-risk, conformal planning and precise image-guided treatment delivery, and close clinical and radiological follow-up. In contrast, three major areas of uncertainty and disagreement were identified: 1 Indications and contra-indications for spine radiosurgery; 2 treatment dose and fractionation and 3 tolerance dose of the spinal cord. Conclusions Results of this study reflect the current practice of spine radiosurgery in large academic centers. Despite close agreement was observed in many steps of spine radiosurgery, further research in form of retrospective and especially prospective studies is required to refine the details of spinal radiosurgery in terms of safety and efficacy.

  6. The Compton Spectrometer and Imager: Results from the 2016 Super-Pressure Balloon Campaign

    Lowell, Alexander; Boggs, Steven; Chiu, Jeng-Lun; Kierans, Carolyn; Sleator, Clio; Tomsick, John; Zoglauer, Andreas; Amman, Mark; Chang, Hsiang-Kuang; Tseng, Chao-Hsiung; Yang, Chien-Ying; Lin, Chih H.; Jean, Pierre; von Ballmoos, Peter


    The Compton Spectrometer and Imager is a 0.2-5 MeV Compton telescope capable of imaging, spectroscopy and polarimetry of astrophysical sources. Such capabilities are made possible by COSI's twelve germanium cross-strip detectors, which provide for high efficiency, high resolution spectroscopy, and precise 3D positioning of photon interactions. In May 2016, COSI took flight from Wanaka, New Zealand on a NASA super-pressure balloon. For 46 days, COSI floated at a nominal altitude of 33.5 km, continually telemetering science data in real-time. The payload made a safe landing in Peru, and the hard drives containing the full raw data set were recovered. Analysis efforts have resulted in detections of various sources such as the Crab Nebula, Cyg X-1, Cen A, Galactic Center e+e- annihilation, and the long duration gamma-ray burst GRB 160530A. In this presentation, I will provide an overview of our main results, which include measuring the polarization of GRB 160530A, and our image of the Galactic Center at 511 keV. Additionally, I will summarize results pertaining to our detections of the Crab Nebula, Cyg X-1, and Cen A.

  7. The ZIMPOL high contrast imaging polarimeter for SPHERE: polarimetric high contrast commissioning results

    Roelfsema, Ronald; Bazzon, Andreas; Schmid, Hans Martin; Pragt, Johan; Govaert, Alain; Gisler, Daniel; Dominik, Carsten; Baruffolo, Andrea; Beuzit, Jean-Luc; Costille, Anne; Dohlen, Kjetil; Downing, Mark; Elswijk, Eddy; de Haan, Menno; Hubin, Norbert; Kasper, Markus; Keller, Christoph; Lizon, Jean-Louis; Mouillet, David; Pavlov, Alexey; Puget, Pascal; Salasnich, Bernardo; Sauvage, Jean-Francois; Wildi, Francois


    SPHERE (Spectro-Polarimetric High-contrast Exoplanet Research) is a second generation VLT instrument aimed at the direct detection of exo-planets. It has received its first light in May 2014. ZIMPOL (Zurich Imaging Polarimeter) is the imaging polarimeter subsystem of the SPHERE instrument. It's capable of both high accuracy and high sensitivity polarimetry but can also be used as a classical imager. It is located behind an extreme AO system and a stellar coronagraph. ZIMPOL operates at visible wavelengths which is best suited to detect the very faint reflected and hence polarized visible light from extra solar planets. During the SPHERE fourth commissioning period (October 2014) we have made deep coronagraphic observations of the bright star alpha Gru (mR = 1.75) to assess the high contrast polarimetric performance of SPHERE-ZIMPOL. We have integrated on the target for a total time of about 45 minutes during the meridian transit in the Very Broad Band filter (600 - 900 nm) with a classical Lyot coronagraph with 3 λ/D radius focal mask. We reduce the data by a combination of Polarized Background subtraction, Polarimetric Differential Imaging (PDI) and Angular Differential Imaging (ADI). We reach contrasts of 10-6 and 10-7 at a radial distances of respectively 7 and 14 lambda/D from the PSF core. At these radial distances we are respectively a factor of 10 and 2 above the photon noise limit. We discuss our results by considering the temporal and spatial speckle behavior close to the PSF core in combination with low order polarimetric aberrations.

  8. Patient body image, self-esteem, and cosmetic results of minimally invasive robotic cardiac surgery.

    İyigün, Taner; Kaya, Mehmet; Gülbeyaz, Sevil Özgül; Fıstıkçı, Nurhan; Uyanık, Gözde; Yılmaz, Bilge; Onan, Burak; Erkanlı, Korhan


    Patient-reported outcome measures reveal the quality of surgical care from the patient's perspective. We aimed to compare body image, self-esteem, hospital anxiety and depression, and cosmetic outcomes by using validated tools between patients undergoing robot-assisted surgery and those undergoing conventional open surgery. This single-center, multidisciplinary, randomized, prospective study of 62 patients who underwent cardiac surgery was conducted at Hospital from May 2013 to January 2015. The patients were divided into two groups: the robotic group (n = 33) and the open group (n = 29). The study employed five different tools to assess body image, self-esteem, and overall patient-rated scar satisfaction. There were statistically significant differences between the groups in terms of self-esteem scores (p = 0.038), body image scores (p = 0.026), overall Observer Scar Assessment Scale (p = 0.013), and overall Patient Scar Assessment Scale (p = 0.036) scores in favor of the robotic group during the postoperative period. Robot-assisted surgery protected the patient's body image and self-esteem, while conventional open surgery decreased these levels but without causing pathologies. Preoperative depression and anxiety level was reduced by both robot-assisted surgery and conventional open surgery. The groups did not significantly differ on Patient Satisfaction Scores and depression/anxiety scores. The results of this study clearly demonstrated that a minimally invasive approach using robotic-assisted surgery has advantages in terms of body image, self-esteem, and cosmetic outcomes over the conventional approach in patients undergoing cardiac surgery. Copyright © 2017 IJS Publishing Group Ltd. Published by Elsevier Ltd. All rights reserved.

  9. System and method for investigating sub-surface features and 3D imaging of non-linear property, compressional velocity VP, shear velocity VS and velocity ratio VP/VS of a rock formation

    Vu, Cung Khac; Skelt, Christopher; Nihei, Kurt; Johnson, Paul A.; Guyer, Robert; Ten Cate, James A.; Le Bas, Pierre-Yves; Larmat, Carene S.


    A system and a method for generating a three-dimensional image of a rock formation, compressional velocity VP, shear velocity VS and velocity ratio VP/VS of a rock formation are provided. A first acoustic signal includes a first plurality of pulses. A second acoustic signal from a second source includes a second plurality of pulses. A detected signal returning to the borehole includes a signal generated by a non-linear mixing process from the first and second acoustic signals in a non-linear mixing zone within an intersection volume. The received signal is processed to extract the signal over noise and/or signals resulting from linear interaction and the three dimensional image of is generated.

  10. System and method for investigating sub-surface features and 3D imaging of non-linear property, compressional velocity VP, shear velocity VS and velocity ratio VP/VS of a rock formation

    Vu, Cung Khac; Skelt, Christopher; Nihei, Kurt; Johnson, Paul A.; Guyer, Robert; Ten Cate, James A.; Le Bas, Pierre-Yves; Larmat, Carene S.


    A system and a method for generating a three-dimensional image of a rock formation, compressional velocity VP, shear velocity VS and velocity ratio VP/VS of a rock formation are provided. A first acoustic signal includes a first plurality of pulses. A second acoustic signal from a second source includes a second plurality of pulses. A detected signal returning to the borehole includes a signal generated by a non-linear mixing process from the first and second acoustic signals in a non-linear mixing zone within an intersection volume. The received signal is processed to extract the signal over noise and/or signals resulting from linear interaction and the three dimensional image of is generated.

  11. Abnormal Patella Height Based on Insall-Salvati Ratio and its Correlation with Patellar Cartilage Lesions: An Extremity-Dedicated Low-Field Magnetic Resonance Imaging Analysis of 1703 Chinese Cases.

    Lu, W; Yang, J; Chen, S; Zhu, Y; Zhu, C


    Diagnostic performance of patellar position for patellar cartilage lesions remains unclear. The aim of this study was to assess the abnormal patella height and its correlation with chondral lesions of the patellofemoral joint in China. A total of 1703 consecutive patients who performed knee joint examination using an extremity-dedicated low-field magnetic resonance imaging were enrolled in this study. Patellar cartilage lesions were diagnosed based on the result of magnetic resonance imaging and clinical data. Patella height was defined as the ratio of patellar tendon length to patellar length according to Insall-Salvati index. Patella alta and infera were defined as tendon length/patellar length >1.2 and patella alta and infera (p patella height had statistical significance in diagnosing cartilage lesions (p patella height is significantly correlated with chondral lesions and can be used as a potential diagnostic marker. © The Finnish Surgical Society 2015.

  12. Calibration results using highly aberrated images for aligning the JWST instruments to the telescope

    Smith, Koby Z.; Acton, D. Scott; Gallagher, Ben B.; Knight, J. Scott; Dean, Bruce H.; Jurling, Alden S.; Zielinski, Thomas P.


    mostly of 3rd-order astigmatism and coma. This is because the elliptical tertiary mirror of the AOS is used off of its ideal foci locations without the compensating wavefront effects of the JWST primary and secondary mirrors. Therefore, the PSFs created are highly asymmetric with relatively complex structure and the centroid and encircled energy analyses traditionally used to locate images are not sufficient for ensuring the AOS to ISIM alignment. A novel approach combining phase retrieval and spatial metrology was developed to both locate the images with respect to the AOS and provide calibration information for eventual AOS to ISIM alignment verification. During final JWST OTE and ISIM (OTIS) testing, only a single thru-focus image will be collected by the instruments. Therefore, tools and processes were developed to perform single-image phase retrieval on these highly aberrated images such that any single image of the ASPA source can provide calibrated knowledge of the instruments' position relative to the AOS. This paper discusses the results of the methodology, hardware, and calibration performed to ensure that the AOS and ISIM are aligned within their respective tolerances at JWST OTIS testing.

  13. Range imaging observations of PMSE using the EISCAT VHF radar: Phase calibration and first results

    J. R. Fernandez


    Full Text Available A novel phase calibration technique for use with the multiple-frequency Range IMaging (RIM technique is introduced based on genetic algorithms. The method is used on data collected with the European Incoherent SCATter (EISCAT VHF radar during a 2002 experiment with the goal of characterizing the vertical structure of Polar Mesosphere Summer Echoes (PMSE over northern Norway. For typical Doppler measurements, the initial phases of the transmitter and receiver are not required to be the same. The EISCAT receiver systems exploit this fact, allowing a multi-static configuration. However, the RIM method relies on the small phase differences between closely spaced frequencies. As a result, the high-resolution images produced by the RIM method can be significantly degraded if not properly calibrated. Using an enhanced numerical radar simulator, in which data from multiple sampling volumes are simultaneously generated, the proposed calibration method is validated. Subsequently, the method is applied to preliminary data from the EISCAT radar, providing first results of RIM images of PMSE. Data using conventional analysis techniques, and confirmed by RIM, reveal an often-observed double-layer structure with higher stability in the lower layer. Moreover, vertical velocity oscillations exhibit a clear correlation with the apparent motion of the layers shown in the echo power plots.

  14. Grooved Terrain on Ganymede: First Results from Galileo High-Resolution Imaging

    Pappalardo, R.T.; Head, J.W.; Collins, G.C.; Kirk, R.L.; Neukum, G.; Oberst, J.; Giese, B.; Greeley, R.; Chapman, C.R.; Helfenstein, P.; Moore, Johnnie N.; McEwen, A.; Tufts, B.R.; Senske, D.A.; Herbert, Breneman H.; Klaasen, K.


    High-resolution Galileo imaging has provided important insight into the origin and evolution of grooved terrain on Ganymede. The Uruk Sulcus target site was the first imaged at high resolution, and considerations of resolution, viewing geometry, low image compression, and complementary stereo imaging make this region extremely informative. Contrast variations in these low-incidence angle images are extreme and give the visual impression of topographic shading. However, photometric analysis shows that the scene must owe its character to albedo variations. A close correlation of albedo variations to topography is demonstrated by limited stereo coverage, allowing extrapolation of the observed brightness and topographic relationships to the rest of the imaged area. Distinct geological units are apparent across the region, and ridges and grooves are ubiquitous within these units. The stratigraphically lowest and most heavily cratered units ("lineated grooved terrain") generally show morphologies indicative of horst-and-graben-style normal faulting. The stratigraphically highest groove lanes ("parallel ridged terrain") exhibit ridges of roughly triangular cross section, suggesting that tilt-block-style normal faulting has shaped them. These extensional-tectonic models are supported by crosscutting relationships at the margins of groove lanes. Thus, a change in tectonic style with time is suggested in the Uruk Sulcus region, varying from horst and graben faulting for the oldest grooved terrain units to tilt block normal faulting for the latest units. The morphologies and geometries of some stratigraphically high units indicate that a strike-slip component of deformation has played an important role in shaping this region of grooved terrain. The most recent tectonic episode is interpreted as right-lateral transtension, with its tectonic pattern of two contemporaneous structural orientations superimposed on older units of grooved terrain. There is little direct evidence for

  15. Molecular breast imaging: First results from Italian-National-Institute-of-Health clinical trials

    Cusanno, F.; Cisbani, E.; Colilli, S.; Fratoni, R.; Garibaldi, F.; Giuliani, F.; Gricia, M.; Lucentini, M.; Magliozzi, M. L.; Santanvenere, F.; Torrioli, S.; Cinti, M. N.; Pani, R.; Pellegrini, R.; Simonetti, G.; Schillaci, O.; Del Vecchio, S.; Salvatore, M.; Majewski, S.; De Vincentis, G.; Scopinaro, F.


    Dedicated high resolution detectors are needed for detection of small tumors by molecular imaging with radionuclides. Absorptive collimation are typically used for imaging single photon emitters, but it results in a strong reduction in efficiency. Systems based on electronic collimation offer higher efficiency but they are complex and expensive. In case of scintimammography, dual-head detectors increase sensitivity and cancel out the dependence of the lesion depth. In the system presented here, pixellated scintillator arrays (NaI:Tl) were coupled to arrays of PSPMT's, HPK H8500 Flat Panel. A dual-head detector having field of view of 100×100 mm 2 and 150×200 mm 2 were designed and built. The electronic system allows readout of all the anode pad signals. First clinical trials, performed in the framework of the Scintimammography project of Italian National Institute of Health and University of Tor Vergata in Rome, and University of Naples, are presented.

  16. A uniqueness result for propagation-based phase contrast imaging from a single measurement

    Maretzke, Simon


    Phase contrast imaging seeks to reconstruct the complex refractive index of an unknown sample from scattering intensities, measured for example under illumination with coherent X-rays. By incorporating refraction, this method yields improved contrast compared to purely absorption-based radiography but involves a phase retrieval problem which, in general, allows for ambiguous reconstructions. In this paper, we show uniqueness of propagation-based phase contrast imaging for compactly supported objects in the near field regime, based on a description by the projection- and paraxial approximations. In this setting, propagation is governed by the Fresnel propagator and the unscattered part of the illumination function provides a known reference wave at the detector which facilitates phase reconstruction. The uniqueness theorem is derived using the theory of entire functions. Unlike previous results based on exact solution formulae, it is valid for arbitrary complex objects and requires intensity measurements only ...

  17. Cardiac CT for the assessment of chest pain: Imaging techniques and clinical results

    Becker, Hans-Christoph, E-mail: [Ludwig-Maximilians-University, Grosshadern Clinic, Department of Clinical Radiology, Marchioninistr. 15, 81377 Munich (Germany); Johnson, Thorsten [Ludwig-Maximilians-University, Grosshadern Clinic, Department of Clinical Radiology, Marchioninistr. 15, 81377 Munich (Germany)


    Immediate and efficient risk stratification and management of patients with acute chest pain in the emergency department is challenging. Traditional management of these patients includes serial ECG, laboratory tests and further on radionuclide perfusion imaging or ECG treadmill testing. Due to the advances of multi-detector CT technology, dedicated coronary CT angiography provides the potential to rapidly and reliably diagnose or exclude acute coronary artery disease. Life-threatening causes of chest pain, such as aortic dissection and pulmonary embolism can simultaneously be assessed with a single scan, sometimes referred to as “triple rule out” scan. With appropriate patient selection, cardiac CT can accurately diagnose heart disease or other sources of chest pain, markedly decrease health care costs, and reliably predict clinical outcomes. This article reviews imaging techniques and clinical results for CT been used to evaluate patients with chest pain entering the emergency department.

  18. New microangiography system development providing improved small vessel imaging, increased contrast to noise ratios, and multi-view 3D reconstructions.

    Kuhls, Andrew T; Patel, Vikas; Ionita, Ciprian; Noël, Peter B; Walczak, Alan M; Rangwala, Hussain S; Hoffmann, Kenneth R; Rudin, Stephen


    A new microangiographic system (MA) integrated into a c-arm gantry has been developed allowing precise placement of a MA at the exact same angle as the standard x-ray image intensifier (II) with unchanged source and object position. The MA can also be arbitrarily moved about the object and easily moved into the field of view (FOV) in front of the lower resolution II when higher resolution angiographic sequences are needed. The benefits of this new system are illustrated in a neurovascular study, where a rabbit is injected with contrast media for varying oblique angles. Digital subtraction angiographic (DSA) images were obtained and compared using both the MA and II detectors for the same projection view. Vessels imaged with the MA appear sharper with smaller vessels visualized. Visualization of ~100 μm vessels was possible with the MA whereas not with the II. Further, the MA could better resolve vessel overlap. Contrast to noise ratios (CNR) were calculated for vessels of varying sizes for the MA versus the II and were found to be similar for large vessels, approximately double for medium vessels, and infinitely better for the smallest vessels. In addition, a 3D reconstruction of selected vessel segments was performed, using multiple (three) projections at oblique angles, for each detector. This new MA/II integrated system should lead to improved diagnosis and image guidance of neurovascular interventions by enabling initial guidance with the low resolution large FOV II combined with use of the high resolution MA during critical parts of diagnostic and interventional procedures.

  19. Tumor Extension in High-Grade Gliomas Assessed with Diffusion Magnetic Resonance Imaging: Values and Lesion-to-Brain Ratios of Apparent Diffusion Coefficient and Fractional Anisotropy

    Westen, D. van; Laett, J.; Englund, E.; Brockstedt, S.; Larsson, E.M. [Lund Univ. Hospital (Sweden). Depts. of Radiology, of Medical Radiation Physics and of Pathology and Cytology


    Purpose: To determine whether the apparent diffusion coefficient (ADC) and fractional anisotropy (FA) can distinguish tumor-infiltrated edema in gliomas from pure edema in meningiomas and metastases. Material and Methods: Thirty patients were studied: 18 WHO grade III or IV gliomas, 7 meningiomas, and 5 metastatic lesions. ADC and FA were determined from ROIs placed in peritumoral areas with T2-signal changes, adjacent normal appearing white matter (NAWM), and corresponding areas in the contralateral healthy brain. Values and lesion-to-brain ratios from gliomas were compared to those from meningiomas and metastases. Results: Values and lesion-to-brain ratios of ADC and FA in peritumoral areas with T2-signal changes did not differ between gliomas, meningiomas, and metastases (P = 0.40, P = 0.40, P = 0.61, P 0.34). Values of ADC and FA and the lesion-to-brain ratio of FA in the adjacent NAWM did not differ between tumor types (P = 0.74, P = 0.25, and P = 0.31). The lesion-to-brain ratio of ADC in the adjacent NAWM was higher in gliomas than in meningiomas and metastases (P = 0.004), but overlapped between tumor types. Conclusion: Values and lesion-to-brain ratios of ADC and FA in areas with T2-signal changes surrounding intracranial tumors and adjacent NAWM were not helpful for distinguishing pure edema from tumor-infiltrated edema when data from gliomas, meningiomas, and metastases were compared.

  20. Correlation between magnetic resonance T2 image signal intensity ratio and cell apoptosis in a rabbit spinal cord cervical myelopathy model

    Ma Lei; Zhang Di; Chen Wei; Shen Yong; Zhang Yingze; Ding Wenyuan; Zhang Wei


    Background Cervical spondylotic myelopathy (CSM) is a common cause of disability in elderly patients.Previous studies have shown that spinal cord cell apoptosis due to spinal cord compression plays an important role in the pathology of myelopathy.Although changes in magnetic resonance imaging (MRI) T2 signal intensity ratio (SIR) are considered to be an indicator of CSM,little information is published supporting the correlation between changes in MRI signal and pathological changes.This study aims to testify the correlation between MRI T2 SIR changes and cell apoptosis using a CSM animal model.Methods Forty-eight rabbits were randomly assigned to four groups:one control group and three experimental chronic compression groups,with each group containing 12 animals.Chronic compression of the cervical spinal cord was implemented in the experimental groups by implanting a screw in the C3 vertebra.The control group underwent sham surgery.Experimental groups were observed for 3,6,or 9 months after surgery.MRI T2-weighted SIR Tarlov motor scores and cortical somatosensory-evoked potentials (CSEPs) were periodically monitored.At each time point,rabbits from one group were sacrificed to determine the level of apoptosis by histology (n=6) and Western blotting (n=6).Results Tarlov motor scores in the compression groups were lower at all time points than the control group scores,with the lowest score at 9 months (P <0.001).Electrophysiological testing showed a significantly prolonged latency in CSEP in the compression groups compared with the control group.All rabbits in the compression groups showed higher MRI T2 SIR in the injury epicenter compared with controls,and higher SIR was also found at 9 months compared with 3 or 6 months.Histological analysis showed significant apoptosis in the spinal cord tissue in the compression groups,but not in the control group.There were significant differences in apoptosis degree over time (P <0.001),with the 9-month group displaying the

  1. In vivo sodium (23Na) imaging of the human kidneys at 7 T: preliminary results.

    Haneder, Stefan; Juras, Vladimir; Michaely, Henrik J; Deligianni, Xeni; Bieri, Oliver; Schoenberg, Stefan O; Trattnig, Siegfried; Zbýň, Štefan


    To evaluate the feasibility of in vivo (23)Na imaging of the corticomedullary (23)Na gradient and to measure (23)Na transverse relaxation times (T2*) in human kidneys. In this prospective, IRB-approved study, eight healthy volunteers (4 female, 4 male; mean age 29.4 ± 3.6 years) were examined on a 7-T whole-body MR system using a (23)Na-only spine-array coil. For morphological (23)Na-MRI, a 3D gradient echo (GRE) sequence with a variable echo time scheme (vTE) was used. T2* times were calculated using a multiecho 3D vTE-GRE approach. (23)Na signal-to-noise ratios (SNR) were given on a pixel-by-pixel basis for a 20-mm section from the cortex in the direction of the medulla. T2* maps were calculated by fitting the (23)Na signal decay monoexponentially on a pixel-by-pixel basis, using least squares fit. Mean corticomedullary (23)Na-SNR increased from the cortex (32.2 ± 5.6) towards the medulla (85.7 ± 16.0). The SNR increase ranged interindividually from 57.2% to 66.3%. Mean (23)Na-T2* relaxation times differed statistically significantly (P pyramid direction. • In vivo measurements of renal (23) Na-T2* times are demonstrated at 7.0 T.

  2. Preliminary Results of Earthquake-Induced Building Damage Detection with Object-Based Image Classification

    Sabuncu, A.; Uca Avci, Z. D.; Sunar, F.


    Earthquakes are the most destructive natural disasters, which result in massive loss of life, infrastructure damages and financial losses. Earthquake-induced building damage detection is a very important step after earthquakes since earthquake-induced building damage is one of the most critical threats to cities and countries in terms of the area of damage, rate of collapsed buildings, the damage grade near the epicenters and also building damage types for all constructions. Van-Ercis (Turkey) earthquake (Mw= 7.1) was occurred on October 23th, 2011; at 10:41 UTC (13:41 local time) centered at 38.75 N 43.36 E that places the epicenter about 30 kilometers northern part of the city of Van. It is recorded that, 604 people died and approximately 4000 buildings collapsed or seriously damaged by the earthquake. In this study, high-resolution satellite images of Van-Ercis, acquired by Quickbird-2 (Digital Globe Inc.) after the earthquake, were used to detect the debris areas using an object-based image classification. Two different land surfaces, having homogeneous and heterogeneous land covers, were selected as case study areas. As a first step of the object-based image processing, segmentation was applied with a convenient scale parameter and homogeneity criterion parameters. As a next step, condition based classification was used. In the final step of this preliminary study, outputs were compared with streetview/ortophotos for the verification and evaluation of the classification accuracy.

  3. Reconstructing a 3-dimensional image of the results of antinuclear antibody testing by indirect immunofluorescence.

    Murai, Ryosei; Yamada, Koji; Tanaka, Maki; Kuribayashi, Kageaki; Kobayashi, Daisuke; Tsuji, Naoki; Watanabe, Naoki


    Indirect immunofluorescence anti-nuclear antibody testing (IIF-ANAT) is an essential screening tool in the diagnosis of various autoimmune disorders. ANA titer quantification and interpretation of immunofluorescence patterns are determined subjectively, which is problematic. First, we determined the examination conditions under which IIF-ANAT fluorescence intensities are quantified. Next, IIF-ANAT was performed using homogeneous, discrete speckled, and mixed serum samples. Images were obtained using Bio Zero BZ-8000, and 3-dimensional images were reconstructed using the BZ analyzer software. In the 2-dimensional analysis, homogeneous ANAs hid the discrete speckled pattern, resulting in a diagnosis of homogeneous immunofluorescence. However, 3-dimensional analysis of the same sample showed discrete speckled-type ANA in the homogeneous background. This study strengthened the current IIF-ANAT method by providing a new approach to quantify the fluorescence intensity and enhance the resolution of IIF-ANAT fluorescence patterns. Reconstructed 3-dimensional imaging of IIF-ANAT can be a powerful tool for routine laboratory examination. Copyright © 2012 Elsevier B.V. All rights reserved.

  4. Radiometric flight results from the HyperSpectral Imager for Climate Science (HySICS)

    Kopp, Greg; Smith, Paul; Belting, Chris; Castleman, Zach; Drake, Ginger; Espejo, Joey; Heuerman, Karl; Lanzi, James; Stuchlik, David


    Long-term monitoring of the Earth-reflected solar spectrum is necessary for discerning and attributing changes in climate. High radiometric accuracy enables such monitoring over decadal timescales with non-overlapping instruments, and high precision enables trend detection on shorter timescales. The HyperSpectral Imager for Climate Science (HySICS) is a visible and near-infrared spatial/spectral imaging spectrometer intended to ultimately achieve ˜ 0.2 % radiometric accuracies of Earth scenes from space, providing an order-of-magnitude improvement over existing space-based imagers. On-orbit calibrations from measurements of spectral solar irradiances acquired by direct views of the Sun enable radiometric calibrations with superior long-term stability than is currently possible with any manmade spaceflight light source or detector. Solar and lunar observations enable in-flight focal-plane array (FPA) flat-fielding and other instrument calibrations. The HySICS has demonstrated this solar cross-calibration technique for future spaceflight instrumentation via two high-altitude balloon flights. The second of these two flights acquired high-radiometric-accuracy measurements of the ground, clouds, the Earth's limb, and the Moon. Those results and the details of the uncertainty analyses of those flight data are described.

  5. First results of a cryogenic optical photon-counting imaging spectrometer using a DROID array

    Hijmering, R. A.; Verhoeve, P.; Martin, D. D. E.; Venn, R.; van Dordrecht, A.; Groot, P. J.


    Context. We present the first system test in which we demonstrate the concept of using an array of Distributed Read Out Imaging Devices (DROIDs) for optical photon detection. Aims: After the successful S-Cam 3 detector, the next step in the development of a cryogenic optical photon counting imaging spectrometer under the S-Cam project is to increase the field of view using DROIDs. With this modification the field of view of the camera has been increased by a factor of five in a given area while keeping the number of readout channels the same. Methods: The test has been performed using the flexible S-Cam 3 system and exchanging the 10 × 12 Superconducting Tunnel Junction array for a 3 × 20 DROID array. The extra data reduction needed with DROIDs is performed offline. Results: We show that, although the responsivity (number of tunnelled quasiparticles per unit of absorbed photon energy, e-/eV) of the current array is too low for direct astronomical applications, the imaging quality is already good enough for pattern detection and will improve further with increasing responsivity. Conclusions: The obtained knowledge can be used to optimise the system for the use of DROIDs.

  6. First results of a cryogenic optical photon counting imaging spectrometer using a DROID array

    Hijmering, R A; Martin, D D E; Venn, R; van Dordrecht, A; Groot, P J


    Context. In this paper we present the first system test in which we demonstrate the concept of using an array of Distributed Read Out Imaging Devices (DROIDs) for optical photon detection. Aims. After the successful S-Cam 3 detector the next step in the development of a cryogenic optical photon counting imaging spectrometer under the S-Cam project is to increase the field of view using DROIDs. With this modification the field of view of the camera has been increased by a factor of 5 in area, while keeping the number of readout channels the same. Methods. The test has been performed using the flexible S-Cam 3 system and exchanging the 10x12 Superconducting Tunnel Junction array for a 3x20 DROID array. The extra data reduction needed with DROIDs is performed offline. Results. We show that, although the responsivity (number of tunnelled quasiparticles per unit of absorbed photon energy, e- /eV) of the current array is too low for direct astronomical applications, the imaging quality is already good enough for pa...

  7. Probabilistic multiscale image segmentation: set-up and first results (Proceedings Only)

    Vincken, Koen L.; Koster, Andre S.; Viergever, Max A.


    We have developed a method to segment two- and three-dimensional images using a multiscale (hyperstack) approach with probabilistic linking. A hyperstack is a voxel-based multiscale data structure containing linkages between voxels at different scales. The scale-space is constructed by repeatedly applying a discrete convolution with a Gaussian kernel to the original input image. Between these levels of increasing scale we establish child-parent linkages according to a linkage scheme that is based on affection. In the resulting tree-like data structure roots are formed to indicate the most plausible locations in scale-space where objects (of different sizes) are actually defined by a single voxel. Tracing the linkages back from every root to the ground level produces a segmented image. The present paper deals with probabilistic linking, i.e., a set-up in which a child voxel can be linked to more than one parent voxel. The output of the thus constructed hyperstack -- a list of object probabilities per voxel -- can be directly related to the opacities used in volume renderers.

  8. Retroreflective Background Oriented Schlieren Imaging Results from the NASA Plume/Shock Interaction Test

    Smith, Nathanial T.; Durston, Donald A.; Heineck, James T.


    In support of NASA's Commercial Supersonics Technology (CST) project, a test was conducted in the 9-by-7 ft. supersonic section of the NASA Ames Unitary Plan Wind Tunnel (UPWT). The tests were designed to study the interaction of shocks with a supersonic jet characteristic of those that may occur on a commercial supersonic aircraft. Multiple shock generating geometries were tested to examine the interaction dynamics as they pertain to sonic boom mitigation. An integral part of the analyses of these interactions are the interpretation of the data generated from the retroreflective Background Oriented Schlieren (RBOS) imaging technique employed for this test. The regularization- based optical flow methodology used to generate these data is described. Sample results are compared to those using normalized cross-correlation. The reduced noise, additional feature detail, and fewer false artifacts provided by the optical flow technique produced clearer time-averaged images, allowing for better interpretation of the underlying flow phenomena. These images, coupled with pressure signatures in the near field, are used to provide an overview of the detailed interaction flowfields.

  9. Age-effects in white matter using associated diffusion tensor imaging and magnetization transfer ratio during late childhood and early adolescence.

    Moura, Luciana Monteiro; Kempton, Matthew; Barker, Gareth; Salum, Giovanni; Gadelha, Ary; Pan, Pedro Mario; Hoexter, Marcelo; Del Aquilla, Marco Antonio Gomes; Picon, Felipe Almeida; Anés, Mauricio; Otaduy, Maria Concepcion Garcia; Amaro, Edson; Rohde, Luis Augusto; McGuire, Philip; Bressan, Rodrigo Affonseca; Sato, João Ricardo; Jackowski, Andrea Parolin


    In the last decade, several studies have described the typical brain white matter maturation in children and adolescents. Diffusion tensor imaging (DTI) is the most frequent MRI technique used to investigate the structural changes across development. However, few previous studies have used the magnetization transfer ratio (MTR), which gives a closer measure of myelin content. Here, we employed both techniques for the same sample of 176 typically developing children from 7 to 14years of age. We investigated the associations between DTI parameters and MTR measure, to assess the myelination in the brain in development. Secondly, we investigated age-effects on DTI parameters (fractional anisotropy, axial, radial and mean diffusivities) and MTR. No significant correlations between MTR and DTI parameters were observed. In addition, a significant age-effect was detected for DTI data but was not visible for MTR data. Thereby, changes in white matter at this age might be primarily correlated with microstructural changes.

  10. Magnetic Resonance Imaging Results Can Affect Therapy Decisions in Hyperacute Stroke Care

    Heidenreich, J.O.; Hsu, D.; Wang, G.; Jesberger, J.A.; Tarr, R.W.; Zaidat, O.O.; Sunshine, J.L. (Depts. of Radiology, Biomedical Engineering, Neurology, and Neurosurgery, Case Western Reserve Univ. and Univ. Hospitals of Cleveland, Cleveland, OH (US))


    Background: Despite some limitations, a perfusion/diffusion mismatch can provide a working estimate of the ischemic penumbra in hyperacute stroke and has successfully been used to triage patients. Purpose: To evaluate whether the addition of magnetic resonance imaging (MRI) to clinical and non-contrast computed tomography (CT) data alters diagnosis and choice of therapy. Material and Methods: We retrospectively analyzed clinical records, and CT and MRI data fully available in 97 of 117 patients. Upon clinical examination and CT, a diagnosis and treatment path was scored and compared to treatment path after addition of MRI data. The MRI protocol included T2-weighted images, diffusion-weighted images (DWI), and perfusion-weighted images (PWI), and MR angiography (MRA). Results: MRI data were acquired in less than 15 min. In 20 of 97 patients (21%), the diagnosis changed after MRI. In 25 of 97 patients (26%), the presumptive treatment plan was changed after MRI evaluation. Thirteen patients had their treatment changed from thrombolytic to nonthrombolytic therapy. Three patients were changed from nonthrombolytic to intraarterial (IA) thrombolysis. In one patient, treatment was changed from intravenous (IV) to IA thrombolysis, and in five patients it was changed from IA to IV thrombolysis. In two patients, systemic heparin was added to antiplatelet therapy. Conclusion: The expansion of the acute stroke protocol to include MRI altered the therapy plan in 26% of our patients. The utility of MRI, shown here to improve patient stratification into best-treatment options, demonstrates the value of using MRI to optimize care in hyperacute stroke patients

  11. High Contrast Imaging in the Visible: First Experimental Results at the Large Binocular Telescope

    Pedichini, F; Ambrosino, A; Puglisi, A; Pinna, E; Bailey, V; Carbonaro, L; Centrone, M; Christou, J; Esposito, S; Farinato, J; Fiore, F; Giallongo, E; Hill, J M; Hinz, P M; Sabatini, L


    In February 2014, the SHARK-VIS (System for High contrast And coronography from R to K at VISual bands) Forerunner, a high contrast experimental imager operating at visible wavelengths, was installed at LBT (Large Binocular Telescope). Here we report on the first results obtained by recent on-sky tests. These results show the extremely good performance of the LBT ExAO (Extreme Adaptive Optics) system at visible wavelengths, both in terms of spatial resolution and contrast achieved. Similarly to what was done by (Amara et al. 2012), we used the SHARK-VIS Forerunner data to quantitatively assess the contrast enhancement. This is done by injecting several different synthetic faint objects in the acquired data and applying the ADI (angular differential imaging) technique. A contrast of the order of $5 \\times 10^{-5}$ is obtained at 630 nm for angular separations from the star larger than 100 mas. These results are discussed in light of the future development of SHARK-VIS and compared to those obtained by other hi...

  12. 3-D laser scanning image denoising based on HSSIM and residual ratio threshold%利用 HSSIM 和残差比阈值的3维激光扫描图像去噪

    崔治; 邓曙光; 肖卫初


    In order to get better results of 3-D laser scanning image denoising , an improved sparse representation denoising algorithm was proposed by combining histogram structural similarity ( HSSIM ) and residual ratio threshold .The initial over-complete dictionary was applied in the sparse decomposition .The reconstruction error was replaced by similarity factor as fidelity factor.Then the residual ratio threshold was used as the iteration termination of the orthogonal matching pursuit algorithm to reconstruct the denoised image .Finally, the performance data of denoised image , such as peak signal-to-noise ratio(PSNR) and HSSIM, were obtained.The experimental results show that the proposed method could provide better PSNR and HSSIM results compared with the image denoising methods using db 2 wavelet transform , multiscale curve wave transform and discrete cosine transform.Meanwhile , the structural features can be reserved effectively by the proposed method .%为了更好地实现3维激光扫描图像的去噪,提出一种融合直方图结构相似度( HSSIM)和残差比阈值的改进稀疏去噪算法。利用初始化过完备字典进行稀疏分解,以相似因子代替重构误差作为保真项,利用残差比阈值作为正交匹配追踪算法的迭代终止条件对图像进行去噪,获得了去噪后图像的峰值信噪比及HSSIM指标。结果表明,与基于db2小波变换、多尺度曲波变换和离散余弦变换的去噪方法相比,该算法能获得更好的峰值信噪比和HSSIM数据。在有效去除图像噪声的同时还能更有效地保留图像的细节特征。

  13. Full waveform tomography for lithospheric imaging: results from a blind test in a realistic crustal model

    Brenders, A. J.; Pratt, R. G.


    A comprehensive validation of 2-D, frequency-domain, acoustic wave-equation tomography was undertaken in a `blind test', using third-party, realistic, elastic wave-equation data. The synthetic 2-D, wide-angle seismic data were provided prior to a recent workshop on the methods of controlled source seismology; the true model was not revealed to the authors until after the presentation of our waveform tomography results. The original model was specified on a detailed grid with variable P-wave velocity, S-wave velocity, density and viscoelastic Q-factor structure, designed to simulate a section of continental crust 250 km long and 40 km deep. Synthetic vertical and horizontal component data were available for 51 shot locations (spaced every 5 km), recorded at 2779 receivers (spaced every 90 m), evenly spread along the surface of the model. The data contained energy from 0.2 to 15 Hz. Waveform tomography, a combination of traveltime tomography and 2-D waveform inversion of the early arrivals of the seismic waveforms, was used to recover crustal P-velocity structure from the vertical component data, using data from 51 sources, 1390 receivers and frequencies between 0.8 and 7.0 Hz. The waveform tomography result contained apparent structure at wavelength-scale resolution that was not evident on the traveltime tomography result. The predicted (acoustic) waveforms in the final result matched the original elastic data to a high degree of accuracy. During the workshop, the exact model was revealed; over much of the model the waveform tomography results provided a good correspondence with the true model, from large- to intermediate-(wavelength) scales, with a resolution limit on the order of 1 km. A significant, near-surface low-velocity zone, invisible to traveltime methods, was correctly recovered; the results also provided a high-resolution image of the complex structure of the entire crust, and the depth and nature of the crust-mantle transition. Some inaccuracies were

  14. Generating Representative Sets and Summaries for Large Collection of Images Using Image Cropping Techniques and Result Comparison

    Abdullah Al-Mamun


    Full Text Available The collection of photos hosted on photo archives and social networking sites has been increasing exponentially. It is really hard to get the summary of a large image set without browsing through the entire collection. In this paper two different techniques of image cropping (random windows technique and sequential windows technique have been proposed to generate effective representative sets. A ranking mechanism has been also proposed for finding the best representative set.

