WorldWideScience

Sample records for lensfree tomographic microscope

  1. Mesooptical microscope as a tomographical device

    International Nuclear Information System (INIS)

    Soroko, L.M.

    1989-01-01

    It is shown that there are at least four regions which are common for the mesooptical microscopes, on the one hand, and for the reconstructed tomography, on the other hand. The following characteristics of the mesooptical microscope show the tomographical properties: the structure of the output data concerning the orientation and the position in space of the straight-line objects going at small angles with the perpendicular to the given tomographic plane, the behaviour of the two-dimensional fourier-transform of the straight-line object in the course of the rotation of this object with respect to the specified axis in space, the scanning algorithm of the nuclear emulsion volume by the fence-like illuminated region in the mesooptical microscope for searching for particle tracks going parallel to the optical axis of the microscope, and, finally, the fact that the mesooptical images of the straight-line particle tracks with a common vertex in the nuclear emulsion lie on the sinogram. 12 refs.; 16 figs

  2. Lensfree optofluidic microscopy and tomography.

    Science.gov (United States)

    Bishara, Waheb; Isikman, Serhan O; Ozcan, Aydogan

    2012-02-01

    Microfluidic devices aim at miniaturizing, automating, and lowering the cost of chemical and biological sample manipulation and detection, hence creating new opportunities for lab-on-a-chip platforms. Recently, optofluidic devices have also emerged where optics is used to enhance the functionality and the performance of microfluidic components in general. Lensfree imaging within microfluidic channels is one such optofluidic platform, and in this article, we focus on the holographic implementation of lensfree optofluidic microscopy and tomography, which might provide a simpler and more powerful solution for three-dimensional (3D) on-chip imaging. This lensfree optofluidic imaging platform utilizes partially coherent digital in-line holography to allow phase and amplitude imaging of specimens flowing through micro-channels, and takes advantage of the fluidic flow to achieve higher spatial resolution imaging compared to a stationary specimen on the same chip. In addition to this, 3D tomographic images of the same samples can also be reconstructed by capturing lensfree projection images of the samples at various illumination angles as a function of the fluidic flow. Based on lensfree digital holographic imaging, this optofluidic microscopy and tomography concept could be valuable especially for providing a compact, yet powerful toolset for lab-on-a-chip devices.

  3. Line-scanning tomographic optical microscope with isotropic transfer function

    International Nuclear Information System (INIS)

    Gajdátsy, Gábor; Dudás, László; Erdélyi, Miklós; Szabó, Gábor

    2010-01-01

    An imaging method and optical system, referred to as a line-scanning tomographic optical microscope (LSTOM) using a combination of line-scanning technique and CT reconstruction principle, is proposed and studied theoretically and experimentally. In our implementation a narrow focus line is scanned over the sample and the reflected light is measured in a confocal arrangement. One such scan is equivalent to a transverse projection in tomography. Repeating the scanning procedure in several directions, a number of transverse projections are recorded from which the image can be obtained using conventional CT reconstruction algorithms. The resolution of the image is independent of the spatial dimensions and structure of the applied detector; furthermore, the transfer function of the system is isotropic. The imaging performance of the implemented confocal LSTOM was compared with a point-scanning confocal microscope, based on recorded images. These images demonstrate that the resolution of the confocal LSTOM exceeds (by 15%) the resolution limit of a point-scanning confocal microscope

  4. Automated Micro-Object Detection for Mobile Diagnostics Using Lens-Free Imaging Technology

    Directory of Open Access Journals (Sweden)

    Mohendra Roy

    2016-05-01

    Full Text Available Lens-free imaging technology has been extensively used recently for microparticle and biological cell analysis because of its high throughput, low cost, and simple and compact arrangement. However, this technology still lacks a dedicated and automated detection system. In this paper, we describe a custom-developed automated micro-object detection method for a lens-free imaging system. In our previous work (Roy et al., we developed a lens-free imaging system using low-cost components. This system was used to generate and capture the diffraction patterns of micro-objects and a global threshold was used to locate the diffraction patterns. In this work we used the same setup to develop an improved automated detection and analysis algorithm based on adaptive threshold and clustering of signals. For this purpose images from the lens-free system were then used to understand the features and characteristics of the diffraction patterns of several types of samples. On the basis of this information, we custom-developed an automated algorithm for the lens-free imaging system. Next, all the lens-free images were processed using this custom-developed automated algorithm. The performance of this approach was evaluated by comparing the counting results with standard optical microscope results. We evaluated the counting results for polystyrene microbeads, red blood cells, and HepG2, HeLa, and MCF7 cells. The comparison shows good agreement between the systems, with a correlation coefficient of 0.91 and linearity slope of 0.877. We also evaluated the automated size profiles of the microparticle samples. This Wi-Fi-enabled lens-free imaging system, along with the dedicated software, possesses great potential for telemedicine applications in resource-limited settings.

  5. Giga-pixel lensfree holographic microscopy and tomography using color image sensors.

    Directory of Open Access Journals (Sweden)

    Serhan O Isikman

    Full Text Available We report Giga-pixel lensfree holographic microscopy and tomography using color sensor-arrays such as CMOS imagers that exhibit Bayer color filter patterns. Without physically removing these color filters coated on the sensor chip, we synthesize pixel super-resolved lensfree holograms, which are then reconstructed to achieve ~350 nm lateral resolution, corresponding to a numerical aperture of ~0.8, across a field-of-view of ~20.5 mm(2. This constitutes a digital image with ~0.7 Billion effective pixels in both amplitude and phase channels (i.e., ~1.4 Giga-pixels total. Furthermore, by changing the illumination angle (e.g., ± 50° and scanning a partially-coherent light source across two orthogonal axes, super-resolved images of the same specimen from different viewing angles are created, which are then digitally combined to synthesize tomographic images of the object. Using this dual-axis lensfree tomographic imager running on a color sensor-chip, we achieve a 3D spatial resolution of ~0.35 µm × 0.35 µm × ~2 µm, in x, y and z, respectively, creating an effective voxel size of ~0.03 µm(3 across a sample volume of ~5 mm(3, which is equivalent to >150 Billion voxels. We demonstrate the proof-of-concept of this lensfree optical tomographic microscopy platform on a color CMOS image sensor by creating tomograms of micro-particles as well as a wild-type C. elegans nematode.

  6. Whole slide imaging of unstained tissue using lensfree microscopy

    Science.gov (United States)

    Morel, Sophie Nhu An; Hervé, Lionel; Bordy, Thomas; Cioni, Olivier; Delon, Antoine; Fromentin, Catherine; Dinten, Jean-Marc; Allier, Cédric

    2016-04-01

    Pathologist examination of tissue slides provides insightful information about a patient's disease. Traditional analysis of tissue slides is performed under a binocular microscope, which requires staining of the sample and delays the examination. We present a simple cost-effective lensfree imaging method to record 2-4μm resolution wide-field (10 mm2 to 6 cm2) images of unstained tissue slides. The sample processing time is reduced as there is no need for staining. A wide field of view (10 mm2) lensfree hologram is recorded in a single shot and the image is reconstructed in 2s providing a very fast acquisition chain. The acquisition is multispectral, i.e. multiple holograms are recorded simultaneously at three different wavelengths, and a dedicated holographic reconstruction algorithm is used to retrieve both amplitude and phase. Whole tissue slides imaging is obtained by recording 130 holograms with X-Y translation stages and by computing the mosaic of a 25 x 25 mm2 reconstructed image. The reconstructed phase provides a phase-contrast-like image of the unstained specimen, revealing structures of healthy and diseased tissue. Slides from various organs can be reconstructed, e.g. lung, colon, ganglion, etc. To our knowledge, our method is the first technique that enables fast wide-field lensfree imaging of such unlabeled dense samples. This technique is much cheaper and compact than a conventional phase contrast microscope and could be made portable. In sum, we present a new methodology that could quickly provide useful information when a rapid diagnosis is needed, such as tumor margin identification on frozen section biopsies during surgery.

  7. A distributed multi-GPU system for high speed electron microscopic tomographic reconstruction.

    Science.gov (United States)

    Zheng, Shawn Q; Branlund, Eric; Kesthelyi, Bettina; Braunfeld, Michael B; Cheng, Yifan; Sedat, John W; Agard, David A

    2011-07-01

    Full resolution electron microscopic tomographic (EMT) reconstruction of large-scale tilt series requires significant computing power. The desire to perform multiple cycles of iterative reconstruction and realignment dramatically increases the pressing need to improve reconstruction performance. This has motivated us to develop a distributed multi-GPU (graphics processing unit) system to provide the required computing power for rapid constrained, iterative reconstructions of very large three-dimensional (3D) volumes. The participating GPUs reconstruct segments of the volume in parallel, and subsequently, the segments are assembled to form the complete 3D volume. Owing to its power and versatility, the CUDA (NVIDIA, USA) platform was selected for GPU implementation of the EMT reconstruction. For a system containing 10 GPUs provided by 5 GTX295 cards, 10 cycles of SIRT reconstruction for a tomogram of 4096(2) × 512 voxels from an input tilt series containing 122 projection images of 4096(2) pixels (single precision float) takes a total of 1845 s of which 1032 s are for computation with the remainder being the system overhead. The same system takes only 39 s total to reconstruct 1024(2) × 256 voxels from 122 1024(2) pixel projections. While the system overhead is non-trivial, performance analysis indicates that adding extra GPUs to the system would lead to steadily enhanced overall performance. Therefore, this system can be easily expanded to generate superior computing power for very large tomographic reconstructions and especially to empower iterative cycles of reconstruction and realignment. Copyright © 2011 Elsevier B.V. All rights reserved.

  8. Lensfree Computational Microscopy Tools and their Biomedical Applications

    Science.gov (United States)

    Sencan, Ikbal

    Conventional microscopy has been a revolutionary tool for biomedical applications since its invention several centuries ago. Ability to non-destructively observe very fine details of biological objects in real time enabled to answer many important questions about their structures and functions. Unfortunately, most of these advance microscopes are complex, bulky, expensive, and/or hard to operate, so they could not reach beyond the walls of well-equipped laboratories. Recent improvements in optoelectronic components and computational methods allow creating imaging systems that better fulfill the specific needs of clinics or research related biomedical applications. In this respect, lensfree computational microscopy aims to replace bulky and expensive optical components with compact and cost-effective alternatives through the use of computation, which can be particularly useful for lab-on-a-chip platforms as well as imaging applications in low-resource settings. Several high-throughput on-chip platforms are built with this approach for applications including, but not limited to, cytometry, micro-array imaging, rare cell analysis, telemedicine, and water quality screening. The lack of optical complexity in these lensfree on-chip imaging platforms is compensated by using computational techniques. These computational methods are utilized for various purposes in coherent, incoherent and fluorescent on-chip imaging platforms e.g. improving the spatial resolution, to undo the light diffraction without using lenses, localization of objects in a large volume and retrieval of the phase or the color/spectral content of the objects. For instance, pixel super resolution approaches based on source shifting are used in lensfree imaging platforms to prevent under sampling, Bayer pattern, and aliasing artifacts. Another method, iterative phase retrieval, is utilized to compensate the lack of lenses by undoing the diffraction and removing the twin image noise of in-line holograms

  9. Wide-field computational imaging of pathology slides using lens-free on-chip microscopy.

    Science.gov (United States)

    Greenbaum, Alon; Zhang, Yibo; Feizi, Alborz; Chung, Ping-Luen; Luo, Wei; Kandukuri, Shivani R; Ozcan, Aydogan

    2014-12-17

    Optical examination of microscale features in pathology slides is one of the gold standards to diagnose disease. However, the use of conventional light microscopes is partially limited owing to their relatively high cost, bulkiness of lens-based optics, small field of view (FOV), and requirements for lateral scanning and three-dimensional (3D) focus adjustment. We illustrate the performance of a computational lens-free, holographic on-chip microscope that uses the transport-of-intensity equation, multi-height iterative phase retrieval, and rotational field transformations to perform wide-FOV imaging of pathology samples with comparable image quality to a traditional transmission lens-based microscope. The holographically reconstructed image can be digitally focused at any depth within the object FOV (after image capture) without the need for mechanical focus adjustment and is also digitally corrected for artifacts arising from uncontrolled tilting and height variations between the sample and sensor planes. Using this lens-free on-chip microscope, we successfully imaged invasive carcinoma cells within human breast sections, Papanicolaou smears revealing a high-grade squamous intraepithelial lesion, and sickle cell anemia blood smears over a FOV of 20.5 mm(2). The resulting wide-field lens-free images had sufficient image resolution and contrast for clinical evaluation, as demonstrated by a pathologist's blinded diagnosis of breast cancer tissue samples, achieving an overall accuracy of ~99%. By providing high-resolution images of large-area pathology samples with 3D digital focus adjustment, lens-free on-chip microscopy can be useful in resource-limited and point-of-care settings. Copyright © 2014, American Association for the Advancement of Science.

  10. Pixel-super-resolved lensfree holography using adaptive relaxation factor and positional error correction

    Science.gov (United States)

    Zhang, Jialin; Chen, Qian; Sun, Jiasong; Li, Jiaji; Zuo, Chao

    2018-01-01

    Lensfree holography provides a new way to effectively bypass the intrinsical trade-off between the spatial resolution and field-of-view (FOV) of conventional lens-based microscopes. Unfortunately, due to the limited sensor pixel-size, unpredictable disturbance during image acquisition, and sub-optimum solution to the phase retrieval problem, typical lensfree microscopes only produce compromised imaging quality in terms of lateral resolution and signal-to-noise ratio (SNR). In this paper, we propose an adaptive pixel-super-resolved lensfree imaging (APLI) method to address the pixel aliasing problem by Z-scanning only, without resorting to subpixel shifting or beam-angle manipulation. Furthermore, an automatic positional error correction algorithm and adaptive relaxation strategy are introduced to enhance the robustness and SNR of reconstruction significantly. Based on APLI, we perform full-FOV reconstruction of a USAF resolution target across a wide imaging area of {29.85 mm2 and achieve half-pitch lateral resolution of 770 nm, surpassing 2.17 times of the theoretical Nyquist-Shannon sampling resolution limit imposed by the sensor pixel-size (1.67 μm). Full-FOV imaging result of a typical dicot root is also provided to demonstrate its promising potential applications in biologic imaging.

  11. Optimized computational imaging methods for small-target sensing in lens-free holographic microscopy

    Science.gov (United States)

    Xiong, Zhen; Engle, Isaiah; Garan, Jacob; Melzer, Jeffrey E.; McLeod, Euan

    2018-02-01

    Lens-free holographic microscopy is a promising diagnostic approach because it is cost-effective, compact, and suitable for point-of-care applications, while providing high resolution together with an ultra-large field-of-view. It has been applied to biomedical sensing, where larger targets like eukaryotic cells, bacteria, or viruses can be directly imaged without labels, and smaller targets like proteins or DNA strands can be detected via scattering labels like micro- or nano-spheres. Automated image processing routines can count objects and infer target concentrations. In these sensing applications, sensitivity and specificity are critically affected by image resolution and signal-to-noise ratio (SNR). Pixel super-resolution approaches have been shown to boost resolution and SNR by synthesizing a high-resolution image from multiple, partially redundant, low-resolution images. However, there are several computational methods that can be used to synthesize the high-resolution image, and previously, it has been unclear which methods work best for the particular case of small-particle sensing. Here, we quantify the SNR achieved in small-particle sensing using regularized gradient-descent optimization method, where the regularization is based on cardinal-neighbor differences, Bayer-pattern noise reduction, or sparsity in the image. In particular, we find that gradient-descent with sparsity-based regularization works best for small-particle sensing. These computational approaches were evaluated on images acquired using a lens-free microscope that we assembled from an off-the-shelf LED array and color image sensor. Compared to other lens-free imaging systems, our hardware integration, calibration, and sample preparation are particularly simple. We believe our results will help to enable the best performance in lens-free holographic sensing.

  12. Development of full-field x-ray phase-tomographic microscope based on laboratory x-ray source

    Science.gov (United States)

    Takano, H.; Wu, Y.; Momose, A.

    2017-09-01

    An X-ray phase tomographic microscope that can quantitatively measure the refractive index of a sample in three dimensions with a high spatial resolution was developed by installing a Lau interferometer consisting of an absorption grating and a π/2 phase grating into the optics of an X-ray microscope. The optics comprises a Cu rotating anode X-ray source, capillary condenser optics, and a Fresnel zone plate for the objective. The microscope has two optical modes: a large-field-of-view mode (field of view: 65 μm x 65 μm) and a high-resolution mode (spatial resolution: 50 nm). Optimizing the parameters of the interferometer yields a self-image of the phase grating with 60% visibility. Through the normal fringe-scanning measurement, a twin phase image, which has an overlap of two phase image of opposite contrast with a shear distance much larger than system resolution, is generated. Although artifacts remain to some extent currently when a phase image is calculated from the twin phase image, this system can obtain high-spatial-resolution images resolving 50-nm structures. Phase tomography with this system has also been demonstrated using a phase object.

  13. Fusion of lens-free microscopy and mobile-phone microscopy images for high-color-accuracy and high-resolution pathology imaging

    Science.gov (United States)

    Zhang, Yibo; Wu, Yichen; Zhang, Yun; Ozcan, Aydogan

    2017-03-01

    Digital pathology and telepathology require imaging tools with high-throughput, high-resolution and accurate color reproduction. Lens-free on-chip microscopy based on digital in-line holography is a promising technique towards these needs, as it offers a wide field of view (FOV >20 mm2) and high resolution with a compact, low-cost and portable setup. Color imaging has been previously demonstrated by combining reconstructed images at three discrete wavelengths in the red, green and blue parts of the visible spectrum, i.e., the RGB combination method. However, this RGB combination method is subject to color distortions. To improve the color performance of lens-free microscopy for pathology imaging, here we present a wavelet-based color fusion imaging framework, termed "digital color fusion microscopy" (DCFM), which digitally fuses together a grayscale lens-free microscope image taken at a single wavelength and a low-resolution and low-magnification color-calibrated image taken by a lens-based microscope, which can simply be a mobile phone based cost-effective microscope. We show that the imaging results of an H&E stained breast cancer tissue slide with the DCFM technique come very close to a color-calibrated microscope using a 40x objective lens with 0.75 NA. Quantitative comparison showed 2-fold reduction in the mean color distance using the DCFM method compared to the RGB combination method, while also preserving the high-resolution features of the lens-free microscope. Due to the cost-effective and field-portable nature of both lens-free and mobile-phone microscopy techniques, their combination through the DCFM framework could be useful for digital pathology and telepathology applications, in low-resource and point-of-care settings.

  14. Wide-field synovial fluid imaging using polarized lens-free on-chip microscopy for point-of-care diagnostics of gout (Conference Presentation)

    Science.gov (United States)

    Zhang, Yibo; Lee, Seung Yoon; Zhang, Yun; Furst, Daniel; Fitzgerald, John; Ozcan, Aydogan

    2016-03-01

    Gout and pseudogout are forms of crystal arthropathy caused by monosodium urate (MSU) and calcium pyrophosphate dehydrate (CPPD) crystals in the joint, respectively, that can result in painful joints. Detecting the unique-shaped, birefringent MSU/CPPD crystals in a synovial fluid sample using a compensated polarizing microscope has been the gold-standard for diagnosis since the 1960's. However, this can be time-consuming and inaccurate, especially if there are only few crystals in the fluid. The high-cost and bulkiness of conventional microscopes can also be limiting for point-of-care diagnosis. Lens-free on-chip microscopy based on digital holography routinely achieves high-throughput and high-resolution imaging in a cost-effective and field-portable design. Here we demonstrate, for the first time, polarized lens-free on-chip imaging of MSU and CPPD crystals over a wide field-of-view (FOV ~ 20.5 mm2, i.e., slide, after which a quarter-wave-plate and an angle-mismatched linear polarizer are used to analyze the transmitted light. Two lens-free holograms of the MSU/CPPD sample are taken, with the sample rotated by 90°, to rule out any non-birefringent objects within the specimen. A phase-recovery algorithm is also used to improve the reconstruction quality, and digital pseudo-coloring is utilized to match the color and contrast of the lens-free image to that of a gold-standard microscope image to ease the examination by a rheumatologist or a laboratory technician, and to facilitate computerized analysis.

  15. Color calibration and fusion of lens-free and mobile-phone microscopy images for high-resolution and accurate color reproduction

    Science.gov (United States)

    Zhang, Yibo; Wu, Yichen; Zhang, Yun; Ozcan, Aydogan

    2016-06-01

    Lens-free holographic microscopy can achieve wide-field imaging in a cost-effective and field-portable setup, making it a promising technique for point-of-care and telepathology applications. However, due to relatively narrow-band sources used in holographic microscopy, conventional colorization methods that use images reconstructed at discrete wavelengths, corresponding to e.g., red (R), green (G) and blue (B) channels, are subject to color artifacts. Furthermore, these existing RGB colorization methods do not match the chromatic perception of human vision. Here we present a high-color-fidelity and high-resolution imaging method, termed “digital color fusion microscopy” (DCFM), which fuses a holographic image acquired at a single wavelength with a color-calibrated image taken by a low-magnification lens-based microscope using a wavelet transform-based colorization method. We demonstrate accurate color reproduction of DCFM by imaging stained tissue sections. In particular we show that a lens-free holographic microscope in combination with a cost-effective mobile-phone-based microscope can generate color images of specimens, performing very close to a high numerical-aperture (NA) benchtop microscope that is corrected for color distortions and chromatic aberrations, also matching the chromatic response of human vision. This method can be useful for wide-field imaging needs in telepathology applications and in resource-limited settings, where whole-slide scanning microscopy systems are not available.

  16. Electrostatic simulations of a local electrode atom probe: the dependence of tomographic reconstruction parameters on specimen and microscope geometry.

    Science.gov (United States)

    Loi, Shyeh Tjing; Gault, Baptiste; Ringer, Simon P; Larson, David J; Geiser, Brian P

    2013-09-01

    We electrostatically model a local electrode atom probe microscope using the commercial software IES LORENTZ 2D v9.0 to investigate factors affecting the reconstruction parameters. We find strong dependences on the specimen geometry and voltage, and moderate dependences on the tip-aperture separation, which confirm that the current approach to atom probe reconstruction overlooks too many factors. Based on our data, which are in excellent agreement with known trends and experimental results, we derive a set of empirical relations which predict the values of the reconstruction parameters. These may be used to advance current reconstruction protocols by enabling the parameters to be adjusted as the specimen geometry changes. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. Yeast viability and concentration analysis using lens-free computational microscopy and machine learning

    Science.gov (United States)

    Feizi, Alborz; Zhang, Yibo; Greenbaum, Alon; Guziak, Alex; Luong, Michelle; Chan, Raymond Yan Lok; Berg, Brandon; Ozkan, Haydar; Luo, Wei; Wu, Michael; Wu, Yichen; Ozcan, Aydogan

    2017-03-01

    Research laboratories and the industry rely on yeast viability and concentration measurements to adjust fermentation parameters such as pH, temperature, and pressure. Beer-brewing processes as well as biofuel production can especially utilize a cost-effective and portable way of obtaining data on cell viability and concentration. However, current methods of analysis are relatively costly and tedious. Here, we demonstrate a rapid, portable, and cost-effective platform for imaging and measuring viability and concentration of yeast cells. Our platform features a lens-free microscope that weighs 70 g and has dimensions of 12 × 4 × 4 cm. A partially-coherent illumination source (a light-emitting-diode), a band-pass optical filter, and a multimode optical fiber are used to illuminate the sample. The yeast sample is directly placed on a complementary metal-oxide semiconductor (CMOS) image sensor chip, which captures an in-line hologram of the sample over a large field-of-view of >20 mm2. The hologram is transferred to a touch-screen interface, where a trained Support Vector Machine model classifies yeast cells stained with methylene blue as live or dead and measures cell viability as well as concentration. We tested the accuracy of our platform against manual counting of live and dead cells using fluorescent exclusion staining and a bench-top fluorescence microscope. Our regression analysis showed no significant difference between the two methods within a concentration range of 1.4 × 105 to 1.4 × 106 cells/mL. This compact and cost-effective yeast analysis platform will enable automatic quantification of yeast viability and concentration in field settings and resource-limited environments.

  18. New Lens-Free X-ray Source for Laboratory Nano-CT with 50-nm Spatial Resolution

    Science.gov (United States)

    Sasov, A.; Pauwels, B.; Bruyndonckx, P.; Liu, X.

    2011-09-01

    X-ray optics, such as zone plates, are often used to obtain a spatial resolution better than 100 nm in x-ray projection images. Such types of optics are not always suited for tomographic imaging due to their limited depth of focus, which restricts the size of the specimen to a few microns. To overcome these limitations, we developed a new lens-free setup for a nano-CT system. Spatial resolution of nano-CT systems is mainly defined by x-ray source performance. It is dependent on target shape and focusing of the electron beam. The typical way to improve spatial resolution is based on replacement of the bulk metal target to thin film. It allows getting submicron spot size, but significantly reduces x-ray flux. To overcome flux limitation without compromising with spatial resolution, we invented a new type of target shaped as a rod or needle towards the camera. It allows us to reach 50-nm resolution with reasonable flux.

  19. Rapid, portable and cost-effective yeast cell viability and concentration analysis using lensfree on-chip microscopy and machine learning

    KAUST Repository

    Feizi, Alborz

    2016-09-24

    Monitoring yeast cell viability and concentration is important in brewing, baking and biofuel production. However, existing methods of measuring viability and concentration are relatively bulky, tedious and expensive. Here we demonstrate a compact and cost-effective automatic yeast analysis platform (AYAP), which can rapidly measure cell concentration and viability. AYAP is based on digital in-line holography and on-chip microscopy and rapidly images a large field-of-view of 22.5 mm2. This lens-free microscope weighs 70 g and utilizes a partially-coherent illumination source and an opto-electronic image sensor chip. A touch-screen user interface based on a tablet-PC is developed to reconstruct the holographic shadows captured by the image sensor chip and use a support vector machine (SVM) model to automatically classify live and dead cells in a yeast sample stained with methylene blue. In order to quantify its accuracy, we varied the viability and concentration of the cells and compared AYAP\\'s performance with a fluorescence exclusion staining based gold-standard using regression analysis. The results agree very well with this gold-standard method and no significant difference was observed between the two methods within a concentration range of 1.4 × 105 to 1.4 × 106 cells per mL, providing a dynamic range suitable for various applications. This lensfree computational imaging technology that is coupled with machine learning algorithms would be useful for cost-effective and rapid quantification of cell viability and density even in field and resource-poor settings.

  20. Tomographic imaging

    International Nuclear Information System (INIS)

    Newman, M.A.

    1989-01-01

    Tomographic images of an object or scene are produced by an analysis of two or more stereographic images of the scene including shifting one image laterally with respect to another and logically summing the image data sets. Several image processing, edge enhancement and edge extraction algorithms may be applied to the images in digitised video data form to provide wire-frame or skeleton type representations of each of the original images. Tomographic images of planes not parallel with the image plane (or normal to the camera axes) may be produced by changing the magnification of one image prior to logical summing. The images may be generated by three video cameras arranged on two orthogonal axes for elimination of spurious coincidences. The images are preferably produced using X-rays. (author)

  1. Tomographic array

    International Nuclear Information System (INIS)

    1976-01-01

    The configuration of a tomographic array in which the object can rotate about its axis is described. The X-ray detector is a cylindrical screen perpendicular to the axis of rotation. The X-ray source has a line-shaped focus coinciding with the axis of rotation. The beam is fan-shaped with one side of this fan lying along the axis of rotation. The detector screen is placed inside an X-ray image multiplier tube

  2. Tomographic array

    International Nuclear Information System (INIS)

    1976-01-01

    A tomographic array with the following characteristics is described. An X-ray screen serving as detector is placed before a photomultiplier tube which itself is placed in front of a television camera connected to a set of image processors. The detector is concave towards the source and is replacable. Different images of the object are obtained simultaneously. Optical fibers and lenses are used for transmission within the system

  3. Field-portable pixel super-resolution colour microscope.

    Directory of Open Access Journals (Sweden)

    Alon Greenbaum

    Full Text Available Based on partially-coherent digital in-line holography, we report a field-portable microscope that can render lensfree colour images over a wide field-of-view of e.g., >20 mm(2. This computational holographic microscope weighs less than 145 grams with dimensions smaller than 17×6×5 cm, making it especially suitable for field settings and point-of-care use. In this lensfree imaging design, we merged a colorization algorithm with a source shifting based multi-height pixel super-resolution technique to mitigate 'rainbow' like colour artefacts that are typical in holographic imaging. This image processing scheme is based on transforming the colour components of an RGB image into YUV colour space, which separates colour information from brightness component of an image. The resolution of our super-resolution colour microscope was characterized using a USAF test chart to confirm sub-micron spatial resolution, even for reconstructions that employ multi-height phase recovery to handle dense and connected objects. To further demonstrate the performance of this colour microscope Papanicolaou (Pap smears were also successfully imaged. This field-portable and wide-field computational colour microscope could be useful for tele-medicine applications in resource poor settings.

  4. Sparsity-Based Pixel Super Resolution for Lens-Free Digital In-line Holography.

    Science.gov (United States)

    Song, Jun; Leon Swisher, Christine; Im, Hyungsoon; Jeong, Sangmoo; Pathania, Divya; Iwamoto, Yoshiko; Pivovarov, Misha; Weissleder, Ralph; Lee, Hakho

    2016-04-21

    Lens-free digital in-line holography (LDIH) is a promising technology for portable, wide field-of-view imaging. Its resolution, however, is limited by the inherent pixel size of an imaging device. Here we present a new computational approach to achieve sub-pixel resolution for LDIH. The developed method is a sparsity-based reconstruction with the capability to handle the non-linear nature of LDIH. We systematically characterized the algorithm through simulation and LDIH imaging studies. The method achieved the spatial resolution down to one-third of the pixel size, while requiring only single-frame imaging without any hardware modifications. This new approach can be used as a general framework to enhance the resolution in nonlinear holographic systems.

  5. Dynamics of cell and tissue growth acquired by means of extended field of view lensfree microscopy.

    Science.gov (United States)

    Momey, F; Coutard, J-G; Bordy, T; Navarro, F; Menneteau, M; Dinten, J-M; Allier, C

    2016-02-01

    In this paper, we discuss a new methodology based on lensfree imaging to perform wound healing assay with unprecedented statistics. Our video lensfree microscopy setup is a simple device featuring only a CMOS sensor and a semi coherent illumination system. Yet it is a powerful mean for the real-time monitoring of cultivated cells. It presents several key advantages, e.g. integration into standard incubator, compatibility with standard cell culture protocol, simplicity and ease of use. It can perform the follow-up in a large field of view (25 mm(2)) of several crucial parameters during the culture of cells i.e. their motility, their proliferation rate or their death. Consequently the setup can gather large statistics both in space and time. Here we uses this facility in the context of wound healing assay to perform label-free measurements of the velocities of the fronts of proliferation of the cell layer as a function of time by means of particle image velocimetry (PIV) processing. However, for such tissue growth experiments, the field of view of 25 mm(2) remains not sufficient and results can be biased depending on the position of the device with respect to the recipient of the cell culture. Hence, to conduct exhaustive wound healing assays, we propose to enlarge the field of view up to 10 cm(2) through a raster scan, by moving the source/sensor with respect to the Petri dish. We have performed acquisitions of wound healing assay (keratinocytes HaCaT) both in real-time (25 mm(2)) and in final point (10 cm(2)) to assess the combination of velocimetry measurements and final point wide field imaging. In the future, we aim at combining directly our extended field of view acquisitions (>10 cm(2)) with real time ability inside the incubator.

  6. Advances in tomographic PIV

    NARCIS (Netherlands)

    Novara, M.

    2013-01-01

    This research deals with advanced developments in 3D particle image velocimetry based on the tomographic PIV technique (Tomo-PIV). The latter is a relatively recent measurement technique introduced by Elsinga et al. in 2005, which is based on the tomographic reconstruction of particle tracers in

  7. Escherichia coli counting using lens-free imaging for sepsis diagnosis

    Science.gov (United States)

    Moon, Sangjun; Manzur, Fahim; Manzur, Tariq; Klapperich, Catherine; Demirci, Utkan

    2009-09-01

    Sepsis causes 9.3% of overall deaths in United States. To diagnose sepsis, cell/bacteria capture and culturing methods have been widely investigated in the medical field. Escherichia Coli (E. Coli) is used as a model organism for sepsis in blood stream since wide variety of antibodies are established and the genetic modification process is well documented for fluorescent tagging. In point-of-care testing applications, the sepsis diagnostics require fast monitoring, inexpensive testing, and reliable results at resource limited settings, i.e. battle field, home care for dialysis. However, the cell/E.coli are hard to directly capture and see at the POCT because of the small size, 2 μm long and 0.5 μm in diameter, and the bacteria are rare in the blood stream in sepsis. Here, we propose a novel POCT platform to image and enumerate cell/E.coli on a microfluidic surface to diagnose sepsis at resource limited conditions. We demonstrate that target cells are captured from 5 μl of whole blood using specific antibodies and E.coli are imaged using a lens-free imaging platform, 2.2 μm pixel CMOS based imaging sensor. This POCT cell/bacteria capture and enumeration approach can further be used for medical diagnostics of sepsis. We also show approaches to rapidly quantify white blood cell counts from blood which can be used to monitor immune response.

  8. Tomographic scanning apparatus

    International Nuclear Information System (INIS)

    1981-01-01

    Details are presented of a tomographic scanning apparatus, its rotational assembly, and the control and circuit elements, with particular reference to the amplifier and multiplexing circuits enabling detector signal calibration. (U.K.)

  9. Tomographic scanning apparatus

    International Nuclear Information System (INIS)

    1981-01-01

    Details are given of a tomographic scanning apparatus, with particular reference to a multiplexer slip ring means for receiving output from the detectors and enabling interfeed to the image reconstruction station. (U.K.)

  10. Tomographic scanning apparatus

    International Nuclear Information System (INIS)

    1981-01-01

    This patent specification relates to a tomographic scanning apparatus using a fan beam and digital output signal, and particularly to the design of the gas-pressurized ionization detection system. (U.K.)

  11. Tomographic method and apparatus

    International Nuclear Information System (INIS)

    Moore, R.M.

    1981-01-01

    A tomographic x-ray machine has a camera and film-plane section which move about a primary axis for imaging a selected cross-section of an anatomical member onto the film. A ''scout image'' of the member is taken at right angles to the plane of the desired cross-section to indicate the cross-section's angle with respect to the primary axis. The film plane is then located at the same angle with respect to a film cassette axis as the selected cross-section makes with the primary axis. The film plane and the cross-section are then maintained in parallel planes throughout motion of the camera and film plane during tomographic radiography. (author)

  12. Axial tomographic scanner

    International Nuclear Information System (INIS)

    1976-01-01

    An axial tomographic system is described comprising axial tomographic means for collecting sets of data corresponding to the transmission or absorption of a number of beams of penetrating radiation through a planar slice of an object. It includes means to locate an object to be analyzed, a source and detector for directing one or more beams of penetrating radiation through the object from the source to the detector, and means to rotate (and optionally translate) the source as well as means to process the collected sets of data. Data collection, data processing, and data display can each be conducted independently of each other. An additional advantage of the system described is that the raw data (i.e., the originally collected data) are not destroyed by the data processing but instead are retained intact for further reference or use, if needed

  13. Industrial dynamic tomographic reconstruction

    International Nuclear Information System (INIS)

    Oliveira, Eric Ferreira de

    2016-01-01

    The state of the art methods applied to industrial processes is currently based on the principles of classical tomographic reconstructions developed for tomographic patterns of static distributions, or is limited to cases of low variability of the density distribution function of the tomographed object. Noise and motion artifacts are the main problems caused by a mismatch in the data from views acquired in different instants. All of these add to the known fact that using a limited amount of data can result in the presence of noise, artifacts and some inconsistencies with the distribution under study. One of the objectives of the present work is to discuss the difficulties that arise from implementing reconstruction algorithms in dynamic tomography that were originally developed for static distributions. Another objective is to propose solutions that aim at reducing a temporal type of information loss caused by employing regular acquisition systems to dynamic processes. With respect to dynamic image reconstruction it was conducted a comparison between different static reconstruction methods, like MART and FBP, when used for dynamic scenarios. This comparison was based on a MCNPx simulation as well as an analytical setup of an aluminum cylinder that moves along the section of a riser during the process of acquisition, and also based on cross section images from CFD techniques. As for the adaptation of current tomographic acquisition systems for dynamic processes, this work established a sequence of tomographic views in a just-in-time fashion for visualization purposes, a form of visually disposing density information as soon as it becomes amenable to image reconstruction. A third contribution was to take advantage of the triple color channel necessary to display colored images in most displays, so that, by appropriately scaling the acquired values of each view in the linear system of the reconstruction, it was possible to imprint a temporal trace into the regularly

  14. Correlation Reconstruction Tomographic PIV

    Science.gov (United States)

    La Foy, Roderick; Vlachos, Pavlos

    2017-11-01

    A new volumetric Particle Image Velocimetry technique was developed that outputs accurate velocity measurements up to very high seeding densities while requiring lower computational expenditure. This technique combines the tomographic and cross-correlation steps by directly reconstructing the 3D cross-correlation volumes. Since many particles contribute to a single correlation peak, this decreases the noise contributions from ghost reconstructions, allowing accurate velocity measurements to be made at exceptionally high seeding densities. Additionally the overall computational cost is lowered by combining the reconstruction and cross-correlation steps. Results comparing the errors of the new technique applied to both simulated and experimental data will be presented.

  15. Tomographic scanning apparatus

    International Nuclear Information System (INIS)

    Abele, M.

    1983-01-01

    A computerized tomographic scanning apparatus suitable for diagnosis and for improving target identification in stereotactic neurosurgery is described. It consists of a base, a source of penetrating energy, a detector which produces scanning signals and detector positioning means. A frame with top and bottom arms secures the detector and source to the top and bottom arms respectively. A drive mechanism rotates the frame about an axis along which the frame may also be moved. Finally, the detector may be moved relative to the bottom arm in a direction contrary to the rotation of the frame. (U.K.)

  16. A Field-Portable Cell Analyzer without a Microscope and Reagents.

    Science.gov (United States)

    Seo, Dongmin; Oh, Sangwoo; Lee, Moonjin; Hwang, Yongha; Seo, Sungkyu

    2017-12-29

    This paper demonstrates a commercial-level field-portable lens-free cell analyzer called the NaviCell (No-stain and Automated Versatile Innovative cell analyzer) capable of automatically analyzing cell count and viability without employing an optical microscope and reagents. Based on the lens-free shadow imaging technique, the NaviCell (162 × 135 × 138 mm³ and 1.02 kg) has the advantage of providing analysis results with improved standard deviation between measurement results, owing to its large field of view. Importantly, the cell counting and viability testing can be analyzed without the use of any reagent, thereby simplifying the measurement procedure and reducing potential errors during sample preparation. In this study, the performance of the NaviCell for cell counting and viability testing was demonstrated using 13 and six cell lines, respectively. Based on the results of the hemocytometer ( de facto standard), the error rate (ER) and coefficient of variation (CV) of the NaviCell are approximately 3.27 and 2.16 times better than the commercial cell counter, respectively. The cell viability testing of the NaviCell also showed an ER and CV performance improvement of 5.09 and 1.8 times, respectively, demonstrating sufficient potential in the field of cell analysis.

  17. Tomographic reconstruction of quantum metrics

    Science.gov (United States)

    Laudato, Marco; Marmo, Giuseppe; Mele, Fabio M.; Ventriglia, Franco; Vitale, Patrizia

    2018-02-01

    In the framework of quantum information geometry we investigate the relationship between monotone metric tensors uniquely defined on the space of quantum tomograms, once the tomographic scheme is chosen, and monotone quantum metrics on the space of quantum states, classified by operator monotone functions, according to the Petz classification theorem. We show that different metrics can be related through a change in the tomographic map and prove that there exists a bijective relation between monotone quantum metrics associated with different operator monotone functions. Such a bijective relation is uniquely defined in terms of solutions of a first order second degree differential equation for the parameters of the involved tomographic maps. We first exhibit an example of a non-linear tomographic map that connects a monotone metric with a new one, which is not monotone. Then we provide a second example where two monotone metrics are uniquely related through their tomographic parameters.

  18. Computerized tomographic system

    International Nuclear Information System (INIS)

    Godbarsen, R.; Barrett, D.M.; Garrott, P.M.; Foley, L.E.; Redington, R.W.; Lambert, T.W.; Edelheit, L.S.

    1981-01-01

    A computerized tomographic system for examining human breasts is described in detail. Conventional X-ray scanning apparatus has difficulty in achieving the levels of image definition and examination speeds required for mass screening. A novel method of scanning successive layers of the breast with a rotating X-ray beam is discussed and details of the control circuitry and sequence steps are given. The method involves immersing the breast in an inner fluid (e.g. water) filled container which is stationary during an examination and is surrounded by a large outer container which is also filled with the fluid; the inner and outer containers are always maintained at a constant height and the X-ray absorption across the fan-shaped beam is as close as possible to constant. (U.K.)

  19. Tomographic examination table

    International Nuclear Information System (INIS)

    Redington, R.W.; Henkes, J.L.

    1979-01-01

    Equipment is described for positioning and supporting patients during tomographic mammography using X-rays. The equipment consists of a table and fabric slings which permit the examination of a downward, pendant breast of a prone patient by allowing the breast to pass through a aperture in the table into a fluid filled container. The fluid has an X-ray absorption coefficient similar to that of soft human tissue allowing high density resolution radiography and permitting accurate detection of breast tumours. The shape of the equipment and the positioning of the patient allow the detector and X-ray source to rotate 360 0 about a vertical axis through the breast. This permits the use of relatively simple image reconstruction algorithms and a divergent X-ray geometry. (UK)

  20. Microscope basics.

    Science.gov (United States)

    Sluder, Greenfield; Nordberg, Joshua J

    2013-01-01

    This chapter provides information on how microscopes work and discusses some of the microscope issues to be considered in using a video camera on the microscope. There are two types of microscopes in use today for research in cell biology-the older finite tube-length (typically 160mm mechanical tube length) microscopes and the infinity optics microscopes that are now produced. The objective lens forms a magnified, real image of the specimen at a specific distance from the objective known as the intermediate image plane. All objectives are designed to be used with the specimen at a defined distance from the front lens element of the objective (the working distance) so that the image formed is located at a specific location in the microscope. Infinity optics microscopes differ from the finite tube-length microscopes in that the objectives are designed to project the image of the specimen to infinity and do not, on their own, form a real image of the specimen. Three types of objectives are in common use today-plan achromats, plan apochromats, and plan fluorite lenses. The concept of mounting video cameras on the microscope is also presented in the chapter. Copyright © 2003 Elsevier Inc. All rights reserved.

  1. Tomographic multiphase flow measurement

    International Nuclear Information System (INIS)

    Sætre, C.; Johansen, G.A.; Tjugum, S.A.

    2012-01-01

    Measurement of multiphase flow of gas, oil and water is not at all trivial and in spite of considerable achievements over the past two decades, important challenges remain (). These are related to reducing measurement uncertainties arising from variations in the flow regime, improving long term stability and developing new means for calibration, adjustment and verification of the multiphase flow meters. This work focuses on the first two issues using multi gamma beam (MGB) measurements for identification of the type of flow regime. Further gamma ray tomographic measurements are used for reference of the gas/liquid distribution. For the MGB method one Am-241 source with principal emission at 59.5 keV is used because this relatively low energy enables efficient collimation and thereby shaping of the beams, as well as compact detectors. One detector is placed diametrically opposite the source whereas the second is positioned to the side so that this beam is close to the pipe wall. The principle is then straight forward to compare the measured intensities of these detectors and through that identify the flow pattern, i.e. the instantaneous cross-sectional gas-liquid distribution. The measurement setup also includes Compton scattering measurements, which can provide information about the changes in the water salinity for flow segments with high water liquid ratio and low gas fractions. By measuring the transmitted intensity in short time slots (<100ms), rapid regime variations are revealed. From this we can select the time sections suitable for salinity measurements. Since the salinity variations change at the time scale of hours, a running average can be performed to increase the accuracy of the measurements. Recent results of this work will be presented here. - Highlights: ► Multiphase flow gas-fraction and flow regime measurements by multi gamma ray beams. ► High-speed gamma ray tomograph as reference for the flow pattern and gas fraction. ► Dual modality

  2. Gynecologic electrical impedance tomograph

    Science.gov (United States)

    Korjenevsky, A.; Cherepenin, V.; Trokhanova, O.; Tuykin, T.

    2010-04-01

    Electrical impedance tomography extends to the new and new areas of the medical diagnostics: lungs, breast, prostate, etc. The feedback from the doctors who use our breast EIT diagnostic system has induced us to develop the 3D electrical impedance imaging device for diagnostics of the cervix of the uterus - gynecologic impedance tomograph (GIT). The device uses the same measuring approach as the breast imaging system: 2D flat array of the electrodes arranged on the probe with handle is placed against the body. Each of the 32 electrodes of the array is connected in turn to the current source while the rest electrodes acquire the potentials on the surface. The current flows through the electrode of the array and returns through the remote electrode placed on the patient's limb. The voltages are measured relative to another remote electrode. The 3D backprojection along equipotential surfaces is used to reconstruct conductivity distribution up to approximately 1 cm in depth. Small number of electrodes enables us to implement real time imaging with a few frames per sec. rate. The device is under initial testing and evaluation of the imaging capabilities and suitability of usage.

  3. Microwave Microscope

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Makes ultra-high-resolution field measurements. The Microwave Microscope (MWM) has been used in support of several NRL experimental programs involving sea...

  4. Tomographic imaging system

    International Nuclear Information System (INIS)

    Hayakawa, T.; Horiba, I.; Kohno, H.; Nakaya, C.; Sekihara, K.; Shiono, H.; Tomura, T.; Yamamoto, S.; Yanaka, S.

    1980-01-01

    A tomographic imaging system comprising: irradiating means for irradating a cross-section of an object under consideration with radiation rays from plural directions; detector means for detecting the radiation rays transmitted through the cross-section of said object to produce an output signal; first memory means for storing the output signal of said detector means; and an image jreconstructing section for performing a convolution integral operation on the contents of said first memory means by means of a first weighting function to reconstruct a three-dimensional image of the cross-section of said object, said image reconstructing section including (I) second memory means for storing a second weighting function, said second weighting function being provided with a predetermined positive and negative (N-1)th order when the output signal of said detector means produced by the irradiation of the cross-section of said object from one of said plural directions is sampled by N points, the value of the (N-1)th order of said second weighting function being an integration of said first weighting function from the (N-1)th order to positive infinity and the value of -(N-1)th order of said second weighting function being an integration of said first weighting function from the -(N-1)th order to negative infinity, (II) control means for successively reading out the contents of said first and second memory means, and (III) operational means for performing multiplying and summing operations on the read-out contents of said first and second memory means, said operational means producing the product of the values fo the (N-1)th and -(N-1)th orders of said second weighting function and a component of the output signal of said detector means relating to the radiation rays free from the absorption thereof by said object

  5. Computer tomographic diagnosis of echinococcosis

    Energy Technology Data Exchange (ETDEWEB)

    Haertel, M.; Fretz, C.; Fuchs, W.A.

    1980-08-01

    The computer tomographic appearances and differential diagnosis in 22 patients with echinococcosis are described; of these, twelve were of the cystic and ten of the alveolar type. The computer tomographic appearances are characterised by the presence of daughter cysts (66%) within the sharply demarkated parasitic cyst of water density. In the absence of daughter cysts, a definite aetiological diagnosis cannot be made, although there is a tendency to clasification of the occassionally multiple echinococcus cysts. The computer tomographic appearances of advanced alveolar echinococcosis are characterised by partial collequative necrosis, with clacification around the necrotic areas (90%). The absence of CT evidence of partial necrosis and calsification of the pseudotumour makes it difficult to establish a specific diagnosis. The conclusive and non-invasive character of the procedure and its reproducibility makes computer tomography the method of choice for the diagnosis and follow-up of echinococcosis.

  6. X-Ray Tomographic Reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Bonnie Schmittberger

    2010-08-25

    Tomographic scans have revolutionized imaging techniques used in medical and biological research by resolving individual sample slices instead of several superimposed images that are obtained from regular x-ray scans. X-Ray fluorescence computed tomography, a more specific tomography technique, bombards the sample with synchrotron x-rays and detects the fluorescent photons emitted from the sample. However, since x-rays are attenuated as they pass through the sample, tomographic scans often produce images with erroneous low densities in areas where the x-rays have already passed through most of the sample. To correct for this and correctly reconstruct the data in order to obtain the most accurate images, a program employing iterative methods based on the inverse Radon transform was written. Applying this reconstruction method to a tomographic image recovered some of the lost densities, providing a more accurate image from which element concentrations and internal structure can be determined.

  7. Original circuitry for TOHR tomograph

    International Nuclear Information System (INIS)

    Cuzon, J.C.; Pinot, L.

    1999-01-01

    Having industrialization in mind, a specific electronics for a high resolution tomograph is designed out of the usual standards of nuclear physics. All the information are converted in the time domain and a fast processor, in front of the data acquisition, carries out the time and energy coincidences. (authors)

  8. Microscopic colitis

    DEFF Research Database (Denmark)

    Münch, A; Aust, D; Bohr, Jakob

    2012-01-01

    Microscopic colitis (MC) is an inflammatory bowel disease presenting with chronic, non-bloody watery diarrhoea and few or no endoscopic abnormalities. The histological examination reveals mainly two subtypes of MC, lymphocytic or collagenous colitis. Despite the fact that the incidence in MC has...... been rising over the last decades, research has been sparse and our knowledge about MC remains limited. Specialists in the field have initiated the European Microscopic Colitis Group (EMCG) with the primary goal to create awareness on MC. The EMCG is furthermore a forum with the intention to promote...

  9. Martian Microscope

    Science.gov (United States)

    2004-01-01

    The microscopic imager (circular device in center) is in clear view above the surface at Meridiani Planum, Mars, in this approximate true-color image taken by the panoramic camera on the Mars Exploration Rover Opportunity. The image was taken on the 9th sol of the rover's journey. The microscopic imager is located on the rover's instrument deployment device, or arm. The arrow is pointing to the lens of the instrument. Note the dust cover, which flips out to the left of the lens, is open. This approximated color image was created using the camera's violet and infrared filters as blue and red.

  10. Computer tomographic findings in neurosyphilis

    Directory of Open Access Journals (Sweden)

    Pavithran K

    1993-01-01

    Full Text Available Computer tomographic features of the brain in 2 cases of neurosyphilis are described. Less prominence of the cortical sulci suggesting cortical atrophy was the predominant feature in a case of general paralysis of insane. Diffuse, irregular, non-enhancing, low-attenuated area in the cortical and subcortical region of the right temporoparietal lobe of a patient with vascular syphilis, suggested infarction of the brain.

  11. Tomographic PIV: principles and practice

    International Nuclear Information System (INIS)

    Scarano, F

    2013-01-01

    A survey is given of the major developments in three-dimensional velocity field measurements using the tomographic particle image velocimetry (PIV) technique. The appearance of tomo-PIV dates back seven years from the present review (Elsinga et al 2005a 6th Int. Symp. PIV (Pasadena, CA)) and this approach has rapidly spread as a versatile, robust and accurate technique to investigate three-dimensional flows (Arroyo and Hinsch 2008 Topics in Applied Physics vol 112 ed A Schröder and C E Willert (Berlin: Springer) pp 127–54) and turbulence physics in particular. A considerable number of applications have been achieved over a wide range of flow problems, which requires the current status and capabilities of tomographic PIV to be reviewed. The fundamental aspects of the technique are discussed beginning from hardware considerations for volume illumination, imaging systems, their configurations and system calibration. The data processing aspects are of uppermost importance: image pre-processing, 3D object reconstruction and particle motion analysis are presented with their fundamental aspects along with the most advanced approaches. Reconstruction and cross-correlation algorithms, attaining higher measurement precision, spatial resolution or higher computational efficiency, are also discussed. The exploitation of 3D and time-resolved (4D) tomographic PIV data includes the evaluation of flow field pressure on the basis of the flow governing equation. The discussion also covers a-posteriori error analysis techniques. The most relevant applications of tomo-PIV in fluid mechanics are surveyed, covering experiments in air and water flows. In measurements in flow regimes from low-speed to supersonic, most emphasis is given to the complex 3D organization of turbulent coherent structures. (topical review)

  12. Computer tomographic examinations in epilepsy

    International Nuclear Information System (INIS)

    De Villiers, J.F.K.

    1984-01-01

    Epileptic patients that was examined at the Universitas Hospital (Bloemfontein) by means of computerized tomography for the period July 1978 - December 1980, are divided into two groups: a) Patients with general epilepsy of convulsions - 507; b) Patients with vocal or partial epilepsy - 111. The method of examination and the results for both general and vocal epilepsy are discussed. A degenerative state was found in 35% of the positive computer tomographic examinations in general epilepsy and 22% of the positive examinations for vocal epilepsy. The purpose of the article was to explain the circumstances that can be expected when a epileptic patient is examined by means of computerized tomography

  13. Tomographic anthropomorphic models. Pt. 1

    International Nuclear Information System (INIS)

    Veit, R.; Zankl, M.; Petoussi, N.; Mannweiler, E.; Drexler, G.; Williams, G.

    1989-01-01

    The first generation of heterogenoeous anthropomorphic mathematical models to be used in dose calculations was the MIRD-5 adult phantom, followed by the pediatric MIRD-type phantoms and by the GSF sex-specific phantoms ADAM and EVA. A new generation of realistic anthropomorphic models is now introduced. The organs and tissues of these models consist of a well defined number of volume elements (voxels), derived from computer tomographic (CT) data; consequently, these models were named voxel or tomographic models. So far two voxel models of real patients are available: one of an 8 week old baby and of a 7 year old child. For simplicity, the model of the baby will be referred to as BABY and that of the child as CHILD. In chapter 1 a brief literature review is given on the existing mathematical models and their applications. The reasons that lead to the construction of the new CT models is discussed. In chapter 2 the technique is described which allows to convert any physical object into computer files to be used for dose calculations. The technique which produces three dimensional reconstructions of high resolution is discussed. In chapter 3 the main characteristics of the models of the baby and child are given. Tables of organ masses and volumes are presented together with three dimensional images of some organs and tissues. A special mention is given to the assessment of bone marrow distribution. Chapter 4 gives a short description of the Monte Carlo code used in conjunction with the models to calculate organ and tissue doses resulting from photon exposures. Some technical details concerning the computer files which describe the models are also given. (orig./HP)

  14. High resolution tomographic instrument development

    International Nuclear Information System (INIS)

    1992-01-01

    Our recent work has concentrated on the development of high-resolution PET instrumentation reflecting in part the growing importance of PET in nuclear medicine imaging. We have developed a number of positron imaging instruments and have the distinction that every instrument has been placed in operation and has had an extensive history of application for basic research and clinical study. The present program is a logical continuation of these earlier successes. PCR-I, a single ring positron tomograph was the first demonstration of analog coding using BGO. It employed 4 mm detectors and is currently being used for a wide range of biological studies. These are of immense importance in guiding the direction for future instruments. In particular, PCR-II, a volume sensitive positron tomograph with 3 mm spatial resolution has benefited greatly from the studies using PCR-I. PCR-II is currently in the final stages of assembly and testing and will shortly be placed in operation for imaging phantoms, animals and ultimately humans. Perhaps the most important finding resulting from our previous study is that resolution and sensitivity must be carefully balanced to achieve a practical high resolution system. PCR-II has been designed to have the detection characteristics required to achieve 3 mm resolution in human brain under practical imaging situations. The development of algorithms by the group headed by Dr. Chesler is based on a long history of prior study including his joint work with Drs. Pelc and Reiderer and Stearns. This body of expertise will be applied to the processing of data from PCR-II when it becomes operational

  15. High resolution tomographic instrument development

    Energy Technology Data Exchange (ETDEWEB)

    1992-01-01

    Our recent work has concentrated on the development of high-resolution PET instrumentation reflecting in part the growing importance of PET in nuclear medicine imaging. We have developed a number of positron imaging instruments and have the distinction that every instrument has been placed in operation and has had an extensive history of application for basic research and clinical study. The present program is a logical continuation of these earlier successes. PCR-I, a single ring positron tomograph was the first demonstration of analog coding using BGO. It employed 4 mm detectors and is currently being used for a wide range of biological studies. These are of immense importance in guiding the direction for future instruments. In particular, PCR-II, a volume sensitive positron tomograph with 3 mm spatial resolution has benefited greatly from the studies using PCR-I. PCR-II is currently in the final stages of assembly and testing and will shortly be placed in operation for imaging phantoms, animals and ultimately humans. Perhaps the most important finding resulting from our previous study is that resolution and sensitivity must be carefully balanced to achieve a practical high resolution system. PCR-II has been designed to have the detection characteristics required to achieve 3 mm resolution in human brain under practical imaging situations. The development of algorithms by the group headed by Dr. Chesler is based on a long history of prior study including his joint work with Drs. Pelc and Reiderer and Stearns. This body of expertise will be applied to the processing of data from PCR-II when it becomes operational.

  16. High resolution tomographic instrument development

    Energy Technology Data Exchange (ETDEWEB)

    1992-08-01

    Our recent work has concentrated on the development of high-resolution PET instrumentation reflecting in part the growing importance of PET in nuclear medicine imaging. We have developed a number of positron imaging instruments and have the distinction that every instrument has been placed in operation and has had an extensive history of application for basic research and clinical study. The present program is a logical continuation of these earlier successes. PCR-I, a single ring positron tomograph was the first demonstration of analog coding using BGO. It employed 4 mm detectors and is currently being used for a wide range of biological studies. These are of immense importance in guiding the direction for future instruments. In particular, PCR-II, a volume sensitive positron tomograph with 3 mm spatial resolution has benefited greatly from the studies using PCR-I. PCR-II is currently in the final stages of assembly and testing and will shortly be placed in operation for imaging phantoms, animals and ultimately humans. Perhaps the most important finding resulting from our previous study is that resolution and sensitivity must be carefully balanced to achieve a practical high resolution system. PCR-II has been designed to have the detection characteristics required to achieve 3 mm resolution in human brain under practical imaging situations. The development of algorithms by the group headed by Dr. Chesler is based on a long history of prior study including his joint work with Drs. Pelc and Reiderer and Stearns. This body of expertise will be applied to the processing of data from PCR-II when it becomes operational.

  17. Compact Positron Tomograph for Prostate Imaging

    National Research Council Canada - National Science Library

    Huber, Jennifer S

    2005-01-01

    The goal of this project is to construct a functioning compact positron tomograph, whose geometry is optimized for detecting prostate tumors with molecular tracers such as 11Ccholine (carbon-11 choline...

  18. Compact Positron Tomograph for Prostate Imaging

    National Research Council Canada - National Science Library

    Huber, Jennifer

    2004-01-01

    The goal of this project is to construct a functioning compact positron tomograph, whose geometry is optimized for detecting prostate tumors with molecular tracers such as 11Ccholine (carbon-11 choline...

