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Proceedings of the 2019 3rd International conference on advances in Image Processing

作者： Shuai Guo Songyuan Tang Jianjun Zhu Jingfan Fan Danni Ai Hong Song Ping Liang Jian Yang Beijing Engineering Research Center of Mixed Reality and Advanced Display School of Optics and Electronics Beijing Institute of Technology Beijing China School of Computer Science and Technology Beijing Institute of Technology Beijing China Department of Interventional Ultrasound Chinese PLA General Hospital Beijing China

ISBN: (纸本)9781450376754

In percutaneous coronary intervention (PCI), physicians use a guidewire tip to implant stents in vessels with stenosis. Given the small scale and low signal-to-noise ratio of guidewire tips in x-ray fluoroscopy images, physicians experience difficulty in recognizing and locating the tip. The automatic segmentation of the guidewire tip can ease navigation when the physicians implant stents for PCI. In this paper, we propose an end-to-end convolutional neural network-based method for guidewire tip segmentation. The network framework is derived from U-Net, and two specific designs involving reduced dense block and connectivity supervision are embedded in the framework to improve the accuracy and robustness of guidewire tip segmentation. Experiments are performed on clinical data. The proposed method achieves mean sensitivity, F1-score, Jaccard index, Hausdorff distance of 92.95%, 91.35%, 84.14%, and 0.531 mm on testing data, respectively. In addition, the segmentation time is 0.02 s/frame, which can satisfy the requirements for clinical intra-practice.

关键词： Connectivity Guidewire tip segmentation Deep Learning CNN

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Improved U-Net for guidewire tip segmentation in x-ray fluoroscopy images 3

Improved U-Net for guidewire tip segmentation in X-ray fluor...

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3rd International conference on advances in Image Processing, ICAIP 2019

作者： Guo, Shuai Tang, Songyuan Zhu, Jianjun Fan, Jingfan Ai, Danni Song, Hong Liang, Ping Yang, Jian Beijing Engineering Research Center of Mixed Reality and Advanced Display School of Optics and Electronics Beijing Institute of Technology Beijing100081 China School of Computer Science and Technology Beijing Institute of Technology Beijing100081 China Department of Interventional Ultrasound Chinese PLA General Hospital 28 Fuxing Road Beijing100853 China

ISBN: (纸本)9781450376754

关键词： Stents

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The compact x-ray source Thomx 6

The compact X-ray source ThomX

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conference on advances in laboratory-based x-ray sources, optics, and Applications VI

作者： Favier, P. Amoudry, L. Cassou, K. Dupraz, K. Martens, A. Monard, H. Zomer, F. Univ Paris Saclay Univ Paris Sud LAL CNRSIN2P3 Orsay France

ISBN: (纸本)9781510612327;9781510612310

Thomx is a compact Compton based x-ray source under construction at LAL in Orsay (France). The Thomx facility is composed of a 50-70 MeV linac, a transfer line and an 18 meters long storage ring. Compton scattering between 50 MeV, 1 nC electron bunches and 10 mJ laser pulses stacked in a Fabry-Perot cavity results in the production of photons with energies up to 90 keV with a maximum flux of 10(13) photons per second. The Thomx building is close to be finished. The installation of the accelerator will start in 2018, followed by the optical table and the Fabry-Perot cavity.

关键词： x-rays Compton scattering Laser Accelerator

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New twist in the optical schematic of surface slope measuring long trace profiler 7

New twist in the optical schematic of surface slope measurin...

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conference on advances in Metrology for x-ray and EUV optics VII

作者： Nikitin, Sergey M. Gevorkyan, Gevork S. McKinney, Wayne R. Lacey, Ian Takacs, Peter Z. Yashchuk, Valeriy V. Lawrence Berkeley Natl Lab Adv Light Source One Cyclotron Rd Berkeley CA 94720 USA Diablo Valley Coll 321 Golf Club Rd Pleasant Hill CA 94523 USA Brookhaven Natl Lab POB 5000 Upton NY 11973 USA