  15. Strong Nebular Line Ratios in the Spectra of z~2-3 Star-forming Galaxies: First Results from KBSS-MOSFIRE

    Steidel, C C; Strom, A L; Pettini, M; Reddy, N A; Shapley, A E; Trainor, R F; Erb, D K; Turner, M L; Konidaris, N P; Kulas, K R; Mace, G; Matthews, K; McLean, I S


    We present initial results of a large near-IR spectroscopic survey covering the 15 fields of the Keck Baryonic Structure Survey (KBSS) using the recently-commissioned MOSFIRE instrument on the Keck 1 10m telescope. We focus on 179 galaxies with redshifts 2.0 < z < 2.6, most of which have high-quality MOSFIRE spectra in both H and K-band atmospheric windows, allowing sensitive measurements of [OIII]4960,5008, H-beta, [NII]6585, and H-alpha emission lines. We show unambiguously that the locus of z~2.3 galaxies in the "BPT" nebular diagnostic diagram exhibits an almost entirely disjoint, yet similarly tight, relationship between the line ratios [NII]/Halpha and [OIII]/Hbeta as compared to local galaxies. We argue that the offset of the z~2.3 BPT locus relative to that at z~0 is caused primarily by higher excitation (driven by both higher ionization parameter and harder stellar ionizing radiation field) than applies to most local galaxies. Also unlike nearby counterparts, a z~2.3 galaxy's position along the...

  16. Post-mortem imaging of laryngohyoid fractures in strangulation incidents: first results.

    Kempter, M; Ross, S; Spendlove, D; Flach, P M; Preiss, U; Thali, M J; Bolliger, S A


    Fractures and soft-tissue injuries of the neck are of great importance in forensic pathology, as they help in assessing whether strangulation took place, and if so, how severely. In this study, we examined the usefulness of post-mortem imaging with multislice computed tomography (MSCT) in detecting lesions of the laryngohyoid structures and the surrounding soft-tissues. For this purpose, we examined MSCT images of the neck of eight deceased persons who had suffered different types of strangulation and compared the findings with those obtained at the subsequent forensic autopsy. In six of the eight cases (75%), the fracture findings at autopsy were concordant with those found with MSCT. In the two non-congruent cases, MSCT revealed fractures, which were not discovered at autopsy. Soft-tissue haemorrhages were detected by autopsy in five cases, but only in one case with MSCT. MSCT does not suffice in detecting soft-tissue injuries. These preliminary results are promising regarding the detection of fractures in strangulation cases. If these results can be confirmed in larger studies, we believe that post-mortem MSCT may serve - in combination with a thorough external examination and a profound incident-scene investigation - as a useful decision-making tool regarding the necessity of further examinations, i.e. autopsy.


    Kitching, T. D.; Heymans, C. [Mullard Space Science Laboratory, University College London, Holmbury St. Mary, Dorking, Surrey RH5 6NT (United Kingdom); Rowe, B.; Witherick, D. [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom); Gill, M. [Center for Cosmology and AstroParticle Physics, Physics Department, The Ohio State University, Columbus, OH (United States); Massey, R. [Institute for Computational Cosmology, Durham University, South Road, Durham DH1 3LE (United Kingdom); Courbin, F.; Gentile, M.; Meylan, G. [Laboratoire d' Astrophysique, Ecole Polytechnique Federale de Lausanne (EPFL) (Switzerland); Georgatzis, K. [Department of Information and Computer Science, Aalto University, P.O. Box 15400, FI-00076 Aalto (Finland); Gruen, D. [Department of Physics and Astronomy, 209 South 33rd Street, University of Pennsylvania, Philadelphia, PA 19104 (United States); Kilbinger, M. [Excellence Cluster Universe, Boltzmannstr. 2, D-85748 Garching (Germany); Li, G. L. [Purple Mountain Observatory, 2 West Beijing Road, Nanjing 210008 (China); Mariglis, A. P.; Storkey, A. [School of Informatics, University of Edinburgh, 10 Crichton Street, Edinburgh EH8 9AB (United Kingdom); Xin, B., E-mail: [Department of Physics, Purdue University, 525 Northwestern Avenue, West Lafayette, IN 47907 (United States)


    We present the results from the first public blind point-spread function (PSF) reconstruction challenge, the GRavitational lEnsing Accuracy Testing 2010 (GREAT10) Star Challenge. Reconstruction of a spatially varying PSF, sparsely sampled by stars, at non-star positions is a critical part in the image analysis for weak lensing where inaccuracies in the modeled ellipticity e and size R {sup 2} can impact the ability to measure the shapes of galaxies. This is of importance because weak lensing is a particularly sensitive probe of dark energy and can be used to map the mass distribution of large scale structure. Participants in the challenge were presented with 27,500 stars over 1300 images subdivided into 26 sets, where in each set a category change was made in the type or spatial variation of the PSF. Thirty submissions were made by nine teams. The best methods reconstructed the PSF with an accuracy of {sigma}(e) Almost-Equal-To 2.5 Multiplication-Sign 10{sup -4} and {sigma}(R {sup 2})/R {sup 2} Almost-Equal-To 7.4 Multiplication-Sign 10{sup -4}. For a fixed pixel scale, narrower PSFs were found to be more difficult to model than larger PSFs, and the PSF reconstruction was severely degraded with the inclusion of an atmospheric turbulence model (although this result is likely to be a strong function of the amplitude of the turbulence power spectrum).

  18. The Crossmatch/Issue Ratio:  Use of a Novel Quality Indicator and Results of an International Survey on RBC Crossmatching and Issuing Practices

    Yazer, Mark H; Alcantara, Ramir; Beizai, Pouneh


    OBJECTIVES: To understand the worldwide scope of RBC crossmatching and issuing practices and measure efficiency using a novel quality indicator, the crossmatch/issue (C/I) ratio. METHODS: An electronic survey was disseminated to hospital transfusion services collecting details about RBC....... 1.35 ± 0.36, respectively; P = .19). CONCLUSIONS: Electronic crossmatching is common, and the C/I ratio can be an indicator of efficiency....

  19. Survey of Experimental Results in High-Contrast Imaging for Future Exoplanet Missions

    Lawson, P. R.; Belikov, R.; Cash, W.; Clampin, M.; Glassman, T.; Guyon, O.; Kasdin, N. J.; Kern, B. D.; Lyon, R.; Mawet, D.; Moody, D.; Samuele, R.; Serabyn, E.; Sirbu, D.; Trauger, J.


    We present and compare experimental results in high contrast imaging representing the state of the art in coronagraph and starshade technology. These experiments have been undertaken with the goal of demonstrating the capability of detecting Earth-like planets around nearby Sun-like stars. The contrast of an Earth seen in reflected light around a Sun-like star would be about 1.2 x 10(exp -10). Several of the current candidate technologies now yield raw contrasts of 1.0 x 10(exp -9) or better, and so should enable the detection of Earths, assuming a gain in sensitivity in post-processing of a factor of 10. We present results of coronagraph and starshade experiments conducted at visible and infrared wavelengths. Cross-sections of dark fields are directly compared as a function of field angle and bandwidth. The strength and differences of the techniques are compared.

  20. Listenings of the image: the resultants of sound in the semiotic components of the visual language

    Wander Lourenço da Silva


    Full Text Available This study analyzes the communicational and aesthetic effects produced in the relationship between the image and sound elements of the films Rosso come ilcielo by Cristiano Bortone, and A Clockwork Orange by Stanley Kubrick. The theoretical framework comes from thesound and listening modes included in Theory of Film Sound Production proposed by Michel Chion and they are related to semiotic bases of C.S. Peirce. Also used is Hans Belting’s concept of endogenous images, the contributions of Vilém Flusser about the construction of mental images, and concepts of aesthetic categories treated by Umberto Eco and Sánches Vazquez. Analyzing some sequences according to the wiretaps reduced, causal, and semantics, we can say that the sound adds important elements to the scene that contribute to the final result, of communicational or aesthetic value. It is concluded, in Rosso come ilcielo, the sonorous code effectively contributes to the enhancement of synesthetic relations of the film, besides acting as an element that generates sense in the narrative as it is put as the main element in building of the mental imagery at times that the plot deals with the impairment of the sense of sight. In A Clockwork Orange, it is concluded that the sonorous component is responsible for generating of the ambiguity present in most of the film, especially in times of application of civil and system violence. It can be said that in this film, music selection was instrumental in adding to the scene elements in contrast to the imagery, thus producing a sense of the grotesque, enhanced by the mixture of pleasure and horror and sometimes by the presence of the comic.  

  1. SU-E-J-06: Additional Imaging Guidance Dose to Patient Organs Resulting From X-Ray Tubes Used in CyberKnife Image Guidance System

    Sullivan, A; Ding, G [Vanderbilt University, Nashville, TN (United States)


    Purpose: The use of image-guided radiation therapy (IGRT) has become increasingly common, but the additional radiation exposure resulting from repeated image guidance procedures raises concerns. Although there are many studies reporting imaging dose from different image guidance devices, imaging dose for the CyberKnife Robotic Radiosurgery System is not available. This study provides estimated organ doses resulting from image guidance procedures on the CyberKnife system. Methods: Commercially available Monte Carlo software, PCXMC, was used to calculate average organ doses resulting from x-ray tubes used in the CyberKnife system. There are seven imaging protocols with kVp ranging from 60 – 120 kV and 15 mAs for treatment sites in the Cranium, Head and Neck, Thorax, and Abdomen. The output of each image protocol was measured at treatment isocenter. For each site and protocol, Adult body sizes ranging from anorexic to extremely obese were simulated since organ dose depends on patient size. Doses for all organs within the imaging field-of-view of each site were calculated for a single image acquisition from both of the orthogonal x-ray tubes. Results: Average organ doses were <1.0 mGy for every treatment site and imaging protocol. For a given organ, dose increases as kV increases or body size decreases. Higher doses are typically reported for skeletal components, such as the skull, ribs, or clavicles, than for softtissue organs. Typical organ doses due to a single exposure are estimated as 0.23 mGy to the brain, 0.29 mGy to the heart, 0.08 mGy to the kidneys, etc., depending on the imaging protocol and site. Conclusion: The organ doses vary with treatment site, imaging protocol and patient size. Although the organ dose from a single image acquisition resulting from two orthogonal beams is generally insignificant, the sum of repeated image acquisitions (>100) could reach 10–20 cGy for a typical treatment fraction.

  2. Image Analysis for Cosmology: Results from the GREAT10 Star Challenge

    Kitching, T D; Gill, M; Heymans, C; Massey, R; Witherick, D; Courbin, F; Georgatzis, K; Gentile, M; Gruen, D; Kilbinger, M; Li, G L; Mariglis, A P; Meylan, G; Storkey, A; Xin, B


    We present the results from the first public blind PSF reconstruction challenge, the GRavitational lEnsing Accuracy Testing 2010 (GREAT10) Star Challenge. Reconstruction of a spatially varying PSF, sparsely sampled by stars, at non-star positions is a critical part in the image analysis for weak lensing where inaccuracies in the modelled ellipticity and size-squared can impact the ability to measure the shapes of galaxies. This is of importance because weak lensing is a particularly sensitive probe of dark energy, and can be used to map the mass distribution of large scale structure. Participants in the challenge were presented with 27,500 stars over 1300 images subdivided into 26 sets, where in each set a category change was made in the type or spatial variation of the PSF. Thirty submissions were made by 9 teams. The best methods reconstructed the PSF with an accuracy of ~0.00025 in ellipticity and ~0.00074 in size squared. For a fixed pixel scale narrower PSFs were found to be more difficult to model than ...

  3. Diffusion tensor imaging and tractography for assessment of renal allograft dysfunction - initial results

    Hueper, Katja; Gutberlet, M.; Rodt, T.; Wacker, F.; Galanski, M.; Hartung, D. [Institute for Diagnostic and Interventional Radiology, Hannover Medical School - Germany, Hannover (Germany); Gwinner, W. [Clinic for Nephrology, Hannover Medical School - Germany, Hannover (Germany); Lehner, F. [Clinic for General, Abdominal and Transplant Surgery, Hannover Medical School - Germany, Hannover (Germany)


    To evaluate MR diffusion tensor imaging (DTI) as non-invasive diagnostic tool for detection of acute and chronic allograft dysfunction and changes of organ microstructure. 15 kidney transplanted patients with allograft dysfunction and 14 healthy volunteers were examined using a fat-saturated echo-planar DTI-sequence at 1.5 T (6 diffusion directions, b = 0, 600 s/mm{sup 2}). Mean apparent diffusion coefficient (ADC) and mean fractional anisotropy (FA) were calculated separately for the cortex and for the medulla and compared between healthy and transplanted kidneys. Furthermore, the correlation between diffusion parameters and estimated GFR was determined. The ADC in the cortex and in the medulla were lower in transplanted than in healthy kidneys (p < 0.01). Differences were more distinct for FA, especially in the renal medulla, with a significant reduction in allografts (p < 0.001). Furthermore, in transplanted patients a correlation between mean FA in the medulla and estimated GFR was observed (r = 0.72, p < 0.01). Tractography visualized changes in renal microstructure in patients with impaired allograft function. Changes in allograft function and microstructure can be detected and quantified using DTI. However, to prove the value of DTI for standard clinical application especially correlation of imaging findings and biopsy results is necessary. (orig.)

  4. Preliminary results of equation of state measurements using imaging x-ray Thomson spectrometer

    Belancourt, Patrick; Theobald, Wolfgang; Keiter, Paul; Collins, Timothy; Bonino, Mark; Kozlowski, Pawel; Drake, Paul; University of Michigan Team; LaboratoryLaser Energetics Team; University of Oxford Team


    Understanding the equation of state of materials under shocked conditions is important for laboratory astrophysics and high-energy-density physics experiments. The goal of the experiments discussed here is to create a platform for equation of state measurements in shocked foams on Omega EP. The target of interest for these experiments is shocked carbonized resorcinol formaldehyde foam with an initial density of 0.34 g/cc. Lasers irradiate an ablator, driving a shock into the foam. Plasma conditions ahead of the shock, at the shock and behind the shock are diagnosed using the imaging x-ray Thomson spectrometer (IXTS). The IXTS is capable of spectrally resolving the scattered x-ray beam while imaging in one spatial dimension. Preliminary results from these experiments will be shown. This work is funded by the U.S. Department of Energy, through the NNSA-DS and SC-OFES Joint Program in High-Energy-Density Laboratory Plasmas, grant number DE-NA0001840, and the National Laser User Facility Program, Grant Number DE-NA0000850, and through the Laboratory for Laser Energetics, University of Rochester by the NNSA/OICF under Cooperative Agreement No. DE-FC52-08NA28302.

  5. Preliminary results of absolute wavelength calibration of imaging X-ray crystal spectrometer on EAST

    Pan, Xiayun [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); University of Science and Technology of China, Hefei 230026 (China); Wang, Fudi [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Chen, Jun [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); University of Science and Technology of China, Hefei 230026 (China); Lyu, Bo, E-mail: [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Li, Yingying; Fu, Jia; Xu, Liqing [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Shi, Yuejiang [University of Science and Technology of China, Hefei 230026 (China); Department of Nuclear Engineering, Seoul National University, Seoul 151-742 (Korea, Republic of); Ye, Minyou [University of Science and Technology of China, Hefei 230026 (China); Wan, Baonian [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China)


    Highlights: • The absolute wavelength calibration method for X-ray crystal spectrometer using X-ray fluorescence of the appropriate materials was first tested on EAST, and the preliminary experimental results were obtained. • The experimental results were thoroughly discussed and suggestion for further improvements of the experimental arrangement was proposed. • Rotation calibration of X-ray crystal spectrometer on EAST using MHD frequency was presented when the absolute wavelength calibration method is unavailable currently. - Abstract: Imaging X-ray crystal spectrometers (XCS) are currently operating on several major tokamaks to provide profiles of ion temperature and rotation velocity. In order to acquire absolute rotation velocity, several indirect methods were pursued previously, however the direct and effective method is to use known X-ray lines for wavelength calibration. One way to produce standard spectral lines is X-ray fluorescence, which could be excited by X-rays from tokamak plasmas. As part of the upgrade of XCS system on EAST, wavelength calibration was studied using cadmium's L-shell lines, namely Lα{sub 1} line (3.9564 Å) and Lα{sub 2} line (3.9650 Å) as the reference wavelength. The Geant 4 code was used to optimize foil thickness to achieve a reasonable X-ray fluorescence intensity. The Cd foil was placed between the beryllium window and crystal and could be retracted to provide in situ wavelength calibration. The detailed arrangement and preliminary wavelength calibration results of imaging X-ray crystal spectrometer on EAST are presented, plus the calibration using MHD frequency.

  6. Biochemical imaging of cervical intervertebral discs with glycosaminoglycan chemical exchange saturation transfer magnetic resonance imaging: feasibility and initial results

    Schleich, Christoph; Mueller-Lutz, Anja; Zimmermann, Lisa; Boos, Johannes; Wittsack, Hans-Joerg; Antoch, Gerald; Miese, Falk [Department of Diagnostic and Interventional Radiology, University Dusseldorf, Medical Faculty, Dusseldorf (Germany); Schmitt, Benjamin [Siemens Ltd. Australia, Healthcare Sector, Macquarie Park, NSW (Australia)


    To evaluate glycosaminoglycan chemical exchange saturation transfer (gagCEST) imaging at 3T in the assessment of the GAG content of cervical IVDs in healthy volunteers. Forty-two cervical intervertebral discs of seven healthy volunteers (four females, three males; mean age: 21.4 ± 1.4 years; range: 19-24 years) were examined at a 3T MRI scanner in this prospective study. The MRI protocol comprised standard morphological, sagittal T2 weighted (T2w) images to assess the magnetic resonance imaging (MRI) based grading system for cervical intervertebral disc degeneration (IVD) and biochemical imaging with gagCEST to calculate a region-of-interest analysis of nucleus pulposus (NP) and annulus fibrosus (AF). GagCEST of cervical IVDs was technically successful at 3T with significant higher gagCEST values in NP compared to AF (1.17 % ± 1.03 % vs. 0.79 % ± 1.75 %; p = 0.005). We found topological differences of gagCEST values of the cervical spine with significant higher gagCEST effects in lower IVDs (r = 1; p = 0). We could demonstrate a significant, negative correlation between gagCEST values and cervical disc degeneration of NP (r = -0.360; p = 0.019). Non-degenerated IVDs had significantly higher gagCEST effects compared to degenerated IVDs in NP (1.76 % ± 0.92 % vs. 0.52 % ± 1.17 %; p < 0.001). Biochemical imaging of cervical IVDs is feasible at 3T. GagCEST analysis demonstrated a topological GAG distribution of the cervical spine. The depletion of GAG in the NP with increasing level of morphological degeneration can be assessed using gagCEST imaging. (orig.)

  7. 基于广义似然比的小波域 SAR 图像相干斑抑制算法%Generalized Likelihood Ratio Based SAR Image Speckle Suppression Algorithm in Wavelet Domain

    侯建华; 刘欣达; 陈稳; 陈少波


    A Bayes shrinkage formula is derived under the framework of joint detection and estimation theory, and a wavelet SAR image despeckling algorithm is realized based on generalized likelihood ratio.Firstly, redundant wavelet transform is performed directly to the original speckled SAR images, and binary mask is obtained for each wavelet coefficient.We use scale exponential distribution and Gamma distribution, respectively, to model the likelihood conditional probability of speckle noise and useful signal.According to the mask, the parameters of the two modes are estimated by maximum likelihood estimation method, and thus the likelihood conditional probability ratio is calculated.Experiment results show that the proposed method can effectively filter the speckle noise, and at the same time preserve the image details as possible.Satisfactory results are achieved on both synthetically speckled images and real SAR images.%在联合检测与估计理论框架下推导出了Bayes萎缩函数表达式,并提出了一种基于广义似然比的小波域SAR图像去斑算法。该算法对含斑SAR图像直接做冗余小波变换,求出小波系数所对应的二值掩模;对相干斑噪声和有用信号的似然条件概率分别建模为尺度指数分布和Gamma分布,根据二值掩模信息,采用最大似然估计得到两种模型的参数并计算似然条件概率比。实验结果表明:文中所给算法在有效滤除斑点噪声的同时,也较好地保持了图像的细节信息,在对人工加斑图像和多幅实际SAR图像的处理中获得了令人满意的结果。

  8. Dynamic contrast-enhanced magnetic resonance imaging parameters correlate with advanced revised-ISS and angiopoietin-1/angiopoietin-2 ratio in patients with multiple myeloma.

    Terpos, Evangelos; Matsaridis, Dimitris; Koutoulidis, Vassilis; Zagouri, Flora; Christoulas, Dimitrios; Fontara, Sophia; Panourgias, Evangelia; Gavriatopoulou, Maria; Kastritis, Efstathios; Dimopoulos, Meletios A; Moulopoulos, Lia A


    The aim of the study was to assess the value of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in patients with newly diagnosed multiple myeloma (MM) who were treated with novel anti-myeloma agents. We studied 60 previously untreated MM patients at diagnosis, 14 with smoldering MM (SMM) and 5 with MGUS. All patients underwent MRI of the thoracolumbar spine and pelvis before the administration of any kind of therapy, and DCE-MRI was performed. The MRI perfusion parameters evaluated were wash-in (WIN), washout (WOUT), time-to-peak (TTPK), time-to-maximum slope (TMSP), and the WIN/TMSP ratio. The following serum levels of angiogenic cytokines were measured on the day of MRI: VEGF, angiogenin (Ang), angiopoietin-1 (Angp-1), and -2 (Angp-2). Symptomatic MM patients had increased WIN compared to SMM (p ISS. Patients with R-ISS-3 had lower TTPK median value (23 s, range 18-29 s) compared to patients with R-ISS-2 (48 s, range 27-68 s) and patients with R-ISS-1 MM (54 s, range 42-76 s; p ANOVA = 0.01). A subset of patients with low TTPK (lower quartile) had shorter time to progression compared to all other patients. These data suggest that certain DCE-MRI parameters correlate with R-ISS and adverse prognostic features of angiogenesis, such as the ratio of Angp-1/Angp-2.

  9. Primary progressive aphasia patients evaluated using diffusion tensor imaging and voxel based volumetry-preliminary results

    Fábio Pascotto de Oliveira


    Full Text Available There are individuals who have a progressive language deficit without presenting cognitive deficits in other areas. One of the diseases related to this presentation is primary progressive aphasia (PPA. OBJECTIVE: Identify by means of diffusion tensor imaging (DTI and measurements of cortical volume, brain areas that lead to dysphasia when presenting signs of impaired connectivity or reduced volume. METHOD: Four patients with PPA were evaluated using DTI, and measurements of cortical volumes in temporal areas. These patients were compared with two normal volunteers. RESULTS: There is a trend to a difference in the number and volume of related fibers between control group and patients with PPA. Comparing cortical volumes in temporal areas between groups yielded a trend to a smaller volume in PPA patients. CONCLUSION: Patients with PPA have a trend to impairment in cortical and subcortical levels regarding relevant areas.

  10. First results of a Double-SOI pixel chip for X-ray imaging

    Lu, Yunpeng; Ouyang, Qun; Arai, Yasuo; Liu, Yi; Wu, Zhigang; Zhou, Yang


    Aiming at low energy X-ray imaging, a prototype chip based on Double-SOI process was designed and tested. The sensor and pixel circuit were characterized. The long lasting crosstalk issue in SOI technology was understood. The operation of pixel was verified with a pulsed infrared laser beam. The depletion of sensor revealed by signal amplitudes is consistent with the one revealed by I-V curve. An s-curve fitting resulted in a sigma of 153 e- among which equivalent noise charge (ENC) contributed 113 e-. It's the first time that the crosstalk issue in SOI technology was solved and a counting type SOI pixel demonstrated the detection of low energy radiation quantitatively.

  11. Image-Based Visual Servoing for Manipulation Via Predictive Control – A Survey of Some Results

    Corneliu Lazăr


    Full Text Available In this paper, a review of predictive control algorithms developed by the authors for visual servoing of robots in manipulation applications is presented. Using these algorithms, a control predictive framework was created for image-based visual servoing (IBVS systems. Firstly, considering the point features, in the year 2008 we introduced an internal model predictor based on the interaction matrix. Secondly, distinctly from the set-point trajectory, we introduced in 2011 the reference trajectory using the concept from predictive control. Finally, minimizing a sum of squares of predicted errors, the optimal input trajectory was obtained. The new concept of predictive control for IBVS systems was employed to develop a cascade structure for motion control of robot arms. Simulation results obtained with a simulator for predictive IBVS systems are also presented.

  12. The Lyman alpha reference sample. II. Hubble space telescope imaging results, integrated properties, and trends

    Hayes, Matthew; Östlin, Göran; Duval, Florent; Sandberg, Andreas; Guaita, Lucia; Melinder, Jens; Rivera-Thorsen, Thøger [Department of Astronomy, Oskar Klein Centre, Stockholm University, AlbaNova University Centre, SE-106 91 Stockholm (Sweden); Adamo, Angela [Max Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg (Germany); Schaerer, Daniel [Université de Toulouse, UPS-OMP, IRAP, F-31000 Toulouse (France); Verhamme, Anne; Orlitová, Ivana [Geneva Observatory, University of Geneva, 51 Chemin des Maillettes, CH-1290 Versoix (Switzerland); Mas-Hesse, J. Miguel; Otí-Floranes, Héctor [Centro de Astrobiología (CSIC-INTA), Departamento de Astrofísica, P.O. Box 78, E-28691 Villanueva de la Cañada (Spain); Cannon, John M.; Pardy, Stephen [Department of Physics and Astronomy, Macalester College, 1600 Grand Avenue, Saint Paul, MN 55105 (United States); Atek, Hakim [Laboratoire dAstrophysique, École Polytechnique Fédérale de Lausanne (EPFL), Observatoire, CH-1290 Sauverny (Switzerland); Kunth, Daniel [Institut d' Astrophysique de Paris, UMR 7095, CNRS and UPMC, 98 bis Bd Arago, F-75014 Paris (France); Laursen, Peter [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen (Denmark); Herenz, E. Christian, E-mail: [Leibniz-Institut für Astrophysik (AIP), An der Sternwarte 16, D-14482 Potsdam (Germany)


    We report new results regarding the Lyα output of galaxies, derived from the Lyman Alpha Reference Sample, and focused on Hubble Space Telescope imaging. For 14 galaxies we present intensity images in Lyα, Hα, and UV, and maps of Hα/Hβ, Lyα equivalent width (EW), and Lyα/Hα. We present Lyα and UV radial light profiles and show they are well-fitted by Sérsic profiles, but Lyα profiles show indices systematically lower than those of the UV (n ≈ 1-2 instead of ≳ 4). This reveals a general lack of the central concentration in Lyα that is ubiquitous in the UV. Photometric growth curves increase more slowly for Lyα than the far ultraviolet, showing that small apertures may underestimate the EW. For most galaxies, however, flux and EW curves flatten by radii ≈10 kpc, suggesting that if placed at high-z only a few of our galaxies would suffer from large flux losses. We compute global properties of the sample in large apertures, and show total Lyα luminosities to be independent of all other quantities. Normalized Lyα throughput, however, shows significant correlations: escape is found to be higher in galaxies of lower star formation rate, dust content, mass, and nebular quantities that suggest harder ionizing continuum and lower metallicity. Six galaxies would be selected as high-z Lyα emitters, based upon their luminosity and EW. We discuss the results in the context of high-z Lyα and UV samples. A few galaxies have EWs above 50 Å, and one shows f{sub esc}{sup Lyα} of 80%; such objects have not previously been reported at low-z.

  13. Level 2 processing for the imaging Fourier transform spectrometer GLORIA: derivation and validation of temperature and trace gas volume mixing ratios from calibrated dynamics mode spectra

    J. Ungermann


    Full Text Available The Gimballed Limb Observer for Radiance Imaging of the Atmosphere (GLORIA is an airborne infrared limb imager combining a two-dimensional infrared detector with a Fourier transform spectrometer. It was operated aboard the new German Gulfstream G550 High Altitude LOng Range (HALO research aircraft during the Transport And Composition in the upper Troposphere/lowermost Stratosphere (TACTS and Earth System Model Validation (ESMVAL campaigns in summer 2012. This paper describes the retrieval of temperature and trace gas (H2O, O3, HNO3 volume mixing ratios from GLORIA dynamics mode spectra that are spectrally sampled every 0.625 cm−1. A total of 26 integrated spectral windows are employed in a joint fit to retrieve seven targets using consecutively a fast and an accurate tabulated radiative transfer model. Typical diagnostic quantities are provided including effects of uncertainties in the calibration and horizontal resolution along the line of sight. Simultaneous in situ observations by the Basic Halo Measurement and Sensor System (BAHAMAS, the Fast In-situ Stratospheric Hygrometer (FISH, an ozone detector named Fairo, and the Atmospheric chemical Ionization Mass Spectrometer (AIMS allow a validation of retrieved values for three flights in the upper troposphere/lowermost stratosphere region spanning polar and sub-tropical latitudes. A high correlation is achieved between the remote sensing and the in situ trace gas data, and discrepancies can to a large extent be attributed to differences in the probed air masses caused by different sampling characteristics of the instruments. This 1-D processing of GLORIA dynamics mode spectra provides the basis for future tomographic inversions from circular and linear flight paths to better understand selected dynamical processes of the upper troposphere and lowermost stratosphere.

  14. Extended use of ISO 15739 incremental signal-to-noise ratio as reliability criterion for multiple-slope wide dynamic range image capture

    Hertel, Dirk


    In the emerging field of automotive vision, video capture is the critical front-end of driver assistance and active safety systems. Previous photospace measurements have shown that light levels in natural traffic scenes may contain an extremely wide intra-scene intensity range. This requires the camera to have a wide dynamic range (WDR) for it to adapt quickly to changing lighting conditions and to reliably capture all scene detail. Multiple-slope CMOS technology offers a cost-effective way of adaptively extending dynamic range by partially resetting (recharging) the CMOS pixel once or more often within each frame time. This avoids saturation and leads to a response curve with piecewise linear slopes of progressively increasing compression. It was observed that the image quality from multiple-slope image capture is strongly dependent on the control (height and time) of each reset barrier. As compression and thus dynamic range increase there is a trade-off against contrast and detail loss. Incremental signal-to-noise ratio (iSNR) is proposed in ISO 15739 for determining dynamic range. Measurements and computer simulations revealed that the observed trade-off between WDR extension and the loss of local detail could be explained by a drop in iSNR at each reset point. If a reset barrier is not optimally placed then iSNR may drop below the detection limit so that an 'iSNR hole' appears in the dynamic range. Thus ISO 15739 iSNR has gained extended utility: it not only measures the dynamic range limits but also defines dynamic range as the intensity range where detail detection is reliable. It has become a critical criterion when designing adaptive barrier control algorithms that maximize dynamic range while maintaining the minimum necessary level of detection reliability.

  15. [Health care resources and mortality as assessed by "the empirical Bayes estimate of standardized mortality ratio": results for municipalities in Japan].

    Otsubo, Koichi; Yamaoka, Kazue; Yokoyama, Tetsuji; Takahashi, Kunihiko; Nishikawa, Masako; Tango, Toshiro


    The standardized mortality ratio (SMR) is frequently used to compare health status among different populations. However, SMR could be biased when based upon communities with small population size such as towns and wards and comparison of SMRs in such cases is not appropriate. The "empirical Bayes estimate of standardized mortality ratio" (EBSMR) is a useful alternative index for comparing mortalities among small populations. The objective of the present study was to use the EBSMR to clarify the relationships between health care resources and mortalities in 3,360 municipalities in Japan. Health care resource data (number of physicians, number of general clinics, number of general sickbeds, and number of emergency hospitals) and socioeconomic factors (population, birth rate, aged households, marital rate, divorce rate, taxable income per individual under taxes duty, unemployment, secondary, tertiary industrial employment and prefecture) were obtained from officially published reports. EBSMRs for all causes, cerebrovascular disease, heart disease, acute myocardial infarction, and malignant neoplasms were calculated from the 1997-2001 vital statistic records. Multiple regression analysis was used to examine the relationships between EBSMRs and the variables representing health care resources and socioeconomic factors as covariates. Some of the variables were log-transformed to normalize the distribution of variables. The correlation between number of physicians and general sickbeds was very high (Pearson's r = 0.776). So, we excluded the number of general sickbeds. Some of the EBSMRs were inversely associated with the number of physicians per person (all causes in males (beta = -0.042, P = 0.024) and females (beta = -0.150, P < 0.001), cerebrovascular disease in females (beta = -0.074, P < 0.001), heart disease in males (beta = -0.066, P < 0.001) and females (beta = - 0.087, P < 0.001), acute myocardial infarction in females (beta = -0.061, P = 0.003), and malignant

  16. Validation of an axial flow blood pump: computational fluid dynamics results using particle image velocimetry.

    Su, Boyang; Chua, Leok Poh; Wang, Xikun


    A magnetically suspended axial flow blood pump is studied experimentally in this article. The pump casing enclosed a three-blade straightener, a two-blade impeller shrouded by a permanent magnet-embedded cylinder, and a three-blade diffuser. The internal flow fields were simulated earlier using computational fluid dynamics (CFD), and the pump characteristic curves were determined. The simulation results showed that the internal flow field was basically streamlined, except the diffuser region. Particle image velocimetry (PIV) measurement of the 1:1 pump model was conducted to validate the CFD result. In order to ensure the optical access, an acrylic prototype was fabricated with the impeller driven by a servomotor instead, as the magnet is opaque. In addition to the transparent model, the blood analog fluid with the refractive index close to that of acrylic was used to avoid refraction. According to the CFD results, the axial flow blood pump could generate adequate pressure head at the rotating speed of 9500rpm and flow rate of 5L/min, and the same flow condition was applied during the PIV measurement. Through the comparisons, it was found that the experimental results were close to those obtained by CFD and had thus validated the CFD model, which could complement the limitation of the measurement in assessing the more detailed flow fields of the axial flow pump.

  17. Clot lysis time and the risk of myocardial infarction and ischaemic stroke in young women; results from the RATIO case-control study

    Siegerink, Bob; Meltzer, Mirjam E.; de Groot, Philip G.; Algra, Ale; Lisman, Ton; Rosendaal, Frits R.


    Reduced overall fibrinolytic capacity increases the risk of myocardial infarction (MI), as demonstrated in studies with predominantly male participants. We determined the influence of altered fibrinolysis on the risk of MI and ischaemic stroke (IS) in young women. The RATIO (Risk of Arterial Thrombo

  18. Quantitative imaging of volcanic plumes — Results, needs, and future trends

    Platt, Ulrich; Lübcke, Peter; Kuhn, Jonas; Bobrowski, Nicole; Prata, Fred; Burton, Mike; Kern, Christoph


    Recent technology allows two-dimensional “imaging” of trace gas distributions in plumes. In contrast to older, one-dimensional remote sensing techniques, that are only capable of measuring total column densities, the new imaging methods give insight into details of transport and mixing processes as well as chemical transformation within plumes. We give an overview of gas imaging techniques already being applied at volcanoes (SO2cameras, imaging DOAS, FT-IR imaging), present techniques where first field experiments were conducted (LED-LIDAR, tomographic mapping), and describe some techniques where only theoretical studies with application to volcanology exist (e.g. Fabry–Pérot Imaging, Gas Correlation Spectroscopy, bi-static LIDAR). Finally, we discuss current needs and future trends in imaging technology.

  19. Analyzing Medical Image Search Behavior: Semantics and Prediction of Query Results.

    De-Arteaga, Maria; Eggel, Ivan; Kahn, Charles E; Müller, Henning


    Log files of information retrieval systems that record user behavior have been used to improve the outcomes of retrieval systems, understand user behavior, and predict events. In this article, a log file of the ARRS GoldMiner search engine containing 222,005 consecutive queries is analyzed. Time stamps are available for each query, as well as masked IP addresses, which enables to identify queries from the same person. This article describes the ways in which physicians (or Internet searchers interested in medical images) search and proposes potential improvements by suggesting query modifications. For example, many queries contain only few terms and therefore are not specific; others contain spelling mistakes or non-medical terms that likely lead to poor or empty results. One of the goals of this report is to predict the number of results a query will have since such a model allows search engines to automatically propose query modifications in order to avoid result lists that are empty or too large. This prediction is made based on characteristics of the query terms themselves. Prediction of empty results has an accuracy above 88%, and thus can be used to automatically modify the query to avoid empty result sets for a user. The semantic analysis and data of reformulations done by users in the past can aid the development of better search systems, particularly to improve results for novice users. Therefore, this paper gives important ideas to better understand how people search and how to use this knowledge to improve the performance of specialized medical search engines.

  20. Offset-sparsity decomposition for enhancement of color microscopic image of stained specimen in histopathology: further results

    Kopriva, Ivica; Popović Hadžija, Marijana; Hadžija, Mirko; Aralica, Gorana


    Recently, novel data-driven offset-sparsity decomposition (OSD) method was proposed by us to increase colorimetric difference between tissue-structures present in the color microscopic image of stained specimen in histopathology. The OSD method performs additive decomposition of vectorized spectral images into image-adapted offset term and sparse term. Thereby, the sparse term represents an enhanced image. The method was tested on images of the histological slides of human liver stained with hematoxylin and eosin, anti-CD34 monoclonal antibody and Sudan III. Herein, we present further results related to increase of colorimetric difference between tissue structures present in the images of human liver specimens with pancreatic carcinoma metastasis stained with Gomori, CK7, CDX2 and LCA, and with colon carcinoma metastasis stained with Gomori, CK20 and PAN CK. Obtained relative increase of colorimetric difference is in the range [19.36%, 103.94%].

  1. Effect of the gastrointestinal environment on pH homeostasis of Lactobacillus plantarum and Lactobacillus brevis cells as measured by real-time fluorescence ratio-imaging microscopy.

    Ramos, Cíntia Lacerda; Thorsen, Line; Ryssel, Mia; Nielsen, Dennis S; Siegumfeldt, Henrik; Schwan, Rosane Freitas; Jespersen, Lene


    In the present work, an in vitro model of the gastrointestinal tract (GIT) was developed to obtain real-time observations of the pH homeostasis of single cells of probiotic Lactobacillus spp. strains as a measure of their physiological state. Changes in the intracellular pH (pHi) were determined using fluorescence ratio imaging microscopy (FRIM) for potential probiotic strains of Lactobacillus plantarum UFLA CH3 and Lactobacillus brevis UFLA FFC199. Heterogeneous populations were observed, with pHi values ranging from 6.5 to 7.5, 3.5 to 5.6 and 6.5 to 8.0 or higher during passage of saliva (pH 6.4), gastric (pH 3.5) and intestinal juices (pH 6.4), respectively. When nutrients were added to gastric juice, the isolate L. brevis significantly decreased its pH(i) closer to the extracellular pH (pH(ex)) than in gastric juice without nutrients. This was not the case for L. plantarum. This study is the first to produce an in vitro GIT model enabling real-time monitoring of pH homeostasis of single cells in response to the wide range of pH(ex) of the GIT. Furthermore, it was possible to observe the heterogeneous response of single cells. The technique can be used to determine the survival and physiological conditions of potential probiotics and other microorganisms during passage through the GIT.