  19. Computed Tomographic Evaluation of Mandibular Ameloblastoma

    Directory of Open Access Journals (Sweden)

    N Eswar

    2003-01-01

    Five interesting cases of mandibular ameloblastoma are presented here, each case showing different histological pattern and corresponding computer tomographic appearance. Also an attempt is made to establish CT pattern in these histological varieties of ameloblastoma.

  20. Computed tomographic findings of intracranial gliosis

    Energy Technology Data Exchange (ETDEWEB)

    Weisberg, L.

    1981-08-01

    The clinical and computed tomographic (CT) findings in eight patients with pathological evidence of cerebral gliosis are analyzed. CT findings do not permit differentiation of gliosis from other neoplastic and non-neoplastic conditions.

  1. Computer tomographic findings of intracranial gliosis.

    Science.gov (United States)

    Weisberg, L

    1981-01-01

    The clinical and computer tomographic (CT) findings in eight patients with pathological evidence of cerebral gliosis and analyzed. CT findings do not permit differentiation of gliosis from other neoplastic and non-neoplastic conditions.

  2. Tomographic PIV: particles versus blobs

    International Nuclear Information System (INIS)

    Champagnat, Frédéric; Cornic, Philippe; Besnerais, Guy Le; Plyer, Aurélien; Cheminet, Adam; Leclaire, Benjamin

    2014-01-01

    We present an alternative approach to tomographic particle image velocimetry (tomo-PIV) that seeks to recover nearly single voxel particles rather than blobs of extended size. The baseline of our approach is a particle-based representation of image data. An appropriate discretization of this representation yields an original linear forward model with a weight matrix built with specific samples of the system’s point spread function (PSF). Such an approach requires only a few voxels to explain the image appearance, therefore it favors much more sparsely reconstructed volumes than classic tomo-PIV. The proposed forward model is general and flexible and can be embedded in a classical multiplicative algebraic reconstruction technique (MART) or a simultaneous multiplicative algebraic reconstruction technique (SMART) inversion procedure. We show, using synthetic PIV images and by way of a large exploration of the generating conditions and a variety of performance metrics, that the model leads to better results than the classical tomo-PIV approach, in particular in the case of seeding densities greater than 0.06 particles per pixel and of PSFs characterized by a standard deviation larger than 0.8 pixels. (paper)

  3. Emerging tomographic methods within the petroleum industry

    International Nuclear Information System (INIS)

    Johansen, Geir Anton

    2013-01-01

    Since industrial process tomography was introduced as a concept almost two decades ago, the considerable progress within a large variety of sensing modalities has to a large extent been technology driven. Industrial tomography applications may be divided into three categories: 1) Laboratory systems, 2) Field equipment for diagnostics and mapping purposes, and 3) Permanently installed systems. Examples on emerging methods on all categories will be presented, either from R and D at the University of Bergen and/or our industrial partners. Most developments are within the first category, where tomographs are used to provide better understanding of various processes such as pipe flow, separators, mixers and reactors. Here tomographic data is most often used to provide better process knowledge, for reference measurements and validation and development of process models, and finally for development for instruments and process equipment. The requirement here may be either high spatial resolution or high temporal resolution, or combinations of these. Tomographic field measurements are applied to either to inspect processes or equipment on a regular base or at faulty or irregular operation, or to map multicomponent systems such petroleum reservoirs, their structure and the distribution gas, oil and water within them. The latter will only be briefly touched upon here. Tomographic methods are increasingly being used for process and equipment diagnostics. The requirements vary and solutions based on repetition of single measurements, such as in column scanning, to full tomographic systems where there is sufficiently space or access. The third category is tomographic instruments that are permanently installed in situ in a process. These need not provide full tomographic images and instruments with fewer views are often preferred to reduce complexity and increase the instrument reliability. (author)

  4. Emerging tomographic methods within the petroleum industry

    Energy Technology Data Exchange (ETDEWEB)

    Johansen, Geir Anton, E-mail: geir.johansen@ift.uib.no [University of Bergen (UiB), Bergen, (Norway)

    2013-07-01

    Since industrial process tomography was introduced as a concept almost two decades ago, the considerable progress within a large variety of sensing modalities has to a large extent been technology driven. Industrial tomography applications may be divided into three categories: 1) Laboratory systems, 2) Field equipment for diagnostics and mapping purposes, and 3) Permanently installed systems. Examples on emerging methods on all categories will be presented, either from R and D at the University of Bergen and/or our industrial partners. Most developments are within the first category, where tomographs are used to provide better understanding of various processes such as pipe flow, separators, mixers and reactors. Here tomographic data is most often used to provide better process knowledge, for reference measurements and validation and development of process models, and finally for development for instruments and process equipment. The requirement here may be either high spatial resolution or high temporal resolution, or combinations of these. Tomographic field measurements are applied to either to inspect processes or equipment on a regular base or at faulty or irregular operation, or to map multicomponent systems such petroleum reservoirs, their structure and the distribution gas, oil and water within them. The latter will only be briefly touched upon here. Tomographic methods are increasingly being used for process and equipment diagnostics. The requirements vary and solutions based on repetition of single measurements, such as in column scanning, to full tomographic systems where there is sufficiently space or access. The third category is tomographic instruments that are permanently installed in situ in a process. These need not provide full tomographic images and instruments with fewer views are often preferred to reduce complexity and increase the instrument reliability. (author)

  5. Transmission positron microscopes

    International Nuclear Information System (INIS)

    Doyama, Masao; Kogure, Yoshiaki; Inoue, Miyoshi; Kurihara, Toshikazu; Yoshiie, Toshimasa; Oshima, Ryuichiro; Matsuya, Miyuki

    2006-01-01

    Immediate and near-future plans for transmission positron microscopes being built at KEK, Tsukuba, Japan, are described. The characteristic feature of this project is remolding a commercial electron microscope to a positron microscope. A point source of electrons kept at a negative high voltage is changed to a point source of positrons kept at a high positive voltage. Positional resolution of transmission microscopes should be theoretically the same as electron microscopes. Positron microscopes utilizing trapping of positrons have always positional ambiguity due to the diffusion of positrons

  6. Connections model for tomographic images reconstruction

    International Nuclear Information System (INIS)

    Rodrigues, R.G.S.; Pela, C.A.; Roque, S.F. A.C.

    1998-01-01

    This paper shows an artificial neural network with an adequately topology for tomographic image reconstruction. The associated error function is derived and the learning algorithm is make. The simulated results are presented and demonstrate the existence of a generalized solution for nets with linear activation function. (Author)

  7. Tomographic image reconstruction from continuous projections

    NARCIS (Netherlands)

    J. Cant (Jeroen); W.J. Palenstijn (Willem Jan); G. Behiels; J. Sijbers (Jan)

    2014-01-01

    htmlabstractAn important design aspect in tomographic image reconstruction is the choice between a step-and-shoot protocol versus continuous X-ray tube movement for image acquisition. A step-and-shoot protocol implies a perfectly still tube during X-ray exposure, and hence involves moving the tube

  8. Case Report: Unusual computed tomographic features of ...

    African Journals Online (AJOL)

    A case report of a 57-year old woman who presented with signs and symptoms of intracranial mass. Computed tomographic (CT) and clinical features were unusual and suggestive of a parasaggital Meningioma. However an accurate diagnosis of a tuberculoma was made at surgery and histopathological examination.

  9. A NMR Tomographic System for image visualization

    International Nuclear Information System (INIS)

    Paiva, M.S.V. de; Slaets, J.F.W.; Almeida, L.O.B. de

    1989-01-01

    This paper presents some characteristics of a graphics system that is being constructed in the Electronics Instrumentation and Computation Laboratory (LIE) of IFQSC. This system will be used in reconstruction and interpretation of MR tomographic images. A minimum system is at moment being used at our laboratory to visualize MR images. (author) [pt

  10. Quantum probability measures and tomographic probability densities

    NARCIS (Netherlands)

    Amosov, GG; Man'ko, [No Value

    2004-01-01

    Using a simple relation of the Dirac delta-function to generalized the theta-function, the relationship between the tomographic probability approach and the quantum probability measure approach with the description of quantum states is discussed. The quantum state tomogram expressed in terms of the

  11. A new ionospheric tomographic algorithm – constrained ...

    Indian Academy of Sciences (India)

    the above algorithms. Finally, the new method is applied to reconstruct the IED distributions using the regional GNSS observation (i.e., GPS) over. China. 2. Tomographic formulation. As is well known, one measurable parameter of the ionosphere is the total electron content (TEC), which is the line integral of IED along ray ...

  12. The bar coil for NMR tomograph

    International Nuclear Information System (INIS)

    Bogorodzki, P.; Piatkowski, A.; Wasielewski, J.

    1995-01-01

    The bar coil (bi-planar) for the NMR tomograph, designed for medical diagnostics, has been described. The tests of coil shown that it generates good homogenous magnetic field in a big volume what results in improving of the signal-to-noise ratio

  13. Decomposition of time-resolved tomographic PIV

    NARCIS (Netherlands)

    Schmid, P.J.; Violato, D.; Scarano, F.

    2012-01-01

    An experimental study has been conducted on a transitional water jet at a Reynolds number of Re = 5,000. Flow fields have been obtained by means of time-resolved tomographic particle image velocimetry capturing all relevant spatial and temporal scales. The measured threedimensional flow fields have

  14. The Scanning Optical Microscope.

    Science.gov (United States)

    Sheppard, C. J. R.

    1978-01-01

    Describes the principle of the scanning optical microscope and explains its advantages over the conventional microscope in the improvement of resolution and contrast, as well as the possibility of producing a picture from optical harmonies generated within the specimen.

  15. A new apparatus for electron tomography in the scanning electron microscope

    Energy Technology Data Exchange (ETDEWEB)

    Morandi, V., E-mail: morandi@bo.imm.cnr.it; Maccagnani, P.; Masini, L.; Migliori, A.; Ortolani, L.; Pezza, A. [CNR-IMM Sezione di Bologna, via Gobetti 101, 40129 Bologna (Italy); Del Marro, M.; Pallocca, G.; Vinciguerra, P. [ASSING S.P.A., via E. Amaldi 14, 00016 Monterotondo (Rome) (Italy); Rossi, M.; Ferroni, M. [Dip.to di Scienze di Base e Applicate per l’Ingegneria and Centro di Ricerca per le Nanotecnologie Applicate all’Ingegneria (CNIS), Università degli Studi di Roma “Sapienza”, Via A. Scarpa, 00161 Rome (Italy); Sberveglieri, G. [SENSOR Lab, Dip.to di Ingegneria dell’Informazione, Università degli Studi di Brescia and CNR-INO, Via Valotti 9, 25123 Brescia (Italy); Vittori-Antisari, M. [Unità Tecnica Tecnologie dei Materiali, ENEA Centro Ricerche Casaccia, Via Anguillarese 301, 00123 S. Maria di Galeria (Rome) (Italy)

    2015-06-23

    The three-dimensional reconstruction of a microscopic specimen has been obtained by applying the tomographic algorithm to a set of images acquired in a Scanning Electron Microscope. This result was achieved starting from a series of projections obtained by stepwise rotating the sample under the beam raster. The Scanning Electron Microscope was operated in the scanning-transmission imaging mode, where the intensity of the transmitted electron beam is a monotonic function of the local mass-density and thickness of the specimen. The detection strategy has been implemented and tailored in order to maintain the projection requirement over the large tilt range, as required by the tomographic workflow. A Si-based electron detector and an eucentric-rotation specimen holder have been specifically developed for the purpose.

  16. Present state and development of positron tomographs

    International Nuclear Information System (INIS)

    Allemand, R.; Gariod, R.; Laval, M.; Tournier, F.

    1979-01-01

    This document presents the main characteristics of positron tomographs and analyses the relative importance of the parameters to be taken into consideration in the design of a tomograph: on the one hand, the physical parameters linked to the measurement of the annihilation photons by time coincidence and, on the other, the geometrical and technological parameters of prime importance in minimizing the many spurious effects. The last part endeavours to show this sort of instrumentation has evolved. Using the results obtained in our laboratory by mathematical simulation, the expected advantages are presented on the picture quality of the time of flight measurement of annihilation photons. Where the physical aspects of this method are concerned, the advantage of using cesium fluoride as scintillator is demonstrated [fr

  17. Tomographic Techniques for Radar Ice Sounding

    DEFF Research Database (Denmark)

    Nielsen, Ulrik

    challenge. This dissertation deals with tomographic techniques based on multiphase-center radars that represent state-of-the-art technology within thefield of ice sounding. The use of advanced tomographic processing forclutter suppression is investigated, which up to this point has beenlargely unexplored...... in the literature. The investigation also includes atheoretical study of beamforming and direction-of-arrival (DOA) estimationtechniques. In addition to the primary treatment of clutter suppression,additional novel applications of tomography are also explored. Based on an experimental multi-phase-center dataset...... discrimination of the desired bed return from strong surface clutter ispresented. The technique is applied to data from the channel of the challengingJakobshavn Glacier acquired with the Multi-channel CoherentiiiRadar Depth Sounder/Imager (MCoRDS/I), where it is shown how thetechnique can be used to close some...

  18. Addition of Tomographic Capabilities to NMIS

    CERN Document Server

    Mullens, J A

    2003-01-01

    This paper describes tomographic capabilities for the Nuclear Materials Identification System (NMIS). The tomographic capabilities add weapons component spatial and material properties information that result in a more detailed item signature (template) and provide more information for physical attributes analyses. The Nuclear Materials Identification System (NMIS) is used routinely to confirm the identity of HEU components in sealed containers. It does this through a radiation signature acquired by shining a sup 2 sup 5 sup 2 Cf source through the container and measuring the radiation at four detectors stacked vertically on the other side. This measurement gives a gamma and neutron radiation transmission profile of the weapons component, mixed with the radiation production due to the induced fissions in the fissile materials. This information is sufficient to match an ''unknown'' weapons component signature to a template signature from a reference item when measuring under controlled conditions. Tomography m...

  19. Addition of Tomographic Capabilities to NMIS

    Energy Technology Data Exchange (ETDEWEB)

    Mullens, J.A.

    2003-03-11

    This paper describes tomographic capabilities for the Nuclear Materials Identification System (NMIS). The tomographic capabilities add weapons component spatial and material properties information that result in a more detailed item signature (template) and provide more information for physical attributes analyses. The Nuclear Materials Identification System (NMIS) is used routinely to confirm the identity of HEU components in sealed containers. It does this through a radiation signature acquired by shining a {sup 252}Cf source through the container and measuring the radiation at four detectors stacked vertically on the other side. This measurement gives a gamma and neutron radiation transmission profile of the weapons component, mixed with the radiation production due to the induced fissions in the fissile materials. This information is sufficient to match an ''unknown'' weapons component signature to a template signature from a reference item when measuring under controlled conditions. Tomography measures the interior of an item by making transmission measurements from all angles around the item, whereas NMIS makes the measurements from a single angle. Figure 1 is a standard example of tomographic reconstruction, the Shepp-Logan human brain phantom. The measured quantity is attenuation so high values (white) are highly attenuating areas.

  20. First tomographic image of ionospheric outflows

    Science.gov (United States)

    Yizengaw, E.; Moldwin, M. B.; Dyson, P. L.; Fraser, B. J.; Morley, S.

    2006-10-01

    An image of the dayside low-energy ion outflow event that occurred on 16 December 2003 was constructed with ground- and space-based GPS (Global Positioning System) Total Electron Content (TEC) data and ion drift meter data from the DMSP (Defense Meteorological Satellite Program). A tomographic reconstruction technique has been applied to the GPS TEC data obtained from the GPS receiver on the Low Earth Orbit (LEO) satellite FedSat. The two dimensional tomographic image of the topside ionosphere and plasmasphere reveals a spectacular beam-like dayside ion outflow emanating from the cusp region. The transverse components of the magnetic field in FedSat's NewMag data show the presence of field aligned current (FAC) sheets, indicating the existence of low-energy electron precipitation in the cusp region. The DMSP ion drift data show upward ion drift velocities and upward fluxes of low-energy ions and electrons at the orbiting height of the DMSP spacecraft in the cusp region. This study presents the first tomographic image of the flux tube structure of ionospheric ion outflows from 0.13 Re up to 3.17 Re altitude.

  1. Tomographic extreme-ultraviolet spectrographs: TESS.

    Science.gov (United States)

    Cotton, D M; Stephan, A; Cook, T; Vickers, J; Taylor, V; Chakrabarti, S

    2000-08-01

    We describe the system of Tomographic Extreme Ultraviolet (EUV) SpectrographS (TESS) that are the primary instruments for the Tomographic Experiment using Radiative Recombinative Ionospheric EUV and Radio Sources (TERRIERS) satellite. The spectrographs were designed to make high-sensitivity {80 counts/s)/Rayleigh [one Rayleigh is equivalent to 10(6) photons/(4pi str cm(2)s)}, line-of-sight measurements of the oi 135.6- and 91.1-nm emissions suitable for tomographic inversion. The system consists of five spectrographs, four identical nightglow instruments (for redundancy and added sensitivity), and one instrument with a smaller aperture to reduce sensitivity and increase spectral resolution for daytime operation. Each instrument has a bandpass of 80-140 nm with approximately 2- and 1-nm resolution for the night and day instruments, respectively. They utilize microchannel-plate-based two-dimensional imaging detectors with wedge-and-strip anode readouts. The instruments were designed, fabricated, and calibrated at Boston University, and the TERRIERS satellite was launched on 18 May 1999 from Vandenberg Air Force Base, California.

  2. Cryogenic immersion microscope

    Science.gov (United States)

    Le Gros, Mark; Larabell, Carolyn A.

    2010-12-14

    A cryogenic immersion microscope whose objective lens is at least partially in contact with a liquid reservoir of a cryogenic liquid, in which reservoir a sample of interest is immersed is disclosed. When the cryogenic liquid has an index of refraction that reduces refraction at interfaces between the lens and the sample, overall resolution and image quality are improved. A combination of an immersion microscope and x-ray microscope, suitable for imaging at cryogenic temperatures is also disclosed.

  3. Scanning Color Laser Microscope

    Science.gov (United States)

    Awamura, D.; Ode, T.; Yonezawa, M.

    1988-01-01

    A confocal color laser microscope which utilizes a three color laser light source (Red: He-Ne, Green: Ar, Blue: Ar) has been developed and is finding useful applications in the semiconductor field. The color laser microscope, when compared to a conventional microscope, offers superior color separation, higher resolution, and sharper contrast. Recently some new functions including a Focus Scan Memory, a Surface Profile Measurement System, a Critical Dimension Measurement system (CD) and an Optical Beam Induced Current Function (OBIC) have been developed for the color laser microscope. This paper will discuss these new features.

  4. Analytical Electron Microscope

    Data.gov (United States)

    Federal Laboratory Consortium — The Titan 80-300 is a transmission electron microscope (TEM) equipped with spectroscopic detectors to allow chemical, elemental, and other analytical measurements to...

  5. Tomographic visualization of stress corrosion cracks in tubing

    International Nuclear Information System (INIS)

    Morris, R.A.; Kruger, R.P.; Wecksung, G.W.

    1979-06-01

    A feasibility study was conducted to determine the possibility of detecting and sizing cracks in reactor cooling water tubes using tomographic techniques. Due to time and financial constraints, only one tomographic reconstruction using the best technique available was made. The results indicate that tomographic reconstructions can, in fact, detect cracks in the tubing and might possibly be capable of measuring the depth of the cracks. Limits of detectability and sensitivity have not been determined but should be investigated in any future work

  6. The Light Microscope.

    Science.gov (United States)

    Baker, W. L.

    1995-01-01

    Describes the function of the various parts of the microscope and their integration in the formation of an optical image. Presents a procedure for setting up a microscope to obtain maximum resolution and contrast for each objective lens at all magnifications. (JRH)

  7. Mailing microscope slides

    Science.gov (United States)

    Many insects feed agriculturally important crops, trees, and ornamental plants and cause millions of dollars of damage annually. Identification for some of these require the preparation of a microscope slide for examination. There are times when a microscope slide may need to be sent away to a speci...

  8. Original circuitry for TOHR tomograph; Une electronique originale pour le tomographe TOHR

    Energy Technology Data Exchange (ETDEWEB)

    Cuzon, J.C.; Pinot, L. [Services Techniques, Inst. de Physique Nucleaire, Paris-11 Univ., 91 - Orsay (France)

    1999-11-01

    Having industrialization in mind, a specific electronics for a high resolution tomograph is designed out of the usual standards of nuclear physics. All the information are converted in the time domain and a fast processor, in front of the data acquisition, carries out the time and energy coincidences. (authors) 2 refs., 2 figs.

  9. Computed Tomographic Perfusion Improves Diagnostic Power of Coronary Computed Tomographic Angiography in Women

    DEFF Research Database (Denmark)

    Penagaluri, Ashritha; Higgins, Angela Y.; Vavere, Andrea L

    2016-01-01

    Background-Coronary computed tomographic angiography (CTA) and myocardial perfusion imaging (CTP) is a validated approach for detection and exclusion of flow-limiting coronary artery disease (CAD), but little data are available on gender-specific performance of these modalities. In this study, we...

  10. Intravenous volume tomographic pulmonary angiography imaging

    Science.gov (United States)

    Ning, Ruola; Strang, John G.; Chen, Biao; Conover, David L.; Yu, Rongfeng

    1999-05-01

    This study presents a new intravenous (IV) tomographic angiography imaging technique, called intravenous volume tomographic digital angiography (VTDA) for cross sectional pulmonary angiography. While the advantages of IV-VTDA over spiral CT in terms of volume scanning time and resolution have been validated and reported in our previous papers for head and neck vascular imaging, the superiority of IV-VTDA over spiral CT for cross sectional pulmonary angiography has not been explored yet. The purpose of this study is to demonstrate the advantage of isotropic resolution of IV-VTDA in the x, y and z directions through phantom and animal studies, and to explore its clinical application for detecting clots in pulmonary angiography. A prototype image intensifier-based VTDA imaging system has been designed and constructed by modifying a GE 8800 CT scanner. This system was used for a series of phantom and dog studies. A pulmonary vascular phantom was designed and constructed. The phantom was scanned using the prototype VTDA system for direct 3D reconstruction. Then the same phantom was scanned using a GE CT/i spiral CT scanner using the routine pulmonary CT angiography protocols. IV contrast injection and volume scanning protocols were developed during the dog studies. Both VTDA reconstructed images and spiral CT images of the specially designed phantom were analyzed and compared. The detectability of simulated vessels and clots was assessed as the function of iodine concentration levels, oriented angles, and diameters of the vessels and clots. A set of 3D VTDA reconstruction images of dog pulmonary arteries was obtained with different IV injection rates and isotropic resolution in the x, y and z directions. The results of clot detection studies in dog pulmonary arteries have also been shown. This study presents a new tomographic IV angiography imaging technique for cross sectional pulmonary angiography. The results of phantom and animal studies indicate that IV-VTDA is

  11. Computed tomographic findings of traumatic intracranial lesions

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Seong Wook; Kim, Il Young; Lee, Byung Ho; Kim, Ki Jeoung; Yoon, Il Gyu [Soonchunhyang University College of Medicine, Seoul (Korea, Republic of)

    1985-10-15

    Traumatic intracranial lesion has been one of the most frequent and serious problem in neurosurgical pathology. Computed tomography made it possible to get prompt diagnosis and surgical intervention of intracranial lesions by its safety, fastness and accuracy. Computed tomographic scan was carried out on 1309 cases at Soonchunhyang Chunan Hospital for 15 months from October 1983 to December 1984. We have reviewed the computed tomographic scans of 264 patients which showed traumatic intracranial lesion. The result were as follows: 1. Head trauma was the most frequent diagnosed disease using computed tomographic scans (57.8%) and among 264 cases the most frequent mode of injury was traffic accident (73.9%). 2. Skull fracture was accompanied in frequency of 69.7% and it was detected in CT in 38.6%: depression fracture was more easily detected in 81%. 3. Conutercoup lesion (9.5%) was usually accompanied with temporal and occipital fracture, and it appeared in lower incidence among pediatric group. 4. Intracranial lesions of all 264 cases were generalized cerebral swelling (24.6%), subdural hematoma (22.3%), epidural hematoma (20.8%), intracerebral hematoma (6.1%), and subarachnoid hemorrhage (3.0%). 5. The shape of hematoma was usually biconvex (92.7%) in acute epidural hematoma and cresentic (100%) in acute subdural hematoma, but the most chronic the case became, they showed planoconvex and bicconvex shapes. 6. Extra-axial hematoma was getting decreased in density as time gone by. 7. Hematoma density was not in direct proportion to serum hemoglobin level as single factor.

  12. Tomographic image reconstruction using training images

    DEFF Research Database (Denmark)

    Soltani, Sara; Andersen, Martin Skovgaard; Hansen, Per Christian

    2017-01-01

    the framework of sparse learning as a regularized non-negative matrix factorization. Incorporating the dictionary as a prior in a convex reconstruction problem, we then find an approximate solution with a sparse representation in the dictionary. The dictionary is applied to non-overlapping patches of the image......We describe and examine an algorithm for tomographic image reconstruction where prior knowledge about the solution is available in the form of training images. We first construct a non-negative dictionary based on prototype elements from the training images; this problem is formulated within...

  13. Tomographic Heating Holder for In Situ TEM

    DEFF Research Database (Denmark)

    Gontard, Lionel C.; Dunin-Borkowski, Rafal E.; Fernández, Asunción

    2014-01-01

    A tomographic heating holder for transmission electron microscopy that can be used to study supported catalysts at temperatures of up to ~1,500°C is described. The specimen is placed in direct thermal contact with a tungsten filament that is oriented perpendicular to the axis of the holder without...... distributions and changes in active surface area are quantified from tilt series of images acquired after subjecting the specimens to increasing temperatures. The porosity of the alumina support and the sintering mechanisms of the catalysts are shown to depend on distance from the heating filament....

  14. E-learn Computed Tomographic Angiography

    DEFF Research Database (Denmark)

    Havsteen, Inger; Christensen, Anders; Nielsen, Jens K

    2012-01-01

    BACKGROUND: Computed tomographic angiography (CTA) is widely available in emergency rooms to assess acute stroke patients. To standardize readings and educate new readers, we developed a 3-step e-learning tool based on the test-teach-retest methodology in 2 acute stroke scenarios: vascular...... the teaching segment; the test size was 40% of the teaching segment size. We assessed diagnostic accuracy and readers' confidence. Results were compared using the Wilcoxon rank sum test. RESULTS: Four neurologic consultants and four radiologic residents completed the program. The vascular occlusion teaching...

  15. An intragastric trichobezoar: computerised tomographic appearance.

    Directory of Open Access Journals (Sweden)

    Morris B

    2000-04-01

    Full Text Available A 26-year-old lady presented with a history of abdominal pain and distension since two months. The ultrasound examination showed an epigastric mass, which was delineated as a filling defect in the stomach on barium studies. The computerised tomographic scan showed a gastric mass with pockets of air in it, without post-contrast enhancement. This case highlights the characteristic appearance on computerised tomography of a bezoar within the stomach, a feature that is not commonly described in medical literature.

  16. Computed tomographic study in children with microcephaly

    International Nuclear Information System (INIS)

    Ito, Masatoshi; Okuno, Takehiko; Mikawa, Haruki

    1989-01-01

    Computed tomographic (CT) brain scanning was performed on fifty-eight infants and children with microcephaly. CT scans were useful for detecting unsuspected brain lesions and for diagnosing underlying diseases. The head size did not correlate with the CT findings, the degree of mental retardation, or the existence of motor disturbance or epilepsy. On the other hand, the CT findings were correlated with the degree of mental retardation, and the existence of motor disturbance or epilepsy. CT scans were useful for determining the prognosis of the microcephaly. (author)

  17. Tomographs based on non-conventional radiation sources and methods

    International Nuclear Information System (INIS)

    Barbuzza, R.; Fresno, M. del; Venere, Marcelo J.; Clausse, Alejandro; Moreno, C.

    2000-01-01

    Computer techniques for tomographic reconstruction of objects X-rayed with a compact plasma focus (PF) are presented. The implemented reconstruction algorithms are based on stochastic searching of solutions of Radon equation, using Genetic Algorithms and Monte Carlo methods. Numerical experiments using actual projections were performed concluding the feasibility of the application of both methods in tomographic reconstruction problem. (author)

  18. Computerized tomographic in non-destructive testing

    International Nuclear Information System (INIS)

    Lopes, R.T.

    1988-01-01

    The process of computerized tomography has been developed for medical imaging purposes using tomographs with X-ray, and little attention has been given to others possibles applications of technique, because of its cost. As an alternative for the problem, we constructed a Tomographic System (STAC-1), using gamma-rays, for nonmedical applications. In this work we summarize the basic theory of reconstructing images using computerized tomography and we describe the considerations leading to the development of the experimental system. The method of reconstruction image implanted in the system is the filtered backprojection or convolution, with a digital filters system to carried on a pre-filtering in the projections. The experimental system is described, with details of control and the data processing. An alternative and a complementary system, using film as a detector is shown in preliminary form . This thesis discuss and shows the theorical and practical aspects, considered in the construction of the STAC-1, and also its limitations and apllications [pt

  19. Computed tomographic features of canine nonparenchymal hemangiosarcoma.

    Science.gov (United States)

    Fukuda, Shoko; Kobayashi, Tetsuya; Robertson, Ian D; Oshima, Fukiko; Fukazawa, Eri; Nakano, Yuko; Ono, Shin; Thrall, Donald E

    2014-01-01

    The purpose of this retrospective study was to describe pre- and postcontrast computed tomographic (CT) characteristics of confirmed nonparenchymal hemangiosarcoma in a group of dogs. Medical records were searched during the period of July 2003 and October 2011 and dogs with histologically confirmed nonparenchymal hemangiosarcoma and pre- and postcontrast CT images were recruited. Two observers recorded a consensus opinion for the following CT characteristics for each dog: largest transverse tumor diameter, number of masses, general tumor shape, character of the tumor margin, precontrast appearance, presence of dystrophic calcification, presence of postcontrast enhancement, pattern of postcontrast enhancement, presence of regional lymphadenopathy, and presence of associated cavitary fluid. A total of 17 dogs met inclusion criteria. Tumors were located in the nasal cavity, muscle, mandible, mesentery, subcutaneous tissue, and retroperitoneal space. Computed tomographic features of nonparenchymal hemangiosarcoma were similar to those of other soft tissue sarcomas, with most tumors being heterogeneous in precontrast images, invasive into adjacent tissue, and heterogeneously contrast enhancing. One unexpected finding was the presence of intense foci of contrast enhancement in 13 of the 17 tumors (76%). This appearance, which is not typical of other soft tissue sarcomas, was consistent with contrast medium residing in vascular channels. Findings indicated that there were no unique distinguishing CT characteristics for nonparenchymal hemangiosarcoma in dogs; however, the presence of highly attenuating foci of contrast enhancement may warrant further investigation in prospective diagnostic sensitivity and treatment outcome studies. © 2014 American College of Veterinary Radiology.

  20. Unusual tomographic findings of complicated necrotizing pancreatitis

    Directory of Open Access Journals (Sweden)

    Rosa Maria Silveira Sigrist

    2013-12-01

    Full Text Available Acute pancreatitis (AP is a potential life-threatening disease, which originates from inflammatory involvement of the pancreas and surrounding tissues. Serious complications eventuate and treatment is difficult. AP is classified in both interstitial edematous pancreatitis, which occurs in 70-80% of patients, and necrotizing pancreatitis, which occurs in 20-30% of patients. Diagnosis is based on the presence of two of the following criteria: abdominal pain, increased serum determination of amylase and/or lipase more than three times the reference value, and characteristic tomographic findings. Among the latter, there is the pancreatic and surrounding tissue damage as well as that related to distant organ involvement. This case report shows the fatal case of a male patient with a history of heavy alcoholic abuse admitted with the diagnosis of necrotizing pancreatitis. The authors call attention to the unusual tomographic findings; namely, a huge duodenal hematoma and a large hemoperitoneum, ischemic involvement of the spleen and kidneys, as well as pancreatic and peripancreatic necrosis.

  1. Assessment of Petrological Microscopes.

    Science.gov (United States)

    Mathison, Charter Innes

    1990-01-01

    Presented is a set of procedures designed to check the design, ergonomics, illumination, function, optics, accessory equipment, and image quality of a microscope being considered for purchase. Functions for use in a petrology or mineralogy laboratory are stressed. (CW)

  2. Scanning Auger Electron Microscope

    Data.gov (United States)

    Federal Laboratory Consortium — A JEOL model 7830F field emission source, scanning Auger microscope.Specifications / Capabilities:Ultra-high vacuum (UHV), electron gun range from 0.1 kV to 25 kV,...

  3. Putting structure into context: fitting of atomic models into electron microscopic and electron tomographic reconstructions.

    Science.gov (United States)

    Volkmann, Niels

    2012-02-01

    A complete understanding of complex dynamic cellular processes such as cell migration or cell adhesion requires the integration of atomic level structural information into the larger cellular context. While direct atomic-level information at the cellular level remains inaccessible, electron microscopy, electron tomography and their associated computational image processing approaches have now matured to a point where sub-cellular structures can be imaged in three dimensions at the nanometer scale. Atomic-resolution information obtained by other means can be combined with this data to obtain three-dimensional models of large macromolecular assemblies in their cellular context. This article summarizes some recent advances in this field. Copyright © 2011 Elsevier Ltd. All rights reserved.

  4. Comparative study of the macroscopic finding, conventional tomographic imaging, and computed tomographic imaging in locating the mandibular canal

    International Nuclear Information System (INIS)

    Choi, Hang Moon; You, Dong Soo

    1995-01-01

    The purpose of this study was comparison of conventional tomography with reformatted computed tomography for dental implant in locating the mandibular canal. Five dogs were used and after conventional tomographs and fitted computed tomographs were taken, four dentist traced all films. Mandibles were sectioned with 2 mm slice thickness and the sections were then radiographed (contact radiography). Each radiograpic image was traced and linear measurements were made from mandibular canal to alveolar crest, buccal cortex, lingual cortex, and inferior border. The following results were obtained; 1. Reformatted computed tomographs were exacter than conventional tomography by alveolar crest to canal length of -0.6 mm difference between real values and radiographs 2. The average measurements of buccal cortex to mandibular canal width and lingual cortex to mandibular canal width of conventional tomographs were exacter than reformatted computed tomographs, but standard deviations were higher than reformatted computed tomographs. 3. Standard deviations of reformatted computed tomographs were lower than conventional tomographs at all comparing sites 4. At reformatted computed tomography 62.5% of the measurements performed were within ±1 mm of the true value, and at conventional tomography 24.1% were. 5. Mandibular canal invisibility was 0.8% at reformatted computed tomography and 9.2% at conventional tomography. Reformatted computed tomography has been shown to be more useful radiographic technique for assessment of the mandibular canal than conventional tomography.

  5. Development of a new automatic nuclear emulsion scanning system, S-UTS, with continuous 3D tomographic image read-out

    Science.gov (United States)

    Morishima, K.; Nakano, T.

    2010-04-01

    The previous version of the automatic nuclear emulsion scanning system had a limit on read-out speed of several microscope views per second (views/s). This was due to unavoidable mechanical vibration when microscope stage was stopped to acquire tomographic images along the optical axis in emulsion. To overcome this limit, we succeeded in developing optics synchronized to stage movement so that tomographic images can be acquired without stopping a stage. This new system, S-UTS, is now operative with scanning speed of 50 views/s, or 72 cm2/h, with high efficiency and sub-μm precision. It plays an essential role in the OPERA experiment at CERN.

  6. SPICE benchmark for global tomographic methods

    Science.gov (United States)

    Qin, Yilong; Capdeville, Yann; Maupin, Valerie; Montagner, Jean-Paul; Lebedev, Sergei; Beucler, Eric

    2008-11-01

    The existing global tomographic methods result in different models due to different parametrization, scale resolution and theoretical approach. To test how current imaging techniques are limited by approximations in theory and by the inadequacy of data quality and coverage, it is necessary to perform a global-scale benchmark to understand the resolving properties of each specific imaging algorithm. In the framework of the Seismic wave Propagation and Imaging in Complex media: a European network (SPICE) project, it was decided to perform a benchmark experiment of global inversion algorithms. First, a preliminary benchmark with a simple isotropic model is carried out to check the feasibility in terms of acquisition geometry and numerical accuracy. Then, to fully validate tomographic schemes with a challenging synthetic data set, we constructed one complex anisotropic global model, which is characterized by 21 elastic constants and includes 3-D heterogeneities in velocity, anisotropy (radial and azimuthal anisotropy), attenuation, density, as well as surface topography and bathymetry. The intermediate-period (>32 s), high fidelity anisotropic modelling was performed by using state-of-the-art anisotropic anelastic modelling code, that is, coupled spectral element method (CSEM), on modern massively parallel computing resources. The benchmark data set consists of 29 events and three-component seismograms are recorded by 256 stations. Because of the limitation of the available computing power, synthetic seismograms have a minimum period of 32 s and a length of 10 500 s. The inversion of the benchmark data set demonstrates several well-known problems of classical surface wave tomography, such as the importance of crustal correction to recover the shallow structures, the loss of resolution with depth, the smearing effect, both horizontal and vertical, the inaccuracy of amplitude of isotropic S-wave velocity variation, the difficulty of retrieving the magnitude of azimuthal

  7. Tomographic patient registration and conformal avoidance tomotherapy

    Science.gov (United States)

    Aldridge, Jennifer Stacy

    Development of tomotherapy has led to the emergence of several processes, providing the basis for many unique investigative opportunities. These processes include setup verification, tomographic verification, megavoltage dose reconstruction, and conformal avoidance tomotherapy. Setup verification and conformal avoidance tomotherapy, in particular, are two closely intertwined matters. In order to avoid critical structures located within or adjacent to indistinct tumor regions, accurate patient positioning from fraction to fraction must be ensured. With tomographic patient registration, a higher level of assurance is offered than with traditional positioning methods. Translational and rotational offsets are calculated directly from projection data using cross- correlation or fast Fourier transforms. Experiments assessing the algorithm's ability to calculate individual offsets were conducted using the University of Wisconsin's Tomotherapy Benchtop. These experiments indicate statistical errors within +/-1 mm for offsets up to approximately 20 mm, with maximum offset errors of about +/-2 mm for displacements up to 35 mm. The angular offset component is within +/-2°. To evaluate the registration process as a whole, experimental results from a few multi-parameter examples are also analyzed. With the development of tomographic patient registration in projection space, efforts to promote further sparing of critical structures are justified. Conformal avoidance tomotherapy has as its objective to treat an indistinct tumor region while conformally avoiding any normal critical structures in that region. To demonstrate the advantages of conformal avoidance tomotherapy, conventional and tomotherapy treatments are contrasted for both nasopharyngeal and breast carcinoma cases. For initial research efforts, computed tomography data sets of a human male and female were obtained via the ``Visible Human Project''. Since these data sets are on the order of hundreds of megabytes, both

  8. Reconstruction of Axial Tomographic High Resolution Data from Confocal Fluorescence Microscopy: A Method for Improving 3D FISH Images

    Directory of Open Access Journals (Sweden)

    R. Heintzmann

    2000-01-01

    Full Text Available Fluorescent confocal laser scanning microscopy allows an improved imaging of microscopic objects in three dimensions. However, the resolution along the axial direction is three times worse than the resolution in lateral directions. A method to overcome this axial limitation is tilting the object under the microscope, in a way that the direction of the optical axis points into different directions relative to the sample. A new technique for a simultaneous reconstruction from a number of such axial tomographic confocal data sets was developed and used for high resolution reconstruction of 3D‐data both from experimental and virtual microscopic data sets. The reconstructed images have a highly improved 3D resolution, which is comparable to the lateral resolution of a single deconvolved data set. Axial tomographic imaging in combination with simultaneous data reconstruction also opens the possibility for a more precise quantification of 3D data. The color images of this publication can be accessed from http://www.esacp.org/acp/2000/20‐1/heintzmann.htm. At this web address an interactive 3D viewer is additionally provided for browsing the 3D data. This java applet displays three orthogonal slices of the data set which are dynamically updated by user mouse clicks or keystrokes.

  9. Airborne Tomographic Swath Ice Sounding Processing System

    Science.gov (United States)

    Wu, Xiaoqing; Rodriquez, Ernesto; Freeman, Anthony; Jezek, Ken

    2013-01-01

    Glaciers and ice sheets modulate global sea level by storing water deposited as snow on the surface, and discharging water back into the ocean through melting. Their physical state can be characterized in terms of their mass balance and dynamics. To estimate the current ice mass balance, and to predict future changes in the motion of the Greenland and Antarctic ice sheets, it is necessary to know the ice sheet thickness and the physical conditions of the ice sheet surface and bed. This information is required at fine resolution and over extensive portions of the ice sheets. A tomographic algorithm has been developed to take raw data collected by a multiple-channel synthetic aperture sounding radar system over a polar ice sheet and convert those data into two-dimensional (2D) ice thickness measurements. Prior to this work, conventional processing techniques only provided one-dimensional ice thickness measurements along profiles.

  10. Synthetic Dataset To Benchmark Global Tomographic Methods

    Science.gov (United States)

    Qin, Yilong; Capdeville, Yann; Maupin, Valerie; Montagner, Jean-Paul

    2006-11-01

    A new set of global synthetic seismograms calculated in a three-dimensional (3-D), heterogeneous, anisotropic, anelastic model of the Earth using the spectral element method has been released by the European network SPICE (Seismic Wave Propagation and Imaging in Complex Media: a European Network). The set consists of 7424 three-component records with a minimum period of 32 seconds, a sampling rate of one second, and a duration of 10,500 seconds. The aim of this synthetic data set is to conduct a blind test of existing global tomographic methods based on long-period data, in order to test how current imaging techniques are limited by approximations in theory and by the inadequacy of data quality and coverage.

  11. Computed tomographic investigations on intraventricular hematomas

    International Nuclear Information System (INIS)

    Laber-Szillat, S.

    1982-01-01

    This work investigated in 106 patients with intraventricular hematomas all the known factors which can have an influence on prognosis: age, sex, anamnesis of the patients, size, extent and localization of the intracranial bleeding, underlying angiopathy and differences between arterial and venous and spontaneous and traumatic bleedings. It was shown that the state of mind was the deciding prognostic factor, whereby viligance was the cumulative expression of all other investigated influences. A computed tomography (CT) examination is deciding in the question of operative hydrocephalus care. In 13 patients it was further shown, how clearly CT results and brain dissection allowed themselves to be compared. The computed tomographic examination method is best suited to achieve even physiological and more extensive prognostic possibilities. (orig.) [de

  12. Collimated trans-axial tomographic scintillation camera

    International Nuclear Information System (INIS)

    1980-01-01

    The objects of this invention are first to reduce the time required to obtain statistically significant data in trans-axial tomographic radioisotope scanning using a scintillation camera. Secondly, to provide a scintillation camera system to increase the rate of acceptance of radioactive events to contribute to the positional information obtainable from a known radiation source without sacrificing spatial resolution. Thirdly to reduce the scanning time without loss of image clarity. The system described comprises a scintillation camera detector, means for moving this in orbit about a cranial-caudal axis relative to a patient and a collimator having septa defining apertures such that gamma rays perpendicular to the axis are admitted with high spatial resolution, parallel to the axis with low resolution. The septa may be made of strips of lead. Detailed descriptions are given. (U.K.)

  13. Collimated trans-axial tomographic scintillation camera

    International Nuclear Information System (INIS)

    1980-01-01

    The principal problem in trans-axial tomographic radioisotope scanning is the length of time required to obtain meaningful data. Patient movement and radioisotope migration during the scanning period can cause distortion of the image. The object of this invention is to reduce the scanning time without degrading the images obtained. A system is described in which a scintillation camera detector is moved to an orbit about the cranial-caudal axis relative to the patient. A collimator is used in which lead septa are arranged so as to admit gamma rays travelling perpendicular to this axis with high spatial resolution and those travelling in the direction of the axis with low spatial resolution, thus increasing the rate of acceptance of radioactive events to contribute to the positional information obtainable without sacrificing spatial resolution. (author)

  14. Computer tomographic and sonographic diagnosis of echinococcus

    Energy Technology Data Exchange (ETDEWEB)

    Schulze, K.; Huebener, K.H.; Klott, K.; Jenss, H.; Baehr, R. (Tuebingen Univ. (Germany, F.R.). Medizinisches Strahleninstitut und Roentgenabteilung; Tuebingen Univ. (Germany, F.R.). Medizinische Klinik; Tuebingen Univ. (Germany, F.R.). Chirurgische Klinik und Poliklinik)

    1980-05-01

    In 33 patients (18 cystic echinococci, 15 alveolar) both methods produced the following findings which could be correlated with the pathological results: single or multi-centric lesions, sharp or indefinite demarkation and abnormalities in the shape and size of the liver. The sonographic findings were analysed with respect to the echo characteristics, whereas the computer tomographically demonstrated lesions were examined densitometrically in order to show calcification. Both methods demonstrate the pathological changes satisfactorily. Computer tomography is more effective in alveolar echinococcus lesions by showing the different types of calcification, whereas sonography provides a more accurate picture of the internal structure of the cysts in cystic echinococcus. Comparison of the methods in 19 patients examined by both showed a high accuracy in each method, but sonography was relatively poor in demonstrating lesions in the spleen.

  15. Computed tomographic findings of intracranial acute leukemia

    Energy Technology Data Exchange (ETDEWEB)

    Park, Dong Woo; Ryu, Weon Don; Kim, Jong Sung; Koh, Byung Hee; Jeon, Seok Chol; Lee, Seung Ro; Hahm, Chang Kok [Hanyang University College of Medicine, Seoul (Korea, Republic of)

    1990-07-15

    Computed tomographic (CT) abnormalities in the brain were retrospectively analyzed in 16 of 103 patients with acute leukemia confirmed by CSF cytology or combined surgery at Hanyang University Hospital, from August 1980 to August 1989. The results were as follows : 1. With FAB classification, the most frequent pathologic type was L1 : 8 cases (50%) 2. The range of age distribution showed typical pattern that ALL occurred below the 15 years old, and AML, over 15 years old. 3. Abnormal CT findings were ; Meningitis(2 cases), Mass(3), Thrombosis(1), Infarction(2), Edema(1), Hemorrhage(7), Hydrocephalus(2), Atrophy(2). 4. Most of infracranial hemorrhage were seen in M{sub 2} and M{sub 3} type.

  16. Computed tomographic findings of cerebral arterial ectasia

    International Nuclear Information System (INIS)

    Choi, Woo Suk; Ko, Young Ho; Lim, Jae Hoon

    1987-01-01

    The computed tomographic findings of cerebral arterial ectasia in 8 patients, of which 5 cases were angiographically documented, are reported. The ecstatic arteries, located predominantly in the suprasellar and interpeduncular cisterns, appeared as serpignous, tubular structures on the unenhanced scan. The enhanced CT scan demonstrated dense, sharply defined, homogeneous intraluminal enhancement. Until recently, the diagnosis of cerebral arterial ectasia was usually established by angiography. With introduction of CT it has become possible to noninvasively identify and characterize this vascular disorder and its associated intracranial complications. The vertebrobasilar dolichoectasia may be diagnosed by CT as an extra-axial lesion in the cerebellopontine angle. It enhances in a tubular fashion after intravenous injection of contrast.

  17. Advanced Ultrasonic Tomograph of Children's Bones

    Science.gov (United States)

    Lasaygues, Philippe; Lefebvre, Jean-Pierre; Guillermin, Régine; Kaftandjian, Valérie; Berteau, Jean-Philippe; Pithioux, Martine; Petit, Philippe

    This study deals with the development of an experimental device for performing ultrasonic computed tomography (UCT) on bone in pediatric degrees. The children's bone tomographs obtained in this study, were based on the use of a multiplexed 2-D ring antenna (1 MHz and 3 MHz) designed for performing electronic and mechanical scanning. Although this approach is known to be a potentially valuable means of imaging objects with similar acoustical impedances, problems arise when quantitative images of more highly contrasted media such as bones are required. Various strategies and various mathematical procedures for modeling the wave propagation based on Born approximations have been developed at our laboratory, which are suitable for use with pediatric cases. Inversions of the experimental data obtained are presented.

  18. Some principles in choosing parameters of magnetic resonance tomographs

    Science.gov (United States)

    Volobuev, A. N.

    2017-01-01

    The problem of amplifying the signal that ensures the visualization of internal organs in the magnetic resonance tomograph due to the optimal selection of some of its parameters has been considered. The operating principle of the tomograph has been analyzed. The relation between the angle of the magnetic moment precession in hydrogen nuclei in an organism, the frequency of the ac magnetic field exciting this precession, and the constant magnetic field used has been determined using quantum-mechanical concepts. This relation makes it possible to determine the optimal parameters for tomograph operation.

  19. Electron microscope studies

    Energy Technology Data Exchange (ETDEWEB)

    Crewe, A.V.; Kapp, O.H.

    1992-07-01

    This is a report covering the research performed in the Crewe laboratory between 1964 and 1992. Because of limitations of space we have provided relatively brief summaries of the major research directions of the facility during these years. A complete bibliography has been included and we have referenced groups of pertinent publications at the beginning of each section. This report summarizes our efforts to develop better electron microscopes and chronicles many of the experimental programs, in materials science and biology, that acted both as a stimulus to better microscope design and also as a testing ground for many instrumental innovations.

  20. Electron microscope studies

    International Nuclear Information System (INIS)

    Crewe, A.V.; Kapp, O.H.

    1992-01-01

    This is a report covering the research performed in the Crewe laboratory between 1964 and 1992. Because of limitations of space we have provided relatively brief summaries of the major research directions of the facility during these years. A complete bibliography has been included and we have referenced groups of pertinent publications at the beginning of each section. This report summarizes our efforts to develop better electron microscopes and chronicles many of the experimental programs, in materials science and biology, that acted both as a stimulus to better microscope design and also as a testing ground for many instrumental innovations

  1. Scanning transmission electron microscope

    NARCIS (Netherlands)

    Kruit, P.

    2006-01-01

    The invention relates to a scanning transmission electron microscope comprising an electron source, an electron accelerator and deflection means for directing electrons emitted by the electron source at an object to be examined, and in addition a detector for detecting electrons coming from the

  2. MICROSCOPIC, PHYSICOCHEMICAL AND CHROMATOGRAPHIC ...

    African Journals Online (AJOL)

    Peters

    MICROSCOPIC, PHYSICOCHEMICAL AND CHROMATOGRAPHIC. FINGERPRINTS OF LEAVES OF NIGERIAN CASSIA TORA LINN. Fatokun Omolola T1*., EsievoKevwe B2., Ugbabe Grace E3. and Kunle Oluyemisi F4. Department of Medicinal Plant Research and Traditional Medicine, National Institute for.

  3. SPM: Scanning positron microscope

    Directory of Open Access Journals (Sweden)

    Marcel Dickmann

    2015-08-01

    Full Text Available The Munich scanning positron microscope, operated by the Universität der Bundeswehr München and the Technische Universität München, located at NEPOMUC, permits positron lifetime measurements with a lateral resolution in the µm range and within an energy range of 1 – 20 keV.

  4. Microscope on Mars

    Science.gov (United States)

    2004-01-01

    This image taken at Meridiani Planum, Mars by the panoramic camera on the Mars Exploration Rover Opportunity shows the rover's microscopic imager (circular device in center), located on its instrument deployment device, or 'arm.' The image was acquired on the ninth martian day or sol of the rover's mission.

  5. Making Art with Microscopes

    Science.gov (United States)

    Benedis-Grab, Gregory

    2011-01-01

    Interdisciplinary teaching is a great way to focus on overarching concepts and help students make connections across disciplines. Historically, art and science have been connected disciplines. The botanical prints of the 18th and 19th centuries and early work with microscopes are two examples of a need for strong artistic skills in the science…

  6. Terahertz scanning probe microscope

    NARCIS (Netherlands)

    Klapwijk, T.M.

    2014-01-01

    The invention provides aterahertz scanning probe microscope setup comprising (i) a terahertz radiation source configured to generate terahertz radiation; (ii) a terahertz lens configured to receive at least part of the terahertz radiation from the terahertz radiation source; (iii) a cantilever unit

  7. Radiographic test phantom for computed tomographic lung nodule analysis

    International Nuclear Information System (INIS)

    Zerhouni, E.A.

    1987-01-01

    This patent describes a method for evaluating a computed tomograph scan of a nodule in a lung of a human or non-human animal. The method comprises generating a computer tomograph of a transverse section of the animal containing lung and nodule tissue, and generating a second computer tomograph of a test phantom comprising a device which simulates the transverse section of the animal. The tissue simulating portions of the device are constructed of materials having radiographic densities substantially identical to those of the corresponding tissue in the simulated transverse section of the animal and have voids therein which simulate, in size and shape, the lung cavities in the transverse section and which contain a test reference nodule constructed of a material of predetermined radiographic density which simulates in size, shape and position within a lung cavity void of the test phantom the nodule in the transverse section of the animal and comparing the respective tomographs

  8. Computed tomographic determination of tracheal dimensions in children and adolescents

    International Nuclear Information System (INIS)

    Griscom, N.T.

    1982-01-01

    A computed tomographic system for determining the internal diameters, cross-sectional area, and length of the trachea in children and adolescents was developed. Intraluminal volumes were calculated from these measurements.The results of 18 analyses are reported

  9. Image interface in Java for tomographic reconstruction in nuclear medicine

    International Nuclear Information System (INIS)

    Andrade, M.A.; Silva, A.M. Marques da

    2004-01-01

    The aim of this study is to implement a software for tomographic reconstruction of SPECT data from Nuclear Medicine with a flexible interface design, cross-platform, written in Java. Validation tests were performed based on SPECT simulated data. The results showed that the implemented algorithms and filters agree with the theoretical context. We intend to extend the system by implementing additional tomographic reconstruction techniques and Java threads, in order to provide simultaneously image processing. (author)

  10. Three-dimensional phase-contrast X-ray microtomography with scanning–imaging X-ray microscope optics

    International Nuclear Information System (INIS)

    Takeuchi, Akihisa; Uesugi, Kentaro; Suzuki, Yoshio

    2013-01-01

    A novel three-dimensional X-ray microtomographic micro-imaging system which enables simultaneous measurement of differential phase contrast and absorption contrast has been developed. The optical system consists of a scanning microscope with one-dimensional focusing device and an imaging microscope with one-dimensional objective. A three-dimensional (3D) X-ray tomographic micro-imaging system has been developed. The optical system is based on a scanning–imaging X-ray microscope (SIXM) optics, which is a hybrid system consisting of a scanning microscope optics with a one-dimensional (1D) focusing (line-focusing) device and an imaging microscope optics with a 1D objective. In the SIXM system, each 1D dataset of a two-dimensional (2D) image is recorded independently. An object is illuminated with a line-focused beam. Positional information of the region illuminated by the line-focused beam is recorded with the 1D imaging microscope optics as line-profile data. By scanning the object with the line focus, 2D image data are obtained. In the same manner as for a scanning microscope optics with a multi-pixel detector, imaging modes such as phase contrast and absorption contrast can be arbitrarily configured after the image data acquisition. By combining a tomographic scan method and the SIXM system, quantitative 3D imaging is performed. Results of a feasibility study of the SIXM for 3D imaging are shown

  11. From tomographic images to fault heterogeneities

    Directory of Open Access Journals (Sweden)

    A. Amato

    1994-06-01

    Full Text Available Local Earthquake Tomography (LET is a useful tool for imaging lateral heterogeneities in the upper crust. The pattern of P- and S-wave velocity anomalies, in relation to the seismicity distribution along active fault zones. can shed light on the existence of discrete seismogenic patches. Recent tomographic studies in well monitored seismic areas have shown that the regions with large seismic moment release generally correspond to high velocity zones (HVZ's. In this paper, we discuss the relationship between the seismogenic behavior of faults and the velocity structure of fault zones as inferred from seismic tomography. First, we review some recent tomographic studies in active strike-slip faults. We show examples from different segments of the San Andreas fault system (Parkfield, Loma Prieta, where detailed studies have been carried out in recent years. We also show two applications of LET to thrust faults (Coalinga, Friuli. Then, we focus on the Irpinia normal fault zone (South-Central Italy, where a Ms = 6.9 earthquake occurred in 1980 and many thousands of attershock travel time data are available. We find that earthquake hypocenters concentrate in HVZ's, whereas low velocity zones (LVZ’ s appear to be relatively aseismic. The main HVZ's along which the mainshock rupture bas propagated may correspond to velocity weakening fault regions, whereas the LVZ's are probably related to weak materials undergoing stable slip (velocity strengthening. A correlation exists between this HVZ and the area with larger coseismic slip along the fault, according to both surface evidence (a fault scarp as high as 1 m and strong ground motion waveform modeling. Smaller wave-length, low-velocity anomalies detected along the fault may be the expression of velocity strengthening sections, where aseismic slip occurs. According to our results, the rupture at the nucleation depth (~ 10-12 km is continuous for the whole fault lenoth (~ 30 km, whereas at shallow depth

  12. Gamma Ray Tomographic Scan Method for Large Scale Industrial Plants

    International Nuclear Information System (INIS)

    Moon, Jin Ho; Jung, Sung Hee; Kim, Jong Bum; Park, Jang Geun

    2011-01-01

    The gamma ray tomography systems have been used to investigate a chemical process for last decade. There have been many cases of gamma ray tomography for laboratory scale work but not many cases for industrial scale work. Non-tomographic equipment with gamma-ray sources is often used in process diagnosis. Gamma radiography, gamma column scanning and the radioisotope tracer technique are examples of gamma ray application in industries. In spite of many outdoor non-gamma ray tomographic equipment, the most of gamma ray tomographic systems still remained as indoor equipment. But, as the gamma tomography has developed, the demand on gamma tomography for real scale plants also increased. To develop the industrial scale system, we introduced the gamma-ray tomographic system with fixed detectors and rotating source. The general system configuration is similar to 4 th generation geometry. But the main effort has been made to actualize the instant installation of the system for real scale industrial plant. This work would be a first attempt to apply the 4th generation industrial gamma tomographic scanning by experimental method. The individual 0.5-inch NaI detector was used for gamma ray detection by configuring circular shape around industrial plant. This tomographic scan method can reduce mechanical complexity and require a much smaller space than a conventional CT. Those properties make it easy to get measurement data for a real scale plant

  13. Distance weighting for improved tomographic reconstructions

    International Nuclear Information System (INIS)

    Koeppe, R.A.; Holden, J.E.

