WorldWideScience

Sample records for scanning imaging device

  1. An image scanning device using radiating energy

    International Nuclear Information System (INIS)

    Jacob, Daniel.

    1976-01-01

    Said invention relates to an image scanning device using radiating energy. More particularly, it relates to a device for generating a scanning beam of rectangular cross section from a γ or X-ray source. Said invention can be applied to radiographic units of the 'microdose' type used by airline staffs and others for the fast efficient inspection of luggage and parcels in view of detecting hidden things [fr

  2. Device for the track useful signal discrimination during the image scanning form bubble chambers

    International Nuclear Information System (INIS)

    Osipov, E.A.; Uvarov, V.A.

    1976-01-01

    A device for the image processing from the bubble chambers, developed to increase the reliability of the track useful signal discrimination at the image scanning from the background component is described. The device consists of a low-pass filter, repetition and memory circuit and subtraction circuit. Besides a delay line and extra channel consisting of a differentiating circuit in series with the selective shaping circuit are introduced into the device. The output signal of the selective shaping is the controlling signal of the repetition and memory circuit, at the output of which a signal corresponding the background component is formed. The functional diagram of the device operation is presented

  3. An improved three-dimensional non-scanning laser imaging system based on digital micromirror device

    Science.gov (United States)

    Xia, Wenze; Han, Shaokun; Lei, Jieyu; Zhai, Yu; Timofeev, Alexander N.

    2018-01-01

    Nowadays, there are two main methods to realize three-dimensional non-scanning laser imaging detection, which are detection method based on APD and detection method based on Streak Tube. However, the detection method based on APD possesses some disadvantages, such as small number of pixels, big pixel interval and complex supporting circuit. The detection method based on Streak Tube possesses some disadvantages, such as big volume, bad reliability and high cost. In order to resolve the above questions, this paper proposes an improved three-dimensional non-scanning laser imaging system based on Digital Micromirror Device. In this imaging system, accurate control of laser beams and compact design of imaging structure are realized by several quarter-wave plates and a polarizing beam splitter. The remapping fiber optics is used to sample the image plane of receiving optical lens, and transform the image into line light resource, which can realize the non-scanning imaging principle. The Digital Micromirror Device is used to convert laser pulses from temporal domain to spatial domain. The CCD with strong sensitivity is used to detect the final reflected laser pulses. In this paper, we also use an algorithm which is used to simulate this improved laser imaging system. In the last, the simulated imaging experiment demonstrates that this improved laser imaging system can realize three-dimensional non-scanning laser imaging detection.

  4. In situ scanning tunneling microscope tip treatment device for spin polarization imaging

    Science.gov (United States)

    Li, An-Ping [Oak Ridge, TN; Jianxing, Ma [Oak Ridge, TN; Shen, Jian [Knoxville, TN

    2008-04-22

    A tip treatment device for use in an ultrahigh vacuum in situ scanning tunneling microscope (STM). The device provides spin polarization functionality to new or existing variable temperature STM systems. The tip treatment device readily converts a conventional STM to a spin-polarized tip, and thereby converts a standard STM system into a spin-polarized STM system. The tip treatment device also has functions of tip cleaning and tip flashing a STM tip to high temperature (>2000.degree. C.) in an extremely localized fashion. Tip coating functions can also be carried out, providing the tip sharp end with monolayers of coating materials including magnetic films. The device is also fully compatible with ultrahigh vacuum sample transfer setups.

  5. High-resolution imaging of magnetic fields using scanning superconducting quantum interference device (SQUID) microscopy

    Science.gov (United States)

    Fong de Los Santos, Luis E.

    Development of a scanning superconducting quantum interference device (SQUID) microscope system with interchangeable sensor configurations for imaging magnetic fields of room-temperature (RT) samples with sub-millimeter resolution. The low-critical-temperature (Tc) niobium-based monolithic SQUID sensor is mounted in the tip of a sapphire rod and thermally anchored to the cryostat helium reservoir. A 25 mum sapphire window separates the vacuum space from the RT sample. A positioning mechanism allows adjusting the sample-to-sensor spacing from the top of the Dewar. I have achieved a sensor-to-sample spacing of 100 mum, which could be maintained for periods of up to 4 weeks. Different SQUID sensor configurations are necessary to achieve the best combination of spatial resolution and field sensitivity for a given magnetic source. For imaging thin sections of geological samples, I used a custom-designed monolithic low-Tc niobium bare SQUID sensor, with an effective diameter of 80 mum, and achieved a field sensitivity of 1.5 pT/Hz1/2 and a magnetic moment sensitivity of 5.4 x 10-18 Am2/Hz1/2 at a sensor-to-sample spacing of 100 mum in the white noise region for frequencies above 100 Hz. Imaging action currents in cardiac tissue requires higher field sensitivity, which can only be achieved by compromising spatial resolution. I developed a monolithic low-Tc niobium multiloop SQUID sensor, with sensor sizes ranging from 250 mum to 1 mm, and achieved sensitivities of 480 - 180 fT/Hz1/2 in the white noise region for frequencies above 100 Hz, respectively. For all sensor configurations, the spatial resolution was comparable to the effective diameter and limited by the sensor-to-sample spacing. Spatial registration allowed us to compare high-resolution images of magnetic fields associated with action currents and optical recordings of transmembrane potentials to study the bidomain nature of cardiac tissue or to match petrography to magnetic field maps in thin sections of

  6. Scanning device for a spectrometer

    International Nuclear Information System (INIS)

    Ignat'ev, V.M.

    1982-01-01

    The invention belongs to scanning devices and is intended for spectrum scanning in spectral devices. The purpose of the invention is broadening of spectral scanning range. The device construction ensures the spectrum scanning range determined from revolution fractions to several revolutions of the monochromator drum head, any number of the drum head revolutions determined by integral number with addition of the drum revolution fractions with high degree of accuracy being possible

  7. Scanning device for scintigraphy

    International Nuclear Information System (INIS)

    Casale, R.

    1975-01-01

    A device is described for the scintigraphic scanning according to a horizontal plane, comprising: (a) A support provided with two guides horizontally and longitudinally located, one of which is located in the upper part of the support, while the second guide is located in the lower part of the support; (b) A carriage, movable with respect to the support along the two guides, provided in its upper part, projecting above the support, with rolling means suitable to support and to cause to slide along its axis a support rod for the first detector, horizontally and transversely located, said carriage being further provided in its lower part with a recess with possible rolling means suitable to support and to cause to slide along its axis a second support rod for the second detector, said second rod being located parallel to the first rod and below it; (c) One or two support rods for the detectors, the first of said rods being supported above the support in a sliding way along its axis, by the rolling means located in the upper part of the carriage, and the second rod if present is supported slidingly along its axis by the possible rolling means contained in the suitable recess which is provided in the lower part of the carriage, and (d) A vertical shaft supported by said carriage on which is mounted a toothed wheel for each rod, each toothed wheel engaging a positive drive belt or the like, which is connected to each said rod so that rotation of the shaft determines the simultaneous displacement of the two rods along their axes; and single motor means for driving said shaft during a scanning operation. (U.S.)

  8. Element distribution imaging in rat kidney using a 2 D rapid scan EDXRF device

    Energy Technology Data Exchange (ETDEWEB)

    Figueroa, R. G. [Universidad de la Frontera, Departamento de Ciencias Fisicas, Av. Francisco Salazar 1145, Temuco 4811230, Araucania (Chile); Lozano, E. [Instituto Nacional del Cancer, Unidad de Fisica Medica, Av. Profesor Zanartu 1010, Santiago (Chile); Bongiovanni, G., E-mail: figueror@ufro.cl [IDEPA-CONICET, Instituto Multidisciplinario de Investigacion y Desarrollo de la Patagonia Norte, Buenos Aires 1400, 8300 Neuquen (Argentina)

    2013-08-01

    Visualization of elemental distributions of biological tissue is gaining importance in many disciplines of biological, forensic and medical research. Furthermore, the maps of elements have wide application in archaeology for the understanding of the pigments, modes of preservation and environmental context. Since major advances in relation to collimators and detectors have yielded micro scale images, the chemical mapping via synchrotron scanning micro-X-ray fluorescence spectrometry (SR-{mu}X RF) is widely used as microanalytical techniques. However, the acquisition time is a limitation of current SR-{mu}X RF imaging protocols, doing tedious micro analysis of samples of more than 1 cm and very difficult to study of larger samples such as animal organ, whole organisms, work or art, etc. Recently we have developed a robotic system to image the chemistry of large specimens rapidly ar concentration levels of parts per million. Multiple images of distribution of elements can be obtained on surfaces of 100 x 100 mm and a spatial resolution of up to 0.2 mm{sup 2} per pixel, with a spectral capture time up to 1 ms per point. This system has proven to be highly efficient for the X RF mapping of elements in large biological samples, achieving comparable s results to those obtained by SR-{mu}X RF. Thus, images of As and Cu accumulation in renal cortex of arsenic-exposed rats were obtained by both methodologies. However, the new imaging system enables the X RF scanning in few minutes, whereas SR-{mu}X RF required several hours. These and other advantages as well as the potential applications of this system, will be discussed. (Author)

  9. Effect of post crosslinking haze on the repeatability of Scheimpflug-based and slit-scanning imaging devices

    Directory of Open Access Journals (Sweden)

    Rohit Shetty

    2017-01-01

    Full Text Available Purpose: The aim of this study was to analyze the effect of postcollagen crosslinking (CXL haze on the measurement and repeatability of pachymetry and mean keratometry (Km of four corneal topographers. Materials and Methods: Sixty eyes of sixty patients with progressive keratoconus who had undergone accelerated CXL (ACXL underwent imaging with a scanning slit imaging device (Orbscan II and three Scheimpflug imaging devices (Pentacam HR, Sirius, and Galilei. Post-ACXL haze was measured using the densitometry software on the Pentacam HR. Readings of the thinnest corneal thickness (TCT and Km from three scans of each device were analyzed. Effect of haze on the repeatability of TCT and Km measurements was evaluated using regression models. Repeatability was assessed by coefficient of variation. Results: Corneal densitometry in different zones affected the repeatability of TCT measurement of Orbscan (P < 0.05 significantly but not the repeatability of TCT with Pentacam HR and Sirius (P = 0.03 and 0.05, respectively. Km values were affected by haze when measured with the Pentacam HR (P < 0.05. The repeatability of Km readings for all devices was unaffected by haze. In the anterior 0–2 mm and 2–6 mm zone, TCT (P = 0.43 and 0.45, respectively, Km values (P = 0.4 and 0.6, respectively, repeatability of TCT (P = 0.1 in both zones, and Km (P = 0.5 and 0.1, respectively with Galilei were found to be the most reliable. Conclusion: Galilei measurements appear to be least affected by post-ACXL haze when compared with other devices. Hence, topography measurements in the presence of haze need to be interpreted with caution.

  10. Study on the dose response characteristics of a scanning liquid ion-chamber electronic portal imaging device

    CERN Document Server

    Ma Shao Gang; Song Yi Xin

    2002-01-01

    Objective: To study the dose response characteristics and the influence factors such as gantry angle, field size and acquisition mode on the dosimetric response curves, when using a scanning liquid ion-chamber electronic portal imaging device (EPID) for dose verification. Methods: All experiments were carried out on a Varian 600 C/D accelerator (6 MV X-ray) equipped with a Varian PortalVision sup T sup M MK2 type EPID. To obtain the dose response curve, the relationship between the incident radiation intensity to the detector and the pixel value output from the EPID were established. Firstly, the different dose rates of 6 MV X-rays were obtained by varying SSD. Secondly, three digital portal images were acquired for each dose rate using the EPID and averaged to avoid the influence of the dose rate fluctuations of the accelerator. The pixel values of all images were read using self-designed image analysis software, and and average for a region consisting of 11 x 11 pixels around the center was taken as the res...

  11. NEW SCANNING DEVICE FOR SCANNING TUNNELING MICROSCOPE APPLICATIONS

    NARCIS (Netherlands)

    SAWATZKY, GA; Koops, Karl Richard

    A small, single piezo XYZ translator has been developed. The device has been used as a scanner for a scanning tunneling microscope and has been tested successfully in air and in UHV. Its simple design results in a rigid and compact scanning unit which permits high scanning rates.

  12. Electronic portal imaging devices

    International Nuclear Information System (INIS)

    Lief, Eugene

    2008-01-01

    The topics discussed include, among others, the following: Role of portal imaging; Port films vs. EPID; Image guidance: Elekta volume view; Delivery verification; Automation tasks of portal imaging; Types of portal imaging (Fluorescent screen, mirror, and CCD camera-based imaging; Liquid ion chamber imaging; Amorpho-silicon portal imagers; Fluoroscopic portal imaging; Kodak CR reader; and Other types of portal imaging devices); QA of EPID; and Portal dosimetry (P.A.)

  13. Exabyte helical scan devices at Fermilab

    International Nuclear Information System (INIS)

    Constanta-Fanourakis, P.; Kaczar, K.; Oleynik, G.; Petravick, D.; Votava, M.; White, V.; Hockney, G.; Bracker, S.; de Miranda, J.M.

    1989-05-01

    Exabyte 8mm helical scan storage devices are in use at Fermilab in a number of applications. These devices have the functionality of magnetic tape, but use media which is much more economical and much more dense than conventional 9 track tape. 6 refs., 3 figs

  14. Scanning Tunneling Microscopy - image interpretation

    International Nuclear Information System (INIS)

    Maca, F.

    1998-01-01

    The basic ideas of image interpretation in Scanning Tunneling Microscopy are presented using simple quantum-mechanical models and supplied with examples of successful application. The importance is stressed of a correct interpretation of this brilliant experimental surface technique

  15. Linking world scan and image

    International Nuclear Information System (INIS)

    Timmer, H.; Alcamo, J.; Bollen, J.; Gielen, A.; Gerlach, R.; Den Ouden, A.; Zuidema, G.

    1995-01-01

    In march 1994 the Central Planning Bureau (CPB) in the Hague, the National Institute of Public Health and Environmental Protection (RIVM) in Bilthoven and the Institute of Environmental Studies (IES) in Amsterdam started the first phase of a joint research program aimed at creating integrated scenarios of the global economy, GHG emissions, and climate impacts. The goal of the first phase of this project was to design and test a linked version of the economic model WORLD SCAN of the former, and the climate model IMAGE 2 of the latter institute. This first phase has resulted in the planned test runs with an operational version of the linked models by May 1995. The experiences in the first year were encouraging, both in the scientific and the organizational sense. In a sense, a link was made between scientific disciplines: a coupling of disciplines concerning with global economic development and the global physical climate system is difficult and novel. The goal of the project was to integrate long-term economic developments and effects of climate change. Both the WORLD SCAN model and IMAGE 2 provide a consistent analysis of the global system, but from different perspectives. IMAGE 2 simulates climate change and its effects in a global context but treats the economic system as exogenous. WORLD SCAN covers the world economic system in a consistent manner but does not take into account the global environment. The links are constructed in the area of agriculture and energy. The basic idea is that WORLD SCAN determines demand and supply on economic principles, while IMAGE 2 provides information on changes of land area and average quality of productive land, and other damage costs based on its three sub-systems. The demand for energy is fed into IMAGE 2's Energy Industry subsystem (EIS), which in turn determines emissions of greenhouse gases. Furthermore, some additional output from WORLD SCAN on activity levels, prices and capital structure can be used to determine

  16. Scanning Terahertz Heterodyne Imaging Systems

    Science.gov (United States)

    Siegel, Peter; Dengler, Robert

    2007-01-01

    Scanning terahertz heterodyne imaging systems are now at an early stage of development. In a basic scanning terahertz heterodyne imaging system, (see Figure 1) two far-infrared lasers generate beams denoted the local-oscillator (LO) and signal that differ in frequency by an amount, denoted the intermediate frequency (IF), chosen to suit the application. The LO beam is sent directly to a mixer as one of two inputs. The signal beam is focused to a spot on or in the specimen. After transmission through or reflection from the specimen, the beams are focused to a spot on a terahertz mixer, which extracts the IF outputs. The specimen is mounted on a translation stage, by means of which the focal spot is scanned across the specimen to build up an image.

  17. Rapid-scan EPR imaging.

    Science.gov (United States)

    Eaton, Sandra S; Shi, Yilin; Woodcock, Lukas; Buchanan, Laura A; McPeak, Joseph; Quine, Richard W; Rinard, George A; Epel, Boris; Halpern, Howard J; Eaton, Gareth R

    2017-07-01

    In rapid-scan EPR the magnetic field or frequency is repeatedly scanned through the spectrum at rates that are much faster than in conventional continuous wave EPR. The signal is directly-detected with a mixer at the source frequency. Rapid-scan EPR is particularly advantageous when the scan rate through resonance is fast relative to electron spin relaxation rates. In such scans, there may be oscillations on the trailing edge of the spectrum. These oscillations can be removed by mathematical deconvolution to recover the slow-scan absorption spectrum. In cases of inhomogeneous broadening, the oscillations may interfere destructively to the extent that they are not visible. The deconvolution can be used even when it is not required, so spectra can be obtained in which some portions of the spectrum are in the rapid-scan regime and some are not. The technology developed for rapid-scan EPR can be applied generally so long as spectra are obtained in the linear response region. The detection of the full spectrum in each scan, the ability to use higher microwave power without saturation, and the noise filtering inherent in coherent averaging results in substantial improvement in signal-to-noise relative to conventional continuous wave spectroscopy, which is particularly advantageous for low-frequency EPR imaging. This overview describes the principles of rapid-scan EPR and the hardware used to generate the spectra. Examples are provided of its application to imaging of nitroxide radicals, diradicals, and spin-trapped radicals at a Larmor frequency of ca. 250MHz. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Evaluating imaging devices

    International Nuclear Information System (INIS)

    Rollo, F.D.

    1977-01-01

    The performance of any imaging device depends on two principal factors inherent to the device, namely, plane sensitivity and spatial resolution. These factors may be defined as follows: plane sensitivity is the counts per second recorded by the imaging device for each disintegration per second per square centimeter occurring within a plane sheet of radioactivity. Spatial resolution may be defined as the fidelity with which the imaging device reproduces the activity distribution of an object in the image plane. In all imaging devices, a trade-off exists between these two parameters; that is, as sensitivity improves, spatial resolution is degraded, and vice versa. Therefore, to fully evaluate an imaging system a technique should be selected that measures both parameters and reflects the trade-off between the two. In addition, the method should approximate the clinical problem, namely, the detection of a focal lesion within an activity distribution. Several methods have been described to evaluate nuclear imaging devices. The more common techniques include the use of organ phantoms, bar phantoms, line-spread functions, modulation transfer functions, contrast efficiency functions, and performance index functions. Each of these techniques is briefly described in this chapter, and their advantages and disadvantages are discussed. In addition, a phantom that can be used to simply and completely measure overall imaging system performance is described

  19. Fast-scan NMR imaging

    International Nuclear Information System (INIS)

    Iwaoka, Hideto; Matsuura, Hiroyuki; Sugiyama, Tadashi; Hirata, Takaaki

    1987-01-01

    This paper describes the Fast Recovery (FR) method for fast-scan Nuclear Magnetic Resonance imaging. The FR method uses a sequence of four radio frequency pulses - alternating selective 90 deg nutation pulses and nonselective 180 deg pulses. One free induction decay (FID) signal and one echo signal are detected and averaged to compute a 2-D image. In the modified FR method, extra 180 deg pulses are applied between 90 deg pulses to cause refocusing and the resultant spin echo signals are averaged to improve the signal to noise ratio. For the FR and modified FR sequences, the macroscopic magnetization is restored to equilibrium quickly and exactly; scan time can consequently be less than that for conventional pulse sequences, such as used in the saturation recovery method, without any penalty in signal to noise ratio. This paper derives expressions for the signal to noise ratio, scan time ratio and contrast noise ratio, compares the FR and modified FR methods with the saturation recovery method and presents experimental results for human body images. In theory and practice, the signal to noise ratio for the FR method is larger than that for the modified FR method. For a given signal to noise ratio the scan time is between one half and one fourth that for the saturation recovery method. The optimum repetition period, T r , is 0.07 ∼ 0.25 s for the FR method, and 0.1 ∼ 0.5 s for the modified FR method. Contrast noise ratio is low for high speed imaging, T r = 0.07 ∼ 0.25 s, but, high contrast noise ratio image is obtained for T r > 0.5 s. (author)

  20. Transmission environmental scanning electron microscope with scintillation gaseous detection device

    International Nuclear Information System (INIS)

    Danilatos, Gerasimos; Kollia, Mary; Dracopoulos, Vassileios

    2015-01-01

    A transmission environmental scanning electron microscope with use of a scintillation gaseous detection device has been implemented. This corresponds to a transmission scanning electron microscope but with addition of a gaseous environment acting both as environmental and detection medium. A commercial type of low vacuum machine has been employed together with appropriate modifications to the detection configuration. This involves controlled screening of various emitted signals in conjunction with a scintillation gaseous detection device already provided with the machine for regular surface imaging. Dark field and bright field imaging has been obtained along with other detection conditions. With a progressive series of modifications and tests, the theory and practice of a novel type of microscopy is briefly shown now ushering further significant improvements and developments in electron microscopy as a whole. - Highlights: • Novel scanning transmission electron microscopy (STEM) with an environmental scanning electron microscope (ESEM) called TESEM. • Use of the gaseous detection device (GDD) in scintillation mode that allows high resolution bright and dark field imaging in the TESEM. • Novel approach towards a unification of both vacuum and environmental conditions in both bulk/surface and transmission mode of electron microscopy

  1. Transmission environmental scanning electron microscope with scintillation gaseous detection device.

    Science.gov (United States)

    Danilatos, Gerasimos; Kollia, Mary; Dracopoulos, Vassileios

    2015-03-01

    A transmission environmental scanning electron microscope with use of a scintillation gaseous detection device has been implemented. This corresponds to a transmission scanning electron microscope but with addition of a gaseous environment acting both as environmental and detection medium. A commercial type of low vacuum machine has been employed together with appropriate modifications to the detection configuration. This involves controlled screening of various emitted signals in conjunction with a scintillation gaseous detection device already provided with the machine for regular surface imaging. Dark field and bright field imaging has been obtained along with other detection conditions. With a progressive series of modifications and tests, the theory and practice of a novel type of microscopy is briefly shown now ushering further significant improvements and developments in electron microscopy as a whole. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Lansce Wire Scanning Diagnostics Device Mechanical Design

    International Nuclear Information System (INIS)

    Rodriguez Esparza, Sergio; Batygin, Yuri K.; Gilpatrick, John D.; Gruchalla, Michael E.; Maestas, Alfred J.; Pillai, Chandra; Raybun, Joseph L.; Sattler, F.D.; Sedillo, James Daniel; Smith, Brian G.

    2011-01-01

    The Accelerator Operations and Technology Division at Los Alamos National Laboratory operates a linear particle accelerator which utilizes 110 wire scanning diagnostics devices to gain position and intensity information of the proton beam. In the upcoming LANSCE improvements, 51 of these wire scanners are to be replaced with a new design, up-to-date technology and off-the-shelf components. This document outlines the requirements for the mechanical design of the LANSCE wire scanner and presents the recently developed linac wire scanner prototype. Additionally, this document presents the design modifications that have been implemented into the fabrication and assembly of this first linac wire scanner prototype. Also, this document will present the design for the second, third, and fourth wire scanner prototypes being developed. Prototypes 2 and 3 belong to a different section of the particle accelerator and therefore have slightly different design specifications. Prototype 4 is a modification of a previously used wire scanner in our facility. Lastly, the paper concludes with a plan for future work on the wire scanner development.

  3. Lansce Wire Scanning Diagnostics Device Mechanical Design

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Esparza, Sergio [Los Alamos National Laboratory; Batygin, Yuri K. [Los Alamos National Laboratory; Gilpatrick, John D. [Los Alamos National Laboratory; Gruchalla, Michael E. [Los Alamos National Laboratory; Maestas, Alfred J. [Los Alamos National Laboratory; Pillai, Chandra [Los Alamos National Laboratory; Raybun, Joseph L. [Los Alamos National Laboratory; Sattler, F. D. [Los Alamos National Laboratory; Sedillo, James Daniel [Los Alamos National Laboratory; Smith, Brian G. [Los Alamos National Laboratory

    2011-01-01

    The Accelerator Operations & Technology Division at Los Alamos National Laboratory operates a linear particle accelerator which utilizes 110 wire scanning diagnostics devices to gain position and intensity information of the proton beam. In the upcoming LANSCE improvements, 51 of these wire scanners are to be replaced with a new design, up-to-date technology and off-the-shelf components. This document outlines the requirements for the mechanical design of the LANSCE wire scanner and presents the recently developed linac wire scanner prototype. Additionally, this document presents the design modifications that have been implemented into the fabrication and assembly of this first linac wire scanner prototype. Also, this document will present the design for the second, third, and fourth wire scanner prototypes being developed. Prototypes 2 and 3 belong to a different section of the particle accelerator and therefore have slightly different design specifications. Prototype 4 is a modification of a previously used wire scanner in our facility. Lastly, the paper concludes with a plan for future work on the wire scanner development.

  4. Multicolor Scanning Laser Imaging in Diabetic Retinopathy.

    Science.gov (United States)

    Ahmad, Mohammad S Z; Carrim, Zia Iqbal

    2017-11-01

    Diabetic retinopathy is a common cause of blindness in individuals younger than 60 years. Screening for retinopathy is undertaken using conventional color fundus photography and relies on the identification of hemorrhages, vascular abnormalities, exudates, and cotton-wool spots. These can sometimes be difficult to identify. Multicolor scanning laser imaging, a new imaging modality, may have a role in improving screening outcomes, as well as facilitating treatment decisions. Observational case series comprising two patients with known diabetes who were referred for further examination after color fundus photography revealed abnormal findings. Multicolor scanning laser imaging was undertaken. Features of retinal disease from each modality were compared. Multicolor scanning laser imaging provides superior visualization of retinal anatomy and pathology, thereby facilitating risk stratification and treatment decisions. Multicolor scanning laser imaging is a novel imaging technique offering the potential for improving the reliability of screening for diabetic retinopathy. Validation studies are warranted.

  5. Towards vortex imaging with scanning tunneling microscope

    International Nuclear Information System (INIS)

    Fuchs, Dan T.

    1994-02-01

    A low temperature, Besocke beetle type scanning tunneling microscope, with a scan range of 10 by 10 microns was built. The scanning tunneling microscope was calibrates for various temperatures and tested on several samples. Gold monolayers evaporated at 400 deg C were resolved and their dynamic behavior observed. Atomic resolution images of graphite were obtained. The scanning tunneling microscope was designed for future applications of vortex imaging in superconductors. The special design considerations for this application are discussed and the physics underlying it reviewed. (author)

  6. Cooling system for baby EBM scanning device

    International Nuclear Information System (INIS)

    Abd Halim Baijan; Muhammad Zahidee Taat; Abu Bakar Ghazali; Mohd Rizal Md Chulan; Rokiah Mohd Sabri; Leo Kwee Wah; Mohd Rizal Ibrahim; Lojius Lombigit; Azaman Ahmad

    2009-01-01

    Heat exchange of the scanning window of baby EBM is a critical factor for maintaining the integrity of the window material structure. As the titanium foil which was used as the scanning window, the maximum temperature accepted for the foil should be 200 degree C. This paper will discuss a simple method of Bernoulli principle to obtain the correct air blower capacity in order to reduce the heat of the scanning window of Baby EBM. It was found that the required air pressure and air speed of the blower are 2613.6 Pascal and 237.6 m3/h respectively for the electron accelerator of 0.14 MeV energy and 10 mA beam current. (Author)

  7. Linking IMAGE 2 and WORLD SCAN

    International Nuclear Information System (INIS)

    Gelauff, G.; Geurts, B.; Gielen, A.; Den Ouden, A.; Alcamo, J.; Gerlagh, R.

    1995-01-01

    The links between the climate model IMAGE 2 and the economic model WORLD SCAN, which are set up to obtain an integrated scenario instrument for comprehensive and consistent climate-economy scenarios, are presented and discussed. The links are made with respect to energy (in WORLD SCAN) and agriculture (in IMAGE 2), thus providing a consistent linkage with feedbacks running both ways. 2 figs., 1 tab

  8. Movable collimator for positron annihilation imaging device

    International Nuclear Information System (INIS)

    Thompson, C.J.

    1982-01-01

    A positron annihilation imaging device has two or more rings of detectors from which three or more slices through the object being scanned can be determined at once. A technique is provided for adjusting the slice widths. One slice may be imaged by all detectors in adjacent planes simultaneously, and reconstructed as if all detectors were in the same plane. The single slice facility is provided without the necessity of rotating the detector array or moving it in any way during data collection, allowing the possibility of doing physiologically gated imaging of a single slice

  9. COMPARISON OF RETINAL PATHOLOGY VISUALIZATION IN MULTISPECTRAL SCANNING LASER IMAGING.

    Science.gov (United States)

    Meshi, Amit; Lin, Tiezhu; Dans, Kunny; Chen, Kevin C; Amador, Manuel; Hasenstab, Kyle; Muftuoglu, Ilkay Kilic; Nudleman, Eric; Chao, Daniel; Bartsch, Dirk-Uwe; Freeman, William R

    2018-03-16

    To compare retinal pathology visualization in multispectral scanning laser ophthalmoscope imaging between the Spectralis and Optos devices. This retrospective cross-sectional study included 42 eyes from 30 patients with age-related macular degeneration (19 eyes), diabetic retinopathy (10 eyes), and epiretinal membrane (13 eyes). All patients underwent retinal imaging with a color fundus camera (broad-spectrum white light), the Spectralis HRA-2 system (3-color monochromatic lasers), and the Optos P200 system (2-color monochromatic lasers). The Optos image was cropped to a similar size as the Spectralis image. Seven masked graders marked retinal pathologies in each image within a 5 × 5 grid that included the macula. The average area with detected retinal pathology in all eyes was larger in the Spectralis images compared with Optos images (32.4% larger, P < 0.0001), mainly because of better visualization of epiretinal membrane and retinal hemorrhage. The average detection rate of age-related macular degeneration and diabetic retinopathy pathologies was similar across the three modalities, whereas epiretinal membrane detection rate was significantly higher in the Spectralis images. Spectralis tricolor multispectral scanning laser ophthalmoscope imaging had higher rate of pathology detection primarily because of better epiretinal membrane and retinal hemorrhage visualization compared with Optos bicolor multispectral scanning laser ophthalmoscope imaging.

  10. LANSCE wire scanning diagnostics device mechanical design

    International Nuclear Information System (INIS)

    Rodriguez Esparza, Sergio

    2010-01-01

    The Los Alamos Neutron Science Center (LANSCE) is one of the major experimental science facilities at the Los Alamos National Laboratory (LANL). The core of LANSCE's work lies in the operation of a powerful linear accelerator, which accelerates protons up to 84% the speed oflight. These protons are used for a variety of purposes, including materials testing, weapons research and isotopes production. To assist in guiding the proton beam, a series of over one hundred wire scanners are used to measure the beam profile at various locations along the half-mile length of the particle accelerator. A wire scanner is an electro-mechanical device that moves a set of wires through a particle beam and measures the secondary emissions from the resulting beam-wire interaction to obtain beam intensity information. When supplemented with data from a position sensor, this information is used to determine the cross-sectional profile of the beam. This measurement allows beam operators to adjust parameters such as acceleration, beam steering, and focus to ensure that the beam reaches its destination as effectively as possible. Some of the current wire scanners are nearly forty years old and are becoming obsolete. The problem with current wire scanners comes in the difficulty of maintenance and reliability. The designs of these wire scanners vary making it difficult to keep spare parts that would work on all designs. Also many of the components are custom built or out-dated technology and are no longer in production.

  11. LANSCE wire scanning diagnostics device mechanical design

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Esparza, Sergio [Los Alamos National Laboratory

    2010-01-01

    The Los Alamos Neutron Science Center (LANSCE) is one of the major experimental science facilities at the Los Alamos National Laboratory (LANL). The core of LANSCE's work lies in the operation of a powerful linear accelerator, which accelerates protons up to 84% the speed oflight. These protons are used for a variety of purposes, including materials testing, weapons research and isotopes production. To assist in guiding the proton beam, a series of over one hundred wire scanners are used to measure the beam profile at various locations along the half-mile length of the particle accelerator. A wire scanner is an electro-mechanical device that moves a set of wires through a particle beam and measures the secondary emissions from the resulting beam-wire interaction to obtain beam intensity information. When supplemented with data from a position sensor, this information is used to determine the cross-sectional profile of the beam. This measurement allows beam operators to adjust parameters such as acceleration, beam steering, and focus to ensure that the beam reaches its destination as effectively as possible. Some of the current wire scanners are nearly forty years old and are becoming obsolete. The problem with current wire scanners comes in the difficulty of maintenance and reliability. The designs of these wire scanners vary making it difficult to keep spare parts that would work on all designs. Also many of the components are custom built or out-dated technology and are no longer in production.

  12. Scanning laser microscope for imaging nanostructured superconductors

    International Nuclear Information System (INIS)

    Ishida, Takekazu; Arai, Kohei; Akita, Yukio; Miyanari, Mitsunori; Minami, Yusuke; Yotsuya, Tsutomu; Kato, Masaru; Satoh, Kazuo; Uno, Mayumi; Shimakage, Hisashi; Miki, Shigehito; Wang, Zhen

    2010-01-01

    The nanofabrication of superconductors yields various interesting features in superconducting properties. A variety of different imaging techniques have been developed for probing the local superconducting profiles. A scanning pulsed laser microscope has been developed by the combination of the XYZ piezo-driven stages and an optical fiber with an aspheric focusing lens. The scanning laser microscope is used to understand the position-dependent properties of a superconducting MgB 2 stripline of length 100 μm and width of 3 μm under constant bias current. Our results show that the superconducting stripline can clearly be seen in the contour image of the scanning laser microscope on the signal voltage. It is suggested from the observed image that the inhomogeneity is relevant in specifying the operating conditions such as detection efficiency of the sensor.

  13. Scanning laser microscope for imaging nanostructured superconductors

    Science.gov (United States)

    Ishida, Takekazu; Arai, Kohei; Akita, Yukio; Miyanari, Mitsunori; Minami, Yusuke; Yotsuya, Tsutomu; Kato, Masaru; Satoh, Kazuo; Uno, Mayumi; Shimakage, Hisashi; Miki, Shigehito; Wang, Zhen

    2010-10-01

    The nanofabrication of superconductors yields various interesting features in superconducting properties. A variety of different imaging techniques have been developed for probing the local superconducting profiles. A scanning pulsed laser microscope has been developed by the combination of the XYZ piezo-driven stages and an optical fiber with an aspheric focusing lens. The scanning laser microscope is used to understand the position-dependent properties of a superconducting MgB 2 stripline of length 100 μm and width of 3 μm under constant bias current. Our results show that the superconducting stripline can clearly be seen in the contour image of the scanning laser microscope on the signal voltage. It is suggested from the observed image that the inhomogeneity is relevant in specifying the operating conditions such as detection efficiency of the sensor.

  14. Colorectal cancer detection by hyperspectral imaging using fluorescence excitation scanning

    Science.gov (United States)

    Leavesley, Silas J.; Deal, Joshua; Hill, Shante; Martin, Will A.; Lall, Malvika; Lopez, Carmen; Rider, Paul F.; Rich, Thomas C.; Boudreaux, Carole W.

    2018-02-01

    Hyperspectral imaging technologies have shown great promise for biomedical applications. These techniques have been especially useful for detection of molecular events and characterization of cell, tissue, and biomaterial composition. Unfortunately, hyperspectral imaging technologies have been slow to translate to clinical devices - likely due to increased cost and complexity of the technology as well as long acquisition times often required to sample a spectral image. We have demonstrated that hyperspectral imaging approaches which scan the fluorescence excitation spectrum can provide increased signal strength and faster imaging, compared to traditional emission-scanning approaches. We have also demonstrated that excitation-scanning approaches may be able to detect spectral differences between colonic adenomas and adenocarcinomas and normal mucosa in flash-frozen tissues. Here, we report feasibility results from using excitation-scanning hyperspectral imaging to screen pairs of fresh tumoral and nontumoral colorectal tissues. Tissues were imaged using a novel hyperspectral imaging fluorescence excitation scanning microscope, sampling a wavelength range of 360-550 nm, at 5 nm increments. Image data were corrected to achieve a NIST-traceable flat spectral response. Image data were then analyzed using a range of supervised and unsupervised classification approaches within ENVI software (Harris Geospatial Solutions). Supervised classification resulted in >99% accuracy for single-patient image data, but only 64% accuracy for multi-patient classification (n=9 to date), with the drop in accuracy due to increased false-positive detection rates. Hence, initial data indicate that this approach may be a viable detection approach, but that larger patient sample sizes need to be evaluated and the effects of inter-patient variability studied.

  15. Seamless stitching of tile scan microscope images.

    Science.gov (United States)

    Legesse, F B; Chernavskaia, O; Heuke, S; Bocklitz, T; Meyer, T; Popp, J; Heintzmann, R

    2015-06-01

    For diagnostic purposes, optical imaging techniques need to obtain high-resolution images of extended biological specimens in reasonable time. The field of view of an objective lens, however, is often smaller than the sample size. To image the whole sample, laser scanning microscopes acquire tile scans that are stitched into larger mosaics. The appearance of such image mosaics is affected by visible edge artefacts that arise from various optical aberrations which manifest in grey level jumps across tile boundaries. In this contribution, a technique for stitching tiles into a seamless mosaic is presented. The stitching algorithm operates by equilibrating neighbouring edges and forcing the brightness at corners to a common value. The corrected image mosaics appear to be free from stitching artefacts and are, therefore, suited for further image analysis procedures. The contribution presents a novel method to seamlessly stitch tiles captured by a laser scanning microscope into a large mosaic. The motivation for the work is the failure of currently existing methods for stitching nonlinear, multimodal images captured by our microscopic setups. Our method eliminates the visible edge artefacts that appear between neighbouring tiles by taking into account the overall illumination differences among tiles in such mosaics. The algorithm first corrects the nonuniform brightness that exists within each of the tiles. It then compensates for grey level differences across tile boundaries by equilibrating neighbouring edges and forcing the brightness at the corners to a common value. After these artefacts have been removed further image analysis procedures can be applied on the microscopic images. Even though the solution presented here is tailored for the aforementioned specific case, it could be easily adapted to other contexts where image tiles are assembled into mosaics such as in astronomical or satellite photos. © 2015 The Authors Journal of Microscopy © 2015 Royal

  16. Demystifying autofluorescence with excitation scanning hyperspectral imaging

    Science.gov (United States)

    Deal, Joshua; Harris, Bradley; Martin, Will; Lall, Malvika; Lopez, Carmen; Rider, Paul; Boudreaux, Carole; Rich, Thomas; Leavesley, Silas J.

    2018-02-01

    Autofluorescence has historically been considered a nuisance in medical imaging. Many endogenous fluorophores, specifically, collagen, elastin, NADH, and FAD, are found throughout the human body. Diagnostically, these signals can be prohibitive since they can outcompete signals introduced for diagnostic purposes. Recent advances in hyperspectral imaging have allowed the acquisition of significantly more data in a shorter time period by scanning the excitation spectra of fluorophores. The reduced acquisition time and increased signal-to-noise ratio allow for separation of significantly more fluorophores than previously possible. Here, we propose to utilize excitation-scanning of autofluorescence to examine tissues and diagnose pathologies. Spectra of autofluorescent molecules were obtained using a custom inverted microscope (TE-2000, Nikon Instruments) with a Xe arc lamp and thin film tunable filter array (VersaChrome, Semrock, Inc.) Scans utilized excitation wavelengths from 360 nm to 550 nm in 5 nm increments. The resultant spectra were used to examine hyperspectral image stacks from various collaborative studies, including an atherosclerotic rat model and a colon cancer study. Hyperspectral images were analyzed with ENVI and custom Matlab scripts including linear spectral unmixing (LSU) and principal component analysis (PCA). Initial results suggest the ability to separate the signals of endogenous fluorophores and measure the relative concentrations of fluorophores among healthy and diseased states of similar tissues. These results suggest pathology-specific changes to endogenous fluorophores can be detected using excitationscanning hyperspectral imaging. Future work will expand the library of pure molecules and will examine more defined disease states.

  17. Near-infrared dental imaging using scanning fiber endoscope

    Science.gov (United States)

    Zhou, Yaxuan; Lee, Robert; Sadr, Alireza; Seibel, Eric J.

    2018-02-01

    Near-infrared (NIR) wavelength range of 1300-1500nm has the potential to outperform or augment other dental imaging modalities such as fluorescence imaging, owing to its lower scattering coefficient in enamel and trans- parency on stains and non-cariogenic plaque. However, cameras in this wavelength range are bulky and expensive, which lead to difficulties for in-vivo use and commercialization. Thus, we have proposed a new imaging device combining the scanning fiber endoscopy (SFE) and NIR imaging technology. The NIR SFE system has the advantage of miniature size (1.6 mm), flexible shaft, video frame rate (7Hz) and expandable wide field-of-view (60 degrees). Eleven extracted human teeth with or without occlusal caries were scanned by micro-computed X-ray tomography (micro-CT) to obtain 3D micro-CT images, which serve as the standard for comparison. NIR images in reflection mode were then taken on all the occlusal surfaces, using 1310nm super luminescent diode and 1460nm laser diode respectively. Qualitative comparison was performed between near-infrared im- ages and micro-CT images. Enamel demineralization in NIR appeared as areas of increased reflectivity, and distinguished from non-carious staining at the base of occlusal fissures or developmental defects on cusps. This preliminary work presented proof for practicability of combining NIR imaging technology with SFE for reliable and noninvasive dental imaging with miniaturization and low cost.

  18. PEPR and other CRT scanning and measuring devices

    Energy Technology Data Exchange (ETDEWEB)

    Pless, Irwin A. (Massachusetts Institute of Technology, Cambridge, MA 02139 (United States))

    1994-07-01

    This talk concentrates on the brief history of the PEPR (Precision Encoding and Pattern Recognition) scanning and measuring device.I restrict this reminiscence to just a short history of PEPR, the other various CRT scanners, a short summary of the capabilities of this scanner and some fond memories. ((orig.))

  19. PEPR and other CRT scanning and measuring devices

    International Nuclear Information System (INIS)

    Pless, Irwin A.

    1994-01-01

    This talk concentrates on the brief history of the PEPR (Precision Encoding and Pattern Recognition) scanning and measuring device.I restrict this reminiscence to just a short history of PEPR, the other various CRT scanners, a short summary of the capabilities of this scanner and some fond memories. ((orig.))

  20. Device localization and dynamic scan plane selection using a wireless MRI detector array

    Science.gov (United States)

    Riffe, Matthew J.; Yutzy, Stephen R.; Jiang, Yun; Twieg, Michael D.; Blumenthal, Colin J.; Hsu, Daniel P.; Pan, Li; Gilson, Wesley D.; Sunshine, Jeffrey L.; Flask, Christopher A.; Duerk, Jeffrey L.; Nakamoto, Dean; Gulani, Vikas; Griswold, Mark A.

    2013-01-01

    Purpose A prototype wireless guidance device using single sideband amplitude modulation (SSB) is presented for a 1.5T MRI system. Methods The device contained three fiducial markers each mounted to an independent receiver coil equipped with wireless SSB technology. Acquiring orthogonal projections of these markers determined the position and orientation of the device, which was used to define the scan plane for a subsequent image acquisition. Device localization and scan plane update required approximately 30 ms, so it could be interleaved with high temporal resolution imaging. Since the wireless device is used for localization and doesn’t require full imaging capability, the design of the SSB wireless system was simplified by allowing an asynchronous clock between the transmitter and receiver. Results When coupled to a high readout bandwidth, the error caused by the lack of a shared frequency reference was quantified to be less than one pixel (0.78 mm) in the projection acquisitions. Image-guidance with the prototype was demonstrated with a phantom where a needle was successfully guided to a target and contrast was delivered. Conclusion The feasibility of active tracking with a wireless detector array is demonstrated. Wireless arrays could be incorporated into devices to assist in image-guided procedures. PMID:23900921

  1. Synchronized control of spiral CT scan for security inspection device

    International Nuclear Information System (INIS)

    Wang Jue; Jiang Zenghui; Wang Fuquan

    2008-01-01

    In security inspection system of spiral CT, the synchronization between removing and rotating, and the scan synchronization between rotating and sampling influence quality of image reconstruction, so it is difficulty and important that how to realize synchronized scan. According to the controlling demand of multi-slice Spiral CT, the method to realize synchronized scan is given. a synchronized control system is designed, in which we use a industrial PC as the control computer, use magnetic grids as position detectors, use alternating current servo motor and roller motor as drivers respectively drive moving axis and rotating axis. This method can solve the problem of synchronized scan, and has a feasibility and value of use. (authors)

  2. Optical scanning holography based on compressive sensing using a digital micro-mirror device

    Science.gov (United States)

    A-qian, Sun; Ding-fu, Zhou; Sheng, Yuan; You-jun, Hu; Peng, Zhang; Jian-ming, Yue; xin, Zhou

    2017-02-01

    Optical scanning holography (OSH) is a distinct digital holography technique, which uses a single two-dimensional (2D) scanning process to record the hologram of a three-dimensional (3D) object. Usually, these 2D scanning processes are in the form of mechanical scanning, and the quality of recorded hologram may be affected due to the limitation of mechanical scanning accuracy and unavoidable vibration of stepper motor's start-stop. In this paper, we propose a new framework, which replaces the 2D mechanical scanning mirrors with a Digital Micro-mirror Device (DMD) to modulate the scanning light field, and we call it OSH based on Compressive Sensing (CS) using a digital micro-mirror device (CS-OSH). CS-OSH can reconstruct the hologram of an object through the use of compressive sensing theory, and then restore the image of object itself. Numerical simulation results confirm this new type OSH can get a reconstructed image with favorable visual quality even under the condition of a low sample rate.

  3. Software of the control computer of HPD scanning device

    International Nuclear Information System (INIS)

    Belyaev, A.V.; Rubtsov, V.F.; Slepnev, S.K.; Susov, Yu.I.

    1979-01-01

    Specific features of HPD measuring system are considered which are important for TPA-1001i computer programming, being the control computer of scanning device. The instruction language intended for interacting the computer with HPD electronics is given. Resident, auxiliary and test subprograms including those for interrupt handling, for monitoring, a driver for the operation with a teletype, a loader, a cross-assembler are described

  4. On the Progress of Scanning Transmission Electron Microscopy (STEM) Imaging in a Scanning Electron Microscope.

    Science.gov (United States)

    Sun, Cheng; Müller, Erich; Meffert, Matthias; Gerthsen, Dagmar

    2018-04-01

    Transmission electron microscopy (TEM) with low-energy electrons has been recognized as an important addition to the family of electron microscopies as it may avoid knock-on damage and increase the contrast of weakly scattering objects. Scanning electron microscopes (SEMs) are well suited for low-energy electron microscopy with maximum electron energies of 30 keV, but they are mainly used for topography imaging of bulk samples. Implementation of a scanning transmission electron microscopy (STEM) detector and a charge-coupled-device camera for the acquisition of on-axis transmission electron diffraction (TED) patterns, in combination with recent resolution improvements, make SEMs highly interesting for structure analysis of some electron-transparent specimens which are traditionally investigated by TEM. A new aspect is correlative SEM, STEM, and TED imaging from the same specimen region in a SEM which leads to a wealth of information. Simultaneous image acquisition gives information on surface topography, inner structure including crystal defects and qualitative material contrast. Lattice-fringe resolution is obtained in bright-field STEM imaging. The benefits of correlative SEM/STEM/TED imaging in a SEM are exemplified by structure analyses from representative sample classes such as nanoparticulates and bulk materials.

  5. Microscopy imaging device with advanced imaging properties

    Science.gov (United States)

    Ghosh, Kunal; Burns, Laurie; El Gamal, Abbas; Schnitzer, Mark J.; Cocker, Eric; Ho, Tatt Wei

    2015-11-24

    Systems, methods and devices are implemented for microscope imaging solutions. One embodiment of the present disclosure is directed toward an epifluorescence microscope. The microscope includes an image capture circuit including an array of optical sensor. An optical arrangement is configured to direct excitation light of less than about 1 mW to a target object in a field of view of that is at least 0.5 mm.sup.2 and to direct epi-fluorescence emission caused by the excitation light to the array of optical sensors. The optical arrangement and array of optical sensors are each sufficiently close to the target object to provide at least 2.5 .mu.m resolution for an image of the field of view.

  6. Evaluation of processing methods for static radioisotope scan images

    International Nuclear Information System (INIS)

    Oakberg, J.A.

    1976-12-01

    Radioisotope scanning in the field of nuclear medicine provides a method for the mapping of a radioactive drug in the human body to produce maps (images) which prove useful in detecting abnormalities in vital organs. At best, radioisotope scanning methods produce images with poor counting statistics. One solution to improving the body scan images is using dedicated small computers with appropriate software to process the scan data. Eleven methods for processing image data are compared

  7. Microwave impedance imaging on semiconductor memory devices

    Science.gov (United States)

    Kundhikanjana, Worasom; Lai, Keji; Yang, Yongliang; Kelly, Michael; Shen, Zhi-Xun

    2011-03-01

    Microwave impedance microscopy (MIM) maps out the real and imaginary components of the tip-sample impedance, from which the local conductivity and dielectric constant distribution can be derived. The stray field contribution is minimized in our shielded cantilever design, enabling quantitative analysis of nano-materials and device structures. We demonstrate here that the MIM can spatially resolve the conductivity variation in a dynamic random access memory (DRAM) sample. With DC or low-frequency AC bias applied to the tip, contrast between n-doped and p-doped regions in the dC/dV images is observed, and p-n junctions are highlighted in the dR/dV images. The results can be directly compared with data taken by scanning capacitance microscope (SCM), which uses unshielded cantilevers and resonant electronics, and the MIM reveals more information of the local dopant concentration than SCM.

  8. Imaging properties and its improvements of scanning/imaging x-ray microscope

    International Nuclear Information System (INIS)

    Takeuchi, Akihisa; Uesugi, Kentaro; Suzuki, Yoshio

    2016-01-01

    A scanning / imaging X-ray microscope (SIXM) system has been developed at SPring-8. The SIXM consists of a scanning X-ray microscope with a one-dimensional (1D) X-ray focusing device and an imaging (full-field) X-ray microscope with a 1D X-ray objective. The motivation of the SIXM system is to realize a quantitative and highly-sensitive multimodal 3D X-ray tomography by taking advantages of both the scanning X-ray microscope using multi-pixel detector and the imaging X-ray microscope. Data acquisition process of a 2D image is completely different between in the horizontal direction and in the vertical direction; a 1D signal is obtained with the linear-scanning while the other dimensional signal is obtained with the imaging optics. Such condition have caused a serious problem on the imaging properties that the imaging quality in the vertical direction has been much worse than that in the horizontal direction. In this paper, two approaches to solve this problem will be presented. One is introducing a Fourier transform method for phase retrieval from one phase derivative image, and the other to develop and employ a 1D diffuser to produce an asymmetrical coherent illumination

  9. Method for Surface Scanning in Medical Imaging and Related Apparatus

    DEFF Research Database (Denmark)

    2015-01-01

    A method and apparatus for surface scanning in medical imaging is provided. The surface scanning apparatus comprises an image source, a first optical fiber bundle comprising first optical fibers having proximal ends and distal ends, and a first optical coupler for coupling an image from the image...

  10. High-speed automated NDT device for niobium plate using scanning laser acoustic microscopy

    International Nuclear Information System (INIS)

    Oravecz, M.G.; Yu, B.Y.; Riney, K.; Kessler, L.W.; Padamsee, H.

    1988-01-01

    This paper presents a nondestructive testing (NDT) device which rapidly and automatically identifies defects throughout the volume of a 23.4 cm x 23.4 cm x 0.3 cm, pure niobium plate using Scanning Laser Acoustic Microscope (SLAM), high-resolution, 60 MHz, ultrasonic images. A principle advantage of the SLAM technique is that it combines a video scan rate with a high scan density (130 lines/mm at 60 MHz). To automate the inspection system they integrated under computer control the following: the SLAM RS-170/330 video output, a computerized XY plate scanner, a real-time video digitizer/integrator, a computer algorithm for defect detection, a digital mass storage device, and a hardcopy output device. The key element was development of an efficient, reliable defect detection algorithm using a variance filter with a locally determined threshold. This algorithm is responsible for recognizing valid flaws in the midst of random texture. This texture was seen throughout the acoustic images and was caused by the niobium microstructure. The images, as analyzed, contained 128 x 120 pixels with 64 grey levels per pixel. This system allows economical inspection of the large quantities (eg. 100 tons) of material needed for future particle accelerators based on microwave superconductivity. Rapid nondestructive inspection of pure niobium sheet is required because current accelerator performance is largely limited by the quality of commercially available material. Previous work documented critical flaws that are detectable by SLAM techniques. 15 references, 9 figures

  11. Scanned Image Projection System Employing Intermediate Image Plane

    Science.gov (United States)

    DeJong, Christian Dean (Inventor); Hudman, Joshua M. (Inventor)

    2014-01-01

    In imaging system, a spatial light modulator is configured to produce images by scanning a plurality light beams. A first optical element is configured to cause the plurality of light beams to converge along an optical path defined between the first optical element and the spatial light modulator. A second optical element is disposed between the spatial light modulator and a waveguide. The first optical element and the spatial light modulator are arranged such that an image plane is created between the spatial light modulator and the second optical element. The second optical element is configured to collect the diverging light from the image plane and collimate it. The second optical element then delivers the collimated light to a pupil at an input of the waveguide.

  12. [Electronic Device for Retinal and Iris Imaging].

    Science.gov (United States)

    Drahanský, M; Kolář, R; Mňuk, T

    This paper describes design and construction of a new device for automatic capturing of eye retina and iris. This device has two possible ways of utilization - either for biometric purposes (persons recognition on the base of their eye characteristics) or for medical purposes as supporting diagnostic device. eye retina, eye iris, device, acquisition, image.

  13. Improved rectilinear scanning device for the whole body

    International Nuclear Information System (INIS)

    Berninger, W.H.

    1975-01-01

    A rectilinear scanning device for whole-body counting is described in which the spacial resolution is considerably improved upon by using photomultipliers with spherically curved photocathodes. By this measure, the distinct non-linearity between the output signals of the phototubes and the actual position of the scintillation in the scintillation crystal, as observed in plane photocathodes, is removed. The distances between the photomultipliers and the scintillation crystal can thus be kept very small whereby an improved statistic and lower noise can be obtained. Furthermore, thicker crystals can be used whereby the efficiency in the determination of higher energies is increased. The electronic signal processing to the reproduction of the nuclide distribution in the body is described in detail. (ORU/LH) [de

  14. A modeling of fuzzy logic controller on gamma scanning device

    International Nuclear Information System (INIS)

    Arjoni Amir

    2010-01-01

    Modeling and simulation of controller to set the high position and direction of the source of gamma radiation isotope Co-60 and Nal(TL) detector of gamma scanning device by using fuzzy logic controller FLC have been done. The high positions and in the right direction of gamma radiation and Nal (TI) detector obtained the optimal enumeration. The counting data obtained from gamma scanning device counting system is affected by the instability of high position and direction of the gamma radiation source and Nal(TI) detector or the height and direction are not equal between the gamma radiation source and Nal(TI) detector. Assumed a high position and direction of radiation sources can be fixed while the high position detector h (2, 1,0, -1, -2) can be adjusted up and down and the detector can be changed direction to the left or right angle ω (2, 1 , 0, -1, -2) when the position and direction are no longer aligned with the direction of the source of gamma radiation, the counting results obtained will not be optimal. Movement detector direction towards the left or right and the high detector arranged by the DC motor using fuzzy logic control in order to obtain the amount of output fuzzy logic control which forms the optimal output quantity count. The variation of height difference h between the source position of the gamma radiation detector and change direction with the detector angle ω becomes the input variable membership function (member function) whereas the fuzzy logic for the output variable membership function of fuzzy logic control output is selected scale fuzzy logic is directly proportional to the amount of optimal counting. From the simulation results obtained by the relationship between the amount of data output variable of fuzzy logic controller and the amount of data input variable height h and direction detector ω is depicted in graphical form surface. (author)

  15. Categorisation of full waveform data provided by laser scanning devices

    Science.gov (United States)

    Ullrich, Andreas; Pfennigbauer, Martin

    2011-11-01

    In 2004, a laser scanner device for commercial airborne laser scanning applications, the RIEGL LMS-Q560, was introduced to the market, making use of a radical alternative approach to the traditional analogue signal detection and processing schemes found in LIDAR instruments so far: digitizing the echo signals received by the instrument for every laser pulse and analysing these echo signals off-line in a so-called full waveform analysis in order to retrieve almost all information contained in the echo signal using transparent algorithms adaptable to specific applications. In the field of laser scanning the somewhat unspecific term "full waveform data" has since been established. We attempt a categorisation of the different types of the full waveform data found in the market. We discuss the challenges in echo digitization and waveform analysis from an instrument designer's point of view and we will address the benefits to be gained by using this technique, especially with respect to the so-called multi-target capability of pulsed time-of-flight LIDAR instruments.

  16. Image mosaicing for automated pipe scanning

    International Nuclear Information System (INIS)

    Summan, Rahul; Dobie, Gordon; Guarato, Francesco; MacLeod, Charles; Marshall, Stephen; Pierce, Gareth; Forrester, Cailean; Bolton, Gary

    2015-01-01

    Remote visual inspection (RVI) is critical for the inspection of the interior condition of pipelines particularly in the nuclear and oil and gas industries. Conventional RVI equipment produces a video which is analysed online by a trained inspector employing expert knowledge. Due to the potentially disorientating nature of the footage, this is a time intensive and difficult activity. In this paper a new probe for such visual inspections is presented. The device employs a catadioptric lens coupled with feature based structure from motion to create a 3D model of the interior surface of a pipeline. Reliance upon the availability of image features is mitigated through orientation and distance estimates from an inertial measurement unit and encoder respectively. Such a model affords a global view of the data thus permitting a greater appreciation of the nature and extent of defects. Furthermore, the technique estimates the 3D position and orientation of the probe thus providing information to direct remedial action. Results are presented for both synthetic and real pipe sections. The former enables the accuracy of the generated model to be assessed while the latter demonstrates the efficacy of the technique in a practice

  17. Image mosaicing for automated pipe scanning

    Energy Technology Data Exchange (ETDEWEB)

    Summan, Rahul, E-mail: rahul.summan@strath.ac.uk; Dobie, Gordon, E-mail: rahul.summan@strath.ac.uk; Guarato, Francesco, E-mail: rahul.summan@strath.ac.uk; MacLeod, Charles, E-mail: rahul.summan@strath.ac.uk; Marshall, Stephen, E-mail: rahul.summan@strath.ac.uk; Pierce, Gareth [Department of Electronic and Electrical Engineering, University of Strathclyde, Glasgow, G1 1XW (United Kingdom); Forrester, Cailean [Inspectahire Instrument Company Ltd, Units 10 -12 Whitemyres Business Centre, Whitemyres Avenue, Aberdeen, AB16 6HQ (United Kingdom); Bolton, Gary [National Nuclear Laboratory, Chadwick House, Warrington Road, Birchwood Park, Warrington, WA3 6AE (United Kingdom)

    2015-03-31

    Remote visual inspection (RVI) is critical for the inspection of the interior condition of pipelines particularly in the nuclear and oil and gas industries. Conventional RVI equipment produces a video which is analysed online by a trained inspector employing expert knowledge. Due to the potentially disorientating nature of the footage, this is a time intensive and difficult activity. In this paper a new probe for such visual inspections is presented. The device employs a catadioptric lens coupled with feature based structure from motion to create a 3D model of the interior surface of a pipeline. Reliance upon the availability of image features is mitigated through orientation and distance estimates from an inertial measurement unit and encoder respectively. Such a model affords a global view of the data thus permitting a greater appreciation of the nature and extent of defects. Furthermore, the technique estimates the 3D position and orientation of the probe thus providing information to direct remedial action. Results are presented for both synthetic and real pipe sections. The former enables the accuracy of the generated model to be assessed while the latter demonstrates the efficacy of the technique in a practice.

  18. Image-scanning measurement using video dissection cameras

    International Nuclear Information System (INIS)

    Carson, J.S.

    1978-01-01

    A high speed dimensional measuring system capable of scanning a thin film network, and determining if there are conductor widths, resistor widths, or spaces not typical of the design for this product is described. The eye of the system is a conventional TV camera, although such devices as image dissector cameras or solid-state scanners may be used more often in the future. The analog signal from the TV camera is digitized for processing by the computer and is presented to the TV monitor to assist the operator in monitoring the system's operation. Movable stages are required when the field of view of the scanner is less than the size of the object. A minicomputer controls the movement of the stage, and communicates with the digitizer to select picture points that are to be processed. Communications with the system are maintained through a teletype or CRT terminal

  19. Use of mobile devices for medical imaging.

    Science.gov (United States)

    Hirschorn, David S; Choudhri, Asim F; Shih, George; Kim, Woojin

    2014-12-01

    Mobile devices have fundamentally changed personal computing, with many people forgoing the desktop and even laptop computer altogether in favor of a smaller, lighter, and cheaper device with a touch screen. Doctors and patients are beginning to expect medical images to be available on these devices for consultative viewing, if not actual diagnosis. However, this raises serious concerns with regard to the ability of existing mobile devices and networks to quickly and securely move these images. Medical images often come in large sets, which can bog down a network if not conveyed in an intelligent manner, and downloaded data on a mobile device are highly vulnerable to a breach of patient confidentiality should that device become lost or stolen. Some degree of regulation is needed to ensure that the software used to view these images allows all relevant medical information to be visible and manipulated in a clinically acceptable manner. There also needs to be a quality control mechanism to ensure that a device's display accurately conveys the image content without loss of contrast detail. Furthermore, not all mobile displays are appropriate for all types of images. The smaller displays of smart phones, for example, are not well suited for viewing entire chest radiographs, no matter how small and numerous the pixels of the display may be. All of these factors should be taken into account when deciding where, when, and how to use mobile devices for the display of medical images. Copyright © 2014 American College of Radiology. Published by Elsevier Inc. All rights reserved.

  20. Transverse scan-field imaging apparatus

    International Nuclear Information System (INIS)

    Lyons, F.T.

    1978-01-01

    A description is given of an array of opposed pairs of radiation detectors which could be used in tomography or scintiscanning. The opposed detectors scan in opposite tangential directions in a pre-programmed fashion. The associated control system receives the detector outputs into a buffer store and also provides an address for each element of information detected. The addresses are such that information from one buffer store is read into the RAM of a central processing unit in the opposite direction to that from the store associated with the opposite detector, thus effectively reversing the scan direction of one detector of each pair. Also described are the detectors themselves with focussed collimators, the scan drive mechanism, and the method of calculating radioactive emission intensity at discrete points throughout the scan-field. (author)

  1. Are Portable Stereophotogrammetric Devices Reliable in Facial Imaging? A Validation Study of VECTRA H1 Device.

    Science.gov (United States)

    Gibelli, Daniele; Pucciarelli, Valentina; Cappella, Annalisa; Dolci, Claudia; Sforza, Chiarella

    2018-01-31

    Modern 3-dimensional (3D) image acquisition systems represent a crucial technologic development in facial anatomy because of their accuracy and precision. The recently introduced portable devices can improve facial databases by increasing the number of applications. In the present study, the VECTRA H1 portable stereophotogrammetric device was validated to verify its applicability to 3D facial analysis. Fifty volunteers underwent 4 facial scans using portable VECTRA H1 and static VECTRA M3 devices (2 for each instrument). Repeatability of linear, angular, surface area, and volume measurements was verified within the device and between devices using the Bland-Altman test and the calculation of absolute and relative technical errors of measurement (TEM and rTEM, respectively). In addition, the 2 scans obtained by the same device and the 2 scans obtained by different devices were registered and superimposed to calculate the root mean square (RMS; point-to-point) distance between the 2 surfaces. Most linear, angular, and surface area measurements had high repeatability in M3 versus M3, H1 versus H1, and M3 versus H1 comparisons (range, 82.2 to 98.7%; TEM range, 0.3 to 2.0 mm, 0.4° to 1.8°; rTEM range, 0.2 to 3.1%). In contrast, volumes and RMS distances showed evident differences in M3 versus M3 and H1 versus H1 comparisons and reached the maximum when scans from the 2 different devices were compared. The portable VECTRA H1 device proved reliable for assessing linear measurements, angles, and surface areas; conversely, the influence of involuntary facial movements on volumes and RMS distances was more important compared with the static device. Copyright © 2018 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  2. Optimal alignment of mirror based pentaprisms for scanning deflectometric devices

    Energy Technology Data Exchange (ETDEWEB)

    Barber, Samuel K.; Geckeler, Ralf D.; Yashchuk, Valeriy V.; Gubarev, Mikhail V.; Buchheim, Jana; Siewert, Frank; Zeschke, Thomas

    2011-03-04

    In the recent work [Proc. of SPIE 7801, 7801-2/1-12 (2010), Opt. Eng. 50(5) (2011), in press], we have reported on improvement of the Developmental Long Trace Profiler (DLTP), a slope measuring profiler available at the Advanced Light Source Optical Metrology Laboratory, achieved by replacing the bulk pentaprism with a mirror based pentaprism (MBPP). An original experimental procedure for optimal mutual alignment of the MBPP mirrors has been suggested and verified with numerical ray tracing simulations. It has been experimentally shown that the optimally aligned MBPP allows the elimination of systematic errors introduced by inhomogeneity of the optical material and fabrication imperfections of the bulk pentaprism. In the present article, we provide the analytical derivation and verification of easily executed optimal alignment algorithms for two different designs of mirror based pentaprisms. We also provide an analytical description for the mechanism for reduction of the systematic errors introduced by a typical high quality bulk pentaprism. It is also shown that residual misalignments of an MBPP introduce entirely negligible systematic errors in surface slope measurements with scanning deflectometric devices.

  3. Fundamental studies of superconductors using scanning magnetic imaging

    Science.gov (United States)

    Kirtley, J. R.

    2010-12-01

    In this review I discuss the application of scanning magnetic imaging to fundamental studies of superconductors, concentrating on three scanning magnetic microscopies—scanning SQUID microscopy (SSM), scanning Hall bar microscopy (SHM) and magnetic force microscopy (MFM). I briefly discuss the history, sensitivity, spatial resolution, invasiveness and potential future developments of each technique. I then discuss a selection of applications of these microscopies. I start with static imaging of magnetic flux: an SSM study provides deeper understanding of vortex trapping in narrow strips, which are used to reduce noise in superconducting circuitry. Studies of vortex trapping in wire lattices, clusters and arrays of rings and nanoholes show fascinating ordering effects. The cuprate high-Tc superconductors are shown to have predominantly d-wave pairing symmetry by magnetic imaging of the half-integer flux quantum effect. Arrays of superconducting rings act as a physical analog for the Ising spin model, with the half-integer flux quantum effect helping to eliminate one source of disorder in antiferromagnetic arrangements of the ring moments. Tests of the interlayer tunneling model show that the condensation energy available from this mechanism cannot account for the high critical temperatures observed in the cuprates. The strong divergence in the magnetic fields of Pearl vortices allows them to be imaged using SSM, even for penetration depths of a millimeter. Unusual vortex arrangements occur in samples comparable in size to the coherence length. Spontaneous magnetization is not observed in Sr2RuO4, which is believed to have px ± ipy pairing symmetry, although effects hundreds of times bigger than the sensitivity limits had been predicted. However, unusual flux trapping is observed in this superconductor. Finally, unusual flux arrangements are also observed in magnetic superconductors. I then turn to vortex dynamics: imaging of vortices in rings of highly underdoped

  4. Fundamental studies of superconductors using scanning magnetic imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kirtley, J R [Center for Probing the Nanoscale, Stanford University, Stanford, CA (United States)

    2010-12-01

    In this review I discuss the application of scanning magnetic imaging to fundamental studies of superconductors, concentrating on three scanning magnetic microscopies-scanning SQUID microscopy (SSM), scanning Hall bar microscopy (SHM) and magnetic force microscopy (MFM). I briefly discuss the history, sensitivity, spatial resolution, invasiveness and potential future developments of each technique. I then discuss a selection of applications of these microscopies. I start with static imaging of magnetic flux: an SSM study provides deeper understanding of vortex trapping in narrow strips, which are used to reduce noise in superconducting circuitry. Studies of vortex trapping in wire lattices, clusters and arrays of rings and nanoholes show fascinating ordering effects. The cuprate high-T{sub c} superconductors are shown to have predominantly d-wave pairing symmetry by magnetic imaging of the half-integer flux quantum effect. Arrays of superconducting rings act as a physical analog for the Ising spin model, with the half-integer flux quantum effect helping to eliminate one source of disorder in antiferromagnetic arrangements of the ring moments. Tests of the interlayer tunneling model show that the condensation energy available from this mechanism cannot account for the high critical temperatures observed in the cuprates. The strong divergence in the magnetic fields of Pearl vortices allows them to be imaged using SSM, even for penetration depths of a millimeter. Unusual vortex arrangements occur in samples comparable in size to the coherence length. Spontaneous magnetization is not observed in Sr{sub 2}RuO{sub 4}, which is believed to have p{sub x} {+-} ip{sub y} pairing symmetry, although effects hundreds of times bigger than the sensitivity limits had been predicted. However, unusual flux trapping is observed in this superconductor. Finally, unusual flux arrangements are also observed in magnetic superconductors. I then turn to vortex dynamics: imaging of vortices

  5. Dual scan CT image recovery from truncated projections

    Science.gov (United States)

    Sarkar, Shubhabrata; Wahi, Pankaj; Munshi, Prabhat

    2017-12-01

    There are computerized tomography (CT) scanners available commercially for imaging small objects and they are often categorized as mini-CT X-ray machines. One major limitation of these machines is their inability to scan large objects with good image quality because of the truncation of projection data. An algorithm is proposed in this work which enables such machines to scan large objects while maintaining the quality of the recovered image.