  2. Effect of the gastrointestinal environment on pH homeostasis of Lactobacillus plantarum and Lactobacillus brevis cells as measured by real-time fluorescence ratio-imaging microscopy

    Ramos, Cíntia Lacerda; Thorsen, Line; Ryssel, Mia;


    using fluorescence ratio imaging microscopy (FRIM) for potential probiotic strains of Lactobacillus plantarum UFLA CH3 and Lactobacillus brevis UFLA FFC199. Heterogeneous populations were observed, with pHi values ranging from 6.5 to 7.5, 3.5 to 5.6 and 6.5 to 8.0 or higher during passage of saliva (p......In the present work, an in vitro model of the gastrointestinal tract (GIT) was developed to obtain real-time observations of the pH homeostasis of single cells of probiotic Lactobacillus spp. strains as a measure of their physiological state. Changes in the intracellular pH (pHi) were determined......H 6.4), gastric (pH 3.5) and intestinal juices (pH 6.4), respectively. When nutrients were added to gastric juice, the isolate L. brevis significantly decreased its pHi closer to the extracellular pH (pHex) than in gastric juice without nutrients. This was not the case for L. plantarum. This study...

  3. Report on recent results of the PERCIVAL soft X-ray imager

    Khromova, A.; Cautero, G.; Giuressi, D.; Menk, R.; Pinaroli, G.; Stebel, L.; Correa, J.; Marras, A.; Wunderer, C. B.; Lange, S.; Tennert, M.; Niemann, M.; Hirsemann, H.; Smoljanin, S.; Reza, S.; Graafsma, H.; Göttlicher, P.; Shevyakov, I.; Supra, J.; Xia, Q.; Zimmer, M.; Guerrini, N.; Marsh, B.; Sedgwick, I.; Nicholls, T.; Turchetta, R.; Pedersen, U.; Tartoni, N.; Hyun, H. J.; Kim, K. S.; Rah, S. Y.; Hoenk, M. E.; Jewell, A. D.; Jones, T. J.; Nikzad, S.


    The PERCIVAL (Pixelated Energy Resolving CMOS Imager, Versatile And Large) soft X-ray 2D imaging detector is based on stitched, wafer-scale sensors possessing a thick epi-layer, which together with back-thinning and back-side illumination yields elevated quantum efficiency in the photon energy range of 125-1000 eV. Main application fields of PERCIVAL are foreseen in photon science with FELs and synchrotron radiation. This requires high dynamic range up to 105 ph @ 250 eV paired with single photon sensitivity with high confidence at moderate frame rates in the range of 10-120 Hz. These figures imply the availability of dynamic gain switching on a pixel-by-pixel basis and a highly parallel, low noise analog and digital readout, which has been realized in the PERCIVAL sensor layout. Different aspects of the detector performance have been assessed using prototype sensors with different pixel and ADC types. This work will report on the recent test results performed on the newest chip prototypes with the improved pixel and ADC architecture. For the target frame rates in the 10-120 Hz range an average noise floor of 14e- has been determined, indicating the ability of detecting single photons with energies above 250 eV. Owing to the successfully implemented adaptive 3-stage multiple-gain switching, the integrated charge level exceeds 4 · 106 e- or 57000 X-ray photons at 250 eV per frame at 120 Hz. For all gains the noise level remains below the Poisson limit also in high-flux conditions. Additionally, a short overview over the updates on an oncoming 2 Mpixel (P2M) detector system (expected at the end of 2016) will be reported.

  4. Diffusion-weighted Magnetic Resonance Imaging in the Diagnosis of Bone Tumors: Preliminary Results

    Yeliz Pekcevik


    Full Text Available Objective: The study aims to determine whether apparent diffusion coefficient (ADC can help differentiate benign and malignant bone tumors. Materials and Methods: From January 2012 to February 2013, we prospectively included 26 patients. Of these 15 patients were male and 11 were female; ranging in age from 8 to 76 years (mean age, 34.5 years. Diffusion-weighted magnetic resonance (MR imaging was obtained with a single-shot echo-planar imaging sequence using a 1.5T MR scanner. We grouped malignant lesions as primary, secondary, and primary tumor with chondroid matrix. The minimum ADC was measured in the tumors and mean minimum ADC values were selected for statistical analysis. ADC values were compared between malignant and benign tumors using the Mann-Whitney U-test and receiver operating curve analysis were done to determine optimal cut-off values. Results: The mean ADC values from the area with lowest ADC values of benign and malignant tumors were 1.99 ± 0.57 × 10−3 mm 2 /s and 1.02 ± 1.0 × 10−3 mm 2 /s, respectively. The mean minimum ADC values of benign and malignant tumors were statistically different (P = 0.029. With cut-off value of 1.37 (10−3 mm 2 /s, sensitivity was 77.8% and specificity was 82.4%, for distinguishing benign and malignant lesion. Benign and secondary malignant tumors showed statistically significant difference (P = 0.002. There was some overlap in ADC values between benign and malignant tumors. The mean minimum ADC values of benign and malignant chondroid tumors were high. Giant cell tumor, non-ossifying fibroma and fibrous dysplasia showed lower ADC values. Conclusion: Although there is some overlap, ADC values of benign and malignant bone tumors seem to be different. Further studies with larger patient groups are needed to find an optimal cut-off ADC value.

  5. Opportunity Microscopic Imager Results from the Western Rim of Endeavour Crater

    Herkenhoff, K. E.; Arvidson, R. E.; Mittlefehldt, D. W.; Sullivan, R. J.


    The Athena science payload on the Mars Exploration Rovers (MER Spirit and Opportunity) includes the Microscopic Imager (MI), a fixed focus close-up camera mounted on the instrument arm. The MI acquires images at a scale of 31 micrometers/pixel over a broad spectral range (400 to 700 nm) using only natural illumination of target surfaces. Radio signals from Spirit have not been received since March 2010, so attempts to communicate with that rover ceased in mid-2011. The Opportunity MI optics were contaminated by a global dust storm in 2007. That contamination continues to reduce the contrast of MI images, and is being monitored by occasionally imaging the sky.

  6. Comparing User-Assigned Terms with Indexer-Assigned Terms for Storage and Retrieval of Moving Images: Research Results.

    Turner, James M.


    Discussion of indexing moving image documents at the shot level focuses on a study conducted at the National Film Board of Canada. Popular terms supplied by users were compared with terms assigned by professional indexers in the source stockshot collection. Results suggest that indexing images using preiconographic (ofness) and iconographic…

  7. Combined chirp coded tissue harmonic and fundamental ultrasound imaging for intravascular ultrasound: 20-60 MHz phantom and ex vivo results.

    Park, Jinhyoung; Li, Xiang; Zhou, Qifa; Shung, K Kirk


    The application of chirp coded excitation to pulse inversion tissue harmonic imaging can increase signal to noise ratio. On the other hand, the elevation of range side lobe level, caused by leakages of the fundamental signal, has been problematic in mechanical scanners which are still the most prevalent in high frequency intravascular ultrasound imaging. Fundamental chirp coded excitation imaging can achieve range side lobe levels lower than -60dB with Hanning window, but it yields higher side lobes level than pulse inversion chirp coded tissue harmonic imaging (PI-CTHI). Therefore, in this paper a combined pulse inversion chirp coded tissue harmonic and fundamental imaging mode (CPI-CTHI) is proposed to retain the advantages of both chirp coded harmonic and fundamental imaging modes by demonstrating 20-60MHz phantom and ex vivo results. A simulation study shows that the range side lobe level of CPI-CTHI is 16dB lower than PI-CTHI, assuming that the transducer translates incident positions by 50μm when two beamlines of pulse inversion pair are acquired. CPI-CTHI is implemented for a proto-typed intravascular ultrasound scanner capable of combined data acquisition in real-time. A wire phantom study shows that CPI-CTHI has a 12dB lower range side lobe level and a 7dB higher echo signal to noise ratio than PI-CTHI, while the lateral resolution and side lobe level are 50μm finer and -3dB less than fundamental chirp coded excitation imaging respectively. Ex vivo scanning of a rabbit trachea demonstrates that CPI-CTHI is capable of visualizing blood vessels as small as 200μm in diameter with 6dB better tissue contrast than either PI-CTHI or fundamental chirp coded excitation imaging. These results clearly indicate that CPI-CTHI may enhance tissue contrast with less range side lobe level than PI-CTHI. Copyright © 2012 Elsevier B.V. All rights reserved.

  8. Cloud Base Height Measurements at Manila Observatory: Initial Results from Constructed Paired Sky Imaging Cameras

    Lagrosas, N.; Tan, F.; Antioquia, C. T.


    Fabricated all sky imagers are efficient and cost effective instruments for cloud detection and classification. Continuous operation of this instrument can result in the determination of cloud occurrence and cloud base heights for the paired system. In this study, a fabricated paired sky imaging system - consisting two commercial digital cameras (Canon Powershot A2300) enclosed in weatherproof containers - is developed in Manila Observatory for the purpose of determining cloud base heights at the Manila Observatory area. One of the cameras is placed on the rooftop of Manila Observatory and the other is placed on the rooftop of the university dormitory, 489m from the first camera. The cameras are programmed to simultaneously gather pictures every 5 min. Continuous operation of these cameras were implemented since the end of May of 2014 but data collection started end of October 2013. The data were processed following the algorithm proposed by Kassianov et al (2005). The processing involves the calculation of the merit function that determines the area of overlap of the two pictures. When two pictures are overlapped, the minimum of the merit function corresponds to the pixel column positions where the pictures have the best overlap. In this study, pictures of overcast sky prove to be difficult to process for cloud base height and were excluded from processing. The figure below shows the initial results of the hourly average of cloud base heights from data collected from November 2013 to July 2014. Measured cloud base heights ranged from 250m to 1.5km. These are the heights of cumulus and nimbus clouds that are dominant in this part of the world. Cloud base heights are low in the early hours of the day indicating low convection process during these times. However, the increase in the convection process in the atmosphere can be deduced from higher cloud base heights in the afternoon. The decrease of cloud base heights after 15:00 follows the trend of decreasing solar

  9. Biological image construction by using Raman radiation and Pca: preliminary results

    Martinez E, J. C. [IPN, Unidad Profesional Interdisciplinaria de Ingenieria, Campus Guanajuato, Av. Mineral de Valenciana 200, Col. Fracc. Industrial Puerto Interior, 36275 Silao, Guanajuato (Mexico); Cordova F, T. [Universidad de Guanajuato, DIC, Departamento de Ingenieria Fisica, Loma del Bosque No. 103, Col. Lomas del Campestre, 37150 Leon, Guanajuato (Mexico); Hugo R, V., E-mail: [Universidad de Guadalajara, Centro Universitario de Tonala, Morelos No. 180, 69584 Tonala, Jalisco (Mexico)


    Full text: In the last years, the Raman spectroscopy (Rs) technique has had some applications in the study and analysis of biological samples, due to it is able to detect concentrations or presence of certain organic and inorganic compounds of medical interest. In this work, raw data were obtained through measurements in selected points on a square regions in order to detect specific organic / inorganic compounds on biological samples. Gold nano stars samples were prepared and coated with membrane markers (CD 10+ and CD 19+) and diluted in leukemic B lymphocytes. Each data block was evaluated independently by the method of principal component analysis (Pca) in order to find representative dimensionless values (Cp) for each Raman spectrum in a specific coordinate. Each Cp was normalized in a range of 0-255 in order to generate a representative image of 8 bits of the region under study. Data acquisition was performed with Raman microscopy system Renishaw in Via in the range of 550 to 1700 cm-1 with a 785 nm laser source, with a power of 17 m W and 15 s of exposure time were used for each spectrum. In preliminary results could detect the presence of molecular markers CD 10+ and CD 19+ with gold nano stars and discrimination between both markers. The results suggest conducting studies with specific concentrations organic and inorganic materials. (Author)

  10. Random walks based multi-image segmentation: Quasiconvexity results and GPU-based solutions.

    Collins, Maxwell D; Xu, Jia; Grady, Leo; Singh, Vikas


    We recast the Cosegmentation problem using Random Walker (RW) segmentation as the core segmentation algorithm, rather than the traditional MRF approach adopted in the literature so far. Our formulation is similar to previous approaches in the sense that it also permits Cosegmentation constraints (which impose consistency between the extracted objects from ≥ 2 images) using a nonparametric model. However, several previous nonparametric cosegmentation methods have the serious limitation that they require adding one auxiliary node (or variable) for every pair of pixels that are similar (which effectively limits such methods to describing only those objects that have high entropy appearance models). In contrast, our proposed model completely eliminates this restrictive dependence -the resulting improvements are quite significant. Our model further allows an optimization scheme exploiting quasiconvexity for model-based segmentation with no dependence on the scale of the segmented foreground. Finally, we show that the optimization can be expressed in terms of linear algebra operations on sparse matrices which are easily mapped to GPU architecture. We provide a highly specialized CUDA library for Cosegmentation exploiting this special structure, and report experimental results showing these advantages.

  11. The Ring Imaging Cherenkov detector of the AMS experiment: test beam results with a prototype

    Arruda, Luísa; Goncalves, Patrícia; Pereira, Rui


    The Alpha Magnetic Spectrometer (AMS) to be installed on the International Space Station (ISS) will be equipped with a proximity Ring Imaging Cherenkov (RICH) detector for measuring the velocity and electric charge of the charged cosmic particles. This detector will contribute to the high level of redundancy required for AMS as well as to the rejection of albedo particles. Charge separation up to iron and a velocity resolution of the order of 0.1% for singly charged particles are expected. A RICH protoptype consisting of a detection matrix with 96 photomultiplier units, a segment of a conical mirror and samples of the radiator materials was built and its performance was evaluated. Results from the last test beam performed with ion fragments resulting from the collision of a 158 GeV/c/nucleon primary beam of indium ions (CERN SPS) on a lead target are reported. The large amount of collected data allowed to test and characterize different aerogel samples and the sodium fluoride radiator. In addition, the reflec...

  12. MAPTIP - Marine Aerosol Properties and Thermal Imager Performance : Summary and initial results

    Eijk, A.M.J. van; Leeuw, G. de; Jensen, D.R.


    The marine aerosol properties and thermal imager performance trial (MAPTIP) was conducted by NATO AC/243 Panel 04/RSG.8 and 04/RSG.5 in the Dutch coastal waters during the fall of 1993. The main objectives of the trial were (1) to assess marine boundary layer effects on thermal imaging systems and (

  13. Influence of Solid Target Reflectivity and Incident Angle on Depolarization Ratio and Reflected Energy from Polarized Lights: Experimental Results of the May 2008 Field Trial


    incident angle on depolarization ratio and reected energy from polarized lights is also provided. DRDC Valcartier TR 2008-394 i Résumé Des capteurs ...41.5 -22 10 Laiton Brass 10 -37.5 11 Aluminium Aluminum 26 -37.5 12 Acier "sand-blasté" Sandblasted steel 41.5 -37.5 13 Acier naturel Natural steel 10

  14. Quantitative measurement of hepatic fibrosis with gadoxetic acid-enhanced magnetic resonance imaging in patients with chronic hepatitis B infection: A comparative study on aspartate aminotransferase to platelet ratio index and fibrosis-4 index

    Lee, Guy Mok; Kim, Youe Ree; Cho, Eun Young; Lee, Young Hwan; Yoon, Kwon Ha [Wonkwang University School of Medicine, Iksan (Korea, Republic of); Ryu, Jong Hyun; Kim, Tae Hoon [Imaging Science Research Center, Wonkwang University, Iksan (Korea, Republic of)


    To quantitatively measure hepatic fibrosis on gadoxetic acid-enhanced magnetic resonance (MR) in chronic hepatitis B (CHB) patients and identify the correlations with aspartate aminotransferase-to-platelet ratio index (APRI) and fibrosis-4 index (FIB-4) values. This study on gadoxetic acid-enhanced 3T MR imaging included 81 patients with CHB infection. To quantitatively measure hepatic fibrosis, MR images were analyzed with an aim to identify inhomogeneous signal intensities calculated from a coefficient of variation (CV) map in the liver parenchyma. We also carried out a comparative analysis between APRI and FIB-4 based on metaregression results. The diagnostic performance of the CV map was evaluated using a receiver-operating characteristic (ROC) curve. In the MR images, the mean CV values in control, groups I, II, and III based on APRI were 4.08 ± 0.92, 4.24 ± 0.80, 5.64 ± 1.11, and 5.73 ± 1.28, respectively (p < 0.001). In CHB patients grouped by FIB-4, the mean CV values of groups A, B, and C were 4.22 ± 0.95, 5.40 ± 1.19, and 5.71 ± 1.17, respectively (p < 0.001). The mean CV values correlated well with APRI (r = 0.392, p < 0.001) and FIB-4 (r = 0.294, p < 0.001). In significant fibrosis group, ROC curve analysis yielded an area under the curve of 0.875 using APRI and 0.831 using FIB-4 in HB, respectively. Gadoxetic acid-enhanced MR imaging for calculating a CV map showed moderate correlation with APRI and FIB-4 values and could be employed to quantitatively measure hepatic fibrosis in patients with CHB.

  15. Defining the Optimal Planning Target Volume in Image-Guided Stereotactic Radiosurgery of Brain Metastases: Results of a Randomized Trial

    Kirkpatrick, John P., E-mail: [Department of Radiation Oncology, Duke University, Durham, North Carolina (United States); Department of Surgery, Duke University, Durham, North Carolina (United States); Wang, Zhiheng [Department of Radiation Oncology, Duke University, Durham, North Carolina (United States); Sampson, John H. [Department of Radiation Oncology, Duke University, Durham, North Carolina (United States); Department of Surgery, Duke University, Durham, North Carolina (United States); McSherry, Frances; Herndon, James E. [Department of Biostatistics and Bioinformatics, Duke University, Durham, North Carolina (United States); Allen, Karen J.; Duffy, Eileen [Department of Radiation Oncology, Duke University, Durham, North Carolina (United States); Hoang, Jenny K. [Department of Radiology, Duke University, Durham, North Carolina (United States); Chang, Zheng; Yoo, David S.; Kelsey, Chris R.; Yin, Fang-Fang [Department of Radiation Oncology, Duke University, Durham, North Carolina (United States)


    Purpose: To identify an optimal margin about the gross target volume (GTV) for stereotactic radiosurgery (SRS) of brain metastases, minimizing toxicity and local recurrence. Methods and Materials: Adult patients with 1 to 3 brain metastases less than 4 cm in greatest dimension, no previous brain radiation therapy, and Karnofsky performance status (KPS) above 70 were eligible for this institutional review board–approved trial. Individual lesions were randomized to 1- or 3- mm uniform expansion of the GTV defined on contrast-enhanced magnetic resonance imaging (MRI). The resulting planning target volume (PTV) was treated to 24, 18, or 15 Gy marginal dose for maximum PTV diameters less than 2, 2 to 2.9, and 3 to 3.9 cm, respectively, using a linear accelerator–based image-guided system. The primary endpoint was local recurrence (LR). Secondary endpoints included neurocognition Mini-Mental State Examination, Trail Making Test Parts A and B, quality of life (Functional Assessment of Cancer Therapy-Brain), radionecrosis (RN), need for salvage radiation therapy, distant failure (DF) in the brain, and overall survival (OS). Results: Between February 2010 and November 2012, 49 patients with 80 brain metastases were treated. The median age was 61 years, the median KPS was 90, and the predominant histologies were non–small cell lung cancer (25 patients) and melanoma (8). Fifty-five, 19, and 6 lesions were treated to 24, 18, and 15 Gy, respectively. The PTV/GTV ratio, volume receiving 12 Gy or more, and minimum dose to PTV were significantly higher in the 3-mm group (all P<.01), and GTV was similar (P=.76). At a median follow-up time of 32.2 months, 11 patients were alive, with median OS 10.6 months. LR was observed in only 3 lesions (2 in the 1 mm group, P=.51), with 6.7% LR 12 months after SRS. Biopsy-proven RN alone was observed in 6 lesions (5 in the 3-mm group, P=.10). The 12-month DF rate was 45.7%. Three months after SRS, no significant change in

  16. In-vivo imaging results with ultrasound tomography: report on an ongoing study at the Karmanos Cancer Institute

    Duric, Nebojsa; Littrup, Peter; Chandiwala-Mody, Priti; Li, Cuiping; Schmidt, Steven; Myc, Lukasz; Rama, Olsi; Bey-Knight, Lisa; Lupinacci, Jessica; Ranger, Bryan; Szczepanski, Amy; West, Erik


    Our laboratory has focused on the development of ultrasound tomography (UST) for breast imaging. To that end we have been developing and testing a clinical prototype in the Karmanos Cancer Institute's (KCI) breast center. The development of our prototype has been guided by clinical feedback from data accumulated from over 300 patients recruited over the last 4 years. Our techniques generate whole breast reflection images as well as images of the acoustic parameters of sound speed and attenuation. The combination of these images reveals major breast anatomy, including fat, parenchyma, fibrous stroma and masses. Fusion imaging, utilizing thresholding, is shown to visualize mass characterization and facilitates separation of cancer from benign masses. These results indicate that operator-independent whole-breast imaging and the detection and characterization of cancerous breast masses are feasible using acoustic tomography techniques. Analyses of the prototype images suggests that we can detect the variety of mass attributes noted by current ultrasound-BIRADS criteria, such as mass shape, acoustic mass properties and architecture of the tumor environment. These attributes help quantify current BIRADS criteria (e.g. "shadowing" or high attenuation) and provide greater possibilities for defining a unique signature of cancer. The potential for UST to detect and characterize breast masses was quantified using UST measurements of 86 masses from the most recent cohort of patients imaged with the latest version of our prototype. Our preliminary results suggest that the development of a formal predictive model, in support of larger future trials, is warranted.

  17. The Wendelstein three channel imager (3KK): alignment, commissioning, and first results

    Lang-Bardl, F.; Bender, R.; Goessl, C.; Grupp, F.; Hess, H.-J.; Kaminski, J.; Hodapp, K.; Hopp, U.; Jacobson, S.; Kravcar, H.; Monna, A.; Mitsch, W.; Schlichter, J.; Wegner, M.


    The Ludwig-Maximilians-Universität München operates an astrophysical observatory on the summit of Mt. Wendelstein which was equipped with a modern 2m-class robotic telescope in 20111-3. One of the two Nasmyth ports is designed to deliver the excellent (efficiently support observations of targets of opportunities like Gamma-Ray-bursts or efficient photometric redshift determination of sources identified by surveys like PanSTARS, Planck (SZ) or eROSITA. The covered wavelength range is 340 nm to 2.3 microns. The camera provides standard broadband filters (Sloan, Y, J, H, Ks) and 5 narrowband filters (OI, Hα, SII, H2, Brλ). The narrowband filters will enable deep studies of star forming regions. We present the final design of the camera, the assembly and alignment procedure performed in the laboratory before we transported the instrument to the observatory. We also show first results of the achieved on sky performance concerning image quality and efficiency of the camera in the different filter passbands.

  18. Is postoperative imaging mandatory after meningioma removal? Results of a prospective study.

    Florian Geßler

    Full Text Available Routine postoperative imaging (PI following surgery for intracranial meningiomas is common practice in most neurosurgical departments. The purpose of this study was to determine the role of routine PI and its impact on clinical decision making after resection of meningioma.Patient and tumor characteristics, details of radiographic scans, symptoms and alteration of treatment courses were prospectively collected for patients undergoing removal of a supratentorial meningioma of the convexity, falx, tentorium, or lateral sphenoid wing at the authors' institution between January 1st, 2010 and March 31st, 2012. Patients with infratentorial manifestations or meningiomas of the skull base known to be surgically difficult (e.g. olfactory groove, petroclival, medial sphenoid wing were not included. Maximum tumor diameter was divided into groups of 6 cm (large.206 patients with meningiomas were operated between January 2010 and March 2012. Of these, 113 patients met the inclusion criteria and were analyzed in this study. 83 patients (73.5% did not present new neurological deficits, whereas 30 patients (26.5% became clinically symptomatic. Symptomatic patients had a change in treatment after PI in 21 cases (70%, while PI was without consequence in 9 patients (30%. PI did not result in a change of treatment in all asymptomatic patients (p<0.001 irrespective of tumor size (p<0.001 or localization (p<0.001.PI is mandatory for clinically symptomatic patients but it is safe to waive it in clinically asymptomatic patients, even if the meningioma was large in size.

  19. The study results steganography hiding messages in image files as vehicle security software

    D. O. Navrotskyi


    Full Text Available Synergetics of steganographic and cryptographic encryption algorithms, which provide a solid security foundation, is presented in this paper. Hiding messages systems in spatial and frequency domain image are compared and studied by the author. The following questions: Compression scheme JPEG , JPEG – transformation structure, Practical recommendations for hiding data to image files, The method of least significant bits (spatial domain and the DCT coefficients values relative replacement method (frequency domain, Packing and unpacking the hidden message, Visual distortion image changing system parameters are considered.

  20. Preliminary results of endorectal surface coil magnetic resonance imaging for local staging of prostate cancer

    Jager, G.H. [Radiologische Universitaetsklinik, Nijmegen (Netherlands). Abt. fuer Abdominale Roentgendiagnostik; Barentsz, J.O. [Radiologische Universitaetsklinik, Nijmegen (Netherlands). Abt. fuer Abdominale Roentgendiagnostik; Rosette, J.J.M.C.H. de la [Medizinische Universitaetsklinik, Nijmegen (Netherlands). Abt. fuer Urologie; Rosenbusch, G. [Radiologische Universitaetsklinik, Nijmegen (Netherlands). Abt. fuer Abdominale Roentgendiagnostik


    Objective: To evaluate the effectiveness of endorectal surface coil (ERC) magnetic resonance imaging (MRI) in the local staging of adenocarcinoma of the prostate (ACP). Materials and methods: A total of 23 patients who were considered candidates for radical prostatectomy because of clinically localized ACP were examined by ERC-MRI. All patients underwent laparoscopic or open lymph-node dissection prior to surgery. Four patients had positive lymph nodes at operation. A total of 19 underwant radical prostatectomy, allowing comparison of the MRI data with the surgical pathologic findings. Results: Twelve patients had extraglandular spread of ACP (T3) and 7 had locally confined ACP (T2). ERC-MRI predicted correctly a T3 tumor in 10 of 12 cases and a T2 tumor in 4 of 7 cases. ERC-MRI was 74% accurate in differentiating T2 from T3 tumor. Three cases of overestimation were in studies with poor image quality because of bowel movement motion artifacts. Conclusion: ERC-MRI was found to be a sensitive modality in staging clinically localized ACP. (orig.) [Deutsch] Ziel: Bestimmung der Wertigkeit der Kernspintomographie (MRI) mit einer endorektalen Oberflaechenspule (ERC) fuer das lokale staging des Adenokarzinoms der Prostata (ACP). Material und Methode: Insgesamt 23 Patienten die als Kandidaten fuer eine radikale Prostatektomie wegen eines klinisch lokalisierten ACP galten, wurden mit ERC-MRI untersucht. Alle Patienten unterzogen sich einer laparoskopischen oder offenen Lymphdruesendissektion bei der Operation. Bei 19 Patienten, bei denen eine radikale Prostatektomie ausgefuehrt wurde, konnte eine Korrelation der MRI-Befunde mit denen der Operation erfolgen. Ergebnisse: Zwoelf Patienten wiesen extraglandulaere Ausbreitung des ACP (T3) auf und 7 hatten ein lokal begrenztes ACP (T2). ERC-MRI ergab korrekt einen T3-Tumor in 10 der 12 Faelle und einen T2-Tumor in 4 der 7 Faelle. Die Genauigkeit der ERC-MRI um einen T2- von einem T3-Tumor zu differenzieren betrug 74%. Bei drei

  1. Recent Opportunity Microscopic Imager Results from the Western Rim of Endeavour Crater

    Herkenhoff, K. E.; Arvidson, R. E.; Jolliff, B. L.; Mittlefehldt, D. W.; Sullivan, R. J., Jr.; Gellert, R.; Sims, M. H.


    The Athena science payload on the Mars Exploration Rover Oppor­tunity includes the Microscopic Imager (MI), a fixed-focus close-up camera mounted on the instrument arm. The MI acquires images at a scale of 31 µm/pixel over a broad spectral range (400 to 700 nm) using only natural illumination of target surfaces. Opportunity has been exploring exposures of Noachian-age rocks along the rim of Endeavour crater since August 2011, moti­vated by orbital spectral evidence for phyllosilicates at multiple locations along the crater's rim. Because Opportunity can no longer directly sense phyllosilicate mineralogy with the MiniTES or Mössbauer spectrometers, the rover mis­sion is focusing on characterizing outcrop multispectral reflectance with Pancam, elemental chemistry with the Alpha Particle X-ray Spectrometer (APXS) and microtexture with the MI of potential phyllosilicate host rocks. In addition, the Rock Abrasion Tool (RAT) gives an indication of rock hardness. After traversing more than 42 km (26 miles) since landing in 2004, the rover entered "Marathon Valley" to investigate rock exposures in which phyllosili­cates were detected by the CRISM instrument on the Mars Reconnaissance Orbiter. Where clastic textures are resolved, the outcrop pavement in Marathon Valley consists of poorly-sorted dark, sub-rounded to sub-angular clasts in a soft (based on RAT grind data), fine-grained, brighter matrix (see Figure showing 5x5 cm post-grind MI mosaic of "Pierre Pinaut3," acquired on Sol 4373 when target was fully shadowed). These observations are consistent with high-energy emplacement due to impact cratering. The soft, recessive, altered appearance of the matrix material suggests that it is the likely host of phyllosilicate alteration in these rocks. The bedrock appears to have been aqueously altered, but APXS measurements of major elements indicate that the alteration was isochemical, unlike in other Endeavour rim rocks. Also, MI views of a small patch of dark sand

  2. Clinical results of percutaneous repair of ruptured Achilles tendon with MR imaging

    Nagao, Noritaka; Hamanishi, Hirotsugu (Fujiwara Hospital, Kyoto (Japan))


    Magnetic resonance (MR) imaging was performed to evaluate the usefulness of percutaneous repair according to the modified method of Bunnell for Achilles tendon rupture. The subjects were four men and 4 women, whose ages ranged from 22 to 62 years with a mean of 38.6. No surgical complications, including recurrent rupture, neurological damage and infections, were encountered. Three months after surgery, dorsiflexion of foot was recovered to the degree of the healthy foot. Jogging became possible 5 or 6 months later. The healthy Achilles tendon was seen as low signal intensity, and the ruptured site was seen as high signal intensity on T2-weighted images. Postoperative MR images showed tightness of the Achilles tendon. Signals in the repair site were shifted from isointensity to hypointensity with recovery. The tendon, mainly surrounding the reptured site, was thickened. In conclusion, MR imaging was useful in confirming the ruptured site and evaluating the condition of repair. (N.K.).

  3. Willis PM 10-2.5 Precision Results, pdf has summary table and SEM images

    U.S. Environmental Protection Agency — Precision data from the SEM and SEM images from the samples. This dataset is associated with the following publication: Peters, T., E. Sawvel, R. Willis, R. West,...

  4. Robotic image-guided reirradiation of lateral pelvic recurrences: preliminary results

    Castelain Bernard


    Full Text Available Abstract Background The first-line treatment of a pelvic recurrence in a previously irradiated area is surgery. Unfortunately, few patients are deemed operable, often due to the location of the recurrence, usually too close to the iliac vessels, or the associated surgical morbidity. The objective of this study is to test the viability of robotic image-guided radiotherapy as an alternative treatment in inoperable cases. Methods Sixteen patients previously treated with radiotherapy were reirradiated with CyberKnife® for lateral pelvic lesions. Recurrences of primary rectal cancer (4 patients, anal canal (6, uterine cervix cancer (4, endometrial cancer (1, and bladder carcinoma (1 were treated. The median dose of the previous treatment was 45 Gy (EqD2 range: 20 to 96 Gy. A total dose of 36 Gy in six fractions was delivered with the CyberKnife over three weeks. The responses were evaluated according to RECIST criteria. Results Median follow-up was 10.6 months (1.9 to 20.5 months. The actuarial local control rate was 51.4% at one year. Median disease-free survival was 8.3 months after CyberKnife treatment. The actuarial one-year survival rate was 46%. Acute tolerance was limited to digestive grade 1 and 2 toxicities. Conclusions Robotic stereotactic radiotherapy can offer a short and well-tolerated treatment for lateral pelvic recurrences in previously irradiated areas in patients otherwise not treatable. Efficacy and toxicity need to be evaluated over the long term, but initial results are encouraging.

  5. First Infrared Imaging of the Neptune Ring Arcs: HST/Nicmos Results

    Terrile, R. J.; Dumas, C.; Smith, B. A.; Rieke, M.; Schneider, G.; Thompson, R.; Becklin, E.; Koerner, D.


    Neptune's ring arcs have not been imaged since the Voyager 2 flyby in 1989 (Smith et al. 1989, Science 246, 1422-1449). We used the HST and its near-infrared camera NICMOS to obtain the first detection at infrared wavelengths of the Neptune system of ring arcs. The faint inner satellites Proteus and Larissa were also detected. Scattered light coming from the giant planet was reduced considerably during the observations by positioning Neptune partially outside of the field of view of the camera. In addition to this, we used a filter whose bandpass is centered at 1.87mu m. This wavelength corresponds to a strong absorption by methane in Neptune's atmosphere. Two different values for the mean motion of the ring arcs (Nicholson et al. 1995, Icarus 113, 295-330) fit the ground-based and Voyager data sets. Initial results from this partially competed program indicate that the smaller value of 820.1118 deg/day for the arc motion is a better match to the data than the previously adopted value of 820.1194 deg/day. If this result is confirmed, it will call into question the close match between the semi-major axis of the arcs and the location of the 42:43 corotation resonance with Galatea (Porco 1991, Science 253, 995-1001). From the measurements made at visible wavelengths with Voyager (Thomas and Veverka 1991, JGR Supp. 96, 19253-19259) and at 1.87mu m with HST/Nicmos -- and assuming negligeable changes in the ring arcs color since 1989 -- we will be able to determine the visible/infrared color-index for the arcs and the two faint satellites detected and compare it to other primitive bodies of the outer solar system.

  6. Image quality and dose in mammography in 17 countries in Africa, Asia and Eastern Europe: Results from IAEA projects

    Ciraj-Bjelac, Olivera, E-mail: [Vinca Institute of Nuclear Sciences, Belgrade (Serbia); Avramova-Cholakova, Simona, E-mail: [National Centre of Radiobiology and Radiation Protection (NCRRP), Ministry of Health, Sofia (Bulgaria); Beganovic, Adnan, E-mail: [University of Sarajevo, Institute of Radiology, Sarajevo, Bosnia and Herzegovina (Bosnia and Herzegovina); Economides, Sotirios, E-mail: [Ministry of Development, Greek Atomic Energy Commission, Athens (Greece); Faj, Dario, E-mail: [University Hospital Osijek, Osijek (Croatia); Gershan, Vesna, E-mail: [National Commission on Radiation Protection, Institute of Radiology, Skopje, The Former Yugoslav Republic of Macedonia (Macedonia, The Former Yugoslav Republic of); Grupetta, Edward, E-mail: [St. Luke' s Hospital, Diagnostic Radiology Unit, Guardamangia (Malta); Kharita, M.H., E-mail: [Atomic Energy Commission of Syria (AECS), Department of Protection and Safety, Radiation and Nuclear Regulatory Office, Damascus (Syrian Arab Republic); Milakovic, Milomir, E-mail: [Ministry of Health of the Republic of Srpska, Public Health Institute of Republic of Srpska, Banja Luka, Bosnia and Herzegovina (Bosnia and Herzegovina); Milu, Constantin, E-mail: [Institute of Public Health, SSDL, Bucharest (Romania); Muhogora, Wilbroad E., E-mail: [Tanzania Atomic Energy Commission, Arusha, Tanzania (Tanzania, United Republic of); Muthuvelu, Pirunthavany, E-mail: [Ministry of Health, Radiation Health Safety Branch, Putra Jaya (Malaysia); Oola, Samuel, E-mail: [Mulago Hospital, Department of Radiology, Kampala (Uganda); Setayeshi, Saeid, E-mail: [Ministry of Health, Treatment, and Medical Training, Tehran (Iran, Islamic Republic of); and others


    Purpose: The objective is to study mammography practice from an optimisation point of view by assessing the impact of simple and immediately implementable corrective actions on image quality. Materials and methods: This prospective multinational study included 54 mammography units in 17 countries. More than 21,000 mammography images were evaluated using a three-level image quality scoring system. Following initial assessment, appropriate corrective actions were implemented and image quality was re-assessed in 24 units. Results: The fraction of images that were considered acceptable without any remark in the first phase (before the implementation of corrective actions) was 70% and 75% for cranio-caudal and medio-lateral oblique projections, respectively. The main causes for poor image quality before corrective actions were related to film processing, damaged or scratched image receptors, or film-screen combinations that are not spectrally matched, inappropriate radiographic techniques and lack of training. Average glandular dose to a standard breast was 1.5 mGy (mean and range 0.59–3.2 mGy). After optimisation the frequency of poor quality images decreased, but the relative contributions of the various causes remained similar. Image quality improvements following appropriate corrective actions were up to 50 percentage points in some facilities. Conclusions: Poor image quality is a major source of unnecessary radiation dose to the breast. An increased awareness of good quality mammograms is of particular importance for countries that are moving towards introduction of population-based screening programmes. The study demonstrated how simple and low-cost measures can be a valuable tool in improving of image quality in mammography.

  7. Integration of intraoperative and model-updated images into an industry-standard neuronavigation system: initial results

    Schaewe, Timothy J.; Fan, Xiaoyao; Ji, Songbai; Hartov, Alex; Hiemenz Holton, Leslie; Roberts, David W.; Paulsen, Keith D.; Simon, David A.


    Dartmouth and Medtronic have established an academic-industrial partnership to develop, validate, and evaluate a multimodality neurosurgical image-guidance platform for brain tumor resection surgery that is capable of updating the spatial relationships between preoperative images and the current surgical field. Previous studies have shown that brain shift compensation through a modeling framework using intraoperative ultrasound and/or visible light stereovision to update preoperative MRI appears to result in improved accuracy in navigation. However, image updates have thus far only been produced retrospective to surgery in large part because of gaps in the software integration and information flow between the co-registration and tracking, image acquisition and processing, and image warping tasks which are required during a case. This paper reports the first demonstration of integration of a deformation-based image updating process for brain shift modeling with an industry-standard image guided surgery platform. Specifically, we have completed the first and most critical data transfer operation to transmit volumetric image data generated by the Dartmouth brain shift modeling process to the Medtronic StealthStation® system. StealthStation® comparison views, which allow the surgeon to verify the correspondence of the received updated image volume relative to the preoperative MRI, are presented, along with other displays of image data such as the intraoperative 3D ultrasound used to update the model. These views and data represent the first time that externally acquired and manipulated image data has been imported into the StealthStation® system through the StealthLink® portal and visualized on the StealthStation® display.

  8. Principle and experimental results of ultra-wideband noise radar imaging of a cylindrical conducting object using diffraction tomography

    Shin, Hee Jung; Asmuth, Mark A.; Narayanan, Ram M.; Rangaswamy, Muralidhar


    In this paper, the principle, simulation, and experiment results of tomographic imaging of a cylindrical conducting object using random noise waveforms are presented. Theoretical analysis of scattering and the image reconstruction technique are developed based on physical optics approximation and Fourier diffraction tomography, respectively. The bistatic radar system is designed to transmit band-limited ultra-wideband (UWB) random noise waveforms at a fixed position, and a linear scanner allows a single receiving antenna to move along a horizontal axis for backward scattering measurement in the frequency range from 3-5 GHz. The reconstructed tomographic image of the rotating cylindrical conducting object based on experimental results are seen to be in good agreement with the simulation results, which demonstrates the capability of UWB noise radar for complete two-dimensional tomographic image reconstruction of a cylindrical conducting object.