    1984-01-01

    An improved method for the reconstruction of emission computed axial tomography images has been developed. The method is a modification of filtered back-projection, where the back projected values are weighted to reflect the loss of formation, with distance from the camera, which is inherent in gamma camera imaging. This information loss is a result of: loss of spatial resolution with distance, attenuation, and scatter. The weighting scheme can best be described by considering the contributions of any two opposing views to the reconstruction image pixels. The weight applied to the projections of one view is set to equal the relative amount of the original activity that was initially received in that projection, assuming a uniform attenuating medium. This yields a weighting value which is a function of distance into the image with a value of one for pixels ''near the camera'', a value of .5 at the image center, and a value of zero on the opposite side. Tomographic reconstructions produced with this method show improved spatial resolution when compared to conventional 360 0 reconstructions. The improvement is in the tangential direction, where simulations have indicated a FWHM improvement of 1 to 1.5 millimeters. The resolution in the radial direction is essentially the same for both methods. Visual inspection of the reconstructed images show improved resolution and contrast

  14. Computed Tomographic Artifacts in Maxillofacial Surgery.

    Science.gov (United States)

    Kim, Jun Ho; Arita, Emiko Saito; Pinheiro, Lucas Rodrigues; Yoshimoto, Marcelo; Watanabe, Plauto Christopher Aranha; Cortes, Arthur Rodriguez Gonzalez

    2018-01-01

    The present study aimed to present 4 cases and to undertake a systematic review on the current knowledge of the impact of cone beam computed tomographic (CBCT) artifacts on oral and maxillofacial surgical planning and follow-up. The MEDLINE (PubMed) database was searched for the period from February 2004 to February 2017, for studies on the impact of CBCT artifacts on surgical planning of oral and maxillofacial surgeries. The PRISMA statement was followed during data assessment and extraction. As a result, data extraction included information regarding: the use of CBCT to plan or follow-up oral and maxillofacial surgeries, presence and type identification of a CBCT artifact, and details on the impact of artifacts on image quality and/or surgical planning. Four cases were selected to illustrate the topic. The search strategy yielded 408 publications in MEDLINE (PubMed). An initial screening of the publications was performed using abstracts and key words. After application of exclusion criteria, a total of 11 studies were finally identified as eligible to be discussed. Studies revealed 3 main types of artifact: beam hardening, streak, and motion artifacts. Most of the studies suggest that artifacts significantly affect oral and maxillofacial surgical planning and follow-up, despite of allowing for identification of metal projectiles in cases of maxillofacial trauma. CBCT artifacts have a significant impact on oral and maxillofacial surgical planning and follow-up.

  15. Formation of tomographic images with neutrons

    International Nuclear Information System (INIS)

    Duarte, A.; Tenreiro, C; Valencia, J; Steinman, G.; Henriquez, C

    2000-01-01

    The possibility of having a non-destructive method of analysis for archaeological and paleontological samples is of interest. A special group of fossil samples has come to our attention, which because of their value should be preserved and, therefore, the availability of an indirect, non-destructive, non contaminating analytical technique is important. The strong absorption of usual kinds of radiation by a fossilized sample restricts the application of conventional methods of analysis. A type of radiation that is not completely attenuated by thick samples, in sizes that are typical in paleontology, is necessary. Neutrons may be considered as an ideal non-invasive probe with the possibility of developing a technique for the formation and analysis of images. A technique has been developed for the spatial reconstruction of the contents of a fossilized sample (tomography) with neutrons, without touching or altering the sample in any way. The neutron beam was extracted from the RECH-1 reactor belonging to the CCHEN, La Reina. The tomographic images of the contents of a fossilized egg are presented for the first time and represent views or cuts of the content as well as a set that permits the three dimensional reconstruction of the inside of the object and its subsequent animation in graphic format. This project developed a technique for taking neutron radiographs of this kind of sample including the numerical algorithms and the treatment and formation of the images (CW)

  16. Computed tomographic findings of cerebral paragonimiasis

    International Nuclear Information System (INIS)

    Sung, Nak Kwan; Nam, Kyung Jin; Park, Churl Min; Eun, Chung Kie; Lee, Sun Wha

    1983-01-01

    Paragonimiasis is widely distributed in Far East and Southeast Asia, particularly in Korea. The central nervous system is the most frequent location for paragonimiasis outside the lungs. We analyzed the computed tomographic findings of 17 cases which were diagnosed pathologically and clinically as cerebral paragonimiasis. The results were as follows: 1. The ratio of male to female was 10 : 7 and about 88% of cases were under the age of 40 years. 2. The common locations of cerebral paragonimiasis were the occipital (12 cases) and temporal (11 cases) lobes. 3. Precontrast CT findings of cerebral paragonimiasis were low density with calcifications in 6 cases, low and isodensities in 4 cases, mixed densities in 3 cases, only low density in 2 cases and only calcification in 2 cases. Hydrocephalus (7 cases), mass effect (6 cases), atrophic change (6 cases) and cyst formation (3 cases) were associated. 4. The shape of calcifications in CT scan were soap-bubble or ring in 6 cases, nodular or oval in 6 cases, stipple in 4 cases and amorphous conglomerated in 2 cases. 5. The contrast -enhanced 8 cases were 5 ring or rim like, 2 nodular and 1 irregular enhancements, while 9 cases were not enhanced

  17. Collimator trans-axial tomographic scintillation camera

    International Nuclear Information System (INIS)

    Jaszczak, Ronald J.

    1979-01-01

    An improved collimator is provided for a scintillation camera system that employs a detector head for transaxial tomographic scanning. One object of this invention is to significantly reduce the time required to obtain statistically significant data in radioisotope scanning using a scintillation camera. Another is to increase the rate of acceptance of radioactive events to contribute to the positional information obtainable from a radiation source of known strength without sacrificing spatial resolution. A further object is to reduce the necessary scanning time without degrading the images obtained. The collimator described has apertures defined by septa of different radiation transparency. The septa are aligned to provide greater radiation shielding from gamma radiation travelling within planes perpendicular to the cranial-caudal axis and less radiation shielding from gamma radiation travelling within other planes. Septa may also define apertures such that the collimator provides high spatial resolution of gamma rays traveling within planes perpendicular to the cranial-caudal axis and directed at the detector and high radiation sensitivity to gamma radiation travelling other planes and indicated at the detector. (LL)

  18. Computed tomographic findings of hepatocellular carcinoma

    International Nuclear Information System (INIS)

    Jo, In Su; Jong, Woo Yung; Lee, Jong Yul; Choi, Han Yong; Kim, Bong Ki

    1987-01-01

    With Development of Computed Tomography, detection of the Hepatocellular Carcinoma are easily performed and frequently used in the world. During 15 months, from December 1985 to February 1987, 59 patients with hepatocellular carcinoma were evaluated with computed tomography in department of radiology at Wallace Memorial Baptist Hospital. The results were as follow: 1. The most prevalent age group was 5th to 7th decades, male to female ratio was 4.9:1. 2. Classification with incidence of computed tomographic appearance of the hepatocellular carcinoma were solitary type 28 cases (48%), multinodular type 24 cases (40%), and diffuse type 7 cases (12%), Association with liver cirrhosis was noted in 22 cases (38%). 3. Inhomogenous internal consistency of hepatocellular carcinoma due to central necrosis were 35 cases (60%). Portal vein invasion by hepatocellular carcinoma was noted in 15 cases (25%), and particularly most common in diffuse type 4 cases (55%). 4. On precontrast scan, all hepatocellular carcinoma were seen as area of low density except for 3 cases(0.5%) of near isodensity which turned out to be remarkable low density on postcontrast scan. 5. In solitary type, posterior segment of right lobe was most common site of involvement 12 cases (43%). In diffuse type, bilobar involvement was most common, 6 cases (85%)

  19. Techniques of noninvasive optical tomographic imaging

    Science.gov (United States)

    Rosen, Joseph; Abookasis, David; Gokhler, Mark

    2006-01-01

    Recently invented methods of optical tomographic imaging through scattering and absorbing media are presented. In one method, the three-dimensional structure of an object hidden between two biological tissues is recovered from many noisy speckle pictures obtained on the output of a multi-channeled optical imaging system. Objects are recovered from many speckled images observed by a digital camera through two stereoscopic microlens arrays. Each microlens in each array generates a speckle image of the object buried between the layers. In the computer each image is Fourier transformed jointly with an image of the speckled point-like source captured under the same conditions. A set of the squared magnitudes of the Fourier-transformed pictures is accumulated to form a single average picture. This final picture is again Fourier transformed, resulting in the three-dimensional reconstruction of the hidden object. In the other method, the effect of spatial longitudinal coherence is used for imaging through an absorbing layer with different thickness, or different index of refraction, along the layer. The technique is based on synthesis of multiple peak spatial degree of coherence. This degree of coherence enables us to scan simultaneously different sample points on different altitudes, and thus decreases the acquisition time. The same multi peak degree of coherence is also used for imaging through the absorbing layer. Our entire experiments are performed with a quasi-monochromatic light source. Therefore problems of dispersion and inhomogeneous absorption are avoided.

  20. Computer tomographic imaging of rabbit bulbourethral glands

    International Nuclear Information System (INIS)

    Dimitrov, R.

    2010-01-01

    The aim of the study was to utilize the obtained data for differentiation of normal and pathologically altered bulbourethral glands in rabbits with regard to using this animal species as a model for studying diseases in this organ in humans. MATERIAL AND METHODS: Ten sexually mature healthy male white New Zealand rabbits, 12 months old, weighed 2.8−3.2 kg were investigated. The animals were anesthetized. Scans were done at 2 mm intervals and the image reconstruction was three-dimensional. RESULTS: Rabbit bulbourethral glands were observed as a transversely oval homogeneous, relatively hyperdense structure against the surrounding soft tissues. They are visualized in the transverse cut of the pelvic outlet in the plane through the cranial part of cg2, the body of ischium, cranially to tuber ischiadicum and dorsally to the caudal part of symphysis pubis –sciatic arch. The glandular margins are adequately distinguished from the adjacent soft tissue structures. The density of the rabbit bulbourethral glands was similar to this of the soft tissues. CONCLUSION: The data obtained by the computed tomographic imaging of the rabbit bulbourethral glands could be used as an anatomical reference in the diagnosis and interpretation of imaging findings of various pathological states of the gland in this species, as well as in utilization of the rabbit as an animal model for studying diseases of this organ in humans, particularly diverticula, stenosis, lithiasis and valves

  1. A tomographic approach to intravenous coronary arteriography

    International Nuclear Information System (INIS)

    Ritman, E.L.; Bove, A.A.

    1986-01-01

    Coronary artery anatomy can be visualized using high speed, volume scanning X-ray CT. A single scan during a bolus injection of contrast medium provides image data for display of all angles of view of the opacified coronary arterial tree. Due to the tomographic nature of volume image data the superposition of contrast filled cardiac chambers, such as would occur in the levophase of an intravenous injection of contrast agent, can be eliminated. Data are presented which support these statements. The Dynamic Spatial Reconstructor (DSR) was used to scan a life-like radiologic phantom of an adult human thorax in which the left atrial and ventricular chambers and the major epicardial coronary arteries were opacified so as to simulate the levophase of an intravenous injection of contrast agent. A catheter filled with diluted contrast agent and with regions of luminal narrowing (i.e. 'stenoses') was advanced along a tract equivalent to a right ventricular catheterization. Ease of visualization of the catheter 'stenoses' and the accuracy with which they can be measured are presented. (Auth.)

  2. Comparison among tomographic reconstruction with limited data

    International Nuclear Information System (INIS)

    Oliveira, Eric F.; Dantas, Carlos C.; Vasconcelos, Daniel A.A.; Cadiz, Luis F.; Melo, Silvio B.

    2011-01-01

    Nowadays there is a continuing interest in applying computed tomography (CT) techniques in non-destructive testing and inspection of many industrial products. These applications of CT usually require a differentiated analysis when there are strong limitations in acquiring a sufficiently large amount of projection data. The use of a low number of tomographic data normally degrades the quality of the reconstructed image, highlighting the formation of artifacts and noise. This work investigates the reconstruction methods most commonly used (FBP, ART, SIRT, MART, SMART) and shows the performance of each one in this limited scenario. For this purpose, all methods were implemented and tested with a phantom of uniform density with well-known distribution, with measures of transmission of gamma radiation in a first generation CT scanner. The phantom is a concentric stainless steel tube coupled with a half - cylinder of aluminum. The measurements were made with an highest root mean square error, with the formation of visible artifacts. The artifacts are diminished but still visible in the ART and SIRT techniques, and the best performance was observed with the techniques MART and SMART. The technical superiority of these multiplicative methods is clearly seen in the reconstructed image quality, endorsing their application to situations of limited input data. (author)

  3. Computed tomographic findings of intracerebral cysticercosis

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Jin Kyo; Lee, Sun Wha; Kim, Ho Kyun; Ahn, Chi Yul [School of Medicine, Kyung-Hee University, Seoul (Korea, Republic of)

    1980-12-15

    Cysticercosis is a parasitic disease in which man serves as the intermediate host of Taenia Solium, the pork tapeworm. The computed tomographic findings of 25 cases of intracerebral cysticercosis proven by pathologic and/or clinical findings during past 2 years were analysed. The results were as follows; 1. The sex was 19 males and 6 females, and 56 percent of the patients were seen in fourth and fifth decades. The most common symptom was epilepsy (72%). 2. The C. T. findings in precontrast study were varied; such as ill defined low density (48%), cystic low density (20%), dilated ventricles (20%), ill defined low density with isodense nodule (18%), cystic low density with isodense mural nodule (12%) and calcification (8%). 3. The areas of involvement were 20 cases (80%) of parenchymal form, 3 cases (12%) of ventricular form and 2 cases (8%) of mixed form. 4. The contrast-enhanced 13 cases were 5 nodular, 5 ring or rim-like and 3 mixed type enhancements, while 12 cases were not enhanced. 5. C.T. scan demonstrated more precise location and extents of cerebral cysticercosis, especially in parenchymal form. It was considered to be important in determination of surgical feasibility and its approach.

  4. Microscopic dynamical Casimir effect

    Science.gov (United States)

    Souza, Reinaldo de Melo e.; Impens, François; Neto, Paulo A. Maia

    2018-03-01

    We consider an atom in its ground state undergoing a nonrelativistic oscillation in free space. The interaction with the electromagnetic quantum vacuum leads to two effects to leading order in perturbation theory. When the mechanical frequency is larger than the atomic transition frequency, the dominant effect is the motion-induced transition to an excited state with the emission of a photon carrying the excess energy. We compute the angular distribution of emitted photons and the excitation rate. On the other hand, when the mechanical frequency is smaller than the transition frequency, the leading-order effect is the parametric emission of photon pairs, which constitutes the microscopic counterpart of the dynamical Casimir effect. We discuss the properties of the microscopic dynamical Casimir effect and build a connection with the photon production by an oscillating macroscopic metallic mirror.

  5. Microscopic approach to polaritons

    DEFF Research Database (Denmark)

    Skettrup, Torben

    1981-01-01

    The interaction between excitons and light has been investigated in detail. The perturbational approach turns out to be invalid. However, an exact solution can be obtained directly from the Schrödinger equation for a fixed light field. This solution corresponds to a nonlinear optical response...... contrary to experimental experience. In order to remove this absurdity the semiclassical approach must be abandoned and the electromagnetic field quantized. A simple microscopic polariton model is then derived. From this the wave function for the interacting exciton-photon complex is obtained...... of light of the crystal. The introduction of damping smears out the excitonic spectra. The wave function of the polariton, however, turns out to be very independent of damping up to large damping values. Finally, this simplified microscopic polariton model is compared with the exact solutions obtained...

  6. Ion photon emission microscope

    Science.gov (United States)

    Doyle, Barney L.

    2003-04-22

    An ion beam analysis system that creates microscopic multidimensional image maps of the effects of high energy ions from an unfocussed source upon a sample by correlating the exact entry point of an ion into a sample by projection imaging of the ion-induced photons emitted at that point with a signal from a detector that measures the interaction of that ion within the sample. The emitted photons are collected in the lens system of a conventional optical microscope, and projected on the image plane of a high resolution single photon position sensitive detector. Position signals from this photon detector are then correlated in time with electrical effects, including the malfunction of digital circuits, detected within the sample that were caused by the individual ion that created these photons initially.

  7. Neuromorphic Data Microscope

    Energy Technology Data Exchange (ETDEWEB)

    Naegle, John H.; Suppona, Roger A.; Aimone, James Bradley; James, Conrad D.; Follett, David R.; Townsend, Duncan C.M.; Follett, Pamela L.; Karpman, Gabe D.

    2017-08-01

    In 2016, Lewis Rhodes Labs, (LRL), shipped the first commercially viable Neuromorphic Processing Unit, (NPU), branded as a Neuromorphic Data Microscope (NDM). This product leverages architectural mechanisms derived from the sensory cortex of the human brain to efficiently implement pattern matching. LRL and Sandia National Labs have optimized this product for streaming analytics, and demonstrated a 1,000x power per operation reduction in an FPGA format. When reduced to an ASIC, the efficiency will improve to 1,000,000x. Additionally, the neuromorphic nature of the device gives it powerful computational attributes that are counterintuitive to those schooled in traditional von Neumann architectures. The Neuromorphic Data Microscope is the first of a broad class of brain-inspired, time domain processors that will profoundly alter the functionality and economics of data processing.

  8. Color Laser Microscope

    Science.gov (United States)

    Awamura, D.; Ode, T.; Yonezawa, M.

    1987-04-01

    A color laser microscope utilizing a new color laser imaging system has been developed for the visual inspection of semiconductors. The light source, produced by three lasers (Red; He-Ne, Green; Ar, Blue; He-Cd), is deflected horizontally by an AOD (Acoustic Optical Deflector) and vertically by a vibration mirror. The laser beam is focused in a small spot which is scanned over the sample at high speed. The light reflected back from the sample is reformed to contain linear information by returning to the original vibration mirror. The linear light is guided to the CCD image sensor where it is converted into a video signal. Individual CCD image sensors are used for each of the three R, G, or B color image signals. The confocal optical system with its laser light source yields a color TV monitor image with no flaring and a much sharper resolution than that of the conventional optical microscope. The AOD makes possible a high speed laser scan and a NTSC or PAL TV video signal is produced in real time without any video memory. Since the light source is composed of R, G, and B laser beams, color separation superior to that of white light illumination is achieved. Because of the photometric linearity of the image detector, the R, G, and B outputs of the system are most suitably used for hue analysis. The CCD linear image sensors in the optical system produce no geometrical distortion, and good color registration is available principally. The output signal can be used for high accuracy line width measuring. The many features of the color laser microscope make it ideally suited for the visual inspection of semiconductor processing. A number of these systems have already been installed in such a capacity. The Color Laser Microscope can also be a very useful tool for the fields of material engineering and biotechnology.

  9. Virtual pinhole confocal microscope

    Energy Technology Data Exchange (ETDEWEB)

    George, J.S.; Rector, D.M.; Ranken, D.M. [Los Alamos National Lab., NM (United States). Biophysics Group; Peterson, B. [SciLearn Inc. (United States); Kesteron, J. [VayTech Inc. (United States)

    1999-06-01

    Scanned confocal microscopes enhance imaging capabilities, providing improved contrast and image resolution in 3-D, but existing systems have significant technical shortcomings and are expensive. Researchers at Los Alamos National Laboratory have developed a novel approach--virtual pinhole confocal microscopy--that uses state of the art illumination, detection, and data processing technologies to produce an imager with a number of advantages: reduced cost, faster imaging, improved efficiency and sensitivity, improved reliability and much greater flexibility. Work at Los Alamos demonstrated proof of principle; prototype hardware and software have been used to demonstrate technical feasibility of several implementation strategies. The system uses high performance illumination, patterned in time and space. The authors have built functional confocal imagers using video display technologies (LCD or DLP) and novel scanner based on a micro-lens array. They have developed a prototype system for high performance data acquisition and processing, designed to support realtime confocal imaging. They have developed algorithms to reconstruct confocal images from a time series of spatially sub-sampled images; software development remains an area of active development. These advances allow the collection of high quality confocal images (in fluorescence, reflectance and transmission modes) with equipment that can inexpensively retrofit to existing microscopes. Planned future extensions to these technologies will significantly enhance capabilities for microscopic imaging in a variety of applications, including confocal endoscopy, and confocal spectral imaging.

  10. Thermal Lens Microscope

    Science.gov (United States)

    Uchiyama, Kenji; Hibara, Akihide; Kimura, Hiroko; Sawada, Tsuguo; Kitamori, Takehiko

    2000-09-01

    We developed a novel laser microscope based on the thermal lens effect induced by a coaxial beam comprised of excitation and probe beams. The signal generation mechanism was confirmed to be an authentic thermal lens effect from the measurement of signal and phase dependences on optical configurations between the sample and the probe beam focus, and therefore, the thermal lens effect theory could be applied. Two-point spatial resolution was determined by the spot size of the excitation beam, not by the thermal diffusion length. Sensitivity was quite high, and the detection ability, evaluated using a submicron microparticle containing dye molecules, was 0.8 zmol/μm2, hence a distribution image of trace chemical species could be obtained quantitatively. In addition, analytes are not restricted to fluorescent species, therefore, the thermal lens microscope is a promising analytical microscope. A two-dimensional image of a histamine molecule distribution, which was produced in mast cells at the femtomole level in a human nasal mucous polyp, was obtained.

  11. Q: How do Microscopes Work?

    Science.gov (United States)

    Zimov, Sarah

    2004-01-01

    Microscopes allow scientists to examine everyday objects in extraordinary ways. They provide high-resolution images that show objects in fine detail. This brief article describes the many types of microscopes and how they are used in different scientific venues.

  12. Neutron microscope with refractive wedge

    International Nuclear Information System (INIS)

    Masalovich, S.V.

    1990-01-01

    A possibility of applying a refractive element in a mirror-neutron microscope using ultracold neutrons to reduce neutron aberrations is considered. Application of a refractive element in a neutron microscope with horizontal optical axis is studied. A scheme of neutron microscope with a refractive wedge is presented, evaluation of quartz wedge parameters is made. It is stressed that application of refractive elements in neutron microscopes facilitates aberration reduction in neutron-optical systems

  13. Tomographic techniques for safeguards measurements of nuclear fuel assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Lundqvist Saleh, Tobias

    2007-10-15

    Nuclear power is currently experiencing increased interest over the world. New nuclear reactors are being built and techniques for taking care of the nuclear waste are being developed. This development puts new demands and standards to safeguards, i.e. the international efforts for ensuring the non-proliferation of nuclear weapons. New measuring techniques and devices are continuously being developed for enhancing the ability to detect diversion of fissile material. In this thesis, tomographic techniques for application in safeguards are presented. Tomographic techniques can non-destructively provide information of the inner parts of an object and may thus be used to control that no material is missing from a nuclear fuel assembly. When using the tomographic technique described in this thesis, the radiation field around a fuel assembly is first recorded. In a second step, the internal source distribution is mathematically reconstructed based on the recorded data. In this work, a procedure for tomographic safeguards measurements is suggested and the design of a tomographic measuring device is presented. Two reconstruction algorithms have been specially developed and evaluated for the application on nuclear fuel; one algorithm for image reconstruction and one for reconstructing conclusive data on the individual fuel rod level. The combined use of the two algorithms is suggested. The applicability for detecting individual removed or replaced rods has been demonstrated, based on experimental data

  14. Combining ART and FBP for improved fidelity of tomographic BOS

    Science.gov (United States)

    Hartmann, Ulrich; Seume, Joerg R.

    2016-09-01

    Engine component defects along the hot-gas path (HGP) of jet engines influence the density distribution of the flow, and thus result in characteristic patterns in the exhaust jet. These characteristic patterns can be reconstructed with the optical background-oriented schlieren (BOS) method in a tomographic set-up, which in turn allows the identification of defects inside the engine through an exhaust jet analysis. The quality of the tomographic reconstruction strongly influences how easily defects can be detected inside the jet engine. In particular, the presence of high gradients in the reconstruction area has a strong impact on the reconstruction quality. An algebraic reconstruction algorithm (ART) is implemented and compared to a filtered-back projection (FBP) algorithm in terms of the capability of performing high-gradient tomographic BOS reconstructions. A combination of both algorithms is presented which significantly improves the reconstruction quality of high-gradient tomographic BOS in terms of artifact reduction. The combination of both algorithms is applied to both synthetic and real measurement data in this paper, in order to show possible applications and the achievable improvement of high-gradient tomographic BOS reconstructions.

  15. Atomic Force Microscope

    Energy Technology Data Exchange (ETDEWEB)

    Day, R.D.; Russell, P.E.

    1988-12-01

    The Atomic Force Microscope (AFM) is a recently developed instrument that has achieved atomic resolution imaging of both conducting and non- conducting surfaces. Because the AFM is in the early stages of development, and because of the difficulty of building the instrument, it is currently in use in fewer than ten laboratories worldwide. It promises to be a valuable tool for obtaining information about engineering surfaces and aiding the .study of precision fabrication processes. This paper gives an overview of AFM technology and presents plans to build an instrument designed to look at engineering surfaces.

  16. Solid state optical microscope

    Science.gov (United States)

    Young, Ian T.

    1983-01-01

    A solid state optical microscope wherein wide-field and high-resolution images of an object are produced at a rapid rate by utilizing conventional optics with a charge-coupled photodiode array. A galvanometer scanning mirror, for scanning in one of two orthogonal directions is provided, while the charge-coupled photodiode array scans in the other orthogonal direction. Illumination light from the object is incident upon the photodiodes, creating packets of electrons (signals) which are representative of the illuminated object. The signals are then processed, stored in a memory, and finally displayed as a video signal.

  17. Photography with a Microscope

    Science.gov (United States)

    Rost, Fred; Oldfield, Ron

    2000-03-01

    This beautifully illustrated book describes the methods used to record images viewed through a microscope. The text describes the principles and practices of photomicrography, and is written for all who take photomicrographs, beginners and/or experienced practitioners. The authors describe techniques that may be applied to many disciplines for teaching, research, archives, or pleasure. The book includes chapters on standard photography, modern digital techniques, methods for improving contrast, and a short chapter on drawing. In addition to its value as a work of reference, the authors' clear, didactic style makes this book suitable as a textbook for courses in photomicrography and/or elementary light microscopy.

  18. Electron microscope phase enhancement

    Science.gov (United States)

    Jin, Jian; Glaeser, Robert M.

    2010-06-15

    A microfabricated electron phase shift element is used for modifying the phase characteristics of an electron beam passing though its center aperture, while not affecting the more divergent portion of an incident beam to selectively provide a ninety-degree phase shift to the unscattered beam in the back focal plan of the objective lens, in order to realize Zernike-type, in-focus phase contrast in an electron microscope. One application of the element is to increase the contrast of an electron microscope for viewing weakly scattering samples while in focus. Typical weakly scattering samples include biological samples such as macromolecules, or perhaps cells. Preliminary experimental images demonstrate that these devices do apply a ninety degree phase shift as expected. Electrostatic calculations have been used to determine that fringing fields in the region of the scattered electron beams will cause a negligible phase shift as long as the ratio of electrode length to the transverse feature-size aperture is about 5:1. Calculations are underway to determine the feasibility of aspect smaller aspect ratios of about 3:1 and about 2:1.

  19. Forensic Scanning Electron Microscope

    Science.gov (United States)

    Keeley, R. H.

    1983-03-01

    The scanning electron microscope equipped with an x-ray spectrometer is a versatile instrument which has many uses in the investigation of crime and preparation of scientific evidence for the courts. Major applications include microscopy and analysis of very small fragments of paint, glass and other materials which may link an individual with a scene of crime, identification of firearms residues and examination of questioned documents. Although simultaneous observation and chemical analysis of the sample is the most important feature of the instrument, other modes of operation such as cathodoluminescence spectrometry, backscattered electron imaging and direct x-ray excitation are also exploited. Marks on two bullets or cartridge cases can be compared directly by sequential scanning with a single beam or electronic linkage of two instruments. Particles of primer residue deposited on the skin and clothing when a gun is fired can be collected on adhesive tape and identified by their morphology and elemental composition. It is also possible to differentiate between the primer residues of different types of ammunition. Bullets may be identified from the small fragments left behind as they pass through the body tissues. In the examination of questioned documents the scanning electron microscope is used to establish the order in which two intersecting ink lines were written and to detect traces of chemical markers added to the security inks on official documents.

  20. Correction of ring artifacts in X-ray tomographic images

    DEFF Research Database (Denmark)

    Lyckegaard, Allan; Johnson, G.; Tafforeau, P.

    2011-01-01

    Ring artifacts are systematic intensity distortions located on concentric circles in reconstructed tomographic X-ray images. When using X-ray tomography to study for instance low-contrast grain boundaries in metals it is crucial to correct for the ring artifacts in the images as they may have...... are separable. The method is implemented in Matlab, it works with very little user interaction and may run in parallel on a cluster if applied to a whole stack of images. The strength and robustness of the method implemented will be demonstrated on three tomographic X-ray data sets: a mono-phase β...... the same intensity level as the grain boundaries and thus make it impossible to perform grain segmentation. This paper describes an implementation of a method for correcting the ring artifacts in tomographic X-ray images of simple objects such as metal samples where the object and the background...

  1. A SPICE synthetic dataset to benchmark global tomographic methods

    Science.gov (United States)

    Qin, Y.; Capdeville, Y.; Maupin, V.; Montagner, J.

    2005-12-01

    The different existing global tomographic methods result in different models of the Earth. Within SPICE (Seismic wave Propagation and Imaging in Complex media: a European network), we have decided to perform a benchmark experiment of global tomographic techniques. A global model has been constructed. It includes 3D heterogeneities in velocity, anisotropy and attenuation, as well as topography of discontinuities. Simplified versions of the model will also be used. Synthetic seismograms will be generated at low frequency by the Spectral Element Method, for a realistic distribution of sources and stations. The synthetic seismograms will be made available to the scientific community at the SPICE website www.spice-rtn.org. Any group wishing to test his tomographic algorithm is encouraged to download the synthetic data.

  2. A tomograph VMEbus parallel processing data acquisition system

    International Nuclear Information System (INIS)

    Wilkinson, N.A.; Rogers, J.G.; Atkins, M.S.

    1989-01-01

    This paper describes a VME based data acquisition system suitable for the development of Positron Volume Imaging tomographs which use 3-D data for improved image resolution over slice-oriented tomographs. the data acquisition must be flexible enough to accommodate several 3-D reconstruction algorithms; hence, a software-based system is most suitable. Furthermore, because of the increased dimensions and resolution of volume imaging tomographs, the raw data event rate is greater than that of slice-oriented machines. These dual requirements are met by our data acquisition system. Flexibility is achieved through an array of processors connected over a VMEbus, operating asynchronously and in parallel. High raw data throughput is achieved using a dedicated high speed data transfer device available for the VMEbus. The device can attain a raw data rate of 2.5 million coincidence events per second for raw events which are 64 bits wide

  3. A piezoelectric goniometer inside a transmission electron microscope goniometer.

    Science.gov (United States)

    Guan, Wei; Lockwood, Aiden; Inkson, Beverley J; Möbus, Günter

    2011-10-01

    Piezoelectric nanoactuators, which can provide extremely stable and reproducible positioning, are rapidly becoming the dominant means for position control in transmission electron microscopy. Here we present a second-generation miniature goniometric nanomanipulation system, which is fully piezo-actuated with ultrafine step size for translation and rotation, programmable, and can be fitted inside a hollowed standard specimen holder for a transmission electron microscope (TEM). The movement range of this miniaturized drive is composed of seven degrees of freedom: three fine translational movements (X, Y, and Z axes), three coarse translational movements along all three axes, and one rotational movement around the X-axis with an integrated angular sensor providing absolute rotation feedback. The new piezoelectric system independently operates as a goniometer inside the TEM goniometer. In situ experiments, such as tomographic tilt without missing wedge and differential tilt between two specimens, are demonstrated.

  4. Radiographic and tomographic study of the elbow joint in dogs

    International Nuclear Information System (INIS)

    Sendyk-Grunkraut, Alessandra; Martin, Claudia M.; Souza, Alexandre N.A.; Patricio, Geni Cristina F.; Lorigados, Carla A.B.; Matera, Julia M.; Fonseca-Pinto, Ana C.B.C.

    2017-01-01

    Elbow dysplasia disease includes an united anconeal process, fragmented medial coronoid process, osteochondrosis of humeral trochlea, articular incongruity and degenerative joint disease. The aim of this study was to present detailed morphologic and morphometric aspects of the elbow joint in dog in clinical and correlate with radiographic and tomographic (CT) exam. Inter-observer variation for articular incongruity measurements by CT, comparative analysis in the radiographic exam, angle in ulnar notch and its comparative analysis between radiographic and tomographic agreement examination in 44 elbow of dogs with different ages were evaluated. The statistics analyses included the kappa coefficient and interclass correlation and Fischer's test and McNemar's test. It was evidenced that individual performance of each radiographic incidence had poor agreement with the tomographic exam, suggesting that the accomplishment of more than two radiograph views are needed. There was no agreement between the three evaluators in the ulnar notch angle at radiographic and tomographic exams. However, there was good/moderate agreement for articular incongruity measurement in the sagittal plane between evaluators. It was possible to conclude that none of the five radiographic incidences was better than the others for radiographic analysis because each incidence had a better identification of a particular elbow compartment; measurements at the tomographic exam to evaluate radioulnar incongruity had no reproductiveness in the frontal plane, but in sagittal plan had a good/moderate agreement between observers and the angle in ulnar notch presented no repeatability at radiographic exam and no reproductiveness at tomographic exam. (author)

  5. Computerized Tomographic Study on the Paranasal Sinusitis

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Sun Kyung; Lim, Sug Young; Koh, Kwang Joon [Dept. of Oral and Maxillofacial Radiology and Institute of Oral Bio Science, College of Dentistry, Chonbuk National University, Chonju (Korea, Republic of)

    1999-08-15

    The purpose of this study was to evaluate the computed tomographic (CT) images of the paranasal sinusitis(PNS). The author examined the extent and the recurring patterns of the paranasal sinusitis and some important anatomic landmarks. The author analyzed PNS images retrospectively in 500 patients who visited Chonbuk National University Hospital between January 1996 and December 1997. The most frequently affected sinus was maxillary sinus (82.9%), followed by anterior ethmoid sinus (67.9%), posterior ethmoid sinus (48.9%), frontal sinus (42.0%) and sphenoid sinus (41.4%). The characteristic features of CT images of the sinusitis were sinus opacification (22.4%), mucoperiosteal thickening (34.3%), and polyposis (2.0%). Sinonasal inflammatory diseases were categorized into 5 patterns according to Babbel's classification. They were 1) infundibular (13.0%), 2) ostiomeatal unit (67.4%), 3)sphenoethmoidal recess (13.0%), 4) sinonasal polyposis (9.6%) and 5) unclassifiable patterns (18.0%). The incidences of contact between sinus and optic nerve were as follows ; the incidences of contact with posterior ethmoid sinus, sphenoid sinus, both posterior sinuses were 11.4%, 66.8%, 6.3%, respectively. The incidences of contact between sphenoid sinus and maxillary nerve, vidian nerve, internal carotid artery were 74.5%, 79.2%, 45.1% respectively. The incidences of pneumatization of the posterior ethmoid sinus were as follows; normal 70.6% and overriding type 29.4%. The incidences of sphenoid sinus pneumatization were as follows; normal 56.9% , rudimentary 12.5%, pterygoid recess 22.7%, anterior clinoid recess 2.7%, and both pterygoid and anterior clinoid recess 5.2%. The inflammatory sinonasal diseases were classified into five patterns using the CT of PNS, which was proven to be an excellent imaging modality providing detailed information about mucosal abnormality, pathologic patterns and the proximity of the important structures to the posterior paranasal sinuses. This

  6. Anisotropic contrast optical microscope.

    Science.gov (United States)

    Peev, D; Hofmann, T; Kananizadeh, N; Beeram, S; Rodriguez, E; Wimer, S; Rodenhausen, K B; Herzinger, C M; Kasputis, T; Pfaunmiller, E; Nguyen, A; Korlacki, R; Pannier, A; Li, Y; Schubert, E; Hage, D; Schubert, M

    2016-11-01

    An optical microscope is described that reveals contrast in the Mueller matrix images of a thin, transparent, or semi-transparent specimen located within an anisotropic object plane (anisotropic filter). The specimen changes the anisotropy of the filter and thereby produces contrast within the Mueller matrix images. Here we use an anisotropic filter composed of a semi-transparent, nanostructured thin film with sub-wavelength thickness placed within the object plane. The sample is illuminated as in common optical microscopy but the light is modulated in its polarization using combinations of linear polarizers and phase plate (compensator) to control and analyze the state of polarization. Direct generalized ellipsometry data analysis approaches permit extraction of fundamental Mueller matrix object plane images dispensing with the need of Fourier expansion methods. Generalized ellipsometry model approaches are used for quantitative image analyses. These images are obtained from sets of multiple images obtained under various polarizer, analyzer, and compensator settings. Up to 16 independent Mueller matrix images can be obtained, while our current setup is limited to 11 images normalized by the unpolarized intensity. We demonstrate the anisotropic contrast optical microscope by measuring lithographically defined micro-patterned anisotropic filters, and we quantify the adsorption of an organic self-assembled monolayer film onto the anisotropic filter. Comparison with an isotropic glass slide demonstrates the image enhancement obtained by our method over microscopy without the use of an anisotropic filter. In our current instrument, we estimate the limit of detection for organic volumetric mass within the object plane of ≈49 fg within ≈7 × 7 μm 2 object surface area. Compared to a quartz crystal microbalance with dissipation instrumentation, where contemporary limits require a total load of ≈500 pg for detection, the instrumentation demonstrated here improves

  7. Biomedical Optoacoustic Tomograph Based on a Cylindrical Focusing PVDF Antenna

    Science.gov (United States)

    Subochev, P. V.; Postnikova, A. S.; Koval'chuk, A. V.; Turchin, I. V.

    2017-08-01

    We developed an optoacoustic tomograph with hand-held probe designed for optoacoustic imaging of biological tissues. The hand-held probe consists of a fiber-optic bundle for delivery of pulsed laser radiation to the studied object and a cylindrical focusing 64-element antenna for the detection of optoacoustic pulses. The capabilities of the tomograph to visualize the model blood vessels were studied experimentally using electronic and electronic-mechanical scanning. The achieved axial/lateral spatial resolution is 200/400 μm, the imaging depth is 18 mm, and the maximum B-scan acquisition rate is 10 Hz.

  8. Optical tomograph optimized for tumor detection inside highly absorbent organs

    Science.gov (United States)

    Boutet, Jérôme; Koenig, Anne; Hervé, Lionel; Berger, Michel; Dinten, Jean-Marc; Josserand, Véronique; Coll, Jean-Luc

    2011-05-01

    This paper presents a tomograph for small animal fluorescence imaging. The compact and cost-effective system described in this article was designed to address the problem of tumor detection inside highly absorbent heterogeneous organs, such as lungs. To validate the tomograph's ability to detect cancerous nodules inside lungs, in vivo tumor growth was studied on seven cancerous mice bearing murine mammary tumors marked with Alexa Fluor 700. They were successively imaged 10, 12, and 14 days after the primary tumor implantation. The fluorescence maps were compared over this time period. As expected, the reconstructed fluorescence increases with the tumor growth stage.

  9. Microscopic entropy and nonlocality

    International Nuclear Information System (INIS)

    Karpov, E.; Ordonets, G.; Petroskij, T.; Prigozhin, I.

    2003-01-01

    We have obtained a microscopic expression for entropy in terms of H function based on nonunitary Λ transformation which leads from the time evolution as a unitary group to a Markovian dynamics and unifies the reversible and irreversible aspects of quantum mechanics. This requires a new representation outside the Hilbert space. In terms of H, we show the entropy production and the entropy flow during the emission and absorption of radiation by an atom. Analyzing the time inversion experiment, we emphasize the importance of pre- and postcollisional correlations, which break the symmetry between incoming and outgoing waves. We consider the angle dependence of the H function in a three-dimensional situation. A model including virtual transitions is discussed in a subsequent paper

  10. Embryos, microscopes, and society.

    Science.gov (United States)

    Maienschein, Jane

    2016-06-01

    Embryos have different meanings for different people and in different contexts. Seen under the microscope, the biological embryo starts out as one cell and then becomes a bunch of cells. Gradually these divide and differentiate to make up the embryo, which in humans becomes a fetus at eight weeks, and then eventually a baby. At least, that happens in those cases that carry through normally and successfully. Yet a popular public perception imagines the embryo as already a little person in the very earliest stages of development, as if it were predictably to become an adult. In actuality, cells can combine, pull apart, and recombine in a variety of ways and still produce embryos, whereas most embryos never develop into adults at all. Biological embryos and popular imaginations of embryos diverge. This paper looks at some of the historical reasons for and social implications of that divergence. Copyright © 2016 The Author. Published by Elsevier Ltd.. All rights reserved.

  11. Imaging arrangement and microscope

    Science.gov (United States)

    Pertsinidis, Alexandros; Chu, Steven

    2015-12-15

    An embodiment of the present invention is an imaging arrangement that includes imaging optics, a fiducial light source, and a control system. In operation, the imaging optics separate light into first and second tight by wavelength and project the first and second light onto first and second areas within first and second detector regions, respectively. The imaging optics separate fiducial light from the fiducial light source into first and second fiducial light and project the first and second fiducial light onto third and fourth areas within the first and second detector regions, respectively. The control system adjusts alignment of the imaging optics so that the first and second fiducial light projected onto the first and second detector regions maintain relatively constant positions within the first and second detector regions, respectively. Another embodiment of the present invention is a microscope that includes the imaging arrangement.

  12. Microscopic Theory of Transconductivity

    Directory of Open Access Journals (Sweden)

    A. P. Jauho

    1998-01-01

    Full Text Available Measurements of momentum transfer between two closely spaced mesoscopic electronic systems, which couple via Coulomb interaction but where tunneling is inhibited, have proven to be a fruitful method of extracting information about interactions in mesoscopic systems. We report a fully microscopic theory for transconductivity σ12, or, equivalently, momentum transfer rate between the system constituents. Our main formal result expresses the transconductivity in terms of two fluctuation diagrams, which are topologically related, but not equivalent to, the Azlamazov-Larkin and Maki-Thompson diagrams known for superconductivity. In the present paper the magnetic field dependence of σ12 is discussed, and we find that σ12(B is strongly enhanced over its zero field value, and it displays strong features, which can be understood in terms of a competition between density-of-states and screening effects.

  13. Femtosecond photoelectron point projection microscope

    International Nuclear Information System (INIS)

    Quinonez, Erik; Handali, Jonathan; Barwick, Brett

    2013-01-01

    By utilizing a nanometer ultrafast electron source in a point projection microscope we demonstrate that images of nanoparticles with spatial resolutions of the order of 100 nanometers can be obtained. The duration of the emission process of the photoemitted electrons used to make images is shown to be of the order of 100 fs using an autocorrelation technique. The compact geometry of this photoelectron point projection microscope does not preclude its use as a simple ultrafast electron microscope, and we use simple analytic models to estimate temporal resolutions that can be expected when using it as a pump-probe ultrafast electron microscope. These models show a significant increase in temporal resolution when comparing to ultrafast electron microscopes based on conventional designs. We also model the microscopes spectroscopic abilities to capture ultrafast phenomena such as the photon induced near field effect

  14. Proper alignment of the microscope.

    Science.gov (United States)

    Rottenfusser, Rudi

    2013-01-01

    The light microscope is merely the first element of an imaging system in a research facility. Such a system may include high-speed and/or high-resolution image acquisition capabilities, confocal technologies, and super-resolution methods of various types. Yet more than ever, the proverb "garbage in-garbage out" remains a fact. Image manipulations may be used to conceal a suboptimal microscope setup, but an artifact-free image can only be obtained when the microscope is optimally aligned, both mechanically and optically. Something else is often overlooked in the quest to get the best image out of the microscope: Proper sample preparation! The microscope optics can only do its job when its design criteria are matched to the specimen or vice versa. The specimen itself, the mounting medium, the cover slip, and the type of immersion medium (if applicable) are all part of the total optical makeup. To get the best results out of a microscope, understanding the functions of all of its variable components is important. Only then one knows how to optimize these components for the intended application. Different approaches might be chosen to discuss all of the microscope's components. We decided to follow the light path which starts with the light source and ends at the camera or the eyepieces. To add more transparency to this sequence, the section up to the microscope stage was called the "Illuminating Section", to be followed by the "Imaging Section" which starts with the microscope objective. After understanding the various components, we can start "working with the microscope." To get the best resolution and contrast from the microscope, the practice of "Koehler Illumination" should be understood and followed by every serious microscopist. Step-by-step instructions as well as illustrations of the beam path in an upright and inverted microscope are included in this chapter. A few practical considerations are listed in Section 3. Copyright © 2013 Elsevier Inc. All rights

  15. Scanning Electron Microscope Analysis System

    Data.gov (United States)

    Federal Laboratory Consortium — This facility provides the capability to examine surfaces microscopically with high resolution (5 nanometers), perform micro chemical analyses of these surfaces, and...

  16. Three-dimensional phase-contrast X-ray microtomography with scanning-imaging X-ray microscope optics.

    Science.gov (United States)

    Takeuchi, Akihisa; Uesugi, Kentaro; Suzuki, Yoshio

    2013-09-01

    A three-dimensional (3D) X-ray tomographic micro-imaging system has been developed. The optical system is based on a scanning-imaging X-ray microscope (SIXM) optics, which is a hybrid system consisting of a scanning microscope optics with a one-dimensional (1D) focusing (line-focusing) device and an imaging microscope optics with a 1D objective. In the SIXM system, each 1D dataset of a two-dimensional (2D) image is recorded independently. An object is illuminated with a line-focused beam. Positional information of the region illuminated by the line-focused beam is recorded with the 1D imaging microscope optics as line-profile data. By scanning the object with the line focus, 2D image data are obtained. In the same manner as for a scanning microscope optics with a multi-pixel detector, imaging modes such as phase contrast and absorption contrast can be arbitrarily configured after the image data acquisition. By combining a tomographic scan method and the SIXM system, quantitative 3D imaging is performed. Results of a feasibility study of the SIXM for 3D imaging are shown.

  17. Design of Pre-emphasis Compensation for MR Tomograph

    Czech Academy of Sciences Publication Activity Database

    Gescheidtová, E.; Kubásek, J.; Smékal, Z.; Bartušek, Karel

    2008-01-01

    Roč. 45, č. 1 (2008), s. 161-173 ISSN 1738-6438 R&D Projects: GA ČR(CZ) GA102/07/0389 Institutional research plan: CEZ:AV0Z20650511 Keywords : pre-emphasis compensation * MR tomograph Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  18. Computerized tomographic findings in children with head trauma in ...

    African Journals Online (AJOL)

    Objective: To describe the computerized tomographic findings in children with head trauma who presented at the University of Benin Teaching Hospital, Benin City, Nigeria. Methods: It is a retrospective review of patients aged 0 – 15 years with suspected intracranial injury (ICI) following head trauma, who presented for CT ...

  19. Tomographic reconstruction of internal wave patterns in a paraboloid

    NARCIS (Netherlands)

    Hazewinkel, J.; Maas, L.R.M.; Dalziel, S.B.

    2011-01-01

    Using tomographic synthetic schlieren, we are able to reconstruct the three-dimensional density field of internal waves. In this study, the waves are radiating from an oscillating sphere positioned eccentrically at the surface of a paraboloidal domain filled with a uniformly stratified fluid. We

  20. Gunshot injuries to the maxillofacial region: computed tomographic ...

    African Journals Online (AJOL)

    OBJECTIVE: To evaluate Computed Tomographic findings in patients with gunshot injury (GSI) to the maxillofacial region. MATERIALS AND METHODS: A retrospective cohort study of patients who had Computed Tomography (CT) scanning done for GSI to the maxillofacial region at the University of Benin Teaching ...

  1. Application of tomographic particle image velocimetry to complex (dusty) plasmas

    International Nuclear Information System (INIS)

    Williams, Jeremiah

    2011-01-01

    Over the past decade, particle image velocimetry (PIV) techniques have been used to obtain detailed measurements of the thermal and transport properties of weakly-coupled dusty plasmas. This paper reports on the application of an extension of these techniques, tomographic PIV (tom-PIV), which provides an instantaneous volumetric measurement of the particle transport.

  2. Dense velocity reconstruction from tomographic PTV with material derivatives

    NARCIS (Netherlands)

    Schneiders, J.F.G.; Scarano, F.

    2016-01-01

    A method is proposed to reconstruct the instantaneous velocity field from time-resolved volumetric particle tracking velocimetry (PTV, e.g., 3D-PTV, tomographic PTV and Shake-the-Box), employing both the instantaneous velocity and the velocity material derivative of the sparse tracer particles. The

  3. A new ionospheric tomographic algorithm–constrained multiplicative ...

    Indian Academy of Sciences (India)

    For the limitation of the conventional multiplicative algebraic reconstruction technique (MART), a constrained MART (CMART) is proposed in this paper. In the new tomographic algorithm, a popular two-dimensional multi-point finite difference approximation of the second order Laplacian operator is used to smooth the ...

  4. Unique determination of structure and velocity by 3-D tomographic ...

    African Journals Online (AJOL)

    A subsequent 2-D Prestack depth migration based on the Kirchhoff method utilizing the velocity field obtained from the tomographic inversion extracts more information from the data and gives a clear picture of the subsurface. The superiority of the simultaneous inversion of the reflected and refracted waves to that of ...

  5. Computed tomographic findings in manifesting carriers of Duchenne muscular dystrophy

    NARCIS (Netherlands)

    de Visser, M.; Verbeeten, B.

    1985-01-01

    Clinical and computed tomographic (CT) findings in 3 manifesting carriers of Duchenne muscular dystrophy are reported. CT proved to be an important adjunct to the clinical examination: in all our 3 cases a decrease in density was found in various non-paretic muscles

  6. Temporal evaluation of computed tomographic scans at a Level 1 ...

    African Journals Online (AJOL)

    Temporal evaluation of computed tomographic scans at a Level 1 trauma department in a central South African hospital. ... Method: Relevant categorical data were collected from the trauma patient register and radiological information system (RIS) from 01 February 2013 to 31 January 2014. A population of 1107 trauma ...

  7. Photon scanning tunneling microscope in combination with a force microscope

    NARCIS (Netherlands)

    Moers, M.H.P.; Moers, M.H.P.; Tack, R.G.; van Hulst, N.F.; Bölger, B.; Bölger, B.

    1994-01-01

    The simultaneous operation of a photon scanning tunneling microscope with an atomic force microscope is presented. The use of standard atomic force silicon nitride cantilevers as near-field optical probes offers the possibility to combine the two methods. Vertical forces and torsion are detected

  8. The Latest in Handheld Microscopes

    Science.gov (United States)

    Wighting, Mervyn J.; Lucking, Robert A.; Christmann, Edwin P.

    2004-01-01

    Around 1590, Zacharias Jansenn of Holland invented the microscope. Jansenn, an eyeglass maker by trade, experimented with lenses and discovered that things appeared closer with combinations of lenses. Over the past 400 years, several refinements to microscopes have occurred, making it possible to magnify objects between 200 and 1,500 times their…

  9. Midfield microscope : Exploring the extraordinary

    NARCIS (Netherlands)

    Docter, M.W.

    2008-01-01

    In this thesis the development of the midfield microscope is presented. This is a microscope in which the extraordinary transmission (EOT) through sub-wavelength hole-arrays is applied. Before trying to combine microscopy and EOT, we look at them separately. In chapter 1 an overview is given of the

  10. Full-field optical coherence tomography using immersion Mirau interference microscope.

    Science.gov (United States)

    Lu, Sheng-Hua; Chang, Chia-Jung; Kao, Ching-Fen

    2013-06-20

    In this study, an immersion Mirau interference microscope was developed for full-field optical coherence tomography (FFOCT). Both the reference and measuring arms of the Mirau interferometer were filled with water to prevent the problems associated with imaging a sample in air with conventional FFOCT systems. The almost-common path interferometer makes the tomographic system less sensitive to environmental disturbances. En face OCT images at various depths were obtained with phase-shifting interferometry and Hariharan algorithm. This immersion interferometric method improves depth and quality in three-dimensional OCT imaging of scattering tissue.

  11. Tomographic findings of acute pulmonary toxoplasmosis in immunocompetent patients.

    Science.gov (United States)

    de Souza Giassi, Karina; Costa, Andre Nathan; Apanavicius, Andre; Teixeira, Fernando Bin; Fernandes, Caio Julio Cesar; Helito, Alfredo Salim; Kairalla, Ronaldo Adib

    2014-11-25

    Toxoplasmosis is one of the most common human zoonosis, and is generally benign in most of the individuals. Pulmonary involvement is common in immunocompromised subjects, but very rare in immunocompetents and there are scarce reports of tomographic findings in the literature. The aim of the study is to describe three immunocompetent patients diagnosed with acute pulmonary toxoplasmosis and their respective thoracic tomographic findings. Acute toxoplasmosis was diagnosed according to the results of serological tests suggestive of recent primary infection and the absence of an alternative etiology. From 2009 to 2013, three patients were diagnosed with acute respiratory failure secondary to acute toxoplasmosis. The patients were two female and one male, and were 38, 56 and 36 years old. Similarly they presented a two-week febrile illness and progressive dyspnea before admission. Laboratory tests demonstrated lymphocytosis, slight changes in liver enzymes and high inflammatory markers. Tomographic findings were bilateral smooth septal and peribronchovascular thickening (100%), ground-glass opacities (100%), atelectasis (33%), random nodules (33%), lymph node enlargement (33%) and pleural effusion (66%). All the patients improved their symptoms after treatment, and complete resolution of tomographic findings were found in the followup. These cases provide a unique description of the presentation and evolution of pulmonary tomographic manifestations of toxoplasmosis in immunocompetent patients. Toxoplasma pneumonia manifests with fever, dyspnea and a non-productive cough that may result in respiratory failure. In animal models, changes were described as interstitial pneumonitis with focal infiltrates of neutrophils that can finally evolve into a pattern of diffuse alveolar damage with focal necrosis. The tomographic findings are characterized as ground glass opacities, smooth septal and marked peribronchovascular thickening; and may mimic pulmonary congestion

  12. Cone-beam computerized tomographic, radiographic, and histologic evaluation of periapical repair in dogs' post-endodontic treatment.

    Science.gov (United States)

    de Paula-Silva, Francisco Wanderley Garcia; Santamaria, Milton; Leonardo, Mário Roberto; Consolaro, Alberto; da Silva, Léa Assed Bezerra

    2009-11-01

    To evaluate the periapical repair after root canal treatment in the teeth of dogs using CT and conventional radiography and to compare these findings with the gold standard microscopic evaluation. The animals were divided into three groups according to endodontic treatment performed: Group 1, single-visit endodontic treatment in teeth without apical periodontitis; Group 2, single-visit endodontic treatment in teeth with apical periodontitis; and Group 3, endodontic treatment in teeth with apical periodontitis using calcium hydroxide as a root canal dressing. Group 4 consisted of teeth with apical periodontitis not submitted to root canal treatment and Group 5 consisted of healthy teeth without periapical disease. Radiographic, tomographic, and microscopic evaluations were performed by blind examiners. At 180 days experimental time, CT and radiographic measurements of periapical disease were compared with the gold standard microscopic measurement using intraclass correlation coefficient. Intergroup comparisons considering different methods of periapical lesions measurement or different clinical protocols of root canal treatment were performed by Kruskal Wallis test followed by Dunn. Integrity of lamina dura, presence of radiolucent areas, and presence of root resorption were analyzed by Fisher's exact test. There was discontinuity of the lamina dura and CPD in all teeth from Groups 2, 3, and 4 evaluated by tomography and radiography 45 days after CPD induction. Radiographically, 180 days after root canal treatment, there was no periapical lesion in teeth from Groups 1 and 3, different from groups 2 and 4 (p periapical lesions presented larger mesio-distal extension if compared with radiography, both 45 days after CPD induction and 180 days after root canal treatment. At 180 days, CT measurements were closely related to microscopic results (ICC = 0.95) differently from radiographic evaluation (ICC = 0.86). CT Scan evaluation of periapical repair following root canal

  13. The head-mounted microscope.

    Science.gov (United States)

    Chen, Ting; Dailey, Seth H; Naze, Sawyer A; Jiang, Jack J

    2012-04-01

    Microsurgical equipment has greatly advanced since the inception of the microscope into the operating room. These advancements have allowed for superior surgical precision and better post-operative results. This study focuses on the use of the Leica HM500 head-mounted microscope for the operating phonosurgeon. The head-mounted microscope has an optical zoom from 2× to 9× and provides a working distance from 300 mm to 700 mm. The headpiece, with its articulated eyepieces, adjusts easily to head shape and circumference, and offers a focus function, which is either automatic or manually controlled. We performed five microlaryngoscopic operations utilizing the head-mounted microscope with successful results. By creating a more ergonomically favorable operating posture, a surgeon may be able to obtain greater precision and success in phonomicrosurgery. Phonomicrosurgery requires the precise manipulation of long-handled cantilevered instruments through the narrow bore of a laryngoscope. The head-mounted microscope shortens the working distance compared with a stand microscope, thereby increasing arm stability, which may improve surgical precision. Also, the head-mounted design permits flexibility in head position, enabling operator comfort, and delaying musculoskeletal fatigue. A head-mounted microscope decreases the working distance and provides better ergonomics in laryngoscopic microsurgery. These advances provide the potential to promote precision in phonomicrosurgery. Copyright © 2011 The American Laryngological, Rhinological, and Otological Society, Inc.

  14. Mobile microscope complex GIB-1

    International Nuclear Information System (INIS)

    Belyakov, A.V.; Gorbachev, A.N.

    2002-01-01

    To study microstructure in operating pipelines of power units a mobile microscope system is developed and successfully used. The system includes a portable microscope, a monitor, power supply and a portable computer. The monitor is used for surveying images from a video camera mounted on the microscope. The magnification on visual examination constitutes x 100 and x 500. Diameters of pipelines examined should not be less than 130 mm. Surface preparation for microstructural studies includes routine mechanical rough grinding and polishing with subsequent etching [ru

  15. Terahertz Imaging for Biomedical Applications Pattern Recognition and Tomographic Reconstruction

    CERN Document Server

    Yin, Xiaoxia; Abbott, Derek

    2012-01-01

    Terahertz Imaging for Biomedical Applications: Pattern Recognition and Tomographic Reconstruction presents the necessary algorithms needed to assist screening, diagnosis, and treatment, and these algorithms will play a critical role in the accurate detection of abnormalities present in biomedical imaging. Terahertz biomedical imaging has become an area of interest due to its ability to simultaneously acquire both image and spectral information. Terahertz imaging systems are being commercialized with an increasing number of trials performed in a biomedical setting. Terahertz tomographic imaging and detection technology contributes to the ability to identify opaque objects with clear boundaries,and would be useful to both in vivo and ex vivo environments. This book also: Introduces terahertz radiation techniques and provides a number of topical examples of signal and image processing, as well as machine learning Presents the most recent developments in an emerging field, terahertz radiation Utilizes new methods...

  16. A preliminary design study for improving performance in tomographic assays

    International Nuclear Information System (INIS)

    Estep, R.J.

    1994-03-01

    The authors recently introduced the tomographic-gamma-scanner (TGS) method for assaying transuranic (TRU) waste and special nuclear material (SNM) in 55-gal drums. The TGS combines low-resolution emission and transmission tomography to obtain attenuation-corrected images of the radionuclide distribution inside a drum. In a low-resolution tomographic assay device, it is desirable to have as flat an efficiency profile as possible. Using computer simulations, they have demonstrated that a flat response in the vertical direction can be obtained by using a diamond-shaped collimator, and that this flatness of response translates into improved assay accuracy. Similarly, they have shown that the use of a continuous-motion scan protocol reduces horizontal efficiency variations

  17. Simultaneous tomographic reconstruction and segmentation with class priors

    DEFF Research Database (Denmark)

    Romanov, Mikhail; Dahl, Anders Bjorholm; Dong, Yiqiu

    2015-01-01

    We consider tomographic imaging problems where the goal is to obtain both a reconstructed image and a corresponding segmentation. A classical approach is to first reconstruct and then segment the image; more recent approaches use a discrete tomography approach where reconstruction and segmentatio...... approach can produce better results than the classical two-step approach.......We consider tomographic imaging problems where the goal is to obtain both a reconstructed image and a corresponding segmentation. A classical approach is to first reconstruct and then segment the image; more recent approaches use a discrete tomography approach where reconstruction and segmentation...... are combined to produce a reconstruction that is identical to the segmentation. We consider instead a hybrid approach that simultaneously produces both a reconstructed image and segmentation. We incorporate priors about the desired classes of the segmentation through a Hidden Markov Measure Field Model, and we...