  6. 21 CFR 892.2040 - Medical image hardcopy device.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Medical image hardcopy device. 892.2040 Section... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.2040 Medical image hardcopy device. (a) Identification. A medical image hardcopy device is a device that produces a visible printed record of a medical...

  7. A new 3-dimensional head fixation device for brain imaging

    International Nuclear Information System (INIS)

    Goto, Ryoi; Kawashima, Ryuta; Yoshioka, Seiro; Ono, Shuichi; Ito, Hiroshi; Sato, Kazunori; Akaizawa, Takashi; Koyama, Masamichi; Fukuda, Hiroshi

    1995-01-01

    We have developed a new head fixation device for studies of brain function. This device was designed to immobilize subject's heads during image scanning and to precisely reproduce the head position for two different imaging modalities such as MRI and PET. The device consists of a plastic frame, a pillow filled with beads of styrene foam, and a face mask of thermoplastic resin which was originally intended for application in radiotherapy. A bridge for biting was incorporated into the mask for stable fixation. The device enables immobilization of subject's heads with good reproducibility of position at the practical level. Our results indicate that this head fixation system is useful for fixation of head during activation studies using PET. (author)

  8. Novel optical scanning cryptography using Fresnel telescope imaging.

    Science.gov (United States)

    Yan, Aimin; Sun, Jianfeng; Hu, Zhijuan; Zhang, Jingtao; Liu, Liren

    2015-07-13

    We propose a new method called modified optical scanning cryptography using Fresnel telescope imaging technique for encryption and decryption of remote objects. An image or object can be optically encrypted on the fly by Fresnel telescope scanning system together with an encryption key. For image decryption, the encrypted signals are received and processed with an optical coherent heterodyne detection system. The proposed method has strong performance through use of secure Fresnel telescope scanning with orthogonal polarized beams and efficient all-optical information processing. The validity of the proposed method is demonstrated by numerical simulations and experimental results.

  9. Characteristics of different frequency ranges in scanning electron microscope images

    International Nuclear Information System (INIS)

    Sim, K. S.; Nia, M. E.; Tan, T. L.; Tso, C. P.; Ee, C. S.

    2015-01-01

    We demonstrate a new approach to characterize the frequency range in general scanning electron microscope (SEM) images. First, pure frequency images are generated from low frequency to high frequency, and then, the magnification of each type of frequency image is implemented. By comparing the edge percentage of the SEM image to the self-generated frequency images, we can define the frequency ranges of the SEM images. Characterization of frequency ranges of SEM images benefits further processing and analysis of those SEM images, such as in noise filtering and contrast enhancement

  10. Characteristics of different frequency ranges in scanning electron microscope images

    Energy Technology Data Exchange (ETDEWEB)

    Sim, K. S., E-mail: kssim@mmu.edu.my; Nia, M. E.; Tan, T. L.; Tso, C. P.; Ee, C. S. [Faculty of Engineering and Technology, Multimedia University, 75450 Melaka (Malaysia)

    2015-07-22

    We demonstrate a new approach to characterize the frequency range in general scanning electron microscope (SEM) images. First, pure frequency images are generated from low frequency to high frequency, and then, the magnification of each type of frequency image is implemented. By comparing the edge percentage of the SEM image to the self-generated frequency images, we can define the frequency ranges of the SEM images. Characterization of frequency ranges of SEM images benefits further processing and analysis of those SEM images, such as in noise filtering and contrast enhancement.

  11. Spatial Angular Compounding Technique for H-Scan Ultrasound Imaging.

    Science.gov (United States)

    Khairalseed, Mawia; Xiong, Fangyuan; Kim, Jung-Whan; Mattrey, Robert F; Parker, Kevin J; Hoyt, Kenneth

    2018-01-01

    H-Scan is a new ultrasound imaging technique that relies on matching a model of pulse-echo formation to the mathematics of a class of Gaussian-weighted Hermite polynomials. This technique may be beneficial in the measurement of relative scatterer sizes and in cancer therapy, particularly for early response to drug treatment. Because current H-scan techniques use focused ultrasound data acquisitions, spatial resolution degrades away from the focal region and inherently affects relative scatterer size estimation. Although the resolution of ultrasound plane wave imaging can be inferior to that of traditional focused ultrasound approaches, the former exhibits a homogeneous spatial resolution throughout the image plane. The purpose of this study was to implement H-scan using plane wave imaging and investigate the impact of spatial angular compounding on H-scan image quality. Parallel convolution filters using two different Gaussian-weighted Hermite polynomials that describe ultrasound scattering events are applied to the radiofrequency data. The H-scan processing is done on each radiofrequency image plane before averaging to get the angular compounded image. The relative strength from each convolution is color-coded to represent relative scatterer size. Given results from a series of phantom materials, H-scan imaging with spatial angular compounding more accurately reflects the true scatterer size caused by reductions in the system point spread function and improved signal-to-noise ratio. Preliminary in vivo H-scan imaging of tumor-bearing animals suggests this modality may be useful for monitoring early response to chemotherapeutic treatment. Overall, H-scan imaging using ultrasound plane waves and spatial angular compounding is a promising approach for visualizing the relative size and distribution of acoustic scattering sources. Copyright © 2018 World Federation for Ultrasound in Medicine and Biology. Published by Elsevier Inc. All rights reserved.

  12. Internal scanning method as unique imaging method of optical vortex scanning microscope

    Science.gov (United States)

    Popiołek-Masajada, Agnieszka; Masajada, Jan; Szatkowski, Mateusz

    2018-06-01

    The internal scanning method is specific for the optical vortex microscope. It allows to move the vortex point inside the focused vortex beam with nanometer resolution while the whole beam stays in place. Thus the sample illuminated by the focused vortex beam can be scanned just by the vortex point. We show that this method enables high resolution imaging. The paper presents the preliminary experimental results obtained with the first basic image recovery procedure. A prospect of developing more powerful tools for topography recovery with the optical vortex scanning microscope is discussed shortly.

  13. Automated image quality assessment for chest CT scans.

    Science.gov (United States)

    Reeves, Anthony P; Xie, Yiting; Liu, Shuang

    2018-02-01

    Medical image quality needs to be maintained at standards sufficient for effective clinical reading. Automated computer analytic methods may be applied to medical images for quality assessment. For chest CT scans in a lung cancer screening context, an automated quality assessment method is presented that characterizes image noise and image intensity calibration. This is achieved by image measurements in three automatically segmented homogeneous regions of the scan: external air, trachea lumen air, and descending aorta blood. Profiles of CT scanner behavior are also computed. The method has been evaluated on both phantom and real low-dose chest CT scans and results show that repeatable noise and calibration measures may be realized by automated computer algorithms. Noise and calibration profiles show relevant differences between different scanners and protocols. Automated image quality assessment may be useful for quality control for lung cancer screening and may enable performance improvements to automated computer analysis methods. © 2017 American Association of Physicists in Medicine.

  14. A device for multimodal imaging of skin

    Science.gov (United States)

    Spigulis, Janis; Garancis, Valerijs; Rubins, Uldis; Zaharans, Eriks; Zaharans, Janis; Elste, Liene

    2013-03-01

    A compact prototype device for diagnostic imaging of skin has been developed and tested. Polarized LED light at several spectral regions is used for illumination, and round skin spot of diameter 30mm is imaged by a CMOS sensor via crossoriented polarizing filter. Four consecutive imaging series are performed: (1) RGB image at white LED illumination for revealing subcutaneous structures; (2) four spectral images at narrowband LED illumination (450nm, 540nm, 660nm, 940nm) for mapping of the main skin chromophores; (3) video-imaging under green LED illumination for mapping of skin blood perfusion; (4) autofluorescence video-imaging under UV (365nm) LED irradiation for mapping of the skin fluorophores. Design details of the device as well as preliminary results of clinical tests are presented.

  15. Transport Imaging for the Study of Quantum Scattering Phenomena in Next Generation Semiconductor Devices

    National Research Council Canada - National Science Library

    Bradley, Frank M

    2005-01-01

    ...) and highly efficient solar cells. A novel technique has been developed utilizing direct imaging of electron/hole recombination via an optical microscope and a high sensitivity charge coupled device coupled to a scanning electron...

  16. Retrospective study of renal images on whole bone scanning

    International Nuclear Information System (INIS)

    Yanagisawa, Munetoshi; Machida, Toyohei; Miki, Makoto; Ohishi, Yukihiko; Ueda, Masataka

    1978-01-01

    One hundred and twenty-seven cases were surveyed by sup(99m)Tc-pyrophosphate at Jikei hospital. Renal images on whole-bone scanning were observed in all cases; 75% of all renal images were normal and 25% were abnormal. Thirteen percent of these abnormal images were symmetric and 87% were asymmetric. Four of the symmetric renal images were bilaterally bad. Three of the four bilaterally bad renal images involved prostate carcinomas with general metastases and the last involved serious bilateral hydronephrosis. The reason for the high percentage of asymmetric renal images was that the materials involved many urogenital cases. Asymmetric renal images other than the urogenital cases, were recognised in 8% of all cases. This percentage is consistent with Hattner's report. Unilateral abnormal renal images involved 8 hydronephrosis cases, 2 unilateral nonfunctioning kidneys and one malrotation kidney. Among the hydronephrosis cases, serious cases gave low uptake and mild cases gave high uptake. The reason for this phenomenon was, presumably, that there were differences in renal uptake, renal excretion and renal pelvic accumulation. In nine cases, one kidney was not visualized on whole-bone scanning, 8 of them involved nephrectomy and the remainining one unilateral nonfunctioning kidney. Six cases presented locally abnormal renal images on whole-bone scanning, three of them suffered renal cell carcinomas and the rest renal solitary cyst. Eighty-eight percent of the abnormal renal images agreed with IVP findings. The renal images of whole-bone scanning faithfully reflected the original renal lesion. Two cases of renal carcinoma and renal solitary cyst recognized on whole-bone scanning are presented, to indicate the usefulness of renal images on whole-bone scanning. (auth.)

  17. A preprocessor for geotomographic imaging of irregular geometric scans

    International Nuclear Information System (INIS)

    Middleton, N.T.; Harman, M.T.

    1992-01-01

    Conventional tomographic image reconstruction algorithms that use algebraic methods are best suited to rectangular geometries. Although this is satisfactory for many rectangular cross-hole and in-seam geotomographic scans, difficulties arise in cases where the scanning geometry is nonrectangular. This paper describes a preprocessing algorithm that deals with nonrectangular geometries when merged with a conventional image reconstruction algorithm. The performance of the preprocessing algorithm is demonstrated with some simulation results

  18. A New Multichannel Spectral Imaging Laser Scanning Confocal Microscope

    Directory of Open Access Journals (Sweden)

    Yunhai Zhang

    2013-01-01

    Full Text Available We have developed a new multichannel spectral imaging laser scanning confocal microscope for effective detection of multiple fluorescent labeling in the research of biological tissues. In this paper, the design and key technologies of the system are introduced. Representative results on confocal imaging, 3-dimensional sectioning imaging, and spectral imaging are demonstrated. The results indicated that the system is applicable to multiple fluorescent labeling in biological experiments.

  19. The value of filtered planar images in pediatric DMSA scans

    International Nuclear Information System (INIS)

    Mohammed, A.M.; Naddaf, S.Y.; Elgazzar, A.H.; Al-Abdul Salam, A.A.; Omar, A.A.

    2006-01-01

    The study was designed to demonstrate the value of filtered planar images in paediatric DMSA scanning. One hundred and seventy three patients ranged in age from 15 days to 12 years (mean: 4.3 years) with urinary tract infection (UTI) and clinical and/or laboratory suspicion of acute pyelonephritis (APN) were retrospectively studied. Planar images were filtered using Butterworth filter. The scan findings were reported as positive, negative or equivocal for cortical defects. Each scan was read in a double-blind fashion by two nuclear medicine physicians to evaluate inter-observer variations. Each kidney was divided into three zones, upper, middle and lower, and each zone was graded as positive, negative or equivocal for the presence of renal defects. Renal cortical defects were found in 66 patients (91 kidneys and 186 zones) with filtered images, 58 patients (81 kidneys and 175 zones) with planar images, and 69 patients (87 kidneys and 180 zones) with SPECT images. McNemar's test revealed statistically significant difference between filtered and planar images (p=0.038 for patients, 0.021 for kidneys and 0.034 for number of zones). Inter-observer agreement was 0.877 for filtered images, 0.915 for planar images and 0.915 for SPECT images. It was concluded that filtered planar images of renal cortex are comparable to SPECT images and can be used effectively in place of SPECT, when required, to shorten imaging time and eliminate motion artifacts, especially in the paediatric population. (author)

  20. Scanning transmission electron microscopy imaging and analysis

    CERN Document Server

    Pennycook, Stephen J

    2011-01-01

    Provides the first comprehensive treatment of the physics and applications of this mainstream technique for imaging and analysis at the atomic level Presents applications of STEM in condensed matter physics, materials science, catalysis, and nanoscience Suitable for graduate students learning microscopy, researchers wishing to utilize STEM, as well as for specialists in other areas of microscopy Edited and written by leading researchers and practitioners

  1. Reading device of a radiation image contained in a radioluminescent screen and tomography device containing it

    International Nuclear Information System (INIS)

    Allemand, R.; Cuzin, M.; Parot, P.

    1984-01-01

    The present invention is aimed at improving the random access time to a stimulable radioluminescent screen point (and consequently the reading time of the screen image); it is noticeably useful for longitudinal tomography. The reading device contains a source emitting a stimulation radiation beam towards the stimulable radioluminescent screen, a control mean of the stimulation radiation beam and a deflection mean which allows the beam to scan the screen surface. The device is characterized by the use of a very fast acousto-optical type deflection mean [fr

  2. Scanning or treating device for smooth curved surface

    International Nuclear Information System (INIS)

    Gemma, A.

    1988-01-01

    This robot for scanning or treating a smooth curved surface is made by a vehicle moving predeterminately on the surface, this vehicle having mobil grips. A support arm is attached to the vehicle by a swivel and fixed at the center of the curvature. It is orientable parralel to the axes of legs of the vehicle near the center. Scanning or treatment systems for the surface are fixed on the vehicle. Drives and control systems for the vehicle and treatment or scanning system are provided [fr

  3. Nuclear Medicine Imaging Devices. Chapter 11

    Energy Technology Data Exchange (ETDEWEB)

    Lodge, M. A.; Frey, E. C. [Russell H. Morgan Department of Radiology and Radiological Sciences, Johns Hopkins University, Baltimore, MD (United States)

    2014-12-15

    Imaging forms an important part of nuclear medicine and a number of different imaging devices have been developed. This chapter describes the principles and technological characteristics of the main imaging devices used in nuclear medicine. The two major categories are gamma camera systems and positron emission tomography (PET) systems. The former are used to image γ rays emitted by any nuclide, while the latter exploit the directional correlation between annihilation photons emitted by positron decay. The first section of this chapter discusses the principal components of gamma cameras and how they are used to form 2-D planar images as well as 3-D tomographic images (single photon emission computed tomography (SPECT)). The second section describes related instrumentation that has been optimized for PET data acquisition. A major advance in nuclear medicine was achieved with the introduction of multi-modality imaging systems including SPECT/computed tomography (CT) and PET/CT. In these systems, the CT images can be used to provide an anatomical context for the functional nuclear medicine images and allow for attenuation compensation. The third section in this chapter provides a discussion of the principles of these devices.

  4. Scanning tunneling microscopic images and scanning tunneling spectra for coupled rectangular quantum corrals

    International Nuclear Information System (INIS)

    Mitsuoka, Shigenori; Tamura, Akira

    2011-01-01

    Assuming that an electron confined by double δ-function barriers lies in a quasi-stationary state, we derived eigenstates and eigenenergies of the electron. Such an electron has a complex eigenenergy, and the imaginary part naturally leads to the lifetime of the electron associated with tunneling through barriers. We applied this point of view to the electron confined in a rectangular quantum corral (QC) on a noble metal surface, and obtained scanning tunneling microscopic images and a scanning tunneling spectrum consistent with experimental ones. We investigated the electron states confined in coupled QCs and obtained the coupled states constructed with bonding and anti-bonding states. Using those energy levels and wavefunctions we specified scanning tunneling microscope (STM) images and scanning tunneling spectra (STS) for the doubly and triply coupled QCs. In addition we pointed out the feature of resonant electron states associated with the same QCs at both ends of the triply coupled QCs.

  5. Translate rotate scanning method for X-ray imaging

    International Nuclear Information System (INIS)

    Eberhard, J.W.; Kwog Cheong Tam.

    1990-01-01

    Rapid x-ray inspection of objects larger than an x-ray detector array is based on a translate rotate scanning motion of the object related to the fan beam source and detector. The scan for computerized tomography imaging is accomplished by rotating the object through 360 degrees at two or more positions relative to the source and detector array, in moving to another position the object is rotated and the object or source and detector are translated. A partial set of x-ray data is acquired at every position which are combined to obtain a full data set for complete image reconstruction. X-ray data for digital radiography imaging is acquired by scanning the object vertically at a first position at one view angle, rotating and translating the object relative to the source and detector to a second position, scanning vertically, and so on to cover the object field of view, and combining the partial data sets. (author)

  6. Adaptive and robust statistical methods for processing near-field scanning microwave microscopy images.

    Science.gov (United States)

    Coakley, K J; Imtiaz, A; Wallis, T M; Weber, J C; Berweger, S; Kabos, P

    2015-03-01

    Near-field scanning microwave microscopy offers great potential to facilitate characterization, development and modeling of materials. By acquiring microwave images at multiple frequencies and amplitudes (along with the other modalities) one can study material and device physics at different lateral and depth scales. Images are typically noisy and contaminated by artifacts that can vary from scan line to scan line and planar-like trends due to sample tilt errors. Here, we level images based on an estimate of a smooth 2-d trend determined with a robust implementation of a local regression method. In this robust approach, features and outliers which are not due to the trend are automatically downweighted. We denoise images with the Adaptive Weights Smoothing method. This method smooths out additive noise while preserving edge-like features in images. We demonstrate the feasibility of our methods on topography images and microwave |S11| images. For one challenging test case, we demonstrate that our method outperforms alternative methods from the scanning probe microscopy data analysis software package Gwyddion. Our methods should be useful for massive image data sets where manual selection of landmarks or image subsets by a user is impractical. Published by Elsevier B.V.

  7. Big cat scan: magnetic resonance imaging of the tiger

    International Nuclear Information System (INIS)

    Snow, Thomas M.; Gregory, Richard J.W.; Litster, Annette L.; Hanger, Jonathan J.

    2004-01-01

    In August 2002, we performed MRI scans on a female juvenile Bengal tiger. We present the clinical course, imaging and autopsy findings, and some comparative anatomy of the tiger brain and skull. Magnetic resonance images of a tiger have not previously been published Copyright (2004) Blackwell Publishing Asia Pty Ltd

  8. Intrathoracic kidney. Diagnostic value of CT scan imaging

    International Nuclear Information System (INIS)

    Baillet, A.M.; Escure, M.N.

    1988-01-01

    Two cases are reported of an ectopic right kidney that was partially intrathoracic in position. Diagnosis was simple from CT scan imaging appearances, the examination being performed to investigate an intrathoracic mass. Images showed a tissular mass within a fatty zone in sections without contrast and the typical appearance of the kidney on sections with contrast [fr

  9. Imaging of the vertical particle tracks without any depth scanning

    International Nuclear Information System (INIS)

    Soroko, L.M.

    2001-01-01

    The principle of a new optical microscope which enables us to get the image of a vertical particle track without any depth scanning is described. This new optical microscope contains a spatial transformer which consists of mirror lamellar elements and which produces a secondary in focus image of the vertical particle track. Properties of such a system are presented. A longitudinal resolution is estimated

  10. Electronic structure classifications using scanning tunneling microscopy conductance imaging

    International Nuclear Information System (INIS)

    Horn, K.M.; Swartzentruber, B.S.; Osbourn, G.C.; Bouchard, A.; Bartholomew, J.W.

    1998-01-01

    The electronic structure of atomic surfaces is imaged by applying multivariate image classification techniques to multibias conductance data measured using scanning tunneling microscopy. Image pixels are grouped into classes according to shared conductance characteristics. The image pixels, when color coded by class, produce an image that chemically distinguishes surface electronic features over the entire area of a multibias conductance image. Such open-quotes classedclose quotes images reveal surface features not always evident in a topograph. This article describes the experimental technique used to record multibias conductance images, how image pixels are grouped in a mathematical, classification space, how a computed grouping algorithm can be employed to group pixels with similar conductance characteristics in any number of dimensions, and finally how the quality of the resulting classed images can be evaluated using a computed, combinatorial analysis of the full dimensional space in which the classification is performed. copyright 1998 American Institute of Physics

  11. Content analysis of Australian direct-to-consumer websites for emerging breast cancer imaging devices.

    Science.gov (United States)

    Vreugdenburg, Thomas D; Laurence, Caroline O; Willis, Cameron D; Mundy, Linda; Hiller, Janet E

    2014-09-01

    To describe the nature and frequency of information presented on direct-to-consumer websites for emerging breast cancer imaging devices. Content analysis of Australian website advertisements from 2 March 2011 to 30 March 2012, for three emerging breast cancer imaging devices: digital infrared thermal imaging, electrical impedance scanning and electronic palpation imaging. Type of imaging offered, device safety, device performance, application of device, target population, supporting evidence and comparator tests. Thirty-nine unique Australian websites promoting a direct-to-consumer breast imaging device were identified. Despite a lack of supporting evidence, 22 websites advertised devices for diagnosis, 20 advertised devices for screening, 13 advertised devices for prevention and 13 advertised devices for identifying breast cancer risk factors. Similarly, advertised ranges of diagnostic sensitivity (78%-99%) and specificity (44%-91%) were relatively high compared with published literature. Direct comparisons with conventional screening tools that favoured the new device were highly prominent (31 websites), and one-third of websites (12) explicitly promoted their device as a suitable alternative. Australian websites for emerging breast imaging devices, which are also available internationally, promote the use of such devices as safe and effective solutions for breast cancer screening and diagnosis in a range of target populations. Many of these claims are not supported by peer-reviewed evidence, raising questions about the manner in which these devices and their advertising material are regulated, particularly when they are promoted as direct alternatives to established screening interventions.

  12. Data compression of scanned halftone images

    DEFF Research Database (Denmark)

    Forchhammer, Søren; Jensen, Kim S.

    1994-01-01

    with the halftone grid, and converted to a gray level representation. A new digital description of (halftone) grids has been developed for this purpose. The gray level values are coded according to a scheme based on states derived from a segmentation of gray values. To enable real-time processing of high resolution...... scanner output, the coding has been parallelized and implemented on a transputer system. For comparison, the test image was coded using existing (lossless) methods giving compression rates of 2-7. The best of these, a combination of predictive and binary arithmetic coding was modified and optimized...

  13. Fluorescence image excited by a scanning UV-LED light

    Science.gov (United States)

    Tsai, Hsin-Yi; Chen, Yi-Ju; Huang, Kuo-Cheng

    2013-03-01

    An optical scanning system using UV-LED light to induced fluorescence technology can enhance a fluorescence image significantly in a short period. It has several advantages such as lower power consumption, no scattering effect in skins, and multilayer images can be obtained to analyze skin disease. From the experiment results, the light intensity increases with increase spot size and decrease scanning speed, but the image resolution is oppositely. Moreover, the system could be widely used in clinical diagnosis and photodynamic therapy for skin disease because even the irradiated time of fluorescence substance is short but it will provide accurately positioning of fluorescence object.

  14. Multiresolution 3-D reconstruction from side-scan sonar images.

    Science.gov (United States)

    Coiras, Enrique; Petillot, Yvan; Lane, David M

    2007-02-01

    In this paper, a new method for the estimation of seabed elevation maps from side-scan sonar images is presented. The side-scan image formation process is represented by a Lambertian diffuse model, which is then inverted by a multiresolution optimization procedure inspired by expectation-maximization to account for the characteristics of the imaged seafloor region. On convergence of the model, approximations for seabed reflectivity, side-scan beam pattern, and seabed altitude are obtained. The performance of the system is evaluated against a real structure of known dimensions. Reconstruction results for images acquired by different sonar sensors are presented. Applications to augmented reality for the simulation of targets in sonar imagery are also discussed.

  15. Fabrication of fine imaging devices using an external proton microbeam

    Energy Technology Data Exchange (ETDEWEB)

    Sakai, T., E-mail: sakai.takuro@jaea.go.jp [Quantum Beam Science Directorate, Japan Atomic Energy Agency (JAEA), Tokai, Ibaraki 319-1195 (Japan); Yasuda, R.; Iikura, H.; Nojima, T. [Quantum Beam Science Directorate, Japan Atomic Energy Agency (JAEA), Tokai, Ibaraki 319-1195 (Japan); Koka, M.; Satoh, T.; Ishii, Y. [Takasaki Advanced Radiation Research Institute, Japan Atomic Energy Agency (JAEA), Takasaki, Gunma 370-1292 (Japan); Oshima, A. [Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Osaka 567-0047 (Japan)

    2014-08-01

    We have successfully fabricated novel microscopic imaging devices made from UV/EB curable resin using an external scanning proton microbeam. The devices are micro-structured fluorescent plates that consist of an array of micro-pillars that align periodically. The base material used in the pillars is UV/EB curable resin and each pillar contains phosphor grains. The pattern exposures were performed using a proton beam writing technique. The height of the pillars depends on the range of the proton beam. Optical microscopy and scanning electron microscopy have been used to characterize the samples. The results show that the fabricated fluorescent plates are expected to be compatible with both spatial resolution and detection efficiency.

  16. A new clustering algorithm for scanning electron microscope images

    Science.gov (United States)

    Yousef, Amr; Duraisamy, Prakash; Karim, Mohammad

    2016-04-01

    A scanning electron microscope (SEM) is a type of electron microscope that produces images of a sample by scanning it with a focused beam of electrons. The electrons interact with the sample atoms, producing various signals that are collected by detectors. The gathered signals contain information about the sample's surface topography and composition. The electron beam is generally scanned in a raster scan pattern, and the beam's position is combined with the detected signal to produce an image. The most common configuration for an SEM produces a single value per pixel, with the results usually rendered as grayscale images. The captured images may be produced with insufficient brightness, anomalous contrast, jagged edges, and poor quality due to low signal-to-noise ratio, grained topography and poor surface details. The segmentation of the SEM images is a tackling problems in the presence of the previously mentioned distortions. In this paper, we are stressing on the clustering of these type of images. In that sense, we evaluate the performance of the well-known unsupervised clustering and classification techniques such as connectivity based clustering (hierarchical clustering), centroid-based clustering, distribution-based clustering and density-based clustering. Furthermore, we propose a new spatial fuzzy clustering technique that works efficiently on this type of images and compare its results against these regular techniques in terms of clustering validation metrics.

  17. Angularly-selective transmission imaging in a scanning electron microscope.

    Science.gov (United States)

    Holm, Jason; Keller, Robert R

    2016-08-01

    This work presents recent advances in transmission scanning electron microscopy (t-SEM) imaging control capabilities. A modular aperture system and a cantilever-style sample holder that enable comprehensive angular selectivity of forward-scattered electrons are described. When combined with a commercially available solid-state transmission detector having only basic bright-field and dark-field imaging capabilities, the advances described here enable numerous transmission imaging modes. Several examples are provided that demonstrate how contrast arising from diffraction to mass-thickness can be obtained. Unanticipated image contrast at some imaging conditions is also observed and addressed. Published by Elsevier B.V.

  18. Imaging Anyons with Scanning Tunneling Microscopy

    Science.gov (United States)

    Papić, Zlatko; Mong, Roger S. K.; Yazdani, Ali; Zaletel, Michael P.

    2018-01-01

    Anyons are exotic quasiparticles with fractional charge that can emerge as fundamental excitations of strongly interacting topological quantum phases of matter. Unlike ordinary fermions and bosons, they may obey non-Abelian statistics—a property that would help realize fault-tolerant quantum computation. Non-Abelian anyons have long been predicted to occur in the fractional quantum Hall (FQH) phases that form in two-dimensional electron gases in the presence of a large magnetic field, such as the ν =5 /2 FQH state. However, direct experimental evidence of anyons and tests that can distinguish between Abelian and non-Abelian quantum ground states with such excitations have remained elusive. Here, we propose a new experimental approach to directly visualize the structure of interacting electronic states of FQH states with the STM. Our theoretical calculations show how spectroscopy mapping with the STM near individual impurity defects can be used to image fractional statistics in FQH states, identifying unique signatures in such measurements that can distinguish different proposed ground states. The presence of locally trapped anyons should leave distinct signatures in STM spectroscopic maps, and enables a new approach to directly detect—and perhaps ultimately manipulate—these exotic quasiparticles.

  19. Device intended for measurement of induced trapped charge in insulating materials under electron irradiation in a scanning electron microscope

    International Nuclear Information System (INIS)

    Belkorissat, R; Benramdane, N; Jbara, O; Rondot, S; Hadjadj, A; Belhaj, M

    2013-01-01

    A device for simultaneously measuring two currents (i.e. leakage and displacement currents) induced in insulating materials under electron irradiation has been built. The device, suitably mounted on the sample holder of a scanning electron microscope (SEM), allows a wider investigation of charging and discharging phenomena that take place in any type of insulator during its electron irradiation and to determine accurately the corresponding time constants. The measurement of displacement current is based on the principle of the image charge due to the electrostatic influence phenomena. We are reporting the basic concept and test results of the device that we have built using, among others, the finite element method for its calibration. This last method takes into account the specimen chamber geometry, the geometry of the device and the physical properties of the sample. In order to show the possibilities of the designed device, various applications under different experimental conditions are explored. (paper)

  20. Scanning laser topography and scanning laser polarimetry: comparing both imaging methods at same distances from the optic nerve head.

    Science.gov (United States)

    Kremmer, Stephan; Keienburg, Marcus; Anastassiou, Gerasimos; Schallenberg, Maurice; Steuhl, Klaus-Peter; Selbach, J Michael

    2012-01-01

    To compare the performance of scanning laser topography (SLT) and scanning laser polarimetry (SLP) on the rim of the optic nerve head and its surrounding area and thereby to evaluate whether these imaging technologies are influenced by other factors beyond the thickness of the retinal nerve fiber layer (RNFL). A total of 154 eyes from 5 different groups were examined: young healthy subjects (YNorm), old healthy subjects (ONorm), patients with normal tension glaucoma (NTG), patients with open-angle glaucoma and early glaucomatous damage (OAGE) and patients with open-angle glaucoma and advanced glaucomatous damage (OAGA). SLT and SLP measurements were taken. Four concentric circles were superimposed on each of the images: the first one measuring at the rim of the optic nerve head (1.0 ONHD), the next measuring at 1.25 optic nerve head diameters (ONHD), at 1.5 ONHD and at 1.75 ONHD. The aligned images were analyzed using GDx/NFA software. Both methods showed peaks of RNFL thickness in the superior and inferior segments of the ONH. The maximum thickness, registered by the SLT device was at the ONH rim where the SLP device tended to measure the lowest values. SLT measurements at the ONH were influenced by other tissues besides the RNFL like blood vessels and glial tissues. SLT and SLP were most strongly correlated at distances of 1.25 and 1.5 ONHD. While both imaging technologies are valuable tools in detecting glaucoma, measurements at the ONH rim should be interpreted critically since both methods might provide misleading results. For the assessment of the retinal nerve fiber layer we would like to recommend for both imaging technologies, SLT and SLP, measurements in 1.25 and 1.5 ONHD distance of the rim of the optic nerve head.

  1. A study on Computer-controlled Ultrasonic Scanning Device

    International Nuclear Information System (INIS)

    Huh, H.; Park, C. S.; Hong, S. S.; Park, J. H.

    1989-01-01

    Since the nuclear power plants in Korea have been operated in 1979, the nondestructive testing (NDT) of pressure vessels and/or piping welds plays an important role for maintaining the safety and integrity of the plants. Ultrasonic method is superior to the other NDT method in the viewpoint of the detectability of small flaw and accuracy to determine the locations, sizes, orientations, and shapes. As the service time of the nuclear power plants is increased, the radiation level from the components is getting higher. In order to get more quantitative and reliable results and secure the inspector from the exposure to high radiation level, automation of the ultrasonic equipment has been one of the important research and development(R and D) subject. In this research, it was attempted to visualize the shape of flaws presented inside the specimen using a Modified C-Scan technique. In order to develop Modified C-Scan technique, an automatic ultrasonic scanner and a module to control the scanner were designed and fabricated. IBM-PC/XT was interfaced to the module to control the scanner. Analog signals from the SONIC MARK II were digitized by Analog-Digital Converter(ADC 0800) for Modified C-Scan display. A computer program has been developed and has capability of automatic data acquisition and processing from the digital data, which consist of maximum amplitudes in each gate range and locations. The data from Modified C-Scan results was compared with shape from artificial defects using the developed system. Focal length of focused transducer was measured. The automatic ultrasonic equipment developed through this study is essential for more accurate, reliable, and repeatable ultrasonic experiments. If the scanner are modified to meet to appropriate purposes, it can be applied to automation of ultrasonic examination of nuclear power plants and helpful to the research on ultrasonic characterization of the materials

  2. MR imaging of brain surface structures: Surface anatomy scanning

    International Nuclear Information System (INIS)

    Katada, K.; Koga, S.; Asahina, M.; Kanno, T.; Asahina, K.

    1987-01-01

    Preoperative evaluation of brain surface anatomy, including cortical sulci and veins, relative to cerebral and cerebellar lesions is an important subject for surgeons. Until now, no imaging modality existed that allowed direct visualization of brain surface anatomy. A new MR imaging technique (surface anatomy scanning) was developed to visualize brain surface structures. The technique uses a spin-echo pulse sequence with long repetition and echo times, thick sections and a surface coil. Cortical sulci, fissures, veins, and intracranial lesions were clearly identified with this technique. Initial clinical results indicate that surface anatomy scanning is useful for lesion localization and for detailed evaluation of cortical and subcortical lesions

  3. Imaging optical fields below metal films and metal-dielectric waveguides by a scanning microscope

    Science.gov (United States)

    Zhu, Liangfu; Wang, Yong; Zhang, Douguo; Wang, Ruxue; Qiu, Dong; Wang, Pei; Ming, Hai; Badugu, Ramachandram; Rosenfeld, Mary; Lakowicz, Joseph R.

    2017-09-01

    Laser scanning confocal fluorescence microscopy (LSCM) is now an important method for tissue and cell imaging when the samples are located on the surfaces of glass slides. In the past decade, there has been extensive development of nano-optical structures that display unique effects on incident and transmitted light, which will be used with novel configurations for medical and consumer products. For these applications, it is necessary to characterize the light distribution within short distances from the structures for efficient detection and elimination of bulky optical components. These devices will minimize or possibly eliminate the need for free-space light propagation outside of the device itself. We describe the use of the scanning function of a LSCM to obtain 3D images of the light intensities below the surface of nano-optical structures. More specifically, we image the spatial distributions inside the substrate of fluorescence emission coupled to waveguide modes after it leaks through thin metal films or dielectric-coated metal films. The observed spatial distribution were in general agreement with far-field calculations, but the scanning images also revealed light intensities at angles not observed with classical back focal plane imaging. Knowledge of the subsurface optical intensities will be crucial in the combination of nano-optical structures with rapidly evolving imaging detectors.

  4. Image scanning microscopy using a SPAD detector array (Conference Presentation)

    Science.gov (United States)

    Castello, Marco; Tortarolo, Giorgio; Buttafava, Mauro; Tosi, Alberto; Sheppard, Colin J. R.; Diaspro, Alberto; Vicidomini, Giuseppe

    2017-02-01

    The use of an array of detectors can help overcoming the traditional limitation of confocal microscopy: the compromise between signal and theoretical resolution. Each element independently records a view of the sample and the final image can be reconstructed by pixel reassignment or by inverse filtering (e.g. deconvolution). In this work, we used a SPAD array of 25 detectors specifically designed for this goal and our scanning microscopy control system (Carma) to acquire the partial images and to perform online image processing. Further work will be devoted to optimize the image reconstruction step and to improve the fill-factor of the detector.

  5. Analytical procedure for experimental quantification of carrier concentration in semiconductor devices by using electric scanning probe microscopy

    International Nuclear Information System (INIS)

    Fujita, Takaya; Matsumura, Koji; Itoh, Hiroshi; Fujita, Daisuke

    2014-01-01

    Scanning capacitance microscopy (SCM) is based on a contact-mode variant of atomic force microscopy, which is used for imaging two-dimensional carrier (electrons and holes) distributions in semiconductor devices. We introduced a method of quantification of the carrier concentration by experimentally deduced calibration curves, which were prepared for semiconductor materials such as silicon and silicon carbide. The analytical procedure was circulated to research organizations in a round-robin test. The effectiveness of the method was confirmed for practical analysis and for what is expected for industrial pre-standardization from the viewpoint of comparability among users. It was also applied to other electric scanning probe microscopy techniques such as scanning spreading resistance microscopy and scanning nonlinear dielectric microscopy. Their depth profiles of carrier concentration were found to be in good agreement with those characterized by SCM. These results suggest that our proposed method will be compatible with future next-generation microscopy. (paper)

  6. Multimodal backside imaging of a microcontroller using confocal laser scanning and optical-beam-induced current imaging

    Science.gov (United States)

    Finkeldey, Markus; Göring, Lena; Schellenberg, Falk; Brenner, Carsten; Gerhardt, Nils C.; Hofmann, Martin

    2017-02-01

    Microscopy imaging with a single technology is usually restricted to a single contrast mechanism. Multimodal imaging is a promising technique to improve the structural information that could be obtained about a device under test (DUT). Due to the different contrast mechanisms of laser scanning microscopy (LSM), confocal laser scanning microscopy (CLSM) and optical beam induced current microscopy (OBICM), a combination could improve the detection of structures in integrated circuits (ICs) and helps to reveal their layout. While OBIC imaging is sensitive to the changes between differently doped areas and to semiconductor-metal transitions, CLSM imaging is mostly sensitive to changes in absorption and reflection. In this work we present the implementation of OBIC imaging into a CLSM. We show first results using industry standard Atmel microcontrollers (MCUs) with a feature size of about 250nm as DUTs. Analyzing these types of microcontrollers helps to improve in the field of side-channel attacks to find hardware Trojans, possible spots for laser fault attacks and for reverse engineering. For the experimental results the DUT is placed on a custom circuit board that allows us to measure the current while imaging it in our in-house built stage scanning microscope using a near infrared (NIR) laser diode as light source. The DUT is thinned and polished, allowing backside imaging through the Si-substrate. We demonstrate the possibilities using this optical setup by evaluating OBIC, LSM and CLSM images above and below the threshold of the laser source.

  7. Imaging ballistic carrier trajectories in graphene using scanning gate microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Morikawa, Sei; Masubuchi, Satoru [Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro, Tokyo 153-8505 (Japan); Dou, Ziwei; Wang, Shu-Wei; Smith, Charles G.; Connolly, Malcolm R., E-mail: mrc61@cam.ac.uk [Cavendish Laboratory, Department of Physics, University of Cambridge, Cambridge CB3 0HE (United Kingdom); Watanabe, Kenji; Taniguchi, Takashi [National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044 (Japan); Machida, Tomoki, E-mail: tmachida@iis.u-tokyo.ac.jp [Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro, Tokyo 153-8505 (Japan); Institute for Nano Quantum Information Electronics, University of Tokyo, 4-6-1 Komaba, Meguro, Tokyo 153-8505 (Japan)

    2015-12-14

    We use scanning gate microscopy to map out the trajectories of ballistic carriers in high-mobility graphene encapsulated by hexagonal boron nitride and subject to a weak magnetic field. We employ a magnetic focusing geometry to image carriers that emerge ballistically from an injector, follow a cyclotron path due to the Lorentz force from an applied magnetic field, and land on an adjacent collector probe. The local electric field generated by the scanning tip in the vicinity of the carriers deflects their trajectories, modifying the proportion of carriers focused into the collector. By measuring the voltage at the collector while scanning the tip, we are able to obtain images with arcs that are consistent with the expected cyclotron motion. We also demonstrate that the tip can be used to redirect misaligned carriers back to the collector.

  8. Metrological characterization of 3D imaging devices

    Science.gov (United States)

    Guidi, G.

    2013-04-01

    Manufacturers often express the performance of a 3D imaging device in various non-uniform ways for the lack of internationally recognized standard requirements for metrological parameters able to identify the capability of capturing a real scene. For this reason several national and international organizations in the last ten years have been developing protocols for verifying such performance. Ranging from VDI/VDE 2634, published by the Association of German Engineers and oriented to the world of mechanical 3D measurements (triangulation-based devices), to the ASTM technical committee E57, working also on laser systems based on direct range detection (TOF, Phase Shift, FM-CW, flash LADAR), this paper shows the state of the art about the characterization of active range devices, with special emphasis on measurement uncertainty, accuracy and resolution. Most of these protocols are based on special objects whose shape and size are certified with a known level of accuracy. By capturing the 3D shape of such objects with a range device, a comparison between the measured points and the theoretical shape they should represent is possible. The actual deviations can be directly analyzed or some derived parameters can be obtained (e.g. angles between planes, distances between barycenters of spheres rigidly connected, frequency domain parameters, etc.). This paper shows theoretical aspects and experimental results of some novel characterization methods applied to different categories of active 3D imaging devices based on both principles of triangulation and direct range detection.

  9. Scanning tunneling microscope for magneto-optical imaging

    NARCIS (Netherlands)

    Prins, M.W.J.; Groeneveld, R.H.M.; Abraham, D.L.; Schad, R.; Kempen, van H.; Kesteren, van H.W.

    1996-01-01

    Images of magnetic bits written in a Pt/Co multilayer are presented. Using photosensitive semiconducting tips in a scanning tunneling microscope the surface topography as well as the polarization-dependent optical transmission are measured. Magnetic contrast is achieved by detection of the Faraday

  10. Hyperspectral imaging system for disease scanning on banana plants

    Science.gov (United States)

    Ochoa, Daniel; Cevallos, Juan; Vargas, German; Criollo, Ronald; Romero, Dennis; Castro, Rodrigo; Bayona, Oswaldo

    2016-05-01

    Black Sigatoka (BS) is a banana plant disease caused by the fungus Mycosphaerella fijiensis. BS symptoms can be observed at late infection stages. By that time, BS has probably spread to other plants. In this paper, we present our current work on building an hyper-spectral (HS) imaging system aimed at in-vivo detection of BS pre-symptomatic responses in banana leaves. The proposed imaging system comprises a motorized stage, a high-sensitivity VIS-NIR camera and an optical spectrograph. To capture images of the banana leaf, the stage's speed and camera's frame rate must be computed to reduce motion blur and to obtain the same resolution along both spatial dimensions of the resulting HS cube. Our continuous leaf scanning approach allows imaging leaves of arbitrary length with minimum frame loss. Once the images are captured, a denoising step is performed to improve HS image quality and spectral profile extraction.

  11. Fast, cheap and in control: spectral imaging with handheld devices

    Science.gov (United States)

    Gooding, Edward A.; Deutsch, Erik R.; Huehnerhoff, Joseph; Hajian, Arsen R.

    2017-05-01

    Remote sensing has moved out of the laboratory and into the real world. Instruments using reflection or Raman imaging modalities become faster, cheaper and more powerful annually. Enabling technologies include virtual slit spectrometer design, high power multimode diode lasers, fast open-loop scanning systems, low-noise IR-sensitive array detectors and low-cost computers with touchscreen interfaces. High-volume manufacturing assembles these components into inexpensive portable or handheld devices that make possible sophisticated decision-making based on robust data analytics. Examples include threat, hazmat and narcotics detection; remote gas sensing; biophotonic screening; environmental remediation and a host of other applications.

  12. Electric field effects in scanning tunneling microscope imaging

    DEFF Research Database (Denmark)

    Stokbro, Kurt; Quaade, Ulrich; Grey, Francois

    1998-01-01

    We present a high-voltage extension of the Tersoff-Hamann theory of scanning tunneling microscope (STM) images, which includes the effect of the electric field between the tip and the sample. The theoretical model is based on first-principles electronic structure calculations and has no adjustable...... parameters. We use the method to calculate theoretical STM images of the monohydrate Si(100)-H(2x1) surface with missing hydrogen defects at -2V and find an enhanced corrugation due to the electric field, in good agreement with experimental images....

  13. Magnetic resonance imaging of implantable cardiac rhythm devices at 3.0 tesla.

    Science.gov (United States)

    Gimbel, J Rod

    2008-07-01

    A relaxation of the prohibition of scanning cardiac rhythm device patients is underway, largely because of the growing experience of safe scanning events at 1.5T. Magnetic resonance imaging (MRI) at 3T is becoming more common and may pose a different risk profile and outcome of MRI of cardiac device patients. No restrictions were placed on pacemaker dependency, region scanned, device type, or manufacturer. Sixteen scans at 3T were performed with an electrophysiologist present on 14 patients with a variety of devices from various manufacturers. An "MRI-S" strategy was used. Multimodal monitoring was required. Device interrogation was performed prior to, immediately after, and 1-3 months after the MRI. For nonpacemaker-dependent device patients, attempts were made to turn all device features off (with OOO programming the goal) conceptually rendering the device "invisible." In pacemaker-dependent patients, the device was programmed to asynchronous mode at highest output for the duration of the scan with the goal of rendering the device conceptually "invulnerable" to MRI effects. The specific absorption rate (SAR) was limited to 2W/kg. All patients were successfully scanned. No arrhythmias were noted. No significant change in the programmed parameters, pacing thresholds, sensing, impedance, or battery parameters was noted. The insertable loop recorder (ILR) recorded prolonged artifactual asystole during MRI. One patient noted chest burning during the scan. Device patients may undergo carefully tailored 3T MRI scans when pre-MRI reprogramming of the device occurs in conjunction with extensive monitoring, supervision, and follow-up.

  14. An ultrahigh vacuum fast-scanning and variable temperature scanning tunneling microscope for large scale imaging.

    Science.gov (United States)

    Diaconescu, Bogdan; Nenchev, Georgi; de la Figuera, Juan; Pohl, Karsten

    2007-10-01

    We describe the design and performance of a fast-scanning, variable temperature scanning tunneling microscope (STM) operating from 80 to 700 K in ultrahigh vacuum (UHV), which routinely achieves large scale atomically resolved imaging of compact metallic surfaces. An efficient in-vacuum vibration isolation and cryogenic system allows for no external vibration isolation of the UHV chamber. The design of the sample holder and STM head permits imaging of the same nanometer-size area of the sample before and after sample preparation outside the STM base. Refractory metal samples are frequently annealed up to 2000 K and their cooldown time from room temperature to 80 K is 15 min. The vertical resolution of the instrument was found to be about 2 pm at room temperature. The coarse motor design allows both translation and rotation of the scanner tube. The total scanning area is about 8 x 8 microm(2). The sample temperature can be adjusted by a few tens of degrees while scanning over the same sample area.

  15. Positron annihilation imaging device having movable collimator

    International Nuclear Information System (INIS)

    Thompson, C.J.

    1981-01-01

    This patent application relates to a positron annihilation imaging device comprising two circular arrays of detectors disposed in spaced apart parallel planes and circumferentially offset by half the detector spacing, axially movable annular outer collimator rings, generally disposed in a pair of opposite planes outside the associated planes of the detectors, each collimator being movable toward the opposite collimator. An inner collimator of annular configuration is disposed between the two rows of detectors and is formed in two rings which may be separated axially. The outer and inner collimators serve to enhance data readout and imaging. (author)

  16. Movable collimator for positron annihilation imaging device

    International Nuclear Information System (INIS)

    Thompson, C.J.

    1981-01-01

    A positron annihilation imaging device having two circular arrays of detectors disposed in spaced apart parallel planes wherein axially movable annular collimator rings are generally disposed in a pair of opposite planes outside the associated planes of the collimators to each collimator being movable toward the opposite collimator and a central collimator of annular configuration generally disposed between the two rows of detectors but being split into two rings which may be separated, the outer and inner collimators serving to enhance data readout and imaging

  17. Probing superconductors. Spectroscopic-imaging scanning tunneling microscopy

    International Nuclear Information System (INIS)

    Hanaguri, Tetsuo

    2011-01-01

    Discovery of high-temperature superconductivity in a cuprate triggered developments of various spectroscopic tools which have been utilized to elucidate electronic states of this mysterious compound. Particularly, angle-resolved photoemission spectroscopy and scanning-tunneling microscopy/spectroscopy are improved considerably. It is now possible to map the superconducting gap in both momentum and real spaces using these two techniques. Here we review spectroscopic-imaging scanning tunneling microscopy which is able to explore momentum-space phase structure of the superconducting gap, as well as real-space structure. Applications of this technique to a cuprate and an iron-based superconductor are discussed. (author)

  18. Developing optimized CT scan protocols: Phantom measurements of image quality

    International Nuclear Information System (INIS)

    Zarb, Francis; Rainford, Louise; McEntee, Mark F.

    2011-01-01

    Purpose: The increasing frequency of computerized tomography (CT) examinations is well documented, leading to concern about potential radiation risks for patients. However, the consequences of not performing the CT examination and missing injuries and disease are potentially serious, impacting upon correct patient management. The ALARA principle of dose optimization must be employed for all justified CT examinations. Dose indicators displayed on the CT console as either CT dose index (CTDI) and/or dose length product (DLP), are used to indicate dose and can quantify improvements achieved through optimization. Key scan parameters contributing to dose have been identified in previous literature and in previous work by our group. The aim of this study was to optimize the scan parameters of mA; kV and pitch, whilst maintaining image quality and reducing dose. This research was conducted using psychophysical image quality measurements on a CT quality assurance (QA) phantom establishing the impact of dose optimization on image quality parameters. Method: Current CT scan parameters for head (posterior fossa and cerebrum), abdomen and chest examinations were collected from 57% of CT suites available nationally in Malta (n = 4). Current scan protocols were used to image a Catphan 600 CT QA phantom whereby image quality was assessed. Each scan parameter: mA; kV and pitch were systematically reduced until the contrast resolution (CR), spatial resolution (SR) and noise were significantly lowered. The Catphan 600 images, produced by the range of protocols, were evaluated by 2 expert observers assessing CR, SR and noise. The protocol considered as the optimization threshold was just above the setting that resulted in a significant reduction in CR and noise but not affecting SR at the 95% confidence interval. Results: The limit of optimization threshold was determined for each CT suite. Employing optimized parameters, CTDI and DLP were both significantly reduced (p ≤ 0.001) by

  19. ConoSurf: Open-source 3D scanning system based on a conoscopic holography device for acquiring surgical surfaces.

    Science.gov (United States)

    Brudfors, Mikael; García-Vázquez, Verónica; Sesé-Lucio, Begoña; Marinetto, Eugenio; Desco, Manuel; Pascau, Javier

    2017-09-01

    A difficulty in computer-assisted interventions is acquiring the patient's anatomy intraoperatively. Standard modalities have several limitations: low image quality (ultrasound), radiation exposure (computed tomography) or high costs (magnetic resonance imaging). An alternative approach uses a tracked pointer; however, the pointer causes tissue deformation and requires sterilizing. Recent proposals, utilizing a tracked conoscopic holography device, have shown promising results without the previously mentioned drawbacks. We have developed an open-source software system that enables real-time surface scanning using a conoscopic holography device and a wide variety of tracking systems, integrated into pre-existing and well-supported software solutions. The mean target registration error of point measurements was 1.46 mm. For a quick guidance scan, surface reconstruction improved the surface registration error compared with point-set registration. We have presented a system enabling real-time surface scanning using a tracked conoscopic holography device. Results show that it can be useful for acquiring the patient's anatomy during surgery. © 2016 The Authors. The International Journal of Medical Robotics and Computer Assisted Surgery Published by John Wiley & Sons Ltd.

  20. Comparison of CT scanning and radionuclide imaging in liver disease

    International Nuclear Information System (INIS)

    Friedman, M.L.; Esposito, F.S.

    1980-01-01

    Early experience with body CT suggested its usefulness in many diagnostic problems; jaundice, renal and pancreatic masses, and in the evaluation of relatively inaccessible parts of the body, such as the retroperitineum, mediastinum, and pelvis. Investigation of hepatic disease by CT was not unexpectedly compared to radionuclide liver scanning, the major preexisting modality for imaging the liver. In the evaluation of the jaundiced patient, CT rapidly assumed a major role, providing more specific information about the liver than the RN liver scan, as well as demonstrating adjacent organs. CT differentiate obstructive from non-obstructive jaundice. With respect to mass lesions of the liver, the RN liver scan is more sensitive than CT but less specific. The abnormalities on an isotope image of the liver consist of normal variants in configuration, extrinsic compression by adjacent structures, cysts, hemangiomata, abscesses, and neoplasms. These suspected lesions may then be better delineated by the CT image, and a more precise diagnosis made. The physiologic information provided by the RN liver scan is an added facet which is helpful in the patient with diffuse hepatic disease. The CT image will be normal in many of these patients, however, hemochromatosis and fatty infiltration lend themselves especially to density evaluation by CT. The evaluation of lymphoma is more thorough with CT. Structures other than the liver, such as lymph nodes, are visualized. Gallium, however, provides additional isotopic information in patients with lymphoma, and in addition, is known to be useful in the investigation of a febrile patient with an abscess. Newer isotopic agents expand hepatic imaging in other directions, visualizing the biliary tree and evaluating the jaundiced patient

  1. Dynamic autofocus for continuous-scanning time-delay-and-integration image acquisition in automated microscopy.

    Science.gov (United States)

    Bravo-Zanoguera, Miguel E; Laris, Casey A; Nguyen, Lam K; Oliva, Mike; Price, Jeffrey H

    2007-01-01

    Efficient image cytometry of a conventional microscope slide means rapid acquisition and analysis of 20 gigapixels of image data (at 0.3-microm sampling). The voluminous data motivate increased acquisition speed to enable many biomedical applications. Continuous-motion time-delay-and-integrate (TDI) scanning has the potential to speed image acquisition while retaining sensitivity, but the challenge of implementing high-resolution autofocus operating simultaneously with acquisition has limited its adoption. We develop a dynamic autofocus system for this need using: 1. a "volume camera," consisting of nine fiber optic imaging conduits to charge-coupled device (CCD) sensors, that acquires images in parallel from different focal planes, 2. an array of mixed analog-digital processing circuits that measure the high spatial frequencies of the multiple image streams to create focus indices, and 3. a software system that reads and analyzes the focus data streams and calculates best focus for closed feedback loop control. Our system updates autofocus at 56 Hz (or once every 21 microm of stage travel) to collect sharply focused images sampled at 0.3x0.3 microm(2)/pixel at a stage speed of 2.3 mms. The system, tested by focusing in phase contrast and imaging long fluorescence strips, achieves high-performance closed-loop image-content-based autofocus in continuous scanning for the first time.

  2. Humidity effects on scanning polarization force microscopy imaging

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Yue, E-mail: shenyue@isl.ac.cn [Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources, Key Laboratory of Salt Lake Resources Chemistry of Qinghai Province, Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining, Qinghai 810008 (China); Key Laboratory of Interfacial Physics and Technology of Chinese Academy of Sciences, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Zhou, Yuan, E-mail: zhouy@isl.ac.cn [Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources, Key Laboratory of Salt Lake Resources Chemistry of Qinghai Province, Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining, Qinghai 810008 (China); Sun, Yanxia; Zhang, Lijuan [Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources, Key Laboratory of Salt Lake Resources Chemistry of Qinghai Province, Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining, Qinghai 810008 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Wang, Ying; Hu, Jun; Zhang, Yi [Key Laboratory of Interfacial Physics and Technology of Chinese Academy of Sciences, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China)

    2017-08-01

    Highlights: • The humidity dramatically affects the contrast of scanning polarization force microscopy (SPFM) imaging on mica surface. • This influence roots in the sensitive dielectric constant of mica surface to the humidity change. • A strategy of controllable and repeatable imaging the local dielectric properties of nanomaterials with SPFM is proposed. - Abstract: Scanning polarization force microscopy (SPFM) is a useful surface characterization technique to visually characterize and distinguish nanomaterial with different local dielectric properties at nanometer scale. In this paper, taking the individual one-atom-thick graphene oxide (GO) and reduced graphene oxide (rGO) sheets on mica as examples, we described the influences of environmental humidity on SPFM imaging. We found that the apparent heights (AHs) or contrast of SPFM imaging was influenced significantly by relative humidity (RH) at a response time of a few seconds. And this influence rooted in the sensitive dielectric constant of mica surface to the RH change. While dielectric properties of GO and rGO sheets were almost immune to the humidity change. In addition, we gave the method to determine the critical humidity at which the contrast conversion happened under different conditions. And this is important to the contrast control and repeatable imaging of SPFM through RH adjusting. These findings suggest a strategy of controllable and repeatable imaging the local dielectric properties of nanomaterials with SPFM, which is critically important for further distinguishment, manipulation, electronic applications, etc.

  3. Image Quality Characteristics of Handheld Display Devices for Medical Imaging

    Science.gov (United States)

    Yamazaki, Asumi; Liu, Peter; Cheng, Wei-Chung; Badano, Aldo

    2013-01-01

    Handheld devices such as mobile phones and tablet computers have become widespread with thousands of available software applications. Recently, handhelds are being proposed as part of medical imaging solutions, especially in emergency medicine, where immediate consultation is required. However, handheld devices differ significantly from medical workstation displays in terms of display characteristics. Moreover, the characteristics vary significantly among device types. We investigate the image quality characteristics of various handheld devices with respect to luminance response, spatial resolution, spatial noise, and reflectance. We show that the luminance characteristics of the handheld displays are different from those of workstation displays complying with grayscale standard target response suggesting that luminance calibration might be needed. Our results also demonstrate that the spatial characteristics of handhelds can surpass those of medical workstation displays particularly for recent generation devices. While a 5 mega-pixel monochrome workstation display has horizontal and vertical modulation transfer factors of 0.52 and 0.47 at the Nyquist frequency, the handheld displays released after 2011 can have values higher than 0.63 at the respective Nyquist frequencies. The noise power spectra for workstation displays are higher than 1.2×10−5 mm2 at 1 mm−1, while handheld displays have values lower than 3.7×10−6 mm2. Reflectance measurements on some of the handheld displays are consistent with measurements for workstation displays with, in some cases, low specular and diffuse reflectance coefficients. The variability of the characterization results among devices due to the different technological features indicates that image quality varies greatly among handheld display devices. PMID:24236113

  4. Space Radar Image of West Texas - SAR scan

    Science.gov (United States)

    1999-01-01

    This radar image of the Midland/Odessa region of West Texas, demonstrates an experimental technique, called ScanSAR, that allows scientists to rapidly image large areas of the Earth's surface. The large image covers an area 245 kilometers by 225 kilometers (152 miles by 139 miles). It was obtained by the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) flying aboard the space shuttle Endeavour on October 5, 1994. The smaller inset image is a standard SIR-C image showing a portion of the same area, 100 kilometers by 57 kilometers (62 miles by 35 miles) and was taken during the first flight of SIR-C on April 14, 1994. The bright spots on the right side of the image are the cities of Odessa (left) and Midland (right), Texas. The Pecos River runs from the top center to the bottom center of the image. Along the left side of the image are, from top to bottom, parts of the Guadalupe, Davis and Santiago Mountains. North is toward the upper right. Unlike conventional radar imaging, in which a radar continuously illuminates a single ground swath as the space shuttle passes over the terrain, a Scansar radar illuminates several adjacent ground swaths almost simultaneously, by 'scanning' the radar beam across a large area in a rapid sequence. The adjacent swaths, typically about 50 km (31 miles) wide, are then merged during ground processing to produce a single large scene. Illumination for this L-band scene is from the top of the image. The beams were scanned from the top of the scene to the bottom, as the shuttle flew from left to right. This scene was acquired in about 30 seconds. A normal SIR-C image is acquired in about 13 seconds. The ScanSAR mode will likely be used on future radar sensors to construct regional and possibly global radar images and topographic maps. The ScanSAR processor is being designed for 1996 implementation at NASA's Alaska SAR Facility, located at the University of Alaska Fairbanks, and will produce digital images from the

  5. Optimal scanning and image processing with the STEM

    International Nuclear Information System (INIS)

    Crewe, A.V.; Ohtsuki, M.

    1981-01-01

    We have recently published a theory of an optimal scanning system which is particularly suited for the STEM. One concludes from the theory that the diffraction limit of the electron probe should be a fixed fraction of the full-scale deflection in order to avoid scanning artifacts. More recently, we have confirmed the value of this technique by direct experiments. Our program now is to combine the use of optimal scanning with the use of a programmable digital refresh memory for image analysis. Limited experience to date indicates that false color conversion is probably more useful than histogram equalization in black and white and that this system is particularly valuable for rotational averaging and selected area Fourier transforms. (orig.)

  6. Advances in imaging and electron physics the scanning transmission electron microscope

    CERN Document Server

    Hawkes, Peter W

    2009-01-01

    Advances in Imaging and Electron Physics merges two long-running serials--Advances in Electronics and Electron Physics and Advances in Optical and Electron Microscopy. This series features extended articles on the physics of electron devices (especially semiconductor devices), particle optics at high and low energies, microlithography, image science and digital image processing, electromagnetic wave propagation, electron microscopy, and the computing methods used in all these domains.  This particular volume presents several timely articles on the scanning transmission electron microscope. Updated with contributions from leading international scholars and industry experts Discusses hot topic areas and presents current and future research trends Provides an invaluable reference and guide for physicists, engineers and mathematicians.

  7. High-speed adaptive optics line scan confocal retinal imaging for human eye.

    Science.gov (United States)

    Lu, Jing; Gu, Boyu; Wang, Xiaolin; Zhang, Yuhua

    2017-01-01

    Continuous and rapid eye movement causes significant intraframe distortion in adaptive optics high resolution retinal imaging. To minimize this artifact, we developed a high speed adaptive optics line scan confocal retinal imaging system. A high speed line camera was employed to acquire retinal image and custom adaptive optics was developed to compensate the wave aberration of the human eye's optics. The spatial resolution and signal to noise ratio were assessed in model eye and in living human eye. The improvement of imaging fidelity was estimated by reduction of intra-frame distortion of retinal images acquired in the living human eyes with frame rates at 30 frames/second (FPS), 100 FPS, and 200 FPS. The device produced retinal image with cellular level resolution at 200 FPS with a digitization of 512×512 pixels/frame in the living human eye. Cone photoreceptors in the central fovea and rod photoreceptors near the fovea were resolved in three human subjects in normal chorioretinal health. Compared with retinal images acquired at 30 FPS, the intra-frame distortion in images taken at 200 FPS was reduced by 50.9% to 79.7%. We demonstrated the feasibility of acquiring high resolution retinal images in the living human eye at a speed that minimizes retinal motion artifact. This device may facilitate research involving subjects with nystagmus or unsteady fixation due to central vision loss.

  8. Simulation study of secondary electron images in scanning ion microscopy

    CERN Document Server

    Ohya, K

    2003-01-01

    The target atomic number, Z sub 2 , dependence of secondary electron yield is simulated by applying a Monte Carlo code for 17 species of metals bombarded by Ga ions and electrons in order to study the contrast difference between scanning ion microscopes (SIM) and scanning electron microscopes (SEM). In addition to the remarkable reversal of the Z sub 2 dependence between the Ga ion and electron bombardment, a fine structure, which is correlated to the density of the conduction band electrons in the metal, is calculated for both. The brightness changes of the secondary electron images in SIM and SEM are simulated using Au and Al surfaces adjacent to each other. The results indicate that the image contrast in SIM is much more sensitive to the material species and is clearer than that for SEM. The origin of the difference between SIM and SEM comes from the difference in the lateral distribution of secondary electrons excited within the escape depth.

  9. Local crystallography analysis for atomically resolved scanning tunneling microscopy images

    International Nuclear Information System (INIS)

    Lin, Wenzhi; Li, Qing; Belianinov, Alexei; Gai, Zheng; Baddorf, Arthur P; Pan, Minghu; Jesse, Stephen; Kalinin, Sergei V; Sales, Brian C; Sefat, Athena

    2013-01-01

    Scanning probe microscopy has emerged as a powerful and flexible tool for atomically resolved imaging of surface structures. However, due to the amount of information extracted, in many cases the interpretation of such data is limited to being qualitative and semi-quantitative in nature. At the same time, much can be learned from local atom parameters, such as distances and angles, that can be analyzed and interpreted as variations of local chemical bonding, or order parameter fields. Here, we demonstrate an iterative algorithm for indexing and determining atomic positions that allows the analysis of inhomogeneous surfaces. This approach is further illustrated by local crystallographic analysis of several real surfaces, including highly ordered pyrolytic graphite and an Fe-based superconductor FeTe 0.55 Se 0.45 . This study provides a new pathway to extract and quantify local properties for scanning probe microscopy images. (paper)

  10. Modifying a Rodenstock scanning laser ophthalmoscope for imaging densitometry.

    Science.gov (United States)

    Tornow, R P; Beuel, S; Zrenner, E

    1997-08-01

    The necessary modifications and technical requirements are described for using a commercially available scanning laser ophthalmoscope (Rodenstock Model 101 SLO) as an imaging densitometer to assess human photopigment distribution. The main requirements are a linear detector amplifier, fast shutters for the laser beams, and a trigger unit. Images must be compensated for varying laser intensity. Both rod and cone photopigments are measured with the 514-nm argon laser of the SLO. Discrimination is possible owing to the different spatial distribution. The cone pigment density peaks in the foveal center (D = 0.40) with a steep decrease with increasing eccentricity E (full width at half-maximum, 2.5 degrees ). Rod photopigment increases with increasing eccentricity (D = 0.23 for E = 11 degrees ). These values are in agreement with previous reported results obtained with scanning laser ophthalmoscopes specially designed for retinal densitometry and high stability.

  11. Images of a poe(rotic body scanned

    Directory of Open Access Journals (Sweden)

    Adriana Carolina Hipólito de Assis

    2014-04-01

    This study aims to determine how the poetic eroticized body is evident in the visual images of some works of the poet, translator and literary critic Brazilian Décio Pignatari, as well as put on the reintegration of this debate in the media desiring body from the critical explained by the Mexican poet and essayist Octávio Paz is work Conjunções e Disjunções (1979. To address this body lov(erotic as cut corpus study of the work: Poesia Pois é Poesia, of Décio Pignatari (2004. Poetry expressing the brand and put in concrete dialogue resulting images of translating a digital body that extends (McLuhan while communication apparatus, media convergence in the conception of art as scanned image, such as sensory, tactile, eroticized body. Attendance plastic, tangible reflecting a face that survives own image: a concrete icon.

  12. Adaptive optics scanning laser ophthalmoscope imaging: technology update

    Directory of Open Access Journals (Sweden)

    Merino D

    2016-04-01

    Full Text Available David Merino, Pablo Loza-Alvarez The Institute of Photonic Sciences (ICFO, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona, Spain Abstract: Adaptive optics (AO retinal imaging has become very popular in the past few years, especially within the ophthalmic research community. Several different retinal techniques, such as fundus imaging cameras or optical coherence tomography systems, have been coupled with AO in order to produce impressive images showing individual cell mosaics over different layers of the in vivo human retina. The combination of AO with scanning laser ophthalmoscopy has been extensively used to generate impressive images of the human retina with unprecedented resolution, showing individual photoreceptor cells, retinal pigment epithelium cells, as well as microscopic capillary vessels, or the nerve fiber layer. Over the past few years, the technique has evolved to develop several different applications not only in the clinic but also in different animal models, thanks to technological developments in the field. These developments have specific applications to different fields of investigation, which are not limited to the study of retinal diseases but also to the understanding of the retinal function and vision science. This review is an attempt to summarize these developments in an understandable and brief manner in order to guide the reader into the possibilities that AO scanning laser ophthalmoscopy offers, as well as its limitations, which should be taken into account when planning on using it. Keywords: high-resolution, in vivo retinal imaging, AOSLO

  13. Quality Assurance By Laser Scanning And Imaging Techniques

    Science.gov (United States)

    SchmalfuB, Harald J.; Schinner, Karl Ludwig

    1989-03-01

    Laser scanning systems are well established in the world of fast industrial in-process quality inspection systems. The materials inspected by laser scanning systems are e.g. "endless" sheets of steel, paper, textile, film or foils. The web width varies from 50 mm up to 5000 mm or more. The web speed depends strongly on the production process and can reach several hundred meters per minute. The continuous data flow in one of different channels of the optical receiving system exceeds ten Megapixels/sec. Therefore it is clear that the electronic evaluation system has to process these data streams in real time and no image storage is possible. But sometimes (e.g. first installation of the system, change of the defect classification) it would be very helpful to have the possibility for a visual look on the original, i.e. not processed sensor data. At first we show the principle set up of a standard laser scanning system. Then we will introduce a large image memory especially designed for the needs of high-speed inspection sensors. This image memory co-operates with the standard on-line evaluation electronics and provides therefore an easy comparison between processed and non-processed data. We will discuss the basic system structure and we will show the first industrial results.