ISBN: (数字)9781510612280

ISBN: (纸本)9781510612280;9781510612273

The advents of fully coherent free electron lasers and diffraction limited synchrotron storage ring sources of x-rays are catalyzing the development of new, ultra-high accuracy metrology methods. To fully exploit the potential of these sources, metrology needs to be capable of determining the figure of an optical element with sub-nanometer height accuracy. Currently, the two most prevalent slope measuring instruments used for characterization of x-ray optics are the auto-collimator based nanometer optical measuring device (NOM) and the long trace profiler (LTP) using pencil beam interferometry (PBI). These devices have been consistently improved upon by the x-ray optics metrology community, but appear to be approaching their metrological limits. Here, we revise the traditional optical schematic of the LTP. We experimentally show that, for the level of accuracy desired for metrology with state-of-the-art x-ray optics, the Dove prism in the LTP reference channel appears to be one of the major sources of instrumental error. Therefore, we suggest returning back to the original PBI LTP schematics with no Dove prism in the reference channel. In this case, the optimal scanning strategies [Yashchuk, Rev. Sci. Instrum. 80, 115101 (2009)] used to suppress the instrumental drift error have to be used to suppress a possible drift error associated with laser beam pointing instability. We experimentally and by numerical simulation demonstrate the usefulness of the suggested approach for measurements with x-ray optics with both face up and face down orientations.

关键词： x-ray optics optical metrology surface slope profilometry LTP pencil beam interferometry Dove prism error reduction ZEMAx simulation

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Multilayer based x-ray optics at the ESRF

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AIP conference Proceedings 2019年第1期2054卷

作者： Christian Morawe ESRF F-38043 Grenoble France

Multilayer (ML) based x-ray optics have gained considerable interest at 3rd generation synchrotron light sources. Over the last 20 years, more than 200 devices have been fabricated at the ESRF ML laboratory and deployed on ESRF beamlines, mainly in two configurations: as Kirkpatrick-Baez (KB) focusing devices and as double-bounce high-flux monochromators. The KB mirrors are either bent or polished to their elliptical figure. The ML coatings require steep meridional thickness gradients to account for the variable angle of reflection along the beam footprint. The increased incident angles as compared to total reflection mirrors provide larger numerical apertures and therefore smaller diffraction limited focal spots. At present, ESRF KB optics reach spot sizes down to about 12 nm and are being operated up to photon energies of 65 keV. Double ML monochromators (DMM) are an interesting alternative to double crystal monochromators (DCM) whenever high flux rather than high spectral resolution is required. On many new ESRF beamlines, monochromators with bandwidths between 0.1% and 0.5% are part of the optics layout. The production of efficient DMMs with such narrow bandwidths is challenging since it implies a large number of bi-layers and low d-spacings. Possible thickness variations in depth and along the beam footprint must remain within these tolerances in order not to spoil their performance. Recently installed DMMs achieve a spectral resolution better than 0.4% and a total transmission above 50%. This paper will recall some fundamental design aspects for ML x-ray optics and show examples of applications on ESRF beamlines. It will address present limitations and discuss possible approaches to improve the ML performance.

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Atomic Orientation Detection using Nonlinear optics and its Application as an Environmental Sensor 3

Atomic Orientation Detection using Nonlinear Optics and its ...

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3rd International Seminar on Sciences - Sciences on Precision and Sustainable Agriculture (ISS)

作者： Tawakal, M. R. Alatas, H. Hardhienata, H. Bogor Agr Univ Dept Phys Theoret Phys Div Jl MerantiGedung Wing SKampus IPB Darmaga Bogor 16680 Jawa Barat Indonesia

Recent advances in theoretical nonlinear optics have enhanced our understanding regarding the origin of the higher harmonic generation in particular interpreting the higher harmonic intensity data from nonlinear spectroscopy. In this work we show that the atomic bond orientation at the surface as well as the bulk of an inversion symmetric material e.g. Silicon (111) facet can be determined from nonlinear spectroscopy alone without the need to apply the conventional x-ray diffraction method. Our simulation shows that nonlinear spectroscopy data interpreted using bond models can reliably determine atomic orientation almost in a direct way because the model is based on a very simple assumption that the radiations are created from charges along the atomic bonds. In addition we present a brief description of possible application to use nonlinear spectroscopy as an environmental sensor.