  18. Advances in the calibration of atom probe tomographic reconstruction

    International Nuclear Information System (INIS)

    Gault, Baptiste; Moody, Michael P.; La Fontaine, Alexandre; Stephenson, Leigh T.; Haley, Daniel; Ringer, Simon P.; Geuser, Frederic de; Tsafnat, Guy

    2009-01-01

    Modern wide field-of-view atom probes permit observation of a wide range of crystallographic features that can be used to calibrate the tomographic reconstruction of the analyzed volume. In this study, methodologies to determine values of the geometric parameters involved in the tomographic reconstruction of atom probe data sets are presented and discussed. The influence of the tip to electrode distance and specimen temperature on these parameters is explored. Significantly, their influence is demonstrated to be very limited, indicating a relatively wide regime of experimental parameters space for sound atom probe tomography (APT) experiments. These methods have been used on several specimens and material types, and the results indicate that the reconstruction parameters are specific to each specimen. Finally, it is shown how an accurate calibration of the reconstruction enables improvements to the quality and reliability of the microscopy and microanalysis capabilities of the atom probe

  19. The CDD system in computed tomographic diagnosis of diverticular disease

    International Nuclear Information System (INIS)

    Pustelnik, Daniel; Elsholtz, Fabian Henry Juergen; Hamm, Bernd; Niehues, Stefan Markus; Bojarski, Christian

    2017-01-01

    Purpose cation in computed tomographic diagnosis and briefly recapitulates its targeted advantages over preliminary systems. Primarily, application of the CDD in computed tomography diagnostics is described. Differences with respect to the categories of the older systems are pointed out on the level of each CDD type using imaging examples. The presented images are derived from our institute according to the S2k criteria. Literature was researched on PubMed. Results The CDD constitutes an improvement compared to older systems for categorizing the stages of diverticular disease. It provides more discriminatory power on the descriptive-morphological level and defines as well as differentiates more courses of the disease. Furthermore, the categories translate more directly into state-of-the-art decision-making concerning hospitalization and therapy. The CDD should be applied routinely in the computed tomographic diagnosis of diverticular disease. Typical imaging patterns are presented.

  20. A feasibility study on a tomograph for radioactive waste examination

    International Nuclear Information System (INIS)

    Montigon, J.F.

    1987-01-01

    A feasibility study on a high-energy tomograph for radioactive waste examination has been carried out by CEA/SEDFMA (Cadarache, France). After describing the scope of the research (radiation source, detector system, data processing, station mechanics), this final report deals with the work programme which has been followed and gives the results of the research. The conclusion is that such a tomograph is feasible, and its preliminary design is shown. The main points are that: - the detector material will be BGO, - the transmission of gamma rays through concrete (up to 1 625 mm thick) has been measured and a calculation code has been validated, - the radiation source will be an accelerator which has to be carefully optimized, - the system configuration has been determined and the data processors have been chosen, - the algorithms for image reconstruction have been validated through taking a tomogram on a concrete sample

  1. Computed tomographic features of fibrous dysplasia of maxillofacial region

    OpenAIRE

    Sontakke, Subodh Arun; Karjodkar, Freny R; Umarji, Hemant R

    2011-01-01

    Purpose This study was to find the computed tomographic features of fibrous dysplasia of the maxillofacial region. Materials and Methods All eight cases included in the study reported either to Government Dental College and Hospital or Nair Hospital Dental College, Mumbai between 2003 and 2009. The patients were prescribed computed tomogram in addition to conventional radiographs of maxillofacial region which were studied for characteristic features of fibrous dysplasia. The diagnosis of fibr...

  2. Predictors of Incomplete Optical Colonoscopy Using Computed Tomographic Colonography

    OpenAIRE

    Sachdeva, Reetika; Tsai, Salina D.; El Zein, Mohamad H.; Tieu, Alan A.; Abdelgelil, Ahmed; Besharati, Sepideh; Khashab, Mouen A.; Kalloo, Anthony N.; Kumbhari, Vivek

    2016-01-01

    Background/Aims: Optical colonoscopy (OC) is the primary modality for investigation of colonic pathology. Although there is data on demographic factors for incomplete OC, paucity of data exists for anatomic variables that are associated with an incomplete OC. These anatomic variables can be visualized using computed tomographic colonography (CTC). We aim to retrospectively identify variables associated with incomplete OC using CTC and develop a scoring method to predict the outcome of OC. Pat...

  3. Computed tomographic diagnosis of abdominal abscess in childhood

    International Nuclear Information System (INIS)

    Kuhn, J.P.; Berger, P.E.

    1980-01-01

    Twenty-eight children suspected clinically of having an abdominal abscess were examined by CT. Eighteen had gallium 67 citrate scans and 22 had ultrasound studies. Computed tomography was found to be the most accurate test for diagnosis and evaluation of an abscess and the computed tomographic appearance of abscess is illustrated. However, because of cost factors, radiation dose, and clinical considerations, computed tomography is not always the first modality of choice in evaluating a suspected abdominal abscess [fr

  4. A general purpose tomographic program with combined inversions

    International Nuclear Information System (INIS)

    Xu Wenbin; Dong Jiafu; Li Fanzhu

    1996-01-01

    A general tomographic program has been developed by combining the Bessel expansion with the Zernicke expansion. It is useful for studying of the magnetic island structure of the tearing mode and in reconstructing the density profiles of impurities in tokamak plasmas. This combined method have the advantages of both expansions, i.e. there will be no spurious images in the edge and it will be of high inverse precision in the center of plasma

  5. Microscopic examination of deteriorated concrete

    NARCIS (Netherlands)

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

    2010-01-01

    Concrete petrography is the integrated microscopic and mesoscale (hand specimen size) investigation of hardened concrete, that can provide information on the composition of concrete, the original relationships between the concrete's various constituents, and any changes therein, whether as a result

  6. Center of excellence: Microlaser microscope

    Science.gov (United States)

    Webb, R. H.

    This Center-of-Excellence grant has two components: development of an imaging system based on microlaser arrays forms a central project among a group of laser diagnostic and therapeutic efforts primarily funded outside the grant. In these first 8 months we have set up the Microlaser Microscope using small microlaser arrays. We have emphasized the basics of microlaser handling and electronic addressing and the optics of the microscope. Details of electronics and optics given here will be used in the larger arrays which should be available soon. After a description of the central Microlaser Microscope project, we touch briefly on the other projects of the Center, which have been outstandingly fruitful this year. Publications are necessarily concerned with the smaller projects, since the Microlaser Microscope is in its early stages.

  7. Tomographic findings of lobar consolidation in primary pulmonary tuberculosis

    International Nuclear Information System (INIS)

    Pereira, Bruno Alberto Falcao; Macedo, Solange Goncalves David de; Penna, Claudia Renata Rezende

    2009-01-01

    Objective: To describe tomographic findings of lobar consolidation as early manifestation of primary pulmonary tuberculosis. Materials and methods: The present study was developed at Hospital Municipal Jesus, Rio de Janeiro, RJ, Brazil, in the period between 2002 and 2006, retrospectively evaluating tomographic findings in four children aged from 3 to 14 months with lobar consolidation as an early manifestation of primary pulmonary tuberculosis. Results: The most frequently found radiological pattern was lobar consolidation with calcifications, cavitation and intermingle necrotic areas, associated with bulging fissure. Signs of bronchogenic dissemination and lymph node enlargement were observed in all of the four children. Consolidation with a pseudotumor aspect and masslike effect was observed in one case. Conclusion: The cases included in the present study have demonstrated that primary pulmonary tuberculosis manifested as lobar consolidation presents typical tomographic images such as cavitation, hypodense areas and calcifications intermingled with consolidation. The association with lymph node enlargement with central necrosis and signs of bronchogenic dissemination reinforce the diagnosis of tuberculosis. (author)

  8. Trailing edge noise estimation by tomographic Particle Image Velocimetry

    Science.gov (United States)

    Pröbsting, Stefan; Tuinstra, Marthijn; Scarano, Fulvio

    2015-06-01

    The feasibility of estimating broadband trailing edge noise with high-speed tomographic Particle Image Velocimetry (PIV) measurements is studied. A thin plate terminating in a sharp trailing edge provides a generic test case for turbulent boundary layer trailing edge interaction noise. Far-field noise is linked to the wavenumber-frequency spectrum of the surface pressure fluctuations in proximity of the trailing edge through diffraction theory. High-speed tomographic PIV measurements return volumetric and time-resolved information about all velocity components for the resolved spatio-temporal scales and can therefore provide the required statistical quantities. For the turbulent boundary layer interacting with the trailing edge, these statistics include the auto-spectral density, spanwise correlation length, and convection velocity of the unsteady surface pressure, which are thus estimated. Acoustic phased array measurements in an anechoic environment provide a reference for comparison. Over the resolved frequency band, PIV based noise estimation results compare favorably with the reference measurements. Especially at lower frequencies, where existing, empirical models for the unsteady surface pressure spectrum are not accurate, tomographic PIV can offer an alternative approach to complex and intrusive model instrumentation for assessing the relevant statistical quantities.

  9. Three dimensional reconstruction of tomographic images of the retina

    International Nuclear Information System (INIS)

    Glittenberg, C.; Zeiler, F.; Falkner, C.; Binder, S.; Povazay, B.; Hermann, B.; Drexler, W.

    2007-01-01

    The development of a new display system for the three-dimensional visualization of tomographic images in ophthalmology. Specifically, a system that can use stacks of B-mode scans from an ultrahigh resolution optical tomography examination to vividly display retinal specimens as three-dimensional objects. Several subroutines were programmed in the rendering and raytracing program Cinema 4D XL 9.102 Studio Bundle (Maxon Computer Inc., Friedrichsburg, Germany), which could process stacks of tomographic scans into three-dimensional objects. Ultrahigh resolution optical coherence tomography examinations were performed on patients with various retinal pathologies and post processed with the subroutines that had been designed. All ultrahigh resolution optical coherence tomographies were performed with a titanium: sapphire based ultra broad bandwidth (160 nm) femtosecond laser system (INTEGRAL, Femtolasers Productions GmbH. Vienna Austria) with an axial resolution of 3 μm. A new three dimensional display system for tomographic images in ophthalmology was developed, which allows a highly vivid display of physiological and pathological structures of the retina. The system also distinguishes itself through its high interactivity and adaptability. This new display system allows the visualization of physiological and pathological structures of the retina in a new way, which will give us new insight into their morphology and development. (author) [de

  10. A tomograph VMEbus parallel processing data acquisition system

    International Nuclear Information System (INIS)

    Atkins, M.S.; Wilkinson, N.A.; Rogers, J.G.

    1988-11-01

    This paper describes a VME based data acquisition system suitable for the development of Positron Volume Imaging tomographs which use 3-D data for improved image resolution over slice-oriented tomographs. The data acquisition must be flexible enough to accommodate several 3-D reconstruction algorithms; hence, a software-based system is most suitable. Furthermore, because of the increased dimensions and resolution of volume imaging tomographs, the raw data event rate is greater than that of slice-oriented machines. These dual requirements are met by our data acquisition systems. Flexibility is achieved through an array of processors connected over a VMEbus, operating asynchronously and in parallel. High raw data throughput is achieved using a dedicated high speed data transfer device available for the VMEbus. The device can attain a raw data rate of 2.5 million coincidence events per second for raw events per second for raw events which are 64 bits wide. Real-time data acquisition and pre-processing requirements can be met by about forty 20 MHz Motorola 68020/68881 processors

  11. Tomographic Particle Image Velocimetry Using Colored Shadow Imaging

    KAUST Repository

    Alarfaj, Meshal K.

    2016-02-01

    Tomographic Particle Image Velocimetry Using Colored Shadow Imaging by Meshal K Alarfaj, Master of Science King Abdullah University of Science & Technology, 2015 Tomographic Particle image velocimetry (PIV) is a recent PIV method capable of reconstructing the full 3D velocity field of complex flows, within a 3-D volume. For nearly the last decade, it has become the most powerful tool for study of turbulent velocity fields and promises great advancements in the study of fluid mechanics. Among the early published studies, a good number of researches have suggested enhancements and optimizations of different aspects of this technique to improve the effectiveness. One major aspect, which is the core of the present work, is related to reducing the cost of the Tomographic PIV setup. In this thesis, we attempt to reduce this cost by using an experimental setup exploiting 4 commercial digital still cameras in combination with low-cost Light emitting diodes (LEDs). We use two different colors to distinguish the two light pulses. By using colored shadows with red and green LEDs, we can identify the particle locations within the measurement volume, at the two different times, thereby allowing calculation of the velocities. The present work tests this technique on the flows patterns of a jet ejected from a tube in a water tank. Results from the images processing are presented and challenges discussed.

  12. A suggested theory of the conventional tomographic imaging process

    International Nuclear Information System (INIS)

    Moore, C.J.; Moores, B.M.

    1981-01-01

    An attempt is made to re-examine the well established theoretical basis of conventional tomography in the light of more detailed techniques being applied elsewhere in image analysis. Transfer function theory has been used to quantify the amount of edge detail reproduced by this process and the information in a tomogram is investigated in terms of edge detail associated with well resolved (unblurred) detail and also that associated with unresolved detail. Because resolved and unresolved detail is associated with particular anatomical layers within the tomographed object, the theory has been used to define a cut plane thickness. A variety of different tube movements have been considered and calculated values of cut plane thickness are compared with those predicted by a simple geometric model. Besides the blurring associated with the tube movement the effect of X-ray focal spot, film-screen combination and also visual response of the observer have been included and their importance in the definition of cut plane thickness highlighted. One advantage of this approach appears to be the facility to quantify the performance of different tomographic tube movements and highlight the role of tomographic detail reproduced from body sections well removed from the cut plane. (author)

  13. On thermodynamic and microscopic reversibility

    International Nuclear Information System (INIS)

    Crooks, Gavin E

    2011-01-01

    The word 'reversible' has two (apparently) distinct applications in statistical thermodynamics. A thermodynamically reversible process indicates an experimental protocol for which the entropy change is zero, whereas the principle of microscopic reversibility asserts that the probability of any trajectory of a system through phase space equals that of the time reversed trajectory. However, these two terms are actually synonymous: a thermodynamically reversible process is microscopically reversible, and vice versa

  14. Video-rate processing in tomographic phase microscopy of biological cells using CUDA.

    Science.gov (United States)

    Dardikman, Gili; Habaza, Mor; Waller, Laura; Shaked, Natan T

    2016-05-30

    We suggest a new implementation for rapid reconstruction of three-dimensional (3-D) refractive index (RI) maps of biological cells acquired by tomographic phase microscopy (TPM). The TPM computational reconstruction process is extremely time consuming, making the analysis of large data sets unreasonably slow and the real-time 3-D visualization of the results impossible. Our implementation uses new phase extraction, phase unwrapping and Fourier slice algorithms, suitable for efficient CPU or GPU implementations. The experimental setup includes an external off-axis interferometric module connected to an inverted microscope illuminated coherently. We used single cell rotation by micro-manipulation to obtain interferometric projections from 73 viewing angles over a 180° angular range. Our parallel algorithms were implemented using Nvidia's CUDA C platform, running on Nvidia's Tesla K20c GPU. This implementation yields, for the first time to our knowledge, a 3-D reconstruction rate higher than video rate of 25 frames per second for 256 × 256-pixel interferograms with 73 different projection angles (64 × 64 × 64 output). This allows us to calculate additional cellular parameters, while still processing faster than video rate. This technique is expected to find uses for real-time 3-D cell visualization and processing, while yielding fast feedback for medical diagnosis and cell sorting.

  15. Industrial dynamic tomographic reconstruction; Reconstrucao tomografica dinamica industrial

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Eric Ferreira de

    2016-07-01

    The state of the art methods applied to industrial processes is currently based on the principles of classical tomographic reconstructions developed for tomographic patterns of static distributions, or is limited to cases of low variability of the density distribution function of the tomographed object. Noise and motion artifacts are the main problems caused by a mismatch in the data from views acquired in different instants. All of these add to the known fact that using a limited amount of data can result in the presence of noise, artifacts and some inconsistencies with the distribution under study. One of the objectives of the present work is to discuss the difficulties that arise from implementing reconstruction algorithms in dynamic tomography that were originally developed for static distributions. Another objective is to propose solutions that aim at reducing a temporal type of information loss caused by employing regular acquisition systems to dynamic processes. With respect to dynamic image reconstruction it was conducted a comparison between different static reconstruction methods, like MART and FBP, when used for dynamic scenarios. This comparison was based on a MCNPx simulation as well as an analytical setup of an aluminum cylinder that moves along the section of a riser during the process of acquisition, and also based on cross section images from CFD techniques. As for the adaptation of current tomographic acquisition systems for dynamic processes, this work established a sequence of tomographic views in a just-in-time fashion for visualization purposes, a form of visually disposing density information as soon as it becomes amenable to image reconstruction. A third contribution was to take advantage of the triple color channel necessary to display colored images in most displays, so that, by appropriately scaling the acquired values of each view in the linear system of the reconstruction, it was possible to imprint a temporal trace into the regularly

  16. Scanning Miniature Microscopes without Lenses

    Science.gov (United States)

    Wang, Yu

    2009-01-01

    The figure schematically depicts some alternative designs of proposed compact, lightweight optoelectronic microscopes that would contain no lenses and would generate magnified video images of specimens. Microscopes of this type were described previously in Miniature Microscope Without Lenses (NPO - 20218), NASA Tech Briefs, Vol. 22, No. 8 (August 1998), page 43 and Reflective Variants of Miniature Microscope Without Lenses (NPO 20610), NASA Tech Briefs, Vol. 26, No. 9 (September 1999), page 6a. To recapitulate: In the design and construction of a microscope of this type, the focusing optics of a conventional microscope are replaced by a combination of a microchannel filter and a charge-coupled-device (CCD) image detector. Elimination of focusing optics reduces the size and weight of the instrument and eliminates the need for the time-consuming focusing operation. The microscopes described in the cited prior articles contained two-dimensional CCDs registered with two-dimensional arrays of microchannels and, as such, were designed to produce full two-dimensional images, without need for scanning. The microscopes of the present proposal would contain one-dimensional (line image) CCDs registered with linear arrays of microchannels. In the operation of such a microscope, one would scan a specimen along a line perpendicular to the array axis (in other words, one would scan in pushbroom fashion). One could then synthesize a full two-dimensional image of the specimen from the line-image data acquired at one-pixel increments of position along the scan. In one of the proposed microscopes, a beam of unpolarized light for illuminating the specimen would enter from the side. This light would be reflected down onto the specimen by a nonpolarizing beam splitter attached to the microchannels at their lower ends. A portion of the light incident on the specimen would be reflected upward, through the beam splitter and along the microchannels, to form an image on the CCD. If the

  17. The UF series of tomographic computational phantoms of pediatric patients

    International Nuclear Information System (INIS)

    Lee, Choonik; Williams, Jonathan L.; Lee, Choonsik; Bolch, Wesley E.

    2005-01-01

    Two classes of anthropomorphic computational phantoms exist for use in Monte Carlo radiation transport simulations: tomographic voxel phantoms based upon three-dimensional (3D) medical images, and stylized mathematical phantoms based upon 3D surface equations for internal organ definition. Tomographic phantoms have shown distinct advantages over the stylized phantoms regarding their similarity to real human anatomy. However, while a number of adult tomographic phantoms have been developed since the early 1990s, very few pediatric tomographic phantoms are presently available to support dosimetry in pediatric diagnostic and therapy examinations. As part of a larger effort to construct a series of tomographic phantoms of pediatric patients, five phantoms of different ages (9-month male, 4-year female, 8-year female, 11-year male, and 14-year male) have been constructed from computed tomography (CT) image data of live patients using an IDL-based image segmentation tool. Lungs, bones, and adipose tissue were automatically segmented through use of window leveling of the original CT numbers. Additional organs were segmented either semiautomatically or manually with the aid of both anatomical knowledge and available image-processing techniques. Layers of skin were created by adding voxels along the exterior contour of the bodies. The phantoms were created from fused images taken from head and chest-abdomen-pelvis CT exams of the same individuals (9-month and 4-year phantoms) or of two different individuals of the same sex and similar age (8-year, 11-year, and 14-year phantoms). For each model, the resolution and slice positions of the image sets were adjusted based upon their anatomical coverage and then fused to a single head-torso image set. The resolutions of the phantoms for the 9-month, 4-year, 8-year, 11-year, and 14-year are 0.43x0.43x3.0 mm, 0.45x0.45x5.0 mm, 0.58x0.58x6.0 mm, 0.47x0.47x6.00 mm, and 0.625x0.625x6.0 mm, respectively. While organ masses can be

  18. The accuracy of computed tomographic angiography for mapping the perforators of the DIEA: a cadaveric study.

    Science.gov (United States)

    Rozen, Warren M; Ashton, Mark W; Stella, Damien L; Phillips, Timothy J; Taylor, G Ian

    2008-08-01

    The deep inferior epigastric artery (DIEA) perforator flap is increasingly used for breast reconstruction, with preoperative imaging sought as a means of improving operative outcome. Computed tomographic angiography has been recently described as the preferred imaging modality; however, formal evaluation of computed tomographic angiography has not been described. A cadaveric study was undertaken to evaluate the accuracy of computed tomographic angiography for perforator mapping. Ten cadaveric hemiabdominal walls from five fresh cadavers underwent contrast injection of each DIEA and subsequent computed tomographic scanning, with each DIEA and all perforating branches documented. Dissection was then performed, with the recording of the course of the DIEA and the course of all perforators in each specimen. The concordance of computed tomographic angiography with dissection findings was evaluated. Cadaveric computed tomographic angiography identified 154 perforators in 10 hemiabdominal walls. Computed tomographic angiography was highly accurate, with eight false-positives and six false-negatives on cadaveric computed tomographic angiography, establishing an overall sensitivity of 96 percent and a positive predictive value of 95 percent for mapping perforators. For perforators greater than 1 mm in diameter, the sensitivity was 100 percent and the positive predictive value was 100 percent. Computed tomographic angiography is a highly accurate tool for identifying the perforators of the DIEA before DIEA perforator flaps for breast reconstruction. Preoperative identification of these vessels can aid planning for the preferred hemiabdomen for dissection, and may save operative time, angst, and potentially complications.

  19. Axiomatic electrodynamics and microscopic mechanics

    International Nuclear Information System (INIS)

    Yussouff, M.

    1981-04-01

    A new approach to theoretical physics, along with the basic formulation of a new MICROSCOPIC MECHANICS for the motion of small charged particles is described in this set of lecture notes. Starting with the classical (Newtonian) mechanics and classical fields, the important but well known properties of Classical Electromagnetic field are discussed up to section 4. The next nection describes the usual radiation damping theory and its difficulties. It is argued that the usual treatment of radiation damping is not valid for small space and time intervals and the true description of motion requires a new type of mechanics - the MICROSCOPIC MECHANICS: Section 6 and 7 are devoted to showing that not only the new microscopic mechanics goes over to Newtonian mechanics in the proper limit, but also it is closely connected with Quantum Mechanics. All the known results of the Schroedinger theory can be reproduced by microscopic mechanics which also gives a clear physical picture. It removes Einstein's famous objections against Quantum Theory and provides a clear distinction between classical and Quantum behavior. Seven Axioms (three on Classical Mechanics, two for Maxwell's theory, one for Relativity and a new Axiom on Radiation damping) are shown to combine Classical Mechanics, Maxwellian Electrodynamics, Relativity and Schroedinger's Quantum Theory within a single theoretical framework under Microscopic Mechanics which awaits further development at the present time. (orig.)

  20. Microscope and method of use

    Science.gov (United States)

    Bongianni, Wayne L.

    1984-01-01

    A method and apparatus for electronically focusing and electronically scanning microscopic specimens are given. In the invention, visual images of even moving, living, opaque specimens can be acoustically obtained and viewed with virtually no time needed for processing (i.e., real time processing is used). And planar samples are not required. The specimens (if planar) need not be moved during scanning, although it will be desirable and possible to move or rotate nonplanar specimens (e.g., laser fusion targets) against the lens of the apparatus. No coupling fluid is needed, so specimens need not be wetted. A phase acoustic microscope is also made from the basic microscope components together with electronic mixers.

  1. Atomic force microscope featuring an integrated optical microscope

    NARCIS (Netherlands)

    Putman, C.A.J.; Putman, Constant A.J.; de Grooth, B.G.; van Hulst, N.F.; Greve, Jan

    1992-01-01

    The atomic force microscope (AFM) is used to image the surface of both conductors and nonconductors. Biological specimens constitute a large group of nonconductors. A disadvantage of most AFM's is the fact that relatively large areas of the sample surface have to be scanned to pinpoint a biological

  2. Infrared up-conversion microscope

    DEFF Research Database (Denmark)

    2014-01-01

    There is presented an up-conversion infrared microscope (110) arranged for imaging an associated object (130), wherein the up-conversion infrared microscope (110) comprises a non-linear crystal (120) arranged for up-conversion of infrared electromagnetic radiation, and wherein an objective optical...... component (100) has an entrance pupil with a first diameter D1, and an optical component system which is arranged for forming an external image (136) of the back-focal plane (132) of the objective optical component (100), which has a diameter (given by the diameter of a circle enclosing all optical paths...

  3. Dense velocity reconstruction from tomographic PTV with material derivatives

    Science.gov (United States)

    Schneiders, Jan F. G.; Scarano, Fulvio

    2016-09-01

    A method is proposed to reconstruct the instantaneous velocity field from time-resolved volumetric particle tracking velocimetry (PTV, e.g., 3D-PTV, tomographic PTV and Shake-the-Box), employing both the instantaneous velocity and the velocity material derivative of the sparse tracer particles. The constraint to the measured temporal derivative of the PTV particle tracks improves the consistency of the reconstructed velocity field. The method is christened as pouring time into space, as it leverages temporal information to increase the spatial resolution of volumetric PTV measurements. This approach becomes relevant in cases where the spatial resolution is limited by the seeding concentration. The method solves an optimization problem to find the vorticity and velocity fields that minimize a cost function, which includes next to instantaneous velocity, also the velocity material derivative. The velocity and its material derivative are related through the vorticity transport equation, and the cost function is minimized using the limited-memory Broyden-Fletcher-Goldfarb-Shanno (L-BFGS) algorithm. The procedure is assessed numerically with a simulated PTV experiment in a turbulent boundary layer from a direct numerical simulation (DNS). The experimental validation considers a tomographic particle image velocimetry (PIV) experiment in a similar turbulent boundary layer and the additional case of a jet flow. The proposed technique (`vortex-in-cell plus', VIC+) is compared to tomographic PIV analysis (3D iterative cross-correlation), PTV interpolation methods (linear and adaptive Gaussian windowing) and to vortex-in-cell (VIC) interpolation without the material derivative. A visible increase in resolved details in the turbulent structures is obtained with the VIC+ approach, both in numerical simulations and experiments. This results in a more accurate determination of the turbulent stresses distribution in turbulent boundary layer investigations. Data from a jet

  4. Imaging MOSS tomographic system for H-1NF

    International Nuclear Information System (INIS)

    Glass, F.; Howard, J.

    1999-01-01

    A tomographic diagnostic utilising the Modulated Optical Solid-State spectrometer (MOSS) is planned for the H-1NF stellarator at the ANU. It is designed to create two-dimensional temperature or velocity maps of a poloidal cross-section of the high temperature plasma of H-1NF. The introduction of the MOSS spectrometers has enabled the development of several diagnostics to be used on the H-1NF stellerator. The MOSS spectrometer allows calculations of the plasma temperature and bulk velocity based on a line-integrated measurement of light emitted from electronic transitions within the plasma. A tomographic system utilising a rotatable multi-view ring apparatus and spatial multiplexing through a MOSS spectrometer is currently being developed. The ring apparatus is placed inside the H-1NF vessel and encircles the plasma. Multiple line-of-sight views collect light through a poloidal cross-section of the plasma and the emitted light is coupled into large core optical fibres. The transmitted light, via the optical fibre bundle, is then imaged through a large aperture MOSS spectrometer and onto another optical fibre array. Each fibre is then fed into a photomultiplier tube for signal detection. Characterisation of the properties of the lithium niobate (LiNbO 3 ) crystal used for modulation in the MOSS spectrometer is being undertaken to account for ray divergence in the imaging system. Tomographic techniques enable the construction of a temperature or velocity map of the poloidal cross-section. Rotating the ring apparatus to a new viewing position for the next pulse of plasma should allow an accurate picture to be built up based on the reproducibility of the plasma pulses. It is expected that initial testing of the system will begin in May when H-1NF begins operations at 0.5 Telsa field strength

  5. Development of the Shimadzu computed tomographic scanner SCT-200N

    International Nuclear Information System (INIS)

    Ishihara, Hiroshi; Yamaoka, Nobuyuki; Saito, Masahiro

    1982-01-01

    The Shimadzu Computed Tomographic Scanner SCT-200N has been developed as an ideal CT scanner for diagnosing the head and spine. Due to the large aperture, moderate scan time and the Zoom Scan Mode, any part of the body can be scanned. High quality image can be obtained by adopting the precisely stabilized X-ray unit and densely packed array of 64-detectors. As for its operation, capability of computed radiography (CR) prior to patient positioning and real time reconstruction ensure efficient patient through-put. Details of the SCT-200N are described in this paper. (author)

  6. Technical innovation: Multidimensional computerized software enabled subtraction computed tomographic angiography.

    Science.gov (United States)

    Bhatia, Mona; Rosset, Antoine; Platon, Alexandra; Didier, Dominique; Becker, Christoph D; Poletti, Pierre-Alexandre

    2010-01-01

    Computed tomographic angiography (CTA) is a frequent noninvasive alternative to digital subtraction angiography. We previously reported the development of a new subtraction software to overcome limitations of adjacent bone and calcification in CT angiographic subtraction. Our aim was to further develop and improve this fast and automated computerized software, universally available for free use and compatible with most CT scanners, thus enabling better delineation of vascular structures, artifact reduction, and shorter reading times with potential clinical benefits. This computer-based free software will be available as an open source in the next release of OsiriX at the Web site http://www.osirix-viewer.com.

  7. Pressure spectra from single-snapshot tomographic PIV

    Science.gov (United States)

    Schneiders, Jan F. G.; Avallone, Francesco; Pröbsting, Stefan; Ragni, Daniele; Scarano, Fulvio

    2018-03-01

    The power spectral density and coherence of temporal pressure fluctuations are obtained from low-repetition-rate tomographic PIV measurements. This is achieved by extension of recent single-snapshot pressure evaluation techniques based upon the Taylor's hypothesis (TH) of frozen turbulence and vortex-in-cell (VIC) simulation. Finite time marching of the measured instantaneous velocity fields is performed using TH and VIC. Pressure is calculated from the resulting velocity time series. Because of the theoretical limitations, the finite time marching can be performed until the measured flow structures are convected out of the measurement volume. This provides a lower limit of resolvable frequency range. An upper limit is given by the spatial resolution of the measurements. Finite time-marching approaches are applied to low-repetition-rate tomographic PIV data of the flow past a straight trailing edge at 10 m/s. Reference results of the power spectral density and coherence are obtained from surface pressure transducers. In addition, the results are compared to state-of-the-art experimental data obtained from time-resolved tomographic PIV performed at 10 kHz. The time-resolved approach suffers from low spatial resolution and limited maximum acquisition frequency because of hardware limitations. Additionally, these approaches strongly depend upon the time kernel length chosen for pressure evaluation. On the other hand, the finite time-marching approaches make use of low-repetition-rate tomographic PIV measurements that offer higher spatial resolution. Consequently, increased accuracy of the power spectral density and coherence of pressure fluctuations are obtained in the high-frequency range, in comparison to the time-resolved measurements. The approaches based on TH and VIC are found to perform similarly in the high-frequency range. At lower frequencies, TH is found to underestimate coherence and intensity of the pressure fluctuations in comparison to time-resolved PIV

  8. Gas microstrip detectors for X-ray tomographic flow imaging

    CERN Document Server

    Key, M J; Luggar, R D; Kundu, A

    2003-01-01

    A investigation into the suitability of gas microstrip detector technology for a high-speed industrial X-ray tomography system is reported. X-ray energies in the region 20-30 keV are well suited to the application, which involves imaging two-dimensional slices through gas/liquid multiphase pipeline flows for quantitative component fraction measurement. Stable operation over a period representing several hundred individual tomographic scans at gas gains of 500 is demonstrated using a Penning gas mixture of krypton/propylene.

  9. Towards a tomographic reconstruction of neutron depolarization data

    International Nuclear Information System (INIS)

    Schulz, Michael; Neubauer, Andreas; Muehlbauer, Martin; Schillinger, Burkhard; Pfleiderer, Christian; Boeni, Peter; Masalovich, Sergey; Calzada, Elbio

    2010-01-01

    In this paper we show a first approach to the three dimensional reconstruction of spatially resolved neutron depolarization data. We will show measurements with a position sensitive CCD detector on a longitudinal polarization analysis setup using 3 He polarizers and analyzers installed at the radiography beamline ANTARES at FRM II, Munich. A tomographic reconstruction of data acquired with an inhomogeneous Pd 1-x Ni x sample shows that this method is a powerful tool to identify regions of different magnetic properties inside the sample.

  10. Towards a tomographic reconstruction of neutron depolarization data

    Energy Technology Data Exchange (ETDEWEB)

    Schulz, Michael; Neubauer, Andreas; Muehlbauer, Martin; Schillinger, Burkhard; Pfleiderer, Christian; Boeni, Peter [Technische Universitaet Muenchen, Physik Department, E21, James Franck Str, 85748 Garching (Germany); Masalovich, Sergey; Calzada, Elbio, E-mail: michael.schulz@frm2.tum.d [Technische Universitaet Muenchen, Forschungsneutronenquelle Heinz Maier Leibnitz (FRM II), Lichtenbergstr. 1, 85748 Garching (Germany)

    2010-02-01

    In this paper we show a first approach to the three dimensional reconstruction of spatially resolved neutron depolarization data. We will show measurements with a position sensitive CCD detector on a longitudinal polarization analysis setup using {sup 3}He polarizers and analyzers installed at the radiography beamline ANTARES at FRM II, Munich. A tomographic reconstruction of data acquired with an inhomogeneous Pd{sub 1-x}Ni{sub x} sample shows that this method is a powerful tool to identify regions of different magnetic properties inside the sample.

  11. Non tumoral intracranial expansive processes: clinical tomographic correlation

    International Nuclear Information System (INIS)

    Campos, P.; Herrera, G.; Valneica, F.

    1991-01-01

    Presentation of clinical-tomographic correlation in 111 cases of non tumoral intracranial expansive processes seen between 1984-1988 in the Hospital Cayetano Heredia (Lima, Peru). Emphasis is given fundamentally to: the importance of establishing the organicity of partial and late epilepsy; the high incidence rate of inflammatory infectious processes with CNS compromise in under developing countries; the necessity of making public the importance of two parasitic diseases in the differential diagnosis of non tumoral intracranial expansive processes: free living amebiasis, and toxoplasmosis (especially in association with AIDS). (author)

  12. Air-Coupled Ultrasonic Tomographic Imaging for Solids

    Science.gov (United States)

    Hall, K. S.; Popovics, J. S.

    2009-03-01

    Ultrasonic tomography is a powerful tool for identifying defects within an object or structure. Ultrasonic tomography is limited by time consuming transducer coupling. Air-coupled UPV may eliminate this problem and allow for more rapid data collection. This research aims to integrate recent developments in air-coupled ultrasonic measurements with the current tomography technology to image inclusions within solids. Air-coupled ultrasonic signals are collected though large PVC samples. Volumetric and planar inclusions within the samples are identified in the constructed velocity tomographs.

  13. Direct computation of harmonic moments for tomographic reconstruction

    International Nuclear Information System (INIS)

    Nara, Takaaki; Ito, Nobutaka; Takamatsu, Tomonori; Sakurai, Tetsuya

    2007-01-01

    A novel algorithm to compute harmonic moments of a density function from its projections is presented for tomographic reconstruction. For projection p(r, θ), we define harmonic moments of projection by ∫ π 0 ∫ ∞ -∞ p(r,θ)(re iθ ) n drd θ and show that it coincides with the harmonic moments of the density function except a constant. Furthermore, we show that the harmonic moment of projection of order n can be exactly computed by using n+ 1 projection directions, which leads to an efficient algorithm to reconstruct the vertices of a polygon from projections.

  14. Computed tomographic myelography (CTM) in atlanto-axial rheumatoid arthritis

    International Nuclear Information System (INIS)

    Laasonen, E.M.; Servo, A.; Kankaanpaeae, U.; Paukku, P.; Sandelin, J.; Slaetis, P.

    1985-01-01

    Thirty-two patients with severe cervical rheumatoid arthritis were investigated preoperatively with cervical myelography (CeM) and computed tomographic myelography (CTM). The severity of their clinical symptoms correlated excellently with a combination of the deformation of the spinal cord at the atlanto-axial level, the lateral dislocation of the cord at the same level, and the deformation of the cord at some lower cervical level. Obstructing softtissue excrescences seemed to have little value. No correlation was found in this study between the deformation of the cord and the main findings of the plain films: the atlanto-axial subluxation (AAS), the vertical subluxation (VS), or their combination. (orig.)

  15. A PC-controlled microwave tomographic scanner for breast imaging

    Science.gov (United States)

    Padhi, Shantanu; Howard, John; Fhager, A.; Bengtsson, Sebastian

    2011-01-01

    This article presents the design and development of a personal computer based controller for a microwave tomographic system for breast cancer detection. The system uses motorized, dual-polarized antennas and a custom-made GUI interface to control stepper motors, a wideband vector network analyzer (VNA) and to coordinate data acquisition and archival in a local MDSPlus database. Both copolar and cross-polar scattered field components can be measured directly. Experimental results are presented to validate the various functionalities of the scanner.

  16. Research on improving performance to metallographic microscopes

    Directory of Open Access Journals (Sweden)

    Teodor Socaciu

    2011-12-01

    Full Text Available Precision optical components from an old optical microscope can be improved and emphasized with a dedicated digital microscope camera. This is an affordable way to obtain a high performance metallographic or biological microscope, with minimum of spending. This paper study those ways and adapts a camera to existing microscopes for researchers use, Optimizing visualization by projecting the image and improving the microscope use by different options of capture and image processing.

  17. Curriculum Guidelines for Microscopic Anatomy.

    Science.gov (United States)

    Journal of Dental Education, 1993

    1993-01-01

    The American Association of Dental Schools' guidelines for curricula in microscopic anatomy offer an overview of the histology curriculum, note primary educational goals, outline specific content for general and oral histology, suggest prerequisites, and make recommendations for sequencing. Appropriate faculty and facilities are also suggested.…

  18. Microscopic cross sections: An utopia?

    Energy Technology Data Exchange (ETDEWEB)

    Hilaire, S. [CEA Bruyeres-le-Chatel, DIF 91 (France); Koning, A.J. [Nuclear Research and Consultancy Group, PO Box 25, 1755 ZG Petten (Netherlands); Goriely, S. [Institut d' Astronomie et d' Astrophysique, Universite Libre de Bruxelles, Campus de la Plaine, CP 226, 1050 Brussels (Belgium)

    2010-07-01

    The increasing need for cross sections far from the valley of stability poses a challenge for nuclear reaction models. So far, predictions of cross sections have relied on more or less phenomenological approaches, depending on parameters adjusted to available experimental data or deduced from systematical relations. While such predictions are expected to be reliable for nuclei not too far from the experimentally known regions, it is clearly preferable to use more fundamental approaches, based on sound physical bases, when dealing with very exotic nuclei. Thanks to the high computer power available today, all major ingredients required to model a nuclear reaction can now be (and have been) microscopically (or semi-microscopically) determined starting from the information provided by a nucleon-nucleon effective interaction. We have implemented all these microscopic ingredients in the TALYS nuclear reaction code, and we are now almost able to perform fully microscopic cross section calculations. The quality of these ingredients and the impact of using them instead of the usually adopted phenomenological parameters will be discussed. (authors)

  19. Microscopic cross sections: An utopia?

    International Nuclear Information System (INIS)

    Hilaire, S.; Koning, A.J.; Goriely, S.

    2010-01-01

    The increasing need for cross sections far from the valley of stability poses a challenge for nuclear reaction models. So far, predictions of cross sections have relied on more or less phenomenological approaches, depending on parameters adjusted to available experimental data or deduced from systematical relations.While such predictions are expected to be reliable for nuclei not too far from the experimentally known regions, it is clearly preferable to use more fundamental approaches, based on sound physical bases, when dealing with very exotic nuclei. Thanks to the high computer power available today, all major ingredients required to model a nuclear reaction can now be (and have been) microscopically (or semi-microscopically) determined starting from the information provided by a nucleon-nucleon effective interaction. We have implemented all these microscopic ingredients in the TALYS nuclear reaction code, and we are now almost able to perform fully microscopic cross section calculations. The quality of these ingredients and the impact of using them instead of the usually adopted phenomenological parameters will be discussed. (authors)

  20. Microscope sterility during spine surgery.

    Science.gov (United States)

    Bible, Jesse E; O'Neill, Kevin R; Crosby, Colin G; Schoenecker, Jonathan G; McGirt, Matthew J; Devin, Clinton J

    2012-04-01

    Prospective study. Assess the contamination rates of sterile microscope drapes after spine surgery. The use of the operating microscope has become more prevalent in certain spine procedures, providing superior magnification, visualization, and illumination of the operative field. However, it may represent an additional source of bacterial contamination and increase the risk of developing a postoperative infection. This study included 25 surgical spine cases performed by a single spine surgeon that required the use of the operative microscope. Sterile culture swabs were used to obtain samples from 7 defined locations on the microscope drape after its use during the operation. The undraped technician's console was sampled in each case as a positive control, and an additional 25 microscope drapes were swabbed immediately after they were applied to the microscope to obtain negative controls. Swab samples were assessed for bacterial growth on 5% sheep blood Columbia agar plates using a semiquantitative technique. No growth was observed on any of the 25 negative control drapes. In contrast, 100% of preoperative and 96% of postoperative positive controls demonstrated obvious contamination. In the postoperative group, all 7 sites of evaluation were found to be contaminated with rates of 12% to 44%. Four of the 7 evaluated locations were found to have significant contamination rates compared with negative controls, including the shafts of the optic eyepieces on the main surgeon side (24%, P = 0.022), "forehead" portion on both the main surgeon (24%, P = 0.022) and assistant sides (28%, P = 0.010), and "overhead" portion of the drape (44%, P = 0.0002). Bacterial contamination of the operative microscope was found to be significant after spine surgery. Contamination was more common around the optic eyepieces, likely due to inadvertent touching of unsterile portions. Similarly, all regions above the eyepieces also have a propensity for contamination because of unknown contact

  1. Large-scale volumetric pressure from tomographic PTV with HFSB tracers

    NARCIS (Netherlands)

    Schneiders, J.F.G.; Caridi, Giuseppe Carlo Alp; Sciacchitano, A.; Scarano, F.

    2016-01-01

    The instantaneous volumetric pressure in the near-wake of a truncated cylinder is measured by use of tomographic particle tracking velocimetry (PTV) using helium-filled soap bubbles (HFSB) as tracers. The measurement volume is several orders of magnitude larger than that reported in tomographic

  2. Resolving vorticity and dissipation in a turbulent boundary layer by tomographic PTV and VIC+

    NARCIS (Netherlands)

    Schneiders, J.F.G.; Scarano, F.; Elsinga, G.E.

    2017-01-01

    The existing time-resolved tomographic particle image velocimetry (PIV) measurements by Jodai and Elsinga (J Fluid Mech 795:611–633; Jodai, Elsinga, J Fluid Mech 795:611–633, 2016) in a turbulent boundary layer (Reθ = 2038) are reprocessed using tomographic particle tracking

  3. Computed tomographic features of fibrous dysplasia of maxillofacial region.

    Science.gov (United States)

    Sontakke, Subodh Arun; Karjodkar, Freny R; Umarji, Hemant R

    2011-03-01

    This study was to find the computed tomographic features of fibrous dysplasia of the maxillofacial region. All eight cases included in the study reported either to Government Dental College and Hospital or Nair Hospital Dental College, Mumbai between 2003 and 2009. The patients were prescribed computed tomogram in addition to conventional radiographs of maxillofacial region which were studied for characteristic features of fibrous dysplasia. The diagnosis of fibrous dysplasia was confirmed by histopathological report. All cases showed the ill-defined margins of lesions except in the region where the lesions were extending to cortex of the involved bone. Internal structure of all cases showed ground glass appearance. Four cases of maxillary lesion showed the displacement of maxillary sinus maintaining the shape of maxillary sinus. Two cases showed complete obliteration of maxillary sinus. Displacement of inferior alveolar canal did not follow any typical pattern in any of the cases but was displaced in different directions. The craniofacial type of fibrous dysplasia is as common as fibrous dysplasia of jaw. The margins, extent, internal structure and effect on surrounding structure are well detected on computed tomographic images.

  4. Computed tomographic features of fibrous dysplasia of maxillofacial region

    International Nuclear Information System (INIS)

    Sontakke, Subodh Arun; Karjodka, Freny R; Umarji, Hemant R

    2011-01-01

    This study was to find the computed tomographic features of fibrous dysplasia of the maxillofacial region. All eight cases included in the study reported either to Government Dental College and Hospital or Nair Hospital Dental College, Mumbai between 2003 and 2009. The patients were prescribed computed tomogram in addition to conventional radiographs of maxillofacial region which were studied for characteristic features of fibrous dysplasia. The diagnosis of fibrous dysplasia was confirmed by histopathological report. All cases showed the ill-defined margins of lesions except in the region where the lesions were extending to cortex of the involved bone. Internal structure of all cases showed ground glass appearance. Four cases of maxillary lesion showed the displacement of maxillary sinus maintaining the shape of maxillary sinus. Two cases showed complete obliteration of maxillary sinus. Displacement of inferior alveolar canal did not follow any typical pattern in any of the cases but was displaced in different directions. The craniofacial type of fibrous dysplasia is as common as fibrous dysplasia of jaw. The margins, extent, internal structure and effect on surrounding structure are well detected on computed tomographic images.

  5. Computed tomographic features of fibrous dysplasia of maxillofacial region

    Energy Technology Data Exchange (ETDEWEB)

    Sontakke, Subodh Arun; Karjodka, Freny R [Nair Hospital Dental College, Mumba (India); Umarji, Hemant R [Government Dental College and Hospital, Mumbai (India)

    2011-03-15

    This study was to find the computed tomographic features of fibrous dysplasia of the maxillofacial region. All eight cases included in the study reported either to Government Dental College and Hospital or Nair Hospital Dental College, Mumbai between 2003 and 2009. The patients were prescribed computed tomogram in addition to conventional radiographs of maxillofacial region which were studied for characteristic features of fibrous dysplasia. The diagnosis of fibrous dysplasia was confirmed by histopathological report. All cases showed the ill-defined margins of lesions except in the region where the lesions were extending to cortex of the involved bone. Internal structure of all cases showed ground glass appearance. Four cases of maxillary lesion showed the displacement of maxillary sinus maintaining the shape of maxillary sinus. Two cases showed complete obliteration of maxillary sinus. Displacement of inferior alveolar canal did not follow any typical pattern in any of the cases but was displaced in different directions. The craniofacial type of fibrous dysplasia is as common as fibrous dysplasia of jaw. The margins, extent, internal structure and effect on surrounding structure are well detected on computed tomographic images.

  6. Initial results from the Donner 600 crystal positron tomograph

    International Nuclear Information System (INIS)

    Derenzo, S.E.; Huesman, R.H.; Cahoon, J.L.; Geyer, A.; Uber, D.; Vuletich, T.; Budinger, T.F.

    1986-10-01

    We describe a positron tomograph using a single ring of 600 close-packed 3 mm wide bismuth germanate (BGO) crystals coupled to 14 mm phototubes. The phototube preamplifier circuit derives a timing pulse from the first photoelectron, and sends it to address and coincidence circuits only if the integrated pulse height is within a pre-set window. The timing delays and pulse height windows for all 600 detectors and the coincidence timing windows are computer adjustable. An orbiting positron source is used for transmission measurements and a look-up table is used to reject scattered and random coincidences that do not pass through the source. Data can be acquired using a stationary mode for 1.57 mm lateral sampling or the two-position clam sampling mode for 0.79 mm lateral sampling. High maximum data rates are provided by 45 parallel coincidence circuits and 4 parallel histogram memory units. With two-position sampling and 1.57 mm bins, the reconstructed point spread function (PSF) of a 0.35 mm diam 22 Na wire source at the center of the tomograph is circular with 2.9 mm full-width at half-maximum (fwhm) and the PSF at a distance of 8 cm from the center is elliptical with a radial fwhm of 4.0 mm and tangential fwhm of 3.0 mm. 12 refs., 6 figs., 3 tabs

  7. Tomographic Constraints on High-Energy Neutrinos of Hadronuclear Origin.

    Science.gov (United States)

    Ando, Shin'ichiro; Tamborra, Irene; Zandanel, Fabio

    2015-11-27

    Mounting evidence suggests that the TeV-PeV neutrino flux detected by the IceCube telescope has mainly an extragalactic origin. If such neutrinos are primarily produced by a single class of astrophysical sources via hadronuclear (pp) interactions, a similar flux of gamma-ray photons is expected. For the first time, we employ tomographic constraints to pinpoint the origin of the IceCube neutrino events by analyzing recent measurements of the cross correlation between the distribution of GeV gamma rays, detected by the Fermi satellite, and several galaxy catalogs in different redshift ranges. We find that the corresponding bounds on the neutrino luminosity density are up to 1 order of magnitude tighter than those obtained by using only the spectrum of the gamma-ray background, especially for sources with mild redshift evolution. In particular, our method excludes any hadronuclear source with a spectrum softer than E^{-2.1} as a main component of the neutrino background, if its evolution is slower than (1+z)^{3}. Starburst galaxies, if able to accelerate and confine cosmic rays efficiently, satisfy both spectral and tomographic constraints.

  8. A fast multi-resolution approach to tomographic PIV

    Science.gov (United States)

    Discetti, Stefano; Astarita, Tommaso

    2012-03-01

    Tomographic particle image velocimetry (Tomo-PIV) is a recently developed three-component, three-dimensional anemometric non-intrusive measurement technique, based on an optical tomographic reconstruction applied to simultaneously recorded images of the distribution of light intensity scattered by seeding particles immersed into the flow. Nowadays, the reconstruction process is carried out mainly by iterative algebraic reconstruction techniques, well suited to handle the problem of limited number of views, but computationally intensive and memory demanding. The adoption of the multiplicative algebraic reconstruction technique (MART) has become more and more accepted. In the present work, a novel multi-resolution approach is proposed, relying on the adoption of a coarser grid in the first step of the reconstruction to obtain a fast estimation of a reliable and accurate first guess. A performance assessment, carried out on three-dimensional computer-generated distributions of particles, shows a substantial acceleration of the reconstruction process for all the tested seeding densities with respect to the standard method based on 5 MART iterations; a relevant reduction in the memory storage is also achieved. Furthermore, a slight accuracy improvement is noticed. A modified version, improved by a multiplicative line of sight estimation of the first guess on the compressed configuration, is also tested, exhibiting a further remarkable decrease in both memory storage and computational effort, mostly at the lowest tested seeding densities, while retaining the same performances in terms of accuracy.

  9. Clinical findings in 16 patients with tomographic diagnosis of schizencephaly

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Maria do Carmo de Souza [Universidade Federal do Espirito Santo, Vitoria, ES (Brazil). Hospital Universitario Cassiano Antonio Moraes]. E-mail: rodriguesmcs@yahoo.com.br; Monteiro, Alexandra Maria Vieira [Universidade do Estado do Rio de Janeiro, RJ (Brazil). Faculdade de Ciencias Medicas; Llerena Junior, Juan Clinton [Fundacao Oswaldo Cruz, Rio de Janeiro, RJ (Brazil). Instituto Fernandes Figueira. Centro de Genetica Medica; Fernandes, Alexandre Ribeiro [Universidade Gama Filho, Rio de Janeiro, RJ (Brazil). Dept. de Pediatria

    2006-09-15

    Objective: to establish a correlation between clinical features in a group of children with tomographic diagnosis of schizencephaly and clefts extent and localization. Materials and methods: retrospective study of dossiers from the archives of Neurology and Medical Genetics Services at Instituto Fernandes Figueira/FIOCRUZ and Hospital Municipal Jesus, Rio de Janeiro, RJ, Brazil, in the period between 2000 and 2003. The study included 16 patients, nine female and seven male, with tomographic diagnosis of schizencephaly investigated for clinical findings, psychomotor development, motor/cognitive deficits and epilepsy. Results: predominance of bilateral clefts in 10:16 patients, open-lip schizencephaly type in 23:27 patients, and small lips in 11:27 patients. As regards anomalies associated with schizencephaly, pellucid septum absence was the most frequent one (10:16 patients). As regards clinical findings, 15 patients presented with developmental delay and motor deficit, six patients with cognitive deficit and ten with epilepsy. In three patients, we observed discordant clinical findings and cleft sizes, although the clefts were small, the clinical features severity was high because of other cerebral anomalies. Conclusion: the clinical features of schizencephaly are related to the size of the clefts, regardless laterality, presenting higher severity when associated with other cerebral anomalies. (author)

  10. Spontaneous Intracerebral Hemorrhage: Computed Tomographic Characteristics and Outcome

    Directory of Open Access Journals (Sweden)

    Aimara de la Caridad Vergara Santos

    2015-12-01

    Full Text Available Background: strokes are the third leading cause of death among adults and 10-15 % of them are due to spontaneous intracerebral hemorrhage. Objective: to characterize spontaneous intracerebral hemorrhage through computed tomography scan and its outcome. Methods: a case series study was conducted comprising patients diagnosed with spontaneous intracerebral hemorrhage admitted to the Arnaldo Milián Castro Provincial University Hospital in Villa Clara from January 2009 to January 2010. Tomographic variables of interest were derived from evaluation of spontaneous intracerebral hematomas. Results: fifty-nine cases of spontaneous intracerebral hemorrhage were studied, 23 were located in lobar regions, 4 had severe midline shift, and 2 showed volume greater than 80 ml. Eight out of eleven with extension into the ventricular system had an unfavorable outcome. Among those with thalamic hemorrhage, patients with diameter larger than 4cm and extension into the ventricular system died. Patients with putaminal hemorrhage larger than 4 cm and posterior fossa hematoma with hydrocephalus had a poor outcome, as well as most individuals (55 with other mass effects. Most lobar hematomas (14 out of 23 had a satisfactory outcome, unlike cerebellar and brainstem hematomas. Conclusions: tomographic variables that had a negative impact on the outcome were: volume greater than 80 ml, severe midline shift, diameter larger than 4 cm, extension into the ventricular system, hydrocephalus, other signs of mass effect and brainstem location.

  11. A SPICE Blind Test to Benchmark Global Tomographic Methods

    Science.gov (United States)

    Qin, Y.; Capdeville, Y.; Maupin, V.; Montagner, J.

    2006-12-01

    The different existing global tomographic methods result in different models of the Earth. In order to test how current imaging techniques are limited by approximations in theory and the inadequacy of data quality and coverage, we are undertaking a blind test of global inversion algorithms using complete 3D synthetic seismograms within SPICE (Seismic wave Propagation and Imaging in Complex media: a European network). First, a complex global anisotropic anelastic model has been constructed by summing the 1D reference model, deterministic and random anomalies and anisotropic crystal. This model includes 3D heterogeneities in velocity, anisotropy and attenuation at different scales in the whole mantle, as well as topography and crustal structure. In addition, the rotation and ellipticity are also included. Synthetic seismograms were generated using the Coupling Spectral Element Method with a minimum period of 32s, for a realistic distribution of 29 events and 256 stations. The synthetic seismograms have been made available to the scientific community worldwide at the IPGP website http://www.ipgp.jussieu.fr/~qyl/. Any group willing to test his tomographic technique is encouraged to download the synthetic dataset.g

  12. Snowpack permittivity profile retrieval from tomographic SAR data

    Science.gov (United States)

    Rekioua, Badreddine; Davy, Matthieu; Ferro-Famil, Laurent; Tebaldini, Stefano

    2017-01-01

    This work deals with 3D structure characterization and permittivity profile retrieval of snowpacks by tomographic SAR data processing. The acquisition system is a very high resolution ground based SAR system, developed and operated by the SAPHIR team, of IETR, University of Rennes-1 (France). It consists mainly of a vector network analyser and a multi-static antenna system, moving along two orthogonal directions, so as to obtain a two-dimensional synthetic array. Data were acquired during the AlpSAR campaign carried by the European Space Agency and led by ENVEO. In this study, tomographic imaging is performed using Time Domain Back Projection and consists in coherently combining the different recorded backscatter contributions. The assumption of free-space propagation during the focusing process is discussed and illustrated by focusing experimental data. An iterative method for estimating true refractive indices of the snow layers is presented. The antenna pattern is also compensated for. The obtained tomograms after refractive index correction are compared to the stratigraphy of the observed snowpack.

  13. Tomographic Environmental Sections for Environmental Mitigation Devices in Historical Centers

    Directory of Open Access Journals (Sweden)

    Roberta Cocci Grifoni

    2017-03-01

    Full Text Available Urban heat waves and the overall growing trend in the annual global temperature underline the importance of urban/architectural resilience and the need to reduce energy consumption. By designing urban voids, it is possible to create thermodynamic buffers, i.e., bubbles of controlled atmosphere that act as mediators between the natural and built environments, between the human body and the surrounding air, between meteorology and physiology (meteorological architecture. Multiple small actions in the urban fabric’s open spaces, such as replacing dark pavements or inserting vegetation and green spaces, are intended to improve outdoor comfort conditions and therefore the resilience of the city itself. This not only benefits the place’s quality, which is intrinsic to the new project, but also the insulating capacity of buildings, which are relieved of an external heat load. The design emphasis therefore changes from solid structures to the climate and weather conditions, which are invisible but perceivable. To design and control these constructed atmopheres, tomographic sections processed with computational fluid dynamics software (tomographic environmental section, TENS becomes necessary. It allows the effects of an extreme event on an outdoor environment to be evaluated in order to establish the appropriate (adaptive climate mitigation devices, especially in historical centers where energy retrofits are often discouraged. By fixing boundary conditions after a local intervention, the virtual environment can be simulated and then "sliced" to analyze initial values and verify the design improvements.

