Third International Workshop on Imaging Techniques with Synchrotron Radiation

The Fourth International Workshop on Imaging Techniques in Synchrotron Radiation was held September 24–27, 2011, in the famous wine-growing town of Bordeaux, France. Previous meetings were held in China: Hefei (2008), Sanya (2009), and Suzhou (2010). Delegates were primarily from Europe, Asia, and the U.S., with 55 participants representing 15 countries and 15 synchrotron facilities. The workshop was organized by Cyril Petibois (Univ. Bordeaux, France), Augusto Marcelli (INFN-LNF, Italy), and Ziyu Wu (NSRL and BSRF, P.R. China). The program was based on a combination of oral sessions and thematic roundtables for discussion. Topics covered applications of various imaging techniques including image processing, imaging in environmental and materials sciences, phase contrast imaging, nanoscopy, vibrational spectroscopy and molecular imaging, imaging in biosciences, and imaging detectors.

Phase tomography based on hard X-ray double-grating interferometry (XDGI) is a well-established imaging technique for the three-dimensional visualization of soft tissues, providing tomograms with superior contrast. The experimental setup contains a beam-splitter grating and an analyzer grating. Both gratings have to be placed and oriented with high precision for an optimized functioning of the interferometer. The analyzer grating can be omitted, if the detection unit allows a direct detection of the interference pattern. Such a setup is termed hard X-ray single-grating interferometer (XSGI). XSGI profits from easier handling, as only one grating needs to be aligned, and from the related cost reduction. But, more importantly than that, for the XSGI the spatial resolution is not limited by the period of the analyzer grating, and for equal photon flux, the number of detected photons is increased by a factor of about two. In the present thesis, a peripheral human nerve was embedded in paraffin. In order to compare the performance of XSGI and XDGI for medically relevant, low-absorbing specimens, for both modalities the specimen was measured at the facility Deutsches Elektronen-Synchrotron (DESY), using synchrotron radiation. Subsequently, the acquired tomograms were superimposed using rigid registration, i.e. one dataset was translated and rotated to best fit the other one. Both techniques allow resolving anatomical features of the nerve investigated, including epineurium, perineurium, and endoneurium. Whereas the XDGI data exhibit a better contrast-to-noise ratio, the XSGI tomogram shows an improved spatial resolution by a factor close to two. Thus, it can be concluded that XSGI is the preferred approach for the visualization of paraffin-embedded soft tissues.

A program devoted to perform the first in-vivo monochromatic breast computed tomography (BCT) is ongoing at the Elettra Synchrotron Facility. Since the synchrotron radiation provides high energy resolution and spatial coherence, phase-contrast (PhC) imaging techniques can be used. The latest high resolution BCT acquisitions of breast specimens, obtained with the propagation-based PhC approach, are herein presented as part of a wider framework, devoted to the optimization of acquisition and reconstruction parameters towards the clinical exam. Images are acquired with a state-of-the-art dead-time-free single-photon-counting CdTe detector with a 60 µm pixel size. The samples are imaged at 32 and 38 keV in continuous rotating mode, delivering 5-20 mGy of mean glandular dose (MGD). Contrast-to-noise ratio (CNR) and spatial resolution performances are evaluated for both absorption and phase-retrieved images considering tumor/adipose tissue interfaces. We discuss two different phase-retrieval approaches, showing that a remarkable CNR increase (from 0.5 to 3.6) can be obtained without a significant loss in spatial resolution. It is shown that, even if the non-phase-retrieved image has a poorer CNR, it is useful for evaluating the spiculation of a microcalcification: in this context, absorption and phase-retrieved images have to be regarded as complementary information. Furthermore, the first full volume acquisition of a mastectomy, with a 9 cm diameter and 3 cm height, is reported. This investigation on surgical specimens indicates that monochromatic BCT with synchrotron radiation in terms of CNR, spatial resolution, scan duration and scan volume is feasible.

A program devoted to performing the first in vivo synchrotron radiation (SR) breast computed tomography (BCT) is ongoing at the Elettra facility. Using the high spatial coherence of SR, phase-contrast (PhC) imaging techniques can be used. The latest high-resolution BCT acquisitions of breast specimens, obtained with the propagation-based PhC approach, are herein presented as part of the SYRMA-3D collaboration effort toward the clinical exam. Images are acquired with a dead-time-free single-photon-counting CdTe detector. The samples are imaged at 32 and 38keV in a continuous rotating mode, delivering 5 to 20mGy of mean glandular dose. Contrast-to-noise ratio (CNR) and spatial resolution performances are evaluated for both PhC and phase-retrieved images, showing that by applying the phase-retrieval algorithm a five-time CNR increase can be obtained with a minor loss in spatial resolution across soft tissue interfaces. It is shown that, despite having a poorer CNR, PhC images can provide a sharper visualization of microcalcifications, thus being complementary to phase-retrieved images. Furthermore, the first full-volume scan of a mastectomy sample ( ) is reported. This investigation into surgical specimens indicates that SR BCT in terms of CNR, spatial resolution, scan duration, and scan volume is feasible.

