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https://www.readbyqxmd.com/read/28340394/assessment-of-engineered-surfaces-roughness-by-high-resolution-3d-sem-photogrammetry
#1
L C Gontard, J D López-Castro, L González-Rovira, J M Vázquez-Martínez, F M Varela-Feria, M Marcos, J J Calvino
We describe a methodology to obtain three-dimensional models of engineered surfaces using scanning electron microscopy and multi-view photogrammetry (3DSEM). For the reconstruction of the 3D models of the surfaces we used freeware available in the cloud. The method was applied to study the surface roughness of metallic samples patterned with parallel grooves by means of laser. The results are compared with measurements obtained using stylus profilometry (PR) and SEM stereo-photogrammetry (SP). The application of 3DSEM is more time demanding than PR or SP, but it provides a more accurate representation of the surfaces...
March 7, 2017: Ultramicroscopy
https://www.readbyqxmd.com/read/28339918/can-clinically-relevant-dose-errors-in-patient-anatomy-be-detected-by-gamma-passing-rate-or-modulation-complexity-score-in-volumetric-modulated-arc-therapy-for-intracranial-tumors
#2
Shingo Ohira, Yoshihiro Ueda, Masaru Isono, Akira Masaoka, Misaki Hashimoto, Masayoshi Miyazaki, Masaaki Takashina, Masahiko Koizumi, Teruki Teshima
We investigated whether methods conventionally used to evaluate patient-specific QA in volumetric-modulated arc therapy (VMAT) for intracranial tumors detect clinically relevant dosimetric errors. VMAT plans with coplanar arcs were designed for 37 intracranial tumors. Dosimetric accuracy was validated by using a 3D array detector. Dose deviations between the measured and planned doses were evaluated by gamma analysis. In addition, modulation complexity score for VMAT (MCSv) for each plan was calculated. Three-dimensional dose distributions in patient anatomy were reconstructed using 3DVH software, and clinical deviations in dosimetric parameters between the 3DVH doses and planned doses were calculated...
March 3, 2017: Journal of Radiation Research
https://www.readbyqxmd.com/read/28335486/implicit-regularization-for-reconstructing-3d-building-rooftop-models-using-airborne-lidar-data
#3
Jaewook Jung, Yoonseok Jwa, Gunho Sohn
With rapid urbanization, highly accurate and semantically rich virtualization of building assets in 3D become more critical for supporting various applications, including urban planning, emergency response and location-based services. Many research efforts have been conducted to automatically reconstruct building models at city-scale from remotely sensed data. However, developing a fully-automated photogrammetric computer vision system enabling the massive generation of highly accurate building models still remains a challenging task...
March 19, 2017: Sensors
https://www.readbyqxmd.com/read/28334658/extraction-of-the-3d-local-orientation-of-myocytes-in-human-cardiac-tissue-using-x-ray-phase-contrast-micro-tomography-and-multi-scale-analysis
#4
François Varray, Iulia Mirea, Max Langer, Françoise Peyrin, Laurent Fanton, Isabelle E Magnin
This paper presents a methodology to access the 3D local myocyte arrangements in fresh human post-mortem heart samples. We investigated the cardiac micro-structure at a high and isotropic resolution of 3.5 µm in three dimensions using X-ray phase micro-tomography at the European Synchrotron Radiation Facility. We then processed the reconstructed volumes to extract the 3D local orientation of the myocytes using a multi-scale approach with no segmentation. We created a simplified 3D model of tissue sample made of simulated myocytes with known size and orientations, to evaluate our orientation extraction method...
February 20, 2017: Medical Image Analysis
https://www.readbyqxmd.com/read/28333621/reconstructing-evolving-tree-structures-in-time-lapse-sequences-by-enforcing-time-consistency
#5
Przemyslaw Glowacki, Miguel Amavel Pinheiro, Agata Mosinska, Engin Turetken, Daniel Lebrecht, Anthony Holtmaat, Raphael Sznitman, Jan Kybic, Pascal Fua
We propose a novel approach to reconstructing curvilinear tree structures evolving over time, such as road networks in 2D aerial images or neural structures in 3D microscopy stacks acquired in vivo. To enforce temporal consistency, we simultaneously process all images in a sequence, as opposed to reconstructing structures of interest in each image independently. We formulate the problem as a Quadratic Mixed Integer Program and demonstrate the additional robustness that comes from using all available visual clues at once, instead of working frame by frame...