  14. A 3-dimensional computed tomographic procedure for planning retrosigmoid craniotomy.

    Science.gov (United States)

    Hamasaki, Tadashi; Morioka, Motohiro; Nakamura, Hideo; Yano, Shigetoshi; Hirai, Toshinori; Kuratsu, Jun-ichi

    2009-05-01

    The planning of retrosigmoid craniotomies often relies on anatomic landmarks on the posterolateral surface of the cranium, such as the asterion. However, the location of the asterion is not fixed with respect to the underlying transverse-sigmoid sinus complex. We introduce a simple procedure that uses 3-dimensional (3D) computed tomographic imaging to project the transverse-sigmoid sinus complex onto the external surface of the cranium. We enrolled 8 patients scheduled for retrosigmoid craniotomy (Group 1) and 30 patients without posterior fossa lesions (Group 2). The procedure consists of 3 steps: 1) marking the sinus on the internal surface on 3D images of the cranium, 2) transferring the marks to the external surface on axial images, and 3) checking the transferred marks on the external surface of the cranium on 3D images. In Group 1, the craniotomies planned with the aid of our procedure coincided with findings made at surgery, indicating the accuracy of our procedure. When we applied it in morphometric studies in Group 2, we found that the relative location of the transverse-sigmoid sinus junction to the asterion, the superior nuchal line, and the posterior edge of the mastoid process exhibited a high degree of individual variation. Retrosigmoid craniotomy standardized according to anatomic landmarks raises the risk for sinus injury because of variations in their location. We offer our 3D computed tomographic imaging-based procedure as a useful device for the planning of safer retrosigmoid craniotomies.

  15. An original acquisition chain for the TOHR High Resolution Tomograph

    International Nuclear Information System (INIS)

    Pinot, Laurent

    1999-01-01

    The framework of this work is part of a new approach of emission tomography adapted to small animals. The principle of our tomographic system TOHR (French acronym for High Resolution Tomograph) is based on the use of large solid angle and high resolution focusing collimators each mounted in front of a detection module of high efficiency. With a first-generation acquisition chain we were able to characterize TOHR, however, to take fully advantage of the TOHR possibilities, a completely new acquisition scheme had to be designed. This system, being the main topic of this work, makes use of temporal information. The detection of a particle that entered the detector is translated into temporal logical signals. These signals pass into a time coding circuitry and the coded results are transferred in a digital processor. According to the initial terms of delivery, the developed acquisition chain steers the detection of events dependent on the deposited energy and time of arrival. The latter is done by coincidence measurements. All elements are mounted on a special board included into a PC unit and a dedicated program controls the whole system. First experiments showed up the interest of the new acquisition unit for other application in physics or medical imaging

  16. 21 CFR 884.6190 - Assisted reproductive microscopes and microscope accessories.

    Science.gov (United States)

    2010-04-01

    ... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OBSTETRICAL AND GYNECOLOGICAL DEVICES Assisted Reproduction.... Assisted reproduction microscopes and microscope accessories (excluding microscope stage warmers, which are classified under assisted reproduction accessories) are optical instruments used to enlarge images of gametes...

  17. Shear Brillouin light scattering microscope.

    Science.gov (United States)

    Kim, Moonseok; Besner, Sebastien; Ramier, Antoine; Kwok, Sheldon J J; An, Jeesoo; Scarcelli, Giuliano; Yun, Seok Hyun

    2016-01-11

    Brillouin spectroscopy has been used to characterize shear acoustic phonons in materials. However, conventional instruments had slow acquisition times over 10 min per 1 mW of input optical power, and they required two objective lenses to form a 90° scattering geometry necessary for polarization coupling by shear phonons. Here, we demonstrate a confocal Brillouin microscope capable of detecting both shear and longitudinal phonons with improved speeds and with a single objective lens. Brillouin scattering spectra were measured from polycarbonate, fused quartz, and borosilicate in 1-10 s at an optical power level of 10 mW. The elastic constants, phonon mean free path and the ratio of the Pockels coefficients were determined at microscopic resolution.

  18. Differential magnetic force microscope imaging.

    Science.gov (United States)

    Wang, Ying; Wang, Zuobin; Liu, Jinyun; Hou, Liwei

    2015-01-01

    This paper presents a method for differential magnetic force microscope imaging based on a two-pass scanning procedure to extract differential magnetic forces and eliminate or significantly reduce background forces with reversed tip magnetization. In the work, the difference of two scanned images with reversed tip magnetization was used to express the local magnetic forces. The magnetic sample was first scanned with a low lift distance between the MFM tip and the sample surface, and the magnetization direction of the probe was then changed after the first scan to perform the second scan. The differential magnetic force image was obtained through the subtraction of the two images from the two scans. The theoretical and experimental results have shown that the proposed method for differential magnetic force microscope imaging is able to reduce the effect of background or environment interference forces, and offers an improved image contrast and signal to noise ratio (SNR). © Wiley Periodicals, Inc.

  19. Infrared up-conversion microscope

    DEFF Research Database (Denmark)

    2014-01-01

    There is presented an up-conversion infrared microscope (110) arranged for imaging an associated object (130), wherein the up-conversion infrared microscope (110) comprises a non-linear crystal (120) arranged for up-conversion of infrared electromagnetic radiation, and wherein an objective optical...... component (100) has an entrance pupil with a first diameter D1, and an optical component system which is arranged for forming an external image (136) of the back-focal plane (132) of the objective optical component (100), which has a diameter (given by the diameter of a circle enclosing all optical paths...... at the plane of the 10 external image) which is denominated D2 and wherein D1 is larger than a second diameter D2....

  20. Paraquat-poisoning in the rabbit lungs: high resolution computed tomographic findings and pathologic correlation

    International Nuclear Information System (INIS)

    Lee, Kyung Soo; Kim, Eui Han; Lee, Byoung Ho; Kim, Kun Sang

    1992-01-01

    The authors evaluated high resolution computed tomographic (HRCT) findings of the isolated rabbit lungs with paraquat poisoning, and the findings were correlated with pathologic specimens. The purposes of this study are 1) to obtain the HRCT findings of the normal rabbit lung. 2) to find out if pulmonary pathology can be induced in rabbits by paraquat, and 3) to correlate the HRCT findings to those of pathology. Thirty rabbits were divided into three groups: group I included four control rabbits; group II included 16 rabbits given paraquat intraperitoneally (IP group); and group III included 10 rabbits given paraquat intravenously (IV group). The rabbits were sacrificed seven, 10, and 14 days after injection of various amount of paraquat, and then the lungs were isolated for HRCT and pathologic studies. Gross and microscopic findings of the three groups of control and paraquat-injected rabbit lungs were correlated with HRCT findings. Pulmonary congestion, mild thickening of alveolar walls and septae, and multifocal micro-atelectasis were the man pathologic findings of the lungs in both groups of the rabbits. Pulmonary hemorrhage was noted in five (31%) of 16 rabbits of IP group and three (30%) of 10 IV group. Pulmonary edema was seen in one rabbits (6%) of IP and four (40%) of IV group. Typical pulmonary fibrosis was seen in one rabbit of IP (6%) and IV (10%) group, respectively. There was no correlation between the amount of paraquat and frequency of the pulmonary pathology. Pulmonary fibrosis was seen at least one week after the paraquat injection. On HRCT, pulmonary hemorrhage and edema appeared as diffuse air-space consolidation and pulmonary fibrosis as linear or band-like opacities. However, minimal changes such as mild congestion

  1. Computational diffraction tomographic microscopy with transport of intensity equation using a light-emitting diode array

    Science.gov (United States)

    Li, Jiaji; Chen, Qian; Zhang, Jialin; Zuo, Chao

    2017-10-01

    Optical diffraction tomography (ODT) is an effective label-free technique for quantitatively refractive index imaging, which enables long-term monitoring of the internal three-dimensional (3D) structures and molecular composition of biological cells with minimal perturbation. However, existing optical tomographic methods generally rely on interferometric configuration for phase measurement and sophisticated mechanical systems for sample rotation or beam scanning. Thereby, the measurement is suspect to phase error coming from the coherent speckle, environmental vibrations, and mechanical error during data acquisition process. To overcome these limitations, we present a new ODT technique based on non-interferometric phase retrieval and programmable illumination emitting from a light-emitting diode (LED) array. The experimental system is built based on a traditional bright field microscope, with the light source replaced by a programmable LED array, which provides angle-variable quasi-monochromatic illumination with an angular coverage of +/-37 degrees in both x and y directions (corresponding to an illumination numerical aperture of ˜ 0.6). Transport of intensity equation (TIE) is utilized to recover the phase at different illumination angles, and the refractive index distribution is reconstructed based on the ODT framework under first Rytov approximation. The missing-cone problem in ODT is addressed by using the iterative non-negative constraint algorithm, and the misalignment of the LED array is further numerically corrected to improve the accuracy of refractive index quantification. Experiments on polystyrene beads and thick biological specimens show that the proposed approach allows accurate refractive index reconstruction while greatly reduced the system complexity and environmental sensitivity compared to conventional interferometric ODT approaches.

  2. Duties to Extraterrestrial Microscopic Organisms

    Science.gov (United States)

    Cockell, C. S.

    Formulating a normative axiology for the treatment of extraterrestrial microscopic organisms, should they ever be found, requires an extension of environmental ethics to beyond the Earth. Using an ethical framework for the treatment of terrestrial micro-organisms, this paper elaborates a similar ethic for the treatment of extraterrestrial microscopic organisms. An ethic of `teloempathy' allows for the moral considerability of any organism that has `interests', based on rudimentary qualities of conativism, and therefore allows for an identical treatment of all life, related or not related to life on Earth. Although, according to this ethic, individual extraterrestrial microscopic organisms have a good of their own and even `rights', at this level the ethic can only be theoretical, allowing for the inevitable destruction of many individual organisms during the course of human exploratory missions, similarly to the daily destruction of microbes by humans on Earth. A holistic teloempathy, an operative ethic, not only provides a framework for human exploration, but it also has important implications for planetary protection and proposals to implement planetary-scale atmospheric alterations on other bodies. Even prior to the discovery of extraterrestrial life, or the discovery of a complete absence of such life, this exercise yields important insights into the moral philosophy that guides our treatment of terrestrial micro-organisms.

  3. Literature survey on microscopic friction modeling

    NARCIS (Netherlands)

    Hol, J.

    2010-01-01

    To better understand contact and friction conditions, experimental and theoretical studies have been performed in order to take microscopic dependencies into account. Friction is developed on microscopic level by adhesion between contacting asperities, the ploughing effect between asperities and the

  4. Tomographic PIV measurements in a turbulent lifted jet flame

    Science.gov (United States)

    Weinkauff, J.; Michaelis, D.; Dreizler, A.; Böhm, B.

    2013-12-01

    Measurements of instantaneous volumetric flow fields are required for an improved understanding of turbulent flames. In non-reacting flows, tomographic particle image velocimetry (TPIV) is an established method for three-dimensional (3D) flow measurements. In flames, the reconstruction of the particles location becomes challenging due to a locally varying index of refraction causing beam-steering. This work presents TPIV measurements within a turbulent lifted non-premixed methane jet flame. Solid seeding particles were used to provide the 3D flow field in the vicinity of the flame base, including unburned and burned regions. Four cameras were arranged in a horizontal plane around the jet flame. Following an iterative volumetric self-calibration procedure, the remaining disparity caused by the flame was less than 0.2 pixels. Comparisons with conventional two-component PIV in terms of mean and rms values provided additional confidence in the TPIV measurements.

  5. Multidetector computed tomographic imaging of Erdheim-Chester disease.

    Science.gov (United States)

    Yuceler, Zeyneb; Kantarci, Mecit; Karabulut, Nevzat; Ogul, Hayri; Bayraktutan, Ummugulsum; Akman, Canan

    2014-06-01

    Erdheim-Chester disease is a rarely reported disease that can affect nearly every organ and chiefly infiltrates the connective, perivascular, and adipose tissue. The disease is a form of non-Langerhans-cell histiocytosis characterized by the proliferation of foamy histiocytes; its cardiovascular complications carry a severe prognosis. We present the case of a 29-year-old woman who was admitted for analysis of her angina. Our evaluation with use of cardiac multidetector computed tomographic angiography revealed large mediastinal soft tissue that compressed the patient's left anterior descending coronary artery. To our knowledge, this is the first report of the use of low-dose, dual-source, 256-slice multidetector computed tomography to characterize Erdheim-Chester disease that exclusively caused angina and stenosis of a coronary artery in a young adult.

  6. Computed tomographic angiography of the liver via the coeliac axis

    Energy Technology Data Exchange (ETDEWEB)

    Lundstedt, C.; Goetberg, S.; Lunderquist, A.; Stridbeck, H.; Ekberg, H.

    Sixty computed tomographic angiographic (CTA) examinations of the liver were performed with contrast injection into the coeliac axis. Data from both an arterial and a portal venous phase were recorded. In 41 patients it was possible to compare the results of CTA with palpation of the liver during laparotomy. The results from CTA and laparotomy were the same in 35 patients (85%). In one patient CTA disclosed verified liver lesions not diagnosed at laparotomy. There were 2 false negative and 3 false positive CTA examinations. In the remaining 19 patients, a clinical follow-up period of at least 6 months was used to evaluate the results of CTA. In the 7 patients in whom CTA showed benign lesions or a normal liver parenchyma, the clinical follow-up revealed to evidence of tumour growth in the liver.

  7. The development of a compact positron tomograph for prostate imaging

    Energy Technology Data Exchange (ETDEWEB)

    Huber, Jennifer S.; Qi, Jinyi; Derenzo, Stephen E.; Moses, William W.; Huesman, Ronald H.; Budinger, Thomas F.

    2002-12-17

    We give design details and expected image results of a compact positron tomograph designed for prostate imaging that centers a patient between a pair of external curved detector banks (ellipse: 45 cm minor, 70 cm major axis). The bottom bank is fixed below the patient bed, and the top bank moves upward for patient access and downward for maximum sensitivity. Each bank is composed of two rows (axially) of 20 CTI PET Systems HR+ block detectors, forming two arcs that can be tilted to minimize attenuation. Compared to a conventional PET system, our camera uses about one-quarter the number of detectors and has almost two times higher solid angle coverage for a central point source, because the detectors are close to the patient. The detectors are read out by modified CTI HRRT data acquisition electronics. The individual detectors are angled in the plane to point towards the prostate to minimize reso

  8. Tomographic techniques for the study of exceptionally preserved fossils

    Science.gov (United States)

    Sutton, Mark D

    2008-01-01

    Three-dimensional fossils, especially those preserving soft-part anatomy, are a rich source of palaeontological information; they can, however, be difficult to work with. Imaging of serial planes through an object (tomography) allows study of both the inside and outside of three-dimensional fossils. Tomography may be performed using physical grinding or sawing coupled with photography, through optical techniques of serial focusing, or using a variety of scanning technologies such as neutron tomography, magnetic resonance imaging and most usefully X-ray computed tomography. This latter technique is applicable at a variety of scales, and when combined with a synchrotron X-ray source can produce very high-quality data that may be augmented by phase-contrast information to enhance contrast. Tomographic data can be visualized in several ways, the most effective of which is the production of isosurface-based ‘virtual fossils’ that can be manipulated and dissected interactively. PMID:18426749

  9. Computer tomographic and angiographic studies of histologically confirmed intrahepatic masses

    Energy Technology Data Exchange (ETDEWEB)

    Janson, R.; Lackner, K.; Paquet, K.J.; Thelen, M.; Thurn, P.

    1980-06-01

    The computer tomographic and angiographic findings in 53 patients with intrahepatic masses were compared. The histological findings show that 17 were due to echinococcus, 12 were due to hepatic carcinoma, ten were metastases, five patients had focal nodular hyperplasia, three an alveolar echinococcus and there were three cases with an haemangioma of the liver and a further three liver abscesses. Computer tomography proved superior in peripherally situated lesions, and in those in the left lobe of the liver. Arteriography was better at demonstrating lesions below 2 cm in size, particularly vascular tumours. As a pre-operative measure, angiography is to be preferred since it is able to demonstrate anatomic anomalies and variations in the blood supply, as well as invasion of the portal vein or of the inferior vena cava.

  10. Combination tomographic and cardiographic ultrasonic imaging method and system

    International Nuclear Information System (INIS)

    Yano, T.; Fukukita, H.; Fukumoto, A.; Hayakawa, Y.; Irioka, K.

    1984-01-01

    Ultrasonic echo signals are successively sampled and converted to digital echo data which are written into a first digital memory column by column and then read out row by row into a first buffer memory. The digital echo data which are derived in response to beams successively transmitted in a predetermined direction are written into columns of a second digital memory and read out of the memory in rows into a second buffer memory. The data stored in the first and second buffer memories are read out for digital-to-analog conversion and selectively applied within a television ''frame'' interval to control electron beam intensity of a single cathode ray tube so as to present tomographic and cardiographic images in different display areas of the tube

  11. 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.

  12. Detectability in the presence of computed tomographic reconstruction noise

    International Nuclear Information System (INIS)

    Hanson, K.M.

    1977-01-01

    The multitude of commercial computed tomographic (CT) scanners which have recently been introduced for use in diagnostic radiology has given rise to a need to compare these different machines in terms of image quality and dose to the patient. It is therefore desirable to arrive at a figure of merit for a CT image which gives a measure of the diagnostic efficacy of that image. This figure of merit may well be dependent upon the specific visual task being performed. It is clearly important that the capabilities and deficiencies of the human observer as well as the interface between man and machine, namely the viewing system, be taken into account in formulating the figure of merit. Since the CT reconstruction is the result of computer processing, it is possible to use this processing to alter the characteristics of the displayed images. This image processing may improve or degrade the figure of merit

  13. A maximum entropy reconstruction technique for tomographic particle image velocimetry

    International Nuclear Information System (INIS)

    Bilsky, A V; Lozhkin, V A; Markovich, D M; Tokarev, M P

    2013-01-01

    This paper studies a novel approach for reducing tomographic PIV computational complexity. The proposed approach is an algebraic reconstruction technique, termed MENT (maximum entropy). This technique computes the three-dimensional light intensity distribution several times faster than SMART, using at least ten times less memory. Additionally, the reconstruction quality remains nearly the same as with SMART. This paper presents the theoretical computation performance comparison for MENT, SMART and MART, followed by validation using synthetic particle images. Both the theoretical assessment and validation of synthetic images demonstrate significant computational time reduction. The data processing accuracy of MENT was compared to that of SMART in a slot jet experiment. A comparison of the average velocity profiles shows a high level of agreement between the results obtained with MENT and those obtained with SMART. (paper)

  14. Portable tomographic PIV measurements of swimming shelled Antarctic pteropods

    Science.gov (United States)

    Adhikari, Deepak; Webster, Donald R.; Yen, Jeannette

    2016-12-01

    A portable tomographic particle image velocimetry (tomographic PIV) system is described. The system was successfully deployed in Antarctica to study shelled Antarctic pteropods ( Limacina helicina antarctica)—a delicate organism with an unusual propulsion mechanism. The experimental setup consists of a free-standing frame assembled with optical rails, thus avoiding the need for heavy and bulky equipment (e.g. an optical table). The cameras, lasers, optics, and tanks are all rigidly supported within the frame assembly. The results indicate that the pteropods flap their parapodia (or "wings") downward during both power and recovery strokes, which is facilitated by the pitching of their shell. Shell pitching significantly alters the flapping trajectory, allowing the pteropod to move vertically and/or horizontally. The pronation and supination of the parapodia, together with the figure-eight motion during flapping, suggest similarities with insect flight. The volumetric velocity field surrounding the freely swimming pteropod reveals the generation of an attached vortex ring connecting the leading-edge vortex to the trailing-edge vortex during power stroke and a presence of a leading-edge vortex during recovery stroke. These vortex structures play a major role in accelerating the organism vertically and indicate that forces generated on the parapodia during flapping constitute both lift and drag. After completing each stroke, two vortex rings are shed into the wake of the pteropod. The complex combination of body kinematics (parapodia flapping, shell pitch, sawtooth trajectory), flow structures, and resulting force balance may be significantly altered by thinning of the pteropod shell, thus making pteropods an indicator of the detrimental effects of ocean acidification.

  15. On the regularization for nonlinear tomographic absorption spectroscopy

    Science.gov (United States)

    Dai, Jinghang; Yu, Tao; Xu, Lijun; Cai, Weiwei

    2018-02-01

    Tomographic absorption spectroscopy (TAS) has attracted increased research efforts recently due to the development in both hardware and new imaging concepts such as nonlinear tomography and compressed sensing. Nonlinear TAS is one of the emerging modality that bases on the concept of nonlinear tomography and has been successfully demonstrated both numerically and experimentally. However, all the previous demonstrations were realized using only two orthogonal projections simply for ease of implementation. In this work, we examine the performance of nonlinear TAS using other beam arrangements and test the effectiveness of the beam optimization technique that has been developed for linear TAS. In addition, so far only smoothness prior has been adopted and applied in nonlinear TAS. Nevertheless, there are also other useful priors such as sparseness and model-based prior which have not been investigated yet. This work aims to show how these priors can be implemented and included in the reconstruction process. Regularization through Bayesian formulation will be introduced specifically for this purpose, and a method for the determination of a proper regularization factor will be proposed. The comparative studies performed with different beam arrangements and regularization schemes on a few representative phantoms suggest that the beam optimization method developed for linear TAS also works for the nonlinear counterpart and the regularization scheme should be selected properly according to the available a priori information under specific application scenarios so as to achieve the best reconstruction fidelity. Though this work is conducted under the context of nonlinear TAS, it can also provide useful insights for other tomographic modalities. © 2017 Elsevier Ltd.

  16. Diagnostic accuracy of multi-slice computed tomographic angiography in the detection of cerebral aneurysms

    International Nuclear Information System (INIS)

    Haghighatkhah, H. R.; Sabouri, S.; Borzouyeh, F.; Bagherzadeh, M. H.; Bakhshandeh, H.; Jalali, A. H.

    2008-01-01

    Multislice computed tomographic angiography is a rapid and minimally invasive method for the detection of intracranial aneurysms. The purpose of this study was to compare Multislice computed tomographic angiography with digital subtraction angiography In the diagnosis of cerebral aneurysms. Patients and Methods: In this cross sectional study we evaluated 111 consecutive patients [42(37.8%) male and 69(62.2%) female], who were admitted under clinical symptoms and signs. suggestive of harboring an intracranial aneurysm by using a four detector Multislice computed tomographic angiography. Then we compared results of Multislice computed tomographic angiography with digital subtraction angiography results as a gold standard method. Digital subtraction angiography was performed by bilateral selective common carotid artery injections and either unilateral or bilateral vertebral artery injections, as necessary. Multislice computed tomographic angiography images were interpreted by one radiologist and digital subtraction angiography was performed by another radiologist who was blinded to the interpretation of the Multislice computed tomographic angiograms. Results: The mean ±S D age of the patients was 49.1±13.6 years (range: 12-84 years). We performed Multislice computed tomographic in 111 and digital subtraction angiography in 85 patients. The sensitivity, specificity, positive predictive value, negative predictive value, positive and negative likelihood ratio of Multislice computed tomographic angiography, when compared with digital subtraction angiography as the gold standard, were 100%, 90%, 87.5%, 100%, 10 and 0, respectively. Conclusion: Multislice computed tomographic angiography seems to be an accurate and noninvasive imaging modality in the diagnosis of intracranial aneurysms

  17. A Student-Built Scanning Tunneling Microscope

    Science.gov (United States)

    Ekkens, Tom

    2015-01-01

    Many introductory and nanotechnology textbooks discuss the operation of various microscopes including atomic force (AFM), scanning tunneling (STM), and scanning electron microscopes (SEM). In a nanotechnology laboratory class, students frequently utilize microscopes to obtain data without a thought about the detailed operation of the tool itself.…

  18. Microscopic Analysis of Activated Sludge. Training Manual.

    Science.gov (United States)

    Office of Water Program Operations (EPA), Cincinnati, OH. National Training and Operational Technology Center.

    This training manual presents material on the use of a compound microscope to analyze microscope communities, present in wastewater treatment processes, for operational control. Course topics include: sampling techniques, sample handling, laboratory analysis, identification of organisms, data interpretation, and use of the compound microscope.…

  19. Construction of a positron emission tomograph with 2.4 mm detectors

    International Nuclear Information System (INIS)

    McIntyre, J.A.; Sprosst, R.L.; Wang, K.

    1986-01-01

    One-quarter of one ring of a positron tomograph has been constructed. The positron annihilation gamma rays are detected by polished plastic scintillators which direct scintillation light by internal reflection to optical fibers for transmission to the photo-multiplier tubes. By viewing each scintillator with four sets of optical fibers, the number of photomultipliers required for an eight ring tomograph with 1024 detectors per ring (2.4 mm wide detectors) can be reduced from 8192 to 288, and the cost of the tomograph reduced accordingly

  20. Microscopic structure for light nuclei

    International Nuclear Information System (INIS)

    Sharma, V.K.

    1995-01-01

    The microscopic structure for light nuclei e.g. 4 He, 7 Li and 8 Be is considered in the frame work of the generator coordinate method (GCM). The physical interpretation of our GCM is also discussed. The GC amplitudes are used to calculate the various properties like charge and magnetic RMS radii, form factors, electromagnetic moments, astrophysical S-factor, Bremsstrahlung weighted cross sections, relative wavefunctions and vertex functions etc. All the calculated quantities agree well with the values determined experimentally. (author). 30 refs., 10 figs., 2 tabs

  1. Microscopic structure of liquid hydrogen

    CERN Document Server

    Zoppi, M

    2003-01-01

    Hydrogen makes the simplest molecular liquid. Nonetheless, due to several different reasons, measuring its microscopic structure has been one of the most challenging tasks in neutron diffraction experiments. The recent development of modern pulsed neutron sources triggered a renewed experimental interest which, in turn, led to new knowledge and also to a more effective use of the classic reactor-based experimental data. The contemporary development of quantum mechanical computer simulation techniques, and a critical comparison among the results of different experiments using steady and pulsed neutron sources, resulted in a quantitatively reliable solution of the problem. (topical review)

  2. X-ray microscopes at BESSY II

    International Nuclear Information System (INIS)

    Guttmann, P.; Niemann, B.; Thieme, J.; Wiesemann, U.; Rudolph, D.; Schmahl, G.

    2000-01-01

    The undulator U41 at BESSY II will be used as source for X-ray microscopes. An overview of the X-ray microscopy area is presented. After finishing the construction phase a transmission X-ray microscope, a scanning transmission X-ray microscope and an X-ray test chamber will be available. The transmission X-ray microscope will allow investigations with high lateral resolution at moderate energy resolution while the scanning transmission X-ray microscope will allow high energy resolution at moderate lateral resolution of the same specimen

  3. Wolter x-ray microscope calibration

    International Nuclear Information System (INIS)

    Gerassimenko, M.

    1986-01-01

    A 22 x Wolter microscope was calibrated after several months of operation in the Lawrence Livermore National Laboratory (LLNL) Inertial Confinement Fusion program. Placing a point x-ray source at the microscope focus, I recorded the image plane spectrum, as well as the direct spectrum, and from the ratio of these two spectra derived an accurate estimate of the microscope solid angle in the 1-4 keV range. The solid angle was also calculated using the microscope geometry and composition. Comparison of this calculated value with the solid angle that was actually measured suggests contamination of the microscope surface

  4. Wolter x-ray microscope calibration

    International Nuclear Information System (INIS)

    Gerassimenko, M.

    1986-06-01

    A 22 x Wolter microscope was calibrated after several months of operation in the Lawrence Livermore National laboratory (LLNL) Inertial Confinement Fusion program. Placing a point x-ray source at the microscope focus, I recorded the image plane spectrum, as well as the direct spectrum, and from the ratio of these two spectra derived an accurate estimate of the microscope solid angle in the 1 to 4 keV range. The solid angle was also calculated using the microscope geometry and composition. Comparison of this calculated value with the solid angle that was actually measured suggests contamination of the microscope surface

  5. The illumination characteristics of operative microscopes.

    Science.gov (United States)

    Schutt, Christopher A; Redding, Brandon; Cao, Hui; Michaelides, Elias

    2015-01-01

    Modern operative microscopes use light sources which possess the power to severely damage underlying tissue. Currently, manufacturers provide a safety warning of this possibility. However, they are unable to suggest specific settings due to a stated "lack of scientific publications on this topic". We aim to radiometrically evaluate multiple otologic microscopes at variables which effect irradiance in order to determine reference emissions levels and provide guidelines for improved intraoperative safety. The optical radiance of four otologic microscopes was evaluated at variable field illumination sizes (spot size), intensity settings and working distances. The spectral emission of each microscope was separately measured. The energy absorbed in skin with representative properties was then calculated as a function of time for each microscope by accounting for the emission spectrum of the microscope and the absorption spectrum of skin. Microscopes showed a wide range of optical radiance based on model, spots size, intensity setting and working distances. Spectral emission of all four microscopes was centered in the visible spectrum with minimal ultraviolet or infrared contribution. A large amount of energy is absorbed by skin during usage of operative microscopes. The highest calculated absorption at 200 min of use was 736.26 J/cm(2). Operative microscopes have the ability to cause patient morbidity secondary to the energy they impart. In an effort to decrease potential injury we recommend that physicians be aware of their microscopes properties and how to control variables which effect irradiance of the skin. Published by Elsevier Inc.

  6. Robotic autopositioning of the operating microscope.

    Science.gov (United States)

    Oppenlander, Mark E; Chowdhry, Shakeel A; Merkl, Brandon; Hattendorf, Guido M; Nakaji, Peter; Spetzler, Robert F

    2014-06-01

    Use of the operating microscope has become pervasive since its introduction to the neurosurgical world. Neuronavigation fused with the operating microscope has allowed accurate correlation of the focal point of the microscope and its location on the downloaded imaging study. However, the robotic ability of the Pentero microscope has not been utilized to orient the angle of the microscope or to change its focal length to hone in on a predefined target. To report a novel technology that allows automatic positioning of the operating microscope onto a set target and utilization of a planned trajectory, either determined with the StealthStation S7 by using preoperative imaging or intraoperatively with the microscope. By utilizing the current motorized capabilities of the Zeiss OPMI Pentero microscope, a robotic autopositioning feature was developed in collaboration with Surgical Technologies, Medtronic, Inc. (StealthStation S7). The system is currently being tested at the Barrow Neurological Institute. Three options were developed for automatically positioning the microscope: AutoLock Current Point, Align Parallel to Plan, and Point to Plan Target. These options allow the microscope to pivot around the lesion, hover in a set plane parallel to the determined trajectory, or rotate and point to a set target point, respectively. Integration of automatic microscope positioning into the operative workflow has potential to increase operative efficacy and safety. This technology is best suited for precise trajectories and entry points into deep-seated lesions.

  7. Microscopical advances in assisted reproduction.

    Science.gov (United States)

    Baccetti, B

    2004-01-01

    In a series of papers carried out by this laboratory it was demonstrated that the quality of sterile males sperm, assessed submicroscopically and mathematically, is closely correlated with the success of the various procedures of assisted reproduction. If we attempt to select hypothetically optimal spermatozoa destined to the ICSI by light inverted microscopy, a considerable amount of ultrastructural information is lost and our selection is merely based on the motility. In this study we apply polarization microscopy to the ICSI technique, introducing polarizing and analyzing lenses in an inverted microscope model, operating in a transparent container. The retardation of the birefringence in the various organelles is evaluated by compensators, and the images are transmitted to a video system, and stored in a computer. Spermatozoa are maintained alive and perfectly motile in this polarizing inverted microscope, and the character of the birefringence is the same as in fixed and sectioned biological material examined by polarization microscopy. The birefringence of the sperm structures allows a sperm analysis closer to TEM than to phase contrast light microscopy analysis.

  8. Correlative Fluorescence and Electron Microscopy in 3D-Scanning Electron Microscope Perspective.

    Science.gov (United States)

    Franks, Jonathan; Wallace, Callen T; Shibata, Masateru; Suga, Mitsuo; Erdman, Natasha; Stolz, Donna B; Watkins, Simon C

    2017-04-03

    The ability to correlate fluorescence microscopy (FM) and electron microscopy (EM) data obtained on biological (cell and tissue) specimens is essential to bridge the resolution gap between the data obtained by these different imaging techniques. In the past such correlations were limited to either EM navigation in two dimensions to the locations previously highlighted by fluorescence markers, or subsequent high-resolution acquisition of tomographic information using a TEM. We present a novel approach whereby a sample previously investigated by FM is embedded and subjected to sequential mechanical polishing and backscatter imaging by scanning electron microscope. The resulting three dimensional EM tomogram of the sample can be directly correlated to the FM data. © 2017 by John Wiley & Sons, Inc. Copyright © 2017 John Wiley & Sons, Inc.

  9. Development of basic software for processing and visualization of NMR tomographic images

    International Nuclear Information System (INIS)

    Traina, A.J.M.; Slaets, J.F.W.

    1989-01-01

    The present work describes the software under development for Image Processing and Visualization of MR Images. This project is part of Magnetic Ressonance Tomographic System which is being built at the IFQSC - USP [pt

  10. Impact of dynamic computed tomographic angiography on endograft sizing for endovascular aneurysm repair.

    NARCIS (Netherlands)

    Pol, J.A.; Truijers, M.; Vliet, J.A. van der; Fillinger, M.F.; Marra, S.P.; Renema, W.K.J.; Oostveen, L.J.; Schultze Kool, L.J.; Blankensteijn, J.D.

    2009-01-01

    PURPOSE: To quantify dynamic changes in aortoiliac dimensions using dynamic electrocardiographically (ECG)-gated computed tomographic angiography (CTA) and to investigate any potential impact on preoperative endograft sizing in relation to observer variability. METHODS: Dynamic ECG-gated CTA was

  11. Linear adaptive noise-reduction filters for tomographic imaging: Optimizing for minimum mean square error

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Winston Y. [Univ. of California, Berkeley, CA (United States)

    1993-04-01

    This thesis solves the problem of finding the optimal linear noise-reduction filter for linear tomographic image reconstruction. The optimization is data dependent and results in minimizing the mean-square error of the reconstructed image. The error is defined as the difference between the result and the best possible reconstruction. Applications for the optimal filter include reconstructions of positron emission tomographic (PET), X-ray computed tomographic, single-photon emission tomographic, and nuclear magnetic resonance imaging. Using high resolution PET as an example, the optimal filter is derived and presented for the convolution backprojection, Moore-Penrose pseudoinverse, and the natural-pixel basis set reconstruction methods. Simulations and experimental results are presented for the convolution backprojection method.

  12. IceBridge Radar L3 Tomographic Ice Thickness V001

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains Level-3 tomographic ice thickness measurements derived from data captured by the Center for Remote Sensing of Ice Sheets (CReSIS) Multichannel...

  13. Helicopter parameter extraction using joint Time-Frequency and Tomographic Techniques

    CSIR Research Space (South Africa)

    Cilliers, A

    2008-09-01

    Full Text Available A technique based on time-frequency and tomographic analysis to extract helicopter blade parameters for the purposes of radar non-cooperative target recognition (NCTR) is investigated. The proposed algorithm shows that (under certain conditions...

  14. Blunt oesophageal perforation: treatment with surgical exclusion and percutaneous drainage under computed tomographic guidance

    International Nuclear Information System (INIS)

    Vauthey, J.N.; Lerut, J.; Laube, M.; Gertsch, P.

    1992-01-01

    We report a patient with a left thoracic contusion and rupture of the distal oesophagus. Persistent sepsis developed after oesophageal exclusion without closure. Two collection were drained percutaneously under computed tomographic guidance and the sepsis resolved. (11 refs., 1 fig.)

  15. Visual servoing in medical robotics: a survey. Part II: tomographic imaging modalities--techniques and applications.

    Science.gov (United States)

    Azizian, Mahdi; Najmaei, Nima; Khoshnam, Mahta; Patel, Rajni

    2015-03-01

    Intraoperative application of tomographic imaging techniques provides a means of visual servoing for objects beneath the surface of organs. The focus of this survey is on therapeutic and diagnostic medical applications where tomographic imaging is used in visual servoing. To this end, a comprehensive search of the electronic databases was completed for the period 2000-2013. Existing techniques and products are categorized and studied, based on the imaging modality and their medical applications. This part complements Part I of the survey, which covers visual servoing techniques using endoscopic imaging and direct vision. The main challenges in using visual servoing based on tomographic images have been identified. 'Supervised automation of medical robotics' is found to be a major trend in this field and ultrasound is the most commonly used tomographic modality for visual servoing. Copyright © 2014 John Wiley & Sons, Ltd.

  16. Application of tomographic particle image velocimetry to studies of transport in complex (dusty) plasma

    International Nuclear Information System (INIS)

    Williams, Jeremiah D.

    2011-01-01

    Over the past twelve years, two-dimensional and stereoscopic particle image velocimetry (PIV) techniques have been used to obtain detailed measurements of the thermal and transport properties of the microparticle component of dusty plasma systems. This letter reports on an extension of these techniques to obtain a volumetric, three-dimensional velocity vector measurement using tomographic PIV. Initial measurements using the tomographic PIV diagnostic are presented.

  17. Tomographic diffractive microscopy with agile illuminations for imaging targets in a noisy background.

    Science.gov (United States)

    Zhang, T; Godavarthi, C; Chaumet, P C; Maire, G; Giovannini, H; Talneau, A; Prada, C; Sentenac, A; Belkebir, K

    2015-02-15

    Tomographic diffractive microscopy is a marker-free optical digital imaging technique in which three-dimensional samples are reconstructed from a set of holograms recorded under different angles of incidence. We show experimentally that, by processing the holograms with singular value decomposition, it is possible to image objects in a noisy background that are invisible with classical wide-field microscopy and conventional tomographic reconstruction procedure. The targets can be further characterized with a selective quantitative inversion.

  18. Development of a computerized tomographic system based on the FAN-BEAM technique

    International Nuclear Information System (INIS)

    Junqueira, M.M.; Santos, C.A.C.; Borges, J.C.

    1986-01-01

    The Nuclear Instrumentation Laboratory, at COPPE/UFRJ, concentrates its researches in the development of computerized tomographic systems, looking for applications in industrial and medical non destructive analysing techniques. In this work we have projected and constructed a tomographic prototype, based on the FAN-BEAM technique for irradiating the object under analysis. An algorithm previously developed to analyse parallel beams, was modified and adapted to the FAN-BEAM geometry. (Author) [pt

  19. Remote diagnosis via a telecommunication satellite--ultrasonic tomographic image transmission experiments.

    Science.gov (United States)

    Nakajima, I; Inokuchi, S; Tajima, T; Takahashi, T

    1985-04-01

    An experiment to transmit ultrasonic tomographic section images required for remote medical diagnosis and care was conducted using the mobile telecommunication satellite OSCAR-10. The images received showed the intestinal condition of a patient incapable of verbal communication, however the image screen had a fairly coarse particle structure. On the basis of these experiments, were considered as the transmission of ultrasonic tomographic images extremely effective in remote diagnosis.

  20. Tomographic surveys for mineral exploration using complex resistivity method

    Science.gov (United States)

    Son, J.; Park, S.; Kim, J.

    2011-12-01

    Complex resistive method is a kind of induced polarization (IP) method which all the measurement is made in frequency domain. It transmits the current with the specified frequency through current electrodes, and measure the amplitude and phase to the transmitted current at receiver electrodes. It is also called SIP (Spectral IP) method when multi-frequency measurements are involved. Our research group has been developing the methodology and interpretation technique for SIP survey for several years, and already developed 2/3D inversion algorithms and extended them to the simultaneous inversion of multi-frequency IP data. Recently we are developing mining evaluation technique by relating the inverted property of field IP data to the measured one in the laboratory through geo-statistical relationship. L1-norm inversion using IRLS (iterative reweighted least squares) method is introduced to overcome the problem of noise sensitive characteristics of complex resistivity data, especially in phase data and effectively applied to the field data. The L1-norm inversion improves the noise characteristics of complex resistivity survey. However complex resistivity method is used only for the surface survey because it require special electrode like porous pot and layout of cables to minimize the interference between transmitters and receivers. In this study, we applied complex resistivity method to the tomographic survey using boreholes and interpret data using L1-norm inversion technique to verify applicability without special electrode and layout of cables. Survey was done for the boreholes drilled in the tunnel for prospecting possible mineralized zone. Zeta system based on GDP multi-function receiver manufactured by Zonge was used in this survey and tomographic data measurement was made for two frequencies, 0.25 and 1 Hz. 30 electrodes respectively for two boreholes, a total of 60 electrodes were used in this survey and electrode spacing was 10 meter. Quality of measured data

  1. Motion tracking-enhanced MART for tomographic PIV

    International Nuclear Information System (INIS)

    Novara, Matteo; Scarano, Fulvio; Batenburg, Kees Joost

    2010-01-01

    A novel technique to increase the accuracy of multiplicative algebraic reconstruction technique (MART) reconstruction from tomographic particle image velocimetry (PIV) recordings at higher seeding density than currently possible is presented. The motion tracking enhancement (MTE) method is based on the combined utilization of images from two or more exposures to enhance the reconstruction of individual intensity fields. The working principle is first introduced qualitatively, and the mathematical background is given that explains how the MART reconstruction can be improved on the basis of an improved first guess object obtained from the combination of non-simultaneous views reduced to the same time instant deforming the 3D objects by an estimate of the particle motion field. The performances of MTE are quantitatively evaluated by numerical simulation of the imaging, reconstruction and image correlation processes. The cases of two or more exposures obtained from time-resolved experiments are considered. The iterative application of MTE appears to significantly improve the reconstruction quality, first by decreasing the intensity of the ghost images and second, by increasing the intensity and the reconstruction precision for the actual particles. Based on computer simulations, the maximum imaged seeding density that can be dealt with is tripled with respect to the MART analysis applied to a single exposure. The analysis also illustrates that the maximum effect of the MTE method is comparable to that of doubling the number of cameras in the tomographic system. Experiments performed on a transitional jet at Re = 5000 apply the MTE method to double-frame recordings. The velocity measurement precision is increased for a system with fewer views (two or three cameras compared with four cameras). The ghost particles' intensity is also visibly reduced although to a lesser extent with respect to the computer simulations. The velocity and vorticity field obtained from a three

  2. 3D flame topography obtained by tomographic chemiluminescence with direct comparison to planar Mie scattering measurements.

    Science.gov (United States)

    Xu, Wenjiang; Wickersham, A J; Wu, Yue; He, Fan; Ma, Lin

    2015-03-20

    This work reports the measurements of 3D flame topography using tomographic chemiluminescence and its validation by direct comparison against planar Mie scattering measurements. Tomographic measurements of the 3D topography of various well-controlled laboratory flames were performed using projections measured by seven cameras, and a simultaneous Mie scattering measurement was performed to measure a 2D cross section of the 3D flame topography. The tomographic measurements were based on chemiluminescence emissions from the flame, and the Mie scattering measurements were based on micrometer-size oil droplets seeded into the flow. The flame topography derived from the 3D tomographic and the Mie scattering measurement was then directly compared. The results show that the flame topography obtained from tomographic chemiluminescence and the Mie measurement agreed qualitatively (i.e., both methods yielded the same profile of the flame fronts), but a quantitative difference on the order of millimeters was observed between these two methods. These results are expected to be useful for understanding the capabilities and limitations of the 3D tomographic and Mie scattering techniques in combustion diagnostics.

  3. A positron emission tomograph designed for 3/4 mm resolution

    International Nuclear Information System (INIS)

    McInytre, J.A.; Allen, R.D.; Aguiar, J.; Paulson, J.T.

    1995-01-01

    Two factors of the design for a positron tomograph affect the magnitude of the tomograph spatial resolution: the gamma ray detector width and the analogue measurement of the scintillator location. In the tomograph design reported here the analogue measurement is eliminated and the detector transaxial width factor is reduced to 3/4 mm. The analogue measurement is eliminated by transmitting the scintillation light from each individual scintillator through optical fibers to four photo-multipliers (PMT's); the identities of the PMT's then provide a digital address for the scintillation location. Plastic scintillators are used to provide enough scintillation light for transmission through the optical fibers. Bonuses from the use of plastic scintillators are first, the reduction of the scintillator dead time to about 10 nsec, second, a large reduction of cross-talk between neighboring scintillators, third, the reduction of resolution loss from off-axis gamma rays and, fourth, the ability to sample the axial image at one-eighth the axial resolution distance of 2.5 mm. The designed tomograph incorporates 20 rings. Two of the 32 tomograph 20-ring modules have been constructed to measure the resolution and other characteristics of the tomographs

  4. Investigation of liquid water in gas diffusion layers of polymer electrolyte fuel cells using X-ray tomographic microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Flueckiger, Reto [Electrochemistry Laboratory, Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Marone, Federica [Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Stampanoni, Marco [Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Institute for Biomedical Engineering, University and ETH Zurich, Gloriastrasse 35, CH-8092 Zurich (Switzerland); Wokaun, Alexander [Electrochemistry Laboratory, Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Buechi, Felix N., E-mail: felix.buechi@psi.c [Electrochemistry Laboratory, Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland)

    2011-02-01

    In polymer electrolyte fuel cells (PEFCs), condensation of water within the pore network of the gas diffusion layers (GDL) can influence the gas transport properties and thus reduce the electrochemical conversion rates. The use of X-ray tomographic microscopy (XTM), which allows for a resolution in the order of one micrometer is investigated for studying ex situ the local saturation in GDL's. The strength of XTM is the high spatial resolution with simultaneous contrast for water and carbon, allowing for non-destructive 3D-imaging of the solid and the contained water. The application of this method for imaging the ex situ water intrusion into the porous network of GDLs is explored using absorption and phase contrast methods. It is shown that the inhomogeneous filling behavior of GDL materials can indeed be visualized with sufficient resolution. For Toray paper TGP-H-060 the local saturation was measured as function of the water pressure. The results, evaluated in 1D, 2D and 3D show a liquid water retention effect at the denser layers near the surface. A comparison with established capillary pressure functions is presented. Altogether, the results show the potential of the XTM-method as a tool for studying the liquid water behavior in PEFC on a microscopic scale.

  5. Investigation of liquid water in gas diffusion layers of polymer electrolyte fuel cells using X-ray tomographic microscopy

    International Nuclear Information System (INIS)

    Flueckiger, Reto; Marone, Federica; Stampanoni, Marco; Wokaun, Alexander; Buechi, Felix N.

    2011-01-01

    In polymer electrolyte fuel cells (PEFCs), condensation of water within the pore network of the gas diffusion layers (GDL) can influence the gas transport properties and thus reduce the electrochemical conversion rates. The use of X-ray tomographic microscopy (XTM), which allows for a resolution in the order of one micrometer is investigated for studying ex situ the local saturation in GDL's. The strength of XTM is the high spatial resolution with simultaneous contrast for water and carbon, allowing for non-destructive 3D-imaging of the solid and the contained water. The application of this method for imaging the ex situ water intrusion into the porous network of GDLs is explored using absorption and phase contrast methods. It is shown that the inhomogeneous filling behavior of GDL materials can indeed be visualized with sufficient resolution. For Toray paper TGP-H-060 the local saturation was measured as function of the water pressure. The results, evaluated in 1D, 2D and 3D show a liquid water retention effect at the denser layers near the surface. A comparison with established capillary pressure functions is presented. Altogether, the results show the potential of the XTM-method as a tool for studying the liquid water behavior in PEFC on a microscopic scale.

  6. Exceptionally preserved Cambrian trilobite digestive system revealed in 3D by synchrotron-radiation X-ray tomographic microscopy.

    Directory of Open Access Journals (Sweden)

    Mats E Eriksson

    Full Text Available The Cambrian 'Orsten' fauna comprises exceptionally preserved and phosphatised microscopic arthropods. The external morphology of these fossils is well known, but their internal soft-tissue anatomy has remained virtually unknown. Here, we report the first non-biomineralised tissues from a juvenile polymerid trilobite, represented by digestive structures, glands, and connective strands harboured in a hypostome from the Swedish 'Orsten' fauna. Synchrotron-radiation X-ray tomographic microscopy enabled three-dimensional internal recordings at sub-micrometre resolution. The specimen provides the first unambiguous evidence for a J-shaped anterior gut and the presence of a crop with a constricted alimentary tract in the Trilobita. Moreover, the gut is Y-shaped in cross section, probably due to a collapsed lumen of that shape, another feature which has not previously been observed in trilobites. The combination of anatomical features suggests that the trilobite hypostome is functionally analogous to the labrum of euarthropods and that it was a sophisticated element closely integrated with the digestive system. This study also briefly addresses the preservational bias of the 'Orsten' fauna, particularly the near-absence of polymerid trilobites, and the taphonomy of the soft-tissue-harbouring hypostome.

  7. Design of a transmission electron positron microscope

    International Nuclear Information System (INIS)

    Doyama, Masao; Inoue, M.; Kogure, Y.; Hayashi, Y.; Yoshii, T.; Kurihara, T.; Tsuno, K.

    2003-01-01

    This paper reports the plans and design of positron-electron microscopes being built at KEK (High Energy Accelerator Research Organization), Tsukuba, Japan. A used electron microscope is altered. The kinetic energies of positrons produced by accelerators or by nuclear decays are not a unique value but show a spread over in a wide range. Positron beam is guided to a transmission electron microscope (JEM100SX). Positrons are moderated by a tungsten foil, are accelerated and are focused on a nickel sheet. The monochromatic focused beam is injected into an electron microscope. The focusing and aberration of positrons are the same as electrons in a magnetic system which are used in commercial electron microscopes. Imaging plates are used to record positron images for the transmission electron microscope. (author)

  8. Pediatric computed tomographic angiography: imaging the cardiovascular system gently.

    Science.gov (United States)

    Hellinger, Jeffrey C; Pena, Andres; Poon, Michael; Chan, Frandics P; Epelman, Monica

    2010-03-01

    Whether congenital or acquired, timely recognition and management of disease is imperative, as hemodynamic alterations in blood flow, tissue perfusion, and cellular oxygenation can have profound effects on organ function, growth and development, and quality of life for the pediatric patient. Ensuring safe computed tomographic angiography (CTA) practice and "gentle" pediatric imaging requires the cardiovascular imager to have sound understanding of CTA advantages, limitations, and appropriate indications as well as strong working knowledge of acquisition principles and image post processing. From this vantage point, CTA can be used as a useful adjunct along with the other modalities. This article presents a summary of dose reduction CTA methodologies along with techniques the authors have employed in clinical practice to achieve low-dose and ultralow-dose exposure in pediatric CTA. CTA technical principles are discussed with an emphasis on the low-dose methodologies and safe contrast medium delivery strategies. Recommended parameters for currently available multidetector-row computed tomography scanners are summarized alongside recommended radiation and contrast medium parameters. In the second part of the article an overview of pediatric CTA clinical applications is presented, illustrating low-dose and ultra-low dose techniques, with an emphasis on the specific protocols. Copyright 2010 Elsevier Inc. All rights reserved.

  9. Tomographic and pathological findings of crazy-paving pattern

    Energy Technology Data Exchange (ETDEWEB)

    Vabo, Karen Amaral do; Damato, Simone Duarte [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Dept. of Radiology

    2011-07-15

    Objective: To describe high-resolution computed tomography findings in several diseases that run their course with the 'crazy-paving' pattern. Materials and Methods: The present study has evaluated seven patients with diagnoses of alveolar proteinosis, bronchioloalveolar carcinoma, lipoid pneumonia and pneumocystosis, correlating tomographic and pathological findings. Results: In the cases of pneumocystosis, the alveolar spaces were filled with foamy material where parasitic organisms intermingled with surfactants, fibrin and cell debris were observed. In the cases of bronchioloalveolar carcinoma, the septa were thickened by associated fibrosis or lymphangitis, with the alveolar walls internally lined with tumor cells, and production of mucus. In the patient with alveolar proteinosis, the septa were thickened by edema, with alveolar filling determined by lipoprotein. In the patient with mineral oil aspiration, the histopathological findings included alveolar septa thickening caused by cell proliferation, with presence of fat vacuoles in alveolar septa. Conclusion: The crazy-paving pattern offers a wide range of differential diagnoses and must be evaluated in conjunction with clinical findings. (author)

  10. Computed tomographic appearances of the pelvis following hindquarter amputation.

    Science.gov (United States)

    Fowler, J; Davies, A M; Carter, S R; Grimer, R J; Sneath, R S

    1992-12-01

    Bilateral and midline symmetry of the normal pelvic anatomy is an aid to the interpretation of computed tomographic (CT) examinations. Following hindquarter amputation (HQA) or partial hemipelvectomy (PHP) the normal anatomical relationships are disturbed. The CT examinations of 15 patients who had undergone either an HQA or a PHP for an advanced musculoskeletal malignancy are reviewed. The new "normal" anatomy revealed displacement of the bladder and small bowel to the side of surgery in one third of patients, more commonly in the PHP cases. There were varying degrees of wasting of the ipsilateral musculature, gluteus maximus muscle flap, erector spinae and psoas muscles, etc., because of partial denervation and disruption of their origin or insertion. Recurrent tumour was identified in eight of 10 cases in which it was clinically suspected prior to the CT examination. Invariably the recurrence arose within the muscle flap at the resection margin. Bone involvement by direct tumour spread was present in three cases. Pitfalls in differentiating recurrent tumour from scar tissue are discussed.

  11. Strategies for source space limitation in tomographic inverse procedures

    Energy Technology Data Exchange (ETDEWEB)

    George, J.S.; Lewis, P.S.; Schlitt, H.A.; Kaplan, L.; Gorodnitsky, I.; Wood, C.C.

    1994-02-01

    The use of magnetic recordings for localization of neural activity requires the solution of an ill-posed inverse problem: i.e. the determination of the spatial configuration, orientation, and timecourse of the currents that give rise to a particular observed field distribution. In its general form, this inverse problem has no unique solution; due to superposition and the existence of silent source configurations, a particular magnetic field distribution at the head surface could be produced by any number of possible source configurations. However, by making assumptions concerning the number and properties of neural sources, it is possible to use numerical minimization techniques to determine the source model parameters that best account for the experimental observations while satisfying numerical or physical criteria. In this paper the authors describe progress on the development and validation of inverse procedures that produce distributed estimates of neuronal currents. The goal is to produce a temporal sequence of 3-D tomographic reconstructions of the spatial patterns of neural activation. Such approaches have a number of advantages, in principle. Because they do not require estimates of model order and parameter values (beyond specification of the source space), they minimize the influence of investigator decisions and are suitable for automated analyses. These techniques also allow localization of sources that are not point-like; experimental studies of cognitive processes and of spontaneous brain activity are likely to require distributed source models.

  12. Optimization and Application of Surface Segmentation Technique for Tomographic PIV

    Science.gov (United States)

    Ding, Liuyang; Adrian, Ronald; Wilson, Brandon; Prestridge, Kathy; Team

    2014-11-01

    Tomographic PIV is a widely used 3D flow measurement technique. It utilizes images recorded by multiple cameras to reconstruct the intensity distribution of a measured volume. The 3D3C velocity field is then computed by 3D cross-correlation. Surface segmentation aims to reduce computational cost. It extracts from a cloud of particles an image of those particles that lie on a mathematically prescribed surface. 2D2C velocity fields are computed on stacks of orthogonal surfaces, then assembled to construct the full 3D3C velocity field. We investigate the reconstruction of adaptive surfaces aligned with the main flow direction minimizing the out-of-plane motion. Numerical assessment is performed on curved-surface reconstruction for Taylor-Couette flow. An optimizing 2D interrogation scheme involving volumetric deformation is proposed to improve the accuracy of the 3D3C velocity field. The numerical test is performed on a synthetic vortex ring showing good measurement accuracy. Experimental results measuring the shock-driven turbulent mixing will also be presented. References

  13. Linear analysis of rotationally invariant, radially variant tomographic imaging systems

    International Nuclear Information System (INIS)

    Huesmann, R.H.

    1990-01-01

    This paper describes a method to analyze the linear imaging characteristics of rotationally invariant, radially variant tomographic imaging systems using singular value decomposition (SVD). When the projection measurements from such a system are assumed to be samples from independent and identically distributed multi-normal random variables, the best estimate of the emission intensity is given by the unweighted least squares estimator. The noise amplification of this estimator is inversely proportional to the singular values of the normal matrix used to model projection and backprojection. After choosing an acceptable noise amplification, the new method can determine the number of parameters and hence the number of pixels that should be estimated from data acquired from an existing system with a fixed number of angles and projection bins. Conversely, for the design of a new system, the number of angles and projection bins necessary for a given number of pixels and noise amplification can be determined. In general, computing the SVD of the projection normal matrix has cubic computational complexity. However, the projection normal matrix for this class of rotationally invariant, radially variant systems has a block circulant form. A fast parallel algorithm to compute the SVD of this block circulant matrix makes the singular value analysis practical by asymptotically reducing the computation complexity of the method by a multiplicative factor equal to the number of angles squared

  14. Method of making tomographic images of X-rayed objects

    International Nuclear Information System (INIS)

    Eickel, R.

    1979-01-01

    A tomographic image of a selected layer of a stationary object is made by moving the source of X-rays along a first path at one side of the selected layer and by moving an ionography imaging chamber which contains a dielectric receptor sheet along a second path at the other side of the selected layer. The movement of the sheet is synchronized with movement of the source of X-rays and includes a translatory movement in a direction counter to the direction of movement of the source, a pivotal movement to maintain the sheet in a plane which is normal to the central beam of the bundle of X-rays, and a sidewise movement to vary the distance between the selected layer and the sheet so that the length of the projection of selected layer upon the sheet remains unchanged. If the sheet is rectangular, the pivotal movement is performed about an axis which is located in the plane of the selected layer and is parallel to the shorter sides of the sheet

  15. Brain computed tomographic findings in post-cardiopulmonary resuscitation patients

    International Nuclear Information System (INIS)

    Ishida, Tsuguharu; Yoshinaga, Kazumasa; Horibe, Takashi; Kokubu, Kiyokazu; Kokura, Yoshihiro; Matsui, Konosuke; Inamoto, Kazuo.

    1986-01-01

    We retrospectively assessed the brain computed tomographic (CT) findings in 22 post-cardiopulmonary resuscitation (CPR) patients excluding neonatal cases. On the basis of the CT findings, the patients were divided into two groups. Eight patients (36.4 %) had bilateral abnormal lowdensity areas in the basal ganglia (Group I). The remaining 14 patients (63.6 %) had no abnormalities in that area (Group II). In Group I, the incidence of primary cardiac arrest and duration of advanced life support (ALS) was significantly different (p < 0.05) from Group II. Sex, age, duration of basic life support (BLS), time elapsed from initiation of BLS to initial CT and from initiation of ALS to initial CT was not significantly different between the two groups. Outcome was very poor in both groups and no significant difference was noted between them. We conclude that primary cardiac arrest and long duration of ALS were predictors of abnormal bilateral low-density areas in the basal ganglia in post-CPR patients. However, their appearance was not related to outcome. (author)

  16. Double Colorectal Cancer Only Diagnosed by Computed Tomographic Colonography

    Directory of Open Access Journals (Sweden)

    Koichi Nagata

    2008-02-01

    Full Text Available A 58-year-old woman presented to her physician with rectal bleeding and intermittent diarrhea. Optical colonoscopy revealed a bulky tumor which was diagnosed as rectal cancer. She was referred to our institution for further evaluation and treatment. Slim optical colonoscopy showed an obstructive cancer in the rectosigmoid junction and no information of the proximal side of the obstruction. The patient then underwent computed tomographic (CT colonography for further evaluation of the proximal side. Three-dimensional endoluminal ‘fly-through’ images revealed another protruded lesion in the proximal side of the obstruction. Diagnosis of synchronous double cancer was made by CT colonography. This CT data was not only used to create three-dimensional images but also to decide on a preoperative clinical staging. Laparoscopy-assisted high anterior resection was performed and T3 rectal cancer and T1 sigmoid colon cancer were confirmed in the resected specimen. Follow-up optical colonoscopy revealed no other tumors. CT colonography has recently become a popular preoperative examination tool with significant improvement in quality of image due to a rapid progress in computer technology. CT colonography correctly showed synchronous double cancer in our case and provided crucial information for planning surgery. We recommend that CT colonography should be used for evaluating the proximal side of obstructive colorectal cancer.