  9. Interest of correlation-based automatic target recognition in underwater optical images: theoretical justification and first results

    Leonard, I.; Arnold-Bos, A.; Alfalou, A.


    In this paper, we explore the use of optical correlation-based recognition to identify and position underwater man-made objects (e.g. mines). Correlation techniques can be defined as a simple comparison between an observed image (image to recognize) and a reference image; they can be achieved extremely fast. The result of this comparison is a more or less intense correlation peak, depending on the resemblance degree between the observed image and a reference image coming from a database. However, to perform a good correlation decision, we should compare our observed image with a huge database of references, covering all the appearances of objects we search. Introducing all the appearances of objects can influence speed and/or recognition quality. To overcome this limitation, we propose to use composite filter techniques, which allow the fusion of several references and drastically reduce the number of needed comparisons to identify observed images. These recent techniques have not yet been exploited in the underwater context. In addition, they allow for integrating some preprocessing directly in the correlation filter manufacturing step to enhance the visibility of objects. Applying all the preprocessing in one step reduces the processing by avoiding unnecessary Fourier transforms and their inverse operation. We want to obtain filters that are independent from all noises and contrast problems found in underwater videos. To achieve this and to create a database containing all scales and viewpoints, we use as references 3D computer-generated images.

  10. The preliminary results: Internal seismic velocity structure imaging beneath Mount Lokon

    Firmansyah, Rizky; Nugraha, Andri Dian; Kristianto


    Historical records that before the 17th century, Mount Lokon had been dormant for approximately 400 years. In the years between 1350 and 1400, eruption ever recorded in Empung, came from Mount Lokon's central crater. Subsequently, in 1750 to 1800, Mount Lokon continued to erupt again and caused soil damage and fall victim. After 1949, Mount Lokon dramatically increased in its frequency: the eruption interval varies between 1 - 5 years, with an average interval of 3 years and a rest interval ranged from 8 - 64 years. Then, on June 26th, 2011, standby alert set by the Center for Volcanology and Geological Hazard Mitigation. Peak activity happened on July 4th, 2011 that Mount Lokon erupted continuously until August 28th, 2011. In this study, we carefully analyzed micro-earthquakes waveform and determined hypocenter location of those events. We then conducted travel time seismic tomographic inversion using SIMULPS12 method to detemine Vp, Vs and Vp/Vs ratio structures beneath Lokon volcano in order to enhance our subsurface geological structure. During the tomographic inversion, we started from 1-D seismic velocities model obtained from VELEST33 method. Our preliminary results show low Vp, low Vs, and high Vp/Vs are observed beneath Mount Lokon-Empung which are may be associated with weak zone or hot material zones. However, in this study we used few station for recording of micro-earthquake events. So, we suggest in the future tomography study, the adding of some seismometers in order to improve ray coverage in the region is profoundly justified.

  11. The preliminary results: Internal seismic velocity structure imaging beneath Mount Lokon

    Firmansyah, Rizky, E-mail: [Geophysical Engineering, Faculty of Mining and Petroleum Engineering, Institut Teknologi Bandung, Bandung, 40132 (Indonesia); Nugraha, Andri Dian, E-mail: [Global Geophysical Group, Faculty of Mining and Petroleum Engineering, Institut Teknologi Bandung, Bandung, 40132 (Indonesia); Kristianto, E-mail: [Center for Volcanology and Geological Hazard Mitigation (CVGHM), Geological Agency, Bandung, 40122 (Indonesia)


    Historical records that before the 17{sup th} century, Mount Lokon had been dormant for approximately 400 years. In the years between 1350 and 1400, eruption ever recorded in Empung, came from Mount Lokon’s central crater. Subsequently, in 1750 to 1800, Mount Lokon continued to erupt again and caused soil damage and fall victim. After 1949, Mount Lokon dramatically increased in its frequency: the eruption interval varies between 1 – 5 years, with an average interval of 3 years and a rest interval ranged from 8 – 64 years. Then, on June 26{sup th}, 2011, standby alert set by the Center for Volcanology and Geological Hazard Mitigation. Peak activity happened on July 4{sup th}, 2011 that Mount Lokon erupted continuously until August 28{sup th}, 2011. In this study, we carefully analyzed micro-earthquakes waveform and determined hypocenter location of those events. We then conducted travel time seismic tomographic inversion using SIMULPS12 method to detemine Vp, Vs and Vp/Vs ratio structures beneath Lokon volcano in order to enhance our subsurface geological structure. During the tomographic inversion, we started from 1-D seismic velocities model obtained from VELEST33 method. Our preliminary results show low Vp, low Vs, and high Vp/Vs are observed beneath Mount Lokon-Empung which are may be associated with weak zone or hot material zones. However, in this study we used few station for recording of micro-earthquake events. So, we suggest in the future tomography study, the adding of some seismometers in order to improve ray coverage in the region is profoundly justified.

  12. TSPO PET for glioma imaging using the novel ligand (18)F-GE-180: first results in patients with glioblastoma.

    Albert, Nathalie L; Unterrainer, M; Fleischmann, D F; Lindner, S; Vettermann, F; Brunegraf, A; Vomacka, L; Brendel, M; Wenter, V; Wetzel, C; Rupprecht, R; Tonn, J-C; Belka, C; Bartenstein, P; Niyazi, M


    The 18-kDa mitochondrial translocator protein (TSPO) was reported to be upregulated in gliomas. (18)F-GE-180 is a novel 3rd generation TSPO receptor ligand with improved target-to-background contrast compared to previous tracers. In this pilot study, we compared PET imaging with (18)F-GE-180 and MRI of patients with untreated and recurrent pretreated glioblastoma. Eleven patients with histologically confirmed IDH wildtype gliomas (10 glioblastomas, 1 anaplastic astrocytoma) underwent (18)F-GE-180 PET at initial diagnosis or recurrence. The PET parameters mean background uptake (SUVBG), maximal tumour-to-background ratio (TBRmax) and PET volume using different thresholds (SUVBG × 1.6, 1.8 and 2.0) were evaluated in the 60-80 min p.i. summation images. The different PET volumes were compared to the contrast-enhancing tumour volume on MRI. All gliomas were positive on (18)F-GE-180 PET and were depicted with extraordinarily high tumour-to-background contrast (median SUVBG 0.47 (0.37-0.93), TBRmax 6.61 (3.88-9.07)). (18)F-GE-180 uptake could be found even in areas without contrast enhancement on MRI, leading to significantly larger PET volumes than MRI-based volumes (median 90.5, 74.5, and 63.8 mL vs. 31.0 mL; p = 0.003, 0.004, 0.013). In percentage difference, the PET volumes were on average 179%, 135%, and 90% larger than the respective MRI volumes. The median spatial volumetric correlation (Sørensen-Dice coefficient) of PET volumes and MRI volumes prior to radiotherapy was 0.48, 0.54, and 0.58. (18)F-GE-180 PET provides a remarkably high tumour-to-background contrast in untreated and pretreated glioblastoma and shows tracer uptake even beyond contrast enhancement on MRI. To what extent (18)F-GE-180 uptake reflects the tumour extent of human gliomas and inflammatory cells remains to be evaluated in future prospective studies with guided stereotactic biopsies and correlation of histopathological results.

  13. High contrast imaging in multi-star systems: technology development and first lab results

    Belikov, Ruslan; Bendek, Eduardo; Pluzhnik, Eugene; Sirbu, Dan; Thomas, Sandrine J.


    We show preliminary laboratory results advancing the technology readiness of a method to directly image planets and disks in multi-star systems such as Alpha Centauri. This method works with almost any coronagraph (or external occulter with a DM) and requires little or no change to existing and mature hardware. Because of the ubiquity of multistar systems, this method potentially multiplies the science yield of many missions and concepts such as WFIRST, Exo-C/S, HabEx, LUVOIR, and potentially enables the detection of Earth-like planets (if they exist) around our nearest neighbor star, Alpha Centauri, with a small and low-cost space telescope such as ACESat. We identified two main challenges associated with double-star (or multi-star) systems and methods to solve them. "Multi-Star Wavefront Control" (MSWC) enables the independent suppression of starlight from more than one star, and Super-Nyquist Wavefront Control (SNWC) enables extending MSWC to the case where star separation is beyond the Nyquist limit of the deformable mirror (DM). Our lab demonstrations were conducted at the Ames Coronagraph Experiment (ACE) laboratory and proved the basic principles of both MSWC and SNWC. They involved a 32x32 deformable mirror but no coronagraph for simplicity. We used MSWC to suppress starlight independently from two stars by at least an order of magnitude, in monochromatic as well as broadband light as broad as 50%. We also used SNWC to suppress starlight at 32 l/D, surpassing the Nyquist limit of the DM.

  14. Cardiac remodeling following percutaneous mitral valve repair. Initial results assessed by cardiovascular magnetic resonance imaging

    Radunski, U.K [University Heart Center, Hamburg (Germany). Cardiology; Franzen, O. [Rigshospitalet, Copenhagen (Denmark). Cardiology; Barmeyer, A. [Klinikum Dortmund (Germany). Kardiologie; and others


    Percutaneous mitral valve repair with the MitraClip device (Abbott Vascular, Redwood City, California, USA) is a novel therapeutic option in patients with mitral regurgitation. This study evaluated the feasibility of cardiac volume measurements by cardiovascular magnetic resonance imaging (CMR) to assess reverse myocardial remodeling in patients after MitraClip implantation. 12 patients underwent CMR at baseline (BL) before and at 6 months follow-up (FU) after MitraClip implantation. Cine-CMR was performed in short- and long-axes for the assessment of left ventricular (LV), right ventricular (RV) and left atrial (LA) volumes. Assessment of endocardial contours was not compromised by the device-related artifact. No significant differences in observer variances were observed for LV, RV and LA volume measurements between BL and FU. LV end-diastolic (median 127 [IQR 96-150] vs. 112 [86-150] ml/m{sup 2}; p=0.03) and LV end-systolic (82 [54-91] vs. 69 [48-99] ml/m{sup 2}; p=0.03) volume indices decreased significantly from BL to FU. No significant differences were found for RV end-diastolic (94 [75-103] vs. 99 [77-123] ml/m{sup 2}; p=0.91), RV end-systolic (48 [42-80] vs. 51 [40-81] ml/m{sup 2}; p=0.48), and LA (87 [55-124] vs. 92 [48-137]R ml/m{sup 2}; p=0.20) volume indices between BL and FU. CMR enables the assessment of cardiac volumes in patients after MitraClip implantation. Our CMR findings indicate that percutaneous mitral valve repair results in reverse LV but not in RV or LA remodeling.

  15. Imaging Arterial Fibres Using Diffusion Tensor Imaging—Feasibility Study and Preliminary Results

    Kerskens Christian


    Full Text Available Abstract MR diffusion tensor imaging (DTI was used to analyze the fibrous structure of aortic tissue. A fresh porcine aorta was imaged at 7T using a spin echo sequence with the following parameters: matrix 128 128 pixel; slice thickness 0.5 mm; interslice spacing 0.1 mm; number of slices 16; echo time 20.3 s; field of view 28 mm 28 mm. Eigenvectors from the diffusion tensor images were calculated for the central image slice and the averaged tensors and the eigenvector corresponding to the largest eigenvalue showed two distinct angles corresponding to near and to the transverse plane of the aorta. Fibre tractography within the aortic volume imaged confirmed that fibre angles were oriented helically with lead angles of and . The findings correspond to current histological and microscopy data on the fibrous structure of aortic tissue, and therefore the eigenvector maps and fibre tractography appear to reflect the alignment of the fibers in the aorta. In view of current efforts to develop noninvasive diagnostic tools for cardiovascular diseases, DTI may offer a technique to assess the structural properties of arterial tissue and hence any changes or degradation in arterial tissue.

  16. Imaging Arterial Fibres Using Diffusion Tensor Imaging—Feasibility Study and Preliminary Results

    Ciaran K. Simms


    Full Text Available MR diffusion tensor imaging (DTI was used to analyze the fibrous structure of aortic tissue. A fresh porcine aorta was imaged at 7T using a spin echo sequence with the following parameters: matrix 128 × 128 pixel; slice thickness 0.5 mm; interslice spacing 0.1 mm; number of slices 16; echo time 20.3 s; field of view 28 mm × 28 mm. Eigenvectors from the diffusion tensor images were calculated for the central image slice and the averaged tensors and the eigenvector corresponding to the largest eigenvalue showed two distinct angles corresponding to near 0∘ and 180∘ to the transverse plane of the aorta. Fibre tractography within the aortic volume imaged confirmed that fibre angles were oriented helically with lead angles of 15±2.5∘ and 175±2.5∘. The findings correspond to current histological and microscopy data on the fibrous structure of aortic tissue, and therefore the eigenvector maps and fibre tractography appear to reflect the alignment of the fibers in the aorta. In view of current efforts to develop noninvasive diagnostic tools for cardiovascular diseases, DTI may offer a technique to assess the structural properties of arterial tissue and hence any changes or degradation in arterial tissue.

  17. Fractal Analysis of Elastographic Images for Automatic Detection of Diffuse Diseases of Salivary Glands: Preliminary Results

    Alexandru Florin Badea


    Full Text Available The geometry of some medical images of tissues, obtained by elastography and ultrasonography, is characterized in terms of complexity parameters such as the fractal dimension (FD. It is well known that in any image there are very subtle details that are not easily detectable by the human eye. However, in many cases like medical imaging diagnosis, these details are very important since they might contain some hidden information about the possible existence of certain pathological lesions like tissue degeneration, inflammation, or tumors. Therefore, an automatic method of analysis could be an expedient tool for physicians to give a faultless diagnosis. The fractal analysis is of great importance in relation to a quantitative evaluation of “real-time” elastography, a procedure considered to be operator dependent in the current clinical practice. Mathematical analysis reveals significant discrepancies among normal and pathological image patterns. The main objective of our work is to demonstrate the clinical utility of this procedure on an ultrasound image corresponding to a submandibular diffuse pathology.

  18. Images

    National Aeronautics and Space Administration — Images for the website main pages and all configurations. The upload and access points for the other images are: Website Template RSW images BSCW Images HIRENASD...

  19. Measuring Three-Dimensional Thorax Motion Via Biplane Radiographic Imaging: Technique and Preliminary Results.

    Baumer, Timothy G; Giles, Joshua W; Drake, Anne; Zauel, Roger; Bey, Michael J


    Measures of scapulothoracic motion are dependent on accurate imaging of the scapula and thorax. Advanced radiographic techniques can provide accurate measures of scapular motion, but the limited 3D imaging volume of these techniques often precludes measurement of thorax motion. To overcome this, a thorax coordinate system was defined based on the position of rib pairs and then compared to a conventional sternum/spine-based thorax coordinate system. Alignment of the rib-based coordinate system was dependent on the rib pairs used, with the rib3:rib4 pairing aligned to within 4.4 ± 2.1 deg of the conventional thorax coordinate system.

  20. Preliminary Results on VLT K-band Imaging Observations of GRB Host Galaxies

    E. Le Floc’h; I. F. Mirabel; P.-A. Duc


    We have obtained -band imaging observations of Gamma-Ray Burst (GRB) host galaxies with the near-infrared spectro-imager ISAAC installed on the Very Large Telescope at Paranal (Chile). The derived magnitudes, combined with other photometric data taken from the literature, are used to investigate the – colors of GRB hosts. We do not find any extremely reddened starbursts in our sample, despite the capability of GRBs to trace star formation even in dusty regions. The observed – colors are on the contrary typical of irregular and spiral blue galaxies at high redshift.

  1. Metals in the z~3 intergalactic medium: results from an ultra-high signal-to-noise ratio UVES quasar spectrum

    D'Odorico, V; Pomante, E; Carswell, R F; Viel, M; Barai, P; Becker, G D; Calura, F; Cupani, G; Fontanot, F; Haehnelt, M G; Kim, T-S; Miralda-Escude, J; Rorai, A; Tescari, E; Vanzella, E


    In this work, we investigate the abundance and distribution of metals in the intergalactic medium (IGM) at $\\langle z \\rangle \\simeq 2.8$ through the analysis of an ultra-high signal-to-noise ratio UVES spectrum of the quasar HE0940-1050. In the CIV forest, our deep spectrum is sensitive at $3\\,\\sigma$ to lines with column density down to $\\log N_{\\rm CIV} \\simeq 11.4$ and in 60 percent of the considered redshift range down to $\\simeq11.1$. In our sample, all HI lines with $\\log N_{\\rm HI} \\ge 14.8$ show an associated CIV absorption. In the range $14.0 \\le \\log N_{\\rm HI} <14.8$, 43 percent of HI lines has an associated CIV absorption. At $\\log N_{\\rm HI} < 14.0$, the detection rates drop to $<10$ percent, possibly due to our sensitivity limits and not to an actual variation of the gas abundance properties. In the range $\\log N_{\\rm HI} \\ge 14$, we observe a fraction of HI lines with detected CIV a factor of 2 larger than the fraction of HI lines lying in the circum-galactic medium (CGM) of relativel...

  2. Experimental Results of Ground Disturbance Detection Using Uncooled Infrared Imagers in Wideband and Multispectral Modes


    digitally at 14-bit resolution via a user interface by a computer. An adaptor was made and mounted to the front of the imager aperture for LWIR filter...1996). Mesure de signatures infrarouges de mines terrestres et expériences de perception. DREV-R- 9525. Defence R&D Canada. 43 pages. [2] Simard

  3. Diffusion tensor imaging and tractography of the median nerve in carpal tunnel syndrome: preliminary results

    Khalil, C.; Hancart, C.; Thuc, V.Le; Cotten, A. [Service de Radiologie Osteoarticulaire, Hopital Roger Salengro, CHRU de Lille (France); Chantelot, C. [Clinique d' Orthopedie, Hopital Roger Salengro, CHRU de Lille (France); Chechin, D. [Philips Medical Systems, Suresnes (France)


    The purpose was to demonstrate the feasibility of in vivo diffusion tensor imaging (DTI) and tractography of the human median nerve with a 1.5-T MR scanner and to assess potential differences in diffusion between healthy volunteers and patients suffering from carpal tunnel syndrome. The median nerve was examined in 13 patients and 13 healthy volunteers with MR DTI and tractography using a 1.5-T MRI scanner with a dedicated wrist coil. T1-weighted images were performed for anatomical correlation. Mean fractional anisotropy (FA) and mean apparent diffusion coefficient (ADC) values were quantified in the median nerve on tractography images. In all subjects, the nerve orientation and course could be detected with tractography. Mean FA values were significantly lower in patients (p=0.03). However, no statistically significant differences were found for mean ADC values. In vivo assessment of the median nerve in the carpal tunnel using DTI with tractography on a 1.5-T MRI scanner is possible. Microstructural parameters can be easily obtained from tractography images. A significant decrease of mean FA values was found in patients suffering from chronic compression of the median nerve. Further investigations are necessary to determine if mean FA values may be correlated with the severity of nerve entrapment. (orig.)

  4. Results from field tests of the one-dimensional Time-Encoded Imaging System.

    Marleau, Peter; Brennan, James S.; Brubaker, Erik


    A series of field experiments were undertaken to evaluate the performance of the one dimensional time encoded imaging system. The significant detection of a Cf252 fission radiation source was demonstrated at a stand-off of 100 meters. Extrapolations to different quantities of plutonium equivalent at different distances are made. Hardware modifications to the system for follow on work are suggested.

  5. Cross-Language Transfer of Indexing Concepts for Storage and Retrieval of Moving Images: Preliminary Results.

    Turner, James M.


    A French-language version of stock footage videotapes from previous research (using English-language data) was prepared, using the same images. The most popular terms identified in each of the two studies for each of the shots are compared, to determine the rate of correspondence between potential indexing terms in each language. (Author/AEF)

  6. Results of Automated Retinal Image Analysis for Detection of Diabetic Retinopathy from the Nakuru Study, Kenya

    Juul Bøgelund Hansen, Morten; Abramoff, M. D.; Folk, J. C.


    Objective Digital retinal imaging is an established method of screening for diabetic retinopathy (DR). It has been established that currently about 1% of the world's blind or visually impaired is due to DR. However, the increasing prevalence of diabetes mellitus and DR is creating an increased wo...

  7. Quantitative Amyloid Imaging in Autosomal Dominant Alzheimer's Disease: Results from the DIAN Study Group.

    Yi Su

    Full Text Available Amyloid imaging plays an important role in the research and diagnosis of dementing disorders. Substantial variation in quantitative methods to measure brain amyloid burden exists in the field. The aim of this work is to investigate the impact of methodological variations to the quantification of amyloid burden using data from the Dominantly Inherited Alzheimer's Network (DIAN, an autosomal dominant Alzheimer's disease population. Cross-sectional and longitudinal [11C]-Pittsburgh Compound B (PiB PET imaging data from the DIAN study were analyzed. Four candidate reference regions were investigated for estimation of brain amyloid burden. A regional spread function based technique was also investigated for the correction of partial volume effects. Cerebellar cortex, brain-stem, and white matter regions all had stable tracer retention during the course of disease. Partial volume correction consistently improves sensitivity to group differences and longitudinal changes over time. White matter referencing improved statistical power in the detecting longitudinal changes in relative tracer retention; however, the reason for this improvement is unclear and requires further investigation. Full dynamic acquisition and kinetic modeling improved statistical power although it may add cost and time. Several technical variations to amyloid burden quantification were examined in this study. Partial volume correction emerged as the strategy that most consistently improved statistical power for the detection of both longitudinal changes and across-group differences. For the autosomal dominant Alzheimer's disease population with PiB imaging, utilizing brainstem as a reference region with partial volume correction may be optimal for current interventional trials. Further investigation of technical issues in quantitative amyloid imaging in different study populations using different amyloid imaging tracers is warranted.

  8. Quantitative Amyloid Imaging in Autosomal Dominant Alzheimer’s Disease: Results from the DIAN Study Group

    Su, Yi; Blazey, Tyler M.; Owen, Christopher J.; Christensen, Jon J.; Friedrichsen, Karl; Joseph-Mathurin, Nelly; Wang, Qing; Hornbeck, Russ C.; Ances, Beau M.; Snyder, Abraham Z.; Cash, Lisa A.; Koeppe, Robert A.; Klunk, William E.; Galasko, Douglas; Brickman, Adam M.; McDade, Eric; Ringman, John M.; Thompson, Paul M.; Saykin, Andrew J.; Ghetti, Bernardino; Sperling, Reisa A.; Johnson, Keith A.; Salloway, Stephen P.; Schofield, Peter R.; Masters, Colin L.; Villemagne, Victor L.; Fox, Nick C.; Förster, Stefan; Chen, Kewei; Reiman, Eric M.; Xiong, Chengjie; Marcus, Daniel S.; Weiner, Michael W.; Morris, John C.; Bateman, Randall J.; Benzinger, Tammie L. S.


    Amyloid imaging plays an important role in the research and diagnosis of dementing disorders. Substantial variation in quantitative methods to measure brain amyloid burden exists in the field. The aim of this work is to investigate the impact of methodological variations to the quantification of amyloid burden using data from the Dominantly Inherited Alzheimer’s Network (DIAN), an autosomal dominant Alzheimer’s disease population. Cross-sectional and longitudinal [11C]-Pittsburgh Compound B (PiB) PET imaging data from the DIAN study were analyzed. Four candidate reference regions were investigated for estimation of brain amyloid burden. A regional spread function based technique was also investigated for the correction of partial volume effects. Cerebellar cortex, brain-stem, and white matter regions all had stable tracer retention during the course of disease. Partial volume correction consistently improves sensitivity to group differences and longitudinal changes over time. White matter referencing improved statistical power in the detecting longitudinal changes in relative tracer retention; however, the reason for this improvement is unclear and requires further investigation. Full dynamic acquisition and kinetic modeling improved statistical power although it may add cost and time. Several technical variations to amyloid burden quantification were examined in this study. Partial volume correction emerged as the strategy that most consistently improved statistical power for the detection of both longitudinal changes and across-group differences. For the autosomal dominant Alzheimer’s disease population with PiB imaging, utilizing brainstem as a reference region with partial volume correction may be optimal for current interventional trials. Further investigation of technical issues in quantitative amyloid imaging in different study populations using different amyloid imaging tracers is warranted. PMID:27010959

  9. Gemini Planet Imager Exoplanet Survey: Key Results Two Years Into The Survey

    Marchis, Franck; Rameau, Julien; Nielsen, Eric L.; De Rosa, Robert J.; Esposito, Thomas; Draper, Zachary H.; Macintosh, Bruce; Graham, James R.; GPIES


    The Gemini Planet Imager Exoplanet Survey (GPIES) is targeting 600 young, nearby stars using the GPI instrument. We report here on recent results obtained with this instrument from our team.Rameau et al. (ApJL, 822 2, L2, 2016) presented astrometric monitoring of the young exoplanet HD 95086 b obtained with GPI between 2013 and 2016. Efficient Monte Carlo techniques place preliminary constraints on the orbital parameters of HD 95086 b. Under the assumption of a coplanar planet-disk system, the periastron of HD 95086 b is beyond 51 AU. Therefore, HD 95086 b cannot carve the entire gap inferred from the measured infrared excess in the SED of HD 95086. Additional photometric and spectroscopic measurements reported by de Rosa et al. (2016, apJ, in press) showed that the spectral energy distribution of HD 95086 b is best fit by low temperature (T~800-1300 K), low surface gravity spectra from models which simulate high photospheric dust content. Its temperature is typical to L/T transition objects, but the spectral type is poorly constrained. HD 95086 b is an important exoplanet to test our models of atmospheric properties of young extrasolar planets.Direct detections of debris disk are keys to infer the collisional past and understand the formation of planetary systems. Two debris disks were recently studied with GPI:- Draper et al. (submitted to ApJ, 2016) show the resolved circumstellar debris disk around HD 111520 at a projected range of ~30-100 AU using both total and polarized H-band intensity. Structures in the disks such as a large brightness asymmetry and symmetric polarization fraction are seen. Additional data would confirm if a large disruption event from a stellar fly-by or planetary perturbations altered the disk density- Esposito et al. (submitted to ApJ, 2016) combined Keck NIRC2 data taken at 1.2-2.3 microns and GPI 1.6 micron total intensity and polarized light detections that probes down to projected separations less than 10 AU to show that the HD

  10. Improved visual [(123)I]FP-CIT SPECT interpretation for evaluation of parkinsonism by visual rating of parametric distribution volume ratio images.

    Meyer, P T; Winz, O H; Dafotakis, M; Werner, C J; Krohn, T; Schäfer, W M


    Imaging of presynaptic dopamine transporters (DAT) by single-photon emission computed tomography (SPECT) and [(123)I]FP-CIT is an established method for differentiating between neurodegenerative and non-neurodegenerative parkinsonism. Whereas a region-of-interest (ROI) analysis is the method of choice for analyzing [(123)I]FP-CIT SPECT studies, visual image interpretations can also provide highly accurate results. The present study was undertaken to validate a visual reading system for parametric volume of distribution (DVR) [(123)I]FP-CIT SPECT images that combines the quantitative nature of ROI analyses and the simplicity of visual readings. A 9-step linear visual rating template for semi-quantitative DVR ratings of caudate nucleus and putamen was developed (VRDVR). The conventional 4-step visual reading system that is mainly based on the [(123)I]FP-CIT uptake pattern was used for comparison (VRP method). Six independent observers retrospectively rated the [(123)I]FP-CIT scans of 30 consecutive parkinsonism and tremor patients (N.=16 neurodegenerative, N.=14 non-neurodegenerative) using VRDVR and VRP. In addition, a highly trained investigator performed manual ROI analyses. The ROI analysis provided complete separation of both patient groups by comparing the lower DAT binding of both putamina (i.e., putamen contralateral to clinically most affected side in neurodegenerative parkinsonism). Using VRP, the two most experienced observers correctly classified all patients while 20 false-positive ratings occurred in the less experienced observers (mean area under the receiver operating characteristic curve [AUCROC] of all observers 0.93±0.07). The VRDVR ratings of the two most experienced observers did not overlap between patient groups, although at different VRDVR score cut-offs. Using the same VRDVR score cut-off for all observers, only six false-negative and one false-positive ratings occurred in total (AUCROC 0.99±0.01). Inter-observer agreement was good for VRP

  11. The cardiothoracic ratio and all-cause and cardiovascular disease mortality in patients undergoing maintenance hemodialysis: results of the MBD-5D study.

    Ogata, Hiroaki; Kumasawa, Junji; Fukuma, Shingo; Mizobuchi, Masahide; Kinugasa, Eriko; Fukagawa, Masafumi; Fukuhara, Shunichi; Akizawa, Tadao


    The cardiothoracic ratio (CTR) is a non-invasive left ventricular hypertrophy index. However, whether CTR associates with cardiovascular disease (CVD) and mortality in hemodialysis (HD) populations is unclear. Using a Mineral and Bone disorder Outcomes Study for Japanese CKD Stage 5D Patients (MBD-5D Study) subcohort, 2266 prevalent HD patients (age 62.8 years, female 38.0%, HD duration 9.4 years) with secondary hyperparathyroidism (SHPT) whose baseline CTR had been recorded were selected. We evaluated associations between CTR and all-cause death, CVD death, or composite events in HD patients. CTR was associated significantly with various background and laboratory characteristics. All-cause death, CVD-related death, and composite events increased across the CTR quartiles (Q). Adjusted hazard risk (HR) for all-cause death was 1.4 (95% confidential interval, 0.9-2.1) in Q2, 1.9 (1.3-2.9) in Q3, and 2.6 (1.7-4.0) in Q4, respectively (Q1 as a reference). The corresponding adjusted HR for CVD-related death was 1.8 (0.8-4.2), 3.1 (1.4-6.8), and 3.5 (1.6-7.9), and that for composite outcome was 1.2 (1.0-1.6), 1.7 (1.3-2.2), and 1.8 (1.5-2.3), respectively. Exploratory analysis revealed that there were relationships between CTR and age, sex, body mass index, comorbidity of CVD, dialysis duration, dialysate calcium level and intact parathyroid hormone, phosphorus, hemoglobin, and usage of phosphate binder. CTR correlated with all-cause death, CVD death, and composite events in HD patients with SHPT.

  12. Evaluation of the Lactate-to-N-Acetyl-aspartate Ratio Defined With Magnetic Resonance Spectroscopic Imaging Before Radiation Therapy as a New Predictive Marker of the Site of Relapse in Patients With Glioblastoma Multiforme

    Deviers, Alexandra [Département de Radiothérapie, Institut Claudius Regaud, Toulouse (France); UMR (Unité Mixte de Recherche) 825, Institut National de la Santé et de la Recherche Médicale, Toulouse (France); INP (Institut National Polytechnique), ENVT (Ecole Nationale Vétérinaire de Toulouse), Unité d' Anatomie-Imagerie-Embryologie, Université de Toulouse, Toulouse (France); Ken, Soléakhéna [Département de Radiothérapie, Institut Claudius Regaud, Toulouse (France); UMR (Unité Mixte de Recherche) 825, Institut National de la Santé et de la Recherche Médicale, Toulouse (France); Filleron, Thomas [Bureau des Etudes Cliniques, Institut Claudius Regaud, Toulouse (France); Rowland, Benjamin; Laruelo, Andrea [Département de Radiothérapie, Institut Claudius Regaud, Toulouse (France); Catalaa, Isabelle; Lubrano, Vincent [UMR (Unité Mixte de Recherche) 825, Institut National de la Santé et de la Recherche Médicale, Toulouse (France); Hôpital de Rangueil, CHU (Centre Hospitalier Universitaire) de Toulouse, Toulouse (France); Celsis, Pierre [UMR (Unité Mixte de Recherche) 825, Institut National de la Santé et de la Recherche Médicale, Toulouse (France); and others


    Purpose: Because lactate accumulation is considered a surrogate for hypoxia and tumor radiation resistance, we studied the spatial distribution of the lactate-to-N-acetyl-aspartate ratio (LNR) before radiation therapy (RT) with 3D proton magnetic resonance spectroscopic imaging (3D-{sup 1}H-MRSI) and assessed its impact on local tumor control in glioblastoma (GBM). Methods and Materials: Fourteen patients with newly diagnosed GBM included in a phase 2 chemoradiation therapy trial constituted our database. Magnetic resonance imaging (MRI) and MRSI data before RT were evaluated and correlated to MRI data at relapse. The optimal threshold for tumor-associated LNR was determined with receiver-operating-characteristic (ROC) curve analysis of the pre-RT LNR values and MRI characteristics of the tumor. This threshold was used to segment pre-RT normalized LNR maps. Two spatial analyses were performed: (1) a pre-RT volumetric comparison of abnormal LNR areas with regions of MRI-defined lesions and a choline (Cho)-to- N-acetyl-aspartate (NAA) ratio ≥2 (CNR2); and (2) a voxel-by-voxel spatial analysis of 4,186,185 voxels with the intention of evaluating whether pre-RT abnormal LNR areas were predictive of the site of local recurrence. Results: A LNR of ≥0.4 (LNR-0.4) discriminated between tumor-associated and normal LNR values with 88.8% sensitivity and 97.6% specificity. LNR-0.4 voxels were spatially different from those of MRI-defined lesions, representing 44% of contrast enhancement, 64% of central necrosis, and 26% of fluid-attenuated inversion recovery (FLAIR) abnormality volumes before RT. They extended beyond the overlap with CNR2 for most patients (median: 20 cm{sup 3}; range: 6-49 cm{sup 3}). LNR-0.4 voxels were significantly predictive of local recurrence, regarded as contrast enhancement at relapse: 71% of voxels with a LNR-0.4 before RT were contrast enhanced at relapse versus 10% of voxels with a normal LNR (P<.01). Conclusions: Pre-RT LNR-0.4 in GBM

  13. High signal intensity of intervertebral calcified disks on T1-weighted MR images resulting from fat content

    Malghem, Jacques; Lecouvet, Frederic E.; Berg, Bruno C. Vande; Duprez, Thierry; Cosnard, Guy; Maldague, Baudouin E. [Universite Catholique de Louvain, Cliniques Universitaires St. Luc, Brussels (Belgium); Francois, Robert [Belgian Military Hospital, Department of Rheumatology, Brussels (Belgium)


    To explain a cause of high signal intensity on T1-weighted MR images in calcified intervertebral disks associated with spinal fusion. Magnetic resonance and radiological examinations of 13 patients were reviewed, presenting one or several intervertebral disks showing a high signal intensity on T1-weighted MR images, associated both with the presence of calcifications in the disks and with peripheral fusion of the corresponding spinal segments. Fusion was due to ligament ossifications (n=8), ankylosing spondylitis (n=4), or posterior arthrodesis (n=1). Imaging files included X-rays and T1-weighted MR images in all cases, T2-weighted MR images in 12 cases, MR images with fat signal suppression in 7 cases, and a CT scan in 1 case. Histological study of a calcified disk from an anatomical specimen of an ankylosed lumbar spine resulting from ankylosing spondylitis was examined. The signal intensity of the disks was similar to that of the bone marrow or of perivertebral fat both on T1-weighted MR images and on all sequences, including those with fat signal suppression. In one of these disks, a strongly negative absorption coefficient was focally measured by CT scan, suggesting a fatty content. The histological examination of the ankylosed calcified disk revealed the presence of well-differentiated bone tissue and fatty marrow within the disk. The high signal intensity of some calcified intervertebral disks on T1-weighted MR images can result from the presence of fatty marrow, probably related to a disk ossification process in ankylosed spines. (orig.)

  14. Preliminary clinical results: an analyzing tool for 2D optical imaging in detection of active inflammation in rheumatoid arthritis

    Adi Aizudin Bin Radin Nasirudin, Radin; Meier, Reinhard; Ahari, Carmen; Sievert, Matti; Fiebich, Martin; Rummeny, Ernst J.; No"l, Peter B.


    Optical imaging (OI) is a relatively new method in detecting active inflammation of hand joints of patients suffering from rheumatoid arthritis (RA). With the high number of people affected by this disease especially in western countries, the availability of OI as an early diagnostic imaging method is clinically highly relevant. In this paper, we present a newly in-house developed OI analyzing tool and a clinical evaluation study. Our analyzing tool extends the capability of existing OI tools. We include many features in the tool, such as region-based image analysis, hyper perfusion curve analysis, and multi-modality image fusion to aid clinicians in localizing and determining the intensity of inflammation in joints. Additionally, image data management options, such as the full integration of PACS/RIS, are included. In our clinical study we demonstrate how OI facilitates the detection of active inflammation in rheumatoid arthritis. The preliminary clinical results indicate a sensitivity of 43.5%, a specificity of 80.3%, an accuracy of 65.7%, a positive predictive value of 76.6%, and a negative predictive value of 64.9% in relation to clinical results from MRI. The accuracy of inflammation detection serves as evidence to the potential of OI as a useful imaging modality for early detection of active inflammation in patients with rheumatoid arthritis. With our in-house developed tool we extend the usefulness of OI imaging in the clinical arena. Overall, we show that OI is a fast, inexpensive, non-invasive and nonionizing yet highly sensitive and accurate imaging modality.-

  15. Experimental results and simulations from aperture synthesis three-dimensional radiometric imaging

    Salmon, Neil A.


    This paper presents the theory and algorithm of how a three-dimensional (3D) image can be generated using crosscorrelations of radiometric emission from a source measured using antennas in the near field. An example of how the algorithm is used to create 3D images of emission measured from a noise source is presented, indicating the presence of Fresnel noise and aliasing in the experimental data when the source is moved away from the phase centre. Simulations are presented which reproduce the Fresnel noise as generated by a 3x3x3 array of point sources located at the centre of a 2 metre diameter array of antennas representing a security screening portal. Two methods of reducing the Fresnel noise are presented: 1) a software method which makes successive more accurate estimates of the locations and intensities of sources; 2) a hardware method which reduces the coherence length of the radiation by increasing the radiation bandwidth.

  16. Horizon Acquisition for Attitude Determination Using Image Processing Algorithms- Results of HORACE on REXUS 16

    Barf, J.; Rapp, T.; Bergmann, M.; Geiger, S.; Scharf, A.; Wolz, F.


    The aim of the Horizon Acquisition Experiment (HORACE) was to prove a new concept for a two-axis horizon sensor using algorithms processing ordinary images, which is also operable at high spinning rates occurring during emergencies. The difficulty to cope with image distortions, which is avoided by conventional horizon sensors, was introduced on purpose as we envision a system being capable of using any optical data. During the flight on REXUS1 16, which provided a suitable platform similar to the future application scenario, a malfunction of the payload cameras caused severe degradation of the collected scientific data. Nevertheless, with the aid of simulations we could show that the concept is accurate (±0.6°), fast (~ lOOms/frame) and robust enough for coarse attitude determination during emergencies and also applicable for small satellites. Besides, technical knowledge regarding the design of REXUS-experiments, including the detection of interferences between SATA and GPS, was gained.