  14. High-resolution imaging in the scanning transmission electron microscope

    International Nuclear Information System (INIS)

    Pennycook, S.J.; Jesson, D.E.

    1992-03-01

    The high-resolution imaging of crystalline materials in the scanning transmission electron microscopy (STEM) is reviewed with particular emphasis on the conditions under which an incoherent image can be obtained. It is shown that a high-angle annular detector can be used to break the coherence of the imaging process, in the transverse plane through the geometry of the detector, or in three dimensions if multiphonon diffuse scattering is detected. In the latter case, each atom can be treated as a highly independent source of high-angle scattering. The most effective fast electron states are therefore tightly bound s-type Bloch states. Furthermore, they add constructively for each incident angle in the coherent STEM probe, so that s states are responsible for practically the entire image contrast. Dynamical effects are largely removed, and almost perfect incoherent imaging is achieved. s states are relatively insensitive to neighboring strings, so that incoherent imaging is maintained for superlattice and interfaces, and supercell calculations are unnecessary. With an optimum probe profile, the incoherent image represents a direct image of the crystal projection, with compositional sensitivity built in through the strong dependence of the scattering cross sections on atomic number Z

  15. Development of Scanning-Imaging X-Ray Microscope for Quantitative Three-Dimensional Phase Contrast Microimaging

    International Nuclear Information System (INIS)

    Takeuchi, Akihisa; Suzuki, Yoshio; Uesugi, Kentaro

    2013-01-01

    A novel x-ray microscope system has been developed for the purpose of quantitative and sensitive three-dimensional (3D) phase-contrast x-ray microimaging. The optical system is a hybrid that consists of a scanning microscope optics with a one-dimensional (1D) focusing (line-focusing) device and an imaging microscope optics with a 1D objective. These two optics are orthogonally arranged regarding their common optical axis. Each is used for forming each dimension of two-dimensional (2D) image. The same data acquisition process as that of the scanning microscope system enables quantitative and sensitive x-ray imaging such as phase contrast and absorption contrast. Because a 2D image is measured with only 1D translation scan, much shorter measurement time than that of conventional scanning optics has been realized. By combining a computed tomography (CT) technique, some 3D CT application examples are demonstrated

  16. Effects of scanning resolution and digital image magnification on photostimulable phosphor imaging system

    International Nuclear Information System (INIS)

    Sakurai, Takashi; Inagaki, Masafumi; Asai, Hideomi; Koyama, Atsushi; Kashima, Isamu

    2000-01-01

    The purpose of this study is to examine the effects of changes in scanning resolution and digital magnification on the image quality and diagnostic ability of the photostimulable phosphor imaging system. Using a photostimulable phosphor imaging system, images of a human adult dried mandible phantom embedded in a 25 mm-thick epoxy resin block were made. The latent images on the photostimulable phosphor imaging plate were scanned using four different pixel sizes as follows: 25 μm x 25 μm, 50 μm x 50 μm, 100 μm x 100 μm and 200 μm x 200 μm. A primary image was produced for each pixel size. These images were also digitally magnified at powers of 2, 4 and 8 times. The gradient range, brightness and contrast of each image were adjusted to optimum levels on a cathode ray tube display, and hard copies were produced with a writing pixel size of 60 μm x 60 μm. The granularity, sharpness and anatomical diagnostic ability of the images were assessed subjectively by eight dentists. Increasing the scanning resolution tended to generally improve image quality and diagnostic ability. Visual image quality was maintained up to a pixel size of 50 μm, and diagnostic ability was maintained up to a pixel size of 100 μm. Digital image magnification degraded image quality, and more than 2-times magnification degraded diagnostic ability. Under the present experimental conditions, increasing the scanning resolution did not always lead to an improvement in image quality or diagnostic ability, and digital image magnification degraded image quality and diagnostic ability. (author)

  17. Cardiac imaging systems and methods employing computerized tomographic scanning

    International Nuclear Information System (INIS)

    Richey, J.B.; Wake, R.H.; Walters, R.G.; Hunt, W.F.; Cool, S.L.

    1980-01-01

    The invention relates to cardiac imaging systems and methods employing computerised tomographic scanning. Apparatus is described which allows an image of the radiation attenuation of the heart at a desired phase of the cardiac cycle. The patients ECG signal can be used in a transverse-and-rotate type CT scanner as a time base, so that the beam reaches the heart at a desired phase of the cardiac cycle, or, in a purely rotational-type CT scanner continuously generated scan data is only stored for corresponding phases of successive cardiac cycles. Alternatively, gating of the beams themselves by shuttering or switching the power supply can be controlled by the ECG signal. A pacemaker is used to stabilize the cardiac period. Also used is a system for recognising unacceptable variations in the cardiac period and discarding corresponding scan data. In a transverse-and-rotate type fan-beam CT scanner, the effective beam width is narrowed to reduce the duration of the traverse of the heart. (U.K.)

  18. Quality assurance for electronic portal imaging devices

    International Nuclear Information System (INIS)

    Shalev, S.; Rajapakshe, R.; Gluhchev, G.; Luchka, K.

    1997-01-01

    Electronic portal imaging devices (EPIDS) are assuming an ever-increasing role in the verification of radiation treatment accuracy. They are used both in a passive capacity, for the determination of field displacement distributions (''setup errors''), and also in an active role whereby the patient setup is corrected on the basis of electronic portal images. In spite of their potential impact on the precision of patient treatment, there are few quality assurance procedures available, and most of the EPIDS in clinical use are subject, at best, to only perfunctory quality assurance. The goals of this work are (a) to develop an objective and reproducible test for EPID image quality on the factory floor and during installation of the EPID on site; (b) to provide the user with a simple and accurate tool for acceptance, commissioning, and routine quality control; and (c) to initiate regional, national and international collaboration in the implementation of standardized, objective, and automated quality assurance procedures. To this end we have developed an automated test in which a simple test object is imaged daily, and the spatial and contrast resolution of the EPID are automatically evaluated in terms of ''acceptable'', ''warning'' and ''stop'' criteria. Our experience over two years shows the test to be highly sensitive, reproducible, and inexpensive in time and effort. Inter-institutional trials are under way in Canada, US and Europe which indicate large variations in EPID image quality from one EPID to another, and from one center to another. We expect the new standardized quality assurance procedure to lead to improved, and consistent image quality, increased operator acceptance of the technology, and agreement on uniform standards by equipment suppliers and health care agencies. (author)

  19. Quantitative phase imaging with scanning holographic microscopy: an experimental assesment

    Directory of Open Access Journals (Sweden)

    Tada Yoshitaka

    2006-11-01

    Full Text Available Abstract This paper demonstrates experimentally how quantitative phase information can be obtained in scanning holographic microscopy. Scanning holography can operate in both coherent and incoherent modes, simultaneously if desired, with different detector geometries. A spatially integrating detector provides an incoherent hologram of the object's intensity distribution (absorption and/or fluorescence, for example, while a point detector in a conjugate plane of the pupil provides a coherent hologram of the object's complex amplitude, from which a quantitative measure of its phase distribution can be extracted. The possibility of capturing simultaneously holograms of three-dimensional specimens, leading to three-dimensional reconstructions with absorption contrast, reflectance contrast, fluorescence contrast, as was previously demonstrated, and quantitative phase contrast, as shown here for the first time, opens up new avenues for multimodal imaging in biological studies.

  20. SUPPORTING UAVS IN LOW VISIBILITY CONDITIONS BY MULTIPLE-PULSE LASER SCANNING DEVICES

    Directory of Open Access Journals (Sweden)

    A. Djuricic

    2013-04-01

    Full Text Available Unmanned Aerial Vehicles (UAVs are nowadays promising platforms for capturing spatial information, because they are low cost solutions, which are easy to bring to the surveying field and can operate automatically. Usually these devices are equipped with visual sensors to support the navigation of the platform or to transmit observations of the environment to the operator. By collecting the data and processing the captured images even an estimation of the observed environment in form of 3D information is available. Therefore Simultaneous Localization and Mapping (SLAM algorithms are well known for processing data which is captured in the visible domain. However, situations can occur where gathering visual information is difficult due to given limitations in form of low visibility. For example if soft obstacles in form of translucent materials are given in disaster scenarios with smoke and operating has still to be ensured, active optical sensors (e.g. laser scanners are gaining interest because they can penetrate the soft obstacle and allow to acquire information behind it. A new lightweight (210 g, simplified and minimized scanning unit is now available which allows to capture multiple reflections for each transmitted laser pulse, namely the Hokuyo UTM-30LX-EW. With such a device, it is possible to overcome the above mentioned restrictions or limitations of low visibility by soft obstacles and even measure under critical circumstances. A multi-pulse system can provide accurate measurements on, within, and behind the soft obstacle. This research focuses on investigating the ability and performance of a laser scanner to penetrate the soft obstacle. Thus, investigations on a system that overcomes these limitations and provides a solution will be given. First promising experimental results considering soft obstacle are described.

  1. Neural Network for Nanoscience Scanning Electron Microscope Image Recognition.

    Science.gov (United States)

    Modarres, Mohammad Hadi; Aversa, Rossella; Cozzini, Stefano; Ciancio, Regina; Leto, Angelo; Brandino, Giuseppe Piero

    2017-10-16

    In this paper we applied transfer learning techniques for image recognition, automatic categorization, and labeling of nanoscience images obtained by scanning electron microscope (SEM). Roughly 20,000 SEM images were manually classified into 10 categories to form a labeled training set, which can be used as a reference set for future applications of deep learning enhanced algorithms in the nanoscience domain. The categories chosen spanned the range of 0-Dimensional (0D) objects such as particles, 1D nanowires and fibres, 2D films and coated surfaces, and 3D patterned surfaces such as pillars. The training set was used to retrain on the SEM dataset and to compare many convolutional neural network models (Inception-v3, Inception-v4, ResNet). We obtained compatible results by performing a feature extraction of the different models on the same dataset. We performed additional analysis of the classifier on a second test set to further investigate the results both on particular cases and from a statistical point of view. Our algorithm was able to successfully classify around 90% of a test dataset consisting of SEM images, while reduced accuracy was found in the case of images at the boundary between two categories or containing elements of multiple categories. In these cases, the image classification did not identify a predominant category with a high score. We used the statistical outcomes from testing to deploy a semi-automatic workflow able to classify and label images generated by the SEM. Finally, a separate training was performed to determine the volume fraction of coherently aligned nanowires in SEM images. The results were compared with what was obtained using the Local Gradient Orientation method. This example demonstrates the versatility and the potential of transfer learning to address specific tasks of interest in nanoscience applications.

  2. GPM GROUND VALIDATION CONICAL SCANNING MILLIMETER-WAVE IMAGING RADIOMETER (COSMIR) MC3E V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The GPM Ground Validation Conical Scanning Millimeter-wave Imaging Radiometer (COSMIR) MC3E dataset used the Conical Scanning Millimeter-wave Imaging Radiometer...

  3. GPM GROUND VALIDATION CONICAL SCANNING MILLIMETER-WAVE IMAGING RADIOMETER (COSMIR) GCPEX V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The GPM Ground Validation Conical Scanning Millimeter-wave Imaging Radiometer (COSMIR) GCPEx dataset used the Conical Scanning Millimeter-wave Imaging Radiometer...

  4. A novel near real-time laser scanning device for geometrical determination of pleural cavity surface.

    Science.gov (United States)

    Kim, Michele M; Zhu, Timothy C

    2013-02-02

    During HPPH-mediated pleural photodynamic therapy (PDT), it is critical to determine the anatomic geometry of the pleural surface quickly as there may be movement during treatment resulting in changes with the cavity. We have developed a laser scanning device for this purpose, which has the potential to obtain the surface geometry in real-time. A red diode laser with a holographic template to create a pattern and a camera with auto-focusing abilities are used to scan the cavity. In conjunction with a calibration with a known surface, we can use methods of triangulation to reconstruct the surface. Using a chest phantom, we are able to obtain a 360 degree scan of the interior in under 1 minute. The chest phantom scan was compared to an existing CT scan to determine its accuracy. The laser-camera separation can be determined through the calibration with 2mm accuracy. The device is best suited for environments that are on the scale of a chest cavity (between 10cm and 40cm). This technique has the potential to produce cavity geometry in real-time during treatment. This would enable PDT treatment dosage to be determined with greater accuracy. Works are ongoing to build a miniaturized device that moves the light source and camera via a fiber-optics bundle commonly used for endoscopy with increased accuracy.

  5. Scanning and/or treating surface device for weak bending radius cylindrical airlock

    International Nuclear Information System (INIS)

    Gemma, A.

    1988-01-01

    The device for scanning or treating the surface of a weak bending cylindrical airlock has a support mounted on the airlock outside flange, a central mast perpendicular to the support mounted to rotate about its axis, a geared motor turning the mast, an exploration or treatment tool fixed to the mast and a controller for the motor and the tool [fr

  6. 76 FR 52970 - In the Matter of Certain Biometric Scanning Devices, Components Thereof, Associated Software, and...

    Science.gov (United States)

    2011-08-24

    ... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-720] In the Matter of Certain Biometric... 17, 2010 based on a complaint filed on May 11, 2010, by Cross Match Technologies, Inc. (``Cross Match... certain biometric scanning devices, components thereof, associated software, and products containing the...

  7. 75 FR 34482 - Certain Biometric Scanning Devices, Components Thereof, Associated Software, and Products...

    Science.gov (United States)

    2010-06-17

    ... INTERNATIONAL TRADE COMMISSION [Inv. No. 337-TA-720] Certain Biometric Scanning Devices... Cross Match Technologies, Inc. of Palm Beach Gardens, Florida. An amended complaint was filed on May 26..., the sale for importation, and the sale within the United States after importation of certain biometric...

  8. Vortex imaging in superconducting films by scanning Hall probe microscopy

    International Nuclear Information System (INIS)

    Oral, A.; Bending, S.J.; Humphreys, R.G.

    1996-01-01

    The authors have used a low noise Scanning Hall Probe Microscope (SHPM) to study vortex structures in superconducting films. The microscope has high magnetic field (∼2.9 x 10 -8 T/√Hz at 77K) and spatial resolution, ∼0.85 μm. Magnetic field profiles of single vortices in High T c YBa 2 Cu 3 O 7-δ thin films have been successfully measured and the microscopic penetration depth of the superconductor has been extracted as a function of temperature. Flux penetration into the superconductor has been imaged in real time (∼8s/frame)

  9. A scanning point source for quality control of FOV uniformity in GC-PET imaging

    International Nuclear Information System (INIS)

    Bergmann, H.; Minear, G.; Dobrozemsky, G.; Nowotny, R.; Koenig, B.

    2002-01-01

    Aim: PET imaging with coincidence cameras (GC-PET) requires additional quality control procedures to check the function of coincidence circuitry and detector zoning. In particular, the uniformity response over the field of view needs special attention since it is known that coincidence counting mode may suffer from non-uniformity effects not present in single photon mode. Materials and methods: An inexpensive linear scanner with a stepper motor and a digital interface to a PC with software allowing versatile scanning modes was developed. The scanner is used with a source holder containing a Sodium-22 point source. While moving the source along the axis of rotation of the GC-PET system, a tomographic acquisition takes place. The scan covers the full axial field of view of the 2-D or 3-D scatter frame. Depending on the acquisition software, point source scanning takes place continuously while only one projection is acquired or is done in step-and-shoot mode with the number of positions equal to the number of gantry steps. Special software was developed to analyse the resulting list mode acquisition files and to produce an image of the recorded coincidence events of each head. Results: Uniformity images of coincidence events were obtained after further correction for systematic sensitivity variations caused by acquisition geometry. The resulting images are analysed visually and by calculating NEMA uniformity indices as for a planar flood field. The method has been applied successfully to two different brands of GC-PET capable gamma cameras. Conclusion: Uniformity of GC-PET can be tested quickly and accurately with a routine QC procedure, using a Sodium-22 scanning point source and an inexpensive mechanical scanning device. The method can be used for both 2-D and 3-D acquisition modes and fills an important gap in the quality control system for GC-PET

  10. Scanning tomographic particle image velocimetry applied to a turbulent jet

    KAUST Repository

    Casey, T. A.

    2013-02-21

    We introduce a modified tomographic PIV technique using four high-speed video cameras and a scanning pulsed laser-volume. By rapidly illuminating adjacent subvolumes onto separate video frames, we can resolve a larger total volume of velocity vectors, while retaining good spatial resolution. We demonstrate this technique by performing time-resolved measurements of the turbulent structure of a round jet, using up to 9 adjacent volume slices. In essence this technique resolves more velocity planes in the depth direction by maintaining optimal particle image density and limiting the number of ghost particles. The total measurement volumes contain between 1 ×106 and 3 ×106 velocity vectors calculated from up to 1500 reconstructed depthwise image planes, showing time-resolved evolution of the large-scale vortical structures for a turbulent jet of Re up to 10 000.

  11. Pavement cracking measurements using 3D laser-scan images

    International Nuclear Information System (INIS)

    Ouyang, W; Xu, B

    2013-01-01

    Pavement condition surveying is vital for pavement maintenance programs that ensure ride quality and traffic safety. This paper first introduces an automated pavement inspection system which uses a three-dimensional (3D) camera and a structured laser light to acquire dense transverse profiles of a pavement lane surface when it carries a moving vehicle. After the calibration, the 3D system can yield a depth resolution of 0.5 mm and a transverse resolution of 1.56 mm pixel −1 at 1.4 m camera height from the ground. The scanning rate of the camera can be set to its maximum at 5000 lines s −1 , allowing the density of scanned profiles to vary with the vehicle's speed. The paper then illustrates the algorithms that utilize 3D information to detect pavement distress, such as transverse, longitudinal and alligator cracking, and presents the field tests on the system's repeatability when scanning a sample pavement in multiple runs at the same vehicle speed, at different vehicle speeds and under different weather conditions. The results show that this dedicated 3D system can capture accurate pavement images that detail surface distress, and obtain consistent crack measurements in repeated tests and under different driving and lighting conditions. (paper)

  12. Tiny Devices Project Sharp, Colorful Images

    Science.gov (United States)

    2009-01-01

    Displaytech Inc., based in Longmont, Colorado and recently acquired by Micron Technology Inc. of Boise, Idaho, first received a Small Business Innovation Research contract in 1993 from Johnson Space Center to develop tiny, electronic, color displays, called microdisplays. Displaytech has since sold over 20 million microdisplays and was ranked one of the fastest growing technology companies by Deloitte and Touche in 2005. Customers currently incorporate the microdisplays in tiny pico-projectors, which weigh only a few ounces and attach to media players, cell phones, and other devices. The projectors can convert a digital image from the typical postage stamp size into a bright, clear, four-foot projection. The company believes sales of this type of pico-projector may exceed $1.1 billion within 5 years.

  13. Signal Normalization Reduces Image Appearance Disparity Among Multiple Optical Coherence Tomography Devices.

    Science.gov (United States)

    Chen, Chieh-Li; Ishikawa, Hiroshi; Wollstein, Gadi; Bilonick, Richard A; Kagemann, Larry; Schuman, Joel S

    2017-02-01

    To assess the effect of the previously reported optical coherence tomography (OCT) signal normalization method on reducing the discrepancies in image appearance among spectral-domain OCT (SD-OCT) devices. Healthy eyes and eyes with various retinal pathologies were scanned at the macular region using similar volumetric scan patterns with at least two out of three SD-OCT devices at the same visit (Cirrus HD-OCT, Zeiss, Dublin, CA; RTVue, Optovue, Fremont, CA; and Spectralis, Heidelberg Engineering, Heidelberg, Germany). All the images were processed with the signal normalization. A set of images formed a questionnaire with 24 pairs of cross-sectional images from each eye with any combination of the three SD-OCT devices either both pre- or postsignal normalization. Observers were asked to evaluate the similarity of the two displayed images based on the image appearance. The effects on reducing the differences in image appearance before and after processing were analyzed. Twenty-nine researchers familiar with OCT images participated in the survey. Image similarity was significantly improved after signal normalization for all three combinations ( P ≤ 0.009) as Cirrus and RTVue combination became the most similar pair, followed by Cirrus and Spectralis, and RTVue and Spectralis. The signal normalization successfully minimized the disparities in the image appearance among multiple SD-OCT devices, allowing clinical interpretation and comparison of OCT images regardless of the device differences. The signal normalization would enable direct OCT images comparisons without concerning about device differences and broaden OCT usage by enabling long-term follow-ups and data sharing.

  14. Optimization of the imaging response of scanning microwave microscopy measurements

    Energy Technology Data Exchange (ETDEWEB)

    Sardi, G. M.; Lucibello, A.; Proietti, E.; Marcelli, R., E-mail: romolo.marcelli@imm.cnr.it [National Research Council, Institute for Microelectronics and Microsystems, Via del Fosso del Cavaliere 100, 00133 Rome (Italy); Kasper, M.; Gramse, G. [Biophysics Institute, Johannes Kepler University, Gruberstrasse 40, 4020 Linz (Austria); Kienberger, F. [Keysight Technologies Austria GmbH, Gruberstrasse 40, 4020 Linz (Austria)

    2015-07-20

    In this work, we present the analytical modeling and preliminary experimental results for the choice of the optimal frequencies when performing amplitude and phase measurements with a scanning microwave microscope. In particular, the analysis is related to the reflection mode operation of the instrument, i.e., the acquisition of the complex reflection coefficient data, usually referred as S{sub 11}. The studied configuration is composed of an atomic force microscope with a microwave matched nanometric cantilever probe tip, connected by a λ/2 coaxial cable resonator to a vector network analyzer. The set-up is provided by Keysight Technologies. As a peculiar result, the optimal frequencies, where the maximum sensitivity is achieved, are different for the amplitude and for the phase signals. The analysis is focused on measurements of dielectric samples, like semiconductor devices, textile pieces, and biological specimens.

  15. Multimodality imaging of the Essure tubal occlusion device

    International Nuclear Information System (INIS)

    Simpson, W.L.; Beitia, L.

    2012-01-01

    The Essure device is a permanent birth-control device, which is gaining popularity. The micro-inserts are composed of metallic elements that can be seen on radiography, computed tomography, ultrasound, and magnetic resonance imaging. Knowledge of the normal location and appearance of the Essure device will ensure appropriate patient care. The purpose of this review is to describe the Essure tubal occlusion device and illustrate its normal and abnormal appearance using various imaging methods.

  16. Measuring a narrow Bessel beam spot by scanning a charge-coupled device (CCD) pixel

    International Nuclear Information System (INIS)

    Tiwari, S K; Ram, S P; Jayabalan, J; Mishra, S R

    2010-01-01

    By scanning a charge-coupled device (CCD) camera transverse to the beam axis and observing the variation in counts on a marked pixel, we demonstrate that we can measure a laser beam spot size smaller than the size of the CCD-pixel. We find this method particularly attractive for measuring the size of central spot of a Bessel beam, for which the established scanning knife-edge method does not work appropriately because of the large contribution of the rings surrounding the central spot to the signal

  17. Image processing based detection of lung cancer on CT scan images

    Science.gov (United States)

    Abdillah, Bariqi; Bustamam, Alhadi; Sarwinda, Devvi

    2017-10-01

    In this paper, we implement and analyze the image processing method for detection of lung cancer. Image processing techniques are widely used in several medical problems for picture enhancement in the detection phase to support the early medical treatment. In this research we proposed a detection method of lung cancer based on image segmentation. Image segmentation is one of intermediate level in image processing. Marker control watershed and region growing approach are used to segment of CT scan image. Detection phases are followed by image enhancement using Gabor filter, image segmentation, and features extraction. From the experimental results, we found the effectiveness of our approach. The results show that the best approach for main features detection is watershed with masking method which has high accuracy and robust.

  18. Imaging of current density distributions with a Nb weak-link scanning nano-SQUID microscope

    Science.gov (United States)

    Shibata, Yusuke; Nomura, Shintaro; Kashiwaya, Hiromi; Kashiwaya, Satoshi; Ishiguro, Ryosuke; Takayanagi, Hideaki

    2015-10-01

    Superconducting quantum interference devices (SQUIDs) are accepted as one of the highest magnetic field sensitive probes. There are increasing demands to image local magnetic fields to explore spin properties and current density distributions in a two-dimensional layer of semiconductors or superconductors. Nano-SQUIDs have recently attracting much interest for high spatial resolution measurements in nanometer-scale samples. Whereas weak-link Dayem Josephson junction nano-SQUIDs are suitable to miniaturization, hysteresis in current-voltage (I-V) characteristics that is often observed in Dayem Josephson junction is not desirable for a scanning microscope. Here we report on our development of a weak-link nano-SQUIDs scanning microscope with small hysteresis in I-V curve and on reconstructions of two-dimensional current density vector in two-dimensional electron gas from measured magnetic field.

  19. Scanning electron microscopy physics of image formation and microanalysis

    CERN Document Server

    Reimer, Ludwig

    1985-01-01

    The aim of this book is to outline the physics of image formation, electron­ specimen interactions, imaging modes, the interpretation of micrographs and the use of quantitative modes "in scanning electron microscopy (SEM). lt forms a counterpart to Transmission Electron Microscopy (Vol. 36 of this Springer Series in Optical Sciences) . The book evolved from lectures delivered at the University of Münster and from a German text entitled Raster-Elektronenmikroskopie (Springer-Verlag), published in collaboration with my colleague Gerhard Pfefferkorn. In the introductory chapter, the principles of the SEM and of electron­ specimen interactions are described, the most important imaging modes and their associated contrast are summarized, and general aspects of eiemental analysis by x-ray and Auger electron emission are discussed. The electron gun and electron optics are discussed in Chap. 2 in order to show how an electron probe of small diameter can be formed, how the elec­ tron beam can be blanked at high fre...

  20. A high-stability scanning tunneling microscope achieved by an isolated tiny scanner with low voltage imaging capability

    International Nuclear Information System (INIS)

    Wang, Qi; Wang, Junting; Lu, Qingyou; Hou, Yubin

    2013-01-01

    We present a novel homebuilt scanning tunneling microscope (STM) with high quality atomic resolution. It is equipped with a small but powerful GeckoDrive piezoelectric motor which drives a miniature and detachable scanning part to implement coarse approach. The scanning part is a tiny piezoelectric tube scanner (industry type: PZT-8, whose d 31 coefficient is one of the lowest) housed in a slightly bigger polished sapphire tube, which is riding on and spring clamped against the knife edges of a tungsten slot. The STM so constructed shows low back-lashing and drifting and high repeatability and immunity to external vibrations. These are confirmed by its low imaging voltages, low distortions in the spiral scanned images, and high atomic resolution quality even when the STM is placed on the ground of the fifth floor without any external or internal vibration isolation devices

  1. A high-stability scanning tunneling microscope achieved by an isolated tiny scanner with low voltage imaging capability.

    Science.gov (United States)

    Wang, Qi; Hou, Yubin; Wang, Junting; Lu, Qingyou

    2013-11-01

    We present a novel homebuilt scanning tunneling microscope (STM) with high quality atomic resolution. It is equipped with a small but powerful GeckoDrive piezoelectric motor which drives a miniature and detachable scanning part to implement coarse approach. The scanning part is a tiny piezoelectric tube scanner (industry type: PZT-8, whose d31 coefficient is one of the lowest) housed in a slightly bigger polished sapphire tube, which is riding on and spring clamped against the knife edges of a tungsten slot. The STM so constructed shows low back-lashing and drifting and high repeatability and immunity to external vibrations. These are confirmed by its low imaging voltages, low distortions in the spiral scanned images, and high atomic resolution quality even when the STM is placed on the ground of the fifth floor without any external or internal vibration isolation devices.

  2. A high-stability scanning tunneling microscope achieved by an isolated tiny scanner with low voltage imaging capability

    Science.gov (United States)

    Wang, Qi; Hou, Yubin; Wang, Junting; Lu, Qingyou

    2013-11-01

    We present a novel homebuilt scanning tunneling microscope (STM) with high quality atomic resolution. It is equipped with a small but powerful GeckoDrive piezoelectric motor which drives a miniature and detachable scanning part to implement coarse approach. The scanning part is a tiny piezoelectric tube scanner (industry type: PZT-8, whose d31 coefficient is one of the lowest) housed in a slightly bigger polished sapphire tube, which is riding on and spring clamped against the knife edges of a tungsten slot. The STM so constructed shows low back-lashing and drifting and high repeatability and immunity to external vibrations. These are confirmed by its low imaging voltages, low distortions in the spiral scanned images, and high atomic resolution quality even when the STM is placed on the ground of the fifth floor without any external or internal vibration isolation devices.

  3. Note: Automated optical focusing on encapsulated devices for scanning light stimulation systems

    International Nuclear Information System (INIS)

    Bitzer, L. A.; Benson, N.; Schmechel, R.

    2014-01-01

    Recently, a scanning light stimulation system with an automated, adaptive focus correction during the measurement was introduced. Here, its application on encapsulated devices is discussed. This includes the changes an encapsulating optical medium introduces to the focusing process as well as to the subsequent light stimulation measurement. Further, the focusing method is modified to compensate for the influence of refraction and to maintain a minimum beam diameter on the sample surface

  4. PINPIN a-Si:H based structures for X-ray image detection using the laser scanning technique

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, M., E-mail: mfernandes@isel.pt [Electronics Telecommunication and Computer Dept., ISEL, R.Conselheiro Emídio Navarro, 1959-007 Lisboa (Portugal); CTS-UNINOVA Quinta da Torre, Monte da Caparica, 2829-516 Caparica (Portugal); Vygranenko, Y.; Vieira, M. [Electronics Telecommunication and Computer Dept., ISEL, R.Conselheiro Emídio Navarro, 1959-007 Lisboa (Portugal); CTS-UNINOVA Quinta da Torre, Monte da Caparica, 2829-516 Caparica (Portugal)

    2015-05-01

    Highlights: • We present novel structure for X-ray image sensor based on the laser scanned technique. • Amorphous silicon based tandem structure characterization results are presented and discussed. • Results from preliminary tests of the imaging application are promising for very large area image sensing. - Abstract: Conventional film based X-ray imaging systems are being replaced by their digital equivalents. Different approaches are being followed by considering direct or indirect conversion, with the later technique dominating. The typical, indirect conversion, X-ray panel detector uses a phosphor for X-ray conversion coupled to a large area array of amorphous silicon based optical sensors and a couple of switching thin film transistors (TFT). The pixel information can then be readout by switching the correspondent line and column transistors, routing the signal to an external amplifier. In this work we follow an alternative approach, where the electrical switching performed by the TFT is replaced by optical scanning using a low power laser beam and a sensing/switching PINPIN structure, thus resulting in a simpler device. The optically active device is a PINPIN array, sharing both front and back electrical contacts, deposited over a glass substrate. During X-ray exposure, each sensing side photodiode collects photons generated by the scintillator screen (560 nm), charging its internal capacitance. Subsequently a laser beam (445 nm) scans the switching diodes (back side) retrieving the stored charge in a sequential way, reconstructing the image. In this paper we present recent work on the optoelectronic characterization of the PINPIN structure to be incorporated in the X-ray image sensor. The results from the optoelectronic characterization of the device and the dependence on scanning beam parameters are presented and discussed. Preliminary results of line scans are also presented.

  5. PINPIN a-Si:H based structures for X-ray image detection using the laser scanning technique

    Science.gov (United States)

    Fernandes, M.; Vygranenko, Y.; Vieira, M.

    2015-05-01

    Conventional film based X-ray imaging systems are being replaced by their digital equivalents. Different approaches are being followed by considering direct or indirect conversion, with the later technique dominating. The typical, indirect conversion, X-ray panel detector uses a phosphor for X-ray conversion coupled to a large area array of amorphous silicon based optical sensors and a couple of switching thin film transistors (TFT). The pixel information can then be readout by switching the correspondent line and column transistors, routing the signal to an external amplifier. In this work we follow an alternative approach, where the electrical switching performed by the TFT is replaced by optical scanning using a low power laser beam and a sensing/switching PINPIN structure, thus resulting in a simpler device. The optically active device is a PINPIN array, sharing both front and back electrical contacts, deposited over a glass substrate. During X-ray exposure, each sensing side photodiode collects photons generated by the scintillator screen (560 nm), charging its internal capacitance. Subsequently a laser beam (445 nm) scans the switching diodes (back side) retrieving the stored charge in a sequential way, reconstructing the image. In this paper we present recent work on the optoelectronic characterization of the PINPIN structure to be incorporated in the X-ray image sensor. The results from the optoelectronic characterization of the device and the dependence on scanning beam parameters are presented and discussed. Preliminary results of line scans are also presented.

  6. Fabrication of Gate-tunable Graphene Devices for Scanning Tunneling Microscopy Studies with Coulomb Impurities

    Science.gov (United States)

    Jung, Han Sae; Tsai, Hsin-Zon; Wong, Dillon; Germany, Chad; Kahn, Salman; Kim, Youngkyou; Aikawa, Andrew S.; Desai, Dhruv K.; Rodgers, Griffin F.; Bradley, Aaron J.; Velasco, Jairo; Watanabe, Kenji; Taniguchi, Takashi; Wang, Feng; Zettl, Alex; Crommie, Michael F.

    2015-01-01

    Owing to its relativistic low-energy charge carriers, the interaction between graphene and various impurities leads to a wealth of new physics and degrees of freedom to control electronic devices. In particular, the behavior of graphene’s charge carriers in response to potentials from charged Coulomb impurities is predicted to differ significantly from that of most materials. Scanning tunneling microscopy (STM) and scanning tunneling spectroscopy (STS) can provide detailed information on both the spatial and energy dependence of graphene's electronic structure in the presence of a charged impurity. The design of a hybrid impurity-graphene device, fabricated using controlled deposition of impurities onto a back-gated graphene surface, has enabled several novel methods for controllably tuning graphene’s electronic properties.1-8 Electrostatic gating enables control of the charge carrier density in graphene and the ability to reversibly tune the charge2 and/or molecular5 states of an impurity. This paper outlines the process of fabricating a gate-tunable graphene device decorated with individual Coulomb impurities for combined STM/STS studies.2-5 These studies provide valuable insights into the underlying physics, as well as signposts for designing hybrid graphene devices. PMID:26273961

  7. A novel and compact nanoindentation device for in situ nanoindentation tests inside the scanning electron microscope

    Directory of Open Access Journals (Sweden)

    Hu Huang

    2012-03-01

    Full Text Available In situ nanomechanical tests provide a unique insight into mechanical behaviors of materials, such as fracture onset and crack propagation, shear band formation and so on. This paper presents a novel in situ nanoindentation device with dimensions of 103mm×74mm×60mm. Integrating the stepper motor, the piezoelectric actuator and the flexure hinge, the device can realize coarse adjustment of the specimen and precision loading and unloading of the indenter automatically. A novel indenter holder was designed to guarantee that the indenter penetrates into and withdraws from the specimen surface vertically. Closed-loop control of the indentation process was established to solve the problem of nonlinearity of the piezoelectric actuator and to enrich the loading modes. The in situ indentation test of Indium Phosphide (InP inside the scanning electron microscope (SEM was carried out and the experimental result indicates the feasibility of the developed device.

  8. NATO Advanced Study Institute on Scanning Probe Microscopy : Characterization, Nanofabrication and Device Application of Functional Materials

    CERN Document Server

    Vilarinho, Paula Maria; Kingon, Angus; Scanning Probe Microscopy : Characterization, Nanofabrication and Device Application of Functional Materials

    2005-01-01

    As the characteristic dimensions of electronic devices continue to shrink, the ability to characterize their electronic properties at the nanometer scale has come to be of outstanding importance. In this sense, Scanning Probe Microscopy (SPM) is becoming an indispensable tool, playing a key role in nanoscience and nanotechnology. SPM is opening new opportunities to measure semiconductor electronic properties with unprecedented spatial resolution. SPM is being successfully applied for nanoscale characterization of ferroelectric thin films. In the area of functional molecular materials it is being used as a probe to contact molecular structures in order to characterize their electrical properties, as a manipulator to assemble nanoparticles and nanotubes into simple devices, and as a tool to pattern molecular nanostructures. This book provides in-depth information on new and emerging applications of SPM to the field of materials science, namely in the areas of characterisation, device application and nanofabrica...

  9. A quantitative image quality comparison of four different image guided radiotherapy devices

    International Nuclear Information System (INIS)

    Stuetzel, Julia; Oelfke, Uwe; Nill, Simeon

    2008-01-01

    Purpose: A study to quantitatively compare the image quality of four different image guided radiotherapy (IGRT) devices based on phantom measurements with respect to the additional dose delivered to the patient. Methods: Images of three different head-sized phantoms (diameter 16-18 cm) were acquired with the following four IGRT-CT solutions: (i) the Siemens Primatom single slice fan beam computed tomography (CT) scanner with an acceleration voltage of 130 kV, (ii) a Tomotherapy HI-ART II unit using a fan beam scanner with an energy of 3.5 MeV and (iii) the Siemens Artiste prototype, providing the possibility to perform kV (121 kV) and MV (6 MV) cone beam (CB) CTs. For each device three scan protocols (named low, normal, high) were selected to yield the same weighted computed tomography dose index (CTDI w ). Based on the individual inserts of the different phantoms the image quality achieved with each device at a certain dose level was characterized in terms of homogeneity, spatial resolution, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and electron density-to-CT-number conversion. Results: Based on the current findings for head-sized phantoms all devices show an electron density-to-CT-number conversion almost independent of the imaging parameters and hence can be suited for treatment planning purposes. The evaluation of the image quality, however, points out clear differences due to the different energies and geometries. The Primatom standard CT scanner shows throughout the best performance, especially for soft tissue contrast and spatial resolution with low imaging doses. Reasonable soft tissue contrast can be obtained with slightly higher doses compared to the CT scanner with the kVCB and the Tomotherapy unit. In order to get similar results with the MVCB system a much higher dose needs to be applied to the patient. Conclusion: Considering the entire investigations, especially in terms of contrast and spatial resolution, a rough tendency for

  10. The fusion of large scale classified side-scan sonar image mosaics.

    Science.gov (United States)

    Reed, Scott; Tena, Ruiz Ioseba; Capus, Chris; Petillot, Yvan

    2006-07-01

    This paper presents a unified framework for the creation of classified maps of the seafloor from sonar imagery. Significant challenges in photometric correction, classification, navigation and registration, and image fusion are addressed. The techniques described are directly applicable to a range of remote sensing problems. Recent advances in side-scan data correction are incorporated to compensate for the sonar beam pattern and motion of the acquisition platform. The corrected images are segmented using pixel-based textural features and standard classifiers. In parallel, the navigation of the sonar device is processed using Kalman filtering techniques. A simultaneous localization and mapping framework is adopted to improve the navigation accuracy and produce georeferenced mosaics of the segmented side-scan data. These are fused within a Markovian framework and two fusion models are presented. The first uses a voting scheme regularized by an isotropic Markov random field and is applicable when the reliability of each information source is unknown. The Markov model is also used to inpaint regions where no final classification decision can be reached using pixel level fusion. The second model formally introduces the reliability of each information source into a probabilistic model. Evaluation of the two models using both synthetic images and real data from a large scale survey shows significant quantitative and qualitative improvement using the fusion approach.

  11. New approach towards imaging -DNA using scanning tunneling

    Indian Academy of Sciences (India)

    DNA; scanning tunneling microscopy; Langmuir Blodget technique; silanization. ... Scanning tunneling spectroscopy (STS) at different stages depict a broad distribution of defect states in the bandgap region of -Si(111) which ... Current Issue

  12. Magnetic imaging of unconventional superconductors by scanning SQUID microscopy

    International Nuclear Information System (INIS)

    Hykel, D.

    2011-01-01

    We present the development of a scanning SQUID/AFM microscope and measurements performed on different samples. The microscope can take topographic and magnetic images simultaneously. The magnetic resolution is of the order of 10 -4 Φ 0 √Hz and the spatial resolution of the SQUIDs used in this thesis goes up to 600 nm. The scanning range is 70 μm * 85 μm. The temperature range accessible is between 200 mK and 10 K at the time of writing. Measurements on a thin rhenium film (80 nm) give an estimate of the minimal pinning force of a vortex of about 3.9 * 10 -16 N. Furthermore, the penetration depth λ on this sample was determined as a function of temperature. For T → 0, λ →79 nm. We have for the first time shown local measurements of the domain structure of the superconducting ferromagnet UCoGe and determined the average domain size in the virgin state (10 μm). By magnetic imaging we were capable of determining the magnetic field difference above opposite domains along the c-axis to be 45 G and 16 G along the b-axis. Due to these magnetic field measurements we were able to give an upper limit for the domain wall width (∼ 1μm) and domain reconstruction depth (100 nm). This is supported by simple calculations leading to a domain wall width of several angstroms. Thus UCoGe can be considered an ideal Ising ferromagnet. Different possible domain structures for an Ising ferromagnet have been discussed. The complicated domain structure found in the zero field cooled virgin state corresponds to up domains embedded in larger down domains and vice versa. We have shown evidence for coexistence of superconductivity and ferromagnetism. The weak Meissner effect can be explained by a spontaneous vortex state, put forward by other groups. Numerical simulations suggest that the strong magnetic background signal and the limited spatial and magnetic resolution of the used SQUID made it difficult to resolve the expected spontaneous vortex state. The relaxation of the

  13. Laser scanning endoscope via an imaging fiber bundle for fluorescence imaging

    Science.gov (United States)

    Yeboah, Lorenz D.; Nestler, Dirk; Steiner, Rudolf W.

    1994-12-01

    Based on a laser scanning endoscope via an imaging fiber bundle, a new approach for a tumor diagnostic system has been developed to assist physicians in the diagnosis before the actual PDT is carried out. Laser induced, spatially resolved fluorescence images of diseased tissue can be compared with images received by video endoscopy using a white light source. The set- up is required to produce a better contrast between infected and healthy tissue and might serve as a constructive diagnostic help for surgeons. The fundamental idea is to scan a low-power laser beam on an imaging fiber bundle and to achieve a spatially resolved projection on the tissue surface. A sufficiently high laser intensity from the diode laser is concentrated on each single spot of the tissue exciting fluorescence when a dye has previously been accumulated. Subsequently, video image of the tissue is recorded and stored. With an image processing unit, video and fluorescence images are overlaid producing a picture of the fluorescence intensity in the environment of the observed tissue.

  14. Contribution of brain imaging techniques: CT-scan and magnetic resonance imaging (MRI)

    International Nuclear Information System (INIS)

    Pasco-Papon, A.; Gourdier, A.L.; Papon, X.; Caron-Poitreau, C.

    1996-01-01

    In light of the current lack of consensus on the benefit of carotid artery surgery to treat asymptomatic carotid artery stenosis, the decision to operate on a patient depends on individual evaluation and characterization of risk factors on carotid artery stenosis greater than 70 %. The assessment of such risk factors is based especially on non-invasive brain imaging techniques.Computed tomography scanning (CT-scan) and magnetic resonance imaging (MRI) enable two types of stenosis to be differentiated, i.e. stenoses which are symptomatic and those that are radiologically proven versus those which are clinically and radiologically silent. CT-scan investigation (with and without injection of iodinated contrast media) still continues to be a common routine test in 1996 whenever a surgical revascularization procedure is planned. The presence of deep lacunar infarcts ipsilateral to the carotid artery stenosis generally evidence the reality of stenosis and thus are useful to the surgeon in establishing whether surgery is indicated. In the absence a consensus on indications for surgical management, the surgeon could use the CT-scan and MRI as medicolegal records which could be compared to a subsequent postoperative CT-scan in case of ischemic complications associated with the surgical procedure. Furthermore, recent cerebral ischemia as evidenced by filling with contrast material, will call for postponing treatment by a few weeks. Although conventional MRI is more contributive than brain CT-scan in terms of sensibility and specificity, its indications are narrower because of its limited availability and cost constraints. But, development of angio-MRI and functional imaging promise that its future is assured and even perhaps as the sole diagnostic method if its indications are expanded to include preoperative angiographic evaluation of atheromatous lesions of supra-aortic trunks. (authors). 37 refs

  15. Scan-Less Line Field Optical Coherence Tomography, with Automatic Image Segmentation, as a Measurement Tool for Automotive Coatings

    Directory of Open Access Journals (Sweden)

    Samuel Lawman

    2017-04-01

    Full Text Available The measurement of the thicknesses of layers is important for the quality assurance of industrial coating systems. Current measurement techniques only provide a limited amount of information. Here, we show that spectral domain Line Field (LF Optical Coherence Tomography (OCT is able to return to the user a cross sectional B-Scan image in a single shot with no mechanical moving parts. To reliably extract layer thicknesses from such images of automotive paint systems, we present an automatic graph search image segmentation algorithm. To show that the algorithm works independently of the OCT device, the measurements are repeated with a separate time domain Full Field (FF OCT system. This gives matching mean thickness values within the standard deviations of the measured thicknesses across each B-Scan image. The combination of an LF-OCT with graph search segmentation is potentially a powerful technique for the quality assurance of non-opaque industrial coating layers.

  16. Development of a method of testing irradiation devices by gamma scanning inside a research nuclear reactor

    International Nuclear Information System (INIS)

    Michel, Francois.

    1975-01-01

    A tridimensional experiment of spectrometry of an irradiation device located inside the reactor Siloe at a place shielded against spurious radiations, is exposed. The automatic scanning system that was developed, makes it possible to fully analyze in about 24 hours, the irradiation device (fuel pin, coolant and structures). The process combined with a 'pre-processing' program allows first partial results to be simultaneously obtained, more refined results being achieved during the next week, using the 'heavy processing'. The irradiation of the device is only interrupted during the compelling duty shutdown of the reactor, the evolution of the device during the successive irradiation cycles being thus followed up without pertubing said evolution. The reproducibility was studied at a local stage for testing the collimation of the detection unit (1% accuracy) and for testing the whole set 'processing measurement and computation' (5% accuracy). The sensitivity has been illustrated by detecting and measuring local singularities inside fuel (pellets), determining the detection efficiency dependence on the radial distribution of fission products and measuring nucleides inside the coolant flow (limiting value 10 -7 ). The accuracy of the method is evaluated at 5% for relative measurement of an experimental device during its in-pile lifetime and as 10% for quantitative absolute measurements [fr

  17. Development of a human body RMN imaging device

    International Nuclear Information System (INIS)

    Saint-Jalmes, H.

    1984-03-01

    Imaging device for human body is studied in this thesis. The section images presented are got by a projection-reconstruction method associated to a section plane selection by an oscillating gradient application. Different stages of the machine development are presented: - design and calculation of a resistive magnet for very homogeneous field imaging - design of gradient coils for imaging magnets - realization of control and acquisition interfaces - realization of imaging software in real time [fr

  18. Trial making of a positive drawing phantom and its application to whole-body imaging devices

    International Nuclear Information System (INIS)

    Saegusa, Kenji; Arimizu, Noboru; Nakata, Tsuneo; Toyama, Haruo; Shiina, Isamu.

    1980-01-01

    In whole-body RI imaging, there are more instances of the positive pictures detecting the radioisotopes accumulating in morbid positions, such as Tc-99m bone scanning. The phantoms used to mutually compare RI imaging devices and to test their performance employ negative drawing targets embedded rather than positive ones. A simple positive drawing phantom has been made for trial, and applying this to whole-body scanning devices, the performance and the target drawing ability under different scanning conditions were comparatively examined. Though similar to Rollo's phantom, the phantom made for positive drawing uses acryl plate for its outer structure and target portions. The positive targets are cylindrical, and the diameters are 2, 4, 6, 8, 10, and 20 mm, and the subject contrasts are 5, 2, 1, 0.5 and 0.2. The aqueous solution of Tc-99m of about 2 mCi was injected into the phantom, and this was scanned with a whole-body camera and a multi-detector type whole-body scanner. With the phantom pictures close to actual clinical condition, the positive drawing phantom is conveniently capable of comparing the respective imaging devices for intended purposes. (J.P.N.)

  19. High contrast imaging and flexible photomanipulation for quantitative in vivo multiphoton imaging with polygon scanning microscope.

    Science.gov (United States)

    Li, Yongxiao; Montague, Samantha J; Brüstle, Anne; He, Xuefei; Gillespie, Cathy; Gaus, Katharina; Gardiner, Elizabeth E; Lee, Woei Ming

    2018-02-28

    In this study, we introduce two key improvements that overcome limitations of existing polygon scanning microscopes while maintaining high spatial and temporal imaging resolution over large field of view (FOV). First, we proposed a simple and straightforward means to control the scanning angle of the polygon mirror to carry out photomanipulation without resorting to high speed optical modulators. Second, we devised a flexible data sampling method directly leading to higher image contrast by over 2-fold and digital images with 100 megapixels (10 240 × 10 240) per frame at 0.25 Hz. This generates sub-diffraction limited pixels (60 nm per pixels over the FOV of 512 μm) which increases the degrees of freedom to extract signals computationally. The unique combined optical and digital control recorded fine fluorescence recovery after localized photobleaching (r ~10 μm) within fluorescent giant unilamellar vesicles and micro-vascular dynamics after laser-induced injury during thrombus formation in vivo. These new improvements expand the quantitative biological-imaging capacity of any polygon scanning microscope system. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Effect of Software Version on the Accuracy of an Intraoral Scanning Device.

    Science.gov (United States)

    Haddadi, Yasser; Bahrami, Golnosh; Isidor, Flemming

    2018-04-06

    To investigate the impact of software version on the accuracy of an intraoral scanning device. A master tooth was scanned with a high-precision optical scanner and then 10 times with a CEREC Omnicam scanner with software versions 4.4.0 and 4.4.4. Discrepancies were measured using quality control software. Mean deviation for 4.4.0 was 36.2 ± 35 μm and for 4.4.4 was 20.7 ± 14.2 μm (P ≤ .001). Software version has a significant impact on the accuracy of an intraoral scanner. It is important that researchers also publish the software version of scanners when publishing their findings.

  1. Multimodality imaging of the Essure tubal occlusion device.

    Science.gov (United States)

    Simpson, W L; Beitia, L

    2012-12-01

    The Essure device is a permanent birth-control device, which is gaining popularity. The micro-inserts are composed of metallic elements that can be seen on radiography, computed tomography, ultrasound, and magnetic resonance imaging. Knowledge of the normal location and appearance of the Essure device will ensure appropriate patient care. The purpose of this review is to describe the Essure tubal occlusion device and illustrate its normal and abnormal appearance using various imaging methods. Copyright © 2012 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  2. Confocal scanning microscopy with multiple optical probes for high speed measurements and better imaging

    Science.gov (United States)

    Chun, Wanhee; Lee, SeungWoo; Gweon, Dae-Gab

    2008-02-01

    Confocal scanning microscopy (CSM) needs a scanning mechanism because only one point information of specimen can be obtained. Therefore the speed of the confocal scanning microscopy is limited by the speed of the scanning tool. To overcome this limitation from scanning tool we propose another scanning mechanism. We make three optical probes in the specimen under confocal condition of each point. Three optical probes are moved by beam scanning mechanism with shared resonant scanning mirror (RM) and galvanometer driven mirror (GM). As each optical probe scan allocated region of the specimen, information from three points is obtained simultaneously and image acquisition time is reduced. Therefore confocal scanning microscopy with multiple optical probes is expected to have three times faster speed of the image acquisition than conventional one. And as another use, multiple optical probes to which different light wavelength is applied can scan whole same region respectively. It helps to obtain better contrast image in case of specimens having different optical characteristics for specific light wavelength. In conclusion confocal scanning microscopy with multiple optical probes is useful technique for views of image acquisition speed and image quality.

  3. Low cost, microcontroller based heating device for multi-wavelength differential scanning fluorimetry.

    Science.gov (United States)

    Hoeser, Jo; Gnandt, Emmanuel; Friedrich, Thorsten

    2018-01-23

    Differential scanning fluorimetry is a popular method to estimate the stability of a protein in distinct buffer conditions by determining its 'melting point'. The method requires a temperature controlled fluorescence spectrometer or a RT-PCR machine. Here, we introduce a low-budget version of a microcontroller based heating device implemented into a 96-well plate reader that is connected to a standard fluorescence spectrometer. We demonstrate its potential to determine the 'melting point' of soluble and membranous proteins at various buffer conditions.

  4. Implementation of synthetic aperture imaging on a hand-held device

    DEFF Research Database (Denmark)

    Hemmsen, Martin Christian; Kjeldsen, Thomas; Larsen, Lee

    2014-01-01

    -held devices all with different chipsets and a BK Medical UltraView 800 ultrasound scanner emulating a wireless probe. The wireless transmission is benchmarked using an imaging setup consisting of 269 scan lines x 1472 complex samples (1.58 MB pr. frame, 16 frames per second). The measured data throughput...... reached an average of 28.8 MB/s using a LG G2 mobile device, which is more than the required data throughput of 25.3 MB/s. Benchmarking the processing performance for B-mode imaging showed a total processing time of 18.9 ms (53 frames/s), which is less than the acquisition time (62.5 ms).......This paper presents several implementations of Syn- thetic Aperture Sequential Beamforming (SASB) on commer- cially available hand-held devices. The implementations include real-time wireless reception of ultrasound radio frequency sig- nals and GPU processing for B-mode imaging. The proposed...

  5. A study of metal artifacts on MR imaging. Evaluation of scanning parameters

    International Nuclear Information System (INIS)

    Yamashiro, Mitsuaki

    1999-01-01

    The purpose of this study was to evaluate scanning parameters on MR imaging for reducing metal artifacts using phantom study. Metal artifacts on sagittal images, perpendicular to static magnetic direction showed round shape in the relationship between shape of metal artifacts on MR images and scanning direction. Metal artifacts on both axial and coronal images, parallel to static magnetic direction showed oval shape in the direction of X-axis. In spin echo sequences, the largest dimension of metal artifacts was coronal image, followed by axial image and then sagittal image. In gradient echo sequences, the largest dimension of metal artifacts was axial image, followed by coronal image and then sagittal image. The best scanning plane for reducing metal artifacts was perpendicular to static magnetic direction. In scanning sequences, the largest dimensions of metal artifacts were gradient echo sequences, followed by T2-weighted spin echo sequence and then proton density-weighted and T1-weighted spin echo sequences. Large flip angle increased much metal artifacts on both axial and coronal images in gradient echo sequences. Small flip angle was useful for reducing metal artifacts on both axial and coronal images. The influence of flip angle on metal artifacts in sagittal images perpendicular static magnetic direction was less than for images in coronal and axial planes on gradient echo sequences. These results suggested that a study of metal artifacts on MR imaging about evaluation of scanning parameters was useful to reduce metal artifacts on MR images. (K.H.)

  6. Scanning high-Tc SQUID imaging system for magnetocardiography

    International Nuclear Information System (INIS)

    Yang, H-C; Wu, T-Y; Horng, H-E; Wu, C-C; Yang, S Y; Liao, S-H; Wu, C-H; Jeng, J T; Chen, J C; Chen, Kuen-Lin; Chen, M J

    2006-01-01

    A scanning magnetocardiography (MCG) system constructed from SQUID sensors offers potential to basic or clinical research in biomagnetism. In this work, we study a first order scanning electronic high-T c (HTS) SQUID MCG system for biomagnetic signals. The scanning MCG system was equipped with an x-y translation bed powered by step motors. Using noise cancellation and μ-metal shielding, we reduced the noise level substantially. The established scanning HTS MCG system was used to study the magnetophysiology of hypercholesterolaemic (HC) rabbits. The MCG data of HC rabbits were analysed. The MCG contour map of HC rabbits provides experimental models for the interpretation of human cardiac patterns

  7. Microscopic image processing system for measuring nonuniform film thickness profiles: Image scanning ellipsometry

    International Nuclear Information System (INIS)

    Liu, A.H.; Plawsky, J.L.; Wayner, P.C. Jr.

    1993-01-01

    The long-term objective of this research program is to determine the stability and heat transfer characteristics of evaporating thin films. The current objective is to develop and use a microscopic image-processing system (IPS) which has two parts: an image analyzing interferometer (IAI) and an image scanning ellipsometer (ISE). The primary purpose of this paper is to present the basic concept of ISE, which is a novel technique to measure the two dimensional thickness profile of a non-uniform, thin film, from several nm up to several μm, in a steady state as well as in a transient state. It is a full-field imaging technique which can study every point on the surface simultaneously with high spatial resolution and thickness sensitivity, i.e., it can measure and map the 2-D film thickness profile. The ISE was tested by measuring the thickness profile and the refractive index of a nonuniform solid film

  8. Ultra-fast quantitative imaging using ptychographic iterative engine based digital micro-mirror device

    Science.gov (United States)

    Sun, Aihui; Tian, Xiaolin; Kong, Yan; Jiang, Zhilong; Liu, Fei; Xue, Liang; Wang, Shouyu; Liu, Cheng

    2018-01-01

    As a lensfree imaging technique, ptychographic iterative engine (PIE) method can provide both quantitative sample amplitude and phase distributions avoiding aberration. However, it requires field of view (FoV) scanning often relying on mechanical translation, which not only slows down measuring speed, but also introduces mechanical errors decreasing both resolution and accuracy in retrieved information. In order to achieve high-accurate quantitative imaging with fast speed, digital micromirror device (DMD) is adopted in PIE for large FoV scanning controlled by on/off state coding by DMD. Measurements were implemented using biological samples as well as USAF resolution target, proving high resolution in quantitative imaging using the proposed system. Considering its fast and accurate imaging capability, it is believed the DMD based PIE technique provides a potential solution for medical observation and measurements.

  9. Compact plane illumination plugin device to enable light sheet fluorescence imaging of multi-cellular organisms on an inverted wide-field microscope

    OpenAIRE

    Guan, Zeyi; Lee, Juhyun; Jiang, Hao; Dong, Siyan; Jen, Nelson; Hsiai, Tzung; Ho, Chih-Ming; Fei, Peng

    2015-01-01

    We developed a compact plane illumination plugin (PIP) device which enabled plane illumination and light sheet fluorescence imaging on a conventional inverted microscope. The PIP device allowed the integration of microscope with tunable laser sheet profile, fast image acquisition, and 3-D scanning. The device is both compact, measuring approximately 15 by 5 by 5 cm, and cost-effective, since we employed consumer electronics and an inexpensive device molding method. We demonstrated that PIP pr...

  10. Devices for Evaluating Imaging Systems. Chapter 15

    Energy Technology Data Exchange (ETDEWEB)

    Demirkaya, O.; Al-Mazrou, R. [Department of Biomedical Physics, King Faisal Specialist Hospital and Research Centre, Riyadh (Saudi Arabia)

    2014-12-15

    A quality management system (QMS) has three main components: (a) Quality assurance (QA); (b) Quality improvement; (c) Quality control (QC). The aim of a QMS is to ensure that the deliverables meet the requirements set forth by the users. The deliverables can be, in general, all the services provided in a nuclear medicine department, and the diagnostic imaging services in particular. In this section, the primary focus is the diagnostic imaging equipment and images produced by them.

  11. Laser line scan underwater imaging by complementary metal-oxide-semiconductor camera

    Science.gov (United States)

    He, Zhiyi; Luo, Meixing; Song, Xiyu; Wang, Dundong; He, Ning

    2017-12-01

    This work employs the complementary metal-oxide-semiconductor (CMOS) camera to acquire images in a scanning manner for laser line scan (LLS) underwater imaging to alleviate backscatter impact of seawater. Two operating features of the CMOS camera, namely the region of interest (ROI) and rolling shutter, can be utilized to perform image scan without the difficulty of translating the receiver above the target as the traditional LLS imaging systems have. By the dynamically reconfigurable ROI of an industrial CMOS camera, we evenly divided the image into five subareas along the pixel rows and then scanned them by changing the ROI region automatically under the synchronous illumination by the fun beams of the lasers. Another scanning method was explored by the rolling shutter operation of the CMOS camera. The fun beam lasers were turned on/off to illuminate the narrow zones on the target in a good correspondence to the exposure lines during the rolling procedure of the camera's electronic shutter. The frame synchronization between the image scan and the laser beam sweep may be achieved by either the strobe lighting output pulse or the external triggering pulse of the industrial camera. Comparison between the scanning and nonscanning images shows that contrast of the underwater image can be improved by our LLS imaging techniques, with higher stability and feasibility than the mechanically controlled scanning method.

  12. Thyroid Scan and Uptake

    Medline Plus

    Full Text Available ... Because nuclear medicine procedures are able to pinpoint molecular activity within the body, they offer the potential ... or imaging device that produces pictures and provides molecular information. The thyroid scan and thyroid uptake provide ...

  13. Clean Up Your Image: A Beginner's Guide to Scanning and Photoshop

    Science.gov (United States)

    Stitzer, Michael S.

    2005-01-01

    In this article, the author addresses the key steps of scanning and illustrates the process with screen shots taken from a Macintosh G4 Powerbook computer running OSX and Adobe Photoshop 7.0. After reviewing scanning procedures, the author describes how to use Photoshop 7.0 to manipulate a scanned image. This activity gives students a good general…

  14. Performance of a malaria microscopy image analysis slide reading device

    Directory of Open Access Journals (Sweden)

    Prescott William R

    2012-05-01

    Full Text Available Abstract Background Viewing Plasmodium in Romanovsky-stained blood has long been considered the gold standard for diagnosis and a cornerstone in management of the disease. This method however, requires a subjective evaluation by trained, experienced diagnosticians and establishing proficiency of diagnosis is fraught with many challenges. Reported here is an evaluation of a diagnostic system (a “device” consisting of a microscope, a scanner, and a computer algorithm that evaluates scanned images of standard Giemsa-stained slides and reports species and parasitaemia. Methods The device was challenged with two independent tests: a 55 slide, expert slide reading test the composition of which has been published by the World Health Organization (“WHO55” test, and a second test in which slides were made from a sample of consenting subjects participating in a malaria incidence survey conducted in Equatorial Guinea (EGMIS test. These subjects’ blood was tested by malaria RDT as well as having the blood smear diagnosis unequivocally determined by a worldwide panel of a minimum of six reference microscopists. Only slides with unequivocal microscopic diagnoses were used for the device challenge, n = 119. Results On the WHO55 test, the device scored a “Level 4” using the WHO published grading scheme. Broken down by more traditional analysis parameters this result was translated to 89% and 70% sensitivity and specificity, respectively. Species were correctly identified in 61% of the slides and the quantification of parasites fell within acceptable range of the validated parasitaemia in 10% of the cases. On the EGMIS test it scored 100% and 94% sensitivity/specificity, with 64% of the species correct and 45% of the parasitaemia within an acceptable range. A pooled analysis of the 174 slides used for both tests resulted in an overall 92% sensitivity and 90% specificity with 61% species and 19% quantifications correct. Conclusions In its

  15. Statistical image reconstruction methods for simultaneous emission/transmission PET scans

    International Nuclear Information System (INIS)

    Erdogan, H.; Fessler, J.A.

    1996-01-01

    Transmission scans are necessary for estimating the attenuation correction factors (ACFs) to yield quantitatively accurate PET emission images. To reduce the total scan time, post-injection transmission scans have been proposed in which one can simultaneously acquire emission and transmission data using rod sources and sinogram windowing. However, since the post-injection transmission scans are corrupted by emission coincidences, accurate correction for attenuation becomes more challenging. Conventional methods (emission subtraction) for ACF computation from post-injection scans are suboptimal and require relatively long scan times. We introduce statistical methods based on penalized-likelihood objectives to compute ACFs and then use them to reconstruct lower noise PET emission images from simultaneous transmission/emission scans. Simulations show the efficacy of the proposed methods. These methods improve image quality and SNR of the estimates as compared to conventional methods

  16. 21 CFR 892.2010 - Medical image storage device.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Medical image storage device. 892.2010 Section 892.2010 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED..., and digital memory. (b) Classification. Class I (general controls). The device is exempt from the...

  17. Printing line/space patterns on nonplanar substrates using a digital micromirror device-based point-array scanning technique

    Science.gov (United States)

    Kuo, Hung-Fei; Kao, Guan-Hsuan; Zhu, Liang-Xiu; Hung, Kuo-Shu; Lin, Yu-Hsin

    2018-02-01

    This study used a digital micromirror device (DMD) to produce point-array patterns and employed a self-developed optical system to define line-and-space patterns on nonplanar substrates. First, field tracing was employed to analyze the aerial images of the lithographic system, which comprised an optical system and the DMD. Multiobjective particle swarm optimization was then applied to determine the spot overlapping rate used. The objective functions were set to minimize linewidth and maximize image log slope, through which the dose of the exposure agent could be effectively controlled and the quality of the nonplanar lithography could be enhanced. Laser beams with 405-nm wavelength were employed as the light source. Silicon substrates coated with photoresist were placed on a nonplanar translation stage. The DMD was used to produce lithographic patterns, during which the parameters were analyzed and optimized. The optimal delay time-sequence combinations were used to scan images of the patterns. Finally, an exposure linewidth of less than 10 μm was successfully achieved using the nonplanar lithographic process.

  18. A versatile LabVIEW and field-programmable gate array-based scanning probe microscope for in operando electronic device characterization.

    Science.gov (United States)

    Berger, Andrew J; Page, Michael R; Jacob, Jan; Young, Justin R; Lewis, Jim; Wenzel, Lothar; Bhallamudi, Vidya P; Johnston-Halperin, Ezekiel; Pelekhov, Denis V; Hammel, P Chris

    2014-12-01

    Understanding the complex properties of electronic and spintronic devices at the micro- and nano-scale is a topic of intense current interest as it becomes increasingly important for scientific progress and technological applications. In operando characterization of such devices by scanning probe techniques is particularly well-suited for the microscopic study of these properties. We have developed a scanning probe microscope (SPM) which is capable of both standard force imaging (atomic, magnetic, electrostatic) and simultaneous electrical transport measurements. We utilize flexible and inexpensive FPGA (field-programmable gate array) hardware and a custom software framework developed in National Instrument's LabVIEW environment to perform the various aspects of microscope operation and device measurement. The FPGA-based approach enables sensitive, real-time cantilever frequency-shift detection. Using this system, we demonstrate electrostatic force microscopy of an electrically biased graphene field-effect transistor device. The combination of SPM and electrical transport also enables imaging of the transport response to a localized perturbation provided by the scanned cantilever tip. Facilitated by the broad presence of LabVIEW in the experimental sciences and the openness of our software solution, our system permits a wide variety of combined scanning and transport measurements by providing standardized interfaces and flexible access to all aspects of a measurement (input and output signals, and processed data). Our system also enables precise control of timing (synchronization of scanning and transport operations) and implementation of sophisticated feedback protocols, and thus should be broadly interesting and useful to practitioners in the field.

  19. An Intelligent Improvement of Internet-Wide Scan Engine for Fast Discovery of Vulnerable IoT Devices

    Directory of Open Access Journals (Sweden)

    Hwankuk Kim

    2018-05-01

    Full Text Available Since 2016, Mirai and Persirai malware have infected hundreds of thousands of Internet of Things (IoT devices and created a massive IoT botnet, which caused distributed denial of service (DDoS attacks. IoT malware targets vulnerable IoT devices, which are vulnerable to security risks. Techniques are needed to prevent IoT devices from being exploited by attackers. However, unlike high-performance PCs, IoT devices are lightweight, low-power, and low-cost, having performance limitations regarding processing and memory, which makes it difficult to install security and anti-malware programs. Recently, several studies have been attempted to quickly search for vulnerable internet-connected devices to solve this real issue. Issues yet to be studied still exist regarding these types of internet-wide scan technologies, such as filtering by security devices and a shortage of collected operating system (OS information. This paper proposes an intelligent internet-wide scan model that improves IP state scanning with advanced internet protocol (IP randomization, reactive protocol (port scanning, and OS fingerprinting scanning, applying k* algorithm in order to find vulnerable IoT devices. Additionally, we describe the experiment’s results compared to the existing internet-wide scan technologies, such as ZMap and Shodan. As a result, the proposed model experimentally shows improved performance. Although we improved the ZMap, the throughput per minute (TPM performance is similar to ZMap without degrading the IP scan throughput and the performance of generating a single IP address is about 118% better than ZMap. In the protocol scan performance experiments, it is about 129% better than the Censys based ZMap, and the performance of OS fingerprinting is better than ZMap, with about 50% accuracy.

  20. New approach towards imaging λ-DNA using scanning tunneling ...

    Indian Academy of Sciences (India)

    Wintec

    spectroscopy (STS) at different stages depict a broad distribution of defect states in the bandgap ... DNA; scanning tunneling microscopy; Langmuir Blodget technique; silanization. 1. ... assembled monolayer (SAM) of C-8 silane gave stable.