  17. Tomographic Particle Image Velocimetry using Smartphones and Colored Shadows

    KAUST Repository

    Aguirre-Pablo, Andres A.

    2017-06-12

    We demonstrate the viability of using four low-cost smartphone cameras to perform Tomographic PIV. We use colored shadows to imprint two or three different time-steps on the same image. The back-lighting is accomplished with three sets of differently-colored pulsed LEDs. Each set of Red, Green & Blue LEDs is shone on a diffuser screen facing each of the cameras. We thereby record the RGB-colored shadows of opaque suspended particles, rather than the conventionally used scattered light. We subsequently separate the RGB color channels, to represent the separate times, with preprocessing to minimize noise and cross-talk. We use commercially available Tomo-PIV software for the calibration, 3-D particle reconstruction and particle-field correlations, to obtain all three velocity components in a volume. Acceleration estimations can be done thanks to the triple pulse illumination. Our test flow is a vortex ring produced by forcing flow through a circular orifice, using a flexible membrane, which is driven by a pressurized air pulse. Our system is compared to a commercial stereoscopic PIV system for error estimations. We believe this proof of concept experiment will make this technique available for education, industry and scientists for a fraction of the hardware cost needed for traditional Tomo-PIV.

  18. Computed tomographic appearance of primary lung tumors in dogs.

    Science.gov (United States)

    Marolf, Angela J; Gibbons, Debra S; Podell, Brendan K; Park, Richard D

    2011-01-01

    Canine primary lung tumors typically appear radiographically as a well-circumscribed solitary mass in the periphery of a caudal lung lobe. Consolidated and diffuse forms of primary lung tumors have also been described. Nineteen dogs with computed tomographic (CT) images of the thorax and a histological diagnosis of primary lung tumor (17 primary carcinomas and two primary sarcomas) were evaluated retrospectively to characterize the CT findings. All primary lung tumors were bronchocentric in origin with internal air bronchograms. The bronchi were typically narrowed, displaced, and often obstructed by the tumor. Eighteen of 19 (95%) of the tumors were solitary and there was one pneumonic/alveolar form. Most solitary tumors were well circumscribed (17/18), located in the central to periphery of the lung (14/18), and in a cranial or caudal lobe (16/19). Most primary lung tumors (11/17) had mild to moderate heterogeneous contrast enhancement. Five of 19 dogs (26%) had evidence of pulmonary metastasis. Internal mineralization (3/19) and tracheobronchial lymphadenopathy (4/19) were also identified. On CT examination, solitary, well circumscribed, bronchocentric masses with internal air bronchograms are consistent with a primary pulmonary tumor in dogs. © 2010 Veterinary Radiology & Ultrasound.

  19. Computerized tomographic studies in cerebral palsy. Analysis of 200 cases

    Energy Technology Data Exchange (ETDEWEB)

    Sugie, Y. (Tokyo Women' s Medical Coll. (Japan))

    1981-09-01

    Computed tomographic (CT) findings in 200 children with cerebral palsy (CP) were analysed from the viewpoint of clinical manifestations, disease complications and etiological factors. CT scans of 135 cases (67.5%) were found to be abnormal and there were 14 (7%) borderline cases. The major abnormality found on CT scans was cerebral atrophy. Other important changes included focal or diffuse low density area in the brain tissue, congenital malformation, and cerebellar atrophy. From the clinical point of view, a large number of patients with spastic tetraplegia and spastic diplegia showed highly abnormal CT scans. On the other hand, in patients with spastic monoplegia, spastic paraplegia, and athetotic type, CT findings were normal or revealed only minor cerebral atrophy. Most children showing asymmetric clinical symptoms had corresponding asymmetric CT abnormalities which included ventricular enlargement, low density area in the brain tissue, and hemispherical volume. There was a significant correlation between the severity of physical impairment and the extent of CT abnormalities. Severely affected children had grossly abnormal CT scans such as hydranencephaly, polycystic change, and extensive cerebral atrophy. In the patients complicated with epilepsy, the incidence and severity of abnormal CT were higher than those of non-epileptic patients. Mentally retarded patients had variable enlargement of the subarachnoidal space depending on the severity of their mental retardation. Patients with suspected postnatal etiology also had high incidence of severe CT abnormality. CT scan is a valuable tool for evaluating patients with CP and in some cases, possible etiology of the disease may be discovered.

  20. Tomographic Particle Image Velocimetry using Smartphones and Colored Shadows.

    Science.gov (United States)

    Aguirre-Pablo, Andres A; Alarfaj, Meshal K; Li, Er Qiang; Hernández-Sánchez, J F; Thoroddsen, Sigurdur T

    2017-06-16

    We demonstrate the viability of using four low-cost smartphone cameras to perform Tomographic PIV. We use colored shadows to imprint two or three different time-steps on the same image. The back-lighting is accomplished with three sets of differently-colored pulsed LEDs. Each set of Red, Green & Blue LEDs is shone on a diffuser screen facing each of the cameras. We thereby record the RGB-colored shadows of opaque suspended particles, rather than the conventionally used scattered light. We subsequently separate the RGB color channels, to represent the separate times, with preprocessing to minimize noise and cross-talk. We use commercially available Tomo-PIV software for the calibration, 3-D particle reconstruction and particle-field correlations, to obtain all three velocity components in a volume. Acceleration estimations can be done thanks to the triple pulse illumination. Our test flow is a vortex ring produced by forcing flow through a circular orifice, using a flexible membrane, which is driven by a pressurized air pulse. Our system is compared to a commercial stereoscopic PIV system for error estimations. We believe this proof of concept experiment will make this technique available for education, industry and scientists for a fraction of the hardware cost needed for traditional Tomo-PIV.

  1. The research of clinical application of computed tomographic virtual gastroscopy

    International Nuclear Information System (INIS)

    Zhang Lei; Pan Zhenyu; Zhai Xiaoli; Gu Hua; Wang Yajie; Ding Yi; Wang Li; Liang Ying; Zhai Renyou

    2000-01-01

    Objective: To investigate the values, methods and findings of computed tomographic virtual gastroscopy (CTVG). Methods: Sixty-nine patients underwent the examination of spiral CT after charged air into stomachs in different cubage. The CT scan conditions were collimating width 3 mm, pitch 1.2 - 2.5, scanning speed 0.8 s/360 degree, the raw data of CT volume scan was reconstructed in overlapping rate 33% - 67%. Then the images of CTVG were built using navigator software (GE AG, USA). Results: The accuracy, sensitivity, and specificity of CTVG were 92.8%, 96.4%, and 78.6%, respectively. CTVG corresponded well with fibrous gastroscopy and specimens in demonstrating the gastric lesions. CTVG was provided with the ability of revealing the tiny lesions of chronic atrophic gastritis, chronic erosive gastritis, chronic proliferative gastritis, and acute hemorrhagic gastritis in some degree. The high quality imaging of CTVG could be obtained in condition of collimating width 3 mm, pitch 1.2 - 1.5, overlapping 50% - 67%, well hold-breath, gastric cubage in full and feasible scan positions. Conclusion: CTVG is a rising means of gastric examination and has great value in clinic applications

  2. Conceptual design of a compact positron tomograph for prostateimaging

    Energy Technology Data Exchange (ETDEWEB)

    Huber, J.S.; Derenzo, S.E.; Qi, J.; Moses, W.W.; Huesman, R.H.; Budinger, T.F.

    2000-11-04

    We present a conceptual design of a compact positron tomograph for prostate imaging using a pair of external curved detector banks, one placed above and one below the patient. The lower detector bank is fixed below the patient bed, and the top bank adjusts vertically for maximum sensitivity and patient access. Each bank is composed of 40conventional block detectors, forming two arcs (44 cm minor, 60 cm major axis) that are tilted to minimize attenuation and positioned as close as possible to the patient to improve sensitivity. The individual detectors are angled to point towards the prostate to minimize resolution degradation in that region. Inter-plane septa extend 5 cm beyond the scintillator crystals to reduce random and scatter backgrounds. A patient is not fully encircled by detector rings in order to minimize cost,causing incomplete sampling due to the side gaps. Monte Carlo simulation (including random and scatter) demonstrates the feasibility of detecting a spherical tumor of 2.5 cm diameter with a tumor to background ratio of2:1, utilizing the number of events that should be achievable with a6-minute scan after a 10 mCi injection (e.g., carbon-11 choline or fluorine-18 fluorocholine).

  3. Tomographic reconstruction of structures using a novel GPR system

    Science.gov (United States)

    Fedeli, Alessandro; Ježová, Jana; Lambot, Sébastien; Pastorino, Matteo; Randazzo, Andrea; Pajewski, Lara

    2017-04-01

    The ever growing range of applications of ground penetrating radar (GPR) motivates the need of developing efficient measurement systems combined with effective data processing methods. On the one hand, advanced GPR measurement systems require to accurately model the physical effects occurring between the antenna structure and the medium. On the other hand, the GPR device should provide a reliable reconstruction of the properties of the targets under an inspection to a common user. In this work, a novel GPR system was tested for the imaging of buried structures. First of all, the acquired experimental data were pre-processed with a proper calibration technique for removing antenna effects. After that, a reconstruction of a hidden structure was obtained by means of both qualitative and quantitative electromagnetic inverse scattering methods. In particular, while the qualitative techniques aim at reconstructing only specific features of the targets (e.g., location, shape), the proposed quantitative method has the challenging goal of the complete electromagnetic characterization of the buried structures. The performance of the new system was evaluated in different operating conditions with promising results. Acknowledgment This work benefited from the networking activities within the EU funded COST Action TU1208, "Civil Engineering Applications of Ground Penetrating Radar". Part of this work was carried out during the Short-Term Scientific Mission STSM-TU1208-34990 "Testing of a new lightweight radar system for tomographical reconstruction of circular structures" (Alessandro Fedeli, Italy, visiting Prof. Sébastien Lambot, Belgium).

  4. Synchrotron X-ray tomographic microscopy of fossil embryos.

    Science.gov (United States)

    Donoghue, Philip C J; Bengtson, Stefan; Dong, Xi-ping; Gostling, Neil J; Huldtgren, Therese; Cunningham, John A; Yin, Chongyu; Yue, Zhao; Peng, Fan; Stampanoni, Marco

    2006-08-10

    Fossilized embryos from the late Neoproterozoic and earliest Phanerozoic have caused much excitement because they preserve the earliest stages of embryology of animals that represent the initial diversification of metazoans. However, the potential of this material has not been fully realized because of reliance on traditional, non-destructive methods that allow analysis of exposed surfaces only, and destructive methods that preserve only a single two-dimensional view of the interior of the specimen. Here, we have applied synchrotron-radiation X-ray tomographic microscopy (SRXTM), obtaining complete three-dimensional recordings at submicrometre resolution. The embryos are preserved by early diagenetic impregnation and encrustation with calcium phosphate, and differences in X-ray attenuation provide information about the distribution of these two diagenetic phases. Three-dimensional visualization of blastomere arrangement and diagenetic cement in cleavage embryos resolves outstanding questions about their nature, including the identity of the columnar blastomeres. The anterior and posterior anatomy of embryos of the bilaterian worm-like Markuelia confirms its position as a scalidophoran, providing new insights into body-plan assembly among constituent phyla. The structure of the developing germ band in another bilaterian, Pseudooides, indicates a unique mode of germ-band development. SRXTM provides a method of non-invasive analysis that rivals the resolution achieved even by destructive methods, probing the very limits of fossilization and providing insight into embryology during the emergence of metazoan phyla.

  5. Tuberculosis of the Parotid Gland: Computed Tomographic Findings

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Y.; Xiao, J.; Pui, M.H.; Gong, Q. (Dept. of Radiology, West China Hospital, Sichuan Univ., Sichuan (China))

    2008-05-15

    Background: Tuberculosis (TB) of the parotid gland is rare, even in endemic regions. Approximately 100 cases have been reported in the English literature. The computed tomographic (CT) features, however, have seldom been studied. Purpose: To determine the diagnostic CT features of tuberculosis of the parotid gland. Material and Methods: CT studies of four histologically proven cases of tuberculosis of the parotid gland were retrospectively reviewed. Results: A total of 15 enlarged lymph nodes were found in the superficial lobes of the parotid glands. The nodes were arranged linearly within the gland. Enhancement patterns included homogeneous enhancement (9/15, 60%), homogeneous enhancement with eccentric microcysts (3/15, 20%), and thick-walled rim enhancement with central lucency (3/15, 20%). Thickened adjacent fascial plane and platysma were seen in two patients. Ipsilateral cervical lymphadenopathy was seen in all patients. Conclusion: In patients presenting with unilateral parotid nodules, TB should be considered when linearly arranged enhancing nodules are demonstrated in the superficial lobes of the glands on CT scan

  6. Predictors of incomplete optical colonoscopy using computed tomographic colonography.

    Science.gov (United States)

    Sachdeva, Reetika; Tsai, Salina D; El Zein, Mohamad H; Tieu, Alan A; Abdelgelil, Ahmed; Besharati, Sepideh; Khashab, Mouen A; Kalloo, Anthony N; Kumbhari, Vivek

    2016-01-01

    Optical colonoscopy (OC) is the primary modality for investigation of colonic pathology. Although there is data on demographic factors for incomplete OC, paucity of data exists for anatomic variables that are associated with an incomplete OC. These anatomic variables can be visualized using computed tomographic colonography (CTC). We aim to retrospectively identify variables associated with incomplete OC using CTC and develop a scoring method to predict the outcome of OC. In this case-control study, 70 cases ( with incomplete OC) and 70 controls (with complete OC) were identified. CTC images of cases and controls were independently reviewed by a single CTC radiologist. Demographic and anatomical parameters were recorded. Data was examined using descriptive linear statistics and multivariate logistic regression model. On analysis, female gender (80% vs 58.6% P = 0.007), prior abdominal/pelvic surgeries (51.4% vs 14.3% P diverticulosis (P = 0.867) with incomplete OC. A scoring system to predict the outcome of OC is proposed based on CTC findings. Female gender, prior surgery, and increasing colonic length and tortuosity were associated with incomplete OC, whereas increasing age and history of severe diverticulosis were not. These factors may be used in the future to predict those patients who are at risk of incomplete OC.

  7. Strategies for source space limitation in tomographic inverse procedures

    International Nuclear Information System (INIS)

    George, J.S.; Lewis, P.S.; Schlitt, H.A.; Kaplan, L.; Gorodnitsky, I.; Wood, C.C.

    1994-01-01

    The use of magnetic recordings for localization of neural activity requires the solution of an ill-posed inverse problem: i.e. the determination of the spatial configuration, orientation, and timecourse of the currents that give rise to a particular observed field distribution. In its general form, this inverse problem has no unique solution; due to superposition and the existence of silent source configurations, a particular magnetic field distribution at the head surface could be produced by any number of possible source configurations. However, by making assumptions concerning the number and properties of neural sources, it is possible to use numerical minimization techniques to determine the source model parameters that best account for the experimental observations while satisfying numerical or physical criteria. In this paper the authors describe progress on the development and validation of inverse procedures that produce distributed estimates of neuronal currents. The goal is to produce a temporal sequence of 3-D tomographic reconstructions of the spatial patterns of neural activation. Such approaches have a number of advantages, in principle. Because they do not require estimates of model order and parameter values (beyond specification of the source space), they minimize the influence of investigator decisions and are suitable for automated analyses. These techniques also allow localization of sources that are not point-like; experimental studies of cognitive processes and of spontaneous brain activity are likely to require distributed source models

  8. On the computed tomographic diagnosis of pulmonary nodules

    International Nuclear Information System (INIS)

    Higashi, Yuuichirou

    1988-01-01

    Computed tomography (CT) was used to examine 53 pulmonary nodules which were considered not definitely calcified on plain radiographs or conventional tomograms. An average CT number was calculate for each lesion. For the primary lung cancers, the average CT number was 36 HU with a standard deviation of 6.6 HU, while the benign lesions had the mean CT number of 69 HU, with a standard deviation of 42.8 HU. The mean CT number separating lung malignancies from benign lesions was 78.8 HU. To evaluate the attenuation values within each nodule, iso-CT value map was obtained by using Siemens therapy planning system, MEVAPLAN. Nodules were classified into five categories, Type I to V. All of three nodules classified as Type IV were benign. Iso-CT value map was effective in establishing the benignancy of nodules. The quantitative computed tomographic analysis of pulmonary nodules was evaluated by dual-energy CT. Dual-energy CT has the potential to eliminate the effect of spectral hardening by use of monoenergic images derived from dual-kV data and to separate high CT numbers due to calcium from those due to high density organic material. (author)

  9. Quantitative analysis of normal thallium-201 tomographic studies

    International Nuclear Information System (INIS)

    Eisner, R.L.; Gober, A.; Cerqueira, M.

    1985-01-01

    To determine the normal (nl) distribution of Tl-201 uptake post exercise (EX) and at redistribution (RD) and nl washout, Tl-201 rotational tomographic (tomo) studies were performed in 40 subjects: 16 angiographic (angio) nls and 24 nl volunteers (12 from Emory and 12 from Yale). Oblique angle short axis slices were subjected to maximal count circumferential profile analysis. Data were displayed as a ''bullseye'' functional map with the apex at the center and base at the periphery. The bullseye was not uniform in all regions because of the variable effects of attenuation and resolution at different view angles. In all studies, the septum: lateral wall ratio was 1.0 in males and approximately equal to 1.0 in females. This occurred predominantly because of anterior defects due to breast soft tissue attenuation. EX and RD bullseyes were similar. Using a bi-exponential model for Tl kinetics, 4 hour normalized washout ranged 49-54% in each group and showed minimal variation between walls throughout the bullseye. Thus, there are well defined variations in Tl-201 uptake in the nl myocardium which must be taken into consideration when analyzing pt data. Because of these defects and the lack of adequate methods for attenuation correction, quantitative analysis of Tl-201 studies must include direct comparison with gender-matched nl data sets

  10. TOMOGRAPHIC SITE CHARACTERIZATION USING CPT, ERT, AND GPR

    Energy Technology Data Exchange (ETDEWEB)

    Rexford M. Morey; Susanne M. Conklin; Stephen P. Farrington, P.E.; James D. Shinn II, P.E.

    1999-07-01

    The US Department of Energy (DOE) is responsible for the cleanup of inactive DOE sites and for bringing DOE sites and facilities into compliance with federal, state, and local laws and regulations. The DOE's Office of Environmental Management (EM) needs advanced technologies that can make environmental restoration and waste management operations more efficient and less costly. These techniques are required to better characterize the physical, hydrogeological, and chemical properties of the subsurface while minimizing and optimizing the use of boreholes and monitoring wells. Today the cone penetrometer technique (CPT) is demonstrating the value of a minimally invasive deployment system for site characterization. Applied Research Associates, Inc. is developing two new sensor packages for site characterization and monitoring. The two new methods are: (1) Electrical Resistivity Tomography (ERT); and (2) Ground Penetrating Radar (GPR) Tomography. These sensor systems are now integrated with the CPT. The results of this program now make it possible to install ERT and GPR units by CPT methods and thereby reduce installation costs and total costs for ERT and GPR surveys. These two techniques can complement each other in regions of low resistivity where ERT is more effective and regions of high resistivity where GPR is more effective. The results show that CPT-installed GeoWells can be used for both ERT and GPR borehole tomographic subsurface imaging. These two imaging techniques can be used for environmental site characterization and monitoring have numerous and diverse applications within site cleanup and waste management operations.

  11. Computed tomographic findings of liver injury in adults

    International Nuclear Information System (INIS)

    Ha, Deok Gi; Lee, Hyeon Kyeong; Lee, Won Jae; Oh, Yeon Hee; Lee, Sung Hee; Yun, Jee Yeong; Lee, Tae Woo; Lee, Sung Woo; Park, Soo Soung

    1994-01-01

    We studied to compare computed tomographic(CT) findings of liver injury with management method in adults and, moreover, to present the CT basis for the management. We retrospectively reviewed CT scans of 43 adults diagnosed as liver injury during a 66 month period. Thirty-eight patients were hemodynamically stable. Thirty-two of them were managed conservatively, whereas six managed operatively. Five unstable patients underwent emergency operation. We classified CT findings according to the severity of liver injuries(ie, hematoma, laceration, and periportal tracking) and hemoperitoneum, ranging from grade 1 to 5 and from 0 to 3 +. respectively. Thus, we compared the CT classifications with their management(ie, operation rate), especially hemodynamically stable patients. Operation rates of all patients and hemodynamically stable patients were 26% and 16%, respectively. Operation rate at each grade of liver injury was low, especially in hemodynamically stable, despite relatively high operation rate in grade 4. Operation rate of 3+ homoperitoneum was 100%, including hemodynamically stable patients, in contrast to otherwise low operation rate of others. Most liver injury in adults, including grade 4, were managed conservatively, especially hemodynamically stable. Though large amount of hemoperitoneum(ie, 3+) required operation, most hemooperitoeum were managed conservatively. Thus, CT findings of liver injury is helpful in the decision for the management method

  12. Quantification of tomographic PIV uncertainty using controlled experimental measurements.

    Science.gov (United States)

    Liu, Ning; Wu, Yue; Ma, Lin

    2018-01-20

    The goal of this work was to experimentally quantify the uncertainty of three-dimensional (3D) and three-component (3C) velocity measurements using tomographic particle image velocimetry (tomo-PIV). Controlled measurements were designed using tracer particles embedded in a solid sample, and tomo-PIV measurements were performed on the sample while it was moved both translationally and rotationally to simulate various known displacement fields, so the 3D3C displacements measured by tomo-PIV can be directly compared to the known displacements created by the sample. The results illustrated that (1) the tomo-PIV technique was able to reconstruct the 3D3C velocity with an averaged error of 0.8-1.4 voxels in terms of magnitude and 1.7°-1.9° in terms of orientation for the velocity fields tested; (2) view registration (VR) plays a significant role in tomo-PIV, and by reducing VR error from 0.6° to 0.1°, the 3D3C measurement accuracy can be improved by at least 2.5 times in terms of both magnitude and orientation; and (3) the use of additional cameras in tomo-PIV can extend the 3D3C velocity measurement to a larger volume, while maintaining acceptable accuracy. These results obtained from controlled tests are expected to aid the error analysis and the design of tomo-PIV measurements.

  13. 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.)

  14. Voxel-based model construction from colored tomographic images

    International Nuclear Information System (INIS)

    Loureiro, Eduardo Cesar de Miranda

    2002-07-01

    This work presents a new approach in the construction of voxel-based phantoms that was implemented to simplify the segmentation process of organs and tissues reducing the time used in this procedure. The segmentation process is performed by painting tomographic images and attributing a different color for each organ or tissue. A voxel-based head and neck phantom was built using this new approach. The way as the data are stored allows an increasing in the performance of the radiation transport code. The program that calculates the radiation transport also works with image files. This capability allows image reconstruction showing isodose areas, under several points of view, increasing the information to the user. Virtual X-ray photographs can also be obtained allowing that studies could be accomplished looking for the radiographic techniques optimization assessing, at the same time, the doses in organs and tissues. The accuracy of the program here presented, called MCvoxEL, that implements this new approach, was tested by comparison to results from two modern and well-supported Monte Carlo codes. Dose conversion factors for parallel X-ray exposure were also calculated. (author)

  15. Testing microscopes between market and scientific strategies

    OpenAIRE

    Ratcliff, Marc

    2007-01-01

    This paper claims that the testing of microscopes during the eighteenth century reveals specific types of interaction between makers and users and links between scientific and economic interests. Basic procedures for the comparison and test of microscopes existed already in the Enlightenment although many historians thought that these were invented during the nineteenth century. The paper discusses three kinds of tests, advertising, the admission of a microscope in the laboratory, and finally...

  16. Calibrated atomic force microscope measurements of vickers hardness indentations and tip production and characterisation for scanning tunelling microscope

    DEFF Research Database (Denmark)

    Jensen, Carsten P.

    Calibrated atomic force microscope measurements of vickers hardness indentations and tip production and characterisation for scanning tunelling microscope......Calibrated atomic force microscope measurements of vickers hardness indentations and tip production and characterisation for scanning tunelling microscope...

  17. Microscopic description of magnetized plasma: quasiparticle concept

    International Nuclear Information System (INIS)

    Sosenko, P.P.; Decyk, V.K.

    1993-01-01

    A quasiparticle concept is developed systematically, from first principles, within the context of microscopic description of magnetized plasma. It is argued that the zeroth velocity-gyroangle harmonic of the microscopic particle distribution function under the gyrokinetic change of variables can be taken as a microscopic quasi-particle density in a reduced phase space. The nature of quasiparticles is discussed and equations of their motion are derived within both exact and reduced microscopic descriptions. The reduced one employs explicitly the separation of interesting time scales. (orig.)

  18. Foldscope: origami-based paper microscope.

    Directory of Open Access Journals (Sweden)

    James S Cybulski

    Full Text Available Here we describe an ultra-low-cost origami-based approach for large-scale manufacturing of microscopes, specifically demonstrating brightfield, darkfield, and fluorescence microscopes. Merging principles of optical design with origami enables high-volume fabrication of microscopes from 2D media. Flexure mechanisms created via folding enable a flat compact design. Structural loops in folded paper provide kinematic constraints as a means for passive self-alignment. This light, rugged instrument can survive harsh field conditions while providing a diversity of imaging capabilities, thus serving wide-ranging applications for cost-effective, portable microscopes in science and education.

  19. A microscope for Fermi gases

    International Nuclear Information System (INIS)

    Omran, Ahmed

    2016-01-01

    This thesis reports on a novel quantum gas microscope to investigate many-body systems of fermionic atoms in optical lattices. Single-site resolved imaging of ultracold lattice gases has enabled powerful studies of bosonic quantum many-body systems. The extension of this capability to Fermi gases offers new prospects to studying complex phenomena of strongly correlated systems, for which numerical simulations are often out of reach. Using standard techniques of laser cooling, optical trapping, and evaporative cooling, ultracold Fermi gases of 6 Li are prepared and loaded into a large-scale 2D optical lattice of flexible geometry. The atomic distribution is frozen using a second, short-scaled lattice, where we perform Raman sideband cooling to induce fluorescence on each atom while maintaining its position. Together with high-resolution imaging, the fluorescence signals allow for reconstructing the initial atom distribution with single-site sensitivity and high fidelity. Magnetically driven evaporative cooling in the plane allows for producing degenerate Fermi gases with almost unity filling in the initial lattice, allowing for the first microscopic studies of ultracold gases with clear signatures of Fermi statistics. By preparing an ensemble of spin-polarised Fermi gases, we detect a flattening of the density profile towards the centre of the cloud, which is a characteristic of a band-insulating state. In one set of experiments, we demonstrate that losses of atom pairs on a single lattice site due to light-assisted collisions are circumvented. The oversampling of the second lattice allows for deterministic separation of the atom pairs into different sites. Compressing a high-density sample in a trap before loading into the lattice leads to many double occupancies of atoms populating different bands, which we can image with no evidence for pairwise losses. We therefore gain direct access to the true number statistics on each lattice site. Using this feature, we can

  20. Preoperative imaging for DIEA perforator flaps: a comparative study of computed tomographic angiography and Doppler ultrasound.

    Science.gov (United States)

    Rozen, Warren M; Phillips, Timothy J; Ashton, Mark W; Stella, Damien L; Gibson, Robert N; Taylor, G Ian

    2008-01-01

    Abdominal donor-site flaps, including the transverse rectus abdominis musculocutaneous (TRAM) and deep inferior epigastric artery (DIEA) perforator flaps, are standard in autologous breast reconstruction. With significant variation in the vascular anatomy of the abdominal wall, preoperative imaging is essential for preoperative planning and reducing intraoperative error. Doppler and color duplex sonography have been used with varying results, and the quest continues for optimal preoperative assessment. Computed tomographic angiography has recently been proposed as a noninvasive modality for this purpose. This is the first study to formally compare preoperative Doppler ultrasound with computed tomographic angiography for imaging the DIEA. Eight consecutive patients undergoing DIEA perforator flap surgery for breast reconstruction underwent both computed tomographic angiography and Doppler ultrasound preoperatively. All investigations and procedures were performed at the same institution with the same primary and assisting surgeons and the same radiology team. Computed tomographic angiography was superior to Doppler ultrasound at identifying the course of the DIEA and its branching pattern, and in visualizing its perforators. Preoperative computed tomographic angiography was highly specific (100 percent) and more sensitive in mapping and visualizing perforators (p = 0.0078). It was also proficient at identifying the superficial epigastric arterial system and for effectively displaying the results intraoperatively. It was substantially quicker and removed the interobserver error associated with Doppler ultrasonography. The study was ceased after eight patients because of the overwhelming benefit of computed tomographic angiography over Doppler ultrasonography. Computed tomographic angiography is a valuable imaging modality for the preoperative assessment of the donor-site vascular supply for TRAM and DIEA perforator flaps.

  1. Scanning Microscopes Using X Rays and Microchannels

    Science.gov (United States)

    Wang, Yu

    2003-01-01

    Scanning microscopes that would be based on microchannel filters and advanced electronic image sensors and that utilize x-ray illumination have been proposed. Because the finest resolution attainable in a microscope is determined by the wavelength of the illumination, the xray illumination in the proposed microscopes would make it possible, in principle, to achieve resolutions of the order of nanometers about a thousand times as fine as the resolution of a visible-light microscope. Heretofore, it has been necessary to use scanning electron microscopes to obtain such fine resolution. In comparison with scanning electron microscopes, the proposed microscopes would likely be smaller, less massive, and less expensive. Moreover, unlike in scanning electron microscopes, it would not be necessary to place specimens under vacuum. The proposed microscopes are closely related to the ones described in several prior NASA Tech Briefs articles; namely, Miniature Microscope Without Lenses (NPO-20218), NASA Tech Briefs, Vol. 22, No. 8 (August 1998), page 43; and Reflective Variants of Miniature Microscope Without Lenses (NPO-20610), NASA Tech Briefs, Vol. 26, No. 9 (September 2002) page 6a. In all of these microscopes, the basic principle of design and operation is the same: The focusing optics of a conventional visible-light microscope are replaced by a combination of a microchannel filter and a charge-coupled-device (CCD) image detector. A microchannel plate containing parallel, microscopic-cross-section holes much longer than they are wide is placed between a specimen and an image sensor, which is typically the CCD. The microchannel plate must be made of a material that absorbs the illuminating radiation reflected or scattered from the specimen. The microchannels must be positioned and dimensioned so that each one is registered with a pixel on the image sensor. Because most of the radiation incident on the microchannel walls becomes absorbed, the radiation that reaches the

  2. Few-View Tomographic Reconstruction of Technetium-99m-Sestamibi Distribution for the Detection and Differentiation of Breast Lesions

    National Research Council Canada - National Science Library

    La

    2000-01-01

    .... Because the time required by tomographic studies to acquire data useful to popular reconstruction algorithms might be excessive for SPECT SMM, we have worked to develop reconstruction algorithms...

  3. Few-View Tomographic Reconstruction of Technetium-99m- sestamibi Distribution for the Detection and Diagnosis of Breast Lesions

    National Research Council Canada - National Science Library

    LaRiviere, Patrick

    1998-01-01

    .... Because the time required by tomographic studies to acquire data useful to popular reconstruction algorithms might be excessive for SPECT SMM, we have worked to develop reconstruction algorithms...

  4. A transmission positron microscope and a scanning positron microscope being built at KEK, Japan

    International Nuclear Information System (INIS)

    Doyama, M.; Inoue, M.; Kogure, Y.; Kurihara, T.; Yagishita, A.; Shidara, T.; Nakahara, K.; Hayashi, Y.; Yoshiie, T.

    2001-01-01

    This paper reports the plans of positron microscopes being built at KEK (High Energy Accelerator Research Organization), Tsukuba, Japan improving used electron microscopes. The kinetic energies of positron produced by accelerators or by nuclear decays have not a unique value but show a spread over in a wide range. Positron beam will be guided near electron microscopes, a transmission electron microscope (JEM100S) and a scanning electron microscope (JSM25S). Positrons are slowed down by a tungsten foil, accelerated and focused on a nickel sheet. The monochromatic focused beam will be injected into an electron microscope. The focusing of positrons and electrons is achieved by magnetic system of the electron microscopes. Imaging plates are used to record positron images for the transmission electron microscope. (orig.)

  5. Spectral Interferometry with Electron Microscopes.

    Science.gov (United States)

    Talebi, Nahid

    2016-09-21

    Interference patterns are not only a defining characteristic of waves, but also have several applications; characterization of coherent processes and holography. Spatial holography with electron waves, has paved the way towards space-resolved characterization of magnetic domains and electrostatic potentials with angstrom spatial resolution. Another impetus in electron microscopy has been introduced by ultrafast electron microscopy which uses pulses of sub-picosecond durations for probing a laser induced excitation of the sample. However, attosecond temporal resolution has not yet been reported, merely due to the statistical distribution of arrival times of electrons at the sample, with respect to the laser time reference. This is however, the very time resolution which will be needed for performing time-frequency analysis. These difficulties are addressed here by proposing a new methodology to improve the synchronization between electron and optical excitations through introducing an efficient electron-driven photon source. We use focused transition radiation of the electron as a pump for the sample. Due to the nature of transition radiation, the process is coherent. This technique allows us to perform spectral interferometry with electron microscopes, with applications in retrieving the phase of electron-induced polarizations and reconstructing dynamics of the induced vector potential.

  6. Hamiltonian mechanics limits microscopic engines

    Science.gov (United States)

    Anglin, James; Gilz, Lukas; Thesing, Eike

    2015-05-01

    We propose a definition of fully microscopic engines (micro-engines) in terms of pure mechanics, without reference to thermodynamics, equilibrium, or cycles imposed by external control, and without invoking ergodic theory. This definition is pragmatically based on the observation that what makes engines useful is energy transport across a large ratio of dynamical time scales. We then prove that classical and quantum mechanics set non-trivial limits-of different kinds-on how much of the energy that a micro-engine extracts from its fuel can be converted into work. Our results are not merely formal; they imply manageable design constraints on micro-engines. They also suggest the novel possibility that thermodynamics does not emerge from mechanics in macroscopic regimes, but rather represents the macroscopic limit of a generalized theory, valid on all scales, which governs the important phenomenon of energy transport across large time scale ratios. We propose experimental realizations of the dynamical mechanisms we identify, with trapped ions and in Bose-Einstein condensates (``motorized bright solitons'').

  7. Mice embryology: a microscopic overview.

    Science.gov (United States)

    Salvadori, Maria Letícia Baptista; Lessa, Thais Borges; Russo, Fabiele Baldino; Fernandes, Renata Avancini; Kfoury, José Roberto; Braga, Patricia Cristina Baleeiro Beltrão; Miglino, Maria Angélica

    2012-10-01

    In this work, we studied the embryology of mice of 12, 14, and 18 days of gestation by gross observation, light microscopy, and scanning electron microscopy. Grossly, the embryos of 12 days were observed in C-shaped region of the brain, eye pigmentation of the retina, first, second, and third pharyngeal arches gill pit nasal region on the fourth ventricle brain, cervical curvature, heart, liver, limb bud thoracic, spinal cord, tail, umbilical cord, and place of the mesonephric ridge. Microscopically, the liver, cardiovascular system and spinal cord were observed. In the embryo of 14 days, we observed structures that make up the liver and heart. At 18 days of gestation fetuses, it was noted the presence of eyes, mouth, and nose in the cephalic region, chest and pelvic region with the presence of well-developed limbs, umbilical cord, and placenta. Scanning electron microscopy in 18 days of gestation fetuses evidenced head, eyes closed eyelids, nose, vibrissae, forelimb, heart, lung, kidney, liver, small bowel, diaphragm, and part of the spine. The results obtained in this work describe the internal and external morphology of mice, provided by an integration of techniques and review of the morphological knowledge of the embryonic development of this species, as this animal is of great importance to scientific studies. Copyright © 2012 Wiley Periodicals, Inc.

  8. Multibeam scanning electron microscope : Experimental results

    NARCIS (Netherlands)

    Mohammadi-Gheidari, A.; Hagen, C.W.; Kruit, P.

    2010-01-01

    The authors present the first results obtained with their multibeam scanning electron microscope. For the first time, they were able to image 196 (array of 14×14) focused beams of a multielectron beam source on a specimen using single beam scanning electron microscope (SEM) optics. The system

  9. Major Components of the Light Microscope

    OpenAIRE

    Centonze Frohlich, Victoria

    2008-01-01

    The light microscope is a basic tool for the cell biologist, who should have a thorough understanding of how it works, how it should be aligned for different applications, and how it should be maintained as required to obtain maximum image-forming capacity and resolution. The components of the microscope are described in detail here.

  10. Major components of the light microscope.

    Science.gov (United States)

    Centonze Frohlich, Victoria

    2008-07-30

    The light microscope is a basic tool for the cell biologist, who should have a thorough understanding of how it works, how it should be aligned for different applications, and how it should be maintained as required to obtain maximum image-forming capacity and resolution. The components of the microscope are described in detail here.

  11. Microscopic colitis : an unfamiliar but treatable disease

    NARCIS (Netherlands)

    van der Wouden, E. J.; Karrenbeld, A.; Kleibeuker, J. H.; Dijkstra, G.

    Chronic diarrhoea is a frequent complaint in clinical practice. Microscopic colitis is the cause of this symptom in 10% of these cases and the prevalence is rising. To exclude microscopic colitis a colonoscopy with multiple biopsies of different regions of the colon is mandatory. A sigmoidoscopy

  12. A microscopic model of triangular arbitrage

    Science.gov (United States)

    Aiba, Yukihiro; Hatano, Naomichi

    2006-11-01

    We introduce a microscopic model which describes the dynamics of each dealer in multiple foreign exchange markets, taking account of the triangular arbitrage transaction. The model reproduces the interaction among the markets well. We explore the relation between the parameters of the present microscopic model and the spring constant of a macroscopic model that we proposed previously.

  13. Quantum theory and microscopic mechanics. I

    International Nuclear Information System (INIS)

    Yussouff, M.

    1984-08-01

    The need for theoretical descriptions and experimental observations on 'small' individual systems is emphasized. It is shown that the mathematical basis for microscopic mechanics is very simple in one dimension. The square well problem is discussed to clarify general points about stationary states and the continuity of (p'/p) across potential boundaries in the applications of microscopic mechanics. (author)

  14. Method for calibration of an axial tomographic scanner

    International Nuclear Information System (INIS)

    Sparks, R.A.

    1977-01-01

    The method of calibrating an axial tomographic scanner including frame means having an opening therein in which an object to be examined is to be placed, source and detector means mounted on the frame means for directing one or more beams of penetrating radiation through the object from the source to the detector means, and means to rotate the scanner including the source and detector means about the object whereby a plurality of sets of data corresponding to the transmission or absorption by the object of a plurality of beams of penetrating radiation are collected; the calibration method comprising mounting calibration means supporting an adjustable centering member onto the frame means, positioning the adjustable centering member at approximately the center of rotation of the scanner, placing position-sensitive indicator means adjacent the approximately centered member, rotating the scanner and the calibration means mounted thereon at least one time and, if necessary, adjusting the positioning of the centering member until the centering member is coincident with the center of rotation of the scanner as determined by minimum deflection of the position-sensitive indicator means, rotating and translating the source and detector means and determining for each angular orientation of the frame means supporting the source and detector means the central position of each translational scan relative to the centered member and/or if a plurality of detectors are utilized with the detector means for each planar slice of the object being examined, the central position of each translational scan for each detector relative to the centered member

  15. Software development for modeling positrons emission tomograph scanners

    International Nuclear Information System (INIS)

    Vieira, Igor Fagner

    2013-01-01

    The Geant4 Application for Tomographic Emission (GATE) is an international platform recognized and used to develop Computational Model Exposure (CME) in the context of Nuclear Medicine, although currently there are dedicated modules for applications in Radiotherapy and Computed Tomography (CT). GATE uses Monte Carlo (MC) methods, and has a scripting language of its own. The writing of scripts for simulation of a PET scanner in GATE involves a number of interrelated steps, and the accuracy of the simulation is dependent on the correct setup of the geometries involved, since the physical processes depend on them, as well as the modeling of electronic detectors in module Digitizer, for example. The manual implementation of this setup can be a source of errors, especially for users without experience in the field of simulations or without any previous knowledge of a programming language, and also due to the the fact that the modeling process in GATE still remains bounded to LINUX / UNIX based systems, an environment only familiar to a few. This becomes an obstacle for beginners and prevents the use of GATE by a larger number of users interested in optimizing their experiments and/or clinical protocols through a more accessible, fast and friendly application. The objective of this work is therefore to develop a user-friendly software for the modeling of Positron Emission Tomography called GUIGATE (Graphical User Interface for GATE), with specific modules dedicated to quality control in PET scanners. The results exhibit the features available in this first version of GUIGATE, present in a set of windows that allow users to create their input files, perform and display in real time the model and analyze its output file in a single environment, allowing so intuitively access the entire architecture of the GATE simulation and to CERN's data analyzer, the ROOT. (author)

  16. Topographic, Tomographic, and Aberrometric Characteristics of Post-LASIK Ectasia.

    Science.gov (United States)

    Padmanabhan, Prema; Rachapalle Reddi, Sudhir; Sivakumar, Poornima Devi

    2016-11-01

    To report the refractive, topographic, tomographic, and aberrometric characteristics of post-LASIK ectasia; to compare these characteristics with normal post-LASIK controls; and to propose a comprehensive system to grade the severity of post-LASIK ectasia. The refraction, corrected distance visual acuity (CDVA), magnitude, and location of the steepest and thinnest point on the cornea, the highest anterior and posterior surface elevation, the radius of best fit sphere, corneal asphericity, and corneal aberrations were measured in 50 eyes of 29 patients with post-LASIK ectasia. These were compared with corresponding parameters in 50 eyes that did not develop ectasia for more than 1 year after LASIK. A logistic regression analysis was used to create a scoring system to grade the severity. Eyes with post-LASIK ectasia had significantly higher myopia with astigmatism and a lower CDVA than control eyes. Mean topographic toricity was 3.4 ± 1.9D, mean keratometry at the steepest point was 55.32 ± 6.63D, mean highest posterior elevation was 69.72 ± 3 μm, and mean coma was -2.06 ± 1.2 μm. All these parameters were significantly higher than corresponding values in the control group (p ectasia compared to controls. Five parameters, namely, CDVA, spherical equivalent, highest posterior corneal elevation, spherical aberration, and corneal asphericity, were identified as significant predictors of post-LASIK ectasia and used to create a scoring system. Post-LASIK ectasia is characterized by significant changes in refraction, topography, tomography, and aberrometry. The proposed scoring system may be useful in diagnosing, grading, and monitoring post-LASIK ectasia.

  17. Imaging properties of a positron tomograph with 280 BGO crystals

    International Nuclear Information System (INIS)

    Derenzo, S.E.; Budinger, T.F.; Huesman, R.H.; Cahoon, J.L.; Vuletich, T.

    1980-11-01

    The basic imaging properties of the Donner 280-BGO-Crystal positron tomograph were measured and compared with the same system when it was equipped with 280 NaI(T1) crystals. The NaI(T1) crystals were 8 mm x 30 mm x 50 mm deep, sealed in 10 mm wide stainless steel cans. The BGO crystals are 9.5 mm x 32 mm x 32 mm deep and as they are not hygroscopic do not require sealed cans. With a shielding gap of 3 cm (section thickness 1.7 cm FWHM) the sensitivity of the BGO system is 55,000 events per sec for 1 μCi per cm 3 in a 20 cm cylinder of water, which is 2.3 times higher than the NaI(T1) system. For a 200 μCi/cm line source on the ring axis in a 20 cm diameter water cylinder, the BGO system records 86% of the scatter fraction and 66% of the accidental fraction of the NaI(T1) system. The lower light yield and poorer time resolution of BGO requires a wider coincidence timing window than NaI(T1). However, the ability to use full-energy pulse height selection with a 2.3-fold improvement in sensitivity results in an overall reduction in the fraction of accidental events recorded. The in-plane resolution of the BGO system is 9 to 10 mm FWHM within the central 30 cm diameter field, and the radial elongation at the edge of the field in the NaI(T1) system has been nearly eliminated

  18. Tomographic models and seismotectonics of the Reggio Emilia region, Italy

    Science.gov (United States)

    Ciaccio, M. G.; Chiarabba, C.

    2002-02-01

    The aim of this study is to define the Vp and Vp/Vs structure of the fault zone ruptured by the M L 5.1 earthquake of October 15, 1996 which occurred near Reggio Emilia (central-northern Italy). A 1-month-long seismic sequence followed the mainshock and occurred in a small region along the outer border of the northern Apenninic belt, at depth ranging between 10 and 17 km. P- and S-wave arrival times from 304 aftershocks recorded by two local dense seismic arrays installed in the epicentral region have been inverted to obtain one- and three-dimensional velocity models by using state of the art local earthquake tomographic techniques. Velocity models and aftershock relocation help us to infer the seismotectonic of the region. Earthquakes originated along a NW-dipping backthrust of a NE-trending main thrust, composing the western part of the broad Ferrara Arc. A main high Vp and high Vp/Vs region delineates a pop-up structure in the center of the area. The high Vp/Vs within the pop-up structure supports the presence of a zone with increased pore pressure. The hypocentral depth of both mainshock and aftershocks is greater than those usually found for the main seismogenic regions of the Apenninic belt. P-wave velocity values in the seismogenic area, obtained by tomography, are compatible with rocks of the Mesozoic cover and suggest that seismicity occurred within the Mesozoic units stack at present by compressional tectonics.

  19. Tomographic Site Characterization Using CPT, ERT, and GPR

    Energy Technology Data Exchange (ETDEWEB)

    Rexford M. Morey

    1997-05-23

    The U.S. Department of Energy (DOE) is responsible for the cleanup of inactive DOE sites and for bringing DOE sites and facilities into compliance with federal, state and local laws and regulations. The DOE's Office of Environmental Management (EM) needs advanced technologies that can make environmental restoration and waste management operations more efficient and less costly. These techniques are required to better characterize the physical, hydrogeological, and chemical properties of the subsurface while minimizing and optimizing the use of boreholes and monitoring wells. Today the cone penetrometer technique (CPT) is demonstrating the value of a minimally invasive deployment system fix site characterization. Applied Research Associates is developing two new sensor packages for site characterization and monitoring. The two new methods are: . Electrical Resistivity Tomography (ERT) and . Ground Penetrating Radar (GPR) Tomography. These sensor systems are now integrated with the Cone Penetrometer Technique (CPT). The results of this program now make it possible to install ERT and GPR units by CPT methods and thereby reduce installation costs and total costs for ERT and GPR surveys. These two techniques can complement each other in regions of low resistivity where ERT is more effective and regions of high resistivity where GPR is more effective. The results show that CPT-installed GeoWells can be used in both ERT and GPR borehole tomographic subsurface imaging. These two imaging techniques can be used for environmental site characterization and environmental remediation monitoring. Technologies used for site characterization and monitoring have numerous and diverse applications within site clean-up and waste management operations.

  20. Tomographic Inversion for Shear Velocity Beneath the North American Plate

    Science.gov (United States)

    Grand, Stephen P.

    1987-12-01

    A tomographic back projection scheme has been applied to S and SS travel times to invert for shear velocity below the North American plate. The data range in distance from 8° to 80°, and a total of 3923 arrival times were used. First arrivals were measured directly off the seismograms, while the arrival times of later arrivals were found by a waveform correlation technique using synthetic seismograms. The starting model was laterally heterogeneous in the upper 400 km to account for the first-order differences in ray paths already known. The model was divided into blocks with horizontal dimensions of 500 km by 500 km and varying vertical thicknesses. Good resolution was obtained for structure from just below the crust to about 1700 km depth in the mantle. In the upper mantle a high-velocity root was found directly beneath the Canadian shield to about 400 km depth with the Superior province having the highest velocity and deepest root. The east coast of the United States was found to have intermediate velocities from 100 to 350 km depth and the western United States the slowest velocities at these depths. Below 400 km depth the most significant structure found is a slab-shaped high-velocity anomaly from the eastern Carribean to the northern United States. Beneath the Carribean this anomaly is almost vertical and extends from about 700 km to 1700 km depth. Further to the north, the anomaly dips to the east with high velocities at 700 km depth in the central United States and high velocities below 1100 km depth beneath the east coast. The anomaly is about 1% in magnitude. This lower-mantle anomaly may be associated with past subduction of the Farallon plate beneath North America.

  1. Tomographic flow cytometry assisted by intelligent wavefronts analysis

    Science.gov (United States)

    Merola, F.; Memmolo, P.; Miccio, L.; Mugnano, M.; Ferraro, P.

    2017-06-01

    High-throughput single-cell analysis is a challenging target for implementing advanced biomedical applications. An excellent candidate for this aim is label-free tomographic phase microscopy. However, in-line tomography is very difficult to be implemented in practice, as it requires complex setup for rotating the sample and/or illuminate the cell along numerous directions [1]. We exploit random rolling of cells while they are flowing along a microfluidic channel demonstrating that it is possible to obtain in-line phase-contrast tomography by adopting strategies for intelligent wavefronts analysis thus obtaining complete retrieval of both 3D-position and orientation of rotating cells [2]. Thus, by numerical wavefront analysis a-priori knowledge of such information is no longer needed. This approach makes continuos-flow cyto-tomography suitable for practical operation in real-world, single-cell analysis and with substantial simplification of the optical system avoiding any mechanical/optical scanning of light source. Demonstration is given for different classes of biosamples, red-blood-cells (RBCs), diatom algae and fibroblast cells [3]. Accurate characterization of each type of cells is reported despite their very different nature and materials content, thus showing the proposed method can be extended, by adopting two alternate strategies of wavefront-analysis, to many classes of cells. In particular, for RBCs we furnish important parameters as 3D morphology, Corpuscular Hemoglobin (CH), Volume (V), and refractive index (RI) for each single cell in the total population [3]. This could open a new route in blood disease diagnosis, for example for the isolation and characterization of "foreign" cells in the blood stream, the so called Circulating Tumor Cells (CTC), early manifestation of metastasis.

  2. Polymerized LB Films Imaged with a Combined Atomic Force Microscope-Fluorescence Microscope

    NARCIS (Netherlands)

    Putman, C.A.J.; Putman, Constant A.J.; Hansma, Helen G.; Gaub, Hermann E.; Hansma, Paul K.

    1992-01-01

    The first results obtained with a new stand-alone atomic force microscope (AFM) integrated with a standard Zeiss optical fluorescence microscope are presented. The optical microscope allows location and selection of objects to be imaged with the high-resolution AFM. Furthermore, the combined

  3. Evaluation of a computer aided neutron tomographic system incorporating a gaseous position sensitive detector

    Science.gov (United States)

    Silvani, M. I.; Lopes, R. T.; de Jesus, E. F. O.; de Almeida, G. L.; Barbosa, A. F.

    2003-06-01

    A position sensitive gaseous detector, formerly designed to operate with X-rays, has been modified to equip a third generation tomographic system working with a parallel thermal neutron beam. For this purpose, the original filling-gas has been replaced by 3He-enriched helium, which plays simultaneously the role of filling-gas for the ionization process and converter of neutrons into charged particles. This paper describes the modifications done to the detector, the measurements carried out to evaluate its own performance and that of the tomographic system attached to it. Some tomographic images acquired using that system are presented as well. Tomographic systems equipped with this kind of detector should require substantially much less time than those conventional ones, where a sample translation is required. The Argonauta reactor operating at the Instituto de Engenharia Nuclear (IEN/CNEN-Brazil) has been utilized as the source of neutrons, furnishing a flux of 4.5×10 5 n cm -2 s -1 at its main irradiation channel where the tomographic system has been placed.

  4. Reconstruction of tomographic image from x-ray projections of a few views

    International Nuclear Information System (INIS)

    Kobayashi, Fujio; Yamaguchi, Shoichiro

    1982-01-01

    Computer tomographs have progressed rapidly, and in the latest high performance types, the photographing time has been shortened to less than 5 sec, but the clear images of hearts have not yet been obtained. The X-ray tomographs used so far irradiate X-ray from many directions and measure the projected data, but by limiting projection direction to a small number, it was planned to shorter the X-ray photographing time and to reduce X-ray exposure as the objective of this study. In this paper, a method is proposed, by which tomographic images are reconstructed from projected data in a small number of direction by generalized inverse matrix penalty method. This method is the calculation method newly devised by the authors for this purpose. It is a kind of the nonlinear planning method added with the restrictive condition using a generalized inverse matrix, and it is characterized by the simple calculation procedure and rapid convergence. Moreover, the effect on reconstructed images when errors are included in projected data was examined. Also, the simple computer simulation to reconstruct tomographic images using the projected data in four directions was performed, and the usefulness of this method was confirmed. It contributes to the development of superhigh speed tomographs in future. (Kako, I.)

  5. 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.

  6. Development and applications of the positron microscope

    International Nuclear Information System (INIS)

    1991-01-01

    Progress on the positron microscope during the past year has been steady, and we currently project that initial microscope images can be collected during mid to late summer of 1992. Work during the year has mainly been divided among four areas of effort: hardware construction; power supply and control system development; radioactive source fabrication; and planning of initial experimental projects. Details of progress in these areas will be given below. An initial optical design of the microscope was completed during 1990, but during the past year, significant improvements have been made to this design, and several limiting cases of microscope performance have been evaluated. The results of these evaluations have been extremely encouraging, giving us strong indications that the optical performance of the microscope will be better than originally anticipated. In particular, we should be able to explore ultimate performance capabilities of positron microscopy using our currently planned optical system, with improvements only in the image detector system, and the positron-source/moderator configuration. We should be able to study imaging reemission microscopy with resolutions approaching 10 Angstrom and be able to produce beam spots for rastered microscope work with diameters below the 1000 Angstrom diffusion limit. Because of these exciting new possibilities, we have decided to upgrade several microscope subsystems to levels consistent with ultimate performance earlier in our construction schedule than we had previously intended. In particular, alignment facilities in the optical system, vibration isolation, and power supply and control system flexibility have all been upgraded in their design over the past year

  7. Tomographic and planar radionuclide imaging in patients suspected meniscal injury: Arthroscopic correlation

    Energy Technology Data Exchange (ETDEWEB)

    Fajman, W.A.; Diehl, M.; Dunaway, E.; Stephenson, R.; Eisner, R.; Riggins, R.S.; Berger, H.J.

    1985-05-01

    In patients (pts) with knee pain which may be related to meniscal tears, clinical judgment is used to determine whether medical management or arthroscopy is indicated. Based on the assumption that meniscal injury will result in adjacent changes in Tc-99m MDP bone images, studies using both planar and tomographic techniques were performed in 12 pts referred for arthroscopy. Planar imaging was performed in the anterior, posterior, and posterior medial and lateral oblique positions of the symptomatic knee. Single photon emission computed tomography was performed using a 64 view 360/sup 0/ acquisition of both knees. In this series, both imaging techniques were accurate in identifying abnormality, but analysis of transaxial tomographic data showed greater contrast and facilitated localization because of the better spatial orientation provided by this method. Thus, tomographic bone imaging appears valuable in defining areas of localized abnormality in the knees of pts with meniscal injury.

  8. Lamb-Wave-Based Tomographic Imaging Techniques for Hole-Edge Corrosion Monitoring in Plate Structures

    Directory of Open Access Journals (Sweden)

    Dengjiang Wang

    2016-11-01

    Full Text Available This study presents a novel monitoring method for hole-edge corrosion damage in plate structures based on Lamb wave tomographic imaging techniques. An experimental procedure with a cross-hole layout using 16 piezoelectric transducers (PZTs was designed. The A0 mode of the Lamb wave was selected, which is sensitive to thickness-loss damage. The iterative algebraic reconstruction technique (ART method was used to locate and quantify the corrosion damage at the edge of the hole. Hydrofluoric acid with a concentration of 20% was used to corrode the specimen artificially. To estimate the effectiveness of the proposed method, the real corrosion damage was compared with the predicted corrosion damage based on the tomographic method. The results show that the Lamb-wave-based tomographic method can be used to monitor the hole-edge corrosion damage accurately.

  9. MCPT: A Monte Carlo code for simulation of photon transport in tomographic scanners

    International Nuclear Information System (INIS)

    Prettyman, T.H.; Gardner, R.P.; Verghese, K.

    1990-01-01

    MCPT is a special-purpose Monte Carlo code designed to simulate photon transport in tomographic scanners. Variance reduction schemes and sampling games present in MCPT were selected to characterize features common to most tomographic scanners. Combined splitting and biasing (CSB) games are used to systematically sample important detection pathways. An efficient splitting game is used to tally particle energy deposition in detection zones. The pulse height distribution of each detector can be found by convolving the calculated energy deposition distribution with the detector's resolution function. A general geometric modelling package, HERMETOR, is used to describe the geometry of the tomographic scanners and provide MCPT information needed for particle tracking. MCPT's modelling capabilites are described and preliminary experimental validation is presented. (orig.)

  10. Imaging earth's interior: Tomographic inversions for mantle P-wave velocity structure

    Energy Technology Data Exchange (ETDEWEB)

    Pulliam, R.J.

    1991-07-01

    A formalism is developed for the tomographic inversion of seismic travel time residuals. The travel time equations are solved both simultaneously, for velocity model terms and corrections to the source locations, and progressively, for each set of terms in succession. The methods differ primarily in their treatment of source mislocation terms. Additionally, the system of equations is solved directly, neglecting source terms. The efficacy of the algorithms is explored with synthetic data as we perform simulations of the general procedure used to produce tomographic images of Earth's mantle from global earthquake data. The patterns of seismic heterogeneity in the mantle that would be returned reliably by a tomographic inversion are investigated. We construct synthetic data sets based on real ray sampling of the mantle by introducing spherical harmonic patterns of velocity heterogeneity and perform inversions of the synthetic data.

  11. Imaging earth`s interior: Tomographic inversions for mantle P-wave velocity structure

    Energy Technology Data Exchange (ETDEWEB)

    Pulliam, Robert Jay [Univ. of California, Berkeley, CA (United States)

    1991-07-01

    A formalism is developed for the tomographic inversion of seismic travel time residuals. The travel time equations are solved both simultaneously, for velocity model terms and corrections to the source locations, and progressively, for each set of terms in succession. The methods differ primarily in their treatment of source mislocation terms. Additionally, the system of equations is solved directly, neglecting source terms. The efficacy of the algorithms is explored with synthetic data as we perform simulations of the general procedure used to produce tomographic images of Earth`s mantle from global earthquake data. The patterns of seismic heterogeneity in the mantle that would be returned reliably by a tomographic inversion are investigated. We construct synthetic data sets based on real ray sampling of the mantle by introducing spherical harmonic patterns of velocity heterogeneity and perform inversions of the synthetic data.