关键词： bond model second harmonic generation third harmonic generation atomic orientation

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Methods for reducing singly reflected rays on the Wolter-I focusing mirrors of the FOxSI rocket experiment 8

Methods for reducing singly reflected rays on the Wolter-I f...

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conference on optics for EUV, x-ray, and Gamma-ray Astronomy VIII

作者： Buitrago-Casas, Juan Camilo Elsner, Ronald Glesener, Lindsay Christe, Steven Ramsey, Brian Courtade, Sasha Ishikawa, Shin-nosuke Narukage, Noriyuki Turin, Paul Vievering, Juliana Athiray, P. S. Musset, Sophie Krucker, Sam Univ Calif Berkeley Space Sci Lab 7 Gauss Way Berkeley CA 94720 USA NASA Marshall Space Flight Ctr Space Sci Off ZP12 Huntsville AL 35812 USA Univ Minnesota Sch Phys & Astron 116 Church St SE Minneapolis MN 55455 USA NASA Goddard Space Flight Ctr 8800 Greenbelt Rd Greenbelt MD 20771 USA Japan Aerosp Explorat Agcy Inst Space & Astronaut Sci Chuo Ku 3-1-1 Yoshinodai Sagamihara Kanagawa 2525210 Japan Natl Astron Observ Japan 2-21-1 Osawa Mitaka Tokyo 1818588 Japan Univ Appl Sci Northwestern Switzerland Windisch Switzerland

ISBN: (数字)9781510612563

ISBN: (纸本)9781510612563;9781510612556

In high energy solar astrophysics, imaging hard x-rays by direct focusing offers higher dynamic range and greater sensitivity compared to past techniques that used indirect imaging. The Focusing optics x-ray Solar Imager (FOxSI) is a sounding rocket payload that uses seven sets of nested Wolter -I figured mirrors together with seven high -sensitivity semiconductor detectors to observe the Sun in hard x-rays through direct focusing. The FOxSI rocket has successfully flown twice and is funded to fly a third time in summer 2018. The Wolter -I geometry consists of two consecutive mirrors, one paraboloid and one hyperboloid, that reflect photons at grazing angles. Correctly focused x-rays reflect once per mirror segment. For extended sources, like the Sun, off -axis photons at certain incident angles can reflect on only one mirror and still reach the focal plane, generating a background pattern of singly reflected rays (i.e., ghost rays) that can limit the sensitivity of the observation to faint, focused sources. Understanding and mitigating the impact of the singly reflected rays on the FOxSI optical modules will maximize the instruments' sensitivity to background -limited sources. We present an analysis of the FOxSI singly reflected rays based on ray -tracing simulations and laboratory measurements, as well as the effectiveness of different physical strategies to reduce them.

关键词： FOxSI x-ray telescope solar Wolter-I optics

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laboratory-based x-ray phase-contrast tomography enables 3D virtual histology 5

Laboratory-based x-ray phase-contrast tomography enables 3D ...

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conference on advances in laboratory-based x-ray sources, optics, and Applications V

作者： Toepperwien, Mareike Krenkel, Martin Quade, Felix Salditt, Tim Inst Xray Phys Friedrich Hund Platz 1 Gottingen Germany Johann Friedrich Blumenbach Inst Zool & Anthropol Dept Dev Biol Justus von Liebig Weg 11 Gottingen Germany

ISBN: (数字)9781510603202

ISBN: (纸本)9781510603196;9781510603202

Due to the large penetration depth and small wavelength hard x-rays offer a unique potential for 3D biomedical and biological imaging, combining capabilities of high resolution and large sample volume. However, in classical absorption-based computed tomography, soft tissue only shows a weak contrast, limiting the actual resolution. With the advent of phase-contrast methods, the much stronger phase shift induced by the sample can now be exploited. For high resolution, free space propagation behind the sample is particularly well suited to make the phase shift visible. Contrast formation is based on the self-interference of the transmitted beam, resulting in object-induced intensity modulations in the detector plane. As this method requires a sufficiently high degree of spatial coherence, it was since long perceived as a synchrotron-based imaging technique. In this contribution we show that by combination of high brightness liquid-metal jet microfocus sources and suitable sample preparation techniques, as well as optimized geometry, detection and phase retrieval, excellent three-dimensional image quality can be obtained, revealing the anatomy of a cobweb spider in high detail. This opens up new opportunities for 3D virtual histology of small organisms. Importantly, the image quality is finally augmented to a level accessible to automatic 3D segmentation.