  1. Automated vessel shadow segmentation of fovea-centered spectral-domain images from multiple OCT devices

    Science.gov (United States)

    Wu, Jing; Gerendas, Bianca S.; Waldstein, Sebastian M.; Simader, Christian; Schmidt-Erfurth, Ursula

    2014-03-01

    Spectral-domain Optical Coherence Tomography (SD-OCT) is a non-invasive modality for acquiring high reso- lution, three-dimensional (3D) cross sectional volumetric images of the retina and the subretinal layers. SD-OCT also allows the detailed imaging of retinal pathology, aiding clinicians in the diagnosis of sight degrading diseases such as age-related macular degeneration (AMD) and glaucoma.1 Disease diagnosis, assessment, and treatment requires a patient to undergo multiple OCT scans, possibly using different scanning devices, to accurately and precisely gauge disease activity, progression and treatment success. However, the use of OCT imaging devices from different vendors, combined with patient movement may result in poor scan spatial correlation, potentially leading to incorrect patient diagnosis or treatment analysis. Image registration can be used to precisely compare disease states by registering differing 3D scans to one another. In order to align 3D scans from different time- points and vendors using registration, landmarks are required, the most obvious being the retinal vasculature. Presented here is a fully automated cross-vendor method to acquire retina vessel locations for OCT registration from fovea centred 3D SD-OCT scans based on vessel shadows. Noise filtered OCT scans are flattened based on vendor retinal layer segmentation, to extract the retinal pigment epithelium (RPE) layer of the retina. Voxel based layer profile analysis and k-means clustering is used to extract candidate vessel shadow regions from the RPE layer. In conjunction, the extracted RPE layers are combined to generate a projection image featuring all candidate vessel shadows. Image processing methods for vessel segmentation of the OCT constructed projection image are then applied to optimize the accuracy of OCT vessel shadow segmentation through the removal of false positive shadow regions such as those caused by exudates and cysts. Validation of segmented vessel shadows uses

  2. Positron annihilation imaging device using multiple offset rings of detectors

    International Nuclear Information System (INIS)

    Thompson, C.J.

    1981-01-01

    This patent application relates to a positron annihilation imaging device comprising two or more coaxial circular arrays of detectors (2,2'), with the detectors in one array angularly offset with respect to the detectors in the adjacent array to detect more than one tomographic image simultaneously through different cross-sections of a patient. (author)

  3. Scanning capacitance microscopy of atomically-precise donor devices in Si

    Science.gov (United States)

    Bussmann, Ezra; Rudolph, M.; Carr, S. M.; Subramania, G.; Ten Eyck, G.; Dominguez, J.; Lilly, M. P.; Carroll, M. S.; QIST Team

    2014-03-01

    Recently, a scanning tunneling microscopy (STM) technique to fabricate atomically-precise dopant-based nanoelectronics in Si has been developed. Phosphorus donors are placed via an atomic-precision template formed by STM H-depassivation lithography, then capped with epi-Si and lastly metal contacts are made to the buried donor layer using conventional microfabrication. New challenges are introduced with this approach that center around difficulties to locate and characterize the pattern of buried donors. In this talk, we show that scanning capacitance microscopy (SCM) can image these buried donor nanostructures with sub-100-nm tip-limited resolution. The technique is used to successfully locate and characterize buried donor nanostructures relative to surface alignment marks. This approach relaxes alignment requirements for the STM lithography step and can offer improved alignment of subsequent metallization steps. The SCM technique is also used to nondestructively image the shape of the electronic carrier distribution and characterize the relative doping levels. This work, performed in part at the Center for Integrated Nanotechnologies, a U.S. DOE Office of Basic Energy Sciences user facility, was supported by Sandia's Lab Directed Research and Development Program. Sandia is a multi-program lab operated by Sandia Corp, a Lockheed-Martin Company, for U. S. DOE under Contract DE-AC04-94AL85000.

  4. The signature-based radiation-scanning approach to standoff detection of improvised explosive devices

    International Nuclear Information System (INIS)

    Brewer, R.L.; Dunn, W.L.; Heider, S.; Matthew, C.; Yang, X.

    2012-01-01

    The signature-based radiation-scanning technique for detection of improvised explosive devices is described. The technique seeks to detect nitrogen-rich chemical explosives present in a target. The technology compares a set of “signatures” obtained from a test target to a collection of “templates”, sets of signatures for a target that contain an explosive in a specific configuration. Interrogation of nitrogen-rich fertilizer samples, which serve as surrogates for explosives, is shown experimentally to be able to discriminate samples of 3.8 L and larger. - Highlights: ► Signature-based radiation-scanning techniques applied to detection of explosives. ► Nitrogen-rich fertilizer samples served as surrogate explosive samples. ► Signatures of a target compared to collections of templates of surrogate explosives. ► Figure-of-merit determined for neutron and neutron-induced gamma-ray signatures. ► Discrimination of surrogate explosive from inert samples of 3.8 L and larger.

  5. [Digital thoracic radiology: devices, image processing, limits].

    Science.gov (United States)

    Frija, J; de Géry, S; Lallouet, F; Guermazi, A; Zagdanski, A M; De Kerviler, E

    2001-09-01

    In a first part, the different techniques of digital thoracic radiography are described. Since computed radiography with phosphore plates are the most commercialized it is more emphasized. But the other detectors are also described, as the drum coated with selenium and the direct digital radiography with selenium detectors. The other detectors are also studied in particular indirect flat panels detectors and the system with four high resolution CCD cameras. In a second step the most important image processing are discussed: the gradation curves, the unsharp mask processing, the system MUSICA, the dynamic range compression or reduction, the soustraction with dual energy. In the last part the advantages and the drawbacks of computed thoracic radiography are emphasized. The most important are the almost constant good quality of the pictures and the possibilities of image processing.

  6. Intrasubject correlation between static scan and distribution volume images for [11C]flumazenil PET

    International Nuclear Information System (INIS)

    Mishina, Masahiro; Senda, Michio; Kimura, Yuichi

    2000-01-01

    Accumulation of [ 11 C]flumazenil (FMZ) reflects central nervous system benzodiazepine receptor (BZR). We searched for the optimal time for a static PET scan with FMZ as semi-quantitative imaging of BZR distribution. In 10 normal subjects, a dynamic series of decay-corrected PET scans was performed for 60 minutes, and the arterial blood was sampled during the scan to measure radioactivity and labeled metabolites. We generated 13 kinds of ''static scan'' images from the dynamic scan in each subject, and analyzed the pixel correlation for these images versus distribution volume (DV) images. We also analyzed the time for the [ 11 C]FMZ in plasma and tissue to reach the equilibrium. The intra-subject pixel correlation demonstrated that the static scan'' images for the period centering around 30 minutes post-injection had the strongest linear correlation with the DV image. The ratio of radioactivity in the cortex to that in the plasma reached a peak at 40 minutes after injection. Considering the physical decay and patient burden, we conclude that the decay corrected static scan for [ 11 C]FMZ PET as semi-quantitative imaging of BZR distribution is to be optimally acquired from 20 to 40 minutes after injection. (author)

  7. Sequential {sup 123}I-iododexetimide scans in temporal lobe epilepsy: comparison with neuroimaging scans (MR imaging and {sup 18}F-FDG PET imaging)

    Energy Technology Data Exchange (ETDEWEB)

    Mohamed, Armin [Royal Prince Alfred Hospital, Department of PET and Nuclear Medicine, Camperdown, NSW (Australia); Royal Prince Alfred Hospital, Comprehensive Epilepsy Service, Camperdown, NSW (Australia); University of Sydney, Faculty of Medicine, Sydney, NSW (Australia); Eberl, Stefan; Henderson, David; Beveridge, Scott; Constable, Chris [Royal Prince Alfred Hospital, Department of PET and Nuclear Medicine, Camperdown, NSW (Australia); Fulham, Michael J. [Royal Prince Alfred Hospital, Department of PET and Nuclear Medicine, Camperdown, NSW (Australia); Kassiou, Michael [Royal Prince Alfred Hospital, Department of PET and Nuclear Medicine, Camperdown, NSW (Australia); University of Sydney, Department of Pharmacology, Sydney, NSW (Australia); Zaman, Aysha [University of Sydney, Faculty of Medicine, Sydney, NSW (Australia); Lo, Sing Kai [University of Sydney, Institute of International Health, Sydney, NSW (Australia)

    2005-02-01

    Muscarinic acetylcholine receptors (mAChRs) play an important role in the generation of seizures. Single-photon emission computed tomography (SPECT) with {sup 123}I-iododexetimide (IDEX) depicts tracer uptake by mAChRs. Our aims were to: (a) determine the optimum time for interictal IDEX SPECT imaging; (b) determine the accuracy of IDEX scans in the localisation of seizure foci when compared with video EEG and MR imaging in patients with temporal lobe epilepsy (TLE); (c) characterise the distribution of IDEX binding in the temporal lobes and (d) compare IDEX SPECT and {sup 18}F-fluorodeoxyglucose (FDG) positron emission tomography (PET) in identifying seizure foci. We performed sequential scans using IDEX SPECT imaging at 0, 3, 6 and 24 h in 12 consecutive patients with refractory TLE undergoing assessment for epilepsy surgery. Visual and region of interest analyses of the mesial, lateral and polar regions of the temporal lobes were used to compare IDEX SPECT, FDG PET and MR imaging in seizure onset localisation. The 6-h IDEX scan (92%; {kappa}=0.83, p=0.003) was superior to the 0-h (36%; {kappa}=0.01, p>0.05), 3-h (55%; {kappa}=0.13, p>0.05) and 24-h IDEX scans in identifying the temporal lobe of seizure origin. The 6-h IDEX scan correctly predicted the temporal lobe of seizure origin in two patients who required intracranial EEG recordings to define the seizure onset. Reduced ligand binding was most marked at the temporal pole and mesial temporal structures. IDEX SPECT was superior to interictal FDG PET (75%; {kappa}=0.66, p=0.023) in seizure onset localisation. MR imaging was non-localising in two patients in whom it was normal and in another patient in whom there was bilateral symmetrical hippocampal atrophy. The 6-h IDEX SPECT scan is a viable alternative to FDG PET imaging in seizure onset localisation in TLE. (orig.)

  8. Sequential 123I-iododexetimide scans in temporal lobe epilepsy: comparison with neuroimaging scans (MR imaging and 18F-FDG PET imaging)

    International Nuclear Information System (INIS)

    Mohamed, Armin; Eberl, Stefan; Henderson, David; Beveridge, Scott; Constable, Chris; Fulham, Michael J.; Kassiou, Michael; Zaman, Aysha; Lo, Sing Kai

    2005-01-01

    Muscarinic acetylcholine receptors (mAChRs) play an important role in the generation of seizures. Single-photon emission computed tomography (SPECT) with 123 I-iododexetimide (IDEX) depicts tracer uptake by mAChRs. Our aims were to: (a) determine the optimum time for interictal IDEX SPECT imaging; (b) determine the accuracy of IDEX scans in the localisation of seizure foci when compared with video EEG and MR imaging in patients with temporal lobe epilepsy (TLE); (c) characterise the distribution of IDEX binding in the temporal lobes and (d) compare IDEX SPECT and 18 F-fluorodeoxyglucose (FDG) positron emission tomography (PET) in identifying seizure foci. We performed sequential scans using IDEX SPECT imaging at 0, 3, 6 and 24 h in 12 consecutive patients with refractory TLE undergoing assessment for epilepsy surgery. Visual and region of interest analyses of the mesial, lateral and polar regions of the temporal lobes were used to compare IDEX SPECT, FDG PET and MR imaging in seizure onset localisation. The 6-h IDEX scan (92%; κ=0.83, p=0.003) was superior to the 0-h (36%; κ=0.01, p>0.05), 3-h (55%; κ=0.13, p>0.05) and 24-h IDEX scans in identifying the temporal lobe of seizure origin. The 6-h IDEX scan correctly predicted the temporal lobe of seizure origin in two patients who required intracranial EEG recordings to define the seizure onset. Reduced ligand binding was most marked at the temporal pole and mesial temporal structures. IDEX SPECT was superior to interictal FDG PET (75%; κ=0.66, p=0.023) in seizure onset localisation. MR imaging was non-localising in two patients in whom it was normal and in another patient in whom there was bilateral symmetrical hippocampal atrophy. The 6-h IDEX SPECT scan is a viable alternative to FDG PET imaging in seizure onset localisation in TLE. (orig.)

  9. Fast Fiber-Coupled Imaging Devices

    Energy Technology Data Exchange (ETDEWEB)

    Brockington, Samuel; Case, Andrew; Witherspoon, Franklin

    2018-04-22

    HyperV Technologies Corp. has successfully designed, built and experimentally demonstrated a full scale 1024 pixel 100 MegaFrames/s fiber coupled camera with 12 or 14 bits, and record lengths of 32K frames, exceeding our original performance objectives. This high-pixel-count, fiber optically-coupled, imaging diagnostic can be used for investigating fast, bright plasma events. In Phase 1 of this effort, a 100 pixel fiber-coupled fast streak camera for imaging plasma jet profiles was constructed and successfully demonstrated. The resulting response from outside plasma physics researchers emphasized development of increased pixel performance as a higher priority over increasing pixel count. In this Phase 2 effort, HyperV therefore focused on increasing the sample rate and bit-depth of the photodiode pixel designed in Phase 1, while still maintaining a long record length and holding the cost per channel to levels which allowed up to 1024 pixels to be constructed. Cost per channel was $53.31, very close to our original target of $50 per channel. The system consists of an imaging "camera head" coupled to a photodiode bank with an array of optical fibers. The output of these fast photodiodes is then digitized at 100 Megaframes per second and stored in record lengths of 32,768 samples with bit depths of 12 to 14 bits per pixel. Longer record lengths are possible with additional memory. A prototype imaging system with up to 1024 pixels was designed and constructed and used to successfully take movies of very fast moving plasma jets as a demonstration of the camera performance capabilities. Some faulty electrical components on the 64 circuit boards resulted in only 1008 functional channels out of 1024 on this first generation prototype system. We experimentally observed backlit high speed fan blades in initial camera testing and then followed that with full movies and streak images of free flowing high speed plasma jets (at 30-50 km/s). Jet structure and jet collisions onto

  10. Parallel Processing of Images in Mobile Devices using BOINC

    Science.gov (United States)

    Curiel, Mariela; Calle, David F.; Santamaría, Alfredo S.; Suarez, David F.; Flórez, Leonardo

    2018-04-01

    Medical image processing helps health professionals make decisions for the diagnosis and treatment of patients. Since some algorithms for processing images require substantial amounts of resources, one could take advantage of distributed or parallel computing. A mobile grid can be an adequate computing infrastructure for this problem. A mobile grid is a grid that includes mobile devices as resource providers. In a previous step of this research, we selected BOINC as the infrastructure to build our mobile grid. However, parallel processing of images in mobile devices poses at least two important challenges: the execution of standard libraries for processing images and obtaining adequate performance when compared to desktop computers grids. By the time we started our research, the use of BOINC in mobile devices also involved two issues: a) the execution of programs in mobile devices required to modify the code to insert calls to the BOINC API, and b) the division of the image among the mobile devices as well as its merging required additional code in some BOINC components. This article presents answers to these four challenges.

  11. Parallel Processing of Images in Mobile Devices using BOINC

    Directory of Open Access Journals (Sweden)

    Curiel Mariela

    2018-04-01

    Full Text Available Medical image processing helps health professionals make decisions for the diagnosis and treatment of patients. Since some algorithms for processing images require substantial amounts of resources, one could take advantage of distributed or parallel computing. A mobile grid can be an adequate computing infrastructure for this problem. A mobile grid is a grid that includes mobile devices as resource providers. In a previous step of this research, we selected BOINC as the infrastructure to build our mobile grid. However, parallel processing of images in mobile devices poses at least two important challenges: the execution of standard libraries for processing images and obtaining adequate performance when compared to desktop computers grids. By the time we started our research, the use of BOINC in mobile devices also involved two issues: a the execution of programs in mobile devices required to modify the code to insert calls to the BOINC API, and b the division of the image among the mobile devices as well as its merging required additional code in some BOINC components. This article presents answers to these four challenges.

  12. Scanning Emitter Lifetime Imaging Microscopy for Spontaneous Emission Control

    DEFF Research Database (Denmark)

    Frimmer, Martin; Chen, Yuntian; Koenderink, A. Femius

    2011-01-01

    We report an experimental technique to map and exploit the local density of optical states of arbitrary planar nanophotonic structures. The method relies on positioning a spontaneous emitter attached to a scanning probe deterministically and reversibly with respect to its photonic environment while...

  13. Metastatic calcification of the stomach imaged on a bone scan

    Energy Technology Data Exchange (ETDEWEB)

    Goldstein, R.; Ryo, U.Y.; Pinsky, S.M.

    1984-10-01

    A whole body bone scan obtained on a 21-year-old woman with sickle cell disease and chronic renal failure showed localization of the radionuclide diffusely in the stomach. The localization of the radionuclide represented metastatic calcification of the stomach caused by secondary hyperparathyroidism.

  14. Mathematical models for correction of images, obtained at radioisotope scan

    International Nuclear Information System (INIS)

    Glaz, A.; Lubans, A.

    2002-01-01

    The images, which obtained at radioisotope scintigraphy, contain distortions. Distortions appear as a result of absorption of radiation by patient's body's tissues. Two mathematical models for reducing of such distortions are proposed. Image obtained by only one gamma camera is used in the first mathematical model. Unfortunately, this model allows processing of the images only in case, when it can be assumed, that the investigated organ has a symmetric form. The images obtained by two gamma cameras are used in the second model. It gives possibility to assume that the investigated organ has non-symmetric form and to acquire more precise results. (authors)

  15. Device for imaging an object by means of masks of spatially modulable electromagnetic radiation or corpuscular radiation of high energy

    International Nuclear Information System (INIS)

    Barrett, H.H.

    1979-01-01

    The radiogram of the thyroid is produced by means of a detector device operating similar to a scintillation camera. Between thyroid and detector device there is placed a mask having modulating areas, permeable and impermeable to radiation succeeding each other with decreasing extension. The scanning signal has got the shape of a radar signal with chirp modulation. The filtering unit used for it is a pulse compression filter. The image of the radiation energy distribution on the recording surface of the detector device is thus decoded and compressed to a number of image points giving the picture of the thyroid. (RW) [de

  16. Benefits and unexpected artifacts of biplanar digital slot-scanning imaging in children

    Energy Technology Data Exchange (ETDEWEB)

    Blumer, Steven L. [Nemours/A.I duPont Hospital for Children, Department of Medical Imaging, Wilmington, DE (United States); Dinan, David [Nemours Children' s Hospital, Orlando, FL (United States); Grissom, Leslie E. [Nemours/Alfred I. duPont Hospital for Children, Department of Radiology, Wilmington, DE (United States)

    2014-07-15

    Biplanar digital slot-scanning allows for relatively low-dose orthopedic imaging, an advantage in imaging children given the growing concerns regarding radiosensitivity. We have used this system for approximately 1 year for orthopedic imaging of the spine and lower extremities. We have noted advantages of using the digital slot-scanning system when compared with computed radiographic and standard digital radiographic imaging systems, but we also found unexpected but common imaging artifacts that are the direct result of the imaging method and that have not been reported. This pictorial essay serves to familiarize radiologists with the advantages of the digital slot-scanning system as well as imaging artifacts common with this new technology. (orig.)

  17. Real-time scanning charged-particle microscope image composition with correction of drift.

    Science.gov (United States)

    Cizmar, Petr; Vladár, András E; Postek, Michael T

    2011-04-01

    In this article, a new scanning electron microscopy (SEM) image composition technique is described, which can significantly reduce drift related image corruptions. Drift distortion commonly causes blur and distortions in the SEM images. Such corruption ordinarily appears when conventional image-acquisition methods, i.e., "slow scan" and "fast scan," are applied. The damage is often very significant; it may render images unusable for metrology applications, especially where subnanometer accuracy is required. The described correction technique works with a large number of quickly taken frames, which are properly aligned and then composed into a single image. Such image contains much less noise than the individual frames, while the blur and deformation is minimized. This technique also provides useful information about changes of the sample position in time, which may be applied to investigate the drift properties of the instrument without a need of additional equipment.

  18. Infrared scanning laser ophthalmoscope imaging of the macula and its correlation with functional loss and structural changes in patients with stargardt disease.

    Science.gov (United States)

    Anastasakis, Anastasios; Fishman, Gerald A; Lindeman, Martin; Genead, Mohamed A; Zhou, Wensheng

    2011-05-01

    To correlate the degree of functional loss with structural changes in patients with Stargardt disease. Eighteen eyes of 10 patients with Stargardt disease were studied. Scanning laser ophthalmoscope infrared images were compared with corresponding spectral-domain optical coherence tomography scans. Additionally, scanning laser ophthalmoscope microperimetry was performed, and results were superimposed on scanning laser ophthalmoscope infrared images and in selected cases on fundus autofluorescence images. Seventeen of 18 eyes showed a distinct hyporeflective foveal and/or perifoveal area with distinct borders on scanning laser ophthalmoscope infrared images, which was less evident on funduscopy and incompletely depicted in fundus autofluorescence images. This hyporeflective zone corresponded to areas of significantly elevated psychophysical thresholds on microperimetry testing, in addition to thinning of the retinal pigment epithelium and disorganization or loss of the photoreceptor cell inner segment-outer segment junction and external-limiting membrane on spectral-domain optical coherence tomography. Scanning laser ophthalmoscope infrared fundus images are useful for depicting retinal structural changes in patients with Stargardt disease. A spectral-domain optical coherence tomography/scanning laser ophthalmoscope microperimetry device allows for a direct correlation of structural abnormalities with functional defects that will likely be applicable for the determination of retinal areas for potential improvement of retinal function in these patients during future clinical trials and for the monitoring of the diseases' natural history.

  19. Informatics in radiology: Efficiency metrics for imaging device productivity.

    Science.gov (United States)

    Hu, Mengqi; Pavlicek, William; Liu, Patrick T; Zhang, Muhong; Langer, Steve G; Wang, Shanshan; Place, Vicki; Miranda, Rafael; Wu, Teresa Tong

    2011-01-01

    Acute awareness of the costs associated with medical imaging equipment is an ever-present aspect of the current healthcare debate. However, the monitoring of productivity associated with expensive imaging devices is likely to be labor intensive, relies on summary statistics, and lacks accepted and standardized benchmarks of efficiency. In the context of the general Six Sigma DMAIC (design, measure, analyze, improve, and control) process, a World Wide Web-based productivity tool called the Imaging Exam Time Monitor was developed to accurately and remotely monitor imaging efficiency with use of Digital Imaging and Communications in Medicine (DICOM) combined with a picture archiving and communication system. Five device efficiency metrics-examination duration, table utilization, interpatient time, appointment interval time, and interseries time-were derived from DICOM values. These metrics allow the standardized measurement of productivity, to facilitate the comparative evaluation of imaging equipment use and ongoing efforts to improve efficiency. A relational database was constructed to store patient imaging data, along with device- and examination-related data. The database provides full access to ad hoc queries and can automatically generate detailed reports for administrative and business use, thereby allowing staff to monitor data for trends and to better identify possible changes that could lead to improved productivity and reduced costs in association with imaging services. © RSNA, 2011.

  20. Compact imaging Bragg spectrometer for fusion devices

    International Nuclear Information System (INIS)

    Bertschinger, G.; Biel, W.; Jaegers, H.; Marchuk, O.

    2004-01-01

    A compact imaging x-ray spectrometer has been designed for tokamaks and stellarators to measure the plasma parameters at different spatial chords. It has been optimized for high spectral resolution and high sensitivity. High spectral resolution is obtained by using solid state detectors and minimizing the imaging errors of the spherical crystals. It is shown, that using spherical crystals the solid angle and hence the throughput can be increased significantly, without compromising the spectral resolution. The design is useful for the measurement of the spectra of He- and H-like ions from Si to Kr. The spectral resolution is sufficient for the measurement of plasma parameters. The temporal resolution is high enough for transport studies by gas puff and laser ablation experiments. The design is based on a modified Johann spectrometer mount, utilizing a spherically bent crystal instead of the cylindrically bent crystal in the traditional Johann mount. The astigmatism of the wavelength selective reflection on the spherical crystal is applied to obtain imaging of an extended plasma source on a two-dimensional detector. For each element, a separate crystal is required, only in few cases, a crystal can be used for the spectra of two elements. For the spectra of most of the He-like ions from Si up to Kr, suitable crystal cuts have been found on quartz, silicon and germanium crystals with Bragg angles in a small interval around the design value of 53.5 deg. All of the crystals have the same radius. They are fixed on a rotational table. The distance to the detector is adjusted by an x-y table to fit to the Rowland circle

  1. Assessment of hybrid rotation-translation scan schemes for in vivo animal SPECT imaging

    International Nuclear Information System (INIS)

    Xia Yan; Liu Yaqiang; Wang Shi; Ma Tianyu; Yao Rutao; Deng Xiao

    2013-01-01

    To perform in vivo animal single photon emission computed tomography imaging on a stationary detector gantry, we introduced a hybrid rotation-translation (HRT) tomographic scan, a combination of translational and limited angle rotational movements of the image object, to minimize gravity-induced animal motion. To quantitatively assess the performance of ten HRT scan schemes and the conventional rotation-only scan scheme, two simulated phantoms were first scanned with each scheme to derive the corresponding image resolution (IR) in the image field of view. The IR results of all the scan schemes were visually assessed and compared with corresponding outputs of four scan scheme evaluation indices, i.e. sampling completeness (SC), sensitivity (S), conventional system resolution (SR), and a newly devised directional spatial resolution (DR) that measures the resolution in any specified orientation. A representative HRT scheme was tested with an experimental phantom study. Eight of the ten HRT scan schemes evaluated achieved a superior performance compared to two other HRT schemes and the rotation-only scheme in terms of phantom image resolution. The same eight HRT scan schemes also achieved equivalent or better performance in terms of the four quantitative indices than the conventional rotation-only scheme. As compared to the conventional index SR, the new index DR appears to be a more relevant indicator of system resolution performance. The experimental phantom image obtained from the selected HRT scheme was satisfactory. We conclude that it is feasible to perform in vivo animal imaging with a HRT scan scheme and SC and DR are useful predictors for quantitatively assessing the performance of a scan scheme. (paper)

  2. The Image Transceiver Device: Studies of Improved Physical Design.

    Science.gov (United States)

    David, Yitzhak; Efron, Uzi

    2008-07-25

    The Image Transceiver Device (ITD) design is based on combining LCOS micro-display, image processing tools and back illuminated APS imager in single CMOS chip [1]. The device is under development for Head-Mounted Display applications in augmented and virtual reality systems. The main issues with the present design are a high crosstalk of the backside imager and the need to shield the pixel circuitry from the photocharges generated in the silicon substrate. In this publication we present a modified, "deep p-well" ITD pixel design, which provides a significantly reduced crosstalk level, as well as an effective shielding of photo-charges for the pixel circuitry. The simulation performed using Silvaco software [ATLAS Silicon Device Simulator, Ray Trace and Light Absorption programs, Silvaco International, 1998] shows that the new approach provides high photo response and allows increasing the optimal thickness of the die over and above the 10-15 micrometers commonly used for back illuminated imaging devices, thereby improving its mechanical ruggedness following the thinning process and also providing a more efficient absorption of the long wavelength photons. The proposed deep p-well pixel structure is also a technology solution for the fabrication of high performance back illuminated CMOS image sensors.

  3. The Image Transceiver Device: Studies of Improved Physical Design

    Directory of Open Access Journals (Sweden)

    Uzi Efron

    2008-07-01

    Full Text Available The Image Transceiver Device (ITD design is based on combining LCOS micro-display, image processing tools and back illuminated APS imager in single CMOS chip [1]. The device is under development for Head-Mounted Display applications in augmented and virtual reality systems. The main issues with the present design are a high crosstalk of the backside imager and the need to shield the pixel circuitry from the photocharges generated in the silicon substrate. In this publication we present a modified, “deep p-well” ITD pixel design, which provides a significantly reduced crosstalk level, as well as an effective shielding of photo-charges for the pixel circuitry. The simulation performed using Silvaco software [ATLAS Silicon Device Simulator, Ray Trace and Light Absorption programs, Silvaco International, 1998] shows that the new approach provides high photo response and allows increasing the optimal thickness of the die over and above the 10-15 micrometers commonly used for back illuminated imaging devices, thereby improving its mechanical ruggedness following the thinning process and also providing a more efficient absorption of the long wavelength photons. The proposed deep p-well pixel structure is also a technology solution for the fabrication of high performance back illuminated CMOS image sensors.

  4. Tip-Dependent Scanning Tunneling Microscopy Imaging of Ultrathin FeO Films on Pt(111)

    DEFF Research Database (Denmark)

    Merte, Lindsay Richard; Grabow, Lars C.; Peng, Guowen

    2011-01-01

    High-resolution scanning tunneling microscope (STM) images of moiré-structured FeO films on Pt(111) were obtained in a number of different tip-dependent imaging modes. For the first time, the STM images are distinguished and interpreted unambiguously with the help of distinct oxygen...

  5. Three-dimensional imaging and scanning: Current and future applications for pathology

    Directory of Open Access Journals (Sweden)

    Navid Farahani

    2017-01-01

    Full Text Available Imaging is vital for the assessment of physiologic and phenotypic details. In the past, biomedical imaging was heavily reliant on analog, low-throughput methods, which would produce two-dimensional images. However, newer, digital, and high-throughput three-dimensional (3D imaging methods, which rely on computer vision and computer graphics, are transforming the way biomedical professionals practice. 3D imaging has been useful in diagnostic, prognostic, and therapeutic decision-making for the medical and biomedical professions. Herein, we summarize current imaging methods that enable optimal 3D histopathologic reconstruction: Scanning, 3D scanning, and whole slide imaging. Briefly mentioned are emerging platforms, which combine robotics, sectioning, and imaging in their pursuit to digitize and automate the entire microscopy workflow. Finally, both current and emerging 3D imaging methods are discussed in relation to current and future applications within the context of pathology.

  6. Hyperparathyroidism: comparison of MR imaging with radionuclide scanning

    International Nuclear Information System (INIS)

    Peck, W.W.; Higgins, C.B.; Fisher, M.R.; Ling, M.; Okerlund, M.D.; Clark, O.H.

    1987-01-01

    Twenty-three patients with hyperparathyroidism were evaluated preoperatively with magnetic resonance (MR) imaging. Twenty patients also underwent thallium-201/technetium-99m scintigraphy. Of 22 patients with primary hyperparathyroidism, 12 had persistent or recurrent disease. One had secondary hyperparathyroidism due to end-stage renal disease. MR imaging allowed accurate localization of abnormal parathyroid glands in 64% evaluated prospectively and 82% evaluated retrospectively. Scintigraphy allowed localization of 60% evaluated prospectively and 70% retrospectively. The two imaging modalities together allowed detection of 68% evaluated prospectively and 91% retrospectively. MR imaging allowed detection of two of five mediastinal adenomas evaluated prospectively and four of five retrospectively. In patients who underwent both imaging studies, MR was more successful in those with previous neck surgery (73% evaluated prospectively and 91% retrospectively) than in those with no prior surgery (57% prospectively and 71% retrospectively). Scintigraphy allowed accurate localization in 64% evaluated prospectively and 64% retrospectively in patients with previous surgery versus 57% prospectively and 86% retrospectively in patients with no prior neck surgery. Four false-positive results were obtained with MR imaging and three with scintigraphy. MR imaging was useful for parathyroid localization in patients with hyperparathyroidism, particularly in patients requiring additional surgery

  7. CLOSE RANGE HYPERSPECTRAL IMAGING INTEGRATED WITH TERRESTRIAL LIDAR SCANNING APPLIED TO ROCK CHARACTERISATION AT CENTIMETRE SCALE

    Directory of Open Access Journals (Sweden)

    T. H. Kurz

    2012-07-01

    Full Text Available Compact and lightweight hyperspectral imagers allow the application of close range hyperspectral imaging with a ground based scanning setup for geological fieldwork. Using such a scanning setup, steep cliff sections and quarry walls can be scanned with a more appropriate viewing direction and a higher image resolution than from airborne and spaceborne platforms. Integration of the hyperspectral imagery with terrestrial lidar scanning provides the hyperspectral information in a georeferenced framework and enables measurement at centimetre scale. In this paper, three geological case studies are used to demonstrate the potential of this method for rock characterisation. Two case studies are applied to carbonate quarries where mapping of different limestone and dolomite types was required, as well as measurements of faults and layer thicknesses from inaccessible parts of the quarries. The third case study demonstrates the method using artificial lighting, applied in a subsurface scanning scenario where solar radiation cannot be utilised.

  8. Dual-detection confocal fluorescence microscopy: fluorescence axial imaging without axial scanning.

    Science.gov (United States)

    Lee, Dong-Ryoung; Kim, Young-Duk; Gweon, Dae-Gab; Yoo, Hongki

    2013-07-29

    We propose a new method for high-speed, three-dimensional (3-D) fluorescence imaging, which we refer to as dual-detection confocal fluorescence microscopy (DDCFM). In contrast to conventional beam-scanning confocal fluorescence microscopy, where the focal spot must be scanned either optically or mechanically over a sample volume to reconstruct a 3-D image, DDCFM can obtain the depth of a fluorescent emitter without depth scanning. DDCFM comprises two photodetectors, each with a pinhole of different size, in the confocal detection system. Axial information on fluorescent emitters can be measured by the axial response curve through the ratio of intensity signals. DDCFM can rapidly acquire a 3-D fluorescent image from a single two-dimensional scan with less phototoxicity and photobleaching than confocal fluorescence microscopy because no mechanical depth scans are needed. We demonstrated the feasibility of the proposed method by phantom studies.

  9. Image grating metrology using phase-stepping interferometry in scanning beam interference lithography

    Science.gov (United States)

    Li, Minkang; Zhou, Changhe; Wei, Chunlong; Jia, Wei; Lu, Yancong; Xiang, Changcheng; Xiang, XianSong

    2016-10-01

    Large-sized gratings are essential optical elements in laser fusion and space astronomy facilities. Scanning beam interference lithography is an effective method to fabricate large-sized gratings. To minimize the nonlinear phase written into the photo-resist, the image grating must be measured to adjust the left and right beams to interfere at their waists. In this paper, we propose a new method to conduct wavefront metrology based on phase-stepping interferometry. Firstly, a transmission grating is used to combine the two beams to form an interferogram which is recorded by a charge coupled device(CCD). Phase steps are introduced by moving the grating with a linear stage monitored by a laser interferometer. A series of interferograms are recorded as the displacement is measured by the laser interferometer. Secondly, to eliminate the tilt and piston error during the phase stepping, the iterative least square phase shift method is implemented to obtain the wrapped phase. Thirdly, we use the discrete cosine transform least square method to unwrap the phase map. Experiment results indicate that the measured wavefront has a nonlinear phase around 0.05 λ@404.7nm. Finally, as the image grating is acquired, we simulate the print-error written into the photo-resist.

  10. Scanning tomographic particle image velocimetry applied to a turbulent jet

    KAUST Repository

    Casey, T. A.; Sakakibara, J.; Thoroddsen, Sigurdur T

    2013-01-01

    planes in the depth direction by maintaining optimal particle image density and limiting the number of ghost particles. The total measurement volumes contain between 1 ×106 and 3 ×106 velocity vectors calculated from up to 1500 reconstructed depthwise

  11. Imaging by Electrochemical Scanning Tunneling Microscopy and Deconvolution Resolving More Details of Surfaces Nanomorphology

    DEFF Research Database (Denmark)

    Andersen, Jens Enevold Thaulov

    observed in high-resolution images of metallic nanocrystallites may be effectively deconvoluted, as to resolve more details of the crystalline morphology (see figure). Images of surface-crystalline metals indicate that more than a single atomic layer is involved in mediating the tunneling current......Upon imaging, electrochemical scanning tunneling microscopy (ESTM), scanning electrochemical micro-scopy (SECM) and in situ STM resolve information on electronic structures and on surface topography. At very high resolution, imaging processing is required, as to obtain information that relates...... to crystallographic-surface structures. Within the wide range of new technologies, those images surface features, the electrochemical scanning tunneling microscope (ESTM) provides means of atomic resolution where the tip participates actively in the process of imaging. Two metallic surfaces influence ions trapped...

  12. Perceptually Aware Image Retargeting for Mobile Devices.

    Science.gov (United States)

    Zhou, Yinzuo; Zhang, Luming; Zhang, Chao; Li, Ping; Li, Xuelong

    2018-05-01

    Retargeting aims at adapting an original high-resolution photograph/video to a low-resolution screen with an arbitrary aspect ratio. Conventional approaches are generally based on desktop PCs, since the computation might be intolerable for mobile platforms (especially when retargeting videos). Typically, only low-level visual features are exploited, and human visual perception is not well encoded. In this paper, we propose a novel retargeting framework that rapidly shrinks a photograph/video by leveraging human gaze behavior. Specifically, we first derive a geometry-preserving graph ranking algorithm, which efficiently selects a few salient object patches to mimic the human gaze shifting path (GSP) when viewing a scene. Afterward, an aggregation-based CNN is developed to hierarchically learn the deep representation for each GSP. Based on this, a probabilistic model is developed to learn the priors of the training photographs that are marked as aesthetically pleasing by professional photographers. We utilize the learned priors to efficiently shrink the corresponding GSP of a retargeted photograph/video to maximize its similarity to those from the training photographs. Extensive experiments have demonstrated that: 1) our method requires less than 35 ms to retarget a photograph (or a video frame) on popular iOS/Android devices, which is orders of magnitude faster than the conventional retargeting algorithms; 2) the retargeted photographs/videos produced by our method significantly outperform those of its competitors based on a paired-comparison-based user study; and 3) the learned GSPs are highly indicative of human visual attention according to the human eye tracking experiments.

  13. Parallel-scanning tomosynthesis using a slot scanning technique: Fixed-focus reconstruction and the resulting image quality

    International Nuclear Information System (INIS)

    Shibata, Koichi; Notohara, Daisuke; Sakai, Takihito

    2014-01-01

    Purpose: Parallel-scanning tomosynthesis (PS-TS) is a novel technique that fuses the slot scanning technique and the conventional tomosynthesis (TS) technique. This approach allows one to obtain long-view tomosynthesis images in addition to normally sized tomosynthesis images, even when using a system that has no linear tomographic scanning function. The reconstruction technique and an evaluation of the resulting image quality for PS-TS are described in this paper. Methods: The PS-TS image-reconstruction technique consists of several steps (1) the projection images are divided into strips, (2) the strips are stitched together to construct images corresponding to the reconstruction plane, (3) the stitched images are filtered, and (4) the filtered stitched images are back-projected. In the case of PS-TS using the fixed-focus reconstruction method (PS-TS-F), one set of stitched images is used for the reconstruction planes at all heights, thus avoiding the necessity of repeating steps (1)–(3). A physical evaluation of the image quality of PS-TS-F compared with that of the conventional linear TS was performed using a R/F table (Sonialvision safire, Shimadzu Corp., Kyoto, Japan). The tomographic plane with the best theoretical spatial resolution (the in-focus plane, IFP) was set at a height of 100 mm from the table top by adjusting the reconstruction program. First, the spatial frequency response was evaluated at heights of −100, −50, 0, 50, 100, and 150 mm from the IFP using the edge of a 0.3-mm-thick copper plate. Second, the spatial resolution at each height was visually evaluated using an x-ray test pattern (Model No. 38, PTW Freiburg, Germany). Third, the slice sensitivity at each height was evaluated via the wire method using a 0.1-mm-diameter tungsten wire. Phantom studies using a knee phantom and a whole-body phantom were also performed. Results: The spatial frequency response of PS-TS-F yielded the best results at the IFP and degraded slightly as the

  14. Parallel-scanning tomosynthesis using a slot scanning technique: fixed-focus reconstruction and the resulting image quality.

    Science.gov (United States)

    Shibata, Koichi; Notohara, Daisuke; Sakai, Takihito

    2014-11-01

    Parallel-scanning tomosynthesis (PS-TS) is a novel technique that fuses the slot scanning technique and the conventional tomosynthesis (TS) technique. This approach allows one to obtain long-view tomosynthesis images in addition to normally sized tomosynthesis images, even when using a system that has no linear tomographic scanning function. The reconstruction technique and an evaluation of the resulting image quality for PS-TS are described in this paper. The PS-TS image-reconstruction technique consists of several steps (1) the projection images are divided into strips, (2) the strips are stitched together to construct images corresponding to the reconstruction plane, (3) the stitched images are filtered, and (4) the filtered stitched images are back-projected. In the case of PS-TS using the fixed-focus reconstruction method (PS-TS-F), one set of stitched images is used for the reconstruction planes at all heights, thus avoiding the necessity of repeating steps (1)-(3). A physical evaluation of the image quality of PS-TS-F compared with that of the conventional linear TS was performed using a R/F table (Sonialvision safire, Shimadzu Corp., Kyoto, Japan). The tomographic plane with the best theoretical spatial resolution (the in-focus plane, IFP) was set at a height of 100 mm from the table top by adjusting the reconstruction program. First, the spatial frequency response was evaluated at heights of -100, -50, 0, 50, 100, and 150 mm from the IFP using the edge of a 0.3-mm-thick copper plate. Second, the spatial resolution at each height was visually evaluated using an x-ray test pattern (Model No. 38, PTW Freiburg, Germany). Third, the slice sensitivity at each height was evaluated via the wire method using a 0.1-mm-diameter tungsten wire. Phantom studies using a knee phantom and a whole-body phantom were also performed. The spatial frequency response of PS-TS-F yielded the best results at the IFP and degraded slightly as the distance from the IFP increased. A

  15. Parallel-scanning tomosynthesis using a slot scanning technique: Fixed-focus reconstruction and the resulting image quality

    Energy Technology Data Exchange (ETDEWEB)

    Shibata, Koichi, E-mail: shibatak@suzuka-u.ac.jp [Department of Radiological Technology, Faculty of Health Science, Suzuka University of Medical Science 1001-1, Kishioka-cho, Suzuka 510-0293 (Japan); Notohara, Daisuke; Sakai, Takihito [R and D Department, Medical Systems Division, Shimadzu Corporation 1, Nishinokyo-Kuwabara-cho, Nakagyo-ku, Kyoto 604-8511 (Japan)

    2014-11-01

    Purpose: Parallel-scanning tomosynthesis (PS-TS) is a novel technique that fuses the slot scanning technique and the conventional tomosynthesis (TS) technique. This approach allows one to obtain long-view tomosynthesis images in addition to normally sized tomosynthesis images, even when using a system that has no linear tomographic scanning function. The reconstruction technique and an evaluation of the resulting image quality for PS-TS are described in this paper. Methods: The PS-TS image-reconstruction technique consists of several steps (1) the projection images are divided into strips, (2) the strips are stitched together to construct images corresponding to the reconstruction plane, (3) the stitched images are filtered, and (4) the filtered stitched images are back-projected. In the case of PS-TS using the fixed-focus reconstruction method (PS-TS-F), one set of stitched images is used for the reconstruction planes at all heights, thus avoiding the necessity of repeating steps (1)–(3). A physical evaluation of the image quality of PS-TS-F compared with that of the conventional linear TS was performed using a R/F table (Sonialvision safire, Shimadzu Corp., Kyoto, Japan). The tomographic plane with the best theoretical spatial resolution (the in-focus plane, IFP) was set at a height of 100 mm from the table top by adjusting the reconstruction program. First, the spatial frequency response was evaluated at heights of −100, −50, 0, 50, 100, and 150 mm from the IFP using the edge of a 0.3-mm-thick copper plate. Second, the spatial resolution at each height was visually evaluated using an x-ray test pattern (Model No. 38, PTW Freiburg, Germany). Third, the slice sensitivity at each height was evaluated via the wire method using a 0.1-mm-diameter tungsten wire. Phantom studies using a knee phantom and a whole-body phantom were also performed. Results: The spatial frequency response of PS-TS-F yielded the best results at the IFP and degraded slightly as the

  16. Accuracy of the Heidelberg Spectralis in the alignment between near-infrared image and tomographic scan in a model eye: a multicenter study.

    Science.gov (United States)

    Barteselli, Giulio; Bartsch, Dirk-Uwe; Viola, Francesco; Mojana, Francesca; Pellegrini, Marco; Hartmann, Kathrin I; Benatti, Eleonora; Leicht, Simon; Ratiglia, Roberto; Staurenghi, Giovanni; Weinreb, Robert N; Freeman, William R

    2013-09-01

    To evaluate temporal changes and predictors of accuracy in the alignment between simultaneous near-infrared image and optical coherence tomography (OCT) scan on the Heidelberg Spectralis using a model eye. Laboratory investigation. After calibrating the device, 6 sites performed weekly testing of the alignment for 12 weeks using a model eye. The maximum error was compared with multiple variables to evaluate predictors of inaccurate alignment. Variables included the number of weekly scanned patients, total number of OCT scans and B-scans performed, room temperature and its variation, and working time of the scanning laser. A 4-week extension study was subsequently performed to analyze short-term changes in the alignment. The average maximum error in the alignment was 15 ± 6 μm; the greatest error was 35 μm. The error increased significantly at week 1 (P = .01), specifically after the second imaging study (P alignment were temperature variation and scans per patient (P imaging study. To improve the accuracy, room temperature should be kept stable and unnecessary scans should be avoided. The alignment of the device does not need to be checked on a regular basis in the clinical setting, but it should be checked after every other patient for more precise research purposes. Published by Elsevier Inc.

  17. Possible way for increasing the quality of imaging from THz passive device

    Science.gov (United States)

    Trofimov, Vyacheslav A.; Trofimov, Vladislav V.; Deng, Chao; Zhao, Yuan-meng; Zhang, Cun-lin; Zhang, Xin

    2011-11-01

    Using the passive THz imaging system developed by the CNU-THz laboratory, we capture the passive THz image of human body with forbidden objects hidden under opaque clothes. We demonstrate the possibility of significant improving the quality of the image. Our approach bases on the application of spatial filters, developed by us for computer treatment of passive THz imaging. The THz imaging system is constructed with accordance to well known passive THz imaging principles and to the THz quasi-optical theory. It contains a scanning mechanism, which has a detector approximately with 1200μm central wavelength, a data acquisition card and a microcomputer. To get a clear imaging of object we apply a sequence of the spatial filters to the image and spectral transforms of the image. The treatment of imaging from the passive THz device is made by computer code. The performance time of treatment of the image, containing about 5000 pixels, is less than 0.1 second. To illustrate the efficiency of developed approach we detect the liquid explosive, knife, pistol and metal plate hidden under opaque clothes. The results obtained demonstrate the high efficiency of our approach for the detection and recognition of the hidden objects and are very promising for the real security application.

  18. Spatio-temporal imaging of voltage pulses with an ultrafast scanning tunneling microscope

    DEFF Research Database (Denmark)

    Jensen, Jacob Riis; Keil, Ulrich Dieter Felix; Hvam, Jørn Märcher

    1997-01-01

    Measurements on an ultrafast scanning tunneling microscope with simultaneous spatial and temporal resolution are presented. We show images of picosecond pulses propagating on a coplanar waveguide and resolve their mode structures. The influence of transmission line discontinuities on the mode...

  19. Single-photon compressive imaging with some performance benefits over raster scanning

    International Nuclear Information System (INIS)

    Yu, Wen-Kai; Liu, Xue-Feng; Yao, Xu-Ri; Wang, Chao; Zhai, Guang-Jie; Zhao, Qing

    2014-01-01

    A single-photon imaging system based on compressed sensing has been developed to image objects under ultra-low illumination. With this system, we have successfully realized imaging at the single-photon level with a single-pixel avalanche photodiode without point-by-point raster scanning. From analysis of the signal-to-noise ratio in the measurement we find that our system has much higher sensitivity than conventional ones based on point-by-point raster scanning, while the measurement time is also reduced. - Highlights: • We design a single photon imaging system with compressed sensing. • A single point avalanche photodiode is used without raster scanning. • The Poisson shot noise in the measurement is analyzed. • The sensitivity of our system is proved to be higher than that of raster scanning

  20. A semi-automatic procedure for texturing of laser scanning point clouds with google streetview images

    NARCIS (Netherlands)

    Lichtenauer, J.F.; Sirmacek, B.

    2015-01-01

    We introduce a method to texture 3D urban models with photographs that even works for Google Streetview images and can be done with currently available free software. This allows realistic texturing, even when it is not possible or cost-effective to (re)visit a scanned site to take textured scans or

  1. Defect imaging and channeling studies using channeling scanning transmission ion microscopy

    NARCIS (Netherlands)

    King, PJC; Breese, MBH; Smulders, PJM; Wilshaw, PR; Grime, GW

    The technique of channeling scanning transmission ion microscopy (CSTIM) can be used to produce images of individual crystal defects (such as dislocations and stacking faults) using the scanned, focused ion beam from a nuclear microprobe. As well as offering a new method for studies of crystal

  2. Noise characteristics of neutron images obtained by cooled CCD device

    International Nuclear Information System (INIS)

    Taniguchi, Ryoichi; Sasaki, Ryoya; Okuda, Shuichi; Okamoto, Ken-Ichi; Ogawa, Yoshihiro; Tsujimoto, Tadashi

    2009-01-01

    The noise characteristics of a cooled CCD device induced by neutron and gamma ray irradiation have been investigated. In the cooled CCD images, characteristic white spot noises (CCD noise) frequently appeared, which have a shape like a pixel in most cases and their brightness is extremely high compared with that of the image pattern. They could be divided into the two groups, fixed pattern noise (FPN) and random noise. The former always appeared in the same position in the image and the latter appeared at any position. In the background image, nearly all of the CCD noises were found to be the FPN, while many of them were the random noise during the irradiation. The random CCD noises increased with irradiation and decreased soon after the irradiation. In the case of large irradiation, a part of the CCD noise remained as the FPN. These facts suggest that the CCD noise is a phenomenon strongly relating to radiation damage of the CCD device.

  3. Single-Image Distance Measurement by a Smart Mobile Device.

    Science.gov (United States)

    Chen, Shangwen; Fang, Xianyong; Shen, Jianbing; Wang, Linbo; Shao, Ling

    2017-12-01

    Existing distance measurement methods either require multiple images and special photographing poses or only measure the height with a special view configuration. We propose a novel image-based method that can measure various types of distance from single image captured by a smart mobile device. The embedded accelerometer is used to determine the view orientation of the device. Consequently, pixels can be back-projected to the ground, thanks to the efficient calibration method using two known distances. Then the distance in pixel is transformed to a real distance in centimeter with a linear model parameterized by the magnification ratio. Various types of distance specified in the image can be computed accordingly. Experimental results demonstrate the effectiveness of the proposed method.

  4. Hybrid imaging with contrast enhanced CT scan: A nuclear physician's point of view

    International Nuclear Information System (INIS)

    Houzard, C.; Tychyj-Pinel, C.; Defez, D.; Valette, P.J.; Giammarile, F.; Houzard, C.; Valette, P.J.; Giammarile, F.

    2010-01-01

    The ongoing development of hybrid imaging, with physical association of CT scan and PET or SPECT scan, allows integrating morphological and functional information on a single exam. This important technological evolution changes diagnostic and therapeutic strategy in a major manner, essentially in oncology. The possibility to inject intravenously iodinated contrast media in order to enhance CT image contrast is still a controversial question in France. We present our experience in this domain by approaching technical problems and diagnostic advantages. (authors)

  5. Three dimensional phase imaging using a scanning optical fiber interferometer

    International Nuclear Information System (INIS)

    Walford, J.N.; Nugent, K.A.; Roberts, A.; Scholten, R.E.

    1998-01-01

    A quantitative method for measuring phase in three dimensions using a scanning optical fiber interferometer is described. By exploiting phase modulation in the reference arm, this technique is insensitive to large variations in the intensity of the field being studied, and is therefore highly suitable for measurement of phase within spatially confined optical beams. It uses only a single detector, and is not reliant on lock-in electronics. The technique is applied to the measurement of the near field of a cleaved optical fiber and shown to produce results in good agreement with theory. (authors)

  6. Digital tomosynthesis with an on-board kilovoltage imaging device

    International Nuclear Information System (INIS)

    Godfrey, Devon J.; Yin, F.-F.; Oldham, Mark; Yoo, Sua; Willett, Christopher

    2006-01-01

    Purpose: To generate on-board digital tomosynthesis (DTS) and reference DTS images for three-dimensional image-guided radiation therapy (IGRT) as an alternative to conventional portal imaging or on-board cone-beam computed tomography (CBCT). Methods and Materials: Three clinical cases (prostate, head-and-neck, and liver) were selected to illustrate the capabilities of on-board DTS for IGRT. Corresponding reference DTS images were reconstructed from digitally reconstructed radiographs computed from planning CT image sets. The effect of scan angle on DTS slice thickness was examined by computing the mutual information between coincident CBCT and DTS images, as the DTS scan angle was varied from 0 o to 165 o . A breath-hold DTS acquisition strategy was implemented to remove respiratory motion artifacts. Results: Digital tomosynthesis slices appeared similar to coincident CBCT planes and yielded substantially more anatomic information than either kilovoltage or megavoltage radiographs. Breath-hold DTS acquisition improved soft-tissue visibility by suppressing respiratory motion. Conclusions: Improved bony and soft-tissue visibility in DTS images is likely to improve target localization compared with radiographic verification techniques and might allow for daily localization of a soft-tissue target. Breath-hold DTS is a potential alternative to on-board CBCT for sites prone to respiratory motion

  7. Relationship Between the Elevated Muscle FDG Uptake in the Distal Upper Extremities on PET/CT Scan and Prescan Utilization of Mobile Devices in Young Patients.

    Science.gov (United States)

    Bai, Xia; Wang, Xuemei; Zhuang, Hongming

    2018-03-01

    It is common to notice increased FDG activity in the muscles of the forearms or hands on PET/CT images. The purpose of this study was to determine relationship between the prevalence of increased FDG activity in the forearms or hands and using mobile devices prior to the FDG PET/CT study. A total of 443 young patients with ages between 5 and 19 years who underwent FDG PET/CT scan were included in this retrospective analysis. All patients had FDG PET/CT with their arms within the field of views. The images were reviewed for elevated activity in the muscles of the distal upper extremities (DUEs), which include forearms and hands. The preimaging questionnaire/interview records regarding using mobile devices prior to FDG PET/CT were also reviewed and compared with the imaging findings. Most patients (72.0% [319/443]) used mobile devices more than 60 minutes in the period of 24 hours prior to the FDG PET/CT study. Elevated uptake in the muscles in the DUEs was observed in 38.6% (123/319) of these patients. In contrast, among 124 patients who did not use the mobile devices or used the mobile device minimally prior to the study, only 6.5% (8/124) of them had elevated FDG activity in the DUEs. The difference persisted following stratification analysis for sex, age, and serum glucose level in our patient population. Increased FDG uptake in the muscles of the DUEs in young patients is commonly seen in those who used mobile devices prior to PET/CT study. Recommendation should be considered to reduce using mobile devices prior to FDG PET/CT study in young patient population.

  8. Making Image More Energy Efficient for OLED Smart Devices

    Directory of Open Access Journals (Sweden)

    Deguang Li

    2016-01-01

    Full Text Available Now, more and more mobile smart devices are emerging massively; energy consumption of these devices has become an important consideration due to the limitation of battery capacity. Displays are the dominant energy consuming component of battery-operated devices, giving rise to organic light-emitting diode (OLED as a new promising display technology, which consumes different power when displaying different content due to their emissive nature. Based on this property, we propose an approach to improve image energy efficiency on OLED displays by perceiving image content. The key idea of our approach is to eliminate undesired details while preserving the region of interest of the image by leveraging the color and spatial information. First, we use edge detection algorithm to extract region of interest (ROI of an image. Next, we gradually change luminance and saturation of region of noninterest (NON-ROI of the image. Then we perform detailed experiment and case study to validate our approach; experiment results show that our approach can save 22.5% energy on average while preserving high quality of the image.

  9. Unsynchronized scanning with a low-cost laser range finder for real-time range imaging

    Science.gov (United States)

    Hatipoglu, Isa; Nakhmani, Arie

    2017-06-01

    Range imaging plays an essential role in many fields: 3D modeling, robotics, heritage, agriculture, forestry, reverse engineering. One of the most popular range-measuring technologies is laser scanner due to its several advantages: long range, high precision, real-time measurement capabilities, and no dependence on lighting conditions. However, laser scanners are very costly. Their high cost prevents widespread use in applications. Due to the latest developments in technology, now, low-cost, reliable, faster, and light-weight 1D laser range finders (LRFs) are available. A low-cost 1D LRF with a scanning mechanism, providing the ability of laser beam steering for additional dimensions, enables to capture a depth map. In this work, we present an unsynchronized scanning with a low-cost LRF to decrease scanning period and reduce vibrations caused by stop-scan in synchronized scanning. Moreover, we developed an algorithm for alignment of unsynchronized raw data and proposed range image post-processing framework. The proposed technique enables to have a range imaging system for a fraction of the price of its counterparts. The results prove that the proposed method can fulfill the need for a low-cost laser scanning for range imaging for static environments because the most significant limitation of the method is the scanning period which is about 2 minutes for 55,000 range points (resolution of 250x220 image). In contrast, scanning the same image takes around 4 minutes in synchronized scanning. Once faster, longer range, and narrow beam LRFs are available, the methods proposed in this work can produce better results.

  10. Mechanical scanning in intravascular ultrasound imaging: Artifacts and driving mechanisms

    NARCIS (Netherlands)

    H. ten Hoff (H.); E.J. Gussenhoven (Elma); C.M. Korbijn (Carin); F. Mastik (Frits); C.T. Lancée (Charles); N. Bom (Klaas)

    1995-01-01

    textabstractObjective: Currently, intravascular ultrasound (US) imaging catheters are developed and produced to provide a complementary diagnostic method in the treatment of blood vessel obstructive disease. Typical catheter dimensions are a diameter of 1–2.5 mm and a length of 1–1.5 m. A real-time

  11. Automated detection of delamination and disbond from wavefield images obtained using a scanning laser vibrometer

    International Nuclear Information System (INIS)

    Sohn, H; Yang, J Y; Dutta, D; DeSimio, M; Olson, S; Swenson, E

    2011-01-01

    The paper presents signal and image processing algorithms to automatically detect delamination and disbond in composite plates from wavefield images obtained using a scanning laser Doppler vibrometer (LDV). Lamb waves are excited by a lead zirconate titanate transducer (PZT) mounted on the surface of a composite plate, and the out-of-plane velocity field is measured using an LDV. From the scanned time signals, wavefield images are constructed and processed to study the interaction of Lamb waves with hidden delaminations and disbonds. In particular, the frequency–wavenumber (f–k) domain filter and the Laplacian image filter are used to enhance the visibility of defects in the scanned images. Thereafter, a statistical cluster detection algorithm is used to identify the defect location and distinguish damaged specimens from undamaged ones

  12. Technical considerations on scanning and image analysis for amyloid PET in dementia

    International Nuclear Information System (INIS)

    Akamatsu, Go; Ohnishi, Akihito; Aita, Kazuki; Ikari, Yasuhiko; Senda, Michio; Yamamoto, Yasuji

    2017-01-01

    Brain imaging techniques, such as computed tomography (CT), magnetic resonance imaging (MRI), single photon emission computed tomography (SPECT), and positron emission tomography (PET), can provide essential and objective information for the early and differential diagnosis of dementia. Amyloid PET is especially useful to evaluate the amyloid-β pathological process as a biomarker of Alzheimer's disease. This article reviews critical points about technical considerations on the scanning and image analysis methods for amyloid PET. Each amyloid PET agent has its own proper administration instructions and recommended uptake time, scan duration, and the method of image display and interpretation. In addition, we have introduced general scanning information, including subject positioning, reconstruction parameters, and quantitative and statistical image analysis. We believe that this article could make amyloid PET a more reliable tool in clinical study and practice. (author)

  13. Comparative study of image contrast in scanning electron microscope and helium ion microscope.

    Science.gov (United States)

    O'Connell, R; Chen, Y; Zhang, H; Zhou, Y; Fox, D; Maguire, P; Wang, J J; Rodenburg, C

    2017-12-01

    Images of Ga + -implanted amorphous silicon layers in a 110 n-type silicon substrate have been collected by a range of detectors in a scanning electron microscope and a helium ion microscope. The effects of the implantation dose and imaging parameters (beam energy, dwell time, etc.) on the image contrast were investigated. We demonstrate a similar relationship for both the helium ion microscope Everhart-Thornley and scanning electron microscope Inlens detectors between the contrast of the images and the Ga + density and imaging parameters. These results also show that dynamic charging effects have a significant impact on the quantification of the helium ion microscope and scanning electron microscope contrast. © 2017 The Authors Journal of Microscopy © 2017 Royal Microscopical Society.

  14. Technical Considerations on Scanning and Image Analysis for Amyloid PET in Dementia.

    Science.gov (United States)

    Akamatsu, Go; Ohnishi, Akihito; Aita, Kazuki; Ikari, Yasuhiko; Yamamoto, Yasuji; Senda, Michio

    2017-01-01

    Brain imaging techniques, such as computed tomography (CT), magnetic resonance imaging (MRI), single photon emission computed tomography (SPECT), and positron emission tomography (PET), can provide essential and objective information for the early and differential diagnosis of dementia. Amyloid PET is especially useful to evaluate the amyloid-β pathological process as a biomarker of Alzheimer's disease. This article reviews critical points about technical considerations on the scanning and image analysis methods for amyloid PET. Each amyloid PET agent has its own proper administration instructions and recommended uptake time, scan duration, and the method of image display and interpretation. In addition, we have introduced general scanning information, including subject positioning, reconstruction parameters, and quantitative and statistical image analysis. We believe that this article could make amyloid PET a more reliable tool in clinical study and practice.

  15. 77 FR 38829 - Certain Electronic Imaging Devices; Institution of Investigation

    Science.gov (United States)

    2012-06-29

    ... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-850] Certain Electronic Imaging Devices; Institution of Investigation AGENCY: U.S. International Trade Commission. ACTION: Notice. SUMMARY: Notice is hereby given that a complaint was filed with the U.S. International Trade Commission on May 23, 2012...

  16. Characterisation of a CMOS charge transfer device for TDI imaging

    International Nuclear Information System (INIS)

    Rushton, J.; Holland, A.; Stefanov, K.; Mayer, F.

    2015-01-01

    The performance of a prototype true charge transfer imaging sensor in CMOS is investigated. The finished device is destined for use in TDI applications, especially Earth-observation, and to this end radiation tolerance must be investigated. Before this, complete characterisation is required. This work starts by looking at charge transfer inefficiency and then investigates responsivity using mean-variance techniques

  17. Underwater 3D Surface Measurement Using Fringe Projection Based Scanning Devices.

    Science.gov (United States)

    Bräuer-Burchardt, Christian; Heinze, Matthias; Schmidt, Ingo; Kühmstedt, Peter; Notni, Gunther

    2015-12-23

    In this work we show the principle of optical 3D surface measurements based on the fringe projection technique for underwater applications. The challenges of underwater use of this technique are shown and discussed in comparison with the classical application. We describe an extended camera model which takes refraction effects into account as well as a proposal of an effective, low-effort calibration procedure for underwater optical stereo scanners. This calibration technique combines a classical air calibration based on the pinhole model with ray-based modeling and requires only a few underwater recordings of an object of known length and a planar surface. We demonstrate a new underwater 3D scanning device based on the fringe projection technique. It has a weight of about 10 kg and the maximal water depth for application of the scanner is 40 m. It covers an underwater measurement volume of 250 mm × 200 mm × 120 mm. The surface of the measurement objects is captured with a lateral resolution of 150 μm in a third of a second. Calibration evaluation results are presented and examples of first underwater measurements are given.

  18. Endoscopic device for functional imaging of the retina

    Science.gov (United States)

    Barriga, Simon; Lohani, Sweyta; Martell, Bret; Soliz, Peter; Ts'o, Dan

    2011-03-01

    Non-invasive imaging of retinal function based on the recording of spatially distributed reflectance changes evoked by visual stimuli has to-date been performed primarily using modified commercial fundus cameras. We have constructed a prototype retinal functional imager, using a commercial endoscope (Storz) for the frontend optics, and a low-cost back-end that includes the needed dichroic beam splitter to separate the stimulus path from the imaging path. This device has been tested to demonstrate its performance for the delivery of adequate near infrared (NIR) illumination, intensity of the visual stimulus and reflectance return in the imaging path. The current device was found to be capable of imaging reflectance changes of 0.1%, similar to that observable using the modified commercial fundus camera approach. The visual stimulus (a 505nm spot of 0.5secs) was used with an interrogation illumination of 780nm, and a sequence of imaged captured. At each pixel, the imaged signal was subtracted and normalized by the baseline reflectance, so that the measurement was ΔR/R. The typical retinal activity signal observed had a ΔR/R of 0.3-1.0%. The noise levels were measured when no stimulus was applied and found to vary between +/- 0.05%. Functional imaging has been suggested as a means to provide objective information on retina function that may be a preclinical indicator of ocular diseases, such as age-related macular degeneration (AMD), glaucoma, and diabetic retinopathy. The endoscopic approach promises to yield a significantly more economical retinal functional imaging device that would be clinically important.

  19. The con focal laser scanning microscope: a powerful tool for the investigation of micro devices and nano structures

    International Nuclear Information System (INIS)

    Montereali, R.M.; Baldacchini, G.; Bonfigli, F.; Vincenti, M.A.; Almaviva, S.

    2008-01-01

    In the last years the Con focal Laser Scanning Microscope (CLSM), a versatile and powerful optical instrument, gained a strong increase of interest in the scientific community, not only for biological applications, but also for the characterization of materials, microstructures and devices. The conditions that favoured its wide diffusion are surely the large availability of laser sources and powerful computer-imaging and data-processing systems at relatively low cost; however, the main reason that contributed to its popularity is the ability to obtain tri dimensional reconstruction of a great variety of biological and non-biological samples with sub micrometric resolution. In this report we show the main properties and characteristics of the Con focal Microscope Nikon Eclipse 80-i C1, which has operated sinc more than two years in the Solid State Laser and Spectroscopy Laboratory of the ENEA Research Center in Frascati. Some of the results obtained in the characterization of luminescent micro and nano structures based on lithium fluoride color centers will be presented [it

  20. Effect of blood glucose levels on image quality in 18F fluorodeoxyglucose scanning - a case report

    International Nuclear Information System (INIS)

    Szeto, E.; Keane, J.

    2000-01-01

    Full text: In December last year, a 71-year-old gentleman presented to the Nuclear Medicine Department at St Vincent's Hospital, Sydney for an FDG coincidence detection positron emission scan. The patient had cancer of the lung with a large lesion in the left upper lobe and a small lesion in the right middle lobe. On initial investigation, this patient had a blood sugar level of 17mmol/L which was eventually reduced to 6.7mmol/L just prior to scanning. The patient was then asked to return to be rescanned without his blood sugar levels being adjusted. Just prior to his second scan, his blood sugar level was 15.4mmollL. The aim of the initial scan being repeated was to see just how important a role blood sugar levels play in the quality of a Co Pet scan. The first scan showed excellent image quality while the repeated scan showed markedly inferior image quality due to unwanted soft tissue FDG uptake. In conclusion, blood sugar levels play a significant role in output image quality in FDG coincidence detection positron emission scanning. Copyright (2000) The Australian and New Zealand Society of Nuclear Medicine Inc

  1. Low-dose computed tomography image restoration using previous normal-dose scan

    International Nuclear Information System (INIS)

    Ma, Jianhua; Huang, Jing; Feng, Qianjin; Zhang, Hua; Lu, Hongbing; Liang, Zhengrong; Chen, Wufan

    2011-01-01

    Purpose: In current computed tomography (CT) examinations, the associated x-ray radiation dose is of a significant concern to patients and operators. A simple and cost-effective means to perform the examinations is to lower the milliampere-seconds (mAs) or kVp parameter (or delivering less x-ray energy to the body) as low as reasonably achievable in data acquisition. However, lowering the mAs parameter will unavoidably increase data noise and the noise would propagate into the CT image if no adequate noise control is applied during image reconstruction. Since a normal-dose high diagnostic CT image scanned previously may be available in some clinical applications, such as CT perfusion imaging and CT angiography (CTA), this paper presents an innovative way to utilize the normal-dose scan as a priori information to induce signal restoration of the current low-dose CT image series. Methods: Unlike conventional local operations on neighboring image voxels, nonlocal means (NLM) algorithm utilizes the redundancy of information across the whole image. This paper adapts the NLM to utilize the redundancy of information in the previous normal-dose scan and further exploits ways to optimize the nonlocal weights for low-dose image restoration in the NLM framework. The resulting algorithm is called the previous normal-dose scan induced nonlocal means (ndiNLM). Because of the optimized nature of nonlocal weights calculation, the ndiNLM algorithm does not depend heavily on image registration between the current low-dose and the previous normal-dose CT scans. Furthermore, the smoothing parameter involved in the ndiNLM algorithm can be adaptively estimated based on the image noise relationship between the current low-dose and the previous normal-dose scanning protocols. Results: Qualitative and quantitative evaluations were carried out on a physical phantom as well as clinical abdominal and brain perfusion CT scans in terms of accuracy and resolution properties. The gain by the use

  2. Scanning ion images; analysis of pharmaceutical drugs at organelle levels

    Science.gov (United States)

    Larras-Regard, E.; Mony, M.-C.