The papers in this special issue focus on machine learning for use in medical image processing applications. The use of machine learning in this area has become indispensable in diagnosis and treatment of many diseases. With advances in new imaging techniques, the need to take full advantage of abundant images draws more and more attention. Machine learning, including deep learning particularly, provides us a new paradigm to learn and to utilize the overwhelming volume of big imaging data smartly. Nowadays, machine learning in medical imaging has become one of the most promising and growing fields of research. The main aim of this special issue is to help advance the scientific research within the broad field of machine learning in medical imaging. The special issue was planned in conjunction with the International Workshop on Machine Learning in Medical Imaging (MLMI) 2017.

The purpose of this paper is to review the studies performed to evaluate the influence of perinatal environment on neonatal heart, detected by electrocardiography, echocardiography, and other imaging techniques. Prenatal conditions (such as intrauterine growth retardation and prematurity at birth) and some post-natal events (such as perinatal asphyxia and corticosteroids administration), may have early and late detrimental effects on the heart may predispose to a number of future cardiovascular adverse events. For example, subjects born preterm may be at potentially higher risk of developing malignant ventricular arrhythmias as well. Moreover, in individuals born with an extremely low birthweight atrial septal aneurysms are present in about one third of the subjects in the study. Thus, a long-life follow up is suggested in these subjects. Proceedings of the 11th International Workshop on Neonatology and Satellite Meetings · Cagliari (Italy) · October 26th-31st, 2015 · From the womb to the adult Guest Editors: Vassilios Fanos (Cagliari, Italy), Michele Mussap (Genoa, Italy), Antonio Del Vecchio (Bari, Italy), Bo Sun (Shanghai, China), Dorret I. Boomsma (Amsterdam, the Netherlands), Gavino Faa (Cagliari, Italy), Antonio Giordano (Philadelphia, USA)

Synchrotron light sources are key instruments of modern science, providing unique opportunities for groundbreaking studies in diverse scientific disciplines and driving innovation in numerous scientific and technological fields. Fourth-generation light sources provide unprecedented capabilities in imaging, spectroscopy and diffraction techniques. Ultimate brightness is the key to advancing to a smaller scale, faster response, and higher data measurement and processing rate. The brightness is primarily determined by the electron beam emittance and energy spread at operational intensity. A common feature of fourth-generation synchrotrons is the short length of the electron bunches combined with a very small transverse beam size. Consequently, the high particle density leads to strong collective effects that significantly increase the emittance and limit the achievable brightness at operational beam intensity. In this article, we summarize our studies of the emittance and brightness scaled with the beam energy and intensity, taking into account the effects of intrabeam scattering, beam-impedance interaction and bunch lengthening provided by higher-harmonic RF systems to identify optimal combinations of machine and beam parameters.

Infrared microscopy in the study of cellular biochemistry

High resolution section topographs are made with synchrotron radiation using exposure times that are 1/1000 or less of those necessary with conventional x-ray sources. The imaging technique is employed to study oxygenrelated defects and their spatial distribution in a large number of annealed p-type (100) Czochralski silicon wafers. A two-step annealing in nitrogen consisted of a nucleation cycle at 800 °C and at 825 °C for 20 h followed by a denuding cycle at 1100 °C for 6 h. Denuded zones measuring from zero to 100 μm are seen in the synchrotron section topographs made after oxidation of the wafers at 1100 °C for 2 h. The denuded zone formation is found to depend strongly on the part of the crystal from which the wafer is cut. The wafers have the same interstitial oxygen concentration but different carbon concentrations. Large spatial variations up to 100 μm of the denuded zone width are observed in some wafers. Synchrotron section topographs of the wafers in which CMOS devices were fabricated showed a denuded zone only if the wafers were thremally annealed before the IC process.