March 10, 2017: IEEE Transactions on Pattern Analysis and Machine Intelligence
https://www.readbyqxmd.com/read/28333040/rigid-motion-correction-of-dual-opposed-planar-projections-in-single-photon-imaging
#6
Georgios I Angelis, William Ryder, John Gillam, Frederic Boisson, Andre Kyme, Roger Fulton, Steven Meikle, Peter Kench
Awake and/or freely moving small animal single photon emission imaging allows the continuous study of molecules exhibiting slow kinetics without the need to restrain or anaesthetise the animals. Estimating motion free projections in freely moving small animal planar imaging can be considered as a limited angle tomography problem, except that we wish to estimate the 2D planar projections rather than the 3D volume, where the angular sampling in all three axes depends on the rotational motion of the animal. In this study, we hypothesise that the motion corrected planar projections estimated by reconstructing an estimate of the 3D volume using an iterative motion compensating reconstruction algorithm and integrating it along the projection path, will closely match the true, motion-less, planar distribution regardless of the object motion...
March 23, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28332211/a-multi-channel-block-matching-denoising-algorithm-for-spectral-photon-counting-ct-images
#7
Adam P Harrison, Ziyue Xu, David A Bluemke, Amir Pourmorteza, Daniel J Mollura
PURPOSE: We present a denoising algorithm designed for a whole-body prototype photon-counting computed tomography (PCCT) scanner with up to 4 energy thresholds and associated energy-binned images. METHODS: Spectral PCCT images can exhibit low signal to noise ratios (SNRs) due to the limited photon counts in each simultaneously-acquired energy bin. To help address this, our denoising method exploits the correlation and exact alignment between energy bins, adapting the highly-effective block-matching 3D (BM3D) denoising algorithm for PCCT...
March 23, 2017: Medical Physics
https://www.readbyqxmd.com/read/28332026/interpolating-and-extrapolating-with-hmsist-%C3%A2-seeking-a-tmax-for-optimal-sensitivity-resolution-and-frequency-accuracy
#8
Sven G Hyberts, Scott A Robson, Gerhard Wagner
Non-Uniform Sampling has the potential to exploit the optimal resolution of high-field NMR instruments. This is not possible in 3D and 4D NMR experiments when using traditional uniform sampling due to the long overall measurement time. Nominally, uniformly sampled time domain data acquired to a maximum evolution time tmax can be extended to high resolution via a virtual maximum evolution time t*max while extrapolating with linear prediction or iterative soft thresholding (IST). At the high resolution obtainable with extrapolation of US data, however, the accuracy of peak positions is compromised as observed when comparing inter- and intra-residue peaks in a 3D HNCA experiment...
March 22, 2017: Journal of Biomolecular NMR
https://www.readbyqxmd.com/read/28331587/a-simple-fast-and-repeatable-survey-method-for-underwater-visual-3d-benthic-mapping-and-monitoring
#9
Oscar Pizarro, Ariell Friedman, Mitch Bryson, Stefan B Williams, Joshua Madin
Visual 3D reconstruction techniques provide rich ecological and habitat structural information from underwater imagery. However, an unaided swimmer or diver struggles to navigate precisely over larger extents with consistent image overlap needed for visual reconstruction. While underwater robots have demonstrated systematic coverage of areas much larger than the footprint of a single image, access to suitable robotic systems is limited and requires specialized operators. Furthermore, robots are poor at navigating hydrodynamic habitats such as shallow coral reefs...