关键词： laboratory-based x-ray phase contrast propagation-based imaging tomography 3D virtual histology

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New operational mode of the pencil beam interferometry based LTP 6

New operational mode of the pencil beam interferometry based...

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conference on advances in Metrology for x-ray and EUV optics VI

作者： Centers, Gary Smith, Brian V. Yashchuk, Valeriy V. Lawrence Berkeley Natl Lab Adv Light Source One Cyclotron Rd Berkeley CA 94720 USA

ISBN: (数字)9781510603165

ISBN: (纸本)9781510603158;9781510603165

The advent of fully coherent free electron laser and diffraction limited synchrotron storage ring sources of x-rays is catalyzing the development of new ultra-high accuracy metrology methods. To fully exploit the potential of these sources, metrology needs to be capable of determining the figure of an optical element with sub-nanometer height accuracy. Currently, the two most prevalent slope measuring instruments used for characterization of x-ray optics are the auto-collimator based nanometer optical measuring device (NOM) and the long trace profiler (LTP) using pencil beam interferometry. These devices have been consistently improved upon by the x-ray optics metrology community, but appear to be approaching their metrological limits. Here, we consider a novel operational mode for the LTP. The fundamental measuring principle of the LTP is reviewed, and a suggested mode of operation is analytically derived. This mode of operation leads to significant suppression of the instrumental systematic errors. Via cross-comparison measurement with the LTP in old and new modes, the performance of the profiler in the new mode is investigated. We also discuss potential areas of further development, including the possibility for local curvature measurement.

关键词： x-ray optics optical metrology surface slope profilometry LTP pencil beam interferometry error reduction calibration

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A Case for ZnO Nanowire Field Emitter Arrays in Advanced x-ray Source Applications 5

A Case for ZnO Nanowire Field Emitter Arrays in Advanced X-r...

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conference on advances in laboratory-based x-ray sources, optics, and Applications V

作者： Robinson, Vance S. Bergkvist, Magnus Chen, Daokun Chen, Jun Huang, Mengbing SUNY Polytech Inst Coll Nanoscale Sci & Engn 257 Fuller Rd Albany NY 12203 USA Sun Yat Sen Univ Guangdong Prov Key Lab Display Mat & Technol State Key Lab Optoelect Mat & Technol Guangzhou 510275 Guangdong Peoples R China Sun Yat Sen Univ Sch Elect & Informat Technol Guangzhou 510275 Guangdong Peoples R China

ISBN: (数字)9781510603202

ISBN: (纸本)9781510603196;9781510603202

Reviewing current efforts in x-ray source miniaturization reveals a broad spectrum of applications: Portable and/or remote nondestructive evaluation, high throughput protein crystallography, invasive radiotherapy, monitoring fluid flow and particulate generation in situ, and portable radiography devices for battle-front or large scale disaster triage scenarios. For the most part, all of these applications are being addressed with a top-down approach aimed at improving portability, weight and size. That is, the existing system or a critical sub-component is shrunk in some manner in order to miniaturize the overall package. In parallel to top-down x-ray source miniaturization, more recent efforts leverage field emission and semiconductor device fabrication techniques to achieve small scale x-ray sources via a bottom-up approach where phenomena effective at a micro/nanoscale are coordinated for macro-scale effect. The bottom-up approach holds potential to address all the applications previously mentioned but its entitlement extends into new applications with much more ground-breaking potential. One such bottom-up application is the distributed x-ray source platform. In the medical space, using an array of microscale x-ray sources instead of a single source promises significant reductions in patient dose as well as smaller feature detectability and fewer image artifacts. Cold cathode field emitters are ideal for this application because they can be gated electrostatically or via photonic excitation, they do not generate excessive heat like other common electron emitters, they have higher brightness and they are relatively compact. This document describes how ZnO nanowire field emitter arrays are well suited for distributed x-ray source applications because they hold promise in each of the following critical areas: emission stability, simple scalable fabrication, performance, radiation resistance and photonic coupling.

关键词： ZnO Nanowires field emission cold cathode distributed source

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