This special issue of Journal of Physics: Condensed Matter contains a selection of invited and contributed papers presented at Symposium J: Synchrotron Radiation for Advanced Materials Analysis and Processing, part of the International Conference on Materials for Advanced Technologies 2003 (ICMAT 2003) and the International Union of Materials Research Societies International Conference in Asia 2003 (IUMRS-ICA 2003) which was held on 7–12 December 2003 in Singapore. ICMAT 2003 attracted more than 1500 participants and was graced by the presence of Nobel laureates Klaus von Klitzing and Sir Harry W Kroto who gave plenary and public lectures.One of 16 symposia, Symposium J brought together 54 researchers with various backgrounds from Asia, Australia, Europe and North America. In a relaxed and comfortable atmosphere, participants were presented 1 keynote and 17 invited papers, and 15 contributed oral talks as well as 21 posters covering diverse cutting-edge work made possible by exploiting synchrotron radiation. The relaxed atmosphere encouraged lively discussions.This special issue contains a variety of topics which are briefly described here with reference to the keynote and invited papers. H-D Nuhn paints a broad picture of the successful development of third-generation storage-ring-based synchrotron light sources and the ongoing projects aimed at building x-ray free electron lasers. Then, using photoemission, L I Johansson discusses the nature of the SiO2/SiC interface that is attracting keen interest for its significance for semiconductor manufacturing. Presenting photoelectron diffraction, E G Michel takes the same material and shows the solution of the atomic structure in the case of the (3×2) surface reconstruction of cubic SiC. S Lizzit describes the production of high-quality thin films of the inter-metallic superconductor MgB2 by molecular beam epitaxy and their characterization by photoemission, absorption spectroscopy, and low-energy electron diffraction. Using data obtained by simultaneous wide- and small-angle scattering as well as x-ray absorption spectroscopy, N Greaves gives a detailed explanation of how zeolites collapse when pressurized or heated. Moving on to polymers, H J Kim investigates surface capillary waves on polymer films via x-ray photon correlation spectroscopy. The growth of biological cells on polymer scaffolds is studied by P Thurner using micro-computed tomography with synchrotron radiation. S Cabrini gives an overview of the use of x-ray lithography to fabricate micro- and nano-devices for various applications. Finally, N Umesaki reports examples of applications of synchrotron radiation to characterize important industrial samples and processes.It is a special pleasure to acknowledge the strong and comprehensive help of co-chairs O Wilhelmi and P Yang and of Ms K L Chong. Many thanks as well to the members of the Scientific Committee who gave their advice, to the members of the Local Organizing Committee, the Session Chairmen, and the Exhibitors and Sponsors. Last, but not least, the effort of authors and referees as well as of the publisher to produce this special issue is greatly appreciated. Herbert O MoserSingapore Synchrotron Light Source, National University of Singapore e-mail: moser@nus.edu.sgChair: Symposium J, ICMAT 2003Scientific CommitteeH Dosch (Chair), MPI for Metal Research, GermanyS Baik, Pohang Light Source, KoreaG L Carr, NSLS, USAR J Cernik, Daresbury Laboratory, UKG N Greaves, University of Wales, Aberystwyth, UKS Kikuta, JASRI, JapanM Kovalchuk, RAS, RussiaZ H Mai, Beijing Synchrotron Radiation Facility, ChinaG Margaritondo, EPFL, SwitzerlandN Mårtensson, MAX Lab and University of Uppsala, SwedenT Matsushita, Photon Factory, JapanH O Moser, SSLS, SingaporeH Ohno, SPring-8, JapanH A Padmore, ALS, USAP Soukiassian, CEA and Université Paris-Sud, FranceA Stevenson, CSIRO, AustraliaW G Stirling, ESRF, FranceM Taniguchi, HISOR, JapanLocal Organizing CommitteeH O Moser (Chair), SSLS/NUSK L Chong, SSLS/NUSW S Sim, NUS/ChemistryA T S Wee, NUS/PhysicsO Wilhelmi, SSLS/NUSP Yang, SSLS/NUSExhibitorsFEIHecus M BraunM-O-TNanofilm Technologies InternationalRaithSponserPRIMA Research and Technologies

It is with great pleasure that we present this special issue focused on topological structures in ferroic materials. It is composed of invited contributions from the International Workshop on Topological Structures in Ferroic Materials held at the University of South Wales, Sydney, Australia from 19-21 st May 2015. The aim of the workshop was to capture current research interests regarding interfaces, domains, domain walls, vortices and skyrmions in ferroics as an emerging and highly active fi eld in solid state physics and materials science. Signifi cant emphasis was placed on understanding the fundamental commonalities that bridge topological defects across various types of ferroic materials, and therefore lessons learned on how new and groundbreaking functionalities afforded by the aforementioned concepts could be translated into emerging technologies.