    1995-05-01

    With the ion analyser IMS 4F used in microprobe mode, it is possible to obtain images of fields of 10 × 10 [mu]m2, corresponding to an effective magnification of 7000 with lateral resolution of 250 nm, technical characteristics that are appropriate for the size of cell organelles. It is possible to characterize organelles by their relative CN-, P- and S- intensities when the tissues are prepared by freeze fixation and freeze substitution. The recognition of organelles enables correlation of the tissue distribution of ebselen, a pharmaceutical drug containing selenium. The various metabolites characterized in plasma, bile and urine during biotransformation of ebselen all contain selenium, so the presence of the drug and its metabolites can be followed by images of Se. We were also able to detect the endogenous content of Se in tissue, due to the increased sensitivity of ion analysis in microprobe mode. Our results show a natural occurrence of Se in the border corresponding to the basal lamina of cells of proximal but not distal tubules of the kidney. After treatment of rats with ebselen, an additional site of Se is found in the lysosomes. We suggest that in addition to direct elimination of ebselen and its metabolites by glomerular filtration and urinary elimination, a second process of elimination may occur: Se compounds reaching the epithelial cells via the basal lamina accumulate in lysosomes prior to excretion into the tubular fluid. The technical developments of using the IMS 4F instrument in the microprobe mode and the improvement in preparation of samples by freeze fixation and substitution further extend the limit of ion analysis in biology. Direct imaging of trace elements and molecules marked with a tracer make it possible to determine their targets by comparison with images of subcellular structures. This is a promising advance in the study of pathways of compounds within tissues, cells and the whole organism.

  3. Image timing and detector performance of a matrix ion-chamber electronic portal imaging device

    International Nuclear Information System (INIS)

    Greer, P.

    1996-01-01

    The Oncology Centre of Auckland Hospital recently purchased a Varian PortalVision TM electronic portal imaging device (EPID). Image acquisition times, input-output characteristics and contrast-detail curves of this matrix liquid ion-chamber EPID have been measured to examine the variation in imaging performance with acquisition mode. The variation in detector performance with acquisition mode has been examined. The HV cycle time can be increased to improve image quality. Consideration should be given to the acquisition mode and HV cycle time used when imaging to ensure adequate imaging performance with reasonable imaging time. (author)

  4. Real-time computer treatment of THz passive device images with the high image quality

    Science.gov (United States)

    Trofimov, Vyacheslav A.; Trofimov, Vladislav V.

    2012-06-01

    We demonstrate real-time computer code improving significantly the quality of images captured by the passive THz imaging system. The code is not only designed for a THz passive device: it can be applied to any kind of such devices and active THz imaging systems as well. We applied our code for computer processing of images captured by four passive THz imaging devices manufactured by different companies. It should be stressed that computer processing of images produced by different companies requires using the different spatial filters usually. The performance of current version of the computer code is greater than one image per second for a THz image having more than 5000 pixels and 24 bit number representation. Processing of THz single image produces about 20 images simultaneously corresponding to various spatial filters. The computer code allows increasing the number of pixels for processed images without noticeable reduction of image quality. The performance of the computer code can be increased many times using parallel algorithms for processing the image. We develop original spatial filters which allow one to see objects with sizes less than 2 cm. The imagery is produced by passive THz imaging devices which captured the images of objects hidden under opaque clothes. For images with high noise we develop an approach which results in suppression of the noise after using the computer processing and we obtain the good quality image. With the aim of illustrating the efficiency of the developed approach we demonstrate the detection of the liquid explosive, ordinary explosive, knife, pistol, metal plate, CD, ceramics, chocolate and other objects hidden under opaque clothes. The results demonstrate the high efficiency of our approach for the detection of hidden objects and they are a very promising solution for the security problem.

  5. Background Noise Removal in Ultrasonic B-scan Images Using Iterative Statistical Techniques

    NARCIS (Netherlands)

    Wells, I.; Charlton, P. C.; Mosey, S.; Donne, K. E.

    2008-01-01

    The interpretation of ultrasonic B-scan images can be a time-consuming process and its success depends on operator skills and experience. Removal of the image background will potentially improve its quality and hence improve operator diagnosis. An automatic background noise removal algorithm is

  6. A simple methodology for obtaining X-ray color images in scanning electron microscopy

    International Nuclear Information System (INIS)

    Veiga, M.M. da; Pietroluongo, L.R.V.

    1985-01-01

    A simple methodology for obtaining at least 3 elements X-ray images in only one photography is described. The fluorescent X-ray image is obtained from scanning electron microscopy with energy dispersion analysis system. The change of detector analytic channels, color cellophane foils and color films are used sequentially. (M.C.K.) [pt

  7. A robust method for processing scanning probe microscopy images and determining nanoobject position and dimensions

    NARCIS (Netherlands)

    Silly, F.

    2009-01-01

    P>Processing of scanning probe microscopy (SPM) images is essential to explore nanoscale phenomena. Image processing and pattern recognition techniques are developed to improve the accuracy and consistency of nanoobject and surface characterization. We present a robust and versatile method to

  8. Line-Scan Hyperspectral Imaging Techniques for Food Safety and Quality Applications

    Directory of Open Access Journals (Sweden)

    Jianwei Qin

    2017-01-01

    Full Text Available Hyperspectral imaging technologies in the food and agricultural area have been evolving rapidly over the past 15 years owing to tremendous interest from both academic and industrial fields. Line-scan hyperspectral imaging is a major method that has been intensively researched and developed using different physical principles (e.g., reflectance, transmittance, fluorescence, Raman, and spatially resolved spectroscopy and wavelength regions (e.g., visible (VIS, near infrared (NIR, and short-wavelength infrared (SWIR. Line-scan hyperspectral imaging systems are mainly developed and used for surface inspection of food and agricultural products using area or line light sources. Some of these systems can also be configured to conduct spatially resolved spectroscopy measurements for internal or subsurface food inspection using point light sources. This paper reviews line-scan hyperspectral imaging techniques, with introduction, demonstration, and summarization of existing and emerging techniques for food and agricultural applications. The main topics include related spectroscopy techniques, line-scan measurement methods, hardware components and systems, system calibration methods, and spectral and image analysis techniques. Applications in food safety and quality are also presented to reveal current practices and future trends of line-scan hyperspectral imaging techniques.

  9. Improving image quality by accounting for changes in water temperature during a photoacoustic tomography scan.

    Directory of Open Access Journals (Sweden)

    Dominique Van de Sompel

    Full Text Available The emerging field of photoacoustic tomography is rapidly evolving with many new system designs and reconstruction algorithms being published. Many systems use water as a coupling medium between the scanned object and the ultrasound transducers. Prior to a scan, the water is heated to body temperature to enable small animal imaging. During the scan, the water heating system of some systems is switched off to minimize the risk of bubble formation, which leads to a gradual decrease in water temperature and hence the speed of sound. In this work, we use a commercially available scanner that follows this procedure, and show that a failure to model intra-scan temperature decreases as small as 1.5°C leads to image artifacts that may be difficult to distinguish from true structures, particularly in complex scenes. We then improve image quality by continuously monitoring the water temperature during the scan and applying variable speed of sound corrections in the image reconstruction algorithm. While upgrading to an air bubble-free heating pump and keeping it running during the scan could also solve the changing temperature problem, we show that a software correction for the temperature changes provides a cost-effective alternative to a hardware upgrade. The efficacy of the software corrections was shown to be consistent across objects of widely varying appearances, namely physical phantoms, ex vivo tissue, and in vivo mouse imaging. To the best of our knowledge, this is the first study to demonstrate the efficacy of modeling temporal variations in the speed of sound during photoacoustic scans, as opposed to spatial variations as focused on by previous studies. Since air bubbles pose a common problem in ultrasonic and photoacoustic imaging systems, our results will be useful to future small animal imaging studies that use scanners with similarly limited heating units.

  10. Electronics Related to Nuclear Medicine Imaging Devices. Chapter 7

    Energy Technology Data Exchange (ETDEWEB)

    Ott, R. J. [Joint Department of Physics, Royal Marsden Hospital and Institute of Cancer Research, Surrey (United Kingdom); Stephenson, R. [Rutherford Appleton Laboratory, Oxfordshire (United Kingdom)

    2014-12-15

    Nuclear medicine imaging is generally based on the detection of X rays and γ rays emitted by radionuclides injected into a patient. In the previous chapter, the methods used to detect these photons were described, based most commonly on a scintillation counter although there are imaging devices that use either gas filled ionization detectors or semiconductors. Whatever device is used, nuclear medicine images are produced from a very limited number of photons, due mainly to the level of radioactivity that can be safely injected into a patient. Hence, nuclear medicine images are usually made from many orders of magnitude fewer photons than X ray computed tomography (CT) images, for example. However, as the information produced is essentially functional in nature compared to the anatomical detail of CT, the apparently poorer image quality is overcome by the nature of the information produced. The low levels of photons detected in nuclear medicine means that photon counting can be performed. Here each photon is detected and analysed individually, which is especially valuable, for example, in enabling scattered photons to be rejected. This is in contrast to X ray imaging where images are produced by integrating the flux entering the detectors. Photon counting, however, places a heavy burden on the electronics used for nuclear medicine imaging in terms of electronic noise and stability. This chapter will discuss how the signals produced in the primary photon detection process can be converted into pulses providing spatial, energy and timing information, and how this information is used to produce both qualitative and quantitative images.

  11. Correlation between image quality of CT scan and amount of intravenous contrast media

    International Nuclear Information System (INIS)

    Yoon, Dae Young; Choi, Dae Seob; Kim, Seung Hyup; Han, Joon Koo; Choi, Byung Ihn; Im, Jung Gi; Han, Moon Hee; Chang, Kee Hyun; Kim, Jong Hyo; Han, Man Chung

    1993-01-01

    A blind, comparative clinical study was performed prospectively to examine the correlation between image quality of CT scan in terms of contrast enhancement effect and amount of intravenous contrast media. A total of 357 patients were randomized into two groups. Ionic high-osmolality contrast media (68% meglumine ioglicate) was administered intravenously as 100 ml bolus in one group and as 50 ml bolus in the other group. Statistically significant differences of image quality were found in CT scans of the brain, head and neck, chest and abdomen (p 0.05). We suggest that amount of contrast media may be reduced in pelvis CT without significant degradation of image quality

  12. Imaging of buried phosphorus nanostructures in silicon using scanning tunneling microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Oberbeck, Lars [Centre for Quantum Computation and Communication Technology, School of Physics, University of New South Wales, Sydney, New South Wales 2052 (Australia); TOTAL Marketing Services, New Energies, La Défense 10, 92069 Paris La Défense Cedex (France); Reusch, Thilo C. G.; Hallam, Toby; Simmons, Michelle Y., E-mail: n.curson@ucl.ac.uk, E-mail: michelle.simmons@unsw.edu.au [Centre for Quantum Computation and Communication Technology, School of Physics, University of New South Wales, Sydney, New South Wales 2052 (Australia); Schofield, Steven R. [Centre for Quantum Computation and Communication Technology, School of Physics, University of New South Wales, Sydney, New South Wales 2052 (Australia); London Centre for Nanotechnology, UCL, London WC1H 0AH (United Kingdom); Department of Physics and Astronomy, UCL, London WC1E 6BT (United Kingdom); Curson, Neil J., E-mail: n.curson@ucl.ac.uk, E-mail: michelle.simmons@unsw.edu.au [Centre for Quantum Computation and Communication Technology, School of Physics, University of New South Wales, Sydney, New South Wales 2052 (Australia); London Centre for Nanotechnology, UCL, London WC1H 0AH (United Kingdom); Department of Electronic and Electrical Engineering, UCL, London WC1E 7JE (United Kingdom)

    2014-06-23

    We demonstrate the locating and imaging of single phosphorus atoms and phosphorus dopant nanostructures, buried beneath the Si(001) surface using scanning tunneling microscopy. The buried dopant nanostructures have been fabricated in a bottom-up approach using scanning tunneling microscope lithography on Si(001). We find that current imaging tunneling spectroscopy is suited to locate and image buried nanostructures at room temperature and with residual surface roughness present. From these studies, we can place an upper limit on the lateral diffusion during encapsulation with low-temperature Si molecular beam epitaxy.

  13. Imaging of buried phosphorus nanostructures in silicon using scanning tunneling microscopy

    International Nuclear Information System (INIS)

    Oberbeck, Lars; Reusch, Thilo C. G.; Hallam, Toby; Simmons, Michelle Y.; Schofield, Steven R.; Curson, Neil J.

    2014-01-01

    We demonstrate the locating and imaging of single phosphorus atoms and phosphorus dopant nanostructures, buried beneath the Si(001) surface using scanning tunneling microscopy. The buried dopant nanostructures have been fabricated in a bottom-up approach using scanning tunneling microscope lithography on Si(001). We find that current imaging tunneling spectroscopy is suited to locate and image buried nanostructures at room temperature and with residual surface roughness present. From these studies, we can place an upper limit on the lateral diffusion during encapsulation with low-temperature Si molecular beam epitaxy.

  14. Research on Radar Cross Section Measurement Based on Near-field Imaging of Cylindrical Scanning

    Directory of Open Access Journals (Sweden)

    Xing Shu-guang

    2015-04-01

    Full Text Available A new method of Radar Cross Section (RCS measurement based on near-field imaging of cylindrical scanning surface is proposed. The method is based on the core assumption that the target consists of ideal isotropic scattered centers. Three-dimensional radar scattered images are obtained by using the proposed method, and then to obtain the RCS of the target, the scattered far field is calculated by summing the fields generated by the equivalent scattered centers. Not only three dimensional radar reflectivity images but also the RCS of targets in certain three dimensional angle areas can be obtained. Compared with circular scanning that can only obtain twodimensional radar reflectivity images and RCS results in two-dimensional angle areas, cylindrical scanning can provide more information about the scattering properties of the targets. The method has strong practicability and its validity is verified by simulations.

  15. Ultrasonic signal processing and B-SCAN imaging for nondestructive testing. Application to under - cladding - cracks

    International Nuclear Information System (INIS)

    Theron, G.

    1988-02-01

    Crack propagation under the stainless steel cladding of nuclear reactor vessels is monitored by ultrasonic testing. This work study signal processing to improve detection and sizing of defects. Two possibilities are examined: processing of each individual signal and simultaneous processing of all the signals giving a B-SCAN image. The bibliographic study of time-frequency methods shows that they are not suitable for pulses. Then decomposition in instantaneous frequency and envelope is used. Effect of interference of 2 close echoes on instantaneous frequency is studies. The deconvolution of B-SCAN images is obtained by the transducer field. A point-by-point deconvolution method, less noise sensitive, is developed. B-SCAN images are processed in 2 phases: interface signal processing and deconvolution. These calculations improve image accuracy and dynamics. Water-stell interface and ferritic-austenitic interface are separated. Echoes of crack top are visualized and crack-hole differentiation is improved [fr

  16. Modern technologies for retinal scanning and imaging: an introduction for the biomedical engineer

    Science.gov (United States)

    2014-01-01

    This review article is meant to help biomedical engineers and nonphysical scientists better understand the principles of, and the main trends in modern scanning and imaging modalities used in ophthalmology. It is intended to ease the communication between physicists, medical doctors and engineers, and hopefully encourage “classical” biomedical engineers to generate new ideas and to initiate projects in an area which has traditionally been dominated by optical physics. Most of the methods involved are applicable to other areas of biomedical optics and optoelectronics, such as microscopic imaging, spectroscopy, spectral imaging, opto-acoustic tomography, fluorescence imaging etc., all of which are with potential biomedical application. Although all described methods are novel and important, the emphasis of this review has been placed on three technologies introduced in the 1990’s and still undergoing vigorous development: Confocal Scanning Laser Ophthalmoscopy, Optical Coherence Tomography, and polarization-sensitive retinal scanning. PMID:24779618

  17. Non-invasive and high-sensitivity scanning detection of magnetic nanoparticles in animals using high-Tc scanning superconducting-quantum-interference-device biosusceptometry.

    Science.gov (United States)

    Chieh, J J; Hong, C Y

    2011-08-01

    Although magnetic nanoparticles (MNPs) have been widely applied to animals in biomedicine, MNPs within animals should be examined in real time, in vivo, and without bio-damaged possibility to evaluate whether the bio-function of MNPs is valid or to further controls the biomedicinal process because of accompanying complex problems such as MNPs distribution and MNPs biodegradation. The non-invasive and high-sensitivity scanning detection of MNPs in animals using ac susceptometry based on a high-T(c) superconducting quantum interference device (SQUID) is presented. The non-invasive results and biopsy results show good agreement, and two gold-standard biomedicine methods, Prussian blue stain and inductively coupled plasma, prove the magnetic results. This confirms that the future clinical diagnosis of bio-functional MNPs could be operated by using scanning SQUID biosusceptometry as conveniently as an ultrasonic probe.

  18. Gills scanning images of the seawater fish Eugerres brasilianus (Gerreidae

    Directory of Open Access Journals (Sweden)

    Daura Regina Eiras-Stofella

    2000-01-01

    Full Text Available The gills of the adult fish, Eugerres brasilianus (Gerreidae were analyzed in a scanning electron microscope. The stratified epithelium was uniform on all parts of the branchial arch. Concentric microridges were present on cells that form this epithelium and were mainly observed in the primary lamellae and pharyngeal region where mucous cells were also abundant. The ultrastructural features of E. brasilianus gills indicated that this was not a filtering species, and that the feeding habit included mainly the intake of small organisms. The results presently obtained agreed with other literature data which determined the feeding habit of this species by means of stomach content analysis and other aspects.Peixes adultos da espécie Eugerres brasilianus (Gerreidae tiveram suas brânquias analisadas em microscópio eletrônico de varredura. O epitélio de revestimento é uniforme em todas as porções dos arcos. É formado por células com micropregas concêntricas principalmente nas lamelas primárias e na região faríngea, locais onde são abundantes as células que secretam muco. A caracterização ultra-estrutural das brânquias de E. brasilianus indica que a espécie não é filtradora e que em sua alimentação deve predominar a ingestão de pequenos organismos. Esses resultados estão de acordo com os dados da literatura que determinam o hábito alimentar da espécie através de análises de conteúdo estomacal e outros aspectos.

  19. Evaluation of Yogurt Microstructure Using Confocal Laser Scanning Microscopy and Image Analysis

    DEFF Research Database (Denmark)

    Skytte, Jacob Lercke; Ghita, Ovidiu; Whelan, Paul F.

    2015-01-01

    The microstructure of protein networks in yogurts defines important physical properties of the yogurt and hereby partly its quality. Imaging this protein network using confocal scanning laser microscopy (CSLM) has shown good results, and CSLM has become a standard measuring technique for fermented...... to image texture description. Here, CSLM images from a yogurt fermentation study are investigated, where production factors including fat content, protein content, heat treatment, and incubation temperature are varied. The descriptors are evaluated through nearest neighbor classification, variance analysis...... scanning microscopy images can be used to provide information on the protein microstructure in yogurt products. For large numbers of microscopy images, subjective evaluation becomes a difficult or even impossible approach, if the images should be incorporated in any form of statistical analysis alongside...

  20. The optical-mechanical design of DMD modulation imaging device

    Science.gov (United States)

    Li, Tianting; Xu, Xiping; Qiao, Yang; Li, Lei; Pan, Yue

    2014-09-01

    In order to avoid the phenomenon of some image information were lost, which is due to the jamming signals, such as incident laser, make the pixels dot on CCD saturated. In this article a device of optical-mechanical structure was designed, which utilized the DMD (Digital Micro mirror Device) to modulate the image. The DMD reflection imaging optical system adopts the telecentric light path. However, because the design is not only required to guarantee a 66° angle between the optical axis of the relay optics and the DMD, but also to ensure that the optical axis of the projection system keeps parallel with the perpendicular bisector of the micro-mirror which is in the "flat" state, so the TIR prism is introduced,and making the relay optics and the DMD satisfy the optical institution's requirements. In this paper, a mechanical structure of the imaging optical system was designed and at the meanwhile the lens assembly has been well connected and fixed and fine-tuned by detailed structural design, which included the tilt decentered lens, wedge flanges, prisms. By optimizing the design, the issues of mutual restraint between the inverting optical system and the projecting system were well resolved, and prevented the blocking of the two systems. In addition, the structure size of the whole DMD reflection imaging optical system was minimized; it reduced the energy loss and ensured the image quality.

  1. Analysis of patient setup accuracy using electronic portal imaging device

    International Nuclear Information System (INIS)

    Onogi, Yuzo; Aoki, Yukimasa; Nakagawa, Keiichi

    1996-01-01

    Radiation therapy is performed in many fractions, and accurate patient setup is very important. This is more significant nowadays because treatment planning and radiation therapy are more precisely performed. Electronic portal imaging devices and automatic image comparison algorithms let us analyze setup deviations quantitatively. With such in mind we developed a simple image comparison algorithm. Using 2459 electronic verification images (335 ports, 123 treatment sites) generated during the past three years at our institute, we evaluated the results of the algorithm, and analyzed setup deviations according to the area irradiated, use of a fixing device (shell), and arm position. Calculated setup deviation was verified visually and their fitness was classified into good, fair, bad, and incomplete. The result was 40%, 14%, 22%, 24% respectively. Using calculated deviations classified as good (994 images), we analyzed setup deviations. Overall setup deviations described in 1 SD along axes x, y, z, was 1.9 mm, 2.5 mm, 1.7 mm respectively. We classified these deviations into systematic and random components, and found that random error was predominant in our institute. The setup deviations along axis y (cranio-caudal direction) showed larger distribution when treatment was performed with the shell. Deviations along y (cranio-caudal) and z (anterior-posterior) had larger distribution when treatment occurred with the patient's arm elevated. There was a significant time-trend error, whose deviations become greater with time. Within all evaluated ports, 30% showed a time-trend error. Using an electronic portal imaging device and automatic image comparison algorithm, we are able to analyze setup deviations more precisely and improve setup method based on objective criteria. (author)

  2. Prospective clinical evaluation of an electronic portal imaging device

    International Nuclear Information System (INIS)

    Michalski, Jeff M.; Graham, Mary V.; Bosch, Walter R.; Wong, John; Gerber, Russell L.; Cheng, Abel; Tinger, Alfred; Valicenti, Richard K.

    1996-01-01

    Purpose: To determine whether the clinical implementation of an electronic portal imaging device can improve the precision of daily external beam radiotherapy. Methods and Materials: In 1991, an electronic portal imaging device was installed on a dual energy linear accelerator in our clinic. After training the radiotherapy technologists in the acquisition and evaluation of portal images, we performed a randomized study to determine whether online observation, interruption, and intervention would result in more precise daily setup. The patients were randomized to one of two groups: those whose treatments were actively monitored by the radiotherapy technologists and those that were imaged but not monitored. The treating technologists were instructed to correct the following treatment errors: (a) field placement error (FPE) > 1 cm; (b) incorrect block; (c) incorrect collimator setting; (d) absent customized block. Time of treatment delivery was recorded by our patient tracking and billing computers and compared to a matched set of patients not participating in the study. After the patients radiation therapy course was completed, an offline analysis of the patient setup error was planned. Results: Thirty-two patients were treated to 34 anatomical sites in this study. In 893 treatment sessions, 1,873 fields were treated (1,089 fields monitored and 794 fields unmonitored). Ninety percent of the treated fields had at least one image stored for offline analysis. Eighty-seven percent of these images were analyzed offline. Of the 1,011 fields imaged in the monitored arm, only 14 (1.4%) had an intervention recorded by the technologist. Despite infrequent online intervention, offline analysis demonstrated that the incidence of FPE > 10 mm in the monitored and unmonitored groups was 56 out of 881 (6.1%) and 95 out of 595 (11.2%), respectively; p 10 mm was confined to the pelvic fields. The time to treat patients in this study was 10.78 min (monitored) and 10.10 min (unmonitored

  3. High-resolution room-temperature sample scanning superconducting quantum interference device microscope configurable for geological and biomagnetic applications

    Science.gov (United States)

    Fong, L. E.; Holzer, J. R.; McBride, K. K.; Lima, E. A.; Baudenbacher, F.; Radparvar, M.

    2005-05-01

    We have developed a scanning superconducting quantum interference device (SQUID) microscope system with interchangeable sensor configurations for imaging magnetic fields of room-temperature (RT) samples with submillimeter resolution. The low-critical-temperature (Tc) niobium-based monolithic SQUID sensors are mounted on the tip of a sapphire and thermally anchored to the helium reservoir. A 25μm sapphire window separates the vacuum space from the RT sample. A positioning mechanism allows us to adjust the sample-to-sensor spacing from the top of the Dewar. We achieved a sensor-to-sample spacing of 100μm, which could be maintained for periods of up to four weeks. Different SQUID sensor designs are necessary to achieve the best combination of spatial resolution and field sensitivity for a given source configuration. For imaging thin sections of geological samples, we used a custom-designed monolithic low-Tc niobium bare SQUID sensor, with an effective diameter of 80μm, and achieved a field sensitivity of 1.5pT/Hz1/2 and a magnetic moment sensitivity of 5.4×10-18Am2/Hz1/2 at a sensor-to-sample spacing of 100μm in the white noise region for frequencies above 100Hz. Imaging action currents in cardiac tissue requires a higher field sensitivity, which can only be achieved by compromising spatial resolution. We developed a monolithic low-Tc niobium multiloop SQUID sensor, with sensor sizes ranging from 250μm to 1mm, and achieved sensitivities of 480-180fT /Hz1/2 in the white noise region for frequencies above 100Hz, respectively. For all sensor configurations, the spatial resolution was comparable to the effective diameter and limited by the sensor-to-sample spacing. Spatial registration allowed us to compare high-resolution images of magnetic fields associated with action currents and optical recordings of transmembrane potentials to study the bidomain nature of cardiac tissue or to match petrography to magnetic field maps in thin sections of geological samples.

  4. High-resolution, high-throughput imaging with a multibeam scanning electron microscope.

    Science.gov (United States)

    Eberle, A L; Mikula, S; Schalek, R; Lichtman, J; Knothe Tate, M L; Zeidler, D

    2015-08-01

    Electron-electron interactions and detector bandwidth limit the maximal imaging speed of single-beam scanning electron microscopes. We use multiple electron beams in a single column and detect secondary electrons in parallel to increase the imaging speed by close to two orders of magnitude and demonstrate imaging for a variety of samples ranging from biological brain tissue to semiconductor wafers. © 2015 The Authors Journal of Microscopy © 2015 Royal Microscopical Society.

  5. Audiovisual biofeedback improves image quality and reduces scan time for respiratory-gated 3D MRI

    Science.gov (United States)

    Lee, D.; Greer, P. B.; Arm, J.; Keall, P.; Kim, T.

    2014-03-01

    The purpose of this study was to test the hypothesis that audiovisual (AV) biofeedback can improve image quality and reduce scan time for respiratory-gated 3D thoracic MRI. For five healthy human subjects respiratory motion guidance in MR scans was provided using an AV biofeedback system, utilizing real-time respiratory motion signals. To investigate the improvement of respiratory-gated 3D MR images between free breathing (FB) and AV biofeedback (AV), each subject underwent two imaging sessions. Respiratory-related motion artifacts and imaging time were qualitatively evaluated in addition to the reproducibility of external (abdominal) motion. In the results, 3D MR images in AV biofeedback showed more anatomic information such as a clear distinction of diaphragm, lung lobes and sharper organ boundaries. The scan time was reduced from 401±215 s in FB to 334±94 s in AV (p-value 0.36). The root mean square variation of the displacement and period of the abdominal motion was reduced from 0.4±0.22 cm and 2.8±2.5 s in FB to 0.1±0.15 cm and 0.9±1.3 s in AV (p-value of displacement audiovisual biofeedback improves image quality and reduces scan time for respiratory-gated 3D MRI. These results suggest that AV biofeedback has the potential to be a useful motion management tool in medical imaging and radiation therapy procedures.

  6. In vivo integrated photoacoustic ophthalmoscopy, optical coherence tomography, and scanning laser ophthalmoscopy for retinal imaging

    Science.gov (United States)

    Song, Wei; Zhang, Rui; Zhang, Hao F.; Wei, Qing; Cao, Wenwu

    2012-12-01

    The physiological and pathological properties of retina are closely associated with various optical contrasts. Hence, integrating different ophthalmic imaging technologies is more beneficial in both fundamental investigation and clinical diagnosis of several blinding diseases. Recently, photoacoustic ophthalmoscopy (PAOM) was developed for in vivo retinal imaging in small animals, which demonstrated the capability of imaging retinal vascular networks and retinal pigment epithelium (RPE) at high sensitivity. We combined PAOM with traditional imaging modalities, such as fluorescein angiography (FA), spectral-domain optical coherence tomography (SD-OCT), and auto-fluorescence scanning laser ophthalmoscopy (AF-SLO), for imaging rats and mice. The multimodal imaging system provided more comprehensive evaluation of the retina based on the complementary imaging contrast mechanisms. The high-quality retinal images show that the integrated ophthalmic imaging system has great potential in the investigation of blinding disorders.

  7. [18F]fluorodeoxyglucose triple-head coincidence imaging as an adjunct to 131I scanning for follow-up of papillary thyroid carcinoma.

    Science.gov (United States)

    Gonzalo, Irene T Gaw; Itti, Emmanuel; Mlikotic, Anton; Pham, Le H; Cesar, Romeo B; Meignan, Michel; Mishkin, Fred S

    2003-01-01

    To evaluate the feasibility of using [(18)F]fluorodeoxyglucose ((18)FDG) triple-head coincidence imaging as a potential cost-effective alternative to positron emission tomography in the setting of suspected recurrence of papillary thyroid carcinoma. We retrospectively studied 10 patients with suspected recurrence of papillary carcinoma of the thyroid, who underwent (18)FDG coincidence imaging,(131)I scanning, and a reference anatomic scan (computed tomography, magnetic resonance imaging, or both) within 1 year in most cases. The (131)I scan detected the recurrence in five patients (62.5%) and failed to reveal recurrent cancer in three patients (37.5%); in contrast,(18)FDG imaging detected the recurrence in eight patients (100%) and was true negative in two patients in whom the scans were performed more than 1 year after effective therapy for the recurrence. The sensitivity of detection was unrelated to lesion size. The (18)FDG imaging results led to additional radiotherapy in all (131)I-negative patients, two of whom had high thyroglobulin levels and one of whom had a low thyroglobulin concentration but the presence of antithy-roglobulin antibodies. We conclude that (18)FDG triple-head coincidence imaging is useful for routine management of patients with thyroid cancer who have no abnormalities detected on (131)I scans but have high serum thyroglobulin levels. This technique, however, may not be as sensitive as a dedicated positron emission tomographic device, particularly for the assessment of small tumors.

  8. A quantitative damage imaging technique based on enhanced CCRTM for composite plates using 2D scan

    Science.gov (United States)

    He, Jiaze; Yuan, Fuh-Gwo

    2016-10-01

    A two-dimensional (2D) non-contact areal scan system was developed to image and quantify impact damage in a composite plate using an enhanced zero-lag cross-correlation reverse-time migration (E-CCRTM) technique. The system comprises a single piezoelectric wafer mounted on the composite plate and a laser Doppler vibrometer (LDV) for scanning a region in the vicinity of the PZT to capture the scattered wavefield. The proposed damage imaging technique takes into account the amplitude, phase, geometric spreading, and all of the frequency content of the Lamb waves propagating in the plate; thus, a reflectivity coefficients of the delamination is calculated and potentially related to damage severity. Comparisons are made in terms of damage imaging quality between 2D areal scans and 1D line scans as well as between the proposed and existing imaging conditions. The experimental results show that the 2D E-CCRTM performs robustly when imaging and quantifying impact damage in large-scale composites using a single PZT actuator with a nearby areal scan using LDV.

  9. Automated detection of analyzable metaphase chromosome cells depicted on scanned digital microscopic images

    Science.gov (United States)

    Qiu, Yuchen; Wang, Xingwei; Chen, Xiaodong; Li, Yuhua; Liu, Hong; Li, Shibo; Zheng, Bin

    2010-02-01

    Visually searching for analyzable metaphase chromosome cells under microscopes is quite time-consuming and difficult. To improve detection efficiency, consistency, and diagnostic accuracy, an automated microscopic image scanning system was developed and tested to directly acquire digital images with sufficient spatial resolution for clinical diagnosis. A computer-aided detection (CAD) scheme was also developed and integrated into the image scanning system to search for and detect the regions of interest (ROI) that contain analyzable metaphase chromosome cells in the large volume of scanned images acquired from one specimen. Thus, the cytogeneticists only need to observe and interpret the limited number of ROIs. In this study, the high-resolution microscopic image scanning and CAD performance was investigated and evaluated using nine sets of images scanned from either bone marrow (three) or blood (six) specimens for diagnosis of leukemia. The automated CAD-selection results were compared with the visual selection. In the experiment, the cytogeneticists first visually searched for the analyzable metaphase chromosome cells from specimens under microscopes. The specimens were also automated scanned and followed by applying the CAD scheme to detect and save ROIs containing analyzable cells while deleting the others. The automated selected ROIs were then examined by a panel of three cytogeneticists. From the scanned images, CAD selected more analyzable cells than initially visual examinations of the cytogeneticists in both blood and bone marrow specimens. In general, CAD had higher performance in analyzing blood specimens. Even in three bone marrow specimens, CAD selected 50, 22, 9 ROIs, respectively. Except matching with the initially visual selection of 9, 7, and 5 analyzable cells in these three specimens, the cytogeneticists also selected 41, 15 and 4 new analyzable cells, which were missed in initially visual searching. This experiment showed the feasibility of

  10. Sweep devices for picosecond image-converter streak cameras

    International Nuclear Information System (INIS)

    Cunin, B.; Miehe, J.A.; Sipp, B.; Schelev, M.Ya.; Serduchenko, J.N.; Thebault, J.

    1979-01-01

    Four different sweep devices based on microwave tubes, avalanche transistors, krytrons, and laser-triggered spark gaps are treated in detail. These control circuits are developed for picosecond image-converter cameras and generate sweep pulses providing streak speeds in the range of 10 7 to 5x10 10 cm/sec with maximum time resolution better than 10 -12 sec. Special low-jitter triggering schemes reduce the jitter to less than 5x10 -11 sec. Some problems arising in the construction and matching of the sweep devices and image-streak tube are discussed. Comparative parameters of nanosecond switching elements are presented. The results described can be used by other authors involved in streak camera development

  11. Device for congruent X-ray images of teeth

    International Nuclear Information System (INIS)

    Wegner, H.; Zeumer, H.

    1987-01-01

    This invention has to do with a device for congruent X-ray images of teeth by means of the long-tube parallel technique and the long-tube semi-angle technique. The aim is to have no disturbing lever forces in order to avoid mechanical tensions between patient and X-ray tube assembly and to achieve a true projection of teeth and jaw-bone part also under unfavourable anatomical conditions

  12. Novel low-dose imaging technique for characterizing atomic structures through scanning transmission electron microscope

    Science.gov (United States)

    Su, Chia-Ping; Syu, Wei-Jhe; Hsiao, Chien-Nan; Lai, Ping-Shan; Chen, Chien-Chun

    2017-08-01

    To investigate dislocations or heterostructures across interfaces is now of great interest to condensed matter and materials scientists. With the advances in aberration-corrected electron optics, the scanning transmission electron microscope has demonstrated its excellent capability of characterizing atomic structures within nanomaterials, and well-resolved atomic-resolution images can be obtained through long-exposure data acquisition. However, the sample drifting, carbon contamination, and radiation damage hinder further analysis, such as deriving three-dimensional (3D) structures from a series of images. In this study, a method for obtaining atomic-resolution images with significantly reduced exposure time was developed, using which an original high-resolution image with approximately one tenth the electron dose can be obtained by combining a fast-scan high-magnification image and a slow-scan low-magnification image. The feasibility of obtaining 3D atomic structures using the proposed approach was demonstrated through multislice simulation. Finally, the feasibility and accuracy of image restoration were experimentally verified. This general method cannot only apply to electron microscopy but also benefit to image radiation-sensitive materials using various light sources.

  13. Real-Time Imaging with Frequency Scanning Array Antenna for Industrial Inspection Applications at W band

    Science.gov (United States)

    Larumbe, Belen; Laviada, Jaime; Ibáñez-Loinaz, Asier; Teniente, Jorge

    2018-01-01

    A real-time imaging system based on a frequency scanning antenna for conveyor belt setups is presented in this paper. The frequency scanning antenna together with an inexpensive parabolic reflector operates at the W band enabling the detection of details with dimensions in the order of 2 mm. In addition, a low level of sidelobes is achieved by optimizing unequal dividers to window the power distribution for sidelobe reduction. Furthermore, the quality of the images is enhanced by the radiation pattern properties. The performance of the system is validated by showing simulation as well as experimental results obtained in real time, proving the feasibility of these kinds of frequency scanning antennas for cost-effective imaging applications.

  14. A multiphoton laser scanning microscope setup for transcranial in vivo brain imaging on mice

    Science.gov (United States)

    Nase, Gabriele; Helm, P. Johannes; Reppen, Trond; Ottersen, Ole Petter

    2005-12-01

    We describe a multiphoton laser scanning microscope setup for transcranial in vivo brain imaging in mice. The modular system is based on a modified industrial standard Confocal Scanning Laser Microscope (CSLM) and is assembled mainly from commercially available components. A special multifunctional stage, which is optimized for both laser scanning microscopic observation and preparative animal surgery, has been developed and built. The detection unit includes a highly efficient photomultiplier tube installed in a Peltier-cooled thermal box shielding the detector from changes in room temperature and from distortions caused by external electromagnetic fields. The images are recorded using a 12-bit analog-to-digital converter. Depending on the characteristics of the staining, individual nerve cells can be imaged down to at least 100μm below the intact cranium and down to at least 200μm below the opened cranium.

  15. Increased Sensitivity to Pathological Brain Changes Using Co-registration of Magnetic Resonance Imaging Scans

    Energy Technology Data Exchange (ETDEWEB)

    Burdett, J.; Stevens, J.; Flugel, D.; Williams, E.; Duncan, J.S.; Lemieux, L. [National Society for Epilepsy, Chalfont St Peter (United Kingdom). The MRI Unit

    2006-12-15

    Purpose: To compare automatic software-based co-registration of serial magnetic resonance imaging (MRI) scans with conventional visual comparison, by expert neuroradiologists.Material and Methods: Sixty-four patients who were referred to our epilepsy MRI unit for cerebral imaging were identified as having potentially, non- or slow-growing lesions or cerebral atrophy and followed with sequential scans over a period of up to 8 years, resulting in a total of 92 pairs of scans. Scans were categorized as showing either lesions or atrophy. Each pair of scans was reviewed twice for the presence of change, with and without co-registration, performed using automated software. Results: Co-registration and visual reporting without co-registration were discordant in the lesions group in nine out of 69 datasets (13%), and in 16 out of 23 pairs of scans in the atrophy group (69%). The most common cause of discordance was visual reporting not detecting changes apparent by co-registration. In three cases, changes detected visually were not detected following co-registration. Conclusion: In the group of patients studied, co-registration was more sensitive for detecting changes than visual comparison, particularly with respect to atrophic changes of the brain. With the increasing availability of sophisticated independent consoles attached to MRI scanners that may be used for image co-registration, we propose that serial T1-weighted volumetric MRI brain co-registration should be considered for integration into routine clinical practice to assess patients with suspected progressive disease.

  16. Increased Sensitivity to Pathological Brain Changes Using Co-registration of Magnetic Resonance Imaging Scans

    International Nuclear Information System (INIS)

    Burdett, J.; Stevens, J.; Flugel, D.; Williams, E.; Duncan, J.S.; Lemieux, L.

    2006-01-01

    Purpose: To compare automatic software-based co-registration of serial magnetic resonance imaging (MRI) scans with conventional visual comparison, by expert neuroradiologists.Material and Methods: Sixty-four patients who were referred to our epilepsy MRI unit for cerebral imaging were identified as having potentially, non- or slow-growing lesions or cerebral atrophy and followed with sequential scans over a period of up to 8 years, resulting in a total of 92 pairs of scans. Scans were categorized as showing either lesions or atrophy. Each pair of scans was reviewed twice for the presence of change, with and without co-registration, performed using automated software. Results: Co-registration and visual reporting without co-registration were discordant in the lesions group in nine out of 69 datasets (13%), and in 16 out of 23 pairs of scans in the atrophy group (69%). The most common cause of discordance was visual reporting not detecting changes apparent by co-registration. In three cases, changes detected visually were not detected following co-registration. Conclusion: In the group of patients studied, co-registration was more sensitive for detecting changes than visual comparison, particularly with respect to atrophic changes of the brain. With the increasing availability of sophisticated independent consoles attached to MRI scanners that may be used for image co-registration, we propose that serial T1-weighted volumetric MRI brain co-registration should be considered for integration into routine clinical practice to assess patients with suspected progressive disease

  17. Sparse sampling and reconstruction for electron and scanning probe microscope imaging

    Science.gov (United States)

    Anderson, Hyrum; Helms, Jovana; Wheeler, Jason W.; Larson, Kurt W.; Rohrer, Brandon R.

    2015-07-28

    Systems and methods for conducting electron or scanning probe microscopy are provided herein. In a general embodiment, the systems and methods for conducting electron or scanning probe microscopy with an undersampled data set include: driving an electron beam or probe to scan across a sample and visit a subset of pixel locations of the sample that are randomly or pseudo-randomly designated; determining actual pixel locations on the sample that are visited by the electron beam or probe; and processing data collected by detectors from the visits of the electron beam or probe at the actual pixel locations and recovering a reconstructed image of the sample.

  18. Fabrication of wear-resistant silicon microprobe tips for high-speed surface roughness scanning devices

    Science.gov (United States)

    Wasisto, Hutomo Suryo; Yu, Feng; Doering, Lutz; Völlmeke, Stefan; Brand, Uwe; Bakin, Andrey; Waag, Andreas; Peiner, Erwin

    2015-05-01

    Silicon microprobe tips are fabricated and integrated with piezoresistive cantilever sensors for high-speed surface roughness scanning systems. The fabrication steps of the high-aspect-ratio silicon microprobe tips were started with photolithography and wet etching of potassium hydroxide (KOH) resulting in crystal-dependent micropyramids. Subsequently, thin conformal wear-resistant layer coating of aluminum oxide (Al2O3) was demonstrated on the backside of the piezoresistive cantilever free end using atomic layer deposition (ALD) method in a binary reaction sequence with a low thermal process and precursors of trimethyl aluminum and water. The deposited Al2O3 layer had a thickness of 14 nm. The captured atomic force microscopy (AFM) image exhibits a root mean square deviation of 0.65 nm confirming the deposited Al2O3 surface quality. Furthermore, vacuum-evaporated 30-nm/200-nm-thick Au/Cr layers were patterned by lift-off and served as an etch mask for Al2O3 wet etching and in ICP cryogenic dry etching. By using SF6/O2 plasma during inductively coupled plasma (ICP) cryogenic dry etching, micropillar tips were obtained. From the preliminary friction and wear data, the developed silicon cantilever sensor has been successfully used in 100 fast measurements of 5- mm-long standard artifact surface with a speed of 15 mm/s and forces of 60-100 μN. Moreover, the results yielded by the fabricated silicon cantilever sensor are in very good agreement with those of calibrated profilometer. These tactile sensors are targeted for use in high-aspect-ratio microform metrology.

  19. Reducing task-based fMRI scanning time using simultaneous multislice echo planar imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kiss, Mate [Hungarian Academy of Sciences, Brain Imaging Centre, Research Centre for Natural Sciences, Budapest (Hungary); Janos Szentagothai PhD School, MR Research Centre, Budapest (Hungary); National Institute of Clinical Neuroscience, Department of Neuroradiology, Budapest (Hungary); Hermann, Petra; Vidnyanszky, Zoltan; Gal, Viktor [Hungarian Academy of Sciences, Brain Imaging Centre, Research Centre for Natural Sciences, Budapest (Hungary)

    2018-03-15

    To maintain alertness and to remain motionless during scanning represent a substantial challenge for patients/subjects involved in both clinical and research functional magnetic resonance imaging (fMRI) examinations. Therefore, availability and application of new data acquisition protocols allowing the shortening of scan time without compromising the data quality and statistical power are of major importance. Higher order category-selective visual cortical areas were identified individually, and rapid event-related fMRI design was used to compare three different sampling rates (TR = 2000, 1000, and 410 ms, using state-of-the-art simultaneous multislice imaging) and four different scanning lengths to match the statistical power of the traditional scanning methods to high sampling-rate design. The results revealed that ∝ 4 min of the scan time with 1 Hz (TR = 1000 ms) sampling rate and ∝ 2 min scanning at ∝ 2.5 Hz (TR = 410 ms) sampling rate provide similar localization sensitivity and selectivity to that obtained with 11-min session at conventional, 0.5 Hz (TR = 2000 ms) sampling rate. Our findings suggest that task-based fMRI examination of clinical population prone to distress such as presurgical mapping experiments might substantially benefit from the reduced (20-40%) scanning time that can be achieved by the application of simultaneous multislice sequences. (orig.)

  20. 75 FR 70290 - In the Matter of Certain Biometric Scanning Devices, Components Thereof, Associated Software, and...

    Science.gov (United States)

    2010-11-17

    ... INTERNATIONAL TRADE COMMISSION [Inv. No. 337-TA-720] In the Matter of Certain Biometric Scanning... Tariff Act of 1930, 19 U.S.C. 1337, based on a complaint filed by Cross Match Technologies, Inc. of Palm... for importation, and sale within the United States after importation of certain biometric scanning...

  1. Usefulness of 3D-image of ossicles with helical scanning

    International Nuclear Information System (INIS)

    Makihata, Hiroshi; Kimura, Hideaki; Hanaguri, Katsurou; Fukushima, Noriyuki; Oda, Yukari

    1995-01-01

    It is important to understand the abnormalities of ossicles (continuity, destruction and malformation) in clinical practice of middle ear diseases. Multidirection exposures were needed to visualize ossicles with the conventional CT scanning, because they are visualized in 2D images. It was difficult to make patients hold the posture and to settle the problems such as an increase in X-ray dose. We created 3D images of ossicles with a helical scanning, and examined the visualization of the normal and abnormal ear (otitis media cholesteatoma) especially in terms of continuity in each of 20 patients. We would here like to report the favorable results together with some literature review. (author)

  2. Evaluation of /sup 201/TlCl and delayed scan for thyroid imaging agent

    Energy Technology Data Exchange (ETDEWEB)

    Taniguchi, Tatsuyoshi; Harada, Taneichi; Takahashi, Tatsuo; Senoo, Tsuneaki; Ohtsuka, Nobuaki; Ito, Yasuhiko [Kawasaki Medical School, Kurashiki, Okayama (Japan)

    1982-11-01

    The results of 189 patients with nodular goiter by imaging with /sup 201/TlCl following with sup(99m)TcO/sub 4//sup -/ was presented. Accumulation of /sup 201/TlCl to the corresponding area was observed in 85.5% of cancer, 62.2% of adenoma, 42.5% of adenomatous goiter, and the usefulness of /sup 201/TlCl (early scan) for thyroid imaging agent was recognized. On the other hand, delayed scan for purpose of differentiation from benign to malignant was also performed. However, no significant differences were obtained.

  3. Study of the detective quantum efficiency for the kinestatic charge detector as a megavoltage imaging device

    Science.gov (United States)

    Samant, Sanjiv S.; Gopal, Arun; DiBianca, Frank A.

    2003-06-01

    Megavoltage x-ray imaging suffers from relatively poor contrast and spatial resolution compared to diagnostic kilovoltage x-ray imaging due to the dominant Compton scattering in the former. Recently available amorphous silicon/selenium based flat-panel imagers overcome many of the limitations of poor contrast and spatial resolution that affect conventional video based electronic portal imaging devices (EPIDs). An alternative technology is presented here: kinestatic charge detection (KCD). The KCD uses a slot photon beam, high-pressure gas (xenon, 100 atm) and a multi-ion rectangular chamber in scanning mode. An electric field is used to regulate the cation drift velocity. By matching the scanning speed with that of the cation drift, the cations remain static in the object frame of reference, allowing temporal integration of the signal. KCD imaging is characterized by reduced scatter and a high signal-to-noise ratio. Measurements and Monte Carlo simulations of modulation transfer function (MTF), noise power spectrum (NPS) and the detective quantum efficiency (DQE) of a prototype small field of view KCD detector (384 channels, 0.5 mm spacing) were carried out. Measurements yield DQE[0]=0.19 and DQE[0.5cy/mm]=0.01. KCD imaging is compared to film and commercial EPID systems using phantoms, with the KCD requiring an extremely low dose (0.1 cGy) per image. A proposed cylindrical chamber design with a higher ion-collection depth is expected to further improve image quality (DQE[0]>0.25).

  4. Automatic prostate localization on cone-beam CT scans for high precision image-guided radiotherapy

    International Nuclear Information System (INIS)

    Smitsmans, Monique H.P.; Bois, Josien de; Sonke, Jan-Jakob; Betgen, Anja; Zijp, Lambert J.; Jaffray, David A.; Lebesque, Joos V.; Herk, Marcel van

    2005-01-01

    Purpose: Previously, we developed an automatic three-dimensional gray-value registration (GR) method for fast prostate localization that could be used during online or offline image-guided radiotherapy. The method was tested on conventional computed tomography (CT) scans. In this study, the performance of the algorithm to localize the prostate on cone-beam CT (CBCT) scans acquired on the treatment machine was evaluated. Methods and Materials: Five to 17 CBCT scans of 32 prostate cancer patients (332 scans in total) were used. For 18 patients (190 CBCT scans), the CBCT scans were acquired with a collimated field of view (FOV) (craniocaudal). This procedure improved the image quality considerably. The prostate (i.e., prostate plus seminal vesicles) in each CBCT scan was registered to the prostate in the planning CT scan by automatic 3D gray-value registration (normal GR) starting from a registration on the bony anatomy. When these failed, registrations were repeated with a fixed rotation point locked at the prostate apex (fixed apex GR). Registrations were visually assessed in 3D by one observer with the help of an expansion (by 3.6 mm) of the delineated prostate contours of the planning CT scan. The percentage of successfully registered cases was determined from the combined normal and fixed apex GR assessment results. The error in gray-value registration for both registration methods was determined from the position of one clearly defined calcification in the prostate gland (9 patients, 71 successful registrations). Results: The percentage of successfully registered CBCT scans that were acquired with a collimated FOV was about 10% higher than for CBCT scans that were acquired with an uncollimated FOV. For CBCT scans that were acquired with a collimated FOV, the percentage of successfully registered cases improved from 65%, when only normal GR was applied, to 83% when the results of normal and fixed apex GR were combined. Gray-value registration mainly failed (or

  5. Excitation-scanning hyperspectral imaging system for microscopic and endoscopic applications

    Science.gov (United States)

    Mayes, Sam A.; Leavesley, Silas J.; Rich, Thomas C.

    2016-04-01

    Current microscopic and endoscopic technologies for cancer screening utilize white-light illumination sources. Hyper-spectral imaging has been shown to improve sensitivity while retaining specificity when compared to white-light imaging in both microscopy and in vivo imaging. However, hyperspectral imaging methods have historically suffered from slow acquisition times due to the narrow bandwidth of spectral filters. Often minutes are required to gather a full image stack. We have developed a novel approach called excitation-scanning hyperspectral imaging that provides 2-3 orders of magnitude increased signal strength. This reduces acquisition times significantly, allowing for live video acquisition. Here, we describe a preliminary prototype excitation-scanning hyperspectral imaging system that can be coupled with endoscopes or microscopes for hyperspectral imaging of tissues and cells. Our system is comprised of three subsystems: illumination, transmission, and imaging. The illumination subsystem employs light-emitting diode arrays to illuminate at different wavelengths. The transmission subsystem utilizes a unique geometry of optics and a liquid light guide. Software controls allow us to interface with and control the subsystems and components. Digital and analog signals are used to coordinate wavelength intensity, cycling and camera triggering. Testing of the system shows it can cycle 16 wavelengths at as fast as 1 ms per cycle. Additionally, more than 18% of the light transmits through the system. Our setup should allow for hyperspectral imaging of tissue and cells in real time.

  6. Scanning technology selection impacts acceptability and usefulness of image-rich content

    Directory of Open Access Journals (Sweden)

    Kristine M. Alpi

    2016-01-01

    Full Text Available Objective: Clinical and research usefulness of articles can depend on image quality. This study addressed whether scans of figures in black and white (B&W, grayscale, or color, or portable document format (PDF to tagged image file format (TIFF conversions as provided by interlibrary loan or document delivery were viewed as acceptable or useful by radiologists or pathologists. Methods: Residency coordinators selected eighteen figures from studies from radiology, clinical pathology, and anatomic pathology journals.With original PDF controls, each figure was prepared in three or four experimental conditions: PDF conversion to TIFF, and scans from print in B&W, grayscale, and color. Twelve independent observers indicated whether they could identify the features and whether the image quality was acceptable. They also ranked all the experimental conditions of each figure in terms of usefulness. Results: Of 982 assessments of 87 anatomic pathology, 83 clinical pathology, and 77 radiology images, 471 (48% were unidentifiable. Unidentifiability of originals (4% and conversions (10% was low. For scans, unidentifiability ranged from 53% for color, to 74% for grayscale, to 97% for B&W. Of 987 responses about acceptability (n¼405, 41% were said to be unacceptable, 97% of B&W, 66% of grayscale, 41% of color, and 1% of conversions. Hypothesized order (original, conversion, color, grayscale, B&W matched 67% of rankings (n¼215. Conclusions: PDF to TIFF conversion provided acceptable content. Color images are rarely useful in grayscale (12% or B&W (less than 1%. Acceptability of grayscale scans of noncolor originals was 52%. Digital originals are needed for most images. Print images in color or grayscale should be scanned using those modalities.

  7. Cine viability magnetic resonance imaging of the heart without increased scan time.

    Science.gov (United States)

    Hassanein, Azza S; Khalifa, Ayman M; Ibrahim, El-Sayed H

    2016-02-01

    Cardiac magnetic resonance imaging (MRI) provides information about myocardial morphology, function, and viability from cine, tagged, and late gadolinium enhancement (LGE) images, respectively. While the cine and tagged images are acquired in a time-resolved fashion, the LGE images are acquired at a single timeframe. The purpose of this work is to develop a method for generating cine LGE images without additional scan time. The motion field is extracted from the tagged images, and is then used to guide the deformation of the infarcted region from the acquired LGE image at the acquired timeframe to any other timeframe. Major techniques for motion estimation, including harmonic phase (HARP) and optical flow analysis, are tested in this work for motion estimation. The proposed method is tested on numerical phantom and images from four human subjects. The generated cine LGE images showed both viability and wall motion information in the same set of images without additional scan time or image misregistration problems. The band-pass optical flow analysis resulted in the most accurate motion estimation compared to other methods, especially HARP, which fails to track points at the myocardial boundary. Infarct transmurality from the generated images showed good agreement with myocardial strain, and wall thickening showed good agreement with that measured from conventional cine images. In conclusion, the developed technique allows for generating cine LGE images that enable simultaneous display of wall motion and viability information. The generated images could be useful for estimating myocardial contractility reserve and for treatment prognosis. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Superresolution upgrade for confocal spinning disk systems using image scanning microscopy (Conference Presentation)

    Science.gov (United States)

    Isbaner, Sebastian; Hähnel, Dirk; Gregor, Ingo; Enderlein, Jörg

    2017-02-01

    Confocal Spinning Disk Systems are widely used for 3D cell imaging because they offer the advantage of optical sectioning at high framerates and are easy to use. However, as in confocal microscopy, the imaging resolution is diffraction limited, which can be theoretically improved by a factor of 2 using the principle of Image Scanning Microscopy (ISM) [1]. ISM with a Confocal Spinning Disk setup (CSDISM) has been shown to improve contrast as well as lateral resolution (FWHM) from 201 +/- 20 nm to 130 +/- 10 nm at 488 nm excitation. A minimum total acquisition time of one second per ISM image makes this method highly suitable for 3D live cell imaging [2]. Here, we present a multicolor implementation of CSDISM for the popular Micro-Manager Open Source Microscopy platform. Since changes in the optical path are not necessary, this will allow any researcher to easily upgrade their standard Confocal Spinning Disk system at remarkable low cost ( 5000 USD) with an ISM superresolution option. [1]. Müller, C.B. and Enderlein, J. Image Scanning Microscopy. Physical Review Letters 104, (2010). [2]. Schulz, O. et al. Resolution doubling in fluorescence microscopy with confocal spinning-disk image scanning microscopy. Proceedings of the National Academy of Sciences of the United States of America 110, 21000-5 (2013).

  9. Evaluation of the image quality of chest CT scans: a phantom study

    Energy Technology Data Exchange (ETDEWEB)

    Martins N, P. I.; Prata M, A., E-mail: priscillainglid@gmail.com [Centro Federal de Educacao Tecnologica de Minas Gerais, Centro de Engenharia Biomedica, Av. Amazonas 5253, 30421-169 Nova Suica, Belo Horizonte, Minas Gerais (Brazil)

    2016-10-15

    Computed tomography (CT) is considered one of the most important methods of medical imaging employed nowadays, due to its non-invasiveness and the high quality of the images it is able to generate. However, the diagnostic radiation dose received by an individual over the year often exceeds the dose received on account of background radiation. Therefore, it is important to know and to control the dose distribution in the patient by varying the image acquisition parameters. The aim of this study is to evaluate the variation of the image quality of chest CT scans performed by two phantoms. In this paper, a cylindrical Polymethyl Methacrylate (PMMA) chest phantom was used and a second PMMA phantom has been developed with the same volume but an oblong shape, based on the actual dimensions of a male human thorax, in the axillary region. Ten-centimeter scans of the central area of each phantom were performed by a 16-channel Toshiba CT scanner, model Alexion. The scanning protocol employed was the radiology service protocol for chest scans. The noise survey was conducted within the image of the center slice, in five regions: one central and four peripheral areas close to the edge of the object (anterior, posterior, left and right). The recorded values showed that the oblong phantom, with a shape that is more similar to the actual human chest, has a considerably smaller noise, especially in the anterior, posterior and central regions. (Author)

  10. Evaluation of the image quality of chest CT scans: a phantom study

    International Nuclear Information System (INIS)

    Martins N, P. I.; Prata M, A.

    2016-10-01

    Computed tomography (CT) is considered one of the most important methods of medical imaging employed nowadays, due to its non-invasiveness and the high quality of the images it is able to generate. However, the diagnostic radiation dose received by an individual over the year often exceeds the dose received on account of background radiation. Therefore, it is important to know and to control the dose distribution in the patient by varying the image acquisition parameters. The aim of this study is to evaluate the variation of the image quality of chest CT scans performed by two phantoms. In this paper, a cylindrical Polymethyl Methacrylate (PMMA) chest phantom was used and a second PMMA phantom has been developed with the same volume but an oblong shape, based on the actual dimensions of a male human thorax, in the axillary region. Ten-centimeter scans of the central area of each phantom were performed by a 16-channel Toshiba CT scanner, model Alexion. The scanning protocol employed was the radiology service protocol for chest scans. The noise survey was conducted within the image of the center slice, in five regions: one central and four peripheral areas close to the edge of the object (anterior, posterior, left and right). The recorded values showed that the oblong phantom, with a shape that is more similar to the actual human chest, has a considerably smaller noise, especially in the anterior, posterior and central regions. (Author)

  11. Methodology for converting CT medical images to MCNP input using the Scan2MCNP system

    International Nuclear Information System (INIS)

    Boia, L.S.; Silva, A.X.; Cardoso, S.C.; Castro, R.C.

    2009-01-01

    This paper develops a methodology for the application software Scan2MCNP, which converts medical images DICOM (Digital Imaging and Communications in Medicine) for MCNP input file. The Scan2MCNP handles, processes and executes the medical images generated by CT equipment, allowing the user to perform the selection and parameterization of the study area in question (tissues and organs). The details of these worked in medical imaging software, therefore, will be converted to equity to the process of language analysis of MCNP radiation transport, through the generation of a code input file. With this file, it is possible to simulate any situation/problem of the type and level of radiation to the proposed treatment chosen by the medical staff responsible for the patient. Within a computational process oriented, the Scan2MCNP can contribute along with other software that has been used recently in the area of medical physics, to improve the levels of quality and precision of radiotherapy treatments. In this work, medical images DICOM of the Anthropomorphic Rando Phantom were used in the process of analysis and development of computer software Scan2MCNP. However, it emphasized that the software is successful in certain situations, depending upon a number of auxiliary procedures and software that can help in the solution of certain problems in the natural radiation treatment or express agility by the team of medical physics. (author)

  12. Nuclear Scans

    Science.gov (United States)

    Nuclear scans use radioactive substances to see structures and functions inside your body. They use a special ... images. Most scans take 20 to 45 minutes. Nuclear scans can help doctors diagnose many conditions, including ...

  13. An electronic probe micro-analyser. A linear scan device; Microanalyseur a sonde electronique. Dispositif de balayage lineaire

    Energy Technology Data Exchange (ETDEWEB)

    Kirianenko, A; Maurice, F [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1963-07-01

    The Castaing electronic probe micro-analyser makes possible static analysis at successive points. For two years this apparatus has been equipped by its constructor with an automatic device for surface scanning. In order to increase the micro-analyser's efficiency a 'linear' scan device has been incorporated making it possible to obtain semi-quantitative analyses very rapidly. (authors) [French] Le microanalyseur a sonde electronique de Castaing permet l'analyse statique en des points successifs. Depuis deux ans, cet appareil a ete equipe par son constructeur d'un dispositif de balayage automatique 'surface'. Afin d'augmenter l'efficacite du microanalyaeur, on a adapte un dispositif de balayage 'lineaire' qui permet d'obtenir tres rapidement des analyses semi-quantitative. (auteurs)

  14. Dental-CT: image quality and absorbed radiation dose of different scan protocols

    International Nuclear Information System (INIS)

    Schorn, C.; Alamo, L.; Funke, M.; Grabbe, E.; Visser, H.; Hermann, K.P.

    1999-01-01

    Purpose: To develop a scan protocol for dental-CT which guarantees good image quality at the lowest possible radiation dose. Methods: In an experimental investigation Dental-CT (HSA, GE, Milwaukee, USA) of the mandible of two human skeletons positioned in a water tank were performed in order to define the most advantageous scan protocol. Tube currents ranged from 40 to 200 mA and the scan technique was modified (axial mode or helical mode with pitches of 1 to 3 and corresponding increments of 0.4 to 1.0 mm). 39 patients underwent a dental-CT with decreased current (80 mA) in the helical scan mode (pitch 2, slice thickness 1 mm). Dose measurements were performed for two different scan protocols (A: axial, 130 mAs, B: helical, 80 mA, pitch 2). Results: The preliminary investigations of image quality showed only a minor effect of the applied current. For the helical scan mode, pitches of more than 2 impaired image quality. A low increment had no advantages. There were no disadvantages in clinical practice using protocol B with decreased tube current. Absorbed radiation dose of dental CT performed with protocol B was decreased to one third in comparison to protocol A. Conclusions: A scan protocol with a low tube current (e.g., 80 mA, for a rotation time of 1 s) and a helical scan mode (e.g., for a slice thickness of 1 mm with a pitch of 2 and an increment of 1 mm) is recommended for performing dental-CT. (orig.) [de

  15. Validation of a new imaging device for telemedical ulcer monitoring

    DEFF Research Database (Denmark)

    Rasmussen, Benjamin Schnack; Frøkjær, Johnny; Bisgaard Jørgensen, Line

    2015-01-01

    between the new portable camera and the iPhone images vs. clinical assessment as the 'gold standard'. The study included 36 foot ulcers. Four specialists rated the ulcers and filled out a questionnaire, which formed the basis of the evaluation. RESULTS: We found fair to very good intra-rater agreement...... for the new PID and iPhone, respectively. The gold standard was evaluated by assessing the ulcer twice by two different specialists. Kappa values were moderate to very good with respect to inter-rater agreement except for two variables. The agreement between standard and new equipment compared to the gold......PURPOSE: To clarify whether a new portable imaging device (PID) providing 3D images for telemedical use constitutes a more correct expression of the clinical situation compared to standard telemedical equipment in this case iPhone 4s. METHOD: We investigated intra- and interindividual variability...

  16. Design of a cathodoluminescence image generator using a Raspberry Pi coupled to a scanning electron microscope

    Science.gov (United States)

    Benítez, Alfredo; Santiago, Ulises; Sanchez, John E.; Ponce, Arturo

    2018-01-01

    In this work, an innovative cathodoluminescence (CL) system is coupled to a scanning electron microscope and synchronized with a Raspberry Pi computer integrated with an innovative processing signal. The post-processing signal is based on a Python algorithm that correlates the CL and secondary electron (SE) images with a precise dwell time correction. For CL imaging, the emission signal is collected through an optical fiber and transduced to an electrical signal via a photomultiplier tube (PMT). CL Images are registered in a panchromatic mode and can be filtered using a monochromator connected between the optical fiber and the PMT to produce monochromatic CL images. The designed system has been employed to study ZnO samples prepared by electrical arc discharge and microwave methods. CL images are compared with SE images and chemical elemental mapping images to correlate the emission regions of the sample.

  17. Use of multimedia messaging system (MMS) by junior doctors for scan image transmission in neurosurgery.

    Science.gov (United States)

    Ling, Ji Min; Lim, Kim Zhuan; Ng, Wai Hoe

    2012-02-01

    Multimedia Messaging Service (MMS) is used by neurosurgical residents to transmit scan images to the attending neurosurgeon in conjunction with telephone consultation. This service has been well received by the attending neurosurgeons, who felt that after viewing scan images on their phones, they felt increased confidence in clinical decision making and that it reduced the need for recall to the hospital. The use of MMS can be extended to junior doctors making referrals from regional hospitals with no neurosurgical cover. This study aims to validate the competency of non-neurosurgically trained junior doctors in selecting optimal images to transmit via MMS to the attending neurosurgeon on call. Ten junior doctors with no formal neurosurgical training and five neurosurgical residents were interviewed. They were shown the full complement of images together with relevant clinical history and assessment. They were then asked to make the radiological diagnosis and then select two images for MMS transmission to the attending neurosurgeon that they thought would best aid the neurosurgeon in clinical decision making. The attending neurosurgeon was asked to comment, on each image, whether his management plan would differ if he was shown the entire series of the images. All the images chosen are deemed appropriate, and the decision made based on the MMS images would be similar if the entire series of images were available to the neurosurgeon. However, 7 of 10 junior doctors were unable to read magnetic resonance images of lumbar spine. There was no significant difference in the images chosen by the neurosurgical residents and the junior doctors. It is feasible and safe for junior doctors to utilize MMS to transmit computed tomographic images to a neurosurgeon while making an urgent referral. The images selected are representative of the disease pathology and facilitate clinical decision making. Copyright © 2012 Elsevier Inc. All rights reserved.

  18. Lumbar spine joint synovial cysts of intraspinal development. CT scan imaging

    Energy Technology Data Exchange (ETDEWEB)

    Vallee, C.; Chevrot, A.; Benhamouda, M. and others

    CT scan imaging findings are described in 22 patients with lumbar spine joint synovial cysts, of intraspinal development, provoking sciatica or lumbosciatica from nerve compression in spinal canal. Diagnosis was suggested by a mass at the posterior joint level, of variable density, sometimes with peripheral calcification, presenting a vacuum appearance on occasions, and with enhanced image with contrast. Differential diagnosis is from excluded hernia and postoperative fibrosis. Posterior intra-articular arthrography can confirm diagnosis and allow treatment with prolonged action corticoid infiltrations.

  19. Adaptive optics scanning laser ophthalmoscopy in fundus imaging, a review and update

    OpenAIRE

    Zhang, Bing; Li, Ni; Kang, Jie; He, Yi; Chen, Xiao-Ming

    2017-01-01

    Adaptive optics scanning laser ophthalmoscopy (AO-SLO) has been a promising technique in funds imaging with growing popularity. This review firstly gives a brief history of adaptive optics (AO) and AO-SLO. Then it compares AO-SLO with conventional imaging methods (fundus fluorescein angiography, fundus autofluorescence, indocyanine green angiography and optical coherence tomography) and other AO techniques (adaptive optics flood-illumination ophthalmoscopy and adaptive optics optical coherenc...

  20. Excitation-scanning hyperspectral imaging as a means to discriminate various tissues types

    Science.gov (United States)

    Deal, Joshua; Favreau, Peter F.; Lopez, Carmen; Lall, Malvika; Weber, David S.; Rich, Thomas C.; Leavesley, Silas J.

    2017-02-01

    Little is currently known about the fluorescence excitation spectra of disparate tissues and how these spectra change with pathological state. Current imaging diagnostic techniques have limited capacity to investigate fluorescence excitation spectral characteristics. This study utilized excitation-scanning hyperspectral imaging to perform a comprehensive assessment of fluorescence spectral signatures of various tissues. Immediately following tissue harvest, a custom inverted microscope (TE-2000, Nikon Instruments) with Xe arc lamp and thin film tunable filter array (VersaChrome, Semrock, Inc.) were used to acquire hyperspectral image data from each sample. Scans utilized excitation wavelengths from 340 nm to 550 nm in 5 nm increments. Hyperspectral images were analyzed with custom Matlab scripts including linear spectral unmixing (LSU), principal component analysis (PCA), and Gaussian mixture modeling (GMM). Spectra were examined for potential characteristic features such as consistent intensity peaks at specific wavelengths or intensity ratios among significant wavelengths. The resultant spectral features were conserved among tissues of similar molecular composition. Additionally, excitation spectra appear to be a mixture of pure endmembers with commonalities across tissues of varied molecular composition, potentially identifiable through GMM. These results suggest the presence of common autofluorescent molecules in most tissues and that excitationscanning hyperspectral imaging may serve as an approach for characterizing tissue composition as well as pathologic state. Future work will test the feasibility of excitation-scanning hyperspectral imaging as a contrast mode for discriminating normal and pathological tissues.