  12. Registration of synthetic tomographic projection data sets using cross-correlation

    International Nuclear Information System (INIS)

    Fitchard, E.E.; Aldridge, J.S.; Reckwerdt, P.J.; Mackie, T.R.

    1998-01-01

    Tomographic registration, a method that makes possible accurate patient registration directly from projection data, consists of three processing steps: (i) manual coarse positioning, (ii) tomographic projection set acquisition, and (iii) computer mediated refined positioning. In the coarse positioning stage, the degree of patient alignment is comparable with that achieved with the standard radiotherapy set-up. However, the accuracy requirements are somewhat more relaxed in that meticulous alignment of the patient using external laser indicators is not necessary. Instead, tomographic projection sets are compared with planning CTs in order to achieve improved patient set-up. The projection sets are cross-correlated to obtain the best-fit translation and rotation offsets. The algorithm has been tested on synthetic data with the incorporation of varying amounts of Gaussian pseudo-random noise. These tests demonstrate the algorithm's stability and also confirm that alignment can be achieved with an accuracy of less than one projection pixel. (author)

  13. Directional fine structure in absorption of white x rays: A tomographic interpretation

    International Nuclear Information System (INIS)

    Korecki, P.; Szymonski, M.; Tolkiehn, M.; Novikov, D. V.; Materlik, G.

    2006-01-01

    We discuss directional fine structure in absorption of white x rays for tomographic imaging of crystal structure at the atomic level. The interference between a direct x-ray beam and the secondary waves coherently scattered inside a specimen modifies the total wave field at the position of the absorbing atoms. For a white x-ray beam, the wave field variations cancel out by energy integration for all directions, except for the near forward scattering components, coinciding with the incident beam. Therefore, two-dimensional patterns of the angular-dependent fine structure in absorption of white x rays can be interpreted as real-space projections of atomic structure. In this work, we present a theory describing the directional fine structure in white x-ray absorption and a tomographic approach for crystal structure retrieval developed on its basis. The tomographic algorithm is applied to the experimental x-ray absorption data recorded for GaP crystals

  14. Atomic Force Microscope Mediated Chromatography

    Science.gov (United States)

    Anderson, Mark S.

    2013-01-01

    The atomic force microscope (AFM) is used to inject a sample, provide shear-driven liquid flow over a functionalized substrate, and detect separated components. This is demonstrated using lipophilic dyes and normal phase chromatography. A significant reduction in both size and separation time scales is achieved with a 25-micron-length column scale, and one-second separation times. The approach has general applications to trace chemical and microfluidic analysis. The AFM is now a common tool for ultra-microscopy and nanotechnology. It has also been demonstrated to provide a number of microfluidic functions necessary for miniaturized chromatography. These include injection of sub-femtoliter samples, fluidic switching, and sheardriven pumping. The AFM probe tip can be used to selectively remove surface layers for subsequent microchemical analysis using infrared and tip-enhanced Raman spectroscopy. With its ability to image individual atoms, the AFM is a remarkably sensitive detector that can be used to detect separated components. These diverse functional components of microfluidic manipulation have been combined in this work to demonstrate AFM mediated chromatography. AFM mediated chromatography uses channel-less, shear-driven pumping. This is demonstrated with a thin, aluminum oxide substrate and a non-polar solvent system to separate a mixture of lipophilic dyes. In conventional chromatographic terms, this is analogous to thin-layer chromatography using normal phase alumina substrate with sheardriven pumping provided by the AFM tip-cantilever mechanism. The AFM detection of separated components is accomplished by exploiting the variation in the localized friction of the separated components. The AFM tip-cantilever provides the mechanism for producing shear-induced flows and rapid pumping. Shear-driven chromatography (SDC) is a relatively new concept that overcomes the speed and miniaturization limitations of conventional liquid chromatography. SDC is based on a

  15. Operating microscopes: past, present, and future.

    Science.gov (United States)

    Uluç, Kutluay; Kujoth, Gregory C; Başkaya, Mustafa K

    2009-09-01

    The operating microscope is a fixture of modern surgical facilities, and it is a critically important factor in the success of many of the most complex and difficult surgical interventions used in medicine today. The rise of this key surgical tool reflects advances in understanding the principles of optics and vision that have occurred over centuries. The development of reading spectacles in the late 13th century led to the construction of early compound microscopes in the 16th and 17th centuries by Lippershey, Janssen, Galileo, Hooke, and others. Perhaps surprisingly, Leeuwenhoek's simple microscopes of this era offered improved performance over his contemporaries' designs. The intervening years saw improvements that reduced the spherical and chromatic aberrations present in compound microscopes. By the late 19th century, Carl Zeiss and Ernst Abbe ushered the compound microscope into the beginnings of the modern era of commercial design and production. The introduction of the microscope into the operating room by Nylén in 1921 initiated a revolution in surgical practice that gained momentum throughout the 1950s with multiple refinements, the introduction of the Zeiss OPMI series, and Kurze's application of the microscope to neurosurgery in 1957. Many of the refinements of the last 50 years have greatly improved the handling and practical operation of the surgical microscope, considerations which are equally important to its optical performance. Today's sophisticated operating microscopes allow for advanced real-time angiographic and tumor imaging. In this paper the authors discuss what might be found in the operating rooms of tomorrow.

  16. A comparison of newborn stylized and tomographic models for dose assessment in paediatric radiology

    International Nuclear Information System (INIS)

    Staton, R J; Pazik, F D; Nipper, J C; Williams, J L; Bolch, W E

    2003-01-01

    Establishment of organ doses from diagnostic and interventional examinations is a key component to quantifying the radiation risks from medical exposures and for formulating corresponding dose-reduction strategies. Radiation transport models of human anatomy provide a convenient method for simulating radiological examinations. At present, two classes of models exist: stylized mathematical models and tomographic voxel models. In the present study, organ dose comparisons are made for projection radiographs of both a stylized and a tomographic model of the newborn patient. Sixteen separate radiographs were simulated for each model at x-ray technique factors typical of newborn examinations: chest, abdomen, thorax and head views in the AP, PA, left LAT and right LAT projection orientation. For AP and PA radiographs of the torso (chest, abdomen and thorax views), the effective dose assessed for the tomographic model exceeds that for the stylized model with per cent differences ranging from 19% (AP abdominal view) to 43% AP chest view. In contrast, the effective dose for the stylized model exceeds that for the tomographic model for all eight lateral views including those of the head, with per cent differences ranging from 9% (LLAT chest view) to 51% (RLAT thorax view). While organ positioning differences do exist between the models, a major factor contributing to differences in effective dose is the models' exterior trunk shape. In the tomographic model, a more elliptical shape is seen thus providing for less tissue shielding for internal organs in the AP and PA directions, with corresponding increased tissue shielding in the lateral directions. This observation is opposite of that seen in comparisons of stylized and tomographic models of the adult

  17. The Mathematical Microscope - Making the inaccessible accessible

    DEFF Research Database (Denmark)

    Ottesen, Johnny T.

    2011-01-01

      In this chapter we introduce a new term, the "Mathematical Microscope", as a method of using mathematics in accessing information about reality when this information is otherwise inaccessible. Furthermore, we discuss how models and experiments are related: none of which are important without...... the other. In the sciences and medicine, a link that is often missing in the chain of a system can be made visible with the aid of the mathematical microscope. The mathematical microscope serves not only as a lens to clarify a blurred picture but more important as a tool to unveil profound truths...

  18. Microscopes for NASA's Phoenix Mars Lander

    Science.gov (United States)

    2007-01-01

    One part of the Microscopy, Electrochemistry, and Conductivity Analyzer instrument for NASA's Phoenix Mars Lander is a pair of telescopes with a special wheel (on the right in this photograph) for presenting samples to be inspected with the microscopes. A horizontally mounted optical microscope (on the left in this photograph) and an atomic force microscope will examine soil particles and possibly ice particles. The shapes and the size distributions of soil particles may tell scientists about environmental conditions the material has experienced. Tumbling rounds the edges. Repeated wetting and freezing causes cracking. Clay minerals formed during long exposure to water have distinctive, platy particles shapes.

  19. Confocal scanning microscope for nuclear photoemulsion

    International Nuclear Information System (INIS)

    Batusov, Yu.A.; Kovalev, Yu.S.; Soroko, L.M.

    2005-01-01

    The application of the confocal scanning microscope to the objects in the nuclear photoemulsion is described. An array of 27 microtomograms of single silver grain is shown. The cross sections of the same particle track of diameter 1 μm, detected by means of the confocal scanning microscope with open and annular apertures, are presented. It was shown that the confocal scanning microscope opens indeed new opportunities for the nuclear photoemulsion technique to get previously inaccessible information for physics of the short-living particles

  20. A tomographic study of the condyle position in temporomandibular disorders

    International Nuclear Information System (INIS)

    Choi, Sung Youn; Ryu, Young Kyu

    1988-01-01

    The aim of this study was to determine whether T.M.J. tomographic examination yielded significant difference in condyle positions among asymptomatic, myalgia, derangement, and arthrosis group of T.M.J. disorders. The author obtained sagittal linear tomograms of right and left T.M.Js. of 36 asymptomatic, 22 myalgia, 54 derangement, and 31 arthrosis patients taken at serial lateral, central, and medial sections in the intercuspal position after submentovertex radiographs analyzed. With the dual linear measurements of the posterior and anterior interarticular space, condyle positions were mathematically expressed as proportion. All data from these analysis was recorded and processed statistically. The results were obtained as follows: 1. In asymptomatic group, radiographically concentric condyle position was found in 50.0% to 65.4% of subjects, with a substance range of variability. No significant differences existed between men and women and also between right and left T.M.Js. for condyle position. 2. In women, significant difference for mean condyle position of left lateral section of each diagnostic category existed between derangement and myalgia groups (P< .05). Also that of left central section existed between derangement and myalgia group, and that of left medial section existed between derangement and myalgia groups (P< . 05). 3. In main-symptom side, condyle position in myalgia group was more concentric, and condyle position in derangement and group was more posterior. This showed significant differences between derangement and myalgia groups in lateral, central, and medial sections of main symptom side, and only between derangement and myalgia groups in central section of contra-lateral sides (P< .05). Condyle position in arthrosis group was broadly distributed among all positions. 4. In contra-lateral side, significant difference for mean condyle position of central section of each symptomatic group existed between derangement and myalgia group (P< .05

  1. A tomographic study of the condyle position in temporomandibular disorders

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Sung Youn; Ryu, Young Kyu [Dept. of Oral Radiology, College of Dentistry, Yonsei University, Seoul (Korea, Republic of)

    1988-11-15

    The aim of this study was to determine whether T.M.J. tomographic examination yielded significant difference in condyle positions among asymptomatic, myalgia, derangement, and arthrosis group of T.M.J. disorders. The author obtained sagittal linear tomograms of right and left T.M.Js. of 36 asymptomatic, 22 myalgia, 54 derangement, and 31 arthrosis patients taken at serial lateral, central, and medial sections in the intercuspal position after submentovertex radiographs analyzed. With the dual linear measurements of the posterior and anterior interarticular space, condyle positions were mathematically expressed as proportion. All data from these analysis was recorded and processed statistically. The results were obtained as follows: 1. In asymptomatic group, radiographically concentric condyle position was found in 50.0% to 65.4% of subjects, with a substance range of variability. No significant differences existed between men and women and also between right and left T.M.Js. for condyle position. 2. In women, significant difference for mean condyle position of left lateral section of each diagnostic category existed between derangement and myalgia groups (P< .05). Also that of left central section existed between derangement and myalgia group, and that of left medial section existed between derangement and myalgia groups (P< . 05). 3. In main-symptom side, condyle position in myalgia group was more concentric, and condyle position in derangement and group was more posterior. This showed significant differences between derangement and myalgia groups in lateral, central, and medial sections of main symptom side, and only between derangement and myalgia groups in central section of contra-lateral sides (P< .05). Condyle position in arthrosis group was broadly distributed among all positions. 4. In contra-lateral side, significant difference for mean condyle position of central section of each symptomatic group existed between derangement and myalgia group (P< .05

  2. Minimum Detectable Activity for Tomographic Gamma Scanning System

    Energy Technology Data Exchange (ETDEWEB)

    Venkataraman, Ram [Canberra Industries (AREVA BDNM), Meriden, CT (United States); Smith, Susan [Canberra Industries (AREVA BDNM), Meriden, CT (United States); Kirkpatrick, J. M. [Canberra Industries (AREVA BDNM), Meriden, CT (United States); Croft, Stephen [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-01-01

    For any radiation measurement system, it is useful to explore and establish the detection limits and a minimum detectable activity (MDA) for the radionuclides of interest, even if the system is to be used at far higher values. The MDA serves as an important figure of merit, and often a system is optimized and configured so that it can meet the MDA requirements of a measurement campaign. The non-destructive assay (NDA) systems based on gamma ray analysis are no exception and well established conventions, such the Currie method, exist for estimating the detection limits and the MDA. However, the Tomographic Gamma Scanning (TGS) technique poses some challenges for the estimation of detection limits and MDAs. The TGS combines high resolution gamma ray spectrometry (HRGS) with low spatial resolution image reconstruction techniques. In non-imaging gamma ray based NDA techniques measured counts in a full energy peak can be used to estimate the activity of a radionuclide, independently of other counting trials. However, in the case of the TGS each “view” is a full spectral grab (each a counting trial), and each scan consists of 150 spectral grabs in the transmission and emission scans per vertical layer of the item. The set of views in a complete scan are then used to solve for the radionuclide activities on a voxel by voxel basis, over 16 layers of a 10x10 voxel grid. Thus, the raw count data are not independent trials any more, but rather constitute input to a matrix solution for the emission image values at the various locations inside the item volume used in the reconstruction. So, the validity of the methods used to estimate MDA for an imaging technique such as TGS warrant a close scrutiny, because the pair-counting concept of Currie is not directly applicable. One can also raise questions as to whether the TGS, along with other image reconstruction techniques which heavily intertwine data, is a suitable method if one expects to measure samples whose activities

  3. Software for tomographic analysis: application in ceramic filters

    International Nuclear Information System (INIS)

    Figuerola, W.B.; Assis, J.T.; Oliveira, L.F.; Lopes, R.T.

    2001-01-01

    and UNIX). Various digital image processing techniques were implemented to extract physical properties such as: distance, volume, area and perimeter; digital filters as: Median filter, Histogram equalization, threshold quantization, boundary detection (Laplace and Sobel); and for the volume rendering, the Ray Casting technique was used. The results obtained with this software permits its use in this area of ceramic filters applications and to analyses others types of tomographic images

  4. Temporal bone anomalies in the branchio-oto-renal syndrome: detailed computed tomographic and magnetic resonance imaging findings.

    NARCIS (Netherlands)

    Ceruti, S.; Stinckens, C.I.C.; Cremers, C.W.R.J.; Casselman, J.W.

    2002-01-01

    OBJECTIVE: To inventory computed tomographic and magnetic resonance imaging findings in the branchio-oto-renal (BOR) syndrome. STUDY DESIGN: A prospective computed tomographic and magnetic resonance imaging study on a family with the BOR syndrome. SETTING: Department of medical imaging and magnetic

  5. 3D UWB Magnitude-Combined Tomographic Imaging for Biomedical Applications. Algorithm Validation

    Directory of Open Access Journals (Sweden)

    S. Capdevila

    2011-06-01

    Full Text Available Biomedical microwave imaging is a topic of continuous research for its potential in different areas especially in breast cancer detection. In this paper, 3D UWB Magnitude-Combined tomographic algorithm is assessed for this recurrent application, but also for a more challenging one such as brain stroke detection. With the UWB Magnitude-Combined concept, the algorithm can take advantage of both the efficiency of Fourier Diffraction Theorem-based tomographic formulation and the robustness and image quality improvement provided by a multi-frequency combination.

  6. phytochemical and microscopical evaluation of desmodium velutinum

    African Journals Online (AJOL)

    USER

    2015-06-01

    , transverse and longitudinal sections of the leaves of .... quantity for preliminary screening and biological studies. Microscopical Examination .... subnitrate dissolved in 20ml acetic acid, made up to 100ml with distilled water).

  7. Feedback regulation of microscopes by image processing.

    Science.gov (United States)

    Tsukada, Yuki; Hashimoto, Koichi

    2013-05-01

    Computational microscope systems are becoming a major part of imaging biological phenomena, and the development of such systems requires the design of automated regulation of microscopes. An important aspect of automated regulation is feedback regulation, which is the focus of this review. As modern microscope systems become more complex, often with many independent components that must work together, computer control is inevitable since the exact orchestration of parameters and timings for these multiple components is critical to acquire proper images. A number of techniques have been developed for biological imaging to accomplish this. Here, we summarize the basics of computational microscopy for the purpose of building automatically regulated microscopes focus on feedback regulation by image processing. These techniques allow high throughput data acquisition while monitoring both short- and long-term dynamic phenomena, which cannot be achieved without an automated system. © 2013 The Authors Development, Growth & Differentiation © 2013 Japanese Society of Developmental Biologists.

  8. Assessing and benchmarking multiphoton microscopes for biologists.

    Science.gov (United States)

    Corbin, Kaitlin; Pinkard, Henry; Peck, Sebastian; Beemiller, Peter; Krummel, Matthew F

    2014-01-01

    Multiphoton microscopy has become staple tool for tracking cells within tissues and organs due to superior depth of penetration, low excitation volumes, and reduced phototoxicity. Many factors, ranging from laser pulse width to relay optics to detectors and electronics, contribute to the overall ability of these microscopes to excite and detect fluorescence deep within tissues. However, we have found that there are few standard ways already described in the literature to distinguish between microscopes or to benchmark existing microscopes to measure the overall quality and efficiency of these instruments. Here, we discuss some simple parameters and methods that can either be used within a multiphoton facility or by a prospective purchaser to benchmark performance. This can both assist in identifying decay in microscope performance and in choosing features of a scope that are suited to experimental needs. © 2014 Elsevier Inc. All rights reserved.

  9. Nucleon relativistic phenomenological and microscopic optical potential

    International Nuclear Information System (INIS)

    Shen Qingbiao; Feng Dachun; Zhuo Yizhong

    1991-01-01

    In this talk, both the phenomenological and microscopic nucleon relativistic optical potentials are presented. The global neutron relativistic phenomenological optical potential (RPOP) based on the available experimental data for various nuclei ranging from C to U with incident energies En=20-1000 MeV has been obtained through automatic search of the best parameters by computer. Then the nucleon relativistic microscopic optical potential (RMOP) is studied by utilizing effective lagrangian based on popular Walecka model. Through comparison between the theoretical results and experimental data we have shed some insight into both the RMOP and RPOP. We have concluded that both the phenomenological and microscopic relativistic optical potentials proposed here can be extensively used for intermediate energy nucleon data evaluation. Further improvement concerning how to combine the phenomenological potential with the microscopic one in order to reduce the number of free parameters appearing in RPOP is suggested. (author). 33 refs, 24 figs

  10. Understanding and caring for an operating microscope

    Directory of Open Access Journals (Sweden)

    Ismael Cordero

    2014-04-01

    Full Text Available An operating or surgical microscope is an optical instrument that provides the surgeon with a stereoscopic, high quality magnified and illuminated image of the small structures in the surgical area.

  11. Assessing and benchmarking multiphoton microscopes for biologists

    Science.gov (United States)

    Corbin, Kaitlin; Pinkard, Henry; Peck, Sebastian; Beemiller, Peter; Krummel, Matthew F.

    2017-01-01

    Multiphoton microscopy has become staple tool for tracking cells within tissues and organs due to superior depth of penetration, low excitation volumes, and reduced phototoxicity. Many factors, ranging from laser pulse width to relay optics to detectors and electronics, contribute to the overall ability of these microscopes to excite and detect fluorescence deep within tissues. However, we have found that there are few standard ways already described in the literature to distinguish between microscopes or to benchmark existing microscopes to measure the overall quality and efficiency of these instruments. Here, we discuss some simple parameters and methods that can either be used within a multiphoton facility or by a prospective purchaser to benchmark performance. This can both assist in identifying decay in microscope performance and in choosing features of a scope that are suited to experimental needs. PMID:24974026

  12. A pragmatic guide to multiphoton microscope design

    Science.gov (United States)

    Young, Michael D.; Field, Jeffrey J.; Sheetz, Kraig E.; Bartels, Randy A.; Squier, Jeff

    2016-01-01

    Multiphoton microscopy has emerged as a ubiquitous tool for studying microscopic structure and function across a broad range of disciplines. As such, the intent of this paper is to present a comprehensive resource for the construction and performance evaluation of a multiphoton microscope that will be understandable to the broad range of scientific fields that presently exploit, or wish to begin exploiting, this powerful technology. With this in mind, we have developed a guide to aid in the design of a multiphoton microscope. We discuss source selection, optical management of dispersion, image-relay systems with scan optics, objective-lens selection, single-element light-collection theory, photon-counting detection, image rendering, and finally, an illustrated guide for building an example microscope. PMID:27182429

  13. X ray imaging microscope for cancer research

    Science.gov (United States)

    Hoover, Richard B.; Shealy, David L.; Brinkley, B. R.; Baker, Phillip C.; Barbee, Troy W., Jr.; Walker, Arthur B. C., Jr.

    1991-01-01

    The NASA technology employed during the Stanford MSFC LLNL Rocket X Ray Spectroheliograph flight established that doubly reflecting, normal incidence multilayer optics can be designed, fabricated, and used for high resolution x ray imaging of the Sun. Technology developed as part of the MSFC X Ray Microscope program, showed that high quality, high resolution multilayer x ray imaging microscopes are feasible. Using technology developed at Stanford University and at the DOE Lawrence Livermore National Laboratory (LLNL), Troy W. Barbee, Jr. has fabricated multilayer coatings with near theoretical reflectivities and perfect bandpass matching for a new rocket borne solar observatory, the Multi-Spectral Solar Telescope Array (MSSTA). Advanced Flow Polishing has provided multilayer mirror substrates with sub-angstrom (rms) smoothnesss for the astronomical x ray telescopes and x ray microscopes. The combination of these important technological advancements has paved the way for the development of a Water Window Imaging X Ray Microscope for cancer research.

  14. A lensless, automated microscope for disease diagnostics

    CSIR Research Space (South Africa)

    Hugo, S

    2012-03-01

    Full Text Available using a conventional bright field microscope. Applications of this work are targeted towards the implementation of a full blood count, which could provide resource-limited areas with improved healthcare facilities and diagnosis times....

  15. A lensless, automated microscope for disease diagnostics

    CSIR Research Space (South Africa)

    Hugo, S

    2011-09-01

    Full Text Available microscope. Applications of this work are targeted towards the implementation of a full blood count, which could provide resource-limited areas with improved healthcare facilities and diagnosis times....

  16. Optics of high-performance electron microscopes*

    OpenAIRE

    Rose, H H

    2016-01-01

    During recent years, the theory of charged particle optics together with advances in fabrication tolerances and experimental techniques has lead to very significant advances in high-performance electron microscopes. Here, we will describe which theoretical tools, inventions and designs have driven this development. We cover the basic theory of higher-order electron optics and of image formation in electron microscopes. This leads to a description of different methods to correct aberrations by...

  17. Applications of Mapping and Tomographic Techniques in Gem Sciences

    Science.gov (United States)

    Shen, A. H.

    2014-12-01

    Gem Sciences are scientific studies of gemstones - their genesis, provenance, synthesis, enhancement, treatment and identification. As high quality forms of specific minerals, the gemstones exhibit unusual physical properties that are usually unseen in the regular counterparts. Most gemstones are colored by trace elements incorporated in the crystal lattice during various growth stages; forming coloration zones of various scales. Studying the spectral and chemical contrast across color zones helps elucidating the origins of colors. These are done by UV-visible spectrometers with microscope and LA-ICPMS in modern gemological laboratories. In the case of diamonds, their colored zones arise from various structural defects incorporated in different growth zones and are studied with FTIR spectrometers with IR microscope and laser photoluminescence spectrometers. Advancement in modern synthetic techniques such as chemical vapor deposition (CVD) has created some problem for identification. Some exploratory experiments in carbon isotope mapping were done on diamonds using SIMS. The most important issue in pearls is to identify one particular pearl being a cultured one or a natural pearl. The price difference can be enormous. Classical way of such identification is done by x-ray radiographs, which clearly show the bead and the nacre. Modern cultured pearl advancement has eliminated the need for an artificial bead, but a small piece of tissue instead. Nowadays, computer x-ray tomography (CT) scanning devices are used to depict the clear image of the interior of a pearl. In the Chinese jade market, filling fissures with epoxy and/or wax are very commonly seen. We are currently exploring Magnetic Resonance Imaging (MRI) technique to map the distribution of artificial resin within a polycrystalline aggregates.

  18. Development of gamma-ray tomographic system for industrial plant inspection

    International Nuclear Information System (INIS)

    Kim, Jong Bum

    2011-02-01

    Gamma-ray has been widely used in process diagnosis because of its deep penetration ability. Gamma column scanning, radioisotope tracer and gamma radiography are examples of gamma-ray applications in industries. Recently there have been growing studies on gamma-ray tomography for process diagnosis in addition to conventional gamma-ray technologies. In those studies, multi-phase flow measurement, process flow visualization and CFD validation have been achieved by gamma-ray tomographic system. There are many case studies on gamma-ray tomographic systems used in laboratories and pilot plants but few cases for real scale industrial system. The main objective of this work is to develop a movable gamma-ray tomographic system for real scale industrial plants. To develop the movable gamma-ray tomographic system, some preliminary reviews has been made on the status of industrial process tomographic techniques such as electrical impedance tomography, X-ray tomography and gamma-ray tomography. From review results, it is considered that a fixed detection system with a gamma-ray source is suitable for movable tomographic system. To actualize the fixed detection and rotating source system, 4 th generation scheme by instant installation with a gamma-ray source and portable clamp-on gamma-ray tomographic system are proposed. As for 4 th generation system, multiple discrete detectors are installed around large scale object and a source is designed to rotate inside detector circle. The general configuration is similar to medical 4 th generation CT. But unlike a same type of a medical system, this system has adopted a gamma ray source and portable detection system. This system is aiming for large scale plants whose size is too big to be scanned by conventional tomographic systems. Monte Carlo simulations are performed to validate this method by generating virtual experimental data. The source and detector are simulated as 137 Cs and 1/2 inch NaI detector. Image reconstructions are

  19. Retreatability of two endodontic sealers, EndoSequence BC Sealer and AH Plus: a micro-computed tomographic comparison

    Science.gov (United States)

    Oltra, Enrique; Cox, Timothy C.; LaCourse, Matthew R.; Johnson, James D.

    2017-01-01

    Objectives Recently, bioceramic sealers like EndoSequence BC Sealer (BC Sealer) have been introduced and are being used in endodontic practice. However, this sealer has limited research related to its retreatability. Hence, the aim of this study was to evaluate the retreatability of two sealers, BC Sealer as compared with AH Plus using micro-computed tomographic (micro-CT) analysis. Materials and Methods Fifty-six extracted human maxillary incisors were instrumented and randomly divided into 4 groups of 14 teeth: 1A, gutta-percha, AH Plus retreated with chloroform; 1B, gutta-percha, AH Plus retreated without chloroform; 2A, gutta-percha, EndoSequence BC Sealer retreated with chloroform; 2B, gutta-percha, EndoSequence BC Sealer retreated without chloroform. Micro-CT scans were taken before and after obturation and retreatment and analyzed for the volume of residual material. The specimens were longitudinally sectioned and digitized images were taken with the dental operating microscope. Data was analyzed using an ANOVA and a post-hoc Tukey test. Fisher exact tests were performed to analyze the ability to regain patency. Results There was significantly less residual root canal filling material in the AH Plus groups retreated with chloroform as compared to the others. The BC Sealer samples retreated with chloroform had better results than those retreated without chloroform. Furthermore, patency could be re-established in only 14% of teeth in the BC Sealer without chloroform group. Conclusion The results of this study demonstrate that the BC Sealer group had significantly more residual filling material than the AH Plus group regardless of whether or not both sealers were retreated with chloroform. PMID:28194360

  20. Retreatability of two endodontic sealers, EndoSequence BC Sealer and AH Plus: a micro-computed tomographic comparison

    Directory of Open Access Journals (Sweden)

    Enrique Oltra

    2017-02-01

    Full Text Available Objectives Recently, bioceramic sealers like EndoSequence BC Sealer (BC Sealer have been introduced and are being used in endodontic practice. However, this sealer has limited research related to its retreatability. Hence, the aim of this study was to evaluate the retreatability of two sealers, BC Sealer as compared with AH Plus using micro-computed tomographic (micro-CT analysis. Materials and Methods Fifty-six extracted human maxillary incisors were instrumented and randomly divided into 4 groups of 14 teeth: 1A, gutta-percha, AH Plus retreated with chloroform; 1B, gutta-percha, AH Plus retreated without chloroform; 2A, gutta-percha, EndoSequence BC Sealer retreated with chloroform; 2B, gutta-percha, EndoSequence BC Sealer retreated without chloroform. Micro-CT scans were taken before and after obturation and retreatment and analyzed for the volume of residual material. The specimens were longitudinally sectioned and digitized images were taken with the dental operating microscope. Data was analyzed using an ANOVA and a post-hoc Tukey test. Fisher exact tests were performed to analyze the ability to regain patency. Results There was significantly less residual root canal filling material in the AH Plus groups retreated with chloroform as compared to the others. The BC Sealer samples retreated with chloroform had better results than those retreated without chloroform. Furthermore, patency could be re-established in only 14% of teeth in the BC Sealer without chloroform group. Conclusion The results of this study demonstrate that the BC Sealer group had significantly more residual filling material than the AH Plus group regardless of whether or not both sealers were retreated with chloroform.

  1. Evaluation of quality of tomographs of Rio de Janeiro state, Brazil

    International Nuclear Information System (INIS)

    Travassos, P.C.B.; Belem, V.R.; Magalhaes, L.A.; Almeida, C.E.A. de

    2014-01-01

    Computerized tomographs used in 56 institutions in the state of Rio de Janeiro were evaluated. Criteria of image quality and dosimetry were submitted. The results showed that some not performed optimize their protocols examinations or perform wrongly, which results in an increase in the dose received by patients, and an image in compromised quality. (author)

  2. Determination of pressure and load characteristics of flexible revolving wings by means of tomographic PIV

    NARCIS (Netherlands)

    van de Meerendonk, R.; Perçin, M.; van Oudheusden, B.W.

    2016-01-01

    This study explores the flow field and fluid-dynamic loads generated by revolving low-aspect-ratio wings. The pressure field and load characteristics are successfully reconstructed from the phase-locked tomographic measurements in three independently measured volumes along the span of the wing. The

  3. Tomographic Image Reconstruction Using an Interpolation Method for Tree Decay Detection

    Science.gov (United States)

    Hailin Feng; Guanghui Li; Sheng Fu; Xiping Wang

    2014-01-01

    Stress wave velocity has been traditionally regarded as an indicator of the extent of damage inside wood. This paper aimed to detect internal decay of urban trees through reconstructing tomographic image of the cross section of a tree trunk. A grid model covering the cross section area of a tree trunk was defined with some assumptions. Stress wave data were processed...

  4. Rapid tomographic reconstruction based on machine learning for time-resolved combustion diagnostics

    Science.gov (United States)

    Yu, Tao; Cai, Weiwei; Liu, Yingzheng

    2018-04-01

    Optical tomography has attracted surged research efforts recently due to the progress in both the imaging concepts and the sensor and laser technologies. The high spatial and temporal resolutions achievable by these methods provide unprecedented opportunity for diagnosis of complicated turbulent combustion. However, due to the high data throughput and the inefficiency of the prevailing iterative methods, the tomographic reconstructions which are typically conducted off-line are computationally formidable. In this work, we propose an efficient inversion method based on a machine learning algorithm, which can extract useful information from the previous reconstructions and build efficient neural networks to serve as a surrogate model to rapidly predict the reconstructions. Extreme learning machine is cited here as an example for demonstrative purpose simply due to its ease of implementation, fast learning speed, and good generalization performance. Extensive numerical studies were performed, and the results show that the new method can dramatically reduce the computational time compared with the classical iterative methods. This technique is expected to be an alternative to existing methods when sufficient training data are available. Although this work is discussed under the context of tomographic absorption spectroscopy, we expect it to be useful also to other high speed tomographic modalities such as volumetric laser-induced fluorescence and tomographic laser-induced incandescence which have been demonstrated for combustion diagnostics.

  5. Determination of instantaneous pressure in a transonic base flow using four-pulse tomographic PIV

    NARCIS (Netherlands)

    Blinde, P.L.; Lynch, K.P.; Schrijer, F.F.J.; Van Oudheusden, B.W.

    2015-01-01

    A tomographic four-pulse PIV system is used in a transonic axisymmetric base flow experiment at a nominal free stream Mach number of 0.7, with the objective to obtain flow acceleration and pressure data. The PIV system, consisting of two double-pulse lasers and twelve cameras, allows acquiring two

  6. Large-scale volumetric pressure from tomographic PTV with HFSB tracers

    Science.gov (United States)

    Schneiders, Jan F. G.; Caridi, Giuseppe C. A.; Sciacchitano, Andrea; Scarano, Fulvio

    2016-11-01

    The instantaneous volumetric pressure in the near-wake of a truncated cylinder is measured by use of tomographic particle tracking velocimetry (PTV) using helium-filled soap bubbles (HFSB) as tracers. The measurement volume is several orders of magnitude larger than that reported in tomographic experiments dealing with pressure from particle image velocimetry (PIV). The near-wake of a truncated cylinder installed on a flat plate ( Re D = 3.5 × 104) features both wall-bounded turbulence and large-scale unsteady flow separation. The instantaneous pressure is calculated from the time-resolved 3D velocity distribution by invoking the momentum equation. The experiments are conducted simultaneously with surface pressure measurements intended for validation of the technique. The study shows that time-averaged pressure and root-mean-squared pressure fluctuations can be accurately measured both in the fluid domain and at the solid surface by large-scale tomographic PTV with HFSB as tracers, with significant reduction in manufacturing complexity for the wind-tunnel model and circumventing the need to install pressure taps or transducers. The measurement over a large volume eases the extension toward the free-stream regime, providing a reliable boundary condition for the solution of the Poisson equation for pressure. The work demonstrates, in the case of the flow past a truncated cylinder, the use of HFSB tracer particles for pressure measurement in air flows in a measurement volume that is two orders of magnitude larger than that of conventional tomographic PIV.

  7. Spiral computed tomographic imaging related to computerized ultrasonographic images of carotid plaque morphology and histology

    DEFF Research Database (Denmark)

    Grønholdt, Marie-Louise; Wagner, A; Wiebe, B M

    2001-01-01

    Echolucency of carotid atherosclerotic plaques, as evaluated by computerized B-mode ultrasonographic images, has been associated with an increased incidence of brain infarcts on cerebral computed tomographic scans. We tested the hypotheses that characterization of carotid plaques on spiral comput...

  8. Characteristics of high-risk coronary plaques identified by computed tomographic angiography and associated prognosis

    DEFF Research Database (Denmark)

    Thomsen, Camilla; Abdulla, Jawdat

    2016-01-01

    To clarify the potential role of coronary computed tomographic angiography (CCTA) in characterizing and prognosticating high-risk coronary plaques. A systematic review and meta-analysis were conducted to compare high-risk vs. low-risk plaques and culprit vs. non-culprit lesions in patients with a...

  9. Connections model for tomographic images reconstruction; Modelo conexionista para reconstrucao de imagens tomograficas

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, R.G.S.; Pela, C.A.; Roque, S.F. A.C. [Departamento de Fisica e Matematica (FFCLRP) USP. Av. Bandeirantes, 3900- 14040- 901- Ribeirao Preto, Sao Paulo (Brazil)

    1998-12-31

    This paper shows an artificial neural network with an adequately topology for tomographic image reconstruction. The associated error function is derived and the learning algorithm is make. The simulated results are presented and demonstrate the existence of a generalized solution for nets with linear activation function. (Author)

  10. ECAT: a new computerized tomographic imaging system for position-emitting radiopharmaceuticals

    International Nuclear Information System (INIS)

    Phelps, M.E.; Hoffman, E.J.; Huang, S.C.; Kuhl, D.E.

    1977-01-01

    The ECAT was designed and developed as a complete computerized positron radionuclide imaging system capable of providing high contrast, high resolution, quantitative images in 2 dimensional and tomographic formats. Flexibility, in its various image mode options, allows it to be used for a wide variety of imaging problems

  11. Tomographic site characterization using CPT, ERT, and GPR. Innovative Technology Summary Report

    International Nuclear Information System (INIS)

    None

    2000-01-01

    ARA developed a geophysical tomographic system that incorporates results from Electrical Resistivity Tomography (ERT) measurements and Ground Penetrating Radar (GPR) Tomography measurements. Both methods are useful for imaging subsurface structures and processes, however, GPR is more effective in sandy material and ERT is more effective in clayey material. CPT or drilling is used to deploy the electrodes in the subsurface

  12. Investigating Gravity Waves in Polar Mesospheric Clouds Using Tomographic Reconstructions of AIM Satellite Imagery

    Science.gov (United States)

    Hart, V. P.; Taylor, M. J.; Doyle, T. E.; Zhao, Y.; Pautet, P.-D.; Carruth, B. L.; Rusch, D. W.; Russell, J. M.

    2018-01-01

    This research presents the first application of tomographic techniques for investigating gravity wave structures in polar mesospheric clouds (PMCs) imaged by the Cloud Imaging and Particle Size instrument on the NASA AIM satellite. Albedo data comprising consecutive PMC scenes were used to tomographically reconstruct a 3-D layer using the Partially Constrained Algebraic Reconstruction Technique algorithm and a previously developed "fanning" technique. For this pilot study, a large region (760 × 148 km) of the PMC layer (altitude 83 km) was sampled with a 2 km horizontal resolution, and an intensity weighted centroid technique was developed to create novel 2-D surface maps, characterizing the individual gravity waves as well as their altitude variability. Spectral analysis of seven selected wave events observed during the Northern Hemisphere 2007 PMC season exhibited dominant horizontal wavelengths of 60-90 km, consistent with previous studies. These tomographic analyses have enabled a broad range of new investigations. For example, a clear spatial anticorrelation was observed between the PMC albedo and wave-induced altitude changes, with higher-albedo structures aligning well with wave troughs, while low-intensity regions aligned with wave crests. This result appears to be consistent with current theories of PMC development in the mesopause region. This new tomographic imaging technique also provides valuable wave amplitude information enabling further mesospheric gravity wave investigations, including quantitative analysis of their hemispheric and interannual characteristics and variations.

  13. Processing of acquisition data for a time of flight positron tomograph

    International Nuclear Information System (INIS)

    Robert, G.

    1987-10-01

    After a review of basic principles concerning the time of flight positron tomography, the LETI positron tomograph is briefly described. For performance optimization (acquisition, calibration, image reconstruction), various specialized operators have been designed: the realization of the acquisition system is presented [fr

  14. Computed Tomographic Airway Morphology in Chronic Obstructive Pulmonary Disease. Remodeling or Innate Anatomy?

    Science.gov (United States)

    Diaz, Alejandro A; Estépar, Raul San José; Washko, George R

    2016-01-01

    Computed tomographic measures of central airway morphology have been used in clinical, epidemiologic, and genetic investigation as an inference of the presence and severity of small-airway disease in smokers. Although several association studies have brought us to believe that these computed tomographic measures reflect airway remodeling, a careful review of such data and more recent evidence may reveal underappreciated complexity to these measures and limitations that prompt us to question that belief. This Perspective offers a review of seminal papers and alternative explanations of their data in the light of more recent evidence. The relationships between airway morphology and lung function are observed in subjects who never smoked, implying that native airway structure indeed contributes to lung function; computed tomographic measures of central airways such as wall area, lumen area, and total bronchial area are smaller in smokers with chronic obstructive pulmonary disease versus those without chronic obstructive pulmonary disease; and the airways are smaller as disease severity increases. The observations suggest that (1) native airway morphology likely contributes to the relationships between computed tomographic measures of airways and lung function; and (2) the presence of smaller airways in those with chronic obstructive pulmonary disease versus those without chronic obstructive pulmonary disease as well as their decrease with disease severity suggests that smokers with chronic obstructive pulmonary disease may simply have smaller airways to begin with, which put them at greater risk for the development of smoking-related disease.

  15. Pressure estimation from single-snapshot tomographic PIV in a turbulent boundary layer

    NARCIS (Netherlands)

    Schneiders, J.F.G.; Pröbsting, S.; Dwight, R.P.; Van Oudheusden, B.W.; Scarano, F.

    2016-01-01

    A method is proposed to determine the instantaneous pressure field from a single tomographic PIV velocity snapshot and is applied to a flat-plate turbulent boundary layer. The main concept behind the single-snapshot pressure evaluation method is to approximate the flow acceleration using the

  16. 3D velocity measurements in a premixed flame by tomographic PIV

    International Nuclear Information System (INIS)

    Tokarev, M P; Sharaborin, D K; Lobasov, A S; Chikishev, L M; Dulin, V M; Markovich, D M

    2015-01-01

    Tomographic particle image velocimetry (PIV) has become a standard tool for 3D velocity measurements in non-reacting flows. However, the majority of the measurements in flows with combustion are limited to small resolved depth compared to the size of the field of view (typically 1 : 10). The limitations are associated with inhomogeneity of the volume illumination and the non-uniform flow seeding, the optical distortions and errors in the 3D calibration, and the unwanted flame luminosity. In the present work, the above constraints were overcome for the tomographic PIV experiment in a laminar axisymmetric premixed flame. The measurements were conducted for a 1 : 1 depth-to-size ratio using a system of eight CCD cameras and a 200 mJ pulsed laser. The results show that camera calibration based on the triangulation of the tracer particles in the non-reacting conditions provided reliable accuracy for the 3D image reconstruction in the flame. The modification of the tomographic reconstruction allowed a posteriori removal of unwanted bright objects, which were located outside of the region of interest but affected the reconstruction quality. This study reports on a novel experience for the instantaneous 3D velocimetry in laboratory-scale flames by using tomographic PIV. (paper)

  17. An efficient and accurate approach to MTE-MART for time-resolved tomographic PIV

    NARCIS (Netherlands)

    Lynch, KP; Scarano, F.

    2015-01-01

    The motion-tracking-enhanced MART (MTE-MART; Novara et al. in Meas Sci Technol 21:035401, 2010) has demonstrated the potential to increase the accuracy of tomographic PIV by the combined use of a short sequence of non-simultaneous recordings. A clear bottleneck of the MTE-MART technique has been

  18. An efficient and accurate approach to MTE-MART for time-resolved tomographic PIV

    NARCIS (Netherlands)

    Lynch, K.P.; Scarano, F.

    2015-01-01

    The motion-tracking-enhanced MART (MTE-MART; Novara et al. in Meas Sci Technol 21:035401, 2010) has demonstrated the potential to increase the accuracy of tomographic PIV by the combined use of a short sequence of non-simultaneous recordings. A clear bottleneck of the MTE-MART technique has been its

  19. Ratios between effective doses for tomographic and mathematician models due to internal exposure of photons

    International Nuclear Information System (INIS)

    Lima, F.R.A.; Kramer, R.; Khoury, H.J.; Santos, A.M.; Loureiro, E.C.M.

    2005-01-01

    The development of new and sophisticated Monte Carlo codes and tomographic human phantoms or voxels motivated the International Commission on Radiological Protection (ICRP) to revise the traditional models of exposure, which have been used to calculate effective dose coefficients for organs and tissues based on mathematician phantoms known as MIRD5. This paper shows the results of calculations using tomographic phantoms MAX (Male Adult voXel) and FAX (Female Adult voXel), recently developed by the authors as well as with the phantoms ADAM and EVA, of specific genres, type MIRD5, coupled to the EGS4 Monte Carlo and MCNP4C codes, for internal exposure with photons of energies between 10 keV and 4 MeV to several organs sources. Effective Doses for both models, tomographic and mathematician, will be compared separately as a function of the Monte Carlo code replacement, of compositions of human tissues and the anatomy reproduced through tomographs. The results indicate that for photon internal exposure, the use of models of exposure based in voxel, increases the values of effective doses up to 70% for some organs sources considered in this study, when compared with the corresponding results obtained with phantoms of MIRD-5 type

  20. First tomographic image of neutron capture rate in a BNCT facility

    Energy Technology Data Exchange (ETDEWEB)

    Minsky, D.M., E-mail: minsky@tandar.cnea.gov.ar [Gerencia de Investigacion y Aplicaciones, CAC, CNEA, Av. Gral. Paz 1499 (B1650KNA), San Martin, Prov. Bs. As. (Argentina)] [Escuela de Ciencia y Tecnologia, , UNSAM, M. de Irigoyen 3100 (1650), San Martin, Prov. Bs. As. (Argentina)] [Conicet, Av. Rivadavia 1917 (C1033AAJ), Buenos Aires (Argentina); Valda, A.A. [Gerencia de Investigacion y Aplicaciones, CAC, CNEA, Av. Gral. Paz 1499 (B1650KNA), San Martin, Prov. Bs. As. (Argentina)] [Escuela de Ciencia y Tecnologia, , UNSAM, M. de Irigoyen 3100 (1650), San Martin, Prov. Bs. As. (Argentina); Kreiner, A.J. [Gerencia de Investigacion y Aplicaciones, CAC, CNEA, Av. Gral. Paz 1499 (B1650KNA), San Martin, Prov. Bs. As. (Argentina)] [Escuela de Ciencia y Tecnologia, , UNSAM, M. de Irigoyen 3100 (1650), San Martin, Prov. Bs. As. (Argentina)] [Conicet, Av. Rivadavia 1917 (C1033AAJ), Buenos Aires (Argentina); Green, S.; Wojnecki, C. [School of Physics and Astronomy, University of Birmingham, B15 2 TT (United Kingdom)] [Department of Medical Physics, University Hospital Birmingham, Birmingham B15 2TH (United Kingdom); Ghani, Z. [Department of Medical Physics, University Hospital Birmingham, Birmingham B15 2TH (United Kingdom)

    2011-12-15

    This work discusses the development of online dosimetry of the boron dose via Single Photon Emission Computed Tomography (SPECT) during a BNCT treatment irradiation. Such a system will allow the online computation of boron dose maps without the large current uncertainties in the assessment of the boron concentration in different tissues. The first tomographic boron dose image with a SPECT prototype is shown.

  1. Constraining fault interpretation through tomographic velocity gradients: application to northern Cascadia

    Directory of Open Access Journals (Sweden)

    K. Ramachandran

    2012-02-01

    Full Text Available Spatial gradients of tomographic velocities are seldom used in interpretation of subsurface fault structures. This study shows that spatial velocity gradients can be used effectively in identifying subsurface discontinuities in the horizontal and vertical directions. Three-dimensional velocity models constructed through tomographic inversion of active source and/or earthquake traveltime data are generally built from an initial 1-D velocity model that varies only with depth. Regularized tomographic inversion algorithms impose constraints on the roughness of the model that help to stabilize the inversion process. Final velocity models obtained from regularized tomographic inversions have smooth three-dimensional structures that are required by the data. Final velocity models are usually analyzed and interpreted either as a perturbation velocity model or as an absolute velocity model. Compared to perturbation velocity model, absolute velocity models have an advantage of providing constraints on lithology. Both velocity models lack the ability to provide sharp constraints on subsurface faults. An interpretational approach utilizing spatial velocity gradients applied to northern Cascadia shows that subsurface faults that are not clearly interpretable from velocity model plots can be identified by sharp contrasts in velocity gradient plots. This interpretation resulted in inferring the locations of the Tacoma, Seattle, Southern Whidbey Island, and Darrington Devil's Mountain faults much more clearly. The Coast Range Boundary fault, previously hypothesized on the basis of sedimentological and tectonic observations, is inferred clearly from the gradient plots. Many of the fault locations imaged from gradient data correlate with earthquake hypocenters, indicating their seismogenic nature.

  2. Designs for a quantum electron microscope.

    Science.gov (United States)

    Kruit, P; Hobbs, R G; Kim, C-S; Yang, Y; Manfrinato, V R; Hammer, J; Thomas, S; Weber, P; Klopfer, B; Kohstall, C; Juffmann, T; Kasevich, M A; Hommelhoff, P; Berggren, K K

    2016-05-01

    One of the astounding consequences of quantum mechanics is that it allows the detection of a target using an incident probe, with only a low probability of interaction of the probe and the target. This 'quantum weirdness' could be applied in the field of electron microscopy to generate images of beam-sensitive specimens with substantially reduced damage to the specimen. A reduction of beam-induced damage to specimens is especially of great importance if it can enable imaging of biological specimens with atomic resolution. Following a recent suggestion that interaction-free measurements are possible with electrons, we now analyze the difficulties of actually building an atomic resolution interaction-free electron microscope, or "quantum electron microscope". A quantum electron microscope would require a number of unique components not found in conventional transmission electron microscopes. These components include a coherent electron beam-splitter or two-state-coupler, and a resonator structure to allow each electron to interrogate the specimen multiple times, thus supporting high success probabilities for interaction-free detection of the specimen. Different system designs are presented here, which are based on four different choices of two-state-couplers: a thin crystal, a grating mirror, a standing light wave and an electro-dynamical pseudopotential. Challenges for the detailed electron optical design are identified as future directions for development. While it is concluded that it should be possible to build an atomic resolution quantum electron microscope, we have also identified a number of hurdles to the development of such a microscope and further theoretical investigations that will be required to enable a complete interpretation of the images produced by such a microscope. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  3. Studies of the inductively coupled plasma via tomographic reconstruction: II. Experimental system

    International Nuclear Information System (INIS)

    Marshall, K.A.; Monnig, C.A.; Rayson, G.D.; Hieftje, G.M.

    1986-01-01

    Spatially resolved diagnostic studies of the Inductively Coupled Plasma (ICP) have generally relied upon the Abel inversion process to transform lateral projection data into radially resolved emission or absorption profiles. Unfortunately, Abel transformation is known to possess several significant drawbacks. The validity of the radial profiles obtained from the Abel-inversion process is significantly degraded by even small amounts of noise in the lateral emission data. In addition, the Abel-inversion technique requires a cylindrically symmetrical object in order to faithfully produce reconstructions. One method of avoiding these problems is to use the more general method of tomographic reconstruction for spatially resolved studies in the ICP. The experimental requirements of tomographic reconstruction, however, necessitate a rather elaborate experimental system. The large number of angular projections, resolution elements per projection, and the sheer volume of data collected makes tomographic reconstruction prohibitively time consuming if an automated, multi-channel collection scheme is not employed. In this study, an experimental system was designed to permit tomographic characterization of a laboratory ICP. The system employs a z-theta translation stage, a silicon intensified target vidicon detector and a laboratory computer for system automation (see figure). A typical data collection scheme is to obtain 60 projections with 100-point resolution per projection. These profiles are collected every 2 mm on the vertical axis, requiring 15 profiles over a 30 mm plasma height. This process results in approximately 90,000 data points, which can be collected within an hour on this system. Tomographic reconstruction is achieved with the use of a VAX-780 computer. The system employed is described and the operating characteristics of the apparatus are discussed

  4. Resolving vorticity and dissipation in a turbulent boundary layer by tomographic PTV and VIC+

    Science.gov (United States)

    Schneiders, Jan F. G.; Scarano, Fulvio; Elsinga, Gerrit E.

    2017-04-01

    The existing time-resolved tomographic particle image velocimetry (PIV) measurements by Jodai and Elsinga (J Fluid Mech 795:611-633; Jodai, Elsinga, J Fluid Mech 795:611-633, 2016) in a turbulent boundary layer ( Re θ = 2038) are reprocessed using tomographic particle tracking velocimetry (PTV) and vortex-in-cell-plus (VIC+). The resulting small-scale flow properties, i.e. vorticity and turbulence dissipation, are compared. The VIC+ technique was recently proposed and uses the concept of pouring time into space to increase reconstruction quality of instantaneous velocity. The tomographic PTV particle track measurements are interpolated using VIC+ to a dense grid, making use of both particle velocity and Lagrangian acceleration. Comparison of the vortical structures by visualization of isosurfaces of vorticity magnitude shows that the two methods return similar coherent vortical structures, but their strength in terms of vorticity magnitude is increased when using VIC+, which suggests an improvement in spatial resolution. Further statistical evaluation shows that the root mean square (rms) of vorticity fluctuations from tomographic PIV is approximately 40% lower in comparison to a reference profile available from a DNS simulation, while the VIC+ technique returns rms vorticity fluctuations to within 10% of the reference. The dissipation rate is heavily underestimated by tomographic PIV with approximately 50% damping, whereas the VIC+ analysis yields a dissipation rate to within approximately 5% for y + > 25. The fact that dissipation can be directly measured by a volumetric experiment is novel. It differs from existing approaches that involve 2d measurements combined with isotropic turbulence assumptions or apply corrections based on sub-grid scale turbulence modelling. Finally, the study quantifies the spatial response of VIC+ with a sine-wave lattice analysis. The results indicate a twofold increase of spatial resolution with respect to cross

  5. Preliminary study of an angiographic and angio-tomographic technique based on K-edge filters

    Energy Technology Data Exchange (ETDEWEB)

    Golosio, Bruno; Brunetti, Antonio [Dipartimento POLCOMING, Istituto di Matematica e Fisica, Università di Sassari, 07100 Sassari (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Cagliari (Italy); Oliva, Piernicola; Carpinelli, Massimo [Dipartimento di Chimica e Farmacia, Università di Sassari, 07100 Sassari (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Cagliari (Italy); Luca Masala, Giovanni [Dipartimento di Chimica e Farmacia, Università di Sassari, 07100 Sassari (Italy); Meloni, Francesco [Unità operativa di Diagnostica per immagini Asl n. 1, Ospedale Civile SS Annunziata, 07100 Sassari (Italy); Battista Meloni, Giovanni [Istituto di Scienze Radiologiche, Università di Sassari, 07100 Sassari (Italy)

    2013-08-14

    Digital Subtraction Angiography is commonly affected by artifacts due to the patient movements during the acquisition of the images without and with the contrast medium. This paper presents a preliminary study on an angiographic and angio-tomographic technique based on the quasi-simultaneous acquisition of two images, obtained using two different filters at the exit of an X-ray tube. One of the two filters (K-edge filter) contains the same chemical element used as a contrast agent (gadolinium in this study). This filter absorbs more radiation with energy just above the so called K-edge energy of gadolinium than the radiation with energy just below it. The other filter (an aluminium filter in this study) is simply used to suppress the low-energy contribution to the spectrum. Using proper calibration curves, the two images are combined to obtain an image of the contrast agent distribution. In the angio-tomographic application of the proposed technique two images, corresponding to the two filter types, are acquired for each viewing angle of the tomographic scan. From the two tomographic reconstructions, it is possible to obtain a three-dimensional map of the contrast agent distribution. The technique was tested on a sample consisting of a rat skull placed inside a container filled with water. Six small cylinders with 4.7 mm internal diameter containing the contrast medium at different concentrations were placed inside the skull. In the plain angiographic application of the technique, five out of six cylinders were visible, with gadolinium concentration down to 0.96%. In the angio-tomographic application, all six cylinders were visible, with gadolinium concentration down to 0.49%. This preliminary study shows that the proposed technique can provide images of the contrast medium at low concentration without most of the artifacts that are present in images produced by conventional techniques. The results encourage further investigation on the feasibility of a clinical

  6. Miniaturized integration of a fluorescence microscope

    Science.gov (United States)

    Ghosh, Kunal K.; Burns, Laurie D.; Cocker, Eric D.; Nimmerjahn, Axel; Ziv, Yaniv; Gamal, Abbas El; Schnitzer, Mark J.

    2013-01-01

    The light microscope is traditionally an instrument of substantial size and expense. Its miniaturized integration would enable many new applications based on mass-producible, tiny microscopes. Key prospective usages include brain imaging in behaving animals towards relating cellular dynamics to animal behavior. Here we introduce a miniature (1.9 g) integrated fluorescence microscope made from mass-producible parts, including semiconductor light source and sensor. This device enables high-speed cellular-level imaging across ∼0.5 mm2 areas in active mice. This capability allowed concurrent tracking of Ca2+ spiking in >200 Purkinje neurons across nine cerebellar microzones. During mouse locomotion, individual microzones exhibited large-scale, synchronized Ca2+ spiking. This is a mesoscopic neural dynamic missed by prior techniques for studying the brain at other length scales. Overall, the integrated microscope is a potentially transformative technology that permits distribution to many animals and enables diverse usages, such as portable diagnostics or microscope arrays for large-scale screens. PMID:21909102

  7. Optical alignment using the Point Source Microscope

    Science.gov (United States)

    Parks, Robert E.; Kuhn, William P.

    2005-08-01

    We give an example of a Point Source Microscope (PSM) and describe its uses as an aid in the alignment of optical systems including the referencing of optical to mechanical datums. The PSM is a small package (about 100x150x30 mm), including a point source of light, beam splitter, microscope objective and digital CCD camera to detect the reflected light spot. A software package in conjunction with a computer video display locates the return image in three degrees of freedom relative to an electronic spatial reference point. The PSM also includes a Koehler illumination source so it may be used as a portable microscope for ordinary imaging and the microscope can be zoomed under computer control. For added convenience, the laser diode point source can be made quite bright to facilitate initial alignment under typical laboratory lighting conditions. The PSM is particularly useful in aligning optical systems that do not have circular symmetry or are distributed in space such as off-axis systems. The PSM is also useful for referencing the centers of curvatures of optical surfaces to mechanical datums of the structure in which the optics are mounted. By removing the microscope objective the PSM can be used as an electronic autocollimator because of the infinite conjugate optical design.

  8. Optical modeling of Fresnel zoneplate microscopes.

    Science.gov (United States)

    Naulleau, Patrick P; Mochi, Iacopo; Goldberg, Kenneth A

    2011-07-10

    Defect free masks remain one of the most significant challenges facing the commercialization of extreme ultraviolet (EUV) lithography. Progress on this front requires high-performance wavelength-specific metrology of EUV masks, including high-resolution and aerial-image microscopy performed near the 13.5 nm wavelength. Arguably the most cost-effective and rapid path to proliferating this capability is through the development of Fresnel zoneplate-based microscopes. Given the relative obscurity of such systems, however, modeling tools are not necessarily optimized to deal with them and their imaging properties are poorly understood. Here we present a modeling methodology to analyze zoneplate microscopes based on commercially available optical modeling software and use the technique to investigate the imaging performance of an off-axis EUV microscope design. The modeling predicts that superior performance can be achieved by tilting the zoneplate, making it perpendicular to the chief ray at the center of the field, while designing the zoneplate to explicitly work in that tilted plane. Although the examples presented here are in the realm of EUV mask inspection, the methods described and analysis results are broadly applicable to zoneplate microscopes in general, including full-field soft-x-ray microscopes routinely used in the synchrotron community. © 2011 Optical Society of America

  9. A frameless stereotaxic operating microscope for neurosurgery

    International Nuclear Information System (INIS)

    Friets, E.M.; Strohbehn, J.W.; Hatch, J.F.; Roberts, D.W.