  17. Light and temperature effects on δ11B and B / Ca ratios of the zooxanthellate coral Acropora sp.: results from culturing experiments

    P. Louvat


    Full Text Available The boron isotopic composition (δ11B of marine carbonates (e.g. corals is increasingly utilised as a proxy for paleo-pH, with the strong correlation between δ11B of marine calcifiers and seawater pH now well documented. However, the potential roles of other environmental parameters that may also influence both the boron isotopic composition and boron concentration into coral aragonite are poorly known. To overcome this, the tropical scleractinian coral Acropora sp. was cultured under 3 different temperatures (22, 25 and 28 °C and two light conditions (200 and 400 μmol photon m−2 s−1. The δ11B indicates an increase in internal pH that is dependent on the light conditions. Changes in light intensities from 200 to 400 μmol photon m−2 s−1 seem to indicate an apparent decrease in pH at the site of calcification, contrary to what is expected in most models of light-enhanced calcification. Thus, variations in light conditions chosen to mimic average annual variations of the natural environments where Acropora sp. colonies can be found could bias pH reconstructions by about 0.05 units. For both light conditions, a significant impact of temperature on δ11B can be observed between 22 and 25 °C, corresponding to an increase of about 0.02 pH-units, while no further δ11B increase can be observed from 25 to 28 °C. This non-linear temperature effect complicates the determination of a correction factor. B / Ca ratios decrease with increasing light, consistent with the decrease in pH at the site of calcification under enhanced light intensities. When all the other parameters are constant, boron concentrations in Acropora sp. increase with increasing temperatures and increasing carbonate ion concentrations. These observations contradict previous studies where B / Ca in corals was found to vary inversely with temperature, suggesting that the controlling factors driving boron concentrations have not yet been adequately identified and might be

  18. Preliminary Results on Different Impedance Contrast Agents for Pulmonary Perfusion Imaging with Electrical Impedance Tomography

    Nguyen, D. T.; Kosobrodov, R.; Barry, M. A.; Chik, W.; Pouliopoulos, J.; Oh, T. I.; Thiagalingam, A.; McEwan, A.


    Recent studies in animal models suggest that the use of small volume boluses of NaCl as an impedance contrast agent can significantly improve pulmonary perfusion imaging by Electrical Impedance Tomography (EIT). However, these studies used highly concentrated NaCl solution (20%) which may have adverse effects on the patients. In a pilot experiment, we address this problem by comparing a number of different Impedance Contrast Boluses (ICBs). Conductivity changes in the lungs of a sheep after the injection of four different ICBs were compared, including three NaCl-based ICBs and one glucose-based ICB. The following procedure was followed for each ICB. Firstly, ventilation was turned off to provide an apneic window of approximately 40s to image the conductivity changes due to the ICB. Each ICB was then injected through a pig-tail catheter directly into the right atrium. EIT images were acquired throughout the apnea to capture the conductivity change. For each ICB, the experiment was repeated three times. The three NaCl-based ICB exhibited similar behaviour in which following the injection of each of these ICBs, the conductivity of each lung predictably increased. The effect of the ICB of 5% glucose solution was inconclusive. A small decrease in conductivity in the left lung was observed in two out of three cases and none was discernible in the right lung.

  19. Latest Results from the DODO Survey: Imaging Planets around White Dwarfs

    Hogan, E; Clarke, F J


    The aim of the Degenerate Objects around Degenerate Objects (DODO) survey is to search for very low mass brown dwarfs and extrasolar planets in wide orbits around white dwarfs via direct imaging. The direct detection of such companions would allow the spectroscopic investigation of objects with temperatures lower (< 500 K) than the coolest brown dwarfs currently observed. The discovery of planets around white dwarfs would prove that such objects can survive the final stages of stellar evolution and place constraints on the frequency of planetary systems around their progenitors (with masses between 1.5 - 8 M*, i.e., early B to mid-F). An increasing number of planetary mass companions have been directly imaged in wide orbits around young main sequence stars. For example, the planets around HR 8799 and 1RXS J160929.1 - 210524 are in wide orbits of 24 - 68 AU and 330 AU, respectively. The DODO survey has the ability to directly image planets in post-main sequence analogues of these systems. These proceedings ...

  20. A new volumetric CT machine for dental imaging based on the cone-beam technique: preliminary results

    Mozzo, P. [Dept. of Medical Physics, University Hospital, Verona (Italy); Procacci, C.; Tacconi, A.; Tinazzi Martini, P.; Bergamo Andreis, I.A. [Dept. of Radiology, University Hospital, Verona (Italy)


    The objective of this paper is to present a new type of volumetric CT which uses the cone-beam technique instead of traditional fan-beam technique. The machine is dedicated to the dento-maxillo-facial imaging, particularly for planning in the field of implantology. The main characteristics of the unit are presented with reference to the technical parameters as well as the software performance. Images obtained are reported as various 2D sections of a volume reconstruction. Also, measurements of the geometric accuracy and the radiation dose absorbed by the patient are obtained using specific phantoms. Absorbed dose is compared with that given off by spiral CT. Geometric accuracy, evaluated with reference to various reconstruction modalities and different spatial orientations, is 0.8-1 % for width measurements and 2.2 % for height measurements. Radiation dose absorbed during the scan shows different profiles in central and peripheral axes. As regards the maximum value of the central profile, dose from the new unit is approximately one sixth that of traditional spiral CT. The new system appears to be very promising in dento-maxillo-facial imaging and, due to the good ratio between performance and low cost, together with low radiation dose, very interesting in view of large-scale use of the CT technique in such diagnostic applications. (orig.) With 10 figs., 3 tabs., 15 refs.

  1. SYSIPHE system: a state of the art airborne hyperspectral imaging system: initial results from the first airborne campaign

    Rousset-Rouviere, Laurent; Coudrain, Christophe; Fabre, Sophie; Poutier, Laurent; Løke, Trond; Fridman, Andrei; Blaaberg, Søren; Baarstad, Ivar; Skauli, Torbjorn; Mocoeur, Isabelle


    SYSIPHE is an airborne hyperspectral imaging system, result of a cooperation between France (Onera and DGA) and Norway (NEO and FFI). It is a unique system by its spatial sampling -0.5m with a 500m swath at a ground height of 2000m- combined with its wide spectral coverage -from 0.4μm to 11.5μm in the atmospheric transmission bands. Its infrared component, named SIELETERS, consists in two high étendue imaging static Fourier transform spectrometers, one for the midwave infrared and one for the longwave infrared. These two imaging spectrometers are closely similar in design, since both are made of a Michelson interferometer, a refractive imaging system, and a large IRFPA (1016x440 pixels). Moreover, both are cryogenically cooled and mounted on their own stabilization platform which allows the line of sight to be controlled and recorded. These data are useful to reconstruct and to georeference the spectral image from the raw interferometric images. The visible and shortwave infrared component, named Hyspex ODIN-1024, consists of two spectrographs for VNIR and SWIR based on transmissive gratings. These share a common fore-optics and a common slit, to ensure perfect registration between the VNIR and the SWIR images. The spectral resolution varies from 5nm in the visible to 6nm in the shortwave infrared. In addition, the STAD, the post processing and archiving system, is developed to provide spectral reflectance and temperature products (SRT products) from calibrated georeferenced and inter-band registered spectral images at the sensor level acquired and pre-processed by SIELETERS and Hyspex ODIN-1024 systems.

  2. Major liver resection results in a changed plasma amino acid pattern as reflected by a decreased Fischer ratio which improves by bactericidal/permeability increasing protein

    Nijveldt, RJ; Wiezer, MJ; Meijer, C; Prins, HA; Muller, MGS; Gouma, DJ; Teerlink, T; van Gulik, TM; Rinkes, IHMB; Tilanus, HW; van de Velde, CJH; Wiggers, T; Zoetmulder, FAN; Scotte, M; Cuesta, MA; Meijer, S; van Leeuwen, PAM


    Background/Aims: Major liver resection results in a high morbidity and mortality, and endotoxin plays a role in post-resection hepatic failure. Severe hepatic failure as seen in hepatitis and cirrhosis may be accompanied by hepatic encephalopathy and is characterized by a typical plasma amino acid p

  3. Higher flexibility in input N:P ratios results in more balanced phosphorus budgets in two long-term experimental agroecosystems

    Inefficient phosphorus (P) use in intensive agriculture is common in both organic and conventional systems, resulting in P overapplication and soil P build-up. Increasing crop P removal and P recycling within farming systems (e.g., via cover crops) and reducing P inputs can improve farm P balances. ...

  4. Metabolic Tumor Volume as a Prognostic Imaging-Based Biomarker for Head-and-Neck Cancer: Pilot Results From Radiation Therapy Oncology Group Protocol 0522

    Schwartz, David L., E-mail: [Department of Radiation Oncology, University of Texas Southwestern School of Medicine, Dallas, Texas (United States); Harris, Jonathan [Radiation Therapy Oncology Group Statistical Center, Philadelphia, Pennsylvania (United States); Yao, Min [Department of Radiation Oncology, Case Western Reserve University School of Medicine, Cleveland, Ohio (United States); Rosenthal, David I. [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Opanowski, Adam; Levering, Anthony [American College of Radiology Imaging Network, Philadelphia, Pennsylvania (United States); Ang, K. Kian [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Trotti, Andy M. [Department of Radiation Oncology, Moffitt Cancer Center, Tampa, Florida (United States); Garden, Adam S. [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Jones, Christopher U. [Sutter Medical Group, Sacramento, California (United States); Harari, Paul [Department of Human Oncology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin (United States); Foote, Robert [Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota (United States); Holland, John [Department of Radiation Medicine, Oregon Health & Science University, Portland, Oregon (United States); Zhang, Qiang [Radiation Therapy Oncology Group Statistical Center, Philadelphia, Pennsylvania (United States); Le, Quynh-Thu [Department of Radiation Oncology, Stanford University School of Medicine, Palo Alto, California (United States)


    Purpose: To evaluate candidate fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) imaging biomarkers for head-and-neck chemoradiotherapy outcomes in the cooperative group trial setting. Methods and Materials: Radiation Therapy Oncology Group (RTOG) protocol 0522 patients consenting to a secondary FDG-PET/CT substudy were serially imaged at baseline and 8 weeks after radiation. Maximum standardized uptake value (SUVmax), SUV peak (mean SUV within a 1-cm sphere centered on SUVmax), and metabolic tumor volume (MTV) using 40% of SUVmax as threshold were obtained from primary tumor and involved nodes. Results: Of 940 patients entered onto RTOG 0522, 74 were analyzable for this substudy. Neither high baseline SUVmax nor SUVpeak from primary or nodal disease were associated with poor treatment outcomes. However, primary tumor MTV above the cohort median was associated with worse local-regional control (hazard ratio 4.01, 95% confidence interval 1.28-12.52, P=.02) and progression-free survival (hazard ratio 2.34, 95% confidence interval 1.02-5.37, P=.05). Although MTV and T stage seemed to correlate (mean MTV 6.4, 13.2, and 26.8 for T2, T3, and T4 tumors, respectively), MTV remained a strong independent prognostic factor for progression-free survival in bivariate analysis that included T stage. Primary MTV remained prognostic in p16-associated oropharyngeal cancer cases, although sample size was limited. Conclusion: High baseline primary tumor MTV was associated with worse treatment outcomes in this limited patient subset of RTOG 0522. Additional confirmatory work will be required to validate primary tumor MTV as a prognostic imaging biomarker for patient stratification in future trials.

  5. MR imaging and MR spectroscopy for characterization of cardiomyopathies in adolescents - preliminary results; MR-Bildgebung und MR-Spektroskopie zur Charakterisierung von Kardiomyopathien bei Jugendlichen - erste Ergebnisse

    Beer, M.; Buchner, S.; Fuchs, J.; Machann, W.; Ritter, C.O.; Beissert, M.; Darge, K.; Hahn, D.; Koestler, H. [Inst. fuer Roentgendiagnostik, Universitaetsklinikum Wuerzburg (Germany); Wirbelauer, J. [Kinderklinik und Poliklinik, Universitaetsklinikum Wuerzburg (Germany)


    Purpose: Cardiomyopathy is a rare but life-threatening disease in children and adolescents. Recent studies reported morphological, functional or metabolic alterations of the heart. We discuss a combined MR imaging and {sup 31}P MR spectroscopy (MRS) protocol allowing the analysis of interdependencies between these parameters. Since normal values of cardiac MR parameters in this age group are not available, we included studies of age-matched healthy adolescents. Materials and Methods: 2D-CINE was used to assess left ventricular (LV) parameters. Additional 3D-Chemical Shift Imaging (3D-CSI) and Spectral Localization with Optimal Pointspread Function (SLOOP) reconstruction allowed quantification of the cardiac energy metabolism. Patients (n = 4; all male; age 16.8 {+-} 2.9 years) were included on the basis of an echocardiographic diagnosis of possible cardiomyopathy. The same protocol was applied to healthy young volunteers (n = 4; 1 female, 3 male; age 15.5 {+-} 0.6 years). Results: The patients had a significantly higher LV mass index compared to the control group (147 {+-} 41 g/m2 versus 97 {+-} 16 g/m2; p = 0.04). The other LV parameters (including LV EF with 59 {+-} 22 % versus 67 {+-} 10 %) showed no significant differences. The phosphocreatine to adenosine triphosphate ratio (PCr/ATP-ratio) of the patients was reduced to 1.71 {+-} 0.40 versus 2.44 {+-} 0.30 (p = 0.01), combined with a tendency towards decreased PCr concentrations of 9.1 {+-} 2.5 versus 7.9 {+-} 1.0 mmol/kg. Conclusion: The combination of {sup 31}P MR spectroscopy and MR imaging allows quantitative determination of morphologic, functional and metabolic alterations in adolescents with suspected cardiomyopathy in one examination procedure. The reduction of energy metabolism combined with unaltered global function may indicate a primary role of metabolism in the pathogenesis of cardiomyopathies in adolescents. (orig.)

  6. Note: Upgrade of electron cyclotron emission imaging system and preliminary results on HL-2A tokamak

    Jiang, M., E-mail:; Shi, Z. B.; Zhong, W. L.; Chen, W.; Liu, Z. T.; Ding, X. T.; Yang, Q. W.; Zhang, B. Y.; Shi, P. W.; Liu, Y.; Fu, B. Z.; Xu, Y. [Southwestern Institute of Physics, P.O. Box 432, Chengdu 610041 (China); Domier, C. W.; Luhmann, N. C. [Department of Electrical and Computer Engineering, University of California, Davis, California 95616 (United States); Yang, Z. C. [School of Physics and Chemistry, Xihua University, Chengdu 610039 (China)


    The electron cyclotron emission imaging system on the HL-2A tokamak has been upgraded to 24 (poloidally) × 16 (radially) channels based on the previous 24 × 8 array. The measurement region can be flexibly shifted due to the independence of the two local oscillator sources, and the field of view can be adjusted easily by changing the position of the zoom lenses. The temporal resolution is about 2.5 μs and the achievable spatial resolution is 1 cm. After laboratory calibration, it was installed on HL-2A tokamak in 2014, and the local 2D mode structures of MHD activities were obtained for the first time.

  7. The impact of audio-visual biofeedback on 4D PET images: Results of a phantom study

    Yang, Jaewon; Yamamoto, Tokihiro; Cho, Byungchul; Seo, Youngho; Keall, Paul J.


    Purpose: Irregular breathing causes motion blurring artifacts in 4D PET images. Audiovisual (AV) biofeedback has been demonstrated to improve breathing regularity. To investigate the hypothesis that, compared with free breathing, motion blurring artifacts are reduced with AV biofeedback, the authors performed the first experimental phantom-based quantification of the impact of AV biofeedback on 4D PET image quality. Methods: The authors acquired 4D PET dynamic phantom images with AV biofeedback and free breathing by moving a phantom programmed with AV biofeedback trained and free breathing respiratory traces of ten healthy subjects. The authors also acquired stationary phantom images for reference. The phantom was cylindrical with six hollow sphere targets (10, 13, 17, 22, 28, and 37 mm in diameter). The authors quantified motion blurring using the target diameter, Dice coefficient and recovery coefficient (RC) metrics to estimate the effect of motion. Results: The average increase in target diameter for AV biofeedback was 0.6±1.6mm(4.7±13%), which was significantly (pbiofeedback was 0.90±0.07, which was significantly (pbiofeedback were consistently higher than those for free breathing and comparable to those for stationary targets. However, for RCs the impact of target sizes was more dominant than that of motion. In addition, the authors observed large variations in the results with respect to target sizes, subject traces and respiratory bins due to partial volume effects and respiratory motion irregularity. Conclusions: The results indicate that AV biofeedback can significantly reduce motion blurring artifacts and may facilitate improved identification and localization of lung tumors in 4D PET images. The results justify proceeding with clinical studies to quantify the impact of AV biofeedback on 4D PET image quality and tumor detectability. PMID:22320815

  8. Detection of pericardial inflammation with late-enhancement cardiac magnetic resonance imaging: initial results

    Taylor, Andrew M. [Great Ormond Street Hospital for Children, Cardiothoracic Unit, London (United Kingdom); Gasthuisberg University Hospital, Department of Radiology, Leuven (Belgium); Dymarkowski, Steven; Bogaert, Jan [Gasthuisberg University Hospital, Department of Radiology, Leuven (Belgium); Verbeken, Eric K. [Gasthuisberg University Hospital, Department of Pathology, Leuven (Belgium)


    To examine the value of late-enhancement cardiac magnetic resonance imaging (MRI) for detection of pericardial inflammation. Late-enhancement cardiac MRI was performed in 16 patients with clinical suspicion of pericardial disease. Pericardial effusion, pericardial thickening and pericardial enhancement were assessed. MRI findings were compared with those of definitive pericardial histology (n=14) or microbiology (n=2). A control group of 12 patients with no clinical evidence of pericardial disease were also imaged with the same MRI protocol. Sensitivity and specificity for late-enhancement MRI detection of pericardial inflammation was of 100%. There was MRI late enhancement of the pericardial layers in all five patients with histological/microbiological evidence of inflammatory pericarditis. MRI demonstrated no pericardial thickening and no MRI late enhancement with or without a pericardial effusion in any of the five patients with histological evidence of a normal pericardium. MRI detected pericardial thickening in the absence of both pericardial effusion and late enhancement in all six patients with histological evidence of chronic fibrosing pericarditis. The 12 control subjects showed no evidence of pericardial MRI late enhancement. These findings demonstrate that MRI late enhancement can be used to visualize pericardial inflammation in patients with clinical suspicion of pericardial disease. (orig.)

  9. Assessment of liver steatosis in chicken by using acoustic radiation force impulse imaging: preliminary results

    Guzman Aroca, Florentina; Serrano, Laura; Berna-Serna, Juan D.; Reus, Manuel [Virgen de la Arrixaca University Hospital, Department of Radiology, El Palmar, Murcia (Spain); Ayala, Ignacio [University of Murcia, Department of Animal Medicine and Surgery, Murcia (Spain); Castell, Maria T. [University of Murcia, Department of Cell Biology, Murcia (Spain); Garcia-Perez, Bartolome [Virgen de la Arrixaca University Hospital, Internal Medicine Service, El Palmar, Murcia (Spain)


    To evaluate acoustic radiation force impulse (ARFI) imaging as a non-invasive tool for quantification of the grades of liver steatosis in chickens. We used two different diets: a standard diet (SD group) and a hyperlipidaemic diet (HD group). The ARFI technique was performed in all the animals in the right hepatic lobe and shear wave velocity (SWV) was measured and expressed in metres per second (m/s). Plasma lipid levels were analysed. Steatosis was quantified by using semiquantitative analysis. Statistical analysis was used and Pearson's correlation coefficient was calculated. Mean SWV was 0.94 {+-} 0.16 m/s (range 0.8-1.3 m/s) in the SD group and 1.91 {+-} 0.25 m/s (range 1.3-2.2 m/s) in the HD group (p < 0.001). The lowest SWVs ({<=}1.3 m/s) corresponded to the chickens in the SD group, with 100% of the animals returning a score of 0, whereas the range of SWV in the HD group chickens was between 1.6 and 2.2 m/s. A substantial correlation was observed between SWVs with histological semiquantitative analysis of steatosis (r = 0.85, p < 0.001). ARFI imaging is a non-invasive diagnostic tool that allows discrimination between the grades of liver steatosis in chickens. (orig.)

  10. Image guided adaptive brachytherapy with combined intracavitary and interstitial technique improves the therapeutic ratio in locally advanced cervical cancer: Analysis from the retroEMBRACE study

    LU, Fokdal; Sturdza, Alina; Mazeron, Renaud


    Background and purpose Image guided adaptive brachytherapy (IGABT) using intracavitary applicators (IC) has led to a significant improvement of local control in locally advanced cervical cancer (LACC). Further improvement has been obtained with combined intracavitary/interstitial (IC/IS) applicat......Background and purpose Image guided adaptive brachytherapy (IGABT) using intracavitary applicators (IC) has led to a significant improvement of local control in locally advanced cervical cancer (LACC). Further improvement has been obtained with combined intracavitary/interstitial (IC...

  11. Quantitative Sodium MR Imaging at 7 T: Initial Results and Comparison with Diffusion-weighted Imaging in Patients with Breast Tumors.

    Zaric, Olgica; Pinker, Katja; Zbyn, Stefan; Strasser, Bernhard; Robinson, Simon; Minarikova, Lenka; Gruber, Stephan; Farr, Alex; Singer, Christian; Helbich, Thomas H; Trattnig, Siegfried; Bogner, Wolfgang


    Purpose To investigate the clinical feasibility of a quantitative sodium 23 ((23)Na) magnetic resonance (MR) imaging protocol developed for breast tumor assessment and to compare it with 7-T diffusion-weighted imaging (DWI). Materials and Methods Written informed consent in this institutional review board-approved study was obtained from eight healthy volunteers and 17 patients with 20 breast tumors (five benign, 15 malignant). To achieve the best image quality and reproducibility, the (23)Na sequence was optimized and tested on phantoms and healthy volunteers. For in vivo quantification of absolute tissue sodium concentration (TSC), an external phantom was used. Static magnetic field, or B0, and combined transmit and receive radiofrequency field, or B1, maps were acquired, and image quality, measurement reproducibility, and accuracy testing were performed. Bilateral (23)Na and DWI sequences were performed before contrast material-enhanced MR imaging in patients with breast tumors. TSC and apparent diffusion coefficient (ADC) were calculated and correlated for healthy glandular tissue and benign and malignant lesions. Results The (23)Na MR imaging protocol is feasible, with 1.5-mm in-plane resolution and 16-minute imaging time. Good image quality was achieved, with high reproducibility (mean TSC values ± standard deviation for the test, 36 mmol per kilogram of wet weight ± 2 [range, 34-37 mmol/kg]; for the retest, 37 mmol/kg ± 1 [range, 35-39 mmol/kg]; P = .610) and accuracy (r = 0.998, P breast tissue were 35 mmol/kg ± 3 and 18 mmol/kg ± 3, respectively. In malignant lesions (mean size, 31 mm ± 24; range, 6-92 mm), the TSC of 69 mmol/kg ± 10 was, on average, 49% higher than that in benign lesions (mean size, 14 mm ± 12; range, 6-35 mm), with a TSC of 47 mmol/kg ± 8 (P = .002). There were similar ADC differences between benign ([1.78 ± 0.23] × 10(-3) mm(2)/sec) and malignant ([1.03 ± 0.23] × 10(-3) mm(2)/sec) tumors (P = .002). ADC and TSC were

  12. 123I-FP-CIT brain SPECT (DaTSCAN imaging in the diagnosis of patients with movement disorders: First results

    Jauković Ljiljana


    Full Text Available Background/Aim. 123I-FP-CIT brain single-photon emission computed tomography (SPECT, DaTSCAN imaging, offers a possibility to study structural and biochemical integrity of presinaptic dopaminergic neurotransmitter system. The aim of this study was to evaluate the usefulness of 123I-FP-CIT brain SPECT scintigraphy in patients with extrapyramidal diseases. Methods. Fifteen patients (8 males and 7 females, aged 26-81 years, presenting with extrapyramidal symptoms entered the study. Out of them, 7 patients were diagnosed with definite clinical form of idiopathic Parkinson’s disease (PD or clinical probable for PD clinical stage 2-4 using the Hoehn&Yahr scale (H&Y; 6 patients were with atypical parkinsonism (AP, 1 patient with essential, and 1 with psychogenic tremor. SPECT was performed 180 min after injection of 185 MBq 123IFP- CIT using a dual head Gamma camera. Sixty four one minutes’ frames were acquired using a noncircular rotation mode into a 128 × 128 image matrix. Transverse slices were reconstructed using a 0.6 order Butterworth filter. Visual interpretation was based on striatal uptake, left to right asymmetry and substructures most affected. The ratio of binding for the entire striatum, caudate and putamen to nonspecific binding in occipital cortex was calculated. SPECT findings were categorized as normal and abnormal (incipient, moderate and severe presinaptic deficit. Results. 123I-FP-CIT uptake was reduced in the striatum of 6/7 patients with PD and 5/6 patients with AP. Two patients with PD and AP showed a negative finding. The remaining 2 negative results were obtained in the patients diagnosed with essential tremor and psychogenic tremor. The mean striato-occipital ratio (SDR of the most affected side was lower in the patients with PD. Conclusion. Our first results confirm the usefulness of 123I-FPCIT brain SPECT in differential diagnosis of extrapyramidal diseases.

  13. DICOM image quantification secondary capture (DICOM IQSC) integrated with numeric results, regions, and curves: implementation and applications in nuclear medicine

    Cao, Xinhua; Xu, Xiaoyin; Voss, Stephan


    In this paper, we describe an enhanced DICOM Secondary Capture (SC) that integrates Image Quantification (IQ) results, Regions of Interest (ROIs), and Time Activity Curves (TACs) with screen shots by embedding extra medical imaging information into a standard DICOM header. A software toolkit of DICOM IQSC has been developed to implement the SC-centered information integration of quantitative analysis for routine practice of nuclear medicine. Primary experiments show that the DICOM IQSC method is simple and easy to implement seamlessly integrating post-processing workstations with PACS for archiving and retrieving IQ information. Additional DICOM IQSC applications in routine nuclear medicine and clinic research are also discussed.

  14. Cardiothoracic ratio and vertebral heart size (VHS to standardize the heart size of the tufted capuchin (Cebus apella Linnaeus, 1758 in computerized radiographic images

    Hermínio J. Rocha-Neto


    Full Text Available Abstract: The VHS and CTR were assessed using computerized thoracic radiographs of ten clinically healthy tufted capuchin monkeys (five males and five females from the Wild Animal Screening Center in São Luís (Centro de Triagem de Animais Silvestres de São Luís-MA-CETAS. Radiographs were taken in laterolateral and dorsoventral projections to calculate the cardiothoracic ratio (VHS and vertebral heart size (CTR. The VHS showed mean values of 9.34±0.32v (males and 9.16±0.34v (females and there was no statistical difference between males and females (p>0.05. The CTR showed mean values of 0.55±0.04 (males and 0.52±0.03 (females and there was no statistical difference between the sexes (p>0.05. There was positive correlation between VHS and CTR (r=0.78. The thoracic and heart diameters showed mean values of 5.70±0.48cm and 2.16±0.40cm in the males, respectively. In the females they measured 5.32±0.39cm and 2.94±0.32cm. There was no statistical difference between the sexes. Our results show that the high correlation found between VHS and CTR permitted the verification with similar clinical precision between the two methods to estimate alterations in the heart silhouette by radiographic examination of tufted capuchin, making it an easy technique to apply that can be considered in the investigation of heart problems for this wild species.

  15. The Manchester occulting mask imager (MOMI) first results on the environment of P Cygni

    O'Connor, J; Bryce, M


    The design and first use of the Manchester occulting mask imager (MOMI) is described. This device, when combined with the Cassegrain or Ritchey-Chretien foci of large telescopes, is dedicated to the imagery of faint line emission regions around bright central sources. Initial observations, with MOMI on the Nordic Optical telescope (NOT), of the V=4.8 mag P~Cygni environment, have revealed a $\\geq$~5~arcmin long [NII] 6584A emitting filament projecting from the outer nebular shell of this luminous blue variable (LBV) star. The presence of a mono-polar lobe older than both the inner (22 arcsec diameter) and outer (1.6 arcmin diameter) shells is suggested.

  16. Pancam multispectral imaging results from the Spirit Rover at Gusev crater

    Bell, J.F.; Squyres, S. W.; Arvidson, R. E.; Arneson, H.M.; Bass, D.; Blaney, D.; Cabrol, N.; Calvin, W.; Farmer, J.; Farrand, W. H.; Goetz, W.; Golombek, M.; Grant, J. A.; Greeley, R.; Guinness, E.; Hayes, A.G.; Hubbard, M.Y.H.; Herkenhoff, K. E.; Johnson, M.J.; Johnson, J. R.; Joseph, J.; Kinch, K.M.; Lemmon, M.T.; Li, R.; Madsen, M.B.; Maki, J.N.; Malin, M.; McCartney, E.; McLennan, S.; McSween, H.Y.; Ming, D. W.; Moersch, J.E.; Morris, R.V.; Dobrea, E.Z.N.; Parker, T.J.; Proton, J.; Rice, J. W.; Seelos, F.; Soderblom, J.; Soderblom, L.A.; Sohl-Dickstein, J. N.; Sullivan, R.J.; Wolff, M.J.; Wang, A.


    Panoramic Camera images at Gusev crater reveal a rock-strewn surface interspersed with high- to moderate-albedo fine-grained deposits occurring in part as drifts or in small circular swales or hollows. Optically thick coatings of fine-grained ferric iron-rich dust dominate most bright soil and rock surfaces. Spectra of some darker rock surfaces and rock regions exposed by brushing or grinding show near-infrared spectral signatures consistent with the presence of mafic silicates such as pyroxene or olivine. Atmospheric observations show a steady decline in dust opacity during the mission, and astronomical observations captured solar transits by the martian moons, Phobos and Deimos, as well as a view of Earth from the martian surface.

  17. New scientific results with SpIOMM: a testbed for CFHT's imaging Fourier transform spectrometer SITELLE

    Drissen, L; Martin, T; Lagrois, D; Rousseau-Nepton, L; Bilodeau, A; Robert, C; Joncas, G; Iglesias-Páramo, J


    We present new data obtained with SpIOMM, the imaging Fourier transform spectrometer attached to the 1.6-m telescope of the Observatoire du Mont-M\\'egantic in Qu\\'ebec. Recent technical and data reduction improvements have significantly increased SpIOMM's capabilities to observe fainter objects or weaker nebular lines, as well as continuum sources and absorption lines, and to increase its modulation efficiency in the near ultraviolet. To illustrate these improvements, we present data on the supernova remnant Cas A, planetary nebulae M27 and M97, the Wolf-Rayet ring nebula M1-67, spiral galaxies M63 and NGC 3344, as well as the interacting pair of galaxies Arp 84.

  18. Single-grain results from an EMCCD-based imaging system

    Thomsen, Kristina Jørkov; Kook, Myung Ho; Murray, Andrew


    accepted into a dose distribution. EMCCD cross-talk is shown to be of concern at low light levels.We also make use of the fact that the EMCCD can observe TL signals from individual grains to examine the use of the correlation between the quartz 110 C TL peak and the fast component OSL signal to correct......Here we compare the performance of an EMCCD-based imaging system with the standard laser-based single-grain Risø attachment. We first compare gamma dose distributions and the relative sensitivity of the two instruments is investigated using a single sample, by comparing the number of grains...... for sensitivity change. Finally, we present the OSL dose distributions from a set of both well-bleached and poorly-bleached sedimentary samples. From a comparison of the measured doses, we conclude that the two instruments give indistinguishable dose estimates and dispersions, despite the fact that the laser...

  19. Antimyosin imaging in acute transmural myocardial infarctions: results of a multicenter clinical trial

    Johnson, L.L.; Seldin, D.W.; Becker, L.C.; LaFrance, N.D.; Liberman, H.A.; James, C.; Mattis, J.A.; Dean, R.T.; Brown, J.; Reiter, A.


    Murine monoclonal antimyosin antibody has been shown experimentally to bind selectively to irreversibly damaged myocytes. To evaluate the safety and efficacy of monoclonal antimyosin for identifying acute transmural infarction, 50 patients with acute Q wave myocardial infarction were entered into a phase I/II multicenter trial involving three clinical sites. Indium-111 antimyosin was prepared from an instant kit formulation containing 0.5 mg of diethylene triamine pentaacetic acid (DTPA)-coupled Fab fragment (R11D10) and 1.2 to 2.4 mCi of indium-111. Average labeling efficiency was 92%. Antimyosin was injected 27 +/- 16 h after the onset of chest pain. Planar or tomographic imaging was performed 27 +/- 9 h after injection in all patients, and repeat imaging was done 24 h later in 39 patients. Of the 50 patients entered, 46 showed myocardial uptake of antimyosin (sensitivity 92%). Thirty-one of 39 planar scans performed at 24 h were diagnostic; 8 showed persistent blood pool activity that cleared by 48 h. Focal myocardial uptake of antimyosin corresponded to electrocardiographic infarct localization. No patient had an adverse reaction to antimyosin. In addition, 125 serum samples, including 21 collected greater than 42 days after injection, were tested for human antimouse antibodies, and all samples were assessed as having undetectable titers. Intensity of antimyosin uptake was correlated with infarct location and the presence or absence of collateral vessels. There was a significant correlation between faint uptake and inferoposterior infarct location. In 21 patients who had coronary angiography close to the time of antimyosin injection, there was a significant correlation between faint tracer uptake and closed infarct-related vessel with absent collateral flow.

  20. Impact of Anesthesia Protocols on In Vivo Bioluminescent Bacteria Imaging Results.

    Thomas Chuzel

    Full Text Available Infectious murine models greatly benefit from optical imaging using bioluminescent bacteria to non-invasively and repeatedly follow in vivo bacterial infection. In this context, one of the most critical parameters is the bioluminescence sensitivity to reliably detect the smallest number of bacteria. Another critical point is the anesthetic approaches that have been demonstrated to impact the bioluminescence flux emission in studies with luciferase-transfected tumor cells. However, this impact has never been assessed on bacteria bioluminescent models. To this end, we investigated the effects of four anesthesia protocols on the bioluminescence flux in a central venous catheter murine model (SKH1-hr(hr mice infected by a bioluminescent S. aureus Xen36 strain. Bioluminescence imaging was performed on mice anesthetized by either ketamine/xylazine (with or without oxygen supplementation, or isoflurane carried with air or oxygen. Total flux emission was determined in vivo daily for 3 days and ex vivo at the end of the study together with a CFU counting of the biofilm in the catheter. Bioluminescence flux differences appear between the different anesthetic protocols. Using a ketamine/xylazine anesthesia (with air, bacteria detection was impossible since the bioluminescence signal remains in the background signal. Mice anesthetized with isoflurane and oxygen led to a signal significantly higher to the background all along the kinetics. The use of isoflurane in air presents a bioluminescence signal similar to the use of ketamine/xylazine with oxygen. These data highlight the importance of oxygen to improve bioluminescence flux by bacteria with isoflurane as well as with ketamine/xylazine anesthetics. As a conclusion, we recommend the use of isoflurane anesthetic with oxygen to increase the bioluminescence sensitivity in this kind of study.

  1. Impact of Anesthesia Protocols on In Vivo Bioluminescent Bacteria Imaging Results.

    Chuzel, Thomas; Sanchez, Violette; Vandamme, Marc; Martin, Stéphane; Flety, Odile; Pager, Aurélie; Chabanel, Christophe; Magnier, Luc; Foskolos, Marie; Petit, Océane; Rokbi, Bachra; Chereul, Emmanuel


    Infectious murine models greatly benefit from optical imaging using bioluminescent bacteria to non-invasively and repeatedly follow in vivo bacterial infection. In this context, one of the most critical parameters is the bioluminescence sensitivity to reliably detect the smallest number of bacteria. Another critical point is the anesthetic approaches that have been demonstrated to impact the bioluminescence flux emission in studies with luciferase-transfected tumor cells. However, this impact has never been assessed on bacteria bioluminescent models. To this end, we investigated the effects of four anesthesia protocols on the bioluminescence flux in a central venous catheter murine model (SKH1-hr(hr) mice) infected by a bioluminescent S. aureus Xen36 strain. Bioluminescence imaging was performed on mice anesthetized by either ketamine/xylazine (with or without oxygen supplementation), or isoflurane carried with air or oxygen. Total flux emission was determined in vivo daily for 3 days and ex vivo at the end of the study together with a CFU counting of the biofilm in the catheter. Bioluminescence flux differences appear between the different anesthetic protocols. Using a ketamine/xylazine anesthesia (with air), bacteria detection was impossible since the bioluminescence signal remains in the background signal. Mice anesthetized with isoflurane and oxygen led to a signal significantly higher to the background all along the kinetics. The use of isoflurane in air presents a bioluminescence signal similar to the use of ketamine/xylazine with oxygen. These data highlight the importance of oxygen to improve bioluminescence flux by bacteria with isoflurane as well as with ketamine/xylazine anesthetics. As a conclusion, we recommend the use of isoflurane anesthetic with oxygen to increase the bioluminescence sensitivity in this kind of study.

  2. Diffusion tensor imaging and fiber tractography in cervical compressive myelopathy: preliminary results

    Lee, Joon Woo; Kim, Jae Hyoung; Park, Jong Bin; Lee, Guen Young; Kang, Heung Sik [Seoul National University Bundang Hospital, Department of Radiology, Gyeonggi-do (Korea, Republic of); Park, Kun Woo; Yeom, Jin S. [Seoul National University Bundang Hospital, Department of Orthopaedic Surgery, Gyeonggi-Do (Korea, Republic of)


    To assess diffusion tensor imaging (DTI) parameters in cervical compressive myelopathy (CCM) patients compared to normal volunteers, to relate them with myelopathy severity, and to relate tractography patterns with postoperative neurologic improvement. Twenty patients suffering from CCM were prospectively enrolled (M:F = 13:7, mean age, 49.6 years; range 22-67 years) from September 2009 to March 2010. Sensitivity encoding (SENSE) single-shot echo-planar imaging (EPI) was used for the sagittal DTI. Twenty sex- and age-matched normal volunteers underwent the same scanning procedure. Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values in the spinal cord were compared between the patients and normal volunteers and were related to myelopathy severity based on Japanese Orthopedic Association (JOA) scores. Tractography patterns were related to myelopathy severity and postoperative improvement. There were significant differences between patients and normal volunteers in terms of FA (0.498 {+-} 0.114 vs. 0.604 {+-} 0.057; p = 0.001) and ADC (1.442 {+-} 0.389 vs. 1.169 {+-} 0.098; p = 0.001). DTI parameters and tractography patterns were not related to myelopathy severity. In ten patients in the neurologically worse group, postoperative neurologic improvement was seen in four of five patients with intact fiber tracts, but only one of five patients with interrupted fiber tracts exhibited neurologic improvement. DTI parameters in CCM patients were significantly different from those in normal volunteers but were not significantly related to myelopathy severity. The patterns of tractography appear to correlate with postoperative neurologic improvement. (orig.)

  3. High-Ratio Gear Train

    Lefever, A. E.


    Proposed arrangement of two connected planetary differentials results in gear ratio many times that obtainable in conventional series gear assembly of comparable size. Ratios of several thousand would present no special problems. Selection of many different ratios is available with substantially similar gear diameters. Very high gear ratios would be obtained from small mechanism.

  4. A dual-modality photoacoustic and ultrasound imaging system for noninvasive sentinel lymph node detection: preliminary clinical results

    Erpelding, Todd N.; Garcia-Uribe, Alejandro; Krumholz, Arie; Ke, Haixin; Maslov, Konstantin; Appleton, Catherine; Margenthaler, Julie; Wang, Lihong V.