  1. Reduction of motion artifacts for PET imaging by respiratory correlated dynamic scanning

    International Nuclear Information System (INIS)

    Chuang, K.-S.; Chen, T.-J.; Chang, C.-C.; Wu, J.; Chen, S.; Wu, L.-C.; Liu, R.-S.

    2006-01-01

    Organ motion caused by respiration is a major challenge in positron emission tomography (PET) imaging. This work proposes a technique to reduce smearing in PET imaging caused by respiratory motion. Dynamic scanning at 1 frame/s is used. A point source, used as a marker, is attached to the object's abdomen during the scan. The source position in the projection view moves with respiratory motion and can be used to represent the respiratory phase within the time interval in which each frame data are acquired. One hundred and twenty frames are obtained for each study. The range of the positions of the marker is divided into four groups, representing different respiratory phases. The frames in which the organ positions (phases) are the same summed to produce a static sub-sinogram. Each sub-sinogram then undergoes regular image reconstruction to yield a motion-free image. The technique is applied to one volunteer under both free and coached breathing conditions. A parameter called the volume reduction factor is adopted to evaluate the effectiveness of this motion-reduction technique. The preliminary results indicate that the proposed technique effectively reduces motion artifacts in the image. Coached breathing yields better results than free breathing condition. The advantages of this method are that (1) the scanning time remains the same; (2) free breathing is allowed during the acquisition of the image; and (3) no user intervention is required

  2. Multimodal scanning laser ophthalmoscopy for image guided treatment of age-related macular degeneration

    Science.gov (United States)

    Hammer, Daniel X.; Ferguson, R. D.; Patel, Ankit H.; Iftimia, Nicusor V.; Mujat, Mircea; Husain, Deeba

    2009-02-01

    Subretinal neovascular membranes (SRNM) are a deleterious complication of laser eye injury and retinal diseases such as age-related macular degeneration (AMD), choroiditis, and myopic retinopathy. Photodynamic therapy (PDT) and anti-vascular endothelial growth factor (VEGF) drugs are approved treatment methods. PDT acts by selective dye accumulation, activation by laser light, and disruption and clotting of the new leaky vessels. However, PDT surgery is currently not image-guided, nor does it proceed in an efficient or automated manner. This may contribute to the high rate of re-treatment. We have developed a multimodal scanning laser ophthalmoscope (SLO) for automated diagnosis and image-guided treatment of SRNMs associated with AMD. The system combines line scanning laser ophthalmoscopy (LSLO), fluorescein angiography (FA), indocyanine green angiography (ICGA), PDT laser delivery, and retinal tracking in a compact, efficient platform. This paper describes the system hardware and software design, performance characterization, and automated patient imaging and treatment session procedures and algorithms. Also, we present initial imaging and tracking measurements on normal subjects and automated lesion demarcation and sizing analysis of previously acquired angiograms. Future pre-clinical testing includes line scanning angiography and PDT treatment of AMD subjects. The automated acquisition procedure, enhanced and expedited data post-processing, and innovative image visualization and interpretation tools provided by the multimodal retinal imager may eventually aid in the diagnosis, treatment, and prognosis of AMD and other retinal diseases.

  3. MO-FG-204-02: Reference Image Selection in the Presence of Multiple Scan Realizations

    Energy Technology Data Exchange (ETDEWEB)

    Ruan, D; Dou, T; Thomas, D; Low, D [Deparment of Radiation Oncology, University of California Los Angeles, Los Angeles, CA (United States)

    2015-06-15

    Purpose: Fusing information from multiple correlated realizations (e.g., 4DCT) can improve image quality. This process often involves ill-conditioned and asymmetric nonlinear registration and the proper selection of a reference image is important. This work proposes to examine post-registration variation indirectly for such selection, and develops further insights to reduce the number of cross-registrations needed. Methods: We consider each individual scan as a noisy point in the vicinity of an image manifold, related by motion. Nonrigid registration “transports” a scan along the manifold to the reference neighborhood, and the residual is a surrogate for local variation. To test this conjecture, 10 thoracic scans from the same session were reconstructed from a recently developed low-dose helical 4DCT protocol. Pairwise registration was repeated bi-directionally (81 times) and fusion was performed with each candidate reference. The fused image quality was assessed with SNR and CNR. Registration residuals in SSD, harmonic energy, and deformation Jacobian behavior were examined. The semi-symmetry is further utilized to reduce the number of registration needed. Results: The comparison of image quality between single image and fused ones identified reduction of local intensity variance as the major contributor of image quality, boosting SNR and CNR by 5 to 7 folds. This observation further suggests the criticality of good agreement across post-registration images. Triangle inequality on the SSD metric provides a proficient upper-bound and surrogate on such disagreement. Empirical observation also confirms that fused images with high residual SSD have lower SNR and CNR than the ones with low or intermediate SSDs. Registration SSD is structurally close enough to symmetry for reduced computation. Conclusion: Registration residual is shown to be a good predictor of post-fusion image quality and can be used to identify good reference centers. Semi-symmetry of the

  4. Data Based Parameter Estimation Method for Circular-scanning SAR Imaging

    Directory of Open Access Journals (Sweden)

    Chen Gong-bo

    2013-06-01

    Full Text Available The circular-scanning Synthetic Aperture Radar (SAR is a novel working mode and its image quality is closely related to the accuracy of the imaging parameters, especially considering the inaccuracy of the real speed of the motion. According to the characteristics of the circular-scanning mode, a new data based method for estimating the velocities of the radar platform and the scanning-angle of the radar antenna is proposed in this paper. By referring to the basic conception of the Doppler navigation technique, the mathematic model and formulations for the parameter estimation are firstly improved. The optimal parameter approximation based on the least square criterion is then realized in solving those equations derived from the data processing. The simulation results verified the validity of the proposed scheme.

  5. Determination of line edge roughness in low-dose top-down scanning electron microscopy images

    NARCIS (Netherlands)

    Verduin, T.; Kruit, P.; Hagen, C.W.

    2014-01-01

    We investigated the off-line metrology for line edge roughness (LER) determination by using the discrete power spectral density (PSD). The study specifically addresses low-dose scanning electron microscopy (SEM) images in order to reduce the acquisition time and the risk of resist shrinkage. The

  6. Registration accuracy and image quality of time averaged mid-position CT scans for liver SBRT

    NARCIS (Netherlands)

    Kruis, Matthijs F.; van de Kamer, Jeroen B.; Sonke, Jan-Jakob; Jansen, Edwin P. M.; van Herk, Marcel

    2013-01-01

    The purpose was to validate the accuracy of motion models derived from deformable registration from four-dimensional computed tomography (4DCT) and breath-hold contrast enhanced computed tomography (BHCCT) scans for liver SBRT. Additionally, the image quality of the time averaged mid-position (MidP)

  7. Ionic channels in Langmuir-Blodgett films imaged by a scanning tunneling microscope.

    Science.gov (United States)

    Kolomytkin, O V; Golubok, A O; Davydov, D N; Timofeev, V A; Vinogradova, S A; Tipisev SYa

    1991-01-01

    The molecular structure of channels formed by gramicidin A in a lipid membrane was imaged by a scanning tunneling microscope operating in air. The mono- and bimolecular films of lipid with gramicidin A were deposited onto a highly oriented pyrolitic graphite substrate by the Langmuir-Blodgett technique. It has been shown that under high concentration gramicidin A molecules can form in lipid films a quasi-regular, densely packed structure. Single gramicidin A molecules were imaged for the first time as well. The cavity of 0.4 +/- 0.05 nm in halfwidth was found on the scanning tunneling microscopy image of the gramicidin A molecule. The results of direct observation obtained by means of scanning tunneling microscope are in good agreement with the known molecular model of gramicidin A. It was shown that gramicidin A molecules can exist in a lipid monolayer as individual molecules or combined into clusters. The results demonstrate that scanning tunneling microscope can be used for high spatial resolution study of ionic channel structure. Images FIGURE 1 FIGURE 2 FIGURE 4 FIGURE 5 PMID:1712239

  8. Imaging of surface plasmon polariton interference using phase-sensitive scanning tunneling microscope

    NARCIS (Netherlands)

    Jose, J.; Segerink, Franciscus B.; Korterik, Jeroen P.; Herek, Jennifer Lynn; Offerhaus, Herman L.

    2011-01-01

    We report the surface plasmon polariton interference, generated via a ‘buried’ gold grating, and imaged using a phase-sensitive Photon Scanning Tunneling Microscope (PSTM). The phase-resolved PSTM measurement unravels the complex surface plasmon polariton interference fields at the gold-air

  9. A non-contact time-domain scanning brain imaging system: first in-vivo results

    Science.gov (United States)

    Mazurenka, M.; Di Sieno, L.; Boso, G.; Contini, D.; Pifferi, A.; Dalla Mora, A.; Tosi, A.; Wabnitz, H.; Macdonald, R.

    2013-06-01

    We present results of first in-vivo tests of an optical non-contact scanning imaging system, intended to study oxidative metabolism related processes in biological tissue by means of time-resolved near-infrared spectroscopy. Our method is a novel realization of the short source-detector separation approach and based on a fast-gated single-photon avalanche diode to detect late photons only. The scanning system is built in quasi-confocal configuration and utilizes polarizationsensitive detection. It scans an area of 4×4 cm2, recording images with 32×32 pixels, thus creating a high density of source-detector pairs. To test the system we performed a range of in vivo measurements of hemodynamic changes in several types of biological tissues, i.e. skin (Valsalva maneuver), muscle (venous and arterial occlusions) and brain (motor and cognitive tasks). Task-related changes in hemoglobin concentrations were clearly detected in skin and muscle. The brain activation shows weaker, but yet detectable changes. These changes were localized in pixels near the motor cortex area (C3). However, it was found that even very short hair substantially impairs the measurement. Thus the applicability of the scanner is limited to hairless parts of body. The results of our first in-vivo tests prove the feasibility of non-contact scanning imaging as a first step towards development of a prototype for biological tissue imaging for various medical applications.

  10. Line-scan macro-scale Raman chemical imaging for authentication of powdered foods and ingredients

    Science.gov (United States)

    Adulteration and fraud for powdered foods and ingredients are rising food safety risks that threaten consumers’ health. In this study, a newly developed line-scan macro-scale Raman imaging system using a 5 W 785 nm line laser as excitation source was used to authenticate the food powders. The system...

  11. Covalently Immobilised Cytochrome C Imaged by In Situ Scanning Tunnelling Microscopy

    DEFF Research Database (Denmark)

    Andersen, Jens Enevold Thaulov; Olesen, Klaus G.; Danilov, Alexey I.

    1997-01-01

    In situ scanning tunnelling microscopy (STM) imaging of cytochrome c (cyt c) on polycrystalline Pt surfaces and on Au(lll) was achieved first by covalent immobilisation of 3-aminopropyltriethoxysilane (3-APTS) brought to react with oxide present on the Pt surfaces. Covalently bound 3-APTS forms...

  12. Automatic prostate localization on cone-beam CT scans for high precision image-guided radiotherapy

    NARCIS (Netherlands)

    Smitsmans, Monique H. P.; de Bois, Josien; Sonke, Jan-Jakob; Betgen, Anja; Zijp, Lambert J.; Jaffray, David A.; Lebesque, Joos V.; van Herk, Marcel

    2005-01-01

    PURPOSE: Previously, we developed an automatic three-dimensional gray-value registration (GR) method for fast prostate localization that could be used during online or offline image-guided radiotherapy. The method was tested on conventional computed tomography (CT) scans. In this study, the

  13. Experimental investigation on the caries characteristic of dental tissues by photothermal radiometry scanning imaging

    Science.gov (United States)

    Wang, Fei; Liu, Jun-yan; Wang, Xiao-chun; Wang, Yang

    2018-03-01

    In this paper, a one-dimensional (1D) thermal-wave model coupled diffuse-photon-density-wave for three-layer dental tissues using modulated laser stimulation was employed to illustrate the relationship between dental caries characteristic (i.e. caries layer thickness, optical absorption coefficient and optical scattering coefficient) and photothermal radiometry (PTR) signal. Experimental investigation of artificial caries was carried out using PTR scanning imaging. The PTR amplitude and phase delay were increased with dental demineralized treatment. The local caries characteristic parameters were obtained by the best-fitting method based on the 1D thermal-wave model. The PTR scanning imaging measurements illustrated that the optical absorption coefficient and scattering coefficient of caries region were much higher than those of the healthy enamel area. The demineralization thickness of caries region was measured by PTR scanning imaging and its average value shows in good agreement with the digital microscope. Experimental results show that PTR scanning imaging has the merits of high contrast for local inhomogeneity of dental caries; furthermore, this method is an allowance to provide a flexibility for non-contact quantitative evaluation of dental caries.

  14. A storage and display method for radioisotope imaging using scan conversion memory

    International Nuclear Information System (INIS)

    Takizawa, Masaomi; Kobayashi, Toshio; Nakanishi, Fumiko; Suzuki, Shigeo; Miyabayashi, Hiroyasu

    1975-01-01

    The scan conversion memory (SCM) has been applied to a method for the storage and display of radioisotope images. Scan data were fed into SCM as pulse signals with X and Y axis from the scinti-scanner or the scinti-camera. The electric charge on the SCM target is directly proportional to the pulse density. A TV display was executed immediately after the recording of a radioisotope image. If necessary, a seven additive color display to the image density could be obtained by a simple color slicer, and the image could be hard-copied by a video hard-copy printer. Characteristics of the SCM were experimentally clarified as follows: the practical resolution was 700 line/TV; ten levels gray scale were discriminated on the video monitor, the uniformity, measured by an oscilloscope was less than 20%, and dead time of the pulse interval at full scale signal was 5 μ sec. In their representation, the SCM scintigrams were observed as closely resembling conventional film scintigrams. Superimposed imaging of an X-ray picture and a radioisotope image can be realized by using the SCM, for an increase in anatomical localization on reading images. The SCM scintigram can be applied rapidly and can be the viewer of radioisotope imaging. (auth.)

  15. Study of CT head scans using different voltages: image quality evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Pacheco de Freitas C, I.; Prata M, A. [Centro Federal de Educacao Tecnologica de Minas Gerais, Centro de Engenharia Biomedica, Av. Amazonas 5253, 30421-169 Nova Suica, Belo Horizonte, Minas Gerais (Brazil); Alonso, T. C. [Centro de Desenvolvimento da Tecnologia Nuclear / CNEN, Av. Pte. Antonio Carlos 6627, 31270-901 Pampulha, Belo Horizonte, Minas Gerais (Brazil); Santana, P., E-mail: iarapfcorrea@gmail.com [Universidade Federal de Minas Gerais, Departamento de Anatomia e Imagem, Av. Prof. Alfredo Balena 190, 30130-100 Belo Horizonte, Minas Gerais (Brazil)

    2016-10-15

    Computed tomography (CT) was introduced to medical practice in 1972. It generates images recognized by high diagnostic potential. CT allows investigation of structures in the human body inaccessible by conventional image methods, replacing invasive methods in many cases. Noise is a kind of variation of brightness observed on CT images, and it is inherent to this method. The magnitude of the noise is determined by the standard deviation of CT numbers of a region of interest in a homogeneous material. The aim of this study is to analyze the noise in head CT images generated by different acquisition protocols using four voltage values. Five different scans were performed using a female Alderson phantom and their images were analyzed with the RadiAnt software. With the average HU values and standard deviation of each scan, the values of noise were calculated in some region of interest. The obtained noise values were compared and it was observed that the 140 kV voltage promotes the in the lower noise in the image, resulting in better image quality. The results also show that the parameters, such as voltage and current, can be adjusted so that the noise can be decreased. Thus, acquisition protocols may be adapted to produce images with diagnostic quality and lower doses in patient. (Author)

  16. Study of CT head scans using different voltages: image quality evaluation

    International Nuclear Information System (INIS)

    Pacheco de Freitas C, I.; Prata M, A.; Alonso, T. C.; Santana, P.

    2016-10-01

    Computed tomography (CT) was introduced to medical practice in 1972. It generates images recognized by high diagnostic potential. CT allows investigation of structures in the human body inaccessible by conventional image methods, replacing invasive methods in many cases. Noise is a kind of variation of brightness observed on CT images, and it is inherent to this method. The magnitude of the noise is determined by the standard deviation of CT numbers of a region of interest in a homogeneous material. The aim of this study is to analyze the noise in head CT images generated by different acquisition protocols using four voltage values. Five different scans were performed using a female Alderson phantom and their images were analyzed with the RadiAnt software. With the average HU values and standard deviation of each scan, the values of noise were calculated in some region of interest. The obtained noise values were compared and it was observed that the 140 kV voltage promotes the in the lower noise in the image, resulting in better image quality. The results also show that the parameters, such as voltage and current, can be adjusted so that the noise can be decreased. Thus, acquisition protocols may be adapted to produce images with diagnostic quality and lower doses in patient. (Author)

  17. Achievement report for fiscal 1999 on research and development of technologies for medical welfare equipment. Chromosome image analysis and diagnosis device with confocal scanning laser microscope; 1999 nendo iryo fukushi kiki gijutsu kenkyu kaihatsu seika hokokusho. Kyoshoten laser kenbikyo ni yoru zensenshokutai gazo kaiseki shindan sochi

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-05-01

    The device is now satisfactorily capable of all image processing functions (bi-levelling, color deviation, brilliance adjustment, etc.) with the exception the karyotyping function. A substance that emits fluorescence by laser excitation is developed (for labelling the probe). A direct labelling method is studied, in which nucleic acid probes (nucleic acid labelled for chromosomal identification) will prove to be remarkably high in sensitivity. A new fluorescent reagent is synthesized, which is a BHHCT-4-dUTP to act as a nucleic acid probe. It is found that the new substance is superior to the conventional fluorescent substances in terms of stability and that all chromosomes may be forced into hybridization (selective combination of a probe with a peculiar chromosome) when various probes are labelled by this substance. A programing unit is constructed for a chromosomal aberration database. Items needed relative to chromosomes and parameters relative to chromosomal aberration data are appropriately arranged, and conditions to satisfy for their development into a database are studied. A rough design of an interface is complete. (NEDO)

  18. Audiovisual biofeedback improves image quality and reduces scan time for respiratory-gated 3D MRI

    International Nuclear Information System (INIS)

    Lee, D; Keall, P; Kim, T; Greer, P B; Arm, J

    2014-01-01

    The purpose of this study was to test the hypothesis that audiovisual (AV) biofeedback can improve image quality and reduce scan time for respiratory-gated 3D thoracic MRI. For five healthy human subjects respiratory motion guidance in MR scans was provided using an AV biofeedback system, utilizing real-time respiratory motion signals. To investigate the improvement of respiratory-gated 3D MR images between free breathing (FB) and AV biofeedback (AV), each subject underwent two imaging sessions. Respiratory-related motion artifacts and imaging time were qualitatively evaluated in addition to the reproducibility of external (abdominal) motion. In the results, 3D MR images in AV biofeedback showed more anatomic information such as a clear distinction of diaphragm, lung lobes and sharper organ boundaries. The scan time was reduced from 401±215 s in FB to 334±94 s in AV (p-value 0.36). The root mean square variation of the displacement and period of the abdominal motion was reduced from 0.4±0.22 cm and 2.8±2.5 s in FB to 0.1±0.15 cm and 0.9±1.3 s in AV (p-value of displacement <0.01 and p-value of period 0.12). This study demonstrated that audiovisual biofeedback improves image quality and reduces scan time for respiratory-gated 3D MRI. These results suggest that AV biofeedback has the potential to be a useful motion management tool in medical imaging and radiation therapy procedures.

  19. Evaluation of Image Quality in Low Tube-Voltage Chest CT Scan

    International Nuclear Information System (INIS)

    Kim, Hyun Ju; Cho, Jae Hwan; Park, Cheol Soo

    2010-01-01

    The patients who visited this department for pulmonary disease and need CT scans for Follow-up to observe change of CT value, evaluation of image quality and decrease of radiation dose as change of kVp. Subjects were the patients of 20 persons visited this department for pulmonary disease and Somatom Sensation 16(Semens, Enlarge, Germany) was used. Measurement of CT value as change of kVp was done by setting up ROI diameter of 1cm at the height of thyroid, aortic arch, right pulmonary artery in arterial phase image using 100 kVp, measuring 3 times, and recorded the average. CT value of phantom was measured by scanning phantoms which means contrast media diluted by normal saline by various ratio with tube voltage of 80 kVp, 100 kVp, 120 kVp, 140 kVp and recorded the average of 3 CT values of center of phantom image. In analysing radiation dose, CTDIVOL values of the latest arterial phase image of 120 kVp and as this research set that of 100 kVp were analyzed comparatively. 2 observers graded quality of chest images by 5 degrees (Unacceptable, Suboptimal, Adequate, Good, Excellent). CT value of chest image increased at 100 kVp by 14.06%∼27.26% in each ROI than 120 kVp. CT value of phantom increased as tube voltage lowered at various concentration of contrast media. CTDIVOL decreased at 100 kVp(5.00 mGy) by 36% than 120 kVp(7.80 mGy) in radiation dose analysis. here were 0 Unacceptable, 1 Suboptimal, 3 Adequate, 10 Good, 6 Excellent in totally 20 persons. Chest CT scanning with low kilo-voltage for patients who need CT scan repeatedly can bring images valuable for diagnose, and decrease radiation dose against patients

  20. Concave omnidirectional imaging device for cylindrical object based on catadioptric panoramic imaging

    Science.gov (United States)

    Wu, Xiaojun; Wu, Yumei; Wen, Peizhi

    2018-03-01

    To obtain information on the outer surface of a cylinder object, we propose a catadioptric panoramic imaging system based on the principle of uniform spatial resolution for vertical scenes. First, the influence of the projection-equation coefficients on the spatial resolution and astigmatism of the panoramic system are discussed, respectively. Through parameter optimization, we obtain the appropriate coefficients for the projection equation, and so the imaging quality of the entire imaging system can reach an optimum value. Finally, the system projection equation is calibrated, and an undistorted rectangular panoramic image is obtained using the cylindrical-surface projection expansion method. The proposed 360-deg panoramic-imaging device overcomes the shortcomings of existing surface panoramic-imaging methods, and it has the advantages of low cost, simple structure, high imaging quality, and small distortion, etc. The experimental results show the effectiveness of the proposed method.

  1. Safety of Magnetic Resonance Imaging in Patients with Cardiac Devices.

    Science.gov (United States)

    Nazarian, Saman; Hansford, Rozann; Rahsepar, Amir A; Weltin, Valeria; McVeigh, Diana; Gucuk Ipek, Esra; Kwan, Alan; Berger, Ronald D; Calkins, Hugh; Lardo, Albert C; Kraut, Michael A; Kamel, Ihab R; Zimmerman, Stefan L; Halperin, Henry R

    2017-12-28

    Patients who have pacemakers or defibrillators are often denied the opportunity to undergo magnetic resonance imaging (MRI) because of safety concerns, unless the devices meet certain criteria specified by the Food and Drug Administration (termed "MRI-conditional" devices). We performed a prospective, nonrandomized study to assess the safety of MRI at a magnetic field strength of 1.5 Tesla in 1509 patients who had a pacemaker (58%) or an implantable cardioverter-defibrillator (42%) that was not considered to be MRI-conditional (termed a "legacy" device). Overall, the patients underwent 2103 thoracic and nonthoracic MRI examinations that were deemed to be clinically necessary. The pacing mode was changed to asynchronous mode for pacing-dependent patients and to demand mode for other patients. Tachyarrhythmia functions were disabled. Outcome assessments included adverse events and changes in the variables that indicate lead and generator function and interaction with surrounding tissue (device parameters). No long-term clinically significant adverse events were reported. In nine MRI examinations (0.4%; 95% confidence interval, 0.2 to 0.7), the patient's device reset to a backup mode. The reset was transient in eight of the nine examinations. In one case, a pacemaker with less than 1 month left of battery life reset to ventricular inhibited pacing and could not be reprogrammed; the device was subsequently replaced. The most common notable change in device parameters (>50% change from baseline) immediately after MRI was a decrease in P-wave amplitude, which occurred in 1% of the patients. At long-term follow-up (results of which were available for 63% of the patients), the most common notable changes from baseline were decreases in P-wave amplitude (in 4% of the patients), increases in atrial capture threshold (4%), increases in right ventricular capture threshold (4%), and increases in left ventricular capture threshold (3%). The observed changes in lead parameters

  2. Acoustic Imaging of Selected Areas of Gdansk Bay with the Aid of Parametric Echosounder and Side-Scan Sonar

    Directory of Open Access Journals (Sweden)

    Grelowska Grażyna

    2017-12-01

    Full Text Available The article presents and analyses the data recorded during sounding of the Gdansk Bay seabed with the aid of a parametric echosounder and a side-scan sonar. The accuracy of seabed structure examination, as a condition for obtaining valuable results, requires correct configuration of echolocation devices and proper calibration of peripheral devices, such as the survey unit geographical position sensor - GPS, the navigation unit, the MRU-Z sensor of pitch, roll and heave, and the sound velocity meter, which deliver the data to the bathymetric measurement system. Parametric seabed profilers deliver two types of data: the envelope, and the detailed echo signal without processing. The envelope is used for data visualisation in the form of online echograms, while the echo signal is stored for further analyses, to be performed using dedicated software or, after relevant conversion, in arbitrary programming environment1. The presented data analysis is illustrated by selected sample images recorded by the parametric echosounder and the side-scan sonar during Gdansk Bay sounding.

  3. Scanning multiple mice in a small-animal PET scanner: Influence on image quality

    International Nuclear Information System (INIS)

    Siepel, Francoise J.; Lier, Monique G.J.T.B. van; Chen Mu; Disselhorst, Jonathan A.; Meeuwis, Antoi P.W.; Oyen, Wim J.G.; Boerman, Otto C.; Visser, Eric P.

    2010-01-01

    To achieve high throughput in small-animal positron emission tomography (PET), it may be advantageous to scan more than one animal in the scanner's field of view (FOV) at the same time. However, due to the additional activity and increase of Poisson noise, additional attenuating mass, extra photon scattering, and radial or axial displacement of the animals, a deterioration of image quality can be expected. In this study, the NEMA NU 4-2008 image quality (NU4IQ) phantom and up to three FDG-filled cylindrical 'mouse phantoms' were positioned in the FOV of the Siemens Inveon small-animal PET scanner to simulate scans with multiple mice. Five geometrical configurations were examined. In one configuration, the NU4IQ phantom was scanned separately and placed in the center of the FOV (1C). In two configurations, a mouse phantom was added with both phantoms displaced radially (2R) or axially (2A). In two other configurations, the NU4IQ phantom was scanned along with three mouse phantoms with all phantoms displaced radially (4R), or in a combination of radial and axial displacement (2R2A). Images were reconstructed using ordered subset expectation maximization in 2 dimensions (OSEM2D) and maximum a posteriori (MAP) reconstruction. Image quality parameters were obtained according to the NEMA NU 4-2008 guidelines. Optimum image quality was obtained for the 1C geometry. Image noise increased by the addition of phantoms and was the largest for the 4R configuration. Spatial resolution, reflected in the recovery coefficients for the FDG-filled rods, deteriorated by radial displacement of the NU4IQ phantom (2R, 2R2A, and 4R), most strongly for OSEM2D, and to a smaller extent for MAP reconstructions. Photon scatter, as indicated by the spill-over ratios in the non-radioactive water- and air-filled compartments, increased by the addition of phantoms, most strongly for the 4R configuration. Application of scatter correction substantially lowered the spill-over ratios, but caused an

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

    International Nuclear Information System (INIS)

    Kwok, J.C.K.; Yu, P.K.N.; Cheng, A.Y.S.; Ho, W.C.

    1991-01-01

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

  5. Fermi surface contours obtained from scanning tunneling microscope images around surface point defects

    International Nuclear Information System (INIS)

    Khotkevych-Sanina, N V; Kolesnichenko, Yu A; Van Ruitenbeek, J M

    2013-01-01

    We present a theoretical analysis of the standing wave patterns in scanning tunneling microscope (STM) images, which occur around surface point defects. We consider arbitrary dispersion relations for the surface states and calculate the conductance for a system containing a small-size tunnel contact and a surface impurity. We find rigorous theoretical relations between the interference patterns in the real-space STM images, their Fourier transforms and the Fermi contours of two-dimensional electrons. We propose a new method for reconstructing Fermi contours of surface electron states, directly from the real-space STM images around isolated surface defects. (paper)

  6. Dynamics of annular bright field imaging in scanning transmission electron microscopy

    International Nuclear Information System (INIS)

    Findlay, S.D.; Shibata, N.; Sawada, H.; Okunishi, E.; Kondo, Y.; Ikuhara, Y.

    2010-01-01

    We explore the dynamics of image formation in the so-called annular bright field mode in scanning transmission electron microscopy, whereby an annular detector is used with detector collection range lying within the cone of illumination, i.e. the bright field region. We show that this imaging mode allows us to reliably image both light and heavy columns over a range of thickness and defocus values, and we explain the contrast mechanisms involved. The role of probe and detector aperture sizes is considered, as is the sensitivity of the method to intercolumn spacing and local disorder.

  7. Image quality of high-resolution CT with 16-channel multidetector-row CT. Comparison between helical scan and conventional step-shoot scan

    International Nuclear Information System (INIS)

    Sumikawa, Hiromitsu; Johkoh, Takeshi; Koyama, Mitsuhiro

    2005-01-01

    The aim of this study was to evaluate the image quality of high-resolution CT (HRCT) reconstructed from volumetric data with 16-channel multidetector-row CT (MDCT). Eleven autopsy lungs that were diagnosed histopathologically were scanned by 16-channel MDCT with the step-and-shoot scan mode and three helical scan modes. Each helical mode had each size of focal spot, pitch, and time of gantry rotation. HRCT images were reconstructed from the volumetric data with each helical mode and axial sequence data. Two observers evaluated the image quality and noted the most appropriate diagnosis for each imaging. Visualization of abnormal structures with one helical mode was equal to those with axial mode, whereas those with the other two helical modes were inferior to those with axial mode (Wilcoxon signed rank test; p<0.0001). There was no significant difference in diagnostic efficacy between modes. The image quality of HRCT with appropriate helical mode is equal to that with axial mode and diagnostic efficacy is equal among all modes. These results may indicate that sufficient HRCT images can be obtained by only one helical scan without the addition of conventional axial scans. (author)

  8. Validation of phalanx bone three-dimensional surface segmentation from computed tomography images using laser scanning

    Energy Technology Data Exchange (ETDEWEB)

    DeVries, Nicole A.; Gassman, Esther E.; Kallemeyn, Nicole A. [The University of Iowa, Department of Biomedical Engineering, Center for Computer Aided Design, Iowa City, IA (United States); Shivanna, Kiran H. [The University of Iowa, Center for Computer Aided Design, Iowa City, IA (United States); Magnotta, Vincent A. [The University of Iowa, Department of Biomedical Engineering, Department of Radiology, Center for Computer Aided Design, Iowa City, IA (United States); Grosland, Nicole M. [The University of Iowa, Department of Biomedical Engineering, Department of Orthopaedics and Rehabilitation, Center for Computer Aided Design, Iowa City, IA (United States)

    2008-01-15

    To examine the validity of manually defined bony regions of interest from computed tomography (CT) scans. Segmentation measurements were performed on the coronal reformatted CT images of the three phalanx bones of the index finger from five cadaveric specimens. Two smoothing algorithms (image-based and Laplacian surface-based) were evaluated to determine their ability to represent accurately the anatomic surface. The resulting surfaces were compared with laser surface scans of the corresponding cadaveric specimen. The average relative overlap between two tracers was 0.91 for all bones. The overall mean difference between the manual unsmoothed surface and the laser surface scan was 0.20 mm. Both image-based and Laplacian surface-based smoothing were compared; the overall mean difference for image-based smoothing was 0.21 mm and 0.20 mm for Laplacian smoothing. This study showed that manual segmentation of high-contrast, coronal, reformatted, CT datasets can accurately represent the true surface geometry of bones. Additionally, smoothing techniques did not significantly alter the surface representations. This validation technique should be extended to other bones, image segmentation and spatial filtering techniques. (orig.)

  9. Validation of phalanx bone three-dimensional surface segmentation from computed tomography images using laser scanning

    International Nuclear Information System (INIS)

    DeVries, Nicole A.; Gassman, Esther E.; Kallemeyn, Nicole A.; Shivanna, Kiran H.; Magnotta, Vincent A.; Grosland, Nicole M.

    2008-01-01

    To examine the validity of manually defined bony regions of interest from computed tomography (CT) scans. Segmentation measurements were performed on the coronal reformatted CT images of the three phalanx bones of the index finger from five cadaveric specimens. Two smoothing algorithms (image-based and Laplacian surface-based) were evaluated to determine their ability to represent accurately the anatomic surface. The resulting surfaces were compared with laser surface scans of the corresponding cadaveric specimen. The average relative overlap between two tracers was 0.91 for all bones. The overall mean difference between the manual unsmoothed surface and the laser surface scan was 0.20 mm. Both image-based and Laplacian surface-based smoothing were compared; the overall mean difference for image-based smoothing was 0.21 mm and 0.20 mm for Laplacian smoothing. This study showed that manual segmentation of high-contrast, coronal, reformatted, CT datasets can accurately represent the true surface geometry of bones. Additionally, smoothing techniques did not significantly alter the surface representations. This validation technique should be extended to other bones, image segmentation and spatial filtering techniques. (orig.)

  10. High-speed imaging upgrade for a standard sample scanning atomic force microscope using small cantilevers

    Energy Technology Data Exchange (ETDEWEB)

    Adams, Jonathan D.; Nievergelt, Adrian; Erickson, Blake W.; Yang, Chen; Dukic, Maja; Fantner, Georg E., E-mail: georg.fantner@epfl.ch [Ecole Polytechnique Fédérale de Lausanne, Lausanne (Switzerland)

    2014-09-15

    We present an atomic force microscope (AFM) head for optical beam deflection on small cantilevers. Our AFM head is designed to be small in size, easily integrated into a commercial AFM system, and has a modular architecture facilitating exchange of the optical and electronic assemblies. We present two different designs for both the optical beam deflection and the electronic readout systems, and evaluate their performance. Using small cantilevers with our AFM head on an otherwise unmodified commercial AFM system, we are able to take tapping mode images approximately 5–10 times faster compared to the same AFM system using large cantilevers. By using additional scanner turnaround resonance compensation and a controller designed for high-speed AFM imaging, we show tapping mode imaging of lipid bilayers at line scan rates of 100–500 Hz for scan areas of several micrometers in size.

  11. Ribbon scanning confocal for high-speed high-resolution volume imaging of brain.

    Directory of Open Access Journals (Sweden)

    Alan M Watson

    Full Text Available Whole-brain imaging is becoming a fundamental means of experimental insight; however, achieving subcellular resolution imagery in a reasonable time window has not been possible. We describe the first application of multicolor ribbon scanning confocal methods to collect high-resolution volume images of chemically cleared brains. We demonstrate that ribbon scanning collects images over ten times faster than conventional high speed confocal systems but with equivalent spectral and spatial resolution. Further, using this technology, we reconstruct large volumes of mouse brain infected with encephalitic alphaviruses and demonstrate that regions of the brain with abundant viral replication were inaccessible to vascular perfusion. This reveals that the destruction or collapse of large regions of brain micro vasculature may contribute to the severe disease caused by Venezuelan equine encephalitis virus. Visualization of this fundamental impact of infection would not be possible without sampling at subcellular resolution within large brain volumes.

  12. Evaluation of Yogurt Microstructure Using Confocal Laser Scanning Microscopy and Image Analysis.

    Science.gov (United States)

    Skytte, Jacob L; Ghita, Ovidiu; Whelan, Paul F; Andersen, Ulf; Møller, Flemming; Dahl, Anders B; Larsen, Rasmus

    2015-06-01

    The microstructure of protein networks in yogurts defines important physical properties of the yogurt and hereby partly its quality. Imaging this protein network using confocal scanning laser microscopy (CSLM) has shown good results, and CSLM has become a standard measuring technique for fermented dairy products. When studying such networks, hundreds of images can be obtained, and here image analysis methods are essential for using the images in statistical analysis. Previously, methods including gray level co-occurrence matrix analysis and fractal analysis have been used with success. However, a range of other image texture characterization methods exists. These methods describe an image by a frequency distribution of predefined image features (denoted textons). Our contribution is an investigation of the choice of image analysis methods by performing a comparative study of 7 major approaches to image texture description. Here, CSLM images from a yogurt fermentation study are investigated, where production factors including fat content, protein content, heat treatment, and incubation temperature are varied. The descriptors are evaluated through nearest neighbor classification, variance analysis, and cluster analysis. Our investigation suggests that the texton-based descriptors provide a fuller description of the images compared to gray-level co-occurrence matrix descriptors and fractal analysis, while still being as applicable and in some cases as easy to tune. © 2015 Institute of Food Technologists®

  13. SmartScan: a robust pushbroom imaging concept for moderate spacecraft attitude stability

    Science.gov (United States)

    Janschek, K.; Tchernykh, V.; Dyblenko, S.; Harnisch, B.

    2017-11-01

    Pushbroom scan cameras with linear image sensors, commonly used for Earth observation from satellites, require high attitude stability during the image acquisition. Especially noticeable are the effects of high frequency attitude variations originating from micro shocks and vibrations, produced by momentum and reaction wheels, mechanically activated coolers, steering and deployment mechanics and other reasons. The SMARTSCAN imaging concept offers high quality imaging even with moderate satellite attitude stability on a sole opto-electronic basis without any moving parts. It uses real-time recording of the actual image motion in the focal plane of the remote sensing camera during the frame acquisition and a posteriori correction of the obtained image distortions on base of the image motion record. Exceptional real-time performances with subpixel accuracy image motion measurement are provided by an innovative high-speed onboard optoelectronic correlation processor. SMARTSCAN allows therefore using smart pushbroom cameras for hyper-spectral imagers on satellites and platforms which are not specially intended for imaging missions, e.g. micro satellites. The paper gives an overview on the system concept and main technologies used (advanced optical correlator for ultra high-speed image motion tracking), it discusses the conceptual design for a smart compact space camera and it reports on airborne test results of a functional breadboard model.

  14. Micro and nano devices in passive millimetre wave imaging systems

    Science.gov (United States)

    Appleby, R.

    2013-06-01

    The impact of micro and nano technology on millimetre wave imaging from the post war years to the present day is reviewed. In the 1950s whisker contacted diodes in mixers and vacuum tubes were used to realise both radiometers and radars but required considerable skill to realise the performance needed. Development of planar semiconductor devices such as Gunn and Schottky diodes revolutionised mixer performance and provided considerable improvement. The next major breakthrough was high frequency transistors based on gallium arsenide which were initially used at intermediate frequencies but later after further development at millimeter wave frequencies. More recently Monolithic Microwave Integrated circuits(MMICs) offer exceptional performance and the opportunity for innovative design in passive imaging systems. In the future the use of micro and nano technology will continue to drive system performance and we can expect to see integration of antennae, millimetre wave and sub millimetre wave circuits and signal processing.

  15. Quantitative sub-surface and non-contact imaging using scanning microwave microscopy

    International Nuclear Information System (INIS)

    Gramse, Georg; Kasper, Manuel; Hinterdorfer, Peter; Brinciotti, Enrico; Rankl, Christian; Kienberger, Ferry; Lucibello, Andrea; Marcelli, Romolo; Patil, Samadhan B.; Giridharagopal, Rajiv

    2015-01-01

    The capability of scanning microwave microscopy for calibrated sub-surface and non-contact capacitance imaging of silicon (Si) samples is quantitatively studied at broadband frequencies ranging from 1 to 20 GHz. Calibrated capacitance images of flat Si test samples with varying dopant density (10 15 –10 19 atoms cm −3 ) and covered with dielectric thin films of SiO 2 (100–400 nm thickness) are measured to demonstrate the sensitivity of scanning microwave microscopy (SMM) for sub-surface imaging. Using standard SMM imaging conditions the dopant areas could still be sensed under a 400 nm thick oxide layer. Non-contact SMM imaging in lift-mode and constant height mode is quantitatively demonstrated on a 50 nm thick SiO 2 test pad. The differences between non-contact and contact mode capacitances are studied with respect to the main parameters influencing the imaging contrast, namely the probe tip diameter and the tip–sample distance. Finite element modelling was used to further analyse the influence of the tip radius and the tip–sample distance on the SMM sensitivity. The understanding of how the two key parameters determine the SMM sensitivity and quantitative capacitances represents an important step towards its routine application for non-contact and sub-surface imaging. (paper)

  16. ANALYSIS OF MOBILE LASER SCANNING DATA AND MULTI-VIEW IMAGE RECONSTRUCTION

    Directory of Open Access Journals (Sweden)

    C. Briese

    2012-07-01

    Full Text Available The combination of laser scanning (LS, active, direct 3D measurement of the object surface and photogrammetry (high geometric and radiometric resolution is widely applied for object reconstruction (e.g. architecture, topography, monitoring, archaeology. Usually the results are a coloured point cloud or a textured mesh. The geometry is typically generated from the laser scanning point cloud and the radiometric information is the result of image acquisition. In the last years, next to significant developments in static (terrestrial LS and kinematic LS (airborne and mobile LS hardware and software, research in computer vision and photogrammetry lead to advanced automated procedures in image orientation and image matching. These methods allow a highly automated generation of 3D geometry just based on image data. Founded on advanced feature detector techniques (like SIFT (Scale Invariant Feature Transform very robust techniques for image orientation were established (cf. Bundler. In a subsequent step, dense multi-view stereo reconstruction algorithms allow the generation of very dense 3D point clouds that represent the scene geometry (cf. Patch-based Multi-View Stereo (PMVS2. Within this paper the usage of mobile laser scanning (MLS and simultaneously acquired image data for an advanced integrated scene reconstruction is studied. For the analysis the geometry of a scene is generated by both techniques independently. Then, the paper focuses on the quality assessment of both techniques. This includes a quality analysis of the individual surface models and a comparison of the direct georeferencing of the images using positional and orientation data of the on board GNSS-INS system and the indirect georeferencing of the imagery by automatic image orientation. For the practical evaluation a dataset from an archaeological monument is utilised. Based on the gained knowledge a discussion of the results is provided and a future strategy for the integration of

  17. In situ KPFM imaging of local photovoltaic characteristics of structured organic photovoltaic devices.

    Science.gov (United States)

    Watanabe, Satoshi; Fukuchi, Yasumasa; Fukasawa, Masako; Sassa, Takafumi; Kimoto, Atsushi; Tajima, Yusuke; Uchiyama, Masanobu; Yamashita, Takashi; Matsumoto, Mutsuyoshi; Aoyama, Tetsuya

    2014-02-12

    Here, we discuss the local photovoltaic characteristics of a structured bulk heterojunction, organic photovoltaic devices fabricated with a liquid carbazole, and a fullerene derivative based on analysis by scanning kelvin probe force microscopy (KPFM). Periodic photopolymerization induced by an interference pattern from two laser beams formed surface relief gratings (SRG) in the structured films. The surface potential distribution in the SRGs indicates the formation of donor and acceptor spatial distribution. Under illumination, the surface potential reversibly changed because of the generation of fullerene anions and hole transport from the films to substrates, which indicates that we successfully imaged the local photovoltaic characteristics of the structured photovoltaic devices. Using atomic force microscopy, we confirmed the formation of the SRG because of the material migration to the photopolymerized region of the films, which was induced by light exposure through photomasks. The structuring technique allows for the direct fabrication and the control of donor and acceptor spatial distribution in organic photonic and electronic devices with minimized material consumption. This in situ KPFM technique is indispensable to the fabrication of nanoscale electron donor and electron acceptor spatial distribution in the devices.

  18. Myocardial perfusion imaging and coronary calcium scoring with a two-slice SPECT/CT system: can the attenuation map be calculated from the calcium scoring CT scan?

    Energy Technology Data Exchange (ETDEWEB)

    Wenning, Christian; Rahbar, Kambiz; Schober, Otmar; Stegger, Lars [University of Muenster, Department of Nuclear Medicine, Muenster (Germany); Vrachimis, Alexis; Schaefers, Michael [University of Muenster, Department of Nuclear Medicine, Muenster (Germany); University of Muenster, European Institute for Molecular Imaging, Muenster (Germany)

    2013-07-15

    Coronary artery calcium scoring can complement myocardial perfusion imaging (MPI). The purpose of this study was to evaluate the feasibility and accuracy of using the CalciumScore-CT derived from a combined SPECT/CT device also for SPECT attenuation correction (AC). The study group comprised 99 patients who underwent both post-stress and rest MPI using a two-slice SPECT/CT system. For AC, one of the two scans was accompanied by a CalciumScore-CT scan (CalciumScore-CTAC) and the other by a conventional spiral CT (AttenCorr-CT) scan (AttenCorr-CTAC). In 48 patients the CalciumScore-CT scan was acquired with the post-stress scan and the AttenCorr-CT scan with the rest scan, and in 51 patients the order was reversed. The accuracy of the images based on AC was determined qualitatively by consensus reading with respect to the clinical diagnoses as well as quantitatively by comparing the perfusion summed stress scores (SSS) and the summed rest scores (SRS) between attenuation-corrected and uncorrected images. In comparison to the uncorrected images CalciumScore-CTAC led to regional inaccuracies in 14 of 51 of studies (27.5 %) versus 12 of 48 studies (25 %) with AttenCorr-CTAC for the stress studies and in 5 of 48 (10 %) versus 1 of 51 (2 %) for the rest studies, respectively. This led to intermediate and definite changes in the final diagnosis (ischaemia and/or scarring) in 12 % of the studies (12 of 99) and in 7 % of the studies (7 of 99) with CalciumScore-CTAC and in 9 % of the studies (9 of 99) and 4 % of the studies (4 of 99) with AttenCorr-CTAC. Differences in SSS and SRS with respect to the uncorrected images were greater for the CalciumScore-CTAC images than for the AttenCorr-CTAC images ({Delta}SSS 4.5 {+-} 5.6 and 2.1 {+-} 4.4, p = 0.023; {Delta}SRS 4.2 {+-} 4.9 and 1.6 {+-} 3.2, p = 0.004, respectively). Using the same CT scan for calcium scoring and SPECT AC is feasible. Image interpretation must, however, include uncorrected images since CT-based AC relatively

  19. X-CT imaging method for large objects using double offset scan mode

    International Nuclear Information System (INIS)

    Fu Jian; Lu Hongnian; Li Bing; Zhang Lei; Sun Jingjing

    2007-01-01

    In X-ray computed tomography (X-CT) inspection, rotate-only scanner is commonly used because this configuration offers the highest imaging speed and best utilization of X-ray dose. But it requires that the imaging region of the scanned object must fit within the X-ray beam. Another configuration, transverse-rotate scanner, has a bigger field of view, but it is much more time consuming. In this paper, a two-dimensional X-CT imaging method for large objects is proposed to overcome the existing disadvantages. The scan principle of this method has been described and the reconstruction algorithm has been deduced. The results of the computer simulation and the experiments show the validity of the new method. Analysis shows that the scan field of view of this method is 1.8 times larger than that of rotate-only X-CT. The scan speed of this method is also much quicker than transverse-rotate X-CT

  20. STUDY OF AUTOMATIC IMAGE RECTIFICATION AND REGISTRATION OF SCANNED HISTORICAL AERIAL PHOTOGRAPHS

    Directory of Open Access Journals (Sweden)

    H. R. Chen

    2016-06-01

    Full Text Available Historical aerial photographs directly provide good evidences of past times. The Research Center for Humanities and Social Sciences (RCHSS of Taiwan Academia Sinica has collected and scanned numerous historical maps and aerial images of Taiwan and China. Some maps or images have been geo-referenced manually, but most of historical aerial images have not been registered since there are no GPS or IMU data for orientation assisting in the past. In our research, we developed an automatic process of matching historical aerial images by SIFT (Scale Invariant Feature Transform for handling the great quantity of images by computer vision. SIFT is one of the most popular method of image feature extracting and matching. This algorithm extracts extreme values in scale space into invariant image features, which are robust to changing in rotation scale, noise, and illumination. We also use RANSAC (Random sample consensus to remove outliers, and obtain good conjugated points between photographs. Finally, we manually add control points for registration through least square adjustment based on collinear equation. In the future, we can use image feature points of more photographs to build control image database. Every new image will be treated as query image. If feature points of query image match the features in database, it means that the query image probably is overlapped with control images.With the updating of database, more and more query image can be matched and aligned automatically. Other research about multi-time period environmental changes can be investigated with those geo-referenced temporal spatial data.

  1. Cat-Scan and nuclear magnetic resonance imaging in abnormalities of neuronal migration

    International Nuclear Information System (INIS)

    Wilms, G.; Marchal, G.; Decrop, E.; Van Hecke, P.; Baert, A.L.; Casaer, P.

    1989-01-01

    This is a report of the CAT-scan and MRI characteristics in 14 patients with anomalies of neuronal migration. There were 3 cases of heterotopia of the gray matter, 2 cases of agyria, 3 cases of pachygyria, 2 cases of schizencephaly and 4 cases of hemimegalencephaly. The primary advantages of MRI in comparison with CAT-scanning, are better contrast between the white and gray matter; better delineation of the cerebral cortex and the possibility of direct mutiplanar imaging. NMRI will become the investigation of choice in children with epilepsy or psychomotor retardation [fr

  2. Subperiosteal chondroma. Diagnostic value of CT scan imaging in two cases

    International Nuclear Information System (INIS)

    Lerais, J.M.; Auquier, F.; Baudrillard, J.C.; Durot, J.F.; Laugareil, P.; Wallays, C.; Lefort, G.; Daoud, S.; Gaillard, D.

    1988-01-01

    Results of CT scan exploration are reported in two cases of subperiosteal chondroma, one in a 4 year old child affecting the anterior tibial tuberosity the other in a 9 year old child involving the upper end of humerus. Data from CT scan imaging were undoubtedly superior to those of conventional radiography and appear to be characteristic of this benign cartilaginous tumor, greatly facilitating correlation between clinical, radiological and pathologic findings. The scanner should allow certain situations to be dedramatized and the surgical attitude adapted when the functional prognosis is involved [fr

  3. Reducing charging effects in scanning electron microscope images by Rayleigh contrast stretching method (RCS).

    Science.gov (United States)

    Wan Ismail, W Z; Sim, K S; Tso, C P; Ting, H Y

    2011-01-01

    To reduce undesirable charging effects in scanning electron microscope images, Rayleigh contrast stretching is developed and employed. First, re-scaling is performed on the input image histograms with Rayleigh algorithm. Then, contrast stretching or contrast adjustment is implemented to improve the images while reducing the contrast charging artifacts. This technique has been compared to some existing histogram equalization (HE) extension techniques: recursive sub-image HE, contrast stretching dynamic HE, multipeak HE and recursive mean separate HE. Other post processing methods, such as wavelet approach, spatial filtering, and exponential contrast stretching, are compared as well. Overall, the proposed method produces better image compensation in reducing charging artifacts. Copyright © 2011 Wiley Periodicals, Inc.

  4. Side-Scan Sonar Image Mosaic Using Couple Feature Points with Constraint of Track Line Positions

    Directory of Open Access Journals (Sweden)

    Jianhu Zhao

    2018-06-01

    Full Text Available To obtain large-scale seabed surface image, this paper proposes a side-scan sonar (SSS image mosaic method using couple feature points (CFPs with constraint of track line positions. The SSS geocoded images are firstly used to form a coarsely mosaicked one and the overlapping areas between adjacent strip images can be determined based on geographic information. Inside the overlapping areas, the feature point (FP detection and registration operation are adopted for both strips. According to the detected CFPs and track line positions, an adjustment model is established to accommodate complex local distortions as well as ensure the global stability. This proposed method effectively solves the problem of target ghosting or dislocation and no accumulated errors arise in the mosaicking process. Experimental results show that the finally mosaicked image correctly reflects the object distribution, which is meaningful for understanding and interpreting seabed topography.

  5. Image quality characteristics of a novel colour scanning digital ophthalmoscope (SDO) compared with fundus photography.

    Science.gov (United States)

    Strauss, Rupert W; Krieglstein, Tina R; Priglinger, Siegfried G; Reis, Werner; Ulbig, Michael W; Kampik, Anselm; Neubauer, Aljoscha S

    2007-11-01

    To establish a set of quality parameters for grading image quality and apply those to evaluate the fundus image quality obtained by a new scanning digital ophthalmoscope (SDO) compared with standard slide photography. On visual analogue scales a total of eight image characteristics were defined: overall quality, contrast, colour brilliance, focus (sharpness), resolution and details, noise, artefacts and validity of clinical assessment. Grading was repeated after 4 months to assess repeatability. Fundus images of 23 patients imaged digitally by SDO and by Zeiss 450FF fundus camera using Kodak film were graded side-by-side by three graders. Lens opacity was quantified with the Interzeag Lens Opacity Meter 701. For all of the eight scales of image quality, good repeatability within the graders (mean Kendall's W 0.69) was obtained after 4 months. Inter-grader agreement ranged between 0.31 and 0.66. Despite the SDO's limited nominal image resolution of 720 x 576 pixels, the Zeiss FF 450 camera performed better in only two of the subscales - noise (p = 0.001) and artefacts (p = 0.01). Lens opacities significantly influenced only the two subscales 'resolution' and 'details', which deteriorated with increasing media opacities for both imaging systems. Distinct scales to grade image characteristics of different origin were developed and validated. Overall SDO digital imaging was found to provide fundus pictures of a similarly high level of quality as expert photography on slides.

  6. A hard X-ray scanning microprobe for fluorescence imaging and microdiffraction at the Advanced Photon Source

    International Nuclear Information System (INIS)

    Cai, L.; Lai, B.; Yun, W.; Ilinski, P.; Legnini, D.; Maser, J.; Rodrigues, W.

    1999-01-01

    A hard x-ray scanning microprobe based on zone plate optics and undulator radiation, in the energy region from 6 to 20 keV, has reached a focal spot size (FWHM) of 0.15 microm (v) x 0.6 microm (h), and a photon flux of 4 x 10 9 photons/sec/0.01%BW. Using a slit 44 meters upstream to create a virtual source, a circular beam spot of 0.15 microm in diameter can be obtained with a photon flux of one order of magnitude less. During fluorescence mapping of trace elements in a single human ovarian cell, the microprobe exhibited an imaging sensitivity for Pt (L a line) of 80 attograms/microm 2 for a count rate of 10 counts per second. The x-ray microprobe has been used to map crystallographic strain and multiquantum well thickness in micro-optoelectronic devices produced with the selective area growth technique

  7. A hybrid 3D LIDAR imager based on pixel-by-pixel scanning and DS-OCDMA

    Science.gov (United States)

    Kim, Gunzung; Eom, Jeongsook; Park, Yongwan

    2016-03-01

    We propose a new hybrid 3D light detection and ranging (LIDAR) system, which measures a scene with 1280 x 600 pixels at a refresh rate of 60fps. The emitted pulses of each pixel are modulated by direct sequence optical code division multiple access (DS-OCDMA) techniques. The modulated pulses include a unique device identification number, the pixel position in the line, and a checksum. The LIDAR emits the modulated pulses periodically without waiting to receive returning light at the detector. When all the pixels are completely through the process, the travel time, amplitude, width, and speed are used by the pixel-by-pixel scanning LIDAR imager to generate point cloud data as the measured results. We programmed the entire hybrid 3D LIDAR operation in a simulator to observe the functionality accomplished by our proposed model.

  8. Towards simultaneous Talbot bands based optical coherence tomography and scanning laser ophthalmoscopy imaging.

    Science.gov (United States)

    Marques, Manuel J; Bradu, Adrian; Podoleanu, Adrian Gh

    2014-05-01

    We report a Talbot bands-based optical coherence tomography (OCT) system capable of producing longitudinal B-scan OCT images and en-face scanning laser ophthalmoscopy (SLO) images of the human retina in-vivo. The OCT channel employs a broadband optical source and a spectrometer. A gap is created between the sample and reference beams while on their way towards the spectrometer's dispersive element to create Talbot bands. The spatial separation of the two beams facilitates collection by an SLO channel of optical power originating exclusively from the retina, deprived from any contribution from the reference beam. Three different modes of operation are presented, constrained by the minimum integration time of the camera used in the spectrometer and by the galvo-scanners' scanning rate: (i) a simultaneous acquisition mode over the two channels, useful for small size imaging, that conserves the pixel-to-pixel correspondence between them; (ii) a hybrid sequential mode, where the system switches itself between the two regimes and (iii) a sequential "on-demand" mode, where the system can be used in either OCT or SLO regimes for as long as required. The two sequential modes present varying degrees of trade-off between pixel-to-pixel correspondence and independent full control of parameters within each channel. Images of the optic nerve and fovea regions obtained in the simultaneous (i) and in the hybrid sequential mode (ii) are presented.

  9. Imaging by in situ Scanning Tunnelling Microscopy and its Nanotechnological Perspectives

    DEFF Research Database (Denmark)

    Andersen, Jens Enevold Thaulov

    2002-01-01

    of the tip and working electrode. In collaboration with Danish Micro Engineering A/S, the instrument was constructed and tested in laboratory environments. The system was successfully developed, as to meet international-market requirements. Within the frame of the work, procedures of tip coating...... of simultaneous imaging and electrochemical manipulation offers unprecedented possibilities of device construction at the nanometer level. The present work is therefore intended as a promotion of in situ STM as a tool of nanotechnology that allows device fabrication of sub-nanometer tolerances. Novel applications......-biotechnology are evaluated. It is thus documented that in situ STM constitutes an indispensable tool of nanotechnology. Keywords are imaging and control. The manufacture of nanotechnological devices is exemplified by construction of a ‘nanotypewriter’ that exploits a novel feature of electrochemistry. The nanotypewriter...

  10. Non-scanning x-ray fluorescence microscope: application to real time micro-imaging

    International Nuclear Information System (INIS)

    Sakurai, K.; Eba, H.

    2000-01-01

    So far, x-ray fluorescence (XRF) micro-imaging has been performed by a 2D positional scan of a sample against a collimated beam. Obtaining information on specific elements in a nondestructive manner is an attractive prospect for many scientific applications. Furthermore, a synchrotron micro-beam can enhance the spatial resolution down to 0.1 μm. However, the total measuring time becomes quite long (a few hours to a half day), since one needs a number of scanning points in order to obtain a high-quality image. It is possible to obtain an x-ray image with 1 M pixels and with 20 μm resolution in a very short time of 20 sec - 3 min using a non-scanning XRF microscope, which is based on completely different concept. In the present report, we discuss the application of this technique to real time micro-imaging. The experiments were carried out at BL-4A, Photon Factory, Tsukuba, Japan. We employed a grazing-incidence arrangement to make primary x-rays illuminate the whole sample surface. We adopted parallel-beam optics and extremely-close-geometry in order to detect x-ray fluorescence with a CCD camera. The selective-excitation capability of tunable monochromatic synchrotron radiation is a feasible method for distinguishing the elements of interest. One can obtain an image of each element by differentiating the images obtained above and below the absorption edges of interest. The growth of metallic dendrites from a solution dropped on a substrate was studied successfully. Several different growth patterns, corresponding to concentration and other conditions for diffusion, were observed as x-ray images. Since the present technique requires only 40 sec for each shot, it is possible to record a growing process through repeated exposures like a movie. The authors would like to thank Prof. A. Iida (Photon Factory) for his valuable comments. (author)

  11. Optically trapped atomic resonant devices for narrow linewidth spectral imaging

    Science.gov (United States)

    Qian, Lipeng

    This thesis focuses on the development of atomic resonant devices for spectroscopic applications. The primary emphasis is on the imaging properties of optically thick atomic resonant fluorescent filters and their applications. In addition, this thesis presents a new concept for producing very narrow linewidth light as from an atomic vapor lamp pumped by a nanosecond pulse system. This research was motivated by application for missile warning system, and presents an innovative approach to a wide angle, ultra narrow linewidth imaging filter using a potassium vapor cell. The approach is to image onto and collect the fluorescent photons emitted from the surface of an optically thick potassium vapor cell, generating a 2 GHz pass-band imaging filter. This linewidth is narrow enough to fall within a Fraunhefer dark zone in the solar spectrum, thus make the detection solar blind. Experiments are conducted to measure the absorption line shape of the potassium resonant filter, the quantum efficiency of the fluorescent behavior, and the resolution of the fluorescent image. Fluorescent images with different spatial frequency components are analyzed by using a discrete Fourier transform, and the imaging capability of the fluorescent filter is described by its Modulation Transfer Function. For the detection of radiation that is spectrally broader than the linewidth of the potassium imaging filter, the fluorescent image is seen to be blurred by diffuse fluorescence from the slightly off resonant photons. To correct this, an ultra-thin potassium imaging filter is developed and characterized. The imaging property of the ultra-thin potassium imaging cell is tested with a potassium seeded flame, yielding a resolution image of ˜ 20 lines per mm. The physics behind the atomic resonant fluorescent filter is radiation trapping. The diffusion process of the resonant photons trapped in the atomic vapor is theoretically described in this thesis. A Monte Carlo method is used to simulate the

  12. Improved image quality of cone beam CT scans for radiotherapy image guidance using fiber-interspaced antiscatter grid.

    Science.gov (United States)

    Stankovic, Uros; van Herk, Marcel; Ploeger, Lennert S; Sonke, Jan-Jakob

    2014-06-01

    Medical linear accelerator mounted cone beam CT (CBCT) scanner provides useful soft tissue contrast for purposes of image guidance in radiotherapy. The presence of extensive scattered radiation has a negative effect on soft tissue visibility and uniformity of CBCT scans. Antiscatter grids (ASG) are used in the field of diagnostic radiography to mitigate the scatter. They usually do increase the contrast of the scan, but simultaneously increase the noise. Therefore, and considering other scatter mitigation mechanisms present in a CBCT scanner, the applicability of ASGs with aluminum interspacing for a wide range of imaging conditions has been inconclusive in previous studies. In recent years, grids using fiber interspacers have appeared, providing grids with higher scatter rejection while maintaining reasonable transmission of primary radiation. The purpose of this study was to evaluate the impact of one such grid on CBCT image quality. The grid used (Philips Medical Systems) had ratio of 21:1, frequency 36 lp/cm, and nominal selectivity of 11.9. It was mounted on the kV flat panel detector of an Elekta Synergy linear accelerator and tested in a phantom and a clinical study. Due to the flex of the linac and presence of gridline artifacts an angle dependent gain correction algorithm was devised to mitigate resulting artifacts. Scan reconstruction was performed using XVI4.5 augmented with inhouse developed image lag correction and Hounsfield unit calibration. To determine the necessary parameters for Hounsfield unit calibration and software scatter correction parameters, the Catphan 600 (The Phantom Laboratory) phantom was used. Image quality parameters were evaluated using CIRS CBCT Image Quality and Electron Density Phantom (CIRS) in two different geometries: one modeling head and neck and other pelvic region. Phantoms were acquired with and without the grid and reconstructed with and without software correction which was adapted for the different acquisition

  13. Improved image quality of cone beam CT scans for radiotherapy image guidance using fiber-interspaced antiscatter grid

    International Nuclear Information System (INIS)

    Stankovic, Uros; Herk, Marcel van; Ploeger, Lennert S.; Sonke, Jan-Jakob

    2014-01-01

    Purpose: Medical linear accelerator mounted cone beam CT (CBCT) scanner provides useful soft tissue contrast for purposes of image guidance in radiotherapy. The presence of extensive scattered radiation has a negative effect on soft tissue visibility and uniformity of CBCT scans. Antiscatter grids (ASG) are used in the field of diagnostic radiography to mitigate the scatter. They usually do increase the contrast of the scan, but simultaneously increase the noise. Therefore, and considering other scatter mitigation mechanisms present in a CBCT scanner, the applicability of ASGs with aluminum interspacing for a wide range of imaging conditions has been inconclusive in previous studies. In recent years, grids using fiber interspacers have appeared, providing grids with higher scatter rejection while maintaining reasonable transmission of primary radiation. The purpose of this study was to evaluate the impact of one such grid on CBCT image quality. Methods: The grid used (Philips Medical Systems) had ratio of 21:1, frequency 36 lp/cm, and nominal selectivity of 11.9. It was mounted on the kV flat panel detector of an Elekta Synergy linear accelerator and tested in a phantom and a clinical study. Due to the flex of the linac and presence of gridline artifacts an angle dependent gain correction algorithm was devised to mitigate resulting artifacts. Scan reconstruction was performed using XVI4.5 augmented with inhouse developed image lag correction and Hounsfield unit calibration. To determine the necessary parameters for Hounsfield unit calibration and software scatter correction parameters, the Catphan 600 (The Phantom Laboratory) phantom was used. Image quality parameters were evaluated using CIRS CBCT Image Quality and Electron Density Phantom (CIRS) in two different geometries: one modeling head and neck and other pelvic region. Phantoms were acquired with and without the grid and reconstructed with and without software correction which was adapted for the different

  14. Hip fracture discrimination by the Achilles Insight QUS imaging device

    International Nuclear Information System (INIS)

    Damilakis, John; Papadokostakis, George; Perisinakis, Kostas; Maris, Thomas G.; Karantanas, Apostolos H.

    2007-01-01

    The importance of osteoporosis as a major health problem is well recognized. Its major clinical manifestation is low energy fractures. Considerable effort has been directed towards search of noninvasive methods for assessing osteoporotic fracture risk. The aim of this study was to evaluate the ability of quantitative ultrasound (QUS) variables measured by a new heel QUS imaging device to discriminate between postmenopausal women with and without hip fracture. The subjects included 30 postmenopausal female patients with hip fracture and 30 age-matched healthy women. Measurements were acquired using the Achilles Insight QUS imaging device. Bone mineral density (BMD) measurements were carried out using the Lunar Prodigy DXA scanner. Achilles Insight provides images of the heel bone and measures broadband ultrasound attenuation (BUA) and speed of sound (SOS) values in a circular region of interest. A third QUS variable, the stiffness index (SI) was also determined. The short-term precision for healthy subjects was 2.05%, 0.17% and 1.91% for BUA, SOS and SI, respectively. Corresponding values for patients with fractures were 1.80%, 0.16% and 2.04%. All QUS variables measured using the Achilles Insight were significant discriminators of hip fractures (area under ROC curve = 0.77, 0.74 and 0.77 for BUA, SOS and SI, respectively). BMD measurements of the hip had the greatest discriminatory ability (area under ROC curve = 0.88). Statistically significant differences were found between the area under the ROC curve of BMD and the corresponding curves of the QUS variables (P < 0.05 for each of the three comparisons). QUS variables measured by Achilles Insight can be expected to be useful as indicators of the risk of hip fracture in postmenopausal women

  15. Efficient Imaging and Real-Time Display of Scanning Ion Conductance Microscopy Based on Block Compressive Sensing

    Science.gov (United States)

    Li, Gongxin; Li, Peng; Wang, Yuechao; Wang, Wenxue; Xi, Ning; Liu, Lianqing

    2014-07-01

    Scanning Ion Conductance Microscopy (SICM) is one kind of Scanning Probe Microscopies (SPMs), and it is widely used in imaging soft samples for many distinctive advantages. However, the scanning speed of SICM is much slower than other SPMs. Compressive sensing (CS) could improve scanning speed tremendously by breaking through the Shannon sampling theorem, but it still requires too much time in image reconstruction. Block compressive sensing can be applied to SICM imaging to further reduce the reconstruction time of sparse signals, and it has another unique application that it can achieve the function of image real-time display in SICM imaging. In this article, a new method of dividing blocks and a new matrix arithmetic operation were proposed to build the block compressive sensing model, and several experiments were carried out to verify the superiority of block compressive sensing in reducing imaging time and real-time display in SICM imaging.

  16. Scan direction induced charging dynamics and the application for detection of gate to S/D shorts in logic devices

    Science.gov (United States)

    Lei, Ming; Tian, Qing; Wu, Kevin; Zhao, Yan

    2016-03-01

    Gate to source/drain (S/D) short is the most common and detrimental failure mechanism for advanced process technology development in Metal-Oxide-Semiconductor-Field-Effect-Transistor (MOSFET) device manufacturing. Especially for sub-1Xnm nodes, MOSFET device is more vulnerable to gate-S/D shorts due to the aggressive scaling. The detection of this kind of electrical short defect is always challenging for in-line electron beam inspection (EBI), especially new shorting mechanisms on atomic scale due to new material/process flow implementation. The second challenge comes from the characterization of the shorts including identification of the exact shorting location. In this paper, we demonstrate unique scan direction induced charging dynamics (SDCD) phenomenon which stems from the transistor level response from EBI scan at post metal contact chemical-mechanical planarization (CMP) layers. We found that SDCD effect is exceptionally useful for gate-S/D short induced voltage contrast (VC) defect detection, especially for identification of shorting locations. The unique SDCD effect signatures of gate-S/D shorts can be used as fingerprint for ground true shorting defect detection. Correlation with other characterization methods on the same defective location from EBI scan shows consistent results from various shorting mechanism. A practical work flow to implement the application of SDCD effect for in-line EBI monitor of critical gate-S/D short defects is also proposed, together with examples of successful application use cases which mostly focus on static random-access memory (SRAM) array regions. Although the capability of gate-S/D short detection as well as expected device response is limited to passing transistors and pull-down transistors due to the design restriction from standard 6-cell SRAM structure, SDCD effect is proven to be very effective for gate-S/D short induced VC defect detection as well as yield learning for advanced technology development.