    1989-01-01

    A new system, which we call the frameless stereotaxic operating microscope, is discussed. Its purpose is to display CT or other image data in the operating microscope in the correct scale, orientation, and position without the use of a stereotaxic frame. A nonimaging ultrasonic rangefinder allows the position of the operating microscope and the position of the patient to be determined. Discrete fiducial points on the patient's external anatomy are located in both image space and operating room space, linking the image data and the operating room. Physician-selected image information, e.g., tumor contours or guidance to predetermined targets, is projected through the optics of the operating microscope using a miniature cathode ray tube and a beam splitter. Projected images superpose the surgical field, reconstructed from image data to match the focal plane of the operating microscope. The algorithms on which the system is based are described, and the sources and effects of errors are discussed. The system's performance is simulated, providing an estimate of accuracy. Two phantoms are used to measure accuracy experimentally. Clinical results and observations are given

  10. Optical modeling of Fresnel zoneplate microscopes

    International Nuclear Information System (INIS)

    Naulleau, Patrick P.; Mochi, Iacopo; Goldberg, Kenneth A.

    2011-01-01

    Defect free masks remain one of the most significant challenges facing the commercialization of extreme ultraviolet (EUV) lithography. Progress on this front requires high-performance wavelength-specific metrology of EUV masks, including high-resolution and aerial-image microscopy performed near the 13.5 nm wavelength. Arguably the most cost-effective and rapid path to proliferating this capability is through the development of Fresnel zoneplate-based microscopes. Given the relative obscurity of such systems, however, modeling tools are not necessarily optimized to deal with them and their imaging properties are poorly understood. Here we present a modeling methodology to analyze zoneplate microscopes based on commercially available optical modeling software and use the technique to investigate the imaging performance of an off-axis EUV microscope design. The modeling predicts that superior performance can be achieved by tilting the zoneplate, making it perpendicular to the chief ray at the center of the field, while designing the zoneplate to explicitly work in that tilted plane. Although the examples presented here are in the realm of EUV mask inspection, the methods described and analysis results are broadly applicable to zoneplate microscopes in general, including full-field soft-x-ray microscopes routinely used in the synchrotron community.

  11. Microscopic fungi as significant sesquiterpene emission sources

    Science.gov (United States)

    HorváTh, Eszter; Hoffer, AndráS.; SebőK, Flóra; Dobolyi, Csaba; Szoboszlay, SáNdor; Kriszt, BaláZs; GelencséR, AndráS.

    2011-08-01

    Among the volatile organic compounds emitted by vegetation, isoprene, monoterpenes, sesquiterpenes, and their derivatives are thought to contribute to secondary organic aerosol formation. Although it is well known that microscopic fungi globally turn over vast amount of carbon by decomposing the organic matter in the soil, vegetation is considered as the exclusive source of biogenic secondary organic aerosol precursors in various atmospheric models. Secondary fungal metabolites including sesquiterpenes have been recognized as characteristic volatile organic compounds emitted by fungi. In the present study, we investigated the rates of sesquiterpene emission of microscopic fungi to establish their potential significance compared to those from vegetation. To sample the headspace of the pure culture of some common fungi, we used an aseptic flow-through apparatus designed for solid phase microextraction in our laboratory. The identified sesquiterpenes in the headspace extracts were quantified for eight strains of microscopic fungi belonging to four different genera. Our results showed that microscopic fungi emit a considerable amount of sesquiterpenes. Based on our first estimations microscopic fungi may be considered as potentially significant sesquiterpene emission sources whose contribution to secondary organic aerosol formation may be comparable to that of vegetation.

  12. The optics of microscope image formation.

    Science.gov (United States)

    Wolf, David E

    2013-01-01

    Although geometric optics gives a good understanding of how the microscope works, it fails in one critical area, which is explaining the origin of microscope resolution. To accomplish this, one must consider the microscope from the viewpoint of physical optics. This chapter describes the theory of the microscope-relating resolution to the highest spatial frequency that a microscope can collect. The chapter illustrates how Huygens' principle or construction can be used to explain the propagation of a plane wave. It is shown that this limit increases with increasing numerical aperture (NA). As a corollary to this, resolution increases with decreasing wavelength because of how NA depends on wavelength. The resolution is higher for blue light than red light. Resolution is dependent on contrast, and the higher the contrast, the higher the resolution. This last point relates to issues of signal-to-noise and dynamic range. The use of video and new digital cameras has necessitated redefining classical limits such as those of Rayleigh's criterion. Copyright © 2007 Elsevier Inc. All rights reserved.

  13. Determination of the parameters of a microscopic object from a complex response of a differential microscope

    International Nuclear Information System (INIS)

    Baranov, D V; Egorov, Alexander A; Zolotov, Evgenii M; Svidzinsky, K K

    1998-01-01

    An analysis of the amplitude and phase of a complex response of a heterodyne differential microscope was used to demonstrate experimentally the feasibility of determination of the parameters of a composite microscopic object representing a combination of a step with a groove. (laser applications and other topics in quantum electronics)

  14. HANDY MICROSCOPIC CLOSE-RANGE VIDEOGRAMMETRY

    Directory of Open Access Journals (Sweden)

    F. Esmaeili

    2017-09-01

    Full Text Available The modeling of small-scale objects is used in different applications such as medicine, industry, and cultural heritage. The capability of modeling small-scale objects using imaging with the help of hand USB digital microscopes and use of videogrammetry techniques has been implemented and evaluated in this paper. Use of this equipment and convergent imaging of the environment for modeling, provides an appropriate set of images for generation of three-dimensional models. The results of the measurements made with the help of a microscope micrometer calibration ruler have demonstrated that self-calibration of a hand camera-microscope set can help obtain a three-dimensional detail extraction precision of about 0.1 millimeters on small-scale environments.

  15. Environmental TEM in an Aberration Corrected Microscope

    DEFF Research Database (Denmark)

    Hansen, Thomas Willum; Wagner, Jakob Birkedal

    ‐resolution imaging. A gaseous atmosphere in the pole‐piece gap of the objective lens of the microscope alters both the incoming electron wave prior to interaction with the sample and the outgoing wave below the sample. Whereas conventional TEM samples are usually thin (below 10‐20 nm), the gas in the environmental...... the microscope column. The effects of gas on the electron wave in the objective lens are not well understood and needs further attention. Imaging samples with a simple geometry, such as gold particles on a flat graphene substrate and analyzing the variations in contrast, provides a means for understanding...... results from imaging in various elemental as well as di‐molecular gases and their effect on imaging and spectroscopy in the environmental transmission electron microscope....

  16. Scanning probe microscope dimensional metrology at NIST

    International Nuclear Information System (INIS)

    Kramar, John A; Dixson, Ronald; Orji, Ndubuisi G

    2011-01-01

    Scanning probe microscope (SPM) dimensional metrology efforts at the US National Institute of Standards and Technology (NIST) are reviewed in this paper. The main SPM instruments for realizing the International System of Units (SI) are the Molecular Measuring Machine, the calibrated atomic force microscope and the critical dimension atomic force microscope. These are optimized for long-distance measurements, three-dimensional measurements over conventional SPM distances and critical dimension or linewidth measurements, respectively. 10 mm distances have been measured with the relative standard uncertainty, u c , of 1.5 × 10 −5 ; step heights at the 100 nm scale have been measured with the relative u c of 2.5 × 10 −3 and sub-micrometer linewidths have been measured with u c = 0.8 nm

  17. Neutron relativistic phenomenological and microscopic optical potential

    International Nuclear Information System (INIS)

    Shen Qing-biao; Feng Da-chun; Zhuo Yi-zhong

    1991-01-01

    In this paper, both the phenomenological and microscopic neutron relativistic optical potentials are presented. The global neutron relativistic phenomenological optical potential (RPOP) based on the available experimental data for various nuclei ranging from C to U with incident energies E n =20--1000 MeV has been obtained through an automatic search of the best parameters by computer. Then the nucleon relativistic microscopic optical potential (RMOP) is studied by utilizing the effective Lagrangian based on the popular Walecka model. Through comparison between the theoretical results and experimental data we shed some insight into both the RMOP and RPOP. Further improvement concerning how to combine the phenomenological potential with the microscopic one in order to reduce the number of free parameters appearing in the RPOP is suggested

  18. Smartphone Magnification Attachment: Microscope or Magnifying Glass

    Science.gov (United States)

    Hergemöller, Timo; Laumann, Daniel

    2017-09-01

    Today smartphones and tablets do not merely pervade our daily life, but also play a major role in STEM education in general, and in experimental investigations in particular. Enabling teachers and students to make use of these new techniques in physics lessons requires supplying capable and affordable applications. Our article presents the improvement of a low-cost technique turning smartphones into powerful magnifying glasses or microscopes. Adding only a 3D-printed clip attached to the smartphone's camera and inserting a small glass bead in this clip enables smartphones to take pictures with up to 780x magnification (see Fig. 1). In addition, the construction of the smartphone attachments helps to explain and examine the differences between magnifying glasses and microscopes, and shows that the widespread term "smartphone microscope" for this technique is inaccurate from a physics educational perspective.

  19. CHAMP (Camera, Handlens, and Microscope Probe)

    Science.gov (United States)

    Mungas, Greg S.; Boynton, John E.; Balzer, Mark A.; Beegle, Luther; Sobel, Harold R.; Fisher, Ted; Klein, Dan; Deans, Matthew; Lee, Pascal; Sepulveda, Cesar A.

    2005-01-01

    CHAMP (Camera, Handlens And Microscope Probe)is a novel field microscope capable of color imaging with continuously variable spatial resolution from infinity imaging down to diffraction-limited microscopy (3 micron/pixel). As a robotic arm-mounted imager, CHAMP supports stereo imaging with variable baselines, can continuously image targets at an increasing magnification during an arm approach, can provide precision rangefinding estimates to targets, and can accommodate microscopic imaging of rough surfaces through a image filtering process called z-stacking. CHAMP was originally developed through the Mars Instrument Development Program (MIDP) in support of robotic field investigations, but may also find application in new areas such as robotic in-orbit servicing and maintenance operations associated with spacecraft and human operations. We overview CHAMP'S instrument performance and basic design considerations below.

  20. CHAMP - Camera, Handlens, and Microscope Probe

    Science.gov (United States)

    Mungas, G. S.; Beegle, L. W.; Boynton, J.; Sepulveda, C. A.; Balzer, M. A.; Sobel, H. R.; Fisher, T. A.; Deans, M.; Lee, P.

    2005-01-01

    CHAMP (Camera, Handlens And Microscope Probe) is a novel field microscope capable of color imaging with continuously variable spatial resolution from infinity imaging down to diffraction-limited microscopy (3 micron/pixel). As an arm-mounted imager, CHAMP supports stereo-imaging with variable baselines, can continuously image targets at an increasing magnification during an arm approach, can provide precision range-finding estimates to targets, and can accommodate microscopic imaging of rough surfaces through a image filtering process called z-stacking. Currently designed with a filter wheel with 4 different filters, so that color and black and white images can be obtained over the entire Field-of-View, future designs will increase the number of filter positions to include 8 different filters. Finally, CHAMP incorporates controlled white and UV illumination so that images can be obtained regardless of sun position, and any potential fluorescent species can be identified so the most astrobiologically interesting samples can be identified.

  1. Development of an ultrasound microscope combined with optical microscope for multiparametric characterization of a single cell.

    Science.gov (United States)

    Arakawa, Mototaka; Shikama, Joe; Yoshida, Koki; Nagaoka, Ryo; Kobayashi, Kazuto; Saijo, Yoshifumi

    2015-09-01

    Biomechanics of the cell has been gathering much attention because it affects the pathological status in atherosclerosis and cancer. In the present study, an ultrasound microscope system combined with optical microscope for characterization of a single cell with multiple ultrasound parameters was developed. The central frequency of the transducer was 375 MHz and the scan area was 80 × 80 μm with up to 200 × 200 sampling points. An inverted optical microscope was incorporated in the design of the system, allowing for simultaneous optical observations of cultured cells. Two-dimensional mapping of multiple ultrasound parameters, such as sound speed, attenuation, and acoustic impedance, as well as the thickness, density, and bulk modulus of specimen/cell under investigation, etc., was realized by the system. Sound speed and thickness of a 3T3-L1 fibroblast cell were successfully obtained by the system. The ultrasound microscope system combined with optical microscope further enhances our understanding of cellular biomechanics.

  2. Compact Microscope Imaging System with Intelligent Controls

    Science.gov (United States)

    McDowell, Mark

    2004-01-01

    The figure presents selected views of a compact microscope imaging system (CMIS) that includes a miniature video microscope, a Cartesian robot (a computer- controlled three-dimensional translation stage), and machine-vision and control subsystems. The CMIS was built from commercial off-the-shelf instrumentation, computer hardware and software, and custom machine-vision software. The machine-vision and control subsystems include adaptive neural networks that afford a measure of artificial intelligence. The CMIS can perform several automated tasks with accuracy and repeatability . tasks that, heretofore, have required the full attention of human technicians using relatively bulky conventional microscopes. In addition, the automation and control capabilities of the system inherently include a capability for remote control. Unlike human technicians, the CMIS is not at risk of becoming fatigued or distracted: theoretically, it can perform continuously at the level of the best human technicians. In its capabilities for remote control and for relieving human technicians of tedious routine tasks, the CMIS is expected to be especially useful in biomedical research, materials science, inspection of parts on industrial production lines, and space science. The CMIS can automatically focus on and scan a microscope sample, find areas of interest, record the resulting images, and analyze images from multiple samples simultaneously. Automatic focusing is an iterative process: The translation stage is used to move the microscope along its optical axis in a succession of coarse, medium, and fine steps. A fast Fourier transform (FFT) of the image is computed at each step, and the FFT is analyzed for its spatial-frequency content. The microscope position that results in the greatest dispersal of FFT content toward high spatial frequencies (indicating that the image shows the greatest amount of detail) is deemed to be the focal position.

  3. The microscopic structure of the hydrogen liquids

    CERN Document Server

    Zoppi, M; Celli, M; Cuello, G J; Formisano, F; Guarini, E; Magli, R; Neumann, M

    2003-01-01

    We have measured the microscopic structure of liquid para-hydrogen by means of a neutron diffraction experiment on the D4C liquids diffractometer at Institute Laue-Langevin (Grenoble, France). This is the first direct neutron diffraction measurement of the static structure factor of hydrogen. The present determination of the microscopic structure of hydrogen is consistent with previous experimental determinations carried out on liquid deuterium and with path integral Monte Carlo simulations. The comparison with recent x-ray determinations is also satisfactory.

  4. Optofluidic microscope with 3D spatial resolution

    DEFF Research Database (Denmark)

    Vig, Asger Laurberg; Marie, Rodolphe; Jensen, Eric

    2010-01-01

    This paper reports on-chip based optical detection with three-dimensional spatial resolution by integration of an optofluidic microscope (OFM) in a microfluidic pinched flow fractionation (PFF) separation device. This setup also enables on-chip particle image velocimetry (PIV). The position...... fluorescence microscope readout. The size separated microspheres are detected by OFM with an accuracy of ≤0.92μm. The position in the height of the channel and the velocity of the separated microspheres are detected with an accuracy of 1.4μm and 0.08 mm/s respectively. Throughout the measurements of the height...

  5. Three-dimensional positioning with optofluidic microscope

    DEFF Research Database (Denmark)

    Vig, Asger Laurberg; Marie, Rodolphe; Jensen, Eric

    2010-01-01

    This paper reports on-chip based optical detection with three-dimensional spatial resolution by integration of an optofluidic microscope (OFM) in a microfluidic pinched flow fractionation (PFF) separation device. This setup also enables on-chip particle image velocimetry (PIV). The position...... a conventional fluorescence microscope as readout. The size separated microspheres are detected by OFM with an accuracy of ≤ 0.92 μm. The position in the height of the channel and the velocity of the separated microspheres are detected with an accuracy of 1.4 μm and 0.08 mm/s respectively. Throughout...

  6. The clinical microscope and direct composite veneer

    DEFF Research Database (Denmark)

    Pascotto, Renata C; Benetti, Ana Raquel

    2010-01-01

    This paper presents the advantages and limitations related to the use of a clinical microscope in restorative dentistry, and it demonstrates the aid of magnification during preparation and restoration of a direct composite veneer. Good illumination and visibility is important to adequately viewin...... the adjacent dental tissues so that the resin composite buildup can mimic natural teeth. The reproduction of details results in a naturally esthetic direct veneer.......This paper presents the advantages and limitations related to the use of a clinical microscope in restorative dentistry, and it demonstrates the aid of magnification during preparation and restoration of a direct composite veneer. Good illumination and visibility is important to adequately viewing...

  7. Microscopic treatment of solute trapping and drag

    Science.gov (United States)

    Humadi, Harith; Hoyt, J. J.; Provatas, Nikolas

    2016-01-01

    The long wavelength limit of a recent microscopic phase-field crystal (PFC) theory of a binary alloy mixture is used to derive an analytical approximation for the segregation coefficient as a function of the interface velocity, and relate it to the two-point correlation function of the liquid and the thermodynamic properties of solid and liquid phases. Our results offer the first analytical derivation of solute segregation from a microscopic model, and support recent molecular dynamics and numerical PFC simulations. Our results also provide an independent framework, motivated from classical density functional theory, from which to elucidate the fundamental nature of solute drag, which is still highly contested in the literature.

  8. An innovative approach in microscopic endodontics

    Science.gov (United States)

    Mittal, Sunandan; Kumar, Tarun; Sharma, Jyotika; Mittal, Shifali

    2014-01-01

    The introduction of the dental operating microscope was a turning point in the history of dentistry. It triggered a rapid transition from the conventional world of macro-dentistry to the precise, detailed world of micro-dentistry. However, working at these higher-power magnifications brings the clinician into the realm where even slight hand movements are disruptive. Physiologic hand tremor is a problem resulting in difficulty in mouth mirror placement. Hence, in this paper, a new instrument was designed to overcome the drawback of hand tremors during microscopic endodontics. PMID:24944459

  9. Microscopic tunneling theory of long Josephson junctions

    DEFF Research Database (Denmark)

    Grønbech-Jensen, N.; Hattel, Søren A.; Samuelsen, Mogens Rugholm

    1992-01-01

    We present a numerical scheme for solving a nonlinear partial integro-differential equation with nonlocal time dependence. The equation describes the dynamics in a long Josephson junction modeled by use of the microscopic theory for tunneling between superconductors. We demonstrate that the detai......We present a numerical scheme for solving a nonlinear partial integro-differential equation with nonlocal time dependence. The equation describes the dynamics in a long Josephson junction modeled by use of the microscopic theory for tunneling between superconductors. We demonstrate...... that the detailed behavior of a solitonic mode (fluxon dynamics) in the junction is different from the results of the conventional perturbed sine-Gordon model....

  10. Microscopic model of a phononic refrigerator

    Science.gov (United States)

    Arrachea, Liliana; Mucciolo, Eduardo R.; Chamon, Claudio; Capaz, Rodrigo B.

    2012-09-01

    We analyze a simple microscopic model to pump heat from a cold to a hot reservoir in a nanomechanical system. The model consists of a one-dimensional chain of masses and springs coupled to a back gate through which a time-dependent perturbation is applied. The action of the gate creates a moving phononic barrier by locally pinning a mass. We solve the problem numerically using a nonequilibrium Green's function technique. For low driving frequencies and for sharp traveling barriers, we show that this microscopic model realizes a phonon refrigerator.

  11. Small-size low-temperature scanning tunnel microscope

    International Nuclear Information System (INIS)

    Al'tfeder, I.B.; Khajkin, M.S.

    1989-01-01

    A small-size scanning tunnel microscope, designed for operation in transport helium-filled Dewar flasks is described. The microscope design contains a device moving the pin to the tested sample surface and a piezoelectric fine positioning device. High vibration protection of the microscope is provided by its suspension using silk threads. The small-size scanning tunnel microscope provides for atomic resolution

  12. 21 CFR 864.3600 - Microscopes and accessories.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Microscopes and accessories. 864.3600 Section 864... Microscopes and accessories. (a) Identification. Microscopes and accessories are optical instruments used to enlarge images of specimens, preparations, and cultures for medical purposes. Variations of microscopes...

  13. Science 101: How Does an Electron Microscope Work?

    Science.gov (United States)

    Robertson, Bill

    2013-01-01

    Contrary to popular opinion, electron microscopes are not used to look at electrons. They are used to look for structure in things that are too small to observe with an optical microscope, or to obtain images that are magnified much more than is obtainable with an optical microscope. To understand how electron microscopes work, it will help to go…

  14. Inverse Problem Approach for the Alignment of Electron Tomographic Series

    International Nuclear Information System (INIS)

    Tran, V.D.; Moreaud, M.; Thiebaut, E.; Denis, L.; Becker, J.M.

    2014-01-01

    In the refining industry, morphological measurements of particles have become an essential part in the characterization catalyst supports. Through these parameters, one can infer the specific physico-chemical properties of the studied materials. One of the main acquisition techniques is electron tomography (or nano-tomography). 3D volumes are reconstructed from sets of projections from different angles made by a Transmission Electron Microscope (TEM). This technique provides a real three-dimensional information at the nano-metric scale. A major issue in this method is the misalignment of the projections that contributes to the reconstruction. The current alignment techniques usually employ fiducial markers such as gold particles for a correct alignment of the images. When the use of markers is not possible, the correlation between adjacent projections is used to align them. However, this method sometimes fails. In this paper, we propose a new method based on the inverse problem approach where a certain criterion is minimized using a variant of the Nelder and Mead simplex algorithm. The proposed approach is composed of two steps. The first step consists of an initial alignment process, which relies on the minimization of a cost function based on robust statistics measuring the similarity of a projection to its previous projections in the series. It reduces strong shifts resulting from the acquisition between successive projections. In the second step, the pre-registered projections are used to initialize an iterative alignment-refinement process which alternates between (i) volume reconstructions and (ii) registrations of measured projections onto simulated projections computed from the volume reconstructed in (i). At the end of this process, we have a correct reconstruction of the volume, the projections being correctly aligned. Our method is tested on simulated data and shown to estimate accurately the translation, rotation and scale of arbitrary transforms. We

  15. Detection of various anatomic patterns of root canals in mandibular incisors using digital periapical radiography, 3 cone-beam computed tomographic scanners, and micro-computed tomographic imaging.

    Science.gov (United States)

    Paes da Silva Ramos Fernandes, Luciana Maria; Rice, Dwight; Ordinola-Zapata, Ronald; Alvares Capelozza, Ana Lucia; Bramante, Clovis Monteiro; Jaramillo, David; Christensen, Heidi

    2014-01-01

    The purpose of this study was to compare the accuracy of digital periapical (PA) radiography and 3 cone-beam computed tomographic (CBCT) scanners in the identification of various internal anatomic patterns in mandibular incisors. Forty mandibular incisors were scanned using micro-computed tomographic imaging as the gold standard to establish the internal anatomic pattern. The number of root canals and internal patterns were classified into type I (single canal, n = 12), type Ia (single oval canal, n = 12), and type III (2 canals, n = 16). The teeth were placed in a human mandible, and digital PA radiography and 3 CBCT scans (Kodak 9000 3D [Carestream Health, Rochester, NY], Veraviewepocs 3De [J Morita MFG Corp, Kyoto, Japan], NewTom 5G [QR Srl, Verona, Italy]) were performed. Two blinded examiners classified each tooth's anatomic pattern, which were then compared with the micro-computed tomographic determinations. Considering type I and type Ia, which both presented with 1 root canal, there was a high degree of accuracy for all methods used (P > .05). The same result was found for type III. When identifying the shape of single canals (type I), CBCT imaging was more accurate compared with PA radiography. Concerning oval canals (type Ia), there was a significant difference between PA radiography and NewTom CBCT (PA radiography = 44%, NewTom = 88%). However, there were no significant differences between the 3 CBCT units. Double-exposure digital PA radiography for mandibular incisors is sufficient for the identification of the number of root canals. All CBCT devices showed improved accuracy in the identification of single root canal anatomy when a narrow canal was present. However, the identification of oval canals was improved only with the NewTom CBCT device. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  16. Nanoparticle Imaging with Polarization Interferometric Nonlinear Confocal Microscope

    OpenAIRE

    Fujita, Kohei; Egami, Chikara

    2014-01-01

    Polarization interferometric nonlinear confocal microscope has been developed for single nanoparticle analysis of drug delivery system (DDS). The microscope is a system based on a low cost and low power continuous wave (CW) laser light source. Also, the microscope observed shape anisotropy of the 200 nm diameter nanoparticle. According to nanoparticle imaging and CTF (contrast transfer function) curve observation of the microscope, three-dimensional resolution of the microscope measured up to...

  17. Spin microscope based on optically detected magnetic resonance

    Science.gov (United States)

    Berman, Gennady P.; Chernobrod, Boris M.

    2007-12-11

    The invention relates to scanning magnetic microscope which has a photoluminescent nanoprobe implanted in the tip apex of an atomic force microscope (AFM), a scanning tunneling microscope (STM) or a near-field scanning optical microscope (NSOM) and exhibits optically detected magnetic resonance (ODMR) in the vicinity of unpaired electron spins or nuclear magnetic moments in the sample material. The described spin microscope has demonstrated nanoscale lateral resolution and single spin sensitivity for the AFM and STM embodiments.

  18. MACROSCOPICAL AND MICROSCOPICAL STUDIES ON THE ...

    African Journals Online (AJOL)

    Caesalpinia crista leaves are bipinnate of about six pairs with alternate leaflets while the stem us fibrous, cylindrical hollow and prickly. Microscopical examination revealed the presence of strained cuticle, straight-walled epidermal cells, paracytic stomata, unicellular covering trichomes, fibres, prisms as well as cluster of ...

  19. Energy electron analyzers raster electron microscope

    International Nuclear Information System (INIS)

    Dremova, N.N.; Raj, Eh.I.; Robinson, V.N.

    1995-01-01

    Spectrometers of back-scattered and secondary electrons used in a raster electron microscope designed to study multilayer structures and potential relief at the solid-state body surface, are described. Their possible applications are demonstrated using microelectronics devices as an example

  20. Wavelet Transform - A New Mathematical Microscope

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 9; Issue 3. Wavelet Transform - A New Mathematical Microscope. Sachin P Nanavati Prasanta K Panigrahi. General Article Volume 9 Issue 3 March 2004 pp 50-64. Fulltext. Click here to view fulltext PDF. Permanent link:

  1. Microscopic Derivation of Ginzburg-Landau Theory

    DEFF Research Database (Denmark)

    Frank, Rupert; Hainzl, Christian; Seiringer, Robert

    2012-01-01

    We give the first rigorous derivation of the celebrated Ginzburg-Landau (GL) theory, starting from the microscopic Bardeen-Cooper-Schrieffer (BCS) model. Close to the critical temperature, GL arises as an effective theory on the macroscopic scale. The relevant scaling limit is semiclassical...

  2. Exploring the environmental transmission electron microscope

    DEFF Research Database (Denmark)

    Wagner, Jakob B.; Cavalca, Filippo; Damsgaard, Christian D.

    2012-01-01

    of the opportunities that the environmental TEM (ETEM) offers when combined with other in situ techniques will be explored, directly in the microscope, by combining electron-based and photon-based techniques and phenomena. In addition, application of adjacent setups using sophisticated transfer methods...

  3. The Titan Environmental Transmission Electron Microscope

    DEFF Research Database (Denmark)

    Hansen, Thomas Willum; Wagner, Jakob Birkedal; Jinschek, Jörg R.

    2009-01-01

    University of Denmark (DTU) provides a unique combination of techniques for studying materials of interest to the catalytic as well as the electronics and other communities [5]. DTU’s ETEM is based on the FEI Titan platform providing ultrahigh microscope stability pushing the imaging resolution into the sub...

  4. Stick-on microscope for smartphones

    Science.gov (United States)

    Lee, W. M.

    2014-02-01

    In this paper, I demonstrate a low cost light weight microscope device that is compatible with any smartphone camera. The device amplifies the imaging resolution of a smartphone camera by three orders of magnitude from millimeters to sub-micrometers, while costing approximately USD$ 2.

  5. Compact, common path quantitative phase microscopic techniques ...

    Indian Academy of Sciences (India)

    2014-01-05

    Jan 5, 2014 ... One of the ways to retrieve object height/thickness information is to employ quantitative phase microscopic (QPM) techniques. Interferometric QPM techniques are widely used for this. Digital holographic microscopy (DHM) is one of the stateof-the-art methods for quantitative three-dimensional (3D) imaging.

  6. Microscopic polyangeitis, report of a case

    International Nuclear Information System (INIS)

    Malagon, Patricia; Suarez, Martha Lucia

    1998-01-01

    Polyarteritis or microscopic polyangeitis is a systemic necrotizing vasculitis associated with the lung-kidney syndrome. It presents with diffuse alveolar hemorrhage and necrotizing glomerulonephritis with multisystem involvement. A case is presented of a 50 years old male with its clinical and imaging findings

  7. Microscopic Description of Le Chatelier's Principle

    Science.gov (United States)

    Novak, Igor

    2005-01-01

    A simple approach that "demystifies" Le Chatelier's principle (LCP) and simulates students to think about fundamental physical background behind the well-known principles is presented. The approach uses microscopic descriptors of matter like energy levels and populations and does not require any assumption about the fixed amount of substance being…

  8. Of Mechanisms, Microscopes and Methyl isocyanate

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 13; Issue 3. Of Mechanisms, Microscopes and Methyl isocyanate. S Sriramachari Sujata Varadarajan. Face to Face Volume 13 Issue 3 March 2008 pp 292-306. Fulltext. Click here to view fulltext PDF. Permanent link:

  9. Wavelet Transform-A New Mathematical Microscope

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 9; Issue 3. Wavelet Transform - A New Mathematical Microscope. Sachin P Nanavati Prasanta K Panigrahi. General Article Volume 9 Issue 3 March 2004 pp 50-64. Fulltext. Click here to view fulltext PDF. Permanent link:

  10. Reasoning about Magnetism at the Microscopic Level

    Science.gov (United States)

    Cheng, Meng-Fei; Cheng, Yufang; Hung, Shuo-Hsien

    2014-01-01

    Based on our experience of teaching physics in middle and senior secondary school, we have found that students have difficulty in reasoning at the microscopic level. Their reasoning is limited to the observational level so they have problems in developing scientific models of magnetism. Here, we suggest several practical activities and the use of…

  11. A two-dimensional Dirac fermion microscope

    DEFF Research Database (Denmark)

    Bøggild, Peter; Caridad, Jose; Stampfer, Christoph

    2017-01-01

    D electron guns, deflectors, tunable lenses and various detectors. The simulations show how simple objects can be imaged with well-controlled and collimated in-plane beams consisting of relativistic charge carriers. Finally, we discuss the potential of such microscopes for investigating edges...

  12. Development of an electrical impedance computed tomographic two-phase flows analyzer. Annual technical report for program renewal

    Energy Technology Data Exchange (ETDEWEB)

    Jones, O.C.

    1993-05-01

    This progress report details the theoretical development, numerical results, experimental design (mechanical), experimental design (electronic), and experimental results for the research program for the development of an electrical impedance computed tomographic two-phase flow analyzer.

  13. Soil physical and X-ray computed tomographic measurements to investigate small-scale structural differences under strip tillage compared to mulch till and no-till

    Science.gov (United States)

    Pöhlitz, Julia; Rücknagel, Jan; Schlüter, Steffen; Vogel, Hans-Jörg

    2017-04-01

    . Mechanical precompression stress was significantly higher for STBS (141 kPa) than STWS (38 kPa). In addition, the CT image cross sections and the computed tomographic parameters confirmed the mechanically more stable soil structure observed under STBS with a higher initial average pore size but lower porosity and connectivity values compared to STWS. The reason for this is the lack of tillage. On the other hand, tillage at STWS created a loosened, porous and connective substrate. For all variants, the increasing load application led to progressive homogenization processes of the soil structure. At the same time, as stress application increased in all variants, the increase in dry bulk density led to a decrease in average pore size, porosity, and connectivity, while anisotropy increased. It was possible to confirm that strip tillage combines the advantages of no-till and a deeper conservation primary tillage, since on the one hand MT and STWS and on the other hand STBS and NT showed very similar soil structures. The computed tomographic parameters therefore provide valuable information about the impact of tillage on microscopic pore space attributes that improve our understanding about soil functional behavior at much larger scales.

  14. 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

  15. A feasibility study on gamma-ray tomography by Monte Carlo simulation for development of portable tomographic system

    International Nuclear Information System (INIS)

    Kim, Jongbum; Jung, Sunghee; Moon, Jinho; Cho, Gyuseong

    2012-01-01

    The electron beam X-ray tomographic scanner has been used in industrial and medical field since it was developed two decades ago. However, X-ray electron beam tomography has remained as indoor equipment because of its bulky hardware of X-ray generation devices. By replacing X-ray devices of electron beam CT with a gamma-ray source, a tomographic system can be a portable device. This paper introduces analysis and simulation results on industrial gamma-ray tomographic system with scanning geometry similar to electron beam CT. The gamma-ray tomographic system is introduced through the geometrical layout and analysis on non-uniformly distributed problem. The proposed system adopts clamp-on type device to actualize portable industrial system. MCNPx is used to generate virtual experimental data. Pulse height spectra from F8 tally of MCNPx are obtained for single channel counting data of photo-peak and gross counting. Photo-peak and gross counting data are reconstructed for the cross-sectional image of simulation phantoms by ART, Total Variation algorithm and ML-EM. Image reconstruction results from Monte Carlo simulation show that the proposed tomographic system can provide the image solution for industrial objects. Those results provide the preliminary data for the tomographic scanner, which will be developed in future work. - Highlights: ► We carried out feasibility study on gamma-ray tomography with electron beam CT scanning geometry. ► Gamma ray tomographic system is introduced through geometrical layout and analysis on non-uniformly distributed problem. ► We carried out MCNPx simulation for proposed geometry. ► Results show that this system can be used for transportable tomographic system.

  16. Single-Shot, Volumetrically Illuminated, Three-Dimensional, Tomographic Laser-Induced-Fluorescence Imaging in a Gaseous Free Jet

    Science.gov (United States)

    2016-04-28

    Single- shot , volumetrically illuminated, three- dimensional, tomographic laser-induced- fluorescence imaging in a gaseous free jet Benjamin R. Halls...37081 Göttingen, Germany 4School of Mechanical Engineering, Purdue University, West Lafayette, IN 47907, USA 5trmeyer@purdue.edu 6james.gord...us.af.mil Abstract: Single- shot , tomographic imaging of the three-dimensional concentration field is demonstrated in a turbulent gaseous free jet in co-flow

  17. Persistent and automatic intraoperative 3D digitization of surfaces under dynamic magnifications of an operating microscope.

    Science.gov (United States)

    Kumar, Ankur N; Miga, Michael I; Pheiffer, Thomas S; Chambless, Lola B; Thompson, Reid C; Dawant, Benoit M

    2015-01-01

    One of the major challenges impeding advancement in image-guided surgical (IGS) systems is the soft-tissue deformation during surgical procedures. These deformations reduce the utility of the patient's preoperative images and may produce inaccuracies in the application of preoperative surgical plans. Solutions to compensate for the tissue deformations include the acquisition of intraoperative tomographic images of the whole organ for direct displacement measurement and techniques that combines intraoperative organ surface measurements with computational biomechanical models to predict subsurface displacements. The later solution has the advantage of being less expensive and amenable to surgical workflow. Several modalities such as textured laser scanners, conoscopic holography, and stereo-pair cameras have been proposed for the intraoperative 3D estimation of organ surfaces to drive patient-specific biomechanical models for the intraoperative update of preoperative images. Though each modality has its respective advantages and disadvantages, stereo-pair camera approaches used within a standard operating microscope is the focus of this article. A new method that permits the automatic and near real-time estimation of 3D surfaces (at 1 Hz) under varying magnifications of the operating microscope is proposed. This method has been evaluated on a CAD phantom object and on full-length neurosurgery video sequences (∼1 h) acquired intraoperatively by the proposed stereovision system. To the best of our knowledge, this type of validation study on full-length brain tumor surgery videos has not been done before. The method for estimating the unknown magnification factor of the operating microscope achieves accuracy within 0.02 of the theoretical value on a CAD phantom and within 0.06 on 4 clinical videos of the entire brain tumor surgery. When compared to a laser range scanner, the proposed method for reconstructing 3D surfaces intraoperatively achieves root mean square

  18. A MEANS FOR CALIBRATING A MICROSCOPE, A METHOD OF PREPARING THE MEANS AND A METHOD OF CALIBRATING A MICROSCOPE

    DEFF Research Database (Denmark)

    2005-01-01

    A means or artefact for calibrating the height/depth or Z axis of a microscope, such as a confocal microscope, an interference microscope or a Scanning Electron Microscope. The artefact comprises a number of tapering or pie-shaped, parallel surfaces each extending from a central axis, whereby all...... surfaces and heights are visible independently of the magnification of the microscope. Thus, the full height range may be calibrated and the linearity thereof checked independently of the magnification....

  19. Tomographic Observation and Bedmapping of Glaciers in Western Greenland with IceBridge Sounding Radar

    Science.gov (United States)

    Wu, Xiaoqing; Paden, John; Jezek, Ken; Rignot, Eric; Gim, Young

    2013-01-01

    We produced the high resolution bedmaps of several glaciers in western Greenland from IceBridge Mission sounding radar data using tomographic sounding technique. The bedmaps cover 3 regions: Russell glaciers, Umanaq glaciers and Jakobshavn glaciers of western Greenland. The covered areas is about 20x40 km(sup 2) for Russell glaciers and 300x100 sq km, and 100x80 sq km for Jakobshavn glaciers. The ground resolution is 50 meters and the average ice thickness accuracy is 10 to 20 meters. There are some void areas within the swath of the tracks in the bedmaps where the ice thickness is not known. Tomographic observations of these void areas indicate that the surface and shallow sub-surface pockets, likely filled with water, are highly reflective and greatly weaken the radar signal and reduce the energy reaching and reflected from the ice sheet bottom.

  20. Tomographic Image Reconstruction Using Training Images with Matrix and Tensor Formulations

    DEFF Research Database (Denmark)

    Soltani, Sara

    machine learning technique (here, the dictionary learning), prototype elements from the training images are extracted and then incorporated in the tomographic reconstruction problem both with matrix and tensor representations of the training images. First, an algorithm for the tomographic image...... and robustness of the reconstruction to variations of the scale and rotation in the training images is investigated and algorithms to estimate the correct relative scale and orientation of the unknown image to the training images are suggested. Then, a third-order tensor representation for the training images...... images is used. The dictionary and image reconstruction problem are reformulated using the tensor representation. The dictionary learning problem is presented as a nonnegative tensor factorization problem with sparsity constraints and the reconstruction problem is formulated in a convex optimization...

  1. Tomographic capabilities of the new GEM based SXR diagnostic of WEST

    Science.gov (United States)

    Jardin, A.; Mazon, D.; O'Mullane, M.; Mlynar, J.; Loffelmann, V.; Imrisek, M.; Chernyshova, M.; Czarski, T.; Kasprowicz, G.; Wojenski, A.; Bourdelle, C.; Malard, P.

    2016-07-01

    The tokamak WEST (Tungsten Environment in Steady-State Tokamak) will start operating by the end of 2016 as a test bed for the ITER divertor components in long pulse operation. In this context, radiative cooling of heavy impurities like tungsten (W) in the Soft X-ray (SXR) range [0.1 keV; 20 keV] is a critical issue for the plasma core performances. Thus reliable tools are required to monitor the local impurity density and avoid W accumulation. The WEST SXR diagnostic will be equipped with two new GEM (Gas Electron Multiplier) based poloidal cameras allowing to perform 2D tomographic reconstructions in tunable energy bands. In this paper tomographic capabilities of the Minimum Fisher Information (MFI) algorithm developed for Tore Supra and upgraded for WEST are investigated, in particular through a set of emissivity phantoms and the standard WEST scenario including reconstruction errors, influence of noise as well as computational time.

  2. Suprathermal electron studies in the TCV tokamak: Design of a tomographic hard-x-ray spectrometer

    International Nuclear Information System (INIS)

    Gnesin, S.; Coda, S.; Decker, J.; Peysson, Y.

    2008-01-01

    Electron cyclotron resonance heating and electron cyclotron current drive, disruptive events, and sawtooth activity are all known to produce suprathermal electrons in fusion devices, motivating increasingly detailed studies of the generation and dynamics of this suprathermal population. Measurements have been performed in the past years in the tokamak a configuration variable (TCV) tokamak using a single pinhole hard-x-ray (HXR) camera and electron-cyclotron-emission radiometers, leading, in particular, to the identification of the crucial role of spatial transport in the physics of ECCD. The observation of a poloidal asymmetry in the emitted suprathermal bremsstrahlung radiation motivates the design of a proposed new tomographic HXR spectrometer reported in this paper. The design, which is based on a compact modified Soller collimator concept, is being aided by simulations of tomographic reconstruction. Quantitative criteria have been developed to optimize the design for the greatly variable shapes and positions of TCV plasmas.

  3. A feasibility study on gamma-ray tomography by Monte Carlo simulation for development of portable tomographic system.

    Science.gov (United States)

    Kim, Jongbum; Jung, Sunghee; Moon, Jinho; Cho, Gyuseong

    2012-02-01

    The electron beam X-ray tomographic scanner has been used in industrial and medical field since it was developed two decades ago. However, X-ray electron beam tomography has remained as indoor equipment because of its bulky hardware of X-ray generation devices. By replacing X-ray devices of electron beam CT with a gamma-ray source, a tomographic system can be a portable device. This paper introduces analysis and simulation results on industrial gamma-ray tomographic system with scanning geometry similar to electron beam CT. The gamma-ray tomographic system is introduced through the geometrical layout and analysis on non-uniformly distributed problem. The proposed system adopts clamp-on type device to actualize portable industrial system. MCNPx is used to generate virtual experimental data. Pulse height spectra from F8 tally of MCNPx are obtained for single channel counting data of photo-peak and gross counting. Photo-peak and gross counting data are reconstructed for the cross-sectional image of simulation phantoms by ART, Total Variation algorithm and ML-EM. Image reconstruction results from Monte Carlo simulation show that the proposed tomographic system can provide the image solution for industrial objects. Those results provide the preliminary data for the tomographic scanner, which will be developed in future work. Copyright © 2011 Elsevier Ltd. All rights reserved.

  4. Computer tomographic findings in splenic ruptures, subcapsular haematomas of the spleen and perisplenic abscesses

    International Nuclear Information System (INIS)

    Boettger, E.; Semerak, M.; Jaschke, W.; Rehabilitations-Krankenhaus Langensteinbach

    1980-01-01

    The computer tomographic criteria of splenic rupture, new or old haematomas of the spleen (pseudocysts) and perisplenic or subphrenic abscesses are described with reference to three cases. It is shown that all the relevant problems in the pre-operative stage can be clarified by computer tomography, making arteriography unnecessary. The differential diagnosis between old haematomas and perisplenic abscesses can only be made by taking account of the history and other clinical information. (orig.) [de

  5. The application of real-time, non-destructive electrical tomographic imaging to heritage conservation

    OpenAIRE

    Ogilvy, Richard

    2008-01-01

    Significant advances have been made in recent times with the non-invasive electrical tomographic imaging of the shallow subsurface. These emerging technologies are analogous to magnetic resonance imaging (MRI) or CT scans used in medical physics. Electrical Resistivity Tomography (ERT) is increasingly used to underpin studies in waste management, contaminated land characterisation and remediation, monitoring groundwater resources and the monitoring of geohazards or safety-critical plant. Ther...

  6. Three-dimensional display of computer tomographic examinations of craniofacial anomalies

    Energy Technology Data Exchange (ETDEWEB)

    Witte, G.; Hoeltje, W.; Tiede, U.; Riemer, M.

    1986-04-01

    Craniofacial anomalies are conventionally investigated by cephalometry using ordinary radiographs and by computed tomography. Both methods have the major disadvantage of trying to demonstrate a complex three-dimensional structure, such as the skull, in two dimensions and they therefore cannot display a true spatial image. We present the principle underlying a three-dimensional display derived from computer tomographic studies and discuss the clinical application in the diagnosis of craniofacial anomalies.

  7. A 3D tomographic EBSD analysis of a CVD diamond thin film

    Directory of Open Access Journals (Sweden)

    Tao Liu, Dierk Raabe and Stefan Zaefferer

    2008-01-01

    Full Text Available We have studied the nucleation and growth processes in a chemical vapor deposition (CVD diamond film using a tomographic electron backscattering diffraction method (3D EBSD. The approach is based on the combination of a focused ion beam (FIB unit for serial sectioning in conjunction with high-resolution EBSD. Individual diamond grains were investigated in 3-dimensions particularly with regard to the role of twinning.

  8. Computed tomographic evaluation of the altered pancreas in dog and cat

    International Nuclear Information System (INIS)

    Posch, B.

    2002-11-01

    Eighteen dogs and 12 cats of varying breed, age and sex underwent a computed tomographic study of the pancreas. Length, diameter and density of each lobe of the pancreas were measured. Further, the gained results were compared to the information established by the clinical examination, sonography, haematology and histology. Contrast CT improved evaluation of the pancreas in all cases of normal life controls. CT criteria such as changes in size, density, delimitation of the pancreas and the peripancreatic structures were analyzed. Increased pancreatic size was seen in inflammatory as well as in neoplastic diseases. There were no reliable computed tomographic criteria to differentiate pancreatic neoplasia from inflammation without peripancreatic findings. Ultrasonography proved to be a good screening method in this study: sonographic and computed tomographic results correlated in all cases with the exception of 5 cases. In contrast to ultrasonography CT could differentiate normal pancreas from pancreas atrophy. Computed tomography was superior to sonography in determining the full extent of pancreatic and peripancreatic signs due to the good overview and overall image of the abdominal structures. Serum chemistry of a- amylase and lipase were obtained in 28 animals. Assays of serum lipase and a- amylase activities were only able to detect acute pancreatitis in half of the canine cases. Despite morphological alterations detected with the help of sonography or CT, there were no significant increases in a- amylase and lipase in cats. Following computed tomography the pancreas of 10 animals was examined pathohistologically. With the exception of 2 cases the computed tomographic results correlated with the pathohistological findings. In conclusion, computed tomography (CT) proved to be a valuable method to evaluate the localization, the full extent and the seriousness of pancreatic lesions. (author)

  9. Numerical approach for a relaxed minimization problem arising in tomographic reconstruction

    Directory of Open Access Journals (Sweden)

    Ali Srour

    2013-05-01

    Full Text Available The purpose of this article is to develop a numerical scheme for a system of optimality conditions for a smooth minimization problem that arises in tomographic reconstruction of binary axially symmetric objects. The density function of the object with the Lagrange multipliers is seen as a saddle point of an associated Lagrangian, then we use the Usawa scheme mixed with descent gradient method to give the corresponding numerical scheme.

  10. Unfolding and smoothing applied to the quality enhancement of neutron tomographic images

    International Nuclear Information System (INIS)

    Almeida, Gevaldo L. de; Silvani, Maria I.; Lopes, Ricardo T.

    2008-01-01

    Resolution and contrast are the major parameters defining the quality of a computer-aided tomographic image. These parameters depend upon several features of the image acquisition system, such as detector resolution, geometrical arrangement of the source-object-detector, beam divergence, source strength, detector efficiency and counting time. Roughly, the detector finite resolution is the main source of systematic errors affecting the separation power of the image acquisition system, while the electronic noise and statistical fluctuation are responsible for the data dispersion, which spoils the contrast. An algorithm has been developed in this work aiming at the improvement of the image quality through the minimization of both types of errors. The systematic ones are reduced by a mathematical unfolding of the position spectra - used as projections to reconstruct the 2D-images - using the Line Spread Function - LSF of the neutron tomographic system. The principle behind this technique is that every single channel contains information about all channels of the spectrum, but it is concealed due to the automatic integration carried out by the detector. Therefore, knowing the shape of this curve, it is possible to retrieve the original spectra. These spectra are unfortunately corrupted by the unavoidable statistical fluctuation, and by oscillations arising from the unfolding process, which strongly affects the quality of the final unfolded image. In order to reduce this impact, the spectra have been filtered by a Fourier transform technique or smoothed with a least square fitting procedure. The algorithm has been applied to spectra of some test-bodies generated by an earlier developed tomographic simulator, which reproduces the spectra furnished by a thermal neutron tomographic system employing a position sensitive detector. The obtained results have shown that the unfolded spectra produce final images capable to resolve features otherwise not achievable with the

  11. [Computed tomographic features of abdominal compartment syndrome complicated by severe acute pancreatitis].

    Science.gov (United States)

    Wu, Jingtao; Zhu, Qingqiang; Zhu, Wenrong; Chen, Wenxin; Wang, Shouan

    2014-11-25

    To explore the computed tomographic (CT) imaging features of abdominal compartment syndrome (ACS) complicated by severe acute pancreatitis (SAP) to improve the diagnosis of disease. Thirty-six cases of ACS and 61 cases of non-ACS (NACS) complicated by SAP were studied retrospectively. And the meaningful CT features were studied. Among them, the ACS vascular complications of abdominal cavity and gastrointestinal bleeding were found significantly more in ACS than in NACS (P treatment.

  12. Tomographical evaluation of multifrequency-holography data in the ultrasonic testing of cylindrical components

    International Nuclear Information System (INIS)

    Kutzner, K.

    1986-01-01

    The data of multifrequency-holography on circle which were published in a previous paper were evaluated in a tomographical manner. For that the theoretical model which is the foundation of this measuring technique is converted into a Radon transform which can be inverted by standard methods. The results of this technique are compared with the results of the multifrequency-holography on circle. (orig./HP) [de

  13. Process and installation for producing tomographic images of the distribution of a radiotracer

    International Nuclear Information System (INIS)

    Fonroget, Jacques; Brunol, Jean.

    1977-01-01

    The invention particularly concerns a process for obtaining tomographic images of an object formed by a radiotracer distributed spacially over three dimensions. This process, using a detection device with an appreciably plane detection surface and at least one collimation orifice provided in a partition between the detection surface and the object, enables tomographic sections to be obtained with an excellent three-dimensional resolution of the images achieved. It is employed to advantage in an installation that includes a detection device or gamma camera on an appreciably plane surface, a device having a series of collimation apertures which may be used in succession, these holes being appreciably distributed over a common plane parallel to the detection surface, and a holder for the object. This holder can be moved in appreciably parallel translation to the common plane. The aim of this invention is, inter alia, to meet two requirements: localization in space and obtaining good contrasts. This aim is achieved by the fact that at least one tomographic image is obtained from a series of intermediate images of the object [fr

  14. Tomographic evaluation of a dual-head positron emission tomography system

    International Nuclear Information System (INIS)

    Efthimiou, N; Maistros, S; Tripolitis, X; Panayiotakis, G; Samartzis, A; Loudos, G

    2011-01-01

    In this paper we present the performance evaluation results, in the planar and tomographic modes, of a low-cost positron emission tomography camera dedicated to small-animal imaging. The system consists of two pixelated Lu 2 SiO 5 crystals, two Hamamatsu H8500 position sensitive photomultiplier tubes, fast amplification electronics and an FPGA-USB-based read-out system. The parameters that have been studied are (i) saturation as a function of the head distance and photon acceptance angle, (ii) effect of the number of projections and half or complete head's rotation, (iii) spatial resolution as a function of the head distance, (iv) spatial resolution as a function of acceptance angle, (v) system's sensitivity as a function of these parameters and (vi) performance in small mice imaging. Image reconstruction has been carried out using open source software developed by our group (QSPECT), which is designed mainly for SPECT imaging. The results indicate that the system has a linear response for activities up to at least 2 MBq, which are typical in small-animal imaging. Best tomographic spatial resolution was measured to be ∼2 mm. The system has been found suitable for imaging of small mice both in the planar and tomographic modes

  15. Simulation of Tomographic Reconstruction of Magnetosphere Plasma Distribution By Multi-spacecraft Systems.

    Science.gov (United States)

    Kunitsyn, V.; Nesterov, I.; Andreeva, E.; Zelenyi, L.; Veselov, M.; Galperin, Y.; Buchner, J.

    A satellite radiotomography method for electron density distributions was recently proposed for closely-space multi-spacecraft group of high-altitude satellites to study the physics of reconnection process. The original idea of the ROY project is to use a constellation of spacecrafts (one main and several sub-satellites) in order to carry out closely-spaced multipoint measurements and 2D tomographic reconstruction of elec- tron density in the space between the main satellite and the subsatellites. The distances between the satellites were chosen to vary from dozens to few hundreds of kilometers. The easiest data interpretation is achieved when the subsatellites are placed along the plasma streamline. Then, whenever a plasma density irregularity moves between the main satellite and the subsatellites it will be scanned in different directions and we can get 2D distribution of plasma using these projections. However in general sub- satellites are not placed exactly along the plasma streamline. The method of plasma velocity determination relative to multi-spacecraft systems is considered. Possibilities of 3D tomographic imaging using multi-spacecraft systems are analyzed. The model- ing has shown that efficient scheme for 3D tomographic imaging would be to place spacecrafts in different planes so that the angle between the planes would make not more then ten degrees. Work is supported by INTAS PROJECT 2000-465.

  16. TomoBank: a tomographic data repository for computational x-ray science

    Science.gov (United States)

    De Carlo, Francesco; Gürsoy, Doğa; Ching, Daniel J.; Joost Batenburg, K.; Ludwig, Wolfgang; Mancini, Lucia; Marone, Federica; Mokso, Rajmund; Pelt, Daniël M.; Sijbers, Jan; Rivers, Mark

    2018-03-01

    There is a widening gap between the fast advancement of computational methods for tomographic reconstruction and their successful implementation in production software at various synchrotron facilities. This is due in part to the lack of readily available instrument datasets and phantoms representative of real materials for validation and comparison of new numerical methods. Recent advancements in detector technology have made sub-second and multi-energy tomographic data collection possible (Gibbs et al 2015 Sci. Rep. 5 11824), but have also increased the demand to develop new reconstruction methods able to handle in situ (Pelt and Batenburg 2013 IEEE Trans. Image Process. 22 5238-51) and dynamic systems (Mohan et al 2015 IEEE Trans. Comput. Imaging 1 96-111) that can be quickly incorporated in beamline production software (Gürsoy et al 2014 J. Synchrotron Radiat. 21 1188-93). The x-ray tomography data bank, tomoBank, provides a repository of experimental and simulated datasets with the aim to foster collaboration among computational scientists, beamline scientists, and experimentalists and to accelerate the development and implementation of tomographic reconstruction methods for synchrotron facility production software by providing easy access to challenging datasets and their descriptors.

  17. Tomographic reconstruction of 3D thermal plasma systems: a feasibility study

    Science.gov (United States)

    Franceries, X.; Freton, P.; Gonzalez, J.-J.; Lago, F.; Masquère, M.

    2005-11-01

    A preliminary investigation of tomographic reconstruction of arc plasma in three dimensions has been carried out. The main goal of this work was to define both the optimal experimental scheme for tomographic measurements and the most appropriate tomographic method with minimum constraints to obtain images of good quality in real situations. Numerical calculations were developed and performed to define a test case corresponding to an experimental device. The multiplicative algebraic reconstruction technique (MART) was applied for reconstruction of the emission profile from the acquired projections. Numerical reconstruction from two, three, four and seven projections are presented and discussed in a theoretical three-dimensional (3D) transferred arc configuration. The dependence of the reconstructed image quality on both the projection directions and the noise level was studied. Numerical simulation demonstrated that MART was perfectly suitable for reconstructing satisfactory 3D emission and temperature profiles of the arc plasma with a four-view configuration, proving the feasibility and the utility of tomography to characterize a 3D plasma medium.

  18. Tomographic reconstruction of 3D thermal plasma systems: a feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Franceries, X; Freton, P; Gonzalez, J-J; Lago, F; Masquere, M [CPAT, CNRS UMR 5002, Paul Sabatier University, 118 rte de Narbonne, Bat3R2, 31062 Toulouse Cedex (France)

    2005-11-07

    A preliminary investigation of tomographic reconstruction of arc plasma in three dimensions has been carried out. The main goal of this work was to define both the optimal experimental scheme for tomographic measurements and the most appropriate tomographic method with minimum constraints to obtain images of good quality in real situations. Numerical calculations were developed and performed to define a test case corresponding to an experimental device. The multiplicative algebraic reconstruction technique (MART) was applied for reconstruction of the emission profile from the acquired projections. Numerical reconstruction from two, three, four and seven projections are presented and discussed in a theoretical three-dimensional (3D) transferred arc configuration. The dependence of the reconstructed image quality on both the projection directions and the noise level was studied. Numerical simulation demonstrated that MART was perfectly suitable for reconstructing satisfactory 3D emission and temperature profiles of the arc plasma with a four-view configuration, proving the feasibility and the utility of tomography to characterize a 3D plasma medium.

  19. Tomographic reconstruction of 3D thermal plasma systems: a feasibility study

    International Nuclear Information System (INIS)

    Franceries, X; Freton, P; Gonzalez, J-J; Lago, F; Masquere, M

    2005-01-01

    A preliminary investigation of tomographic reconstruction of arc plasma in three dimensions has been carried out. The main goal of this work was to define both the optimal experimental scheme for tomographic measurements and the most appropriate tomographic method with minimum constraints to obtain images of good quality in real situations. Numerical calculations were developed and performed to define a test case corresponding to an experimental device. The multiplicative algebraic reconstruction technique (MART) was applied for reconstruction of the emission profile from the acquired projections. Numerical reconstruction from two, three, four and seven projections are presented and discussed in a theoretical three-dimensional (3D) transferred arc configuration. The dependence of the reconstructed image quality on both the projection directions and the noise level was studied. Numerical simulation demonstrated that MART was perfectly suitable for reconstructing satisfactory 3D emission and temperature profiles of the arc plasma with a four-view configuration, proving the feasibility and the utility of tomography to characterize a 3D plasma medium

  20. Relation of the measuring values in cephalometric radiographs and TMJ tomographs

    Energy Technology Data Exchange (ETDEWEB)

    Han, Jin Woo [Kangnung National Univ. College of Dentistry, Kangnung (Korea, Republic of)

    2007-03-15

    To examine whether the maxillofacial skeletal morphology correlates with the condylar position and the anatomic characteristics of articular eminence using measurements of lateral cephalometric radiographs and individualized sagittal temporomandibular joint (TMJ) tomographs. I compared measurements of 202 TMJs of 101 orthodontic patients of Kangnung National University Dental Hospital. I used Pearson's correlation for comparison of the measuring values in lateral cephalometric radiographs and individualized sagittal TMJ tomographs. Large occlusal plane angle tendency showed decreased width of posterior eminence slope, decreased depth of articular fossa and decreased posterior slope angle of eminence. Large mandibular plane angle tendency showed decreased superior joint space, decreased superior joint space, decreased depth of articular fossa and decreased posterior slope angle of eminence. Large genial angle tendency showed decreased depth of articular fossa, decreased posterior slope angle of eminence and anterior position of comdylar head. Large anterior facial height and large posterior facial height tendency showed increased width of posterior position of condylar head. Maxillofacial skeletal morphology has correlation with the anatomic characteristics of TMJ. Individualized sagittal TMJ tomographs can provide useful information for anatomical analysis of TMJ.