    Sentinel lymph node biopsy (SLNB) has emerged as an accurate, less invasive alternative to axillary lymph node dissection, and it has rapidly become the standard of care for patients with clinically node-negative breast cancer. The sentinel lymph node (SLN) hypothesis states that the pathological status of the axilla can be accurately predicted by determining the status of the first (i.e., sentinel) lymph nodes that drain from the primary tumor. Physicians use radio-labeled sulfur colloid and/or methylene blue dye to identify the SLN, which is most likely to contain metastatic cancer cells. However, the surgical procedure causes morbidity and associated expenses. To overcome these limitations, we developed a dual-modality photoacoustic and ultrasound imaging system to noninvasively detect SLNs based on the accumulation of methylene blue dye. Ultimately, we aim to guide percutaneous needle biopsies and provide a minimally invasive method for axillary staging of breast cancer. The system consists of a tunable dye laser pumped by a Nd:YAG laser, a commercial ultrasound imaging system (Philips iU22), and a multichannel data acquisition system which displays co-registered photoacoustic and ultrasound images in real-time. Our clinical results demonstrate that real-time photoacoustic imaging can provide sensitive and specific detection of methylene blue dye in vivo. While preliminary studies have shown that in vivo detection of SLNs by using co-registered photoacoustic and ultrasound imaging is feasible, further investigation is needed to demonstrate robust SLN detection.

  5. SU-D-17A-04: The Impact of Audiovisual Biofeedback On Image Quality During 4D Functional and Anatomic Imaging: Results of a Prospective Clinical Trial

    Keall, P; Pollock, S [University of Sydney, Sydney (Australia); Yang, J; Diehn, M; Berger, J; Graves, E; Loo, B [Stanford University, Stanford, CA (United States); Yamamoto, T [UC Davis School of Medicine, Sacramento, CA (United States)


    Purpose: The ability of audiovisual (AV) biofeedback to improve breathing regularity has not previously been investigated for functional imaging studies. The purpose of this study was to investigate the impact of AV biofeedback on 4D-PET and 4D-CT image quality in a prospective clinical trial. We hypothesized that motion blurring in 4D-PET images and the number of artifacts in 4D-CT images are reduced using AV biofeedback. Methods: AV biofeedback is a real-time, interactive and personalized system designed to help a patient self-regulate his/her breathing using a patient-specific representative waveform and musical guides. In an IRB-approved prospective clinical trial, 4D-PET and 4D-CT images of 10 lung cancer patients were acquired with AV biofeedback (AV) and free breathing (FB). The 4D-PET images in 6 respiratory bins were analyzed for motion blurring by: (1) decrease of GTVPET and (2) increase of SUVmax in 4-DPET compared to 3D-PET. The 4D-CT images were analyzed for artifacts by: (1) comparing normalized cross correlation-based scores (NCCS); and (2) quantifying a visual assessment score (VAS). A two-tailed paired t-test was used to test the hypotheses. Results: The impact of AV biofeedback on 4D-PET and 4D-CT images varied widely between patients, suggesting inconsistent patient comprehension and capability. Overall, the 4D-PET decrease of GTVPET was 2.0±3.0cm3 with AV and 2.3±3.9cm{sup 3} for FB (p=0.61). The 4D-PET increase of SUVmax was 1.6±1.0 with AV and 1.1±0.8 with FB (p=0.002). The 4D-CT NCCS were 0.65±0.27 with AV and 0.60±0.32 for FB (p=0.32). The 4D-CT VAS was 0.0±2.7 (p=ns). Conclusion: A 10-patient study demonstrated a statistically significant reduction of motion blurring of AV over FB for 1/2 functional 4D-PET imaging metrics. No difference between AV and FB was found for 2 anatomic 4D-CT imaging metrics. Future studies will focus on optimizing the human-computer interface and including patient training sessions for improved

  6. Evaluating the intensity of the acoustic radiation force impulse (ARFI) in intravascular ultrasound (IVUS) imaging: Preliminary in vitro results.

    Shih, Cho-Chiang; Lai, Ting-Yu; Huang, Chih-Chung


    The ability to measure the elastic properties of plaques and vessels is significant in clinical diagnosis, particularly for detecting a vulnerable plaque. A novel concept of combining intravascular ultrasound (IVUS) imaging and acoustic radiation force impulse (ARFI) imaging has recently been proposed. This method has potential in elastography for distinguishing between the stiffness of plaques and arterial vessel walls. However, the intensity of the acoustic radiation force requires calibration as a standard for the further development of an ARFI-IVUS imaging device that could be used in clinical applications. In this study, a dual-frequency transducer with 11MHz and 48MHz was used to measure the association between the biological tissue displacement and the applied acoustic radiation force. The output intensity of the acoustic radiation force generated by the pushing element ranged from 1.8 to 57.9mW/cm(2), as measured using a calibrated hydrophone. The results reveal that all of the acoustic intensities produced by the transducer in the experiments were within the limits specified by FDA regulations and could still displace the biological tissues. Furthermore, blood clots with different hematocrits, which have elastic properties similar to the lipid pool of plaques, with stiffness ranging from 0.5 to 1.9kPa could be displaced from 1 to 4μm, whereas the porcine arteries with stiffness ranging from 120 to 291kPa were displaced from 0.4 to 1.3μm when an acoustic intensity of 57.9mW/cm(2) was used. The in vitro ARFI images of the artery with a blood clot and artificial arteriosclerosis showed a clear distinction of the stiffness distributions of the vessel wall. All the results reveal that ARFI-IVUS imaging has the potential to distinguish the elastic properties of plaques and vessels. Moreover, the acoustic intensity used in ARFI imaging has been experimentally quantified. Although the size of this two-element transducer is unsuitable for IVUS imaging, the

  7. Diagnostic confidence analysis in the magnetic resonance imaging of ovarian and deep endometriosis: comparison with surgical results

    Saba, Luca; Sulcis, Rosa; Ibba, Giannina; Piga, Mario [Azienda Ospedaliero Universitaria, Department of Radiology, Monserrato (Italy); Melis, Gian Benedetto; Guerriero, Stefano [Azienda Ospedaliero Universitaria, Department of Gynecology, Monserrato (Italy); Alcazar, Juan Luis [University of Navarra, Department of Obstetrics and Gynecology, Clinica Universidad de Navarra, Pamplona (Spain)


    To assess the diagnostic confidence of multiple readers in the magnetic resonance imaging (MRI) diagnosis of endometriosis. Sixty-five patients (mean age 33; range 19-45 years) who had undergone MRI were retrospectively evaluated. Five regions were analysed and the presence of endometriosis was scored on a five-point scale in order to assess the diagnostic confidence. Statistical analysis included receiver operating characteristic (ROC) curve analysis, the Cohen weighted test and sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy, positive likelihood ratio (LR+) and negative likelihood ratio (LR-). The areas under the curve (AUC) in the detection of ovarian endometrioma were 0.942, 0.893 and 0.883 for readers 1, 2 and 3, respectively; in the uterosacral ligament (USL) AUCs were 0.907, 0.804 and 0.842; in the vaginal fornix (VF) 0.819, 0.733 and 0.69; in the anterior compartment 0.916, 0.833 and 0.873; and in the rectum/sigma/pouch of Douglas (RSD) 0.936, 0.856 and 0.834. Diagnostic confidence of the observers is different according to the region of the nodules of endometriosis and it can be challenging in the VF and for the less experience readers also in the AC and RSD. Moreover the degree of uncertain diagnosis for the less expert readers may reach up to one third of the examinations. (orig.)

  8. Assessment of Total Suspended Sediment Distribution under Varying Tidal Conditions in Deep Bay: Initial Results from HJ-1A/1B Satellite CCD Images

    Liqiao Tian


    Full Text Available Using Deep Bay in China as an example, an effective method for the retrieval of total suspended sediment (TSS concentration using HJ-1A/1B satellite images is proposed. The factors driving the variation of the TSS spatial distribution are also discussed. Two field surveys, conducted on August 29 and October 26, 2012, showed that there was a strong linear relationship (R2 = 0.9623 between field-surveyed OBS (optical backscatter measurements (5-31NTU and laboratory-analyzed TSS concentrations (9.89–35.58 mg/L. The COST image-based atmospheric correction procedure and the pseudo-invariant features (PIF method were combined to remove the atmospheric effects from the total radiance measurements obtained with different CCDs onboard the HJ-1A/1B satellites. Then, a simple and practical retrieval model was established based on the relationship between the satellite-corrected reflectance band ratio of band 3 and band 2 (Rrs3/Rrs2 and in-situ TSS measurements. The R2 of the regression relationship was 0.807, and the mean relative error (MRE was 12.78%, as determined through in-situ data validation. Finally, the influences of tide cycles, wind factors (direction and speed and other factors on the variation of the TSS spatial pattern observed from HJ-1A/1B satellite images from September through November of 2008 are discussed. The results show that HJ-1A/1B satellite CCD images can be used to estimate TSS concentrations under different tides in the study area over synoptic scales without using simultaneous in-situ atmospheric parameters and spectrum data. These findings provide strong informational support for numerical simulation studies on the combined influence of tide cycles and other associated hydrologic elements in Deep Bay.

  9. Evolution of Stellar-to-Halo Mass Ratio at z=0-7 Identified by Clustering Analysis with the Hubble Legacy Imaging and Early Subaru/Hyper Suprime-Cam Survey Data

    Harikane, Yuichi; Ono, Yoshiaki; More, Surhud; Saito, Shun; Lin, Yen-Ting; Coupon, Jean; Shimasaku, Kazuhiro; Shibuya, Takatoshi; Price, Paul A; Lin, Lihwai; Hsieh, Bau-Ching; Ishigaki, Masafumi; Komiyama, Yutaka; Silverman, John; Takata, Tadafumi; Tamazawa, Hiroko; Toshikawa, Jun


    We present clustering analysis results from 10,540 Lyman break galaxies (LBGs) at z~4-7 that are identified in a combination of the Hubble legacy deep imaging and the complimentary large-area Subaru/Hyper Suprime-Cam data taken very recently. We measure angular correlation functions of these LBGs at z~4, 5, 6, and 7, and fit these measurements using halo occupation distribution (HOD) models that provide the estimates of halo masses, M_h~(1-20)x10^11 Msun. Our M_h estimates agree with those obtained by previous clustering studies in a UV-magnitude vs. M_h plane, and allow us to calculate stellar-to-halo mass ratios (SHMRs) of the LBGs. By comparison with the z~0 SHMR given by SDSS, we identify evolution of the SHMR from z~0 to z~4, and z~4 to z~7 at the >98% confidence levels. The SHMR decreases by a factor of ~3 from z~0 to 4, and increase by a factor of ~5 from z~4 to 7. We obtain the baryon conversion efficiency (BCE) of our LBGs at z~4, and find that the BCE increases with increasing dark matter halo mass....

  10. The Slope Imaging Multi-Polarization Photon-Counting Lidar: Development and Performance Results

    Dabney, Phillip


    The Slope Imaging Multi-polarization Photon-counting Lidar is an airborne instrument developed to demonstrate laser altimetry measurement methods that will enable more efficient observations of topography and surface properties from space. The instrument was developed through the NASA Earth Science Technology Office Instrument Incubator Program with a focus on cryosphere remote sensing. The SIMPL transmitter is an 11 KHz, 1064 nm, plane-polarized micropulse laser transmitter that is frequency doubled to 532 nm and split into four push-broom beams. The receiver employs single-photon, polarimetric ranging at 532 and 1064 nm using Single Photon Counting Modules in order to achieve simultaneous sampling of surface elevation, slope, roughness and depolarizing scattering properties, the latter used to differentiate surface types. Data acquired over ice-covered Lake Erie in February, 2009 are documenting SIMPL s measurement performance and capabilities, demonstrating differentiation of open water and several ice cover types. ICESat-2 will employ several of the technologies advanced by SIMPL, including micropulse, single photon ranging in a multi-beam, push-broom configuration operating at 532 nm.

  11. Image-guided multipolar radiofrequency ablation of liver tumours: initial clinical results

    Terraz, Sylvain; Constantin, Christophe; Becker, Christoph D. [Geneva University Hospital, Department of Radiology, Geneva 14 (Switzerland); Majno, Pietro Edoardo; Mentha, Gilles [Geneva University Hospital, Department of Surgery, Geneva 14 (Switzerland); Spahr, Laurent [Geneva University Hospital, Department of Gastroenterology, Geneva 14 (Switzerland)


    The local effectiveness and clinical usefulness of multipolar radiofrequency (RF) ablation of liver tumours was evaluated. Sixty-eight image-guided RF sessions were performed using a multipolar device with bipolar electrodes in 53 patients. There were 45 hepatocellular carcinomas (HCC) and 42 metastases with a diameter {<=}3 cm (n = 55), 3.1-5 cm (n = 29) and >5 cm (n = 3); 26 nodules were within 5 mm from large vessels. Local effectiveness and complications were evaluated after RF procedures. Mean follow-up was 17 {+-} 10 months. Recurrence and survival rates were analysed by the Kaplan-Meier method. The primary and secondary technical effectiveness rate was 82% and 95%, respectively. The major and minor complication rate was 2.9%, respectively. The local tumour progression at 1- and 2-years was 5% and 9% for HCC nodules and 17% and 31% for metastases, respectively; four of 26 nodules (15%) close to vessels showed local progression. The survival at 1 year and 2 years was 97% and 90% for HCC and 84% and 68% for metastases, respectively. Multipolar RF technique creates ablation zones of adequate size and tailored shape and is effective to treat most liver tumours, including those close to major hepatic vessels. (orig.)

  12. Reuven Ramaty High Energy Solar Spectroscope Imager (RHESSI) results analyzed in seasonal quadrants

    Conley, Carolynn Lee

    The Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) Small Explorer Mission was launched on Feb. 5, 2002. RHESSI was designed to collect solar flare and coronal mass ejection data. In addition, for over a decade, RHESSI has also observed lightening generated energetic eruptive events. These were named Terrestrial Gamma Ray Flashes (TGFs) and have been observed since 2002. Data collected shows a distribution of TGFs randomly spread in the latitudes and longitudes that satellites observed. This study investigates the seasonal variation in the RHESSI data. RHESSI TGF data is available since the start of data collection in 2002 to 2012. Observation of this data suggests that a distribution of activity may be observed. The TGF weekly rates are compared at the four seasons, spring, summer, fall, and winter, in the northern and southern hemispheres. The TGF rate may be a function of the relative position of the earth to the sun and relative to the earth's geographic and magnetic poles. The spectra of original interest to RHESSI and other investigations produced by the heliosphere environment are being distinguished from TGFs in the Earth's atmosphere. This analysis of the RHESSI data was performed in preparation for collaborative research with a Space Test Program hosted FireStation experiment operating on the International Space Station.

  13. Current Practice vs. Guideline Based Imaging in Abdominal Radiology in the German Speaking Area: Results of an Online Survey.

    Schreyer, A G; Wessling, J; Grenacher, L


    The working group for abdominal imaging within the German Roentgen Society (DRG) performed an online survey amongst radiologist concerning the current status of techniques for abdominal imaging. The results of this survey were compared with the most recent guidelines. We performed an online survey open for all members of the DRG during a 76-day period with 65 questions and an overall estimated time for finishing the questionnaire of 15 minutes concerning technical specifications for abdominal radiological imaging. The results were evaluated using descriptive statistics. 90 of all participants, who filled out the survey covering more than 80% of the questions, were included in the statistical evaluation. 27% of all participants were registered radiologists while 73% represented radiologists working in a hospital. Most participants worked in a managerial position. The participants gave detailed information regarding the radiological techniques used in dedicated organ systems (esophagus, stomach, pancreas, liver, small intestines, colon) regarding acquired contrast phases and oral and intravenous administration of contrast medium. The results confirm that most radiologists participating in this survey perform their examinations and choose their modalities in conformity with the current existing clinical guidelines. Because most clinical guidelines do not specify radiological examinations in detail, there is a noteworthy heterogeneity of the acquired contrast phases and major divergence in terms of technical parameters. Therefore a joint radiological effort should be initiated for developing and publishing updated radiological parameters for abdominal imaging. • In German speaking countries indications for abdominal radiological examinations are performed with a high compliance to published guidelines. • There is a significant heterogeneity regarding the acquisition of different contrast phases for parenchymal abdominal organs. • There is an urgent need to

  14. Can magnetic resonance imaging at 3.0-Tesla reliably detect patients with endometriosis? Initial results.

    Thomeer, Maarten G; Steensma, Anneke B; van Santbrink, Evert J; Willemssen, Francois E; Wielopolski, Piotr A; Hunink, Myriam G; Spronk, Sandra; Laven, Joop S; Krestin, Gabriel P


    The aim of this study was to determine whether an optimized 3.0-Tesla magnetic resonance imaging (MRI) protocol is sensitive and specific enough to detect patients with endometriosis. This was a prospective cohort study with consecutive patients. Forty consecutive patients with clinical suspicion of endometriosis underwent 3.0-Tesla MRI, including a T2-weighted high-resolution fast spin echo sequence (spatial resolution=0.75 ×1.2 ×1.5 mm³) and a 3D T1-weighted high-resolution gradient echo sequence (spatial resolution=0.75 ×1.2 × 2.0 mm³). Two radiologists reviewed the dataset with consensus reading. During laparoscopy, which was used as reference standard, all lesions were characterized according to the revised criteria of the American Fertility Society. Patient-level and region-level sensitivities and specificities and lesion-level sensitivities were calculated. Patient-level sensitivity was 42% for stage I (5/12) and 100% for stages II, III and IV (25/25). Patient-level specificity for all stages was 100% (3/3). The region-level sensitivity and specificity was 63% and 97%, respectively. The sensitivity per lesion was 61% (90% for deep lesions, 48% for superficial lesions and 100% for endometriomata). The detection rate of obliteration of the cul-the-sac was 100% (10/10) with no false positive findings. The interreader agreement was substantial to perfect (kappa=1 per patient, 0.65 per lesion and 0.71 for obliteration of the cul-the-sac). An optimized 3.0-Tesla MRI protocol is accurate in detecting stage II to stage IV endometriosis. © 2014 The Authors. Journal of Obstetrics and Gynaecology Research © 2014 Japan Society of Obstetrics and Gynecology.

  15. Imaging of pulmonary disease in rheumatoid arthritis using JOO1X scintigraphy: preliminary results

    Goupille, P. [Service de Rhumatologie, Hopital Trousseau, Tours (France); Diot, P. [Service de Pneumologie, Hopital Bretonneau, Tours (France); Valat, J.P. [Service de Rhumatologie, Hopital Trousseau, Tours (France); Lemarie, E. [Service de Pneumologie, Hopital Bretonneau, Tours (France); Valat, C. [Service de Medecine Nucleaire, Hopital Bretonneau, Tours (France); Asquier, E. [Service de Radiologie, Hopital Bretonneau, Tours (France); Delarue, A. [Centre de Developpement Pierre Fabre, Labege (France); Pape, A.L. [Lab. de Biophysique Cellulaire et RMN, INSERM U316, Univ. Tours (France)


    The purpose of this study was to determine the ability of technetium-99m J001X scintigraphy to image active pulmonary involvement in patients suffering from rheumatoid arthritis (RA). J001X is a fully characterized acylated poly(1,3)galactoside, isolated from Klebsiella membranes, which is able to bind recruited macrophages after aerosol administration. J001X scintigraphy was compared with high-resolution computed tomography (HRCT), pulmonary function tests (PFTs) and bronchoalveolar lavage (BAL) in 15 patients suffering from RA. Patients were considered to have pulmonary involvement when they had an interstitial syndrome on HRCT and a decrease of 20% in TCO/VE (transfer coefficient) on PFTs and/or an abnormal BAL (lymphocytosis higher than 20% and/or percentage of neutrophils higher than 10%). Pulmonary involvement was present in eight patients, and absent in seven. Of the eight patients with pulmonary involvement, all had abnormal BAL, two had an interstitial syndrome on HRCT, two had decreased TCO/VE and three had positive J001X scintigraphy. Of the seven patients without pulmonary involvement, six had normal BAL (not available in one), two had an interstitial syndrome on HRCT, one had decreased TCO/VE and two had positive J001X scintigraphy. According to our gold standard of pulmonary involvement, the sensitivity of J001X scintigraphy for the detection of pulmonary involvement in RA was 37.5%, the specificity was 71.4% and the positive predictive value was 60%. The ability of J001X scintigraphy to detect active pulmonary involvement during RA appears unclear in this study but it may detect processes unnoticed by the other modalities. (orig./MG)

  16. MR imaging-guided prostate biopsy: technical features and preliminary results.

    Panebianco, Valeria; Barchetti, Flavio; Manenti, Guglielmo; Aversa, Tommaso; Catalano, Carlo; Simonetti, Giovanni


    Repeatedly negative prostate biopsies in individuals with elevated prostate-specific antigen (PSA) levels can be frustrating for both the patient and the urologist. This study was performed to investigate if magnetic resonance imaging (MRI)-guided transrectal biopsy (MRGB) increases diagnostic performance in individuals with suspected prostate cancer (PCa). Twenty-three consecutive men with a total PSA >4 ng/mL, PSA density >0.15, PSA velocity >0.75 ng/mL/year and suspicious MRI findings were included (average age 64 years; age range 53-75 years; total PSA levels ranging from 4.7 to 54 ng/mL; median 9 ng/mL). MRGB was performed with a closed unit at 1.5 Tesla, an MRI compatible biopsy device, a needle guide, and a titanium double-shoot biopsy gun. At prebiopsy MRI, in the 23 patients, a total of 26 suspicious areas to which the MRGB should be directed were found, 23 of them in the peripheral zone and three in the transitional zone. The needle guide was depicted and could be positioned with MRI guidance in all 23 patients. The duration of the procedure ranged from 35 to 55 min (mean 40 min). MRGB was well tolerated by all patients, and no major complications were observed. The detection rate for the diagnosis of PCa was 80, and 90 % of detected PCa were of intermediate aggressiveness. MRGB has the potential to improve cancer detection rates in men with suspected PCa to deliver the relevant treatment as soon as possible.

  17. Biliary tract visualization using near-infrared imaging with indocyanine green during laparoscopic cholecystectomy: results of a systematic review.

    Vlek, S L; van Dam, D A; Rubinstein, S M; de Lange-de Klerk, E S M; Schoonmade, L J; Tuynman, J B; Meijerink, W J H J; Ankersmit, M


    Near-infrared imaging with indocyanine green (ICG) has been extensively investigated during laparoscopic cholecystectomy (LC). However, methods vary between studies, especially regarding patient selection, dosage and timing. The aim of this systematic review was to evaluate the potential of the near-infrared imaging technique with ICG to identify biliary structures during LC. A comprehensive systematic literature search was performed. Prospective trials examining the use of ICG during LC were included. Primary outcome was biliary tract visualization. Risk of bias was assessed using ROBINS-I. Secondly, a meta-analysis was performed comparing ICG to intraoperative cholangiography (IOC) for identification of biliary structures. GRADE was used to assess the quality of the evidence. Nineteen studies were included. Based upon the pooled data from 13 studies, cystic duct (Lusch et al. in J Endourol 28:261-266, 2014) visualization was 86.5% (95% CI 71.2-96.6%) prior to dissection of Calot's triangle with a 2.5-mg dosage of ICG and 96.5% (95% CI 93.9-98.4%) after dissection. The results were not appreciably different when the dosage was based upon bodyweight. There is moderate quality evidence that the CD is more frequently visualized using ICG than IOC (RR 1.16; 95% CI 1.00-1.35); however, this difference was not statistically significant. This systematic review provides equal results for biliary tract visualization with near-infrared imaging with ICG during LC compared to IOC. Near-infrared imaging with ICG has the potential to replace IOC for biliary mapping. However, methods of near-infrared imaging with ICG vary. Future research is necessary for optimization and standardization of the near-infrared ICG technique.

  18. Evaluation of tumour necrosis during chemotherapy with diffusion-weighted MR imaging: preliminary results in osteosarcomas

    Uhl, Markus; Saueressig, Ulrich; Bley, Thorsten; Langer, Mathias [University Hospital, Department of Radiology, Freiburg (Germany); Koehler, Gabriele [University Hospital, Department of Pathology, Freiburg (Germany); Kontny, Udo [University Hospital, Children' s Hospital, Freiburg (Germany); Niemeyer, Charlotte [University Hospital, Department of Paediatric Oncology, Freiburg (Germany); Reichardt, Wilfried; Ilyasof, Kamil [University Hospital, Department of Medical Physics, Freiburg (Germany)


    During successful chemotherapy of osteosarcomas tumour size does not diminish significantly because the therapy has limited impact on the mineralized matrix of the tumour. Treatment response is considered successful if, histologically, more than 90% of tumour cells show necrosis. To determine if osteosarcomas change their water diffusion during preoperative chemotherapy in relation to the amount of tumour necrosis. Eight patients (age 11-19 years) with histologically proven limb osteosarcoma underwent T1-weighted, fat-suppressed T2-weighted and contrast-enhanced T1-weighted spin-echo imaging together with diffusion-weighted EPI sequences (b = 700) at 1.5 T before and after five cycles of standard chemotherapy. Tumour volume and apparent diffusion coefficient (ADC) maps were calculated before and after chemotherapy. The degree of tumour necrosis after chemotherapy was assessed using the histological Salzer-Kuntschik classification (grades 1-6). During chemotherapy, the ADC values of osteosarcomas changed significantly. The ADC of untreated tumour was 2.1 {+-} 0.4 x 10{sup -3} mm{sup 2}/s (mean {+-} SD) (95% CI 1.6-2.0). The ADC of chemotherapy-treated sarcomas was 2.5 {+-} 0.4 x 10{sup -3} mm{sup 2}/s (95% CI 1.8-2.2). Necrotic areas, which were confirmed by macroscopic examination, showed ADC values up to 2.7 x 10{sup -3} mm{sup 2}/s. Four patients with little viable tumour tissue within the neoplasm (Salzer-Kuntschik grades 1-2) had an increase in ADC of 0.4 up to 0.7 x 10{sup -3} mm{sup 2}/s. Four patients with larger areas of viable tumour (Salzer-Kuntschik grade 4) showed a lesser increase in ADC of 0.0 up to 0.3 x 10{sup -3} mm{sup 2}/s. The differences in ADC values in tumour tissue before and after chemotherapy were highly significant (P = 0.01). During chemotherapy of osteosarcomas, tumour ADC changes are related to the degree of tumour necrosis. (orig.)

  19. Lightning Imaging Sensor (LIS) on the International Space Station (ISS): Launch, Installation, Activation, and First Results

    Blakeslee, R. J.; Christian, H. J., Jr.; Mach, D. M.; Buechler, D. E.; Koshak, W. J.; Walker, T. D.; Bateman, M. G.; Stewart, M. F.; O'Brien, S.; Wilson, T. O.; Pavelitz, S. D.; Coker, C.


    Over the past 20 years, the NASA Marshall Space Flight Center, the University of Alabama in Huntsville, and their partners developed and demonstrated the effectiveness and value of space-based lightning observations as a remote sensing tool for Earth science research and applications, and, in the process, established a robust global lightning climatology. The observations included measurements from the Lightning Imaging Sensor (LIS) on the Tropical Rainfall Measuring Mission (TRMM) and its Optical Transient Detector (OTD) predecessor that acquired global observations of total lightning (i.e., intracloud and cloud-to-ground discharges) spanning a period from May 1995 through April 2015. As an exciting follow-on to these prior missions, a space-qualified LIS built as a flight-spare for TRMM will be delivered to the International Space Station (ISS) for a 2 year or longer mission, flown as a hosted payload on the Department of Defense (DoD) Space Test Program-Houston 5 (STP-H5) mission. The STP-H5 payload containing LIS is scheduled launch from NASA's Kennedy Space Center to the ISS in November 2016, aboard the SpaceX Cargo Resupply Services-10 (SpaceX-10) mission, installed in the unpressurized "trunk" of the Dragon spacecraft. After the Dragon is berth to ISS Node 2, the payload will be removed from the trunk and robotically installed in a nadir-viewing location on the external truss of the ISS. Following installation on the ISS, the LIS Operations Team will work with the STP-H5 and ISS Operations Teams to power-on LIS and begin instrument checkout and commissioning. Following successful activation, LIS orbital operations will commence, managed from the newly established LIS Payload Operations Control Center (POCC) located at the National Space Science Technology Center (NSSTC) in Huntsville, AL. The well-established and robust processing, archival, and distribution infrastructure used for TRMM was easily adapted to the ISS mission, assuring that lightning

  20. Extraction of Urban Trees from Integrated Airborne Based Digital Image and LIDAR Point Cloud Datasets - Initial Results

    Dogon-yaro, M. A.; Kumar, P.; Rahman, A. Abdul; Buyuksalih, G.


    Timely and accurate acquisition of information on the condition and structural changes of urban trees serves as a tool for decision makers to better appreciate urban ecosystems and their numerous values which are critical to building up strategies for sustainable development. The conventional techniques used for extracting tree features include; ground surveying and interpretation of the aerial photography. However, these techniques are associated with some constraint, such as labour intensive field work, a lot of financial requirement, influences by weather condition and topographical covers which can be overcome by means of integrated airborne based LiDAR and very high resolution digital image datasets. This study presented a semi-automated approach for extracting urban trees from integrated airborne based LIDAR and multispectral digital image datasets over Istanbul city of Turkey. The above scheme includes detection and extraction of shadow free vegetation features based on spectral properties of digital images using shadow index and NDVI techniques and automated extraction of 3D information about vegetation features from the integrated processing of shadow free vegetation image and LiDAR point cloud datasets. The ability of the developed algorithms shows a promising result as an automated and cost effective approach to estimating and delineated 3D information of urban trees. The research also proved that integrated datasets is a suitable technology and a viable source of information for city managers to be used in urban trees management.

  1. Rapid, reliable geodetic data analysis for hazard response: Results from the Advanced Rapid Imaging and Analysis (ARIA) project

    Owen, S. E.; Simons, M.; Hua, H.; Yun, S.; Cruz, J.; Webb, F.; Rosen, P. A.; Fielding, E. J.; Moore, A. W.; Polet, J.; Liu, Z.; Agram, P. S.; Lundgren, P.


    ARIA is a joint JPL/Caltech coordinated project to automate InSAR and GPS imaging capabilities for scientific understanding, hazard response, and societal benefit. Geodetic imaging's unique ability to capture surface deformation in high spatial and temporal resolution allows us to resolve the fault geometry and distribution of slip associated with earthquakes in high spatial & temporal detail. In certain cases, it can be complementary to seismic data, providing constraints on location, geometry, or magnitude that is difficult to determine with seismic data alone. In addition, remote sensing with SAR provides change detection and damage assessment capabilities for earthquakes, floods and other disasters that can image even at night or through clouds. We have built an end-to-end prototype geodetic imaging data system that forms the foundation for a hazard response and science analysis capability that integrates InSAR, high-rate GPS, seismology, and modeling to deliver monitoring, science, and situational awareness products. This prototype incorporates state-of-the-art InSAR and GPS analysis algorithms from technologists and scientists. The products have been designed and a feasibility study conducted in collaboration with USGS scientists in the earthquake and volcano science programs. We will present results that show the capabilities of this data system in terms of latency, data processing capacity, quality of automated products, and feasibility of use for analysis of large SAR and GPS data sets and for earthquake response activities.

  2. Cosmological Results from Five Years of 30 GHz CMB Intensity Measurements with the Cosmic Background Imager

    Sievers, J L; Weintraub, L; Achermann, C; Altamirano, P; Bond, J R; Bronfman, L; Bustos, R; Contaldi, C; Dickinson, C; Jones, M E; May, J; Myers, S T; Oyarce, N; Padin, S; Pearson, T J; Pospieszalski, M; Readhead, A C S; Reeves, R; Shepherd, M C; Taylor, A C; Torres, S


    We present final results on the angular power spectrum of total intensity anisotropies in the CMB from the CBI. Our analysis includes all primordial anisotropy data collected between January 2000 and April 2005, and benefits significantly from an improved maximum likelihood analysis pipeline. It also includes results from a 30 GHz foreground survey conducted with the Green Bank Telescope (GBT) which places significant constraints on the possible contamination due to foreground point sources. We improve on previous CBI results by about a factor of two in the damping tail. These data confirm, at ~3-sigma, the existence of an excess of power over intrinsic CMB anisotropy on small angular scales (l > 1800). Using the GBT survey, we find currently known radio source populations are not capable of generating the power; a new population of faint sources with steeply rising spectral indices would be required to explain the excess with sources... We also present a full cosmological parameter analysis of the new CBI po...

  3. Flag brands as factor and results of a country identity and image: Polish experiences

    Anna Maria Nikodemska-Wolowik


    Full Text Available This article discusses the issue of creating regional and country brands by enterprises and of establishing a national brand. The three mentioned flag brand categories have been described in detail and the relations between them have been indicated. The article also makes an attempt at analyzing the factors that form part of the brand identity focusing primarily on the consumer product brands. The identity and image concepts are presented also in a broader perspective as certain attributes that characterize the enterprise itself. The presented considerations refer mainly to Polish companies, but some examples of enterprises from highly developed countries, especially from the European Union, have also been added in order to provide this paper with more practical dimensions. Specific brands offered by national enterprises that may be called country and regional brands have been proposed. Some transformations of the market environment which imply branding activities of the companies have been identified, especially the antiglobalist movement which becomes more and more powerful and its activities directed against big concerns and omnipresent mass brands. Moreover, the consumer ethnocentrism and regional trends opposed to the globalization have been emphasized. Also the important rote of family businesses in developing flag brands has been made evident. The family companies may contribute to maintaining and reinforcing the Polish identity.El presente trabajo se ocupa de los aspectos referentes a la creación de marcas regionales y locales así como del establecimiento de una marca nacional. Las tres categorías de marcas de bandera se han caracterizado detalladamente y se indican las relaciones que existen entre ellas. También se intenta analizar los factores que forman parte de la identidad de marca, con especial atención a las marcas de productos de consumo. Se presentan los conceptos de identidad e imagen desde una perspectiva más amplia como

  4. Assessment of the variations in fat content in normal liver using a fast MR imaging method in comparison with results obtained by spectroscopic imaging.

    Irwan, Roy; Edens, Mireille A; Sijens, Paul E


    A recently published Dixon-based MRI method for quantifying liver fat content using dual-echo breath-hold gradient echo imaging was validated by phantom experiments and compared with results of biopsy in two patients (Radiology 2005;237:1048-1055). We applied this method in ten healthy volunteers and compared the outcomes with the results of MR spectroscopy (MRS), the gold standard in quantifying liver fat content. Novel was the use of spectroscopic imaging yielding the variations in fat content across the liver rather than a single value obtained by single voxel MRS. Compared with the results of MRS, liver fat content according to MRI was too high in nine subjects (range 3.3-10.7% vs. 0.9-7.7%) and correct in one (21.1 vs. 21.3%). Furthermore, in one of the ten subjects the MRI fat content according to the Dixon-based MRI method was incorrect due to a (100-x) versus x percent lipid content mix-up. The second problem was fixed by a minor adjustment of the MRI algorithm. Despite systematic overestimation of liver fat contents by MRI, Spearman's correlation between the adjusted MRI liver fat contents with MRS was high (r = 0.927, P < 0.001). Even after correction of the algorithm, the problem remaining with the Dixon-based MRI method for the assessment of liver fat content,is that, at the lower end range, liver fat content is systematically overestimated by 4%.

  5. IMAGE Project: Results of Laboratory Tests on Tracers for Supercritical Conditions.

    Brandvoll, Øyvind; Opsahl Viig, Sissel; Nardini, Isabella; Muller, Jiri


    The use of tracers is a well-established technique for monitoring dynamic behaviour of water and gas through a reservoir. In geothermal reservoirs special challenges are encountered due to high temperatures and pressures. In this work, tracer candidates for monitoring water at supercritical conditions (temperature > 374°C, pressure ca 218 bar), are tested in laboratory experiments. Testing of tracers at supercritical water conditions requires experimental set-ups which tolerate harsh conditions with respect to high temperature and pressure. In addition stringent HES (health, environment and safety) factors have to be taken into consideration when designing and performing the experiments. The setup constructed in this project consists of a pressure vessel, high pressure pump, instrumentation for pressure and temperature control and instrumentation required for accurate sampling of tracers. In order to achieve accurate results, a special focus has been paid to the development of the tracer sampling technique. Perfluorinated cyclic hydrocarbons (PFCs) have been selected as tracer candidates. This group of compounds is today commonly used as gas tracers in oil reservoirs. According to the literature they are stable at temperatures up to 400°C. To start with, five PFCs have been tested for thermal stability in static experiments at 375°C and 108 bar in the experimental setup described above. The tracer candidates will be further tested for several months at the relevant conditions. Preliminary results indicate that some of the PFC compounds show stability after three months. However, in order to arrive at conclusive results, the experiments have to be repeated over a longer period and paying special attention to more accurate sampling procedures.

  6. Verification of nonlinear dynamic structural test results by combined image processing and acoustic analysis

    Tene, Yair; Tene, Noam; Tene, G.


    An interactive data fusion methodology of video, audio, and nonlinear structural dynamic analysis for potential application in forensic engineering is presented. The methodology was developed and successfully demonstrated in the analysis of heavy transportable bridge collapse during preparation for testing. Multiple bridge elements failures were identified after the collapse, including fracture, cracks and rupture of high performance structural materials. Videotape recording by hand held camcorder was the only source of information about the collapse sequence. The interactive data fusion methodology resulted in extracting relevant information form the videotape and from dynamic nonlinear structural analysis, leading to full account of the sequence of events during the bridge collapse.

  7. Estimation of global daily irradiation in complex topography zones using digital elevation models and meteosat images: Comparison of the results

    Martinez-Durban, M. [Dpto. de Lenguajes y Computacion, Universidad de Almeria, 04120 Almeria (Spain); Zarzalejo, L.F.; Polo, J. [Dpto. de Energia, CIEMAT, 28040 Madrid (Spain); Bosch, J.L.; Rosiek, S.; Batlles, F.J. [Dpto. Fisica Aplicada, Universidad de Almeria, 04120 Almeria (Spain)


    The knowledge of the solar irradiation in a certain place is fundamental for the suitable location of solar systems, both thermal and photovoltaic. On the local scale, the topography is the most important modulating factor of the solar irradiation on the surface. In this work the global daily irradiation is estimated concerning various sky conditions, in zones of complex topography. In order to estimate the global daily irradiation we use a methodology based on a Digital Terrain Model (DTM), on one hand making use of pyranometer measurements and on the other hand utilizing satellite images. We underline that DTM application employing pyranometer measurements produces better results than estimation using satellite images, though accuracy of the same order is obtained in both cases for Root Mean Square Error (RMSE) and Mean Bias Error (MBE). (author)

  8. Results of a low power ice protection system test and a new method of imaging data analysis

    Shin, Jaiwon; Bond, Thomas H.; Mesander, Geert A.


    Tests were conducted on a BF Goodrich De-Icing System's Pneumatic Impulse Ice Protection (PIIP) system in the NASA Lewis Icing Research Tunnel (IRT). Characterization studies were done on shed ice particle size by changing the input pressure and cycling time of the PIIP de-icer. The shed ice particle size was quantified using a newly developed image software package. The tests were conducted on a 1.83 m (6 ft) span, 0.53 m (221 in) chord NACA 0012 airfoil operated at a 4 degree angle of attack. The IRT test conditions were a -6.7 C (20 F) glaze ice, and a -20 C (-4 F) rime ice. The ice shedding events were recorded with a high speed video system. A detailed description of the image processing package and the results generated from this analytical tool are presented.