  17. Surface scanning through a cylindrical tank of coupling fluid for clinical microwave breast imaging exams

    International Nuclear Information System (INIS)

    Pallone, Matthew J.; Meaney, Paul M.; Paulsen, Keith D.

    2012-01-01

    Purpose: Microwave tomographic image quality can be improved significantly with prior knowledge of the breast surface geometry. The authors have developed a novel laser scanning system capable of accurately recovering surface renderings of breast-shaped phantoms immersed within a cylindrical tank of coupling fluid which resides completely external to the tank (and the aqueous environment) and overcomes the challenges associated with the optical distortions caused by refraction from the air, tank wall, and liquid bath interfaces. Methods: The scanner utilizes two laser line generators and a small CCD camera mounted concentrically on a rotating gantry about the microwave imaging tank. Various calibration methods were considered for optimizing the accuracy of the scanner in the presence of the optical distortions including traditional ray tracing and image registration approaches. In this paper, the authors describe the construction and operation of the laser scanner, compare the efficacy of several calibration methods—including analytical ray tracing and piecewise linear, polynomial, locally weighted mean, and thin-plate-spline (TPS) image registrations—and report outcomes from preliminary phantom experiments. Results: The results show that errors in calibrating camera angles and position prevented analytical ray tracing from achieving submillimeter accuracy in the surface renderings obtained from our scanner configuration. Conversely, calibration by image registration reliably attained mean surface errors of less than 0.5 mm depending on the geometric complexity of the object scanned. While each of the image registration approaches outperformed the ray tracing strategy, the authors found global polynomial methods produced the best compromise between average surface error and scanner robustness. Conclusions: The laser scanning system provides a fast and accurate method of three dimensional surface capture in the aqueous environment commonly found in microwave

  18. PAVEMENT DISTRESS DETECTION WITH PICUCHA METHODOLOGY FOR AREA-SCAN CAMERAS AND DARK IMAGES

    Directory of Open Access Journals (Sweden)

    Reus Salini

    2017-04-01

    Full Text Available The PICture Unsupervised Classification with Human Analysis (PICUCHA refers to a hybrid human-artificial intelligence methodology for pavement distresses assessment. It combines the human flexibility to recognize patterns and features in images with the neural network ability to expand such recognition to large volumes of images. In this study, the PICUCHA performance was tested with images taken with area-scan cameras and flash light illumination over a pavement with dark textures. These images are particularly challenging for the analysis because of the lens distortion and non-homogeneous illumination, generating artificial joints that happened at random positions inside the image cells. The chosen images were previously analyzed by other software without success because of the dark coluor. The PICUCHA algorithms could analyze the images with no noticeable problem and without any image pre-processing, such as contrast or brightness adjustments. Because of the special procedure used by the pavement engineer for the key patterns description, the distresses detection accuracy of the PICUCHA for the particular image set could reach 100%.

  19. RF Device for Acquiring Images of the Human Body

    Science.gov (United States)

    Gaier, Todd C.; McGrath, William R.

    2010-01-01

    data set into a three-dimensional image in a matter of seconds. The innovation is to configure the receiver array in a ring topology surrounding the scanned object. The ring is then scanned vertically to cover the necessary two-dimensional surface. This fabrication of the ring is made possible by using planar antenna and circuit technology. A planar circuit board serves as a medium for both antennas and signal processing components. Using this technique, parts counts are kept low, and the cost per element is a small fraction of a waveguide-based system.

  20. Automatic analysis of image quality control for Image Guided Radiation Therapy (IGRT) devices in external radiotherapy

    International Nuclear Information System (INIS)

    Torfeh, Tarraf

    2009-01-01

    On-board imagers mounted on a radiotherapy treatment machine are very effective devices that improve the geometric accuracy of radiation delivery. However, a precise and regular quality control program is required in order to achieve this objective. Our purpose consisted of developing software tools dedicated to an automatic image quality control of IGRT devices used in external radiotherapy: 2D-MV mode for measuring patient position during the treatment using high energy images, 2D-kV mode (low energy images) and 3D Cone Beam Computed Tomography (CBCT) MV or kV mode, used for patient positioning before treatment. Automated analysis of the Winston and Lutz test was also proposed. This test is used for the evaluation of the mechanical aspects of treatment machines on which additional constraints are carried out due to the on-board imagers additional weights. Finally, a technique of generating digital phantoms in order to assess the performance of the proposed software tools is described. Software tools dedicated to an automatic quality control of IGRT devices allow reducing by a factor of 100 the time spent by the medical physics team to analyze the results of controls while improving their accuracy by using objective and reproducible analysis and offering traceability through generating automatic monitoring reports and statistical studies. (author) [fr

  1. Observation of meander pattern in signals from superconducting MgB{sub 2} detector by scanning pulsed laser imaging

    Energy Technology Data Exchange (ETDEWEB)

    Ishida, Takekazu, E-mail: ishida@center.osakafu-u.ac.jp [Department of Physics and Electronics, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531 (Japan); Institute for Nanofabrication Research, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531 (Japan); Yagi, Ikutaro; Yoshioka, Naohito; Huy, Ho Thanh [Department of Physics and Electronics, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531 (Japan); Yotsuya, Tsutomu [Institute for Nanofabrication Research, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531 (Japan); Nanoscience and Nanotechnology Research Center, Osaka Prefecture University, 2-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8570 (Japan); Shimakage, Hisashi [Department of Electrical and Electronic Engineering, College of Engineering, 4-12-1, Nakanarusawa, Hitachi, Ibaraki 316-8511 (Japan); Miki, Shigehito [Kansai Advanced Research Center, National Institute of Information and Communications Technology, 588-2 Iwaoka-cho, Nishi-ku, Kobe, Hyogo 651-2429 (Japan); Wang, Zhen [Institute for Nanofabrication Research, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531 (Japan); Kansai Advanced Research Center, National Institute of Information and Communications Technology, 588-2 Iwaoka-cho, Nishi-ku, Kobe, Hyogo 651-2429 (Japan)

    2013-01-15

    Highlights: ► We fabricate a superconducting MgB{sub 2} meander detector as a solid-state neutron detector. ► MgB{sub 2} detector uses XYZ stage, optical fiber and focused lens to scan as a microscope. ► The 6 μm line-and-space in meandering pattern can be resolved in signals against pulsed laser. -- Abstract: Superconducting MgB{sub 2} meander detector has been imaged by scanning a spot of 1.5-μm focused pulsed laser. The superconducting detector using high-quality {sup 10}B-enriched MgB{sub 2} thin films at higher operating temperatures has been fabricated to utilize a resistance change induced by the nuclear energy of {sup 10}B and neutron. The MgB{sub 2} detector consists of a 200-nm-thick MgB{sub 2} thin-film meander line, a 300-nm-thick SiO protective layer, and 150-nm-thick Nb electrodes with 1-μm MgB{sub 2} wires. The devices were placed in a 4 K refrigerator to control at a certain temperature below T{sub c}. A scanning laser spot can be used by the combination of the XYZ piezo-drive stage and an optical fibre with an aspheric focused lens. The measurement system is fully controlled by LabVIEW based software. We succeeded in observing a line-and-space image of a meandering pattern by analysing response signals.

  2. Image guided placement of temporary anchorage devices for tooth movement

    Energy Technology Data Exchange (ETDEWEB)

    Bahl-Palomo, L.; Bissada, N. [Case Western Reserve Univ. School of Dental Medicine, Dept. of Periodontics, Cleveland, OH (United States); Palomo, J.M.; Hans, M.G. [Case Western Reserve Univ. School of Dental Medicine, Dept. of Orthodontics, Cleveland, OH (United States)

    2007-06-15

    The aim of this project is to develop an image guided protocol for placement of a temporary anchorage device without surgically reflecting a mucoperiosteal flap. Eighteen orthodontic cases were selected for skeletal anchorage from the department of orthodontics at Case University. CBCT images of the subjects were taken using the Hitachi CB MercuRay system set at 15 mA, 120 kVp. CBCT images evaluated the ideal location for TAD placement in three dimensions. Horizontal and vertical linear measurements were taken from fixed dental landmarks to clearly define the location for placement. Transverse slices were used to evaluate the thickness of the buccal plate. Using the transverse view, the angle of insertion was determined such that the maximum buccal plate surface area would contact the screw. TADs were placed in the optimum location, with the most appropriate angle of insertion using a closed approach and with minimal local anesthesia and without flap elevation. Results: All TADs were placed without anatomic encroachment and enabled fixed orthodontic anchorage. (orig.)

  3. Image guided placement of temporary anchorage devices for tooth movement

    International Nuclear Information System (INIS)

    Bahl-Palomo, L.; Bissada, N.; Palomo, J.M.; Hans, M.G.

    2007-01-01

    The aim of this project is to develop an image guided protocol for placement of a temporary anchorage device without surgically reflecting a mucoperiosteal flap. Eighteen orthodontic cases were selected for skeletal anchorage from the department of orthodontics at Case University. CBCT images of the subjects were taken using the Hitachi CB MercuRay system set at 15 mA, 120 kVp. CBCT images evaluated the ideal location for TAD placement in three dimensions. Horizontal and vertical linear measurements were taken from fixed dental landmarks to clearly define the location for placement. Transverse slices were used to evaluate the thickness of the buccal plate. Using the transverse view, the angle of insertion was determined such that the maximum buccal plate surface area would contact the screw. TADs were placed in the optimum location, with the most appropriate angle of insertion using a closed approach and with minimal local anesthesia and without flap elevation. Results: All TADs were placed without anatomic encroachment and enabled fixed orthodontic anchorage. (orig.)

  4. Multidirectional Scanning Model, MUSCLE, to Vectorize Raster Images with Straight Lines

    Directory of Open Access Journals (Sweden)

    Ibrahim Baz

    2008-04-01

    Full Text Available This paper presents a new model, MUSCLE (Multidirectional Scanning for Line Extraction, for automatic vectorization of raster images with straight lines. The algorithm of the model implements the line thinning and the simple neighborhood methods to perform vectorization. The model allows users to define specified criteria which are crucial for acquiring the vectorization process. In this model, various raster images can be vectorized such as township plans, maps, architectural drawings, and machine plans. The algorithm of the model was developed by implementing an appropriate computer programming and tested on a basic application. Results, verified by using two well known vectorization programs (WinTopo and Scan2CAD, indicated that the model can successfully vectorize the specified raster data quickly and accurately.

  5. Gastric visualization and image quality in radionuclide bone scanning: concise communication

    International Nuclear Information System (INIS)

    Wilson, M.A.; Pollack, M.J.

    1981-01-01

    In a 12-mo study period, there were 14 days identified when the stomach was visualized in routine bone imaging. On these days, 44% of the 110 patients imaged demonstrated this effect. Only the quality control, binding efficiency, and scan quality differed (p less than 0.005) when the study population was compared with a reference population of 162 patients. However, on the days when this effect was noted, there was a significant (p less than 0.001) linear correlation between the presence and degree of gastric visualization and the radiopharmaceutical incubation and quality control parameters. The study suggests a sporadic phenomenon that appears to result from partial oxidation of the agent during incubation, producing (a) different species of labeled diphosphonate that display altered affinity for bone (scan quality) and (b) free pertechnetate

  6. Collagen imaged by Coherent X-ray Diffraction: towards a complementary tool to conventional scanning SAXS

    International Nuclear Information System (INIS)

    Berenguer de la Cuesta, Felisa; Bean, Richard J; Bozec, Laurent; Robinson, Ian K; McCallion, Catriona; Wallace, Kris; Hiller, Jen C; Terrill, Nicholas J

    2010-01-01

    Third generation x-ray sources offer unique possibilities for exploiting coherence in the study of materials. New insights in the structure and dynamics of soft condensed matter and biological samples can be obtained by coherent x-ray diffraction (CXD). However, the experimental procedures for applying these methods to collagen tissues are still under development. We present here an investigation for the optimal procedure in order to obtain high quality CXD data from collagen tissues. Sample handling and preparation and adequate coherence defining apertures are among the more relevant factors to take into account. The impact of the results is also discussed, in particular in comparison with the information that can be extracted from conventional scanning small angle x-ray scattering (SAXS). Images of collagen tissues obtained by CXD reconstructions will give additional information about the local structure with higher resolution and will complement scanning SAXS images.

  7. Collagen imaged by Coherent X-ray Diffraction: towards a complementary tool to conventional scanning SAXS

    Energy Technology Data Exchange (ETDEWEB)

    Berenguer de la Cuesta, Felisa; Bean, Richard J; Bozec, Laurent; Robinson, Ian K [London Centre for Nanotechnology (LCN), University College London (UCL), London WC1H 0AH (United Kingdom); McCallion, Catriona; Wallace, Kris [Department of Physics and Astronomy, University College London (UCL), London WC1E 6BT (United Kingdom); Hiller, Jen C; Terrill, Nicholas J, E-mail: f.berenguer@ucl.ac.u [Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE (United Kingdom)

    2010-10-01

    Third generation x-ray sources offer unique possibilities for exploiting coherence in the study of materials. New insights in the structure and dynamics of soft condensed matter and biological samples can be obtained by coherent x-ray diffraction (CXD). However, the experimental procedures for applying these methods to collagen tissues are still under development. We present here an investigation for the optimal procedure in order to obtain high quality CXD data from collagen tissues. Sample handling and preparation and adequate coherence defining apertures are among the more relevant factors to take into account. The impact of the results is also discussed, in particular in comparison with the information that can be extracted from conventional scanning small angle x-ray scattering (SAXS). Images of collagen tissues obtained by CXD reconstructions will give additional information about the local structure with higher resolution and will complement scanning SAXS images.

  8. Assessment of image quality in x-ray radiography imaging using a small plasma focus device

    International Nuclear Information System (INIS)

    Kanani, A.; Shirani, B.; Jabbari, I.; Mokhtari, J.

    2014-01-01

    This paper offers a comprehensive investigation of image quality parameters for a small plasma focus as a pulsed hard x-ray source for radiography applications. A set of images were captured from some metal objects and electronic circuits using a low energy plasma focus at different voltages of capacitor bank and different pressures of argon gas. The x-ray source focal spot of this device was obtained to be about 0.6 mm using the penumbra imaging method. The image quality was studied by several parameters such as image contrast, line spread function (LSF) and modulation transfer function (MTF). Results showed that the contrast changes by variations in gas pressure. The best contrast was obtained at a pressure of 0.5 mbar and 3.75 kJ stored energy. The results of x-ray dose from the device showed that about 0.6 mGy is sufficient to obtain acceptable images on the film. The measurements of LSF and MTF parameters were carried out by means of a thin stainless steel wire 0.8 mm in diameter and the cut-off frequency was obtained to be about 1.5 cycles/mm. - Highlights: • We investigated a small plasma focus as pulsed x-ray source for radiography applications. • The image quality was studied by several parameters such as image contrast, LSF and MTF. • The x-ray source focal spot was obtained to be ∼0.6 mm using the penumbra imaging method. • The x-ray dose measurement showed that about 0.6 mGy is sufficient to obtain acceptable images on the film. • The profiles of LSF and MTF showed that the cut-off frequency is about 1.5 cycles/mm

  9. Procedure for physicist's scanning in the image processing system of bubble chambers

    International Nuclear Information System (INIS)

    Gritsaenko, I.A.; Petrovykh, L.P.; Petrovykh, Yu.L.; Fenyuk, A.B.

    1984-01-01

    The algorithm of the program of physicist's scanning for data processing from photo images in experiments using bubble chambers is described. The program allows one to perform sorting or selection of specific events for subsequent processing and identification of separate particles by bubble density along the track or by the character of the decay. The fraction of protons separated automatically constituted 97%. The program has been used for processing 50 thousand events at the BEBC chamber

  10. RGB color coded images in scanning electron microscopy of biological surfaces

    Czech Academy of Sciences Publication Activity Database

    Kofroňová, Olga; Benada, Oldřich

    2017-01-01

    Roč. 61, č. 3 (2017), s. 349-352 ISSN 0001-723X R&D Projects: GA MŠk(CZ) LO1509; GA ČR(CZ) GA16-20229S Institutional support: RVO:61388971 Keywords : Biological surfaces * Color image s * Scanning electron microscopy Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 0.673, year: 2016

  11. Development of fast parallel multi-technique scanning X-ray imaging at Synchrotron Soleil

    Science.gov (United States)

    Medjoubi, K.; Leclercq, N.; Langlois, F.; Buteau, A.; Lé, S.; Poirier, S.; Mercère, P.; Kewish, C. M.; Somogyi, A.

    2013-10-01

    A fast multimodal scanning X-ray imaging scheme is prototyped at Soleil Synchrotron. It permits the simultaneous acquisition of complementary information on the sample structure, composition and chemistry by measuring transmission, differential phase contrast, small-angle scattering, and X-ray fluorescence by dedicated detectors with ms dwell time per pixel. The results of the proof of principle experiments are presented in this paper.

  12. Automated Detection of Healthy and Diseased Aortae from Images Obtained by Contrast-Enhanced CT Scan

    Directory of Open Access Journals (Sweden)

    Michael Gayhart

    2013-01-01

    Full Text Available Purpose. We developed the next stage of our computer assisted diagnosis (CAD system to aid radiologists in evaluating CT images for aortic disease by removing innocuous images and highlighting signs of aortic disease. Materials and Methods. Segmented data of patient’s contrast-enhanced CT scan was analyzed for aortic dissection and penetrating aortic ulcer (PAU. Aortic dissection was detected by checking for an abnormal shape of the aorta using edge oriented methods. PAU was recognized through abnormally high intensities with interest point operators. Results. The aortic dissection detection process had a sensitivity of 0.8218 and a specificity of 0.9907. The PAU detection process scored a sensitivity of 0.7587 and a specificity of 0.9700. Conclusion. The aortic dissection detection process and the PAU detection process were successful in removing innocuous images, but additional methods are necessary for improving recognition of images with aortic disease.

  13. Resolution doubling in fluorescence microscopy with confocal spinning-disk image scanning microscopy.

    Science.gov (United States)

    Schulz, Olaf; Pieper, Christoph; Clever, Michaela; Pfaff, Janine; Ruhlandt, Aike; Kehlenbach, Ralph H; Wouters, Fred S; Großhans, Jörg; Bunt, Gertrude; Enderlein, Jörg

    2013-12-24

    We demonstrate how a conventional confocal spinning-disk (CSD) microscope can be converted into a doubly resolving image scanning microscopy (ISM) system without changing any part of its optical or mechanical elements. Making use of the intrinsic properties of a CSD microscope, we illuminate stroboscopically, generating an array of excitation foci that are moved across the sample by varying the phase between stroboscopic excitation and rotation of the spinning disk. ISM then generates an image with nearly doubled resolution. Using conventional fluorophores, we have imaged single nuclear pore complexes in the nuclear membrane and aggregates of GFP-conjugated Tau protein in three dimensions. Multicolor ISM was shown on cytoskeletal-associated structural proteins and on 3D four-color images including MitoTracker and Hoechst staining. The simple adaptation of conventional CSD equipment allows superresolution investigations of a broad variety of cell biological questions.

  14. Gastric visualization and image quality in radionuclide bone scanning: concise communication

    International Nuclear Information System (INIS)

    Wilson, M.A.; Pollack, M.J.

    1981-01-01

    In a 12-mo study period, there were 14 days identified when the stomach was visualized in routine bone imaging. On these days, 44% of the 110 patients imaged demonstrated this effect. There was a significant linear correlation between the presence and degree of gastric visualization and the radiopharmaceutical incubation and quality control parameters. The study suggests a sporadic phenomenon that appears to result from partial oxidation of the agent during incubation, producing (a) different species of labeled diphosphonate that display altered affinity for bone (scan quality) and (b) free pertechnetate

  15. Cancer cell imaging by stable wet near-field scanning optical microscope with resonance tracking method

    International Nuclear Information System (INIS)

    Park, Kyoung-Duck; Park, Doo-Jae; Jeong, Mun-Seok; Choi, Geun-Chang; Lee, Seung-Gol; Byeon, Clare-Chisu; Choi, Soo-Bong

    2014-01-01

    We report on a successful topographical and optical imaging of various cancer cells in liquid and in air by using a stable wet near-field scanning optical microscope that utilizes a resonance tracking method. We observed a clear dehydration which gives rise to a decrease in the cell volume down to 51%. In addition, a micro-ball lens effect due to the round-shaped young cancer cells was observed from near-field imaging, where the refractive index of young cancer cells was deduced.

  16. Cancer cell imaging by stable wet near-field scanning optical microscope with resonance tracking method

    Energy Technology Data Exchange (ETDEWEB)

    Park, Kyoung-Duck [Sungkyunkwan University, Suwon (Korea, Republic of); Inha University, Incheon (Korea, Republic of); Park, Doo-Jae; Jeong, Mun-Seok [Sungkyunkwan University, Suwon (Korea, Republic of); Choi, Geun-Chang [Seoul National University, Seoul (Korea, Republic of); Lee, Seung-Gol [Inha University, Incheon (Korea, Republic of); Byeon, Clare-Chisu [Kyungpook National University, Daegu (Korea, Republic of); Choi, Soo-Bong [Incheon National University, Incheon (Korea, Republic of)

    2014-05-15

    We report on a successful topographical and optical imaging of various cancer cells in liquid and in air by using a stable wet near-field scanning optical microscope that utilizes a resonance tracking method. We observed a clear dehydration which gives rise to a decrease in the cell volume down to 51%. In addition, a micro-ball lens effect due to the round-shaped young cancer cells was observed from near-field imaging, where the refractive index of young cancer cells was deduced.

  17. Parallel scan hyperspectral fluorescence imaging system and biomedical application for microarrays

    International Nuclear Information System (INIS)

    Liu Zhiyi; Ma Suihua; Liu Le; Guo Jihua; He Yonghong; Ji Yanhong

    2011-01-01

    Microarray research offers great potential for analysis of gene expression profile and leads to greatly improved experimental throughput. A number of instruments have been reported for microarray detection, such as chemiluminescence, surface plasmon resonance, and fluorescence markers. Fluorescence imaging is popular for the readout of microarrays. In this paper we develop a quasi-confocal, multichannel parallel scan hyperspectral fluorescence imaging system for microarray research. Hyperspectral imaging records the entire emission spectrum for every voxel within the imaged area in contrast to recording only fluorescence intensities of filter-based scanners. Coupled with data analysis, the recorded spectral information allows for quantitative identification of the contributions of multiple, spectrally overlapping fluorescent dyes and elimination of unwanted artifacts. The mechanism of quasi-confocal imaging provides a high signal-to-noise ratio, and parallel scan makes this approach a high throughput technique for microarray analysis. This system is improved with a specifically designed spectrometer which can offer a spectral resolution of 0.2 nm, and operates with spatial resolutions ranging from 2 to 30 μm . Finally, the application of the system is demonstrated by reading out microarrays for identification of bacteria.

  18. Large Scale Textured Mesh Reconstruction from Mobile Mapping Images and LIDAR Scans

    Science.gov (United States)

    Boussaha, M.; Vallet, B.; Rives, P.

    2018-05-01

    The representation of 3D geometric and photometric information of the real world is one of the most challenging and extensively studied research topics in the photogrammetry and robotics communities. In this paper, we present a fully automatic framework for 3D high quality large scale urban texture mapping using oriented images and LiDAR scans acquired by a terrestrial Mobile Mapping System (MMS). First, the acquired points and images are sliced into temporal chunks ensuring a reasonable size and time consistency between geometry (points) and photometry (images). Then, a simple, fast and scalable 3D surface reconstruction relying on the sensor space topology is performed on each chunk after an isotropic sampling of the point cloud obtained from the raw LiDAR scans. Finally, the algorithm proposed in (Waechter et al., 2014) is adapted to texture the reconstructed surface with the images acquired simultaneously, ensuring a high quality texture with no seams and global color adjustment. We evaluate our full pipeline on a dataset of 17 km of acquisition in Rouen, France resulting in nearly 2 billion points and 40000 full HD images. We are able to reconstruct and texture the whole acquisition in less than 30 computing hours, the entire process being highly parallel as each chunk can be processed independently in a separate thread or computer.

  19. LARGE SCALE TEXTURED MESH RECONSTRUCTION FROM MOBILE MAPPING IMAGES AND LIDAR SCANS

    Directory of Open Access Journals (Sweden)

    M. Boussaha

    2018-05-01

    Full Text Available The representation of 3D geometric and photometric information of the real world is one of the most challenging and extensively studied research topics in the photogrammetry and robotics communities. In this paper, we present a fully automatic framework for 3D high quality large scale urban texture mapping using oriented images and LiDAR scans acquired by a terrestrial Mobile Mapping System (MMS. First, the acquired points and images are sliced into temporal chunks ensuring a reasonable size and time consistency between geometry (points and photometry (images. Then, a simple, fast and scalable 3D surface reconstruction relying on the sensor space topology is performed on each chunk after an isotropic sampling of the point cloud obtained from the raw LiDAR scans. Finally, the algorithm proposed in (Waechter et al., 2014 is adapted to texture the reconstructed surface with the images acquired simultaneously, ensuring a high quality texture with no seams and global color adjustment. We evaluate our full pipeline on a dataset of 17 km of acquisition in Rouen, France resulting in nearly 2 billion points and 40000 full HD images. We are able to reconstruct and texture the whole acquisition in less than 30 computing hours, the entire process being highly parallel as each chunk can be processed independently in a separate thread or computer.

  20. Spin-filter scanning tunneling microscopy : a novel technique for the analysis of spin polarization on magnetic surfaces and spintronic devices

    NARCIS (Netherlands)

    Vera Marun, I.J.

    2010-01-01

    This thesis deals with the development of a versatile technique to measure spin polarization with atomic resolution. A microscopy technique that can measure electronic spin polarization is relevant for characterization of magnetic nanostructures and spintronic devices. Scanning tunneling microscopy

  1. D Model of AL Zubarah Fortress in Qatar - Terrestrial Laser Scanning VS. Dense Image Matching

    Science.gov (United States)

    Kersten, T.; Mechelke, K.; Maziull, L.

    2015-02-01

    In September 2011 the fortress Al Zubarah, built in 1938 as a typical Arabic fortress and restored in 1987 as a museum, was recorded by the HafenCity University Hamburg using terrestrial laser scanning with the IMAGER 5006h and digital photogrammetry for the Qatar Museum Authority within the framework of the Qatar Islamic Archaeology and Heritage Project. One goal of the object recording was to provide detailed 2D/3D documentation of the fortress. This was used to complete specific detailed restoration work in the recent years. From the registered laser scanning point clouds several cuttings and 2D plans were generated as well as a 3D surface model by triangle meshing. Additionally, point clouds and surface models were automatically generated from digital imagery from a Nikon D70 using the open-source software Bundler/PMVS2, free software VisualSFM, Autodesk Web Service 123D Catch beta, and low-cost software Agisoft PhotoScan. These outputs were compared with the results from terrestrial laser scanning. The point clouds and surface models derived from imagery could not achieve the same quality of geometrical accuracy as laser scanning (i.e. 1-2 cm).

  2. Image quality and stability of image-guided radiotherapy (IGRT) devices: A comparative study

    International Nuclear Information System (INIS)

    Stock, Markus; Pasler, Marlies; Birkfellner, Wolfgang; Homolka, Peter; Poetter, Richard; Georg, Dietmar

    2009-01-01

    Introduction: Our aim was to implement standards for quality assurance of IGRT devices used in our department and to compare their performances with that of a CT simulator. Materials and methods: We investigated image quality parameters for three devices over a period of 16 months. A multislice CT was used as a benchmark and results related to noise, spatial resolution, low contrast visibility (LCV) and uniformity were compared with a cone beam CT (CBCT) at a linac and simulator. Results: All devices performed well in terms of LCV and, in fact, exceeded vendor specifications. MTF was comparable between CT and linac CBCT. Integral nonuniformity was, on average, 0.002 for the CT and 0.006 for the linac CBCT. Uniformity, LCV and MTF varied depending on the protocols used for the linac CBCT. Contrast-to-noise ratio was an average of 51% higher for the CT than for the linac and simulator CBCT. No significant time trend was observed and tolerance limits were implemented. Discussion: Reasonable differences in image quality between CT and CBCT were observed. Further research and development are necessary to increase image quality of commercially available CBCT devices in order for them to serve the needs for adaptive and/or online planning.

  3. Image quality and stability of image-guided radiotherapy (IGRT) devices: A comparative study.

    Science.gov (United States)

    Stock, Markus; Pasler, Marlies; Birkfellner, Wolfgang; Homolka, Peter; Poetter, Richard; Georg, Dietmar

    2009-10-01

    Our aim was to implement standards for quality assurance of IGRT devices used in our department and to compare their performances with that of a CT simulator. We investigated image quality parameters for three devices over a period of 16months. A multislice CT was used as a benchmark and results related to noise, spatial resolution, low contrast visibility (LCV) and uniformity were compared with a cone beam CT (CBCT) at a linac and simulator. All devices performed well in terms of LCV and, in fact, exceeded vendor specifications. MTF was comparable between CT and linac CBCT. Integral nonuniformity was, on average, 0.002 for the CT and 0.006 for the linac CBCT. Uniformity, LCV and MTF varied depending on the protocols used for the linac CBCT. Contrast-to-noise ratio was an average of 51% higher for the CT than for the linac and simulator CBCT. No significant time trend was observed and tolerance limits were implemented. Reasonable differences in image quality between CT and CBCT were observed. Further research and development are necessary to increase image quality of commercially available CBCT devices in order for them to serve the needs for adaptive and/or online planning.

  4. Macro-SICM: A Scanning Ion Conductance Microscope for Large-Range Imaging.

    Science.gov (United States)

    Schierbaum, Nicolas; Hack, Martin; Betz, Oliver; Schäffer, Tilman E

    2018-04-17

    The scanning ion conductance microscope (SICM) is a versatile, high-resolution imaging technique that uses an electrolyte-filled nanopipet as a probe. Its noncontact imaging principle makes the SICM uniquely suited for the investigation of soft and delicate surface structures in a liquid environment. The SICM has found an ever-increasing number of applications in chemistry, physics, and biology. However, a drawback of conventional SICMs is their relatively small scan range (typically 100 μm × 100 μm in the lateral and 10 μm in the vertical direction). We have developed a Macro-SICM with an exceedingly large scan range of 25 mm × 25 mm in the lateral and 0.25 mm in the vertical direction. We demonstrate the high versatility of the Macro-SICM by imaging at different length scales: from centimeters (fingerprint, coin) to millimeters (bovine tongue tissue, insect wing) to micrometers (cellular extensions). We applied the Macro-SICM to the study of collective cell migration in epithelial wound healing.

  5. 3-D reconstruction of neurons from multichannel confocal laser scanning image series.

    Science.gov (United States)

    Wouterlood, Floris G

    2014-04-10

    A confocal laser scanning microscope (CLSM) collects information from a thin, focal plane and ignores out-of-focus information. Scanning of a specimen, with stepwise axial (Z-) movement of the stage in between each scan, produces Z-series of confocal images of a tissue volume, which then can be used to 3-D reconstruct structures of interest. The operator first configures separate channels (e.g., laser, filters, and detector settings) for each applied fluorochrome and then acquires Z-series of confocal images: one series per channel. Channel signal separation is extremely important. Measures to avoid bleaching are vital. Post-acquisition deconvolution of the image series is often performed to increase resolution before 3-D reconstruction takes place. In the 3-D reconstruction programs described in this unit, reconstructions can be inspected in real time from any viewing angle. By altering viewing angles and by switching channels off and on, the spatial relationships of 3-D-reconstructed structures with respect to structures visualized in other channels can be studied. Since each brand of CLSM, computer program, and 3-D reconstruction package has its own proprietary set of procedures, a general approach is provided in this protocol wherever possible. Copyright © 2014 John Wiley & Sons, Inc.

  6. Tree-structured vector quantization of CT chest scans: Image quality and diagnostic accuracy

    International Nuclear Information System (INIS)

    Cosman, P.C.; Tseng, C.; Gray, R.M.; Olshen, R.A.; Moses, L.E.; Davidson, H.C.; Bergin, C.J.; Riskin, E.A.

    1993-01-01

    The quality of lossy compressed images is often characterized by signal-to-noise ratios, informal tests of subjective quality, or receiver operating characteristic (ROC) curves that include subjective appraisals of the value of an image for a particular application. The authors believe that for medical applications, lossy compressed images should be judged by a more natural and fundamental aspect of relative image quality: their use in making accurate diagnoses. They apply a lossy compression algorithm to medical images, and quantify the quality of the images by the diagnostic performance of radiologists, as well as by traditional signal-to-noise ratios and subjective ratings. The study is unlike previous studies of the effects of lossy compression in that they consider non-binary detection tasks, simulate actual diagnostic practice instead of using paired tests or confidence rankings, use statistical methods that are more appropriate for non-binary clinical data than are the popular ROC curves, and use low-complexity predictive tree-structured vector quantization for compression rather than DCT-based transform codes combined with entropy coding. Their diagnostic tasks are the identification of nodules (tumors) in the lungs and lymphadenopathy in the mediastinum from computerized tomography (CT) chest scans. For the image modality, compression algorithm, and diagnostic tasks they consider, the original 12 bit per pixel (bpp) CT image can be compressed to between 1 bpp and 2 bpp with no significant changes in diagnostic accuracy

  7. Fully time-resolved near-field scanning optical microscopy fluorescence imaging

    International Nuclear Information System (INIS)

    Kwak, Eun-Soo; Vanden Bout, David A.

    2003-01-01

    Time-correlated single photon counting has been coupled with near-field scanning optical microscopy (NSOM) to record complete fluorescence lifetime decays at each pixel in an NSOM image. The resulting three-dimensional data sets can be binned in the time dimension to create images of photons at particular time delays or images of the fluorescence lifetime. Alternatively, regions of interest identified in the topography and fluorescence images can be used to bin the data in the spatial dimensions resulting in high signal to noise fluorescence decays of particular regions of the sample. The technique has been demonstrated on films of poly(vinylalcohol), doped with the fluorescent dye, cascade blue (CB). The CB segregates into small circular regions of high concentration within the films during the drying process. The lifetime imaging shows that the spots have slightly faster excited state decays due to quenching of the luminescence as a result of the higher concentration. The technique is also used to image the fluorescence lifetime of an annealed film of poly(dihexylfluorene). The samples show high contrast in the total intensity fluorescence image, but the lifetime image reveals the sample to be extremely uniform

  8. Spectrally enhanced imaging of occlusal surfaces and artificial shallow enamel erosions with a scanning fiber endoscope

    Science.gov (United States)

    Zhang, Liang; Nelson, Leonard Y.; Seibel, Eric J.

    2012-07-01

    An ultrathin scanning fiber endoscope, originally developed for cancer diagnosis, was used to image dental occlusal surfaces as well as shallow artificially induced enamel erosions from human extracted teeth (n=40). Enhanced image resolution of occlusal surfaces was obtained using a short-wavelength 405-nm illumination laser. In addition, artificial erosions of varying depths were also imaged with 405-, 404-, 532-, and 635-nm illumination lasers. Laser-induced autofluorescence images of the teeth using 405-nm illumination were also obtained. Contrast between sound and eroded enamel was quantitatively computed for each imaging modality. For shallow erosions, the image contrast with respect to sound enamel was greatest for the 405-nm reflected image. It was also determined that the increased contrast was in large part due to volume scattering with a smaller component from surface scattering. Furthermore, images obtained with a shallow penetration depth illumination laser (405 nm) provided the greatest detail of surface enamel topography since the reflected light does not contain contributions from light reflected from greater depths within the enamel tissue. Multilayered Monte Carlo simulations were also performed to confirm the experimental results.

  9. Assessment of image quality in x-ray radiography imaging using a small plasma focus device

    Science.gov (United States)

    Kanani, A.; Shirani, B.; Jabbari, I.; Mokhtari, J.

    2014-08-01

    This paper offers a comprehensive investigation of image quality parameters for a small plasma focus as a pulsed hard x-ray source for radiography applications. A set of images were captured from some metal objects and electronic circuits using a low energy plasma focus at different voltages of capacitor bank and different pressures of argon gas. The x-ray source focal spot of this device was obtained to be about 0.6 mm using the penumbra imaging method. The image quality was studied by several parameters such as image contrast, line spread function (LSF) and modulation transfer function (MTF). Results showed that the contrast changes by variations in gas pressure. The best contrast was obtained at a pressure of 0.5 mbar and 3.75 kJ stored energy. The results of x-ray dose from the device showed that about 0.6 mGy is sufficient to obtain acceptable images on the film. The measurements of LSF and MTF parameters were carried out by means of a thin stainless steel wire 0.8 mm in diameter and the cut-off frequency was obtained to be about 1.5 cycles/mm.

  10. Damage analysis of CF/AF hybrid fabric reinforced plastic laminated composites with scanned image microscopy

    Science.gov (United States)

    Miyasaka, Chiaki; Kasano, Hideaki; Shull, Peter J.

    2004-07-01

    The article presents an experimental study that has been conducted to evaluate the impact loading damage within hybrid fabric laminates-carbon and Aramid fibers. The experiments have been undertaken on a series of interply hybrid specimens with different preprags stacking sequences. Impact damage was created using an air-gun like impact device propelling spherical steel balls with diameters of 5.0mm and 10.0mm and having velocities of 113m/s and 40m/s respectively. The resulting specimen surface and internal damage (e.g., micro-cracking and debonding) was visualized nondestructively by a scanning acoustic microscope (SAM) while further interrogation of specific internal damage was visualized using a scanning electron microscope (SEM) on cross-sectioned panels.

  11. Hemispherical Scanning Imaging DOAS: Resolving nitrogen dioxide in the urban environment

    Science.gov (United States)

    Leigh, R. J.; Graves, R. R.; Lawrence, J.; Faloon, K.; Monks, P. S.

    2012-12-01

    Imaging DOAS techniques have been used for nitrogen dioxide and sulfer dioxide for a number of years. This presentation describes a novel system which images concentrations of nitrogen dioxide by scanning an imaging spectrometer 360 degrees azimuthally, covering a region from 5 degrees below the horizon, to the zenith. The instrument has been built at the University of Leicester (UK), on optical designs by Surrey Satellite Technologies Ltd, and incorporates an Offner relay with Schwarzchild fore-optics, in a rotating mount. The spectrometer offers high fidelity spectroscopic retrievals of nitrogen dioxide as a result of a reliable Gaussian line shape, zero smile and low chromatic aberration. The full hemispherical scanning provides complete coverage of nitrogen dioxide concentrations above approximately 5 ppbv in urban environments. Through the use of multiple instruments, the three-dimensional structure of nitrogen dioxide can be sampled and tomographically reconstructed, providing valuable information on nitrogen dioxide emissions and downwind exposure, in addition to new understanding of boundary layer dynamics through the use of nitrogen dioxide as a tracer. Furthermore, certain aerosol information can be retrieved through absolute intensity measurements in each azimuthal direction supplemented by traditional techniques of O4 spectroscopy. Such measurements provide a new tool for boundary layer measurement and monitoring at a time when air quality implications on human health and climate are under significant scrutiny. This presentation will describe the instrument and tomographic potential of this technique. First measurements were taken as part of the international PEGASOS campaign in Bologna, Italy. Results from these measurements will be shown, including imaging of enhanced NO2 in the Bologna urban boundary layer during a severe thunderstorm. A Hemispherical Scanning Imaging DOAS instrument operating in Bologna, Italy in June 2012. Visible in the background

  12. Displaced dual-mode imaging with desorption electrospray ionization for simultaneous mass spectrometry imaging in both polarities and with several scan modes

    DEFF Research Database (Denmark)

    Janfelt, Christian; Wellner, Niels; Hansen, Harald S

    2013-01-01

    only. Simultaneous full-scan and MS/MS imaging was demonstrated on the same mouse kidney, as the mouse had been given a relatively low dose of the antidepressive drug amitriptyline. While the full-scan data allowed imaging of the endogenous phospholipids, the drug and its metabolites were only visible...

  13. Derivation of the scan time requirement for maintaining a consistent PET image quality

    International Nuclear Information System (INIS)

    Kim, Jin Su; Lee, Jae Sung; Kim, Seok-Ki

    2015-01-01

    Objectives: the image quality of PET for larger patients is relatively poor, even though the injection dose is optimized considering the NECR characteristics of the PET scanner. This poor image quality is due to the lower level of maximum NECR that can be achieved in these large patients. The aim of this study was to optimize the PET scan time to obtain a consistent PET image quality regardless of the body size, based on the relationship between the patient specific NECR (pNECR) and body weight. Methods: eighty patients (M/F=53/27, body weight: 059 ± 1 kg) underwent whole-body FDG PET scans using a Philips GEMINI GS PET/CT scanner after an injection of 0.14 mCi/kg FDG. The relationship between the scatter fraction (SF) and body weight was determined by repeated Monte Carlo simulations using a NEMA scatter phantom, the size of which varied according to the relationship between the abdominal circumference and body weight. Using this information, the pNECR was calculated from the prompt and delayed PET sinograms to obtain the prediction equation of NECR vs. body weight. The time scaling factor (F TS ) for the scan duration was finally derived to make PET images with equivalent SNR levels. Results: the SF and NECR had the following nonlinear relationships with the body weight: SF=0.15 ⋅ body weight 0.3 and NECR = 421.36 (body weight) −0.84 . The equation derived for F TS was 0.01⋅ body weight + 0.2, which means that, for example, a 120-kg person should be scanned 1.8 times longer than a 70 kg person, or the scan time for a 40-kg person can be reduced by 30%. Conclusion: the equation of the relative time demand derived in this study will be useful for maintaining consistent PET image quality in clinics

  14. Scanning Capacitance Microscopy | Materials Science | NREL

    Science.gov (United States)

    obtained using scanning capacitance microscopy. Top Right: Image of p-type and n-type material, obtained 'fingers' of light-colored n-type material on a yellow and blue background representing p-type material material, obtained using scanning capacitance microscopy, in a sample semiconductor device; the image shows

  15. Noninvasive imaging of the human rod photoreceptor mosaic using a confocal adaptive optics scanning ophthalmoscope

    Science.gov (United States)

    Dubra, Alfredo; Sulai, Yusufu; Norris, Jennifer L.; Cooper, Robert F.; Dubis, Adam M.; Williams, David R.; Carroll, Joseph

    2011-01-01

    The rod photoreceptors are implicated in a number of devastating retinal diseases. However, routine imaging of these cells has remained elusive, even with the advent of adaptive optics imaging. Here, we present the first in vivo images of the contiguous rod photoreceptor mosaic in nine healthy human subjects. The images were collected with three different confocal adaptive optics scanning ophthalmoscopes at two different institutions, using 680 and 775 nm superluminescent diodes for illumination. Estimates of photoreceptor density and rod:cone ratios in the 5°–15° retinal eccentricity range are consistent with histological findings, confirming our ability to resolve the rod mosaic by averaging multiple registered images, without the need for additional image processing. In one subject, we were able to identify the emergence of the first rods at approximately 190 μm from the foveal center, in agreement with previous histological studies. The rod and cone photoreceptor mosaics appear in focus at different retinal depths, with the rod mosaic best focus (i.e., brightest and sharpest) being at least 10 μm shallower than the cones at retinal eccentricities larger than 8°. This study represents an important step in bringing high-resolution imaging to bear on the study of rod disorders. PMID:21750765

  16. Spectral imaging technique for retinal perfusion detection using confocal scanning laser ophthalmoscopy

    Science.gov (United States)

    Rasta, Seyed Hossein; Manivannan, Ayyakkannu; Sharp, Peter F.

    2012-11-01

    To evaluate retinal perfusion in the human eye, a dual-wavelength confocal scanning laser ophthalmoscope (cSLO) was developed that provides spectral imaging of the fundus using a combination of red (670 nm) and near-infrared (810 nm) wavelengths. The image of the ocular fundus was analyzed to find out if quantitative measurements of the reflectivity of tissue permit assessment of the oxygen perfusion of tissue. We explored problems that affect the reproducibility of patient measurements such as non-uniformity errors on the image. For the first time, an image processing technique was designed and used to minimize the errors of oxygen saturation measurements by illumination correction in retina wide field by increasing SNR. Retinal images were taken from healthy and diabetic retinopathy eyes using the cSLO with a confocal aperture of 100 μm. The ratio image (RI) of red/IR, as oxygen saturation (SO2) index, was calculated for normal eyes. The image correction technique improved the reproducibility of the measurements. Average RI intensity variation of healthy retina tissue was determined within a range of about 5.5%. The capability of the new technique to discriminate oxygenation levels of retinal artery and vein was successfully demonstrated and showed good promise in the diagnosis of the perfused retina.

  17. Development of a miniature multiple reference optical coherence tomography imaging device

    Science.gov (United States)

    McNamara, Paul M.; O'Riordan, Colm; Collins, Seán.; O'Brien, Peter; Wilson, Carol; Hogan, Josh; Leahy, Martin J.

    2016-03-01

    Multiple reference optical coherence tomography (MR-OCT) is a new technology ideally suited to low-cost, compact OCT imaging. This modality is an extension of time-domain OCT with the addition of a partial mirror in front of the reference mirror. This enables extended, simultaneous depth scanning with the relatively short sweep of a miniature voice coil motor on which the scanning mirror is mounted. Applications of this technology include biometric security, ophthalmology, personal health monitoring and non-destructive testing. This work details early-stage development of the first iteration of a miniature MR-OCT device. This device utilizes a fiber-coupled input from an off-board superluminescent diode (SLD). Typical dimensions of the module are 40 × 57 mm, but future designs are expected to be more compact. Off-the-shelf miniature optical components, voice coil motors and photodetectors are used, with the complexity of design depending on specific applications. The photonic module can be configured as either polarized or non-polarized and can include balanced detection. The photodetectors are directly connected to a printed circuit board under the module containing a transimpedance amplifier with complimentary outputs. The results shown in this work are from the non-polarized device. Assembly of the photonic modules requires extensive planning. In choosing the optical components, Zemax simulations are performed to model the beam characteristics. The physical layout is modeled using Solidworks and each component is placed and aligned via a well-designed alignment procedure involving an active-alignment pick-and-place assembly system.

  18. Scanning-SQUID investigation of spin-orbit torque acting on yttrium iron garnet devices

    Science.gov (United States)

    Rosenberg, Aaron J.; Jermain, Colin L.; Aradhya, Sriharsha V.; Brangham, Jack T.; Nowack, Katja C.; Kirtley, John R.; Yang, Fengyuan; Ralph, Daniel C.; Moler, Kathryn A.

    Successful manipulation of electrically insulating magnets, such as yttrium iron garnet, by by current-driven spin-orbit torques could provide a highly efficient platform for spintronic memory. Compared to devices fabricated using magnetic metals, magnetic insulators have the advantage of the ultra-low magnetic damping and the elimination of shunting currents in the magnet that reduce the torque efficiency. Here, we apply current in the spin Hall metal β-Ta to manipulate the magnetic orientation of micron-sized, electrically-insulating yttrium iron garnet devices. We do not observe spin-torque switching even for applied currents well above the critical current expected in a macrospin switching model. This suggests either inefficient transfer of spin torque at our Ta/YIG interface or a breakdown of the macrospin approximation. This work is supported by FAME, one of six centers of STARnet sponsored by MARCO and DARPA. The SQUID microscope and sensors were developed with support from the NSF-sponsored Center NSF-NSEC 0830228, and from NSF IMR-MIP 0957616.

  19. Determination of tire cross-sectional geometric characteristics from a digitally scanned image

    Science.gov (United States)

    Danielson, Kent T.

    1995-08-01

    A semi-automated procedure is described for the accurate determination of geometrical characteristics using a scanned image of the tire cross-section. The procedure can be useful for cases when CAD drawings are not available or when a description of the actual cured tire is desired. Curves representing the perimeter of the tire cross-section are determined by an edge tracing scheme, and the plyline and cord-end positions are determined by locations of color intensities. The procedure provides an accurate description of the perimeter of the tire cross-section and the locations of plylines and cord-ends. The position, normals, and curvatures of the cross-sectional surface are included in this description. The locations of the plylines provide the necessary information for determining the ply thicknesses and relative position to a reference surface. Finally, the locations of the cord-ends provide a means to calculate the cord-ends per inch (epi). Menu driven software has been developed to facilitate the procedure using the commercial code, PV-Wave by Visual Numerics, Inc., to display the images. From a single user interface, separate modules are executed for image enhancement, curve fitting the edge trace of the cross-sectional perimeter, and determining the plyline and cord-end locations. The code can run on SUN or SGI workstations and requires the use of a mouse to specify options or identify items on the scanned image.

  20. The impact of the depth of field on cytogenetic image quality in scanning microscopy

    Science.gov (United States)

    Qiu, Yuchen; Chen, Xiaodong; Li, Yuhua; Zheng, Bin; Li, Shibo; Zhang, Roy R.; Chen, Wei R.; Liu, Hong

    2011-03-01

    The purpose of this study is to investigate the impact of the depth of field (DOF) of microscopic systems on cytogenetic image qualities. Due to the narrow DOF of high magnification, large numerical aperture (N.A.) objective lenses, random vibrations of even high precision scanning stages may result in large amount of off focused images. In this study, the DOF of microscopic systems with various objective magnifications/numerical apertures (N.A.) is first measured using standard resolution targets. The impact of DOF on cytogenetic image qualities is then subjectively evaluated with clinical samples, by comparing the band shape and sharpness of analyzable chromosomes. For a specific digital microscopic system with 100× objective lens (N.A. = 1.25), the results of observational studies revealed that chromosomal bands are still recognizable when the images are obtained approximately +/- 1 μm from the focusing plane. The chromosomal bands become fuzzy and unrecognizable when the system is 1.5 μm away from the focusing position. The results of this preliminary experimental study may provide useful design trade-off parameters for developing optimal scanning microscopic systems for cytogenetic applications.

  1. High resolution scanning optical imaging of a frozen planar polymer light-emitting electrochemical cell: an experimental and modelling study

    Institute of Scientific and Technical Information of China (English)

    Faleh AlTal; Jun Gao

    2017-01-01

    Light-emitting electrochemical cells (LECs) are organic photonic devices based on a mixed electronic and ionic conductor.The active layer of a polymer-based LEC consists of a luminescent polymer,an ion-solvating/transport polymer,and a compatible salt.The LEC p-n or p-i-n junction is ultimately responsible for the LEC performance.The LEC junction,however,is still poorly understood due to the difficulties of characterizing a dynamic-junction LEC.In this paper,we present an experimental and modeling study of the LEC junction using scanning optical imaging techniques.Planar LECs with an interelectrode spacing of 560 μm have been fabricated,activated,frozen and scanned using a focused laser beam.The optical-beam-induced-current (OBIC) and photoluminescence (PL) data have been recorded as a function of beam location.The OBIC profile has been simulated in COMSOL that allowed for the determination of the doping concentration and the depletion width of the LEC junction.

  2. Comprehensive model for predicting perceptual image quality of smart mobile devices.

    Science.gov (United States)

    Gong, Rui; Xu, Haisong; Luo, M R; Li, Haifeng

    2015-01-01

    An image quality model for smart mobile devices was proposed based on visual assessments of several image quality attributes. A series of psychophysical experiments were carried out on two kinds of smart mobile devices, i.e., smart phones and tablet computers, in which naturalness, colorfulness, brightness, contrast, sharpness, clearness, and overall image quality were visually evaluated under three lighting environments via categorical judgment method for various application types of test images. On the basis of Pearson correlation coefficients and factor analysis, the overall image quality could first be predicted by its two constituent attributes with multiple linear regression functions for different types of images, respectively, and then the mathematical expressions were built to link the constituent image quality attributes with the physical parameters of smart mobile devices and image appearance factors. The procedure and algorithms were applicable to various smart mobile devices, different lighting conditions, and multiple types of images, and performance was verified by the visual data.

  3. Renal scan

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003790.htm Renal scan To use the sharing features on this ... anaphylaxis . Alternative Names Renogram; Kidney scan Images Kidney anatomy Kidney - blood and urine flow References Chernecky CC, ...

  4. Coherent x-ray diffraction imaging of paint pigment particles by scanning a phase plate modulator

    International Nuclear Information System (INIS)

    Chu, Y.S.; Chen, B.; Zhang, F.; Berenguer, F.; Bean, R.; Kewish, C.; Vila-Comamala, J.; Rodenburg, J.; Robinson, I.

    2011-01-01

    We have implemented a coherent x-ray diffraction imaging technique that scans a phase plate to modulate wave-fronts of the x-ray beam transmitted by samples. The method was applied to measure a decorative alkyd paint containing iron oxide red pigment particles. By employing an iterative algorithm for wave-front modulation phase retrieval, we obtained an image of the paint sample that shows the distribution of the pigment particles and is consistent with the result obtained from a transmission x-ray microscope. The technique has been experimentally proven to be a feasible coherent x-ray imaging method with about 120 nm spatial resolution and was shown to work well with industrially relevant specimens.

  5. Imaging of surface spin textures on bulk crystals by scanning electron microscopy

    Science.gov (United States)

    Akamine, Hiroshi; Okumura, So; Farjami, Sahar; Murakami, Yasukazu; Nishida, Minoru

    2016-11-01

    Direct observation of magnetic microstructures is vital for advancing spintronics and other technologies. Here we report a method for imaging surface domain structures on bulk samples by scanning electron microscopy (SEM). Complex magnetic domains, referred to as the maze state in CoPt/FePt alloys, were observed at a spatial resolution of less than 100 nm by using an in-lens annular detector. The method allows for imaging almost all the domain walls in the mazy structure, whereas the visualisation of the domain walls with the classical SEM method was limited. Our method provides a simple way to analyse surface domain structures in the bulk state that can be used in combination with SEM functions such as orientation or composition analysis. Thus, the method extends applications of SEM-based magnetic imaging, and is promising for resolving various problems at the forefront of fields including physics, magnetics, materials science, engineering, and chemistry.

  6. Remote defect imaging for plate-like structures based on the scanning laser source technique

    Science.gov (United States)

    Hayashi, Takahiro; Maeda, Atsuya; Nakao, Shogo

    2018-04-01

    In defect imaging with a scanning laser source technique, the use of a fixed receiver realizes stable measurements of flexural waves generated by laser at multiple rastering points. This study discussed the defect imaging by remote measurements using a laser Doppler vibrometer as a receiver. Narrow-band burst waves were generated by modulating laser pulse trains of a fiber laser to enhance signal to noise ratio in frequency domain. Averaging three images obtained at three different frequencies suppressed spurious distributions due to resonance. The experimental system equipped with these newly-devised means enabled us to visualize defects and adhesive objects in plate-like structures such as a plate with complex geometries and a branch pipe.

  7. Classification of underground pipe scanned images using feature extraction and neuro-fuzzy algorithm.

    Science.gov (United States)

    Sinha, S K; Karray, F

    2002-01-01

    Pipeline surface defects such as holes and cracks cause major problems for utility managers, particularly when the pipeline is buried under the ground. Manual inspection for surface defects in the pipeline has a number of drawbacks, including subjectivity, varying standards, and high costs. Automatic inspection system using image processing and artificial intelligence techniques can overcome many of these disadvantages and offer utility managers an opportunity to significantly improve quality and reduce costs. A recognition and classification of pipe cracks using images analysis and neuro-fuzzy algorithm is proposed. In the preprocessing step the scanned images of pipe are analyzed and crack features are extracted. In the classification step the neuro-fuzzy algorithm is developed that employs a fuzzy membership function and error backpropagation algorithm. The idea behind the proposed approach is that the fuzzy membership function will absorb variation of feature values and the backpropagation network, with its learning ability, will show good classification efficiency.

  8. Phase-selective staining of metal salt for scanning electron microscopy imaging of block copolymer film

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jing Ze, E-mail: Lijinge@uestc.edu.cn [State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Microelectronic and Solid-state Electronic, University of Electronic Science and Technology of China, Chengdu 610054 (China); State Key Laboratory of Polymer Materials Engineering (Sichuan University), Chengdu 610054 (China); Xinjiang Key Laboratory of Electronic Information Materials and Devices, Urumuqi 830011 (China); Wang, Ying; Hong Wang, Zhi; Mei, Di; Zou, Wei [State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Microelectronic and Solid-state Electronic, University of Electronic Science and Technology of China, Chengdu 610054 (China); Min Chang, Ai [State Key Laboratory of Polymer Materials Engineering (Sichuan University), Chengdu 610054 (China); Wang, Qi [Xinjiang Key Laboratory of Electronic Information Materials and Devices, Urumuqi 830011 (China); Komura, Motonori; Ito, Kaori [Division of Integrated Molecular Engineering, Chemical Resources Laboratory, Tokyo Institute of Technology, Yokohama 226-8503 (Japan); Iyoda, Tomokazu, E-mail: Iyoda.t.aa@m.titech.ac.jp [Division of Integrated Molecular Engineering, Chemical Resources Laboratory, Tokyo Institute of Technology, Yokohama 226-8503 (Japan)

    2010-09-15

    Three metal salts, i.e., AgNO{sub 3}, HAuCl{sub 4}, and KCl, were proposed as novel staining reagents instead of traditional RuO{sub 4} and OsO{sub 4} labeled with expensive price and extreme toxicity for scanning electron microscopy (SEM) imaging of microphase separated block copolymer film. A simple and costless aqueous solution immersion procedure could ensure selective staining of the metal slat in specific phase of the nanostructured copolymer film, leading to a clear phase contrasted SEM image. The heavy metal salt has better staining effect, demonstrating stable and high signal-to-noise SEM image even at an acceleration voltage as high as 30 kV and magnification up to 250,000 times.

  9. Image interpolation allows accurate quantitative bone morphometry in registered micro-computed tomography scans.

    Science.gov (United States)

    Schulte, Friederike A; Lambers, Floor M; Mueller, Thomas L; Stauber, Martin; Müller, Ralph

    2014-04-01

    Time-lapsed in vivo micro-computed tomography is a powerful tool to analyse longitudinal changes in the bone micro-architecture. Registration can overcome problems associated with spatial misalignment between scans; however, it requires image interpolation which might affect the outcome of a subsequent bone morphometric analysis. The impact of the interpolation error itself, though, has not been quantified to date. Therefore, the purpose of this ex vivo study was to elaborate the effect of different interpolator schemes [nearest neighbour, tri-linear and B-spline (BSP)] on bone morphometric indices. None of the interpolator schemes led to significant differences between interpolated and non-interpolated images, with the lowest interpolation error found for BSPs (1.4%). Furthermore, depending on the interpolator, the processing order of registration, Gaussian filtration and binarisation played a role. Independent from the interpolator, the present findings suggest that the evaluation of bone morphometry should be done with images registered using greyscale information.

  10. 3D change detection at street level using mobile laser scanning point clouds and terrestrial images

    Science.gov (United States)

    Qin, Rongjun; Gruen, Armin

    2014-04-01

    Automatic change detection and geo-database updating in the urban environment are difficult tasks. There has been much research on detecting changes with satellite and aerial images, but studies have rarely been performed at the street level, which is complex in its 3D geometry. Contemporary geo-databases include 3D street-level objects, which demand frequent data updating. Terrestrial images provides rich texture information for change detection, but the change detection with terrestrial images from different epochs sometimes faces problems with illumination changes, perspective distortions and unreliable 3D geometry caused by the lack of performance of automatic image matchers, while mobile laser scanning (MLS) data acquired from different epochs provides accurate 3D geometry for change detection, but is very expensive for periodical acquisition. This paper proposes a new method for change detection at street level by using combination of MLS point clouds and terrestrial images: the accurate but expensive MLS data acquired from an early epoch serves as the reference, and terrestrial images or photogrammetric images captured from an image-based mobile mapping system (MMS) at a later epoch are used to detect the geometrical changes between different epochs. The method will automatically mark the possible changes in each view, which provides a cost-efficient method for frequent data updating. The methodology is divided into several steps. In the first step, the point clouds are recorded by the MLS system and processed, with data cleaned and classified by semi-automatic means. In the second step, terrestrial images or mobile mapping images at a later epoch are taken and registered to the point cloud, and then point clouds are projected on each image by a weighted window based z-buffering method for view dependent 2D triangulation. In the next step, stereo pairs of the terrestrial images are rectified and re-projected between each other to check the geometrical

  11. Fundamental imaging characteristics of a slot-scan digital chest radiographic system

    International Nuclear Information System (INIS)

    Samei, Ehsan; Saunders, Robert S.; Lo, Joseph Y.; Dobbins, James T. III; Jesneck, Jonathan L.; Floyd, Carey E.; Ravin, Carl E.

    2004-01-01

    Our purpose in this study was to evaluate the fundamental image quality characteristics of a new slot-scan digital chest radiography system (ThoraScan, Delft Imaging Systems/Nucletron, Veenendaal, The Netherlands). The linearity of the system was measured over a wide exposure range at 90, 117, and 140 kVp with added Al filtration. System uniformity and reproducibility were established with an analysis of images from repeated exposures. The modulation transfer function (MTF) was evaluated using an established edge method. The noise power spectrum (NPS) and the detective quantum efficiency (DQE) of the system were evaluated at the three kilo-voltages over a range of exposures. Scatter fraction (SF) measurements were made using a posterior beam stop method and a geometrical chest phantom. The system demonstrated excellent linearity, but some structured nonuniformities. The 0.1 MTF values occurred between 3.3-3.5 mm -1 . The DQE(0.15) and DQE(2.5) were 0.21 and 0.07 at 90 kVp, 0.18 and 0.05 at 117 kVp, and 0.16 and 0.03 at 140 kVp, respectively. The system exhibited remarkably lower SFs compared to conventional full-field systems with anti-scatter grid, measuring 0.13 in the lungs and 0.43 in the mediastinum. The findings indicated that the slot-scan design provides marked scatter reduction leading to high effective DQE (DQE eff ) of the system and reduced patient dose required to achieve high image quality

  12. Relative location prediction in CT scan images using convolutional neural networks.

    Science.gov (United States)

    Guo, Jiajia; Du, Hongwei; Zhu, Jianyue; Yan, Ting; Qiu, Bensheng

    2018-07-01

    Relative location prediction in computed tomography (CT) scan images is a challenging problem. Many traditional machine learning methods have been applied in attempts to alleviate this problem. However, the accuracy and speed of these methods cannot meet the requirement of medical scenario. In this paper, we propose a regression model based on one-dimensional convolutional neural networks (CNN) to determine the relative location of a CT scan image both quickly and precisely. In contrast to other common CNN models that use a two-dimensional image as an input, the input of this CNN model is a feature vector extracted by a shape context algorithm with spatial correlation. Normalization via z-score is first applied as a pre-processing step. Then, in order to prevent overfitting and improve model's performance, 20% of the elements of the feature vectors are randomly set to zero. This CNN model consists primarily of three one-dimensional convolutional layers, three dropout layers and two fully-connected layers with appropriate loss functions. A public dataset is employed to validate the performance of the proposed model using a 5-fold cross validation. Experimental results demonstrate an excellent performance of the proposed model when compared with contemporary techniques, achieving a median absolute error of 1.04 cm and mean absolute error of 1.69 cm. The time taken for each relative location prediction is approximately 2 ms. Results indicate that the proposed CNN method can contribute to a quick and accurate relative location prediction in CT scan images, which can improve efficiency of the medical picture archiving and communication system in the future. Copyright © 2018 Elsevier B.V. All rights reserved.

  13. Role of radioisotope scanning in the coordinated imaging of urinary tract disease

    International Nuclear Information System (INIS)

    Rosenfield, A.T.; Bird, K.I.; Zeman, R.K.

    1988-01-01

    In this chapter, the authors consider approaches to several commonly encountered urinary tract problems. Until recently, the safety and efficacy of a diagnostic study has been the major determinant of its role. Radioisotope imaging of the urinary tract, an extremely safe technique, was generally recommended for any situation in which it was applicable. There are now new factors, cost and speed, that have come to the forefront. Ultrasonagraphy is a technique that is rapid, safe, and for many indications less expensive than scintigraphy. Computed tomography, although less safe than radioisotope scanning, is extremely accurate, relatively rapid, and provides reliable guidance for interventional procedures. In an era of DRGs with extreme pressure on hospitals to make an exact diagnosis early in the patient's stay in order to limit hospitalization time, CT and sonography have become widely used for many applications for isotope scanning. Thus, economics rather than patient comfort and safety may restrict the role of isotope scanning in future patient management. Magnetic resonance imaging, with spectroscopy having the potential to evaluate physiologic parameters, will also compete with scintigraphy in many situations

  14. RAPTOR-scan: Identifying and Tracking Objects Through Thousands of Sky Images

    International Nuclear Information System (INIS)

    Davidoff, Sherri; Wozniak, Przemyslaw

    2004-01-01

    The RAPTOR-scan system mines data for optical transients associated with gamma-ray bursts and is used to create a catalog for the RAPTOR telescope system. RAPTOR-scan can detect and track individual astronomical objects across data sets containing millions of observed points.Accurately identifying a real object over many optical images (clustering the individual appearances) is necessary in order to analyze object light curves. To achieve this, RAPTOR telescope observations are sent in real time to a database. Each morning, a program based on the DBSCAN algorithm clusters the observations and labels each one with an object identifier. Once clustering is complete, the analysis program may be used to query the database and produce light curves, maps of the sky field, or other informative displays.Although RAPTOR-scan was designed for the RAPTOR optical telescope system, it is a general tool designed to identify objects in a collection of astronomical data and facilitate quick data analysis. RAPTOR-scan will be released as free software under the GNU General Public License

  15. Development of techniques and methods for evaluation of quality of scanned image in mammography

    International Nuclear Information System (INIS)

    Carmo Santana, P. do; Nogueira, M.S.

    2008-01-01

    Cancer is the second cause of death in the Brazilian female population and breast cancer is the most frequent neoplasm amongst women. Mammography is an essential tool for diagnosis and early detection of this disease. In order to be effective, the mammography must be of good quality. The Brazilian College of Radiology (CBR), the National Agency for Health Surveillance (ANVISA) and international bodies recommend standards of practice for mammography. Due to the risk of ionizing radiation, techniques that minimize dose and optimize image quality are essential to ensure that all women are submitted to mammography procedures of high quality for the detection of breast cancer. In this research were analyzed components of the image treatment via digital and developed methods and techniques of analysis aiming the detection of structures for medical diagnosis, decreasing variations due to subjectivity. It used free software Image J, to make the evaluations of the information contained in the scanned images. We use the scanned images of calibration of a simulated breast to calibrate the program Image J. Thus, it was able to correctly convert the values of the scale of shades of gray in optical density values of presenting the standard deviation for each measure held. Applying the test t-student noticed that the values obtained with the digital system to the level of contrast and spatial resolution are consistent with the results obtained so subjective, since there was no significant difference (p <0.05) for all comparisons evaluated. Since then, this methodology is recommended in routine evaluations of services of mammography. (author)

  16. Multimodal ophthalmic imaging using spectrally encoded scanning laser ophthalmoscopy and optical coherence tomography

    Science.gov (United States)

    El-Haddad, Mohamed T.; Malone, Joseph D.; Li, Jianwei D.; Bozic, Ivan; Arquitola, Amber M.; Joos, Karen M.; Patel, Shriji N.; Tao, Yuankai K.

    2017-08-01

    Ophthalmic surgery involves manipulation of delicate, layered tissue structures on milli- to micrometer scales. Traditional surgical microscopes provide an inherently two-dimensional view of the surgical field with limited depth perception which precludes accurate depth-resolved visualization of these tissue layers, and limits the development of novel surgical techniques. We demonstrate multimodal swept-source spectrally encoded scanning laser ophthalmoscopy and optical coherence tomography (SS-SESLO-OCT) to address current limitations of image-guided ophthalmic microsurgery. SS-SESLO-OCT provides inherently co-registered en face and cross-sectional field-of-views (FOVs) at a line rate of 400 kHz and >2 GPix/s throughput. We show in vivo imaging of the anterior segment and retinal fundus of a healthy volunteer, and preliminary results of multi-volumetric mosaicking for ultrawide-field retinal imaging with 90° FOV. Additionally, a scan-head was rapid-prototyped with a modular architecture which enabled integration of SS-SESLO-OCT with traditional surgical microscope and slit-lamp imaging optics. Ex vivo surgical maneuvers were simulated in cadaveric porcine eyes. The system throughput enabled volumetric acquisition at 10 volumes-per-second (vps) and allowed visualization of surgical dynamics in corneal sweeps, compressions, and dissections, and retinal sweeps, compressions, and elevations. SESLO en face images enabled simple real-time co-registration with the surgical microscope FOV, and OCT cross-sections provided depth-resolved visualization of instrument-tissue interactions. Finally, we demonstrate novel augmented-reality integration with the surgical view using segmentation overlays to aid surgical guidance. SS-SESLO-OCT may benefit clinical diagnostics by enabling aiming, registration, and mosaicking; and intraoperative imaging by allowing for real-time surgical feedback, instrument tracking, and overlays of computationally extracted biomarkers of disease.