Simple and useful approximations, valid at infrared wavelengths, to the equations for synchrotron radiation are presented and used to quantify the brightness and power advantage of current synchrotron radiation light sources over conventional infrared broadband laboratory sources. The Daresbury Synchrotron Radiation Source (SRS) and the Brookhaven National Synchrotron Light Source (vacuum ultraviolet) [NSLS(VUV)] storage rings are used as examples in the calculation of the properties of infrared synchrotron radiation. The pulsed nature of the emission is also discussed, and potential areas of application for the brightness, power, and time structure advantages are presented. The use of infrared free electron lasers and undulators on the next generation of storage ring light sources is briefly considered.

The objective of this study was to develop and validate a technique for both 3D imaging and quantification of the vascular network of bone tissue in the rat. Five month-old male Wistar rats were divided into tail-suspension (21 days) and control groups. Sixty percent barium sulfate solution was infused into the vena cava. The tibiae were evaluated in 2D and 3D before and after decalcification, using conventional microcomputerized tomography (muCT) at 10 and 5 mum resolution and synchrotron radiation (SR) muCT. The perfusion technique and tomography exhibited excellent bone vasculature imaging. Significant positive correlations were observed between 2D histomorphometric and 3D muCT vascular parameters (P < 0.05). 3DmuCT discriminated significant changes of vessel structures in unloading condition: vessel number decreased by 25%, (P < 0.005), vessel separation increased by 27%, P < 0.01. SRmuCT could image sinusoid clusters in bone. muCT is an accurate and reproducible technique for 3D quantitative evaluation of long bone vascularisation in the rat.

Several synchrotron light sources are currently designing a lattice upgrade to reach low (sub-nm) emittances, which inevitably entails a significant beam lifetime reduction. In view of the ALBA lattice upgrade, it was decided to evaluate different methods using the current ALBA storage ring to reach large betatron coupling as a way to increase the lifetime. In a first attempt, coupling was introduced by means of static skew quadrupolar magnets and by tuning the working point onto the resonance <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:msub><a:mi>Q</a:mi><a:mi>x</a:mi></a:msub><a:mo>=</a:mo><a:msub><a:mi>Q</a:mi><a:mi>y</a:mi></a:msub></a:math>, but in a realistic scenario, some kind of tune feedback is required to counteract the unavoidable tune drifts and fluctuations that would drive the system out of resonance. Furthermore, the condition <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:msub><c:mi>Q</c:mi><c:mi>x</c:mi></c:msub><c:mo>=</c:mo><c:msub><c:mi>Q</c:mi><c:mi>y</c:mi></c:msub></c:math> constrains the linear optics resulting in an important lack of flexibility. Therefore a second method is proposed, based on the excitation of the coupling resonance with an ac skew quadrupole driven at the frequency <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" display="inline"><e:msub><e:mi>f</e:mi><e:mi>rev</e:mi></e:msub><e:mo stretchy="false">(</e:mo><e:msub><e:mi>Q</e:mi><e:mi>x</e:mi></e:msub><e:mo>−</e:mo><e:msub><e:mi>Q</e:mi><e:mi>y</e:mi></e:msub><e:mo stretchy="false">)</e:mo></e:math>. In this case, we used the existing four-electrode tune excitation stripline recabled as a skew quadrupole. A fast tune tracking system was implemented to drive the skew quadrupole exactly on the resonance despite the tune fluctuations. This work goes over the collected results and experiences, aiming to put into light pitfalls and limits of the application of coupling to achieve round beams in a synchrotron light source.

Formal criteria for assessment of treatment response for patients with Waldenstrom’s macroglobulinaemia (WM) were first proposed by a consensus panel during the Second International Workshop on WM in 2003 (Weber D, Treon SP, Emmanouilides C, Branagan AR, Byrd JC, Blade J, Kimby E. Uniform response criteria in Waldenstrom’s macroglobulinaemia: consensus panel recommendations from the Second International Workshop on Waldenstrom’s Macroglobulinaemia. Semin Oncol 2003;30:127–131). New biological knowledge and new treatment paradigms have made updates necessary, both for clinicians and authorities, especially for evaluation, approval and remuneration of new drugs. The most updated consensus panel response definitions include evaluation of the monoclonal immunoglobulin M in serum, the tumour burden in bone marrow and in extramedullary sites and symptoms of disease. The value of quantitative assessment of the tumour in bone marrow, imaging techniques for extramedullary/nodal disease and assessment of haematological response is still under discussion.