March 2017: Ecology and Evolution
https://www.readbyqxmd.com/read/28331084/structural-insights-into-emerging-pediatric-pathogens-human-bocaparvoviruses
#10
Mario Mietzsch, Shweta Kailasan, Jamie Garrison, Maria Ilyas, Paul Chipman, Kalle Kantola, Mandy E Janssen, John Spear, Duncan Sousa, Robert McKenna, Kevin Brown, Maria Söderlund-Venermo, Timothy Baker, Mavis Agbandje-McKenna
Bocaparvoviruses are emerging pathogens of the Parvoviridae family. Human bocaviruses 1 (HBoV1) causes severe respiratory infections and HBoV2-4 gastrointestinal infections in young children. Recent reports of life threatening cases, lack of direct treatment or vaccination, and a limited understanding of their disease mechanisms demand the need to study these pathogens on a molecular and structural level for the development of therapeutics. Towards this end, the capsid structures of HBoV1, HBoV3, and HBoV4 were determined to 2...
March 22, 2017: Journal of Virology
https://www.readbyqxmd.com/read/28330571/use-of-3d-orbital-reconstruction-in-the-assessment-of-orbital-sexual-dimorphism-and-its-pathological-consequences
#11
N Graillon, C Boulze, P Adalian, A Loundou, L Guyot
INTRODUCTION: Surrounded by a variety of structures including the facial sinuses and the brain, the human orbit displays unique anatomical features. It is known that orbital volume correlates with age and sex. The aim of this study was to evaluate sexual dimorphism of orbital volume relative to the size of the skull, and to establish criteria for gender determination. METHODS: Orbital volume was measured from 3D models of the orbits. The volumes were expressed in relation to the centroid size of the skull, to ensure that any sexual dimorphism in orbital volume was not simply due to a difference in skull size...
February 2017: J Stomatol Oral Maxillofac Surg
https://www.readbyqxmd.com/read/28329909/testing-the-boundaries-of-boundary-extension-anticipatory-scene-representation-across-development-and-disorder
#12
G Spanò, H Intraub, J O Edgin
Recent studies have suggested that Boundary Extension (BE), a scene construction error, may be linked to the function of the hippocampus. In this study, we tested BE in two groups with variations in hippocampal development and disorder: a typically developing sample ranging from preschool to adolescence and individuals with Down syndrome. We assessed BE across three different test modalities: drawing, visual recognition, and a 3D scene boundary reconstruction task. Despite confirmed fluctuations in memory function measured through a neuropsychological assessment, the results showed consistent BE in all groups across test modalities, confirming the near universal nature of BE...
March 22, 2017: Hippocampus
https://www.readbyqxmd.com/read/28329338/successful-treatment-of-bronchial-stenosis-after-lung-transplantation
#13
Irene T Schrijver, Bart Luijk, Ronald C A Meijer, Linda M de Heer
Treatment of stenotic anastomosis after lung transplantation can be challenging. In this case report, we present a case in which 3D computed tomography reconstructions guided the clinical decision towards operative bronchoplasty after which our patient was treated successfully.
February 23, 2017: Interactive Cardiovascular and Thoracic Surgery
https://www.readbyqxmd.com/read/28329229/isolated-severe-leftward-displacement-of-the-septum-primum-anatomic-and-3d-echocardiographic-findings-and-surgical-repair
#14
Fabio Cuttone, Khaled Hadeed, François Lacour-Gayet, Hugues Lucron, Sebastien Hascoet, Philippe Acar, Bertrand Leobon, Richard Van Praagh
OBJECTIVES: Leftward displacement of the septum primum is usually described as associated with hypoplastic left heart syndrome or visceral heterotaxy. This rare malformation results in partially or totally anomalous pulmonary venous drainage with a normal connection of the pulmonary veins to the left atrium, depending on the degree of septal shift. We report the 3D echocardiographic and anatomic findings as well as the surgical repair in a series of isolated severe leftward displacement of the septum primum, responsible for totally anomalous pulmonary venous drainage...
February 16, 2017: Interactive Cardiovascular and Thoracic Surgery
https://www.readbyqxmd.com/read/28329105/medical-three-dimensional-printing-opens-up-new-opportunities-in-cardiology-and-cardiac-surgery
#15
Thomas Bartel, Andrew Rivard, Alejandro Jimenez, Carlos A Mestres, Silvana Müller
Advanced percutaneous and surgical procedures in structural and congenital heart disease require precise pre-procedural planning and continuous quality control. Although current imaging modalities and post-processing software assists with peri-procedural guidance, their capabilities for spatial conceptualization remain limited in two- and three-dimensional representations. In contrast, 3D printing offers not only improved visualization for procedural planning, but provides substantial information on the accuracy of surgical reconstruction and device implantations...