  9. Manual khalifa therapy in patients with completely ruptured anterior cruciate ligament in the knee: First preliminary results from thermal imaging

    Gerhard Litscher


    Full Text Available Background: This preliminary publication describes acute temperature effects after manual Khalifa therapy. Aims : The goal of this study was to describe temperature distribution and the effects on surface temperature of the knees and feet in patients with completely ruptured anterior cruciate ligament before and immediately after the manual therapy. Materials and Methods: Ten male patients were investigated with thermal imaging. An infrared camera operating at a wavelength range of 7.5-13 μm was used. Temperature was analyzed at three locations on both knees and in addition on both feet. Results: The study revealed that baseline temperature of the injured knee differed from that of the untreated control knee. After the therapy on the injured knee, the surface temperature was significantly increased on both knees (injured and control. There were no significant changes in the temperature of the feet. Conclusions: Further studies using continuous thermal image recording may help to explain the details concerning the temperature distribution.

  10. Comparative analysis of microscopic images and XRF and EDS results of bricks from arheological sites Mediana and Naisus

    Kalamković Snežana


    Full Text Available This paper describes the archaeological sites Mediana and Naisus during Late Antiquity. Microscopic images of bricks, and the results and analysis of XRF bricks from these archaeological sites are shown. Based on the results, it can be concluded that a similar brick exterior, and approximately the same chemical composition. One reason is, most likely, a similar chemical composition of the soil, because the archaeological sites are geographically close to each other. Another reason could be the same way bricks were producted, and that the same fuel was used in the kilns.

  11. An infinity of phase transitions as a function of temperature: exact results for a model with fixed-point imaging

    Hefner, B. Todd; Walker, James S.


    Position-space renormalization-group methods are used to derive exact results for an Ising model on a fractal lattice. The model incorporates both nearest-neighbor and long-range interactions. The long-range interactions, which span all length scales on the lattice, can be thought of as resulting from fractal periodic boundary conditions. We present exact phase diagrams and specific heats in terms of these two interactions, and show that a “hall of mirrors” fixed-point imaging mechanism leads to an infinite number of phase transitions.

  12. Images of Poverty in Contemporary Realistic Fiction for Youth: Preliminary Results of a Content Analysis Using a Social Psychological Conceptual Framework.

    Fitzgibbons, Shirley A.; Tilley, Carol L.

    This preliminary study of 20 contemporary realistic fiction books for youth, in middle school and above, analyzed images of poverty using a framework adapted from the work of Robert Leahy. Findings are related to demographics, images of poverty and emerging themes. Results indicate that, as a whole, the sample of books rely on concrete images of…

  13. Development and implementation of algorithms for automatic and robust measurement of the 2D:4D digit ratio using image data

    Koch Robert


    Full Text Available Early in the 20th century it could be observed that the finger lengths of second (2D and fourth digit (4D represents a sexually dimorphic feature, whereby in general the second digit is longer than the fourth digit for men and vice versa for women. In the early 1980s first studies could show a correlation between the 2D:4D ratio and the concentration of androgens one is exposed to during a short window within the prenatal development phase. Therefore, the 2D:4D digit ratio can serve as an additional marker for certain physiological and psychological traits like fertility, assertiveness, aggressiveness and alcohol addiction. Manual measurements are the established method to retrieve the finger lengths e.g. by using a ruler on printed scans of hands. For higher reliability these extremely time-consuming procedures have to be done multiple times. In this contribution two automated procedures are proposed to reduce the time for measurements whilst maintaining the accuracy. A deviation of maximal 2% from the manual measurement could be achieved for more than 75% of the 22 participants.

  14. Preliminary Results of Three-Dimensional Magnetotelluric Imaging at the Vicinity of Nigde Massif

    Bülent Tank, Sabri; Ozaydin, Sinan; Uslular, Göksu; Delph, Jonathan; Abgarmi, Bizhan; Karas, Mustafa; Sandvol, Eric


    Magnetotelluric (MT) data were collected to examine the electrical resistivity structure of a metamorphic core complex known as the Niǧde Massif and a northeast - southwest aligned fault zone (Central Anatolian Fault Zone, CAFZ) bounding this massif on the east in Central Anatolia. The Nigde Massif is a crystalline dome close to Inner-Tauride Suture at the southern part of Central Anatolian Crystalline Complex. The sinistral CAFZ (in the south it is called Ecemis fault) is a 700 km long, 2 to 80 km wide zone with an offset of 60 to 80 km. Three-dimensional numerical modeling routines based on data-space modeling (WSINV3DMT and ModEM) were used to invert the MT data collected at forty-seven high quality soundings. The resulting models suggest that (i) there is a large and circular high resistivity, dome-like anomaly that coincides with the Niǧde Massif. This block includes intrusive (Üçkapılı-like) granitoids at the heart of the massif extending to northeast. (ii) Beneath the massif there is a deeper (> 25 km) and relatively higher conductive zone that may have developed as a result of partial melting and is responsible for earlier defined lateral underflow to the northeast. (iii) Clear evidence for low angle normal sense detachment faults bounding the massif were found on several cross sections. (iv) Seismically active Ecemis fault appears as a low to high conductivity interface mostly hidden beneath non-conformable Eocene cover (iv) Ulukısla basin sediments appear as a highly conductive layer. (v) Ophiolitic mélange on the southeast side of Ecemis fault dominate the area with a high conductivity layer.

  15. A Comparison of the Theoretical Relationship between HDL Size and the Ratio of HDL Cholesterol to Apolipoprotein A-I with Experimental Results from the Women’s Health Study

    Mazer, Norman A.; Giulianini, Franco; Paynter, Nina P.; Jordan, Paul; Mora, Samia


    Background HDL size and composition vary among individuals and may be associated with cardiovascular disease and diabetes. We investigated the theoretical relationship between HDL size and composition using an updated version of the spherical model of lipoprotein structure proposed by Shen et al. and compared its predictions with experimental data from the Women’s Health Study (WHS). Methods The Shen model was updated to predict the relationship between HDL diameter and the ratio of HDL-cholesterol (HDL-C) to apolipoprotein A-I (ApoA-I) plasma concentrations, i.e., the HDL-C/ApoA-I ratio. In WHS (n=26,772), NMR spectroscopy was used to measure the average HDL diameter (davg,NMR) and particle concentration (HDL-P); HDL-C and ApoA-I (mg/dL) were measured by standardized assays. Results The updated Shen model predicts a quasi-linear increase of HDL diameter with the HDL-C/ApoA-I ratio, consistent with the measured davg,NMR values from WHS, which ranged between 8.0 and 10.8 nm and correlated positively with the HDL-C/ApoA-I ratio (r=0.608, pHDL-C/ApoA-I. The validity of this equation for estimating HDL size was assessed with data from CETP deficiency and pharmacologic inhibition. We also illustrate how HDL-P can be estimated from the HDL size and ApoA-I level. Conclusions This study provides a large-scale experimental examination of the updated Shen model, offers new insights into HDL structure, composition and remodeling, and suggests that the HDL-C/ApoA-I ratio could be a readily available biomarker for estimating HDL size and HDL-P. PMID:23426429

  16. Identification and estimation of socioeconomic impacts resulting from perceived risks and changing images; An annotated bibliography

    Nieves, L.A.; Wernette, D.R.; Hemphill, R.C.; Mohiudden, S.; Corso, J.


    In 1982, the US Congress passed the Nuclear Waste Policy Act to initiate the process of choosing a location to permanently store high-level nuclear waste from the designated Yucca Mountain, Nevada, as the only location to be studied as a candidate site for such a repository. The original acts and its amendments had established the grant mechanism by which the state of Nevada could finance an investigation of the potential socioeconomic impacts that could result from the installation and operation of this facility. Over the past three years, the Office of Civilian Radioactive Waste Management (OCRWM or RW) in the US Department of Energy (DOE) has approved grant requests by Nevada to perform this investigation. This report is intended to update and enhance a literature review conducted by the Human Affairs Research Center (HARC) for the Basalt Waste Isolation Project that dealt with the psychological and sociological processes underlying risk perception. It provides addition information on the HARC work, covers a subsequent step in the impact-estimation process, and translates risk perception into decisions and behaviors with economic consequences. It also covers recently developed techniques for assessing the nature and magnitude of impacts caused by environmental changes focusing on those impacts caused by changes in perceived risks.

  17. Uterine artery embolization (UAE) for diffuse leiomyomatosis of the uterus: Clinical and imaging results

    Koh, Jieun [Department of Radiology, Research Institute of Radiological Science, Yonsei University College of Medicine, 50 Yonsei-ro, Shinchon-dong, Seodaemun-gu, Seoul 120-752 (Korea, Republic of); Kim, Man Deuk, E-mail: [Department of Radiology, Research Institute of Radiological Science, Yonsei University College of Medicine, 50 Yonsei-ro, Shinchon-dong, Seodaemun-gu, Seoul 120-752 (Korea, Republic of); Jung, Dae Chul; Lee, Myungsu; Lee, Mu Sook; Won, Jong Yun; Lee, Do Yun; Park, Sung Il; Lee, Kwang Hun [Department of Radiology, Research Institute of Radiological Science, Yonsei University College of Medicine, 50 Yonsei-ro, Shinchon-dong, Seodaemun-gu, Seoul 120-752 (Korea, Republic of)


    Purpose: The aim of the current study was to evaluate the efficacy of uterine artery embolization (UAE) in the management of diffuse uterine leiomyomatosis with mid-term follow-up. Materials and methods: All patients who underwent UAE between 2008 and 2010 for symptomatic fibroids were analyzed. Among 360 cases, a total of 7 patients with diffuse uterine leiomyomatosis diagnosed based on MRI were included in this retrospective study. Patient ages ranged from 29 to 38 (mean 32.7) years. The median follow-up period was 16 (range; 6–31) months. The embolic agent was non-spherical polyvinyl alcohol particles. All patients underwent follow-up MRI at 3 months after UAE. Uterine volumes were calculated using MRI. Menorrhagia symptom changes were assessed at mid-term follow-up. Results: There were no technical failures to catheterize the uterine artery and no adverse events requiring therapy after UAE. Contrast-enhanced MRI showed complete necrosis of the leiomyomatous nodules in 5 patients (71%) 3 months after embolization. Two patients (28%) showed mostly leiomyomatous nodules that were necrotized, some of which were still viable. All 7 patients with menorrhagia had improvement of symptoms at the mid-term follow-up. The initial mean uterine volume was 601.30 ± 533.92 cm{sup 3} and was decreased to a mean of 278.81 ± 202.70 cm{sup 3} at 3 months follow-up, for a mean uterus volume reduction rate of 50.1% (p < 0.05). One patient became pregnant 5 months after UAE treatment. Conclusion: UAE was a highly effective treatment for diffuse uterine leiomyomatosis with mid-term durability and may be a valuable alternative to hysterectomy.

  18. Spoc-experiment: Seismic Imaging and Bathymetry of The Central Chile Margin - First Results

    Ladage, S.; Reichert, C.; Schreckenberger, B.; Block, M.; Bönnemann, C.; Canuta, J.; Damaske, D.; Diaz-Naveas, J.; Gaedicke, C.; Krawczyk, C.; Kus, J.; Urbina, O.; Sepulveda, J.

    During the RV SONNE cruise 161 Leg 1 to 5 (October 2001 to January 2002) Sub- duction Processes Off Chile (SPOC) have been investigated using a multi-disciplinary geoscientific approach. Here we report first results of multi channel seismic (MCS) experiments and high-resolution swath bathymetry data from Leg 3, south of Val- paraiso. 24 MCS profiles with a total length of 3670 km were run between 36 S to 4020' S, providing a detailed view of the structures related to the subduction of the Nazca Plate under the Chile Margin. The oceanic crust of the Nazca Plate shows at least three sets of structural trends associated with the Mocha and Valdivia Fractures Zones, the spreading lineations and subduction related horst and graben structures. In the study area the trench is filled with well stratified turbidites up to 2 seconds TWT thick. Along the trench axis a turbidite channel exceeding 80 m relief exists. Several large deep sea fan complexes are developed at the slope toe. Their distributary canyons cut deep into the slope and shelf and can be traced back to major river mouths. The deformation front is coincident with the slope toe; compressional structures of the trench fill are uncommon. The deformation front is curved and offset along strike, caused presumably by collision and indentation of structures of the Nazca Plate. The most remarkable features of the MCS - profiles, yet, are the only very rudimentary developed modern accretionary prism as well as the high variability of the lower slope angles. Lower slope angles locally exceed 10. The continental crust extends seawards to the middle slope and acts as a backstop. Several profiles reveal landward dipping reflectors above the downgoing slab, possibly depicting a subduction channel beneath the slope. Thus, the geometry of the subduction units U a young thick trench fill, only rudimental frontal accretion and a subduction channel U argues for subduction of the bulk of the sediments.

  19. New and Evolving Seismic Images of the Central Andes and Subducting Nazca Slab: 20 Years of Portable Seismology Results

    Beck, S. L.


    Beno Gutenberg first identified a seismic low velocity zone in the upper mantle that we now refer to as the asthenosphere that is still the focus of many studies in active tectonic regions. The upper-most mantle is very heterogeneous and occupies the depth range where much of the tectonic action occurs especially in subduction zones and convergent margins. The central South American convergent margin is the result of the subduction of the Nazca Plate beneath the South American Plate and includes the Andes, one of the largest actively growing mountain ranges on Earth. The South American subduction zone has two regions of "flat" subduction in Peru and central Chile and Argentina separated by a segment of "normal" subduction and an active magmatic arc. The central Andean plateau has an average elevation of 3-4 km and some of the thickest crust on Earth with deformation reaching ~800 km inland. This active margin is characterized by along-strike variations in magmatism, upper crustal shortening, crustal thickness, and slab geometry that make it an ideal region to study the relationship between the subducting slab, the mantle wedge, and the overriding plate. After 20 years of portable seismic deployments in the Central Andes seismologists have generated unprecedented seismic images spanning ~3000 km of the Andean lithosphere, the subducting Nazca slab, and the surrounding mantle. Seismic travel-time, ambient noise and earthquake surface-wave tomography, receiver function imaging, and joint receiver function - surface wave dispersion inversions have produced along strike images of the Central Andes from the surface to a depth of ~700 km. These new images were made possible by PI-driven portable broadband seismic deployments and data sharing by many international groups. I will highlight images of along-strike variations in crustal properties and thickness, mantle lithospheric structure, and slab geometry. These seismic images allow us to more completely evaluate the role

  20. The South India Precambrian crust and shallow lithospheric mantle: Initial results from the India Deep Earth Imaging Experiment (INDEX)

    S S Rai; Kajaljyoti Borah; Ritima Das; Sandeep Gupta; Shalivahan Srivastava; K S Prakasam; K Sivaram; Sudesh Kumar; Rishikesh Meena


    We present here the most comprehensive study of the thickness and composition (/ ratio) of the South India Precambrian crust and the nature of shallower mantle inferred from analysis of teleseismic receiver functions from 70 broad-band seismic stations operated as a part of the India Deep Earth Imaging Experiment (INDEX). South India could be broadly divided into regions with thin crust (32–38 km) and thick crust (38–54 km). Thin crust domains include the East Dharwar Craton (EDC), Cuddapah basin and Madurai/Kerala Khondalite Block. The thicker crust domain includes the Western Dharwar Craton (WDC) and northern part of Southern Granulite Terrain. The WDC shows progressive increase in thickness from 38 km in north to 46–54 km in south, compared to an almost flat Moho beneath the EDC. Compositionally, most of the crustal domains are felsic to intermediate (/ ∼ 1.69–1.75) except the mid Archean block in the southern WDC where it is mafic (/ < 1.81). Considering erosion depth in the WDC, we argue for Himalaya like ∼70 km thick crust beneath it during the Archean. Variation in crustal thickness does not have a first-order influence on regional topography in South India and suggests significant role for the crustal composition. We also present evidence of mid-lithospheric low velocity at ∼85–100 km beneath South India.

  1. Multiparametric MRI for prostate cancer detection: Preliminary results on quantitative analysis of dynamic contrast enhanced imaging, diffusion-weighted imaging and spectroscopy imaging.

    Fusco, Roberta; Sansone, Mario; Petrillo, Mario; Setola, Sergio Venanzio; Granata, Vincenza; Botti, Gerardo; Perdonà, Sisto; Borzillo, Valentina; Muto, Paolo; Petrillo, Antonella


    Early promising data suggest that combined use of both morphological and functional MRI (multi-parametric MR, mpMRI) including MRSI, DWI and DCE may be of additional value for prostate cancer localization and its local staging. The objective of this paper is to evaluate the diagnostic performance of mpMRI in the detection of prostate cancer. Thirty-one consecutive male patients were screened to be enrolled in a single center prospective observational study. All eligible patients underwent multi-parametric MRI and TRUS (Trans Rectal Ultra Sound) guided prostate biopsies. A register, approved by the Institutional Ethics Committee, included patients enrolled in this study. All patients who decided to undergo the MRI examination signed an explicit informed consensus. MRI data were aligned on a common spatial grid and several functional parameters (perfusion, diffusion and metabolic parameters) were computed. Statistical analysis was conducted in order to compare mpMRI with biopsy-based analysis. Statistically significant differences between median values in high Gleason score (≥5) and low Gleason score (<5) to Wilcox on rank sum test were obtained for MRSI parameters and for plasma fraction (Tofts model) of DCE-MRI. The area under curve obtained with ROC analysis showed that the best-performing single-parameter was vp (plasma fraction of Tofts model), while the best parameters combination to discriminate the area with high Gleason score were (Cho+Cr)/Cit and Cho+Cr. Linear Discrimination Analysis showed that the best results were obtained considering the linear combination of all MRSI parameters and the linear combination of all features (perfusion, diffusion and metabolic parameters). In conclusion, our findings showed that by combining morphological MRI, DWI, DCE-MRI and MRSI, an increase in sensitivity and specificity correlated to biopsy Gleason grade could be obtained. Furthermore, morphological and functional MRI could have a diagnostic role in patients with

  2. Ultrasound-Guided Optical Tomographic Imaging of Malignant and Benign Breast Lesions: Initial Clinical Results of 19 Cases

    Quing Zhu


    Full Text Available The diagnosis of solid benign and malignant tumors presents a unique challenge to all noninvasive imaging modalities. Ultrasound is used in conjunction with mammography to differentiate simple cysts from solid lesions. However, the overlapping appearances of benign and malignant lesions make ultrasound less useful in differentiating solid lesions, resulting in a large number of benign biopsies. Optical tomography using near-infrared diffused light has great potential for imaging functional parameters of 1 tumor hemoglobin concentration, 2 oxygen saturation, 3 metabolism, as well as other tumor distinguishing characteristics. These parameters can differentiate benign from malignant lesions. However, optical tomography, when used alone, suffers from low spatial resolution and target localization uncertainty due to intensive light scattering. Our aim is to combine diffused light imaging with ultrasound in a novel way for the detection and diagnosis of solid lesions. Initial findings of two earlystage invasive carcinomas, one combined fibroadenoma and fibrocystic change with scattered foci of lobular neoplasia/lobular carcinoma in situ, 16 benign lesions are reported in this paper. The invasive cancer cases reveal about two-fold greater total hemoglobin concentration (mean 119 μmol than benign cases (mean 67 μmol, suggest that the discrimination of benign and malignant breast lesions might be enhanced by this type of achievable optical quantification with ultrasound localization. Furthermore, the small invasive cancers are well localized and have wavelength-dependent appearance in optical absorption maps, whereas the benign lesions appear diffused and relatively wavelength-independent.

  3. Can we use digital life-log images to investigate active and sedentary travel behaviour? Results from a pilot study

    Hodges Steve


    Full Text Available Abstract Background Active travel such as walking and cycling has potential to increase physical activity levels in sedentary individuals. Motorised car travel is a sedentary behaviour that contributes to carbon emissions. There have been recent calls for technology that will improve our ability to measure these travel behaviours, and in particular evaluate modes and volumes of active versus sedentary travel. The purpose of this pilot study is to investigate the potential efficacy of a new electronic measurement device, a wearable digital camera called SenseCam, in travel research. Methods Participants (n = 20 were required to wear the SenseCam device for one full day of travel. The device automatically records approximately 3,600 time-stamped, first-person point-of-view images per day, without any action required by the wearer. Participants also completed a self-report travel diary over the same period for comparison, and were interviewed afterwards to assess user burden and experience. Results There were a total of 105 confirmed journeys in this pilot. The new SenseCam device recorded more journeys than the travel diary (99 vs. 94. Although the two measures demonstrated an acceptable correlation for journey duration (r = 0.92, p Conclusions Direct observation of travel behaviour from time-stamped images shows considerable potential in the field of travel research. Journey duration derived from direct observation of travel behaviour from time-stamped images appears to suggest over-reporting of self-reported journey duration.

  4. The rectilinear Steiner ratio

    PO de Wet


    Full Text Available The rectilinear Steiner ratio was shown to be 3/2 by Hwang [Hwang FK, 1976, On Steiner minimal trees with rectilinear distance, SIAM Journal on Applied Mathematics, 30, pp. 104– 114.]. We use continuity and introduce restricted point sets to obtain an alternative, short and self-contained proof of this result.

  5. Potential support ratios

    Kjærgaard, Søren; Canudas-Romo, Vladimir


    , the prospective potential support ratio usually focuses on the current mortality schedule, or period life expectancy. Instead, in this paper we look at the actual mortality experienced by cohorts in a population, using cohort life tables. We analyse differences between the two perspectives using mortality models......, historical data, and forecasted data. Cohort life expectancy takes future mortality improvements into account, unlike period life expectancy, leading to a higher prospective potential support ratio. Our results indicate that using cohort instead of period life expectancy returns around 0.5 extra younger...

  6. Ratios of Normal Variables

    George Marsaglia


    Full Text Available This article extends and amplifies on results from a paper of over forty years ago. It provides software for evaluating the density and distribution functions of the ratio z/w for any two jointly normal variates z,w, and provides details on methods for transforming a general ratio z/w into a standard form, (a+x/(b+y , with x and y independent standard normal and a, b non-negative constants. It discusses handling general ratios when, in theory, none of the moments exist yet practical considerations suggest there should be approximations whose adequacy can be verified by means of the included software. These approximations show that many of the ratios of normal variates encountered in practice can themselves be taken as normally distributed. A practical rule is developed: If a < 2.256 and 4 < b then the ratio (a+x/(b+y is itself approximately normally distributed with mean μ = a/(1.01b − .2713 and variance 2 = (a2 + 1/(b2 + .108b − 3.795 − μ2.

  7. Ratios of Normal Variables

    George Marsaglia


    Full Text Available This article extends and amplifies on results from a paper of over forty years ago. It provides software for evaluating the density and distribution functions of the ratio z/w for any two jointly normal variates z,w, and provides details on methods for transforming a general ratio z/w into a standard form, (a+x/(b+y , with x and y independent standard normal and a, b non-negative constants. It discusses handling general ratios when, in theory, none of the moments exist yet practical considerations suggest there should be approximations whose adequacy can be verified by means of the included software. These approximations show that many of the ratios of normal variates encountered in practice can themselves be taken as normally distributed. A practical rule is developed: If a < 2.256 and 4 < b then the ratio (a+x/(b+y is itself approximately normally distributed with mean μ = a/(1.01b - .2713 and variance σ2 = (a2 + 1/(b2 + .108b - 3.795 μ2.

  8. Assessment of the variations in fat content in normal liver using a fast MR imaging method in comparison with results obtained by spectroscopic imaging

    Irwan, Roy [University Medical Center Groningen, Radiology, Groningen (Netherlands); Toshiba Medical Systems Europe, Zoetermeer (Netherlands); Edens, Mireille A. [University of Groningen, Epidemiology, Groningen (Netherlands); Sijens, Paul E. [University Medical Center Groningen, Radiology, Groningen (Netherlands)


    A recently published Dixon-based MRI method for quantifying liver fat content using dual-echo breath-hold gradient echo imaging was validated by phantom experiments and compared with results of biopsy in two patients (Radiology 2005;237:1048-1055). We applied this method in ten healthy volunteers and compared the outcomes with the results of MR spectroscopy (MRS), the gold standard in quantifying liver fat content. Novel was the use of spectroscopic imaging yielding the variations in fat content across the liver rather than a single value obtained by single voxel MRS. Compared with the results of MRS, liver fat content according to MRI was too high in nine subjects (range 3.3-10.7% vs. 0.9-7.7%) and correct in one (21.1 vs. 21.3%). Furthermore, in one of the ten subjects the MRI fat content according to the Dixon-based MRI method was incorrect due to a (100-x) versus x percent lipid content mix-up. The second problem was fixed by a minor adjustment of the MRI algorithm. Despite systematic overestimation of liver fat contents by MRI, Spearman's correlation between the adjusted MRI liver fat contents with MRS was high (r = 0.927, P < 0.001). Even after correction of the algorithm, the problem remaining with the Dixon-based MRI method for the assessment of liver fat content,is that, at the lower end range, liver fat content is systematically overestimated by 4%. (orig.)

  9. Validation of first chemistry mode retrieval results from new limb-imaging FTS GLORIA with correlative MIPAS-STR observations

    Woiwode, W.; Suminska-Ebersoldt, O.; Oelhaf, H.; Höpfner, M.; Belyaev, G. V.; Ebersoldt, A.; Friedl-Vallon, F.; Grooß, J.-U.; Gulde, T.; Kaufmann, M.; Kleinert, A.; Krämer, M.; Kretschmer, E.; Kulessa, T.; Maucher, G.; Neubert, T.; Piesch, C.; Preusse, P.; Riese, M.; Rongen, H.; Sartorius, C.; Schardt, G.; Schönfeld, A.; Schuettemeyer, D.; Sha, M. K.; Stroh, F.; Ungermann, J.; Volk, C. M.; Orphal, J.


    We report first chemistry mode retrieval results from the new airborne limb-imaging infrared FTS (Fourier transform spectrometer) GLORIA and comparisons with observations by the conventional airborne limb-scanning infrared FTS MIPAS-STR. For GLORIA, the flights aboard the high-altitude research aircraft M55 Geophysica during the ESSenCe campaign (ESa Sounder Campaign 2011) were the very first in field deployment after several years of development. The simultaneous observations of GLORIA and MIPAS-STR during the flight on 16 December 2011 inside the polar vortex and under the conditions of optically partially transparent polar stratospheric clouds (PSCs) provided us the unique opportunity to compare the observations by two different infrared FTS generations directly. The retrieval results of temperature, HNO3, O3, H2O, CFC-11 and CFC-12 show reasonable agreement of GLORIA with MIPAS-STR and collocated in-situ observations. For the horizontally binned hyperspectral limb-images, the GLORIA sampling outnumbered the horizontal cross-track sampling of MIPAS-STR by up to one order of magnitude. Depending on the target parameter, typical vertical resolutions of 0.5 to 2.0 km were obtained for GLORIA and are typically by factors of 2 to 4 better compared to MIPAS-STR. While the improvement of the performance, characterisation and data processing of GLORIA are subject of ongoing work, the presented first results already demonstrate the considerable gain in sampling and vertical resolution achieved with GLORIA.

  10. Radiofrequency ablation of liver VX2 tumor: experimental results with MR diffusion-weighted imaging at 3.0T.

    Yubao Liu

    Full Text Available To evaluate the value of DWI in detecting the lesions of pre- and post-radiofrequency ablation (RFA of the rabbit liver VX2 tumors.Twenty-two New Zealand White rabbits were tested. The protocol was approved by the Committee on the Ethics of Animal Experiments. Twenty separate tumor fragments were implanted into the livers of 20 rabbits, the liver was exposed by performing midline laparotomy. 3.0T MR DWI (b = 0, 200, 400, 600, 800,1000 s/mm2 were performed 14-21 days after tumor implantation (mean, 17 days in the 18 tumor-bearing animals. Then RFA was performed in the 18 tumor-bearing animals and in the two healthy animals. 3.0T MR DWI was performed 7-10 days after RFA (mean, 8 days. Pathology exam was performed immediately after the completion of post- RFA MR imaging. Analyzing the features of MRI and ADC values in the pre- and post- RFA lesions of the VX2 tumors, and histopathologic results were compared with imaging findings.The difference of ADC value between viable tumor and normal liver parenchyma was significant (P<.001. After RFA, when b = 200, 400, 600, 800, 1000 s/mm2, the differences of ADC values of viable tumor, granulation tissue, necrosis, normal liver parenchyma were significant (P<.001. At the time the animals were sacrificed after RFA and MR imaging, histopathologic results of local viable tumors were found in 9 (50% of the 18 treated tumors. Macroscopic viable tumors were found at the RFA sites in 3 (17%, all 3 macroscopic viable tumors were visualized at the periphery of the RFA areas.3.0T MR DWI can be used to follow up the progress of the RFA lesion, it is useful in detecting different tissues after RFA, and it is valuable in the further clinical research.

  11. Low SNR image denoising via sparse and redundant representations over K-SVD algorithm and residual ratio iteration termination%基于K-SVD和残差比的低信噪比图像稀疏表示去噪算法

    张晓阳; 柴毅; 李华锋


    针对低信噪比图像去噪问题,提出了一种基于K-SVD(Singular Value Decomposition)和残差比(Residual Ratio Iteration Termination)的正交匹配追踪(Orthogonal Matching Pursuit,OMP)图像稀疏分解去噪算法.该算法利用K-SVD算法将离散余弦变换(Discrete cosine transform,DCT)框架产生的冗余字典训练成能够有效反映图像结构特征的超完备字典,以实现图像的有效表示.然后以残差比作为OMP算法迭代的终止条件来实现图像的去噪.实验表明,该算法相对于传统基于Symlets小波图像去噪、基于Contourlet变换的图像去噪,以及基于DCT冗余字典的稀疏表示图像去噪,能够更加有效地滤除低信噪比图像中的高斯白噪声,保留原图像的有用信息.%For the low SNR( Signal to Noise Ratio) images denoising, a new algorithm is proposed based on K-SVD and residual ratio iteration termination. Firstly, an initial redundant dictionary is produced under the DCT framework and the dictionary is trained by K-SVD algorithm through the noisy image. A new dictionary that reflects the structure of the image effectively is produced. Then, the residual ratio is used as the iteration termination of OMP algorithm to remove the zero-mean white and homogeneous Gaussian additive noise from a given image. Different kinds of images with different noise levels are used to test the algorithm. The results show that the algorithm has strong robustness and performs better than the image denoising algorithm using Symlets wavelet, Contourlet and sparse representation based on DCT redundant dictionary.

  12. μSPECT: image evaluation using collimator type pinhole. Preliminary results; μSPECT: avaliacao da imagem utilizando colimador tipo pinhole: resultados preliminares

    Miady, Leandro Sunao [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Sao Jose do Rio Preto, SP (Brazil); Squair, Peterson Lima [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil); Pozzo, Lorena, E-mail: [Universidade de Sao Paulo (USP), SP (Brazil)


    At scintigraphy, the method of obtaining tomographic image is called SPECT (single photon emission computed tomography), as well as the equipment able to acquire such tomographic images involving small animals can be called μSPECT. Although the equipment is directed to the acquisition of three-dimensional images, a need exists in certain studies to obtain two-dimensional images. This study aims to verify and analyze the two-dimensional image magnification factor for later application to the study of {sup 131}I dosimetry in mice. The experimental results allowed to analyze and compare the magnification factors for each parameter used for future experiments. (author)

  13. Percutaneous imaging-guided treatment of hydatid liver cysts: Do long-term results make it a first choice?

    Kabaalioglu, Adnan [Department of Radiology, Akdeniz University Hospital, Antalya (Turkey)]. E-mail:; Ceken, Kagan [Department of Radiology, Akdeniz University Hospital, Antalya (Turkey); Alimoglu, Emel [Department of Radiology, Akdeniz University Hospital, Antalya (Turkey); Apaydin, Ali [Department of Radiology, Akdeniz University Hospital, Antalya (Turkey)


    Aim: To evaluate the long-term results of percutaneous imaging-guided treatment of hydatid liver cysts. Materials and methods: Sixty patients with 77 hydatid liver cysts underwent percutaneous treatment with ultrasonography (US) or computed tomography (CT) guidance. Absolute alcohol and hypertonic saline were used for sclerosing the cysts after aspiration. Prophylactic albendazole treatment was given before and after the procedures. Follow-up US and CT were obtained periodically, and changes in cyst morphology were recorded. Minimum follow-up period for the patients included in this study was 12 months. Serological correlation was also available for a group of patients. The outcome of the procedures were categorized into five groups based on morphological changes observed by imaging. Results: Procedures were regarded as successful in 80% and unsuccessful in 20% of patients. Failures most often occurred with type III cysts; less than half (39%) of the total type III cysts had a successful outcome. On the other hand, all type I cysts ended up with cure. Anaphylaxis, pneumotorax and severe pain interrupting the procedures were also among the reasons of failure. Conclusion: Percutaneous aspiration, injection and reaspiration (PAIR) of types I and II hydatid liver cysts is effective and safe in the long-term. Surgery should no longer be regarded as the first choice treatment in all hydatid liver cysts but should be reserved for type III and certain active type IV cysts.

  14. A pilot muon radiography to image the shallow conduit of the Stromboli volcano: results and future prospects

    Miyamoto, Seigo; Tioukov, Valeri; Sirignano, Chiara; Bozza, Cristiano; Morishima, Kunihiro


    The test result of imaging the shallow part of the Stromboli crater zone by using cosmic-ray muons in 2012 and possible performance of the future muon observation will be presented. It is well known that the behavior of volcanic eruptions strongly depends on the shape of the conduit. Stromboli is one of the most known and studied active volcanoes in the world, nevertheless the details of its internal structure are not well defined yet. Geophysical exploration method which use high energy cosmic-ray muons and makes the density image of the object like X-ray radiography for the human body is called "muon radiography " or "muography". A pilot muography was done for the shallow part of Stromboli in 2012. We succeeded to clarify that there is a less density part at the North-East cone in the crater zone. It is considered that the stack of volcanic ashes. On the other hand, we also confirmed that the contamination of the physical background particles and they makes the noisy density image especially about 50 meter below from the top of the crater. In another observation, Nishiyama et al (2014) revealed the contents of background particles and the way to remove them were presented. They showed that the main contents of the background particles is low kinetic energy charged particles and also showed that it is possible to remove them by using multi-layerd muon film detector. We can plan the future muography observation to see the deeper part of the conduit( at least until 100 meter from the top of crater) by their backgroundless method. Therefore we estimated possible performance of the future observation by multi-layer muon films. The result suggests that we might get the image of shallow conduit from the surface to the depth of e.g. 55 meter with 20 meter spatial resolution or 100 meter with 27 meter resolution in case the density in the conduit is 0.0 g/cm3 and with 71 percent statistical confidence level.

  15. Magnetic resonance imaging of bone marrow changes in Gaucher disease during enzyme replacement therapy: first German long-term results

    Poll, L.W.; Koch, J.A.; Scherer, A.; Boerner, D.; Moedder, U. [Duesseldorf Univ. (Germany). Inst. fuer Diagnostische Radiologie; Dahl, S. vom; Niederau, C.; Haeussinger, D. [Duesseldorf Univ. (Germany). Medizinische Fakultaet; Willers, R. [Duesseldorf Univ. (Germany). Rechenzentrum


    Objective:. Since 1991, enzyme replacement therapy (ERT) has been available for patients with Gaucher disease in Germany. The aim of this study was to analyse the MR pattern of bone marrow involvement and response to ERT in Gaucher disease type I. Patients and design:. Thirty patients with Gaucher disease type I had MRI examinations prior to initiation of ERT with alglucerase/imiglucerase and during follow-up. Median MR follow-up and duration of ERT were 36 months. Coronal T1- and T2-weighted spin-echo images of the lower extremities were obtained to evaluate changes in the appearance of yellow marrow. MR images were categorized as having either a homogeneous (type A) or non-homogeneous patchy (type B) appearance of bone involvement and response to ERT was assessed by two radiologists. Results:. Overall, 19 of 30 patients (63%) showed an increased signal intensity on T1- and T2-weighted images after 36 months of ERT, consistent with partial reconversion of fatty marrow during treatment. Focal bone lesions surrounded by a low signal intensity (SI) rim did not respond to ERT, suggesting bone infarcts. Of the 11 patients with bone infarcts (low SI rim lesion), 82% had the non-homogeneous type B pattern (P=0.0021). In 86% of patients with splenectomy, bone infarcts were seen (P<0.05). Conclusions:. MRI using T1- and T2-weighted spin-echo sequences is a valuable, non-invasive method for monitoring bone marrow response in patients receiving ERT. A non- homogeneous patchy signal intensity of bone marrow involvement correlates with the presence of bone infarcts (P=0.0021). (orig.)

  16. Validation of model-based brain shift correction in neurosurgery via intraoperative magnetic resonance imaging: preliminary results

    Luo, Ma; Frisken, Sarah F.; Weis, Jared A.; Clements, Logan W.; Unadkat, Prashin; Thompson, Reid C.; Golby, Alexandra J.; Miga, Michael I.


    The quality of brain tumor resection surgery is dependent on the spatial agreement between preoperative image and intraoperative anatomy. However, brain shift compromises the aforementioned alignment. Currently, the clinical standard to monitor brain shift is intraoperative magnetic resonance (iMR). While iMR provides better understanding of brain shift, its cost and encumbrance is a consideration for medical centers. Hence, we are developing a model-based method that can be a complementary technology to address brain shift in standard resections, with resource-intensive cases as referrals for iMR facilities. Our strategy constructs a deformation `atlas' containing potential deformation solutions derived from a biomechanical model that account for variables such as cerebrospinal fluid drainage and mannitol effects. Volumetric deformation is estimated with an inverse approach that determines the optimal combinatory `atlas' solution fit to best match measured surface deformation. Accordingly, preoperative image is updated based on the computed deformation field. This study is the latest development to validate our methodology with iMR. Briefly, preoperative and intraoperative MR images of 2 patients were acquired. Homologous surface points were selected on preoperative and intraoperative scans as measurement of surface deformation and used to drive the inverse problem. To assess the model accuracy, subsurface shift of targets between preoperative and intraoperative states was measured and compared to model prediction. Considering subsurface shift above 3 mm, the proposed strategy provides an average shift correction of 59% across 2 cases. While further improvements in both the model and ability to validate with iMR are desired, the results reported are encouraging.

  17. Is there any Correlation between Magnetic Resonance Imaging Features of Breast Lesions of BIRADS Category 4 with Histopathologic Results?

    Maryam Farghadani


    Full Text Available Background: To evaluate the correlation of magnetic resonance imaging (MRI features of breast lesions of Breast Imaging Reporting and Database System (BI-RADS category 4 with histopathologic results. Materials and Methods: In a prospective study between December 2013 and April 2015, patients with suspicious mammographic and/or ultrasound findings referred for Breast MRI were evaluated. Patients with lesions of BI-RADS category 4 were enrolled with a written informed consent. In each patient, mass lesion (ML or nonmass lesion (NML was determined, and different characteristics of the lesions were recorded. A follow-up program was taken with mean 3–12 months. Patients who underwent core needle biopsy or open biopsy were summoned. Results: Seventy-eight females aged 24–67 years (mean 43.1 ± 8.8 met the inclusion criteria and had adequate samples for histopathologic study. Twenty-nine (37.2% patients had ML and 49 (62.8% patients had NML. Tissue sampling in 63 (80.7% patients was through core needle biopsy and in 15 (19.2% patients through surgery. A wide spectrum of benign and malignant pathologic diagnoses was seen. In statistical analysis, none of the MRI features has a significant correlation with any specific histopathologic diagnosis (P = 0.185. However, the relation between the MRI category (ML or NML and pathology results was significant at level of 0.1 (P = 0.06. Conclusion: This study showed that a wide spectrum of histopathologic results is seen in BI-RADS category 4. However, in this sample volume, none of the MRI features in this BI-RADS category has a significant correlation with any specific histopathologic diagnosis.