  17. CRionScan: A stand-alone real time controller designed to perform ion beam imaging, dose controlled irradiation and proton beam writing

    Science.gov (United States)

    Daudin, L.; Barberet, Ph.; Serani, L.; Moretto, Ph.

    2013-07-01

    High resolution ion microbeams, usually used to perform elemental mapping, low dose targeted irradiation or ion beam lithography needs a very flexible beam control system. For this purpose, we have developed a dedicated system (called “CRionScan”), on the AIFIRA facility (Applications Interdisciplinaires des Faisceaux d'Ions en Région Aquitaine). It consists of a stand-alone real-time scanning and imaging instrument based on a Compact Reconfigurable Input/Output (Compact RIO) device from National Instruments™. It is based on a real-time controller, a Field Programmable Gate Array (FPGA), input/output modules and Ethernet connectivity. We have implemented a fast and deterministic beam scanning system interfaced with our commercial data acquisition system without any hardware development. CRionScan is built under LabVIEW™ and has been used on AIFIRA's nanobeam line since 2009 (Barberet et al., 2009, 2011) [1,2]. A Graphical User Interface (GUI) embedded in the Compact RIO as a web page is used to control the scanning parameters. In addition, a fast electrostatic beam blanking trigger has been included in the FPGA and high speed counters (15 MHz) have been implemented to perform dose controlled irradiation and on-line images on the GUI. Analog to Digital converters are used for the beam current measurement and in the near future for secondary electrons imaging. Other functionalities have been integrated in this controller like LED lighting using Pulse Width Modulation and a “NIM Wilkinson ADC” data acquisition.

  18. CRionScan: A stand-alone real time controller designed to perform ion beam imaging, dose controlled irradiation and proton beam writing

    Energy Technology Data Exchange (ETDEWEB)

    Daudin, L., E-mail: daudin@cenbg.in2p3.fr [Université Bordeaux, CENBG, UMR 5797, F-33170 Gradignan (France); CNRS, IN2P3, CENBG, UMR 5797, F-33170 Gradignan (France); Barberet, Ph.; Serani, L.; Moretto, Ph. [Université Bordeaux, CENBG, UMR 5797, F-33170 Gradignan (France); CNRS, IN2P3, CENBG, UMR 5797, F-33170 Gradignan (France)

    2013-07-01

    High resolution ion microbeams, usually used to perform elemental mapping, low dose targeted irradiation or ion beam lithography needs a very flexible beam control system. For this purpose, we have developed a dedicated system (called “CRionScan”), on the AIFIRA facility (Applications Interdisciplinaires des Faisceaux d’Ions en Région Aquitaine). It consists of a stand-alone real-time scanning and imaging instrument based on a Compact Reconfigurable Input/Output (Compact RIO) device from National Instruments™. It is based on a real-time controller, a Field Programmable Gate Array (FPGA), input/output modules and Ethernet connectivity. We have implemented a fast and deterministic beam scanning system interfaced with our commercial data acquisition system without any hardware development. CRionScan is built under LabVIEW™ and has been used on AIFIRA’s nanobeam line since 2009 (Barberet et al., 2009, 2011) [1,2]. A Graphical User Interface (GUI) embedded in the Compact RIO as a web page is used to control the scanning parameters. In addition, a fast electrostatic beam blanking trigger has been included in the FPGA and high speed counters (15 MHz) have been implemented to perform dose controlled irradiation and on-line images on the GUI. Analog to Digital converters are used for the beam current measurement and in the near future for secondary electrons imaging. Other functionalities have been integrated in this controller like LED lighting using Pulse Width Modulation and a “NIM Wilkinson ADC” data acquisition.

  19. Comparison of corneal power obtained from VERION image-guided surgery system and four other devices

    Directory of Open Access Journals (Sweden)

    Lin HY

    2017-07-01

    Full Text Available Hung-Yuan Lin,1,* Hsin-Yang Chen,1,2,* Han Bor Fam,3 Ya-Jung Chuang,1 Ronald Yeoh,4 Pi-Jung Lin5 1Universal Eye Center, Zhongli Branch, Zhongli County, TaoYuan City, Taiwan, Republic of China; 2Ophthalmology Department, Ningbo First Hospital, Ningbo, Zhejiang Province, People’s Republic of China; 3Ophthalmology Department, Tan Tock Seng Hospital, Jalan Tan Tock Seng, 4Ophthalmology Department, Eye and Retina Surgeons, Camden Medical Centre, Singapore; 5Universal Eye Center, Xinnan Branch, Taipei City, Taiwan, Republic of China *These authors contributed equally to this work Purpose: To assess the corneal keratometric values obtained using the VERION image-guided surgery system and other devices.Methods: This study evaluated the right eyes of 115 cataract patients before intraocular lens (IOL implantation through consecutive tests using 5 devices: VERION Reference Unit , Placido-based corneal topography (OPD-Scan III, monochromatic light-emitting diodes (LenStar LS900 and AL-Scan, and rotary prism technology (auto kerato-refractometer KR-8800. Analyzed parameters were corneal steep and flat keratometric values (Ks and Kf and corneal astigmatism and axis. These parameters were evaluated using the one-sample two-tailed t-test and the 95% limits of agreement (95% LOAs between the devices.Results: The mean corneal cylinder value measurements were -0.97±0.63 D, -0.88± 0.60 D, -0.90±0.69 D, -0.90±0.67 D, and -0.83±0.60 D with VERION, LenStar, AL-Scan (2.4 mm, OPD III, and KR-8800, respectively. Only KR-8800 showed a significant difference from VERION in the corneal cylinder value (P<0.05. The mean differences in the Kf and Ks of VERION compared to those of OPD III were 0.18±0.45 D and 0.17±0.38 D (P<0.05, respectively. The 95% LOAs of Bland–Altman analysis for the corneal astigmatism axis of the VERION with LenStar, AL-Scan (2.4 mm, OPD III, and KR-8800 were -26.25° to 58.71°, -20.61° to 47.44°, -25.03° to 58.98°, and -27.85

  20. New Insights on Subsurface Imaging of Carbon Nanotubes in Polymer Composites via Scanning Electron Microscopy

    Science.gov (United States)

    Zhao, Minhua; Ming, Bin; Kim, Jae-Woo; Gibbons, Luke J.; Gu, Xiaohong; Nguyen, Tinh; Park, Cheol; Lillehei, Peter T.; Villarrubia, J. S.; Vladar, Andras E.; hide

    2015-01-01

    Despite many studies of subsurface imaging of carbon nanotube (CNT)-polymer composites via scanning electron microscopy (SEM), significant controversy exists concerning the imaging depth and contrast mechanisms. We studied CNT-polyimide composites and, by threedimensional reconstructions of captured stereo-pair images, determined that the maximum SEM imaging depth was typically hundreds of nanometers. The contrast mechanisms were investigated over a broad range of beam accelerating voltages from 0.3 to 30 kV, and ascribed to modulation by embedded CNTs of the effective secondary electron (SE) emission yield at the polymer surface. This modulation of the SE yield is due to non-uniform surface potential distribution resulting from current flows due to leakage and electron beam induced current. The importance of an external electric field on SEM subsurface imaging was also demonstrated. The insights gained from this study can be generally applied to SEM nondestructive subsurface imaging of conducting nanostructures embedded in dielectric matrices such as graphene-polymer composites, silicon-based single electron transistors, high resolution SEM overlay metrology or e-beam lithography, and have significant implications in nanotechnology.

  1. Image quality of multiplanar reconstruction of pulmonary CT scans using adaptive statistical iterative reconstruction.

    Science.gov (United States)

    Honda, O; Yanagawa, M; Inoue, A; Kikuyama, A; Yoshida, S; Sumikawa, H; Tobino, K; Koyama, M; Tomiyama, N

    2011-04-01

    We investigated the image quality of multiplanar reconstruction (MPR) using adaptive statistical iterative reconstruction (ASIR). Inflated and fixed lungs were scanned with a garnet detector CT in high-resolution mode (HR mode) or non-high-resolution (HR) mode, and MPR images were then reconstructed. Observers compared 15 MPR images of ASIR (40%) and ASIR (80%) with those of ASIR (0%), and assessed image quality using a visual five-point scale (1, definitely inferior; 5, definitely superior), with particular emphasis on normal pulmonary structures, artefacts, noise and overall image quality. The mean overall image quality scores in HR mode were 3.67 with ASIR (40%) and 4.97 with ASIR (80%). Those in non-HR mode were 3.27 with ASIR (40%) and 3.90 with ASIR (80%). The mean artefact scores in HR mode were 3.13 with ASIR (40%) and 3.63 with ASIR (80%), but those in non-HR mode were 2.87 with ASIR (40%) and 2.53 with ASIR (80%). The mean scores of the other parameters were greater than 3, whereas those in HR mode were higher than those in non-HR mode. There were significant differences between ASIR (40%) and ASIR (80%) in overall image quality (pASIR did not suppress the severe artefacts of contrast medium. In general, MPR image quality with ASIR (80%) was superior to that with ASIR (40%). However, there was an increased incidence of artefacts by ASIR when CT images were obtained in non-HR mode.

  2. Multimodal imaging of heterogeneous polymers at the nanoscale by AFM and scanning near-field ellipsometric microscopy

    NARCIS (Netherlands)

    Cumurcu, Aysegul; Duvigneau, Joost; Lindsay, I.D.; Schön, Peter Manfred; Vancso, Gyula J.

    2013-01-01

    Scanning near field ellipsometric microscopy (SNEM) was used to simultaneously obtain optical images and tapping mode topography images of the microphase separated morphology of PS-b-P2VP block copolymer thin films. Optical images revealed a spatial resolution well below the diffraction limit. The

  3. First test model of the optical microscope which images the whole vertical particle tracks without any depth scanning

    International Nuclear Information System (INIS)

    Soroko, L.M.

    2001-01-01

    The first test model of the optical microscope which produces the in focus image of the whole vertical particle track without depth scanning is described. The in focus image of the object consisting of the linear array of the point-like elements was obtained. A comparison with primary out of focus image of such an object has been made

  4. Scanning Electron Microscope Calibration Using a Multi-Image Non-Linear Minimization Process

    Science.gov (United States)

    Cui, Le; Marchand, Éric

    2015-04-01

    A scanning electron microscope (SEM) calibrating approach based on non-linear minimization procedure is presented in this article. A part of this article has been published in IEEE International Conference on Robotics and Automation (ICRA), 2014. . Both the intrinsic parameters and the extrinsic parameters estimations are achieved simultaneously by minimizing the registration error. The proposed approach considers multi-images of a multi-scale calibration pattern view from different positions and orientations. Since the projection geometry of the scanning electron microscope is different from that of a classical optical sensor, the perspective projection model and the parallel projection model are considered and compared with distortion models. Experiments are realized by varying the position and the orientation of a multi-scale chessboard calibration pattern from 300× to 10,000×. The experimental results show the efficiency and the accuracy of this approach.

  5. Comparative evaluation of coronal images of the middle ear visualized by CT scan and polytomography

    International Nuclear Information System (INIS)

    Sugiyama, Masao; Nakai, Yoshiaki; Cho, Kansei; Tanabe, Kyoji; Inoue, Yuichi; Onoyama, Yasuto

    1982-01-01

    We retrospectively analysed the coronal images of the middle ear obtained by multidirectional tomography (polytomography) and computed tomography (CT) in 40 patients. Although CT was capable of demonstrating water density in the middle ear more clearly than polytomography and of delineating a lesion extending even outside of the petrous bone, the diagnostic capability was not much different between the two tomographic techniques. On the other hand, coronal CT scan has a disadvantage in that it usually has to be performed during hyperextension of the neck or while patients are in an uncomfortable hanging head position. We think that CT scan should be utilized only in case with a lesion extending beyond the petrous bone and/or is not well visualized by polytomography. (author)

  6. HIGH RESOLUTION AIRBORNE LASER SCANNING AND HYPERSPECTRAL IMAGING WITH A SMALL UAV PLATFORM

    Directory of Open Access Journals (Sweden)

    M. Gallay

    2016-06-01

    Full Text Available The capabilities of unmanned airborne systems (UAS have become diverse with the recent development of lightweight remote sensing instruments. In this paper, we demonstrate our custom integration of the state-of-the-art technologies within an unmanned aerial platform capable of high-resolution and high-accuracy laser scanning, hyperspectral imaging, and photographic imaging. The technological solution comprises the latest development of a completely autonomous, unmanned helicopter by Aeroscout, the Scout B1-100 UAV helicopter. The helicopter is powered by a gasoline two-stroke engine and it allows for integrating 18 kg of a customized payload unit. The whole system is modular providing flexibility of payload options, which comprises the main advantage of the UAS. The UAS integrates two kinds of payloads which can be altered. Both payloads integrate a GPS/IMU with a dual GPS antenna configuration provided by OXTS for accurate navigation and position measurements during the data acquisition. The first payload comprises a VUX-1 laser scanner by RIEGL and a Sony A6000 E-Mount photo camera. The second payload for hyperspectral scanning integrates a push-broom imager AISA KESTREL 10 by SPECIM. The UAS was designed for research of various aspects of landscape dynamics (landslides, erosion, flooding, or phenology in high spectral and spatial resolution.

  7. Muscle metastases: ultrasound and CT scan imaging in nine cases. Report on 9 cases

    International Nuclear Information System (INIS)

    Folinais, D.; Cluzel, Ph.; Blangy, S.; Sibert, A.; David, M.; Benacerraf, R.

    1988-01-01

    Clinical, ultrasound and CT scan examinations were carried out in 9 patients with secondary muscle lesions. All muscles can be affected but there was a marked predominance of psoas lesions (6 of the 9 cases). Two contrasting clinical pictures are seen. Secondary muscle tumors can occur during evolution of a known treated cancer (5 of the 9 cases), revealed usually by large, rarely painful, mass. CT scan imaging shows an heterogeneous mass taking up contrast and often partially necrotic, the lesions appearing hypoechogenic or heterogeneous on ultrasound exmination. Certain lesions can be totally necrotic. In some cases (4 of the 9 patients) the muscle metastases revealed the presence of a tumor. Symptomatology may be atypical and lead to a delay in diagnosis. Fine needle puncture biopsy can detect the secondary origin of the muscle lesion and also the primary tumor site (4 out of 9 cases), bronchopulmonary and colon cancer predominating. Images are however non-specific and in the absence of NMR imaging the muscle or lymph node metastases can be confused, although this has no practic consequences since treatment is identical [fr

  8. Scanning laser optical tomography for in toto imaging of the murine cochlea.

    Directory of Open Access Journals (Sweden)

    Lena Nolte

    Full Text Available The mammalian cochlea is a complex macroscopic structure due to its helical shape and the microscopic arrangements of the individual layers of cells. To improve the outcomes of hearing restoration in deaf patients, it is important to understand the anatomic structure and composition of the cochlea ex vivo. Hitherto, only one histological technique based on confocal laser scanning microscopy and optical clearing has been developed for in toto optical imaging of the murine cochlea. However, with a growing size of the specimen, e.g., human cochlea, this technique reaches its limitations. Here, we demonstrate scanning laser optical tomography (SLOT as a valuable imaging technique to visualize the murine cochlea in toto without any physical slicing. This technique can also be applied in larger specimens up to cm3 such as the human cochlea. Furthermore, immunolabeling allows visualization of inner hair cells (otoferlin or spiral ganglion cells (neurofilament within the whole cochlea. After image reconstruction, the 3D dataset was used for digital segmentation of the labeled region. As a result, quantitative analysis of position, length and curvature of the labeled region was possible. This is of high interest in order to understand the interaction of cochlear implants (CI and cells in more detail.

  9. Dose reduction for CT in children with cystic fibrosis: is it feasible to reduce the number of images per scan?

    International Nuclear Information System (INIS)

    Jong, Pim A. de; Tiddens, Harm A.W.M.; Nakano, Yasutaka; Lequin, Maarten H.

    2006-01-01

    Reducing the dose for each CT scan is important for children with cystic fibrosis (CF). To determine whether the number of CT images and therefore the dose per CT scan could be reduced without any significant loss of information in children with CF. A cohort of children with CF was followed with biennial surveillance CT scans, obtained in inspiration after a voluntary breath-hold as 1-mm thick images at 10-mm intervals from lung apex to base. A random set of 20 baseline CT scans and 10 follow-up CT scans were blinded. Sets of every image (10-mm intervals), every second image (20-mm intervals), every third image (30-mm intervals) and a selection of three and five images were scored randomly using a published CT scoring system by one experienced observer. The 20 subjects were 10 years of age with a range of 3.7-17.6 years at baseline. Fewer CT images resulted in a significantly lower (less abnormal) CT score and the number of patients positive for abnormalities decreased subsequently. At intervals greater than 20 mm no significant change in CT score over 2 years could be detected, while the CT scores at 10-mm (P=0.02) and 20-mm (P=0.02) intervals worsened significantly. A reduction in the number of inspiratory CT images by increasing the interval between images to greater than 10 mm is not a valid option for radiation dose reduction in children with CF. (orig.)

  10. The digital radiographic and computed tomography imaging of two types of explosive devices

    International Nuclear Information System (INIS)

    Galiano Riveros, Eduardo

    2002-01-01

    Two well-established medical imaging methods, digital radiography (DR) and computed tomography (CT), were employed to obtain images of two types of explosive devices, model rocket engines and shotgun shells. The images were evaluated from an airport security perspective. In terms of geometrical shape, the detection probability of the explosive devices appears to be higher with DR imaging, but in terms of the actual explosive compounds in the devices, CT appears to offer a higher detection probability. DR imaging offers a low detection probability for the explosive powder in the shotgun shells, but a rather significant detection probability for the explosive propellant in the model rocket engines

  11. Role of Early Postradiation Magnetic Resonance Imaging Scans in Children With Diffuse Intrinsic Pontine Glioma

    Energy Technology Data Exchange (ETDEWEB)

    Ko, Christine [Radiation Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD (United States); Kaushal, Aradhana, E-mail: kaushala@mail.nih.gov [Radiation Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD (United States); Hammoud, Dima A. [Radiology and Imaging Sciences, National Cancer Institute, National Institutes of Health, Bethesda, MD (United States); Steffen-Smith, Emilie A.; Bent, Robyn [Pediatric Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD (United States); Citrin, Deborah; Camphausen, Kevin [Radiation Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD (United States); Warren, Katherine E. [Pediatric Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD (United States)

    2012-07-15

    Purpose: To determine optimal timing of assessing postradiation radiographic response on magnetic resonance imaging (MRI) scans in pediatric patients with diffuse intrinsic pontine glioma (DIPG). Methods and Materials: Patients were treated on a prospective study at the National Cancer Institute (Protocol no. 06-C-0219) evaluating the effects of radiotherapy (RT). Standard RT was administered in standard fractionation over 6 weeks. Postradiation MRI scans were performed at 2 and 6-8 weeks. Results: Eleven patients with DIPG were evaluated. Median age was 6 years (range, 4-13 years). Patients were treated with external-beam RT to 55.8 Gy (n = 10) or 54 Gy (n = 1), with a gross tumor volume to planning target volume expansion of 1.8-2.0 cm. All patients received prescribed dose and underwent posttreatment MRI scans at 2 and 6-8 weeks. Pretreatment imaging revealed compression of fourth ventricle (n = 11); basilar artery encasement (n = 9); tumor extension outside the pons (n = 11); and tumor hemorrhage (n = 2). At the 2-week scan, basilar artery encasement improved in 7 of 9 patients, and extent of tumor was reduced in 5 of 11 patients. Fourth ventricle compression improved in 6 of 11 patients but worsened in 3 of 11 patients. Presumed necrosis was observed in 5 of 11 patients at 2 weeks and in 1 additional patient at 6-8 weeks. There was no significant difference in mean anteroposterior and transverse diameters of tumor between the 2- and 6-8-week time points. Six of 11 patients had increasing ventricular size, with no evidence of obstruction. Conclusions: There is no significant difference in tumor size of DIPG patients who have received standard RT when measured at 2 weeks vs. 6-8 weeks after RT. The majority of patients had the largest change in tumor size at the 2-week post-RT scan, with evolving changes documented on the 6-8-week scan. Six of 11 patients had progressive ventriculomegaly without obstruction, suggestive of communicating hydrocephalus. To the best

  12. Investigating the Role of Global Histogram Equalization Technique for 99mTechnetium-Methylene diphosphonate Bone Scan Image Enhancement.

    Science.gov (United States)

    Pandey, Anil Kumar; Sharma, Param Dev; Dheer, Pankaj; Parida, Girish Kumar; Goyal, Harish; Patel, Chetan; Bal, Chandrashekhar; Kumar, Rakesh

    2017-01-01

    99m Technetium-methylene diphosphonate ( 99m Tc-MDP) bone scan images have limited number of counts per pixel, and hence, they have inferior image quality compared to X-rays. Theoretically, global histogram equalization (GHE) technique can improve the contrast of a given image though practical benefits of doing so have only limited acceptance. In this study, we have investigated the effect of GHE technique for 99m Tc-MDP-bone scan images. A set of 89 low contrast 99m Tc-MDP whole-body bone scan images were included in this study. These images were acquired with parallel hole collimation on Symbia E gamma camera. The images were then processed with histogram equalization technique. The image quality of input and processed images were reviewed by two nuclear medicine physicians on a 5-point scale where score of 1 is for very poor and 5 is for the best image quality. A statistical test was applied to find the significance of difference between the mean scores assigned to input and processed images. This technique improves the contrast of the images; however, oversaturation was noticed in the processed images. Student's t -test was applied, and a statistically significant difference in the input and processed image quality was found at P histogram equalization technique in combination with some other postprocessing technique is useful.

  13. Fiber bundle probes for interconnecting miniaturized medical imaging devices

    Science.gov (United States)

    Zamora, Vanessa; Hofmann, Jens; Marx, Sebastian; Herter, Jonas; Nguyen, Dennis; Arndt-Staufenbiel, Norbert; Schröder, Henning

    2017-02-01

    Miniaturization of medical imaging devices will significantly improve the workflow of physicians in hospitals. Photonic integrated circuit (PIC) technologies offer a high level of miniaturization. However, they need fiber optic interconnection solutions for their functional integration. As part of European funded project (InSPECT) we investigate fiber bundle probes (FBPs) to be used as multi-mode (MM) to single-mode (SM) interconnections for PIC modules. The FBP consists of a set of four or seven SM fibers hexagonally distributed and assembled into a holder that defines a multicore connection. Such a connection can be used to connect MM fibers, while each SM fiber is attached to the PIC module. The manufacturing of these probes is explored by using well-established fiber fusion, epoxy adhesive, innovative adhesive and polishing techniques in order to achieve reliable, low-cost and reproducible samples. An innovative hydrofluoric acid-free fiber etching technology has been recently investigated. The preliminary results show that the reduction of the fiber diameter shows a linear behavior as a function of etching time. Different etch rate values from 0.55 μm/min to 2.3 μm/min were found. Several FBPs with three different type of fibers have been optically interrogated at wavelengths of 630nm and 1550nm. Optical losses are found of approx. 35dB at 1550nm for FBPs composed by 80μm fibers. Although FBPs present moderate optical losses, they might be integrated using different optical fibers, covering a broad spectral range required for imaging applications. Finally, we show the use of FBPs as promising MM-to-SM interconnects for real-world interfacing to PIC's.

  14. Modernization of a programmable scanning device used to develop remote inspection procedures related to the nondestructive examination of nuclear components

    International Nuclear Information System (INIS)

    Alencar, Donizete A.; Silva Junior, Silverio F.; Viana, Sadraque S.; Alves, Michel R.C.; Horta, Thamyris C.R.

    2011-01-01

    At CDTN's nondestructive test laboratory there is an electromechanical probe scanning device. That equipment is an important tool used in the development of procedures to be applied in remote inspections of nuclear equipment and components. In order to adequate its functionality an update was planned and executed. Keeping its excellent existing mechanical parts and DC motors, the original electronic power supply and the control unit was replaced by a new one. Furthermore, trajectory control and data processing algorithms were implemented by means of National Instruments LabVIEW 8.6 programming tool. So, both trajectory control and data acquisition/plotting systems were integrated as PC executable software. This paper presents details of the whole process, including the updated hardware, some screen shots showing the trajectory control program and a typical data presentation window. (author)

  15. Modernization of a programmable scanning device used to develop remote inspection procedures related to the nondestructive examination of nuclear components

    Energy Technology Data Exchange (ETDEWEB)

    Alencar, Donizete A.; Silva Junior, Silverio F., E-mail: daa@cdtn.b, E-mail: silvasf@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Viana, Sadraque S.; Alves, Michel R.C.; Horta, Thamyris C.R. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Engenharia Eletronica

    2011-07-01

    At CDTN's nondestructive test laboratory there is an electromechanical probe scanning device. That equipment is an important tool used in the development of procedures to be applied in remote inspections of nuclear equipment and components. In order to adequate its functionality an update was planned and executed. Keeping its excellent existing mechanical parts and DC motors, the original electronic power supply and the control unit was replaced by a new one. Furthermore, trajectory control and data processing algorithms were implemented by means of National Instruments LabVIEW 8.6 programming tool. So, both trajectory control and data acquisition/plotting systems were integrated as PC executable software. This paper presents details of the whole process, including the updated hardware, some screen shots showing the trajectory control program and a typical data presentation window. (author)

  16. The quality of reconstructed 3D images in multidetector-row helical CT: experimental study involving scan parameters

    International Nuclear Information System (INIS)

    Shin, Ji Hoon; Lee, Ho Kyu; Choi, Choong Gon; Suh, Dae Chul; Lim, Tae Hwan; Kang, Weechang

    2002-01-01

    To determine which multidetector-row helical CT scanning technique provides the best-quality reconstructed 3D images, and to assess differences in image quality according to the levels of the scanning parameters used. Four objects with different surfaces and contours were scanned using multidetector-row helical CT at three detector-row collimations (1.25, 2.50, 5.00 mm), two pitches (3.0, 6.0), and three different degrees of overlap between the reconstructed slices (0%, 25%, 50%). Reconstructed 3D images of the resulting 72 sets of data were produced using volumetric rendering. The 72 images were graded on a scale from 1 (worst) to 5 (best) for each of four rating criteria, giving a mean score for each criterion and an overall mean score. Statistical analysis was used to assess differences in image quality according to scanning parameter levels. The mean score for each rating criterion, and the overall mean score, varied significantly according to the scanning parameter levels used. With regard to detector-row collimation and pitch, all levels of scanning parameters gave rise to significant differences, while in the degree of overlap of reconstructed slices, there were significant differences between overlap of 0% and of 50% in all levels of scanning parameters, and between overlap of 25% and of 50% in overall accuracy and overall mean score. Among the 18 scanning sequences, the highest score (4.94) was achieved with 1.25 mm detector-row collimation, 3.0 pitch, and 50% overlap between reconstructed slices. Comparison of the quality of reconstructed 3D images obtained using multidetector-row helical CT and various scanning techniques indicated that the 1.25 mm, 3.0, 50% scanning sequence was best. Quality improved as detector-row collimation decreased; as pitch was reduced from 6.0 to 3.0; and as overlap between reconstructed slices increased

  17. Scanning tunnelling microscope imaging of nanoscale electron density gradients on the surface of GaAs

    International Nuclear Information System (INIS)

    Hamilton, B; Jacobs, J; Missous, M

    2003-01-01

    This paper is concerned with the scanning tunnelling microscope tunnelling conditions needed to produce constant current images dominated either by surface topology or by electronic effects. A model experimental structure was produced by cleaving a GaAs multiδ-doped layer in UHV and so projecting a spatially varying electron gas density onto the (110) surface. This cross sectional electron density varies on a nanometre scale in the [100] growth direction. The electronic structure and tunnelling properties of this system were modelled, and the tunnelling conditions favouring sensitivity to the surface electron gas density determined

  18. Colour measurements of pigmented rice grain using flatbed scanning and image analysis

    Science.gov (United States)

    Kaisaat, Khotchakorn; Keawdonree, Nuttapong; Chomkokard, Sakchai; Jinuntuya, Noparit; Pattanasiri, Busara

    2017-09-01

    Recently, the National Bureau of Agricultural Commodity and Food Standards (ACFS) have drafted a manual of Thai colour rice standards. However, there are no quantitative descriptions of rice colour and its measurement method. These drawbacks might lead to misunderstanding for people who use the manual. In this work, we proposed an inexpensive method, using flatbed scanning together with image analysis, to quantitatively measure rice colour and colour uniformity. To demonstrate its general applicability for colour differentiation of rice, we applied it to different kinds of pigmented rice, including Riceberry rice with and without uniform colour and Chinese black rice.

  19. Documenting Bronze Age Akrotiri on Thera Using Laser Scanning, Image-Based Modelling and Geophysical Prospection

    Science.gov (United States)

    Trinks, I.; Wallner, M.; Kucera, M.; Verhoeven, G.; Torrejón Valdelomar, J.; Löcker, K.; Nau, E.; Sevara, C.; Aldrian, L.; Neubauer, E.; Klein, M.

    2017-02-01

    The excavated architecture of the exceptional prehistoric site of Akrotiri on the Greek island of Thera/Santorini is endangered by gradual decay, damage due to accidents, and seismic shocks, being located on an active volcano in an earthquake-prone area. Therefore, in 2013 and 2014 a digital documentation project has been conducted with support of the National Geographic Society in order to generate a detailed digital model of Akrotiri's architecture using terrestrial laser scanning and image-based modeling. Additionally, non-invasive geophysical prospection has been tested in order to investigate its potential to explore and map yet buried archaeological remains. This article describes the project and the generated results.

  20. Automatic registration of panoramic image sequence and mobile laser scanning data using semantic features

    Science.gov (United States)

    Li, Jianping; Yang, Bisheng; Chen, Chi; Huang, Ronggang; Dong, Zhen; Xiao, Wen

    2018-02-01

    Inaccurate exterior orientation parameters (EoPs) between sensors obtained by pre-calibration leads to failure of registration between panoramic image sequence and mobile laser scanning data. To address this challenge, this paper proposes an automatic registration method based on semantic features extracted from panoramic images and point clouds. Firstly, accurate rotation parameters between the panoramic camera and the laser scanner are estimated using GPS and IMU aided structure from motion (SfM). The initial EoPs of panoramic images are obtained at the same time. Secondly, vehicles in panoramic images are extracted by the Faster-RCNN as candidate primitives to be matched with potential corresponding primitives in point clouds according to the initial EoPs. Finally, translation between the panoramic camera and the laser scanner is refined by maximizing the overlapping area of corresponding primitive pairs based on the Particle Swarm Optimization (PSO), resulting in a finer registration between panoramic image sequences and point clouds. Two challenging urban scenes were experimented to assess the proposed method, and the final registration errors of these two scenes were both less than three pixels, which demonstrates a high level of automation, robustness and accuracy.

  1. Three-dimensional imaging of porous media using confocal laser scanning microscopy.

    Science.gov (United States)

    Shah, S M; Crawshaw, J P; Boek, E S

    2017-02-01

    In the last decade, imaging techniques capable of reconstructing three-dimensional (3-D) pore-scale model have played a pivotal role in the study of fluid flow through complex porous media. In this study, we present advances in the application of confocal laser scanning microscopy (CLSM) to image, reconstruct and characterize complex porous geological materials with hydrocarbon reservoir and CO 2 storage potential. CLSM has a unique capability of producing 3-D thin optical sections of a material, with a wide field of view and submicron resolution in the lateral and axial planes. However, CLSM is limited in the depth (z-dimension) that can be imaged in porous materials. In this study, we introduce a 'grind and slice' technique to overcome this limitation. We discuss the practical and technical aspects of the confocal imaging technique with application to complex rock samples including Mt. Gambier and Ketton carbonates. We then describe the complete workflow of image processing to filtering and segmenting the raw 3-D confocal volumetric data into pores and grains. Finally, we use the resulting 3-D pore-scale binarized confocal data obtained to quantitatively determine petrophysical pore-scale properties such as total porosity, macro- and microporosity and single-phase permeability using lattice Boltzmann (LB) simulations, validated by experiments. © 2016 The Authors Journal of Microscopy © 2016 Royal Microscopical Society.

  2. A statistical pixel intensity model for segmentation of confocal laser scanning microscopy images.

    Science.gov (United States)

    Calapez, Alexandre; Rosa, Agostinho

    2010-09-01

    Confocal laser scanning microscopy (CLSM) has been widely used in the life sciences for the characterization of cell processes because it allows the recording of the distribution of fluorescence-tagged macromolecules on a section of the living cell. It is in fact the cornerstone of many molecular transport and interaction quantification techniques where the identification of regions of interest through image segmentation is usually a required step. In many situations, because of the complexity of the recorded cellular structures or because of the amounts of data involved, image segmentation either is too difficult or inefficient to be done by hand and automated segmentation procedures have to be considered. Given the nature of CLSM images, statistical segmentation methodologies appear as natural candidates. In this work we propose a model to be used for statistical unsupervised CLSM image segmentation. The model is derived from the CLSM image formation mechanics and its performance is compared to the existing alternatives. Results show that it provides a much better description of the data on classes characterized by their mean intensity, making it suitable not only for segmentation methodologies with known number of classes but also for use with schemes aiming at the estimation of the number of classes through the application of cluster selection criteria.

  3. Error estimation of deformable image registration of pulmonary CT scans using convolutional neural networks.

    Science.gov (United States)

    Eppenhof, Koen A J; Pluim, Josien P W

    2018-04-01

    Error estimation in nonlinear medical image registration is a nontrivial problem that is important for validation of registration methods. We propose a supervised method for estimation of registration errors in nonlinear registration of three-dimensional (3-D) images. The method is based on a 3-D convolutional neural network that learns to estimate registration errors from a pair of image patches. By applying the network to patches centered around every voxel, we construct registration error maps. The network is trained using a set of representative images that have been synthetically transformed to construct a set of image pairs with known deformations. The method is evaluated on deformable registrations of inhale-exhale pairs of thoracic CT scans. Using ground truth target registration errors on manually annotated landmarks, we evaluate the method's ability to estimate local registration errors. Estimation of full domain error maps is evaluated using a gold standard approach. The two evaluation approaches show that we can train the network to robustly estimate registration errors in a predetermined range, with subvoxel accuracy. We achieved a root-mean-square deviation of 0.51 mm from gold standard registration errors and of 0.66 mm from ground truth landmark registration errors.

  4. A system architecture for sharing de-identified, research-ready brain scans and health information across clinical imaging centers.

    Science.gov (United States)

    Chervenak, Ann L; van Erp, Theo G M; Kesselman, Carl; D'Arcy, Mike; Sobell, Janet; Keator, David; Dahm, Lisa; Murry, Jim; Law, Meng; Hasso, Anton; Ames, Joseph; Macciardi, Fabio; Potkin, Steven G

    2012-01-01

    Progress in our understanding of brain disorders increasingly relies on the costly collection of large standardized brain magnetic resonance imaging (MRI) data sets. Moreover, the clinical interpretation of brain scans benefits from compare and contrast analyses of scans from patients with similar, and sometimes rare, demographic, diagnostic, and treatment status. A solution to both needs is to acquire standardized, research-ready clinical brain scans and to build the information technology infrastructure to share such scans, along with other pertinent information, across hospitals. This paper describes the design, deployment, and operation of a federated imaging system that captures and shares standardized, de-identified clinical brain images in a federation across multiple institutions. In addition to describing innovative aspects of the system architecture and our initial testing of the deployed infrastructure, we also describe the Standardized Imaging Protocol (SIP) developed for the project and our interactions with the Institutional Review Board (IRB) regarding handling patient data in the federated environment.

  5. Basic dose response of fluorescent screen-based portal imaging device

    International Nuclear Information System (INIS)

    Yeo, In Hwan; Yonannes, Yonas; Zhu, Yunping

    1999-01-01

    The purpose of this study is to investigate fundamental aspects of the dose response of fluorescent screen-based electronic portal imaging devices (EPIDs). We acquired scanned signal across portal planes as we varied the radiation that entered the EPID by changing the thickness and anatomy of the phantom as well as the air gap between the phantom and the EPID. In addition, we simulated the relative contribution of the scintillation light signal in the EPID system. We have shown that the dose profile across portal planes is a function of the air gap and phantom thickness. We have also found that depending on the density change within the phantom geometry, errors associated with dose response based on the EPID scan can be as high as 7%. We also found that scintillation light scattering within the EPID system is an important source of error. This study revealed and demonstrated fundamental characteristics of dose response of EPID, as relative to that of ion chambers. This study showed that EPID based on fluorescent screen cannot be an accurate dosimetry system

  6. Frequent Computed Tomography Scanning Due to Incomplete Three-View X-Ray Imaging of the Cervical Spine

    NARCIS (Netherlands)

    Saltzherr, Teun Peter; Beenen, Ludo F. M.; Reitsma, Johannes B.; Luitse, Jan S. K.; Vandertop, W. Peter; Goslings, J. Carel

    2010-01-01

    Background: Conventional C-spine imaging (3-view series) is still widely used in trauma patients, although the utilization of computed tomography (CT) scanning is increasing. The aim of this study was to analyze the value of conventional radiography and the frequency of subsequent CT scanning due to

  7. Initial Clinical Experience Performing Patient Treatment Verification With an Electronic Portal Imaging Device Transit Dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Berry, Sean L., E-mail: BerryS@MSKCC.org [Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York (United States); Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Polvorosa, Cynthia; Cheng, Simon; Deutsch, Israel; Chao, K. S. Clifford; Wuu, Cheng-Shie [Department of Radiation Oncology, Columbia University, New York, New York (United States)

    2014-01-01

    Purpose: To prospectively evaluate a 2-dimensional transit dosimetry algorithm's performance on a patient population and to analyze the issues that would arise in a widespread clinical adoption of transit electronic portal imaging device (EPID) dosimetry. Methods and Materials: Eleven patients were enrolled on the protocol; 9 completed and were analyzed. Pretreatment intensity modulated radiation therapy (IMRT) patient-specific quality assurance was performed using a stringent local 3%, 3-mm γ criterion to verify that the planned fluence had been appropriately transferred to and delivered by the linear accelerator. Transit dosimetric EPID images were then acquired during treatment and compared offline with predicted transit images using a global 5%, 3-mm γ criterion. Results: There were 288 transit images analyzed. The overall γ pass rate was 89.1% ± 9.8% (average ± 1 SD). For the subset of images for which the linear accelerator couch did not interfere with the measurement, the γ pass rate was 95.7% ± 2.4%. A case study is presented in which the transit dosimetry algorithm was able to identify that a lung patient's bilateral pleural effusion had resolved in the time between the planning CT scan and the treatment. Conclusions: The EPID transit dosimetry algorithm under consideration, previously described and verified in a phantom study, is feasible for use in treatment delivery verification for real patients. Two-dimensional EPID transit dosimetry can play an important role in indicating when a treatment delivery is inconsistent with the original plan.

  8. Reduction of Cone-Beam CT scan time without compromising the accuracy of the image registration in IGRT

    DEFF Research Database (Denmark)

    Westberg, Jonas; Jensen, Henrik R; Bertelsen, Anders

    2010-01-01

    In modern radiotherapy accelerators are equipped with 3D cone-beam CT (CBCT) which is used to verify patient position before treatment. The verification is based on an image registration between the CBCT acquired just before treatment and the CT scan made for the treatment planning. The purpose...... of this study is to minimise the scan time of the CBCT without compromising the accuracy of the image registration in IGRT....

  9. Imaging sequential dehydrogenation of methanol on Cu(110) with a scanning tunneling microscope.

    Science.gov (United States)

    Kitaguchi, Y; Shiotari, A; Okuyama, H; Hatta, S; Aruga, T

    2011-05-07

    Adsorption of methanol and its dehydrogenation on Cu(110) were studied by using a scanning tunneling microscope (STM). Upon adsorption at 12 K, methanol preferentially forms clusters on the surface. The STM could induce dehydrogenation of methanol sequentially to methoxy and formaldehyde. This enabled us to study the binding structures of these products in a single-molecule limit. Methoxy was imaged as a pair of protrusion and depression along the [001] direction. This feature is fully consistent with the previous result that it adsorbs on the short-bridge site with the C-O axis tilted along the [001] direction. The axis was induced to flip back and forth by vibrational excitations with the STM. Two configurations were observed for formaldehyde, whose structures were proposed based on their characteristic images and motions.

  10. Large area strain analysis using scanning transmission electron microscopy across multiple images

    International Nuclear Information System (INIS)

    Oni, A. A.; Sang, X.; LeBeau, J. M.; Raju, S. V.; Saxena, S.; Dumpala, S.; Broderick, S.; Rajan, K.; Kumar, A.; Sinnott, S.

    2015-01-01

    Here, we apply revolving scanning transmission electron microscopy to measure lattice strain across a sample using a single reference area. To do so, we remove image distortion introduced by sample drift, which usually restricts strain analysis to a single image. Overcoming this challenge, we show that it is possible to use strain reference areas elsewhere in the sample, thereby enabling reliable strain mapping across large areas. As a prototypical example, we determine the strain present within the microstructure of a Ni-based superalloy directly from atom column positions as well as geometric phase analysis. While maintaining atomic resolution, we quantify strain within nanoscale regions and demonstrate that large, unit-cell level strain fluctuations are present within the intermetallic phase

  11. Adaptive optics scanning laser ophthalmoscopy in fundus imaging, a review and update

    Directory of Open Access Journals (Sweden)

    Bing Zhang

    2017-11-01

    Full Text Available Adaptive optics scanning laser ophthalmoscopy (AO-SLO has been a promising technique in funds imaging with growing popularity. This review firstly gives a brief history of adaptive optics (AO and AO-SLO. Then it compares AO-SLO with conventional imaging methods (fundus fluorescein angiography, fundus autofluorescence, indocyanine green angiography and optical coherence tomography and other AO techniques (adaptive optics flood-illumination ophthalmoscopy and adaptive optics optical coherence tomography. Furthermore, an update of current research situation in AO-SLO is made based on different fundus structures as photoreceptors (cones and rods, fundus vessels, retinal pigment epithelium layer, retinal nerve fiber layer, ganglion cell layer and lamina cribrosa. Finally, this review indicates possible research directions of AO-SLO in future.

  12. Scanning electron microscope cathodoluminescence imaging of subgrain boundaries, twins and planar deformation features in quartz

    Science.gov (United States)

    Hamers, M. F.; Pennock, G. M.; Drury, M. R.

    2017-04-01

    The study of deformation features has been of great importance to determine deformation mechanisms in quartz. Relevant microstructures in both growth and deformation processes include dislocations, subgrains, subgrain boundaries, Brazil and Dauphiné twins and planar deformation features (PDFs). Dislocations and twin boundaries are most commonly imaged using a transmission electron microscope (TEM), because these cannot directly be observed using light microscopy, in contrast to PDFs. Here, we show that red-filtered cathodoluminescence imaging in a scanning electron microscope (SEM) is a useful method to visualise subgrain boundaries, Brazil and Dauphiné twin boundaries. Because standard petrographic thin sections can be studied in the SEM, the observed structures can be directly and easily correlated to light microscopy studies. In contrast to TEM preparation methods, SEM techniques are non-destructive to the area of interest on a petrographic thin section.

  13. Improved image quality and radiation dose reduction in liver dynamic CT scan with the protocol change

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Yu Jin; Cho, Pyong Kon [Radiological Science, Catholic University of Daegu, Daegu (Korea, Republic of)

    2015-06-15

    The purpose is reducing radiation dose while maintaining of image quality in liver dynamic CT(LDCT) scan, by protocols generally used and the tube voltage set at a low level protocol compared to the radiation dose and image quality. The target is body mass index, 18.5-24 patients out of 40 patients who underwent the ACT(abdominal CT). Group A(tube voltage : 120 kVp, SAFIRE strength 1) of 20 people among 40 people, to apply the general abdominal CT scan protocol, group B(tube voltage : 100 kVp, apply SAFIRE strength 0-5) was 20 people, set a lower tube voltage. Image quality evaluation was setting a region of interest(ROI) in the liver parenchyma, aorta, superior mesenteric artery (SMA), celiac trunk, visceral fat of arterial phase. In the ROI were compared by measuring the noise, signal to noise ratio(SNR), contrast to noise ratio(CNR), CT number. In addition, qualitative assessments to evaluate two people in the rich professional experience in Radiology by 0-3 points. We compared the total radiation dose, dose length product(DLP) and effective dose, volume computed tomography dose index(CTDIvol). The higher SAFIRE in the tube voltage 100 kVp, noise is reduced, CT number was increased. Thus, SNR and CNR was increased higher the SAFIRE step. Compared with the tube voltage 120 kVp, noise, SNR, CNR was most similar in SAFIRE strength 2 and 3. Qualitative assessment SAFIRE strength 2 is the most common SAFIRE strength 2 the most common qualitative assessment, if the tube voltage of 100 kVp when the quality of the images better evaluated was SAFIRE strength 1. Dose was reduced from 21.69%, in 100 kVp than 120 kVp. In the case of a relatively high BMI is not LDCT scan, When it is shipped from the factory tube voltage is set higher, unnecessary radiation exposure when considering the reality that is concerned, when according to the results of this study, set a lower tube voltage and adjust the SAFIRE strength to 1 or 2, the radiation without compromising image quality

  14. Three-dimensional-CT imaging of colorectal disease with thin collimation helical CT scanning

    International Nuclear Information System (INIS)

    Ogura, Toshihiro; Koizumi, Koichi; Sakai, Tatsuya; Kai, Shunkichi; Takatsu, Kazuaki; Maruyama, Masakazu

    1998-01-01

    We have conducted research on three-dimensional (3D)-CT-colonoscopy with thin collimation helical CT scanning over the past three years. This has lately become a subject of special interest. 3D-CT-colonoscopy has three kinds of visualizing methods depending on the threshold setting of CT values. The first one is the virtual endoscopy method which is displayed in a similar fashion to colonoscopic images. The second one is the air image method using the air in the digestive tract as a contrast medium. The third one is the pseudo-tract method which has characteristics of both virtual endoscopy and the air image method and visualizes in a shape of the digestive tract. The image visualized by 3D-CT-colonoscopy is similar to that of conventional colonoscopy and barium enema study, which is obtained with minimal invasion to patients. Obvious advanced carcinomas were easily visualized, and even a small flat polyp measuring 5 mm in size, was able to be observed retrospectively. The characteristics of our method are that we can easily make an examination in a short time and with little dependence on expert technique. Also patients have little discomfort compared to that experienced during colonoscopy and barium enema study. Important features are as follows; long calculation time, insufficient air insufflation, fecal material in the patient''s bowel, whole abdominal scan, and spatial resolution. In the near future, a multislice CT scanner system will have ability to overcome these problems. Therefore, 3D-CT-colonoscopy might be applied in the future for first line examination as a mass screening for colorectal carcinoma. (author)

  15. Applying deep learning technology to automatically identify metaphase chromosomes using scanning microscopic images: an initial investigation

    Science.gov (United States)

    Qiu, Yuchen; Lu, Xianglan; Yan, Shiju; Tan, Maxine; Cheng, Samuel; Li, Shibo; Liu, Hong; Zheng, Bin

    2016-03-01

    Automated high throughput scanning microscopy is a fast developing screening technology used in cytogenetic laboratories for the diagnosis of leukemia or other genetic diseases. However, one of the major challenges of using this new technology is how to efficiently detect the analyzable metaphase chromosomes during the scanning process. The purpose of this investigation is to develop a computer aided detection (CAD) scheme based on deep learning technology, which can identify the metaphase chromosomes with high accuracy. The CAD scheme includes an eight layer neural network. The first six layers compose of an automatic feature extraction module, which has an architecture of three convolution-max-pooling layer pairs. The 1st, 2nd and 3rd pair contains 30, 20, 20 feature maps, respectively. The seventh and eighth layers compose of a multiple layer perception (MLP) based classifier, which is used to identify the analyzable metaphase chromosomes. The performance of new CAD scheme was assessed by receiver operation characteristic (ROC) method. A number of 150 regions of interest (ROIs) were selected to test the performance of our new CAD scheme. Each ROI contains either interphase cell or metaphase chromosomes. The results indicate that new scheme is able to achieve an area under the ROC curve (AUC) of 0.886+/-0.043. This investigation demonstrates that applying a deep learning technique may enable to significantly improve the accuracy of the metaphase chromosome detection using a scanning microscopic imaging technology in the future.

  16. A scanning Hall probe microscope for high resolution magnetic imaging down to 300 mK

    International Nuclear Information System (INIS)

    Khotkevych, V. V.; Bending, S. J.; Milosevic, M. V.

    2008-01-01

    We present the design, construction, and performance of a low-temperature scanning Hall probe microscope with submicron lateral resolution and a large scanning range. The detachable microscope head is mounted on the cold flange of a commercial 3 He-refrigerator (Oxford Instruments, Heliox VT-50) and operates between room temperature and 300 mK. It is fitted with a three-axis slip-stick nanopositioner that enables precise in situ adjustment of the probe location within a 6x6x7 mm 3 space. The local magnetic induction at the sample surface is mapped with an easily changeable microfabricated Hall probe [typically GsAs/AlGaAs or AlGaAs/InGaAs/GaAs Hall sensors with integrated scanning tunnel microscopy (STM) tunneling tips] and can achieve minimum detectable fields ≥10 mG/Hz 1/2 . The Hall probe is brought into very close proximity to the sample surface by sensing and controlling tunnel currents at the integrated STM tip. The instrument is capable of simultaneous tunneling and Hall signal acquisition in surface-tracking mode. We illustrate the potential of the system with images of superconducting vortices at the surface of a Nb thin film down to 372 mK, and also of labyrinth magnetic-domain patterns of an yttrium iron garnet film captured at room temperature.

  17. 77 FR 31875 - Certain Electronic Imaging Devices; Notice of Receipt of Complaint; Solicitation of Comments...

    Science.gov (United States)

    2012-05-30

    ... INTERNATIONAL TRADE COMMISSION [Docket No. 2898] Certain Electronic Imaging Devices; Notice of... Trade Commission. ACTION: Notice. SUMMARY: Notice is hereby given that the U.S. International Trade Commission has received a complaint entitled Certain Electronic Imaging Devices, DN 2898; the Commission is...

  18. 77 FR 32995 - Certain Electronic Imaging Devices Corrected: Notice of Receipt of Complaint; Solicitation of...

    Science.gov (United States)

    2012-06-04

    ... INTERNATIONAL TRADE COMMISSION [Docket No. 2898] Certain Electronic Imaging Devices Corrected.... International Trade Commission. ACTION: Notice. SUMMARY: Notice is hereby given that the U.S. International Trade Commission has received a complaint entitled Certain Electronic Imaging Devices, DN 2898; the...

  19. Scan time reduction in {sup 23}Na-Magnetic Resonance Imaging using the chemical shift imaging sequence. Evaluation of an iterative reconstruction method

    Energy Technology Data Exchange (ETDEWEB)

    Weingaertner, Sebastian; Konstandin, Simon; Schad, Lothar R. [Heidelberg Univ., Mannheim (Germany). Computer Assisted Clinical Medicine; Wetterling, Friedrich [Heidelberg Univ., Mannheim (Germany). Computer Assisted Clinical Medicine; Dublin Univ. (Ireland) Trinity Inst. of Neuroscience; Fatar, Marc [Heidelberg Univ., Mannheim (Germany). Dept. of Neurology; Neumaier-Probst, Eva [Heidelberg Univ., Mannheim (Germany). Dept. of Neuroradiology

    2015-07-01

    To evaluate potential scan time reduction in {sup 23}Na-Magnetic Resonance Imaging with the chemical shift imaging sequence (CSI) using undersampled data of high-quality datasets, reconstructed with an iterative constrained reconstruction, compared to reduced resolution or reduced signal-to-noise ratio. CSI {sup 23}Na-images were retrospectively undersampled and reconstructed with a constrained reconstruction scheme. The results were compared to conventional methods of scan time reduction. The constrained reconstruction scheme used a phase constraint and a finite object support, which was extracted from a spatially registered {sup 1}H-image acquired with a double-tuned coil. The methods were evaluated using numerical simulations, phantom images and in-vivo images of a healthy volunteer and a patient who suffered from cerebral ischemic stroke. The constrained reconstruction scheme showed improved image quality compared to a decreased number of averages, images with decreased resolution or circular undersampling with weighted averaging for any undersampling factor. Brain images of a stroke patient, which were reconstructed from three-fold undersampled k-space data, resulted in only minor differences from the original image (normalized root means square error < 12%) and an almost identical delineation of the stroke region (mismatch < 6%). The acquisition of undersampled {sup 23}Na-CSI images enables up to three-fold scan time reduction with improved image quality compared to conventional methods of scan time saving.

  20. Central venous device-related thrombosis as imaged with MDCT in oncologic patients: prevalence and findings

    International Nuclear Information System (INIS)

    Catalano, Orlando; Castelguidone, Elisabetta de Lutio di; Granata, Vincenza; D'Errico, Adolfo Gallipoli; Sandomenico, Claudia; Petrillo, Mario; Aprea, Pasquale

    2011-01-01

    Background: Venous thrombosis is a common occurrence in cancer patients, developing spontaneously or in combination with indwelling central venous devices (CVD). Purpose: To analyze the multidetector CT (MDCT) prevalence, appearance, and significance of catheter related thoracic venous thrombosis in oncologic patients and to determine the percentage of thrombi identified in the original reports. Material and Methods: Five hundred consecutive patients were considered. Inclusion criteria were: presence of a CVD; availability of a contrast-enhanced MDCT; and cancer history. Exclusion criteria were: direct tumor compression/infiltration of the veins; poor image quality; device tip not in the scanned volume; and missing clinical data. Seventeen (3.5%) out of the final 481 patients had a diagnosis of venous thrombosis. Results: Factors showing the highest correlation with thrombosis included peripherally-inserted CVD, right brachiocephalic vein tip location, patient performance status 3, metastatic stage disease, ongoing chemotherapy, and longstanding CVD. The highest prevalence was in patients with lymphoma, lung carcinoma, melanoma, and gynecologic malignancies. Eleven out of 17 cases had not been identified in the original report. Conclusion: CVD-related thrombosis is not uncommon in cancer patients and can also be observed in outpatients with a good performance status and a non-metastatic disease. Thrombi can be very tiny. Radiologists should be aware of the possibility to identify (or overlook) small thrombi

  1. Evaluation of image quality for various electronic portal imaging devices in radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Son, Soon Yong; Choi, Kwan Woo [Dept. of Radiology, Asan Medical Center, Seoul (Korea, Republic of); Kim, Jung Min [Dept. of College of Health Science, Radiologic Science, Korea University, Seoul (Korea, Republic of); and others

    2015-12-15

    In megavoltage (MV) radiotherapy, delivering the dose to the target volume is important while protecting the surrounding normal tissue. The purpose of this study was to evaluate the modulation transfer function (MTF), the noise power spectrum (NPS), and the detective quantum efficiency (DQE) using an edge block in megavoltage X-ray imaging (MVI). We used an edge block, which consists of tungsten with dimensions of 19 (thickness) × 10 (length) × 1 (width) cm3 and measured the pre-sampling MTF at 6 MV energy. Various radiation therapy (RT) devices such as TrueBeamTM (Varian), BEAMVIEWPLUS (Siemens), iViewGT (Elekta) and Clinac®iX (Varian) were used. As for MTF results, TrueBeamTM(Varian) flattening filter free(FFF) showed the highest values of 0.46 mm-1and1.40mm-1for MTF 0.5 and 0.1. In NPS, iViewGT (Elekta) showed the lowest noise distribution. In DQE, iViewGT (Elekta) showed the best efficiency at a peak DQE and 1 mm-1DQE of 0.0026 and 0.00014, respectively. This study could be used not only for traditional QA imaging but also for quantitative MTF, NPS, and DQE measurement for development of an electronic portal imaging device (EPID)

  2. Terrestrial scanning or digital images in inventory of monumental objects? - case study

    Science.gov (United States)

    Markiewicz, J. S.; Zawieska, D.

    2014-06-01

    Cultural heritage is the evidence of the past; monumental objects create the important part of the cultural heritage. Selection of a method to be applied depends on many factors, which include: the objectives of inventory, the object's volume, sumptuousness of architectural design, accessibility to the object, required terms and accuracy of works. The paper presents research and experimental works, which have been performed in the course of development of architectural documentation of elements of the external facades and interiors of the Wilanów Palace Museum in Warszawa. Point clouds, acquired from terrestrial laser scanning (Z+F 5003h) and digital images taken with Nikon D3X and Hasselblad H4D cameras were used. Advantages and disadvantages of utilisation of these technologies of measurements have been analysed with consideration of the influence of the structure and reflectance of investigated monumental surfaces on the quality of generation of photogrammetric products. The geometric quality of surfaces obtained from terrestrial laser scanning data and from point clouds resulting from digital images, have been compared.

  3. Automatic segmentation of cell nuclei from confocal laser scanning microscopy images

    International Nuclear Information System (INIS)

    Kelemen, A.; Reist, H.W.

    1997-01-01

    A newly developed experimental method combines the possibility of irradiating more than a thousand cells simultaneous with an efficient colony-forming ability and with the capability of localizing a particle track through a cell nucleus together with the assessment of the energy transfer by digital superposition of the image containing the track with that of the cells. To assess the amount of energy deposition by particles traversing the cell nucleus the intersection lengths of the particle tracks have to be known. Intersection lengths can be obtained by determining the 3D surface contours of the irradiated cell nuclei. Confocal laser scanning microscopy using specific DNA fluorescent dye offers a possible way for the determination of the 3D shape of individual nuclei. Unfortunately, such experiments cannot be performed on living cells. One solution to this problem can be provided by building a statistical model of the shape of the nuclei of the exposed cells. In order to build such a statistical model, a large number of cell nuclei have to be identified and segmented from confocal laser scanning microscopy images. The present paper describes a method to perform this 3D segmentation in an automatic manner in order to create a solid basis for the statistical model. (author) 2 figs., 4 refs

  4. Examination of Scanning Electron Microscope and Computed Tomography Images of PICA

    Science.gov (United States)

    Lawson, John W.; Stackpoole, Margaret M.; Shklover, Valery

    2010-01-01

    Micrographs of PICA (Phenolic Impregnated Carbon Ablator) taken using a Scanning Electron Microscope (SEM) and 3D images taken with a Computed Tomography (CT) system are examined. PICA is a carbon fiber based composite (Fiberform ) with a phenolic polymer matrix. The micrographs are taken at different surface depths and at different magnifications in a sample after arc jet testing and show different levels of oxidative removal of the charred matrix (Figs 1 though 13). CT scans, courtesy of Xradia, Inc. of Concord CA, were captured for samples of virgin PICA, charred PICA and raw Fiberform (Fig. 14). We use these images to calculate the thermal conductivity (TC) of these materials using correlation function (CF) methods. CF methods give a mathematical description of how one material is embedded in another and is thus ideally suited for modeling composites like PICA. We will evaluate how the TC of the materials changes as a function of surface depth. This work is in collaboration with ETH-Zurich, which has expertise in high temperature materials and TC modeling (including CF methods).

  5. Utilization of an electronic portal imaging device for measurement of dynamic wedge data

    International Nuclear Information System (INIS)

    Elder, Eric S.; Miner, Marc S.; Butker, Elizabeth K.; Sutton, Danny S.; Davis, Lawrence W.

    1996-01-01

    Purpose/Objective: Due to the motion of the collimator during dynamic wedge treatments, the conventional method of collecting comprehensive wedge data with a water tank and a scanning ionization chamber is obsolete. It is the objective of this work to demonstrate the use of an electronic portal imaging device (EPID) and software to accomplish this task. Materials and Methods: A Varian Clinac[reg] 2300 C/D, equipped with a PortalVision TM EPID and Dosimetry Research Mode experimental software, was used to produce the radiation field. The Dosimetry Research Mode experimental software allows for a band of 10 of 256 high voltage electrodes to be continuously read and averaged by the 256 electrometer electrodes. The file that is produced contains data relating to the integrated ionization at each of the 256 points, essentially the cross plane beam profile. Software was developed using Microsoft C ++ to reformat the data for import into a Microsoft Excel spreadsheet allowing for easy mathematical manipulation and graphical display. Beam profiles were measured by the EPID with a 100 cm TSD for various field sizes. Each field size was measured open, steel wedged, and dynamically wedged. Scanning ionization chamber measurements performed in a water tank were compared to the open and steel wedged fields. Ionization chamber measurements taken in a water tank were compared with the dynamically wedged measurements. For the EPID measurements the depth was varied using Gammex RMI Solid Water TM placed directly above the EPID sensitive volume. Bolus material was placed between the Solid Water TM and the EPID to avoid an air gap. Results: Comparison of EPID measurements with those from an ion chamber in a water tank showed a discrepancy of ∼5%. Scans were successfully obtained for open, steel wedged and dynamically wedged beams. Software has been developed to allow for easy graphical display of beam profiles. Conclusions: Measurement of dynamic wedge data proves to be easily

  6. Post-operative orbital imaging: a focus on implants and prosthetic devices

    International Nuclear Information System (INIS)

    Adams, Ashok; Mankad, Kshitij; Poitelea, Cornelia; Verity, David H.; Davagnanam, Indran

    2014-01-01

    Accurate interpretation of orbital imaging in the presence of either orbital implants requires a sound knowledge of both the surgical approach used and the imaging characteristics of the implanted devices themselves. In this article, the radiological appearance of the various devices used in ophthalmology, and their relationship to other orbital structures, is reviewed. In addition, the intended anatomical location, function of these devices, and clinical indications for their use are provided. (orig.)

  7. 3D imaging by serial block face scanning electron microscopy for materials science using ultramicrotomy.

    Science.gov (United States)

    Hashimoto, Teruo; Thompson, George E; Zhou, Xiaorong; Withers, Philip J

    2016-04-01

    Mechanical serial block face scanning electron microscopy (SBFSEM) has emerged as a means of obtaining three dimensional (3D) electron images over volumes much larger than possible by focused ion beam (FIB) serial sectioning and at higher spatial resolution than achievable with conventional X-ray computed tomography (CT). Such high resolution 3D electron images can be employed for precisely determining the shape, volume fraction, distribution and connectivity of important microstructural features. While soft (fixed or frozen) biological samples are particularly well suited for nanoscale sectioning using an ultramicrotome, the technique can also produce excellent 3D images at electron microscope resolution in a time and resource-efficient manner for engineering materials. Currently, a lack of appreciation of the capabilities of ultramicrotomy and the operational challenges associated with minimising artefacts for different materials is limiting its wider application to engineering materials. Consequently, this paper outlines the current state of the art for SBFSEM examining in detail how damage is introduced during slicing and highlighting strategies for minimising such damage. A particular focus of the study is the acquisition of 3D images for a variety of metallic and coated systems. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  8. An inverse method for crack characterization from ultrasonic B-Scan images

    International Nuclear Information System (INIS)

    Faur, M.; Roy, O.; Benoist, PH.; Morisseau, PH.

    1996-01-01

    Concern has been expressed about the capabilities of performing non destructive evaluation (NDE) of flaws located near to the outer surface in nuclear pressurized water reactor (PWR) vessels. The ultrasonic examination of PWR is accomplished from the inside with ultrasonic focused transducers working in the pulse echo mode. By recording the echoes as a function of time, the Ascan representation may be obtained. Many ultrasonic flaw detectors used for NDE are based on the simple Ascan concept involving measuring a time interval called 'time of flight'. By combining the Ascan concept synchronized transducer scanning, one can produce Bscan images that are two dimensional descriptions of the flaw interaction with the ultrasonic field. In the following, the flaw is assumed to be an axially oriented crack (the most serious flaw to be found in a pressurized component). In the case of the outer surface cracks (OSC's), analyzing and interpreting ultrasonic Ascan images become difficult because of the various reflections of the ultrasonic beam on the crack and on the outer surface (the so-called corner effect). Methods for automatic interpretation of ultrasonic experimental data are currently under investigation. In this paper, we present an inverse method for determining the geometrical characteristics of OSC's from ultrasonic Bscan images. The direct model used for the inversion procedure predicts synthetic Bscan images of ultrasonic examination of blocks containing planar defects interrogated by focused probes. (authors)

  9. Composition quantification of electron-transparent samples by backscattered electron imaging in scanning electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Müller, E., E-mail: erich.mueller@kit.edu; Gerthsen, D.

    2017-02-15

    The contrast of backscattered electron (BSE) images in scanning electron microscopy (SEM) depends on material parameters which can be exploited for composition quantification if some information on the material system is available. As an example, the In-concentration in thin In{sub x}Ga{sub 1−x}As layers embedded in a GaAs matrix is analyzed in this work. The spatial resolution of the technique is improved by using thin electron-transparent specimens instead of bulk samples. Although the BSEs are detected in a comparably small angular range by an annular semiconductor detector, the image intensity can be evaluated to determine the composition and local thickness of the specimen. The measured intensities are calibrated within one single image to eliminate the influence of the detection and amplification system. Quantification is performed by comparison of experimental and calculated data. Instead of using time-consuming Monte-Carlo simulations, an analytical model is applied for BSE-intensity calculations which considers single electron scattering and electron diffusion. - Highlights: • Sample thickness and composition are quantified by backscattered electron imaging. • A thin sample is used to achieve spatial resolution of few nanometers. • Calculations are carried out with a time-saving electron diffusion model. • Small differences in atomic number and density detected at low electron energies.

  10. Specimen preparation, imaging, and analysis protocols for knife-edge scanning microscopy.

    Science.gov (United States)

    Choe, Yoonsuck; Mayerich, David; Kwon, Jaerock; Miller, Daniel E; Sung, Chul; Chung, Ji Ryang; Huffman, Todd; Keyser, John; Abbott, Louise C

    2011-12-09

    Major advances in high-throughput, high-resolution, 3D microscopy techniques have enabled the acquisition of large volumes of neuroanatomical data at submicrometer resolution. One of the first such instruments producing whole-brain-scale data is the Knife-Edge Scanning Microscope (KESM), developed and hosted in the authors' lab. KESM has been used to section and image whole mouse brains at submicrometer resolution, revealing the intricate details of the neuronal networks (Golgi), vascular networks (India ink), and cell body distribution (Nissl). The use of KESM is not restricted to the mouse nor the brain. We have successfully imaged the octopus brain, mouse lung, and rat brain. We are currently working on whole zebra fish embryos. Data like these can greatly contribute to connectomics research; to microcirculation and hemodynamic research; and to stereology research by providing an exact ground-truth. In this article, we will describe the pipeline, including specimen preparation (fixing, staining, and embedding), KESM configuration and setup, sectioning and imaging with the KESM, image processing, data preparation, and data visualization and analysis. The emphasis will be on specimen preparation and visualization/analysis of obtained KESM data. We expect the detailed protocol presented in this article to help broaden the access to KESM and increase its utilization.

  11. Theoretical and experimental study of image formation in scanning transmission electron microscopy

    International Nuclear Information System (INIS)

    Prunier epouse Mory, Claudie

    1985-01-01

    This thesis contains a theoretical and experimental study of image formation in a dedicated scanning transmission electron microscope (STEM). Using a detailed description of the different optical elements between the field emission source and the specimen, one calculates the shape and size of the primary probe of electrons impinging on the sample. This modelization enables to estimate the spatial resolution in the different imaging or microanalytical modes. The influence of the specimen and the role of the various detectors are taken into account to calculate the point spread function of the instrument in STEM imaging modes. An experimental study of the characteristic properties of phase contrast bright field micrographs and incoherent dark field ones is performed by comparison of digitally recorded images in similar conditions. Spatial resolution, contrast and signal/noise ratio are assessed by correlation methods, Fourier analysis and statistical considerations; one can deduce the optimum focusing conditions. Limits such as the point resolution on quasi-atomic metallic clusters are determined and an analysis of the capabilities of signal mixing concludes this work. Applications are offered in various domains such as the visualisation of small metallic particles, biomolecules and unstained biological sections. (author) [fr

  12. Technique for evaluation of spatial resolution and microcalcifications in digital and scanned images of a standard breast phantom

    International Nuclear Information System (INIS)

    Santana, Priscila do C.; Gomes, Danielle S.; Oliveira, Marcio A.; Oliveira, Paulo Marcio C. de; Meira-Belo, Luiz C.; Nogueira-Tavares, Maria S.

    2011-01-01

    In this work, an automated methodology to evaluate digital and scanned images of a standard phantom (Phantom Mama) was studied. The Phantom Mama was used as an important tool to check the quality of mammographs. The scanned images were digitized using a ScanMaker 9800XL, with resolution of 900 dpi. The aim of this work is to test an automatic methodology for evaluation of spatial resolution and microcalcifications group of phantom mama images acquired with the same parameters in the same equipment. In order to analyze the images we have used the ImageJ software (in Java) which is public domain. We have used the Fast Fourier transform technique to evaluate the spatial resolution and used the ImageJ function Subtract Background and the Light Background plus Sliding Paraboloid on the evaluation of the five groups of microcalcifications on the breast phantom to assess the viability of using automated methods for both types of images. The methodology was adequate for evaluated the microcalcifications group and the spatial resolution in scanned and digital images, but the Phantom Mama doesn't provide sufficient parameters to evaluate the spatial resolution in this <