February 16, 2017: European Heart Journal
https://www.readbyqxmd.com/read/28328931/x-ray-microtomography-for-ant-taxonomy-an-exploration-and-case-study-with-two-new-terataner-hymenoptera-formicidae-myrmicinae-species-from-madagascar
#16
Francisco Hita Garcia, Georg Fischer, Cong Liu, Tracy L Audisio, Gary D Alpert, Brian L Fisher, Evan P Economo
We explore the potential of x-ray micro computed tomography (μCT) for the field of ant taxonomy by using it to enhance the descriptions of two remarkable new species of the ant genus Terataner: T. balrog sp. n. and T. nymeria sp. n.. We provide an illustrated worker-based species identification key for all species found on Madagascar, as well as detailed taxonomic descriptions, which include diagnoses, discussions, measurements, natural history data, high-quality montage images and distribution maps for both new species...
2017: PloS One
https://www.readbyqxmd.com/read/28328637/estimating-implant-volume-and-mastectomy-specimen-volume-by-measuring-breast-volume-with-a-3-dimensional-scanner
#17
Hiroki Utsunomiya, Taro Kusano, Nobuhiro Sato, Shinya Yoshimoto
OBJECTIVES: Conventional 2-stage expander-implant breast reconstruction is frequently performed. However, direct to implant reconstruction should be considered if indicated and if circumstances allow. One difficulty in breast reconstruction postmastectomy is selection of the appropriate implant size prior to surgery. The ability to estimate implant volume and mastectomy-specimen volume from the preoperative breast volume using a 3-dimensional (3D) scanner would greatly facilitate reconstruction...
March 21, 2017: Annals of Plastic Surgery
https://www.readbyqxmd.com/read/28328041/sem-microphotogrammetry-a-new-take-on-an-old-method-for-generating-high-resolution-3d-models-from-sem-images
#18
A D Ball, P A Job, A E L Walker
The method we present here uses a scanning electron microscope programmed via macros to automatically capture dozens of images at suitable angles to generate accurate, detailed three-dimensional (3D) surface models with micron-scale resolution. We demonstrate that it is possible to use these Scanning Electron Microscope (SEM) images in conjunction with commercially available software originally developed for photogrammetry reconstructions from Digital Single Lens Reflex (DSLR) cameras and to reconstruct 3D models of the specimen...
March 22, 2017: Journal of Microscopy
https://www.readbyqxmd.com/read/28327210/new-atom-probe-tomography-reconstruction-algorithm-for-multilayered-samples-beyond-the-hemispherical-constraint
#19
Nicolas Rolland, François Vurpillot, Sébastien Duguay, Baishakhi Mazumder, James S Speck, Didier Blavette
Accuracy of atom probe tomography measurements is strongly degraded by the presence of phases that have different evaporation fields. In particular, when there are perpendicular interfaces to the tip axis in the specimen, layers thicknesses are systematically biased and the resolution is degraded near the interfaces. Based on an analytical model of field evaporated emitter end-form, a new algorithm dedicated to the 3D reconstruction of multilayered samples was developed. Simulations of field evaporation of bilayer were performed to evaluate the effectiveness of the new algorithm...
March 22, 2017: Microscopy and Microanalysis
https://www.readbyqxmd.com/read/28326349/quantitative-in-vivo-micro-computed-tomography-for-assessment-of-age-dependent-changes-in-murine-whole-body-composition
#20
Kim L Beaucage, Steven I Pollmann, Stephen M Sims, S Jeffrey Dixon, David W Holdsworth
Micro-computed tomography (micro-CT) is used routinely to quantify skeletal tissue mass in small animal models. Our goal was to evaluate repeated in vivo micro-CT imaging for monitoring whole-body composition in studies of growth and aging in mice. Male mice from 2 to 52 weeks of age were anesthetized and imaged using an eXplore Locus Ultra and/or eXplore speCZT scanner. Images were reconstructed into 3D volumes, signal-intensity thresholds were used to classify each voxel as adipose, lean or skeletal tissue, and tissue masses were calculated from known density values...
December 2016: Bone Reports
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