  18. Investigations into the Impact of the Equivalence Ratio on Turbulent Premixed Combustion Using Particle Image Velocimetry and Large Eddy Simulation Techniques: “V” and “M” Flame Configurations in a Swirl Combustor

    Kewlani, Gaurav


    Turbulent premixed combustion is studied using experiments and numerical simulations in an acoustically uncoupled cylindrical sudden-expansion swirl combustor, and the impact of the equivalence ratio on the flame–flow characteristics is analyzed. In order to numerically capture the inherent unsteadiness exhibited in the flow, the large eddy simulation (LES) technique based on the artificial flame thickening combustion model is employed. The experimental data are obtained using particle image velocimetry. It is observed that changes in heat loading, in the presence of wall confinement, significantly influence the flow field in the wake region, the stabilization location of the flame, and the flame intensity. Specifically, increasing the equivalence ratio drastically reduces the average inner recirculation zone size and causes transition of the flame macrostructure from the “V” configuration to the “M” configuration. In other words, while the flame stabilizes along the inner shear layer for the V flame, a persistent diffuse reaction zone is also manifested along the outer shear layer for the M flame. The average chemiluminescence intensity increases in the case of the M flame macrostructure, while the axial span of the reaction zone within the combustion chamber decreases. The predictions of the numerical approach resemble the experimental observations, suggesting that the LES framework can be an effective tool for examining the effect of heat loading on flame–flow interactions and the mechanism of transition of the flame macrostructure with a corresponding change in the equivalence ratio.

  19. High-contrast imager for complex aperture telescopes (HiCAT): 3. first lab results with wavefront control

    N'Diaye, Mamadou; Mazoyer, Johan; Choquet, Élodie; Pueyo, Laurent; Perrin, Marshall D.; Egron, Sylvain; Leboulleux, Lucie; Levecq, Olivier; Carlotti, Alexis; Long, Chris A.; Lajoie, Rachel; Soummer, Rémi


    HiCAT is a high-contrast imaging testbed designed to provide complete solutions in wavefront sensing, control and starlight suppression with complex aperture telescopes. The pupil geometry of such observatories includes primary mirror segmentation, central obstruction, and spider vanes, which make the direct imaging of habitable worlds very challenging. The testbed alignment was completed in the summer of 2014, exceeding specifications with a total wavefront error of 12nm rms over a 18mm pupil. The installation of two deformable mirrors for wavefront control is to be completed in the winter of 2015. In this communication, we report on the first testbed results using a classical Lyot coronagraph. We also present the coronagraph design for HiCAT geometry, based on our recent development of Apodized Pupil Lyot Coronagraph (APLC) with shaped-pupil type optimizations. These new APLC-type solutions using two-dimensional shaped-pupil apodizer render the system quasi-insensitive to jitter and low-order aberrations, while improving the performance in terms of inner working angle, bandpass and contrast over a classical APLC.

  20. Sensitivity and specificity of narrow-band imaging nasoendoscopy compared to histopathology results in patients with suspected nasopharyngeal carcinoma

    Adham, M.; Musa, Z.; Lisnawati; Suryati, I.


    Nasopharyngeal carcinoma (NPC) is a disease which is prevalent in developing countries like Indonesia. There were 164 new cases of nasopharyngeal carcinoma in the ear, nose, and throat (ENT) oncology outpatient clinic of the Cipto Mangunkusumo hospital in 2014, and 142 cases in 2015. Unfortunately, almost all of these cases presented at an advanced stage. The success of nasopharyngeal carcinoma treatment is largely determined by the stage when patients are diagnosed; it is critical to diagnose NPC as early as possible. Narrow-band imaging (NBI) is an endoscopic instrument with a light system that can improve the visualization of blood vessels of mucosal epithelial malignant tumors. NBI is expected to help clinicians to assess whether a lesion is malignant or not; to do so, it is important to know the value of sensitivity and specificity. This study is a cross-sectional form of a diagnostic test which was performed in the outpatient clinic of the ENT Head and Neck Surgery Department for the Cipto Mangunkusumo Hospital, from January to June 2016, and involved 56 subjects. Patients with a nasopharyngeal mass discovered by physical examination or imaging, and a suspected nasopharyngeal carcinoma were included as a subject. An NBI examination and biopsy was performed locally. Based on this research, NBI could be used as a screening tool for nasopharyngeal carcinoma with high sensitivity (100%), but with a low specificity result (6.7%).

  1. Is there any Correlation between Magnetic Resonance Imaging Features of Breast Lesions of BIRADS Category 4 with Histopathologic Results?

    Farghadani, Maryam; Soofi, Ghazale Jamalipoor; Sarrami, Amir Hossein


    To evaluate the correlation of magnetic resonance imaging (MRI) features of breast lesions of Breast Imaging Reporting and Database System (BI-RADS) category 4 with histopathologic results. In a prospective study between December 2013 and April 2015, patients with suspicious mammographic and/or ultrasound findings referred for Breast MRI were evaluated. Patients with lesions of BI-RADS category 4 were enrolled with a written informed consent. In each patient, mass lesion (ML) or nonmass lesion (NML) was determined, and different characteristics of the lesions were recorded. A follow-up program was taken with mean 3-12 months. Patients who underwent core needle biopsy or open biopsy were summoned. Seventy-eight females aged 24-67 years (mean 43.1 ± 8.8) met the inclusion criteria and had adequate samples for histopathologic study. Twenty-nine (37.2%) patients had ML and 49 (62.8%) patients had NML. Tissue sampling in 63 (80.7%) patients was through core needle biopsy and in 15 (19.2%) patients through surgery. A wide spectrum of benign and malignant pathologic diagnoses was seen. In statistical analysis, none of the MRI features has a significant correlation with any specific histopathologic diagnosis (P = 0.185). However, the relation between the MRI category (ML or NML) and pathology results was significant at level of 0.1 (P = 0.06). This study showed that a wide spectrum of histopathologic results is seen in BI-RADS category 4. However, in this sample volume, none of the MRI features in this BI-RADS category has a significant correlation with any specific histopathologic diagnosis.

  2. Dynamic pelvic floor MR imaging at 3 T in patients with clinical signs of urinary incontinence-preliminary results

    Morakkabati-Spitz, Nuschin; Willinek, Winfried A.; Traeber, Frank; Jaeger, Ursula; Schild, Hans H. [University of Bonn, Department of Radiology, Bonn (Germany); Gieseke, Juergen [University of Bonn, Department of Radiology, Bonn (Germany); Philips Medical Systems, Best (Netherlands); Bastian, Patrick J. [University of Munich, Department of Urology, Munich (Germany); Schmitz, Bettina; Mueller, Stefan C. [University of Bonn, Department of Urology, Bonn (Germany)


    To prospectively evaluate feasibility, image quality and diagnostic accuracy of dynamic MR imaging the pelvic floor at 3.0 T in patients with urinary incontinence and to compare these results with those of MRI performed at 1.5 T. Ten patients with the diagnosis of urinary incontinence (clinical symptoms, clinical examination, pelvic ultrasound) were examined with a dynamic balanced FFE (B-FFE) sequence at 1.5 T and 3.0 T on the same day in a randomized order. Spatial (1.5 x 1.5 x 8 mm) and temporal (0.44 s) resolution at 3.0 T were comparable to the 1.5-T B-FFE sequence. Two radiologists assessed visual signal to noise (three-point scale), artefact level (five-point scale) and final MR diagnoses with regard to pelvic floor weakness (independent analysis). The diagnoses obtained at 1.5-T field strength and the results of the clinical tests served as standard of reference. In addition, ROI-based quantitative measurements were performed to assess different tissue contrasts at both field strengths. Data were analyzed for statistical differences by using the Wilcoxon's matched pairs test and the marginal homogeneity test. Visual signal to noise was rated higher at 3.0 T for all ten studies by both radiologists. With regard to artefact level, there was no statistically significant difference between the studies obtained at 3.0 T as compared to the corresponding 1.5-T studies (marginal homogeneity test: p = 0.18 for reviewer 1 and 0.41 for reviewer 2). Mean artefact level was rated minor to moderate by both reviewers for both field strengths (excellent interobserver agreement with Kendall-W value of 0.973). Except for a higher tissue contrast between fat and urethra at 1.5 T, there were no statistically significant differences between tissue contrast at 1.5 T as compared to 3.0 T (Wilcoxon's test). Final MR diagnoses regarding pelvic floor weakness did not differ between 3.0-T and 1.5-T field strength and correlated well with the results of the clinical tests

  3. Patient management after noninvasive cardiac imaging results from SPARC (Study of myocardial perfusion and coronary anatomy imaging roles in coronary artery disease).

    Hachamovitch, R.; Nutter, B.; Hlatky, M.A.; Shaw, L.J.; Ridner, M.L.; Dorbala, S.; Beanlands, R.S.; Chow, B.J.; Branscomb, E.; Chareonthaitawee, P.; Weigold, W.G.; Voros, S.; Abbara, S.; Yasuda, T.; Jacobs, J.E.; Lesser, J.; Berman, D.S.; Thomson, L.E.; Raman, S.; Heller, G.V.; Schussheim, A.; Brunken, R.; Williams, K.A.; Farkas, S.; Delbeke, D.; Schoepf, U.J.; Reichek, N.; Rabinowitz, S.; Sigman, S.R.; Patterson, R.; Corn, C.R.; White, R.; Kazerooni, E.; Corbett, J.; Bokhari, S.; Machac, J.; Guarneri, E.; Borges-Neto, S.; Millstine, J.W.; Caldwell, J.; Arrighi, J.; Hoffmann, U.; Budoff, M.; Lima, J.; Johnson, J.R.; Johnson, B.; Gaber, M.; Williams, J.A.; Foster, C.; Hainer, J.; Carli, M.F. Di


    OBJECTIVES: This study examined short-term cardiac catheterization rates and medication changes after cardiac imaging. BACKGROUND: Noninvasive cardiac imaging is widely used in coronary artery disease, but its effects on subsequent patient management are unclear. METHODS: We assessed the 90-day post

  4. Geometry of the Farallon Slab Revealed by Joint Interpretation of Wavefield Imaging and Tomography Results from the Earthscope Transportable Array

    Pavlis, G. L.; Wang, Y.


    A significant number of P and S wave tomography models have been produced in the past decade using various subsets of data from the Earthscope USArray and different inversion algorithms. We focus here on published tomography results that span large portions of the final footprint of the USArray. We use 3D visualization techniques to search for common features in different tomography models. We also compare tomography results to features seen in our current generation wavefield images. Recent innovations of our plane wave migration method have yielded what is arguably the highest resolution image ever produced of the mantle in the vicinity of the transition zone. The new results reveal a rich collection of coherent, dipping structures seen throughout the upper mantle and transition zone. These dipping interfaces are judged significant according to a coherence metric. We treat these surfaces as strain markers to assess proposed models for geometry of the 3D geometry of the Farallon Slab under North America. We find the following geologic interpretations are well supported by independent results: 1. The old Farallon under eastern North America and below the base of transition zone is universally seen as a high velocity anomaly. 2. All results support a simple, 3D kinematic model of the updip limit of the Farallon slab window that follows a track from Cape Mendocino, across Nevada, and northern Arizona and New Mexico. 3. All models show a strong low-velocity mantle under the southwestern U.S. 4. A low-velocity features is universally seen related to the Yellowstone-Snake River system. Shorter wavelength features observed in different tomography models are inconsistent showing that the theme of this session is very important to understand what features are in current results are real. Isopach maps of the thickness of the transition show a systematic difference in transition zone thickness in the western and eastern US. The transition zone thickens in the eastern US in

  5. [Imaging].

    Chevrot, A; Drapé, J L; Godefroy, D; Dupont, A M; Pessis, E; Sarazin, L; Minoui, A


    The panoply of imaging techniques useful in podology is essentially limited to X-rays. Standard "standing" and "lying" X-rays furnish most of the required information. Arthrography is sometimes performed, in particular for trauma or tumour of the ankle. CT scan and MRI make a decisive contribution in difficult cases, notably in fractures and in small fractures without displacement. The two latter techniques are useful in tendon, ligament and muscular disorders, where echography is also informative. Rigorous analysis of radiographies and a good knowledge of foot disorders make these imaging techniques efficacious.

  6. Information preserving image compression for archiving NMR images.

    Li, C C; Gokmen, M; Hirschman, A D; Wang, Y


    This paper presents a result on information preserving compression of NMR images for the archiving purpose. Both Lynch-Davisson coding and linear predictive coding have been studied. For NMR images of 256 x 256 x 12 resolution, the Lynch-Davisson coding with a block size of 64 as applied to prediction error sequences in the Gray code bit planes of each image gave an average compression ratio of 2.3:1 for 14 testing images. The predictive coding with a third order linear predictor and the Huffman encoding of the prediction error gave an average compression ratio of 3.1:1 for 54 images under test, while the maximum compression ratio achieved was 3.8:1. This result is one step further toward the improvement, albeit small, of the information preserving image compression for medical applications.

  7. Initial Results of Image-Guided Percutaneous Ablation as Second-Line Treatment for Symptomatic Vascular Anomalies

    Thompson, Scott M., E-mail: [Mayo Clinic, Mayo Graduate School, Mayo Medical School and the Mayo Clinic Medical Scientist Training Program, College of Medicine (United States); Callstrom, Matthew R., E-mail:; McKusick, Michael A., E-mail:; Woodrum, David A., E-mail: [Mayo Clinic, Department of Radiology, College of Medicine (United States)


    PurposeThe purpose of this study was to determine the feasibility, safety, and early effectiveness of percutaneous image-guided ablation as second-line treatment for symptomatic soft-tissue vascular anomalies (VA).Materials and MethodsAn IRB-approved retrospective review was undertaken of all patients who underwent percutaneous image-guided ablation as second-line therapy for treatment of symptomatic soft-tissue VA during the period from 1/1/2008 to 5/20/2014. US/CT- or MRI-guided and monitored cryoablation or MRI-guided and monitored laser ablation was performed. Clinical follow-up began at one-month post-ablation.ResultsEight patients with nine torso or lower extremity VA were treated with US/CT (N = 4) or MRI-guided (N = 2) cryoablation or MRI-guided laser ablation (N = 5) for moderate to severe pain (N = 7) or diffuse bleeding secondary to hemangioma–thrombocytopenia syndrome (N = 1). The median maximal diameter was 9.0 cm (6.5–11.1 cm) and 2.5 cm (2.3–5.3 cm) for VA undergoing cryoablation and laser ablation, respectively. Seven VA were ablated in one session, one VA initially treated with MRI-guided cryoablation for severe pain was re-treated with MRI-guided laser ablation due to persistent moderate pain, and one VA was treated in a planned two-stage session due to large VA size. At an average follow-up of 19.8 months (range 2–62 months), 7 of 7 patients with painful VA reported symptomatic pain relief. There was no recurrence of bleeding at five-year post-ablation in the patient with hemangioma–thrombocytopenia syndrome. There were two minor complications and no major complications.ConclusionImage-guided percutaneous ablation is a feasible, safe, and effective second-line treatment option for symptomatic VA.

  8. Contribution of image analysis to the definition of explosibility of fine particles resulting from waste recycling process

    Gente, V.; La Marca, F.


    In waste recycling processes, the development of comminution technologies is one of the main actions to improve the quality of recycled products. This involves a rise in fine particles production, which could have some effects on explosibility properties of materials. This paper reports the results of experiments done to examine the explosibility of the fine particles resulting from waste recycling process. Tests have been conducted for the products derived from milling processes operated in different operative conditions. In particular, the comminution tests have been executed varying the milling temperature by refrigerant agents. The materials utilized in explosibility tests were different typologies of plastics coming from waste products (PET, ABS and PP), characterized by size lower than 1 mm. The results of explosibility tests, carried out by mean of a Hartmann Apparatus, have been compared with the data derived from image analysis procedure aimed to measure the morphological characteristics of particles. For each typology of material, the propensity to explode appears to be correlated not only to particle size, but also to morphological properties, linked to the operative condition of the milling process.

  9. Endometrial cancer: results of clinical and histopathological staging compared to magnetic resonance imaging using an endorectal surface coil.

    Brocker, Kerstin A; Alt, Céline D; Breyer, Ulrike; Hallscheidt, Peter; Sohn, Christof


    The aim of this study was to evaluate the staging accuracy of magnetic resonance imaging (MRI) with an endorectal surface coil on patients with endometrial cancer compared to results obtained using the International Federation of Gynecology and Obstetrics (FIGO) classification and histopathology. In this prospective study, patients with biopsy-proven endometrial cancer were staged clinically using the FIGO classification before undergoing 1.5 T MRI with an endorectal surface coil (eMRI). The staging results from the FIGO classification and from eMRI were compared with the histopathological results after surgery. Furthermore, each patient was given a questionnaire designed by the authors to evaluate the patients' opinions on eMRI. The responses were examined using the methods of descriptive analysis. A total of 33 consecutive patients were recruited and clinically staged before undergoing eMRI. Subsequently, 21 patients underwent primary surgery and 12 patients primary radiochemotherapy. The FIGO stages were identical to the histopathological results in 17 (81 %) cases, and those of eMRI were identical in 15 (71 %). In 13 (62 %) cases, FIGO and eMRI staged identically. In 12 (57 %) of the 21 cases, all three staging modalities diagnosed the same tumor stage. eMRI overstaged the tumor in four patients and understaged it in two. All T1a tumors were staged correctly by eMRI. Eighteen patients answered the questionnaire, of whom 11 (61 %) patients stated that their experience with eMRI was overall positive. It seems feasible in principle to employ eMRI for diagnosing patients with endometrial cancer stage T1a. Yet, the results of eMRI for our study population were not better than the results obtained using the FIGO classification or than those from using MRI without an endorectal surface coil. eMRI thus does not meet the expectations based on its use in other pelvic tumor entities.

  10. Structured-light Image Compression Based on Fractal Theory


    The method of fractal image compression is introduced which is applied to compress the line structured-light image. Based on the self-similarity of the structured-light image, we attain satisfactory compression ratio and higher peak signal-to-noise ratio (PSNR). The experimental results indicate that this method can achieve high performance.

  11. A Technique for Determining Relaxation Times by Free-Flight Tests of Low-Fineness-Ratio Cones; with Experimental Results for Air at Equilibrium Temperatures up to 3440 K

    Stephenson, Jack D.


    This report describes a technique which combines theory and experiments for determining relaxation times in gases. The technique is based on the measurement of shapes of the bow shock waves of low-fineness-ratio cones fired from high-velocity guns. The theory presented in the report provides a means by which shadowgraph data showing the bow waves can be analyzed so as to furnish effective relaxation times. Relaxation times in air were obtained by this technique and the results have been compared with values estimated from shock tube measurements in pure oxygen and nitrogen. The tests were made at velocities ranging from 4600 to 12,000 feet per second corresponding to equilibrium temperatures from 35900 R (19900 K) to 6200 R (34400 K), under which conditions, at all but the highest temperatures, the effective relaxation times were determined primarily by the relaxation time for oxygen and nitrogen vibrations.

  12. Surgical results in hidden lumbar spinal stenosis detected by axial loaded computed tomography and magnetic resonance imaging: an outcome study.

    Willén, Jan; Wessberg, Per J; Danielsson, Barbro


    An outcome study of patients with neurogenic claudication and/or sciatica with hidden stenosis, detected only by axial loading of the lumbar spine (ACE) but not at the traditional unloaded examination (psoas relaxed position) during computed tomography (CT) myelography or magnetic resonance imaging (MRI), followed up after surgery. To estimate the clinical effect of decompression with or without fusion in patients with hidden stenosis in the lumbar spine. A number of patients with neurogenic claudicatio with or without sciatica do not have corresponding imaging abnormalities. Axial loaded CT and MRI have disclosed hidden stenosis in certain cases. The surgical effect in patients with hidden stenosis has never been described. Axial loading of the lumbar spine during CT and MRI was performed in 250 patients with neurogenic claudication and sciatica. All fulfilled the inclusion criteria for ACE, i.e., suspected but not verified spinal stenosis in 1 to 3 levels. In 125 patients (50%), a significant narrowing of the spinal canal occurred. Out of these 125 patients, 101 had a clear stenosis besides the stenosis only detected at ACE. In 24 patients, a hidden stenosis was detected in 1 to 3 levels only at the ACE. These patients were observed for 1 to 6 years after decompression with or without fusion regarding subjective improvement of leg and back pains, walking capacity, satisfaction, and health related quality of life. At follow-up, 76% of the patients had leg pain less than 25/100 on a VAS scale and 62% had back pain less than 25/100. Ninety-six percent were improved or much improved regarding leg and back pains The ability to walk increased significantly after surgery. Walking capacity to more than 500 m increased from 4% to 87%. Twenty-two patients were subjectively satisfied with the surgical results. The ODI score, the SF-36 and the EQ-5D score corresponded well to the above mentioned improvements at follow-up. According to this study, the results of surgery in

  13. Compact Hyperspectral Imaging System (cosi) for Small Remotely Piloted Aircraft Systems (rpas) - System Overview and First Performance Evaluation Results

    Sima, A. A.; Baeck, P.; Nuyts, D.; Delalieux, S.; Livens, S.; Blommaert, J.; Delauré, B.; Boonen, M.


    This paper gives an overview of the new COmpact hyperSpectral Imaging (COSI) system recently developed at the Flemish Institute for Technological Research (VITO, Belgium) and suitable for remotely piloted aircraft systems. A hyperspectral dataset captured from a multirotor platform over a strawberry field is presented and explored in order to assess spectral bands co-registration quality. Thanks to application of line based interference filters deposited directly on the detector wafer the COSI camera is compact and lightweight (total mass of 500g), and captures 72 narrow (FWHM: 5nm to 10 nm) bands in the spectral range of 600-900 nm. Covering the region of red edge (680 nm to 730 nm) allows for deriving plant chlorophyll content, biomass and hydric status indicators, making the camera suitable for agriculture purposes. Additionally to the orthorectified hypercube digital terrain model can be derived enabling various analyses requiring object height, e.g. plant height in vegetation growth monitoring. Geometric data quality assessment proves that the COSI camera and the dedicated data processing chain are capable to deliver very high resolution data (centimetre level) where spectral information can be correctly derived. Obtained results are comparable or better than results reported in similar studies for an alternative system based on the Fabry-Pérot interferometer.

  14. Imaging of primary and secondary radiation-Modelling and experimental results of a radioactive source and a water phantom

    Gamage, K. A. A.; Taylor, G. C.; Joyce, M. J.


    In this paper the contribution of primary and secondary radiation from a water phantom to a pinhole volume, as a result of three neutron sources (Cf, AmBe and 5 MeV mono-energetic) and two gamma sources (Cs and Co), is separately estimated using the PTRAC particle tracking option available in MCNP. Also in this paper imaging of the mixed radiation field produced by a Van de Graaf accelerator (when a water phantom is present) is described. In the model, a spherical tally volume, 2 cm in diameter, was placed equidistantly from a radioactive source and 30×30×15 cm3 water phantom. Monte Carlo simulations have been carried out to investigate the level of primary and secondary radiation contributing to the pinhole volume directly from the source and from interactions in the phantom respectively. The spatial distribution of counts clearly discriminated the source and the phantom. The results have shown that the percentage of neutrons reflected from the phantom with energies above 1 MeV increases with mean energy of the source. This method has significant potential to characterise secondary radiation in proton therapy, where it would help to verify the location and the energy delivered during the treatment.

  15. Late Quaternary Incisions and Related Shallow Subsurface Stratigraphy on the New Jersey Mid-Outer Shelf: Preliminary Results from Ultra-High Resolution Chirp Sonar Images - Part I

    Nordfjord, S.; Gulick, S. P.; Austin, J. A.; Goff, J. A.; Fulthorpe, C. S.


    ONR's Geoclutter program is a multi-year initiative to investigate systematic relationships between geologic phenomena and discrete acoustic signals ("geoclutter"). The New Jersey middle and outer shelf is the natural laboratory for Geoclutter because of the abundance of surficial geologic structures, including complex dendritic networks of fluvial (?) channels shallowly buried below the seafloor. Their geophysical characterization includes collection of high resolution seismic data in August-September 2001, using a deep-towed chirp sonar aboard the R/V Endeavor. These data image the upper ~30 m of sediments at ~2 m horizontal resolution and ~10 cm vertical resolution. Track spacing is typically 200 m. This resolution allows us to resolve subsurface structures in greater detail and over a wider range of spatial scales than previous imaging efforts using boomer sources. We present preliminary results from the central portion of the survey, a ~20x30 km area covering two separate dendritic systems. Principal drainage axes of buried channels are oriented NW to SE. Multiple incisions include cut-and-fill morphologies that characterize the channel fills, suggesting a complicated history since the last eustatic lowstand, ~20-22 ka. Both flat-lying and chaotic reflections are imaged within the fills, suggesting that infilling occurred episodically, in response to high-order relative base-level variations, and under fluctuating energy conditions. Channel-fills are often capped with a thin veneer of sand deposited after channel-filling; this has been confirmed by recent grab sampling geoclutter aboard R/V Cape Henlopen. These sediments appear to have been deposited during the last glacio-eustatic cycle (~100 kyr). A regionally important seismic reflector mappable throughout the middle to outer shelf, "R", has been interpreted as an erosional surface created during the last regression. This hypothesis is supported by the few age constraints currently available (AMS Carbon-14

  16. First determination of the heart-to-mediastinum ratio using cardiac dual isotope ({sup 123}I-MIBG/{sup 99m}Tc-tetrofosmin) CZT imaging in patients with heart failure: the ADRECARD study

    Bellevre, Dimitri; Desmonts, Cedric [CHU Cote de Nacre, Department of Nuclear Medicine, Caen (France); Manrique, Alain; Agostini, Denis [CHU Cote de Nacre, Department of Nuclear Medicine, Caen (France); EA 4650, Normandie Universite, Caen (France); Legallois, Damien [EA 4650, Normandie Universite, Caen (France); CHU Cote de Nacre, Cardiology Department, Caen (France); Bross, Samy; Baavour, Rafael; Roth, Nathaniel [Spectrum Dynamics, Biosensors, Caesarea (Israel); Blaire, Tanguy; Bailliez, Alban [EA 4650, Normandie Universite, Caen (France); IRIS, Polyclinique du Bois, Nuclear Medicine Department, Lille (France)


    Cardiac innervation is assessed using the heart-to-mediastinum ratio (HMR) of metaiodobenzylguanidine (MIBG) on planar imaging using Anger single photon emission computed tomography (A-SPECT). The aim of the study was to determine the HMR of MIBG obtained using a CZT-based camera (D-SPECT; Spectrum Dynamics, Israel) in comparison with that obtained using conventional planar imaging. The ADRECARD study prospectively evaluated 44 patients with heart failure. They underwent planar acquisition using the A-SPECT camera 4 h after {sup 123}I-MIBG injection (236.4 ± 39.7 MBq). To localize the heart using D-SPECT, {sup 99m}Tc-tetrofosmin (753 ± 133 MBq) was administered and dual isotope acquisition was performed using the D-SPECT system. HMR was calculated using both planar A-SPECT imaging and front view D-SPECT cine data. In a phantom study, we estimated a model fitting the A-SPECT and the D-SPECT data that was further applied to correct for differences between the cameras. A total of 44 patients (39 men and 5 women, aged 60 ± 11 years) with ischaemic (31 patients) and nonischaemic (13 patients) cardiomyopathy completed the study. Most patients (28 of 44) were NYHA class II, and the mean left ventricular ejection fraction was 33 ± 7 %. The mean HMR values were 1.34 ± 0.15 and 1.45 ± 0.27 from A-SPECT and D-SPECT, respectively (p < 0.0001). After correction, Lin's concordance correlation showed an almost perfect concordance between corrected D-SPECT HMR and A-SPECT HMR, and Bland-Altman analysis demonstrated a high agreement between the two measurements. The ADRECARD study demonstrated that determination of late HMR during cardiac MIBG imaging using dual isotope ({sup 123}I and {sup 99m}Tc) acquisition on a CZT camera (D-SPECT) is feasible in patients with heart failure. A linear correction based on the phantom study yielded a high agreement between {sup 123}I MIBG HMR obtained using a CZT camera and that from conventional planar imaging. (orig.)

  17. Evaluation of diffuse diseases of the upper abdominal organs by MRI. Determination of a normal range in signal intensity ratio of each organ to the renal medulla in T1- and T2-weighted images and evaluation of diffuse diseases of an organ by using it

    Mitsuhashi, Hiroshi [Saint Marianna Univ., Kawasaki, Kanagawa (Japan). School of Medicine


    Diffuse diseases of the upper abdominal organs, including the liver, spleen, pancreas, and vertebral marrow, were evaluated by using signal intensity ratio of each organ to the renal medulla in T1- and T2-weighted images. Conventional T1- and T2-weighted images were obtained in 1.5 T MR system in 203 persons, including 122 controls and 81 patients with a diffuse disease in the upper abdominal organ. In controls, though there was neither sexual nor age difference in signal intensity ratios of the liver and pancreas, those of the spleen and vertebral marrow showed sexual and age difference, respectively. A normal range of signal intensity ratio of each organ in each image was determined in each decade of each sex by using controls. The signal intensity ratio of the liver was significantly low in T1- and T2-weighted images in patients with abundant iron deposit and within normal limits in patients with liver cirrhosis or scant iron deposit. The signal intensity ratio of the liver was significantly high only in a T2-weighted image in patients with fatty deposit in the liver, which was suspected to be due to inflammatory change in the liver with fatty deposit. The signal intensity ratios of the spleen, pancreas, and vertebral marrow were significantly low only in a T2-weighted image in patients with iron metabolic disturbance. The signal intensity ratio of the pancreas was significantly high in 40% of patients with acute and/or chronic pancreatitis, which was more sensitive in detection of pancreatitis than data in other studies. it can be concluded that the signal intensity ratio of each organ to the renal medulla in T1- and T2-weighted images is useful for detection of diffuse diseases of the upper abdominal organs by using the normal range in each decade of each sex. (S.Y.).

  18. The Dependence of Signal-To-Noise Ratio (S/N) Between Star Brightness and Background on the Filter Used in Images Taken by the Vulcan Photometric Planet Search Camera

    Mena-Werth, Jose


    The Vulcan Photometric Planet Search is the ground-based counterpart of Kepler Mission Proposal. The Kepler Proposal calls for the launch of telescope to look intently at a small patch of sky for four year. The mission is designed to look for extra-solar planets that transit sun-like stars. The Kepler Mission should be able to detect Earth-size planets. This goal requires an instrument and software capable of detecting photometric changes of several parts per hundred thousand in the flux of a star. The goal also requires the continuous monitoring of about a hundred thousand stars. The Kepler Mission is a NASA Discovery Class proposal similar in cost to the Lunar Prospector. The Vulcan Search is also a NASA project but based at Lick Observatory. A small wide-field telescope monitors various star fields successively during the year. Dozens of images, each containing tens of thousands of stars, are taken any night that weather permits. The images are then monitored for photometric changes of the order of one part in a thousand. These changes would reveal the transit of an inner-orbit Jupiter-size planet similar to those discovered recently in spectroscopic searches. In order to achieve a one part in one thousand photometric precision even the choice of a filter used in taking an exposure can be critical. The ultimate purpose of an filter is to increase the signal-to-noise ratio (S/N) of one's observation. Ideally, filters reduce the sky glow cause by street lights and, thereby, make the star images more distinct. The higher the S/N, the higher is the chance to observe a transit signal that indicates the presence of a new planet. It is, therefore, important to select the filter that maximizes the S/N.

  19. Constraining the Frequency of Free-Floating Planets from a Synthesis of Microlensing, Radial Velocity, and Direct Imaging Survey Results

    Clanton, Christian


    A microlensing survey by Sumi et al. (2011) exhibits an overabundance of short-timescale events (STEs; t_E~10 AU) and free-floating planets. Assuming these STEs are indeed due to planetary-mass objects, we aim to constrain the fraction of these events that can be explained by bound but wide-separation planets. We fit the observed timescale distribution with a lens mass function comprised of brown dwarfs, main-sequence stars, and stellar remnants, finding and thus corroborating the initial identification of an excess of STEs. We then include a population of bound planets that are expected not to show signatures of the primary lens (host) in their microlensing light curves and that are also consistent with results from representative microlensing, radial velocity, and direct imaging surveys. We find that bound planets alone cannot explain the entire STE excess without violating the constraints from the surveys we consider and thus some fraction of these events must be due to free-floating planets, if our model ...

  20. Tomographic imaging of Central Java, Indonesia: Preliminary result of joint inversion of the MERAMEX and MCGA earthquake data

    Rohadi, Supriyanto [Study Program of Earth Sciences, Faculty of Earth Sciences and Technology, Institute of Technology Bandung, Jl. Ganesha No.10, Bandung 40132, Indonesia and Meteorological, Climatological, and Geophysical Agency, Jl. Angkasa 1 No.2, Kemayoran, Jakarta (Indonesia); Widiyantoro, Sri; Nugraha, Andri Dian [Global Geophysics Research Group, Faculty of Mining and Petroleum Engineering, Institute of Technology Bandung, Jl. Ganesha No.10, Bandung 40132 (Indonesia); Masturyono [Meteorological, Climatological, and Geophysical Agency, Jl. Angkasa 1 No.2, Kemayoran, Jakarta Pusat (Indonesia)


    The realization of local earthquake tomography is usually conducted by removing distant events outside the study region, because these events may increase errors. In this study, tomographic inversion has been conducted using the travel time data of local and regional events in order to improve the structural resolution, especially for deep structures. We used the local MERapi Amphibious EXperiments (MERAMEX) data catalog that consists of 292 events from May to October 2004. The additional new data of regional events in the Java region were taken from the Meteorological, Climatological, and Geophysical Agency (MCGA) of Indonesia, which consist of 882 events, having at least 10 recording phases at each seismographic station from April 2009 to February 2011. We have conducted joint inversions of the combined data sets using double-difference tomography to invert for velocity structures and to conduct hypocenter relocation simultaneously. The checkerboard test results of Vp and Vs structures demonstrate a significantly improved spatial resolution from the shallow crust down to a depth of 165 km. Our tomographic inversions reveal a low velocity anomaly beneath the Lawu - Merapi zone, which is consistent with the results from previous studies. A strong velocity anomaly zone with low Vp, low Vs and low Vp/Vs is also identified between Cilacap and Banyumas. We interpret this anomaly as a fluid content material with large aspect ratio or sediment layer. This anomaly zone is in a good agreement with the existence of a large dome containing sediment in this area as proposed by previous geological studies. A low velocity anomaly zone is also detected in Kebumen, where it may be related to the extensional oceanic basin toward the land.

  1. Tomographic imaging of Central Java, Indonesia: Preliminary result of joint inversion of the MERAMEX and MCGA earthquake data

    Rohadi, Supriyanto; Widiyantoro, Sri; Nugraha, Andri Dian; Masturyono


    The realization of local earthquake tomography is usually conducted by removing distant events outside the study region, because these events may increase errors. In this study, tomographic inversion has been conducted using the travel time data of local and regional events in order to improve the structural resolution, especially for deep structures. We used the local MERapi Amphibious EXperiments (MERAMEX) data catalog that consists of 292 events from May to October 2004. The additional new data of regional events in the Java region were taken from the Meteorological, Climatological, and Geophysical Agency (MCGA) of Indonesia, which consist of 882 events, having at least 10 recording phases at each seismographic station from April 2009 to February 2011. We have conducted joint inversions of the combined data sets using double-difference tomography to invert for velocity structures and to conduct hypocenter relocation simultaneously. The checkerboard test results of Vp and Vs structures demonstrate a significantly improved spatial resolution from the shallow crust down to a depth of 165 km. Our tomographic inversions reveal a low velocity anomaly beneath the Lawu - Merapi zone, which is consistent with the results from previous studies. A strong velocity anomaly zone with low Vp, low Vs and low Vp/Vs is also identified between Cilacap and Banyumas. We interpret this anomaly as a fluid content material with large aspect ratio or sediment layer. This anomaly zone is in a good agreement with the existence of a large dome containing sediment in this area as proposed by previous geological studies. A low velocity anomaly zone is also detected in Kebumen, where it may be related to the extensional oceanic basin toward the land.

  2. Contrast-enhanced, real-time volumetric ultrasound imaging of tissue perfusion: preliminary results in a rabbit model of testicular torsion

    Paltiel, H. J.; Padua, H. M.; Gargollo, P. C.; Cannon, G. M., Jr.; Alomari, A. I.; Yu, R.; Clement, G. T.


    Contrast-enhanced ultrasound (US) imaging is potentially applicable to the clinical investigation of a wide variety of perfusion disorders. Quantitative analysis of perfusion is not widely performed, and is limited by the fact that data are acquired from a single tissue plane, a situation that is unlikely to accurately reflect global perfusion. Real-time perfusion information from a tissue volume in an experimental rabbit model of testicular torsion was obtained with a two-dimensional matrix phased array US transducer. Contrast-enhanced imaging was performed in 20 rabbits during intravenous infusion of the microbubble contrast agent Definity® before and after unilateral testicular torsion and contralateral orchiopexy. The degree of torsion was 0° in 4 (sham surgery), 180° in 4, 360° in 4, 540° in 4, and 720° in 4. An automated technique was developed to analyze the time history of US image intensity in experimental and control testes. Comparison of mean US intensity rate of change and of ratios between mean US intensity rate of change in experimental and control testes demonstrated good correlation with testicular perfusion and mean perfusion ratios obtained with radiolabeled microspheres, an accepted 'gold standard'. This method is of potential utility in the clinical evaluation of testicular and other organ perfusion.

  3. Mathematics education graduate students' understanding of trigonometric ratios

    Yiǧit Koyunkaya, Melike


    This study describes mathematics education graduate students' understanding of relationships between sine and cosine of two base angles in a right triangle. To explore students' understanding of these relationships, an elaboration of Skemp's views of instrumental and relational understanding using Tall and Vinner's concept image and concept definition was developed. Nine students volunteered to complete three paper and pencil tasks designed to elicit evidence of understanding and three students among these nine students volunteered for semi-structured interviews. As a result of fine-grained analysis of the students' responses to the tasks, the evidence of concept image and concept definition as well as instrumental and relational understanding of trigonometric ratios was found. The unit circle and a right triangle were identified as students' concept images, and the mnemonic was determined as their concept definition for trigonometry, specifically for trigonometric ratios. It is also suggested that students had instrumental understanding of trigonometric ratios while they were less flexible to act on trigonometric ratio tasks and had limited relational understanding. Additionally, the results indicate that graduate students' understanding of the concept of angle mediated their understanding of trigonometry, specifically trigonometric ratios.

  4. Intercomparison of four airborne imaging DOAS systems for tropospheric NO2 mapping - First results of the AROMAPEX campaign

    Tack, Frederik; Merlaud, Alexis; Meier, Andreas; Ge, Xinrui; Meuleman, Koen; Ruhtz, Thomas; van der Wal, Len; Van Roozendael, Michel; Iordache, Daniel; Schönhardt, Anja; Richter, Andreas; Vlemmix, Tim; de Goeij, Bryan; Ardelean, Magdalena; Boscornea, Andreea; Constantin, Daniel; Shaifangar, Reza; Wagner, Thomas; Lampel, Johannes; Schuettemeyer, Dirk


    campaigns held in April, 2015 and July, 2016 in Belgium. We present first results</